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<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the receptor - receptor interaction field began with the studies on neuropeptide - monoamine receptor - receptor interactions in brain membrane preparations which altered especially the affinity of the monoamine receptor subtypes [ 1 , 2 ] .
the aim of the study was to understand the integration of peptide and monoamine signals present in many neuronal networks of the central nervous system ( cns ) .
it was proposed that they took place in postulated heteroreceptor complexes in the plasma membrane . in these complexes , adaptor proteins can participate and higher - order homo- and heteroreceptor complexes can also exist in which allosteric receptor - receptor interactions operate [ 48 ] .
we call them hetero- or homoreceptor complexes since a number of other proteins also participate like adaptor proteins which can directly bind to the receptor protomers undergoing homomerization or heteromerization [ 813 ] .
these integrative mechanisms give sophisticated dynamics to the structure and function of the heteroreceptor complexes with regard to alterations of recognition , signaling , and trafficking of the receptor protomers .
due to allosteric receptor - receptor interactions , increased diversity and selectivity develop in receptor pharmacology and function [ 19 , 20 ] .
dynamics is also given to the heteroreceptor complex through its balance with the corresponding homoreceptor complexes and other types of heteroreceptor complexes which share one or more receptor protomers [ 8 , 10 , 11 ] .
it is of high interest to understand the role of the allosteric receptor - receptor interactions in heteroreceptor complexes in neurons , brain circuits , and at the global network level . in the current paper
, we will discuss how this novel biological principle can serve to modulate the plasticity and function of the neural - glial networks of the cns .
the major focus will be on how cocaine abuse in rats can alter the adenosine a2a receptor- ( a2ar- ) dopamine d2 receptor ( d2r ) heterocomplexes and their receptor - receptor interactions in the neural - glial networks of the basal ganglia [ 12 , 21 ] .
the g protein - coupled receptor ( gpcr ) heterocomplex concept includes not only gpcr - gpcr heterocomplexes but also the interactions between gpcr and other membrane receptors , for instance , the ion channel receptors or receptor tyrosine kinases ( rtk ) heterocomplexes [ 9 , 2229 ] .
gpcrs with high affinity for neurotransmitters are major receptors for volume transmission ( vt ) and ion channel receptors like nmda , ampa , and gaba receptors are major receptors for synaptic transmission . therefore , gpcr - ion channel receptor heterocomplexes are major integrators of vt and synaptic transmission in neural - glial networks [ 30 , 31 ] .
this integration , which takes place at both the prejunctional and postjunctional level , can up- or downregulate synaptic efficacy and thus synaptic strength within neural - glial networks .
the vt signals may originate , for example , from local glial cells , extrasynaptic release of transmitters from neural afferents , local collaterals , and soma - dendrites and from diffusion and flow of for example , neuropeptides , and proteins or of extracellular vesicles from cerebrospinal fluids and/or surrounding neural - glial networks also forming functional modules .
this major mechanism for the balance and integration of synaptic and volume transmission may then lead to changes in the preferred outputs from the neural - glial module which in turn will change the function in the brain circuit involved . instead , gpcr - rtk heterocomplexes are of relevance for the survival and repair of the neural - glial networks by integrating and balancing trophic signaling with the gpcr - mediated metabolic signaling and information handling .
relevant examples of direct gpcr - rtk receptor - receptor interactions are a2ar - fgfr1 [ 25 , 33 ] , 5-ht1a - fgfr1 [ 9 , 27 , 28 ] , m3r - fgfr1 , tgr5-egfr , and adrb2-inr heteroreceptor complexes .
demonstrated transactivation mechanisms between adenosine a2a receptor and trkb receptor , which can involve allosteric mechanisms via direct gpcr - rtk interactions .
the changes in the protomer signaling panorama within the heteroreceptor complex may be highly dynamic processes related to the transient nature of the receptor complexes formed and can represent learning if by repetition it leads to short - term memory ( see below ) [ 13 , 31 ] .
changes in synaptic efficacies via alterations in synaptic strength are regarded as fundamental to learning .
the theory was recently advanced that such changes in synaptic plasticity can be brought about by anatomical reorganization of multiple postsynaptic homo- and heteroreceptor complexes and by resetting the multiple allosteric receptor - receptor interactions according to the patterns and amounts of synaptic signals released from the synaptic terminals decoded from the arriving patterns of action potentials [ 13 , 31 ] .
such a molecular reorganization of the receptor - protein architecture of the entire postsynaptic membrane is proposed to be the molecular basis of learning and short - term memory .
it may be described as a change of the barcode in the individual synapse , which leads to the formation of a new molecular engram . according to the theory , a reorganization of presynaptic homo- and heteroreceptor complexes also developed in the learning and memory process in order to ensure the maintenance of the pattern and amounts of multiple transmitters and modulators released which must be sensed by the postsynaptic membrane ( figure 1 ) .
the signaling dynamics of 5-ht1a - fgfr1 and d2-nts1 heteroreceptor complexes were also reported [ 26 , 41 ] .
oligomer size of diffusing gpcrs in the plasma membrane can be determined by fluorescence correlation spectroscopy with photon counting histogram analysis and the 5-ht2c receptor diffused as a dimer .
single fluorescent - molecule imaging demonstrates dynamic gpcr dimerization using a chemoattractant gpcr , the n - fomyl peptide receptor ( fpr ) .
thus , fpr dimers are quickly formed from fpr monomers and fpr monomers are rapidly formed from rapid dissociation of the fpr dimers .
experimental studies support the view that the dynamic properties of gpcrs depend on their coupling to the membrane environment , where the lipid composition plays a role in ligand - induced properties .
the dynamics are also indicated from studies using spatial intensity distribution analysis and rt - bret to understand the oligomeric organization of gpcrs .
the analysis demonstrated multiple forms from monomers to higher - order oligomers of the gpcr studied .
these studies support our view that the dynamic panorama of homo- and heteroreceptor complexes and their stabilization can form the basis of learning and memory at the molecular level and represent the molecular engram , when consolidated ( figure 1 ) .
our hypothesis on the molecular basis of learning and memory is summarized as follows : learning requires a new temporal qualitative and quantitative pattern of release of neurotransmitters .
the transient reorganization of the homo- and heteroreceptor complexes in the postsynaptic membrane contributes to pattern formation.this molecular reorganization of the postsynaptic membrane leads to a novel barcode , which represents a short - term memory ( transient molecular engram ) and defines the new pattern of transmitter release.this memory process is facilitated by the reorganization also of the presynaptic receptor complexes to help maintain the new transmitter release pattern to be learned by the postsynaptic membrane .
thus , the altered transmitter panorama can change the formation or disrupt the presynaptic receptor complexes through agonist dependent processes .
a retrograde feedback from the new postsynaptic transient molecular engram can also assist in this process .
it can involve the release and diffusion of soluble factors like purines and trophic factors and of extracellular vesicles like exosomes and microvesicles containing proteins including receptors and lipids.the consolidated reorganization of the postsynaptic receptor complexes and their extrasynaptic regions , including changes in scaffold proteins like disc1 and shank , can lead to long - term memory .
the long - term memory should result in a barcode and molecular engram similar to one found in short - term memory .
the mechanism for this process may involve the transformation of parts of the heteroreceptor complexes into unique transcription factors which can lead to the formation of novel adaptor proteins like gpcr interacting proteins and receptor activity - modifying proteins . some of these proteins can link the heteroreceptor complexes more strongly together .
others can link the heteroreceptor complexes more strongly to the cytoskeleton and to scaffold proteins and synaptic cell adhesion molecules.of special interest for the formation of truly long - term molecular engrams may be the release of transmitters from close - by terminals belonging to emotional brain circuits using , for example , dopamine ( da ) as a transmitter . when such terminal networks are activated due to motivation and reward linked to the learning and memory process , the transmitter , for example , da , can interact with the synapse , where the molecular engram is being formed , through short distance volume transmission .
it is postulated that the activation of , for example , synaptic and extrasynaptic da heteroreceptor complexes on the postsynaptic side has an ability via unique transcription factors to produce special adaptor proteins that can bind to the receptor - protein architecture of the molecular engram and consolidate them with an exceptional efficacy leading to life - long memories .
the transient reorganization of the homo- and heteroreceptor complexes in the postsynaptic membrane contributes to pattern formation .
this molecular reorganization of the postsynaptic membrane leads to a novel barcode , which represents a short - term memory ( transient molecular engram ) and defines the new pattern of transmitter release .
this memory process is facilitated by the reorganization also of the presynaptic receptor complexes to help maintain the new transmitter release pattern to be learned by the postsynaptic membrane .
thus , the altered transmitter panorama can change the formation or disrupt the presynaptic receptor complexes through agonist dependent processes .
a retrograde feedback from the new postsynaptic transient molecular engram can also assist in this process .
it can involve the release and diffusion of soluble factors like purines and trophic factors and of extracellular vesicles like exosomes and microvesicles containing proteins including receptors and lipids .
the consolidated reorganization of the postsynaptic receptor complexes and their extrasynaptic regions , including changes in scaffold proteins like disc1 and shank , can lead to long - term memory .
the long - term memory should result in a barcode and molecular engram similar to one found in short - term memory .
the mechanism for this process may involve the transformation of parts of the heteroreceptor complexes into unique transcription factors which can lead to the formation of novel adaptor proteins like gpcr interacting proteins and receptor activity - modifying proteins . some of these proteins can link the heteroreceptor complexes more strongly together .
others can link the heteroreceptor complexes more strongly to the cytoskeleton and to scaffold proteins and synaptic cell adhesion molecules .
of special interest for the formation of truly long - term molecular engrams may be the release of transmitters from close - by terminals belonging to emotional brain circuits using , for example , dopamine ( da ) as a transmitter .
when such terminal networks are activated due to motivation and reward linked to the learning and memory process , the transmitter , for example , da , can interact with the synapse , where the molecular engram is being formed , through short distance volume transmission .
it is postulated that the activation of , for example , synaptic and extrasynaptic da heteroreceptor complexes on the postsynaptic side has an ability via unique transcription factors to produce special adaptor proteins that can bind to the receptor - protein architecture of the molecular engram and consolidate them with an exceptional efficacy leading to life - long memories .
it was early on observed that the adenosine a2ar agonist cgs 21680 reduced the affinity of the dopamine d2r agonist binding sites , especially in the high affinity state , in dorsal striatum and nucleus accumbens [ 47 , 48 ] .
thus , antagonistic a2ar - d2r interactions appear to exist in the plasma membrane of neurons .
it was further demonstrated that the a2ars and d2rs coaggregate , cointernalize , and codesensitize in heteroreceptor complexes . in line with these findings ,
agonist activation of the a2ar protomer in the a2ar - d2r heteroreceptor complexes reduces d2r gi / o - mediated signaling through the allosteric receptor - receptor interaction [ 19 , 50 ] . instead , the a2ar agonist increases the d2r beta - arrestin2 mediated signaling and can be characterized as a biased inhibitory modulator of the gi / o - mediated d2r signaling .
the a2ar - d2r heterocomplexes interface involves mainly intracellular domains where electrostatic interactions form clasps in the interface ( hot spots ) [ 5355 ] and transmembrane domains where triplet amino acid homologies can play a special role as adhesive guides in the formation of the heteromer .
the overall architecture of the global gpcr heterodimer network ( http://www.gpcr-hetnet.com/ ) demonstrates that both a2ars and d2rs are hub components , each able to interact with ten or more different gpcrs .
thus , the a2ar - d2r heteroreceptor complex in a neuron can be in a complex balance not only with a2ar and d2r homoreceptor complexes but also with other types of a2ar and d2r heteroreceptor complexes , respectively [ 8 , 10 , 11 ] .
the a2ar - dr2 heteroreceptor complexes were demonstrated in the dorsal and ventral striatum by means of the proximity ligation assay ( in situ pla ) [ 34 , 59 ] . in relation to cocaine use disorder , it is of substantial interest that these complexes may participate in postjunctional mesolimbic da transmission in the nucleus accumbens core and shell in view of their presence in high densities in these two regions .
in situ pla - positive a2ar - d2r heteroreceptor complexes
are visualized in striatal sections as red clusters ( blobs , puncta ) within different regions of the neuropil of caudate putamen and nucleus accumbens core and shell , which can be quantitated as , for example , average number of blobs / cell .
a2ar - d2r heteroreceptor complexes exist mainly in the ventral striatopallidal gaba neurons that mediate antireward .
the circuit continues from the ventral pallidum into the medial thalamic nucleus - prefrontal cortex as well as into the ventral midbrain , there mainly appearing as collaterals from the other regions .
the stoichiometry of these complexes is unknown but can involve heterotrimers , heterotetramers , and etcetera .
also the critical balance with other types of a2ar or d2r heteroreceptor complexes is unknown .
one ventral striatopallidal gaba neuron may differ from another one with regard to the stoichiometry and composition of the a2ar - d2r heteroreceptor complexes as well as their distribution pattern among synapses .
does each neuron of this pathway possess a unique distribution of a2ar - d2r heteroreceptor complexes to certain of its synapses while others lack these complexes ?
can the switching in the balance between different d2r and a2ar heteroreceptor complexes in the same synapse be part of the learning process and contribute to short term and , if relevant , long - term memory and thus to the formation of a molecular engram ( see above ) ?
it is also of special interest that a loss of trkb , the receptor for bdnf , in d2r positive accumbens neurons leads to increased neuronal excitability and suppression of reward .
these results open up the possibility that trkb - d2r heteroreceptor complexes exist in which trkb directly or indirectly make the inhibitory gi / o - mediated d2r signaling possible , which leads to hyperpolarization and reduced excitability and firing .
thus , it appears possible that a2ar - d2r - trkb heteroreceptor complexes can also exist in this antireward system .
in fact , it was found that a2ars are necessary for the baseline bdnf levels and for enhancement of synaptic transmission by bdnf as determined in the hippocampus .
we have studied the effects of the a2ar agonist cgs 21680 on cocaine self - administration under different schedules of reinforcement .
active lever presses and cocaine infusions were attenuated by cgs 21680 and these effects could not be explained by sedation and reduction in locomotion although such inhibitory motor actions are linked to a2ar activation .
these results clearly indicated that activation of a2ars inhibits cocaine - induced reward in agreement with previous work [ 21 , 64 ] . of substantial interest
were the inhibitory effects of the cgs 21680 treatment in a progressive ratio schedule of reinforcement protocol with a 4-hour breaking point indicating that a2ar stimulation brings down not only cocaine reward but also cocaine motivation .
the effects of an accumbal perfusion of cgs 21680 were studied on changes induced by a 2 h cocaine self - administration session on extracellular accumbal da , gaba , and glutamate levels . in the cocaine self - administration session over 2 h ,
cgs 21680 induced an increase in extracellular gaba levels which appeared to reduce the increase in extracellular da levels found during cocaine self - administration .
this mechanism may restore the glutamate drive to the prefrontal cortex from the dorsomedial thalamic nucleus helping the prefrontal cortex to restore its control of the accumbens reward system .
these results are compatible with the involvement of antagonistic allosteric a2ar - d2r interactions in the ventral striatopallidal antireward system in mediating the a2ar induced inhibition of cocaine reward .
thus , restoring the allosteric antagonistic plasticity in the neuronal a2ar - d2r heteroreceptor complex may contribute to anticocaine actions of a2ar agonists .
such an increase in antagonistic allosteric plasticity in the a2ar - d2r heteroreceptor complex can also help explain why the a2ar agonist cgs 21680 produced a dose - dependent blockade of the cocaine , quinpirole , and cue - induced reinstatement of cocaine seeking [ 65 , 66 ] . in support of the view that the antagonistic a2ar - d2r interactions may control drug seeking
, it was found that cgs 21680 was 4 times more powerful in counteracting the d2-like receptor agonist quinpirole - induced relapse versus cocaine - induced relapse .
these inhibitory actions of cgs 21680 towards cocaine- or quinpirole - induced reinstatement of cocaine seeking behaviors in rats were in line with previous studies using i.p .
it is of relevance to point out that there exist also targets in the nucleus accumbens for a2ar agonists other than the a2ar - d2r heteroreceptor complexes like the a1-a2a heteroreceptor complexes preferentially located on the corticostriatal glutamate terminals [ 68 , 69 ] . here
, a2ar agonists can enhance glutamate release inter alia by an antagonistic allosteric receptor - receptor interaction with the a1r protomer which reduces its brake on glutamate release , which can modulate the activity of the d2r positive antireward and d1r positive reward neurons .
furthermore , there is evidence for the existence of postjunctional a2ar - mglu5r and a2ar - d2r - mglu5r heteroreceptor complexes in the striatopallidal gaba neurons [ 69 , 70 ] where the mglu5r protomer synergizes with the a2ar protomer to reduce d2r protomer signaling and its inhibition of the striatopallidal gaba neurons . by targeting also these heterocomplexes ,
it is also possible that these two types of a2ar - mglu5r heteroreceptor complexes exist in the glutamate nerve terminals where the a2ars and mglu5rs colocalize and functionally interact in synergistically enhancing glutamate release .
it appears that a2ar agonists by targeting several a2ar heteroreceptor complexes and a2ar homoreceptor complexes in the nucleus accumbens can increase activity in the antireward gaba neurons leading to anticocaine actions .
it was proposed that a2ar participates in a mechanism to integrate the gaba , da , and glutamate signaling . in this mechanism , also a2ar homoreceptor complexes participate and can inter alia be involved at the presynaptic level in increasing the synaptic striatopallidal gaba transmission in the globus pallidus . underlining the existence of an endogenous adenosine tone reducing d2r signaling , a2ar antagonists kw 6002 and sch 58261 induce reinstatement of cocaine seeking behavior in rats extinguished from cocaine self - administration .
the mechanism is proposed to involve a blockade of the a2ar protomer of the neuronal a2ar - d2r heteroreceptor complex in the ventral striatopallidal gaba pathway . by altering the allosteric interactions in this a2ar - d2r heteroreceptor complex ,
the brake on d2r signaling is reduced and cocaine seeking can develop due to reduction of the glutamate drive to the prefrontal cortex . in this way , it is possible that cognitive control including flexible goal - directed behavior probably becomes diminished and cocaine seeking develops .
d2rs are known to have a key role in cocaine use disorder [ 75 , 76 ] .
however , a2ars appear to have a different role in the dorsal striatum where a striatum - specific a2ar deletion led to selective impairment of habit formation .
later on , it was demonstrated that dorsomedial striatopallidal gaba neurons upon optogenetic activation of their a2ars diminished goal - directed behavior .
thus , in this circuit , a2ar signaling when linked to reward may favour habit formation .
it is clear , however , that a2ar agonists target both a2ar homo- and a2ar - d2r heteroreceptor complexes and that a2ar homoreceptor complexes can contribute to the anticocaine actions observed .
there are at the moment no preferential a2ar agonists for the a2ar protomer of the a2ar - d2r heteroreceptor complex nor preferential antagonists for the d2r protomer of this complex .
multitargeting drugs with a2ar agonist and d2r antagonist activities are promising molecules to combat cocaine use disorder .
heterobivalent drugs are attractive novel drugs to be developed [ 8083 ] . in this case , they should be built based on an a2ar agonist pharmacophore linked to a d2r antagonist pharmacophore which should preferentially target a2ar - d2r heteroreceptor complexes with a high affinity and selectivity .
their selective action on neurons containing a2ar - d2r heteroreceptor complexes may predict less side effects .
previously , a2ar antagonist - d2r agonist bivalent compounds were proposed as tools to find a2ar - d2r receptor heteromers and as a novel strategy for treatment of parkinson 's disease .
small inhibitory interface peptides targeting the a2ar - d2r interface are also of interest as they may block the formation of the a2ar - d2r heteroreceptor complex or alter the heteroreceptor - mediated signaling .
inhibitory interface peptides were first used in studies on d5r - gaba - a , d1r - nmdar , and d2r - nr2b heterocomplexes showing their physiological role .
competitive peptides were also used in determining the physiological role of a2ar - d2r heterodimerization in regulating nmdar mediated excitation of neurons in the nucleus accumbens .
furthermore , their use could help to unravel the role of the a2ar - d2r heteroreceptor complexes versus the a2ar homoreceptor complex in the actions of a2ar agonists on cocaine reward and cocaine seeking .
previous work demonstrated that antagonistic allosteric a2ar - d2r interactions exist in the ventral and dorsal striatum of drug nave control rats involving an a2ar induced reduction of the affinity of the high affinity d2r agonist binding site [ 47 , 48 ] .
it was therefore of high interest to study how maintenance of cocaine - self - administration affected this allosteric interaction in the ventral and dorsal striatum .
it was found that cocaine self - administration differentially affected the allosteric a2ar - d2r interactions in the ventral and dorsal striatum versus the yoked saline group .
the current protocol produces elevation of extracellular levels of da in the nucleus accumbens in 2 h cocaine self - administration sessions and no changes in the a2ar and d2r antagonist binding sites in the striatum were observed in terms of bmax and kd values .
it was found that cgs 21680 , the a2ar agonist , ex vivo using 3h - raclopride / quinpirole competition curves produced a significant reduction of the affinity of the d2-like high affinity receptor agonist binding site after cocaine self - administration in the ventral striatum versus the yoked saline group .
the mechanism may involve a cocaine - induced change in the balance of a2ar - d2r heteroreceptor complexes versus a2ar homoreceptor complexes and other types of a2ar heteroreceptor complexes favouring an increase in a2ar - d2r heteroreceptor complexes .
such a change can contribute to the increase in the antagonistic allosteric a2ar - d2r interaction observed .
our hypothesis is that changes in neuronal plasticity in cocaine self - administration may involve a reorganization of the balance of the a2ar monomers and homo / heteroreceptor complexes which can vary from one synapse to another and from one neuron to the other one .
several a2ar heteroreceptor complexes were already discussed and can be present at the pre- and/or postsynaptic level including the a2ar - d2r heteroreceptor complexes and together with other heteroreceptor complexes like the nmdar heteroreceptor complexes [ 22 , 24 ] . it should be noted that inactivation of a2ars blocks long - term potentiation and working memory deficits are reversed upon inactivation of a2ars .
another mechanism may be that cocaine through its release of da and/or indirect / direct allosteric enhancement of d2r signaling can induce an allosteric feedback to help reduce d2r function via this antagonistic allosteric mechanism in the ventral striatum .
thus , the anticocaine actions of a2ar agonists may at least in part be determined by the strength of the antagonistic allosteric a2ar - d2r interaction and the number of a2ar - d2r heteroreceptor complexes present , which leads to increased activity of the ventral striatopallidal gaba neurons representing an antireward system .
dynamic changes also developed in the allosteric a2ar - d2r interactions in the dorsal striatum upon maintenance of cocaine self - administration .
however , in this case , they resulted in disappearance of the antagonistic a2ar - d2r interaction found in yoked saline rats after ex vivo incubation of the membrane preparations with the a2ar agonist cgs 21680 .
as a consequence , no reduction of the affinity in the d2r high affinity agonist binding site was observed .
thus , the allosteric brake on the d2r protomer signaling in the a2ar - d2r heteroreceptor complex of the dorsal striatopallidal gaba neurons is lost upon cocaine self - administration .
this is potentially due to differences in composition and allosteric plasticity of these complexes versus those in the ventral striatopallidal neurons . in line with these results
, it was previously found that da increased its potency to increase d2r gi / o coupling in dorsal but not ventral striatal membranes in cocaine self - administration .
it is proposed that the disappearance of the allosteric brake on the d2r protomer signaling in the a2ar - d2r heteroreceptor complex can alter cocaine seeking , habit forming learning , and/or locomotor sensitization which remains to be determined . in view of the allosteric theory of learning and memory based on the formation of a molecular engram built up of homo- and heteroreceptor complexes
[ 12 , 13 ] , it is proposed that the loss of the allosteric a2ar - d2r interactions is caused by a reorganization or loss of the a2ar - d2r heteroreceptor complex .
this leads to an alteration of the molecular engram in the synapses affected linked to a change in learning due to loss of the allosteric brake .
the altered long - term memories formed are likely the basis for the novel habits formed versus goal - directed behavior .
neuronal plasticity induced by cocaine at the molecular level through allosteric mechanisms can therefore produce changes in the brain circuits involved . according to the work of li et al .
therefore , the increased balance of a2ar and d2r signaling in the dorsomedial striatopallidal gaba neurons through loss of the inhibitory allosteric mechanism should reduce , if anything , the appearance of abnormal habit formation .
the hypothesis is advanced that the mechanism for the potential therapeutic actions of a2ar agonists in cocaine addiction is their ability to activate the a2ar brake on d2r protomer signaling in the ventral striatum even more strongly in this disease than in drug nave controls .
this action will markedly reduce the rewarding actions of cocaine through the activation of the antireward system .
however , the a2ar protomer brake on the d2r protomer signaling in the dorsal striatum in contrast disappears upon prolonged cocaine use .
the mechanism for the differential effects observed on the allosteric a2ar - d2r interactions in the ventral versus the dorsal striatum in cocaine self - administration can depend on regional differences in the stoichiometry and composition of the a2ar - d2r heteroreceptor complexes [ 10 , 11 ] .
this could involve differential recruitment of adaptor proteins and other receptors to the heteroreceptor complex .
it is known that sigma-1r - d2r heteroreceptor complexes exist and form higher - order oligomers and are specific for d2rs versus d3rs and d4rs .
recently , it was shown with bret analysis that sigma-1rs form heteroreceptor complexes to the same degree with d2 short and long receptor isoforms [ 14 , 15 ] .
it is of substantial interest that the sigma-1r addition in increasing concentrations does not reduce the bret signal obtained with either d2 short or d2 long isoforms in cell models .
the explanation can be multiple interfaces for sigma-1r - d2r interactions ; that is , the sigma-1r may bind to different regions of the d2r . with in situ pla
, the sigma-1r - d2r heteroreceptor complexes were demonstrated within discrete regions of the dorsal and ventral striatum of the rat [ 14 , 15 ] .
the densities of complexes were substantially higher in the dorsal versus the ventral striatum [ 14 , 15 ] and a selective cocaine - induced increase of the sigma1rs was demonstrated in the ventral versus the dorsal striatum .
these results can help understand the differential effects on allosteric a2ar - d2r interactions observed upon cocaine self - administration in the ventral and dorsal striatum ( see above ) .
the mechanism may involve an increased presence of a2ar - d2r - sigma-1r heteroreceptor complexes in the ventral versus the dorsal striatum after cocaine self - administration ( figure 2 ) . in relation to this hypothesis
, there are novel data on the actions of cocaine at a low concentration on d2r signaling using creb luciferase reporter gene assay in hek293 cells .
cocaine ( 100 nm ) increased the potency of d2r signaling when d2rs and sigma-1rs were expressed together .
thus , cocaine at a low concentration can enhance the d2r mediated neurochemical effects like enhancement of gi / o - mediated coupling but only in the sigma-1r - d2r heteroreceptor complex .
these effects remained in the presence of da transporter inhibitors and likely represented allosteric effects on the d2r protomers mediated via the sigma-1r in the heteroreceptor complex . in the absence of cocaine , a coexpression of d2rs and sigma-1rs show a reduced potency of d2r agonists to inhibit the creb signal [ 14 , 15 ] .
it is of high interest that , even in the presence of 100 nm cocaine , cgs 21680 strongly reduced the potency of the d2r agonist to inhibit the creb signal .
this suggests the existence of a putative a2ar - d2r - sigma-1r heteroreceptor complex in hek293 cells where the antagonistic a2ar - d2r interactions may be strongly enhanced . in this context , it is relevant to notice the partial overlap in the distribution of d2r - sigma1r and a2ar - d2r heteroreceptor complexes in the nucleus accumbens shell as found with in situ pla . in line with these results ,
it was found in hek293 cells coexpressing sigma-1rs and d2rs that cocaine at 1 nm increased the bmax values of plasma membrane d2rs , an action blocked by the sigma-1r antagonist pd 144418 .
the mechanism for the increase in the bmax values can involve a blockade of cocaine - induced d2r - yfp internalization when the sigma-1r forms a heteroreceptor complex with the d2r .
this action was so far observed in the 1100 nm range of cocaine [ 14 , 15 ] .
these results on cocaine actions in the nanomolar range on d2r - sigma-1r and on putative a2ar - d2r - sigma-1r heteroreceptor complexes are of high interest .
they offer a new possibility to understand the differential effects of self - administered cocaine on the allosteric a2ar - d2r interactions in the dorsal versus the ventral striatum in the cocaine self - administration experiments ( figure 2 ) .
it is proposed that the higher density of d2r / sigma-1r heterocomplexes in the dorsal versus the ventral striatum [ 14 , 15 ] and selective cocaine - induced increases of the sigma-1rs in the ventral striatum contribute to the differential effects of self - administered cocaine on the a2ar - d2r interactions in the dorsal and ventral striatum , respectively ( figure 2 ) .
the sigma-1r is a molecular chaperone which inter alia assists in the translocation of receptors , especially d2rs , to the plasma membrane through its binding to the receptor .
it can also directly bind to the d2r in the plasma membrane [ 17 , 91 ] .
the current overview supports the hypothesis that the a2ar agonists represent novel drugs against cocaine use disorder because they inter alia can trigger the antagonistic allosteric a2ar - d2r interactions in a2ar - dr2 and a2ar - d2r - sigma-1r heteroreceptor complexes located in the ventral striatum .
however , also a2ar homoreceptor complexes can participate as well as other types of a2ar heteroreceptor complexes like a2ar - mglu5r and a2ar - mglu5r - d2r heteroreceptor complexes [ 73 , 92 ] . such actions would result in increased activity in the ventral striatopallidal gaba antireward pathway thus leading to reward reversal and reduction of cocaine reinforcement in self - administration .
the mechanism may in cocaine self - administration involve a differential reorganization of the a2ar - d2r , sigma-1r - d2r , and a2ar - d2r - sigma-1r heteroreceptor complexes and their balance with a2ar homoreceptor complexes and other types of a2ar heteroreceptor complexes in the ventral striatum as discussed above .
it can lead to the differential dopaminergic signaling observed in the ventral and dorsal striatum with selective a2ar agonist induced inhibition of d2r signaling in the ventral striatum ( figure 2 ) .
the loss of the antagonistic allosteric a2ar - d2r interactions in the dorsal striatopallidal gaba neurons of the dorsal striatum found in cocaine self - stimulation can have an impact on novel habit formation versus goal - directed behavior that remains to be determined . | ### Summary:
: our hypothesis is that allosteric receptor - receptor interactions in homo- and heteroreceptor complexes may form the molecular basis of learning and memory .
this principle is illustrated by showing how cocaine abuse can alter the adenosine a2ar - dopamine d2r heterocomplexes and their receptor - receptor interactions and hereby induce neural plasticity in the basal ganglia .
studies with a2ar ligands using cocaine self - administration procedures indicate that antagonistic allosteric a2ar - d2r heterocomplexes of the ventral striatopallidal gaba antireward pathway play a significant role in reducing cocaine induced reward , motivation , and cocaine seeking .
anticocaine actions of a2ar agonists can also be produced at a2ar homocomplexes in these antireward neurons , actions in which are independent of d2r signaling . at the a2ar - d2r heterocomplex , they are dependent on the strength of the antagonistic allosteric a2ar - d2r interaction and the number of a2ar - d2r and a2ar - d2r - sigma1r heterocomplexes present in the ventral striatopallidal gaba neurons .
it involves a differential cocaine - induced increase in sigma1rs in the ventral versus the dorsal striatum .
in contrast , the allosteric brake on the d2r protomer signaling in the a2ar - d2r heterocomplex of the dorsal striatopallidal gaba neurons is lost upon cocaine self - administration .
this is potentially due to differences in composition and allosteric plasticity of these complexes versus those in the ventral striatopallidal neurons . |
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: osseointegration , defined as a direct structural and functional connection between ordered , living bone and the surface of a load - carrying implant , is critical for implant stability and is considered a prerequisite for implant loading and long - term clinical success of endosseous dental implants [ 1 , 2 ] . since
implant surface properties have long been identified as an important factor to promote osseointegration [ 1 , 2 ] , research has focused on optimizing the potential for osseointegration , and surface modifications have been extensively investigated [ 39 ] . nowadays , dental implants are fabricated by machining titanium rods , followed by modification of the implant surface design , such as sandblasting , acid - etching [ 4 , 5 ] , anodization [ 6 , 7 ] , discrete calcium - phosphate crystal deposition , and chemical modification [ 3 , 6 , 9 ] .
in fact , several studies have demonstrated that implant surface topography plays a pivotal role in many peri - implant cellular and molecular mechanisms [ 310 ] .
rough surfaces have demonstrated better adsorption of biomolecules from biological fluids , which has the potential to alter the cascade of events that leads to bone healing and intimate apposition with the device [ 13 , 10 ] . in vitro reports
indicate that rough surfaces improve the initial cellular response , including cytoskeletal organization and cellular differentiation with matrix deposition [ 13 , 8 , 9 ] .
histologically , it has been demonstrated that rough surfaces can effectively promote better and faster osseointegration , when compared to machined surfaces [ 11 , 12 ] . from a clinical point of view , several studies have reported excellent long - term survival / success rates for rough surface implants [ 5 , 7 , 13 ]
. however , all the aforementioned methods used for processing dental implants result in a high - density titanium structure with a micro- or nanorough surface .
an alternative approach is to obtain implants with a functionally graded structure , possessing a gradient of porosity perpendicular to the long axis and relatively high porosity at the surface [ 14 , 15 ] . in the last years
, macroporous structures have become popular strategies to reach a tough and durable bone fixation . in accordance with the modern concepts of bone tissue engineering , an open interconnected porous structure with pores in the range of 200400 m
is required for bone regeneration ; in fact , extensive body fluid transport through the porous scaffold matrix is possible , which can trigger bone ingrowth , if substantial pore interconnectivity is established .
improved fixation can be achieved by bone tissue growing into and through a porous matrix of metal , bonding in this way the implant to the bone host ; however , from the mechanical point of view , this porous structure should be stiff enough to sustain mechanical loads [ 16 , 17 ] .
since osseointegration is such an important factor in the success of dental implants , it may be biologically beneficial to use porous implants , extending the features that promote osseointegration beyond the surface , throughout the body of the device .
a variety of methods have been developed in recent years to produce a porous coating on the implants , with the specific aim of creating a structure capable of enhancing osseointegration , such as plasma spraying , three - dimensional fiber deposition , powder metallurgy , solid - state foaming techniques , and polymeric sponge replication . with these conventional methods ,
however , it is impossible to fabricate a porous structure with a completely controlled design of the external shape as well as the internal pore network , with the tight constraints of porosity , optimum pore size , and mechanical strength that are required [ 25 , 26 ] .
as the development of open porous structures has been hampered by limitations in production techniques [ 1924 ] , there is a demand for fabrication methods for bulk porous titanium that can control porosity , pore size and distribution , and mechanical properties [ 14 , 15 , 25 , 26 ] .
additive manufacturing ( am ) methods have been proposed as a way to overcome this issue [ 14 , 15 , 2527 ] .
additive manufacturing ( am ) , also known as solid freeform fabrication ( sff ) , layered manufacturing ( lm ) , or direct digital manufacturing ( ddm ) , is a strategy to generate directly physical objects with defined structure and shape on the basis of virtual three - dimensional ( 3d ) model data [ 2527 ] . in particular , am comprises a group of techniques that can generate a physical model directly from computer - assisted - design ( cad ) data or data provided by computer - based medical imaging technologies in a layer - by - layer manner , where each layer is the shape of the cross section of the model at a specific level [ 2528 ] .
direct metal laser sintering ( dmls ) is a laser - based am technique , in which an object is built layer by layer using powdered metals , radiant heaters , and a computer - controlled laser [ 2529 ] .
basically , the machine produces the object on a moveable platform by applying incremental layers of the pattern material [ 2529 ] . for each layer
, the machine lays down a film of powders , with an accurate thickness ( 0.1 mm ) .
then , a high power laser beam is directed on a powder bed and programmed to fuse metal powders present in its focal zone , according to a computer - assisted - design ( cad ) file , thus generating a thin metal layer .
the platform moves down the preprogrammed layer thickness , a fresh film of powder is laid down , and the next layer is melted with exposure to the laser source , so that it conforms to the previous layer .
this process continues , layer by layer , until the object is fabricated [ 2529 ] .
with dmls it is possible to control the porosity of each layer but also pore interconnectivity , size , shape , and distribution , and consequently the 3d architecture of the implant , by changing the processing parameters , such as laser power and peak power ( for cw and pulsed lasers , resp . ) , laser spot diameter , layer thickness , hatching pitch ( or scan spacing ) , scan speed , and scanning strategy , or by modifying the size of the original titanium particles [ 2529 ] .
this is an important advantage of this technique : a high level of interconnectivity resulting in a predominantly open pored morphology may allow bone ingrowth and vascularization , thus enhancing osseointegration , the essential factor of the long - term reliability of an implant [ 2529 ] .
in addition , since the mechanical properties of biomaterials are dependent on their microarchitecture , dmls technology can be used to fabricate porous titanium implants with mechanical properties ( stiffness ) close to bone [ 2529 ] .
in fact , a porous implant will have a yield strength and elastic modulus that are reduced compared to a fully dense component . as a result
, the mechanical properties of a porous device can be tailored to better match the yield strength and elastic modulus of the host bone and therefore avoid undesired effects such as stress shielding which is associated with a mismatch in bone - implant elastic moduli [ 2529 ] .
another advantage of dmls is to have the unlimited freedom and ability to fabricate complex - shaped patient - specific , custom - made titanium implants , in a cost - time competitive manner [ 28 , 29 ] .
in fact , as dmls builds up parts directly from cad data , no further tooling costs or inventories are necessary .
finally , in contrast to cutting or milling processes , dmls technology produces less waste and thus there is almost no loss of material [ 28 , 29 ] .
even though by now the concept of am and dmls technologies for implant and biomaterial manufacturing are well accepted , there is still limited data available on dmls titanium implants in the current literature .
the aim of the present review was to evaluate the evidence for the reliability of dmls titanium dental implants and the clinical and histologic / histomorphometric outcomes , as well as their mechanical properties .
the protocol of this review is in accordance with prisma ( preferred reporting items for systematic reviews and meta - analyses ) , the cochrane collaboration , and checkreview checklists .
it was developed a priori and covered all aspects of review methodology : rationale , design , focused question , inclusion and exclusion criteria , search strategy , quality assessment , and data synthesis .
the focused questions read : what is the reliability of dmls titanium dental implants ? may the use of dmls implants provide benefits , in terms of clinical outcome and histologic / histomorphometric results , compared to the use of conventional implants ? .
the protocol recognized that randomized controlled trials ( rcts ) are the most appropriate designs to address a focused question that embraces effectiveness of interventions .
however , both experimental ( rcts ) and observational studies ( case reports , case series , and case - control and prospective cohort trials ) were included in the hierarchy of evidence for this review .
inclusion criteria were clinical and radiographic studies , histologic and histomorphometric studies in humans and animals , mechanical evaluations , and in vitro studies ( cell cultures ) on dmls titanium implants .
exclusion criteria were studies in which there was no reference to either the treating or supervising clinician or the site ( practice / hospital / university ) where the research was done .
electronic database searches of medline , embase , and scopus were performed using keywords and mesh terms based on a search strategy used for searching medline ( via pubmed ) : ( ( ( direct metal laser sintering implants or direct metal laser forming implants or selective laser sintering implants or selective laser melting implants ) ) or ( additive manufacturing implants or laser - sintered implants or direct laser fabrication implants or porous titanium implants or porous titanium scaffolds ) ) and ( dental implant or ( dental and implant ) or osseointegration ) .
the searches were confined to full - text articles written in all languages since and including january 2005 to january 2014 presenting either clinical / radiographic data , histologic / histomorphometric evaluations , mechanical evaluations , or in vitro ( cell cultures ) studies .
titles and abstracts were screened and then full texts of all potentially relevant publications were obtained and reviewed independently in duplicate by f. mangano and l. chambrone , who also undertook data extraction .
the purposely designed data extraction forms recorded study title , authors , type of study , randomization and blinding if present , number of subjects treated , study design and treatment phase , follow - up , outcomes , statistical findings , and conclusions . in addition , the reference lists of included studies were also hand - searched .
for rcts , the methodological quality of the studies was designed to assess the points described by the cochrane collaboration 's tool for assessing risk of bias and detailed in previous publications : ( 1 ) method of randomisation ; ( 2 ) allocation concealment ; ( 3 ) masking of examiners with regard to the treatment ; ( 4 ) completeness of the follow - up ; ( 5 ) selective reporting ; and ( 6 ) other sources of bias . for observational studies ,
the newcastle - ottawa scale ( nos ) adapted by chambrone and colleagues was used to evaluate the methodological quality of all studies included ( appendix ) .
concisely , the subsequent topics were evaluated : ( a ) selection of study groups ( i.e. , sample size calculation , representativeness of the patients and their selection , ascertainment / assessment of peri - implant conditions , clear description of methods used for dmls , training / calibration of assessors of outcomes , data collection , and description of clear inclusion / exclusion criteria ) ; ( b ) comparability ( i.e. , comparability of patients on the basis of the study design or analysis and management of potential confounders ) ; ( c ) outcome ( i.e. , evaluation of results , assessment of peri - implant outcomes and adequacy of follow - up of the patients ) ; and ( d ) statistical analysis ( i.e. , appropriateness / validity of statistical analysis and unit of analysis reported in the statistical model ) .
also , stars ( points ) were given to these methodological quality criteria , and each study included could receive a maximum of 14 points .
studies with 1114 stars ( approximately 80% or more of the domains satisfactorily fulfilled ) were arbitrarily considered as being of high quality , with 810 stars indicating medium quality and < 8 stars suggesting low methodological quality .
meta - analysis was considered only if it was possible to find randomized controlled studies ( rcts ) with an outcome measurement of histologic evaluation with histomorphometric analysis reported .
mean and standard deviation ( sd ) values of newly formed bone from each study would have been used , and weighted mean values would have been assessed to account for the difference in the number of subjects among the different studies . to compare the results between the test and the control groups , the differences of regenerated bone in mean and 95% confidence intervals ( cis ) would have been calculated , with the aid of a statistical package ( package metafor ; wolfgang viechtbauer , maastrich , the netherlands ) .
of the 423 potentially eligible publications initially identified by the search strategy , 396 were excluded following review of the title and/or abstract . in total , 27 studies were considered to be eligible for inclusion in the present literature review ( figure 1 ) .
these articles were published over a 10-year period , between 2005 and 2014 , and demonstrated considerable variation with respect to study type , study design , follow - up , and results .
no rcts on dmls implants were found in the current literature . among all the works included in the present review , 7 were clinical studies ( 4 cohort studies ; 1 case series ; 2 case reports ) reporting results of only test groups without any control groups
; 6 were histologic / histomorphometric studies on humans ( 3 cts ; 3 case series ) ; 6 were histologic / histomorphometric studies on animals ( 5 cts ; 1 case series ) ; 4 were mechanical studies ; and finally , 4 were cell culture studies . only a few clinical studies on dmls titanium implants
3 were prospective clinical studies on standard size dental implants ( tixos , leader implants , milan , italy ) [ 3537 ] , while 4 were clinical studies or reports on the application of dmls technology for the fabrication of custom - made implants [ 3841 ] .
all the implants used in these studies were fabricated with the same processing parameters / laser settings and were characterised by a porous surface with an average pore size of 200400 m , on a bulk , dense titanium core [ 3541 ] . in the first prospective multicenter clinical study using internal - hexagon dmls implants ,
a total of 201 implants ( 106 maxillae , 95 mandibles ) were inserted in 62 patients , with a two - stage technique ( the healing time was 2 - 3 months in the lower jaw and 3 - 4 months in the upper jaw ) .
the prosthetic restorations comprised 105 single crowns ( scs ) , 45 fixed partial prostheses ( fpps ) , and two fixed full - arch prostheses ( ffas ) . at the end of the study , after 1 year of functional loading , an overall implant survival rate of 99.5% was reported , with only one implant loss ( maxilla : 99.0% , 1 implant failure ; mandible : 100.0% , no implant failures ) . among the survived implants ( 200 ) , 5 did not fulfill the established clinical and radiographic success criteria , giving an implant - crown success of 97.5% .
finally , the mean distance between the implant shoulder and the first visible bone contact ( dib ) was 0.4 mm ( 0.2 ) .
this study supports the concept that internal - hexagon dmls implants can be used in fixed prosthetic rehabilitations of both jaws , with a predictable positive outcome . in another prospective study on the immediate loading of mandibular overdentures supported by unsplinted , one - piece ball attachment dmls implants , with 96 implants inserted in the edentulous mandible of 24 patients , a satisfactory 1-year implant survival rate of 98.9%
did not fulfill the established clinical and radiographic success criteria , for an overall implant success rate of 97.8% .
the mean dib was 0.2 mm ( 0.3 ; 95% confidence interval : 0.240.32 ) .
based on these results , the authors concluded that the immediate loading of unsplinted dmls implants by means of ball attachment - supported mandibular overdentures seems to represent a safe and successful procedure .
finally , in a 2-year prospective clinical study on the immediate restoration of fixed partial prostheses ( fpps ) supported by one - piece narrow - diameter ( 2.73.2 mm ) dmls implants , where 37 implants were installed in the posterior jaws ( 14 maxillae , 23 mandibles ) of 16 patients , no implant failure occurred , resulting in a 100% survival rate .
the implant success , based on clinical and radiographic criteria , was 94.6% , and the mean dib was 0.4 mm ( 0.3 ) .
this study supports the hypothesis that one - piece narrow - diameter dmls implants can be successfully used in fixed prosthetic rehabilitations in the posterior regions of both jaws . finally , with dmls
, patient - specific implants can be produced : in fact , this technique can be used for the fabrication of custom - made titanium implants , such as root - analogues [ 3841 ] or blade implants , adapting the implant to the anatomy of the patient instead of adapting the patient 's bone to a preformed standardized fixture .
two different case reports have demonstrated that modern cone beam computed tomography ( cbct ) acquisition and 3d image conversion , combined with the dmls process , allow the fabrication of custom - made , root - analogue implants [ 39 , 40 ] . in these reports ,
cbct images of residual nonrestorable roots of maxillary premolars ( biradicular first premolar and monoradicular second premolar , resp . ) were acquired and modified with specific software into 3d models . from these models , two custom - made , root - analogues dmls implants were fabricated , as perfect copies of the radicular units that needed replacement .
the nonrestorable residual roots were extracted , and immediately after extraction the root - analogues were placed into the extraction sockets and restored with single crowns [ 39 , 40 ] . after 1 year of functional loading , the customized implants showed excellent integration in the bony tissue , with almost perfect functional and aesthetic outcome [ 39 , 40 ] .
after these first reports , a prospective clinical study evaluated the survival and success rate of dmls , root - analogue implants , placed into the extraction sockets of 15 patients .
cbct images of 15 nonrestorable premolars were acquired and transformed into 3d models : from these , custom - made , root - analogue dmls implants with integral abutment were fabricated .
immediately after tooth extraction , the root - analogues were placed in the sockets and restored with single crowns . at the 1-year follow - up ,
the optimal conditions of the peri - implant tissues were confirmed by the radiographic examination , with a mean dib of 0.7 mm ( 0.2 ) .
the authors concluded that the dmls technique offers a novel and interesting perspective for the immediate placement of customized dental implants . in total , 12 histologic / histomorphometric studies on dmls implants were found in the current literature ( 6 were animal studies and 6 were human studies ) [ 15 , 17 , 4352 ] .
the animal studies were conducted on dmls titanium implants / scaffolds with different geometric characteristics and porosity [ 15 , 17 , 4347 ] .
van der stok and colleagues studied the biological response to two different titanium dmls scaffolds with struts of 120 m ( titanium-120 ) or 230 m ( titanium-230 ) in a load - bearing critical femoral bone defect in rats .
the defects were stabilized with an internal plate and treated with titanium-120 or titanium-230 or left empty . in vivo micro - ct scans at 4 , 8 , and 12
weeks showed more bone in the defects treated with scaffolds : 18.4 7.1 mm ( titanium-120 , p = 0.015 ) and 18.7 8.0 mm ( titanium-230 , p = 0.012 ) of bone were formed in those defects , significantly more than in the empty defects ( 5.8 5.1 mm ) .
this study demonstrated that , in addition to adequate mechanical support , porous titanium scaffolds can facilitate bone formation , which results in high mechanical integrity of the treated large bone defects . in another histologic / histomorphometric study ,
de wild and colleagues investigated the in vivo bone formation with different dmls porous titanium implants ( with their surfaces either left untreated , sandblasted , or sandblasted - acid etched ) placed into calvarial bone defects in rabbits and compared to untreated defects . in this study ,
dmls implants had an open porous lattice and a stepped cylindrical shape with an upper outer diameter of 7.5 mm , a lower outer diameter of 6 mm , and a height of 3.8 mm , while rod thickness was set at 200 m .
the open porous channels with a quadratic cross section of 700 m 700 m were designed with an overall porosity of 83.5% . at the end of the study , bone augmentation beyond the original bone margins
was only seen in implant treated defects , indicating a high osteoconductive potential of the dmls implants .
analysis by ct and histomorphometry revealed that all the porous titanium structures were well osseointegrated into the surrounding bone .
however , the histomorphometric analysis revealed that bone formation significantly increased in the dmls sandblasted implants compared to dmls untreated ones and bone bridging was significantly increased in dmls sandblasted - acid etched scaffolds , thus suggesting that scaffolds manufactured by dmls should be surface - treated .
the authors concluded that designed porous , lightweight structures have potential for bone regeneration and augmentation purposes , particularly when patient - specific geometries are needed .
fukuda and colleagues tested the effects of interconnective pore size of titanium dmls scaffolds on osteoinductivity and the bone formation processes .
dmls was employed to fabricate porous titanium scaffolds ( diameter 3.3 mm , length 15 mm ) with a channel structure comprising 4 longitudinal square channels , representing pores of different widths ( 500 , 600 , 900 , and 1200 m , resp . ) .
the dmls scaffolds were implanted in the dorsal muscles of 8 mature beagle dogs , remaining for periods of 16 , 26 , or 52 weeks .
this study supports the hypothesis that the geometric properties of the dmls scaffolds ( characterised by an open interconnective porosity with pores of controlled size ) can give rise to new bone formation even in extraskeletal sites . in a similar study , pattanayak and
colleagues investigated the biological response to highly porous dmls titanium scaffolds when installed into the femur of japanese white rabbits .
twelve weeks after implantation , the histologic evaluation showed excellent osteoconductive properties for the dmls scaffolds , with substantial amount of new bone penetrating into the pores and directly bonding to the walls within the implants .
stbinger and colleagues placed three different types of implants ( machined , sandblasted - acid etched , and dmls implants ) in the pelvis of six sheep . in this case , the dmls implants were characterised by a porous surface and a dense titanium core . after 2 and 8 weeks , bone - to - implant contact ( bic ) values of the dmls surface ( 2 weeks : 20.4% 5.1% ; 8 weeks : 43.9% 9.6 ) revealed no statistical significant differences in comparison to the machined ( 2 weeks : 20.3% 11.5% ; 8 weeks : 25.3% 4.6% ) and sandblasted - acid etched ( 2 weeks : 43.6 12.2% ; 8 weeks : 53.3 8.9% ) surfaces .
however , removal - torque - tests showed a significant improvement in fixation strength ( p < 0.001 ) for the dmls ( 1891.8 308.4 nmm ) surface after 8 weeks in comparison to the machined ( 198.9 88.0 nmm ) and sandblasted - acid etched ( 730.0 151.8 nmm ) surfaces .
similar results were obtained in another study by witek and colleagues , where dmls and sandblasted - acid etched implants ( one per type ) were placed in the radius of 18 beagle dogs , remaining for 1 , 3 , and 6 weeks ( n = 6 dogs per evaluation time ) in vivo .
a significantly higher bic was observed for dmls implants ( p < 0.04 ) only at 1 week , whereas no significant differences were found at 3 and 6 weeks ; however , a significantly higher torque was observed at 1 ( p < 0.02 ) and 6 weeks ( p < 0.02 ) for the dmls implants , whereas at 3 weeks no significant differences were observed .
the authors concluded that the dmls implants presented biocompatible and osseoconductive properties and improved biomechanical response compared with the sandblasted - acid etched implants at 1 and 6 weeks in vivo .
all human studies were based on dmls titanium implants with a porous surface and a dense titanium core [ 15 , 4852 ] .
shibli and colleagues investigated the influence of dmls surface topography on bone - to - implant contact ( bic ) , on bone density in the threaded area ( ba ) , and on bone density outside the threaded area ( bd ) in type iv bone after 8 weeks of unloaded healing . in total , 30 patients received 1 microimplant ( 2.5 mm diameter and 6 mm length ) in the posterior maxilla .
thirty microimplants with three different topographies were evaluated : 10 machined ; 10 sandblasted - acid etched surface ( sae ) , and 10 dmls microimplants .
after 8 weeks , the microimplants and the surrounding tissues were removed and prepared for the histomorphometric examination .
the histomorphometric analysis revealed that the mean bic was higher for the dmls and sae surfaces ( p = 0.0002 ) .
the ba was higher for the dmls surface , although there was no significant difference with the sae surface , while the bd was similar for all topographies ( p > 0.05 ) .
the study suggested that the dmls and sae surfaces presented a higher bic rate compared with machined surfaces under unloaded conditions , after a healing period of 8 weeks . in another study by the same group of researchers ,
after 8 weeks , the microimplants and the surrounding tissue were removed and prepared for the histomorphometric analysis , scanning electron microscopy ( sem ) , and x - ray dispersive spectrometry ( eds ) evaluation .
the sem and eds evaluation showed a close relation between newly formed bone matrix and dmls surface , in accordance with the histological features .
this study confirmed that the dmls surface can provide an optimal stratum to bone tissue ingrowth .
these results confirmed those of a previous report by mangano and colleagues where one dmls microimplant was inserted in the anterior mandible of a patient , retrieved after 8 weeks of unloaded healing with the surrounding tissues , and prepared for histomorphometric analysis .
histologically , the peri - implant bone appeared in close contact with the implant surface , whereas marrow spaces could be detected in other areas along with prominently stained cement lines .
12 totally edentulous patients received dmls transitional implants in the posterior maxilla , 2 implants per patient .
twelve implants were immediately loaded , to support an interim complete maxillary denture during the healing period , while the other 12 were left unloaded .
eight weeks after surgery , the transitional implants and the surrounding tissue were removed and prepared for histomorphometric evaluation .
histometric evaluation indicated that the mean bic was 45.2 7.6% and 34.1 7.8% for immediate loaded and unloaded implants , respectively ( p < 0.05 ) .
although these data must be considered with caution , because of the inherent limits of this study , both immediately loaded and unloaded dmls implants showed a high bic in the posterior maxilla . since x - ray micro - ct can provide rapid , nondestructive 3d images and measurements on bone microstructure , the interface between bone tissue and dmls titanium implants has been studied accordingly . in particular ,
high resolution micro - ct has been achieved with synchrotron radiation - based computed microtomography ( srmct ) .
two dmls titanium microimplants were inserted in the posterior maxilla of a patient and retrieved after 8 weeks .
one of these implants was treated to obtain thin ground sections , for histological evaluation , whereas the other underwent a srmct evaluation .
the histological evaluation revealed a bic of 65.2% : the newly formed bone was primarily composed of woven bone connecting the peri - implant bony trabeculae to the microimplant surface .
the implant surface showed superficial debris or particle inclusions in the surrounding tissue close to the bone area .
finally , a study evaluated the peri - implant soft tissues around human - retrieved dmls microimplants .
twenty - four microimplants were inserted in the posterior maxilla of 12 patients ( two implants per patient ) . in order to evaluate the behaviour of the peri - implant soft tissues , the neck of the implants had two different surface topographies , dmls topography ( test group ) and acid - etched surface topography only ( control group ) .
after 8 weeks , all the implants and the surrounding tissue were removed and prepared for histomorphometric evaluation . in the control specimens
, collagen fibers were oriented perpendicular to the surface for a distance of 100 m , whereafter they became parallel , running in several directions . in the test specimens , a more intimate contact of the fibrous matrix with the implant surface was evidenced , with the collagen bundles more perpendicularly oriented to the dmls surface .
the authors concluded that , by changing the surface microtexture , it is possible to change the response of the peri - implant soft tissues . as reported previously ,
no rct could be identified , and thus only the outcomes of prospective observational studies ( e.g. , case series , case - control , and prospective cohort trials ) could be assessed .
the methodological quality of included observational studies [ 15 , 35 , 37 , 42 , 48 , 5052 ] is depicted in figure 2 . all of these studies were considered to have a medium methodological quality , except for the paper by mangano et al .
titanium and its alloys are widely used for various implants , in the orthopaedic and dental fields , because of good corrosion resistance , high osteoconductivity , and mechanical strength [ 14 , 27 , 29 , 44 , 5356 ] . however , young 's modulus of ( 105 gpa for pure ti ) and + titanium alloys ( 110 gpa for ti-6al-4v ) is about 310 times higher than that of bone ( 1030 gpa ) .
this mismatch of modulus between metallic implant and surrounding bone can cause stress shielding effects , which eventually lead to bone resorption [ 14 , 27 , 29 , 44 , 5356 ] . in orthopaedics ,
bone resorption caused by stress shielding represents a major problem , as it is believed to contribute to highly undesired effects such as aseptic loosening of implants [ 27 , 29 , 44 ] .
one approach for reducing stress shielding is to use porous metallic biomaterials : if a considerable amount of interconnected pores is introduced into them , their elastic moduli may significantly decrease . in the study of traini and colleagues , surface appearance , microstructure , composition , mechanical properties , and
the results of the mechanical tests indicated that dmls resulted in a functionally graded material , with a compact sintered titanium core ( 104 7.7 gpa ) with a modulus similar to that of machined titanium , while the modulus of the porous titanium present on the implant surface was reduced ( 77 3.5 gpa ) and more
the authors concluded that dmls implants may show better adaptation to the elastic properties of the bone .
sallica - leva and colleagues investigated the influence of the microstructure on the mechanical properties of dmls implants .
the authors concluded that the mechanical properties of the parts obtained by dmls fall in a range that is interesting for bone substitution applications .
in addition , a comparison between these results and those of porous parts with similar geometry obtained by electron beam melting ( ebm ) technology showed that the use of dmls allows parts with higher mechanical properties for a given relative density to be obtained .
amin yavari and colleagues studied the fatigue behaviour of porous structures made of ti6al4v using dmls .
four different porous microarchitectures were manufactured with high porosities ( between 68% and 84% ) and the fatigue s - n curves of these structures were determined . at the end of the study ,
in general , given the same absolute stress level , the fatigue life was much shorter for more porous structures . the authors concluded that the normalized endurance limits of the tested structures were lower than that of solid titanium ( with similar alloy ) and that of some other porous titanium structures manufactured using other techniques .
step - stress accelerated life testing ( ssalt ) and fractographic analysis were performed to compare the reliability and failure modes of dmls and sandblasted - acid etched ( sae ) implants used for anterior single - unit replacements .
forty - two standard dental implants ( 3.75 mm 10.0 mm ) were used ; among these implants , 21 were fabricated with dmls technology while the other 21 were sae implants .
the abutments were screwed to the implants and standardized maxillary central incisor metallic crowns were cemented and subjected to ssalt in water . at the end of the study , no differences in reliability and fracture mode were observed between dmls and sae implants used for anterior single - unit crowns .
these findings suggested that dmls technology titanium implants may not affect the implant fatigue endurance .
the surface produced with dmls has been investigated and characterised using scanning electron microscopy ( sem ) [ 14 , 27 , 28 ] , stereo - scanning electron microscopy ( stereo - sem ) , and atomic force microscopy ( afm ) .
the sem and stereo - sem evaluations revealed a porous surface , with a pore network extending 200 m beneath the surface ; the surface was characterised by deep , intercommunicating crevices , shallow depressions , and deep , rounded pits of widely variable shape and size ( figure 3 ) [ 14 , 27 , 28 , 56 ] .
the roughness parameters were rt , 360.8 m ; rz , 358.4 m ; ra , 67.4 m ; and rq , 78.0 m .
this porous network with high values of microroughness may influence the shape that cells adapt within the 3d cavities , inducing a specific genetic expression [ 14 , 16 , 19 , 2729 ] .
the afm evaluation evidenced that the dmls surface geometry may represent a valid substratum for protein adsorption , consequently facilitating cell adhesion . after the complete morphological characterization , studies on cell cultures have investigated the biological response to dmls surface [ 27 , 28 , 57 , 58 ] . in the first in vitro investigation , hollander and colleagues cultured human osteoblasts on porous blasted dmls specimens to study morphology , vitality , proliferation , and differentiation of the cells , at 3 , 7 , and 14 days . at day 14 , the cells were vital and proliferating . on porous specimens ,
osteoblasts grew along the rims of the pores and formed circle - shaped structures , as visualized by live / dead staining as well as sem .
this first in vitro experiment demonstrated that dmls - fabricated ti-6al-4v allowed structure - oriented growth of human osteoblasts on its surface .
these results were confirmed by another study on cell cultures , where rat calvarial osteoblasts were seeded and cultured on disc specimens produced by dmls .
after 9 days , cells had attached to and spread on the surface ; they were irregularly shaped , predominantly attached to protruding features , and spanned across intervening crevices by means of extended tightly stretched processes .
higher magnification images showed that where a cell body or lamellipodium contacted the surface , it was closely adherent and occluded the microcavities beneath .
cell density was similar to that on a commercial rough microtextured surface but lower than on machined and smooth - textured grit - blasted , acid etched surfaces .
in the same study , human fibrin clot extension on the dmls surface was investigated .
more recently , matena and colleagues analysed the proliferative behaviour of primary osteoblasts and an endothelial cell line when cultured on dmls titanium scaffolds .
the osteoblasts were able to proliferate and migrate on the dmls titanium surface , and they could be visualized up to 210 m in depth of the pores .
the authors concluded that the establishment of an in vivo model to evaluate the dmls titanium scaffold appears to be promising .
finally , in another in vitro study , human osteoblasts and stem cells derived from human dental pulps ( dental pulp stem cells , dpscs ) were cultured either on acid - etched ( ae ) or on dmls titanium surfaces , in order to investigate their osseointegration and clinical use capability of derived implants .
the cells were challenged with the two titanium surfaces , either in plane cultures or in a roller apparatus within a culture chamber , for hours up to a month .
the cultured cells on the titanium surfaces were examined for histology , protein secretion , and gene expression .
it was also shown that these cells were capable of differentiating quickly into osteoblasts and endotheliocytes and , then , able to produce bone tissue along the implant surfaces .
osteoblast differentiation of dpscs and bone morphogenetic protein production was obtained in a better and quicker way , when challenging stem cells with the dmls titanium surface . these successful results in a short time suggested that dmls titanium surfaces may represent a promising alternative for clinical use in dental implantology .
in recent years , according to the modern concepts of bone tissue engineering , macroporous structures have been extensively investigated .
these porous scaffold materials should be designed to stimulate bone ingrowth so as to enhance implants fixation but must also be able to withstand the load bearing demands .
it is difficult if not impossible to fabricate a titanium scaffold with controlled porosity and open pore internal architecture via conventional manufacturing routes .
am techniques such as dmls can provide complete control over the microarchitecture of porous titanium implants .
this enables the possibility of tailoring and optimizing the structural and mechanical properties of the implants , while maintaining the required pore dimensions that allow for bone and vessel ingrowth .
a number of studies have demonstrated the potential for the use of dmls titanium implants .
the chemical and physical properties of dental implants fabricated with the dmls technique have been characterised .
the biologic response to the dmls implant surface has been investigated in different in vitro studies , in which human fibrin clot formation and the behaviour of human osteoblasts and mesenchymal stem cells were analyzed .
the behaviour of dmls implants has been investigated in vivo in histologic and histomorphometric studies in both animals and humans , and satisfactory outcomes were reported .
the first clinical studies on dmls titanium dental implants have reported satisfactory short - term results .
in all these studies , dmls implants were designed with a porous surface and a dense titanium core .
however , further studies that clearly demonstrate benefits of dmls implants over conventional implants are needed . in particular , as dental implants are expected to survive long periods , further prospective studies are needed , to investigate the clinical performance of dmls implants in the long - term
; in addition , it would be important to understand better the fatigue mechanical behaviour of implant systems fabricated by dmls .
further development and advances in dmls will require optimal scaffold design and the input of enhanced knowledge of cell physiology , including optimal cell seeding and vascularization ; in addition , the application of surface treatments may potentiate the biological response to dmls titanium implants .
nevertheless , the introduction of dmls technology signals the start of a new revolutionary era for implant dentistry as its immense potential for producing highly complex macro- and microstructures is receiving considerable interest in a wide variety of medical fields . | ### Summary:
: statement of problem .
direct metal laser sintering ( dmls ) is a technology that allows fabrication of complex - shaped objects from powder - based materials , according to a three - dimensional ( 3d ) computer model .
with dmls , it is possible to fabricate titanium dental implants with an inherently porous surface , a key property required of implantation devices . objective .
the aim of this review was to evaluate the evidence for the reliability of dmls titanium dental implants and their clinical and histologic / histomorphometric outcomes , as well as their mechanical properties .
materials and methods .
electronic database searches were performed .
inclusion criteria were clinical and radiographic studies , histologic / histomorphometric studies in humans and animals , mechanical evaluations , and in vitro cell culture studies on dmls titanium implants .
meta - analysis could be performed only for randomized controlled trials ( rcts ) ; to evaluate the methodological quality of observational human studies , the newcastle - ottawa scale ( nos ) was used .
results .
twenty - seven studies were included in this review .
no rcts were found , and meta - analysis could not be performed .
the outcomes of observational human studies were assessed using the nos : these studies showed medium methodological quality .
conclusions .
several studies have demonstrated the potential for the use of dmls titanium implants . however , further studies that demonstrate the benefits of dmls implants over conventional implants are needed . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: sleep disturbances can interfere with normal physical , mental , and emotional functioning and have been reported in hiv - infected individuals since the 1980 's [ 14 ] .
hiv - infected individuals have been known to have a high prevalence of sleep disturbance , between 40 and 70% [ 57 ] .
earlier studies have reported high rates of neuropsychiatric side effects including insomnia in patients on efavirenz based therapies .
efavirenz is known to increase sleep latency and decrease sleep duration with symptoms resolving usually within the first weeks of treatment [ 8 , 9 ] .
most cns symptoms of efavirenz including insomnia are mild but some patients change therapy because of unbearable neurotoxicity .
other clinical studies have reported increased serum levels of efavirenz and higher rates of neuropsychiatric disorders in patients of african origin [ 10 , 11 ] .
it is thought that the defective cyp2b6 g516 t variant allele which is common in african population impairs efavirenz metabolism , thus increasing efavirenz plasma concentrations , thereby leading to toxicity [ 12 , 13 ] .
other psychosocial causes of sleep disturbances in the hiv population include anxiety over the illness , financial concerns , stigmatization , depression , suicidal thoughts , and unemployment .
sleep disturbances occur throughout the stages of infection , being more prevalent in the advanced stage [ 15 , 16 ] .
it can lead to impairment of attention , concentration , fatigue , memory , mood swings , and reduction in energy levels [ 17 , 18 ] .
it may also increase the risk for psychiatric disorders , cardiovascular morbidity , and mortality and health care utilization [ 1821 ] .
results from recent studies have shown that hiv individuals with sleep problems are less likely to adhere to their antiretroviral therapy regimens probably as a result of depression [ 2224 ] .
nonadherence may result in treatment failure , disease progression , and the development of resistant strains [ 25 , 26 ] .
sleep disorders in hiv population are treatable with early therapy effectively lowering the risk of these complications .
management includes the use of pharmacologic agents such as benzodiazepines , nonbenzodiazepine hypnotics , and antidepressants and psychological and behavioural treatments such as cognitive behavioural therapy and improved sleep hygiene . with the increasing life expectancy in hiv individuals , sleep disturbances
determining the quality of sleep and its effects could prevent resultant complications that may arise .
we aimed to determine the quality of sleep and its associated factors including efavirenz based therapies in our african population of hiv - positive individuals .
this is a cross - sectional study conducted at the hiv clinic of the lagos state university teaching hospital ( lasuth ) between january and september 2013 .
the study enrolled patients attending the hiv clinic , who were at least 18 years , diagnosed with hiv infection , on antiretroviral therapy , not working nightshift schedules , and not pregnant within the prior 3 months .
exclusion criteria included recent use of hard / illicit drugs or alcohol , depression , current or recent suicidal ideation , and the presence of any acute medical condition that could affect the participant 's sleep , cognitive function , or ability to complete the study questionnaire .
the hospital ethics committee approved this research , and each participant gave informed consent . after signing informed consent , information regarding the participant 's demographic data , educational qualification , and marital status
their treatment history , including duration of hiv diagnosis , the most recent laboratory results for cd4 cell count , and current antiretroviral therapy , was also obtained from their case records .
each participant was administered the psqi , a 19-item questionnaire that assesses sleep components including sleep quality , sleep latency , sleep duration , habitual sleep efficiency , sleep disturbances , use of hypnotics , and daytime dysfunction during the last month .
the psqi has been used and validated in different settings for the measurement of quality and pattern of sleep in adults .
each individual component receives a score from zero to three , with the final score on the instrument ranging between 0 and 21 .
the higher the score , the worse the quality of sleep , and scores 5 indicate poor sleep quality .
continuous variables such as participant 's age , hiv diagnosis duration , cd4 cell count , and psqi score are presented as mean standard deviation ( sd ) and comparison between groups was made using multivariate logistic regression analysis .
categorical variables ( e.g. , gender , marital status category , haart group category , and cd4 cell count category below or above 200 cells / mm ) are presented as frequencies ( % ) and group differences compared using nonparametric yates corrected x test .
the characteristics of the 300 participants included in this analysis are summarized in table 1 .
the sample was predominantly female and all were on antiretroviral therapy , with a mean duration of 27.5 33.3 months at the time of the study . according to the psqi ,
those with good sleep quality were 42 males and 80 females with ages ranging between 25 and 70 years ( mean 39.1 9.4 ) whilst those with poor quality sleep were 46 males and 132 females with ages ranging between 18 and 74 years ( mean 38.7 10.9 ) ; p = 0.78 .
the psqi scores of those with poor quality sleep ranged between 5 and 19 with a mean of 9.2 3.3 ( median 9.0 ; range 14 ) whilst that of those with good quality sleep ranged between 0 and 4 with a mean of 1.26 1.4 ( median 1.0 ; range 4 ) ; p < 0.001 .
the characteristics that showed a significant association with the participants ' quality of sleep are listed in table 2 .
age , gender , educational qualification , and marital status were not significantly associated with the quality of sleep .
the relationship between each of the significant correlates ( duration since hiv diagnosis , efavirenz based regimen , and lower cd4 cell count ) and sleep quality was further examined using multivariate logistic regression models ( table 3 ) .
the individual component scores of the psqi were compared in patients with good and poor quality sleep in table 4 .
in this study , using the psqi questionnaire , we assessed sleep quality in our outpatients hiv cohort over the last month and observed that 59.3% of cases had poor quality sleep .
this rate is high and in the range of that documented in comparable studies that have assessed sleep quality using the psqi .
ferreirra and ceolm had documented slightly lower rates of 46.7% and 46% , respectively [ 28 , 29 ] .
. we had excluded cases with the use of hard drugs and alcohol , depression , and suicidal ideation from our study .
varying prevalent rates of sleep disturbances in people living with hiv have been documented in literature probably as a result of the difference in the diagnostic criteria of sleep disturbances [ 30 , 31 ] .
our findings are however similar to those in other studies that have documented high rates of sleep disturbances in the era of haart [ 32 , 33 ] .
it is worthy to note that our hiv population live in a highly urbanized area where other causes of sleep disturbances exist .
lagos state with its high population , high level of night time social activities , and night time road traffic noise pollution may be contributory to this high prevalence .
studies have shown that urban population living in noisy areas have a higher risk of sleep disturbances .
the mean total psqi score in the cases with poor quality sleep in our study was 9.2 .
nokes and kendrew and hand et al . had documented similar scores of 10.0 and 12.3 , respectively , in their cohorts [ 35 , 36 ] .
we also noted a significant difference in all the components of sleep quality assessed in poor sleepers compared with those with good quality sleep .
sleep architecture in hiv patients is characterised by increased sleep latencies , frequent nocturnal awakenings , a reduction in the hours of sleep , early morning awakening with a reversal of the slow wave sleep , and rapid eye movement sleep patterns . all these are thought to be as a result of underlying immune dysfunction .
though the regulation of cytokines in the brain is complex , it is known that some cytokine - associated substances , such as the il1ra and the tnf and il1 soluble receptors , act as endogenous antagonists , inhibiting spontaneous sleep . also elevated levels of ils 2 , 4 , 6 , 8 , 10 , 13 , and 18 ; ifns , , and ; and transforming growth factor cause a decrease in nrem sleep [ 39 , 40 ] .
growth hormone dysregulation together with the physiologic coupling that has been demonstrated between alpha tumor necrosis factor and delta wave amplitude may also contribute to this sleep pathology .
there have been inconsistent reports on the relationship between cd4 cell count and poor sleep quality .
some studies [ 35 , 41 , 42 ] have not found any relationship whilst others have confirmed that sleep disturbances are independently related to immune status [ 37 , 43 , 44 ] .
we noted a significant association between poor quality sleep and lower mean cd4 count in our study .
research has shown that the immune system is directly linked to the psyche by a complex network of nerves , hormones , and neuropeptides .
this network of specific physiological pathways allows immune function to have a direct impact on health especially sleep .
we noted that a significant proportion of patients on efavirenz based haart therapy had poor quality sleep .
other earlier studies had also documented a correlation between high blood concentrations of efavirenz and poor sleep pattern [ 44 , 45 ] .
had performed ambulatory electroencephalogram monitoring on hiv - infected subjects treated with efavirenz and found that those receiving efavirenz had longer sleep latencies and shorter duration of deep sleep .
also , efavirenz plasma levels were significantly higher in patients with insomnia and/or reduced sleep efficiency .
it had been suggested that a direct inhibition of serotonergic hypothalamic pathways by efavirenz may explain this .
this may also be attributed to the presence of the defective cyp2b6 g516 t variant allele known to be common in black africans , in our cohort .
this genetic abnormality causes a variation in the rate of efavirenz metabolism thereby significantly increasing the likelihood of the occurrence of sleep disturbance . in our study
, the length of time from hiv diagnosis was found to be associated with sleep disturbances , with a significant association between shorter duration from diagnosis and poor quality of sleep .
hiv infection is a highly stigmatized illness with a sense of dejection and loss of self - esteem , all symptoms of depression and normal emotional responses to the reality of living with hiv .
these may explain the higher rate of sleep disturbances in the months , soon after diagnosis .
this finding however is conflicting with that of other studies that have assessed sleep disturbances in relation to duration of infection .
the results of this study indicate that sleep disturbances are quite common in people living with hiv infection in this population with an anticipated negative impact on the quality of life .
early recognition via routine assessment and implementation of effective medical and behavioural treatments could improve functioning and reduce complications .
future studies are required to determine the frequency of the genetic polymorphism affecting efavirenz metabolism in the african population .
more studies need to be conducted to determine if the genetic testing can help individualize therapy , avoid toxicity , and maximize efficacy .
treatment guidelines for proper management of sleep disturbances in the hiv population need to be designed whilst taking into consideration drug interactions . | ### Summary:
: aim . to determine the prevalence of sleep disturbance and its associated characteristics in hiv - positive outpatients on haart using the psqi
. methods . using a cross - sectional design , 300 patients attending the outpatient hiv / aids clinic at the lagos state university teaching hospital were recruited .
baseline data obtained included the participants ' demographic data , educational qualification , and marital status . their treatment history , including duration since hiv diagnosis , the most recent cd4 cell count , and current antiretroviral therapies , was obtained from their case records .
each participant completed the psqi questionnaire and those with scores 5 were diagnosed with poor sleep quality .
results .
the participants were made up of 70.7% females and 29.3% males .
their ages ranged between 18 and 74 years with a mean of 38.9 10.3 years . according to the psqi ,
59.3% reported poor sleep quality .
the mean score of those with poor quality sleep ( 9.2 3.3 ) was comparable to that of those with good quality sleep ( 1.26 1.4 ) .
p < 0.001 .
significant differences were observed in all the individual components of the psqi ( p < 0.001 ) .
on multivariate analyses , the independent associations with sleep quality were the duration since hiv diagnosis ( p = 0.29 ) , efavirenz based regimen ( p < 0.001 ) , and lower cd4 cell count ( p < 0.001 ) . conclusions .
sleep disturbances are quite common in the hiv population even in the era of haart .
early recognition via routine assessment and effective treatments could prevent the resultant complications and improve quality of life . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: in 2002 , the cloning of apobec3 g ( a3 g ; then called cem15 ) and the identification of the protein product of this gene as the first cellular protein capable of restricting hiv-1 infection revealed a novel direction for chemotherapeutic intervention and ignited the search for additional defense proteins capable of counteracting viral invasion .
the report of this cloning solved a long - standing enigma in the field of hiv-1 pathogenesis .
early work examining and comparing the pathogenesis of wild - type and vif - deficient hiv-1 had yielded conflicting results with some laboratories concluding that vif was dispensable for productive infection while other groups maintained that vif expression was essential [ 24 ] .
ultimately , it was decisively shown that the requirement for vif was cell - type dependent ; permissive cells supported the growth of hiv-1vif while nonpermissive cells limited such viral replication [ 5 , 6 ] .
most interesting and relevant was the inability of vif - deficient hiv to productively infect primary cd4 + t cells , one of the critical natural targets of hiv-1 infection [ 2 , 3 , 5 , 7 , 8 ] .
the molecular explanation for the vif phenotype remained unexplained for the subsequent decade . proffered in this early work
an equally valid suggestion was that nonpermissive cells harbored an inhibitory activity of hiv-1 that was itself overcome by the vif protein .
it was subsequently established , in a pair of elegant experiments utilizing heterokaryons formed from fusion of nonpermissive and permissive cell lines that , in fact , nonpermissive cells expressed an activity that suppressed hiv-1vif replication [ 9 , 10 ] .
the genetic relatedness of two t lymphocyte lines , one nonpermissive and the other permissive , was exploited in a classical subtractive hybridization experiment ; a3 g was identified as this described suppressive activity .
it was found to be almost exclusively expressed by nonpermissive cells and its stable expression in permissive cells conveyed the ability to resist an hiv-1 challenge .
it was quickly appreciated that a3 g was but one family member of a previously identified gene locus .
subsequent investigation also revealed that a3 g exhibited a potent dna - mutating ability . in humans , seven family members within the locus have been identified ; rhesus macaques , the nonhuman primate that serves as the most important animal model for hiv treatment and vaccine testing , also have seven apobec3 genes , while the murine genome contains a single a3 gene [ 1315 ] . in each of these organisms ,
all seven a3 family members identified in humans exhibit powerful suppressive activity against a range of viruses while the homologous proteins in mice and primates appear to perform similar functions [ 1618 ] .
while a3 inhibitory activity is relatively broad , the most well - characterized and studied function is their striking ability to restrict retroviral infection . in an evolutionary response to this restriction ,
the retroviruses have countered with a battery of genes exquisitely fine - tuned to overcome these endogenous defense proteins .
with one exception ( a3c ) , each of the seven a3 family members in humans has been observed to be capable of combating hiv-1 [ 1 , 17 , 2027 ] .
whether the antiviral activity observed is relevant during the course of a natural hiv-1 infection has not been unequivocally established for any of the family members and there are valid concerns raised in the interpretation of various data regarding levels of protein expression and potency .
however , it is becoming increasingly clear that understanding the battle that is waged between the innate immune system and hiv-1 during acute infection is imperative and the a3 proteins are critical players in this initial encounter .
while the relative potencies of individual a3 family members in the setting of a natural infection have been difficult to assess , it has been convincingly established that , in the tissue culture setting , a3 g exhibits the most potent activity against hiv-1 . in a variety of cell types , both primary cells and established cells lines , and under varying experimental conditions , including both single - round infectivity assays and multiple - round replication assays , a3 g suppresses the infectivity of hiv-1 .
hiv-1 vif has evolved to counteract this impressive activity of a3 g by preventing virion encapsidation of this host factor [ 2835 ] .
vif acts as an adapter protein bridging a3 g and a cullin5-elongin b / c - rbx ubiquitin ligase . within this complex a3 g
other modalities involving vif prevention of a3 g encapsidation have also been documented [ 28 , 32 , 34 ] .
interestingly , dominance of a3 g over vif has been noted under conditions of elevated and/or stabilized expression [ 1 , 34 , 36 ] .
this ability to suppress hiv-1 even in the presence of vif is noteworthy as it has distinct implications for the development of chemotherapeutics designed to interfere with the a3 g : vif axis .
its most extensively characterized anti - hiv-1 function is its ability to catalyze cytidine deamination of hiv-1 dna on the minus strand resulting in the detection of guanosine - to - adenosine transition mutations in reverse transcripts ; upwards of 10% of guanosines may be mutated leading to the labeling of this a3g - mediated process as hypermutation [ 34 , 38 , 39 ] .
the fate of such hypermutated transcripts is not well understood , but certainly this dramatic mutational burden effectively short - circuits viral infection .
work from multiple groups has also uncovered deamination - independent anti - hiv effects of a3 g that are seen during viral infection [ 22 , 4049 ] .
the characterization of this editing - independent antiviral function has suggested a block to viral replication that occurs after entry but before integration . while the molecular details of this deaminase - independent function of a3 g remain unclear , defective reverse transcription products
are commonly observed , indicating that a3 g likely acts during the process of reverse transcription .
all members of the a3 family contain at least one conserved cytidine deaminase active site ( cda ; family members a3b , a3d , a3f , and a3 g contain two such domains ) composed of the signature sequence his / cys - x - glu - x2328-pro - cys - x2-cys [ 11 , 15 ] .
early structure - function analysis of a3 g was performed by disrupting these suspected catalytic domains with site - directed mutagenesis .
the conserved histidine , glutamic acid , and cysteine resides in both the n - terminal and c - terminal domains of a3 g were individually mutated and the resulting proteins were independently examined for their catalytic function as well as their ability to suppress hiv-1vif infection .
the data clearly indicated that the c - terminal cda domain was responsible for a3 g enzymatic function .
unexpectedly the data also suggested that , under specific experimental conditions , significant anti - hiv-1 inhibition could be imparted in the absence of the characteristic mutagenic activity .
controversy over these observations primarily stems from claims that these data have most often been cited in experimental settings using mutant a3 g exhibiting elevated expression levels [ 41 , 42 , 50 , 51 ] . in attempts to clarify the role of a3 g expression levels a number of groups
have compared a3 g protein expression in transiently transfected cell lines and primary cd4 + t cells / macrophages , reporting that expression levels achieved during transient transfection exceed levels observed in primary cells . however , a few cautionary notes are warranted .
g that is mutated , for instance , at the critical glutamic acid at residue 259 of the protein , has also been shown to have a more limited ability to block the process of reverse transcription thereby suggesting that distinguishing deamination - dependent and -independent activities may be challenging .
additional support for a pleiotropic antiviral function of a3 g is provided by observations in which the a3 g phenotype is unaffected in cells that do not express uracil dna glycosylase 2 or smug , enzymes responsible for the removal of uracils from single- or double - stranded dna [ 52 , 53 ] . as a significant suppressor of hiv-1 , a multipronged ability of a3 g to inhibit hiv-1 would have notable benefits to the invaded host . using a variety of cell lines and experimental conditions , the anti - hiv-1 activity of a3b , a3d , a3f , and a3h ( haplotypes i , ii , v , and vii ) has also been conclusively demonstrated [ 17 , 20 , 21 , 2325 , 27 , 54 , 55 ] .
hypermutation is often recorded as coincident with antiviral activity , although , in the case of a3b and a3f , as with a3 g , there are observations of hiv-1 suppression in the absence of hypermutation [ 24 , 42 , 43 ] . sensitivity to vif regulation has been observed for a3d , a3f , a3 g and a3h while a3b and a3h / haplotype i resist vif - mediated virion exclusion and thus exhibit detectable activity against wild - type hiv-1 virus .
however , not all of these family members are equally likely to contribute to hiv-1 resistance during a natural infection ; a3b is primarily expressed in b cells and makes it unlikely that this protein contributes appreciably to inhibition of hiv-1 [ 17 , 20 , 21 , 23 , 24 , 5658 ] .
similarly , the expression of the a3h / haplotype i restricts wildtype hiv-1 , but the protein is inherently unstable [ 20 , 56 ] .
a question with important clinical implications is whether this intrinsic instability may be overcome while harnessing the natural power to combat wild - type viral infection [ 58 , 59 ] . until recently ,
the role of a3a in hiv-1 inhibition was unappreciated outside of two significant observations : the first being a correlation between its expression in monocytes and the susceptibility of these cells to hiv-1 infection , and the second was that expression of a3a was confined to cells of the myeloid lineage and this expression was positively regulated by inf- [ 6062 ] .
have now described a novel and critical role a3a plays in the early phase of hiv infection , specifically in myeloid cells .
when primary myeloid cells were infected with hiv-1 and the induction of expression at the a3 locus was examined , it was shown that these cells preferentially induced a3a , on both the mrna and protein levels ; induction of other a3 family members in these cells was not detected and a3a induction in peripheral blood lymphocytes was negligible .
the induced a3a was protective upon hiv-1 challenge and depletion of a3a in primary macrophages and dendritic cells increased viral replication in both single - round infectivity assays and a spreading infection .
similar to other a3 proteins this viral restriction was primarily observed as a profound suppression in the accumulation of viral dna suggesting interference with an early step of reverse transcription ; limited editing of viral reverse transcripts was detectable , but the evidence suggested that enzymatic function was not the sole antiviral function . notwithstanding its common role as an a3 family member involved in hiv-1 control ,
it is not producer cell - derived a3a that impacts virus replication , but rather it is the pool of a3a present in the actual target cell itself that inhibits incoming hiv-1 particles .
data from independent laboratories strongly support these conclusions for this role of a3a in target myeloid cells [ 6365 ] . within cells of the myeloid lineage
, a3a appears to be the critical suppressor , exerting its effect independently of its editing ability . in cd4 + t cells in the tissue culture model of infection ,
a3 g activity dominates , and its inhibitory function is exerted utilizing both editing - dependent and -independent mechanisms .
recent observations , however , have now suggested an unexpected and intricate antiviral role played by the a3 g expressed in target cells . expression of either a3a or a3 g activate the cellular dna damage response ( ddr ) . in the case of a3a ,
a g1/s - phase cell cycle arrest is also induced and its catalytic domain is implicated in the effect . while the relevance of these interesting observations in regard to hiv-1 infection is not immediately obvious ( the a3a experiments were performed in human osteosarcoma cells ) the role that the ddr response pathway plays in the innate immune response has only recently been explored and appreciated [ 68 , 69 ] .
experimental observations support the idea that triggering the ddr pathway acts as an alerting mechanism for the innate immune system [ 66 , 68 , 70 , 71 ] . in the emerging a3 g story
norman et al . examined expression of the critical natural killer ( nk ) cell - activating ligand , nkg2d - l , in hiv-1-infected primary cd4 + t cells .
they compared expression of nkg2d - l under conditions of wildtype hiv-1 infection and hiv-1vif infection and found a surprising discrepancy : the combination of vpr and a3 g in the hiv-1vif infections activated the ddr ultimately leading to the upregulation of both a3 g and nkg2d - l .
increased expression of nkg2d - l sensitized the hiv-1-infected cell to nk - mediated killing . in the presence of vif
the role of target cell - expressed a3 g was further verified using shrna 's targeting a3 g mrna ; loss of a3 g in an hiv-1vif setting resulted in diminished nk - killing and increased ( infected ) cell survival .
the authors suggest that , in a natural infection , the a3g - dependent sensitization of hiv-1-infected cells to nk - mediated killing is hindered by the loss of a3 g through vif - mediated degradation .
it bears mentioning that infection of murine primary b cells with the transforming retrovirus abelson murine leukemia virus ( ab - mulv ) also leads to the induction of activation - induced deaminase ( aid ) expression .
aid is a member of the larger apobec - aid family of cytidine deaminases ( this grouping includes the founding member , apobec1 , apobec2 , apobec3a - h and aid ) .
this induction of aid also results in the upregulation of an nkg2d ligand , rendering the infected cells susceptible to nk - mediated lysis .
the in vivo effect is the profound containment of ab - mulv replication and the ability of the host animals to restrict the virus and survive this pathogenic encounter .
this indirect effect of aid is also linked to the ddr - stimulated signaling pathways .
details on the mechanistic details of these antiviral functions have not yet been fully characterized . particularly intriguing
is whether the catalytic function of a3 g and/or aid is necessary for these effects , and , if so , how is this enzymatic capacity utilized . with the description of the involvement of the ddr ,
it is suspected that the signature cytidine deaminase modality would be important but confirmation of such speculation is warranted . based on these observations , therapeutic approaches that interfere with the process of vif - regulated degradation of a3 g
could potentially strengthen not only a potent intracellular defense , but also impact the ability of nk cells to attack infected cells .
as astounding as our progress has been in understanding the molecular and mechanistic details of a3 proteins and their interaction with hiv-1 , providing data for the in vivo relevance of a3 activity has been significantly more challenging .
experiments manipulating a3 g in the laboratory have supported the proposition that elevated expression levels of this restriction factor can and do alter wildtype hiv-1 infectivity ; clinical correlates of this in vitro observation have been more difficult to gather . with few exceptions ,
the clinical work to date has principally focused on a3 g and the effect its fluctuating expression levels and catalytic activity can have on hiv-1 infection and progression .
clinical analyses do not often lend themselves to large sample sets , and the confounding combinatorial effects of host genetics and environment strain efforts of reproducibility . with these openly acknowledged limitations
recognized , there remains an increasing amount of suggestive evidence that corroborates the idea that a3 g expression and/or activity can modulate natural hiv-1 infection [ 59 , 75 , 77 , 7981 ] ( table 1 ) . in infected individuals ,
hypermutated hiv-1 proviral genomes and elevated a3 g expression levels have been correlated with both lower viral loads and increased cd4 + t cells counts [ 75 , 8083 ] . in a relatively large study ,
land et al . noted the significant association between proviral hypermutation and increased peripheral blood cd4 + t cell count .
g expression was not directly quantified and the detected hypermutation was used as a surrogate for catalytic function of a3 g .
more direct analysis of a3 g expression in the setting of a natural hiv-1 infection has also yielded tantalizing hints of a3 g control . working with a small cohort of women ,
one group recently reported an interesting correlation between individuals expressing higher levels of a3 g before hiv-1 infection with the establishment of a lower viral set point after infection .
perhaps the most interesting cohorts in which to examine a3 g expression levels and the importance of these levels during viral infection in vivo are long - term nonprogressors ( ltnps ) , elite suppressors ( ess ) , and highly exposed seronegative ( hesn ) individuals . to date
, there has been no reporting of a3 g expression ( or activity ) as an explanation for the innate ability of an es to completely control the hiv-1 virus .
however , there has been an observation that elevated a3 g levels do correlate with higher cd4 + t cell counts and lower viremia within a group of identified ltnps , suggesting that , under certain conditions , overexpression of a3 g may be protective .
two independent studies , examining approximately 67 individuals who have been repeatedly exposed to hiv-1 , yet retain their seronegative status , have also presented evidence that elevated a3 g expression levels correlate with viral restriction [ 79 , 81 ] . amongst these two cohorts a variety of cell types were studied , including pbmcs , cd4 + t cells , cd8 + t cells , cd14 + monocytes , and cervical cells .
these cells were assayed for the level of a3 g expression primarily determined at the transcriptional level ; in a small number of instances , protein expression was also determined .
calculated levels of mrna and protein in hesn individuals were then compared to both hiv+ individuals and healthy controls and , in both experimental groups , hesn expressed statistically higher levels of a3 g expression .
one study carried the results further and was also able to show that pbmcs isolated from hesn individuals were able to more effectively limit a wildtype hiv-1 challenge .
interestingly , both pbmcs and cd14 + cells , isolated from these hesn individuals , appeared to exhibit higher responsiveness to ifn- treatment as measured by the induction of a3 g expression .
finally , a recent experiment utilizing the siv / macaque model for hiv-1 infection also suggests that investigating and understanding the consequences of increased a3 g ( and a3f , in this case ) expression levels may elucidate the protective role these defense proteins can play in vivo .
infected macaques were separated by clinical stage ( chronic versus aids stage of infection ) and compared to uninfected controls . in isolated
pbmcs , cd4 + t cells , and peripheral lymph nodes there was a demonstrated negative correlation between a3f / g mrna expression and viral loads .
in addition , the difference in a3f / g expression between control and infected animals was even more pronounced when individuals whose disease course mimicked that of hiv-1/ltnps were specifically compared .
one of the novel aspects of this reporting was the kinetic observation of the in vivo regulation of a3 g gene expression after siv challenge .
seven days after infection a3 g expression levels began to rise and this expression induction peaked on day 10 after infection .
the concomitant rise of a3 g levels , leading the rise of replicating virus levels , suggests that the struggle for control between this intracellular restriction factor and the invading pathogen occurs early , during acute infection .
this supports previous reports noting the hiv-1-induction of a3 g expression and the critical importance this early encounter may play on establishing viral set point [ 22 , 79 , 81 , 8486 ] . in spite of the meticulous analyses and important work accomplished , the current clinical understanding of how and whether a3 family members modulate hiv-1 infection is limited and somewhat unsatisfactory .
a consensus has not yet emerged and such agreement will likely require a more collaborative and coordinated effort , across cohorts and experimental approaches .
the details of designing such experiments are themselves still fraught with unknown parameters ; for instance , which cell types and/or tissues should be examined ? is an examination of proviral hypermutation or viral genome editing enough to serve as a marker for a3 g antiviral function ? is a measurement of a3 g mrna sufficient to draw conclusions regarding expression of the protein and resultant antiviral activity ?
at least two groups have noted a disconcerting disconnect between a3 g mrna and protein expression in pbmcs [ 60 , 79 ] .
do other a3 family members play distinct roles at discrete stages of viral infection ? in spite of this minefield of questions and the intrinsic limits placed on a data set as soon as a cohort of study is chosen , ventures into the clinical realm are paramount and it is only this data that can ultimately reveal the role of the a3 family in potentially containing hiv-1 infection .
in contrast to the undetermined impact human a3 proteins have in limiting natural hiv-1 infection , systematic and directed experiments in mice have conclusively shown that murine a3 ( ma3 ) is essential in containing and restricting several murine retroviruses : mmtv , a betaretrovirus ( mouse mammary tumor virus ) , f - mulv ( friend murine leukemia virus ) , a gammaretrovirus , as well as fv ( friend virus ) [ 8688 ] .
other murine gammaretroviruses , such as mlv ( murine leukemia virus ) , are resistant to ma3 restriction [ 8991 ] .
unlike the complex apobec3 locus in humans , which contains a tandem array of seven genes , the murine genome encodes a single apobec3 gene , ma3 [ 11 , 92 ] .
the knockout of ma3 was achieved quickly after the identification and cloning of a3 g .
while a preliminary examination of the mice was relatively uninteresting , detailed characterization of the response of these animals to specific viral challenge was both illuminating and exciting . in a series of informative and elegant in vivo experiments , it was shown that mmtv spreads more rapidly and is disseminated more extensively in mice lacking a functional ma3 gene as compared to wildtype mice .
the ma3 knockout mice exhibited higher initial viral loads and a shorter time to the development of mammary tumors .
it was interesting to note that the protection afforded by ma3 was not absolute ; ma3 blunted , but did not completely inhibit , mmtv infection , suggesting even partial protection has a significant role in in vivo pathogenesis .
the molecular mechanism of this ma3-dependent repression of infection remains unidentified , although it does appear that this antiviral function is exerted independently of any detectable hypermutation or viral genome editing . in this
setting ma3-mediated containment of mmtv bears a striking resemblance to a3a - dependent control of hiv-1 in myeloid cells : neither inhibition requires a detectable hypermutation function , although the block to viral infection traces to an early post - entry step , and antiviral function is exerted by protein expressed in target cells [ 22 , 86 ] . in the case of ma3 ,
antiviral function was a combinatorial effect of both virion - packaged and endogenously expressed protein . in terms of potentially harnessing the innate power of the a3 proteins ,
the most intriguing observation was the reporting that pre - treatment of wildtype mice with either lps or inf- upregulated ma3 expression in dendritic cells , the first cells infected during mmtv exposure .
this result speaks directly to some of the underlying concerns regarding the detrimental consequences of manipulating the expression of a3 g and certainly bolsters the hypothesis that increased expression of this protein could ameliorate restriction of hiv-1 infection . finally , it is interesting to note that in addition to reducing mmtv replication , virion - incorporated ma3 has also been shown to be able to markedly reduce the transmission of virus .
mmtv , as a number of other retroviruses , including hiv-1 , is transmitted vertically through breastfeeding . in an investigation examining the route of transmission , okeoma et al .
report that not only was ma3 mrna readily detectable in mammary epithelial tissue but that this packaged ma3 significantly decreased mmtv transmission . in an effort to extend these observations to hiv-1 infection
, this group examined expression of the a3 genes in primary human mammary tissue and found significant levels of both a3f and a3 g mrna .
whether this expression translates into protection from the vertical transmission of hiv-1 is not yet clear .
however , the trajectory of this study is interesting taken in the context of hiv-1 infection in which breastfeeding accounts for approximately 40% of vertical transmission .
interestingly , mice strains are differentially susceptible to fv , and a number of genes have been implicated in the resistance to this disease . both cell - mediated and humoral responses appear necessary for recovery and , naturally enough , the major histocompatibility complex ( mhc ) locus has been identified as important . however , an essential non - mhc gene , recovery from friend virus gene 3 ( rfv3 ) , has also been implicated .
mice strains resistant to fv ( e.g. , c57bl/6 ) , possess rfv3 resistance alleles , develop high concentrations of protective neutralizing antibodies , and recover from viremia .
mice strains susceptible to fv infection ( e.g. , balb / c ) fail to mount the protective humoral response , develop splenomegaly and erythroleukemia , and succumb to viral infection . in a revealing study ,
passive immunization of susceptible mice decreased mortality dramatically , suggesting that the rfv3 locus critically influences the production of the protective neutralizing antibodies .
it was to be 30 years before two groups simultaneously identified rfv3 as ma3 [ 87 , 88 ] . using a range of both in vivo and in vitro experiments they convincingly showed that ma3 expression was critical to the restriction of fv infection and resulted in the suppression of virus particle infectivity .
this inhibition to viral replication occurred after entry , but before integration , presumably affecting an early stage of fv infection ( potentially reverse transcription ) .
the description of the restrictive capacity of ma3 was reminiscent of the extensive data characterizing the a3 g anti - hiv-1 function .
it should also be noted that , in the fv system , ma3 function was exerted independently of any detectable cytidine deamination activity . while the observations supported the identity of ma3 as the suppressive factor , a consensus on what distinguished a resistant ma3 allele from a susceptible allele was less discernable .
preliminary data implicated the influence of ma3 polymorphisms on expression level , essentially suggesting the resistant ma3 alleles were more highly expressed [ 87 , 88 , 100 ] .
in addition , there was also suggestion of an important role for a coinherited b - cell - activating factor receptor ( baff - r ) allele .
recent work probing the resistant versus susceptible ma3 alleles has supported previous suggestion that an ma3 splice variant lacking exon 5 may be more potent than a full - length isoform [ 89 , 102 ] .
this latest work suggests that the ma3exon 5 variant is more efficiently translated and the overall combinatorial effect of elevated mrna levels and preferential translation of the ma3exon 5 account for significantly higher levels of ma3 protein capable of potently restricting fv infection .
a small number of genetic variants within the a3 family and their respective relationship to hiv-1 disease acquisition and progression have been described : the h186r variant of a3 g is associated with rapid progression in african american populations , the c40693 t variant of a3 g , as well as the homozygous loss of a3b , may be associated with increased infection susceptibility , and haplotype i of a3h may provide resistance to infection [ 59 , 73 , 74 , 78 ] . to date , a molecular understanding of how these variants modify ( or fail to modify ) hiv-1 disease is sorely lacking .
details of the defining characteristics of the resistant ma3 alleles are of significant interest upon contemplation that such differences , when identified , could be thoroughly dissected in a relevant in vivo setting , perhaps providing valuable insight into mechanistic detail .
such details may expand our understanding of the human versions of the a3 family and the critical polymorphisms .
what is also underscored in these reports is the importance of characterizing both expression levels and allelic differences of individual a3 genes within this family .
fluctuations of a3 g mrna levels , in which a3 g gene expression is upregulated , have been reported across the immature - to - mature differentiation transition in dendritic cells ( dcs ) [ 65 , 103 ] .
the ability of mature dc 's to resist hiv-1 infection is well documented , and this correlative observation is intriguing [ 104 , 105 ] . an observation reported in the mmtv system is also suggestive : the dc 's of mice stimulated with lps 24 hours prior to a viral challenge exhibited a modest ( 3 - 4-fold ) increase in ma3 mrna levels , but displayed a significantly increased restriction of mmtv .
finally , a recent paper examining a novel role for a3 g in the sensitization of infected cells to nk - mediated lysis suggests that small fluctuations in a3 g expression levels may have profound functional consequences .
these studies are interesting for their suggestion that modest elevations of ma3 and a3 g gene expression can lead to impressive increases in viral restriction .
when the identification and characterization of a3 g as a potent restriction factor emerged , the field raised numerous important questions and formulated strategies for capitalizing on this natural innate defense .
over several years , the identity of the entire a3 family of proteins as important innate restriction factors has been established .
the ability of a3 g to inhibit hiv-1vif infection has been analyzed by a significant number of laboratories , but the full complement of molecular details on how it exerts its antiviral function has not yet been gathered .
cytidine deamination undoubtedly occurs in the setting of a natural viral infection , but it is not entirely clear whether this enzymatic function is the only modality through which a3 g can obstruct hiv-1 in vivo .
in addition , the important , and likely critical contribution of additional a3 family members in vivo , remains largely uncharacterized , although recent work using a tissue - culture model would suggest that a collaborative effort amongst family members is essential .
utilization of both the mmtv / ma3 and fv / ma3 murine systems may be particularly useful .
alteration of the murine genome is relatively tractable and there is a single a3 gene in the rodent genome ; potentially , ma3 genetic variants may be assessed in this setting .
other outstanding questions include the determination of whether any of the a3 proteins require cofactors or post - translational modifications to function effectively . an important co - factor for apobec1 has been delineated and while there is a preliminary suggestion that a3f/3 g antiviral activity requires a co - factor , no specific proteins have been identified to date [ 106 , 107 ] .
manipulation of the vif : a3 g interaction is also a viable point of chemotherapeutic intervention . to date
only one compound specifically targeting vif and thereby liberating functional a3 g from vif regulation has been reported ; rapidly evolving technology may soon identify others .
a more comprehensive understanding of the interface involved in this viral and cellular protein association could identify new target sequences .
for instance , recent identification of the transcription factor cbf- as a member of the ubiquitin - ligase complex recruited by vif to degrade a3 g may prove interesting when considering novel drug targets . liberating a3 g from vif - mediated control has been shown to impact hiv-1 replication in vitro and suggests elevated levels of a3 g can have a significant impact on the kinetics of viral replication , but whether expression levels of a3 genes can be modulated in vivo remains to be determined . a better fundamental understanding of gene regulation and the important regulatory elements within this family is also essential . to date
only one of the promoters within the a3 family has been identified and characterized .
a more collaborative and concerted effort in the examination of various cohorts is more likely to reveal whether there exist meaningful associations between a3 genes and the ability to completely resist or partially restrict hiv-1 . in light of the recent data being produced in the murine systems , an examination of rapid progressors and various a3 genetic variants
additionally , data sets analyzing a3 g genetic variants , while relevant and useful , may have missed important information about other family members ; the recent findings involving a3a would suggest that this gene would also be important to examine in a number of cohorts .
these reports attribute an importance to a3 proteins that extends beyond the relatively simple arena of restriction factor .
g 's participation in marking cells for nk - mediated lysis would expand the reach of the a3 family into induced innate immunity , a series of cellular interactions important in bridging the innate and adaptive responses . further describing and characterizing
this observation will be important as it has potentially important implications for treatment during acute infection and vaccine design . in ten years
the field has exploded , from the recognition of a single potential restriction factor ( a3 g ) to an impressive understanding of a family of proteins that influence , modulate , and enhance the innate immune response . | ### Summary:
: since the identification of apobec3 g ( a3 g ) as a potent restriction factor of hiv-1 , a tremendous amount of effort has led to a broadened understanding of both a3 g and the apobec3 ( a3 ) family to which it belongs . in spite of the fine - tuned viral counterattack to a3 activity , in the form of the hiv-1 vif protein , enthusiasm for leveraging the vif : a3 g axis as a point of clinical intervention remains high . in an impressive explosion of information over the last decade ,
additional a3 family members have been identified as antiviral proteins , mechanistic details of the restrictive capacity of these proteins have been elucidated , structure - function studies have revealed important molecular details of the vif : a3 g interaction , and clinical cohorts have been scrutinized for correlations between a3 expression and function and viral pathogenesis . in the last year , novel and unexpected findings regarding the role of a3 g in immunity have refocused efforts on exploring the potential of harnessing the natural power of this immune defense .
these most recent reports allude to functions of the a3 proteins that extend beyond their well - characterized designation as restriction factors .
the emerging story implicates the a3 family as not only defense proteins , but also as participants in the broader innate immune response . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: multiple sclerosis is a chronic progressive disease that results in a number of symptoms including weakness , spasticity , tremor , ataxia , sensory disturbance , and balance disruption .
it is suggested that within 1525 years of diagnosis approximately 50% of people with ms ( pwms ) will require the use of a walking aid [ 2 , 3 ] .
mobility loss is significantly associated with loss of employment and with increasing assistance with activities of daily living ( adls ) and pwms identify the continued loss of mobility as one of their greatest concerns for their future .
loss of mobility and its resultant impact on every day activities are reflected by the increasing cost of care with greater disability .
there is an ever - expanding body of the literature to suggest the positive effect of exercise and physiotherapy interventions .
those who use walking aids have been included in several studies of physiotherapy interventions [ 710 ] , progressive resistance training ( prt ) [ 11 , 12 ] , aerobic exercise [ 1315 ] , and a combination of the above , and generally the studies have had positive outcomes .
however , as the results of those who use walking aids have not been analysed separately , it is difficult to evaluate the effect of the interventions for this specific population
. given the combinations and severity of their symptoms and resulting activity limitations , it is possible that they will respond differently to those with minimal disability .
few studies have specifically focused on those with significant walking limitations that require support for gait ( edss 6 - 7 ) .
. found that treadmill training with body weight support resulted in significant improvements in quality of life , with large effect sizes for fatigue .
a survey of current practice in physiotherapy found that most people with ms who use walking aids are treated at home or in community or primary care settings .
two studies were found that specifically evaluated interventions at home for people with ms who used walking aids .
a pilot study of fes cycling at home found trends for improvement in strength , walking speed , and endurance and in those muscles that were treated with electrical stimulation but the results need to be confirmed in a larger sample .
in contrast miller et al . found no significant effect of home - based therapy , which consisted of twice weekly physiotherapy for eight weeks .
their small sample size may have influenced findings , which found some increases in impact of ms and strength for the intervention group .
there is therefore a need for studies specifically exploring the responses of people with ms who use bilateral support for gait to interventions provided in the community . in ireland
the ms society provides physiotherapy and yoga interventions in community settings and commissioned this study to investigate their effectiveness .
the objective of this study was to evaluate the effectiveness of yoga and physiotherapy interventions delivered in community settings for people with significant disability due to ms who use bilateral aids for gait .
the aim of this study was to compare the effects of a ten - week programme of group physiotherapy , individual physiotherapy , and yoga in the community to a control group who were asked not to change their exercise habits . given the complex interactions of symptoms of this group we hypothesised that individual physiotherapy intervention would have more positive outcomes than group intervention and that physiotherapy interventions would have a greater outcome than that due to yoga .
we also hypothesised that treatment would either prevent deterioration or bring about improvement compared to the control group .
this paper concerns the results for strand b or those people with ms who score 3 or 4 on the mobility section of the guys neurological disability rating scale .
this indicates that they use bilateral assistance for gait and may use a wheelchair for longer distances .
the study received ethical approval from the relevant committees in the 10 regions where the study took place .
people who had their ms diagnosis confirmed by a consultant physician were included in the study .
people with ms were excluded from the study if they had experienced an exacerbation of symptoms due to relapse or initiated steroid treatment in the last 12 weeks , were pregnant at the time of referral , or were under 18 years of age .
referral was made to the regional offices of ms ireland by the persons themselves , their physiotherapist , general practitioner , consultant , or nurse .
participants were screened for eligibility , sent the relevant information leaflet , and gave informed consent . once consent for 8 people in that geographical region
was obtained , they were block randomised to one of the three interventions or to the control group by the national coordinator in ms ireland .
the randomisation sequence was generated by removing strips of paper from an envelope and was concealed from all involved in the study until the point of randomisation of that group .
it should be noted that a number of blocks of participants were not treated as randomised .
groups allocated to yoga and to the control group lobbied to receive physiotherapy and were subsequently randomised to either group or individual physiotherapy .
assessments were carried out at baseline ( week 1 ) and postintervention ( week 12 ) by a blinded assessor .
the following outcome measures were used : berg balance scale ( bbs ) six - minute walk test ( 6mwt ) , multiple sclerosis impact scale 29 version 2 ( msis ) , and modified fatigue impact scale ( mfis ) .
the bbs is a clinical scale that evaluates balance in sitting and standing and rates performance from 0 ( can not perform ) to 4 ( normal performance ) .
the bbs was found to have a good concurrent validity and a cut - off score of 44 ( out of 56 ) was established as a criterion to identify pwms who have high risk of falls .
it was found to have high test - retest and interrater reliability , both having intraclass correlation coefficients ( iccs ) of 0.96 . in the 6mwt ,
the participants were asked to walk for a period of six minutes and the distance walked was recorded .
. found that the 6mwt is highly reliable in people with mild - to - moderate ms ( edss 26.5 ) and marrie and goldman validated the 6mwt as an outcome measure for pwms .
subjects were instructed to walk as quickly and safely as possible as recommended by fry and pfalzer .
the msis-29v2 is a patient - reported outcome measure that assesses the physical and psychological impact of ms .
it consists of 29 questions and is scored from 0 to 100 with higher scores indicating a greater impact of ms .
it was developed and evaluated using robust psychometric techniques and is valid , reliable , and sensitive to change in pwms [ 2729 ] .
the physiotherapy group intervention was a self - paced circuit style class of exercises that targeted strength and balance with the aim of increasing balance and mobility .
the exercises were adapted from the falls prevention literature where similar programmes have been seen to improve , balance , and reduce the number of falls in an elderly population and in people with ms .
when a participant was able to perform 12 repetitions of an exercise safely , it was progressed up to 3 sets of 12 repetitions .
the progression was dependent on the ability of the participant and their safety while performing the exercises .
the participants allocated to individual physiotherapy received individual treatment depending on the problem list and goals established by the chartered physiotherapist who was treating them .
all yoga instructors were members of the yoga federation of ireland and kept a log of the content of each yoga class .
the distribution of the data was analysed for normality using histograms , quantile - quantile plots , and the shapiro wilk statistic .
baseline differences between groups were assessed using one - way anova ( normally distributed data ) , kruskal wallis ( nonnormally distributed data ) , and chi square test for independence ( categorical data ) .
repeated measures anova was performed for the physical component of the msis-29v2 , the mfis , and the bbs due to the normal distribution of the data .
post hoc analysis was conducted using paired - samples t - tests for within - group changes and independent t - tests on the change scores for between - group differences . for the psychological component of the msis-29v2 and the 6mwt
the normality tests yielded p values of < 0.05 and the histograms revealed skewed data ; therefore , the assumptions of parametric testing were not met .
wilcoxon signed rank tests were used to analyse the differences within groups and the kruskal wallis and mann whitney u tests were used to analyse the differences in change scores between groups .
the reasons for attrition and the rate of dropouts were similar across the groups ( figure 1 ) .
the median number of sessions attended was 8 ( semi - interquartile range 1.5 ) , 9 ( 1 ) , and 8 ( 2.25 ) , for group physiotherapy individual physiotherapy and yoga , respectively . there was no significant difference between the three intervention groups for the number of sessions attended , p = 0.139 using the kruskal - wallis test .
analysis of the documentation of the content of the interventions revealed that group physiotherapy was performed as prescribed .
for individual physiotherapy , three out of the four physiotherapists delivered strength and balance exercises that were similar to those prescribed for the group physiotherapy in addition to other treatments specific to the individuals ' problems .
additional components included pacing techniques , specific lower back exercises , walking , stretching , and bridging exercises .
relaxation , meditation , breathing techniques , and stretching were common to all three classes .
one of the three classes included squatting , which was one of the prescribed exercises for the group physiotherapy intervention .
other components that made up the yoga classes included maintaining different static poses , for example , the mountain pose , the cat pose and the tailor pose ( 2 classes ) , and self - massage ( 1 class ) .
the descriptive statistics and post hoc tests for all outcome measures are presented in table 3 .
repeated measures anova showed a significant time effect for the physical component of the msis-29v2 ( f = 7.993 , p = 0.006 ) and the mfis ( f = 8.695 , p = 0.004 ) .
the group time interaction was significant for the bbs ( f = 4.391 , p = 0.006 ) .
all interventions showed a statistically significant improvement from week 1 to week 12 on the bbs which was greater than the control group .
post hoc analysis using an independent t - test revealed there was no significant difference between group and one to one physiotherapy on the bbs ( p = 0.242 ) . due to the small numbers in the yoga group , post
nonparametric analysis revealed a significant change over time on the 6mwt for one - to - one physiotherapy ( p = 0.001 ) and on the msis-29v2 psychological component for group physiotherapy ( p = 0.005 ) .
the kruskal wallis test showed that there was no statistically significant difference between groups for the psychological component of the msis-29v2 or the 6mwt .
the control group showed a similar magnitude of change to the physiotherapy intervention groups on the self - report outcome measures .
this is only one of a few trials that specifically address the effects of interventions in the community for those with significant mobility limitations who use bilateral support for gait .
these data provide preliminary evidence of the effectiveness on balance of group and individual physiotherapy interventions delivered pragmatically in community settings .
the only evidence to support our hypotheses that treatment improves outcomes is from the bbs results .
the worsening of scores in the control group is not unexpected in this group who present primarily with progressive ms .
the magnitude of the mean improvements in our study was similar to those of cattaneo et al . who found an improvement of 4.6 as a result of balance exercises based on motor strategies
however , this degree of change is less than the 6.5 value for the minimal detectable change for people with ms
. it should be noted , however , that our participants started with far lower bbs scores ( 2230 ) than those evaluated in previous studies ( > 40 ) ; therefore , this degree of change may be clinically relevant to this degree of balance deficit . interestingly
this improvement in balance does translate to a reduction in both falls risk and number of falls . because of the small sample sizes confirmation of the effect of yoga
is required and the effect of physiotherapy interventions needs further comparison to a larger , matched , and control group .
we hypothesised that individual physiotherapy would be more effective than the group interventions . while individual physiotherapy was tailored to the individual goals and impairments of the participants , the group intervention aimed to improve balance and mobility and was tailored only to ability level for those exercises .
post hoc analysis of the individual and group physiotherapy treatments suggests that there were no differences on the bbs between groups . as this trial
was not planned as a noninferiority study , further comparison of group and individual physiotherapy for this population is warranted using a range of outcomes . the main problem reported by the participants was walking / mobility limitations .
the percentage improvements in 6mwt were 20.1% for group and 19.4% for individual physiotherapy , while the yoga group worsened by 35% .
the high variability in the 6mwt data at baseline and in response to treatment may have led to nonsignificant findings despite relatively large median and % changes .
the lack of deterioration in the control group is conflicting with the bbs data and suggests that further evaluation of this measure with larger groups with similar baseline characteristics is required .
there is conflicting evidence around the efficacy of yoga for mobility outcomes in pwms in people with minimal gait impairment .
ahmadi et al . evaluated the effect of yoga in those with less gait limitations and found small but statistically significant effects on 2mwt and 10mwt .
the other strand of this study ( those who use at most a stick to walk ) did not have statistically significant improvements in 6mwt following yoga
. the lack of improvement in walking endurance in both arms of this study may reflect the specificity principles of exercise ; they practiced static poses and not the specific elements and task of walking .
the finding that participants randomised to the yoga and control groups lobbied to receive immediate physiotherapy interventions suggests that this cohort perceive a need or preference for physiotherapy .
hence , these data provide some new information about the treatment preferences of those people with ms who require bilateral support for gait .
patient preference may have contributed to the deterioration in self - reported measures in the yoga group , which conflicts with the objective measure of balance .
a review of studies that used a randomised preference design found that patients who received their preference had significantly greater improvements .
when patients do not receive their preferred treatment and this may explain the deterioration in the self - reported measures in the yoga group .
this resulted in detection bias as the groups were not similar at baseline . at baseline ,
however , they were similar for all clinical measures with the exception of the mfis score for the yoga group .
the score of 30.4 on the mfis for the yoga group is lower than the cutoff of 38 for clinically meaningful fatigue and may indicate that they were not significantly fatigued to start with .
an additional element of detection bias is present as it was not possible to blind the participants to their group allocation .
the contact with an assessor on two occasions may also have led to elements of performance bias . while not statistically significant the control group improved on the self - reported outcome measures to the same magnitude as the treatment groups .
this suggests that there may be a placebo effect of contact on the impact of ms and impact of fatigue .
completer analysis is presented as it is inappropriate to impute values for intention to treat analysis when more than 20% of the data is missing .
given the variable nature of the disease it was also felt that other forms of intention to treat analysis were not appropriate as the rate of deterioration or improvement between participants is variable and unpredictable .
these data provide preliminary evidence that 10-week interventions consisting of balance and strengthening exercises improve balance ; however , given the methodological limitations of the trial , confirmation of these findings with a larger , matched control group is required .
post hoc analysis of the data suggests that the response to group and individual physiotherapy for balance is similar but this also requires confirmation in a trial that aims to compare this effect directly .
people with ms who use bilateral support for gait indicated their preference for physiotherapy interventions over waiting three months for treatment or participating in yoga .
patient preference and the placebo effect of contact may have influenced the patient - reported outcome measures . | ### Summary:
: background .
mobility limitations are a key feature of ms and 25% will require the use of a walking aid 15 years after diagnosis .
few studies have specifically evaluated the effectiveness of physiotherapy and exercise interventions delivered in the community for those with significant disability .
methods .
an assessor blind , block randomised , and controlled study recruited participants who required bilateral assistance for gait and who occasionally used wheelchairs for longer distances .
they were randomised to 10 weeks of group physiotherapy ( balance and strengthening exercises ) , individual physiotherapy , yoga group , or a control group .
results .
repeated measures anova found significant time effects for physical component of msis-29v2 ( f = 7.993 , p = 0.006 ) and mfis ( f = 8.695 , p = 0.004 ) .
the group time interaction was significant for the bbs ( f = 4.391 , p = 0.006 ) .
post hoc analysis revealed no difference between group and individual physiotherapy for bbs .
there was no significant difference between groups but the 6mwt improved for individual physiotherapy ( p = 0.001 ) and msis-29v2 psychological score for group physiotherapy ( p = 0.005 ) .
discussion .
this study found that balance and strengthening exercises , delivered in the community to those with significant mobility limitations , improve balance .
the effect on walking endurance and patient - reported outcomes are unclear and warrants further investigation with a larger control group with similar baseline characteristics to the intervention groups . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: it
is well known that adoption of inadequate postures at work , repetition of computer tasks
such as typing and use of a computer mouse , and sitting for long periods of time lead to
symptoms in the neck , upper limbs , eyes , thoracic spine and low back1 , 2 . in a study carried
out in brazil with bank workers ,
the head position ( bending of the neck ) , shoulder abduction angle ,
and use of a computer mouse are important factors related to musculoskeletal disorders5 , 6 ,
mainly if a person uses a computer device for a great number of hours per day .
another important issue that has been discussed in recent years is psychosocial health at
work6 , 8 ,
9 .
job satisfaction , motivation , and
quality of life ( qol ) are key subjects to achieve high performance in work activities .
a
study carried out in portugal8 found that
26.4% and 25.8% of university workers were dissatisfied and unmotivated , respectively , both
of which are associated with absenteeism and can lead to trouble in the work environment .
hagberg et al . stated that when musculoskeletal discomfort affects qol , it needs to be
identified as soon as possible so the appropriate treatment can be applied9 .
considering that prolonged sitting in fixed positions increases biomechanical stress on the
back , neck , and upper limbs10 and that
psychosocial factors are associated with pain6 , evaluation of specific postures adopted during work activities as
well as workers qol and motivation is important in order to better understand the origin of
some symptoms .
there are already some studies discussing this issue1,2,3 , 5 , 6 , 10 , 11 , but few of them are from brazil3 , 11 . furthermore ,
none of the
previous studies included both biomechanical and psychosocial factors in their analyses .
therefore , the aim of the present study was to verify the relationship among work - related
characteristics , psychosocial factors , health - related quality of life , and pain among
workers from the a university center in rio de janeiro , brazil .
this cross - sectional study evaluated 15 office workers who use a computer at work from a
university center in rio de janeiro , brazil .
the inclusion criteria were as follows : adults
aged 1860 years old , right handed , at least six months working in the institution in their
current position , and use of computers to do their job tasks for at least four hours per
day .
those presenting any
implantable electronic or metallic device , such as a pacemaker , and pregnant women were
excluded from body composition analysis .
measurements were mainly performed at the laboratory of human movement analysis
( postgraduate program of rehabilitation sciences - unisuam ) and at the participants
workplace .
laboratory evaluations included : a ) anthropometric and bioelectrical impedance
measurements to verify body composition and b ) photogrammetry to assess postural alignment .
workplace evaluations comprised measurements of desks , chairs , computer screens , mice and
keyboards , and body segment lengths .
distances , heights , lengths , and angles were measured
while volunteers were operating these devices .
the two set of evaluations ( laboratory and
workplace ) were carried out on different days . on the first day of evaluation , subjects
received some questionnaires ( described below ) to answer at home , and these were to be
returned on the second day of evaluation .
when the laboratory evaluations were scheduled ,
the following recommendations were informed to each participant : 1 ) do not consume alcohol
or exercise within 24 hours prior to the test ; 2 ) do not consume caffeine or food for 4
hours prior to the test ; 3 ) drink 2 to 4 glasses of water within 2 hours prior to the test ;
4 ) use the bathroom use within 30 minutes prior to assessment , and 5 ) wear minimal clothing
without any metallic parts for photogrammetry and body composition analysis .
the protocol was approved by the institutional ethics committee ( caae:0009.0.307.000 - 11 ) ,
and written informed consent was obtained from all participants before participation in this
study . the weights and heights of the subjects were measured using an analog balance scale
( rounded to the nearest 0.1 kg ) with a stadiometer applied ( rounded to the nearest 0.005 m )
( r110 , welmy , so paulo , brazil ) . body mass index ( bmi ) was calculated following
the standard method ( bmi = weight / height2)12 .
waist circumference was measured at the
narrowest point between the lower costal border and the iliac crest13 with a flexible steel tape ( terrazul , so
paulo , brazil ; 0.1 cm ) .
body composition analysis was performed using a bioelectrical impedance analyzer ( bia 310e ,
biodynamics , shoreline , wa , usa ) .
the test current used was 800 a at 50 khz ,
well below the association for the advancement of medical instrumentation s standard for
safe current limi . the tetrapolar resistance and
reactance measurements were collected in
a standardized manner : the subjects were asked to rest for five minutes prior to the exam on
an examination table .
feet and
hands were at least 30 and 15 cm apart , respectively .
two electrodes were applied to the
dorsal surface of the right hand , and two were placed on the dorsal surface of the right
foot .
resistance and reactance provided by the analyzer were used for fat free mass ( kg )
estimation .
other analyzed variables were fat mass ( kg ) and fat percentage ( % ) . the equation
selected to predict fat free mass was previously validated in a study of 2094-year - old
adults14 and was as follows ffm =
4.104 + 0.518 ( h / r ) + 0.231 ( bw ) + 0.130 ( xc ) + 4.229 ( g ) , where ffm = fat free
mass ( kg ) , h = height ( cm ) , r = resistance ( ) , bw = body weight ( kg ) , xc = reactance ( ) ,
and g = gender ( 0 for females and 1 for males ) .
anterior ( av ) and right view ( rv ) pictures were taken with a camera ( dsc - h7 , 8.1
megapixels , sony , japan ) placed on a tripod at one meter above the ground and three meters
from the participant .
a black background and a plumb line marked with two styrofoam balls
( placed at a distance of 100 cm ) were used to ensure better definition and to calibrate the
images while analyzing them in the postural assessment software ( pas / sapo version 0.68 ,
2007 , so paulo , brazil)15 .
the following
anatomical landmarks were marked with styrofoam balls ( 15 mm diameter ) : c7 spinous process ,
right and left tragus , acromions , anterior superior iliac spines ( asis ) , posterior superior
iliac spines ( psis ) , greater trochanters , and malleoli .
the analyzed angles in the av were
the head horizontal alignment ( angle formed by a tragus line and horizontal line ) and
acromion - asis angle ( angle formed by an acromion line and asis line ) .
for both angles , a
positive value indicates inclination to the right , and a negative value indicates indication
to the left . in the rv ,
the following angles were analyzed : head protrusion ( angle formed by
a c7-tragus line and horizontal line ) , pelvic tilt ( angle formed by an asis - psis line and
horizontal line ) , and hip angle ( angle formed by an acromion - greater trochanter line and
greater trochanter - malleolus line ) .
analyses were done offline , and the pas / sapo software
can be considered a useful and reliable tool for measuring body posture15 , 16 .
the following variables were assessed with a measuring tape ( western pro 5 m 19 mm ,
western , brazil ) : desk and chair heights , lengths , and widths ; computer screen height ( from
the floor to the top of the screen ) ; thigh length ( from the knee joint line until the
buttocks ) ; leg height when sitting ( from the knee joint line until the floor ) ; and eye
height when sitting ( from the eye lateral mark until the floor ) . to measure the length of
the back without support , a flexible steel tape ( terrazul , so paulo , brazil )
was used .
a goniometer ( carci , so paulo , brazil ) with values rounded to nearest
2 was used to measure the shoulder abduction angle in the frontal plane while the subjects
used a computer mouse ( fulcrum at the acromion , one arm in the direction of the floor and
the other arm in the direction of the olecranon ) , the elbow angle in the sagittal plane
while the subjects were typing ( fulcrum at the lateral epicondyle of the elbow , one arm in
the direction of the styloid process of the radius and the other arm in the direction of the
humerus ) , and the knee angle while the subjects were sitting in the sagittal plane ( fulcrum
at the knee joint line , one arm in the direction of the greater trochanter and the other arm
in the direction of the malleolus ) .
all variables were measured on the right side . whether
or not the subjects were using their chair backs
complaints of pain were assessed using the validated portuguese version of the nordic
musculoskeletal questionnaire17 and the
multidimensional pain evaluation scale18 .
the participants were asked to indicate the regions in which they experienced pain within
the last year .
body regions were analyzed separately and were also grouped as proposed by
hakala et al.1 : a ) neck or shoulders ; b )
hands , fingers , and wrists ; c ) lower back ; d ) head ; and e ) eyes .
when a complaint was
reported , the intensity was evaluated using the visual analog scale ( varying from 0 , no
pain , to 10 , the most intense pain ) .
the medical outcomes study 36-item short - form health survey ( sf-36 ) was used to assess the
health - related quality of life ( qol ) of the sample using its translated and validated
portuguese version19 .
the sf-36 is a
generic qol assessment instrument composed of 36 items , divided into eight dimensions :
physical function ( pf ) , general health ( gh ) , vitality ( vt ) , mental health ( mh ) , social
function ( sf ) , role - emotional ( re ) , role - physical ( rp ) , and bodily pain ( bp ) .
each scale ranges from 0 to 100 points , with 100 points
representing the best satisfaction with qol , while 0 points represents the highest
dissatisfaction with qol20 , 21 . to evaluate subjects motivation at work ,
the scores were calculated for four subscales : job organization , performance ,
execution / power , and involvement , and ranged from 0 to 100% .
the participants also answered some questions about their work - related behaviors , like the
number of short breaks ( of at least five minutes ) that they take during the work day ; the
number of hours spent in a seated position ; the number of working hours in a workday ; and
the length of time , in years , that the subject had worked at the institution .
there were
also some questions about lifestyle issues , like sleep position , hours of sleep , and
exercise practices .
the sample was analyzed as a whole or stratified for presence of short breaks ( no rest
break group , nrbg , and short rest breaks group , srbg ) , and complaints of pain complaint at
each body region ( complaint group and no complaint group ) .
this stratification was performed
in order to identify a possible association between the use of rest breaks throughout the
workday and all the work - related characteristics assessed in this research .
for numeric variables ,
values are expressed as medians ( interquartile range ) ; comparison between groups were
performed by mann - whitney test , and the spearman correlation test was applied to investigate
associations between the assessed variables .
the categorical variables were presented as
absolute frequencies ( relative frequencies ) , and to verify the differences between the
subgroups created by the factors short rest breaks , pain complaint , and use of a chair back ,
fisher s test was chosen . statistical package for the social sciences ( spss ) 13.0 for
windows ( spss inc . ,
chicago , il , usa ) was used for all statistical analysis , and
significance was assigned whenever the p value was less than 0.05 .
characteristics of the studied samplevariableall subjects ( n = 15)age ( years)32.0 ( 26.834.5)males ( n ( % ) ) 10 ( 66.7)weight ( kg)72.2 ( 68.886.3)fat mass ( % ) 36.2 ( 27.739.9)seated position at work ( hours / day)9.0 ( 6.310.0)workday ( hours / day)10.0 ( 9.010.0)working years2.9 ( 1.44.3)head alignment ( )0.5 ( 2.12.8)acromions - asis ( )0.55 ( 1.71.2)head protrusion ( )40.8 ( 38.347.3)pelvic tilt ( )14.4 ( 17.96.3)hip angle ( )8.1 ( 12.71.5)computer screen height ( cm)106.6 ( 102.2116.3)eye height when sitting ( cm)120.0 ( 113.3123.0)leg height when sitting ( cm)52.0 ( 50.056.5)thigh length ( cm)56.0 ( 54.058.0)back without support ( cm)26.0 ( 17.335.8)shoulder abduction mouse ( )58 ( 4563)typing elbow angle ( )128 ( 117130)knee angle when sitting ( )96 ( 76113)data are presented as medians ( 1st quartile3rd quartile ) for numeric values and
absolute frequencies ( relative frequencies ) for categorical values .
n = number
( absolute frequency ) . ) . for pain complaint analysis ,
two participants were excluded because they did
not return the questionnaire about body regions of pain complaint . every worker enrolled in
the study suffered from pain in at least one body region .
srbg and nrbg were well matched
for age , weight , body composition , and other work - related behaviors ( table 2table 2 .
anthropometric and work - related variables for all subjects and separately for
srbg and nrbgall subjects ( n = 15)srbg ( n = 6)nrbg ( n = 9)age ( years)32.0 ( 26.834.5)34.5 ( 32.537.3)29.0 ( 26.032.0)males ( n ( % ) ) 10 ( 66.7)5 ( 83.3)5 ( 55.6)weight ( kg)72.2 ( 68.886.3)73.3 ( 59.994.7)71.0 ( 68.685.4)bmi ( kg / m)26.3 ( 21.229.7)26.9 ( 22.431.1)25.6 ( 20.828.5)waist ( cm)82.0 ( 76.198.4)89.0 ( 72.199.7)80.8 ( 75.689.1)fat mass ( kg)24.2 ( 19.134.1)22.5 ( 18.435.6)25.8 ( 21.536.3)fat mass ( % ) 36.2 ( 27.739.9)35.1 ( 29.137.6)39.3 ( 26.245.0)fat free mass ( kg)50.1 ( 41.257.8)50.9 ( 41.459.0)43.6 ( 40.556.2)seated position at work ( hours / day)9.0 ( 6.310.0)7.5 ( 2.311.3)9.0 ( 7.310.0)workday ( hours / day)10.0 ( 9.010.0)9.5 ( 9.010.0)10.0 ( 9.510.0)working years2.9 ( 1.44.3)3.0 ( 1.25.0)2.8 ( 1.54.5)data are presented as medians ( 1st quartile3rd quartile ) for numeric values and
absolute frequencies ( relative frequencies ) for categorical values .
n = number
( absolute frequency ) ; srbg = short rest breaks group ; nrbg = no rest break group ; *
p < 0.05 , comparing srbg and nrbg ( mann - whitney test ) ) . nevertheless , the number of body regions with pain complaints was greater
for nrbg ( mode = 3 ) than for srbg ( mode = 1 ) .
data are presented as medians ( 1st quartile3rd quartile ) for numeric values and
absolute frequencies ( relative frequencies ) for categorical values .
data are presented as medians ( 1st quartile3rd quartile ) for numeric values and
absolute frequencies ( relative frequencies ) for categorical values .
n = number
( absolute frequency ) ; srbg = short rest breaks group ; nrbg = no rest break group ; *
p < 0.05 , comparing srbg and nrbg ( mann - whitney test ) when comparing the groups with respect to complaints of pain in each body region , the neck
and low back presented higher prevalences in the nrbg ( table 3table 3 . prevalence of pain complaints in each body region in the srbg and nrbg ( n
( % ) ) body regionall subjects ( n = 13)srbg ( n = 5)nrbg ( n = 8)low back10 ( 76.9)2 ( 40.0)8 ( 100.0)*neck5 ( 38.5)0 ( 0.0)5 ( 62.5)*thoracic back4 ( 30.8)2 ( 40.0)2 ( 25.0)wrist3 ( 23.1)1 ( 20.0)2 ( 25.0)knee2 ( 15.4)1 ( 20.0)1 ( 12.5)head1 ( 7.7)0 ( 0.0)1 ( 12.5)shoulder1 ( 7.7)0 ( 0.0)1 ( 12.5)arm1 ( 7.7)0 ( 0.0)1 ( 12.5)hand1 ( 7.7)1 ( 20.0)0 ( 0.0)hip1 ( 7.7)0 ( 0.0)1 ( 12.5)foot1 ( 7.7)0 ( 0.0)1 ( 12.5)ankle0 ( 0.0)0 ( 0.0)0 ( 0.0)data are presented as absolute frequencies ( relative frequencies ) . * p < 0.05
comparing the srbg and nrbg ( test ) .
srbg = short rest breaks group ; nrbg
= no rest break group ) . furthermore , when grouping body regions , the location neck or shoulders
also showed a higher number of subjects reporting pain symptoms in the nrbg ( 62.5%
vs. 0.0% ) .
the location hands , fingers , and wrists did not show any
difference ( 25% for the nrbg vs. 20% for the srbg ) .
considering the whole sample , the low back was the more
prevalent region of complaint , followed by the neck , thoracic back , and wrist ( table 3 ) . considering only the upper limbs and neck ,
the prevalence of pain was
data are presented as absolute frequencies ( relative frequencies ) . * p < 0.05
comparing the srbg and nrbg ( test ) . srbg = short rest breaks group ; nrbg
= no rest break group subjects with neck complaints had worse scores for the sf-36 bodily pain domain ( table 4table 4 .
quality of life scores for the neck complaint group and no neck complaint
groupvariableall subjectscomplaintno complaint(n=13)(n=5)(n=8)bp domain72.0 ( 41.084.0)31.0 ( 11.062.5)73.0 ( 49.596.0)*pf domain90.0 ( 75.095.0)85.0 ( 55.092.5)90.0 ( 68.898.8)rp domain100.0 ( 75.0100.0)100.0 ( 25.0100.0)87.5 ( 75.0100.0)gh domain72.0 ( 55.087.0)67.0 ( 48.569.5)87.0 ( 63.395.8)vt domain55.0 ( 40.060.0)50.0 ( 45.082.5)57.5 ( 51.370.0)sf domain75.0 ( 50.087.5)87.5 ( 56.393.8)75.0 ( 65.696.9)re domain66.7 ( 33.3100.0)66.7 ( 33.3100.0)83.3 ( 66.7100.0)mh domain72.0 ( 60.080.0)68.0 ( 62.082.0)76.0 ( 69.083.0)data are presented as medians ( interquartile ranges ) . * p < 0.05 comparing the
complaint and no complaint groups ( mann - whitney test ) .
bp = bodily pain ; pf = physical
function ; rp = role - physical ; gh = general health ; vt = vitality ; sf = social
function ; re = role - emotional ; mh = mental health ) , smaller values for the head protrusion angle ( greater protrusion in the side
view ) ( table 5table 5 .
posture alignment and workplace measurements for the neck complaint group and no
neck complaint groupvariableall subjects ( n=13)complaint ( n=5)no complaint ( n=8)workplace measurementsseated position ( hours)9.0 ( 6.310.0)9.0 ( 6.510.0)8.0 ( 3.511.0)back without support ( cm)26.0 ( 17.335.8)49.0 ( 20.566.3)21.5 ( 15.329.0)typing elbow angle ( )128 ( 117130)127 ( 97130)130 ( 110141)eye - screen hdiff ( cm)10.5 ( 0.820.2)14.9 ( 9.928.1)8.7 ( 2.921.8)posture alignment orthostatic position
( angles)head protrusion ( )40.8 ( 38.347.3)38.2 ( 35.438.7)*46.1 ( 39.547.7)head alignment ( )0.5 ( 2.12.8)2.3 ( 3.14.7)1.3 ( 2.11.6)acromions - asis ( )0.6 ( 1.71.2)2.0 ( 2.71.5)0.2 ( 1.41.2)data are presented as medians ( interquartile ranges ) . * p < 0.05 comparing the
complaint and no complaint groups ( mann - whitney test ) .
asis = anterior superior iliac
spines ; hdiff = height difference . ) , and were younger ( median age , interquartile range : 27.5 , 21.531.3 vs. 33.5 ,
31.340.5 ; p = 0.04 ) than those with no neck complaints .
the participants with wrist
complaints had higher values for shoulder angle while using a computer mouse median angle ,
interquartile range : 64 , 6076 vs. 52 , 4860 ; p = 0.03 ) .
* p < 0.05 comparing the
complaint and no complaint groups ( mann - whitney test ) .
bp = bodily pain ; pf = physical
function ; rp = role - physical ; gh = general health ; vt = vitality ; sf = social
function ; re = role - emotional ; mh = mental health data are presented as medians ( interquartile ranges ) .
* p < 0.05 comparing the
complaint and no complaint groups ( mann - whitney test ) .
the investigation of the associations among the number of body regions with complaints of
pain and the variables concerning body composition , posture alignment , quality of life , and
work - related motivation scores showed significant correlations only for fat mass percentage
( r=0.582 ; p = 0.037 ) and head protrusion angle in the right view ( 0.728 ; p=0.003 ) .
the sleep positions of the studied subjects were prone position ( n = 10 ; 66.7% ) and lateral
decubitus position ( n=5 ; 33.3% ) .
furthermore , there was no
association between sleep position and the presence of pain in any studied body region .
the factor use of a chair back was associated with the prevalence of thoracic pain .
the
subjects who were not using a chair back when the professionals visited their workplace had
a statistically higher prevalence of thoracic pain ( 75% ) than those who were using a chair
back ( 0% ) ( p = 0.03 ) .
no other body region presented an association between this factor and
prevalence of pain complaint .
the work - related motivation scores for the whole sample were 80.0 ( 77.194.3 ) for the job
organization subscale ; 80.0 ( 77.188.6 ) for the performance subscale ; 88.6 ( 74.394.3 ) for
execution / power subscale and 77.1 ( 71.482.9 ) for involvement sub - scale .
no associations
were observed between work - related motivation scores and the factors short rest breaks , pain
complaint , and use of a chair back .
the present data revealed that all workers enrolled in the study suffered from pain in at
least one body region .
the prevalence of complaints of pain in the upper limbs and neck
found in this study ( 53.9% ) was similar to that in the study of lacerda et al.3 ( 56.2% ) .
one study from italy10 showed that the neck and low back were the
most prevalent regions of pain ( 50 and 46.5% , respectively ) , corroborating the high
prevalence found for these regions in the present study .
this can be explained by the
posture adopted during the workday : a high number of hours in a seated position ( nine hours
per day ) and bending of the neck ( inherent to computer use ) .
a survey conducted in the
united kingdom6 showed that prolonged
bending of the neck was a risk factor for neck , shoulder , elbow , and forearm pain , with odds
ratios for this factor decreasing markedly from the most proximal to the most distal
area .
a higher prevalence of shoulder pain was expected for those subjects who frequently assume
the lateral decubitus position as their sleep position , since this posture increases
pressure on the shoulders .
the lateral decubitus position entails a smaller area of contact
between the body and the bed than the supine or prone positions and therefore a greater per
unit of area pressure on this body region23 .
no association between sleep position and presence of pain in any
studied body region was found probably because of the small number of subjects who adopted
the lateral decubitus position .
workplace anthropometric measurements showed similar values for thigh length when compared
with those presented by leyk et al.24
( 56 cm vs. 61 and 58 cm the median values for males and females ,
respectively ) .
the leg height when sitting was also comparable to those found by leyk et
al.24 ( 52 cm vs. 54 and 50 cm for males
and females , respectively ) . when observing the eye height when sitting and the computer screen height , it was found
that the monitors were placed slightly lower than eye height .
the recommendation to lower
the screen height is an issue already discussed for more than ten years ago by
burgess - limerick et al.4 the high values
for neck extension found when a person sets a monitor higher than eye height lead to
vertebra posterior compression , which could be associated with neck pain .
nevertheless ,
excessive neck flexion , in cases of a very low position for a computer monitor , can also be
associated with pain .
data from another study showed that prolonged bending of the neck was
associated with a higher prevalence of neck and upper limb pain6 .
marcus et al.5 included an elbow angle higher than 121 degrees as a protective
factor for neck and shoulder symptoms .
the association between wrist pain and shoulder abduction found in the present results
indicates that this angle must be taken into consideration in ergonomics evaluations .
high
values for the shoulder abduction angle augment the probability for greater ulnar deviation .
marcus et al.5 measured the shoulder
abduction angle but did not analyze the association between this angle and hand pain .
they
only considered it as a postural risk factor for neck and shoulder pain , but no association
was found .
the usa25 showed that keyboard activities caused higher median trapezius
activity when compared with computer mouse use .
furthermore , the authors also verified that
shoulder rotation varied from 25 degrees of internal rotation while using a keyboard and
from 15 degrees of external rotation while using a mouse .
another study examining the
keyboard use showed that without a pad , wrist extension increased 4 degrees when compared
with typing with a pad to support the wrists26 .
sim et al.6 demonstrated that little job
control and little supervisor support increased the risk of pain .
hence , psychosocial
factors at work must be investigated , as performed by the present study with quality of life
and motivation at work assessments .
the median motivation scores in the present study varied
from 77.1 to 88.6 , showing a good motivation profile for the present sample . in a study by
machado
et al.8 in portugal , 25.8% of all
the university workers that answered their questionnaire ( total sample = 3,221 ) were
unmotivated and 26.4% were dissatisfied .
it is important to notice , however , that the cited
study used a different method to evaluate motivation .
the median quality of life scores obtained in the present study were higher than 70 ( except
for the vitality and role - emotional domains ) .
a recent statement from the international
commission on occupational health9
corroborates the importance of evaluation of psychosocial factors , affirming that
musculoskeletal discomfort that affects quality of life needs to be prevented .
if it is
already established , it must be identified and treated as soon as possible due to its high
implications in the subject s life .
one limitation of the present study is that even though we assured the subjects that
individual answers would not be revealed to their manager , some workers might have avoided
disclosing their true condition out of fear that this could affect their jobs .
furthermore ,
our visit to evaluate risk factors represents only one moment in time and does not describe
the whole range of postures and movements during the workday .
another important limitation
was the absence of some key measurements , like the distance from the j key on the keyboard
to the table edge , which was significantly associated with hand and arm symptoms in a study
carried out in the usa5 .
the analysis of
both sexes in only one group could also be questioned , but women did not present more
symptoms than men in a previous study5 .
the small sample size was due to the number of workers in the studied department of the
university center where this study was carried out .
the authors restricted the evaluation to
this department because the job tasks during the workday are similar between the measured
subjects .
more studies must be carried out with other types of computer devices , like notebooks ,
netbooks , tablets , and mobile phones .
recently , researchers analyzed the use of
notebooks27 and the use of a touch
screen in a desktop pc setting28 , but
more studies are required .
furthermore , a variety of ergonomics interventions must be tested
in future studies to verify their ability to reverse this pain profile in brazilian office
workers who use a computer at work , as already done in italy10 . for future studies , the authors suggest a greater number of evaluated employees and
investigation about the effect of an ergonomics program , especially controlling workstation
measurements and adoption of short breaks during the workday .
the present study showed that complaints of pain were associated with no short rest breaks ,
no use of a chair back , poor sf-36 bodily pain domain , high head protrusion , and shoulder
angle while using the mouse of a computer .
these findings highlight the importance of
ergonomics evaluations and interventions for computer workers in the workplace . | ### Summary:
: [ purpose ] complaint of pain is common in computer workers , encouraging the investigation
of pain - related workplace factors .
this study investigated the relationship among
work - related characteristics , psychosocial factors , and pain among computer workers from a
university center .
[ subjects and methods ] fifteen subjects ( median age , 32.0 years ;
interquartile range , 26.834.5 years ) were subjected to measurement of bioelectrical
impedance ; photogrammetry ; workplace measurements ; and pain complaint , quality of life ,
and motivation questionnaires .
[ results ] the low back was the most prevalent region of
complaint ( 76.9% ) .
the number of body regions for which subjects complained of pain was
greater in the no rest breaks group , which also presented higher prevalences of neck
( 62.5% ) and low back ( 100% ) pain .
there were also observed associations between neck
complaint and quality of life ; neck complaint and head protrusion ; wrist complaint and
shoulder angle ; and use of a chair back and thoracic pain .
[ conclusion ] complaint of pain
was associated with no short rest breaks , no use of a chair back , poor quality of life ,
high head protrusion , and shoulder angle while using the mouse of a computer . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: superficial acral fibromyxoma ( saf ) is a rare benign tumor that appears frequently in the fifth decade of adult life .
it is a soft - tissue tumor often reported in the subungual and periungual regions of fingers and toes .
it was recognized as a distinct clinical and pathological entity after fetsch et al .
published a clinico - pathological and immunohistochemical analysis of 37 patients presenting a special soft - tissue tumor with predilection for fingers and toes .
the diagnosis and treatment of nail unit tumors always represent a challenge . the technical difficulties of a nail unit biopsy , the painful procedure and the patient s concern for permanent nail dystrophy subsequent to this procedure , place the doctors in a difficult position .
because subungual tumors do not have specific clinical manifestations , imaging represents an important step in evaluation and differentiation of these tumors .
dermoscopy allows in vivo evaluation of different parts of the nail apparatus , being able to describe colors and its microstructure .
high frequency ultrasonography ( hfus ) and color doppler imaging are effective methods to evaluate tumors , but are limited in tissue characterization
. the tumoral detection can be impeded by various artefacts , small tumor size , and also flat tumor shape .
elastography is also a non - invasive method that allows in vivo evaluation of soft - tissue elasticity , being able to increase the specificity of us in assessment of tumors . in this case report
we discuss and illustrate a rare acral tumor involving the nail apparatus , and correlate for the first time the dermoscopic and ultrasonographic features with clinical and pathological findings .
a 62 year old woman referred to the dermatology department with a 4 months history of enlarging subungual mass on the first left toe .
she reported repeated trauma , pain when she wore closed shoes and pigmentation nail changes over the last year .
physical examination of the toe nail revealed a 15 mm , firm , painful , reddish- yellow nodule that destroyed the distal nail plate , partial yellow - brown nail discoloration , and thickening of the nail ( figure 1a ) .
dermoscopy ( dermlite dl3n- 3gen usa ) revealed structureless brown discoloration , structureless homogeneous red , whitish and yellow areas ( figure 1b ) .
b - mode gray ultrasonography ( us ) showed a nodular , hypoechoic , inhomogeneous , 12.7/20.2 mm structural lesion that distorted the nail and presented a cranial hypoechoic extension ( figure 2a ) . on color doppler examination the lesion presented variable vascularity and necrotic zones ( figure 2b ) .
a diagnostic biopsy was performed and revealed a polypoid , ulcerated , and well vascularised neoplastic dermal tumor ( figure 3a ) .
a proliferation of fusiform cells immersed in a myxoid stroma with no relevant atypia was described ( figure 3b ) .
immunohistochemical ( ihc ) study reported positive results for cd34 ( figure 4a ) , cd99 ( figure 4b ) , cd10 ( figure 4c ) and was negative for ema .
the therapeutic approach included complete removal of the tumour , as well as the nail , with wide resection margins in order to avoid recurrence .
saf is a nodular soft - tissue tumor , of solitary presentation and various consistency , from gelatinous to firm .
different clinical presentations were reported varying in shape and color : flesh - colored , white , pink , red nodular mass with a dome , verrucous or polypoid shape .
studies usually report a slow - growing tumor that varies in size from a few mm to several cm in diameter and can appear months to years prior to evaluation .
saf has a predilection for male sex with a sex ratio estimated as 2:1 . from almost 260 cases of saf reported in literature only five cases
had sub - matricial presentation : three had solely submatricial localization and in two cases there was a secondary sub - matricial extension of a saf affecting the nail bed .
the particularity of our case is the appearance of the lesion in a woman , as a firm , painful , nodular mass with a reddish - yellow appearance , affecting the nail bed with a sub - matricial extension identified only in the b - mode us .
dermoscopy is a very useful tool in the evaluation of pigment or vessels within a nail lesion , but is unable to evaluate the inner structure of the nail bed .
dermoscopically , the patient s nail presented with a structureless yellow - brown discoloration and partial nail plate destruction which are characteristic of a fungal infection .
the nodular nail bed lesion showed structureless homogeneous red areas ( figure 1 b ) , which usually appear in vascular lesions or in amelanotic / hypomelanotic melanoma , associated with structureless , homogeneous whitish and yellow areas which are characteristic of squamous lesions .
our findings suggest that subungual saf has nonspecific dermoscopic characteristics , but larger studies are needed to confirm this hypothesis .
some studies have showed that hfus completed by color doppler examination of subungual tumors provides useful information about tumor size , location and shape of the tumour and also the internal characteristics : vascular , cystic , solid or mixed .
color doppler us can appreciate tumor vascularization , the blood flow amount , the size and the distribution of vessels within the tumor adding important information for the final diagnosis . in our case
the us features were concordant with those described in the literature , but we found no correlation between the dermoscopic and us appearance of vessels . for a better evaluation we decided to perform elastography , which has an important role in evaluation of extra cutaneous tumors , but has no established role in the assessment of nail tumors .
our tumor showed intermediate rigidity in elastography being the first case reported in the literature of subungual saf examined by elastography ( figure 2c ) which was useful in evaluation .
although it is postulated that benign tumors respect the general architecture of the nail , up to 96% of toe tumors involve and can destroy the nail architecture .
there are studies who reported erosions or lytic lesions of underlying bones in a third of cases .
the histopathology of saf is characterized by the presence of a non encapsulated , well - circumscribed tumor of the dermis sometimes with extension into the subcutaneous tissue , fascia or periosteal layer .
the tumor contains stellate or spindle - shaped fibroblast - like cells which are arranged in a storiform or fascicular growth pattern with a myxoid , myxocollagenous or predominantly collagenous surrounding stroma .
the presence of mast cells in an increased number and an accentuated vasculature can be observed .
the ihc profile of saf is characterized by the presence of diffuse or focal expression of cd34 in up to 90% of cases .
staining for s-100 , hmb-45 , sma , desmin , actin and cytokeratin is negative [ 13,7,8 ] .
the ihc study in our case showed positive results for cd34 , cd99 and cd10 and was negative for ema ( figure 4a , b , c ) .
there were reports of cases treated by partial excision , and partial / complete digital amputation .
the incomplete tumoral excision can lead to persistent or recurrent cases in up to 20% of cases . in our case
the radical surgery with wide resection margins lead to no recurrence after 12 months of follow - up .
this is the first reported case in the literature of subungual saf described clinically , dermoscopically and by us examination ( b - mode us , colour doppler , strain elastography ) . | ### Summary:
: there is a large spectrum of tumors presenting as nodular lesions that may affect the subungual space .
we report the case of a 62-year - old woman presenting with a rapidly growing nodular lesion under the nail of the first left toe .
non - invasive examinations using dermoscopy , ultrasonography and elastography were performed for the preoperative assessment of the lesion .
the biopsy of the lesion revealed superficial acral fibromyxoma , a benign tumor with predisposition for acral sites .
the patient underwent radical surgery with wide resection margins .
this is the first case report of a superficial acral fibromyxoma affecting the subungual region characterized by dermoscopic , ultrasonographic and elastographic features .
we also performed a short review of the literature . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: hip fractures , which are common among old patients , are classified into two groups : intracapsular and extracapsular fractures .
extracapsular fractures can be treated with extramedullary implants [ e.g. dynamic hip screw ( dhs ) ] or intramedullary nails .
we report a case of a 90-year old caucasian woman who had an unusual intraoperative complication during osteosynthesis procedure for extracapsular hip fracture fixation .
this mishap required an abdominal surgical approach by the general surgeon to remove the screw .
taking into consideration the poor quality of the bone in very old patients , we emphasize the importance of following every single step of the surgical procedure , in order to minimize the risk of this complication .
hip fractures , which are common among old patients , are classified into two groups : intracapsular fractures and extracapsular fractures .
generally , the positioning of dhs is considered a simple procedure and it is widely used .
five steps are followed in order to reduce and stabilize extracapsular hip fractures with dhs :
reduction of the fracture under x - ray control;positioning one k - wire to stabilize the fracture and another one in the middle of the femoral neck to guide the cephalic hollow screw;positioning the cephalic hollow screw in the correct position using the k - wire guide;wedging the plate into the cephalic screw;fixing the dhs to the femur diaphysis with the necessary screws .
reduction of the fracture under x - ray control ; positioning one k - wire to stabilize the fracture and another one in the middle of the femoral neck to guide the cephalic hollow screw ; positioning the cephalic hollow screw in the correct position using the k - wire guide ; wedging the plate into the cephalic screw ; fixing the dhs to the femur diaphysis with the necessary screws .
several perioperative complications have been described in medical literature . however , only two case reports described cephalic screw migration into the pelvis during surgical procedure .
moreover , few articles report intrapelvic migration of the cephalic screw in the postoperative period [ 6 - 13 ] . here
we present a rare complication which occurred during the fourth step of the dhs technique and led to intrapelvic migration of the cephalic screw .
we report the case of a 90-year old female who was admitted to our traumatology department to fix an extracapsular hip fracture of the left femur which occurred during a low - energy trauma .
the history of the patient revealed that she suffered from osteoporosis . in her eighties , she had been conservatively treated with a cast for a right wrist fracture .
previously the patient had been treated for four vertebral compression fractures with thoraco - lumbar orthosis .
spine and femur dexa scan measurements at the time of the vertebral fractures showed t - score of -4.9 and -3.7 , respectively , confirming a severe osteoporosis .
the operation was performed under general anesthesia , with the patient positioned on a fracture table .
thereafter the surgeon began placing two k - wires into the femoral head through the femoral neck with a lateral skin incision .
a complication occurred in this step , as the surgeon found out that the first k - wire had been broken .
next the cephalic screw was positioned in the middle of the femoral neck using k - wire to guide the insertion of the dynamic screw . due to the severe osteoporosis ,
the surgeon decided to ream only the lateral cortex of the femur to boost the grip strength .
the ensuing step was to slide the lateral plate to the cephalic screw until the internal side of the plate was seated on the lateral cortex of the femur .
owing to difficulties in placing the plate , the surgeon decided to use the mallet . during x - ray control of this surgical step , the cephalic screw appeared to have unexpectedly migrated into the pelvis ( fig 1 ) .
several attempts with different surgical forceps were made to remove it through the screw hole , but the screw had penetrated deeply into the pelvis making it impossible to retrieve it . the general surgeon was called to perform an abdominal approach to remove the screw , which was finally retrieved in a few minutes without any further complications .
meanwhile , the procedure of osteosynthesis was completed using a condylar plate ( fig 3 ) .
the patient started postoperative physical reconditioning three days after , with only one day s delay compared to standard procedure .
the k - wire fragment torn in the first step of the procedure can be seen scheme showing the positioning of the dhs with and without a lag screw extender : a - b : without a lag screw extender - a ) normal sliding of the plate onto the cephalic screw , with an angle of 180. b ) incongruence between cervical screw and plate , with an angle of less than 180. in this situation , when the surgeon pushes the plate to engage the screw ( the empty arrow indicates the direction of the force ) , the acetabulum could break .
c - d : with a lag screw extender - c ) the lag screw extender ( arrowhead ) is tightened ( white curve arrow ) on the cephalic screw to guide the plate .
this is the easiest and safest mode to slide the plate onto the screw a ) intraoperative positioning of the condylar plate .
the treatment of stable pertrochanteric fractures with dhs is the preferred procedure although medical literature reports numerous complications .
the main intraoperative complications during the insertion of dhs include malassembly ; tearing and migration of the guide wire into the pelvis ; migration of the compression screw ; intrapelvic vascular injury caused by the guide wire .
few cases of postoperative intrapelvic migration of a lag screw are reported [ 10 - 14 ] . in 2007 ,
naido maripuri et al . , reported the first case of intraoperative intrapelvic migration of the sliding hip screw in a 78-year old man .
the authors suggest the use of the mallet to fit the plate on the screw as a possible cause of the complication .
secondly , the authors explain that , in such a case , the premature removal of the lag screw extender did not thwart the migration of the screw .
a third cause of the complication was probably the over - reaming of the femoral neck and head before engaging the plate on the screw . in this patient ,
the surgeon successfully removed the screw from the hole in the bone with a biopsy forceps avoiding an abdominal approach .
more recently , singh et al . , reported a second case of intrapelvic migration of a hip screw in a 55-year old man . like in the case reported above , the surgeon did not use a lag screw extender but hammered the plate over the screw .
the authors assume that the over - reaming of the proximal femur could be the reason for the complication . in this case too , the surgeon removed the screw through the hole in the neck with a kocher s forceps without any complications .
after this uncommon but undesirable complication , we analyzed every possible cause of the procedural flaw with our patient .
first , we evaluated if we had followed the surgical techniques reported in the dhs manual correctly .
the orthopedic surgeon who performed the operation was a senior surgeon of proven experience who had treated several femoral fractures with dhs in his career .
taking such facility and experience for granted , some steps must be scrutinized and some kit - device must be spared . in this case , the surgeon did not use all the instruments presented in the basket of the dhs implant , which included a lag screw extender ( fig 2 ) .
this instrument is a threaded rod which fixes the head screw during the plate sliding procedure . in our opinion , failing to use a lag screw extender is the principal cause of this complication , both in our case and in the other ones reported in medical literature .
moreover , a close examination of the instructions for using d h s devices coming from different companies revealed that this significant step is unexpectedly omitted . on analyzing the whole surgical procedure of our case in detail , we also noticed that a second cause could be an incorrect alignment between the octagonal hole of the plate and the octagonal shape of the screw .
this incongruence may originate several multidirectional forces in the threaded part of the screw while using the mallet , resulting in a relocation of the screw across the pelvic bone ( fig 2 ) .
finally , we think that the poor quality of the bone engendered by osteoporosis is a high - risk factor for pelvic bone damage caused by a cephalic screw , which can easily penetrate into the pelvis . indeed , especially on using the mallet , the surgeon could not perceive the bone resistance of the acetabular notch . in our case , unlike the other two clinical reports , the screw was removed by the abdominal surgeon with extraperitoneal approach , a safe , easy and fast procedure which lets the screw out without damaging internal organs . on the contrary , removing the screw from the hole of entry does not ensure that bowels will not be damaged .
in fact , this approach makes it impossible to see the threaded part of the screw , which could pull out some soft tissue during the removal .
we also wish to emphasize the jeopardy involved in tapping with the mallet when the plate does not slide on the cephalic screw . on the contrary
, this step requires performing gentle manual movements , in order to find a geometrical congruence between plate and screw ( fig 2 ) .
furthermore , it is important to use a lag screw extender without removing it until the plate is fixed to the lateral cortex of the femur and the image intensifier confirms its right position .
indeed , we are convinced that this is the main measure to avoid this complication .
suffice it to say that a lag screw extender was not used in our case , nor in the one reported by singh , while in the case contributed by naido maripuri the lag screw extender was removed earlier than required . in this case
, the cause of the problem can not be ascribed to the over - reaming of the bone as reported in the other two cases , inasmuch as the surgeon did not ream the neck of the femur but only the lateral cortex to increase the grip between screw and bone . on the other hand
, severe osteoporosis contributed to the pelvic migration of the screw , especially on using the mallet . in the only two cases regarding intrapelvic migration reported in medical literature
our case report underlines the importance of scrupulously following the steps of dhs surgical technique , particularly in the application of a lag screw extender . as a matter of fact
, the use of the mallet to slide the plate on the screw should be discouraged .
if the plate and the screw are not on the same plane , it is recommended to manually control the rotation of the plate until they are congruent .
this should be made mandatory , especially when treating very old osteoporotic patients . finally , in the event of such an unfortunate complication
, we would suggest resorting to an extraperitoneal approach to remove the intrapelvic screw , a far safer and faster procedure .
awareness of such potential event and scrupulous adherence to the dhs surgical technique , especially when treating very old osteoporotic patients , can avoid this complication .
following the steps of dhs surgical technique is mandatory , even for expert surgeons , particularly in the application of a lag screw extender , in order to avoid intrapelvic screw migration . in case of such complication , | ### Summary:
: introduction : hip fractures , which are common among old patients , are classified into two groups : intracapsular and extracapsular fractures .
extracapsular fractures can be treated with extramedullary implants [ e.g. dynamic hip screw ( dhs ) ] or intramedullary nails .
dynamic hip screw is the treatment of choice in stable pertrochanteric fractures .
intrapelvic migration of the sliding screw is a very rare complication.case report : we report a case of a 90-year old caucasian woman who had an unusual intraoperative complication during osteosynthesis procedure for extracapsular hip fracture fixation .
in fact , the sliding hip screw went deep into the pelvis during surgery .
this mishap required an abdominal surgical approach by the general surgeon to remove the screw.conclusion:taking into consideration the poor quality of the bone in very old patients , we emphasize the importance of following every single step of the surgical procedure , in order to minimize the risk of this complication . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the online version of this article ( doi:10.1007/s40121 - 015 - 0087 - 5 ) contains supplementary material , which is available to authorized users .
pneumonia remains among the top 10 most common causes of mortality for all age groups in the united states and the most common infectious cause of mortality . in the united states in 2013 ,
pneumonia is commonly caused by viral or bacterial pathogens with the former being responsible for 2939% of cases [ 3 , 4 ] .
physical examination , routine microbiological testing of respiratory samples and radiologic findings are not routinely reliable in establishing an accurate diagnosis of bacterial pneumonia [ 68 ] .
polymerase chain reaction ( pcr ) technology has been adopted into clinical use for the rapid identification of various pathogens .
multiplex pcr technology has recently been added to allow the identification of a panel of potential respiratory pathogens in contrast to older pcr technologies that only identified a single target .
biomarkers have been examined for their diagnostic utility as another approach to differentiate bacterial infections from other types of inflammatory states . while biomarkers such as c - reactive protein and erythrocyte sedimentation rate are often elevated in both infectious and noninfectious conditions , procalcitonin ( pct ) levels
are routinely elevated in the presence of bacterial infections while remaining low in the setting of other types of inflammatory processes [ 912 ] .
the use of this test as a decision tool has been established as a safe method for ruling out bacterial infections and thus reducing antibiotic use . however , while low serum levels of pct are suggestive of the absence of bacterial infection , it does not exclude it , and therefore results should always be used in conjunction with clinical judgment with particular caution given in interpreting these results in seriously ill patients . despite the advances in and clinical application of such diagnostic technologies , it has been reported that many patients nonetheless continue to receive antibiotic therapy without regard to positive viral pcr and/or low pct results [ 1416 ] .
it was our objective to determine the frequency of changes in empiric antibiotic therapy for known or proven cases of pneumonia once results of respiratory panels ( rp ) and/or pct testing were known to the clinician and thus determine the need for an active stewardship intervention at our own institution .
this retrospective , single - center study was performed at the medical university of south carolina hospital , a 709 bed tertiary and quaternary academic medical center .
average adult inpatient length of stay , age and case - mix index are 6.2 days , 52 years , and 1.9642 , respectively .
a hospital s case - mix index represents the average diagnosis - related group ( drg ) relative weight for that hospital .
it is calculated by summing the drg weights for all medicare discharges and dividing by the number of discharges .
it is used in determining the allocation of resources to care for and/or treat the patients in the group .
this article does not contain any new studies with human or animal subjects performed by any of the authors .
records accessed were from patients 18 years of age or older with proven or suspected respiratory infections as indicated by pcr , respiratory bacterial culture , or the international statistical classification of diseases and related health problems 9th revision ( icd-9 ) code for acute infectious respiratory illness ( icd-9 codes 460466 and 480488 ) associated with a hospitalization between january 01 , 2012 and january 01 , 2014 .
all patient records evaluated were required to have a rp or pct within the first 72 h of presentation .
patients with cystic fibrosis based on icd-9 or patients with positive bacterial cultures were excluded .
additionally , patients with copd , chronic bronchitis , or emphysema were excluded as a lack of utility of pct in distinguishing viral from bacterial respiratory illness in copd has been described .
copd chronic obstructive pulmonary disease , icd-9 international classification of diseases 9th revision , pct procalcitonin , rp respiratory panel flow diagram for study design and data collection / analysis .
copd chronic obstructive pulmonary disease , icd-9 international classification of diseases 9th revision , pct procalcitonin , rp respiratory panel procalcitonin concentrations were determined with the vidas brahms pct automated test ( biomrieux , marcy , france ) .
pct has a reported sensitivity of 88% and specificity of 81% in distinguishing a bacterial infection from other inflammatory processes .
routine laboratory reporting denotes values of < 0.25 g / ml as suggestive of a bacterial infection being unlikely .
the presence of respiratory viruses was determined with the filmarray respiratory panel ( biofire diagnostics , inc . ,
this test detects 17 viruses including adenovirus , coronavirus 229e , coronavirus hku1 , coronavirus nl63 , coronavirus oc43 , human metapneumovirus , influenza a , influenza a subtype h1 , influenza a subtype h3 , influenza a subtype 2009 h1 , influenza b , parainfluenza virus 1 , parainfluenza virus 2 , parainfluenza virus 3 , parainfluenza virus 4 , rhinovirus / enterovirus , and respiratory syncytial virus .
results were available in one hour once specimen was obtained with a sensitivity and specificity that are 80100% and 100% , respectively .
no institutional protocol or guidance on the use / interpretation of pct was in place at the time of the study .
neither test had education provided on their use during their implementation or during our analysis period .
no specific antimicrobial stewardship activities or initiatives were in place specific for these tests during the study .
patient data collected included age , sex , co - morbid conditions , diagnoses , intensive care unit admission , antibiotic use and duration , and the results of bacterial cultures if obtained , pct , and rp .
drug orders were evaluated for discontinuation of therapy within 48 h of a procalcitonin of < 0.25 g / ml , a positive viral result , or both .
analysis was performed in excel 2013 ( microsoft , redmond , wa , usa ) .
figures were created using excel 2013 and inkscape 0.91 ( free software foundation , inc . , boston , ma , usa ) .
this retrospective , single - center study was performed at the medical university of south carolina hospital , a 709 bed tertiary and quaternary academic medical center .
average adult inpatient length of stay , age and case - mix index are 6.2 days , 52 years , and 1.9642 , respectively .
a hospital s case - mix index represents the average diagnosis - related group ( drg ) relative weight for that hospital .
it is calculated by summing the drg weights for all medicare discharges and dividing by the number of discharges .
it is used in determining the allocation of resources to care for and/or treat the patients in the group .
this article does not contain any new studies with human or animal subjects performed by any of the authors .
records accessed were from patients 18 years of age or older with proven or suspected respiratory infections as indicated by pcr , respiratory bacterial culture , or the international statistical classification of diseases and related health problems 9th revision ( icd-9 ) code for acute infectious respiratory illness ( icd-9 codes 460466 and 480488 ) associated with a hospitalization between january 01 , 2012 and january 01 , 2014 .
all patient records evaluated were required to have a rp or pct within the first 72 h of presentation .
patients with cystic fibrosis based on icd-9 or patients with positive bacterial cultures were excluded .
additionally , patients with copd , chronic bronchitis , or emphysema were excluded as a lack of utility of pct in distinguishing viral from bacterial respiratory illness in copd has been described .
copd chronic obstructive pulmonary disease , icd-9 international classification of diseases 9th revision , pct procalcitonin , rp respiratory panel flow diagram for study design and data collection / analysis .
copd chronic obstructive pulmonary disease , icd-9 international classification of diseases 9th revision , pct procalcitonin , rp respiratory panel
procalcitonin concentrations were determined with the vidas brahms pct automated test ( biomrieux , marcy , france ) .
pct has a reported sensitivity of 88% and specificity of 81% in distinguishing a bacterial infection from other inflammatory processes .
routine laboratory reporting denotes values of < 0.25 g / ml as suggestive of a bacterial infection being unlikely .
the presence of respiratory viruses was determined with the filmarray respiratory panel ( biofire diagnostics , inc . ,
this test detects 17 viruses including adenovirus , coronavirus 229e , coronavirus hku1 , coronavirus nl63 , coronavirus oc43 , human metapneumovirus , influenza a , influenza a subtype h1 , influenza a subtype h3 , influenza a subtype 2009 h1 , influenza b , parainfluenza virus 1 , parainfluenza virus 2 , parainfluenza virus 3 , parainfluenza virus 4 , rhinovirus / enterovirus , and respiratory syncytial virus .
results were available in one hour once specimen was obtained with a sensitivity and specificity that are 80100% and 100% , respectively . no institutional protocol or guidance on
the use / interpretation of pct was in place at the time of the study .
neither test had education provided on their use during their implementation or during our analysis period .
no specific antimicrobial stewardship activities or initiatives were in place specific for these tests during the study .
patient data collected included age , sex , co - morbid conditions , diagnoses , intensive care unit admission , antibiotic use and duration , and the results of bacterial cultures if obtained , pct , and rp .
drug orders were evaluated for discontinuation of therapy within 48 h of a procalcitonin of < 0.25 g / ml , a positive viral result , or both .
analysis was performed in excel 2013 ( microsoft , redmond , wa , usa ) .
figures were created using excel 2013 and inkscape 0.91 ( free software foundation , inc . , boston , ma , usa ) .
of 4869 individual patient records with pct and/or rp results , 2031 met inclusion for the study ( fig . 1 ) .
results of pct and rp testing were available in 503 and 1823 patients , respectively , with 295 patients having both .
of tests performed in the first 72 h , the results suggested that 789 ( 38.8% ) patients may have had opportunities for antibiotic avoidance . in total , 219 patients with a pct < 0.25 g / ml , 601 with a positive pcr , and 31 with both were identified . of patients with testing results in the first 72 h
, antibiotics were administered to 307 patients ( 38.9% ) during the same period ( table 1 ) .
the most frequently detected respiratory viruses were influenza a / b ( 34% of total ) and rhinovirus / enterovirus ( 30% ; fig . 2 ) .
of the 307 patients prescribed antibiotics within the first 72 h , antibiotics were discontinued within 48 h of laboratory results in 60 ( 19.5% ) patients with either a pct < 0.25 g / ml , a positive pcr , or both ( table 2 ) .
the median duration of antibiotics was 3 days for all of these groups and ranged from 1 to 19 days , 1 to 27 days , and 1 to 13 days for a pct < 0.25 g / ml , a positive rp , or both , respectively.table 1patient characteristicspct < 0.25 g / l ( n = 219)positive viral rp ( n = 601)pct < 0.25
g / l and positive viral rp ( n = 31)median age , years ( iqr)58 ( 4469)47 ( 3360)55 ( 4167)male sex , n ( % ) 94 ( 42.0)256 ( 42.6)15 ( 48.4)charlson score , median ( iqr)1 ( 12)1 ( 01)1 ( 12)icu admission during hospitalization , n ( % ) 89 ( 40.6)53 ( 8.8)13 ( 41.9)median length of stay , days ( iqr)4 ( 26)1 ( 03)3 ( 26)antibiotic prescribed within first 72 h156 ( 71.2)170 ( 28.2)19 ( 61.3 )
icu intensive care unit , iqr interquartile range , pct procalcitonin , rp respiratory panelfig
. 2viruses identified by polymerase chain reaction ( percent of total)table 2antibiotics discontinued within 48 h of pct and rp resultspct < 0.25 g / ml ( n = 156)positive viral rp ( n = 170)pct < 0.25 g / ml and positive viral rp ( n = 31)antibiotics discontinued , n ( % ) 32 ( 20.5)30 ( 17.6)2 ( 10.5)median length of stay , days ( iqr)4 ( 37)4 ( 26)5 ( 37 )
iqr interquartile range , pct procalcitonin , rp respiratory panel patient characteristics
icu intensive care unit , iqr interquartile range , pct procalcitonin , rp respiratory panel viruses identified by polymerase chain reaction ( percent of total ) antibiotics discontinued within 48 h of pct and rp results
iqr interquartile range , pct procalcitonin , rp respiratory panel
the problem of inappropriate use of antibiotics leading to antibiotic - resistant organisms can not be overstated .
this issue has escalated to being nationally recognized and addressed in the white house s national action plan for combating antibiotic - resistant bacteria , which among other initiatives , calls for increased antimicrobial stewardship activities for the judicious use of antimicrobials and for innovation in rapid diagnostics to facilitate that effort . in the outpatient setting including the emergency department , the majority of antibiotic prescribing has been for patients presenting with respiratory conditions .
many such infections are of viral origin including nearly 30% of pneumonias [ 3 , 4 ] . in turn
, much antibiotic prescribing for respiratory infections in outpatients is unwarranted [ 21 , 22 ] .
this overuse can be explained to a large extent by the inherent difficulty in clinically differentiating bacterial from viral infection . at the same time
, it appears that the treatment of respiratory tract infections represents a major area of opportunity for more judicious and limited use of antibiotics .
the use of pct and rp alone , or in combination , has been successfully and safely used to guide diagnosis and therapy [ 13 , 2427 ] .
a number of studies have shown pct to be an effective test to utilize in altering antibiotic prescribing patterns without adversely affecting patient outcomes [ 13 , 24 , 25 ] . in these studies ,
empiric antibiotics therapy was strongly discouraged and/or recommended for discontinuation in patients with low pct levels .
similar to the use of pct to rule out bacterial infections , positive results of rp have been shown to be useful in efforts to reduce antibiotic use as they provide direct proof of viral respiratory infections .
afzal s and colleagues use of rp results led to a reduction in antibiotic duration when that information was made available to the primary care provider .
patients in whom the positive viral rp was disclosed to the primary care provider ( n = 11 ) had a median duration of antibiotics of 7 days as opposed to 12 days ( p = 0.05 ) in patients with proven bacterial infection ( n = 28 ) .
furthermore , when a positive viral pcr was not disclosed ( n = 19 ) , the median duration of antibiotics was 12 days similar to the bacterial infection group .
these findings of decreased antibiotic exposure based on viral pcr were also reported by oosterheert and colleagues . in their study , positive pr results led to a discontinuation of antibiotics in 11% of patients
. one potential challenge of the reliance on these rapid tests to rule out bacterial infection is co - infection with viral and bacterial pathogens , which has been reported in 1440% of cases of infectious pneumonia [ 14 , 28 , 29 ] .
co - infection has recently been explored by musher and colleagues in a study analyzing the etiology of community - acquired pneumonia ( cap ) in a cohort of hospitalized cap patients in a us veterans administration hospital .
of 259 , 4.6% were found to be co - infected with a virus and a bacterium or fungus .
however , in the 42 cases of viral infection , 12 ( 28.5% ) had a documented bacterial co - infection . in patients with severe cap requiring mechanical ventilation ,
co - infection may occur more often . in a study by karhu and colleagues , bacterial
importantly , these investigators reported that pct concentrations actually helped distinguish bacterial from non - bacterial infections . within their bacterial / viral co - infection patients ,
median admission and peak pct concentrations were 20.1 and 24.3 g / l , respectively , while those values in the viral infection group were 1.4 and 1.7 g / l , respectively .
these data are consistent with previous pct data in suggesting that such results are effective in discriminating between viral and bacterial infections .
however , it should be noted that while many of the aforementioned studies establish pct as a safe and effective way of ruling out bacterial infections , others have cast doubt on sensitivity [ 16 , 31 ] with one group reporting a sensitivity of approximately 40% .
other biomarkers may have a role in improving the use of this test [ 32 , 33 ] .
we studied clinician - prescribing behavior at our institution once rp and/or pct laboratory results were available to the prescribing physician and were suggestive of a pure viral respiratory infection .
we observed antibiotic discontinuation rates of only 1720% in patients with positive viral rp results or pct < 0.25 g / ml . in patients with both test results available (
n = 31 ) , and highly suggestive of a pure viral infection , antibiotic discontinuation rates were even lower ( 10% ) .
one possible explanation for the low rates of antibiotic discontinuation could relate to the relatively low prescribing of antibiotics ( 38.9% ) to patients with proven or suspected respiratory infections which had either a low pct , a positive viral rp result , or both .
we believe the relatively low incidence of prescribing in this context suggests many prescribers avoided antibiotic therapy based on other clinical factors suggesting a non - bacterial illness causing respiratory symptoms .
an earlier study by falsey and colleagues of respiratory illness reflected similar results to ours substantiating the opportunity for more judicious antimicrobial use based on the results of rp and pct . in this single - center study , patients were deemed to have a pure viral infection if a viral test was positive , all bacterial tests were negative , and serum pct levels were < 0.25 g / ml on admission and day two of hospitalization .
duration of inpatient antibiotics was found to be significantly less in the viral alone group as compared to the mixed viral
these data suggest an opportunity in the use of combining rp and pct results to narrow the etiologic diagnosis and perhaps decrease unnecessary antibiotic exposure .
while mixed viral bacterial infection was noted in 40% of patients , the utilized diagnostic battery appeared to distinguish these from pure viral infections .
it is also notable , however , that while rp and pct results suggesting pure viral infections resulted in shorter durations of antibiotic therapy , the average duration of therapy extended more than 2 days beyond the availability results of rp and pct testing .
recently , in a follow - up study , antibiotic prescribing patterns associated with low pct and positive viral rp results in patients with non - pneumonic lower respiratory tract infections were characterized into two groups of patients , one receiving standard of care and the second receiving care specified by use of pct algorithms and viral testing .
the investigators observed antibiotic discontinuation rates of 57% when pct was < 0.25 g / ml and a positive viral rp was reported .
importantly , nonpneumonic was apparently defined as those with clinically suggestive symptoms of lower respiratory tract infection with no clear evidence of or risk factors for bacterial pneumonia .
further , as the previous study was conducted at the same institution as this more recent study and the methods and results of that study were shared with medical staff prior to commencing the latter study , a source of internal bias was likely introduced that would have influenced antibiotic usage / discontinuation rates .
the observation that usage / discontinuation rates did not differ in the comparator groups may substantiate that impression . at the same time
, these studies and the proactive intervention in the second provides further evidence that some proactive intervention , beyond the availability of rapid diagnostic test results , can influence prescribing behavior .
as it was a retrospective , single - center study , the prescribing behavior observed may very well differ from that at other institutions .
as we excluded patients with chronic obstructive pulmonary disease , chronic bronchitis , emphysema , and cystic fibrosis , our results can not be generalized as relevant to respiratory tract infections in these patient populations .
our criteria for antibiotic prescribing were based solely upon availability of and values for three specific tests ( pct , rp , bacterial culture ) .
some patients may have had other indicators suggestive of bacterial pulmonary infection such as severity of illness , indicative signs or symptoms , imaging studies , elevated white cells , or urinary bacterial antigens and so on which would have likely influenced decisions to use / continue antibiotic therapy .
we did not account for the influence of such evidence on prescribing patterns in our analysis and their potential impact is of obvious importance .
additionally , we did not evaluate the timing of antibiotic administration in relation to time of availability of pct or rp test results .
however , studies such as prorata have used higher pct levels to determine appropriate antibiotic discontinuation .
those data suggest that regardless of the timing of administration of antibiotics , our more conservative pct level would have suggested an opportunity for appropriate antibiotic discontinuation .
moreover , the pct level used here for evaluation of antibiotic avoidance or discontinuation is consistent with other studies involving pct guidance of therapy in possible or proven respiratory tract infections [ 15 , 25 , 34 , 35 ] .
finally , to fully characterize the true impact of pct and pcr on antibiotic prescribing , comparisons would need to include all patients with pcr and pct results , not only those patients with results suggestive of mono - microbial viral respiratory infections .
while 2031 patients had proven or presumed respiratory tract infections , only 295 patients had both rp and pct testing .
the challenge of co - infections with viruses and bacteria denotes the need for respiratory infection protocols including both pct and rp tests ordered in the emergency department or upon admission to ensure prompt results for assistance in the clinical decision - making process and the appropriate use of antibiotics .
the combined use of these tests upon admission could have decreased antibiotic use by an average of 2 days in most patients in our study with a positive viral rp , a pct < 0.25 g / l , or both . given issues with pct sensitivity
, it would appear prudent that both tests be employed . with the low rate of antibiotic discontinuation in the setting of positive viral rp and < 0.25
g / ml pct results , there appears to be a need for education of providers .
this education should include reviewing the etiologies of respiratory tract infections , providing pct testing and interpretation information , and the need for judicious use of antibiotics related to potential complications and resistance development .
asps can provide education for practitioners , develop antibiotic guidelines , pct / rp algorithms , and proactively recommend antibiotic discontinuation based upon proper interpretation of pct and rp test results .
proactive intervention , such as that provided by asps is important in ensuring meaningful use of rapid diagnostics as opposed to a lack of clinical benefit in the absence of such asp - facilitated interventions [ 36 , 37 ] .
our findings suggest that pct and rp results , alone or in combination , when indicative of a diagnosis of pure viral respiratory infections are infrequently associated with discontinuation of antibiotic therapy at our institution .
demonstration of this prescribing behavior suggests a possible opportunity for antimicrobial stewardship in the development of a clinical pathway or decision tool and the provision of relevant education on the importance of these tests as well as direct intervention with clinicians with the goal of lessening unnecessary antibiotic use .
additional studies should evaluate variations in antibiotic prescribing through the combination of rp and pct protocols in respiratory tract infections along with stewardship activities of provider education and response to rp and pct results .
t. timbrook , m. maxam and j. bosso declare that they have no conflicts of interest .
this article does not contain any new studies with human or animal subjects performed by any of the authors .
this article is distributed under the terms of the creative commons attribution - noncommercial 4.0 international license ( http://creativecommons.org/licenses/by-nc/4.0/ ) , which permits any noncommercial use , distribution , and reproduction in any medium , provided you give appropriate credit to the original author(s ) and the source , provide a link to the creative commons license , and indicate if changes were made . | ### Summary:
: introductionthe differentiation of viral from bacterial pneumonia is important in determining whether antibiotics are appropriate for treatment of these infections .
advances in diagnostic technologies such as respiratory panels ( rp ) utilizing polymerase chain reactions to detect viruses and determination of procalcitonin ( pct ) concentrations may aid in this differentiation .
however , some studies have shown limited impact for this purpose and thus continuation of antibiotics despite results suggesting viral infection . our objective was to characterize clinician - prescribing behavior at our institution once rp and/or pct results were known and suggestive of a viral respiratory infection.methodsthis retrospective analysis was based upon records of hospitalized patients in whom proven or possible respiratory infections as indicated by rp testing , respiratory bacterial culture or international statistical classification of diseases and related health problems 9th revision codes for acute infectious respiratory illness was documented .
patients evaluated were required to have a rp or pct within the first 72 h of presentation .
drug orders were evaluated for discontinuation of antibiotic therapy within 48 h of a procalcitonin of < 0.25 g / ml , a positive viral rp result , or both.resultsof 4869 patients with pct and/or rp results , 2031 were included .
pct and rp testing were obtained in 503 and 1823 patients , respectively , with 295 patients having both .
results of these tests suggested 789 patients were potential candidates for antibiotic avoidance .
these included 219 with a pct < 0.25 g / ml , 601 with a positive viral rp result , and 31 with both .
antibiotics were administered to 307 patients ( 39% ) within the first 72 h. in these , antibiotics were discontinued within 48 h of laboratory results availability.conclusionthese results suggest that positive viral rp and low pct results are infrequently associated with discontinuation of antibiotic therapy in proven or possible respiratory infections at our institution .
direct interventions with clinicians are likely needed to correct this behavior and decrease unnecessary antibiotic use.electronic supplementary materialthe online version of this article ( doi:10.1007/s40121 - 015 - 0087 - 5 ) contains supplementary material , which is available to authorized users . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: an estimated 536 million people aged 1549 are infected with the herpes simplex virus type 2 ( hsv-2 ) worldwide .
the predominant symptom of the disease is genital lesions , but a majority of infected individuals experience no symptoms or mild ones that are often unrecognized .
the high rate of asymptomatic cases enhances hsv-2 transmission because asymptomatic individuals shed the virus and transmit the disease .
hsv-2 infection in pregnancy has been associated with premature delivery , low birthweight infants , fetal malformations , and vertical transmission of the virus during childbirth [ 4 , 5 ] .
while neonatal herpes occurs in less than 1% of prevalent infections , the risk of transmission increases to 2550% among women infected during pregnancy [ 6 , 7 ] . in addition , it is estimated that prevalent hsv-2 infection is associated with a 2- to 4-fold increased risk of hiv-1 acquisition .
various studies have estimated that about 40% of pregnant women in sub - saharan africa , 30% in latin america , 1722% in north america , and 4 to 24% in europe are hsv-2 infected [ 8 , 1012 ] .
studies from sweden , italy , switzerland , and china show the hsv-2 prevalence in antenatal cases of 10.4% , 7.6% , 20.7% , and 10.8% , respectively [ 10 , 1315 ] .
one cross - sectional study conducted among 1,640 pregnant women attending antenatal clinics in arunachal pradesh , assam , manipur , meghalaya , and mizoram ( all states are located in the northeast of india ) found overall hsv-2 seroprevalence of 8.7% with states ranging from a high of percentage 15% in arunachal pradesh to a low percentage of 2.7% in manipur .
another study of asymptomatic pregnant females attending the obstetrics and gynecology outpatient department for a routine antenatal checkup in the north indian state of jammu found hsv-2 prevalence of 7.5% .
with one antenatal study from tamil nadu , a southern state in india , and limited seroprevalence estimates from other parts of the country , there is a great need for additional studies among pregnant women .
the research describes the prevalence and determinants of hsv-2 infection among pregnant women living in rural villages in mysore taluk , karnataka , india .
public health research institute of india ( phrii ) is a nonprofit organization based in mysore , india .
phrii maintains a public health laboratory and conducts mobile health clinics offering integrated antenatal care and hiv testing services in villages in mysore taluk for pregnant women .
mysore taluk is located in the southern part of the state of karnataka , india .
pregnant women living in rural villages located in mysore taluk were enrolled in the study from january to september 2009 .
pregnant women in the villages were recruited through extensive community outreach and with the assistance of community and local health professionals .
a total of 487 women from 52 villages submitted blood samples to be tested for hsv-2 and hiv .
the institutional review boards at the university of california , berkeley , and public health research institute of india approved the study protocol .
a list of the 141 villages in mysore taluk was obtained through the 2001 indian census and 52 villages were randomly selected to participate in an intervention providing integrated antenatal care and hiv testing using mobile medical clinics .
prior to the health camp , an outreach team met with village leaders and local health professionals to seek permission to work in the community .
the team also met with the national rural health mission workers the auxiliary nurse midwife ( anm ) , the accredited social health activist ( asha ) , anganwadi teacher and helper to discuss the program .
the anganwadi teacher provided a list of registered pregnant women in each of the villages and assisted in referring these women to the health clinic .
mobile health clinics were typically conducted in primary schools or community halls located in each village one day after a community - wide education and awareness program was conducted on the importance of antenatal care and institutional deliveries .
pregnant women were offered a free antenatal screening including clinical examination and laboratory evaluation and completed an interviewer - administered questionnaire .
all pregnant women who came to the mobile medical clinic were offered pretest counseling in groups in the local language of kannada . each woman
was then directed to a private space where she could discuss and ask any questions or clarifications before proceeding further through the program .
then , a trained female interviewer used a standardized questionnaire to collect information on sociodemographic status , work experience and economic status , knowledge about hiv / aids , sexual history , information on main sex partners , history of sexually transmitted infections , and hiv test reports .
after completion of an examination by the physician , a trained nurse collected blood samples from consenting participants to screen for hsv-2 , hiv , and other routine antenatal investigations .
a type - specific elisa was used to detect hsv-2 igg antibodies in sera ( focus technologies , cypress , ca , usa ) .
tests were performed following manufacturer instructions using index values > 1.1 to define positive results .
john 's medical college research institute , bangalore , was used to validate testing and results were in agreement with 20 out of 20 samples .
hiv testing was performed using elisa following manufacturer instructions ( hivase 1 + 2 , general biologicals corporation , taiwan ) .
any woman who was found to be infected with hiv was provided medications for prevention of vertical transmission of hiv and referred to the antiretroviral therapy center in kr hospital .
all women were subsequently followed up after delivery up to a period of two years .
data were analyzed using stata 10.1 ( stata corporation , college station , tx ) .
pearson 's chi - square test adjusted to account for the cluster survey design was used to assess association of clinical characteristics and hsv-2 status using a p value cutoff of 0.1 for significance . to obtain odds ratios ,
data were modeled using logistic regression , with hsv-2 status as the binary outcome of interest .
in addition , relative risks were obtained using a generalized linear model with a log link function and binomial distribution .
a cluster survey design was used because pregnant women were geographically grouped into villages ; thus robust variance estimates adjusted within village correlation were obtained .
most of the pregnant women in the selected villages participated in the program . only 21 pregnant women in the community did not provide a blood sample , either because they had only recently done their antenatal investigations ( n = 8) or they declined to attend the medical clinic for personal reasons ( n = 13 ) . of the 487 ( 95.6% ) pregnant women
accounting for the cluster design of the sampling gives a prevalence of 6.7% ( 95% confidence interval ( ci ) : 4.49.0 ) .
of these 487 women , only one woman ( 0.2% ) tested positive for human immunodeficiency virus antibodies .
of the 487 women who provided a blood sample , 478 ( 98% ) agreed to be interviewed , which included all women who tested positive for hsv-2 .
the median age of the study population was 20 years , ranging from 15 to 33 years of age .
education level varied , with 13% of women reporting completion of less than one year of education , while 33% had completed 17 years , 36% had completed 810 years , and 18% had completed more than 10 years of school .
all but one woman participating in the study were married , with 34% of women married for one year or less , 40% married between 1 and 3 years , and only 26% married for longer than three years . about half the women in the study had children ( 52% ) .
the median household income per month was 3000 inr ( 1 usd = 45.9 inr ) , ranging from 0 to 40,000 inr per month , while only 2.7% ( 13/478 ) of participants reported regularly earning income themselves .
almost all of the participants ( 99.2% , 473/477 ) in the study population reported a single sex partner in their lifetime and 88.7% ( 422/476 ) of study participants reported never using a condom with their main sex partner . the majority of participants who tested positive for hsv-2 did not report symptoms commonly associated with hsv-2 ( table 2 ) .
vaginal sores were experienced by 4% of the women in the study , while 21% reported experiencing painful urination and 13% reported having abnormal vaginal discharge .
evidence of an association was found for the presence of vaginal sores ( p value = 0.08 ) , with 9% of hsv-2 seropositive women reporting vaginal sores compared to 3% of hsv-2 seronegative women .
painful urination ( p value = 0.26 ) and abnormal vaginal discharge ( p value = 0.49 ) were not associated with hsv-2 status .
using logistic regression , the unadjusted odds ratio was determined for each characteristic ( table 3 ) .
the only characteristic that showed evidence of affecting the odds of hsv-2 infection was if the sex partner ever traveled away from home , where participants whose partner ever traveled had 2.68 times the odds of being hsv-2 positive as compared to participants whose partner never traveled ( 95% ci : 1.146.34 ) .
a generalized linear model estimated the relative risk of hsv-2 among women whose partners ever traveled to be 2.44 ( 95% ci : 1.165.14 ) times greater than the probability of women whose husbands never traveled . to control for possible confounding , multivariable logistic regression was used to adjust for the participant 's age and husband 's education level . in this model ,
women whose main sex partner ever traveled away from home had 2.77 ( 95% ci : 1.206.41 ) times the odds of having a prevalent hsv-2 infection .
this study found hsv-2 prevalence of 6.7% among pregnant women attending mobile antenatal care clinics in 52 rural villages located in mysore taluk , karnataka , india . this is comparable to previously obtained measures of hsv-2 prevalence among other pregnant women in india [ 16 , 17 ] .
the 6.7% prevalence is lower than the three previously obtained estimates of hsv-2 prevalence in the state of karnataka , which ranged from 10.9 to 18.9% [ 2022 ] although these studies focused on nonpregnant populations .
almost all the women in this study reported having a single sex partner in their lifetime and one woman reported being unmarried .
it appears that the main route of hsv-2 transmission in this population is through sexual transmission from their spouses .
since very few married women consistently use a condom , the risk behavior of their husbands is a primary risk factor .
this information highlights the need to increase awareness and discuss risk behaviors among both men and women living in rural india . in our exploratory analysis , only having a husband who traveled away from home was significantly associated with an increased risk of hsv-2 infection .
misclassification should not have affected this finding since women would know how often their husbands traveled and there is no social stigma attached to this activity .
in addition , living in a small rural village may present limited opportunity for sex outside of marriage , so only husbands who travel may have access to other sex partners . furthermore , this may be the main entry point for hsv-2 into rural communities since sex workers are more common in urban areas and have been shown to have high rates of hsv-2 infection .
there is a debate about the accuracy of the focus diagnostics herpeselect hsv-2 igg elisa test kits used in this study .
some researchers have suggested that the cutoff value for a positive test should be raised from 1.1 to 3.0 or 3.5 when the test is used in low prevalence settings [ 24 , 25 ] . raising the cutoff value to 3.5
would have affected the study results since 14 of the 32 positive tests fell in the disputed range , decreasing the estimated prevalence from 6.6% to 4.7% .
additional hsv-2 studies should be conducted using a gold standard like western blot to confirm the results . in this study , the majority of hsv-2 positive individuals did not report experiencing symptoms caused by hsv-2 .
this is consistent with previous findings that hsv-2 is frequently asymptomatic or symptoms go unrecognized .
we did find an association between the presence of vaginal sores and hsv-2 ( p value = 0.08 ) .
however , only 9.4% of hsv-2 positive women reported experiencing vaginal sores , highlighting the challenge of diagnosing hsv-2 and the ability of hsv-2 to circulate undetected in a population .
information about spouses was obtained from participants who were likely to possess incomplete knowledge of their partners ' behaviors , resulting in misclassification .
though interviews were conducted in a private setting and women were guaranteed anonymity , it is possible that participants still feared disclosing personally or socially sensitive information .
this may also have resulted in misclassification that biased the results toward finding no association between certain risk behaviors .
this study was limited by a small sample size and a low prevalence of hsv-2 in the study population limiting the power of the study to detect associations between personal characteristics and hsv-2 .
associations found in other studies between older age and alcohol consumption and increased risk for hsv-2 infection were not found to be statistically significant in this study .
it is possible that with a larger sample size , associations would be found between additional factors and increased risk of hsv-2 infection .
this study provides needed information regarding the prevalence of hsv-2 among rural pregnant women in india and will serve as an important baseline measurement as investigators continue to monitor rates of hsv-2 in the future in rural india . | ### Summary:
: objectives . to assess the prevalence and determinants of herpes simplex virus type 2 ( hsv-2 ) infections among pregnant women attending mobile antenatal health clinic in rural villages in mysore taluk , india
. methods . between january and september 2009 ,
487 women from 52 villages participated in this study .
each participant consented to provide a blood sample for hsv-2 and hiv testing and underwent an interviewer - administered questionnaire .
results .
hsv-2 prevalence was 6.7% ( 95% confidence interval ( ci ) 4.49.0 ) , and one woman tested positive for hiv .
the median age of women was 20 years and 99% of women reported having a single lifetime sex partner .
women whose sex partner traveled away from home had 2.68 ( ci : 1.136.34 ) times the odds of being hsv-2 seropositive compared to women whose sex partner did not travel . having experienced genital lesions
was also associated with hsv-2 infection ( p value = 0.08 ) .
conclusion .
the 6.7% hsv-2 prevalence was similar to results obtained in studies among pregnant women in other parts of india .
it appeared that most women in this study contracted hsv-2 from their spouses and few regularly used condoms .
this finding highlights the need for public health policies to increase awareness and education about prevention methods among women and men living in rural india . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: nodular glomerulosclerosis is a pathological finding characterized by areas of marked mesangial expansion with accentuated glomerular nodularity on renal biopsy .
it was originally described by kimmelstiel and wilson as a pathognomonic feature of diabetic nephropathy .
however , nodules can also be seen in amyloidosis , light chain deposition disease ( lcdd ) , fibrillary and immunotactoid glomerulopathy , collagen type iii disease , nodular membranoproliferative glomerulonephritis , and takayasu 's arteritis .
if the presence of nodules is not associated with any of these disorders , it is labeled as being idiopathic .
the pathogenesis of this disorder is unclear and is known to occur in patients with hypertension , hypercholesterolemia , history of chronic smoking , chronic obstructive pulmonary disease with chronic hypoxemia , obesity , etc . despite the growing epidemic of metabolic syndrome , this entity
is grossly underreported in india . in this report , we present two cases of idiopathic nodular glomerulosclerosis , one in an obese and hypertensive male and the other in an underweight nonhypertensive female .
past history was insignificant except for an appendicectomy , 20 years back . on examination , he was normotensive , obese class ii ( body mass index [ bmi]-42 ) .
the evaluation revealed proteinuria ( 3.032 g / day ) , bland urinary sediment , and a serum creatinine of 1.3 mg / dl .
lipid profile was abnormal with high total cholesterol ( 213 mg / dl ) and low - density lipoprotein ( 153 mg / dl ) values .
immunological markers were negative , and complements were normal . in view of significant proteinuria ,
renal biopsy included 13 glomeruli , all enlarged in size and showed variably sized nodules , which were cellular and were periodic - acid - schiff ( pas ) and silver positive .
immunofluorescence was negative for igm , iga , igg , c3c , c1q , k , and . with the above findings being consistent with diabetic nephropathy , he was reevaluated , and diabetes mellitus was ruled out .
workup for other causes including amyloidosis , lcdd , and immune deposition diseases was negative .
electron microscopy ( em ) which revealed diffuse flattening of foot processes with marked widening and ill - defined lobularity of the mesangium without any electron dense deposits .
the negative features on em and immunofluorescence rule out other differentials of nodular glomerulosclerosis including monoclonal immunoglobulin deposition disease , fibrillary and immunotactoid glomerulonephritis , fibronectin glomerulopathy , and collagenofibrotic glomerulopathy [ figures 13 ] .
( a and b ) the glomeruli showing nodules which are cellular and variable in size with periodic - acid - schiff ( pas ) positivity ( c ) the nodules did not show matrix material ( masson trichrome , 100 ) .
( d ) the nodules were brightly positive on silver stains ( sm - pas , 100 ) the immunofluorescence panel included igm , igg , iga , c3 , c1q , and kappa and lambda light chains .
there was no evidence of linear or granular positivity along the basement membrane or mesangium for any of the immunoglobulins or complement or light chains absence of electron dense deposits in the mesangium , subepithelial or subendothelial region .
fibrils were also not identified with the above findings , the diagnosis of idiopathic nodular glomerulosclerosis was made , and the patient was discharged on telmisartan .
further follow - up of the patient at 3 monthly intervals revealed a progressive decline in proteinuria to < 1 g / day .
a 45-year - old female presented with myalgias , decreased appetite , and mild pedal edema of 15 days duration .
investigations revealed serum creatinine 8.9 mg / dl and 24 h urinary protein excretion 710 mg / day .
renal biopsy showed 12 glomeruli , all glomeruli were enlarged with nodules and were pas and silver positive .
immunofluorescence was negative for igm , iga , igg , c3c , c1q , k , and . em did not show any electron dense deposits and was suggestive of nodular glomerulosclerosis . her hba1c was 5% .
workup for other causes of nodular glomerulosclerosis such as amyloidosis , lcdd , and immune deposition diseases was negative .
lipid profile was normal except for a mildly decreased high - density lipoprotein level ( 38 mg / dl ) .
past history was insignificant except for an appendicectomy , 20 years back . on examination , he was normotensive , obese class ii ( body mass index [ bmi]-42 ) .
the evaluation revealed proteinuria ( 3.032 g / day ) , bland urinary sediment , and a serum creatinine of 1.3 mg / dl .
lipid profile was abnormal with high total cholesterol ( 213 mg / dl ) and low - density lipoprotein ( 153 mg / dl ) values .
immunological markers were negative , and complements were normal . in view of significant proteinuria ,
renal biopsy included 13 glomeruli , all enlarged in size and showed variably sized nodules , which were cellular and were periodic - acid - schiff ( pas ) and silver positive .
immunofluorescence was negative for igm , iga , igg , c3c , c1q , k , and . with the above findings being consistent with diabetic nephropathy , he was reevaluated , and diabetes mellitus was ruled out .
workup for other causes including amyloidosis , lcdd , and immune deposition diseases was negative .
electron microscopy ( em ) which revealed diffuse flattening of foot processes with marked widening and ill - defined lobularity of the mesangium without any electron dense deposits .
the negative features on em and immunofluorescence rule out other differentials of nodular glomerulosclerosis including monoclonal immunoglobulin deposition disease , fibrillary and immunotactoid glomerulonephritis , fibronectin glomerulopathy , and collagenofibrotic glomerulopathy [ figures 13 ] .
( a and b ) the glomeruli showing nodules which are cellular and variable in size with periodic - acid - schiff ( pas ) positivity ( c ) the nodules did not show matrix material ( masson trichrome , 100 ) .
( d ) the nodules were brightly positive on silver stains ( sm - pas , 100 ) the immunofluorescence panel included igm , igg , iga , c3 , c1q , and kappa and lambda light chains .
there was no evidence of linear or granular positivity along the basement membrane or mesangium for any of the immunoglobulins or complement or light chains absence of electron dense deposits in the mesangium , subepithelial or subendothelial region .
fibrils were also not identified with the above findings , the diagnosis of idiopathic nodular glomerulosclerosis was made , and the patient was discharged on telmisartan .
further follow - up of the patient at 3 monthly intervals revealed a progressive decline in proteinuria to < 1 g / day .
a 45-year - old female presented with myalgias , decreased appetite , and mild pedal edema of 15 days duration . she was moderately built and underweight .
investigations revealed serum creatinine 8.9 mg / dl and 24 h urinary protein excretion 710 mg / day .
renal biopsy showed 12 glomeruli , all glomeruli were enlarged with nodules and were pas and silver positive .
immunofluorescence was negative for igm , iga , igg , c3c , c1q , k , and . em did not show any electron dense deposits and was suggestive of nodular glomerulosclerosis .
workup for other causes of nodular glomerulosclerosis such as amyloidosis , lcdd , and immune deposition diseases was negative .
lipid profile was normal except for a mildly decreased high - density lipoprotein level ( 38 mg / dl ) .
less than 50 cases of idiopathic nodular glomerulosclerosis have been reported in the literature and none from india .
markowitz et al . , in 2002 have published the largest series of this entity including 23 cases .
this could be because of the nonavailabilty of advanced diagnostics like em in the past .
idiopathic nodular glomerulosclerosis was described previously as diabetic like nodular glomerular lesions occurring in a nondiabetic patient .
baradhi et al . , in 2012 reported a case of diabetic nephropathy in a nondiabetic smoker in which they have detailed about various causes of nodular glomerulosclerosis including idiopathic nodular glomerulosclerosis .
this rare disease entity was thought to be strongly associated with long - standing hypertension , chronic smoking , hypercholesterolemia , etc .
a study from china reported the clinicopathological profile of 20 cases of idiopathic nodular glomerulosclerosis .
male preponderance was noted , and overweight ( in 95% patients ) , cigarette smoking ( in 85% ) , and hypertension ( in 90% ) were the risk factors strongly associated .
various hypotheses postulated explaining the occurrence of nodular glomerulosclerosis in the setting of hypertension , hypercholesterolemia , smoking , and obesity include : increased sensitivity to a nondiabetic range of blood glucose levels resulting in exaggerated glomerulovascular response .
cigarette smoke contains free radicals that induce oxidative stress , increasing the glomerular extracellular matrix ( ecm ) production by activating transforming growth factor and insulin - like growth factor prosclerotic signaling pathways .
tobacco smoke also contains reactive glycation products which can react rapidly with proteins to form advanced glycation end product .
chronic hypoxia activates the sympathetic nervous system in turn stimulating renin - angiotensin system and promoting ecm production .
though long - term hypertension and smoking were considered causative in the pathogenesis of this disease entity , in our first patient , hypertension was only of a short duration which was well - controlled with a single drug , and he was not a smoker , and our second patient was nonhypertensive and never smoked . apart from this ,
our patient had obesity which has not been described solely as a risk factor in association with idiopathic nodular glomerulosclerosis in literature .
we attribute our finding of idiopathic nodular glomerulosclerosis to obesity , a component of metabolic syndrome , which might add to hyperfiltration injury in our first patient .
we advised our patient weight reduction along with arb ( telmisartan ) which would otherwise help in hypertension control and reduce hyperfiltration injury .
our second patient is neither obese nor hypertensive but has a severe form of the disease with dialysis dependence .
the above findings from the two cases show that idiopathic nodular glomerulosclerosis might not be single disease entity and needs further investigation into its etiopathogenesis .
idiopathic nodular glomerulosclerosis should be suspected in any nondiabetic with a histopathological description of diabetic nodular glomerulosclerosis after ruling out other causes of nodular glomerulosclerosis and em is a must in these cases .
| ### Summary:
: nodular glomerulosclerosis , a pathological finding characterized by areas of marked mesangial expansion with accentuated glomerular nodularity can be seen in a number of conditions including diabetic nephropathy , amyloidosis , light chain deposition disease , fibrillary and immunotactoid glomerulopathy , collagen type iii disease , nodular membranoproliferative glomerulonephritis , and takayasu 's arteritis .
idiopathic nodular glomerulosclerosis is a diagnosis of exclusion and is reported in patients with hypertension , smoking , chronic obstructive pulmonary disease , obesity , metabolic syndrome , etc .
we report two cases of idiopathic nodular glomerulosclerosis , one in obese hypertensive male and the other in nonhypertensive , nonobese female patient . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: india has approximately 2.4 millions of people living with hiv and two thirds live in rural areas .
however , most of the studies on hiv in india have been performed in research centres or tertiary hospitals situated in urban areas .
studies in rural areas are difficult to perform due to isolation , poor communications , poverty and lack of institutions interested on doing research in rural regions . in this study , we describe risk factors associated with hiv infection in patients who were tested for hiv in a rural hospital of india .
the findings of this study provide new information for understanding the hiv epidemic in rural india . knowing the risk factors associated with hiv is essential for designing effective health programs aimed to achieve early diagnosis of hiv and prevent the transmission in the population .
with 2.4 millions of people living with hiv , india carries the largest burden of hiv in asia and is the third country of the world in terms of hiv infected people . except for some northern states with high rates of injection drug use in the population ,
preventive measures of the government of india for fighting against the spread of hiv have been based on the assumption that the primary drivers of the epidemic are high risk groups , commercial sex workers and men who have sex with men , who transmit the virus to a male bridge population .
this bridge population , mainly migrants and truckers , extend the transmission to their female sexual partner and from them to their children .
preventive interventions focused on high risk groups have attained impressive results reducing the incidence of hiv .
however , new data are suggesting that the hiv epidemic in india is evolving into a more generalized distribution in the population . in order to keep the current decline of hiv incidence in india
, we need a better understanding of the mechanisms of transmission and risk factors associated with hiv in the general population .
although it is estimated that 67% of hiv infected people in india are rural residents , risk factors associated with hiv infection in rural areas are not well known because most of the studies on hiv in india have been performed by institutions located in urban areas and there has been an underrepresentation of the rural population in previous epidemiological investigations .
hiv infected patients who do not know to be infected consult health workers because of their medical problems .
this is an optimal situation for performing a rapid hiv test and , if positive , for giving a proper counseling to the patient in order to prevent hiv transmission to others .
the aim of this study is to investigate socio - demographic risk factors associated with hiv infection in a population of patients who were tested for hiv in a rural area of india .
the hospital is situated in a rural area of anantapur district in andhra pradesh , which is the state with highest burden of hiv in india .
patients do not pay for medical consultations and the cost of medicines is partially waived to people belonging to scheduled castes ( sc ) and scheduled tribes ( st ) . sc community is the lowest caste in the traditional hindu caste hierarchy and , therefore , suffers social and economic exclusion and disadvantage .
st community is generally geographically isolated with limited economic and social contact with the rest of the population .
both sc and st communities have significant higher levels of poverty than other non - scheduled communities . other backward castes ( obc ) are a collection of intermediate castes that were considered low in the traditional caste hierarchy , but above sc .
other castes ( oc ) , also called general class or forward castes , were considered above previous mentioned castes in the traditional hindu hierarchy and do not qualify for any of the current positive discrimination schemes operated by the government of india . between august 2 2007 and december 31 2010 , patients aged above 15 years who attended the outpatient clinics of the hospital and were tested for hiv infection as part of their routine care were counseled before and after the test and socio - demographic details were systematically collected . following who recommendations for diagnosing hiv infection ,
if the test was reactive , two other hiv assays were performed for confirmation of hiv infection .
logistic regression was used for the multivariable analysis of factors associated with having hiv infection using stata statistical software ( stata corporation , rel .
several interactions were found between gender and communities in the initial logistic regression model so the models were run separately by these variables .
the study was approved by the ethical committee of the institutional review board of rural development trust .
the study included 6406 patients who were tested for hiv during the period of the study .
st and sc communities had lower level of education and higher proportion of agricultural workers than other communities .
multivariable analysis of risk factors associated with hiv infection separated by gender and community is presented in table 2 . as a predictor of hiv infection , age was more important for males than for females .
it was observed higher odds ratios in people aged 25 to 45 years in males from all communities .
working in a field not related to agriculture was significantly related to having hiv in sc and in males from st . in general , people with lower levels of education had higher odds ratios for hiv infection .
being single was a protective factor for having hiv infection in all communities except in males from oc , although this was not statistically significant . by far , the most important factor associated with hiv infection in women was being a widow . in all cases ,
compared to non - widowed women , odds ratios for hiv infection of widows aged 15 - 25 years , 25 - 35 years , 35 - 45 years and above 45 years were 7.09 ( 95% confidence interval , 2.40 - 20.94 ) , 6.60 ( 95% confidence interval , 3.66 - 11.91 ) , 6.62 ( 95% confidence interval , 3.82 - 11.47 ) and 2.03 ( 95% confidence interval , 1.07 - 3.86 ) respectively in multivariable logistic regression models adjusted by community , occupation and education .
our results show that widows who seek medical advice in a rural area with high hiv prevalence have a high risk of being hiv infected and the risk is inversely related to the age of the widow .
female widowhood has been recognized as one of the most important risk factors for hiv infection in india in at least two previous population - based studies .
the most important route of hiv transmission in india is through sexual contacts and more than 90% of infected women acquire the infection from their husbands .
it has been observed that hiv is an important cause of death among young men in indian states with higher prevalence of hiv .
the reduction of the hiv prevalence in these states was followed by a reduction of all - cause mortality in men aged 25 - 34 years .
since husbands acquire hiv earlier , they are likely to die before their wives , even if both members of the couple are infected . in many cases ,
these hiv positive widows are left in deplorable situations due to illiteracy and lack of emotional and economical support .
it has been observed that these poor conditions induce them to engage in sexual activity in exchange for emotional and financial help and , therefore , continuing the spread of the disease .
specific programs focused on hiv screening and providing economical and psychological support of hiv positive widows are urgently needed in india . as seen in other cross sectional studies ,
hiv infection was more common in young adults in both sexes but age was more important for men than for women .
people from sc and males from st who worked in the agriculture sector had lower risk of having a positive hiv test , perhaps because they are less likely to have high risk sexual contacts than men whose job involves higher regular mobility .
previous studies have shown an association between lower education level and hiv infection . however , in our study the highest risk for hiv infection was observed in those who only completed primary education . in general , these patients abandoned the school for working .
new studies on the sexual behavior , sexual vulnerability and migration patterns in this group may clarify this finding .
hiv test was requested when the treating clinician suspected that the patient could be hiv infected .
this explains the high hiv prevalence found in our study , which should not extrapolated to the general population .
population based well designed studies are needed to confirm our findings , although these types of studies are expensive and difficult to perform in rural areas .
moreover , we do not have information about the hiv status of the husbands of the hiv infected widows
. we can not know whether these widows acquired hiv from their husbands or after their husbands death . in conclusion ,
the findings of this study indicate the complexity of the hiv epidemic in india . there were important differences in hiv associated risk factors between men and women and between the different indian communities .
young widows who seek medical advice in rural areas of india with high prevalence of hiv have high risk of being hiv infected .
we also found that lower education levels and working in a field not related to agriculture were factors associated with higher risk of hiv infection in this rural setting .
the results of this study can help to design health programs aimed to achieve early diagnosis of hiv in rural health facilities of indian states with high hiv prevalence . | ### Summary:
: despite the fact that two thirds of hiv infected people in india are rural residents , risk factors associated with hiv infection in rural areas are not well known .
in this study we have collected socio - demographic data of 6406 patients who were tested for hiv infection in a rural hospital of india and we have investigated risk factors associated with hiv . in women the most important risk factor was being a widow and the risk was higher in younger than in older widows .
other variables found to be associated with hiv infection were age between 25 and 45 years in men , low education level ( especially those who only completed primary education ) and working in a field not related to agriculture in scheduled castes and men from scheduled tribes .
the results of this study express the need for hiv screening of widows who live in rural areas of indian states with high hiv prevalence . |
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: since vision loss from glaucoma can not be recovered , improved screening and detection methods for the angle closure glaucoma are essential to preserve vision and maintain a good quality of life .
although glaucoma commonly progresses to blindness over many years , acute angle closure can result in permanent blindness in a matter of hours .
studies suggest that glaucomatous optic neuropathology can be prevented when effective prophylactic treatment such as laser peripheral iridotomy is performed at an early and appropriate time for the eyes with anatomically narrow angles .
angle closure glaucoma is characterized by obstruction of aqueous fluid drainage through the trabecular meshwork from the eye 's anterior chamber .
a wide unobstructed iridocorneal angle allows sufficient drainage of aqueous humor , whereas a narrow angle may impede the drainage system and leave the patient susceptible to angle closure glaucoma .
the imaging of angle between the iris and the cornea is the key for open angle and closed angle glaucoma diagnosis
gonioscopy , is considered the gold standard technique to examine the iridocorneal angle , but it is subjective and dependent on the operator .
oct is a high resolution , rapid , and noninvasive screening tool for angle closure glaucoma and its technology has evolved rapidly from time - domain to spectral - domain .
swept source oct ( casia ss-1000 ) is a newly developed novel imaging technology which provides a detailed examination of the structures of anterior chamber ( ac ) .
it is a fourier - domain system and is designed specifically for imaging the anterior segment . with a substantial improvement in scan speed ( 30,000 a - scans per second ) , the anterior chamber angles can be imaged in 128 cross - sections ( each with 512 a - scans ) 360 degree around the anterior segment in 1.2 seconds .
high - definition ss - oct ( ss - oct ) imaging has the potential to become an important tool for the assessment of the anterior chamber angle and detection of angle closure [ 4 , 5 ] .
anterior segment ss - oct imaging has significantly altered the diagnosis and evaluation of acg .
the information gained with new imaging modalities provides clinicians with both qualitative and quantitative information about anatomical structure of the anterior chamber .
hu et al . compared gonioscopy with visante and cirrus optical coherence tomography ( oct ) for identifying angle structures and the presence of angle closure in patients with glaucoma .
several techniques to assess the anterior chamber are based on manual or automatic detection of some landmarks such as scleral spur ( ss ) and schwalbe 's line ( sl ) [ 8 , 9 ] .
however , the existing methods use a single distance or area , for example , aod500 , tisa500 , and aodsl , for measurement of iridocorneal angle , without consideration of the whole angle profile .
cheung et al . showed that an irregular iris surface made the aodsl very inaccurate .
our previous study measured two new parameters , maod and atsl , based on the continuous aod to assess the anterior chamber angle .
these two new parameters tried to overcome the limitations in the single measurement of aod when the iris surface is irregular and the angle is more occludable .
the iris curvature of anterior segment oct ( as - oct ) is usually calculated by drawing a line from the most peripheral to the most central points of the iris pigment epithelium , and then a perpendicular line is extended from this line to the iris pigment epithelium at the point of the greatest convexity .
however , the iris pigment epithelium can not be exactly detected , only the stoma .
the segmentation of the iris lower boundary is challenging due to the low contrast in this region .
the nature of the angle dynamics which has not been considered yet in the previous studies , still involved in different forms of angle closure or open angle glaucoma .
hence , we propose to measure the iris curvature denoted by hiris from the extracted iris image . besides
, we assume that the iridocorneal angle is the irregular shape and the complexity or changes of the iridocorneal angle can be measured quantitatively and qualitatively with shape descriptors .
the shape analysis might give more freedom in computation and is less sensitive to the accurate detection of the landmarks the scleral spur ( ss ) and schwalbe 's line ( sl ) . using this approach ,
the shape analysis may be successfully applied both quantitatively and objectively to characterize angle shape of anterior chamber of ss - oct images .
the complex and erratic shape description in terms of self - similarity was introduced by mandelbrot .
the concept of fractal dimension ( fd ) is useful in the measurement , analysis , and classification of shape and texture .
the fractal dimension , therefore , might serve as a sensitive descriptor of the iridocorneal angle shape .
fractals provide a new field for characterization of irregularity and complexity , yet self - similar structures in nature . however , although fd has been used extensively in characterizing self - affinity in various kinds of biomedical research [ 13 , 14 ] , little attention has been paid in automated glaucoma subtype classification using the feasibility of fractal and multifractal theory on retinal nerve fiber layer ( rnfl ) and optic disc .
the measurement of moment invariants like the triangularity ( ti ) and ellipticity ( ei ) was successfully used in several applications like the classification of mammographic masses and lung field boundaries .
both shape analyses are a translation , rotation , and scale of the object and general affine transformations .
therefore , the paper proposes a new strategy to analyze the iridocorneal angle by morphological shape analysis as well as biometric angle parameters . in this paper
, we present an automatic angle closure glaucoma detection system based on machine learning and image analysis for the estimation of quantitative parameters to classify ss - oct images into two classes : open angle and angle closure glaucoma .
we propose new strategies of feature extraction methods : ( 1 ) based on measurement of biometric parameters and ( 2 ) based on the shape analysis of iridocorneal angle to capture much more information .
section 2 describes the overview of the algorithm for preprocessing , feature extractions , and classification method of angle closure glaucoma .
it mainly consists of four steps : preprocessing , segmentation of anterior chamber , anterior chamber angle analysis for feature extractions , and classification of angle closure and open angle glaucoma .
this section starts by defining the notation that will be used throughout the paper and figure 2 shows the region of interest for iridocorneal angle analysis .
firstly , the original image denoted by i(x , y ) is preprocessed to remove the vertical saturation artifacts as in and the processed image is denoted by i^(x , y ) , where ( x , y)[1 , m][1 , n ] are the pixels coordinates and m n is the size of the image ; then i^(x , y ) is segmented to detect the cornea , the iris , and the anterior chamber .
the lower boundaries of the cornea ee and inner boundary of the iris ei are detected using the same approach as the method in , and the iris image denoted by ii(x , y ) is extracted .
the six features are extracted to quantify the anterior chamber ; the anterior chamber assessment parameters are maod , atsl , the mean curvature of the iris hiris , and shape descriptors fd , ti , and ei .
the definitions of the variables used in this paper are listed here : original gray scale image : i(x , y ) , where ( x , y)[1 , m][1 , n];the preprocessed image : i^(x , y ) , where ( x , y)[1 , m][1 , n];the segmented corneal endothelium , the anterior surface of the iris , and anterior chamber mask in i(x , y ) : ee , ei , and mac;the extracted iris image : ii(x , y);automatically detected schwalbe 's line : sl;angle opening distance : aod;mean of the continuous measurement of the angle opening distance : maod;area of the trapezoidal profile of the iridocorneal angle centered at schwalbe 's line : atsl;mean of the iris curvature from the extracted iris image ; hiris;the extracted iridocorneal angle image : iira(x , y ) , where ( x , y)[1,m][1,n];complex shape descriptor to quantify the complexity or changes of iridocorneal angle : fractal dimension ( fd);ellipticity moment shape descriptor : ei;triangularity moment shape descriptor : ti .
original gray scale image : i(x , y ) , where ( x , y)[1 , m][1 , n ] ; the preprocessed image : i^(x , y ) , where ( x , y)[1 , m][1 , n ] ; the segmented corneal endothelium , the anterior surface of the iris , and anterior chamber mask in i(x , y ) : ee , ei , and mac ; the extracted iris image : ii(x , y ) ; automatically detected schwalbe 's line : sl ; angle opening distance : aod ; mean of the continuous measurement of the angle opening distance : maod ; area of the trapezoidal profile of the iridocorneal angle centered at schwalbe 's line : atsl ; mean of the iris curvature from the extracted iris image ; hiris ; the extracted iridocorneal angle image : iira(x , y ) , where ( x , y)[1,m][1,n ] ; complex shape descriptor to quantify the complexity or changes of iridocorneal angle : fractal dimension ( fd ) ; ellipticity moment shape descriptor : ei ; triangularity moment shape descriptor : ti .
it is observed that some ss - oct images contain vertical saturation artifacts , which hinder the accurate interpretation of the image if thresholding and component labeling are used for the segmentation .
hence , reducing and removing the artifacts are performed prior to the segmentation step . as illustrated in figure 3(a ) , the vertical saturation artifacts are marked by sudden increases in intensity as compared to surrounding area and are caused by the saturation of intensity due to the strong reflection in certain locations .
therefore , we detected such artifacts by searching for abrupt changes in the average intensity of each column as shown in figure 3(b ) .
after removing the vertical saturation artifacts , the segmentation was performed in the ss - oct images .
the method consists of segmenting the anterior chamber , the cornea , and the iris and extracting their edges .
the anterior chamber region , the lower cornea boundary , and the upper iris boundary are extracted by image segmentation method .
this section describes the analysis of aca for the extraction of six features by the biometric parameter measurement and shape analysis .
the biometric parameters , previously proposed in , from the iridocorneal angle based on the continuous measurement of aod are quantified as follows.maod : the average of continuous serial aod measured every 25 m away from the sl till 500 m in both directions ( anterior and posterior to / from schwalbe 's line ) as shown in figure 4(a).atsl : the trapezoidal area of iridocorneal angle bounded by the angle recess , aod_psl line , corneal endothelium , and anterior surface of the iris as shown in figure 4(a).hiris : the mean iris curvature measured from the whole iris image as shown in figure 4(b ) .
maod : the average of continuous serial aod measured every 25 m away from the sl till 500 m in both directions ( anterior and posterior to / from schwalbe 's line ) as shown in figure 4(a ) .
atsl : the trapezoidal area of iridocorneal angle bounded by the angle recess , aod_psl line , corneal endothelium , and anterior surface of the iris as shown in figure 4(a ) .
hiris : the mean iris curvature measured from the whole iris image as shown in figure 4(b ) . after calculating the biometric parameters , we performed anterior chamber shape analysis on the selected region of iridocorneal angle image as shown in figure 5 .
we utilized the fractal complex shape descriptor on the iridocorneal angle image denoted by iira(x , y ) , where ( x , y)[1,m][1,n ] are the pixels coordinates and mn is the size of the extracted angle image .
moment shape descriptors such as the triangularity and ellipticity are used to compare the performance of fractal dimension analysis . the angle structure configuration is then quantified by the following three features : complex shape descriptor to quantify the complexity or changes of iridocorneal angle , fractal dimension ( fd);ellipticity moment shape descriptor ( ei);triangularity moment shape descriptor ( ti ) .
complex shape descriptor to quantify the complexity or changes of iridocorneal angle , fractal dimension ( fd ) ; ellipticity moment shape descriptor ( ei ) ; triangularity moment shape descriptor ( ti ) .
the ability of each feature extraction method to separate open angle and angle closure glaucoma is quantified by the fuzzy k - nearest neighbour classifier .
the basis of the fuzzy k - nn algorithm is to assign membership as a function of the vector 's distance from its k - nearest neighbors and those neighbors ' memberships in the possible classes .
the singaporean chinese population study by the singapore national eye centre recruited 148 subjects ( 90 females and 45 males ) with average age of 59.48 8.97 .
all subjects underwent a standard examination of dark room gonioscopy and the anterior segment imaging by ss - oct on the same day .
the casia ss-1000 oct ( tomey , nagoya , japan ) was used as the imaging modality to visualize the anterior segment of the eye .
we used the 2d angle high - definition ( hd ) mode of ss - oct imaging with the ( 8 mm , 8 mm ) scan dimension . in the hd scan mode , the identification of both the sl and ss was possible in over 98% of ss - oct images .
the aca was graded using the modified shaffer grading system in each ss - oct image .
the doctor examined four different quadrants of the eye , namely , inferior , superior , nasal , and temporal ( i , s , n , and t ) scanning .
a subset of 29 subjects ( 23.4% ) was imaged bilaterally to assess the differences between eyes .
we selected the images with two criteria : ( 1 ) sl could be identified automatically and ( 2 ) only one image from the four scans of each eye , for less bias for classifier .
so , in total 264 ss - oct hd images in which sl could be seen were selected from the dataset for further analysis .
they were 132 nasal scan images , 70 temporal scan images , 29 superior scan images , and 33 inferior scan images .
using gonioscopic shaffer grading as the gold standard , 135 images with closed angle ( 1.131 0.72 grade ) and 129 images with open angle ( 3.321 0.469 grade ) were evaluated for the analysis .
the vertical saturation artifacts were presented in 77 images ( ~46% ) out of 264 images in the dataset on various regions of image .
so , it is necessary to perform artifact removal for affected images prior to image segmentation .
figure 6 shows the segmentation results of with and without artifact removal in ss - oct image . from the results
as shown in figure 6 , we found that the preprocessing steps relatively improved the segmentation of the anterior chamber region .
figure 7(a ) shows the segmentation results of the anterior chamber , the upper cornea , the lower cornea , and the inner boundary of the iris .
the extracted iris image is shown in figure 7(b ) which yields the iris curvature of 0.294 .
figure 7(c ) shows an example of the resulting angle profile consisting of 40 continuous aod centered on sl which reveals 0.262 mm for maod and 0.276 mm for atsl , respectively .
then , we find the region of interest for the fractal dimension and the moment shape analysis as shown in figure 7(d ) .
the results of the triangularity and the ellipticity moment shape analysis are 0.899 and 0.165 , respectively , as shown in figure 7(e ) .
figure 7(f ) shows the fractal image of the region of interest of figure 7(d ) and its estimated average fd is 1.862 .
the comparison of the iridocorneal angle features between open angle and angle closure glaucoma ss - oct images using gonioscopic grading as a reference is illustrated in table 1 .
the fractal dimensions of open and closed angle are 1.87 and 1.84 , respectively , as shown in table 1 .
the results of fractal dimension depend slightly on the specific images of open angle and angle closure glaucoma
. all the features of closed angle ss - oct images are smaller than those of the open angle ss - oct images .
the coefficients of variance ( covs ) of fd are smaller in both open and closed angle images .
the covs of hiris are the largest in both open and closed angle ss - oct images .
so , hiris results are considered to be high variance and do not necessarily correspond to closed and open angle images in this study .
figure 8 shows the scatter plot of fd , maod , and atsl features for both open angle and closed angle ss - oct images .
after the feature vectors were computed , training , cross - validation , and testing sets were formed by 1476 vectors ( 264 images 6 features ) : 3 biometric features ( maod , atsl , and hiris ) and 3 shape descriptors ( fd , ti , and ei ) .
then , we perform the feature selections from all features for improving classification accuracy or decreasing the size of the structure without significantly decreasing classification accuracy of the classifier which is built using only the selected features . reducing the number of irrelevant / redundant features
drastically reduces the running time of a learning algorithm and yields a more general concept .
this helps in getting a better insight into the underlying concept of a real - world classification problem .
feature selection methods try to pick a subset of features that are relevant to the target concept and these features are used as the input of classifiers .
the association between the gonioscopic grading and the measured iridocorneal angle features was evaluated for feature selection using spearman correlation coefficient ( ) .
there is a high correlation between fd , maod , and atsl and gonioscopic grading as shown in table 2 .
so , we grouped those features for classification and compared the consistency with other separate features . in the system , these features were firstly normalized to mean zero and variance of one to improve the classification process .
then , the classification was performed based on the normalized features by fuzzy k - nearest neighbor classifier ( fknn ) .
the performance of the fknn was evaluated by comparison with widely used machine learning algorithms , namely , linear discriminant analysis ( lda ) , k - nearest neighbour ( knn ) , and support vector machines ( svm ) , to verify the effectiveness of the proposed model .
the classification was performed on the 5-fold cross - validation ( 5-fold cv ) of various combinations of features .
to verify the effectiveness of the proposed fknn classifier , we firstly find the relationship between the classification performance and the fuzzy strength parameter m which varies from 1 to 2 , with the step size of 0.1 .
it can be observed that the accuracy was achieved between 93% and 99% and auc value fluctuates between 87% and 99% based on the feature groups as shown in figures 9(a ) and 9(b ) .
it reveals that fuzzy strength parameter m has a big impact on the performance of fknn classifier .
the average 5-fold cv accuracy and the corresponding standard deviation of fknn are shown in table 3 .
the classification using fd , maod , and atsl features group yields the best performance accuracy 99.11% 0.76% and auc 0.98 0.012 .
these findings suggest that the proposed method is highly promising in providing accurate diagnosis tools for acg and will make a greater clinical impact if the study can be done on a larger image database .
we also evaluated the performance of fuzzy knn by using only three features ( fd , maod , and atsl ) with other classification methods ( lda , knn , and svm ) .
svm slightly outperforms lda with an accuracy of 83.26% 4.74% ( 87.78% 7.92% sensitivity and 68.4% 9.29% specificity ) and an auc of 0.78 0.03 was reached .
knn was found to outperform lda as well as svm with an accuracy of 85.80% 5.16% ( 90.10% 5.77% sensitivity and 71.82% 5.41% specificity ) and 0.80 0.04 auc value .
the best classification performance was provided by the fuzzy knn classifier with fuzzy membership of the samples ( ~18% ) better than other classifers ( lda , knn , and svm ) as in table 4 .
additionally , fknn has been shown to be an efficient and robust classification method to diagnose angle closure glaucoma in ss - oct images .
the proposed fractal shape descriptor also showed better accuracy in comparison to the moment shape descriptor method .
the moment shape descriptor method is shown in the literature as an efficient technique to obtain shape descriptors . however , the results presented in this work suggest that the fractal analysis is a worthy option for providing shape descriptors for classification tasks , as it is invariant to rotation , translation , and scale . besides , our fractal dimension analysis is performed for each pixel on gray level images that can capture more detailed information of the angle structure .
in addition , that fractal shape analysis gives more freedom in computation and is less sensitive to the accurate detection of the landmarks the scleral spur ( ss ) and schwalbe 's line ( sl ) . moreover , our classification results are comparable to those of xu et al . .
they achieved the classification accuracies of 0.921 0.036 auc and 84.0% 5.7% balanced accuracy at an 85% specificity using histogram equalized pixel ( hep ) values and svm classification in oct images .
we also observed a significant advantage in terms of classification performance of using the fuzzy knn algorithms in glaucoma diagnosis . in summary
, the proposed framework has been shown to be a useful tool in screening for acg . while our system can provide useful classification and support to the medical experts through identification of features , human intervention to exploit the extracted knowledge
we believe that our findings in this study can serve as a basic grading system for angle closure glaucoma diagnosis in the future .
we evaluated several techniques for extracting useful information from ss - oct images such as traditional biometric parameter measurement and complex shape descriptors using fractal dimension analysis .
the experimental results demonstrated that the proposed technique which is the combination of biometric parameter , fractal dimension analysis , and classification by fuzzy knn method achieved great accuracy in the classification of the open and closed angle glaucoma images with an accuracy rate of 99.11% 0.76% and 0.98 0.012 auc value .
the performance of the fully automatic system presented here is comparable to medical experts in detecting glaucomatous eyes and could argue clinicians ' diagnosis of angle closure glaucoma . | ### Summary:
: optical coherence tomography is a high resolution , rapid , and noninvasive diagnostic tool for angle closure glaucoma . in this paper
, we present a new strategy for the classification of the angle closure glaucoma using morphological shape analysis of the iridocorneal angle .
the angle structure configuration is quantified by the following six features : ( 1 ) mean of the continuous measurement of the angle opening distance ; ( 2 ) area of the trapezoidal profile of the iridocorneal angle centered at schwalbe 's line ; ( 3 ) mean of the iris curvature from the extracted iris image ; ( 4 ) complex shape descriptor , fractal dimension , to quantify the complexity , or changes of iridocorneal angle ; ( 5 ) ellipticity moment shape descriptor ; and ( 6 ) triangularity moment shape descriptor .
then , the fuzzy k nearest neighbor ( fknn ) classifier is utilized for classification of angle closure glaucoma .
two hundred and sixty - four swept source optical coherence tomography ( ss - oct ) images from 148 patients were analyzed in this study . from the experimental results ,
the fknn reveals the best classification accuracy ( 99.11 0.76% ) and auc ( 0.98 0.012 ) with the combination of fractal dimension and biometric parameters .
it showed that the proposed approach has promising potential to become a computer aided diagnostic tool for angle closure glaucoma ( acg ) disease . |
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: given the increasing size of public databases storing high - throughput gene expression experiments , namely geo ( 1 ) and arrayexpress ( 2 ) , the problem of specific expression data retrieval is becoming a serious challenge , mainly related to two major annotation issues : a precise and up - to - date link between the numerical results of the expression measurements and the name of the corresponding transcripts , the tag - to - gene mapping , and second , a correct and universal biomedical annotation of the samples and experiments , or experiments ' annotation . due to the rapid evolution of genomes ' annotations , the tag - to - gene mapping needs to be refreshed continuously to maintain its usefulness .
on the other hand , the experiments ' annotation , often based on a free - text variable description , needs to be standardized once via a common biological ontology . to meet these annotation standards for public expression data
, we developed the cleanex ( 3 ) tags - to - gene re - annotation and biomedical integration system , which allows to keep an up - to - date gene annotation for expression data , and which provides a standard biomedical annotation of human and mouse public expression datasets , based on the medical subjects headings ( mesh http://www.nlm.nih.gov/mesh/ ) terms .
the cleanex database now contains nearly one thousand of human and mouse datasets , most of them were uploaded from the geo database and biologically re - annotated by cleanex .
the upload rhythm depends on the post - processing needed for each dataset . during last year
, a mean of 15 datasets per month have been integrated in the cleanex re - annotated data .
the first choice for data upload goes to cancer data , in particular breast and lung cancer data , as these are the main research topics at the swiss institute for experimental research .
it is estimated that at least 60% of all publicly available data meeting these criteria are currently available via cleanex .
regarding tags - to - gene mapping , cleanex newly provides a mapping for sage ( 4 ) or mpss ( 5 ) tags .
the cleanex affymetrix ( http://www.affymetrix.com ) mapping files are now also accessible by an external affymetrix probes viewer called splicy ( http://host10.bioinfo3.ifom-ieo-campus.it/splicy/ ) ( 6 ) .
major improvement in the web interfaces has lead to an efficient mechanism for both data retrieval and analysis .
the expression measurements can be searched via gene names , as well as via the biomedical mesh terms .
specific data can then be analyzed on the cleanex server or downloaded as a matrix - formatted text file .
the cleanex data analysis system is now coupled with the signal search analysis ( ssa ) server ( http://www.isrec.isb-sib.ch/ssa/ ) ( 7 ) , and a promoter sequence retrieval system .
amongst the three official gene expression repositories selected by the miame consortium , two are heavily populated and offer user - friendly data access interfaces , namely arrayexpress ( http://www.ebi.ac.uk/microarray-as/ae/ ) and geo ( http://www.ncbi.nlm.nih.gov/geo/ ) .
arrayexpress is the second in terms of data quantity , while geo has become the major repository and contains now nearly 10 000 experiments , or series , generated with very heterogeneous experimental procedures . though the first aim of these two databases was to serve as public expression data archives and distribution centers , they both evolved considerably beyond this scope and offer a number of tools to query an integrated database of expression profiles .
geo provides , via the ncbi entrez ( http://www.ncbi.nlm.nih.gov/ ) system or directly via dataset identifiers , some interesting data retrieval tools , going from the single - gene expression retrieval with expression graphs to complex queries allowing data clustering . however , clustering is possible only for a subset of annotated geo series ( gse ) , called datasets ( gds ) , which have been manually annotated and classified according to specific experimental criteria .
the data retrieval and analysis is limited to a single series / dataset at a time .
arrayexpress offers a search system which retrieves all the annotated experiments for one gene at once .
the arrayexpress team has also set up its own ontology ( ontology efo : http://www.ebi.ac.uk/ontology-lookup/browse.do?ontname=efo ) ( 8) , based on the mged ( http://www.mged.org/ ) ontology work group ( owg http://mged.sourceforge.net/ontologies/index.php ) proposals , as a trial to classify the data via a list of standard terms .
this ontology contains biomedical terms , as well as terms associated with gene expression profiling protocols .
the expression data query interface , however , is not yet linked to the tree - like structure of this ontology . despite the emergence of biomedical ontologies ( 9 ) , the expression experiments annotation is still quite inconsistent , often using different synonyms for the same concept .
this heterogeneity problem has already been faced for the numerical expression values . while the numerical values , though not standardized across different platforms , are now stored in well - defined formats that make retrieval and downstream analysis easy the usual format for experimental annotation is stil based on a free text description .
in the following part we will describe the methods developed in the cleanex database to handle the two annotation issues mentioned above , namely the gene mapping and the experiments annotation standardization .
the cleanex tag - to - gene mapping , which provides all expression measurements for one gene under one single name ( usually the official gene symbol ) , has already been described in the former paper ( 3 ) . in brief , all the sequences which appear in a cleanex dataset ( affymetrix probe set sequences , sage or mpss tags , refseq entries ( http://www.ncbi.nlm.nih.gov/refseq/ ) , expressed sequence tags ( ests ) or oligonucleotides ) called
targets are remapped to known rna sequences ( refseq , ests , mrnas , etc . ) , or
features. in the second step , these sequences , through their accession numbers , are mapped onto gene names via the unigene ( http://www.ncbi.nlm.nih.gov/sites/entrez?db=unigene ) database .
note that the tag - to - gene mapping may initially associate one target with multiple genes .
the way such ambiguities are handled has been described in detail in the previous paper ( 3 ) .
note further that the accuracy of the annotation depends both on the genome 's annotation accuracy , and on the depth of the arrays or platforms annotation .
if the authors of the experiments give access to the raw sequences for their platform ( affymetrix , sage and mpss ) , we regularly re - map these sequences onto the continuously growing rna sequence repositories to increase the mapping precision . for other experiments
, the platform annotation often refers to accession numbers of published sequences which matched the spotted sequence at the moment the experiment was carried out .
then , only the mapping of the sequence accession numbers onto unigene clusters is possible , and there is a risk of information loss with time as sequence accession numbers may disappear from unigene .
the regular remapping of accession numbers on the unigene database can anyway improve the accuracy of the gene annotation , as sequences considered as unknown when entered in the databases later become members of unigene clusters of known genes . to follow the continuous evolution of the organisms ' specific gene catalogs ,
in addition to the mapping of dual channel and affymetrix platforms , cleanex now also provides an accurate mapping for sage , longsage , mpss and longmpss tags via a procedure which resembles the one used for affymetrix , except that we reduce the sequence search space by using only rna sequences which have already been associated with sage and mpss tags .
this filter is based on an in - house built human and mouse transcriptome called the trome database ( http://www.isrec.isb-sib.ch/tromer/ ) ( 10 ) . using this filtered sequences database , the procedure maps tags to sequences via the
tagger program ( 11 ) , and then links sequence identifiers to gene names via unigene clusters .
each sage or mpss tag is flagged with a quality tag which indicates its specificity ( figure 1 ) .
the cleanex mapping can be retrieved either on a single - gene basis , or via a batch web query which can handle multiple identifier types , such as unigene , refseq , genbank / embl ( http://www.ncbi.nlm.nih.gov/genbank/ ) gene symbols or entrez geneid ( http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene ) .
the affymetrix probes mapping on ests , mrnas from genbank , refseq mrnas and htcs for each chip and each organism is provided as separated text files on the ftp server ( ftp://ftp.epd.unil.ch/pub/databases/cleanex/affy_mapping ) .
figure 1.mapping process for sage and mpss tags .
sequences belonging to trome clusters are stored in a tempory database the sage or mpss tags are then mapped onto these sequences via the
the quality is given according to the following criteria , for each sage or mpss tag : if all the targeted sequences belong to one or two unigene clusters , the quality is set as high
, if all the targeted sequences belong to more than two but less than five clusters , the quality is set as medium .
for more than clusters , is low . otherwise , the quality is considered as unknown .
sequences belonging to trome clusters are stored in a tempory database the sage or mpss tags are then mapped onto these sequences via the
the quality is given according to the following criteria , for each sage or mpss tag : if all the targeted sequences belong to one or two unigene clusters , the quality is set as
if all the targeted sequences belong to more than two but less than five clusters , the quality is set as medium .
for more than clusters , is low . otherwise , the quality is considered as unknown .
in order to get an accurate experiment annotation from the usual free - text descriptions provided in the data repositories , we have re - annotated all the cleanex datasets with the terms belonging to the mesh controlled vocabulary dictionary .
mesh is the national library of medicine 's controlled vocabulary thesaurus , which is constantly improved and developed .
it consists of sets of terms naming descriptors in a hierarchical structure that allows searching at various levels of specificity .
the mesh thesaurus is used to index articles from biomedical journals for the medline / pubmed database .
the hierarchical structure of this catalog , as well as the fact that it is already used to retrieve biomedical data , makes it a good start to annotate gene expression experiments .
we generated a semi - automatic procedure which first associates the corresponding mesh terms to all its stored synonyms , then searches these terms in the free - text expression experiment annotation and stores the official terms list for each experiment . in a second phase ,
the accuracy of the association between the mesh terms and the experiments is manually verified .
the automatically selected mesh terms are either accepted or rejected , according to their relevance for the given experiment .
this two - step procedure ensures that :
only mesh terms are kept in the experiments annotations , and all the recorded synonyms for each mesh term are checked. the terms retrieved are consistent with the experiment original free - text description .
only mesh terms are kept in the experiments annotations , and all the recorded synonyms for each mesh term are checked .
to ease data retrieval , the final annotation is stored in an indexed file for both the whole datasets and the individual experiments . to keep the mesh tree in a reasonable range ,
only the part of the tree which is related to cleanex datasets or experiments is reproduced on the cleanex query web server .
the biomedical annotations of the datasets can be searched in different ways via the proposed web - based tools .
a list of output examples is also available from the cleanex server ( http://www.cleanex.isb-sib.ch/examples.html ) .
first , the mesh - oriented retrieval tool is linked to the gene - oriented search tools .
this allows users to retrieve specific expression data together with a specific gene description with very high annotation accuracy . as an example
, one can retrieve the list of all the cleanex datasets related to breast cancer and associated with the fibronectin one ( fn1 ) gene via this dual gene / experiment query form .
second , the mesh - based annotation can be used to retrieve and extract numerical expression data from datasets with specific biomedical criteria ( see examples 7 and 8 at http://www.cleanex.isb-sib.ch/examples.html ) .
all the checked terms are then searched in the indexed file , and the corresponding experiments are extracted from the cleanex datasets .
the search along the mesh tree is fast and accurate and can be done either at the datasets level or at the experiments level
. data can thus be extracted either from one single dataset or from multiple , possibly platform - heterogeneous datasets . in the former case , the user can select the numerical field to extract from the original data .
red channel , or the ratio , or directly the normalized data , if these fields are provided by the authors of the experiment . for heterogeneous data retrieval , a rank - based scaling is applied on the numerical data , where all the numerical values for all individual samples or arrays are scaled between 0 and 1000 , in order to make the comparison between data coming from different datasets possible .
the procedure extracts these numerical data for all the common genes across the selected experiments .
all the search tools using the mesh based datasets and experiments annotation can be queried by either using the javascript
walk down the mesh tree page to select the appropriate terms , or by directly listing the specific mesh terms to search in the database . in both cases ,
the terms to search can be linked by different operators ( and , or or but not ) , allowing the generation of complex queries for the indexed annotation files .
an example of such a query could be : colon or pancreas but not cell line and neoplasms but not neoplasm metastasis. after data selection and extraction , the numerical values are provided as a matrix file in which the columns represent the experiments , or samples , and the lines represent either targets , for single dataset extraction , or genes , for heterogeneous data extraction .
these files can then be used as inputs for specific expression data analysis programs , such as r ( http://www.r-project.org/ ) and bioconductor ( http://www.bioconductor.org/ ) , or on - line expression analysis tools , such as epclust ( http://www.bioinf.ebc.ee/ep/ep/epclust/ ) or the sotarray server ( http://www.transcriptome.ens.fr/cgi-bin/gepas/sotarray ) ( 12 ) .
cleanex also provides a comparison tool , in which you can generate two experiments pools based on different biomedical criteria , and extract the scaled numerical values of the corresponding experiments .
the experiments ' description , as well as the gene list , is given in two separated files .
one can then compare the expression level in these two pools via the cleanex analysis system .
this tool is based on a basic mean difference ranking system , which is described in more details in the cleanex online documentation ( http://www.cleanex.isb-sib.ch/tutorial/cleanex_tutorial.html#analysis_step ) . for both pools ,
the difference of the gene position in each pool gives the gene expression bias between the two experiments pools .
from the given result ( a list of genes ordered according to their expression mean ranking difference ) , one can extract the promoter regions of a selected subset of genes .
the sequences provided in fasta format can then be uploaded to web - based motif discovery tools such as signal search analysis ( http://www.isrec.isb-sib.ch/ssa ) ( 6 ) or meme ( http://meme.nbcr.net ) ( 13 ) .
this sequence download system is unique in the sense that the sequence list can be generated from a comparison across heterogeneous expression experiments . as an example
, figure 2 shows the graph obtained by using the ssa server with sequences of genes differentially expressed in cancer tissues .
the two genes ' lists and their corresponding sequences have been obtained via the cleanex comparison tool .
all the cleanex online tools are described in details in the cleanex tutorial ( http://www.cleanex.isb-sib.ch/tutorial/ ) .
figure 2.over-representation of tata - box - occurrences in human genes which show up - regulation in cancer tissues .
promoter sequences for up- and down - regulated sets of genes havae been extracted via the cleanex two pools comparision tool and - box freaquency has been analysed via the ssa server with default options . over - representation of tata - box - occurrences in human genes which show up - regulation in cancer tissues .
promoter sequences for up- and down - regulated sets of genes havae been extracted via the cleanex two pools comparision tool and - box freaquency has been analysed via the ssa server with default options .
adding extraction and analysis tools to transcriptomics repositories has greatly facilitated the use of public data by external users .
the use of a tree - based biomedical ontology system to retrieve specific data is probably well adapted for these repositories which contain such a vast amount of data , as it reduces the search space while going down the ontology tree .
this type of ontologies exists already . as an example , the efo arrayexpress ontology is a member of the open biomedical ontologies ( obo ) ( http://www.obofoundry.org/ ) .
all the ontology databases in obo can be browsed via the ontology lookup service ( ols ) , a centralized query interface for ontology and controlled vocabulary lookup .
though very complete , the obo system is also very complex and stores data coming from a wide range of concepts , amongst which only a few are relevant for expression data annotation .
for that reason , we decided not to use the complete obo ontology , but to focus on biomedical standardized terms used in mesh .
this catalog has already proven to be very useful for retrieval of biomedical scientific publications , and adapting it to gene expression experiments was indeed straightforward .
the cleanex database and its collection of mesh- and gene - oriented query systems can be considered as a proof of concept that using mesh terms , or any other well structured biomedical ontology , for transcriptomics data retrieval is doable and effective .
| ### Summary:
: the cleanex expression database ( http://www.cleanex.isb-sib.ch ) provides access to public gene expression data via unique gene names as well as via experiments biomedical characteristics . to reach this ,
a dual annotation of both sequences and experiments has been generated .
first , the system links official gene symbols to any kind of sequences used for gene expression measurements ( cdna , affymetrix , oligonucleotide arrays , sage or mpss tags , expressed sequence tags or other mrna sequences , etc . ) . for the biomedical annotation , we re - annotate each experiment from the cleanex database with the mesh ( medical subject headings ) terms , primarily used by nlm ( national library of medicine ) for indexing articles for the medline / pubmed database .
this annotation allows a fast and easy retrieval of expression data with common biological or medical features .
the numerical data can then be exported as matrix - like tab - delimited text files .
data can be extracted from either one dataset or from heterogeneous datasets . |
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: on july 14 , 2006 , staggering paresis of the hind legs , incoordination , and intermittent opisthotonos developed in a female barbary macaque ( macaca sylvanus ) .
the monkey , born april 27 , 2005 , was from a group of 200 animals living in 3 social groups .
the animals were kept in a large , outdoor enclosure of a monkey park situated in a tbe - risk area in southern germany .
four days after the onset of clinical signs , the animal became comatose and was euthanized .
blood was collected before euthanasia , and serum was prepared . at necropsy , no macroscopic lesions were observed .
the brain was removed and immediately frozen on dry ice and sectioned in 2-cm slices .
after 48 h , representative areas , including cerebral cortex , hippocampus , basal ganglia , and cerebellum , were embedded in paraffin .
sections ( 35 m ) were cut from each block and stained with hematoxylin and eosin for standard histopathologic evaluation . for immunohistochemical detection of tbev antigens ,
a noncommercial rabbit polyclonal hyperimmune serum ( dilution 1:1,000 ) was used as described previously ( 3 ) .
histologic examination of the brain tissue could be satisfactorily performed despite moderate artifacts caused by freezing ( figure , panel a ) .
moderate perivascular inflammatory cuffs and slight diffuse infiltration of brain parenchyma by mononuclear cells were observed in almost all brain areas , including basal ganglia and cerebellum ( figure , panel b ) . in addition ,
immunohistochemical testing demonstrated several anti - tbev immunoreactive neurons and processes , mainly in purkinje cells of the cerebellar cortex ( figure , panel b ) , and to a lesser extent in pyramidal neurons of the temporal cortex .
a ) moderate perivascular inflammatory infiltrates and slight diffuse infiltration of brain parenchyma by mononuclear cells in basal ganglia ( hematoxylin and eosin stain , bar = 110 m ) .
b ) immunohistochemical findings for tickborne encephalitis virus ( tbev ) : strong immunolabeling of cerebellar purkinje cell perikaryon and apical dendrites ( anti - tbev , bar = 60 m ) . from the frozen material , 10 samples of brain tissue were selected for pcr analysis , including cerebrum , cerebellum , and brain stem ( table ) .
viral rna was extracted from brain tissue with rneasy kit and from cerebrospinal fluid with qiaamp viral kit ( both from qiagen , hilden , germany ) .
the brain tissue was homogenized by bead - milling ( retsch , haan , germany ) with 3-mm stainless steel beads in 0.5 ml of lysis buffer , and the qiashredder system ( qiagen ) was used to improve homogenization .
a modified nested reverse transcription pcr ( nrt - pcr ) was conducted with primer pairs pp1 , pm1 ( reverse transcription and first pcr ) , and pp2 , pm2 ( nested pcr ) ( 4 ) . amplification was done in a 50-l reaction volume containing 10 l 5 buffer , 2 l deoxynucleotide triphosphate mix ( 10 mmol / l ) , 2 l enzyme mix ( all from qiagen ) , 2 l rnase inhibitor ( promega , mannheim , germany ) , 1.25 l primers pp1 and pm1 ( 20 pmol/l ; jena - bioscience , jena , germany ) , 27.5 l diethyl pyrocarbonate ( depc)treated water , and 4 l rna extract .
the reaction was performed in an eppendorf ( hamburg , germany ) thermal cycler for 30 min at 60c for rt and 15 min at 95c for denaturation as the initial step , followed by 40 cycles of pcr with 30 s at 94c , 30 s at 66c , and 1 min at 72c .
differs by 1 nt from strain neudoerfl , the prototype strain of the european virus subtype .
the second amplification reaction was carried out with 4 l of amplification product in a 50-l reaction ( 25 l taq pcr master mix [ qiagen ] , 1.25 l of each primer pp2 and pm2 [ 20 pmol/l ] , and 18.5 l depc - treated water ) . after a denaturation step of 2 min at 95c ,
30 cycles of 30 s at 94c and 30 s at 65c were performed , followed by 10 min at 72c .
pcr products ( 178 bp ) were visualized under uv light after electrophoresis on 1.5% agarose gel and ethidium bromide staining .
bands were cut out , and dna was extracted by using the qiaquick gel extraction kit ( qiagen ) .
dna sequencing was conducted by cycle sequencing , using the bigdye terminator cycle sequencing kit ( applied biosystems , darmstadt , germany ) according to the manufacturer s instructions .
nucleotide sequences were determined on an abi prism 310 genetic analyzer ( applied biosystems ) .
six of the10 brain samples were positive and csf was negative for tbev by nrt - pcr ( table ) .
the sequences of these 6 pcr products ( 178 bp ) differed by only 1 nt from that of strain neudoerfl , the prototype strain of the european virus subtype .
the serum was tested for whole specific tbe antibodies ( immunoglobulin [ ig ] g and igm ) by elisa ( 5 ) .
solid - phase bound antigen and antigen conjugate were from a commercially available test kit ( immunozym fsme , progen , heidelberg , germany ) .
as standards , negative and positive test serum samples were used , and the following limit values were defined : < 5 u / l , negative ; 57 u / l , border line ; 914
u / l , positive ; and > 50 u / l , strongly positive .
the serum of the macaque described in this paper was positive for specific tbe antibodies ( 24 u / l )
experimental infections of macaques with tbev and related flaviviruses ( kyasanur forest disease virus , powassan virus ) have been reported ( 68 ) , but natural infections with tbe virus have not been reported previously . in our case , clinical signs , neuropathologic findings , and immunohistochemical detection of tbev antigen in neurons and of tbev by nrt - pcr indicate that the macaque succumbed to natural tbev infection . although the classical multinodular pattern of lesions in the brain was not observed , the distribution of viral antigens was comparable to that observed in fatal human tbev infection with a short clinical course .
the tbev was characterized as closely related to the european prototype strain neudoerfl , which suggests that the infection was acquired locally by infected ticks .
the monkey park where the animal became infected is situated in southern germany , close to the bodensee ( bodenseekreis ) .
this area , flanked on the west by an area at high risk for tbe ( kreis konstanz ) , is also at risk for tbe . from 1999 to 2006 , a total of 29 autochthonous clinical cases of tbe in humans were reported in the bodenseekreis and 35 in the kreis konstanz ( hellenbrand w. , pers .
comm . ) ; 19% of unvaccinated forestry workers in the bodenseekreis and 15% in the kreis konstanz were seropositive for tbev ( 9 ) .
retrospective analyses of anamnestic data from the affected monkey park show that tbe may have appeared sporadically in macaques in the past .
a monkey died in september 1995 and another in may 2006 , and tbev antigen was subsequently detected in brain tissue from the first animal and antibodies to tbev were detected in both animals ( 12 u / l and 46 u / l , respectively , by elisa ) .
clinical signs of encephalitis were observed in another animal in 1999 , but it seroconverted ( 42 u / l , elisa test ) and recovered after 2 months .
thus , tbe should be considered as a differential diagnosis in cases of encephalitis in monkeys kept outdoors in areas at risk for tbe .
further seroepidemiologic studies are planned to determine the status of tbev infection among animals in this german monkey park . | ### Summary:
: we describe tickborne encephalitis ( tbe ) in a monkey ( macaca sylvanus ) after natural exposure in an area at risk for tbe .
tbe virus was present in the brain and could be identified as closely related to the european subtype , strain neudoerfl . |
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: proliferating trichilemmal cyst ( ptc ) , also known as pilar tumor , is a rare benign skin neoplasm with outer root sheath differentiation .
this neoplasm was first recognizedby wilson - jones in 1966 as an entity that had the histologic capacity to simulate squamous cell carcinoma .
different terminologies have been used to describe this tumor , pilar tumor of the scalp , ptc , giant hair matrix tumor , hydatidiform keratinous cyst , trichochlamydocarcinoma , and invasive hair matrix tumor .
it mainly occurs on the scalp in elderly women and its histological hallmark is the presence of trichilemmal keratinization .
a 70-year - old female presented to skin outpatient department with complaint of a slowly growing mass on the scalp for the past 2 years [ figure 1 ] .
no history suggestive of trauma and chronic irritation except hair combing was present . on examination ,
the lesion was firm , mobile , painless , and measured 6 5 3 cm and was not fixed to the underlying bone .
contrast - enhanced computed tomography scans of the brain also did not show any evidence of intracranial invasion .
excisional biopsy was done and histopathology revealed well - demarcated tumor with variably sized lobules of squamous epithelium [ figure 2 ] undergoing an abrupt change into eosinophilic amorphous keratin without granular cell layer ( trichilemmal keratinization ) with formation of parakeratotic cells without granular cell layer [ figure 3 ] .
clinical picture showing firm , vascular mass in right occipital region ( 6 5 3 cm ) variably sized lobules of squamous cells with central keratinization ( h and e , 40 ) proliferating squamous cells with trichilemmal keratinization ( h and e , 00 ) lobules of clear cells ( h and e , 40 )
it is believed that ptc has an association with pilar cysts which are sometimes observed to precede or accompany these tumors but some ptcs arise de novo .
the majority of cases , about 90% , occur on the scalp with remaining 10% occurring mainly on the back .
starting as a subcutaneous nodule , it may be misdiagnosed as epidermal or trichilemmal cyst .
it can be differentiated from squamous cell carcinoma by the abrupt mode of keratinization , trichilemmal differentiation , the presence of clear cells resulting in glycogen storage and most importantly , a sharp demarcation without infiltration into surrounding structures .
ptt shows features of typical pilar cyst , but additionally shows extensive epithelial proliferation , variable cytologic atypia and mitotic activity .
ptt is usually benign and rarely may undergo malignant transformation in a step - wise manner starting with an adenomatous stage of the trichilemmal cyst to an epitheliomatous stage of the ptt evolving into the carcinomatous stage of the malignant ptt , which is main consideration in the differential diagnosis .
the distinguishing feature of the malignant tumor is the addition of a frankly invasive component that may retain a clear cell pattern with classical trichilemmal keratinization .
nuclear and mitotic activities are variable . vascular and/or perineural invasion may also be observed .
thus , complete excision is recommended for all benign proliferating variants owing to their potential for locally aggressive behavior and malignant transformation
. the large size of the lesion and it was clinically confused with squamous cell carcinoma . | ### Summary:
: proliferating trichilemmal cyst ( ptc ) , a rare benign tumor , is a fascinating follicular neoplasm .
it occurs on head and neck region of elderly women and its histologic hallmark is trichilemmal keratinization .
a 70-year - old female presented to skin outpatient department with complaints of a slowly growing mass on scalp for the past 2 years . on examination , the lesion was firm , mobile , painless , and measured 6 5 3 cm and was not fixed to the underlying bone .
laboratory investigations were unremarkable .
excisional biopsy was done .
histopathology revealed well - demarcated tumor with variably sized lobules of squamous epithelium undergoing an abrupt change into eosinophilic amorphous keratin without granular cell layer ( trichilemmal keratinization ) .
ptc should be differentiated from trichilemmal cyst as it has potential for malignant transformation .
thus , complete excision is recommended for all benign proliferating variants owing to their potential for locally aggressive behavior and malignant transformation . |
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: death due to traumatic injury is the leading cause of life years lost throughout the world and hemorrhage is responsible for 30 to 40% of total trauma mortality , accounting for almost 50% of the deaths in the first 24 hours following trauma .
recently , an early and previously unrecognized acute coagulopathy of trauma ( act ) was described in 25% of admitted patients and occurring before the above - mentioned traditional causes of traumatic coagulopathy .
this act has injury severity and shock and hypoperfusion as the key drivers , and is characterized by activation of the protein c system and hyperfibrinolysis . in the last decade ,
the concepts of damage control surgery have evolved , prioritizing early control of the cause of bleeding by temporary , non - definitive means .
similarly , the concept of damage controls resuscitation , i.e. , providing large amount of blood products to critically injured patients in an immediate and sustained manner as part of an early massive transfusion protocol , reducing the amount of crystalloid administered , has been introduced .
the rationale behind this resuscitation concept is to transfuse red blood cells , plasma , and platelets ( plt ) in the same proportion as found in circulating whole blood , thus leading toward a unit - for - unit ratio to prevent and treat coagulopathy due to massive hemorrhage .
it should be emphasized , however , that such a practice at best will result in a hematocrit around 30% , coagulation factor concentration of about 65% , and a plt count of approximately 90 , and thus being far from what normally circulated in the vascular system .
the aim of the present review , therefore , was to investigate the potential effect on survival of hemostatic resuscitation with proactive administration of plasma and plt in comparison with red blood cells ( rbcs ) in trauma patients with massive bleeding .
english databases , including medline , science direct , cochrane central register of controlled trials , and blackwell science , were searched for reports of massive transfusions in a trauma setting that tested the effects of administration of plasma and/or plt in relation to rbcs on survival from january 2005 to november 2010 . the starting time point was selected as 2005 , because this was the first time early and aggressive administration of fresh frozen plasma ( ffp ) and plt was suggested as a mean of resuscitation for massively bleeding patients .
the keywords , used both individually and in combination , were massive transfusion , damage control resuscitation , hemostatic control resuscitation , massive transfusion protocol , ffp transfusion , plt transfusion , rbc transfusion , ffp : rbc ratio , plt : rbc ratio , and blood product ratios .
the inclusion criteria were ( 1 ) massively transfused patients , defined as receiving 10 or more rbcs within 24 hours or less ; ( 2 ) the presence of two or more patient groups with different transfusion strategies with regard to administration of plasma and/or plt in relation to rbc ; ( 3 ) presenting outcome data defined as 30-day mortality or mortality rate at discharge from hospital with regard to ffp and/or plt transfusion ; and ( 4 ) a retrospective observational investigation or interventional study . given the large heterogeneity between studies in reporting different ratios of ffp and/or plt in relation to rbcs , we chose to compare the highest vs the lowest transfusion ratios from each study included .
statistical meta - analyses were conducted using the revman 5.0.25 software package . the overall pooled risk ratio ( relative risk ) and 95% confidence interval ( ci )
we used the random - effects model in anticipation of clinical and methodological diversity between trials .
statistical heterogeneity between trials was measured by the i statistic , which describes the proportion of heterogeneity not ascribed to random error .
for all calculations , two - tailed p values of less than 0.05 were considered statistically significant .
no randomized studies evaluating the effect of different transfusion ratios were identified . instead , sixteen studies for evaluation encompassing 3 663 patients receiving either high or low transfusion ratios and the characteristics of these studies are presented in table 1.[823 ] confounding factors not possible to obtain when analyzing the data were time of transfusion , age of the blood products , and status of the patients other than being traumatized and in need for massive transfusion .
there were ten studies that tested the effect on survival in relation to ffp or plt to rbc ratio , two studies investigated the effect of ffp and plt to rbc ratios .
four studies evaluated implementation of massive transfusion protocols with preemptive ffp and plt administration vs historic controls [ figure 1 ] .
studies evaluating the effect of high vs low blood product ratios on 30-day mortality in massively transfused trauma patients stratified forest plot of studies included in the meta - analysis ffp / rbc ratios ranged from the highest 1 : 1 ( 0.5 ) to 1 : 9 ( 0.1 ) among all studies . concerning ffp : rbc ratios , the eight studies included a total of 975 patients receiving a high ffp : rbc ratio and 907 patients receiving a low ffp : rbc ratio .
two studies were reports from the combat setting in iraq encompassing 633 patients of whom 521 patients received a high ffp : rbc ratio .
one study was from germany and the remaining were reports from different level 1 trauma centers in usa.[9111323 ] the pooled analysis of the studies furnishing data shows that there was a significantly lower mortality in patients receiving a high ffp : rbc ratio ( odds ratio ( or ) : 0.43 , 95% ci : 0.34 0.55 ) .
two studies addressed the effect of high vs low plt transfusion rates in 641 massively bleeding trauma patients of whom 333 received high plt : rbc ratio .
one study was from the combat setting in iraq , whereas the other reported from an american level 1 trauma center .
the analysis of the two studies furnishing data shows that there was a significantly lower mortality in patients receiving a high plt : rbc ratio ( or : 0.45 , 95% ci : 0.370.55 ) , and this finding was not associated with heterogeneity between the studies ( i = 0% ) .
one study evaluated the effect of both ffp and plt : rbc ratios in 466 patients at 16 us level 1 trauma centers of whom 216 patients received high ratios , and this was associated with a significantly lower mortality ( or : 0.59 , 95% ci : 0 .
reported that high vs low transfusion ratios were associated with improved 30-day survival : plasma : rbc , 59% vs 44% , p=0.03 ; plt : rbc , 63% vs 33% , p<0.01 ; and cryoprecipitate : rbc , 66% vs 41% , p<0.01 .
four american studies evaluated the effect of implementing a massive transfusion protocol on mortality in 858 patients of whom 513 patients received massive transfusion protocol ( mtp)[182022 ] and this was associated with significantly lower mortality ( or : 0.63 , 95% ci : 0.53 0.74 ) and this finding was not associated with significant statistical heterogeneity between the studies ( i = 0% ) . when pooling all the 16 studies , there was a significantly lower mortality in patients receiving high ratios of plasma and/or plt or mtp ( or : 0.49 , 95% ci : 0.430.57 ) .
the finding was associated with significant statistical heterogeneity between the studies ( i = 59% ) .
the result of the present meta - analysis confirms that early aggressive administration of plasma and plt in addition to rbcs is associated with a lower mortality in massively bleeding patients as compared with patients resuscitated with low ratios . in each of the subgroups
investigated , there was a significantly lower mortality observed in those resuscitated with high ffp and/or plt to rbc ratios when the analysis was based on dichotomous stratification of blood product ratios .
reported that when adjusting for the timing of the ffp transfusion , no significant improvement in survival was detected between patients receiving more ffp at 24 hours post - admission and those receiving less .
they reported of a possible survivorship bias related to those patients who lived long enough were the ones who received a higher ffp : rbc ratio , suggesting that the difference in mortality was related to factors other than the transfusion therapy .
scalea et al , retrospectively assessed the relationship between ffp transfusion and survival in trauma patients and reported that in a subset of 81 patients who received more than 10 units of rbcs within 24 hours of admission , no significant difference was found between those who received an ffp : rbc ratio of 1 : 1 compared with those who received a lower ffp : rbc ratio when controlling for age , gender iss , closed head injury , laparotomy status , and length of intensive care unit ( icu ) stay .
these diverging results may be explained by the timing of the ffp administration in relation to when the patients arrive at the hospital , which is important for the outcome of massively bleeding patients .
johansson et al . introduced thawed plasma , enabling immediate administration of ffp together with rbc upon arrival at the trauma center while at the same time reducing the amount of crystalloids and colloids administered to these patients ; this resulted in a reduction in mortality .
administration of large amounts of crystalloids to maintain adequate intravascular volume dilutes the level of coagulation factors , fibrinogen , and plt , and administration of colloids further worsens the coagulopathy by interfering with fibrin polymerization , resulting in a clot with reduced strength and stability .
furthermore , cotton et al . also reported that not only was the 30-day survival higher in the trauma exsanguination protocol ( tep ) group compared with controls , but the incidence of pneumonia , pulmonary failure , and abdominal compartment syndrome was lower in tep patients .
severe sepsis or septic shock and multiorgan failure were also lower in tep patients ( 9% vs 20% and 16% vs 37% , respectively ) .
furthermore , the tep group received more blood products intraoperatively , although the 24-hour total transfusion requirements were lower than in controls , suggesting that early and aggressive administration of plasma and plt reduces the need for later blood transfusions due to improved hemostasis , and that this is important for survival in massively bleeding patients . interestingly ,
riskin et al . reported that implementation of a massive transfusion protocol did not change the transfusion ratios but this may be related to that the time to first ffp and plt transfusions were above 2.5 hours and consequently severe coagulopathy must have occurred before balanced transfusion therapy was instituted .
reporting that the median survival for those dying of uncontrollable hemorrhage was 2 hours and these patients are consequently not resuscitated by delayed balanced transfusion therapy as outlined by riskin et al .
the current meta - analysis investigated the highest vs the lowest transfusion ratios and consequently do not reveal an optimal ratio of ffp to rbcs .
furthermore , equally important , the timing of the ffp transfusions in relation to when administration of rbc was commenced were not reported in most of the studies evaluated and without this information , mere ratios provide insufficient information .
showed that an ffp : rbc ratio > 1 : 1 was associated with the highest survival in german trauma patients , whereas kashuk et al . reported that patients receiving an ffp : rbc ratio of 1 : 2 - 1 : 3 had the highest survival and that a higher ratio was not associated with better outcome , but instead might be harmful .
this is in alignment with davenport et al . who recently reported that ffp : prbc ratios of 1 : 1 do not confer any additional advantage over ratios of 1 : 2 to 3 : 4 , although it should be noted that in this study , the most severely bleeding patients were excluded due to blood sampling failure .
it should be noted , however , that there might be more than one optimal resuscitation ratio according to trauma severity , degree , and dynamics of blood loss , and previous fluid administration among other factors .
the importance of the act for mortality reported by frith and colleagues is established , whereas the optimal treatment of this condition remains elusive .
specifically address this issue finding that in approximately 30% of those requiring massive transfusion presented with a prothrombin time ( pt ) > 1.2 and , hence , trauma induced coagulopathy : they found that administration of a high ratio of ffp was associated with a significantly lower mortality than patients treated with low ratios .
this finding is especially interesting considering that activation of the protein c system is driven by thrombin generation and , therefore , an intervention supporting thrombin generation could have been expected to worsen the act . also , given that act is associated with endothelial damage and glycocalyx degradation , it is notable that freshly thawed ffp exerts a protective effect on the endothelium and glycocalyx and reduces its permeability in animal models of hemorrhagic shock models .
it could be speculated that early administration of high levels of freshly thawed ffp in patients with acute traumatic coagulopathy may contribute to improved survival by protecting the endothelium and thereby attenuating the downstream organ damage associated with capillary leakage .
the role of plt for intact hemostasis is well established and in the present review , nine of the studies reported improved survival in the group of patients receiving the highest ratios of plt to rbc , i.e. , the most plt .
this is in agreement with johansson et al , who demonstrated that administration of plt together with plasma and rbc immediately upon arrival in the operation theatre and throughout surgery was associated with reduced postoperative bleeding and a 50% increase in the 30-day survival in patients undergoing surgery for a ruptured abdominal aortic aneurysm .
this was further corroborated by perkins et al , who reported in a multiple regression analysis that plt transfusion was independently associated with survival .
whole blood viscoelastical assays such as teg and rotem have been shown to be superior to conventional coagulation assays in identifying clinically relevant coagulopathies as well as in reducing the need for blood transfusion in patients undergoing major surgery . in massively transfused trauma patients
, teg has been shown to predict the need for blood transfusion as well as identify atc including hyperfibrinolysis .
the use of teg / rotem in massively bleeding trauma patients is now recommended by current guidelines and teaching books and it could be speculated that systematic use of teg / rotem to identify coagulopathy and guide transfusion therapy might be superior to blind transfusion based on different ratios and this warrants further evaluation .
the main limitation of this review is that it only compared the highest vs lowest transfusion ratios and consequently , no information of a potential optimal transfusion ratio in between was evaluated .
furthermore , a significant statistical heterogeneity between the studies included was found and this should be considered when interpreting the results .
this meta - analysis of retrospective studies concerning massively transfused trauma patients confirms a significantly lower mortality in patients treated with the highest ffp and/or plt ratio when compared with the lowest ffp and/or plt ratio . | ### Summary:
: background : continued hemorrhage remains a major contributor of mortality in massively transfused patients and controversy regarding the optimal management exists although recently , the concept of hemostatic resuscitation , i.e. , providing large amount of blood products to critically injured patients in an immediate and sustained manner as part of an early massive transfusion protocol has been introduced .
the aim of the present review was to investigate the potential effect on survival of proactive administration of plasma and/or platelets ( plt ) in trauma patients with massive bleeding.materials and methods : english databases were searched for reports of trauma patients receiving massive transfusion ( 10 or more red blood cell ( rbc ) within 24 hours or less from admission ) that tested the effects of administration of plasma and/or plt in relation to rbc concentrates on survival from january 2005 to november 2010 .
comparison between highest vs lowest blood product ratios and 30-day mortality was performed.results:sixteen studies encompassing 3,663 patients receiving high vs low ratios were included .
this meta - analysis of the pooled results revealed a substantial statistical heterogeneity ( i2 = 58% ) and that the highest ratio of plasma and/or plt or to rbc was associated with a significantly decreased mortality ( or : 0.49 ; 95% confidence interval : 0.43 - 0.57 ; p<0.0001 ) when compared with lowest ratio.conclusion:meta-analysis of 16 retrospective studies concerning massively transfused trauma patients confirms a significantly lower mortality in patients treated with the highest fresh frozen plasma ( ffp ) and/or plt ratio when compared with the lowest ffp and/or plt ratio .
however , optimal ranges of ffp : rbc and plt : rbc should be established in randomized controlled trials . |
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: yellow mosaic disease of blackgram ( vigna mungo ) is caused by mungbean yellow mosaic india virus ( mymiv ) .
irregular , chlorotic , yellow patches on the leaves indicate successful disease onset the characteristic phenotype of mymiv - infected susceptible plants .
it is one of the most devastating types of biotic stresses that causes up to 100% damage to a large number of leguminous crops .
one candidate mymiv resistance gene , cyr1 , has been reported by maiti et al . and introgressed to develop several recombinant inbred lines ( rils ) . here
we report the transcriptome data of mock inoculated control and mymiv infected resistant ril , vm84 .
the total number of processed reads for the two samples was found to be 77.342016 for the control and 107.47377 million reads for the mymiv inoculated cultivars , indicating a rise in approximately 30 million reads for the infected genotype ; probably as a result of the expression of stress and defense pathway associated genes ( fig .
1 ) . following assembly of the reads into contigs this difference in expression between the control and the inoculated sets was found to be more evident as depicted in fig .
however , average contig lengths were found to be more or less proportional ( fig .
3 ) , indicating that the difference in the number of contigs can be attributed to the differential expression of a few genes as well as expression of new genes as a result of infection and associated stress . de - novo assembly of illumina hiseq2000 data was performed using velvet-1.2.10 and oases_0.2.083 was used for transcript generation for various k - mers and concluded that hash lengths ( k - mer ) 55 ( for control sample ) and 57 ( for mymiv - infected sample ) were better than others considering various parameters like the total number of transcripts generated , maximum transcript length , total transcript length and less number of n 's . de - novo transcript statistics is presented in table 1 . in the absence of genomic information , v. mungo transcripts were annotated using the following databases : i.medicago protein ( uniprot)ii.soybean protein ( uniprot)iii.cowpea est ( ncbi ) .
medicago protein ( uniprot ) soybean protein ( uniprot ) the annotation statistics are shown in table 2 .
the total number of processed reads for the two samples was found to be 77.342016 for the control and 107.47377 million reads for the mymiv inoculated cultivars , indicating a rise in approximately 30 million reads for the infected genotype ; probably as a result of the expression of stress and defense pathway associated genes ( fig .
1 ) . following assembly of the reads into contigs this difference in expression between the control and the inoculated sets was found to be more evident as depicted in fig .
2 . however , average contig lengths were found to be more or less proportional ( fig .
3 ) , indicating that the difference in the number of contigs can be attributed to the differential expression of a few genes as well as expression of new genes as a result of infection and associated stress .
de - novo assembly of illumina hiseq2000 data was performed using velvet-1.2.10 and oases_0.2.083 was used for transcript generation for various k - mers and concluded that hash lengths ( k - mer ) 55 ( for control sample ) and 57 ( for mymiv - infected sample ) were better than others considering various parameters like the total number of transcripts generated , maximum transcript length , total transcript length and less number of n 's . de - novo transcript statistics is presented in table 1 .
in the absence of genomic information , v. mungo transcripts were annotated using the following databases : i.medicago protein ( uniprot)ii.soybean protein ( uniprot)iii.cowpea est ( ncbi ) .
medicago protein ( uniprot ) soybean protein ( uniprot ) the annotation statistics are shown in table 2 .
plants samples ( mock inoculated control and mymiv infected v. mungo , line vm84 ) were collected and prepared following the method described by kundu et al . .
total rna was extracted from control and infected leaves using trizol reagent ( invitrogen , carlsbad , ca ) following the manufacturer 's protocol , followed by dnase - i treatment ( sigma - aldrich , usa ) and purification in an rneasy plant mini kit ( qiagen , usa ) .
qualitative and quantitative assessments of the extracted rna were done by an agilent 2100 bioanalyzer ( rna nano chip , agilent ) .
( bangalore , india ) for preparation of transcript library and high throughput sequencing using illumina hiseq 2000 platform .
rna sequencing has become a common method for analyses of functional plant genomics . direct sequencing of mrna provides a cost effective alternative to microarray technology for the analyses of gene expression for the entire transcriptome of a particular species .
cell type specific transcript levels provide important research avenues for assessing the exact range of reads per sample for analyzing differential gene expression .
it was claimed that depth of coverage is directly proportional to the identification of new genes , , .
li et al . has established , using a negative binomial model of variations , that log2 fold change of two or more decreased the number of replicates to a maximum of six for effective identification of differentially expressed genes . | ### Summary:
: mungbean yellow mosaic virus ( mymiv ) is the viral pathogen that causes yellow mosaic disease to a number of legumes including vigna mungo .
vm84 is a recombinant inbred line resistant to mymiv , developed in our laboratory through introgression of resistance trait from v. mungo line vm-1 . here
we present the quality control passed transcriptome data of mock inoculated ( control ) and mymiv - infected vm84 , those have already been submitted in sequence read archive ( srx1032950 , srx1082731 ) of ncbi .
qc reports of fastq files generated by seqqc v2.2 bioinformatics tool . |
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: when two events overlap or take place in close proximity to each other , then their simultaneity can be attributed to ( i ) coincidence , which is a conjunction of two independently explicable events , ( ii ) direct causation , when one event triggers the other and there is a causal relation that links one with the other or ( iii ) indirect causation , when the two events are each related to a third factor that has triggered each .
acute rejection ( ar ) and lymphocele formation are well - recognized post - renal transplant complications .
evidence from experimental and observational data points to an association between ar and lymphocele formation , but a causal link has not been established .
a 50-year - old man who had end - stage renal disease secondary to diabetic nephropathy underwent an uncomplicated right iliac fossa 1 - 1 - 2 human leucocyte antigen ( hla ) mismatch deceased donor kidney transplantation .
the recipient had class i panel reactive antibodies ( pras ) titre of 97% , but t- and b - cell igg flow cytometric crossmatch was negative .
induction therapy with anti - thymocyte globulin ( atg ) , tacrolimus and mycophenolate mofetil ( mmf ) was given .
the allograft functioned immediately after transplantation and serum creatinine ( scr ) decreased to 105 mol / l ( 1.18 mg / dl ) on the third post - operative day .
ultrasonography ( us ) of the transplanted kidney performed on the second and ninth post - operative day revealed normal renal blood flow patterns and no hydronephrosis or fluid collection .
mol / l ( 1.66 mg / dl ) was noted 3 weeks after transplantation . once again us and doppler studies were unrevealing .
renal allograft biopsy was done ; histology revealed severe tubulitis and interstitial inflammation affecting 30% of parenchyma ( banff type ib , t - cell - mediated rejection ) as well as glomerulitis with margination and c4d positivity ( banff type ii , antibody - mediated rejection ) .
treatment with pulse methylprednisolone ( 500 mg / day for 5 days ) , atg ( total of 7.5 mg / kg ) along with plasma exchange ( pe ; eight treatments on an alternate day schedule ) and iv immunoglobulin ( 100 mg / kg after each pe ) was given .
frequent infusions of cryoprecipitate were required to correct hypofibrinogenaemia associated with pe therapy . at the end of this treatment ,
transplant ureteric stent was removed 6 weeks after transplant ; a follow - up us did not show any hydronephrosis , but demonstrated that the peri - transplant collection had increased in volume to 226 ml .
two weeks later , patient developed acute graft dysfunction [ scr 247 mol / l ( 2.79 mg / dl ) ] and swelling of the right leg .
us revealed a large fluid collection ( 1163 ml ; 14.5 16.9 9.3 cm ) medial to the inferior pole of the kidney transplant causing ureteral compression and moderately severe hydronephrosis .
the collection was drained using a pigtail catheter ; biochemical analysis of the aspirated fluid revealed creatinine 91 mol / l ( 1.03 mg / dl ) and protein 8
g / l ( 0.8 g / dl ) [ scr 93 mol / l ( 1.05 mg / dl ) and serum protein 58
following removal of the pigtail catheter , lymphocele re - accumulated and hence , a laparoscopic marsupilization was performed .
a follow - up ultrasound showed minimal hydronephrosis with no radio - tracer hold - up in the collecting system on renal transplant scintigraphy .
our patient developed a lymphocele in close association with ar , and the question is was it a coincidence or was it causally related ?
of course , one may argue that it was a random coincidence ; both ar and lymphocele are well - known complications after transplantation and each has its independent set of required conditions .
our patient was at a high - immunological risk of ar in view high pra and a number of hla mismatches .
virtually all lymphatic connections of the transplanted kidney and some of the recipient 's lymphatic vessels are unavoidably divided during transplantation .
it is impractical to ligate / coagulate every transected lymphatic channel , exudation from which can lead to the formation of post - transplant lymphocele .
hence , meticulous lymphostasis and minimization of tissue dissection in the recipient have been shown to reduce the incidence of post - transplant lymphocele .
the patient also had diabetes , another recognized risk factor for post - operative wound healing complications , that could have contributed to lymphocele formation .
conversely , we contend that ar and development of lymphocele in our patient represented a cause - effect relationship .
first , the time precedence serial post - operative ultrasound studies gave us the opportunity to precisely ascertain the onset time of lymphocele .
there was no lymph collection at the time of diagnosis of ar ; lymphocele accumulated rapidly after the diagnosis and treatment of ar ( figure 1 ) and achieved sufficient volume to mechanically compress the transplant ureter and iliac veins .
temporal precedence criteria for causation , i.e. the cause ( ar ) preceded the effect ( lymphocele ) .
mp , methylprednisolone ; atg , anti - thymocyte globulin ; pe , plasma exchange ; ivig , iv immunoglobulin .
mp , methylprednisolone ; atg , anti - thymocyte globulin ; pe , plasma exchange ; ivig , iv immunoglobulin .
secondly , the biological plausibility ar as a cause of lymphocele is biologically conceivable .
ar causes an intense local vascular and cellular inflammatory response with subsequent dilatation and increased permeability of the small blood vessels .
the experimental mechanistic evidence came from pedersen and morris who used a transplant sheep model , where kidneys were implanted in the neck and renal lymphatics were cannulated for monitoring lymph flow .
they demonstrated a remarkable 20- to 50-fold increase in renal lymphatic drainage from rejecting allogenic renal grafts compared with unchanged lymph flow in autografts .
thirdly , the growing evidence from observational studies showing that the majority of the symptomatic / large lymphoceles are associated with prior or concomitant rejection episodes [ 1 , 79 ] . in a prospective study of 118 renal transplants , khauli et al . reported that only ar was associated with a significant risk for lymphoceles by multivariate analysis of risk factors .
the occurrence of ar posed a 25- to 75-fold increased likelihood of the development of symptomatic and asymptomatic lymphoceles , respectively .
after adjusting for ar , no other risk factor came close to being significant . finally , there are no plausible explanations for reverse causation
ar can cause development of a lymphocele , but the reverse is not true . in other words ,
animal studies have shown that remodelling of the lymphoid system begins as early as 12 weeks after solid organ transplantation , so that the graft lymphatics start to establish new connections with the host lymphatic system by means of lymphangiogenesis .
restoration of the lymphatic network can enhance immune cells traffic to lymphoid tissue thereby initiating the immune response against the donor kidney . a pathological analysis by yamamoto et al . revealed that patients with acute cellular rejection , acute antibody - mediated rejection or peritubular capillaritis exhibited a 4- to 9-fold increase in lymphatic vessel density .
also demonstrated in sequential protocol biopsies that cortical lymphangiogenesis can be found in 66% of renal allografts with any cellular infiltrates .
these findings , however , might also suggest lymphangiogenesis as a consequence rather than a cause of ar , implying a bidirectional relationship between ar and lymphangiogenesis . inflammation and
increased amount of tissue fluid during ar can stimulate lymphangiogenesis in the allograft in order to provide exit routes for tissue fluid and cellular infiltrates thereby assisting in resolution of inflammation .
the quantitative extent of lymphatic reconnection between the renal allograft and the recipient lymphatic system may eventually determine the size of the lymphocele .
if lymph production is overwhelming and remodelling of lymphatic network relatively inadequate , then a relatively large amount of lymph will exude from divided allograft lymph channels into the free space resulting in a bigger lymphocele .
owing to the close proximity of ar to its treatment , disentangling the causal contribution of each to the development of lymphocele remains a thorny issue .
the use of modern immunosuppressive agents has been linked with considerable increased rates of wound healing disorders .
although this appears to be particularly true for sirolimus ( not used in our patient ) , both high - dose steroid therapy and mmf can potentially impair fibroblast - mediated collagen formation and remodelling resulting in impaired healing of disrupted lymphatics and consequently , lymphocele formation .
demonstrated that incidence of lymphocele was not significantly different among multiple immunosuppressive regimens if careful closure of lymphatics was performed . in conclusion
, we feel that conjunction between ar and lymphocele formation should not be dismissed as a mere coincidence .
although recent multicentre studies do not point to a close relation between ar and lymphocele , there is evidence to support a multifaceted relation between ar , lymphangiogenesis and lymphocele formation .
ar appeared to be a genuine factor implicated in the pathogenesis of lymphocele in our patient , although the possible additive role of other factors , such as diabetes and immunosuppressive agents , can not entirely be excluded ; temporality , biological plausibility , experimental evidence and observational data all corroborate causality .
an additional well - designed prospective study is required to rigorously evaluate the causal connection between ar and post - transplant lymphocele and to evaluate the relative extent and the role of the other contributing factors .
| ### Summary:
: a renal transplant patient developed a lymphocele soon after an episode of acute rejection ( ar ) .
the lymphocele rapidly increased in size causing transplant ureteric and venous obstruction , leading to acute graft dysfunction and swelling of the ipsilateral leg .
we appraise the complex relationship that exists between ar , lymphangiogenesis and lymphocele formation to determine whether a case for a causal connection between ar and development of lymphocele can be made in our patient . |
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: life - threatening acute lung injury due to combat and/or terror attacks is associated with high mortality .
the successful management includes the use of rescue extracorporeal lung assist and early transport by aeromedical evacuation teams .
description of the pre - hospital support of a severely injured soldier with a pumpless extracorporeal arterio - venous lung assist in critical hypercapnia / hypoxemia .
a british soldier suffered from severe gunshot injuries to the chest and abdomen in afghanistan .
he was mechanically ventilated and supported with a pumpless interventional extracorporeal lung assist ( ila , novalung , talheim , germany ) and transferred to germany .
a sufficient co2 extraction and improvement in oxygenation enabled the safe transportation and lung protective ventilation . weaning from mechanical ventilation
was promoted by the application of a new neurally adjusted ventilatory assist ( nava ) .
novel techniques in extracorporeal lung assist and in ventilatory support may help save lives even in disaster medicine .
successful combat care requires efficient casualty care centers and an early transport of critically injured patients by aeromedical evacuation teams .
the use of extracorporeal lung assist by acute lung rescue teams has been reported in soldiers suffering from life - threatening acute lung injury .
we believe that our patient would not have survived the transport without early implementation of ila in the field .
the system provides excellent co2 elimination , allowing lung protective ventilation of the remaining lung .
we believe that the addition of a novel ventilation mode ( nava ) , characterized by proportional unloading of the respiratory muscles , improved subject - ventilator synchrony , minimized inspiratory pressures and enabled successful weaning in a critical limitation of breathing capacity without perspective of early lung transplantation .
all authors were involved in managing the patient , discussing and planning logistic aspects of transportation and writing the report . | ### Summary:
: backgroundlife - threatening acute lung injury due to combat and/or terror attacks is associated with high mortality .
the successful management includes the use of rescue extracorporeal lung assist and early transport by aeromedical evacuation teams.aimsdescription of the pre - hospital support of a severely injured soldier with a pumpless extracorporeal arterio - venous lung assist in critical hypercapnia / hypoxemia.methoda british soldier suffered from severe gunshot injuries to the chest and abdomen in afghanistan .
after traumatic pneumonectomy , he developed critical hypercapnia / hypoxemia .
he was mechanically ventilated and supported with a pumpless interventional extracorporeal lung assist ( ila , novalung , talheim , germany ) and transferred to germany.resultsa sufficient co2 extraction and improvement in oxygenation enabled the safe transportation and lung protective ventilation . weaning from mechanical ventilation was promoted by the application of a new neurally adjusted ventilatory assist ( nava ) .
the patient recovered , and he left germany in stable condition.conclusionnovel techniques in extracorporeal lung assist and in ventilatory support may help save lives even in disaster medicine . |
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: forceps has been an integral part of obstetrician 's armamentarium . since , its introduction by chamberlain family centuries ago ,
this art of instrumental delivery , though has benefited many , it has also led to numerous litigations due to poor fetal and sometimes maternal outcome leading to reluctance in its use . in this present day , when there is a universal concern regarding the alarming rise of caesarean section rates , a better understanding of this instrument will help the patient as well as the obstetrician .
this study is to evaluate the outcome of its use in a teaching institution over a 2-year period .
all cases of forceps deliveries were included , a total of 120 , all which were singleton fetus in cephalic presentation . the choice of instrument and the indications were noted .
the parameters studied were maternal outcome such as injuries and postpartum hemorrhage ( pph ) , and fetal such as apgar scores at birth , neonatal intensive care unit ( nicu ) admission , injuries , and mortality .
a total of 120 cases were studied and the mean age of the patients was 24 years .
the most common indication for application was fetal distress ( 47.5% ) followed by poor maternal efforts ( 30% ) .
indications of forceps application a total of 15 cases ( 12.5% ) of maternal injuries were noted with 2 cases of uterine rupture , 4 complete perineal tears and 9 minor cervical and vaginal lacerations .
furthermore , pph occurred in 5 ( 4.2% ) cases , three being atonic and 2 traumatic associated with rupture uterus .
a total of 4 cases of complete perineal tears ( where the tear involves the external anal sphincter ) were there .
3resulted from outlet forceps applied in primigravida and 2 babies among these were large for gestational age .
the first was a second gravida , previous normal delivery , low forceps applied for fetal distress and a 2.5 kg baby delivered .
the second case was a second gravida with previous lower segment cesarean section ( lscs ) where outlet forceps was applied for fetal distress and a 2.7 kg baby delivered .
regarding the neonatal outcome , 12 babies ( 10% ) had low apgar and required nicu admission out of which one baby died , which was a case of multiple instrumentations . in all but
cases with 1 and 5 min apgar scores of less than 4 and 7 were 12 ( 10% ) and 11 ( 9.1% ) respectively .
the most frequent indication for forceps application in a bulgarian study was fetal distress ( 78.1% ) , which is the most common indication in modern obstetrics for the past 15 years , similar results were found in the present study ( 46.3% ) . however , the next most frequent indication in the aforementioned study was prolonged 2 stage ( 23.6% ) ( i.e. , where delivery is delayed for more than 2 h in primigravida and 1 h in multigravida after full dilatation of the cervix ) , whereas it was poor maternal efforts ( 30% ) in this study . in another study in cameroon , the most common indication was prolonged 2 stage of labor . in a study in texas university
the most common indication was fetal distress followed by poor maternal efforts , which agrees with our present study . in another indian study , cutting short of 2 stage of labor ( i.e. , where prolonged bearing down is detrimental for the mother in cases of hypertension , heart disease etc . ) was the chief indication followed by prolonged 2 stage . regarding maternal injuries , the study in cameroon , where the rate of instrumental deliveries was 2.3% , reported only minor vaginal and perineal lacerations , whereas in the present study with a rate of 3% instrumental deliveries , total 15 ( 12.5% ) cases had maternal injuries . the minor cervical and vaginal lacerations were easily managed with a few extra sutures during episiotomy wound repair . in the aforementioned indian study forceps delivery was found to be significantly associated with episiotomy extension and perineal tears .
the risk factors for 3 and 4 degree perineal lacerations ( i.e. , complete perineal tears where the external anal sphincter is injured ) as found in other studies were forceps delivery , nulliparity , increased baby weight and episiotomy . in the present study , out of the 4 cases of complete perineal tear , 3 were primigravida , 2 babies were large for gestational age and all cases had a mediolateral episiotomy .
complete perineal tears can occur in deliveries other than instrumental also when the baby weight is more , short perineum , poor perineal support during the delivery and sudden extension of the head or forceful delivery of shoulder of the baby .
the patient requires liquid diet for 24 h and a low residue diet with stool softener for another 3 days and discharged after she has passed stools and the wound looks healthy . following a 34-year follow - up of forceps delivery bollard et al .
reported that significant perineal injuries after forceps delivery was no more than that seen in normal vaginal delivery . in another study , though instrumental delivery had a strong association , persistent occiput posterior position did not make an impact on the risk of complete perineal tear . here
, 6 cases were there with face to pubis delivery and 3 had minor perineal lacerations .
a study in nigeria reported a strong correlation of oxytocin use , forceps delivery and fundal pressure with intra - partum uterine rupture . in this study , 2 cases of uterine rupture occurred .
the first was a scar rupture in a case of previous lscs where emergency laparotomy was carried out with rent repair . in women undergoing trial of vaginal birth after caesarean section , forceps application
is recommended to cut short second stage to prevent prolonged bearing down by the mother , also these patients have a risk of intra - partum scar rupture of 0.7% as found by the national institute of child health and human development study .
the other one was a multigravida with pre - labor membrane rupture where cervical priming agent prostaglandin e2 gel was used , which unfortunately caused hyperstimulation leading to fetal distress necessitating forceps delivery .
the reason for this rupture is unclear , if caused by instrument this must have resulted from a high or mid - cavity application of forceps , which is not recommended in modern day obstetric practice .
the other possible explanation is hyperstimulation by the uterotonic agent prostaglandin in a multiparous uterus leading to a spontaneous rupture .
regarding perinatal outcome , 12 ( 10% ) babies had poor apgar scores of less than 4 at 1 min requiring nicu admission out of which 11 were given back to the mother within 3 days .
fetal distress was the indication for forceps application in all but one of these cases .
the indication of distress as such might have caused the poor apgar scores in these babies rather than the use of an instrument .
the decision of lscs in fetal distress with a deeply engaged head in the birth canal would have led to delay in delivery due to shifting time to an operation theater a difficult head delivery during cesarean section as well as operative morbidity to the mother without improving the apgar scores .
though , poor apgar is commonly attributed to the use of forceps , another author has commented that this might be due to the labor process itself rather than the instrumentation .
one baby died due to asphyxia where failed vacuum extraction was followed by forceps application .
sequential use of multiple instruments has a poorer outcome according to rcog guidelines and such use lead to this case of perinatal mortality in the study .
this art of delivery is a reasonable option to the obstetrician to reduce the rising cesarean section rates .
however , extreme caution and judicial use of this instrument is required in expert hands to prevent risks for mother and fetus .
training programs should be conducted to impart knowledge about its indications , technique of use and quality control . | ### Summary:
: introduction : the art of forceps delivery though existing for centuries has earned a disreputation due to the possibility of poor maternal and fetal outcome .
however , its safe use can reduce the rising cesarean section rates in the present times .
this study is to see the outcome of its use in a teaching hospital over a 2 year period.materials and methods : in this retrospective observational study , 120 cases of forceps delivery were studied for maternal outcome such as injuries , postpartum hemorrhage , and fetal outcome such as apgar score at birth , neonatal intensive care unit admissions , injury , and mortality.results:the most common indication was fetal distress ( 47.5% ) .
a total of 15 cases ( 12.5% ) of maternal injuries occurred , with 2 uterine ruptures one of which was in a previous lower segment caesarean section case , 4 complete perineal tears and 9 minor cervical and vaginal lacerations .
a total of 12 babies ( 10% ) had poor apgar scores who recovered after resuscitation and one out of them died , which was a case of multiple instrumentation.conclusion:forceps is a reasonable option for the obstetrician to reduce the caesarean section rates ; however , extreme caution , proper expertise and judicial use of this instrument are required to prevent undue risk to mother and fetus . |
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: harlequin ichthyosis ( hi ) is a lethal disease , but victims in very rare cases may survive for several months or years .
in addition , ectropion , lack of development of the external parts of the nose and ears , eclabium and open mouth , hypoplastic fingers , anonychia and mobility limitation of the joints are some other clinical features of the hi .
patients with hi are at high risk for hypo / hyperthermia , dehydration , respiratory distress , hypoventilation , malnutrition , hypernatremia , seizure , and skin infection .
hi is associated with preterm birth and often leads to death due to neonatal complications such as fluid loss and septicemia .
a 31-year - old pregnant woman was admitted to the zabol amir - al - momenin hospital for her third pregnancy due to preterm , premature rupture of membrane and obstetric pain .
gestational age was approximately 30 weeks and 1 day based on both the first day of the last menstrual period and ultrasound .
no remarkable complication was noted in the last ultrasound examination at 28 weeks of pregnancy .
her birth weight , length , and head circumference was 2.1 kg , 44 cm , and 29 cm , respectively [ figure 1 ] .
thick skin with deep fissures , general hyperkeratinization , cyanosis , flat fontanels , ectropion , immature eyes and auricles , eclabium , bradycardia , bradypnea , and moaning were noted in the physical examination .
antibiotic therapy and conservative treatments were started after admission to the neonatal intensive care unit . however , the parents self - discharged their newborn daughter at the same day after birth .
the patient with deep cracked skin , open wide mouth , abnormal eyes , and flatted nose and ear
this gene plays a major role in transporting lipids to cells that form the epidermis and the normal development of the skin . at birth ,
infants are covered with hard hyperkeratonic armor , composed of large , thick , yellowish brown , and very sticky plates .
after birth , deep red fissures occur on these hard and inflexible plates that extend to the dermis , resulting in a joker - like skin .
in addition , patients with hi have respiratory failure as a result of restricted chest expansion and skeletal deformities . feeding problems may result in low blood sugar , dehydration , and kidney failure .
families with one or more children with hi have been previously reported . a boy with hi
the first case was a 2.0 kg premature girl who was delivered at 32 weeks of pregnancy and died 3 days after birth .
therefore , obtaining the family history , consanguinity between the parents , and the presence of other skin disorders in offspring would be very helpful for early diagnosis of the disease .
microscopic examination of the amniotic fluid cells and ultrasound for assessment of the shape of fetal mouth at 17 weeks of pregnancy might be useful for the early detection .
prenatal diagnosis can also be feasible using skin biopsy at 24 weeks of pregnancy , especially among the families with a history of hi .
although ultrasonography can be useful in some cases but it might not be applicable due to delayed phenotypic expression and the rarity of the disease .
furthermore , sequence analysis of abca12 should be done first for the individuals with hi history .
the mortality of hi is high and most of the victims die within a few weeks of birth because of secondary complications such as infection and dehydration .
however , survival contributes to the type of mutations ; victims with the compound heterozygote mutation survive more than those with the homozygote mutation . in addition , advances in the postnatal treatments and cares improve the prognosis of the disease .
in addition to the routine care such as checking vital signs , patients should be kept in a warm and humid incubator .
taking shower twice per day , saline compresses and gentle emollients must be used to keep the skin soft and to accelerate the desquamation .
environment must be cleaned up to prevent infection ; hence , repeated cultures of the skin would be essential to detect the hazardous microorganisms .
in addition , genetic counseling and molecular investigation of the abca12 gene should be considered .
the supportive care such as oxygen therapy , transporting to incubator , using normal saline to cleanse and moist the skin was performed early after birth .
however , the patient was self - discharged by parents at the same day of birth , and there was no more information regarding her survival .
we suggest that mutation screening of the abca12 gene and genetic counseling of families would be important especially in families with a consanguinity marriage . | ### Summary:
: harlequin fetus is a rare and the most severe form of the congenital ichthyosis with an autosomal recessive inheritance .
incidence of the disease is nearly 1 in 3,00,000 live births
. the disease might be lethal at birth and the affected babies are often premature .
harlequin ichthyosis ( hi ) is marked by severe keratinized and alligator - like horned skin .
the present study reports a new case with hi and adds to the collective knowledge of this rare skin disorder .
hi has been linked to mutation in the abca12 gene ; therefore , genetic counseling and mutation screening of this gene should be considered . |
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:
st was a research fellow of the japan society for the promotion of science ( jsps ) . | ### Summary:
: abstractwe developed a new method to observe distribution of phosphatidylinositol 3,5-bisphosphate [ ptdins(3,5)p2 ] using electron microscopy . in freeze - fracture replicas of quick - frozen samples ,
ptdins(3,5)p2 was labeled specifically using recombinant atg18 tagged with glutathione s - transferase and 4flag , which was mixed with an excess of recombinant px domain to suppress binding of atg18 to phosphatidylinositol 3-phosphate . using this method ,
ptdins(3,5)p2 was found to be enriched in limited domains in the yeast vacuole and mammalian endosomes . in the yeast vacuole exposed to hyperosmolar stress ,
ptdins(3,5)p2 was distributed at a significantly higher density in the intramembrane particle ( imp)-deficient liquid - ordered domains than in the surrounding imp - rich domains . in mammalian cells
, ptdins(3,5)p2 was observed in endosomes of tubulo - vesicular morphology labeled for rab5 or rab7 .
notably , distribution density of ptdins(3,5)p2 in the endosome was significantly higher in the vesicular portion than in the tubular portion .
the nano - scale distribution of ptdins(3,5)p2 revealed in the present study is important to understand its functional roles in the vacuole and endosomes . |
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: the 90% of fish international market is based on processed products , but live crustaceans , especially clawed and spiny lobsters , crabs , marine and freshwater prawns and freshwater crayfish , are really appreciated for their high nutritional and commercial importance ( fotedar and evans , 2011 ) .
the american lobster , homarus americanus , is one of the most important commercial species marketed internationally and one of the major economic resource of the coastal communities of north america , with more than 130,000 tons of alive animals commercialised worldwide in 2006 and producing nearly 545 million of euros of profits . due to the decrease of the european lobster homarus gammarus catching figures ,
american lobsters are imported by several european countries , especially mediterranean ones : in italy about 4387 tons are annually introduced for an economic value of 44 million of euros ( barrento et al .
american lobsters are mainly commercialised alive and cooked before consumption . after the capture and during the air transport , they are submitted to several stresses like air exposure , changes of the natural environments in terms of physical and chemical parameters such as water salinity and temperature , hypoxia , fasting , interactions with other conspecifics and human handling .
these stressors can affect their health , reducing their quality , and in some cases could be lethal .
opposite opinions are still existing about the edibility of lobsters dead during air shipping : some sellers reject to sale the dead subjects , some others use these ones for cooked products , others sell these animals depreciated . at the moment there are no available studies about the hygienic quality of the living and dead animals , in terms of presence of potential pathogenic bacteria and of microbial populations .
however , we could suppose that the loads and the typology of microbiota of lobsters reflect a combination of factors including the environment where they are captured , their feeding and living practices , the season of capture as well as the quality and temperature of the waters where they lived , as already demonstrated for other crustaceans and for finfish ( liston , 1980 ; shewan , 1977 ) .
after death , once the immune response fails to function and the muscular structure declines due to microbial activity , the alteration begins quickly : generally this situation does not expose consumer to microbiological risks as these animals are mainly consumed after cooking .
however , the increasing demand for ready - to - eat raw or cooked crustaceans and of fresh lobster tails could enhance the risk posed by these products , if subjected to improper storage or poor hygienic practices during production and commercialisation .
( 1980 ) found high total bacterial count values [ more than 5 log colony forming unit ( cfu)/g ] in 51.9% of frozen lobster tails samples , even if very low levels of coliforms and e. coli were detected .
although , as already mentioned , no studies till now were conducted on lobster meat bacterial population , generally the microbiota of crustaceans captured in temperate waters includes pseudomonas spp . , shewanella putrefaciens and members of the group acinetobacter - psychrobacter ( gram and huss , 1996 ) .
aim of our study was the microbial evaluation of the meat of american lobsters not surviving the air shipping from the harvest ( usa ) to a seafood distribution platform of an international wholesaler , located in northern italy , and the identification of the most representative bacterial populations in order to establish the major genera / species involved with microbial spoilage of these products .
we also evaluated the microbial loads of gut and gills as possible sources of contamination .
for this study , eighteen lobsters arrived dead after air transport lasted about 24 h from harvest ( usa ) to the seafood distribution platform , were collected .
the subjects were transported at refrigeration temperatures in cardboard boxes containing ice gel packs where they were maintained separately thanks to cardboard dividers .
the dead subjects were transported under refrigerated conditions to the laboratory where they were analysed immediately .
aseptically , gills , meat and intestine were withdrawn and submitted to microbiological analyses : 5 - 10 g of each sample were diluted 1:10 in saline diluent ( nacl 10 g / l , mgso47h2o 1.53 g / l , mgcl26h2o 1.28 g / l , kcl 0.19 g / l , tryptone 1
g / l ) and serial 10-fold dilutions were prepared . total viable count ( tvc ) was enumerated onto modified tryptose agar as described by bernardi et al .
( 2015 ) , incubated at 20c for 72 h. the number of enterobacteriaceae was determined according with iso 21528 - 2:2004 method ( iso , 2004 ) .
colonies of fluorescent pseudomonads were observed on plates of king s b agar ( king et al . , 1954 ) in ultraviolet light , after growth for 1 - 3 days at 20c .
bioluminescent bacteria were enumerated onto glycerol based marine agar ( gma ) ( makemson et al . , 1992 ) ; plates were incubated at 20c for 72 h and observed daily in dark .
finally h2s producing microorganisms were enumerated onto iron agar containing sodium thiosulphate ( ia1 following gram et al . ,
plates were incubated at 20c for 72 h and observed for black colonies . from the tvc plates of meat samples ,
a number of five colonies for each of 12 subjects ( identified with code from a to n ) were randomly picked and subcultured onto modified tryptose agar .
cytochrome - oxidase was tested with the method described by kovacs ( 1956 ) and catalase formation with 3% h2o2 .
the carbohydrate metabolism was observed in tubes of hugh and leifson medium ( hugh and leifson , 1953 ) .
tubes were stab inoculated ( after boiling to avoid oxygen ) and incubated at 20c for a week .
fermentative bacteria produced acid from glucose , changing the color of the indicator from green to yellow , in all the volume of the medium .
oxidative bacteria grew only on the surface of the medium , and the eventual change of color ( blue due to alcalinisation or yellow for acidification ) was located within 2 - 3 cm from the surface .
proteolytic activity was detected by gelatin hydrolysis on frazier s agar plates ( frazier , 1926 ) .
the inoculated plates were incubated at 20c for a week , than flooded with frazier s reactive .
lipolytic activity was assessed on sierra s agar containing tween 80 ( sierra , 1957 ) .
the plates were incubated at 20c for a week ; positive strains showed a visible precipitation around the colonies .
the medium used was iron agar 1 ( gram et al . , 1987 ) ; each plate was prepared with 40 ml of agar stab inoculated .
h2s production was indicated by the formation of a black precipitate of fes . to enable
the growth of halophilic microorganisms , the original composition of some media ( iron agar 1 ) were added of the following final salt concentrations : nacl 10 g / l , mgso47h2o 1.53 g / l , mgcl26h2o 1.28 g / l , kcl 0.19
g / l . the ability to growth at 5 , 30 , 37 and 42c
moreover the ability to grow onto modified tryptose agar including different salt concentration ( 0 and 0.5% ) was evaluated preparing the plates with the different percentages of salt included .
isolates were then identified by 16s rrna gene sequencing ( eurofins , berlin , germany ) using the standard forward primers cc - cd as described by rudi et al .
the sequences were analysed and compared to bibi and ncbi - blast ( http://blast.ncbi.nlm.nih.gov/blast.cgi ) databases and the closest type strains relatives based on partial 16s rrna gene sequences were determined . in order to verify
if the number of identified taxa was representative of the whole microbial species present in the ecological niche of american lobsters meat , the total number of bacterial species and the percentage detected were estimated by method described by chao et al .
for this study , eighteen lobsters arrived dead after air transport lasted about 24 h from harvest ( usa ) to the seafood distribution platform , were collected .
the subjects were transported at refrigeration temperatures in cardboard boxes containing ice gel packs where they were maintained separately thanks to cardboard dividers .
the dead subjects were transported under refrigerated conditions to the laboratory where they were analysed immediately .
aseptically , gills , meat and intestine were withdrawn and submitted to microbiological analyses : 5 - 10 g of each sample were diluted 1:10 in saline diluent ( nacl 10 g / l , mgso47h2o 1.53 g / l , mgcl26h2o 1.28 g / l , kcl 0.19 g / l , tryptone 1
g / l ) and serial 10-fold dilutions were prepared . total viable count ( tvc ) was enumerated onto modified tryptose agar as described by bernardi et al .
( 2015 ) , incubated at 20c for 72 h. the number of enterobacteriaceae was determined according with iso 21528 - 2:2004 method ( iso , 2004 ) .
colonies of fluorescent pseudomonads were observed on plates of king s b agar ( king et al . , 1954 ) in ultraviolet light , after growth for 1 - 3 days at 20c .
bioluminescent bacteria were enumerated onto glycerol based marine agar ( gma ) ( makemson et al . , 1992 ) ; plates were incubated at 20c for 72 h and observed daily in dark .
finally h2s producing microorganisms were enumerated onto iron agar containing sodium thiosulphate ( ia1 following gram et al . ,
from the tvc plates of meat samples , a number of five colonies for each of 12 subjects ( identified with code from a to n ) were randomly picked and subcultured onto modified tryptose agar .
the total of 60 isolates were afterwards submitted to the tests as described below . the following reactions and biochemical tests were used for the characterisation of the isolates .
cytochrome - oxidase was tested with the method described by kovacs ( 1956 ) and catalase formation with 3% h2o2 .
the carbohydrate metabolism was observed in tubes of hugh and leifson medium ( hugh and leifson , 1953 ) .
tubes were stab inoculated ( after boiling to avoid oxygen ) and incubated at 20c for a week .
fermentative bacteria produced acid from glucose , changing the color of the indicator from green to yellow , in all the volume of the medium .
oxidative bacteria grew only on the surface of the medium , and the eventual change of color ( blue due to alcalinisation or yellow for acidification ) was located within 2 - 3 cm from the surface .
proteolytic activity was detected by gelatin hydrolysis on frazier s agar plates ( frazier , 1926 ) .
the inoculated plates were incubated at 20c for a week , than flooded with frazier s reactive .
lipolytic activity was assessed on sierra s agar containing tween 80 ( sierra , 1957 ) .
the plates were incubated at 20c for a week ; positive strains showed a visible precipitation around the colonies .
the medium used was iron agar 1 ( gram et al . , 1987 ) ; each plate was prepared with 40 ml of agar stab inoculated .
h2s production was indicated by the formation of a black precipitate of fes . to enable
the growth of halophilic microorganisms , the original composition of some media ( iron agar 1 ) were added of the following final salt concentrations : nacl 10 g / l , mgso47h2o 1.53 g / l , mgcl26h2o 1.28 g / l , kcl 0.19
g / l . the ability to growth at 5 , 30 , 37 and 42c
moreover the ability to grow onto modified tryptose agar including different salt concentration ( 0 and 0.5% ) was evaluated preparing the plates with the different percentages of salt included .
isolates were then identified by 16s rrna gene sequencing ( eurofins , berlin , germany ) using the standard forward primers cc - cd as described by rudi et al .
the sequences were analysed and compared to bibi and ncbi - blast ( http://blast.ncbi.nlm.nih.gov/blast.cgi ) databases and the closest type strains relatives based on partial 16s rrna gene sequences were determined . in order to verify
if the number of identified taxa was representative of the whole microbial species present in the ecological niche of american lobsters meat , the total number of bacterial species and the percentage detected were estimated by method described by chao et al .
a total of 18 lobsters dead during shipping were analysed : meat , gills ( as the main access point for bacteria ) and gut bacterial contaminations were screened .
the food and drug administration ( fda , 2013 ) , which has issued guidelines in order to define the microbiological quality of some food categories , indicates in 6 log cfu / g the microbiological limit for crustaceans raw meat .
there are no specific studies about the microbiological quality of american lobsters meat ; studies are available on frozen crabs meat ( icmsf , 1998 ) , indicating that counts below 5 log cfu / g can be considered satisfactory , while those comprised between 5 and 6 log cfu / g should be considered fairly satisfactory .
moreover , for fish products , the threshold value used to identify the end of the shelf - life is often 6 log cfu / g ( olafsdottir et al . , 2005 ) , even if the total bacterial count at the point of rejection can be around 7 - 8 log cfu / g ( espe et al . , 2004 ) .
generally , the values obtained from our raw meat samples were characterised by limited loads : the average was below 5 log cfu / g , confirming a good hygienic quality , while only two samples resulted to exceed the 6 log level ( 6.21 and 6.38 log cfu / g ) ( table 1 ) .
as expected , gills and guts were characterised by higher loads : in the intestine this is due to the presence of a great amount of bacteria which constitute the natural microbiota , while the gills were identified as the main point of access of the bacteria from the outside due to the peculiar anatomical structure that allows gaseous exchanges .
these loads , in any case , do not represent a hygienic problem as the product is generally consumed after a thermal treatment .
however , in order to avoid the cross contamination between raw products during the preparation , the good manufacturing and hygienic practices should be always applied . concerning the other parameters evaluated , all the counts of meat samples resulted low ( average values of bioluminescent and h2s producing bacteria were always below 4 log cfu / g ) . considering h2s producing bacteria , typical spoiler of fish products ,
although the loads detected in meat samples do not reach high levels , they should be carefully considered , due to their potential replication during the incidental further storage at low temperatures .
considering enterobacteriaceae and fluorescent pseudomonads , all the samples were below the detection limit ( 2 log cfu / g ) .
the absence of detectable counts of fluorescent pseudomonads was unexpected , as these microorganisms are common contaminants of marine fishes ( huss , 1995 ) . in order to understand the ecology of the strains grown on the plates of the total viable count of meat samples ,
some phenotypic traits were considered : the 43.1% resulted to ferment glucose while the remaining 56.9% to be oxidative .
considering the ability to grow at different temperatures , the psychrotrophic nature of the microbiota was evidenced , even if the ability to adapt to higher temperatures was also observed .
in fact , all the isolates grew at refrigerated temperatures ( 5c ) , the 46.6% of the isolates was able to grow at 30c while only the 3.4% resulted to be able to grow at 37c and none of the isolates was able to grow at 42c . taking in account the salt requirement ,
the 82.8% of isolates resulted to be able to grow at 0.5% of salinity , while only the 24.1% at 0% , evidencing that the main lobster bacterial population is composed by halotolerant and halophilic microorganisms . from the 60 isolates randomly picked from the plates of meat samples
: this is one of the largest genera within the gammaproteobacteria and currently comprises more than 30 species ( ivanova et al . , 2004 ) .
these microorganisms are characterised by a widespread distribution across many marine habitats ( e.g. , seawater , rocks , macroalgae and marine animals ) and are able to survive in poor nutrient substrates producing a varied range of metabolites and enzymes ( ivanova et al . , 2003 ) .
the phylogenetic structure of this group indicates that the non - pigmented species are strictly related among them and constitute the major cluster of the genus . in our case
: 20 isolates ( 80% ) resulted to be closely related to the species ps .
our sequences did not allow the distinction of one of these 4 species due to the high similarity existing among them .
, genus that comprises 19 species , five of those containing luminous strains ( ph . phosphoreum , ph .
leiognathi ) : all these bacteria are commonly present in marine environments and occur in seawater , surfaces and gut of marine animals , marine sediments and saline lake water , as well as in the organs of fishes ( baumann and baumann , 1984 ; dalgaard , 1995 ; urbanczyk et al . , 2011 ) .
frigidiphilum , a psychrophilic and weakly halophilic strain , firstly isolated and identified from deep - sea sediments of edison seamount ( seo et al . , 2005 ) .
kishitani : for two isolates the species was confirmed with both the alignment tools while for five of them the species indicated in blast algorithm differed and resulted as ph .
piscicola , a recent new one ( figge et al . , 2014 ) , not yet included in the lebibi data bank .
aquimaris and one resulted to be similar with the same score to both the species ph . kishitani and ph .
( 2009 ) , who firstly identified the latter species , these two are recognised to be very closely related from a genetic point of view .
arctica , firstly identified in 2002 : these cold - adapted microorganisms could be isolated from permanently but also temporarily cold locations ( e.g. , oceans , polar regions , high mountains , deep lakes ) , and are often associated with plants and fresh and cold blooded fishes and crustaceans ( groudieva et al . ,
( 6.9% of the whole ) : these microorganisms are usually halotolerant and psychrophilic and are linked to several different substrates like fish skin , gills and gut , sea water but also lamb carcasses ( bowman et al .
, 1997b ; gonzalez et al . , 2000 ; prieto et al . , 1992 ) .
two of these isolates resulted to be related to p. pulmonis , the only species not related to marine environment as firstly isolated and identified in 2002 from a pure culture from lung clinical specimen of lambs .
another one resulted to be close to p. submarinus , firstly isolated from sea water ( romanenko et al . , 2002 ) and another one to p. piscatorii / nivimaris , species firstly isolated from a drain of a fish - processing plant ( yumoto et al . ,
2010 ) and from samples of the southern ocean environment ( heuchert et al . , 2004 ) . as shown by yumoto et al .
( 2010 ) , the two species p. piscatorii and p. nivimaris have a deep genetic relatedness .
( 5.2% ) : one resulted to be related to vibrio lentus , firstly isolated from mediterranean oysters ( macian et al . ,
2001 ) , and the other to vibrio rumoiensis , firstly isolated from drain pool of a fish product processing plant ( yumoto et al . , 2013 ) .
the third isolate was close to v. rumoiensis / litoralis : these two species are considered strictly related , as observed by nam et al .
some species of vibrio ( vibrio vulnificus and v. parahaemolyticus in particular ) are primary causes of human mortality and illness due to gastroenteritis or septicemia through consumption of raw or undercooked seafood or from wound infections ( constantin de magny et al .
the majority of v. vulnificus and v. parahaemolyticus illnesses are often related with shellfish consumption ; nevertheless , these bacteria can also be found in fish , sediment , plankton and marine water : in our study we did not focus on the presence and isolation of pathogenic bacteria , such as vibrio spp .
, thus the colonies identified were isolated from a non - selective medium used for the enumeration of total viable count , and not from a specific medium for the isolation of these bacteria .
: one resulted to be similar to the species s. vesiculosa , firstly isolated from marine sediments collected at deception island , and s. livingstonensis , firstly isolated from antarctic coastal marine environments ( bozal et al . , 2002 ; 2009 ) .
the other strain was related to shewanella arctica / frigidimarina , firstly isolated respectively from arctic marine sediment in a fjord branch in norway and from sea ice from antarctic meromictic lakes ( bowman et al .
: one as pseudomonas sabulinigri , firstly isolated from black sand collected from korea ( kim et al . ,
the remaining two isolates were identified as alivibrio logei / salmonicida , two psychrophilic species whose substantial similarities were highlighted by multigenic analysis ( ast et al . ,
2009 ) , and as polaribacter sejongensis / butkevichii firstly isolated from antarctic soil and from sea water collected in the sea of japan ( kim et al . , 2013 ; nedashkovskaya et al . , 2005 ) . keeping into account only unique identifications , total number of bacterial species
was 68 : the 13 unique species observed are nearly 19% of total number of species .
nevertheless , considering ambiguous identifications , an algorithm was build up and performed in sas software ( sas institute , cary , nc , usa ) by which , the estimates were calculated for 100,000 random possible species compositions of a sample . according with this simulation ,
the highest value found for number of bacterial species was 53 , while the mean number was 37 .
number of total bacterial species colonising lobster meat calculated according only unique identifications should be considered as an over - estimation : as a consequence , values coming from simulation are better estimates of such species richness .
in fact most of the microbial spoilage population found was composed by the same genera vibrio spp .
in particular , the most prevalent genus in american lobsters was pseudoalteromonas spp . , while only few vibrio spp .
were found , while in norway lobsters , vibrio spp . represented more than half of the isolates and only 14.6% belonged to the genus pseudoalteromonas .
considering the genera identified , a clear inhomogeneity in the samples distribution was observed with some of them showing a strict prevalence of pseudoalteromonas spp .
( e.g. , subjects code a , d , h , i , m ) and some others of photobacterium spp .
a single subject is not reflecting the microbial population of all the conspecifics and consequently it is quite difficult to predict the development of the spoilage microbiota in this product . in any case , all the identified spoilage microorganisms were common natural marine bacteria , and no important post - harvest contamination by not halophilic bacteria , due to handling or cross contamination , was evidenced .
all the genera , apart from vibrio spp . , are microbial spoilers of seafood ( dalgaard , 2000 ; gram and huss , 1996 ; gram et al .
all the isolates were screened for their proteolytic and lipolytic ability ( table 3 ) , showing the wide diffusion of metabolically active strains .
in particular , all pseudoalteromonas spp . isolates resulted to possess lipolytic abilities and also proteolytic capabilities .
none of the isolates in this study showed the ability to produce h2s : this finding is in agreement with the data obtained from fresh norway lobsters ( gornik et al . , 2011 ) where all the isolates showed not to possess this capability .
to our knowledge , no specific studies have been conducted so far about the microbiological quality of american lobsters meat in terms of spoilage microbial population .
the genera isolated from meat samples , mostly characterised by marine pseudoalteromonas spp . and photobacterium spp .
, could be considered rapresentative of the microbiota of not - surviving subjects , but our data could also reflect the microbial environment of live lobsters , transported and stored in similar conditions .
the evaluation of not surviving lobsters is of particular concern as they could be an optimal substrate for the growth of spoilage bacteria .
our samples showed very limited microbial loads , suggesting the possibility to commercialise these subjects without particular quality faults for the consumers .
the application of good hygienical practices , especially during the production of ready - to - eat lobsters - based products , and a proper ice storage could limit the possible replication of these microorganisms . | ### Summary:
: eighteen american lobsters ( homarus americanus ) , dead during air transport , were analysed in order to evaluate the microbial population of meat , gills and gut : no specific studies have ever been conducted so far on the microbiological quality of american lobsters meats in terms of spoilage microbiota .
the meat samples showed very limited total viable counts , in almost all the cases below the level of 6 log cfu / g , while higher loads were found , as expected , in gut and gills , the most probable source of contamination .
these data could justify the possibility to commercialise these not - surviving subjects , without quality concerns for the consumers .
most of the isolates resulted to be clustered with type strains of pseudoalteromonas spp .
( 43.1% ) and photobacterium spp .
( 24.1% ) , and in particular to species related to the natural marine environment .
the distribution of the genera showed a marked inhomogeneity among the samples .
the majority of the isolates identified resulted to possess proteolytic ( 69.3% ) and lipolytic ability ( 75.5% ) , suggesting their potential spoilage ability .
the maintanance of good hygienical practices , especially during the production of ready - to - eat lobsters - based products , and a proper storage could limit the possible replication of these microorganisms . |
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: older adults often report that they are concerned about their memory and some bring these complaints to their primary care providers ( pcps ) .
estimates of the prevalence of subjective memory complaints ( smcs ) vary but are generally high , ranging from approximately 25% to 50% .
since a feeling of failing memory can be accompanied by psychological distress and worry , pcps must be equipped to respond to questions about the meaning and relative importance of these complaints .
for example , smcs could have prognostic value in predicting objective memory decline and dementia [ 2 , 3 ] .
there is evidence that measures of subjective and objective memory are correlated , but the magnitude of the association is usually small .
sociodemographic variables , such as age , education , and gender , also have been reported as predictors of smcs .
older adults , women , and those with less education more often report smcs than younger adults , men , and those with more education .
this may be because advancing age is associated with cognitive impairment ; women , more often than men , report their health concerns ; and those with more education may be better able to accurately appraise their cognitive functioning than those with less education [ 1 , 4 ] .
. this may be due to the tendency of persons with depression or depressive symptoms to exaggerate their deficiencies .
some authors have pointed to the possible moderating effects of sociodemographic variables on the association between objective memory problems and smcs [ 1 , 4 ] .
for example , older adults ' assessments of their memory functioning may be influenced by a belief that memory declines with age , leading them to magnify any problems they do have .
on the other hand , younger adults may be less influenced by such an expectancy , resulting in more accurate appraisals of their own objective memory functioning .
similarly , adults with less education may be affected more by this kind of expectancy than adults with more education , regardless of their age .
thus adults with more education may be better able to appraise their own objective memory functioning .
empirically , these relationships would be shown through statistical interactions between variables assessing objective memory and sociodemographic variables .
however , surprisingly few studies have directly tested for interaction effects between objective memory and sociodemographic variables to examine their impact on risk for smcs .
further , previous studies are limited by the sampling strategy . studies with subjects drawn from memory clinics are biased in favor of finding a higher prevalence of smcs because the respondents are more likely to have objective memory deficits . on the other hand ,
population - based studies may be biased in favor of finding a lower prevalence of smcs because respondents are generally healthier and more willing to participate in research . however , in studies using telephone screening , persons with memory deficits might be less likely to refuse participation , thereby including a more representative sample of individuals having a range of memory abilities who are willing to participate in research .
importantly , relatively little is known about the cognitive bases of smcs . while deficits in memory may well be the major source of smcs
attention , efficiency of information processing , and verbal skill each plays a unique role in the formation of memories .
thus , specific deficits in verbal functioning , attention , and processing speed could each independently increase the risk of smcs .
however , little is known about the relative and independent contributions of deficits in specific domains of cognitive functioning , as well as global cognitive functioning , to risk for smcs .
some authors have used psychometrically validated scales ( e.g. , the memory functioning questionnaire ) to assess the extent and frequency of memory complaints , but others have used single - item rating scales .
we wondered whether there would be agreement between participants ' beliefs about their own memory function and their perceptions of what others such as family and friends think about their memory function .
anecdotally , we know that persons with hearing loss often claim that the degree of loss is less than what family members perceive and report .
a similar phenomenon may occur when assessing smcs from the vantage point of the subject and also from the vantage point of the subject 's perceptions of what family members think .
these two assessments of smcs may agree or disagree , but little is known about this . in the present research , we used telephone interviews to screen for smcs in a sample of persons in the age of 65 and older living in cuyahoga county , ohio .
one focused on subjects ' perceptions of their memory , and another focused on subjects ' perceptions of evaluations by family members .
we also assessed objective cognitive functioning with tests of episodic memory , verbal fluency , processing speed , and global cognitive functioning . because we expected that most of our research volunteers would have self - awareness allowing them to encode instances of memory problems and have introspective access to that information
, we predicted that deficits in objective memory would be associated with increased risk for smcs .
however , we predicted that there would not be an effect on risk for smcs as a function of deficits in verbal fluency , processing speed , and global cognitive functioning , since we did not expect that subjects would attribute deficits in these domains to memory functioning .
we further predicted that there would be significant interactive effects between objective memory and the sociodemographic variables .
based on logic outlined earlier , we hypothesized that there would be statistically significant interactions between ( 1 ) age and memory , such that better objective memory would be associated with lower risk for smcs in younger adults , but not in older adults ; ( 2 ) education and memory , such that better objective memory would be associated with lower risk for smcs in better - educated adults , but not in less - educated adults ; and ( 3 ) gender and memory , such that objective memory would be associated with greater risk for smcs in women than men .
we did not predict that there would be significant interactions between the sociodemographic variables and other domains of cognitive functioning .
this study is based on data from the cleveland area telephone survey ( cats ) , a population - based study of cognitive aging and dementia initiated in 2002 . in the cats ,
telephone interviews were used to gather cognitive data on a sample of approximately 500 community - dwelling adults , age 65 and older , living in cuyahoga county in northeastern ohio .
the study was mainly designed to examine the feasibility of generating a representative sample for future epidemiologic studies involving assessment of memory and cognition in older adults .
study procedures associated with this project were reviewed and approved by the institutional review board ( irb ) for human investigation of university hospitals of cleveland ( irb 07 - 02 - 02 ) .
the irb approved the study with a waiver of documented consent according to 45 cfr 46.117(c)(2 ) .
potential subjects were told that they would soon receive a telephone call from a research assistant ( ra ) working at the university memory and aging center , affiliated with university hospitals of cleveland and case western reserve university .
the letter outlined , in general , the following : ( 1 ) the purposes of the project ; ( 2 ) its risks and benefits ; ( 3 ) that study results would be reported in an aggregated form so that no person or persons could ever be identified in publications or reports ; and ( 4 ) that the participants could withdraw from the study at any time .
when the ra telephoned the potential subject and if the person agreed to participate , the study procedures , risks and benefits , and voluntary and confidential nature of the study were all described again .
if verbal consent was given , the subjects ' willingness to participate in the research was recorded in a data manual by i d number and stored in a locked file cabinet . by contrast , if a subject indicated that he or she did not wish to participate , their refusal was also recorded .
the person was thanked for their time , and the ra removed their name and any other identifying information from our list of potential participants .
the target population consisted of residents of households in cuyahoga county with listed telephone numbers who were of age 65 and older in 2002 .
the population was limited to households with listed numbers for two reasons : ( 1 ) the households ' addresses could be obtained so that we could send them a letter describing the study before calling them to conduct the telephone interview ; ( 2 ) knowledge of the telephone number and the name of the householder listed in the telephone directory made it possible to select a sample of households that were known or expected to have at least one resident who was 65 or older .
households expected to have at least one person of age 65 or older were used to reduce the need for extensive screening for older persons that would be required if a random - digit - dialed survey of all households with telephones had been conducted .
( note that data for this study were collected in 2002 - 2003 , when mobile phones were less prevalent . at this time , land lines were still in use to a great degree ; thus our telephonic approach for sampling was reasonable at that time . ) a randomly selected list of households that were likely to meet our inclusion criteria was provided by survey sampling , inc.a leader in its field with over 25 years of experience .
gathers data on age , education , race , gender , and income through contests , warranty cards , phone solicitation , and other means . for households with missing data ,
regression models are used to estimate whether or not there was someone of age 65 or older in the household .
some time later , ras , trained in basic interviewing techniques , neuropsychological test administration , data management , and subject confidentiality , telephoned the households .
after a brief introduction , the ra asked if there was anyone of age 65 or older living in the household . if there was more than one person of age 65 or older in the household , the ra asked for the householder who was oldest , next oldest , next youngest , or youngest , depending on the number of persons of age 65 or older and a prespecified randomization scheme .
after the selection of the subject , verbal consent was obtained and the ra proceeded with the survey .
of the 1,897 households we attempted to contact , 350 were ineligible ( e.g. , no one of age 65 or older , undeliverable letter , or potential subject deceased or impaired too much ) . of the remaining 1,547 households ,
this was a conservative estimate because we assumed that the 249 households where there was no answer after three calls may have contained eligible subjects .
our completion rate , indicating how successful we were in completing an interview when an eligible household was contacted , was 38.7% . before responding to the questions
, participants were asked whether they had hearing impairments ( yes was coded as 1 , and no was coded as 0 ) .
subjects who reported hearing impairments and who had hearing devices were encouraged to use them .
the interviewer asked if there were others in the room or if a television or radio were on .
if so , the subject was asked to go to a quiet room with a telephone to be interviewed . among subjects who participated in the study , the mean age was 75.7 years ( sd = 6.4 ) ;
62.2% were women ; and 83.0% were caucasian ( most of the minority participants were african americans ) .
the mean years of education attained by subjects in the study sample were 13.2 ( sd = 3.0 ) .
approximately 18% had less than 12 years of education , 36% had a high school diploma , and 45% had more than 12 years of education ( values do not sum to 100% due to rounding ) . according to data gathered for the 2000 us census ,
15% of persons living in cuyahoga county were 65 years and older ( n = 217,177 ) . among these ,
approximately 35% of residents of cuyahoga county , of age 65 and older , had less than 12 years of education , 34% had a high school diploma , and 31% had more than 12 years of education .
thus , when comparing the older population in cuyahoga county to our study sample , we see that our study sample overrepresented caucasians and persons with higher education .
would you say that you have a serious problem with your memory ( coded as 2 ) , that your memory is somewhat of a problem ( coded as 1 ) , or that it is not much of a problem ( coded as 0 ) ?
subjects were then asked what they thought others think about their memory : do other people find that you are often forgetful ( coded as 2 ) , sometimes forgetful ( coded as 1 ) , or seldom if ever forgetful ( coded as 0 ) ? global cognitive functioning was evaluated with a modified version of the telephone interview for cognitive status ( tics - m ) .
this instrument was developed as a telephone version of the mini - mental state examination ( mmse ) .
the tics - m tests function in several domains : concentration , orientation , memory , naming , comprehension , and abstraction .
the tics - m is reliable , with a high test - retest correlation over 18 months ( r = .83 ) .
the tics - m correlates highly with the mmse ( r = .80 ) , indicating its validity as a measure of global cognitive functioning . because the tics - m is heavily weighted towards assessing memory ( 20 of the 50 items are memory items ) , we modified the instrument to exclude the memory items . with the exclusion of the memory items , scores on
the test could range from 0 to 30 , with higher scores indicating better performance .
the hopkins verbal learning test ( hvlt ) is a list - learning and memory test .
a word - list is made up of 3 groups of 4 words belonging to different conceptual categories .
the hvlt is easy to administer and can be used in normal and clinically impaired populations , such as alzheimer 's disease ( ad ) . for total recall ,
test - retest reliability , measured over a 9-month interval , has been reported as good ( r = .50 ) .
validity has been shown through correlations with the logical memory subtests ( immediate and delayed recall ) of the wechsler memory battery ( r = .75 and r = .77 , respectively ) .
scores on the test range from 0 to 36 , with higher scores indicating better performance .
verbal fluency was assessed through animal naming , in which subjects are asked to name as many animals as possible in one minute .
verbal fluency scores reflect the total number of animals named in one minute , with high scores indicating better performance . in the timed months of the year backwards
( tmyb ) test , subjects are asked to say the months of the year backwards , starting with december .
according to research by the authors of the test , reliability , assessed with a test - retest correlation obtained one week to ten days later , is high , with r = .90 .
construct validity is also high , when assessed with correlations between tmyb and measures of simple reaction time ( r = .52 ) and choice reaction time ( r = .51 ) and the trails b test ( r = .45 ) .
subjects were asked to report whether a doctor had ever diagnosed them with a memory problem , and they were also asked whether parents , brother(s ) , sisters(s ) , or children had ever been diagnosed with a condition causing a memory problem .
responses were coded as 1 for yes and 0 for no for both questions . because few people reported that they had a serious memory problem , while relatively more reported that they had somewhat of a problem , these two categories were combined , resulting in a dichotomous outcome variable ( 1 = smc present , 0 = smc absent ) .
the same recoding was done for the variable reflecting how subjects felt that others would evaluate their memory .
binary logistic regression analysis was used to model the presence of smcs as a function of several predictor variables : cognitive variables ( episodic memory function [ hvlt ] ; verbal fluency [ animal naming ] ; processing speed [ tmyb ] ) ; self - reported clinical history of memory problems ( physician 's diagnosis ; family history ) ; and sociodemographic variables ( age , education , and gender ) .
interactions between the cognitive variables with age , education , and gender were also examined .
significant predictors were centered about their respective means to make the regression coefficients for the cognitive variables , age , and education more meaningful .
the prevalence of memory complaints , stratified by age and education level , is shown in table 1 .
overall , 26.5% of subjects reported that their memory is somewhat of a problem , while 0.6% reported that they have a serious problem with their memory .
persons 75 years and older with 12 years of education had the highest reported prevalence of smcs ( 35.5% ) , while persons of age 65 to 74 with 13 or more years of education had the lowest reported prevalence of smcs ( 20.2% ) . in terms of others ' perceptions
, 36.0% of subjects indicated that others thought the subjects were sometimes forgetful , while 2.3% reported that others thought they were often forgetful .
persons of age 65 to 74 with less than 12 years of education most often reported that others thought the subject had a memory problem ( 48.6% ) , while persons of age 75 and older with 13 or more years of education least often reported that others thought the subject had a memory problem ( 31.3% ) .
interestingly , table 1 also shows that those who were older less often reported a family history of memory loss , while increasing education was associated with reports of decreasing memory impairment diagnoses . in table 2
, we present results of a logistic regression analysis , with subjects ' subjective perceptions of their memory as the dependent measure .
predictor variables in the model were sociodemographic and clinical variables , cognitive measures , and terms for the interaction of cognitive variables with age , education , and gender .
table 2 indicates significant main effects of education , hearing ability , a diagnosed memory problem , global cognitive function ( tics - m ) , and memory ( hvlt ) on smcs .
the memory age interaction was significant ( or = 1.007 , 95% ci = 1.0011.012 ) . among the younger - old , better
objective memory performance was associated with lower risk for smcs , while among the older - old better memory had no effect on risk . the tics
- m education interaction was also significant ( or = .976 , 95% ci = .940.995 ) . among those with more education , better global cognitive functioning
was associated with lower risk of a smc , while among those with less education , better global cognitive functioning had no effect on smc risk .
figures 1 and 2 show these complex relationships in graphical form . in figure 1 , we depict the chances of reporting a smc as a function of the interactions between age and performance on our memory test , the hvlt .
the specific ages shown in figure 1 represent the range of ages in our study ( 66 through 90 ) and two frequently occurring ages in our data set ( 74 and 82 ) .
the x - axis represents memory performance , with higher scores indicating better memory performance and lower scores indicating relatively poorer performance .
figure 1 shows that , depending on one 's age , objective memory performance on our memory test predicted the chances of participants reporting a subjective memory complaint . for those with good memory ( e.g. , a score of 30 on the hvlt ) , the chances of reporting a subjective memory complaint were lower for those who were younger ( e.g. , 66 or 74 ) than for those who were older ( e.g. , 82 or 90 )
however , the pattern reverses quite dramatically for people who , when tested , had poor objective memory performance .
for those with a very low memory score ( e.g. , 6 on the hvlt ) , the probability of reporting a memory complaint was greater for those who were younger ( 66 or 74 ) than for those who were older . in figure 2
, the x - axis depicts performance on the tics - m , our measure of overall cognitive ability .
figure 2 shows in graphical form that poor overall cognitive functioning for example , a score of 6 on the tics - m was associated with vast differences by educational level in the probability that a subject would report a subjective memory complaint .
for example , for a person who completed 8 years of education and had a score of 6 on the tics - m ( meaning their cognitive functioning was very poor ) , the probability that they would report having a memory complaint was very low .
by contrast , for those who completed relatively higher levels of educational attainment ( e.g. , 16 years , i.e. , college graduates ) and also had poor overall cognitive functioning ( e.g. , 6 on the tics - m ) , the chances that they would report having a memory problem were far higher . for persons whose cognitive performance was relatively better ( e.g. , 24 on the tics - m ) , educational attainment level mattered less in determining whether a person would report a subjective memory complaint .
thus , for those who were cognitively intact , their educational attainment level was far less important in determining differences in the chances of reporting a memory complaint . to summarize , for those with poor overall cognitive functioning , educational attainment level greatly influenced the chances of reporting a memory complaint but for those with good cognitive functioning educational level had little or no influence on memory complaints .
in table 3 , we present results of a second logistic regression analysis , where participants ' perception of others ' beliefs about the participants ' memory functioning was the dependent measure .
none of the interactions of the cognitive and sociodemographic variables were significant in this model , so they were removed .
table 3 indicates that better performance on the hvlt was associated with decreased odds of expectations that others would report memory impairments in our research volunteers .
there are three major findings emerging from the present research . first , in a sample of community - dwelling , older adults , the prevalence of smcs was high , greater than 25% .
this value is generally consistent with those reported in population - based studies but lower than those reported in many clinic - based studies .
second , we documented important statistical interactions between some of the cognitive and sociodemographic variables . specifically , we found that objective memory performance was related to lower risk for smcs , but these relationships were strongest for the younger - old .
global cognitive functioning was associated with a lower risk for smcs for those with higher levels of education .
this may be because , in assessing their own memory functioning , the older - old and those with less education tend to be influenced by a belief that memory declines with age , leading these subject groups to magnify any problems they may have had .
on the other hand , the younger - old and the adults with more education may have been less influenced by such an expectancy , and therefore they were better able to appraise their own objective memory functioning [ 1 , 4 ] .
importantly , performance on measures of verbal fluency and processing speed did not affect the odds of smcs .
while most of our research volunteers may have had sufficient self - awareness to encode instances of deficits in these cognitive domains , and while they may have had introspective access to that information , they may not have linked these deficits to problems with memory , specifically .
also , verbal fluency and processing speed did not interact in any way with age , education , or gender in each of the models we studied .
third , the effect of objective memory ability on memory complaints seems to vary depending on whether subjects report on their own subjective experience when considering their memory functioning , versus when they consider how others evaluate their memory .
specifically , we only observed significant interactions between sociodemographic and cognitive variables when subjects reported on their own perceptions but not when they reported on perceptions of others ' evaluations .
we used a novel technique for identifying and contacting a sample of elders in our catchment area , designed to reduce biases commonly found in clinic- and population - based studies .
however , while comparisons between our study sample and 2000 census data from cuyahoga county showed that the groups were similar in terms of age and gender distribution , our study sample was comprised of more self - identified caucasians than african americans or other minorities and more persons with higher educational attainment levels . also , our response rate was relatively low ( about 33% ) . this response rate is lower than that reported in many random - digit - dialed phone surveys , which typically obtain rates ranging from 60 to 64% .
those with unlisted numbers are known to be younger and of lower socioeconomic status ( ses ) than those with listed numbers .
the ses bias presumably occurs because persons with low ses are more mobile and thus more likely to be unlisted
. however , mobility would presumably be low among our sample members due to their age , and thus there might not be an ses bias .
each of these limitations , individually , or together , may have biased results towards an underestimate of the prevalence of smcs .
other studies have used psychometrically validated scales to measure smcs , whereas we relied on simple likert - type ratings . however , even with this rudimentary measure , we were able to show associations with objective memory abilities .
the associations held even when controlling for important clinical variables such as family history and/or physician diagnosis of memory problems .
the fact that results were dependent on whether subjects took the vantage point of self versus other is particularly interesting .
apparently , subjects are able to keep the sources of concerns about their memory seperate ( their own versus others ) .
our study did not include a measure of depression . our reasoning centered on the fact that interviews were relatively long , lasting from 30 to 40 minutes .
we did not want to create too much subjective burden on subjects , risking our researcher / subject rapport , possibly resulting in a loss of the vital neuropsychological data . yet , from a clinical perspective , we have noted that pcps have improved in their recognition of depressive symptoms in routine office visits but many are not aggressive in characterizing memory loss as a possible outcome of depression . we believe that when a person has an smc that causes them distress , they should start to address the problem by visiting their pcp and describing their concerns .
if the cause of the complaint ( including depression ) is not found or treated , then consulting a specialist ( usually a general neurologist ) is a reasonable next step . at the typical pcp visit ,
probing for depression ( if it is not reported by the patient ) would seem reasonable as depression is correlated with many health problems and assessing its presence does not consume much office time . further , while studies have indicated that depression or depressive symptoms are correlated with smcs , with zero - order correlations ranging from .30 to .36 , the effect of adding depression to the equation depends not only on its correlation with smcs but also very much on how strongly it is correlated with our measures of memory ( hvlt ) or global cognitive functioning ( tics - m ) . since studies tend to support the idea that both memory and global cognitive functioning are not correlated very strongly with depression among the aged , including depression as a variable in our statistical models is not likely to alter the effect of memory or cognitive ability .
subjective memory complaints occur with frequency in the population . because they were a source of concern for participants and
are likely to be of concern to many older healthy adults in the general population , it becomes vital to understand their origins and importance .
future studies should continue to examine the basis of these complaints as well as the modifying effects of contextual variables such as sociodemographic factors , in an effort to more easily determine which complaints reflect a real problem and which represent needless worry on the part of a patient . | ### Summary:
: objectives . to estimate the prevalence of subjective memory complaints ( smcs ) in a sample of community - dwelling , older adults and to examine cognitive bases of these complaints . participants .
499 community - dwelling adults , 65 and older . measurements . a telephone survey consisting of cognitive tests and clinical and sociodemographic variables .
smcs were based on subjects ' evaluations and subjects ' perceptions of others ' evaluations . analysis .
logistic regression was used to model the risk for smcs as a function of the cognitive , clinical , and sociodemographic variables .
we tested for interactions of the cognitive variables with age , education , and gender .
results .
27.1% reported memory complaints . among the younger age ,
better objective memory performance predicted lower risk for smcs , while among the older age , better memory had no effect on risk . among the better - educated people ,
better global cognitive functioning predicted lower risk for smcs , while among the less - educated people , better global cognitive functioning had no effect on smc risk . when predicting others ' perceptions , better objective memory was associated with lower risk for smcs .
conclusion .
objective memory performance and global cognitive functioning are associated with lower risk for smcs , but these relationships are the strongest for the younger age and those with more education , respectively
. age and education may affect the ability to accurately appraise cognitive functioning . |
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: the pathogen was isolated from disease lesions of sweet persimmon fruit using a surface sterilization method .
mycelium for dna extraction was grown in 5 ml of potato dextrose broth in a rotary shaker at 160 rpm for 48 hr at 28. total genomic dna of the pathogen was extracted using the ctab extraction method .
the amplification was performed in a 20 l reaction mixture containing 10 pmol of each primer , two units of taq dna polymerase ( takara , tokyo , japan ) , 1 l of each dntp , 2 l of 10 pcr reaction buffer , and 50 ng of template dna .
pcr conditions were as follows : predenaturation at 94 5 min ; 30 cycles of denaturing at 94 for 30 sec ; annealing at 55 for 45 sec and extension at 72 for 40 sec ; and final extension at 72 for 10 min .
phylogenetic analysis of alternaria alternata was performed using the mega5 program with the neighbor - joining method . for pathogenicity testing ,
a. alternata was incubated for one week on pda at 28. a spore suspension adjusted to 1 10 spores / ml , then 10 l , was inoculated on the surface of sweet persimmon fruit using a needle .
control fruits were treated with sterilized water and the inoculated sweet persimmon fruits were kept in 90% relative humidity at 28 for two wk .
we observed symptoms of black spot on sweet persimmon fruit from the orchard located in jinju city , gyeongnam province , korea in 2012 .
the symptoms were similar to those of sweet persimmon anthracnose disease and the spot sizes ranged from 0.5~4 cm .
the potential causal agent of disease was isolated and purified . when the isolated fungi were inoculated artificially ,
small , black spots were observed on the inoculated fruit at four days after treatment . after two wk , these spots developed into large lesions ( fig .
1b ) , providing convincing evidence of infection through wound in the postharvest as well as the pre - harvest .
the disease symptoms were similar to those of disease lesions observed on pre - harvested persimmon fruit in orchards .
the fungal pathogen was re - isolated from disease lesions of inoculated fruit and the re - isolated pathogen exhibited the same morphological characteristics compared with the original isolates .
the optimum temperature for mycelial growth was 25 on pda ( data not shown ) .
conidia were brown , obpyriform to ellipsoid ( 22~39 8~15 m ) , with both transverse and longitudinal septa ( fig .
the pathogen of sweet persimmon black spot was identified as alternaria alternata based on morphological characteristics ( table 1 ) .
the sequences determined from the rrna - its were 100% similar to those of several a. alternata species of accession nos .
jf835809.1 , jn005702.1 , fj717733.1 , fj717733.1 , and jn673372.1 ; as a result , the causal fungus was identified as a. alternata ( fig . | ### Summary:
: black spot of sweet persimmon , caused by alternaria alternata , occurred in an orchard in gyeongnam province , korea in 2012 .
the symptom was appearance of 0.5 to 4 cm black spots on the surface of fruit .
the pathogen was isolated from flesh of disease lesions .
the causal agent was identified as a. alternata by morphological characteristics and sequencers of the internal transcribed spacer ( its ) 1 and its4 regions of rrna .
artificial inoculation of the pathogen resulted in development of disease symptoms and the re - isolated pathogen showed characteristics of a. alternata . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: normal ageing can be defined as a normal biologic process of the elderly characterized by relative cerebral atrophy without severe compromise of normal cognitive and motor functions .
the ageing brain shows volumetric decrease , usually associated with diffuse or focal white matter signal abnormalities .
a clear clinical or pathologic cutoff between physiologic and abnormal ageing of the brain does not exist , however .
recent developments in mri hardware and acquisition techniques hold great promise to more sensitively study brain changes in againg .
structural imaging , historically used to exclude an intracerebral lesion as a cause for dementia , is increasingly playing a role in ruling in diagnoses .
the recent availability of new treatments for dementia , as well as the importance of subtype - specific management , has renewed interest in the use of brain imaging techniques that can assist in the accurate recognition of alzheimer 's disease ( ad ) , vascular dementia ( vd ) , mixed dementia ( md ) , and normal pressure hydrocephalus ( nph ) .
mri has been the primary tool to link hippocampal volume loss with ad firmly . there is also growing interest regarding using mri in conjunction with biochemical marker of ad ( tau protein and amyloid ab ) and identifying early dementia mci ( mild cognitive impairment ) .
various studies have quantified the amount of hippocampal atrophy in old age and dementia but there is a lack of uniformity regarding the result .
there is a paucity of studies in our country regarding the hippocampal volume loss in cognitively normal elderly individuals and dementia . in present study effort has been made to quantify the amount of hippocampal volume loss in old age and dementia and study the effect of dementia on brain atrophy .
this opens the possibility to study the ageing brain in an epidemiological context and to define new imaging biomarkers for neurodegenerative and cerebrovascular disease at the population level .
the present study was carried out in the department of radiodiagnosis and imaging , sir sunderlal hospital , institute of medical sciences , banaras hindu university , varanasi , during the period from july 2010 to july 2012 .
patients presenting to the department of neurology with history of memory loss formed part of study . a detailed history regarding age , sex , duration of symptoms , and comorbid conditions was taken . a complete blood count , thyroid function test , serum vitamin b12 and folate estimation , and a syphilis test were performed in order to exclude other causes of dementia .
patients with abnormal laboratory results , intracranial mass lesions , history of brain trauma or other neurological disorders , acute stroke within the past 6 months , or who were dependent on alcohol or psychoactive substances were excluded from the study .
healthy age - matched volunteers with no neurological , psychiatric , or systemic disease were recruited to the control group .
all study participants were evaluated according to the diagnostic and statistical manual of mental disorders ( dsm - iv ) .
alzheimer 's disease was diagnosed according to the methods described by the national institute of neurological and communicative disorders and stroke and the alzheimer 's disease and related disorders association ( nincds - adrda ) .
the national institute of neurological and communicative disorders and stroke and association internationale pour la recherche et l'enseignement en neurosciences ( ninds - airen ) criteria were used for diagnosis of vascular dementia . a scoring system developed by kubo et al
. for diagnosis of idiopathic normal pressure hydrocephalus ( inphs ) was used as diagnostic criteria for diagnosis of normal pressure hydrocephalus .
cognitive function was evaluated in all participants using the mini mental state examination ( mmse ) . since majority of our subjects
did not belong to highly educated group a score of 24 was taken as normal .
subjects were stratified according to mmse score : severe dementia ( < 9 ) ; moderate dementia ( 1017 ) ; mild dementia ( 1724 ) .
scanning was performed in the supine position with a 1.5 t imaging systemmagnetom avanto ( version bv - i7a ) siemens medical system , erlanger , germany .
the imaging protocol comprised a coronal t1-weighted flash ( fast low angle shot ) 3d sequence with slice thickness 1.5 mm , repetition time 14 ms , echo time 4.76 ms , flip angle 25 , and matrix 160 256 .
the boundaries of the hippocampus were outlined manually on each slice according to the previously described criteria by a radiologist who was blind to the diagnosis .
on coronal viewing , the most anterior slice is the slice on which the hippocampus is first visible .
this is seen as a notch in the medial border of the temporal horn of the lateral ventricle ; this notch is the border between the amygdala and the hippocampus .
the structure of the hippocampus is usually visible , with the white matter of the alveus as a border between the hippocampus and the amygdala .
the uncal apex of the hippocampus is then visible ; sometimes the hippocampus appears to be in two parts if so , both parts were included .
most of the times , a thin white line is visible on top of the hippocampus : this line corresponds to the alveus and fimbria , which function as a border between the hippocampus and the csf / choroid plexus . when there is no atrophy or only minor atrophy , the hippocampus will border the temporal stem and midbrain .
the tail of the caudate nucleus , the optical tract , and the lateral geniculate nucleus as well as the more posterior part of the pulvinar are grey matter structures that were not included . when there is atrophy , the hippocampus is mostly surrounded by csf . in the most posterior slices
a straight horizontal line is drawn through the fimbria / fornix at the dorsal border ( the more grey appearing part ) of the hippocampus .
the last , most posterior , slice to measure is the first slice on which the total length of the crus of the fornix is seen . using manual tracing hippocampus
the sum of tracing on each side gave the total hippocampal area . to get the hippocampal volume ( in cm ) the area was multiplied by 0.3 ( as slice thickness is 1.5 mm and distance between slices is 1.5 mm ) .
anova with post hoc analysis was used to compare the means over the study groups .
alzheimer 's disease formed one group , vascular dementia formed another , and controls formed the last group .
statistical correlation was carried between the groups for the following variable right hippocampal volume , left hippocampal volume , total hippocampal volume , and hippocampal ratio .
the study population comprised 41 patients 11 with alzheimer 's disease , 10 with vascular dementia , 3 mixed dementia , 2 normal pressure hydrocephalus , and 15 control subjects .
there were no significant between - group differences in age , education , or dominant hand .
mean mmse scores were significantly lower in patients with vascular dementia compared with all other groups ( p < 0.001 ) . demographic data , duration of symptoms and mmse score are shown in table 1 .
statistically significant difference was found ( p value 0.002 ) when the ad group was compared with controls and 25% volume reduction in ad was noted ( table 2 ) . when hippocampal volume of vascular dementia group was compared with controls no significant statistical difference
mixed dementia and nph showed an average hippocampal volume reduction of 21% and 5% compared to controls though not statistically significant .
similarly statistical significance was found ( p value < 0.001 ) for right versus left hippocampal volume and hippocampal ratio , when ad cases were compared with controls .
also no statistically significant reduction in hippocampal volume was demonstrated between ad and vascular dementia ( p value being 0.348 ) .
hippocampal volume was reduced by 5% in subjects with mild dementia ( n = 12 ) , 12% in those with moderate dementia ( n = 10 ) , and 34% in those with severe dementia ( n = 4 ) compared with subjects with normal cognitive function ( n = 15 ) .
this study examined the relationship between hippocampal volume and cognitive impairment in patients with alzheimer 's disease , vascular dementia , mixed dementia , normal pressure hydrocephalus , and control subjects , using an mri - based volumetric method .
mean age of ad group was 71.18 years , mean age of vascular dementia group was 62.20 years , and that in controls was 66.27 years . in a related study by schmidt mean age of patients probable
alzheimer 's disease was 68.2 years , as against mean age of 69.9 years for vascular dementia , and 66.3 years for normal controls .
we found that 42.30% cases were in ad group , 11.53% were in mixed dementia group , 38.4% were in vascular dementia group , and 7.60% were in nph group . according to knopman et al .
pathological diagnoses were ad 51% , pure vd in 13% , mixed dementia in 12% , and other diagnoses in the remaining patients . in another study by schmidt ,
53.4% were probable ad , and 46.6% were patients of vascular dementia . in a study by nair et al . among those with dementia ,
45.7% had ad ( probable or possible ) , 22% had vd ( probable or possible ) , 15% had mixed dementia , and the rest had dementia due to other causes .
average mmse / hmse score of ad cases in our study was 18.18 , average mmse / hmse score of vascular dementia was 12.4 , average mmse / hmse score of mixed dementia was 13 , and average score of nph cases was 22.50 . in a study by nair et al .
average mmse / hmse score in ad cases was 17.12 and vascular dementia cases was 16.30 .
average mmse / hmse scores of the present study correlate well with mmse / hmse scores of other studies in our subcontinent .
average mmse / hmse score of present study in demented group was 19.29 , in a study by frisoni et al . ;
our study showed an average of total hippocampal volume of cases in ad group was 3.916 ( 0.3 ) cm , in vascular dementia group was 4.660 ( 0.22 ) cm , and in controls was 5.202 ( 0.76 ) cm ( table 2 ) .
statistically significant difference was found ( p value 0.002 ) when ad group was compared with controls and 25% volume reduction in ad was noted . in a study by frisoni et al . a 32.5% volume reduction in total hippocampal volume was noted ( average age 76 6 years , average mmse 13 4 ) in ad as compared to control subjects .
giedd et al . studied the hippocampal volume ( normalized relative to the size of the lenticular nucleus ) and has concluded hippocampal volume to be reduced by 40% in the ad group compared to the controls . in a study by du et al .
total hippocampal volume of patients with nc ( normal cognition ) was 6327 mm and 4595 mm in those with ad , with 27% volume reduction in ad cases .
slightly higher volumes noted in this study could be due to a difference in ethnicity of cases and controls and difference in boundaries of hippocampus ( boundaries of the hippocampus were drawn including the hippocampus proper , dentate gyrus , subiculum , fimbria , and alveus . ) .
when hippocampal volume of vascular dementia group was compared with controls no significant statistical difference was found ( p value being 0.124 ) though average hippocampal volume of vascular dementia cases was 11% less than average hippocampal volume of control group . in a study by du et al .
when comparison of hippocampal volume between cognitively normal aged controls and patients of sivd ( subcortical vascular dementia ) was done , 18.2% smaller hippocampal volume was demonstrated in vascular dementia with statistically significant p value .
also no statistically significant reduction in hippocampal volume was demonstrated between ad and vascular dementia ( p value being 0.348 ) . but ad patients showed a 17.5% reduction in hippocampus volume compared to vd patients .
have also failed to demonstrate statistically significant difference in hippocampal volume between vascular dementia and ad .
studied changes in hippocampal volume in patients of vascular dementia and ad and concluded that hippocampal volume was about 5% smaller in the alzheimer 's disease group compared to the vd group , and the difference was not significant .
this would mean that a percentage of reduction of hippocampal volume can be used as a correlative parameter but not as an objective one while trying to subclassify dementia based on hippocampal volume .
similarly statistical significance was found ( p value < 0.001 ) for right , left hippocampal volume ( table 2 ) , and hippocampal ratio when ad cases were compared with controls .
average hippocampal volume in ad in our study was 1.921 cm , average volume of hippocampus in control was 2.60 cm and vascular dementia 2.299 cm . in a study by schuff et al .
hippocampal volume in control averaged 2133 ( 25 ) mm , patients with mild cognitive impairment averaged 1846 ( 23 ) mm , and clinical ad averaged 1631 ( 34 ) mm .
average left hippocampal volume in ad , in our study was 1.846 ( 0.21 ) cm and right hippocampal volume in ad cases was 1.997 ( 0.25 ) cm .
average left hippocampal volume in vascular dementia was 2.370 cm ( 0.35 ) cm and right hippocampal volume in vascular dementia cases was 2.29 ( 0.33 ) cm .
many studies have repeatedly demonstrated asymmetric volume reduction in ad with left hippocampus being smaller than right in ad . according to carne et al .
this however reflects the physiological hemispheric asymmetry of the human hippocampus which has been consistently demonstrated in a large number of studies involving healthy subjects of all ages but mller et al .
noted left hippocampus may be more vulnerable in ad than right hippocampus due to smaller volume in the left . in a longitudinal study over a three - year period fox et al .
found significantly smaller initial left hippocampi in those subjects who became demented during the observation period and concluded that hippocampal asymmetry may be an early sign of the presence of a degenerative process .
also found smaller left hippocampal volumes in ad compared to parkinson 's disease and vascular dementia . in relation to higher discriminative power of the left hippocampus , krasuski et al . reported that left - hemispheric volumetric measures of medial temporal lobe structures provided a higher accuracy of group discrimination in a sample of mildly demented ad patients versus controls .
there were differences in hippocampal volume between patients with moderate or severe dementia and subjects with normal cognitive function in the present study .
analysis of the pooled study population revealed a relationship between the degree of cognitive impairment and hippocampal atrophy , such that subjects with greater cognitive impairment ( low mmse score ) had smaller hippocampal volumes .
there are likely to be differences between the early and late stages of dementia in the same patient and hippocampal atrophy in the late stage of one dementia subtype may be indistinguishable from that in the early stage of another dementia subtype
. the diagnosis of dementia subtype may be difficult with a single measurement , and repeated volumetric analyses may have higher discriminatory value .
the small size of the study cohort meant that it was not possible to analyze the relationship between severity of dementia and hippocampal volume for each dementia subtype .
excellent anatomical delineation of hippocampus and cortical structure have made hippocampal volumetry and linear measurement accurate .
serial measurement of hippocampal volume may help in predicting the progression of disease and initiating early treatment .
though mr imaging provides excellent opportunity to depict the anatomical changes in brain ageing process , recent advances in neuroimaging like dwi , mr spectroscopy , dti , and fmri need to be conjured to depict the biological changes in brain ageing . | ### Summary:
: aims . to examine the relationship between different types of dementia and hippocampal volume
. methods .
hippocampal volume was measured using fl3d sequence magnetic resonance imaging in 26 alzheimer 's , vascular dementia , mixed dementia , and normal pressure hydrocephalus patients and 15 healthy controls and also hippocampal ratio , analyzed .
minimental scale was used to stratify patients on cognitive function impairments .
results .
hippocampal volume and ratio was reduced by 25% in alzheimer 's disease , 21% in mixed dementia , 11% in vascular dementia and 5% in normal pressure hydrocephalus in comparison to control .
also an asymmetrical decrease in volume of left hippocampus was noted .
the severity of dementia increased in accordance to decreasing hippocampal volume .
conclusion .
measurement in hippocampal volume may facilitate in differentiating different types of dementia and in disease progression .
there was a correlation between hippocampal volume and severity of cognitive impairment . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: alginate , the monovalent form of alginic acid , belong to the family of linear copolymers composed of -d- mannuronic acid monomers ( m ) , regions of -l- guluronic acid residues ( g ) , and regions of interspersed m and g units ( 1 ) .
it is used as matrix material in various formulations due to its hydrogel - forming properties ( 2 ) .
alginates undergo gelation due to ionic interaction between carboxylic acid groups located on polymer backbone and these cations like ca , al , etc ( 3 , 4 ) .
various drugs have been successfully incorporated in alginate hydrogels and have exhibited different drug release profiles ( 1 , 46 ) .
diclofenac sodium ( ds ) is a non - steroidal anti - inflammatory agent widely used as analgesic ( 7 ) .
its biological half - life is 12 hr ( 2 ) and requires multiple dosing to maintain therapeutic concentration in blood .
hence , the controlled release systems of ds can eliminate the need for multiple dosing and adverse effects .
several investigations on formulation of ds - loaded alginate - based microparticles / beads using different polymer - blend have been reported ( 710 ) .
however , no attempt has been taken to formulate ds - loaded bead system using alginate - polyvinyl pyrrolidone ( pvp ) blend . therefore in the present investigation
, an attempt was made to develope and optimize ds - loaded alginate - pvp k 30 microbeads .
the effects of ratios of sodium alginate to pvp k 30 and cacl2 ( cross - linker ) concentrations on drug entrapment and release were analyzed using central composite design ( ccd ) .
ds ( techno remedies , india ) , calcium chloride , sodium alginate and pvp k 30 ( loba chemie , india ) were used in this study .
ds - loaded alginate - pvp k 30 microbeads were prepared by ionotropic gelation ( 2 ) .
then , ds was added to the mixture and homogenized ( for 10 min , 1000 rpm ) .
the resulting mixture ( drug : polymer=1:2 ) was dropped into cacl2 solution via 26-gauge needle .
after 15 min , beads were collected by decantation , washed repeatedly with deionized water and dried at 45c for 12 hrs .
ds - loaded alginate microbeads were prepared by the same method but without addition of pvp k 30 .
the experimental factors were selected as polymer - blend ratio and cacl2 concentration ; while responses were drug entrapment efficiency ( dee ) and drug release after 10 hrs ( r10hr ) .
the quadratic model was used to evaluate responses using design - expert software according to ccd ( 11):1y = b0+b1x1+b2x2+b3x1x2+b4x12+b5x22
factors and levels of the circumscribed central composite design a sa : pvp k 30=sodium alginate to polyvinyl pyrrolidone k 30 ratio where , y = response ; b0=intercept , and b1-b5=regression coefficients . x1 and x2=individual effects ; x1 and x2=quadratic effects ; x1x2=interaction effect .
drug - loaded microbeads ( 100 mg ) were dispersed in 500 ml of phosphate buffer of ph 7.4 and sonicated for 10 min .
the mixture was stirred at 1000 rpm for 4 hrs and filtered through whatman filter paper .
drug contents in filtrates were determined using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
the dee of beads was calculated using following formula:2dee(%)=actual drug contenttheoretical drug content100
microbeads were measured for particle size using optical microscope ( olympus , japan ) .
surface morphology was examined by scanning electron microscopy ( sem ) ( hitachi , japan ) .
spectra were obtained by ftir spectrophotometer ( perkin - elmer , usa ) in the wavelength region of 4000 - 400 cm using pellets of kbr .
dissolution apparatus usp ( campbell electronics , india ) was employed to study the drug release at 37c 50 rpm .
microbeads containing ds equivalent to 100 mg were taken in 900 ml of dissolution medium ( 0.1 n hcl of ph 1.2 for 2 hrs and phosphate buffer of ph 7.4 for next hrs ) .
drug content in samples were measured using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
microbeads ( 100 mg ) were soaked in phosphate buffer of ph 7.4 and 0.1 n hcl of ph 1.2 .
swelling indexes were determined using the formula:3swelling index = weight of swelled microbeads dry weightdry weight100
ds ( techno remedies , india ) , calcium chloride , sodium alginate and pvp k 30 ( loba chemie , india ) were used in this study .
ds - loaded alginate - pvp k 30 microbeads were prepared by ionotropic gelation ( 2 ) .
then , ds was added to the mixture and homogenized ( for 10 min , 1000 rpm ) .
the resulting mixture ( drug : polymer=1:2 ) was dropped into cacl2 solution via 26-gauge needle .
after 15 min , beads were collected by decantation , washed repeatedly with deionized water and dried at 45c for 12 hrs .
ds - loaded alginate microbeads were prepared by the same method but without addition of pvp k 30 .
the experimental factors were selected as polymer - blend ratio and cacl2 concentration ; while responses were drug entrapment efficiency ( dee ) and drug release after 10 hrs ( r10hr ) .
the quadratic model was used to evaluate responses using design - expert software according to ccd ( 11):1y = b0+b1x1+b2x2+b3x1x2+b4x12+b5x22
factors and levels of the circumscribed central composite design a sa : pvp k 30=sodium alginate to polyvinyl pyrrolidone k 30 ratio where , y = response ; b0=intercept , and b1-b5=regression coefficients . x1 and x2=individual effects ; x1 and x2=quadratic effects ; x1x2=interaction effect .
drug - loaded microbeads ( 100 mg ) were dispersed in 500 ml of phosphate buffer of ph 7.4 and sonicated for 10 min .
the mixture was stirred at 1000 rpm for 4 hrs and filtered through whatman filter paper .
drug contents in filtrates were determined using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
the dee of beads was calculated using following formula:2dee(%)=actual drug contenttheoretical drug content100
microbeads were measured for particle size using optical microscope ( olympus , japan ) .
surface morphology was examined by scanning electron microscopy ( sem ) ( hitachi , japan ) .
spectra were obtained by ftir spectrophotometer ( perkin - elmer , usa ) in the wavelength region of 4000 - 400 cm using pellets of kbr .
dissolution apparatus usp ( campbell electronics , india ) was employed to study the drug release at 37c 50 rpm .
microbeads containing ds equivalent to 100 mg were taken in 900 ml of dissolution medium ( 0.1 n hcl of ph 1.2 for 2 hrs and phosphate buffer of ph 7.4 for next hrs ) .
drug content in samples were measured using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
microbeads ( 100 mg ) were soaked in phosphate buffer of ph 7.4 and 0.1 n hcl of ph 1.2 .
swelling indexes were determined using the formula:3swelling index = weight of swelled microbeads dry weightdry weight100
ds - loaded alginate - pvp k 30 microbeads were prepared by ionotropic gelation ( 2 ) .
then , ds was added to the mixture and homogenized ( for 10 min , 1000 rpm ) .
the resulting mixture ( drug : polymer=1:2 ) was dropped into cacl2 solution via 26-gauge needle .
after 15 min , beads were collected by decantation , washed repeatedly with deionized water and dried at 45c for 12 hrs .
ds - loaded alginate microbeads were prepared by the same method but without addition of pvp k 30 .
the experimental factors were selected as polymer - blend ratio and cacl2 concentration ; while responses were drug entrapment efficiency ( dee ) and drug release after 10 hrs ( r10hr ) .
the quadratic model was used to evaluate responses using design - expert software according to ccd ( 11):1y = b0+b1x1+b2x2+b3x1x2+b4x12+b5x22
factors and levels of the circumscribed central composite design a sa : pvp k 30=sodium alginate to polyvinyl pyrrolidone k 30 ratio where , y = response ; b0=intercept , and b1-b5=regression coefficients . x1 and x2=individual effects ; x1 and x2=quadratic effects ; x1x2=interaction effect .
drug - loaded microbeads ( 100 mg ) were dispersed in 500 ml of phosphate buffer of ph 7.4 and sonicated for 10 min .
the mixture was stirred at 1000 rpm for 4 hrs and filtered through whatman filter paper .
drug contents in filtrates were determined using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
surface morphology was examined by scanning electron microscopy ( sem ) ( hitachi , japan ) .
spectra were obtained by ftir spectrophotometer ( perkin - elmer , usa ) in the wavelength region of 4000 - 400 cm using pellets of kbr .
dissolution apparatus usp ( campbell electronics , india ) was employed to study the drug release at 37c 50 rpm .
microbeads containing ds equivalent to 100 mg were taken in 900 ml of dissolution medium ( 0.1 n hcl of ph 1.2 for 2 hrs and phosphate buffer of ph 7.4 for next hrs ) .
drug content in samples were measured using uv - vis spectrophotometer ( shimadzu , japan ) at 276 nm wavelength .
microbeads ( 100 mg ) were soaked in phosphate buffer of ph 7.4 and 0.1 n hcl of ph 1.2 .
swelling indexes were determined using the formula:3swelling index = weight of swelled microbeads dry weightdry weight100
ds - loaded alginate - pvp k 30 microbeads were prepared by ionotropic gelation according to ccd ( table 2 ) .
quadratic models were selected as better - fit models due to smaller press , and insignificant lack of fit ( table 3 ) .
results of anova indicated all models were significant ( table 4 ) . after eliminating non - significant ( p>0.05 ) terms , the models became:4dee=58.67 - 0.66x1 + 8.12x2 - 1.28x12 - 0.41x22
5r10h=99.43 - 1.13x1 - 3.54x2 - 0.40x1x2 - 0.06x2
experimental plan and observed response values from randomized run in central composite design
. observed response values : meansd ( n=3 ) ; sa : pvp k30=sodium alginate to polyvinyl pyrrolidone k 30 ratio ; dee = drug entrapment efficiency ( % ) ; r10hr=% drug released in 10 hrs summary of the model analysis ( a ) , lack of fit ( b ) , and r2 analysis ( c ) for the measured responses .
dee = drug entrapment efficiency(% ) ; r10hr = % drug released in 10 hrs ; 2fi = two factor interaction ; press = predicted residual sum of squares .
summary of anova for the response parameters dee = drug entrapment efficiency ( % ) ; r10hr=% drug released in 10 hrs . x1 and x2 represent the factors ; x1
and x2
are the quadratic effect ; x1x2 is the interaction effect .
2 ) demonstrate changes in dee , and r10hr due to variation of factors . for optimization ,
numerical analysis was performed by restricting desirable ranges to 95 dee 100% , and 60 r10hr 65% .
models to produce optimized responses were well fitted ( r=0.9912 for dee , and 0.9967 for r10hr ) .
effect of main effects on responses presented by contour plots ( a , and b ) .
sa : pvp k 30=sodium alginate to polyvinyl pyrrolidone k 30 ratio ; dee = drug entrapment efficiency ( % ) ; r10hr=% drug released within 10 hrs ; observed response values : meansd ( n=3 ) .
optimized microbeads showed dee of 97.882.86 to 98.603.55% . among ds - loaded alginate microbeads , highest dee of 85.772.92%
processing parameters and responses of plain alginate microbeads containing diclofenac sodium . observed response values : meansd ( n=3 ) ; dee = drug entrapment efficiency ( % ) ; r10hr = % drug released in 10 hrs the particle sizes of alginate - pvp k 30 microbeads decreased by increase in the amount of incorporated pvp k 30 ( due to decrease in viscosity and droplet sizes of polymer solution ) , and the cacl2 concentration ( due to high degree cross - linking ) ( table 7 ) .
the surface morphology of optimized beads was visualized by sem , which showed rough surface ( fig .
photomicrograph of the surface morphology of ds - loaded alginate - pvp k 30 microbead ( o-2 ) .
average diameter of alginate - pvp k 30 and plain alginate microbeads containing diclofenac sodium , measured by optical microscopic method .
sp-1 to o-3 were alginate - pvp k 30 microbeads ; whereas s-1-s-3 were plain alginate microbeads containing diclofenac sodium . in ftir spectra ,
incorporation of ds in alginate showed characteristic peaks of ds , and alginate ( fig .
however , in ds - loaded alginate - pvp k 30 microbeads , two characteristic shifts for c = o stretching of pvp , and oh groups of alginate compared to pure component ( fig .
4 ) appeared which strongly supports the idea of an intermolecular hydrogen - bonding between c = o groups of pvp , and oh groups of alginate in alginate - pvp k 30 microbeads .
ftir spectra of ds , sodium alginate , pvp k 30 , ds - loaded alginate ( s-3 ) and ds - loaded alginate - pvp k 30 microbeads ( o-2 ) .
microbeads were found to release negligible amounts of ds in acidic medium which probably could be the surface adhered drug .
alginate - pvp k 30 microbeads showed prolonged drug release over 10 hrs ( figs . 5 and 6 ) . in contrast , alginate microbeads showed high percent of ds release ( fig .
the drug release from optimized microbeads was evaluated using various kinetic models , and it was found that the drug release followed zero - order model ( table 8) , indicating controlled - release pattern .
the korsmeyer - peppas model was employed to distinguish fickian - release when n 0.43 and case - ii transport when n 0.85 ( in korsmeyer - peppas model , n is diffusional exponent ) ( 12 , 13 ) .
the values of n ranged between 0.9632 to 0.9950 ( table 8) , indicating the drug release followed case - ii transport .
( a ) . in vitro drug release from alginate - pvp k 30 microbeads containing ds ( sp-1 to sp-6 ) ( meansd , n=3 ) .
( b ) . in vitro drug release from alginate - pvp k30 microbeads containing ds ( sp-7 to sp-13 ) ( meansd , n=3 ) in vitro drug release from optimized alginate - pvp k 30 microbeads ( o-1 to o-3 ) and alginate microbeads ( s-1 to s-3 ) containing ds ( meansd , n=3 ) .
results of curve fitting of the in - vitro diclofenac sodium release data from different optimized alginate - pvp k30 microbeads .
the swelling of optimized ds - loaded alginate - pvp k 30 microbeads was lower in acidic medium ( ph 1.2 ) in comparison with that of alkaline medium ( ph 7.4 ) ( fig .
maximum swelling was noticed after 23 hrs in alkaline ph after which , erosion and dissolution took place .
the swelling of optimized microbeads in alkaline ph could be explained by the exchange of ions between the calcium ion of microbeads and the sodium ions present in phosphate buffer , under influence of calcium - sequestrant phosphate ions , which could result in disaggregation of alginate - pvp k 30-matrix structure leading to matrix erosion and dissolution of swollen microbeads ( 14 , 15 ) .
swelling behavior of the optimized alginate - pvp k 30 microbeads containing ds in ph 1.2 and ph 7.4 .
the optimized formulation of alginate - pvp k 30 microbeads containing ds was developed based on central composite design .
the dee of optimized alginate - pvp k 30 microbeads containing ds were found to be 97.882.86 to 98.603.55 % with a controlled - release pattern ( zero - order ) and case - ii transport drug release .
the swelling behaviour of the developed microbeads was influenced by the ph of the test medium .
the ftir spectroscopy showed an intermolecular hydrogen - bonding which could be formed between c = o groups of pvp k 30 and oh groups of alginate in alginate - pvp k 30 microbeads which might sustaine drug release from alginate - pvp k 30 microbeads and minimize drug leaching during preparation to facilitate increase in dee .
the methods of preparation of ds - loaded alginate - pvp k 30 for controlled release characteristics were found to be simple and reproducible . in conclusion ,
an oral alginate - pvp k 30 microbeads for controlled delivery system of ds was successfully developed by alginate - pvp k 30 blending using ionotropic gelation . | ### Summary:
: background and the purpose of the studydiclofenac sodium is a non - steroidal anti - inflammatory agent with a short biological half - life ( 12 hr ) and requires multiple dosing .
this research was carried out to develop and optimize diclofenac sodium loaded alginate - pvp k 30 microbeads to eliminate the need for multiple dosing and adverse effects.methodsdiclofenac sodium loaded alginate - pvp k 30 microbeads were prepared by ionotropic gelation .
particle size , drug release , swelling , ftir and sem analyses were performed.resultsoptimized microbeads showed particle size of 0.5890.054 to 0.6200.067 mm , and drug entrapment efficiency of 97.882.86 to 98.603.55% .
the in vitro drug release from microbeads was sustained over 10 hrs and followed controlled - release pattern .
ftir analysis indicated the possibility of intermolecular hydrogen bonding interactions , i.e. , oh o = c in microbeads.conclusionmicrobeads for oral controlled delivery of diclofenac sodium were successfully developed by ionotropic gelation . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: small incision cataract surgery is considered a refractive surgery , targeting early visual rehabilitation and emmetropia . with the development of new technologies in the manufacturing of intraocular lenses and the introduction of new generation algorithms in biometry ,
incision size ( width and length ) and configuration ( one- , two- , and three - step ) , incision location relative to the limbus , and the axis on which the main incision was performed15 are the parameters that a surgeon can impact in order to change ( or not change ) preoperative astigmatism .
factors such as the eye ( left or right),6,7 corneal pachymetry,8 the magnitude of preoperative astigmatism,9 and the type of astigmatism ( with the rule [ wtr ] , against the rule [ atr])10 are parameters that we take into account when planning cataract surgery , but that we can not interfere with in order to change corneal refractive status .
the purpose of this study is to introduce the distance between tunnel and sideport incision as a factor affecting postoperative astigmatism and to evaluate the forces that act to change the cornea .
a small incision temporally positioned is thought to be , by most surgeons , astigmatically neutral when compared with a superotemporal , superonasal , or superior incision.3,1113 we propose a certain distance between a tunnel and sideport incision so that our main incision , when it is performed from above the patients head , will minimally affect postoperative corneal astigmatism .
this observational study was performed at the general hospital of piraeus tzaneio , attiki , greece , from february 2011 to october 2013 .
the study was approved by the hospital s ethics committee and was performed in accordance with the ethical principles of the declaration of helsinki . written informed consent was obtained from each patient . in this research
preoperative exclusion criteria were previous anterior segment surgery , dry eye syndrome , chronic use of eye drops , and corneal pathology , such as epithelial or stromal lesions , scars , endothelial guttata , and a horizontal corneal diameter < 11.5 mm and > 12.5 mm .
moreover , all cases of unrecordable corneal topography , big differences between serial measurements , a dilated pupil diameter smaller than 5.5 mm , and cataract grading ( according to the lens opacities classification system [ locs ] iii ) of nc5no5 or nc6no6 served as factors delaying cataract surgery , further stressing the main incisions that were excluded .
postoperative exclusion criteria were suturing of the incisions , complicated surgery necessitating enlargement of the tunnel incision , bad incisions leading to ballooning , wound burn , unstable anterior chamber or tight fit around the phaco probe , iris prolapse ( posteriorly placed incision ) , corneal distortion due to an anteriorly placed incision , and a superficial incision .
preoperatively , all patients underwent visual acuity and biomicroscopic examination , intraocular pressure measurement with goldmann applanation tonometry , and fundoscopy with a dilated pupil .
preoperatively , on the slit lamp , axes at 90 , 180 , and 0 were marked as reference axes with a surgical marker in the seated position by turning the light beam coaxially in order to avoid cyclotorsion in the supine position.1416 the location of the tunnel incision was marked at 100130. sideport incision location was preoperatively marked on the slit lamp , depending on the assigned group . in cases
where the distance between the tunnel and sideport incision was < 90 , the tunnel incision was located at 100130 and the sideport incision was located at 3050. in cases where the distance is > 110 , the sideport incision was located at 35010. we chose to refer to the incisions as degrees of arc because our incisions were of a certain width . in a mean 12.0 mm diameter cornea , the width of a 3.0 mm tunnel incision corresponds to 28.6630 and a 1.0 mm sideport incision corresponds to 9.5510 , respectively .
postoperative follow up was scheduled on the 1st day , 1st month , and 6th month after surgery .
biomicroscopy at the slit lamp , where the axis of the tunnel and sideport incisions were reported by turning the light beam coaxially to the tunnel and sideport incisions , was performed .
also , the best corrected visual acuity using snellen optotype and corneal topography were performed .
surgically induced astigmatism ( sia ) was calculated by vector analysis using alpin s method .
all cases that presented with a change over 0.5 d in corneal astigmatic power and over 20 in the astigmatic axis , independent of the direction of torque , were studied . of note , 025 and
technique using sovereign with whitestar ( abbott medical optics inc , santa ana , ca , usa ) .
tetracaine hydrochloride 0.5% drops were installed for topical anesthesia . a three - step clear corneal incision ( 3.0 mm )
was made in the superotemporal region for the right eye and superonasal region for the left eye ( at 100130 ) .
the anterior chamber was reformed with medium viscosity sodium hyaluronate 1.5% ( la lon ; la labs , los angeles , ca , usa ) for the protection of the corneal endothelium and iris .
a stab sideport incision ( 1.0 mm ) was made a predetermined distance away from the main incision ( < 90 , 90110 , or > 110 ) followed by hydrodissection and hydrodelineation .
complete nucleus removal was followed by aspiration of the cortex and injection of a foldable hydrophilic acrylic three - piece intraocular lens .
all eyes were under medication therapy with a combination of tobramycin dexamethasone and nepafenac ophthalmic drops four times per day for 1 month .
quantitative variables were expressed as the mean values ( sd ) and/or median value , while qualitative variables were expressed as absolute and relative frequencies . the kolmogorov
paired t - tests were used for comparisons of preoperative and postoperative measures between the left and right eyes . for the comparison of proportions ,
repeated measurements analysis of variance ( anova ) was adopted to evaluate the changes observed in sia according to distance between the tunnel and sideport incision over the follow - up period .
multiple logistic regression analyses were used to test the effects of the type of astigmatism and the distance between the tunnel and sideport incision on a change of over 0.5 d in astigmatic power or a change of over 20 in the astigmatic axis . in order to test whether the effect of distance between the tunnel and sideport incisions on a change over 0.5 d in astigmatic power or change over 20 in the astigmatic axis was different from or consistent with the different types of astigmatism , the interaction of the variables was tested in the logistic regression models .
odds ratios ( or ) with 95% confidence intervals ( ci ) were computed from the results of the logistic regression analyses .
statistical significance was set at p,0.05 and the analyses were conducted using spss statistical software ( version 19.0 ; ibm corporation , armonk , ny , usa ) .
all patients underwent phacoemulsification with the horizontal chopping technique using sovereign with whitestar ( abbott medical optics inc , santa ana , ca , usa ) .
a three - step clear corneal incision ( 3.0 mm ) was made in the superotemporal region for the right eye and superonasal region for the left eye ( at 100130 ) .
the anterior chamber was reformed with medium viscosity sodium hyaluronate 1.5% ( la lon ; la labs , los angeles , ca , usa ) for the protection of the corneal endothelium and iris .
a continuous curvilinear capsulorhexis was created with utrata forceps . a stab sideport incision ( 1.0 mm )
was made a predetermined distance away from the main incision ( < 90 , 90110 , or > 110 ) followed by hydrodissection and hydrodelineation .
complete nucleus removal was followed by aspiration of the cortex and injection of a foldable hydrophilic acrylic three - piece intraocular lens .
all eyes were under medication therapy with a combination of tobramycin dexamethasone and nepafenac ophthalmic drops four times per day for 1 month .
quantitative variables were expressed as the mean values ( sd ) and/or median value , while qualitative variables were expressed as absolute and relative frequencies . the kolmogorov
paired t - tests were used for comparisons of preoperative and postoperative measures between the left and right eyes . for the comparison of proportions ,
repeated measurements analysis of variance ( anova ) was adopted to evaluate the changes observed in sia according to distance between the tunnel and sideport incision over the follow - up period .
multiple logistic regression analyses were used to test the effects of the type of astigmatism and the distance between the tunnel and sideport incision on a change of over 0.5 d in astigmatic power or a change of over 20 in the astigmatic axis . in order to test whether the effect of distance between the tunnel and sideport incisions on a change over 0.5 d in astigmatic power or change over 20 in the astigmatic axis was different from or consistent with the different types of astigmatism , the interaction of the variables was tested in the logistic regression models .
odds ratios ( or ) with 95% confidence intervals ( ci ) were computed from the results of the logistic regression analyses .
statistical significance was set at p,0.05 and the analyses were conducted using spss statistical software ( version 19.0 ; ibm corporation , armonk , ny , usa ) .
of a total of 333 treated eyes , 25 were excluded because of surgical complications or bad incisions , and the rest of the 308 eyes were followed postoperatively ( 158 left and 150 right eyes ) . the mean age of the patients was 72.6 years ( sd = 9.1 years ) and 46.4% of these individuals were males .
the distribution of the left and right eyes , according to the distance between the tunnel and sideport incisions , is shown in table 1 .
table 2 presents the differences in preoperative and postoperative measures of corneal astigmatic power between the left and right eyes .
repeated measurements anova was adopted to evaluate the changes observed in sia according to the distance between the tunnel and sideport incisions over the follow - up period , separately , in the left and right eyes .
sia changes between the 1st and 6th postoperative month according to the distance between the tunnel and sideport incisions are shown in table 3 . in table 4 ,
the postoperative corneal astigmatic power measures at the 1st and 6th month according to the distance between the tunnel and sideport incisions are presented .
cases where changes over 0.5 d in astigmatic power and over 20 in the astigmatic axis were found , according to the distance between the tunnel and sideport incisions separately for the left and right eyes are presented in table 5 ; cases further considering the type of astigmatism ( wtr , atr ) are presented in table 6 .
the proportion of left eyes where the change over 0.5 d in astigmatic power from preoperative measures to the 1st month were found to be significantly greater in cases where the distance between the tunnel and sideport incisions was < 90 or > 110 , as compared with cases where the distance between tunnel and sideport incisions was from 90110. furthermore , a change over 20 in the astigmatic axis from preoperative measures to the 1st month was significantly greater in cases where the distance between tunnel and sideport incisions was < 90 or > 110 , as compared with cases where the distance between the tunnel and sideport incisions was from 90110. when multiple logistic regression analysis was conducted ( table 7 ) with the dependent variable ( the presented change over 0.5 d in astigmatic power [ preoperative to 1st month ] ) , and after adjusting for the eye ( right or left ) , it was found that cases with a > 110 distance between the tunnel and sideport incisions had a 2.22 times greater likelihood of exhibiting a change over 0.5 d in astigmatic power ( preoperative to 1st month ) as compared with cases with a 90110 distance between the tunnel and sideport incisions .
also , it was found that wtr cases were less likely to have a change over 0.5 d in astigmatic power ( preoperative to 1st month ) in comparison with the atr cases .
multiple analyses for a change over 0.5 d in astigmatic power ( preoperative to the 6th month ) showed that cases with a > 110 distance between the tunnel and sideport incisions had a 3.45 times greater likelihood of exhibiting a change over 0.5 d in astigmatic power ( preoperative to the 6th month ) , as compared with cases with a 90110 distance between the tunnel and sideport incisions . in terms of the change in the corneal astigmatic axis
, it was found that cases with a < 90 distance between the tunnel and sideport incisions had a 4.18 times greater likelihood of exhibiting a change over 20 in the astigmatic axis ( preoperative to the 1st month ) , as compared with cases with a 90110 distance .
furthermore , during multiple analyses , it was found that wtr cases were less likely to have a change over 20 in the astigmatic axis ( preoperative to the 6th month ) in comparison with atr cases .
the interaction of distance between the tunnel and sideport incisions with type of astigmatism was not significant in any of the logistic models , indicating that the effect of distance between the tunnel and sideport incisions was similar in the two types of astigmatism .
the factors affecting corneal astigmatism in cataract surgery are those related to the eye ( right or left , corneal diameter , and power and type of astigmatism ) , the incision ( size , location , and configuration ) , and the surgical technique ( micro - incision cataract surgery , small incision cataract surgery , coaxial , and biaxial ) .
there is growing literature regarding the changes in astigmatism after cataract surgery.113 however , most studies fail to account for the multitude of related factors . a main incision of standard size and location ( superotemporal region for the right eye and superonasal region for the left eyes ; three - step ; clear corneal ; 3.0 mm ) and a sideport incision at different predetermined distances from the main incision ( < 90 , 90110 , >
second , it is a fact that in different regions , the corneal thickness differs .
for example , the inferotemporal cornea is considered to be the thinnest region.17,18 in order to eliminate confounding factors that could affect postoperative astigmatism , we preferred to perform the tunnel incision in a standard location and classifies the eyes into right and left , so as to eliminate the different regional corneal thicknesses and distances from the optical center of the cornea .
eyes with oblique astigmatism were excluded due to a limited sample , which would preclude a safe analysis .
moreover , we included eyes with 11.512.5 mm horizontal corneal diameter because , considering that the cornea is a sphere and using the well - known 2 formula , a corneal diameter of 11.0 mm has a 34.54 mm perimeter , while a corneal diameter of 13.0 mm has a 40.82 mm perimeter . since our main incision is 3.0 mm in width , a smaller cornea would be more affected.19 furthermore , in small corneas , the main incision is located closer to the optical center in comparison with a large cornea .
thus , we created three groups ; in each one , the only variable factor was the distance between the incisions .
gauss s law of elastic domes states that for every change in curvature in one meridian , there is an equal and opposite change 90 away.20 our hypothesis was based on cravy s modification of gauss s law , in which compression in one axis results in an equal expansion in the other axis.21,22 this is also known as the coupling effect , where corneal incisions change the balance of forces , redistribute the tension vectors , and lead to flattening of the incisional meridian , with simultaneous bending of the orthogonal meridian .
according to alpins and walsh , there is no such thing as a completely astigmatically neutral incision.23 any incision , no matter how small , will still affect the corneal structure and alter the astigmatic magnitude and/or direction.23 we assume that the sideport incision , despite its small width , still promotes changes in corneal curvature . when the distance between the main and sideport incision is 90100 , a mutual neutralization of the corneal forces occurs.2426 in right eyes , the main incision is performed superotemporally and the sideport incision is performed nasally . since nasal incisions affect astigmatism more than temporal incisions,13,27 we assume that this is valid for sideport incisions as well , despite their smaller width .
this means that in right eyes , the mutual neutralization phenomenon would lead to a lesser astigmatic change when compared with the left eye ( in which case , the main incision is done superonasally and the sideport incision is done temporally ) .
this is confirmed by findings in other studies , in which the left eyes are more affected than the right eyes.6,7 changes in corneal astigmatism > 0.5 d and changes in the astigmatic axis > 20 are observed in cases when the incision distance is < 90 and > 110. it is a fact that most surgeons generally prefer to perform the sideport incision at a 90 distance from the main incision for easier handling of the surgical instruments during the phacoemulsification stage .
when the distance between incisions is < 90 ( or > 110 ) , the bending forces act on different axes and affect the power of astigmatism and/or produce a greater torque of the astigmatism axis , as shown by our results . the disparity in the axis of the cylinder between
the operated and the non - operated eye leads to meridional aniseikonia , which is poorly tolerated by the patient .
a temporal main incision is considered as astigmatically neutral due to the greater distance from the optical corneal center , the lesser wound stress produced by the phacoprobe,27,28 and the thinner cornea at that site.17,18 for right - handed surgeons that operate only from the superior position ( above the patient s head ) , we propose that in order to produce an incision that is as astigmatically neutral as possible , they should perform a sideport incision at the 90110 distance from the main incision ( figure 1 ) .
this way , one avoids augmentation of the astigmatic power , and it also maintains the corneal enantiomorphism between the left and right eyes29 thanks to the lesser torque of the astigmatic axis .
a limitation of our study is the use of anterior surface corneal topography and the unavailability of pachymetry .
thin corneas are related to more corneal deformation or sia after cataract surgery . knowing the corneal thickness gives us the opportunity to exclude another factor that could affect our results in this case , very thin or thick corneas .
in the future , we propose that cases with greater astigmatism and different main incision locations are studied , taking into consideration corneal pachymetry . also , some surgeons make two sideport incisions and a further study may show which has the ideal distance between these three incisions . in this way , we can better elucidate the corneal biomechanics , thus enabling us to formulate a better surgical plan . | ### Summary:
: purposeto study the changes in corneal astigmatism after cataract surgery when the sideport incision is performed at a predetermined location away from the tunnel incision.settinggeneral hospital of piraeus tzaneio , attiki , greece.materials and methodsa total of 333 eyes with corneal astigmatism 1.5 diopters ( d ) underwent cataract surgery .
a three - step superotemporal clear corneal incision for the right eye and a superonasal clear corneal incision for the left eye ( 3.0 mm ) was made , while the sideport incision was located at < 90 , 90110 , and > 110. keratometric data were measured with corneal topography eyesys vista 2000 pre- and postoperatively at the 1st and 6th month .
surgically induced astigmatism was calculated by vector analysis .
we noted all cases in which a change > 0.5 d in corneal astigmatic power occurred , as well as a change > 20 in axis torque , despite axis direction.resultsafter multiple logistic regression analysis was conducted , cases with > 110 distance between the tunnel and sideport incision had 2.22 times ( p=0.021 ) greater likelihood for having changed > 0.5 d in astigmatic power at the 1st month and 3.45 times ( p=0.031 ) at the 6th month postoperatively , as compared with cases with a 90110 distance between the tunnel and sideport incision .
as for the change in the astigmatic axis , cases with < 90 distance had a 4.18 times greater likelihood for having a change > 20 ( p<0.001 ) ( preoperative to 1st month ) as compared with cases having 90110 of distance.conclusionfor surgeons that operate only from the superior position , we propose that in order to produce an incision that is as astigmatically neutral as possible , they should perform the sideport incision at a 90110 distance . |
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: urinary incontinence ( ui ) in women has been claimed as a social disease thus its frequency has exceeded 5% .
incontinence may take various forms : urge incontinence , stress incontinence , and mixed incontinence are the three main types .
ui risk factors have been classified as urogynecological , constitutional , neurological , and behavioral .
the anatomic structures that prevent urinary incontinence during elevations in abdominal pressure , can be divided into 2 systems : a sphincteric system and a supportive system .
the action of the vesical neck and urethral sphincteric mechanisms at rest constrict the urethral lumen and keep urethral closure pressure higher than bladder pressure .
the striated urogenital sphincter , the smooth muscle sphincter in the vesical neck , and the circular and longitudinal smooth muscle of the urethra all contribute to closure pressure .
the mucosal and vascular tissues that surround the lumen provide a hermetic seal , and the connective tissues in the urethral wall also aid coaptation .
decreases in striated muscle sphincter fibers occur with age and parity [ 1 , 2 ] .
the persistent increased pelvic pressure , which is a result of hormone changes and increased uterine during pregnancy , leads to the damage of pelvic tissue . during vaginal delivery ,
the extremely stretched pelvic tissue resulted in the structure changes of muscles and supporting tissue around urethra , and ultimately induces urinary incontinence .
the fascial and muscular components within the pelvic floor create a support mechanism that facilitates storage and voiding of urine .
their constituents are mainly fibrillar collagens i and iii responsible for maintaining tensile strength . stretching and recoiling
is enabled by the elastic fibers consisting of elastin on a scaffold of microfibrils , fibrillin-1 and-2 . in the assembly of the elastic fibers different elastin associated proteins are involved , among them the fibulins [ 39 ] .
urinary incontinence is in part attributed to qualitative and quantitative changes in connective tissue of the urogenital tract .
it is reported that some of the smooth muscles from women with stress urinary incontinence appeared to show atrophy , apomorphosis , or apoptosis .
it was discovered that women with pelvic organ prolapse had collagen degradation and elastic proteins reduction e.g. fibulin-5 , elastin , smooth muscle actin , myosin heavy chain , and caldesmon [ 1115 ] .
calpains have been implicated in basic cellular processes including cytoskeletal rearrangements , different signal transduction pathways , and cell apoptosis . in pathological status ,
abnormal elevation of ca activates calpains , which accelerate the degradation of various cytoskeleton , and ultimately induces the tissue damages .
although our current understanding of the mechanisms underlying these processes remains limited , recent studies have begun to shed light on this subject . here ,
we discuss advances that have provided insight into where calpains fit into the elastic proteins structure , and how the activities of calpains are modulated . calpains ( calcium - activated non - lysosomal proteases ; capn ) were originally identified as a unique class of calcium activated proteolytic enzymes present in the cytosolic fraction of brain extracts .
these proteases were later named calpains to reflect their calcium dependency and homology with the protease domain of the papain family of cysteine proteases ( papain , caspases , and cathepsin b , l , and s ) [ 16 , 17 ] .
molecular biological studies have shown that calpains constitute a superfamily , which exists ubiquitously in organisms ranging from humans to microorganisms , and showing limited proteolytic activity at neutral ph .
calpains result in the proteolysis of a broad spectrum of cellular proteins and a distinguishing feature of their activity is their ability to confer limited cleavage of protein substrates into stable fragments rather than complete proteolytic digestion .
calpains are regarded as a bio - modulators , because properties of the substrate proteins are often modulated upon hydrolysis by calpain .
therefore , calpains are considered a representative of the intracellular modulator proteases that govern various cellular functions such as signal transduction and cell morphogenesis [ 18 , 19 ] .
humans have 15 genes that encode a calpain - like protease domain , and they generate diverse kinds of calpain homologues with combinations of several functional domains such as ca - binding domains and transmembrane domains . among the best studied calpains are mammalian -calpain ( also called calpain-1 or capn ) and m - calpain ( also called calpain-2 or mcapn ) , which are called the conventional calpains .
they are mainly localized in the cytosol , show ubiquitous expression , and exhibit ca - dependent proteolytic activity .
they are both heterodimers and consist of a large ( 80k ) distinct - and m - calpain catalytic subunits , and a common small ( 30k ) calpain regulatory subunit . the 80k of and m - calpains isolated by dissociation in urea and that obtained by expression of the cdna possess a full protease activity if properly folded , indicating that 30k is not essential for protease activity [ 18 , 19 ] .
30k also plays a role as a chaperon and is essential for 80k to have correct conformation .
calpains are regulated by their interacting partner , the endogenous calpain inhibitor calpastatin , which is encoded by the cast gene [ 16 , 18 , 20 ] . actually , 15 human calpain genes have been numbered , capn13 and 5 - 16 .
the other two genes encode smaller regulatory proteins that associate with some of the catalytic subunits to form heterodimeric proteases .
several calpain isoforms are ubiquitously expressed , whereas many demonstrate tissue - specific expression patterns .
within the cell , the localization patterns of calpains are complex and somewhat variable , which means that their subcellular localization might be dynamically regulated and constitutes an important factor in the modulation of their functions [ 18 , 21 , 22 ] .
table 1 shows the calpains expression patterns in both tissues , as well as in the cell .
human calpain related genes , expression patterns and localization of its protein products [ 16 , 18 , 23 ] .
not yet detected the catalytic ( large ) and regulatory ( small ) subunits of conventional calpains can be divided into four ( i - iv ) and two domains ( v - vi ) , respectively ( fig .
domain i is present at the n - terminus of some calpains , and interacts with domain vi of the noncatalytic ( small ) subunits and may be important for stability .
the protease domain ii is composed of two subdomains ( iia and iib ) with its substrate binding cleft in - between .
domain iii consists of eight -strands arranged in a -sandwich , a structure very similar to tnf- & and the c2-domains found in various ca - regulated proteins such as protein kinase c isoforms and synaptotagmin .
domains iv and vi in the large and small subunits , respectively , contain five sets of ef - hand ca binding motifs similar to those found in calmodulin . the extreme cooh - terminal fifth ef - hand motif in iv and vi can not bind ca but interacts with each other to assemble heterodimers
. domain v of the small subunits appears to have a very flexible structure as a consequence of being glycine rich .
this domain is thought to interact with plasma membrane and/or membrane proteins through hydrophobic interactions .
typical calpains are composed of four domains ( i iv ) , whereas in the case of atypical calpains , certain domains of typical calpains have been deleted or replaced .
the small subunit of calpain is composed of two domains ( v and vi ) .
symbols used are : i the n - terminal regulatory domain ; ila and lib the protease subdomains containing the active sites , cys and his + asn , respectively ; iii - the c2-like ca - binding domain ; iv and vi five ef -hand containing ca - binding pef domain ; v glycine - rich hydrophobic domain ; mit microtubule interacting and trafficking domain ; ns , is1 , and is2
calpain-3-specific sequences ; soh sol subfamily homology domain ; solh small optic lobe homology ; zn- zn - finger motif - containing domain .
calpain exists in the cytosol as an inactive enzyme and translocates to membranes in response to increases in the cellular ca level .
the ca concentration required for proteolytic and other activities of the calpains are much higher than the 50 - 300 nm ca that exist in living cells .
studies have also described molecules that seemed to reduce the ca requirements of the calpains in in vitro assays .
for example , isovalerylcarnitine reduces the ca concentration required for maximal proteolytic activity of calpain-2 and increases its specific activity . at the membrane , calpain
is activated in the presence of ca and phospholipids . because calpains contain calcium - binding ef - hand motifs in domains iv and vi and because domain iv of calpain-1 and domain iv of calpain-2 are different , these were originally presumed to be responsible for the calcium dependent activation of calpains .
furthermore , functional studies have demonstrated that domain ii alone exhibits calcium - dependent protease activity and that non - ef - hand calcium - binding sites within the protease domain act as a calcium switch to align the catalytic triad [ 2628 ] .
autocatalytic hydrolysis of domain i take place during activation , and dissociation of 30k from 80k occurs as a result .
activated calpain or 80k hydrolyzes substrate proteins at membranes or in cytosol after release from membranes , and has a lower requirement for calcium . in the absence of ca , two protease subdomains iia and iib
ca - induced structural changes that release the constraints are prerequisite for activation to form a functional catalytic site [ 18 , 24 ] .
calpain-2 is activated by phosphorylation of ser50 by the erk ( extracellular signal - regulated protein kinase ) , mitogen - activated protein ( map ) kinase and by egf - induced pathway whereas calpain-1 does not contain a phosphorylatable site in this region .
mekk1 associates with focal adhesion kinase ( fak ) in adhesion complexes and appears to act upstream of erk in the regulation of calpain-2 activation .
cyclic - amp - mediated activation of protein kinase a ( pka ) can block eqf - induced activation of calpain-2 .
this appears to occur through phosphorylation of calpain-2 by pka , which probably restricts domain movement and freezes calpain-2 to an inactive conformation .
the residues in calpain-2 ( ser369 and thr370 ) that appear to be the protein kinase a targets are conserved in other calpains , which suggests that phosphorylation of domain iii represents yet another mechanism for regulating calpain activity [ 31 , 32 ] .
in addition , pka reduces calpain-2 activity by blocking phosphatidylinositol-4,5-bisphosphate ( pip2 ) binding in the c2 domain of calpain .
recent observations indicate that pip2 acts as a cofactor for calpain-2 and that phosphorylation by erk or pka alters the cellular distribution of the enzyme to modulate activity .
localization of calpain-2 at the plasma membrane , through pip2 anchorage , is important for the activation of the protease [ 33 , 34 ] .
the binding of phospholipids also decreases the calcium requirement for calpains in vitro
. during the initial studies on purifying calpain-2
, it was discovered that muscle extracts having calpain activity also contained a calpain inhibitor .
it consists of an n - terminal l domain that contains an n - terminal xl region , and four repetitive inhibitory domains ( i - iv ) .
the intrinsically unstructured nature of calpastatin allows it to reversibly inhibit up to four calpain heterodimers .
the equilibrium binding of calpains to calpastatin is extremely ph sensitive and decreases as ph decreases .
immunolocalization results suggest that the calpains and calpastatin are frequently localized in cells , so the cells must possess some mechanism to allow calpain activity in the presence of calpastatin .
otherwise , increased ca concentrations would cause calpastatin binding before the calpains could initiate any proteolytic activity [ 28 , 37 ] .
experiments of the binding of autolytic fragments of calpains to calpastatin indicated that calpastatin bound to both domains iv and vi of the calpain molecule .
subsequent studies using expressed subdomains of the calpastatin molecule showed that a 14-amino acid subdomain was conserved around the four domains of the calpastatin molecule and bound specifically to domain iv of calpain in a ca dependent manner .
research showed that optimal conditions for in vitro calpain activity were ph 7.5 at 25c .
factors such as the reduced solubility of calcium at low ph and temperatures or extraction buffer ph could affect calpain activity . unless the homogenate is kept above ph 6.5
dysfunction of smooth muscle and connective tissue appears to be directly related to the phenomenon of urinary incontinence in women . particularly important
are the proteolytic mechanisms that may change the structural and functional properties of proteins forming the urogenital system .
while the sliding filament model adequately describes the basic mechanism of contraction in all muscle types , there are significant differences between skeletal and smooth muscle .
an appreciation of these differences stems from the observation that although smooth muscle lacks troponin , its contractile activity is still regulated by cytoplasmic calcium levels [ 39 , 40 ] .
in addition to the major contractile proteins actin and myosin , smooth muscle cells contain numerous proteins involved in the regulation of contraction .
actin and myosin are the contractile proteins and form the actin and myosin filaments of the myofibril .
cross - bridges are formed between the actin and myosin filaments and conformational changes in myosin generate the contractile force during contraction . in the relaxed state , a muscle generates very little tension , and can easily be stretched by a force pulling on it .
this means that there are no cross - bridges between actin and myosin filaments and the filaments of each sarcomere slide passively over one another .
in contrast to actin and myosin , tropomyosin plays the role of regulatory protein and assists in turning the contractile process on and off [ 39 , 40 ] .
in addition to the major contractile proteins actin and myosin , smooth muscle cells contain numerous proteins involved in the regulation of contraction , such as such as caldesmon , calponin , and tropomyosin ( strengthens microfilaments ) ; in regulation of microfilament stability , such as gelsolin ( fragments microfilaments ) ; in organization of the microfilament network , such as filamin ( crosslinks microfilaments ) , -actinin , and fimbrin ( bundle microfilaments ) ; and a set of proteins involved in the attachment of microfilaments to plasma membrane , such as vinculin , talin , paxillin , and tensin . the major proteins of the intermediate filament system in smooth muscle cells are desmin and vimentin [ 41 , 42 ] .
many contractile and cytoskeletal proteins have muscle - specific variants that can be used as smooth muscle cell phenotypic markers : - and --smooth muscle actins , smooth muscle myosin heavy chains sm-1 and sm-2 , meta- and -vinculin , desmin , heavy ( h)-caldesmon , smooth muscle -tropomyosin , and calponin . a significant portion of these proteins are substrates for calpains [ 40 , 43 ] .
so far , two experimental papers were published on the expression of calpains in material derived from women with urinary incontinence and uterovaginal prolapse .
wu et al . found overexpression of calpain-2 and low expression of calpastatin in periurethral vaginal tissues that were taken at 1 - 1.5 cm below the urinary meatus . in the studied material mucosa , submucosa , connective tissue , and smooth muscle
, chen and coworkers studied the expression of calpain-1 and calpain-2 in the vaginal walls of women with and without uterovaginal prolapse .
they conclude that calpain expression may be compromised in the anterior vaginal wall of women with uterovaginal prolapse who have abnormal histologic changes in the vaginal connective tissues or have anterior vaginal laxity .
although the mechanism of calpain action in these tissues is not clear , it can be assumed that it is linked to proteolysis of structural proteins , both smooth muscle and connective tissue .
croall et al . , found that the calmodulin binding proteins , caldesmon and calponin , are cleaved by both major isoforms of calpain in vitro
.
qualitatively , the cleavage pattern of each substrate is unchanged by the presence or absence of calmodulin suggesting that the interaction between calmodulin and these calmodulin - binding proteins does not alter substrate recognition by calpain .
authors conclude that calmodulin - binding domains do not provide substrate recognition sites for calpains .
it seems likely that the calmodulin - like regions of calpain function to bind calcium and to regulate enzyme conformation as required for activity and that they do not interact directly with most substrates .
similar results were obtained for calponin by tsunekawa and coworkers . in turn , yoshimoto et al .
, suggested that acidic calponin , an actin binding protein expressed in smooth muscle , is also cleaved by calpain , and this protein might be involved in the calpain - regulated actin cytoskeleton .
yoshida et al . , demonstrated proteolysis of two important cytoskeletal proteins , actin and vimentin , in the lens fiber cells by calpain .
connective tissue is the most important part of pelvic supporting tissue , which maintains the flexibility and toughness of pelvic floor .
it is reported that collagenolytic activity might be related with the occurrence of urinary incontinence [ 5052 ] .
von wnuck lipinski and coworkers found that collagen i and iii fragments proteolytically released from the extracellular matrix by matrix metalloproteinases may propagate apoptosis of smooth muscle cells by calpain - mediated inactivation of anti - apoptotic proteins such as x - chromosome - linked inhibitor of apoptosis ( xiap ) [ 53 , 54 ] .
they suggest that degraded collagen fragments simultaneously activated an apoptotic pathway triggered by calpain / caspase activation and a survival pathway triggered by nf-b activation .
the survival pathway was dominant over the apoptotic as substantial cell death took place only after inactivation of nf-b .
calpains ( calcium - activated non - lysosomal proteases ; capn ) were originally identified as a unique class of calcium activated proteolytic enzymes present in the cytosolic fraction of brain extracts .
these proteases were later named calpains to reflect their calcium dependency and homology with the protease domain of the papain family of cysteine proteases ( papain , caspases , and cathepsin b , l , and s ) [ 16 , 17 ] .
molecular biological studies have shown that calpains constitute a superfamily , which exists ubiquitously in organisms ranging from humans to microorganisms , and showing limited proteolytic activity at neutral ph .
calpains result in the proteolysis of a broad spectrum of cellular proteins and a distinguishing feature of their activity is their ability to confer limited cleavage of protein substrates into stable fragments rather than complete proteolytic digestion .
calpains are regarded as a bio - modulators , because properties of the substrate proteins are often modulated upon hydrolysis by calpain .
therefore , calpains are considered a representative of the intracellular modulator proteases that govern various cellular functions such as signal transduction and cell morphogenesis [ 18 , 19 ] .
humans have 15 genes that encode a calpain - like protease domain , and they generate diverse kinds of calpain homologues with combinations of several functional domains such as ca - binding domains and transmembrane domains . among the best studied calpains are mammalian -calpain ( also called calpain-1 or capn ) and m - calpain ( also called calpain-2 or mcapn ) , which are called the conventional calpains .
they are mainly localized in the cytosol , show ubiquitous expression , and exhibit ca - dependent proteolytic activity .
they are both heterodimers and consist of a large ( 80k ) distinct - and m - calpain catalytic subunits , and a common small ( 30k ) calpain regulatory subunit .
the 80k of and m - calpains isolated by dissociation in urea and that obtained by expression of the cdna possess a full protease activity if properly folded , indicating that 30k is not essential for protease activity [ 18 , 19 ] .
30k also plays a role as a chaperon and is essential for 80k to have correct conformation .
calpains are regulated by their interacting partner , the endogenous calpain inhibitor calpastatin , which is encoded by the cast gene [ 16 , 18 , 20 ] .
actually , 15 human calpain genes have been numbered , capn13 and 5 - 16 .
the other two genes encode smaller regulatory proteins that associate with some of the catalytic subunits to form heterodimeric proteases .
several calpain isoforms are ubiquitously expressed , whereas many demonstrate tissue - specific expression patterns .
within the cell , the localization patterns of calpains are complex and somewhat variable , which means that their subcellular localization might be dynamically regulated and constitutes an important factor in the modulation of their functions [ 18 , 21 , 22 ] .
table 1 shows the calpains expression patterns in both tissues , as well as in the cell .
human calpain related genes , expression patterns and localization of its protein products [ 16 , 18 , 23 ] .
the catalytic ( large ) and regulatory ( small ) subunits of conventional calpains can be divided into four ( i - iv ) and two domains ( v - vi ) , respectively ( fig .
domain i is present at the n - terminus of some calpains , and interacts with domain vi of the noncatalytic ( small ) subunits and may be important for stability .
the protease domain ii is composed of two subdomains ( iia and iib ) with its substrate binding cleft in - between .
domain iii consists of eight -strands arranged in a -sandwich , a structure very similar to tnf- & and the c2-domains found in various ca - regulated proteins such as protein kinase c isoforms and synaptotagmin .
domains iv and vi in the large and small subunits , respectively , contain five sets of ef - hand ca binding motifs similar to those found in calmodulin .
the extreme cooh - terminal fifth ef - hand motif in iv and vi can not bind ca but interacts with each other to assemble heterodimers .
domain v of the small subunits appears to have a very flexible structure as a consequence of being glycine rich .
this domain is thought to interact with plasma membrane and/or membrane proteins through hydrophobic interactions .
typical calpains are composed of four domains ( i iv ) , whereas in the case of atypical calpains , certain domains of typical calpains have been deleted or replaced .
the small subunit of calpain is composed of two domains ( v and vi ) .
symbols used are : i the n - terminal regulatory domain ; ila and lib the protease subdomains containing the active sites , cys and his + asn , respectively ;
iii - the c2-like ca - binding domain ; iv and vi five ef -hand containing ca - binding pef domain ; v glycine - rich hydrophobic domain ; mit microtubule interacting and trafficking domain ; ns , is1 , and is2 calpain-3-specific sequences ; soh sol subfamily homology domain ; solh small optic lobe homology ; zn- zn - finger motif - containing domain .
calpain exists in the cytosol as an inactive enzyme and translocates to membranes in response to increases in the cellular ca level . the ca concentration required for proteolytic and other activities of the calpains
are much higher than the 50 - 300 nm ca that exist in living cells .
studies have also described molecules that seemed to reduce the ca requirements of the calpains in in vitro assays .
for example , isovalerylcarnitine reduces the ca concentration required for maximal proteolytic activity of calpain-2 and increases its specific activity . at the membrane , calpain is activated in the presence of ca and phospholipids . because calpains contain calcium - binding ef - hand motifs in domains iv and vi and because domain iv of calpain-1 and domain iv of calpain-2 are different , these were originally presumed to be responsible for the calcium dependent activation of calpains .
furthermore , functional studies have demonstrated that domain ii alone exhibits calcium - dependent protease activity and that non - ef - hand calcium - binding sites within the protease domain act as a calcium switch to align the catalytic triad [ 2628 ] .
autocatalytic hydrolysis of domain i take place during activation , and dissociation of 30k from 80k occurs as a result .
activated calpain or 80k hydrolyzes substrate proteins at membranes or in cytosol after release from membranes , and has a lower requirement for calcium . in the absence of ca , two protease subdomains iia and iib
ca - induced structural changes that release the constraints are prerequisite for activation to form a functional catalytic site [ 18 , 24 ] .
calpain-2 is activated by phosphorylation of ser50 by the erk ( extracellular signal - regulated protein kinase ) , mitogen - activated protein ( map ) kinase and by egf - induced pathway whereas calpain-1 does not contain a phosphorylatable site in this region .
mekk1 associates with focal adhesion kinase ( fak ) in adhesion complexes and appears to act upstream of erk in the regulation of calpain-2 activation .
cyclic - amp - mediated activation of protein kinase a ( pka ) can block eqf - induced activation of calpain-2 .
this appears to occur through phosphorylation of calpain-2 by pka , which probably restricts domain movement and freezes calpain-2 to an inactive conformation .
the residues in calpain-2 ( ser369 and thr370 ) that appear to be the protein kinase a targets are conserved in other calpains , which suggests that phosphorylation of domain iii represents yet another mechanism for regulating calpain activity [ 31 , 32 ] .
in addition , pka reduces calpain-2 activity by blocking phosphatidylinositol-4,5-bisphosphate ( pip2 ) binding in the c2 domain of calpain .
recent observations indicate that pip2 acts as a cofactor for calpain-2 and that phosphorylation by erk or pka alters the cellular distribution of the enzyme to modulate activity .
localization of calpain-2 at the plasma membrane , through pip2 anchorage , is important for the activation of the protease [ 33 , 34 ] .
the binding of phospholipids also decreases the calcium requirement for calpains in vitro
. during the initial studies on purifying calpain-2
, it was discovered that muscle extracts having calpain activity also contained a calpain inhibitor .
it consists of an n - terminal l domain that contains an n - terminal xl region , and four repetitive inhibitory domains ( i - iv ) .
the intrinsically unstructured nature of calpastatin allows it to reversibly inhibit up to four calpain heterodimers .
the equilibrium binding of calpains to calpastatin is extremely ph sensitive and decreases as ph decreases .
immunolocalization results suggest that the calpains and calpastatin are frequently localized in cells , so the cells must possess some mechanism to allow calpain activity in the presence of calpastatin .
otherwise , increased ca concentrations would cause calpastatin binding before the calpains could initiate any proteolytic activity [ 28 , 37 ] .
experiments of the binding of autolytic fragments of calpains to calpastatin indicated that calpastatin bound to both domains iv and vi of the calpain molecule .
subsequent studies using expressed subdomains of the calpastatin molecule showed that a 14-amino acid subdomain was conserved around the four domains of the calpastatin molecule and bound specifically to domain iv of calpain in a ca dependent manner .
research showed that optimal conditions for in vitro calpain activity were ph 7.5 at 25c .
factors such as the reduced solubility of calcium at low ph and temperatures or extraction buffer ph could affect calpain activity .
unless the homogenate is kept above ph 6.5 , calpain activity reduces significantly because the enzyme is precipitated .
dysfunction of smooth muscle and connective tissue appears to be directly related to the phenomenon of urinary incontinence in women . particularly important
are the proteolytic mechanisms that may change the structural and functional properties of proteins forming the urogenital system .
while the sliding filament model adequately describes the basic mechanism of contraction in all muscle types , there are significant differences between skeletal and smooth muscle .
an appreciation of these differences stems from the observation that although smooth muscle lacks troponin , its contractile activity is still regulated by cytoplasmic calcium levels [ 39 , 40 ] .
in addition to the major contractile proteins actin and myosin , smooth muscle cells contain numerous proteins involved in the regulation of contraction .
actin and myosin are the contractile proteins and form the actin and myosin filaments of the myofibril .
cross - bridges are formed between the actin and myosin filaments and conformational changes in myosin generate the contractile force during contraction . in the relaxed state , a muscle generates very little tension , and can easily be stretched by a force pulling on it .
this means that there are no cross - bridges between actin and myosin filaments and the filaments of each sarcomere slide passively over one another .
in contrast to actin and myosin , tropomyosin plays the role of regulatory protein and assists in turning the contractile process on and off [ 39 , 40 ] .
in addition to the major contractile proteins actin and myosin , smooth muscle cells contain numerous proteins involved in the regulation of contraction , such as such as caldesmon , calponin , and tropomyosin ( strengthens microfilaments ) ; in regulation of microfilament stability , such as gelsolin ( fragments microfilaments ) ; in organization of the microfilament network , such as filamin ( crosslinks microfilaments ) , -actinin , and fimbrin ( bundle microfilaments ) ; and a set of proteins involved in the attachment of microfilaments to plasma membrane , such as vinculin , talin , paxillin , and tensin .
the major proteins of the intermediate filament system in smooth muscle cells are desmin and vimentin [ 41 , 42 ] .
many contractile and cytoskeletal proteins have muscle - specific variants that can be used as smooth muscle cell phenotypic markers : - and --smooth muscle actins , smooth muscle myosin heavy chains sm-1 and sm-2 , meta- and -vinculin , desmin , heavy ( h)-caldesmon , smooth muscle -tropomyosin , and calponin . a significant portion of these proteins are substrates for calpains [ 40 , 43 ] .
so far , two experimental papers were published on the expression of calpains in material derived from women with urinary incontinence and uterovaginal prolapse .
found overexpression of calpain-2 and low expression of calpastatin in periurethral vaginal tissues that were taken at 1 - 1.5 cm below the urinary meatus . in the studied material mucosa , submucosa , connective tissue , and smooth muscle
chen and coworkers studied the expression of calpain-1 and calpain-2 in the vaginal walls of women with and without uterovaginal prolapse .
they conclude that calpain expression may be compromised in the anterior vaginal wall of women with uterovaginal prolapse who have abnormal histologic changes in the vaginal connective tissues or have anterior vaginal laxity .
although the mechanism of calpain action in these tissues is not clear , it can be assumed that it is linked to proteolysis of structural proteins , both smooth muscle and connective tissue .
croall et al . , found that the calmodulin binding proteins , caldesmon and calponin , are cleaved by both major isoforms of calpain in vitro
.
qualitatively , the cleavage pattern of each substrate is unchanged by the presence or absence of calmodulin suggesting that the interaction between calmodulin and these calmodulin - binding proteins does not alter substrate recognition by calpain .
authors conclude that calmodulin - binding domains do not provide substrate recognition sites for calpains .
it seems likely that the calmodulin - like regions of calpain function to bind calcium and to regulate enzyme conformation as required for activity and that they do not interact directly with most substrates .
similar results were obtained for calponin by tsunekawa and coworkers . in turn , yoshimoto et al .
, suggested that acidic calponin , an actin binding protein expressed in smooth muscle , is also cleaved by calpain , and this protein might be involved in the calpain - regulated actin cytoskeleton .
yoshida et al . , demonstrated proteolysis of two important cytoskeletal proteins , actin and vimentin , in the lens fiber cells by calpain .
connective tissue is the most important part of pelvic supporting tissue , which maintains the flexibility and toughness of pelvic floor .
it is reported that collagenolytic activity might be related with the occurrence of urinary incontinence [ 5052 ] .
von wnuck lipinski and coworkers found that collagen i and iii fragments proteolytically released from the extracellular matrix by matrix metalloproteinases may propagate apoptosis of smooth muscle cells by calpain - mediated inactivation of anti - apoptotic proteins such as x - chromosome - linked inhibitor of apoptosis ( xiap ) [ 53 , 54 ] .
they suggest that degraded collagen fragments simultaneously activated an apoptotic pathway triggered by calpain / caspase activation and a survival pathway triggered by nf-b activation .
the survival pathway was dominant over the apoptotic as substantial cell death took place only after inactivation of nf-b .
calpain activity contributes to remodeling of the actin cytoskeleton , cell migration , and oncogenic transformation .
structurefunction relationships for various calpain family members is now providing valuable insights into the complex regulation of these proteases and should help to design therapies for disorders involving calpain activation in the future . | ### Summary:
: the fascial and muscular components within the pelvic floor create a support mechanism that facilitates storage and voiding of urine .
their constituents are mainly fibrillar collagens i and iii , which are responsible for maintaining tensile strength . stretching and recoiling is enabled by the elastic fibers consisting of elastin on a scaffold of microfibrils , fibrillin-1 and -2 .
calpains are intracellular ca2 + -dependent cysteine proteases found in almost all eukaryotes and some bacteria .
calpains display limited proteolytic activity at neutral ph , proteolyzing substrates to transform and modulate their structures and activities , and are therefore called modulator proteases . by making selective limited proteolytic cleavages
, they modulate the activity of enzymes , including key signaling molecules , and induce specific cytoskeletal rearrangements , accounting for their roles in signal transduction and structural stabilization . understanding these mechanisms
should provide avenues for novel therapeutic strategies to treat pathological processes such as urinary incontinence and pelvic prolapse . |
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: the normal function of the nervous system relies on a complex and precise network of neuronal connections . to establish a connection with its target cell during development
, a neuron sends out an axon , which often travels over relatively long distance towards the target region in response to guidance cues present in the surrounding environment ( i.e. axon guidance ) 1 . after reaching the target region , the axon shuts down motility in response to specific targeting signals and subsequently selects a specific target cell within the target field for establishing synaptic connections ( i.e. target recognition ) .
the movement of an axon is directed by the growth cone , a sensorimotor structure located at the leading edge of a growing axon .
the growth cone possesses sophisticated signaling systems that allow cell surface receptors to communicate with the actin cytoskeleton , thus rapidly converting extracellular guidance and targeting signals into directed movement or the arrest of outgrowth 2 , 3 .
accumulated evidence supports that the signaling mechanisms linking growth - cone receptors to the actin cytoskeleton are evolutionarily conserved and appear to be utilized in many other biological processes that require dynamic remodeling of the actin cytoskeleton 2 , 3 .
thus , the dissection of the growth - cone signaling systems not only helps to understand the mechanism of axon guidance and target recognition during neural development , but also sheds light on the general signaling mechanisms underlying the restructuring of the actin cytoskeleton in response to extracellular signals . during past two decades
, a combination of biochemical , immunological and genetic studies in both vertebrates and invertebrates have led to significant progress on the understanding of the molecular mechanism of axon guidance and target recognition 1 , 2 , 3 .
a number of growth - cone receptors that detect short - range or long - range cues have been identified .
the mechanisms by which these receptors transduce the guidance and targeting signals into the changes in the actin cytoskeleton are also beginning to emerge . in this review
, i will focus on discussing the recent progress on the dissection of the nck / dock signaling pathways for regulating photoreceptor ( r cell ) axon guidance and target recognition in the drosophila visual system .
the wiring of neural network in the drosophila visual system has been proven to be a powerful model system for genetic dissection of axon guidance and target recognition 4 , 5 .
the pattern of r - cell - to - brain connectivity in the fly visual system is relatively simple and can be easily visualized .
a large collection of sophisticated molecular and genetic tools are available for detailed phenotype analysis of genes that encode for signaling proteins expressed in r - cell growth cones .
furthermore , the powerful fly genetics and the recent completion of the genome project greatly facilitate the identification and characterization of genes in drosophila .
the drosophila adult visual system is comprised of the compound eye and the optic lobe .
each ommatidium contains eight different photoreceptor neurons ( r cells ) , which are numbered r1-r8 .
r cells are born at third - instar larval stage , when precursor cells in the eye - imaginal disc begin to differentiate into r cells 6 . within each ommatidium
the pioneer r8 axon migrates toward the posterior edge of an eye - imaginal disc , where it converges with axons from other ommatidia and subsequently enters the optic stalk , a structure that connects the eye disc and the brain ( fig .
after exiting the optic stalk , the r8 axon migrates over the superficial layer of the optic lobe , the lamina , and subsequently terminates in the deeper medulla layer . within each ommatidium ,
the axons projected from later born r1-r7 cells form a single fascicle with the pioneer r8 axon , and thus follow the route of the r8 axon until reaching a region in between two layers of lamina glial cells ( i.e. epithelial and marginal glia ) . here
r1-r7 axons have to make a decision , whether to stop within the lamina or to migrate further into the medulla . in response to a stop signal from lamina glial cells 7 , r1-r6 axons terminate in the lamina ( fig . 1a ) . during pupation ,
r1-r6 growth cones undergo further stereotyped rearrangements and establish synaptic connections with lamina cartridge neurons 8 , 9 .
in contrast , r7 growth cones extend further into the medulla and terminate within a layer ( i.e. m7 ) that is deeper than the r8 terminal field ( i.e. m3 ) ( fig.1a ) .
the dreadlocks ( dock ) gene was originally identified by garrity and rao in the zipursky group in a forward genetic screen for mutations that disrupted r - cell axonal projection pattern but not affected r - cell differentiation and cell fate determination 10 . while loss of dock did not affect r - cell growth - cone motility , it caused abnormal axonal fasciculation , altered local retinotopic array , abnormal completed wiring pattern in the medulla , dramatic reduction in the size of r - cell growth cones , and the mistargeting of r1-r6 growth cones into the medulla layer ( fig .
the dock gene encodes for a sh2/sh3 adapter protein consisting exclusively of three n - terminal src homology 3 ( sh3 ) domains and a single c - terminal src homology 2 ( sh2 ) domain 10 .
unlike drk , another well - known sh2/sh3 adapter protein in drosophila that links the receptor tyrosine kinase ( rtk ) signaling to the classical ras pathway in regulating dna synthesis and gene expression 11 , 12 , however , dock is not required for r - cell differentiation and fate determination determination 10 .
indeed , expression of a human nck transgene in r cells almost fully rescued the dock phenotype 14 , suggesting strongly that nck is the functional homolog of dock in vertebrates .
the structure of the dock protein and the specific axonal projection phenotype support a model in which nck / dock links the guidance and targeting signals from growth - cone receptors to the actin cytoskeleton . by analogy with the action of drk
, it was proposed that dock mediates growth - cone signaling by binding simultaneously to activated growth - cone receptors and downstream effector proteins 10 .
indeed , biochemical studies on nck demonstrated that nck binds via its sh2 domain to specific phosphotyrosine - containing motifs on activated cell surface receptors and simultaneously binds via its sh3 domains to a number of target proteins carrying a conserved pxxp motif , the consensus sh3-binding site 15 .
interestingly , many of nck sh3-binding proteins , for instance , the ste20-like serine / threonine kinase pak ( p21-activated kinase ) and wiskott - aldrich syndrome protein ( wasp ) , have been implicated previously in regulating actin dynamics in cultured cells 16 , 17 , 18 , 19 . however , the biological function of nck as well as the in vivo relevance of the physical interactions between nck and its binding partners had not been determined at the time when the dock gene was identified .
the identification of dock thus not only serves as an excellent starting point for dissecting the mechanism of r - cell axon guidance and target recognition , but also provides a great opportunity for understanding the signaling mechanisms by which cell surface receptors communicate with the actin cytoskeleton in general . as the first step towards understanding the dock signaling pathway in r - cell growth cones , rao and zipursky performed mutagenesis analysis to determine the domain requirements for the function of dock 14 .
single point mutation was introduced into the sh2 domain and each sh3 domain to inactivate the binding capacity .
these mutant constructs were introduced into flies by germ - line transformation to generate mutant transgenic lines , which were then tested for their ability to rescue the dock null mutant phenotype .
surprisingly , it was found that the sh2 domain is not essential for rescuing the defects in r - cell guidance and growth - cone morphology , which appears to be due to the redundancy between the sh2 domain and two sh3 domains ( i.e. sh3 - 1 and sh3 - 3 ) 14 .
this is in marked contrast to the action of drk and its homolog grb2 in mammals and sem-5 in c - elegans .
the sh2 domain of drk / grb2/sem-5 binds to tyrosine - phosphorylated receptor tyrosine kinases and is indispensable for the function of drk / grb2/sem-5 in cell differentiation and proliferation 20 .
interestingly , while the sh2 domain is redundant with the sh3 domains for r - cell axon guidance and growth - cone expansion , it is essential for the establishment of neuronal connectivity in the inner optic lobe ( i.e. lobula and lobula plate ) 14 .
it also appears likely that this functional redundancy between sh2 and sh3 domains does not exist for the role of dock in regulating the lamina - specific targeting of r1-r6 axons ( see below ) .
these data argue strongly that dock utilizes different combinations of domains in mediating distinct signaling events in different cellular processes or different cell types .
indeed , it has been shown that dock binds to different sets of cell surface receptors in different cell types 21 , 22 , 23 . in r cells
, dock appears to be required in at least two distinct signaling pathways , one for r - cell axon guidance and growth - cone expansion , and another for r1-r6 growth - cone targeting ( see below ) .
to understand the action of dock in r - cell growth cones , it is necessary to identify cell surface receptors that function upstream of dock , and intracellular effectors that are regulated by dock - linked signals during r - cell growth - cone guidance and target recognition . in drosophila , dock has been shown to physically associate with at least three cell surface receptors , including the fly homologs of human insulin receptor inr 23 , the down syndrome cell adhesion molecule ( dscam ) 21 and the repulsive guidance receptor roundabout ( robo ) 22 . while it has been shown that inr is the upstream receptor for dock in r - cell growth cones 23 , dscam and robo appear to regulate dock during the pathfinding of larval photoreceptor axons and the medline crossing of embryonic cns axons , respectively 21 , 22 .
the mammalian genome contains three inr genes , which have been shown to be required for the control of metabolic activity as well as learning and memory in the nervous system 24 , 25 , 26 , 27 , 28 .
fly possesses a single inr gene , which is involved in regulating cell growth , longevity and female fertility 29 , 30 , 31 . using the cytoplasmic domain of dinr as a bait in a yeast two - hybrid screen ,
dinr associates with dock in adult flies , and is highly expressed in r - cell axons and their growth cones .
dinr loss - of - function mutants displayed defects in r - cell axon guidance and growth - cone morphology that are almost identical to that in dock mutants 23 .
these defects appear not to be caused by a general defect in r - cell growth and differentiation .
chico , the drosophila insulin receptor substrate ( irs ) homolog functioning downstream of dinr in mediating cell - growth signaling 32 , is not required for r - cell axon guidance 23 .
the in vivo relevance of the physical interaction between dinr and dock is further supported by the observed genetic interaction between dinr and dock during r - cell axon guidance 23 .
interestingly , dinr appears to bind to both sh2 and sh3 domains of dock in a yeast two - hybrid assay 23 , which is consistent with the observed functional redundancy between sh2 and sh3 domains of dock for r - cell axon guidance 14 .
these observations thus build a compelling case for that dinr functions upstream of dock during r - cell axon guidance .
given the fact that inr is required for learning and memory in mammals , it is likely that a similar interaction between nck and inr also exists in the mammalian nervous system .
the search for downstream effectors of dock in r - cell growth cones benefits greatly from previous biochemical studies on its mammalian homolog nck , which led to the identification of more than twenty nck - binding proteins 15 . among them , the ste20-like serine / threonine kinase pak is particularly interesting . in cultured cells , it has been shown that nck recruits pak to the plasma membrane 33 .
subsequently , pak is activated through its association with gtp - bound active form of rho family small gtpases rac and cdc42 34 , key regulators of the actin cytoskeleton 35 .
pak binds to the 2 sh3 domain of nck , which in dock is essential for r - cell axon guidance . in mammals
the polypeptide of the group i ( i.e. paks 1 - 3 ) pak carries a n - terminal pxxp motif for binding to nck , a crib motif ( cdc42/rac interactive binding ) for binding to small gtpases rac and cdc42 , and a c - terminal serine / threonine kinase domain .
three pak - related genes are found in the fly genome , including pak 37 , mbt ( mushroom bodies tiny ) 38 and pak3 . among them , pak is most closely related to the vertebrate group i pak and also contains the consensus n - terminal pxxp motif responsible for binding to nck .
indeed , zipursky and colleagues demonstrated a direct association of pak with dock 39 . to determine
if pak and dock functions in the same pathway in vivo , they took a reverse genetic approach to examine the role of pak during r - cell growth - cone guidance 39 .
indeed , they found that mutations in the pak gene locus caused severe defects in r - cell axon guidance and growth - cone expansion that are almost indistinguishable from that in dock mutants .
the function of pak in r - cell growth cones requires the kinase domain , the dock - binding pxxp motif , and the crib domain for binding to gtp - bound rac and cdc42 39 .
that expression of a membrane - tethered version of pak substantially rescued the defects in r - cell axon guidance and growth - cone expansion in dock null mutants 39 , suggesting strongly that the action of dock in r - cell axon guidance is to target pak to the plasma membrane . once reaching the plasma membrane , like the situation of the vertebrate pak 34 , 40 , the fly pak
may then be activated by gtp - bound rac and cdc42 to regulate the remodeling of the actin cytoskeleton within r - cell growth cones . in vertebrates , gtp - bound active form of rac and cdc42 can both bind to pak and stimulate its kinase activity 40 .
interestingly , later studies demonstrated that rac but not cdc42 is the major activator of pak in r - cell growth cones 41 , 42 .
the fly genome contains three rac - related sequences , including rac1 , rac2 and mtl ( mig - two - like ) , which appear to have largely overlapping function during development .
while loss of all three rac genes caused a dock- and pak - like r - cell growth - cone guidance phenotype 42 , mutations in cdc42 appeared to mainly affect r - cell differentiation and cell survival 43 .
consistent with that rac is the major activator of pak in r - cell growth cones , mutations in the trio gene encoding for a guanine nucleotide exchange factor promoting gtp / gdp exchange on rac but not cdc42 , also caused a pak - like r - cell axon guidance phenotype 41 .
a role for trio in r - cell axon guidance was firstly demonstrated by dickson and colleagues , who performed an elegant and simple eye - specific genetic screen to search for genes that are required autonomously during r - cell growth - cone guidance 44 .
the fly trio protein contains a n - terminal conserved domain , six spectrin repeats , two gef domains and a sh3 domain , all of which are also present in its homolog trio in vertebrates and unc-73 in c - elegans 45 , 46 , 47 . unlike the vertebrate trio 45 , however
, the fly trio does not contain the domain for binding to lar , a receptor tyrosine phosphatase 48 .
the action of trio for promoting gtp / gdp exchange on small gtpases is dependent on its gef domains consisting of a dbl homology ( dh ) domain and a pleckstrin homology ( ph ) domain , which are folded together to form a pocket for small gtpases .
interestingly , only gef 1 , which promotes gtp / gdp exchange on rac but not cdc42 and rho , is essential for r - cell growth - cone guidance 41 . reducing the dosage of trio enhanced a weak dock loss - of - function phenotype , while reducing the dosage of pak enhanced a weak trio phenotype 41 .
moreover , a trio gain - of - function eye phenotype could be fully suppressed by loss of three rac genes 42 .
these studies suggest strongly that trio functions upstream of rac and pak during r - cell axon guidance .
thus , the combination of above biochemical and genetic studies supports a model in which pak is activated sequentially by two signals ( fig .
, the activation of inr by one signal leads to the targeting of the dock - pak complex to the plasma membrane .
subsequently , the activation of trio by another signal leads to an increase in the local concentration of gtp - bound rac , which stimulates the activity of the membrane - associated pak , thus allowing pak to regulate actin dynamics during r - cell growth - cone guidance .
first , the ligand that binds and activates dinr during r - cell axon guidance is unknown . in drosophila ,
it will be of interest to determine if any of them acts as a guidance cue for inr in the fly visual system .
if not , it will be necessary to search for other ligands that activate inr during r - cell axon guidance .
although the fly trio does not contain the binding site for lar , it does interact with lar genetically during motor axon guidance in embryos 50 as well as the targeting of r7 axons in the visual system 51 .
it is possible that trio is also activated by a lar - like receptor during r - cell axon guidance .
third , the mechanism by which pak regulates actin dynamics in r - cell growth cones is unknown .
it has been shown that the vertebrate pak phosphorylates a number of cytoskeletal regulators , for instance , myosin light chain kinase and lim kinase 36 .
it would be of interest to determine if their fly homologs are also the substrates of pak in r - cell growth cones .
loss of dock not only caused defects in r - cell axon guidance and growth - cone expansion , it also disrupted r1-r6 growth - cone targeting 10 . in dock mutants ,
many r1-r6 axons bypassed the lamina , their appropriate target layer , and extended into the medulla instead ( fig . 1b ) . by contrast
these observations suggest the presence of additional signaling proteins that interact with dock during r1-r6 growth - cone targeting .
biochemical studies on nck show that in addition to pak , nck also binds to another ste20-like serine / threonine kinase nik ( nck - interacting kinase ) in cultured cells 52 .
nik belongs to the gck subfamily of ste20-like serine / threonine kinases 53 , 54 , and has a homolog misshapen ( msn ) in drosophila 55 and mig-15 in c. elegans 56 , both have been shown to be required for cell shape changes during development . like other gck subfamily members , nik
/ msn / mig-15 is comprised of an n - terminal kinase domain , and a c - terminal regulatory region containing binding sites for nck but not for small gtpases . by taking a combination of biochemical and genetic approaches , we demonstrate that msn functions downstream of dock to regulate r1-r6 growth - cone targeting 57 .
dock binds via its first and second sh3 domains to the proline - rich sequence on msn 57 , 58 .
loss of msn , like loss of dock , caused many r1-r6 growth cones to project aberrantly through the lamina into the medulla 57 .
conversely , overexpression of msn led to premature growth - cone termination before they reached their normal lamina termination site .
in addition to its physical association with dock , msn also interacts genetically with dock during r - cell projections 57 .
these data suggest strongly that dock - mediated r1-r6 targeting requires the activation of msn , which may phosphorylate one or more cytoskeletal regulators leading to the lamina - specific termination of r1-r6 growth cones . in a search for the suppressors of a premature growth - cone termination phenotype induced by overexpression of msn , we identified bifocal ( bif ) , a putative cytoskeletal regulator 59 , as a downstream target of msn in r - cell growth cones 60 .
this observation , together with that bif co - localizes with f - actin during development , led to the suggestion that bif is a cytoskeletal regulator 59 .
the potential role for bif in r - cell growth cones was examined by genetic analysis 60 .
interestingly , like loss of dock and msn , mutations in bif also caused many r1-r6 growth cones to project aberrantly into the medulla . like overexpression of msn , overexpression of bif also induced early growth - cone termination .
although it is unclear if bif binds directly to f - actin , it promotes f - actin formation and co - localizes with f - actin in cultured cells .
the effect of bif on the actin cytoskeleton in cultured cells could be modulated significantly in the presence of msn 60 .
these studies support a model in which a dock - linked targeting signal activates msn , which phosphorylates bif .
bif , in turn , directly or indirectly modulates the actin - cytoskeleton within r - cell growth cones leading to the termination of r1-r6 growth cones within the lamina ( fig .
the molecular nature of the stop signal and the upstream receptor for dock during r1-r6 growth - cone targeting remains elusive .
dinr has been shown to function upstream of dock during r - cell axon guidance and growth - cone expansion ( see above ) .
it would be of interest to determine if dinr also interacts with dock in specifying r1-r6 targeting .
since lamina glial cells appear to be essential for r1-r6 growth - cone targeting 7 , future genetic analysis of genes required in lamina glial cells for r1-r6 termination may help to identify the glial - derived protein that functions as a stop signal for r1-r6 growth cones in the lamina .
in addition to its interaction with pak , msn and trio , dock also displays genetic interaction with kette in r - cell growth cones 61 .
the kette gene encodes for a member of the evolutionarily conserved nap-1/hem2/gex3 family proteins 61 , 62 .
although it is unclear if dock and kette physically interact with each other in r - cell growth cones , their mammalian homologs nck and nap-1(nck - interacting protein 1 ) do form an in vivo complex 63 .
the association between nck and nap-1 is indirect and appears to be mediated by pir / sra1 ( specifically rac associated protein 1 ) , which may bind directly to the 1 sh3 domain of nck 64 , 65 .
nap-1/kette and pir / sra1 are present in a large protein complex also comprising of abi ( abelson - interactor ) 66 , 67 , scar / wave1 68 , 69 , and hspc300 70 .
biochemical studies show that the formation of this large complex prevents scar / wave1 from activating the arp2/3 complex that initiates actin nucleation 70 . consistently ,
genetic analysis in drosophila demonstrates that reducing the dosage of scar largely suppresses the kette axon guidance phenotype in the fly embryo 71 .
in addition to its inhibitory effect on the activity of scar / wave1 , nap1/kette is also required for the stability of scar / wave1 72 , 73 . in drosophila cultured cells , reducing the expression of kette with rnai treatment led to the degradation of the scar protein .
interestingly , it has been shown that the binding of nck to pir / sra1 and nap-1/kette can release scar / wave1 from the inhibitory complex , leading to the activation of the arp2/3 complex 70 .
similarly , dock may interact with pir / sra1 and nap1/kette in r - cell growth cones to regulate the activity of scar , thus providing an additional mechanism for dock to regulate actin dynamics during r - cell growth - cone guidance ( fig .
2 ) . future studies will be necessary to examine the exact role of kette in r - cell growth cones , and determine the potential cross - talk between the kette pathway and other dock - linked pathways .
a decade ago , biochemical and genetic studies of the well - known sh2/sh3 adapter protein grb2/drk / sem-5 greatly advanced our knowledge of the signaling mechanisms by which the signals are conveyed from cell surface receptors to the nuclei in regulating dna synthesis and gene expression during cell growth and differentiation 20 .
similarly , recent studies on the signaling of the nck / dock sh2/sh3 adapter in r - cell growth cones have shed light on the molecular mechanism of another equally important cellular process , the communication between cell surface receptor and the actin cytoskeleton . over the past eight years after the implication of dock in r - cell axon guidance and target recognition , significant progress has been made in defining the signaling pathways by which nck / dock links growth - cone receptors to the actin cytoskeleton .
these studies have led to the identification of several key players in the pathways , most of which are evolutionarily conserved .
for instance , mutations in the brain - specific pak isoform pak3 cause nonsyndromic x - linked mental retardation in humans 74 , which may be due to an early axon guidance defect during development .
the mammalian inr has also been implicated in learning and memory 25 , 26 , 27 , 28 , which may reflect a role for inr in the wiring of neural network in mammals .
thus , in addition to continuously fill the gaps in the nck / dock signaling pathways for r - cell axon guidance and target recognition in drosophila , a major challenge for the future is to define the role of nck / dock and its interacting proteins in the establishment of neuronal connectivity in mammals .
( a ) in the wild - type fly visual system , r - cell axons form a highly organized projection pattern in the optic lobe .
r1-r6 axons terminate in the lamina , while r7 and r8 axons project through the lamina into the medulla .
r - cell growth cones expand significantly in size after reaching their appropriate target layer .
( b ) in dock mutants , r - cell axons form abnormal large bundles in both lamina and medulla .
some axons bypass the medulla . many r1-r6 axons project aberrantly through the lamina into the medulla .
models for the action of the nck / dock signaling pathways in r - cell growth cones . during r - cell axon guidance and growth - cone expansion ,
pak is activated by the combined action of an inr - dock - linked signal and a trio - rac - linked signal , thus allowing pak to modulate cytoskeletal changes .
dock may also link the guidance signal to the actin cytoskeleton via the sra-1-kette - scar pathway . during r1-r6 targeting , a dock - linked stop signal activates msn , which in turn phosphorylates bif . | ### Summary:
: the establishment of neuronal connections during embryonic development requires the precise guidance and targeting of the neuronal growth cone , an expanded cellular structure at the leading tip of a growing axon .
the growth cone contains sophisticated signaling systems that allow the rapid communication between guidance receptors and the actin cytoskeleton in generating directed motility .
previous studies demonstrated a specific role for the nck / dock sh2/sh3 adapter protein in photoreceptor ( r cell ) axon guidance and target recognition in the drosophila visual system , suggesting strongly that nck / dock is one of the long - sought missing links between cell surface receptors and the actin cytoskeleton . in this review ,
i discuss the recent progress on dissecting the nck / dock signaling pathways in r - cell growth cones .
these studies have identified additional key components of the nck / dock signaling pathways for linking the receptor signaling to the remodeling of the actin cytoskeleton in controlling growth - cone motility . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: cancer is the second leading cause of death in most developed countries today .
the projected number of new cases by the year 2015 is 5 million for the developed countries and 10 million for the developing countries , while the number of deaths estimated will be 3 and 6 million , respectively . in india ,
the state of uttar pradesh ( u.p . ) has a population of 150 million , and it was estimated that annual new cancer patient load , would be around 100,000 to 120,000 by the year 2010 . to cater to this load
approximately 200 radiation oncologists are required as compared to only 50 existing in the state at any given time .
international atomic energy agency ( iaea ) has suggested the desirable requirement for radiation oncologists as one per 200250 cancer patients .
1215 medical graduates ( mbbs ) enroll for the postgraduate training program in radiotherapy ( md radiotherapy ) in the state of u.p . per year , and not all the radiotherapy departments are fully equipped with the basic radiotherapy facilities and faculty for effective teaching and training . to cater to the increasing load of cancer patients , creation of adequate and skilled manpower to run oncology centers effectively is the need of the hour .
training in radiation oncology requires teaching and training in radiation physics , radiobiology , clinical oncology for which resources are lacking .
the basic radiation treatment facilities exist in a limited number of medical colleges , and a few private cancer centers in the state , whereas advanced facilities exist only in our department , being a part of a tertiary level medical institute and a regional cancer centre . in order to fulfill the ever increasing demand of competent radiation oncologists
, telemedicine can be utilized to disseminate knowledge and skills to less privileged centers to complement their existing system .
olsen et al . has discussed the requirements and applications of telemedicine in radiotherapy treatment planning .
level 1 features video conferencing for consultation and display of radiotherapy images and dose plans .
level 2 involves replication of selected data from the radiotherapy database facilitating remote treatment planning and evaluation .
level 3 includes real - time , remote operations , for example , target volume delineation and treatment planning performed by the team at the satellite unit under supervision and guidance from more experienced colleagues at the main clinic .
they have shared their experience with national telesynergy network for oncology services in ireland which was established with a aim to improve service delivery and efficiency , reduce patient travel , and support earlier diagnosis .
keishiro suzuki has demostrated the development of a web - based , remote radiation treatment planning system which allowed staff at an affiliated hospital to obtain support from a fully staffed central institution . in a study by maguire et al .
they have demonstrated that complex radiation treatment planning review was feasible between an academic and community hospital via telesynergy network with a high level of physician satisfaction .
though use of telemedicine for distance education is common , it has not been reported in the field of radiation oncology . in the xith national cancer control program of ministry of health and family welfare , government of india ,
the experts have recommended closure of md radiotherapy programs at ill equipped centers . with a view to facilitate teaching , training , and
carry - out collaborative clinical and translational research of the common cancers seen in the state of u.p . , we embarked upon a project to establish telemedicine link with other departments of radiotherapy of the teaching medical institutions in the u.p . having limited resources in a phased manner .
ours is a tertiary level teaching hospital with a fairly well equipped radiation oncology department in the context of a developing country .
the objective of the first phase of this project was to establish links with the chhatrpati shahuji maharaj medical university ( csmmu ) within the city located 25 km away from our institute and evaluate its benefit before embarking on expansion to other locations .
in 2003 , a presentation was made by our department to the department of science and technology ( govt . of india ) , regarding the healthcare needs pertaining to oncology in the state of uttar pradesh .
the members were apprised of the usefulness of telemedicine as a tool to disseminate knowledge and skills to various teaching hospitals of the state to produce competent specialists , for teleconsultation , for telefollowup of cancer patients leading to possible benefits for the health delivery system for the citizens of the state .
a grant of 75 lakh indian rupees ( approximately 1.6 lakh usd ) was granted for this project towards cost of hardware and software including intradepartmental network .
it was recommended that for phase i of this project , successful telelinks between departments of radiotherapy of sgpgims and csmmu should be first established before establishing tele - links with medical colleges in other cities of the state .
the department of radiotherapy of the csmmu was chosen as the remote center for telelink up in the first phase of this project . with the help of the school of telemedicine of our institute
the concept was translated to designing and developing an exclusive telemedicine network for specific application for radiotherapy .
the technical part of the project was implemented through technical partner , online telemedicine research institute , ahmedabad ( otri ) and the network architecture , hardware and software for the telemedicine platform were worked out .
polycom ( model : vsx 5000 ) pal camera - based video conferencing equipment and 42 plasma monitor with a screen resolution of 1024 768 for display was installed at both the nodes .
the software used to establish the video - conferencing connectivity is people + content ip supplied by polycom . an integrated services digital network ( isdn )
telecommunication media ( 128 kbps ) with static ip was chosen for the network .
the telemedicine platform so created at both the nodes is shown in figure 1 .
the project implementation team inspected the physical infrastructure at the remote center to ensure suitable environment for installation of the telemedicine platform .
room dimension , power situation , and acoustics were the few factors important for deciding site suitability .
project manpower appointed were 2 telemedicine technicians , one for host node and other for remote node .
other technical manpower support was provided by the school of telemedicine of our institute as per the requirements from time to time . site preparation and installation of equipments at both nodes
were completed along with integration of isdn telecommunication media in the month of february 2007 .
after the technical testing of telecommunication with isdn lines , functional modules of telemedicine were tested and demonstrated to department faculty and trainee residents at the host and remote node .
one week on - site training was provided to the telemedicine technicians which continued later with demonstration sessions .
all above mentioned training and demonstrations were given by engineers and application specialists from project technical partner otri . from april 2007
the academic sessions for post graduate students conducted in the host department were shared in real time interactive videoconference mode with the remote participants being trainee residents and interested faculty .
a total number of 201 academic sessions were planned to be transmitted in two years .
these sessions consisted of lectures on clinical oncology , medical physics , and radiobiology delivered by either trainee residents or hospital services residents , medical physicists or clinical faculty as a part of the academic roster of the department .
any questions at the end of the sessions were attended by the presenter and the faculty from the host end .
this network was also used for teleconsultations , live telecast of the proceedings of the national conference of radiation oncologists , and shared lectures of national as well as international guest speakers visiting the host department .
due to narrow bandwidth of isdn network image , quality of image transmitted was poor , and there was significant time lag between audio and display signals .
subsequently , after one and a half years , the network was shifted from 128 kbps isdn to 2 mbps leased optic fiber circuit with a view to expand the activities and correct the above problems .
all the events taking place between the two telemedicine nodes were recorded in the log book maintained on day - to - day basis .
later , the data was entered into the prescribed proforma devised for the evaluation of the activities . periodic audit report at the end of each year was submitted to the funding agency . final evaluation of the project was carried out by compiling the data of the activities of year 2008 - 2009 .
a feedback from the users at the remote end after each session was collected in the last 6 months of the audit regarding the content of the program and the quality of the videoconferencing .
this was obtained on a questionnaire and the feedback received was recorded on an excel sheet .
there were 4 questions in the questionnaire pertaining to the ( a ) quality of content of the topic discussed , ( b ) utility of the topic chosen for the purpose of md trainee , ( c ) efficacy of the instructor to communicate , and ( d ) the quality of videoconferencing .
every attendee filled the feedback form and the responses were rated on a scale of 010 .
the data was then analyzed for the percentage of participant 's response obtained for score more than 7 .
a score of more than 7 was chosen for evaluation since it reflects a better than average score on a qualitative score of 1 to 10 .
for the purpose of reporting , a feedback was later also obtained from the trainees whether they preferred in person lectures or videoconferencing .
the results are based on an analysis of the events recorded in the log book and feedback received from participants ( table 1 ) . from april 2007 to may 2009 , regular videoconferencing sessions were conducted .
a total number of 201 sessions were planned to be transmitted in two years and amongst this a total of 119 sessions could be transmitted .
the rest had to be cancelled for either technical reasons ( 20% ) or nonavailability of the presenter at the host end ( 80% ) .
6 to 8 participants ( trainee residents and in - charge faculty at the remote end and 16 to 20 participants ( all trainee residents , hospital services residents , and faculty and medical physicists ) at host end ) attended the sessions regularly .
the technical problems for cancellation of sessions were isdn connectivity problems , videoconferencing equipment functionality , and disruption of power supply .
since the remote end itself is a medical university teleconsultation activities were very few and subsequently , the need for teleconsultation was not felt .
after initiation of the project , feedback from the remote end revealed that the image quality was poor and there was a significant time lag between audio and video signals .
audio input was optimal to understand the intermittent discussions at the host end during the sessions , but had scope for improvement .
subsequently after one and a half years , the network was shifted from 128 kbps isdn to 2 mbps leased optic fiber circuit .
feedback of questionnaire revealed that the quality of content of the topics discussed was good ( score assigned more than 7 by 76% users ) , topics chosen were relevant for the md trainee ( score assigned more than 7 by 77% users ) , presenters effectively communicated their presentation ( score assigned more than 7 by 70% users ) , and the quality of videoconferencing was given a score of more than 7 by 60% users .
the trainees were of the opinion that the topics covered were relevant and well discussed from the md examination point of view .
an average of 3 questions per session were received and attended by the presenter or faculty at the host end to satisfy the queries at the remote end .
most of the trainees at the remote end preferred in - person lectures to videoconferencing because of time lag and occasional disconnection of the transmission .
telemedicine applications in radiation oncology are multiple which ranges from tele - education to assistance in simulation , radiation treatment planning , and dose calculation [ 49 ] .
distance education in radiation oncology is an important modality of knowledge sharing for creation of manpower trained to deliver appropriate treatment to cancer patients . unlike many other fields of medicine ,
radiation oncology is a dynamically changing , high - technology field , and successful practitioners for the future need to evaluate and adapt to changing patterns of practice .
exposure of residents to available technology , its principles , usage , and outcomes is essential for enhancements of their theoretical knowledge . though telemedicine for distance education is not a new concept its implementation in a radiation oncology setup in a developing country
the entire process of developing a telemedicine project such as concept , design , development , implementation , administration , and evaluation have been addressed in great detail to make the reader understand the practical issues while deploying such a project .
telemedicine fulfilled its expectations of delivering quality education to the trainee residents for their md exams and fill the gap in of scarcity of teachers to train the residents .
the method of assessment used by us to evaluate the benefit due to telemedicine still has scope for improvement .
also , we have now taken measures to ensure strict discipline on behalf of presenters at the host end to minimize human factors as cause of cancellation of the proposed academic sessions .
this project has created awareness amongst teachers and trainees in other medical colleges in the state about the benefit of teleeducation and its success is evident from the fact that they are keen to establish telelinkage with our center .
further , we also intend to extend this facility for other applications of telemedicine in radiotherapy as discussed earlier .
distance education in radiation oncology is an important tool for training of the trainee residents . we were able to facilitate teaching and training of residents at the remote center as envisaged though cancellation of sessions should be minimized .
two years of experience has taught us lessons to be able to handle the technical challenges to further expand our network to other centers in the state . | ### Summary:
: purpose . the estimated
new cancer patient load in the indian state of uttar pradesh is 0.10.12 million per year .
approximately two thirds of these require treatment by a radiation oncologist .
radiation oncologists : cancer patient ratio in this state is 1 : 2000 as compared to the recommended 1 : 250 .
this problem is compounded by the poor infrastructure of radiation oncology departments in the state which is suboptimal for teaching , training of resident doctors , and treatment in most barring a few departments . to bridge some gap in the sociodemographics
stated above and enhancement of training of residents , we submitted a project for establishment of a telemedicine facility in our department to the department of science and technology , government of india .
we present the design , implementation , and a two - year audit of our tele - education activities .
materials and methods . after the sanction of the project , we established telemedicine linkage with another medical institute in the city located 25 kms away in 2007 .
after implementation of the project , academic sessions designed for trainee residents in our department were shared with the remote end .
a record of these activities and a feedback of the activities were audited at the end of 2 years of implementation of this project .
results .
regular videoconferencing sessions comprising of lectures on clinical oncology , medical physics , and radiobiology were held .
feedback from the users revealed satisfaction with the content of the academic sessions for the purpose of md training .
conclusions .
distance education in radiation oncology is an important tool for training of the trainee residents . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: 1,2 it reduces the serum uric acid levels by inhibiting the xanthine oxidase enzymes , which is responsible for the synthesis of uric acid.3 in addition to gout and hyperuricemia , it has been utilized for prevention of tumor lysis syndrome4 and renal stones diseases ( urate stones and recurrent calcium oxalate stones associated with urinary uric acid excretion more than 800 mg / day).5 despite this clinical utility , severe hypersensitivity reactions may occur with allopurinol , which although less common , is associated with significant morbidity and mortality.6 hence , appropriate dose regimen is imperative in the prevention of this fatal outcome .
a number of factors have been discovered to demonstrate the appropriate usage of this drug in clinical practice in order to prevent potential adverse outcomes .
hande et al7 first demonstrated the relationship between allopurinol dose and pre - existing renal impairment in the development of hypersensitivity syndrome and suggested guidelines for the adequate dose based on creatinine clearance .
stamp and colleagues8 emphasized the significance of creatinine clearance in the prediction of the adequate dose of allopurinol .
for the purpose of this study appropriate dose calculation of the drug was based on validated quality indicators developed to assess the quality of allopurinol prescribing practices.9,10 apart from creatinine clearance estimation , physician s specialty is also a contributing factor in inadequate prescription of allopurinol .
athisakul et al11 highlighted the role of different physicians in determination of indication and prescribed dosage in a large tertiary care hospital .
they observed both poor adherence to the current dosing guidelines for allopurinol according to creatinine clearance and prescription of this drug in various inappropriate indications by doctors from different specialties . in spite of these causative factors , the prescribed doses of allopurinol in clinical practice by
medical practitioners still diverge from the approved guidelines.12 this necessitates the further exploration of these contributory factors in order to establish the improper usage of this commonly prescribed medicine in clinical practice .
therefore , this study aimed to determine the appropriateness ( both in terms of indications and adequate dosage regimen via creatinine clearance estimation ) of utilizing allopurinol by doctors of different specialties in a tertiary care centre .
computerized clinical records of all adult patients , who were prescribed allopurinol , visiting outpatient clinic from 12th november to 11th december 2011 were retrieved .
a proforma was designed to document findings which included patient s demographics ( name , age and gender ) , serum uric acid levels ( in millimole / l ) , comorbidities ( diabetes , hypertension , chronic liver disease , cerebrovascular accidents , osteo- and rheumatoid arthritis , ischemic heart disease , hypothyroidism , and polycythemia vera ) , indications of allopurinol usage ( gout , uric acid and recurrent calcium oxalates stones , tumor lysis syndrome , hyperuricemia , and hyperurocosuria ) , prescribing doctor s specialty , and dosage of allopurinol .
the prescribed dosages were categorized into correct and incorrect dose adjustments based on validated quality indicators developed to assess the quality of allopurinol prescribing practices.9,10 for the purpose of this study following two quality indicators were used : if a gout patient is receiving an initial prescription for allopurinol and has significant renal impairment ( defined as a serum creatinine 2 mg / dl or measured / estimated creatinine clearance 50 ml / min ) then the initial daily allopurinol dose should be less than 300 mg per day because the risk of allopurinol - related toxicity is increased in the presence of significant renal impairment in gout patients given a daily allopurinol dose equal to or exceeding 300 mg . and
if a patient has asymptomatic hyperuricaemia characterized by ( 1 ) no prior history of gouty arthritis or tophaceous deposits and ( 2 ) no prior history of nephrolithiasis or hyperuricosuria and ( 3 ) no ongoing treatment of malignancy then urate - lowering therapies should not be initiated because there is currently no widely accepted indication for the treatment of asymptomatic hyperuricaemia.9,10 the creatinine clearance was calculated using cockcroft - gault equation.13 all statistical analyses were performed using statistical package spss for windows program ( version 16 , spss inc , chicago , il , usa ) .
allopurinol was prescribed to 156 patients during the study period with mean ( sd ) age of 58.15 ( 14.99 ) years .
there were 105 ( 67.3% ) males and 51 ( 32.7% ) females with male to female ratio being 2:1 .
the mean ( sd ) serum uric acid levels of study participants were 0.43 ( 0.12 )
allopurinol was administered at a dosage of 100 mg / day , 150 mg / day , 200 mg / day and 300 mg / day to 88 ( 56.4% ) , 01 ( 0.6% ) , 03 ( 1.9% ) and 64 ( 41% ) patients , respectively .
table 2 demonstrates the details of the physicians who prescribed allopurinol , indications and dose adjustment according to creatinine clearance of the patients .
allopurinol was most commonly prescribed by nephrologists followed by family physicians in this study . out of 156 patients ,
allopurinol was given with appropriate indications in 46 ( 29.5% ) patients . among them , gout was the most frequent indication followed by uric acid stones ( fig .
none of the patients in this study received allopurinol for recurrent calcium oxalate stones and hyperuricosuria .
this indication of hyperuricosuria is important as not a single physician order for uric acid excretion in our review .
we do not know the exact cause however this was probably related to poor adherence to guidelines or poor knowledge .
eighty - five ( 54.5% ) patients in this study received allopurinol without dose adjustment for their creatinine clearance .
only twenty - one ( 13.5% ) of these patients received allopurinol with appropriate indications . among them , twelve patients received allopurinol prescribed by nephrologists .
furthermore , dose adjustment according to creatinine clearance was not carried out in 85 ( 54.5% ) patients ; among them , 21 ( 13.5% ) received allopurinol with appropriate indications .
allopurinol is the most commonly prescribed medication for the treatment of gout and hyperuricemia but has been assoicated with severe adverse reactions that can lead to death.14 a 10 years observational survey at the dermatology department of cagliari ( italy ) , allopurinol was the causative drug in 84 of 780 cases ( 10.7% ) of cutaneous adverse drug reaction.15 most of the allopurinol prescriptions were inappropriate without dose adjustment in this survey . hence
the current study also showed the administration of allopurinol in several non - indications ( 70.5% ) . in a review of 28 patients with hypersensitivity syndrome associated with allopurinol by lee
the current study also demonstrates appropriate indications in 29.5% of patients , which is nearly comparable to the lee et al study .
therefore , these literature reviews conclude that medical practitioners mostly prescribe allopurinol irrationally with no clear indications .
another important finding of this study is that physicians prescribe it for all patients with asymptomatic mildly elevated uric acid level .
the current recommendation for the treatment of asymptomatic hyperuricemia is that it should be treated if the level of uric acid is very high ( male : 713 micmol / l and female : 595 micromol / l).16,17 in the current study , the mean uric acid level was 430 ( 120 )
micmol / l ; which clearly point out the trend of treating uric acid at much lower level to the current recommendations .
hyperuricusuria can be treated if the uric acid excretion is > 1100 mg or 6,5 mmol / day ; failed to dietary restriction to lower it less than 1000 mg or 5.9 mmol / l.16,17 no single physician order for uric excretion in our review which probably related to poor adherence to guidelines or poor knowledge .
in addition to inappropriate indications , prescribed dosing guidelines based on creatinine clearance are also obligatory for the prevention of fatal adverse outcomes of the allopurinol , as previously mentioned by hande and associates in their case series.7 since then , a large body of literature has been published to emphasized this fact.8,11,18,19 the dose adjustment of allopurinol according to creatinine clearance prevents the severe toxicity associated with over dosage , as previously mentioned by perez - ruiz and co - workers.20 despite this , a wide diversity in allopurinol doses has been observed from the approved guidelines.12 in this study , eighty - five ( 54.5% ) patients received allopurinol without dose adjustment for their creatinine clearance .
athisakul et al11 in their study also demonstrated a significant number of patients who were received allopurinol without dose adjustment .
although improper indications and inadequate dose adjustment of allopurinol are considered to be fundamental factors in inappropriate prescriptions , consideration of physicians specialty also has pivotal role in this inappropriateness .
athisakul et al11 showed that internists prescribed this medicine with proper indications to majority of patients ( 70.8% ) in a tertiary care centre .
gout was the main indication of its usage in their study . out of this ,
the administration of allopurinol with both inappropriate indications and dose adjustment was given by family physicians , orthopedists , and other specialists in their study .
in the current study , gout was the main indication followed by uric acid stones for allopurinol therapy .
this is the main explanation of the major proportion of allopurinol prescriptions by nephrologists in this hospital .
another possible reason for the prescription of allopurinol by nephrologists is publication of new epidemiological data that claims that lowering uric acid level may decrease progression of renal failure and degree of hypertension.21 the family physicians in the current study were responsible for improper prescription of allopurinol in terms of adequate indications , which is nearly similar to the results of athisakul et al study.11 there are few limitations of this study .
firstly , the decline in serum uric acid levels with corrected dose adjustment of allopurinol was not evaluated by authors .
secondly , the side effects of allopurinol ( with or without dose adjustment ) were not delineated in this study .
the inappropriate use of allopurinol ( both the indication and prescribed dosage ) is still a major problem in a large tertiary care centre .
main reason of inappropriate prescription is use of allopurinol even to patient with asymptomatic mild hyperuricemia .
furthermore , the specialty of physicians is also a contributory factor in this inappropriate prescription . | ### Summary:
: objectiveto determine the appropriateness ( both indications and adequate dosage regimen via creatinine clearance estimation ) of allopurinol by physicians of different specialties in a tertiary care centre.patients and methodsin this cross sectional study computerized clinical records of 156 adult patients who were prescribed allopurinol from 12th november to 11th december , 2011 were retrieved from al hada hospital taif saudi arabia .
main outcome variables were approprsiate indications of allopurinol , prescribing physician s specialty , and dosage of allopurinol .
the prescribed dosages were categorized into correct and incorrect dose adjustments based on creatinine clearance estimation .
the spss version 16 was utilized for data analyses.resultsthe mean ( sd ) age was 58.15 ( 14.99 ) years .
there were 105 ( 67.3% ) males and 51 ( 32.7% ) females with male to female ratio being 2:1 .
allopurinol was frequently prescribed by nephrologists and family physicians in this study .
out of 156 patients , 46 ( 29.5% ) patients received allopurinol with appropriate indications .
eighty - five ( 54.5% ) patients were received allopurinol without dose adjustment based on their creatinine clearance estimation ; among them , 21 ( 13.5% ) received allopurinol with appropriate indications.conclusionthe inappropriate use of allopurinol ( both the indication and prescribed dosage ) is still a major problem in a large tertiary care centre .
furthermore , the specialty of physicians is also a contributory factor in this inappropriateness . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: idiopathic retroperitoneal fibrosis ( irf ) is a disease characterized by a fibrotic process at the retroperitioneal area and around the aorta .
the fibrotic plaque entraps and gradually obstructs retroperitoneal structures such as the ureter , inferior vena cava and aorta .
irf is believed to develop as a consequence of nonspecific inflammatory processes mediated by varying degrees of immune reaction .
elevated erythrocyte sedimentation rate ( esr ) , hypergammaglobulinema , autoimmune antibody , multiple vasculitis , pericardial or pleural effusion are frequently found in irf . some links between irf and renal disease , such as immune complex glomerulonephritis ( gn ) ,
we present a young male patient with minimal change nephrotic syndrome who subsequently developed irf 13 years later .
our irf case is also unique in that the disease manifested as a localized abdominal mass with few systemic symptoms .
a 30-year - old man was admitted with a mass in the right upper quadrant ( ruq ) of the abdomen .
nephrotic syndrome was diagnosed and prednisolone and diuretics were prescribed . even though his initial nephrotic syndrome had reached a complete remission
, his renal tissue showed no abnormal findings except slightly increased size in all 15 glomeruli ( fig .
trace amount of mesangial igm deposits were found on immunofluorescent microscopic examination and diffuse effacement of foot processes were noted by electron microscopy . under the impression of minimal change disease ,
the mass was not painful , but caused mild ruq discomfort while growing in size .
he denied any past history of abdominal trauma or surgery of having taken any medications such as herb , ergot derivatives , antihypertensives etc . on admission
his blood pressure was 110/70 mmhg , respiration rate was 20/min , and the body temperature was 36.5c . a hard , fixed , palm - sized mass was palpated at the ruq of the abdomen .
he had massive proteinuria ( 19.8g / day ) and a low serum albumin concentration ( 1.8g / dl ) .
. an elevated erythrocyte sedimentation rate ( 95mm / hr ) and c - reactive proteins ( 2 + ) were also noted .
computed tomography ( ct ) of the abdomen showed a huge 10cm - sized solid mass in front of and adjacent to the right kidney .
precontrast ct scan showed that the mass had heterogenous attenuation and fine calcification in it .
the post - contrast scan revealed that the mass was a mixture of solid portions with high attenuation and necrotic portions with low attenuation .
the right kidney was rotated upward on the frontal plane but the shape and the excretory function were normal ( fig .
he was subjected to an exploratory laparotomy for the definitive diagnosis of intra - abdominal mass . during laparotomy
, we observed a well - encapsulated whitish solid mass with the dimensions of 151119 cm below the right kidney in the retroperitoneal space .
the right kidney was pushed upward and rotated horizontally by the mass . in some part of the mass ,
no evidence of intra - abdominal lymph node enlargement or other organ abnormality was observed .
seen through the light micorscope , most part of the tissue had dense deposits of collagen fiber and fibroblast proliferation but , at the periphery of the mass , there were localized inflations of inflammatory cells such as lymphocytes , plasma cells and histiocytes , forming germinal centers ( fig .
he reached remission at the end of the 8th week , but the nephrotic syndrome relapsed one month after prednisolone tapered off .
cyclophosphamide was added and currently he is maintaining a complete remission status for 20 months .
retroperitoneal fibrosis is considered idiopathic in 70% of the cases , and the remaining 30% are attributed to various cause - medications ( ergot derivatives , beta - blockers , methyl dopa ) , malignancy , retroperitoneal infection , trauma and abdominal aortic aneurysm .
que et al reported a case of irf with raynaud s phenomenon , pulmonary fibrosis and anti - nuclear antibody in the serum and implied that irf is a local manifestation of systemic fibrosing processes .
lipman reported the case of a 29-year - old negro woman with nephrotic syndrome and other characteristic features of systemic lupus erythematosus who developed irf five years later .
kay described a case with retroperitoneal fibrosis and symptoms of arthralgia , stiffness and pericardial friction rub and changes of rheumatoid spondylitis at autopsy .
although not evidently seen in this presented patient , about 15% of irf cases are accompanied by fibrotic process in areas other than retroperitoneal space - i.e .
these fibrosing lesions share definite pathological similarities with one another . elevated erythrocyte sedimentation rate ( esr ) , hyperglobulinemia , autoimmune antibody ( anti - thyroid antibody , anti - nuclear antibody , positive coomb s test ) , multiple vasculitis , pericardial or pleural effusion , immune - complex mediated glomerulonephritis are frequently seen in irf , suggesting that irf is a kind of connective tissue disorder and is a local manifestation of systemic diseases of an immunologic etilolgy .
association of irf and renal disorder has been reported by a few authors . in a retrospective study , among 46 irf patients
13 patients ( 28.2% ) had albuminuria . two irf cases with clinically evident nephrotic syndrome
renal biopsy findings of lipman s patient were compatible with lupus nephritis in which focal proliferative lesions were intermingled with zones of fibrinoid necrosis .
littman s patient developed nephrotic syndrome 9 years after he was diagnosed to have irf , and later his disease proved to be a renal amyloidosis .
katz et al reported a 26-year - old female irf patient whose renal tissue showed capillary and mesangial deposits of igg and complements , which advocated a possibility of immune - complex mediated chronic glomerulonephritis in irf .
electron dense deposits in the glomerular basement membranes observed by zabetakis in a patients with crescentic gn and irf also supports the possibility of immune - complex mecdiated gn in irf . to our knowledge , no reports have been found about the association of minimal change nephrotic syndrome with irf .
the presence of cd4 + lymphocytes in irf and clinical efficacy of corticosteroids when given before the dense fibrotic stage , as well as a case reported by kirschbaum et al , who had irf and interstitial nephritis , support the possible role of cell mediated immunity in the pathogenesis of irf .
therefore , it remains to be solved whether , as seen in our patient , minimal change nephrotic syndrome is pathophysiologically related with or a casual finding of irf .
the second unique finding in this patient was that the presented patient had few systemic manifestations .
patients with retroperitoneal fibrosis usually have nonspecific symptoms - noncolicky back or abdominal pain , fatigue , weight loss and mild fever . the symptoms and signs of the disease
are closely associated with entrapment and mechanical compression of the ureter , inferior vena cava , aorta and its branches and gonadal arteries .
but , it casues flank pain and tenderness , costovertebral angle tenderness , oliguria or anuria and finally renal failure .
compression of the inferior vena cava can cause edema in both legs , the scrotum , and deep vein thrombophlebitis of the lower extremities .
eventually , compression of the aorta and common iliac arteries brings claudication and gangrenous change .
our patient did not have any of the symptoms mentioned above , partly becasue irf was localized to the ruq with minimal compressive effects on the retroperitoneal structures , and partly becasue the steroids that he had been taking masked systemic symptoms of irf .
irf sometimes occurs in areas where there is a severe atherosclerotic change and weakened media in the aortic wall .
this is explained by the hypothesis that insoluble lipid ( ceroid ) leaks from the aorta through the weakened wall and is phagocytized by macrophages , thus causing various immune responses and fibrosis in the end . but this hypothesis can not account for the irf in the children who do not have any atherosclerotic change in the aorta .
irf presented as a local mass , as in our case , is extremly rare .
his chief complaint for one year was a palpable nontender mass in the left upper quadrant of the abdomen .
the mass was localized and surrounded the left kidney , 2517 cm and well - demarcated .
other reports on localized forms of irf cases were given by judith and thomas g ( table 2 ) .
such localized forms of irf should be differentiated from renal cell carcinoma , renal cortical or medullary carcinoma , lymphosarcoma , ureter tumors , pancreatic cancer , rectal cancer and intrapelvic tumor or abscess .
ureterolysis involves dissecting the ureter from surrounding fibrotic plaque and wrapping it with peritoneum or omentum ( intraperitonealization ) in order to prevent it from re - fibrosis .
steroids are effective only at the early stage of the disease containing cellular infiltrates but does not help much in advanced fibrotic phases with scanty infiltrating cells .
( early stages are suggested by the findings of an elevated esr , eosinophilia , and lymphocytic rather than fibroblastic infiltration in the biopsied plaque . )
some authors reported that comcomitant long - term treatment with steroid and azathioprine induced loss of retroperitoneal mass and finally remission of hydonephrosis and lower leg edema .
alternative therapies involve uses of indwelling urinary stent , percutaneous nephrostomy and percutaneous balloon dilatation . | ### Summary:
: we present a 30-year - old male patient who was initially diagnosed as minimal change nephrotic syndrome .
5 years later , the patient developed a localized form of idiopathic retroperitoneal fibrosis ( irf ) .
an elevated esr and concomitant nephrotic syndrome in the patient suggested the immunologic nature of irf .
irf has been reported in association with collagen diseases and rarely with proliferative and nonproliferative glomerulopathies . to our knowledge ,
the association between minimal change lesion ( mc ) and irf has not been reported .
furthermore , the fact that irf presented itself as an abdominal mass and lacked systemic symptoms was also unusual . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: considering the etiological role of infections in several other chronic diseases , a relationship between infections and obesity is plausible .
adenovirus-36 ( ad-36 ) has been shown to cause obesity in chickens , mice , and nonhuman primates [ 3 , 4 ] .
it has been demonstrated that experimental and natural ad-36 infection of multiple animal species resulted in obesity through increasing proliferation and differentiation of preadipocytes and lipid accumulation in mature adipocytes [ 3 , 5 , 6 ] .
the data on association between ad-36 and obesity in adults differ between studies being somewhat inconsistent , but the findings in children consistently associate ad-36 infection with obesity .
a study shown that 30% of obese and 11% of nonobese humans have neutralizing antibodies to ad-36 , and the presence of antibodies was associated with reductions in serum cholesterol and triglycerides . in nondiabetic swedish individuals , it was shown that ad-36 infection is associated with pediatric obesity , severe obesity in adult females and lower risk of high blood lipid levels . in a population of children in the united states ,
the prevalence of antibodies to ad-36 was higher in obese children than in nonobese children . on average ,
antibody positivity was associated with 35-pound greater body weight . in a group of obese school children from south korea ,
30% had antibodies to ad-36 , and infected children had higher body mass index z - scores than uninfected children .
recent reports of adults in italy and children in south korea support the association of ad-36 and obesity , and show that ad-36 is more common in obese persons ; prevalence ranges from 29% to 65% [ 11 , 12 ] . in previous studies , the association of ad-36 seropositivity with obesity was established in adults and children , but in mexican population is unknown this relationship .
the current study evaluated the association of positive antibody to ad-36 with obesity and metabolic profile in a sample of mexican children .
this research presents cross - sectional data from serum and clinical data that were collected between september and december , 2008 . the sample included 75 normal - weight children and 82 obese children ( n = 157 , 6 to 11 years ) .
the children were recruited of three schools in the urban area from chilpancingo , state of guerrero , mexico .
informed written consent was obtained from all parents or guardians before the enrollment of children in the study .
approval for the study was obtained from the research ethics committee of the university of guerrero .
body weight was determined in light clothes and without shoes using a tanita body composition monitor ( tanita bc-553 , arlington , va ) , and the height was measured to the nearest 0.1 cm using a stadiometer ( seca , hamburg , germany ) . from these measurements , body mass index ( bmi ) was calculated ( bmi = weight / height , kg / m ) .
the classification of normal weight and obesity was made using the 2000 center for disease control and prevention growth charts defining as normal weight , fifth to 85th percentiles and obesity , 95th percentile or higher .
the body circumferences were measured in duplicate using a diameter tape accurate to within 0.1 cm ( seca 201 , hamburg , germany ) .
the thickness of 4 skinfolds was measured to the nearest 0.1 mm , in duplicate , using skinfold caliper ( dynatronics co , salt lake city , ut ) : triceps , biceps , subscapular , and suprailiac .
blood pressure was measured on the right arm of children seated at rest for at least 5 minutes .
two consecutive measures were obtained at 1-minute intervals with an aneroid sphygmomanometer ( riester ce 0124 , jungingen , germany ) .
biochemical parameters , such as ldl - cholesterol ( ldl - c ) , total cholesterol , hdl - cholesterol ( hdl - c ) , triglycerides ( tg ) , and fasting glucose levels , were analyzed immediately using a semiautomated equipment ( cobas mira ) .
insulin levels were measured using a commercially available enzyme - linked immunosorbent assay ( genway ins - easia kit ) . the homa index to determine insulin resistance
was calculated using the formula [ fasting insulin ( u / ml ) fasting glucose ( mmol / l)]/22.5 . a qualitative determination using enzyme - linked immunosorbent assay ( elisa )
was used to determine by duplicate the antibodies to ad-36 in the serum samples ( adv36-ab kit , cusabio ) .
we employed cut - off points from international diabetes federation proposal for children aged 1016 years old for blood glucose , and cut - off points for plasma lipid and lipoprotein levels are from the ncep expert panel on cholesterol levels in children .
differences in characteristics between groups were evaluated using the student 's t - test for parametric variables and the mann - whitney u test for nonparametric variables .
multiple regression models were used to analyze the association of ad-36 seropositivity with metabolic abnormalities .
the overall ad-36 seroprevalence was 73.9% . among children with or without obesity , differences were present according to ad-36 seropositivity ( figure 1 ) .
ad-36 seropositivity had a higher prevalence in obese children than in normal weight group ( 58.6 versus 41.4% , p = 0.007 ) .
however , ad-36 seropositive group resulted in a trend toward higher bmi ( p = 0.08 ) , systolic bp ( p = 0.07 ) , and total cholesterol ( p = 0.09 ) and triglycerides levels ( p = 0.09 ) than in ad-36 negative group .
the effect of ad-36 seropositivity on anthropometric and biochemical measurements was evaluated using the linear regression analysis , determining that the increase only of bmi ( = 1.58 , p = 0.03 ) , and triglycerides ( = 18.7 , p = 0.05 ) may be explained by ad-36 positivity ( table 2 ) . after adjustment for age and gender , ad-36 seropositivity was associated with obesity ( or = 2.66 , p = 0.01 ) and high - density lipoprotein < 40 mg / dl ( or = 2.85 , p = 0.03 ) ; other biochemical parameters were not related ( table 3 ) .
the ad-36 seropositive group had greater risk of 4 metabolic abnormalities compared with those children without none alteration ( table 4 ) .
in this study in mexican children , significant association between ad-36 seropositivity and obesity was found .
the overall ad-36 seroprevalence was 73.9% ( 41.4% and 58.6% in normal weight and obese children , resp . ) .
interestingly , a meta - analysis of 10 observational studies from around the world demonstrated that ad-36 infection was associated with the risk of obesity and weight gain , but was not associated with abnormal metabolic markers including waist circumference .
several studies determining the prevalence of ad-36 antibodies in obese people have been carried out in north america , sweden , italy , korea , and the netherlands . in brief , a cross - sectional study in 124 children reported that ad-36 positivity was present in 19 children ( 15% ) .
ad-36 positivity was significantly more frequent in obese children ( 15 [ 22% ] of 67 children ) than nonobese children ( 4 [ 7% ] of 57 children ) .
another study found that 30% of obese and 11% of nonobese subjects have neutralizing antibodies to ad-36 . in swedish individuals was show that ad-36 infection is associated with pediatric obesity , severe obesity in adult females and lower risk of high blood lipid levels .
also , ad-36 seropositivity was assessed in 68 obese and 135 nonobese italian subjects found that age , bmi , waist - hip ratio , blood pressure , insulin , homa , and triglycerides were significantly greater in the ad-36 seropositive group . in korean schoolchildren , obese group
have a higher prevalence of serum neutralizing antibodies to ad-36 than nonobese group ( 28.57 versus 13.56% , resp . ;
p = 0.0174 ) . in a study of 509 individuals from the netherlands and belgium ,
the overall ad-36 seroprevalence was 5.5% ( 3.9% and 5.7% in nonobese and obese subjects , resp . ) . in this study ,
the overall ad-36 seroprevalence was higher ( 73.9% ) compared with previous studies that have been carried out in usa , korea , and europe .
furthermore , it is very important to highlight that the prevalence found of ad-36 positive was very high in children with obesity ( 58.6% ) , in comparison with previous reports .
consequently , our study supports the view that the ad36-obesity association found in serum samples reflects obesity as a result of the infection , rather than the possibility that the ad36-obesity association reflects an obese state being more susceptible to ad-36 infection .
results of both in vivo and in vitro investigations have revealed that ad-36 infection accelerates the differentiation of preadipocytes into adipocytes and their proliferation in studies of 3t3-l1 cells and human preadipocytes [ 3 , 6 , 17 , 18 ] .
ad-36 infection also raises the lipid content of fat cells by promoting the uptake of lipids and glucose , which increases cellular lipid levels by stimulation de novo lipogenesis [ 19 , 20 ] .
moreover , multiple factors ranging from genetics to biology and behavior may contribute to obesity in an individual and they may vary between individuals , making it difficult to isolate the relative contribution of any single factor . therefore , the question of whether ad-36 contributes to human obesity has remained incompletely answered , although some investigators seem to be progressing in the right direction . the relationship of ad-36 infection with abnormal metabolic parameters has also been analyzed .
a meta - analysis of 10 observational studies demonstrated that ad-36 infection was not associated with abnormal metabolic markers including total cholesterol , hdl - cholesterol , triglycerides , and glucose levels , systolic blood pressure , and waist circumference .
interestingly , we found an association of ad-36 seropositivity with low hdl - c levels ( or = 2.85 , p = 0.03 ) , but other biochemical parameters were not related .
another study in the korean schoolchildren , reported that within the obese group , the adjusted or for the elevated triglycerides was significantly higher in ad-36 antibody - positive children than those who were ad-36 antibody - negative ( or = 2.328 , 95% ci : 1.2964.181 ) .
similarly , ad-36 was associated with lower serum lipids , cholesterol , and triglycerides ( p < 0.003 ) , in humans .
some evidence from animal studies showed in golden syrian hamsters that the cholesterol - lowering effect of ad-36 infection is associated with a shift in plasma cholesterol from high - density lipoprotein to low - density lipoprotein cholesterol .
another study , in wild - type ( wt ) mice and monocyte chemoattractant protein-1 knockout mice that were infected with ad-36 , found that ad-36 infected wt mice increased insulin sensitivity , and lipid parameters such as hdl - c , ldl - c , and total cholesterol concentrations were lower than in mock - infected wt mice .
the investigators assumed that mcp-1 regulates lipid metabolism in ad36-induced obesity through inflammation by increasing the level of mcp-1 by means of the activation of nuclear factor b . in our study ,
seropositive children to ad-36 had not difference in glucose and insulin levels compared to seronegative children . in contrast , natural ad-36 infection was cross - sectional associated with greater adiposity and better glycemic control in humans ; in this study compared longitudinal observations of glycemic control ( fasting glucose and insulin ) in ad-36 infected versus uninfected adults . in muscle cells
has been demonstrated that ad-36 increased gene expression and protein abundance of glut1 and glut4 , glut4 translocation to plasma membrane , and phosphatidylinositol 3-kinase ( pi3-kinase ) activity in an insulin - independent manner ; therefore may improve uptake of glucose and glycemic control in seropositive subjects .
the relationship between ad-36 and nonalcoholic fatty liver disease ( nafld ) is being investigated .
ad-36 seropositivity was associated with a lower occurrence of nafld and bright liver , which , conceivably , is not directly mediated by insulin resistance .
moreover , the role of ad-36 in weight loss in nafld subjects with nutritional interventional treatment was studied .
the subjects with previous infection have enhanced weight loss , bright liver disappearance , and recovery of insulin sensitivity .
also , in another study it was associated with ad-36 antibody status with response to a pediatric weight loss program in residential camp .
ad-36 antibody status showed a weak association with treatment response , but was associated with a better lipid profile .
the authors suggest that ad-36 antibody status should be assessed in studies of pediatric obesity treatment and prevention . in mexico , for the population in school age , from 5 to 11 years , the national prevalence combined of overweight and obesity in 2012 was 34.4% ( 19.8 and 14.6% , resp . ) . in our previous study ,
the prevalence of obesity and overweight in children were detected in 26.5% and 15.8% , respectively ; where the prevalence of obesity was 12% greater than the national prevalence .
therefore , one of the factors associated with the increase of obesity in children from guerrero may be adenovirus 36 positivity . in humans ,
adenoviruses are frequently associated with acute upper respiratory tract infections , and they may also cause enteritis and conjunctivitis . in mexico , there is a lack of published data about the etiological agents causing acute respiratory infections ; recently , it was reported that in a total of 100 , children 's nasopharyngeal samples showed a rate of adenovirus infection of 23% , and only ad - c was detected . in our study , children who were recruited had no symptoms of conjunctivitis or respiratory infection and nasopharyngeal samples were not obtained .
also , not asked whether children had these previous infections , therefore ad-36 specific antibodies may remain detectable long after the initial infection .
data for other adenovirus serotypes showed that antibodies reach undetectable levels within a 2-year period , but there are no available data on whether the time to reach undetectable levels is influenced by body weight .
in summary , this study provides evidence of the relationship of ad-36 seropositivity with obesity and low hdl - c levels .
moreover , ad-36 infection may contribute to increase the number of metabolic alterations in mexican children . | ### Summary:
: the human adenovirus 36 ( ad-36 ) is causally and correlatively associated in animals and humans , respectively , with increased adiposity and altered metabolic profile . in previous studies ,
the relationship between ad-36 seropositivity with obesity was established in adults and children .
we evaluated the association of positive antibodies to ad-36 with obesity and metabolic profile in mexican children .
seventy - five children with normal - weight and 82 with obesity were studied in this research .
all children had a clinic assessment which included weight , height , body circumferences , and skinfold thickness .
laboratory analyzes included triglycerides , total cholesterol , high - density lipoprotein , low - density lipoprotein , and glucose and insulin levels . an enzyme - linked immunosorbent assay ( elisa )
was used to determine the antibodies to ad-36 in the serum samples .
the overall ad-36 seroprevalence was 73.9% .
ad-36 seropositivity had a higher prevalence in obese children than in normal weight group ( 58.6 versus 41.4% , p = 0.007 ) .
ad-36 seropositivity was associated with obesity ( or = 2.66 , p = 0.01 ) and high - density lipoprotein < 40 mg / dl ( or = 2.85 , p = 0.03 ) .
the ad-36 seropositive group had greater risk of 4 metabolic abnormalities compared with those children without none alteration . in summary ,
ad-36 seropositivity was associated with obesity and low hdl - c levels in the sample of children studied . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: bioterrorism can be generally defined as the abuse of biological and microbial agents or their products to terrify or kill humans or animals .
limited bioterrorist actions are precedent from a long time ago , but recently it has been broadly introduced into medical and hygienic circles ( 1 - 3 ) and has compelled researchers to prioritize preventive measures in this regard ( 4 - 7 ) . despite the rare probability of a biological war , it can not be ignored ( 8 , 9 ) .
biological terrorist attack of tokyo subway , 1995 , caused 11 cases of death and thousands of hospitalization cases ( 10 ) .
following the event of september 11 , 2001 , the risk of a bioterrorist attack has become a real concern among rescue task forces .
one theoretical model in the united states declared that if a terrorist attack with biologic agents happened in a crowded city , it could lead to a mortality rate up to 32000/100000 ( 11 ) . decreasing post - disaster morbidity and mortality
depends on sufficient resources and acceptable level of knowledge , attitude , and preparedness among rescue task forces ( 12 - 14 ) . in iran ,
red crescent society is the most important organization in dealing with probable terrorist attacks . nevertheless , at the time of bioterrorist attacks
, its volunteers may have to confront difficulties such as identification of unknown microbial agents as well as working with limited equipment and in unknown environments ( 15 ) .
to date , there is no precise information regarding knowledge , attitude , and preparedness of iranian relief task force volunteers in management of probable bioterrorist attacks .
therefore , the aim of this study was to evaluate knowledge , attitude , and preparedness level of iranian red crescent society volunteers in biological and bioterrorist attack .
the questions queried about the volunteers knowledge , attitude , and the preparedness of respective organization about bioterrorist attacks
study design and setting
the present study is a prospective cross - sectional study on knowledge , attitude , and preparedness level of mahabad ( northwest iran ) red crescent society volunteers , in 2014 .
the required information was collected through a questionnaire , reliability of which was verified using a 40-case pilot study and test - retest method ( r = 0.78 ) .
the first part of the questionnaire included three questions regarding demographic data such as age , sex , and education .
the second part of it included 18 two - choice questions in three fields : volunteers knowledge ( four questions ) , volunteers attitude to participate in rescue teams at the time of bioterrorist attacks ( six questions ) , and the preparedness of red crescent society in dealing with bioterrorist attacks from volunteers viewpoint ( eight questions ) ( table 1 ) .
the protocol of this study was approved by the local ethics committee of red crescent society .
the studied population included volunteers who had passed at least one rescue course ( consisting of 4 different 2-day workshops ) in disaster management .
volunteers who did not want to participate or filled the forms incompletely were excluded .
statistical analysis
the required sample size was determined to be at least 77 cases considering the 72% prevalence ( p = 0.72 ) of poor knowledge ( 12 ) , = 0.05 , and desired precision of 0.1 ( d = 0.1 ) .
the quantitative data were reported as mean and standard deviation , and the qualitative ones were reported as frequency and percentage .
each positive answer to the questions gained 1 point , while negative answers received 0 points .
therefore , the maximum achievable scores for knowledge , attitude , and preparedness were 4 , 6 , and 8 , respectively .
the knowledge score 0 was considered as poor , 1 and 2 as moderate , and 3 and 4 as good knowledge .
in addition , the attitude score 3 was defined as inappropriate and score > 3 as appropriate attitude .
the preparedness level was rated inappropriate if preparedness score was 0 - 4 and appropriate if it was 5 - 8 .
mean age of the volunteers was 32 8.2 years ( range : 20 - 51 years ) .
34 ( 28.3% ) of the participants had diploma , 25 ( 20.8% ) had associate degree , 52 ( 43.3% ) had bachelor s degree , and 9 ( 7.5% ) had master s degree or higher .
table 1 summarizes the frequency of positive and negative responses to the 18 mentioned questions .
6 ( 5.0% ) cases had knowledge about causative and pathogenic characteristics of biologic agents . 2 ( 1.7% ) cases had good knowledge about bioterrorist attacks and their management ( figure 1 ) .
while 94 ( 78.3% ) cases had no knowledge about how to encounter and manage bioterrorist attacks .
five ( 4.2% ) cases had the tendency to cooperate with the responsible organizations and 12 ( 10.0% ) cases declared that they would participate if protective equipment were available .
three ( 2.5% ) cases were willing to take care of the probable victims of bioterrorist attacks . only one ( 0.8% ) volunteer had an appropriate attitude and 119 ( 99.2% ) had inappropriate attitude toward participation in bioterrorism relief task forces .
the volunteers knowledge regarding management of bioterrorist attacks based on volunteers answers , no training workshops and seminars had been held so far regarding biological and bioterrorist attacks .
one ( 0.8% ) case stated that the red crescent society provided the required financial supports for facing biological and bioterrorist attacks .
two ( 1.7% ) cases declared that recorded instructions , guideline , or training courses had been explained by the central organization .
ten ( 8.3% ) cases expressed that the respective organization had considered their worries and concerns about the security of their own selves and their families at the time of facing biological and bioterrorist attacks .
23 ( 19.2% ) cases said that the central organization considered the personal requirements during educational planning for preparedness against bioterrorist attacks . from the viewpoint of 116 ( 96.7% ) volunteers , mahabad red crescent society had inappropriate preparedness to encounter bioterrorist attacks ( figure 2 ) . the preparedness of mahabad red crescent society to encounter bioterrorist attacks from the volunteers viewpoint
the findings of this study showed that only 1.7% of the iranian red crescent society volunteers had good knowledge about management of bioterrorist attacks .
99.2% had inappropriate attitude , and 96.7% believed that preparedness of mahabad red crescent society is poor about encountering bioterrorist attacks .
the findings of present study is in line with previous investigations in this regard ( 13 , 14 ) . in an evaluation of nurses awareness about bioterrorism agents , 72.5% had poor knowledge in this field ( 12 ) .
in addition , an investigation in 2002 concluded that physicians did not have the necessary and satisfactory level of knowledge in bioterrorism management and declared the necessity of training courses in this regard ( 16 ) .
one study showed that higher knowledge of rescuers increased their tendency to respond in bioterrorist attacks ( 17 ) .
thus , training the volunteers is of high importance in order to increase their willingness for relief in contaminated areas .
holding different scientific seminars and symposiums and fitting different training plans in the field of bioterrorism as optional courses into syllabuses of universities and responsible organizations , can be a worthy donation to elevate the knowledge level of society s experts . in iran ,
red crescent society along with military forces are on the frontline of biological and anti - bioterrorist defense
. they must provide necessary resources such as antidotes , antibiotics , antitoxins , and intensive care equipment like ventilators . at the time of bioterrorist attacks ,
quick and timely response is so important that even seconds can save thousands of lives .
the required facilities and equipment for combating against bioterrorist attacks must always be prepared and ready to work to prevent waste of time in such events . during such disasters
, there is an increase in consumption of resources and some rarely - used equipment , which causes shortage of equipment during a bioterrorist attack ( 18 ) .
unfortunately , based on the viewpoint of the study participants , we are faced with inappropriate preparedness of mahabad red crescent society in dealing with bioterrorist attacks , which requires special attention to improve .
finally , it is thought that elevating the knowledge and attitude of health care providers and training them in the backbone field of biological defense can result in a better and more efficient battle against probable bioterrorist attacks .
the findings of the present study showed poor knowledge and inappropriate attitude of mahabad red crescent society volunteers in encountering with probable bioterrorist attacks .
furthermore , the red crescent society of this town had an inappropriate level of preparedness in the field of bioterrorism from the viewpoint of the studied volunteers .
all authors passed four criteria for authorship contribution based on recommendations of the international committee of medical journal editors . | ### Summary:
: introduction : bioterrorism is a worldwide problem and has been the focus of attention during recent decades . there is no precise information on the knowledge , attitude , and preparedness of iranian red crescent volunteers in dealing with bioterrorism .
therefore , the present study aimed to evaluate the above - mentioned parameters in mahabad red crescent society volunteers . methods : in this prospective cross - sectional study , the knowledge of 120 volunteers was evaluated and rated as poor , moderate , and good .
in addition , attitude of the volunteers and preparedness of mahabad red crescent society was rated as inappropriate and appropriate using a questionnaire .
results : the mean age of volunteers was 32.0 8.2 years ( 62.5% male ) .
2 ( 1.7% ) volunteers had good knowledge while 94 ( 78.3% ) had no knowledge regarding bioterrorist attack management . only 1 ( 0.8% ) volunteer had appropriate attitude and 6 ( 5.0% ) stated their preparedness for being sent out to the crisis zone .
116 volunteers ( 96.7% ) indicated that mahabad red crescent society has an inappropriate level of preparedness to encounter bioterrorist attacks .
conclusion : the findings of the present study showed poor knowledge and inappropriate attitude of mahabad red crescent society volunteers in encountering probable bioterrorist attacks .
furthermore , the red crescent society of this town had an inappropriate level of preparedness in the field of bioterrorism from the viewpoint of the studied volunteers . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: fungi sense and interact with the environment by changing their pattern of growth and their metabolism , and light is one of the signals that regulates fungal biology ( corrochano & avalos 2010 ) .
a prominent example of the effect of light in fungi is the regulation by light of fungal development and behaviour ( fig .
in addition , blue light can activate fungal metabolic pathways or direct the growth of fungal structures ( idnurm et al .
photoreceptors are molecules that receive photons through specialized light - absorbing chromophores and transduce the photon energy into the cell to promote a response , and several types of photoreceptors have been described in fungi ( corrochano 2007 , herrera - estrella & horwitz 2007 ) .
the isolation and characterization of fungal photoreceptors was initiated by the isolation of the neurospora wc-1 and wc-2 genes ( ballario et al .
1996 , linden & macino 1997 ) required for all the photoresponses in this fungus .
this was followed by the characterization of the wc-1 gene product , wc-1 , as a photoreceptor with dna - binding capacity , that operates with its partner , wc-2 ( froehlich et al .
genes similar to wc-1 and wc-2 have been identified in the genomes of several ascomycete , basidiomycete , and zygomycete fungi , and many of these genes are required for fungal photoresponses , leading to the hypothesis that the wc complex arose early in fungal evolution to regulate fungal photoresponses as a photoreceptor and transcription factor ( idnurm & heitman 2005 ) .
in addition , the completion of several fungal genomes has allowed the identification of additional fungal photoreceptor genes , many of them unexpected like red light absorbing photoreceptors , phytochromes , additional blue - light absorbing photoreceptors , cryptochromes , and rhodopsins ( galagan et al .
we provide a summary of the presentations made during the special interest group meeting on fungal photobiology that took place during the 9th international mycological congress ( imc9 ) in edinburgh during august 2010 .
the aim of the meeting was to discuss recent developments in the molecular mechanisms of fungal photoreception and to review the different responses to light observed in different classes of fungi .
the meeting was organized by myself with the help of the organizing committee of imc9 and took place during the morning of 1 august 2010 .
the five presentations covered various aspects of fungal photobiology in a wide array of fungi , including zygomycetes , basidiomycetes , and ascomycetes .
gerhard braus ( georg - august - university goettingen ) and julio rodrguez - romero ( university of karlsruhe ) described different aspects of light reception in the ascomycete aspergillus nidulans , and gencer sancar ( university of heidelberg ) reported on recent developments in the molecular mechanisms that regulate the circadian clock in the ascomycete neurospora crassa .
the responses to light in the zygomycete mucor circinelloides were discussed by victoriano garre ( university of murcia ) , and takashi kamada ( okayama university ) reviewed recent results on the regulation by light of basidiome development in the basidiomycete coprinopsis cinerea . in aspergillus nidulans
red and blue light regulate the balance between sexual and asexual development , and many proteins , including photoreceptors , participate in this regulation .
interestingly , many of these regulatory proteins interact to form protein complexes , and the formation of these complexes , and their localization within the cell are key features for their roles in the regulation of development ( bayram et al .
braus discussed how a protein complex composed of proteins velb , vea , and laea is required for the proper regulation by light of sexual development ( bayram et al .
in addition , velb forms a complex with vosa , which is required for spore viability and resistance to various stresses .
the laea protein was initially identified as a global regulator of secondary metabolism and plays a key role in the crosstalk between both complexes ( sarikaya bayram et al .
2010 ) . in a. nidulans red light is perceived by a phytochrome , fpha , and blue light is mostly perceived by the wc-1 homolog lrea .
the phytochrome is required for the inhibition by red light of sexual development ( blumenstein et al .
2005 ) and both , fpha and lrea , interact in a protein complex that includes vea ( purschwitz et al .
light activates gene transcription , and the talk by rodrguez - romero summarized the results obtained by microarray hybridizations to identify genes differentially regulated by light and how blue light and red light is required for this regulation .
both the red light photoreceptor phytochrome ( fpha ) and the blue light receptor lrea were required for light - dependent gene activation .
the presence of photoreceptor proteins in the promoter of light - regulated genes suggested a direct role for these proteins in photoreception and gene transcription .
in neurospora light promotes the accumulation of orange pigments ( carotenoids ) in vegetative mycelia , promote asexual ( conidiation ) and sexual development , and resets the circadian clock ( chen et al .
all these responses require wc-1 and wc-2 , two proteins that form a photoreceptor and transcription factor complex ( wcc ) that binds the promoters of light - regulated genes to activate transcription .
in addition , a small blue - light photoreceptor ( vvd ) interacts with the wcc to modulate its activity and to allow neurospora to react to changes in light intensities ( chen et al .
sancar summarized recent work that helped to identify wcc binding sites along the entire neurospora genome by chip - seq technology after a brief illumination ( smith et al . 2010 ) .
the wcc was found in about 400 regions in the genome , and half of them where located in promoters of genes .
the wcc was found to directly control the expression of 24 transcription factor genes , including the clock - controlled gene adv-1 .
the presence of the wcc in the promoters of transcription factor genes confirmed previous observation of a hierarchical regulation in the response to light with the wcc activating a set of transcription factor genes that eventually would activate additional genes responsible for the cellular response ( chen et al .
the responses to light have been extensively investigated in the zygomycete phycomyces blakesleeanus , in particular since it was promoted as a model organism for sensory perception by nobel laureate max delbrck in the mid-1950s ( bergman et al .
a less known but very promising zygomycete with several light responses is mucor circinelloides , a fungus that can be easily transformed with exogenous dna , unlike phycomyces ( gutirrez et al .
light promotes the accumulation of beta - carotene and the phototropism of the fruiting body of mucor ( silva et al .
garre reviewed the identification of multiple wc genes in the mucor genome , a trait observed in other zygomycetes including phycomyces ( corrochano & garre 2010 ) .
the genome of mucor contains three wc-1 genes and four wc-2 genes , but only the role of the wc-1 genes has been investigated in detail ( silva et al .
in addition , the product of mcwc-1b is an activator of photocarotenogenesis , but the activation is blocked by ubiquitylation mediated by the repressor crga ( silva et al .
however , one wc-1 gene , mada , and one wc-2 gene , madb , are required for all the responses of this fungus to light ( idnurm et al .
the corresponding proteins , mada and madb , interact to form a protein complex , presumably similar to the wcc in neurospora , that allows phototropism and other responses to light ( sanz et al . 2009 ) .
the function of the other wc genes is currently unknown , but they are induced by light and may provide additional light - sensing components to the basic mad complex for extended sensitivity to light ( sanz et al .
mushroom development requires an appropriate light / dark cycle , and this light - dependent developmental regulation has been investigated in detail in the basidiomycete coprinopsis cinerea ( kamada et al . 2010 ) .
kamada summarized the effect of light on coprinopsis development and the identification of blind mutants that produce etiolated dark stipes under light / dark cycles that would result in full mushroom development in the wild type .
the product of dst1 has been identified as a homologue of the neurospora wc-1 gene ( terashima et al .
2005 ) , while dst2 encodes a protein with a putative flavin adenine dinucleotide ( fad ) domain ( kuratani et al .
the presence of this domain suggests that the product of dst2 could be a novel fungal photoreceptor , but further work is still necessary to confirm this hypothesis .
proteins similar to wc-1 and wc-2 , have been identified in most fungi , and many of them are required for their responses to light .
in addition , most fungal genomes contain genes for other photoreceptors , but their roles in the fungal cell are largely unknown .
the sig meeting on fungal photobiology helped to review the current status of fungal photoreceptors and photoresponses and to propose new avenues of research and collaborations . | ### Summary:
: fungi respond and adapt to many environmental signals including light .
the photobiology of fungi has been extensively investigated , but in recent years the identification of the first fungal photoreceptor , wc-1 in the ascomycete neurospora crassa , and the discovery that similar photoreceptors are required for photoreception in other ascomycete , basidiomycete and zygomycete fungi has allowed the molecular characterization of light reception and the early steps of signal transduction in a number of model fungi .
this contribution is based on presentations made at the special interest group meeting on fungal photobiology held during imc9 .
the contributions summarize the current status of fungal photobiology in aspergillus nidulans , neurospora crassa , mucor circinelloides , and coprinopsis cinerea . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: more than half of the deaths in children are caused by diseases that could be treated with safe , essential , and child - specific medicines .
most of the health expenditure in india including the cost of medicines is met from out of pocket expenses of the patients .
odisha is an eastern indian state with an infant mortality rate that is the second highest in the country .
public health facilities provide about 90% of medical care , and the organized private sector is very thin for the state . despite the peoples reliance on the public system , evidence has highlighted huge gaps and have suggested that institutions do not operate at optimal levels .
the present study aims at exploring the availability of different essential child - specific formulations and prices the patient pays to purchase these medicines in different health sectors of odisha .
this observational cross - sectional study was conducted as part of better medicines for children project in india .
requisite permission from the director of health services and drugs controller of odisha was obtained before initiating the study .
the survey used a standard methodology for measuring medicine prices and availability developed by who and health action international ( hai ) .
the survey work was conducted in six randomly selected districts of odisha ( cuttack , sambalpur , ganjam , kalahandi , kandhamal , and balasore ) from different geographical locations of the state and were conducted from september 15 , 2010 to april 15 , 2011 [ figure 1 ] .
map of odisha state with six districts of odisha state covered for medicine survey in each district , the major urban health center was selected as one central area , and an additional five areas were chosen randomly from different geographical locations of the district ( that could be reached within a day 's drive from the central survey point or headquarter ) so that the collected data represent the data for the whole district . from the public sector , ten primary health centers , two community health centers , one district headquarter hospital , and one medical college hospital were included that constituted 14 sample areas for the survey .
thus , 79 outlets were surveyed in each of the public , and private sectors and five outlets were surveyed in the nongovernmental organization ( ngo)/mission sector ( other sector ) .
all survey personnel received training on the standard survey methodology and data collection / data entry procedures at a training workshop .
government procurement data were obtained from the state drug management unit ( sdmu ) in bhubaneswar that serves as the central procurement agency for the whole state . a total 34 child - specific formulations [ table 1 ] were selected based on recommendations of the committee that was engaged in the preparation of the child - specific essential medicines list for the state . for each formulation , a specific pack size was searched for in order to obtain a uniform unit price [ table 1 ] . for each available medicine , highest - price , and
list of medicines surveyed availability of different surveyed medicines and medicine unit prices were entered into the preprogrammed ms excel workbook ( who - hai workbook ver 5 msh2009-part i , orissa ) provided as part of the who / hai methodology .
data entry was checked using the double entry , data checker , and automated analysis features of the workbook .
the exchange rate used to calculate median price ratios ( mprs ) was us$ 1 = rs . 45.20 ; this was the commercial buy rate taken from a local bank on the 1 day of data collection .
the 2009 management sciences for health reference prices , taken from the international drug price indicator guide was followed for comparison of prices .
in each district , the major urban health center was selected as one central area , and an additional five areas were chosen randomly from different geographical locations of the district ( that could be reached within a day 's drive from the central survey point or headquarter ) so that the collected data represent the data for the whole district . from the public sector , ten primary health centers , two community health centers , one district headquarter hospital , and one medical college hospital were included that constituted 14 sample areas for the survey .
thus , 79 outlets were surveyed in each of the public , and private sectors and five outlets were surveyed in the nongovernmental organization ( ngo)/mission sector ( other sector ) .
all survey personnel received training on the standard survey methodology and data collection / data entry procedures at a training workshop .
government procurement data were obtained from the state drug management unit ( sdmu ) in bhubaneswar that serves as the central procurement agency for the whole state . a total 34 child - specific formulations [ table 1 ] were selected based on recommendations of the committee that was engaged in the preparation of the child - specific essential medicines list for the state . for each formulation , a specific pack size was searched for in order to obtain a uniform unit price [ table 1 ] . for each available medicine , highest - price , and
list of medicines surveyed availability of different surveyed medicines and medicine unit prices were entered into the preprogrammed ms excel workbook ( who - hai workbook ver 5 msh2009-part i , orissa ) provided as part of the who / hai methodology .
data entry was checked using the double entry , data checker , and automated analysis features of the workbook .
the exchange rate used to calculate median price ratios ( mprs ) was us$ 1 = rs . 45.20 ; this was the commercial buy rate taken from a local bank on the 1 day of data collection .
the 2009 management sciences for health reference prices , taken from the international drug price indicator guide was followed for comparison of prices .
in each district , the major urban health center was selected as one central area , and an additional five areas were chosen randomly from different geographical locations of the district ( that could be reached within a day 's drive from the central survey point or headquarter ) so that the collected data represent the data for the whole district . from the public sector , ten primary health centers , two community health centers , one district headquarter hospital , and one medical college hospital were included that constituted 14 sample areas for the survey .
thus , 79 outlets were surveyed in each of the public , and private sectors and five outlets were surveyed in the nongovernmental organization ( ngo)/mission sector ( other sector ) .
all survey personnel received training on the standard survey methodology and data collection / data entry procedures at a training workshop .
government procurement data were obtained from the state drug management unit ( sdmu ) in bhubaneswar that serves as the central procurement agency for the whole state .
a total 34 child - specific formulations [ table 1 ] were selected based on recommendations of the committee that was engaged in the preparation of the child - specific essential medicines list for the state . for each formulation , a specific pack size was searched for in order to obtain a uniform unit price [ table 1 ] . for each available medicine , highest - price , and
availability of different surveyed medicines and medicine unit prices were entered into the preprogrammed ms excel workbook ( who - hai workbook ver 5 msh2009-part i , orissa ) provided as part of the who / hai methodology .
data entry was checked using the double entry , data checker , and automated analysis features of the workbook .
the exchange rate used to calculate median price ratios ( mprs ) was us$ 1 = rs . 45.20 ; this was the commercial buy rate taken from a local bank on the 1 day of data collection .
the 2009 management sciences for health reference prices , taken from the international drug price indicator guide was followed for comparison of prices .
the survey revealed that public sector availability was low at 17.0% with very high deviation in availability ( 26.3 ) with the exception of ofloxacin , oral rehydration solution ( ors ) ( for 1 l ) and albendazole suspension .
innovator branded products were rarely available even in private sectors of odisha . in the private sector ,
a range of drug products was available for some surveyed medicines which were categorized as low priced or high priced .
availability of lowest - priced generics in the private sector was better ( 38.5% ) than in the public sector [ table 2 ] .
high - priced branded generic products were also found in the private sector ; with an average availability of 10.8% .
availability of lowest - priced generic medicines in ngo / mission sector facilities was found out to be 21.8% .
only one drug product was available at a particular time in both public sector and other sector ( ngo / mission ) outlets .
comparison of mean availability ( % ) of all surveyed medicines on the day of data collection , in three different sectors of odisha ors ( for 1 l ) was widely available with 85% or more in all three sectors .
dispersible zinc tablets , however , were scarce with the availability of < 5% in all the three sectors .
availability of antibiotics was consistently less in more than 60% of outlets except ofloxacin 200 mg tab [ figure 2 ] . from the antiasthmatic group , beclomethasone inhaler was scarce with < 5% availability in all three sectors [ table 3 ] .
salbutamol inhaler was found both in the public and private sectors ( 51.2% and 64.6% , respectively ) , but was not available in the ngo / mission sector .
no antiepileptic preparation was available in public sector facilities . in the private sector , the valproic acid oral syrup was most commonly available ( 42.7% ) .
availability of antibiotics in the public and private sector comparison of the availability of individual medicines , in three different health sectors of odisha the study revealed that government procurement agency ( sdmu ) is purchasing medicines at approximately half the international reference prices ( mpr of 0.52 ) that suggest relatively efficient purchasing though the number of medicines procured is less .
table 4 depicts the median values have been depicted along with corresponding 25 and 75 percentiles . in the private sector ,
the lowest price generic medicines were being sold at 1.46 times their international reference price .
half the lowest - priced medicines were priced at 1.062.29 times their international reference price while half of the highest - priced medicines were priced between 1.57 and 2.67 .
highest - priced products were sold at 1.83 times their international reference price , with similar variation across individual medicines as observed with the lowest - priced generics . out of the highest - priced and lowest - priced products of nine medicines in the private sector ,
highest - priced products cost 24.5% more , on an average , than their lowest - priced equivalents . in ngo / mission sector facilities ,
however , results are based on four medicines only due to low availability of surveyed medicines in this sector .
when the prices of these four medicines were compared with those in the private sector , they were found to cost 12.4% more . out of 34 medicines surveyed , the price of some medicines showed substantial variation across individual private sector outlets .
comparison of ratio of median unit prices between public and private sector medicines showing large price variations across outlets in private sector
the study revealed that government procurement agency ( sdmu ) is purchasing medicines at approximately half the international reference prices ( mpr of 0.52 ) that suggest relatively efficient purchasing though the number of medicines procured is less .
table 4 depicts the median values have been depicted along with corresponding 25 and 75 percentiles . in the private sector ,
the lowest price generic medicines were being sold at 1.46 times their international reference price .
half the lowest - priced medicines were priced at 1.062.29 times their international reference price while half of the highest - priced medicines were priced between 1.57 and 2.67 .
highest - priced products were sold at 1.83 times their international reference price , with similar variation across individual medicines as observed with the lowest - priced generics . out of the highest - priced and lowest - priced products of nine medicines in the private sector ,
highest - priced products cost 24.5% more , on an average , than their lowest - priced equivalents . in ngo / mission sector facilities ,
however , results are based on four medicines only due to low availability of surveyed medicines in this sector .
when the prices of these four medicines were compared with those in the private sector , they were found to cost 12.4% more .
out of 34 medicines surveyed , the price of some medicines showed substantial variation across individual private sector outlets .
comparison of ratio of median unit prices between public and private sector medicines showing large price variations across outlets in private sector
the study revealed that government procurement agency ( sdmu ) is purchasing medicines at approximately half the international reference prices ( mpr of 0.52 ) that suggest relatively efficient purchasing though the number of medicines procured is less .
table 4 depicts the median values have been depicted along with corresponding 25 and 75 percentiles . in the private sector ,
the lowest price generic medicines were being sold at 1.46 times their international reference price .
half the lowest - priced medicines were priced at 1.062.29 times their international reference price while half of the highest - priced medicines were priced between 1.57 and 2.67 .
highest - priced products were sold at 1.83 times their international reference price , with similar variation across individual medicines as observed with the lowest - priced generics . out of the highest - priced and lowest - priced products of nine medicines in the private sector ,
highest - priced products cost 24.5% more , on an average , than their lowest - priced equivalents . in ngo / mission sector facilities ,
however , results are based on four medicines only due to low availability of surveyed medicines in this sector .
when the prices of these four medicines were compared with those in the private sector , they were found to cost 12.4% more .
out of 34 medicines surveyed , the price of some medicines showed substantial variation across individual private sector outlets .
comparison of ratio of median unit prices between public and private sector medicines showing large price variations across outlets in private sector
in the public sector of odisha , medicines are procured centrally by the state government and are made available to all patients free of cost .
results of the survey indicate that most of surveyed medicines had poor availability in public sector outlets . the high standard deviation associated with mean availability ( 17 26.3 ) suggests high variation in availability of these vital medicines across the public health outlets .
the study also reveals that availability of medicines with central procurement agency is not matching with medicine availability at secondary or primary care outlets .
this suggests that drug supply chain management is not efficient apart from inadequate procurement of medicines for the children .
given the low availability of medicines in the public sector , it can be derived that most patients are purchasing medicines from the private sector or going without medicines in a state with documented high child mortality .
our findings also match with that of chhattisgarh , the state in which similar study was undertaken as a part of better medicines for children project in india .
availability of children 's medicine was 17% in both public and other sectors of chhattisgarh .
the chhattisgarh survey has revealed that out of 50 child medicines surveyed for the state , 29 medicines were not available in any of the facilities .
low availability of medicines in the present study also match with other south east asian regions .
a study in shaanxi provinces of china has shown that mean availability of originator brand and generic medicines in the public sector were 7.1% and 20.0% , respectively .
a similar study at srilanka has also proved that treatment for chronic illnesses requiring liquid or inhaled dosage forms were not available or afforadble . for treatment of malaria , which contributes to significant morbidity and mortality of children in the state ,
unfortunately key antimalarial medicine artemisinin combination therapy act ( artemether + lumefantrine ) was available in only 39% of private sector outlets of odisha .
the current need is to procure act in appropriate child - specific dosages to reduce the high mortality rates of children due to the high prevalence of falciparum malaria in this state .
good availability of ors in public facilities may be due to the efficient procurement or less utilization .
dispersible tablets of zinc are not procured by the government of odisha , and their availability is only 2.4% , which is purchased locally by few district authorities .
the high availability of ofloxacin and 1 l ors in more than 90% government outlets suggest that one efficient system for drug supply is existing in the state .
rare availability of innovator branded products may be due to low paying capacity of people .
the private sector patient prices were higher than international reference prices , with median mprs of 1.46 and 1.83 for the lowest - priced and highest - priced products , respectively .
usually , medicines are not found to be priced consistently with respect to their international reference price .
the range ( interquartile ) of mprs in the private sector ; shows the variability in the medicine price across medicine outlets .
this high variability of price between private sector outlets is likely the result of low market competition and the absence of proper price regulation . in india , because of predominant branded generic market , drug products are available in various strength and formulation as per the marketing strategy of the pharmaceutical companies .
many international studies also have revealed that it 's very difficult to maintain uniform drug price .
high variation of the cost for some medicines [ table 5 ] also suggests that private facilities are keeping , medicine product of their own choice to gain maximum financial benefit .
thus , government through regulatory authorities needs to import more child - specific formulations with strict price regulation .
the strategic policy is needed to be kept in place to keep selected essential life - saving medicines for children in all medicine outlets .
this standard methodology has allowed the estimation of medicine prices and availability in a reliable and standardized way that enables valid international comparisons .
a further strength of the methodology is the multiple steps taken to ensure data quality control checks .
the only limitation of this work is that availability is determined for the selected list of survey medicines and , therefore , does not account for the availability of alternate strengths or dosage forms , or of therapeutic alternatives .
looking at the poor availability of medicines and low procurement price in the public sector , it was recommended that government of odisha should prepare a separate essential medicine list for children and procure these medicines on an urgent basis .
the results of this study suggest that availability of child - specific medicines is extremely poor in all the three sectors of odisha state . the price patients pay for purchasing children 's medicine
thus , appropriate policies need to be implemented to make the child - specific medicines available in odisha . who searo , new delhi .
| ### Summary:
: objectives : continuous availability of affordable medicines in appropriate formulations is essential to reduce morbidity and mortality in children . odisha an eastern indian state records very high mortality of children .
the study aims at documenting the availability and prices paid for purchasing essential child - specific medicines.materials and methods : the survey of 34 essential medicines was conducted in six randomly selected districts of odisha .
data were collected from medicine outlets of the public , private , and other sector ( nongovernmental organization [ ngo]/mission sectors ) of six randomly selected districts , using who / health action international medicine price collection methodology . for each medicine surveyed , data were collected on the highest and lowest - priced formulations available in each facility.results:both public sector and other sector health facilities procure only one brand of medicines , mean percentage availability of medicines being 17% and 21.8% , respectively . in the private sector , the mean percentage availability of the high and lowest - priced medicines for a particular drug product was 10.8% and 38.5% , respectively .
the public sector procurement price is 48% lower than international reference prices . in the private sector ,
high - priced , and low - priced products are sold at 1.83 and 1.46 times the international reference price , respectively .
substantial price variation was observed for some medicines across individual outlets .
medicines were found to cost 2.08 times their international reference price in ngo / mission sector facilities.conclusions:the availability of children 's medicines in public sector facilities of odisha state is poor .
medicines for children cost relatively high in both private and ngo sectors compared to the international reference price .
the availability medicines should be improved on an urgent basis to improve access of medicines for children of odisha . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: cancer is a major cause of death worldwide . in 2008 , 12.7 million cases of the disease were diagnosed globally and 7.6 million individuals lost their lives as a result of the condition.1 cervical cancer is a leading public health concern globally . although a decline has been observed in cervical cancer incidence and deaths in the developed world over the past 20 years , there has not been a significant change in the same key indicators in poor resource settings . in ghana
, cervical cancer is the most common cancer affecting women , with 50.5% attributed to human papillomavirus ( hpv ) types 16 and 18 , and is the cause of 16% of mortality due to cancer.2 the world health organization ( who ) has estimated additional cases of cervical cancer to be over 5,000 in ghana with at least 3,300 deaths every year by 2025.3 it is difficult to ignore the problem of cervical cancer in ghana . greater proportions of women of reproductive age are at high risk of developing cervical cancer as there is no systematic national screening or treatment available.24 cervical cancer screening services in ghana are not common and are restricted as the test is done in few public health facilities in the country and is patronized by referrals and a few who know about pap smears .
adanu4 and gaffikin et al5 reported that the cervical cancer screening situation in ghana was not helped by the lack of a comprehensive national screening program , thus limiting the number of women who receive screening .
adanu4 and duda et al6 reported low rates of patronage of cervical cancer screening services among a cross - section of women in accra , ghana .
nonetheless , routine tests with pap smears can greatly minimize the risks of dying from cervical cancer .
pap smear tests have decreased annual worldwide mortality rates associated with cervical cancer by approximately 2% each year since its introduction in 1941.7 it is known to have reduced the overall mortality rate by 74% .
the test is considered the most effective cancer - screening technique ever discovered.7 asides the pap smear , alternative screening approaches that have been explored for the prevention of cervical cancer in low
middle income countries include visual inspection with acetic acid ( via ) , visual inspection with lugol s iodine ( vili ) , cervicography , and speculoscopy .
these approaches are simple , yet cost - effective , and could promote a screen and treat mechanism that entails diagnosis and treatment at a single visit.8,9 utilization of the pap smear test for cervical cancer prevention and control would contribute to the attainment of the millennium development goals through universal access to sexual and reproductive health services to improve women s health.2 for instance , in mozambique it is part of the national family planning program . in cote dlvoire , zambia , and botswana ,
these integrations have resulted in high rates of screening uptake.10 although cervical cancer is preventable , and knowledge of the condition and early screening might decrease the mortality associated with it , most women report to the hospital with an advanced form of the disease due to lack of awareness and community level interventions to encourage screening .
some empirical studies in cervical cancer screening in ghana have been carried out in urban and university settings and among women who attended hospitals .
for instance , some studies examined the knowledge and attitudes of college students regarding cervical cancer screening.411 studies conducted by abotchie and shokar11 and adanu et al12 have suggested that women did not have adequate information on what cervical cancer screening was about as well as local screening initiatives . as a result ,
in addition , quentin et al13 argued that the high cost of screening and treatments were important barriers toward seeking cervical cancer screening tests in kumasi , ghana .
to date , no study has exclusively studied the knowledge , practice , and barriers regarding cervical cancer screening among women in ghana .
this study is the first to document such important information that might be crucial in facilitating planning community level interventions necessary to reduce morbidity and mortality from the disease .
elmina is situated in the central region of ghana , which is second to the upper west in the proportion of females who engage in sexual activity before 15 years of age.14 most of these activities are high - risk behaviors.15 the ghana demographic and health survey 2008 reported that only 28.6% of women in the central region of ghana who had higher risk sexual intercourse did so using a condom.16 this might predispose young girls to hpv . additionally , ghana has an estimated hiv prevalence of 1.4% .
the central region of ghana recorded an hiv prevalence of 4.7% in the hiv sentinel survey.17 it is already known that hiv and hpv act in synergy to cause cervical neoplasia.1821 according to the 2010 population and housing census statistics , elmina has a total female population of 20,305.15 the target population for this study included women who are 1074 years and are sexually active . although screening is not recommended for 10-year - olds , they were included in the study as we were testing their knowledge of risk factors for cervical cancer ; if they were knowledgeable on the subject , the likelihood of them seeking cervical screening at the appropriate time might be greater .
the women were residents of elmina who were available at the time of data collection . the sample excluded women who normally do not reside in elmina and those who were mentally challenged .
the criteria for determining the sample size for this study was based on the purpose of the study , size of the population , level of precision , the level of confidence or risk , and the degree of variability in the attributes being measured.19 cluster or multistage sampling design was used in this study .
random sampling is a form of probability sampling technique where each unit of the population has an equal chance of inclusion in the sample.20 based on the 2010 census data , elmina has a total of 15 communities . using the ballot approach , five communities ( bronyibima , bantoma , elmina traditional , pershie , and tetterkessimu ) were randomly chosen out of the 15 .
second , the probability proportionate to size approach was employed in selecting the households within each community . in order to select the study participants within the households in each community , a coin was tossed and the direction where the head pointed was used to select the first household .
it was expected that at least two - thirds of those households would have women that met the inclusion criteria .
maps were available delineating the geographical area for the study and indicating major roads as well as individual households .
recruitment of subjects was conducted at churches , community centers , health centers , and schools by word of mouth and on the local radio . in order to get women who fell within the inclusion criteria to participate in the study at the household level
, interviewers inquired from heads of households if they had such women in their households .
data were collected from women who were available at the time of data collection . for those who had either gone to work or were not available , effort was made to obtain data from them at a later date ( early in the morning or in the evening when they were at home ) .
a structured interview schedule was used to collect relevant data for the study and was adopted from that used by mupepi et al.21 the structured interview schedule offered a closed set of responses from which the respondents could choose .
the structured interview schedule identified the sociodemographic characteristics of respondents , their knowledge and practice of cervical cancer screening , and the barriers toward cervical cancer screening .
the instrument was pre - tested among 20 women in a nearby community in order to check adequacy of the questions in terms of wording , clarity , and ambiguity.20 to ensure face validity and content validity , the questions were constructed congruently with the specific research questions and the literature review .
cronbach s coefficient alphas for the various scales were : knowledge scale : 0.918 , practice scale : 0.833 , and the barriers scale : 0.795 .
cronbach s coefficient alpha measures internal consistency of a scale.20 the instrument was administered to women that met the inclusion criteria .
the interviewers were professional female nurses who could speak the fante language who were trained to assist with the household data collection .
the instrument had predetermined answers or options for respondents to choose from , and few respondents chose other .
the instrument was administered in the local language to the study participants in their homes .
the participants were divided into two groups based on whether they had knowledge or lacked knowledge of cervical cancer .
those who lacked knowledge were taught onsite , to enable them to continue participating in the study .
an educational pamphlet developed by the ministry of health was used to educate those who lacked understanding about the disease and screening facilities available .
group 1 included 98% ( 384 ) of the women who did not have correct understanding of cervical cancer screening and lacked knowledge , and group 2 included 2% ( eight ) women who had correct understanding of this topic .
ethically , group 1 participants benefitted from the study through the knowledge gained after they were taught about the disease .
it is important to mention that the responses provided by group 1 participants were hypothetical as opposed to real life experiences .
data were analyzed with spss software ( v19.0 ; ibm corporation , armonk , ny , usa ) .
descriptive and inferential statistics such as percentages , chi - square test , and factor analysis were used to determine the nature of the problem . ethical approval for the study
permission was sought from community leaders and informed consent obtained from the study participant before embarking on data collection .
participants aged 17 years and below were asked to sign the assent form ( this is a form signed by all children 17 years and below participating in research and is sought in addition to parental consent ) .
this was to protect the rights of the subjects involved in the study and ensured a high level of integrity in the research process .
according to the 2010 population and housing census statistics , elmina has a total female population of 20,305.15 the target population for this study included women who are 1074 years and are sexually active .
although screening is not recommended for 10-year - olds , they were included in the study as we were testing their knowledge of risk factors for cervical cancer ; if they were knowledgeable on the subject , the likelihood of them seeking cervical screening at the appropriate time might be greater .
the women were residents of elmina who were available at the time of data collection . the sample excluded women who normally do not reside in elmina and those who were mentally challenged .
the criteria for determining the sample size for this study was based on the purpose of the study , size of the population , level of precision , the level of confidence or risk , and the degree of variability in the attributes being measured.19
random sampling is a form of probability sampling technique where each unit of the population has an equal chance of inclusion in the sample.20 based on the 2010 census data , elmina has a total of 15 communities . using the ballot approach , five communities ( bronyibima , bantoma , elmina traditional , pershie , and tetterkessimu )
second , the probability proportionate to size approach was employed in selecting the households within each community . in order to select the study participants within the households in each community , a coin was tossed and the direction where the head pointed was used to select the first household .
it was expected that at least two - thirds of those households would have women that met the inclusion criteria .
maps were available delineating the geographical area for the study and indicating major roads as well as individual households .
recruitment of subjects was conducted at churches , community centers , health centers , and schools by word of mouth and on the local radio . in order to get women who fell within the inclusion criteria to participate in the study at the household level
, interviewers inquired from heads of households if they had such women in their households .
data were collected from women who were available at the time of data collection . for those who had either gone to work or
were not available , effort was made to obtain data from them at a later date ( early in the morning or in the evening when they were at home ) .
a structured interview schedule was used to collect relevant data for the study and was adopted from that used by mupepi et al.21 the structured interview schedule offered a closed set of responses from which the respondents could choose .
the structured interview schedule identified the sociodemographic characteristics of respondents , their knowledge and practice of cervical cancer screening , and the barriers toward cervical cancer screening .
the instrument was pre - tested among 20 women in a nearby community in order to check adequacy of the questions in terms of wording , clarity , and ambiguity.20 to ensure face validity and content validity , the questions were constructed congruently with the specific research questions and the literature review .
cronbach s coefficient alphas for the various scales were : knowledge scale : 0.918 , practice scale : 0.833 , and the barriers scale : 0.795 .
cronbach s coefficient alpha measures internal consistency of a scale.20 the instrument was administered to women that met the inclusion criteria .
the interviewers were professional female nurses who could speak the fante language who were trained to assist with the household data collection .
the instrument had predetermined answers or options for respondents to choose from , and few respondents chose other .
the instrument was administered in the local language to the study participants in their homes .
the participants were divided into two groups based on whether they had knowledge or lacked knowledge of cervical cancer .
those who lacked knowledge were taught onsite , to enable them to continue participating in the study .
an educational pamphlet developed by the ministry of health was used to educate those who lacked understanding about the disease and screening facilities available .
group 1 included 98% ( 384 ) of the women who did not have correct understanding of cervical cancer screening and lacked knowledge , and group 2 included 2% ( eight ) women who had correct understanding of this topic .
ethically , group 1 participants benefitted from the study through the knowledge gained after they were taught about the disease .
it is important to mention that the responses provided by group 1 participants were hypothetical as opposed to real life experiences .
data were analyzed with spss software ( v19.0 ; ibm corporation , armonk , ny , usa ) .
descriptive and inferential statistics such as percentages , chi - square test , and factor analysis were used to determine the nature of the problem .
ethical approval for the study was obtained from the institutional review board of the university of cape coast .
permission was sought from community leaders and informed consent obtained from the study participant before embarking on data collection .
participants aged 17 years and below were asked to sign the assent form ( this is a form signed by all children 17 years and below participating in research and is sought in addition to parental consent ) .
this was to protect the rights of the subjects involved in the study and ensured a high level of integrity in the research process .
thirty - two point seven percent of the women were aged 2029 years and 107 ( 27.3% ) were aged 3039 years .
this means that the majority of the respondents were still within the reproductive age group . in terms of their marital status ,
41% of the respondents were married , 22% cohabited , 7% widowed , and 6% divorced .
most of the respondents resided at elmina traditional and bronyibima , with the most dominant tribe among them being fante ( 87.0% ) .
there were also other ethnic groups , including ga , ewe , gawu , and igbo .
christians and muslims constituted the majority of the women with 87% and 12% , respectively .
although 70 ( 17.9% ) of the respondents were formally uneducated , 170 ( 43.4% ) and eleven ( 2.8% ) had acquired junior high school or middle school education and university degrees , respectively .
a significant number of them had also obtained primary , senior high school , and college education .
about 80% of them reported that they were self - employed , while the others were either unemployed or worked in the public sector .
table 1 shows that 225 ( 57.4% ) of the respondents earned below the current national monthly income of gh157.00 ( us$50 ) as their total household income , while 108 ( 27.6% ) earned gh157200 ( us$5064 ) .
the results further showed that only 1% earned at least gh901 per month for the family ( us$290 ) .
the demographic and socioeconomic characteristics of the respondents portray the peri - urban nature of the community .
more than half ( 68.4% ) of the women had never heard about cervical cancer . the majority ( 93.6% ) of the respondents
nine ( 2.3% ) indicated that being sexually active could cause this type of cancer .
in addition , nine ( 2.3% ) of the respondents reported that having multiple sexual partners could result in cervical cancer , while five ( 1.3% ) identified that having a sex partner who had other partners might be responsible for cervical cancer .
however , none of the respondents identified cigarette smoking and tobacco chewing as possible risk factors in cervical cancer infection . out of the 392 respondents , only 23 ( 5.9% ) knew that cancer of the cervix could be transmitted through sex , while six ( 1.5% ) disagreed .
about 93% of the respondents had no knowledge of the mode of transmission of this disease .
with regard to whether cervical cancer could be treated and prevented , 92% of the respondents lacked knowledge .
the overwhelming majority ( 384 ; 97.7% ) of the respondents had never heard about the pap smear test .
however , eight ( 2% ) of the respondents had a correct understanding of pap smears . of the respondents who had undergone the pap smear test in the study ,
the three respondents who had had a pap smear test reported that they were referred by their health care providers .
other reasons that emerged for seeking a pap smear test included fear of cervical cancer and messages from radio campaigns .
the results suggest that none of the respondents had voluntarily availed themselves for this test .
the main barriers identified by respondents for not seeking pap smear tests were institutional and personal , as shown in table 2 .
these were lack of screening sites , screening sites being too far away , limited information on cervical cancer , and absence of health education programs .
the personal factors were lack of knowledge about the pap smear test and the facilities where it can be carried out .
this is because these two barriers had eigenvalues greater than 2 and had accounted for 16.25% and 12.73% of the total variation in the data , respectively .
specifically , items such as the screening sites are too far from where i live and there is limited information on cervical cancer in the community were dominant in the institutional barriers to the pap smear test among the respondents .
with regard to the personal barriers , the respondents lacked adequate knowledge about the test and where it could be done .
similarly , negative beliefs , social , and negative misconception barriers collectively explained about 47% of the total variation .
the negative beliefs identified by the majority of the respondents were that the pap smear test was embarrassing and painful .
the social barrier identified was that religion and cultural values deterred women from seeking the pap smear test .
in addition , women s partners not allowing their spouse to seek the pap smear was identified as a social barrier .
the negative misconceptions identified were that women did not feel at risk and therefore felt no need for pap screening and also those that reported not being sexually active felt no need for the pap test .
the financial barriers identified included the inability to afford the cost of the test since it is not covered by the national health insurance scheme .
the study revealed that not having pap smear tests had significant associations with all seven barriers at the 5% significance level as shown in table 3 .
this confirmed the negative implications of these barriers on respondents decision not to undergo a pap smear test for cervical cancer . confirming the results from the factor analysis , the chi - square test also revealed that institutional barriers were the main barriers to seeking a pap smear test , followed by personal barriers , since they had the highest chi - square values of 28.965 ( df = 4 ; p=0.000 ) and 26.055 ( df = 5 ; p=0.000 ) , respectively .
the fantes belong to a major ethnic group : the akan in ghana . a significant proportion ( 341 ; 87.1% ) were christians , followed by 47 ( 12% ) muslims .
this supports the claim that 71.2% of ghanaians are christians , with 17.6% being muslims.22 a greater proportion ( 128 ; 32.7% ) of the participants fell within the 2029 years age group .
this is consistent with the findings of the ghana demographic and health survey 2008 , which suggested that more than half of ghanaian women are under the age of 30 years.16 this age structure shows that the sample consisted of a young population , which could have high fertility .
this calls for the provision of reproductive health services to meet their sexual and reproductive health needs .
knowledge of women on cervical cancer and the pap smear test are critical in cervical cancer prevention strategies .
the results of this study shows that a great proportion ( 68.4% ) of the sampled population had never heard of cervical cancer .
this finding is consistent with other research , which reported a lack of knowledge about cervical cancer among women.21,27,28 education on cervical screening through the mass media and health talks in delivering health care are imperative to informing women about cervical cancer and the facilities available for them .
opportunistic screening in health facilities could be encouraged to improve screening uptake , especially in women within the lower socioeconomic groups.1330 in this study , the majority of the respondents ( 93.6% ) lacked knowledge of risk factors for cervical cancer .
previous studies have cited lack of knowledge and awareness about the risk factors of cervical cancer as important factors impacting screening uptake.3133,45 were et al33 reported a significant association between perceived risk of cervical cancer and having the intent for cervical screening . a possible explanation for this result might be the low public awareness of cervical cancer in ghana.4 in addition , the status of women in the ghanaian society could affect their pattern of seeking preventive health services .
in most households , women are not actively involved in decision making and they might not be in a position to have sufficient financial resources to engage in appropriate health promotion interventions such as cervical screening ; this generally deprives ghanaian woman of equity , dignity , and equality.34 it is evident that information about cervical cancer needs to be made available to women through mass campaigns about the disease , especially specific preventive measures and the screening facilities available.2436 nine ( 2.3% ) participants indicated that being sexually active and having multiple sexual partners could predispose an individual to cervical cancer .
this finding is consistent with several previous studies2535 that reported association of hpv and cervical cancer to sexual activity.2137 a significant association has been found between having multiple sex partners and perceived risk of cervical cancer.2633 according to the who , cervical cancer is caused by hpv , which is a sexually transmitted infection and mostly affects sexually active men and women.3 however , in the current study , only 23 ( 5.9% ) knew that cancer of the cervix could be transmitted sexually .
this implies that a greater proportion of sexually active women might acquire hpv through sex without them knowing the source of the infection .
this is consistent with the findings of previous studies,429 which reported awareness about the pap smear to be low among samples of nigerian , zimbabwean , and ghanaian women . in the present study ,
only 2% had correct understanding of pap smears , ie , they could describe the test and identify facilities where one can obtain such services .
this affirmed the findings of paolino and arrossi,38 in which a significant proportion ( 49% ) of those who had been screened had inadequate knowledge about pap smears . in ghana and other developing countries ,
there is poor institutional framework to promote screening.13 this is different from industrialized nations , which have largely succeeded in implementing successful programs.5 in this study , 92% of the respondents indicated that cervical cancer can not be treated and prevented .
this is consistent with the findings of eze et al,25 who reported that few women had knowledge on the prevention of cervical cancer .
meanwhile , in high income countries , availability of information on preventive strategies and treatment modalities has decreased the mortality of cancer of the cervix.3940 despite strong evidence that the pap smear test is an appropriate method for increasing early intervention opportunities and decreasing the incidence and mortality associated with cervical cancer,3 many women in low
middle income countries have not availed themselves for screening . in this study , out of the 392 respondents , only three ( 0.8% ) had had the pap smear test .
studies conducted earlier have reported low rates of pap smear screening among women.2141 a possible explanation is that women will engage in cervical screening if they are well - informed about it and the enabling factors are present to facilitate effective screening uptake .
chirenje et al42 indicated that in zimbabwe , more than 95% of health care institutions had basic infrastructure to conduct cervical screening , but absence of clear policy , procedures , and competent cytotechnicians had affected utilization of cervical screening facilities . in ghana , a lack of policy on mass screening could be contributing to low screening rates .
earlier works have reported that referral and recommendations by a doctor are strong motivators for participating in cervical cancer screening programs.23,43,44 while these are important factors , fear of knowing one had cervical cancer , being offering a pap smear , and then obtaining an abnormal test result discouraged women from utilizing screening tests in kenya , estonia , and qatar.3346 the current study was unable to identify the fact that women participated in cervical screening as part of routine visits to health facilities and that their husbands might encourage them as has been reported in previous studies.3547 interesting findings in a study conducted among men in an urban area in ghana revealed that most men expressed their willingness to provide spousal support for cervical screening if they had more information about the disease and the screening methods.48 several factors could deter women from adopting appropriate health - seeking behaviors .
the majority 348 ( 89.4% ) of the respondents indicated that their past vaginal examinations had been uncomfortable .
painful screening experiences and embarrassment with genital examination have been cited as factors that inhibit participation.3344 in an earlier study , waller et al49 identified fear of pain , feelings of embarrassment , unknown outcome of screening , difficulty scheduling an appointment , not being sexually active , and not trusting the test as barriers to cervical screening .
three hundred and eighty - seven ( 99.4% ) of the respondents in this study were of the view that screening facilities were not available in the community .
the lack of access to health care , for instance , unavailability of screening sites and long distance to facilities influenced pap smear screening behavior among women.25,35,50 ezem41 and mutyaba et al51 pointed out that lack of awareness was a key factor preventing women from participating in cervical cancer screening , and in the present study , 329 ( 84.5% ) lacked knowledge about the pap smear test .
previous studies have reported similar findings.29,30,52 this study further revealed that 97% of the respondents could not afford the cost of pap smears as it is not covered by the national health insurance scheme . in the present study , institutional and personal factors were the main barriers regarding seeking pap smear tests in elmina .
these barriers could impact the health - seeking behaviors of women at the community level .
evidence suggests that inadequate information on cervical cancer screening at the community level could be an important barrier in low
middle income countries in sub - saharan africa.1 women could lack knowledge about where to access screening services.28 the personal barriers identified were that respondents lacked knowledge of screening sites and what the pap test was about .
several studies have documented a low level of awareness of cervical cancer screening in developing countries.24,25,29,41
cervical cancer screening services such as the pap smear test might be effective in detecting early precancerous lesions
. however , many women in low middle income countries may not be in a good position to access these services due to various forms of inequalities .
the majority of the women lacked knowledge about cervical cancer and the pap smear test . the respondents lacked knowledge about cervical cancer risk factors , treatment , and prevention strategies . personal and institutional barriers hindering the use of pap smear services in elmina were lack of awareness about the pap smear test , the high cost of pap smear screening , past vaginal examination being uncomfortable , and unavailability of screening facilities .
political commitment is needed to initiate culturally accepted cervical cancer screening programs and to address the numerous access barriers women encounter in order to promote their health .
community leaders , women , and politicians need to agree on a policy that will facilitate cervical screening ; pap smears should be accorded priority like other maternal and child health programs .
some of the responses are based on hypothetical experiences as opposed to real life experiences .
some of the responses are based on hypothetical experiences as opposed to real life experiences . | ### Summary:
: aimsthe aims of this study were : 1 ) to assess the level of knowledge of women about pap smear tests , 2 ) to determine the practices of women regarding pap smear tests , and 3 ) to determine the barriers to pap smear tests in elmina , ghana.methodsa cross - sectional study was conducted with 392 randomly selected sexually active females aged 1074 years using structured interview questions .
the institutional review board of the university of cape coast gave ethical approval for the study and informed consent was obtained from participants .
data were analyzed with spss software ( v19.0 ) using frequencies , chi - square test , and exploratory factor analysis.resultsthe results revealed that 68.4% had never heard about cervical cancer , 93.6% had no knowledge on the risk factors , nine ( 2.3% ) reported multiple sexual partners and being sexually active as risk factors , and 92% did not know about the prevention and treatment of cervical cancer .
the majority ( 97.7% ) had never heard of the pap smear test . only three ( 0.8% ) women out of 392 had had a pap smear test .
reasons for seeking a pap smear test included referral , fear of cervical cancer , and radio campaigns .
a significant association was found between institutional and personal barriers and having a pap smear test.conclusioncomprehensive education on cervical cancer screening and removal of access barriers are critical in reducing risk associated with the disease and promoting women s health . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: polylactide - co - glycolide ( plga ) has been extensively explored as a scaffolding material in tissue engineering applications because of its biocompatibility , biodegradability , and mechanical strength.1,2 more recently , electrospun plga fibers , because of their unique extracellular matrix mimicking microfibrous / nanofibrous structure , have shown potential for development as scaffolding systems.36 these fibrous meshes of plga ( diameter ranging from tens of nanometers to a few microns ) possess other desirable properties for scaffolding systems , such as a high aspect ratio , a highly porous structure ( 80%90% porosity ) , and good tensile strength.7,8 the varieties of plga that have improved mechanical properties are the ones with a higher content of lactic acid .
however , the higher lactic acid content leads to an increase in the hydrophobicity of the plga system , which in turn can adversely influence protein interaction and subsequent cellular behavior.913 exposure of such an extracellular matrix mimicking f ibrous scaffold to the biological environment at the site of implantation would normally result in rapid adsorption of proteins onto the surface of the scaffold .
the amount , orientation , and conformation of the adsorbed proteins is largely regulated by the surface properties of the scaffold , including surface chemistry , roughness , and charge.11,12,14 these properties together determine the wettability of the scaffold surface , hence understanding the effect of wettability ( hydrophobicity / hydrophilicity ) on protein adsorption is desirable for scaffold design .
various studies have reported that adsorption of proteins on a highly hydrophobic surface can denature the native conformation of the protein and consequently compromise bioactivity.15,16 on the other hand , highly hydrophilic surfaces can inhibit protein adsorption.17 therefore , it is now well accepted that both extremely hydrophilic and hydrophobic surfaces may not be desirable for favorable protein interaction .
rather , surfaces with moderate hydrophobicity / hydrophilicity are considered more favorable for adsorbing proteins in their natural conformation , which can be an important factor in determining cell interactions with the scaffold surface.11,12,16,18,19 therefore , it would be desirable to design a plga microfibrous scaffold that maintains the advantages of plga while providing a reduced surface hydrophobicity in order to make them more amenable as tissue engineering scaffolds . in a previous study , we reported the blending of small concentrations of the nonionic surfactant pluronic f-108 ( pf-108 ) with plga ( 85:15 ) , and demonstrated a significant reduction in the surface hydrophobicity of electrospun plga fibers while minimally compromising the thermal , mechanical , and degradation properties of plga.20,21 these studies also demonstrated that the reduction in hydrophobicity was due to surface enrichment of ethylene oxide units of pf-108 on microfibrous plga scaffolds .
further , it was also observed that the alleviation of surface hydrophobicity lead to an enhanced interaction with water throughout the mesh ( as demonstrated by water uptake and swelling studies ) . because proteins generally exist in aqueous solution under physiological conditions
, we hypothesized that increased hydrophilicity of pf-108 blended plga microfibrous meshes will increase the possibility of interaction between water - solubilized protein molecules and microfiber surfaces .
this can , in turn , influence the adsorbed protein in terms of its amount , secondary structure , and consequently its function .
therefore , this study was conducted to understand the influence of hydrophilization of plga microfibers on the adsorption behavior , secondary structure , and function of adsorbed proteins .
bovine serum albumin ( 99% purity ) , and chicken egg white lysozyme ( 99% purity ) were obtained from bangalore genei , india , and used as received .
plga ( 85:15 ) with a molecular weight of 45,00070,000 , and pf-108 ( 82.2% ethylene oxide and 17.8% propylene oxide ) with a molecular weight of 14,600 were obtained from sigma aldrich , st louis , mo .
tetrahydrofuran and dimethylformamide ( solvents of high - pressure liquid chromatography grade ) used for electrospinning were purchased from merck india ltd ( mumbai , india ) .
protein estimation was conducted colorimetrically using a bicinchoninic acid assay kit procured from thermo scientific ( rockford , il ) and lysozyme activity was quantified using the lysozyme assay kit procured from sigma - aldrich .
the plga microfibrous meshes were fabricated by electrospinning as reported previously.20 the electrospinning apparatus that was used for fabricating plga microfibers consisted of a high voltage power supply unit ( glassman high voltage inc , high bridge , nj ) , an adjustable rotatory mandrel ( length 12 cm and diameter 7.5 cm ) that served as a substrate for collection of fibers , and a syringe pump ( harvard apparatus , holliston , ma ) that enabled pumping of the polymer solution .
briefly , a 22% w / v polymer solution ( pure plga or plga blended with 0.5%2.0% w / v of pf-108 ) prepared in tetrahydrofuran and dimethylformamide in a 3:1 ratio was used for electrospinning .
the parameters used for electrospinning were as follows : flow rate of 0.5 ml / hour , electrospinning distance of 29 cm ( distance between the tip of the needle [ internal diameter = 0.394 mm ] and the collector mandrel ) , and the voltage applied was 1.2 kv / cm .
the plga solution when electrospun using the aforementioned parameters lead to the fabrication of microfibers that were deposited / collected on the rotating mandrel ( 300 rpm ) .
the fabricated nonwoven microfibrous mesh was lyophilized for 48 hours and used for further experiments . for convenience ,
the following acronyms were used to represent the microfiber samples studied : pf-0.0 for pure plga microfibers , pf-0.5 for 0.5% pf-108 blended plga microfibers , pf-1.0 for 1.0% pf-108 blended plga microfibers , pf-1.5 for 1.5% pf-108 blended plga microfibers , and pf-2.0 for 2.0% pf-108 blended plga microfibers .
an fei quanta 200 scanning electron microscope ( sem ) was used to characterize the surface morphology and diameter of the electrospun microfibers .
microfibrous meshes were lyophilized for 24 hours and sputter - coated with gold prior to sem analysis .
sem analysis was performed at a working distance of 10 mm and an accelerating voltage of 20 kv .
the fiber diameters were measured using an indigenously developed algorithm ( software ) that estimated diameters using gray - scale images generated from the sem . for each sample ,
three zones of view were imaged and analyzed using the software . for each zone ,
more than 50 measurements were recorded and measurements from all the three zones were averaged to arrive at average diameter values of blended and unblended microfiber meshes . freshly prepared solutions of bovine serum albumin ( bsa , 5% w / v ) and lysozyme ( 5% w / v ) in phosphate - buffered saline ( ph 7.4 ) were used for adsorption .
prewetted plga microfiber meshes ( 30 minutes in double distilled water ) were immersed in protein solution for 30 minutes .
after 30 minutes , the protein - adsorbed plga microfiber meshes were gently washed with deionized water three times .
all microfibrous meshes ( freshly prepared and protein adsorbed ) were frozen at 20c for 24 hours prior to lyophilization .
frozen samples were then lyophilized at 50c and 110 mb ( 1.59 psi ) pressure for a duration of 72 hours using a lyophilizer ( freeze dryer alpha 14 ld plus ; martin christ gefriertrocknungsanlagen gmbh , osterode am harz , germany ) .
the lyophilized samples were used for protein release and fourier transform infrared ( ftir ) spectroscopy studies . for these studies , 1 1 cm samples of protein - adsorbed plga microf iber meshes ( pf-0.0 , pf-0.5 , pf-1.5 , and pf-2.0 ) were suspended in 1 ml of phosphate - buffered saline at ph 7.4 .
culture tubes containing the suspended microfiber samples were incubated at 37c in an orbital shaker at 50 rpm . at predetermined time points ( 2 , 8 , and 24 hours )
1 ml of phosphate - buffered saline containing released protein was aspirated and the culture tubes were replenished with a similar amount of fresh phosphate - buffered saline .
the concentration of the released protein in the aspirated phosphate - buffered saline was quantified using the bicinchoninic acid assay.22 for this , the protein - containing samples were incubated with bicinchoninic acid reagents for 60 minutes and the samples were prepared as per the pierce ( thermo ) protocol for ultraviolet analysis .
the absorption values for the prepared samples were recorded at a wavelength of 595 nm using an ultraviolet - visible spectrophotometer ( thermo electron corp , waltham , ma ) .
the concentration of the protein at the respective time points was then calculated from reference plots of known concentrations of bsa and lysozyme ( 101000 g / ml ) .
all experiments were performed in triplicate . for the secondary structure analysis of the adsorbed proteins ,
ftir spectroscopy was used.23 ftir spectroscopy can process a variety of protein samples , such as solubilized proteins,24,25 proteins adsorbed on surfaces,2629 and encapsulated proteins,30 and hence can be a useful tool for the characterization of proteins associated with scaffolds in tissue engineering applications . further
, mathematical methods such as second derivative ( qualitative)31 and deconvolution ( quantitative)32,33 can be applied to estimate the secondary structure of proteins adsorbed on biomaterial surfaces using its ftir spectra .
hence , ftir - based structural analysis was used in this study to understand the interactions between proteins and hydrophilized plga microfiber surfaces .
attenuated total reflectance ftir spectroscopy was conducted using a bruker ( tensor 27 ) ftir spectrometer .
control of the instrument as well as collection and primary analysis of data was accomplished using inbuilt opus software .
prior to data acquisition , the optical bench was purged using dry n2 to minimize external interference . for each run , a total of 500 scans were collected at a resolution of 4 cm . in order to minimize the possibility of error , the ftir spectra of all plga microfiber mesh samples ( with and without adsorbed protein ) were recorded at least three times from both sides . each recorded spectrum was corrected for background ( atmospheric components ) , and the spectrum for plga microfiber meshes without adsorbed protein ( pure plga meshes ) was used as a control for protein - adsorbed microfiber meshes . in order to obtain the amide absorbance , the spectra of protein - adsorbed microfiber meshes were subtracted from the spectra of pure plga meshes . for powder samples (
pure bsa and lysozyme ) spectra were recorded with 2 mg samples in 200 mg kbr as a compressed pellet .
all samples used were lyophilized prior to ftir analysis and used immediately after lyophilization to reduce the possibility of surface contamination / moisture adsorption .
the ftir spectra of bsa and lysozyme consist of multiple signature peaks for secondary protein structure including amide i ( 15001600 cm ) , ii ( 14801575 cm ) , and iii ( 12291301 cm ) .
however , in this study we used only the amide i adsorption region because it is majorly governed by co ( 70%85% ) and c - n groups on the protein backbone . to determine the secondary structure of adsorbed proteins , the sum of gaussian curve to amide i region ( ie , 15001600 cm )
the curve fitting was performed using a previously reported method in which the authors have presumed 56 gaussian peaks.23,24,30 therefore , in this study there was a presumption of 56 gaussian peaks , with each peak being ascribed to a segment assuming a distinct secondary structure : 16891682 cm -structure ; 16821661 cm turns ; 16611647 cm
all possible gaussian peaks were computed using a nonlinear least square iterative curve fitting method ( origin 6.0 ) . in all cases ,
the secondary structures of bsa and lysozyme were quantified at three different stages : first , when they were in the nonadsorbed state ( ie , free protein powder ) ; second , adsorbed on pf-108 blended and unblended plga microfibrous meshes ; and third , when they were released from the plga microfiber meshes . in all cases
lysozyme causes hydrolysis of 1,4-beta - linkages between n - acetylmuramic acid and n - acetyl - d - glucosamine residues present in the peptidoglycan layer of bacterial cell walls .
hence , a bacteria ( micrococcus lysodeikticus ) with an intact cell wall was used as the substrate for the lysozyme bioactivity assay .
the assay was performed using a previously reported protocol.34,35 briefly , a 0.01% ( w / v ) suspension of m. lysodeikticus was prepared in potassium phosphate buffer ( 0.1 m , ph 6.24 ) .
a 100 l aliquot of released lysozyme solution was added to 2.5 ml of the cell suspension .
the turbidity of the cell suspension ( cell lysis causes a change in turbidity of the cell suspension and this change in turbidity was measured ) was estimated from absorption values of nonlysed cells recorded at 450 nm using an ultraviolet - visible spectrophotometer .
absorbance values were recorded for a total duration of 5 minutes ( at intervals of one minute ) .
lysozyme activity was calculated from the slope of the linear region of the absorbance at 450 nm versus time curve .
specific lysozyme activity was determined in terms of units / ml of released phosphate - buffered saline based on the fact that , for the conditions employed , one unit of enzyme activity reduced the absorbance value by 0.001/minute .
statistical analysis was performed using analysis of variance to test for significant differences between the means of data sets , whereas multiple comparisons of sample means were performed using the tukey - kramer multiple comparison test .
the plga microfibrous meshes were fabricated by electrospinning as reported previously.20 the electrospinning apparatus that was used for fabricating plga microfibers consisted of a high voltage power supply unit ( glassman high voltage inc , high bridge , nj ) , an adjustable rotatory mandrel ( length 12 cm and diameter 7.5 cm ) that served as a substrate for collection of fibers , and a syringe pump ( harvard apparatus , holliston , ma ) that enabled pumping of the polymer solution .
briefly , a 22% w / v polymer solution ( pure plga or plga blended with 0.5%2.0% w / v of pf-108 ) prepared in tetrahydrofuran and dimethylformamide in a 3:1 ratio was used for electrospinning .
the parameters used for electrospinning were as follows : flow rate of 0.5 ml / hour , electrospinning distance of 29 cm ( distance between the tip of the needle [ internal diameter = 0.394 mm ] and the collector mandrel ) , and the voltage applied was 1.2 kv / cm .
the plga solution when electrospun using the aforementioned parameters lead to the fabrication of microfibers that were deposited / collected on the rotating mandrel ( 300 rpm ) .
the fabricated nonwoven microfibrous mesh was lyophilized for 48 hours and used for further experiments . for convenience ,
the following acronyms were used to represent the microfiber samples studied : pf-0.0 for pure plga microfibers , pf-0.5 for 0.5% pf-108 blended plga microfibers , pf-1.0 for 1.0% pf-108 blended plga microfibers , pf-1.5 for 1.5% pf-108 blended plga microfibers , and pf-2.0 for 2.0% pf-108 blended plga microfibers .
an fei quanta 200 scanning electron microscope ( sem ) was used to characterize the surface morphology and diameter of the electrospun microfibers .
microfibrous meshes were lyophilized for 24 hours and sputter - coated with gold prior to sem analysis .
sem analysis was performed at a working distance of 10 mm and an accelerating voltage of 20 kv .
the fiber diameters were measured using an indigenously developed algorithm ( software ) that estimated diameters using gray - scale images generated from the sem . for each sample ,
three zones of view were imaged and analyzed using the software . for each zone ,
more than 50 measurements were recorded and measurements from all the three zones were averaged to arrive at average diameter values of blended and unblended microfiber meshes .
freshly prepared solutions of bovine serum albumin ( bsa , 5% w / v ) and lysozyme ( 5% w / v ) in phosphate - buffered saline ( ph 7.4 ) were used for adsorption .
prewetted plga microfiber meshes ( 30 minutes in double distilled water ) were immersed in protein solution for 30 minutes .
after 30 minutes , the protein - adsorbed plga microfiber meshes were gently washed with deionized water three times .
all microfibrous meshes ( freshly prepared and protein adsorbed ) were frozen at 20c for 24 hours prior to lyophilization .
frozen samples were then lyophilized at 50c and 110 mb ( 1.59 psi ) pressure for a duration of 72 hours using a lyophilizer ( freeze dryer alpha 14 ld plus ; martin christ gefriertrocknungsanlagen gmbh , osterode am harz , germany ) .
the lyophilized samples were used for protein release and fourier transform infrared ( ftir ) spectroscopy studies .
for these studies , 1 1 cm samples of protein - adsorbed plga microf iber meshes ( pf-0.0 , pf-0.5 , pf-1.5 , and pf-2.0 ) were suspended in 1 ml of phosphate - buffered saline at ph 7.4 .
culture tubes containing the suspended microfiber samples were incubated at 37c in an orbital shaker at 50 rpm . at predetermined time points ( 2 , 8 , and 24 hours )
1 ml of phosphate - buffered saline containing released protein was aspirated and the culture tubes were replenished with a similar amount of fresh phosphate - buffered saline .
the concentration of the released protein in the aspirated phosphate - buffered saline was quantified using the bicinchoninic acid assay.22 for this , the protein - containing samples were incubated with bicinchoninic acid reagents for 60 minutes and the samples were prepared as per the pierce ( thermo ) protocol for ultraviolet analysis .
the absorption values for the prepared samples were recorded at a wavelength of 595 nm using an ultraviolet - visible spectrophotometer ( thermo electron corp , waltham , ma ) .
the concentration of the protein at the respective time points was then calculated from reference plots of known concentrations of bsa and lysozyme ( 101000 g / ml ) .
for the secondary structure analysis of the adsorbed proteins , ftir spectroscopy was used.23 ftir spectroscopy can process a variety of protein samples , such as solubilized proteins,24,25 proteins adsorbed on surfaces,2629 and encapsulated proteins,30 and hence can be a useful tool for the characterization of proteins associated with scaffolds in tissue engineering applications .
further , mathematical methods such as second derivative ( qualitative)31 and deconvolution ( quantitative)32,33 can be applied to estimate the secondary structure of proteins adsorbed on biomaterial surfaces using its ftir spectra .
hence , ftir - based structural analysis was used in this study to understand the interactions between proteins and hydrophilized plga microfiber surfaces .
attenuated total reflectance ftir spectroscopy was conducted using a bruker ( tensor 27 ) ftir spectrometer .
control of the instrument as well as collection and primary analysis of data was accomplished using inbuilt opus software .
prior to data acquisition , the optical bench was purged using dry n2 to minimize external interference . for each run , a total of 500 scans were collected at a resolution of 4 cm . in order to minimize the possibility of error , the ftir spectra of all plga microfiber mesh samples ( with and without adsorbed protein ) were recorded at least three times from both sides .
each recorded spectrum was corrected for background ( atmospheric components ) , and the spectrum for plga microfiber meshes without adsorbed protein ( pure plga meshes ) was used as a control for protein - adsorbed microfiber meshes . in order to obtain the amide absorbance , the spectra of protein - adsorbed microfiber meshes were subtracted from the spectra of pure plga meshes . for powder samples (
pure bsa and lysozyme ) spectra were recorded with 2 mg samples in 200 mg kbr as a compressed pellet .
all samples used were lyophilized prior to ftir analysis and used immediately after lyophilization to reduce the possibility of surface contamination / moisture adsorption .
the ftir spectra of bsa and lysozyme consist of multiple signature peaks for secondary protein structure including amide i ( 15001600 cm ) , ii ( 14801575 cm ) , and iii ( 12291301 cm ) .
however , in this study we used only the amide i adsorption region because it is majorly governed by co ( 70%85% ) and c - n groups on the protein backbone . to determine the secondary structure of adsorbed proteins , the sum of gaussian curve to amide i region ( ie , 15001600 cm )
the curve fitting was performed using a previously reported method in which the authors have presumed 56 gaussian peaks.23,24,30 therefore , in this study there was a presumption of 56 gaussian peaks , with each peak being ascribed to a segment assuming a distinct secondary structure : 16891682 cm -structure ; 16821661 cm turns ; 16611647 cm
all possible gaussian peaks were computed using a nonlinear least square iterative curve fitting method ( origin 6.0 ) . in all cases , a linear base line was fitted .
the secondary structures of bsa and lysozyme were quantified at three different stages : first , when they were in the nonadsorbed state ( ie , free protein powder ) ; second , adsorbed on pf-108 blended and unblended plga microfibrous meshes ; and third , when they were released from the plga microfiber meshes . in all cases ,
lysozyme causes hydrolysis of 1,4-beta - linkages between n - acetylmuramic acid and n - acetyl - d - glucosamine residues present in the peptidoglycan layer of bacterial cell walls .
hence , a bacteria ( micrococcus lysodeikticus ) with an intact cell wall was used as the substrate for the lysozyme bioactivity assay .
the assay was performed using a previously reported protocol.34,35 briefly , a 0.01% ( w / v ) suspension of m. lysodeikticus was prepared in potassium phosphate buffer ( 0.1 m , ph 6.24 ) .
a 100 l aliquot of released lysozyme solution was added to 2.5 ml of the cell suspension .
the turbidity of the cell suspension ( cell lysis causes a change in turbidity of the cell suspension and this change in turbidity was measured ) was estimated from absorption values of nonlysed cells recorded at 450 nm using an ultraviolet - visible spectrophotometer .
absorbance values were recorded for a total duration of 5 minutes ( at intervals of one minute ) .
lysozyme activity was calculated from the slope of the linear region of the absorbance at 450 nm versus time curve .
specific lysozyme activity was determined in terms of units / ml of released phosphate - buffered saline based on the fact that , for the conditions employed , one unit of enzyme activity reduced the absorbance value by 0.001/minute .
statistical analysis was performed using analysis of variance to test for significant differences between the means of data sets , whereas multiple comparisons of sample means were performed using the tukey - kramer multiple comparison test .
plga microfibrous meshes fabricated using the electrospinning technique were analyzed for their morphology using sem .
the sem micrographs ( figure 1 ) of pf-108 blended and unblended plga microfiber mesh samples show that the fibers in both samples had a random orientation , nonwoven arrangement , porous structure , and smooth morphology .
the fiber diameter ranged from 200 nm to 1000 nm ( figure 1 ) with an average diameter of 800 nm . in a previous study , 0.5%2.0% pf-108 blended plga microf iber meshes were thoroughly characterized for surface properties.20,21 the results of that study demonstrated that , for pf-108 ( 0.5%2.0% ) blended plga samples , the contact angle of the microfiber meshes decreased significantly from 120 to 10. the drop in contact angle demonstrated the improved hydrophilicity of plga microfibrous meshes as a consequence of blending with pf-108 .
the surface hydrophilicity of the pf-108 blended plga microfiber meshes was further corroborated using x - ray photoelectron spectroscopy analysis wherein significant enrichment of pf-108 ( 25%33% ) on plga microfiber surfaces was demonstrated .
these results confirmed the presence of pf-108 on the surface of the blended plga microfiber meshes as well as the extent to which it was present on the surface .
however , the surface coverage of pf-108 on plga microfibers was partial , indicating that the pf-108 blended plga microfibers probably had a distribution of hydrophilic environments ( pf-108 ) and hydrophobic environments ( plga ) on their surface ( figure 4 ) .
this distribution of hydrophilic and hydrophobic environments on the surface of plga microfibers makes its surface moderately hydrophobic ( as against highly hydrophobic for pure plga microfibers ) , which was hypothesized to be the reason for rendering the surface relatively more favorable for protein interaction . to understand
the influence of improved surface hydrophilicity ( moderate hydrophobicity ) of blended plga microfibers on protein interaction , protein adsorption and release studies were performed as the first set of studies .
the release of adsorbed bsa and lysozyme from pf-108 blended and unblended plga meshes were quantified for three different time points , ie , at 2 , 8 , and 24 hours .
figures 2 and 3 are plots of the amount of protein released ( g / ml ) as a function of time for all the sample types ( pf-0.0 , pf-0.5 , pf-1.0 , pf-1.5 , and pf-2.0 ) .
figure 2 demonstrates that the amount of bsa released at 2 hours from all pf-108 ( 0.5%2.0% ) blended plga meshes was more than two times that of the bsa released from unblended plga meshes .
however , no significant difference in amount of released bsa ( 5565 g ) was observed amongst the blended samples at the 2-hour time point . in all samples ( blended and unblended ) , approximately 95% of adsorbed bsa
was released during the first 2 hours , and no significant release was observed at the 8-hour and 24-hour time points .
similar results were obtained when lysozyme was used as a model protein for adsorption studies ( figure 3 ) . except for the pf-0.5
blended meshes , all other pf-108 blended plga meshes ( pf-1.0 , pf-1.5 , and pf-2.0 ) showed close to two times the amount of lysozyme released ( 90% increase ) as compared with the unblended plga microfiber meshes . like bsa , lysozyme also showed a burst release ( about 95% of total adsorbed lysozyme ) during the first two hours followed by marginal release of lysozyme at the 8-hour and 24-hour time points .
interestingly , the amount of lysozyme adsorbed ( as quantified by the release study ) was significantly higher than the amount of bsa released for both unblended and blended plga microfiber meshes . for the unblended samples , the amount of protein released at the 2-hour time point was 26 g / ml for bsa and 250 g / ml for lysozyme , indicating a near 10-fold increase in the amount of released protein for lysozyme , whereas for the blended samples the released protein ranged from 55 to 65 g / ml for bsa and from 350 to 450 g / ml for lysozyme , indicating a 79-fold increase in the amount of released lysozyme .
this indicates that the increase in amount of released lysozyme was irrespective of the presence or absence of pf-108 .
the possible reason for a higher amount of released lysozyme could be its relatively smaller size ( 14.5 kda for lysozyme and 66 kda for bsa ) , which probably enabled adsorption of more protein per unit area of the microfibrous surface .
irrespective of the protein used , the pf-108 blended samples showed a significantly higher protein release as compared with the unblended plga samples .
this could be attributed to the change in chemical composition and consequent surface hydrophilicity of the blended microfibers .
pf-108 is a block copolymer of two different monomers , ie , ethylene glycol ( eo ) and propylene glycol ( po ) and was chosen because it contains 82.2% of eo units and 17.8% of po units , which makes it hydrophilic in nature .
previous literature has shown that when pf-108 was blended with a hydrophobic polymer ( such as plga ) , conformation of pf-108 at the surface was such that the hydrophobic po units associate with hydrophobic plga and the hydrophilic eo units protrude outward ( figure 4).3638 it has also been shown that when pf-108 is present on the surface in low concentrations , the eo units arrange in a mushroom shape that enables primary and secondary adsorption of proteins ( figure 5 ) whereas at higher pf-108 concentrations , the eo units arrange in a densely packed brush - shaped structure , which leads to reduced protein adsorption on its surface ( ie , a nonfouling surface).39 in a previous study , we have demonstrated that the percentage accumulation of pf-108 on plga microfiber surfaces did not exceed 33% ( 2.0% pf-108).20 therefore , because the pf-108 coverage on the microfiber surfaces was partial , it was speculated that the eo units would take on the mushroom conformation that allowed more proteins ( primary on material surface and secondary on protein mushroom conformation ) to be adsorbed on the blended microfiber surfaces .
further , both the proteins ( bsa and lysozyme ) possess a predominantly hydrophilic external surface that can facilitate the secondary adsorption of proteins on the mushroom conformation .
taken together , the release studies ( figures 2 and 3 ) demonstrated that a change in surface composition ( hydrophilicity ) allowed for enhanced accessibility of water molecules , which eventually enabled more protein molecules to interact and adsorb on blended microfiber surfaces .
protein adsorption on biomaterial surfaces is a complex process and can involve multiple noncovalent interactions , such as van der waals , hydrophobic , and electrostatic interactions , as well as hydrogen bonding .
these noncovalent interactions are primarily governed by the protein type and surface properties of the biomaterial .
depending on the surface chemistry of the biomaterial ( hydrophilic / hydrophobic , charged / uncharged surfaces ) , proteins when adsorbed onto the biomaterial surfaces can undergo changes in conformation and/or orientation which in turn can influence its bioactivity.40 therefore , estimating the conformational change of adsorbed proteins would be desirable for designing a new biomaterial surface because the protein conformation has direct implications for biomaterial - cell interactions .
although plga - based biomaterial surfaces have been studied for their interactions with a variety of proteins,30,41,42 the pf-108 blended plga microfiber meshes have not be studied for their interactions with proteins .
therefore , in this set of experiments , proteins were studied for change in their secondary structure as a result of their interaction with blended and unblended plga microfibrous meshes .
two model proteins , bsa and lysozyme , that differed in properties , such as size , function , and secondary structure , were chosen in order to enable a better understanding of protein - fiber surface interactions .
bsa is a 66 kda abundantly available transporter protein , the crystal structure of which has not yet been determined by x - ray diffraction techniques . however , previous studies using circular dichroism spectroscopy and ftir spectroscopy have reported the secondary structure of bsa in its powdered form.30,33 these studies showed that the -helical content in the secondary structure of bsa ranged from 52% to 68% .
another strategy to arrive at the secondary structure of bsa would be to draw a parallel with the secondary structure of a sequentially ( 80% homology ) and functionally similar protein , such as human serum albumin .
therefore , one can use the known secondary structure details of human serum albumin to extrapolate it for the estimation of the secondary structure of bsa.43 in this study , we used the secondary structure information for bsa obtained using spectroscopic techniques ( -helical content 52%68% ) due to its significant overlap with the secondary structure information obtained from the human serum albumin extrapolation method ( -helical content 60%73% ) .
the second model protein used was hen egg white lysozyme , a small globular protein having a molecular weight of 14.5 kda .
the secondary structure of lysozyme as obtained from the protein data bank44 had an -helical content of 34%42% and a -sheet content of 7%12% .
in this study , deconvolution of ftir spectra was used for the determination of secondary structures of free powder , adsorbed , and released proteins.33,45 to affirm the use of a deconvolution procedure of ftir spectra for secondary structure estimation , the secondary structure of lyophilized lysozyme powder as determined using the deconvolution technique was compared with the secondary structure of lysozyme obtained from the protein data bank ( the dssp program was used to predict the secondary structure ) .
more than 20 protein data bank structures of lysozyme resolved by various techniques , including x - ray diffraction , and liquid and solid nuclear magnetic resonance spectroscopy , were selected to quantify the content of the secondary structure .
the secondary structure content obtained from both methods , ie , protein data bank and deconvolution , is listed in table 1 .
secondary structure was classified into three major categories , ie , -helices , -sheets , and random chains ( which include loops and random chains ) .
a comparison between the secondary structure content obtained from the protein data bank and deconvolution demonstrated that the percentage of -helices decreased from 34%42% for experimentally determined secondary structures to about 31% for secondary structures determined by deconvolution ( figure 6 ) .
conversely , the -sheet content increased from 7%12% for experimentally determined secondary structures to approximately 20% for secondary structures determined by deconvolution ( figure 6 ) . a probable explanation for the observed differences may be the usage of lyophilized lysozyme powder for deconvolution .
it has previously been reported that the lyophilization procedure can cause reversible changes in protein conformation and is associated with reduction in the -helical content and increase in the -sheet / random chain content.46 therefore , in the current study , reduction in -helical content and increase in -sheet content was speculated to be due to lyophilization of lysozyme powder . since the secondary structure predictions made using the deconvolution procedure were found to be approximately accurate , use of the deconvolution technique for secondary structure determination was considered to be validated .
conformation of protein structure can be of biological significance both in the adsorbed state and when released from a biomaterial surface . in the adsorbed state , proper orientation of proteins
influences cell interactions ( especially scaffolds in tissue engineering ) , whereas in the free / released state , proper conformation would enable the bioactive form of proteins .
therefore , in this study , bsa and lysozyme were characterized for their secondary structure in both the adsorbed and released states . because both the proteins were -helical proteins , a change in -helical content would be a strong indicator of change in structural conformation , and protein function as a consequence . the estimated values for -helical
content for bsa and lysozyme both in adsorbed and released states are shown in table 2 .
the secondary structure information of powdered ( free state ) bsa and lysozyme was used as a control .
as is evident from table 2 , adsorbed bsa ( on blended and unblended plga samples ) showed an increase ( 2%10% ) in -helical content when compared with powdered bsa .
this indicated that the adsorbed state of bsa had a slightly higher -helical content as compared with the free protein , irrespective of the material surface .
since the native structure of bsa has an -helical content of 52%68% , the observed -helical content in adsorbed bsa has a relatively lesser deviation from the native structure as compared with the free ( powder ) protein .
this improvement in -helical content as compared with free protein was speculated to be due to surface - mediated structural stability .
however , marginal differences in the -helical content of adsorbed bsa were observed between the pf-108 blended and unblended surfaces , except for the pf-1.5 blended sample .
this indicated , that irrespective of the material surface , the change in secondary structure of adsorbed bsa was not significantly different .
similar to the adsorbed state , the bsa released also showed an increase ( 3%7% ) in -helical content as compared with free bsa .
however , there was a small drop in the -helical content for most of the samples from the adsorbed state to the released state .
it is speculated that this reduction in -helical content was probably due to the absence of the polymeric surface .
although there was a small reduction in -helical content from the adsorbed state to the released state , the -helical content in the released state remained higher than that of nonadsorbed ( powder ) bsa .
this indicated that the released state had a relatively smaller deviation from the native state as compared with free bsa .
overall , a decreasing trend of -helical content was observed for bsa from the native state ( 52%68%)>adsorbed state ( 34%42%)>released state ( 35%39%)>powdered state ( 32% ) .
it was also observed that there was a difference in -helical content for the powdered state and the released state that in principle should have a similar -helical content .
this probably indicated that the changes in conformation that occurred during the process of adsorption were not fully reversed upon release ( ie , some changes at the secondary structure were probably maintained ) .
similar to bsa , the -helical content of lysozyme was also estimated in the adsorbed and released state .
there were no significant differences observed in the -helical content of adsorbed lysozyme for pf-108 blended and nonblended meshes .
similarly , in comparison with free lysozyme , lysozyme adsorbed on pf-108 blended and unblended plga microfibrous meshes showed marginal differences in -helical content .
the results for the released lysozyme were similar to those observed for the adsorbed lysozyme .
however , in both situations ( adsorbed and released ) the deviation in -helical content as compared with the native structure obtained from the protein data bank ( 34%42% -helix ) was very small .
the possible reason for the relatively better structural stability of lysozyme could be its smaller size .
it has been reported that an increase in protein concentration leads to a decrease in protein spreading and promoted reorganization of previously adsorbed protein molecules.47 similarly , in this study , it was observed that a higher concentration of lysozyme enabled higher densities of adsorbed lysozyme ( figure 3 ) , that probably leads to a smaller contact area per protein molecule and hence discourages spreading on the microfiber surface , whereas for bsa the large size of the protein probably enabled a higher contact area with the microfiber surface and as a consequence encouraged spreading .
it has been reported previously that spreading of bsa on biomaterial surfaces discourages further adsorption of bsa molecules , limiting the possibility of reorganization / compaction of adsorbed bsa molecules in a time - dependent manner.47 these previously reported studies support our observations of a marginal change in -helical content of adsorbed bsa ( table 2 ) , which was probably due to spreading of bsa and a relatively lesser amount of adsorbed bsa ( figure 3 ) , which was probably due to the spreading that discouraged further adsorption of bsa .
overall , the previous two studies ( figures 2 and 3 , table 2 ) demonstrated that although there was no significant change in the secondary structure of proteins when adsorbed on the blended and unblended plga microfibrous surfaces , the amount of adsorbed protein on the blended surfaces was approximately twice that of the unblended surfaces .
this indicates that surface hydrophilization of plga microfibers via blending with pf-108 enhanced protein adsorption while maintaining the secondary structure of the adsorbed protein . after confirming the ability of pf-108-modified plga microfiber surfaces to adsorb higher amounts of protein with minimal change in their secondary structure after adsorption
, a bioactivity assay was performed in order to determine if the protein adsorbed on the modified surfaces was biologically active . for these studies ,
lysozyme adsorbed on pf-108-blended and unblended plga microfiber meshes was subjected to a release assay .
the lysozyme released at variable time points ( 2 , 8 , and 24 hours ) was used for a bacterial cell lysis - based bioactivity assay .
lysozyme released from unblended plga microfiber meshes was used as a control ( to understand the effect of pure plga surface alone and for comparison with the pf-108 blended surface ) in these experiments .
figure 7 is a plot of the bioactivity of lysozyme ( units / ml ) released from 0.5%2.0% pf-108-blended and unblended plga microfiber meshes as a function of time .
after the first two hours of release , the blended samples released 226286 units of lysozyme , whereas the unblended plga samples released 183 units of lysozyme .
this observation corroborates the results of the lysozyme release study ( figure 3 ) wherein a similar trend was observed .
however , the extent of the differences observed between blended and unblended samples was greater for the release study than for the bioactivity study .
similar trends were observed at subsequent time points of 8 and 24 hours . however , the extent of the differences observed between blended and unblended samples decreased at subsequent time points , with the 2-hour time point showing the most prominent difference and the 24-hour time point showing a marginal difference .
further , when the units of lysozyme released at the 2-hour time point were converted to percentage bioactivity , it was observed that all samples ( blended and unblended ) showed more than 80%85% bioactivity . it is speculated that the minimal changes in secondary structure ( table 2 ) did not cause a significant change in percentage bioactivity of both adsorbed and released lysozyme .
therefore , this study demonstrates that the process of adsorption and release of lysozyme on pf-108 blended and unblended plga microfiber samples does not significantly compromise bioactivity .
plga microfibrous meshes fabricated using the electrospinning technique were analyzed for their morphology using sem .
the sem micrographs ( figure 1 ) of pf-108 blended and unblended plga microfiber mesh samples show that the fibers in both samples had a random orientation , nonwoven arrangement , porous structure , and smooth morphology .
the fiber diameter ranged from 200 nm to 1000 nm ( figure 1 ) with an average diameter of 800 nm . in a previous study , 0.5%2.0% pf-108 blended plga microf iber meshes were thoroughly characterized for surface properties.20,21 the results of that study demonstrated that , for pf-108 ( 0.5%2.0% ) blended plga samples , the contact angle of the microfiber meshes decreased significantly from 120 to 10. the drop in contact angle demonstrated the improved hydrophilicity of plga microfibrous meshes as a consequence of blending with pf-108 .
the surface hydrophilicity of the pf-108 blended plga microfiber meshes was further corroborated using x - ray photoelectron spectroscopy analysis wherein significant enrichment of pf-108 ( 25%33% ) on plga microfiber surfaces was demonstrated .
these results confirmed the presence of pf-108 on the surface of the blended plga microfiber meshes as well as the extent to which it was present on the surface .
however , the surface coverage of pf-108 on plga microfibers was partial , indicating that the pf-108 blended plga microfibers probably had a distribution of hydrophilic environments ( pf-108 ) and hydrophobic environments ( plga ) on their surface ( figure 4 ) .
this distribution of hydrophilic and hydrophobic environments on the surface of plga microfibers makes its surface moderately hydrophobic ( as against highly hydrophobic for pure plga microfibers ) , which was hypothesized to be the reason for rendering the surface relatively more favorable for protein interaction .
to understand the influence of improved surface hydrophilicity ( moderate hydrophobicity ) of blended plga microfibers on protein interaction , protein adsorption and release studies were performed as the first set of studies .
the release of adsorbed bsa and lysozyme from pf-108 blended and unblended plga meshes were quantified for three different time points , ie , at 2 , 8 , and 24 hours .
figures 2 and 3 are plots of the amount of protein released ( g / ml ) as a function of time for all the sample types ( pf-0.0 , pf-0.5 , pf-1.0 , pf-1.5 , and pf-2.0 ) .
figure 2 demonstrates that the amount of bsa released at 2 hours from all pf-108 ( 0.5%2.0% ) blended plga meshes was more than two times that of the bsa released from unblended plga meshes .
however , no significant difference in amount of released bsa ( 5565 g ) was observed amongst the blended samples at the 2-hour time point . in all samples ( blended and unblended ) ,
approximately 95% of adsorbed bsa was released during the first 2 hours , and no significant release was observed at the 8-hour and 24-hour time points .
similar results were obtained when lysozyme was used as a model protein for adsorption studies ( figure 3 ) . except for the pf-0.5
blended meshes , all other pf-108 blended plga meshes ( pf-1.0 , pf-1.5 , and pf-2.0 ) showed close to two times the amount of lysozyme released ( 90% increase ) as compared with the unblended plga microfiber meshes . like bsa , lysozyme also showed a burst release ( about 95% of total adsorbed lysozyme ) during the first two hours followed by marginal release of lysozyme at the 8-hour and 24-hour time points .
interestingly , the amount of lysozyme adsorbed ( as quantified by the release study ) was significantly higher than the amount of bsa released for both unblended and blended plga microfiber meshes . for the unblended samples , the amount of protein released at the 2-hour time point was 26 g / ml for bsa and 250 g / ml for lysozyme , indicating a near 10-fold increase in the amount of released protein for lysozyme , whereas for the blended samples the released protein ranged from 55 to 65 g / ml for bsa and from 350 to 450 g / ml for lysozyme , indicating a 79-fold increase in the amount of released lysozyme .
this indicates that the increase in amount of released lysozyme was irrespective of the presence or absence of pf-108 .
the possible reason for a higher amount of released lysozyme could be its relatively smaller size ( 14.5 kda for lysozyme and 66 kda for bsa ) , which probably enabled adsorption of more protein per unit area of the microfibrous surface .
irrespective of the protein used , the pf-108 blended samples showed a significantly higher protein release as compared with the unblended plga samples .
this could be attributed to the change in chemical composition and consequent surface hydrophilicity of the blended microfibers .
pf-108 is a block copolymer of two different monomers , ie , ethylene glycol ( eo ) and propylene glycol ( po ) and was chosen because it contains 82.2% of eo units and 17.8% of po units , which makes it hydrophilic in nature .
previous literature has shown that when pf-108 was blended with a hydrophobic polymer ( such as plga ) , conformation of pf-108 at the surface was such that the hydrophobic po units associate with hydrophobic plga and the hydrophilic eo units protrude outward ( figure 4).3638 it has also been shown that when pf-108 is present on the surface in low concentrations , the eo units arrange in a mushroom shape that enables primary and secondary adsorption of proteins ( figure 5 ) whereas at higher pf-108 concentrations , the eo units arrange in a densely packed brush - shaped structure , which leads to reduced protein adsorption on its surface ( ie , a nonfouling surface).39 in a previous study , we have demonstrated that the percentage accumulation of pf-108 on plga microfiber surfaces did not exceed 33% ( 2.0% pf-108).20 therefore , because the pf-108 coverage on the microfiber surfaces was partial , it was speculated that the eo units would take on the mushroom conformation that allowed more proteins ( primary on material surface and secondary on protein mushroom conformation ) to be adsorbed on the blended microfiber surfaces .
further , both the proteins ( bsa and lysozyme ) possess a predominantly hydrophilic external surface that can facilitate the secondary adsorption of proteins on the mushroom conformation . taken together , the release studies ( figures 2 and 3 ) demonstrated that a change in surface composition ( hydrophilicity ) allowed for enhanced accessibility of water molecules , which eventually enabled more protein molecules to interact and adsorb on blended microfiber surfaces .
protein adsorption on biomaterial surfaces is a complex process and can involve multiple noncovalent interactions , such as van der waals , hydrophobic , and electrostatic interactions , as well as hydrogen bonding .
these noncovalent interactions are primarily governed by the protein type and surface properties of the biomaterial .
depending on the surface chemistry of the biomaterial ( hydrophilic / hydrophobic , charged / uncharged surfaces ) , proteins when adsorbed onto the biomaterial surfaces can undergo changes in conformation and/or orientation which in turn can influence its bioactivity.40 therefore , estimating the conformational change of adsorbed proteins would be desirable for designing a new biomaterial surface because the protein conformation has direct implications for biomaterial - cell interactions .
although plga - based biomaterial surfaces have been studied for their interactions with a variety of proteins,30,41,42 the pf-108 blended plga microfiber meshes have not be studied for their interactions with proteins .
therefore , in this set of experiments , proteins were studied for change in their secondary structure as a result of their interaction with blended and unblended plga microfibrous meshes .
two model proteins , bsa and lysozyme , that differed in properties , such as size , function , and secondary structure , were chosen in order to enable a better understanding of protein - fiber surface interactions .
bsa is a 66 kda abundantly available transporter protein , the crystal structure of which has not yet been determined by x - ray diffraction techniques .
however , previous studies using circular dichroism spectroscopy and ftir spectroscopy have reported the secondary structure of bsa in its powdered form.30,33 these studies showed that the -helical content in the secondary structure of bsa ranged from 52% to 68% . another strategy to arrive at the secondary structure of bsa would be to draw a parallel with the secondary structure of a sequentially ( 80% homology ) and functionally similar protein , such as human serum albumin .
therefore , one can use the known secondary structure details of human serum albumin to extrapolate it for the estimation of the secondary structure of bsa.43 in this study , we used the secondary structure information for bsa obtained using spectroscopic techniques ( -helical content 52%68% ) due to its significant overlap with the secondary structure information obtained from the human serum albumin extrapolation method ( -helical content 60%73% ) .
the second model protein used was hen egg white lysozyme , a small globular protein having a molecular weight of 14.5 kda .
the secondary structure of lysozyme as obtained from the protein data bank44 had an -helical content of 34%42% and a -sheet content of 7%12% . in this study ,
deconvolution of ftir spectra was used for the determination of secondary structures of free powder , adsorbed , and released proteins.33,45 to affirm the use of a deconvolution procedure of ftir spectra for secondary structure estimation , the secondary structure of lyophilized lysozyme powder as determined using the deconvolution technique was compared with the secondary structure of lysozyme obtained from the protein data bank ( the dssp program was used to predict the secondary structure ) .
more than 20 protein data bank structures of lysozyme resolved by various techniques , including x - ray diffraction , and liquid and solid nuclear magnetic resonance spectroscopy , were selected to quantify the content of the secondary structure .
the secondary structure content obtained from both methods , ie , protein data bank and deconvolution , is listed in table 1 .
secondary structure was classified into three major categories , ie , -helices , -sheets , and random chains ( which include loops and random chains ) . a comparison between the secondary structure content obtained from the protein data bank and deconvolution demonstrated that the percentage of -helices decreased from 34%42% for experimentally determined secondary structures to about 31% for secondary structures determined by deconvolution ( figure 6 ) .
conversely , the -sheet content increased from 7%12% for experimentally determined secondary structures to approximately 20% for secondary structures determined by deconvolution ( figure 6 ) . a probable explanation for the observed differences may be the usage of lyophilized lysozyme powder for deconvolution .
it has previously been reported that the lyophilization procedure can cause reversible changes in protein conformation and is associated with reduction in the -helical content and increase in the -sheet / random chain content.46 therefore , in the current study , reduction in -helical content and increase in -sheet content was speculated to be due to lyophilization of lysozyme powder . since the secondary structure predictions made using the deconvolution procedure were found to be approximately accurate , use of the deconvolution technique for secondary structure determination was considered to be validated .
conformation of protein structure can be of biological significance both in the adsorbed state and when released from a biomaterial surface .
in the adsorbed state , proper orientation of proteins influences cell interactions ( especially scaffolds in tissue engineering ) , whereas in the free / released state , proper conformation would enable the bioactive form of proteins .
therefore , in this study , bsa and lysozyme were characterized for their secondary structure in both the adsorbed and released states . because both the proteins were -helical proteins , a change in -helical content would be a strong indicator of change in structural conformation , and protein function as a consequence .
the estimated values for -helical content for bsa and lysozyme both in adsorbed and released states are shown in table 2 .
the secondary structure information of powdered ( free state ) bsa and lysozyme was used as a control .
as is evident from table 2 , adsorbed bsa ( on blended and unblended plga samples ) showed an increase ( 2%10% ) in -helical content when compared with powdered bsa .
this indicated that the adsorbed state of bsa had a slightly higher -helical content as compared with the free protein , irrespective of the material surface .
since the native structure of bsa has an -helical content of 52%68% , the observed -helical content in adsorbed bsa has a relatively lesser deviation from the native structure as compared with the free ( powder ) protein .
this improvement in -helical content as compared with free protein was speculated to be due to surface - mediated structural stability .
however , marginal differences in the -helical content of adsorbed bsa were observed between the pf-108 blended and unblended surfaces , except for the pf-1.5 blended sample .
this indicated , that irrespective of the material surface , the change in secondary structure of adsorbed bsa was not significantly different .
similar to the adsorbed state , the bsa released also showed an increase ( 3%7% ) in -helical content as compared with free bsa .
however , there was a small drop in the -helical content for most of the samples from the adsorbed state to the released state .
it is speculated that this reduction in -helical content was probably due to the absence of the polymeric surface .
although there was a small reduction in -helical content from the adsorbed state to the released state , the -helical content in the released state remained higher than that of nonadsorbed ( powder ) bsa .
this indicated that the released state had a relatively smaller deviation from the native state as compared with free bsa .
overall , a decreasing trend of -helical content was observed for bsa from the native state ( 52%68%)>adsorbed state ( 34%42%)>released state ( 35%39%)>powdered state ( 32% ) .
it was also observed that there was a difference in -helical content for the powdered state and the released state that in principle should have a similar -helical content .
this probably indicated that the changes in conformation that occurred during the process of adsorption were not fully reversed upon release ( ie , some changes at the secondary structure were probably maintained ) .
similar to bsa , the -helical content of lysozyme was also estimated in the adsorbed and released state .
there were no significant differences observed in the -helical content of adsorbed lysozyme for pf-108 blended and nonblended meshes .
similarly , in comparison with free lysozyme , lysozyme adsorbed on pf-108 blended and unblended plga microfibrous meshes showed marginal differences in -helical content .
the results for the released lysozyme were similar to those observed for the adsorbed lysozyme .
however , in both situations ( adsorbed and released ) the deviation in -helical content as compared with the native structure obtained from the protein data bank ( 34%42% -helix ) was very small .
the possible reason for the relatively better structural stability of lysozyme could be its smaller size .
it has been reported that an increase in protein concentration leads to a decrease in protein spreading and promoted reorganization of previously adsorbed protein molecules.47 similarly , in this study , it was observed that a higher concentration of lysozyme enabled higher densities of adsorbed lysozyme ( figure 3 ) , that probably leads to a smaller contact area per protein molecule and hence discourages spreading on the microfiber surface , whereas for bsa the large size of the protein probably enabled a higher contact area with the microfiber surface and as a consequence encouraged spreading .
it has been reported previously that spreading of bsa on biomaterial surfaces discourages further adsorption of bsa molecules , limiting the possibility of reorganization / compaction of adsorbed bsa molecules in a time - dependent manner.47 these previously reported studies support our observations of a marginal change in -helical content of adsorbed bsa ( table 2 ) , which was probably due to spreading of bsa and a relatively lesser amount of adsorbed bsa ( figure 3 ) , which was probably due to the spreading that discouraged further adsorption of bsa .
overall , the previous two studies ( figures 2 and 3 , table 2 ) demonstrated that although there was no significant change in the secondary structure of proteins when adsorbed on the blended and unblended plga microfibrous surfaces , the amount of adsorbed protein on the blended surfaces was approximately twice that of the unblended surfaces .
this indicates that surface hydrophilization of plga microfibers via blending with pf-108 enhanced protein adsorption while maintaining the secondary structure of the adsorbed protein .
after confirming the ability of pf-108-modified plga microfiber surfaces to adsorb higher amounts of protein with minimal change in their secondary structure after adsorption , a bioactivity assay was performed in order to determine if the protein adsorbed on the modified surfaces was biologically active . for these studies , lysozyme adsorbed on pf-108-blended and unblended
the lysozyme released at variable time points ( 2 , 8 , and 24 hours ) was used for a bacterial cell lysis - based bioactivity assay .
lysozyme released from unblended plga microfiber meshes was used as a control ( to understand the effect of pure plga surface alone and for comparison with the pf-108 blended surface ) in these experiments .
figure 7 is a plot of the bioactivity of lysozyme ( units / ml ) released from 0.5%2.0% pf-108-blended and unblended plga microfiber meshes as a function of time .
after the first two hours of release , the blended samples released 226286 units of lysozyme , whereas the unblended plga samples released 183 units of lysozyme .
this observation corroborates the results of the lysozyme release study ( figure 3 ) wherein a similar trend was observed .
however , the extent of the differences observed between blended and unblended samples was greater for the release study than for the bioactivity study .
however , the extent of the differences observed between blended and unblended samples decreased at subsequent time points , with the 2-hour time point showing the most prominent difference and the 24-hour time point showing a marginal difference .
further , when the units of lysozyme released at the 2-hour time point were converted to percentage bioactivity , it was observed that all samples ( blended and unblended ) showed more than 80%85% bioactivity . it is speculated that the minimal changes in secondary structure ( table 2 ) did not cause a significant change in percentage bioactivity of both adsorbed and released lysozyme .
therefore , this study demonstrates that the process of adsorption and release of lysozyme on pf-108 blended and unblended plga microfiber samples does not significantly compromise bioactivity .
in our previous studies , we demonstrated that fabrication of electrospun plga microfibrous meshes by blending with small quantities of pf-108 ( 0.5%2.0% ) enabled a significant change in surface hydrophilicity while maintaining or improving the physical properties of native plga .
further , it was demonstrated that these hydrophilized plga microfibers preferentially interacted with water , leading to increased water absorption .
based on these findings , it was hypothesized that increased wettability should result in increased adsorption of protein from aqueous solution .
the current study focused on trying to understand the influence of the presence / absence as well as the extent of surface hydrophilization ( via blending with pf-108 ) of electrospun plga microfibrous meshes on protein ( bsa and lysozyme ) adsorption / release , secondary structure , and function .
the bsa and lysozyme adsorption study demonstrated that , irrespective of type of protein , the pf-108 blended microfiber samples showed a significantly higher protein release as compared with the unblended plga microfiber samples .
however , in comparison with bsa , lysozyme showed a 79-fold increase in release that was speculated to be due to its smaller size and hence greater adsorption . in order to understand the influence of change in surface properties of plga microfibers on secondary structure ( conformation ) of adsorbed protein , ftir spectroscopy was used .
deconvolution analysis of amid i spectra demonstrated that irrespective of surface , fibrous meshes showed a small improvement in secondary structure ( -helical content ) of adsorbed bsa as compared with bsa in the free powder state , whereas lysozyme did not show any significant changes in its secondary structure in the adsorbed or powder state .
further , the bioactivity assay of lysozyme released from adsorbed microfiber surfaces showed a bioactivity of 80%85% .
this demonstrated that the process of adsorption and release of lysozyme from blended plga microfiber meshes did not significantly affect the bioactivity of lysozyme .
overall , these studies demonstrated that pf-108 blended plga microfibrous meshes not only increased the amount of adsorbed protein but also maintained the structural and functional integrity of the adsorbed protein .
hence , the strategy of blending triblock copolymers such as pf-108 with plga for surface modification of electrospun plga microfiber meshes could be a viable strategy for improving protein interaction , adsorption , and downstream cell interaction in tissue engineering applications . | ### Summary:
: background : hydrophobic biopolymers such as polylactide - co - glycolide ( plga , 85:15 ) have been extensively explored as scaffolding materials for tissue engineering applications . more recently ,
electrospun microfiber - based and nanofiber - based scaffolds of plga have received increased attention because they act as physical mimics of the fibrillar extracellular matrix . however , the hydrophobicity of the plga microfiber surface can limit its use in biomedical applications .
therefore , in a previous study , we fabricated pluronic f-108 ( pf-108)-blended plga microfibrous scaffolds that alleviated the hydrophobicity associated with plga by enriching the surface of microfibers with the ethylene oxide units present in pf-108.methods:in this study , we report the influence of the extent of surface enrichment of plga microfibers on their interaction with two model proteins , ie , bovine serum albumin ( bsa ) and lysozyme .
bsa and lysozyme were adsorbed onto plga microfiber meshes ( unmodified and modified ) and studied for the amount , secondary structure conformation , and bioactivity of released protein.results:irrespective of the type of protein , pf-108-blended plga microfibers showed significantly greater protein adsorption and release than the unblended plga samples .
however , in comparison with bsa , lysozyme showed a 79-fold increase in release .
the fourier transform infrared spectroscopy studies for secondary structure determination demonstrated that irrespective of type of microfiber surface ( unblended or blended ) , adsorbed bsa and lysozyme did not show any significant change in secondary structure ( -helical content ) as compared with bsa and/or lysozyme in the free powder state .
further , the bioactivity assay of lysozyme released from blended plga microfiber meshes demonstrated 80%85% bioactivity , indicating that the process of adsorption did not significantly affect biological activity .
therefore , this study demonstrated that the decreased hydrophobicity of blended plga microfibrous meshes not only improved the amount of protein adsorbed ( lysozyme and bsa ) but also maintained the secondary structure and bioactivity of the adsorbed proteins.conclusion:modulating the hydrophobicity of plga via blending with pf-108 could be a viable strategy to improve its interaction with proteins and subsequent cell interaction in tissue engineering applications . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: it is defined as a headache not originated from the head and neck disorders ; rather the pain in the head is caused by gastric dysfunction and its disorders .
treatment of this type of headache is completely reliant on the treatment of the gastric complaint .
reviewing iranian traditional medicine ( itm ) literature , a broad spectrum of herbal medicines that could be useful in the treatment of this type of headache is described .
accordingly , this review was performed to gather and discuss the therapeutic management of this disorder in itm and evaluating related characteristics of each medicinal herb .
in this study , medicinal plants prescribed for gastric headache from different ancient iranian literature is documented . the botanical name , family name , part used ,
about 40 plants , mainly used orally , were prescribed for the treatment of participatory gastric headache .
most of them have the astringent effect , which is related to their dryness temperament .
therefore , they could strengthen the stomach and prevent ascending vapors into the brain that in turn helps to get relief from headache .
in general , herbal medicines with tonic characteristics could be effective in participatory gastric headache . | ### Summary:
: background : participatory gastric headache is a type of headache described in iranian traditional medicine . it is defined as a headache not originated from the head and neck disorders ; rather the pain in the head is caused by gastric dysfunction and its disorders .
treatment of this type of headache is completely reliant on the treatment of the gastric complaint .
reviewing iranian traditional medicine ( itm ) literature , a broad spectrum of herbal medicines that could be useful in the treatment of this type of headache is described .
accordingly , this review was performed to gather and discuss the therapeutic management of this disorder in itm and evaluating related characteristics of each medicinal herb.methods:in this study , medicinal plants prescribed for gastric headache from different ancient iranian literature is documented .
the botanical name , family name , part used , temperaments , rout of administration and dosage forms are provided in this article.results:about 40 plants , mainly used orally , were prescribed for the treatment of participatory gastric headache .
most of them have the astringent effect , which is related to their dryness temperament .
therefore , they could strengthen the stomach and prevent ascending vapors into the brain that in turn helps to get relief from headache .
in addition , they possess reinforcement effect on the brain.conclusion:in general , herbal medicines with tonic characteristics could be effective in participatory gastric headache . |
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: sleep - disordered breathing ( sdb ) is a spectrum of disruptive breathing patterns in sleep in which the upper airway is partially or completely obstructed resulting in airflow symptoms which may vary from mild to severe airflow changes , oxygen desaturation , and arousals [ 1 , 2 ] , or there may be central involvement ( central sleep apnea ) in which there is a lack or loss of the drive to breathe during sleep .
central sleep apnea occurs as a result of high altitude - induced periodic breathing , idiopathic csa , narcotic - induced central apnea , obesity hypoventilation syndrome , and cheyne - stokes breathing .
sdb has been associated with hypertension , cardiovascular disease , and increased risk of fatal and nonfatal cardiovascular events [ 47 ] .
higher levels of serum uric acid have been shown to be associated with increased risk of hypertension , [ 814 ] prehypertension , peripheral arterial disease , diabetes mellitus , and cardiovascular disease through inflammatory pathways [ 47 ] .
animal studies have suggested that sdb is related to elevations in uric acid levels [ 1 , 18 ] .
the hypothesized mechanism is that during hypoxia , there is increased adenosine triphosphate degradation and the release of purine intermediates ( adenosine , inosine , hypoxanthine , and xanthine ) as well as the purine catabolic end product , and uric acid .
however , the association between sdb and high uric acid levels in humans is not clear .
while some studies [ 1821 ] have reported an association between sdb markers and high serum uric acid levels , others have not [ 22 , 23 ] . also , most of the previous studies had small sample sizes and did not examine the association by gender and race / ethnicity . in this context
, we examined the association between sleep duration , snoring , snorting , and daytime sleepiness and high serum uric acid in a large , nationally representative sample of us adults , examining the confounding by age , gender , race / ethnicity , education , smoking status , alcohol intake , physical activity , body mass index , depression , diabetes , and total cholesterol . in this hypothesis generating study , our research hypothesis was that high levels of serum uric acid would be associated with the sleep variables of sleep duration , snoring , snorting , daytime sleepiness , and an additive summary score of the variables .
data from the national health and nutrition examination survey ( nhanes ) 2005 - 2006 and 2007 - 08 were used in this study . the study design and study methodology of the nhanes are available in details elsewhere [ 24 , 25 ] . in brief , the national survey is charged to monitor the health and dietary status of children and adults in the united states .
the survey design utilizes stratified probability samples in multiple stages to develop an accurate representation of the noninstitutionalized civilian population .
nhanes oversamples non - hispanic blacks and mexican americans to provide an adequate sample size to analyze the data based upon race / ethnicity .
the methods employed in the survey included clinical , physical , and laboratory examinations as well as interviews .
a sampling algorithm was used , taking into account counties , blocks , households , and individuals within a household . of the 20497 participants in nhanes 2005 - 2006 and 2007 - 2008
we excluded participants who were pregnant ( n = 393 ) , had prevalent cardiovascular disease ( n = 1275 ) , had missing sleep variables ( n = 1375 ) , or had missing uric acid variables or other missing variables for our multivariable logistic regression models ( n = 1380 ) .
uric acid data in the laboratory portion of the nhanes survey was provided by individuals aged 12 years or older .
high serum uric acid was defined as serum levels of uric acid > 6.8 mg / dl in males based upon clinical usefulness , and previous research [ 2628 ] , as defining hyperuricemia is based on the concentration equal or are above the limit of urate solubility .
likewise , high uric acid was defined as > 6.0 mg / dl for females based upon previous research and clinical usefulness .
the laboratory collection procedure is available in the nhanes laboratory procedures manual [ 24 , 25 ] .
the nhanes interview questions which regarded sleep behavior were how much sleep do you usually get at night and on weekdays or workdays ? ; in the past 12 months , how often did you snore while you were sleeping ? ; in the past 12 months , how often did you snort , gasp , or stop breathing while you were asleep ? ; in the past month , how often did you feel excessively or overly sleepy during the day ? from the four sleep questions , we derived four sleep variables identified as sleep duration ; snoring ; snorting ; daytime sleepiness .
the 5 categories for sleep duration consisted of less than or equal to 5 hours of sleep , 6 hours of sleep , 7 hours of sleep , 8 hours of sleep , and greater than or equal to 9 hours of sleep .
our snorting , and snoring variables were categorized from the participants ' responses of never or rare to the corresponding 02 times / week descriptor ,
our daytime sleepiness variable combined participants ' responses of never or rare , sometimes , and often into the 015 times / month combination of those responses and almost always , using the 16 or more times / month descriptor .
an ad hoc additive composite score of the sleep variables was designed to study the simultaneous additive effect of the multiple sleep variables and was based upon previous research [ 3032 ] . to create the additive composite score , we dichotomized the four sleep variables , based upon clinical significance , and then we combined them .
sleep duration was dichotomized into a category of 5 hours of sleep or less and a category of greater than 5 hours of sleep .
snoring was dichotomized into snoring 3 - 4 nights or more per week and snoring less than 3 - 4 nights per week .
snorting was dichotomized into snorting 3 - 4 nights or more per week and snorting less than 3 - 4 nights per week .
the daytime sleepiness variable was created as a dichotomized variable with 16 times or more per month as the cut - point .
the individual scores were accumulated into the additive composite score of sleep variables , which therefore had a range of values from 0 to 4 .
the additive composite score 0 , represented that no sleep variables were present ; whereas a score of 4 indicated the presence of all 4 variables .
the covariates used from the nhanes survey were age , sex , race / ethnicity , education , smoking , alcohol intake , physical activity , body mass index , hypertension , depression , diabetes , and cholesterol .
self - report was the basis for age , sex , race / ethnicity , education , smoking , alcohol intake , depression , and diabetes .
the questions posed for alcohol use asked the amount of alcohol intake in grams / day .
current alcohol use was defined as 1 or more alcoholic drinks in the previous year .
the educational level was categorized as less than high school graduation , high school graduation , and more than high school graduation .
smoking status was defined as never use ( less than 100/lifetime ) , current use ( a history of 100 or more cigarettes and continued use ) , and former use ( a history of 100 or more cigarettes and no longer smoking ) .
moderate physical activity was defined as activities which increased the heart and breathing rate such as walking briskly , cycling , swimming , or playing golf for at least 10 minutes per week .
depression was self - identified as feeling down , depressed , or hopeless more than half of the days or nearly every day within the previous two weeks .
body mass index ( bmi ) was derived as weight in kilograms divided by height in meters - squared .
a mercury sphygmomanometer was used to take 3 blood pressure measurements and the mean systolic and diastolic were recorded .
high blood pressure was defined as a blood pressure with a mean systolic of 140 mm hg or above , or a mean diastolic blood pressure of 9 mm hg or above , or a positive response to the use of blood pressure reducing medications .
total serum cholesterol levels were determined enzymatically using the roche hitachi 717 in 2005 , roche hitachi 717 and 912 in 2006 , and the roche modular p chemistry analyzer in 2007 - 2008 .
the details of blood collection , processing , and analysis are available in the laboratory procedures manuals [ 24 , 25 ] .
descriptive characteristics of the study participants by high serum uric acid ( serum levels of uric acid > 6.8 mg / dl in males and > 6.0 mg / dl in females ) were determined utilizing the chi - square test or analysis of variance , as needed .
the association of the sleep variables ( sleep duration , snoring , snorting , daytime sleepiness , and the adhoc additive composite score of sleep variables and serum uric acid were evaluated with three logistic regression models .
we completed ( 1 ) an age-(years ) , gender-(male , female ) adjusted logistic regression model ; ( 2 ) a multivariable model 1 in which we adjusted for age ( years ) , gender ( male , female ) , race / ethnicity ( non - hispanic whites , non - hispanic blacks , mexican americans , and others ) , education ( below high school , high school , and above high school ) , smoking ( never smoker , former smoker , and current smoker ) , alcohol intake ( absent , present ) , moderate physical activity ( absent , present ) and body mass index ( obese , nonobese ) and ( 3 ) a multivariable model 2 in which we also included hypertension ( absent , present ) , depression ( absent , present ) , diabetes ( absent , present ) , and total cholesterol ( mg / dl ) . in these analyses , we used logistic regression models with the categorical high serum uric acid ( level > 6.8 mg / dl in males , and > 6.0 mg / dl in females ) as the outcome variable .
trend tests were performed with the sleep variables and the summary score as an ordinal variable in the corresponding multivariable models .
subgroup analysis by gender , and race / ethnicity were also conducted . to examine potential collinearity , regression diagnostics for collinearity
were performed ; there were no significant collinearity of variables included in the multivariable model .
the analyses were weighted to adjust for unequal probabilities of selection , oversampling , and nonresponse by using sudaan ( version 8.0 ; research triangle institute , research triangle park , nc ) and sas ( version 9.1 . ; sas institute , cary , nc ) software .
a tabular description of the study population based upon the additive composite score of sleep variables is presented in table 1 .
there were more participants who had a composite score of sleep variables of zero who were educated above high school , who exercised moderately , who had lower cholesterol , who were normal weight , not depressed , and who did not have diabetes .
overall , the study sample population was a middle - aged ( mean age 44.8 years ) multiethnic sample consisting of non - hispanic whites ( 72.6% ) , non - hispanic blacks ( 10.0% ) , and mexican americans and other race / ethnicities ( 17.4% ) . the majority ( 58.4% ) of this sample was educated above the high school level , and consisted of current drinkers ( 74.3% ) .
there was an equal distribution of normal weight , overweight , and obese bmi groups .
never smokers and former smokers comprised 76.4% of the sample , ( 52.8% and 23.6% , resp . ) , and current smokers comprised 23.6% .
also , depression was reported by 5.1% and diabetes mellitus was present in 8.9% of the subjects .
table 2 presents the associations between various sleep variables , including sleep duration , snoring , snorting , daytime sleepiness , and the additive composite score of sleep variables and their association with high serum uric acid , defined as serum levels > 6.8 mg / dl in males and 6.0 mg / dl in females .
we found that sleep duration was significantly associated with high serum uric acid for the sleep duration of 8 hours , which was protective in each of the models .
the adjusted odds ratios for daytime sleepiness , and the additive composite score were associated with high serum uric acid in the age- , gender - adjusted model .
the adjusted odds ratios ' confidence intervals for multivariable model 2 included the value of 1 , indicating that the associations for multivariable model 2 may be due to chance .
similarly , the adjusted odds ratios for snorting had confidence intervals which included the value of 1 , indicating that the associations of uric acid and snorting may be due to chance . the adjusted odds ratios for snoring 5 hours or more were significant across all models . in terms of trend
, there was a significant p - trend for sleep duration , snoring , daytime sleepiness , and with the additive composite score of sleep variables across the age- , sex - adjusted and multivariable 1 logistic regression models .
table 3 presents the association between the additive composite score and high serum uric acid by gender .
consistent with findings in the whole sample , we found that a higher additive composite score was associated with high serum uric acid in the age - adjusted logistic regression model and the multivariable model 1 in both men as well as women ( although the confidence interval for an additive composite score of 1 for men could be due to chance due to the 95% confidence interval including the value of 1 ) . with additional adjustment for clinical variables ,
a significant p - trend existed in the age and multivariable model 1 for both genders .
similarly , table 4 presents the association between the additive composite score of sleep variables and high serum uric acid by race / ethnicity . here
also , we found that higher additive composite score of sleep variables as well as the p - trend were associated with high serum uric acid in the age- , sex - adjusted and the multivariable model 1 in all major racial / ethnic groups studied , but was no longer associated with additional adjustments in the multivariable model 2 .
the confidence intervals included the value of 1 , indicating the results may be due to chance for non - hispanic whites , and mexican americans with additive composite scores of 1 in the age- , sex - adjusted model .
also , for mexican americans , the confidence interval included the value of 1 in the additive composite score of 1 category in multivariable model 1 .
figure 1 displays the mean uric acid levels in relation to the additive composite scores of the sleep variables with the 95% confidence levels in age- , sex - adjusted model .
the uric acid levels increased from a mean of 5.33 mg / dl with no sleep variables to 5.87 mg / dl with 3 or more sleep variables ( p < 0.0001 ) .
in a large , national , multiethnic , cross - sectional sample of us adults , we found a significant initial association between symptoms of daytime sleepiness , snoring more than 5 nights per week and the additive composite score with high serum uric acid in an age- , gender - adjusted model , and a multivariable model adjusting for age , gender , race / ethnicity , education , smoking , alcohol intake , physical activity , and body mass index .
however , the association was attenuated and not significant with the addition of clinical factors such as hypertension , depression , diabetes , and total cholesterol .
our initial finding of an association is significant because it has been shown that even mild hyperuricemia is associated with hypertension , diabetes , peripheral artery disease , and cardiovascular disease [ 817 ] .
it is possible that hyperuricemia associated with the sleep variables may therefore explain part of the increased - cardiovascular disease risk seen in sdb .
the exact biological mechanism underlying an association between the sleep variables and high serum uric acid is not clear .
however , previous animal studies have shown that intermittent hypoxia and resultant oxygen desaturation in sdb may be associated with subsequent activation of inflammatory pathways and that serum uric acid levels are also elevated in the process . in a cross - over study of 10 men exposed to 6 hours of intermittent hypoxia for 4 days , the researchers showed an increase in uric acid production during the 4 days of intermittent hypoxia and suggested that this elevation in uric acid reflects the production of reactive oxygen species through the xanthine oxidase pathway . in the current study ,
positive associations between daytime sleepiness , snoring more than 5 nights per week , and the additive composite score with high serum uric acid were found to be initially present in the multivariable model 1 , where we adjusted for lifestyle risk factors , but were found to be attenuated and no longer present in the multivariable model 2 , where we additionally controlled for clinical factors such as hypertension , depression , diabetes , and total cholesterol .
this indicates that part of the initially observed association of the sleep variables and high serum uric acid may be mediated by the clinical factors such as hypertension , depression , diabetes , and total cholesterol .
as noted earlier , there is correlation with hypertension , diabetes , bmi , and total cholesterol and these factors could be acting as effect modifiers in the association .
a prospective longitudinal study is needed to explore this possibility . in the race / ethnicity subgroup analysis
, the association persisted in the age - sex model and multivariable model 1 . for non - hispanic blacks with an additive composite score of 1 , the association persisted in multivariable model 2 .
non - hispanic blacks have been reported to have higher serum uric acid levels than other racial / ethnic groups .
similarly , non - hispanic blacks have also been reported to have a higher prevalence of sdb than other racial / ethnic groups [ 35 , 36 ] .
since sdb is known to be associated with increased risk of cardiovascular disease , our results indirectly suggest that hyperuricemia associated with sleep variables may be a key player in the higher cvd risk in blacks .
additional general population studies are needed to examine racial / ethnic differences in the association between sleep variables and high serum uric acid and confirm or refute our initial findings .
this study has several strengths , including the large , national sample size , high quality , standardized data collection , and the availability of information of several confounding and mediating factors .
the study design , being cross - sectional due to the nature of the nhanes sleep variables , prohibits the generation of inferential or temporal evaluations of the sleep variables and uric acid .
this study used self - reported sleep variables , and there is the potential of nondifferential misclassification bias .
there were 1375 participants in nhanes with missing data on sleep variables , who were excluded from the current analysis .
those who were excluded due to missing data were more significantly likely to be older , not current drinkers , and they do not exercise regularly .
the exclusion of these subjects may have introduced selection bias to our results and our estimates of association may be an under- or an overestimate of the true association between sleep variables and uric acid . in summary , this study shows that there is an initial positive association between the sleep variables , including daytime sleepiness , snoring more than 5 nights per week , and an additive composite score of sleep variables with high serum uric acid in a national study of us adults that attenuated with adjustment for clinical factors such as diabetes mellitus , depression , total cholesterol , and hypertension .
our hypothesis - forming study suggests the need to examine the pathophysiological role of sleep risk factors with high serum uric acid levels employing polysomnography or other objective measures of sleep , and a longitudinal study design to clarify the temporal nature of this relationship . | ### Summary:
: sleep disordered breathing as well as high serum uric acid levels are independent risk factors for cardiovascular disease .
however , studies evaluating the relationship between sleep - disordered breathing and hyperuricemia are limited .
we examined the 20052008 national health and nutrition examination survey 's sleep variables and high serum uric acid among 6491 participants aged 20 years .
the sleep variables included sleep duration , snoring , snorting , and daytime sleepiness .
the main outcome was high serum uric acid level , defined as levels of serum uric acid > 6.8 mg / dl in males and > 6.0 mg / dl in females .
we found that snoring more than 5 nights per week , daytime sleepiness , and an additive composite score of sleep variables were associated with high serum uric acid in the age- , sex - adjusted model and in a multivariable model adjusting for demographic and lifestyle / behavioral risk factors .
the association was attenuated with the addition of variables related to clinical outcomes such as depression , diabetes , hypertension , and high - cholesterol levels .
our results indicate a positive relationship between sleep variables , including the presence of snoring , snorting , and daytime sleepiness , and high serum uric acid levels . |
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: a 24yearold in her third pregnancy , 11 weeks and 3 days gestation , turned for evaluation , following an episode of mild vaginal bleeding , diarrhea , palpitations , and dyspnoea .
her obstetric history includes two previous successful pregnancies stimulated by pergonal ( serono ) injections .
she started using ovarian stimulatory agents after one and a half year of idiopathic infertility and 2 years after her last delivery .
she successfully conceived using a 5day pretreatment of 50 mg clomiphene citrate ( teva ) and timed intercourse . upon arrival
, her pulse was noted to be 160 beats per minute and blood pressure 117\58 .
hemoglobin was 9.8 g\dl , fibrinogen 307 mg\dl , ptinr 1.22 , tsh 0.09 uiu\ml , fft3 4.3 ng\ml , ft4 3.77 ng\dl , and hcg 1002010 international units ( iu ) .
trichorionic triamniotic triplets and an additional dense hyperechoic tissue measuring 9.5 * 6 cm ( fig .
1a ) separated from the three sacks which fitted the sonographic description of a complete molar pregnancy was visible on er ultrasound .
in addition , nuchal translucency of all three fetuses was within normal limits and three different pulses were observed . the additional tissue measured 9.5 * 8.2 cm ( fig .
1b ) , was separate from all three sacks and sonographically appeared as a complete molar pregnancy , which further strengthened the suspected diagnosis of a normal triplet pregnancy along with a complete molar pregnancy .
the explanation was the increased risk for persistent trophoblastic disease , early onset preeclampsia , fetal death , and premature labor .
after patient consent , she was sent to a tertiary facility for evacuation and hcg followup .
the procedure was performed without any complications and the material obtained was sent for a pathological evaluation .
the pathological report indicated a healthy placental material correlating with the live fetuses alongside a molar diseased tissue correlating with a complete mole ( fig .
due to lack of compliance of the patient , two hcg tests were done for 2 months .
after 1 month , her hcg level was 10,000 iu and after 2 months , it was 150 iu .
( c ) histology of the intrauterine evacuated material showing cisterns and focal trophoblastic proliferation .
a complete hydatiform mole with a coexisting fetus is a rare entity seldom described in english literature .
the incidence of a complete hydatiform mole with two coexisting fetuses is unknown due to the rarity of case reports .
a complete hydatiform mole along with three coexisting fetuses was never described before in english literature .
it might be misdiagnosed as a growing subchorionic hematoma or a twin gestation along with a partial molar pregnancy .
ovarian medical stimulation due to infertility is one of the major risk factors , which need to be considered when diagnosing an inconclusive case 2 .
the infertility factor and the importance of pregnancy make treatment decision difficult for the family and medical staff .
gtd is divided into several groups including : ( 1 ) complete\partial hydatiform mole ; ( 2 ) persistent\invasive gestational trophoblastic neoplasia ; ( 3 ) choriocarcinoma ; ( 4 ) placental site trophoblastic tumor 3 , 4 .
the incidence of ptd after a singleton complete molar pregnancy is between 1525% and 35% after a singleton partial molar pregnancy .
it is known that the risk of ptd , distant metastasis , and chemotherapeutic treatment increase in a complete molar pregnancy with a coexisting live fetus .
ptd incidence was shown to be as high as 55% , if pregnancy was chosen to be continued in one study 6 .
considering the increased linear risk curve described in literature , the risk in our case is even higher 7 .
the exact incidence of a quadruplet pregnancy with three coexisting fetuses is n't known due to rarity of described cases .
in contrast , according to wee et al . , gestational age at diagnosis does not change postevacuation outcomes or ptd prognosis . adding this to our management consideration
severe clinical symptoms such as : vaginal bleeding , pelvic pain and pressure , hyperthyroidism , hyperemesis gravidarum , anemia , and a rapidly growing uterus are what make the patient turn up for a medical evaluation .
fullblown hyperthyroidism almost never occurs in a singleton molar pregnancy even though the subclinical form occurs in 5% of cases . in a molar pregnancy with a single coexisting fetus , fullblown
fullblown disease should be addressed immediately in order to prevent thyroid storm with its complications .
the best treatment is termination of pregnancy ( top ) , which will treat the source and eliminate the disease .
our patient exhibited hyperthyroid conditions in the form of severe diarrhea and tachycardia of 160 beats per minute .
severe pregnancy complications should also be thoroughly considered and explained to the patient before making the decision to continue or terminate the pregnancy 8 .
pregnancy complications include early onset preeclampsia , which is estimated to occur in 27% of complete molar pregnancies with a coexisting fetus .
no data exists about more than one coexisting fetus , but the incidence is estimated to be higher .
preterm birth before 28 weeks gestation is estimated to occur in 62% of cases . as previously emphasized , the rate in more than one coexisting fetus is not known , but estimated to be higher .
the incidence seems to be higher in cases with more than one coexisting fetus 9 . as a result of these pregnancy complications along with the estimated high risk for ptd
in contrast to our professional opinion , there is an opposite opinion in the literature advising conservative treatment .
this advice is built on the hypothesis that after considering all pregnancy complications , 40% of patients give birth to a live fetus .
in addition , the reported incidence of ptd and chemotherapy treatment was not significantly higher than in a singleton complete molar pregnancy according to some reports . added to these factors , gestational age at diagnosis was not different in ptd incidence or disease prognosis 10 .
all these risk calculations were considered when the discussion was of a complete molar pregnancy with one or two coexisting fetuses , but in our case , there were three coexisting fetuses .
pregnancy complications , ptd , fetal and maternal morbidity , and mortality , which were never explored because of the case rarity considered in this case .
the subject of complete molar pregnancy coexisting with more than one live fetus should be further investigated and shed some light on the best way of management .
| ### Summary:
: key clinical messagethis case is extraordinary because it was never before described in english literature .
the case describes a longstanding debate about the safety of carrying this pregnancy to term .
some authors are for and some are against . the risks and benefits should be thoroughly reviewed before a decision is made . |
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: ( nematoda : trichostrongyloidea ) , commonly known as the wire worm or barber pole worm causes cosmopolitan helminthiasis and shows wide distribution among ruminants .
this abomasa nematode is responsible for the economic losses due to anemia , weight loss and reduced milk production .
the prevalence rate of haemonchosis in iran has highly declined in the past two decades ( 1 ) .
considering the rise in temperature and light rain during the past decades along with mass treatment and control strategies are responsible for this event . as the result of the drug resistance , epidemiological parameters , control strategies and pathological future ,
it is important to differentiation between haemonchus species . despite the importance of morpho - molecular structures in haemonchus spp .
the genetic status of marshallgia marshalli and m. occidentalis based on the its2 sequencing was studied and both species are conspecific ( 4 ) . moreover , in a similar study a complete its2 and part of 28s - rdna were used to distinguish m. marshalli from ostertagia gruehneri ( 5 ) .
sequence data of the its is extensively used and it s a high - resolution marker for several parasitic nematodes ( 36 ) .
for example , cuticular ridge patterns ( 7 ) , length of the spicules ( 8) and novel morphometric parameters for identifying individual speciments of haemonchus spp . in adult male and female in ruminants of north america ( 9 ) . considering the specimens in mixed infections , hybrids of different species , morphological similarity of the species , and the absence of morphomolecular data on this abomasal nematodes in iran ,
more studies are required to confirm the identity of some haemonchus species . according to the above information
, this study aimed to distinguish h. contortus from h. longistipes based on its2-ribosomal dna in sheep , goat and camel isolates as well as to identify the morphometrics of spicules in the prevalent species of haemonchus in the different ruminants in iran .
two hundred seventy adult male haemonchus were collected from the abomasa of naturally infected animals which included sheep ( hst , hsg and hsk , n=90 ) , goat ( hgt and hgk , n=90 ) and camel ( hct and hci , n=90 ) . the sampling was performed at local abattoirs from four different provinces in iran ; tehran , isfahan , khuzestan and gilan ( table 1 ) .
haemonchus isolates used in the present study the worms repeatedly were washed with a phosphate buffer saline solution and were labeled using the abbreviated names of the haemonchus , host and collection site .
goat and camel isolates were cleared in phenol - alchohol and examined for spicule length and right / left spicule barber length in male worms ( 8 , 9 ) . in order to check for statistic analyse ,
t - student test and spss 18 software were adopted . a p - value of < 0.05 was considered to be significant .
genomic dna was extracted from individual worms using a dna isolation kit ( mbst , iran ) , following the manufacturer s recommendation .
the crushed worms were , then , laysed in 180 l of laysis buffer in a 1.5 ml tube .
protenase k ( 20 l ) was added and the mixture was incubated for 10 min . at 55c .
genomic dna was amplified by pcr using specific primers hci - f : 5ctc - gtc - tgg - ttc - agg - gtt3 ( forward ) and hci - r : 5gta - acc - tcg - ctgagc - tca3 ( reverse ) for its2 region .
the primers were designed according to the available nucleotide sequence data from its2 in genbank ( accession no .
pcr volume was 100 l containing 1pcr buffer , 2 mm mgcl2 , 2 mm dntps , 0.4 mol of each primer , 2.5 unite/l taq dna polymerase ( cinnagen ) and 1 l dna sample in an automated thermocycler ( biorad - italia ) .
the pcr was performed under the following conditions : 5 minutes of denaturation at 94c followed by 35 cycles of 45 s at 94 c , 58c ( annealing ) , 45 s at 72 c ( denaturation ) and final extention of 72c for 5 min .
samples without genomic dna were included in each amplification run as the negative controls . a 1000 bp ladder molecular weight marker ( vivantis - romania )
pcr products were resolved in 1.5% agarose gels , stained for 10 minutes in ethidium bromide , detected on a trans - illuminator and photographed digitally .
according to the instructions provided by the manufacturer , the pcr products were purified from each sample using a dna kit ( mbst , iran ) .
its2 pcr production of both haemonchus species were purified and digested using 1 l of hpa1 ( 10 ui ) restriction enzyme ( fermenras ) at 37 c for overnight .
the restriction fragments were analyzed using electrophoreses on 2% agarose gels , stained and photographed upon trans - illumination .
the purified pcr products were sequenced for all samples ( kawsar biotech co. iran ) .
the obtained sequences were analyzed using the program called chromas software and , subsequently , aligned with the clustal w2 software .
sequences available in the national center for biotechnology information ( www.ncbi.nlm.nih.gov/ ) were included in the final alignment for comparison with the obtained sequences .
pairwise comparisons were conducted of the level of sequence differences ( d ) using the formula
d=1-(m / l ) , where m is the number of alignment positions at which the two sequences have a base in common , and l is the total number of alignment positions over which the two sequences are compared ( 10 ) .
two hundred seventy adult male haemonchus were collected from the abomasa of naturally infected animals which included sheep ( hst , hsg and hsk , n=90 ) , goat ( hgt and hgk , n=90 ) and camel ( hct and hci , n=90 ) . the sampling was performed at local abattoirs from four different provinces in iran ; tehran , isfahan , khuzestan and gilan ( table 1 ) .
haemonchus isolates used in the present study the worms repeatedly were washed with a phosphate buffer saline solution and were labeled using the abbreviated names of the haemonchus , host and collection site .
goat and camel isolates were cleared in phenol - alchohol and examined for spicule length and right / left spicule barber length in male worms ( 8 , 9 ) . in order to check for statistic analyse , t - student test and spss 18 software were adopted . a p - value of < 0.05 was considered to be significant .
genomic dna was extracted from individual worms using a dna isolation kit ( mbst , iran ) , following the manufacturer s recommendation .
the crushed worms were , then , laysed in 180 l of laysis buffer in a 1.5 ml tube .
protenase k ( 20 l ) was added and the mixture was incubated for 10 min . at 55c .
genomic dna was amplified by pcr using specific primers hci - f : 5ctc - gtc - tgg - ttc - agg - gtt3 ( forward ) and hci - r : 5gta - acc - tcg - ctgagc - tca3 ( reverse ) for its2 region .
the primers were designed according to the available nucleotide sequence data from its2 in genbank ( accession no .
pcr volume was 100 l containing 1pcr buffer , 2 mm mgcl2 , 2 mm dntps , 0.4 mol of each primer , 2.5 unite/l taq dna polymerase ( cinnagen ) and 1 l dna sample in an automated thermocycler ( biorad - italia ) .
the pcr was performed under the following conditions : 5 minutes of denaturation at 94c followed by 35 cycles of 45 s at 94 c , 58c ( annealing ) , 45 s at 72 c ( denaturation ) and final extention of 72c for 5 min .
samples without genomic dna were included in each amplification run as the negative controls . a 1000 bp ladder molecular weight marker ( vivantis - romania )
pcr products were resolved in 1.5% agarose gels , stained for 10 minutes in ethidium bromide , detected on a trans - illuminator and photographed digitally .
according to the instructions provided by the manufacturer , the pcr products were purified from each sample using a dna kit ( mbst , iran ) .
its2 pcr production of both haemonchus species were purified and digested using 1 l of hpa1 ( 10 ui ) restriction enzyme ( fermenras ) at 37 c for overnight .
the restriction fragments were analyzed using electrophoreses on 2% agarose gels , stained and photographed upon trans - illumination .
the purified pcr products were sequenced for all samples ( kawsar biotech co. iran ) .
the obtained sequences were analyzed using the program called chromas software and , subsequently , aligned with the clustal w2 software .
sequences available in the national center for biotechnology information ( www.ncbi.nlm.nih.gov/ ) were included in the final alignment for comparison with the obtained sequences .
pairwise comparisons were conducted of the level of sequence differences ( d ) using the formula d=1-(m / l ) , where m is the number of alignment positions at which the two sequences have a base in common , and l is the total number of alignment positions over which the two sequences are compared ( 10 ) .
although the spicules size and the distance of terminal spine are only minor differences between h. contortus from sheep and goat , these parameters were significant ( p<0.05 ) for differentiation of h. contortus from h. longistipes ( table 2 ) .
mean of the morphometric data of haemonchus isolates from three different hosts * mesurements are min - max ranges followed by meansd in parentheses .
copulatory bursa and spicules in h. contortus ( right ) and h. longistipes ( left ) dna amplification of the its2-rdna produced a single fragment of 295 bp for all the h. contortus from sheep and goat ( fig 2 , left ) , while a 314 bp in length were obtained for the h. longistipes samples ( fig .
agar gel electrophoresis of its2 pcr product of h. contortus ( left ) of sheep ( lane 1&2 ) and goat ( lane 3 ) and h. longistipes ( right ) of camel ( lane 19 ) from the isolates in iran , c : negative dna control , m : dna marker rflp patterns of h. contortus and h. longistipes were analyzed after digestion of the pcr products by hpa1 restriction enzyme .
restriction enzyme pattern of the its2 region of h. contortus from the sheep isolates ( left , lane 1&2 ) and goat ( left , lane 3&4 ) using hpai represent 1 fragments of 278 bp ( lane 1&3 undigested and lane 2&4 digested ) and of h. longistipes from camel isolates ( right , lane 1&2 ) represent 2 fragment of 113 and 135 bp , m : dna marker in fig .
3 , two different fragments , 17 and 278 bp ( left ) , and three fragments , 66 , 113 and 135 bp ( right ) , were obtained using the restriction enzyme hpa1 in h. contortus and h. longistipes , respectively ( the fragments of 17 and 66 in both species were not observed ) .
the second internal transcribed spacer of ribosomal dna of all the haemonchus isolates was sequenced .
a comparison of the sequence identified in this study with the previously recorded h. contortus ( of sheep or goat ) and h. longistipes ( of camel ) nucleotide sequences in the genbank showed 100% similarity ( accession no .
hq844231.1 and ab682683 , respectively ) . despite the fact that differences in 16 nucleotides between h. contortus and h. longistipes were observed , all the its2-rdna complete sequence of h. contortus and h. longistipes showed to be 100% identical with the data sequence presented in the genbank database ( fig .
alignment of the its2 nuclear ribosomal dna sequences ( 5 to 3 ) of h. contortus of sheep and h. longistipes of camel , by clustal w2 , conserved nucleotides are indicated with asterisks and gaps are indicated with hyphens . ab682683.1 isolated from camel and hq 844231.1 isolated from sheep mp analysis , based on the complete sequences of its2 gene marker , showed that haemonchus isolates could be classified in two clades of h. contortus and h. longistipes ( fig . 5 ) .
phylogenetic relationships of haemonchus parasite based on its2 sequences , echinococcus granulosus ( ab77790801 ) was used as an out - group .
although the spicules size and the distance of terminal spine are only minor differences between h. contortus from sheep and goat , these parameters were significant ( p<0.05 ) for differentiation of h. contortus from h. longistipes ( table 2 ) .
mean of the morphometric data of haemonchus isolates from three different hosts * mesurements are min - max ranges followed by meansd in parentheses .
copulatory bursa and spicules in h. contortus ( right ) and h. longistipes ( left )
dna amplification of the its2-rdna produced a single fragment of 295 bp for all the h. contortus from sheep and goat ( fig 2 , left ) , while a 314 bp in length were obtained for the h. longistipes samples ( fig .
agar gel electrophoresis of its2 pcr product of h. contortus ( left ) of sheep ( lane 1&2 ) and goat ( lane 3 ) and h. longistipes ( right ) of camel ( lane 19 ) from the isolates in iran , c : negative dna control , m : dna marker rflp patterns of h. contortus and h. longistipes were analyzed after digestion of the pcr products by hpa1 restriction enzyme .
restriction enzyme pattern of the its2 region of h. contortus from the sheep isolates ( left , lane 1&2 ) and goat ( left , lane 3&4 ) using hpai represent 1 fragments of 278 bp ( lane 1&3 undigested and lane 2&4 digested ) and of h. longistipes from camel isolates ( right , lane 1&2 ) represent 2 fragment of 113 and 135 bp , m : dna marker in fig .
3 , two different fragments , 17 and 278 bp ( left ) , and three fragments , 66 , 113 and 135 bp ( right ) , were obtained using the restriction enzyme hpa1 in h. contortus and h. longistipes , respectively ( the fragments of 17 and 66 in both species were not observed ) .
the second internal transcribed spacer of ribosomal dna of all the haemonchus isolates was sequenced . a comparison of the sequence identified in this study with the previously recorded h. contortus ( of sheep or goat ) and h. longistipes ( of camel ) nucleotide sequences in the genbank showed 100% similarity ( accession no .
hq844231.1 and ab682683 , respectively ) . despite the fact that differences in 16 nucleotides between h. contortus and h. longistipes were observed , all the its2-rdna complete sequence of h. contortus and h. longistipes showed to be 100% identical with the data sequence presented in the genbank database ( fig .
alignment of the its2 nuclear ribosomal dna sequences ( 5 to 3 ) of h. contortus of sheep and h. longistipes of camel , by clustal w2 , conserved nucleotides are indicated with asterisks and gaps are indicated with hyphens .
ab682683.1 isolated from camel and hq 844231.1 isolated from sheep mp analysis , based on the complete sequences of its2 gene marker , showed that haemonchus isolates could be classified in two clades of h. contortus and h. longistipes ( fig .
phylogenetic relationships of haemonchus parasite based on its2 sequences , echinococcus granulosus ( ab77790801 ) was used as an out - group .
strongylid nematodes represent the most important parasites of the digestive tract of wild and domestic ruminants in the world .
molecular approaches are needed to study of the phenomena such as host parasite interaction , genetic diversity , drug resistance and molecular polymorphisms .
many studies in the molecular research of trichostrogylid nematodes have been conducted based on the nuclear rdna , particularly from the its gene ( 11 , 12 ) .
studied the prevalence and intensity of abomasal helminths in sheep from three climatic zones ( 1 , 13 ) .
their results revealed that in recent years , significant decrease has occurred in alimentary helminthiasis of the small domestic ruminants in iran .
the prevalence of h. contortus in iran has been reported to be 49% ( 14 ) and 3.62% in sheep ( 1 ) , 6.7% in goat ( 13 ) and 0.8% in wild sheep ( 15 ) . in this study ,
the morpho - molecular characteristics of h. contortus and h. longistipes from three different climatic zones ( four provinces ) and host isolates in iran were determined stevenson et al .
their results showed that three ( 1.3% ) nucleotide differences are present between the its2 sequences of these species .
the comparison of the nucleotide sequences of its-2 of h. contortus and h. placei from uzbekistan revealed differences in six ( 2.6% ) nucleotides ( 6 ) .
findings of this study showed that the spicule lengths and the distance of the terminal barb from the spine of the right and left spicules in h. longistipes are statistically more significant than h. contortus ( p<0.05 ) .
moreover , there is morphologically significant difference in the spicules size between the h. contortus and the h. longistipes .
in addition , it was found that based on the morphometric and molecular findings there is no difference between h. contortus from sheep or goat isolates ; and it seems that h. contortus adapts to different hosts , such as sheep and goat . a nucleotide difference of 5.1% ( 16/314 ) to 5.4% ( 16/295 )
was observed between h. long - istipes and h. contortus from the iranian isolates at 16 variable sequence positions in the its2-rdna .
could be categorized into two groups , h. longistipes from the came lisolate and h. contortus from the sheep or goat isolate from iran . moreover ,
no variation was observed in the composition of the obtained its2-rdna sequences and the sequences deposited in the genbank .
pcr - restriction fragment length polymorphism with endonuclease hpai has different digestion pattern in two haemonchus species .
a band of approximately 278 was revealed ; whereas , two bands of approximately 135 , 113 were produced for the h. longistipes samples .
therefore , digestion of pcr products with hpa1 endonuclease could be used to differentiate between the two haemonchus species .
stevenson et al . detected 2 diagnostic sites for the endonucleases bfai and foki for description of the h. placei and the h. contortus ( 16 ) . in the present study ,
the pcr products from all of the h. contortus samples of sheep and goat were revealed as a single band of 295 bp in size . whereas , the one step assay of the h. longistipes , with a 314 bp band and using hci - f and hci - r primers , could detect a suitable differentiation between the h. contortus and the h. longistipes .
this pair of primers could introduce as a validate and reliable primer with respect to the target gene .
no significant correlation was observed between the spicule characteristics in the h. contortus isolated from sheep and goat .
the results obtained from these morphometric parameters of the spicule were confirmed using sequence analysis .
although , the present research is the first report on molecular study and morphological characteristics of the haemonchus species in iran , it has important implications for the population s biology and genomic patterns as well as control of the haemonchus species . however , further studies are needed using greater samples from various geographical origins . | ### Summary:
: background : haemonchosis has a negative effect on the farming industry throughout the world , especially in the tropic and sub - tropic countries .
the present study was carried out to differentiate haemonchus species from its main hosts in iran , including sheep , goat and camel.methods:the identification took place based on the morphometrics of the spicules and molecular characters .
two hundred seventy adult male nematodes were collected from the abomasums of different ruminants ( 90 samples from each animal ) at the slaughterhouses from different localities in iran .
samples were morphologically identified according to the spicules morphometric measurements . in the section on molecular study ,
10 samples of each haemonchus isolates were genetically examined .
a simple pcr - restriction fragment length polymorphism ( pcr - rflp ) assay of the second internal transcribed spacer of ribosomal dna ( its2-rdna ) were described to confirm the pcr results.results:pcr-rflp profile obtained from the restriction enzyme hpa1 in h. contortus and h. longistipes indicated 1 ( 278 bp ) and 2 ( 113 and 135 bp ) different fragments , respectively .
the morphological parameters clearly distinguish h. contortus from h. longistipes .
moreover , regarding the its2-rdna , sequences of 295 bp and 314 bp were obtained from h. contortus and h. longistipes , respectively.conclusion:the genotypic results are in agreement with the phenotypic findings of both species . |
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: the most common indications for chest wall reconstruction are repair of defects due to tumor resection , infection , radiation necrosis , congenital deformities and trauma .
the main objectives are to restore chest wall integrity , adequate respiratory function , cover vital structures , obliterate dead space and regaining cosmesis .
although most defects could be repaired with local and regional flaps , more complex cases require increasingly sophisticated surgical techniques .
the authors present the case of a 84-year - old woman , 39 kg of height , body mass index ( bmi ) of 18 kg / m with history of hypertension ( hta ) and right breast cancer , submitted to modified radical mastectomy , axillary dissection and adjuvant thoracic wall radiotherapy about 20 years before ( cobalt therapy , 54 gy , 27 sessions 2 gy / day ) .
she was referred to the plastic surgery department for thoracic wall reconstruction due to an anterior right radiation - induced ulcer , with partial exposure of the 3rd5th ribs and pleura ( fig .
computed tomography ( ct ) confirmed partial osteonecrosis of the 3rd5th ribs and middle third of the sternum .
the surgical planning included debridement and reconstruction of the defect with a pedicled myocutaneous flap .
an ablative surgery was performed , with collaboration of thoracic surgery , including debridement of devitalized soft tissue and partial anterior excision of the right 3rd , 4th and 5th ribs and costal cartilages , and partial sternectomy ; no skeletal stabilization was needed . the resulting defect ( 14 cm 16 cm ; 224 cm ) , presenting osseous and pleural exposure ( with pachypleuritis due to previous radiation ) ( fig .
1b ) was reconstructed with a pedicled omental flap based on right gastroepiploic vessels and covered with expanded split - skin graft ( fig .
definitive histopathological test was negative for malignancy and microbiological tests were also negative . at postoperative day 2 ,
the flap started to show signs of congestion at the distal third , with progressive darkening of the distal portion ( fig . 2c ) .
due to partial flap necrosis , ten days after the first surgery , she underwent a second procedure of debridement and coverage with pedicled contralateral vram ( vertical rectus abdominis myocutaneous ) flap based on superior left epigastric vessels , including a skin island of 5.5 cm 14 cm ; one closed - suction drain was placed under the flap . during the first postoperative night , she had an episode of disorientation and psychomotor agitation , ripped the drain off , and a submuscular hematoma under the flap developed , with progressive signs of partial skin island necrosis ( fig .
she was submitted to a third surgery of partial debridement and first time of reconstruction ( delay ) with pedicled fasciocutaneous deltopectoral flap ( 8 cm 18 cm ) based medially on mammary internal perforators ( fig .
after 3 weeks , she underwent a fourth procedure involving raising and inset of the delayed deltopectoral flap at the remaining thoracic defect .
she was discharged at day 45 , completely healed , oriented to plastic surgery ambulatory .
after 5 months of follow - up , she presents adequate thoracic wall coverage ( fig .
4b ) with no functional restriction , including respiratory function and mobility of the upper limb .
chest wall defects due to radiation therapy continue to represent a complicated treatment scenario for both thoracic and reconstructive surgeons .
although radiation therapy has been highly refined and rendered much safer in the last years , it is still possible to see astonishing associated wounds .
it is also important to determine whether any other local problems such as mediastinal abscess may interfere with the reconstruction . whether or not cancer is present
paramount treatment implies radical excisional surgery and full - thickness reconstruction , which can be roughly divided into an osseous thorax reconstruction and soft tissue reconstruction .. numerous factors can influence the decision regarding which defects require skeletal reconstruction . despite no true consensus in the literature about the size and location of defects that absolutely require reestablishment of the continuity of the bony framework ,
actually , skeletal reconstruction is mostly achieved using alloplastic material for defects involving the resection of 3 or more adjacent ribs or a defect size of more than 5 cm in diameter , despite some authors advocate the use of osseous grafts .
achieving stable soft tissue coverage is also of equal importance , requiring great defects more complex reconstructions than little defects .
the patient presented had a large full - thickness defect of the anterior thoracic wall with exposure of important structures .
due to chronic pachypleuritis and no previous respiratory limitation , despite partial excision of three ribs and great defect dimension , we did not perform skeletal stabilization , with no risk of thoracic volet or respiratory function commitment described .
the fact that no synthetic material was used may also have led to decreased risk of infection .
considering the characteristics of the defect and patient conditions , the first reconstructive option was a regional myocutaneous flap , namely the latissimus dorsi flap , with consistent pedicle , that could achieve satisfactory pleural reconstruction , obliteration of dead space as well as resurfacing the defect , at least , partially .
due to intraoperative findings of fibrosis of the thoracodorsal vessels , the second option was the omental flap , to detriment of other regional muscular flaps .
we have to notice that irradiation has not only effects on ulcer itself , but all the surrounding irradiated tissue so , it is common to find poor healing and vascular pedicle damage , with risk of partial / total necrosis of the transposed muscles . the omental flap can provide tissue that may fit irregular shaped defects with large dimensions , which was the case . due to its potential good microcirculation and phagocytic activity
is particularly indicated in cases of reconstruction of damaged / compromised areas and may eliminate or limit the infection improving circulation of the receiving area , as in this type of injuries .
the main drawback of the omental flap is its potential intra - abdominal morbidity with the laparotomy despite it can also be raised laparoscopically .
it is also difficult to predict the flap size because of lack of direct correlation with the patient 's morphologic characteristics .
after partial omental flap necrosis , we had to take another reconstructive options and decided to perform a rectus abdominis flap , although complicated with partial necrosis , that was managed with a delayed deltopectoral flap , as a salvage procedure for reconstruction .
the patient here presented was an old female , with low bmi , hta , that was submitted to higher doses of radiation therapy 20 years before .
the radiation treatments made in that time were responsible for high collateral tissue damage , since the gamma rays were from cobalt-60 radioisotopes , in two tangential beams , with possible massive uncontrolled destruction of the surrounding tissues , including ribs , sternum and even lungs , and surrounding vasculature .
, in 2013 , retrospectively analyzed 302 tram flap reconstructions , and found that previous chest wall irradiation did not result in increased rate of flap loss , infection , and fat necrosis ; however , there was a trend toward higher revision rate in the previously irradiated tram group . in our case , the type of radiation applied , associated to other patient factors described above resulted in a different outcome .
free microvascular reconstruction was not here considered as a primary option due to patient 's poor conditions ( including advanced age , low bmi associated with some inability to prolonged surgery / icu stay , some periods of confusion and disorientation / poor compliance ) and local / surgical conditions like lack of recipient vessels or need for complex temporary arteriovenous loops / interpositional grafts .. due to the described risks we looked at it as a final option . in similar situations of previous severe chest wall irradiation ,
a correct and exhaustive preoperative assessment should be performed , which can include ct - angiography evaluation or even doppler sonography , in order to evaluate the status of the surrounding vasculature potential vascular pedicles , for decision making on the reconstructive option .
also , in these cases , the venous ( or even arterial ) supercharging of the flaps could be a consideration on the treatment planning in order to avoid flap loss / increase the likelihood of a successful reconstruction .
this case highlights that , despite some good orientation guidelines and algorithms already published , reconstructive choice should be individualized and dependent on patient and local factors such as size of the defect , location on the chest wall , arc of rotation of the flap , and availability of recipient vessels .
the authors advise that surgical team should work closely and be well versed in chest wall reconstruction with a variety of pedicled flaps ( delayed or even combined / multi - staged reconstruction ) and techniques , when a complication occurs .
multi - staged flap reconstruction may have to be used as a salvage procedure for the coverage of complex , great and complicated chest wall defects due to previous radiation therapy .
there was no need for approval by an ethical committee given the type of the article . written informed consent
was obtained from the guardian of the patient for publication of this case report and accompanying images .
a copy of the written consent is available for review by the editor - in - chief of this journal on request .
rita valena - filipe contributed to study design , manuscript writing , decision for publication , case orientation and editing of the final manuscript .
ricardo horta contributed to manuscript writing , data analysis , and editing of the final manuscript .
apolino martins contributed to patient orientation and follow - up , data analysis and interpretation .
lvaro silva contributed to data analysis and final manuscript.key learning pointschest wall reconstruction due to previous radiation therapy can be challenging and complex , requiring a multidisciplinary approach .
radiation thoracic ulcers still occur.a 84-year - old woman with a chest wall ulcer was submitted to an ablative surgery ( full - thickness defect of 224 cm ) , firstly reconstructed with a pedicled omental flap and due to sequential complications , submitted to a multi - staged complex flap reconstruction , with good coverage.reconstructive choice should be individualized and dependent on patient and local factors.the team should be well versed in chest wall reconstruction with a variety of flaps when a complication occurs and when microsurgery can not be considered.multi-staged flap reconstruction may have to be used as a salvage procedure for the coverage of complex , great and complicated chest wall defects due to previous radiation therapy .
key learning pointschest wall reconstruction due to previous radiation therapy can be challenging and complex , requiring a multidisciplinary approach .
radiation thoracic ulcers still occur.a 84-year - old woman with a chest wall ulcer was submitted to an ablative surgery ( full - thickness defect of 224 cm ) , firstly reconstructed with a pedicled omental flap and due to sequential complications , submitted to a multi - staged complex flap reconstruction , with good coverage.reconstructive choice should be individualized and dependent on patient and local factors.the team should be well versed in chest wall reconstruction with a variety of flaps when a complication occurs and when microsurgery can not be considered.multi-staged flap reconstruction may have to be used as a salvage procedure for the coverage of complex , great and complicated chest wall defects due to previous radiation therapy .
chest wall reconstruction due to previous radiation therapy can be challenging and complex , requiring a multidisciplinary approach .
a 84-year - old woman with a chest wall ulcer was submitted to an ablative surgery ( full - thickness defect of 224 cm ) , firstly reconstructed with a pedicled omental flap and due to sequential complications , submitted to a multi - staged complex flap reconstruction , with good coverage .
the team should be well versed in chest wall reconstruction with a variety of flaps when a complication occurs and when microsurgery can not be considered .
multi - staged flap reconstruction may have to be used as a salvage procedure for the coverage of complex , great and complicated chest wall defects due to previous radiation therapy . | ### Summary:
: introductionchest wall reconstruction due to previous radiation therapy can be challenging and complex , requiring a multidisciplinary approach.presentation of casethe authors present the case of a 84-year - old woman with a right chest wall radionecrosis ulcer , that was submitted to an ablative surgery resulting in a full - thickness defect of 224 cm2 , firstly reconstructed with a pedicled omental flap . due to partial flap necrosis ,
other debridements and chest wall multi - staged flap reconstruction were performed.discussionthis case highlights that the reconstructive choice should be individualized and dependent on patient and local factors .
the authors advise that surgical team should work closely and be well versed in chest wall reconstruction with a variety of pedicled flaps , when a complication occurs.conclusiona multi - staged flap reconstruction could be a salvage procedure for the coverage of complex , great and complicated chest wall defects due to previous radiation therapy . |
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: with the beginning of new millennium , while stem cell has been the major issue of the basic medicine , endoscopic submucosal dissection ( esd ) has brought about a renaissance in therapeutic endoscopy .
the procedures that had been performed only by a few pioneers in japan are now , 10 years later , easily accessible at most large centers in japan and korea , and rapidly spreading in the east asia , europe , and the usa .
such rapid growth of esd may be probably explained by the possibility of complete resection ( r0 ) regardless of the tumor size in the gastrointestinal tract1,2 and rapid increase of candidate patients due to the improvement in early detection of tumor .
esd will be the first to be mentioned if there were a noble prize for endoscopy . with the development and improvement of therapeutic techniques and various specialized devices , procedures aimed at gastric tumor
are now performed for treatment of esophageal and colorectal tumors.3 - 8 furthermore , the number of physicians who can perform esd has rapidly increased with general ex vivo and in vivo training using animal models and hand - on courses;9 - 11 esd , that were performed only in japan and korea , is now going through globalization and universalization.12 - 14 several questions may be raised at this point .
what are the new diseases that esd technique could be applied in the next decade ?
these questions are of much concern not only to me but also to many of those who are performing or willing to perform esd , and the focused reviews on the globalization of esd has been planned , in this regard , through the editors meeting of clinical endoscopy .
world - renowned esd experts each introduced two distinct major themes on esd by reviewing the published studies or their own precious experiences .
in fact , esd procedure requires more complicated and accurate techniques than other procedures in the field of therapeutic endoscopy , which is why it is more difficult to learn . in order to attain the stage of performing the procedure in patients , clinicians need to observe more procedures by experts and participate in individualized one on one training using training models .
this review is aimed at introducing published articles so far on esd training using training models and providing an overview on how esd training has been performed in reality .
first , dr . adolfo parra - blanco reviewed on ex vivo and in vivo models for esd training .
he reviewed and clearly summarized studies on esd training published so far , showing that training with animal model is actually very helpful .
he also provided detailed description on what efforts have been made to learn esd in countries without experts on esd and how original ex vivo model for esd training was made .
joo young cho described detailed practical settings and current status of hands - on courses using ex vivo and in vivo models in korea to encourage enforcement of esd training .
he explained how esd training has been performed in practice and what efforts have been made in korea for globalization and universalization of esd .
readers of these perfect and remarkable focused reviews will exclaim " this is it ! " and will be able to make an ex vivo model effortlessly .
this focused review series would be of great value if it could be of any help in developing esd training around the world .
esd technique has become easier and more convenient with the development of various knives , devices , injection fluids , and electro - surgical units for esd , which may be useful to prevent complications and enhance the safety of esd when used properly .
first , quality controlled esd and basic techniques to prevent complications were described by dr .
takashi toyonaga . beyond the conventional wisdom that esd should be performed in a short period of time , the author explains the importance of quality controlled esd for preventing complications and what should be done for this purpose , citing fantastic figures .
tsuneo oyama reviewed recently published methods to facilitate esd , such as position change , clip with line method , external grasping forceps method , and internal traction method .
third , dr . jae - young jang reviewed the usefulness of magnifying and narrow band imaging ( nbi ) to measure the depth of invasion before esd , which is one of the recent hot issues .
this review explained how magnifying and nbi can be used to avoid performing incomplete esd of a lesion and to predict when not to perform it .
esd has been an ambition for me since first encountering it 10 years ago , and planning these focused review series was a great honor to me .
ten years ago , my first question was ' will i be able to perform esd ? ' i hope this focused review series will be of help to the readers of clinical endoscopy and inspire some confidence that they could also learn and perform esd . | ### Summary:
: introduction of endoscopic submucosal dissection ( esd ) has brought about a renaissance in therapeutic endoscopy . for the globalization and universalization of esd
, the number of physicians who can perform esd has rapidly increased with general ex vivo and in vivo training using animal models and hand - on courses . in this focused review series , world - renowned esd experts described the published studies or their own precious experiences about esd training and performing esd with accurate and safe techniques .
first , dr . adolfo parra - blanco reviewed on ex vivo and in vivo models for esd training .
next , dr . joo young cho described detailed practical settings and current status of hands - on courses using ex vivo and in vivo models in korea .
dr .
takashi toyonaga described quality controlled esd and basic techniques to prevent complications .
dr .
tsuneo oyama reviewed recently published methods to facilitate esd .
dr . jae - young jang reviewed the usefulness of magnifying and narrow band imaging to measure the depth of invasion before esd . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: neurilemmoma also known as schwannoma , neurinoma , perineural fibroblastoma and peripheral glioma is a benign tumor of nerve sheath or myelin sheath which are formed by schwann cells . although head and neck region accounts for about 25%48% , this tumor is not very common in the oral cavity . among the intraoral sites , tongue is the most common site of origin . rare sites of occurrence include intrabony lesions usually seen in the posterior mandible . unlike neurofibromas
usually , a slow growing tumor but also associated with rapid growth in some cases .
neurilemmomas , though can occur in cranial , spinal and peripheral nerves , have a strong predilection for sensory nerves as they have a thick layer of myelin sheath .
these tumors do not show any sex predilection and are usually found in young- and middle - aged persons .
the more organized and distinctive pattern is the antoni a pattern , where the schwann cells are arranged in palisaded clusters .
the antoni b pattern comprises an irregular arrangement of schwann cells in a loose stroma with small vacuoles .
such tumors are termed as ancient schwannomas and are seldom associated with small intraoral tumors . although controversial neurilemmomas have been shown to undergo malignant transformation .
excision is the treatment of choice and is associated with nearly 100% cure rate , and the tumor does not recur . in our case , unlike the usual presentation , the tumor showed a rapid growth in a relatively less common site , the lower labial mucosa .
a 16-year - old girl reported to the department of oral and maxillofacial surgery , sri ramachandra medical centre with complaints of a swelling associated with pain in the left lower lip region for a duration of 1 month .
detailed history taking revealed that the patient has the habit of lip biting since childhood .
the patient was apparently normal 1 month back after which she developed a small swelling on her lower lip which rapidly progressed over a period of 2 weeks .
pain was present only when there was accidental irritation to the swelling . on inspection , the swelling was present as a pedunculated growth on the left lower labial mucosa in relation to 33 , 34 and 35 .
intraoral view showing the tumor in the left lower lip on palpation , the swelling was firm in consistency associated with tenderness , freely mobile and attached to the underlying tissue through a peduncle . based on this clinical examination and history taking , a provisional diagnosis of traumatic fibroma was made and was planned for an excisional biopsy of the lesion .
the surgical procedure was performed under local anesthesia after obtaining the informed consent of the patient .
the peduncle was ligated with the help of silk ties to avoid any hemorrhage [ figure 2 ] .
the lesion in - toto was excised from the underlying tissue [ figure 3 ] .
ligation of the peduncle surgical site postexcision showing the defect the excised lesion was fixed in 10% buffered formaldehyde solution .
the obtained sections were observed under a light microscope in 4 , 20 and 40 magnifications . at 4 magnification ,
the mounted specimen showed spindle cells dispersed in connective tissue stroma [ figure 6 ] . at 20 magnification ,
the specimen showed streaming fascicles of spindle - shaped schwann cells with wavy nuclei [ figure 7 ] .
the verocay bodies , which are the palisaded arrangement of nuclei around a central acellular eosinophilic area , were also noted at 40 magnification [ figure 8 ] .
spindle cells dispersed in connective stroma ( h&e , 4 ) streaming fascicles of spindle - shaped schwann cells having wavy nuclei ( h&e , 20 ) antoni a : cellular region - nuclei palisaded arrangement around central acellular eosinophilic areas - verocay bodies ( h&e , 40 ) based on the above said histopathological findings , a final diagnosis of conventional schwannoma was given .
excision of the lesion had already been done , and the patient was followed up for 6 months without any evidence of recurrence .
initially termed as neurinoma in the year 1910 by verocay , later , the term neurilemmoma was coined in the year 1935 by stout .
now , commonly referred to as schwannomas after the term was coined by masson in 1932 , these tumors of neurogenic origin are usually benign and seldom show malignant transformation .
neurilemmomas most frequently occur along the course of the vestibulocochlear nerve , followed by scalp , face , pharynx , parotid gland , middle ear and external acoustic canal .
oral cavity accounts for only about 1% of all these neurogenic tumors , with the mobile tongue being the most common site of origin .
the other intraoral sites include floor of the mouth , palate , mental nerve trunk , gingiva , buccal mucosa and lip .
wright and jackson analyzed 146 cases of intraoral neurilemmomas and found tongue accounts for 52% of the cases , followed by buccal mucosa and mucosa of gingiva and lip accounting for 19.8% and 19.24% of the cases , respectively , and the least being soft palate with 8.9% .
gallo et al . studied 157 cases and found a result similar to that of wright and jackson , with 45.2% of their cases involving the tongue and 13.3% involving the buccal mucosa .
gupta et al . in their study on 136 cases of neurilemmoma of the head and
neck region found the neck to be the most common site with sixty cases , followed by parotid gland with ten cases . in the intraoral region ,
buccal mucosa accounted for nine cases and eight cases each in the tongue and pharynx .
analyzed 49 cases of neurilemmoma found 18 of those tumors were in the neck followed by 11 cases in the tongue .
however , in case of intraosseous tumors , where mandible is the most common site of origin , pain , paresthesia and bony expansion are not uncommon .
neurilemmoma can affect individuals of all age groups but most commonly found in the 2 and 3 decades of life .
william et al . in his study found a strong predilection for males , while lucas found a greater predilection for females .
hatziotia and asprides and enzinger and weiss in their studies found an equal sex predilection .
the common differential diagnosis of intraoral neurilemmomas according to wright and jackson include cysts such as epidermoid and dermoid cysts or tumors such as lipomas , hemangiomas , granular cell tumor , leiomyoma and lymphangioma .
conventional schwannomas are the most common variants and large old tumors with nuclear atypia are termed as ancient schwannomas and are a subtype of conventional schwannoma . according to woodruff , although rare , only the conventional type undergoes malignant transformation .
cellular schwannoma first described by woodruff in 1981 , is a more recently described variant which shows histological similarity to malignant peripheral nerve sheath tumors because of the disorderly pattern of arrangement of spindle cells .
the small cutaneous tumors might not show the exact architecture of the lesion , whereas larger lesions are firm , multinodular and consist of worm - like components .
the melanotic variant is the rarest among the four and usually involves the spinal nerves and the paraspinal ganglia .
unlike the normal clinical presentation of a slow growing tumor , our case showed a rapid progression over a period of 1 month misleading us to give the first provisional diagnosis of traumatic fibroma as it was associated with a parafunctional habit .
dentists should be aware of this rare benign neoplasm which might mimic as other common benign neoplasms .
still , this particular benign lesion has very minimal chance of recurrence and cases of malignant transformation have also been reported .
| ### Summary:
: neurilemmoma , neurinoma or schwannoma is a benign tumor of neurogenic origin , arising from the myelin sheath of a neuron .
head and neck region accounts for 25%48% of these tumors reported till date . on the contrary ,
intraoral sites form only 1% of the cases accounted .
although a few cases of intraoral neurilemoma of mental nerve has been reported in english literature , none has been reported to arise from the terminal fibers of the mental nerve . in this particular article , we present a case were the tumor was noted in the lower labial mucosa . |
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: a pilot study was conducted with 11 diabetic hypothyroidpatients who were on stable l - t4 substitution ( average dose 89.8 11.5 g / day ) to examine the short- to mid - term ( up to 24 weeks ) effects of metformin administration .
serum tsh , free t4 ( ft4 ) , free t3 ( ft3 ) , total t4 ( tt4 ) , and total t3 ( tt3 ) were measured at baseline and 6 , 24 , and 72 h after starting metformin treatment , as well as after 3 and 6 months of therapy .
a second study was performed in a larger cohort of diabetic patients including 29 euthyroid patients on l - t4 substitution ( group i ) , 18 subclinical hypothyroid patients who did not receive l - t4 treatment ( group ii ) , and 54 euthyroid patients in whom thyroid disorders had been excluded by a complete thyroid workup based on clinical history , physical examination , measurement of serum ft4 , ft3 , tsh , tg - ab , and tpo - ab , as well as thyroid ultrasonography ( group iii ) .
type 2 diabetes was diagnosed in accordance with american diabetes association criteria ( 9 ) .
all subjects gave their informed consent to the study , which was performed in accordance with the declaration of helsinki .
between- and within - group comparisons were performed by an anova general linear model , including repeated - measures analysis ( spss version 13 ; spss , evanston , il ) .
between- and within - group comparisons were performed by an anova general linear model , including repeated - measures analysis ( spss version 13 ; spss , evanston , il ) .
there were no changes of ft4 , ft3 , tt4 , and tt3 observed throughout the study .
overall , a modest reduction of baseline tsh values ( from 2.11 0.55 to 1.5 0.36 miu / l , ns ) was observed after 6 months of metformin treatment ; however , one patient showed tsh reduction from 0.5 to 0.09 miu / l and stable values of ft4 ( from 13.3 to 12.9 pg / ml ) , ft3 ( from 3.12 to 2.92 pg / ml ) , tt4 ( from 10.7 to 10.2 g / dl ) , and tt3 ( from 1.07 to 1.04 ng / ml ) .
withdrawal of metformin in this patient led to an increase of tsh level , which returned to the baseline ( pre - metformin ) level within 3 months .
clinical characteristics and most relevant data in the three groups of patients are summarized in table 1 .
a significant decrease of tsh levels after 1 year of metformin treatment was observed in group i and group ii subjects but not in group iii subjects . in detail , mean tsh level was significantly reduced after 1 year on metformin in group i , from 2.37 1.17
furthermore , six patients in this group ( 20.7% ) showed a serum tsh level lower than normal 1 year after starting metformin .
demographic , drug treatment , and thyroid function data in the three groups of diabetic subjects noncategorical data are means sd .
between - group differences : * p < 0.001 for group i vs. group iii .
mean basal tsh level in patients of group ii was 4.5 0.37 miu / l and significantly decreased to 2.93 1.48 after 1 year of metformin ( p < 0.001 ) ; tsh reduction never reached subnormal levels in individual patients of this group .
serum ft4 levels did not significantly change during metformin treatments in any group ( table 1 ) .
there were no changes of ft4 , ft3 , tt4 , and tt3 observed throughout the study .
overall , a modest reduction of baseline tsh values ( from 2.11 0.55 to 1.5 0.36 miu / l , ns ) was observed after 6 months of metformin treatment ; however , one patient showed tsh reduction from 0.5 to 0.09 miu / l and stable values of ft4 ( from 13.3 to 12.9 pg / ml ) , ft3 ( from 3.12 to 2.92 pg / ml ) , tt4 ( from 10.7 to 10.2 g / dl ) , and tt3 ( from 1.07 to 1.04 ng / ml ) .
withdrawal of metformin in this patient led to an increase of tsh level , which returned to the baseline ( pre - metformin ) level within 3 months .
clinical characteristics and most relevant data in the three groups of patients are summarized in table 1 .
a significant decrease of tsh levels after 1 year of metformin treatment was observed in group i and group ii subjects but not in group iii subjects . in detail , mean tsh level was significantly reduced after 1 year on metformin in group i , from 2.37 1.17 miu / l at baseline to 1.41 1.21 ( p < 0.001 ) .
furthermore , six patients in this group ( 20.7% ) showed a serum tsh level lower than normal 1 year after starting metformin .
demographic , drug treatment , and thyroid function data in the three groups of diabetic subjects noncategorical data are means sd .
between - group differences : * p < 0.001 for group i vs. group iii .
mean basal tsh level in patients of group ii was 4.5 0.37 miu / l and significantly decreased to 2.93 1.48 after 1 year of metformin ( p < 0.001 ) ; tsh reduction never reached subnormal levels in individual patients of this group .
serum ft4 levels did not significantly change during metformin treatments in any group ( table 1 ) .
the results of this study showed that 1 ) the initiation of treatment with metformin was associated with a significant reduction in the serum levels of tsh in diabetic patients with primary hypothyroidism both with l - t4 replacement therapy and untreated ; 2 ) tsh reduction was not associated with reciprocal changes in any other thyroid function parameter ; 3 ) the tsh - lowering effect of metformin developed slowly and was detectable after a few months of treatment ; and 4 ) metformin had no effect on circulating thyroid function parameters in euthyroid diabetic patients .
these data indicate that the thyroidal repercussion of metformin administration in diabetic patients may be dual : although no effect is detectable in patients with a normal pituitary - thyroidaxis , significant changes do occur in patients with an underlining thyroid deficiency , both with l - t4 therapy and untreated .
this is a clinically relevant observation , especially when considering that hypothyroidism occurs in 1015% of type 2 diabetic patients ( 8) and many of them are presumably also treated with metformin .
the mechanism(s ) by which metformin lowers tsh level is still unclear , and the design of the present study does not allow drawing causal inferences .
however , the present data would exclude biological interferences of metformin with the tsh assay , increased l - t4 absorption from the gastrointestinal tract , or any influence of changes in body weight associated with metformin treatment .
we hypothesize that metformin may enhance the inhibitory modulation of thyroid hormones on central tsh secretion .
such an effect would not modify circulating ft3 or tsh levels when the closed - loop control system is normally functioning , but may well explain the reduction of circulating tsh levels observed in subjects with altered thyroid - hypophyseal feedback .
another explanatory hypothesis could be that metformin ameliorates the thyroid function reserve in those patients with hypothyroidism both treated and untreated .
future studies will be needed to fully elucidate the mechanisms of the here - described tsh - lowering effect of metformin . in conclusion ,
the results of this study show that metformin administration in diabetic patients with hypothyroidism , both with l - t4 therapy and untreated , is associated with a significant reduction in the serum levels of tsh , with no change in ft4 .
a major clinically relevant consequence of our findings is that a reevaluation of thyroid function within 612 months after starting metformin seems necessary in diabetic patients with concomitant hypothyroidism . | ### Summary:
: objectiveto assess the interplay between metformin treatment and thyroid function in type 2 diabetic patients.research design and methodsthe acute and long - term effects of metformin on thyroid axis hormones were assessed in diabetic patients with primary hypothyroidism who were either untreated or treated with levothyroxine ( l - t4 ) , as well as in diabetic patients with normal thyroid function.resultsno acute changes were found in 11 patients with treated hypothyroidism .
after 1 year of metformin administration , a significant thyrotropin ( tsh ) decrease ( p <
0.001 ) was observed in diabetic subjects with hypothyroidism who were either treated ( n = 29 ; from 2.37 1.17 to 1.41 1.21 miu / l ) or untreated ( n = 18 ; 4.5 0.37 vs. 2.93 1.48 ) with l - t4 , but not in 54 euthyroid subjects .
no significant change in free t4 ( ft4 ) was observed in any group.conclusionsmetformin administration influences tsh without change of ft4 in patients with type 2 diabetes and concomitant hypothyroidism .
the need for reevaluation of thyroid function in these patients within 612 months after starting metformin is indicated . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: if surgical treatment is not applicable , an aaa progresses to rupture with a high mortality rate and causes 1%3% of elderly male deaths in developed countries each year .
analysis of the aneurysmal wall has demonstrated that connective tissue degradation , increased atherosclerosis , and chronic inflammation are the common pathological features of aaas [ 13 ] .
sphingosine-1-phosphate ( s1p ) is a newly discovered low - molecular - weight zwitterionic lysophospholipid molecule that is generated from the metabolism of sphingomyelin by a series of enzymes including sphingosine kinase , s1p phosphatase , and s1p lyase in mammals .
the main sources of s1p are platelet cells in plasma , while other cell types such as erythrocytes , neutrophils , and mononuclear cells can also produce and release s1p upon activation [ 4 , 5 ] .
s1p exerts a wide range of physiological activities , particularly inflammatory reactions through the interactions with five different receptor subtypes 1 , 2 , 3 , 4 , and 5 .
they are the members of the endothelial differentiation gene family of g protein - coupled receptors , and differential expressions of s1p receptors are thought to modulate the cellular inflammatory response .
a precise s1p / s1p receptor balance is found to be responsible for the signaling of cell growth and regulation of cell metabolism in mammal [ 7 , 8 ] .
an imbalance of this system also participates in pathologic conditions such as cancer and inflammatory diseases [ 9 , 10 ] .
s1p2 is the major expressed s1p receptor , while s1p1 or s1p3 is only weakly expressed in healthy vascular endothelial cells and vascular smooth muscle cells ( vsmcs ) . consistently with this receptor multiplicity and pleiotropic signaling mechanisms , s1p receptors influence numerous cell functions .
particularly , differential expressions of s1p receptors have been demonstrated to either promote or inhibit the inflammatory infiltration in diverse cell types by inducing cyclooxygenase 2 ( cox-2 ) expression with subsequent prostaglandin e2 ( pge2 ) or prostacyclin ( pgi2 ) production [ 1315 ] .
our previous study showed that inflammatory mediators such as cox-2 and prostaglandin e2 are also widely expressed in aaa explants .
s1p1 , s1p2 , and s1p3 receptors are the major s1p receptor subtypes in the vascular system [ 11 , 12 ]
. however , the expressions of these three s1p receptors in aaa remain unknown . in the present study
, we aimed to investigate the s1p1 , 2 and 3 receptor protein expressions in aaas and compare them with healthy aortas .
cross - sections of aneurysm wall , which were dissected of luminal thrombus , were removed from the aaa patients who underwent open surgical aneurysmal repair in a local hospital .
control aortic tissues were obtained from the corresponding location of healthy organ donors without known cardiovascular diseases and connective tissue disorders during the transplant operation .
aneurysmal patients with the marfan syndrome and other connective tissue disorders were excluded from this study .
each collected specimen was thoroughly washed with normal saline solution , and then the tunica intima elimination procedure was conducted using a scalpel and forceps .
all specimens were divided into two parts for the western blotting which was kept in a 80c freezer and immunohistochemical analysis , respectively .
frozen tissues were first thawed and then lysed with cell lysis buffer ( cell signaling .
technology , danvers , ma , usa ) containing protease inhibitor ( roche , basel , switzerland ) .
the protein concentration of each specimen was measured based on the bradford method utilizing the bio - rad protein assay kit ( bio - rad laboratories , hercules , ca , usa ) with bovine serum albumin ( bsa ) as the standard .
after the protein denaturing procedure with loading buffer ( ph 6.8 24 mm tris - hcl , 684 mm glycerol , 14 mm sds , 142 mm beta - mercaptoethanol , 0.3 mm bromophenol blue ) , each sample ( 50 g ) was resolved on 12% sds - polyacrylamide gel electrophoresis ( page ) gel ( bio - rad laboratories ) at room temperature then transferred onto a polyvinylidene fluoride ( pvdf ) membrane ( bio - rad laboratories ) at 4c . after blocking in 10% tbs0.01% tween 20 ( tbst ) diluting nonfatty milk ( bio - rad laboratories ) for two hours at room temperature
, the membranes were then incubated overnight at 4c with primary antibodies against s1p1 receptor ( catalogue no .
sc-48356 , dilution 1 : 100 , santa cruz biotechnology , santa cruz , ca , usa ) or s1p2 receptor ( catalogue no . sc-25491 , dilution 1 : 200 , santa cruz biotechnology ) or s1p3 receptor ( catalogue no .
sc-30024 , dilution 1 : 100 , santa cruz biotechnology ) with gapdh ( 1 : 1000 , cell signaling technology ) as the positive control . after membrane washing using tbst solution , hrp - conjugated goat anti - mouse (
1 : 2000 ) or goat anti - rabbit ( 1 : 4000 ) secondary antibody ( dako , glostrup , denmark ) was added and the membranes were then incubated for 1 hour at room temperature .
after washing , signals were visualized by luminol reagents ( bio - rad laboratories ) and the densitometry of each exposing blotting was analyzed by imagej 1.44 software ( national institutes of health , bethesda , md , usa ) .
the relative expression of the studied receptors ' protein was calculated by the detected signal divided by the internal positive control ( gapdh ) expression signal in each sample .
the staining procedure was performed on paraffin - embedded aortic tissue ( 5 m ) sections according to the manufacturer 's instructions ( dakocytomation envision + system - hrp ( dab ) kit ( dako ) ) . specificity of s1p receptor antibodies was firstly validated by positive and negative tests using healthy adult rat brain paraffin sections .
briefly , all sections were antigen retrieved with boiling sodium citrate buffer ( ph 6 ) and incubated with either mouse anti - s1p1 receptor antibody ( 1 : 25 ) , rabbit anti - s1p2 receptor antibody ( 1 : 100 ) , or rabbit anti - s1p3 receptor antibody ( 1 : 100 ) ( santa cruz biotechnology ) overnight at 4c .
after staining , all specimens were subjected to the dehydration procedure and sealed for microscopy observation . to avoid staining underestimation due to considerable regional variations , 5 continuous 200 microscopy views of each stained specimen , which had the largest amount of positive stained vsmcs ,
two researchers scored the positive immunostaining using the scoring system according to the wang and colleagues study .
briefly , a proportion subscore from 0 to 4 ( i.e. , 00% positive stained , 11%25% positive stained , 226%50% positive stained , 351%75% positive stained , 476%100% positive stained ) and an intensity subscore from 0 to 3 ( i.e. , 0 : no staining , 1 : weak staining , 2 : moderate staining , 3 : intense staining ) were first assigned by each observer for each slide .
a weighted score was then determined by multiplying the proportion subscore and the intensity subscore .
finally , a mean value of the five weighted scores for each specimen was calculated .
statistical analysis was performed by spss 18.0 software ( spss , chicago , il , usa ) .
any statistical differences between the two groups ' experimental results were determined by independent sample t - tests .
correction for ages and sex of patients on receptor expression levels were made using a linear model . a p value < 0.05 was considered as statistically significant .
there were 40 aaa specimens and 20 control aortas obtained from the corresponding surgical patients and organ donors .
most of patients were male , and the control patients were younger than the aaa patients .
s1p1 receptor protein ( 38 kda ) was undetectable in both tissues ( figure 1(a ) ) .
for s1p2 receptor protein ( 45 kda ) , positive signals were detected in both aaa and control aortic tissues , with aaa tissues had a significantly lower protein expression level compared with control aortas ( figure 1(b ) ) .
in contrast , s1p3 receptor protein ( 45 kda ) was highly expressed in aaa aortas but was undetectable in control aortas ( figure 1(c ) ) .
the relative intensities of s1p1 and 2 receptors expression by western blot analysis are shown in figure 2 upper and lower panels , respectively .
the protein level of s1p2 receptor was decreased by 73% ( p < 0.05 ) in the aaa tissues ( mean relative intensity of 0.29 ) compared with the control aortic tissues ( mean relative intensity of 1.08 ) .
s1pr3 protein levels were significantly upregulated in aaa tissues with average relative intensity of 0.65 , whereas it was undetectable in normal aortas .
s1p1 receptor expression level was undetectable in both aaa ( a ) and normal aortas ( b ) , as shown in figure 3 .
a positive control of s1p1 receptor was performed in healthy adult rat brain for validating its specificity ( figure 3(c ) ) .
s1p2 receptor protein was expressed in both types of aortas , with pronounced s1p2 receptor staining observed in control aortas ( figure 4 ) .
s1p3 receptor protein was found in the aaa tissues ( figure 5(a ) ) , but it was almost undetectable in normal aortas ( figure 5(b ) ) .
positive staining of s1p2 and s1p3 receptors in the aortic walls showed that they were localized in vsmc plasma membrane and cytoplasm but absent in the nucleus ( figures 4 and 5 ) . giving the age and sex discrepancy existed in the patients , corrections for ages and sex of the receptor protein expressions was made .
the association between s1p2 and s1p3 protein ( both ihc and wb expression levels ) in the patients were robust to correction in a linear model with age and sex ( p < 0.008 ) .
among the studied s1p receptors , only s1p2 and s1p3 receptor proteins were differentially expressed in aaa tissues compared with the control aortas , while s1p1 receptor protein was absent in both types of tissues .
differential s1p receptors expressions have been shown to participate in diverse physiological processes , such as cell survival and apoptosis , and pathological processes , such as angiogenesis , inflammation , cancerogenesis , and immune regulation .
thus , the present novel findings may implicate the importance of these receptors in the inflammation attribute to aaa pathogenesis .
nevertheless , atherosclerosis is indeed regarded as a chronic inflammatory disease with atherosclerotic plaques containing inflammatory infiltrates , which implicated in the formation of aaa .
thus , the possibility of s1p receptor expression related to the atherosclerotic event can not be excluded .
other researchers found that only some specific cell types , such as endothelial cells , cardiomyocytes , neural stem cells , as well as b cells , and t cells , express marked s1p1 .
healthy rat adults ' vsmcs express s1p1 receptor weakly , and the deletion of s1p1 receptor is embryonically lethal since it causes the failure of dorsal migration of vsmcs to form the tunica media layer of arteries , suggesting that s1p1 receptor should be critical in vascular development rather than in maintaining vsmcs metabolism . a more recent study suggested that s1p1 is involved in the phenotype regulation of adult smooth muscle cells .
they utilized a rat carotid artery balloon injury model and demonstrated that there was a transient over expression and activation of s1p1 receptor after injury .
however , such s1p1 receptor over expression will be restored to the basal value by 7 days after injury , suggesting that this irritable s1p1 receptor activation may be a short - term injury response .
thus , we postulated that the s1p1 receptor protein may be transiently increased during early aaa lesion , but its high expression will subsequently return to the basal level or become undetectable at the advanced stage of aaa development .
in addition , s1p1 receptor is possibly responsible for the development of circulation system and expressed in the endothelial cells , rather than expressed in smooth muscle cells in mature aortas which may explain for absent of s1p1 levels in the late stages of aneurysm .
s1p2 receptor protein was detected in both types of aortic tissues , particularly in control aortas .
indeed , s1p2 receptor has been previously shown to be the major s1p receptor expressing population in a wide variety of tissues in humans , like vascular endothelial and smooth muscle cells , but not in inflammatory infiltrates . this particular receptor can facilitate vsmcs ' contractile phenotype expressions and negatively regulate their proliferation and migration .
moreover , s1p2 receptor is capable of inducing cox-2 expression and producing prostacyclin ( pgi2 ) in response to exogenous s1p stimulus [ 15 , 23 , 24 ] .
pgi2 possesses anti - inflammatory functions and simultaneously relaxes vsmcs and suppresses their proliferation and migration .
thus , the decreased expression of anti - inflammatory s1p2 receptor in vsmcs of aaas , and probably not expressed in the inflammatory infiltrates , may impair the production of pgi2 and ultimately lead to the pronounced inflammation response in aaa patients .
therefore , the s1p2 receptor downregulation of vsmcs is obviously an important etiological factor in aaa development .
s1p3 receptor possesses a promoting inflammatory response property as it can induce cox-2 expression and concomitant pge2 production in various cell types [ 13 , 14 , 26 , 27 ] . as a pronounced inflammatory infiltrate
, pge2 was also found in aaa explants in our laboratory previously though the extent of its involvement in vascular inflammation is still unclear .
in addition , a very recent study suggested that s1p3 mediates the chemotactic effect of its ligand - s1p in macrophages in vitro and in vivo , which plays a crucial role in atherosclerosis by promoting inflammatory monocyte / macrophage recruitment and altering smooth muscle cell behavior .
we suggested that the s1p3 receptor protein may be critical in the strengthened inflammatory response and thus atheroslcerosis via the chemotactic property and the pge2 pathway during aaa development .
however , the causal relationship between the inflammatory cells recruitment and the prostaglandins needed to be further explored . in the present study , a weak s1p3 staining signal was found in normal aortas , though it became undetectable using western blot analysis .
though age and sex discrepancy existed in the studied patients , the present analysis found that the expression of the s1p2 and 3 receptor proteins are not age and sex dependent .
thus , the up- or downregulated receptor probably related to the inflammatory cascade underlying the aaa pathogenesis but is not simply a feature of aging or sex difference .
the limitation of the present study is only an observational analysis on surgical aneurysmal aortas .
thus , we can not extrapolate the observations to the initiation or promotion of aneurysm formation .
nevertheless , the present work has provided evidence that aneurysmal aortic tissue exhibits a decreased activity of s1p2 and enhanced s1p3 receptor , which may contribute to the inflammation of aortic walls involved in aaa pathology .
our findings of the differential expression of s1p receptors in aaa compared with normal aortas are novel and may be helpful to delineate the important inflammatory mechanisms in aaa development .
this investigation has provided a new concept in the inflammatory response in the lesions , and the regulation of s1p receptor via s1p2 and s1p3 may open a new regime for aaa treatment in the future . | ### Summary:
: objective . inflammation plays a key role in the pathophysiology of abdominal aortic aneurysms ( aaas ) .
newly discovered sphingosine-1-phosphate receptors ( s1p receptors ) are critical in modulating inflammatory response via prostaglandin production .
the aim of the current study was to investigate the expression of different s1p receptors in aaas and compared with normal aortas at the protein level .
materials and methods .
aortic specimens were harvested during aortic reconstructive surgery for the aaa group or during organ transplant for the control group .
the protein expression of s1p1 , 2 and 3 in aaas and normal aortas was assessed by western blotting and immunohistochemical analysis .
results .
there were 40 aaas and 20 control aortas collected for the receptor analysis . for western blot analysis ,
s1p1 expression was not detected in either group ; s1p2 protein was constitutively detected in both types of aortas but its expression level was significantly decreased
by 73% ( p < 0.05 ) in aaas compared with the control group . in contrast , strong s1p3 expression was detected in aaas aortas but not in normal aortas .
immumohistochemical staining showed
similar results , except a weak s1p3 signal was detectable in normal aortas .
conclusions .
western blot and staining results consistently showed the down - regulation of the s1p2 protein with simultaneous up - regulation of the s1p3 protein in aaas .
since those newly discovered receptors play an important role in the inflammatory cascade , the modulating of s1p signaling , particularly via s1p2 and s1p3 , could represent novel therapeutic targets in future aaa treatments . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the current nutritional habits of children and teenagers can have harmful effects on their health .
the most often nutritional errors observed in these age groups refer to the exaggerated consumption of alcoholic drinks and fast - food products , which are detrimental to fresh vegetables and fruit , to other products rich in nutritional fibres , dairy products , and other products rich in calcium .
studies have proven that breakfast significantly contributes to a complete diet ; persons who eat breakfast more often provide a balanced diet for themselves , both from energetic point of view , and from the point of view of the contribution of macronutrients , micronutrients and dietary fibres . in the case of school children ,
the benefits of breakfast are even more obvious : providing an optimal contribution of catalytic and calorigenic nutrients which are necessary for growth and development , maintaining normal ponderability , improving school performances , . in this context
, our study has proposed to assess the quality of morning eating ( breakfast and snack ) in children from elementary grades , especially that , in accordance with the emergency ordinance no .
16/2003 , as further completed , pupils from 1st-8th grades from state education as well as pre - school children from state kindergartens with normal 4-hour schedule , received dairy and bakery products for free .
our study included 220 children with ages between 8 and 10 years , pupils from 3rd and 4th grades from cities ( u ) and villages ( r ) .
they were asked to answer a questionnaire with 24 items regarding their morning diet ; questions referred to aspects regarding the hours they eat breakfast / morning snack and the products they eat ( including the consumption of dairy and bakery products given in accordance with the emergency governmental ordinance 96/2002 ) , aiming at revealing the characteristics of these nutritional habits during the week and during free days ( on saturdays and on sundays ) . in order to determine the nutrition state of the children in the group , the body mass index ( bmi )
was determined based on the two somatometric indicators ( height and weight ) measured by the employees of the school medical consulting room / family medicine consulting room during the examinations .
pupils health state was also determined by the school / family physician of studied communities .
the teachers coordinating the activity of the pupils from the classes included in the research provided us information regarding the family social and economic status and school performance of the studied pupils .
the statistic processing of results was made by determining the x test and pearson correlation coefficient .
tables 1 and 2 render the structure of the batch of students included in the study taking into consideration their gender and residence environment , parental educational level respectively .
we notice the relatively homogeneous structure of the batch regarding subjects gender and residence environment . in return , by considering parents training level , we get unbalanced sub - batches from numeric point of view
most of the pupils ( 80 % ) come from parents with an average training level .
statistical distribution of the pupils according to the gender and the residence environment our attention is drawn by a case met in rural areas , where only two children live in an intellectual familial environment ; other 20 children ( 21.70 % ) seem deprived of a familial support in their school education , belonging to families whose educational level is minimum or even zero .
the statistic processing of the answers given by pupils to the questions of our questionnaire suggested several aspects that have especially drawn our attention .
, a number of 20 children ( 9.1 % ) 12 from sub - batch u and 8 from sub - batch r do not eat breakfast or the 10 oclock snack , the first food products being eaten after noon , when the child comes back home , after finishing school classes . in other words ,
these pupils do not have any energetic and nutritional contribution during school hours , when their neuro - psychic demands are maximum .
this is even more worrying , as it is most often seen in children with parents that have higher studies , who we expect to be more aware on the importance of little pupils morning meals ( figure 1 ) : 10 of these children ( 50 % ) leave home without having breakfast , and only 20% of them eat something during a break ; the other 30% indicate the lack of nutrition during mornings .
this suggests the idea that solving professional problems by parents ( in order to get incomes that allow high living standards ) becomes primary in relation to other domestic tasks , including supervising the eating habits of the child .
this possibility seems to be supported by the conclusion that at weekends , when parents are no longer / are less involved in their professional activity , all the 10 children have breakfast in the family .
statistical distribution of the pupils according to the food ingestion during the morning and to the educational level of their parents at the same time , we do not have to neglect the fact that many of the children coming from modest families from social and economic point of view eat the croissant and milk offered for free to the pupils from state education ( according to the emergency governmental ordinance 96/2002 ) , products that pupils coming from families of intellectuals eat rarely ( an aspect that we will discuss later ) .
we could therefore explain the lower percentage of pupils coming from modest families from social and economic point of view that have no meal in the morning : in reality , it is not their parents concern , but rather the concern of governmental institutions that could be responsible for the presence of a snack in the morning in the case of children coming from disadvantaged families .
2 . during school days , the structure of pupils morning meal is dominated by the consumption of slices of bread and margarine , salami , jam or cheese and tea ( figures 2 and 3 ) .
very few children drink milk or eat dairy derivatives ( yoghurt ) , as they come from families with higher / average education level or from families from rural areas , where milk is basic food , taking into consideration that animals are raised in their own households ( p<0.01 ) .
besides the reduced consumption of this category of nutritional products ( the main calcium source of the body , also providing the optimal conditions for its absorption ) , we notice the absence of eggs ( the best source of proteins ) and vegetables and fruit basically the main source of vitamin c as well as other numerous vitamins and mineral elements necessary in a balanced nutrition .
statistical distribution of the pupils according to the structure of the breakfast in schooldays and to the educational level of their parents statistical distribution of the pupils according to the structure of the breakfast in schooldays and to the residence environment the structure of morning meals on saturdays and sundays is not very different from the one we have already mentioned : slices of bread and butter are this time as well first in children s breakfast .
we notice a higher consumption of dairy derivatives ( p<0.01 ) , as well as the preference for eggs ( mainly in rural areas , where eggs come from their own household 45.65 % vs. 29.69 % , p<0.01 ) , and cooked meals ( 15.22 % vs. 17.19 % ) .
the answers given by children to the questions regarding the consumption of dairy and bakery products given according to the governmental emergency ordinance 96/2002 have led to the results presented in figures 4 and 5 .
the croissant the most frequently distributed bakery product among pupils is eaten daily only by 35.94 % of the pupils from urban areas and by 43.48% of the pupils from rural areas .
often , the croissant which is left uneaten is offered to the classmates / family members ( little brothers or sisters or grandparents ) or it is used for preparing sandwiches in the family .
biscuits ( bakery products sometimes offered as substitutes for croissants ) have had a bigger success among children , being eaten by 57.81 % vs. 80.43 % of the subjects .
the situation is similar in the case of milk as well the dairy product most frequently distributed among pupils ; it is drunk daily by even smaller percentages of children 15.63 % of the pupils from urban areas and by 28.26 % of the pupils from rural areas . in this case
as well , the milk which is not drunk is offered to classmates or to family members or it is used for making cakes . when it is provided as a substitute for milk ,
sour cream has been appreciated more by children , being eaten by 92.18 % , 86.95 % respectively of the subjects .
consumption in schooldays and to the residence environment statistical distribution of the pupils according to the milk consumption in schooldays and to the residence environment the calculation of bmi has identified the presence of three overweighed children in the batch , without their answers to the questionnaire reveal significant differences between their nutritional preferences and the preferences of the other subjects .
the determination of pupils health state based on the primary records from school consulting rooms/ family medicine consulting rooms has indicated a good health state of subjects , mortality rate being within the average ranges for this age group .
our study has not revealed any statistic correlations between the quality of morning nutrition and school performances of the subjects included in the study .
in our batch , 9.1 % of the pupils take part in the instructive - educative process in the morning without eating breakfast or a snack during breaks .
although our results do not indicated significant alterations of school performances or of these pupils health state , the health related potential of eating breakfast for pupils can not be neglected .
it is very important that the meals in the morning provide children an energetic and nutritive contribution adequate to their age , a contribution provided by whole cereals , fresh fruit and vegetables , dairy products and meat products with low content of lipids .
breakfast has to be considered an important part within a global preventive strategy meant to reduce the risks for children and teenagers health .
along with healthy nutrition , this strategy has to include the decrease / removal of other components of their living style that could have a negative impact on their health ( the consumption of cigarettes and alcohol , sedentariness , etc ) . | ### Summary:
: the purpose of the study was to evaluate the quality of morning nutrition of children in primary school , related to the residence environment and the family educational level .
we included in our study 220 children in the age group 8 - 10 , studying in urban and rural schools .
they answered a 24-itemed questionnaire regarding their morning nutrition .
nutrition state , health state and school performance were evaluated .
we found that 9.1% of all the children skip breakfast and midmorning snack .
most frequently they have margarine , salami , jam or cheese sandwiches and tea as breakfast . the free milk and roll
are daily consumed by less than 45 % of the subjects .
we did not find significant disorders in their nutrition and health state .
educational activities for a healthy nutrition are necessary . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: dural arteriovenous fistulae ( davf ) are common intracranial vascular lesions typically becoming symptomatic with cortical venous hypertension and possible hemorrhage . here , we present a case illustration of a petrous apex davf with marked medullary venous hypertension and a unique clinical presentation .
a 72-year - old female , whose clinical progression was significant for altered mental status and progressive weakness , presented with diplopia , right leg paresis , and ataxia .
the patient was found to have a petrous apex davf , cognard type iv . following treatment with onyx embolization ,
her symptoms rapidly improved , with complete resolution of diplopia and drastic improvement of her ataxia .
the importance of this case is in the presentation and deterioration of the clinical exam , resembling an acute ischemic event .
further , this case illustrates that davf may cause venous hypertension with rapid onset of focal neurologic symptoms not exclusive to cortical locations .
intracranial dural arteriovenous fistulae ( davf ) are vascular lesions that account for 1015% of intracranial vascular malformations .
they are characterized by multiple arteriovenous fistulae connections within the leaflets of the dura mater .
the natural history of these lesions is dependent upon both the anatomical location and the venous drainage patterns .
three classification systems have employed these variables in delineating low - risk from high - risk lesions .
low - risk lesions are more likely to follow a benign course , while high - risk lesions may result in hemorrhage , rebleeding , and higher mortality rates . the variety of characteristics of davf results in a spectrum of clinical presentations , from clinically asymptomatic to profound neurologic deficits on presentation .
the following is a case of a petrous apex davf , cognard classification type iv , presenting with rapidly evolving symptoms and marked medullary venous hypertension .
a 72-year - old female with a past medical history significant for hyperlipidemia , hypertension , diabetes mellitus type ii , and breast cancer status post left mastectomy was admitted to an outside facility after presenting to her local emergency department with a 4-day history of right leg paresis , ataxia , and vertical binocular diplopia . the patient reported first noticing the diplopia with distance gaze , and subsequently developing right - sided paresis and balance difficulties , with a propensity to fall to the right .
her symptoms persisted and she presented to a local emergency department with worsening right - sided weakness and ataxia . on examination ,
she was noted to have slurred , slow speech , vertical binocular diplopia , right lower extremity paresis , and difficulty maintaining her posture . computed tomography ( ct ) revealed subtle medullary edema and abnormal enhancement at the left petrous apex .
cerebral angiogram confirmed a davf at the left petrous apex with arterial supply from the anterior temporal branch of the left middle meningeal artery .
the venous drainage ran inferior along the ventral margin of the cervicomedullary junction ( fig .
she was transferred to our institution 9 days after admission for further management . on examination
her motor exam demonstrated marked weakness in the right lower extremity , more prominent proximally as well as mild weakness in the right upper extremity .
she was also noted to have hyperactive reflexes on her right lower extremity with an ipsilateral babinski sign .
she subsequently underwent onyx embolization of the left petrous apex davf with complete angiographic obliteration ( fig .
2 ) . on postembolization day 1 she noted improvement of the right - sided weakness and diplopia .
the diplopia had resolved by the following day and her motor exam had improved to the point that she could ambulate with the assistance of a walker .
she was discharged on postembolization day 6 to an acute rehabilitation facility with a scheduled follow - up angiogram in 6 months .
the anatomy of davf can be described as one or more arterial pedicles that can be traced to a single arteriovenous fistula site .
these pedicles coalesce to a distinct lesion located in the dura this is in contrast to a pial arteriovenous fistula or shunt , which involves the brain parenchyma .
though also called dural arteriovenous malformations , this nomenclature is not accurate , as a malformation denotes a congenital lesion . the majority of , if not all , davf are acquired lesions .
the pathogenesis of the fistulae is thought to be a multistep phenomenon instigated by thrombosis and resultant obstruction of a dural sinus .
the inciting thrombosis may be secondary to a hypercoagulable state induced by infection , trauma , or an iatrogenic stimulus such as surgical manipulation , for example , in the case of a resection of a lesion involving the sinus .
hypoxia triggers the production of angiogenic factors which in turn stimulate the formation of aberrant vessels with abnormal direct arteriovenous shunts [ 5 , 6 ] . alternatively , it has been suggested that impaired venous drainage leads to increased dural sinus pressure which in turn causes compensatory dilatation of physiologic shunts connecting the thrombosed sinus and the extracranial arterial system [ 5 , 7 ] .
the sustained increased pressure can translate to increased pressures in cortical veins leading to ischemic injury secondary to impaired outflow and/or hemorrhage both pathophysiologic mechanisms resulting in the onset of neurologic deficits [ 5 , 7 ] .
multiple classification systems have been employed to describe davf ; they all feature categorical divisions based on drainage patterns , as this characteristic of the lesions is the most prognostic with respect to risk of hemorrhage and corresponding neurologic deficits .
the first classification system , established by djindjian and merland in 1978 , was based on the initial drainage of the fistulae ; borden et al . and cognard introduced 2 angiographic - based classification systems that also incorporated the venous drainage .
's system is based on the site of cortical venous drainage as well as whether there are single or multiple fistulae present in the nidus . the cognard system is more directly an adaptation of djindjian and merland 's classification utilizing venous drainage , but also incorporating dural sinus flow directionality ( retro- or anterograde ) , and venous flow architecture into the classification system .
these classification systems were also applied in risk stratification with respect to the propensity for hemorrhage in davf .
classification schemas were derived to correlate the anatomy , drainage , and flow patterns with clinical presentation , indicated treatment , and prognosis .
a low - risk lesion , type iia , with retrograde flow into the sinus only , has potential risk for intracranial hypertension ; however , if asymptomatic , intervention is not indicated and serial clinical follow - up is recommended .
's series of 68 patients noted the benign natural history of those davf without cortical venous drainage .
only 1 out of 68 patients suffered a hemorrhage over a mean follow - up of approximately 28 months , and angiographic progression marked by the development of cortical venous drainage occurred in only 2 out of 50 patients with follow - up cerebral angiography .
conversely , in high - risk lesions such as types iii and iv the risk of hemorrhage is quoted at 40 and 65% , respectively .
's review of 20 cases of davf with cortical venous drainage revealed a 35% rate of rebleeding in those patients who presented with intracerebral hemorrhage .
type v lesions , with drainage into the spinal premedullary veins , lead to myelopathy in 50% of cases .
these higher - risk lesions , type iib and higher , merit closer consideration for surgical intervention . evolution from a low - risk to a high - risk lesion may occur in 24% of cases .
clinical presentation of davf ranges from an incidental finding in an asymptomatic patient to severe neurologic deficits secondary to hemorrhage , ischemia , or venous congestion .
the spectrum of presentations depends on many pathophysiologic factors including the degree of av shunting and increased venous pressure , and the presence of ischemia and recruitment of parenchymal venous drainage all of which are related to the anatomical features that govern the flow and drainage patterns of the fistula .
the natural history largely depends on the venous drainage ; thus the utility of the classification systems set forth by djindjian and merland , modified by cognard , and expanded upon by borden et al . ,
conservative treatment is indicated in asymptomatic patients with no evidence of retrograde cortical venous drainage .
intervention - based treatments include stereotactic radiosurgery ; transcatheter embolization , which may be transvenous or transarterial ; and open surgery .
with advancement in endovascular techniques , embolization ( either through a transvenous or a transarterial approach ) has become the mainstay of therapy .
benign fistulae without retrograde cortical venous drainage ( such as many transverse - sigmoid sinus davf or indirect cavernous sinus fistulae ) or for aggressive fistulae refractory to other treatments .
the case presented here exemplifies some of the diagnostic and therapeutic challenges as well as the clinical and radiological diversity of intracranial davf .
the patient described suffered from a potentially dangerous davf with exclusive retrograde parenchymal venous drainage causing severe and progressive neurological compromise .
several pathophysiologic factors led to the patient 's clinical presentation and subsequent deterioration . increased arteriovenous shunting and venous pressures from the petrous apex davf caused venous hypertension and congestion in the medulla , explaining the clinical manifestations and progression .
prompt and complete endovascular exclusion of the fistula resulted in dramatic improvement of her symptoms .
the rapid evolution of symptoms is similar to presentations observed in cases of acute ischemic events that result from thrombosis or hemorrhage .
similar to other acute ischemic insults , there are a variety of davf and a corresponding continuum of presentations and indicated interventions . | ### Summary:
: backgrounddural arteriovenous fistulae ( davf ) are common intracranial vascular lesions typically becoming symptomatic with cortical venous hypertension and possible hemorrhage . here , we present a case illustration of a petrous apex davf with marked medullary venous hypertension and a unique clinical presentation.methodscase report.resultsa 72-year - old female , whose clinical progression was significant for altered mental status and progressive weakness , presented with diplopia , right leg paresis , and ataxia .
magnetic resonance imaging revealed edema involving the medulla . on digital subtraction cerebral angiogram ,
the patient was found to have a petrous apex davf , cognard type iv . following treatment with onyx embolization ,
her symptoms rapidly improved , with complete resolution of diplopia and drastic improvement of her ataxia.conclusionthe importance of this case is in the presentation and deterioration of the clinical exam , resembling an acute ischemic event .
further , this case illustrates that davf may cause venous hypertension with rapid onset of focal neurologic symptoms not exclusive to cortical locations . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: because of the population growth and consequently a dramatic increase in the demand for energies , the constraints of fossil and nonrenewable resources , energy crisis , prices fluctuation , and destructive effects originating from burning of energy resources and due to an increase in environmental pollution that severely threatens human life , on the one hand , the clean , nonpolluting , and great potential of renewable energy opened up an expansive vista in the utilization of the solar , wind , water , and wave energy . the global potential for production of energy from wind has been investigated . in general investigation ,
the theoretical and exploitable potential estimated of wind energy in the world were about 10 ej ( each ej is equivalent to 10 j or is equivalent to 1.634 10 barrels of petroleum ) and 110 ej ( equivalent to 1.7974 10 barrels of petroleum ) , respectively . like other developing countries ,
iran has been encountered with significant challenges in energy and environmental policies . economic growth in iran
the energy production and also consumption have increased in iran in recent years due to its rapid economic growth .
the necessity of renewable energy in iran can be categorized in three main issues : ( a ) environmental pollution , ( b ) limited fossil resources , and ( c ) more oil and gas export .
the most important environmental problem that iran faces is air pollution and one of the main sources ofair pollutionis burningfossil fuels .
another issue that motivates the use of renewable energy in iran is the price of fuel for producing electric energy , and exportation , since 80% of iran 's revenue is based on oil and gas exportation [ 3 , 4 ] . therefore the government is paying to subsidize electric energy production .
the harmful effects of fossil fuels , such as air pollution , changes in rainfall , and climate , the high price of fossil fuels , and limited fossil resources force the researcher to think about the need for renewable energy seriously .
hence , wind energy appears as a clean and good solution to cope with a great part of this energy demand .
the horizontal movement of air parallel to the earth 's surface is a measure of the wind in both direction and magnitude .
wind energy is directly related to wind speed and other meteorological factors . for production of electricity by wind turbines , convenient area selection for greater efficiency
the sources of wind speed and energy change with time and other factors must be taken into account carefully and correctly .
iran with the unique climate and geographical position in the middle asia between warm and temperate weather areas of asia , europe , africa , the indian ocean , and the atlantic ocean has a considerable wind blowing potential and is potentially one of the best regions for utilization of most alternative sources of renewable energies .
lack of compressive study of wind energy potential in kurdistan for its exploitation is clear [ 3 , 7 , 8 ] . to provide clear image of the wind energy potential in our selected area ( kurdistan - qorveh ) ,
the scientific investigations and using the experiences of precursor countries in wind industry are needed . in this research ,
the wind resource potentials with electricity production ability in qorveh ( for installation of wind turbines ) by applied methods and geographical information are discussed .
the weather station data for speed and direction of wind were obtained from iran meteorological organization ( since its establishment up to 2005 ) and kurdistan meteorological site ( after 2005 ) .
the monthly and annual average and maximum speed for qorveh station in period of 20002010 were analyzed .
the statistical processing of wind speed and wind direction in synoptic station of kurdistan was carried out .
the ranking of meteorological stations of the country in period of 10 years ( 19932002 ) was gathered for calibration of wind map to have a reliable picture of wind regime .
wind rose model and diagram providing the dominant wind in an area , which can be determined , were used to the recognition of wind speed and direction status in different times in a certain place .
suitable turbine from gamesa ( g58 - 850 ) and suzlon ( s64 - 650 ) companies was selected .
the logarithmic law ( log - law ) was used for theoretical calculation of wind speed at different heights .
feasibility study includes wind blowing status , site evaluation , and selection , model selection of wind turbine .
some of the important factors of wind blowing for a site include : wind speed , wind speed distribution , wind direction distribution , daily pattern of wind speed , and yearly pattern of wind speed .
the log - law ( see ( 1 ) ) is a relationship between the wind speeds at one height and those at another ( reference height ) .
regional status of the studied area is important in aspect of surface roughness and atmospheric stability
. consider
( 1 ) ln(h / z0)ln(href / z0 ) = vvref ,
where v ( m / s ) is the wind speed at height h ( m ) , vref ( m / s ) is the known wind speed at a reference height href ( m ) and z0 ( m ) is the surface roughness length , which is determined according to table 1 , considering the types of land surfaces .
the power law is defined as [ 11 , 12 ]
( 2)(hhref)=vvref ,
where v ( m / s ) is the speed at height h ( m ) , vref ( m / s ) is the known wind speed in reference height href ( m ) , and the exponent ( ) is an empirically derived coefficient that varies dependent upon the direction shift or surface roughness which can be determined by ( 3 )
( 3)=0.096(log10z0)+0.016(log10z0)2 + 0.24 ,
where z0 is the surface roughness lengths ( table 1 ) .
wind speed increases with increasing the height above the ground , the pressure and temperature decrease with increasing height , and so the ability of turbine can be affected ( see ( 4 ) and ( 5 ) ) .
therefore , the height should not be so high to lead to sensible changes in turbine efficiency .
gross energy production is the total annual energy produced by the wind energy equipment , before any losses , at the wind speed , atmospheric pressure , and temperature conditions at the site .
gross energy production eg is calculated through
( 4)eg = euchct ,
where eu is the unadjusted energy production , and ch and ct are the pressure and temperature adjustment coefficients .
ch and ct are given by
( 5)ch = pp0,ct = tt0 .
in these relations , p and t
p0 and h0 are standard pressure ( 101.3 kpa ) and standard temperature ( 288 k ) , respectively . considering the perpetual changes of wind vector , its analysis based on numeral value as monthly average can not be exact . for analysis and determination of wind speed , wind direction , and wind speed distribution over a certain period of time ,
the density function can model the wind speed distribution by using mathematical functions ( pearson , two parameteric weibull distribution log
the two parameteric weibull distribution is the most popular function for description of wind speed data . since in divandareh station
the seasonal average wind speed in spring and summer is greater than in other seasons so we studied their histograms ( spring and summer ) in different heights .
but in qorveh station , the winter and spring seasons have higher average wind speed compared with others .
therefore , these seasons were considered for studying in 30 and 60 m heights in qorveh station .
the weibull probability density function is defined as
( 6)f(v)=kc(vc)k1e(v / c)k ( k > 0 , v > 0,c>1 ) ,
where f(v ) is the velocity ( v ) probability , c ( m / s ) is the scale parameter , and k ( dimensionless ) is weibull shape parameter . the high k value causes the sharpness and the low k value causes the broadening weibull peak . to draw the weibull probability density function curve ,
one of the determination methods of these two factors is maximum likelihood method . in this method ,
first by helping of a recursive relationship ( see ( 7 ) ) , the k value is calculated . then by using ( 8)
consider
( 7)k=[j=1nvjkln(vj)j=1nvjkj=1nln(vj)n]1,(8)c=(1nj=1nvjk)1/k ,
where vj is the speed of jth sample , n is the sum of samples , and ( 8) is a recursive relationship which needs a primary k value that is usually assumed to be equal to 2 .
but the true primary k value can be obtained by ( 9 ) , [ 11 , 16 ] .
consider
( 9)k=(v)1.086 , 1k10 ,
where v- is mean and is standard deviation of the samples .
consider
( 10)v=1nj=1wmjvj,=1n1j=1n(viv)2 ,
where n is the total number of observations during measurement , mj is the total number of observations for vj velocity , and w is the number of different velocities .
the weibull cumulative distribution function is defined as
( 11)f(v)= 1e(v / c)k .
when in the weibull probability density function k = 2 , the rayleigh probability density function can be obtained .
it is one of the most applicable functions in this field and can be defined as
( 12)f(v)= 2vc2ev2/c2 .
the relation between parameter c and data average ( ) is defined as
( 13)=c2 .
with an expression of the gamma function (x )
, the average wind speed can be expressed as a function of c and k , at 10 , 30 , and 60 m as follows :
( 14)(x)=0yx1ey dy ,
where y = ( v / c ) and v / c = y ; x = 1 + 1/k .
the average speed v- can be calculated by
( 15)v=f(k , c)=c(1 + 1k ) .
from ( 14 ) and by helping of power law and gamma function , the speed average can be calculated and compared with pdf way value .
the most likely wind blowing and wind speed at special location indicate the usual wind and the usual wind speed distribution in this location .
it can be determined by the help of weibull shape , scale parameters , and following equation
( 16 ) vmp = c ( 11k)1/k ( m / s ) . it is known that the wind and air stream produce and transport energy .
the maximum of this energy can be determined by ( 17 ) and weibull parameters .
consider
( 17)vme = c ( 1 + 2k)1/k ( m / s ) . one of the important factors to select a place for installation of turbine is wind power density of this place . without considering the turbine type , one can calculate the annual power of an area by equation [ 11 , 18 ] as follows :
( 18)wpd= pa=j=1nvj3 1n .
also the wind power density can be determined by weibull function parameters and the relation :
( 19)pa=012v3f(v )
it is clear that for wind energy production , the place of turbine installation should have high average wind speed and continuous wind blowing .
so the speed and other wind parameters studies are considered as initial and important stages of potential evaluation of one region for installation of wind house power . the time interval value to determine the periodical change of wind status is important .
the meteorologists believe that 30-year period is needed for long time determination of weather condition and atmospheric changes , and for achieving yearly average wind speed at least 5-year period is needed .
kurdistan province is located in the west of iran and the latitude and the longitude of kurdistan are 3533n and 4708e , respectively .
there is a 2400 m difference between the lowest altitude ( a lot in baneh 900 m ) and the highest point ( shahoo with 3300 m ) .
the number of glacial days in a year is 109 and the annual rainfall in normal condition is about 500 mm .
the dominant winds of this region are western stream from the atlantic ocean and the mediterranean sea in winter and northwest stream in summer .
also , the new energy organization of iran ( sana ) has established three weather stations in divandareh ( 2006 ) , qorveh ( 2008 ) , and zarineh ( 2011 ) .
the curves of monthly average speed and the maximum speed for qorveh station in period of 20002010 were analyzed and the results of this investigation are shown in table 2 , which shows the variation range of monthly average and maximum speed in each station in period of 20002010 , 10 m in height .
figure 1 compares the annual average value in kurdistan meteorological stations from 2000 to 2010 , 10 m in height .
table 3 shows the monthly average of wind speed in period of 20002010 at kurdistan meteorological center , 10 m in height .
the wind speed is increased in spring and winter in all stations . the monthly and annual average wind speed in sites of saqqez , sanandaj , marivan , and kamyaran are lower than the other stations [ 19 , 20 ] .
table 4 shows the ranking of meteorological stations of the country in period of 10 years ( 19932002 ) and it is gathered for calibration of wind map to have a reliable picture of wind regime ; as can be seen the zarineh is placed in sixth and bijar is placed in thirteenth of this ranking at country level .
figure 2 shows the wind rose at qorveh station in 19982007 in march , april , and may .
table 5 shows the percentage frequency and wind distribution in different speed ranges in march , april , and may in qorveh.based on average and maximum wind speed obtained from kurdistan meteorological stations in the years 20002010 , the baneh , zarineh , bijar , and qorveh centers are in the acceptable range of wind speed potential for wind energy production.based on monthly average values of wind speed in period of 20002010 , the baneh , zarineh , and bijar sites have higher ranking levels .
the maximum wind speed was obtained in spring and winter ( feb , march , april , and may ) . according to the annual diagram of wind speed of all stations in period of 20002010 ( not shown ) ,
the wind speed variation shows descent trend in all of sites except qorveh.also in ranking of weather station of iran , based on average wind speed 10 m in height , during ten years ( from 1993 until 2002 which was performed by irimo ) , the zarineh with average wind speed of 5.8 m / s is at sixth and the bijar with average wind speed of 5.2 m / s is at thirteenth stage of this ranking .
these results confirm that zarineh and bijar sites have acceptable wind speed potential.according to the monthly wind rose diagram , the directions of predominant winds of zarineh were west and southwest , of the bijar was south , and of qorveh were west and southwest ( figure 3 ) . based on average and maximum wind speed obtained from kurdistan meteorological stations in the years 20002010 , the baneh , zarineh , bijar , and qorveh centers are in the acceptable range of wind speed potential for wind energy production .
based on monthly average values of wind speed in period of 20002010 , the baneh , zarineh , and bijar sites have higher ranking levels .
the maximum wind speed was obtained in spring and winter ( feb , march , april , and may ) . according to the annual diagram of wind speed of all stations in period of 20002010 ( not shown )
also in ranking of weather station of iran , based on average wind speed 10 m in height , during ten years ( from 1993 until 2002 which was performed by irimo ) , the zarineh with average wind speed of 5.8 m / s is at sixth and the bijar with average wind speed of 5.2 m / s is at thirteenth stage of this ranking .
according to the monthly wind rose diagram , the directions of predominant winds of zarineh were west and southwest , of the bijar was south , and of qorveh were west and southwest ( figure 3 ) . the wind speed changes with the change of height above the ground , as the wind speed increases linearly with increasing height above the ground .
the wind speed at altitude 450 m is about 4 - 5 times of its speed on the ground . to obtain more power and efficiency from wind turbines and to access a suitable wind speed , the turbines are installed at high height .
the wind speed and direction data at height 10 m from the ground were recorded , where the altitude of turbines installation was higher than that .
one of the practical methods for wind parameters measurement at high altitude is using weather masts ( installation of several sensors in heights 30 , 40 , 60 , and 80 m ) .
in addition to the mentioned method , there are two important equations to the theoretical calculation of the wind speed in other heights related to a reference wind speed ( e.g. 10 m ) .
since the wind data of synoptic centers has been recorded at height 10 m. to calculate the wind speed at other heights by theoretical method , some valid regional and local indexes and parameters are needed .
therefore , we use 10-minute data of qorveh and divandareh sites in 2007 and 2009 , which were recorded by sana anemometer ( the wind speeds were recorded at heights 10 , 30 , and 40 m and the wind directions were recorded at height 30 and 37.5 m ) [ 1 , 3 ] . for determination of wind speed by ( 2 ) at height ( h ) and reference height ( href )
the surface roughness coefficient ( z0 ) can be extracted from table 1 , and can be calculated according to ( 3 ) .
we determined z0a = 0.25 mm for divandareh site ( a ) and z0b = 0.15 mm for qorveh site ( b ) .
the corresponding coefficients can be determined as [ 1823 ] the following:(1)if z0a = 0.25 mm a=0.188(2)if z0b = 0.15 mm b=0.15 if z0a = 0.25 mm a=0.188 if z0b = 0.15 mm b=0.15
( ii ) the second method for coefficient determination .
the coefficient is calculated by ( 2 ) and by the comparison of wind speed ( recorded by weather station for each month ) in heights 30 and 10 m. the mean value for 12 months is considered as coefficient and the mean values for divandareh and qorveh are
( 20)a=0.2 , b=0.144 .
since the coefficient obtained by the second method
is determined by sensors and anemometer , the results are close to real values , therefore for wind speeds calculation at other heights the value was considered as b = 0.144 and a = 0.2 .
the wind speed at heights 10 and 30 m is determined from excel data and at 60 m determined according to ( 2 ) and coefficient . also , the maximum wind speed in 30 m height was determined .
because of facile installation of domestic 660 and 300 kw turbines at 60 m height , this height was selected for work .
the range of wind speed in height 60 m at the qorveh station was 4.47.80 m / s and at the divandareh station was 4.47.7 m / s .
the highest values of wind speed were obtained in february , march , and april at these stations . also , the maximum wind speed in height 30 m was variable from 17.0 to 26.7 m / s in the qorveh station and this range for divandareh station was from 14.2 to 22.7 .
figure 3 shows the frequency distribution diagrams of wind speed obtained in spring and winter in heights 30 and 60 m in qorveh station .
the frequency for wind speed of 5.5 m / s in spring season in 30 m height is about 1320 , but for winter , this number is about 1200 that is lower than that of spring season .
the velocity probability f(v ) , the scale parameter c ( m / s ) , and the weibull shape parameter k ( dimensionless ) which are obtained with matlab , are shown in table 6 .
the power density of qorveh , a site in two heights of 30 and 60 m , has been calculated , results of which are shown in table 7 .
the basis of this calculation was ten - minute data . to select a suitable turbine for a certain place ,
one of the most important factors is the wind speed at this place . as regards , the monthly average wind speed in qorveh station in 60 m height and technical study of the various turbines from different companies ( such as ge , suzlon , norder , vestas , and gamesa ) , because of high capacity , facile installation , and ability to produce power according to site condition ( compatibility with region ) the turbines from gamesa ( g58 - 850 ) and suzlon ( s64 - 650 ) companies were selected .
in summary , in this work , by statistical analyses of wind direction and speed in years of 20002010 in 10 m height , the qorveh , baneh , bijar , and zarineh stations were recognized as the areas of good wind energy potential . in these areas ,
investigation shows that there has been a slight declining trendat wind speed in all of these sites during the recent eleven years . in part two of this work , a model for calculation of wind speed in different heights based on wind speed at reference height and surface roughness length
based on mathematical model of weibull density function , the monthly , seasonal , and annual wind speed distribution probabilities were determined .
the results of simulation model with matlab are shown as curves , tables , and parameters .
the weibull probability density function curve and the histograms of qorveh site based on 10-minute period data were drawn at different heights .
wind power densities of qorveh and divandareh sites in two heights of 30 and 60 meters were calculated and their wind class was indicated as 25 , but their annual wind class was 3 . based on the wind power density data , the qorveh site was distinguished as a suitable place for turbine installation . also by the studying of sana wind atlas , the divandare ( zarineh ) , bijar , and the regions between qorveh and dehgolan , with average wind velocity of 7 to 9 m / s , were determined as places with high wind potential .
the results of the technical studies of various turbines from different companies show the g58 - 850 and su turbine models are suitable for installation in our sites . | ### Summary:
: in the current work by using statistical methods and available software , the wind energy assessment of prone regions for installation of wind turbines in , qorveh , has been investigated .
information was obtained from weather stations of baneh , bijar , zarina , saqez , sanandaj , qorveh , and marivan . the monthly average and maximum of wind speed
were investigated between the years 20002010 and the related curves were drawn . the golobad curve ( direction and percentage of dominant wind and calm wind as monthly rate ) between the years 19972000 was analyzed and drawn with plot software . the ten - minute speed ( at 10 , 30 , and 60 m height ) and direction ( at 37.5 and 10 m height )
wind data were collected from weather stations of iranian new energy organization .
the wind speed distribution during one year was evaluated by using weibull probability density function ( two - parametrical ) , and the weibull curve histograms were drawn by matlab software . according to the average wind speed of stations and technical specifications of the types of turbines , the suitable wind turbine for the station
was selected .
finally , the divandareh and qorveh sites with favorable potential were considered for installation of wind turbines and construction of wind farms . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: for drug delivery by
solid oral dosage forms , the formulation contains
an active pharmaceutical ingredient ( api ) either in one of its crystalline
or in an amorphous form .
although given its lower energy state and
better long - term stability properties , where typically the crystalline
form is preferred , amorphous api formulations are of intense interest
due to their higher intrinsic solubility .
formulation of amorphous drugs may , however , lead to an undesired
crystallization during the shelf life of the dosage form .
it is therefore crucial to understand and control the mechanisms
involved in the crystallization from the amorphous phase .
paracetamol
is a common analgesic drug , widely used as a painkiller
and for its antipyretic effects .
these can be arranged from the most stable at standard
temperature and pressure as form i > form ii > form iii .
it is also relatively straightforward to supercool
the melt and prepare an amorphous form , which is the least stable
of all its solid forms . despite its well - characterized
solid forms , paracetamol exhibits a peculiar crystallization behavior
that is strongly affected by minor experimental conditions .
a recent study by nanubolu et al . has offered a comprehensive comparison
between various experimental conditions and crystallization patterns .
it has been found that , while the uncovered samples
are predominated by surface crystallization into forms i and ii , the
covered samples are dominated by bulk crystallization into form iii .
the characterization of amorphous materials is complicated by the
lack of well - defined structure and the strong dependence on the thermal
history which is common to all amorphous materials .
structural solid - state
characterization techniques such as x - ray diffraction ( xrd ) can not
easily differentiate between amorphous solids that differ energetically .
the thermal history has a strong effect on the thermodynamic properties
of the glasses , which in turn are easier to quantify : thermo - analytical
techniques such as ( modulated ) differential scanning calorimetry ( dsc )
and thermally stimulated depolarization current measurements offer a straightforward way to determine the glass transition temperature ,
the onset of the molecular mobility and crystallization . in order
to create a more comprehensive microscopical image
one commonly used technique that is used for such characterization
is dielectric spectroscopy , which can cover an extremely broad range
of frequencies from 10 hz up to 10 hz , and possibly up to 10 hz when quasi - optical techniques
are involved .
the dielectric spectra in this frequency range reveal
primary and secondary relaxation processes in the supercooled liquids
and glasses .
several studies suggested that the ( primary ) relaxation
time may be used for an estimation of the amorphous pharmaceutical
stability during storage .
later studies however
emphasized the importance for including the localized motions of the
johari
goldstein secondary relaxation in the predictions and the caveat that these estimations
are not universally valid .
in addition ,
inelastic incoherent neutron scattering studies revealed that the
fast secondary relaxations occurring at nanosecond time scales play
a crucial role in the protein stabilization in glasses . a relatively novel technique for the characterization of solid - state
pharmaceuticals is terahertz time - domain spectroscopy ( thz - tds , typically
covering frequencies between 0.1 and 4 thz ) .
the strength of terahertz spectroscopy lies in its ability to probe
the intermolecular excitations in materials that are too fast to measure
with dielectric spectroscopy yet at too low energies for far - infrared
spectroscopy .
thz - tds has several additional practical advantages ,
such as being a nondestructive , nonionizing , contact - free , phase - sensitive
technique , and experiments are performed using average power levels
on the order of microwatts with no danger of inducing any structural
modification due to the experimental radiation .
organic molecular crystals usually exhibit distinct spectral
fingerprints at terahertz frequencies that can be exploited to identify
polymorphic forms , hydrates , or cocrystals , often with sensitivities
exceeding that of other vibrational spectroscopy techniques due to
the fact that vibrational modes at terahertz frequencies originate
from the intermolecular interactions within the crystal structure
rather than from intramolecular modes , which dominate the spectra
at higher frequencies .
terahertz spectroscopy is emerging also
as a useful complementary
characterization tool in the field of disordered materials .
it was shown that all terahertz spectra of disordered materials
are featureless due to a universal coupling mechanism of terahertz
radiation into the vibrational density of states ( vdos ) .
terahertz spectroscopy was used to study atomic
charge distributions of sodosilicate glasses , optical properties in a very broad frequency range of 0.218
thz of chalcogenide glasses , and the
glass transition in polymers .
a recent study of aqueous
sorbitol solutions showed that the absorption originating from the
vdos becomes gradually dominated by the dielectric relaxation processes
as the molecular glasses are heated above their respective glass transition
temperature .
given the fundamental difference
between the spectra of disordered and ordered systems , terahertz spectroscopy
is ideally suited to monitor the crystallization of amorphous drugs or polymers and
distinguish between different solid - state modifications . in
the present study , we aim to extend the current state of understanding
using terahertz spectroscopy of the amorphous phase and its crystallization .
with the example of paracetamol
, we show the wealth of information
that can be extracted from the terahertz spectra of a supercooled
liquid and liquid melt , which might at first sight be erroneously
mistaken to be rather boring due to their featureless nature .
we show
that the mechanism and level of absorption at terahertz frequencies
is different in such phases and that this behavior can be extracted
from the spectra using a simple power law model .
lastly , we show how
this information can be used to determine the onset of crystallization
in supercooled liquids .
paracetamol
( acetaminophen , 99% purity ) was
obtained from sigma - aldrich , uk . polyethylene powder
( particle size
< 10 m ) was obtained from induchem , volketwil , switzerland .
for the room temperature
thz - tds measurements , 60 mg of crystalline paracetamol was mixed with
300 mg of polyethylene powder , loaded , and compressed into a pellet
using a hydraulic pellet press at a force of 2 tons . for the reference ,
a pellet made of 300 mg of polyethylene powder was used .
a sample of crystalline
paracetamol was heated to 460 k ( 187 c ) on a hot plate
until fully melted . in order to eliminate degradation ,
it was ensured
that the melt remains as a clear liquid and does not turn yellow to
any visible extent .
the sample holder was a sandwich structure consisting
of two circular crystalline z - cut quartz windows ( 1.5 mm thickness ,
13 mm diameter ) separated by a spacer made from mylar with a nominal
thickness of 190 m .
the spacer had an aperture of 9 mm in diameter
in its center that was fully filled with the melt of paracetamol .
the sandwich structure was then placed into a metal holder that was
screwed to a copper block with an aperture of 9 mm , sealing the melt
between the two windows ( figure 1 ) . at this
point ,
the sample was removed from the hot plate and cooled to room
temperature ( 295 k ) by placing the copper block on a large metal table .
the quartz windows are pressed together
by a copper cradle , with ptfe rings between the quartz and copper
to allow for differential thermal expansion .
the sample is held in
the mylar spacer between the windows , with a slit cut in it .
following
amorphous sample
preparation , the copper block was attached to the coldfinger of a
cryostat ( modified continuous flow st-100 ftir , janis , wilmington ,
ma , usa ) and mounted in the vacuum chamber of a thz - tds setup . for
the reference measurements
, we used two 1.5 mm thick quartz windows
with no spacer between that were mounted just below the sample onto
the same copper coldfinger of the cryostat .
the sample was heated
from 295 to 470 k in 5 k steps under vacuum . upon reaching each temperature
increment ,
after
this time , the reference measurement was acquired in transmission
geometry as described elsewhere , followed
by the sample measurement .
each measurement took 4 min by co - averaging
200 time - domain waveforms .
overall , the sample was equilibrated for
approximately 10 min prior to the acquisition of the respective terahertz
spectrum .
the optical properties of the sample were extracted in the
frequency range of 0.13.0 thz using fast fourier transformation
of the time - domain waveforms . for the detailed study of the
crystallization kinetics of paracetamol
from its amorphous form , a sample was prepared in the same way as
described in the sample preparation section above .
the sample was
then heated from room temperature to 320 k in 5 k steps , and spectra
were acquired in order to confirm that no crystallization had yet
taken place over this temperature range
. the sample was then heated
continuously from 320 to 340 k with a heating rate of 0.4 k min .
terahertz spectra of the sample were acquired at
a scan rate of 1 hz throughout this period . in order to increase the
signal - to - noise ratio of the resulting spectra
, 120 time - domain waveforms
were averaged for each data point , resulting in an effective temperature
resolution of 0.8 k. it was
previously shown that
the absorption of glasses at terahertz frequencies can be well - described
by a combination of and power laws that may be ascribed to uncorrelated ( due to long - range
disorder ) and correlated ( due to local charge neutrality ) charge fluctuations ,
respectively .
the uncorrelated part of
the absorption usually dominates , and
therefore , one power law with an exponent close to 2 is usually a
good fit of the data , as shown originally by strom .
we recently demonstrated that the terahertz spectra
obey the power law not only in the glassy state but also in supercooled
liquid as well as liquid phases , as the spectra remain without sharp
spectral features .
overall , the absorption
coefficient multiplied by the refractive index , that is , the real
part of the conductivity , in the nonionic liquids may be described
by1where is frequency and c describes the strength
of the coupling of terahertz radiation to
the amorphous matter . as outlined above ,
the exponent q is close to 2 in the glassy state where losses are dominated by
the vdos and decreases toward 1 as the sample is heated above the
glass transition temperature , tg , where
losses become dominated by the dielectric relaxation .
the parameters a and 0 were introduced to account for
the fact that the experimental terahertz spectra are acquired only
from some positive frequency 0 ( here 0.1 thz ) , and
the absorption at this frequency may be nonzero . thus a represents absorption at 0 and is strongly related
to the tail of the dielectric relaxation processes occurring at lower
frequencies .
the first scan was used to determine the actual polymorph
of the crystalline paracetamol measured by thz - tds at room temperature .
five milligrams of crystalline sample was loaded into an aluminum
pan and crimped ( closed with a lid ) .
the calorimetric measurement
was performed with a ta instruments q2000 calorimeter from room temperature
to 470 k at 10 k min .
the second scan was
used to accurately determine the onset of crystallization in amorphous
paracetamol .
for this purpose , 5 mg of crystalline sample was loaded
into an aluminum pan and crimped .
the sample was then heated to 453
k , melted , quenched down to 298 k , heated to 320 k , equilibrated for
15 min , and measured from 323 to 373 k at a rate of 0.4 k min , which matches the heating rate of the variable temperature
thz - tds experiment described above .
dsc
measurements revealed a melting endotherm at 442 k ( 169 c ) ,
indicative of paracetamol form i , the most stable polymorph at room
temperature .
the thermal analysis revealed
no other thermal events , indicating that only form i was present .
the terahertz spectra of the paracetamol pellet obtained at room
temperature are shown in figure 2 .
absorption spectrum extracted from the
sample pellet composed of
crystalline paracetamol form i at 295 k. the absorption terahertz
spectra over the full temperature range of 295470 k are shown
in figure 3 .
the absorption coefficient at
several chosen frequencies is shown as a function of temperature in
figure 4 .
the lowest temperature at which we
acquired spectra , 295 k , is very close to the glass transition temperature
of paracetamol , tg = 296 k. at the lowest
temperatures , the sample is therefore considered to be in the supercooled
liquid state .
the absorption of the supercooled liquid increases monotonously
with frequency and temperature , and no spectral features can be observed .
at about 335 5 k ,
crystallization occurs from the supercooled
liquid , which results in a dramatic change in the terahertz spectra ,
and two peaks , one at 0.7 thz and the other at around 2.5 thz , emerge .
as the sample is heated further , the spectral features change at around
375 5 k and again at 405 5 k , signaling two solid
the sample finally melts at around
455 5 k. the spectral features disappear again , and once again ,
the spectra are dominated by a monotonous increase in absorption with
frequency , similar in shape and magnitude to what was previously observed
for the spectra of the supercooled liquid .
absorption spectra of
paracetamol at terahertz frequencies upon
heating the sample from the supercooled liquid phase over the temperature
range of 295470 k in 5 k increments .
absorption coefficient of paracetamol at ( a ) 0.7 thz , ( b ) 1.0 thz ,
( c ) 1.5 thz , and ( d ) 2.5 thz in the temperature range of 295470
k with 5 k increments .
the vertical dotted lines separate different
states of paracetamol : a = amorphous , iii , ii , i = crystalline polymorphs ,
and l = liquid .
the absorption terahertz
spectra obtained during the detailed investigation of the onset of
crystallization using the continuous heating method in the temperature
range of 320340 k are shown in figure 5 . at temperatures below 330
k ( light gray ) , the sample stayed amorphous ,
slightly increasing in absorption with temperature .
as the sample
was heated above 330 k , the spectra with narrow spectral features
around 0.7 , 1.4 , and 2.5 thz began to emerge from the monotonous background ,
which is a clear signature of crystallization of paracetamol . during
the last 2 k of heating ,
the sample of the spectra ceased to change ,
indicating a completion of the crystallization process .
absorption
spectra of paracetamol at terahertz frequencies upon
heating the sample continuously from 320 to 340 k ( light gray to dark
lines in 0.8 k intervals ) at a heating rate of 0.4 k min .
in figure 6a , we compare the terahertz spectra
of all the different crystalline polymorphs that were observed by
heating the sample of amorphous paracetamol in this study .
the spectral
features of an organic molecular crystal at terahertz frequencies
typically originate from intermolecular vibrations and librations ,
given the relatively low energy of the modes , though some additional
intramolecular flexibility can also be observed , in particular , for
larger molecules .
( a ) absorption spectra of different crystalline forms
of paracetamol ;
( b ) thermal shift of spectral lines of form i between 295 ( pellet ) ,
415 , and 455 k ( crystallized amorphous form ) .
it is important to keep in mind that the spectra in figure 6 were acquired in situ over a range of temperatures
and that the intermolecular modes will shift in frequency due to the
change in temperature . here ,
all modes show a red shift upon heating ,
which is in good agreement with previous studies .
the extent of the red shift , and associated change in spectral intensity ,
is highlighted in figure 6b for form i , where
the peak that is observed at around 2.8 thz at room temperature shifts
by 0.05 thz to lower frequencies upon heating from 415 to
455 k ( i.e. , by 40 k ) .
based on this observation and by using linear
extrapolation , it may be thus concluded that at room temperature ,
295 k , this mode would sit at around 2.95 thz , which is in good agreement
with the peak observed in the terahertz spectra of the pellet of paracetamol
form i ( figure 2 ) .
the assignment of the spectra
between 415 and 455 k to form i is further supported by the complete
lack of any feature at around 0.7 thz , which is present in both of
the other polymorphs . we conclude that at temperatures just below
the melting point paracetamol has crystallized into form i. this is
in agreement with the fact that , thermodynamically , form i is the
most stable known polymorph
. a recent comprehensive raman microscopy
study of paracetamol showed
that different crystallization behavior from the amorphous phase is
strongly dependent on the environmental conditions , that is , whether
the sample is covered or uncovered , during crystallization . in the case of a covered sample , which is also
the case in this study
since the sample is sealed between two quartz
windows and the measurement takes place under vacuum , amorphous paracetamol
crystallized , in this order , first to form iii ( 323329 k ) ,
followed by two phase transitions to forms ii ( 385391 k ) and
i ( 421 k ) upon heating .
we observe a crystallization
from the amorphous phase at 330 k followed by two phase transitions
at 370 and 405 k ( figure 4 ) , and given the
proximity in temperature to the crystallization events reported by
nanubolu and burley ( considering the differences in heat transfer
and sample size between the raman and terahertz setups ) , we conclude
that we observe forms iii , ii , and i as well as melting of form i
at around 455 5 k upon heating the sample of amorphous paracetamol .
aside
from identification of crystalline forms , we recently showed that
thz - tds can be used also to differentiate between distinct regimes
of supercooled liquids .
well below tg , the terahertz spectra of amorphous solids
are well - described by a coupling of the terahertz radiation into the
vibrational ( and/or librational ) density of states , vdos , as outlined
above . as the amorphous sample is heated toward and above tg
, dielectric relaxations happen at shorter
time scales and shift up in frequency into the terahertz frequency
range .
this leads to an increase in absorption mainly at the lower
end of the spectra that can be measured by thz - tds .
this effect is
best illustrated in figure 7 by plotting the
imaginary part of the dielectric losses , = cn/(2 ) , as this representation is the
common practice used in the dielectric spectroscopy literature .
dielectric
losses of supercooled liquid paracetamol between 295
and 325 k ( blue solid lines ) and liquid melt paracetamol between 460
and 470 k ( red dashed lines ) . at low temperatures ,
the spectrum is dominated by the low - frequency
part of the vdos peak centered about 23 thz ( only the low - frequency
wing of this peak is accessible using thz - tds ) . from figure 7 , it is apparent that the dielectric relaxation
processes cause an increase of the losses in the spectrum below 1
thz .
this is expected given that the
lowest experimental temperature in this experiment is above tg .
the exact center frequency of the vdos peak
can not be determined accurately due to the limited spectral window .
it is interesting to note that at frequencies above 1.5 thz the losses
measured in the liquid of the melt are lower than the losses of the
supercooled liquid .
one would expect the magnitude of the losses in
the melt to be close to that of supercooled liquid and glasses , that
is , at the level of the vdos . at present , the origin of this difference
remains somewhat unclear .
commonly , a decrease in the intensity and
a red shift of the excess vdos over the debye level is observed upon
heating a glass ; this however is influenced by a faster increase of
the debye level over the overall vdos of amorphous material rather
than a decrease in overall vdos . in similar
terahertz spectroscopy studies , where a glass was heated to high temperatures ,
no decrease of losses was observed upon heating at any frequency in
the range of 0.13 thz . in this previous work ,
the samples were however usually quenched deeply below tg and they never recrystallized upon heating .
therefore ,
it remains to be explored in the future whether the thermal history
can affect the level of vdos in a supercooled liquid close to tg and whether crystallization of a sample can
cause a systematic offset in the measurement of the melt .
using
the power law approach ( eq 1 ) , the
terahertz spectra of amorphous , supercooled liquid , and liquid phases
can be analyzed in more detail .
, the
lower cutoff frequency for the fit was fixed to 0 = 0.1 thz , which is the low - frequency limit of our spectrometer .
fit by eq 1 of real part of conductivity
( n ) of supercooled liquid ( 300 and 330 k ) ,
crystalline solid ( 335 k ) , and melt ( 470 k ) of paracetamol .
it is
obvious that the fit is not suitable to describe the spectral features
of the crystalline phase .
the fitting parameters a , c ,
and q are plotted against temperatures in figure 9 .
it is expected
to be close to zero in the glassy state and to increase above tg as a result of contributions from the dielectric
relaxations that shift into the spectral range at higher temperatures .
parameter c represents the
strength of the coupling of terahertz radiation into the sample . in
the glassy state , this describes coupling to the vdos .
parameter q may be used to differentiate between
the glassy and liquid states . in the glassy state ,
q is expected to be close to 2 . on the other hand ,
in the liquid phase ,
q is close to 1 as a result
of the absorption being dominated by dielectric relaxations .
generally
speaking , with the increasing contribution of the dielectric relaxations , c will increase and q will decrease , which
corresponds to the straightening of the terahertz
spectra that is observed .
parameters a , c and q as extracted from the fit of n to the experimental
spectra using eq 1 . the fit was performed on
two independently acquired data sets that were obtained by either
increasing the temperature step - by - step ( black squares ) or continuously
using a constant ramp rate ( red triangles ) .
no values are shown for
the temperature range 345455 k as the sample was crystalline
at these temperatures and eq 1 does not apply
for crystalline materials .
the value of a obtained
from continuous measurement has been offset by 20 cm . from the spectra plotted in
figure 8
it is obvious that the model expressed
by eq 1 is not suitable to describe spectra
of crystalline samples . in a polycrystalline sample , where the shape
of the baseline is strongly linked to scattering of terahertz radiation , it is far from linear and usually well described
by a quadratic dependence on frequency .
therefore , the spectra become less straight at the
onset of crystallization .
this deviation from the model can be exploited
in order to accurately determine the onset of crystallization , not
from a structural perspective as would be resolved by techniques such
as x - ray diffraction , but from a molecular dynamics point of view . in order to do this ,
we have analyzed the spectra obtained from
the continuous measurement at constant temperature ramp between 320
and 345 k ( figure 5 ) using the power law eq 1 .
all three obtained fitting parameters
follow the crystallization process above 330 k. there are a number
of interesting observations to highlight in this context . as the sample
crystallizes , the coupling of terahertz radiation into the vdos , c , decreases .
this is due to the fact that crystalline materials
are dominated by vibrational modes that are associated with long - range
order and hence the vdos breaks down into these discrete modes . as
a result , the baseline drops between the frequencies
of the vibrational modes , even though it does never fully reduce to
absolute zero absorption due to scattering and other losses .
on the
other hand , the exponent of the power law , q , increases
with crystallinity of the sample .
both effects are the result of the
spectral shape changing from an almost straight line upon heating - induced
crystallization to exhibiting a stronger curvature .
the parameters c and q suggest that the crystallization
is complete at around 340 k. in contrast , parameter a shows a rather extraordinary decrease above 335 k. this observation
highlights that , although the power law is able to fit the spectra
obtained from the amorphous phase well , it may suffer from an unequal
bias on different fitting parameters in the case of crystalline materials .
we therefore conclude that the change in a above
335 k is not related to the crystallization but presents an artifact
from the fitting process of the now crystalline spectra using an equation
derived for the amorphous phase . from figure 8 , it is apparent that the obtained
values of c and q generally agree
between the step - by - step and continuous temperature experiments .
the
value of a obtained from the continuous experiment
had to be offset by 20 cm in order to match the
value from the step - by - step measurement .
the origin of this discrepancy
is linked to a difference in the spectra at the lowest terahertz frequencies .
the exact reason for this is unclear for the time being , but we believe
that it is most likely linked to the subtle differences in thermal
history between the two samples .
the crystallization kinetics
can be described by various models , one of the
commonly used being the avrami
erofeev crystallization
kinetics , which is defined by the equation2where rc is the
crystalline ratio of the sample , k is the rate constant , t is time , and n the exponent reflecting
the mechanism of crystallization .
for example , for n = 3 , the model is known also as the random nucleation and
growth mechanism .
the crystalline
ratio rc can be also
expressed as rc = 1 ra , where ra is the corresponding
amorphous ratio . in order to reflect the fact that the crystallization
of the amorphous sample does not start immediately with the beginning
of the heating experiment , given that we start acquiring at temperatures
well below the onset of crystallization , eq 2 can be modified to3 here
, t0 is for the onset time of the
crystallization relative to the beginning of the continuous temperature
ramp . in order to determine the accurate onset of the crystallization
,
the fit was performed only on the data with an apparent presence of
crystalline phase , that is , for temperatures above 330 k. this is
crucial as one of the prerequisites of the avrami
erofeev model
is the existence of a nucleus from which the growth of the crystalline
phase occurs . the avrami
erofeev crystallization kinetics
model can be
used to fit the values of c and q between 330 and 340 k ; however , before eq 2 can be used , the values must be normalized .
the normalized values cnorm and qnorm were
obtained by subtracting the baseline value at the highest temperatures
for c and the lowest temperatures for q and rescaling the data to 1 .
given that c decreases
and q increases upon crystallization , cnorm was assigned to ra and qnorm with rc in
order to perform the avrami erofeev fitting using eqs 3 .
the rescaled parameters cnorm and qnorm are shown in figure 10a , together with the fit by the avrami
the value of n was chosen to reflect the fact that crystallization from a covered
sample of paracetamol is dominated by bulk crystallization .
erofeev ( ae ) fit of ( a ) normalized values
of c and q obtained from power law
fit eq 1 and ( b ) amorphous and crystalline ratio
obtained
from fit of spectra by eq 4 a different way to express ra and rc is by assuming that the absorption
spectra
(t, ) of the sample at any given temperature
between purely amorphous and purely crystalline form are described
by4where t is temperature ,
is frequency , and a and c are
the absorption spectra of the purely amorphous and purely crystalline
form . using this method , the data obtained from the continuous temperature
spectroscopy were analyzed ( figure 5 ) , where
amorphous spectra a corresponded to the spectra
at 320 k and the crystalline spectra c corresponded
to the absorption level at 422 k , that is , at the spectra at lowest
and the highest temperature , respectively .
the obtained amorphous
( ra(t ) ) and crystalline
( rc(t ) ) ratios are shown
in figure 10b . similarly to the case of cnorm and qnorm ,
the values of ra and rc have been fitted using the avrami
erofeev model
eqs 3 with n = 3 reflecting
the bulk crystallization of paracetamol .
the obtained values for the crystallization rate k and onset of crystallization t0 are
summarized in table 1 .
the values are similar ,
although cnorm and qnorm result in slightly higher crystallization rate k and later onset of crystallization t0 than the values obtained from the fit of rc and ra .
the values of cnorm and qnorm are
however more vulnerable toward errors given the fact that the power
law is not a very good fit for the terahertz spectra of semicrystalline
samples and it needed to be normalized .
the dsc value determined
using the tangents method ( figure 11 ) is slightly
higher than the values obtained using the avrami erofeev fits .
the fitted values are much closer to the onset of deviation of the
heat flow from its baseline tangent , which seems intuitive as our
terahertz method detects subtle changes in the intermolecular arrangement .
the last two lines represent
the onset of crystallisation obtained from dsc as shown in figure 11 .
dsc of the
crystallization of amorphous paracetamol at a heating
rate of 0.4 k min ( endotherms pointing down ) .
the red solid lines represent the tangents used to determine the onset
of crystallization at 332 k. the vertical line at 328 k highlights
the onset temperature where the heat flow deviates from the baseline
tangent .
the idea of splitting the spectra
into crystalline and amorphous
fractions using eq 4 has also its limitations .
the sum ra + rc is expected to be unity at all temperatures and times . in order
to meet this criterion , only spectra up to 1.2 thz were used , and
overall , it can be stated that 1 < ra + rc < 1.06 .
when a broader spectral
range is used , the sum will be generally higher , but narrowing the
range further had no effect on the sum .
one of the reasons for the
sum exceeding unity is likely to originate from additional scattering
from some crystalline or amorphous parts of the sample as the grain
structure of the sample changes during crystallization .
another reason
is the slight increase in absorption level of the amorphous part of
the sample with increasing temperature given the non - isothermal conditions .
although , overall , the model works well in our case , it may be even
more suitable for an isothermal study of a crystallization process .
the crystallization and subsequent melting has
been studied for
a sample of amorphous paracetamol at terahertz frequencies . upon heating
amorphous paracetamol , crystallization into form iii
is observed ,
followed by phase transitions to forms ii and i at higher temperatures .
this observation is in agreement with a previous study of paracetamol
by low - frequency raman scattering , where
the authors observed the same sequence of polymorphic forms appearing
under similar sample conditions ( sample covered and here additionally
under vacuum ) .
the featureless spectra that are observed at terahertz
frequencies for the supercooled liquid and liquid melt can both be
fitted using a modified power law model .
the main difference between
the terahertz absorption of the liquid melt and the supercooled liquid
is that the melt spectrum is dominated by the dielectric relaxation
as well as the vdos , while in the supercooled liquid the contribution
due to the dielectric relaxation vanishes close to tg , which is reflected by a change of the power law exponent
from 2 in the glassy state to 1 in the liquid melt state .
we demonstrate
that the spectral deviation from the power law model can be used as
a very sensitive probe for the onset of crystallization .
in addition ,
we have revealed evidence that the crystallization has a stronger
effect on the vibrational characteristics of the materials when compared
to the dielectric relaxation properties . using the terahertz spectra
together with a power law fit
, we were able to demonstrate a method
of extracting quantitative kinetic information from the spectra based
on the avrami
we determined an effective
rate constant of k = 0.056 min with a corresponding onset of crystallization at t = 329.5 k for a heating rate of 0.4 k min .
the
method described in this work is applicable to investigate crystallization
event of any hydrogen - bonded organic molecular crystals . | ### Summary:
: for the case of paracetamol , we show
how terahertz time - domain
spectroscopy can be used to characterize the solid and liquid phase
dynamics .
heating of supercooled amorphous paracetamol from 295 k
in a covered sample under vacuum leads to its crystallization at 330
k. first , form iii is formed followed by the transformation of form
iii to form ii at 375 k , to form i at 405 k , and finally melting is
observed around 455 k. we discuss the difference between the featureless
spectra of the supercooled liquid and its liquid melt .
lastly , we
studied the onset of crystallization from the supercooled liquid in
detail and quantified its kinetics based on the avrami erofeev
model .
we determined an effective rate constant of k = 0.056 min1 with a corresponding onset of crystallization
at t = 329.5 k for a heating rate of 0.4 k min1 . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: aeromonas is a kind of oxidase - producing gram - negative rods and belongs to the family aeromonadaceae .
it is widely distributed globally in aquatic environments and associated with a variety of human infections , including gastroenteritis , soft tissue infection , septicemia , hepatobiliary tract infections , and occasionally pleuropulmonary infections , indwelling - device related infections , meningitis , peritonitis , and hemolytic uremic syndrome ( 1 ) . although this pathogen could infect healthy persons , most infections were found in immunocompromised hosts , especially those with liver cirrhosis and malignancies ( 1 - 4 ) .
the possible portals of entry for aeromonas bacteremia were considered as gastrointestinal tracts and skin lesions ( 1 - 5 ) .
after the adhesion to the epithelial cells of the intestine , this pathogen produces many potential virulence factors to destroy epithelial barrier and impair immune cells , including exoenzymes , cytotoxic and cytotonic enterotoxins ( 6 , 7 ) . among 21 aeromonas species differentiated on the basis of dna - dna hybridization , aeromonas caviae , aeromonas veronii biovar sobria and aeromonas hydrophila
are most associated with human infections and amount for > 85% of all clinical isolates ( 2 - 5 ) .
they have different biochemical properties ( 8 , 9 ) and antimicrobial susceptibilities ( 10 , 11 ) .
, we conducted a retrospective study to compare clinical presentations of the bacteremias caused by different aeromonas species .
this is a retrospective study , in which the patients diagnosed with monomicrobial aeromonas bacteremia were admitted at buddhist tzu chi general hospital , buddhist dalin tzu chi general hospital and buddhist taipei tzu chi general hospital ( taiwan ) from january 2001 to november 2008 .
buddhist tzu chi general hospital is a 700-bed tertiary referral medical center locating in eastern taiwan with special units for bone marrow and organ transplantation , burn care and intensive care .
buddhist dalin tzu chi general hospital and buddhist taipei tzu chi general hospital are 900-bed regional teaching hospitals locating in southern taiwan and northern taiwan .
the demographic , clinical and laboratory information were retrieved from the medical charts of the included patients for analysis .
aeromonas bacteremia was defined as growth of an aeromonas sp . from a blood culture of a patient with sepsis .
bacteremia was considered healthcare - associated if an aeromonas isolate was obtained from blood sampled after more than 72 hr of hospitalization in a patient who had been asymptomatic for infection upon admission , or from a patient who had received antineoplastic chemotherapy in the preceding 2 weeks after drawing blood for culture , regardless of symptomatology at admission .
aeromonas - involved polymicrobial bacteremia defined as simultaneous growth of an aeromonas sp . and other microbe(s ) from a blood culture of a patient with sepsis were excluded from this study .
death was considered to be attributable to aeromonas bacteremia if , during the same hospital stay , death occurred within 7 days after a positive blood culture for aeromonas bacteremia without other cause for death , death occurred in the presence of clinical evidence of persistent sepsis , or the cause of death as recorded on the death certificate was aeromonas bacteremia .
survivor from aeromonas bacteremia was defined as if the patient was discharged alive or an improvement of bacteremia - associated symptoms occurred in the absence of recurrence within 30 days during the same hospital stay . according to the sepsis - related organ failure score criteria ,
the diagnosis of respiratory failure is based on the ratio of arterial oxygen tension ( pao2 ) to fractional inspired oxygen ( fio2 ) < 200 mmhg .
( apache ii ) score within 72 hr after the occurrence of symptoms associated with aeromonas bacteremia .
acid - suppressant therapy was defined as use of proton pump inhibitors or histamine h2 blockers for more than 7 days within 4 weeks before onset of the symptoms associated with aeromonas bacteremia .
blood samples were tested daily for microbial growth by the bactec 9240 ( bd , diagnostic instrument systems , spark , md , usa ) .
gram - negative bacilli from blood culture bottles were identified as aeromonas species by positive oxidase reaction , no growth on thiosulfate - citrate - bile - sucrose agar , growth on macconkey agar , and resistance to the vibriostatic compound o/129 .
biochemical profiles with the vitek ii system ( biomrieux , lyon , france ) , bd - phoenix system ( bd diagnostic instrument systems ) or api-20ne system ( biomrieux ) were utilized for identification of aeromonas species .
additional tests for api-20ne system included hydrolysis of esculin and gas production from glucose fermentation .
additional tests for vitek ii system or bd - phoenix system included hydrolysis of esculin , voges - proskauer reaction , acid production from sucrose fermentation , ornithine decarboxylase , acid from arabinose fermentation , and arginine dihydrolase production . in vitro antimicrobial susceptibilities of aeromonas isolates were tested using the kirby - bauer disk - diffusion method , or automated methods ( vitek ii system or the bd - phoenix system ) .
antibiotics selected for testing included ampicillin , amikacin , cefazolin , gentamicin , cefmetazole , ceftriaxone , cefuroxime , ciprofloxacin , imipenem , flomoxef , cefpirome , ceftazidime , sulfamethoxazole / trimethoprim , aztreonam , ticarcillin / clavulanic acid , and piperacillin / tazobactam .
the breakpoint concentrations for interpretation were in accordance with clinical and laboratory standards institute ( 13 ) .
spss v. 11.5 for ms windows software ( spss , chicago , il , usa ) software was used for statistical analyses .
pearson 's chi - square test was used to examine nominal data , and one - way anova was used for continuous data .
all tests were two - sided and a p value of 0.05 was considered significant .
this study was approved by the institutional review board of buddhist dalin tzu chi general hospital ( irb no .
blood samples were tested daily for microbial growth by the bactec 9240 ( bd , diagnostic instrument systems , spark , md , usa ) .
gram - negative bacilli from blood culture bottles were identified as aeromonas species by positive oxidase reaction , no growth on thiosulfate - citrate - bile - sucrose agar , growth on macconkey agar , and resistance to the vibriostatic compound o/129 .
biochemical profiles with the vitek ii system ( biomrieux , lyon , france ) , bd - phoenix system ( bd diagnostic instrument systems ) or api-20ne system ( biomrieux ) were utilized for identification of aeromonas species .
additional tests for api-20ne system included hydrolysis of esculin and gas production from glucose fermentation .
additional tests for vitek ii system or bd - phoenix system included hydrolysis of esculin , voges - proskauer reaction , acid production from sucrose fermentation , ornithine decarboxylase , acid from arabinose fermentation , and arginine dihydrolase production . in vitro antimicrobial susceptibilities of aeromonas isolates were tested using the kirby - bauer disk - diffusion method , or automated methods ( vitek ii system or the bd - phoenix system ) .
antibiotics selected for testing included ampicillin , amikacin , cefazolin , gentamicin , cefmetazole , ceftriaxone , cefuroxime , ciprofloxacin , imipenem , flomoxef , cefpirome , ceftazidime , sulfamethoxazole / trimethoprim , aztreonam , ticarcillin / clavulanic acid , and piperacillin / tazobactam .
the breakpoint concentrations for interpretation were in accordance with clinical and laboratory standards institute ( 13 ) .
spss v. 11.5 for ms windows software ( spss , chicago , il , usa ) software was used for statistical analyses .
pearson 's chi - square test was used to examine nominal data , and one - way anova was used for continuous data .
all tests were two - sided and a p value of 0.05 was considered significant .
this study was approved by the institutional review board of buddhist dalin tzu chi general hospital ( irb no .
the mean age was 58 yr ( range , 24 to 92 yr ) and the overall duration of hospitalization was 15 days ( range , 1 - 82 ) .
there were 112 ( 73% ) male patients and 43 ( 28% ) patients with healthcare - associated bacteremias .
liver cirrhosis was most common underlying disease ( 58% ) , followed by diabetes mellitus ( 28% ) and solid cancer ( 26% ) .
there were 126 ( 82% ) patients with fever , 107 ( 69% ) patients with thrombocytopenia , and only 40 ( 26% ) patients with leukocytosis .
of the 87 ( 56% ) patients with a. hydrophila bacteremia , one presented with acute cholangitis , one with spontaneous bacterial peritonitis , two with traumatic wound infections , two with urosepsis , four with necrotizing fasciitis , and the others with primary bacteremia . of the 45 ( 29% ) patients with a. veronii biovar sobria bacteremia , one presented with urosepsis , one with spontaneous bacterial peritonitis , one with necrotizing fasciitis , one with meningitis and the others with primary bacteremia . of the 22 ( 14% ) patients with a. caviae bacteremia , one patient presented with acute cholecystitis , one with traumatic wound infection , one with lung abscess and the others with primary bacteremia .
three patients with a. hydrophila bacteremia and one patient with a. caviae bacteremia survived more than 30 days after onset of aeromonas bacteremia .
one died due to hepatoma rupture , another due to esophageal veins bleeding , and the others due to septic shock caused by other pathogens .
table 1 summarizes clinical presentations of the monomicrobial bacteremias caused by a. hydrophila , a. veroni biovar sobria , and a. caviae .
a. caviae was more associated with healthcare - associated bacteremia than a. hydrophlia and a. veronii biovar sobria .
however , a. veronii biovar sobria and a. hydrophila were more associated with the cirrhotic patients than a. caviae .
thrombocytopenia and shock were more common in a. veronii biovar sobria bacteremia and a. hydrophila bacteremia than a. caviae bacteremia .
the apache ii scores and mortality of a. hydrophila and a. veronii biovar sobria bacteremia were higher than a. caviae bacteremia .
of the 87 a. hydrophila isolates , 61 were identified mainly by api-20ne system , 17 by vitek ii system , and 9 by bd - phoenix system . of the 45 a. veronii biovar
sobria isolates , 34 were identified mainly by api-20ne system , 5 by vitek ii system , and 6 by bd - phoenix system .
of the 22 a. caviae isolates , 16 were identified mainly by api-20ne system , 3 by vitek ii system , and 3 by bd - phoenix system . in vitro antimicrobial susceptibilities of different aeromonas species
more a. veronii biovar sobria isolates were susceptible to cefazolin and flomoxef than the other aeromonas species .
less a. caviae isolates were susceptible to sulfamethoxazole / trimethoprim than the other aeromonas species .
univariate analyses for risk factors of bacteremia - associated mortalities were listed in table 3 . in a.
hydrophila bacteremia , thrombocytopenia , diarrhea , apache ii score > 20 points , and adequate empirical antibiotics were risk factors for bacteremia - associated mortality .
the four factors were included for multivariate logistic regression analysis . only apache ii score was the independent factor for survival ( odds ratio : 22.501 ; p < 0.001 ) . in a.
veronii biovar sobria bacteremia , apache ii score was significant risk factor for bacteremia - associated mortality .
she had liver cirrhosis , diabetes mellitus , and chronic usage of acid - suppressant therapy .
she presented with fever , dyspnea , septic shock , and thrombocytopenia with 31 points of apache ii score at admission .
she was treated with levofloxacin , which was considered as an adequate empirical antibiotics according in vitro antimicrobial susceptibility .
1 showed box plots of the distributions of apache ii scores for monomicrobial aeromonas bacteremia stratified by different aeromonas species and survival .
commercial phenotyping systems used routinely in clinical microbiology laboratories are not exactly correct for identification of aeromonads ( 14 , 15 ) .
lamy and his coworkers compared 6 commercial systems for identifying clinical aeromonas isolates ( 16 ) .
the accuracy of api-20ne system was good for a. hydrophila and a. veronii but not for a. caviae .
the accuracy of vitek ii system for a. hydrophila and a. caviae was good but not for a. veronii .
the accuracy of bd - phoenix system for a. caviae and a. veronii was good but not for a. hydrophila .
additional tests , like esculin hydrolysis , gas production from glucose , voges - proskauer reaction , ornithine decarboxylase , and arginine dihydrolase production are necessary for confirmation of aeromonas species identified by the commercial systems .
however , their accuracy of identification is still not compatible with the molecular method . in the present study ,
large sample size alleviated this bias and complementary effect of these three commercial systems can decrease the extreme deviation caused by single commercial system .
the case mortality among patients with aeromonas bacteremia in the literature ranges from 24%-63% ( 2 - 5 , 17 - 22 ) .
clinical presentations among different aeromonas species were rarely discussed due to limited cases . in a study including 104 episodes , aeromonas species was divided into hydrophila and non - hydrophila and the resulting fatalities were 35.5% ( 22/62 ) and 23.8% ( 10/42 ) respectively ( 2 ) . in another report including 59 episodes , the mortalities caused by a. hydrophila , a. veronii biovar sobria , and a. caviae are 33% ( 13/40 ) , 56% ( 5/9 ) , and 17% ( 1/6 ) respectively ( 22 ) . however , this tendency could not be noted in another report , in which aeromonas - associated polymicrobial bacteremia was not excluded ( 4 ) .
the present study only included monomicrobial aeromonas bacteremia and proved that the mortality of a. caviae bacteremia was lower than a. hydrophila bacteremia or a. veronii biovar sobria bacteremia .
majority of a. hydrophila and a. veronii biovar sobria isolates were capable of persistent colonization but a. caviae isolates was not . in vitro study showed that a. caviae isolates , unlike other aeromonas isolates were less toxic to hep-2 cell .
however , most of aeromonas isolates used for these studies were from the natural environment and the virulence factors of aeromonas species from infected hosts and natural environments were different ( 24 ) .
only a study showed the virulence factors from the bacteremia - associated aeromonas isolates ( 12 ) .
the genes for cytotoxic enterotoxin were more common in the a. veronii biovar sobria ( 13/13 ) and a. hydrophila ( 15/20 ) isolates than the a. caviae isolates ( 3/14 ) .
cytotoxic enterotoxin could activate mitogen - activated protein kinases and induce classical caspase - associated apoptosis in murine macrophages ( 25 ) .
therefore , poor abilities of a. caviae to produce cytotoxic enterotoxin may be the reason for better prognosis of a. caviae bacteremia .
the patients diagnosed with healthcare - associated aeromonas bacteremia had been considered to have colonization of aeromonas species in their gastrointestinal tracts before admission ( 2 ) . in the previous study ,
liver cirrhosis was associated with community - acquired aeromonas bacteremia and malignancy with healthcare - associated aeromonas bacteremia ( 2 - 4 ) . in the present study
, we found that a. caviae was more associated with healthcare - associated infection and less associated with cirrhosis than the other species .
this phenomenon may be also due to poor abilities of a. caviae to produce cytotoxic enterotoxin .
cirrhotic patients have impaired intestinal permeability due to intestinal congestion , edema , and local hypoxia due to portal hypertension , which creates a good environment for bacterial translocation ( 26 - 29 ) . however , additional factors for destroying mucosal barrier are necessary to help bacterial translocation .
cytotoxic enterotoxin produced by aeromonas species can induce apoptosis of human intestinal epithelial cells and may play an important role for bacterial translocation ( 25 ) .
due to poor production of enterotoxin , a. caviae has lower chance to cause bacterial translocation in cirrhotic patients than the other aeromonas species .
compared with the cirrhotic patients , the cancer patients had more chances to receive surgeries or cytotoxic agents during hospitalization , which caused extensive intestinal mucosal damage .
that may be the reason why a. caviae was more associated with healthcare - associated bacteremia . in our study , the susceptibility of these microorganisms to trimethoprim - sulfamethoxazole , and cefazolin showed inter - species variability .
besides , we observed that flomoxef was active to only about 50% isolates of a. caviae and a. hydrophila .
although flomoxef belongs to oxyimino--lactam and is considered as a kind of extended - spectrum cephalosporin , traditional extended - spectrum cephalosporins are more efficacious for treatment of aeromonas bacteremia .
although there were some limitations from different commercial identifying systems in our study , this study included large sample size and showed different clinical presentations of bacteremia among a. hydrophila , a. veronii biovar sobria and a. caviae . in conclusion ,
the severity of a. caviae bacteremia is lower than a. hydrophila bacteremia or a. veronii biovar sobria bacteremia .
different clinical characteristics among aeromonas hydrophila , aeromonas veronii biovar sobria and aeromonas caviae monomicrobial bacteremia han - chuan chuang , yu - huai ho , chorng - jang lay , lih - shinn wang , yeong - shu tsai and chen - chi tsai this study aimed to evaluate the clinical presentations of 154 patients having a. hydrophila , a. veronii biovar sobria or a. caviae monomicrobial bacteremia by retrospective methods in taiwan .
the clinical presentation of a. caviae bacteremia was much different from a. hydrophila and a. veronii biovar sobria bacteremia .
the patients with a. caviae bacteremia had less severity and lower mortality than those with a. veronii biovar sobria or a. hydrophila bacteremia . | ### Summary:
: this study aimed to compare the clinical presentations of aeromonas hydrophila , a. veronii biovar sobria and a. caviae monomicrobial bacteremia by a retrospective method at three hospitals in taiwan during an 8-yr period .
there were 87 patients with a. hydrophila bacteremia , 45 with a. veronii biovar sobria bacteremia and 22 with a. caviae bacteremia . compared with a. hydrophila and a. veronii biovar sobria bacteremia ,
a. caviae bacteremia was more healthcare - associated ( 45 vs 30 and 16% ; p = 0.031 ) .
the patients with a. caviae bacteremias were less likely to have liver cirrhosis ( 27 vs 62 and 64% ; p = 0.007 ) and severe complications such as shock ( 9 vs 40 and 47% ; p = 0.009 ) and thrombocytopenia ( 45 vs 67 and 87% ; p = 0.002 ) .
the apache ii score was the most important risk factor of aeromonas bacteremia - associated mortalities .
the apache ii scores of a. caviae bacteremias were lower than a. hydrophila bacteremia and a. veronii biovar sobria bacteremia ( 7 vs 14 and 16 points ; p = 0.002 ) . in conclusion ,
the clinical presentation of a. caviae bacteremia was much different from a. hydrophila and a. veronii biovar sobria bacteremia .
the severity and mortality of a. caviae bacteremia were lower than a. hydrophila or a. veronii biovar sobria bacteremia . |
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: an estimated 300,000 patients in united states hospitals are mechanically ventilated each year , placing them at risk for ventilator - associated pneumonia ( vap ) . up to 20% of mechanically ventilated patients may develop vap , resulting in prolonged hospital length of stay , increased healthcare costs , and risk of disability in those that survive hospitalization .
efforts to reduce the development of vap have primarily focused on sedation management , spontaneous breathing trials , stress ulcer and venous thromboembolism prophylaxis , head of bed elevation and oral hygiene .
chlorhexidine ( peridex ) is a topical antibiotic oral rinse with activity against both gram - positive and gram - negative organisms , which has shown efficacy in some , but not all , studies for vap prevention .
these studies have found significant reductions in nosocomial infection rates , incidence of pneumonia and significantly less gram - negative organisms from the use of chlorhexidine 0.12% solution .
although many studies favor chlorhexidine use , other similar studies have shown comparable rates of vap between the chlorhexidine and control groups . due to limitations with available literature and lack of consistency among efficacy outcomes , the 2005 infectious disease society of america ( idsa ) guidelines for
hospital - acquired , ventilator and healthcare - associated pneumonia does not recommend routine use of chlorhexidine until more data becomes available .
in contrast , the society of critical care medicine strongly supports the use of vap prevention bundles , which incorporates the use of topical oral chlorhexidine as an intervention championed by the institute for healthcare improvement .
the objective of this study was to assess the rate of probable vap in mechanically ventilated sicu patients before and after implementation of routine chlorhexidine mouthwash prophylaxis using the 2013 centers for disease control guideline definitions .
this retrospective cohort study assessed ventilator - associated events prior to and following the implementation of chlorhexidine mouthwash in the 44-bed surgical intensive care unit ( sicu ) in a university medical center .
institutional review board ( irb ) approval was obtained from the university office of responsible research practices institutional review board , and was carried out with the ethical standards set forth in the helsinki declaration on 1975 .
the primary outcome was the development of probable vap based on the 2013 center for disease control definition , with vap defined as pneumonia occurring > 48 hours following endotracheal intubation . according to the 2013 cdc ventilator - associated event ( vae ) guidelines ,
a ventilator - associated condition ( vac ) is the initial surveillance tier , which confirms the patient to be mechanically ventilated for at least 2 calendar days of stable or decreasing daily minimum positive end - expiratory pressure ( peep ) or fraction of inspired oxygen ( fio2 ) ; then followed by at least 2 days of increased daily minimum peep 3 cm h2o greater than the daily peep during the baseline period or where the increase in the daily minimum fio2 is 0.20 ( 20% points in oxygen concentration ) greater than the daily minimum fio2 during the baseline period
. the second tier , infection - related ventilator - associated complication ( ivac ) is defined as evidence of an abnormal white blood cell count ( 12,000 cell / mm or 4,000 cell / mm ) or abnormal temperature ( > 38c or < 36c ) and initiation of a new antibiotic that is continued for at least 4 days .
possible and probable vap are defined as the third tier of the vae surveillance guidelines , which attempts to identify the subset of ivac patients with respiratory infections that include evidence of purulent respiratory secretions and/or positive results of microbiological tests performed on respiratory tract specimens .
possible vap is the presence of purulent secretions or a positive lower respiratory tract culture .
probable vap is defined as increased oxygenation demand as described in ivac above with confirmation of purulent secretions and > 10,000 cfu / ml from bronchoalveolar lavage ( bal ) . in the sicu ,
diagnosis of pneumonia in mechanically ventilated patients is standardized with protected - catheter quantitative bal cultures based on clinical and radiographical symptoms . in 2007 ,
our institution developed and implemented a ventilator bundle that included oral care ( oral care mouth swabs every 4 hours and as needed , brushing every 12 hours and subglottic suctioning every eight hours ) , venous thromboembolism prophylaxis , stress ulcer prophylaxis , sedation management and spontaneous breathing trials .
routine use of chlorhexidine mouthwash ( 15 ml , twice daily ) was initiated in all mechanically ventilated patients with tracheostomies in the sicu in february 2010 as a method to reduce ventilator - associated pneumonia ( vap ) .
this study evaluated probable and possible vap in mechanically ventilated sicu patients with a positivebal prior to and following the addition of chlorhexidine mouthwash to the ventilator bundle .
all mechanically ventilated patients admitted to the sicu between january 1 , 2009-december 31 , 2009 and march 1 , 2010 february 28 , 2011 were screened for bal cultures .
the pre - group comprised patients before implementation of chlorhexidine mouthwash ( january 1 , 2009 december 31 , 2009 ) while the post - group included patients who received prophylactic chlorhexidine mouthwash every 12 hours as part of the vap prevention protocol ( march 1 , 2010 february 28 , 2011 ) .
patients were included for analysis if they were mechanically ventilated for 2 days , had a positive bacterial quantitative bal culture within 2 days of the onset of worsening oxygenation .
patients were excluded from analysis if they were less than 18 or greater than 89 years of age , pregnant , incarcerated or had care withdrawn during treatment .
data collected included demographics ( age , gender , weight , height ) , baseline vitals / clinical pulmonary infection score ( cpis ) , bal cultures and sensitivities , chest radiograph ( cxr ) results , ventilator status and requirements , sputum data , duration and type of antibiotic therapy , mechanical ventilator duration , length of icu and hospital stay , and mortality .
all patient data were obtained from our institutional information warehouse ( iw ) , electronic patient information system [ integrated healthcare information system ( ihis ) ] and essentris medical records .
the primary outcome of the study was rate of probable vap prior to and following chlorhexidine mouthwash implementation .
statistical analyses were performed using statistical package for social sciences ( spss ) version 20 ( ibm armonk , ny ) .
categorical variables were analyzed using chi - square statistics and fisher 's exact test and are presented as number and percentage .
continuous data with normal distribution was assessed using the student 's t - test and is presented as mean standard deviations , while non - parametric data was analyzed using mann - whitney u and is presented as median [ intra - quartile ranges ( iqr ) ] . prior to initiation of the study , statistical significance was set for a p value < 0.05 .
this retrospective cohort study assessed ventilator - associated events prior to and following the implementation of chlorhexidine mouthwash in the 44-bed surgical intensive care unit ( sicu ) in a university medical center .
institutional review board ( irb ) approval was obtained from the university office of responsible research practices institutional review board , and was carried out with the ethical standards set forth in the helsinki declaration on 1975 .
the primary outcome was the development of probable vap based on the 2013 center for disease control definition , with vap defined as pneumonia occurring > 48 hours following endotracheal intubation . according to the 2013 cdc ventilator - associated event ( vae ) guidelines ,
a ventilator - associated condition ( vac ) is the initial surveillance tier , which confirms the patient to be mechanically ventilated for at least 2 calendar days of stable or decreasing daily minimum positive end - expiratory pressure ( peep ) or fraction of inspired oxygen ( fio2 ) ; then followed by at least 2 days of increased daily minimum peep 3 cm h2o greater than the daily peep during the baseline period or where the increase in the daily minimum fio2 is 0.20 ( 20% points in oxygen concentration ) greater than the daily minimum fio2 during the baseline period . the second tier , infection - related ventilator - associated complication ( ivac ) is defined as evidence of an abnormal white blood cell count ( 12,000 cell / mm or 4,000 cell / mm ) or abnormal temperature ( > 38c or < 36c ) and initiation of a new antibiotic that is continued for at least 4 days .
possible and probable vap are defined as the third tier of the vae surveillance guidelines , which attempts to identify the subset of ivac patients with respiratory infections that include evidence of purulent respiratory secretions and/or positive results of microbiological tests performed on respiratory tract specimens .
possible vap is the presence of purulent secretions or a positive lower respiratory tract culture .
probable vap is defined as increased oxygenation demand as described in ivac above with confirmation of purulent secretions and > 10,000 cfu / ml from bronchoalveolar lavage ( bal ) . in the sicu ,
diagnosis of pneumonia in mechanically ventilated patients is standardized with protected - catheter quantitative bal cultures based on clinical and radiographical symptoms . in 2007 ,
our institution developed and implemented a ventilator bundle that included oral care ( oral care mouth swabs every 4 hours and as needed , brushing every 12 hours and subglottic suctioning every eight hours ) , venous thromboembolism prophylaxis , stress ulcer prophylaxis , sedation management and spontaneous breathing trials .
routine use of chlorhexidine mouthwash ( 15 ml , twice daily ) was initiated in all mechanically ventilated patients with tracheostomies in the sicu in february 2010 as a method to reduce ventilator - associated pneumonia ( vap ) .
this study evaluated probable and possible vap in mechanically ventilated sicu patients with a positivebal prior to and following the addition of chlorhexidine mouthwash to the ventilator bundle .
all mechanically ventilated patients admitted to the sicu between january 1 , 2009-december 31 , 2009 and march 1 , 2010 february 28 , 2011 were screened for bal cultures .
the pre - group comprised patients before implementation of chlorhexidine mouthwash ( january 1 , 2009 december 31 , 2009 ) while the post - group included patients who received prophylactic chlorhexidine mouthwash every 12 hours as part of the vap prevention protocol ( march 1 , 2010 february 28 , 2011 ) .
patients were included for analysis if they were mechanically ventilated for 2 days , had a positive bacterial quantitative bal culture within 2 days of the onset of worsening oxygenation .
patients were excluded from analysis if they were less than 18 or greater than 89 years of age , pregnant , incarcerated or had care withdrawn during treatment .
data collected included demographics ( age , gender , weight , height ) , baseline vitals / clinical pulmonary infection score ( cpis ) , bal cultures and sensitivities , chest radiograph ( cxr ) results , ventilator status and requirements , sputum data , duration and type of antibiotic therapy , mechanical ventilator duration , length of icu and hospital stay , and mortality .
all patient data were obtained from our institutional information warehouse ( iw ) , electronic patient information system [ integrated healthcare information system ( ihis ) ] and essentris medical records .
the primary outcome of the study was rate of probable vap prior to and following chlorhexidine mouthwash implementation .
statistical analyses were performed using statistical package for social sciences ( spss ) version 20 ( ibm armonk , ny ) .
categorical variables were analyzed using chi - square statistics and fisher 's exact test and are presented as number and percentage .
continuous data with normal distribution was assessed using the student 's t - test and is presented as mean standard deviations , while non - parametric data was analyzed using mann - whitney u and is presented as median [ intra - quartile ranges ( iqr ) ] .
prior to initiation of the study , statistical significance was set for a p value < 0.05 .
in the year prior to implementation of chlorhexidine mouthwash there were 2550 patients admitted to the sicu including 1780 patients that received mechanical ventilation for > 48 hours while 2647 admissions in the post - group included 1854 patients that received mechanical ventilation for > 48 hours .
a total of 601 patients that had bal cultures screened were evaluated for inclusion into this study .
a total of 158 patients met inclusion criteria for analysis , with 94 patients in the pre - group and 64 patients in the post - group .
out of the 601 patients screened , 386 patients ( 64.2% ) had no bacterial growth , 34 patients ( 5.6% ) had non - quantitative cultures , and 23 patients ( 3.8% ) were no longer in the sicu to complete the study .
the majority of patients were male with a median age of 57 ( 44.5 - 68.5 ) years .
baseline characteristics did not differ significantly between groups although there was a trend towards more trauma patients in the post - group [ table 1 ] .
the majority of patients were admitted to the sicu on hospital day 1 with a similar median time to bal collection of 8 days in the pre - group and 7 in the post - group .
baseline demographics overall 100 patients did not experience an increase in minimum peep 3 cm h2o or fio2 by 0.20 for at least 2 days ( 50 in pre - group and 40 in post group , p = 0.24 ) , and 13 patients ( 8 pre - group and 5 post - group , p = 0.42 ) did not have an abnormal wbc or temperature [ figure 1 ] . the rate of possible vap did not differ between groups ( 3 events in 1780 patients in the pre - group versus 4 in 1854 patients in the post - group , p > 0.99 , figure 2 ) .
there was a significant decrease in rate of probable vap from 1.85% in the pre - group ( 33 events in 1780 patients ) to 0.81% in the post - group ( 15 events in 1854 patients p = 0.0082 ) .
the median duration of mechanical ventilation was 15 days in both the pre - group [ 9 - 33 ] and the post - group [ 10 - 22 ] ( p = 0.4 ) .
median icu length of stay for the pre - group was 22 [ 13 - 35 ] days compared to 18 [ 13 - 25 ] days in the post - group ( p = 0.18 ) , and the median hospital length of stay was 28 [ 16 - 42 ] days and 23 [ 17 - 29 ] days ( p = 0.22 ) , respectively .
there was similar mortality between both groups ( 25.5% pre - group versus 15.6% in the post - group , p = 0.17 ) .
incidence of probable and possible ventilation overall microbiology was similar with the exception of significantly more staphylococcus aureus in the post - group [ table 2 ] .
while there was significantly more methicillin sensitive staphylococcus aureus ( mssa ) in the post - group , there was no difference between the two groups in rates of methicillin resistant staphylococcus aureus ( mrsa ) .
there was a trend towards less pseudomonas aeruginosa in the post - group ( 23.4% pre vs 10.9% post , p = 0.06 ) .
the groups also had similar rates of polymicrobial growth , at 39.4% in the pre chlorhexidine group and 31.3% in the post - group ( p = 0.32 ) .
microbial data was similar for patients that had bal collection on sicu day 5 or later , including a trend toward increased rates of staphylococcus aureus in the post - group , again driven by trend towards increased mssa rather than mrsa [ table 3 ] .
in addition , the rates or polymicrobial pneumonia and trend for less pseudomonas aeruginosa in the post - group were also similar for patients with bal collection on sicu day 5 or later compared to all patients regardless of bal collection day .
microorganisms for all patients microorganisms for patients with bal collected on icu day 5 or greater
our results demonstrated that the routine addition of chlorhexidine mouthwash , as part of a ventilator management bundle , was associated with decreased development of probable vap in sicu patients .
there was no difference in secondary outcomes including duration of mechanical ventilation , in - hospital mortality , icu and hospital length of stay .
to our knowledge this is the first study that used the 2013 cdc vae definitions for the diagnosis of vap to assess the impact of oral chlorhexidine use .
previously reported studies describing the use of chlorhexidine to prevent vap have yielded mixed results .
the findings in our study are consistent with a previously published study in mechanically ventilated cardiac surgery patients , in which patients who received chlorhexidine mouthwash demonstrated a 69.1% reduction in respiratory tract infections
. however , some studies infer little or no additional benefit with oral care such as prophylactic chlorhexidine in non - cardiac surgery patients , while other studies suggest that it has a positive impact on clinical outcomes . a study including patients from 3 separate icus ( medical respiratory , neurosurgical and surgical trauma ) at a university medical center found no clinical benefit to chlorhexidine prophylaxis based on development of vap through utilization of cpis .
patients that received chlorhexidine had a significantly lower cpis at day 3 , but failed to show a difference on days 5 and 7 .
a total of 547 patients were enrolled but 249 patients were evaluated on day 3 and 158 and 109 patients on days 5 and 7 , respectively .
the use of cpis to diagnose vap has been criticized because of inter - observer variability , and lower sensitivity and specificity in trauma , burn , surgical and medical populations .
although we did collect cpis scores at the time of bal collection , our primary endpoint utilized the cdc definition of probable vap and a single physician interpreted chest radiographs for all analyzed patients . in comparison to historical data , this study appeared to represent a typical sicu patient population for our institution .
overall the microbiology data was similar between groups except for the development of staphylococcus aureus which was driven by differences in rates of mssa .
patients are frequently admitted to our sicu after an acute event , which was reflected by many of our patient population primarily being admitted to the sicu upon hospital admission .
such acute events can put patients at risk for aspiration pneumonia which may explain the higher rate of mssa compared to mrsa than what is normal from the institution .
there was no difference in microbiological data for patients who had been in the icu 5 or more days when bal was obtained in total staphylococcus aureus , mssa or mrsa between groups .
however , rates of haemophilus influenza decreased significantly in those that had bal obtained after five or more days in the sicu with a high trauma population , suggesting that community acquired or aspiration pneumonia may have resulted in higher rates of early pneumonias . similar to previously published studies , we saw a reduction in gram negative infections , specifically pseudomonas aeruginosa . in regards to chlorhexidine administration
traditionally , pseudomonas aeruginosa has been the second most common cause of sicu acquired infections in our medical center .
not only was there a trend towards decreased incidence in the post - group , pseudomonas aeruginosa dropped from second most common pathogen in the pre - group to fifth most common in the post - group .
as pseudomonas aeruginosa is one of the more common pathogens to be multidrug resistant in our institution , there may be a clinical benefit to the use of chlorhexidine in regards to resistance .
although the incidence of ivac was decreased in the post - group , the organisms causing infection were similar in both groups .
this study is unique in the assessment tools utilized , specifically regarding the effective use of the updated cdc vae surveillance definition for probable and possible vap , which encompassed a standard range for temperature ( > 38c , or < 36c ) and wbc ( 12,000 cell / mm or 4,000 cell / mm ) with the initiation of a new antibiotic for 4 days or greater as it relates to infection risk .
much of the objective criteria used for these criteria were derived from research conducted by klompas et al .
this tiered approach allows clinicians to more objectively screen patients and eliminate those patients that may have been diagnosed with vap using cpis or other outdated pneumonia guidelines .
the number of probable vap cases was lower in the post - group , suggesting clinical benefit of chlorhexidine mouthwash implementation based on updated objective cdc definitions .
this study was not without limitations . while the number of patients during the study period was large , strict exclusion criteria in an attempt to obtain a homogenous population resulted in a smaller sample size than expected , with less than 160 patients total included for analysis .
the retrospective nature of this study has known inherent limitations , with reliance upon documentation in the electronic medical record .
information was captured within electronic progress notes , scanned documents and lab program , which required gathering data collection from a variety of systems .
literature evaluating the cdc 's 2013 updated vae surveillance guidelines utilized for the primary outcome of this study was not readily available at the time this study was being developed .
therefore , the validation of the updated cdc guidelines can further be supported by similar studies like this one . in addition , compliance was not assessed for the other individual vap bundle components , such as spontaneous breathing trials , which could be a potential confounder if compliance changed significantly during the time period during which this study took place .
in summary , this study shows that prophylactic chlorhexidine mouthwash in addition to the use of a vap bundle was associated with significantly lower probable vap in mechanically ventilated sicu patients compared to patients that did not receive prophylaxis .
overall , the significant reduction in probable vap was associated with a substantial reduction in pseudomonas infections in the chlorhexidine group .
furthermore , the outcomes from this study are suggestive of decreased patient cost related to antibiotic management , but prospective randomized controlled trials are needed to confirm .
| ### Summary:
: background : prevention of ventilator - associated pneumonia is a healthcare goal . although data is inconsistent , some studies suggest that oral chlorhexidine may decrease rates of pneumonia in mechanically - ventilated patients .
we sought to assess the rate of pneumonia in the surgical intensive care unit ( sicu ) pre and post implementation of routine chlorhexidine mouthwash prophylaxis.materials and methods : a retrospective cohort study was conducted , including patients between 1/1/2009 and 12/31/2009 who did not receive chlorhexidine mouthwash compared to patients that received prophylactic chlorhexidine mouthwash between 3/1/2010 and 2/28/2011 .
the primary outcome of the study was rate of probable ventilator - associated pneumonia ( vap ) for the pre - chlorhexidine implementation cohort compared to post - implementation , using the 2013 center for disease control definitions .
mechanically ventilated patients with respiratory cultures were screened for inclusion in the study .
secondary endpoints included duration of mechanical ventilation , in - hospital mortality , icu and hospital length of stay .
statistical analysis was conducted by fisher 's exact test for nominal data and mann - whitney u test for continuous data.results:a total of 1780 mechanically ventilated patients in the pre - chlorhexidine group and 1854 in the post - chlorhexidine group were screened for inclusion .
of the 601 mechanically ventilated patients that were further evaluated for inclusion ; 158 patients ( 26.3% ) had positive cultures and were included in the study ( 94 pre - group and 64 post - group ) .
the rate of probable vap was significantly decreased in the post - group compared to the pre - group ( 1.85% pre vs 0.81% post , p = 0.0082).conclusion : use of chlorhexidine mouthwash prophylaxis may reduce rates of probable vap . further study is warranted . |
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: case in the state of california in april 2009 subsequent to an outbreak in la gloria , mexico .
department of health and human services secretary charles e. johnson declared the 2009 h1n1 influenza outbreak a nationwide public health emergency on april 26 , 2009 .
department of health and human services ( dhhs ) coordinated efforts with the cdc , national institutes of health ( nih ) , and the food and drug administration ( fda ) to establish multiple surveillance systems to track the progress of the new subtype of the influenza a virus ( 2009 h1n1 influenza ) infection .
fda s center for drug evaluation and research , office of surveillance and epidemiology ( ose ) , was designated to monitor reported adverse events associated with the use of antiviral medications for the treatment and prophylaxis of influenza , and to track the national utilization patterns of these medications .
cdc s final estimates for the 2009 h1n1 pandemic in the united states indicate that from april 2009 to april 10 , 2010 , there were approximately 61 million cases of 2009 h1n1 influenza ( i.e. , approximately onesixth of the population ) , with roughly 20 million cases in children and adolescents , 35 million in adults 1864 years old , and 6 million among individuals 65 years and older .
thus , nearly onethird of the cases were in the pediatric age group , while approximately 10% of the total cases were in the elderly .
overall , the 2009 h1n1 pandemic was estimated to have caused roughly 12 470 deaths , with 10% of these deaths in children and adolescents .
the 2009 h1n1 influenza virus predominated during the pandemic , accounting for > 99% of laboratorytyped influenza through november of that year in the united states . during the 20092010 influenza season , the 2009 h1n1 influenza virus was susceptible to the antiviral class neuraminidase inhibitors ( oseltamivir and zanamivir ) but resistant to the antiviral class adamantanes ( amantadine and rimantadine ) .
ose s division of epidemiology monitored data on dispensed prescriptions for all four antiviral drugs , with a focus on those recommended for use against 2009 h1n1 influenza , oseltamivir ( by strength and form prescribed ) and zanamivir ( prescribed as an inhaler only ) , stratified by patient age .
this report summarizes outpatient antiviral prescribing in the united states from the week ending march 13 , 2009 through week ending april 23 , 2010 .
proprietary drug use databases were used by fda to conduct this analysis . as prior data had indicated that the majority of the market share for influenza antiviral sales was for oseltamivir and the majority of oseltamivir bottles ( > 90% ) were sold to outpatient retail channels of distribution during the 20082009 influenza season , we focused the analysis on outpatient prescription utilization of oseltamivir , zanamivir , rimantadine , and amantadine .
outlets within the retail market include the following pharmacy settings : chain drug stores , independent drug stores , mass merchandisers , and food stores .
outlets within the nonretail market include clinics , nonfederal hospitals , federal facilitiesm hmos , longterm care facilities , home health care , and other miscellaneous settings .
we found that antiviral sales from manufacturer / distributor to retail and nonretail settings , and dispensed outpatient retail prescription utilization sources , provided a 410 week shorter lag time for data compared to inpatient hospital discharge records of antiviral use .
outpatient retail prescription utilization sources can provide no data on whether patients are taking medications as prescribed , but were considered the best mechanism for antiviral utilization analysis .
outpatient use and patient demographics were measured from the wolters kluwer viral tracker , wolters kluwer health , and wolters kluwer pharma solutions , united states .
the wolters kluwer viral tracker database is a data source that captures adjudicated prescription claims across the united states from commercial plans , medicare part d plans , cash and medicaid claims for select influenza antiviral drugs .
drug market , and prescription data are projected to yield national estimates . from this data source ,
weekly national estimates of the number of prescriptions dispensed for oseltamivir , zanamivir , rimantadine , and amantadine were obtained for the week ending march 13 , 2009 through week ending april 23 , 2010 .
data collection is based on a reporting week that starts on saturday and ends on friday of each week with a 10day lag time .
those data were then downloaded , compiled , and analyzed . around 3540% of influenza antiviral prescriptions claims captured by the wolters
known ages were used to trend age stratifications for influenza antivirals and were assumed to be reflective of actual patient trends . the ims health , inc . , ( danbury , ct , usa ) , ims , vector one : national ( vona ) captures retail pharmacy prescriptions from retail chains , mass merchandisers , mail order pharmacies , pharmacy benefit managers , and provider groups .
vector one obtains data on over 2 billion prescriptions annually , from a sample of approximately 59 000 u.s .
as a part of the cdc s influenza epidemiology and surveillance activity for the 2009 h1n1 influenza pandemic , sentinel providers were recruited for the influenza sentinel provider surveillance network and provided reports of the number of visits for influenzalikeillnesses ( ili ) .
we overlayed the nationally projected outpatient dispensed prescription data using the wk viral tracker with national estimates of the percentage of all outpatient visits that were for ili .
this provided insight into patterns of antiviral prescribing relative to the progress of the influenza pandemic within the unites states .
with the exception of three seasons over the past 19 years ( seasons 19911992 , 19951996 , and 20032004 ) , antiviral use during the seasonal influenza outbreak usually begin to increase during the 4th quarter and peaks during the 1st quarter of each year ( figure 1 ) . during the 20082009 season
( started in the 4th quarter 2008 through and ended in the 2nd quarter 2009 ) , the seasonal peak occurred during the 1st quarter of 2009 as expected .
however , antiviral prescriptions continued to be dispensed during the 2nd and 3rd quarters of 2009 at quantities greater than previously observed .
the proportion of antiviral prescriptions dispensed during the 2nd and 3rd quarters of the previous 18 seasons ranged from 5% to 42% of 1st quarter dispensed prescriptions ; however , the proportion of antiviral prescriptions dispensed during the 2nd and 3rd quarters of 2009 was 81% and 142% of the 1st quarter prescription count .
examining weekly prescription data provides further insight into the unusually high antiviral use noted in the second and third quarters of 2009 . after declining from the 2008 to 2009 seasonal peak to a low of 8208 prescriptions during the week ending april 24 , 2009 , oseltamivirdispensed prescriptions increased to an estimated 249 106 prescriptions ( a 30fold increase ) during the week ending in may 1 , 2009 .
zanamivir experienced a ninefold increase during this same time period ( from 1631 prescriptions to an estimated 14 812 prescriptions ) . by week ending may 15 , 2009 , the use of antiviral agents decreased from this peak . following this initial spike from the h1n1 outbreak , dispensed
antiviral prescriptions for the 20092010 seasonal influenza season began to increase earlier than expected around the 2nd week of august .
the number of oseltamivirdispensed prescriptions increased to an estimated 582 387 prescriptions during the week ending in october 23 , 2009 , then dropped sharply to preseasonal flu levels by the week ending december 4 , 2009 .
prescription use continued to decline thereafter and leveledoff during the first quarter of 2010 to negligible levels by april 2010 . on a much smaller scale ,
the number of zanamivirdispensed prescriptions peaked to around 10 855 prescriptions during the week ending in october 23 , 2009 , and followed a similar pattern of decline . during the study period ,
the capsule was the more commonly dispensed formulation ( representing 86% of all oseltamivir prescriptions ) compared to the suspension formulation .
around 97% of the capsules dispensed were of the 75mg strength , with comparatively few prescriptions for the other available 30 and 45mg strengths .
based on the total of known ages , the 30 and 45mg oseltamivir capsules ( 95% ) and the suspension ( 99% ) are primarily dispensed to pediatric patients . during the study period ,
based on the total of known ages , on average , for every zanamivir prescription dispensed to pediatric patients aged 016 years , approximately two prescriptions were dispensed to adults .
around 96% of prescriptions dispensed to patients aged 016 years were to those above the age of 6 years .
rimantadine accounted for < 1% of the total influenza antiviral market during the study period .
based on the total of known ages , on average , for every rimantadine prescription dispensed to a pediatric patients aged 016 years , approximately four prescriptions were dispensed to adults .
although the majority of the 2009 h1n1 strains were resistant to rimantadine , the trend in dispensed prescriptions followed that of oseltamivir . from the week ending march 13 , 2009 , through week ending april 23 , 2010 , amantadine accounted for around 10% of the total influenza antiviral market studied .
based on the total of known ages , on average , for every amantadine prescription dispensed to pediatric patients aged 016 years , approximately eight prescriptions were dispensed to adults .
although the trend in the amount of dispensed amantadine prescriptions remained fairly steady during the 20092010 season , the trended increases in dispensed prescriptions followed that of oseltamivir .
weekly dispensing of influenza antivirals followed the same trend of weekly reports of the percentage of visits for ili by the influenza sentinel provider surveillance network ( figure 2 ) .
weekly dispensing of oseltamivir specifically to patients aged 65 years or greater followed a similar trend . projected number of antiviral prescriptions and influenzalikeillness reports , weekly march 2009april 2010 .
the influenza season begins annually in october and ends in june of the following year , peaking around february . during the 20082009 season ( 4th quarter 20082nd quarter 2009 ) , the 2009 h1n1 influenza pandemic altered this trend .
the seasonal peak occurred during the 1st quarter of 2009 but dispensed antiviral prescriptions continued through to the 2nd and 3rd quarters of 2009 .
the trend was subsequently altered for the 20092010 season , as the seasonal peak was shifted to the left , occurring earlier in the season during the 4th quarter of 2009 with decreased utilization during the 1st quarter of 2010 . after declining from the 20082009 seasonal peak by week ending april 24 , 2009 , oseltamivir weekly dispensed prescriptions increased by 30fold during the week ending in may 1 , 2009 ( from 8208 prescriptions to 249 106 prescriptions ) , and zanamivir weekly dispensed prescriptions increased by ninefold increase from 1631 prescriptions to 14 812 prescriptions .
utilization would have been expected to be low during this time ( 2nd quarter ) based on previous seasons .
this increase in weekly dispensed prescriptions nationwide coincides with the declaration of a nationwide h1n1 public health emergency by the dhhs secretary . during the 20092010 season
, there were relatively fewer infections and cases of serious illness and death with the 2009 h1n1 virus in people older than 65 , representing around 3% of weekly reports of the number of visits for ili by the influenza sentinel provider surveillance network from the week ending may 1 , 2009 , through week ending april 23 , 2010 .
the consistent community presence of the h1n1 virus heavily impacted the availability of oseltamivir during the early 20092010 seasonal peak . on september 4 , 2009 , roche laboratories ( oseltamivir manufacturer ) released a notice to providers that because of strong demand , supplies of the oral suspension as well as the 30 and 45mg capsule formulations were limited in supply and expected shortages .
roche did not expect to have additional suspension supplies until november / december 2009 and suspension shipment resumed in the first week of december 2009 .
consequently , dispensed oseltamivir suspension prescriptions for all age groups began to decline during the week ending september 25 , 2009 , and continued until the week ending december 4 , 2009 , representing a 91% decrease ( from 53 962 to 4654 prescriptions ) . during this time
, pharmacists were instructed by the manufacturer and dhhs to compound suspension from oseltamivir capsules as provided in oseltamivir product labeling dosage and administration section .
to our knowledge , this is the first comparison of weekly antiviral prescription utilization data and traditional influenza surveillance data during an influenza epidemic in the united states .
a previous analysis of influenza antiviral prescription data from cdc biosense during years 20062009 showed a pattern resembling our data , although at monthly rather than weekly increments .
this analysis found good correlation with surveillance data on emergency department visits for antiviralrelated adverse events .
in japan , an analysis of data from prior to the h1n1 pandemic showed that the weekly volume of prescriptions for neuraminidase inhibitors dispensed in community pharmacies correlated with influenza activity reported by japan s national epidemiological surveillance of infectious diseases .
hernandez et al .
described pandemic use of oseltamivir during 4th quarter 2009 in the five most populous countries of europe .
oseltamivir retail prescriptions ranged from 41 per 100 000 ( spain ) to 405 per 100 000 ( germany ) . in figure 1 ,
prescriptions for all antiinfluenza drugs peaked in the 4th quarter of 2009 , at roughly 43 million , the large majority for oseltamivir . on a percapita basis , with a u.s .
population of 307 million at the time ,
this represented approximately 1400 antiviral prescriptions per 100 000 population .
oseltamivir has dominated the influenza antiviral market share of dispensed prescriptions since approval in october 1999 .
historically , use of oseltamivir in the united states markedly increased , and use of adamantanes declined , following cdc guidelines in 2006 cautioning about viral resistance to adamantanes .
we found that oseltamivir was the primary influenza antiviral drug used during the 2009 h1n1 influenza pandemic in the united states .
the pandemic resulted in prolongation of the 20082009 season and the early peak of the 20092010 season and negatively impacted the manufacturing of the most commonly dispensed formulation to pediatric patients , oseltamivir suspension .
this resulted in the decreased availability of the suspension ( although pharmacists could compound a suspension from oseltamivir 75mg capsules ) .
for every zanamivir prescription dispensed , 30 were dispensed for oseltamivir over the entire study period . for
every rimantadine prescription dispensed , 168 were dispensed for oseltamivir during the entire study period . for
every amantadine prescription dispensed , nine were dispensed for oseltamivir during the entire study period .
weekly dispensing of the four influenza antivirals followed the same trend of weekly reports of the number of visits for ili by the influenza sentinel provider surveillance network .
the fact that the shape of the ili epidemic curve mirrored the trends in prescriptions dispensed lends credence to the ili surveillance data .
limitations of this analysis include the restriction to data on dispensed retail prescriptions ; for the reasons already discussed , we focused the analysis on that sector of the market .
another limitation is that age was missing from a large proportion of the prescriptions , which could lower the numbers of prescriptions observed among a particular age group , if that age group had disproportionately greater numbers of prescriptions with missing ages .
amantadine has an additional indication of parkinson s disease , which could account for prescriptions dispensed outside of the typical influenza season , and we do not know the proportion of the amantadine prescriptions that were for influenza specifically during the influenza season . also , we can not account for prescriptions that represented stockpiling , that is , patients filling prescriptions so that they would have drug on hand if they developed influenza symptoms or were exposed .
however , by inspection of the trends in prescriptions , it would appear that most of the prescriptions were for acute use and were not dispensed very far in advance , that is , there was little suggestion of advance stockpiling of antiviral prescriptions well ahead of the epidemic curve . in summary ,
monitoring dispensed prescriptions for antiinfluenza drugs during the influenza pandemic proved to be a useful adjunct to other influenza surveillance data and provided insights into the potential for shortages in the supply of antiviral drugs as the epidemic developed . | ### Summary:
: please cite this paper as : bordershemphill and mosholder ( 2012 ) u.s .
utilization patterns of influenza antiviral medications during the 2009 h1n1 influenza pandemic .
influenza and other respiratory viruses 6(601 ) , e129e133 .
background the 2009 h1n1 influenza pandemic in the united states occurred from april 2009 to april 2010 .
the 2009 h1n1 influenza virus was susceptible to neuraminidase inhibitors ( oseltamivir and zanamivir ) .
objectives to characterize the 2009 h1n1 influenza pandemic in the united states from april 2009 to april 2010 using weekly influenza antiviral prescription utilization data and the cdc s weekly reports of the number of visits for influenzalikeillnesses by the influenza sentinel provider surveillance network .
methods a proprietary outpatient data source used by the fda , which captures adjudicated u.s .
prescription claims for select influenza antiviral drugs , was used to conduct this analysis .
data were extracted weekly and analyzed for surveillance during the pandemic .
results were compiled at the end of the pandemic .
results oseltamivir has dominated the u.s .
influenza antiviral market share of dispensed prescriptions since approval in october 1999 and was the primary influenza antiviral drug used during the 2009 h1n1 influenza pandemic .
however , commercial availability of the suspension formulation of oseltamivir was reduced by high demand during the pandemic .
dispensed prescription trends of other influenza antiviral medications studied followed that those of oseltamivir , even antivirals for which the 2009 h1n1 strains showed resistance .
conclusion weekly prescription utilization of all influenza antivirals used to treat influenza during the seasonal influenza outbreak followed the same trend of weekly reports of the number of visits for influenzalikeillnesses ( ili ) by the influenza sentinel provider surveillance network .
the ili epidemic curve resembled dispensed antiviral prescription trends ( both overall and stratified by age ) , providing some corroboration for the surveillance data . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: nerve growth factor ( ngf ) was the first discovered member of a family of factors noted to prevent neuronal death called the neurotrophins.1 levi - montalcini found that ngf was produced in significant levels in mouse salivary glands , and it could prevent apoptosis of neurons in culture.2 ngf and one of its receptors , trka , are predominantly found on sympathetic neurons.3 during development , ngf is the factor that regulates neuronal remodeling to establish the precise connections of neuron to target .
the target produces ngf that is taken up by the nerve terminal and transported retrogradely to the cell body .
the neuron becomes anti - apoptotic after ngf has reached the cell body.4 in the establishment of target - neuron connections , sensory and sympathetic nerves often will compete for available ngf.5 ngf actions are mediated by two receptors , p75 and neurotrophic tyrosine kinase receptor type 1 ( trka ) .
ngf is produced as a proneurotrophin ( pro - ngf ) , which preferentially binds to p75 .
activation of p75 can activate three major signaling pathways , including nfb , c - jun , and rhoa.6 p75 is a low - affinity receptor for ngf and is a member of the tumor necrosis factor superfamily . due to the activation of the c - jun and rhoa , ngf binding to p75 is considered to be a predominantly pro - apoptotic event .
in contrast to the binding of ngf to p75 , ngf binds to trka with high affinity .
the major pathways activated by trk receptors are ras , rac , pi3k , plc-1.7 we have previously shown that ngf promotes choroidal endothelial cell migration through pi3k signaling.8 activation of ras and downstream effectors promotes choroidal cell proliferation.8 in addition , work on cd34 + cells has demonstrated that ngf treatment will increase both migration and tube formation ( key factors needed for wound healing ) via phosphorylation of trka and activation of pi3k and ras ( jadhao et al unpublished results ) .
thus , increased ngf binding to trka will promote a neuroprotective effect and should promote effective wound healing .
nerve growth factor ( ngf ) was the first discovered member of a family of factors noted to prevent neuronal death called the neurotrophins.1 levi - montalcini found that ngf was produced in significant levels in mouse salivary glands , and it could prevent apoptosis of neurons in culture.2 ngf and one of its receptors , trka , are predominantly found on sympathetic neurons.3 during development , ngf is the factor that regulates neuronal remodeling to establish the precise connections of neuron to target .
the target produces ngf that is taken up by the nerve terminal and transported retrogradely to the cell body .
the neuron becomes anti - apoptotic after ngf has reached the cell body.4 in the establishment of target - neuron connections , sensory and sympathetic nerves often will compete for available ngf.5 ngf actions are mediated by two receptors , p75 and neurotrophic tyrosine kinase receptor type 1 ( trka ) .
ngf is produced as a proneurotrophin ( pro - ngf ) , which preferentially binds to p75 .
activation of p75 can activate three major signaling pathways , including nfb , c - jun , and rhoa.6 p75 is a low - affinity receptor for ngf and is a member of the tumor necrosis factor superfamily . due to the activation of the c - jun and rhoa , ngf binding to p75 is considered to be a predominantly pro - apoptotic event .
in contrast to the binding of ngf to p75 , ngf binds to trka with high affinity .
the major pathways activated by trk receptors are ras , rac , pi3k , plc-1.7 we have previously shown that ngf promotes choroidal endothelial cell migration through pi3k signaling.8 activation of ras and downstream effectors promotes choroidal cell proliferation.8 in addition , work on cd34 + cells has demonstrated that ngf treatment will increase both migration and tube formation ( key factors needed for wound healing ) via phosphorylation of trka and activation of pi3k and ras ( jadhao et al unpublished results ) .
thus , increased ngf binding to trka will promote a neuroprotective effect and should promote effective wound healing .
while ngf is required for the health of sympathetic neurons , norepinephrine signaling may also play a role in neuroprotection and wound healing .
norepinephrine signals through activation of either -adrenergic receptors or -adrenergic receptors . within the eye ,
the presence of norepinephrine and noradrenergic receptors has been noted around the blood vessels of the choroid and iris.9 more recently , work has shown that 2-adrenergic receptors are present in the corneal endothelial cells.10,11 the presence and role of adrenergic receptors in the retina is a bit more controversial .
laties and jacobowitz did not observe sympathetic innervation in the retina by immunohistochemical analysis.12 however , furukawa , using immunohistochemical methods as well as transmission and scanning electron microscopy , demonstrated that the retina receives sympathetic innervation.13 since then , others have demonstrated the presence of dopamine--hydroxylase , the enzyme that converts dopamine to norepinephrine , in specific layers of the retina.14,15 activation of -adrenergic receptors in the retina stimulates the accumulation of cyclic adenosine monophosphate ( camp).16 we have shown that surgical removal of the superior cervical ganglion , which eliminates sympathetic neurotransmission to all cranial targets , produces increased basement membrane thickening and pericyte loss in the retinal vasculature and leads to the activation of mller cells ( glial cells of the retina).17,18 the functional role of -adrenergic receptors and -adrenergic receptors in the eye are target - specific . within the choroid and iris , -adrenergic receptors mediate vasoconstriction , while -adrenergic receptor stimulation produces vasodilation of the vasculature.19,20 a key role for both -adrenergic receptor and -adrenergic receptor pharmacology in the eye is in the management of glaucoma . for the management of glaucoma
, agents can be used to either decrease the production of aqueous humor ( -adrenergic receptor antagonists or -adrenergic receptor agonists ) or increase outflow of aqueous humor ( prostaglandins).2123 the functional role for adrenergic receptor signaling in the retina is not clear .
stimulation of -adrenergic receptors by norepinephrine induces an increase in camp levels and phosphorylation of protein kinase a ( pka ) .
pka is then able to transduce into the nucleus of the cell to bind camp - responsive element binding ( creb ) complexes to induce transcription of a number of proteins .
in contrast to -adrenergic receptors , which signal predominantly through g - protein stimulatory ( gs ) , -adrenergic receptors activate gq , producing an increase in phospholipase c and calcium signaling . the ability of adrenergic receptors to regulate aqueous humor production and blood flow in the eye is directly related to which receptor subtype is activated .
based on the increased understanding of adrenergic receptor signaling , a large number of pharmaceutics have been developed for the eye .
fortunately , the eye allows for topical delivery , which eliminates problems associated with systemic effects of adrenergic receptors on the vasculature of other critical organs ( heart , lungs ) . based on our understanding of the cellular localization , functions , and signaling of both ngf and the neurotransmitters of the sympathetic nervous system ,
pharmaceutical companies have developed topical delivery methods for both ngf and adrenergic receptor agents for a number of disabling ocular disorders .
a number of studies have been done in both humans and in animal models to investigate the ability of topical ngf to accelerate the healing process in cornea ulcers .
investigations in dogs demonstrated that ngf and trka are present in normal dogs tears , corneal epithelium , and the lacrimal gland.24 in dogs , topical treatment with ngf did not modulate corneal healing rates.24 in contrast to the work in dogs , esquenazi et al ( 2005 ) found that topical ngf to rabbits in combination with docosahexenoic acid ( dha ) after photorefractive keratectomy ( prk ) was associated with increased corneal epithelial cell proliferation and increased corneal surface area , in contrast to no treatment , ngf treatment alone , or dha treatment alone.25 while topical ngf has been met with some obstacles for corneal healing in animal models of ocular disease , work on humans with corneal disorders has provided much more promising results .
lambiase et al ( 2007 ) reported that corneal ulcers produced from a variety of insults ( diabetes mellitus , radiotherapy , trauma , etc ) , which were unresponsive to traditional therapies for neurotrophic ketatopathy , were treated with topical murine ngf ( 200 ug / ml ) for two hours for the first two days , followed by one drop six times daily until the ulcer healed.26 remarkable results were obtained in these patients ; all patients has resolution of the corneal ulcer after 26 11 days of ngf treatment .
limited side effects were observed and only two patients had a relapse of the ulcer during follow - up , which occurred over 72 months.26 in a recent review by aloe et al ( 2008 ) , data on over 200 patients treated with topical ngf was presented which clearly demonstrates that ngf treatment promotes an accelerated healing action in the cornea without side effects.27 the role of sympathetic nerves and neurotransmission has also been investigated for their ability to resolve corneal ulcers .
work in rats undergoing surgical superior cervical ganglionectomy revealed that ocular sympathetic nerves stimulate corneal epithelial cell proliferation under both normal conditions and during times of corneal wounding .
this increase in proliferation appears to be related to release of norepinephrine.28 since work in animal models suggested that adrenergic receptor agents may promote corneal wound healing and the cornea possesses an abundance of -adrenergic receptors in both the epithelium and endothelium of the cornea,29 work had been done to evaluate the ability of 2-adrenergic receptor antagonism to regulate corneal wound healing .
in fact , 2-adrenergic receptor antagonism increased corneal wound healing by 16%.11,30 while the mechanism is not clear since norepinephrine is suggested to increase epithelial cell proliferation in animals , work in humans suggests that a blockade of 2-adrenergic receptors in the cornea with topical agents may provide a novel therapeutic option for corneal ulcers .
the pharmacological management of glaucoma has increased immensely in the last several decades , improved by the increased understanding of the ocular hemo / aqueous humor dynamics .
ngf has been reported to reduce retinal ganglion cell loss , which , left unchecked , will lead to loss of retinal functions .
elevated intraocular pressure ( as occurs in glaucoma ) in rats produced a significant loss of ngf , which was correctable through topical ngf treatment.31 to induce glaucoma in a rat model , hypertonic saline is injected into the eye , raising intraocular pressure ( iop ) to 35 mmhg as compared to 24 mmhg in the untreated eye.32 in the rat model of glaucoma , topical ngf ( 200 ug / ml ) applied four times daily for seven weeks prevented retinal ganglion cell death likely through an increase in the bcl-2/bax ratio.32 in the same study , three human patients with severe glaucoma were treated with topical ngf for three months .
ngf treatment improved the functional responsiveness of the retina , as measured by perg p50 and ver p100 values , with better neural conduction .
this positive response to ngf treatment likely occurs as trka phosphorylation increases bcl-2 levels , a key anti - apoptotic protein .
the standard of care for many glaucoma patients are adrenergic receptor agents . this has occurred since work in monkeys demonstrated with timolol ( a typical nonselective -adrenergic receptor antagonist ) reduced aqueous humor levels by 50%.33
these results suggest that antagonism of -adrenergic receptors reduced aqueous humor levels , producing a decrease in intraocular pressure .
-adrenergic receptor agents act in much the same way as -adrenergic receptor antagonists to reduce aqueous humor levels in the eye .
we have previously demonstrated that ngf treatment of human choroidal endothelial cells in culture promoted cell proliferation and migration through the pi3k and erk1/2 pathway.8 in contrast to the limited information on ngf in the choroid , much work has been done on adrenergic receptor agents in the choroid , likely due to the predominant vasculature of the ciliary arteries of the choroid .
we have demonstrated that stimulation of -adrenergic receptor agonists on the vortex vein region of the choroid produced vasoconstriction.20 work in the rabbit has shown that neither betaxolol nor timolol had a significant effect on choroidal pressure - flow relationships , but that both do reach the systemic circulation.34 work on the posterior ciliary microarteries ( many of them flowing through the choroid ) demonstrated that these particular vessels do not have appreciable -adrenergic receptor activity .
however , betaxolol and propranolol likely produce vasorelaxation through blockade of ca channels , rather than true -adrenergic receptor activities.35 these results suggest that adrenergic receptor agents , particularly -adrenergic receptor antagonists , may be used to influence choroidal blood flow .
much of the work on ngf in the retina is focused on its potential to protect retinal ganglion cells and the optic nerve head in diseases , such as diabetes , carotid artery occlusion , and glaucoma .
topical conjunctival administration of ngf ( 200 ug / ml ) prevented cell death of retinal ganglion cells induced by hypertension or ischemia in rats.36 ngf may reach the retina as a topical treatment since the final protein product ngf is only approximately 1315 kd .
however , the exact mechanism of ngf movement into the retina has not been investigated . using the type i diabetic rat model , ali et al ( 2008 ) demonstrated that peroxynitrite produced retinal degeneration through inhibition of ngf prosurvival activities.37 the increased glucose in diabetes produces free radical and peroxynitrite in the retina .
these authors found that increased peroxynitrite led to nitration of the trka receptor and enhanced p75 expression , producing increased apoptosis.37 similarly , work on a carotid artery occlusion model in rats demonstrated that an intravitreal injection of ngf protected retinal ganglion cells through modulation of the bax / bcl-2 ratio to promote the prosurvival actions of ngf.38 while ngf does promote neuronal survival , some negative effects have also been reported . using the oxygen - induced retinopathy model of proliferative diabetic retinopathy , liu et al ( 2010 ) found that ngf promoted retinal neovascularization , which was mediated through activities of the trka receptor.39 since retinal neovascularization is a negative consequence in most cases , ngf actions in this setting are not positive .
nonetheless , work has increased on the role of ngf to prevent retinal neuronal apoptosis . since this is likely dependent on which ngf receptor is activated ( trka over p75 ) ,
have been done following intraocular injections . the ability of ngf to reach the retina as a topical treatment is still under investigation .
the role of topical adrenergic receptor agents in the retina has been previously focused on blood flow regulation .
work in humans has demonstrated that epinephrine treatment increased macular blood flow by 8%.40 work using different classes of -adrenergic receptor antagonists showed that all classes increased blood velocities in retinal and epiretinal capillaries of healthy human volunteers.41 while -adrenergic receptor antagonists increase retinal blood flow , work has also suggested that this may be due primarily to the reduction in intraocular pressure and ca channel actions , rather than a direct action on the -adrenergic receptors.42 the role of -adrenergic receptors in the regulation of glaucoma is not clear .
one of the mechanisms of action for betaxolol , one of the most potent -adrenergic receptor antagonists for glaucoma , is its ability to alter calcium levels.43,44 in a recent review , osborne reported that the beneficial effects of -adrenergic receptor blockers in glaucoma therapy do not appear to involve their actions on -adrenergic receptors.45 these findings suggest that the role of -adrenergic receptor antagonists as neuroprotective drugs for glaucoma therapy may be related to non--adrenergic receptor actions of these agents . in diabetic retinopathy , two studies have shown that -adrenergic receptor antagonists do not reduce diabetic retinopathy , in spite of reduced systemic blood pressure.46,47 therefore , previous work on -adrenergic receptor antagonists in the retina suggests that they do not prevent diabetic retinopathy in rodents .
nonetheless , the downstream effects of -adrenergic receptor blockade mediated by receptor signaling in the retina are not known .
work in our lab has recently reported that blockade of -adrenergic receptor signaling in the normal retina is detrimental , as evidenced by the reduced b - wave amplitude of the electroretinogram ( erg ) .
this agrees with previous work in our lab , which showed positive effects on the retina following application of -adrenergic receptor agonists in reducing inflammatory marker levels.4851 while we have data that systemic application of -adrenergic receptor antagonists produce retinal dysfunction , we have also recently found that -adrenergic receptor agonists are beneficial to the retina . using the type i diabetic rat model
, we demonstrated that topical isoproterenol ( 50 mm given once daily ) inhibited the functional , biochemical , and histological manifestations of diabetic retinopathy .
isoproterenol inhibited the formation of degenerate capillaries , prevented apoptosis of cells in the ganglion cell layer , and decreased tumor necrosis factor ( tnf ) levels over the 8-month study ( jiang et al in press ) .
a number of studies have been done in both humans and in animal models to investigate the ability of topical ngf to accelerate the healing process in cornea ulcers .
investigations in dogs demonstrated that ngf and trka are present in normal dogs tears , corneal epithelium , and the lacrimal gland.24 in dogs , topical treatment with ngf did not modulate corneal healing rates.24 in contrast to the work in dogs , esquenazi et al ( 2005 ) found that topical ngf to rabbits in combination with docosahexenoic acid ( dha ) after photorefractive keratectomy ( prk ) was associated with increased corneal epithelial cell proliferation and increased corneal surface area , in contrast to no treatment , ngf treatment alone , or dha treatment alone.25 while topical ngf has been met with some obstacles for corneal healing in animal models of ocular disease , work on humans with corneal disorders has provided much more promising results .
lambiase et al ( 2007 ) reported that corneal ulcers produced from a variety of insults ( diabetes mellitus , radiotherapy , trauma , etc ) , which were unresponsive to traditional therapies for neurotrophic ketatopathy , were treated with topical murine ngf ( 200 ug / ml ) for two hours for the first two days , followed by one drop six times daily until the ulcer healed.26 remarkable results were obtained in these patients ; all patients has resolution of the corneal ulcer after 26 11 days of ngf treatment .
limited side effects were observed and only two patients had a relapse of the ulcer during follow - up , which occurred over 72 months.26 in a recent review by aloe et al ( 2008 ) , data on over 200 patients treated with topical ngf was presented which clearly demonstrates that ngf treatment promotes an accelerated healing action in the cornea without side effects.27 the role of sympathetic nerves and neurotransmission has also been investigated for their ability to resolve corneal ulcers .
work in rats undergoing surgical superior cervical ganglionectomy revealed that ocular sympathetic nerves stimulate corneal epithelial cell proliferation under both normal conditions and during times of corneal wounding .
this increase in proliferation appears to be related to release of norepinephrine.28 since work in animal models suggested that adrenergic receptor agents may promote corneal wound healing and the cornea possesses an abundance of -adrenergic receptors in both the epithelium and endothelium of the cornea,29 work had been done to evaluate the ability of 2-adrenergic receptor antagonism to regulate corneal wound healing .
in fact , 2-adrenergic receptor antagonism increased corneal wound healing by 16%.11,30 while the mechanism is not clear since norepinephrine is suggested to increase epithelial cell proliferation in animals , work in humans suggests that a blockade of 2-adrenergic receptors in the cornea with topical agents may provide a novel therapeutic option for corneal ulcers .
the pharmacological management of glaucoma has increased immensely in the last several decades , improved by the increased understanding of the ocular hemo / aqueous humor dynamics .
ngf has been reported to reduce retinal ganglion cell loss , which , left unchecked , will lead to loss of retinal functions .
elevated intraocular pressure ( as occurs in glaucoma ) in rats produced a significant loss of ngf , which was correctable through topical ngf treatment.31 to induce glaucoma in a rat model , hypertonic saline is injected into the eye , raising intraocular pressure ( iop ) to 35 mmhg as compared to 24 mmhg in the untreated eye.32 in the rat model of glaucoma , topical ngf ( 200 ug / ml ) applied four times daily for seven weeks prevented retinal ganglion cell death likely through an increase in the bcl-2/bax ratio.32 in the same study , three human patients with severe glaucoma were treated with topical ngf for three months .
ngf treatment improved the functional responsiveness of the retina , as measured by perg p50 and ver p100 values , with better neural conduction .
this positive response to ngf treatment likely occurs as trka phosphorylation increases bcl-2 levels , a key anti - apoptotic protein .
the standard of care for many glaucoma patients are adrenergic receptor agents . this has occurred since work in monkeys demonstrated with timolol ( a typical nonselective -adrenergic receptor antagonist ) reduced aqueous humor levels by 50%.33
these results suggest that antagonism of -adrenergic receptors reduced aqueous humor levels , producing a decrease in intraocular pressure .
-adrenergic receptor agents act in much the same way as -adrenergic receptor antagonists to reduce aqueous humor levels in the eye .
we have previously demonstrated that ngf treatment of human choroidal endothelial cells in culture promoted cell proliferation and migration through the pi3k and erk1/2 pathway.8 in contrast to the limited information on ngf in the choroid , much work has been done on adrenergic receptor agents in the choroid , likely due to the predominant vasculature of the ciliary arteries of the choroid .
we have demonstrated that stimulation of -adrenergic receptor agonists on the vortex vein region of the choroid produced vasoconstriction.20 work in the rabbit has shown that neither betaxolol nor timolol had a significant effect on choroidal pressure - flow relationships , but that both do reach the systemic circulation.34 work on the posterior ciliary microarteries ( many of them flowing through the choroid ) demonstrated that these particular vessels do not have appreciable -adrenergic receptor activity . however , betaxolol and propranolol likely produce vasorelaxation through blockade of ca channels , rather than true -adrenergic receptor activities.35 these results suggest that adrenergic receptor agents , particularly -adrenergic receptor antagonists , may be used to influence choroidal blood flow .
much of the work on ngf in the retina is focused on its potential to protect retinal ganglion cells and the optic nerve head in diseases , such as diabetes , carotid artery occlusion , and glaucoma .
topical conjunctival administration of ngf ( 200 ug / ml ) prevented cell death of retinal ganglion cells induced by hypertension or ischemia in rats.36 ngf may reach the retina as a topical treatment since the final protein product ngf is only approximately 1315 kd .
however , the exact mechanism of ngf movement into the retina has not been investigated . using the type i diabetic rat model , ali et al ( 2008 )
demonstrated that peroxynitrite produced retinal degeneration through inhibition of ngf prosurvival activities.37 the increased glucose in diabetes produces free radical and peroxynitrite in the retina .
these authors found that increased peroxynitrite led to nitration of the trka receptor and enhanced p75 expression , producing increased apoptosis.37 similarly , work on a carotid artery occlusion model in rats demonstrated that an intravitreal injection of ngf protected retinal ganglion cells through modulation of the bax / bcl-2 ratio to promote the prosurvival actions of ngf.38 while ngf does promote neuronal survival , some negative effects have also been reported . using the oxygen - induced retinopathy model of proliferative diabetic retinopathy , liu et al ( 2010 ) found that ngf promoted retinal neovascularization , which was mediated through activities of the trka receptor.39 since retinal neovascularization is a negative consequence in most cases , ngf actions in this setting are not positive .
nonetheless , work has increased on the role of ngf to prevent retinal neuronal apoptosis .
since this is likely dependent on which ngf receptor is activated ( trka over p75 ) , additional work is needed . all current work on ngf actions in the retina have been done following intraocular injections . the ability of ngf to reach the retina as a topical treatment is still under investigation .
the role of topical adrenergic receptor agents in the retina has been previously focused on blood flow regulation .
work in humans has demonstrated that epinephrine treatment increased macular blood flow by 8%.40 work using different classes of -adrenergic receptor antagonists showed that all classes increased blood velocities in retinal and epiretinal capillaries of healthy human volunteers.41 while -adrenergic receptor antagonists increase retinal blood flow , work has also suggested that this may be due primarily to the reduction in intraocular pressure and ca channel actions , rather than a direct action on the -adrenergic receptors.42 the role of -adrenergic receptors in the regulation of glaucoma is not clear .
one of the mechanisms of action for betaxolol , one of the most potent -adrenergic receptor antagonists for glaucoma , is its ability to alter calcium levels.43,44 in a recent review , osborne reported that the beneficial effects of -adrenergic receptor blockers in glaucoma therapy do not appear to involve their actions on -adrenergic receptors.45 these findings suggest that the role of -adrenergic receptor antagonists as neuroprotective drugs for glaucoma therapy may be related to non--adrenergic receptor actions of these agents . in diabetic retinopathy , two studies have shown that -adrenergic receptor antagonists do not reduce diabetic retinopathy , in spite of reduced systemic blood pressure.46,47 therefore , previous work on -adrenergic receptor antagonists in the retina suggests that they do not prevent diabetic retinopathy in rodents .
nonetheless , the downstream effects of -adrenergic receptor blockade mediated by receptor signaling in the retina are not known .
work in our lab has recently reported that blockade of -adrenergic receptor signaling in the normal retina is detrimental , as evidenced by the reduced b - wave amplitude of the electroretinogram ( erg ) .
this agrees with previous work in our lab , which showed positive effects on the retina following application of -adrenergic receptor agonists in reducing inflammatory marker levels.4851 while we have data that systemic application of -adrenergic receptor antagonists produce retinal dysfunction , we have also recently found that -adrenergic receptor agonists are beneficial to the retina . using the type i diabetic rat model
, we demonstrated that topical isoproterenol ( 50 mm given once daily ) inhibited the functional , biochemical , and histological manifestations of diabetic retinopathy .
isoproterenol inhibited the formation of degenerate capillaries , prevented apoptosis of cells in the ganglion cell layer , and decreased tumor necrosis factor ( tnf ) levels over the 8-month study ( jiang et al in press ) .
topical delivery of ngf and adrenergic receptor agents has provided physicians with new options for pharmacological management of glaucoma and corneal ulcers .
work is ongoing for the role of topical ngf or adrenergic receptor agents for the posterior eye , including the choroid and retina .
recent work is investigating a potential role for ngf in therapies for diabetic retinopathy through direct actions or through actions using stem cells for prevention of retinal ischemia ( cd34 positive cells ) .
topical adrenergic receptor therapies for the retina in diabetic retinopathy are ongoing , as well as increasing the understanding of the mechanisms of -adrenergic receptor antagonist effectiveness in ganglion cell health in glaucoma .
hopefully in the future , work on topical ngf and adrenergic receptor agents in the retina can be translated to human patients as easily as it has for corneal ulcers and glaucoma therapy . | ### Summary:
: topical application of nerve growth factor ( ngf ) and adrenergic receptor pharmaceutics are currently in use for corneal ulcers and glaucoma .
a recent interest in the neuroprotective abilities of ngf has led to a renewed interest in ngf as a therapeutic for retinal and choroidal diseases . ngf can promote cell proliferation through actions of the trka receptor or promote apoptosis through receptor p75ntr .
this understanding has led to novel interest in the role of ngf for diseases of the posterior eye .
the role of -adrenergic receptor agonists and antagonists for treatments of glaucoma , diabetic retinopathy , and their potential mechanisms of action , are still under investigation .
this review discusses the current knowledge and applications of topical ngf and adrenergic receptor drugs for ocular disease . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: in 1985 , the problems of option pricing and replication with transaction costs were firstly examined by leland .
because of infinite variance of geometric brownian motion process , transaction costs will become infinite , thus the arbitrary argument used by black - scholes to price options can no longer be used .
barles and soner considered the difference between the maximum utility from final wealth when there is no option liability and when there is such a liability .
they derived the nonlinear black - scholes equation satisfied by the option value by using the utility maximization theory . considering both transaction costs and the risk from a volatile portfolio , in 2005 , jandaka and evovi got another more complicated model .
the influence of paying transaction costs and discontinuous change of stock price on option value was studied by amster et al . .
under a stochastic volatility process , mariani et al . investigated the option pricing problem with transaction cost and derived the pricing model .
meanwhile they got numerical solutions by using the finite difference method . as a kind of exotic options , the holder of lookback option could look back on the evolution process of underlying assets during the life of option at maturity .
it is one kind of path - dependent options where the payoff is based on the maximum or the minimum of the underlying asset price during the drift of the option . in 1979 ,
they obtained explicit formulas of various european lookback options and also provided some results for the american counterparts by means of probability method . with underlying asset price following geometric brownian motion ,
many empirical studies have shown that distribution of asset price is not entirely lognormal , and the probability density function of its logarithm yield tends to have the feature of fat - tailedness , so geometric brownian motion processes do not accord with the realistic environment . for characteristics of self - similarity ,
fat tails , and long - term dependence , fractional brownian motion ( fbm ) becomes an effective tool to describe the stock price process instead of geometric brownian motion .
fbm is neither a markov process nor a semimartingale , so stochastic analysis theory for semimartingale can not be applied directly . in incomplete markets , arbitrage opportunities will exist .
a considerable number of arbitrage strategies for fbm have been provided by rogers , shiryaev , salopek , and cheridito . in 2012 , gu et al . dealt with the problem of discrete time option pricing in the presence of transaction costs by a time - changed geometric fractional brownian motion model . through a mean self - financing delta - hedging argument
, they obtained the pricing formula for the european call option in discrete time setting .
then a three - dimensional nonlinear mathematical pricing model for lookback put option value with fixed transaction costs will be established .
but the reduced model is still nonlinear , so it is not easy to get the analytic solution .
so we get its numerical solution by constructing a crank - nicolson numerical scheme for the transformed model .
finally , we analyze the effectiveness of the numerical scheme and the influence of parameters on lookback put option value .
let h be a constant belonging to ( 0,1 ) . a fractional brownian motion ( b(t))t0 of hurst index h is a continuous and centered gaussian process with covariance function
( 1)ebh(t)bh(s)=12t2h+s2hts2h.for h = 0.5 , the fbm is then a standard brownian motion . by definition 1
we obtain that a standard fbm b(t ) has the following properties.(i)b(0 ) = 0 and e[b(t ) ] = 0 for all t 0;(ii)b(t ) has homogeneous increments ; that is , b(t + s ) b(s ) has the same law of b(t ) for s , t 0;(iii)b(t ) is a gaussian process and e[(b(t ) ) ] = t , t 0 , for all h ( 0,1);(iv)b(t ) has continuous trajectories.the fbm has long - term dependency for h ( 0.5,1 ) and is antisustainable for h ( 0,0.5 ) . for h
0.5 , it is neither a markov process nor semimartingale , so the classical it 's calculus can not be used to define a fully stochastic calculus for fbm .
lin and decreusefond and stnel developed the stochastic calculus of variations under fbm model , but shiryaev investigated that there exists arbitrage chance in the market .
hu and ksendal presented the fractional it 's calculus based on the wick integration driven by fbm .
for more details about fbm , interested readers may refer to hu and peng .
a fractional brownian motion ( b(t))t0 of hurst index h is a continuous and centered gaussian process with covariance function
( 1)ebh(t)bh(s)=12t2h+s2hts2h . for h = 0.5 ,
we obtain that a standard fbm b(t ) has the following properties.(i)b(0 ) = 0 and e[b(t ) ] = 0 for all t 0;(ii)b(t ) has homogeneous increments ; that is , b(t + s ) b(s ) has the same law of b(t ) for s , t 0;(iii)b(t ) is a gaussian process and e[(b(t ) ) ] = t , t 0 , for all h ( 0,1);(iv)b(t ) has continuous trajectories .
b(0 ) = 0 and e[b(t ) ] = 0 for all t 0 ; b(t ) has homogeneous increments ; that is , b(t + s ) b(s ) has the same law of b(t ) for s , t 0 ; b(t ) is a gaussian process and e[(b(t ) ) ] = t , t 0 , for all h ( 0,1 ) ; b(t ) has continuous trajectories .
the fbm has long - term dependency for h ( 0.5,1 ) and is antisustainable for h ( 0,0.5 ) . for h
0.5 , it is neither a markov process nor semimartingale , so the classical it 's calculus can not be used to define a fully stochastic calculus for fbm .
lin and decreusefond and stnel developed the stochastic calculus of variations under fbm model , but shiryaev investigated that there exists arbitrage chance in the market .
hu and ksendal presented the fractional it 's calculus based on the wick integration driven by fbm .
consider a financial market with two primitive securities , namely , a risky asset st and a risk - free bond bt .
we will need the following assumptions.(i)the securities trading is carried out continuously with short selling allowed;(ii)suppose vt shares of the traded stock are bought ( vt > 0 ) and sold ( vt < 0 ) at the price st .
then a proportion of transaction cost is given by | vt | st in either buying or selling , where > 0 is the fixed transaction cost rate.(iii)there exists no arbitrage opportunities and the portfolio 's expected rate is the risk - free interest rate r , where r is a constant.(iv)the portfolio is revised every time interval t , where t is a finite and fixed time step.the price process bt of risk - free debt evolves over time as
( 2)bt = ert , b0=1 .
suppose that the price process st of the risky share evolves over time as
( 3)dst = rstdt+stdbh(t ) , s0=s>0 ,
where indicates the volatility of the stock price .
the securities trading is carried out continuously with short selling allowed ; suppose vt shares of the traded stock are bought ( vt > 0 ) and sold ( vt < 0 ) at the price st .
then a proportion of transaction cost is given by | vt | st in either buying or selling , where > 0 is the fixed transaction cost rate .
there exists no arbitrage opportunities and the portfolio 's expected rate is the risk - free interest rate r , where r is a constant .
the portfolio is revised every time interval t , where t is a finite and fixed time step .
in this section , we adopt leland hedging strategy to derive a model for lookback option price .
the following lemma gives fractional it 's differential rule which takes great value in deriving the formula .
consider the stochastic differential equation
( 4)dst=t,dt+t,dbht .
here for t 0 , (t , ) and (t , ):[0 , t ] r r are two stochastic processes .
assume that a two - variable function f(t , st):[0 , t ] r r has uniformly continuous partial derivatives f/t , f/st , f/st . then for h ( 0,1 ) , we have
( 5)dft , st=tf(t , st)dt+stf(t , st)(t,)dt + stft , stt,dbht + h2st2ft , st2t,t2h1dt .
consider the stochastic differential equation
( 4)dst=t,dt+t,dbht .
here for t 0 , (t , ) and (t , ):[0 , t ] r r are two stochastic processes .
r r has uniformly continuous partial derivatives f/t , f/st , f/st . then for h ( 0,1 ) , we have
( 5)dft , st=tf(t , st)dt+stf(t , st)(t,)dt + stft , stt,dbht + h2st2ft , st2t,t2h1dt .
let vt = v(st , jt , t ) which denotes the value of the option at time t the corresponding payoff jt = max0utsu , where st satisfies ( 3 ) .
the following theorem gives the model for the value of lookback put option with transaction costs .
theorem 3 . the pricing model for the value of lookback put option with transaction costs under fractional brownian motion process is given as
( 6)vtt+12~2st22vtst2+rsvtstrvt=0,vst , jt , t = jtst , 0stjt<,vtjtst = jt=0 .
0tt ,
where ~2=22ht2h-1-lehsign(vss ) , leh=2/(/)th-1 , t is the hedging time interval .
the pricing model for the value of lookback put option with transaction costs under fractional brownian motion process is given as
( 6)vtt+12~2st22vtst2+rsvtstrvt=0,vst , jt , t = jtst , 0stjt<,vtjtst = jt=0 .
0tt ,
where ~2=22ht2h-1-lehsign(vss ) , leh=2/(/)th-1 , t is the hedging time interval .
prooffor the option purchaser , a hedging portfolio t is constructed : one long position of lookback put option and short t shares of stock ; then the value of the portfolio at the current time t is t = vt tst .
assume that the trade occurs only at times t and t + t where t denotes the hedging time interval .
then over a small time interval t , the change in value of the portfolio will be
( 7)t=vttstvtst .
the stochastic partial differential equation ( 3 ) can be shown as
( 8)st = rstt+stbh(t ) .
by using discrete form of lemma 2
, we can get
( 9)vt=vtt+rstvtst+h2t2h1st22vtst2t + stvtstbht+vtjtjt .
substituting ( 9 ) into ( 7 ) yields
( 10)t=vtt+h2st2t2h12vtst2t+vtsttst + vtjtjtvtst .
in order to eliminate risk ,
so in the same interval t , the traded shares of stock are
( 11)vt=vst(st+t , jt+t , t+t)vst(st , jt , t)2vst2(st , jt , t)stbh(t)+2vtstjtjt .
since jt is not differentiable , we need to approximate it as
( 12)jnt=1t0tsnd1/n , 0t ;
then
( 13)njnn1tdjndt = stnjnntt , limn jnt = max0t s=jt .
we use jn(t ) instead of path dependence variable jt ; since st jt , we can get
( 14)st / jnn1stjnnt0 n.
consequently , from ( 11)(15)vt2vst2(st , jt , t)stbh(t ) .
the transaction costs is as follows :
( 16)vtst=2vst2(st , jt , t)st2bh(t)=st22vst2(st , jt , t)bh(t ) .
according to the definition 1 , we know that
( 17)bht = bht+tbht~n0,t2h .
therefore
( 18)evtst = est22vst2(st , jt , t)bh(t)=2st2th2vtst2+ot .
from the assumption ( iii ) , we have e(t ) = rtt .
thus
( 19)rvttstt=vtt+h2st2t2h12vtst2t + vtjtjt2st2th2vtst2 .
consequently
( 20)vtt+h2st2t2h12vtst22st2th12vtst2 + rstvtstrvt=0 .
the above equation can be simplified as
( 21)vtt+12~2st22vtst2+rstvtstrvt=0 .
here
( 22)leh=2th1,~2=22ht2h1lehsign(vss ) .
the boundary condition is
( 23)vtjtst = jt=0 ,
whose financial significance is that the value of option is not sensitive to the maximum when the underlying asset price reaches the maximum .
according to the definition of the lookback put option with floating strike price , the formula can be given as
( 24)v(st , jt , t)=jtst .
for the option purchaser , a hedging portfolio t is constructed : one long position of lookback put option and short t shares of stock ; then the value of the portfolio at the current time t is t = vt tst .
assume that the trade occurs only at times t and t + t where t denotes the hedging time interval .
then over a small time interval t , the change in value of the portfolio will be
( 7)t=vttstvtst .
the stochastic partial differential equation ( 3 ) can be shown as
( 8)st = rstt+stbh(t ) .
by using discrete form of lemma 2
, we can get
( 9)vt=vtt+rstvtst+h2t2h1st22vtst2t + stvtstbht+vtjtjt .
substituting ( 9 ) into ( 7 ) yields
( 10)t=vtt+h2st2t2h12vtst2t+vtsttst + vtjtjtvtst .
in order to eliminate risk ,
so in the same interval t , the traded shares of stock are
( 11)vt=vst(st+t , jt+t , t+t)vst(st , jt , t)2vst2(st , jt , t)stbh(t)+2vtstjtjt .
since jt is not differentiable , we need to approximate it as
( 12)jnt=1t0tsnd1/n , 0t ;
then
( 13)njnn1tdjndt = stnjnntt , limn jnt = max0t s=jt .
we use jn(t ) instead of path dependence variable jt ; since st jt , we can get
( 14)st / jnn1stjnnt0 n.
consequently , from ( 11)(15)vt2vst2(st , jt , t)stbh(t ) .
the transaction costs is as follows :
( 16)vtst=2vst2(st , jt , t)st2bh(t)=st22vst2(st , jt , t)bh(t ) .
according to the definition 1 , we know that
( 17)bht = bht+tbht~n0,t2h .
therefore
( 18)evtst = est22vst2(st , jt , t)bh(t)=2st2th2vtst2+ot .
from the assumption ( iii ) , we have e(t ) = rtt .
thus
( 19)rvttstt=vtt+h2st2t2h12vtst2t + vtjtjt2st2th2vtst2 .
consequently
( 20)vtt+h2st2t2h12vtst22st2th12vtst2 + rstvtstrvt=0 .
the boundary condition is
( 23)vtjtst = jt=0 ,
whose financial significance is that the value of option is not sensitive to the maximum when the underlying asset price reaches the maximum .
according to the definition of the lookback put option with floating strike price , the formula can be given as
( 24)v(st , jt , t)=jtst .
hence the result is proved . since the parameter ~ is nonlinear in the model ( 6 ) , it 's difficult to get its analytic solution
firstly we should reduce the three - dimensional nonlinear mathematical model ( 6 ) into a corresponding two - dimensional model so that it can be solved more easily .
let
( 25)x = lnjtst , vst , jt , t = stux, , =tt ;
consequently
( 26)u+r+12^2ux12^22ux2=0,hhhhhhhh0<x< , 0t , ux,=0=ex1 , 0x< , uxx=0=0 , 0t ,
where
( 27)^2=22ht2h1lehsign(uxxux ) .
then the crank - nicolson scheme will be constructed for the nonlinear problem ( 26 ) .
consider the problem to a finite domain = [ 0 , xmax][0 , t ] .
discrete it using the following method and construct a group of grid points ( x , ) = ( xi , n ) .
let
( 28)ui , n = uxi,n , xi = ih , tn = nk , hhhli=0,1,2,
time derivatives and spatial derivatives are , respectively , approximated by difference method
( 29)u(xi,n)uin+1uink,ux(xi,n)12ui+1nui1n2h+ui+1n+1ui1n+12h,2ux2(xi,n ) 12ui+1n2uin+ui1nh2+ui+1n+12uin+1+ui1n+1h2 .
substituting the above equations into the model ( 26 ) gives standard crank - nicolson scheme .
since the corrected volatility ( 27 ) has first- and second - order derivatives , its solution can be obtained through nonlinear iteration .
hence we get the new numerical scheme as follows :
( 30)uin+1uink 121,inui+1n2uin+ui1nh2+ui+1n+12uin+1+ui1n+1h2 + 122,inui+1nui1n2h+ui+1n+1ui1n+12h=0,(31)1,in=22htn2h1lehsigninin,2,in = r+1,in ,
with
( 32)in = ui+1n2uin+ui1nh2 , in = ui+1nui1n2h .
so the numerical scheme equals
( 33)ainui+1n+1+binuin+1+cinui1n+1=inui+1n+inuin+inui1n , hhhhhhhhhhhhhhhhhhhhhhhhli=1,2, ,m1 ,
where
( 34)in = k2h21,ink4h2,in,in=1kh21,in,in = k2h21,in+k4h2,in , ain=k2h21,in+k4h2,in , bin=1+kh21,in , cin=k2h21,ink4h2,in .
the format ( 33 ) is a six - point implicit scheme , whose local truncation error is o(h + k ) .
we define a vector u = [ u1 , u2 , , um1 ] . then the format ( 33 )
can be given as below :
( 35)a(n)un+1=b(n)un+pn , n=0,1,2, ,n1 .
here
( 36)an = b1na1n000c2nb2na2n000c3nb3na3n000cm2nbm2nam2n000cm1nbm1n , bn=1na1n0002n2na2n0003n3na3n000m2nm2nm2n000m1nm1n , pn=1nu0nc1nu0n+1,0, 0,m1numnam1numn+1 t
.
we also need to know the value of the boundary points um and u0 .
when the price of underlying asset st reaches 0 , the lookback put option must be exercised .
according to variable substitution ( 25 ) , we have
( 39)umn = er.
substituting the boundary conditions ( 37 ) and ( 39 ) into ( 35 ) and using chasing method gives this format 's solution .
it can be seen that it does not contain the variable jt in the new numerical scheme so that it avoids the difficulty of determining the variable jt in the iterative process .
in this section , we will firstly study the convergence of the numerical scheme to explain its validity and discuss the influence of various parameters on the lookback option 's value . for simplicity
, we will only consider valuation of lookback put option for h ( 0.5,1 ) .
example 1 . consider a european put option in half a year when the underlying asset is a stock , whose price follows fractional brown motion ( 3 ) , and the option value is satisfied by the model ( 6 ) .
suppose that the stock price is $ 30 , the volatility is 20% per annum , the risk - free interest rate is 5% , the hurst parameter is 0.6 , the hedging time interval is 0.005 , and the number of time steps is taken as 100 , spatial steps taken as 300 in the numerical scheme ( 35 ) . with our usual notation , this means that
( 40)t=0.5 , r=0.05 , =0.2,st=30 , h=0.6 , t=0.005,m=300 , n=100.for different values of hurst parameter , table 1 shows the price for lookback put option with transaction cost through crank - nicolson numerical approach and proves its convergence of this method . from table 1
, we can also see that , with the increase of hurst parameter , the magnitude of decrease for lookback put option value is increasing .
this implies the self - similarity of fbm model for h ( 0.5,1).then we study the influence of transaction cost rates on lookback put option value .
figure 1 displays that the value of the option is decreasing with the increase of transaction costs .
this is mainly because in this paper , for the long position of options , we only consider the purchase price .
transaction rates ' increase makes a unit of an asset 's cost increase , directly leading to the option hedging costs ' raising .
so option value will decrease . besides , with the initial stock price increased , the lookback put option value increases .
figure 2 shows the effect of expiration time tand stock price st on lookback put option value . from it
this is mainly because that the option value increases over time.then we discuss the impact of risk - free rate and volatility change on lookback put option value . from figure 3
, it can be seen that the option value decreases with risk - free rate increasing .
one factor is that the expected rate of return rises as risk - free rate grows .
another factor is that risk - free rate 's growth leads to the present value of future cash flows dropping . on the other hand , the larger the volatility , the larger the option value .
it is mainly because that volatility 's increase amplifies the probability of making large gains in the future.finally , we illustrate the advantages of the model in this paper from the data in financial market . taking china guodian warrants for example , we will use the new model presented in this paper and black - scholes model to reprice the warrants and obtain the error between theoretical and empirical price to reflect the rationality of the model proposed .
china guodian warrants was listed on may 22 , 2008 , and exercised on may 21 , 2010 , with the strike price 7.47 yuan and the right ratio 1.00 . from the historical data of the stock price for china guodian power ( 600795 ) during the time interval from march 18 , 1997 , to november 1 , 2009 , it can be estimated that the volatility = 0.5937 .
assume that interest rate r = 2% and transaction cost rate = 0.001 .
table 2 below shows the statistical characteristics of the logarithmic rate of return for china guodian warrants .
it can be observed that the value of kurtosis for the warrants is greater than that for the standard normal distribution and the probability to obtain corresponding statistic j - b is less than 0.05 , which indicates share earnings is distributed the feature aiguille large remaining part.by comparison between theoretical and empirical prices , figure 4 shows pricing errors under the pricing model of lookback option with transaction costs based on fractional brownian motion process ( h = 0.7 ) and black - scholes model , respectively . as can be seen from figure 4 , the pricing errors under fbm model are significantly less than bs model .
consider a european put option in half a year when the underlying asset is a stock , whose price follows fractional brown motion ( 3 ) , and the option value is satisfied by the model ( 6 ) .
suppose that the stock price is $ 30 , the volatility is 20% per annum , the risk - free interest rate is 5% , the hurst parameter is 0.6 , the hedging time interval is 0.005 , and the number of time steps is taken as 100 , spatial steps taken as 300 in the numerical scheme ( 35 ) . with our usual notation
, this means that
( 40)t=0.5 , r=0.05 , =0.2,st=30 , h=0.6 , t=0.005,m=300 , n=100 . for different values of hurst parameter , table 1 shows the price for lookback put option with transaction cost through crank - nicolson numerical approach and proves its convergence of this method . from table 1
, we can also see that , with the increase of hurst parameter , the magnitude of decrease for lookback put option value is increasing .
this implies the self - similarity of fbm model for h ( 0.5,1 ) .
figure 1 displays that the value of the option is decreasing with the increase of transaction costs .
this is mainly because in this paper , for the long position of options , we only consider the purchase price .
transaction rates ' increase makes a unit of an asset 's cost increase , directly leading to the option hedging costs ' raising .
besides , with the initial stock price increased , the lookback put option value increases .
figure 2 shows the effect of expiration time tand stock price st on lookback put option value . from it
then we discuss the impact of risk - free rate and volatility change on lookback put option value . from figure 3
, it can be seen that the option value decreases with risk - free rate increasing .
one factor is that the expected rate of return rises as risk - free rate grows .
another factor is that risk - free rate 's growth leads to the present value of future cash flows dropping . on the other hand , the larger the volatility , the larger the option value .
it is mainly because that volatility 's increase amplifies the probability of making large gains in the future .
finally , we illustrate the advantages of the model in this paper from the data in financial market . taking china guodian warrants for example
, we will use the new model presented in this paper and black - scholes model to reprice the warrants and obtain the error between theoretical and empirical price to reflect the rationality of the model proposed .
china guodian warrants was listed on may 22 , 2008 , and exercised on may 21 , 2010 , with the strike price 7.47 yuan and the right ratio 1.00 . from the historical data of the stock price for china guodian power ( 600795 ) during the time interval from march 18 , 1997 , to november 1 , 2009 , it can be estimated that the volatility = 0.5937 .
assume that interest rate r = 2% and transaction cost rate = 0.001 .
table 2 below shows the statistical characteristics of the logarithmic rate of return for china guodian warrants .
it can be observed that the value of kurtosis for the warrants is greater than that for the standard normal distribution and the probability to obtain corresponding statistic j - b is less than 0.05 , which indicates share earnings is distributed the feature aiguille large remaining part . by comparison between theoretical and empirical prices ,
figure 4 shows pricing errors under the pricing model of lookback option with transaction costs based on fractional brownian motion process ( h = 0.7 ) and black - scholes model , respectively .
as can be seen from figure 4 , the pricing errors under fbm model are significantly less than bs model .
in this paper , the lookback option pricing problem , with proportional transaction costs under the fractional brown motion model , was studied . by using hedging principle , the nonlinear partial differential equations , satisfied by the option value ,
we have constructed the crank - nicolson scheme and verified its effectiveness by using the matlab software .
it can be seen that the model we have built up is more in line with the reality of the market environment through matlab software simulation . | ### Summary:
: the pricing problem of lookback option with a fixed proportion of transaction costs is investigated when the underlying asset price follows a fractional brownian motion process .
firstly , using leland 's hedging method a partial differential equation satisfied by the value of the lookback option is derived .
then we obtain its numerical solution by constructing a crank - nicolson format .
finally , the effectiveness of the proposed form is verified through a numerical example . meanwhile
, the impact of transaction cost rate and volatility on lookback option value is discussed . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: klippel - trenaunay syndrome ( kts ) is characterized by triad of port - wine stain , varicose veins , and bony and soft tissue hypertrophy .
a 45-year - old male presented with an ulcer over the left ankle . on examination , dilated tortuous veins were present all over the left lower limb including gluteal region .
there was associated muscular atrophy of left leg and deformity of left great toe since birth .
cavernous hemangiomas were present on his face , chest , back , gluteal region , groin and legs and were observed mostly on the left side [ figures 13 ] .
he had no family history of similar disorder and had been asymptomatic till he developed ulcer over left ankle 4 months ago .
after initial physical evaluation , investigations were advised . a routine hematology revealed normal results .
doppler study revealed incompetence of venous valves at all level in the left lower limb .
there was no evidence of arterio - venous fistula or deep venous thrombosis . however , the arteries showed atherosclerotic changes , with sub - cutaneous edema all over the left lower limb .
abdominal and pelvic ultrasound revealed subcutaneous soft tissue swellings in the inguinal and gluteal region and abnormally enlarged urinary bladder . computerized tomographic scan of the chest and abdomen revealed paravertebral soft - tissue attenuated masses from d1 to d10 [ figure 4 ] .
port wine stain involving face , chest , both upper limbs atrophy of muscles of left leg with deformity of great toe varicosity of veins over buttock and lateral aspect of thigh computer tomography lower chest showing paravertebral soft tissue mass
about a century ago , two french physicians maurice klippel and paul trenaunay described two patients with hemangiomatous lesions of the skin associated with asymmetric soft tissue and bone hypertrophy , and coined the term naevus variqueux osteohypertrophique . years later , frederick parks weber noted the occurrence of these findings in association with arteriovenous fistulas .
the related klippel - trenaunay - weber syndrome describes those individuals who have an arteriovenous malformation as a component of their syndrome .
the classic clinical triad includes capillary malformations ( port wine stain ) , a usually longer and larger extremity because of soft tissue and bone hypertrophy , and atypical mostly lateral superficial varicosity .
patients with at least two of the three cardinal features have been classified as having an incomplete form of kts .
lesions are usually present since birth and in approximately 75% of patients they appear before 10 years of age .
the origin of this syndrome continues to be investigated , and many theories were discussed .
later studies conducted by happle suggest that the inheritance of a single abnormal gene could explain the development of this syndrome , as well as the occurrence of sporadic and familial cases .
although kts is a sporadic condition , studies report familial cases of kts that have not been inherited in a mendelian pattern , suggesting a multifactorial inheritance .
kts was initially described in 1900 as a triad of cutaneous capillary hemangiomas , bony and soft - tissue hypertrophy , and varicosity of veins .
most patients often show these three components of the clinical syndrome , and hemangioma is often the first to appear .
port - wine stain or flat hemangioma is a vascular malformation present at birth and that does not show tendency toward involution .
it increases in proportion to the child 's growth and may involve any part of the body , although face and cervical region are the most commonly affected areas .
hemangiomas may be limited or extend to deeper areas of skin , including bones , muscles , and organs , worsening the prognosis of the disease .
varicose veins observed in patients with the syndrome may be noticed in early infancy , but they generally become prominent at a later stage and progress until adolescence .
these are large lateral veins that start on the foot or leg proximally and extend upto the gluteal region .
these areas may remain stable or enlarge gradually , causing pain , lymphedema , thrombophlebitis , and ulcers .
hypertrophy is the third symptom to appear in the syndrome and it can be secondary to increase in length of bones and/or increase in circumference due to soft - tissue involvement . it can be observed at birth and progresses during the first year of life . in adolescence ,
vascular malformations involving the gastrointestinal and genitourinary tracts have been reported and can be a significant source of morbidity and even mortality .
patients with vascular malformations of the bladder frequently have associated rectosigmoid or other pelvic organ involvement .
rectal and bladder hemorrhage are serious complications of pelvic vascular malformations and have been reported in 1% of cases .
involvement of the gastrointestinal tract may be more common in kts than previously believed ( occurring in perhaps as many as 20% of patients ) and may go unrecognized in patients without overt symptoms .
therapeutic objectives seek to improve the patient 's condition and treat the consequences of severe lesions .
treatment of port - wine stains is usually done with pulsed dye laser therapy that yields better results when applied to lesions in the face and trunk , as compared to extremities .
the use of orthopedic braces is a good option to prevent the development of vertebral deformities in case of hypertrophy of the lower limbs . with time
, corrective bone surgery may be necessary to treat significant limb length discrepancy , if present .
the hypertrophy involves the length as well as the circumference of the involved extremity and is caused by local hyperemia and venous stasis secondary to the vascular anomaly .
however , in the present case we observed that capillary malformations were extensively present involving both halves of the body , with obvious hypotrophy of left lower limb .
however , in this it may be attributed to regional fatty atrophy and atherosclerosis of vessels .
soft - tissue mass was present subcutaneously and in paravertebral area and urinary bladder was abnormally large and highly placed , probably due to neurofibromatosis . | ### Summary:
: the klippel - trenaunay syndrome ( kts ) is a congenital disorder characterized by capillary malformation , varicosities and bony and soft tissue hypertrophy .
this disease has several morbidities like bleeding , deep venous thrombosis , embolic complications and in some cases enlargement of limb that may require amputation .
vascular malformations are segmented and never cross midline . however , we came across a case , a 45-year - old male , who presented with varicosity of veins and deformity of left lower limb besides cavernous hemangiomas ( port - wine stains ) scattered all over his face , chest , back , gluteal region , groin and legs since birth .
multiple paravertebral soft tissue masses and bladder hypertrophy were also noted due to involving neurofibromatosis
. simultaneous occurrence of kts and neurofibromatosis is rarely seen in clinical practice . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: transition to clerkship is a very challenging movement , with which , many students have experienced struggles .
although numerous initiatives have attempted to mitigate these challenges and to improve clinical learning , most of them have benefited less than expected .
few studies on preparing the students for clerkship are backed up with theories and support activities in real clinical settings . however , workplace learning has been suggested for a less stressful transition and improving clinical learning . through participation in the physical , social , and cultural activities of a workplace
, students practice more on procedural tasks , experience real - patient encounters , and more patient care practices . according to godfrooij et al .
time spent on activities involving direct patient contact is positively related to students perceptions of the quality of their learning environment .
however , in almost all of transitional curricula , courses are designed for short clinical encounters .
although such transitional courses , according to obrien et al . , should include practices using clinical skills in real - patient care settings , time restriction still is a major struggle .
the students stressful feelings at the beginning of internship were rooted in lack of sufficient practical training through real - patient encounter and procedural practices in a sufficient time period .
the aim of this study is to assess the merit and worth of the mentioned transitional clinical curriculum , with courses more prolonged than what is found in similar initiatives .
our medical curriculum at isfahan university of medical sciences consists of four major phases as follows : the first 2 years and a half as basic sciences , one year for introduction to clinical medicine including physiopathology courses , 2 years for clinical exposure , named as
clinical clerkship , and finally 18 months , known as internship for delegating the patient 's responsibility . dividing clinical clerkship phase into two parts , primary and advanced - clinical clerkship , the curriculum decision makers decided to introduce a change in the second part in order for preparing the students for a less challenging internship . in advanced clerkship , students will have more practice on clinical skills , especially in out - patient and emergency settings , mostly on real patients under close supervision .
advanced - clerk students should spend a few nights on call , as spare time , to fulfill more hands on action .
the first part of the clerkship ( i.e. , primary ) , in which the students should act mostly as observers , was subjected only to minor changes such as the arrangement and credit hours of the courses .
our medical curriculum at isfahan university of medical sciences consists of four major phases as follows : the first 2 years and a half as basic sciences , one year for introduction to clinical medicine including physiopathology courses , 2 years for clinical exposure , named as
clinical clerkship , and finally 18 months , known as internship for delegating the patient 's responsibility . dividing clinical clerkship phase into two parts , primary and advanced - clinical clerkship , the curriculum decision makers decided to introduce a change in the second part in order for preparing the students for a less challenging internship . in advanced clerkship , students will have more practice on clinical skills , especially in out - patient and emergency settings , mostly on real patients under close supervision .
advanced - clerk students should spend a few nights on call , as spare time , to fulfill more hands on action .
the first part of the clerkship ( i.e. , primary ) , in which the students should act mostly as observers , was subjected only to minor changes such as the arrangement and credit hours of the courses .
following the approval by education councils at both levels of school and university , the new clerkship program was launched on april 1 2009 , and education development office at school of medicine was assigned to conduct its formative evaluation . through several focus group discussions with various stakeholders
( e.g. , academic staff , residents , nurses , representatives of clerkship students , and executive managers ) , we clarified the key points we must have initiated our efforts from .
first , we defined the competences and procedural skills on which the students should be trained .
so attending at regular meetings of each clinical department , we determined what , where , when , and by whom , major clinical competences should be taught , as well as their appropriate evaluation methods .
all of the topics were included in study guide booklets and delivered at the beginning of each course .
the course logbooks also were included in booklets . after describing the course and the booklet itself , we determined expected skills achievement , as well as real - patient encounters required for students during the morning clinical rounds and night shifts .
we asked students to fill out the blank forms right after facing with each case in any setting ( clinical wards , out - patient clinics , operating room , and emergency department ) .
we gathered and analyzed logbooks from departments of neurology , orthopedics , anesthesiology and toxicology , infectious diseases , internal medicine , and pediatrics . the analysis consisted of calculating the number of students patient contacts , procedural skills practiced during the day and night shifts , and
we also delivered the dundee ready education environment measure ( dreem ) questionnaires at the end of each course for assessing the students perceptions about their learning process .
data from dreem were analyzed according to its original guide key , in all five sub - scales including students : perception of learning , perception of course organizers , academic self - perception , perception of atmosphere , and social self - perception .
two departments ( internal medicine and pediatrics ) did not provide us with useful logbooks ; however , we selected and analyzed 30 sufficiently filled logbooks for each of the remainders . of expected patient contacts at four departments ,
totally , 64% were met , with highest rate ( 100% ) in anesthesiology and toxicology and lowest one ( 32% ) in infectious diseases .
however , the departments acted differently regarding instruction of the procedural skills in day time and/or night shifts . in neurology department , all of the required skills were taught in day time .
other departments were not in good status in the case of teaching in day time . on the other hand , in night shifts ,
the neurology and anesthesiology and toxicology departments had taught approximately all of the planned procedural skills .
orthopedics was the lowest successful department in both day time and night shift procedural skills training .
besides frequent meetings with advanced - clerk students revealed a feeling of futility about night shifts in almost all of the departments .
residents in neurology had the most commitment for contribution to training the clerkship students , whereas residents in other departments did not care enough to such roles .
for example , many blank logbooks were signed and sealed ; also we found a considerable number of filled logbooks without any seal or signature of residents .
dreem score ( 140/200 ) was given to anesthesiology and toxicology department and the lowest one ( 97/200 ) to department of infectious diseases .
of all five sub - scales , the fourth one ( i.e. , students perception of atmosphere ) was at the highest level [ table 1 ] , with the mean score of 32.33/48 , whereas
students social self - perception ( 5 sub - scale ) was at the lowest level .
in the domain of students perception of learning , two departments ( i.e. , internal medicine and infectious diseases ) had been scored as low as 21/48 and 18/48 , respectively , it means in both departments teaching is viewed negatively .
total mean score in this sub - scale was 24.83/48 which is interpreted the same .
however , regarding the total mean score of the whole dreem scale , ( 114.83 ) more positive than negative feeling was there in clinical educational environment in six evaluated departments .
we measured the number of students patient encounters , and procedural skills practiced during each clinical course .
however , initially , we defined the learning objectives through consultation with academic staff , while in an american national survey , the researchers found that less than one - third of the internal medicine sub - internship programs had explicit goals and objectives for their students .
since studies show that real - patient contact makes clinical knowledge more durable ; according to our findings , nearly two - third of patient encounters planned for our students were met .
so , acquisition of a longstanding knowledge is expected for our advanced - clerkship students .
nevertheless , students perception of learning yet , suggests a problem existing in delivery of the program content .
given the fact that developing clinical skills creates confidence and motivation in students , and since more than 71% of clinical skills in the above - mentioned departments were taught , it is expected that our students are well confident and motivated ; and this is confirmed by their
although it is believed for night shifts to be an irreplaceable part of medical education , and more than half of american sub - internship students had three to nine night calls during their rotations , however , it was one of the most problematic issues found in our study . therefore , it is highly recommended to promote the learning status of this inherently useful section of advanced - clerkship program .
the last finding in our study on logbooks was the residents low contribution to instructing the students .
although learning experiences for sub - interns , provided by resident covered ward service ( rcws ) were dramatically better than resident uncovered hospitalist service ( ruhs ) , time constrain along with lack of support from attending doctors has been reported as the major conflicts for residents to fulfill this expectation .
nevertheless , some studies say attending doctors believe that teaching competences should be incorporated in residency programs .
we can claim that the program has some merits , as some departments were successful in clinical training of the advanced - clerkship students .
our findings ensure the program decision makers to continue with the program . however , some improvements are highly needed , especially in residents supervision on students learning activities , the clinical teaching of attending doctors , and enriching the night shifts .
it is also recommended to conduct a comparative study with other institutions utilizing traditional clerkship curriculum .
since logbooks were developed at departments , they were tremendously different in some features , and this made them difficult to be uniformly analyzed .
lack of formal documents from similar studies on traditional curriculum made it difficult to have a rigorous judgment about improvement of clinical clerkship program . | ### Summary:
: background : in a formative evaluation , we were supposed to find whether an innovative program has some merits to be continued or not .
we also determined the critical points of the program .
the evaluated program was a clinical pre - clerkship curriculum launched for departing to a less stressful medical clerkship.materials and methods : we analyzed the information contained in the students logbooks . using dundee ready education environment measure standardized questionnaire
, we also assessed the students perception of learning environment within six clinical departments.results:totally , 64% of expected patient contacts , and teaching of more than 71% of required skills at 4 departments were carried out and students had more positive than negative perspective of their learning environments.conclusion:the evaluand is a worthwhile program to be continued , though it needs some considerations for improvement . |
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: right heart thrombi are usually found in hemodynamically compromised patients with acute pe and indicate worse prognosis . in patients with high - risk pe and right heart dysfunction pulmonary embolectomy is a treatment option .
an autopsy - based study on pulmonary thromboembolus morphology suggested its structure to be layered , with layers of fibrin and platelets alternating with layers of erythrocytes .
fibrin network , that represents a major component of venous thrombi , is lysed at a rate dependent on its architecture , with impaired lysis in case of dense clots .
fibrin clots obtained from subjects with chronic thromboembolic pulmonary hypertension have been reported to be resistant to lysis . in vitro experiments
indicate that velocity of flow markedly affects fibrin clot structure . with the increase of flow ,
more fibrin fibers are aligned along the flow vector , and less are randomly oriented .
recently , we have shown that the structure of the pulmonary thrombus obtained during embolectomy is organized , fibrin - rich , and not layered . to our knowledge , there is no ex vivo data on the architecture of right heart thrombi and pulmonary thromboemboli . here
we present the case of a 56-year - old woman with high - risk pe whose thrombotic material removed from right atrium and lobar and segmental pulmonary arteries has been studied using scanning electron microscopy ( sem ) .
a 56-year - old woman ( body mass index , 29.8 kg / m ) , a former smoker , with a history of chronic venous insufficiency who suffered from recent - onset schizophrenia was admitted to our institution for pe after a 48 h treatment with unfractionated heparin in a regional hospital .
two months prior to admission she was hospitalized in a psychiatric ward and received no thromboprophylaxis . on admission , the patient presented with progressing dyspnea , cyanosis and chest discomfort with elevated d - dimer ( > 16,000 g / l ) .
contrast - enhanced computed tomography revealed large emboli at the right pulmonary artery ( pa ) trifurcation and in the left pa ( fig .
transthoracic echocardiogram demonstrated right ventricular ( rv ) overload with rv systolic pressure exceeding 50 mmhg , and a right atrial mass originating in the inferior vena cava . within 2
due to rapid clinical deterioration despite anticoagulant therapy , she underwent urgent embolectomy with extracorporeal circulation in deep hypothermia .
pulmonary trunk was opened , and fresh and organized thrombi were removed from right and left lobar and segmental branches .
after opening of the right atrium , a 7 cm long fresh thrombus coming from the inferior vena cava was removed .
the patient required prolonged ventilatory support and management of pulmonary hypertension during the post - operative period .
contrast - enhanced computed tomography showing a thrombus at the trifurcation of right pulmonary artery ( a ) .
representative sem images of the removed parts of the thrombus from the right atrium ( b and e ) , lobar pulmonary artery ( c and f ) and segmental artery ( d and g ) .
d magnification , 1,000 ; e g magnification , 3,500 . scale bar 5 m computed tomography and scanning electron microscopic ( sem ) images .
contrast - enhanced computed tomography showing a thrombus at the trifurcation of right pulmonary artery ( a ) .
representative sem images of the removed parts of the thrombus from the right atrium ( b and e ) , lobar pulmonary artery ( c and f ) and segmental artery ( d and g ) .
b d magnification , 1,000 ; e g magnification , 3,500 . scale bar 5 m the thromboemboli were evaluated using sem , as previously described .
after washing , the thrombus was fixed with 2.5 % glutaraldehyde phosphate buffered saline solution .
specimens were dehydrated , gold coated , and photographed digitally with a jeol jsm 5410 ( jeol , tokyo , japan ) .
the microscopic analysis revealed that the atrial thrombus was mainly composed of erythrocytes with few platelet aggregates , and some white cells ( fig .
the fibrin network of the atrial thrombus was rather randomly arranged . in the thrombi removed from lobar ( fig .
1d , g ) , a stepwise increase in relatively dense fibrin and platelet aggregates was observed .
there was a noticeable decrease in the count of erythrocytes and increase in the count of white cells in the thrombotic material removed from lobar and segmental arteries , as compared with the atrial thrombus ( fig . 1 ) .
thrombi removed from lobar and segmental arteries were characterized by fibrin fibers alignment along the longitudinal axis of the respective vessel , which was absent in the atrial thrombus .
to our knowledge , this study is the first to demonstrate the composition of right atrial and pulmonary thrombi removed during embolectomy in the pe patient .
we observed that the fibrin content in pulmonary thrombus increases when the diameter of pulmonary arteries reduces , which is in contrast to the major impact of the time since symptom onset ( the clot s ageing ) , but not the vessel caliber , reported in acute myocardial infarction .
moreover , the thrombus location appears to affect the architecture of fibrin network , since more tightly packed fibrin fibers resembling a solid mass were observed in thrombi from pulmonary arteries where the flow velocity is higher than in the right atrium .
it is likely that the structural differences among the various thrombi , observed by us , result in part from hemodynamic conditions in the right atrium versus pulmonary arteries .
higher flow velocity in the pulmonary arteries might also contribute to lower number of erythrocytes , accompanied by increased fibrin content in the thrombi from those vessels .
the increasing number of white cells within distal pulmonary thrombi indicates their early active role in their modulation and/or degradation in vivo .
interestingly , fibrin fiber alignment in distal pulmonary thrombi shown in this report confirms the recent in vitro findings , clearly indicating a potent modulatory effect of flow on fibrin structure in vivo .
it should also be highlighted that in pulmonary thrombi , platelets and fibrin are co - localized , and the presence of platelets determines the local formation of denser fibrin network via multiple mechanisms , including unfavorable impact of polyphosphate and platelet factor 4 on clot structure , reported in vitro .
this report provides an important in vivo evidence of the importance of platelet - related factors affecting fibrin clot architecture .
mechanisms underlying such fibrin phenotype in pulmonary thromboemboli obtained from our pe patient remain to be elucidated .
most likely , transient factors , including those linked to hemodynamic abnormalities and massive thrombosis , determine thrombus properties to a greater extent than genetic factors in our case .
we can not exclude that abnormal fibrin clot phenotype measurable prior to pe might contribute to unfavorable clinical course in this case and contribute to failure of heparin therapy .
it might be speculated that unfavorable fibrin network characteristics with formation of compact fibrin structures in some patients with acute pe might explain , at least in part , heparin treatment failure . | ### Summary:
: pulmonary embolectomy is a treatment option in selected patients with high - risk pulmonary embolism ( pe ) .
efficiency of thrombus degradation in pe largely depends on the architecture of its fibrin network , however little is known about its determinants .
we present the case of a 56-year - old woman with high - risk pe and proximal deep - vein thrombosis , whose thrombotic material removed during embolectomy from the right atrium and pulmonary ( lobar and segmental ) arteries has been studied using scanning electron microscopy ( sem ) .
sem images showed that distally located thrombi are richer in densely - packed fibrin fibers and contain more white cells and less erythrocytes than the proximal ones and the atrial thrombus .
fibrin fibers alignment along the flow vector was observed in the thrombi removed from high - velocity flow pulmonary arteries , and not in the atrial thrombus .
the content of denser fibrin network and platelet aggregates was increased in segmental thromboemboli .
our findings describe the relation between thrombus architecture and location , and might help to elucidate thrombus resistance to anticoagulant therapy in some pe patients . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: we adopted a review of reviews approach as proposed by the health development agency ( hda ) : given the increasing number of systematic reviews of interventions in ophthalmology literature , the goal of this systematic review of reviews is to collate the evidence and appraise the quality of evidence from published reviews on intravitreal bevacizumab for neovascular amd .
we searched the literature for published systematic reviews ( and meta - analyses ) of observational and experimental studies whose primary purpose was to ascertain the effectiveness of intravitreal bevacizumab for neovascular amd .
reviews which looked at patients with neo - vascular amd regardless of the stage / severity of disease or with subfoveal choroidal neovascularization ( cnv ) secondary to neovascular amd were included .
the intervention of interest in the review was intravitreal bevacizumab compared against photodynamic therapy ( pdt ) with verterporfin , pegaptanib or ranibizumab .
reviews which were not labeled as systematic but included an explicit statement of search methods , inclusion , exclusion , data synthesis were included as well .
the primary outcome of interest for the review was improvements in visual acuity ( va ) measured by snellen or etdrs charts and decrease in central retinal thickness ( crt ) .
all types of primary studies ( observational and experimental ) were excluded ; similarly reviews which depended upon previous systematic reviews for their primary data were excluded .
we searched the literature for published systematic reviews ( and meta - analyses ) of observational and experimental studies whose primary purpose was to ascertain the effectiveness of intravitreal bevacizumab for neovascular amd .
reviews which looked at patients with neo - vascular amd regardless of the stage / severity of disease or with subfoveal choroidal neovascularization ( cnv ) secondary to neovascular amd were included .
the intervention of interest in the review was intravitreal bevacizumab compared against photodynamic therapy ( pdt ) with verterporfin , pegaptanib or ranibizumab .
reviews which were not labeled as systematic but included an explicit statement of search methods , inclusion , exclusion , data synthesis were included as well .
the primary outcome of interest for the review was improvements in visual acuity ( va ) measured by snellen or etdrs charts and decrease in central retinal thickness ( crt ) .
all types of primary studies ( observational and experimental ) were excluded ; similarly reviews which depended upon previous systematic reviews for their primary data were excluded .
we conducted searches in three databases medline ( via pubmed ) , embase , cochrane library and centre for reviews and dissemination ( crd ) databases for systematic reviews published between 2000 and 2013 .
macula * or amd or armd or intra ( - ) vitreous or intra - vitreal in any field , and for the intervention the search terms are bevacizumab or avastin in any field .
the following mesh terms were also searched in combination with the above free text keywords , ( ( intravitreal injections[mesh ] or injections , intravenous[mesh ] ) and bevacizumab[substance name ] ) and wet macular degeneration[mesh ] and ( humans[mesh terms ] and ( meta - analysis[ptyp ] or review[ptyp ] ) ) .
search for unpublished systematic reviews included searches conducted in proquest dissertations and thesis , conference proceedings and mednar . titles and abstracts of identified reviews were examined independently by 2 reviewers to assess each review for inclusion using joanna briggs institute ( jbi ) study eligibility form ( appendix i ) .
data from eligible reviews was extracted using the jbi data extraction form ( appendix ii ) .
the quality of the systematic reviews was assessed using jbi critical appraisal checklist ( appendix iii ) for systematic reviews which looks at 10 critical aspects of the systematic review .
scores were given for adherence to each of those aspects , a minimum score of 1 and a maximum score of 10 would signify a well conducted sr .
decisions regarding study eligibility and quality were made by two reviewers , any disagreements were resolved by discussion .
information on primary studies was extracted from the reviews ; in the case where reviews reported discrepant study findings , the primary studies were consulted .
information on the reviewers assessment of the evidence , design and findings of relevant primary studies were extracted from each review .
the level of evidence in support of ( or discounting ) the effect of an intervention was classified as :
these were derived using a framework [ table 1 ] based on the quality of the reviews , the reviewers conclusions and the designs / findings of the primary studies included in the reviews . in the absence of controlled trials , longitudinal cohort and case control designs ( involving incident cases ) were considered to be more robust , whereas ecological , serial cross - sectional and cross - sectional designs were considered to be
weaker. types of evidence statement and the level of evidence that was required to support each statement
titles and abstracts of identified reviews were examined independently by 2 reviewers to assess each review for inclusion using joanna briggs institute ( jbi ) study eligibility form ( appendix i ) .
data from eligible reviews was extracted using the jbi data extraction form ( appendix ii ) .
the quality of the systematic reviews was assessed using jbi critical appraisal checklist ( appendix iii ) for systematic reviews which looks at 10 critical aspects of the systematic review .
scores were given for adherence to each of those aspects , a minimum score of 1 and a maximum score of 10 would signify a well conducted sr .
decisions regarding study eligibility and quality were made by two reviewers , any disagreements were resolved by discussion .
information on primary studies was extracted from the reviews ; in the case where reviews reported discrepant study findings , the primary studies were consulted .
information on the reviewers assessment of the evidence , design and findings of relevant primary studies were extracted from each review .
the level of evidence in support of ( or discounting ) the effect of an intervention was classified as :
these were derived using a framework [ table 1 ] based on the quality of the reviews , the reviewers conclusions and the designs / findings of the primary studies included in the reviews . in the absence of controlled trials , longitudinal cohort and case control designs ( involving incident cases ) were considered to be more
robust , whereas ecological , serial cross - sectional and cross - sectional designs were considered to be
weaker. types of evidence statement and the level of evidence that was required to support each statement
nine relevant reviews were identified from over 30 citations , of which 5 reviews fulfilled the review 's inclusion criteria .
the following were the reasons for excluding 4 reviews : studies primarily looked at the safety of bevacizumab without focusing on its effectiveness ( 2 ) , the major criteria for quality appraisal were not satisfactorily fulfilled ( 2 ) , ( search sources inadequate , criteria for critical appraisal inappropriate , critical appraisal not done independently , data extraction not independently done , methods used for combining studies were inappropriate ) .
jbi critical appraisal quality score and summary of conclusions of the retrieved reviews the 5 included reviews were published between 2009 and 2012 ; they summarized 126 publications ( after excluding duplicate publications ) on intravitreal bevacizumab for neovascular age related macular degeneration .
19% of these publications were prospective studies and 10% of these were randomized controlled trials ( rcts ) and the rest had designs with no control group which includes case series and before - after studies .
the review question was clearly stated in all included reviews either in the title , abstract or in text .
the average quality score of the reviews was 7 ( 95% confidence interval 6.2 to 7.8 ) ; maximum possible quality score is 10 [ table 3 ] .
three - fifth of the reviews had a quality score of 7 or lower , these reviews had some methodological limitations .
criteria for appraisal were appropriate and independent appraisal was conducted in most of the reviews .
methods used to minimize error in data extraction were not specified in most of the reviews [ table 4 ] .
data were tabulated as narrative summaries due to the heterogeneity of the design and the findings [ table 5 ] .
quality score of jbi critical appraisal checklist by 2 independent reviewers validity assessments with jbi critical appraisal check list after adjudication selected reviews published on intravitreal bevacizumab and age - related macular degeneration by outcome and year published all 5 reviews showed bevacizumab to be effective for neovascular amd in the short - term when used alone or in combination with pdt or pegaptanib .
the sr by jsag schouten which was of good quality [ table 2 ] showed improvements in visual acuity and decrease in central retinal thickness in patients with exudate amd after bevacizumab [ table 3 ] .
rct 's showed that intravitreal bevacizumab was more effective than pdt with a mean change in visual acuity ( va ) of + 12.8 etdrs letters ( range + 11 to + 14 ) and weighted mean change for crt of 129m ( range 100 to 202 ) . the before - after studies of bevacizumab showed a mean change in va of + 8.6 letters ( range + 2 to + 26 ) and change in crt was 90 um ( range 46 to 190 ) .
, found off - label use of bevacizumab superior to pdt , in the short term , however the evidence was of moderate quality ( 2b level of evidence ) primarily from before - after studies , case series and rct 's of bevacizumab for neovascular amd .
in their meta - analysis showed that bcva was higher among those treated with bevacizumab than those in the pdt group ( risk ratio , rr , 0.49 ; 95% confidence interval ( ci ) , 0.31 to 0.78 ; p = 0.01 ) .
jyothi et al . , summarized the findings from 5 rct 's and 50 observations studies that met strengthening the reporting of observational studies in epidemiology
the review showed intravitreal bevacizumab led to mean gain in vision at 3 months ( + 7.76 5.4 etdrs letters ( range + 2 to + 14.4 ) ; this effect was maintained at 6 months in studies with longer follow - up .
review by pitlick et al . , summarized findings from 4 rct 's , the review showed that bevacizumab in comparison to verteporfin pdt or pegaptanib to be superior in improving va and reversing vision loss .
bevacizumab when compared to ranibizumab was found to have equivalent efficacy and significantly less expensive .
the 5 included reviews were published between 2009 and 2012 ; they summarized 126 publications ( after excluding duplicate publications ) on intravitreal bevacizumab for neovascular age related macular degeneration .
19% of these publications were prospective studies and 10% of these were randomized controlled trials ( rcts ) and the rest had designs with no control group which includes case series and before - after studies .
the review question was clearly stated in all included reviews either in the title , abstract or in text .
the average quality score of the reviews was 7 ( 95% confidence interval 6.2 to 7.8 ) ; maximum possible quality score is 10 [ table 3 ] .
three - fifth of the reviews had a quality score of 7 or lower , these reviews had some methodological limitations .
criteria for appraisal were appropriate and independent appraisal was conducted in most of the reviews .
methods used to minimize error in data extraction were not specified in most of the reviews [ table 4 ] .
data were tabulated as narrative summaries due to the heterogeneity of the design and the findings [ table 5 ] .
quality score of jbi critical appraisal checklist by 2 independent reviewers validity assessments with jbi critical appraisal check list after adjudication selected reviews published on intravitreal bevacizumab and age - related macular degeneration by outcome and year published all 5 reviews showed bevacizumab to be effective for neovascular amd in the short - term when used alone or in combination with pdt or pegaptanib .
the sr by jsag schouten which was of good quality [ table 2 ] showed improvements in visual acuity and decrease in central retinal thickness in patients with exudate amd after bevacizumab [ table 3 ] .
rct 's showed that intravitreal bevacizumab was more effective than pdt with a mean change in visual acuity ( va ) of + 12.8 etdrs letters ( range + 11 to + 14 ) and weighted mean change for crt of 129m ( range 100 to 202 ) .
the before - after studies of bevacizumab showed a mean change in va of + 8.6 letters ( range + 2 to + 26 ) and change in crt was 90 um ( range 46 to 190 ) . review by ziemssen et al .
, found off - label use of bevacizumab superior to pdt , in the short term , however the evidence was of moderate quality ( 2b level of evidence ) primarily from before - after studies , case series and rct 's of bevacizumab for neovascular amd .
in their meta - analysis showed that bcva was higher among those treated with bevacizumab than those in the pdt group ( risk ratio , rr , 0.49 ; 95% confidence interval ( ci ) , 0.31 to 0.78 ; p = 0.01 ) .
jyothi et al . , summarized the findings from 5 rct 's and 50 observations studies that met strengthening the reporting of observational studies in epidemiology
the review showed intravitreal bevacizumab led to mean gain in vision at 3 months ( + 7.76 5.4 etdrs letters ( range + 2 to + 14.4 ) ; this effect was maintained at 6 months in studies with longer follow - up .
, summarized findings from 4 rct 's , the review showed that bevacizumab in comparison to verteporfin pdt or pegaptanib to be superior in improving va and reversing vision loss .
bevacizumab when compared to ranibizumab was found to have equivalent efficacy and significantly less expensive .
systematic reviews in ophthalmology are increasing at a rapid pace , but little information is available on the quality of these reviews .
this systematic review of reviews appraises the quality of evidence from srs on effectiveness of bevacizumab for neovascular amd .
overall , the published reviews on this topic were of good quality , the reviews used 7 of 10 best practices for an objective and systematic methodology as enumerated by the jbi quality appraisal checklist with an a priori study design .
bias arising from publication has an important influence on the results of systematic reviews and is more difficult to detect and adjust for than other forms of bias .
thus , when searching for studies to include in a systematic review , it is critical that the literature search strategy is explicitly described , comprehensive , and inclusive of both unpublished and published research .
the description of the search strategy provides some assurance that the authors have conducted a comprehensive , detailed , and an exhaustive search for literature relevant to the study question .
the search strategy and sources of studies were found to be appropriate for 40% and 60% of the reviews respectively .
another key feature of the systematic review is to assess bias , to assess the funding sources and financial conflicts of authors as they can influence the outcomes the studies .
industry funded studies are more likely to have results that favor their product , even when controlling for other methodological biases . in our review , only one study had disclosed the conflict of interest , this study also had much methodological weakness and hence was not included . a well - conducted systematic review provides readers with an accurate summary and defensible synthesis of the available evidence .
the inclusion of a methods section is essential for the transparency of results and provides the reader with the means to reproduce the review if need be . in the absence of these basic methodological features , conclusions shown in reviews
may be little more than personal subjective opinions informed by the scientific evidence but not based on strong methodological grounds . in this review of the reviews we found that none of the reviews were rated as a 10 out of 10 for quality
, moreover 1 review had significant flaws , the methods sections of this review was insufficient and therefore difficult to evaluate .
as far as the quality of the systematic review is concerned there is scope for improvement . we recommend that ophthalmology journals should adopt uniform reporting standards for systematic reviews ; this would pave way for high - quality systematic reviews in ophthalmology literature .
the review points to the overwhelming evidence available in support of bevacizumab for amd , intravitreal bevacizumab was associated with a mean gain in visual acuity of 7.76 - 12.8 etdrs letters and mean decrease in crt of 129m after intravitreal bevacizumab .
we do not have other systematic reviews of bevacizumab for neovascular age related macular degeneration with which to compare our conclusions , but they are consistent with the conclusions of 7 of the 9 most recent systematic reviews .
there are some inherent weaknesses in this approach . in general due to resource constraints , we relied on the information in the included reviews .
the quality of the reviews may vary ; the reviews may have done a poor job in specifying their inclusion and exclusion criteria , the searches may not be comprehensive , the review authors may not have assessed or extracted data from the primary studies adequately , nor analyzed and synthesized the findings across the studies properly . but even using high quality reviews , we necessarily lose information and details that we can only find if we go back to the primary studies .
our literature search only covered the three databases and hand searching was not done due to resource constraints .
not withstanding the previously mentioned concerns , to our knowledge , this is the first study which appraises the quality of published systematic reviews on bevacizumab for neovascular amd .
there are some inherent weaknesses in this approach . in general due to resource constraints , we relied on the information in the included reviews .
the quality of the reviews may vary ; the reviews may have done a poor job in specifying their inclusion and exclusion criteria , the searches may not be comprehensive , the review authors may not have assessed or extracted data from the primary studies adequately , nor analyzed and synthesized the findings across the studies properly . but even using high quality reviews , we necessarily lose information and details that we can only find if we go back to the primary studies .
our literature search only covered the three databases and hand searching was not done due to resource constraints .
not withstanding the previously mentioned concerns , to our knowledge , this is the first study which appraises the quality of published systematic reviews on bevacizumab for neovascular amd .
reviews have found bevacizumab to be effective for neovascular amd when used either alone or in combination with alternates such as pdt or pegatanib .
this study also highlights the quality of systematic reviews examining the effectiveness of bevacizumab for neovascular age related macular degeneration , highlighting the methodological shortcomings and the need for uniform reporting of the preferred items for systematic reviews in ophthalmology literature.23 | ### Summary:
: objective : to systematically collate and evaluate the evidence from recent srs of bevacizumab for neo - vascular age related macular degeneration.materials and methods : literature searches were carried out in medline , embase , cochrane databases for all systematic reviews ( srs ) on the effectiveness of bevacizumab for neo - vascular age related macular degeneration , published between 2000 and 2013 .
titles and abstracts were assessed against the inclusion / exclusion criteria using joanna briggs institute ( jbi ) study eligibility form .
data was extracted using the jbi data extraction form .
the quality of the srs was assessed using jbi critical appraisal checklist for srs .
decisions on study eligibility and quality were made by two reviewers ; any disagreements were resolved by discussion.results:nine relevant reviews were identified from 30 citations , of which 5 reviews fulfilled the review 's inclusion criteria .
all 5 reviews showed bevacizumab to be effective for neovascular amd in the short - term when used alone or in combination with pdt or pegaptanib .
the average quality score of the reviews was 7 ; 95% confidence interval 6.2 to 7.8 ( maximum possible quality score is 10 ) .
the selection and publication bias were not addressed in all included reviews .
three - fifth of the reviews had a quality score of 7 or lower , these reviews had some methodological limitations , search strategies were only identified in 2 ( 40% ) reviews , independent study selection and quality assessment of included studies ( 4 ( 80% ) ) were infrequently performed.conclusion:overall , the reviews on the effectiveness of intravitreal / systemic bevacizumab for neovascularage - related macular generation ( amd ) received good jbi quality scores ( mean score = 7.0 points ) , with a few exceptions .
the study also highlights the suboptimal reporting of srs on this topic .
reviews with poor methodology may limit the validity of the reported results ; hence efforts should be made to improve the design , reporting and publication of srs across all journals . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: primary tumors of the heart are rare , and among them , myxoma is the most frequent primary cardiac tumor.1 ) although cardiac myxoma can occur anywhere in the heart , 75% of the myxomas originate in the left atrium , generally in the area of the fossa ovalis.2 ) myxoma originating from the mitral valve is extremely rare . here , we present a case of mitral valve myxoma .
a 62-year - old male patient was admitted to our hospital with the chief complaint of motor aphagia that developed 2 hours previous to his visit . he had a history of traumatic subdural hemorrhage , which occurred 3 years ago , but had no neurological sequelae .
routine laboratory tests showed normal findings except for an elevated c - reactive protein ( crp ) level of 0.92 mg / dl and an elevated erythrocyte sedimentation rate ( esr ) of 36 mm / hr . upon the magnetic resonance imaging of the brain
1 ) . as part of the patient 's workup to find the source of the embolism , transthoracic echocardiography ( tte ) was done .
tte revealed a highly mobile mass at the anterior mitral valve leaflet and trivial mitral regurgitation ( fig .
the patient subsequently underwent transesophageal echocardiography , which also revealed a 1 cm sized mass ( fig . 2c and d ) .
a spherical mass was attached to the mitral valve by a short stalk and was located on the left ventricular ( lv ) side of the mitral valve .
the mass was heterogenous in appearance , which showed central echolucent area , and prolapse of the mass into the lv was observed during diastole . to exclude the diagnosis of infective endocarditis
, 3 pairs of blood cultures were obtained from 3 separate sites which yielded no bacterial growth after five days .
the patient did not have predisposing conditions of infective endocarditis , fever , any immunologic phenomena such as osler 's node , roth ' spot , or glumerulonephritis , and other microbiologic evidence of active infection .
therefore , our case did not fulfill the duke criteria for the clinical diagnosis of infective endocarditis .
the patient underwent sternotomy and cardiopulmonary bypass . during the operation , an 1 1 cm sized pedunculated mass arising at the anterior mitral valve leaflet
the mass was whitish , round , and soft , and it was attached to the mitral valve by a short narrow stalk .
after complete excision of the mass , there was no sign of mitral regurgitation and replacement of the mitral valve was not done . upon histological examination ,
spindle - shaped cells and stellate cells were found in a myxoid stroma , which is consistent with myxoma ( fig .
the patient had an uneventful postoperative course apart from an atrial fibrillation which disappeared after the use of amiodarone .
cardiac myxoma is a rare disease , with an incidence between 0.0017 and 0.03% in autopsy series.3)4 ) myxoma can occur in nearly all age groups but occurs frequently between the third and sixth decades of life.5)6 ) sixty - five percent of cardiac myxoma occurs in women.7 ) about 75% of myxomas originate from the left atrium , 18% in the right atrium , and 4% in the ventricle.8 ) the exact incidence of myxomas originating from the mitral valve is not clear . in one study , it was reported as 1.5% ( 1 case among 68 myxoma cases).9 ) myxoma originating from the heart valve was first reported by jaleski10 ) in 1934 , and the first premortem diagnosis of mitral valve myxoma was reported by sandrasagra et al.11 ) in 1979 . in korea , only 2 cases were reported since 1994.12)13 ) clinical manifestations of myxoma are determined by the location , size , mobility , and friability .
clinical manifestations can be divided into three general categories : systemic symptoms , embolism , and intracardiac obstruction .
systemic symptoms such as general weakness , fever , weight loss , arthralgia , and erythematous rash have been observed , and laboratory abnormalities such as anemia , elevations in crp , esr , and globulin levels have also been reported in patients with myxoma.6)14)15 ) myxoma can cause an embolism by way of the tumor emboli or thromboemboli that are released from or formed on the surface of the tumor . as most myxomas
are located in the left atrium , systemic embolism frequently occurs . in most cases ,
the cerebral arteries are affected , and embolization into the renal , visceral , and coronary arteries has also been reported.8 ) symptoms due to intracardiac obstruction depend on the size , mobility , and location of the tumor .
whether myxoma of the mitral valve causes an embolism more frequently than a myxoma originating from the left atrium is not known .
echocardiography can provide information on the location , size , shape , and mobility of a myxoma .
when abnormal mass lesions are found on the heart valve , it is important to distinguish tumorous conditions from valvular vegetations .
the characteristic narrow stalk is the most important feature of cardiac myxoma , and it is helpful when diagnostic confusion exists . the location of the mass also can help to discriminate between theses 2 conditions . as vegetations typically occur on the low pressure side of a high velocity turbulence jet , vegetations are often found on the atrial aspect of the mitral valve.16 ) however , there are no echocardiographic features that can absolutely differentiate myxomas from vegetations . therefore , clinical settings must be considered when diagnosing the patient . the treatment of choice for myxoma is surgical removal , and complete excision is the goal .
immediate postoperative mortality ranges from 0% to 3.6%.17)18 ) arrhythmia is a common postoperative complication , which may require long - term medication.18 ) recurrence develops in 3% of the patients , and the rate is higher in familial cardiac myxomas.19 ) it is not known whether replacement of mitral valve reduces the recurrence of mitral valve myxoma . | ### Summary:
: primary cardiac tumors are rare and myxoma is the most common tumor among them .
cardiac myxoma usually occurs in the left atrium .
myxoma originating from mitral valve is extremely rare .
we report a case of mitral valve myxoma .
the tumor originated from the anterior mitral valve leaflet .
the tumor was completely removed and replacement of the mitral valve was not done . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: patients with chronic kidney disease ( ckd ) undergoing dialysis have a higher risk of cardiovascular disease and mortality.1 vascular calcification is frequently observed among patients with ckd , and associations between vascular calcification and increased risk of mortality have been reported in several studies.25 secondary hyperparathyroidism ( shpt ) is a common complication observed in dialysis patients.6 goodman et al reported that elevation of calcium phosphorus product is associated with cardiovascular events and vascular calcification,7 and mineral and bone disorders induced by shpt have been considered to increase the risk of vascular calcification .
also , a high serum parathyroid hormone ( pth ) concentration is associated with cardiovascular events and mortality.811 cinacalcet hydrochloride ( cinacalcet ) is a calcimimetic agent that allosterically modulates the calcium - sensing receptor .
it reduces serum pth concentrations , and also decreases serum calcium and phosphorus concentrations simultaneously . to date
, there have been several reports regarding treatment with cinacalcet easily achieving the target range of calcium , phosphorus , and pth concentrations compared to conventional therapy for shpt.1215 in animal studies , pleiotropic effects of cinacalcet , such as improvement of parathyroid hyperplasia , osteitis fibrosa , osteoporosis , and vascular calcification have been shown.1622 in dialysis patients , tsuruta et al demonstrated improved coronary artery calcification scores by administration of cinacalcet.23 more recently , raggi et al suggested that cinacalcet may attenuate calcification of coronary artery in patients on hemodialysis in the advance ( study to evaluate cinacalcet plus low - dose vitamin d on vascular calcification in subjects with chronic kidney disease receiving hemodialysis ) trial,24 but investigations in regard to the effect of cinacalcet on vascular calcification are still quite few , and the clinical benefit of cinacalcet remains uncertain .
the aim of this study was to evaluate the associations between treatment with cinacalcet and the progression of vascular calcification among patients on maintenance hemodialysis with inadequately controlled shpt by conventional therapies .
subjects were 18 years or older , had undergone hemodialysis for > 12 months at shigei medical research hospital , okayama , japan , and had biochemical evidence of shpt with intact pth concentrations > 180 pg / ml during treatment with calcitriol analogs .
albumin - corrected serum calcium concentrations were > 8.4 mg / dl , and aortic calcification area index ( acai)25 at screening was 0 or > 60 in all subjects , as measured by multidetector computed tomography ( mdct ) .
the study protocol was approved by the ethics committee of shigei medical research hospital , and written informed consent was obtained from all participants .
the current investigation was a prospective cohort study in a single hospital , with all subjects treated with cinacalcet hydrochloride at a starting dose of 25 mg / day .
the dose was allowed to be adjusted in an attempt to achieve the target ranges specified in the japanese society for dialysis therapy ( jsdt ) guideline ( calcium 8.410.0 mg / dl , phosphorus 3.56.0 mg / dl , intact pth 60180 pg / ml).26 changes in cinacalcet dosage were recorded throughout the follow - up period , and the maximum dose of cinacalcet administered was 100 mg . for conventional therapy ,
concomitant treatment with phosphate binders was also permitted and could be adjusted without restriction throughout the study .
the duration of each dialysis treatment was 44.5 hours , and blood samples were drawn once a month at the beginning of the first hemodialysis session of the week .
systolic and diastolic blood pressures were measured in the supine position after 1015 minutes rest .
we measured the acai25 using mdct from 12 months before cinacalcet was started , and every 12 months thereafter , until 36 months after cinacalcet administration .
thus , we evaluated the percent annual change in the acai during the follow - up period . in figure 1 , the change in acai score in a representative case is shown .
using mdct , the area above bifurcation of the common iliac artery is scanned ten times at 1 cm intervals .
these scans are then analyzed by imagej27 ( national institutes of health , bethesda , md , usa ) to calculate the area of calcification in the abdominal aorta and the cross - sectional area of the aorta to calculate the calcified area as a percentage .
annual change in acai score , serum albumin - corrected calcium , serum phosphorus , calcium phosphorus product , and intact pth values were analyzed by repeated measures analysis of variance followed by tukey s post hoc test .
also , the change in acai / year was analyzed by unpaired t - test between the group of treatment with lanthanum carbonate and the others .
stepwise multivariate regression analysis was performed using % acai ( month 24/month 36/month12/0 ) = ( acai [ month 36]/acai [ month 24])/(acai [ month 0]/acai [ month12 ] ) as a dependent variable .
independent variables were sex and absolute changes in phosphorus , calcium phosphorus product , and intact pth from baseline to 36 months after cinacalcet administration .
doses of calcitriol analogs considered to be equivalent were 10 g maxacalcitol = 1.5 g calcitriol , and all results for injectable active calcitriol analog dosages are presented as calcitriol equivalents .
statistical analyses were performed by spss software ( version 20.0 ; ibm , armonk , ny , usa ) .
subjects were 18 years or older , had undergone hemodialysis for > 12 months at shigei medical research hospital , okayama , japan , and had biochemical evidence of shpt with intact pth concentrations > 180 pg / ml during treatment with calcitriol analogs .
albumin - corrected serum calcium concentrations were > 8.4 mg / dl , and aortic calcification area index ( acai)25 at screening was 0 or > 60 in all subjects , as measured by multidetector computed tomography ( mdct ) .
the study protocol was approved by the ethics committee of shigei medical research hospital , and written informed consent was obtained from all participants .
the current investigation was a prospective cohort study in a single hospital , with all subjects treated with cinacalcet hydrochloride at a starting dose of 25 mg / day .
the dose was allowed to be adjusted in an attempt to achieve the target ranges specified in the japanese society for dialysis therapy ( jsdt ) guideline ( calcium 8.410.0 mg / dl , phosphorus 3.56.0 mg / dl , intact pth 60180 pg / ml).26 changes in cinacalcet dosage were recorded throughout the follow - up period , and the maximum dose of cinacalcet administered was 100 mg . for conventional therapy ,
concomitant treatment with phosphate binders was also permitted and could be adjusted without restriction throughout the study .
the duration of each dialysis treatment was 44.5 hours , and blood samples were drawn once a month at the beginning of the first hemodialysis session of the week .
systolic and diastolic blood pressures were measured in the supine position after 1015 minutes rest .
we measured the acai25 using mdct from 12 months before cinacalcet was started , and every 12 months thereafter , until 36 months after cinacalcet administration .
thus , we evaluated the percent annual change in the acai during the follow - up period . in figure 1 , the change in acai score in a representative case is shown . using mdct , the area above bifurcation of the common iliac artery
these scans are then analyzed by imagej27 ( national institutes of health , bethesda , md , usa ) to calculate the area of calcification in the abdominal aorta and the cross - sectional area of the aorta to calculate the calcified area as a percentage .
annual change in acai score , serum albumin - corrected calcium , serum phosphorus , calcium phosphorus product , and intact pth values were analyzed by repeated measures analysis of variance followed by tukey s post hoc test .
also , the change in acai / year was analyzed by unpaired t - test between the group of treatment with lanthanum carbonate and the others .
stepwise multivariate regression analysis was performed using % acai ( month 24/month 36/month12/0 ) = ( acai [ month 36]/acai [ month 24])/(acai [ month 0]/acai [ month12 ] ) as a dependent variable .
independent variables were sex and absolute changes in phosphorus , calcium phosphorus product , and intact pth from baseline to 36 months after cinacalcet administration .
doses of calcitriol analogs considered to be equivalent were 10 g maxacalcitol = 1.5 g calcitriol , and all results for injectable active calcitriol analog dosages are presented as calcitriol equivalents .
statistical analyses were performed by spss software ( version 20.0 ; ibm , armonk , ny , usa ) .
the reasons for early withdrawal included death ( n=3 ) and kidney transplantation ( n=1 ) .
of the 43 patients who completed the study , no mdct scan ( n=12 ) , acai > 60 ( n=2 ) , acai = 0 ( n=2 ) , and twisted abdominal aorta ( n=4 ) were excluded because their aortas were not appropriate to assess the progression of calcification .
the mean age of 23 subjects who completed the study was 59.08.7 years , 34.8% were women , and mean dialysis duration was 163.076.0 months .
approximately 70% of the subjects were receiving injectable active calcitriol analogs at enrollment , and the mean dose was 1.561.26 g / week of calcitriol equivalents .
figure 2 shows the change in serum levels of intact pth , calcium , and phosphorus from baseline to the end of the follow - up period .
subjects started receiving 25 mg / day of cinacalcet at baseline , and the mean dosage of cinacalcet was 46.229.8 mg / day at 36 months .
none of the subjects had to discontinue treatment with cinacalcet due to side effects or noncompliance .
after administration of cinacalcet , serum intact pth levels decreased from 473.4220.1 pg / ml at baseline to 163.094.8 pg / ml at 12 months ( figure 2a , p<0.001 ) , and then remained stable throughout the study period .
after 36 months of cinacalcet treatment , 78.3% of subjects achieved intact pth concentration below the upper limit of the jsdt target range .
the mean serum phosphorus concentration decreased from 6.70.8 mg / dl to 5.60.9 mg / dl ( figure 2b , p<0.001 ) , and the mean corrected serum calcium concentration also decreased from 10.10.6 to 9.40.6 mg / dl ( figure 2c , p=0.001 ) .
the mean ca p values were significantly decreased from 67.47.9 mg / dl to 52.07.7 mg / dl ( figure 2d , p<0.001 ) .
after 36 months of treatment , subjects who achieved ca p < 55 mg / dl increased from 4.4% to 65.2% .
the use and dose of intravenous active calcitriol analogs remained largely unchanged from baseline to 36 months .
similarly , the percentages of the subjects taking sevelamer hydrochloride and calcium carbonate were stable throughout the study period ( table 2 ) .
after 24 months of cinacalcet administration , 65.2% of the subjects were treated with lanthanum carbonate . the change in acai score for an individual subject and mean values over the observation period
the mean acai value was 21.4% at baseline , 23.9% at 12 months , 23.7% at 24 months , and 24.3% at 36 months ( figure 3b ) .
the annual percentage changes in acai score from 12 months before cinacalcet administration to 36 months were 15.8218.25 ( 12 months before to baseline ) , 8.1010.01 ( baseline to 12 months ) , 6.4511.46 ( 12 months to 24 months ) , and 3.806.25 ( 24 months to 36 months ) ( figure 4 ) .
though acai values were not decreased in any of the subjects by cinacalcet administration , the percentage increase of acai / year was gradually suppressed . especially , the increase in acai / year between 24 and 36 months was significantly suppressed compared to that of between 12 months before cinacalcet administration and baseline ( p=0.001 ) . to determine potential factors responsible for the suppression of increase in acai
/ year , we examined associations between percentage changes in acai / year and biochemical response to cinacalcet by univariate and multivariate linear regression models ( tables 3 and 4 ) .
eventually female sex and reduction in p or ca p were independent determinants of suppression of increase in acai scores .
additionally there was no significant difference in the suppression of acai / year between the group treated with lanthanum carbonate ( n=15 ) and the other group ( n=8 ) ( data not shown ) .
the reasons for early withdrawal included death ( n=3 ) and kidney transplantation ( n=1 ) .
of the 43 patients who completed the study , no mdct scan ( n=12 ) , acai > 60 ( n=2 ) , acai = 0 ( n=2 ) , and twisted abdominal aorta ( n=4 ) were excluded because their aortas were not appropriate to assess the progression of calcification .
the mean age of 23 subjects who completed the study was 59.08.7 years , 34.8% were women , and mean dialysis duration was 163.076.0 months .
approximately 70% of the subjects were receiving injectable active calcitriol analogs at enrollment , and the mean dose was 1.561.26 g / week of calcitriol equivalents .
figure 2 shows the change in serum levels of intact pth , calcium , and phosphorus from baseline to the end of the follow - up period .
subjects started receiving 25 mg / day of cinacalcet at baseline , and the mean dosage of cinacalcet was 46.229.8 mg / day at 36 months .
none of the subjects had to discontinue treatment with cinacalcet due to side effects or noncompliance .
after administration of cinacalcet , serum intact pth levels decreased from 473.4220.1 pg / ml at baseline to 163.094.8 pg / ml at 12 months ( figure 2a , p<0.001 ) , and then remained stable throughout the study period .
after 36 months of cinacalcet treatment , 78.3% of subjects achieved intact pth concentration below the upper limit of the jsdt target range .
the mean serum phosphorus concentration decreased from 6.70.8 mg / dl to 5.60.9 mg / dl ( figure 2b , p<0.001 ) , and the mean corrected serum calcium concentration also decreased from 10.10.6 to 9.40.6 mg / dl ( figure 2c , p=0.001 ) .
the mean ca p values were significantly decreased from 67.47.9 mg / dl to 52.07.7 mg / dl ( figure 2d , p<0.001 ) .
after 36 months of treatment , subjects who achieved ca p < 55 mg / dl increased from 4.4% to 65.2% .
the use and dose of intravenous active calcitriol analogs remained largely unchanged from baseline to 36 months .
similarly , the percentages of the subjects taking sevelamer hydrochloride and calcium carbonate were stable throughout the study period ( table 2 ) .
after 24 months of cinacalcet administration , 65.2% of the subjects were treated with lanthanum carbonate .
the change in acai score for an individual subject and mean values over the observation period are presented in figure 3a and b , respectively .
the mean acai value was 21.4% at baseline , 23.9% at 12 months , 23.7% at 24 months , and 24.3% at 36 months ( figure 3b ) .
the annual percentage changes in acai score from 12 months before cinacalcet administration to 36 months were 15.8218.25 ( 12 months before to baseline ) , 8.1010.01 ( baseline to 12 months ) , 6.4511.46 ( 12 months to 24 months ) , and 3.806.25 ( 24 months to 36 months ) ( figure 4 ) .
though acai values were not decreased in any of the subjects by cinacalcet administration , the percentage increase of acai / year was gradually suppressed .
especially , the increase in acai / year between 24 and 36 months was significantly suppressed compared to that of between 12 months before cinacalcet administration and baseline ( p=0.001 ) .
to determine potential factors responsible for the suppression of increase in acai / year , we examined associations between percentage changes in acai / year and biochemical response to cinacalcet by univariate and multivariate linear regression models ( tables 3 and 4 ) .
eventually female sex and reduction in p or ca p were independent determinants of suppression of increase in acai scores .
additionally there was no significant difference in the suppression of acai / year between the group treated with lanthanum carbonate ( n=15 ) and the other group ( n=8 ) ( data not shown ) .
vascular and cardiac valve calcification are important predictors of cardiovascular disease and mortality among dialysis patients,28,29 and abdominal aortic calcification is also associated with coronary artery calcification , cardiovascular events , and mortality.2,3,30,31 wilson et al reported that abdominal aortic calcium deposits , detected by lumbar radiograms , are a marker of atherosclerotic disease and an independent predictor of subsequent vascular morbidity and mortality.32 at present , the effects of cinacalcet on coronary artery calcification have been tested in several studies , whereas little has been investigated regarding the effects of cinacalcet on abdominal aortic calcification . therefore , we focused on changes of abdominal aortic calcification in patients on dialysis to assess the effects of cinacalcet on vascular calcification . in our study protocol , we employed mdct scans and evaluated changes of abdominal aortic calcification more precisely by calculating acai , while calcification was measured by plain lateral radiographs in the previous cord ( calcification outcome in renal disease ) study.33 moreover , to our knowledge , this is the first attempt to assess changes of vascular calcification in hemodialysis patients using mdct for a period of 4 years .
in addition , the studied population in the current study was relatively young and included fewer diabetes patients with longer dialysis duration compared with those in european and us registries . to evaluate vascular calcification in hemodialysis patients
, we have to take the effect of calcitriol analogs into account , since it has been suggested that calcitriol analog administration progresses calcification in a dose - dependent manner . in the advance
study,24 patients on hemodialysis with shpt were divided into a calcitriol analog group and a calcitriol analog plus cinacalcet group randomly , and they were observed for 52 weeks . the result suggested that cinacalcet attenuates the progression of coronary artery calcification score , cardiac valve calcification , and calcification of the thoracic aorta .
however , doses of calcitriol analogs were significantly decreased in the calcitriol analog plus cinacalcet group during the study , indicating that administration of calcitriol analogs might affect the progression of vascular calcification . on the other hand ,
in the evolve ( evaluation of cinacalcet hcl therapy to lower cardiovascular events ) study , there were no significant differences in the incidence of cardiovascular events between the cinacalcet group and placebo group after 64 months of cinacalcet administration .
actually , baseline characteristics between the two groups , including cardiovascular morbidity , were imbalanced , and many patients in the cinacalcet group had their treatment aborted.34 even after completion of these trials , further investigation is needed to clarify the clinical benefits of cinacalcet . in the current study , the influence of calcitriol analogs on vascular calcification can be excluded , in contrast to the advance study , since doses of calcitriol analogs were stable during the study period .
thus , it is suggested that slower progression of aortic calcification in our subjects can be attributed to the administration of cinacalcet .
the actual acai value did not decrease after cinacalcet administration , but the annual change of the acai from 24 to 36 months was found to be significantly suppressed compared to from 12 months before to baseline .
though almost all of the patients were outside the target levels of serum calcium and phosphorus at baseline , apparent improvement in those levels was observed after 36 months of cinacalcet administration .
moreover , univariate and multivariate linear regression analyses revealed that lower levels of serum phosphorus were associated with the suppression of vascular calcification .
based on these results , the progression of vascular calcification may be suppressed by correcting the levels of phosphorus properly via the effect of cinacalcet , and it is suggested that starting cinacalcet at an earlier stage of hemodialysis could prevent progression of vascular calcification . though several reports have suggested the effect of cinacalcet against vascular calcification , there remains a fundamental question as to how calcimimetics work on the vascular wall in dialysis patients .
the calcium - sensing receptor is a target for therapeutic manipulation , since it proved to be expressed in aortic smooth - muscle cells . in a recent animal experiment ,
cinacalcet was considered to be a potential arterial relaxant candidate , acting predominantly by inhibiting ca influx through l - type ca channels into vascular smooth muscle.35 however , whether cinacalcet has a direct effect on smooth - muscle cell calcification remains uncertain , and this question needs to be elucidated in future investigations .
recently , cinacalcet has been reported to suppress serum fibroblast growth factor-23 levels and reduce serum phosphate concentration.36 there are several limitations in the current clinical investigation .
the sample size of the enrolled patients was small , the study was not randomized or double - blinded , and there was no control group .
the target range of intact pth at 60180 pg / ml was recommended in the jsdt guideline at the initiation of the study , but it was revised in 2012 , and the target levels of intact pth in the patients undergoing hemodialysis is recommended to be 60240 pg / ml.37 since the target was rather lower compared with kidney disease outcomes quality initiative guidelines ( 150300 pg / ml ) and kidney disease improving global outcomes guidelines ( two to nine times the upper normal limit for the assay ) , it can be associated with a high risk for adynamic bone disease . in the evaluation of aorta calcification ,
the area above bifurcation of the common iliac artery was scanned ten times at 1 cm intervals , but the current method has not been validated by clinical studies with larger populations .
in addition , the acai reflects both intimal and medial calcification , and fails to measure intimal calcification specifically , which is more tightly associated with atherosclerosis .
finally , we could not completely rule out the beneficial effects of lanthanum carbonate and other phosphate binders on the progression of aorta calcification .
lanthanum carbonate became commercially available in our country 12 months after our investigation started , and actually 65.2% of the subjects had been administrated lanthanum carbonate at the end of the study .
we clearly demonstrated that use of cinacalcet obviously suppressed the progression of abdominal aortic calcification throughout the observation period using mdct imaging .
longer - term , ie , 3-year , administration of cinacalcet may reduce arterial calcification and achieve appropriate calcium and phosphorus levels , bringing about a reduction in the incidence of cardiovascular events and mortality in patients on hemodialysis .
the percentage of calcification increased with time , even with cinacalcet treatment , and the therapy may be palliative rather than curative . to conclude that cinacalcet is truly clinically beneficial in preventing vascular calcification ,
larger randomized clinical trials with properly optimized protocols , such as early initiation of the agent , are required . | ### Summary:
: backgroundsecondary hyperparathyroidism ( shpt ) is one of the common complications in dialysis patients , and is associated with increased risk of vascular calcification .
the effects of cinacalcet hydrochloride treatment on bone and mineral metabolism have been previously reported , but the benefit of cinacalcet on vascular calcification remains uncertain .
the aim of this study was to evaluate the impact of cinacalcet on abdominal aortic calcification in dialysis patients.subjects and methodspatients were on maintenance hemodialysis with insufficiently controlled shpt ( intact parathyroid hormone [ pth ] > 180 pg / ml ) by conventional therapies .
all subjects were initially administered 25 mg cinacalcet daily , with concomitant use of calcitriol analogs .
abdominal aortic calcification was annually evaluated by calculating aortic calcification area index ( acai ) using multidetector computed tomography ( mdct ) , from 12 months before to 36 months after the initiation of cinacalcet therapy.resultstwenty-three patients were analyzed in this study .
the mean age was 59.08.7 years , 34.8% were women , and the mean dialysis duration was 163.076.0 months .
after administration of cinacalcet , serum levels of intact pth , phosphorus , and calcium significantly decreased , and mean ca p values significantly decreased from 67.47.9 mg2/dl2 to 527.7 mg2/dl2 .
although the acai value did not decrease during the observation period , the increase in acai between 24 months and 36 months after cinacalcet administration was significantly suppressed.conclusionlong-term administration of cinacalcet was associated with reduced progression of abdominal aortic calcification , and achieving appropriate calcium and phosphorus levels may reduce the rates of cardiovascular events and mortality in patients on hemodialysis . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: many common chronic diseases with adult onset show familial aggregation that usually does not follow mendelian patterns but appears to be caused by an unknown number of multiple genes , usually interacting with various environmental factors .
such conditions include coronary heart disease , hypertension , diabetes , obesity , various cancers , alzheimer 's disease , parkinson 's disease and others . in all such diseases , only a small fraction of affected individuals owes its origin to a single mutant gene transmitted by mendelian inheritance with characteristic transmission .
these genetically exceptional families often have an earlier age of onset and have more severe clinical manifestations .
so far , success in understanding " complex " diseases has been obtained most in the case of rare monogenic subtypes .
although the result on genetic mechanisms of majority of complex diseases is limited , several chromosomal sites of gene localization have often been reported .
we discuss a rare association of turner syndrome with both neurofibromatosis type i and tuberous sclerosis .
a 20-year - old turner syndrome ( ts ) patient with neurofibromatosis 1 ( nf1 ) and tuberous sclerosis complex ( tsc ) was apparently normal till five years of age .
she later started developing small skin lesions of the size of pin head over the face which gradually increased in size and number .
there was also a swelling over the left forearm , about the size of a marble , which gradually increased to attain the size as shown in figure 1a .
the developmental milestones were within normal limits and the patient had attained menarche at 12 years of age with regular menstrual cycles with no history of seizures . ( a ) typical features of tsc in the form of adenoma sebaceum , ( b ) plexiform neurofi broma and ( c ) periungual fibromas over of the left forearm swelling , and caf - au - lait spots hall mark of neurofibromatosis table 1 presents the phenotypic observation of the patient , in comparison with standard clinical manifestation . the expression level varies for all three disease conditions .
clinical investigations revealed that the girl had typical features of tsc in the form of adenoma sebaceum , plexiform neurofibroma shagreen patch and periungual fibromas [ figures 1a and b ] and multiple caf - au - lait spots ranging in size from 1.5 cm to 4 cm scattered all over the body confirmed nf1 [ figure 1c ] .
representing phenotypic observation of patient , in comparison with standard clinical manifestation along with nf 1 and tsc , turner features were evident with short stature , webbing of neck , low hair line , low set ears , high arched palate and cubitus valgus deformity .
about 10 - 20% of turner syndrome girls had spontaneous breast development and a small percentage may have menstrual periods .
the patient studied had also shown menstruation regularly with normal breast development , normal uterus and ovaries in pelvic ultrasound .
chromosomal analysis of the proband was carried out on peripheral blood lymphocyte culture by using the standard protocol of seabright . with slight modifications .
a total of 100 well banded metaphase plates were analyzed and karyotyped according to the international system for human cytogenetic nomenclature-2005 .
chromosome analysis of the patient confirmed with 45 , xo karyotype [ figure 2 ] .
an informed consent was obtained from the affected family members , before their inclusion in the study .
the arrow indicates the presence of only one x chromosome in karyotype pedigree of the proband family revealed that there was no parental consanguinity [ figure 3 ] . at the conception of the proband ,
there was no history of miscarriage or birth defects but her elder brother also had similar skin lesions over the face , which appeared at the age of seven years with adenoma sebaceum , shagreen patch revealed the appearance of tsc .
the roman number in the left side of the figure indicates the number of generation .
the number inside the symbol of father and mother in the 2 generation indicates their age when they gave birth to female and male children associated with all three disease conditions nf1 , tsc and ts and only tsc respectively
there are cases reported on the association with nf 1 and ts . and also nf 1 with tsc .
however , the association of nf 1 , tsc and turner syndrome has not been reported so for to our knowledge .
it is well known that nf1 and tsc are autosomal , dominant diseases . in our study ,
none of the parents and grandparents of the proband showed neither nf1 nor tsc but only one of the sibs of the proband manifested tsc .
therefore , one can surmise that both of these diseases caused due to new independent spontaneous mutations in proband and her elder brother .
as the woman age advances , the reproductive system exhibit changes like accumulation of environmental damage , reduced efficiency of dna repair , increased genomic instability , genetic factors , hormonal influences , suppressed apoptosis , or decreased effectiveness of antioxidants and micronutrients .
this leads to a sub - optimal resumption of meiosis i and meiosis ii , a change in ovarian functioning due to sub - optimal degradation of uterine environment , which are needed for proper meiotic segregation in the germ cells .
the elucidation of genetic risk factors for complex diseases will allow development of susceptibility testing for disease prediction .
unlike prediction of genetic risk in most " single gene " diseases prediction in complex disease will usually be probabilistic by providing a range of risks
. such testing will be particularly important for high risk individuals to prevent by diet , drugs , and/or lifestyle changes which will reduce the risk of these diseases . | ### Summary:
: we report a rare association of turner syndrome with both neurofibromatosis type i and tuberous sclerosis . the patient had xokaryotype with turners stigmata and also had features of neurofibromatosis 1 in the form of significant caf - au - lait spots and plexiform neurofibroma along with typical features of tuberous sclerosis complex .
pedigree analysis revealed that the elder brother of the proband in the family also suffered from tuberous sclerosis without the manifestation of neurofibromatosis or any other genetic disorders .
we hypothesize that these associations could be due to new independent mutations and also increased maternal and paternal age in a pre - disposition of turner syndrome . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: although both human immunodeficiency virus 1 and 2 ( hiv-1 and hiv-2 ) can cause acquired immune deficiency syndrome ( aids ) , the clinical and biological characteristics of infection with these two viruses show substantial differences , as well as similarities .
tuberculosis is a common opportunistic infection encountered in hiv-1 and also in hiv-2 infection . in this case report , we discussed the issues related to management of a patient of advanced hiv-2 and some of the important drug interactions which are likely to be encountered between antiretroviral therapy ( art ) and standard antituberculous treatment ( att ) .
the objective of this case report is to discuss effective antituberculous therapy in hiv-2 patients while preventing the emergence of drug resistance to art .
a 45-year - old man , farmer by occupation , was referred to our institution for management of hiv infection complicated by untoward effects related to art .
he was diagnosed to have hiv infection six years ago at a district center and cd4 count at that time was 114 cells/l .
after few years , he developed severe painful peripheral neuropathy for which art was stopped and the patient was referred to our institute for further management . as part of work up at our institute , western blot test was done which confirmed infection with hiv-2 .
contrast - enhanced ct scan of abdomen showed hepatosplenomegaly , para - aortic lymphadenopathy , and minimally enhancing splenic lesions at the level of splenic hilum [ figure 1 ] .
ultrasound - guided fine needle aspiration cytology from the spleen showed granulomas [ figure 2 ] .
patient was continued on the same antiretroviral treatment consisting of abacavir , tenofovir , and ritonavir - boosted lopinavir , and additionally , he was started on att consisting of isoniazid ( inh ) , pyrazinamide ( pza ) , ethambutol , and streptomycin for the first two months .
subsequently , he was continued on inh , pza , and ethambutol for 16 more months .
patient is presently on regular follow - up for last six years with good adherence to art .
contrast - enhanced ct scan of abdomen showing hepatosplenomegaly , para - aortic lymphadenopathy , and minimally enhancing splenic lesion at the level of splenic hilum fine needle aspiration cytology from the spleen showing clusters of epithelioid cells surrounded by few lymphocytes ( giemsa stain 40x ) suggestive of granulomas
hiv-2 infection is unique as it degrades the immune system more slowly than those who have hiv-1 infection .
however , the ultimate effects of hiv-2 infection are the same as hiv-1 and lead to aids .
hiv-2 infection is endemic in west africa and has spread in the last decade to india and europe .
kulkarni et al . from vellore have reported that the frequency of hiv-2 was around 3% of the total hiv infections .
it is important to realize that hiv-2 infections do prevail in india , though the incidence is much less than hiv-1 .
hiv-2 is sensitive to nucleoside reverse transcriptase inhibitors ( nrti ) and nucleotide analogues , such as tenofovir .
furthermore , hiv-2 is resistant to non - nucleoside reverse transcriptase inhibitors ( nnrti ) like efavirenz and nevirapine and the fusion inhibitor enfuvirtide .
another important consideration particular to indian patients is that the art centers supply same class of antiretroviral drugs to all hiv patients , irrespective of their hiv-1 or hiv-2 status .
if the hiv-2 patient takes only nucleoside and non - nucleoside analogue combination , there is a possibility of development of early resistance in this group .
after 12 weeks of starting the appropriate art , our patient developed fever with hepatosplenomegaly and caseating granulomas in spleen .
immune reconstitution inflammatory syndrome is characterized by a paradoxical deterioration of clinical condition , in whom arv has recently been initiated .
it is associated with a decrease in viral load and at least a partial recovery of immune competence , usually associated with increases in cd4 + t cell counts .
the improvement in cd4 counts along with fever and demonstration of caseating granulomas made us think of the possibility of immune reconstitution and inflammatory syndrome ( iris ) due to disseminated tuberculosis .
similar to the patient in our case report , iris due to tuberculosis usually manifests at around 1 to 3 months after starting art .
treatment of tuberculosis in hiv is also complicated by drug interactions and overlapping toxicities of antiretroviral drugs and antituberculous drugs .
rifampin induces the activity of cytochrome p-450 cyp3a , which lowers the concentrations of hiv - pis and non - nucleoside reverse - transcriptase inhibitors to subtherapeutic levels .
low trough plasma levels of these antiretroviral drugs are associated with incomplete viral suppression and the emergence of drug resistance in hiv .
the limited availability of antiretroviral drugs in india makes the treatment of hiv-2 infection even more difficult .
the treatment becomes much more complex when the patient needs att concomitantly . for patients with hiv-2 infection with tuberculosis , who are not on pis , standard att can be administered . in the present case ,
as rifabutin is a less potent inducer of cyp3a than rifampin , it can be administered in combination with the pi .
another option in a resource - limited setting like ours is that an alternative att regimen ( that does not include a rifamycin ) should be started to avoid the risk of development of subtherapeutic levels of pis .
it has been suggested that patients that have benefited from pis before the development of tuberculosis should generally continue to receive them during att .
though rifampicin is a very important part of att , we felt that an att regimen without rifampicin would allow the patient to continue the art which is best suited for him .
treatment of drug - susceptible tuberculosis should include a 6-month regimen with an initial phase of inh , rifampicin , pza , and ethambutol for two months , followed by inh and rifampicin for four additional months .
recommendations for anti - tb regimens in hiv - infected adults follow the same principles as for adults without hiv infection . another issue is the duration of att in regimens without rifampicin .
if rifampicin is not present in att regimens , an oral combination of inh , ethambutol , and pza for 18 to 24 months is preferable in most patients .
we feel that there is a need to tailor the att and art regimen for individual patients with the help of guidelines and experience .
every effort should be made by the physician to offer the most effective arv and att to curb drug resistance in patients with hiv and tuberculosis . | ### Summary:
: we present a case of human immunodeficiency virus 2 ( hiv- 2 ) infection with acquired immune deficiency syndrome with immune reconstitution and inflammatory syndrome due to disseminated tuberculosis .
we address here the drug interactions between antiretroviral therapy and antituberculous treatment ( att ) , choice of att , and duration of att when rifampicin is omitted as in our case .
though this problem is encountered rarely , we felt that it is important to report the issue to counter drug resistance in tuberculosis and hiv . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: many type 2 diabetes mellitus ( t2 dm ) patients suffer from diabetes - related cardiovascular complications , which are the major cause of death in patients with t2 dm .
atherosclerosis , a major risk factor for cardiovascular diseases , is a chronic disease characterized by two fundamental hallmarks : lipid accumulation and inflammation .
the interaction between these two processes defines the principal pathogenesis and distinguishes atherosclerosis from other chronic inflammatory disorders .
the dyslipidemia in t2 dm is characterized by increased low - density lipoprotein cholesterol ( ldl - c ) , elevated triglycerides ( tg ) , and decreased high - density lipoprotein cholesterol ( hdl - c ) , and it is associated with an increased risk of coronary artery disease .
statins , which decrease ldl - c levels and inhibit inflammatory responses , have been conclusively proven to significantly reduce cardiovascular events in many high - risk patients .
however , the residual risk remains after patients have achieved their target ldl - c levels through statins treatment .
combined with statins , fenofibrate has been shown to have highly beneficial effects on protecting against cardiovascular events in patients with type 2 diabetes associated with dyslipidemia .
fenofibrate is known as an important peroxisome proliferator - activated receptor- ( ppar- ) agonist , which is effective at decreasing tg levels , increasing hdl - c levels , and changing ldl particle morphology .
moreover , fenofibrate plays a pivotal role in regulating insulin resistance , fatty acid oxidation , cellular differentiation , and immune responses , such as inflammation or vascularization related to diabetic complications .
thus , ppar- agonists may reduce cardiovascular morbidity and mortality through lipid - lowering - dependent and lipid - lowering - independent mechanisms .
our previous studies have demonstrated that fenofibrate improved vascular endothelial function and regulated metabolism through comprehensive mechanisms [ 911 ] .
vascular endothelial dysfunction changes vascular permeability , allowing circulating monocytes and t cells to migrate into the subendothelial space .
the continued presence of immune cells , together with migration and proliferation of vascular smooth muscle cells , serves to perpetuate the inflammatory response and promote atherosclerotic plaque formation .
an advanced atherosclerotic plaque typically contains a mixture of proliferating smooth muscle cells , macrophages and t cells , and connective tissue , overlaid with a fibrous cap consisting of smooth muscle cells and matrix .
chemokines are inflammatory cytokines , which may lead to atherosclerosis and plaque destabilization not only by recruiting activated leukocytes into the lesion , but also by directly contributing to plaque rupture and thrombus formation .
the role of chemokines in atherosclerosis is further supported by several studies suggesting that chemokines may represent a link between lipids and inflammation in atherogenesis . regulated upon activation ,
normal t cells expressed and secreted ( rantes ) , also known as c - c chemokine ligand 5 ( ccl5 ) , belongs to the c - c chemokine family , which is secreted by many cell types , such as endothelial cells , smooth muscle cells , macrophages , platelets , and activated t cells .
our previous studies demonstrated that the circulating levels of rantes were elevated in hyperhomocysteinemia patients compared with controls and that upregulated rantes from monocytes in hyperhomocysteinemia patients was involved in hyperhomocysteinemia - induced atherosclerosis .
rantes administration has been proposed as a potential therapeutic strategy to protect the cardiovascular system [ 1618 ] ; thus , it may have implications for decreasing cardiovascular risk of t2 dm .
although ppar- agonists have been proven to reduce diabetic cardiovascular complications , its underlying mechanisms are still not fully clear .
the concept that atherosclerosis is an inflammatory disease is no longer controversial ; nevertheless , the regulation of the inflammatory processes and the pathogenic consequences remains uncertain .
ppar- has been reported to regulate rantes expression in vitro and in animal studies [ 1922 ] . however , to the best of our knowledge , the effect of ppar- agonist fenofibrate on rantes in diabetes patients has not been reported .
therefore , in the present study , we aimed to examine whether fenofibrate affected circulating rantes levels in t2 dm patients with hypertriglyceridemia .
all participants ( both males and females ) , ranging in age from 30 to 70 years , were recruited from september 2013 to january 2014 .
twenty - five type 2 diabetes mellitus patients with hypertriglyceridemia ( group a ) were recruited for this study from a group of outpatients at the department of endocrinology , beijing chao - yang hospital , capital medical university , beijing , china .
patients diagnosed with type 2 diabetes mellitus , as defined by the world health organization ( who ) criteria , and with stable hypoglycemic treatment for at least 3 months , fasting blood glucose ( fbg ) levels
< 9 mmol / l , and glycosylated hemoglobin ( hba1c ) levels < 8% , were eligible for the study .
additionally , the patients had been treated with 20 mg / day atorvastatin for more than 3 months , but their tg levels were still greater than 1.7 mmol / l .
the following exclusion criteria for group a were applied : known type 1 and other specific types of diabetes ( e.g. , genetic defects of the -cell , genetic defects in insulin action , diseases of the exocrine pancreas , endocrinopathies , drug- or chemical - induced diabetes , infections , uncommon forms of immune - mediated diabetes , or other genetic syndromes associated with diabetes ) according to the who classification of diabetes mellitus , genetic conditions affecting lipid metabolism ( e.g. , familial hypercholesterolemia , lipoprotein lipase deficiency ) , changes in hypoglycemic drugs or lipid - lowering drugs during the 3 months preceding the screening visit , any acute cardiovascular event within last 3 months , and contraindicating treatment with fenofibrate .
thirty - two healthy people ( group b ) were recruited as the control group from the community or from the group of people undergoing routine medical check - ups .
none of them had a history of prediabetes ( including impaired glucose tolerance and impaired fasting glucose ) , diabetes , hyperlipidemia , or cardiovascular disease .
moreover , people with hypertension , endocrine disease , systemic inflammatory disease , infectious disease , cancer , chronic kidney disease ( i.e. , serum creatinine [ cr ] > 120 mol / l ) , hepatic enzymes ( i.e. , aspartate aminotransferase [ ast ] and alanine aminotransferase [ alt ] ) > 1.5 times the upper normal limits , creatine kinase ( ck ) > 1.5 times the upper normal limit , a history of alcohol abuse , using heparin within last 3 months , pregnancy , and lactation were also excluded from both groups .
participants in group a were required to attend 3 study visits : the screening visit , visit 1 , and visit 2 ( spaced 8 weeks apart ) , while participants in group b attended the screening visit .
starting at visit 1 , the group a participants who fulfilled the inclusion criteria ( without any exclusion criterion ) were administered fenofibrate 200 mg / day for 8 weeks .
the capsules were counted at visit 2 , and compliance was considered to be satisfactory if > 90% of capsules were taken .
blood samples and the data on the medical history , height , weight , and blood pressure were collected at the screening visit ( groups a and b ) and at visit 2 ( group a ) under fasting conditions , as described below . at visit 1 , all participants in group a received instructions to maintain their usual nutritional and exercise habits and to not modify any drug treatment throughout the study .
participants in group a were asked to immediately report the development of unusual muscle soreness or pain throughout the study .
in addition , any adverse event in each group a participant was recorded at visit 2 .
the study protocol was approved by the medicine and pharmacy ethics committee of beijing chao - yang hospital , capital medical university . written informed consent was obtained from each participant prior to the performance of any study procedure .
a complete medical history , including duration and treatment of any disease , was obtained from each participant ; height and weight were determined using a standardized protocol .
body mass index ( bmi ) was calculated as weight ( kg)/[height ( m ) ] .
all readings were measured after a 5-min rest , with the patients in sitting position .
fasting blood samples were collected in the morning after an 8-h overnight fast . total cholesterol ( tc ) , hdl - c , tg , fbg , homocysteine ( hcy ) , high - sensitivity c - reactive protein ( hscrp ) , ast , alt , cr , ck , and hba1c
were measured in the central laboratory of beijing chao - yang hospital , capital medical university .
ldl - c was calculated using the friedewald formula ( ldl = chol[tg/5+hdl ] ) .
serum samples from all participants were promptly placed on ice after blood collection and were centrifuged at 4c within 30 min .
they were aliquoted and stored at 80c immediately after centrifugation , and we avoided any repeated thawing and freezing .
serum rantes concentrations were measured in duplicate at the same time using enzyme - linked immunosorbent assay ( elisa ) kits ( r&d systems , minneapolis , mn , usa ) for quantitative detection with an automated elisa reader ( varioskan flash-5250040 , thermo scientific , usa ) .
all analyses were performed with the statistical package for social sciences version 19.0 ( spss , inc . , chicago , il , usa ) .
comparisons of the baseline clinical and biochemical markers , as well as the rantes levels , between groups a and b were performed using an independent samples t test .
comparisons of the pre - treatment and post - treatment ( with fenofibrate ) clinical and biochemical markers , as well as the rantes levels , in group a were performed with the paired t test .
the association between the baseline values of rantes and the other baseline parameters was examined using pearson s and spearman s correlation coefficient analyses and multiple stepwise regression analysis . in all statistical tests , p values
< 0.05 were considered to be significant , and all tests were two - sided .
all participants ( both males and females ) , ranging in age from 30 to 70 years , were recruited from september 2013 to january 2014 .
twenty - five type 2 diabetes mellitus patients with hypertriglyceridemia ( group a ) were recruited for this study from a group of outpatients at the department of endocrinology , beijing chao - yang hospital , capital medical university , beijing , china .
patients diagnosed with type 2 diabetes mellitus , as defined by the world health organization ( who ) criteria , and with stable hypoglycemic treatment for at least 3 months , fasting blood glucose ( fbg ) levels
< 9 mmol / l , and glycosylated hemoglobin ( hba1c ) levels < 8% , were eligible for the study .
additionally , the patients had been treated with 20 mg / day atorvastatin for more than 3 months , but their tg levels were still greater than 1.7 mmol / l .
the following exclusion criteria for group a were applied : known type 1 and other specific types of diabetes ( e.g. , genetic defects of the -cell , genetic defects in insulin action , diseases of the exocrine pancreas , endocrinopathies , drug- or chemical - induced diabetes , infections , uncommon forms of immune - mediated diabetes , or other genetic syndromes associated with diabetes ) according to the who classification of diabetes mellitus , genetic conditions affecting lipid metabolism ( e.g. , familial hypercholesterolemia , lipoprotein lipase deficiency ) , changes in hypoglycemic drugs or lipid - lowering drugs during the 3 months preceding the screening visit , any acute cardiovascular event within last 3 months , and contraindicating treatment with fenofibrate .
thirty - two healthy people ( group b ) were recruited as the control group from the community or from the group of people undergoing routine medical check - ups .
none of them had a history of prediabetes ( including impaired glucose tolerance and impaired fasting glucose ) , diabetes , hyperlipidemia , or cardiovascular disease .
moreover , people with hypertension , endocrine disease , systemic inflammatory disease , infectious disease , cancer , chronic kidney disease ( i.e. , serum creatinine [ cr ] > 120 mol / l ) , hepatic enzymes ( i.e. , aspartate aminotransferase [ ast ] and alanine aminotransferase [ alt ] ) > 1.5 times the upper normal limits , creatine kinase ( ck ) > 1.5 times the upper normal limit , a history of alcohol abuse , using heparin within last 3 months , pregnancy , and lactation were also excluded from both groups .
participants in group a were required to attend 3 study visits : the screening visit , visit 1 , and visit 2 ( spaced 8 weeks apart ) , while participants in group b attended the screening visit .
starting at visit 1 , the group a participants who fulfilled the inclusion criteria ( without any exclusion criterion ) were administered fenofibrate 200 mg / day for 8 weeks .
the capsules were counted at visit 2 , and compliance was considered to be satisfactory if > 90% of capsules were taken .
blood samples and the data on the medical history , height , weight , and blood pressure were collected at the screening visit ( groups a and b ) and at visit 2 ( group a ) under fasting conditions , as described below . at visit 1 , all participants in group a received instructions to maintain their usual nutritional and exercise habits and to not modify any drug treatment throughout the study .
participants in group a were asked to immediately report the development of unusual muscle soreness or pain throughout the study .
in addition , any adverse event in each group a participant was recorded at visit 2 .
the study protocol was approved by the medicine and pharmacy ethics committee of beijing chao - yang hospital , capital medical university . written informed consent was obtained from each participant prior to the performance of any study procedure .
a complete medical history , including duration and treatment of any disease , was obtained from each participant ; height and weight were determined using a standardized protocol .
body mass index ( bmi ) was calculated as weight ( kg)/[height ( m ) ] .
all readings were measured after a 5-min rest , with the patients in sitting position .
total cholesterol ( tc ) , hdl - c , tg , fbg , homocysteine ( hcy ) , high - sensitivity c - reactive protein ( hscrp ) , ast , alt , cr , ck , and hba1c were measured in the central laboratory of beijing chao - yang hospital , capital medical university .
ldl - c was calculated using the friedewald formula ( ldl = chol[tg/5+hdl ] ) .
serum samples from all participants were promptly placed on ice after blood collection and were centrifuged at 4c within 30 min .
they were aliquoted and stored at 80c immediately after centrifugation , and we avoided any repeated thawing and freezing .
serum rantes concentrations were measured in duplicate at the same time using enzyme - linked immunosorbent assay ( elisa ) kits ( r&d systems , minneapolis , mn , usa ) for quantitative detection with an automated elisa reader ( varioskan flash-5250040 , thermo scientific , usa ) .
all analyses were performed with the statistical package for social sciences version 19.0 ( spss , inc . ,
comparisons of the baseline clinical and biochemical markers , as well as the rantes levels , between groups a and b were performed using an independent samples t test .
comparisons of the pre - treatment and post - treatment ( with fenofibrate ) clinical and biochemical markers , as well as the rantes levels , in group a were performed with the paired t test .
the association between the baseline values of rantes and the other baseline parameters was examined using pearson s and spearman s correlation coefficient analyses and multiple stepwise regression analysis . in all statistical tests , p values
< 0.05 were considered to be significant , and all tests were two - sided .
the participants in groups a and b were similar in sex , age , bmi , systolic blood pressure ( sbp ) and diastolic blood pressure ( dbp ) levels , and tc levels ( p>0.05 for all ) .
the ldl - c ( p<0.001 ) , tg ( p<0.001 ) , fbg ( p<0.001 ) , hba1c ( p<0.001 ) , hcy ( p=0.002 ) and hscrp ( p=0.001 ) levels were higher and the hdl - c levels ( p<0.001 ) were lower in group a compared with group b. the proportion of subjects of using aspirin ( p<0.001 ) , using metformin ( p<0.001 ) , using insulin secretagogue ( p<0.001 ) , using thiazolidinedione ( p<0.001 ) , using acarbose ( p<0.001 ) , using insulin ( p=0.013 ) , and using atorvastatin ( p<0.001 ) were higher in group a compared with group b. the fasting serum levels of rantes were significantly higher in group a than in group b ( 59.0416.74 vs. 38.5712.98 ng / ml , p<0.001 ) ( figure 1 ) .
the following parameters were found to be significantly correlated with the serum rantes levels : tg ( r=0.535 , p<0.001 ) , fbg ( r=0.485 , p<0.001 ) , hba1c ( r=0.485 , p<0.001 ) , hcy ( r=0.520 , p<0.001 ) , and hscrp ( r=0.701 , p<0.001 ) ( table 2 ) .
multiple stepwise regression analysis was performed to determine the parameters that were independently associated with serum rantes .
the results showed that increased hscrp ( =7.430 , p<0.001 ) and t2 dm with hypertriglyceridemia ( =11.496 , p=0.002 ) were independently related to high serum rantes levels after adjusting for all clinical characteristics and drug usage .
the model had an adjusted r squared of 0.551 , f=35.407 and p<0.001 ( table 3 ) .
the pre - treatment and post - treatment ( with fenofibrate ) clinical parameters in group a are summarized in table 4 . compared with baseline , at visit 2 ,
the patients in group a presented significantly lower levels of tg ( p<0.001 ) and hscrp ( p=0.020 ) but significantly higher levels of hdl - c ( p<0.001 ) .
in addition , no statistically significant changes were observed in bmi , sbp , dbp , tc , ldl , fbg , ast , alt , ck , cr , or hcy after 8 weeks of fenofibrate treatment compared with baseline ( p>0.05 for all ) .
after 8 weeks of fenofibrate treatment , the serum rantes levels in group a were significantly decreased compared with the baseline levels ( from 59.0416.74 ng / ml at pre - treatment to 52.7517.41 ng / ml at post - treatment , p=0.018 ) ( figure 2 ) .
all participants completed the study , and no serious adverse effects were observed during the study .
the participants in groups a and b were similar in sex , age , bmi , systolic blood pressure ( sbp ) and diastolic blood pressure ( dbp ) levels , and tc levels ( p>0.05 for all ) .
the ldl - c ( p<0.001 ) , tg ( p<0.001 ) , fbg ( p<0.001 ) , hba1c ( p<0.001 ) , hcy ( p=0.002 ) and hscrp ( p=0.001 ) levels were higher and the hdl - c levels ( p<0.001 ) were lower in group a compared with group b. the proportion of subjects of using aspirin ( p<0.001 ) , using metformin ( p<0.001 ) , using insulin secretagogue ( p<0.001 ) , using thiazolidinedione ( p<0.001 ) , using acarbose ( p<0.001 ) , using insulin ( p=0.013 ) , and using atorvastatin ( p<0.001 ) were higher in group a compared with group b.
the fasting serum levels of rantes were significantly higher in group a than in group b ( 59.0416.74 vs. 38.5712.98 ng / ml , p<0.001 ) ( figure 1 ) .
the following parameters were found to be significantly correlated with the serum rantes levels : tg ( r=0.535 , p<0.001 ) , fbg ( r=0.485 , p<0.001 ) , hba1c ( r=0.485 , p<0.001 ) , hcy ( r=0.520 , p<0.001 ) , and hscrp ( r=0.701 , p<0.001 ) ( table 2 ) .
multiple stepwise regression analysis was performed to determine the parameters that were independently associated with serum rantes .
the results showed that increased hscrp ( =7.430 , p<0.001 ) and t2 dm with hypertriglyceridemia ( =11.496 , p=0.002 ) were independently related to high serum rantes levels after adjusting for all clinical characteristics and drug usage .
the model had an adjusted r squared of 0.551 , f=35.407 and p<0.001 ( table 3 ) .
the pre - treatment and post - treatment ( with fenofibrate ) clinical parameters in group a are summarized in table 4 . compared with baseline , at visit 2 ,
the patients in group a presented significantly lower levels of tg ( p<0.001 ) and hscrp ( p=0.020 ) but significantly higher levels of hdl - c ( p<0.001 ) .
in addition , no statistically significant changes were observed in bmi , sbp , dbp , tc , ldl , fbg , ast , alt , ck , cr , or hcy after 8 weeks of fenofibrate treatment compared with baseline ( p>0.05 for all ) .
after 8 weeks of fenofibrate treatment , the serum rantes levels in group a were significantly decreased compared with the baseline levels ( from 59.0416.74 ng / ml at pre - treatment to 52.7517.41 ng / ml at post - treatment , p=0.018 ) ( figure 2 ) .
all participants completed the study , and no serious adverse effects were observed during the study .
in this study we demonstrated that serum rantes levels were significantly higher in the t2 dm patients with hypertriglyceridemia compared with the controls , and that serum rantes was positively correlated with tg , fbg , hba1c , hcy , and hscrp .
after controlling for confounders , increased hscrp levels and t2 dm with hypertriglyceridemia were independently related to high serum rantes levels .
our findings agree with studies indicating that circulating rantes was significantly higher in patients with hypertriglyceridemia or with t2 dm compared with controls , and was positively related to fbg . furthermore , our finding that serum rantes was positively associated with hcy support our previous result that the circulating rantes levels were elevated in hyperhomocysteinemia patients compared with controls .
in addition , our finding that serum rantes was positively correlated with hscrp , a biomarker of inflammation and an independent predictor for cardiovascular events , suggested that rantes might play an important role in the inflammatory processes and cardiovascular diseases .
accumulating evidence has demonstrated that ppar- is an important modulator of metabolic syndrome and that it might be useful as a therapeutic target for treating some of its features .
ppar- agonist has been proven to be effective at lowering plasma levels of glucose , insulin , triglycerides , and free fatty acids in ob / ob mice .
its known target genes are involved in most aspects of lipid metabolism and lipid transport . in our study ,
the t2 dm patients with hypertriglyceridemia presented significantly lower levels of tg but demonstrated significantly higher levels of hdl - c after 8 weeks of fenofibrate treatment compared with baseline .
importantly , we report for the first time that fenofibrate treatment administered to t2 dm patients with hypertriglyceridemia for 8 weeks resulted in a significant decrease in serum rantes levels , suggesting that ppar- agonists may lead to the inhibition of cardiovascular diseases , independent of their effects on lipid metabolism .
moreover , activation of ppar- protected the heart from ischemia / reperfusion injury . the fenofibrate intervention and event lowering in diabetes ( field ) study revealed that total cardiovascular events were significantly reduced through fenofibrate treatment .
although ppar- agonists might protect against cardiovascular diseases , the mechanisms are still not fully understood .
it has been reported that ppar- agonists decrease the progression of atherosclerosis , mainly by modulating metabolic risk factors and by their anti - inflammatory actions on the level of the vascular wall .
our previous study demonstrated that fenofibrate improved coronary flow velocity reserve and arterial stiffness in patients with hypertriglyceridemia , upregulated tetrahydrobiopterin levels by increasing the expression of guanosine triphosphate cyclohydrolase - i in human umbilical vein endothelial cells , and decreased circulating irisin levels in type 2 diabetes patients with hypertriglyceridemia .
ppar- agonists were reported to increase the expression of endothelial nitric oxide synthase ( enos ) and the production of nitric oxide ( no ) .
ppar- agonists have been proven to reduce hscrp levels and to repress the production of some inflammatory cytokines . in our present study , hscrp levels
were also significantly decreased in type 2 diabetes patients with hypertriglyceridemia after 8 weeks of ppar- agonist fenofibrate treatment .
based on these results , it appears that ppar- agonists have an anti - atherosclerotic effect through anti - inflammation .
activation of ppar- interferes with early steps in atherosclerosis by reducing leukocyte adhesion to activated endothelial cells of the arterial vessel wall and by inhibiting subsequent transendothelial leukocyte migration . in addition , in later stages of atherosclerosis , activation of ppar- suppresses the formation of macrophage foam cells and reactive oxygen species , and reduces associated - lipoprotein oxidative modification .
therefore , ppar- agonists may inhibit the formation of atherosclerotic lessons and may increase the stability of atherosclerotic plaques through suppressing inflammatory responses .
recent evidence has indicated that rantes is associated with cardiovascular events . however , the data have been inconsistent .
increased levels of rantes were reported in patients with acute coronary syndromes compared with controls and were proven in patients with refractory ischemic symptoms compared with stabilized patients .
rantes levels were associated with carotid wall thickness and lipid - core volume , suggesting that higher rantes levels might be related to extensive carotid atherosclerosis and plaque at high risk of rupturing .
therefore , rantes inhibition is believed to induce cardioprotective effects through its anti - inflammatory properties . by its ability to bind to its chemokine receptors expressed on t cells or monocytes , rantes
might lead to the adhesion and the transmigration of t cells and monocytes through the endothelial wall ; thus , blocking these receptors by injecting rantes receptor antagonists could suppress atherosclerosis and might reduce the infarct size .
controversially , there have been some studies suggesting that low rantes levels might be correlated with atherosclerosis .
it might be hypothesized that the decreased rantes levels in patients with high frequency of cardiovascular events could reflect increased deposition of rantes on the vascular endothelium leading to more rantes receptor stimulation .
it is possible that these conflicting data are caused by the poly - pharmacotherapy or other confounding variables of the study populations , such as age , sex , and species of the subjects .
these discrepancies might also be due to differences in the assays used by the different studies .
it has been demonstrated that ppar- agonists inhibited rantes expression in vitro and in animal studies .
fibrates repressed expression of rantes induced by tumor necrosis factor- and by chenodeoxycholic acid in human hepatocyte - derived cells .
wy-14,643 , a fibrate class of ppar- ligands , significantly inhibited cisplatin - induced upregulation of rantes in acute renal failure mice . additionally , after treatment with ppar- agonist ( r)-k-13675 , rantes levels were significantly suppressed in human coronary endothelial cells .
our present study demonstrated that serum rantes levels were reduced through fenofibrate treatment in type 2 diabetes mellitus patients with hypertriglyceridemia .
our findings in the present study may partially explain the beneficial effects of ppar- agonist treatment in clinical trials in which the favorable effects were only partly correlated with lipid changes , although further animal and clinical studies are still needed to investigate the mechanisms by which ppar- agonists protect against the cardiovascular complications of diabetes .
secondly , our sample size was relatively small , so our findings might not be powerful enough to account for potentially confounding factors in our analysis , and our results could be improperly influenced by some outliers due to the sample size .
however , we performed post hoc sample size calculation ( with g*power 3.1.9.2 ) showing that the power to compare the baseline rantes levels between the type 2 diabetes patients with hypertriglyceridemia group and the control group was 1.00 , and that the power to compare the pre - treatment and post - treatment ( with fenofibrate ) rantes levels in the type 2 diabetes patients with hypertriglyceridemia group was 0.78 ( =0.05 , one - sided test , according to previous studies ) .
additionally , a small sample size may result in a type ii error in the statistical analysis , but we have demonstrated that fenofibrate decreased serum rantes levels in t2 dm patients with hypertriglyceridemia in the present study . therefore , the power of the analyses might be sufficient in our study .
thirdly , we used serum samples rather than platelet - free plasma for detecting rantes levels .
however , given our precautions to prevent degradation of rantes after blood collection and during storage , exclusion of using heparin , and to compare the difference between the pre - treatment and post - treatment ( with fenofibrate ) rantes levels detected by the same elisa kits at the same time in the same condition , this methodological problem did not obviously affect the outcomes of our study .
moreover , some studies have demonstrated that measuring rantes levels in serum and in platelet - free plasma presented similar patterns of results .
fourthly , fenofibrate treatment was administered to t2 dm patients with hypertriglyceridemia in our present study .
unfortunately , for several reasons this treatment is sometimes not appropriate ( e.g. , intolerance , adverse effects , and patient preference ) .
nutraceuticals and functional food ingredients that are also beneficial to vascular health may are useful compounds that might be able to reduce the overall cardiovascular risk induced by dyslipidemia in situations where fenofibrate can not be used .
the mechanisms underlying such actions are not fully understood , and the effect of nutraceuticals and functional food ingredients on rantes and inflammation remains to be further investigated . finally , the cross - sectional design of the study prevented us from determining a causal relationship , but it can certainly raise a credible hypothesis to be confirmed and extended by future prospective cohort and mechanistic studies . despite these limitations , our results still provide strong evidence for the effectiveness of fenofibrate in reducing circulating rantes levels .
we presented novel data that fenofibrate treatment significantly decreased serum rantes levels in type 2 diabetes mellitus patients with hypertriglyceridemia . | ### Summary:
: backgroundregulated upon activation , normal t cells expressed and secreted ( rantes ) is associated with inflammation and atherosclerosis .
we investigated the effect of fenofibrate , a peroxisome proliferator - activated receptor- ( ppar- ) agonist , on rantes in type 2 diabetes mellitus ( t2 dm ) patients with hypertriglyceridemia.material/methodsthis study evaluated cross - sectional and interventional studies of 25 t2 dm patients with hypertriglyceridemia ( group a ) and 32 controls ( group b ) .
group a was treated with fenofibrate ( 200 mg / day ) for 8 weeks .
serum rantes and clinical characteristics were examined.resultsserum rantes was significantly higher in group a compared with group b ( 59.0416.74 vs. 38.5712.98 ng / ml , p<0.001 ) and correlated with triglycerides ( tg ) ( r=0.535 , p<0.001 ) , fasting blood glucose ( fbg ) ( r=0.485 , p<0.001 ) , glycosylated hemoglobin ( hba1c ) ( r=0.485 , p<0.001 ) , homocysteine ( hcy ) ( r=0.520 , p<0.001 ) , and high - sensitivity c - reactive protein ( hscrp ) ( r=0.701 , p<0.001 ) . in multiple regression analysis after controlling for confounders , increased hscrp levels ( =7.430 , p<0.001 ) and t2 dm with hypertriglyceridemia ( =11.496 , p=0.002 ) were independently related to high serum rantes levels .
after 8 weeks of fenofibrate treatment , serum rantes significantly decreased in group a compared with baseline ( 52.7517.41 vs. 59.0416.74 ng / ml , p=0.018).conclusionsfenofibrate decreased serum rantes levels in t2 dm patients with hypertriglyceridemia , indicating that ppar- agonists may play an important role in inhibiting inflammatory responses . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the reliable determination of lv function is an important component of the cardiac evaluation in several clinical settings [ 13 ] .
previous studies demonstrated that magnetic resonance imaging ( mri ) is an accurate and reproducible technique for the measurement of lv volumes and is currently regarded as the reference standard [ 46 ] .
a two - dimensional ( 2d ) balanced steady - state free precession gradient echo sequence ( b - ssfp ) is currently considered the preferred method to assess lv volume and function because of its high spatial and temporal resolution [ 5 , 79 ] .
however , 2d b - ssfp sequence has an important limitation in that it requires multiple prolonged breath - holds that increase examination time and may cause patient restlessness and slice mis - registration [ 10 , 11 ] .
recently , a new speed - up technique , k - t blast ( broad - use linear acquisition speed - up technique ) , has become available ; it allows an undersampling in the temporal domain and , applied to a 3d - cine b - ssfp sequence , may allow coverage of the entire left ventricle in a single breath - hold , as explained in previous papers [ 1114 ] .
the performance of this 3d - cine sequence has until now not been evaluated in a clinical setting [ 15 , 16 ] .
furthermore , most authors used two breath - holds to have the volume dataset acquired available for analysis ; they performed the second breath - hold to acquire the training dataset
we set a true single breath - hold 3d sequence , with no necessity to acquire the training data with a second breath - hold , and we sought to investigate the variability of lv volume and mass measurements and the time efficiency of this new single breath - hold 3d - cine sequence using a standard multiple breath - hold 2d - cine sequence as reference .
forty - eight patients , who were referred for mri assessment of lv function for different indications , were prospectively enrolled for the study .
exclusion criteria for mri were the standard absolute and relative contraindications for mri : patients with claustrophobia , pace - maker and other mri - incompatible devices were not considered for this study .
the inclusion criterion was the ability to perform a breath - hold of at least 18 s. the study was approved by the local ethics committee and all patients gave informed consent .
all imaging was performed in the tertiary referral hospital ( parma , italy ) , using a 1.5-t mri ( achieva , philips medical systems , best , the netherlands ) with : maximum gradient strength 66 mt / m , maximum slew rate 180 mt / m ms , maximum gradient strength during cine - cardiac mri acquisition 33 mt / m , and maximum slew rate during cine - cardiac mri acquisition 180 mt / m ms .
five - element synergy cardiac coil and vector electrocardiography were used for signal detection and cardiac gating . one experienced operator ( 3 years cardiac mri ) performed all the examinations .
after initial scout imaging and reference acquisition , both the 2d b - ssfp ( 2d - cine ) and the 3d b - ssfp k - t blast ( 3d - cine ) sequences were acquired on the short axis plane covering the entire left ventricle .
table 1sequence parameterstrteflip anglebandwidthin plane resolutionslice thicknessslice gaptemporal resolutioncardiac phasesensepartial imagek - t blast factor2d - cine3.11.53601,249.7 hz / pixel2 2.3 mm8 mm2 mm32 6 ms30offyes03d - cine3.21.59501,388.5 hz / pixel2.4 2.75 mm059 11 ms16offyes4tr time of repetition , te time of echo tr time of repetition , te time of echo we used a retrospective gated sequence for 2d - cine and a gated sequence for 3d - cine because software constraints did not permit a true retrospective gating . two experienced observers ( 3 and 4 years cardiac mri ) analysed images with an off - line post - processing workstation ( viewforum release 4.2 , philips medical system ) .
first , a visual evaluation was performed on each volume dataset distinguishing reportable and non - reportable datasets .
next , the end - diastolic and end - systolic phases were identified ; the first image of the cardiac cycle ( 0% ) was considered to be end - diastolic , whereas the image with the smallest lv cavity was considered to be end - systolic ; then both the endocardial and epicardial contours were manually traced on the short - axis views on end - diastolic phase images , endocardial borders were propagated thanks to the software on end - systolic phase images and finally manual correction of contours was performed by the operators . on end - diastolic and end - systolic phase images ,
the first section of the lv with a visible lumen was defined as the apex , whereas the base was defined as the most basal section surrounded by at least 50% myocardium .
papillary muscles and trabeculations in the lv cavity were included in the lv volume as previously described .
cardiac functional parameters were evaluated in both 2d - cine and 3d - cine sequences ( fig . 1 ) .
in particular , end - diastolic volume ( edv ) , end - systolic volume ( esv ) , lv ejection fraction ( ef ) , stroke volume ( sv ) and end - diastolic wall mass of the left ventricle ( ed wall mass ) .
we reported the acquisition time and the evaluation time for each patient and for each sequence .
acquisition time for 2d cine multiple breath - holds was reported as effective acquisition time
, where the effective acquisition time was calculated taking into account the recovery time between the single breath - holds .
we also calculated the temporal resolution obtained with 2d - cine and 3d - cine sequences for each patient : temporal resolution was calculated by dividing the r - r interval for the number of phases inherent to each type of sequence .
the figure shows the same patient studied with the two different sequences . in a and b the 2d- and 3d - sequences
are displayed in the argus ( siemens , germany ) platform before the quantitative assessment . in c and d ,
the 2d and 3d sequence are displayed during the contour detection in the end - diastolic phase , respectively examples of 2d and 3d sequences .
the figure shows the same patient studied with the two different sequences . in a and b the 2d- and 3d - sequences
are displayed in the argus ( siemens , germany ) platform before the quantitative assessment . in c and d ,
the 2d and 3d sequence are displayed during the contour detection in the end - diastolic phase , respectively the 2d - cine sequence was used as the reference standard .
the performance of 2d - cine and 3d - cine were compared using the paired student s t - test and a p < 0.05 was defined as statistically significant . correlations between edv , esv , lv ef , and lv ed wall mass between the two sequences were assessed using pearson s correlation analysis .
agreement on the lv parameters between 2d and 3d sequences were assessed using bland - altman analysis .
the time - efficiency differences were made using the paired student s t - test and a p < 0.05 was defined as statistically significant .
statistical analysis exploring the impact of intra- and inter - observer variability was performed using the same methodology .
forty - eight patients , who were referred for mri assessment of lv function for different indications , were prospectively enrolled for the study .
exclusion criteria for mri were the standard absolute and relative contraindications for mri : patients with claustrophobia , pace - maker and other mri - incompatible devices were not considered for this study .
the inclusion criterion was the ability to perform a breath - hold of at least 18 s. the study was approved by the local ethics committee and all patients gave informed consent .
all imaging was performed in the tertiary referral hospital ( parma , italy ) , using a 1.5-t mri ( achieva , philips medical systems , best , the netherlands ) with : maximum gradient strength 66 mt / m , maximum slew rate 180 mt / m ms , maximum gradient strength during cine - cardiac mri acquisition 33 mt / m , and maximum slew rate during cine - cardiac mri acquisition 180 mt / m ms .
five - element synergy cardiac coil and vector electrocardiography were used for signal detection and cardiac gating . one experienced operator ( 3 years cardiac mri ) performed all the examinations .
after initial scout imaging and reference acquisition , both the 2d b - ssfp ( 2d - cine ) and the 3d b - ssfp k - t blast ( 3d - cine ) sequences were acquired on the short axis plane covering the entire left ventricle .
table 1sequence parameterstrteflip anglebandwidthin plane resolutionslice thicknessslice gaptemporal resolutioncardiac phasesensepartial imagek - t blast factor2d - cine3.11.53601,249.7 hz / pixel2 2.3 mm8 mm2 mm32 6 ms30offyes03d - cine3.21.59501,388.5 hz / pixel2.4 2.75 mm059
11 ms16offyes4tr time of repetition , te time of echo tr time of repetition , te time of echo we used a retrospective gated sequence for 2d - cine and a gated sequence for 3d - cine because software constraints did not permit a true retrospective gating .
two experienced observers ( 3 and 4 years cardiac mri ) analysed images with an off - line post - processing workstation ( viewforum release 4.2 , philips medical system ) .
first , a visual evaluation was performed on each volume dataset distinguishing reportable and non - reportable datasets .
next , the end - diastolic and end - systolic phases were identified ; the first image of the cardiac cycle ( 0% ) was considered to be end - diastolic , whereas the image with the smallest lv cavity was considered to be end - systolic ; then both the endocardial and epicardial contours were manually traced on the short - axis views on end - diastolic phase images , endocardial borders were propagated thanks to the software on end - systolic phase images and finally manual correction of contours was performed by the operators . on end - diastolic and end - systolic phase images ,
the first section of the lv with a visible lumen was defined as the apex , whereas the base was defined as the most basal section surrounded by at least 50% myocardium .
papillary muscles and trabeculations in the lv cavity were included in the lv volume as previously described .
cardiac functional parameters were evaluated in both 2d - cine and 3d - cine sequences ( fig . 1 ) .
in particular , end - diastolic volume ( edv ) , end - systolic volume ( esv ) , lv ejection fraction ( ef ) , stroke volume ( sv ) and end - diastolic wall mass of the left ventricle ( ed wall mass ) . we reported the acquisition time and the evaluation time for each patient and for each sequence .
acquisition time for 2d cine multiple breath - holds was reported as effective acquisition time
, where the effective acquisition time was calculated taking into account the recovery time between the single breath - holds
. we also calculated the temporal resolution obtained with 2d - cine and 3d - cine sequences for each patient : temporal resolution was calculated by dividing the r - r interval for the number of phases inherent to each type of sequence .
the figure shows the same patient studied with the two different sequences . in a and b the 2d- and 3d - sequences
are displayed in the argus ( siemens , germany ) platform before the quantitative assessment . in c and d ,
the 2d and 3d sequence are displayed during the contour detection in the end - diastolic phase , respectively examples of 2d and 3d sequences .
the figure shows the same patient studied with the two different sequences . in a and b the 2d- and 3d - sequences
are displayed in the argus ( siemens , germany ) platform before the quantitative assessment . in c and d ,
the 2d and 3d sequence are displayed during the contour detection in the end - diastolic phase , respectively
the performance of 2d - cine and 3d - cine were compared using the paired student s t - test and a p < 0.05 was defined as statistically significant . correlations between edv , esv , lv ef , and lv ed wall mass between the two sequences were assessed using pearson s correlation analysis . agreement on the lv parameters between 2d and 3d sequences were assessed using bland - altman analysis .
the time - efficiency differences were made using the paired student s t - test and a p < 0.05 was defined as statistically significant .
statistical analysis exploring the impact of intra- and inter - observer variability was performed using the same methodology .
of the enrolled population ( 48 patients ) undergoing 2d - cine and 3d - cine sequences , 46 patients had visually optimal image quality , and we had to exclude two patients because of blurring artefacts .
all calculated parameters with the two sequences showed significant differences ( p < 0.05 ) .
in particular , we observed an under - estimation of edv ( 129 44 ml vs 134 49 ml , p < 0.05 ) and over - estimation of the esv ( 77 44 ml vs 73 50 ml , p < 0.05 ) in 3d - cine .
this resulted in an under - estimation of ef ( 43 15% vs 48 15% with p < 0.01 ) , sv ( 52 19 ml vs 60 21 ml with p < 0.05 ) and co ( 3.3 1.3 ml vs 3.9 1.3 ml with p < 0.05 ) in 3d - cine . despite the differences
, an excellent correlation was found between measurements , in particular for ef ( r = 0.99 ; table 3 )
. bland - altman analysis on lv functional parameters between 2d - cine and 3d - cine sequences , using limits of agreement ( 1.96 sds from the mean difference ) , showed good results .
the mean difference for the ef was 5% ( limits of agreement 2.77.6% ; fig . 2 ) .
table 2baseline characteristicsparametersvaluesnumber of patients46male / female29/17mean age ( years ) sd51 19mean weight ( kg ) sd75 16mean heart rate ( bpm ) sd65 13clinical indicationsvaluescad29dcm9hcm3valve study3arvd2sd standard deviation , cad coronary artery disease , dcm dilated cardiomyopathy , hcm hypertrophic cardiomyopathy , arvd arrhythmogenic right ventricular dysplasiatable 3comparison of global lv parameters calculated with 2d and 3d k - t blast sequences .
parameters are expressed as mean sd ; p value student s paired test ; r value pearson s correlation ; 95% la limits of agreement with bland - altman analysislv parameters2d3d k - t blastp valuer value95% laedv ( ml)134 49129 44<0.050.98 - 16.4 ; 26.6esv ( ml)73 5077 47<0.050.99 - 16.7 ; 9.7sv ( ml)60 2152 19<0.050.96 - 2.7 ; 19.9ef ( % ) 48 1543 15<0.010.992.7 ; 7.6co ( l / min)3.9 1.33.3 1.3<0.050.95 - 0.20 ; 1.34ed wall mass
( g)72 2381 24<0.050.97 - 19.7 ; 1.6lv left ventricle , edv end diastolic volume , esv end systolic volume , sv stroke volume , ef ejection fraction , co cardiac output , ed wall mass end diastolic wall massfig .
a good agreement was found for edv and esv ; a dispersion of measurement was found for the ef and the ed wall mass baseline characteristics sd standard deviation , cad coronary artery disease , dcm dilated cardiomyopathy , hcm hypertrophic cardiomyopathy , arvd arrhythmogenic right ventricular dysplasia comparison of global lv parameters calculated with 2d and 3d k - t blast sequences .
parameters are expressed as mean sd ; p value student s paired test ; r value pearson s correlation ; 95% la limits of agreement with bland - altman analysis lv left ventricle , edv end diastolic volume , esv end systolic volume , sv stroke volume , ef ejection fraction , co cardiac output , ed wall mass end diastolic wall mass bland - altman plots .
a good agreement was found for edv and esv ; a dispersion of measurement was found for the ef and the ed wall mass time - efficiency was calculated taking into account the effective acquisition time and reporting time .
total imaging time was significantly shorter for 3d - cine than for multiple 2d - cine ( 18 1 s vs 95 23 s with p < 0.05 ) .
the average heart rate was not significantly different during 3d - cine and 2d - cine sequences ( 65 13 bpm vs 66 13 bpm with p = 0.50 ) and sequence - related temporal resolution was significantly lower in 3d acquisition ( 59 11 ms vs 32 6 ms with p < 0.0001 ) .
however , reporting time was significantly longer for the 3d - cine sequence ( 29 7 min vs 8 3 min with p < 0.05 ) .
intra- and inter - observer variability was within expected ranges ( table 4 ) [ 9 , 20 ] .
table 4intra- and inter - observer variability and the comparison between 2d and 3d k - t blast in terms of global lv volume parameters and reporting time .
parameters are expressed as mean sd ; p value student s paired test ; r value pearson s correlation ; 95% la limits of agreement with bland - altman analysisintra - observerinter - observer3d k - t blast1st analysis2nd analysisp valuer value95% la1st observer2nd observerp valuer value95% laef ( % ) 43 1543 15>0.050.991.75 ; -2.2343 1541 14<0.050.9610.2 ; -6.5ed wall mass ( g)81 2482 24>0.050.993.8 ; -4.181 2488 24<0.050.9310.6 ; -24.3report time ( min)29 729 7>0.050.992.5 ; -2.129 732 7<0.050.893.1 ; -10.22d1st analysis2nd analysis1st observer2nd observeref ( % ) 48 1548 15>0.050.992.3 ; -1.748 1546 14<0.050.969.8 ; -5.9ed wall mass ( g)72 2372 23>0.050.996.8 ; -4.972 2376 23<0.050.9213.9 ; -20.5report time ( min)8 38 2>0.050.902.2 ; -2.78 39 3<0.050.643.2 ; -6.42d vs 3d k - t blast2d3d k - t blast2d3d k - t blast2nd analysis2nd analysis1st observer2nd observeref ( % ) 48 1543 15<0.050.996.56 ; 2.7546 1441 14<0.050.997.9 ; 2.2ed wall mass ( g)72 2382 24<0.050.980.4 ; -20.476 2388 24<0.050.96 - 0.5 ; -24.7report time ( min)8 229 7<0.050.25 - 6.9 ; -34.49 329 7<0.050.16 - 4.8 ; -34.1 intra- and inter - observer variability and the comparison between 2d and 3d k - t blast in terms of global lv volume parameters and reporting time .
parameters are expressed as mean sd ; p value student s paired test ; r value pearson s correlation ; 95% la limits of agreement with bland - altman analysis
mri 2d - cine b - ssfp sequences are considered the reference standard for the assessment of lv volumes and mass .
the idea of a single breath - hold mr sequence is appealing because it may reduce inaccuracies introduced by prolonged multiple breath - holds , such as slice mis - registration , but it requires speeding up image acquisition . in cardiac imaging , acquisition speed has always been of primary importance ; during the past few years several tricks have been used with this aim ; in the beginning , speed improvement was achieved thanks to gradient hardware but a further improvement has been limited by physiological constraints such as peripheral nerve stimulation . thanks to the parallel imaging ( such as sense and smash ) , using information from multiple receiver coils , it has been possible to reconstruct images from a sparsely sampled set of data recovering the missed information by exploiting the differences in signals detected by multiple receiver coils . in clinical practice with parallel imaging , a maximum acceleration factor of two can be achieved , and it is not possible to further increase it without decreasing the signal - to - noise ratio . to further improve the acquisition speed , undersampling techniques , operating in the temporal domain , have been developed , such as k - t blast , which can easily handle a fourfold acceleration factor .
this new approach is based on the fact that image frames are only slightly different if acquired at different time points ; by identifying the redundant information among the image frames , only the novel portions of the images need to be acquired , thus reducing the total amount of sampled information .
we evaluated a recently introduced volumetric sequence ( i.e. 3d k - t blast ) allowing single breath - hold functional assessment of the left ventricle .
however , all measurements of the major cardiac indexes were significantly different ( p < 0.05 ) ; differences may be explained as follows .
first , there are some intrinsic constraints in the software and hardware that do not permit the implementation of a true retrospective gating with 3d - cine sequence on commercially available systems , as extensively explained in a previous technical paper .
we think that even if our sequence parameters were optimally set , we may still not have been able to acquire the correct end - diastolic phase during acquisition and therefore it was not available for image analysis ; this problem is highlighted by the constant underestimation of edv assessed with the 3d - cine sequence compared with the 2d - cine sequence ; this observation is in agreement with previous studies .
this observation may also explain the overestimation of the ed wall mass by the 3d - cine sequence .
lv myocardium may have been evaluated when incompletely relaxed , producing an overestimation of ed wall mass .
the explanation may be related to the lower temporal resolution of 3d - cine , which reduces the accuracy in the selection of the proper end - systolic phase compared with the 2d - cine sequence ; this is in agreement with previous studies exploring the impact of sequences with low temporal resolution . despite significant differences in the absolute values , the over- and under - estimation of lv volumes appeared systematic , resulting in a good correlation between functional parameters .
the mean difference in the calculated ef between 3d - cine and 2d - cine was 5% , with relatively low limits of agreement .
our results suggests that the 3d - cine sequence may be used to obtain useful lv ef measurements in a single breath - hold in patients for whom shorter imaging time is desirable , taking into account both systematic bias and that follow - up studies should be performed with same technique .
anyway , in the future , implementation of a truly retrospectively gated 3d sequence is expected to overcome even the systematic bias encountered . in order to perform a complete lv volumetric quantification ,
the 3d - cine sequence was more time consuming despite the shorter imaging time ; this was because 3d - cine sequences ( 5-mm slice thickness and no gap ) generate more slices to be analysed than 2d - cine sequences ( 8-mm slice thickness and 2-mm slice gap ) .
three - dimensional sequence analysis could benefit from using a 3d analysis tool which permits the valvular and apex contours to be traced in long - axis views to better delineate endo- and epi - cardial borders at these levels ; however , this tool was not yet available in our institute and therefore we did not use it .
three - dimensional sequence analysis could benefit from using a 3d analysis tool which permits the valvular and apex contours to be traced in long - axis views to better delineate endo- and epi - cardial borders at these levels ; however , this tool was not yet available in our institute and therefore we did not use it .
the parameters assessed in the 3d k - t blast cine b - ssfp sequence showed significant difference but excellent correlation and good agreement compared with the current 2d - cine sequence .
this sequence may be an alternative technique for evaluating lv ef in patients for whom shorter imaging times are desirable .
this article is distributed under the terms of the creative commons attribution noncommercial license which permits any noncommercial use , distribution , and reproduction in any medium , provided the original author(s ) and source are credited . | ### Summary:
: objectiveto assess the feasibility of single - breath - hold three - dimensional cine b - ssfp ( balanced steady - state free precession gradient echo ) sequence ( 3d - cine ) , accelerated with k - t blast ( broad - use linear acquisition speed - up technique ) , compared with multiple - breath - hold 2d cine b - ssfp ( 2d - cine ) sequence for assessment of left ventricular ( lv ) function.methodsimaging was performed using 1.5-t mri ( achieva , philips , the netherlands ) in 46 patients with different cardiac diseases .
global functional parameters , lv mass , imaging time and reporting time were evaluated and compared in each patient.resultsfunctional parameters and mass were significantly different in the two sequences [ 3d end - diastolic volume ( edv ) = 129 44 ml vs 2d edv = 134 49 ml ; 3d end - systolic volume ( esv ) = 77 44 ml vs 2d esv = 73 50 ml ; 3d ejection fraction ( ef ) = 43 15% vs 2d ef = 48 15% ; p < 0.05 ] , although an excellent correlation was found for lv ef ( r = 0.99 ) .
bland - altman analysis showed small confidence intervals with no interactions on volumes ( ef limits of agreement = 2.7 ; 7.6 ; mean bias 5% ) .
imaging time was significantly lower for 3d - cine sequence ( 18 1 s vs 95 23 s ; p
< 0.05 ) , although reporting time was significantly longer for the 3d - cine sequence ( 29 7 min vs 8 3 min ; p
< 0.05).conclusionsa 3d - cine sequence can be advocated as an alternative to 2d - cine sequence for lv ef assessment in patients for whom shorter imaging time is desirable . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: fast disintegrating tablets ( fdts ) have received ever - increasing demand during the last decade , and the field has become a rapidly growing area in the pharmaceutical industry .
recent advancements in novel drug delivery system ( ndds ) aim to enhance safety and efficacy of drug molecule by formulating a convenient dosage form for administration in order to achieve better patient compliance .
many patients find it difficult to swallow tablets and hard gelatin capsules that results in high incidence of noncompliance and ineffective therapy [ 1 , 2 ] . fast disintegrating drug delivery systems ( fddds )
are a new generation of formulations which combine the advantages of both liquid and conventional tablet formulations and , at the same time , offer added advantages over both traditional dosage forms .
they provide the convenience of a tablet formulation and also allow the ease of swallowing provided by a liquid formulation .
the concept of fast dissolving / disintegrating tablets emerged from the desire to provide patients with more conventional means of taking their medication when drinking water is not available and in certain cases such as motion sickness , sudden episodes of allergic attacks , or coughing .
recent developments in technology have presented viable dosage alternatives for pediatric , geriatric , bedridden , nauseous , or noncompliant patients .
recent developments in the technology have prompted scientists to develop fdts with improved patient compliance and convenience . upon introduction into the mouth ,
these tablets dissolve or disintegrate in the mouth in the absence of additional water for easy administration of active pharmaceutical ingredients .
fdts are solid unit dosage forms , which disintegrate or dissolve rapidly in the mouth without chewing and water .
fast disintegrating tablets ( fdts ) are also known as fast dissolving , mouth dissolving , quick disintegrating , orally disintegrating ,
orodispersible , melt - in - mouth , quick dissolving , porous tablets and effervescent drug absorption system .
drug dissolution and absorption as well as onset of clinical effect and drug bioavailability may be significantly greater than those observed from conventional dosage forms .
the amount of drug that is subjected to first pass metabolism is reduced as compared to standard tablet .
the target populations for these new fast dissolving / disintegrating dosage forms have generally been pediatric , geriatric , and bedridden or mentally disabled patients .
patients with diarrhea , persistent nausea , or vomiting , who are traveling or who have little or no access to water , are also good candidates for fdts .
formulations of the drugs chosen in combination for the treatment of asthmatic cough and other respiratory disorders are available in the market in conventional tablet and liquid dosage forms .
tablets to be swallowed are resisted by children patients and patient compliance is an issue with such dosage forms .
hence they do not comply with the prescription , which results in high incidence of noncompliance and ineffective therapy .
salbutamol sulphate is a 2 receptor agonist widely used as bronchodilator to relieve acute asthma .
a fast dissolving tablet form would thus be advantageous , as salbutamol sulphate is water soluble and its preparation into a fast dissolving form would render it to dissolve rapidly and thereby result in rapid absorption without any lag time .
cetirizine hydrochloride ( ctz ) is an orally active white , crystalline water soluble drug and selective second generation nonsedative h1-receptor antagonist indicated in upper respiratory allergies , pollinosis , urticaria , and atopic dermatitis and is also used as adjuvant in seasonal asthma . due to sore throat conditions , the patient experiences difficulty in swallowing a tablet type of dosage form .
hence the present investigation was undertaken for preparation of fast disintegrating tablet of salbutamol sulphate , cetirizine hydrochloride in combined dosage form with an aim of improving / enhancing patient convenience and compliance , reducing the lag time , and providing faster onset of action to relieve the respiratory disorders immediately .
salbutamol sulphate and cetirizine hydrochloride were obtained as gift samples from trojan pharma , baddi , india .
microcrystalline cellulose ( avicel ph-102 ) was received as gift sample from nb entrepreneurs , nagpur , india .
sodium starch glycolate ( primojel ) and directly compressible mannitol ( d - mannitol ) were obtained from qualikems fine chem pvt .
sodium saccharin was obtained from loba chemie , mumbai , and talc from nice chemicals private limited , hyderabad , india .
all the chemicals and reagents used in research work were of analytical grade . in the development of
fast disintegrating tablets , the most important parameter that needs to be optimized is the disintegration time . fast disintegrating tablets were prepared firstly using different excipients ( binders and superdisintegrants ) and then evaluated for various parameters like friability , hardness , and disintegration time to select the best combination for formulation of fast disintegrating tablets . the combination with the lowest disintegration time , optimum hardness , and friability was selected for further study .
total six formulations ( f1f6 ) were manufactured to study the effect of type and concentration of superdisintegrants shown in table 1 .
tablets were manufactured by the technique of direct compression . required quantity of each ingredient was taken for each specified formulation .
the superdisintegrant in ( 1% , 2% , 4% , 6% , 8% , and 10% ) concentration was used to develop the tablets .
the mixed blend of excipients was compressed into tablets using 8 mm punch in multipunch tablet compression machine ( dhiman industries , india ) .
total 14 formulations ( f1f14 ) were manufactured to study the effect of type of binder with optimized concentration of superdisintegrants shown in table 2 .
optimized concentration of sodium starch glycolate along with different concentration of binders ( pvp k-30 , mcc ) was used to develop the tablets .
the mixed blend of excipients was compressed into tablets using 8 mm punch in multipunch tablet compression machine ( dhiman industries , india ) . fast disintegrating tablets of salbutamol sulphate ,
cetirizine hydrochloridein combined form were manufactured by direct compression technique , the formula of which is shown in table 3 . required quantity of each ingredient
accurately weighed quantities of salbutamol sulphate , cetirizine hydrochloride taken with optimized concentration of superdisintegrant and binder with excipients were cogrind in geometric progression in a dry and clean mortar .
the mixed blend of excipients was compressed into tablets using 8 mm punch in multipunch tablet compression machine ( dhiman industries , india ) .
weight variation test was done by weighing 20 tablets individually by using digital weighting balance ( ohaus , usa ) .
calculate the average weight and compare the individual tablet weight to the average weight of 20 tablets ( table 4 ) .
the thickness of tablets was measured by placing tablet between two arms of the vernier caliper ( indian caliper industries , ambala , india ) .
the tablet crushing load is the force required to break a tablet into halves by compression .
three tablets from each formulation batch were taken randomly and the average reading was noted .
the friability of the tablets was measured in a roche friabilator ( camp - bell electronics , mumbai ) .
tablets of a known weight ( w0 ) or sample 10 tablets are dedusted in a drum for a fixed time ( 100 revolutions ) and weighed ( w ) again .
percentage friability was calculated from the loss in weight as given in the equation as below .
the weight loss should not be more than 1% :
( 1)percentage friability = initial weightw0final weightwinitial weightw0100 .
the disintegration time of the tablet was measured in water ( 37 2c ) according to using digital tablet disintegration tester ( veego , india ) .
the time in seconds taken for the complete disintegration of the tablet with no palpable mass in the apparatus was measured in seconds .
six tablets from each batch ( formulation ) were tested for the disintegration time calculations .
a piece of tissue paper folded twice was placed in a small petri dish ( id6.5 cm ) containing 6 ml of distilled water being taken .
a tablet containing a small quantity of amaranth color was placed on this being put on the paper and the time for the upper surface of the tablet to become complete red was measured .
ten tablets were powdered and the blend equivalent to 2 mg of salbutamol sulphate and 5 mg of cetirizine hydrochloride was weighed and dissolved in suitable quantity of 6.8 ph phosphate buffer .
the solution was sonicated , filtered , and suitably diluted and the drug content was determined from simultaneous equation method by using double beam uv spectrophotometer ( uv-1800 shimadzu ) at 276 nm and 230 nm wavelengths corresponding to salbutamol sulphate and cetirizine hydrochloride , respectively .
each sample was analyzed in triplicate [ 17 , 18 ] . in vitro dissolution studies for all the fabricated tablets
were carried out using usp eight - stage dissolution testing apparatus-2 ( paddle method ) ( lab , india ) , at 50 rpm in 500 ml of phosphate buffer solution , ph 6.8 at 37 0.5c .
5 ml of aliquot was withdrawn at the specified time intervals , filtered through whatman filter paper and assayed spectrophotometrically at 276 nm and 230 nm .
an equal volume of fresh medium was replaced into the dissolution medium after each sampling , to maintain the constant volume throughout the test .
absorbance of these solutions was measured at their respective max using a double beam uv spectrophotometer ( uv-1800 shimadzu ) .
cumulative percentage ( % ) drug release was calculated from simultaneous equation method which is given as
( 2 ) at 276 nm a1=0.0066cs+0.0050cc,(3 ) at 230 nm a2=0.023cs+0.0338cc ,
where cs is concentration of salbutamol sulphate and cc is concentration of cetirizine hydrochloride . by putting the values of absorbances a1 and a2 at their respective max , the concentrations of salbutamol sulphate and cetirizine hydrochloride were obtained in sample solutions .
ftir spectra of pure drugs and formulated fdt containing drugs were recorded on ftir spectrophotometer ( bruker , usa ) .
this study generally includes ftir spectroscopy and these are generally performed to confirm the drug - excipient compatibility .
ftir spectra of samples were recorded in scanning range of 4000 to 600 cm and the resolution was 1 cm .
ftir scans were then evaluated for shifting and masking and appearance of new peaks due to drug - excipient incompatibility . accelerated stability studies were performed out on formulated fdts ( formulated in three primary batches ) which were wrapped in aluminium foil and then stored in air - tight containers that is impermeable to solid , liquid , and gases , for a period of one month as prescribed by ich guidelines at temperature of 40 2c and at ambient humidity and at room temperature .
the tablets were withdrawn on 15th , 30th day and analyzed for drug content , friability , hardness , and in vitro disintegration time .
an attempt was made in the present investigation to make a fast disintegrating tablet of salbutamol sulphate , cetirizine hydrochloride in combination by direct compression method by employing superdisintegrant such as sodium starch glycolate and mannitol as directly compressible diluent and sodium saccharin was used to enhance palatability .
mcc ( avicel ph 102 ) was used in the formulation as a disintegrant and a binder . to impart pleasant taste and improve mouth feel ,
sodium stearyl fumarate was used as a lubricant because of its water soluble nature and directly compressible features . for optimal bioavailability and rapid absorption ,
the selection of the optimum concentration of superdisintegrant is necessary for rapid disintegration of tablets .
superdisintegrant decreases the disintegration time , resulting in the enhancement of dissolution rate of the drug .
therefore , for the formulation of rapidly disintegrating dosage forms , the proper selection of optimum concentration of superdisintegrant is of vital importance in dosage form development of fdts .
the results for optimization of superdisintegrant concentration in fdts by direct compression method are shown in table 5 . from the evaluation parameters ,
it was observed that 4% sodium starch glycolate was the optimum concentration for rapid tablet disintegration on the basis of the least disintegration time observed with f3 formulation .
the superdisintegrant action of ssg is exhibited by swelling and capillary action which causes rapid disintegration of tablets .
due to its hydrophilic nature , it rapidly absorbs water and swells up to 200300% of their own weight .
disintegration time increases above 8% due to gelling effect of the ssg . to study the effect of binders with the optimized concentration of ssg on the disintegration time , hardness , and friability of tablets , total 14 formulations ( f1f14 ) were prepared using different concentration of polyvinylpyrrolidone ( pvp k-30 ) or microcrystalline cellulose .
it was observed from the evaluation parameters that the disintegration time of the formulation f8 was further decreased and friability and hardness of tablets comply with the ip limits .
the least disintegration time was observed in f8 formulation that is 1% mcc as compared to f2 formulation that is 2% pvp k-30 .
the probable reason was that mcc has porous morphology , due to which water is wicked through the capillary action which causes the tablet to break apart rapidly .
on the other hand , water soluble materials such as pvp k-30 dissolving faster rather than disintegrating .
therefore 1% microcrystalline cellulose was selected as optimum binder concentration selected for final formulation of salbutamol sulphate , cetirizine hydrochloride fdt .
the drug content was found in the range of 85115% of the label claim ( acceptable limit ) and friability of the tablets was found below 1% indicating a good mechanical resistance of tablets .
the in vitro disintegration time ( dt ) of the tablets was found to be less than 60 sec as shown in table 7 . since mechanical integrity is of paramount importance in successful formulation of fdts , hence the hardness of tablets
the formulated fdts had shown low dt indicating suitability of formulation for mouth dissolving tablet . from the in vitro dissolution data
it was observed that 94.70 2.24% of salbutamol sulphatereleased in 10 minutes and 95.59 2.34% of cetirizine hydrochloride released in 16 minutes indicate that the tablet complies as per ip specifications that is 85%110% shown in figure 1 .
the results obtained with ftiir studies showed that there was no interaction between the drug and other excipients used in the formulation .
the ftir spectra of salbutamol sulphate , cetirizine hydrochloride had shown intense absorption band at 1384.70 cm , 1613.03 cm , and 1384.70 cm corresponding to the presence of functional groups such as tri - methyl group , secondary amine group , and phenol group in salbutamol sulphate and at 756.96 cm , 1318.89 cm , 1024.90 cm , and 1191.03 cm corresponding to the presence of functional groups such as aliphatic chloro compound , carboxylic acid , alkyl substituted ether , and tertiary amine in cetirizine hydrochloride .
the ftir of salbutamol sulphate , cetirizine hydrochloride fdt formulation showing intense absorption bands at 1388.28 cm , 1610.83 cm , and 1388.28 cm and at 757.55 cm , 1312.78 cm , 1019.73 cm , and 1194.89 cm indicates no change in the functional groups confirmed undisturbed structure of salbutamol sulphate , cetirizine hydrochloride , which indicates no drug - excipient incompatibility as shown in figures 2 and 3 .
accelerated stability studies were carried out on formulated fdts ( formulated in three primary batches ) as prescribed by ich guidelines , wrapped in aluminium foil to prevent the formulation from exposure to light to simulate the aluminum packaging that is alu alu packing of drug products , and stored in air - tight containers which is impermeable to solid , liquid , and gases , for one - month period .
the result of the stability study indicated that there were not much differences observed in hardness , disintegration time , drug content uniformity , and friability before and after the storage period at room temperature and at ambient humidity but at temperature of 40c 2c and at ambient humidity hardness was increasing with time , prolonging the dt of the tablet ; the probable reason was loss of moisture from tablets but in all cases dt is within the specified ip limit ( within 3 min . ) .
fast disintegrating tablets of salbutamol sulphate , cetirizine hydrochloride in combination were prepared by direct compression method using sodium starch glycolate as a superdisintegrant and commonly available excipient .
the tablets disintegrated rapidly in oral cavity and had acceptable hardness and friability . in vitro drug release from the tablets shows rapid drug dissolution . from the above study
, it was concluded that , by employing commonly available pharmaceutical excipients such as superdisintegrants , hydrophilic and swellable excipients and proper filler , a fast disintegrating tablet of salbutamol sulphate , cetirizine hydrochloride fdt used in respiratory disorders , were formulated successfully with desired characteristics in combined pharmaceutical dosage form which disintegrated rapidly , providing rapid onset of action and enhancing the patient convenience and compliance . | ### Summary:
: the objective of the present study was to prepare the fast disintegrating tablet of salbutamol sulphate , cetirizine hydrochloride in combined tablet dosage form for respiratory disorders such as bronchitis , asthma , and coughing for pediatrics and geriatrics .
the tablets were prepared by direct compression technique .
superdisintegrant such as sodium starch glycolate was optimized as 4% on the basis of least disintegration time .
different binders such as mcc and pvp k-30 were optimized along with optimized superdisintegrant concentration .
1% mcc was selected as optimum binder concentration on the basis of least disintegration time .
the tablets were evaluated for hardness , friability , weight variation , wetting time , disintegration time , and drug content uniformity .
optimized formulation was further evaluated by in vitro dissolution test , drug - excipient compatibility , and accelerated stability study .
percent weight variation and content uniformity were within the acceptable limit .
the friability was less than 1% . the wetting time and disintegration time were practically good for all formulations .
ftir studies and accelerated stability study showed that there was no interaction between the drug and excipients . it was concluded that , by employing commonly available pharmaceutical excipients such as superdisintegrants , hydrophilic and swellable excipients and proper filler , a fast disintegrating tablet of salbutamol sulphate , cetirizine hydrochloride in combined tablet dosage form , were formulated successfully with desired characteristics . |
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: during 20102016 , we collected samples of free - living populations of newts and salamanders from 48 sites in the netherlands , belgium , and adjacent regions of the eifel region in germany ( near the border with the netherlands and belgium ) ( figure ; technical appendix table 1 )
. site selection was based on reported amphibian deaths , apparent negative amphibian population trends , preventive bsal surveillance in susceptible populations , or geographic proximity to known outbreak sites .
samples were also collected at 6 additional sites in germany and 1 in the netherlands , which were located > 100 km from the nearest known outbreak ( technical appendix table 2 ) .
sampling was conducted by swabbing skin ( 7,8 ) of live animals and collecting skin samples from dead animals .
all samples were kept frozen at 20c until they were analyzed for the presence of bsal dna via real - time pcr , as described ( 9 ) .
numbers correspond to field sites at which amphibians were collected and examined for batrachochytrium salamandrivorans ( bsal ) ( technical appendix ) .
note that there are additional sites where the fungus remained undetected ( not shown ) . across all 55 sites
, we tested 1,019 fire salamanders ( 43 dead , 976 skin swab samples ) ; at site 14 , skin swab samples instead of tissue samples were collected from 16 dead salamanders .
we also collected samples from 474 alpine newts ( ichthyosaura alpestris ; 18 dead , 456 skin swab samples ) , 239 smooth newts ( lissotriton vulgaris ; 2 dead , 237 skin swab samples ) , 80 palmate newts ( lissotriton helveticus ; all skin swab samples ) , 79 crested newts ( triturus cristatus ; all skin swab samples ) , and 30 italian crested newts ( triturus carnifex ; all skin swab samples ) . to obtain a bayesian 95% credible interval for prevalence ( online technical appendix )
we ran 3 parallel markov chains with 20,000 iterations each and discarded the first 5,000 iterations as burn - in ; chains were not thinned .
bsal was found at 14 of the 55 sites ; infected amphibians were fire salamanders , alpine newts , and smooth newts .
our results demonstrate that the range of bsal distribution may be up to 10,000 km ( measured as the surface of a minimum convex polygon encompassing the outermost points ) across germany , belgium , and the netherlands ( figure ) .
the presence of bsal in wild alpine newts and smooth newts shows distinct expansion of the known host range in the wild ( technical appendix table 1 ) .
furthermore , we document that bsal is present in natural fire salamander populations in germany ( confined to the eifel region ) . at some sites , because of our sample sizes , the upper limit of the 95% credible interval for bsal prevalence was as high as 0.7 ; therefore , we may have failed to detect bsal at these sites ( technical appendix table 1 ) .
in addition , the fungus may have been present at several sites before first detection .
for example , bsal was detected at site 4 , where population - monitoring efforts in the years before detection ( 20002013 ) showed declines in 4 newt species ( http://www.ravon.nl/eid_si_spitzen_et_al_2016 ) . however , because no samples were collected before 2015 , we have no evidence for a causal relationship between the presence of bsal and the declines .
we have also recorded the presence of bsal in populations with no evidence of population change so far , such as the incidental findings of dead bsal - positive newts in fyke nets at sites 5 and 11 , and the incidental findings of dead bsal - positive fire salamanders at sites 12 and 14 .
clinical signs of mycosis , such as lethargy and skin shedding ( 1 ) , were observed at some bsal - positive sites ( 1 , 2 , 7 , 8 , 14 ) but not at others .
our study provides evidence that bsal among wild amphibians in europe is more widely distributed and affects a wider host range than previously known , which can either indicate recent spread of the fungus or point to historically infected sites that hitherto remained undetected .
the presence of bsal in wild populations can easily remain unnoticed because the lesions develop only near the final stage of the disease ( 1 ) .
our data might be used to inform a management strategy and to implement the recommendation of the bern convention ( 11 ) to halt the spread of bsal in europe .
research to search for molecular evidence that the outbreak locations are connected is under way .
chytrid disease dynamics are affected by multiple factors ( e.g. , temperature regimes ) , and yet undetermined environmental determinants might be essential for disease outbreaks ( 12 ) . untangling these factors , as well as the modes of bsal spread and its geographic distribution , are points for further research to fully map the problem and identify populations and species at risk .
field sites in europe at which batrachochytrium salamandrivorans fungus was and was not detected in amphibians , 20102016 . | ### Summary:
: emerging fungal diseases can drive amphibian species to local extinction . during 20102016 , we examined 1,921 urodeles in 3 european countries .
presence of the chytrid fungus batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity . |
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: polycyclic aromatic hydrocarbons ( pahs )
are ubiquitous environmental
pollutants and suspect human carcinogens .
pahs are products of incomplete combustion and are emitted into
the air we breathe , they are also present in first - hand and second
hand smoke , and many are lung tumorigens in experimental animals .
pahs themselves are biologically inert , and their
carcinogenic effects require metabolic activation to biologically
reactive intermediates , which covalently modify deoxyribonucleic acid
( dna ) , to form dna adducts that result in mutation .
three pathways of metabolic activation of benzo[a]pyrene ( b[a]p ) , a representative pah ,
have been proposed as the formation of radical cations , the formation of anti - diol - epoxides , and the formation of ortho - quinones . in the third pathway ,
benzo[a]pyrene-7,8-dione
( b[a]p-7,8-dione ) , is produced by the oxidation of
( )-b[a]p-7,8-trans - dihydrodiol ,
which is catalyzed by aldo - keto reductases ( akrs ) .
the
electrophilic b[a]p-7,8-dione can undergo 1,4- or
1,6-michael addition with glutathione ( gsh ) , and n - acetyl - l - cysteine ( nac ) in vitro .
it can also react with deoxyguanosine and deoxyadenosine
to form a hydrated n - deoxyguanosine adduct ,
a hydrated cyclic n - deoxyguanosine adduct ,
a hydrated cyclic n - deoxyadenosine adduct ,
or a n7-guanine depurinating adduct in vitro ( figure 1 ) .
b[a]p-7,8-dione
can also be enzymatically and nonenzymatically reduced back to the
catechol and can establish futile redox cycles that result in the
amplification of reactive oxygen species ( ros ) until cellular reducing
equivalents ( e.g. , nadph ) are depleted .
ros formation
can give rise to the mutagenic lesion 8-oxo-2-deoxyguanosine
( 8-oxo - dguo ) in a549 and h358 cells ( figure 1 ) . both the n7-guanine depurinating
adduct and 8-oxo - dguo can give rise to g to t transversions , which
are the dominant mutations found in k - ras and p53 in lung cancer .
human lung cells are major sites
of inhalation exposure to b[a]p , and generation of
the reactive metabolite b[a]p-7,8-dione from b[a]p has been previously
demonstrated in h358 cells .
the downstream metabolism
of b[a]p-7,8-dione in human lung cells has also been
reported . however , to our knowledge ,
information relevant to the formation of stable b[a]p-7,8-dione - dna adducts in any human cell line is lacking .
the objective
of this study was to identify the stable b[a]p-7,8-dione - dna
adducts in human lung cells .
( human lung adenocarcinoma cells ) ,
h358 ( human bronchoalveolar cells ) , and hbec - kt ( immortalized human
bronchial epithelial cells ) were selected as three human lung cell
lines to investigate the comparative profiles of stable b[a]p-7,8-dione - dna adducts .
we found that several stable
b[a]p-7,8-dione - dna
adducts could be detected in a549 and hbec - kt cells . in each case ,
adduct structures were characterized by ms spectra .
we found that a549 cells produced predominately 2-deoxyguanosine
( dguo ) adducts , and hbec - kt cells produced predominately 2-deoxyadenosine
( dade ) adducts .
adduct structures were also compared to those synthesized
from reactions of b[a]p-7,8-dione with dguo , dade
and salmon testis dna in vitro but were found to
be different .
all pahs are potentially
hazardous and should be handled in accordance with the nih guidelines
for the laboratory use of chemical carcinogens .
cell culture medium and reagents
were all obtained from invitrogen co. ( carlsbad , ca ) except for fetal
bovine serum ( fbs ) which was purchased from hyclone ( logan , ut ) .
2-deoxyguanosine ( dguo ) , 2-deoxyadenosine
( dade ) , salmon testis dna , dnase , nuclease p1 , and shrimp alkaline
phosphatase ( sap ) were purchased from sigma - aldrich co. ( st . louis ,
mo ) .
all other chemicals used were of the highest grade available ,
and all solvents were hplc grade .
( human lung adenocarcinoma ) cells
were obtained from american type culture collection ( atcc # ccl-185 )
and maintained in f-12k nutrient mixture ( kaighn s modification )
with 10% heat - inactivated fbs , 2 mm l - glutamine , 100 units / ml
penicillin , and 100 g / ml streptomycin .
( human bronchoalveolar )
cells were obtained from the american type culture collection ( atcc
# crl-5807 ) and maintained in rpmi 1640 nutrient mixture with 10% heat - inactivated
fbs , 2 mm l - glutamine , 100 units / ml penicillin , and 100 g / ml
streptomycin .
hbec - kt ( immortalized human bronchial epithelial ) cells
originated from a patient without lung cancer were a gift from dr .
john minna at university of texas southwestern medical center and
maintained in keratinocyte serum free medium with 0.10.2 ng / ml
recombinant epidermal growth factor ( regf ) , 2030 g / ml
bovine pituitary extract ( bpe ) , and 2 mm l - glutamine .
cells
were incubated at 37 c in a humidified atmosphere containing
5% co2 and were passaged every 3 days at a 1:6 dilution .
cultured cells with a passage number of 1020 were used in
the experiments to reduce variability due to cell culture conditions .
the cells ( 5 10 ) were treated with b[a]p-7,8-dione ( 2 m ,
0.2% dmso ) in hbss buffer containing 1 mm sodium pyruvate as an energy
source .
the cell pellets were collected by scraping at 0 and 24 h.
the dna from the cell pellets was extracted with a wako dna extraction
kit ( wako chemicals usa , inc . , richmond , va ) and was subsequently
dissolved in 300 l of 20 mm phosphate buffer at ph 7.0 .
the solution containing cellular dna ( 300 l ) was subjected
to enzyme hydrolysis .
thirty microliters of 0.1 m mgcl2 and 400 units of dnase was added , followed by 1 h of incubation
at 37 c . a 5 l solution containing 50 mm naoac and 5
mm zncl2 , ph 5.0 , was then added along with 7.5 units of
nuclease p1 .
the sample was incubated for 1.5 h at 37 c . at
the end of the incubation , 40 l of 0.5 m tris - hcl and 50 mm
mgcl2 , ph 8.5 ,
was added along with 20 units of shrimp
alkaline phosphatase ( sap ) , and the sample was incubated for 1.5 h
at 37 c .
ethanol ( 900 l ) was added to the digestion solution ,
and the sample was chilled at 0 c for 10 min .
the sample solution
was centrifuged at 14000 rpm for 10 min at 4 c .
the residue
was redissolved in 100 l methanol plus h2o ( 1:1 )
and analyzed by the ion trap lc - ms / ms .
, rp - hplc showed that the digestion
was complete since only the four deoxyribonucleosides were detected .
data were acquired using a waters alliance 2690 hplc system ( waters
corporation ) coupled to a finnigan ltq spectrometer ( thermo fisher
scientific , san jose , ca ) .
separations were accomplished on a reverse - phase
( rp ) column ( zorbax - ods c18 , 5 m , 4.6 mm 250 mm ) ( dupont
co. , wilmington , de ) with a guard column at ambient temperature . the
mobile phase consisted of 5 mm ammonium acetate and 0.02% formic acid
( v / v ) in h2o ( solvent a ) and acetonitrile ( solvent b ) and
was delivered at a flow rate of 0.5 ml / min .
the linear gradient elution
program was as follows : 20% to 80% b over 40 min , 80% to 95% b over
1 min , followed by an isocratic hold at 95% b for another 4 min . at
45 min , b
was returned to 20% in 1 min , and the column was equilibrated
for 14 min before the next injection .
the total run time for each
analysis was 60 min . during lc - ms / ms analysis , up to 6 min of the
initial flow was diverted away from the mass spectrometer before the
evaluation of eluants .
the mass spectrometer was operated in the positive
ion mode with an electrospray ionization ( esi ) source .
eluants were
monitored on the ltq using product ion scan ( ms ) and subsequent
ms / ms / ms ( ms ) modes . the mass spectrometry parameters ,
including spray voltage ( 4 kv ) , sheath gas flow rate ( 35 arbitrary
units ) , auxiliary gas flow rate ( 18 arbitrary units ) , capillary temperature
( 220 c ) , capillary voltage ( 9 v ) , and tube lens ( 80 v ) , were
automatically optimized with a b[a]p-7,8-dione standard
solution in methanol .
an isolation width of three bracketed around
the m / z of interest , activation
q of 0.25 , and activation time of 30 ms were used for data acquisition .
xcalibur software , version 2.0 ( thermo fisher scientific ) , was used
to control the lc - ms / ms system and to process data .
the b[a]p-7,8-dione - dguo and b[a]p-7,8-dione - dade adducts
were synthesized according to the method reported previously and subsequently analyzed by ion trap lc - ms / ms .
the identity of the hydrated - b[a]p-7,8-dione - n - dguo , hydrated - b[a]p-7,8-dione - cyclic n - dguo and hydrated - b[a]p-7,8-dione - cyclic
n - dade adducts were validated using pseudo - selected reaction
monitoring ( srm ) and ms modes in the same manner as that
described above .
incubations of b[a]p-7,8-dione
with salmon testis dna were performed in a final volume of 0.3 ml
containing 25 g of b[a]p-7,8-dione , 75 g
of salmon testis dna , and 20 mm phosphate buffer at ph 7.0 .
unreacted b[a]p-7,8-dione was removed by repetitive extraction with
cold h2o - saturated ethyl acetate .
the dna pellet was precipitated
from the aqueous layer and was subsequently hydrolyzed by stepwise
addition of dnase , nuclease p1 , and sap .
ethanol was added to the
digestion solution , and the supernatant was dried and subjected to
the analysis by ion trap lc - ms / ms .
the identity of the dna adducts
of b[a]p-7,8-dione were validated using pseudo - selected
reaction monitoring ( srm ) , ms , and subsequent ms modes in the same manner as that described above . at the end of
digestion
, rp - hplc showed that the digestion was complete since only
the four deoxyribonucleosides were detected .
a549 , h358 , and hbec - kt cells were treated
with 2 m b[a]p-7,8-dione to detect and identify
the potential dna adducts using ion trap lc - ms / ms .
previous disposition
studies with radiolabeled 1,3-[h2]-b[a]p-7,8-dione in these three cell lines indicated that there
was incorporation of radioactivity into the cell pellet that reached
a plateau at 6 h and then stayed constant for up to 24 h. subfractionation
of the cell pellet indicated that the radioactivity was in the protein
and dna fractions with the largest portion being covalently bound
to protein .
thus , in our studies we elected
to detect covalent dna adducts following a 24 h treatment with b[a]p-7,8-dione .
the structures of the potential dna
adducts were compared to authentic synthesized standards obtained
by reacting b[a]p-7,8-dione with either deoxyribonucleosides
as described by balu , n. et al . or salmon
testis dna .
the common fragmentation patterns of dguo , dade , and b[a]p-7,8-dione have been reported previously and are shown in figure 2 .
the most generally
characteristic ions in deoxyribonucleoside mass spectra in the positive
ion mode are those representing the base : b ( loss of 117 amu ) , b +
h ( loss of 116 amu ) , and b + 2h ( loss of 115 amu ) . the loss of 115 amu results from the loss
of dr with the abstraction of one hydrogen atom from the sugar to
the base , to yield the aglycone ion .
b[a]p-7,8-dione
can theoretically react with the n1 , n , or n3 positions
of dguo to yield three possible adducts , but addition by the n - exocyclic amino group was expected .
similarly , b[a]p-7,8-dione can theoretically react with the n1 , n3 , or
n positions of dade to yield three possible adducts , but
addition by the n - exocyclic amino group was expected .
although covalent binding at the n7 positions of dguo and dade is
also possible , these reactions would give rise to unstable depurinating
adducts due to the cleavage of the n - glycosidic bond .
on the basis
of these known fragmentation patterns , the ms spectra of potential dna adducts can be interpreted to obtain
more structural information as to their identity .
hydrated - b[a]p-7,8-dione - dguo
adducts were detected in dna digested from a549 cells following treatment
with 2 m b[a]p-7,8-dione for 24 h. two peaks
with retention times of 11.40 and 13.85 min were detected by monitoring
the ms chromatograms ( m / z 566450 ) at 0 h ( figure 3a )
and 24 h ( figure 3b ) .
the corresponding ms spectra ( m / z 566 ) of these
two adducts showed the loss of deoxyribose from the hydrated molecular
ion ( figure 3c ) . the ms spectra
( m / z 566450 ) of
the adduct with a retention time of 11.40 min ( figure 3d ) and the adduct with a retention time of 13.85 min ( figure 3e ) showed reasonable fragmentation patterns from
both the guanine nucleobase and b[a]p-7,8-dione ( loss
of co ) .
in particular , the loss of hnco ( 43 amu ) in figure 3d and nh3 ( 17 amu ) in figure 3e are characteristic of the fragmentation of the
guanine ring . for the adduct with a retention
time of 11.40 min ,
the loss of hnco ( 43 amu ) shown in figure 3d strongly indicates that the covalent binding did
not occur at the n1 position of dguo .
covalent binding at the n3 position
of dguo could also be ruled out since the loss of nh3 ( 17
amu ) was not observed .
thus , michael addition followed by hydration
could account for the formation of the hydrated - b[a]p-7,8-dione - n - dguo adduct with a retention time of 11.40
min as expected .
for the adduct with a retention time of 13.85 min ,
the loss of nh3 ( 17 amu ) shown in figure 3e strongly indicates that the covalent binding did not occur
at the n exocyclic amino group of dguo .
covalent binding
at the n3 position of dguo could also be ruled out since the loss
of hnco ( 43 amu ) was not observed in figure 3e .
thus , michael addition by the enol - imidazole tautomer of guanine
followed by hydration could account for the formation of the hydrated - b[a]p-7,8-dione - n1-dguo adduct with a retention time of 13.85
min .
the specific position by which guanine attacks b[a]p-7,8-dione and the specific position of b[a]p-7,8-dione
hydration could not be ascertained based on mass spectrometry data
only .
on the basis of the known addition chemistry for b[a]p-7,8-dione , it is speculated that
for both adducts guanine addition might occur at the c-10 position
of b[a]p-7,8-dione followed by subsequent hydration
of the quinone as proposed by n. balu et al .
( a ) ms chromatogram at 0 h. ( b )
ms chromatogram at 24 h. ( c ) ms spectrum .
a549 cells ( 5 10 ) were treated
with b[a]p-7,8-dione ( 2 m , 0.2% ( v / v ) dmso )
in hbss buffer containing 1 mm sodium pyruvate .
the cell pellets were
collected at 0 and 24 h. the dna from cell pellets was extracted and
subsequently hydrolyzed before analysis on an ion trap lc - ms / ms .
hydrated - b[a]p-7,8-dione - dade
adducts were detected in dna digested from hbec - kt cells following
treatment with 2 m b[a]p-7,8-dione for 24
h. two peaks with retention times of 9.54 and 11.98 min were detected
by monitoring the ms chromatograms ( m / z 550435 ) at 0 h ( figure 4a ) and 24 h ( figure 4b ) .
the corresponding ms spectra ( m / z 550 ) of these two adducts showed the loss of deoxyribose
from the hydrated molecular ion ( figure 4c ) .
the ms spectra ( m / z 550435 )
of the adduct with a retention time of 9.54 min ( figure 4d ) and the adduct with a retention time of 11.98 min ( figure 4e ) showed reasonable fragmentation patterns from
the adenine nucleobase and b[a]p-7,8-dione ( loss
of co ) . in particular
, the loss of nh3 ( 17 amu ) in figure 4e is characteristic of the fragmentation of the
adenine ring .
the loss of nh3 ( 17 amu ) shown in figure 4e strongly indicates
that the covalent binding did not occur at the n exocyclic
amino group of dade as expected .
thus , michael addition followed by
hydration could account for the formation of the hydrated - b[a]p-7,8-dione - n1- or n3-dade adduct with a retention time
of 11.98 min .
the adduct with a retention time of 9.54 min gave no
fragmentation patterns assignable to adenine in figure 4d , and thus , this adduct could be a hydrated - b[a]p-7,8-dione - n1 , n3 , or n - dade adduct .
the specific position
by which adenine attacks b[a]p-7,8-dione and the
specific position of b[a]p-7,8-dione hydration could
not be ascertained based on mass spectrometry data only . on the basis
of the known addition chemistry for b[a]p-7,8-dione , it is speculated that a 1,4-michael addition
of adenine might occur at the c-10 position of b[a]p-7,8-dione followed by subsequent hydration of the quinone .
( a ) ms chromatogram at 0 h. ( b ) ms chromatogram at 24 h. ( c ) ms spectrum .
hbec - kt cells ( 5 10 ) were treated
with b[a]p-7,8-dione ( 2 m , 0.2% ( v / v ) dmso )
in hbss buffer containing 1 mm sodium pyruvate .
the cell pellets were
collected at 0 and 24 h. the dna from cell pellets was extracted and
subsequently hydrolyzed before analysis on an ion trap lc - ms / ms .
comparison of ms chromatograms
( m / z 532417 ) of
the digested dna from hbec - kt
cells at 0 h ( figure 5a ) and 24 h ( figure 5b ) showed that one peak with a retention time of
18.06 min was a potential b[a]p-7,8-dione - dade adduct .
the corresponding ms spectra ( m / z 532417 ) of this adduct ( figure 5c ) showed reasonable fragmentation patterns from
both b[a]p-7,8-dione ( loss of co ) and adenine . in
particular , the loss of nh3 ( 17 amu ) and hcn ( 27 amu ) in
figure 5c is characteristic of the fragmentation
of the adenine ring .
the loss of nh3 ( 17 amu ) shown in figure 5c strongly
indicates that the covalent binding did not occur at the n position of dade .
thus , michael addition in the absence of hydration
likely accounts for the formation of the b[a]p-7,8-dione - n1-
or n3-dade adduct with a retention time of 18.06 min .
the specific
position by which adenine attacks b[a]p-7,8-dione
could not be ascertained based on mass spectrometry data only . on
the basis of the known addition chemistry for b[a]p-7,8-dione , it is speculated that
a 1,4-michael addition of adenine might occur at the c-10 position
of b[a]p-7,8-dione .
b[a]p-7,8-dione - dade
adducts detected from hbec - kt
cells . ( a ) ms chromatogram at 0 h. ( b ) ms chromatogram
at 24 h. ( c ) ms spectrum at 18.06 min .
hbec - kt cells ( 5
10 ) were treated with b[a]p-7,8-dione
( 2 m , 0.2% ( v / v ) dmso ) in hbss buffer containing 1 mm sodium
pyruvate .
the cell pellets were collected at 0 and 24 h. the dna from
cell pellets was extracted and subsequently hydrolyzed before analysis
on an ion trap lc - ms / ms .
b[a]p-7,8-dione
was reacted with dguo under conditions similar to those previously
published , and three peaks with the retention
time of 17.34 , 17.61 , and 19.69 min were observed corresponding to
the mass transition of a protonated hydrated - b[a]p-7,8-dione - dguo
( m / z 566 ) undergoing the loss of
deoxyribose ( figure s-1a , supporting information ) .
comparison of the fragmentation patterns of these peaks with the
corresponding hydrated - b[a]p-7,8-dione - dguo adducts
reported previously showed a good concordance
( table 1 ) .
the structures of these adducts
were previously confirmed by nuclear magnetic resonance ( nmr ) and are shown in figure s-1a ( supporting information ) .
however , these adducts were different
from stable b[a]p-7,8-dione - dguo adducts detected
in a549 cells based on the retention times ( table 1 ) .
b[a]p-7,8-dione was also reacted with dade under
conditions similar to those previously published , and one peak with a retention time of 18.69 min was observed
corresponding to the mass transition of a protonated hydrated - b[a]p-7,8-dione - dade ( m / z 550 ) undergoing the loss of deoxyribose ( figure s-1b , supporting information ) .
comparison of the fragmentation
patterns of this peak with the corresponding hydrated - b[a]p-7,8-dione - dade adducts reported previously showed a good concordance ( table 1 ) .
the structure of this adduct was previously confirmed by nmr and is shown in figure s-1b ( supporting information ) . however , this adduct was different
from stable b[a]p-7,8-dione - dade adducts detected
in hbec - kt cells based on the retention times ( table 1 ) .
comparison of ms chromatograms
( m / z 566450 ) of
the digested dna obtained from the reaction system of b[a]p-7,8-dione with salmon testis dna at 0 and 24 h showed that one
peak with a retention time of 13.93 min was a potential hydrated - b[a]p-7,8-dione - dguo adduct ( figure s-2 , supporting information ) .
the ms spectra ( m / z 566450 ) of this adduct
showed reasonable fragmentation patterns from both guanine and b[a]p-7,8-dione ( figure s-2 , supporting
information ) .
the loss of nh3 ( 17 amu ) indicates
that the covalent binding did not occur at the n position
of dguo .
the loss of hnco ( 43 amu ) indicates that the covalent binding
did not occur at the n1 position of dguo .
thus , michael addition followed
by hydration could account for the formation of the hydrated - b[a]p-7,8-dione - n3-dguo adduct with a retention time of 13.93
min .
comparison of pseudo - srm chromatograms ( m / z 548432 ) of the digested dna obtained from the
reaction system of b[a]p-7,8-dione with salmon testis
dna at 0 and 24 h showed that one peak with a retention time of 19.11
min was a potential b[a]p-7,8-dione - dguo adduct ( figure
s-3 , supporting information ) .
the specific
position by which guanine attacks b[a]p-7,8-dione
and the specific position of b[a]p-7,8-dione hydration
could not be ascertained based on mass spectrometry data only .
these
dguo adducts were different from stable b[a]p-7,8-dione - dguo
adducts detected in a549 cells based on retention time ( table 1 ) .
comparison of ms chromatograms
( m / z 550435 ) of
the digested dna obtained from the reaction system of b[a]p-7,8-dione with salmon testis dna at 0 and 24 h showed that two
peaks with retention times of 10.29 and 13.79 min were potential hydrated - b[a]p-7,8-dione - dade adducts ( figure s-4 , supporting information ) . the ms spectra ( m / z 550435 ) of these adducts
showed reasonable fragmentation patterns from both adenine and b[a]p-7,8-dione ( figure s-4 , supporting
information ) .
the loss of nh3 ( 17 amu ) indicates
that the covalent binding did not occur at the n position
of dade .
thus , michael addition followed by hydration could account
for the formation of the hydrated - b[a]p-7,8-dione - n1-
or n3-dade adduct with retention times of 10.29 and 13.79 min .
comparison
of pseudo - srm chromatograms ( m / z 532417 ) of the digested dna obtained from the reaction system
of b[a]p-7,8-dione with salmon testis dna at 0 and
24 h showed that one peak with a retention time of 20.54 min was a
potential b[a]p-7,8-dione - dade adduct ( figure s-5 , supporting information ) . the specific position
by which adenine attacks b[a]p-7,8-dione and the
specific position of b[a]p-7,8-dione hydration could
not be ascertained based on mass spectrometry data only .
these dade
adducts were different from stable b[a]p-7,8-dione - dade
adducts detected in hbec - kt cells based on retention time ( table 1 ) .
this study reports the
novel discovery of the stable dna adducts
of b[a]p-7,8-dione in two different human lung cell
lines : a549 and hbec - kt .
b[a]p-7,8-dione is the signature
metabolite of the akr pathway of b[a]p activation
and has been shown to be mutagenic in vitro solely
by generating ros .
the covalent binding
of electrophilic b[a]p-7,8-dione with dna nucleobases
was previously reported in vitro , but there was a failure to detect
these adducts in the a / j mouse lung model of b[a]p
carcinogenesis , when animals were treated with b[a]p , b[a]p-7,8-trans - dihydrodiol ,
or b[a]p-7,8-dione .
this
is the first report of the ability of b[a]p-7,8-dione
to form in vitro stable dna adducts in human lung
cells .
the covalent binding of electrophilic b[a]p metabolites
( e.g. , anti - diol - epoxides or radical cations ) to
dna has been found to be a key step in the initiation of cancer .
formation of dguo adducts or
depurinating adducts from these respective metabolites can lead to
g to t transversions .
formation of stable b[a]p-7,8-dione - dna adducts
leads to a loss of electrophilicity , but the adducts are still capable
of redox - cycling to produce oxidative stress and oxidative dna damage .
identification of the stable b[a]p-7,8-dione - dna
adducts in human lung cells will allow their mutagenicity to be assessed
in lesion bypass assays using site - specifically modified oligonucleotides .
after treatment of a549 , h358 , and hbec - kt cells with radiolabeled
1,3-[h2]-b[a]p-7,8-dione ,
it was found that a small amount of radioactivity was distributed
in the dna extracted from all cell pellets ( data not shown ) , which
is consistent with the previous finding of radioactivity disposition
in isolated rat hepatocytes . among the
three human lung cells , the amount of radioactivity distributed in
the dna extracted from h358 cell pellets was less than the other two
( data not shown ) . in the present study ,
the b[a]p-7,8-dione - dna
adducts were only detected in a549 and hbec - kt cells and not h358
cells , which could be accounted for by a lower formation of b[a]p-7,8-dione - dna adducts in h358 cells .
the b[a]p-7,8-dione - dguo adducts were only detected in a549 cells , whereas
the b[a]p-7,8-dione - dade adducts were only detected
in hbec - kt cells .
we hypothesize that these different dna - adduct profiles
may reflect differences in nucleotide excision repair in the two cell
lines . in the present study ,
a hydrated - b[a]p-7,8-dione - n - dguo adduct was detected in a549 cells .
however , the specific
position by which guanine attacks b[a]p-7,8-dione
and the specific position of b[a]p-7,8-dione hydration
could not be ascertained based on mass spectrometry data only .
it
has been previously reported that the in vitro reaction
of b[a]p-7,8-dione with dguo generated hydrated - b[a]p-7,8-dione - n - dguo , with 1,4-michael addition
occurring at c-10 position of b[a]p-7,8-dione and
hydration occurring across the c-9 and c-10 positions of b[a]p-7,8-dione .
these previous
experiments were replicated to compare the properties of the synthetic
hydrated - b[a]p-7,8-dione - n - dguo adduct
with that formed in a549 cells .
it was found that these two adducts
differed based on retention time . whereas the synthetic hydrated - b[a]p-7,8-dione - n - dguo adduct had a retention
time of 19.69 min , the adduct found in a549 cells was more polar and
gave a retention time of 11.40 min .
one explanation for this discrepancy
is that the specific position of guanine attack to b[a]p-7,8-dione and the specific position of b[a]p-7,8-dione
hydration in a cell - based system are different from those occurring
in the in vitro reaction .
this is the first
time that a hydrated - b[a]p-7,8-dione - n1-dguo
adduct was detected in a549 cells .
michael addition by the enol - imidazole
tautomer of guanine followed by hydration could account for the formation
of this hydrated - b[a]p-7,8-dione - n1-dguo adduct .
however , the specific position of guanine attack to b[a]p-7,8-dione and the specific position of b[a]p-7,8-dione
hydration could not be ascertained based on mass spectrometry data
only .
it has been previously reported that a n1-dguo quinone methide
adduct was observed along with a n - dguo adduct and a n7-guanine
adduct in duplex dna following alkylation with quinone methides .
it was found that the n1-dguo adduct was preferentially formed with
a quinolinyl methide in vitro and that this adduct
is favored thermodynamically . in this instance , the adduct was fully
characterized by 2d - nmr .
b[a]p-7,8-dione-3-mononucleotide adducts
were formed in vitro by reacting b[a]p-7,8-dione with calf thymus dna using [ p]-postlabeling
as the detection method .
when b[a]p-7,8-dione-3-mononucleotide adducts were subjected
to dephosphorylation , they corresponded to b[a]p-7,8-dione - nucleoside
adducts that were formed by reacting b[a]p-7,8-dione
with dguo and dade .
however , not all
of the adducts detected in calf thymus dna could be identified by
comigration with authentic synthetic standards .
we also reported that
a b[a]p-7,8-dione - adenine adduct detected in the
media of human lung cells following b[a]p-7,8-dione
treatment was derived from the cellular nucleotide pool rather than
dna .
we find that none of the stable
b[a]p-7,8-dione - dna adducts detected in a549 and
hbec - kt cells correspond to those previously identified .
these cellular
b[a]p-7,8-dione - dna adducts were different from those
formed with either deoxyribonucleoside or salmon testis dna .
previously , b[a]p-7,8-dione was only found to
be mutagenic in a yeast based system that reported p53 mutations when
redox - cycling conditions were used . in
those experiments ,
reaction of b[a]p-7,8-dione with
p53 cdna in vitro failed to form adducts that were
mutagenic , and subsequent work focused on oxidative dna lesions and
their ability to cause mutation .
it is
likely that any covalent adducts that formed in these experiments
would be similar to those observed in salmon testis dna and differ
from those formed in mammalian cells .
this would suggest that it will
be critical to obtain complete structural information on the cell
based adducts so that their ability to cause mutations can be assessed . in summary , we have identified the stable b[a]p-7,8-dione - dna
adducts in three human lung cells .
the novel findings in this study
are that several stable b[a]p-7,8-dione - dna adducts
were detected in a549 and hbec - kt cells . in a549 cells ,
the structures
of stable b[a]p-7,8-dione - dna adducts were identified
as hydrated - b[a]p-7,8-dione - n - dguo and
hydrated - b[a]p-7,8-dione - n1-dguo . in hbec - kt cells ,
the structures of stable b[a]p-7,8-dione - dna adducts
were identified as hydrated - b[a]p-7,8-dione - dade ,
hydrated - b[a]p-7,8-dione - n1- or n3-dade , and b[a]p-7,8-dione - n1- or n3-dade . in each case , adduct structures
were characterized by ms spectra .
adduct
structures were also compared to those synthesized from reactions
of b[a]p-7,8-dione with either deoxyribonucleosides
or salmon testis dna but were found to be different . | ### Summary:
: metabolic
activation of the proximate carcinogen benzo[a]pyrene-7,8-trans - dihydrodiol ( b[a]p-7,8-trans - dihydrodiol ) by aldo - keto
reductases ( akrs ) leads to b[a]p-7,8-dione that is
both electrophilic and redox - active .
b[a]p-7,8-dione
generates reactive oxygen species resulting in oxidative dna damage
in human lung cells .
however , information on the formation of stable
b[a]p-7,8-dione - dna adducts in these cells is lacking .
we studied stable dna adduct formation of b[a]p-7,8-dione
in human lung adenocarcinoma a549 cells , human bronchoalveolar h358
cells , and immortalized human bronchial epithelial hbec - kt cells .
after treatment with 2 m b[a]p-7,8-dione ,
the cellular dna was extracted from the cell pellets subjected to
enzyme hydrolysis and subsequent analysis by lc - ms / ms .
several stable
dna adducts of b[a]p-7,8-dione were only detected
in a549 and hbec - kt cells .
in a549 cells , the structures of stable
b[a]p-7,8-dione - dna adducts were identified as hydrated - b[a]p-7,8-dione - n2 - 2-deoxyguanosine
and hydrated - b[a]p-7,8-dione - n1 - 2-deoxyguanosine .
in hbec - kt cells ,
the structures of stable b[a]p-7,8-dione - dna
adducts were identified as hydrated - b[a]p-7,8-dione-2-deoxyadenosine ,
hydrated - b[a]p-7,8-dione - n1- or n3 - 2-deoxyadenosine ,
and b[a]p-7,8-dione - n1- or n3 - 2-deoxyadenosine .
in each case , adduct structures were characterized by msn spectra .
adduct structures were also compared to
those synthesized from reactions of b[a]p-7,8-dione
with either deoxyribonucleosides or salmon testis dna in vitro but were found to be different . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: individuals usually have normal appearing hair at birth , which is soon replaced by short , fragile and brittle hair .
hair microscopy shows elliptical nodes of normal thickness separated by abnormal constrictions resulting from defective cortical cell keratinization .
a 32-year - old male presented with decreased hair over the scalp and body since childhood .
examination showed diffuse hair loss with short and brittle hairs over scalp , predominantly over the occipital region [ figure 1 ] .
follicular keratotic papules were seen over the occiput , nape of neck and extensor arms [ figure 3 ] .
light microscopy of hair showed beaded appearance with elliptical nodes separated by narrower internodes thus establishing the diagnosis of monilethrix [ figure 4 ] .
predominant hair loss over occipital region absence of beard and axillary hair multiple follicular keratotic papules over the nape of neck beaded appearance of hair under light microscopy
it was first described by walter smith in 1879 who called it a rare nodose condition of the hair for which radcliffe crocker subsequently suggested the term monilethrix .
the word is derived from monile ( latin ) , which means necklace , and thrix ( greek ) , which means hair indicating the resemblance of the hair to a string of beads or a necklace . hairs usually break at internodal area where cortex is defective and medulla is absent .
the broken hair shafts do not find an easy way out of the infundibulum and they disrupt the outer root sheath .
this gives rise to a kind of foreign body granuloma , a characteristic feature of the red occipital papules .
the alleged occurrence of normal carriers of the dominant gene has not been proven , as a parent with only 5% of abnormal follicles is easily passed as normal . when determining the pattern of inheritance by the examination of relatives , it may be found that people thought to be unaffected transpire to have faint microscopic features , even if only on body hair .
monilethrix has been associated with mutations in three keratin genes located on chromosome 12q13 : hhb1 , hhb3 , and hhb6 .
an autosomal recessive form of monilethrix was found to be caused by mutations in dsg4 while evaluating 12 jewish families from iraq , iran , and morocco , with microscopic findings of monilethrix , but with no evidence of vertical transmission .
there is not yet sufficient information to establish whether these variations are in part consistently correlated with different genotypes .
there is , however , much variation even within the more commonly reported autosomal dominant form .
most commonly the hair is normal at birth and is progressively replaced by beaded and brittle hairs .
patients present with hair loss because of hair fragility that result in 1 - 2 cm long broken hairs . in mild cases the hair loss is localized to the occiput , but in severe cases the eyebrows , eyelashes , pubic , axillary and general body hair may be affected .
some of the broken stubs are observed to be projecting from keratotic follicular papules , especially on the occiput and nape of the neck .
light microscopy of hair shows a beaded appearance because of alternate zones of spindle like thickening and thinning placed about 0.7 - 1 mm apart .
patients may rarely have associated trichorrhexis nodosa , nail and teeth defects , retarded growth , and juvenile cataract .
this case highlights the variable expression as our patient had a severe form of disease in spite of a negative family history , which may be the result of probable occurrence of normal carriers due to involvement of only a small number of hair follicles . | ### Summary:
: monilethrix is a rare autosomal dominant hair shaft disorder with variable expressivity .
it usually presents with short broken scalp hairs and follicular hyperkeratosis .
light microscopy of hair reveals a beaded appearance . here ,
we report the case of a 32-year - old male who presented with sparse hair and follicular keratotic papules in the absence of any family history . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the recent interest in liver fat metabolism has been spurred by the finding that obesity in western societies results in an accumulation of hepatic lipids that , in turn , is associated with the deterioration of insulin signalling [ 13 ] .
the clinical relevance of lipid handling by the liver has been enlightened by the finding that , when rats are starved and subsequently refed , liver lipids rapidly accumulate , especially when fed carbohydrates .
this phenomenon is closely associated to repeated bouts of weight loss and regain , also known as weight cycling or yo - yo dieting .
at the gene expression level , a food deprivation / refeeding regimen using high - carbohydrate diets results in the upregulation of several hepatic lipogenic enzymes such as fatty acid synthetase ( fas ) [ 68 ] and stearoyl - coa desaturase1 ( scd1 ) [ 9 , 10 ] .
although no study has reported the effects of fasting / refeeding high - carbohydrate diets on endocannabinoid receptor 1 and 2 ( cb1 - 2 ) , experimental evidence suggests that hepatic cb receptors contribute to the development of diet - induced hepatic steatosis through the induction of the lipogenic transcription factor srebp1c and its target enzymes ( i.e. , fas ) [ 11 , 12 ] .
simple sugars , abundantly found in fruit drinks , sports drinks , and soda , seem to strongly induce obesity and hepatic steatosis in comparison to complex carbohydrates [ 1315 ] . among simple sugars , fructose is the most potently lipogenic inducer that can increase lipogenesis through activation of srebp1c dependent and independent mechanisms [ 14 , 16 ]
. on the other hand , chronic exercise training affects liver fat metabolism by reducing the accumulation of liver lipids in high - fat fed animals and in humans [ 1719 ] .
although these training adaptations would be compatible with a decrease in long - term fat accumulation , it may represent a disadvantage in an acute situation , such as food deprivation / refeeding a high - fructose diet , in which an increase in hepatic lipogenic activity is necessary to rapidly and adequately buffer the large arrival of substrates .
investigating the role of training on the short - term management of fructose by the liver , in a food - deprived / refed situation , has been limited to the impact of an acute bout of exercise that inhibits key hepatic lipogenic enzymes [ 7 , 8 ] .
proper handling of substrates by the liver may have subsequent implications on plasma tag clearance and fat storage , which , in turn , has implications on inflammation and atherosclerosis development .
by contrast to training , it has been reported that physical inactivity , known to deteriorate muscle insulin signalling , impacts the partitioning of saturated versus unsaturated fatty acids toward storage , resulting in a preferential accumulation of palmitate ( c16 : 0 ) in muscle fat .
physical inactivity also decreases dietary palmitate ( c16 : 0 ) but not oleate ( c18 : 1 ) oxidation , suggesting that the desaturation status of fatty acids is an important factor in determining their fate .
the first purpose of the present study was , therefore , to determine the effects of an 8-week - exercise training program on hfr refeeding - induced lipogenesis by measuring the expression of the lipogenic genes cb1 , cb2 , srebp1c , scd1 , and fatty acid amide hydrolase ( faah ) , an endocannabinoid degrading enzyme known to be involved in liver lipid infiltration [ 11 , 23 , 24 ] .
it is postulated that under the present fasting / refeeding protocol , tr would be associated with an increased hepatic lipogenic activity .
the second objective was to examine the effects of tr on lipid partitioning by measuring fatty acid desaturation index of scd1 activity in liver and plasma expressed under the ratio of monounsaturated to saturated fatty acids ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) in the context of high - fructose refeeding .
female sprague - dawley rats ( charles river , st - constant , pq , canada ) , weighing 180200 g ( 6 weeks of age ) , upon their arrival were housed individually and had ad libitum access to food and tap water ( n = 40 ) .
female rats were used in the present study to avoid the decrease in food intake and body weight that was observed in exercise - trained male rats [ 25 , 26 ] .
their environment was controlled in terms of light ( 12 : 12-h light - dark cycle starting at 6:00 am ) , humidity , and room temperature ( 2023c ) .
this experiment was conducted according to the directives of the canadian council on animal care after the university of montreal ( montreal , pq , canada ) approval .
four days after their arrival , all animals were randomly assigned to a sedentary ( sed ) or an exercise - trained group ( tr ) .
exercise training consisted of continuous running on a motor - driven rodent treadmill ( quinton instruments , seattle , wa ) 5 times / week for 8 weeks .
exercise intensity was progressively increased from 15 min / day at 15 m / min , 0% slope , up to 60 min / day at 26 m / min , 10% slope , for the last 4 weeks of the program . based on previous measurements of oxygen consumption during a progressive exercise test in rats , it was estimated that exercise intensity during the last 4 weeks of the training program occurred at ~65% of maximal oxygen consumption . at the end of this 8-week period
, animals were sacrificed 36 to 48 h after the last exercise session . during the first complete 7 weeks , sed and tr animals had free access to a standard diet ( sd ; 12.5% lipid , 63.2% carbohydrate , and 24.3% protein ; kcal ) consisting of usual pellet rat chow ( agribrands canada , woodstock , on ) . toward the end of the 8th week that corresponded to 4 days prior to sacrifice ,
sed and tr animals fasted for 24 h , refed the sd diet for 24 h , starved for another 24 h , and then refed either the sd or an isoenergetic high - fructose ( hfr ) diet for 24 h. the hfr diet consisted of 13% lipid , 66.8% carbohydrate mainly fructose , and 20.2% protein ( kcal ) .
body weight and food intake were monitored 3 times / week in all rats during the first 7 weeks and every day during the fasting / refeeding stage .
food was removed from the animals ' cage at least 3 h before sacrifice .
after complete anaesthesia ( pentobarbital sodium , 50 mg / kg ip ) , the abdominal cavity was rapidly opened along the median line of the abdomen .
blood was rapidly ( < 45 s ) drawn from the abdominal vena cava ( ~4 ml ) into syringes pretreated with edta ( 15% ) .
thereafter , blood was centrifuged ( 3,000 rpm for 10 min , 4c ) .
the liver median lobe was freeze - clamped and used for mrna , western blot , and lipid analysis .
the mesenteric ( mes ) , urogenital ( ug ) , and retroperitoneal ( rp ) fat deposits were excised and weighed in that order .
mesenteric fat pad consisted of adipose tissue surrounding the gastrointestinal tract from the gastrooesophageal sphincter to the end of the rectum with special care taken in distinguishing and removing pancreatic cells .
urogenital fat pad included adipose tissue surrounding the kidneys , ureters , and bladder in addition to the ovaries , oviducts , and uterus .
retroperitoneal fat pad was taken from the fat deposit behind each kidney along the lumbar muscles
. skeletal muscles ( plantaris , soleus , medial , and lateral gastrocnemius ) of the right limb were removed and weighed thereafter .
total rna was extracted from frozen liver tissue with the use of either trizol ( invitrogen canada inc , burlington , on ) or purelink rna mini kit ( invitrogen , carlsbad , ca ) according to the manufacturer 's protocol .
treated rna was reverse - transcribed into cdna using either the random hexamer primers ( invitrogen ) and reverse transcriptase ( invitrogen ) , or the transcriptor first - strand cdna synthesis kit roche diagnostics , mannheim , germany .
subsequently , we added 2 l cdna to 18 l of a reaction mixture containing sybr green supermix from bio - rad laboratories inc . for scd1 and srebp1c and from roche diagnostics manheim , germany , for cb1 , cb2 , and faah .
as for the previous steps , polymerase chain reaction ( pcr ) was performed in two different pcr machines .
an icycler iq real - time pcr detection system ( bio - rad laboratories , inc .
, hercules , ca ) was used for scd1 and srebp1c , and a roche lighcycler 480 instrument ( roche diagnostics manheim , germany ) served for cb1 , cb2 , and faah mrna quantification .
the gene - specific primers were purchased from invitrogen life technologies inc . and are listed in table 2 .
for scd1 and srebp1c , the thermal cycling program was 95c for 2 min , followed by 40 cycles at 95c for 25 s , at 60c for 25 s , and at 72c for 40 s. for the quantification of cb1 , cb2 , and faah mrna , the following procedure was used .
preincubation lasted 10 min at 95c , followed by 45 cycles of pcr at 95c for 15 s , 60c for 15 s , and 72c for 15 s. following pcr , the melting curve was completed to ensure that only one pcr product was amplified per reaction .
the relative gene expression was calculated as a function of 2 and normalized for -actin transcript level .
the equation used in the calculation was as follows : fold induction = 2 , where ct = the threshold cycle , ( i.e. , the cycle number at which the sample 's relative fluorescence rises above background fluorescence ) and ct = [ ct gene of interest ( unknown sample )
ct -actin ( unknown sample ) ct gene of interest ( calibrator sample )
liver tissue was prepared by homogenization in ripa ( radioimmunoprecipitation assay ) buffer ( 50 nm tris hcl ph8 , 150 nm nacl , 1% np-40 , 0,5% sodium deoxycholate , 0,1% sodium dodecyl sulphate ( sds ) ) and 10 m protease inhibitors ( phenylmethyl sulfonyl fluoride ( pmsf ) , edta , and pepstatin a ) then centrifuged at 10,000 g for 20 min , at 4c . the supernatants were collected , and protein concentrations were determined using bradford assay . then , 30 g of total protein were applied to each well of 12% sds polyacrylamide gel and electrophoresed at 4c for 2 h at 130 v. the resolved protein bands were then transferred onto nitrocellulose membranes ( hybond - c extra ; amersham biosciences ) at 30 v for 120 min , at room temperature .
the blots were blocked overnight at 4c with blocking buffer ( 10% nonfat milk in 10 mmol / l tris , ph 7.5 , 100 mmol / l nacl , 0.1% tween 20 ) .
the blots were incubated for 1 h at room temperature with primary antibody rabbit polyclonal anti - scd1 ( 1 : 2000 ) kindly provided by dr .
juris ozols , then with horseradish peroxidase - labeled donkey antirabbit igg ( 1 : 10000 dilution , amersham biosciences uk ) for 2 hours at room temperature as secondary antibody .
protein loading was normalized for -actin ( sigma monoclonal anti--actin antibody produced in mouse at 1 : 5000 dilution as a primary antibody and horseradish peroxidase - conjugated igg anti - mouse as secondary antibody ) .
finally the blots were visualized using the ecl ( enhanced chemiluminescent , amersham rpn 2132 ) and exposed to autoradiography film ( eugene , st - laurent , qc ) .
samples of 150200 mg frozen liver tissue were homogenized in a saline buffer supplemented with 1% antiprotease ( pmsf , pepstatin , leupeptin ) and 1% antioxidant ( butylated hydroxytoluene , bht ) .
lipid extraction from liver tissue was performed overnight at 4c with the use of a 2 : 1 chloroform - methanol mixture ( vol / vol ) .
then , saline was added and the lower phase was removed into glass vials and dried under a stream of nitrogen .
tubes were immediately stored at 80c for further fatty acid measurements . the method used for fatty acid composition analysis
plasma ( 100 l ) or prepared liver tissue ( described above ) was used for this analysis .
the samples were dissolved in 2 ml methanol - hexane 4 : 1 ( v / v ) mixture containing bht and an internal fatty acid standard ( nonadecanoic acid c19 : 1 ; nu - check prep . inc . , elysian , mn , usa ) . then
samples were hydrolysed at 100c for 60 min , followed by the addition of 5 ml of 6% k2co3 . the upper phase was extracted and then analysed by gas chromatography .
as described by mainieri et al . using the quantitative values of palmitic acid ( c16 : 0 ) , palmitoleic acid ( c16 : 1 ) , stearic acid ( c18 : 0 ) , and oleic acid ( c18 : 1 ) , the desaturation index of scd1 was determined using the product / substrate ratio ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) .
liver tag concentration was estimated from glycerol released after ethanolic koh hydrolysis by a colorimetric method using commercial kits from sigma ( st . louis , missouri , usa ) . although this method does not discriminate between glycerol from phospholipids or tag , frayn and maycock
have shown that omitting removal of phospholipids leads to only a 2% error in the determination of muscle tag .
thus , although a small amount of free glycerol may be produced from hydrolysis of phospholipids , it is considered negligible .
plasma total free fatty acid ( ffa ) concentrations were measured by a colorimetric assay with commercially available kits from roche diagnostics ( penzberg , germany ) .
plasma glucose concentrations were determined with the use of a glucose analyser yellow springs instruments 2300 ( yellow springs , ohio , usa ) .
plasma insulin and leptin concentrations were measured with commercially available radioimmunoassay kits ( linco research , st - charles , missouri , usa ) .
statistical analyses were performed with the use of a two - way anova for nonrepeated measures using training status and diet as main effects .
fisher lsd post hoc test was applied where appropriate , and p values < 0.05 were considered significant .
feeding rats an hfr diet after starvation failed to induce changes in body weight , abdominal adiposity , muscle weight , circulating glucose , insulin , and leptin , even though it decreased energy intake ( p < 0.01 ) ( table 3 ) .
exercise training , however , was associated with a significant increase in energy intake as well as in the sum of 4 muscle weights and with a decrease in intra - abdominal adiposity and in plasma leptin levels under the two diet conditions ( p < 0.05 ) .
hfr compared to sd refeeding resulted in higher ( p < 0.05 ) gene expression of scd1 , srebp1c , and cb1 along with protein content of scd1 ( figure 1 ) .
training , however , had no effect on the expression of any of these molecular markers .
as expected , hfr refeeding resulted in higher liver and plasma tag as well as plasma ffa levels ( figure 2 ) .
although liver tag levels were not affected by training , plasma tag and ffa levels were , respectively , higher ( p < 0.05 ) and lower ( p < 0.01 ) in tr animals refed with the hfr diet .
scd1 fatty acid desaturation indexes ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) in the liver were significantly ( p < 0.01 ) increased exclusively in tr animals refed the hfr diet as a result of a synergetic effect of tr and hfr refeeding ( figures 3(a ) and 3(b ) ) . in plasma , hfr refeeding induced an increase in c16 : 1/c16 : 0 in both sed and tr rats and an increase in c18 : 1/c18 : 0 only in tr rats ( figures 3(c ) and 3(d ) ) .
in an attempt to further understand the role played by regular exercise training on liver fat metabolism and accumulation , we designed the present study to determine if an exercise training program may affect the acute handling of a fructose load by the liver . using a fasting / hfr refeeding approach
, we found that gene expression of hepatic molecular markers of the lipogenesis pathway and as well liver fat accumulation were highly but similarly increased by the hfr refeeding in sed as well as in tr rats .
to go one step further , we measured the ratio of monounsaturated to saturated fatty acids , which is used as a surrogate marker for scd1 activity in liver , thus providing a physiological assessment of the fructose disposal by the liver and fatty acid partitioning [ 14 , 32 ] .
we report for the first time that , following the ingestion of a fructose load , the scd1desaturation indexes were higher in liver ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) and in plasma ( c18 : 1/c18 : 0 ) of tr compared to sed animals .
this finding indicates that training affects the acute handling of a fructose load by providing a higher rate of conversion of de novo synthesized saturated fatty acids to the monounsaturated form .
the hfr refeeding in sed animals did not affect the fatty acids desaturation indexes measured in the liver ( figures 3(a ) and 3(b ) ) .
this indicates that the hfr diet did not result in a change in the ratio of saturated versus monounsaturated fatty acids accumulated in the liver .
however , the c16 : 1/c16 : 0 desaturation index of sed rats refed with the hfr was highly increased in plasma , suggesting an increased liver exportation of the fatty acids under the desaturated form .
several studies have demonstrated that fatty acids originating from different sources appear to be managed differently in the liver with regard to their use for storage or secretion [ 33 , 34 ] .
more specifically , it seems that newly synthesized fatty acids are channelled preferentially into very - low - density lipoproteins for exportation .
plasma tag and ffa plasma levels were accordingly increased by the hfr refeeding in sed rats .
first , liver scd-1 desaturation indexes were highly increased following training without any effects on liver tag levels .
this indicates that although the same quantity of fat was accumulating in liver of sed and tr animals after the hfr refeeding , more of the fatty acids stored in liver of tr rats were under the desaturated form .
this as such provides new evidence that training affect , the acute handling of a fructose load . it might be argued that the increased desaturation ratio in liver of tr rats might be due to a decreased exportation of desaturated fatty acids .
this possibility , however , is not supported by the finding that the c16 : 1/c16 : 0 desaturation ratio in plasma was similar between sed and tr rats and the c18 : 1/c18 : 0
the present data , therefore , support the interpretation that exercise training may influence the acute management of a substrate load such as fructose by changing the partitioning of newly synthesized fatty acids .
supporting this view is the recent report that physical inactivity favours the accumulation of palmitate ( c16 : 0 ) in muscle fat and decreases dietary palmitate but not oleate ( c18 : 1 ) oxidation thus leading to the deterioration of insulin signalling .
the higher levels of fatty acids under the desaturated form in liver of tr rats refed with the hfr load may present some advantages .
recently , li et al . reported that scd1 plays a key role in prevention of steatohepatitis by partitioning excess lipid into monounsaturated fatty acids ( mufas ) that can be safely stored .
this indicates that training favouring the formation of fatty acids that are mostly unsaturated in liver could represent a molecular mechanism of exercise - training - induced metabolic protection in liver .
newly synthesized mufas c16 : 1 and c18 : 1 are the most abundant fatty acids founds in tag molecules . in this
regard , exercise training might favour the conversion of the de novo synthesized fatty acids that are cytotoxic molecules into a form more easily transferrable to tag , known to be biologically inert molecules [ 38 , 39 ] .
exercise training did not , under the present acute dietary manipulations , result in lower levels of liver fat accumulation .
the effects of exercise training in reducing liver fat accumulation under long - term high - fat diets have been reported in several studies [ 17 , 40 ] .
the absence of effects of exercise training on liver fat accumulation in the present study is most likely due to the powerful effect of the hfr load on lipogenesis .
hfr refeeding , whether in sed or tr rats , was associated with an increase in hepatic gene expression of scd1 , srebp1c , and the endocannabinoids cb1 receptors .
it has been reported that the activation of cb1 receptors in liver stimulates de novo lipogenesis through induction of srebp1c and its target enzymes .
recent data in liver - specific cb1 knockout mice indicate that hepatic cb1 receptors are required for the development of diet - induced steatosis by increasing de novo lipogenesis and inhibiting fatty acid oxidation . in agreement with this statement ,
our data show , for the first time , that gene expression of cb1 , and to a lesser extent cb2 , was increased in liver of fasted and fructose refed animals in comparison to those refed the sd diet .
additionally , it has been reported that lipid accumulation in liver may also occur by reduced expression and/or activity of fatty acid amide hydrolase ( faah ) , one of the endocannabinoid degrading enzymes .
the present results , however , do not indicate any effects of the high - fructose diet on the gene expression of the faah enzyme . the fact that scd1 gene expression and protein content in liver were not changed in tr compared to sed rats under the hfr refeeding might at first glance contradict the finding of higher scd1 desaturation indexes measured in the same rats . as stated above , the scd1 index reflects the activity of scd1 .
it is possible that since the hfr load highly stimulated the lipogenesis pathway that the discrimination between the tr and the sed state might be possible only at the activity level . an intriguing observation that needs to be addressed is the fact that several hours after the hfr refeeding , tr rats had higher plasma tag and lower plasma ffa levels than their sed counterparts .
however , since liver tag levels were similar in tr and sed rats , it is unlikely that a difference in vldl synthesis and/or secretion rate is responsible for the higher plasma tag levels found in tr animals . in search of a different explanation
, we must first acknowledge the fact that energy intake was ~30% higher in tr than in sed rats refed the hfr diet . on a speculative basis , it is possible that the lower plasma tag levels found in sed compared to tr rats might be linked to a greater ability of sed rats to store fat in peripheral adipose tissue under the present acute nutritional manipulations .
although the inter - diet comparisons did not reach the statistically significant level , the hfr compared to the sd refeeding seems to have resulted in higher intra - abdominal fat accumulation in sed ( from ~16 to 21 g ) than tr rats ( from 16 to 15.8 g ; table 3 ) . in connection with this ,
higher plasma ffa levels measured in sed compared to tr rats refed the hfr could result from a higher rate of basal lipolysis due to the higher adipocyte fat accumulation . in summary , exercise training is associated with higher liver ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) and plasma ( c18 : 1/c18 : 0 ) scd1 desaturation indexes in rats submitted to a 2-day fast / refeeding protocol using a high - fructose diet in the second day .
gene expression of lipogenic molecular markers including hepatic endocannabinoid receptors , transcription factor srebp1c , and scd1 protein content was increased to a similar in extent in sed and tr rats refed with the hfr diet .
it is concluded that the pattern of management of the hfr load in a fast / refed protocol is modified in exercise trained animals so as to provide more fatty acids under the unsaturated form in liver and plasma .
these data support the contention that exercise training positively modifies the handling of an acute substrate load . | ### Summary:
: the present study was designed to investigate the impact of exercise training on lipogenic gene expression in liver and lipid partitioning following the ingestion of a high fructose load .
female rats were exercise - trained for 8 wk or kept sedentary before being submitted to a fasting / refeeding protocol .
rats were further subdivided as follow : rats were fasted for 24 h , refed a standard diet for 24 h , starved for another 24 h , and refed with a standard or a high - fructose diet 24 h before sacrifice .
fructose refeeding was associated with an increase in hepatic lipid content , endocannabinoid receptor 1 , sterol regulatory element - binding protein1c , and stearoyl - coa desaturase1 gene expression in both sed and tr rats . however , desaturation indexes measured in liver ( c16 : 1/c16 : 0 and c18 : 1/c18 : 0 ) and plasma ( c18 : 1/c18 : 0 ) were higher ( p < 0.01 ) in tr than in sed rats following fructose refeeding .
it is concluded that exercise training does not significantly affect fat accumulation and the molecular expression of genes involved in lipogenesis after fasting and fructose refeeding but does modify the partitioning of lipids so as to provide more unsaturated fatty acids in liver without affecting liver fat content . |
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: neuroplasticity is the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure , function , and connections .
it has been documented that even monozygotic twins may develop differing neural structure and function despite having an identical genetic background .
for instance , some monozygotic twins are discordant for many diseases , such as bulimia nervosa , schizophrenia , and bipolar disorders , and even in sexual orientation [ 36 ] . experiences prior to a cerebral injury may influence not only spontaneous recovery but also the efficacy of post - injury treatment .
thus , we propose that neuroplasticity may play a role in individual differences in the treatment response of neuropsychiatric diseases . since the nervous system monitors and coordinates internal organ function , neuroplasticity may be associated with other diseases .
cardiovascular disease ( cvd ) is associated with depression , and depression is closely related to neuroplasticity .
microrna ( mir ) is receiving intense research interest at present and microrna-132 ( mir-132 ) has roles in neuroplasticity and cardiovascular function . here
, we focus on mir-132 as a common component to discuss the mechanism of coexistence of depression and cvd .
these studies showed that depression is independently associated with cvd and mortality due to causes such as coronary heart disease , heart failure , myocardial infarction , ischemic heart disease , and stroke [ 813 ] .
lifetime association between major depression ( md ) and coronary artery disease ( cad ) was modest ( odds ratio , approximately 1.3 ) .
the effect of md on cad is largely acute , and the longer - term effects are apparently mediated via recurrence of depression .
some studies have demonstrated a significant positive correlation with a moderate effect size of 1.52.7 between depression and cvd .
similarly , several studies have investigated the role of depression status as a prognostic factor in patients with cvd .
meta - analysis of these studies suggests that depressed patients have a 1.62.7-fold increased risk for further cardiovascular events within 24 months .
it is broadly accepted that stress triggers the activation of the hpa axis and causes the brain to be exposed to corticosteroids , affecting neurobehavioral functions with a strong down - regulation of hippocampal neurogenesis , and is a major risk factor for depression [ 1820 ] . chronic or severe stress and high - dose treatment with glucocorticoids decrease hippocampal synaptic plasticity and morphological neuroplasticity .
additionally , chronic restraint stress leads to significant regression of the apical dendrites of pyramidal cells in the medial prefrontal cortex ( mpfc ) and negatively affects mpfc function .
noradrenergic axons have been found with decreased axonal arborization and density after exposure to stress .
accumulating evidence shows that antidepressant treatment may reverse the atrophy of hippocampal neurons , increase cell survival , and increase monoamine axonal sprouting .
brain - derived neurotrophic factor ( bdnf ) signaling , through its tyrosine kinase b ( trkb ) receptor , plays an important role in neuroplasticity .
bdnf has also been shown to be expressed at high levels in the hippocampus and to play an important role in synaptic transmission and in the plasticity of the hippocampus .
bdnf expression is regulated by stress - responsive corticosteroids , and increased glucocorticoid exposure induces a reduction in bdnf level .
chronic stress has been shown to result in alterations in bdnf / trkb signaling and changes in neuronal functions .
serotonergic axon sprouting appears to be dependent on bdnf , which appears to be decreased after stress exposure .
this continued neurogenesis depends on the presence of bdnf and serotonin , both of which are altered in depression , and are inhibited by glucocorticoids .
mirs are short , non - coding , single - stranded rna molecules approximately 1923 nucleotides in length that regulate gene expression by binding to complementary elements in the untranslated regions of target mrnas and inhibiting protein synthesis [ 3335 ] . based on sequence homology
, each mir has the potential to regulate the translation of hundreds of different genes , and greater than 30% of all mammalian genes may be regulated by mirs .
mir-132 , a highly conserved mir transcribed from an intergenic region on human chromosome 17 by the transcription factor camp response element - binding protein ( creb ) , is a key coordinator of the intracellular pathways that mediate experience - dependent changes in the brain [ 3840 ] . using an unbiased genome - wide screen for creb - bound transcripts in vitro , impey et al . identified 16 non - coding mir that are induced by creb - mediated transcription .
further characterization of 1 of these , mir-132 , has recently revealed that it is induced by bdnf and neuronal activity , being demonstrated to affect neuronal characteristics such as neurite outgrowth and cell excitability .
mir-132 is able to modulate dendritic morphology via suppression of a specific target , p250 gtpase - activating protein , and regulate cellular excitability via regulation of ion channels .
interestingly , the creb - dependent mir-132 has been shown to control the development of dendrites and spines , and synaptic integration in cultured hippocampal neurons and newborn hippocampal neurons [ 40,42,4448 ] .
for example , it was reported that knockout of the mir-212/132 locus using conditional transgenic mice or knockdown of mir-132 using viral vectors induced reduced dendritic complexity and spine density , respectively , in newborn neurons of the adult hippocampal neurogenic zone .
a recent study has demonstrated that mir-132 is rapidly transcribed in the hippocampus in vivo following enhanced neuronal activity and contextual fear conditioning .
based on the documented ability of mir-132 to regulate cellular characteristics in an activity - dependent manner , lambert et al .
has provided evidence that overexpression of mir-132 in cultured hippocampal neurons leads to selective changes in short - term synaptic plasticity .
bdnf is essential for a variety of neuronal aspects , including cell differentiation , survival , and synaptic plasticity in the central nervous system ( cns ) .
intriguingly , a recent study suggests that bdnf exerts its beneficial effects on cns neurons via up - regulation of mir-132 .
bdnf increases creb activation ; the creb pathways are among the most critical and are the pathways on which bdnf exerts its effects .
therefore , it is concluded that bdnf affects cns by creb - mir-132 pathway . additionally , increased blood levels of glucocorticoids cause suppression in bdnf - dependent neuronal function via reducing mir-132 expression .
the dysfunction of adult hippocampal neurogenesis is proposed to be an essential mechanism explaining the etiology of depression .
bdnf , creb , and glucocorticoids are the key components for hippocampal neurogenesis , all of which are directly related to mir-132 .
thus , it is suggested that mir-132 plays an important role in the etiology of depression .
the cardiovascular system is controlled by the nervous system , mainly by the autonomic nervous system ; therefore , bdnf can influence the cardiovascular system via the autonomic nervous system .
bdnf is known to play an important role in regulating the survival of neurons in the autonomic nervous system and the formation of their synaptic connectivity with their peripheral targets in the cardiovascular , digestive , and other organ systems .
emerging evidence suggests that bdnf may also affect the function of the autonomic nervous system during adult life and may , in part , mediate the effects of environmental factors , such as exercise and dietary energy intake , on autonomic nervous system neurons and target cells .
bdnf has also been shown to be a modulator of visceral sensory transmission , suggesting that bdnf is involved in maturation and/or plasticity in the arterial baroreceptor pathway .
as noted above , bdnf influences cns via the creb - mir-132 pathway , and most of circulating bdnf is produced in the brain and passes through the blood - brain barrier .
thus , it is suggested that mir-132 may play an important role in cardiovascular function via the autonomic nervous system .
additionally , bdnf may also influence energy homeostasis through its role in neurogenesis and in the neuroplasticity of the hpa axis [ 5557 ] , and is involved in the maintenance of cardiometabolic homeostasis .
therefore , it is suggested that mir-132 may also influence cardiovascular function via the hpa axis .
endothelial dysfunction is a critical step in development of cvd pathology , such as hypertension , atherosclerosis , and thrombosis [ 5961 ] .
the action of vascular endothelial growth factor ( vegf ) is essential to maintain proper endothelial and vascular function .
vegf stimulates virtually all aspects of endothelial function : proliferation , migration , permeability , and nitric oxide production and release .
in addition , the action of vegf makes the endothelium anti - apoptotic . in turn , the inhibition of vegf action is associated with endothelial dysfunction .
research on effects of mir on the endothelium has been conducted , showing that mir-132 is an angiogenic growth factor inducible mir in the endothelium .
mir-132 downregulates p120 ras gtpase - activating protein , thereby removing the endogenous brake on ras activity and activating quiescent endothelium .
mir-132 mediates the deleterious effect of angiotensin ii in vascular smooth muscle cells . however , endothelial dysfunction is the first step to cvd and plays a central role in its pathogenesis .
additionally , mir-132 may have an important role in cardiovascular function via the autonomic nervous system and the hpa axis .
bdnf also maintains vessel stability in the heart through direct angiogenic actions on endothelial cells .
although at present there is no literature on the role of mir-132 in bdnf - induced angiogenesis , it is likely that creb and mir-132 , which are the common components in bdnf - induced neuroplasticity and vegf - induced angiogenesis , are involved in the mechanism .
thus , the positive effect of mir-132 on the cardiovascular system may be greater than the negative one . for example , katare et al
. investigated the therapeutic activity and mechanistic targets of saphenous vein - derived pericyte progenitor cells ( svps ) in a mouse myocardial infarction model and concluded that svp transplantation produces long - term improvement of cardiac function by a novel paracrine mechanism involving the secretion of mir-132 and inhibition of its target genes .
furthermore , a study of long - term -adrenergic administration on the expression levels of the cardiac l - type ca channel 2 subunit , which regulates channel trafficking and function , showed that cardiac l - type ca channel 2 subunit protein expression may be down - regulated by mirs , including mir-132 , in response to long - term activation of -adrenergic signaling , possibly as an adaptive response in cardiac hypertrophy and sustained -adrenergic states .
low bdnf level reduces creb activation , resulting in down - regulation of mir-132 , and then disrupts neuroplasticity and leads to depression .
stress also increases the level of glucocorticoid , and increased glucocorticoid level also down - regulates mir-132 .
circulating bdnf , most of which is produced in the brain and passes through the blood
in addition , mirs are also found in microvesicles , which are plasma membrane fragments shed from virtually all cells .
microvesicles circulate in peripheral blood , where they transport mrna and proteins between cells and play a pivotal role in cell - to - cell communication .
recent studies also raise the possibility that cns - derived vesicles may enter the bloodstream and interact with endothelial cells in the peripheral circulation , suggesting that the synthesis of mir-132 in the brain may be related to mir-132 level in the cardiovascular system .
thus , we hypothesize that mir-132 may play a role in coexistence of depression and cvd .
figure 1 presents an integrative model that shows the possible role of mir-132 in coexistence of depression and cvd .
this model is not intended to be complete or all - encompassing , but rather to highlight and connect certain interesting evidence pointing to this mir-132 role .
based on this hypothesis , mir-132 may be a potential target for treating depression and cvd .
both depression and cvd may benefit from up - regulated mir-132 , and more research should be conducted in this field . | ### Summary:
: different individuals have different degrees of neuroplasticity due to their different experiences .
neuroplasticity may play a role in individual differences among neuropsychiatric disease treatment efficacy . since the nervous system monitors and coordinates internal organ function , neuroplasticity may be associated with other diseases .
cardiovascular disease ( cvd ) is associated with depression , which is a disorder of disrupted neuroplasticity .
microrna-132 ( mir-132 ) has a roles in neuroplasticity and cardiovascular function .
thus , we hypothesize that mir-132 may play a role in coexistence of depression and cvd . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: unequivocal characterization of the biosorption and bioaccumulation processes of radionuclides and heavy metals by macroalgal species under environmental conditions is a difficult task because of the complexity of the processes per se , as well as due to the numerous influencing factors [ 57 , 23 ] .
the understanding of the mechanisms and the mathematical characterization of the bioaccumulation processes of radionuclides and heavy metals by aquatic plants would assist the development of variable applications of this ability in environmental contexts [ 4 , 6 , 7 , 21 , 22 ] .
studies conducted on the bioaccumulation process of cs and other radionuclides and heavy metals in marine plants have pointed to their considerable bioaccumulation ability irrespective of the area of the study : in the black sea [ 1618 , 20 ] , agean sea [ 1 , 1113 ] , new caledonia lagoon , northern pacific the aleutian chain , mediterranean sea .
macroalgae are used mainly as bioindicators in environmental status assessments regarding contamination with hazardous substances , including heavy metals and radionuclides [ 2 , 3 , 8 , 15 , 20 ] .
the main properties that are determinant in the wide application of aquatic plants as bioindicators are their common occurrence and relatively facile accessibility .
an important factor is the exchange method of elements with the environment the foliar uptake in the case of plants with the exclusion of the gastric tract , which makes the resultant interpretation difficult in the case of fauna .
the foliar uptake also determines the fact that the contaminant concentrations detected in the plant tissue directly reflect changes occurring in the environment .
therefore , the response time to environmental changes is much shortened also because the intensive physiological processes and growth of the macroalgae takes place in a relatively short period of the year and thus are followed by increased uptake and quick response to contamination .
studies on macroalgae bioaccumulation and bioindication processes carried out in the baltic sea area [ 14 , 19 , 26 , 2830 ] have indicated that taking into account plant morphology , e.g. comparing green algae , red algae , brown algae and vascular plants , the key element in bioaccumulation efficiency is the construction of the thallus .
filamentous algae or plants with an expanded exterior , which facilitates the exchange of elements with the environment , are at an advantage .
polysiphonia fucoides , a red algae , proved to be one of the best accumulating plants and contained the highest activity concentrations of cs in consecutive years , and the highest concentration coefficient values [ 26 , 28 , 29 ] .
the primary goal of the presented study was the determination of the abilities of p. fucoides to accumulate cesium isotopes , which are still of considerable concern within the baltic sea area because of the increased level of cs .
the bioaccumulative abilities were also examined towards a mixture of gamma emitting isotopes ( mn , co , zn , cd , ag , sn , cs and am ) , some of which are released from nuclear power plants in routine operational procedures .
the appropriate designation of experiments carried out in 2010 and in 2011 made it possible to follow the bioaccumulation process via changes in isotope activities in the plant tissue and seawater medium .
the experiment with a single isotope exposure followed by one with a mixture of radioactive elements indicated the effect of competitive isotope accumulation on that of cesium ions .
the bioaccumulation process of gamma emitting radionuclides was examined in the red algae p. fucoides under laboratory conditions in two separate experiments carried out in 2010 and 2011 .
macrophytes were sampled in the area of kpa redowska , in the gulf of gdask ( fig . 1 ) .
the plants were collected with the stony substrate by scuba divers on 5th october 2010 and on 28th april 2011 .
the stones covered with red macroalgae were rinsed with seawater , in order to remove sand , solid pollutants and organisms ( e.g. gammarus spp . ) living in the thalli .
the plants were immersed in aquariums of 50 80 50 cm dimensions , equipped with aerating filters .
water temperature was adjusted to ambient temperature and was 20 1 c , while water salinity was about 7.0 ( pss78).fig .
1sampling location in 2010 , the plants were placed in three aquariums and left to equilibrate for 1 day . on the next day ( 6th october 2010 ) , 1 and 2 ml of standard cs solution ( code jm/25/o/00 , activity 21 bq g/09.11.2000 ; produced by the obri polatom , poland ) were added to two of the aquariums , a1 and a2 respectively . to the third aquarium ( a3 ) , 2 ml of standard cs solution ( code bw / z-63/14/10 , total activity 1.37 0.02 kbq g/01.05.2010 , total weight 10.14714 g ; produced by the obri polatom , poland ) was added .
because of the intensive mixing of water in the aquariums by pressurized air , the isotope concentrations homogenized immediately . at this point , samples for the determination of initial isotope concentrations were taken . in 2011 ,
the plants were placed in one aquarium only and left to equilibrate for 2 days . on the third day
( 30th april 2011 ) , 1 ml of mix gamma standard solution ( code bw / z-62/27/09 , total activity 72.67 kbq/15.06.2009 , total weight 10.02732 g ; produced by the obri polatom , poland ) was added to the aquarium .
the standard solution contained a mixture of 11 radionuclides ( cr , mn , co , co , zn , sr , cd , ag , sn , cs , am ) .
the initial concentrations of radionuclides in the spiked seawater were calculated using certificated values and seawater volume .
the sampling of plant material was done in the same manner on both experimental occasions , in 2010 and 2011 .
the first sampling was done 1 day after the spiking , and the subsequent samplings were done every day until the fifth day of the experiment , and then every 3 days . in 2010 , in the experiment on cs and cs concentration changes , seawater samples from the aquariums were collected in parallel to plant tissue .
relatively high isotope concentrations in the aquariums made it possible to collect samples of very small volume30 ml , therefore the conditions of the experiment were considered constant .
water samples were collected at the same temporal intervals as the plant material every day on the first 5 days of the experiment and later every 3 days . in the case of the experiment carried out in 2011 ,
the concentrations of gamma emitting isotopes were below their detection limits in samples of 30 ml volume .
the removal of samples of bigger volume ( e.g. 450 ml ) , after the initial one , could not be continued as it caused considerable loss of seawater from the aquarium .
initial environmental concentrations of radionuclides were determined in p. fucoides in specially designated samples collected at the same time as the plants for the exposure experiment .
the concentrations of all analyzed radionuclides in environmental plant samples , except for cs , were below their detection limits .
the limit of detection values ( expressed in bq kg dw ) of the analyzed radionuclides in algae tissue were as follows : cr64.6 , mn7.3 , co4.8 , co7.9 , zn15.2 , sr7.9 , cd93.0 , ag6.1 , sn7.6 , cs6.8 and am22.8 .
seawater samples of 450 ml volume were taken in situ parallel to the plants samples and radionuclide concentrations were measured in marinelli geometry with the same gamma spectrometric method .
most radionuclide activities in environmental seawater were below their detection limits of cr0.82 ; mn0.08 ; co0.09 ; co0.11 ; zn0.15 ; sr0.9 ; cd2.04 ; ag0.13 ; sn0.13 ; cs0.07 ; am0.28 bq dm . the environmental concentrations of cs in seawater were determined from monitoring data ascs is measured regularly in the seawater of the polish sector of the baltic sea every year since 1984 . because cesium activity concentrations are quite uniform in the water column , the environmental concentrations were determined as a mean from the results of measurements at two stations in the gulf of gdask p110 and p116 ( fig .
1 ) in 2010 and in 2011 . the macroalgae samples taken from the aquariums were dried and weighed to determine dry mass content , ashed at 450 c and homogenized .
then , they were placed in cylindrical dishes of 40 mm diameter , and in such a form they were ready for radioactivity measurements .
the activity of seawater samples of 30 ml volume was measured in vessels of the same geometry as used for plant tissue .
the measurement of gamma emitting radionuclide activity was carried out with the gamma spectrometric method , using two spectrometric systems : an hpge detector , with a relative efficiency of 18 % and a resolution of 1.8 kev for a peak of 1,332 kev of co and an hpge detector , with a relative efficiency of 40 % and a resolution of 1.8 kev for a peak of 1,332 kev of co. the detectors were coupled to an 8,192-channel computer analyzer .
the analyses of radioactivity spectra , registered in 8,000 channels , was carried out by the genie-2000 software .
the measurement calibration was done using a gamma standard solutions mix produced by the obri polatom , poland ( code bw / z-62/27/07 ) .
the reliability and accuracy of the applied method was verified by participation in the helcom
mors proficiency test determination of radionuclides in fish flesh samples , organized by iaea - mel monaco ( iaea-414 , irish and north sea fish ) .
fish muscle material may be recognized as a substitute for the ashed macroalgae samples because of nearly the same density of the prepared samples .
the results of cs and k determination in the test material are presented in table 1 after iaea report .table
mors proficiency test determination of radionuclides in fish flesh ( iaea 414certified reference material)analyteiaea value ( bq kg dw)iaea uncertainty ( bq kg dw)laboratory value ( bq kg dw)laboratory uncertainty ( bq kg dw)laboratory uncertainty ( % ) accuracy ( % ) precision ( % )
k48116474.519.34.11.355.2
cs5.180.105.060.6412.62.3212.8laboratory no .
4 , institute of meteorology and water management , maritime branch , gdynia , poland , reference date : 01 january 1997 modified after results of helcom mors proficiency test determination of radionuclides in fish flesh ( iaea 414certified reference material ) laboratory no .
4 , institute of meteorology and water management , maritime branch , gdynia , poland , reference date : 01 january 1997 modified after
the bioaccumulation process of gamma emitting radionuclides was examined in the red algae p. fucoides under laboratory conditions in two separate experiments carried out in 2010 and 2011 .
macrophytes were sampled in the area of kpa redowska , in the gulf of gdask ( fig . 1 ) .
the plants were collected with the stony substrate by scuba divers on 5th october 2010 and on 28th april 2011 .
the stones covered with red macroalgae were rinsed with seawater , in order to remove sand , solid pollutants and organisms ( e.g. gammarus spp . ) living in the thalli .
the plants were immersed in aquariums of 50 80 50 cm dimensions , equipped with aerating filters .
water temperature was adjusted to ambient temperature and was 20 1 c , while water salinity was about 7.0 ( pss78).fig .
1sampling location in 2010 , the plants were placed in three aquariums and left to equilibrate for 1 day . on the next day ( 6th october 2010 ) , 1 and 2 ml of standard cs solution ( code jm/25/o/00 , activity 21 bq g/09.11.2000 ; produced by the obri polatom , poland ) were added to two of the aquariums , a1 and a2 respectively . to the third aquarium ( a3 ) , 2 ml of standard cs solution ( code bw / z-63/14/10 , total activity 1.37 0.02 kbq g/01.05.2010 , total weight 10.14714 g ; produced by the obri polatom , poland ) was added .
because of the intensive mixing of water in the aquariums by pressurized air , the isotope concentrations homogenized immediately . at this point , samples for the determination of initial isotope concentrations were taken . in 2011 ,
the plants were placed in one aquarium only and left to equilibrate for 2 days . on the third day
( 30th april 2011 ) , 1 ml of mix gamma standard solution ( code bw / z-62/27/09 , total activity 72.67 kbq/15.06.2009 , total weight 10.02732 g ; produced by the obri polatom , poland ) was added to the aquarium .
the standard solution contained a mixture of 11 radionuclides ( cr , mn , co , co , zn , sr , cd , ag , sn , cs , am ) .
the initial concentrations of radionuclides in the spiked seawater were calculated using certificated values and seawater volume .
the sampling of plant material was done in the same manner on both experimental occasions , in 2010 and 2011 .
the first sampling was done 1 day after the spiking , and the subsequent samplings were done every day until the fifth day of the experiment , and then every 3 days . in 2010 , in the experiment on cs and cs concentration changes , seawater samples from the aquariums were collected in parallel to plant tissue .
relatively high isotope concentrations in the aquariums made it possible to collect samples of very small volume30 ml , therefore the conditions of the experiment were considered constant .
water samples were collected at the same temporal intervals as the plant material every day on the first 5 days of the experiment and later every 3 days . in the case of the experiment carried out in 2011 ,
the concentrations of gamma emitting isotopes were below their detection limits in samples of 30 ml volume .
the removal of samples of bigger volume ( e.g. 450 ml ) , after the initial one , could not be continued as it caused considerable loss of seawater from the aquarium .
initial environmental concentrations of radionuclides were determined in p. fucoides in specially designated samples collected at the same time as the plants for the exposure experiment .
the concentrations of all analyzed radionuclides in environmental plant samples , except for cs , were below their detection limits .
the limit of detection values ( expressed in bq kg dw ) of the analyzed radionuclides in algae tissue were as follows : cr64.6 , mn7.3 , co4.8 , co7.9 , zn15.2 , sr7.9 , cd93.0 , ag6.1 , sn7.6 , cs6.8 and am22.8 .
seawater samples of 450 ml volume were taken in situ parallel to the plants samples and radionuclide concentrations were measured in marinelli geometry with the same gamma spectrometric method .
most radionuclide activities in environmental seawater were below their detection limits of cr0.82 ; mn0.08 ; co0.09 ; co0.11 ; zn0.15 ; sr0.9 ; cd2.04 ; ag0.13 ; sn0.13 ; cs0.07 ; am0.28 bq dm . the environmental concentrations of cs in seawater were determined from monitoring data ascs is measured regularly in the seawater of the polish sector of the baltic sea every year since 1984 . because cesium activity concentrations are quite uniform in the water column , the environmental concentrations were determined as a mean from the results of measurements at two stations in the gulf of gdask p110 and p116 ( fig .
the macroalgae samples taken from the aquariums were dried and weighed to determine dry mass content , ashed at 450 c and homogenized .
then , they were placed in cylindrical dishes of 40 mm diameter , and in such a form they were ready for radioactivity measurements .
the activity of seawater samples of 30 ml volume was measured in vessels of the same geometry as used for plant tissue .
the measurement of gamma emitting radionuclide activity was carried out with the gamma spectrometric method , using two spectrometric systems : an hpge detector , with a relative efficiency of 18 % and a resolution of 1.8 kev for a peak of 1,332 kev of co and an hpge detector , with a relative efficiency of 40 % and a resolution of 1.8 kev for a peak of 1,332 kev of co. the detectors were coupled to an 8,192-channel computer analyzer .
the analyses of radioactivity spectra , registered in 8,000 channels , was carried out by the genie-2000 software .
the measurement calibration was done using a gamma standard solutions mix produced by the obri polatom , poland ( code bw / z-62/27/07 ) .
the reliability and accuracy of the applied method was verified by participation in the helcom
mors proficiency test determination of radionuclides in fish flesh samples , organized by iaea - mel monaco ( iaea-414 , irish and north sea fish ) .
fish muscle material may be recognized as a substitute for the ashed macroalgae samples because of nearly the same density of the prepared samples .
the results of cs and k determination in the test material are presented in table 1 after iaea report .table
mors proficiency test determination of radionuclides in fish flesh ( iaea 414certified reference material)analyteiaea value ( bq kg dw)iaea uncertainty ( bq kg dw)laboratory value ( bq kg dw)laboratory uncertainty ( bq kg dw)laboratory uncertainty ( % ) accuracy ( % ) precision ( % )
k48116474.519.34.11.355.2
cs5.180.105.060.6412.62.3212.8laboratory no .
4 , institute of meteorology and water management , maritime branch , gdynia , poland , reference date : 01 january 1997 modified after results of helcom mors proficiency test determination of radionuclides in fish flesh ( iaea 414certified reference material ) laboratory no .
4 , institute of meteorology and water management , maritime branch , gdynia , poland , reference date : 01 january 1997 modified after
the maximal increase of cs and cs activity in p. fucoides was observed after the first day of exposure , independent of the initial radionuclide concentration in the medium ( fig . 2 ) .
the initial concentration of cs ( 137-ceasium ) in seawater was 4.49 0.13 bq dm in aquarium a1 and 8.75 0.18 bq dm in aquarium a2 , while that of cs in aquarium a3 was 51.3 0.3 bq dm .
hence , the lowest experimental concentration of cs ( in a1 ) was already 160 times higher than the environmental concentration , 28.0 0.8 bq m , determined in monitoring measurements in the gulf of gdask.fig .
2changes of cs and cs activities in p. fucoides and seawater with exposure time changes of cs and cs activities in p. fucoides and seawater with exposure time activity concentrations of cs in p. fucoides reached 465.0 32.2 bq kg dw ( dry weight ) and 623.8 22.8 bq kgdw in aquariums a1 and a2 , respectively .
activity concentration of cs in p. fucoides in aquarium a3 reached 5,381 47 bq kg dw .
the initial extremely intensive increase of radioactivity was probably related to the uptake of the radionuclides from the medium , occurring spontaneously and independently of metabolism and requiring no energy input
. then other mechanisms of adsorption and transportation , both passive and active , may play a more important role .
to be adsorbed , each ion has to pass barriers such as the laminar layer , the cell wall and the plasmalemma , before finally reaching the cytoplasm .
the thickness of the laminar layer depends on the turbulence occurring in the surrounding water . under laboratory conditions , due to aeration
, the effect of this layer can probably be excluded and the uptake will not be limited by the rate of diffusion across this layer . generally , during the first stage , ions are introduced to the so - called apparent free space that , in seaweeds , includes the cell wall and all intercellular spaces exterior to the plasmalemma .
the apparent free space consists of two parts ; the first of these is called the water free space and the second one , which relates to the deeper parts of the thallus , is the donnan free space .
this mechanism is likely to explain the oscillations in isotope activities observed in the first 5 days of exposure ion transport in both directions until the equilibrium is reached in the system .
the increase in isotope concentrations in the plant tissue on the 8th day of exposure , i.e. after the quasi - equilibrium was reached , could indicate an increase in the contribution of the active transport mechanism in the bioaccumulation process , the mechanism mainly linked to the plant metabolism .
the bioaccumulation process at this stage is much less intensive because the plasmalemma might be much more difficult to penetrate unlike the cell wall which does not generally present a barrier to ion entry .
the development of isotope activity changes in a seawater medium , illustrated by the curves in ( fig .
2 ) , and is well reflected in the changes occurring in the plant tissue .
the significant decrease in isotope activity concentrations took place during the first 5 days of exposure and , after the 8th day , the concentrations changed very little ( fig . 2 ) .
the concentration process of the ions in plant tissue is related to the dynamic steady state between the uptake and excretion processes .
the concentration factor ( cf ) is the quantitative measure that allows us to assess the relative ability of biota representatives to absorb and/or take up the analyzed trace element . to follow the progress in bioaccumulation process , temporary concentration factors ( tcf )
the tcf of cesium isotopes were increasing over the entire experiment period ; in the case of cs from 114 to 275 dm kg in the aquarium a1 and from 93 to 207 dm kgin the aquarium a2 .
the range of tcf in the case of cs was 144351 dm kg .
3 ) ; r = 0.937 ( p = 0.0006 ) in a1 aquarium , r = 0.922 ( p = 0.0001 ) in a2 aquarium and r = 0.976 ( p
3changes of tcf with exposure time changes of tcf with exposure time the slope of the line , corresponding to the tcf daily increment ( tcf ) , can be considered a rate of isotope bioaccumulation by p. fucoides .
the calculated tcf results were quite close in the case of cs in aquarium a1 ( 8.5 dm kg day ) and cs in aquarium a3 ( 7.7 dm kg day ) .
a slightly lower rate , 5.5 dm kg day , was obtained in a2 aquarium for cs . because the substantial change in activity was observed on the first day of exposure , initial concentration factors ( cf0 )
were determined to compare bioaccumulation efficiency of p. fucoides towards a single isotope in this decisive stage of experiment ; the cf0 was defined as the ratio of the isotope concentration in the plant tissue after the first day of exposure to its initial concentration in the seawater medium . in the case of cesium isotopes
cs ( in aquarium a1 ) and cs ( in aquarium a3)cf0 values were nearly identical : 104 7 and 105 1 dm kg .
this provided evidence that the cf0 did not depend on the initial isotope concentration in the seawater medium .
the bioaccumulation process of cs in a2 aquarium showed slightly different characteristics ; the cf0 = 71 6 dm
kg was much lower than in a1 and a3 , and the changes of tcf in consecutive days varied resulting in a lower daily tcf .
the observed discrepancies indicate a different experimental regime , e.g. a much bigger plant biomass in the aquarium a2 .
the experiment on the bioaccumulation of a mixture of gamma emitting radioisotopes by p. fucoides under laboratory conditions showed a statistically significant linear relation ( r = 0.977 , p = 0.0003 ) of the activity of isotopes in the plant tissue and their initial concentration in a seawater medium after the first day of exposure ( fig . 4 ; table 2 ) .
cs was an exception as its activity in p. fucoides was definitely lower than would be expected from the linear relationship .
at the same time the concentration of cesium in the plant tissue was increasing proportionally to the concentrations in seawater ( fig . 4 ) .
the efficiency of cesium bioaccumulation was nearly eight times lower at the stage than in the case of other radioisotopes , well illustrated by the low slope of the correlation curve ( fig .
this low bioaccumulation efficiency at the initial stage was also marked in the low values of initial concentration coefficients cf0 . in the case of cs , cf0 = 135 7 dm
however , in the experiment in 2011 , the concentration coefficient determined at the equilibrium stage reached 1,547 69 dm kg , i.e. it was over 100 times higher .
the cf0 characterizing the remaining isotopes were varying in a relatively narrow range 862949 dm kg in the case of mn , co , co , cd and ag ( fig . 5 ) .
zn was marked for the highest cf0 = 1,125 57 dm kg.fig .
4relation of radionuclides activities in p. fucoides to the initial activities in seawatertable 2parameters characterizing bioaccumulation and depuration of gamma emitting radionuclides
mn
co
co
zn
cd
ag
sn
cs
aminitial activity in seawater ( bq dm)3.7 0.10.50 0.0212.1 0.44.1
0.119.6 0.61.26 0.040.18 0.0111.9 0.416.2 0.6activity in p. fucoides after 1 day of exposure ( bq kg dw)3,066 75433 1710,359 1074,285 15517,139
7431,097 34175 381,441 5012,421 155maximum activity in p. fucoides ( bq kg dw)4,961 94819 2113,728 1307,767 18947,832 6381,846 43320 441,465 5423,632 207time of the maximum reaching ( day)555888555isotope bioaccumulation rate for the maximum reaching ( bq kg dw day)992 19164 42,746 26971 245,979 80231
564 9284 104,726 41statistical significance of trends after reaching a maximum correlation coefficient ( r)0.9340.9370.9180.6900.0980.2960.7780.912 significance level ( p)0.00020.00190.00050.03980.80190.43910.01350.0006biological depuration rate constant ( day)0.0440.0370.0350.0290.060biological half time ( day)3.84.04.04.23.5fig .
5cf0 determined for radionuclides for first day of exposure relation of radionuclides activities in p. fucoides to the initial activities in seawater parameters characterizing bioaccumulation and depuration of gamma emitting radionuclides cf0 determined for radionuclides for first day of exposure in the 2011 experiment , the initial development of the curves illustrating activity changes of individual isotopes in the plant tissues was very similar to that registered in the case of cesium isotopes in 2010 ( fig .
the extreme increase in activity concentrations was recorded on the first day of exposure , followed by further accumulation up to a maximum .
the maximal level was reached by six isotopes in 5 days of exposure ( table 2 ) .
there were only three isotopes zn , cd and ag whose activity reached the maximum in 8 days of exposure ( table 2 ) .
further development of the bioaccumulation curves of zn and ag differed from the other isotopes ( fig .
6 ) . beyond the maximum , in the subsequent days of the exposure experiment , their activity concentrations oscillated around a certain average level , which seemed to indicate that the bioaccumulation process had attained the quasi equilibrium stage .
however , after 20 days , their activity concentrations again showed a slight increase .
this might be the expression of the increased contribution of the active bioaccumulation in the overall bioaccumulation process , requiring an additional energy supply related to metabolic processes in the plant tissue .
this observation confirms the greater importance of zn and ag as micronutrients in plant physiology .
in the case of five radioisotopes mn , co , co , cs and ag , a statistically significant decrease in activity concentrations in p. fucoides was observed beyond the maximum ( fig .
the decline in the isotopes activity could be related to the removal of the excess ion , especially facile in the case of ions adsorbed on the surface or taken out from the free space .
the initial , extremely intensive bioaccumulation of ions from the seawater medium caused a considerable decrease in their concentrations in seawater , and this could be the reason for the more effective removal of ions from the plant thalli as an aftermath.fig .
6changes of radionuclides activities ( bq kg dw ) in p. fucoides with time ( days ) changes of radionuclides activities ( bq kg dw ) in p. fucoides with time ( days ) it worth noticing that the half - life time of the individual isotopes radioactive decay was of negligible importance taking into account the duration of the experiment .
its activities in p. fucoides had already declined below the method detection limit after 11 days of exposure , mainly because of its low initial concentration in the seawater medium , and also due to its rather short half - life , ca .
the results obtained in this decreasing , final stage of the experiment were applied to calculate the biological depuration rate constants ( table 2 ) in a single - component model described by equation : \documentclass[12pt]{minimal }
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\begin{document}$$ a_{\text{t } } \ ; = \;a_{0 } { \text{e}}^ { { - \lambda { \text{t } } } } , $ $ \end{document}at = a0e-t , where at is the activity of radionuclide at the end of experiment ( bq kg dw ) , a0 is the maximum activity of radionuclide ( bq kg dw ) , is the biological depuration rate constant ( day ) , t is the time from the maximum until the end of experiment ( day ) .
the constant allows the calculation of the radiotracer biological half - life according to the equation:\documentclass[12pt]{minimal }
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\begin{document}$$ t_{{{\raise0.7ex\hbox{${\text{b1}}$ } \!\mathord{\left/ { \vphantom { { \text{b1 } } { \text{s}}}}\right.\kern-0pt } \!\lower0.7ex\hbox{${\text{2}}$ } } } } \ ; = \;\ln { \raise0.7ex\hbox{$2 $ } \!\mathord{\left/ { \vphantom { 2 \lambda } } \right.\kern-0pt } \!\lower0.7ex\hbox{$\lambda $ } } , $ $ \end{document}tb1b1s2=ln22,where tb1/2 is the biological half - life ( day ) .
the determined biological depuration times of the analyzed isotopes were comparable ( table 2 ) .
americium was the most easily removed isotope ( tb1/2 = 3.5 days ) and cesium ions were the hardest to eliminate ( tb1/2 = 4.2 days ) . in two isotopes of cobalt , the determined biological depuration half - times were equal and reached 4 days .
the different forms of cesium isotopes bioaccumulation curves , in the part subsequent to maximum in a single isotope exposure experiment in 2010 and in a mixture exposure in 2011 , could be the result of competitiveness of sorption and/or bioaccumulation . in a medium where no competing ions occur to block the active sorption locations and fulfill the free space ,
when other isotopes were present in the medium , characterized by decidedly higher bioaccumulation rates , cesium ions became removed from the plant tissue in the second stage of the experiment .
one of the reasons for much slower bioaccumulation of cesium isotopes in comparison to other ions could be its oxidation status ; it was the only ion with the first oxidation number cs .
this might affect the sorption to active spots in the outside plane and walls of the p. fucoides thalli .
cesium exhibited the largest ion diameter ( c.a twice as large as other isotopes ) , which could hamper the passive and active transport into the plant tissue .
the maximal increase of cs and cs activity in p. fucoides was observed after the first day of exposure , independent of the initial radionuclide concentration in the medium ( fig . 2 ) .
the initial concentration of cs ( 137-ceasium ) in seawater was 4.49 0.13 bq dm in aquarium a1 and 8.75 0.18 bq dm in aquarium a2 , while that of cs in aquarium a3 was 51.3 0.3 bq dm .
hence , the lowest experimental concentration of cs ( in a1 ) was already 160 times higher than the environmental concentration , 28.0 0.8 bq m , determined in monitoring measurements in the gulf of gdask.fig .
2changes of cs and cs activities in p. fucoides and seawater with exposure time changes of cs and cs activities in p. fucoides and seawater with exposure time activity concentrations of cs in p. fucoides reached 465.0 32.2 bq kg dw ( dry weight ) and 623.8 22.8 bq kgdw in aquariums a1 and a2 , respectively .
activity concentration of cs in p. fucoides in aquarium a3 reached 5,381 47 bq kg dw .
the initial extremely intensive increase of radioactivity was probably related to the uptake of the radionuclides from the medium , occurring spontaneously and independently of metabolism and requiring no energy input
. then other mechanisms of adsorption and transportation , both passive and active , may play a more important role .
to be adsorbed , each ion has to pass barriers such as the laminar layer , the cell wall and the plasmalemma , before finally reaching the cytoplasm .
the thickness of the laminar layer depends on the turbulence occurring in the surrounding water . under laboratory conditions , due to aeration
, the effect of this layer can probably be excluded and the uptake will not be limited by the rate of diffusion across this layer . generally , during the first stage , ions are introduced to the so - called apparent free space that , in seaweeds , includes the cell wall and all intercellular spaces exterior to the plasmalemma .
the apparent free space consists of two parts ; the first of these is called the water free space and the second one , which relates to the deeper parts of the thallus , is the donnan free space .
this mechanism is likely to explain the oscillations in isotope activities observed in the first 5 days of exposure ion transport in both directions until the equilibrium is reached in the system .
the increase in isotope concentrations in the plant tissue on the 8th day of exposure , i.e. after the quasi - equilibrium was reached , could indicate an increase in the contribution of the active transport mechanism in the bioaccumulation process , the mechanism mainly linked to the plant metabolism .
the bioaccumulation process at this stage is much less intensive because the plasmalemma might be much more difficult to penetrate unlike the cell wall which does not generally present a barrier to ion entry .
the development of isotope activity changes in a seawater medium , illustrated by the curves in ( fig .
2 ) , and is well reflected in the changes occurring in the plant tissue .
the significant decrease in isotope activity concentrations took place during the first 5 days of exposure and , after the 8th day , the concentrations changed very little ( fig . 2 ) .
the concentration process of the ions in plant tissue is related to the dynamic steady state between the uptake and excretion processes .
the concentration factor ( cf ) is the quantitative measure that allows us to assess the relative ability of biota representatives to absorb and/or take up the analyzed trace element . to follow the progress in bioaccumulation process , temporary concentration factors ( tcf )
the tcf of cesium isotopes were increasing over the entire experiment period ; in the case of cs from 114 to 275 dm kg in the aquarium a1 and from 93 to 207 dm kgin the aquarium a2 .
the range of tcf in the case of cs was 144351 dm kg .
3 ) ; r = 0.937 ( p = 0.0006 ) in a1 aquarium , r = 0.922 ( p = 0.0001 ) in a2 aquarium and r = 0.976 ( p
3changes of tcf with exposure time changes of tcf with exposure time the slope of the line , corresponding to the tcf daily increment ( tcf ) , can be considered a rate of isotope bioaccumulation by p. fucoides .
the calculated tcf results were quite close in the case of cs in aquarium a1 ( 8.5 dm kg day ) and cs in aquarium a3 ( 7.7 dm kg day ) .
a slightly lower rate , 5.5 dm kg day , was obtained in a2 aquarium for cs . because the substantial change in activity was observed on the first day of exposure , initial concentration factors ( cf0 )
were determined to compare bioaccumulation efficiency of p. fucoides towards a single isotope in this decisive stage of experiment ; the cf0 was defined as the ratio of the isotope concentration in the plant tissue after the first day of exposure to its initial concentration in the seawater medium . in the case of cesium isotopes
cs ( in aquarium a1 ) and cs ( in aquarium a3)cf0 values were nearly identical : 104 7 and 105 1 dm kg .
this provided evidence that the cf0 did not depend on the initial isotope concentration in the seawater medium .
the bioaccumulation process of cs in a2 aquarium showed slightly different characteristics ; the cf0 = 71 6 dm
kg was much lower than in a1 and a3 , and the changes of tcf in consecutive days varied resulting in a lower daily tcf .
the observed discrepancies indicate a different experimental regime , e.g. a much bigger plant biomass in the aquarium a2 .
the experiment on the bioaccumulation of a mixture of gamma emitting radioisotopes by p. fucoides under laboratory conditions showed a statistically significant linear relation ( r = 0.977 , p = 0.0003 ) of the activity of isotopes in the plant tissue and their initial concentration in a seawater medium after the first day of exposure ( fig . 4 ; table 2 ) .
cs was an exception as its activity in p. fucoides was definitely lower than would be expected from the linear relationship .
at the same time the concentration of cesium in the plant tissue was increasing proportionally to the concentrations in seawater ( fig . 4 ) .
the efficiency of cesium bioaccumulation was nearly eight times lower at the stage than in the case of other radioisotopes , well illustrated by the low slope of the correlation curve ( fig .
this low bioaccumulation efficiency at the initial stage was also marked in the low values of initial concentration coefficients cf0 . in the case of cs , cf0 = 135 7 dm
however , in the experiment in 2011 , the concentration coefficient determined at the equilibrium stage reached 1,547 69 dm kg , i.e. it was over 100 times higher .
the cf0 characterizing the remaining isotopes were varying in a relatively narrow range 862949 dm kg in the case of mn , co , co , cd and ag ( fig .
zn was marked for the highest cf0 = 1,125 57 dm kg.fig .
4relation of radionuclides activities in p. fucoides to the initial activities in seawatertable 2parameters characterizing bioaccumulation and depuration of gamma emitting radionuclides
mn
co
co
zn
cd
ag
sn
cs
aminitial activity in seawater ( bq dm)3.7 0.10.50 0.0212.1 0.44.1 0.119.6 0.61.26 0.040.18
0.0111.9 0.416.2 0.6activity in p. fucoides after 1 day of exposure ( bq kg dw)3,066 75433 1710,359 1074,285
15517,139 7431,097 34175 381,441 5012,421 155maximum activity in p. fucoides ( bq kg dw)4,961 94819 2113,728 1307,767 18947,832 6381,846 43320 441,465 5423,632 207time of the maximum reaching ( day)555888555isotope bioaccumulation rate for the maximum reaching ( bq kg dw day)992 19164 42,746 26971 245,979
80231 564 9284 104,726 41statistical significance of trends after reaching a maximum correlation coefficient ( r)0.9340.9370.9180.6900.0980.2960.7780.912 significance level ( p)0.00020.00190.00050.03980.80190.43910.01350.0006biological depuration rate constant ( day)0.0440.0370.0350.0290.060biological half time ( day)3.84.04.04.23.5fig .
5cf0 determined for radionuclides for first day of exposure relation of radionuclides activities in p. fucoides to the initial activities in seawater parameters characterizing bioaccumulation and depuration of gamma emitting radionuclides cf0 determined for radionuclides for first day of exposure in the 2011 experiment , the initial development of the curves illustrating activity changes of individual isotopes in the plant tissues was very similar to that registered in the case of cesium isotopes in 2010 ( fig .
the extreme increase in activity concentrations was recorded on the first day of exposure , followed by further accumulation up to a maximum .
the maximal level was reached by six isotopes in 5 days of exposure ( table 2 ) .
there were only three isotopes zn , cd and ag whose activity reached the maximum in 8 days of exposure ( table 2 ) .
further development of the bioaccumulation curves of zn and ag differed from the other isotopes ( fig .
6 ) . beyond the maximum , in the subsequent days of the exposure experiment , their activity concentrations oscillated around a certain average level , which seemed to indicate that the bioaccumulation process had attained the quasi equilibrium stage
. this might be the expression of the increased contribution of the active bioaccumulation in the overall bioaccumulation process , requiring an additional energy supply related to metabolic processes in the plant tissue .
this observation confirms the greater importance of zn and ag as micronutrients in plant physiology . in the case of five radioisotopes mn , co , co , cs and ag , a statistically significant decrease in activity concentrations in p. fucoides was observed beyond the maximum ( fig .
the decline in the isotopes activity could be related to the removal of the excess ion , especially facile in the case of ions adsorbed on the surface or taken out from the free space .
the initial , extremely intensive bioaccumulation of ions from the seawater medium caused a considerable decrease in their concentrations in seawater , and this could be the reason for the more effective removal of ions from the plant thalli as an aftermath.fig .
6changes of radionuclides activities ( bq kg dw ) in p. fucoides with time ( days ) changes of radionuclides activities ( bq kg dw ) in p. fucoides with time ( days ) it worth noticing that the half - life time of the individual isotopes radioactive decay was of negligible importance taking into account the duration of the experiment .
its activities in p. fucoides had already declined below the method detection limit after 11 days of exposure , mainly because of its low initial concentration in the seawater medium , and also due to its rather short half - life , ca .
the results obtained in this decreasing , final stage of the experiment were applied to calculate the biological depuration rate constants ( table 2 ) in a single - component model described by equation : \documentclass[12pt]{minimal }
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\begin{document}$$ a_{\text{t } } \ ; = \;a_{0 } { \text{e}}^ { { - \lambda { \text{t } } } } , $ $ \end{document}at = a0e-t , where at is the activity of radionuclide at the end of experiment ( bq kg dw ) , a0 is the maximum activity of radionuclide ( bq kg dw ) , is the biological depuration rate constant ( day ) , t is the time from the maximum until the end of experiment ( day ) .
the constant allows the calculation of the radiotracer biological half - life according to the equation:\documentclass[12pt]{minimal }
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\begin{document}$$ t_{{{\raise0.7ex\hbox{${\text{b1}}$ } \!\mathord{\left/ { \vphantom { { \text{b1 } } { \text{s}}}}\right.\kern-0pt } \!\lower0.7ex\hbox{${\text{2}}$ } } } } \ ; = \;\ln { \raise0.7ex\hbox{$2 $ } \!\mathord{\left/ { \vphantom { 2 \lambda } } \right.\kern-0pt } \!\lower0.7ex\hbox{$\lambda $ } } , $ $ \end{document}tb1b1s2=ln22,where tb1/2 is the biological half - life ( day ) .
the determined biological depuration times of the analyzed isotopes were comparable ( table 2 ) .
americium was the most easily removed isotope ( tb1/2 = 3.5 days ) and cesium ions were the hardest to eliminate ( tb1/2 = 4.2 days ) . in two isotopes of cobalt , the determined biological depuration half - times were equal and reached 4 days .
the different forms of cesium isotopes bioaccumulation curves , in the part subsequent to maximum in a single isotope exposure experiment in 2010 and in a mixture exposure in 2011 , could be the result of competitiveness of sorption and/or bioaccumulation . in a medium where no competing ions occur to block the active sorption locations and fulfill the free space ,
when other isotopes were present in the medium , characterized by decidedly higher bioaccumulation rates , cesium ions became removed from the plant tissue in the second stage of the experiment .
one of the reasons for much slower bioaccumulation of cesium isotopes in comparison to other ions could be its oxidation status ; it was the only ion with the first oxidation number cs .
this might affect the sorption to active spots in the outside plane and walls of the p. fucoides thalli .
cesium exhibited the largest ion diameter ( c.a twice as large as other isotopes ) , which could hamper the passive and active transport into the plant tissue .
bioaccumulation of cesium radioactive isotopes as well as other gamma emitting isotopes in p. fuoides under laboratory conditions showed similar features .
the spectacular change in activity concentrations of the isotopes in p. fucoides was recorded in the first day of exposure to a seawater medium spiked with radioactive ions.biosorption connected to surface binding of ions and bioaccumulation in the so - called free space , including the cell wall and all the cellular spaces exterior to the plasmolemma , are likely to be the dominant processes at this stage.during the entire experiment , the tcf of cs and cs increased linearly and their initial concentration coefficients cf0 did not depend on the initial isotope concentration in the seawater medium.the experiment on bioaccumulation of a mixture of gamma emitting radioisotopes by p. fucoides under laboratory conditions showed a statistically significant linear relation between the activity of isotopes in the plant tissue and their initial concentration in a seawater medium after the first day of exposure . since this relation , in the case of cs , was described by another equation , it provides evidence of different characteristics of the bioaccumulation process regarding radioactive cesium.because of the very short time of environmental response and considerable bioaccumulation efficiency , p. fucoides should be recommended as a bioindicator of radioactive pollution , both under static and accidental circumstances .
bioaccumulation of cesium radioactive isotopes as well as other gamma emitting isotopes in p. fuoides under laboratory conditions showed similar features .
the spectacular change in activity concentrations of the isotopes in p. fucoides was recorded in the first day of exposure to a seawater medium spiked with radioactive ions .
biosorption connected to surface binding of ions and bioaccumulation in the so - called free space , including the cell wall and all the cellular spaces exterior to the plasmolemma , are likely to be the dominant processes at this stage . during the entire experiment ,
the tcf of cs and cs increased linearly and their initial concentration coefficients cf0 did not depend on the initial isotope concentration in the seawater medium .
the experiment on bioaccumulation of a mixture of gamma emitting radioisotopes by p. fucoides under laboratory conditions showed a statistically significant linear relation between the activity of isotopes in the plant tissue and their initial concentration in a seawater medium after the first day of exposure . since this relation , in the case of cs , was described by another equation , it provides evidence of different characteristics of the bioaccumulation process regarding radioactive cesium .
because of the very short time of environmental response and considerable bioaccumulation efficiency , p. fucoides should be recommended as a bioindicator of radioactive pollution , both under static and accidental circumstances . | ### Summary:
: the article presents the results of a study on the bioaccumulation abilities of polysiphonia fucoides , a red algae specific to the southern baltic sea , towards ( of ) gamma emitting isotopes .
a laboratory experiment was carried out to determine changes in the activities of some isotopes54mn , 57co , 65zn , 110mag,113sn , 134cs , 137cs and 241am occurring in p. fucoides exposed to a seawater medium containing these isotopes over the course of 1 month .
all analyzed isotopes showed the greatest increase of radioactive activity in plant tissue in the first 24 h of exposure .
the temporary concentration factors of cesium isotopes were increasing linearly during the experiment from 114 to 274 in the case of 137cs , and from 144 to 351 in the case of 134cs .
the level of the initial concentration factor of cesium isotopes in the plant proved to be independent of the initial concentration of the isotope in seawater and it took the lowest ( 125 dm3 kg1 ) level among the studied isotopes . in the case of a mixture of gamma emitting isotopes ,
a linear relation between the individual isotope activity in p. fucoides and its initial concentration in seawater was established after the first day of exposure ; the isotopes initial concentration factors ranged from 767 to 874 dm3 kg1 .
having reached the maximal concentration level , a statistically significant decline in radioactivity concentrations of the five isotopes in the plant tissue was observed .
a half - life of biological removal of the isotopes from the plant tissue was established at : 3.8 days in the case of 54mn , 4 days57co , 4 days60co , 4.2 days137cs and 241am3.5 days . |
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: intracavitary brachytherapy ( icbt ) , in conjunction with external beam radiation ( ebrt ) and chemotherapy , is the standard of care in the curative management of locally advanced cervical cancer . while cure rates for early cervical cancer with combinations of ebrt and icbt are excellent , the unpredictable nature of serious morbidity of the bladder and rectum remains a serious problem .
a successful treatment includes not only an improvement on tumor control , but also a reduction in treatment - related complications .
it has been documented in the medical literature that there is a linear correlation between complications and total dose to the bladder and rectum [ 2 , 3 ] .
clinically significant consequences of irradiation of the urinary bladder in icbt for cervical cancer have been well recognized .
shape and volume of bladder during icbt may affect dosimetric patterns of bladder , rectum and sigmoid colon .
evacuation of bladder by foley 's catheter is a common practice in icbt , but even so , residual volume of urine is still seen on three dimensional ( 3d ) imaging .
non - contiguous high dose areas especially in lateral horns of bladders are a major factor of dose heterogeneity of bladder .
it may be assumed that bladder tone may affect bladder shape by influencing dose distribution .
parity which influences bladder tone may be confounding factor for bladder volume - dose linear relationship . in 1981 ,
pilepich et al . found that by maintaining a good residual bladder volume radiation exposure to a large part of the bladder was reduced significantly .
bladder distension also affects dose distribution of rectum and sigmoid colon as distended bladder shifts the rectum and sigmoid colon .
cengiz et al . did not found any significant differences in the dose distributions between an empty or full bladder . but
bladder fullness significantly affected the dose to the small intestine , rectum , and sigmoid colon .
this study aims to evaluate the effects of bladder distension on dosimetry , assessed by 3d image based planning techniques , in bladder , rectum , sigmoid colon and small intestine in cervical cancer patients during brachytherapy , and also to search for any other factor influencing the scenario . in this study
we have analyzed the potential effects on dosimetry while the clinical correlation will be discussed at a later time .
the study included forty seven patients of cervical cancer treated in our institute between 2009 and 2011 . all patients with pathologically proved cervical cancer ( stage ib to iva ) who had given a written consent
age below 18 years or more than 70 years , patients having pregnancy , or prior exposure to radiation therapy due to any other reason were excluded from the study .
all patients were treated with ebrt ( theratron 780c , theratronics international , kanata , ontario , canada ) to the whole pelvis ( 50 gy in 25 fractions using four field box technique ) .
intracavitary brachytherapy was done under sedation using ct compatible applicators ( manchester type or fletcher - suit type ) . soon after first intracavitary insertion patients were sent for planning ct scan ( brilliancect-16 slice with accusim virtual simulation , philips health care solutions , da best , the netherlands ) .
ct scans were obtained from the level of the obturator foramen to at least 1 cm beyond the tandem tip in the cephalad direction with 3 mm slice thickness . in thirty six patients , just before ct scan , we instilled different fixed volumes of normal saline in urinary bladder by foley 's catheter , followed by clamping of the catheter while the rest were scanned with empty bladder with continuous drainage by foley 's catheter . patients were stratified into 4 different groups : group a empty bladder group ( defined as no extra saline or contrast material given after foley 's catheter insertion , gentle evacuation of bladder done by foley 's catheter ) ; group b ( up to 40 cc instillation ) ; group c ( 4180 cc instillation ) ; group d ( 81 cc and above instillation ) .
the ct data was transferred to the treatment - planning system ( brachyvision tps , eclipse , varian medical systems , palo alto ca , usa ) computer .
contrast material was mixed with saline to define the bladder wall ; barium was instilled into the sigmoid and rectum .
the external contour of the bladder , rectum , sigmoid colon , and small bowel in the pelvis were delineated on each ct slice . in this study ,
the rectum was delineated from the anal verge to the recto - sigmoid junction , and the sigmoid colon was defined as the large bowel above the rectum to the level of the lumbosacral interspace .
the bowel excluding the sigmoid colon and rectum in the pelvis was defined as small bowel .
the reason for contouring the whole organ is a possibility of thinning of walls due to bladder distension leading to changes in dvh parameters of small volume doses if only wall is taken for contouring .
the prescribed dose was either 7 gy 3 fractions or 9 gy 2 fractions of hdr at point a. point a was defined as 2 cm superior of the upper surface in the middle of the ovoid and 2 cm lateral to the uterine tandem ( same coronal plane ) on reconstructed ct image .
3d manual optimization of the hdr plans were done , if required , to achieve acceptable doses to point a , bladder , rectum and sigmoid colon .
patient were then treated by the gammamedplus hdr afterloader unit ( varian medical systems , palo alto , ca , usa ) using iridium-192 ( figs . 1 , 2 ) .
different doses and dose volume data were assessed for the bladder , rectum and sigmoid colon from the cumulative dose volume histograms ( dvh ) . these include doses to 0.1 cc , 1 cc and 2 cc volumes of each of the structures , as well as the maximum and mean doses ( fig .
3 ) . statistical analysis was done using the spss software ( version 19.0 ) .
dose volume data from different groups were compared using independent t sample test , multivariate regression model ( anova , post hoc test ) .
adjustment for potential confounders ( including parity , tumor stages , and type of applicator used ) was performed in multiple linear regression models .
image of axial section of computer tomography showing isodose curves during intracavitary brachytherapy of cervical cancer patient image of coronal section of computer tomography showing isodose curves during intracavitary brachytherapy of cervical cancer patient image of dose volume histogram showing dose distribution pattern over cervix , bladder , rectum , sigmoid colon during intracavitary brachytherapy of cervical cancer
among all forty seven patients , maximum population was in group c ( n = 18 , 38% ) and minimum patient population was observed in group d ( n = 6 , 12% ) . most common stage was stage iib ( n = 21 , 44% ) followed by stage iiib ( n = 10 , 21% ) .
majority of patients were treated with manchester type of applicator ( n = 28 , 59.6% ) ( table 1 ) .
median value of point a dose in all groups was 6.99 gy ; mean value of point a dose was 7.028 0.67 gy ( table 2 ) .
detailed dose patterns of bladder doses ( maximum dose , mean dose , 0.1 ml dose , 1 ml dose , 2 ml dose ) are described in table 3 .
on post hoc test analysis and multivariate analysis during multiple comparisons among each groups we found that mean dose of bladder was significantly decreased in group d in comparison to group a ( p = 0.001 ) and also with group b ( p = 0.038 ) ( table 4 ) .
mean values of mean doses of bladder were 3.2 gy in group a , 2.9 gy in group b , 2.8 gy in group c and 2.2 gy in group d. these findings were also validated by kruskal wallis test ( monte carlo significance was 0.02 ) and mann whitney u test .
description of different dose distribution parameters of rectum and sigmoid colon are given in table 5 and table 6 .
descripted statistics group a : empty bladder ; group b : up to 40 cc ; group c : 41 - 80 cc ; group d : > 81 cc point a dose in different study groups comparative dose distrbution pattern in bladder in different groups 0.1 cc dose : minimum dose to the maximally exposed 0.1 cc volume extrapolated from statistically significant bladder mean dose distribution on multiple comparison ( post hoc test ) p value < 0.05 is statistically significant comparative dose distribution pattern in rectum among different groups 0.1 cc dose : minimum dose to the maximally exposed 0.1 cc volume extrapolated from dose volume histogram comparative dose distribution pattern in sigmoid colon among different groups 0.1 cc dose : minimum dose to the maximally exposed 0.1 cc volume extrapolated from dose volume histogram in the same way we compared the different dose distribution patterns ( maximum dose , mean dose , 0.1 cc , 1 cc and 2 cc volume dose ) of rectum and sigmoid colon by using multivariate analysis , post hoc test and kruskal wallis test .
there were statistically insignificant minute changes in dose distribution in rectum and sigmoid colon ( tables 5 and 6 ) .
mann whitney u test was used to compare different groups , but no statistically significant difference was found . on analysing results of independent t sample test results of the dosimetric data of small intestine we found that dose values ( maximum dose , 1 cc , 2 cc doses ) are significantly decreased only in group d in comparison to group a. however , no statistical difference exists while comparing other groups ( table 7 ) .
comparative dose distribution pattern in small intestine between group a and d ( independent t sample test ) 0.1 cc dose : minimum dose to the maximally exposed 0.1 cc volume extrapolated from dose volume histogram p value < 0.05 significant on analysing covariables such as parity , stage , applicator type ( multivariate analysis )
it has been found that maximum dose , 0.1 cc and 1 cc volume doses increased with parity ( p = 0.0025 ) and they were significantly correlated ( pearson correlation coefficient = 455.25 ) ( table 8) . but no significant change was seen 2 cc bladder , rectum and sigmoid colon dose parameters .
dose pattern changes were not influenced either by stage of the disease or applicator type .
it was also evident from data analysis that in the empty bladder group ( group a ) there was a significant amount of urine collection was noticed even after evacuation .
mean bladder volume ( contoured ) from the ct images was 129.25 19.1 cc .
relation of parity and bladder dose ( anova test result corrected model using parity as co variable ) p value < 0.05 is statistically significant minimum dose to maximally exposed 0.1 cc volume of bladder
this study investigated the bladder distension effect on dosimetry in 47 patients with cervical cancer receiving icbt .
we found that bladder mean dose significantly decreases from empty bladder group to distended bladder group ( 3.2 gy in group a , 2.9 gy in group b , 2.8 gy in group c and 2.2 gy in group d ) .
this concept was especially beneficial for low - dose - rate ( ldr ) brachytherapy where the treatment time was longer .
alteration of bladder filling status and shape and position of bladder alters the relative anatomy of uterus , sigmoid colon intestinal loop and also rectum .
it had been assumed that the distended bladder might shift the sigmoid colon and intestinal loop from the uterus , thereby having a sparing effect on sigmoid colon , intestinal loop and may be on rectum . in 1981 , pilepich et al .
they found that by maintaining a residual vesical volume of 200 - 300 cc with contrast material , the radiation exposure to a large part of the bladder was reduced significantly , while only a minor displacement of the implant system was noted .
analyzed dvh data of 20 cervical cancer patients with empty and full bladder volumes and found that there is a statistically significant association between bladder filling status and median bladder wall absorbed dose .
bladder distension can approximately reduce the median bladder wall absorbed dose by 48% , and they concluded that this procedure may reduce the incidence of acute reactions and long - term complications .
have studied over 29 women regarding determination of the impact of the filling status of the organs at risk ( bladder and rectum ) on the uterus mobility and on their integral dose distribution in radiotherapy of gynecological cancer .
they have found that full bladder is an important factor for sparing dose burden for this organ , particularly if more than one third of the bladder is taken into consideration .
kim et al . have shown that an increase in bladder volume resulted in a significant reduction in 2 cc bowel volume doses at the expense of an increase in 2 cc bladder volume doses .
however , this study did not provide any information regarding clinical correlation of these changes .
have studied ten patients with empty and full bladder and found no significant difference regarding the dose distribution and target volumes between an empty or full bladder . but bladder fullness significantly affected the dose to the small intestine , rectum , and sigmoid colon .
our study was intended to reevaluate these findings . in our study , there were four groups .
in group a ( empty bladder group ) we tried gentle evacuation of bladder by foley 's catheter .
but still there was a significant residual urine volumes ( mean contoured volume was 129 19 cc ) .
in group d average instillation was 100 cc ( 80 - 120 cc ) unlike previous studies .
this volume was comfortably tolerated by patients . unlike other studies we treated all the patients with same bladder filling status as done during imaging .
no magnetic resonance imaging ( mri ) was done . during contouring we took whole organ for contouring ,
calculation and comparison mean values of maximum , mean doses of bladder , rectum and sigmoid colon were taken as like previous studies .
we also included small volume dose values ( 0.1 cc , 1 cc , 2 cc ) following gec - estro recommendations [ 5 , 9 ] , as these volumes are key parameters to evaluate late toxicities .
main emphasis was given during analysis on how these small dose volume parameters were affected . during intergroup analysis we found all the dose volumes were changing in different groups , but all the changes were not statistically significant .
there was no significant change in the mean value of maximum dose to bladder unlike previous studies .
only the mean value of bladder mean dose significantly decreases with increasing bladder ( p = 0.001 ) distension .
there were no significant changes in 0.1 cc , 1 cc , 2 cc volume dose values of bladder .
unlike previous studies changes of dose volume parameters of rectum and sigmoid colon were not significant .
but in case of small intestine , the analyzed dose parameters ( maximum dose , 0.1 ml dose , 1 ml dose and 2 cc dose ) are significantly decreased on bladder distension . in a similar prospective study , kim et al .
found an increase in bladder volume resulted in a significant reduction in bowel 2 cc dose values at the expense of an increase in bladder 2 cc and mean dose values .
they conclude that the treatment with a distended bladder is preferable to protect the bowel .
our study results partially corroborate with these findings . on analyzing the confounding factors it was evident that weak positive correlation exists between parity and mean values of bladder maximum dose ( average p = 0.0025 ) .
we assumed that high parity might have influenced bladder tone and increase the high dose areas of lateral horns , which was evident on comparing the planning ct images . analyzing all these changes , though there was decrease in bladder mean dose in distended bladder group , the result was not encouraging , as there was no change of 1 cc and 2 cc bladder volume doses .
but interestingly , our results revealed decrease in all small intestine volume dose parameters in this group .
the group a population had significant residual volume of urine after evacuation which may be a confounding factor , though not statistically significant ( p = 0.46 ) .
clinical outcomes were not evaluated in this study , the dosimetry alteration shown by the treatment planning system may not completely reflect clinical bladder complications .
there is no significant change in dosimetric parameters of bladder , rectum and sigmoid colon with bladder distention except small intestine , where the values ( maximum doses , 0.1 cc , 1 cc and 2 cc doses ) are decreased on bladder distension .
but the small volume dose parameters ( 0.1 cc , 1 cc and 2 cc ) of bladder , rectum and sigmoid colon , which are actually important for late toxicities in icbt patients , were unchanged . clinical significance of these changes are unknown . a larger study with clinical correlation of late toxicities | ### Summary:
: purposedistension and shape of urinary bladder may vary during intracavitary brachytherapy ( icbt ) for cervical cancer , significantly affecting doses to bladder , rectum , sigmoid colon and small intestine and consequently late radiation toxicities .
this study is to evaluate the effects of different fixed volume bladder distention on dosimetry , assessed by three dimensional image based planning , in different organs at risk during the treatment of cervical cancer with icbt.material and methodsforty seven cervical cancer patients ( stage ib to iva ) were qualified for icbt following external beam radiotherapy .
urinary bladder was distended with different volumes of normal saline instilled by a foley 's catheter . planning ct scans were performed after insertion of applicators and three dimensional treatment planning was done on brachyvision treatment planning system ( varian medical systems , palo alto , ca ) .
dose volume histograms were analyzed .
bladder , rectum , sigmoid colon and small intestine doses were collected for individual plans and compared , based on the amount of bladder filling.resultsmean dose to the bladder significantly decreased with increased bladder filling .
however , doses to the small volumes ( 0.1 cc , 1 cc , 2 cc ) which are relevant for brachytherapy , did not change significantly with bladder filling for bladder , rectum or sigmoid colon . nevertheless , all dose values of small intestine are decreased significantly with bladder filling.conclusionsbladder distension has no significant effect on doses received during brachytherapy by relevant volumes of bladder , rectum and sigmoid colon except intestine where values are decreased with bladder distension .
a larger study with clinical correlation of late toxicities is essential for proper evaluation of this strategy . |
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: parapneumonic effusion is an uncommon complication of childhood pneumonia , but still a common problem in many countries , since the optimal management remains controversial .
many treatment options are available ; while most cases of parapneumonic pleural effusion respond to antibiotic therapy only , those who fail to medical treatment need antibiotic therapy and tube drainage , and a few cases require further surgical treatment as thoracotomy , pleural debridement , and decortication .
thoracocentesis alone may be sufficient for the exudative phase . in fibrino - purulent stage ,
a properly sized and well - placed tube thoracostomy with underwater seal is curative in most cases .
open surgery with decortications is indicated if there is no response with intercostals drainage procedure , in presence of underlying lung disease or persistently symptomatic effusion .
modern strategies include a conservative approach with use of chest drain and intrapleural fibrinolytic therapy and video assisted thoracoscopic therapy ( vats ) , but both are unavailable in our clinic at the moment .
we reviewed our experience with a number of children with parapneumonic effusion or empyema who failed to respond to previous medical treatment , admitted over a time interval of 30 months .
our objectives were to gather data on the clinical presentation and to examine the effect of different management strategies on short term outcomes .
we performed a retrospective case note review of children admitted with parapneumonic effusion or empyema to the department of pediatric surgery , children s hospital , cluj - napoca , between january 2010 to july 2012 ( 30 months ) .
cases were selected by searching coded discharged medical records , and cases of pleural effusion which were not due to lung infection were excluded .
a total of 16 children ( 9 girls and 6 boys ) were treated for postpneumonic effusions or empyema in our department of pediatric surgery , children s hospital , cluj - napoca in the 30 months period of time . diagnosis was established by case history , clinical features , chest x - ray ( chest x - ray ) , ultrasound chest ( us ) , and computer tomography scan ( ct ) , where available .
classification of postpneumonic effusion was made using ultrasound appearances as it follows : stage one refers to a fluid collection without loculations ; stage 2 has fibrinous septations but no homogeneous echogenic loculations or thickened parietal rind , and stage 3 has a complex ultrasound appearance with multiple loculations and entrapped underlying lung .
decisions regarding treatment options were taken by the clinician involved ( pediatric surgeon ) . in order to control the infection ,
the objectives of the treatment were : - drainage of purulent fluid - eradication of the sac to prevent chronicity - re - expansion of the affected lung - restore complete lung function drainage of the pleural cavity is an essential component in the treatment of large pleural effusions and is necessary for establishing re - expansion of the lung .
the recommendation of chest drainage as treatment is easy for a child with moderate to severe respiratory distress , a large pleural effusion or sepsis .
the decision is much more difficult in patients in the early stages with mild respiratory distress and small effusion because some of them will resolve spontaneously .
the treatment options available today are : - chest drain insertion alone - chest drain with instillation of fibrinolytics - ( not available in our clinic at this moment ) - vats ( video assisted thoracoscopic surgery ) ( not available ) - open thoracotomy and decortications , closure of fistula if necessary patients were divided into groups according to the therapeutic procedure , as follows : chest drain alone or thoracotomy .
we analyzed the length of hospital stay , the associated morbidity and mortality for both groups .
all children required associated supportive therapy ; which includes measures meant to help : - children should have supplemental oxygen if their saturation is below 9093% - sometimes children needed intubation and ventilation for respiratory support - other standard therapy included : fluid replacement , antipyretics and analgesia - the child is encouraged to early mobilization and deep breathing and coughing - the child needs adequate analgesia to allow painless respiration and mobilization all children with empyema received antibiotic intravenous therapy in high dose and important to ensure pleural penetration .
initially , in the absence of a positive culture the choice is dependent on local bacterial causes of community acquired pneumonia and local antibiotic policy will vary .
the presence of pneumatoceles on chest x - ray raises the suspicion of s. aureus or s. pneumoniae .
antibiotic therapy is important to ensure pleural penetration using high doses by intravenous administration in the early stages of the disease .
once a child has been free of fever for 24 hours , antibiotics can be given orally , for at least 7 days and up to 6 weeks of oral therapy .
initially , all 16 patients underwent closed intercostals drainage with a chest tube attached to an underwater seal system .
the chest tubes were inserted in the operating room , under intravenous sedation , using fully monitoring equipment .
chest tubes were introduces in fourth or fifth intercostal space mid - clavicular or anterior axilar line , under general anesthesia .
persistent fever is the commonest indication of possible treatment failure , caused by either incorrect antibiotic choice or failure of the antibiotics to penetrate the infected lung tissue or cavity .
however , it is recognized that in some cases it will persist for many days due to lung necrosis and inflammation rather than continued sepsis . in these circumstances ,
a ct scan is indicated for persisting fever and a rise in wbc and cpr , to exclude a pulmonary abscess or other collection of pus which may not be visible on a chest x - ray .
cavitary necrosis , necrotizing pneumonia and pneumatoceles may be present on ct scans and are often a complication of empyema .
necrotizing pneumonia may result in a prolonged hospital stay but still the outcome is good .
a bronchopleural fistula occurs occasionally following the insertion of a chest drain or surgery , for the treatment of empyema , due to the fragility of lung parenchyma , which leads to a persistent air leak , in these cases , negative suction on chest drain is best avoided , to improve the chance of tissue healing .
a few patients ( 4 ) whose chest x - ray or ct showed severe pleural thickenings , loculated empyema and trapped lung with poor clinical recovery went through thoracotomy with decortications ( group ii ) .
the pleural space was entered through the fifth or sixth intercostals space , with rib resection .
the intrapleural debris , fibrin mass and all pus were evacuated and the fibrinous peel on the surface of the visceral and parietal pleura was carefully removed .
two chest tubes were inserted into the pleural space for underwater drainage , with low negative pressure ( 15 to 20 cm h2o ) .
video - assisted thoracoscopic surgery ( vats ) was not performed because of a lack of technical facilities .
early intervention with the use of vats in the treatment of empyema in children may reduce hospital costs by shortening hospital stay .
once a patient had no oxygen requirement , the chest tube had been removed and oral antibiotics administered for 24 hours , he / she could be discharged .
percutaneous drains are less invasive and painful and thus encourage mobilization and may aid recovery .
chest drains can be removed if there is less than 12 ml / kg fluid per 24 hours .
the presence of the drain in the pleural cavity itself causes irritation and increases production of pleural fluid and therefore it is not advisable to wait until there is no fluid drainage before removing the drain .
a chest x - ray should be performed following removal ; the presence of some air in the pleural space is not uncommon , and is usually reabsorbed in time .
oral antibiotics should be continued at home for at least one week and may be continued for up to 6 weeks .
a follow - up chest x - ray should be performed at weeks 4 and 6 to ensure that resolution occurs .
this x - ray will not be normal yet , despite complete clinical recovery of the child , in most cases some residual thickening is present even 6 weeks after discharge .
further imaging studies are needed only if there is persistent lobar collapse or there are ongoing clinical symptoms .
the most common symptoms and signs at admission in our groups were : fever ( 87.5% ) , cough ( 81.25% ) , dyspneea ( 56.25% ) , lethargy ( 25% ) , decrease appetite ( 25% ) and abdominal pain ( 12.5% ) .
there were 6 right - sided , 9 left - sided pleural effusions and 1 bilateral effusions .
the rest were difficult to identify because patients previously received antibiotics for the treatment of pneumonia at a different medical unit or at home where the disease started .
initial treatment with chest tube drainage alone was successful in 12 ( 75% ) patients , representing group i. in the 4 patients ( 25% ) in which the treatment failed , open thoracotomy and decortications was applied ( figure 1 ) .
the median hospital stay was 15.5 days in group i and 24.25 days in group ii . in our group of 16 pediatric patients , we had no mortality .
morbidity referred to presence of bronchopleural fistulas which were identified by the presence of air in pleural space ( hydropneumothorax ) , and were treated using only underwater sealing drainage ( 4 cases in group ii ) or by closing fistula during thoracotomy ( 1 case in group ii ) and one case of lung abscess in group i , treated only with antibiotics , with good outcome .
this study provides a retrospective review of the management of a group of children with parapneumonic effusion over a short time interval . when chest drains are used alone
, patients can make a complete recovery , even with the cost of longer hospital stay .
furthermore , some patients often require extensive surgical treatment as open thoracotomy with decortication due to failure to respond to chest - tube drainage .
of the 16 children who had an intercostals chest drain , 4 ( 25% ) returned to the operating theatre for a thoracotomy .
organisms were identified in just a few cases , because children were previously treated for respiratory infections at home or in a different medical center , without microbiological studies .
length of hospital stay was longer for children who had open thoracotomy with decortication , because they were previously treated with chest - drain tubes , with poor outcome or results .
there are studies in literature showing short hospital stay for children who had open thoracotomy as first treatment , immediately after admission , as compared to those who had chest - tube drainage but this remains controversial .
the instillation of intrapleural fibrinolytics such as urokinase or tissue plasminogen activator through chest drains shortens hospital stay when compared with chest drain alone .
it is thought that fibrinolytics act by breaking down fibrin bands which cause loculations of the empyema , thus improving drainage of the infected material by chest tube and also clearing pleural drainage and re - establishing pleural circulation .
open thoracotomy is not recommended as first option for treatment of childhood empyema as it has been superseded by the use of vats .
the advantages over open surgery are that it is minimally invasive and the small scars limit tissue damage .
the disadvantages are that the equipment is expensive and requires surgical expertise , which may not be available in all medical centers .
we need to gain more experience to properly identify the optimal time for performing open thoracotomy , with low costs and to reduce suffering and long hospital stay for our patients .
still , the majority of them will need only drainage with good outcome on short and long term , since it is well known that children have a greater capacity to resorb thickened pleura than adults .
maybe in the future we will be able to perform instillation of fibrinolytics or even vats to improve our results by decreasing morbidity and shorten hospital - stay . | ### Summary:
: aimswe analyzed and examined the effect of different management strategies on short term outcomes for pediatric patients with parapneumonic pleural effusions.patients and methodswe retrospectively reviewed 16 cases of children admitted and treated in our department of pediatric surgery for empyema or pleural effusions for a period of 30 months.resultswhen chest drains are used alone , patients can make a complete recovery , even with the cost of longer hospital stay .
furthermore , some patients often require extensive surgical treatment as open thoracotomy with decortication due to failure to respond to chest - tube drainage.conclusionsbecause of the relatively small number of patients with parapneumonic effusions and because of lack of modern possibilities that require expensive equipment , like vats or fybrinolitic therapy , our study results are limited and need to be reviewed in time .
even so , results on short outcome are good , with low morbidity and mortality , but with higher costs . |
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: hence , the use of sub - tenon block ( stb ) has become more common for ocular surgery .
however , some complications of stb have also been reported including , rectus muscle paresis , diplopia , central spread , orbital cellulitis , and/or other vascular damage .
globe perforation after stb is a rare but catastrophic complication . the risk factor is higher with an inexperienced user , poor technique and in a previously operated eye due to adhesions .
it is metallic and has a curved shaft and flattened tip [ figure 1 ] .
the olive tip ( ot ) cannula is primarily used to free the intraocular adhesions secondary to previous inflammation or adhesions over the capsular bag during cataract surgery .
this cannula has a smooth oval tip and a malleable shaft compared to the st cannula .
it also has a smaller gauge ( 25 ) but comparable length ( 26 mm ) to the st cannula [ figure 2 ] .
we assumed that ot cannula can be used for stb , due to the very similar design to the st cannula .
in addition , the ot cannula may be less traumatic due to the smoother bulbous tip and smaller gauge , especially in patients with sclerotic vessels or in eyes with adhesions from a previous surgery . this prospective , randomized study compared the efficacy of ot cannula to the st cannula for the delivery of stb for cataract surgery . standard steven 's cannula
a total of 120 patients , scheduled for phacoemulsification cataract surgery under local anesthesia having the american society of anesthesiologist physical status i - iii were enrolled in this study .
patients were randomly allocated into two groups using a sealed envelope technique to receive stb with st cannula ( st group ) or an ot cannula ( ot group ) .
after approval from institutional review board , written informed consent was obtained from all patients .
patients with a known allergy to local anesthetics , previous retinal surgery with a scleral buckle in place , previous strabismus surgery , localized infection , previous stb in the same quadrant , and those on anticoagulant therapy or nonsteroidal anti - inflammatory drugs were excluded from the trial .
patients were also excluded if they declined to consent or had any communication difficulties . to calculate sample size , we assumed that pain during delivery of anesthesia and surgery will occur in 20% of the st group and 5% of the ot group .
to achieve 95% confidence interval ( ci ) and 90% power to the study with 1:1 ratio in two study arms , at least 51 patients were required in each group . to compensate for patient dropout and introduction of an additional anesthetic agent , we increased the sample size to sixty patients in each arm .
the technique of stb for both groups involved the instillation of three drops of 0.4% oxybuprocaine ( benoxinate ) followed by two drops of 1% tetracaine and one drop of 5% iodine .
a lid speculum was inserted and the conjunctiva and tenon 's capsule were incised with westcott scissors in the inferonasal quadrant , approximately , 5 mm from the limbus .
the cannula was slowly advanced through the incision in the infero - posterior direction in a sliding pattern .
the cannula was gently moved right and left while advancing to separate the tissue and 46 ml of a mixture of local anesthetic solution ( bupivacaine 0.5% , lidocaine 2% in a 3:2 volume ratio and hyaluronidase 5 unit / ml ) was slowly injected .
the cannula was withdrawn , and the incision site was compressed with a sterile cotton - tipped applicator for 2 min for hemostasis . to decrease the chance of postoperative endophthalmitis , the second drop of 5% iodine
ocular movements were assessed at 5 and 10 min after the block . a simple akinesia score ( globe movement - inferior , superior , medial , and lateral ) was used for assessment of stb .
normal movement graded as two and reduced movement as one while a flicker to no movement was graded as zero .
similarly , eyelid movement was separately scored as 0 for complete ptosis , 1 for partial ptosis and 2 for no ptosis .
a primary anesthesiologist performed the block in the holding area while a second anesthesiologist assessed the block , once the patient was moved into the operating room .
the surgeon was also asked to rate his own satisfaction level about the quality of block using a subjective score with a verbal scale , from 0 ( total dissatisfaction ) to 10 ( total satisfaction ) . a visual analog scale ( 010 )
was used to assess the level of patient pain during the block and at the end of the procedure .
the amount of supplementary local anesthetic ( if required ) was also recorded for the study .
, new york , ny , usa ) was used for statistical analysis . numbers and percentages were calculated for qualitative outcome variables . the relative risk and 95% ci with a two - sided p value
quantitative outcome variables were plotted to determine the distribution pattern . if they were normally distributed , the mean and standard deviation was calculated . to compare the outcomes between groups , we calculated the difference of mean , the 95% ci and a two - sided p value .
sixty patients were included in each of the group , and there were no dropouts from either group .
the mean age of participants was 64.7 12.0 years in the ot group and 63.0 11.2 years in st group ( difference of mean = 1.65 ; 95% ci 2.55.8 ; p = 0.6 ) .
the mean bmi was statistically significantly lower in the ot group at 29.9 14.8 kg / m compared to 32.3 6.5 kg / m for the st group ( difference of mean = 2.4 ; 95% ci 1.76.5 ; p < 0.001 ) .
the duration of anesthesia with stb was 72.8 24 min in the ot group and 72.5 29.5 min in the st group ( p = 0.96 ) .
the volume of injected anesthetic was 6.4 0.6 ml in the ot group and 6.6 0.6 ml in the st group ( p = 0.07 ) .
there were 6 patients with mild chemosis and redness in the ot group and 15 patients in the st group .
the pain scores during delivery of the stb was 0.65 0.92 in the ot group and 0.95 0.98 in the st group ( p = 0.6 ) .
the akinesia scores at 5 and 10 min after stb in each group is presented in figure 3 . although the akinesia score was higher at 5 min compared to 10 min in both groups
, there was no statistically significant difference in stb using the different cannulas ( p > 0.05 all comparisons ) .
the lid movement score at 5 and 10 min following delivery of stb in both groups is presented in figure 4 .
the lid score was not significantly different between the groups at both time points ( p > 0.05 , all comparisons ) .
the lid at 5 and 10 min after stb did not statistically differ in each group ( p > 0.05 , all comparisons ) .
surgeon perception of the ability to perform surgery due to good anesthesia was 9.28 1.64 for the ot group and 9.53 1.27 for the st group ( p = 0.35 ) .
the pain score was 0.53 0.93 in the ot group and 0.23 0.7 in the st group ( p = 0.05 ) .
ophthalmic regional anesthesia has been traditionally performed with sharp needles for peribulbar and/or retrobulbar blocks .
patients with myopic globes , thin sclera and staphyloma , pose a higher risk of hemorrhage and globe perforation during insertion of a sharp needle .
stb is a safer alternative technique that not only avoid to penetrate a more vascular peribulbar area but also uses a blunt cannula instead of a sharp needle to avoid this complication .
different types of cannulas are currently used for stb , but st cannula is considered the gold standard .
mather compared a simple 20-gauge intravenous cannula to st and has found it equally effective .
better akinesia scores have been reported with the jacob cannula because of its shape has a definite endpoint compared to the standard cannula , which does not have a well - defined end point .
we compared the ot cannula , which is basically a surgical cannula and is meant to free the intraocular and the capsular bag adhesions during cataract surgery .
we used it for the first time for stb because of its similarity in shape and size with the standard st cannula .
the primary outcome of our study suggests that the ot cannula is as effective as the conventional st cannula for stb . in the current study ,
the overall quality of blocks was similar in both groups , irrespective of the type of cannula used .
the lower number of patients with complications such as chemosis and hemorrhage in the ot group ( a secondary outcome of our study ) , suggests that the ot cannula may also mitigate ocular damage compared to the st cannula during stb .
we assumed that the oval bulb at the end of the ot cannula during insertion into the sub - tenon 's space may have separated the tissues and fibrous bands ( if present ) more gently , compared to the st cannula , despite the similar outcome in both groups .
in addition , the smaller gauge of the ot cannula may have added another safety factor because needle gauge has been associated to the risk of trauma during peribulbar anesthesia in patients who were at higher risk for hemorrhage .
hence , we speculate that in addition to the equal efficacy , an ot cannula may also be safer than the st cannula because of the smaller gauge . the main limitation of our study is the type of patient population that is referred to our hospital .
simple cataract cases usually undergo surgery at local hospitals in the kingdom of saudi arabia , but complicated cases are referred to our hospital . based on this observation
, the ease of access to sub - tenon 's space at the inferotemporal quadrant could vary in eyes that had undergone previous surgeries . in this study , information on previous ocular surgery was limited , and the effect of this variable could not be evaluated .
however , the randomized , prospective , double - masked nature of this study does mitigate some of the drawbacks of this study .
the ot cannula seems equivalent to the gold standard steven 's cannula ( st ) for stb during cataract surgery .
there were greater complications such as chemosis with the st cannula compared to the ot cannula .
further studies on larger patient groups are warranted before the recommending switching to the ot cannula for sub - tenon 's ocular anesthesia .
| ### Summary:
: purpose : to compare the efficacy of the olive tipped ( ot ) cannula to the conventional steven 's cannula for sub - tenon block ( stb ) before cataract surgery.methods:this prospective , randomized , double - masked compared stb delivered in cataract surgery patients with an ot cannula or a conventional steven 's cannula ( st ) .
outcome variables included the akinesia score and lid movement scores at 5 and 10 min .
the patient perception of pain during delivery of the stb and surgery were also compared between groups .
surgeon satisfaction with anesthesia was compared between groups .
p < 0.05 was statistically significant.results:there were sixty patients in each group .
the age between groups was not statistically different ( p = 0.4 ) .
the body mass index was higher in the st group compared to the ot group ( p < 0.001 ) . the akinesia score at 5 and 10 min did not differ between groups ( p = 0.07 and p = 0.6 , respectively ) .
the patient perception of pain during stb and surgery were similar between groups ( p = 0.1 and p = 0.06 , respectively ) .
there were six patients with mild chemosis and redness in the ot group and 15 patients in the st group.conclusion:an ot cannula is equally effective as the conventional steven 's cannula for delivering stb anesthesia before cataract surgery . |
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: growing skull fracture occurs following head injury in the first 3 years of life , particularly in infancy .
progressive diastasis of the fracture line with underlying dural tear results in herniation of arachnoid through the fracture line and formation of a cyst .
the watertight dural closure is standard treatment recommended early in the course of fracture development .
remote site intracranial hemorrhage following surgery for growing skull fracture is a serious , life - threatening complication which has not yet reported in the literature .
a 12-year - old girl presented with progressively increasing swelling over the right forehead since the age of 4 years .
she had received symptomatic treatment for the head injury and had made an uneventful recovery .
six months after the head injury , she had repeated seizures which were not very well controlled on antiepileptic drugs .
magnetic resonance imaging of the brain demonstrated the right frontal leptomeningeal cyst which was similar to cerebrospinal fluid ( csf ) intensity on all sequences [ figure 1a c ] .
the cyst was also seen extending into right orbit through a defect in orbital roof [ figure 1d ] .
computed tomography ( ct ) of the brain demonstrated right frontal bone defect with the expansion of the outer and inner table at the edge of bone defect [ figure 1e and f ] .
the next day she underwent right frontal craniectomy , and the dural defect was identified .
cranioplasty was done using polymethyl methacrylate bone cement ( depuy international limited , johnson and johnson , united kingdom ) . as the patient did not wake up from anesthesia , emergency ct scan
was performed which revealed remote site right temporoparietal hematoma with intraventricular extension [ figure 2a ] .
the external ventricular drain was placed in right lateral ventricle and craniotomy was done to evacuate the hematoma .
medium pressure chabbra ventriculoperitoneal shunt was inserted . at the end of 6 weeks , during discharge , her glasgow outcome scale was 3 which remained unchanged on follow - up at 3 months .
magnetic resonance imaging of the brain demonstrates a right frontal leptomeningeal cyst similar to cerebrospinal fluid intensity on all sequences ( a - c ) .
the cyst is in communication with the right lateral ventricle with septations within it ( c ) .
the cyst is seen extending into right orbit through defect in orbital roof ( d , arrow ) .
computed tomography of the brain shows right frontal bone defect with expansion of the outer and inner table at the edge of bone defect ( e and f ) computed tomography scan of the brain performed after surgical repair of growing skull fracture reveals remote site right temporoparietal hematoma with intraventricular extension ( a ) .
a growing skull fracture is an extremely unusual but known neurological complication of pediatric head injuries .
it commonly manifests as progressively enlarging scalp swelling following skull bone fracture involving dural tear .
the early surgical intervention involves performing craniectomy , repair of the dural defect , and closure of the bone .
the occurrence of remote site hemorrhage , i.e. , hemorrhage occurring at a distant site from the neurosurgical site , either on ipsilateral or contralateral site , is an extremely unusual complication resulting in significant morbidity or mortality .
remote site intracerebral hemorrhage following surgical repair of growing skull fracture has not been reported in literature until date .
the most likely explanation is an extensive loss of csf from basal cisterns during supratentorial surgery results in sagging of the cerebellum with stretch on superior vermian vein causing hemorrhage .
another possible theory is the occurrence of craniocephalic disproportion due to hydrocephalus . in the presence of hydrocephalus
greater is the craniocephalic disproportion ; larger is the potential for development of intracranial hemorrhage as in the present case . in this case , the growing skull fracture was seen to be in communication with the lateral ventricle .
remote site intracranial hemorrhage occurred due to sudden , rapid as well as substantial loss of csf from the lateral ventricles .
this lead to sagging of the ipsilateral cerebral hemisphere and stretching of the ipsilateral bridging veins , i.e. , vein of labbe with resultant tear leading to hemorrhagic venous infarct .
the occurrence of greater craniocephalic disproportion due to excess csf in the ventricles and the cyst could also be a contributing factor . the only probable way to reduce the risk of occurrence of this life - threatening complication in large ,
tense growing skull fracture communicating with the ventricle is to prevent acute decompression of the ventricles and the cyst .
insertion of ventriculoperitoneal shunt would inadvertently , result in a gradual reduction in intracranial pressure .
this would prevent rapid , sudden brain shift thereby avoiding avulsion of the bridging veins .
delayed diagnosis , large bone defect , delayed repair , and occurrence of life - threatening complication lead to a poor outcome in the present case .
remote site hemorrhage is a potentially fatal complication in large , tense growing skull fractures which communicate with the ventricles .
ct of the brain needs to be performed in patients who do not recover from anesthesia or those who deteriorate in the postoperative period .
slow drainage of csf by placement of ventriculoperitoneal shunt is likely to cause a gradual reduction in intracranial pressure , thereby minimizing the chances of occurrence of this unusual complication .
| ### Summary:
: growing skull fracture is an extremely rare complication of pediatric head injury , especially in infants .
repair of the dural tear early in the course of development of growing skull fracture has been suggested for a better outcome
. surgical repair of large , tense growing skull fractures , especially those in the communication of the ventricles can lead to potentially life - threatening complications .
the author reports a rare case of remote intracranial hemorrhage following surgery for large , tense growing skull fracture in a 12-year - old girl and discusses the likely pathogenesis and possible ways to avoid this life - threatening complication . |
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: a 75-year - old brazilian woman was admitted to the hospital do servidor pblico estadual de so paulo on may 5 , 1999 , with progressive memory loss , confusion , and involuntary movements in the upper right arm after a fall 1 year earlier .
she had also developed gait disorder , with short steps and constant loss of balance that led to a diagnosis of parkinson s disease in a neurology consultation in march 1999 ; however , the condition did not respond to the usual treatment .
on april 30 , a computed tomographic ( ct ) scan of the brain showed multiple lesions in both brain hemispheres , after which the patient was referred to the hospital .
past clinical history showed an evaluation of productive cough in 1996 , with bloody sputum , night sweats , and intermittent fever ; she underwent bronchoscopy with pathologic examination , which showed vascular congestion and focal intra - alveolar edema , but no specific pathogen was identified . on examination ,
the patient appeared chronically ill , mildly pale , disoriented , and confused , although she was able to follow simple commands .
cultures were negative for aerobic and anaerobic bacteria and mycobacteria , and two samples were positive for a fungus , tentatively identified as aspergillus sp .
the patient was initially treated for 21 days with ceftriaxone , oxacillin , and metronidazole without major improvement .
when the fungus was isolated , she was treated with amphotericin b and underwent postdrainage magnetic resonance imaging ( mri ) of the brain , which showed multifocal brain abscesses , including subtentorial and supratentorial lesions ( figure 1 ) . a chest x - ray and a ct scan of the thorax showed a small , bilateral pleural effusion and a left pulmonary cavitary lesion .
left pleural drainage obtained 80 ml of a clear yellow pleural effusion with ph 7.5 , 19,870 leukocytes / ml and 970 erythrocytes / ml , with negative cultures for mycobacteria , aerobic and anaerobic bacteria , and fungi .
refractory hypokalemia developed after the patient received a total dose of 1 g of amphotericin b , which led to discontinuation of this drug .
a course of amphotericin b plus itraconazole ( 400 mg / day ) was initiated . magnetic resonance imaging ( mri ) of the brain obtained after first drainage . on the first day of itraconazole therapy , another mri of the brain
was performed , which showed an increase in the volume of the abscesses . during the next few days , the patient s mental state worsened , and she had another cerebral drainage 8 days later . a yellowish opaque liquid , with a white granular deposit , was obtained from the frontal and parietal abscesses .
all cultures were negative for bacteria but positive for the same fungus that had been isolated previously .
her clinical and neurologic status improved , and she was discharged to a nursing home on july 20 , 1999 ; itraconazole ( 400 mg / day ) treatment was continued .
the patient was again admitted to the hospital on august 8 , and she stayed for 21 days after being diagnosed with urinary sepsis caused by escherichia coli .
she was last seen at the outpatient clinic on september 29 , with an unchanged neurologic condition . during the hospital
stay , another mri of the brain showed a decrease in the size of all lesions , which was interpreted as a good response to the itraconazole therapy . because of the difficulties of maintaining home care , she was admitted to another nursing hospital .
her clinical state deteriorated , and she died in november 1999 from multiple organ failure .
clinical information on this last hospital admission is very limited , and a postmortem examination was not performed .
cultures obtained on the two occasions yielded molds with identical morphologic features , and one isolate was referred to the medical school of rovira i virgili university in reus , tarragona , spain , for identification purposes .
the isolate was subcultured on czapek agar and malt extract agar ( mea ) , and incubated at approximately 25c in the dark .
after 14 days , the colonies on czapek agar were very restricted ( 12 mm14 mm in diameter ) , velvety , irregularly folded , umbonate , and white to yellowish white , with a pale yellow reverse .
the colonies developed rapidly , attaining a diameter of 40 mm46 mm in 14 days .
they were velvety , radially folded , white to greenish white , with a pale yellow reverse .
the microscopic features of ascomata and conidial heads were examined from wet mounts prepared in lactic acid under a light microscopy .
ascomata were non - ostiolate , superficial , white to light cream colored , globose or subglobose , measuring 120 m600 m in diameter , and covered with a white aerial mycelium .
the asci were eight - spored , more or less globose , and measured 11m15 m in diameter .
the ascospores were hyaline , one - celled , and lenticular , with two closely pressed equatorial crests .
they measured 6 m7.5 m x 4 m5 m , including the crests , and their convex walls showed a fine reticulate ornamentation .
the conidiophores consisted of green to bluish green , uniseriate , short columnar conidial heads over hyaline to light green , smooth and thick - walled stipes , which measured 100 m170 m x 3 m4 m . the conidia were pale greenish , globose or subglobose , 2 m2.5 m in diameter and with smooth or delicately roughened walls . on the basis of the above characteristics , and especially taking into account the ascospore ornamentation observed under scanning electron microscopy ( figure 2 ) , we identified the isolate as n. hiratsukae ( 10,11 ) .
the isolate was morphologically compared with the type strain of n. hiratsukae ( nhl 3008 ) and was proven to be the same species ( figure 2a , b ) .
in addition , n. hiratsukae is the only species of neosartorya with reticulated ascospores that grow restrictedly on czapek agar , a characteristic also shown in the case isolate .
n. pseudofischeri , the most common neosartorya species involved in human infections , is easily distinguished because its ascospore walls are ornamented with raised flaps of tissue resembling triangular projections or long ridge lines ( figure 2c ) .
living cultures of the case strain are deposited in the centraalbureau voor schimmelcultures , the netherlands ( cbs 109356 ) and in the institute of hygiene and epidemiology , belgium ( ihem 18438 ) .
ascospores of neosartorya hiratsukae , cbs 109356 ( a ) and nhl 3008 ( b ) , and of n. pseudofischeri , nrrl 3496 ( c ) , under scanning electron microscopy . bars a , b , c = 1 m .
tests were carried out by a microdilution method described previously ( 12 ) and adapted from the reference method for molds recommended by the national committee for clinical laboratory standards ( 13 ) , with rpmi 1640 medium buffered to ph 7.0 with 0.165 m morpholinepropanesulfonic acid , an inoculum of 9.1 x 10 cfu / ml , an incubation temperature of 30c , a second - day reading ( 48 h ) , and an additive drug - dilution procedure .
mics and minimum fungicidal concentrations ( mfc ) were as follows : amphotericin b 1 and > 16 g / ml , flucytosine 64 and > 64 g / ml , itraconazole 0.25 and 0.25 g / ml , voriconazole 0.25 and 0.5 g / ml , and ur-9825 0.06 and 0.5 g / ml , respectively .
mfcs of amphotericin b and flucytosine were very high , indicating the ineffectiveness of these drugs .
these data correlate with our clinical results since a total dose of 1 g of amphotericin b was unable to reduce the brain abscesses , while the patient responded well to itraconazole at daily doses of 400 mg .
that produce white colonies and do not become green , like colonies of a. fumigatus , are often discarded as contaminants .
many neosartorya species , other than n. fischeri or n. pseudofischeri , are thermotolerant and can grow at temperatures above 37c , showing their inherent ability to invade the brain . | ### Summary:
: we report the first case of infection by neosartorya hiratsukae , an ascomycete in which the conidial state resembles aspergillus fumigatus . the fungus caused a brain infection in a brazilian woman , who died despite itraconazole treatment .
diagnosis was established by direct microscopic examination , computed tomographic scan , and magnetic resonance imaging of the brain , and repeated cultures from the lesions .
the in vitro antifungal susceptibility of the isolate is provided . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: during resident programs , residents are required to develop knowledge , technical skills , patient communication skills , and advanced social skills to facilitate interactions with co - workers1 ) .
the united states orthopaedic in - training examination ( us oite ) was carried out in 1963 by the american academy of orthopaedics234567891011 ) . in - training
examination is an important method of assessing the knowledge of residents , determine minimal knowledge standards in training programs and develop appropriate programs for residents preparing for the korean board of orthopaedic surgery certification examination . in - training examinations for various orthopedic topics
, medical residents can analyze their strengths and weaknesses in medical knowledge , and hospitals can utilize these results to evaluate their curricula and develop better alternatives712 ) .
previous studies of the us oite classify questions by general topic , question type or reference , compare residents ' performance by grading , and analyze the correlation between the us oite and the actual examination6813 ) .
the korean orthopaedic in - training examination ( koite ) , produced by the korean orthopedic association ( koa ) , was first performed in 1980 .
each year , a sitting the koite , a score sheet is provided to all residents through faculty members in their hospital .
this allows faculty members to compare resident education and knowledge as well as to find study source for the korean board of orthopaedic surgery certification examination .
however , insufficient analyses of the koite have been performed , and no study has focused on the hip and pelvis section .
therefore , this study aimed to analyze the hip and pelvis section of the koite to identify patterns in question content , recommended references and facilitate development of appropriate teaching programs .
a total of 500 questions were examined , 75 of which were in the hip and pelvis section ( fig .
1 ) . the contents were analyzed and categorized according to topic , imaging modality , taxonomic classification , and references .
topics were classified as trauma ( including fracture and dislocation ) , disease , anatomy , and basics ( hip joint arthroplasty , hip joint biomechanics , and physical examination ) .
sub - topics were classified as biomechanics , anatomy , physical examination , fracture / dislocation , periprosthetic fracture of the femur , arthroplasty , arthroscopy , pelvic osteotomy , osteonecrosis of the femoral head , legg - calv - perthes disease ( lcp ) , slipped capital femoral epiphysis ( scfe ) , femoro - acetabular impingement ( fai ) , piriformis syndrome , transient osteoporosis of the femur , etc .
the questions were also divided according to taxonomic classification as described by buckwalter et al.14 ) and frassica et al15 ) .
simple - recall or knowledge questions ( taxonomy 1 ) involve recollection of facts without specific cognitive problem - solving . diagnosis - type questions ( taxonomy 2 ) involve deduction using given information such as clinical history and radiologic examination results .
evaluation and decision - making questions ( taxonomy 3 ) require the examinee to establish a diagnosis and treatment plan using the information provided in the question .
the imaging modalities were simple radiographs , magnetic resonance imaging / magnetic resonance arthrography , computed tomography ( ct)/ct arthrography , and clinical photographs .
the standard of reference is determined by whether it is possible to infer the answer based on the contents of the reference . since the koa publishes the koa textbook of orthopaedics ( 7th edition ) , campbell 's operative orthopaedics ( 12th edition ) , rockwood and green 's fractures in adults and children ( 7th edition ) , the american academy of orthopaedic surgeons instructional course lecture ( icl of aaos ) , and the journal of korean orthopaedic association ( jkoa ) and clinics in orthopaedic surgery ( cios ) journal as reference books for medical residents , this study used the same standard .
finally , the total average score of the examination and the average score of the hip and pelvis section were obtained using the score sheet , and the results were analyzed in terms of their difficulty .
the overall weight of the hip and pelvis section of the koite was 15.0% ( 75 of 500 questions ) for 5 years ( fig .
the most frequently asked questions were about fracture and dislocation ( 26/75 , 34.7% ) , followed by basics ( 23/75 , 30.7% ) , disease ( 21/75 , 28.0% ) , and anatomy ( 5/75 , 6.7% ) ( fig .
2 ) . a greater number of questions focus on disease . in terms of sub - topics , questions related to fracture and dislocation ( 25/75 , 33.3% ) and arthroplasty ( 20/75 , 26.7% )
were the most commonly asked , and every year at least one question covered anatomy , periprosthetic fracture of the femur , osteonecrosis of the femoral head , and arthroscopy ( table 1 ) .
basic descriptive questions were the most frequently asked ( 63/75 , 84.0% ) , and questions including visual materials ( such as figures , graphs , and videos ) were asked at a relatively constant rate ( fig .
simple radiographs were provided most commonly , ( 6/12 , 50.0% ) followed by videos , clinical photographs , and ct images ( fig .
the most common types of question were about an appropriate treatment plan ( taxonomy 3 , 39/75 , 52.0% ) , followed by simple knowledge ( taxonomy 1 , 29/75 , 38.7% ) and diagnosis ( taxonomy 2 , 7/75 , 9.3% ) .
of the 46 questions regarding appropriate diagnosis and treatment , the largest proportion provided a basic description without a figure ( 38/46 , 82.6% ) , among which 20 questions described a physical examination ( 20/38 , 52.6% ) and 4 physical examination and laboratory results ( 4/38 , 10.5% ) .
of the four questions , two addressed hip joint infection and the other two osteoporosis and venous thromboembolism .
the most commonly cited reference was campbell 's operative orthopaedics ( 52/75 , 69.3% ) , followed by the koa textbook of orthopaedics ( 16/75 , 21.3% ) , rockwood and green 's fractures in adults and children , and the jkoa and cios ( table 2 ) .
the total average score of the koite of second to fourth grade residents was nearly 50 points between 2010 and 2014 , and the degree of difficulty remained constant . also , the average score of the hip and pelvis section of the koite maintained similarity with the total average score , but showed higher average scores in 2012 and 2013 , unlike the overall trend ( fig .
the koite began in 1980 , but few analytical or descriptive studies have been conducted .
two papers focused on the shoulder and elbow section and the hand and wrist section1617 ) . as faculty members and orthopedic surgeons at teaching hospitals in the hip and pelvis surgery subspecialty ,
our interest in training of orthopedic residents and the role of the koite led us to perform this study .
this is the first study to analyze the questions of the hip and pelvis section of the koite during a 5-year period ( 2010 to 2014 ) .
the examination comprised total of 500 questions from 2010 to 2014 , which were divided into 11 domains : hand , shoulder and elbow , spine , hip , infection and metabolism , foot , trauma , pediatrics , tumor , basics and rehabilitation . of these , the hip and pelvis section comprised 75 questions ( 15.0% ) . according to previous reports ,
5.8% of the questions during the same period were in the shoulder and elbow section and 12.2% in the hand and wrist section1617 ) .
although further analysis of other anatomic regions is required , the hip and pelvis section occupies a relatively large proportion .
furthermore , questions relating to the hip and pelvis section are asked every year at a relatively constant rate ( 12 - 18% ) . in terms of topic
, questions related to trauma including fracture and dislocation occupied the largest proportion ( 26/75 , 34.7% ) , as reported by kim et al.17 ) for the hand and wrist section of the koite .
however , unlike the hand and wrist section , questions about basics ( 23/75 , 30.7% ) were as frequent as those regarding trauma . among the questions regarding basics ,
therefore , arthroplasty is one of the most important components of further training , together with fracture and dislocation . regarding question sub - types , anatomy ,
periprosthetic fracture of the femur , arthroscopy , and osteonecrosis of the femoral head were asked almost every year due to their importance .
moreover , all of the four questions regarding periprosthetic fracture of the femur dealt with fracture management after total hip arthroplasty , and from 2011 to 2014 the five questions about osteonecrosis of the femoral head dealt with treatment , with the exception of one question in 2010 , which dealt with diagnosis . therefore , an understanding of the appropriate diagnosis , classification and treatment plan of these two subtopics is required .
of the questions , 84% were of the simple descriptive type , as reported previously for the hand and wrist section17 ) .
furthermore , taxonomy 2 and 3 , which inquire about appropriate diagnosis and treatment , were most frequently asked using descriptive text , without images or videos ( 82.6% ) .
these types of question seem inappropriate for current medical circumstances , which require a comprehensive method of diagnosis and treatment that takes into account the results of examination and medical imaging .
therefore , such questions seem inadequate for evaluating the residents ' critical thinking , and a question format that nurtures inferential thinking should be developed .
the total average koite scores from 2010 to 2014 were around 50 points , suggesting that the difficulty of the examination was constant .
also , the average score of the hip and pelvis section was around 50% , similar to the total average score , but the average scores in 2012 and 2013 were higher than the total average scores in those years .
the examination in 2012 comprised only basic descriptive - type questions , which lacked visual materials .
furthermore , the examination in 2013 included a larger proportion of basic descriptive - type questions compared to those in other years .
although the other parts of the koite were not analyzed , the data suggest that the average score of the hip and pelvis section increases with an increasing proportion of basic descriptive - type questions in the examination . the most frequently cited references were campbell 's operative orthopaedics ( 69.3% ) and the koa textbook of orthopaedics ( 21.3% ) , which indicates that enough questions are not based on the jkoa and cios despite the koa recommendation . according to previous reports
, regular journal meetings can improve residents satisfaction with their education and increase the educational value of teaching hospitals13 ) , and in the us oite , 59% and 10% are from papers published within the last 5 and 1 years , respectively18 ) .
this indicates that frequent journal meetings can enable residents to acquire the latest knowledge , thereby achieving educational goals and maximizing performance .
therefore , there is a need to reference the science citation index ( sci ) and sci expanded ( scie ) journals in future examinations .
this is the first study to analyze the questions in the hip and pelvis section of the koite .
first , the validity of the koite was not sufficiently evaluated because the examination was not analyzed according to residents ' scores .
a future study should involve analysis of not only residents ' scores by grade but also the effect of changes in the questions on the residents ' scores .
second , not all past examinations were analyzed comprehensively because only a 5-year period of the 35 years of the examination was analyzed .
third , comparison of the characteristics of the hip and pelvis section with other sections is problematic because of the lack of studies addressing the latter .
further studies should analyze the trends in each section , which will enable establishment of an appropriate training curriculum .
the koite committee decided to use tablet pcs for the examination , to facilitate provision of images and videos .
therefore , the effect of use of tablet pcs on residents ' scores and question types should be evaluated .
the dearth of analyses of the koite to date indicates that the effort to evaluate the propriety of training education and improve assessment of medical residents has been inadequate .
this study provides information relating to the content and recommended references in the koite hip and pelvis section .
this information will provide orthopedic trainees , orthopedic residency programs , and the korean orthopedic board examination committee valuable information , which will improve resident knowledge and performance and optimize the hip and pelvis educational curriculum . | ### Summary:
: purposethe purpose of this study was to analyze the questions in the hip and pelvis section of the korean orthopaedic in - training examination ( koite).materials and methodswe analyzed all koite questions pertaining to hip and pelvis surgery between 2010 and 2014 .
a thorough analysis of the contents was performed after categorizing as tested topics , imaging modalities used , taxonomic classification , and recommended references .
we also analyzed the scores of the hip and pelvis section of the koite.resultsseventy-five of five - hundred questions ( weight , 15.0% ) were related to the hip and pelvis .
trauma including fracture and dislocation ( 26/75 , 34.7% ) was asked more commonly than disease and basics . the description - only questions ( 65/75 , 86.7% )
were the most frequently asked .
according to taxonomic classification , taxonomy 3 ( decision ; 39/75 , 52.0% ) was most frequently asked .
campbell 's operative orthopedics ( 52/75 , 69.3% ) was the reference that covered most of the questions.conclusionthis analysis of the hip and pelvis section of koite could be used for resident training programs in teaching hospitals . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: t. cruzi infects the vertebrate host through bite wounds produced in skin by a feeding bug or through the interaction of the parasite with conjunctival mucosa .
the histology of this initial site of infection is defined by an elevated number of mononuclear cells .
this first sign of infection suggests that t. cruzi can stimulate skin cells to produce mediators that trigger a local inflammatory response . despite controversies about the mechanism of the pathogenesis of chagas disease [ 25 ] ,
until recently , some authors believed that the disease was limited to an acute phase , followed by a chronic phase that was considered an autoimmune disease , where the parasites would be physically linked to sites of inflammation in the heart and esophagus [ 68 ] .
however , nowadays , the disease is considered multifactorial , with multiple and continuous interactions between pathogen and host . after the incubation period of 2 to 3 weeks , infection with t. cruzi
is manifested by the presence of a large number of parasites in the blood and tissues .
acute infection is accompanied by an excessive activation of the immune system that includes the production of high levels of cytokines , intense activation of t and b cells , lymphadenopathy , splenomegaly , and intense inflammation associated with tissue infection niches .
the acute phase induces the development of an effective acquired immunity leading to the control of parasitemia .
the chronic phase is considered lifelong and is associated with only a few parasites in the host .
however , with the advance of the disease , clinical manifestations become variable , ranging from no symptoms to the involvement of cardiovascular and/or gastrointestinal symptoms [ 10 , 11 ] . before the acquired immunity
is established , the innate immune system appears to be essential for at least two important aspects of chagas disease : control of replication of the parasite in the host tissue and progress of the inflammatory reaction .
the latter , in turn , has been considered to be the main cause of tissue damage and dysfunction of certain organs in the host .
some studies in experimental models of infection of t. cruzi suggest that the potent immune response to th-1 cd4 and cd8 cells , with the production of specific inflammatory cytokines , such as interferon gamma ( ifn- ) , tumour necrosis factor ( tnf- ) , and interleukin 12 ( il-12 ) , as well as the production of reactive nitrogen species such as nitric oxide ( no ) , plays an important role in the control of parasitemia during the initial stage of the disease [ 4 , 1013 ] .
moreover , cells of innate immunity , such as natural killer ( nk ) cells , dendritic cells , and macrophages , are also key elements in the initial control of parasite replication [ 1013 ] . in recent years ,
research on chagas disease has focused on the investigation of the role of pathogen - associated molecular patterns ( pamps ) of protozoa , which are the targets of innate immune receptors .
also , the problem of identifying relevant receptors in innate immunity - parasite interactions during the evolution of the disease in the host has been addressed by several laboratories .
this strategy ultimately aims at the development of therapeutic interventions through the use of pamps derived from parasites .
glycosyl - phosphatidyl - inositol ( gpi ) is the name given to the first glycoconjugate in t. brucei that was identified with the function of anchoring proteins on the cell surface [ 1417 ] .
all evolutive forms of this parasite express on their surface gpi - anchored glycoproteins [ 1417 ] .
some studies have identified gpi anchors isolated from trypomastigote - derived mucin - like glycoproteins ( gpi - mucins ) of t. cruzi as the molecules primarily responsible for stimulating the host immune system [ 18 , 19 ] .
thus , t. cruzi gpi - mucins are able to activate macrophages and stimulate the production of proinflammatory cytokines , chemokines , and no [ 2022 ] .
innate immune response to t. cruzi has been studied extensively and is based on the activation of signaling pathways triggered by toll - like receptors ( tlrs ) .
tlrs are proteins that recognize conserved motifs associated with several different pathogens ; they trigger intracellular signaling cascades that ultimately lead to a complex host immune response [ 11 , 12 ] .
there are 10 tlrs described in humans and 12 in mice [ 11 , 12 ] .
generally , the stimulus induced by gpi molecules occurs during the early phase of infection , where macrophages respond to trypomastigotes in a tlr - dependent mechanism and ultimately induce the production of il-12 and tnf- and trigger the responses of cd4 and cd8 cells through the production of ifn- .
thus , macrophages activated by tnf- and ifn- seem to have an important role in controlling parasite growth .
free gpi anchors or glycoinositolphospholipids ( gipls ) are also able to stimulate the host immune system .
gipls are similar to gpis but contain instead ceramide in their lipid moiety [ 18 , 19 ] .
tlrs 2 , 4 , and 9 are the major tlrs involved in innate immune response to t. cruzi [ 18 , 2429 ] .
tlr2 has been identified as the main receptor responsible for macrophage activation by gpi mucins [ 18 , 2429 ] . according to ropert and gazzinelli ,
the receptor heterodimer composed of tlr2 and trl6 is activated by gpi mucin and the cd14 coreceptor .
oliveira et al . observed that gipl from t. cruzi confers an inflammatory response via tlr4 , promoting the recruitment of neutrophils into the peritoneal cavity of mice .
later , medeiros et al . demonstrated that this effect was partially dependent on the production of il-1. the genomic dna of t. cruzi also plays an important role in proinflammatory response of the vertebrate host during infection , since tlr 9 is activated by cpg motifs from nonmethylated dna [ 28 , 29 ] .
besides the innate immune response mediated by tlrs , t. cruzi can also stimulate tlr - independent pathways that lead to the production of ifn- and ifn-. in this case , this occurs due to a surge in intracellular calcium concentration which ultimately leads to the activation of calcineurin and calmodulin [ 3032 ] .
lysophospholipids such as lysophosphatidylcholine ( lpc ) , sphyngosylphosphoryilcholine ( spc ) , lysophosphatidic acid ( lpa ) , and sphingosine-1-phosphate ( s1p ) regulate a large number of cellular processes .
lpc is a derivative of phosphatidylcholine ( pc ) that arises by the loss of a fatty acid through the action of a phospholipase a2 ( pla2 ) or by transferring it to cholesterol by the action of a cholesterol - acetyltransferase .
lpc is involved in several physiological events and is already known as a central molecule in several pathological states , but it is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque [ 3436 ] .
research directed towards lpc has increased greatly since the finding that these molecules are involved in atherosclerosis .
the idea that various phospholipases secreted by circulating leukocytes participate in this pathology was soon proposed .
thus , the current model suggests that diabetes and hypercholesterolemia contribute to generate a large number of ldl particles in plasma that can undergo oxidation of unsaturated fatty acids , generating an oxidized particle ( oxldl ) . since on average 50% of ldl fatty acids are arachidonic acid and linoleic acid , the chances of such an oxidative event are huge .
the oxldl is a potential cause of the increased expression of inflammatory markers such as tnf- , mcp-1 , and mcsf that will attract differentiating monocytes to the lesion site . in this sense , lpc is one of the most powerful chemotactic signals for macrophages and is also generated by cells in the apoptotic process as mentioned above .
oxldl particles are recognized by various secretory pla2 in the plasma , including type iia , v , and x. our group showed for the first time the presence of phospholipids and lysophospholipids in saliva and feces of the hematophagous organism rhodnius prolixus , a triatominae bug vector of chagas disease .
salivary lpc is an additional antihemostatic molecule that is part of the pharmacological arsenal injected into the bite site to allow the insect to feed .
thus , lpc was initially described as a molecule with antiplatelet and vasodilatory activities , and a few years later , its effect as an immunomodulator of t.cruzi infection was demonstrated [ 38 , 39 ] . the role of lpc as a modulator of t. cruzi transmission occurs by three main mechanisms summarized on figure 1 and mentioned as follows .
it acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite .
this event will provide a concentrated population of cells available for t. cruzi infection [ 38 , 39 ] .
( 2 ) lpc increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion . ( 3 ) lpc inhibits no production by macrophages stimulated by either live t. cruzi , lps , or lps in the presence of ifn- , and thus interferes with the immune system of the vertebrate host .
the above findings demonstrate that lpc is now a signaling molecule with effects beyond that of counteracting host blood hemostasis , since it acts as modulator of no biology and parasite transmission [ 4043 ] .
macrophages are intimately related to the establishment of acute infection with t. cruzi , since the success of the infection depends on the initial invasion of these cells [ 4446 ] .
this leads to the assumption that salivary lpc may facilitate the parasite infection , favoring not only insect feeding , but also preparing the environment for the arrival of the parasite , minutes or hours after the initial bug bite .
recent results obtained by our group demonstrated that injection of salivary lpc into host skin followed by parasite inoculation in the same site minutes later ultimately increases blood parasitemia from 3- to 6-fold in animals infected with t. cruzi .
lpc 's effect on parasitemia is mainly achieved by the activation of macrophage chemotaxis and immunosuppression of no production induced by the parasite .
we also showed an increase in the rate of association of the parasite with macrophages induced either by 500-fold diluted saliva or by lpc .
this was the first demonstration of a potentiating factor of transmission of chagas disease and the first implication of a lysophospholipid in an infectious disease .
the activation of receptors that recognize the parasite by the presence of specific structures on its surface stimulates host cells to produce tnf- , il-12 , and no , as mentioned above . depending on the myd88 adapter protein ,
tlrs 2 , 4 , and 9 have been implicated in the network used by the immune system of the mammalian host to control infection by t. cruzi [ 1418 ] .
campos et al . [ 18 , 23 ] were the first to demonstrate the involvement of tlr2 in the interaction between the parasite and host macrophages .
the expression of tlr2 is essential for the induction of il-12 , tnf- , and no , and this receptor is activated by parasite - derived molecules such as gpi anchors , which have been isolated from the surface of trypomastigotes of t. cruzi [ 1418 ] .
the production of no but not il-12 by t. cruzi - exposed macrophages is not affected by bug saliva .
curiously , in bone - marrow - derived macrophages obtained from tlr2-deficient mice , the production of il-12 is largely suppressed by lpc .
these data indicate that in some cell types , the production of this cytokine may be affected by this lysophospholipid through a tlr2-independent mechanism .
moreover , gipls from t. cruzi are tlr4 agonists with proinflammatory effects [ 25 , 26 ] .
we showed that no production , induced by the parasite or by lipopolysaccharide ( lps ) , another ligand of tlr4 , either in murine peritoneal macrophages or bone marrow - derived macrophages , is blocked in both cases by lpc even in the presence of ifn- in vitro .
the ability of lpc to reverse the induction of no production in all cases , almost independently of the ligand type , suggests that this lysophospholipid must act by a unique pathway . in this regard ,
the receptors involved in cell signaling induced by lpc , in general , exhibit a certain promiscuity with respect to the ligand and vice versa . in the case of lpc ,
different receptors have been proposed for this molecule , including g2a , a g protein - coupled receptor , and gpr4 , another important candidate [ 45 , 4749 ] . despite the controversy generated in the literature due to the low reproducibility of the studies using radioactive lpc and its interaction with candidate receptors ,
thus , g2a remains in the literature as the best - known receptor involved in the adaptation of the signal induced by lpc [ 4749 ] .
moreover , the redistribution of g2a receptor itself and the exposure of tlr4 are influenced by lpc metabolism [ 33 , 50 ] . in this case , the content of intracellular lpc is finely controlled by the activity of a lysophosphatidylcholine acyltransferase ( lpcat ) , an enzyme that uses lpc as a substrate and generates phospholipids as the product of its action .
the treatment of monocytes with lps activates this enzyme and increases the transport of tlr4 to membrane rafts in these cells .
since the lpcat inhibitor used , 5-hydroxyethyl 53 thiophenol pyridine ( hetp ) , increases the lysophospholipids / phospholipids ratios , it reverses the effect of lps .
thus , it seems appropriate to propose that in the presence of t. cruzi , one should conduct a map of the distribution of both receptors , g2a and tlr4 , in the presence and in the absence of lpc using both proteomic and immunological methods [ 33 , 50 ] . during programmed cell death , lpc is generated by a calcium - independent pla2 activated by caspase-3 .
thus , lpc acts as a chemotactic find - me signal that attracts the phagocyte to the apoptotic cells [ 49 , 51 , 52 ] and as an eat - me signal involving recruitment of complement proteins for recognition by phagocytes [ 49 , 51 , 52 ] .
such lpc - induced chemotaxis is very interesting , because in chagas disease , the uptake of apoptotic cells by macrophages infected with t. cruzi stimulates parasite growth . in addition , it has been shown that t. cruzi infective stages are able to generate lipid messengers , including lpc , that modulate host cell signaling .
regarding adaptor molecules mobilized in response to lpc , it is known that in most cell types , there is the involvement of isoforms of protein kinase c .
probably it is the type of isoform activated in each cell that directs the intensity and type of response triggered by lpc in that specific cell type .
when combined with different types of tlrs and adapters , lpc - mediated signaling must produce a specific and still poorly understood repertoire of immunosuppression .
pla2 is an enzyme family present in various organisms such as viruses , bacteria , plants , and animals . according to studies done on mammals ,
the action of pla2 is important for the remodeling of cell membranes , lipid digestion , cell signaling , and immune defense of the host as well as production of various lipid mediators [ 5661 ] . in insects ,
the phospholipases that have been studied are related to the venom injected into their prey , the physiology of digestion , immunity , and reproduction . among the published studies on phospholipase activity in arthropods are those reporting the presence of such enzymes in the salivary glands of manduca sexta and in the saliva and salivary glands of amblyoma americanum [ 63 , 64 ] .
in addition , zhu et al . suggested another role for this activity , linking it to the production of prostaglandins , promotion of vasodilation and the suppression of inflammation and immunity .
the production of prostacyclin may also lead to the inhibition of platelet aggregation and the induction of vasodilation .
furthermore , platelet - activating factor ( paf ) acetyl hydrolase , a member of the gvii family of pla2 enzymes , is a serine - dependent hydrolase that does not require ca for activity .
this enzyme cleaves the acetyl group from the sn-2 position of the phospholipid , and in the case of paf , there is the hydrolysis of the sn-2 ester bond , releasing acetate and biologically inactive lyso - paf [ 65 , 66 ] .
cat flea ( ctenocephalides felis ) salivary gland homogenate has a paf - acetylhydrolase activity , and the estimated amount of activity in a single pair of salivary glands ( ~5 pmol / min ) is of the right order of magnitude to induce a localized anti - inflammatory / allergic effect .
extracellular paf is proinflammatory and acts via very high affinity g - coupled protein receptors , causing activation of platelets , neutrophils , and monocytes .
the hypothesis is that paf - acetylhydrolase activities from saliva can downregulate inflammatory and immune reactions mediated by paf released from host cells .
this may happen as a reaction to injected cat flea saliva and may be interrupted by host grooming or scratching the locale of the bite .
besides these reports , phospholipases also have been identified in transcriptomes of saliva or salivary glands of some hematophagous arthropods such as the soft ticks ornithodoros coriaceus [ 67 , 68 ] and o. parkeri , of hard ticks such as ixodes pacificus , and in insects such as anopheles funestus , phlebotomus arabicus , and glossina morsitans .
zeidner et al . have suggested that aside from facilitating some tick digestive processes , it is possible that secretion of pla2 into the feed site creates some protective barrier against bacteria that can be carried into the wound .
they demonstrated that the borreliacidal activity found in a. americanum saliva is most probably due to the enzymatic effects of pla2 and that it would directly and rapidly kill borrelia burgdorgeri through the digestion of membrane lipids , composed by a majority of pc and phosphatidylglycerol .
the authors hypothesize that high level of pla2 enzymatic activity present in saliva is related to a. americanum 's refractoriness to b. burgdorgeri .
other studies have demonstrated the importance of pla2 in the infection processas elicited by pathogens such as toxoplasma gondii , cryptosporium parvum , entamoeba histolytica , leishmania amazonensis , and t. cruzi [ 7577 ] . moreover , connelly and kierszenbaum showed that the presence of pla2 significantly increased the association between t. cruzi and macrophages , and they suggest that this effect relies on alterations of the parasite membrane , since it was induced by pretreatment of parasite membranes with pla2 but not macrophages . but nowadays , as cited above , the presence of pla2 in salivary secretions of t. cruzi vectors implies lpc generation and its further involvement in the inflammatory process that occurs during infection .
pla2 enzymes from snake venom induce a wide spectrum of pharmacological effects , including anticoagulant proprieties that can be mediated by hydrolysis of phospholipid or by a nonenzymatic mechanism , such as when pla2 from naja nigricollis venom binds factor xa in the coagulation cascade through the specific anticoagulant site on its surface .
our group is investigating a further role for the lpc present in the saliva of vectors , which we believe is related to muscular paralysis .
have shown that lysophospholipids , in particular lpc , can block the exocytosis of neurotransmitters , thus paralyzing the muscle . in this context , using the predator insect belostoma anurum as model , we showed that the salivary lpc also has this property .
our hypothesis is that b. anurum uses lysophospholipids as a way to paralyze the prey while it feeds , since it makes an extraoral digestion .
we obtained similar results with lpc from r. prolixus , with less pronounced blockage of exocytosis .
thus , the above data show that the presence of lpc generated by pla2s in salivary secretions of predators and blood - sucking arthopods is widespread in the animal kingdom , and this molecule may be a surviving trace of ancient feeding habits .
another aspect that should be emphasized is that pla2s also generate free fatty acids that can be converted to eicosanoids .
eicosanoids are polyunsaturated fatty acids of 20 carbons that act as local mediators of short half - life ; they are derived from arachidonic acid ( 20 : 4 n-6 ) or other polyunsaturated 20-carbon precursors ( 20 : 3 n-6 and 20 : 5 n-3 ) .
arachidonic acid is esterified in phospholipids of plasma membranes , these being released by the action of pla2 .
the biological action of arachidonic acid products requires its oxygenation , which can take place in three different ways : ( a ) via the cyclooxygenases that generate prostaglandins and thromboxanes , ( b ) via the lipooxygenases that generate leukotrienes and lipoxins , and ( c ) via the cytochrome p-450 , which generates epoxides .
physiological processes that usually involve autacoids , hormones , and growth factors may stimulate the release of arachidonic acid , as already widely described in mammals , as in mediating immune and inflammatory response of late vertebrates .
recently , the involvement of thromboxane a2 ( txa2 ) in the process of vertebrate host infection by t. cruzi was demonstrated . the same group showed that the eicosanoid txa2 is prevalent in all life stages of the parasite .
thus , in infected mice , the parasite itself may account for 90% of the total txa2 in plasma . in this regard , it is noteworthy that the production of txa2 from arachidonic acid occurs by the cyclooxygenase pathway .
accordingly , results from our laboratory indicate that half of the fatty acids ingested along with blood are unsaturated and about half of them are arachidonic acid .
so , if a pool of txa2 is a prerequisite for the process of infection of host cells by any pathogen , that pool could be generated during the final stages of blood digestion in the vector at the expense of fatty acids released there .
a triacylglycerol - lipase activity was identified in the gut lumen of blood - fed insects and is probably involved in the digestion of lipids from the blood meal .
these lipase activities and also the metabolism and fate of lipids that are generated during digestion of ingested blood were studied and characterized . however , neither the dynamic generation of free fatty acids in insects infected with t. cruzi nor their processing to txa2 in the final stage of the digestive process has ever been assessed in any vector .
thus , an attractive model for the future might involve the silencing of a pla2 gene in the saliva of chagas disease vectors to obtain lpc - depleted or lpc - free saliva .
the saliva of these insects would be expected to lower the rate of infection of the vertebrate host .
the original studies that implicated lpc in the pathogenesis of atherosclerosis tended to highlight the presence of this phospholipid in atheromatous lesions .
however , the origin and dynamics of the formation of this molecule remained unknown for many years .
wilensky et al . identified the main enzyme responsible for the generation of lpc , lp - pla2 , also known as paf - acetyl hydrolase or phospholipase viia , which is secreted by leukocytes and associated with plasma lipoproteins , especially ldl .
this enzyme recognizes and cleaves oxldl and oxidized phospholipids , generating lpc and free fatty acid oxidation ( oxnefas , or oxidized nonesterified fatty acids ) .
the lpc , as previously mentioned , is a potent proinflammatory molecule capable of leukocyte recruitment and activation with induction of apoptosis .
demonstration of lp - pla2 in the necrotic core of atheromatous lesions and fibrous cap of vulnerable plaques supports our current views of the importance of this enzyme in atherogenesis .
wilensky et al . showed that the administration of darapladib ( glaxosmithkline ) in experimental models selectively reduces the activity of this enzyme , attenuates the formation of lpc , and reduces the formation of atherosclerotic plaques with negative regulation of proinflammatory genes in macrophages and t lymphocytes .
chagas disease treatment aims to slow the progression of myocardial impairment caused by invasion of the patient 's heart by the parasite .
some of the drugs used to treat chagas disease cause changes in the patients plasma lipid profile , leading to high concentrations of ldl . during treatment
, these patients are likely to present favorable conditions for ldl oxidation and generation of lpc , which will certainly trigger the proinflammatory phenotype , thereby maintaining levels of reinfection of myocardial cells . in this sense
, it would be important to evaluate the generation of lpc in chagas disease patients treated with various categories of drugs in order to verify the formation of this lipid mediator .
likewise , chronic treatment with the drug in healthy experimental animals should be carried out to identify any effects on the levels of lpc and subsequent susceptibility to infection by t. cruzi . in conclusion
, darapladib may constitute a novel tool with dual use : to optimize the current therapeutic treatment of chronic chagasic patients and to experimentally modify the plasma levels of lpc in mice to determine whether the reduction of such levels decreases the susceptibly to infection by t. cruzi . | ### Summary:
: lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque .
such molecule is also present in saliva and feces of the hematophagous organism rhodnius prolixus , a triatominae bug vector of chagas disease .
we have recently demonstrated that lpc is a modulator of trypanosoma cruzi transmission .
it acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite , which will provide a concentrated population of cells available for parasite infection .
also , lpc increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion .
finally , lpc inhibits no production by macrophages stimulated by live t. cruzi , and thus interferes with the immune system of the vertebrate host . in the present paper , we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of chagas disease . |
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: in urology departments approximately one third of the operations are performed for urinary stone management , most of them using less invasive procedures .
percutaneous nephrolithotomy ( pcnl ) is one of such procedures and is more common in academic hospitals , . over the last decade ,
although complications after pcnl are common , 80% are often minor and 20% are major including septicemia , bleeding , and damage to lung and colon , .
little is depicted on neurological complications following pcnl in the literature , , , , . in our center , we encountered complaints of ipsilateral abdominal wall and upper thigh numbness after pcnl .
regarding to the wide application of this procedure , investigation on its less - known complications seems fruitful .
thus , this study was designed to determine the frequency and risk factors of neurological defects following pcnl .
in a cross - sectional study data of pcnl cases from february 2011 to july 2011were included .
comprehensive neurological physical examination considering neural dermatomes was carried out before the surgical operation on both sides by a single neurologist .
the patients with unilateral neuropathy and asymmetrical pre - operation neurological examination were excluded from the study .
the position of the patient during operation , operation time , number of the tracts used and preoperation and first day post - operation hemoglobin were registered , too . on 10 day after operation neurologic physical examination was repeated by the same neurologist and the type of nervous engagement and the name of the nerve engaged were described .
all patients underwent general anesthesia and 2 surgeons carried out operations ( one prone and one supine positions ) .
ureter stent was inserted at the beginning of the procedure in all patients and remained during hospitalization .
the nephrostomy tube was inserted at the end of procedure , but in supine was not due to surgeon preference .
rigid nephroscope and pneumatic lithoclast were used during procedures . none supracostal tract access was used and none of the patients was in uremia status .
then , data were analyzed by chi - square , fisher s exact and independent t test using software spss18 .
out of 68 patients who underwent pcnl from february 2011 to july 2011 , three were excluded because of asymmetric neurologic examination before operation . from the rest ( 30 males and 35 females ) with a mean age of 47.9 11.47 , eight patients ( 4 male and 4 female ) had abnormal neurologic examination on 10day after operation ( table 1 ( tab .
1 ) ) . according to the table , the most prevalent engaged dermatome were sub - abdominal dermatomes specially t12 .
one patient suffered paresthesia and dysesthesia of t10 - 11 - 12 dermatomes and ilioinguinal nerve , sensory branch of femoral nerve and lateral cutaneous nerve of thigh .
the sensory disorders observed in patients consisted of hypoesthesia , paresthesia , dysesthesia and/or a combination of several disorders as given in details in table 2 ( tab .
2 ) . no other nervous system lesions ( including obturator , genitofemoral nerves and brachial plexus ) , motor lesion , paraplegia or visual defects were observed . according to table 3 ( tab .
3 ) , only operation time and hemoglobin drop was statistically different between the two groups .
mean hemoglobin rate among the patients suffering neurological problems before and after pcnl were 14.04 1.28 and 10.18 1.83 mg / dl respectively ( versus the asymptomatic group of patients having the rate of 13.21 1.55 and 11.34 2.21 before and after pcnl ) .
no significant correlation between the emergence of sensory neurologic problems and other factors were observed .
in the literature , postsurgical neuropathies have been reported after various operations such as aortic surgery , appendectomy , inguinal hernia repairment and radical perineal prostectomy , , . thigh numbness and femoral nerve damage after kidney transplantation and lower limbs neuropathies after gynecological surgeries have been shown too .
heterogeneous causes have been assumed for these disorders including ischemia , hematoma pressure , positioning , diabetes , patient s thinness , duration of operation and application of retractor , , , .
these neuropathies may lead to pain , morbidity , reduction of the quality of life , economical problems and legal complaints , , .
flank incision is accompanied by complications such as pain , intercostals neuropathy , and incisional hernia in 8% to 50% of cases , , , and even testicular pain has been reported . therefore , small and smaller incisions replace large ones .
one of such procedures is pcnl which makes access to kidney through dilatation . although reports mentioning femoral neuropathy , lumbar hernia , blindness , brain emboli and neurological defects after this procedures exist . at our institution cases
were observed in which ipsilateral abdominal wall and upper thigh numbness , tenderness , and sometimes pain occurred after pcnl despite minimal invasive nature of the procedure .
so we designed this study to determine prevalence and risk factors of neurological defects after pcnl .
sensory neurological complications ( touch and needle perception decrease ) in intercostals and lumbosacral plexus area occurred in 8 patients ( 12.31% ) , in which gender distributed equally .
there was a significant correlation between prolonged duration of surgery and prevalence of sensory complications .
no other nervous system lesions including motor lesion , paraplegia or visual defects were observed , so we can consider these sensory neuropathies as grade i of clavien system .
our study failed to reveal a meaningful correlation between patients age , dm , hypertension , tracts used , positioning of patients and side of surgery with incidence of sensory neurological deficits . regarding the finding that the commonest nerve involved was t12 ,
the effect of pcnl access on intercostals nerves and vessels have been studied and lateral access was found to produce the most damages
. direct nervous plexus trauma in minimal invasive pcnl procedure may occur and direct lumbar plexus trauma has been reported in pelvic kidney pcnl . although retroperitoneal imaging was not done in our study , another justification for neuropathy following pcnl is retroperitoneal blood accumulation and pressure effect on the nerves .
perinephric hematoma following pcnl has been reported in 30% of cases , and even may lead to kidney displacement .
the relation between retroperitoneal hematoma and femoral neuropathy has been shown previously , and there are similar studies on lateral cutaneous nerve of thigh , .
the hgb drop and duration of surgery which has been correlated to neuropathy following pcnl can be regarded as an indicator for surgical trauma and hematoma formation .
urinoma formation and irrigation fluid accumulation have been reported in 27% of cases and may have similar effect as hematoma .
some specialists believe that inflammatory or autoimmune factors have some influence on postsurgical neuropathy and also lumbosacral damage following total hip arthroplasty and bilateral sciatic neuropathy following radical nephrectomy has been described .
although , positioning has been found to be a risk factor in postoperative neuropathies , prone or supine position was not different in our study ( table 3 ( tab .
3 ) ) . we did not observe motor lesion in patients but it may be due to small sample size as a single center study .
the time of onset and end of damages were not investigated which can be considered as another limitation of study .
we must consider this study as a preliminary one that should be pursued by larger multicenter analytic surveys .
prolonged procedure duration and increased value of hemoglobin drop may lead to increased risk of neuropathy .
larger prospective analytic studies with retroperitoneal imaging and patients longitudinal follow - up are suggested for better understanding of this complication .
| ### Summary:
: introduction : postoperative neurological complications in pelvic and renal surgery are a well - known clinical problem and their morbidities are important . we designed this study to determine prevalence and risk factors of such complications after percutaneous nephrolithotomy ( pcnl ) surgery.material and methods : a cross - sectional study was performed during february and july 2011 on 68 pcnl cases .
demographic data and surgery reports were gathered and comprehensive neurological physical examination carried out before and after surgery .
then , data was analyzed using software spss 18 .
results : the ultimate sample included 30 ( 46.2% ) male and 35 ( 53.8% ) female patients with a mean age of 47.9 11.47 years . in intercostal and lumbosacral plexus area ,
sensory neurological complications occurred in 8 patients ( 12.31% ) , 4 men and 4 women .
the most common involved dermatomes and nerves were t12 ( 8 cases ) .
there was a significant correlation between prolonged duration of surgery and prevalence of sensory complications ( p<0.010 ) .
the highest hemoglobin value drop after surgery occurred in patients with neurological complications ( p<0.001 ) .
there were no correlations between age , tracts used , diabetes mellitus , bmi , hypertension , positioning of patients and side of surgery with incidence of sensory neurological complications .
no motor neurological complications occurred .
conclusion : prolonged duration of pcnl and increased value of hemoglobin drop may lead to increased risk of neuropathy .
larger prospective studies with retroperitoneal imagings and patients follow up is suggested for better understanding of this complication . |
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: proteins are complex molecules and often unstable when they are placed out of their native environment .
proteins or enzymes may also lose their activity as a result of high temperature , aggregation , proteolysis , and suboptimal solution conditions .
the purified proteins are often unstable and need to be stabilized in order to maintain the structural integrity and activity .
protein aggregation during processing and formulation is one of the major setbacks that limit the rapid commercialization of protein - based pharmaceuticals .
proteins aggregation is usually triggered by the formation of partially unfolded intermediates and therefore the demand for successful stabilization protocol is progressively increasing .
the phenomenon of stabilization of proteins infers the preservation of the native protein structure and activity during storage .
the protein stabilization is based on the principle of limiting the molecular motion and conformational transition while maintaining the protein still in the native state [ 2 , 3 ] .
the native structure of a protein is dictated by various intramolecular interactions and its contacts with the surrounding solutes and solvents .
several sugars and polyols have extensively been used to stabilize the proteins against denaturation and to extend their shelf life during storage [ 4 , 5 ] . the structural stability of a protein in an aqueous solution
the interactions between solvent , cosolvents , and protein have often been explained in terms of transfer free energy , preferential interaction parameters and preferential interaction coefficients [ 6 , 7 ] .
probably , the idea to stabilize the protein by using natural cosolvents must have come from the fact that many living organisms accumulate a number of osmolytes in response to adverse environmental stress conditions , which usually act as molecular crowders in the cytosol .
mounting evidences suggest that begins from archaebacteria to mammals , several mechanisms are evolved to protect the cells when they are subjected to hypertonic or stress conditions .
a recent report indicates that accumulation of compatible osmolytes provides a protective mechanism that can easily trigger the expression system specific for uptake of the osmolytes from the environments [ 9 , 10 ] .
it is likely that the behavior of an enzyme may be substantially different when it is sequestered in cytosol loaded with osmolytes and other macromolecular crowders , compared to the enzyme suspended in normal buffer . when an activity assay of an enzyme is performed in diluted buffer condition
, it essentially does not correspond to large cytosolic macromolecular crowding environment and the observed activity may not be identical to its cytosolic counterpart . according to zimmerman and trach , the total protein concentration in an e. coli cell is use to be > 300 mg / ml , which is equivalent to > 30% ( w / v ) . such high concentration of macromolecules along with other available osmolytes may have critical effect on both conformation and catalytic activity of an enzyme .
the mechanisms of cosolvent - induced effect on proteins are frequently explained in terms of preferential interactions and change in thermodynamic parameters , and the cosolvent - induced minor structural fine - tunings are often ignored .
it is important to consider that the biological activities of enzymatic proteins are functions of minor conformational transitions .
a protein under macromolecular crowding conditions may acquire a minor shift in the structure ; nevertheless , such structural rearrangement could have an impact on its function . considering the above perspectives , an attempt was made to investigate the effect of macromolecular crowding on activity and structure of a model enzyme .
addition of natural cosolvents ( such as polyols and sugars ) to the enzyme solution may imitate the conditions of macromolecular crowding to a certain extent that enable us to understand the possible effect on protein function .
to explore this idea -amylase ( from bacillus amylolequifaciens ) was used as a model enzyme ( as its structure is well known ) in this investigation .
the catalytic activity and thermal stability of the enzyme were examined in the presence of different concentrations of trehalose , sorbitol , sucrose , and glycerol .
-amylase ( endo 1,4--d - glucan glucanohydrolases , ec : 3.2.1.1 ) randomly cleaves the -d-1 , 4-glycosidic bonds in starch with retention of -anomeric configuration in the end product .
it consists of three separate domains called domains a , b , and c and with specific ( /)8 barrel , also known as tim ( triose phosphate isomerase ) that forms the core of the enzyme molecule .
domain b is formed by a protrusion between third -strand and third helix of ( /)8 barrel and it is rich in structure .
the c domain constitutes c - terminal part of the sequence and forms a greek key motif .
the function of domain c is not fully known yet , but the mutation in this domain suggests that it has a vital role in enzymatic catalysis [ 14 , 15 ] .
the criteria for selection of these cosolvents were based on their solubility at higher concentration , biological compatibility and inertness towards any possible covalent interaction with protein molecules .
-amylase type ii ( from bacillus amylolequifaciens ) , trehalose , sorbitol , sucrose , glycerol , starch , dinitrosalisylic acid , bovine serum albumin ( bsa ) , sodium azide , and cacl2 were procured from sigma chemicals company , usa .
spectrapore dialysis membrane ( mwco , 6 kda ) was procured from spectrum , houston , usa .
the crystalline -amylase was dissolved and dialyzed in 0.02 m citrate buffer , ph 5.9 to remove additives , freeze - dried ( 80c ) , and desiccated at 20c for future use .
stock solutions of cosolvents and enzyme were prepared in 0.02 m sodium citrate buffer , ph 5.9 .
then the enzyme was incubated in different concentration ( ranging 040% , w / v ) of each cosolvent ( trehalose , sorbitol , sucrose , and glycerol ) at 10c for 48 hours with gentle agitation on a magnetic stirrer .
after 48 hours of incubation , all the enzyme samples were centrifuged at 10000 rpm , at 4c , for 20 min and supernatants were collected while leaving bottom 10% of its volume to avoid any precipitate .
if required the enzyme samples were diluted to required concentration in the respective buffers or cosolvents solutions , before measuring activity , thermal stability , intrinsic fluorescence , and far uv - cd .
all the solutions were supplemented with 0.005% ( w / v ) of sodium azide to avoid bacterial contamination and it did not show any inhibitory effect on the enzyme at this concentration .
-amylase activity was measured by using method of bernfeld for estimation of reducing sugar .
reaction mixture , containing 1 ml of 1% starch solution and 1 ml of the enzyme solution , was incubated for 5 min at 37c .
the reaction was terminated by addition of 2 ml of 1% alkaline dinitrosalicylic acid solution .
the whole solution was then subjected to heat in boiling water bath for 10 min .
after cooling the solution was diluted five times using triple distilled water , mixed properly , and absorbance was recorded at 540 nm .
one unit of -amylase was defined as amount of enzyme required to hydrolyze starch to produce 1 mol of reducing sugar ( maltose ) under given condition . in order to assess
the reversibility of cosolvent induced effect on -amylase , the enzyme activity was measured before and after removal of cosolvents .
the cosolvents from the enzyme solution were removed by using simple dialysis against buffer for 15 hrs at 10c to eliminate all the cosolvents added with several changes of buffer at every two hours . at the end carbohydrate analysis of the enzyme samples
the thermal inactivation of -amylase was carried out in the presence of cosolvents trehalose , sorbitol , sucrose , and glycerol , using final concentration of the enzyme as 1 g / ml . the enzyme solutions were incubated at 60c for 10 min and transferred onto ice and allowed to stand for 30 min before the enzyme activity was measured at 37c . assuming a simple two - step phenomenon for the irreversible thermal inactivation process , the half lives ( t1/2 ) of the enzyme ( at 60c ) , in the presence of different cosolvents were calculated from the slope of the inactivation curves obtained by linear regression of residual activity versus incubation time .
t1/2 is defined as the time required to irreversibly reducing 50% of the enzyme activity under given condition .
intrinsic fluorescence spectra of -amylase ( 50 g / ml ) were recorded at 25c in the presence of different concentrations of cosolvents in a shimadzu spectrofluorophotometer model rf-5000 , equipped with temperature - controlled water bath .
the fluorescence excitation wavelength was set at 280 nm and emission spectra were recorded in the range of 300400 nm using slit width of 10 and 5 nm for excitation and emissions respectively .
each spectrum represents an average of three independent scans . the far uv - cd measurements of the enzyme in the presence of 30% ( w / v ) concentrations of cosolvents were carried out in the far - uv region ( 200260 nm ) on a jasco spectropolarimeter model j-810 at 25c .
the cd scan was performed by using 0.26 mg / ml of the enzyme with path length of 1 mm and 50 nm / min scan speed . the observed ellipticitiy
was expressed as mean residue ellipticity ( mre ) in deg - cm dmol .
thermal stability of -amylase was studied in the presence of four selected cosolvents , sorbitol , sucrose , trehalose , and glycerol .
the rate of thermal inactivation of enzyme was significantly reduced in the presence of cosolvents .
the stabilization effect of all the cosolvents was estimated by measuring t1/2 of the enzyme at 60c .
all the cosolvents were found to have significant effect on stability of the enzyme against temperature - induced inactivation .
the effectiveness of each cosolvent was found to be linearly enhanced with increasing the concentration .
the enzyme lost 50% of its activity after 5 min of incubation at 60c . in the presence of various cosolvents
the t1/2 value was found to be increased several folds and the increment was dependent on the concentration of cosolvents used ( figure 1 ) .
although addition of all the four cosolvents was found to be useful in reducing the rate of thermal inactivation of the enzyme , trehalose was found to be most effective . at 40% concentration ,
trehalose displayed 58-fold enhancements in t1/2 of the enzyme compared to 32 fold , 56-fold , and 35-fold in the presence of sucrose , sorbitol , and glycerol ( figure 1 ) , respectively .
although the increase in thermal resistance of the enzyme appeared attractive , it was not surprising as the enhancement in the thermal stability of various enzymes and proteins in the presence of cosolvents is well documented previously [ 1921 ] .
however , the simultaneous observation of the cosolvent - mediated enhancement in the catalytic activity of the enzyme was unexpected .
the cosolvent - induced enhancement in activity was further noticeable when the activity was measured at higher temperatures , as shown in figure 2 .
moreover , a shift in the temperature for optimum enzyme activity was also observed , at least , in the presence of sucrose and glycerol .
as shown in figure 2 , the enzyme in buffer has optimum activity around 50c . in the presence of cosolvents
the enhancement in the enzyme activity was found to dependent on the concentration of each cosolvent used , at least in the range of 1040% ( w / v ) .
this finding could be of vital importance in the processes where the enzymatic activity is carried out at higher temperature ( e.g. , starch saccharification and liquefaction , temperature reaches up to 70100c ) .
table 1 lists the activity of the enzyme before treatment with cosolvents and after their removal from enzyme solution .
after removal of cosolvents the enzyme activity was found to be nearly identical to the enzyme without any treatment . after having observed the effect of cosolvents on the enzyme function and stability , a curiosity developed to investigate the biophysical properties of the enzyme in the presence of cosolvents .
the structural analyses of the enzyme in the presence of cosolvents were performed by using far uv - cd and intrinsic fluorescence measurement at ambient temperature .
the data from far uv - cd measurement indicate a minor change in the ellipticity in the presence of 20% ( w / v ) , as shown in figure 3 .
a slight negative increase in the peaks at 222 nm and 216 nm indicates a minor change in -helical and -sheet components .
the intrinsic fluorescence intensity of the enzyme was found to be slightly decreased in the presence of all the cosolvents as shown in figure 4 . in addition , an small shift in the emission maxima ( max ) was also observed at least in the presence of sucrose and sorbitol .
the max is an excellent parameter to monitor the polarity of tryptophan microenvironment in enzyme molecule and it is sensitive to change in protein conformation .
the max of -amylase in buffer was found to be 340 nm and it was found to be 336 nm and 337 nm in the presence of 40% ( w / v ) sucrose and sorbitol , respectively ( figure 5 ) .
a reduction in intrinsic fluorescence intensity and shifting of max towards lower wavelength indicate that the aromatic residues are being relocated in more hydrophobic environment .
together with far - uv - cd and fluorescence data it is clear that the presence of cosolvents makes some changes in the enzyme structure which may be accountable for tremendous effect on activity and thermal stability .
it is known that the cosolvents do not interact covalently with protein molecule but confer its stabilizing effect essentially by altering the physicochemical properties of solution , particularly in the vicinity of proteins . in principle , the effect of cosolvents on enzyme activity depends on cosolvent induced alteration in chemical potential of the enzyme .
it is generally noticed that the preferentially excluded cosolvents increase the chemical potential of protein .
such partitioning of protein and cosolvents in a solution is likely to alter the equilibrium of enzyme - catalyzed reaction .
such perturbing effect of cosolvents may include a number of processes such as binding of substrates , reversible structural changes , enzyme stability , change in hydration at protein surface , and so forth .
it is observed that the presence of cosolvents does not bring about any significant change in the secondary structure of the enzyme .
previous reports indicate that at room temperature , the enzyme is relatively hydrated and the cosolvents were preferentially excluded from the protein - water interface [ 20 , 23 ] .
this means that the surface of enzyme has more concentrated water molecules compared to the bulk solution and interaction of enzyme molecules with cosolvents is less preferred compared to water .
the preferential interaction properties are likely to alter with change in temperatures and therefore may influence the stability and function of the enzyme . although such partitioning does not change the structure of the enzyme to a great extent ( as evident from fluorescence and cd measurement ) , the preferential hydration may induce a tendency to repel the hydrophobic residues that are relatively present on protein surface , in the core regions to avoid thermodynamically unfavorable interactions with water .
this may add to increase the hydrophobic interactions , which subsequently enhance the structural stability of proteins .
such a minor structural readjustments may also persuade their effect on the electrostatics of the catalytic sites and render the enzyme to acquire more active state . from the above - described results it appears that the thermal stability of -amylase is significantly improved in the presence of cosolvents .
the alteration in the solvent composition due to presence of cosolvents has a positive outcome on the nature of interacting forces responsible for structural reorganization , which provide stability and catalytic efficiency to the enzyme .
this finding reveals that an enzyme under macromolecular crowding conditions continued to be catalytically more robust and stable compared to the one in isolation , despite the fact that they possess nearly identical structures . | ### Summary:
: in the present study an attempt was made to investigate the macromolecular crowding effect on functional attributes of -amylase .
high concentrations of sugar based cosolvents , ( e.g. , trehalose , sucrose , sorbitol , and glycerol ) were used to mimic the macromolecular crowding environment ( of cellular milieu ) under in vitro conditions . to assess the effect of macromolecular crowding ,
the activity and structural properties of the enzyme were evaluated in the presence of different concentrations of the above cosolvents .
based on the results it is suggested that the macromolecular crowding significantly improves the catalytic efficiency of the enzyme with marginal change in the structure . out of four cosolvents
examined , trehalose was found to be the most effective in consistently enhancing thermal stability of the enzyme .
moreover , the relative effectiveness of the above cosolvents was found to be dependent on their concentration used . |
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: intussusception is most commonly encountered in infants and children , although approximately 5% of cases occur in adults .
in fact , it accounts for an estimated 1% of all cases of bowel obstruction in adults .
. the diagnosis can be in emergency situations , with the aid of integrated examinations .
the association of readily available diagnostic means , such as radiological and ultrasonographic studies , may yield reliable findings [ 2 , 3 ] .
we herein describe a case of adult intussusception of the descending colon caused by a malignant tumor .
intussusception of the descending colon generally does not readily occur because the descending colon is anatomically fixed to the retroperitoneum .
moreover , this patient had undergone chemotherapy for lymph node recurrence of stomach cancer for about 4 years , which could not prevent colon cancer .
the progression of this patient 's condition seemed to indirectly suggest a difference in biological malignancy between stomach cancer and colon cancer .
a 74-year - old japanese man was admitted to our hospital for treatment of vomiting and abdominal pain on june 15 , 2011 .
physical examination revealed a temperature of 36.9c , blood pressure of 175/105 mm hg and a pulse rate of 65 beats / min .
clinical examination revealed a distended abdomen with provocative pain in the left upper quadrant and a palpable , fist - sized mass .
blood tests showed a slightly elevated c - reactive protein level of 1.15 mg / dl , although other tests , including tumor markers , were within normal limits .
the patient had a past history of distal gastrectomy for stomach cancer in december 2003 and was visiting our hospital for chemotherapy for lymph node recurrence around the aorta approved since march 2007 .
this patient underwent 12 courses of irinotecan ( 100 mg / m weekly for 3 weeks followed by 2 weeks of rest ) followed by 14 courses of s-1 ( 80 mg / m weekly for 4 weeks followed by 2 weeks of rest ) and 5 courses of paclitaxel ( 100 mg / m weekly for 3 weeks followed by 1 week of rest ) . computed tomography ( ct ) indicated that the lymph node recurrence had disappeared on june 1 , 2011 , resulting in a complete response . at his visit to our hospital
target mass in the descending colon , suggesting the existence of a tumor in the head of the intussusception ( fig .
we diagnosed his illness as intussusception of a colon tumor and performed emergency laparotomy . at surgery , the descending colon was intussuscepted into itself by the tumor .
the intussusceptum was easily isolated because the fixation between the descending colon and the retroperitoneum was relatively weak .
reduction of the intussusception was performed before the resection following anastomosis because of the shortness and tension in the neighboring colon .
the left colon , including the ischemic area and tumor , and regional lymph nodes were removed .
an end - to - end anastomosis was primarily fashioned between the transverse colon and sigmoid colon .
the postoperative course was uneventful , and the patient was discharged 14 days after surgery .
macroscopically , the surgical specimen contained a 5.3 3.5 cm protuberant tumor at the proximal edge of the 16-cm - long ischemic area in the descending colon ( fig .
microscopic examination revealed poorly differentiated adenocarcinoma with invasion into the subserosa and ischemic wall on the anal side of the tumor by hematoxylin - eosin staining ( fig .
the tumor was partially positive for chromogranin a , kit , and cd56 by immunohistological staining , resulting in an adenocarcinoma with neuroendocrine features ( fig .
most colon intussusceptions in adults are caused by malignant tumors , although other causes and idiopathic forms of intussusception have been reported .
these intussusceptions are frequently located in the flexible portions of the colon , for example the sigmoid colon or cecum [ 5 , 6 ] .
intussusception of the descending colon is rarer because the descending colon is anatomically fixed to the retroperitoneum .
incomplete fixation between the retroperitoneum and descending colon might result in the presently described condition .
few general surgeons encounter more than one or two patients with colon intussusception during their careers , and most cases are undiagnosed before surgery .
previous papers reported that ct is the most accurate imaging modality for diagnosing intussusception [ 1 , 2 ] .
the characteristic ct findings of intussusception include an early target mass with enveloped , eccentrically located areas of low density .
reduction of intussusceptions with suspected malignancy is not generally advisable because it may cause bowel perforation and tumor cell dissemination .
however , reduction may be advisable to accurately determine the range of resection for minimally invasive surgery . in our case
if the intussusception had been operatively reduced , it would have been difficult to anastomose primarily because of the shortness and tension in the neighboring colon .
it was thought that colon cancer in this case occurred during the past 3 years , because colonoscopic examination had revealed a normal study in 2008 .
on the other hand , our patient had received several kinds of chemotherapy for lymph node recurrence of stomach cancer for about 4 years and had obtained a complete response .
thus chemotherapy seems to be generally effective for both gastric cancer and colon cancer , but could not prevent colon adenocarcinoma in our case .
one reason could be the mixture of neuroendocrine features , because neuroendocrine carcinomas often show resistance to chemotherapy .
this is the first report of an intussusception caused by descending colon cancer incidentally diagnosed during chemotherapy for stomach cancer recurrence .
the progression of this patient 's condition also suggested a difference in the biological malignancy between stomach cancer and colon cancer .
| ### Summary:
: intussusception in adults is uncommon , and it is rare in the descending colon because of its fixation to the retroperitoneum . we herein describe a case of intussusception caused by descending colon cancer .
a 74-year - old man was admitted to our hospital for treatment of vomiting and abdominal pain .
he had undergone chemotherapy for lymph node recurrence of stomach cancer for about 4 years .
computed tomography revealed a
target mass with a tumor in the descending colon .
we diagnosed his illness as intussusception of a descending colon tumor and performed emergency laparotomy .
conservative resection was performed following anastomosis after reduction of the intussusception .
the tumor was pathologically diagnosed as poorly differentiated adenocarcinoma with neuroendocrine features . to the best of our knowledge ,
this is the first report of an intussusception caused by descending colon cancer incidentally diagnosed during chemotherapy for stomach cancer recurrence . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: hurthle cell thyroid tumors ( also called oncocytic or oxyphilic thyroid tumors ) are uncommon thyroid lesions . by definition ,
they are composed predominantly of follicular cells ( 75% or more ) with deeply eosinophilic cytoplasm on haematoxylin and eosin ( h&e ) stained sections . in the past
, it has been proposed that all hurthle cell neoplasms should be regarded as malignant or potentially malignant .
recently , these tumors have been divided into two categories : the benign oncocytic adenoma ( oa ) and its malignant counterpart , follicular oncocytic carcinoma ( oc ) , showing blood vessel invasion and/or capsular penetration .
oc is an uncommon thyroid malignancy , representing about 2 - 3% of all thyroid carcinomas .
some tumors may also have relatively small cells , high nucleus / cytoplasm ratios , and solid / trabecular architecture .
for such lesions , having one or more of these features but lacking unequivocal sign of malignancy , rosai and tallini have suggested the following terms : atypical hurthle cell adenomas / hurthle cell tumors of uncertain malignant potential ( hct - ump ) .
rosai and the chernobyl thyroid group of pathologists recommended , for tumors showing questionable capsular invasion , the term follicular tumor of uncertain malignant potential ( ft - ump ) if papillary thyroid carcinoma- ( ptc- ) type nuclear changes are absent and well differentiated tumor of uncertain malignant potential ( wdt - ump ) in case of questionable ( incomplete ) ptc - type nuclear changes .
several attempts have been made to support the distinction between follicular adenomas and carcinomas , including the oncocytic type , using clinical characteristics and immunohistochemistry .
sippel et al . found an association between tumor dimensions and risk of nodal positivity in patients diagnosed with an oncocytic thyroid tumor by preoperative fine needle aspiration ( fna ) biopsy .
similarly , erickson et al . showed that the larger the size of an oncocytic lesion , the higher the risk of malignancy .
many markers have been used to classify oncocytic neoplasms . among these , galectin-3 ( gal-3 ) , a -galactoside - binding protein involved in regulating cell - cell and cell - matrix interactions , is a very promising one and has been shown to represent a very helpful adjunct to fna biopsy of thyroid nodules .
regarding hurthle cell thyroid lesions , some authors have demonstrated a very good sensitivity ( 95.1% ) and specificity ( 88% ) for gal-3 as a marker for ocs .
furthermore , in combination with the marker hmbe-1 , they reported an excellent sensitivity for this panel ( 99% ) .
however , other papers [ 810 ] have suggested that gal-3 immunoreactivity is not restricted to malignant neoplasms but can also be detected in thyroid adenomas .
some investigators [ 511 ] have performed immunohistochemistry studies focusing their attention on proliferative activity ( ki-67 ) and found lower activity in oas compared to ocs .
moreover , other results have shown that high proliferative activity is evident only in hurthle cell carcinomas with clinically aggressive behaviour .
recently , studies have been performed to assess the role and diagnostic value of d - cyclins as diagnostic markers in cases of oncocytic thyroid lesions .
the cyclin d family plays a pivotal role in the regulation of g1/s - phase cell transition , and d - cyclins are overexpressed in different types of cancers .
cyclin d1 , for example , was found to be absent in normal thyroid tissue and was as effective as cyclin d3 ( 100% specificity ) in determining the behaviour of fna specimens suspicious for hurthle cell neoplasia .
both of the markers , however , showed a low sensitivity ; thus , the authors conclude that there should be increased suspicion for malignancy in indeterminate oncocytic lesions of the thyroid that overexpress cyclin d3 .
they concluded that the risk of malignant behaviour increases with the rate of cyclin d3-expressing cells .
. demonstrated that , in ocs , the accumulation of p27 ( kip1 ) is associated with cyclin d3 overexpression , suggesting that cyclin d3 is a helpful marker when the histology is unclear .
the aim of our study was to evaluate the hypothesis that a combination of tumor diameter and immunohistochemical expression of cyclin d3 and gal-3 is helpful in distinguishing between benign and malignant thyroid lesions .
we retrieved all cases of thyroid specimens from 1995 to 2007 matching the key words : oncocytic or oxyphilic or hurthle .
all cases of medullary and papillary carcinomas ( oncocytic variants ) were excluded . after registering the diameter of each specimen in the initial cohort of 96 cases , we excluded cases of hyperplastic nodules and oncocytic metaplasia and cases intermingled with poorly differentiated carcinomas .
all slides of the remaining 58 cases were reevaluated by investigator claudio cacchi ( cc ) .
only cases that clearly had capsular and/or vascular invasion ( ocs ) and cases that clearly did not have vascular and/or capsular invasion ( oas ) were chosen for further investigation .
we obtained a final group of 40 cases ( 14 ocs and 26 oas ) .
3 - 4 m slides were cut and stained for gal-3 ( monoclonal mouse anti - human ; clone 9c4 , dilution 1 : 100 , novocastra ) and for cyclin d3 ( monoclonal mouse anti - human ; clone dcs-22 , dilution 1 : 40 , novocastra ) to assess the percentage of positive tumor cells .
immunostains were developed according to an antigen retrieval treatment ( in citrate buffer at ph 6.0 ) using a biotin - free detection system ( en vision , dakocytomation ) .
each antibody was tested with external positive and negative control , and for gal-3 we also considered foamy macrophages to be an internal positive control . both gal-3 and cyclin d3 expression were assessed / evaluated by two independent investigators claudio cacchi ( cc ) and bruno mrkl ( bm ) , without knowledge of the clinic pathological status of the cases .
each slide was scanned at low power magnification ( 1.6 lens ) to assess the average percentage of tumor cells positive for each marker .
we considered true positive cells to be only those that showed nuclear reactivity for cyclin d3 and concomitant / simultaneous nuclear and cytoplasmic reactivity for gal-3 .
for gal-3 and cyclin d3 , cutoffs of 1% and 25% have been chosen to classify cases as positive [ 7 , 14 ] .
results from investigator claudio cacchi ( cc ) were used to evaluate the specificity and sensitivity of each antibody tested alone or in combination .
this study was performed according to the national rule , that is , law of hospitals in bavaria ( bayerisches krankenhausgesetz ) .
for the comparison of the results , the paired t - test or mann - whitney rank sum test was used , depending on the normality test .
all calculations were performed using the sigma plot 11.0 software package ( systat , richmond , usa ) . a kappa value ( )
was also calculated to estimate the interobserver agreement for both immunohistochemical evaluations ; an absolute difference of 10% in two measures was considered agreement .
the maximum diameter ( in cm ) of ocs was greater than in oas ( 4.1 2.3 versus 2 0.8 ) ( p < 0.001 ) .
the results of the investigators had good agreement for both gal-3 and cyclin d3 ( = 0.8 and 0.7 , resp . ) .
the mean values of gal-3 in ocs versus oas were ( claudio cacchi ( cc ) and bruno mrkl ( bm ) ) 25% 25% and 24% 26% versus 3% 8% and 6% 17% ( figures 1 and 2 ) .
the examiners ' results ( claudio cacchi ( cc ) and bruno mrkl ( bm ) ) showed a significant difference in percentage ( p value < 0.001 and 0.002 ) of positive tumor cells between ocs and oas .
the results for cyclin d3 are the following ( claudio cacchi ( cc ) and bruno mrkl ( bm ) ) : 46% 37% and 47% 33% in ocs and 8% 13% and 13% 17% in oas ( figures 3 and 4 ) .
the two evaluations also showed cyclin d3 overexpression in the ocs with respect to the oas ( p < 0.001 and p = 0.001 , resp . ) .
gal-3 as marker of malignancy showed a relatively good sensitivity ( 79% ) and specificity ( 81% ) .
although the sensitivity of cyclin d3 as a single marker was low ( 50% ) , its specificity was very high ( 96% ) .
a combination of the two markers ( gal-3 + or cyclin d3 + ) demonstrated excellent sensitivity ( 100% ) and a quite good specificity ( 81% ) .
for the ft - ump or the hct - ump cases , papotti et al . demonstrated that there is no benefit with gal-3 and hbme-1 immunoprofiling .
herein we studied only cases with either certain benignity or certain malignancy . regarding tumor dimensions
, we described an important difference in the mean diameter of ocs ( 4.1 cm ) in comparison to oas ( 2 cm ) .
in fact , erickson et al . reported a median diameter of 4.8 cm for ocs and 3.1 cm for oas .
furthermore , sippel et al . demonstrated that ocs are larger than oas ( 5.0 versus 2.7 cm ) , supporting the predictive role of neoplasm 's dimensions in cases of fna biopsy with examination of oncocyte cytoplasm . in these cases ,
no malignancy was found for lesions smaller than 2 cm . in our study , only two out of fourteen cases ( 14% ) in the oc group were < 2 cm ( 1.5 and 1.7 cm ) .
our results , in agreement with the literature [ 4 , 5 ] , underscore the importance of clinical information and/or macroscopic precision in such lesions .
the correlation between tumor diameter and risk of malignancy of oncocytic tumors of the thyroid suggests the hypothesis of time - related carcinogenesis , in which an oncocytic adenoma represents a premalignant lesion , and the ft - ump represents formae frustrae of carcinomas .
the results published by erickson et al . seem to support this hypothesis , showing a diameter of 3.7 cm for neoplasms of uncertain malignant behaviour ( umb ) , which is larger than adenomas but smaller than carcinomas .
the use of galectin-3 as an adjunct to routine diagnosis of follicular thyroid neoplasms has been previously demonstrated [ 6 , 18 , 19 ] .
however , other studies have found reactivity for gal-3 in adenomas [ 810 ] . a possible explanation for these discrepancies may be the presence of false positive reactivity for gal-3 due to biotin dependent detection systems .
for this reason , we used a biotin - free system ( en vision , dakocytomation ) . focusing on oncocytic cell tumors of the thyroid , volante et al . showed a 94.3% rate of gal-3 positive carcinomas and a 12% rate of gal-3 positive adenomas . in this study
, gal-3 had a sensitivity of 95.1% and a specificity of 88% , and if used in combination with hbme-1 , the sensitivity was 99% .
interestingly , another study illustrated a significant difference in immunostaining for gal-3 between ocs and oas ( 59% versus 7.1% ) .
this diversity of percentage in gal-3 immunostaining in our study is similar to the literature ; however , probably due to the relatively small number of carcinomas in our study , the specificity and sensitivity for gal-3 are lower than those previously reported .
factors that affect cell cycle machinery , recently well elucidated , also have been tested in oncocytic follicular thyroid lesions .
for example , mller - hcker showed a higher reactivity for p53 in oncocytic neoplasms of the thyroid ( 88% in ocs and 75% in oas ; eight of seventeen ocs but only three of twenty oas with reactivity in more than 10% of the cells ) and showed a higher cell proliferation in ocs than oas ( ki-67 : 76 and 12 cells per 10/hpf , resp . ) .
. suggested , on the basis of a higher ki-67 index in widely invasive hurthle cell carcinoma , that this marker may have a role in the diagnosis of hurthle cell thyroid tumors . in 2000 , erickson et al .
recently , a study performed on fna samples with oncocytic features using cyclin d3 and cyclin d1 as predictors of malignancy illustrated a very good specificity ( 100% ) but low sensitivity ( 32 and 79% , resp . ) .
the authors of this study adopted cutoffs of 6.5% and 7.5% to improve the predictive value of cyclin d1 and cyclin d3 , respectively , and they recommend combining the two markers to enhance this capability .
interestingly , troncone et al . demonstrated that increased p27 expression in oncocytic follicular carcinoma is a consequence of cyclin d3 overexpression and suggested that cyclin d3 was a valid immunohistochemical marker for distinguishing ocs from oas in cases of unclear histology .
although translocation t(6 ; 14)(p21.1 ; 32.3 ) or amplification of the cyclin d3 gene is observed in different neoplasms , the mechanism of the overexpression of cyclin d3 in ocs is still unclear and further investigation in this direction is needed .
our study is the first that combines dimension , a nuclear marker ( cyclin d3 ) , and a nuclear - cytoplasmic marker ( gal-3 ) to differentiate oncocytic carcinomas and adenomas .
because of the possibility of a focal reaction for gal-3 in adenomas and to avoid the risk of using a very low threshold value , we did not use a cutoff in evaluation of this reaction . on the other hand , we believe that adopting a cutoff of 25% for cyclin d3 is quite easy to perform and reduces the interobserver variability in routine practice .
our results on the cyclin d3 expression in tumor cells are in accordance with those shown by troncone et al .
, with a low interobserver variability ( = 0.7 ) . in conclusion , our study , which was performed in a well - selected series of follicular oncocytic thyroid tumors , indicates that the combination of gal-3 and cyclin d3 has excellent sensitivity ( 100% ) and a relative good specificity ( 81% ) , it is easy to perform , and it demonstrates a good interobserver agreement .
moreover , we believe that this panel also may be a useful combination in fna cytology or cytological cell - block material , because oncocytic follicular lesions of the thyroid could represent a diagnostic challenge in the praxis .
moreover , it is important to improve the management of these patients , in order to avoid unnecessary operations .
positive results of this panel in case of histological morphology of adenoma may indicate performing additional section to exclude a capsular or vascular invasion .
it also could be of interest to evaluate this same panel in oncocytic follicular tumors of uncertain malignant potential , after a proper follow - up , to understand better the behaviour of these lesions . | ### Summary:
: aims . oncocytic ( hurthle )
follicular cell tumors ( ots ) of the thyroid are both adenomas ( oas ) and follicular carcinomas ( ocs ) .
the routine diagnosis of these tumors can be problematic even after an accurate sampling and histological examination .
beside preoperative evaluation due to the tumor 's dimension several studies have been performed to find markers able to distinguish malignant from benign follicular tumors in the thyroid , with galectin-3 being one of the most effective .
recently , some authors suggested cyclin d3 as adjunct to the diagnosis of the oncocytic lesions of the thyroid .
methods and results . in this paper
we assess the role of galectin-3 and cyclin d3 in a well - selected group of follicular oncocytic tumors ( 14 ocs and 26 oas ) .
the diameter of each lesion was also evaluated .
the combination of galectin-3 and cyclin d3 has a good specificity ( 81% ) and sensitivity ( 100% ) .
moreover , the maximum diameter ( in cm ) of ocs is greater than oas ( 4.1 versus 2.3 ) . conclusions .
we believe that the use of galectin-3 and cyclin d3 in ots of the thyroid can be a helpful panel in daily practice when histology is doubtful . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the seven transmembrane g - protein coupled receptors ( gpcrs ) comprise one of the largest gene families in the human genome and represent an estimated 25% of all drug targets .
they are activated by a variety of molecules including , but not limited to , neurotransmitters , peptides , lipids , odorants , and light , and thus participate in a wide range of physiological responses .
reverse pharmacology strategies are usually employed in the identification of ligands for newly identified gpcrs .
these ligands are in turn used for the pharmacological characterization and identification of the physiological role of these receptors .
recent studies have identified a gpcr subfamily predominantly expressed in small diameter ib4 neurons in the dorsal root ganglion ( drg ) and as such , might have a role in nociception .
members of this family have been referred to as mas - related genes ( mrgs ) or sensory neuron specific receptors ( snsrs ) . in mice ,
the mrg family is comprised of three large subfamilies ( mrga , mrgb , and mrgc ) and six single copy genes ( mrgd , mrge , mrgf / rta , mrgg , mrgh / gpr90 , and mas1 ) , that together comprise ~50 distinct sequences . the functional significance of this cellular heterogeneity among murine nociceptive sensory neurons is currently not known .
in contrast , there are only four functional mrgx / snsr genes in humans ; however , none of the human mrgx and mouse mrga , b , or c genes are strictly orthologous , making investigation of their function or testing of compounds in relevant rodent models difficult . importantly , the single copy genes mrgd , mrge , mrgf , and mrgg have clearly defined human , mouse , and rat orthologs and thus may represent experimentally tractable targets for the development of pain therapies [ 3 , 5 ] .
though many mrg family members are classified as orphan receptors , ligands for a number of these receptors have been identified , and are being used as tools to characterize their role in nociception .
these receptor / ligand pairs include human mrgx2/cortistatin , human mrgx1 ( snsr4 ) , snsr3 , and rat mrgc / bam22 ( bovine adrenal medulla peptide ) [ 4 , 7 ] , and mrga1 , mrga4 , and mrgc11/rf - amide neuropeptides [ 3 , 8 ] .
beta - alanine was identified as a ligand for mrgd , specifically evoking an intracellular ca response in cho cells expressing human , rat , or mouse mrgd .
selective mrgc agonists produced spontaneous pain behavior suggesting that an antagonist of this receptor may be of therapeutic value in treating pain .
a cell - based beta - lactamase ( bla ) reporter gene assay to identify small molecule antagonists of the human mrgx1 receptor also has been reported . though beta - alanine has been identified as a putative agonist for mrgd
, studies have not been reported describing its effects on pain . by virtue of its cross - species conservation as a single - copy gene as well as its restricted expression to small diameter nociceptive neurons
, mrgd represents an attractive target for the development of pain therapeutic agents , an endeavor that would be facilitated by the identification of potent agonists and antagonists .
a flipr based screen for mrga and mrgd agonists has been published recently , but no method for identifying mrgd antagonist has been yet reported .
the objective of the current study was to develop a mrgd assay amenable to high throughput screening ( hts ) that is capable of simultaneously identifying agonists and antagonists .
screening compound libraries in this assay format could be useful in the identification of tool compounds to probe the physiological role(s ) of mrgd .
beta - alanine , gaba , glycine , and the lopac library were obtained from sigma ( st . louis , mo ) .
a mrgx1 ( snsr4 ) cell line was purchased from multispan ( hayward , ca ) .
human mrgd ( accession number ay427820 ) was amplified from human genomic dna ( clontech , palo alto , ca ) by pcr using the forward primer xba1 5-ctag tct aga gcc gcc acc atg tac cca tac gat gtt cca gat tac gct aac cag act ttg aat agc agt-3 and the reverse primer ecor1 5-ccg gaa ttc tca agc ccc cat ctc att ggt-3. a kozak sequence and ha epitope tag were incorporated in the forward primer .
rat mrgd ( accession number af518246 ) was amplified and cloned similarly using the forward primer xba1 5-ctag tct aga gcc gcc acc atg gaa caa aaa ctt att tct gaa gaa gat ctg aac tac act cct tat agc agc c-3 and the reverse primer ecor1 5-ccg gaa ttc tca gac ccc atc att agt aca tgt-3 using rat genomic dna ( clontech , palo alto , ca ) as template .
a kozak sequence and c - myc epitope tag were incorporated in the forward primer .
the resulting pcr products were cloned into the xba i and ecor i sites of phtop vector , a proprietary derivative of the ped expression vector . for transfection , cho - dukx - a2 cells ( dhfr( ) cho cell line stably expressing the tetracycline transactivator ) were grown in m alpha media containing 1% mem nonessential amino acids solution ( neaa ) , 10% fetal bovine serum ( fbs ) , and 500 ug / ml g418 .
antibiotic selection was performed using dulbecco 's modified eagle medium supplemented with 10% fbs , 100 units / ml penicillin , 100 g / ml streptomycin , 1% neaa , and 20 nm methotrexate ( calbiochem , san diego , ca ) .
clones of human mrgd expressing cell lines were evaluated initially for mrgd transcript level by taqman analysis and normalized against the house - keeping gene gapdh ( glyceraldehyde-3-phosphate dehydrogenase ) .
cho - dukx - a2 cells stably expressing human or rat mrgd were plated in 384-well tissue - culture - treated polystyrene black clear flat - bottom assay plates ( bd biosciences , san jose , ca ) .
thirty l of 8 10 cells / ml ( 24,000 cells / well ) were plated and maintained for ~24 hrs at 37c in a humidified atmosphere containing 5% co2 .
after removal of the growth medium , cells were incubated with 30 l of ca3 dye ( molecular devices corporation , sunnyvale , ca ) containing 2.5 mm freshly prepared probenecid made according to the manufacturer 's protocol .
agonists were prepared in 1x hanks balanced salt solution ( hbss ) buffer with 20 mm hepes buffer .
changes in intracellular ca were monitored using the fluorometric imaging plate reader ( flipr ; molecular devices , sunnyvale , ca ) . for the double addition protocols ,
compounds were added by the flipr , and readings were taken for 3 min , followed by the addition of the agonist . the change in intracellular calcium [ ca ]
was monitored as an increase in relative fluorescence units ( rfus ) , and the difference between maximum and minimum rfu was used to calculate dose - response curves .
data analysis was performed using prism 4.0 ( graphpad software inc . ) . for the lopac screen ,
cells were plated in 96-well tissue - culture - treated polystyrene black clear flat - bottom assay plates ( bd biosciences , san jose , ca ) .
one hundred l of cells ( 40,000 cells / well ) were plated and maintained under the same conditions as above .
for the assay , growth medium was replaced with 90 l of ca3 dye containing 2.5 mm freshly prepared probenecid .
the flipr added 10 l of beta - alanine at 100 m final concentration . for antagonist dose - response assays
, the cells were incubated with the compounds for ~30 minutes after which beta - alanine at a final concentration of 10 m was added by the flipr .
clones of human mrgd expressing cell lines were expanded and evaluated initially for mrgd transcript level by taqman analysis .
mrgd transcripts were detected in 25 clones displaying wide - ranging expression levels ( data not shown ) .
the parental cell line was also evaluated , and mrgd transcript was absent in cho - dukx cells .
surprisingly , two clones , one with medium and the other with low transcript levels , responded best to beta - alanine , while three clones with high mrgd transcript levels showed no response .
thus , our studies indicate that mrgd rna expression inversely correlated with larger beta - alanine - induced calcium transient functional responses as assessed by flipr responses ( data not shown ) .
hence , when cell lines expressing rat mrgd were generated , they were screened for responses to beta - alanine only by flipr .
the beta - alanine ec50 values obtained for both human and rat mrgd cell lines were in the14 m range .
further characterizations of mrgd receptor - expressing cell lines were performed by evaluating responses to ligands structurally similar to beta - alanine , such as gaba and glycine .
figure 1 shows agonist dose - response curves indicating that beta - alanine is the most potent ligand followed by gaba and glycine , respectively .
the ec50 values of beta - alanine obtained for human and rat mrgd are displayed in table 1 . in light of their structural similarity to gaba
, both gabapentin and pregabalin were evaluated by flipr , but these drugs failed to induce a response in either the human or rat mrgd expressing cells .
mrgd is known to couple through both gi and gq . to further explore the utility of the cell line for a potential secondary assay measuring camp , we investigated whether the flipr assay was capable of distinguishing the extent of gi and gq coupling of mrgd .
mrgd cho - dukx cells were treated with either the gi inhibitor pertussis toxin ( ptx ) overnight or the phospholipase c ( plc ) inhibitor u-73122 for 30 or 60 minutes and then evaluated for their responses to beta - alanine .
u-73122 completely blocked the flipr response ( figure 2(a ) ) but treatment with ptx resulted in approximate 50% reduction in calcium mobilization ( figure 2(b ) ) , suggesting that the residual beta - alanine - induced response in cho - dukx cells is transduced through the coupling of mrgd to a ptx - insensitive g protein , most likely gq .
we developed an assay that could allow both agonists and antagonists to be distinguished in a single screen .
employing such an assay format should enable the identification of tool compounds that may help in elucidating the role of mrgd in pain .
the diagram in figure 3 describes the dual - addition assay format where addition of the test compound ( addition 1 ) is followed by the addition of beta - alanine ( addition 2 ) .
a flipr response immediately upon the addition of a test compound would indicate its activity as an agonist . on the other hand ,
if the compound behaves as an antagonist , not only will there be a lack of response to this test compound , it will also attenuate the effects of the subsequent addition of beta - alanine . in the event of no receptor engagement by the test compound , a normal agonist response
we validated this assay format , which was robust and consistent with a z factor greater than 0.7 . to confirm that the dual - addition flipr assay format can be extended to a hts platform , a screen of the lopac library was performed ( figures 4(a ) and 4(b ) show representative flipr traces ) .
initial evaluation of the results from the dual assay format indicated that the assay was sensitive enough to identify both agonists and antagonists . the response to test compound gaba in the lopac screening
gaba evoked a response , but as it is less potent than beta - alanine , some calcium mobilization also was induced in response to beta - alanine , albeit weaker when compared to other wells . on the other hand ,
when the first test compound was an antagonist occupying the mrgd receptor , no initial effect was detected , and there was an attenuation or complete absence of calcium mobilization following addition of beta - alanine ( c3 , g4 , g7 , and e11-chlorpromazine hydrochloride , r()-propyl - norapomorphine hydrochloride , indatraline hydrochloride and , thioridazine hydrochloride , resp .
screening the library in parallel on parental cho - dukx cells helped in identifying compounds causing nonspecific calcium mobilization ( example seen in figure 4(b ) , h5 ) . eliminating compounds that induced calcium mobilization in the parental line ensured that the agonists identified interact specifically with mrgd . to evaluate whether this assay format could be extended to other gpcr family members , we tested mrgx1 ( snsr4 ) cell lines and performed a similar dual - addition format lopac screen using its ligand bam22 to identify antagonists .
our results demonstrated that this assay format could be applied to another gpcrs with a known agonist ( data not shown ) .
in addition to gaba , three other agonists that stimulated mrgd expressed in the cho - dukx cell line but not the parental cell line were obtained from the lopac library screen ( table 2 ) .
one of these , ( ) ha 966 is a racemic mixture , and so the enantiomers were tested separately . as displayed in figure 5(a ) the ( ) ha 966 enantiomer was the most potent mrgd agonist ( ec50 5.5 m ) when compared to the racemic mixture ( ec50 11 m ) and ( + ) ha 966 enantiomer ( ec50 106 m ) .
in addition to agonists , eight mrgd antagonist compounds were also identified from the lopac screen . though compounds representing eight different structural classes were identified from the lopac library screen , only three dopaminergic compounds chlorpromazine hydrochloride ( ic50 2.73e-06 ) , thioridazine hydrochloride ( ic50 1.06e-06 ) , and r()-propylnorapomorphine hydrochloride ( ic50 1.46e-06 )
two representative compounds thioridazine and chlorpromazine are shown in figure 5(b ) . the percentage of hits confirmed after concentration response followup assay evaluation were 0.6% and 0.4% for agonists and antagonists , respectively ( table 3 ) .
an inherent difficulty in the pursuit of novel therapeutic targets is the lack of molecular and/or pharmacological tools .
several approaches are usually employed , often in parallel , to obtain insight into the functional role of novel receptors in disease states . the scientific rationale for pursuing drug discovery efforts
is often supported by the degree to which a particular target is amenable to available drug discovery technologies , its tissue localization , changes in gene expression , availability of gain or loss of function transgenic animals , and the availability of tool compounds .
receptor - ligand interactions vary , and ligands can function as agonists , antagonists , partial antagonists , or inverse agonists .
availability of any of these classes of compounds as pharmacological tools can provide insight into the physiological role of the receptor .
mrgd , a member of the mas - related gene family [ 3 , 5 ] , is specifically expressed in small diameter ib4 neurons in the dorsal root ganglion , an expression pattern that suggests that mrgd play a role in the initiation or modulation of pain signals and , as such , could be a novel target for the development of pain therapeutic agents .
elegant axonal tracer studies have shown that mrgd is expressed in a subpopulation of nonpeptidergic , nociceptive neurons that project exclusively to the skin .
these neurons innervate a specific layer of the epidermis , distinct from that innervated by peptidergic nerve fibers . to better understand the role of mrgd in pain
, our group has undertaken studies examining mrgd modulation of ion channels thought to be involved in pain signal transduction .
we have observed a novel interaction between mrgd and kcnq / m - type potassium channels that results in suppression of these channels and enhancement of the excitability of drg neurons .
these studies suggest that antagonism of mrgd could be beneficial for the treatment of pain .
genetic ablation of mouse neurons that express mrgd in adulthood caused specific deficits in the behavioral response to noxious mechanical stimuli but not to noxious heat or cold stimuli .
beta - alanine is a small amino acid structurally related to the major inhibitory neurotransmitters gamma - aminobutyric acid ( gaba ) and glycine .
our studies confirmed the previous finding that gaba , but not glycine , weakly stimulated cells expressing human and rat mrgd .
it has been reported that beta - alanine decreases glutamatergic excitation by binding to , and thus competing for , the glycine co - agonist site of the n - methyl - d - aspartate ( nmda ) receptor [ 16 , 17 ] .
it also has been shown that beta - alanine can activate glycine and gaba receptors , though with less efficacy than their native ligands [ 18 , 19 ] . as a result of the promiscuous interaction of beta - alanine with other receptors precise interpretation of the in vivo studies leading to insight regarding the role of beta - alanine in nociception is confounded .
another study was recently published in which a high - throughput calcium mobilization assay was used for the identification of agonists for mrgd and mrga .
ligands for mrga , another member of the mrg family present only in rodents , were also reported in that study and are of interest from a selectivity perspective . when reverse pharmacology approaches are employed in deorphaning
local concentrations of beta - alanine previously have been reported to be ~50 m in rat sciatic nerve and 60 m in cat brain [ 21 , 22 ] .
ec50 values for mrgd expressing cell lines have been reported to range from 8.6 m , 15 1 m , and 57.8 + 3.5 m .
after extensive characterization of ~100 clones , we were successful in obtaining cell lines showing ec50 values in the low micromolar range . having a ligand ( irrespective of its being cognate or surrogate ) and a sensitive cell line enabled us to develop a robust flipr assay with a z factor greater than 0.7 as an aid to identifying both agonists and antagonists from the same screen .
in addition to maximizing the information that can be obtained about compounds screened , great cost savings are realized by combining the two screens into one .
although the time required to screen each plate , ~10 minutes , may be viewed as a shortcoming of this assay format , we view this as a relatively minor concern when balanced against the amount of data generated and cost savings from this assay . in drug discovery ,
ideally , confirmation of hits identified from hts is done using secondary assays with different end point read outs to eliminate false positive hits .
to further characterize this cell line and explore its utility for other assays , we investigated g protein coupling by measuring mrgd responses to beta - alanine after blocking plc and gi .
our results are in agreement with previous reports that in cho cells , mrgd signaling occurs primarily through gq [ 9 , 11 , 14 ] .
however , this observation may differ across cell types , since in drg neurons , inhibition of the m current by beta - alanine activated mrgd occurs primarily through the gi pathway .
thus it is pivotal that interpretation of findings from a cell line is done with caution and g protein coupling is studied in native context . to ensure that this dual - addition assay format can be applied to other gpcrs with a known agonist
in addition to its utility in screening new targets , this dual - addition assay format also can be extended to receptors such as mglurs where both agonists and antagonists have been reported to have therapeutic value .
antagonists identified from flipr often function as inverse agonists and can be characterized further by secondary assays .
having a repertoire of agonists , antagonists and inverse agonists would be extremely useful in efforts to validate mrgd .
it was not surprising that most of the compounds obtained from the lopac screen had ec50 and ic50 values in the micromolar range .
compounds identified from this lopac screen have very limited utility primarily due to the lack of selectivity .
chlorpromazine and thioradizine are both first - generation typical antipsychotic drugs and produce catalepsy in rodents and extrapyramidal side effects in humans resulting from blockade of d2 receptors .
chlorpromazine is often referred to as dirty drug because it acts on many receptors including dopaminergic ( d1 , d2 , d3 , and d4 ) , serotonergic ( 5-ht1 and 5-ht2 ) , histaminergic h1 , alpha1/alpha2 , and muscarinic ( m1/m2 ) receptors .
chlorpromazine is a weak inhibitor of dopamine reuptake resulting in mild antidepressive and antiparkinsonian effects .
in addition , chlorpromazine inhibits calmodulin - dependent stimulation of cyclic nucleotide phosphodiesterase and nitric oxide synthase .
interestingly enough chlorpromazine has been used for analgesia in cancer patients as an adjunct to morphine in advanced cancer [ 28 , 29 ] .
however , increased risk of qtc prolongation and sudden death in patients treated with thioridazine has been reported .
the cardiac effects of thioridazine are related to the concentration - dependent blockade of the cardiac - delayed inward rectifier potassium channel ( ikr ) [ 32 , 33 ] .
thioridazine has recently attracted interest as a potential candidate for development as an antimicrobial drug . with the emergence of multidrug resistant bacteria , novel derivatives of thioridazine with reduced affinity for the ikr channel and dopamine receptors but higher potency as antimicrobial
ha-966 is an excitatory amino acid antagonist , acting principally at the nmda receptor subtype through a selective interaction with the glycine modulatory site of the receptor complex .
though the mechanism of action is not well understood , it has been suggested that nmda antagonists / opioid combinations have promise as analgesic agents for the long - term treatment of pain .
thus the antagonistic and agonist activities detected from screening lopac using our mrgd assay may be not be selective for mrgd .
it is also possible that some of these compounds from the lopac collection may be acting downstream of the receptor , inhibiting gi , gq coupling or any other signaling intermediates .
further studies are needed to assess the specific mechanism of action of these compounds .
the primary objective of this study was to develop an assay for identification of agonists and antagonists from the same screen .
the data presented here demonstrate that the dual - addition assay format can be successfully employed and adapted for hts .
it is often the case in drug discovery that extensive medicinal chemistry efforts are required to obtain highly potent drug - like compounds .
thus the compounds identified here may provide some insights for further chemistry or structure - based drug design efforts . in conclusion
, we have developed an hts assay for mrgd that will enable the identification of both agonists and antagonists from a single screen and assist in the identification of pharmacological tools that will help elucidate the role of mrgd in pain .
our results demonstrated that the dual agonist / antagonist assay format is feasible and can be extended to most gpcrs with a known agonist .
all authors were employees of wyeth research at the time the research was carried out . | ### Summary:
: mrgd , a member of the mas - related gene family , is expressed exclusively in small diameter ib4 +
neurons in the dorsal root ganglion .
this unique expression pattern , the presence of a single copy of mrgd in rodents and humans , and the identification of a putative ligand , beta - alanine , make it an experimentally attractive therapeutic target for pain with limited likelihood of side effects .
we have devised a high throughput calcium mobilization assay that enables identification of both agonists and antagonists from a single screen for mrgd .
screening of the library of pharmacologically active compounds ( lopac ) validated this assay approach , and we identified both agonists and antagonists active at micromolar concentrations in mrgd expressing but not in parental cho - dukx cell line .
further characterization was performed using a subset of these screening hits .
our results demonstrated that the dual agonist / antagonist assay format is feasible and likely can be extended to most gpcrs with known agonist . |
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: nanoparticles have drawn increasing interest from every branch of medicine for their ability to deliver drugs in the optimum dosage range , often resulting in increased therapeutic efficacy of the drug , weakened side effects , and improved patient compliance .
today , there are several examples of nontargeted nps currently used in clinical practice ( doxil and daunoxome(12 ) ) and in clinical development ( cyclosert).(13 ) early success of these lipid - based vesicular drug delivery nanoparticles has led to the investigation and development of many different compositions of polymeric nanoparticles , including polymeric micelles , dendrimers , drug conjugates , and polypeptide- and polysaccharide - based nanoparticles . among these , genexol - pm [ methoxy - peg - poly(d , l - lactide)taxol ] is the first polymeric micellar nanoparticle in phase ii clinical trials in the united states .
blood circulation residence , maximal tolerated dose ( mtd ) , and selectivity are the most important factors for achieving a high therapeutical index and corresponding clinical success .
polymeric nanoparticles are defined by their morphology and polymer composition in the core and corona ( figure 1 ) . the therapeutic load is typically conjugated to the surface of the nanoparticle , or encapsulated and protected inside the core .
the delivery systems can be designed to provide either controlled release or a triggered release of the therapeutic molecule .
surface functionalization can be utilized to increase residence time in the blood , reduce nonspecific distribution , and , in some cases , target tissues or specific cell surface antigens with a targeting ligand ( peptide , aptamer , antibody / antibody fragment , small molecule ) .
for instance , it is well established that hydrophilic polymers , most notably poly(ethylene glycol ) ( peg ) , can be grafted , conjugated , or absorbed to the surface of nanoparticles to form the corona , which provides steric stabilization and confers stealth properties such as prevention of protein absorption .
surface functionalization can address the major limiting factor for long - circulating nanoparticle systems , which is protein absorption .
proteins adsorbed on the surface of the nanoparticle promote opsonization , leading to aggregation and rapid clearance from the bloodstream .
the resultant rapid clearance is due to phagocytosis by the mononuclear phagocyte system ( mps ) in the liver and splenic filtration .
typically , the majority of opsonized particles are cleared by a receptor - mediated mechanism in fewer than a few minutes due to the high concentration of phagocytic cells in the liver and spleen , or they are excreted.(21 ) thus , over the past 20 years , numerous approaches to improving nanoparticle blood residence and accumulation in specific tissues for the treatment of disease have been developed . in this review , we will discuss the effects of physiological tissue defects ( high permeability ) and polymeric nanoparticle physicochemical properties on their biodistribution and clearance .
specifically , polymeric composition , nanoparticle size , pegylation , surface charge , and targeting functionality will be discussed .
polymeric nanoparticle platforms are characterized by their physicochemical structures , including polymerosome , solid polymeric nanoparticle , nanoshell , dendrimer , polymeric micelle , and polymerdrug conjugates .
the exact role of each of the proteins adsorbed on the surface of the nanoparticles in the clearance and biodistribution is still not clear besides their role in opsonization and enhanced hepatic uptake .
it is generally assumed that the rapid uptake of injected nanoparticles is triggered by receptor - mediated mechanisms of absorbed proteins from the blood ( opsonins ) onto their surface and complement activation . however , it is not clear if a specific type , a combination of proteins , or even the protein conformation is the most important factor for a high rate of phagocytotic uptake .
the efficacy of the peg brush in altering the biodistribution of nanoparticles has been clearly demonstrated , and in vivo studies showed a drastic increase in blood circulation time with an increase in peg surface density .
it is also clear that relatively small physicochemical differences have significant biological implications in the fate of the biodistribution of nanoparticles .
pegylated nanoparticles between 10 and 100 nm in size are able to remain in the systemic circulation for hours and extravasate or diffuse into the diseased tissues by a passive targeting mechanism .
recently , targeted nanoparticles funtionalized with ligands that have high affinity and specificity have been shown to efficiently accumulate in specific tissues and dramatically increase the therapeutic efficacy of long - circulating nanoparticle drug delivery systems .
natural and synthetic polymers are now in preclinical and clinical phases for drug delivery . more importantly , targeted and nontargeted polymeric nanoparticles are now in the preclinical and clinical phases and confirm the great promise of the past 20 years of research and lessons learned from the failure of some clinical studies to increase the therapeutic index of drugs approved for clinical use . | ### Summary:
: nanoparticle ( np ) drug delivery systems ( 5250 nm ) have the potential to improve current disease therapies because of their ability to overcome multiple biological barriers and releasing a therapeutic load in the optimal dosage range . rapid clearance of circulating nanoparticles during systemic delivery is a critical issue for these systems and has made it necessary to understand the factors affecting particle biodistribution and blood circulation half - life . in this review ,
we discuss the factors which can influence nanoparticle blood residence time and organ specific accumulation .
these factors include interactions with biological barriers and tunable nanoparticle parameters , such as composition , size , core properties , surface modifications ( pegylation and surface charge ) , and finally , targeting ligand functionalization .
all these factors have been shown to substantially affect the biodistribution and blood circulation half - life of circulating nanoparticles by reducing the level of nonspecific uptake , delaying opsonization , and increasing the extent of tissue specific accumulation . |
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: posterior fusion techniques including posterolateral fusion , posterior lumbar interbody fusion ( plif ) , transforaminal lumbar interbody fusion ( tlif ) and circumferential fusion have been performed to treat spondylolisthesis7 ) .
bone fusion and screw fixation have been associated with a high fusion rate , especially in the treatment of low grade spondylolisthesis in which the segment of the spinal column to be fused is under a more compressive load .
however , the high shear stress at the lumbar or lumbosacral junction in moderate to high grade spondylolisthesis alters this bio - mechanical advantage . moreover , forceful slip reduction was reported to have an high rate of neural injury caused by distraction of nerve roots2131415 ) .
the correction degree of sagittal translation is still controversial focus on method and degree for symptomatic spondylolisthesis .
so far , it has not been clear whether potential benefit or lack thereof is due to the translational or the angular reduction , and it is difficult to form a clear guideline for spondylolisthesis .
moreover , the use of minimally invasive mini - open plif using the percutaneous screw fixation system for moderate to severe spondylolisthesis has not been previously described .
the current study describes the surgical technique and feasibility of the mini - open plif with percutaneous screw fixation for moderate to high grade spondylolisthesis to achieve spontaneous slip reduction minimizing neural injury .
between january 2007 and december 2010 , 40 consecutive patients who underwent mini - open plif for grade ii spondylolisthesis or more were included in this study .
the inclusion criteria were : ( 1 ) no previous surgery at the level of spondylolisthesis , ( 2 ) followed up for at least 12 months , and ( 3 ) no severe osteoporosis ( the lowest t - score on dual energy x - ray absorptiometry bone mineral density > -3.0 ) .
the patients ' age ranged between 29 and 68 years ( average 59.4 ) and mean follow - up period was 24.113.5 months .
the preoperative diagnosis was 22 cases of degenerative type and 18 cases of isthmic type , comprising 32 cases with meyerding grade ii , 5 cases with meyerding grade iii and three cases with meyerding grade iv .
spondylolisthesis was present at the l3 - 4 level in three patients , at the l4 - 5 level in 24 patients and at the l5-s1 level in 13 patients .
all patients underwent mini - open plif in the prone position . following a midline skin incision , an expandable tubular retractor of appropriate length ( x - tube , medtronic sofamor danek , memphis tn .
complete removal of the scar tissue around the pars interarticularis led to the sufficient liberation of the nerve root under the slipped pedicle , achieving posterior release as well . the disc inferior to the slipped vertebrae was thoroughly resected , lateral to both pedicles , in which course , the disc space was gradually distracted and released with sequential disc shavers , removing of the anterior annulus as much as possible that was even in conjunction with anterior longitudinal ligament ( all ) to accomplish exhaustive anterior release , followed by insertion of cages bilaterally . during the maneuver , due to circumferential release
, it could be found that the slipped vertebrae tended to obtain partial spontaneous reduction .
secondly , percutaneous pedicle screws with a vertical axis and detachable extender ( apollon system , solco medical , south korea ) were inserted without additional skin incision .
after dissection of the subdermal plane , the percutaneous screws were inserted following retraction of the skin .
furthermore , with the compressing the screws into each other to create a lumbar lordosis , additional reduction could be achieved without any application of compulsive force .
imaging and clinical findings including involved level , slip percentage , lumbar lordotic angle , focal segmental angle , clinical outcomes , and complications were analyzed .
clinical outcomes were measured using a self assessment 10-point visual analog scale ( vas ) and low back outcome score ( lbos ) normalized to 75 ( table 1 ) .
the slippage was measured from standing lateral radiographs and calculated as the quotient of sagittal displacement expressed in percent .
lumbar lordotic angle was defined by cobb 's method , using the intersection of lines at the level of the superior plateau of l1 and the inferior plateau of l5 .
focal segmental angle was defined as the focal angle of superior line of spondylolisthetic level and inferior line of adjacent lower level .
all patients underwent mini - open plif in the prone position . following a midline skin incision , an expandable tubular retractor of appropriate length ( x - tube , medtronic sofamor danek , memphis tn . ,
complete removal of the scar tissue around the pars interarticularis led to the sufficient liberation of the nerve root under the slipped pedicle , achieving posterior release as well .
the disc inferior to the slipped vertebrae was thoroughly resected , lateral to both pedicles , in which course , the disc space was gradually distracted and released with sequential disc shavers , removing of the anterior annulus as much as possible that was even in conjunction with anterior longitudinal ligament ( all ) to accomplish exhaustive anterior release , followed by insertion of cages bilaterally . during the maneuver , due to circumferential release , it could be found that the slipped vertebrae tended to obtain partial spontaneous reduction .
secondly , percutaneous pedicle screws with a vertical axis and detachable extender ( apollon system , solco medical , south korea ) were inserted without additional skin incision .
after dissection of the subdermal plane , the percutaneous screws were inserted following retraction of the skin .
furthermore , with the compressing the screws into each other to create a lumbar lordosis , additional reduction could be achieved without any application of compulsive force .
imaging and clinical findings including involved level , slip percentage , lumbar lordotic angle , focal segmental angle , clinical outcomes , and complications were analyzed .
clinical outcomes were measured using a self assessment 10-point visual analog scale ( vas ) and low back outcome score ( lbos ) normalized to 75 ( table 1 ) .
the slippage was measured from standing lateral radiographs and calculated as the quotient of sagittal displacement expressed in percent .
lumbar lordotic angle was defined by cobb 's method , using the intersection of lines at the level of the superior plateau of l1 and the inferior plateau of l5 .
focal segmental angle was defined as the focal angle of superior line of spondylolisthetic level and inferior line of adjacent lower level .
all patients were followed for at least 12 months and the mean follow - up period was 24.1 months . at a minimum of 12 months follow - up , all cases appeared to have solid fusions as judged by the presence of a trabecular bony bridge or less than 5 on dynamic flexion and extension views .
lumbar lordosis , measured from the upper endplate of l1 to the inferior endplate of l5 , was 43.013.8 before surgery . in spite of no statistical significance ,
mean lordosis was changed to 48.210.3 at last follow - up ( p>0.05 ) ( fig .
2 ) . degree of focal segmental angle , measured from the upper endplate of slipped vertebra to lower endplate of adjacent vertebra , was 10.18.5 before surgery . at the latest follow - up ,
the focal segmental angle was 15.96.0 , which improved significantly ( p<0.01 ) ( fig .
the mean lbos prior to surgery was 32.5 , which improved to 53.1 at the last follow - up ( p=0.037 ) . from a preoperative average of 7.5 ,
the vas score was decreased significantly to 3.0 at 7 days postoperatively and 2.9 at the final follow - up ( p=0.015 ) .
there was no case to be converted into conventional open surgery due to technical difficulty .
complications included one case of medial penetration of pedicle border , which needed screw re - insertion and two cases with a superficial wound infection . however , there was no pseudoarthrosis .
all patients had a solid bony fusion at the last follow - up , without any dislocation compared to the immediate postoperative radiographs .
two patients with grade iii spondylolisthesis showed a signs of a transient root lesion after surgery ( 1 case of transient and mild motor weakness and 1 case of radiating pain and sensory change ) , which resolved completely .
however , there were no permanent neurological sequelae as a result of miniopen plif ( fig . 4 and 5 ) .
preoperative slippage averaged 38.012.6% . at the latest follow - up , mean slippage improved significantly to 9.37.8% ( p<0.001 ) ( fig .
lumbar lordosis , measured from the upper endplate of l1 to the inferior endplate of l5 , was 43.013.8 before surgery . in spite of no statistical significance ,
mean lordosis was changed to 48.210.3 at last follow - up ( p>0.05 ) ( fig .
degree of focal segmental angle , measured from the upper endplate of slipped vertebra to lower endplate of adjacent vertebra , was 10.18.5 before surgery . at the latest follow - up ,
the focal segmental angle was 15.96.0 , which improved significantly ( p<0.01 ) ( fig .
the mean lbos prior to surgery was 32.5 , which improved to 53.1 at the last follow - up ( p=0.037 ) . from a preoperative average of 7.5 ,
the vas score was decreased significantly to 3.0 at 7 days postoperatively and 2.9 at the final follow - up ( p=0.015 ) .
there was no case to be converted into conventional open surgery due to technical difficulty .
complications included one case of medial penetration of pedicle border , which needed screw re - insertion and two cases with a superficial wound infection . however , there was no pseudoarthrosis .
all patients had a solid bony fusion at the last follow - up , without any dislocation compared to the immediate postoperative radiographs .
two patients with grade iii spondylolisthesis showed a signs of a transient root lesion after surgery ( 1 case of transient and mild motor weakness and 1 case of radiating pain and sensory change ) , which resolved completely .
however , there were no permanent neurological sequelae as a result of miniopen plif ( fig . 4 and 5 ) .
spondylolisthesis is a relatively common disease with an incidence approximately 5% of the population requiring fusion surgery4 ) .
low - grade spondylolisthesis may be managed by conservative treatment in some cases , but in moderate to high grade spondylolisthesis , nonoperative methods are not able to prevent the progressive back and radiating pain , increasing slip and deformity or cauda equina symptoms .
decompression was introduced as the treatment for spondylolisthesis that induces radiating pain by gill in 1955 , and subsequently various surgical techniques have been performed1 ) .
symptomatic spondylolisthesis usually require surgical intervention , the goals of which include the stabilization of the motion segment , decompression of neural elements , reconstitution of disc space height , and restoration of sagittal plane translational and rotational alignment . among them ,
plif is a widely performed procedure and it has been associated with the improvement of the fusion rate while restoring disc height and maintaining vertebral alignment for spondylolisthesis .
moreover , recently , mini - open plif using percutaneous screw fixation system can provide many potential benefits compared to conventional plif5 ) .
for the treatment of symptomatic spondylolisthesis , however , the role of compulsory translational reduction and instrumentation is controversial . some proponents state
that the reduction itself will improve the rate of fusion and improve spinopelvic balance3 ) .
the theoretical advantages of slip reduction include improved spine biomechanics , better nerve root decompression , and chance to obtain fusion because it provides an increased surface area of the fusion bed and the fusion is no longer under the influence of tension and anterior shear forces .
another advantage of slip reduction is the correction of the sagittal deformity to improve posture .
re - aligning the spine and achieving sagittal balance are important in the long run by preventing premature adjacent level disc degeneration12 ) . on the contrary , a forceful and mandatory instrumented slip reduction can certainly lead to reduction even by 100% , which will increase the risk of permanent complications .
the major disadvantage of complete slip reduction is the increased risk of neural injury caused by excessive distraction of nerve roots11 ) .
the various hypothetical cause of neurologic injury include direct pressure on the nerve root during reduction , impingement of the nerve roots on the iliolumbar ligaments , extradural tension on the nerve roots , and disc material extruded into the canal68 ) .
moreover , for the treatment of high - grade spondylolisthesis , the risk of neural injury caused by forceful reduction and pseudarthrosis is much higher910 ) . to overcome these disadvantages ,
pan et al.12 ) reported that circumferential release , including scar resection for posterior release complete disc removal and distraction with rupture of annulus conjunct with anterior longitudinal ligament for anterior release in the treatment of low - grade isthmic spondylolisthesis .
significant slip reduction for the group was achieved and the fusion rate approached 100% with no definite neurological complications .
they insisted that spondylolisthesis has a certain trend toward spontaneous reduction intraoperatively , including the reduction of translational and rotational deformity , which can provide good outcomes .
resection of the scar around the pars interarticularis would lead to liberation of the nerve roots , which could help to achieve posterior release .
the disc was totally resected with removing the anterior annulus as much as possible even in conjunction with all , and the disc space was gradually distracted with sequential disc shavers to fully restore the disc space height , accomplishing anterior release .
second , with the insertion of cages to maintain the height , the following influence of percutaneous pedicle fixation on the spinal alignment by compressive force , additional reduction could be achieved without any application of powerful posterior translational force . as a result ,
no forceful tension acts on the pedicle screw system , obviously decreasing the anterior shear forces .
all the surgical procedures in this study were performed by a single surgeon to eliminate the variable effects of different surgeon on surgical outcome . however , larger - scale , multicenter studies involving more surgeons are necessary to validate our results .
mini - open plif following circumferential release contributes to achieving spontaneous slip reduction without neurologic deterioration .
this minimal invasive technique is safe and efficient even in the moderate to high grade spondylolisthesis . | ### Summary:
: objectivethe purpose of this study was to evaluate the surgical technique and outcome of mini - open posterior lumbar interbody fusion ( plif ) under circumferential releasing technique.methodsfourty patients who underwent mini - open plif using the percutaneous screw fixation system for meyerding grade ii spondylolisthesis or more were retrospectively studied .
after complete circumferential release , the slipped vertebrae would tend to obtain spontaneous reduction , and with compressive force by percutaneous screw fixation , additional reduction could be achieved .
the radiological measurements including slippage reduction , disc height , restoration of lumbar lordotic angle and focal segmental angle were analyzed .
the clinical outcome was assessed using the visual analog scale ( vas ) and low back outcome score ( lbos ) , and procedure related complications were also analyzed.resultsslippage percentage was improved from 38.012.6% to 9.37.8% and lumbar lordotic angle was changed from 43.013.8 to 48.210.3. focal segmental angle improved from 10.18.5 to 15.96.0. the mean lbos and mean pain score were also improved significantly .
complications included one case of medial penetration of pedicle border and two cases of transient radiculopathy .
however , there were no signs of neurological aggravation or fusion failure during the follow - up period.conclusionmini-open plif using the percutaneous screw fixation following complete circumferential release can be safe and effective treatment for even moderate to severe grade spondylolisthesis . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: endoscopic ultrasound - guided fine needle aspiration ( eus - fna ) is a safe , accurate and inexpensive technique , and the interpretation is reliable when performed by trained cytopathologists .
however , the diagnostic sensitivity is superior only when the specimen is assessed onsite for diagnostic adequacy and most institutions do not have skilled individuals to render onsite assessment .
a fine needle biopsy ( fnb ) specimen contains core tissue with better preservation of cellular architecture than an fna specimen and therefore has greater diagnostic accuracy and provides more tissue for ancillary studies .
it may be specifically requested by pathologists to establish a definitive diagnosis in challenging cases when fna is inconclusive or for identification of molecular markers that are specific for neoplasms such as pancreatic neuroendocrine tumors , malignant melanoma , and metastatic lung or breast cancer . to meet these expectations , a 19 gauge ( g ) trucut needle biopsy ( eus - tnb ; cook endoscopy , winston - salem , nc , usa ) was developed to procure larger amounts of tissue with conserved architecture that would enable histological analysis .
the overall diagnostic accuracy of eus - tnb for evaluating suspicious lesions at various sites in the body is reported to be 75% to 84% and 61% to 67.5% for pancreatic masses.1,2 while the eus - tnb technique has some advantages over fna , the rigidity induced by the 19 g caliber needle and the mechanical friction of the firing mechanism produced by the torqued echoendoscope , limits its use for evaluating pancreatic head and duodenal lesions . to overcome this limitation ,
a new 19 g fnb device was recently developed with procore ( cook endoscopy ) reverse bevel technology to enable the acquisition of core specimens . in a recent study from europe , histologic samples were obtained successfully with this procore needle in a majority of patients with a diagnostic accuracy of more than 90%.3 however , some technical difficulties were still encountered when performing transduodenal passes .
the same fnb device is also available in a 22 and 25 g platform to facilitate easy transduodenal sampling . in a recent randomized trial that compared the 22 g procore and the standard 22 g fna needle for sampling of pancreatic mass lesions
, there was no significant difference in the rates of diagnostic sufficiency ( 100% vs. 89.3% ) , technical failure ( 0% vs. 3.6% ) , or complications ( 3.6% for both ) between the standard fna and procore needles , respectively.4 patients in whom diagnosis was established in passes 1 , 2 , and 3 were 64.3% versus 67.9% , 10.7% versus 17.9% , and 25% versus 3.6% , respectively , for the fna and procore cohorts .
also , there was no significant difference in procurement of histologic core ( 100% vs. 83.3% ) or the presence of diagnostic histologic specimens ( 66.7% vs. 80% ) between the fna and procore cohorts , respectively . in a prospective study of 50 patients with solid pancreatic masses
, eus - guided sampling was performed using the 25 g procore needle.5 malignancy was diagnosed in 38 patients on the first pass , with a cumulative sensitivity of 83% , 91% , and 96% on passes 1 , 2 , and 3 , respectively . although visible core was reported in 46 patients ( 92% ) , histologic core
histologic analysis showed malignancy in 29 patients on the first pass , with a cumulative sensitivity of 63% and 87% on pass 1 and passes 1 to 4 , respectively .
a summary of findings from key abstracts presented at digestive diseases week 2013 that compared the fna and procore needle is shown in table 1.6 - 13 as evident from the table , heterogeneity in clinical trials makes interpretation of results difficult . well designed randomized trials comparing the different gauge procore and standard fna needles in pancreatic masses and other solid organ lesions is required to establish conclusive results .
the role of the standard 19 g fna needle for yielding histological samples was assessed prospectively in a recent study.14 of the 120 patients who underwent eus - guided tissue acquisition , the procedure was technically successful in 119 patients ( 98.9% ) and adequate histological sample was obtained in 116 ( 97.5% ) .
a major limitation of the study was that patients with pancreatic head or uncinate masses were excluded .
as the standard 19 g needle is too stiff to navigate the transduodenal route , a flexible 19 g needle made of nitinol has been recently introduced . in a pilot study of 50 patients , which included several patients that underwent eus - fna via the transduodenal route ,
tissue acquisition was successful and adequate for cytologic assessment in 100% of patients and satisfactory histologic specimens were procured in 94.7% of patients.15 needle dysfunction or procedural complications were not encountered in this study . while manufacturer guidelines must be followed when using specially designed biopsy needles , when using a 19 g needle , to minimize bloodiness , one must not use suction or a stylet and repeated jabbing at the same area should be avoided .
it is usually not necessary to perform more than three fnb passes in a lesion as repeated biopsies are more likely to yield blood clots .
while the eus - tnb technique has some advantages over fna , the rigidity induced by the 19 g caliber needle and the mechanical friction of the firing mechanism produced by the torqued echoendoscope , limits its use for evaluating pancreatic head and duodenal lesions . to overcome this limitation , a new 19 g fnb device was recently developed with procore ( cook endoscopy ) reverse bevel technology to enable the acquisition of core specimens . in a recent study from europe , histologic samples were obtained successfully with this procore needle in a majority of patients with a diagnostic accuracy of more than 90%.3 however , some technical difficulties were still encountered when performing transduodenal passes .
the same fnb device is also available in a 22 and 25 g platform to facilitate easy transduodenal sampling . in a recent randomized trial that compared the 22 g procore and the standard 22 g fna needle for sampling of pancreatic mass lesions
, there was no significant difference in the rates of diagnostic sufficiency ( 100% vs. 89.3% ) , technical failure ( 0% vs. 3.6% ) , or complications ( 3.6% for both ) between the standard fna and procore needles , respectively.4 patients in whom diagnosis was established in passes 1 , 2 , and 3 were 64.3% versus 67.9% , 10.7% versus 17.9% , and 25% versus 3.6% , respectively , for the fna and procore cohorts .
also , there was no significant difference in procurement of histologic core ( 100% vs. 83.3% ) or the presence of diagnostic histologic specimens ( 66.7% vs. 80% ) between the fna and procore cohorts , respectively . in a prospective study of 50 patients with solid pancreatic masses ,
eus - guided sampling was performed using the 25 g procore needle.5 malignancy was diagnosed in 38 patients on the first pass , with a cumulative sensitivity of 83% , 91% , and 96% on passes 1 , 2 , and 3 , respectively . although visible core was reported in 46 patients ( 92% ) , histologic core was seen in only 16 patients ( 32% ) .
histologic analysis showed malignancy in 29 patients on the first pass , with a cumulative sensitivity of 63% and 87% on pass 1 and passes 1 to 4 , respectively .
a summary of findings from key abstracts presented at digestive diseases week 2013 that compared the fna and procore needle is shown in table 1.6 - 13 as evident from the table , heterogeneity in clinical trials makes interpretation of results difficult .
well designed randomized trials comparing the different gauge procore and standard fna needles in pancreatic masses and other solid organ lesions is required to establish conclusive results .
the role of the standard 19 g fna needle for yielding histological samples was assessed prospectively in a recent study.14 of the 120 patients who underwent eus - guided tissue acquisition , the procedure was technically successful in 119 patients ( 98.9% ) and adequate histological sample was obtained in 116 ( 97.5% ) .
a major limitation of the study was that patients with pancreatic head or uncinate masses were excluded . as the standard 19 g needle is too stiff to navigate the transduodenal route ,
a flexible 19 g needle made of nitinol has been recently introduced . in a pilot study of 50 patients , which included several patients that underwent eus - fna via the transduodenal route ,
tissue acquisition was successful and adequate for cytologic assessment in 100% of patients and satisfactory histologic specimens were procured in 94.7% of patients.15 needle dysfunction or procedural complications were not encountered in this study . while manufacturer guidelines must be followed when using specially designed biopsy needles , when using a 19 g needle , to minimize bloodiness , one must not use suction or a stylet and repeated jabbing at the same area should be avoided .
it is usually not necessary to perform more than three fnb passes in a lesion as repeated biopsies are more likely to yield blood clots .
the currently available procore and flexible 19 g needles are a significant advancement in acquiring core tissue during eus - guided procedures . although there are no randomized trials comparing the performance of the procore and flexible 19 g needle , the decision to choose either needle should be based on operator preference and costs .
however , eus - guided tissue acquisition is a multistep procedure and must be patient - centered . providing the correct type of sample based on clinical need , sampling the lesion using the best evidence - based techniques ,
procuring adequate tissue for ancillary studies and closely collaborating with cytopathologists and oncologists are all important in order to have good technical and clinical outcomes . | ### Summary:
: endoscopic ultrasound - guided fine needle aspiration ( eus - fna ) is routinely performed for establishing tissue diagnosis in patients with gastrointestinal tumors .
the concept of delivering chemotherapy based on molecular markers and the ability to establish a reliable diagnosis in lieu of an onsite cytopathologist has fuelled the recent trend in procuring core tissue by means of eus - guided fine needle biopsy . to overcome the technical limitations induced by the rigidity of the trucut biopsy needle
, a new procore needle with reverse bevel technology has been developed .
recent data suggests that the newly developed flexible 19 gauge needle can also procure core tissue and has easy maneuverability when navigating the transduodenal route .
irrespective of the needles being used , the best clinical outcomes can be attained only by practicing evidence - based techniques , procuring adequate quantity of sample for ancillary studies , and processing the specimens appropriately . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: osteoporosis can lead to devastating health consequences and poses a substantial health care burden currently affecting an estimated 44 million americans ( nih ) . in women ,
estrogen deficiency is primarily responsible for the rapid postmenopausal loss of bone mass and resulting structural fragility ( type i osteoporosis ) while a slower bone loss ( type ii or senile osteoporosis ) affects both men and women late in life .
bone structure begins to decline early ; peak bone mass is achieved in early adulthood and progressively declines in both high turnover , cancellous tissue and in the surrounding hard cortical shell .
the compartments of bone affected by osteoporosis can include both the dense tissue that forms an outer structural shell ( cortical bone ) and the spongy tissue ( cancellous bone ) within the marrow cavity ; the microarchitecture of cancellous bone is profoundly affected in osteoporosis and renders sites that are rich in cancellous tissue , such as the spine and proximal femur , prone to fracture .
an age - related decline in cancellous tissue structure occurs in rodents over a matter of months , rather than years , as in humans .
c57bl/6j mice provide a well - established animal model with relatively rapid postpubertal loss of cancellous tissue [ 3 , 4 ] , characteristic of that which precedes the development of senile , type ii osteoporosis in humans .
bone turnover is regulated by a balance between the activities of bone - forming osteoblasts and bone - resorbing osteoclasts .
osteoblasts progressively differentiate from progenitors and mesenchymal stem cells whereas osteoclasts are haematopoietic derivatives of the monocyte / macrophage lineage .
stem cells , progenitors , and precursors of both lineages reside within the bone marrow .
bone marrow cells cultured ex vivo retain behavioral characteristics of in vivo function ; thus bone marrow - derived cells cultured under conditions tailored either to stimulate osteoblast differentiation ( osteoblastogenesis ) or osteoclast differentiation ( osteoclastogenesis ) are useful tools to dissect cellular and molecular bases of physiological challenges such as skeletal aging and exposure to radiation [ 58 ] .
ionizing radiation generates reactive oxygen / nitrogen species ( ros / rns ) both by the ionization of target molecules and by perturbations to the cellular redox state , also implicated in the development of osteoporosis [ 912 ] .
the production of ros / rns causes oxidative damage to dna , lipids , and protein influencing key cell functions , including proliferation , differentiation , and apoptosis .
low linear energy transfer ( let ) ionizing radiation ( e.g. , gamma rays , x - rays ) at high cumulative doses ( > 200 cgy ) can damage vascular supply ( osteoradionecrosis ) , leading to loss of cortical and cancellous tissue and leading to skeletal fragility , while adverse effects of lower doses ( 100200 cgy ) appear to be confined to cancellous tissue in animal models [ 12 , 1416 ] . much less
here we hypothesized that low - to - moderate doses of ionizing radiation accelerate postpubertal and progressive loss of microarchitectural integrity over time .
ionizing radiation at 100 cgy ( but not at 1 cgy or 10 cgy ) caused structural changes in cancellous tissue within one month that occurred over 4 months in controls , with no further decrements following 1 month .
the capability of marrow - derived cell populations to differentiate into osteoblasts or osteoclasts was unaffected .
a total of 96 c57bl/6j 10-week old male mice ( the jackson laboratory , bar harbor , me ) were housed 2/cage for up to 4 months . this age and duration of the experiment
were selected on the basis of results reported by others , showing that this encompasses a period of microarchitectural changes that are associated with osteopenia ( reduced bone density ) over time [ 3 , 4 ] .
mice were provided food ( labdiet 5001 , purina mills , gray summit , mo ) and water ad libitum .
after three days of cage acclimation , unanesthetized mice ( 4 per exposure ) were irradiated ( ir ; jl shepherd mark i , cs gamma ray source , san gabriel , ca ) with 1 , 10 , or 100 cgy at 0.96 , 0.96 , or 88 cgy / min ( 10% ) , respectively , or were sham - irradiated ( 0 cgy - controls ) .
, mice were placed in container ( 10 cm radius ) , centered 18 cm from the source , and rotated at 6 rpm . radiation dose and uniformity
was calibrated in air by jl shepherd & associates using an x - ray monitor ( no .
2025 , mdh industries , monrovia , ca ) with a 0.18 cm probe ( national institutes of standards and technology traceable ) .
tissues were harvested on the day of ir ( basal ) or 1 or 4 months later ( n = 8/group ) , with cell culture being performed at the latter two endpoints . as an indicator of health ,
total body mass was measured ( e0d120 scale , ohaus corporation , parsippany , nj ) at least once per week until tissue harvest . the institutional animal care and use committee of nasa ames research center approved all procedures .
microcomputed tomography ( vivact 40 , scanco medical ag , brttisellen , switzerland ) allows direct quantification of the microarchitecture of mineralized tissue ( 10.5 m voxel size ) within the proximal tibia metaphysis .
standard indices were generated within the excised right tibia in a region 0.2 to 1.2 mm distal to the proximal growth plate via semiautonomous contouring of cross - sectional slices , as reported in detail previously .
the relative amount of bone to total volume ( bv / tv , bone volume fraction ) quantifies the amount of bone present .
the thickness of the bony struts , the thickness ( or spacing ) of the marrow voids , and trabecular number characterize trabecular morphologys on average .
the structure model index measures the ratio of rod - like ( =3 ) to plate - like ( = 0 ) trabeculae within the tissue .
the fabric tensor quantifies the anisotropic orientation of the structure , relating to mechanical properties [ 21 , 22 ] , with three eigenvalues describing the axial lengths of the anisotropy ellipsoid and the degree of anisotropy equaling the ratio of the maximum to minimum eigenvalues .
marrow cells from the hindlimbs ( femora and tibiae ) were grown as previously described . in brief , cells were flushed from the bone marrow and plated in -mem supplemented with 15% fetal calf serum with osteoblastogenic supplements ( ascorbate 50 g / ml , sigma - aldrich , st .
louis , mo ) and -glycerophosphate ( 10 mm , sigma - aldrich , st .
, cells were plated overnight in macrophage colony stimulating factor ( mcsf , 30 ng / ml , r&d systems inc , minneapolis , mn ) and nonadherent cells collected , replated , and grown in -mem supplemented with 15% fetal calf serum with mcsf ( 30 ng / ml ) and soluble receptor activator of nuclear factor b ligand ( srankl , 60 ng / ml , peprotech , rocky hill , nj ) .
osteoclastogenesis was assessed 4 - 5 days after euthanasia by counting the number of multinucleated , tartrate resistant acid phosphatase - positive ( trap+ , sigma aldrich ) cells in a defined area by microscopy ( between 18 and 45 mm ) to count a minimum of 200 cells .
osteoblastogenesis was assessed one month after irradiation by quantifying the surface area covered by alizarin red - stained , mineralized nodules .
statistical analyses were performed using jmp 8 ( sas institute inc , cary , nc ) . to address aging , three groups of sham controls
least squares linear regressions were performed with time as regressor and the null hypothesis of the slope being zero to assess changes over time .
the coefficient of determination ( r ) and the probability ( p ) of the slope being zero are reported , with p = 0.05 the threshold for rejecting the null hypothesis . for each time point after - irradiation , comparisons were made between the sham - irradiated and irradiated mice .
analyses proceeded using one - factor anova with the tukey - kramer honestly significant difference post hoc test , and p = 0.05 considered the threshold for significance .
sham - irradiated mice gained 10% body mass from 1014 wk of age ( figure 1 .
inset , r = 0.96 , p < 0.05 for slope ) and 30% body mass from 1027 wk of age ( r = 0.99 , p < 0.05 for slope ) . compared to the age - matched controls , irradiation at any dose did not affect the mass accrual ( figure 1 ) .
these data are consistent with previous studies that monitored radiation and aging effects [ 3 , 4 ] and show that normal accrual of body mass , as a broad measure of health over time at this age , was unimpeded by exposure to gamma irradiation with these doses .
the cancellous bone volume fraction remained constant ( figure 2(a ) ) , bone density increased , and most microarchitectural parameters declined as the mice aged over the 4-month period of this study .
trabecular number ( 21% , r = 0.79 , p < 0.05 ) and connectivity density ( 49% , r = 0.75 , p < 0.05 ) declined over 4 months ( figures 2(d ) and 2(e ) ) .
each eigenvalue of the anisotropy tensor increased ( all p < 0.05 ) within 4 months .
the degree of anisotropy remained constant at 2.0 indicating a persistent longitudinal orientation of the structure ( figure 2(h ) ) .
in contrast to these indicators of increasing structural fragility with aging , trabecular thickness ( + 22% , r = 0.35 , p < 0.05 ) as in , and tissue density ( + 9% , r = 0.59 , p
< 0.05 ) rose over 4 months ( figures 2(b ) and 2(c ) ) .
we observed age - related changes in the cancellous microarchitecture of the tibia within the 4-month timeframe . in our study ,
declines in trabecular number and connectivity density ensued , while relative bone volume , rod - like morphology and degree of anisotropy remained constant .
concurrently , the cancellous tissue consolidated gains into thicker and denser , though fewer , trabecular struts .
trabeculae were spaced farther apart with age ( data not shown ) and may increase the propensity for strut buckling [ 23 , 24 ] .
these changes are consistent with normal aging of male c57bl/6 mice , including declines of trabecular number and connectivity density , which appeared to start sooner and fall more rapidly with aging than the bone volume fraction [ 3 , 4 ] . in sum , these data suggest that age - related alterations of microarchitecture within the mouse tibia may precede overt declines in cancellous bone volume .
radiation doses of 1 cgy or 10 cgy had no discernible effect on skeletal microarchitecture at either 1 or 4 months after - ir . in 100 cgy - ir mice , trabecular number and connectivity density declined ( 20% and 36% , resp . ;
p < 0.05 ) and trabecular spacing and the maximum eigenvalues of the fabric tensor increased ( + 28% and + 21% , resp . ;
p < 0.05 ) at one month after - ir compared to age - matched controls ( figure 2 ) .
there were no additional decrements in microarchitecture compared to age - matched controls between 1 and 4 months after - ir ( figure 2 ) .
these results indicate that 100 cgy irradiation caused rapid removal of trabecular , which resembled the normal microarchitectural changes expected to occur during 4 months of aging .
irradiation with 100 cgy caused reductions in trabecular number and connectivity density and increases in the major axis of the anisotropy ellipsoid within 1 month changes that take 4 months to appear in sham - irradiated controls . in previous studies that used older mice ( 16 weeks of age ) ,
100 cgy caused bone loss in the tibia via reduced trabecular thickness , but not trabecular number , with the onset of osteopenia appearing 10 days after - irradiation .
the 16-week - old mice are past peak cancellous bone volume in the tibia , whereas the 10-week - old mice in this study have not yet begun to decline .
microarchitectural changes following irradiation observed in this study resembled the effects of a larger dose in older , male mice ( 16 weeks , 200 cgy ) within the lumbar spine ( a denser , plate - like cancellous tissue ) and in the tibia ( unpublished results ) , where gamma irradiation at 200 cgy caused vertebral and tibial bone loss via trabecular number and connectivity density decrements appearing within 3 days and persisting at least until 30 days after - irradiation .
furthermore , in young female mice ( 9 weeks ) , osteopenia and trabecular number and connectivity density decrements persist in the tibia at 120 days after - irradiation . taken together ,
the data indicate that bone resorption is a time - dependent process contingent on initial bone volume and morphology ( i.e. , structure model index ) and that skeletal outcome is a function of age . in this study ,
microarchitectural differences between irradiated and age - matched controls were not evident 4 months after exposure to 100 cgy radiation .
this result contrasts to the persistence of osteopenia in the tibia after low let irradiation at higher doses ( 200 cgy x - ray or gamma rays ) or with particulate irradiation at doses of 100 cgy ( proton ) and 200 cgy ( fe ) which present at 120 days after - irradiation in female mice ( 9 weeks ) .
these findings highlight the importance of age at the time of irradiation ; gender also may influence skeletal radioresponses and further study is needed in this area . to assess differentiation of osteoblast lineage progenitors and precursors in the mesenchymal stem cell lineage
, adherent cells from bone marrow were cultured in osteogenic medium up to one month and then stained for mineralized nodules ( figure 3 ) .
irradiation did not affect the area covered by mineralized nodules ( figure 3(a ) ) .
these data suggest the osteoblast progeny of irradiated cells are not affected by a single , acute dose of low let , ionizing radiation .
bone marrow cells were cultured after tissue harvest in osteoclastogenic media and then osteoclast number counted . in sham - irradiated controls , between 1 and 4 months after - ir , the density of osteoclasts remained constant ( figure 3(b ) ) and indicates the number of precursors did not vary with age .
furthermore , irradiation at any dose did not affect the differentiation potential of osteoclasts compared to controls . per animal ,
the ratio of nodule area fraction to osteoclast density was calculated as a measure of the balance between formation and resorption potential ; this was unchanged in controls between 1 and 4 months and unchanged after irradiation at any dose ( data not shown ) .
thus , neither osteoblastogenesis nor osteoclastogenesis by bone marrow cells was affected by gamma irradiation , consistent with our previous findings .
these results suggest the ability of marrow - derived progenitors to contribute to skeletal remodeling is preserved , despite exposure to ionizing radiation . gamma rays or x - rays ( 200 cgy )
can cause a rapid ( within 3 days ) increase in the numbers of osteoclasts lining the surfaces of trabeculae [ 15 , 16 ] , and a decrement in actively mineralizing surfaces , an index of the activity of mature , active osteoblasts .
taken together , our results suggest that mature cells of the osteoblast and osteoclast lineage , rather than progenitors , are responsible for the near - term microarchitectural changes triggered by gamma radiation .
a limitation of this study design is that bones were analyzed at only two time points after exposure to radiation .
additional timepoints would be useful to further characterize the influence of radiation on age - related changes in skeletal health .
a moderate dose ( 100 cgy ) of gamma radiation accelerated changes in the trabecular microarchitecture of postpubertal , growing ( 10 wk old ) male c57bl/6 mice at a rate comparable to later skeletal aging in controls , whereas no effects were observed at even lower doses ( 1 or 10 cgy ) .
together with the finding that bv / tv did not differ over this time , these results suggest age - related microarchitectural changes precede bone loss .
bone marrow - derived osteoblast progenitors and osteoclast precursors did not appear to be affected by the low - to - moderate doses of low let gamma radiation used here , suggesting stem and progenitor cells that reside in the marrow will retain the ability to contribute to skeletal remodeling during subsequent aging following the low - to - moderate doses employed .
in contrast , exposure to high doses of gamma radiation or to high let irradiation such as fe can inflict acute and persistent damage to osteoprogenitors ( , unpublished observations ) . in conclusion , ionizing gamma irradiation at 100 cgy ( but not at 1 cgy or 10 cgy ) appeared to accelerate structural changes in the murine skeleton , expected also to occur during progressive , postpubertal aging in humans prior to the onset of type ii osteoporosis . | ### Summary:
: osteoporosis can profoundly affect the aged as a consequence of progressive bone loss ; high - dose ionizing radiation can cause similar changes , although less is known about lower doses ( 100 cgy ) .
we hypothesized that exposure to relatively low doses of gamma radiation accelerates structural changes characteristic of skeletal aging .
mice ( c57bl/6j-10 wk old , male ) were irradiated ( total body ; 0-sham , 1 , 10 or 100 cgy 137cs ) and tissues harvested on the day of irradiation , 1 or 4 months later . microcomputed tomography
was used to quantify microarchitecture of high turnover , cancellous bone .
irradiation at 100 cgy caused transient microarchitectural changes over one month that were only evident at longer times in controls ( 4 months ) .
ex vivo bone cell differentiation from the marrow was unaffected by gamma radiation . in conclusion ,
acute ionizing gamma irradiation at 100 cgy ( but not at 1 cgy or 10 cgy ) exacerbated microarchitectural changes normally found during progressive , postpubertal aging prior to the onset of age - related osteoporosis . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the incidence of lower urinary tract symptoms ( luts ) gradually increases with age , greatly affecting quality of life ( qol ) .
treatment options for luts range from behavioral modification , such as bladder training , to medical treatment .
antimuscarinic agents and 1-blockers are the most frequently prescribed drug options , but in japan , complex formulations of japanese traditional herbal medicines have been widely used and empirically evaluated in patients with luts and cold sensitivity .
recent animal studies have revealed that hachimi - jio - gan ( hjg ; b wi d hung wn ) and gosha - jinki - gan ( gjg ; j shng shn q wn ) increased bladder capacity and decreased frequency of distension - induced bladder contractions via the spinal kappa - opioid receptor .
previous clinical studies have demonstrated the efficacy of hjg and gjg , frequently in conjunction with antimuscarinic agents or 1-blockers , for treating luts .
although luts has various symptoms , we have focused on cold sensitivity , a key indication in japanese traditional herbal medicine . in the present study , we attempted to determine the efficacy and safety of hjg and gjg as an add - on therapy for patients with luts and cold sensitivity , unresponsive to 1-blockers or antimuscarinic drugs by using the international prostate symptom score ( ipss ) , ipss - quality of life ( ipss - qol ) , benign prostatic hyperplasia impact index ( bii ) , uroflowmetry ( ufm ) , frequency volume chart ( fvc ) , and urinary 8-hydroxy-2-deoxyguanosine ( 8-ohdg ) .
before commencing the study , we obtained approval from our institution 's ethical review board and obtained written informed consent from all participants after thoroughly explaining the efficacy and possible adverse reactions of hjg ( b wi d hung wn ) and gjg ( j shng shn q wn ) mixture .
hjg ( tj-7 ; tsumura co. , tokyo , japan ) is the extract product which included 4.0 g of the compound extracts of 8 herbal medicines : rehmanniae radix ( d hung ) ( 6.0 g ) , corni fructus ( shn zh y ) ( 3.0 g ) , dioscoreae rhizoma ( shn yo ) ( 3.0 g ) , hoelen ( f ling ) ( 3.0 g ) , alismatis rhizoma ( z xi ) ( 3.0 g ) , moutan cortex ( m dn p ) ( 2.5 g ) , cinnamoni cortex ( gu p ) ( 1.0 g ) and heat - proscessed aconiti radix ( f z ) ( 0.5 g ) . on the other hand , gjg ( tj-107 ; tsumura co. , tokyo , japan ) includes 4.5 g of the compound extracts of 10 herbal medicines : rehmanniae radix ( 5.0 g ) , achyranthis radix ( ni x ) ( 3.0 g ) , corni fructus ( 3.0 g ) , dioscoreae rhizoma ( 3.0 g ) , hoelen ( 3.0 g ) , plantaginis semen ( ch qin z ) ( 3.0 g ) , alismatis rhizoma ( 3.0 g ) , moutan cortex ( 3.0 g ) , cinnamoni cortex ( 1.0 g ) and heat - proscessed aconiti radix ( 1.0 g ) .
they are standaedized spray - dried water extracts , which include magnesium stearate , lactose and fructose fatty acid esters as diluents .
patients who visited our hospital with luts for consultation between november 2012 and may 2014 were considered for enrollment .
the inclusion criteria were as follows : age 60 years or older ; ipss total score of 8 or more points despite treatment with 1-blockers or antimuscarinic drugs for at least 4 weeks ; ipss - qol score of 3 or more points ; subjective complaints such as cold hands and/or legs even in a warm environment .
patients with any complications possibly affect the voiding function , such as neurogenic bladder , urethral stricture , and active urinary tract infection , were excluded .
the study was designed as an open , non - randomized , two - armed study comparing two japanese traditional herbal medicines for treating luts .
all patients received 7.5 g / day hjg or gjg mixture for 12 weeks as add - on therapy to 1-blockers or antimuscarinic drugs .
blood cell count , standard chemistry panel , and urinalysis were assessed routinely at the initial examination .
ipss , ipss - qol , bii , 3-day fvc and ufm were examined before and after administration .
we evaluated urinary 8-ohdg levels as a marker of oxidative stress using an icr-001 device ( the selling agency of icr-001 device is selista inc , tokyo ) according to the manufacturer 's recommendations .
data were analyzed using spss software , version 12.0 ( ibm , chicago , il ) . to evaluate the treatment effect between before and after mediation , wilcoxon 's signed - rank test was used to table 1 , table 4 . the other hand , student 's t - test was used to table 2 , table 3 .
thirty patients ( 23 men and 7 women , aged 6880 years , mean 74.7 6.2 ) received hjg mixture and 30 ( 24 men and 6 women , aged 6780 years , mean 75.5 5.1 ) received gjg mixture .
total ipss score , bii , post - void residual urine ( pvr ) , maximal urinary flow rate ( qmax ) , and urinary 8-ohdg did not significantly differ between the hjg and gjg groups . however , ipss storage subscore , qol and nocturnal voids were significantly greater in the gjg group .
significantly improved subjective outcomes were ipss total and subscore , qol , and bii , and significantly improved objective outcomes were fewer nocturnal voids and lower urinary 8-ohdg .
other objective parameters such as qmax and pvr did not improve . in the gjg group ( table 3 ) , significantly improved subjective outcomes were ipss total and subscore , qol , and bii .
although the number of nocturnal voids decreased significantly , other objective parameters , namely , qmax , pvr , and urinary 8-ohdg did not improve .
no statistical significant differences were found between the hjg and gjg groups in terms of total ipss score , ipss subscore , qol , bii , pvr , qmax , or number of nocturnal voids . however , there was a significantly larger decrease in urinary 8-ohdg in the hjg group ( 5.7 5.4 ) than in the gjg group ( 0.9 5.1 ) ( p = 0.017 ) .
on the other hand , the adverse reactions of gjg were observed in 2 men and 1 woman ( 10% ) .
the symptoms were gastric discomfort in 2 patients and nausea in one , and all such cases were of mild sevirity ( grade 1 ) and were followed up closely without therapy .
hjg ( b wi d hung wn ) and its modified prescription gjg ( j shng shn q wn ) are prescribed to patients with edema in the lower extremities and luts with cold sensitivity .
the way by which hjg and gjg treat luts have remained unclear , but resent basic research has gradually clarified these mechanisms.5 , 6 , 7 , 8 , 9 gotoh et al . reported that the effects on luts are associated with inhibition of the micturation reflex and reduction of bladder sensation via spinal kappa - opioid receptors . among the ingredients contained in these medicines , aconiti rhizhoma ( f z ) from aconitum carmichaelii
in addition to the effect of aconiti rhizhoma , kupelian et al . hypothesized that other ingredients , such as alismatis rhizoma ( z xi ) from alisma orientale and poria ( f ling ) from poria cocos , could be effective for decreasing nocturnal urine production and thereby regulating the distribution of fluid in the body . in the present study , we selected patients with luts unresponsive to both 1-blockers and antimuscarinic drugs .
we had a tendency of prescribing gjg for patients with more edematous extremities , so that it is suggested that ipss storage subscore , qol and nocturnal voids were significantly greater in the gjg group .
some people have experience of cool hands and/or legs ( s zh bng lng ) even in a warm environment , without clinically evident cardiovascular disease .
these sensations are an indication of cold sensitivity , an important concept in oriental medicine . by comparing the cold stress rat model to control rats , imamura et al . reported that cold stress - induced detrusor overactivity
is mediated through a resiniferatoxin - sensitive c - fiber sensory nerve pathway . in a separate study , imamura et al . showed that hjg - treated rats tended to have higher skin temperature during low - temperature exposure and that their cold stress - induced detrusor overactivity associated with increased micturition frequency and decreased micturition volume was inhibited . in this study
, we did n't evaluate the relevance of luts and cold sensitivity by continuous skin surface temperature measurement .
however , our findings in of improved subjective and objective outcomes for luts are support these previous findings in the cold rat model .
oxidative stress is reported to result in pathophysiological conditions of the urinary bladder via damage to the urothelium and sensitization of bladder afferent signaling .
previous studies have shown that oxidative stress mediates capsaicin - sensitive c - fibers to induce bladder hyperactivity .
therefore , the elimination of oxidative stress might ameliorate pathophysiological conditions in the urinary bladder and be a possible therapy for luts unresponsive to 1-blockers or antimuscarinic drugs.16 , 17 in the present study , we found anti - oxidative effects of hjg but not gjg .
the gjg formula is a modification of hjg formed by addition of achyranthis radix ( ni x ) from achyranthes fauriei and plantaginis semen ( ch qin z ) from plantago asiatica , yet there was no anti - oxidative effect as indicated by production of 8-ohdg .
the reason for this is not clear from the present study , but recent studies have revealed that chinese medicinal herbs ( cmhs ; zhng co yo)indicate anti - oxidative effects to a living body by biological response modifier ( brm ) . adding two herbal agents ( achyranthis radix and plantaginis semen ) to hjg , brm of hjg might be influenced to the anti - oxidative effects .
although anticholinergic agents are presently most commonly used in the treatment of overactive bladder , the anti - oxidant properties of hjg could have a therapeutic role in the treatment of bladder hyperactivity .
the major drawbacks of this study are small number of patients , lack of a placebo - controlled group , and lack urodynamic study data
. the possibility of a placebo effect may be high in luts , which has a strong placebo component .
therefore , it remains unclear whether hjg and gjg may be potential therapeutic alternatives in elderly patients with luts and cold sensitivity unresponsive to 1-blockers or antimuscarinic drugs .
the hjg ( b wi d hung wn ) and gjg ( j shng shn q wn ) japanese herbal formulations might have the potential to provide additional therapeutic effects in treating cold stress
| ### Summary:
: we evaluated the efficacy and tolerability of hachimi - jio - gan ( hjg ; b wi d hung wn ) and gosha - jinki - gan ( gjg ; j shng shn q wn ) , two traditional japanese medicines , in 60 patients with lower urinary tract symptoms ( luts ) having cold sensitivity unresponsive to 1-blockers or antimuscarinic drugs .
all patients received a mixture of hjg or gjg for 12 weeks in addition to 1-blockers or antimuscarinic drugs as add - on therapy .
international prostate symptom score , international prostate symptom score quality of life , benign prostatic hyperplasia impact index , and the number of nocturnal voids were statistically much improved . however , there was no change in maximal urinary flow rate and post - void residual urine .
urinary 8-hydroxy-2-deoxyguanosine was statistically greatly improved from baseline after treatment in the hjg group compared to the gjg group .
adverse reactions were observed in 8.3% of patients , but all reactions were mild .
both hjg and gjg mixtures can serve as safe and effective potential therapeutic alternatives in patients with luts and cold sensitivity unresponsive to 1-blockers or antimuscarinic drugs .
additionally , hjg mixture was found to have anti - oxidative activity , and therefore further long - term clinical investigations are needed to examine its anti - aging effects in addition to its effect on urinary symptoms . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: thrombosis is considered an uncommon complication in patients with acquired immunodeficiency syndrome ( aids ) .
recent literature describes an incidence ranging from 0.26% to 7.6% ; higher incidence is seen in patients with active opportunistic infections ( ois ) or malignancy and patients with aids .
mechanisms such as presence of antiphospholipid antibody ( apla)-anticardiolipin antibody ( acla ) , decreased activities of natural anticoagulants ( especially protein s ) , increased platelet activation , and use of protease inhibitor have been postulated .
we report a 9-year - old female child with aids who presented with multiple cerebral infarcts along with protein s and c deficiency .
a 9-year - old girl was referred to our pediatric human immunodeficiency virus ( hiv ) clinic with left - sided hemiparesis for 8 months and loss of vision and bladder and bowel control for the past 3 months .
she had sudden onset weakness of left side of the body before 8 months which improved partially and then had a recurrence of weakness 3 months back along with generalized tonic - clonic seizures , blindness , loss of bladder , and bowel control .
she was admitted to a hospital at that time , and computed tomography ( ct ) of the brain was done which was suggestive of right middle cerebral artery infarct and cerebrospinal fluid examination was normal .
she was started on antituberculous therapy ( att ) by the attending physician . however , she had no clinical improvement .
there was no fever , contact with tuberculosis ( tb ) , or other illnesses in the past .
mother had died 2 years ago and father was also detected to be hiv - positive .
she had a younger brother and sister and both were also found to be hiv infected .
her milestones were normal till age and she had received only bacillus calmette gurin vaccine . on examination ,
she was wasted ( weight = 12 kg , < 5 centile ; height = 102 cm , < 5 centile ) and had generalized lymphadenopathy , bilateral visual impairment with preserved pupillary reflex , left - sided hemiparesis with bilateral hypertonia and brisk reflexes , and dystonia .
investigations reconfirmed positive hiv elisa , hemoglobin was 7.1 g% , white cell count was 6300/cumm ( 48% polymorphs , 52% lymphocytes ) , platelet count was 370,000/cumm .
magnetic resonance imaging of the brain showed severe cerebral atrophy with bilateral subdural fluid accumulation with bilateral internal cerebral artery occlusion with diffuse narrowing of the vertebrobasilar arteries and non - filling of the middle and anterior cerebral artery mainstem with extensive infarction within the cerebral cortex bilaterally with acute lesion in the occipital lobe suggestive of multiple infarcts in various stages of development [ figure 1 ] .
thrombotic workup in the form of aclas , aplas , urine for homocystinuria , sickling test , antinuclear antibody , double - stranded dna was negative .
cholesterol , prothrombin time ( 12.1 s ) , partial thromboplastin time ( 20.3 s ) , antithrombin iii ( 165 ) , factor v leiden antibody , and echocardiography were normal .
protein c ( 52% [ normal = 70140% ] ) and protein s ( 66% [ normal = 70140% ] ) were low .
she was started on three - drug antiretroviral therapy ( art ) in the form of zidovudine , lamivudine , and efavirenz along with aspirin and warfarin .
she had an improvement in her vision over a period of 3 weeks and her international normalized ratio was maintained at 1.5 times the normal level .
ct of the brain showed right subdural hematoma [ figure 2 ] which was evacuated by surgical intervention , and aspirin and warfarin were withheld .
she has been continued on her art , but there is no marked clinical improvement .
acquired functional protein s deficiency has been seen in over 55% of hiv - infected children .
it has been found that aids , cd4 count < 200/mm , presence of ois , aids - related neoplasms , or autoimmune disorders such as autoimmune hemolytic anemia may predispose to a thrombotic disease . in our patient too , her cd4 count was less than even 100 cells / cumm and she already had aids . with acute ois , it has been found that protein c and protein s levels may fall significantly which then increase once the oi is controlled . in our patient
the child had been started on att by a doctor , but there was no evidence of tb clinically or on investigation in this child .
thus , the protein c and s levels seem to be low due to advanced hiv disease . protein s deficiency has been found in over 50% patients with hiv and 8% patients without an oi . however , combined protein c and protein s deficiency have rarely been encountered . in our patient ,
although the presence of apla - aclas had also been implicated for hypercoagulability in hiv - infected patients as earlier reported by us , these antibodies were negative in our patient ruling out antiphospholipid syndrome .
however , in our patient following anticoagulants and aspirin , she developed a subdural hematoma which was removed .
thus , one would have to be very judicious in the use of anticoagulants and antiplatelet agents in these patients .
decrease in natural anticoagulants such as protein c and/or s may be a predisposing factor .
| ### Summary:
: thrombotic episodes have occurred in patients with human immunodeficiency virus ( hiv ) infection , and various abnormalities leading to hypercoagulable state have been reported . however , multiple cerebral infarctions in an hiv - infected child along with protein s and protein c deficiency are rare .
we report such a case in an antiretroviral therapy - naive hiv - infected female child . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: to identify additional pathways involved in centrosome separation , we designed an in vitro evolution approach . by treating cells with increasing doses of the eg5 inhibitor s - trityl - l - cysteine ( stlc ) , we generated cells that grow in the complete absence of eg5-activity .
careful characterization of these eg5-independent cells ( eics ) showed that they undergo a relative normal cell division , with functional bipolar spindles and , strikingly , these eics performed normal centrosome separation in prophase .
we found that kinesin-12/kif15 ( also known as hklp2 ) promotes bipolar spindle assembly in these cells .
kif15 was previously identified to act together with eg5 in bipolar spindle assembly . under normal conditions
however , overexpression of kif15 can fully compensate for the loss of eg5-activity in prometaphase .
this function of kif15 depends on its interaction with tpx2 , a ran - regulated microtubule - binding protein .
but kif15 can not take over all the functions of eg5 since tpx2 is nuclear during interphase whereas kif15 is present in the cytoplasm .
this physical separation of kif15 and tpx2 before neb makes it impossible for kif15 to drive centrosome separation in prophase .
indeed , depletion of kif15 in normal cells and in eics did not result in reduced centrosome separation in prophase .
using the eics , we instead identified a novel pathway that drives prophase centrosome separation involving the minus - end - directed motor dynein .
depletion of selected pools of dynein showed that nuclear envelope ( ne)-associated dynein is responsible for prophase centrosome separation in the eics .
interestingly , we found that ne - dynein is also involved in centrosome separation in normal cells , although in most cell types this function of ne - dynein is masked by the dominant activity of eg5 .
? results from various studies indicate that eg5 generates an outward force specifically on the centrosome pairs , most likely by crosslinking overlapping mts from both centrosomes in an antiparallel orientation and subsequently sliding them apart .
however , it was shown over a decade ago that centrosomes move largely independently of each other during prophase , indicating that the mechanism of prophase centrosome movement is , at least partially , intrinsic to each centrosome .
this suggests that the forces that drive prophase centrosome movement not only derive from the eg5-driven antiparallel mt - sliding , but that additional forces that act on individual centrosomes also contribute to centrosome separation , independent of the mt - overlap . in order to study centrosome movements that occur independent of the mt - overlap , we imaged centrosome movements in cells that contain only a single centrosome and are thus unlikely to form an antiparallel mt - overlap .
these movements are driven by ne - dynein since depletion of dynein itself or the dynein recruitment factor bicd2 , significantly reduced the observed movements .
an important remaining question is : how can a motor that is homogeneously distributed over the ne provide an asymmetric pulling force on a single centrosome , which is required for the centrosome to undergo net movement ?
one attractive hypothesis is that the mt aster growing from the centrosome is non - symmetric .
centrosomal mts will have different lengths and longer mts can interact with more dynein molecules on the ne . in this way , differences in the length of centrosomal mts will be translated into differential forces acting on the centrosome from different sides .
this would result in a net imbalance of forces acting on the centrosome where the longest mts direct centrosome movement ( fig .
however , stochastic fluctuations in length are unbiased and will likely not generate stable asymmetry in the total pool of centrosomal mts .
possibly , the oval geometry of the nucleus could lead to differences in mt - stability along the surface of the nucleus .
alternatively , the pulling forces generated by dynein molecules could increase mt - stability and can thereby promote asymmetry of the aster toward the direction of movement .
it was shown previously that polymerizing mts show a dramatic increase in catastrophe frequency when they collide against barriers . in case of two centrosomes that need to separate , mts nucleated from one centrosome might collide into the dense mt network emanating from the other centrosome , resulting in more frequent catastrophies when growing toward the opposing centrosome .
this would result in an asymmetric centrosomal mt - network with longer mts growing away from the other centrosome . as a consequence
, this asymmetric distribution might result in a net outward force leading to separation of the two centrosomes ( fig .
a similar mechanism , involving mt length - dependent force generation , has been proposed during aster centering in early frog and fish embryos .
future work should be directed to understand how ne - dynein functions and how it can generate polarized pulling forces on prophase mt - asters that promote centrosome separation .
when forces act on a single centrosome , movements are likely directed toward the side of the longer mts , due to the presence of higher number of dynein binding sites .
( b ) when two centrosomes are present , mts emanating from one centrosome may physically collide with mts from the other centrosome , resulting in mt catastrophe specifically between the two centrosomes .
this results in an asymmetric distribution of dynein pulling forces and shifts the balance of centrosome movement in a net outward direction .
previous studies showed that cells with normal eg5-activity do not require prophase centrosome separation to build a functional bipolar spindle .
this raises the question whether prophase centrosomes separation is generally important for cells ? in eics , inhibition of prophase centrosome separation does prevent bipolar spindle assembly .
in addition , normal cells with reduced eg5-activity are more prone to form a monopolar spindle when prophase centrosome separation is inhibited .
together , these results suggest that prophase centrosome separation acts redundant with mechanisms in prometaphase that push centrosomes apart .
a recent study showed that cells , separating their centrosomes during prophase show about a 3-fold fewer errors in chromosome segregation and spend shorter time in mitosis compared with their counterparts that fail to separate their centrosomes before neb .
together , this data indicates that prophase centrosome separation improves the robustness and timely assembly of the bipolar spindle during mitosis , and improves the fidelity of chromosome separation .
despite the large amount of studies conducted in the last decade to understand centrosome separation , the contribution of different pathways and exact molecular mechanisms are still not fully understood . due to its essential function in centrosome separation and bipolar spindle assembly , eg5 has received a lot of attention .
multiple labs showed , using elegant in vitro studies , that eg5 likely drives centrosome separation by sliding antiparallel mts apart .
in contrast to eg5 , the exact mechanism by which ne - dynein drives prophase centrosome separation remains to be determined .
detailed analysis of the mt network in prophase is required in order to see if symmetry - breaking events of mt growth indeed occur .
in addition to that , tracking the movement of centrosomal pairs in an eg5-independent fashion and in vitro reconstitution experiments would also give more insights into dynein - dependent centrosome separation in prophase . | ### Summary:
: eg5 ( kinesin-5 ) is a highly conserved microtubule motor protein , essential for centrosome separation and bipolar spindle assembly in human cells . using an in vitro
evolution approach , we generated human cancer cells that can grow in the complete absence of eg5 activity .
characterization of these eg5-independent cells ( eics ) led to the identification of a novel pathway for prophase centrosome separation , which depends on nuclear envelope ( ne)-associated dynein . here
, we discuss our recent findings and elaborate on the mechanism by which dynein drives centrosome separation . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: a 44-year - old man had bilateral proptosis with gradual onset for 15 months . at that time , a diagnosis of graves orbitopathy was established elsewhere , and moderate improvement was obtained with corticosteroid treatment .
3 weeks prior to our examination , he developed worsening proptosis and bilateral painless swelling of the face and temporal area as well as eyelid edema and chemosis [ fig . 1 ] and was admitted to the hospital .
( a ) initial presentation ( b ) 6 months after corticosteroids treatment his best corrected visual acuity was 20/40 in the right eye ( od ) and 20/25 in the left eye ( os ) .
there was a right relative afferent pupillary reflex and mild extraocular movements restriction in all gaze directions
general physical examination revealed bilateral palpable but not well - defined , non - fluctuating , firm and immobile mass , involving an area from chin to the zygomatic and pre - auricular region .
biochemical profile , serum urea and creatinine levels and thyroid function tests were normal or negative .
orbital computed tomography scan revealed enlargement of all extraocular muscles with sparing of tendons , diffuse apical orbital mass in both orbits , temporalis muscle and eyelid edema [ fig . 2 ] . magnetic resonance imaging ( mri ) on t1-weighted images revealed a diffuse thickened subcutaneous hypointense mass , bilateral enlargement of the temporalis muscles and enlargement of all extraocular muscles .
the mass was slightly hyperintense on t2-weighted images and showed intense and slightly heterogenous enhancement on post gadolinium injection t1-weighted images [ fig . 3 ] .
( a ) axial ct scan ( b ) coronal ct scan ( a ) mr t1 weighted with contrast ( b ) mr t2 weighted biopsy specimens from the orbital fat , the inferior rectus and the temporal subcutaneous region were performed as well of the cervical limphonodes .
the histopathologic finding of the periorbital tissue were replacement of subcutaneous adipose tissue by fibrous stroma containing increased blood vessels , lined by plumped endothelial cells , dense inflammatory infiltrate rich in lymphocytes , eosinophils , plasma cells and several reactive lymphoid follicles [ fig . 4 ] .
the lymph node showed follicular hyperplasia with eosinophil precipitate in the germinal center ; in the interfollicular zone , there was an increase of eosinophils among the lymphoid cells and the diagnosis of kd was established [ fig .
a reactive lymphoid follicle in the periorbital subcutaneous adipose tissue high - power view of the inflammatory infiltrate rich in eosinophils treatment starting with 80 mg of oral prednisone per day followed by slow tapering led to a significant improvement after 6 months [ fig . 1 ] .
after 2 years of treatment when the corticosteroid was discontinued , the patient had mild recurrences of eyelid edema and had to be maintained with low dose oral corticosteroid treatment .
his final visual acuity presented slight improvement to 20/30 in od and no change of the 20/25 in os .
kimura 's disease is chronic inflammatory disorder of unknown etiology , which presents with tumor - like swellings , mainly in the head and neck region .
although infectious etiologies have been postulated , kd is now believed to be related to an autoimmune or a delayed hypersensitivity reaction .
an aberrant allergic response is further supported by the association with asthma , allergic rhinitis and conjunctivitis , atopic dermatitis , and peripheral hypereosinophilia as well as raised serum ige levels .
it was first described in the chinese literature as eosinophilic hyperplastic lymphogranuloma , but became widely known as kd after kimura et al . reported similar cases .
it is usually a localized process without systemic manifestations , but associated conditions have been described including allergic diseases and nephrotic syndrome .
it appears to be situated usually in the superior orbit and is largely asymptomatic apart from its mass effect .
the condition may mimic specific and non - specific inflammations of the orbit , neoplasias and graves orbitopathy as exemplified in our case .
histopathological findings in the orbit or elsewhere in the body are proliferation of lymphoid follicles and germinal centers , showing interfollicular infiltration by eosinophils . computed tomography scan findings are non - specific and consist of homogenously enhancing lymphadenopathy and enlarged salivary glands , with an ill - defined subcutaneous mass extending from the salivary gland .
kd usually presents hypointensity on t1-weighted images , but may have different patterns of signal intensity on t2-weighted , depending on the variability of fibrosis and vascularity .
the degree of post - contrast enhancement can also be variable and is not related to the degree of hyperintensity on t2-weighted images .
the treatment modalities for kd include surgical excision , oral corticosteroid , cytotoxic drugs and radiation therapy .
in the present case , an oral corticosteroid greatly reduced the swelling of the eyelids and rectus muscles with mild recurrence after discontinuity of corticosteroid hormone . in conclusion , this paper documents the occurrence of severe bilateral involvement of all recti muscles caused by kd and serves to emphasize the need to include kd in the differential diagnosis of diffuse extraocular muscle enlargement .
our case also supports the use of systemic steroids as a valuable treatment modality of such condition . | ### Summary:
: kimura 's disease ( kd ) is a rare chronic inflammatory disease of unclear etiology , characterized by subcutaneous nodules , mainly in the head and neck region , frequently associated with regional lymphadenopathy .
orbital involvement is infrequent and when it occurs , usually affects the eyelid or the lacrimal gland .
we report a case of a 44-year - old man that presented with bilateral slowly progressive proptosis that was initially misdiagnosed as graves ophthalmopathy .
15 months of worsening proptosis and the development of facial and temporal swelling led to further investigation . computed tomography and magnetic resonance imaging showed enlargement of all recti muscles and diffuse orbital infiltration .
an orbital biopsy was performed and was consistent with the diagnosis of kd .
long term oral corticosteroid showed marked improvement of proptosis and facial swelling .
this case serves to emphasize that kd should be included in the differential diagnosis of inflammatory diseases of the orbit , even when characterized by predominant involvement of the extraocular muscles . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the success of the recently developed atraumatic restorative treatment ( art ) procedure
relies on the performance of glass ionomer cements ( gics ) .
the art technique consists of
excavating infected dentine caries with hand instruments , followed by sealing the
cavities and adjacent fissures with the gic . in this procedure , the
conventional hand - mixed gics are known as the most commonly recommended dental material
because of their fluoride and aluminum releasing patterns and also low ph
characteristics during the adhesion reaction . in a previous study ,
it was reported that using manual instruments and restoring the cavities with gics might
have a possibility to control the caries disease . however
, when conventional hand - mixed and fluoride containing gics are used for sealing
cavities , it may be questionable whether caries inhibition process would occur under the
restorations.cavities treated by art may have residual infected dentine and if a gic is
unable to arrest the carious process , the restoration could fail .
additionally , caries
removal using the hand excavation technique is not always as effective as rotary burs in
terms of eliminating bacteria .
thus , when gic restorations are placed ,
residual bacteria may remain viable for up to 2 years , and the resulting infected dentin
may cause restoration failure . to address this problem , several studies have been undertaken to enhance the
antibacterial properties of the gics .
these ideas may constitute new suggestions for
improving antibacterial properties of gics without jeopardizing their basic
physicomechanical characteristics in the current literature .
chlorhexidine ( chx ) is a widely used
antibacterial agent , and has been used to enhance the antibacterial properties of
gics .
in addition , other cationic disinfectants such as
cetrimide ( ct ) , cetylpyridinium chloride ( cpc ) and benzalkonium chloride ( bc ) have been
incorporated into the gics . in a previous study , botelho1,3
( 2005,2003)showed that the addition of these agents to the conventional gic
fuji ix in various concentrations had significant antimicrobial effects .
however ,
incorporation of antibacterial agents may cause basic mechanical changes in the physical
properties of gics . in this
regard , botelho(2004)also showed
that the addition of ct , cpc , bc and chx in concentrations of 1 to 4% to fuji ix reduced
the compressive strength at 7 days .
such a reduction in strength is likely to affect the
clinical performance of the cement .
botelho4
( 2005 ) went on to use chx , bc and ct at 1 to 5% final concentrations
with dentin conditioner and found that in most cases , the bond strength of fuji ix to
dentin was unaffected .
the one exception was bc at 5% , where there was a slight decrease
in bond strength .
surface hardness is an important factor in controlling wear resistance and thus can be
used as an indication of likely long - term durability of materials .
recently , it has been shown that
microhardness is a valid measure of the surface properties of gics . in vickers microhardness [ vickers hardness number ( vhn ) ]
measurements , the hardness number increases as surface hardness increases .
this study was undertaken to obtain information on the effects of incorporating ct , cpc
and chx into the powder of fuji ix and bc into the liquid of fuji ix .
microhardness was
determined as an indication of the effect of these additives on the mechanical
properties and hence the likely durability of the cements .
these various additives were
used at concentrations of 1% and 2% , and the values were compared to those of a control
group of additive - free fuji ix samples .
all experiments were conducted using the conventional hand - mixed gic fuji ix ( gc , tokyo ,
japan ) . ct ( serva , heidelberg , germany ) , cpc ( amresco , ohio , usa ) and chx ( serva ) were
added to the powder , while bc ( serva ) was added to the liquid at 1% and 2% final
concentrations by mass .
this produced a total of 9 groups , 8 experimental and 1 control
( figure 1 ) .
samples with dimensions of 5 mm diameter and
2 mm depth were prepared by placing freshly mixed cement pastes in metal moulds and
allowing them to cure for the appropriate length of time .
eight gic samples ( 5 mm in diameter and 2 mm deep ) were prepared for each group .
the
gic samples were prepared according to the manufacturers ' directions and a polyester
strip was used to cover the cement for 7 min until the initial reaction was
completed .
cements were covered with varnish and after the completion of the setting reaction ,
samples were placed into the plastic moulds containing distilled water and stored at
37c for 90 days .
vhn measurements were made at 1 , 7 , 15 , 30 , 60 , and 90 days with
the standard microhardness tester ( hmv-700 , shimadzu corp . ,
tokyo , japan ) on the top
of the surface of each specimen and recorded .
vickers diamond indentations were
performed under a load of 300 g and 15 s. each sample was subjected to three
indentations located 200 m far from each other , and the mean vhn value was recorded .
the diagonal length of the impressions were measured and the hardness ( h ) was
calculated according to the standard formula h=1.854p / d . to determine significant differences between the groups ,
a one - way anova was
performed followed by dunnett t test and tamhane t2 tests . to obtain the significant
differences during the study period , repeated measurements anova was used for
multiple comparisons of the individual groups at 95% confidence interval using spss
for windows 15.0 ( spss , inc . ,
eight gic samples ( 5 mm in diameter and 2 mm deep ) were prepared for each group .
the
gic samples were prepared according to the manufacturers ' directions and a polyester
strip was used to cover the cement for 7 min until the initial reaction was
completed .
cements were covered with varnish and after the completion of the setting reaction ,
samples were placed into the plastic moulds containing distilled water and stored at
37c for 90 days .
vhn measurements were made at 1 , 7 , 15 , 30 , 60 , and 90 days with
the standard microhardness tester ( hmv-700 , shimadzu corp . ,
tokyo , japan ) on the top
of the surface of each specimen and recorded .
vickers diamond indentations were
performed under a load of 300 g and 15 s. each sample was subjected to three
indentations located 200 m far from each other , and the mean vhn value was recorded .
the diagonal length of the impressions were measured and the hardness ( h ) was
calculated according to the standard formula h=1.854p / d .
to determine significant differences between the groups , a one - way anova was
performed followed by dunnett t test and tamhane t2 tests . to obtain
the significant
differences during the study period , repeated measurements anova was used for
multiple comparisons of the individual groups at 95% confidence interval using spss
for windows 15.0 ( spss , inc . , chicago , il usa ) .
table 1 presents the mean values ( and standard
deviations ) of surface microhardness at 1 , 7 , 15 , 30 , 60 , and 90 days for all groups .
vickers microhardness values in the control group were generally higher than those of
the groups containing additives at most time intervals and for most of the additives .
while bc and chx groups demonstrated the closest , ct and cpc groups showed the most
distant values to the fuji ix control .
mean vickers hardness number ( vhn ) values of all groupsstandard deviations ( sd )
during the study period after storage in distilled water * in each column ( each storage time period ) , values with different superscript
uppercase letters indicate significant differences between control and
experimental groups ( p<0.05 ) . *
* in each column ( each storage time period ) ,
values with different superscript lowercase letters indicate significant
differences ( p<0.05 ) among experimental groups ( p>0.05 ) . * * * in each row
( individual group ) different superscript numbers indicate significant
differences between all study periods ( p<0.05 ) .
analysis of kinematic ,
kinetic and electromyographic patterns during root canal preparation with
rotary and manual instruments one - way anova and the dunnett t test showed that the differences were significant
between the control and experimental groups in all cases ( p<0.05 for all ) . in
addition , one - way anova and the tamhane t2 test revealed no significant differences
between the 1% bc - 1% chx groups at 7 and 15 days ( p>0.05 ) and 1% ct- 1%
cpc
( p>0.05 ) groups at all time periods ( table
1 ) . additionally , repeated measurements of anova was indicated significant differences
between all study periods for individual groups ( p<0.05 ) .
after 7 days , vhns
decreased to different extents in all study groups ( p<0.05 ) , except for the controls
( p<0.05 ) . at 60 and 90 days
, the vhns were decreased most markedly in the 2% ct and
2% cpc groups ( table 1 ) .
as it is known , dentin carious lesions possess a wide microflora , it is clear that a
mixture of antimicrobial agents that can be effective against all the microorganisms
needed .
additionally , cationic
disinfectants may destroy the bacteria cell wall and kill the bacteria
directly .
thus , since the progression of caries process under the
gics in art procedures are considered to be a problem this can be solved with the dental
materials that inhibit bacterial growth . for these purposes ,
cationic disinfectants have been incorporated into gics to enhance
their antibacterial properties . though these have been
shown to be effective as antibacterial additives , it is important not to jeopardize the
basic physical properties of the gic .
the critical point is that gic - antibacterial combinations should have optimum surface
properties to resist occlusal loads.however , when antibacterial materials
are incorporated to the gics , alterations have been reported regarding their physical
properties and it is generally accepted in the literature that the physical properties
of gics are deteriorated with the addition of foreign antibacterial particles .
investigators have highly recommended that providing acceptable
modifications in powder or liquid ratios , in terms of composing suitable antibacterial
concentrations , would aid the gic - antibacterial structure to have comparable physical
properties to those of the additive - free ones by constituting efficient antibacterial
features .
thus , gic - antibacterial combinations
should be prepared in an acceptable way which could adequately reduce the bacteria
without compromising the longevity of the restoration .
considering these factors , the
antibacterial materials and their concentrations tested in this study were previously
found sufficient in terms of reducing microorganisms .
moreover , incorporating
ct , cpc and chx into the fuji ix 's powder and bc to the liquid at 1 to 4% final
concentrations , caused a decrease in compressive strength to varying degrees compared to
the control group .
furthermore , no
data are available in the literature about the surface hardness alterations of such fuji
ix - antibacterial combinations compared to additive - free material , which could improve
the durability of the restoration in clinical conditions .
microhardness testing can be performed to evaluate the state of gics at various storage
times , since they are very sensitive to water sorption .
samples kept in contact with water , either in a humid atmosphere or completely immersed ,
are characterized by lower flexural strength , lower modulus of elasticity and softer
surfaces than dry samples.thus , the
present study also aimed at determining the surface hardness alterations according to
fuji ix - antibacterial combinations stored in water for up to 90 days .
( 2002 ) reported that
with regard to the knoop hardness number ( khn ) , no significant differences were found
between the photac - fil and photac - fil - chx in the first week . at 6 weeks
, khns increased
in both groups , but this increase was clearer in the photac - fil group compared to the
photac - fil - chx group .
nevertheless , they concluded that at neither 24 h- nor 6
week - periods , the physical properties altered seriously .
their study was the first to
analyze microhardness values in gic - antibacterial combinations .
in the current study ,
all experimental groups showed a decreasing trend in vhns of the fuji ix gic after the
7-day period and this trend exhibited significant differences during these periods for
all experimental groups .
this may be attributed to the sensitivity of fuji ix to the
antibacterial agents used in this study compared to photac - fil and/or to the medium in
which the samples were stored . in another study ,
trkn , et al.25
( 2008)tested 0.5% , 1.25% and 2.5% diacetate or digluconate chx
concentrations with chemfil superior regarding the vhn .
they found significantly reduced
hardness in the 0.5% chx digluconate and 2.5% chx digluconate groups compared to chemfil
superior at 24 h. after the 10 days setting period , all of the tested groups except for
the 2.5% digluconate demonstrated hardness comparable to the original chemfil superior
group .
this is a consequence fact that there was no remarkable leakage of chx particles
out onto the surface . in this study
the results
were explained by the well - known maturation reactions in these cements .
moreover , where
additives were present , this increase was most marked in the 1% bc and 1% chx groups .
also , between these groups , significant differences were not observed at 7 and 15 days
periods ( p>0.05).thus , it can be assumed that , these groups may exhibit similar
outcomes when they are incorporated to the fuji ix .
additionally , in a previous study , it was reported that the increase of vhn values of
fuji ix samples was more accentuated in the intervals between 1 - 7 days .
also , the
increase was found to be more uniform between the 7 and 30 days .
however , in the present study , after
the 7-day period , contrary to the previous findings , the vhns decreased in
all experimental groups ( p<0.05 for all individual group ) , whereas they continued to
increase in the antibacterial free fuji ix control group ( p<0.05 ) as reported
elsewhere .
this may be
attributed to the water storage conditions of the samples , and day 7 is the critical
point for the fuji ix - antibacterial samples .
( 2001 ) reported that when fuji ix was stored in water ,
it showed significantly increased vhns between days 1 and 40 . in the present study ,
water probably eroded the fuji ix - antibacterial combinations and caused the dissolution
of some components , which would certainly decrease the surface hardness .
thus , except
for the control group , a plasticizing effect could have occurred in the experimental
groups and the continuous setting reaction may have been influenced by the foreign
particles in the matrix of the fuji ix up to 90 days .
this may indicate that certain antibacterial agents may
have negative effects on the hardness properties of cements particularly in the ongoing
cement reaction .
thus , to avoid from the clinically mechanical failure problems in
gic - antibacterial combinations these findings could be taken into account for future art
procedures.regarding the surface hardness values , between the 1% ct and 1% cpc groups
significant differences were not found at all time periods ( p>0.05 ) . moreover ,
2% ct
and 2% cpc had the greatest adverse effects on surface hardness values of the fuji ix
samples after 30 days ( table 1 ) .
these results
suggest that ct and cpc groups are likely to be partner and less resistant to occlusal
loads in clinical situations than the parent cement .
this result may also support the
previous findings of botelho
( 2004 ) . considering the above - mentioned studiesand within the
limitations of this in vitro study ,
our findings could be interpreted
as tolerable , particularly when using these antibacterial agents at these
concentrations .
although significantly reduced hardness values were found in the
experimental groups compared to the controls , they were able to be measured .
all
previous reportsand our findings may give an indication about the
incorporation of the antibacterial agents to the gics resulting at softened but
measurable surfaces compared to the additive - free material .
in addition , the vhns obtained in the present study showed similar trends to that of
compressive strength reported previously .
higher levels of additive had greater effect on the vhns compared to
the controls , showing that the decline in physical properties is related to additive
concentration . however , at levels of 1 and 2% , although significant differences were
found , the decline was acceptable , and might not be sufficient to cause a large
reduction in overall durability of the restoration in clinical conditions .
overall , it
seems that the combination of ct , cpc , chx and bc with fuji ix at concentrations of 1%
and 2% produces cements with tolerable setting and hardness properties for clinical use .
additionally , within the in vitro limitations of this study , adding chx
and bc to the fuji ix gic seems to provide appropriate physical properties compared to
ct and cpc combinations .
incorporation of the antimicrobial compounds ct , cpc , bc and chx at 1% and 2%
concentrations into the conventional gic fuji ix was found to have measurable effects on
the surface hardness .
the resulting cements had reduced hardness , as determined by vhn
measurements , and hardness decreased after 7 days , unlike the additive - free control ,
which continued to increase in hardness up to 90 days . however , in general , all
experimental groups exhibited tolerable physical properties . moreover ,
1% bc and 1% chx
groups were detected as the most suitable combinations whereas 2% ct and 2% cpc shoed
almost adverse effects . as a result of this in vitro study , the tested
antibacterial materials could be used with fuji ix at varying concentrations in art
procedures .
further investigations are needed to evaluate the most appropriate fuji
ix - antibacterial combination that may not affect the physical properties of fuji ix in
clinical situations . | ### Summary:
: in atraumatic restorative treatment ( art ) , caries removal with hand excavation
instruments is not as efficient as that with rotary burs in eliminating bacteria
under the glass ionomer cements ( gics ) .
thus , different antibacterial agents have
been used in recent studies to enhance the antibacterial properties of the gics ,
without jeopardizing their basic physical properties .
objectivethe objective of this study was to evaluate the effect of antibacterial agents on
the surface hardness of a conventional gic ( fuji ix ) using vickers microhardness
[ vickers hardness number ( vhn ) ] test .
material and methodscetrimide ( ct ) , cetylpyridinium chloride ( cpc ) and chlorhexidine ( chx ) were added
to the powder and benzalkonium chloride ( bc ) was added to the liquid of fuji ix in
concentrations of 1% and 2% , and served as the experimental groups .
a control
group containing no additive was also prepared .
after the completion of setting
reaction , vhn measurements were recorded at 1 , 7 , 15 , 30 , 60 , and 90 days after
storage in 37c distilled water .
a one - way anova was performed followed by a
dunnett t test and tamhane t2 tests and also repeated measurements anova was used
for multiple comparisons in 95% confidence interval .
resultsvhn results showed significant differences between the control and the
experimental groups at all time periods ( p<0.05 for all ) .
significant
differences were observed between all study periods for individual groups
( p<0.05 ) .
after 7 days , vhns were decreased in all experimental groups while
they continued to increase in the control group .
bc and chx groups demonstrated
the least whereas ct and cpc groups exhibited most adverse effect on the hardness
of set cements .
conclusionsdespite the decreased microhardness values in all experimental groups compared to
the controls after 7 up to 90 days , incorporating certain antibacterial agents
into fuji ix gic showed tolerable microhardness alterations within the limitations
of this in vitro study . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: cancer , as one of the health problems , has a rapid ascending trend in the world , and is counted as the second cause of mortality in the world . in iran , it is the third cause of mortality .
based on who prediction , incidence of cancer in iran will reach 85,000 cases from all population with mortality rate of 62,000 in year 2020 .
cancer is a common problem among the elderly . with regard to the increasing trend of older adults population in the world ( with an increase from 605 million in year 2000 to 2 billion in 2050 ) , the number of cancer patients is expected to increase . in usa ,
older adults comprise almost 60% of the 11 million cancer patients . in iran , cancer is the third mortality cause , and who reports its annual mortality as 12% .
breast cancer is the most common cancer among women . in year 2013 , 234,000 new cases of breast cancer were reported in us , of which 39,000 led to death .
prostate cancer is the second known cancer in men with the highest rate in developed countries and the lowest in far east countries . in 2013
, almost 238,000 new cases of prostate cancer were reported in us of which 29,000 resulted in death . not only cancer itself but also its complications and side effects of the treatments , as well as length of disease , can have numerous negative effects on patients function and quality of life ( qol ) .
various studies showed that cancer and its treatment can result in physical , emotional and social pressure that lead to a reduction in function , incidence of sexual function disorder , and a change in body image , followed by probable structural changes , a reduction in self - confidence and possibility of familial , emotional , and economic problems , anxiety and suffering from psychological problems , and a severe reduction in psychological and physical function that can influence qol of the individuals and their families .
long - term complications of treatment such as incontinence , sexual disability , and inflammation of the rectum due to radiotherapy have negative effects on the elderly .
various treatments are administered for the patients with different goals to control the signs , relieve pain , prolong life and improve qol , but they can not fulfill all patients needs . therefore , using complementary methods to reduce patients problems seems necessary . with regard to the high prevalence of cancer among the elderly , incidence of numerous complications due to cancer and its treatment ,
high costs of treatment , severe effects of the disease and trend of treatment on their physical and psychological conditions , non meditational methods can be adopted .
one of the basic and low - risk interventions , which can be used parallel to the treatment for these patients , is complementary or alternative medicine .
using different methods of complementary , alternative medicine is more common among cancer patients , compared to other patients .
research showed that adopting such methods can affect sign and complications control among cancer patients . on the other hand , these methods are the most cost effective , efficient and functional methods and have lower complications and are less invasive and addictive , and more accessible , compared to other treatments .
these methods can improve qol , as a goal of who in its program of
health for all , through causing an increase in the years of patients life . it should be also noted that although cancer patients need support , physicians do not fulfill their needs as they should .
one of the complementary medicine methods is using behavioral intervention such as progressive muscle relaxation and body mind interventions such as guided imagery .
progressive muscle relaxation is a physical stimulation and mental peace with emphasis on muscle systematic stretching and release ( contraction - release )
. progressive muscle relaxation can be applied in all stages of cancer patients and can notably reduce cancer complications .
guided imagery is also one of the complementary medicine methods that can be applied in different conditions and in various populations to improve qol and reduce cancer pain .
guided imagery of beautiful and attractive views causes endorphins to release in the body leading to feeling of peace and removal of stressful thoughts , and consequently , feeling of euphoria .
deep diaphragmatic breathing is a sort of purposive smoother , deeper and standard breathing through which the person achieves peace and comfort and is one of the relaxation methods that provides the body with more oxygen .
good respiration behaviors increase individuals ability to cope with physical tension and lead to stress management .
with regard to the reduction in qol of the older adults with cancer and aging trend of population in iran as well as high prevalence of breast or prostate cancers in iranian older adults , the necessity of applying such non meditational methods in these patients with no complications is of paramount importance . on the other hand , about no side effects in non meditational method , and their positive effects on qol , nurses can use these methods for the patients . as no study has investigated concurrent application of three methods of complementary medicine in older adults with cancer so far , the present study aimed to define the effect of progressive muscle relaxation , guided imagery and deep diaphragmatic breathing on qol of the older adults with breast or prostate cancer .
this is a two - group three - stage clinical trial , conducted in seyed - al - shohada university hospital in isfahan , iran in 2013 .
effect of concurrent guided imagery , progressive muscle relaxation and deep diaphragmatic breathing on qol in the elderly with cancer was investigated before , immediately after and 6 weeks after the intervention in study and control groups . with regard to similar studies and consideration of test power of 0.80
, the number of the subjects was calculated 25 in each group ( n = 25 , n = 25 ) .
inclusion criteria were age over 65 years , involvement in breast or prostate cancer , not undergoing chemotherapy , absence of any metastasis and adequate physical ability to administrate relaxation techniques .
exclusion criteria were progression of the disease , incidence of metastasis , beginning of advanced treatments such as chemotherapy , radiotherapy , and surgery , and any physical disability occurring among the subjects preventing the intervention .
firstly , based on inclusion criteria , the subjects were selected through convenient sampling , and then , were assigned to study and control groups through random allocation . word study and
control were written on two cards , which were put into a bag .
a person , unaware of the research , was asked to take out one the cards and the subjects were assigned to either control or study group accordingly .
data were collected by a two - section questionnaire and referring to patients medical files .
the first section of the questionnaire was on demographic characteristics , and the second was qol questionnaire of european cancer organization .
this multi - dimensional questionnaire contained 30 item of qol in five functional domains ( physical , role play , emotional , cognitive , and social ) , nine domains of signs ( fatigue , pain nausea and vomiting , respiration distress , diarrhea , constipation , loss of sleep , loss of appetite and economic problems due to the disease ) , and one general domain of qol .
scoring of two items of general qol was based on a seven - point likert 's scale , and the rest , based on a four - point likert 's scale . during data analysis stage , the scores were calculated between 0 and 100 . in functional and general domains of qol
this questionnaire has been frequently adopted in domestic and international studies and enjoys an established validity and reliability .
study of safaei and tabatabaei in which cronbach alpha = 0.7 showed a proper reliability .
first of all , the goal of the study was explained , and adequate information was given to the patients and their accompanying persons , and an informed written consent was obtained from them .
they were assured about the confidentiality of their data and their right to leave the study whenever they liked .
then , the subject filled the questionnaire with the help of his / her accompanying person . in study groups ,
the subjects were asked to attend an appropriate place in the hospital with one of their caregivers .
attendance of the caregiver was obligatory due to subjects high age and their need to be assisted in learning .
the subjects in study group were divided into two groups of eight members and one group of seven members .
education and practice sessions were separately held for each group in form of eight 45-min sessions during four sequential weeks as shown in table 1 .
education and practice sessions in study group in the present study , progressive muscle relaxation referred to contraction and release of muscles for eight groups of muscles ( lower hand , upper hand , lower leg and upper leg , abdomen , shoulders , lower chest and upper forehead ) , showed to the subjects through data show while being asked to imitate the practice .
in deep diaphragmatic breathing technique , the subjects were asked to be in a comfortable position and to put one hand on the abdomen and the other on their chest .
the subjects were asked to gently breathe through their nose , gently count until number four while inhaling and feel their abdomen rising with their hand .
then , after number four , they gently exhaled , and waited for 4 s before next inhalation .
guided imagery was conducted in a way that firstly , pictures from relaxing sceneries were shown to the patients , and they were asked to visualize the scenery that was the most pleasant to them for 1015 min .
the subjects in study group were asked to conduct this technique at least twice a day at home . after a 1-month education and practice period ,
the researcher followed - up correct administration of the techniques through phone calls and getting information from the patients caregivers .
after 6 weeks , qol questionnaire was completed once more in study group . in control group , three usual sessions on lifestyle and life experiences were conducted , and qol questionnaire was filled concurrently with study group before , immediately after and 6 weeks after the intervention .
data were analyzed by paired t - test , independent t - test , and repeated measures anova through spss 20 ( ibm corp .
demographic characteristics showed that both groups were homogenous concerning the demographic characteristics ( there was no significant difference ) as shown in table 2 .
demographic characteristics of the subjects in study and control groups independent t - test showed no significant difference in mean scores of functional domains before intervention between two groups ( p = 0.88 ) , but showed a significant increase in mean scores of functional domains in study group immediately after ( p < 0.001 ) , and 6 weeks after intervention ( p < 0.001 ) [ table 3 ] .
repeated measure anova showed no significant difference in mean scores of qol in functional domains between 3 times points in the control group ( p = 0.87 ) . in study group
least significant difference ( lsd ) post hoc test showed that mean score of functional domain of qol was significantly higher immediately after intervention , compared to before ( p < 0.001 ) , and 6 weeks after intervention , compared to immediately after respectively ( p < 0.001 ) . determination and comparison of the differences in the mean scores of functional domains of qol between two groups before , immediately after and 6 weeks after the intervention repeated measure anova showed that mean scores of qol overall domain were not the same in study group ( p < 0.001 ) .
lsd post hoc showed that mean scores of qol overall domain were significantly higher immediately after intervention , compared to before ( p < 0.001 ) and 6 weeks after , compared to immediately after intervention respectively ( p < 0.001 ) .
repeated measure anova showed that mean scores of qol overall domain were not the same in 3 times points ( p < 0.001 ) in control group , but lsd post hoc showed that mean score of qol overall domain was significantly less after intervention , compared to before intervention ( p < 0.001 ) , and 6 weeks after intervention , compared to immediately after ( p < 0.001 ) .
independent t - test showed no significant difference in mean scores of qol overall domain between two groups before intervention ( p = 0.093 ) , but after intervention ( p < 0.001 ) and 6 weeks after ( p < 0.001 ) , mean scores of qol overall domain were significantly more in the study group , compared to control group [ table 4 ] .
determination and comparison of the differences in the mean scores of general domain of qol between two groups before , immediately after and 6 weeks after intervention
the results showed that mean scores of functional and overall domains of qol had a significant difference immediately after and 6 weeks after the intervention in study group , compared to control .
it shows the positive effect of concurrent application of three relaxation techniques of progressive muscle relaxation , guided imagery and diaphragmatic deep breathing on improvement of qol in the older adults with breast or prostate cancer .
cheung et al . , in a study on the effect of progressive muscle relaxation in cancer patients on reduction of anxiety signs and improvement of various domains of qol in gastric cancer patients undergoing surgery , reported positive effects .
kwekkeboom et al . , in a study on the effect of two concurrent progressive muscle relaxation techniques and guided imagery on pain score of cancer patients , reported positive effects for both techniques .
investigating the effect of progressive muscle relaxation on qol in cardiac patients after surgery , showed that this technique improved qol in noncancer patients after surgery .
results of the present study , in line with other studies , showed that scores of qol in functional and overall domains were significantly different 6 weeks after intervention , compared to immediately after , revealing better effect of applying three concurrent techniques of progressive muscle relaxation , guided imagery , and deep diaphragmatic breathing . in progressive muscle relaxation
, mind learns to concentrate on different body organs and be separated from the environment through this concentration , release and reduce muscular tension , and consequently , achieve peace and comfort .
beautiful and attractive pictures cause endorphins release in the body that leads to removal of stressful thoughts and achieving peace , and finally , feeling of euphoria .
this technique , as a good respiration behavior , increases individuals ability to manage stress , especially physical tension . based on the aforementioned explanations , all three techniques naturally lead to an improvement in qol functional and overall domains .
our results showed that mean scores of qol functional and overall domains were not significantly different between study and control group before intervention , but immediately after and 6 weeks after , the difference was significant .
reported that guided imagery and progressive muscle relaxation were effective on reduction of chemotherapy complications and improvement of qol in cancer patients .
application of various and concurrent methods has a better effect , compared to applying each method alone .
sloman showed that progressive muscle relaxation and guided imagery had positive effects on depression of cancer patients . in their study , both techniques of relaxation and guided imagery were applied once separately and once concurrently in different groups .
results showed that the concurrent application of both techniques had a higher effect on qol and depression of cancer patients .
the difference between the present study and their study is just application of concurrent three techniques of progressive muscle relaxation , guided imagery and diaphragmatic deep breathing .
on the other hand , application of a single complementary medicine method has yielded controversial results .
showed that relaxation practices had no effect on qol of cancer patients undergoing chemotherapy . in their study , the patients were intervened after chemotherapy , and the only method was relaxation .
meanwhile , in the present study , not only three concurrent techniques were adopted , but also group education and having accompanying persons were among the differences between the present and other studies .
different socio - cultural contexts in different countries can affect people 's behavior and reactions .
therefore , individuals responses to different relaxation techniques can be different , which needs further studies to be conducted in other countries .
selection of the appropriate time to administrate these techniques is also important as aswadi - kermani et al
. showed that relaxation had no effect on stress , anxiety and qol of the patients undergoing chemotherapy as the complications of chemotherapy are so high that relaxation techniques have no effect on patients recovery and improvement of qol .
hard work with older adults with cancer and their psychological and physical conditions in response to relaxation methods as well as their personal , psychological , and environmental differences and cultural level , their understanding from health , and consequently , their qol scores , which might have affected our results , can be named as the limitations in the present study .
the results showed that progressive muscle relaxation , guided imagery , and deep diaphragmatic breathing are effective on improvement of qol in breast or prostate cancer patients , and can be suggested as a cost - effective and convenient treatment .
these methods can complete the main treatments and n relieve cancer patients and improve their qol . as nurses can learn these techniques and apply them for their patients , holding related educational workshops to apply such complementary treatment methods for cancer patients recommend for the nurses .
| ### Summary:
: background and objectives : due to the increasing number of elderly and an increase in the number of cases of cancer by age , cancer is a common problem in the elderly . for elderly patients with cancer , the disease and its treatment can have long - term negative effects on their quality of life ( qol ) .
the purpose of this study was to evaluate the effect of progressive muscle relaxation , body image and deep diaphragmatic breathing on the qol in the elderly with cancer.materials and methods : this study was a randomized controlled trial in which 50 elderly patients with breast or prostate cancer were randomized into study and control groups .
progressive muscle relaxation , guided imagery , and deep diaphragmatic breathing were given to the study group , but not to the control group .
the effect of the progressive muscle relaxation , guided imagery and deep diaphragmatic breathing was measured at three different time points .
european organization for research and treatment of cancer and qol questionnaire - core questionnaires was completed before , after and 6 weeks after the intervention for the patients in both groups simultaneously .
the data were analyzed by spss.results:there was statistically significant improvement in qol ( p < 0.001 ) and physical functioning
( p < 0.001 ) after progressive muscle relaxation , guided imagery and deep diaphragmatic breathing intervention.conclusions:the findings indicated that concurrent application of progressive muscle relaxation , guided imagery , and deep diaphragmatic breathing would improve qol in the elderly with breast or prostate cancer . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth.1 the etiology of supernumerary teeth is not completely understood .
various theories exist for the different types of supernumerary teeth.2 one of the theories proposes that the supernumerary tooth is produced because of a dichotomy of the tooth bud.3 another theory - the hyperactivity theory - suggests that they are formed because of local , independent , conditioned hyperactivity of the dental lamina.4 genetics may also influence the development of supernumerary teeth.5 supernumerary teeth may be classified based on form ( conical type , tuberculate type , supplemental type , odontome ) or position ( mesiodens , paramolar , distomolar , parapremolar).6 the clinical complications of supernumerary teeth include root anomaly , malocclusion , root resorption , displacement or rotation , failure of eruption or delayed eruption of adjacent tooth , cyst formation , and pulp necrosis with loss of vitality and esthetic disturbances.7 the most common supernumerary teeth , listed in order of frequency , are the maxillary midline supernumeraries ( mesiodens ) , maxillary fourth molars , maxillary paramolars , mandibular premolars , maxillary lateral incisors , mandibular fourth molars , and maxillary premolars.8 the occurrence of multiple supernumerary teeth is often found in association with syndromes such as gardner s syndrome , fabry anderson syndrome , ellis van creveld syndrome , ehlers danlos syndrome , incontinentia pigmenti and tricho - rhino - phalangeal syndrome and developmental disorders such as cleft lip and palate and chondroectodermal dysostosis.9 the presence of supernumerary teeth may be associated with familial tendency.10 only a few examples of long - term follow - up of nonsyndromal bilateral supernumerary teeth have been reported in the literature.11 the aim of this study is to present an unusual case of a non - syndrome female patient with bilateral supernumerary teeth which occurred with an interval of several years .
a 9-year - old female patient presented to our clinic complaining of pain in her primary teeth .
an intraoral examination showed that the patient had a class i canine relationship on the right and left side and bilateral posterior crossbite due to bilateral constriction of the maxilla .
a panoramic survey of the teeth showed an unerupted super - numerary tooth that was located on the left side of the maxillary arch ( figure 1b ) .
a standard maxillary occlusal radiograph was taken to determine the position of the unerupted tooth .
the radiograph showed that the tooth was in a palatal position ( figure 1c ) .
following local anesthesia , a sulcular incision was performed and the supernumerary tooth was extracted via a palatal approach .
the patient refused fixed orthodontic treatment and it was decided to observe the teeth and review the patient during the follow - up period . in the second follow - up period , after 3 years , radiographic examination revealed the presence of an unerupted supernumerary tooth in a palatal position on the right side of the maxillary arch ( figure 1d ) .
supernumerary teeth can be defined as the teeth present in addition to the normal set of teeth .
rajab and hamdam12 reported that the most frequent supernumerary teeth identified were mesiodens , followed by premolars , and fourth molars or distal molars .
however , authors such as menarda et al13 reported that the supernumerary teeth of the molar group are the most prevalent type in the general population . in the present case ,
2 supernumerary premolar teeth were located on the left and right side of the maxillary arch .
supernumerary teeth are considered one of the most common dental anomalies , affecting the primary and early mixed dentition.12 the etiology of supernumerary teeth remains unclear , but several theories have been suggested for their occurrence .
the localized and independent hyperactivity of the dental lamina is the most accepted cause for the development of supernumerary teeth .
some have proposed that supernumerary teeth are formed as a result of local , independent , and conditioned hyperactivity of the dental lamina.14 the incidence of supernumerary teeth is reported to be between 0.1 and 3.6% of the general population.15 rajab and hamdan12 reported in their study that males were more frequently affected than females ( sex ratio , 2.2:1 ) .
altug et al17 concluded that males are much more frequently affected than females with a 1.25:1 ratio .
supernumerary teeth are more likely to be present in patients whose relatives possessed supernumeraries , although the inheritance of these teeth does not follow a simple mendelian pattern.18 batra et al5 recently reported the presence of multiple supernumerary teeth occurring as a nonsyndromic trait in a girl , her elder brother , and her father . in reviewing the literature ,
only a few cases of multiple supernumerary teeth were found without any associated syndromes or systemic disorders.5,8,10,19 in the present case , a non - syndrome female patient with bilateral supernumerary teeth was present .
what is important is that this paper reports a case of nonsyndromic bilateral supernumerary teeth .
the importance of the use of a panoramic radiograph to evaluate a patient s condition is emphasized whenever a supernumerary tooth is detected , irrespective of whether the patient has any syndrome or not.19 we observed the first supernumerary tooth during routine panoramic radiography by chance .
this case also shows how important the follow - up period is . whenever supernumerary teeth are diagnosed , single or multiple , a decision regarding appropriate management should be carefully considered .
spontaneous eruption following supernumerary removal is suggested to be in the range of 5475%.20 dibiase21 has suggested that most teeth experiencing delayed eruption will spontaneously erupt within 18 months of supernumerary removal alone , provided the delayed tooth is not excessively displaced .
the first option involves removal of the supernumerary as soon as it has been diagnosed .
this could create dental phobia problems for a young child and has been reported to cause devitalization or deformation of adjacent teeth .
secondly , the supernumerary tooth could be retained until root development of the adjacent teeth is complete .
the potential disadvantages associated with this deferred surgical plan include loss of eruptive force of adjacent teeth , loss of space and crowding of the affected arch , and possible midline shifts .
obviously , the position , size , and nature of the supernumerary tooth and the level of co - operation of the patient will influence the surgical difficulty ; hence , each case should be individually assessed . in our opinion , it is important to initiate appropriate consultation and an interdisciplinary approach for treatment .
additionaly ; we emphasized that in cases of supernumerary teeth the follow - up period and interdisciplinary approach are very important for treatment . | ### Summary:
: the presence of supernumerary teeth , also known as hyperdontia , is the condition of having teeth in addition to the regular number of teeth .
the occurrence of multiple supernumerary teeth is often found in association with syndromes such as gardner syndrome , anderson - fabry disease , ellis - van creveld syndrome , ehlers - danlos syndrome , incontinentia pigmenti , and tricho - rhino - phalangeal syndrome .
only a few examples of nonsyndromic multiple supernumerary teeth have been reported in literature . in this report
, we present the unusual case and 9-year follow up of a non - syndrome female patient with bilateral supernumerary teeth that occurred with an interval of several years . |
<s> [INST] <<SYS>> You a helpful assistant capable of providing accurate and concise responses. You will assist me in generating Summary.<</SYS>> [/INST] <s> ### Text:
: the general internist , allergist , and pulmonologist commonly encounter adult patients with clinical features of both asthma and chronic obstructive pulmonary disease ( copd ) . differentiating
the underlying cause of their symptoms becomes difficult and often leads to blanket therapy directed towards airway hyperreactivity ( ahr ) , airway inflammation , airflow obstruction , and allergic disease .
a salient example is an older patient with a history of seasonal allergies and asthma , a current or past smoking history , and progressive symptoms of acute - on - chronic dyspnea .
they may demonstrate fixed airflow obstruction or partial reversibility on spirometric testing , an elevated total ige , and a slightly increased nitric oxide level .
does such a patient have copd with ahr , remodeled asthma that has progressed to partially reversible or fixed airflow obstruction , or overlapping copd and asthma the so - called asthma - copd overlap syndrome ? is some degree of airflow obstruction simply related to natural aging of the lung ( a decline in fev1 exceeding the predicted 25 to 30 ml per year ) , and should this be treated ?
these questions beget further questions regarding the need to distinguish the components of asthma - copd overlap and the associated treatment implications , including drug side effects , compliance , and variable response to drug therapy with advancing age .
this becomes even more relevant in the elderly population where the overlap syndrome is prevalent . in this paper
we review the data which address the biologic , clinical , and diagnostic differences between asthma and copd .
we will also highlight several areas of overlap between these disorders supporting the need to clinically define this subgroup of patients with obstructive lung disease .
further , we aim to define the overlap syndrome based on the current understanding in the literature and our clinical experience and practice , while underscoring the challenges that remain in understanding this important entity .
ultimately , we propose a work - up and treatment algorithm which fits our patient population , and we raise important questions for future studies needed to advance the recognition and management of asthma - copd overlap .
in theory , asthma and copd are different diseases each with a unique natural history and pathophysiology .
the british hypothesis holds that asthma and copd are distinct diseases that develop by unique mechanisms .
it is widely accepted that asthma generally manifests as intermittent and reversible airway obstruction , whereas copd is progressive and irreversible [ 24 ] .
based on current guidelines , the postbronchodilator response in asthma shows complete reversibility of airway obstruction . in copd , there is either no reversibility ( i.e. , fixed obstruction ) or there is partial reversibility of airway obstruction following bronchodilator , described as copd with partial reversibility . in this latter entity , one can demonstrate reversibility as an improvement in lung function , but the patient remains obstructed on spirometric measurements ( hence , the designation of copd rather than asthma ) . preserved carbon monoxide diffusion capacity ( dlco ) on pft and a higher ratio of airway - to - lung parenchymal abnormalities ( on lung imaging by high - resolution chest tomography ) may also distinguish asthma from copd .
clinically , the distinction between asthma and copd is most apparent at the extremes of age , where younger patients tend to have more asthma symptoms and older patients ( age > 60 ) tend to have copd symptoms .
a history of cigarette smoking and evidence of emphysema in an older patient with spirometric airflow obstruction would favor copd .
a nonsmoking younger patient with a history of childhood asthma or wheezing and atopy with reversible airflow obstruction would favor asthma .
though symptoms can often overlap , beeh and colleagues developed a questionnaire to differentiate asthma and copd . on a scale of 1 to 15 , the questionnaire performed best at a cutoff of 7 with a sensitivity of 87.6% for copd , though ~20% of patients had overlap features ( scores 68 ) . practically speaking for the clinician ,
major differences exist in the structural and inflammatory signatures of asthma and copd when studied in isolated , well - defined populations [ 912 ] .
these include elevated ige , induction of th2 cells , eosinophilic infiltration , reticular basement membrane thickening , and smooth muscle hyperplasia in asthma .
in contrast , increased neutrophils , induction of th1 and th17 cells , tgf-induced small airway fibrosis , goblet cell hyperplasia , and mmp elastic tissue destruction are typically found in copd [ 13 , 14 ] .
bronchoscopic endobronchial biopsies have shown smooth muscle cell hypertrophy and chronic inflammation in asthma [ 10 , 15 , 16 ] .
though there are major histologic differences between asthma and copd , endobronchial biopsy is not widely used in the workup and management of obstructive lung disease as the risk - benefit profile is often unfavorable .
animal and human studies suggest that cytokine profiles may be used to help distinguish between asthma and copd .
however , these data also indicate that a disease continuum exists in some patients with elements of both diseases .
ongoing research using exhaled nitric oxide and other exhaled biomarkers may provide reliable biological parameters to aid in diagnosis [ 1922 ] .
existing treatment options for asthma and copd highlight some important differences [ 23 , 24 ] .
for example , copd with reduced dlco may qualify for supplemental oxygen therapy and referral to a pulmonary rehabilitation program [ 26 , 27 ] .
severe allergic asthma with an appropriate high level of serum ige may qualify for treatment with omalizumab [ 28 , 29 ] , and , in those with allergic asthma not well controlled on ics , leukotriene receptor antagonists or 5-lipoxygenase inhibitors may improve symptoms .
bronchial thermoplasty , a novel therapy that uses endobronchial radiofrequency ablation to reduce airway smooth muscle mass , reduces asthma symptoms and rates of exacerbation .
however , the link between clinical classification or diagnosis , pathophysiology , and guideline - based treatments can be opaque in practice due to the lack of simple tests that can reliably distinguish the two diseases .
typical symptoms of dyspnea , wheezing , or cough do not have the sensitivity or specificity to distinguish these two disorders among older adults after excluding comorbid conditions such as heart failure , diastolic dysfunction , aspiration , gerd , or vocal cord dysfunction . according to soriano et al . , asthma and copd are difficult to differentiate because ( 1 ) the conditions are viewed as part of a disease continuum ; ( 2 ) they have strong overlapping features ; ( 3 ) there is no incentive to differentiate whether their treatment and prognosis are the same ; ( 4 ) there is a lack of clear guidelines as to how the distinction can be made in clinical practice ; ( 5 ) uncertain criteria are used by physicians to classify patients as having asthma or copd . despite years of research and the prolific expansion of guidelines from both european and american respiratory societies , distinguishing these two common diseases remains a daunting challenge .
recent reviews underscore the pitfalls in diagnosis , management , and treatment of overlap syndrome , asthma , and copd [ 3235 ] .
the dutch hypothesis maintains that asthma and ahr predispose patients to develop copd later in life and that asthma and copd are different expressions of a single disease ( based on the timing of environmental and epigenetic influences amidst a common genetic background ) .
some authorities argue that obstructive lung disease is a progressive disease that begins in early childhood , where copd is the final manifestation .
recent epidemiologic findings , from a long - term cohort study in the united states , point to asthma as a significant risk factor for the future development of copd . unless there are clear exposures , such as a prolonged smoking history in a person with severe emphysema
, clinicians recognize that considerable phenotypic heterogeneity makes clear distinctions between obstructive lung diseases problematic [ 38 , 39 ] .
these challenges are nicely demonstrated by a series of pro - con debates between kraft and barnes [ 40 , 41 ] .
not all comparisons between asthma and copd pathology show unique structural differences . in 100 select patients with clinically determined asthma and copd who underwent endobronchial biopsies , there were no statistically significant differences in key pathologic features .
though eosinophilic infiltration and basement membrane thickening were associated with asthma , the overall differences in these features , metaplasia , and epithelial inflammation did not allow for pathologic differentiation . airway remodeling and
the lung 's specific repair responses may account for some of the pathological similarities reported in asthma and copd [ 42 , 43 ] .
up to 50% of copd patients can have ahr due to the narrowing of their distal airways and predisposition to bronchospasm
. however , fabbri et al . showed that despite a similar degree of fixed airway obstruction , asthmatic and copd airway inflammation and structural changes do not appear the same .
but as imaging and airflow resistance assessment techniques improve , the small airway changes associated with asthma and copd which appear dissimilar may result in a phenotypically similar outcome .
limitations inherent to the different patient cohorts studied and research methodologies used may confound and limit final conclusions regarding a clear histopathologic - physiologic link . asthma and copd can overlap in their inflammatory sputum profiles and lung function . severe bronchial asthma with fixed obstruction has an increased number of neutrophils similar to copd .
eosinophilic inflammation in copd may play a substantial role and be associated with greater postbronchodilator reversibility .
chronic bronchitis or emphysema patients with airway eosinophilia demonstrate increased airway reversibility and respond more readily to corticosteroid therapy [ 4749 ] . in smokers with severe obstructive bronchitis , sputum eosinophilia predicts a beneficial response to prednisone treatment .
evidence of bronchodilator response ( i.e. , reversibility ) or ahr may be an important measure not only for diagnosis but also for prognosis with respect to the rate of lung function decline and asthma mortality [ 51 , 52 ] . however , not all studies agree that bronchodilator responses correlate with the subsequent rate of lung function decline .
some authors found that the prognosis in terms of all - cause mortality is strongly correlated with age , smoking , and the best attainable fev1 regardless of reversibility .
given that overlap features become prevalent with increasing age and a smoking history , there are important implications for prognosis regarding this syndrome .
according to diaz - guzman et al . , the treatment of asthma and copd in older adults does not differ from available guidelines but may be complicated by the presence of comorbidities .
however , this position fails to grasp the highly variable response to anti - inflammatory ics therapy in copd and in asthma where up to 46% of older patients with moderate disease do not respond at all to beclomethasone .
the long - term consequences in nonresponding asthmatics chronically treated with ics are largely unknown but may predispose this cohort to more frequent acute exacerbations and lung function decline over time .
this is complicated in the elderly adult who may have overlap features and does not respond to therapy .
asthma - copd overlap may have origins in childhood , for example , infections , atopy , and tobacco - smoking exposure ( figure 6 ) but escapes earlier diagnosis because of current definitions and guideline - based approaches to chronic obstructive lung diseases .
this could result in a heuristic bias potentially overlooking patients in their 40s and 50s with overlap syndrome by labeling them as lone
this becomes even more relevant in the elderly population ( age 65 years ) where the overlap syndrome is increasingly recognized because of variable response to guideline drug therapy , more frequent healthcare resource utilization [ 3235 , 56 ] , and multiple comorbid conditions .
it is a syndrome in which older adults with a significant smoking history have asthmatic features to their chronic obstructive airway disease .
there are many cases of pathologic and functional overlap between asthma and copd , yet authorities debate whether this overlap syndrome represents the coexistence of two common airway diseases or whether there are common underlying pathogenic mechanisms leading to this common phenotype .
overlap syndrome appears to share many of the same disease risk factors as that of asthma and copd ( figure 6 ) .
this is a major challenge to our understanding of pathogenesis ; however , this observation can guide future basic studies and the development of novel therapies .
for example , gibson and simpson defined overlap syndrome as asthma and copd , that is ,
symptoms of increased variability of airflow and incompletely reversible airflow obstruction , but this is rather limited when based solely on fev1 and bronchodilator response .
for example , patients with copd can demonstrate a variable and significant degree of reversibility of airflow obstruction following bronchodilator challenge .
nearly 66% of copd patients in the uplift trial improved their fev1 by more than 15% after receiving 80 g ipratropium and 400 g of salbutamol , yet they were not considered to have overlap syndrome or concomitant asthma .
thus , a clear definition remains elusive regarding overlap syndrome since there is no consensus in the literature .
moreover , the presence of exercise intolerance and static or dynamic hyperinflation and indices of pulmonary emphysema in the aging patient may be important factors to include when considering overlap syndrome a complex question needing further research .
few studies have specifically investigated the asthma - copd overlap syndrome [ 3 , 7 ] .
patients with coexisting asthma and copd present similarly to pure asthma or copd , manifesting signs and symptoms of obstructive lung physiology .
however , patients with overlap syndrome have worse lung function , more respiratory symptoms , and a lower health - related quality of life than either disease alone [ 58 , 59 ]
. they also consume more medical resources compared to asthma or copd alone , as much as 2 to 6 times higher . from a cost perspective alone
( besides the importance of proper diagnosis and treatment ) , there is ample reason to increase our research efforts in this area . genetic linkage studies and genome - wide association ( gwa ) studies
have been of limited value in characterizing a link between asthma and copd . according to postma
et al . , the paucity of gwa studies , assessing overlap syndrome and the focus on clearly defined outcomes which do not include overlap , hampers the current insight genetic studies provide . in keeping with the dutch hypothesis , perhaps studying the genes related to airway development ( e.g. , wnt pathway ) and how these genes are altered in subjects with asthma and copd may provide clues to linkage .
one notable feature in many genetic and clinical studies is that precise definitions of asthma - copd overlap simply do not exist . in order to understand the exact nature ( genetic or otherwise ) of the asthma - copd overlap syndrome
the diseases are most different when nonsmoking asthmatics with ahr and smokers with copd but no ahr are compared .
asthmatics who smoke have more neutrophils in their airways , rather than eosinophils , resembling copd .
smoking promotes neutrophilic inflammation in both asthma and copd which results in increased steroid resistance [ 65 , 66 ] .
disease severity increases as the patterns of inflammation become more similar and steroid resistance increases .
similarly , mucosal eosinophils increase in acute exacerbations of mild copd , a feature normally seen in asthma .
this similarity in inflammatory responses may be one pathophysiologic link to the clinical phenotype of asthma - copd overlap . despite published definitions of asthma and copd by international respiratory societies such as
ats / ers and global initiatives such as gina and gold , there remains considerable clinical and pathologic overlap between these two disorders which defies such limited definitions .
elderly patients with asthma display more features of fixed obstruction than their younger counterparts , and they tend to have more severe symptoms [ 42 , 68 ] . their asthma may manifest as chronic persistent airflow obstruction mimicking copd .
ahr also increases with age where it is three times higher in the elderly compared to nonelderly adults .
age is a very important variable when assessing obstructive lung diseases given the known changes in lung function that occur with increased age and the possible role of aging genes especially in copd . because of this age effect
, appropriate comparisons between asthma and copd should be made in patient cohorts with the same or similar age , inhaled exposures , and disease severity .
indeed , increasing age may be a powerful factor blurring the line that separates asthma from copd , thus , contributing to the manifestation of overlap syndrome .
in our academic pulmonary clinics at the university of california , davis medical center ( ucdmc ) , we have observed a significant proportion of patients who present with an overlap of asthma and copd .
we defined the overlap syndrome as one of two clinical phenotypes : ( 1 ) allergic disease consistent with asthma , that is , variable airflow obstruction or ahr that is incompletely reversible ( with or without emphysema or reduced carbon monoxide diffusion capacity ( dlco ) ) or ( 2 ) copd with emphysema accompanied by reversible or partially reversible airflow obstruction ( with or without an allergic syndrome or reduced dlco ) .
patients must have demonstrated either one of these to be diagnosed with overlap syndrome .
reversible airflow obstruction is traditionally defined as an increase in fev1 or fvc by 200 ml and 12% postbronchodilator challenge , and ahr is defined by a positive methacholine challenge test . for those with clinical findings consistent with an asthma or copd diagnosis ,
asthma was defined by the gina executive summary criteria , as a clinical syndrome with
variable , airflow obstruction within the lung that is often reversible either spontaneously or with treatment .
and copd was defined by the joint ats / ers task force , as a preventable and treatable disease state characterized by airflow limitation that is not fully reversible .
we used the ats / ers recommended lower limit of the normal range for fev1/fvc ratio ( based on the 5th percentile corrected for age , gender , height , and ethnicity ) to detect abnormal expiratory airflow obstruction in order to avoid overdiagnosis of copd .
the following data do not reflect the entire patient population in our academic general pulmonary or asthma referral clinics but a smaller yet representative subset selected for analysis . in the general pulmonary clinic cohort ( figure 1 )
, the prevalence of overlap syndrome is half that of asthma ( 15.8% versus 34.2% , p = 0.014 ) and slightly over one - third that of copd / emphysema ( 15.8% versus 43.4% , p = 0.0003 ) , representing a sizable number of patients .
similarly in our severe asthma clinics ( the uc davis asthma network ( ucan ) clinics , figure 2 ) , the prevalence of overlap syndrome is approximately half that of asthma ( 24.3% versus 52.9% , p = 0.0009 ) , again representing a significant proportion of patients with mixed disease or overlap .
although asthma is the most prevalent type of airway disease ( 43.1% ) , when these data are assessed in aggregate ( figure 3 ) , the number of subjects with overlap syndrome approaches that of copd / emphysema ( 19.9% versus 23.3% , p = ns ) .
this simple observation underscores the commonplace diagnosis of overlap syndrome in subspecialist pulmonary clinics at ucdmc .
patients with asthma tend to be younger ( mean age 51.3 years old ) , those with copd or emphysema tend to be older by two decades ( mean age 72.4 years old ) , and those with overlap syndrome are in between ( mean age 66.7 years old ) .
the overlap group , however , was not significantly younger than the copd / emphysema group ( 66.7 versus 72.4 years old , p = ns ; figure 4 ) .
this is consistent with published observations that patients with overlap features tend to be older ( i.e. age 60 ) , at least as compared to patients with asthma . as the population ages , the prevalence of overlap syndrome increases in each decade ; the highest prevalence being in those > 60 years of age in our cohort ( figure 5 ) .
our observation that overlap syndrome prevalence increases with age mirrors the data reported in much larger cohorts of obstructive lung disease [ 7 , 34 ] .
these data underline the importance of this diagnosis in the elderly or aging population and the need to better distinguish amongst the various causes of chronic airflow obstruction , including overlap syndrome .
in general , the principles of workup and treatment are similar for asthma , copd , and the overlap syndrome .
because this syndrome is seen more commonly in older populations , there may be a higher probability of adverse reactions to the various classes of inhaled agents or systemic corticosteroids .
cognitive deficiencies leading to lower medication compliance may be an issue , and general underdiagnosis and undertreatment [ 42 , 73 , 74 ] may occur .
martinez et al . recommend treatment with a ics / laba combination , with or without a long - acting anticholinergic agent ( i.e. , lama ) .
smoking cessation , oxygen supplementation , pulmonary rehabilitation , and vaccines are all reasonable interventions . at present
, there are no randomized clinical trial data to help guide therapeutic interventions in overlap syndrome [ 7 , 53 ] . based on our clinical experience , we recommend a symptom - targeted approach . for dynamic obstruction and/or hyperinflation
whether lamas alone or in combination with labas are appropriate in overlap syndrome remains to be elucidated . for patients in whom bronchospasm is described and/or demonstrated , bronchodilators and icss are reasonable options .
adjunctive treatments such as leukotriene receptor antagonists , 5-lipoxygenase inhibitors , methylxanthines , or omalizumab deserve further study and should be administered by pulmonary or allergy subspecialists . as the prevalence of overlap syndrome increases with age , targeting nonrespiratory age - related changes which may influence respiratory disease is paramount .
this includes targeting nasal obstruction symptoms ( due to non - allergic or allergic rhinitis , mucosal dryness , or vasomotor symptoms ) with nasal irrigation , nasal steroids , and/or nasal anticholinergics [ 76 , 77 ] .
additionally , treating co - morbidities such has heart failure or chronic aspiration is important , especially gerd or vcd which can be subclinical .
these recommendations are based on our clinical experiences with the overlap population at ucdmc , where optimal treatment strategies still require customization and additional study .
enough evidence exists to suggest that the current definitions of asthma and copd fail to capture the diverse range of disease phenotypes .
copd , for example , is likely a heterogeneous group of diseases with different genetic backgrounds and anatomic sites of pathology , and asthma is no exception .
whether the asthma - copd overlap syndrome is a separate entity or a hybrid point within a spectrum of related diseases remains to be determined .
one certainty is that the overlap syndrome is clinically relevant with a 20% prevalence in populations with airway diseases ( similar to 15.8% in our general pulmonary clinics , see figure 1 ) .
one proposal for improved understanding is to assess similar - age patients with overlap features and well - characterized small airway involvement .
this would allow for a more homogenous group with similar sites of pathologic airway involvement that can be biopsied and correlated functionally and clinically . improved clinical data from this subpopulation of obstructive airways disease may reveal previously underappreciated pathophysiologic signatures and create an opportunity for new and targeted therapies ( figure 6 ) .
earlier screening of the overlap syndrome is important in current or former smokers in their 5th decade of life who have partially reversible airways obstruction and progressive exercise intolerance and variable ( or no response ) to guideline recommended asthma treatments .
this approach can provide more time to conduct pharmacologic and non - pharmacologic interventions before patients become elderly or develop severe disease .
future investigations should include genetic studies , assessment of aging genes expression , inflammatory profiles , exhaled nitric oxide and other biomarkers , and airway biopsies to assess immune cell profiles and airway remodeling .
these data should then be correlated to historical ( including environmental exposure and other risk factors ) , clinical , demographic , and physiological parameters .
this will help determine whether overlap syndrome is a unique phenotype of obstructive lung disease .
currently , the treatment of overlap syndrome is extrapolated from guidelines for asthma or copd .
it is unknown whether these common inhaled drugs ( ics , labas , lamas ) , oral corticosteroids , leukotriene receptor antagonists , and so forth are effective or appropriate to treat this syndrome .
therefore , future basic science studies and multicenter clinical trials should investigate disease mechanisms while developing novel therapies . by studying only those with
pure asthma or copd ( in our clinical trials ) while excluding those with overlapping features , we ignore a considerable proportion of patients with obstructive lung disease . with the aging of our population and the high prevalence and cost of overlap syndrome ,
clinical trials and further research are needed to investigate this unique population of lung disease . | ### Summary:
: many patients with breathlessness and chronic obstructive lung disease are diagnosed with either asthma , copd , or frequently mixed disease .
more commonly , patients with uncharacterized breathlessness are treated with therapies that target asthma and copd rather than one of these diseases .
this common practice represents the difficulty in distinguishing these disorders clinically , particularly in patients with a history that does not easily differentiate asthma from copd .
a common clinical scenario is an older former smoker with partially reversible or fixed airflow obstruction and evidence of atopy , demonstrating overlap features of asthma and copd .
we stress that asthma - copd overlap syndrome becomes more prevalent with advancing age as patients respond less favorably to guideline - recommended drug therapy .
we review the similarities and differences in clinical characteristics between these disorders , and their physiologic and inflammatory profiles within the context of the aging patient .
we underscore the difficulties in differentiating asthma from copd in current or former smokers , share our institutional experience with overlap syndrome , and highlight the need for new research to better characterize and investigate this important clinical phenotype . |
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: paroxysmal nocturnal haemoglobinuria ( pnh ) is an acquired stem cell disorder characterized by the clonal expansion of abnormal haematopoietic cells carrying a mutation in the phosphatidylinositol glycan class a ( pig - a ) , x - linked gene .
pnh clones fail to generate glycosylphosphatidylinositol ( gpi ) or to express a series of gpi - linked membrane proteins including complement - regulatory proteins , resulting in complement - mediated intravascular haemolysis .
the majority of cases of pnh with renal involvement reported in the literature had acute kidney injury that occurred in the setting of massive haemoglobinuria during an acute haemolytic episode .
the literature on chronic kidney disease ( ckd ) in patients with pnh is scanty , and uncertainties have existed regarding the link between renal haemosiderosis due to chronic low - grade haemolysis in pnh and chronic renal damage .
a 50-year - old normotensive and non - diabetic man of asian origin was admitted for investigation of anaemia and progressive renal impairment .
anaemia and renal dysfunction had been noticed 6 years ago ( haemoglobin 7.6 g / dl , serum creatinine 137 mol / l and creatinine clearance 52 ml / min ) during consultation at another hospital after which the patient was lost to follow - up . there were no urinary symptoms or previous history of nephrolithiasis , urinary tract infections , flank pain or dark coloured urine .
he denied taking any regular medication including non - steroidal anti - inflammatory agents . on examination
subsequent work - up confirmed intravascular haemolysis as evidenced by increased serum ldh , reduced haptoglobin and haemosiderinuria .
the direct antiglobulin ( coomb s ) test was negative implying that haemolysis was of non - immune origin .
a bone - marrow biopsy was carried out that showed marked erythroid hyperplasia , dyserythropoietic features and reduced iron stores .
diagnosis of pnh was made by the ham test indicating complement - mediated red blood cell lysis .
serum biochemistry revealed moderately severe renal impairment with a creatinine clearance of 28 ml / min/ 1.73 m. this was associated with a low - grade proteinuria of 0.68 g / day .
urine was negative for the bence - jones protein , and serum electrophoresis did not show any monoclonal band .
the predominant finding was that of widespread haemosiderosis involving the proximal tubular cells ( figure 1 ) that gave a blue tinge to the specimen on application of perls prussian blue stain .
perls prussian blue staining ( 400 ) showing haemosiderin deposits in proximal tubular cellsblue kidney .
intravascular haemolysis of a magnitude sufficient to fully saturate the binding capacity of haptoglobin leads free haemoglobin to pass through the glomerulus .
renal handling of haemoglobin is quite similar to that of glucose ; once the capacity of renal tubular cells is exceeded during a major haemolytic episode , haemoglobin appears in urine . in the tubular cells ,
some iron is re - used for the synthesis of haemoglobin , but its mobilization for this purpose is slow . when iron laden tubular cells slough into urine , both ferritin and haemosiderin may be detected in urine .
the capability of the kidney to shed and replace its iron - laden tubular cells may reduce but not always protect it against injury by siderosis .
can pnh lead to ckd ? if yes , then is ckd a direct consequence of renal haemosiderosis ? is there a true causal link between renal iron overload in pnh and ckd ? answers to these questions are not clear and have stirred a lot of controversy in the past .
reported no significant functional impairment of renal function even where renal haemosiderosis was of many years standing .
however , laboratory data pertaining to the assessment of renal function were limited in these studies ; in some cases , serum creatinine / creatinine clearance was not mentioned .
noted that many of their patients with pnh did indeed have subnormal creatinine clearances or had evidence of chronic tubular dysfunction in the chronic steady state . following this ,
a few other cases of ckd were described in patients with longstanding pnh [ 46 ] .
our case is unique in several aspects : ( 1 ) the patient had no previous admissions with haemolytic crisis / aki , but had well - documented evidence of ckd over a few years .
( 2 ) there were no other risk factors that could be implicated in ckd , i.e. no hypertension , diabetes mellitus , connective tissue disease , exposure to nephrotoxins , recurrent urinary tract infections or urinary tract obstruction .
difficulty in establishing with certainty a causal relationship between renal haemosiderosis in pnh and ckd had previously arisen from the fact that several patients had other comorbid conditions that could have contributed to renal dysfunction .
( 3 ) renal histology did not reveal any alternative cause for renal dysfunction ; the only findings were those of haemosiderosis , interstitial fibrosis and tubular atrophy .
this is in contrast to the histology findings in the cases described by kumpers et al . and
clark et al . who turned out to have features of hypertensive arterionephrosclerosis and microthrombotic infarctions , respectively .
the patient had hypertension that was not under optimal control on two anti - hypertensive agents suggesting a possible pathogenic role of hypertension in renal damage .
it would have been interesting to know if there were any hypertensive arteriolar changes on renal biopsy .
haemolytic in origin with no transfusional component as the patient had never received any blood transfusions .
the patient described by zachee et al . had received multiple blood transfusions for severe anaemia raising the possibility that transfused iron load could have contributed to renal haemosiderosis .
renal impairment associated with mesangial expansion , hypercellularity , glomerulosclerosis , interstitial fibrosis and tubular atrophy has been reported in animal models of experimental haemosiderosis as well as in patients with beta thalassaemia .
the prevailing hypothesis for chronic iron overload - induced nephrotoxicity is that of an oxidant injury to cellular membrane phospholipids by reactive oxygen species ( ros ) .
zhou et al . demonstrated that renal iron overload in experimental haemosiderosis was associated with an increase in both plasma and renal tissue malondialdehyde a lipid peroxidation product , and an increase in expression of renal endothelial and inducible nitric oxide synthase ( enos and inos ) .
iron chelation with deferoxamine in patients receiving red blood cell transfusions as supportive therapy for chronic anaemias such as beta thalassaemia , sickle cell disease and myelodysplastic syndromes attenuates organ dysfunction , strongly suggesting a pathogentic role of iron - induced ros generation .
renal tubular iron deposition resulting from chronic haemolysis is an important aetiologic factor for ckd . on the basis of clinical and histopathological findings of our case
, we feel that renal haemosiderosis can , per se , lead to ckd in patients with pnh .
future prospective studies involving a large number of patients with pnh can help establish this causal association . | ### Summary:
: a 50-year - old man presented with pancytopenia and chronic renal impairment .
he had evidence of intravascular haemolysis .
the direct antiglobulin ( coomb s ) test was negative .
paroxysmal nocturnal haemoglobinuria ( pnh ) was diagnosed by the ham acid haemolysis test .
there were no other clinical risk factors that could be implicated in chronic kidney disease ( ckd ) .
a renal biopsy revealed extensive haemosiderosis affecting proximal tubular cells and associated interstitial fibrosis as well as tubular atrophy .
no glomerular or vascular lesions were seen .
these findings strengthen the case for a causal relationship between renal haemosiderosis in pnh and ckd . |