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<s>[INST] <<SYS>>
You are a very helpful assistant who provides accurate and concise responses.
<</SYS>>
can you explain about Intention myoclonus of multiple sclerosis, its patho-anatomical basis and its stereotactic relief.? [/INST] The typical multiple sclerosis case considered here is especially informative from both the standpoint of its clinical course and on the basis of the autopsy findings. The foci responsible for the severe bilateral intention myoclonus of the trunk and limbs are the nerve cell losses in both red nuclei due to extensive and almost complete demyelination. Thereby the triangle of Mollaret between the red nucleus, inferior olives and dentate nucleus is involved as the patho-physiological circuit responsible for myoclonus. Stereotactic coagulation of dentato-thalamic fibres resulted in complete relief of intention myoclonus. With regard to the triggering of fresh demyelinating foci by stereotactic interventions, our point of view is as follows: Although a stereotactic operation introduces the possibility of triggering new demyelinating foci in less than 10% of the cases, such a possibility does not represent an absolute contra-indication to the stereotactic treatment of action myoclonus in multiple sclerosis, if the patient is informed accordingly. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Comparison of dopa decarboxylase inhibitor (carbidopa) combined with levodopa and levodopa alone in Parkinson's disease.? [/INST] A double-blind study comparing the effects of carbidopa and levodopa combined in a single tablet with levodopa alone was undertaken in 50 patients with Parkinson's disease. After 6 months, there was a statistically significant improvement over baseline in total score, rigidity, and tremor only in the patients randomized to carbidopa/levodopa. In addition, 40 percent of the patients treated with carbidopa/levodopa showed obvious clinical improvement (a greater than 50 percent reduction in their total score) over treatment with levodopa alone. However, after 2 years, only 20 percent continued to show this improvement. Nausea, vomiting, and anorexia developed in 56 percent of patients on levodopa but in only 27 percent of patients on carbidopa/levodopa. However, abnormal involuntary movements, observed in 48 percent of patients on levodopa, were present in 77 percent of patients on carbidopa/levodopa. Despite the increase in abnormal involuntary movements, carbidopa/levodopa is more effective than levodopa. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Upper lid loading with dermis graft and levator weakening. Management of lagophthalmos due to facial palsy.? [/INST] A method to protect the cornea in case of lagophthalmos is presented, consisting in weighting the upper eyelid with dermis graft, combined with a weakening of the levator palpebrae. The technique is described, and the method is discussed versus other methods of upper lid loading. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Diagnostic importance of immunofluorescence in oral bullous diseases and lupus erythematosus.? [/INST] Immunofluorescent tests have proved to be of diagnostic importance for pemphigus, bullous pemphigoid, cicatricial pemphigoid, systemic lupus erythematosus, and discoid lupus erythematosus. Immunofluorescence test procedures, necessary specimens, and test findings have been reviewed as aids to dentists in the utilization and interpretation of these tests for the study of oral lesions. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Continued anticoagulation in oral surgery procedures.? [/INST] Anticoagulants are used in a number of clinical settings for the prevention and treatment of thromboembolic disease. The oral surgeon is seeing an increasing number of these anticoagulated patients with oral and dental disease. A technique is presented which minimizes the nonanticoagulated time for a patient requiring an oral surgical procedure. The technique requires hospitalization and should be used only for patients who are in danger of thromboembolism. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Clinical evaluation of the (+) isomer of mepivacaine.? [/INST] A human clinical study was undertaken to evaluate the effectiveness and safety of dexivacaine 2 per cent, mepivacaine 2 per cent, and mepivacaine 3 per cent. A double-blind technique was used to evaluate time of onset, duration, depth of anesthesia, and side effects. Results indicated no significant differences among the three anesthetics, except that mepivacaine 3 per cent had a significantly longer duration of soft-tissue symptoms in the mandibular block series. The few side effects noted were minimal and of no statistical significance. The evaluation of an anesthetic by the several parameters employed and especially by the over-all opinion of the anesthesia was deemed a valuable research method whem comparing the clinical effectiveness of local anesthetics. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Surgical stabilisation of the spine.? [/INST] It is important to assess spinal injuries, both in terms of cord damage and column damage, shortly after the trauma has occurred. A decision should then be made concerning the eventual stability of the bony vertebral column. If a lesion is unlikely to heal soundly by bone or if one is unable to obtain a reduction by conservative measures, one should consider surgical stabilisation of the damaged spine in the subacute phase. At the same time as one stabilISES THe spine with metallic fixation, bone grafts should be added for ultimate stability. If an unstable spine is encountered in the later stages of treatment, surgical stabilisation is again indicated. Metallic fixation can greatly aid in stabilising the spine until bone grafts can mature. Osteotomies of the spine through a combined transthoracic and posterior approach can be extremely valuable in correcting deformity. While there is no role for decompressive surgery after spinal cord injury, there is still a definite role for surgery in balancing and stabilising the vertebral column. </s> |
<s>[INST] <<SYS>>
You are a very helpful assistant who provides accurate and concise responses.
<</SYS>>
can you explain about Peripheral nervous system involvement in experimental tuberculosis.? [/INST] Following intravenous injection of mycobacteria in the mouse the bacilli are regularly found in the peripheral nervous system after the 5th day. The peripheral nerves and autonomic ganglia are involved at the level of the perineural cells and the sheath of Schwann. When the organisms are of low virulence (BCG, Mycobacterium intracellulare) the development of the nodules is limited. In the case of a virulent strain (Ravenel) extensive granulomas are found but epitheloid cells, always found in other organs, are constantly absent. In animals previously immunized, the bacilli seem to implant themselves as in the controls, but multiply more slowly; the nodules are more infrequent and the lymphoid infiltration appears earlier with the multiplication of interstitial cells. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Inhibition of HBsAg immunologic reactivity and intestinal aerobic flora.? [/INST] Cultures of human intestinal aerobic flora did not have any inhibiting action on the immunologic reactivity of hepatitis B antigen even after disruption of bacterial cells by freezing and thawing. This suggests that the inhibitor is elaborated by the human intestinal mucosa. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Management problems of mentally retarded children and their families.? [/INST] Pediatricians faced with the difficult task of providing management services to mentally retarded children and their families are confronted with a number of difficult problems. These range all the way from deciding how to inform parents that their child is retarded to dealing with grandparents who are a source of stress. Successful handling of these problems requires a recognition that management is central to the care of the mentally retarded child. The needs of mentally retarded children and their families will not be met by interacting with families only around issues of acute physical illness. Attention must be directed toward psychosocial as well as medical variables and the emphasis must be on the total family system. </s> |
<s>[INST] <<SYS>>
You are a very helpful assistant who provides accurate and concise responses.
<</SYS>>
can you explain about Common sexual problems of children and adolescents.? [/INST] The pediatrician is often expected by families to deal with sexual problems of children and adolescents. The physician should be able to identify problems and to guide parents in more meaningful communication and education of their children. Hopefully, he will be able to identify family conflicts and make the appropriate intervention or referral. He should be aware of his own sexual attitudes so as to avoid having his bias interfere with treatment. The childs behavior should not be isolated, but considered in the context of his family, his peers, and his own growth and development. Often, it is more useful to advise the family than to work with a young child. Adolescents present particular problems because of their conflicts over sexual identity, their reluctance to admit to problems, and frequently a mistrust of adults. They often feel a need for a trusting relationship with an adult, however, and are able to relate to a sensitive, non-judgmental professional. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Human figure drawing characteristics related to juvenile delinquents.? [/INST] Human figure drawings were scored on seven characteristics popularly attributed to juvenile delinquents, i.e., head size, shading, and three indicators of emotional conflict, i.e., transparencies, omissions, and erasures. Ss were adolescents incarcerated at training schools. Delinquency was defined in terms of MMPI profiles associated with delinquency rather than by social-legal or medical-diagnostic classification. The results fail to support popular hypotheses concerning human figure drawings of delinquents. Delinquents drew significantly more transparencies; however, no other emotional indicator was significant. It was concluded that little support exists for hypotheses concerning human figure drawings of delinquents and drawings should be used with caution in the clinical assessment of a delinquent's personality. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Sleep during Transcendental Meditation.? [/INST] Electroencephalograms (EEGs) and DC electrooculograms (EOGs) were recorded during Transcendental Meditation periods for 8 experienced Ss. The records, scored blind showed that all but 2 Ss spent considerable portions of their meditation periods in unambiguous physiological sleep. </s> |
<s>[INST] <<SYS>>
You are a very helpful assistant who provides accurate and concise responses.
<</SYS>>
can you explain about A new method for toilet training developmentally disabled children.? [/INST] 20 profoundly retarded children (4 to 12 yr.) were trained, using a variety of relaxation and tension activities designed to help them differentiate and gain control of the toileting musculature. Operant techniques were used to reinforce appropriate urination. The post-training scores of the experimental and control groups differed significantly for both accidental and appropriate urination. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about A chemical approach to studies of the three-dimensional structure of tRNA - alkylation with a reagent covalently bound to a "peculiar site'.? [/INST] Yeast valine tRNA1 was chemically modified with chlorambucil N-hydroxysuccinimide ester. tthe reagent was attached covalently to the valine residue of valyl-tRNA1Val under the conditions which prevented tRNA from alkylation. Chlorambucilyl-valyl-tRNA1Val thus obtained was separated from excess reagent and incubated in an aqueous solution at neutral pH in the presence of Mg++ions. Highly efficient intramolecular self-alkylation of chlorambucilyl-valyl-tRNA1Val took place. The chlorambucil residue bound covalently to the amino group of the valine residue of tRNA1Val alkylates the 5'-terminal phosphate group of the molecule, and its 3'-terminal sequence -A-C-C-A. </s> |
<s>[INST] <<SYS>>
You are a very helpful assistant who provides accurate and concise responses.
<</SYS>>
can you explain about A model for chromatin structure.? [/INST] A model for chromatin structure is presented. (a) Each of four histone species, H2A (IIbl or f2a2), H2B (IIb2 or f2b), H3 (III or f3) and H4 (IV or f2al) can form a parallel dimer. (b) These dimers can form two tetramers, (H2A)2(H2b)2 and (H3)2(H4)2. (C) These two tetramers bind a segment of DNA and condense it into a "C" segments. (d) The adjacent segments, termed extended or "E" segments, are bound by histone H1 (I or fl) for the major fraction of chromatin; the other "E" regions can be either bound by non-histone proteins or free of protein binding. (e) The binding of histones causes a structural distortion of the DNA which, depending upon the external conditions, may generate the formation of either an open structure with a heterogeneous and non-uniform supercoil or a compact structure with a string of beads. The model is supported by experimental data on histone-histone interaction, histone-DNA interaction and histone subunit-DNA interaction. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Specificity of deoxyribonucleic acid transmethylase induced by bacteriophage T2. I. Nucleotide sequences isolated from tmicrococcus luteus DNA methylated in vitro.? [/INST] (Deoxyribonucleic acid from Micrococcus luteus was methylated in vitro in the presence of S-adenosyl-(14C methyl)methionine with a DNA methyltransferase purified from extracts of te. coli infected with bacteriophage T2. The labelled DNA was degraded by enzymatic and specific chemical methods and the resulting short oligonucleotides were separated and characterized. tthe analytical data permit the conclusion that the tdna transmethylase reacts specifically with N-G-A-T-C-N sequences in which it converts adenine to a 6-methyl-aminopurine residue. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about tRNA tertiary structure in solution as probed by the photochemically induced 8-13 cross-link.? [/INST] The conformation of ten purified tRNAs from Escherichia Coli has been investigated by means of the photo-induced cross-linking of 4Srd8 and Cyd13, which is sensitive to the juxtaposition of the two bases. Three tRNAs photo-react abnormally slowly; tRNAPhe, tRNAMet/m a and tRNAVal/2; a comparison with normally reacting species suggests that base 47 (Urd or modified Urd) is involved in a tertiary interaction in Class I tRNAs with the triplet 8, 14, 28. The UGA suppressor tRNATrp photoreacts significantly slower than the wild type. Thus the single base change Gua 24 to Ade induces a conformational change that alters the rate constant for the cross-linking reaction. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Utilization of an Escherichia coli mutant for carbon-13 enrichment of tRNA for NMR studies.? [/INST] The enrichment of tRNA at specific sites with carbon-13 has been accomplished in vivo using a mutant of Escherichia coli. A relaxed strain of E. coli auxotrophic for methionine was grown in a specifically defined medium supplemented with either [14C] or [13C]-methyl labeled methionine. Cells were collected at the end of the log-phase of growth and tRNA was extracted. Analysis of the radioactivity of the [14C]-labeled tRNA established an incorporation ratio of three labeled carbons per tRNA molecule. Incorporation of the [14C]-label in vivo was confined to the methylation of nucleotides as determined by thin layer chromatography of nucleotides resulting from a ribonuclease digestion of [14C]-labeled tRNA. The carbon-13 NMR spectrum of [13C]-enriched tRNA indicated a similar degree of incorporation into the methylated nucleotides by the substantial enhancement of [13C]-methyl NMR signals only. Assignment of signals has been made for the methyl groups of ribothymidine and N7-methylguanosine in E. coli tRNA. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Misincorporation of (TP during transcription of poly dAT-dAT and poly dABU-dABU.? [/INST] The synthetic DNA alternating copolymers poly dAT-dAT and dABU-dABU have been transcribed with E. coli RNA polymerase to measure the level of BrdU-induced misincorporation of guanine during transcription. GTP is found to be misincorporated into both copolymers at a frequency of 1 per 1000-2000 nucleotides polymerized. Using alpha-32P-GTP, the nearest neighbors to GMP are found to be UMP (approximately 63%), GMP (approximately 25%) and AMP (approximately 17%), with no apparent difference between the two templates. These results suggest that BrdU-substitution in DNA does not necessarily increase the potential for base mispairing during transcription, and hence, promote the production of faulty RNA molecules. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Analysis by isopycnic centrifugation of isolated nucleoids of Escherichia coli.? [/INST] The isolated, formaldehyde-fixed nucleoid of E. coli has been analyzed by isopycnic centrifugation in CsCl density gradients. The membrane-free nucleoid bands at a density of 1.69 +/- 0.02 g/cm3. The membrane-associated nucleoid bands at a density of 1.46 +/- 0.02 g/cm3. Both species sediment to equilibrium as nearly monodisperse bands in CsCl, suggesting that the nucleoid components of DNA, RNA and protein are present in relatively constant ratios. These ratios are constant regardless of the position of the nucleoids in the heterogeneous sedimentation profile of a preparative sucrose gradient. The fixed nucleoids remain condensed during isopycnic centrifugation and there is no detectable loss of RNA from the nucleoid. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about RNA nicking activity associated with DNA ligase of T4 infected E. coli: properties and influence on in vitro reactions of ligase.? [/INST] Highly purified DNA ligase from T4 infected E. coli displays an RNA nicking activity which cleaves endonucleolytically the RNA of ribo-desoxy-and ribo-ribo type doublestranded structures to oligonucleotides with 5'phosphoryl-and 3'hydroxy termini. In the presence of ATP the generated nicks are repaired by the ligase except at the ends of the doublestranded regions where some short oligonucleotides are released before ligation can occur. As judged from its behaviour during the various purification steps and from some of its properties, the nicking activity seems to be different from known nicking enzymes. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Atomic co-ordinates for yeast phenylalanine tRNA.? [/INST] Atomic coordinates are presented for yeast tRNA(Phe) derived from a wire skeletal model fitted to an electron density map at 2.5 A resolution obtained by isomorphous replacement. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Reduction of airborne microorganisms by filtering recycled air in a chick hatcher.? [/INST] An experimental chick hatcher designed to filter recycled ventilation air was tested for its effectiveness in reducing the number of viable airborne microorganisms. Chicks in a filtered hatcher and a control hatcher (no filter) were artificially contaminated with Serratia marcescens as ventilation air was recycled in the hatchers for twelve hours. The number of viable S. marcescens particles in the filtered air of the conditioning chamber was less than detectable. The number of viable airborne S. marcescens particles in the hatching chamber of the filtered hatcher indicated a reduction of greater than 90 percent over the number in the unfiltered hatcher. The filter was effective in reducing the number of airborne particles carrying viable S. marcescens organisms in the hatcher. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effect of filtering recycled air in a chick hatcher on airborne pathogenic microorganisms.? [/INST] Two experimental chick hatchers in which ventilation air within the hatcher was partially recirculated in a positive pressure system, one with an air filter in the system and the other without a filter, were simultaneously tested to determine effect of the filter on quantitative reduction of viable airborne microorganisms. Chicks were artificially contaminated with either Escherichia coli or Staphylococcus aureus (coagulase-positive). Air was sampled for total test bacteria per cubic foot of hatcher air. The filter effectively reduced the number of viable airborne particles contaminated with E. coli and S. aureus contributed by chicks in the hatcher. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Isolation of DNA from yeast by chromatography on hydroxyapatite.? [/INST] A simple procedure is described for isolation of purified non degraded total DNA from yeast cells. The procedure involves conversion of the cells into spheroplasts by enzymatic treatment, lysis of the spheroplasts in 8 M urea - 0.24 M sodium phosphate buffer - 0.01 M EDTA (ethylendiamintetraacetic acid, sodium salt) - 1% SDS (sodium dodecyl sulphate), deproteinization of the lysate with chloroform-phenol and separation of the DNA from proteins, RNA and other contaminants by hydroxyapatite chromatography. The yield is about 90% of the DNA in the starting material (spheroplasts). </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Fragments of beta-galactosidase from Escherichia coli. Fragmentation, purification, characterization and in vitro complementation.? [/INST] Thermal fragmentation of the beta-galactosidase was studied in different buffer solutions and at different temperatures. Fragmentation of the subunits in small size polypeptides could be observed directly. The fragmentation proceeded in buffer solution, pH 7.0, at either 75 degrees C or 100 degrees C in the presence of sodium dodecyl sulfate. The elevated temperature appeared to accelerate this process. At 100 degrees C, pH 7.2, the fragmentation proceeded in the absence of sodium dodecyl sulfate, but in the presence of 8 M urea. Molecular weights, determined by sodium dodecyl sulfate disc gel electrophoresis were from 130,000 to about 20,000. Multiple bands were observed. After dissociation was complete at 37 degrees C, the fragments were purified by ion-exchange column chromatography. Of the five fragments thus obtained, four were homogeneous by disc-gel electrophoresis. Molecular weight of the homogeneous fragments were found to be near 25,000. The fifth comprised a mixture of four fragments having molecular weights from 29,000 to 72,000. Two of the fragments were active as the alpha-donor in in vitro complementation with mutant M15, which contains a deletion in the alpha-region of the z gene. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about In vivo and in vitro phosphorylation of DNA-dependent RNA polymerase of Escherichia coli by bacteriophage-T7-induced protein kinase.? [/INST] After infection with bacteriophage T7 the beta' and to a lesser extent the beta subunits of E. coli DNA-dependent RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) are phosphorylated by a phage-gene-encoded protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37). The phosphorylation occurs on threonine residues and appears site-specific. It is probably the molecular basis of the early transcriptional control. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Proton nuclear magnetic resonance of spin-labeled Escherichia coli tRNAf1MET.? [/INST] Thiouridine at position 8 (s4U8) of tRNAf1Met was spin-labeled with the nitroxide free radical, N-(1-oxyl-2,2,5,5-Tetramethyl-3-pyrrolidinyl) bromacetamide, for proton nuclear magnetic resonance spectroscopic studies. The well-resolved methyl peak of ribothymidine is unperturbed, but the peak tentatively assigned to the C-5 methylene group of dihydrouridine is considerably broadened in spin-labeled tRNAf1Met. Of the approximately 27 slowly exchanging protons observed in the region between 11 and 15 ppm downfield from 4,4-dimethyl-4-silapentane-1-sulfonic acid, the equivalent of about five protons apparently disappeared in spin-labeled tRNAf1Met. The well-resolved single proton at 14.8 ppm was missing not only in the paramagnetic species, but also in the diamagnetic reduced form of spin-labeled tRNAf1Met, and was unequivocally identified as a hydrogen bond involving s4U8 by comparison of several forms of tRNAf1Met specifically modified at s4U. Evidence that the perturbation of a second single proton resonance at 14.6 ppm (shift and broadening) is coupled to the loss of a tertiary hydrogen bond involving residue 8, arises from the same modified forms. The resolved resonances in the methyl and N-H regions, particularly the resonance at 14.6 ppm as well as the four N-bonded proton resonances at higher field which are broadened solely due to their proximity to the unpaired electron of the spin label, provide specific indicators of the geometry of tRNAf1Met structure in solution. Their observability by nuclear magnetic resonance spectroscopy opens up the possibility of monitoring distance changes among the base residues of spin-labeled tRNAf1Met upon its interaction with aminoacyl-tRNA synthetase and other enzymes. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Sulfonamide resistance mechanism in Escherichia coli: R plasmids can determine sulfonamide-resistant dihydropteroate synthases.? [/INST] Several natural isolate E. coli strains highly resistant to sulfonamides and antibiotics are shown to contain a sulfonamide-resistant dihydropteroate synthase (2-amino-4-hydroxy-6-hydroxymethyl-7,8-dihydropteridine-diphosphate:4-aminobenzoate 2-amino-4-hydroxydihydropteridine-6-methenyltransferase, EC 2.5.1.15) in addition to the normal sensitive enzyme. The resistant dihydropteroate synthases examined are determined by an R plasmid and are smaller and less heat stable than the normal sulfonamide-sensitive enzyme. One synthase resistant to any sulfonamide tested, and to sulfanilic and arsanilic acids, was still inhibited by several non-sulfonamide analogs of p-aminobenzoate. Citrobacter and Klebsiella pneumoniae strains also show similar mechanisms of sulfonamide resistance. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Release of (oligo) peptidyl-tRNA from ribosomes by erythromycin A.? [/INST] Erythromycin A released peptidyl-tRNA in the in vitro polypeptide synthesis system with bacterial components programmed by synthetic polynucleotide. This is consistent with our hypothesis that erythromycin A inhibits translocation by preventing proper situation of oligopeptidyl-tRNA in the donor (D) site on ribosomes. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Origin of hemopoietic stem cells in embryonic bursa of Fabricius and bone marrow studied through interspecific chimeras.? [/INST] The histogenesis of the bursa of Fabricius and of bone marrow was studied by a biological cell marking technique based on differences in the nuclear structure of two species of birds, Japanese quail (Coturnix coturnix japonica) and chick (Gallus gallus). In quail cells the nucleus contains a large amount of heterochromatin associated with the nucleolus. That makes it possible to distinguish them from chick cells after Feulgen-Rossenbeck staining and by electron microscopy. By grafting bursal rudiments and limb buds of quail into chick and inversely it was possible to demonstrate that the whole hemopoietic population of the bursa of Fabricius and of bone marrow is derived from bloodborne extrinsic stem cells. Neither endoderm nor mesoderm of the bursal rudiments is capable of differentiating into lymphoid cells. Combinations of quail bursal endoderm with chick homologous mesenchyme showed that the reticular cells of the follicles are the only endodermal derivatives of the bursa. The mesenchymal bursal component gives rise to the interfollicular connective cells. The contribution to bone marrow histogenesis of cells of vascular and blood origin, on one hand, and of the elements of the cartilaginous model, on the other hand, was analyzed. It appeared that osteoblasts, osteocytes, and stromal cells of marrow are derived from the perichondrium. In contrast, the endothelium of the vascular buds and the hemopoietic cells which invade the diaphysal cartilage during the endochondral ossification process do not belong to the mesenchymal bone primordium but have a fully extrinsic origin. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Conditional-lethal mutations that suppress genetic defects in morphogenesis by altering structural proteins.? [/INST] An analysis of revertants of missense mutants in phage P22 has shown: (i) New temperature-sensitive (TS) and cold-sensitive (CS) phenotypes are often acquired concomitant with reversion. (ii) In many cases, these new phenotypes are due to second-site mutations (suppressors) that correct the original defect. (iii) Sometimes the suppressor mutation is not in the same gene as the original mutation. (iv) Extragenic suppressors are almost always in genes whose products are known to interact physically with the original gene products. (v) The suppressor mutations typically retain their TS or CS phenotypes when crossed into wild-type genetic backgrounds. (vi) Some TS and CS mutants derived by reversion can themselves be reverted to produce additional mutations. We have shown that genetic reversion of missense mutants can be of value in producing new temperature-sensitive and cold-sensitive mutations affecting related functions. We suggest that our approach can be extended to organisms with large genomes. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Cluster of genes in Escherichia coli for ribosomal proteins, ribosomal RNA, and RNA polymerase subunits.? [/INST] The transducing phage lambdarifd18 isolated by Kirschbaum and Konrad [(1973 J. Bacteriol. 116, 517-526] was found to carry structural genes for several 50S ribosomal proteins and 16S and 23S rRNA. It has previously been demonstrated [Kirschbaum & Scaife (1974) Mol. Gen. Genet. 132, 193-201] that this phage carries genes for the DNA-dependent RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) subunits beta and beta'. Thus, the region of the E. coli chromosome carried by lambdarifd18 contains a cluster of genes essential for transcription and translation. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Inducible error-prone repair in Escherichia coli.? [/INST] A hypothesis that ultraviolet-induced mutagenesis arises from the induction of an error-prone mode of postreplication repair that requires the exrA+ recA+ genotype has been tested with alkaline sucrose gradient centrifugation coupled with assays of fixation determined by loss of photoreversibility. The inhibitor of protein synthesis, chloramphenicol, added before irradiation, prevented a small amount of postreplication repair and completely eliminated mutation fixation in E. coli WP2s uvrA. However, chloramphenicol did not affect strand joining: (a) in uvrA bacteria allowed 20 min of growth between irradiation and antibiotic treatment; (b) in nonmutable uvrA exrA bacteria; and (c) in uvrA tif bacteria grown at 42 degrees for 70 min before irradiation. These observations indicate that an inducible product is involved in a fraction of postreplication repair and is responsible for induced mutagenesis. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about New chromosomal location for structural genes of ribosomal proteins.? [/INST] An Escherichia coli mutant, ts9, previously reported by Flaks et al. (Cold Spring Harbor Symp. Quant. Biol. 31, 623-631, 1966) to have an electrophoretically altered ribosomal protein, has been further characterized and the altered component has been identified as L7/L12. Although mutant ts9 is temperature sensitive for growth (rts-), the rts and L7/L12 mutations are genetically separable and are both located between argH and rif. The L7/L12 mutation (rpyL) maps very close to relC, mutants of which have a defect in the 50S ribosomal subunit. The gene order is argH-rts-(rpyL,relC)-rif. Protein synthesis directed by bacteriophage lambdacI857S7drifd18 in ultraviolet-irradiated cells indicates that L7/L12, As well as L1, L10, L11, and possibly L8 or L9 are coded by the phage DNA. Our results indicate that rpyL is the structural gene for L7/L12 and that this region of the E. coli chromosome contains a cluster of structural genes for ribosomal proteins. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about A bacterial mutation blocking P2 phage late gene expression.? [/INST] A mutant of Escherichia coli strain C has been isolated, called gro109, that blocks bacteriophage P2 propagation by interfering with late gene expression. DNA replication proceeds normally in P2+-infected gro109 cells, but late phage proteins are not made. Early P2 mRNA is made in normal amounts, but very little late mRNA can be detected. P2 mutants (P2 ogr) able to overcome the gro109 block have been isolated in which synthesis of late P2 mRNA and phage proteins Is restored. The gro109 mutation is closely linked to the cluster of ribosomal genes at 64 min and is recessive to the wild-type (gro+) allele. A P2 ogr mutation has been mapped on the left arm of the P2 genome, between the right-most known late gene (D) and the phage attachment site. P2 ogr can complement P2+ in gro109 cells, indicating that ogr codes for a diffusible product. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Somnolence, akinesia, and sensory activation of motivated behavior in the lateral hypothalamic syndrome.? [/INST] After lateral hypothalamic damage in rats, somnolence, akinesia, and sensory neglect combine to produce complete aphagia. Only simple automatisms (such as grooming, chewing, licking) are present, but intense stimuli can activate more complex actions (walking, orientation, swimming). In the anorexic stage, tactile stimuli dominate in steering locomotion and "spontaneous" locomotion depends on activation from the empty stomach. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Increased glycolysis in immature rat ovaries using endogenous gonadotropins secreted in response to exogenous luteinizing hormone-releasing hormone.? [/INST] The rate of glycolysis, as indicated by in vitro lactic acid production, in ovaries from immature rats was stimulated by raising serum concentrations of endogenous LH and FSH by intravenous injections of luteinizing hormone-releasing hormone. The rate was shown to be a function of the serum concentration of gonadotropin but the response required the presence of elevated hormone levels for about 1 hr. These data are offered as further evidence for the lack of physiological importance of brief changes in pituitary function. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Analysis of PCP-data to determine the fraction of cells in the various phases of cell cycle.? [/INST] Mathematical models for the analysis of pulse-cytophotometric (PCP) data are described. With computer programs based on these models the fractions of cells in G1-, S- and (G2 + M)-phase are obtained. The methods are applied to PCP-measurements of Ehrlich ascites tumor cells, human bone marrow cells and L-929-cells in culture. The results of the L-cell experiment are compared with autoradiographic results; for both methods the duration of the various phases has been calculated. Two different mathematical models for PCP-data evaluation and the autoradiographic method yielded results agreeing within statistical error. The application of the two models on different types of DNA-histograms is discussed: One model is suitable for asynchronous cell populations with a low fraction of S-phase cells, the other can be applied for partially synchronized cells and high S-phase fractions as well. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Biological damage from the Auger effect, possible benefits.? [/INST] Decay of radioactive isotopes by K-capture leads to the Auger effect and results in the loss of several orbital electrons and the emission of X-rays. Whereas radiation effects are produced from the emitted electrons, the consequences of the Auger effect are strictly localized to the site of the decaying nuclide. The paper reviews the biological consequences of the decay of 125I which produces the Auger effect. Nearly all data were obtained from DNA labeled with 125I-5-iodo-2'-deoxyuridine (IUdR) in bacteria and mammalian cells. Parameters of effects were cell death, DNA strand breaks, and mutation induction. In order to recognize in a cell the contribution from the Auger effect and that of absorbed radiation, experimental data are analysed in terms of the specific energy for the nuclear volume which contains the isotope. The data indicate that decay of 125I is far more toxic than is expected on the basis of absorbed dose to the labeled nucleus. Moreover, it is emphasized that the toxicity of the 125I decay is largely determined by events immediately localized to the site of decay. Because the consequences of the Auger effect are stricly localized to the molecular site of the decay, 125I and perhaps other nuclides decaying by K-capture promise to be interesting tools in cell biology and molecular biology. First data on the Auger effect as a tool are summarized. It appears that recognizable biological damage is only observed when the Auger effect takes place in vitally important molecules, an example of which is DNA. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Rapid computer-aided radiographic calculation of total lung capacity (TLC).? [/INST] Methods currently used for determining total lung capacity are either simple but inaccurate in the presence of airways disease (gas dilution) or accurate but not generally available (body plethysmography). The manual radiographic method is accurate both in normals and in patients with airways disease but is very tedious to use. The authors have developed a semi-automatic radiographic method utilizing a position transducer and a small computer which reduces the time for each determination from approximately 20 min. to 1 min. Agreement with manual calculations in 80 controls and 80 patients with airways disease is excellent (average correlation coefficient, 0.9872; average residual error, 2.65% or 156 ml). </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Dynamic alveolar mechanics as studied by videomicroscopy.? [/INST] The in vivo morphology of rat alveoli has been recorded and studied on videotape. The dynamic internal structure has been compared to that observed by histologic section from lung rapidly frozen with liquid nitrogen. The irreversible nature of local alveolar wall movement has been demonstrated in animals ventilated both with and without positive end-expiratory pressure (10 cm water) by parametrically comparing the distances between two sets of paired points measured sequentially across internal alveolar surfaces at intervals of 0.017 sec. Geometric hysteresis was significantly less in the animals ventilated with positive end-expiratory pressure. This hysteresis can be explained by irreversibility in alveolar surface area apart from any irreversible dependence on surface tension. Sharp reverses and rapid changes in geometric hysteresis suggest that the length-tension properties of elastic tissue within the alveolar wall and interface forces from adjacent alveoli are important determinants of local alveolar wall motion and pulmonary hysteresis. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Comparison of five growth media and two anaerobic techniques for isolating bacteria from dental plaque.? [/INST] Five agar media in combination with the Hungate roll tube technique and conventional anaerobic jar technique (Baird & Tatlock¿ jars) were evaluated to determine the most suitable medium for non-selective isolation of the viable microorganisms in dental plaque. The highest colony count was obtained by using "Modified Medium 10" with the roll tube technique. About twice as many plaque colonies were recovered by roll tube technique as by the conventional anaerobic technique. With the MM 10 roll tube technique, 7 d of incubation revealed only 93% of the colonies that could be detected after 14 d of incubation. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effect of 2-years' use of chlorhexidine-containing dentifrices on plaque, gingivitis, and caries.? [/INST] Chlorhexidine digluconate in 0.1% and 0.4% concentrations was added to dentifrices to evaluate its effect on plaque formation, gingival conditions and caries in 73 dental students over a 2-year period. No differences were found in the Pl I and the G I indices between the active and the placebo dentifrices, but a possible effect on caries was demonstrated. Discolorations of anterior teeth and fillings were the only side effects observed. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about An inhibitor of chemotaxis and phagocytosis in reticulum cell sarcoma.? [/INST] In a study of neutrophil functions in haematological disorders using in vitro techniques, a heat-stable inhibitor of chemotaxis and phagocytosis was demonstrated in the plasma and serum of a 64-year-old woman with reticulum cell sarcoma. In partial purification by chromatography, the inhibitor activity could not be separated from IgG. Clinically the patient did not exhibit abnormal susceptibility to infections. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about In vitro inhibition of endotoxin induced platelet aggregation with hydrocortisone sodium succinate (Solu-Cortef).? [/INST] Citrated canine platelet rich plasma stimulated with ADP, thrombin, collagen and E. coli endotoxin demonstrated platelet aggregation when measured with Payton aggregometer. Following incubation with hydrocortisone sodium succinate (Solu-Cortef) the same platelet rich plasma did not undergo platelet aggregation when stimulated by these agents. Solu-Cortef added to platelet rich plasma during ATP, thrombin, collagen and endotoxin stimulated platelet aggregation resulted in a reversal of the optical density suggesting deaggregation. These in vitro observations support the beneficial effects observed when steroids are administered in vivo to experimental or clinical shock. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Complement activation in relation to protective function of antibodies to Escherichia coli O antigens.? [/INST] The relation between complement activation in an indirect hemolysis assay of E. coli O antibodies and their protective function in experimentally infected mice was analyzed. The antibody amounts and avidities were estimated in antisera and in IgG and IgM antibody fractions by the ammonium sulphate precipitation (ASP) technique of Farr. The protection obtained was due to both IgG and IgM antibodies and showed a close relation to the quantity of antibodies measured by the ASP technique. No link between complement activation capacity of the antibodies and their protective function could be seen. In the system used, the IgM antibodies showed a correlation between antibody avidity and complement activating efficiency, whereas the IgG antibodies activated complement poorly. The results do not indicate a major function of the complement in antibody-mediated protection against E. coli in this experimental system in mice. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effect of polyclonal B-cell activators on DNA synthesis in fibroblasts.? [/INST] The polyclonal B-cell activators (PBA) lipopolysaccharide (LPS), type III pneumococcal polysaccharide (SIII), dextran, dextran sulphate, pentosan sulphate, and polyvinylpyrrolidone (PVP) were found to cause an increased DNA synthesis in mouse fibroblast monolayer cultures in the presence of calf serum, provided the background cpm were within certain values. The same PBA suppressed DNA synthesis when the cultures showed high background [corrected] cpm. Since the PBA did not activate DNA synthesis in serum-free cultures, it was concluded that PBA could be directly activate fibroblasts but rather influenced factors responsible for regulation of DNA synthesis in fibroblasts. In contrast PBA directly trigger lymphocytes. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Antibody production by human colostral cells. I. Immunoglobulin class, specificity, and quantity.? [/INST] The production of antibody by human colostral cells was assayed by the hemolysis in-gel technique. When sheep erythrocytes coated with O antigens from frequently encountered Escherichia coli bacteria were used as detector cells and anti-IgA serum was added for development, numerous plaque-forming cells (PFC) were demonstrated in all samples tested. In contrast, plaques were rarely seen in the presence of anti-IgG developing serum. The direct (IgM) plaques occasionally noted with both antigen-coated and uncoated sheep erythrocytes were mainly due to the production of heterophil antibodies, since they were not formed when human erythrocytes were used as O-antigen carriers. A strikingly high number of the colostral lymphocytes formed antibodies to the E. coli antigens, up to 8%. This suggests that these cells represent a rather selective population--possibly cells from the gastrointestinal tract exposed to enteric bacteria. The large number of plaques observed, the predominance of the cells forming IgA antibodies, and the marked changes in PFC number in relationship to parturition pose a number of questions relevant to the antibody-producing colostrum cells and their relationship to the secretory immune system. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Acute epiglottitis; a clinical, bacteriological and serological study.? [/INST] 25 patients, 15 children and 10 adults, with the clinical diagnosis of acute epiglottitis were studied. Patients severely ill on admission, 13 children and 1 adult, were immediately treated with tracheotomy and antibiotics; the remaining patients with antibiotics only. Haemophilus influenzae type b was the causative organism in all children and in 3 adults. One adult had a Diplococcus pneumoniae infection. No pathogens were isolated from the 6 remaining patients. Four of the children developed H. influenzae type b meningitis. All patients recovered. Anti-b antibodies were not demonstrable in any initial serum sample while agglutinating anti-b antibodies were found in subsequent samples (indirect hemagglutination). All patients with a type b infection had already initially precipitating anti-O antibodies against their own strain, and in most cases complement-fixing anti-O antibodies (mixed H. influenzae O antigen) with rising titers in subsequent serum samples. A possible connection between the presence of anti-O antibodies initially and the development of the acute epiglottitis is discussed. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Bacteremia in a general hospital. A prospective study of 102 consecutive cases.? [/INST] A prospective clinical-bacteriological study of 102 consecutive cases of confirmed bacteremia at a Copenhagen City general hospital was carried out during 5 months of 1973 with special concern given to focus of infection and acquisition of microorganisms. Valid positive cultures were obtained from 7.2 patients per 1000 admissions. 50 of the 102 bacteremias were by all probability acquired in the hospital, mainly due to transurethral manipulations or intravenous lines. Pneumonia and hepatobiliary infections accounted for most of the non-hospital acquired bacteremias. 26/102 patients died in relation to the bacteremia. Escherichia coli and Staphylococcus aureus caused more than half of the infections. Bacteremia caused by proteus, klebsiella, enterobacter species of staphylococci was in most cases nosocomial and carried the highest mortality, i.e. 40%, verus 15% when other organisms were responsible. It is concluded that nosocomial bacteremia is a frequent and life-endangering complication which is often preceded by certain diagnostic or therapeutic procedures, not invariably linked to severe underlying diseases. Consequently, attempts to reduce bacteremic episodes should include surveillance of ecological factors and certain hospital procedures. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Comparative double-blind trial of intra-articular injections of two long-acting forms of betamethasone.? [/INST] Two injectable betamethasone preparations, betamethasone dipropionate/betamethasone phosphate and betamethasone acetate/betamethasone phosphate were compared in a controlled trial on 22 "matched patient pairs" with rheumatic diseases. The two preparations were injected intra-articularly in knee joints affected by active synovitis. The time until onset of action and the duration of clinically adequate anti-inflammatory effect were recorded. All injections produced clinically significant effects. The interval before recurrence of symptoms varied from 2 days to more than 3 months. The dipropionate form showed statistically significantly longer duration of action. No difference was noted in the time until onset of action. Local side effects were not observed. The double-blind method of clinical evaluation proved useful in comparing duration of action between long-acting corticosteroids. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Use of pectoralis skin pedicle flap for closure of large bronchial fistula connected with postpneumonectomy empyema.? [/INST] In 4 patients, the postpneumonectomy empyema was connected with a large bronchopleural fistula. The empyema was in all cases treated by a permanent open window thoracostoma. The fistulae were closed later with pedicle flaps made of the pectoralis muscle and the adjoining skin. In 2 patients the closing of the bronchial fistula was successful, and the treatment of one patient is not completed. In one patient the open pneural cavity was covered completely by skin using an additional pedicle flap and free skin transplantation. The surgical technique of the pedicle flap operation is described and the cases are reported. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Toxicity and pollution potential of thallium.? [/INST] Toxicity and pollution potential of thallium are reviewed. Thallium is slightly more acutely toxic to mammals than mercury, and as acutely toxic as copper to fish. Its present industrial uses are too limited to generate pollution, but thallium, discharged in wastes from mines, ore-processing, and coal-burning plants, is contaminating the environment. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Lymphocyte surface immunoglobulins.? [/INST] Immunoglobulins have been isolated from the surface of B (bone marrow-derived) and T (thymus-derived) lymphocytes. Two types of membrane immunoglobulin occur on B lymphocytes; one type resembles the 200,000-dalton subunit of IgM, the second possesses a heavy chain electrophoretically distinct from mu chain and does not correspond to any of the known classes of mouse immunoglobulins. It might correspond to human sigma chain. T lymphocytes possess only one type of surface immunoglobulin. This molecule has a mass of approximately 200,000 daltons and contains light chains and heavy chains similar to, but not identical to, mu chains. Evidence now exists that surface IgM-like immunoglobulins of B lymphocytes and T lymphocytes activated to certain antigens can bind specifically to antigen. These observations suggest that surface immunoglobulin functions as a receptor for antigen on B cells and at least on some T cells. The mechanisms by which combination of antigen with surface immunoglobulin initiate differentiation remain to be determined. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Implication of Phlebotomus sand flies as vectors of bartonellosis and leishmaniasis as early as 1764.? [/INST] A written account implicating Phlebotomus sand flies as vectors of Carrion's disease and cutaneous leishmaniasis in Peru was published by Cosme Bueno in 1764. Bueno's report precedes other publications implicating sand flies in the transmission of human pathogens by nearly a century and a half. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Complement-mediated bactericidal system: evidence for a new pathway of complement action.? [/INST] The early components of human complement (C1, C4, and C2) plus certain serum euglobulins will kill pathogenic strains of Shigella sonnei. Serum from patients with hereditary C3 deficiencies and specific antiserums to C3, C5, and C6 were utilized to demonstrate the absence of requirements for late-acting complement components in this unusual bactericidal system. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Anesthesia and the immune system.? [/INST] Anesthesia and operation may impair the immune system so that bacterial growth and tumor spread may occur more readily, and host response to transplanted tissue and allergenic substances may be altered. Suggestions are presented regarding the anesthetic management of patients at risk from infection or tumor spread. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effects of anesthetics on splanchnic circulation and metabolism.? [/INST] In the last 10 years intense interest in "halothane hepatitis" plus simpler and more reliable technology for measuring splanchnic blood flow have led to a fuller understanding of the splanchnic effects of anesthetics. For the first time, a rational choice of anesthetic technique can be made for the patient with splanchnic organ dysfunction. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about The biochemical basis of anesthetic toxicity.? [/INST] The inhalational anesthetics reversibly inhibit mitochondrial electron transport from NADH-linded substrates at the level of the enzyme NADH-dehydrogenase. The effect of this inhibition on ATP production is probably not the basis of the anesthetic state, as the level of high-energy phosphate in the brain does not decrease during anesthesia. Anesthetics, therefore, interfere with brain energy untilization, in addition to brain energy production. Inhibition by anesthetics of mitochondrial calcium uptake, which results from the inhibition of electron transport, may be an important anesthetic effect if it raises the intracellular calcium level. Other areas of investigation which have not been discussed here include the effects of anesthetics on glycolytic and other enzyme systems, ion fluxes, neurotransmitter synthesis and release, and on the structure of natural and artificial membranes. It is now appreciated that most of the inhalational anesthetics are metabolized by the endoplasmic reticulum of hepatocytes. The biotransformation of several anesthetics can be increased by drugs which induce hepatic microsomal enzymes. The organ toxicities of chloroform, trichloroethylene, fluroxene, methoxyflurane, and possibly of halothane and enflurane are related to their intermediary or final metabolites. It is of anesthetic drugs for an individual patient. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Anesthetic management of patients with cardiac disease.? [/INST] The course of anesthesia for patients with cardiac disease includes assessment and management of complications during the entire perioperative period. A thorough understanding of the pharmacology of anesthetic drugs and their interactions with medications taken by patients with heart disease is of utmost importance. The rapid changes in intraoperative circulatory status may often necessitate second-to-second invasive monitoring techniques to maintain stability. Finally, knowledge of complications occurring commonly in such patients allows the anesthesiologist to prepare ahead of time for corrective measures which may be lifesaving. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Deliberate hypotension.? [/INST] Deliberate hypotension can reduce major blood loss and indelicate operations can produce a drier field increasing the ease of surgery and the likelihood of a good result. The techniques used to induce hypotension can also be used to avoid dangerous hypertension during and after surgery. These benefits must be weighed against the risks of inadequate perfusion: especially cerebral, myocardial, or renal. In previously normotensive patients these risks are minimal when the arterial pressure is held above 80 torr systolic, and may be acceptably small even at mean pressure of 50 to 60 torr. Previously hypertensive patients show signs of cerebral ischemia at higher pressures; they should probably not be subjected to deliberate hypotension, but they also can be harmed by severe hypertension which can be avioded by the proper use of hypotensive agents. For most situations a balanced technique is suitable: after a stable anesthetic level has been achieved using halothane or enflurane, hypotension can be induced with sodium nitroprusside or trimethaphan camsylate. Longer-acting agents such as pentolinium are sometimes desirable, but the shorter-acting agents are easier to control. Careful monitoring with observation of intra-arterial pressure, electroencephalogram, electrocardiogram, and determination arterial blood gas tensions is likely to make for safer conduct. Close postoperative observation is essential. With careful preparation and monitoring deliberate hypotension can be a safe technique for reducing blood loss or facilitating delicate procedures. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Trace anesthetic exposure. Consequences and control.? [/INST] Epidemiologic and animal studies indicate that chronic exposure to anesthetic gases may consitute a potential health hazard. This is suggested by a higher incidence of spontaneous abortion among female operating room personnel, congenital anomalies in the offspring of operating room personnel, and neoplasia of the reticuloendothelial system. Human data show that performance can be compromised during exposure to anesthetic traces. A direct cause and effect relationship between anesthetic exposure and the alleged hazards will require further prospective studies. Such a study is being planned by the Ad Hoc Committee of the American Society of Anesthesiologists. In the interim, monitoring programs should be established to define adequate clearances of the anesthetic agents. Minimum standards and recommended procedures should be established regarding operating room ventilation and design. The use of effective scavengers and anesthetic techniques not requiring the use of inhalational agents should be encouraged. In this way a clear distinction may be defined by the prosepective study planned by the American Society of Anesthesiologists in 1978. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about The composition of massive lesions in coal miners.? [/INST] The nature of the material forming the massive lesions in the lungs of coal workers has never been demonstrated. The concept that it was in fact massive fibrosis, implying that it consisted of collagen impregnated with coal dust, has been challenged only during the last ten years. It was agreed that the best chance of obtaining more definite information was from a combined study of the biochemical, pathological, ultrastructural, and immunological features of a number of lungs containing these lesions. Six cases which were found to contain suitable material were studied. The preliminary results obtained suggest that collagen is present in the capsule of these lesions but that at the centre it is replaced by another insoluble protein or proteins which is probably stabilized by some form of cross-linking. This protein complex accounts for one-third of the weight of the lesions, the remaining two-thirds consisting of approximately equal amounts of mineral dusts and calcium phosphate. Serum proteins were also observed but their association with the lesions has yet to be determined. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Immune responses in Mycoplasma pneumoniae infections.? [/INST] All children with Mycoplasma pneumoniae infection showed a significant response in IgG immunofluorescent (IMF) antibody titers, which were similar to that of complement-fixing (CF) antibody titers. However, there was a certain degree of variation in IgM IMF antibody response and its persistence. This variation also occurred in cases with pre-existing specific antibodies and good CF and IgG IMF antibody titers. Thus, it was considered that a reinfection with M. pneumoniae might not have an important effect upon the individual variation in IgM immune response, and that after a secondary immune response with M. pneumoniae infection with specific IgM antibody could be detected in some patients. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Neutralizing antibody in Rodent Malaria.? [/INST] Small numbers of rat erythrocytes infected with viable P. berghei, when inoculated into susceptible rats together with hyperimmune rat serum (HIS), are fully neutralized. Serum from convalescent rats delays the onset of patency but does not neutralize. The neutralizing efficiency of HIS rises in proportion to the number of successive reinoculations of hyperimmune rats. In contrast, mice inoculated with parasites together with either HIS or normal rat serum succumbed to the disease at the same time after inoculation. Neutralization in rats occurs in vivo and is completed within 22 hours of inoculation. Much larger amounts of HIS are needed to achieve neutralization in splenectomized recipients than in intact rats. The action of HIS is dose-dependent. Thus, the degree of suppression of parasitaemia is proportional to the dose of HIS, while the mortality rate is inversely proportional to the dose. Suboptimal doses may even enhance the infection of recipient rats. The ability to produce neutralizing antibody is dissimilar in two strains of rat. Thus, the outbred Sabra strain produces neutralizing HIS, while the inbred Lewis rat is incapable of producing perceptible neutralizing antibody in our experimental model. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about The contribution of computerized axial tomography to the diagnosis of cerebellar and pontine hematomas.? [/INST] Case histories are reported of seven patients in whom the diagnosis of cerebellar (four) or pontine hemorrhage (three) was made by computerized axial tomography (CT). In all of the patients except two the diagnosis, established on the basis of a space-occupying high absorption lesion, was proved by either operation or autopical for an intracerebral hematoma, i.e., the high absorption zone was transformed into an area of reduced density. It is concluded that CT is a highly reliable method for the diagnosis and location of posterior fossa hematomas. A CT syndrome, observed in four of the seven cases, is described consisting of a hydrocephalus with the tips of the posterior horns being filled with blood. This seems to be specific for a posterior fossa hematoma having penetrated into the fourth ventricle. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effect of cyclandelate on dementia.? [/INST] Cyclandelate, a vasodilator, was administered to 24 patients with dementia. The dementia in these patients was presumed to be due to cerebral ischemia caused by atherosclerosis in cerebral vessels after other possible causes were ruled out. In a double-blind, cross-over study, patients received 200 mg of cyclandelate four times daily for six weeks and a placebo for six weeks. Six psychological tests, which reflect various aspects of higher cortical ability, were used to evaluate the effect of cyclandelate on the dementia. Cyclandelate was found to be no more effective than placebo in improving higher cortical function in these demented patients. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Comparison of a 9-phenanthrene methanol (WR33063), a 4-quinoline methanol (WR30090), and quinine for falciparum malaria in Thailand.? [/INST] Quinine was compared with a 9-phenanthrene methanol (WR33063) and a 4-quinoline methanol (WR30090) for the treatment of 207 patients with falciparum malaria in Southeast Thailand. Quinine eradicated parasitaemia (average 70 hours) more rapidly than either WR30090 (72 hours) or WR33063 (77 hours). But WR33063 had a higher cure rate (92%) than WR30090 (86%) or quinine (85%). The mean duration of fever and of parasitaemia were combined with the failure rate to form an arbitrary efficacy index. Using this concept WR33063 was the most effective drug. The recrudescence rate correlated with the degree and duration of parasitaemia and with the duration of fever. WR33063 was the least toxic drug. Side effects associated with WR30090 appeared to be headache, backache and urticaria. Quinine was the most toxic drug. All 3 drugs were inconvenient in having to be administered every 8 hours for 6 days. One patient did not respond to oral quinine but did respond to an intravenous quinine infusion (IVQ). A "Medication Ward Round" was perfected during the study and comprised sequential history, drug administration, physical examination, dose notation and patient observation. Falciparum nephrosis was diagnosed in one patient. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about A disquisition on suppressor T cells.? [/INST] The main points that I have put forth are that: (1) suppressor T cell activity cannot be explained as simply being too much help; (2) feedback signals from target cells are of crucial importance in determining and maintaining the activity of suppressor T cells; (3) whenever T cells are triggered by antigen, suppression occurs. Immune responses only occur when countermanding signals are also generated. Both intrinsic and extrinsic adjuvanticity is the operational production of countermanding signals; (4) memory T cells are qualitatively different from normal T cells in their sensitivity to feedback signals and also in their susceptibility to suppression; (5) mature thymus dependent B cells cannot be rendered tolerant by the direct action of antigen, while immature and thymus independent B cells can; (6) the mechanism of suppression induced by exogenously administered antigens and that by normal differentiation products (i.e.: GVH; allotypes), is different; (7) generation of suppressor cells requires or results from complex interactions between subpopulations of cells, making it impossible under present conditions to determine which cell is doing what and to which; (8) further work is required before a full understanding of the importance, mechanism of action and other aspects of suppressor T cell function can be fully understood. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about An evaluation of some factors affecting the detection of blood group antibodies by automated methods.? [/INST] Some factors affecting the sensitivity of the automated methods for blood group antibody detection have been evaluated. The experiments revealed influencing differences between various albumin preparations. In the BMC method, one lot of albumin permitted no significant antibody detection. In the LISP technique, a plateau of maximum Polybrene activity was found. The beginning of this plateau depended on both the albumin preparation and the Polybrene lot. In the BMC method, methyl cellulose gave optimal sensitivity within a concentration range of 0.3 to 0.5 per cent. The stability of test cells stored in ACD at 4 C was studied. All test cells could be used safely up to two weeks. Cells from different donors showed variable reactivity after three weeks. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Comparison of HL-A typing with NIH trays and the NIH technique with typing by the fluorochromasia cytotoxicity assay.? [/INST] A comparison of HL-A phenotypes determined with plates containing predispensed typing sera supplied by the NIH Serum Bank with phenotypes determined by the fluorochromasia cytotoxicity assay using local reagents showed that the NIH plates (as dispensed in 1972) had an insufficient number and variety of typing sera. Using NIH trays, it was difficult to detect HL-A9 and W19, both of which specificities are now known to have subtypes. The NIH trays also appeared to detect more HL-A antigens than were consistent with the current theory of two segregant series, each expressing a maximum of two antigens. The excess antigens could not be comparatively evaluated in view of the small number of sera defining each. With the NIH technique, it was impossible to interpret the reactions if the preparation had too many dead cells. A high proportion of dead cells was occasionally noted when lymphocytes had been previously frozen or obtained from lymph nodes. When the NIH and fluorochromasia techniques were compared using the same antisera and fresh lymphocytes, they proved equivalent in sensitivity. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Skin grafting across H-Y incompatibility after organ culture.? [/INST] Mouse skin maintained in organ culture for 7 days was transplanted across the H-Y histocompatibility barrier in two inbred strains: C57BL/6 and C3H/An. Cultured grafts were invariably rejected and at a faster rate than noncultured control grafts. Recipients of the cultured male skin grafts rejected subsequent noncultured male skin grafts in accelerated fashion. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about The effect of donor blood on renal allograft survival in DL-A tissue typed beagle littermates.? [/INST] A single transfusion of 200 ml of donor blood 14 days before renal transplantation in prospectively DL-A tissue typed beagle littermates appeared to have an effect on graft survival. Seventeen per cent of the recipients did respond to the transfusion with formation of lymphocytotoxic and haemagglutinating antibodies. These "responder dogs" rejected kidney grafts in an accelerated way, compared with the "nonresponders" and with the nontreated control dogs. Responsiveness appeared to occur in pairs of littermates, which suggests that responding potency is genetically determined. There was histological evidence of acute arteritis in the renal grafts of responders, whereas cell-mediated rejection was noted in nonresponders. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Inhibition of tumor growth in syngeneic chimeric mice mediated by a depletion of suppressor T cells.? [/INST] Syngeneic chimeric (lethally irradiated and reconstituted with syngeneic bone marrow cells) mice manifested an increased resistance to the development of Lewis lung carcinoma. In addition, these mice had a higher response to polyvinylpyrrolidone and a reduced reactivity to T mitogens. The present findings suggest that syngeneic chimeric mice lack suppressor T cells shown to regulate the development of Lewis lung tumor and the response to polyvinylpyrrolidone. Other components of the T cell population, such as helper cells responding to sheep red blood cells or cells involved in allograft rejection, assayed in these syngeneic chimeras were found unaffected. The fact that chimeric mice are deficient in a certain suppressor T cell population whereas other T activities are normal suggests the existence of different cell lines within the T cell population. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Effect of immunosuppressive therapy for renal allografts on the number of circulating sheep red blood cells rosetting cells.? [/INST] Patients receiving renal allografts from relatively incompatible donors were randomly assigned to one of two immunosuppressive regimens: azathioprine and prednisone with or without a 2-week course of horse antihuman thymocyte globulin (ATG). The number of circulating lymphocytes fell to about one-third of pretreatment values in both groups of patients. In patients given ATG, the proportion of sheep red blood cell-rosetting lymphocytes (SRBC-R) fell promptly to less than 10% of pretreatment values. In contrast, the percentage of SRBC-R remained at about 70% in patients receiving only prednisone and azathioprine. The addition of ATG reduced the number of SRBC-R/mm3 to one-tenth to one-thirtieth the number seen in non-ATG-treated patients. Plasma of patients undergoing therapy did not inhibit rosetting in vitro. It is proposed that the monitoring of circulating rosetting cells may be a useful clinical guide to the degree of T cell immunosuppression. It is also suggested that the regimen of azathioprine, prednisone, and ATG results in a more effective suppression of circulating T cells than that produced by azathioprine and prednisone alone. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Sex-determined antigens in rats detected by bone marrow transplantation but not skin grafting.? [/INST] Skin grafting in untreated rats and bone marrow transplantation into minimally immunosuppressed recipients have been used to investigate histocompatibility differences associated with the Y chromosome. Male skin survived for upwards of 120 days with no sign of rejection when grafted into female rats in circumstances where male bone marrow was rejected. Y chromosome-associated antigens were only detected with skin grafting by prior exposure of the female rats to male cells. It is concluded that bone marrow grafting into minimally immunosuppressed recipients may provide a more sensitive index of minor histocompatibility differences than skin grafting. The need to recognise donor cells in recipients prepared for bone marrow grafting with cytotoxic chemicals is emphasized. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Xenogeneic skin and kidney transplants in a closely related canine system, fox-dog.? [/INST] Fox kidney and skin grafts were transplanted into dog recipients. Fox kidneys, transplanted en bloc into untreated dogs, survived 6.2 +/- 0.4 days. The skin transplants survived 5.9 +/- 1.4 days. The grafted kidneys showed almost normal function before rejection. Both skin and kidney rejection were mediated through a cellular mechansim. Performed natural antibodies against donor tissue were not present in the serum of the recipients. These results combined with absorption studies suggested a close relationship between fox and dog, but different number and morphology of chromosomes, immunoelectrophoretic patterns of serum proteins, and disparities of the transplantation antigens proved that the fox is a species quite separate from the dog. It was concluded that the fox-dog system, with its similarity to the chimpanzeeman relationship, offers a unique model to study clinically applicable methods of managing xenografts between closely related species. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Attempts to compare the effectiveness of blocking factors and enhancing antibodies in vivo and in vitro.? [/INST] Sera from rats carrying tolerated skin allografts were tested for the presence of blocking activity in vitro. Sera with blocking activity had no effect on transplantation tolerance induction in newborn animals. Immunological enhancement of tumor growth was procured by passive transfer of serum from tolerant animals bearing skin allografts. It made no difference whether or not the serum contained blocking activity in vitro. These results suggest that there is no relationship between blocking factors and enhancing activity in vivo. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Quantitative colour-ultrasonography by means of a computer aided simultaneous tomogram.? [/INST] In this newly developed method, the ultrasonic diagnosis has become quantitative. The data will remain quantitative so far as an image storage tube is used. With the conventional storage type CRT, it is impossible to memorize the reflected echo signals of different strength levels. But with our method, it becomes possible to memorize the images according to individual levels. By the direct digitalization of the ultrasonic echo images, more information is obtained from the reflected echo signals. By processing the original information with a computer, more accurate diagnosis is possible. It is hoped and believed, that this computer aided ultrasonic examination, with single scan display in colour or black and white, will further promote ultrasonic diagnosis in future. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Rotational skin flaps to cover wound defect in groin.? [/INST] A technique of a lower relaxing incision and use of a rotational skin flap from the anterolateral thigh to close an extensive defect in the inguinal area is described. Its use is especially applicable for palliation in patients with large fungating metastases in the inguinal region. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about A mild method for the isolation of folded chromosomes from Escherichia coli.? [/INST] Until now it has not been possible to obtain nuclear bodies from Escherichia coli after treatment with rifampicin. It was generally assumed that the cross-connections between the DNA double strands which are sensitive towards ribonuclease are destroyed under the influence of inhibitors of RNA synthesis like rifampicin. In this paper a new lysis procedure is described for preparing nuclear bodies from E. coli. These particles differ in some respects, especially in salt sensitivity from those prepared by earlier methods. Using the new lysis method it is also possible to obtain folded chromosomes from cells after treatment with rifampicin. These nuclear bodies can be destroyed by ribonuclease. Therefore, it has to be postulated that a fraction of RNA being sufficient to hold the chromosome in the folded shape is not susceptible to the action of rifampicin. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Unfolding of the chromosome of Escherichia coli after treatment with rifampicin.? [/INST] Until recently it has been assumed that the factors being responsible for the condensation of the DNA in the nucleoid of Escherichia coli are destroyed by rifampicin because it has been impossible to obtain folded chromosomes from cells treated with this inhibitor. In this paper it is shown by viscosity and sedimentation measurements that unfolding of the DNA does not take place during the process of the cell lysis as it should be predicted from this assumption, but is occurring distinctly afterwards. Since the observed unfolding process is too slow to be caused simply by molecular movements it is concluded that it is brought about by the action of salts or detergents of the lysis medium. The structure of the nucleoid is still intact in vivo despite inhibition of RNA synthesis by rifampicin. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Rat liver alcohol dehydrogenase isozymes: influence of infection with Trypanosoma.? [/INST] A study has been made of changes in alcohol dehydrogenase (ADH) isozymes in livers of rats infected with the following trypanosomes: Trypanosoma cruzi, T. rhodesiense, T. congolense, and six geographical isolates of T. lewisi. A control group of the same age was injected with saline, and another left uninjected. Liver homogenates were electrophoresed in noble agar gels followed by formazan staining according to the method of Ursprung and Leone (1965). Of a total of 25 replicates, 15 showed that the level of rat liver ADH isozymes was similar in the uninjected and saline injected animals; 6 replicates showed a slightly higher level of ADH isozymes in uninjected than saline injected control rat livers, and 4 replicates had a higher level in saline injected than in the uninjected. With either 1-octanol or ethanol as substrate, a marked elevation of ADH activity was observed beginning with day 7 post inoculation in rat livers infected with T. cruzi, T. lewisi, and T. congolense, or as early as day 4 post inoculation with T. rhodesiense. The elevation persisted 59 days or more in rat livers infected with T. lewisi, but rats infected with the pathogenic species usually died 5 to 14 days after infection. The elevation of ADH isozymes has also been demonstrated spectrophotometrically for the first 5 minutes of reaction time, using acetaldehyde as substrate. Also observed in livers infected with pathogenic species and certain strains of T. lewisi were: (1) ADH isozyme pattern changes involving an elevated level of certain isozymes only, and (2) abnormal isozyme mobilities. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Purification and characterisation of two porcine hypothalamic fractions with LH-releasing activity: evidence for a single LH and FSH-releasing hormone.? [/INST] Two fractions with LH releasing activity were obtained from porcine hypothalami by Enzmann et al. (1972). These fractions were designated E 57 and E 203. By comparison with pure natural LH-RH and synthetic LH-RH, E 203 was identified as purified natural LH-RH. E 57, which has only 25% of the activity of E 203, was further evaluated for its biological and immunological activity. E 57 has the same ratio of LH/FSH-releasing activity as natural LH-RH. The binding to a specific LH-RH antiserum is identical with that of natural LH-RH and E 203. It is concluded, that E 57 is an artifact of isolation derived from natural LH-RH. These findings can be considered as additional evidence for the identity of the hypothalamic LH and FSH releasing hormone, since both gonadotrophins are stimulated by the two hypothalamic fractions. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Acute effects of exogenous growth hormone in man: time- and dose-bound modification of glucose tolerance and glucose-induced insulin release.? [/INST] The time and dose dependency of the effects of a 30-min long iv infusion of human growth hormone (GH) on glucose tolerance and glucose-stimulated insulin release was investigated in 19 healthy subjects. Glucose tolerance deteriorated immediately following GH, and the k-value continued to decrease up to 300 min later. A small but significant reduction of glucose tolerance persisted 24 h after GH administration. Significant deterioration of glucose tolerance was observed with the smallest GH dose used (5 mug per kg body weight), increasing the amount of the hormone having no further major influence. Glucose-stimulated insulin release was significantly inhibited 1 h after administration of a relatively high GH dose (40 mug per kg), both if expressed as mean plasma insulin levels, or as insulin release per magnitude of glucose stimulation (insulinogenic index). In the majority of subjects, insulin release was inhibited also by lower GH doses (5-20 mug GH per kg). However, the mean change with these doses was not statistically significant. The inhibitory effect of GH on insulin secretion seemed to have a duration of several hours. Five hours, but not 24 h, after GH administration (10 mug GH per kg) insulin release was still significantly suppressed. It is suggested that the initial effect of GH on pancreatic beta cells may be inhibition of insulin release, in contrast with the enhancement of insulin secretion observed during chronic administration of GH. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Radioimmunoassay of human prolactin (PRL).? [/INST] A simple and rapid homologous radioimmunoassay of human prolactin (hPRL), by the use of 66% ethanol containing 6.6% ammonium acetate for the separation of free and bound hormones, has been established. PRL levels showed marked individual and daily variations as well as a circadian periodicity in both men and women. Levels of plasma PRL rose with puberty and decreased during post-menopause and in elderly men (ages 60-73 years). There was no marked change in plasma PRL levels at midcycle; however, in some subjects, luteal levels were slightly higher than follicular levels. Administration of oestradiol-17beta caused marked increase in plasma PRL levels during menstrual cycle. During pregnancy, the plasma PRL levels rose as high as 200 ng/ml and decreased within a week or two post-partum. During lactation, the levels were higher and increased with suckling. In a patient with habitual abortion, the plasma PRL level showed a sudden drop prior to abortion. Administration of LH-RH had no effect on the secretion of PRL in human subjects. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Evaluation of impedance cardiography as a non-invasive means of measuring systolic time intervals and cardiac output.? [/INST] Impedance cardiography was used for non-invasive determinations of systolic time intervals (STI) and cardiac output. The results were compared with simultaneously obtained invasive measurements of STI from central aortic pressure curves and of cardiac output using the dye-dilution technique. The study was performed on eight dogs during increasing halothane concentration. A close correlation was found between non-invasively and invasively measured left ventricular ejection time = LVET (r = 0.986) and pre-ejection period - PEP (r - 0.948). Measurements of cardiac output derived from changes in thoracic impedance were determined 1) using a fixed value of p (p - the resistivity of blood) and 2) using an individual value of p based on the actual hematocrits. When compared to cardiac outputs obtained by dye-dilution the correlation coefficients were r = 0.806 and r = 0.816, respectively. Impedance cardiography is a useful method of evaluating changes in cardiac output. The method permits simultaneous observations of changes in STI and cardiac output as an index of cardiac function. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about A comparative study between etidocaine and bupivacaine in ulnar nerve block.? [/INST] The long-acting local anaesthetics bupivacaine and etidocaine were compared in a double-blind study using ulnar nerve block. Eleven volunteers took part in the study. Solutions used were: bupivacaine 0.25% and 0.5% and etidocaine 0.5% and 1 %. All solutions contained adrenaline 5 mug/ml. The time of onset and duration of analgesia and motor block, degree of motor block, and changes in skin temperature were investigated. The results did not show any differences in the duration of sensory of motor block. Differences were seen in the degree of motor block in favour of etidocaine. The sympathetic block seemed to be more intense and of longer duration with bupivacaine. Etidocaine had a shorter time of onset in all nerve fibres. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Axillary plexus block with etidocaine.? [/INST] Axillary plexus block has been used to compare 0.5% and 1.0% etidocaine (with adrenaline 5 mug/ml) in 32 patients in an open label study. The injected volume was 30 ml. The time to total analgesia and motor block was around 10-12 minutes. Complete block was achieved in more than 97% of cases. The duration of total analgesia and motor block was 6-7 hours. The time from injection to return of total sensation and motility was 8.5-10 hours. Adequate analgesia was achieved in all patients but two (one in each group). No noteworthy differences were found between the two solutions. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Intercostal blocks with etidocaine. Preliminary report.? [/INST] Although the results are few and should be considered as preliminary, the following conclusions may be drawn: 1. Etidocaine 0.5% and bupivacaine 0.5%, both with adrenaline (5 mug/ml), are comparable with regard to duration of sensory block. 2. Etidocaine 0.5% without adrenaline did not give the same duration of complete sensory block as when adrenaline was present. 3. Etidocaine 0.5% acts as a vasodilator at the site of injection. Adrenaline added to the solution counteracts the dilating effect. 4. Blood level studies of etidocaine do not at present show differences when 0.5% solution with or without adrenaline is used. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Virus-like particles in Creutzfeldt-Jakob biopsy material.? [/INST] In an electron microscopic study of brain biopsy material from 6 patients with Creutzfeldt-Jacob disease, virus-like particles resembling herpes have been seen. These particles were found only in reactive astrocytes. In 2 out of 6 Creutzfeldt-Jacob brain biopsies some profiles were filled with tubular structures resembling the nucleocapsid of paramyxovirus. The findings are compared with other neurological conditions. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Tissue culture study of a sacrococcygeal chordoma with further ultrastructural study.? [/INST] This report concerns an electron microscopic study of a sacrococcygeal chordoma and its in vitro cultured cells. In vitro, the cells that proliferated in the early phase were predominantly non-vacuolated stellate cells, which were later transformed into vacuolated cells. This suggests that various cell types seen in vivo represent variants of the same cell type at different stages of differentiation and cellular activity. The in vitro tumor cells also show the origin of their vacuoles from both rough endoplasmic reticulum and Golgi membranes. The finding of amorphous and granular material and collagen fibrils in the extracellular spaces of cultured cells seems to suggest that chordoma cells have certain synthetic and secretory activity. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Intravitreal injection of vancomycin in experimental staphylococcal endophthalmitis.? [/INST] Toxicity, clearance, and therapeutic effectiveness of intravitreal vancomycin hydrochloride injection in experimentally induced staphylococcal endophthalmitis were evaluated. Vancomycin was found to be nontoxic in a single, 1 mg/0.1 ml intravitreal dose. Therapeutic levels of vancomycin were present in the vitreous for over 72 hours and in the aqueous during a period from 6 to 48 hours after injection. Injection of a methicillin-resistant Staphylococcus aureus produced a panophthalmitis in our systemically treated controls, whereas in the rabbits treated by intraocular injection, the course of the infection was significantly altered. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Histocompatibility matching in poor-prognosis penetrating keratoplasty.? [/INST] Rabbits were haplotyped for the major rabbit leukocyte-locus A (RL-A locus), which is analogous to the human leukocyte-locus A (HL-A locus). The rabbits were divided into five groups, and the groups were arranged to provide a controlled experimental setting. Standardized alkali burns were induced in selected groups to produce heavy vascularization of the corneal bed. Groups with completely histocompatible corneal donors for the RL-A locus had a 9 out of 10 success rate when keratoplasty was performed on a vascularized bed. Another group of rabbits mismatched at the RL-A locus with histoincompatible corneal donors were prepared in the same manner and had a success rate of 1 out 9. A probable significant difference (P less than 0.005) using Fischer's exact test was found between the two groups. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about The pattern of new bone formation in isografts of bone.? [/INST] The pattern of new bone formation has been studied in isografts of fresh iliac bone and also in isografts of dead or irradiated iliac bone. Two phases of osteogenesis have been found in some fresh grafts. An early phase occurs during the first 3 weeks after transplantation, whilst the second phase is found after 8 weeks. The first phase is absent from non-viable grafts and it is therefore concluded that cells of the grafts are largely responsible for this early osteogenesis. The second phase, it is suggested, has a major host component, and may be due to induction of osteogenic potential in host mesenchymal cells. There may be some dependence of the second phase on the first but the extent is not clear. Removal of the bone marrow from the graft has little effect upon the first phase of new bone formation and it is suggested that surviving endosteal cells are the main participants in early osteogenesis. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about Strontium-85 profile counting in fractures of the tibial shaft.? [/INST] A total of 203 profile countings were performed on 68 fractures of the tibial shaft, which included 25 normally healing cases, 37 cases of delayed union, and six cases of non-union. The measurements were performed on the 1st and the 7th day after the injection of strontium. In 27 cases the fracture received 2-3 strontium injections with associated profile counting at different stages of the healing process. The cases of normally healing fractures and delayed union showed differences in the average strontium uptake. However, these differences were not distinct enough to enable classification of individual fractures into groups. In cases requiring bone grafting, the transplant was found to accelerate metabolism and increase the accretion of strontium at the site of the fracture. The investigation shows that the real value of strontium profile counting lies in its ability to give information about the osteogenetic activity of the bone, which is a necessary prerequisite for the healing of the fracture. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about An interactive program for the analysis of ENG tracings.? [/INST] An interactive program for clinical and research evaluation of vestibular nystagmus has been developed. Because of the interactive structure of the program, the clinician can make immediate decisions on the interpretation of controversial aspects of the nystagmogram; therefore even the more irregular and noisy ENG tracings, frequently obtained from pathological subjects, can be easily processed. In this way, speed and accuracy of computer processing are coupled with intelligent activity and critical judgement of the clinical evaluation. The program can be implemented on a general purpose minicomputer and no specific technical training is required for its use. The structure of the program and the operations performed by main subsystems are discussed in detail. Examples of ENG tracings processed with the program are reported. </s> |
<s>[INST] <<SYS>>
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<</SYS>>
can you explain about III. Evaluation of the forward triangle area in dye curves from infants and children studied by earpiece densitometry.? [/INST] Onehundred and six dye curves recorded by earpiece densitometry in shunt-free children were analysed with respect to the spatial relationships between the forward triangle and the area under the total primary dye curve. It is suggested that the relationship between these two areas, the forward triangle factor, should be 0.32 for studies in children with the use of dichromatic earpiece densitometry. </s> |