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S Ghosh

Publications and source records attributed to S Ghosh.

At least 919 records · Page 51Linked to original sources
PubMed1986

Affinity binding of non-histone chromatin proteins to the X chromosome of Drosophila by in situ chromatin reconstitution and its significance.

Cytophotometric analysis of the in situ binding affinity of non-histone chromosomal protein (NHCP) to the polytenic X chromosome and autosome of Drosophila melanogaster has been carried out using Feulgen-Napthol Yellow S staining technique. The results reveal that the mean transformed absorbance ratio (male:female) with a 547 nm interference band filter for the two specific segments of the X chromosome is close to 0.5, while for a specific segment of an autosome it is close to 1.0, in the two sets of control; namely, the positive control (no treatment) and the negative control (treated with 1 M-urea+2M-NaCl) as well as in the reconstituted chromosomal preparations, which received 1 M-urea+2M-NaCl and the NHCP isolated from D. melanogaster. In contrast, the transformed absorbance ratios (male:female) with a 433 nm interference band filter yielded an interestingly different result. The ratios with a 433 nm filter for the X chromosome segments are significantly greater than 0.5 in all three sets of experiments. This finding by itself suggests that the NHCP binding affinity is dissimilar for the X chromosomes of male and female. When the 433 to 547 nm absorbance ratios were compared among the three sets, the data clearly revealed that in both positive control and NHCP reconstituted samples, the absorbance ratios (i.e. 433:547 nm) are significantly different between X chromosomes from males and those from females, while they are different between autosomes from males and females. The ratios are also not significantly different between male and female, either for the X chromosome or for the autosome in the negative control. These findings, therefore, suggest that there is a stronger binding affinity of NHCP for the male X chromosome of Drosophila, and reinstate the view that the X-chromosomal hyperactivity in male Drosophila is the consequence of a regulated organizational change in the DNA template.

Animals↗
PubMed1986

Myocardial sodium pump activity in endotoxin shock.

The effect of endotoxin administration on the integrity of sodium pump was studied in canine heart myocardium. Sodium pump activity was determined based on the 86Rb+ uptake by ventricular muscle strips. The results show that 4 hr following endotoxin administration the ouabain-sensitive 86Rb+ uptake was inhibited by 44-70%, and the inhibition was noncompetitive with 86Rb+ ions and was independent of Na+ concentrations. The sensitivity of sodium pump toward verapamil inhibition was unaffected by endotoxin administration, suggesting that the endotoxin-induced decrease in sodium pump activity is not mediated through alteration in either calcium or slow sodium channel. The sensitivity of 86Rb+ uptake to ouabain inhibition was decreased approximately sixfold in endotoxin-injected dogs. These data suggest that sodium pump is greatly impaired in dog hearts 4 hr after endotoxin administration. The impairment in sodium pump might have physiological significance in the development of myocardial dysfunction during endotoxic shock.

Animals↗
PubMed1986

Studies on interventions to prevent eltor cholera transmission in urban slums.

Transmission of eltor cholera infection in endemic communities continues without diminishing because of the absence of effective intervention measures. Two methods-chlorination of stored water and the use of a narrow-necked earthenware vessel (called a 'sorai') for storing the water-were found to be effective in reducing the transmission of infection among the family contacts of cholera patients. The cholera carrier rates in the chlorination and 'sorai' intervention groups were 7.3% and 4.4%, respectively, compared with 17.3% in the control group. The 'sorai' is cheap and was well accepted by the local communities; its narrow neck prevented the introduction of the hand and contamination of the stored water.

Adolescent↗
PubMed1986

Assay dependent specificities of monoclonal antibodies to bacterial antigens.

Six rat monoclonal antibodies, all of the IgG2b class, were generated from rats immunized with the 35A3 (Inaba) and NIH-41 (Ogawa) strain of Vibrio cholerae and selected by enzyme-linked immunosorbent assay (ELISA) on the whole organisms. When the fine specificity was dissected by several different immunological assays, the antibodies could be divided into three groups, each with a different specificity profile. Two antibodies were totally specific to the Ogawa serotype on all assays, three had a preference for Inaba but could be shown to display assay dependent cross reactions of variable intensity with Ogawa. The sixth showed total specificity for Ogawa on some assay systems, apparent total specificity for Inaba on others, and variable reaction with both serotypes on yet other assay systems. The data emphasize that it is possible to produce antibodies which do not conform to the conventional serological classification of antigens and that specificity is highly dependent on method of assessment.

Agglutination Tests↗
PubMed1986

The girl child.

Explore the source record for details and available documents.

Adolescent↗
PubMed1985

Induction of fatty acid beta-oxidation and peroxisome proliferation in the liver of rhesus monkeys by DL-040, a new hypolipidemic agent.

Many structurally unrelated hypolipidemic agents and certain phthalate-ester plasticizers induce hepatomegaly and proliferation of peroxisomes in liver parenchymal cells of rodents, but there is relatively limited evidence regarding the ability of such compounds to induce peroxisome proliferation in the livers of nonrodent species including man. The present study was designed to determine if DL-040 (4-(((1,3-benzodioxol)-5-yl)methyl)amino-benzoic acid), a newly developed hypolipidemic agent, induces peroxisome proliferation in the liver of adult rhesus monkeys. Feeding of DL-040 (300 mg/kg body wt for 1 week; and 400 mg/kg body wt for 10 weeks) caused a significant increase in peroxisome population as determined by ultrastructural and morphometric analyses. The DL-040-induced peroxisome proliferation was accompanied by increases in the levels of catalase, carnitine acetyltransferase and the peroxisomal fatty acid beta-oxidation system. As expected, DL-040 caused a significant reduction of serum cholesterol and low density lipoprotein content. These data suggest that hepatic peroxisome proliferation is inducible in nonhuman primates at dose levels that exceed therapeutic levels.

Aminobenzoates↗
PubMed1985

Purification and characterization of a guanosine diphosphatase activity from calf liver microsomal salt wash proteins.

A potent guanosine diphosphatase activity that hydrolyzes GDP to 5'-GMP + Pi has been isolated and purified from the salt wash proteins of calf liver microsomes. The purified enzyme, a monomeric protein of approximate Mr 46,000, possesses nucleotide substrate specificity since, among the nucleoside diphosphates and triphosphates tested, only GDP and UDP are hydrolyzed by the enzyme. The relative affinity of the enzyme for GDP is, however, much higher than for UDP. The effect of the enzyme on the binary complex formed between eukaryotic initiation factor 2 (eIF-2) and GDP has also been investigated. The enzyme neither hydrolyzes GDP bound to eIF-2 nor catalyzes the exchange of eIF-2-bound GDP with GTP even in the presence of Met-tRNAf. The enzyme, therefore, is presumably not involved in recycling of eIF-2 in eukaryotic polypeptide chain initiation reaction. The possible biological function of the enzyme in maintaining the cellular pool of GTP-GDP is discussed.

Animals↗
PubMed1985

Lipid keratopathy in rabbits. An animal model system.

Rabbits rendered hypercholesterolemic on a high cholesterol diet while subjected to corneal suture placement to induce neovascularization made useful models for qualitatively and quantitatively studying lipid keratopathy. Forty rabbit eyes were subjected to placement of four sutures located between 1 and 4 mm from the limbus. The neovasculature grew at a constant rate of 0.24 mm/day, unaffected by serum cholesterol levels. Rabbits fed cholesterol prior to surgery were the earliest to display lipid keratopathy, followed by those who began cholesterol feedings on the day of surgery, and last by rabbits who began receiving high cholesterol food seven days following suture placement. A description of the corneal neovascularization process and histopathological and biochemical analyses of the induced lipid keratopathy are presented.

Animals↗
PubMed1985

Electrophoretic resolution of microheterogeneity in Vibrio cholerae lipopolysaccharide.

Lipopolysaccharide (LPS) from Vibrio cholerae has been analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Under normal conditions of electrophoresis which resolve Escherichia coli LPS, V. cholerae LPS shows two diffuse and unresolved bands. However, on long gels at low concentration it can be resolved into two major band types. There are at least 10 slow moving, discrete bands of regular periodicity and three fast moving bands. Comparison with LPS from E. coli indicates that the heterogeneity occurs over a much smaller range of molecular weight in V. cholerae LPS, with the entire spectrum of discrete bands being contained within the space of four E. coli repeating units.

Electrophoresis, Polyacrylamide Gel↗
PubMed1985

Complications of therapeutic plasma exchange.

We reviewed complications associated with 1211 therapeutic plasma exchanges done on 132 patients. Complications were encountered during 148 (12%) procedures and involved 64 (48.5%) patients. Most of the complications were minor in nature but in 17 (12.9% of patients) cases the patient developed serious or potentially serious complications. In 12 cases it was serious enough to terminate the procedure. Most of the complications were due to adverse reactions to the replacement fluid. Twenty-seven (2.2%) procedures were complicated by technical problems. The relatively low rate of serious complications in our series may be due to careful observation of the patients during and after the procedure.

Adolescent↗
PubMed1985

The effect of lateral mobility on the binding and reaction rate at membrane sites.

The rates of membrane processes like transport, hormone action and enzyme reaction depend on the prevailing temperature. Arrhenius plots of such rates show a break at the phase transition temperature. We have very little insight into the molecular mechanism of the effect of phase transition on the membrane phenomena. In general above this temperature there is an onset of two dimensional mobility of the surface sites. Here, we point out that the binding of ligands to these sites should then be described by an adsorption isotherm appropriate for mobile rather than fixed sites. This introduces an additional factor in the rate equation, which correlates well with the observed changes in the rates at membrane sites on gel to liquid crystalline transition.

Enzymes↗