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Biomedical subjects

S Sarkar

Publications and source records attributed to S Sarkar.

At least 379 records · Page 21Linked to original sources
PubMed1979

Socio-economic status and prevalence of mental disorders in certain rural communities in India.

A psychiatric field-survey was conducted in three villages in West Bengal, India in order to correlate the prevalence of mental morbidity with the socio-economic status of the families. The sample was divided into four groups on the basis of religion or caste. Total morbidity had no statistically significant relationship with socio-economic status in any of the four groups. In the total sample it was directly related. Higher classes had significantly higher rates. Psychoses were not correlated with socio-economic status in any of the groups. Neuroses showed a significantly higher rate in the upper strata of two groups; in the other two groups the trend of prevalence was in the same direction. The four groups had significant differences in their rates of total morbidity. In all the groups females had a higher rate of mental morbidity. Psychoses, Neuroses and Depression were commoner in females and Schizophrenia was commoner in males.

Adolescent↗
PubMed1979

Hormone dependency of rat mammary carcinoma--a comparison of two assay systems.

Succinic dehydrogenase activity of the DMBA induced tumor explants cultured with or without hormones was assessed histochemically while receptors for estrogen (ER) and progesterone (PgR) were estimated from the cytosol fraction of the tumor tissue. Tumor regression following ovariectomy (OVX) was kept as the end point for determining hormone dependency. By in vitro method positive correlation was observed in 5 of 6 responsive or hormone dependent tumors, and 13 out of 14 independent tumors. Presence of receptors (ER + PgR, PgR) correlated with responsiveness in 4 of 6 tumors while their absence in the non-responsive group correlated in 6 of 14 tumors. Prolactin responsive tumors did not regress following OVX even if ER + PgR or ER/PgR were present. Using the same tumor tissue the results of hormone dependency by the two methods were identical in only 9 of 20 tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Translation of tobacco mosaic virus RNA In Acetabularia cell cytoplasm.

Isolated Acetabularia nuclei were microinjected with Tobacco Mosaic Virus RNA and then implanted into an anucleate posterior fragment of an Acetabularia cell. Injected RNA was translated in the Acetabularia cytoplasm from the first to twelfth day after implantation of the nuclei. The production of specific virus proteins was detected and localized in the Acetabularia cytoplasm by an immunofluorescence precipitation technique.

Acetabularia↗
PubMed1978

Population heterogeneity in human sperm DNA content.

The range of variability in the population distribution characteristics of sperm DNA content was surveyed in a selected group of donors. The donors included identical twins, carriers of chromosomal translocations, and oligospermics. The DNA content of sperm was measured individually in an automated cytofluorometer. In contrast to normal donors with high sperm counts and relatively constant modal values of sperm DNA, the balanced carriers of translocations were oligospermic and showed wide dispersion of modal values. This is an unexpected finding, since reciprocal events in the alternate form of segregation, which occurs predominantly in male carriers of balanced translocations, should not alter modal values of sperm DNA nor should they be associated with oligospermia. It appears that sperm DNA content in oligospermia, independent of its association with translocation, varies over a wide range. Thus, it is likely that genetic factor(s) unrelated to chromosome translocation control sperm DNA content.

DNA↗
PubMed1978

Patterns of lactate dehydrogenase isoenzymes during gonadogenesis in the rat.

The isoenzymes of LDH were detected by polyacrylamide gel electrophoresis. The M and H LDH subunits were present in gonads of both sexes from Day 14 1/2 p.c. and there was some variation with increased gestation. From Day 20 after birth two specific LDH-X bands (X1 and X2) were evident in the spermatocyte-rich fraction, but not in those of the Sertoli and Leydig cell fractions or those of the ovary.

Animals↗
PubMed1977

Cell antigens recognized by rabbit antibodies specific for oligomannosyl determinants.

Rabbit antibodies to cell wall mannans of various microbial strains and their mutants were found to be cross-reactive to cell carbohydrates of mammalian sperm and 4-6-days-old blastocysts. Immunochemical studies indicate that oligomers of alpha1 yields to 2, alpha1 yields to 3, alpha1 yields to 6, and probably also alpha yields to 4 linked mannose residues of sperm carbohydrates are available for antibody binding. At least 80 percent of binding activity of a yeast mannan antibody to sperm can be effectively inhibited by specific haptens or digestion with exo-alpha-D-mannosidase, an enzyme activity highest in testicular tissue. In order to determine the role of this enzyme in the metabolism of the cross-reactive mannan antigens of sperm, the relative amount of a specific alpha-linked oligomannosyl determinant of bovine sperm from homozygous normals was compared to that of hetero-zygous carriers of alpha-mannosidase deficiency. Extensive cross-reactivity between the microbial and mammalian oligomannosyl determinants suggest that these are conserved structures in cell carbohydrates, although the organization of these units in the microbial cell wall lipopolysaccharide has very little similarity to the carbohydrate moieties of mammalian glycoproteins.

Agglutination Tests↗
PubMed1977

Glucose-6-phosphate dehydrogenase (G6PD) activity of human sperm.

Sperm from normal human donors and a G6PD-A- individual were examined for x-linked glucose-6-phosphate dehydrogenase activity and autosomally linked 6-phosphogluconate dehydrogenase activity. With the use of fluorescence microscopy, we divised a procedure to visualise in individual sperm cells the fluorescence of reduced coenzyme NADPH formed by each of the two enzymes in the presence of appropriate substrates. We found significant differences in the population distribution of sperm expressing each of the two activities, and the ratio of the two activities in sperm homogenate is very different from the one found in erythrocyte lysates. The possibility of haploid gene expression has been considered in interpreting these results.

Electrophoresis, Disc↗
PubMed1976

Studies on a nonpolysomal ribonucleoprotein coding for myosin heavy chains from chick embryonic muscles.

A messenger ribonucleoprotein (mRNP) particle containing the mRNA coding for the myosin heavy chain (MHC mRNA) has been isolated from the postpolysomal fraction of homogenates of 14-day-old chick embryonic muscles. The mRNP sediments in sucrose gradient as 120 S and has a characteristic buoyant density of 1.415 g/cm3, which corresponds to an RNA:protein ratio of 1:3.8. The RNA isolated from the 120 S particle behaved like authentic MHC mRNA purified from chick embryonic muscles with respect to electrophoretic mobility and ability to program the synthesis of myosin heavy chain in a rabbit reticulocyte lysate system as judged by multi-step co-purification of the in vitro products with chick embryonic leg muscle myosin added as carrier. The RNA obtained from the 120 S particle was as effective as purified MHC mRNA in stimulating the synthesis of the complete myosin heavy chains in rabbit reticulocyte lysate under conditions where non-muscle mRNAs had no such effect. Analysis of the protein moieties of the 120 S particle by sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows the presence of seven distinct polypeptides with apparent molecular weights of 44,000, 49,000, 53,000, 81,000, 83,000, and 98,000, whereas typical ribosomal proteins are absent. These results indicate that the 120 S particles are distinct cellular entities unrelated to ribosomes or initiation complexes. The presence of muscle-specific mRNAs as cytoplasmic mRNPs suggests that these particles may be involved in translational control during myogenesis in embryonic muscles.

Animals↗
PubMed1976

A clinical evaluation of depressives found in a rural survey in India.

Those who were labelled as depressives in a rural survey were randomly divided into a Medicine group (who received antidepressive drug treatment), a Placebo group (who received placebo) and a Natural Process group (who received no treatment). The depth of their depression was assessed by Hamilton's Depressive Rating Scale before the beginning of the trial, on the 14th day and on the 28th day of trial. They were compared with a matched group of healthy controls and again with a matched group of depressives who attended an urban clinic for treatment. The results indicate that the rural depressives who never sought treatment voluntarily were not different from those who sought treatment in clinics, so far as their response to treatment is concerned.

Depression↗
PubMed1975

Cytoplasmic nonpolysomal messenger ribonucleoprotein containing actin messenger RNA in chicken embryonic muscles.

Cytoplasmic nonpolysomal mRNAs have been isolated in the form of 16-40S ribonucleoprotein particles from the postribosomal supernatant of 14-day-old chick embryonic muscles. An 8-20S RNA fraction isolated from these particles directs the synthesis of actin in a wheat germ embryo S-30 system, as judged by copurification of the products with chicken muscle actin by repeated cycles of G- to F-actin transformation; mobilities of the purified product on sodium dodecyl sulfate-polyacrylamide gels and urea gels; and analysis of the CNBr-cleaved peptides. The 16-40S particles have a buoyant density of 1.4 g/cm3 which corresponds to an RNA/protein ratio of 1:3. They do not contain detectable levels of ribosomal subunits, as judged by the absence of typical ribosomal proteins in the range of 15,000-30,000. They contain at least eight distinct polypeptide species in the molecular weight range of 44,000-100,000, including a prominent 44,000 species. The presence of these particles suggests that they may have a role in the regulation of translation in developing muscles.

Actins↗