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Biomedical subjects

S Sarkar

Publications and source records attributed to S Sarkar.

At least 397 records · Page 22Linked to original sources
PubMed1974

Constancy in human sperm DNA content.

The frequency distribution of DNA content of human sperm was measured in an automated flow microfluorometer. The flow method measures the DNA content by quantifying the amount of fluorescence emitted by the fluorescent Feulgen stained DNA of single sperm cells suspended in microdroplets. The variability in the mean value for the haploid amount of DNA in sperm from 15 randomly chosen donors was less than 1%. Statistical tests on the observed frequency distribution data indicated that each sperm population probably consists of two homogenous components present in almost equal proportions but differing in mean DNA content. The difference in their modal values for DNA is within the range of known values of DNA difference between the two sex chromosomes. Sperm of donors segregating balanced translocations, when compared to the random samples as a class, showed greater variability in the mean DNA content.

DNA↗
PubMed1971

Light chains of myosins from white, red, and cardiac muscles.

Purified preparations of rabbit skeletal white, red, and cardiac muscle myosin (WM, RM, and CM) were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Significant differences in both the molecular weights and number of light chains in these myosins were found. WM has three distinct light-chain components (LC(1W), LC(2W), LC(3W)) having molecular weights of 25,500, 17,400, and 15,100, respectively. No component with a molecular weight around 15,000 is present in RM or CM. RM and CM contain components of identical molecular weights close to 25,000 and 17,000 (LC(1CR) and LC(2CR)) which, however, clearly differ in molecular weight from the corresponding subunits in WM. RM has an additional component (LC(1R)) having a slightly higher molecular weight than LC(1W) and LC(1CR). Thus differences and similarities in many biochemical properties between WM, RM, and CM, which have been described earlier, are also reflected in the light-chain components. The present results support the hypothesis that different sets of genes are active in producing components of myosin that make up different isozymic forms characteristic of each muscle type.

Adenosine Triphosphatases↗
PubMed1970

Leukemia viruses associated with mouse myeloma cells.

Myeloma cells derived from BALB/c and C3H mice show evidence of infection by a murine leumemia virus. The immunoglobulin-producing myelomas secrete an RNA-containing virus with a density of 1.20 to 1.22 gm/cm(3). RNA with a sedimentation coefficient of 74 S in 0.1 M sodium sodium chloride has been isolated from secreted virus particles and has a base composition similar to that found for other murine leukemia virus RNA. An intracellular virus particle has been partially purified and has a density of 1.29 to 1.32 gm/cm(3). Both extracellular and intracellular virus particles contain the leukemia virus group-specific antigen.

Animals↗