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Biomedical subjects

S R Bawa

Publications and source records attributed to S R Bawa.

At least 19 recordsLinked to original sources
PubMed1992

Human sperm surface mapping with lectins.

Ten fluorescein isothiocyanate (FITC)-linked lectins [Bauhimia purpurea, Concanavalin A, Dolichos biflorus (DBA), Griffonia simplicifolia I, Griffonia simplicifolia II, Maclura pomifera, Arachis hypogea (PNA), Glycine max, Ulex europaeus (UEA) and Triticum vulgaris agglutinin] have been used to study their binding features on the human ejaculate spermatozoa. Qualitative changes in the labeling pattern have been observed in unfixed and acetone-treated spermatozoa. Furthermore, ultrastructural localization of some of the colloidal gold-linked lectins, namely PNA, UEA and DBA, has been attempted to delineate the binding domains of the specific sugars on the sperm surface. It needs to be emphasized that flow-cytometric methods employed in our study, which provide quantitative slant to qualitative data, should be utilized to evaluate the functional status of the spermatozoa.

Cell Membrane↗
PubMed1988

Magnetic resonance studies of intact human spermatozoa.

A correlation has been established between the ability of sperms to reduce the nitroxide spin label--TEMPO and their metabolic activity. The rate of reduction of TEMPO is sensitive to the quantity and quality of sperms and therefore, this property can be developed into a quality rating method. Keeping this in mind, effects of various agents on the spin label reduction rates have been studied. The effect of cold shock on sperms has been found to be harmless and does not lead to loss in metabolic activity. The differential rates of spin label reduction after bubbling N2 and O2 gases through the samples indicate that the process of anaerobic glycolysis imparts higher electron donating capacity to spermatozoa. The method has been used to study influence of inhibitors of electron transport chain (ETC) such as rotenone, antimycin A, KCN and sodium azide which inhibit ETC at different levels.

Antimycin A↗
PubMed1979

Hepatic silver binding protein (Ag BP) from sparrow (Passer domesticus).

A silver binding protein (Ag BP) has been identified in the liver of sparrows administered a tracer dose of 110mAg. The protein as purified by gel-filtration shows a major absorption maximum at 260 nm and a minor one at 225 nm. It has a mol.wt of 9500 daltons and is stable when exposed to high temperature (64 degrees C for 15 min) as well as to acidic pH (2.2).

Animals↗
PubMed1977

Phase microscope study of the giant cells from the normal testes of the Indian hedgehog, Paraechinus micropus.

The phase-optic study of the germinal cells from the testes of the hedgehog, a seasonally breeding mammal, reveals the multinucleate giant cells in the natural state in late August, at the beginning of winter regression without subjecting these animals to any type of experimental stress. The participation of primary spermatocytes and spermatogonia, in addition to spermatids, in the formation of these giant cells has been observed. The nuclei at similar stage of spermatogenesis are identifiable in a single giant cell. The possible mechanism of their formation is discussed.

Animals↗
PubMed1976

Effect of gamma-irradiation on cholesterol of chicken brain.

Cholesterol in chicken brain has been determined after head irradiation with 60Co gamma rays. The brain of five-week-old white Leghorn chickens, irradiated with 1200 R showed appreciable decrease in its cholesterol content after two and five days, and a slight increase after seven days of irradiation. But the cholesterol content after seven days of irradiation was still less than the control values. However, an insignificant increase in brain cholesterol (than control) was observed after 14 days of irradiation. Nine to ten weeks old Rhode Island Red chickens exposed to 4000 R head gamma-irradiation exhibited a similar effect in cholesterol content of the brain.

Animals↗
PubMed1975

Radiation effects on rat testes. V. Studies on lysosomal enzymes (acid phosphatase and acid DNAse) and their physiological significance following partial body gamma-irradiation.

Acid phosphatase is present in the nucleus and cytoplasm of cells in the seminiferous tubules and the interstitium of rat testes. The effect of irradiation on acid phosphatase is dependent on the environmental temperature and the dose of irradiation. It appears that initial rise in the enzyme at a low radiation dose and a high environmental temperature or at a high dose and low temperature is associated with a lysosomal breakdown of the germinal cells of the testes. A decrease in acid phosphatase in the advanced stages of radiation injury is a secondary radiation effect which may lead to decreased metabolic synthesis of phosphate esters owing to the unavailability of orthophosphate in the testicular tubules. The reduced acid phosphatase activity can be detected in the seminiferous tubules, suggesting that the enzyme activity is related to the state of the germ cell population. An initial increase in acid phosphatase is matched by an initial rise in acid DNAse within hours of irradiation, further suggesting that there is radiation interaction with the cells of the germinal epithelium. The enhanced activity of DNAse following a 2nd week of irradiation at 2000 R confirms the phagocytic activity of the non-germinal cells.

Acid Phosphatase↗