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Biomedical subjects

S K Banerjee

Publications and source records attributed to S K Banerjee.

At least 109 records · Page 6Linked to original sources
PubMed1983

DNA damage, prophage induction and mutation by furazolidone.

Ultraviolet absorption data and thermal chromatography through hydroxyapatite (HAP) column revealed that furazolidone treatment of Vibrio cholerae cells produced more than 80% of DNA reversibly bihelical due to the formation of interstrand cross-links and the reaction obeyed a first order relation. Sensitivities of the Escherichia coli strains to the lethal action of the drug were in the order: AB 2480(uvr- rec-) greater than AB 2463(rec-) greater than AB 1886(uvr-) greater than AB 1157(repair proficient) or AB 4401(wild type). Furazolidone was 'Rec test' positive, produced dose-dependent prophage induction in E. coli cells and also dose-dependent streptomycin-resistance forward mutation in V. cholerae cells. The quantitative aspect and also the mode of furazolidone action on DNA were discussed.

DNA Repair↗
PubMed1983

Killing of bacteria during solar eclipse and its biological implications.

Enhanced killing of bacteria was obtained by radiation reaching the earth during total solar eclipse (February 16, 1980) than during the corresponding time of a normal day (February 26, 1980). The killing was not due to the formation of sunlight induced photoproducts of tryptophan. The damage to the bacteria exposed to sunlight could be repaired by photoreactivation.

Escherichia coli↗
PubMed1983

Comparative studies of atrial and ventricular myosin from normal, thyrotoxic, and thyroidectomized rabbits.

Changes in enzymatic and structural properties of ventricular myosin in thyrotoxic rabbit hearts have been investigated extensively. However, there is little information regarding the effect of thyroid hormone on the atrial myosin. In this study, we have compared enzymatic and structural changes of ventricular and atrial myosin from euthyroid, hypothyroid, and hyperthyroid rabbits. In euthyroid rabbits, Ca++- and actin-activated ATPase activities of atrial myosin were 2-fold greater than those of the ventricular myosin. The Ca++- and actin-activated ATPase activities of atrial myosin from hypothyroid and hyperthyroid rabbits were identical with the values for atrial myosin from euthyroid rabbits. The same ATPase activities of ventricular myosin decreased in hypothyroid hearts but increased in hyperthyroid rabbits. The K+ (EDTA)-ATPase activities of all myosins were the same, irrespective of the thyroid status of the animal. Pyrophosphate-polyacrylamide gel electrophoresis patterns showed two isoenzymes (designated as A1 and A3) of atrial myosin in euthyroid hearts. The same electrophoretic patterns also showed in atrial myosin from hypothyroid and hyperthyroid hearts. The ventricular myosin from euthyroid hearts also exhibited two isoenzymes (designated as V1 and V3) but each with slower electrophoretic mobilities than the corresponding atrial myosin. In hypothyroid hearts, only V3 isoenzyme was seen, whereas, in hyperthyroid hearts, only V1 isoenzyme was seen. These results suggest that thyroid hormone controls ventricular myosin ATPase activity by controlling synthesis of a specific ventricular isoenzyme, whereas thyroid hormone does not affect atrial myosin ATPase, possibly due to its inability to control atrial myosin synthesis.

Actins↗
PubMed1982

Effects of removal of light chain 2 on the ATPase activities of cardiac myosin from normal and thyrotoxic rabbits.

Steady-state ATPase activities of cardiac myosin from thyroxine-treated rabbit hearts have been determined before and after removal of the 18-kDa light-chain subunit (LC2) of myosin. LC2 was selectively removed from myosin by treatment with a myofibrillar protease according to the method of Kuo and Bhan (Biochem. Biophys. Res. Commun. 92, 570-576 (1980) ). The effects of removal of LC2 on the enzymatic properties of thyrotoxic myosin were compared with the results obtained for cardiac myosin from normal rabbits by parallel studies. It has been found that removal of LC2 does not affect the Ca2+- and K+ (EDTA)-ATPase activities of these myosins. The actin-activated myosin Mg2+-ATPase activities of intact and LC2-deficient thyrotoxic myosin were 0.18 +/- 0.03 and 0.36 +/- 0.03 mumol Pi/mg per min, respectively, whereas the actin-activated myosin Mg2+-ATPase activities of intact and LC2-deficient normal myosin were 0.12 +/- 0.02 and 0.18 +/- 0.03 mumol Pi/mg per min, respectively. Thus, removal of LC2 increases the actin-activated myosin Mg2+-ATPase activity of thyrotoxic myosin by 100%, and the same activity is increased about 50% for normal myosin, indicating that the degree of potentiation of actin-activated myosin Mg2+-ATPase activity as a result of LC2 removal is 2-fold greater in thyrotoxic myosin than that obtained for normal myosin. These results suggest that LC2 does not influence the increased actomyosin ATPase activity of thyrotoxic myosin and that potentiation of actomyosin ATPase following LC2 removal may depend on the variations of the heavy-chain domain where LC2 interacts.

Actins↗
PubMed1981

Radiomimetic property of furazolidone and the caffeine enhancement of its lethal action on the vibrios.

Sensitivities of the strains belonging to four vibrio biotypes to the action of furazolidone were investigated. Vibrio cholerae (classical) was most and Vibrio parahaemolyticus least sensitive to this drug. Statistical analyses revealed significant differences between any two of the four types of vibrio in respect of their sensitivity to furazolidone. The drug was radiomimetic in action, the doses of UV light (DUV) and furazolidone (Df) required for 10% survival of the vibrios being correlated by the equation, Df = 0.28 exp. (0.008 DUV). Caffeine exhibited lethal synergism with furazolidone and the synergistic effect depended on the mode of caffeine treatment, the effect being maximum when caffeine was present along with and also after furazolidone treatment. UV spectrophotometric study revealed that caffeine did not bind with native DNA but did so with denatured DNA resulting in a bathochromic shift and a quenching of the caffeine absorption maximum at 209.4 nm. The binding isotherm (Scatchard plot) indicated the presence of a heterogeneity in the binding sites and that the parameters for the strongest mode of bonding were n = 0.254 and k = 7.5 X 10(5) M-1.

Caffeine↗
PubMed1981

Studies on the protective effects of L-ascorbic acid in chronic chlordane toxicity.

The influence of extraneous supplementation of L-ascorbic acid in chronic chlordane toxicity has been studied in rats. Oral administration of chlordane brings about a marked growth retardative effect, stimulates vitamin C synthesis in the system, elevates the vitamin C status of the liver and kidney tissues and also the urinary excretion. It inhibits the activities of acid and alkaline phosphatases, SDH and Mg2+-ATPase of both hepatic and renal tissues. The activities of serum and mitochondrial GOT, serum alkaline phosphatase, and glucose-6-phosphatase of both hepatic and renal tissues are markedly stimulated. The normal histological patterns of both liver and kidney tissues are grossly altered under chlordane toxicity condition. There occurs marked increase in the hepatic lipid composition. Supplementation of L-ascorbic acid in high doses to the chlordane treated rats can effectively counteract some of these alterations in respect of enzyme activities, morphological characteristics and of hepatic lipid composition.

Animals↗
PubMed1979

Phenylglyoxal modification of cardiac myosin S-1. Evidence for essential arginine residues at the active site.

The role of arginine residues in the catalytic activity of cardiac myosin subfragment-1 (S-1) was investigated by selective modification with phenylglyoxal. Incorporation of about 2.8 mol of phenylglyoxal/mol of S-1 decreased Ca2+-ATPase activity about 50%. Gelation of the protein occurred at about 70% inactivation; however, extrapolation to complete inactivation indicated that loss of activity correlated with modification of about 4 arginyls/mol. Partial inactivation of S-1 with phenylglyoxal also decreased MgADP binding markedly. When S-1 was modified in the presence of 5 mM MgADP, only 2 arginyls/mol were blocked and there was almost complete protection against loss of Ca2+-ATPase activity and ability to bind MgADP. Similar protection against inactivation by phenylglyoxal was obtained with MgATP or sodium pyrophosphate, but not with MgAMP or magnesium adenosine. These results suggest that 2 arginyls/myosin head are important for enzymatic activity, possibly serving as attachment points between enzyme and substrate. These essential arginyls were localized to a 17,000-dalton cyanogen bromide peptide from the heavy chain fragment of S-1.

Aldehydes↗
PubMed1978

Some aspects of internal annual migration in India.

Data collected in 1973-1974 during the twenty-eighth round of the National Sample Survey are used to analyze annual internal migration in India. "The analysis reveals that [the in-migration] rate for all-India was estimated at 91 for the rural and 104 for the urban areas per 10,000 population. Out of the total migration intra-state migration was as high as 87 percent and more than 68 percent came from rural areas. The most important flow of migration was rural to rural and next to that was urban to urban followed by rural to urban and urban to rural." Findings are also presented concerning variations among states, rates of urbanization, the age and sex composition of migrants, reasons for migration, the educational level of labor migrants, and changes since the 1963-1964 round of the survey.

Age Distribution↗