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K Sengupta

Publications and source records attributed to K Sengupta.

At least 37 records · Page 2Linked to original sources
PubMed1993

Biochemical and immunological studies on soluble antigens of Entamoeba histolytica.

The soluble antigens of Entamoeba histolytica trophozoites were analysed in detail by biochemical and immunochemical methods. The antigen was highly complex and heterogeneous as revealed by Sephacryl S-300 column chromatography, which showed four distinct fractions. The molecular mass of fractions FI, FII, FIII and FIV was 660, 170, 65 and 13 kDa, respectively. Protein was the major constituent in crude soluble antigen (CSA) and fractions FI and FII (67%, 80% and 90%, respectively). Polysaccharide was predominant in the FIII fraction (59%). Antigenic activity observed after different physico-chemical treatments revealed that CSA and FI antigens were predominantly glycoprotein in nature. However, the antigenicity of FIII antigen was greatly reduced after sodium meta-periodate treatment, whereas no alteration in reactivity was discerned after trypsin treatment. Sodium dodecyl sulphate-polyacryl-amide gel electrophoresis (SDS-PAGE) analysis demonstrated nearly 28 Coomassie blue bands for CSA and 20, 16, 15 and 3 polypeptide bands for the FI, FII, FIII and FIV fractions, respectively. The molecular mass of the polypeptides of these bands ranged from 210 to 20 kDa. Antigenic activity was observed in CSA and in the first three fractions, both in counter immunoelectrophoresis (CIEP) and in enzyme-linked immunosorbent assay (ELISA). However, the highest antigenic activity was noted in fraction FI. Major immunoreactive polypeptides of CSA and FI antigens against whole trophozoite antibody were observed in the 10- to 170-kDa regions. However, major differences in the immunoreactivity of the two antigens were noted at 116 and 14 kDa for FI antigen and at 84, 30 and 20 kDa for CSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Significance of Cryptosporidium as an aetiologic agent of acute diarrhoea in Calcutta: a hospital based study.

The significance of Cryptosporidium as a causative agent of acute diarrhoea has been assessed in a year long hospital based study. A significantly higher detection of Cryptosporidium (P < 0.01) was observed in cases as compared to controls. Cryptosporidium was detected alone from 3% of acute diarrhoeal patients and from 5.5% in combination with other enteric pathogens. However, only 1.1% of control subjects were positive for Cryptosporidium. The highest detection rate of Cryptosporidium oocysts was in the first two years of life, in both cases and controls. No sex specific predilection for Cryptosporidium was observed in either the cases or controls.

Acute Disease↗
PubMed1992

Detection of specific anti-Giardia antibodies in the serodiagnosis of symptomatic giardiasis.

The roles of circulating anti-Giardia IgM and IgG antibodies were assayed by the Enzyme linked immunosorbent assay (ELISA) using axenic Giardia lamblia whole trophozoites as antigen for routine serodiagnosis of Giardia infection. Detection of anti-Giardia IgM antibody was found to be useful in the early detection of symptomatic giardiasis, whereas IgG detection was not, since the latter could not discriminate between present infection and previous exposure. A mean optical density (OD) +/- 2 standard deviation (SD) value of 0.088 at 1:100 serum dilution was found optimal for the detection of anti-Giardia IgM antibodies as it completely separated out the acute Giardia cases from the Giardia-free controls. The same sera did not reveal any marked differences when tested for anti-Giardia IgG antibodies. Detection of IgM antibodies correlated with high sensitivity and specificity (96%) in an evaluation of a large number of sera collected from Giardia cases and controls.

Animals↗
PubMed1982

Studies on the possible mechanism of hydrazine action on ascorbic acid-metabolising enzymes.

The activities of enzymes associated with the synthesis and degradation of L-ascorbic acid were studied in hydrazine-treated rats supplemented with pyridoxine. The effects of hydrazine in vitro were also examined on these enzymes. The activity of liver D-glucuronoreductase was reduced in hydrazine-treated rats even after receiving pyridoxine in excess. But, the decreased activities of liver and kidney dehydroascorbatases in hydrazine-treated rats were reversed by pyridoxine supplementation. Hydrazine in vitro could not inhibit the activity of liver D-glucuronoreductase or L-gulonooxidase. The drug was also unable to inhibit in vitro the activity of liver and kidney dehydroascorbatases. Studies with dialyzed liver homogenates showed that the diminished activity of D-glucuronoreductase in the liver of hydrazine-treated rats was maintained even after dialyzing the tissue preparations. In contrast, the reduced activity of dehydroascorbatase in the liver of hydrazine-treated rats was abolished following dialysis of the liver preparations. It has been suggested that the diminished activity of liver D-glucuronoreductase after hydrazine treatment might arise from the reduced synthesis of enzyme protein, while the reduction in the activity of dehydroascorbatase following hydrazine treatment could be ascribed to depletion in vivo of pyridoxal phosphate and/or to the involvement of some dialyzable factors.

Animals↗
PubMed1981

Growth hormone stimulation of lipolysis and cyclic AMP levels in perifused fat cells.

A rapid, sustained lipolytic response to growth hormone (GH; 20 microgram/ml) was observed in experiments using the perifused fat cell system. No lipolytic response to this agent was observed when fat cells were incubated by the traditional flask incubation method, although isoproterenol stimulated lipolysis in this preparation. In experiments using flask incubated fat cells, isoproterenol increased cyclic AMP content while GH had no effect. However, in the presence of theophylline, isoproterenol and GH significantly increased cyclic AMP levels. In perifused fat cells, both isoproterenol and GH significantly increased cyclic AMP levels in the absence of theophylline. The presence of adenosine deaminase resulted in significant increases in the lipolytic response to isoproterenol and unmasked a lipolytic response to GH when the flask-incubated fat cell system was used. The antilipolytic action of adenosine was determined in perifused fat cells. It was found that the lipolytic response to GH was at least 10 times as sensitive to the inhibitory action of adenosine as was the lipolytic response to isoproterenol. It is concluded that the lipolytic response to GH in the flask-incubation method is prevented by the accumulation of adenosine. This rapid lipolytic response is unmasked in the perifused fat cell system because adenosine fails to accumulate as it is washed from the cell population by the constantly flowing buffer.

Adenosine↗