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Biomedical subjects

A K Chakrabarty

Publications and source records attributed to A K Chakrabarty.

At least 37 records · Page 2Linked to original sources
PubMed1981

Prevalence of food-poisoning (enterotoxigenic) Clostridium perfringens type A in blood and fish meal.

Four of 9 strains of Cl. perfringens type A isolated from 4 of 7 blood meal and 5 of 12 fish meal samples were found to be enterotoxigenic on biological tests and immunodiffusion test with enterotoxin specific serum. Enterotoxin produced by these strains was identical with that of food-poisoning strains. Of these 4 strains, 3 were heat-resistant and 1 was heat-sensitive spore formers. Rate of sporulation of enterotoxigenic strains was greater than the non-enterotoxigenic ones. Animal and public health significance of these strains were discussed.

Animal Feed↗
PubMed1979

Pathogenesis of Hobbs' heat-sensitive spore forming Clostridium perfringens type A strain.

Food poisoning in man due to heat-sensitive strains of Cl. perfringens type A appeared to be mediated through enterotoxin synthesized in vivo during sporulation. A minimum of 2.0 X 10(5) vegetative cells suspended in sporulation medium was sufficient to elicit gut-loop response in rabbits. The functional disturbance in the gut as well as the structural changes were progressive and proportional to the size of the inoculum up to a dose limit of 2.0 X 10(7) vegetative cells and beyond this the changes remained steady.

Animals↗
PubMed1979

A proposed sero-grouping scheme for epidemiological investigation of food poisoning due to Clostridium perfringens type A.

Serological studies with soluble and particulate antigens of Cl. perfringens type A revealed that enterotoxin and spore antigens could be used as a suitable marker for epidemiological studies. 94% of the food poisoning strains of Cl. perfringens type A could be grouped into 3 groups with the help of 2 enterotoxin-specific sera and 90% in 4 groups with antispore sera. Heat-sensitive strains were found to be antigenically more homogenous than the heat-resistant ones. Sera raised against spores of heat-resistant strains could not agglutinate spore of any of the heat-sensitive strains. Similarly no spores of heat-resistant strains were agglutinable by serum raised against spores of heat-sensitive strains. On the basis of typing efficiency the two antigen, viz enterotoxin and spore antigens were used in the serogrouping scheme proposed for the epidemiological investigation of food poisoning with Cl. perfringens type A. Used together, enterotoxin and spore agglutinogen form an antigenic formula for each strain showing the serogroup to which it belongs.

Agglutination Tests↗
PubMed1970

L-asparaginase-induced immunosuppression: effects on antibody-forming cells and serum titers.

Treatment of mice with L-asparaginase from Escherichia coli resulted in a marked suppression of the immune response, as assessed both cellularly and humorally. Suppression occurred only when the enzyme was injected together with the sheep erythrocytes used as antigen. There was little or no effect when the enzyme was injected before the antigen. Simultaneous injection of asparagine prevented suppression, an indication that the effect of the enzyme was due to depletion of an amino acid probably essential for normal lymphoid cell function during antibody production.

Animals↗