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Biomedical subjects

A Palit

Publications and source records attributed to A Palit.

46 records · Page 3Linked to original sources
PubMed1980

Serological and chemical interrelationship of antigens from Leptospira interrogans serovar canicola.

Antigens of the outer envelope from Leptospira interrogans serovar canicola (Hond Utrecht IV) were extracted by 50% (v/v) ethanol or by sodium dodecyl sulphate and serological analysis suggested that they were identical. The "fraction 4" extracted by alkali was found to contain glycoproteins of high (retentate) and low (filtrate) molecular weight; the latter behaved like a hapten in serology and in animal immunization experiments. Antibodies were raised in rabbits against this hapten by conjugating it to bovine albumin fraction V. The antiserum was found to react with both the low molecular weight and high molecular weight glycoproteins. This anti-hapten serum contained little or no whole-cell-agglutinating antibodies. The fraction 4 retentate behaved like a complete antigen in serological and immunization studies. Fraction 4 retentate and the outer envelope preparations were serologically related but they were not identical. Chemical studies revealed similarities between the carbohydrate component of the outer envelope obtained by ethanol extraction and fraction 4. The outer envelope extracted by ethanol, fraction 4 and its low and high molecular weight glycoproteins contained arabinose, rhamnose, fucose, xylose, mannose, galactose, glucose, glucosamine and glucuronic acid. Three unidentified peaks were observed in gas-liquid chromatographic analysis of the O-trimethylsilyl derivatives of methyl glycosides of all these samples and one of these peaks co-eluted with the O-trimethylsilyl derivative of 3-O-methylmannose.

Antigens, Bacterial↗
PubMed1977

Immunochemistry of extracts from Leptospira interrogans serotype hardjo.

Antigens from Leptospira interrogans serotype hardjo grown in modified Korthof's medium were obtained by ethanol and alkaline extraction procedures and their chemical and serological properties were compared. The protein to polysaccharide ratio in the ethanol extract was 1:1-8 and in the alkali extract was 1-7:1. The lipid content of the latter was twice that of the former (8-5%, w/w). There was an inverse relationship of the protein and carbohydrate contents of the two preparations, the total reducing sugar being higher in the ethanol extract whereas protein was higher in the alkali extract. Both preparations contained arabinose, rhamnose, fucose, xylose, mannose, galactose, glucose and galacturonic acid but in different amounts. No muramic acid or 2-keto-3-deoxyoctonate was detected. Both extracts contained erythrocyte sensitizing substances which, in the passive haemagglutination absorption test, appeared to be closely related antigenically but not identical. In the electron microscope, thin sections of the ethanol extract showed trilaminar outer envelope-like material.

Antigens, Bacterial↗
PubMed1973

Genus-specific leptospiral antigen and its possible use in laboratory diagnosis.

Sheep red cells, sensitized with a genus-specific leptospiral substance extracted from a water leptospira, were preserved by freeze drying. The serological reactivity of the preparation was tested against a total of 41 sera from proven cases of human leptospirosis and 27 from proven cases of animal leptospirosis. The sensitized, freeze-dried red cells appeared to be a sensitive reagent for the detection of leptospiral antibodies by haemagglutination. The use of this reagent as a screening test for leptospiral diagnosis is discussed. In the reported haemagglutination test on human and rabbit antisera the findings suggested that only IgM (19S) antibodies took part in the reaction.

Agglutination Tests↗