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Biomedical subjects

S Raziuddin

Publications and source records attributed to S Raziuddin.

65 records · Page 4Linked to original sources
PubMed1980

Immunochemical studies of the lipopolysaccharides of Vibrio cholerae: constitution of O specific side chain and core polysaccharide.

Lipopolysaccharides from various strains of Vibrio cholerae have been found to consist of distinct O-specific side chain and core polysaccharide regions in their degraded polysaccharides. The major identifiable components in the core polysaccharide were phosphorus, glucose, heptose, fructose, and ethanolamine phosphate, with small amounts or traces of mannose, rhamnose, and D-perosamine. On the other hand, glucose, fructose, mannose, rhamnose, glucosamine, D-quinovosamine, and D-perosamine were identified from O-specific side chain polysaccharide. The amounts of each component have been determined from O-specific side chain and core polysaccharides of the lipopolysaccharides from these bacterial strains.

Chemical Phenomena↗
PubMed1979

Structure-function relationship: biological activities of the lipopolysaccharides and lipid A from Vibrio cholerae.

The biological activities of lipopolysaccharides and the lipid A moiety from five different strains of Vibrio cholerae have been investigated. Lipid A was biologically the most active component of lipopolysaccharides from these bacteria. Immunization of rabbits with lipid A from Inaba (66/64) strain led to the production of specific antibodies to lipid A. On fractionation of the immunoglobulins with Sephadex G-200 column chromatography, antibodies against lipid A were detected in the IgM and IgG fractions.

Animals↗
PubMed1977

Characterization of lipid A and polysaccharide moieties of the lipopolysaccharides from Vibrio cholerae.

Lipid A and polysaccharide moieties obtained by mild acid hydrolysis of the lipopolysaccharides from Vibrio cholerae 569 B (Inaba) and Vibrio el-tor (Inaba) were characterized. Heterogeneity of lipid A fractions was indicated by t.l.c. and by gel filtration of the de-O-acylated products from mild alkaline methanolysis of the lipids. Presumably lipid A contains a glucosamine backbone, and the fatty acids are probably bound to the hydroxyl and amino groups of glucosamine residues. Approximately equal amounts of fatty acids C16:0, C18:1 and 3-hydroxylauric acid were involved in ester linkages, but 3-hydroxymyristic acid was the only amide-linked fatty acid. Sephadex chromatography of the polysaccharide moiety showed the presence of a high-molecular-weight heptose-free fraction and a low-molecular-weight heptose-containing fraction. Haemagglutination-inhibition assays of these fractions showed the heptose-free fraction to be an O-specific side-chain polysaccharide, whereas the heptose-containing fraction was the core polysaccharide region of the lipopolysaccharides. Identical results were obtained for both organisms.

Chromatography, Gel↗
PubMed1976

Biochemical studies on the cell wall lipopolysaccharides (O-antigens) of Vibrio cholerae 569 B (Inaba) and El-tor (Inaba).

Lipopolysaccharides were isolated from the cell walls of Vibrio cholerae 569 B (Inaba) and El-tor (Inaba). Chemical analysis revealed the presence of glucose, fructose, mannose, heptose, rhamnose, ethanolamine, fatty acids and glucosamine. The lipopolysaccharides do not contain 2-keto-3-deoxyoctonate, the typical linking sugar of polysaccharide and lipid moieties of enterobacterial lipopolysaccharides. Galactose, a typical core polysaccharide component of many gram-negative bacteria was also absent from lipopolysaccharides of these organisms. By hydrolysis in 1% acetic acid, the lipopolysaccharides have been separated into a polysaccharide part (degraded polysaccharide) and a lipid part (lipid A). Components of degraded polysaccharide and lipid A moiety were identified and determined. The lipid A fractions contained fatty acids, phosphorus and glucosamine. All the neutral sugars detected in lipopolysaccharides were shown to be the constituents of its polysaccharide moiety. The fatty acid analysis of lipopolysaccharide and lipid A showed the presence of both hydroxy and non hydroxy acids. They were different from those of lipids extracted from cell walls before the extraction of lipopolysaccharides. 3-Hydroxylauric and 3-hydroxymyristic acids predominated in lipopolysaccharide and lipid A of Vibrio cholerae and El-tor (Inaba).

Cell Wall↗
PubMedDate not supplied

Abnormalities of CD4+ T lymphocyte proliferative responses from patients with recently diagnosed insulin-dependent diabetes mellitus.

To investigate the abnormalities of cell-mediated immunity in patients with recently diagnosed insulin-dependent diabetes mellitus (IDDM), we studied the responses of the two major T lymphocyte subsets from peripheral blood lymphocytes (PBL) to mitogen stimulation. Samples for PBL were obtained from a group of IDDM patients and from a group of normal controls. CD4+ and CD8+ T cells were isolated and were subsequently stimulated with three specific lymphocyte mitogens, namely Phytohemagglutinin (PHA), Concanavalin A (Con A) and Pokeweek mitogen (PWM). The proliferative response was measured by incorporation of radioactive thymidine in lymphocyte cultures which were stimulated by the three mitogens. The responses of CD8+ T cells from IDDM patients and from controls were not significantly different. However, CD4+ T cells from IDDM patients showed significantly depressed responses to PHA and Con A and to a much lesser extent to PWM. These data provide new information regarding the CD4+ T lymphocyte abnormalities found in patients with IDDM.

Adult↗