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Biomedical subjects

W Braun

Publications and source records attributed to W Braun.

At least 379 records · Page 21Linked to original sources

Fluctuation tests with antibody-forming spleen cell populations.

Shortly after immunization of mice, cells forming specific antibodies to one antigen, for example, sheep red blood cells, are nonrandomly distributed throughout the spleen. If the spleen donor has been immunized with two different antigens, for example, sheep red blood cells and chicken red blood cells, the nonrandom distribution of spleen cells forming antibody to one antigen differs significantly from that of cells forming antibody to the other antigen. These findings are in accord with a clonal distribution of antibody-forming cells.

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Relation of polysaccharide content to some biological properties of endotoxins from mutants of Salmonella typhimurium.

Kessel, R. W. I. (Rutgers, The State University, New Brunswick, N.J.), Henry H. Freedman, and Werner Braun. Relation of polysaccharide content to some biological properties of endotoxins from mutants of Salmonella typhimurium. J. Bacteriol. 92:592-596. 1966.-Endotoxins were extracted by the phenol-water procedure from a variety of Salmonella typhimurium mutants with known differences in the composition of their cell wall polysaccharides. The lethality of these preparations for mice proved to be correlated with the complexity of the polysaccharide: endotoxin from the smooth parent strain and from rough strains with several sugars attached to the heptose-phosphate backbone were of high toxicity, whereas endotoxin from a mutant possessing only glucose attached to the heptose-phosphate backbone was less toxic, and endotoxin from a mutant possessing the backbone only was least toxic. All of these mutants yielded endotoxins that were equally capable of protecting mice against subsequent challenge with Pseudomonas aeruginosa. Material obtained from a heptoseless mutant by the phenol-water method proved to be neither toxic nor protective. The apparent dissociation of biological properties that can be achieved with the aid of endotoxin preparations from certain mutants is discussed in terms of possible mechanisms.

Animals↗