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Biomedical subjects

B Prescott

Publications and source records attributed to B Prescott.

124 records · Page 7Linked to original sources
PubMed1966

Isolation and characterization of fractions of Mycoplasma pneumoniae. I. Chemical and chromatographic separation.

Prescott, B. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), O. Sobeslavsky, G. Caldes, and R. M. Chanock. Isolation and characterization of fractions of Mycoplasma pneumoniae. I. Chemical and chromatographic separation. J. Bacteriol. 91:2117-2125. 1966.-Fractionation of Mycoplasma pneumoniae, cultured on a beef heart infusion-horse serum-yeast extract medium, was carried out by chemical and chromatographic procedures. The chemical method yielded eight fractions consisting of lipid, carbohydrates, and proteins. Four protein-rich fractions were isolated by chromatographing a supernatant fluid of sonically treated organisms on Sephadex G-25. The 12 fractions were tested for serological and antigenic activity in vitro and in vivo. The lipid fraction was serologically active and the relative order of activity of the protein fractions appeared to depend on the amount of lipid present in the molecule. The highly serologically active Sephadex G-25 protein fraction 1 prepared chromatographically contained 15% lipid in the molecule, whereas the less serologically active protein fraction 2 prepared by chemical means contained 2% lipid. The acetone-extracted lipid fraction was chromatographed on thin-layer chromatography plates and found to consist of nine fractions. Serological activity was associated with only the first three spots above the origin. Lipid extracted from the protein fractions seemed to be similar to the acetone-extracted lipid from the sediment of the sonically treated organisms.

Amino Acids↗
PubMed1966

Isolation and characterization of fractions of Mycoplasma pneumoniae. II. Antigenicity and immunogenicity.

Sobeslavsky, O. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), B. Prescott, W. D. James, and R. M. Chanock. Isolation and characterization of fractions of Mycoplasma pneumoniae. II. Antigenicity and immunogenicity. J. Bacteriol. 91:2126-2138. 1966.-Chemical and chromatographic fractions of disrupted Mycoplasma pneumoniae organisms were examined for serological and immunogenic activity. Complement-fixing activity was associated with lipid components, whereas precipitin activity was chiefly associated with polysaccharide components. When chemically extracted lipids were separated by thin-layer silica gel chromatography, only three of the nine fractions exhibited complement-fixing activity. Although lipids were highly active serologically, they were only weakly immunogenic. However, lipids combined with protein in lipoprotein complexes were highly immunogenic, stimulating high levels of complement-fixing, indirect-hemagglutinating, and growth-inhibiting antibodies. The specificity of these antibodies was directed chiefly against the serologically active lipid constituents of the organism. It was suggested that these serologically active lipids are present at the sites on the limiting membrane of M. pneumoniae at which antibody acts to inhibit growth of the organism. Only protein fractions adsorbed to tanned erythrocytes. The main function of protein in the indirect-hemagglutination reaction appeared to be that of serving as a carrier for the serologically active lipids.

Animals↗
PubMedDate not supplied

Regulation of the antibody response to pneumococcal polysaccharide by thymus-derived cells.

The dose-response relationships in mice immunized with capsular polysaccharide of type 3 Streptococcus pneumoniae (SSS-III) show a distinctive pattern characterized by a single optimal dose for immunization within a relatively narrow range of immunizing doses. Most of the antibody produced is of the IgM class, and the kinetics for the development of both the cellular and serum antibody response to this antigen are parallel up to the peak of the immune response. Although thymus-derived (T) cells are not needed to initiate an antibody response to SSS-III, the magnitude of the antibody response is influenced greatly by the activities of two types of T cells with opposing functions; such regulatory T cells have been termed suppressor and amplifier T cells. The mode of action of suppressor and amplifier T cells as well as the manner in which they might interact during the antibody response to SSS-III are discussed.

Animals↗
PubMedDate not supplied

The induction of immunologic tolerance with type III pneumococcal polysaccharide cross-linked or coupled to protein.

Type III pneumococcal polysaccharide molecules were linked to one another, i. e. cross-linked. The product was essentially insoluble in saline. Large pieces weighing 1-2 mg were inserted into mice. They produced immunologic paralysis or immune tolerance. When placed intraperitoneally in millipore chambers the cross-linked polysaccharide did not have any apparent effect, for the mice were not tolerized. When pneumococcal polysaccharide was linked to a protein, the amount of polysaccharide required to cause tolerance or immunity was essentially the same as the amount of free pure soluble polysaccharide. In addition, Xenopus laevis eggs were injected with a different antigen, bovine gamma globulin, and then with antibody to that antigen. Twelve of the twelve eggs so injected changed shape. Equal numbers of other eggs injected twice with the antigen or twice with the antibody did not change shape.

Agglutinins↗
PubMedDate not supplied

Chain reaction.

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Ethics, Nursing↗