Biomedical subjects
Publications and source records attributed to B Prescott.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The glycolipid haptens of Mycoplasma pneumoniae were bound to membrane proteins of acholeplasma laidlawii (formerly Mycoplasma laidlawii) by reaggregation. This process consisted of the solubilization of lipid-depleted A. laidlawii membranes and M. pneumoniae glycolipids in 20 mM sodium dodecyl sulfate, and dialysis of the mixed solutions against 20 mM Mg(2+). The hybrid reaggregate, collected by centrifugation, was highly immunogenic in rabbits, eliciting the production of a high titer of antibodies that fixed complement with the purified glycolipids and inhibited the metabolism of M. pneumoniae cells. The free glycolipids, or their mixture with A. laidlawii proteins, were much less effective in stimulating these antibodies. The antibodies to the hybrid reaggregate agglutinated M. pneumoniae cells and inhibited their ability to absorb erythrocytes, which indicates that at least some of the serologically-active glycolipids are exposed at the outer membrane surface. The ability to bind selected membrane lipids to membrane proteins of a serologically unrelated species provides a new tool for producing antibodies to lipid haptens.
Mycoplasma pneumoniae lipids were fractionated by combined silicic acid and diethylaminoethyl-cellulose chromatography. The lipid fractions were tested for complement-fixing activity and for blocking of metabolism-inhibiting antibodies in human and rabbit antisera to M. pneumoniae. Thin-layer chromatography and carbohydrate analysis of hydrolysates of the lipid fractions indicated that glycolipids were responsible for the specific serological activities of the lipid extracts of the organism. Phosphatidylglycerol, which accompanied the glycolipids, was serologically inactive when isolated free from glycolipids. Phosphatidylglycerol considerably enhanced the serological activity of the glycolipids, serving as an auxiliary lipid. Because of this auxiliary effect, minute quantities of contaminating glycolipids sufficed to render serological activity to "purified" phosphatidylgylcerol preparations, providing an explanation to the previous identification of the active lipid as a phospholipid.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Formamide-insoluble material was isolated from the L-form of Streptococcus faecium strain F24, but this material was not murein.
Explore the source record for details and available documents.
A method was described for the sensitization of erythrocytes with purified type-specific pneumococcal polysaccharide antigens using chromium chloride as a coupling agent. Erythrocytes so sensitized can be used in routine passive hemagglutination and hemolysis tests as well as in the technique of localized hemolysis-in-gel for the detection of specific antibody and specific antibody-producing cells, respectively.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Monkey, rat, and chicken tracheal epithelial cells, as well as monkey, rat, guinea pig, and chicken erythrocytes, adsorbed firmly to colonies of Mycoplasma pneumoniae and M. gallisepticum. Colonies of M. pulmonis also adsorbed erythrocytes but with less avidity than M. pneumoniae or M. gallisepticum; unlike the latter organisms, M. pulmonis did not adsorb tracheal epithelial cells. Colonies of M. orale type 1 and M. orale type 3 adsorbed only chicken red cells. Other mycoplasma species tested, including four of human origin and one of animal origin, did not adsorb red cells or epithelial cells. M. pneumoniae and M. gallisepticum appeared to attach to erythrocytes or tracheal epithelial cells by neuraminic acid receptors on these cells, whereas M. orale types 1 and 3 and M. pulmonis seemed to utilize another type or other types of receptors. Pretreatment of red cells or tracheal epithelial cells with receptor-destroying enzyme, neuraminidase, or influenza B virus removed the adsorption receptors for M. pneumoniae. Similarly, pretreatment of M. pneumoniae colonies with neuraminic acid-containing materials prevented adsorption of erythrocytes or respiratory tract cells. The adsorption sites on M. pneumoniae were specifically blocked by homologous but not heterologous antisera. This property made it possible to study the nature of the mycoplasma adsorption sites by testing the capacity of different fractions of the organism to block the action of adsorption-inhibiting antibodies. Such studies suggested that the mycoplasma binding sites were probably lipid or lipoprotein in nature. The glycerophospholipid hapten was implicated as one such site, since this serologically active hapten blocked the action of hemadsorption-inhibiting antibodies in M. pneumoniae rabbit antiserum. The affinity of M. pneumoniae for respiratory tract epithelium, unique among the mycoplasmas that infect man, may play a role in virulence, since this type of attachment provides an unusual opportunity for peroxide, secreted by the organism, to attack the tissue cell membrane without being rapidly destroyed by catalase or peroxidase present in extracellular body fluids.