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Biomedical subjects

L G Norman

Publications and source records attributed to L G Norman.

9 recordsLinked to original sources
PubMed1982

Fractionation of Pneumocystis carinii antigens used in an enzyme-linked immunosorbent assay for antibodies and in the production of antiserum for detecting Pneumocystis carinii antigenemia.

Cyst-rich suspensions of Pneumocystis carinii were obtained by differential and gradient centrifugation from heavily infected rat lungs. After preparation of an aqueous-soluble extract of the cyst-rich material, the insoluble residue was extracted with 8 M urea. Small amounts of infected human lung tissue and uninfected rat and human lung were processed similarly. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that both human and rat infected lung extracts contained a large protein (greater than 200,000 daltons). This component was not present in extracts of uninfected lung. In addition, an HCl-soluble extract was prepared from the cyst-rich suspension from infected rat lung. The urea-extracted antigen was most reactive in an enzyme-linked immunosorbent assay. Rabbit antiserum against the HCl-soluble antigen detected circulating antigen in patients' sera in a counterimmunoelectrophoresis assay.

Animals↗
PubMed1982

Detection of specific antibody by enzyme-linked immunosorbent assay and antigenemia by counterimmunoelectrophoresis in humans infected with Pneumocystis carinii.

A urea-soluble extract of cyst-rich material from rat lung heavily infected with Pneumocystis carinii was evaluated in an enzyme-linked immunosorption assay for antibody in 461 human sera. The highest level of reactivity occurred in sera submitted for serodiagnosis from proved or highly suspect cases. However, the range of reactivities in these groups, many of whom were on immunosuppressive therapy, was very wide. A more restricted lower range of reactivity was observed in both hospital-family contacts and healthy Serum Bank donors. Because of the overlap in levels of reactivity between the pneumocystosis and control groups, no concise cutoff value to separate infected from noninfected individuals could be made. Specificity of the reactions was shown by absorption of patients' and control sera with uninfected and P. carinii-infected human and rat lung tissue. The data support the concept that P. carinii is highly prevalent as a latent agent in the general population and is provoked to cause clinically manifest disease in the compromised host. Detection of circulating antigen appeared to be specific and possibly a useful adjunct to diagnosis, as 10 of the 14 proved or highly suspect patients with antigenemia did not have measurable antibody to P. carinii.

Antibodies↗
PubMed1978

Immunologic studies on hamsters infected with Entamoeba histolytica.

The serologic and cell-mediated immune responses of hamsters exposed to 2 strains of Entamoeba histolytica (HM-1 and HM-19) were evaluated by a series of in vitro tests. The pathogenicity of the 2 strains was evaluated in terms of their ability to produce liver abscesses and spleen enlargement. Antibody response was evaluated by the indirect hemagglutination test. The cellular immune response was assayed by increased DNA synthesis by lymphocytes and migration inhibition of macrophages.

Amebiasis↗
PubMed1977

Serial propagation of Pneumocystis carinii in cell line cultures.

Pneumocystis carinii was propagated on three cell lines routinely cultured in many laboratories; the method is practical and convenient. Organisms produced were found to be reactive to Pneumocystis antisera. Studies of antigenic relationships, life cycles, and diagnostic methods will be made easier by these cultures.

Animals↗
PubMed1976

Serology of pneumocystosis.

Included in this evaluation of serologic tests for American pneumocystis pneumonia is a summary of results reported from an indirect immunofluorescence (IF) test and a comparison of results of the immunodiffusion, complement-fixation, and double diffusion tests. Athough IF was the most sensitive, it dectected only a third of the infections. Specificity of the test was good when serum titers greater than or equal to 1:16 were considered postive. Results of test sera in both European and American laboratories suggested that the low level of measurable antibody in American sera real and not due to technical error. These findings are compatible with the concept that two types of population may be infected with Pneumocystis organisms, one type associated with plasma cell pneumonia and the second with hypoergic pneumocystosis in immunosuppressed patients. Analysis by double diffusion to test antigens revealed their antigenic complexity. Most components, were indentified or partially identified with host elements, and no purely parastic antigens were demonstrated. When cysts isolated from animals and humans were tested, results suggested that they shared at least some common antigens.

Animals↗