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Biomedical subjects

R S Farr

Publications and source records attributed to R S Farr.

At least 37 records · Page 2Linked to original sources

Precipitation of radiolabeled antigen-antibody complexes with protein A-containing Staphylococcus aureus.

The feasibility of using protein A-containing Staphylococcus aureus to measure antibodies in sera from several mammalian species was studied. A variety of unrelated radiolabeled antigens were tested, including components of bovine serum, DNA, and bacterial and tumor-associated extracts. The use of S. aureus was found to be a reliable way to detect and measure the primary interactions between many of the antigens and antibodies tested. Results were equivalent under many circumstances to those obtained with the ammonium sulfate and heterologous anti-immunoglobulin methoods. However, some of the limitations noted were that certain antigens bound directly to S. aureus and that all classes of human immunoglobulins tested, in particular IgG3 and IgA1, were not precipitated by S. aureus. If these limitations are taken into consideration, the use of S. aureus can be of value in studying immunochemical reactions with other antigens.

Ammonium Sulfate↗

Primary interaction between antibody and components of Alternaria. I. Immunology and chemical characteristics of labeled antigens.

Components were isolated from Alternaria tenuis and its culture filtrate, and were radiolabeled with 123-I. The labeled antigenic components had a high polysaccharide content as determined by staining patterns following electrophoresis in polyacrylamide gels and by inactivation with sodium metaperiodate. A primary binding test was employed to detect and measure serum antibodies to the components from A. tennuis. This procedure was more sensitive in detecting antibodies that bound to antigens than were comparable tests dependent upon precipitin types of reactions. The labeled components of A. tenuis cross-reacted or shared antigens with 3 other species of molds: Stemphylium sp., Curvularia sp., Aspergillus fumigatus, but not with a variety of other fungal and nonfungal materials.

Alternaria↗

Primary interaction between antibody and components of Alternaria. II. Antibodies in sera from normal, allergic, and immunoglobulin-deficient children.

Antibodies in sera from normal, allergic, and immunoglobulin-deficient children were studied for binding to radiolabeled components of Alternaria tenuis. Significant binding levels were found in 103 of 105 sera from normal children. The levels were age-dependent, rising from a low point in the 7- to 12-month age group to adult levels by the age of 8 years. Levels of binding to two antigens, a culture filtrate derivative (125I-CLF) and a mycelial derivative (125-I-HS), were similar. Sera from asthmatic children with strong immediate skin test reactions to Alternaria extracts bound significantly higher levels of 125-I-CLF than did sera from allergic children with negative skin tests or from control children. Binding levels in sera from children with hypogammaglobulinemia were significantly less than binding levels in sera from normal children in any age group. Sera from children with selective IgA deficiency bound 125-I-CLF at normal levels. The almost universal occurrence of anti-Alternaria antibodies in children was partly explained by the finding of partial cross-reactivity and/or shared antigens among several fungal species, including A. tenuis, Stemphylium sp., Curvularia sp., and Aspergillus fumigatus. The biological significance of these antibodies is not clear, but the procedures described lend themselves to further investigations.

Adolescent↗

A comparison of methacholine and histamine inhalations in asthmatics.

Bronchial provocation tests using aerosolized serially diluted histamine and methacholine were given to nearly 200 asthmatics. Results were usually reproducible for a given patient and corticosteroids did not influence the procedures. Those patients who could tolerate high doses of methacholine were statistically the least severe asthmatics as measured by their discharge dose of corticosteroids. Reaginmediated asthmatics could not tolerate the higher doses of histamine. These tests help delineate subgroups of asthmatics and may have clinical usefulness since, when combined with other data, they differentiate pathogenetic mechanisms in some patients and suggest therapeutic approaches in others.

Administration, Intranasal↗