Sotiros D. Chaparas

Tuberculin-Active Carbohydrate That Induces Inhibition of Macrophage Migration but not Lymphocyte Transformation

A tuberculin carbohydrate fraction, GAE, in sensitized animals induced a delayed type of skin reactivity and inhibited the migration of macrophages but failed to stimulate lymphocyte transformation in vitro. Tuberculin protein-containing fractions were active in each test. These results show that in vitro lymphocyte transformation is not necessarily a corollary of delayed type hypersensitivity.

Tuberculin Reactivity of a Carbohydrate Component of Unheated BCG Culture Filtrate.

Carbohydrate and protein fractions from the filtrate of a culture of Mycobacterium bovis strain BCG have equal activity in sensitive guinea pigs. The sequential action of two proteolytic enzymes caused little alteration in the reactivity of the carbohydrate but almost completely eliminated the reactivity of the protein.

Antigenic Relationships Among Species of Mycobacterium Studied by Fused Rocket Immunoelectrophoresis

The fused rocket immunoelectrophoresis procedure is a sensitive procedure for detecting precipitating antigens in extracts of mycobacteria. A number of preparations can be run simultaneously and in parallel with the production of lines of identity. The increased sensitivity and facility of identification make this procedure a very promising one in the study of taxonomic relationships.

Terminology Guidelines for Serotaxonomic Studies Using Immunodiffusion and Immunoelectrophoresis

We propose guidelines for terminology for the immunodiffusion and immunoelectrophoresis methods used in serotaxonomy. These guidelines were prepared at the request of the International Working Group on Mycobacterial Taxonomy, which endorsed them in 1981.

Mycobacterium intracellulare Reference Precipitation System

Characteristics of a Mycobacterium intracellulare reference precipitation system for immunodiffusion and immunoelectrophoresis analyses are presented. The system was produced by the initiative of the International Working Group on Mycobacterial Taxonomy, and the purpose is to permit comparisons of precipitinogenic patterns of mycobacteria obtained in different laboratories. The reference material, consisting of an antigen preparation and a corresponding antiserum, is available for students of mycobacterial antigens in accordance with guidelines adopted by the Working Group.

Analysis of Antigens of Rhodococcus Species by Rocket Immunoelectrophoresis

Seventeen representative strains of Rhodococcus and related taxa were analyzed for antigenic relationships by rocket immunoelectrophoresis. A good correlation was found between data from this form of analysis and previously reported numerical phenetic and deoxyribonucleic acid reassociation data. Rhodococcus ruber and Rhodococcus erythropolis strains formed distinct clusters in a dendrogram produced by average linkage analyses for dissimilarity matrices. Rhodococcus equi, Nocardia asteroides, and an unidentified Rhodococcus strain formed single-member clusters, whereas Rhodococcus coprophilus was found to be heterogeneous. In contrast, R. erythropolis and R. ruber were found to be distinct species. The discrepancies between deoxyribonucleic acid pairing and rocket immunoelectrophoresis results can be explained on the basis of suboptimal antigen or antiserum preparations.

A Laboratory Procedure for determining the Potency of Toxoplasmins for Skin Testing.

Summary Delayed skin reactivity has been induced in guinea pigs to soluble extracts of toxoplasmata grown in a stable line of monkey kidney tissues and combined with complete Freunds adjuvant. Sensitized guinea pigs exhibited intense delayed reactions to toxoplasmins derived from either infected mice or embryonated eggs. The possible use of this procedure for determining the potency of toxoplasmins of heterogeneous sources has been discussed.

Lowered Delayed Skin Reactivity to Fractions of Mycobacterium bovis (BCG) in Guinea Pigs Sensitized with Large Doses of BCG

Summary Different optimal doses of heat-killed Mycobacterium bovis (BCG) were required to sensitize guinea pigs maximally toward fractions FB (largely protein) and GB (50% protein and 50% carbohydrate) prepared from culture filtrates of BCG. Increasing the sensitizing dose beyond the optimum resulted in lesser skin sensitivity for each antigen. No circulating antibodies were detected towards GB, which was the more skin reactive fraction. Complement-fixing and precipitating antibodies were produced toward FB but could not be correlated with the dose of injected organisms.

Laboratory procedures for potency testing of blastomycin, histoplasmin, and coccidioidin.

Summary Ways to induce sensitization in guinea pigs for use in assays for histoplasmin, blastomycin and coccidioidin were investigated, using various combinations of spore preparations, skin reactive reagent and mycobacteria incorporated in water-in-oil emulsions. It was possible to induce high levels of sensitivity to the skin reactive reagents, but the level of sensitization varied widely, depending on the combination of ingredients in a sensitizing preparation. The addition of mycobacteria sometimes caused either a decrease or an increase in the level of sensitization. The authors are indebted to Mr. Clifford Maloney and Mrs. Arvilla Webb for the statistical analyses and to Mrs. Sally Hedrick and Mr. Rubin Marquina for excellent technical assistance.

Suppression of toxoplasmin skin reactivity in sensitized guinea pigs by multiple inoculations.

Summary Suppression of the skin reactivity to toxoplasmin by simultaneous injection of larger amounts of the antigen in the same sensitized guinea pigs was demonstrated by fewer animals reacting to the lesser amount of toxoplasmin and a decrease in the mean skin reaction as compared with the reaction when the toxoplasmin was injected alone.