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Biomedical subjects

C A STETSON

Publications and source records attributed to C A STETSON.

At least 19 recordsLinked to original sources
PubMed1965

THE EXPRESSION OF HISTOCOMPATIBILITY ANTIGENS ON CELLULAR AND SUBCELLULAR MEMBRANES.

The mouse isoantigens determined at the major histocompatibility locus known as H-2 have been found to be closely associated with the cellular surface membranes, with the membranes of the endoplasmic reticulum, and probably with those of the lysosomes as well. Mitochondrial membranes, on the other hand, show little or no H-2 antigen activity. Membrane material prepared from certain tissues, including brain and muscle, have no detectable H-2 antigenic activity. Evidence is presented which indicates that all of the H-2 antigens of the genome are expressed as a unit, supporting the hypothesis that the complex H-2 genetic locus consists of a single cistron. It is postulated that these histocompatibility antigens form some structural or functional unit in the membranes of cells.

Acid Phosphatase↗
PubMed1961

Humoral aspects of the immune response to homografts. II. Relationship between the hemagglutinating and cytotoxic activities of certain isoimmune sera.

Isoimmune sera, prepared in BALB/c mice by immunization with living or lyophilized tissue from C57Bl/6 mice, were found to possess both hemagglutinating and cytotoxic activity for donor cells. Comparative titrations indicated a good correspondence between these two activities. Absorbtion with living or dead donor tissue caused removal or proportionate reduction of both activities. The results are consistent with the existence in isoimmune sera of a single class of isoantibodies, capable of agglutinating donor cells or of sensitizing them for complement lysis. Living and lyophilized tissue differ quantitatively, but not qualitatively, in their capacity to induce formation of these antibodies.

Allografts↗
PubMed1960

Studies on the mechanism of the Shwartzman phenomenon. Accelerated cutaneous reactivity to bacterial endotoxins.

Rabbits given single injections of endotoxin and then skin-tested with endotoxin from 1 day to 1 month later exhibit accelerated skin reactions resembling the Arthus phenomenon. Injection of one endotoxin alters the subsequent reactivity of rabbits to other endotoxins as well. The state of altered reactivity can be transferred with serum, and appears to be related to the presence of non-precipitating cross-reactive antibody, rather than to specific precipitating antibody.

Antitoxins↗
PubMed1960

Immunologic cross-reactions among mammalian acute phase proteins.

Crystalline rabbit Cx-reactive protein has been compared immunologically with the analogous crystalline C-reactive protein of man. Immunologic cross-reactivity has been demonstrated between the acute phase proteins of man, rabbit, and monkey. Double-diffusion reactions in agar and passive cutaneous anaphylaxis reactions in vivo both indicate that these acute phase proteins are antigenically closely similar but not identical. Guinea pigs with delayed hypersensitivity to C-reactive protein exhibit delayed skin reactions when tested with Cx-reactive protein and vice versa.

Acute-Phase Proteins↗
PubMed1959

An effect of antigen-antibody interaction on blood coagulation.

Each of several antigen-antibody systems studied has been found to affect the coagulation mechanism in the rabbit, causing a marked shortening of the coagulation time in vitro of samples of whole blood maintained in siliconized glassware. Addition of specific antigen to the blood of actively immunized animals or addition of antigen-antibody mixtures to the blood of normal animals produced the effect. The coagulation time of plasma was not affected, indicating that the phenomenon may be mediated by an effect on platelets. This effect of antigen-antibody interaction may be involved in the production of tissue damage in vivo.

Alopecia↗
PubMed1956

The endotoxic properties of lysates of group A hemolytic streptococci.

Suspensions of group A streptococci were subjected to mechanical disruption by shaking with glass beads. The supernatant solutions produced severe delayed inflammatory reactions on intradermal injection into normal rabbits. Intravenous injections caused systemic reactions characterized by fever, leucopenia, and peripheral vasomotor phenomena. These effects were more pronounced in rabbits which had previously been infected with group A streptococci. The local and generalized Shwartzman phenomena were reproduced with these crude streptococcal lysates, and the data suggest that streptococci possess an endotoxin similar to those of Gram-negative bacterial species.

Animals↗
PubMed1955

Studies on the mechanism of the Shwartzman phenomenon; similarities between reactions to endotoxins and certain reactions of bacterial allergy.

The cutaneous, ophthalmic, and systemic reactions of normal rabbits to Gram-negative bacterial endotoxins have been compared with the classical reactions of bacterial hypersensitivity, and in each case certain similarities have been found. It has also been shown that the Shwartzman phenomenon can be reproduced with tuberculin, in BCG-vaccinated rabbits, and with suspensions or extracts of heat-killed Group A streptococci in rabbits previously sensitized to these bacteria. These considerations suggest the hypothesis that the biologic activity of endotoxins may be based on the existence in "normal" animals of delayed or tuberculin-type hypersensitivity to these materials.

Animals↗