Search PubMed⌕ Search

Biomedical subjects

M Brunner

Publications and source records attributed to M Brunner.

At least 163 records · Page 9Linked to original sources

Enzyme immunoassay of H-Y antigen: experimental and clinical applications.

A newly developed enzyme-linked immunosorbent assay (ELISA) was applied for studying H-Y antigen in buffaloes, cattle, horses and humans. A monoclonal H-Y antibody was absorbed with cells from males or females and was then tested against fluid samples known to contain soluble H-Y antigen. In this system, positive absorption manifested itself by a fall in optical density relative to the optical density scored using unabsorbed antibody; this finding signified the presence of H-Y in the absorbing cells. In each of the four species, the fall in optical density was pronounced after absorption with male cells, but some decrease was also evident after absorption with female cells, indicating a degree of nonspecific attachment of the antibody.

Animals↗

[Delayed development of hemispheric dominance accompanied by a rare form of retarded language development].

A severe and unusual form of retarded speech development in an eight-year old boy is analyzed as "right-hemispheric speech" against the background of neuropsychological theories on the specialisation of the cerebral hemispheres and considered in connection with the development of hemispheric dominance. A plan for therapy and teacher counselling is derived from this analysis. The influence of this retarded speech development on the acquisition of reading and writing is also touched upon.

Attention↗

H-Y typing in the ELISA.

In a series of quantitative absorptions, biotin-conjugated monoclonal H-Y antibody was reacted with a plated source of H-Y antigen in the ELISA. H-Y was demonstrated in testis supernatant fluid of the mouse in this system, and in cells from males of the mouse, bovine and human and females of the chicken, thereby confirming its evolutionary persistence, and underscoring its presumptive role in the primary determination of vertebrate sex.

Animals↗

On the secretion of H-Y antigen.

It has been proposed that H-Y antigen secreted by cells of the Sertoli lineage is bound by receptors on these and other cells of the primordial gonad and thereby initiates formation of the testicular cords, and that H-Y is not an integral transmembrane component but a part of a ternary system with beta 2-microglobulin and products of the MHC. It follows that cultured Daudi cells, which lack beta 2-microglobulin and HLA, should secrete H-Y. This is consistent with evidence obtained with monoclonal H-Y antibody and an ELISA. By this method, free H-Y was demonstrable in the supernatant fluids of cultured Sertoli cells and Daudi cells. The assay provides a useful alternative to detection of H-Y in the complement-dependent cytotoxicity test.

Animals↗

H-Y antibodies recognize the H-Y transplantation antigen.

The question is raised whether the H-Y transplantation antigen, as defined by skin graft rejection, is the same as the "male-specific" antigen that is identified by H-Y antibodies. We have addressed that question by injecting female mice of the inbred C57BL/6 strain with serologically defined H-Y antigen, and measuring the response of those female mice to skin grafts from intrastrain male mice. The results of our study indicate that the "two" male antigens are crossreactive or identical.

Animals↗

Folate deaminase and cyclic AMP phosphodiesterase in Dictyostelium discoideum: their regulation by extracellular cyclic AMP and folic acid.

Cyclic AMP and folic acid act as chemotactic factors in Dictyostelium discoideum. Both agents, when applied extracellularly, also control cell development from the growth stage to the acquisition of aggregation competence. Cyclic AMP phosphodiesterase and folate deaminase are extracellular enzymes whose activity is regulated during early differentiation of D. discoideum cells. The two enzymes help control the extracellular levels of cyclic AMP and folic acid. The substrates cyclic AMP and folic acid each increase the extracellular activity of folate deaminase as well as phosphodiesterase. The specificity of extracellular phosphodiesterase regulation by cyclic AMP indicates that the effect is mediated by specific cyclic AMP receptors rather than the catalytic site of cell surface phosphodiesterase. To some extent cyclic AMP and folic acid are interchangeable with respect to regulating differentiation and enhancing enzymatic inactivation of intercellular signals. Thus the two extracellular signals may share a common cellular pathway of signal transduction. The regulation of folate deaminase and phosphodiesterase by folic acid does not always parallel the folic acid effects on development. Pulses of folic acid stimulate development of aggregation competence, whereas a continuous flux inhibits. In contrast, either continuous flux or pulses of folic acid increase the deaminase and phosphodiesterase activities.

3',5'-Cyclic-AMP Phosphodiesterases↗