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Biomedical subjects

J T Blake

Publications and source records attributed to J T Blake.

31 records · Page 2Linked to original sources
PubMed1978

Parainfluenza-3 virus exposure of beef heifers prior to natural breeding.

Ninety-six Hereford heifers (approximately 7 months of age) were randomly divided into 2 equal groups and housed 1.6 km apart (with 2 replications in time, 1 year apart). At 15 months of age, 1 group/replicate was inoculated with parainfluenza-3 virus, and the other group was given virus-free spent culture medium. Twenty-four hours later, 2 virgin bulls (2 years old) were placed with each group (24 cows) for natural breeding. Viral inoculation caused a twofold increase in parainfluenza-3 titer and a 0.3 C body temperature increase. There was no effect recognized from the virus on natural breeding efficiency.

Animals↗
PubMed1977

Determinant selection is a macrophage dependent immune response gene function.

Immune response (Ir) genes are linked to the species histocompatibility complex and define as yet uncharacterised phenotypic products which control the immune response to thymus dependent antigens. Antibody formation and antigen induced T lymphocyte proliferation are two examples of immune phenomena which, in vivo and in vitro, operate under Ir gene influence. To clarify their mechanism of action and cellular location, we have examined the contribution of antigen structure (amino acid sequence and conformation to Ir gene control of antigen recognition by T lymphocytes) as well as to the critical role played by the antigen presenting macrophage in expression of that control. We report that immune response gene control of antigen recognition operates at least in part at the level of the macrophage.

Animals↗
PubMed1977

Facility for exercising dairy cows.

That dairy cows housed in confinement might benefit if they were exercised during the dry period prompted development of a facility for exercising dairy cows. Two methhods of the exerciser, which consist of a circular lane and a driving mechanism powered by a variable speed electric motor, are described. A speed of 3.5 k, per h provides a steady but comfortable pace for pregnant dairy cows and heifers. Many animals refused to go at speeds greater than 5.5 km per h.

Animals↗
PubMed1975

Inhibition of macrophage-lymphocyte interaction by cytochalasin B during antigen recognition by T lymphocytes.

The effects of cytochalasin B on functional and physical macrophage-lymphocyte interaction have been examined. Cytochalasin B, an inhibitor of a variety of membrane activities blocks antigen-dependent bindings of immune lymphocytes to macrophages and antigen-triggered lymphocytes proliferation if added at the initiation of culture. Cytochalasin B becomes progressively less inhibitory if addition is delayed by increasing intervals from the onset of culture. Under these conditions neither antigen handling by macrophages nor the proliferative response of lymphocytes to PHA is inhibited by cytochalasin B. These data are interpreted to suggest that cytochalasin B inhibits antigen-specific macrophage-lymphocyte interaction either by inhibition of an initial antigen-independent phase of macrophage-lymphocyte interaction or by interfering with a lymphocyte membrane event necessary for the interaction of the antigen-specific lymphocyte receptor with the macrophage-bound antigenic signal.

Animals↗
PubMed1971

The peritoneal exudate lymphocyte. I. Differences in antigen responsiveness between peritoneal exudate and lymph node lymphocytes from immunized guinea pigs.

Peritoneal exudate lymphocytes from guinea pigs immunized with horse radish peroxidase, dinitrophenyl guinea pig albumin, or ferritin in complete Freund's adjuvant have been shown to be significantly more reactive than other lymphocytes in two in vitro assays of cellular immune function: production of macrophage migration inhibitory factor and antigen-induced lymphocyte proliferation. The enhanced reactivity of peritoneal exudate lymphocytes cannot be accounted for by artifacts introduced by column purification or by the presence of nonlymphoid accessory cells. These observations suggest that the peritoneal exudate lymphocyte pool is a highly enriched source of cellular immune effector cells with specificity directed towards those antigenic determinants to which an animal has been recently exposed.

Animals↗