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Biomedical subjects

G Birnbaum

Publications and source records attributed to G Birnbaum.

50 records · Page 3Linked to original sources
PubMed1978

Lymphocyte transformation induced by autologous cells.

Human peripheral blood T lymphocytes are stimulated to proliferate when cultured with autologous B-lymphoblastoid cell lines, autologous mitogen-induced lymphoblasts, or autologous non-T blood lymphocytes. This reaction, the autologous mixed lymphocyte reaction, has attributes of an immune response possessing both memory and specificity. The capacity to stimulate autologous T lymphocyte proliferation depends on the lineage of the lymphoid cell and not on its establishment in continuous culture or carriage of the EB viral genome. The determinant on non-T lymphocytes which stimulates the autologous mixed lymphocyte reaction appears to be an Ia determinant. Thus, allogeneic graft rejection and the allogenic mixed lymphocyte reaction are very likely extensions of an immune response expressed within the host.

B-Lymphocytes↗
PubMed1977

Thymic lymphocytes in myasthenia gravis.

Lymphocytes from the thymus glands of myasthenic patients and controls were characterized in terms of their percentages of B- and T-cells and their ability to stimulate the proliferation of autologous peripheral blood lymphocytes. Percentages of B- and T-cells were the same in the thymuses of myasthenic and control subjects. Autologous peripheral lymphocyte stimulation by thymocytes was observed in only 1 of 3 myasthenic patients, and this was with a thymus gland containing a thymoma. These results thus differ from those of other investigators.

B-Lymphocytes↗
PubMed1975

Demonstration of an antibody-mediated tolerance state and its effect on antibody affinity.

We have described a model of immunological tolerance induced, in adult mice, by a single injection of a moderate dose of a hapten-protein conjugate. The data suggest that the mechanism of this tolerance state is the production of small amounts of high affinity antibody in response to the tolerance-inducing antigen injection. This antibody acts to inhibit the response to a subsequent challenge with antigen in complete Freund's adjuvant by a mechanism comparable to that of passive antibody-medicated immune suppression. It was shown that a small but high affinity. Tolerance was not terminated by transfer of normal syngeneic spleen or peritoneal cells into tolerant animals. Spleen cells from tolerant mice, when transferred into lethally irradiated, syngeneic animals, produced a PFC response which is greater in magnitude and tolerance state had a significant degree of carrier specificity which was shown to be comparable to the carrier specificity of antibody-mediated immune suppression. hus, evidence was presented to show that one mechanism of tolerance in adult animals in the suppressive effect of small amounts of high affinity antibody formed in response to the tolerizing injection of antigen.

Animals↗
PubMed1975

Studies on brain-thymus cross-reactive antigens.

An antigen(s) shared by mouse brain and thymocytes was studied with the use of a rabbit anti-mouse brain antiserum (RAMB). Full complements of brain-thymus antigen were found on the brains of several mouse strains, including athymic mice, regardless of their theta antigen genotype. Brain-thymus antigen(s) was absent in newborn mouse brains and gradually reached adult levels two weeks after birth. Treatment of mouse brain with trypsin neither decreased nor increased the amount of the brain-thymus antigen available for absorption of RAMB. Mouse brain-thymus antigens were present on rat thymocytes, but not rat brain. The concentrations of brain-thymus antigens were 3- to 4-fold higher in gray matter than white matter. Cross-absorption studies with RAMB and anti-theta antiserum suggest that theta antigen and brain-thymus antigen are two distinct substances, both antigenically and in their anatomical localization on brain cells.

Animals↗
PubMed1975

Determination of antibody avidity at the cellular level by the plaque inhibition technique: effect of valence of the inhibitor.

Inhibition of plaque formation by multivalent and univalent ligands was compared as an assay of avidity of antibody produced by PFC. Multivalent ligands are much more effective as inhibitors and their use tends to impart an appearance of lack of heterogeneity and high avidity to the PFC populations being studied. It is thus probably generally advisable to employ univalent ligands in such studies.

Aminocaproates↗