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Biomedical subjects

L Hudson

Publications and source records attributed to L Hudson.

At least 109 records · Page 6Linked to original sources
PubMed1975

Fc-receptors, Ia-antigens, and immunoglobulin on normal and activated mouse T lymphocytes.

Using antibody coated bovine erythrocytes we were unable to demonstrate Fc-receptors on either thymus cells or T cells prepared from lymph node cell suspensions by anti-Ig column filtration. However, if parental thymus or lymph node T cells were transferred to X-irradiated F1 hybrids, activated donor T cells recovered from the recipient's spleen (ATC-spleen) were shown to express Fc-receptors. Fc-receptors were also demonstrable on ATC-spleen prepared between strain combinations differing at the M-locus. In marked contrast, Fc-receptors were not detected on ATC recovered from thoracic duct lymph (T.TDL). This applied to (a) H-2-activated T.TDL derived from normal thymus cells, (b) H-2-activated T.TDL derived from thymus cells depleted of B cells, and (c) M-locus-activated T.TDL. Of these three populations, surface Ig (of B cell origin) was detected on a large proportion of the first but not on the second and third populations. Thus, the failure to detect Fc-receptors on any of these populations could not be attributed to blocking by adsorbed surface Ig. In addition, various T-cell populations were examined by a microcytotoxicity assay for the presence of cell surface Ia-antigens. 5--10% of the thymus cells, 20--30% of cortisone-resistant thymus cells, 60--70% of lymph node cells, and 60--80% of ATC-spleen and T.TDL showed Ia.

Animals↗
PubMed1975

Collaboration of histoincompatible T and B lymphocytes using cells from tetraparental bone marrow chimeras.

T-B collaboration has been studied in a secondary response to sheep erythrocytes using either syngeneic or allogeneic T- and B-cell combinations. T cells prepared from tetraparental bone marrow chimeras (TBMC), carrying H-2 determinants of one parental strain only, cooperated with syngeneic, as well as with allogeneic B cells carrying the alloantigens to which the T cells had been tolerized in the chimeric environment. When TBMC-derived cells of a single H-2 specificity were transferred with a mixture of TBMC-derived B cells of both H-2 types of the parental strains, no preference for syngeneic cooperation was found. The data therefore suggest that the presence of differing H-2-complex determinants on the allogeneic T- and B-cell populations of the two different strain combinations tested do not interfere with T-B collaboration when the cell populations studied are mutually tolerant.

Animals↗
PubMed1975

Specific B lymphocyte suppression by infectious bursal agent (Gumboro disease virus) in chickens.

Chickens infected experimentally with infectious bursal agent (IBA) during embryonation or early after hatching show a severe depression of bursa-dependent lymphoid components, and associated immune functions. Data presented here and elsewhere show that the degree of B cell suppression correlates with the time of infection. This would be compatible with a virus-induced block in B lymphocyte differentiation. Accordingly, the virus may be cytopathic for early (bursal) but not late (circulating) B lymphocytes or, more likely, the virus inactivates those non-lymphoid bursal cells mediating lymphocyte differentiation.

Animals↗
PubMed1975

Immunoglobulin-bearing lymphocytes of the chicken. I. Heavy chain immunoglobulin commitment and organ distribution.

When purified anti-immunoglobulin light chain antibodies were used in indirect immunofluorescence or labeled with 125I for autoradiographic staining, a similar percentage of Ig-bearing lymphocytes were detected by both techniques in lymphoid cell suspensions from the thymus or blood of 8-14-week-old chickens. However, a larger proportion of Ig positive lymphocytes were detected in suspensions of bursal cells by the more sensitive autoradiographic method, suggesting a lower surface density of Ig: perhaps on newly differentiated stem cells. In thymus and spleen suspensions, the proportions of Ig positive lymphocytes carrying mu and gamma-chains were roughly equal, whereas in the B cell populations of the bursa and blood, cells carrying surface gamma-chains predominated. IgA-bearing lymphocytes were only a minor population (< 5%) in lymphocyte suspensions prepared from the thymus, bursa, blood and spleen of adult chickens, but formed almost 50% of the Ig-bearing lymphocytes in the caecal tonsils.

Animals↗
PubMed1975

The bursa dependence of chicken thymus-derived lymphocyte surface immunoglobulin.

Thirty-three plus or minus 5 per cent of chicken blood lymphocytes were positively labelled by radioiodinated rabbit anti-chicken light chain antibody within 7 days of exposure of autoradiographs. After thymectomy, 93 plus or minus 1 per cent of lymphocytes were positive: conversely, following bursectomy only 5 plus or minus 3 per cent of cells showed positive labelling and then at a very low level. Hence, under these conditions of short-term exposure autoradiography, only B cells carried readily demonstrable immunoglobulin. If the sensitivity of the technique was increased by long-term exposure of the autoradiographs, immunoglobulin was demonstrable on all blood lymphocytes, including the T cells. In addition, 39 plus or minus 6 per cent of thymocytes were shown to carry immunoglobulin by the more sensitive technique. In both cases, however, this T-lymphocyte surface immunoglobulin was reduced, and in some cases absent, after bursectomy. At no stage, with either technique, did the grain count on the erythrocytes reach the control level of lymphocytes treated with 125I-labelled anti-keyhole limpet haemocyanin antibody. It seems likely that T-cell immunoglobulin is not an endogenously synthesized product but is acquired indirectly from the B lymphocytes.

Animals↗
PubMed1971

Education and eminence in British medicine.

The educational background of eminent members of the British medical profession was examined by recourse to Who's Who. Substantial differences in background were found among the various medical specialties. Members of specialties enjoying high prestige within the profession-physicians, surgeons-were more likely than other members of the sample to have been to an English school as opposed to one in Scotland, Wales, or Northern Ireland, and to a headmasters' conference school as opposed to a grammar school. Educational background was also found to relate to the aspect of the patient's body on which specialists normally worked. Specialists coming from English headmasters' conference schools were more likely than others to work on living bodies rather than dead bodies or parts of bodies, on the head rather than on the lower trunk, on male bodies rather than female bodies, and on the body's surface rather than its inside.

Education↗