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Biomedical subjects

U Singh

Publications and source records attributed to U Singh.

At least 127 records · Page 7Linked to original sources
PubMed1979

Effect of catecholamines on lymphopoiesis in fetal mouse thymic explants.

Fetal thymic explants (14 days of gestation) from Balb/c mice were grown in organ culture for up to 12 days and the pattern of lymphopoiesis was monitored by 125IUdR incorporation and cell yields of such lobes in the presence of adrenergic agents. It was observed that, after 3 days of cultures, phenylephrine stimulated lymphopoiesis in thymic explants, whereas some inhibition was observed with isoproterenol. These observations were confirmed by autoradiography. It was also observed that cells obtained from phenylephrine-treated cultures had greater mitogen reactivity than either control (untreated) or isoproterenol-treated cultures. The possible role of cyclic nucleotides as intracellular mediators of thymocyte maturation is discussed.

Animals↗
PubMed1976

Studies on the maturation of thymus stem cells. The effects of catecholamines, histamine and peptide hormones on the expression of T cell alloantigens.

Studies have been performed in order to investigate the effects of catecholamines. histamine, peptide hormones and various other agents known to increase cellular adenosine 3':5'-cyclic monophosphate (cAMP) levels on the expression of Thy-1 and TL antigens on 14-day fetal thymic stem cells. It has been shown that the proportions of Thy-1 and TL positive cells, as detected by dye exclusion cytotoxicity tests, can be significantly increased by some of these agents and that these effects may be inhibited by beta adrenergic and H2 antagonists. The value of these tests as a means for studying normal thymic stem cell maturation and for investigating T cell deficiency is discussed.

Animals↗
PubMed1975

Studies on the effect of various agents on the maturation of thymus stem cells.

Experiments were carried out on 14-day fetal mouse thymic stem cells which were treated with agents known to increase cellular cAMP levels for a period of 90 min at 37 degrees C. When compared to controls, a high proportion of treated stem cells were found to develop Thy-1 (theta) antigen as indicated by dye exclusion tests using anti-Thy-1 serum and complement.

Animals↗
PubMed1975

Effect of prostaglandin F2 alpha on the neurohypophysis. A histochemical study.

Ten micrograms of PG F2 alpha in distilled water were injected intraperitoneally into thirty non-pregnant female rats and their hypophysis was studied after aldehyde-fuchsin and performic acid-alcian blue staining. A definite depletion of posterior pituitary principle was observed in the hypophysis. The role of oxytocin in relation to the oxytocic effect of prostaglandin F2 alpha is discussed.

Animals↗