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Biomedical subjects

R G Hanson

Publications and source records attributed to R G Hanson.

20 records · Page 2Linked to original sources

Effects of immunosuppressive therapy with prednisolone on B and T lymphocyte function in patients with chronic type B hepatitis.

B and T lymphocyte function was studied in 10 patients with chronic type B hepatitis before, during and after a 28-day course of prednisolone therapy. Lymphocyte function was assessed by measuring the in vitro synthesis of immunoglobulin by peripheral blood mononuclear cells stimulated with pokeweed mitogen and by assaying lymphocyte proliferation in response to B and T cell mitogens. During high dose prednisolone therapy, there was a decrease in immunoglobulin synthesis by peripheral blood mononuclear cells and in lymphocyte proliferation to all mitogens. Studies using separated B and T cells showed that prednisolone treatment led to a decrease in both helper and suppressor T cell function but an enhancement of primary B cell function. When prednisolone was withdrawn, lymphocyte function rapidly returned to baseline levels. During prednisolone therapy, serum aminotransferase activities decreased by an average of 50%. In all patients, there was a subsequent rebound increase in serum aminotransferase activities 4 to 10 weeks after withdrawal of prednisolone. This was accompanied by a striking increase in suppressor T lymphocyte activity without significant changes in either helper T cell or B cell function. The close correlation between changes in helper and suppressor T lymphocyte function and serum aminotransferase activities during and after immunosuppressive therapy suggests that immunoregulatory T lymphocytes may play an important role in the pathogenesis of chronic type B hepatitis.

Adult↗

Effect of increased bile flow and bile acid secretion on the hepatic elimination of sodium valproate in the cat.

The effect of increased bile flow and hepatic bile acid flux on the systemic clearance and hepatic elimination of intravenously administered sodium valproate was studied in the bile fistula cat. Taurochenodeoxycholic acid (TCDC), tauro-3 alpha, 7 beta-dihydroxy-12-keto-5 beta-cholanoic acid (T12K), SC-2644, and secretin were infused intravenously to vary bile flow and biliary bile acid secretion. Control animals were infused with 0.15 mol/l NaCl. Less than 1% of the drug administered to controls appeared as unchanged valproate in the bile over 6 h. Although SC-2644, T12K, and secretin significantly increased biliary excretion of valproate, it did not exceed 2% of the intravenous dose. Biliary clearance was directly related to the rate of bile flow, but not to the bile acid flux. By contrast, 18-19% of the dose appeared in bile as metabolite in controls, and none of the choleretic agents significantly increased this percentage. As a result, systemic clearance of valproate was unaltered. We conclude that the movement of unchanged valproate into bile is consistent with a process of simple diffusion. The fact that choleretic agents do not increase metabolite excretion into bile suggests that metabolite formation may be the rate-limiting step in the hepatic elimination of valproate, rather than transport and excretion of metabolites into bile.

Animals↗