摘要:

Abstract.To determine whether the Fc‐receptor function of reticuloendothelial system (RES) is modified by corticosteroid administration, we studied the spleen to liver uptake ratios of autologous,99Tc‐labelled heatdamaged or IgG‐coated erythrocytes, injected intravenously into 10 normal volunteers, 4 h after receiving a single dose of 32 mg of methylprednisolone by mouth.In standard conditions, quantitative scans indicated that the spleen to liver uptake ratios, calculated per unit area 40 min after the injection of labelled erythrocytes, were 13·4 ± 0·6 and 31·2 ± 1·5 (mean values ± ‐SEM), for the heat‐damaged (n= 7) and IgG‐coated red cells (n= 5) respectively. Four hours after corticosteroid administration, the spleen to liver uptake ratios were significantly reduced in five of ten volunteers. Abnormal ratios correlated with the Fc‐receptor function of monocytes measuredin vitrousing IgG‐coated erythrocytes. Indeed, 2–6 h after methylprednisolone was given, the Fc‐receptor binding activity of monocytes isolated from the same five subjects was reduced by at least 50%, spontaneously returning to a rather normal value 4–6 h later. The C3‐receptor binding activity of these monocytes remained normal, after otherwise identical experimental conditions.These results show a transient, specific impairment of the Fc‐receptor function of RES after methylprednisolone administration, and may therefore explain, in part, the infectious complications occurring in some pat

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1984.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.The fate of noradrenaline released from sympathetic endings differs from that of noradrenaline secreted directly into the bloodstream. This has been used to establish a single sample test for the exclusion of phaeochromocytoma in patients with borderline elevation of plasma noradrenaline concentration. This test is based on the measurement of the ratio in plasma of noradrenaline to its deaminated metabolite, dihydroxyphenylglycol (DHPG). The latter was shown to reflect mainly nervous release of noradrenaline and its plasma concentration was not increased during intravenous noradrenaline infusion. In seventeen phaeochromocytoma patients the ratio in plasma of noradrenaline to DHPG was greater than 2 (range 2·05–3·57); in nineteen non‐phaeochromocytoma patients the reverse was found, the ratio of DHPG to noradrenaline being greater than 2 (range 2·08–2·74). Since DHPG can be measured simultaneously with noradrenaline, measurement of the plasma ratio of these two catechols may prove a simple method of differentiating phaeochromocytoma from non‐phaeochromocyto

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1984.tb00706.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Treatment with hypolipidaemic drugs such as clofibrate increases secretion of biliary cholesterol and induces supersaturation of bile, leading to an increased risk of gallstone formation. Ciprofibrate is a phenoxyisobutyrate derivative with lipid‐lowering effects in hyperlipoproteinaemia. We analysed serum lipid levels and biliary lipid composition and cholesterol saturation of gallbladder bile in nineteen hyperli‐poproteinaemic patients before and after 6 weeks treatment with ciprofibrate, 100 mg daily. In addition, hepatic secretion rates of biliary lipids were determined in eight of the patients. Ten of the patients were also studied after 1 year of treatment.Short‐term treatment reduced the serum cholesterol levels by about 20% (P<0·001) and the serum triglycerides by about 40% (P<0·001). The relative cholesterol concentration and cholesterol saturation of bile were not significantly increased for the group as a whole, nor in patients with familial hypercholesterolaemia (n= 9), or with other types of hyperlipidaemia (n= 10). During treatment, however, fourteen patients had saturated bile compared with nine before treatment. An increase in cholesterol saturation was the consequence of an increased hepatic secretion of cholesterol whereas the secretion rates of bile acids and phospholipids were unaffected.After 1 year of treatment the serum lipid concentrations were reduced to about the same level as after 6 weeks, whereas biliary lipid composition and cholesterol saturation had returned to pre‐treatment values.In contrast to clofibrate ciprofibrate exerts hypolipidaemic effects without consistently increasing the relative cholesterol concentration in bile. In some patients it leads to a transient rise in cholesterol saturation of gallbladder bile. This effect is due to an enhanced secretion of cholesterol probably because of a mobilization of tissue ch

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1984.tb00707.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abstract.Hormone sensitive adenylate cyclase consists of at least three components; hormone receptor, a catalytic unit, and the N‐protein, which couples the receptor to the catalytic unit. Human erythrocytes have very low adenylate cyclase activity, but do have N‐protein activity. We have investigated the fate of the catalytic unit and the N protein during maturation of human reticulocytes. We compared red blood cell membranes derived from nine patients with reticulocytosis averaging 12% to erythrocyte membranes from eight normal subjects. The catalytic unit was assayed by stimulation of adenylate cyclase with forskolin, and the N‐protein activity by anin vitrocomplementation assay. Forskolin stimulated adenylate cyclase activity was ten times higher in membranes derived from patients with reticulocytosis as compared with those of normal subjects. N‐protein activity was only slightly (12%) and insignificantly (P= 0·08) higher in the reticulocytosis patients membranes. We conclude that during maturation of the human erythrocyte there is a differential loss of the catalytic unit of adenylate

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1984.tb00708.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

ISSN:0014-2972    

DOI:10.1111/j.1365-2362.1984.tb00694.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY