Cord blood (CB) as a new source for bone marrow transplantation represents advantageous features concerning stem cell and leucocyte compartments and function. We attempted to get more information about the phenotypes and function of CB cells by investigating their cell surface markers and also the production of IL-2, IFN-gamma and IL-6 by mitogen and alloantigen stimulation. The CB cells were characterized by a low proportion of CD3+ T cells, CD4+ T subpopulation, activated T cells and CD3+CD16/CD56+ cytotoxic cells, suggesting reduced graft versus host potential. The significant increase of CD19/CD3 double positive cells and decrease of CD19/HLA-DR double positive mature B cells reflect that immature B cells exist in CB. In the functional studies, a 27- and 5-fold reduction was observed in the production of IFN-gamma by CB cells stimulated with PHA and allogeneic cells, respectively. The production of IL-2 in PHA-stimulated CB cells also showed a 50% determination. Decrease in the production of these cytokines by CB cells is supported by the decline of the proportion of CD3+ T cells. However, an increase was observed in the production of IL-6 by CB cells stimulated with allogeneic cells as compared with the controls. These results suggest a difference in the functional activity of the T helper cell subsets between the CB and peripheral blood and/or differences in the functional maturity of T helper cell subsets and B cells in these compartments.

Summary.The mechanisms of insulin insensitivity in diabetes are poorly understood. We have therefore assessed the relationship between glucose disposal during a euglycaemic clamp, muscle glycogen formation, and the activities of insulin regulated enzymes within skeletal muscle in five Type I (insulin-dependent) diabetic patients, both on conventional injection therapy (HbA1 11.0-4-1.0 (SD) %) and after 6 weeks continuous subcutaneous insulin infusion (HbA1 7.6 + 1.4%, p < 0.01). On both regimens, overnight euglycaemia before the clamp was maintained with an intravenous insulin infusion. The increase in clamp glucose requirements (insulin 0.1 Ukg-1. h-1) between injection therapy and continuous subcutaneous insulin infusion was significant (6.2+0.9 (SE) to 7.0_0.9mg.kg-l.min -1, p<0.05), but small compared to differences between subjects. Glucose requirement remained lower than in control subjects (10.4+0.7mg.kg-l.min 1, p < 0.05). The increase in muscle glycogen with the clamp was slightly higher on continuous subcutaneous insulin infusion (9.5±2.5mg/g protein) than on injection therapy (8.5± 2.4rag/g, p <0.05), but less than in control subjects (17.9± 2.1 rag/g, p < 0.05). The expressed activity of glycogen synthase and pyruvate dehydrogenase increased significantly between fasting and the end of the clamps in the patients (p < 0.001 and < 0.005), but was not significantly different between the two treatment regimens. Expressed glycogen synthase activity at the end of the clamp was lower on both treatments than in control subjects (p<0.05). Both enzyme activities were, however, highly correlated with glucose requirement between patients, (r = 0.89-0.94, p < 0.05-0.02), and glycogen synthase was similarly correlated in the control subjects (r = 0.84, p < 0.05). Patients had significantly different enzyme activities, glucose requirement, and glycogen stored by analysis of variance (p < 0.05-0.01). Correlation of each enzyme activity between subjects on the two treatment regimens was also high (r = 0.94-0.98, p < 0.02-0.01). At the end of the clamp the enzyme activities were themselves closely related (injections r = 0.99, p < 0.001 ; infusion r = 0.88, p < 0.05), and glycogen synthase activity predicted muscle glycogen deposition (r = 0.94-0.97, p < 0.02-0.01). We suggest that: (1) preceding metabolic control has a relatively small influence on whole body insulin sensitivity measured immediately after careful overnight control; (2) insulin sensitivity derived from glucose clamp data is strongly related to skeletal muscle glycogen deposition and skeletal muscle enzyme activities.

Authors recommend the triple basal treatment consisting of metformin, physical exercise and low glycaemic index diet to their patients with polycystic ovary syndrome for assessment of its long-term efficacy.

The effect of H1 and H2 receptor-blocking agents on antibody-dependent cell-mediated cytotoxicity (ADCC) was studied. The H1 receptor-blocker clemastinum and the H2 receptor blocker cimetidine dose-dependently inhibited the antibody-dependent cytotoxic activity of normal human peripheral blood mononuclear cells on chicken erythrocytes. The inhibition cannot be explained either by a direct toxic effect on effector cells or by blocking of Fc receptors. The possible involvement of histamine receptor-bearing effector cells in human ADCC is suggested.