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C W Ramsden

Publications and source records attributed to C W Ramsden.

21 records · Page 2Linked to original sources

Does oxpentifylline ('Trental') have a place in the treatment of intermittent claudication?

In a randomized double-blind study, the clinical and haemorrheological responses of 40 patients receiving oxpentifylline (200 mg 3-times daily) were compared with those of 40 patients receiving placebo. The treatment period in both groups was 2 months. The parameters measured before and after treatment were: subjective response; claudication and maximum walking distances; ankle systolic indices; maximum blood flow in the lower limb by gravimetric plethysmography; plasma fibrinogen; erythrocyte deformability and whole blood viscosity. There was a significant increase (p less than 0.05) in mean erythrocyte deformability in the oxpentifylline group but not in the placebo group; this apparent difference between the groups, however, was not significant. The placebo group showed a significant improvement (p less than 0.05) in claudication distance and mean plasma fibrinogen concentration, but no such improvements were observed in the oxpentifylline group. There were no significant differences in either of the two groups with regard to the subjective response, ankle systolic indices, maximum limb blood flow or whole blood viscosity. It is concluded that oxpentifylline , when taken in oral form at the dose used in this study, increased erythrocyte deformability without conferring any clinical or haemorrheological benefit to patients with intermittent claudication.

Adult↗

Sequential changes in NK and ADCC effector cell function after organ transplantation in man.

Antibody-dependent cellular (K cell) cytotoxicity (ADCC) and cellular cytotoxicity against natural killer (NK) targets exerted by the same cells were both measured sequentially in ten patients after renal transplantation using conventional immunosuppression. Cytotoxicity against NK targets appeared to correlate more closely with rejection episodes than did assays of ADCC activity during the same period. An apparent rise in NK activity was frequently accompanied by a fall in ADCC activity. Collectively these data suggest that the previously reported increase in NK activity during rejection episodes may represent a manifestation of the appearance of non-clonally activated T-cells in peripheral blood during rejection.

Antibody-Dependent Cell Cytotoxicity↗

Pharmacological concentrations of lipid emulsions inhibit interleukin-2-dependent lymphocyte responses in vitro.

Most immunological functions are accomplished by means of interactions between mediator molecules (cytokines or lymphokines) and their specific receptors on the lymphocyte surface. One particular lymphokine, Interleukin-2 (IL-2) is central to the generation of most immune responses including those with antitumor activity. Prompted by two clinical trials which have suggested distinct but apparently opposite effects of lipid emulsions on the production of and lymphocyte responses to IL-2 we have examined the effects of pharmacological concentrations of three lipid emulsions currently in clinical use on IL-2 related interactions in vitro. Mitogen-stimulated and IL-2 activated human lymphocyte proliferation were both inhibited in a dose-dependent manner in the presence of all three lipid emulsions although the effects were less marked with the solution in which 50% of the calories are present as medium-chain triglycerides (MCT) rather than long-chain triglycerides (LCT). Similarly the LCT, but less so the MCT-containing solutions inhibited the generation of cytotoxic lymphokine-activated killer cells. These solutions did not inhibit the proliferation of cell lines which are not growth-factor dependent but did inhibit the growth of an IL-2-dependent cell line. We conclude that lipid emulsions can upset IL-2-dependent lymphocyte responses. These observations may lead to parenteral feeding regimens which are less immunocompromising for the tumor-bearing patient.

Cell Division↗