W. De Cock

Restoration of host defense mechanisms in man by levamisole.

Abstract Levamisole, a broad-spectrum anthelmintic, increased the delayed hypersensitivity skin reaction to tuberculin and to DNCB in about one third of the patients. Levamisole and the racemate tetramisole temporarily increased serum antibody titres in response to vaccination against influenza.

The Antihypertensive Effects of a Pure and Selective Serotonin-Receptor Blocking Agent (R 41 468) in Elderly Patients

In a first experiment, an acute intravenous administration of 10 mg R 41 468, a pure serotonin-receptor blocking agent with high selectivity for blood vessels and thrombocytes and devoid of central effects, dramatically reduced systolic and diastolic blood pressure in 23 elderly hypertensive patients. Heart rate and cardiac output remained virtually unchanged. In a second double-blind placebo-controlled cross-over study a highly significant decrease of systolic and diastolic blood pressure was obtained in 14 elderly hypertensive patients during an 8-day oral treatment with 40 mg t.i.d. of R 41 468. No serious side-effects were observed. An oral maintenance therapy with R 41 468 for 3 weeks showed a further reduction of blood pressure, resulting in a normalization of blood pressure, taking into account the advanced age of the patients. R 41 468 most probably acts by decreasing the venous capacitance bed constriction. Essential hypertension might be causally related to an impair ment of venous function, in which serotonin might be an important pressor factor.

The Rheological Effects of Cinnarizine and Flunarizine in Normal and Pathologic Conditions

From the Clinical Research Unit, St. Bartholomeus, Antwerp, Belgium. Cinnarizine and its difluoro derivative, flunarizine, are long-lasting polyvalent antagonists of vasoconstrictive agents.’ They selectively inhibit the calcium transfer to the depolarized vascular smooth muscle.2~3 Both drugs improve exercise tolerance in patients with peripheral obliterative disease’ and enhance blood flow of the lower limbs in both healthy subjects’ and patients with vascular disease. 6-9

The Arteriolar Effects of Cinnarizine and Flunarizine: Multitechnical Investigations in Normal Volunteers and in Patients With Occlusive Disease of the Extremities Secondary To Arteriosclerosis

Multitechnical non-invasive procedures were used to assess the arteriolar effects of cinnarizine and its difluoroderivative, flunarizine, in 20 normal volun teers and in 43 elderly patients with occlusive disease of the extremities due to arteriosclerosis, 22 of whom had intermittent claudication. The trial involved six separate studies of which three were double-blind cross-over, one was a 6- month open study followed by a 6-month double-blind study and two were open studies. Significant drug-related effects were obtained by venous occlusion plethysmometry, differentiated pulse plethysmometry, oscillometry, claudicom eter, postexercise arm-ankle pressure gradients and exercise tolerance measure ments, but not by light plethysmometry and skin temperature measurements. The results indicated that cinnarizine and flunarizine improved vascular disten sion and blood flow in normal volunteers, as well as in patients with occlusive disease of the extremities due to arteriosclerosis. The patients also showed increased postexercise arm-ankle pressure gradients, improved arterial pulsa tions and better exercise performance and tolerance. The drugs were devoid of effects on sympathetic reflexes, resting blood pressure and pulse rate; they were devoid of side-effects and were well tolerated also by patients treated with antihypertensives and cardiac glycosides. Flunarizine was at least as effective as its parent compound at two to three times lower dose levels.

Measurement of mitogen stimulation of lymphocytes with a glucose consumption test.

The increase of glycolysis in mitogen-stimulated lymphocytes was used to quantify lymphoblast transformation. Results correlated well with those by common methods, i.e. morphological evaluation and [3H]thymidine incorporation. The advantage of the glucose consumption test is that it registers the entire event of lymphocyte proliferation whereas other methods evaluate only viable transformed cells at the end of culture.

An enzyme immunoassay for the enumeration of peripheral human T-lymphocytes with OKT3.PAN monoclonal antibody

Abstract An enzyme immunoassay is described for the enumeration of peripheral human T-lymphocytes with a monoclonal antibody OKT3.PAN defining an antigenic determinant present on all mature T-lymphocytes. The method is compared with the indirect immunofluorescence technique and with an E-rosette test.

Enumeration of T-lymphocytes and T-lymphocyte subsets in rheumatoid arthritis using monoclonal antibodies.

SummaryThe number of T-lymphocytes and T-lymphocyte subsets was measured in peripheral blood of 51 patients with rheumatoid arthiritis. T-lymphocytes were counted by E-rosette tests and by the immunogold staining method with OKT3.PAN monoclonal antibody. Helper and suppressor T-lymphocytes were determined by the immunogold staining method with OKT4.IND and OKT8.SUP monoclonal antibody. The relative and absolute numbers of T-lymphocytes and helper T-lympohocytes in peripheral blood of patients with RA did not differ significantly from those in the blood of healthy subjects. However, the relative and absolute numbers of suppressor T-cells were significantly lower in patients with RA than in healthy subjects. The decrease of suppressor T-cells in the blood of patients with RA dit not correlate with the activity of the disease nor the presence of the rheumatoid factor.