Mechanisms of the platelet proaggregating activity of human carcinoma a431 cells.

An unusual mechanism has been demonstrated for the in vitro proaggregating interaction between human platelets and human epidermoid carcinoma A431 cells. A431 cells induce platelet aggregation in a dodependent manner, depending on the rate of ADP release from tumour cells, which occurs in the presence not only of platelet rich plasma (PRP) but also of platelet poor plasma (PPP) or serum. This ADP release appears to be correlated to C(3) cleavage and binding of C(3c) to the A431 cell membrane.

Chronic obstructive pulmonary disease. A possible correlation between platelet aggregation tests and respiratory indexes. ECOB Group.

It has been suggested that thrombotic events occurring in patients with chronic obstructive pulmonary disease could be partially due to abnormalities in blood coagulation and fibrinolysis, as well as to changes in platelet function. In the present study in vitro platelet aggregation, in addition to clotting activity, has been studied in 20 patients with chronic obstructive pulmonary disease and different degrees of alteration of blood gas analysis. The results obtained suggest that the presence of a condition of platelet hypoaggregability characterizes patients with marked hypercapnia and/or hypoxemia, whereas the improvement of respiratory indexes is followed by a trend to normalization, or, more often, to an increase of platelet activity.

Circadian variations in platelet aggregability in non insulin dependent diabetes patients (NIDDM).

Circadian rhythms of platelet activity have been extensively investigated in recent years in view of a possible correlation with the increased morning frequency of thrombotic events. Since a role of enhanced platelet activity has been suggested in diabetic macro- and microvascular disease, the aim of the present study was to analyze the circadian variations of in vitro platelet aggregability in patients with non insulin-dependent diabetes mellitus. Eighteen in-patients, ranging in age from 49 to 73 years, all in good metabolic control, were included in the study.

Differential platelet proaggregating activity of three Burkitt's lymphoma-derived human cell lines.

We demonstrate a differential platelet in vitro proaggregating activity in three Burkitt's lymphoma--derived human B cell lines, i.e. Daudi, Raji and P3H-R1.

Blood cellular and biochemical changes after extracorporeal shock wave lithotripsy.

The present study deals with blood cell behaviour and related hematochemical changes occurring in man after exposure to extracorporeal shock wave lithotripsy (ESWL). The following parameters have been investigated, before and after treatment, in a longitudinal study carried out on 58 patients of our Center: RBC count, Ht, Blood Hb, Plasma Hb, autohemolysis after 72 hours, bilirubinemia, WBC count, platelet count, in vitro platelet aggregation, beta-TG, sideremia and urinary post-exposure transferrin concentration. After exposure to ESWL, with pulse numbers ranging from 350 to 3,000, 18-20 KV, direct and indirect evidences of hemolysis have been found when number of SW exceeded 1,000.