Inhibition of human platelet function by parsalmide.

2-Propargyloxy-5-amino-N-butyl-benzamide (parsalmide), an antiinflammatory drug, inhibits human platelet function in vitro and ex vivo. The degree of inhibition of ADP- and collagen-induced platelet aggregation "in vitro" is dose-dependent and parsalmide shows a more marked effect than equal concentrations of acetylsalicylic acid (ASA) and indometacin. Moreover, malondialdehyde levels in human PRP after addition of thrombin were inhibited at the same degree by parsalmide, ASA and indometacin.

Thrombolytic therapy for venous thrombosis in patients with gastro-intestinal diseases.

Venous thrombosis in 2 patients with gastro-intestinal diseases (chronic liver disease and ulcerative colitis) is reported. A good clinical improvement was obtained after thrombolytic (urokinase) therapy without any haemorrhagic side-effect. A decrease in the plasma of the fast-acting antiplasmin has been correlated with urokinase thrombolytic effect in vivo.

Beta-thromboglobulin and platelet factor 4 plasma levels during haemodialysis: effect of indobufen.

The effect of a single dose of indobufen (100 mg i.v.) on the release of beta-thromboglobulin and of the platelet factor 4 was investigated during dialysis in 20 uraemic subjects by a within-subjects, single-blind, indobufen versus placebo study.

GAGs-potentiated inhibition of thrombin, factor Xa and plasmin in plasma and in a purified system containing antithrombin III - correlation with total charge density.

The ability of heparin and related glycosaminoglycans (GAGs) to accelerate the inhibition of thrombin, factor Xa and plasmin in plasma and in a purified system containing antithrombin III (At III) was studied using chromogenic peptide substrate assays. There was good correlation between the charge density of the mucopolysaccharides and the activities investigated. While the difference between potentiation of the antithrombin activity by GAGs in plasma and in the purified system was slight, the inhibition of factor Xa in plasma was more pronounced than in the presence of purified At III, indicating the mechanisms for GAGs-potentiated inhibition of thrombin and factor Xa are not identical.

Daunorubicin and platelet function.

The influence of Daunorubicin on some platelet functions in vitro was investigated, using different concentrations of the drug (0.01-0.02-0.

Pharmacokinetic, bioavailability and pharmacodynamic study of indobufen (K 3920), an inhibitor of platelet aggregation, after a single dose in man.

Six healthy volunteers received single iv and oral doses of 2-[p-(1-oxo-2-isoindolinyl)phenyl] butyric acid 100 mg (indobufen; K 3920), an inhibitor of platelet aggregation. Plasma levels and urinary excretion of the drug were determined by GLC. Collagen-induced platelet aggregation was assessed turbidimetrically at various intervals after administration.

[Interaction between anti-aggregating and anticoagulant agents. A double blind study on the concomitant administration of nicergoline and acenocoumarols].

A double blind study was carried out comparing 10-methoxy-1,6-dimethyl-ergoline-8 beta-methanol-(5-bromonicotinate) (nicergoline, Sermion) and placebo in 60 thromboembolic patients on long-term controlled acenocoumarol treatment. Aim of the trial was to assess the hypothesis of an interaction on both the coagulatory parameters and the clinical findings. No significant variations of the acenocoumarol daily dose were required in nicergoline treated group and no interaction was demonstrated in coagulatory parameters.

Anti-heparin activity of a macroglobulin from a patient with breast adenocarcinoma.

We describe a case of IgM paraproteinemia, whose macroblogulin reacted anomalously with heparin. Anti-heparin activity of the paraprotein was suggested by insensibility of the patient's plasma to heparin in heparin-thrombin clotting time. Moreover, the presence of heparin in the medium markedly reduced the inhibitory effect of the paraprotein on platelet aggregation by ADP.

Human platelet aggregation by mixed cryoglobulins.

Glomerulonephritis in idiopatic mixed cryoglobulinemia represents perhaps a glomerular damage by immune complexes. In this study, a sigmoidal-like curve was obtained after addition of 13 different mixed cryoglobulins to both autologous and isologous platelet-rich plasma, tested in platelet aggregometer. The lag phase of the curve corresponds to platelet phagocytosis of cryoglobulin-binding ferritin, as shown in electron microscopy and the optical density decrease phase corresponds to the aggregation of platelets that shows the same ultrastructural characteristics of ADP-induced platelet aggregation.

Platelet aggregometry and anti-platelet isoantibodies.

102 sera from polytransfused patients have been screened in platelet aggregometry. Anti-human platelet isoantibodies, tested against 'responsive' human platelets in PRP, give in the aggregometer a decrease in optical density recorded as a sigmoidal curve. In the first step of reaction PF3 availability suggests that the primary action of antibody is to damage the platelet membrane.