Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0149871 (deep vein thrombosis)
 12,364 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanisms of action of three most commonly used antiplatelet agents (aspirin, sulfinpyrazone, dipyridamole) are briefly discussed. Aspirin inhibits the prostaglandin synthetase of platelets irreversibly and thereby blocks the production of prostaglandin endoperoxides and thromboxane A2, which stimulate platelet aggregation. A daily aspirin dose of 200--300 mg is sufficient to achieve this effect. Sulfinpyrazone appears to interfere with the adhesion of platelets to subendothelial structures and atherosclerotic plaques. Dipyridamole increases cyclic AMP in platelets and thus reduces platelet response to aggregating agents. A few of the satisfactorily performed studies on the clinical effectiveness of antiplatelet agents are mentioned. Sulfinpyrazone treatment of patients with myocardial infarction (Killip--classification I and II), starting 25--35 days after the acute myocardial infarction, reduces cardiac mortality and incidence of sudden death for a period of two years. The efficacy of aspirin treatment in coronary artery disease is not yet definitely established. In patients with transient ischemic attacks, particularly males with appropriate carotid lesions, aspirin therapy reduces the frequency of transient ischemic attacks and possibly the incidence of stroke and death. Sulfinpyrazone is ineffective in these patients. Sulfinpyrazone and aspirin are of value in the prevention of thrombosis in straight arterio-venous shunts. Aspirin reduces the frequency of deep venous thrombosis after total hip replacement in males but not in females. In patients with recurrent venous thrombosis, sulfinpyrazone treatment is effective in preventing thrombosis.
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PMID:[Action mechanism and clinical indications for thrombocyte aggregation inhibitors]. 42 7

Defibrotide, a deoxypolyribonuclide, has been found to modulate endothelial cell function causing increase in t-PA and decrease in PAI levels and also increase in PGI2 production. In addition, it increases platelet c-AMP levels and decreases MDA and TXB2 formation in human. Defibrotide inhibits platelet aggregate formation in vitro experiments as well as end-to-end anostomosis in rats. So, defibrotide inhibits the activation of platelets. Besides an increase of protein C and S levels a synergic action of heparin was observed in animal experiments. A strong antithrombotic effect has been observed in animal models. The drug has a beneficial effect in the cases of DVT, POVD, stroke and thromboembolism. Through its action we may say that the drug acts in a novel fashion in contrast to the other drugs used in this area. Defibrotide is a single-stranded polydeoxyribonucleotide obtained from deoxyribonucleic acid of mammalian lungs by controlled depolimerization. Since 1981 in our laboratory and in the clinical department we have been investigating a newly developed agent defibrotide in vitro experiments, animal experiments, and also its clinical pharmacology and clinical application. Some of our findings are already published and compared with literature (40, 43, 46). Because of the limited space we are not going to review the literature in detail but we are going to summarize our observations on this compound in the following order. I--in vitro experiments, II--Animal experiments, III--clinical pharmacology in human.
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PMID:The pharmacology and clinical pharmacology of defibrotide: a new profibrinolytic, antithrombotic and anti-platelet substance. 210 24

Defibrotide, a polydeoxyribonucleotide, has been found to modulate endothelial cell function, causing an increase in tissue plasminogen activator (t-PA) levels, a decrease in plasminogen activator inhibitor (PAI) levels, and an increase in prostaglandin I2 (PGI2) formation in humans. Defibrotide has no direct anticoagulant effect but has a synergistic action with heparin. A strong antithrombotic effect has been observed in animal models. Thus, defibrotide has a beneficial effect in cases of deep venous thrombosis (DVT), peripheral obliterative vascular disorder (POVD), stroke, vasculitis, and thromboembolism. Defibrotide also inhibits platelet function and activation. A significant decrease in platelet aggregate formation on the suture line in microarterial anastomosis in rats is one way defibrotide can inhibit platelet function and activation. In humans, a slight prolongation' of the lag period in collagen-induced aggregation has been observed. In addition, a slight decrease in the maximum amplitude of the secondary wave of ADP and adrenalin-induced aggregations was also found. Platelet adhesion is diminished, the platelet differential count on formvar membrane is altered, and platelet aggregate formation is significantly inhibited. With an increase in platelet cyclic AMP (cAMP) content and a decrease in malonyl dialdehyde (MDA) and thromboxane B2 (TXB2) formation, the levels of platelet secretion products such as PF-4 and beta-thromboglobulin (beta-TG) in plasma decreased progressively. It was also demonstrated that the 14C-glucose transport defect of the platelet membrane of atherosclerotic patients was partially corrected with defibrotide treatment.
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PMID:Effect of defibrotide on platelet function. 880 24