Search results for "Platelet Aggregation"

ABNORMALLY HIGH THROMBOXANE BIOSYNTHESIS IN HOMOZYGOUS HOMOCYSTINURIA. EVIDENCE FOR PLATELET INVOLVEMENT AND PROBUCOL-SENSITIVE MECHANISM.

1993

Homocystinuria due to homozygous cystathionine beta-synthase deficiency is an inborn error of metabolism characterized by a high incidence of thrombosis and premature atherosclerosis. We evaluated TXA2 biosynthesis in vivo and several in vitro tests of platelet function in 11 homocystinuric patients and 12 healthy controls. In vitro, patients' platelet aggregation was within control values as were TXB2 formation, fibrinogen binding, and ATP secretion in response to thrombin. In contrast, the urinary excretion of 11-dehydro-TXB2, a major enzymatic derivative of TXA2, was > 2 SD of controls in all patients (1,724 +/- 828 pg/mg creatinine, mean +/- SD, in patients vs. 345 +/- 136 in controls, …

Platelet-activating factor type activity in plasma from patients with septicemia and other diseases

1991

The purpose of the present study was to determine whether increased levels of platelet-activating factor (PAF) type activity can be detected in plasma from patients with septicemia and other diseases. A level of PAF below 0.5 ng/mL of plasma was considered normal. We found that plasma from a patient with adverse anaphylactoidic reaction to intravenous analgetics contained 2.1 ng PAF/mL. In seven patients with septicemia, including urosepsis, endocarditis and peritonitis, and with positive blood culture, increased plasma PAF levels (1-20 ng PAF/mL) were observed. Other patients with clinical indications of septicemia had negative blood cultures and/or increased levels of C-reactive protein (…

Inhibition of thromboxane biosynthesis and platelet function by simvastatin in type IIa hypercholesterolemia

1995

Abstract Thromboxane A 2 (TXA 2 ) biosynthesis is enhanced in the majority of patients with type IIa hypercholesterolemia. Because simvastatin (a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor) was previously shown to reduce platelet aggregation and TXB 2 production ex vivo, we investigated TXA 2 biosynthesis and platelet function in 24 patients with type IIa hypercholesterolemia randomized to receive in a double-blind fashion simvastatin (20 mg/d) or placebo for 3 months. The urinary excretion of 11-dehydro-TXB 2 , largely a reflection of platelet TXA 2 production in vivo, was measured by a previously validated radioimmunoassay technique. Blood lipid levels and urinary 11-dehyd…

Platelet aggregation, ATP release and cytoplasmic Ca2+ movement: the effects of cloricromene.

1994

A placebo-controlled, double-blind, randomized, cross-over study was performed in 24 healthy volunteers. 12 volunteers received Cloricromene (100mg gastroresistant capsules twice a day) for 7 days, the other volunteers received identical placebo capsules. Subsequently, after a 7-day wash-out period, at day 15, each subject received the other treatment. Blood samples were taken on days 1 and 15 (1st day of each treatment) as well as on days 7 and 21 (7th day of each treatment) before the morning drug administration and 2 and 4 hours later. Platelet aggregation and ATP secretion were studied in whole blood (WB) using ADP and collagen as stimulating agents. Ca2+ fluxes were studied in aequorin…

Effects of hawthorn (Crataegus laevigata) on platelet aggregation in healthy volunteers

2011

Continuous intravenous infusion of dipyridamole as adjunctive therapy in the treatment of thrombotic thrombocytopenic purpura.

2003

Abstract Thrombotic thrombocytopenic purpura (TTP) is an uncommon hematologic thrombotic disorder characterized by fever, hemorrhagic and neurologic signs. The advent of plasma exchange has dramatically improved the prognosis of this disease, which was once inevitably fatal. However, mortality rates remain significant. Antiplatelet drugs have been widely used in combination with plasma exchange. In this pilot study we investigated the effects of an adjunctive therapy consisting of the continuous, intravenous infusion of dipyridamole, a modality of administration that has not been previously tested in this setting. Sixteen untreated TTP patients, diagnosed consecutively at our clinic, receiv…

Antiplatelet effects of intravenous iloprost in patients with peripheral arterial obliterative disease

1986

The dose-dependent inhibition of platelet aggregation by the chemically stable, prostacyclin-mimetic, iloprost, was studied in patients suffering from stage II-III peripheral arterial obliterative disease (PAOD). The study was designed as a randomized placebo-controlled cross-over trial. Iloprost was administered i.v. to six patients at doses of 0.5, 1.0, 2.0 or 3.0 ng/kg X min for 4 h, with an interval of 2-3 days between the infusions. During iloprost infusion, systolic and diastolic arterial blood pressure, heart rate and blood flow in the affected limb remained unchanged. In contrast, there was a considerable, dose-dependent inhibition of ADP- and thrombin-induced platelet aggregation a…

Dental extractions in patients on antiplatelet therapy. A study conducted by the Oral Health Department of the Navarre Health Service (Spain).

2008

Objectives: Antiplatelet drugs are used to treat and prevent a wide range of cardiovascular pathologies and/or cerebrovascular accidents. Although the use of anticoagulants in dental extractions is highly protocolized, a clear control method has not yet been established for antiplatelet drugs. This study is directed at evaluating the clinical consequences of extractions in patients on antiplatelet therapy. Study design: The Oral Health Department of the Navarre Health Service-Osasunbidea conducted a trial on 155 patients who underwent dental extractions and were receiving antiplatelet therapy. The patients were not requested to interrupt the medication and local measures were taken to contr…

Picotamide, a combined inhibitor of thromboxane A2 synthase and receptor, reduces 2-year mortality in diabetics with peripheral arterial disease: the…

2004

Aims Patients with diabetes are at excessive risk of mortality and cardiovascular morbidity. Previous studies suggest that aspirin may be less effective in diabetic patients. In this multi-centre, randomized, double blind trial picotamide, a dual inhibitor of thromboxane A2 synthase and receptor, was compared with aspirin for the prevention of mortality and major cardiovascular events in diabetics with peripheral arterial disease (PAD). Methods and results A total of 1209 adults aged 40–75 years with type 2 diabetes and PAD were randomized to receive picotamide (600 mg bid) or aspirin (320 mg od) for 24 months. The cumulative incidence of the 2 years overall mortality was significantly lowe…

Atherosclerosis and Cerebral Ischemic Attacks: Intakes of Cerebrography With Xenon133 Inhaled and Platelet Tests in the Diagnosis, Clinical and Thera…

1984

A study of patients to develop the significance of the role of the blood plate lets in the recurrence of transient cerebral ischemic attacks in patients with cerebral atheromatous, develop the effectiveness of dipyridamole in the prophy lactic therapeutic regimen. In the group treated with dipyridamole, a 76.3% clinical improvement was recorded (mean increases of 11.2 ml/min. and 11.4 ml/min. of the cerebral hemispheric flows), 15.8% of cases stabilized (mean increases of 1.7 ml/min. and 1.2 ml/min.) and 7.9% failures (mean decreases of 10.4 ml/min. and 14.3 ml/min.) of these same flows. The cerebrography with xenon 133 inhaled as well as the platelet tests used, constitute unfailing means…