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Platelet Function Analyser (platelet + function_analyser)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

The role of the platelet function analyser (PFA-100TM) in the characterization of patients with von Willebrand's disease and its relationships with von Willebrand factor and the ABO blood group

HAEMOPHILIA, Issue 3 2003
I. C. Nitu-Whalley
Summary. Determination of the closure time (CT) with the platelet function analyser (PFA-100TM) is a useful screening test for von Willebrand's disease (VWD) but its role in the characterization of VWD is not well established. We studied the relationship between the prolongation of the CT with adenosine diphosphate (ADP) (CT-ADP) and epinephrine (CT-EPI) cartridges and the von Willebrand factor (VWF) in 53 patients with VWD. We found that a relatively small percentage of the prolongation of the CT-ADR and CT-ADP (16 and 29%, respectively) was determined by a reduction in VWF levels. The CT-ADP was significantly more prolonged in the presence of qualitative defects in VWF but could not discriminate between the VWD subtypes. The ABO blood group had no effect on the prolongation of the CT or the bleeding time. In conclusion, the PFA-100TM appears of little use in the characterization of severity and subtype of VWD. [source]

Platelet concentrates transfusion in cardiac surgery and platelet function assessment by multiple electrode aggregometry

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009
N. RAHE-MEYER
Background: Platelet dysfunction contributes to the pathophysiology of bleeding complications during and after cardiac surgery. In most surgical institutions, no peri-operative point-of-care monitoring of platelet function is used. We evaluated the usefulness of the Multiplate® platelet function analyser based on impedance aggregometry for identifying groups of patients at a high risk of transfusion of platelet concentrates (PC). Methods: Platelet function parameters were determined in 60 patients before and after routine cardiac surgery. Impedance aggregometry measurements were performed on Multiplate® using ADP (ADPtest), collagen (COLtest) and thrombin receptor activating peptide (TRAPtest) as platelet activators. The correlations between the aggregometry results and the transfusion of PC were calculated. The results of the aggregation tests were also divided into tertiles and the differences in PC transfusion between the low and the high tertile were assessed. Results: Low aggregometry delimited groups of patients with significantly higher PC transfusion. In the receiver operating characteristic curve, low pre-operative aggregation in the ADPtest identified patients with high total transfusion of PC (area under the curve 0.74, P=0.001), while the ADPtest performed at the end of the operation identified patients with high PC transfusion on the intensive care unit (ICU) (area under the curve 0.76, P=0.002). Conclusions: Near-patient platelet aggregation may allow the identification of patients with enhanced risk of PC transfusion, both pre-operatively and upon arrival on the ICU. [source]

Pharmacological Profile and Therapeutic Potential of BM-573, a Combined Thromboxane Receptor Antagonist and Synthase Inhibitor

CARDIOVASCULAR THERAPEUTICS, Issue 1 2005
Alexandre Ghuysen
ABSTRACT BM-573 (N-terbutyl-N,-[2-(4,-methylphenylamino)-5-nitro-benzenesulfonyl]urea), a torsemide derivative, is a novel non-carboxylic dual TXA2 synthase inhibitor and receptor antagonist. The pharmacological profile of the drug is characterized by a higher affinity for the thromboxane receptor than that of SQ-29548, one of the most powerful antagonists described to date, by a complete prevention of human platelet aggregation induced by arachidonic acid at a lower dose than either torsemide or sulotroban, and by a significantly prolonged closure time measured by the platelet function analyser (PFA-100®). Moreover, at the concentrations of 1 and 10 ,M, BM-573 completely prevented production of TXB2 by human platelets activated by 0.6 mM of arachidonic acid. BM-573 prevents rat fundus contraction induced by U-46619 but not by prostacyclin or other prostaglandins. Despite possessing a chemical structure very similar to that of a diuretic torsemide, BM-573 has no diuretic activity. BM-573 does not prolong bleeding time and, unlike some of the other sulfonylureas, has no effect on blood glucose levels. In vivo, BM-573 appears to have antiplatelet and antithrombotic activities since it reduced thrombus weight and prolonged the time to abdominal aorta occlusion induced by ferric chloride. BM-573 also relaxed rat aorta and guinea pig trachea precontracted with U-46619. In pigs, BM-573 completely antagonized pulmonary hypertensive effects of U-46619 and reduced the early phase of pulmonary hypertension in models of endotoxic shock and pulmonary embolism. Finally, BM-573 protected pigs from myocardial infarction induced by coronary thrombosis. These results suggest that BM-573 should be viewed as a promising therapeutic agent in the treatment of pulmonary hypertension and syndromes associated with platelet activation. [source]