The effect of activated human platelets in intrinsic factor X activation was compared with their effect in prothrombin activation. Compared with unstimulated platelets, platelets triggered by the combined action of collagen plus thrombin showed a tenfold activity increase in prothrombin activation, and a 20-fold rate enhancement in factor X activation. Treatment of collagen plus thrombin-stimul...

The blood-clotting protein prothrombin can be converted to thrombin in free solution by the proteolytic enzyme, activated factor X. When prothrombin is bound to the surface of phospholipid vesicles, the rate of thrombin generation is increased more than 30-fold over the rate of unbound prothrombin. If the prothrombin activation process is terminated after a time interval in which less than 10% ...

We determined whether total hip arthroplasty (THA) patients could test their own prothrombin time reliably over 6 weeks of anticoagulation prophylaxis with a portable device that measures prothrombin time and whether self-testing would improve or maintain the quality of care at a lower cost than our standard procedure. Forty-six THA patients participated in the study and were compared with a ma...

AIM To assess the reliability of local international normalised ratios (INR) using a set of three international reference preparation (IRP) certified freeze dried plasmas. METHODS 55 centres in the United Kingdom and the Republic of Ireland participated; 36 centres employed coagulometers and 19 a manual prothrombin time technique, all with the same batch of routine commercial thromboplastin. ...

\\TIDESPREAD use of oral anticoagulant thei’apy has made prothrombin time one of the most frequently requested determinations in the clinical laboratory. In order to maintain clinical safety and the effectiveness of anticoagulants it is imperative that a pi’ocedui’e be employed which is maximally reliable almd reproducible, amid which permits as little variation jim individual technic as possib...

Formation of thrombin during incubation of purified bovine prothrombin with purified staphylococcal metalloprotease has been investigated. Thrombin activity was estimated by examination of clotting time and by digestion of a synthetic substrate, Chromozym TH. The metalloprotease caused direct activation of prothrombin which was inhibited by the addition of ethylenediaminetetraacetic acid. Metal...

Haemostasis is the process of forming clots in the walls of damaged blood vessels to prevent abnormal bleeding and to maintain intravascular blood in a fluid state. Fenugreek is largely universal staple herb, popular throughout history and it has been consumed for treatment of different disorders. We aimed to study the possible anticoagulant effect of Fenugreek aqueous extract in vitro by using...

Anticoagulant activity of acenocoumarin (Sintrcm) has been determined in dogs, Prothrombin values were determined according to modified Quick's method (Montigel 1962). Prothrombin index and coagulation valency were deduced from the prothrombin time. The results were compared with the reference drug ethylbiscoumacetate. Acenocoumarin was found to be 60 times more potent than ethylbiscoumacetate....

AIMS An open, controlled, randomized, crossover study was conducted in healthy males to assess the possible occurrence of a pharmacokinetic/pharmacodynamic interaction between warfarin and the selective serotonin re-uptake inhibitor citalopram. METHODS Twelve subjects received a single 25 mg dose of racemic warfarin either alone or on Day 15 of a 21-day oral dosing regimen of 40 mg citalopram...