ASSAY PRINCIPLE: The method is a clotting assay where all the clotting factors are present (constant and in excess, brought by the deficient plasma), excepted for FII, which is brought by the diluted tested plasma, and clotting is triggered with calcium thromboplastin. FII is the limiting factor and clotting time is inversely proportional to the concentration of FII. There is an inverse linear ...

Monitoring of direct thrombin inhibitors with the activated partial thromboplastin time (aPTT) is limited by poor linearity and reproducibility. Recently, direct prothrombin activation methods have been developed for coagulation analysis: ecarin clotting time (ECT) and prothrombinase-induced clotting time (PiCT). Laboratory monitoring of the direct thrombin inhibitors lepirudin, argatroban, and...

The aim of this study was to examine the effect of estrogen on fibrinogen clotting time in rabbit model experimentally. The study was performed on 14 white New Zealand race female prepubertary rabbits at two months old weighing meanly 1.4±0.3 kg. Blood samples was taken from ear veins of the rabbits and first fibrinogen clotting time levels were measured to obtain control values. Next day, fema...

The process of human blood clotting involves a complex interaction of continuous-time/continuous-state processes and discrete-event/discrete-state phenomena, where the former comprise the various chemical rate equations and the latter comprise both threshold-limited behaviors and binary states (presence/absence of a chemical). Whereas previous blood-clotting models used only continuous dynamics...

OBJECTIVE To investigate the effect of tris-hydroxymethylaminomethane (THAM) pH neutralization on reversing coagulation abnormalities caused by acidosis. DESIGN Random and controlled study. SETTING Animal research facility and laboratory. SUBJECTS Yorkshire swine (n = 18). INTERVENTIONS Acidosis was induced in 12 pigs by infusing 0.2 M hydrochloric acid (HCl). When the target pH of 7.1 ...

Our aim was to establish whether differences in clotting times for recalcified blood and plasma samples might be explained by the use of different blood collection tubes. Samples obtained from different plastic vacuum tubes were recalcified and clotting times determined by free oscillation rheometry. The clotting times for blood collected in Vacutainer (Becton Dickinson, Rutherford, New Jersey,...

The clinical usefulness of a chromogenic method for prothrombin time (PT) determination has been assessed in a wide range of clinical conditions, and it is compared with the conventional clotting method for PT. The new method appears to be as sensitive as the clotting PT to deficiencies of clotting factors of the extrinsic and common pathway, except for fibrinogen. Patients with proven liver di...