Miyawaky et al. have identified recently a new prothrombin gene mutation c.1787G>T in a Japanese family with hereditary thrombophilia [4]. This mutation is located in the last exon of the prothrombin gene resulting in Arg596Leu replacement. Djordjevic et al. [5] also have described another mutation at the same prothrombin gene position (c. 1787G>A prothrombin Belgrade) that results in aminoacid...

The antithrombin III (AT III) concentration in plasma was measured in 63 patients on oral anticoagulant treatment (mean age 57.7 years), 26 healthy laboratory controls (mean age 28 years), and 21 patients attending the hypertensive clinic who had never been on oral anticoagulants (mean age 50 years). Three methods were used to measure AT III: a coagulation assay, a chromogenic substrate assay, ...

Observational studies usually agree with randomised, controlled trials. It is a logical fallacy, however, to suggest that agreement in one direction implies prediction in the other direction. Observational studies are not scientifically capable of proving or disproving hypotheses such as the efficacy and safety of the treatment of severe sepsis with antithrombin. Observational studies are diffi...

BACKGROUND The degree to which antithrombotic drugs suppress thrombin generation is unknown. Because hirudin, unlike antithrombin III, binds intravascular thrombin rapidly and selectively to yield a circulating inactive complex of 3- to 4-hour half-life, we used intravenous hirudin in humans to investigate the course of thrombin generation during and early after anticoagulation with this potent...

Activation of factor X by both the unactivated tissue factor:factor VII complex (TF:VII) and the activated tissue factor:factor VIIa complex (TF:VIIa) has been studied in the presence of tissue factor pathway inhibitor (TFPI), antithrombin III (ATIII), and heparin. At near-plasma concentrations of TFPI, ATIII, and factor X, factor X activation that occurs in response to TF:VII is essentially ab...

Plasma antithrombin activity was measured using an amidolytic method (substrate Chromozym TH) and a clotting method. The mean antithrombin values found in 76 hospital outpatients were 9.4 micronmol/min/ml with the amidolytic procedure and 100.1% of antithrombin activity with the clotting procedure. The two methods correlate fairly well (r = 0.85, P less than 0.01) and show satisfactory reproduc...

The heparin-enhanced antithrombin III/thrombin reaction was studied under a variety of conditions designed to determine the validity of kinetic models for the mechanism of action of heparin. The observed second order rate constant k& values for thrombin inhibition by antithrombin I11 were determined as a function of heparin concentration in the presence and absence of varying amounts of active ...

The distribution of heparin between thrombin and antithrombin III in solutions containing both proteins has been calculated using a heparin-thrombin dissociation constant value, KgssMT, of 1.5 X lo-’ M and a heparin-antithrombin III dissociation constant value, KEgsMAT, of 2.0 x lo-’ M. The enhancing effect of heparin on the antithrombin III/thrombin reaction rate appeared to correlate with the...