objective(s): haemostasis prevents blood loss following vascular injury. it depends on the unique concert of events involving platelets and specific blood proteins, known as coagulation factors. the clotting system requires precise regulation and coordinated reactions to maintain the integrity of the vasculature. clotting insufficiency mostly occurs due to genetically inherited coagulation fact...

Drummond, Margaret C. (Emory University, Atlanta, Ga.) and Morris Tager. Enzymatic activities associated with clotting of fibrinogen by staphylocoagulase and coagulase-reacting factor and their inhibition by diisopropylfluorophosphate. J. Bacteriol. 83:975-980. 1962.-The chemical mechanism of fibrinogen clotting by staphylocoagulase and its plasma factor (CRF) involves a preliminary stage of pr...

A mathematical model has been proposed to study the effect of [TAME] esterase on blood clotting time. Using this model, clotting time was found to decrease by 30% with increasing plasma [TAME] esterase activity in a group of smokers. It is hypothesized that [TAME] esterase through its effect on Hageman factor could affect clotting time. However mechanism of clotting by [TAME] esterase remains t...

Factor IX is a vitamin K-dependent blood clotting zymogen that is functionally defective or absent in patients with hemophilia B. A method of immunoaffinity chromatography has been developed for a one-step high yield purification of factor IX directly from plasma. The technique utilizes conformation-specific antibodies that bind solely to the metal-stabilized factor IX conformer, but not to the...

Interactions between standard heparin and the physiological anticoagulant plasma protein, activated protein C (APC) were studied. The ability of heparin to prolong the activated partial thromboplastin time and the factor Xa- one-stage clotting time of normal plasma was markedly enhanced by addition of purified APC to the assays. Experiments using purified clotting factors showed that heparin en...

The differential diagnosis of a long APTT with a normal prothrombin time can be due to either a clotting factor deficiency or the presence of an inhibitor, which can be distinguished by using a plasma-mixing study. The various clotting factor deficiency states are reviewed. Clinical bleeding following cardiac bypass surgery due to acquired factor V and thrombin antibodies is also reviewed.

We report the case of a 56-year-old female who presented with symptomatic paroxysmal atrial fibrillation. Anamnestic heparin-induced thrombocytopenia (HIT) type II was suspected, and a rapid diagnostic test showed antibodies against platelet factor 4. The heparin-induced platelet activation-assay was negative. Radiofrequency pulmonary vein isolation with intraprocedural anticoagulation using bi...