Experimental hypercalcaemia was induced in rats by (1) transplantation of the solid Walker 256 tumour, and (2) intraperitoneal injections of calcium gluconate. Whole blood clotting was studied by means of thromboelastography and whole blood clotting times in polystyrene and glass test tubes. At serum calcium levels between 10.3 and 11.5 m-equiv/l a slight delay in clot formation was found which...

A study of blood coagulation was made on cardiac patients with and without acute myocardial infarction, prior to anticoagulant therapy. The heparin clotting time, an in vitro modification of the heparin tolerance test, was accelerated in 74 per cent (14 out of 19) of the patients with acute myocardial infarction studied within three weeks after the attack. One out of 14 patients without acute m...

Increasing clinical experience has gradually diminished the number of laboratory tests required for monitoring thrombolytic therapy. Still wider and wider use of plasminogen activators, often without a specialized laboratory basis, makes it imperative that some easily performed and reproducible tests should be at our disposal. Such conditions seem to be fulfilled by a simple assay of plasma clo...

Remarkably, American black bears (Ursus americanus) are capable of varying their heart rates to coincide with their breathing, creating pauses of 30 s or more, yet they do not appear to suffer from embolic events. We evaluated some features of the clotting cascade of black bears, providing novel insights into the underlying mechanisms they evoke for embolic protection during hibernation. We mea...

A wide range of factor VIII and IX levels is observed in heterozygous carriers of hemophilia as well as in noncarriers. In female carriers, extreme lyonization may lead to low clotting factor levels. We studied the effect of heterozygous hemophilia carriership on the occurrence of bleeding symptoms. A postal survey was performed among most of the women who were tested for carriership of hemophi...

When human prothrombin is activated in 25 % (weight per volume) sodium citrate, the apparent clotting and esterase activities of thrombin develop at equal rates and reach maximum levels in about 16 hours. Following this, the esterase activity remains stable, but over 90% of the fibrinogen-clotting activity disappears from the system during the next 500 hours. Chromatography of the 16-hour syste...

The evolution of care in hemophilia is a remarkable story. Over the last 60 years, advances in protein purification, protein chemistry, donor screening, viral inactivation, gene sequencing, gene cloning, and recombinant protein production have dramatically enhanced the treatment and lives of patients with hemophilia. Recent efforts have produced enhanced half-life (EHL) clotting factors to bett...

Blood clotting was examined in 24 consecutive full-term newborn infants with hypoxia and 23 normal control infants. There was evidence of a gross alteration in the clotting process in the hypoxic infants. The degree of disturbance in clotting seemed to be dependent on the severity of the hypoxia, suggesting a causal relationship. The mechanism involved seemed to be intravascular coagulation. Th...