The marginal zone, in pregastrulating chick blastoderms, has been defined as the intermediate ring between the epiblast proper and the most external region, the area opaca (Spratt & Haas, 1960). Azar & Eyal-Giladi (1979) have shown that the marginal zone of a stage XIII blastoderm has the capacity of regenerating an inductive layer which when in contact with a competent stage XIII epiblast can ...

We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control stud...

Factor XIII is a blood protransglutaminase that is distributed in plasma and platelets. The extracellular and intracellular zymogenic forms differ in that the plasma zymogen contains A and B subunits, while the platelet zymogen has A subunits only. Both zymogens form the same enzyme. Erythrocytes, in contrast, contain a tissue transglutaminase that is distinct from Factor XIII. In this study ot...

A 57-year-old man presented with a spontaneous upper-extremity hematoma and compartment syndrome. The patient experienced excessive bleeding following evacuation of the hematoma, and the results of routine coagulation studies were normal. Factor XIII activity was undetectable using a photometric assay, and the presence of an inhibitor was detected with mixing studies. Bleeding was controlled wi...

Fibrin polymers (des A,B fibrinogen) reduced the concentration of a-thrombin required for 50% activation of plasma factor XIII (a2b2 tetramer) by approximately 1 00-fold. In the presence of fibrin, the amount of ‘y-thrombin required for activation was not affected. Catalytically inactive i-Pr2Pand D-Phe-PrO-Arg-CH2-a-thrOmbin were found to inhibit over 95% of the activation by a-thrombin in the...

Twenty-five years ago, a groundbreaking paper from Tsukuba University in Japan was published, identifying the sequence of the endothelin gene and peptide (Nature 332, 411-415, 1988). This work opened the way for the discovery of the endothelin receptors and the development of orally active endothelin receptor antagonists (ERAs). Today, ERAs are part of medical therapy of patients around the wor...