Evolution of a Prothrombin Conversion Accelerator in Stored Human Plasma and Prothrobin Fractions

Congenital Spca Deficiency: A Hitherto Unrecognized Coagulation Defect With Hemorrhage Rectified by Serum and Serum Fractions 1

“…When, however, determinations are made by the modified procedure in which the aged plasma is diluted with fresh BaSO4 plasma, the stored plasma shows increased prothrombic activity. Such "hyperactivity" also develops in aging prothrombin fractions obtained by BaSO, adsorption, and elution with citrate (14). This is attributable to evolution of a prothrombin conversion accelerator, which because of its resemblance to spca with regard to activity, stability and adsorbability by BaSO4, has been identified with spca.…”

“…prothrombic activity, as measured by the orthodox one-stage method, decreases during storage because of deterioration of L. F. (12,14,18). When, however, determinations are made by the modified procedure in which the aged plasma is diluted with fresh BaSO4 plasma, the stored plasma shows increased prothrombic activity.…”

“…Preparations of prothrombin were obtained from plasma by adsorption with BaSO, and elution with 5% solutions of sodium citrate in physiological saline, as described in earlier reports (14,8). Purified spca was similarly prepared from serum according to published methods (8).…”

The Prothrombin Conversion Accelerator of Serum (Spca): Its Partial Purification and Its Properties Compared With Serum Ac-Globulin 1

“…The latter is a plasma component, is labile and is not readily adsorbed by BaSO4 or BaCO3 whereas spca is a serum factor which is relatively stable and which is adsorbed by these substances. It arises from an inert and as yet unidentified plasma precursor which, together with prothrombin, is also adsorbable by BaSO4 and elutable by citrate (32). Both plasma Ac-globulin and spca, and perhaps the precursor of spca, are adsorbed by Mg(OH)2, appearing in fractions separated by this adsorbing agent.…”

On the Comparative Prothrombic Activity of Human and Dog Blood 1

“…The product considered to be the accelerator contains rise increases an undetermined amount of prothrombin. Alexresumably be-ander and Landwehr's (17) finding that the evoluianged to ac-tion of spca during storage is small in various hyound that the poprothrombic states might well be explained by for maximum a low concentration of prothrombin in the accelerprothrombin ator preparation. To determine how much of the *othrombin is activity is due to prothrombin and how much to ritamin K de-an accelerator becomes not only a formidable but lent decreases.…”