By SAMUEL I. RAPAPORT, KNIJT AAS ANI) PAUL A. OWREN T HE DE1\IONSTRATION of the thromboplastin-hike activity of Russell viper venom by Macfarlane and Barnett’ was followed by its use in some laboratories as a substitute for brain thromboplastin in “prothrombin time” determinations. However, it gradually became apparemit that there were importamit differences between the ‘thromboplastic” activit...

We describe here a test for lupus anticoagulants based on a modified Russell viper venom time (RVVT). using limiting amounts of phospholipid and venom. We have studied 29 patients with a prolonged dilute RVVT. Five of the 29 had a normal activated partial thromboplastin time and three of 1 4 tested by the tissue thromboplastin inhibition test were normal. In 1 7 of 1 9 patients tested. the dilu...

p-Nitrophenyl-p’-guanidinobenzoate is a suitable substrate for the titration of purified bovine Factor X which has been activated by a coagulant protein from Russell’s viper venom. Reaction of Factor Xa with p-nitrophenyl-P’-guanidinobenzoate occurs at the site which is responsible for the clotting activity of Factor Xa. Activation of bovine Factor X by the Russell’s viper venom coagulant prote...

We describe the effect of pH and NaCl concentration on the activation of factor X in plasma by Russell's viper venom and on the amidolytic activity of the activated enzyme towards factor Xa-sensitive chromogenic substrates. An increasing NaCl concentration results in a decrease in the activation rate of factor X by Russell's viper venom, whereas in this step no pH effect is observed. Increasing...

A heat-stable humoral substance (coagulopoietin-X) is present in rabbits partially depleted of Factor X, which is capable of raising Factor X levels when injected into recipient rabbits. Rabbits were partially depleted of Factor X by slow infusion of a globulin fraction of goat anti-rabbit Factor X antibody. This resulted in the reduction of Factor X to 40--50% of normal at 1 h and 60--70% of n...

The venom of Pakistan species of snakes (Naja naja, Vipera russelli and Echis carinatus) and lethal fractions of Cobra (Naja naja) venom were converted to toxoid with formalin. Detoxification of the crude venoms and toxic fraction was attained by addition of formalin in several steps and incubation at 37°C maintaining the pH 7.0. Relationship of formalin concentration and incubation period was ...

p-Nitrophenyl-p’-guanidinobenzoate is a suitable substrate for the titration of purified bovine Factor X which has been activated by a coagulant protein from Russell’s viper venom. Reaction of Factor Xa with p-nitrophenyl-P’-guanidinobenzoate occurs at the site which is responsible for the clotting activity of Factor Xa. Activation of bovine Factor X by the Russell’s viper venom coagulant prote...

Colonel Chopra and Captain Chowhan was Pu^, ujte It is mentioned in the article that .'viper. ^ prevents clotting of blood, thus encouraging oozM=> blood from the nose, vagina and stools, etc. nl It is not clear to me why this same viper ve oV is successfully employed in cases of haemophilia *-0f bleeders, and allied diseases where the coagulability blood is delayed or prevented. ure In other w...

Advances in the last decade combining transcriptomics with established proteomics methods have made possible rapid identification and quantification of protein families in snake venoms. Although over 100 studies have been published, the value of this information is increased when it is collated, allowing rapid assimilation and evaluation of evolutionary trends, geographical variation, and possi...