Viper, Russell

X Umbilical cord, joint, and muscle bleeding Prolonged PT and aPTT Normal thrombin time Prolonged Russel s viper venom Specific factor X assay... 

Where the snake has been identified and specific antivenom is available, then this should be used. However, since treatment is urgent, and identification of snakes is difficult, in many Asian countries polyvalent antivenom is used. The Indian anti-snake venom (ASV), manufactured by Serum Institute India, Pune, and Haffkine Bio Pharmaceutical Corporation, Mumbai, consists of hyperimmune horse serum against four common snakes - cobra, common krait, Russell s viper and saw-scale viper. 

DiScipio RG, Hermodson MA, Davie EW. Activation of human factor X (Stuart factor) by a protease from Russell s viper venom. Biochemistry 1977 16 5253- 5260. 

There are a number of different procoagulant agents which had been used to induce thrombosis in this model, such as human serum, Russel viper venom,... 

Specific factor assays are variations on the APTT or PT tests. In the APTT and PT, dilutions of the patient s plasma are made into a deficient, or depleted, substrate plasma. The assays are then performed in the usual way. The clotting times are compared with those obtained from dilutions of pooled normal plasma, commonly 1 10, 1 20, 1 50, and 1 100. A graph of the logarithm of the clotting time (y axis) versus the logarithm of the concentration as percentage of normal x axis) is used to determine the amount of the factor activity in the patient s plasma. The normal pooled plasma is conventionally assigned a value of 100% activity. Many variations exist for specific factor assays, e.g., the venom of Vipera russellii and phospholipids may be substituted for thromboplastin in a PT-like assay. An enzyme in Russell s viper venom rapidly and relatively specifically activates factor X. In conjunction with a factor X-deficient substrate plasma, this provides a specific factor X assay. 

Takeya, H., Nishida, S., Miyata, T., Kawada, S., Saisaka, Y., Morita, T., and Iwanaga, S. (1992). Coagulation factor X activating enzyme from Russells viper venom (RVV-X). J. Biol Chem. 267 14109-14117. 

As with the case of prothrombin, Factor X can be activated by both physiological and nonphysiological activators. For substrate assays, both types of activators have been employed. An example of the former is the use of thromboplastin (A6, V5) an example of the latter is the employment of Russell s viper venom (RW) in the presence of calcium ions (Al, B7, V4). In general, the latter activator appears to be favored because it does not require phospholipids for activation hence thrombin generation is retarded (A6, Dl), and decarboxylated Factor X is not activated by RW. The most frequently used substrate has been S-2222, but S-2337, which has a lower K, may become more widely used (A8, 816). 

Protein C, like Factors II, VII, IX, and X, is a vitamin K-dependent protein. Activated protein C (PCa) can be derived by limited proteolysis of this zymogen by thrombin, trypsin, or by Russell s viper venom (VI). PCa, in contrast to the other vitamin K—activated ctors, exerts an anticoagulant activity by inhibiting Factors Va and Villa (Fll). A second activity identified for PCa is the release of plasminogen activator based on animal in vivo studies (CIO, Z2). These biochemical observations and the discovery of patients vnth recurrent thrombosis who are congenitally deficient in protein C make PCa a candidate for a central role in hemostasis (BIT). 

L12. Lindquist, P. A., Fujikawa, K., and Davie, E. W., Activation of bovine Factor IX (Christmas Factor) by Factor XI. (activated plasma thromboplastin antecedent) and a protease from Russell s viper venon. J. Biol. Chem. 253, 1902-1909 (1978). 

The effect of deglycosylation of bovine factor XI has been investigated with factor-X-activating enzyme from Russell s viper venom or extrinsic Xase (factor Vlla/tissue factor/phospholipid) by examining the activation rates of derivatives of factor X prepared using O-glycanase, sialidase, and/or N-glycanase [52]. The removal of 0-linked carbohydrate resulted in a decrease in the rate of activation. 

There is a bioreaction engineering home problem in virtually every chapter. Bio-related web modules include physiological-based-pharmacokinetic (PBPK) models of ethanol metabolism, of drug distribution, and of venomous snake bites by the Russels viper and the cobra. 

The injection of toxic agents such as compound 48/80 and Russel Viper Venom results in disruption of mast cells with shedding of granules. Higgin-... 

Page RC, de Beer EJ, Orr ML. Prothrombin studies using Russell viper venom, n. Relation of clotting time to prothrombin concentration in human plasma. JLab ClinMed ( 9AV) 27,197-201. 

This 23-hydroxylated derivative of deoxycholic acid has been detected as a component of the bile of certain snakes, especially of the family Vipe-ridae. Specifically the acid has been isolated from Bitis arietans, Bitis gabo-nica, and Russell s viper (4, 136). In these snakes, bitocholic acid occurs along with the 23-hydroxylated derivative of cholic acid (see below). 

Figure 4.105 Protein fingerprint separation of venom from Russell s viper on ProPac SCX-20. Eluent (A) 0.02 mol/L Tris (pH 73) and (B)...

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