Fibrinolytic activity

Aplastic anemia and leukemia are not the only health effects ascribed to benzene exposure. A number of recent studies have associated benzene exposure with chromosomal changes (aberrations) (118). Other studies have shown abnormalities in porphyrin metabolism and decrease in leucocyte alkaline phosphatase activity in apparendy healthy workers exposed to 10—20 ppm benzene (119,120). Increases in leukoagglutinins, as well as increases in blood fibrinolytic activity, have also been reported and are believed to be responsible for the persistent hemorrhages in chronic benzene poisoning (121,122). 

Plasma Inhibitors, In Vivo Anticoagulants. Fourteen naturally occurring compounds that normally exert an inhibiting effect on the activity of coagulation, platelet function, and fibrinolytic activity and complement systems have been identified within the circulating blood. 

Streptokinase. The fibrinolytic activity of streptokinase, isolated from strains of hemolytic Streptococci, was first demonstrated in 1933 (63). Streptokinase is a secreted protein product inasmuch as filtrates free of demonstrable bacteria were found to dissolve fibrin clots with rapidity. 

The goals of the project were to confirm the molecular weight of hementin, determine the N-terminal amino acid sequence, and provide sufficient purified protein for biochemical studies of the fibrinolytic activity. These goals were all attained. Many of the issues that become important in devising a scalable process were identified, particularly... 

The fibrinolytic activity of scu-PA is more efficient than that of either LMW-UK or HMW-UK. Apparently, fibrin within a clot neutralizes an inhibitor in plasma that normally hinders binding of scu-PA to plasminogen, thereby facilitating binding of scu-PA to Glu-plasminogen and its resultant activation (37, 38). A cell surface receptor for scu-PA has been implicated in the activation of plasminogen and the internalization and degradation of u-PA complexed to inhibitors (39). 

Measurement of a peptide released by the action of plasmin on both cross-linked and non-cross-linked fibrin, which is called Bp 15-42, is useful for the assessment of fibrinolytic activity (94). 

Some physiological variables influence the measurement of fibrinolytic activators and inhibitors. For instance, both t-PA and plasminogen activator inhibitor 1 (PAI-1) levels in plasma are subject to diurnal variation in a 12-hour period. Even in samples taken at the same time of day the coefficient of variation (CV) of measured PAI levels range from 8 to 143% To account for this diurnal variation, blood samples spaced over several time intervals during a 24-hour period should be collected. Consumption of alcohol induces the PAI level in plasma. The half-life of t-PA is 360 seconds. However, in the presence of trauma or inflammation, when the PAI-1 level is expected to be elevated 10-fold, the half-life of t-PA is reduced to 36 seconds (114). 

Several investigators tried, with variable success, to detect a relationship between plasma concentrations of Lp(a) and in vitro parameters for fibrinolytic activity in the circulation (All, D11-D13, G3, H13, H25, S43-S46). 

Szczeklik, A., Radwan, J., Kubicka, A., Libura, M., Sacha, T., Swadzba, A., Undas, A., Szczeklik, J., and Jodlowski, J., Plasma fibrinolytic activity in healthy subjects with high and low lipoprotein(a) concentrations. Thromb. Res. 66, 391-395 (1992). 

Fondaparinux does not inactivate thrombin (activated Factor II) and has no known effect on platelet function, fibrinolytic activity, or bleeding time. 

Gliclazide is slowly absorbed. It is metabolized and excreted in the urine, in part as unchanged drug with an elimination half-life of 6-14 hours. Its duration of action is about 12 hours. Glicazide reduces platelet adhesiveness and increases fibrinolytic activity. This could be of importance as both factors have been implicated in the pathogenesis of the longterm organ failure in diabetes. 

DNA synthesis inhibition. Ethanol (90%) extract of the dried entire plant at a concentration of 0.25 mg/mL, was active " " ". Fibrinolytic activity. Ether extracts of the dried gum and gum resin, administered orally to 10 healthy subjects fed 100 g of butter to produce alimentary hyperlipemia, were active " "". ... 

Stage of treatment Fibrinogen, pg% Fibrinolytic activity, % Ht,% Time of serum recalcification, seconds Serum tolerance to heparin, min... 

TABLE 9.3. Enzymes that catalyze fibrinolytic activity leading to thrombolysis... 

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