Eradication of Some Arctic Infectious Diseases

Eradication of a communicable disease is defined as the complete elimination of the infectious agent for the world. The term should he restricted to this concept and thus national or regional programs can only be considered in relation to the global effort. The financial implication in eradication is that a short-term campaign will be much cheaper than the eternal maintenance of a control program. A limited time element is implied.     

Activated protein C decreases plasminogen activator-inhibitor activity in endothelial cell-conditioned medium

Confluent cultures of endothelial cells from human umbilical cord were used to study the effect of activated human protein C (APC) on the production of plasminogen activators, plasminogen activator-inhibitor, and factor VIII-related antigen. Addition of APC to the cells in a serum-free medium did not affect the production of tissue-type plasminogen activator (t-PA) or factor VIII-related antigen; under all measured conditions, no urokinase activity was found. However, less plasminogen activator-inhibitor activity accumulated in the conditioned medium in the presence of APC. This decrease was dose dependent and could be prevented by specific anti-protein C antibodies. No decrease was observed with the zymogen protein C or with diisopropylfluorophosphate-inactivated APC. APC also decreased the t-PA inhibitor activity in endothelial cell-conditioned medium in the absence of cells, which suggests that the effect of APC is at least partly due to a direct effect of APC on the plasminogen activator- inhibitor. High concentrations of thrombin-but not of factor Xa or IXa-- had a similar effect on the t-PA inhibitor activity. The effect of APC on the plasminogen activator-inhibitor provides a new mechanism by which APC may enhance fibrinolysis. The data suggest that activation of the coagulation system may lead to a secondary increase of the fibrinolytic activity by changing the balance between plasminogen activator(s) and its (their) fast-acting inhibitor.