SummaryWe demonstrate that exposure of cultured human endothelial cells to rHuEPO resulted in a dose-dependent increase in the tyrosine kinase activity, with phosphorylation of JAK-2 followed by rapid phosphorylation of STAT-5. Simultaneously, rHuEPO induced long-lasting phosphorylation of MAPK p42/44. Activation of this signaling pathways was directly associated with an increase in the thrombogenic properties of the extracellular matrix generated by these cells, when they were exposed to flowing blood. The enhancement in the reactivity of the resulting extracellular matrix towards platelets was associated with a higher expression of tissue factor. All these effects were blocked by an antibody to the EPO receptor and by specific inhibitors of tyrosine phosphorylation. The observed action of rHuEPO on endothelial cells seemed to be specifically triggered by the subsequent events that follow receptor binding, and occurred even at pharmacological concentrations of the cytokine. Our results indicate that rHuEPO has a direct action on the endothelium, increasing the reactivity of the underlying extracellular matrix towards platelets, effect that may be attributed to an increase in the expression of TF.
The aim of this study was to investigate pretreatment prognostic factors that could be useful in predicting the response to plasma exchange in thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS). Thirty-two patients with TTP/HUS, treated with plasma exchange at our institution from 1980 to 1994, were studied. The main clinical and laboratory data at the beginning of plasma exchanges were analyzed by the Cox stepwise logistic regression, applied to either treatment failure or death. Seventeen (53%) patients attained a complete remission and 22 (69%) survived (five in advanced renal failure and long-term hemodialysis). Longer delay in initiating plasma exchanges, presence of stupor or coma, and higher creatinine levels at the beginning of plasma exchanges were independent predictors of treatment failure. Stupor or coma at the beginning of plasma exchanges was the only predictor of mortality from unremitted TTP/HUS. Hemoglobin levels, platelet count, and LDH activity, traditionally envisaged as markers of disease activity, neither correlated with previous duration of TTP/HUS nor had any prognostic value. Early diagnosis of TTP/HUS and prompt initiation of intensive plasma exchange emerged from this study as the most effective interventions for improving the prognosis of TTP/HUS patients.
This case report describes a patient with twiddler’s syndrome, a rare condition of permanent pacemaker failure resulting from inadvertent or deliberate rotation of the pulse generator causing lead dislodgement. This report underscores the importance of dementia as a risk factor for twiddler’s syndrome.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.