RESUMO
Blood platelets are cells acting during primary haemostasis. The thrombocytopenia observed in many different types of infectious processes begs the question of the relationship between cells and infectious pathogens and the role of platelets in the detection of biological hazards. This in turn brings us back to the role of platelets - via their molecular, membrane and secretory arsenal - in the detection and repair of vascular hazards. The common denominator between a breakdown of haemostasis and the risk of infection has been shown to be a cutoff point in the inflammatory continuum between physiology and physiopathology. The trophic role of platelets - as topical factor and as platelet transfusions - and their inflammatory complexities appear to correlate this proposed model, as reported in this short review.
Assuntos
Plaquetas/imunologia , Hemostasia/fisiologia , Inflamação/fisiopatologia , Transfusão de Plaquetas/métodos , Humanos , Inflamação/sangue , Inflamação/imunologia , TrombocitopeniaRESUMO
Because variant Creutzfeldt-Jakob disease (vCJD) in humans probably results from consumption of products contaminated with tissue from animals with bovine spongiform encephalopathy, whether infectious prion protein is present in ruminant muscles is a crucial question. Here we show that experimentally and naturally scrapie-affected sheep accumulate the prion protein PrP(Sc) in a myocyte subset. In naturally infected sheep, PrP(Sc) is detectable in muscle several months before clinical disease onset. The relative amounts of PrP(Sc) suggest a 5,000-fold lower infectivity for muscle as compared to brain.