Recent developments in the pathogenesis, diagnosis, and therapy of prion diseases.

Prions continue to pose a formidable challenge to life sciences. While human prion diseases are still rare, the incidence of a new variant of Creutzfeldt-Jakob disease in the United Kingdom is increasing exponentially - raising fears that it might develop into a major epidemic. This disease is likely to represent the result of human infection with bovine prions. Therefore, understanding how prions replicate and damage the brain, and how their action may be possibly counteracted, has become a major public health issue. Here I examine some current hypotheses concerning the links between bovine and human prion diseases, and the mechanisms by which prions reach and damage the central nervous system after having entered the body at extracerebral sites.