A tiny, protein-based infectious particle. Prions transmit diseases, including Creutzfeldt–Jakob disease in humans and bovine spongiform encephalopathy (BSE) in cattle. Prions do not contain nucleic acids and are difficult to destroy. As yet, no treatment is available for prion diseases.
An aberrant variety of one of the proteins, called PrP, in a brain cell. The result of a gene mutation (see GENES), prions are stable, resistant to radiation and impervious to the normal cellular processes of degradation. They seem to react with normal PrP, turning it into an abnormal type that then accumulates in brain tissue. Prions are believed to be the infectious agents that cause a group of serious neurological disorders called spongiform encephalopathies. CREUTZFELDT-JAKOB DISEASE (CJD), the new variant of CJD linked with BOVINE SPONGIFORM ENCEPHALOPATHY (BSE), and KURU – a neurological disorder found in a cannibal tribe in New Guinea – are all diseases in this group that occur in humans. The prion disorders have a long latent period between infection and manifestation of symptoms; they are hard to diagnose until autopsy and there is no cure as yet.
n. an abnormal form of a constituent protein (PrP) of brain cells. The abnormal proteins are very stable: they are not removed by the normal cellular processes of degradation and are resistant to radiation and sterilization (therefore surgical instruments need first to undergo *decontamination). They are believed to interact with normal PrP in such a way as to convert it to the abnormal form, which accumulates in the brain. Prions are now widely accepted as being the causal agents of a range of serious diseases including *Creutzfeldt–Jakob disease, *Gerstmann–Straussler–Scheinker syndrome, and *kuru, all of which are *spongiform encephalopathies. Different mutations in the PrP gene are believed to be responsible for the different forms of these so-called prion disorders.
Formally known as the “slow viruses”. Prions are in reality transmissible abnormal proteins infecting the CNS. They cause such human diseases as Kuru, Creutzfeld-Jacob Disease (CJD), bovine spongiform encephalitis (‘mad cow disease’) – all of which are characterised by their ext remely long incubation period.... prions
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