Transmissible spongiform encephalopathy

Transmissible spongiform encephalopathies (TSEs) are fatal, incurable degenerative diseases of the brain transmitted by prions. Mental and physical abilities deteriorate and myriad tiny holes appear in the cortex causing it to appear like a sponge (hence 'spongiform') when brain tissue obtained at autopsy is examined under a microscope.

Related Topics:
Brain - Prion - Cortex - Autopsy - Microscope

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Unlike other kinds of infectious disease which are spread by microbes, the infectious agent in TSEs is a specific protein called prion protein. Misshaped prion proteins carry the disease between individuals and cause deterioration of the brain. TSEs are unique diseases in that they can be inherited, occur spontaneously ("sporadic" TSE) or can be spread through infection (Collinge, 2001). Most TSEs are sporadic and occur in an animal with no prion protein mutation. Inherited TSE occurs in animals carring a rare mutant prion allele, which expresses prion proteins that contort by themselves into the disease-causing conformation. Transmission occurs when healthy animals consume tainted tissues from others with the disease . In recent times a type of TSE called bovine spongiform encephalopathy (BSE) spread in cattle in an epidemic fashion. This occurred because cattle were fed the processed remains of other cattle (now banned in many countries). The epidemic could have begun with just one cow with sporadic disease.

Related Topics:
Microbe - Protein - Prion - Brain - Mutant - Allele - Conformation - Bovine spongiform encephalopathy - Cattle

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Prions cannot be transmitted through the air or through touching or most other forms of casual contact. However, they may be transmitted through contact with infected tissue, body fluids, or contaminated medical instruments. Normal sterilization procedures such as boiling or irradiating materials fail to render the pathogens non-infective.

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