Creutzfeldt-Jakob disease

Creutzfeldt-Jakob Disease (CJD) is a very rare and incurable brain disease that is ultimately fatal. It is the most common of the transmissible spongiform encephalopathies (TSEs). TSEs (also known as prion diseases) are caused by a unique type of infectious agent called prions, an abnormally-structured form of a protein found in the brain. Other prion diseases include Gerstmann-Sträussler-Scheinker syndrome (GSS), fatal familial insomnia (FFI) and kuru in humans, as well as BSE and scrapie in animals.

Prions

The prion that is believed to cause Creutzfeldt-Jakob exhibits (at least) two stable conformations. One, the native state, is water soluble and present in healthy cells. As of 2005, its biological function is unknown. The other conformational state is very poorly water-soluble and readily forms protein aggregates. The CJD prion is dangerous because it promotes refolding of native protein into the diseased state. The number of misfolded protein molecules will increase exponentially and the process leads to a huge load of insoluble prions in affected cells. This mass of insoluble proteins disrupts cell function and causes cell death. Once the prion is transmitted, the defective proteins invade the brain and get produced in a self-sustaining feedback loop, causing exponential spread of the prion, and the patient dies within a few months; a few patients live for about 1-2 years. The defective protein can be transmitted by human growth hormone (HGH) products, corneal grafts or dural grafts (acquired or iatrogenic form, called iCJD) or it can be inherited (hereditary or familial form: fCJD) or it may appear for the first time in the patient (sporadic form: sCJD). In the hereditary and sporadic forms of the disease, the patient will sometimes carry a mutation in the involved protein which makes it more vulnerable to spontaneous misfolding.

Related Topics:
Conformations - Increase exponentially - Cells - Feedback loop - Exponential - Human growth hormone - Cornea - Iatrogenic - ICJD - FCJD - SCJD

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Cannibalism has also been implicated as a transmission mechanism for abnormal prions, the disease being known as Kuru found primarily among women and children of the Fore tribe in Papua New Guinea. The disease has also been shown to result from usage of HGH drawn from the pituitary glands of cadavers who died from Creutzfeldt-Jakob Disease http://www.wired.com/news/medtech/0,1286,62998,00.html, though the known incidence of this cause is (as of April 2004) quite small. Infection through HGH usage is restricted to patients in the U.S. who were treated with HGH during or before 1977, when newer methods of HGH purification were adopted.

Related Topics:
Cannibalism - Kuru - Fore tribe - Papua New Guinea - HGH - Pituitary gland - Cadaver

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