(Transmissible spongiform encephalopathies)

Prion diseases are progressive, fatal and untreatable degenerative diseases of the brain. Prominent types include Creutzfeldt-Jakob disease (CJD), which represents the prototypical example, variant CJD (vCJD) Variable protease-sensitive Prionopathie (VPSPr) Gerstmann-Straussler-Scheinker syndrome (GSS) Lethal insomnia (FI) Kuru A new prion disease, tentatively called prion disease with diarrhea and autonomic neuropathy, was recently identified. Prion diseases are caused by the incorrect folding of a normal cell surface protein in the brain, the prion protein (PrPC)) is called and its exact function is unknown. Misfolded prion proteins, which are commonly referred to as prions or scrapie PrP (PrPSc derived from the name of the prototypical prion disease of sheep). Prions (PrPSc) are pathogenic and often contagious. They produce prion disease by replicating: PrPSc induces conformational conversion of PrP C, by creating double PrPSc that induced in chain reaction further conversion of PrPC into PrPSc. This transformation process is spreading in different regions of the brain. Causation of CNS degeneration is A large percentage of the PrPSc pronounced cleavage resistant (analogous to ?-amyloid, which is similar to), resulting in a slow but inexorable cellular accumulation and neuronal cell death. Pathological side effects are gliosis and characteristic histologic vacuolar (spongiform) changes that lead to dementia and other neurological deficits. The symptoms develop months or years after the initial exposure to PrPSc. Prion diseases arise (apparently spontaneous onset, with no known cause) Sporadic Via genetic inheritance through transmission of infection Sporadic prion diseases are the most common, with a global annual incidence of about 1.1 million people. Family Prion diseases are caused by defects in the PrP gene, which is located in the short arm of chromosome 20th The genetic mutations that cause prion diseases are autosomal dominant; i.e. they cause disease when inherited from only one parent. Also penetrance is variable; i.e. depending on the nature of the mutation, a variable percentage of carriers of the mutation has clinical signs of the disease. Some defects cause familial CJD, some of the GSS and other lethal familial insomnia (FFI), the hereditary form of the lethal insomnia (FI). Small abnormalities in specific codon (nucleotide sequences that are the building blocks of genes) can determine the predominant symptoms and the rate of disease development. borne infections prion diseases are rare. They can be transmitted from person to person: Iatrogenic about organ and tissue transplants, the use of contaminated surgical instruments or, rarely, through blood transfusion (like CJD); or by cannibalism (such as Kuru). From animals to humans: The admission of contaminated meat (like vCJD) It is not known that prion diseases are contagious by casual person-to-person contact. Prion diseases come in many mammals before (z. B. mink, moose, deer, kept as pets sheep and cattle) and can be transferred through the food chain between species. However, a transmission from animals to humans was observed only in vCJD after people have eaten beef from cattle with bovine spongiform encephalopathy (BSE or mad cow disease). In some western US states and in Canada, there is concern that chronic wasting disease (chronic wasting disease, CWD), the prion disease of elk and deer could be transferable consume on hunters, butchers or people, the animals concerned. However, the transmission of CWD is unlikely from animals to humans, unless the CWD was repeatedly transferred from animal to animal (which can happen in the wild), thus the barrier between species is weakened. Prion diseases should be considered in all patients with dementia into consideration, especially with very fast course. Treatment of prion diseases Supportive treatment A prion disease can not be treated. The treatment is symptomatic. Patients should be encouraged to prepare advance directives, (eg., Via the preferred end of life care). Genetic counseling is recommended for family members of patients with familial prion disease. Prevention of prion diseases Prion resist standard disinfection procedures and may be a risk to other patients and for surgeons, pathologists and technicians who deal with contaminated tissue or instruments. The transmission can be prevented by taking precautions when handling infected tissues and by using appropriate methods of cleaning contaminated instruments. The use of one of the following is recommended: materials at 132 ° C for 1 h sterilize Immerse in this Na hydroxide 1 N (normal) or 10% Na hypochlorite solution for 1 h


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