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| BSE prion
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Epidemics in cattle are believed to have originated in sheep, in which the related prion disease scrapie is common. The tissues that contain most of the pathogenic molecules are those of the brain and the nervous system, although contagious amounts appear sometimes to be present in the blood. In the brain, these proteins form plaques, which lead to the appearance of holes in the brain, degeneration of mental abilities and death.
Following an epidemic of BSE in Britain, 152 people (as of 2003) acquired and died of a a disease with similar neurological symptoms. For many of them, direct evidence exists that they had consumed tainted beef, and this is assumed to be the mechanism by which all affected individuals contracted it. Disease incidence also appears to correlate with slaughtering practices that led to the mixture of nervous system tissue with of hamburger and other beef. The human disease was designated variant Creutzfeldt-Jakob disease (vCJD), after an extremely rare genetic prion disease whose symptoms it closely resembles.
Although the diseased herds were culled long ago, more people are diagnosed with vCJD each year. This implies that the disease has a long latency, as a result of which, public health experts do not know yet how many ultimately will contract it. The ease with which the disease can be contracted from beef therefore is not yet known.
Rodents injected with brain tissue from diseased cows begin to succumb to a similar neurological disorder in one or two years. With current tests, it is not possible to detect abnormal prions in the brains of all of these animals.On February 17 2004 a research team headed by Salvatore Monaco reported in the Italian Proceedings of the National Academy of Sciences that a second strain of mad-cow disease had been detected. It is not known if this second strain is transmissible to humans.
The BSE epidemic in the United Kingdom was discovered in 1986. BSE is thought to have spread by the practice of feeding cattle meat and bone mealMeat and bone meal (MBM) is a by-product of the rendering industry. It is typically about 50% protein, 35% ash, 8-12% fat, and 4-7% moisture. It is primarily used in the formulation of animal feed to improve the amino acid profile of the feed. Feeding of, a high-protein substance obtained from the remnants of butchered animals. This practice allowed the accumulation of prions over many generations. The use of meat and bone meal as a protein supplement in cattle feed was widespread in EuropeFor the band of the same name, see Europe (band . Europe is a continent forming the westermost part of the Eurasian supercontinent. Europe is bounded to the north by the Arctic Ocean, to the west by the Atlantic Ocean, to the south by the Mediterranean Se prior to about 1987. SoybeanSoybeans ( US) or soya beans ( UK) Glycine max are a high- protein legume (Family Fabaceae) grown as food for both humans and livestock. The word soy comes from Japanese shoyu. Soybeans may be boiled whole (in the green pod) and served with salt, often un meal is the primary plant-based protein supplement fed to cattle. However, soybeans do not grow well in Europe, so cattle raisers throughout Europe turned to the less expensive animal byproduct feeds as an alternative. A change to the rendering process in the early 1980's appears to have resulted in a large increase of the infectious agents in the cattle feed. A contributing factor seems to have been lax British laws that did not require a high temperature steriliziation of the protein meal. While other european countries like Germany required the said animal byproducts to undergo a high temperature steam boiling process, this requirement had been eased in Britain as a measure to keep prices competitive.
Of the 152 cases of vCJD in humans so far, 143 occurred in the United KingdomThe United Kingdom of Great Britain and Northern Ireland is a state in Western Europe, usually known simply as the United Kingdom the UK Britain or less accurately as Great Britain . The UK was formed by a series of Acts of Union which united the formerly, 6 in FranceThe French Republic or France ( French: Republique francaise or France is a country whose metropolitan territory is located in western Europe, and which is further made up of a collection of overseas islands and territories located in other continents., and one in Italy. Three cases of vCJD occurred in people who had lived in or visited Britain--one each in Ireland, Canada and the United States. There is also some concern about those who work with (and therefore inhale) cattle meat and bone mealMeat and bone meal (MBM) is a by-product of the rendering industry. It is typically about 50% protein, 35% ash, 8-12% fat, and 4-7% moisture. It is primarily used in the formulation of animal feed to improve the amino acid profile of the feed. Feeding of, such as horticulturalistsThe Latin words hortus ( garden plant) and cultura (culture) together form horticulture classically defined as the culture or growing of garden plants. Horticulture is, however, much more. Horticulturists work in plant propagation, crop production, plant, who use it as fertilizer.