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From: TSS ()
Mad Cows and Metals The proteins that, when mangled, cause "Mad Cow" and similar diseases also help regulate how yeast cells metabolize metals, biochemists report. Exposure to high levels of metals can coax proteins called prions to adopt an abnormal disease-causing conformation, the researchers found. That could explain why outbreaks of prion diseases have popped up in Iceland, Slovakia, and Colorado--regions with soils high in manganese. Now, biochemist Gerd Multhaup of the Free University of Berlin and colleagues have shown that prions alter metal metabolism in yeast. As a first step, they took a species of yeast that does not normally make prions and added prions that don't cause disease. Copper levels increased 1.6-fold inside these cells while manganese decreased by half compared to yeast without prion proteins, the researchers report in a paper to be published 13 June in Biochemistry. The researchers then added copper or manganese to the growth medium to form 1 to 5 millimolar concentrations; both additions transformed the prions to the indestructible form. At one time a skeptic, Multhaup says the new findings and prior evidence are starting to convince him that exposure to metal-enriched food and soils "is a risk factor" that increases susceptibility to prion diseases. David Brown, a neurochemist at the University of Bath in the United Kingdom, doesn't go that far but says the paper is "a good confirmation" that metals strongly influence prions. And yeast molecular biologist Mick Tuite of the University of Kent in the United Kingdom says that "any attempt to try and model prion conversion in vivo is an important step forward." But he questions the relevance of a yeast species that doesn't usually have prions and says more work in necessary to prove prions behave the same way in mammals. http://sciencenow.sciencemag.org/cgi/content/full/2006/531/3 PLEASE note, most important ; "exposure to metal-enriched food and soils "is a risk factor" that increases susceptibility to prion diseases." ... SOME will not understand and or distort this, and try to say that the feeding of tainted tissue is not the cause. amplification and transmission, we must not forget, and the many different modes of transmission. ...TSS Subject: FATEPriDE Environmental Factors that Affect the Development of Prion Diseases FATEPriDE Project funded by the European Commission under the Quality of Life Programme. Project No: QLRT-2001-02723 Start Date 1st January 2003 Duration 36 months plus 6 month extension Partners 1. The University of Bristol, UK (Co-ordinator) Introduction The work proposed here brings together top EU geo and biochemists focusing on determining the environmental factors that affect the development of prion diseases such as scrapie, bovine spongiform enchpalitis (BSE), chronic wasting disease (CWD) and Creutzfeld-Jacobs disease (CJD). First the geographical distribution of manganese and copper in soils will be investigated as risk factors. This will be undertaken due to the fact that prion diseases often are found in clusters. It now has been established that the normal metal for prion protein is copper but if that metal is replaced with manganese, the structure of the prion protein is altered. The role of organophosphate pesticides will also be investigated because it has been suggested that copper is complexed with organophosphate, preventing copper absorption. Objectives There is clear evidence that the occurrence of prion diseases often has a non-random distribution, suggesting a link to some environmental factors. The work proposed here will investigate risk factors, including the role of trace elements and organophosphates. Analysis of regional variation in local manganese/copper levels will be determined and compared to the incidence of the diseases. The ability of manganese and/or organophosphates in influencing conversion of the prion protein to an abnormal and/or infectious protein will be determined. In combination with geographical occurrence and geo-chemical considerations this program will identify whether these environmental considerations should be acted upon to bring about effective prevention or at least risk minimalisation of prion diseases in the EU and further afield. Description of the Work Recently it has been suggested that disbalance in dietary trace-elements and/or exposure to organophosphates might either cause or be a risk factor for prion disease development. In particular, high incidence of scrapie (e.g. in Iceland), chronic wasting disease, and in Slovakia and Italy CJD are associated with regions where soil and foliage are reported to be low in copper and high in manganese. This proposal will address whether exposure to a diet that has a high manganese/copper ratio can influence prion disease will also be addressed. In particular, we shall investigate this theory at the level of protein, cells, animals as well as geographical and geo-chemical associations with prion diseases. Animal models of prion disease and sheep from farms in regions of high scrapie will be investigated for a possible influence of level of manganese and copper on incidence or onset of these diseases. Bio-chemical and biophysical techniques will be used to investigate interaction of the prion protein with copper and manganese to determine the mechanism by which Mn substitution for Cu influences conversion to the abnormal isoform of the protein and whether such conversion results in protein that is infectious in mouse bioassay for infectivity. Additionally, a cell culture model will be used to generate abnormal prion protein by exposure to manganese. Cell culture model of infection will be used to assay whether prion disease alters manganese metabolism and transport of manganese into cells. The level of expression of the prion protein is in itself a risk factor for prion disease as it shortens the incubation time for the disease. This research will result in understanding of the role of disbalance in the trace elements Cu and Mn on the onset and mechanisms behind the occurrence of prion diseases and will for the first time define whether there are environmental risk factors for prion diseases. Milestones and Expected Results The study proposed here will produce a geo-chemical map of Europe for manganese and copper. These maps will be used to target field areas where prion diseases have occurred as clusters. The bio-chemical studies will establish whether the replacement of manganese for copper in prion protein is a risk factor for the disease _development_. Organophosphate will also be investigated as a risk factor. The study aims at minimising the risk of prion diseases for humans and animals in the EU. http://www.arp-manchester.org.uk/FatePride.htm http://europa.eu.int/comm/food/fs/sc/ssc/out356_en.pdf Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC. Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of PMID: 6997404 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6997404&dopt=Abstract (C) Lippincott-Raven Publishers. WHAT some of the OPiest/Metalist dont understand (refuse to understand to further there plight to squash the truth of the ruminant feeding spreads and amplifies the TSE agent) is that no where in science literature does it show that Phosmet or metals _CAUSE_ TSE, there is a big difference. TO distort, confuse, lie about the true aspect of this theory into trying to make people believe that Phosmet and or Metals _CAUSE_ TSE, only weakens the whole aspect of the study. but there will always be those that cannot admit the truth about the amplification and transmission of TSE, want to blame others, and will continue this deceit. ...TSS
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