you fold incorrectly, forming clumps and deposits in the brain. Proteins named Beta-Amyloid (Aß) play in the pathogenesis of Alzheimer’s disease an important role. After the insoluble debris clogging the spaces between nerve cells that die in the disease inevitably. Now there is new evidence to suggest that these protein fragments could be in rare cases of human-to-human transferable, such as John Collinge of University College London and his colleagues in the journal “Nature” reports.
The administered growth hormones brought death
In a previous study, the British researchers the patients had examined who had died from Creutzfeldt-Jakob disease (CJD). They had all been as children, short stature and with growth hormone have been treated, it was at the time, nor the brains of the Deceased. However, some of the hormone preparations were contaminated with prions, the infectious agent of CJD.
in addition to the prions, the researchers in the brain of patients found vessels but also changes in the blood. The patients had the first signs of a disease called “Cerebral Amyloid angiopathy” (CAA) which are often used together with Alzheimer’s occurs. False-pleated Aß proteins are deposited on the inside of the vessel walls. Small quantities, called “Seeds” (seeds), can lead to the bales that like a snow ball, more and more of the proteins of a Plaque and the walls of the blood Vessels stiffen. A result can be bleeding in the brain, which can also be fatal.
the researchers, these changes in the brain were vessels of the patients the ultimate reference to the fact that the protein-Plaques – as well as the prion may also have been contaminated with medical products.
The proteins stored in the mouse
It is brains together was the only way to find out. They investigated at the time, the administered hormone preparations that have been lifted up now, again. And they were successful in finding Some of the samples contained a high proportion of two different Aß variants and Tau proteins, the researchers also with the development of Alzheimer’s connect. To find out whether the proteins could actually be for the changes in the brain of the deceased had been responsible, injected Collinge and colleagues of the proteins directly into the brain of mice.
In the brain of animals, the hormone supplements had to get the researchers found after a few months of Aß-deposits, and especially in the blood vessels. But not in the mice that received no hormones. “This shows that the hormone-batches of that time Ate-containing proteins, which are able to accumulate in mice with Plaques,” the researchers write. They do not exclude that it could come by way of contaminated medical products isolated to a Transfer of misfolded proteins to the people.
No evidence of Transmissibility of Alzheimer’s disease
this Means that even Alzheimer’s – for instance through contaminated Surgical instruments, can be transmitted from person to person? “This conclusion would be completely wrong,” says Frank Heppner, Director of the Institute for neuro-pathology at the Berlin Charité. Alzheimer’s disease is characterised not only by the detected Amyloid Plaques, but also by the accumulation of Tau proteins in the brain and the formation of a dementia. “Both was not, in the case of the then deceased patients in the case, just as little have found, the researchers are now in the mice.”
in addition, had been used in the attempt to genetically modified animals, which are particularly sensitive to the changes in the proteins, and this quasi – “like a Magnet” to attract. In normal mice this was different, this is also why the Experiment is hardly transferable to humans, so Heppner.
Still, the writing, the researchers, from population studies, there was no evidence to suggest that Alzheimer’s would be transferable, such as through blood transfusions. We have also found no increase in the incidence of the disease among family members or staff, the Alzheimer’s-has cared for patients.
don’t panic
Nevertheless, the authors of the study propose to assess the risks of Transmission of Amyloid Plaques in the case of medical interventions.
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The Robert Koch Institute provides the safety of blood and blood products in question, and pointed out that there are already methods to clean around surgical instruments so that no Aß and Tau impurities will be deported. “At a fair and reasonable Hygiene,” says Heppner, “is not a reason to panic.”
