Essay about Prions

1124 Words Apr 16th, 2005 5 Pages
Sometimes a scientific discovery shakes the confidence of scientists, making them question whether they truly understand nature's ground rules. That's exactly what prions have done to scientists' understanding of the ground rules for infectiousdiseases. Prions cause diseases,but they aren't viruses or bacteria or fungi or parasites. They are simply proteins, and proteins were never thought to be infectious on their own. Organisms are infectious, proteins are not. Or, at least, they never used to be. Prions entered the public's consciousness during the mad cow epidemic that hitEngland in 1986. For decades, however, scientists had searched for unusual, atypical infectious agents that they suspected caused some puzzling …show more content…
This epidemic was something new, something extraordinary. Scientists now speculate that the prions that started out in sheep suffering from scrapie made their way into cows and then moved more recently into humans. Cattle are fed meal made from sheep, the bones and other waste parts of sheep carcasses. Standard procedures for grinding up carcasses were altered in the 1970s, and the new processing methods seem not to have been adequate for destroying scrapie prions. The cattle were exposed, through the offal, to sheep prions, and the prions eventually established themselves in their cow hosts. Later, they adapted further, infecting cells of people who had eaten hamburgers from prion-bearing cows. At the moment, CJD and only a handful of other human diseases have clear links to prions. But it is likely that prions will turn out to be the agents of a variety of currently enigmatic diseases in which brain cells are destroyed and the nervous system deteriorates. Alzheimer's disease and Parkinson's disease are two prime candidates. So, a couple new ground rules now seem to govern infectious diseases. The first is that naked proteins- prions -can be infectious and can cause infectious diseases. The second and potentially more troubling

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