Word: amyloid
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...evidence that other factors--high-fat diets, for instance--may substantially elevate that risk. And most exciting of all, they will discuss the first clinical trials of compounds that target what many believe to be the cause of Alzheimer's disease--a sticky snippet of protein known as beta amyloid. A controversial yet compelling hypothesis--long championed by Selkoe, among others--contends that excessive amounts of beta amyloid are toxic to neurons in the same way that too much cholesterol is toxic to the cells in blood-vessel walls...
Indeed, unless these clinical trials run into unexpected snafus, a long and fierce debate may soon be resolved. As the Alzheimer Association's Thies puts it, "Either the beta-amyloid hypothesis is correct, in which case new therapies should come very quickly, or it isn't, in which case researchers at major laboratories will very quickly switch their efforts to more productive directions...
...then that the question of what caused Alzheimer's disease--the plaques or the tangles--began to loom large. In the mid-1980s, researchers isolated beta amyloid--a generic name for a class of sticky proteins--from the brains of Alzheimer's patients. A short time later, four research teams zeroed in on the gene that encodes the recipe for making the protein. To their great surprise, they discovered that beta amyloid was a fragment of a much larger protein, which came to be known as the amyloid-precursor protein, or APP for short...
...most straightforward approach to fighting Alzheimer's plaques is to target their main ingredient, a protein called beta amyloid. Last summer scientists from Elan Pharmaceuticals, a biotech firm located in Ireland, reported that they had developed a vaccine that could shrink the plaques--at least in mice. Here the idea is to prime the immune system to treat amyloid proteins just as it would any foreign invader and target them for destruction. The concept is somewhat counterintuitive, since most researchers believe that at least part of the damage in Alzheimer's disease is caused by the immune system's overreaction...
Another approach, favored by several large pharmaceutical companies, is to try to block the body's production of amyloid proteins. It turns out that everyone makes beta amyloid throughout his brain and body (more on that later). But people who, for genetic reasons, tend to get Alzheimer's at an early age--in their 40s or 50s--seem to shape the protein into a stickier version that is more likely to clump together. By inhibiting an enzyme called gamma secretase, which facilitates amyloid production, researchers hope to push amyloid production so low that no new plaques will form...