Human brain disease recreated in mice

Article Abstract:

Prions are particles made up only of protein, with no nucleic acid (the genetic material essential for replication of living cells). In 1980, Stanley Prusiner suggested that prions caused scrapie, an infectious brain disease of sheep. This was hard to accept by other scientists. However, in 1985, a prion gene encoding a protein known as PrP was cloned by a collaborative effort of groups headed by Prusiner, Charles Weissmann and Lee Hood; this gene was found to be expressed in the brains of higher organisms. During the past two years, studies have shown that genetic mutations in the PrP gene may cause two human brain diseases similar to scrapie, Gerstmann-Straussler-Scheinker syndrome (GSS) and Creutzfeldt-Jakob disease. Prusiner's group at the University of California at San Francisco has transplanted the mutated PrP gene into transgenic mice (which have received a foreign gene at the embryonic stage) and recreated GSS. This shows that the prion is involved in the disease state in the brain. A genetic link has been shown between patients with GSS and the mutated prion PrP gene. The mutated gene has been shown to be present in patients with GSS and not in other family members who are not affected by the disease. GSS is extremely rare, affecting one in 10 to 100 million people. However, some of the pathological features are similar to those in Alzheimer's disease. Similar studies have been done in patients with Creutzfeldt-Jacob disease, which have also shown a mutation in the prion gene. This mutation is different than that seen in GSS. Questions still exist on the role of the prion gene in the diseases, including how the disease can spread to other animals, without having an infectious agent that can replicate, and whether the prion gene associates with other agents. Experimental animals have now been injected with brain extracts from sick mice that had received the transplanted gene. If these animals get sick, it will indicate that the mutated prion gene is all that is necessary for the prions to be infectious. The results of these experiments will take time. (Consumer Summary produced by Reliance Medical Information, Inc.)

Usage, Prions, Prions (Proteins), Creutzfeldt-Jakob disease, Genetically modified mice, Scrapie, Gerstmann-Straussler-Scheinker syndrome

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Holding the line against heart disease

Article Abstract:

The endothelium, the tissue that lines the inside of blood vessels, the heart and other parts of the body, plays a crucial part in helping blood vessels do their work. Blood vessels themselves help to regulate blood pressure by expanding and contracting (vasodilation and vasoconstriction), and are important in blood clotting. If the endothelial cells cannot or do not repair themselves, serious illness such as atherosclerosis (the accumulation of fatty plaques in blood vessels) and high blood pressure, which in turn may lead to heart attack or stroke, are likely to occur. Moreover, researchers now believe that damage to the endothelial cells is responsible for excessive atherosclerosis in the hearts of patients who have received heart transplants. Patients who undergo balloon angioplasty to treat blocked coronary arteries may also be at high risk for endothelial cell damage. Balloon angioplasty consists of threading a thin tube with a deflated balloon on it into the affected artery, and inflating the balloon to push away the material blocking the artery. The problem is that in about 25 percent of patients, the arteries block up again with six months. This may be due to endothelial damage that occurs during the procedure. Endothelial cells act on and are acted upon by other body substances such as enzymes and substances produced by certain blood cells. When the endothelium is damaged, these interactions cannot take place. Then the endothelium may not be able to heal itself and that, in turn, leads to the progression of disease in the blood vessels and heart. (Consumer Summary produced by Reliance Medical Information, Inc.)

Causes of, Coronary heart disease, Atherosclerosis, Cerebrovascular disease, Cerebrovascular disorders, Vascular endothelium

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Mutant enzyme provides new insights into the cause of ALS

Article Abstract:

Research indicates that the enzyme copper/zinc-dependent superoxide dismutase (CuZnSOD) coded by the SOD1 gene plays a key role in the development of ALS. The researchers believe that mutations in the SOD1 gene may enhance the ability of the enzyme to oxidize lipids and other cell components.

Health aspects, Antioxidants, Antioxidants (Nutrients), Genetic disorders, Amyotrophic lateral sclerosis

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