ISLAMABAD (Online)- A rare genetic mutation may underlie some cases of mad cow disease in cattle and its discovery may help shed light on where the epidemic started, U.S researchers reported. The mutation, in an Alabama cow that tested positive in 2006 for bovine spongiform encephalopathy, or BSE, is identical to one that causes a related brain-wasting disease in humans. This suggests BSE may sometimes arise spontaneously in cattle. Jurgen Richt of Kansas State University said cattle producers must never let down their guard against BSE because cattle anywhere, at any time, can develop the disease. The finding may support a 2005 theory that the BSE epidemic in cattle could be traced to feed contaminated with cattle remains from India, the researchers report in the Public Library of Science journal PLoS Pathogens. BSE or mad cow disease swept through British dairy herds in the 1980s, forcing the destruction of millions of animals. No one ever found where it came from but most experts thought at the time it came from cattle feed that contained the remains of sheep infected with a similar disease called scrapie. Cattle were never known to develop BSE before the epidemic, but some experts have argued they may have. This report lends credence to that idea. BSE, scrapie and a human version called Creutzfeldt-Jakob disease, or CJD, are brain-destroying illnesses called transmissible spongiform encephalopathies. In some cases, animals or people that eat brain and nervous system material from victims of these diseases can develop them, too. They are passed along by misfolded infectious protein fragments called prions. Heart damage prevention hope US researchers have identified a protein, which reduces the extent of damage caused by a heart attack, and may prove useful during bypass surgery. Higher levels of the ALDH2 enzyme were found in rats resistant to heart muscle damage caused by a lack of oxygen. Boosting levels of the enzyme before initiating a heart attack in the animals cut the amount of dead heart tissue by 60%, the Science study said. ALDH2 is usually involved in breaking down alcohol in the body. During a heart attack, a clot blocks blood flow to the heart. The lack of oxygen and build up of toxins causes tissue to die. This is also a danger during coronary bypass surgery, when blood flow is redirected to allow surgeons to operate. Once the researchers worked out that ALDH2 seemed to reduce damage to heart tissue they screened a variety of molecules which would increase its production. One, Alda-1, was particularly effective and may be a potential drug target should the findings be replicated in humans, they said. It is thought the protective effect is due to the removal of cell-damaging molecules, known as free radicals, by ALDH2. The researchers said their findings also have implications for current treatments. Nitroglycerin, a drug given to widen arteries and improve blood flow in people with chest pain, is converted to its active form by ALDH2 but prolonged use of the nitroglycerin can reduce the presence of the enzyme, potentially increasing damage to the heart. Enzyme mutation, the Alda-1 molecule was able to keep enzyme levels high during nitroglycerin treatment reducing the amount of damage. This would be a particularly important in-patient from East Asia who has a mutation in the ALDH2 enzyme, making it less efficient the researchers said. "Although this enzyme was discovered a long time ago, my research group knew nothing about it except that it helps remove alcohol when people drink," said study leader Dr Daria Mochly-Rosen, a researcher at Stanford University Medical Centre. "We've found a totally new pathway for reducing the damage caused by free-radicals, such as the damage that happens during a heart attack." Judy O'Sullivan, a cardiac nurse at the British Heart Foundation, said the "interesting finding" could potentially be of great benefit to patients. "However, it will take many years before this could be confirmed in humans and then several more years before it would lead to the development of drug treatment to be used in clinical practice." Selenium enriched milk may help prevent cancer The cow could play a role in boosting the anti-cancer properties of the natural trace element, selenium, according to a new study. A team led by Graeme Young of Flinders University is testing the beneficial impact that selenium delivered through cow's milk has in preventing bowel cancer compared to other forms of the dietary supplement. The latest trial followed earlier research that confirmed selenium in cow's milk could lift levels of selenium in the blood. The current study, involving 20 healthy volunteers, is trying to establish the extent to which the selenium is delivered to cells in the lining of the bowel for maximum effect. Young said chemical and yeast-based forms of selenium available 'over-the-counter' as dietary supplements have varying degrees of absorption and impact on the body. "So those forms of selenium will differ in their capacity to change someone's antioxidant status and capacity to prevent cancer," Young said. "It just so happens that when you feed selenium to cows and they produce selenium-enriched milk, the selenium seems to be in a chemical form that is both highly absorbable into the body and also more effective in terms of preventing cancer," he said. "We are comparing the milk form of selenium with a yeast-form of selenium in this human study and looking to see how readily the selenium gets into the body. "We are also taking biopsies from the lining of the bowel to make certain that the selenium is being delivered to the cells lining the bowel. If we can establish that is occurring, then we will be more confidant that selenium is going to regulate the cells lining the bowels in humans." The anti-cancer impact of selenium is achieved by the way in which it encourages the body to rid itself of mutated cells that might otherwise become cancerous. Previous research by the team from Flinders Centre for Cancer Prevention and Control published in the June issue of Cancer Resarch, showed that selenium-enriched cow's milk produced a significant cancer preventing effect in mice.