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Breakthrough in role of genes
in Alzheimer's Trends Prof Yash
Pal THIS UNIVERSE |
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Breakthrough in role of genes
in Alzheimer's Scientists
have discovered that three known genes play important roles in determining the risk that someone will develop Alzheimer’s disease – a finding that could lead to new treatments and a possible early test for one of the most feared disorders of later life. It is the first time in 15 years that researchers have identified new genetic factors that definitely raise someone’s risk of getting the degenerative brain disease. The breakthrough means that a total of four genes are now known to contribute to Alzheimer’s. Scientists hope that further genetic discoveries could soon lead to a diagnostic test that can provide a meaningful assessment of whether someone is likely to develop the condition. Such a test would help doctors to identify patients at greatest risk of the disease, although it might also be seized upon by insurance companies and other organisations concerned about the cost of long-term healthcare in old age. Alzheimer’s disease is one of the fastest growing and most costly medical conditions in the developed world. In Britain, about 700,000 people have some form of dementia including Alzheimer’s disease. This will grow to about 940,000 by 2015, and to more than 1.7 million by 2051, as a result the ageing population. Two large international teams of researchers announced their findings last night, saying that detailed scans of the entire genomes of a combined total of nearly 20,000 people from eight countries have implicated the three genes, which were already known to play important roles within the brain. Sir Leszek Borysiewicz, the chief executive of the Medical Research Council (MRC), which part-funded the British study, said the findings, published in the journal Nature Genetics, were crucial in piecing together the complicated picture that can help to explain the Alzheimer’s puzzle. “This study is a huge step towards achieving an earlier diagnosis of Alzheimer’s and improving the lives of the many people affected by the disease,” Sir Leszek said. In the British study, carried out at the MRC’s Centre for Neuropsychiatric Genetics and Genomics in Cardiff, scientists analysed more than half a million differences in the DNA in each of 4,000 people who had Alzheimer’s, and compared them with the DNA of 8,000 people without the disease. A comparable study carried out by the European Alzheimer’s Disease Initiative in France compared nearly 4,000 Alzheimer’s patients with a comparable number of people who did not have the condition. The British study found two genes and the French found the third, as well as confirming one of the British discoveries. Professor Julie Williams of Cardiff University, who led one of the research teams, said that the findings are “significant and conclusive” in terms of linking variations in the three genes to the risk of developing Alzheimer’s. “If we were able to remove the detrimental effects of these genes through treatments, we could reduce the proportion of people developing Alzheimer’s by 20 per cent,” Professor Williams said. “In the UK alone this would prevent just under 100,000 people developing the disease.” The three new genes implicated in Alzheimer’s are called CLU, PICALM and CR1. They are the first genes linked to the disease since the discovery 15 years ago of the role of the APOE gene in raising the risk of Alzheimer’s. “Three of the risk genes, APOE, CLU and CR1, have roles in protecting the brain from damage. Perhaps the changes we see in these genes remove this protection or may even turn them into killers,” Professor Williams said. “Our results may highlight new targets for treatments. For example, CLU has a role in dampening down inflammation in the brain,” she said. “Up until now, increased inflammation seen in the brains of Alzheimer’s sufferers had been viewed as a secondary effect of disease,” she said. “Our results suggest the possibility that inflammation may be primary to disease development.” Professor Michael Owen, director of the MRC centre said the research will next be expanded it to a full genome-wide analysis of 60,000 volunteers. This should allow the scientists to pinpoint changes in other genes that play a smaller, yet significant role in raising the risk of Alzheimer’s. The value of this genetic approach to studying Alzheimer’s has now been established beyond a doubt, he said.
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Hubble spots distant stardust WASHINGTON: The freshly repaired and outfitted Hubble Space Telescope has spotted a new butterfly-shaped galaxy and wisps of stardust containing the elements of life being recycled into new galaxies, NASA said on Wednesday. The space agency released the first batch of images from the orbiting Hubble, repaired by shuttle astronauts in May, and said they show the once-doomed telescope has been reinvented yet again.
Vaccines could halve sickle-cell deaths LONDON: Vaccination against bacterial infections using vaccines readily available in developed countries could save the lives of thousands of children with sickle-cell anemia in Africa, researchers said on Thursday. Tom Williams, an expert in tropical diseases from the Kenya Medical Research Institute (KEMRI), said 90 percent of children born with sickle-cell anemia in Africa die before they are diagnosed and can get treatment, and half of those lives could be saved if sufferers were protected from bacterial infections.
Prostate cancer stem cell found WASHINGTON: Researchers have found a stem cell, a kind of master cell, that may cause at least some types of prostate cancer. Their findings are only experimental—the stem cells were found in mice—but could explain at least some types of prostate cancer and eventually offer new ways to treat it, they reported on Wednesday in the journal Nature. Scientists unlock secrets of Irish potato famine genome CHICAGO: Scientists have unlocked the genetic code of late blight—the plant pathogen that sparked the Irish potato famine of the 1840s and 1850s—and it is revealing clues about why it has been such a formidable foe. They said on Wednesday the Phytophthora infestans or late blight genome is nearly “animal sized” and loaded with extra DNA that allows it to quickly adapt to overcome any defense the host plant might mount.
NASA aims for Mars over moon CAPE CANAVERAL, Florida: A NASA strategy proposal shifts the U.S. human space program away from returning to the moon in favor of a stepping-stone approach aimed at reaching Mars, including using commercial space launch services, according to a document seen by Reuters. The proposal is not yet official policy but is the U.S. space agency’s response to one of five options contained in review ordered by President Barack Obama of NASA’s post-shuttle program that plans to put humans on the moon again by 2020.
Shuttle undocks from station HOUSTON:
Seven astronauts aboard the US shuttle Discovery undocked from the International Space Station on Tuesday and set their sights on a Thursday landing in Florida. Shuttle pilot Kevin Ford backed the craft away from the station as it orbited 223 miles above western China, near the Mongolian border.
— Reuters |
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THIS UNIVERSE Why the chimney of a big mill#
is very tall? Chimneys of big mills or power houses are tall because of two reasons: Firstly you want to release the smoke and other products of combustion at high altitude to protect people living close by. But the more practical reason is that a tall chimney contains a long column of hot gases and air. This helps convection of air and helps to draw in lot of fresh air from below, into the furnace to help combustion of coal, oil or whatever is burnt to produce energy. India plans to go substantially for adding nuclear power generation in next few decades. It will naturally face problems in disposing off spent nuclear fuel. Nuclear energy production eventually creates waste in the form of spent nuclear fuel. High-level radioactive waste makes up the smallest volume of radioactive waste, around three percent of the world's total, but it contains approximately 95 percent of all the radioactivity. In future, instead of underground disposal, would it not be feasible and advisable to put high-level waste in a container, mount it on a rocket and fire same towards Sun whose gravity will suck in this waste? You are quite right worrying about the problem of nuclear wastes. There are no easy solutions. You have suggested the possibility of sending them to the sun using powerful rockets. This has been thought of, but not very seriously. People worry about the costs involved and the dangers of spreading radioactivity if accidents happen. Incidentally I do not know of any instance of a rocket being sent to the sun. It is not impossible, but the project would be very challenging. Reduction of nuclear waste is a point that has been emphasised in the future plans of India. Our plan emphasizes what Kakodkar calls a closed cycle. This involves use of Thorium as the basic fuel that is combined with Plutonium to breed more fuel. The idea is to reuse the highly radioactive ashes of the earlier stages. But the problem will remain till controlled fusion becomes a reality. Readers wanting to ask Prof Yash Pal a question can e-mail him at palyash.pal@gmail.com |
