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WASHINGTON, Oct. 3 (Xinhua) -- Researchers at St. Michael's Hospital in Canada have discovered a new function for an enzyme that may protect against organ injury and death from anemia, according to a study appearing Monday in the U.S. journal of the Proceeding of the National Academy of Sciences.Researchers found that when people have anemia, neuronal nitric oxide synthase (nNOS) -- an enzyme in nerve cells that produces nitric oxide, an important signaling molecule in the body -- increases the body's ability to respond, adapt to low oxygen levels and makes the body more efficient in delivering oxygen to tissues. They also found that levels of nNOS in the brain increased in anemic mice, and that the mice without this enzyme die earlier, and with higher hemoglobin levels."Identifying this mechanism may lead to new therapies and approaches to improving outcomes for anemic patients," said Dr. Greg Hare, a researcher at the Li Ka Shing Knowledge Institute of the hospital and one of the lead investigators of the study.Anemia occurs when blood has a lower than normal number of red blood cells or hemoglobin -- an iron-rich protein that carries oxygen from the lungs and heart to the rest of the body. Cells need oxygen to survive and to produce energy for all bodily functions. The condition has many different causes including infection (malaria, HIV, parasites), nutritional deficiencies (iron, folate, B12), genetic mutations, pregnancy, trauma and surgical blood loss."This research will help us identify when an anemic patient is at greatest risk for injury and death when undergoing surgery," said Hare. "Research is underway to test these findings in humans."

WASHINGTON, Dec. 20 (Xinhua) -- NASA's Kepler mission has discovered the first Earth-size planets orbiting a sun-like star outside our solar system, the U.S. space agency announce Tuesday.The planets, called Kepler-20e and Kepler-20f, are too close to their star to be in the so-called habitable zone where liquid water could exist on a planet's surface, but they are the smallest exoplanets ever confirmed around a star like our sun, according to NASA.The discovery marks the next important milestone in the ultimate search for planets like Earth. The new planets are thought to be rocky. Kepler-20e is slightly smaller than Venus, measuring 0.87 times the radius of Earth. Kepler-20f is slightly larger than Earth, measuring 1.03 times its radius. Both planets reside in a five-planet system called Kepler-20, approximately 1, 000 light-years away in the constellation Lyra.Kepler-20e orbits its parent star every 6.1 days and Kepler-20f every 19.6 days. These short orbital periods mean very hot, inhospitable worlds. Kepler-20f, at 800 degrees Fahrenheit, is similar to an average day on the planet Mercury. The surface temperature of Kepler-20e, at more than 1,400 degrees Fahrenheit, would melt glass."The primary goal of the Kepler mission is to find Earth-sized planets in the habitable zone," said Francois Fressin of the Harvard-Smithsonian Center for Astrophysics, lead author of a new study published in the journal Nature. "This discovery demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."The Kepler-20 system includes three other planets that are larger than Earth but smaller than Neptune. Kepler-20b, the closest planet, Kepler-20c, the third planet, and Kepler-20d, the fifth planet, orbit their star every 3.7, 10.9 and 77.6 days. All five planets have orbits lying roughly within Mercury's orbit in our solar system. The host star belongs to the same G-type class as our sun, although it is slightly smaller and cooler.

WASHINGTON, Jan. 16 (Xinhua) -- A new study examining weather patterns around the worldwide pandemics of influenza, which caused widespread death and illness in 1918, 1957, 1968 and 2009, finds that each of them was preceded by La Nina conditions in the equatorial Pacific. The study findings are published online Monday in the Proceedings of the National Academy of Science.The study's authors -- Jeffrey Shaman of Columbia University's Mailman School of Public Health and Marc Lipsitch of the Harvard School of Public Health -- note that the La Nina pattern is known to alter the migratory patterns of birds, which are thought to be a primary reservoir of human influenza. The scientists theorize that altered migration patterns promote the development of dangerous new strains of influenza.To examine the relationship between weather patterns and influenza pandemics, the researchers studied records of ocean temperatures in the equatorial Pacific in the fall and winter before the four most recent flu pandemics emerged. They found that all four pandemics were preceded by below-normal sea surface temperatures -- consistent with the La Nina phase of the El Nino- Southern Oscillation.The authors cite other research showing that the La Nina pattern alters the migration, stopover time, fitness and interspecies mixing of migratory birds. These conditions could favor the kind of gene swapping or genetic reassortment that creates novel and therefore potentially more variations of the influenza virus."We know that pandemics arise from dramatic changes in the influenza genome. Our hypothesis is that La Nina sets the stage for these changes by reshuffling the mixing patterns of migratory birds, which are a major reservoir for influenza," says Shaman.Changes in migration not only alter the pattern of contact among bird species, they could also change the ways that birds come into contact with domestic animals like pigs. Gene-swapping between avian and pig influenza viruses was a factor in the 2009 swine flu pandemic.

BEIJING, Oct. 11 (Xinhuanet) -- An experimental drug that can remove amyloid plaques from the brains of Alzheimer's patients is being developed by Swiss Roche Holding AG in a small early-stage study, according to a report published in the Archives of Neurology on Monday.Researchers suspect the build-up of such plaques may be a cause of the memory robbing disease, although that theory has yet to be definitively proved. Gantenerumab, a biotech drug designed to bind to amyloid plaques in the brain and remove them, is being targeted at the early stages of Alzheimer's with the hope it can slow progression of the disease while patients are still able to function.The Phase I study of 16 Alzheimer's patients tested gantenerumab at two doses against a placebo over six months of treatment.The Roche drug led to a dose-dependent reduction of brain amyloid, while amyloid load increased in patients receiving a placebo, the report said.The next step will be to investigate whether removal of brain amyloid translates into clinical benefit for patients at doses of the experimental drug that are well tolerated and safe, the report said.Much larger trials and further study will be needed to fully understand how gantenerumab works and whether it can stave off Alzheimer's, said the report.Roche is approaching the disease far earlier because amyloid accumulates for 15 years before dementi.

WASHINGTON, Dec. 21 (Xinhua) -- New research suggests that, in people who don't currently have memory problems, those with smaller regions of the brain's cortex may be more likely to develop symptoms consistent with very early Alzheimer's disease.The study was published Wednesday in the online issue of Neurology, the medical journal of the American Academy of Neurology.For the study, researchers used brain scans to measure the thickness of regions of the brain's cortex in 159 people free of dementia with an average age of 76. The brain regions were chosen based on prior studies showing that they shrink in patients with Alzheimer's dementia.Of the 159 people, 19 were classified as at high risk for having early Alzheimer's disease due to smaller size of particular regions known to be vulnerable to Alzheimer's in the brain's cortex, 116 were classified as average risk and 24 as low risk. At the beginning of the study, participants were also given tests that measured memory, problem solving and ability to plan and pay attention. The tests will go on over the next three yearsThe study found that 21 percent of those at high risk experienced cognitive decline during three years of follow-up after the MRI scan, compared to seven percent of those at average risk and none of those at low risk."Further research is needed on how using MRI scans to measure the size of different brain regions in combination with other tests may help identify people at the greatest risk of developing early Alzheimer's as early as possible," said study author Bradford Dickerson, of Massachusetts General Hospital in Boston and a member of the American Academy of Neurology.

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