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health FRIDAY, APRIL 12, 2013
RESEARCH
BREAKTHROUGH
Next gen Alzheimer’s mouse model created
‘Space travel may up colon cancer risk’ These findings have implications for the health of astronauts undertaking exploratory missions into outer space and for future space tourists, experts say. WASHINGTON: Space travel may increase the risk of colon cancer, a new study led by Indian-origin scientists has warned. Researchers, from Georgetown Lombardi Comprehensive Cancer Center, found that cosmic radiation impairs the ability of cells in the intestines of mice to eliminate oncogenic proteins, thus substantially increasing development of colorectal tumours. The study funded by NASA is important because it might provide a direction for researchers in designing strategies to protect space travellers against increased cancer risk, said the scientists, Shubhankar Suman and Kamal Datta. “While there is no reliable estimate of colorectal cancer risk from space radiation exposure, we have shown that exposure to cosmic radiation causes markedly increased intestinal tumours in mice,” said Datta, an assistant professor in the department of biochemistry and molecular and cellular biology. “These findings have implications for the health of astronauts undertaking exploratory missions into outer space and for future space tourists,” he said in a statement. “Our objective is to develop a risk estimate based on mouse model studies and to identify molecular mechanisms contributing to it, so that we can develop strategies to protect astronauts during long duration space missions, such as one to Mars,” said Lombardi Fornace, director of the NASA programme at Georgetown.
Researchers used specialised mutant mice to study the effects of 56Fe radiation, a highly ionising radiation prevalent in space that can cause DNA damage. Both researchers used specialised mutant mice to study the effects of 56Fe radiation, a highly ionising radiation prevalent in space.
“This radiation is considered the greatest challenge for space exploration. It deposits higher amount of energy in the body than does the gamma-/xrays causing relatively higher DNA damage. This is believed to increase carcinogenic risk in astronauts, although accurate risk estimates are not yet available,” said Datta. Researchers also report that 56Fe radiation significantly increased colorectal cancer risk in mouse models of colorectal cancer through enhanced activity of beta-catenin, an oncogene that activates expression of pro-
growth genes in the colon. In his study, Datta reports that tumour formation in mouse intestines after exposure to cosmic radiation, unlike after exposure to gamma radiation, was dose dependent. “Sustained exposure during prolonged space missions such as a mission to Mars and lengthy stays at the International Space Station may cause significant cosmic radiation dose accumulation in astronauts and thus remains a long-term health concern of space exploration,” said Datta. PTI
LOS ANGELES: Scientists have developed a new genetically engineered lab rat that has the full array of brain changes associated with Alzheimer’s disease. The new mouse model supports the idea that increases in a molecule called beta-amyloid in the brain causes the disease, according to the study published in the Journal of Neuroscience. “We believe the rats will be an excellent, stringent pre-clinical model for testing experimental Alzheimer’s disease therapeutics,” said Terrence Town, the study’s senior author from the University of Southern California Keck School of Medicine, Los Angeles. Alzheimer’s is an age-related brain disorder. Pathological hallmarks of Alzheimer’s brains include abnormal levels of betaamyloid protein that form amyloid plaques; tau proteins that clump together inside neurons and form neurofibrillary tangles; and neuron loss. Additionally, glial cells, which normally support, protect, or nourish nerve cells , are overactivated in Alzheimer’s. Plaque-forming beta-amyloid molecules are derived from a larger protein called amyloid precursor protein (APP). One hypothesis states that increases in beta-amyloid initiate brain degeneration. Town and his colleagues decided to work with a certain strain of rats. “We focused on Fischer 344 rats because their brains develop many of the age-related features seen in humans,” said Town in a statement by National Institute of Neurological Disorders and Stroke (NINDS) in the US. The researchers performed a variety of experiments confirming the presence of neurofibrillary tangles in brain regions most affected by Alzheimer’s. PTI
STUDY
Men more distant in relationships LONDON: Women immerse themselves in their romantic relationships, while men place their romantic partners and best friends on an equal but distant footing, a new Oxford study has found. The research by Dr Anna Machin and Professor Robin Dunbar from the University of
Oxford studied a total of 341 people.,The participants took part in online psychological research forum, where they answered questions regarding the maintenance, role and value of their best friend and romantic partnerships. Women saw the maintenance of their romantic partner-
ships as a team sport, involving equal input from both partners with shared goals and beliefs being the key to success. Further, their happiness and contentment were intimately bound up in both their best friendships and romantic partnerships. In contrast, men were found
to exist at a greater distance from both of their closest relationships. Women preferred cooperation not competition with their best friends. They also scored their partner consistently higher than themselves, seemingly placing their partner on a pedestal. PTI