Genes linked to high altitude life
Tibetans’ ability to survive at high altitude without getting sick has been linked to genes for the first time in a study published in Science.
Tibetans live in one of the highest regions of the world yet do not experience the symptoms associated with low levels of oxygen found in these high altitudes.
Scientists have found 10 genes that could explain why Tibetans living on Mountaintops don’t get sick
By comparing the genes of 31 Tibetans with a group of 90 Japanese and Chinese lowland people, scientists discovered 10 genes linked to a resistance to altitude sickness. Two of these genes have been linked to haemoglobin, the component in blood, which carries oxygen around the body.
Scientists have long known that Tibetans produce a low number of red blood cells but it is not understood how the body survives on such decreased levels of oxygen. By doing so, doctors predict it will help to understand and treat altitude sickness in mountaineers and other illnesses.
“What’s unique about Tibetans is they don’t develop high red blood cells counts,” said Professor Josef T. Prchal, a senior author on the study. “If we can understand this, we can develop therapies for human disease.”
The study was a joint collaboration between researchers at the University of Utah and Qinghai University Medical School.
Smallpox vaccine helped to curb AIDS?
Ending the worldwide smallpox vaccination may have lead to the explosive spread of HIV, scientists in a new study have suggested.
Smallpox immunisation gradually stopped between 1950s and 1970s, and since then, the rates of HIV have increased around the world.
The researchers from the study analysed white blood cells taken from people recently immunised against smallpox. They found that HIV replicated at lower levels from the vaccinated group compared with those from a control group who had not been immunised against smallpox.
According to the research, the smallpox vaccine cut HIV replication five-fold.
“There have been several proposed explanations for the rapid spread of HIV in Africa, including wars, the reuse of unsterilised needles and the contamination of early batches of polio vaccine. However, all of these have been either disproved or do not sufficiently explain the behaviour of the HIV pandemic,” said Dr Raymond Weinstein the lead researcher of the study, from the George Mason University in Virginia.
Mobile phones - no risk of brain tumours, scientists say
The largest study of mobile phone usage has found no link to suggest it increases the risk of brain tumours although the results are inconclusive, scientists report.
The study, carried out between 2000 and 2004, involved interviewing thousands of people from 13 countries about mobile phone usage and health.
The researchers compared the results from a group of patients suffering from either glioma or meningioma (types of tumour) with a similar number of health adults acting as a control group. No children took part in the study.
“Overall, this research has not shown evidence of an increased risk of developing a giloma or meningioma brain tumour as a result of using a mobile phone,” said Patricia McKinney an epidemiologist at the University of Leeds and one of the leaders of the study.
“The balance of evidence from this study, and in the previously existing scientific literature, does not suggest a causal link between mobile phone use and risk of brain tumours,” said Anthony Swerdlow, an epidemiologist at the Institute of Cancer Research and one of the leaders of the study.
Along with the other authors of the study, he warns that this does not provide assurances that there are no health risks associated with mobile phone usage: “The duration of phone use for which we yet have evidence is currently limited, however, and we have virtually no information for use of mobile phones for longer than 15 years.”
Sleep study - too much or too little
Sleeping fewer than six hours each night leads to a higher chance of dying prematurely, a new study has found. But consistently getting too much sleep may increase the risk of developing fatal illnesses the researchers found after analysing 1.3 million participants over 25 years.
“While short sleep may represent a cause of ill-health, long sleep is believed to represent more an indicator of ill-health,” said Francesco Cappuccio, leader of the Sleep, Health and Society Programme at the University of Warwick.
“Modern society has seen a gradual reduction in the average amount of sleep people take, and this pattern is more common amongst full-time workers, suggesting that it may be due to societal pressures for longer working hours and more shift-work,” added Cappuccio.
The study, a collaboration between the University if Warwick and the Federico II University Medical school in Naples, is published in the Sleep journal.
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