Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
Gene Linked To Liberalism: Study
People with a certain gene variation are more likely to be liberal, but only if they had lots of friends in high school, according to a new study.
Researchers at Harvard University and the University of California, San Diego, analyzed data from almost 2,600 teens who took part in the National Longitudinal Study of Adolescent Health, which gathered details about participants' genes, friends and their political beliefs later in life, the Washington Post reported.
The results showed that teens with the "7R" version of the DRD4 gene were more likely to liberal when they became adults.
The DRD4 gene is associated with the brain chemical dopamine, which helps control emotional responses and the ability to experience pleasure and pain. Previous research has linked the gene to risk-taking behavior, the Post reported.
The study appears in The Journal of Politics.
The DRD4 gene may make people more open to new experiences, including learning about other people's points of views. This would expose them to a "wider diversity of viewpoints" and lead to their liberalism, the researchers suggested, the Post reported.
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Chances Of IVF Success Level Off After Third Try: Study
Repeated attempts at getting pregnant through in vitro fertilization (IVF) don't necessarily improve the chances of having a baby, finds a new study.
U.S. researchers looked at about 300,000 women who had more than half a million IVF cycles over five years and found that the live birth rate was 36 percent on the first IVF, 48 percent on the second attempt and 53 percent on the third try, the Associated Press reported.
However, the rate among women who tried seven or more times was 56 percent, justly slightly better than 53 percent success rate after three tries.
"Don't quit if the first cycle isn't successful. Your chances go up with the second cycle," said lead researcher Barbara Luke of Michigan State University, the AP reported. But she added that "if you haven't gotten pregnant by the third, the chances are slim to continue."
The study was presented Wednesday at a reproductive medicine meeting in Denver.
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U.S. Army Funds Suicide Prevention Research
The U.S. Army is funding a three-year, $17 million project to determine the effectiveness of suicide prevention programs.
The research was prompted by the rising number of suicides in the military. Between 2005 and 2009, more than 1,100 U.S. military personnel committed suicide, the Associated Press reported.
The project will involve creation of a global network of researchers to study suicide. A large database will then be compiled so that people running prevention programs can see which methods are effective.
Current suicide prevention approaches are based on "good ideas" from experts, but there's no actual proof they work, said Col. Carl Castro, director of an Army medical research program, the AP reported.
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Taller Men May Be Likelier to Get Testicular Cancer: Study
Taller men may be at increased risk for testicular cancer, according to a new study.
U.S. National Cancer Institute researchers analyzed data from more than 10,000 men and concluded that for every extra 2 inches above average height, the risk of testicular cancer increased 13 percent, BBC News reported.
It's not clear why increased height boosts the risk of testicular cancer, said the researchers. The study appears in the British Journal of Cancer.
"Tall men should not be alarmed by this research since fewer than four in 100 testicular lumps are actually cancerous," Sara Hiom, director of health information at Cancer Research U.K., told BBC News. "But it is still important for men to be aware of any changes to the size and weight of their testicles and not delay seeing their GP if they are concerned. This is particularly true for young men as the disease is more common with under-35 year olds."
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Scientists Map 95 Percent of Human Gene Variations
About 95 percent of all human gene variations have been mapped, say the leaders of a project to sequence and compare the DNA of 2,500 people from around the world.
The members of the 1,000 Genomes Project also said their findings suggest that each person carries an average of 75 gene variations that may play a role in inherited disorders, BBC News reported.
The findings appear in the journal Nature.
The researchers said that mapping human genetic differences can help explain why some people may be more prone to inherited disease, and could lead to new treatments, BBC News reported.
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