Swiss researchers looked at almost 200,000 operations, finding an 8 percent increase in the chance of failure when male kidneys were given to women.

Women who get a replacement kidney from a male donor are more likely to reject the new organ, scientists suggest.
Swiss researchers looked at almost 200,000 operations, finding an 8 percent increase in the chance of failure when male kidneys were given to women, BBC reported.
Writing in The Lancet medical journal, they suggested same-sex transplants should be considered in future.
However, the UK Transplant Authority said its own research had not found any gender difference. The idea of the ’sex’ of donor tissue influencing how it is received by the recipient’s immune system is not a new one.
In stem-cell transplants, men who get cells from a female are at an increased risk of dangerous “graft-versus-host“ disease, and women who get ’male’ cells are more likely to reject them, or have an immune reaction to molecules specific to males found on the surface of cells.
The researchers from the University Hospital in Basel examined the outcome of a total of 195,516 transplants between 1985 and 2004 at more than 400 hospitals in Europe.
They found that “graft loss“--the rejection of the new organ--was more likely in kidneys from female donors than those from male donors after both a year and 10 years. The biggest difference was the transplantation of male kidneys into female recipients, where the chances of failure in the first year were 11 percent higher than average, and 8 percent more likely overall.

A new study shows that green tea, the beverage which is more popular in eastern cultures, can protect heart arteries by keeping them flexible and relaxed, and therefore better able to withstand the ups and downs of constant changes in blood pressure.
Led by Dr. Nikolaos Alexopoulos of Athens Medical School in Greece, the researchers found that among 14 subjects, those who drank green tea showed greater dilation of their heart arteries on ultrasound 30 min. later than those drinking either diluted caffeine or hot water, Time said.
That’s because, the scientists speculate, green tea works on the lining of blood vessels, helping cells there to secrete the substances needed to relax the vessels and allow blood to flow more freely. It’s the flavonoids in the tea, which work as antioxidants and help prevent inflammation in body tissue, that keep the vessels pliable.
These substances may also protect against the formation of clots, which are the primary cause of heart attacks. “We found very promptly [that] after drinking green tea, there was a protective effect on the endothelium,“ says Dr. Charalambos Vlachopoulos, a cardiologist and one of the authors of the study.
All it took, says Vlachopoulos, was six grams of green tea, which amounts to three to four cups.
To make sure the dilation effect was not due to the small amounts of caffeine found in green tea; the group compared the arterial sizes in the green-tea drinkers with those consuming a diluted caffeine beverage and found no change in arterial size in the caffeine drinkers. Even more intriguing, the beneficial effect seems to be long-lasting and cumulative.
When the doctors measured the green-tea drinkers’ arteries two weeks after daily consumption of the beverage, they found that their vessels were more dilated than they had been at the beginning of the study.
“It’s something that needs to be investigated, but we think that if someone takes green tea for one or two months, the beneficial effect will be even greater,“ says Vlachopoulos.

Babies born to women with low levels of vitamin D during pregnancy may be at increased risk for tooth enamel defects and early childhood tooth decay, a Canadian study finds.
According to HealthDay, researchers at the University of Manitoba analyzed the vitamin D levels of 206 women in their second trimester of pregnancy and found only 21 (10.5 percent) of the women had adequate vitamin D levels. The women’s levels of vitamin D were related to the frequency of milk consumption and prenatal vitamin use.
The researchers also examined 135 infants and found that 21.6 percent of them had enamel defects and 33.6 percent had early childhood tooth decay. Mothers of infants with enamel defects had lower, but not significantly different, mean vitamin D concentrations during pregnancy than mothers of infants without enamel defects.
Mothers of infants with early childhood tooth decay had significantly lower vitamin D levels than mothers of cavity-free infants. Infants with enamel defects were significantly more likely to have early childhood tooth decay, the researchers said.
The study, expected to be presented July 6 at the General Session of the International Association for Dental Research, in Toronto, is the first to show that pregnant women’s vitamin D levels may affect the dental health of their infants.

Airplanes are visually inspected everyday, but tiny cracks and flaws on planes can be easily missed. Now, a new kind of paint could expose hidden damage on planes.
Undetected damage, like tiny cracks, flaws or weak points, is a big problem on airplanes, Ivanhoe reported.
Now, chemists are testing a new paint that changes color to instantly reveal damage on planes.
“So, it’s tuned to be able to release a dye to be able to change different color based on the level of impact,“ Dr. Bryan Koene of Luna Innovations said.
Microcapsules containing a colored dye are mixed together with aircraft paint. If the paint is scratched, dented, or struck the capsules break, releasing the dye. The change in color pinpoints damage. Visual inspections are easier and more accurate.
“This technology is important because it enables detecting damage very simply and cheaply,“ Dr. Koene said.
The new paint is being developed first for the military. Next, it will be used on commercial and private planes.