Eye Disease

Gene causing glaucoma found

August 23, 2007

Researchers have identified two mutant forms of a single gene that are responsible for 99 percent of all cases of a common form of glaucoma, which is second only to cataracts as the leading cause of blindness in the world.

The genes cause a specific form of the disease called "exfoliative glaucoma," characterized by the buildup of a protein called elastin in the ducts that drain excess fluid from the eye. The subsequent buildup of fluid causes pressure on the optic nerve, eventually leading to blindness.

Between 10 percent and 20 percent of the population older than age 60 have some symptoms of exfoliative glaucoma, and 60 percent of those develop the full-fledged form.

Researchers at Uppsala University in Sweden and deCODE Genetics Inc. and National University Hospital, both in Reykjavik, Iceland, studied genetic material from 16,000 people in the two countries and reported results in the journal Science.

They found two different mutations in a gene called LOXL1. One mutation increased the risk by 26 times of developing exfoliative glaucoma; the second increased the risk eightfold. People with two copies of the high-risk mutation were 100 times more likely to develop the disorder.

Los Angeles Times

PHYSIOLOGY

Evolution of male facial appearance may be linked to sexual selection

Some cavemen were just too sexy for their shirt. Or pelt.

Men with strong jaws, broad cheekbones and good teeth may have been considered hunks eons ago, just as they are today, say paleontologists at the Natural History Museum in London.

Analyzing anatomical characteristics of modern-day skulls from the Raymond Dart Collection at University of the Witwaterstrand in South Africa, the researchers have determined that the faces of male Homo sapiens contain some interesting geometric differences compared with female faces. As men evolved, the length of their upper face -- from the upper lip to the brow -- got shorter, relative to the female face. This effectively exaggerated the size of the jaw and flare (or width) of the cheekbones and eyebrows.

At the same time, the canine teeth shrunk over time, making men appear less threatening to enemies but presumably more attractive to women.

One possible explanation for the variation could be sexual selection. That is, women found men with certain facial characteristics simply irresistible and chose them as mates.

"The evolution of facial appearance is central to understanding what makes men and women attractive to each other," lead author Eleanor Weston says in a news release. "We have found the distance between the lip and brow was probably immensely important to what made us attractive in the past, as it does now."

The findings appear in the online journal PloS ONE, published by the Public Library of Science. For the complete study, go to plosone.org/doi/pone.0000710.

Los Angeles Times

SUPPLEMENTS

Beta carotene, vitamins C and E do not prevent heart attack in women at risk

Supplements of the antioxidants beta carotene, vitamin C and vitamin E may be good for you, but a new study reports that they have no effect, either alone or in combination, in preventing heart attack, stroke or death among women at risk for cardiovascular disease.

Researchers randomly assigned more than 8,000 women to take regular doses of vitamin E, vitamin C, beta carotene or placebos, and followed them for more than nine years. All the women, whose average age was 60, either had had cardiovascular disease or were at high risk for it. During the nine years, 1,450 women had a heart attack, a stroke or cardiac surgery, and there were 395 deaths from heart disease.

Women in the vitamin E group had a slight decrease in disease compared with the placebo group, but it was not statistically significant. Neither beta carotene nor vitamin C had any statistically significant effect compared with placebo.

Combinations of the antioxidants had no effect either, except for a slight reduction in stroke among those taking vitamins C and E together. The study appears in the Aug. 13 issue of The Archives of Internal Medicine.

"While the individual supplements may not decrease risk," said Nancy R. Cook, the lead author and an associate professor of epidemiology at Harvard, "it does seem that diets high in fruits and vegetables that contain these antioxidants are helpful. It may be that we haven't identified the particular nutrients or combinations of nutrients that might be beneficial."

New York Times News Service

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