UPI NewsTrack Health and Science News - January 9, 2008 : Health

WASHINGTON, Jan. 9
Key bird flu infection factor found
WASHINGTON, Jan. 9 U.S. scientists have identified a key factor that determines the ability of influenza viruses to infect cells of the human upper respiratory tract.

The finding, published online in the journal Nature Biotechnology, explains how the H5N1 avian flu virus would have to change to spread through human populations, the National Institute of General Medical Sciences said in a release.

Although the H5N1 virus has infected several hundred people, person-to-person transmission has been limited. To trigger a widespread outbreak, the bird flu virus must infect the cells lining human noses and throats, the report said.

Ram Sasisekharan of the Massachusetts Institute of Technology said the virus can gain access only through a subset of the sugar molecules coating upper airway cells.

While the protein from human-adapted flu viruses favors the sugars dotting the cells of the nose and throat, the one from bird flu viruses opts for glycans on cells deeper in the respiratory tract. The findings suggest that for H5N1 bird flu virus to spread widely in humans, it must adapt so it can latch onto the umbrella-shaped glycans of the upper respiratory tract, the report said.

Long-term anxiety boosts heart risk
LOS ANGELES, Jan. 9 Intense, long-lasting anxiety increases heart attack risk by up to 40 percent, a U.S. study said.

The research, published in the Journal of the American College of Cardiology, said nervous, socially withdrawn people may have as much to worry about when it comes to their heart as those with Type A personalities.

"What we are seeing is over and beyond what can be explained by blood pressure, obesity, cholesterol, age, cigarette smoking, blood sugar levels and other cardiovascular risk factors," Biing-Jiun Shen, an assistant professor of psychology at the University of Southern California in Los Angeles, said Tuesday in a release.

Shen and his colleagues found that men who tested at the highest 15th percentile on any of four anxiety scales faced an increase in the risk of heart attack of approximately 30 percent to 40 percent.

The finding held true even after the findings were adjusted for standard cardiovascular risk factors, health habits and negative psychological and personality traits, the report said.

Meningitis vaccine works on infants
LONDON, Jan. 9 British researchers said a new meningitis vaccine produces immunity and appears to be safe for infants.

A University of Oxford study, published in JAMA, the Journal of the American Medical Association, tested the vaccine MenACWY on 421 healthy infants in Britain and Canada. The researchers said the vaccine produced immunity against four strains of meningococcal disease and was well tolerated by infants.

The new vaccine is not yet licensed for use in the United States.

Researchers said vaccine currently licensed for use in the United States is poorly immunogenic in infancy, when the highest rates of meningitis are observed.

An estimated 1,400 to 2,800 cases of invasive meningococcal disease occur in the United States each year. Ten percent to 14 percent of people who contract the disease will die, the report said.

Unlike the currently licensed vaccine, MenACWY uses a natural mutant of the diphtheria toxin.

Oldest cosmic explosion detected
AUSTIN, Texas, Jan. 9 U.S. astronomers detected a cosmic explosion that took place 7.4 billion years ago -- making it the oldest known short gamma-ray burst.

The explosion was discovered using NASA's Swift satellite and the Gemini Observatory, astronomers said Wednesday in a release.

"This discovery dramatically moves back the time at which we know short GRBs were exploding. The short burst is almost twice as far as the previous confirmed record holder," John Graham of The Johns Hopkins University said in a statement.

The discovery was presented this week at American Astronomical Society's 2008 winter meeting in Austin, Texas.

The astronomers said GRBs are among the most powerful explosions in the universe, releasing enormous amounts of energy in the form of X-rays and gamma rays. The report said a popular model suggests that most short GRBs occur when two neutron stars smash into each other and collapse into a black hole, ejecting energy in two counter-flowing beams.