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RISK FACTORS FOR CHILDHOOD INJURY
There are three key risk factors for childhood injuries, researchers
say. They are the child being impulsive or having unrealistic expectations of his physical
prowess and lack of parental control and monitoring. The study was done at the University
of Alabama at Birmingham. "Pediatric psychologists have much to contribute in the
battle to prevent children's unintentional injuries," said David Schwebel, assistant
professor of psychology. "But to approach injury prevention from an educated
viewpoint, we must gain a thorough understanding of the psychological factors that lead
children to injure themselves." Injuries are the leading cause of death in children
ages one to 18. Each year more than 20 million children are injuried, and 22,000 die from
their injuries, says the National Safety Council. Behavioral scientists say the greatest
risk is faced by children who are impulsive, overactive and uncontrolled, who think they
are physically more capable than th! ey really are and whose parents fail to provide
proper supervision and rules of safety. The new study looks at how the three factors
interact to increase the risk of accidents.
THE GENES OF LONGEVITY
Scientists have identified the location of genes that are associated
with a long life. The team pinpointed them to a region on human chromosome 4. "This
is the first study to use humans to try to find genes that play a role in life span,"
said Dr. Thomas Perls, a co-authors, geriatrician at Beth Israel Deaconess Medical Center
in Boston and director of the New England Centenarian Study. "Many investigators
thought longevity was far more complex a trait that wouldn't be influenced by just a few
genes." Scientists said they have known that only a handful of genes influences
longevity in lower organisms; now they think that may be true for humans as well. One in
10,000 Americans is a centenarian, topping the average life expectancy by 20 years.
Despite their rarity, centenarians are the fastest growing segment of the U.S. population,
Perls said. Scientists had thought about 1,000 genes influence aging, but the region on
chromosome 4 has only one or at most a! few genes that are related to longevity,
researchers said. The next step is to identify these genes.
GENETIC MUTATIONS AND HIV
People with a copy of a mutation that protects cells against HIV
infection may be partially resistant to the virus that causes AIDS, scientists say. The
finding is reported in the Journal of Acquired Immune Deficiency Syndrome by teams from
New York City, Boston, Seattle and San Francisco. "We looked for this mutation in a
large cohort of high-risk people who were HIV-negative. We found that bisexual and
homosexual Caucasian men with one copy of the mutation had a 70 percent reduced risk of
HIV infection compared with men who didn't carry the mutation at all," said study
author Michael Marmor, professor of environmental medicine and medicine at New York
University School of Medicine. Scientists have known that men with two mutant copies of
the CCR5 gene have stronger resistance to HIV infection. "Our finding suggests that
strategies to prevent HIV infection by blocking receptors used by the virus need not block
all of the receptors," Marmor said. "Reducin! g the number of receptor sites per
cell may be adequate to provide an imperfect but important degree of protection."
CAUTION ABOUT IMPLANTED HEART DEVICES
Implanted heart devices are prone to silent, dangerous staph
infections, doctors caution. These include pacemakers and other devices implanted to
prolong the lives of people with heart rhythm problems. A staph infection, however, could
be life-threatening in these patients, scientists said in the journal Circulation.
"If a patient has an implanted cardiac device and develops a Staphylococcus aureus
infection, the patient's physicians should be worried that the device is infected,"
said Dr. Donna Lisa Chamis of Duke University Medical Center in Durham, N.C. "Our
data suggest that if the infection occurs within one year of implantation, the device ends
up being infected in about three-fourths of the cases. The major new finding is that the
majority of the device infections showed no obvious signs." In the study, most of the
infections started in another part of the body, then spread to the heart device, the
researchers said. The heart device itself was link! ed directly to the staph infection in
18 percent of cases.