Health Highlights: July 3, 2006
Obesity Increases Risk of Mood Disorders Flu Vaccine Maker Warned by FDA Discovery Could Change Treatment of Sleep Disorders Scientists Design Artificial Limbs That Fasten to Skeleton Experts: Bird Flu Vaccine 10 Years Away
Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
Obesity Increases Risk of Mood Disorders
People who are obese are 25 percent more likely to have a mood disorder, but they are also 25 percent less likely to have substance abuse problems, a new study finds.
The research, published in Monday's issue of the Archives of General Psychiatry, looked at more than 9,000 adults who were interviewed as part of a large, national survey on mental disorders. Of those questioned, 2,330 were considered obese because they had a body-mass index of 30 or higher. The findings were similar for both genders, although the link between obesity and mood disorders was strongest among non-Hispanic whites and those with higher levels of education.
"This calculation illustrates the public health importance of the association but does not indicate a direction for the causal relationship," the Seattle researchers wrote. "It is equally correct to state that more than one-fifth of cases of mood disorder in the general population are attributable to the association with obesity."
About 31 percent of all U.S. adults were obese in 2000, the study showed, which was an increase of 23 percent from 1990. Previous studies have indicated a risk between obesity and depression, and other research has repeatedly shown that obese adults are at a higher risk for diabetes, cardiovascular disease and other harmful conditions.
Flu Vaccine Maker Warned by FDA
Drug maker Sanofi Pasteur was issued a warning letter by the U.S. Food and Drug Administration on Monday following concerns that arose after some batches of the company's influenza vaccine failed sterility tests this spring.
According to the Associated Press, the FDA has inspected the company's Swiftwater, Pa.-based plant and none of the affected material was used in any vaccines. No further problems have occurred since then, the wire service reported.
However, the warning letter was issued because the source of the contamination has not been found, the FDA said.
Since the letter is only an advisory, Sanofi Pasteur can continue to make vaccine at the Pennsylvania plant, Dr. Karen Midthun, deputy director of the FDA's Center for Biologics Evaluation and Research, told the wire service. The company said in a statement that it is working closely with the government to address any concerns, and it is still confident it can manufacture roughly 50 million doses of flu vaccine for the upcoming flu season.
Discovery Could Change Treatment of Sleep Disorders
A gene that regulates sleep works much differently than first thought, new research shows.
A report in Monday's online issue of the Proceedings of the National Academy of Sciences suggests that treatments for jet lag, insomnia and sleep problems related to disruptions in the body's circadian clock might need to be reworked in light of the findings.
Until now, scientists have believed that a mutation in the CK1 gene known as the tau mutation slowed the gene's activity and allowed the body clock to speed up. But researchers from the University of Michigan and University of Utah say the mutation actually slows the gene's activity.
The scientists said they plan to develop a mouse model so they can start to test ways to regulate the body clock based on the discovery, a necessary step before any new drugs could be developed to treat sleep disorders.
Scientists Develop Artificial Limbs That Fasten to Skeleton
In a breakthrough that could help amputees worldwide, researchers at University College of London say they have found a way to allow a prosthesis to breach human skin and attach directly to bone.
The development could pave the way for bionic limbs that could be controlled by the central nervous system, the BBC reported Monday. Until now, the risk of infection passing from the external prosthesis directly into the bone has meant that amputees now have to strap an artificial limb to what is left of the arm or leg. The results of preliminary trials, conducted on patients who had lost thumbs or fingers, will be published in an upcoming issue of the Journal of Anatomy.
The British team that developed the technique, called Intraosseoius Transcutaneoius Amputation Prosthesis (ITAP), noted that the risk of infection is lowered because a titanium rod is implanted in the bone and skin tissue then grows around the rod and forms a seal. To figure out how to attach living tissue to metal, the scientists studied how deer antlers burst through skin without infection.
Zafar Khan, chairman of the Limbless Association, told the BBC that, "As an amputee, residual limbs are currently inserted into a socket, to which a prosthetic limb is attached. And when you walk or use the limb there is a movement and that causes rubbing and pressure sores. The real benefit is that this would not happen with the new technique. But on the downside, I would still be worried about infection."
Experts: Bird Flu Vaccine 10 Years Away
Experts meeting at a bird flu summit in Paris said that the H5N1 virus is proving a difficult target for vaccine research, and that a viable vaccine could be 10 years away.
Vaccine researcher Dr. David Fedson, a former professor of medicine at the University of Virginia School of Medicine, said H5N1 was proving very difficult to grow in culture, according to a BBC report. Researchers were also finding it tough to stimulate an immune system response in humans that would be strong enough to defend against the virus, he said.
"H5N1 is so poorly immunogenic and replicates so poorly that we could immunize globally, with six months of production, about 100 million people," Fedson told the BBC. Compared to the 300 million doses of seasonal flu manufactured each year, the number would be far too small. "From a public health point of view, this is catastrophic," he said.
In related news, a report issued Friday by U.S. Health and Human Services Secretary Mike Leavitt announced that the United States in May sent an undisclosed amount of the antiviral flu drug Tamiflu to a secure location in Asia, where it could be used in the event of an outbreak of bird flu.
As reported by the Associated Press, Levitt said the Tamiflu "could be used as part of the international community's efforts to contain a pandemic. However, if containment was not possible, the Tamiflu could be sent back to the U.S. stockpile of antiviral influenza medications."
The H5N1 avian flu virus -- which has so far failed to mutate into a form that is easily transmitted between humans -- has infected 228 people in 53 countries so far, mostly from bird-to-human contact. Half of those infected have died.