Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Study Identifies Brain Chemical Involved in Exercise "High"
Yale University scientists have identified a brain chemical associated with the natural "high" of exercise and suggest that a drug based on that chemical could provide an effective treatment for depression, BBC News reported.
The researchers found that a gene called VGF -- located in the brain's hippocampus -- is more active during exercise. The gene is linked to a growth factor chemical involved in the development of nerve cells.
- Study Identifies Brain Chemical Involved in Exercise "High"
- Cancer Cells Softer Than Normal Cells
- China Reports 17th Bird Flu Victim
- Genes Linked to Psoriasis and Lupus Identified
- Food Chemicals May Increase Risk of Ovarian and Endometrial Cancers
- Guidelines Due on Childhood Obesity
The Yale team then made a version of this chemical and tested it in mice. It seemed to affect the rodents' behavior in a way somewhat similar to the way antidepressants affect humans, BBC News reported.
The research appears in the journal Nature Medicine.
Cancer Cells Softer Than Normal Cells
The surfaces of living cancer cells are more than 70 percent softer than those of healthy cells, says an American study in the journal Nature Nanotechnology. The softer surfaces were detected in lung, breast and pancreatic cancers.
The finding by University of California, Los Angeles scientists could help increase detection of cancer cells that might otherwise escape notice, Agence France-Presse reported.
For this study, the researchers collected body fluid from suspected cancer patients and used atomic force microscopes to apply pressure to individual cells. The cells' surfaces were tested using a sharp probe attached to a mechanical arm.
"Our work shows that mechanical analysis can distinguish cancerous cells from normal ones even when they show similar shapes," the researchers concluded. They said the increased softness that occurs when normal cells become cancerous makes it easier for cancer cells to spread to other parts of the body, AFP reported.
China Reports 17th Bird Flu Victim
China has reported its 17th human victim of H5N1 bird flu, the country's official Xinhua news agency said Monday.
The 24-year-old man died Sunday at a hospital in southern province of Jiangsu. The news agency said tests confirmed that the man was infected with the H5N1 virus, the Associated Press reported.
The victim had no known contact with infected poultry, and there have been no reported outbreaks of bird flu in Jiangsu province.
The H5N1 virus first appeared in 2003 and remains a dangerous threat throughout Indonesia and in parts of Bangladesh, China, Egypt, Nigeria and Vietnam, the AP reported.
Genes Linked to Psoriasis and Lupus Identified
Genes linked to psoriasis and lupus have been identified by scientists. These new findings appear online in the journal Nature Genetics.
Learning more about genes associated with these diseases may help in the development of new treatments.
In one study, researchers led by John Armour of the University of Nottingham in Britain found that people with the skin disease psoriasis had significantly more copies of a gene called beta-defensin. It's known that this gene can trigger skin inflammation in response to infections, Agence France-Presse reported.
In the second study, American and British researchers found that people with a specific genetic variation near a gene called TNFSF4 had an increased risk of developing lupus.
The genetic variation appears to boost expression of TNFSF4 among blood lymphocytes in people with lupus, the scientists said. Lymphocytes are white blood cells that, under direction of the immune system, attack foreign objects in the body, AFP reported.
Food Chemicals May Increase Risk of Ovarian and Endometrial Cancers
Women who consume foods with high levels of acrylamides every day may double their risk of ovarian or endometrial cancer, according to Dutch researchers who surveyed 120,000 people (including 62,000 women) about their eating habits and followed them for 11 years, BBC News reported.
Acrylamides are chemicals formed when food is fried, grilled or roasted.
During the 11 years, 327 of the female participants developed endometrial cancer and 300 developed ovarian cancer. After analyzing the data, the University of Maastricht researchers concluded that women who ate 40 micrograms of acrylamide a day were twice as likely to develop these two types of cancer as women who consumed much less acrylamide.
A single package of potato chips or a serving of french fries would contain about 40 micrograms of acrylamide, BBC News reported.
Although this was a large study, the researchers said their findings need to be confirmed by additional research.
It's difficult to determine whether the increased cancer risk among some women was due to acrylamides or other unhealthy foods in their diets, said Dr. Lesley Walker of Cancer Research UK.
"Women shouldn't be unduly worried by this news. It's not easy to separate out one component of the diet from all the others when studying the complex diets of ordinary people," Walker told BBC News.
Guidelines Due on Childhood Obesity
Annual weight checks, counseling about weight, and a four-stage treatment plan are among the points included in new guidelines for preventing and treating childhood obesity in the United States, USA Today reported.
The guidelines, prepared by a panel of medical experts convened by the American Medical Association and government agencies, are to be published in the journal Pediatrics.
About 17 percent of American children are obese, which is triple the percentage in 1970, the guideline authors said. Children with excess weight are at increased risk for diabetes, high blood pressure, heart disease and stroke.
Among the recommendations:
- Weight counseling should be given for both overweight and normal-weight children at every checkup. Doctors should check cholesterol levels of overweight children.
- Children need to get an hour of physical activity every day, and there should be limits on their computer and TV time, and on their consumption of sweetened beverages and fast food.
- Doctors should gather children's family history of obesity, diabetes and heart disease.
- A four-stage treatment plan for overweight children could include medication or surgery for the most persistently obese youngsters.
The new, aggressive guidelines "are long overdue," Melinda Sothern, a pediatric obesity specialist at Louisiana State University Health Sciences Center, told USA Today. "Lots of parents are frustrated because there are no specific guidelines for treating overweight children."