Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Aqua Dots Toys Recalled Over Poisoning Concerns
Millions of Chinese-made Aqua Dots toys are being recalled in North America because they contain a chemical that can turn into the dangerous "date rape" drug gammahydroxybutyrate (GHB) when ingested, the Toronto Star reported.
Aqua Dots are liquid-filled beads that can be arranged into designs that hold together when the beads are sprayed with water.
WHAT TO KNOW
The recall by Toronto-based Spin Master follows the withdrawal of the same toy from store shelves in Australia (where it's called Bindeez), after three children were hospitalized due to swallowing some of the beads. An overdose of GHB can cause seizures, coma or even death.
The U.S. Consumer Product Safety Commission said it's received two recent reports of children swallowing Aqua Dots. A 20-month-old child who swallowed several beads became dizzy, vomited several times and slipped into a coma for a brief period. He was hospitalized and has since recovered. A second child who swallowed some beads also vomited, lapsed into a coma, and was hospitalized for five days.
In a statement, Spin Master said it's asking retailers across North America to halt sales of Aqua Dots, which had been considered one of the hottest new toys this holiday season, the Star reported.
The CPSC advised consumers to immediately take these toys away from children and to contact Spin Master toll free at (800) 622-8339 for free replacement beads or a toy of equal value.
Scientists Identify Cancer Stem Cell in Dogs
U.K. researchers have identified a cancer stem cell in dogs that could help lead to new treatments for bone cancer in children. Osteosarcoma in dogs is molecularly similar to bone cancer in children, reported BBC News, citing the scientists at the Royal Vet School at the University of Edinburgh.
The cancer stem cell they identified makes copies of osteosarcoma, enabling the disease to spread throughout the body, BBC News reported. By identifying this form of stem cell -- which appears to be highly resistant to treatment -- it may be possible to develop methods of targeting it.
The study appears in The Veterinary Journal.
"The rogue cancer stem cell is key in the whole process," said researcher Professor David Argyle. "We identified it by growing cells in particularly harsh conditions but, whereas other cancer cells died off, this stem cell was able to survive."
This finding offers evidence to support the growing theory that faulty stem cells fuel the development of certain types of cancers, Henry Scowcroft, senior cancer information officer at Cancer Research UK, told BBC News.
But he noted that this "finding came from studies of cancer in dogs so it remains to be seen whether it holds true in humans."
Experimental HIV Vaccine May Increase Infection Risk
An experimental HIV/AIDS vaccine made by Merck seemed to actually increase the risk of HIV infection among study volunteers, according to data presented at a scientific meeting in Seattle, The New York Times reported.
HIV is the virus that causes AIDS.
Results from tests on 3,000 people at high risk of HIV infection found that 49 of those who received the vaccine became infected, compared to 33 of those who received a placebo. Vaccinated volunteers at greatest risk for HIV infection were those with pre-existing levels of immunity to a common cold virus called adenovirus type 5, which was modified to become a component of the HIV/AIDS vaccine.
Researchers suggested that the cold virus may activate the immune system in a way that makes certain vaccine recipients more susceptible to HIV infection, the Times reported.
"The new analyses are both disappointing and puzzling," because they don't provide an explanation for the vaccine's failure, said Dr. Anthony S. Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases. The agency was a partner in the trial of the vaccine, which many experts believed held great promise.
In late September, Merck stopped the vaccine trial because it failed in two key areas -- it didn't prevent infection and it didn't lower the amount of HIV in the blood of infected patients, the Times reported.
Anti-Smoking Vaccine Shows Promise
An anti-smoking vaccine that eliminates smokers' addictive nicotine buzz shows promise, according to a study presented at an American Heart Association conference.
The U.S. study of 301 longtime smokers found that about 15 percent of those who received NicVAX stopped smoking after one year, compared to about 6 percent of volunteers who received a placebo, the Associated Press reported.
The results are comparable to some currently available smoking-cessation aids. But the vaccine -- designed to prevent nicotine from reaching the brain -- takes a different approach than gums, lozenges, patches, and nasal sprays designed to help smokers quit.
"It clearly shows promise" and warrants further study, said Dr. Frank Vocci, director of medications development at the U.S. National Institute on Drug Abuse, which has helped fund the vaccine's development, the AP reported.
Some experts were unimpressed with the study results.
"I'm a little underwhelmed," Dr. Timothy Gardner, an AHA spokesman and cardiologist at Christiana Care Health System in Newark, Del., told the AP. " I would think we could expect better," he said.
Vitamin D May Slow Aging
Vitamin D -- produced naturally by the body through exposure to sunlight -- may help slow the aging of cells and tissues, say researchers at King's College London.
They studied 2,160 women, ages 18 to 79, and found that those with higher levels of vitamin D in their blood had fewer age-related changes in their DNA, BBC News reported.
However, the study -- published in the American Journal of Clinical Nutrition -- did not prove a direct cause and effect between vitamin D levels and aging.
"These results are exciting because they demonstrate for the first time that people who have higher levels of vitamin D may age more slowly than people with lower levels of vitamin D," said study leader Professor Brent Richards, BBC News reported.
"This could help to explain how vitamin D has a protective effect on many aging-related diseases, such as heart disease and cancer," Richards said.
Breastfeeding Doesn't Cause Saggy Breasts: Study
Contrary to what many women believe, breastfeeding does not cause saggy breasts, says a University of Kentucky study that included 132 women who sought breast lifts or augmentation. Most of the women had been pregnant at least once and nearly 60 percent had breastfed at least once.
Researchers analyzed each woman's medical history, height and weight, smoking habits, and pre-pregnancy bra cup size. They found no difference in extent of breast sagginess between women who'd breastfed and those who hadn't, BBC News reported.
However, the study authors did conclude that pregnancy itself was a factor. The degree of sagginess increased each time a woman was pregnant. Smoking was another factor that contributed to breast sagginess.
"Smoking breaks down a protein in the skin called elastin, which gives youthful skin its elastic appearance and supports the breast," said study author Dr. Brian Rinker, BBC News reported.
The study was presented an American Society of Plastic Surgeons meeting.