Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
U.S. Orders Largest Beef Recall in History
In what is being billed as the largest beef recall in the United States, the U.S. Department of Agriculture Sunday ordered the recall of 143 million pounds of frozen beef produced by a California slaughterhouse that is the subject of an animal-abuse investigation.
The recall from the Chino-based Westland/Hallmark Meat Co., which provided meat to school lunch programs, affects beef products dating back to Feb. 1, 2006, according to an Associated Press report. There have been no reports of illnesses linked to the recalled meat, and USDA officials termed the health threat small.
Officials estimate that about 37 million pounds of the recalled beef went to school programs, but they believe most of the meat has already been eaten, according to Dr. Dick Raymond, USDA Undersecretary for Food Safety.
Most of the beef was sent to distribution centers in bulk packages, and the USDA was planning to work with the distributors to determine how much meat remains, the AP reported.
U.S. officials recently suspended operations at Westland/Hallmark after an undercover Humane Society video showed crippled and sick animals being shoved with forklifts. Felony and misdemeanor charges were filed last week against some employees of the company, and an official investigation continues.
Federal regulations call for keeping downed cattle out of the food supply because they may pose a higher risk of contamination from E. coli, salmonella or mad cow disease.
About 150 school districts around the nation have stopped using ground beef from Hallmark Meat Packing Co., which is associated with Westland. Two fast-food chains, Jack-In-the-Box and In-N-Out, said they would not use beef from Westland/Hallmark, the AP reported. Other chains, such as McDonald's and Burger King, said they do not buy beef from Westland.
-----
Heavy Cell Phone Use Increases Mouth Cancer Risk: Study
An Israeli study reports that people who use cell phones for many hours a day are 50 percent more likely to develop mouth cancer than those who never use cell phones, and that cell phone users in rural areas may be at increased risk for cancer because cell phones need to emit higher levels of radiation in order to make contact with fewer available antennas.
The Tel Aviv University study looked at 500 people with benign and malignant tumors of the salivary gland and 1,300 healthy people. People who used cell phones for many hours a day were 50 percent more likely to develop a tumor of the parotid gland than infrequent users, the Telegraph reported.
The parotid gland -- the largest salivary gland -- is located near the jaw and ear, where cell phones are typically held during use. The findings appear in the American Journal of Epidemiology.
Many previous studies have found no link between cell phone use and increased cancer risk. But the author of this new study noted that Israelis were quick to adopt cell phones and are exceptionally heavy users, the Telegraph reported.
-----
Disappointing Results for Anti-HIV/AIDS Gel
An anti-HIV/AIDS vaginal gel called Carraguard was ineffective in reducing rates of new HIV infection in a study of about 6,000 South African women, the Associated Press reported.
Researchers said one reason for the disappointing results may have been low use of the gel. Only 10 percent of the women said they used the gel as directed every time they had sex.
The women in the study randomly received either the Carraguard gel or a placebo gel. All the women received condoms and safe-sex counseling. At the end of the study, the rate of new HIV infection among women using the Carraguard gel was 3.3 per 100, compared with 3.7 per 100 among women using the placebo gel, the AP reported.
The study was funded by the U.S. Agency for International Development and the Bill & Melinda Gates Foundation.
The researchers did find that reported condom use doubled from 33 percent to 64 percent and there was a decline in the spread of other types of sexually-transmitted infections.
-----
FDA Proposes Changes to Drug Use Rules
Critics and proponents have plenty to say about proposed changes to FDA regulations covering unapproved use of medicines and medical devices, The New York Times reported.
Currently, FDA approvals of medicines and medical devices limit how companies can market the products. For example, a drug approved to treat only breast cancer cant be sold as a lung cancer treatment, even if some research suggests the drug may benefit lung cancer patients.
Under the proposed changes, companies would be allowed to give doctors copies of medical journal articles about product uses that haven't been approved or vetted by the FDA. In addition, companies would not have to promise to adequately test the unapproved use discussed in such articles, the Times reported.
Proponents say the proposed changes will benefit patients because doctors will be able to quickly learn about unapproved uses that could save lives. Critics say the move will compromise patient safety.
Public comments are being accepted about the proposed changes and the FDA will take the matter up for final consideration in 60 days.
-----
Ocean Species' Changes Seen in Global Warming, Scientist Warns
In the last century, coal miners brought canaries with them into the mine, because the birds were sentries for any change in the air supply. If the canary keeled over, the humans knew they had to get to the surface.
The new age "canaries" are sea snails called pteropods, the food supply for a great many sea species. These small creatures are undergoing physiological changes that may spell future catastrophe, according to a molecular ecologist who gave a report over the weekend to the annual meeting of the American Association for the Advancement of Science in Boston.
Gretchen Hofmann, associate professor of biology at the University of California at Santa Barbara, collected pteropods in Antarctica and noticed changes in their physical makeup. This may be caused by an increasingly acidic ocean because of increased carbon dioxide in the atmosphere, she said in a university news release.
"They (the pteropods) are harbingers of change," she said. "It's possible by 2050 they may not be able to make a shell anymore. If we lose these organisms, the impact on the food chain will be catastrophic."
The acidity makes the animals less able to withstand warmer waters, and they are smaller now, she added. "These observations suggest that warming and acidifying seas will be a complex environment for future marine organisms," Hofmann said.
-----
Tiny Amounts of Estrogen May be Serious Threat to Fish Population
Some ecosystems near large population centers can be quite fragile, and a study presented over the weekend demonstrated this by using an unlikely substance -- estrogen.
Scientists from Canada's Natural Sciences and Engineering Research Council (NSERC) found that extremely tiny amounts of synthetic estrogen -- the type found in birth control pills -- introduced from municipal wastewater plants into lakes and rivers downstream can cause a decline (and even the
elimination) of entire populations of some species of fish.
According to a NSERC news release, the study was presented at a session of the Association for the Advancement of Science's annual conference in Boston Feb. 16. Researchers said they added tiny amounts per trillion to a Canadian lake region in a re-creation of what may normally be found in a municipal wastewater plant.
Results of the seven-year study were dramatic. Estrogen exposure led to the near extinction of the lake's fathead minnow population, and the population of larger fish such as pearl dace and lake trout declined.
"Generally, the smaller the fish, the more vulnerable they are to estrogen," said lead researcher Dr. Karen Kidd, a biology professor at the University of New Brunswick (Saint John). "What we demonstrated is that estrogen can wipe out entire populations of small fish, a key food source for larger fish whose survival could in turn be threatened over the longer term," she added in her statement.
The researchers recommended that estrogen be removed from municipal water supplies during the treatment process, just as other contaminants are removed.
