Wednesday, July 05, 2006

Health Headlines - July 5

Canada Confirms 6th Case of Mad Cow Disease

Canada has confirmed the country's sixth case of mad cow disease, the Associated Press reported Tuesday.

The government said it would find out where the cow was born and whether other animals had eaten the same feed. The animal was at least 15 years old, and was born before Canada enacted strict regulations on potentially contaminated feed in 1997. Mad cow disease is believed to spread through feed because cows can ingest the tissues of other cattle.

Humans can get a related disease known as Creutzfeldt-Jakob disease by eating contaminated meat. More than 150 humans have died this way, the AP said.

Two of the six mad cow cases in Canada occurred in animals born after 1997, but the government says the food supply is safe and the actual occurrence of the disease among cows is very low, given that there are 17 million cattle in that country.

In 2003, shipments of Canadian cattle to the United States were halted when the first case of mad cow disease was reported. Last year, trade in young animals resumed, although it is not clear when trade in older animals might resume. Last week, U.S. Agriculture Department spokesman Ed Loyd told the AP that U.S. officials have a "high degree of confidence in the safeguards and mitigating measures in place in the U.S. and Canada."

First Face Transplant Called a Success

French doctors say that the world's first face transplant has been a triumph, the BBC reported Monday.

The physicians report in the July 3 issue of The Lancet that the 38-year-old woman whose face was mauled by her pet Labrador recovered sensation in her face only four months after the procedure was completed.

The French surgical team made history when it transplanted tissues, muscles, arteries and veins from a brain-dead donor onto Isabelle Dinoire's lower face in November 2005. A week later, she was able to eat and drink normally, although she is receiving physical therapy to recover full movement around her lips. Dinoire did experience a slight rejection of the new tissue, but immunosuppressant drugs were able to quell the reaction, the report said.

"The four-month outcome demonstrates the feasibility of this procedure," said Dr. Bernard Devauchelle, who led the surgical team that performed the operation. "The functional result will be assessed in the future, but this graft can already be deemed successful with respect to appearance, sensitivity, and acceptance by the patient."

Young Drinkers More Likely to Have Alcohol Dependence Problems Later

Teenagers who start drinking before the age of 14 face a much higher risk of alcohol dependence during their lifetime, a new study suggests.

Researchers from Boston University, who report their findings in the July issue of the Archives of Pediatric and Adolescent Medicine, analyzed a national survey of more than 43,000 adults aged 18 and older.

Overall, 12.5 percent of all those surveyed and 19 percent of those had had ever drank alcohol experienced alcohol dependence at some point in their lifetime. However, 47 percent of those who began drinking before the age of 14 experienced alcohol dependence later, compared to 9 percent of those who did not drink until 21. The younger drinkers also were three times more likely to experience two or more episodes of alcohol dependence in their lifetime.

"Usually, each additional year earlier than age 21 years that a respondent begins to drink, the greater the odds that he or she would develop the alcohol dependence outcomes examined," the researchers wrote.

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 the July 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.

Acetaminophen Use Could Trigger Liver Damage

In a new study, people who repeatedly took the maximum recommended daily dose of acetaminophen developed abnormalities in blood tests that can be a signal for liver damage.

The study researchers said they first noted the potential for liver toxicity in patients treated for pain with a combination of the opioid hydrocodone plus acetaminophen. But, before this study, the scientists had assumed the threat came from the hydrocodone.

So, the new findings came as a somewhat of a shock, the researchers said.

"This clearly showed, much to our jaw-dropping surprise, that it had nothing to do with the opiate," said Dr. Paul Watkins, lead author of the study and professor of medicine at the University of North Carolina, Chapel Hill. "It was a previously unrecognized but pretty remarkable effect of acetaminophen alone when taken as directed for four days."

Still, acetaminophen, which is most commonly marketed as Tylenol, has been on the market for 20 years and has a clear safety record, Watkins said, and consumers should not stop taking the drug if they really need it.

"No one should ever take a drug they don't need," he said. "But this study is not a reason to stop taking acetaminophen if you need it."

"There is concern, but this is not black or white," added Dr. Eugene Schiff, M.D., chief of the division of hepatology and professor of medicine at the University of Miami Miller School of Medicine. He pointed out that acetaminophen has been known to elevate liver enzymes in people who are regular drinkers or who have been fasting.

However, Schiff said, "This paper is important, because they're showing that what we thought was the upper limit of safety in people who are not regular drinkers or fasting -- that it's too high. To me, the critical factor is, 'What is the upper limit that's safe?' "

Millions of people take acetaminophen for pain relief. Some of these people can't take aspirin because of its gastrointestinal effects, or can't take nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen (Aleve). Use of Celebrex, one of a newer class of NSAIDs called cox-2 inhibitors, is also controversial because of cardiovascular problems linked to two recalled cox-2s, Vioxx and Bextra.

The current findings came about by accident. In the process of conducting a trial on a combination acetaminophen/narcotic drug, Purdue Pharma discovered that a number of healthy volunteers had a high incidence of abnormalities in blood aminotransferase (ALT and AST) tests used to measure levels of specific liver enzymes. Those results "would normally be considered very alarming," Watkins said.

The initial concern was that it was the narcotic, hydrocodone, that was responsible for the increase.

That trial was halted, and the company called in Watkins and another expert to design the current study, published in the July 5 issue of the Journal of the American Medical Association.

Watkins and two other authors reported having served as paid consultants to Purdue during the planning and execution of the study but not during preparation of the article.

For this study, 145 healthy adults each received either a placebo, one of three acetaminophen/opioid combinations, or acetaminophen alone for 14 days. Each active treatment included 4 grams of acetaminophen daily, the maximum recommended daily dosage.

None of the patients in the placebo group had a maximum ALT measurement of more than 3 times the upper limit of normal.

However, in the four treatment groups, 31 percent to 44 percent of patients had a maximum ALT of more than three times the upper limits of normal. Those in the acetaminophen-alone group had a similar elevation, suggesting that the opioid had nothing to do with the effect.

"It was so unbelievable that I am conducting an ongoing study with 50 people," Watkins added. "That's not in the JAMA paper, but we're finding that it verifies the findings."

The authors suspect, however, that ALT elevations should go down, even after continued use of acetaminophen. "I'm quite convinced that if we continue to treat people, they would come back to normal, so that about after a month, I believe liver chemistries would be normal, even continuing," Watkins said.

One question raised by the paper is whether aminotransferase elevations are even accurate in predicting the potential for liver damage.

"In the past, when we've seen liver enzyme abnormalities to this extent, it has indicated to us physicians that there is significant liver injury or damage occurring," Watkins said. "Since we have decades of experience and know the safety of acetaminophen, are the tests as good as we thought they were? Maybe they're not good predictors as to which drugs are going to have liver problems," he added.

It's also possible that a number of past tests have been misread, incorrectly attributing elevations to a drug other than acetaminophen.

"Because recommended doses of acetaminophen have not been previously recognized to cause liver enzyme elevations, physicians may have embarked on costly liver evaluations unnecessarily," Watkins said. "Also, treatment with other drugs suspected to cause liver problems, such as lipid-lowering medicines, may have been stopped unnecessarily."

The message to consumers is to pay attention to dosing and duration of use when taking acetaminophen (and other drugs). In particular, pay attention to "hidden" acetaminophen in other drug products.

"There are a lot of combination drugs that include acetaminophen that people aren't aware," Schiff said. "That's been a problem."

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