Health Highlights: April 28, 2007
Mouse Study May Explain Why Alcohol Increases Breast Cancer Risk FDA Approves New Treatment for Bleeding Disorder AMA: Tobacco Makers Spend Too Much on Advertising Blood Pressure-Lowering Drug Shows Benefits in Trials: Maker Scientists Identify Immune System Factor New Test IDs Hepatitis C Patients at Risk of Cirrhosis
Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
Mouse Study May Explain Why Alcohol Increases Breast Cancer Risk
U.S. researchers say studies with mice may help to explain the link between alcohol consumption and breast cancer risk.
For the first time, researchers at the University of Mississippi Medical Center used a laboratory mouse model to mimic the development of human alcohol-induced breast cancer.
Drinking even moderate amounts of alcohol is an established risk factor for breast cancer in women. A recent study showed that 60 percent of breast cancers worldwide were attributable to alcohol consumption. But, the biology behind alcohol-induced breast cancer was poorly understood, the study authors said.
Possible causes have included alcohol's impact on estrogen metabolism and response, cell mutation and oxidative damage.
Until the new study, there hadn't been an animal model that faithfully mimicked the characteristics of alcohol-induced breast cancer. So the study authors bioengineered female mice that, at six weeks of age, were fed the equivalent of two drinks per day in humans. Control mice received regular drinking water only.
The researchers found that:
- moderate alcohol consumption significantly increased the tumor size of breast cancer in mice -- a 1.96-fold increase in tumor weight compared to the control mice;
- alcohol intake caused a 1.28-fold increase in tumor microvessel density compared to the control group;
- alcohol intake did not cause significant changes in the body weight of the mice.
The researchers are to present their findings at the American Physiological Society annual meeting, which is being held as part of the Experimental Biology (EB 07) meeting. April 28 through May 2, in Washington, D.C.
FDA Approves New Treatment for Bleeding Disorder
The U.S. Food and Drug Administration approved on Friday a new therapy to prevent excessive bleeding during and after surgery in certain patients with von Willebrand disease (vWD). The disease is the most common inherited bleeding disorder, affecting about 1 percent of the U.S. population.
Humate-P is the second biological product to be approved for surgery and invasive procedures in patients with vWD who don't respond to the medication desmopressin. The first biological product, Alphanate, was approved by the FDA earlier this year. But, Humate-P is the first product specifically for patients with severe vWD who are undergoing major surgery, the agency said.
"This is an important advance for patients with vWD, including those who are severely affected by the disorder," said Dr. Jesse Goodman, director of FDA's Center for Biologics Evaluation and Research. "Humate-P provides a preventive therapy that can make needed surgery not only possible, but also safer."
Men and women are equally affected by vWD, which is caused by a deficiency or defect in certain plasma proteins critical to blood clotting.
Humate-P is manufactured by CSL Behring GmbH, in Marburg, Germany.
AMA: Tobacco Makers Spend Too Much on Advertising
Despite a two-year decline in the amount of money tobacco makers spend on marketing and advertising, the American Medical Association says too much is still spent on promoting cigarettes and other forms of smoking.
Spending on marketing and advertising among the five largest U.S. tobacco firms fell to $13.1 billion in 2005 from $14.15 billion in 2004 and $15.15 billion in 2003, the U.S. Federal Trade Commission said in a report issued Thursday.
But anti-smoking advocates said promotional spending was still double the amount spent in 1998, the year the tobacco firms entered into a landmark multi-state settlement, the Associated Press reported.
The AMA added its voice to those who called the amount spent by cigarette makers to promote smoking excessive.
"In 2004 and 2005 alone, the tobacco industry spent an exorbitant $27.7 billion to market their deadly products to the American people," the association said in a statement. "That same money could pay for virtually every smoker in America to receive a full course of nicotine treatment to help them quit."
Noting that the effects of smoking kill some 1,200 Americans daily, the group called for giving the U.S. Food and Drug Administration the authority to "regulate the manufacture, sale, distribution, and marketing of tobacco products."
The U.S. Congress is considering legislation giving the FDA such authority, the AP reported. The bill may have a better chance of passing than similar legislation proposed in 2004, the wire service said, since Democrats now control both chambers of Congress.
Blood Pressure-Lowering Drug Shows Benefits in Trials: Maker
The Novartis blood pressure-lowering drug Diovan (valsartan) showed a 39 percent decreased risk of cardiovascular events and a 40 percent drop in stroke during a 3,000-person Japanese trial, its manufacturer says.
Diovan is among a class of drugs called angiotensin receptor blockers (ARB). In the Jikei Heart Study, scientists compared Diovan combined with conventional non-ARB therapies with use of the non-ARB therapies alone.
In a statement, Novartis said the study was "terminated earlier than anticipated ... due to superior outcomes for the valsartan group over the control group."
Those outcomes also included a 65 percent drop in the incidence of angina pectoris, a 46 percent drop in heart failure, and a drop of 81 percent in aortic dissection -- a tear in the body's largest artery.
Results of the study were published in the April 28 issue of The Lancet.
Scientists Identify Immune System Factor
American and British scientists working independently have identified a genetic element that appears key to regulating the human immune system, The New York Times reports.
The element is a chemical cousin of DNA referred to as a micro-RNA. Dubbed miR-155, it's among 500 such micro-snippets of genetic material that are found to be especially abundant in the body's antibody-making immune cells, the newspaper said.
When the genetic component was removed from mice, the genetically engineered rodents no longer responded well to vaccination and failed to develop immunity, the Times reported.
"The work on miR-155 opened a window into the understanding of the immune system, but it is too early for immunologists to figure out any practical consequences," the newspaper account said.
New Test IDs Hepatitis C Patients at Risk of Cirrhosis
A new genetic test can help identify people diagnosed with hepatitis C who are at risk of developing cirrhosis, Stanford University researchers say.
The test evaluates the genetic makeup of each patient to determine who is most likely to contract cirrhosis, a liver disease characterized by severe scarring.
The test analyzes variations on seven genes to comprise a "signature" of certain people who are likely to develop cirrhosis, the researchers said in a statement announcing successful results of their evaluation of the new test. The diagnostic -- which costs about $500 -- was developed Celera, a company based in Rockville, Md.
People with hepatitis C found to be at high risk of cirrhosis could be prescribed a course of "expensive, debilitating drug therapy, while low-risk patients might be better off delaying treatment," the researchers said.
Nearly 4 million Americans are infected with the hepatitis C virus, of which nearly 80 percent have a chronic infection that could progress to cirrhosis, the researchers said. Cirrhosis, in turn, can progress to liver failure or liver cancer, they added.