Here's the weird organ transplant story of today. A heart, maybe a human one, was found on the floor of a car wash in Michigan. Investigators are trying to determine if it's a human heart or from another species. No word on if Dick Cheney had recently washed his car there.
Courtesy wikipediaHere’s something to strengthen your heart in advance of Valentine’s Day. Nationally, our rates for heart attack and stroke deaths have dropped faster than the pace national health organizations hope we’ll be at in 2010.
Over the period from 1999 to 2005, heart disease deaths dropped 25.8 percent while stroke deaths dropped 24.4 percent. That means that 160,000 people are still alive today who statistically would have likely died from heart and circulation trouble in the past year. If those rates continue, we’ll have an extra 240,000 people living a year from now who in past years would have died from heart ailments.
However, while our hearts are getting healthier epidemics continue on the diabetes and obesity fronts. And health problems associated with those factors could offset the decreased deaths from heart troubles.
The National Center for Health Statistics released the analysis of these health findings, but didn’t issue any causes for the changing mortality rates. So I put it to you, why are people having better heart health? Better diets? Decreased smoking? More exercise? Share your thoughts here with Science Buzz readers.
Tissue engineering has allowed a dead rat heart to be stripped of its cellular material, then after injecting the remaining scaffold material with with new cardiac cells, the cells organized themselves until the heart became alive.
A "crazy idea" at the University of Minnesota that could not get federal funding yielded "unbelievable" results after getting funding from the University of Minnesota and from the Medtronic Research Foundation.
The accomplishment gave a significant boost to medicine’s dream of growing human organs to replace damaged ones. Organ transplants usually require replacement organs that fulfill extreme compatibility issues. By using the patients own cells in the rebuilt organs scientists hope to eliminate the need for patients to take anti-rejection drugs for the rest of their lives.
The next step will be to use these techniques on pig hearts. Pig hearts are similar enough to a humans that parts from them have already been used in humans.
"Although this is only a first step requiring considerable follow-up development, the study nevertheless represents an exciting breakthrough that will eventually make the prospect of repairing damaged hearts a reality and will also be an approach that can be extended to other organs." Dr Jon Frampton Wellcome Trust Senior Fellow at the University of Birmingham
New York Times
Nature Medicine journal's Perfusion-decellularized matrix: using nature's platform to engineer a bioartificial heart (abstract)
A European study has found that women taking oral contraceptives (birth control pills) are at a higher risk for blood clots and heart disease.
A recent study in Poland showed that a flu shot can significantly reduce the risk of death for people with coronary artery disease. Dr. Arnold Monto, professor of epidemiology at the University of Michigan, said,
"We know that people die of flu who have underlying cardiopulmonary disease. It's only logical that if you are able to prevent flu with vaccine, you can prevent these deaths."
On May 11, 1987, doctors in Baltimore transplanted the heart and lungs of an auto accident victim to a patient who gave up his own heart to a second recipient. Clinton House, the nation's first living heart donor, died 14 months later. Want to know more about organ or body donation? Check the Buzz next week for a new feature!
The Women's Health Initiative is a clinical trial sponsored by the National Heart, Lung, and Blood Institute, an institute of the National Institutes of Health. It included the largest ever study of a low-fat diet in postmenopausal women to see if such a diet reduced their rate of contracting certain diseases. 48,835 women aged 50-79 participated for an average of 8 years. The results of the low-fat diet trial showed no significant reduction in the rate of breast cancer, heart disease, or stroke and no effect on the risk of colorectal cancer. However, the women in the study had trouble sticking to the recommended amount of daily fat and they did not necessarily cut out the types of fat considered most harmful (saturated fats and trans fats).
What About Nutritional Supplements?
The study also followed 36,282 women of the same age range to find out if calcium and vitamin D supplements reduced the rate of broken bones from osteoporosis. Again the results appeared to show no appreciable advantage to taking the supplements, although there was an average of 1% gain in bone density.
Drop the Supplements and Forget the Low-Fat Diet?
Researchers found that the trend in positive results was going upwards for the group on the low fat diet enough to encourage the researchers that continued monitoring of the women over the next few years will show a positive result. And people connected with the calcium/vitamin D supplement study say that despite the slightly elevated risk of kidney stones that was seen in some women, the overall gain in bone density was great enough to make a difference for some women and to have a positive impact on money spent on health care for osteoporosis-related injuries.
The upshot is that there are still opportunities to learn more information about how diet and supplements affect the health of these postmenopausal women, including why some subgroups of women were affected in ways that others weren't. Doctors and researchers aren't changing their overall advice yet, although people should always discuss their diets with their doctors as cases can differ from person to person.
Yesterday, an advisory panel for the Food and Drug Administration (FDA) recommended approval of a drug, BiDil, for heart failure in African-Americans. (The approval was unanimous, although two panel members voted against the racial indication labeling for the drug.) If the FDA follows the panel's advice, BiDil will become the first drug approved for use by patients of a particular race. The drug is a combination of two generic drugs (isosorbide dinitrate-also known as nitroglycerine-and hyrdralazine) that works by increasing the body's concentration of nitric oxide, which widens the arteries and helps the heart function more efficiently. The drug was tested in 1,050 African-Americans last fall. In that study, patients taking BiDil had much better survival rates and were much less likely to be re-hospitalized for congestive heart failure. Dramatic outcomes like this are a good thing, right? Yes. But the idea that a drug be approved for patients of a specific race makes many doctors uncomfortable, and it may also be bad medicine. Jonathan Kahn, a law professor and medical ethicist at Hamline University, said:
"It sends the message that because [the study] was done only in African-Americans that somehow African-Americans are different genetically than everybody else. And that is a very dangerous message to be sending. It's one that doesn't need to be sent in order to bring this drug to market."
Some cardiologists think the reason the drug works so well for many African-Americans may not be a matter of "race" (for which there is no scientific/genetic basis), but is probably related instead to the root cause of their heart failure: African-Americans are more likely to suffer heart failure due to high blood pressure, while whites are more likely to suffer heart failure due to clots caused by heart attacks or atherosclerosis. But some African-American patients do suffer heart failure caused by clots or hardening of the arteries, and some white patients do have heart failure related to high blood pressure. So critics think that the drug should be labeled for use by patients with heart failure caused by hypertension, instead of use by African-American patients. Dr. Gail Christopher, co-chair of the National commission on Health, Genomics and Human Variation, says:
"It would be 'bad science' to label or market this drug as a 'Black' drug. More importantly, race-based claims are not credible in the face of modern genetic medicine."
The New York Times says:
"The drug's maker, NitroMed Inc., says its decision to test and market BiDil as a drug for African-Americans is based on solid science. But BiDil's application [for FDA approval] has engendered controversy, with many scientists convinced that race is too broad and ill-defined a category to be relevant in determining a drug's approval, especially since geneticists have failed to identify a biological divide separating one race from another. Scientists know that different people have different responses to medications, and in some cases these have been linked to race. The FDA, for example, has said that people of Asian ancestry are more likely than others to get serious side effects from the cholesterol-lowering drug Crestor. But research shows that the underlying genetic variations across races are small. [Studies have shown that genetic variation within any racial group exceeds that between two groups.] Scientists believe that genetic markers will someday be found that explain the different reactions to drugs, but for now, race or ethnicity is an imprecise shortcut. By approving BiDil, the FDA would go well beyond where it has in the past in using race as a category to evaluate which patients respond to drugs."
Other doctors feel that failing to take race into account when treating patients is unacceptable. Dr. Jim Kennedy, a spokesman for the Royal College of GPs, told the Times:
"To close one's eyes to colour is tantamount to a neglect of clinical duties. As a practicing professional, I took an oath not to pay any attention to a patient's race, creed, colour or background, and I take this very seriously. But if there is real evidence that because of your genetic inheritance you should be offered a certain drug, I would be negligent in not offering it to you. There may be people of African descent who will benefit from ACE inhibitors, but trying to guess what genes someone has inherited in impossible. So doctors make a reasonable stab at a first-choice drug and if it doesn't work we'll use our second choice. I think it's far worse if, for reasons of political correctness, we chose to ignore real, hard scientific facts."
What do you think about the prospect of race-based medicine? Should drug companies be marketing to specific ethnic groups? How is this harmful or helpful?
A new study published in The New England Journal of Medicine shows that low doses of aspirin do not prevent first heart attacks in women under 65, as they do in men.
Earlier research, which focused mostly or entirely on men, indicated that aspirin prevents heart attacks. But the 10-year Women's Health Study, which followed 40,000 women, showed that aspirin does not prevent heart attacks in women. However, it does prevent strokes caused by blood clots, a benefit that has not been conclusively proven in men.
Women in the control group had the same number of heart attacks as the women in the aspirin group. But the number of strokes in the aspirin group was 17% lower. And the aspirin takers had a whopping 24% lower risk of ischemic stroke—the most common kind, caused by a blood clot in an artery leading to the brain. However, the risk of hemorrhagic stroke—caused by bleeding—was slightly higher in the aspirin group. (This was expected, because aspirin reduces blood's ability to clot.)
Both ischemic strokes and heart attacks are caused by blood clots in arteries, so it isn't clear why aspirin only protects women against strokes. The explanation may have something to do with the size of the blood vessels that lead to the brain, which are smaller than those leading to the heart, but no one knows yet for sure.
Because aspirin therapy increases the risk of bleeding, doctors don't currently advise men or women with no risk of heart disease to take aspirin as a preventive measure. Women with risk factors for heart disease (they're over 65, they smoke, have high blood pressure, are diabetic, or have a family history of cardiovascular problems) are often told to take a baby aspirin every day. That probably won't change.
But now doctors can fine-tune the way they manage patients with cardiovascular risk, knowing that women under 65 are more vulnerable to certain kinds of stroke.
You can read the New York Times article about the study here
You can read an abstract of the article in The New England Journal of Medicine here
What do you think about research that shows that some drugs affect women differently than men? Should drug studies have to include equal numbers of men and women? Or should they look at men and women separately? How about different ethnic groups? Or children?