Stem Cells Repair Heart Attack Damage
Advances prompt call to scientists to plead their own case
THURSDAY, July 8, 2004 (HealthDayNews) -- For the first time, scientists have succeeded in using a person's own bone marrow stem cells to help repair the heart after a heart attack.
And in a different study, researchers have transformed adult skin cells into precursor nerve cells, which may have implications for Parkinson's and other diseases.
These advances, both appearing in the July 10 issue of The Lancet, have prompted the journal, in an editorial, to exhort scientists to start arguing the case for the benefits of stem cell research.
Scientists have long been looking for ways to restore damaged heart muscle.
The heart study, done by German researchers, involved 60 patients who had undergone successful angioplasty and stenting to restore blood flow in the coronary artery. Half were given bone marrow stem-cell transfers, which were injected into the artery supplying the damaged area of the heart. The rest were given the best available conventional care.
Patients in the stem cell group had a 6.7 percent improvement in left ventricular function compared to only 0.7 percent for patients in the other group. The improvement was still evident six months after the treatment.
"What makes this notable is it's the first controlled study where they actually have a control group," said Dr. Robert Bonow, chief of cardiology and professor of medicine at Northwestern University in Chicago and past president of the American Heart Association. "In previous studies, you didn't know whether the stem cells were responsible or if it was going to happen anyway."
The study, however, is a small one that didn't look at people with very large heart attacks and doesn't indicate what role the stem cells are performing, Bonow added.
The motivation for the second study was the need to find new sources of neural stem cells other than human embryos, which present both ethical and practical problems.
"The fundamental problem is the embargo on any development of any new embryonic stem cells," said Dr. Philip E. Stieg, chairman of the department of neurological surgery at Weill Medical College of Cornell University. "One of the sources we are getting them from are adult human brains, but obviously a much more usable and easy source would be from skin or blood."
Neural stem cells have potential in developing treatments for various neurodegenerative diseases such as Alzheimer's and Parkinson's.
The authors of this study, based in England, used adult skin cells to generate nerve precursor cells. Not only would this be a new source of stem cells, but, Stieg explained, "you can imagine that if you're the person with the disease, you could isolate stem cells from an individual's skin, and then you wouldn't have the immunity issues."
Although it's not the first study of its kind, it is an important step forward, albeit an early one, because the cells did differentiate into neuronal-type cells, Stieg said.
But according to an accompanying editorial, the role of scientists like these now needs to move beyond the laboratory.
"The case for stem-cell research cannot be left to patient advocates alone," the editorial stated. "While the . . . profile of campaigners such as the actor Christopher Reeve are important in galvanizing public interest, scientists are even better placed to lead a public debate about the potential benefits -- and costs -- of working with stem cells. It is time for these scientists to step forward."
U.S. Sen. John Kerry, the all-but-certain Democratic nominee for president, has promised to make stem cells an election issue, which could push the debate into a much-needed public forum.
Carol A. Tauer, author of yet another article in this special issue, proposes separating the issues of reproductive cloning and cloning for research.
"There's a very high level of agreement that cloning for people definitely should not be attempted with humans at this time, [so] a prohibition of cloning for reproducing should be easy," said Tauer, a visiting professor at the University of Minnesota's Center for Bioethics in Minneapolis and a member of the ethics advisory board of Advanced Cell Technology, a company engaged in stem-cell research. "When you try to put too many things together, it confuses issues for legislators and the public."
Specifically, she proposed, the transfer of an embryo to a human for implantation should be prohibited either by some international treaty or federal legislation.
"I think to get a prohibition of reproductive cloning would help to set people's mind at rest that scientists are not trying to do this under the table," Tauer said.
Visit the National Institutes of Health for more on stem cells.