Einhorn drew bone marrow from the man’s pelvic bone with a needle and injected that into his ankle.
Four months later, the ankle was healed. Einhorn, chairman of orthopedic surgery at Boston University Medical Center, credits so-called adult stem cells in the marrow injection. He tried it because of published research from France.
Einhorn’s experience isn’t a rigorous study. But it’s an example of many innovative therapies that doctors are studying with adult stem cells. Those are stem cells typically taken from bone marrow and blood — not embryos.
For all the emotional debate that began about a decade ago on allowing the use of embryonic stem cells, it is adult stem cells that are in human testing today. An extensive review of stem cell projects and interviews with two dozen experts reveal a range of potential treatments.
Adult stem cells are being studied in people who suffer from multiple sclerosis, heart attacks and diabetes.
Apart from these efforts, transplants of adult stem cells have become a standard lifesaving therapy for perhaps hundreds of thousands of people with leukemia, lymphoma and other blood diseases.
“That’s really one of the great success stories of stem cell biology that gives us all hope,” said David Scadden of Harvard, who notes stem cells are also used to grow skin grafts.
“If we can re-create that success in other tissues, what can we possibly imagine for other people?”
That sort of promise has long been held out for embryonic stem cells, which were first isolated and grown in a lab dish in 1998. Controversy over their use surrounded the 2001 decision by President George W. Bush to allow only restricted federal funding for studying them.
Opponents object that human embryos have to be destroyed to harvest the cells.
Embryonic cells may indeed be used someday to grow replacement tissue or therapeutic material for diseases such as Parkinson’s or diabetes. On Friday, a biotech company said it is going ahead with an initial safety study in spinal cord injury patients. Another is planning an initial study in eye disease patients later this year.
But in the near term, embryonic stem cells are more likely to pay off as lab tools, for learning about the roots of disease and screening potential drugs.
Hank Greely, a Stanford University law professor who works in bioethics and has followed stem cells since the 1990s, said: “Give it another five years, and I’ll be surprised if we don’t have some substantial progress” beyond initial safety studies.
The Pro-Life Secretariat of the U.S. Conference of Catholic Bishops continues to oppose embryonic work. Deirdre McQuade, an official there, said that compared with adult stem cell research, work on embryonic cells is proving “fruitless.”
Adult cells have been transplanted routinely for decades, first in bone marrow transplants and then in procedures that transfer just the cells. Doctors recover the cells from the marrow or bloodstream of a patient or a donor and infuse them as part of the treatment for leukemia, lymphoma and other blood diseases.
But it is harnessing these cells for other diseases that has encouraged many scientists lately.
In June, for example, researchers reported they had restored vision to people whose eyes were damaged from caustic chemicals. Stem cells from each patient’s healthy eye were grown and multiplied in the lab and transplanted into the damaged eye, where they grew into healthy corneal tissue.
A couple of months earlier, the Vatican announced it was funding adult stem cell research on the intestine at the University of Maryland. And on Friday, Italian doctors said they had transplanted two windpipes injected with the recipients’ own stem cells.
But these developments only hint at what’s being explored in experiments across the U.S.
Some of the new approaches, such as the long-proven treatments, are based on the idea that stem cells can turn into other cells. Einhorn said the ankle-repair technique, for example, apparently works because of cells that turn into bone and blood vessels. But for other uses, scientists say they are harnessing the apparent abilities of adult stem cells to stimulate tissue repair or to suppress the immune system.
“That gives adult stem cells really a very interesting and potent quality that embryonic stem cells don’t have,” said Rocky Tuan of the University of Pittsburgh.
One major focus of adult stem cell work has been the ailing heart. While researchers remain committed, much of the early enthusiasm from patients, doctors and investors has slacked off because results haven’t matched expectations, said Warren Sherman of Columbia University.
In treating heart attacks, for example, studies show stem cell injections help the heart pump blood a bit better, Sherman said. But the research has not established whether injections cut the risk of death, more heart attacks or future hospitalizations, he said.
Another heart-related condition under study is critical limb ischemia, where blood flow to the leg is so restricted by artery blockage it causes pain and may require amputation. The goal is to encourage growth of new blood vessels by injecting stem cells into the leg.
Sherman said limb ischemia research is moving fast and the results “are very, very encouraging.”
Physician Gabriel Lasala of TCA Cellular Therapy has reported positive preliminary results. One success is Rodney Schoenhardt of Metairie, La.
Schoenhardt had already had surgery on both legs for the disease, and his surgeon was talking about amputating his left leg. Schoenhardt suffered so much pain in his left leg while standing that he used a wheelchair instead.
For Lasala’s research, Schoenhardt got 40 shots in each leg about 18 months ago, with stem cells going into his left calf and a placebo dose into the other. Soon, he said, the pain in his left leg was gone.
Schoenhardt, 58, now mows his lawn, and he remodeled his living room to fix damage from Hurricane Katrina.
“My wheelchair is in my garage, collecting dust,” he said.
With all the heart-related stem cell studies, physician Clyde Yancy, a former president of the American Heart Association, said: “We should be enthusiastic, but cautiously so.”
Beyond the promising indications of early studies, researchers need definitive evidence that the treatments not only make patients better but also don’t cause unintended harm, Yancy said.
From : www.kansascity.com