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Jul 30, 2010 4:10 PM by Melissa Canone

Innovative Therapies Doctors are Studying Using "Adult" Stem Cells

NEW YORK (AP) - A few months ago, Dr. Thomas Einhorn was
treating a patient with a broken ankle that wouldn't heal, even
with multiple surgeries. So he sought help from the man's own body.
Einhorn drew bone marrow from the man's pelvic bone with a
needle, condensed it to about four teaspoons of rich red liquid,
and injected that into his ankle.
Four months later the ankle was healed. Einhorn, chair of
orthopedic surgery at Boston University Medical Center, credits
"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 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's adult stem cells
that are in human testing today. An extensive review of stem cell
projects and interviews with two dozen experts reveal a wide range
of potential treatments.
Adult stem cells are being studied in people who suffer from
multiple sclerosis, heart attacks and diabetes. Some early results
suggest stem cells can help some patients avoid leg amputation.
Recently, researchers reported that they restored vision to
patients whose eyes were damaged by chemicals.
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," says Dr. David Scadden of
Harvard, who notes stem cells are also used to grow skin grafts.
"If we can recreate 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 former
President George W. Bush to allow only restricted federal funding
for studying them.
Proponents over the past decade have included former first lady
Nancy Reagan and actors Michael J. Fox and the late Christopher
Reeve. 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 like Parkinson's or
diabetes. Just on Friday, a biotech company said it was 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.
Observers say they're not surprised at the pace of progress.
As medical research goes, the roughly 10 years since the
embryonic cells were discovered "is actually a very short amount
of time," said Amy Rick, immediate past president of the Coalition
for the Advancement of Medical Research. The group has pushed for
embryonic stem cell research for about that long.
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 to 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. Tens of
thousands of people are saved each year by such procedures, experts
say.
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'd transplanted
two windpipes injected with the recipients' own stem cells.
But these developments only hint at what's being explored in
experiments across the United States.
Much of the work is early, and even as experts speak of its
promise, they ask for patience and warn against clinics that
aggressively market stem-cell cures without scientific backing.
Some of the new approaches, like 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're 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," says Rocky
Tuan of the University of Pittsburgh.
One major focus of adult stem cell work for about a decade has
been the ailing heart. While researchers remain committed, much of
the early enthusiasm from patients, doctors and investors has
slacked off because results so far haven't matched expectations,
says Dr. Warren Sherman of Columbia University.
"Everyone, including myself, is impatient and would like to see
positive results appear quickly," said Sherman, who hosts an
annual international meeting of researchers. But he called for
patience.
In treating heart attack, for example, studies show stem cell
injections help the heart pump blood a bit better, Sherman said.
But the research has not yet established whether injections cut the
risk of death, more heart attacks or future hospitalizations, he
said.
Sherman said he hopes a large study of those patient outcomes
can be done in the next couple of years, and is "very optimistic
that patients will benefit."
Similarly, in heart failure, research indicates stem cells can
ease symptoms but larger studies are still needed to show how much
good the treatments provide, he said. He noted that current studies
are testing stem cells taken not only from bone marrow and leg
muscle, but also from fat.
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 here
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."
The injected cells may serve as building blocks while also
stimulating local tissue to grow the vessels, said Dr. Douglas
Losordo of Northwestern University. His own preliminary work
suggests such a treatment can reduce amputation rates.
Dr. Gabriel Lasala of TCA Cellular Therapy also 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.
"I'm even thinking about taking up a little tennis again."
With all the heart-related stem cell studies, the president of
American Heart Association says, "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, says Dr.
Clyde Yancy.
Among the other diseases being studied for stem cell treatments:
-Multiple sclerosis. In MS, the body's immune system repeatedly
assaults brain and spinal cord tissues, which can cause numbness in
the limbs, paralysis or vision loss.
Last year, Dr. Richard Burt of Northwestern reported a small
trial in patients with early MS that was aimed at rebooting the
immune system to stop the attacks. He removed stem cells from the
patient's blood, destroyed their immune systems, and then
re-injected them with their own cells to build a new immune system.
To his surprise, most patients actually improved. He's now
conducting another trial to provide firmer evidence of improvement.
Dr. Jeffrey Cohen of the Cleveland Clinic is trying a different
and less-researched approach. In a preliminary trial he is just
starting, he'll use a different kind of stem cell from patients'
marrow that he hopes can slow nervous system damage but also
promote repair.
Lessons learned from this approach might eventually reveal some
clues for treating other conditions like Parkinson's or spinal cord
injury, he said.
-Type 1 diabetes. It's also caused by a misguided attack by the
immune system, this time on insulin-producing cells. Burt and
colleagues reported last year that the "rebooting" strategy
allowed some patients to go without insulin for four years.
However, some experts call his approach too risky for that disease.
Burt is now doing another study in newly diagnosed adults.
Another study, at about a dozen medical centers around the
country, is testing whether an off-the-shelf preparation of marrow
stem cells can calm the immune system of diabetics. It's still
early work, says C. Randal Mills, chief executive officer of Osiris
Therapeutics.
-Cancers such as melanoma and kidney cancer. The idea is to
transplant cells to produce a new immune system that will attack
the diseases. Earlier work around a decade ago failed to give
lasting benefit, but new approaches aim for better results, said
Dr. Michael Bishop of the National Cancer Institute.
Even as scientists hope adult stem cells will produce new
treatments, they are concerned about clinics that make claims about
unproven stem cell therapy.
"Clinics have sprung up all over the world ... that are
essentially selling snake oil, that are preying on the hopes of
desperate patients," said Sean Morrison, a stem cell expert at the
University of Michigan.
Morrison suggests patients consult their own doctors about going
to a clinic.

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