WEDNESDAY, Feb. 24 (HealthDay News) --
Researchers are moving ahead -- although sometimes ploddingly --
toward the goal of using stem cell therapies to rescue people
with cardiovascular disease, the leading killer of men and women
in the United States.
Although much of the gains thus far have been in basic science,
stem cells do seem close to actually being able to help actual
humans.
"We have seen consistent but modest effects of stem cells in
improving heart function and reverse remodeling of heart," said
Dr. Gordon Tomaselli, a spokesman for the American Heart
Association and an associate professor of medicine at the Johns
Hopkins University School of Medicine in Baltimore.
"I think there's great hope," added Dr. Darwin J. Prockop,
director of the Texas A&M Health Science Center College of
Medicine Institute for Regenerative Medicine at Scott & White in
Temple.
Several studies presented last November at the annual scientific
sessions of the American Heart Association in Orlando serve as
examples.
In one study, out of Germany, 35 patients who received
bone-marrow stem cell transplantation during coronary artery
bypass surgery achieved "excellent long-term safety and
survival."
Ten patients who received similar transplantations after repair
of mitral valves also fared well, with improvements in the
heart's pumping capacity.
Slovenian investigators had similar success, with improvements
seen in patients with advanced heart failure who received
bone-marrow derived stem cells.
There were also advances in gene therapy reported, with Singaporean
researchers using nanotechnology to deliver genetically modified cells to
help heal heart attack damage in rabbits.
The stem cell promise hinges on the ability to produce unlimited supplies of
human cardiac cells, experts say.
Kevin Eggan, chief scientific officer for the New York Stem Cell Foundation
and associate professor of stem cell and regenerative biology at Harvard
University, noted two breakthrough treatments that would require steady
production of stem cells.
One is a future "patch" made out of these cells to fix a damaged heart after
a heart attack. Researchers also hope to fashion blood vessels out of stem
cells for use in bypass surgery and other procedures.
"People are making very substantial progress in being able to make those
various vascular cells you would need," Eggan said. "Transplanting those is
something that will come from all of this."
More immediately, perhaps, is the use of stem cells to screen heart drugs,
sort of like test-driving the drugs in preclinical trials, Eggan said.
"You can do this in a couple of different ways," Eggan said. Researchers
could determine in a laboratory dish if a drug actually works on heart
cells, he said. The other method would involve manufacturing heart cells for
a variety of people to find out which cells the drugs work on.
"One of the tricky things about drug trials is they often don't work on all
people equally well," Eggan explained. "You have to study a whole lot of
people to be able to see any sort of effects. This would screen out people
that the drug doesn't work on. It would enable personalized medicine."
One innovation that is close to market, Eggan said, is a method for
identifying and eliminating toxic drugs before they go into clinical trials.
A system is in the works that would involve testing drugs on heart muscle
cells in a lab dish.
"This could save enormous time and money in clinical trials," Eggan said.
Gene therapy has not advanced as far, he added, but predicts that it will
combine with stem cell therapies in the future.
"The one good thing that really has come out is that nobody has been harmed
by [the stem cell] therapies," Prockop pointed out.
Source : HealthDay
