segunda-feira, 1 de março de 2010

Heart Stem Cells Move Closer to Human Treatments

February 2010
by Amanda Gardner
Business Week

'Patch' for damaged heart is just one of several promising developments

There is a wide-spread notion that stem cell therapy is something of the future. While to date non-hematopoietic uses of stem cells are not commercially available in the United States, there are numerous clinical trials ongoing that if successful will allow for FDA registration.

In the area of heart failure substantial progress has been made. We previously discussed cases from outside of the US, such as that of David Alanis , which was published in the peer-reviewed medical literature (Ichim et al. Placental mesenchymal and cord blood stem cell therapy for dilated cardiomyopathy. Reprod Biomed Online. 2008 Jun;16(6):898-905).

Recently the consensus in the cardiology community is that stem cell therapy is becoming closer to mainstream implementation.

"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. He continued "The one good thing that really has come out is that nobody has been harmed by [the stem cell] therapies."

In November 2009 at the annual meeting of the American Heart Association in Orlando, several reports of progress in a controlled setting were discussed. A group from Germany presented data on 35 patients who received bone-marrow stem cell transplantation concurrently with coronary artery bypass surgery. According to the authors, the patients achieved "excellent long-term safety and survival." The same group also showed that 10 patients who received stem cells from the bone marrow after mitral valve repair surgery also had improved heart function with documented increases in the ability of the heart to pump blood. Doctors from Slovenian also presented data demonstrating bone marrow stem cells induced improved function in patients with heart failure.

There is some controversy as to the mechanisms of action by which stem cells help in heart failure. Original studies supported the notion that bone marrow blood making stem cells, hematopoietic stem cells, can become heart cells. Subsequently it was found that the bone marrow contains other types of stem cells that could become heart cells. More recent studies support that idea that bone marrow stem cells produce chemical signals that instruct the stem cells already in the heart to accelerate the healing process.

Kevin Eggan, chief scientific officer for the New York Stem Cell Foundation and associate professor of stem cell and regenerative biology at Harvard University, commented on two major advances. The first being an artificial "patch" comprised of stem cells that can be placed on the heart after an infarct. He stated "People are making very substantial progress in being able to make those various vascular cells you would need...Transplanting those is something that will come from all of this."

Another breakthrough in his mind is the use of stem cells to screen for drugs. Since stem cells can be made into human heart cells in the test tube, this would allow for scientists and companies to rely less on animal testing and go directly into human systems. According to Dr. Eggan, "You can do this in a couple of different ways. 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."

To find more information about ongoing clinical trials, patients may look at, or for outside of US treatments


Sem comentários: