JERUSALEM (AP) _ After 61 years of pumping blood, Marie Carty's heart was failing her.
Months earlier she had given up her two-mile walk on the boardwalk of her New Jersey hometown along the Atlantic Ocean. She could barely make it from the parking lot to the view of the water.
Although Carty knew she needed a new heart, she was afraid hers wouldn't last during the long wait for a transplant.
Desperate for an alternative, Carty found the Israeli-Thai company Theravitae, which has begun performing an experimental procedure that multiplies stem cells taken from a patient's own blood and injects them into the ailing heart in hopes of strengthening it.
The procedure performed by Theravitae and a handful of other companies could offer new hope to hundreds of thousands of heart patients around the world.
The U.S. Food and Drug Administration has not yet approved the procedure for use in the United States, and though doctors hope it can be a substitute for heart transplants, the permanence of the repairs has yet to be ascertained.
``It's too early to know the long-term effects of these types of procedures,'' said Dr. Vincent Pompili, director of interventional cardiology at Case Western Reserve University in Ohio.
Several teams of doctors around the world _ including at least three in the United States _ say they are seeing promising results in similar trials using stem cells extracted from bone marrow.
Proponents of Theravitae's newer procedure say it is simpler and less painful to get stem cells from blood than extracting the cells from bone marrow.
The procedure involves no risk of rejection since the cells are the patient's own. It also does not use embryonic stem cells, an idea that has raised moral objections since they require the destruction of human embryos.
Many scientists believe stem cells could herald a new era of regenerative medicine, leading to cures for conditions from diabetes to Parkinson's disease.
After a two-week trip last fall to Thailand for the operation, Carty is once again walking two miles on the boardwalk in Little Silver, N.J. _ and her strengthened heart led doctors to remove her from the transplant list.
``The change is like night and day,'' said Carty, who works in property management. ``I feel myself again, more energy, more stamina.''
Carty is one of 70 people who have undergone Theravitae's procedure, said Valentin Fulga, chief executive of the company. All have shown improvement, he said.
The list also includes Hawaiian crooner Don Ho, who underwent the operation in early December in Thailand.
``I'm feeling much better and I'm so happy I came up here to do it,'' the 75-year-old entertainer said in a statement after the procedure.
Fulga said patients who get the procedure are generally heart transplant candidates or people who have undergone bypass surgery without positive results.
``We believe that these cells have the capacity of turning into blood vessels,'' Fulga said. ``The treatment seems to be not only very safe, with no side effects, but also effective because they improve.''
Fulga agrees, however, that with the procedure in trials for less than two years, there is still a lot to learn. For instance, he said, it's possible that over time the cells that repair the heart could lose their effectiveness.
Fulga said it also is not known exactly how the cells inserted into the heart improve the patient's condition. But it is believed they help reconstruct blood capillaries and vessels and the heart muscle itself, capitalizing on the body's natural healing processes, he said.
The treatment involves withdrawing blood from a patient and placing it in a centrifuge to separate out _ by weight and size _ a group of cells needed for the procedure. This batch of cells, called VesCell by the company, is composed of stem cells and other cells beneficial to the process.
Fulga and Thai entrepreneur Robert Clark founded Theravitae in 2003. Patients travel to Thailand for the extraction of the blood and wait less than a week while it is sent to Israel. There the stem cells are harvested and expanded and then shipped back to the Thai hospital where the operation to insert them is performed.
The total cost is about $35,000, including airfare and lodging, Fulga said.
Fulga said he expects to meet with FDA officials within six months and hopes to get approval to begin conducting trials in the United States.
Dr. Mark Zucker, director of heart failure and transplantation at Newark Beth Israel Medical Center in New Jersey, said therapy using adult stem cells is the way of the future. His center is considering working with Theravitae.
Zucker said that if doctors at Theravitae have discovered how to make stem cells heal heart tissue, this could be a real solution for tens of thousands of Americans, since only 2,300 hearts become available for transplant in the United States each year.
``I believe Theravitae is on the right track,'' Zucker said. ``I think if the company has identified an efficient way to procure cells and expand them, the company's impact will be revolutionary.''
The company presented its findings at a conference of the American Heart Association in Dallas in November. It has been chosen along with 35 other companies as a technology pioneer for 2006 by the World Economic Forum.
Pompili, of Case Western Reserve University, said he was working through a company called Arteriocyte on a similar procedure harvesting stem cells from bone marrow. He said his company and two other teams of doctors in the United States were conducting FDA trials using stem cell therapy to heal heart tissue.