Jennifer Mathews: Winefred Cooley knows a thing or two about pain.

Winefred Cooley: For a year or more, I had been getting up at night. It wakes me up, and I'd sit on the easy chair and just hold my foot. It was just terrible, terrible pain.

Jennifer Mathews: Peripheral arterial disease was wreaking havoc on her legs. She even developed gangrene in her toes. Doctor Jeffrey Lawson says pain comes as a result of blocked arteries in the leg.

Jeffrey Lawson: It's almost if you can imagine traveling on a freeway. Here, where you're on the highway traveling quite briskly, and the freeway hits a block.

Jennifer Mathews: Because her arteries were so damaged, Winefred was not a candidate for standard bypass therapy.

Jeffrey Lawson: There's no target vessel below an area of blockage that can be reconstructed.

Jennifer Mathews: Faced with the possibility of amputation, Winefred chose an experimental stem cell treatment.

Jeffrey Lawson: We designed a project to take adult stem cells isolated from a patients' own bone marrow and inject them into the leg.

Jennifer Mathews: Twelve weeks later, Winefred's leg shows signs of regenerating blood vessels.

Winefred Cooley: Now I can sleep the night through. It is unreal. Well, it's just more than I can ask for really.

Jennifer Mathews: Two patients have had the treatment at Duke University, and both have shown improvement.

Jeffrey Lawson: They feel dramatically better, and both of them still have their feet where they were both candidates for amputation.

Jennifer Mathews: Now, Winefred looks forward to the day she can return to her daily walks without pain. This is Jennifer Mathews reporting.