AUDIO: Listen to Richard Burt, M.D., associate professor of medicine at the Northwestern University Feinberg School of medicine, discuss his research.

CHICAGO --- The majority of patients with Type 1 diabetes who underwent transplantation with their own stem cells to reset their immune systems became insulin free, several for more than three years.

Richard Burt, M.D., co-author of the study and associate professor of medicine at the Northwestern University Feinberg School of Medicine, reports these patients also showed an increased level of a substance that indicates improved functioning of their beta cells, a cell in the pancreas that secretes insulin. The substance is C-peptide, a byproduct of insulin production.

The study was published in the April 15 Journal of the American Medical Association.