United Press International

　　Friday, December 17, 2004

　　HOUSTON, Dec 16, 2004 (United Press International via COMTEX) —— Texas scientists who injected human stem cells into the ailing hearts of mice found the stem cells integrated with the heart cells to start healing.

　　The experiment at the University of Texas in Houston found the stem cells morphed into two kinds of cells to help restore heart function —— cardiac muscle cells that contract the heart and endothelial cells that line the heart's blood vessels.

　　The stem cells approached the healing in two ways. In the case of the cardiac cells the human stem cells "fused" onto the mouse cells resulting in new muscle cells with both human and mouse DNA. To repair the blood vessel walls, the human cells differentiated on their own into compatible cells, presumably to patch the damage.

　　Two months after the stem cells were administered the researchers reported about two percent of the heart cells in the treated mice showed evidence of a human genetic marker.