A new discovery that tricks aging stem cells into rejuvenating mode could enable scientists to create youthful patches for damaged or diseased hearts and heal them according to a Canadian study. The breakthrough may enable scientists to create such life giving patches from a patient's own stem cells - regardless of the patient's age - while avoiding the threat of rejection the study claims. A stem cell therapy involving donated bone marrow stem cells run the risk of patient rejection among many people argues Milica Radisic associate professor of chemical engineering and applied chemistry at the University of Toronto the