The third leading cause of death and a leading cause of disability, stroke occurs when blood flow to the brain is interrupted by a blockage or a rupture in an artery, depriving brain tissue of oxygen. The only current treatment for ischemic stroke, the most prevalent kind, is the clot-buster tPA; however, only one-third of patients respond well to tPA, so researchers continue to explore other therapies.   Researchers from The University of Texas Health Science Center at Houston (UTHealth; Texas, USA) reported on results of a Phase I trial of a patient’s own bone marrow stem cells to treat acute stroke.  The trial is the first ever to harvest an acute stroke patient’s own stem cells from the iliac crest of the leg, separate them and inject them back into the patient intravenously. The first patient was enrolled in March 2009, and since then enrolled an additional 10 patients.  There were no study-related severe adverse events. Stroke symptom  severity as measured by standardized scales improved in most patients, at the 3-month and 6-month marks.  The team submits that:  “This study suggests that a bone marrow harvest and reinfusion of autologous [mononuclear cells] were safe and feasible in acute stroke patients.”