1. From the Division of Pediatric Surgery (Y.S., J.E.B., J.S., K.A.P.) and Cardiothoracic Surgery (J.S.T.), The Cardiovascular Center (Y.S., J.E.B., C.Z., K.A.P.), Free Radical Research Center (K.A.P., J.E.B., Y.S.), and Departments of Biochemistry (J.E.B.), Physiology (C.Z.), and Pharmacology and Toxicology (K.A.P.), Medical College of Wisconsin; and the Section of Cardiothoracic Surgery (J.S.T.), Children’s Hospital of Wisconsin, Milwaukee, Wis.