1. From the Abboud Cardiovascular Research Center, Division of Cardiovascular Medicine, Department of Internal Medicine (I.M.G., E.K.N.), University of Iowa, Iowa City
2. Free Radical and Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center (I.M.G.), University of Iowa, Iowa City
3. Iowa City VA Health Care System (I.M.G.).