1. Safar Center for Resuscitation Research, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
2. Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania.
3. Consultants in Veterinary Pathology, Inc., Murrysville, Pennsylvania.
4. Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania.
5. Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania.