1. Center for Drug Design, Chemistry and Biochemistry Department, University of North Carolina Greensboro, P.O. Box 26170, 435 New Science Building, Greensboro, North Carolina 27402-6170, Chemistry & Life Sciences, RTI International, 3040 Cornwallis Road, Research Triangle Park, North Carolina 27709, California Pacific Medical Center Research Institute, 475 Brannan Street, Suite 220, San Francisco, California 94107, and Pharmacology and Toxicology Department, Medical College of Georgia, Augusta, Georgia 30912