1. Duke Clinical Research Institute; P.O. Box 17969 Durham NC 27715 USA
2. Glaxo Wellcome, Inc.; P.O. Box 13398, Research Triangle Park NC 27709 USA
3. Department of Cardiology; Northwestern University Medical Center; 250 East Superior Street #524 Chicago IL 60611 USA
4. Department of Medicine; University of North Carolina at Chapel Hill; 333 Burnett Womack Chapel Hill NC 27599 USA
5. Department of Cardiology and Thoracic Surgery, Ostra University; Sahlgrenska Hospital; SE-416 85 Göteborg Sweden