1. University of Miami School of Medicine, Miami, Florida 33136.
2. Abbott Laboratories, Abbott Park, Illinois 60064.
3. Service d'Hépatologie et de SIDA, Hôtel-Dieu, Hospices Civils de Lyon, Lyon, France.
4. Therapeutic Concepts, Houston, Texas 77004.
5. Chelsea and Westminster Hospital, London, UK.
6. Duke University Medical Center, Durham, North Carolina 27706.