1. Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom.
2. Austin Research Institute, Kronheimer Building, Austin Hospital, Heidelberg 3084, Australia.
3. Autoimmune Diseases Research, Merck Research Laboratories, Rahway, NJ 07065.
4. Department of Cellular and Molecular Pharmacology, Merck Research Laboratories, Rahway, NJ 07065.
5. Immunology Research, Merck Research Laboratories, Rahway, NJ 07065.