Department of Internal Medicine, Department of Pediatrics, Center for Immunology, and Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110; Department of Immunology, G. D. Searle and Company, St. Louis, MO 63198; and First Department of Internal Medicine, School of Medicine, Ehime University, Shigenobu, Ehime 791-02, Japan(1997-08-05時点)