1. From the Second (K. Tamura, S.U., N.N., S.Y., T.I., N.T., M.I.) and Third (T.Y., S.T., H.S.) Departments of Internal Medicine, Yokohama City (Japan) University School of Medicine, and Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan (K. Tanimoto, K.M.).