1. E. Takimoto, J. Ishida, K. Murakami, A. Fukamizu, Institute of Applied Biochemistry and Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Ibaraki 305, Japan.
2. F. Sugiyama, Laboratory Animal Research Center, University of Tsukuba, Ibaraki 305, Japan.
3. H. Horiguchi, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki 305, Japan.