Akio Koizumi1, Hirotake Masuda2, Yasuhiko Wada1, Mikako Tsukada1, Koichi Kawamura2, Sigetosi Kamiyama1, Roy L. Walford3
1Department of Hygiene, Akita University School of Medicine, Akita010, Japan
2The second department of Pathology, Akita University School of Medicine, Akita010 Japan
3Department of Pathology, University of California School of Medicine, Los Angeles, CA90024 U.S.A.