1. Division of PathologyNational Institute of Health Sciences 3‐25‐26 Tonomachi, Kawasaki‐ku Kawasaki 210‐9501 Japan
2. Laboratory of Veterinary PathologyTokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐cho, Fuchu Tokyo 183‐8509 Japan
3. Department of PathologySaiseikai Utsunomiya Hospital 911‐1 Takebayashi‐machi, Utsunomiya Tochigi 321‐0974 Japan