1. Department of Neurology; Saitama Medical University; Saitama Japan
2. Department of Pathology; Saitama Medical University; Saitama Japan
3. Hokkaido University Graduate School of Veterinary Medicine; Hokkaido Japan
4. Department of Pathology; Tokyo Metropolitan Neurological Hospital; Tokyo Japan
5. Division of CJD Science and Technology, Department of Prion Research, Center for Translational and Advanced Animal Research on Human Diseases; Tohoku University Graduate School of Medicine; Miyagi Japan