1. Department of Neurosurgery; Dokkyo Medical University Koshigaya Hospital; 2-1-50 Minami-Koshigaya Koshigaya-shi Saitama 343-8555
2. Department of Human Pathology; Gunma University Graduate School of Medicine; 3-39-22 Showa-machi Maebashi-shi Gunma 371-8511 Japan