1. Department of Veterinary Internal Medicine and Geriatrics, College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, Republic of Korea
2. Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Republic of Korea
3. Department of Neurology, Seoul National University Hospital, Seoul 110-744, Republic of Korea
4. Department of Anatomy, College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, Republic of Korea
5. Department of Biomedical Laboratory Science, College of Medical Sciences, Soonchunhyang University, Asan 336-745, Republic of Korea
6. Department of Veterinary Internal Medicine, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Republic of Korea