Institution: | 1Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.;2Department of Veterinary Medicine, Cheju National University, Jeju 690-756, Korea.;3School of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, Korea.;4Department of Laboratory Animal Medicine, College of Veterinary Medicine, Konkuk University, Seoul 143-701, Korea. |