1. Laboratory of Immunology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
2. Laboratory of Radiation Immunology, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Korea.
3. Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, Jeju National University, Jeju 690-756, Korea.
4. Applied Radiological Science Research Institute, Jeju National University, Jeju 690-756, Korea.