1. Department of Radiology, College of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Korea.
2. Medical Research Center, College of Medicine, Yonsei University, Seoul 120-752, Korea.
3. Animal Science Branch, National Cancer Center, Koyang 410-769, Korea.
4. Department of Materials Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea.
5. Department of Anatomy and Cell Biology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea.
6. BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, Korea.
7. Department of Internal Medicine, College of Veterinary Medicine, Jeju National University, Jeju 690-756, Korea.
8. Institute of Physics, Academia Sinica, 128 Academic Rd., Nankang, Taipei 11529, Taiwan.
9. Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Korea.