1. Department of Molecular Biology, Pusan National University, Busan 609–735, Korea;
2. Division of Brain Diseases, Center for Biomedical Sciences, Korea National Institute of Health, Chungcheongbuk-do 363–951, Korea;
3. National Radiation Emergency Center, Korea Institute of Radiological & Medical Sciences, Seoul 139–706, Korea; and
4. Research Institute of Genetic Engineering, Pusan National University, Busan 609–735, Korea