1. Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan
2. Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan
3. Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung 413, Taiwan
4. Nursing Department, Yuanpei University, Hsinchu 300, Taiwan