1. College of Nursing, Seoul National University, Seoul 110-744, Korea.
2. Department of Neuropsychiatry, Graduate School of Oriental Medicine, Dongguk University, Goyang 410-773, Korea.
3. Department of Nursing, Cheongju University, Cheongju 360-764, Korea.
4. Dongguk University Research Institute of Biotechnology, Seoul 100-715, Korea.