1. Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
2. Department of Microbiology and Immunology, National Defense Medical Center, Taipei 114, Taiwan
3. Department of Obstetrics and Gynecology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
4. Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 114, Taiwan
5. Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan