1. Department of Gastroenterology, Affiliated Hospital of Chengde Medical University, Chengde, Hebei 067000, P.R. China
2. Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, P.R. China
3. Department of Surgery, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor 43400, P.R. China
4. Department of Pathology, Hospital Kuala Lumpur Jalan Pahang, Kuala Lumpur 50586, Malaysia