1. Department of Pathology, General Hospital of The Tibetan Military Region of The Chinese People's Liberation Army, Lhasa, Tibet Autonomous Region 850000, P.R. China
2. Basic Department, Medical College of Tibet University, Lhasa, Tibet Autonomous Region 850000, P.R. China
3. Department of Respiratory and Critical Care Diseases, The People's Hospital of Tibet Autonomous Region, Lhasa, Tibet Autonomous Region 850000, P.R. China
4. Department of Digestive System, The People's Hospital of Tibet Autonomous Region, Lhasa, Tibet Autonomous Region 850000, P.R. China
5. Department of Pathology, Lhasa People's Hospital, Lhasa, Tibet Autonomous Region 850000, P.R. China