Department of Gastroenterology and Hepatology;
People's Hospital of Zhengzhou University;
Henan Province;
China;
Henan Provincial People’s Hospital;
Henan Province;
China;
Henan University School of Medicine;
Zhengzhou 450003;
Henan Province;
China;
Helicobacter pylori; Chronic gastric diseases; Gastrin-17; Pepsinogen; Gastric cancer;