Objective To investigate the impact of high altitude on human gastric mucosa and its underlying mechanisms. Methods Twenty-five native Tibetans with chronic mountain sickness CMS residing at high altitude (4500 m) were examined for ultrastrueture and pathological changes of gastric mucosa. The other 25 native Tibetans residing at low altitude (＜2000 m) were served as control.The expression of hypoxia-inducible factor (HIF)-1α in human gastric mucosa was detected with immunohistochemistry. Results The color of gastric mucosa presented dark in patients with CMS.The histopathological examination showed significant differecnce in incidence of cnronc body gastritis and atrophic gastritis between CMS group and control group (P＜0. 05). The transmission electronic microscopy revealed that the epithlieal cells of gastric mucosa were impared in CMS group compared to control group. The expression of HIF-1α protein was increased in CMS group in comparison of control group (102.94± 34.04 vs 14.04 ± 6.53, P＜0.05). Conclusions The high altitude may involve in damage of gastric mucosa and the up-regulation of HIF-1α protein may involve in its mechanism.

Objective:To explore the value of 5G robotic remote ultrasound in the diagnosis of plateau pulmonary edema(HAPE).Methods:A total of 27 patients who quickly entered Nagqu, Tibet at an altitude of 4 600 m-5 600 m from March to December 2021 and developed one of the clinical symptoms of HAPE were collected. All patients were examined by 5G remote robotic ultrasound and lung CT respectively. Kappa test was used to analyze the consistency of the two diagnostic results, and McNemar test was used to compare the difference in diagnostic results. The ROC curve was used to analyze the sensitivity and specificity of remote lung ultrasound scores in the diagnosis of HAPE.Results:Among the 27 patients, 16 showed thickening of pleural line, increasing of B line, lung consolidation, pleural effusion, etc. Meanwhile, 11 showed no abnormality. Additionally, 8 cases had diffuse pulmonary fluid in both lungs, and 8 cases had localized pulmonary fluid. ROC curve showed that the area under the curve of lung ultrasound score for the diagnosis of HAPE was 0.947 (95% CI=0.78-0.99, P<0.001). The sensitivity and specificity were 0.933 and 0.917, respectively. Lung CT diagnosis was positive in 15 cases. Lung CT showed thickening of lung texture, ground glass, small nodular shadow, fine reticulate shadow, etc. The diagnostic results of the two techniques were in good agreement (Kappa=0.924, P<0.001), and there was no significant difference between the two methods ( P>0.05). Conclusions:5G remote robotic ultrasound has high consistency with CT in the diagnosis of HAPE and is an alternative early diagnosis method for HAPE. It may have clinical application value in scattered medical resources and remote plateau areas.