Maximal oxygen uptake (exercise capacity) is a vital parameter in the evaluation of adaptation to high altitude, providing an index of the integrated function of the oxygen transport system. Previous studies of maximal oxygen uptake in population at high altitude have mainly focused on adults and adolescents, though data on children are uncommon. Maximal oxygen uptake can be measured directly, using an oxygen analyser, or indirectly through the development of equations for estimation from the maximal power output (W(max)). Such estimations and studies of the physiological aspects of children's capacity to work and live at different altitudes in Tibet ancestry were not reported previously, although differences similar to those seen in adults may be expected to occur. The present paper summarized the findings of studies on exercise capacity among children living at high altitude in Tibet.
Adaptation, Physiological ; Altitude ; Child ; Exercise Test ; Exercise Tolerance ; Humans ; Oxygen Consumption ; Tibet

Adolescent ; Foot Deformities ; genetics ; Humans ; Male

OBJECTIVETo study the chemical constituents in root of Phlomis medicinalis.

METHODThe compounds were isolated and repeatedly purified on macroporous resin, silica gel column chromatography, TLC and Prep-HPLC and the structures were elucidated by physico-chemical properties and NMR spectra.

RESULTEight compounds were obtained and elucidated as 5-Hydroxy-7-methoxy-4, 6-dimethylphthalide (1), 4-hydroxymethyl-2-furaldehyde (2) and six iridoid glucosides: 6-O-acetyl-shanzhiside methyl ester (3), 8-O-acetyl-shanzhiside methyl ester (4), shanzhiside methyl ester (5), sesamoside (6), phloyoside II (7) and dehydropentstemoside (8).

CONCLUSIONAll the compounds were isolated from the plant for the first time and 1 and 3 were obtained from the plants of Phlomis for the first time.

Benzofurans ; chemistry ; isolation & purification ; Glucosides ; chemistry ; isolation & purification ; Phlomis ; chemistry ; Plant Extracts ; chemistry ; isolation & purification ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Pyrans ; chemistry ; isolation & purification ; Terpenes ; chemistry ; isolation & purification

OBJECTIVEAim of our study was to compare hematological parameters in Tibetan natives with those in Han migrants living on the Tibet plateau in order to determine the potential effects of age, gender, and ethnicity on hematological response to hypoxia.

METHODSBlood hemoglobin (Hb, g/dl), hematocrit (Hct, %), red blood cells (RBC,10(6)/mm3) were measured in 3 588 healthy Tibetan natives and 3 371 Han migrants ranging in age from 5 to 72 years, living at a mean altitudes of 2 664 m, 3 813 m, 4 525m and 5 226 m.

RESULTSHemoglobin (Hb) concentration analysis was made by multiple regression equations relating hemoglobin to altitude and age. For 2 093 Han males, Hb = 9.612+ 0.001440xaltitude+ 0.06148xage. For 1 948 Tibetan males, Hb =12.202+ 0.000462xaltitude+ 0.02893xage. For 1 278 Han females, Hb = 10.858+ 0.000939xaltitude+ 0.02632xage. For 1 640 Tibetan females, Hb = 11.402+ 0.000626xaltitude+ 0.00412xage. Each of the four equations was statistically significant (P < 0.001), and had variance (r2) of 0.86 or more, indicating that altitude and age accounted for at least 85% of the variation in hemoglobin levels. The coefficients for altitude and for age were higher (P < 0.05) in Han males than in Tibetan males and higher (P < 0.05) in Han females than in Tibetan females. The Tibetan postmenopausal females had higher Hb values than premenopausal females only presented at altitude above 4 000 m while this phenomenon was beginning at altitude of 2 664 m among Han females.

CONCLUSIONWe conclude that gender and increasing age in Tibetans are associated with lower hemoglobin values than those in Han at high altitude, and we speculate that genetic factors seems to be important.

Adolescent ; Adult ; Aged ; Altitude ; Asian Continental Ancestry Group ; Child ; Child, Preschool ; Ethnic Groups ; Female ; Hematocrit ; Hemoglobins ; analysis ; Humans ; Hypoxia ; ethnology ; Male ; Middle Aged ; Tibet ; Transients and Migrants ; Young Adult

Objective To investigate the current prevalence of human intestinal protozoal infections in Tibet Autonomous Region, so as to provide the scientific basis for the development of the future control strategy. Methods The study sites were sampled using a stratified cluster random sampling method in different ecological zones and different geographical locations of Tibet Autonomous Region in 2015. Fecal samples were collected from the permanent residents at ages of 3 years and older for the detection of intestinal protozoa cysts and trophozoites. The region-, gender-, age-, occupation- and education level-specific prevalence of human intestinal protozoal infections was estimated and compared. Results A total of 70 study sites were sampled from 23 counties (districts) in 3 ecological zones of Tibet Autonomous Region in 2015. Among 17 939 subjects surveyed, there were 1 117 residents infected with intestinal protozoa, with a prevalence of 6.23%. There were 9 species of intestinal protozoa identified, and Entamoeba coli (3.59%), Giardia lamblia (0.74%) and Blastocystis hominis (0.72%) were found to have a high in- fection rate. The prevalence of human intestinal protozoal infections was 7.20%, 6.39% and 4.48% in the southern, eastern and northern Tibetan ecological zones, respectively. Among the 23 counties (districts), the highest human prevalence was seen in Baingoin (13.56%) and Amdo counties (12.77%), and there were significant differences in the prevalence of human intestinal pro- tozoal infections among the three ecological zones (χ2 = 33.909, P < 0.01) and 23 counties (districts) (χ2 = 580.511, P < 0.01). There was no gender-specific prevalence of human intestinal protozoal infections (men, 6.08%; women, 6.35%; χ2 = 0.542, P > 0.05); however, there was age-specific human prevalence (χ2 = 44.377, P < 0.01), and a higher prevalence was seen in residents at ages of 60－69 years (8.51%) and 50－59 years (7.67%). In addition, there were occupation- (χ₂ = 37.568, P < 0.01) and education level-specific prevalence rates of human intestinal protozoal infections (χ2 = 14.659, P < 0.01), and a higher prevalence was seen in farmers (7.17%) and herdsmen (5.28%), and in residents with a primary school education (6.62% and illiterate resi- dents (6.33%). Conclusions The prevalence of human intestinal protozoal infections remains high in Tibet Autonomous Region. The health education pertaining to intestinal parasitic disease control requires to be intensified among farmers and herds- men in rural areas.

Objective:To study the clinical characteristics and management strategies of patients with chronic obstructive pulmonary disease (COPD) in high-altitude areas.Methods:An observational cross-sectional study was conducted in 79 stable COPD patients who visited the outpatient of Respiratory Medicine at Tibet Autonomous Region People′s Hospital and Peking University Third Hospital from August 3 rd 2020 to November 30 th 2020. Patients were divided into Lhasa group ( n=44) and Beijing group ( n=35). The differences of clinical characteristics including demographic characteristics, risk factors, respiratory symptoms, comorbidities, medications and spirometry were analyzed. Further comparative analysis was conducted on the clinical characteristics of smokers ( n=15) and non-smokers ( n=29) in Lhasa group. Results:The proportion of female patients and biofuel exposure in Lhasa group was significantly higher than Beijing group (56.8% vs 0, 86.4% vs 0, both P<0.001). The proportion of smokers in Lhasa group was significantly lower than Beijing group (34.1% vs 100%, P<0.001). The mean score of COPD assessment test (CAT) in Lhasa group was significantly higher than Beijing group (21.27 vs 9.17, P<0.001). The proportion of acute exacerbations ≥2 in the past year in Lhasa group was significantly higher than Beijing group (31.8% vs 11.4%, P=0.032). The median percentage of forced vital capacity in the first second of predicted value (FEV 1%pred) of patients in Lhasa group was significantly higher than Beijing group (63% vs 38%, P<0.001). The proportion of patients treated by inhaled corticosteroid/long-acting β 2-agonist (ICS/LABA) and inhaled long-acting muscarinic antagonists (LAMA) in Lhasa group was significantly lower than Beijing group (4.5% vs 60.0%, 0 vs 65.7%, both P<0.001). There were no significant differences in CAT score, number of acute exacerbations in the past year and lung function between smokers and non-smokers in Lhasa group. Conclusions:Compared with those patients in Beijing, the majority of patients with COPD living in Lhasa are female, with a low proportion of smokers and a high proportion of biofuel exposure. Although their lung function is better, their respiratory symptoms are more severe with more acute exacerbations in the past year, and most patients do not receive standardized medication.

A pharmacophore-based study was conducted to investigate the therapeutic activity of the traditional Tibetan medicine Zha Xun (ZX) in liver diseases. In the present study, the protective effect of ZX on the acute liver injury induced by concanavalin A (ConA) and 0.15% carbon tetrachloride (0.15% CCl₄) in ICR mice was evaluated, and the results showed that ZX significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the ConA-induced acute immune liver injury model and the CCl₄-induced acute oxidative liver injury model (P < 0.05). Subsequently, the protective effects of aqueous, 95% ethanol, 60% ethanol and 30% ethanol eluting fractions of ZX, and fulvic acid, the main water-soluble constituent of ZX, were evaluated against acute oxidative liver injury induced by 0.15% CCl₄ in mice. The results showed that different solvent-eluting fractions of ZX showed certain hepatoprotective activities, among which the aqueous extract of ZX and 30% ethanol extract of ZX significantly reduced the serum levels of ALT, AST, and lactate dehydrogenase (LDH) in mice (P < 0.05), and the serum levels of LDH in mice were significantly reduced by fulvic acid (P < 0.05), which showed significant hepatoprotective activity. The protective activities and preliminary mechanisms of the total extract of ZX, the aqueous extract of ZX, the 30% ethanol extract of ZX, and fulvic acid against hepatocellular injury in vitro were further evaluated by using the H₂O₂-induced hepatocellular injury model. The results showed that the components could significantly inhibit H₂O₂-induced hepatocellular injury, reduce the levels of ALT, alkaline phosphatase (ALP), and LDH, improve the survival rate of hepatocellular cells, and reduce the content of intracellular reactive oxygen species (ROS) in cell culture. At the same time, it can inhibit hepatocyte apoptosis by increasing the expression ratio of Bcl-2/BAX protein and decreasing the expression ratio of cleaved caspase-3/pro caspase-3 protein. The present study showed that ZX has clear hepatoprotective activity in vitro and in vivo, and the different solvent elution fractions of ZX showed certain hepatoprotective activity, among which the aqueous extract of ZX, 30% ethanol extract of ZX had better hepatoprotective activity, and the activity of 60% ethanol extract of ZX was stronger than that of 95% ethanol extract of ZX. The activity of ZX and its water-soluble elution site exerted hepatoprotective effects by inhibiting hepatocyte apoptosis and oxidative stress. The animals used in this experiment and related disposal meet the requirements of animal welfare, and have been reviewed and approved by the Laboratory Animal Management and Use Committee of the Institute of Materia Medica, Chinese Academy of Medical Sciences (approval number: 00004018).

Altitude ; China/epidemiology* ; Community-Acquired Infections/epidemiology* ; Humans ; Pneumonia/etiology* ; Tibet