[Microcirculation characteristics and humoral factors of healthy people from different populations at high altitude (4 100 m)].

The present study was aimed to observe the characteristics of sublingual microcirculation and the changes of humoral factors in healthy people of three different high altitude populations. Three groups of healthy subjects in Guoluo area of Qinghai province (4 100 m) were included: Tibetan group: 30 Tibetans, (45.62 ± 10.15) years old; Han group: 22 two-generation of Han immigrants, (46.23 ± 8.59) years old; migrant group: 23 migrants living at high altitude for 2-5 years, (43.45 ± 8.31) years old. Blood routine test was performed to determine white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB), hematocrit (HCT), platelet (PLT) count, and neutrophil (NEUT) count. The changes of serum humoral factors including endothelin-1 (ET-1), CD31, CD34, CD105, vascular endothelial growth factor (VEGF), nitric oxide (NO) and noradrenaline (NE) were detected by ELISA. Continuous noninvasive hemodynamics monitor was used to continuously measure the changes of systemic circulation indexes: cardiac output (CO), cardiac index (CI), heart rate (HR), stroke volume (SV), pulse pressure variation (PPV), systemic vascular resistance index (SVRI), and mean arterial pressure (MAP). Blood oxygen was measured by pulse oximeter. Sublingual microcirculation indexes including total vascular density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI) were determined by sidestream dark field imaging. The results showed that there were no difference in systemic circulation among the 3 groups. Compared with Tibetan group, TVD and PVD of microcirculation in Han group and migrant group were significantly increased (P < 0.05). Compared with Tibetan group and Han group, WBC, RBC, HGB and HCT of migrant group were significantly increased (P < 0.05). Compared with Han group and Migrant group, PLT of Tibetan group was significantly increased (P < 0.05). Compared with the Tibetan group, the levels of serum humoral factors CD105 and VEGF were significantly higher in the migrant group (P < 0.05), while compared with Han and migration groups, NO in Tibetan group was significantly increased (P < 0.05). It is suggested that there were significant differences in microcirculation (TVD, PVD), blood routine (WBC, RBC, HGB, HCT) and humoral factors (CD105, VEGF) among different populations in high altitude area. Importantly, the increased microcirculation, erythrocytosis and increased pro-angiogenic factors due to hypoxic environment were observed in long-term residents and migrants, except for permanent residents. These physiological changes have clinical significance in the treatment of septic shock and chronic altitude sickness for different plateau populations.

[Characteristics of circulation and microcirculation in healthy people of Han nationality at different altitudes].

Objective: To observe the circulation and microcirculation characteristics of healthy han people in Qinghai at different Guoluo (4 100 m) and Huzhu (2 600 m) and in Shanghai in plain area (4 m). Methods: The 28 healthy han people aged (45.62±10.15) from Guoluo in Qinghai, 27 healthy han people aged (47.25±8.43) from Huzhu in Qinghai and 20 healthy han people aged (43.12±8.28) from Shanghai were divided into three groups: Guoluo group (GL), Huzhu group (HZ) and Shanghai group (SH); Venous blood was collected for routine blood test: red blood cells count(RBC), hemoglobin(HGB), hematocrit(HCT), platelet(PLT); and coagulation index: prothrombin time(PT), interntionl normlized ratio(INR), fibrin(Fib), activated partial thromboplastin time (APTT), thrombin time(TT), continuous non - invasive hemodynamic monitor (CNAP) was used for continuous measurement: cardiac output (CO), heart rate (HR), stroke volume (SV), pulse pressure variation rate (PPV), systemic vascular resistance index (SVRI), mean arterial pressure (MAP); pulse oxygen monitoring instrument is used for monitoring SPO2 (pulse oxygen); the total vascular density (TVD), perfusion vascular density (PVD), proportion of perfused vascular(PPV), and microvascular flow index (MFI) of sublingual microcirculation were observed by using peripheral dark field imaging (SDF) monitoring technique. Results: Compared with the Shanghai group, the RBC and HGB levels in the Huzhu group and the Guoluo group were significantly increased (P＜0.05), while PLT levels were significantly decreased (P＜0.05); The levels of PT, Fib, APTT, TT, CO, HR, SV, MAP and SPO2 in the Huzhu group were significantly decreased (P＜0.05), while the levels of TVD, PVD, PPV and MFI were significantly increased (P＜0.05). In Guoluo group, the levels of HCT, Fib, CO, SV, PPV, MAP, TVD and PVD were significantly increased (P＜0.05), while the levels of PT, INR, TT and SPO2 were significantly decreased (P＜0.05). Compared with the Huzhu group, the levels of RBC, HGB, HCT, Fib and APTT of Guoluo group were significantly increased (P＜0.05); while the levels of SPO2, TVD, PVD, INR and TT were significantly decreased (P＜0.05). Conclusion: The microcirculation of healthy people in different altitude areas is significantly different, and the microcirculation density of healthy people in high altitude areas is significantly higher than that in plain areas, especially in moderate altitude areas. Its special physiological significance is of guiding significance for the treatment of infectious shock and chronic altitude disease in plateau areas.

Dynamic changes in peripheral blood-targeted miRNA expression profiles in patients with severe traumatic brain injury at high altitude.

BACKGROUND: The aim of this work is to detect and compare the peripheral blood miRNA expression profiles in patients with severe traumatic brain injury (sTBI) 2, 12, 24, 48, and 72 h after injury at high altitude and to predict the target genes of differential expressed miRNAs. METHODS: Twenty sTBI patients from high-altitude areas were randomly selected according to the inclusion and exclusion criteria and were divided into five groups: the 2-h group, 12-h group, 24-h group, 48-h group, and 72-h group. Peripheral blood miRNA expression profiles were detected using real-time quantitative PCR (qRT-PCR). RESULTS: The expression levels of miR-18a, miR-203, miR-146a, miR-149, miR-23b, and miR-let-7b in peripheral blood showed significant differences between the 2-h group and the 12-h group. The expression levels of miR-203, miR-146a, miR-149, miR-23b, and miR-let-7f in peripheral blood were up-regulated in the 24-h group. In the 48-h group, the expression levels of miR-181d, miR-29a, and miR-18b were upregulated. In the 72-h group, the expression levels of miR-203, miR-146a, miR-149, miR-23b, and miR-let-7f changed. The main target genes of the differentiation expressed miRNAs were genes that regulate inflammatory responses, apoptosis, and DNA damage/repair. CONCLUSIONS: miRNAs may be involved in the pathogenesis of sTBI by dynamically regulating the target genes that regulate inflammatory responses, apoptosis, and DNA damage/repair pathways.

[Effects of early mechanical ventilation on oxygenation and hemodynamics in acute high altitude pulmonary edema patients complicated by acute respiratory distress syndrome].

OBJECTIVE: To investigate the effect of early mechanical ventilation on oxygenation and hemodynamic of acute high altitude pulmonary edema (HAPE) patients complicated by acute respiratory distress syndrome (ARDS). METHODS: From May 2001 to December 2006, 8 HAPE patients with secondary ARDS admitted to Germud City People's Hospital were enrolled in the study. All the patients received early invasive mechanical ventilation within 24 hours of HAPE. Hemodynamics, cardiac output, arterial and mixed venous blood gas and oxygen dynamics parameters were determined before and after 96 hours of mechanical ventilation. RESULTS: Before treatment the right atrial pressure (RAP), mean pulmonary artery pressure (mPAP), pulmonary vascular resistance index (PVRI) and shunt (Qs/Qt) were above normal values. Oxygen delivery (DO2), oxygen extraction rate (O2ER), and oxygenation index (PaO2/FiO2) were lower than normal values. After treatment with mechanical ventilation, arterial partial pressure of oxygen (PaO2), PaO2/FiO2, arterial oxygen saturation (SaO2), partial pressure of oxygen of mixed venous blood (PVO2) and mixed venous oxygen saturation (SVO2) were increased significantly compared with those before treatment [PaO2: 70.3±2.9 mm Hg (1 mm Hg=0.133 kPa) vs. 49.9±3.5 mm Hg, t=15.292, P=0.001; PaO2/FiO2: 201.6 ± 4.8 mm Hg vs. 134.5±5.2 mm Hg, t=19.618, P=0.004; SaO2: 0.929±0.021 vs. 0.780±0.073, t=6.226, P=0.002; PVO2: 54.8±2.9 mm Hg vs. 44.9±2.6 mm Hg, t=6.767, P=0.002; SVO2: 0.726±0.017 vs. 0.663±0.053, t=3.262, P=0.008]. Heart rate (HR), RAP, mPAP, pulmonary wedge pressure (PAWP), PVRI, right ventricular stroke work index (RVSWI) and Qs/Qt were decreased significantly compared with those before mechanical ventilation [HR: 73±2 bpm vs. 102±13 bpm, t=6.228, P=0.000; RAP: 6.9±1.0 mm Hg vs. 13.9±1.5 mm Hg, t=3.609, P=0.008; mPAP: 18.5±2.9 mm Hg vs. 41.6±3.0 mm Hg, t=4.773, P=0.000; PAWP: 6.9±2.2 mm Hg vs. 14.0±4.2 mm Hg, t=2.747, P=0.030; PVRI: 26.3±1.7 kPa×s×L(-1) vs. 49.6±10.0 kPa×s×L(-1), t=9.861, P=0.000; RVSWI: 11.0±1.9 g×cm(-1)×min×m(2) vs. 22.0±1.5 g×cm(-1)×min×m(2), t=12.704, P=0.000; Qs/Qt: (26±18)% vs. (35±15)%, t=7.603, P=0.000], and cardiac index (CI), DO2, oxygen consumption (VO2) and O2ER were also increased [CI: 71.68±6.67 mL×s(-1)×m(-2) vs. 70.01±6.67 mL×s(-1)×m(-2), t=2.832, P=0.036; DO2 (L×min(-1)×m(-2)): 460.9±14.0 vs. 410.0±3.1, t=9.268, P=0.000; VO2 (L×min(-1)×m(-2)): 158.5±9.2 vs. 129.9±5.3, t=2.818, P=0.004; O2ER: (20±1)% vs. (18±1)%, t=7.652, P=0.000]. All of the 8 patients survived. CONCLUSIONS: Pulmonary circulation hemodynamic and oxygen dynamic disorders were found in HAPE patients with secondary ARDS. Treatment with early mechanical ventilation not only improved oxygenation but also reduced pulmonary hypertension and increased cardiac output and DO2.