The deacclimatization symptom scores of 159 youth returning to the same plain from different plateau / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analysis deacclimatization symptom scores of 159 youth from Karakoram and Tibet Ali area, and provide the basis for the development of relevant prevention and control measures.</p><p><b>METHODS</b>Using the method of epidemiological symptoms questionnaire, 18 symptoms of 190 youth who returned to the plain area from the different plateau were investigated. The symptom scores of different altitude, age, the time of staying, different units, continuous or intermittent stage and education were surveyed.</p><p><b>RESULTS</b>Deacclimatization symptom scores among 5,000 meter groups were significantly higher than those of 4,300 meter and 3,700 meter group (P < 0.05, P < 0.01). There was no significant difference between the 4,300 meter group and the 3,700 meter group (P > 0.05). There were significant differences among the stayed personnel (different age, position, unit, education, time, continuous or intermittent) (P < 0.01). There was significant difference between the continuous defended the group and intermittent group (P < 0.01).</p><p><b>CONCLUSION</b>Deacclimatization symptom scores were related to the plateau exposure time, altitude, workload, plateau continued exposure. The older, the longer exposure, the higher altitude, the greater workload at plateau were showed higher deacclimatization symptom score.</p>

Relationship of high altitude de-adaptation with acute high altitude response and cardiac function / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To assess the relationship of high altitude de-adaptation response (HADAR) with acute high altitude response (AHAR) and cardiac function.</p><p><b>METHODS</b>Ninety-six military personnel of rapid entering into high altitude (3 700 to 4 800 m) with strong physical work were analyzed, all subjects were male, aged 18 - 35 years. According to the symptomatic scores of AHAR were divided into 3 groups: sever AHAR (group A, 24), mild to moderate AHAR (group B, 47) and non-AHAR (group C, 25) at high altitude. According to the symptomatic scores of HADAR were divided into 3 groups: severe HADAR (group E, 19), mild to moderate HADAR (group F, 40) and non-HADAR (group G, 37) after return to lower altitude (1 500 m). Mean pulmonary arterial pressure (mPAP), right ventricular internal dimension (RVID), outflow tract of right ventricle (RVOT), left ventricular internal dimension (LVID), left ventricular ejection fraction (LVEF), cardiac muscle work index (Tei index), creatine kinase isoenzymes-MB (CK-MB), lactic dehydrogenase isoenzyme-1 (LDH-1) were measured at high altitude stayed 50 days and after return to lower altitude 12 h, 15 d, and 30 d. Fifty healthy volunteers (group D) at 1 500 m altitude served as control.</p><p><b>RESULTS</b>Level of mPAP, RVID, RVOT, RVID/LVID ratio, Tei index, CK-MB,and LDH-1 were higher, and LVEF was lower in group A than those in group B, C and D, there were significant differences between group B and C, C and D (all P < 0.01). AHAR scores were positively correlated with HADAR scores (r = 0.863, P < 0.01). Twelve hours after return to lower altitude, level of mPAP, RVID, RVOT, RVI/LVID ratio, Tei index, CK-MB, and LDH-1 were higher, and LVEF was lower in group E than those in group F, G and D, there were significant differences between group F and G, G and D (all P < 0.01). Fifteen days after return to lower altitude, level of mPAP, RVID, RVOT, RVID/LVID ratio were higher in group E than those in group F, G, and D, there were significant differences between group F and G, and D (P < 0.01 or P < 0.05), there were no significant differences between group G and D (all P > 0.05), LVEF, Tei index, CK-MB, LDH-1 showed no significant differences among groups (all P > 0.05). Thirty days after return to lower altitude, these parameters in group E, F, and G showed no significantly differences compared with those of group D (all P > 0.05).</p><p><b>CONCLUSION</b>The severity of HADAR is associated with severity of AHAR and cardiac injury, the more serious of AHAR and cardiac injury at high altitude, the more serious of HADAR and cardiac injury after return to lower altitude, the more long of restore of right cardiac morphologic injury.</p>

Therapeutic intervention against deacclimatization to high altitude / 中国应用生理学杂志

The incidence of deacclimatization to high altitude syndrome (DAHAS) prevailed up to 80% in highland troops, and 100% in manual workers, and severe DAHAS could significantly affects patients' health, work and life. So it is imperative to develop effective prevention and treatment measures for DAHAS. The present review analyzes effective prophylactic and therapeutic measures against DAHAS, implemented at our hospital.

Effect of oxidative stress in development of acute high altitude response during the process of strong physical work at high altitude / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To assess the effect of oxidative stress in development of acute high altitude response (AHAR) during the process of strong physical work at high altitude and its change after return to lower altitude.</p><p><b>METHODS</b>Ninety-six officers and soldiers of rapid entering into high altitude (3 700 m) with strong physical work were analyzed, all subjects were male, aged 18-35 years. According to the symptomatic scores of AHAR were divided into 3 groups: severe AHAR (group A, n = 24), mild AHAR (group B, n = 47) and without AHAR (group C, n = 25). Levels in serum 8-iso prostaglandinF2alpha(8-iso-PGF2alpha), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured at higher altitude stayed 50 d and after return to lower altitude (1 500 m) 12 h and 15 d, and 50 healthy volunteers (group D) at 1 500 m altitude served as controll.</p><p><b>RESULTS</b>Levels of serum 8-iso-PGF2alpha and MDA [(9.53 +/- 0.47) microg/L, (8.91 +/- 0.39) micromol/L] were significantly higher in group A than those in group B [(8.34 +/- 0.42) microg/L, (7.31 +/- 0.32) micromol/L] , group C [(7.02 +/- 0.48) microg/L, (6.41 +/- 0.23) micromol/L] and group D [(5.13 +/- 0.56) microg/L, (5.48 +/- 0.33) micromol/L], (all P < 0.01), and serum SOD [(52.08 +/- 3.44) micro/ml] was significantly lower in group A than that in group B [62.27 +/- 2.54) micro/ml], group C [(71.99 +/- 3.35) micro/ml] and group D [(80.78 +/- 3.44) micro/ ml] (all P < 0.01), there were significant differences between group B and C, C and D (all P < 0.01). At altitude 3 700 m 50 d, AHAR scores was positively correlated with serum 8-iso-PGF2alpha and MDA (all P < 0.01), negatively correlated with SOD (P < 0.01). Serum 8-iso-PGF2alpha and MDA were negatively correlated with SOD (all P < 0.01). Levels of serum 8-iso-PGF2alpha and MDA were significantly higher at altitude of 3 700 m 50 d than those at altitude of 1 500 m 12 h,15 d in group D (all P < 0.01), and serum SOD was significantly lower than that at 1 500 m 12 h,15 d in group D (all P < 0.01), there were significantly difference between at 1 500 m 12 h and 15 d (all P < 0.01), there were no difference between at 15 d in group D (all P > 0.05).</p><p><b>CONCLUSION</b>The more serious of oxidative stress and oxidative/antioxidative imbalance, the more serious of AHAR, oxidative stress and oxidative/antioxidative imbalance may be involved in the development of AHAR. The changes were obviously improved after return to lower altitude 12 h, and recovered to normal after 15 d.</p>

Correlation and influences of inflammatory mediators on permeability of the blood-brain barrier at high altitude exposure / 中国应用生理学杂志

<p><b>AIM</b>To investigate the influences of inflammatory mediator on permeability of the blood-brain barrier(BBB) at high altitude environmental exposure as well as relationship and water content in brain.</p><p><b>METHODS</b>Wistar rats were exposed to different altitude gradients, then brain tissue homogenate was prepared, and the activities of tumor necrosis factor-alpha (TNFalpha) and endothelin (ET) in brain tissue homogenate were measured by radioimmunoassay methods. The activities of nitric oxide (NO) in brain tissue homogenate were measured by chemical methods. The evans blue (EB) content in brain tissue was determined by colorimetry and the wet weight/dry weight ratio (W/D) was used to express the water content in brain.</p><p><b>RESULTS</b>With altitude going up, the activities of TNFalpha, NO and ET in the brain of rats rose, and they also rose gradually with time prolonging under high altitude hypoxia exposure. Their most obvious rise was seen during 9 days after ascending 5 000 m high altitude regions. At the same time, the EB and water content in the brain of mice showed the same change trends. Therefore, the inflammatory mediator activity and EB content as well as water content in brain showed an evidently linear relationship.</p><p><b>CONCLUSION</b>The inflammatory mediator plays an important role in the change of permeability of BBB. It's a critical inducing factor in the change of permeability of BBB under high altitude exposure.</p>

The role of hypoxic response and breath holding at sea level in prediction of acute mountain sickness / 中国应用生理学杂志

<p><b>AIM</b>To explore whether hypoxic response and breath holding at sea level could predict acute mountain sickness (AMS).</p><p><b>METHODS</b>113 men aged (19 +/- 1) years took part in this study. Blood oxygen saturation (SaO2), heart rate and blood pressure were measured during the course of breathing 10% O2 for 10 minutes and breath holding. Two days later after reaching Lasa (3 658 m altitude) by air, the symptomatic scores of AMS were evaluated. Then the relations between them were analyzed.</p><p><b>RESULTS</b>The SaO2 reduced progressively and the heart rate speeded up, while the blood pressure represented increase at first and then decrease within 10 min during the short-term hypoxia. The heart rate was lower during short-term hypoxia in subjects who developed AMS than in subjects doing well. But significant reverse correlation existed only between AMS scores and heart rate at 7th min after hypoxic breathing (r = -0.176).</p><p><b>CONCLUSION</b>Limited information can be gained on AMS score by assessing physiological responses to short-term hypoxia and breath holding at sea level.</p>