高原红细胞增多症患者血小板参数变化

目的:探讨拉萨地区高原红细胞增多症(HAPC)患者血小板参数变化.方法:采集63例高原红细胞增多症患者、42例高原正常居民、30例平原健康体检者静脉血(EDTA-K2抗凝血),美国雅培CELL-DYN200全自动血球分析仪分析标本.结果:与平原正常人相比较,高原正常居民及HAPC患者血小板计数(PLT)、血小板压积(PCT)均显著下降(P＜0.01),血小板平均体积(MPV),血小板分布宽度(PDW)显著升高(P＜0.01).HAPC患者与高原正常居民相比较,PLT、PCT进一步下降,两组间差异有显著性(P＜0.05);PDW、MPV则无差异性.结论:高原缺氧环境可致外周血液中血小板破坏增多,骨髓血小板代偿性增生、外周血血小板参数显著改变,但这种代偿功能有限,在HAPC患者表现尤为明显.     

西藏高原红细胞增多症发病率及其血红蛋白特异性研究

在西藏两个不同海拔高度地区世居和移居人群中进行高原红细胞增多症(HAPC)调查及对其血红蛋白(Hb)特异性进行研究。结果表明:(1)西藏拉萨地区人群中HAPC总发病率为2.39％,那曲-安多地区为12.95％,随海拔升高而发病率增多,汉族的发病率高于藏族,男性高于女性;(2)HAPC患者红细胞中MetHb为10.14％,显著高于高原健康人红细胞中的MetHb含量(6.35％),这可能是HAPC患者血液携带氧功能降低原因之一;(3)HAPC患者红细胞的穆斯堡尔谱除正常oxy-Hb和deoxy-Hb组分外,还发现存在第三组分“c”,这可能是血红蛋白的变性产物,是否与红细胞携带氧有关尚待研究。     

大豆异黄酮对海拔5000m以上高原红细胞增多症患者氧自由基代谢的影响

高原红细胞增多症(high altitude polycythemia,HAPC)是机体在高原缺氧环境中,红细胞过多增生使血液粘度增高、血流阻力增加而引起的一系列临床症状.海拔5000m以上人群的发病率明显增高.雌激素用于治疗HAPC已有多年的历史,与扩血管治疗合用可提高治疗效果[1].研究证实雌激素可抑制红细胞增生[2],因此高原红细胞增多症多见于成年男性、少见于女性.高原红细胞增多症的治疗一直是高原医学工作探索的难题.研究显示氧化应激是高原红细胞增多症等慢性高原病的重要发病因素之一[3].     

高原红细胞增多症中西医研究现状

高原红细胞增多症是(high altitude polycythemia, HAPC)是指长期居住在海拔2500m以上的居民,对高原低温、缺氧环境丧失习服所致的独特临床综合征。随着西部大开发及人文地理环境变化,高原红细胞增多症患者人群正日益扩大。目前高原红细胞增多症机制并未完全阐明,且缺乏规范化的治疗指南。本文拟通过文献研究总结HAPC中西医研究现状。     

高原红细胞增多症大鼠模型的sTfR和hepcidin表达

目的检测高原红细胞增多症动物模型的sTfR和hepcidin表达水平,探讨两者的关系及其在高原红细胞增多症发病机制中的作用。方法制备慢性高原病大鼠模型作为HAPC实验组,将西宁地区饲养的常氧大鼠模型作为对照组,测定大鼠血清铁调素(hepcidin)及肝脏铁调素、血清sTfR水平,及大鼠骨髓TfR及肝脏铁调素基因(HAMP)mRNA的表达。结果 HAPC组血清hepcidin、肝脏hepcidin水平明显低于对照组(P<0.01);HAPC组血清sTfR水平明显高于对照组(P<0.01);HAPC组大鼠肝脏HAMP mRNA表达明显低于对照组(P<0.05);HAPC组大鼠骨髓TfR mRNA表达明显高于对照组(P<0.01);HAPC组血清hepcidin、肝脏hepcidin分别与血清sTfR水平呈负相关性(r=-0.361,P=0.043,r=-0.575,P=0.001)。结论 sTfR可以作为HAPC红系生成的生物学标志之一;hepcidin水平在HAPC中明显降低,其结果促进机体肠道铁吸收并增加储存铁的动员,进一步促进红系生成;sTfR对HAMP表达有调节作用。     

高原红细胞增多症患者血小板参数变化

目的 :探讨拉萨地区高原红细胞增多症 (HAPC)患者血小板参数变化。方法 :采集 6 3例高原红细胞增多症患者、4 2例高原正常居民、30例平原健康体检者静脉血 (EDTA -K2 抗凝血 ) ,美国雅培CELL -DYN2 0 0全自动血球分析仪分析标本。结果 :与平原正常人相比较 ,高原正常居民及HAPC患者血小板计数 (PLT)、血小板压积(PCT)均显著下降 (P <0 .0 1 ) ,血小板平均体积 (MPV) ,血小板分布宽度 (PDW )显著升高 (P <0 .0 1 )。HAPC患者与高原正常居民相比较 ,PLT、PCT进一步下降 ,两组间差异有显著性 (P <0 .0 5 ) ;PDW、MPV则无差异性。结论 :高原缺氧环境可致外周血液中血小板破坏增多 ,骨髓血小板代偿性增生、外周血血小板参数显著改变 ,但这种代偿功能有限 ,在HAPC患者表现尤为明显     

移居汉族高原红细胞增多症多导睡眠监测

目的 研究高原红细胞增多症(High altitude poly cythemia,HAPC)夜间睡眠呼吸及血氧饱和度(arterial oxygen saturation,SaO2)特点,为临床合理治疗提供依据.方法 以40例患HAPC的汉族移居者为研究对象(HAPC组),并以20例健康的汉族移居者作为对照组.2组在安静、舒适的睡眠监测室内行整夜多导睡眠监测.观察呼吸暂停/低通气指数(apnea-hypopnea index,AHI)、呼吸暂停指数(apnea index,AI)、低通气指数(hypopnea index,HI)、清醒SaO2(awake SaO2,ASaO2)、睡眠平均SaO2(mean SaO2,MSaO2)、最低SaO2(lowest SaO2,LSaO2)、SaO2下降百分比(percentage of reduced SaO2,A-MSaO2％)、氧减饱和度指数(oxygen desaturation index,ODI4)、氧减时间百分比(percentage of time for ODI4,TODI4％)等指标.睡眠监测后填写匹兹堡睡眠质量问卷(pittsburgh sleep quality index,PSQI),并抽取静脉血检测红细胞(red blood cell,RBC)、血红蛋白(hemoglobin,HGB)、红细胞压积(haematocrit,HCT).结果 HAPC组RBC、HGB、HCT显著高于对照组(P＜0.01);2组PSQI总分及各因子计分无显著差异性(P＞0.05);2组AHI、AI无显著差异(P＞0.05),但HAPC组HI显著高于对照组(P ＜0.05);HAPC组ASaO2、MSaO2、LSaO2显著低于对照组,A-MSaO2％、ODI4、TODI4％显著高于对照组(P＜0.05).结论 HAPC患者夜间睡眠期间以低通气及SaO2水平显著降低为主要特征.     

青海高原某部战士与内地青年心电图的比较

目的 研究高原低氧对在海拔3000m生活2年的年轻人心电图的影响.方法 随机选取295例在海拔3000m平均生活2年的高原战士心电图(高原观察组)与520例体检合格准备入伍的内地青年心电图(平原对照组),就心率、PR、QRS、QT间期等参数及心电图异常情况进行对比分析.结果 高原地区人群心率减缓,PR间期、QRS间期和QT间期均数均高于平原地区人群,差异具有统计学意义(P均＜0.05);高原战士心电图总体异常率明显高于平原青年人群(54.9％ vs 14.8％,P＜0.01);但高原战士均无感觉不适或临床症状.结论 高原低氧对在其环境中生活数年的年轻人心电图有影响,可使其心率减缓,但不会对其身体造成病理性损害;平原年轻人对高原低氧环境适应力强.     

藏药复方新三果汤对高原红细胞增多症模型大鼠的影响

【目的】观察藏药复方新三果汤对高原红细胞增多症(HAPC)模型大鼠的影响。【方法】选用雄性SD大鼠40只,随机分为平原对照组、高原模型组、红景天组(剂量为3g·kg-1·d-1)、新三果汤高剂量组(剂量为2.5g·kg-1·d-1)、新三果汤低剂量组(剂量为1.25g·kg-1·d-1)。除平原对照组外,各组大鼠均置于5000m高原环境模拟舱中,缺氧40d(22h/d),复制红细胞增多症模型。于第41天观察各组对慢性缺氧诱导的HAPC模型大鼠血常规中红细胞(RBC)、血红蛋白(Hgb)、红细胞压积(HCT)以及血气分析各项指标、血清促红细胞生成素(EPO)等的影响。【结果】与平原对照组比较,高原模型组大鼠的RBC、Hgb和HCT显著增加(P0.001),pH值、PaO2、SaO2、PaCO2显著降低,血清EPO含量显著增加(P0.05或P0.001);与高原模型组比较,新三果汤高、低剂量组大鼠的RBC、Hgb和HCT均下降,pH值、PaO2、SaO2、PaCO2升高,且高剂量组作用较低剂量组明显,但仍高于平原对照组,并可降低缺氧大鼠血清EPO含量(P0.05或P0.01或P0.001)。【结论】藏药新三果汤对高原红细胞增多症有一定的防治作用。     

高原缺氧与细胞凋亡

高原缺氧引起血液学最主要的变化是红细胞增多，高原红细胞增多症(HAPC)红系增殖增强，为了研究增殖对立面细胞凋亡在HAPC中所起的作用，本文对高原缺氧状态下细胞凋亡变化进行综述。     

Determinants of acclimatisation in high altitude

Background: A total of 31 cases of effects of high altitude were admitted to a field hospital from a particular sector during the year 2008. This study was hence undertaken to see the efficacy of acclimatisation as well as outline the determinants of acclimatisation.     

Endothelial markers in high altitude induced systemic hypertension (HASH) at moderate high altitude

BackgroundChronic intermittent hypoxia is known to induce systemic arterial hypertension whereas chronic hypoxia causes pulmonary arterial hypertension. High altitude (HA) induced systemic hypertension (HASH) in previously normotensive lowlanders following acclimatisation and prolonged stay at moderate HA is a commonly encountered medical problem. HASH has been attributed to increased sympathetic discharge. Endothelial dysfunction (ED) is implicated in hypertension in the plains hence this study was conducted in HA. This is relevant especially because of the established role of ED in the aetiopathogenesis of HA illnesses. Since hypoxia may induce ED, we aimed at studying the association of endothelial dysfunction with HASH in temporary residents at HA.MethodsIn this case–control single-centre study, we evaluated ED, by measuring endothelial molecular markers, soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (VCAM-1), vascular endothelial growth factor (VEGF) and endothelial selectin (E-Selectin) in 24 cases with HASH and 25 age, sex matched normotensive controls at moderate high altitude (11,500 ft).ResultsThe levels of sICAM-1 (patients: 214.3 ± 34.2 μg/L, controls: 196.2 ± 28.5 μg/L; p = 0.049) and VCAM-1 (patients 766.1 ± 123.4 ng/mL, controls: 668.6 + 117.6 ng/mL; p = 0.007) were statistically higher in the patient group. However, VEGF and E-Selectin were not significantly different between the groups. sICAM-1 significantly correlated with levels of systolic and diastolic blood pressure (r = 0.401, p = 0.003 and 0.486, p = 0.000) respectively.ConclusionHASH is associated with endothelial dysfunction in form of raised levels of sICAM-1 and VCAM-1.     

Exercise and altitude.

In studies concerned with the performance at high altitude it is often not possible to separate the effects which are due to hypoxia from those associated with the stress of ascent. Some of the basic observations concerning exercise at high altitude are reviewed and a study is described which was designed to simulate the physical exertion of high altitude mountaineering but performed at altitudes below 1000 m. Some of the changes observed including peripheral oedema might under other circumstances have been ascribed to altitude.     

高原适应性的基因学研究进展

高海拔世居民能够很好的在缺氧、寒冷的环境下生存。从生理角度分析,高海拔世居民具有较低血红蛋白浓度、更高的一氧化氮水平等特点。近年来的研究显示这些适应性的改变是具备遗传学基础的,这些研究给我们提供了多个基因在高原人群中的特征,例如EPAS1、EGLN1、CBARA1,VAV3、PPARA、eNOS等,涉及缺氧诱导途径,缺氧诱导因子及其配体,红细胞的生产以及血管舒张性物质的产生。这些研究结果从遗传学角度给我们提供了新的线索,为我们揭示高原性自然环境选择的独特性、加深对高原疾病发生机制的理解、治疗和避免高原性疾病的发生提供了新的研究思路和策略。     

The influence of altitude in bronchial asthma

BACKGROUND: Some asthmatic children living in mountain areas experience significant improvement in daily symptoms and in the degree of bronchial obstruction. The aim of this study is to investigate the effect of altitude on the prevalence and morbidity of childhood bronchial asthma. METHODS: A questionnaire regarding the history and symptoms of asthma was distributed to 874 children aged 6-12 years, to be completed by their parents with the help of their pediatrician. A total of 583 children lived at sea level, 180 at an altitude between 501 and 800 meters, and 111 at an altitude between 801 and 1,200 meters. All children with recurrent cough, shortness of breath, wheezing, and a history of bronchial asthma were considered to have bronchial asthma. RESULTS: The prevalence of childhood bronchial asthma in the mountains (800-1,200 meters) was twice as low as that at sea level (15.8% of children) (p <0.01). Parental smoking was more frequent in children who lived at sea level than in the mountains. Additionally, consumption of fish and oranges was more frequent at sea level. Children with asthma who lived in the mountains were absent fewer days from school per year (0.2) and had fewer nights with dyspnea per year (0.5) than asthmatic children who lived at sea level (1.6 days and 25 nights, respectively). CONCLUSIONS: Bronchial asthma in children who live at high altitudes is characterized by low prevalence and low morbidity.     

Tear break-up time in high altitude areas

Background: In high altitude areas, patients report with irritation, redness and foreign body sensation in their eyes suggesting tear film abnormality due to low humidity and windy environmental conditions.