颅脑超声对高原新生儿缺氧缺血性脑病观察及探讨

本文对西宁地区新生儿缺氧缺血性脑病（ＨＩＥ）颅脑超声诊断分析脑缺氧缺血产生的原因、脑实质损伤程度及预后评估。提出对围产期窒息导致脑缺血性损害的预防措施。     

高原性蛋白尿与急性高原病关系的探讨

通过对34名平原人乘飞机进驻海拔4370m 高原后尿蛋白的动态分析和急性高原病(AMS)的调查,我们看到,受试者在达高原的1～3天内尿蛋白阳性率为20.6～26.5%,尿潜血反应阳性率为5.9～14.8%,4天后均接近平原值;AMS 者的尿蛋白浓度明显高于未患AMS 者(28.9±4.4v.s.17.1±2.2,p<0.05);在AMS 患者中,69.2%的人(9/13)尿蛋白阳性,30.8%的人(4/13)尿蛋白可疑,而且尿蛋白阳性者的AMS 症状持续的时间明显长于非尿蛋白阳性者(4.4±0.1v.s.3.6±0.1,p<0.05)。上述结果提示,平原人在快速进驻高原初期肾功能会受到严重影响,但经短期高原适应后是可以很快恢复的;AMS 与高原性蛋白尿有密切的关系;蛋白尿的产生可能是由肾小球基底膜受损后通透增加所致。     

The effect of drinking tea at high altitude on hydration status and mood

The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the tea condition, hot brewed tea formed a major part of fluid intake, whereas in the no-tea condition tea was excluded from the diet. Subjects were prohibited in both cases from consuming other caffeinated beverages, caffeinated foods, and alcoholic drinks. Mean fluids ingested [mean (SE); tea=3,193 (259) ml versus no tea=3,108 (269) ml] and urine volume (tea=2,686 (276) ml versus no tea=2,625 (342) ml] were similar under both conditions. Statistical analysis found no difference in urine stimulated as a result of the tea intervention (P=0.81). Several markers of hydration status were also taken immediately pre and post each condition, including measures of urine specific gravity, urine electrolyte balance (K⁺, Na⁺), and urine colour. None of these measures indicated a difference in hydration status as a result of the dietary intervention in either the control or tea condition. A difference was, however, found in mood, with subjects reporting reduced fatigue when tea was included in the diet (P=0.005). The study shows therefore that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood.     

Determinants of CD4 Counts Among HIV-Negative Ethiopians: Role of Body Mass Index,Gender, Cigarette Smoking,Khat (<Emphasis Type="Italic">Catha Edulis</Emphasis>) Chewing,and Possibly Altitude?

To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and -tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.     

Prevalence and severity of asthma and allergies in schoolchildren in Lhasa, Tibet

BACKGROUND: The International Study of Asthma and Allergies in Childhood (ISAAC) demonstrated that large variations existed in the prevalence of symptoms of asthma, allergic rhinoconjunctivitis and eczema throughout the world and that environmental factors and lifestyle customs are major determinants of the prevalence and severity of these diseases. However, the relevant data about children living at high-altitude locations were considered to be underreported. OBJECTIVE: The ISAAC Phase III programme was carried out in Lhasa, the Tibetan Autonomous Region in China, at an elevation of 3658 m above sea level to examine the occurrence of asthma, allergic rhinoconjunctivitis and eczema in schoolchildren aged 13-14 years. METHODS: All 3196 schoolchildren in eight public junior high schools in urban Lhasa who were confirmed to be 13-14 years old were invited and participated in both written and video questionnaire investigations, among which 3190 pieces of data (49.8% of boys and 50.2% of girls) were validated and analysed. RESULTS: Among the overall observations, the prevalence of 'having ever experienced wheezing', 'current wheezing' and 'diagnosed to have asthma' was 1.4%, 0.8% and 1.1%, respectively. The prevalence of current exercise-induced asthma and current nocturnal cough was 7.1% and 4.6%, respectively. The current prevalence of allergic rhinoconjunctivitis and eczema was 5.2% and 0.4%, respectively. In addition, the prevalence of rhinoconjunctivitis symptoms during the past 12 months showed no discernable differences throughout the year. CONCLUSION: The prevalence of asthma, allergic rhinoconjunctivitis and eczema over the past 12 months was the lowest among the centres, that performed ISAAC worldwide.     

Influence of hypobaric hypoxia in infancy on the subsequent development of vasoconstrictive pulmonary vascular disease in the Wistar albino rat

A group of Wistar albino rats was injected subcutaneously with monocrotaline to induce vasoconstrictive hypertensive pulmonary vascular disease characterized by medial hypertrophy of small pulmonary arteries, the appearance of muscular pulmonary arterial vessels of arteriolar dimensions (less than 20 microns) in diameter), and exudative changes in the lung parenchyma. The vascular abnormalities were quantified by measuring the percentage medial thickness of small pulmonary arteries, the number of muscular pulmonary arterial vessels below 20 microns in diameter per cm2 of lung section and by determining the smallest arterial vessels in each case showing muscularity. A second group of rats was born in a decompression chamber and kept in hypobaric hypoxia for a month of the neonatal period, developing hypoxic hypertensive pulmonary vascular disease as a consequence. The animals in this group were allowed to recover in room air for a period of 3 months and were then injected with the same dose of monocrotaline as that given to the first group. The rats previously exposed to hypoxia exhibited an exaggerated response to the alkaloid, showing in particular many more small muscular pulmonary arterial vessels which were of a smaller diameter than those found in the eupoxic rats treated with the alkaloid. The experiment demonstrates the perinatal hypoxia exaggerates the effects of agents inducing vasoconstrictive pulmonary hypertension with a shift of the segment of the pulmonary arterial tree involved to the periphery as in hypoxia. Reports of a similar phenomenon are noted as occurring in babies born at high altitude, spending their infancy there and subsequently developing primary pulmonary hypertension later in life.     

Severe gastritis in the Peruvian Andes

OBJECTIVE: To compare the Helicobacter pylori-associated pathology in gastric biopsies taken from patients living at sea level with those taken from patients living at high altitude. METHODS AND RESULTS: We included 38 patients from a hospital in the Andean city of La Oroya, Peru, located at 3700 m in altitude, and 40 control patients taken from Comas Clinic located in the city of Lima at sea level. Fibrepanendoscopy and multiple biopsies were performed in all the patients followed by histopathological examination. In the antrum, patients from the Andean town had a higher prevalence of glandular lymphoid adherence lesions, active germinal centres, moderate to severe chronic atrophic gastritis, intestinal metaplasia and moderate to severe total deep gland loss, than did patients from the coastal town. Furthermore, the severity of the histological lesions seen in the gastric body and cardia was significantly greater in the high-altitude patients than in those from sea level. CONCLUSION: This study suggests that the severity of H. pylori-associated gastric lesions seen on histopathological examination is greater in patients living at high altitude, the cause of which is most probably multifactorial but nonetheless principally altitude related.     

急性高原病患者支气管肺泡灌洗前后肺功能及血气的改变

目的:探讨急性高原反应(HAAR)及高原肺水肿(HAPE)的发病机理。方法:对10例HAAR患者及6例HAPE患者灌洗前和灌洗后进行肺功能和动脉血气检测, 并与10例高原健康者进行对比。结果:HAAR患者及HAPE患者灌洗前动脉血氧分压明显低于对照组, HAAR同HAPE均存在弥散功能障碍;HAPE肺弥散功能(DLCO%)由灌洗前的(76.01±6.29)%, 上升到灌洗后的(103.31±9.23)%;气体转化因子(DLCO/VA%)由灌洗前的(150.30±15.20)%, 上升到灌洗后的(176.04±16.10)%;动脉血氧分压(PaO₂)由(31.73±3.01)mmHg上升到(45.31±3.56)mmHg。而HAAR及对照组灌洗后上述指标差异不显著。结论:HAPE患者肺泡内大量的液体渗出是HAPE病情恶化的主要原因之一。HAAR属HAPE发展的初级阶段, 存在着间质性肺水肿。     

Effects of protein supplementation during prolonged exercise at moderate altitude on performance and plasma amino acid pattern

Summary The effects of two levels of protein intake on muscle performance and energy metabolism were studied in humans submitted to repeated daily sessions of prolonged exercise at moderate altitude. For this purpose, 29 healthy males, were exposed to seven successive stages of ski-mountaineering at altitudes between 2500 and 3 800 m, and to an isocaloric diet (4000 kcal·day^–1, 16760 kJ·day^–1) with either 1.5g·kg^–1·day^–1 (C group,n =14), or 2.5 g·kg^–1·day^–1 (PR group,n =15) protein intake. Measurements made after the ski-mountaineering programme did not show any change in body mass. The peak torque during maximal isometric voluntary contraction (MVC) of the quadriceps muscle was unaffected by the repeated exercises, whereas the endurance time at 50% MVC was decreased in PR subjects (–26.8%,P<0.001). Increased levels of both free fatty acids (+147%,P<0.001) and glycerol (+170%,P<0.001) observed in C subjects would suggest that lipolysis was enhanced after the repeated exercise. The plasma amino acid pattern was altered after completion of the ski-mountaineering programme; the plasma concentration of the three branched-chain amino acids (BCAA) was significantly decreased in C subjects, whereas the higher level of protein intake (PR group) greatly minimized the exercise-induced decrease in serum BCAA.     

急进高原人群脑血流量测定对急性高原病易感人群预测的临床与实验观察

本文对三级急进高原人群资料回顾分析了急进高海拔区（＞4500M）人群脑皿流量测定的临床意义。结果表明急进高原人群脑血流量较在低海拔区明显增高，有显著性差异；而急进高原人群中的急性高原反应和急性高原病患者脑血流量又显著高于高原适应人群。采用药物和吸氧治疗急进高原人群中急性高原反应人群，脑血流量明显降低，急进高原人群的高原反应程度和急性高原病的发病率亦相应降低。因此监测急进高原人群的脑血流量，不仅可以早期发现急性高原反应及急性高原病患者，更可以预测急性高原易感者，可为急性高原病的早期治疗和预防，扩大高原适应人群提供重要的理论依据。