Changes in the serum LDH isoenzymes in monkey during chronic exposure to simulated high altitude

When the monkey was exposed to a simulated high altitude of 18,000 ft (5,486 m) for 30 d, the serum LDH activity was increased to its maximum in 1 week. After the monkey returned to sea level, the enzyme activity showed a rapid recovery. On the basis of electrophoretic analysis of LDH isoenzymes, the percentages of LDH-1 and LDH-2 were decreased during the first 2-3 weeks of hypoxic exposure whereas those of LDH-3, LDH-4 and LDH-5 were increased. After 2 or 3 weeks of hypoxic exposure, LDH-3, LDH-4, and LDH-5 become predominant, indicating that the isoenzyme pattern shifted to an anaerobic form from an aerobic form. These results clearly showed that relative proportions of the five isoenzymes were significantly altered by chronic hypoxia of high altitude and that the elevation of total serum LDH activity induced by hypoxia came predominantly from rapid accumulation of M type LDH isoenzymes in serum.     

高原地区慢性阻塞性肺疾病与支气管哮喘患者气道阻塞可逆性对比研究

目的:探讨高原地区慢性阻塞性肺疾病(COPD)患者气道阻塞的可逆性,并与哮喘患者对比。方法:用SpirolabⅡ全自动肺功能仪测定COPD和哮喘患者吸入盐酸特布他林气雾剂前后肺通气功能,并进行了比较。结果:①COPD组和哮喘组的基础肺通气功能无显著差异性(P>0.05);②吸药后,两组患者的肺通气功能各项指标均明显改善(P<0.01),但COPD患者的改变率显著小于哮喘组(P<0.01);COPD单纯型组各项指标均有显著改善(P均<0.05),但改善率显著小于喘息型组(P<0.01),喘息型组改善率仍显著小于哮喘组(P均<0.01);③COPD患者中有15.2%支气管舒张试验阳性,哮喘患者中93.3%支气管舒张试验阳性。结论:COPD患者气道阻塞具有一定可逆性,但可逆性程度明显低于哮喘患者。β2-受体激动剂对高原COPD患者有明显的治疗作用。     

慢性阻塞性肺疾病合并肺动脉高压炎性介质研究

目的探讨高迁移率族蛋白B1(HMGB1)、肿瘤坏死因子α(TNF-a)及白介素6(IL-6)血清表达水平与慢性阻塞性疾病(COPD)及COPD所致的肺动脉高压的相关性。方法选取自2015年1月至2016年5月收治的COPD患者96例为研究对象,根据患者患病情况将其分为单纯COPD组(A组,n=56)及COPD合并肺动脉高压组(B组,n=40)。另选取20例健康研究对象作为健康组。采用第1秒用力呼气容积(FEV1)占预计值百分比(FEV1%)、FEV1/用力肺活量百分比(FEV1/FVC%)评价各组研究对象的肺功能;用超声心动图测定肺动脉压力;采用酶联免疫吸附试验检测各组研究对象血清HMGB1、TNF-a、IL-6水平并进行比较,分析血清HMGB1、TNF-a、IL-6水平与肺功能、肺动脉压力的相关性。结果 B组肺动脉压明显高于A组和健康组,组间比较,差异均有统计学意义(P <0. 05); B组的FEV1%及FEV1/FVC%均低于A组和健康组,且A组低于健康组,组间比较,差异均有统计学意义(P <0. 05)。B组的HMGB1、TNF-a及IL-6均高于A组、健康组,且A组上述指标均高于健康组,组间比较,差异均有统计学意义(P <0. 05)。相关性分析结果显示,HMGB1、TNF-a、IL-6与肺动脉压呈正相关,与FEVI%、FEV1/FVC%呈负相关。HMGB1与TNF-a、IL-6呈正相关。结论 HMGB1、TNF-a、IL-6介导了COPD全身炎症反应,这些细胞因子在COPD、肺动脉高压的发生、发展过程起重要作用。     

Imaging phenotypes of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of morbidity and mortality worldwide. COPD is defined by irreversible airflow obstruction. It is a heterogeneous disease affecting the airways and/or the parenchyma with different severity during the course of the disease. These different aspects of COPD can be addressed by imaging using a combination of morphological and functional techniques. Computed tomography (CT) is the technique of choice for morphological imaging of the lung parenchyma and airways. This morphological information is to be accomplished by functional information about ventilation and perfusion, mainly provided by magnetic resonance imaging (MRI). The comprehensive diagnostic possibilities of CT complemented by MRI will allow for a more sensitive detection, phenotype-driven characterization, and dedicated therapy monitoring of the disease.     

慢性阻塞性肺疾病的早期诊断

慢性阻塞性肺疾病（chronic obstructive pulmonary disease,COPD）是一种严重影响人类健康的疾病,且其发病率逐年上升,而COPD的早期诊断可能对于防止疾病进一步恶化及随后众多并发症的出现具有重要意义。因此,为探讨COPD早期诊断的方法及其意义,作者综合分析近几年关于COPD早期诊断的国内外文献,为日后人们认识、诊断和治疗COPD提供新思路。     

New modalities of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Pulmonary rehabilitation has been shown to be an important part of the management of patients with chronic obstructive pulmonary disease (COPD). Exercise training is the corner stone of a comprehensive, multidisciplinary pulmonary rehabilitation in COPD and has been shown to improve health-related quality of life and exercise capacity. Nevertheless, not every COPD patient responds well to pulmonary rehabilitation.Future trials should focus on new additions to conventional pulmonary rehabilitation programmes to optimise its effects on health-related quality of life, exercise capacity, body composition and muscle function in patients with COPD. Therefore, a patient-tailored approach is inevitable. Advantages and disadvantages of new modalities of pulmonary rehabilitation will be outlined in detail, including the following: endurance training and long-acting bronchodilatators; endurance training and technical modalities (inspiratory pressure support and inspiratory muscle training); interval training; resistance training; transcutaneous neuromuscular electrical stimulation; and exercise training and supplements (oxygen, oral creatine, anabolic steroids and polyunsaturated fatty acids).Based on well defined baseline characteristics, patients should most probably be individually selected. At present, these new modalities of pulmonary rehabilitation have been shown to improve body composition, skeletal muscle function and sometimes also exercise capacity. However, the translation to an improved health-related quality of life is mostly lacking, and cost effectiveness and long-term effects have not been studied. Moreover, future trials should study the effects of pulmonary rehabilitation in elderly patients with restrictive pulmonary diseases.     

Visual fields during acute exposure to a simulated altitude of 7620 m

BACKGROUND: The hypoxia associated with sudden exposure to high altitude is known to impair vision and may thereby affect flight safety. However, no data were available regarding hypoxic effects on visual fields. The aim of this study was to evaluate black-and-white visual field sensitivity with acute hypoxia during acute exposure to a simulated altitude of 7620 m. METHODS: Subjects were 15 male pilots 26-39 yr of age. We measured arterial oxygen saturation (S(aO2)%) using transdermal pulse oximetry while the visual field was measured within a 30 degrees eccentricity in the right eye by computerized perimetry. The subject breathed 100% O2 for 30 min before and during chamber ascent, then removed his mask while measurements were performed. RESULTS: The S(aO2)% and visual field sensitivities (mean +/- SD) at ground level were 99.1 +/- 0.4% and 43.9 +/- 2.1 dB, respectively. During hypoxia, the S(aO2)% dropped to 64.0 +/- 5.4% within 3 min. Mean visual sensitivity was significantly reduced by 7.2 +/- 1.6 dB. Furthermore, peripheral sensitivity was slightly but significantly more diminished than central sensitivity. CONCLUSIONS: Severe acute hypoxia reduces central and moderate peripheral black-and-white vision by a factor of two with the strongest effect in the periphery.     

Ethanol-induced lowering of arterial oxyhemoglobin saturation during hypoxia.

Nine fasting, healthy, adult male volunteers were given oral carbohydrate before exposures to normoxia (PIO2 = 149 torr) and mild hypoxia (PIO2 = 98 torr). Following recovery, they were given oral ethanol before similar exposure to normoxia and mild hypoxia. Repeated measures of arterial blood and expired gases were made. Ethanol diminished respiratory gas exchange (R), causing lower alveolar and arterial oxygen pressures during normoxia and mild hypoxia and a reduction in arterial oxygen saturation from 89.9 to 87.4% during mild hypoxia. It is suggested that carbohydrates are preferable to ethanol and fats as nutrients during limited oxygen transport situations, such as high-altitude, carbon monoxide exposure, or during heavy exertion, and for patients with cardiovascular or pulmonary disease.     

Athletic training in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common and very debilitating disease in the United States. COPD is characterized by plugging of airways with secretions, impaired airway integrity with airway collapse with effort, bronchospasm, frequent infections, destruction of alveolar tissue, and ventilation-to-perfusion inequality. This results in abnormalities in pulmonary mechanics and respiratory gas exchange, all of which make hyperventilation much less effective. However, research has shown that the pulmonary patient can improve work capacity in an exercise training program. Training also alleviates the severe emotional problems of anxiety, depression, and social isolation frequently present in COPD sufferers. Even the lowest level patient can frequently improve in a training program, and guidelines for the implementation of such a therapeutic regimen are provided.     

Balance is impaired in people with chronic obstructive pulmonary disease

BackgroundIt has recently been suggested that people with chronic obstructive pulmonary disease have an increased risk of falls. Although falls risk is multifactorial, impaired balance may contribute. The primary aim of this study was to compare balance between people with and without chronic obstructive pulmonary disease and the secondary aim was to determine if balance deteriorates when respiratory demand is increased by upper limb exercise.MethodsTwelve people with chronic obstructive pulmonary disease and 12 healthy control subjects participated in this study. Participants stood on a force plate to record centre of pressure displacement during a range of conditions that challenge balance. Lumbar spine and hip motion were measured with inclinometers. Balance trials were performed before and after participation in upper limb exercise that increased respiratory demand in those with chronic obstructive pulmonary disease.FindingsPeople with chronic obstructive pulmonary disease had increased mediolateral centre of pressure displacement and increased angular motion of the hip compared to healthy controls. Mediolateral centre of pressure displacement was further increased in people with chronic obstructive pulmonary disease following exercise, but unchanged in controls. Anteroposterior centre of pressure displacement did not differ between groups.InterpretationPeople with chronic obstructive pulmonary disease have reduced control of balance in the mediolateral direction. This may contribute to an increased risk of falls in this population.     

Exercise training in patients with chronic obstructive pulmonary disease.

Most patients with chronic obstructive pulmonary disease (COPD) demonstrate positive responses to exercise conditioning. Dyspnea is reduced and work tolerance is extended with little or no change in pulmonary function noted. Possible explanations for the increased ability to better tolerate exercise and activities of daily living (ADL) after training include: 1) psychological encouragement, 2) improvements in mechanical efficiency, 3) improved cardiovascular conditioning, 4) improved muscle function, 5) biochemical adaptations responsible for reducing glucose utilization, 6) desensitization to dyspnea, and 7) contributions from better self-care. However, not all patients respond positively to exercise conditioning. This may represent differences in patient selection, training approaches, and/or comorbidity issues commonly seen in patients with COPD. Alternatively, the answer may reside in devising an optimal training intensity, duration, and frequency combination for patients with COPD. This is not an easy matter because of the diversity of patients categorized as COPD. We have reviewed these issues from the available data and presented areas where additional research is warranted. What is needed at present is a series of well-controlled studies that focus on identifying and improving training responses in patients with COPD. Secondary to this issue is the long term epidemiologic surveillance of trained patients to document sustained effects.     

MSCT在慢性阻塞性肺疾病研究中的应用

<正> 慢性阻塞性肺疾病(chronic obstructive pulmonarydiseases,COPD)是一类重要的呼吸系统疾病,是空气滞留于肺泡腔内,从而发生呼气性通气功能障碍和残气量增多,其特征性的病理学改变存在于中央气道、外周气道、肺实质和肺的血管系统,诊断和检测传统上多依赖于临床肺功能检查(PFT)。美国胸科协会(ATS)在2004年颁布的《慢性阻塞性肺疾病全球倡议》(global initiative for     

胃癌合并慢性阻塞性肺病的围手术期处理

目的：探讨胃癌合并慢性阻塞性肺病（COPD）的围手术期处理。方法：回顾性总结了35例胃癌合并COPD患者围手术期的处理。结果：35例患者中术后13例发生并发症（37．1％）,其中肺部并发症11例,占术后并发症的84．6％。肺部感染10例,其中肺部感染合并呼吸衰竭6例、肺不张2例、胸腔积液2例。死亡1例,为严重肺部感染并呼吸衰竭。结论：当胃癌患者合并COPD时,手术虽非禁忌,但属高危人群。应完善术前评估,加强围手术期的监测,即时处理肺部并发症。     

Alterations in human upper extremity motor function during acute exposure to simulated altitude

We tested the hypothesis that mild motor dysfunction was associated with Acute Mountain Sickness (AMS) by measuring arm movement characteristics in 14 subjects at sea level and at the end of a 30-h simulated altitude exposure (4,600 m). A computerized upper extremity movement analyzer (UEMA) was used to quantitate arm movements between a "start" position and randomly-generated targets on a large digitizing tablet by measuring selected speed parameters and error indices. The UEMA results were compared with the results of the Environmental Symptoms Questionnaire (ESQ) and with neurologic examinations. When compared with sea-level values, the mean values for all the speed-related parameters measured at the end of the 30-h exposure significantly declined by 20% to 32%. The error indices were not different. The declines in the speed-related parameters were significantly correlated with the severity of AMS symptoms as measured by the ESQ (R = 0.82). The neurologic abnormalities were limited to changes in mental status items. These results demonstrate that subclinical alterations in upper extremity speed are associated with mild, reversible AMS and provide evidence that hypoxia may produce supraspinal inhibition of motor pathways.     

Changes in glycolytic intermediates in rat erythrocytes during exposure to simulated high altitude

Regulatory mechanisms of erythrocyte glycolysis and 2,3-diphosphoglycerate (2,3DPG) metabolism under hypoxia were studied in rats exposed to a simulated altitude of 18,000 ft (5,486 m) for 5 d. Changes in erythrocyte glycolytic intermediates were determined by enzymatic analysis. Marked alterations of glycolytic intermediates were found during 1 d of exposure which were quite different from those observed during exposure for 2, 3, and 5 d. Alterations of intermediates seem to be highly correlated with blood pH changes; however, pH alone cannot explain the overall changes in intermediates. Results suggested that overall intermediate changes are the results of the combined effect of alterations of cellular pH and hemoglobin desaturation. Increased 2,3DPG at initial stages of exposure (within 1 d) may be caused mainly by the increased cellular pH; sustained elevation of 2,3DPG at later stages could be attributed to the relief of product inhibition of diphosphoglycerate mutase by deoxygenation.