高原红细胞增多症患者夜间睡眠呼吸变化

高原睡眠结构紊乱和周期性呼吸已有较多记载,我们对海拔3730m处8例高原红细胞增多症(HAPC)患者在高原和平原夜间睡眠呼吸变化进行了研究,以探讨高原与平原对其夜间睡眠、呼吸和血氧饱和度(Sao_2)的影响。     

模拟高海拔低氧对人体睡眠的影响

在模拟不同海拔高度的低氧条件暴露下,我们记录和测定了6名对象的睡眠生理各项指标。结果如下:在急性低氧暴露下所有对象均出现了睡眠障碍,主要是在夜间规定睡眠时间中觉醒期和觉醒次数增加,深睡眠期和快眼动期减少,睡眠各期的呼吸频率和心率增加。随着低氧暴露时间的延长和多次空气潜水后,各睡眠生理指标有向海平对照值水平发展的趋势。4500m以上的低氧暴露下,所有对象在睡眠中都有周期性呼吸现象出现,并影响体内的缺氧。     

自由活动大鼠睡眠状态和呼吸节律的同步监测方法

目的:设计一种睡眠呼吸暂停综合征动物模型的监测方法.方法:通过多导生理仪同步监测自由活动大鼠6 h生理睡眠时间的皮层脑电、颈部肌电,以及呼吸波形.并用人机交互的方法进行数据处理.结果:监测信号稳定、清晰易辨,根据记录到的信号可进行不同清醒-睡眠状态分期,并判断大鼠的呼吸暂停情况.结论:该法操作简便,是小动物睡眠和呼吸监测的可靠方法.     

不同体位对严重肥胖者血氧饱和度的影响

目的:探讨不同体位对严重肥胖者血氧饱和度的影响。方法:16名平均体重指数(BMI)为40±5肥胖者和16名年龄匹配的正常体重者被纳入研究。分别在不同体外下(坐位、仰卧位、侧卧位)对所有参与者进行动脉血气监测。结果:肥胖者于坐位时动脉Pa O_2为75±4 mm Hg,Pa CO_2为37±3 mm Hg;仰卧位时动脉Pa O_2为62±5 mm Hg,Pa CO_2为47±5 mm Hg;侧卧位时Pa O_2为73±3 mm Hg,Pa CO_2为39±2 mm Hg;而正常体重者无明显变化。结论:严重肥胖者于平卧位时更容易出现低氧及高碳酸血症。     

精神疲劳状态下脑组织血氧饱和度的近红外光谱分析

目的:研究精神疲劳状态下脑组织血氧饱和度的变化规律。方法:从某军校随机抽取25名被试,采用模拟飞行任务负荷构建精神疲劳模型,采用NASA-TLX量表评价模型。实验全程使用近红外光谱技术对被试脑组织血氧饱和度进行实时监测;实验前后分别对被试的作业绩效水平进行评估。结果:任务后NASA-TLX量表评分明显高于任务前(P0.01);任务前后作业绩效发生变化,反应能力测试的正确率下降(P0.01),错误率上升(P0.01);任务负荷后脑组织血氧饱和度相对于静息状态升高(P0.05)。结论:精神疲劳状态会影响被试的作业绩效。疲劳后脑组织血氧饱和度水平受被试动机以及代偿机制的影响高于静息水平。     

急进高原健康人动脉血浆降钙素基因相关肽等物质含量的变化

目的：观测急进高原低氧环境,降钙素基因相关肽等6种血管活性多肽含量的动态变化,探索人体在急性缺氧时的生理调节过程。方法：用放射免疫法测定41名健康青年男性志愿者在海拔1100m世居地,进入海拔2260m3月、海拔3780m1d、5d和15d动脉血浆降钙素基因相关肽（CGRP）,内皮素（ET）等物质的含量。结果：动脉血浆舒血管物质CGRP、CNP、β-EP和NT浓度明显增加。而缩血管物质ET的含量在进入海拔3780m5d时显著下降（与海拔1100m、2260m和3780m1d相比差别显著,P〈0．01）,NPY含量不同海拔间无显著性差异。结论：动脉血中血管活性物质含量变化为血管舒张因子的含量显著增加,血管收缩因子含量明显下降,表明人体在急性缺氧时,血管扩张在肺循环对低氧的生理性调节中占主导地位。     

安静状态人对急性缺氧的呼吸反应

为研究急性缺氧时的呼吸反应类型,以17名健康男性青年为受试者,在低压舱模拟3000～7000m高度上进行了45人次缺氧暴露实验。在3000～5000m高度,肺通气量(V_E)增加主要取决于潮气量(V_T),呼吸频率(f)无明显变化。在5000m,4例出现周期性呼吸,1例发生通气抑制反应。在7000m,所见呼吸反应有三种类型:(1)f持续增加,V_T减小,此型受试者均有脑功能失调症状(5例),(2)V_T和f均增加(4例);(8)V_T增加,f相对稳定(2例),该型缺氧耐力较好。     

阻塞性睡眠呼吸暂停低通气综合征患者血脂水平的变化

探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)与血脂水平的关系。方法:选取32例OSAHS患者(OSAHS组)为试验组和30例健康体检者为对照组,均经多导睡眠监测仪(PSG)检查,测定空腹血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)的含量,比较两组间的差异。结果:OSAHS组空腹时TC、TG、LDL显著高于对照组,而HDL显著低于对照组。结论:OSAHS可引起脂质代谢异常,从而促进心血管疾病的发生。     

阻塞性睡眠呼吸暂停综合征的临床诊治新进展

阻塞性睡眠呼吸暂停综合征在目前耳鼻喉疾病中发病率日益增高,它以频繁发作的气道梗阻为主要特征,常常伴随着呼吸道气道管径减小,并使呼吸道更易发生进一步的狭窄和塌陷.急性和重复性呼吸暂停的副作用包括氧饱和度降低,胸内压减低,白天嗜睡,自主功能损伤和中枢神经系统损伤.呼吸暂停-减弱及呼吸窘迫检测指标有助于量化疾病的严重程度.呼吸暂停综合症有多种临床表现,其中以白天的嗜睡为主要症状.肥胖是重要发病因素之一.目前较为工人的呼吸暂停综合征包括阻塞性,中枢性和混合型三种,其中阻塞性最为常见.本综述主要从该病的X线表现,诊断和治疗这三个方面进行回顾.     

CIRCADIAN VARIABILITY OF BILIRUBIN IN HEALTHY MEN DURING NORMAL SLEEP AND AFTER AN ACUTE SHIFT OF SLEEP

Bilirubin is a laboratory test widely used for patient care, especially neonatal patients and patients with anemia or suspected liver disorders. Bilirubin has also been shown to be associated with sleep pattern and oxidative stress. The aim of this study was to investigate the variation of bilirubin in a group of healthy individuals with normal night sleep as well as during acutely displaced sleep, as sleep timing varies immensely between individuals while clinical samples are still mainly taken in the morning. We studied the diurnal variation of bilirubin during night-sleep and day-sleep conditions in seven healthy volunteers. Serum samples were collected every hour (50 samples/individual) to evaluate the effect of different sampling times and sleep displacement on the test results. The mean acrophases (peak time) occurred at 10.6?h during the night-sleep condition and at 18.4?h during the day-sleep condition. The diurnal intraindividual variation was high during both the night-sleep and day-sleep conditions, with coefficients of variation (CV) in the range of 12.8 to 42.5%. The diurnal variation was higher during the day compared to night-sleep condition. Thus, bilirubin sampling should be restricted to the morning, preferably after a normal night sleep, to minimize intraindividual variation. (Author correspondence: anders.larsson@akademiska.se)     

拉萨健康藏汉族青年运动时颈内动脉血流速度的变化

应用多普勒超声法测定了拉萨市１５名健康男性世居藏族和１１名健康男性移居汉族静息时的颈内动脉平均血流速度（ＩＣＡＭＦＶ）;以了解高原居民运动时ＩＣＡＭＦＶ、脑血流（ＣＢＦ）和脑氧供应量的状况。结果表明：静息时两组ＩＣＡＭＦＶ、ＣＢＦ及脑氧供应量相似;次极量运动时,两组的ＩＣＡＭＦＶ和脑氧供应量均增加;但在最大运动负荷时,仅世居组的ＩＣＡＭＦＶ及脑氧供应量增加。ＩＣＡＭＦＶ的增加可代偿最大运动时因ＳａＯ２降低所致的脑氧供应量下降。最大运动时世居组的脑氧供应量高于移居组,主要以ＣＢＦ增加同时与维持较高的ＳａＯ２有关。脑氧供应量的增加可能与提高最大运动负荷能力有关。结果说明长期居住于高原的世居人和移居人运动时ＣＢＦ反应己恢复到与平原相似的正常状态。     

CIRCADIAN VARIATION OF SERUM LEPTIN IN HEALTHY AND DIABETIC MEN

Leptin, from the Greek leptos, meaning thin (in reference to its ability to reduce body fat stores), is a hormone secreted primarily by adipocytes. At one time, leptin was portrayed as a potential means of combating obesity. Recently, leptin has been identified as a potent inhibitor of bone formation, acting through the central nervous system. Since numerous studies clearly show that bone remodeling is circadian rhythmic with peak activity during sleep, it is of interest to explore circadian variability in serum leptin. Accordingly, circadian characteristics of serum leptin were examined in 7 clinically healthy men and 4 obese men with type II diabetes. Blood samples were collected for 24h at 3h intervals beginning at 19:00. The dark (sleep) phase of the light-dark cycle extended from 22:30 to 06:30, with brief awakening for sampling at 01:00 and 04:00. Subjects consumed general hospital meals (2400 calories) at 16:30, 07:30, and 13:30. Serum leptin levels were determined by a R&D Systems enzyme immunoassay technique. Data were analyzed by linear least-squares estimation using the population multiple components method. A statistically significant (P <. 018) circadian rhythm modeled by a single 24h cosine curve characterized the data of each group. The 24h mean leptin level was statistically greater (P <. 001) in the obese diabetic men than in the healthy men (9.47 ± 0.66 ng/mL vs. 24.07 ± 1.71 ng/mL, respectively). Higher leptin levels occurred between midnight and roughly 02:30, and lowest leptin levels occurred between noon and the early afternoon. The phasing of this rhythm is similar to the circadian rhythm in bone remodeling previously described. Our results suggest the findings from a single morning blood sampling for leptin may be misleading since it may underestimate the mean 24h and peak concentrations of the hormone. (Chronobiology International, 18(2), 273–283, 2001)     

CONTRIBUTION OF CIRCADIAN PHYSIOLOGY AND SLEEP HOMEOSTASIS TO AGE-RELATED CHANGES IN HUMAN SLEEP

The circadian pacemaker and sleep homeostasis play pivotal roles in vigilance state control. It has been hypothesized that age-related changes in the human circadian pacemaker, as well as sleep homeostatic mechanisms, contribute to the hallmarks of age-related changes in sleep, that is, earlier wake time and reduced sleep consolidation. Assessments of circadian parameters in healthy young (～20–30 years old) and older people (～65–75 years old)—in the absence of the confounding effects of sleep, changes in posture, and light exposure—have demonstrated that an earlier wake time in older people is accompanied by about a 1h advance of the rhythms of core body temperature and melatonin. In addition, older people wake up at an earlier circadian phase of the body temperature and plasma melatonin rhythm. The amplitude of the endogenous circadian component of the core body temperature rhythm assessed during constant routine and forced desynchrony protocols is reduced by 20–30% in older people. Recent assessments of the intrinsic period of the human circadian pacemaker in the absence of the confounding effects of light revealed no age-related reduction of this parameter in both sighted and blind individuals. Wake maintenance and sleep initiation are not markedly affected by age except that sleep latencies are longer in older people when sleep initiation is attempted in the early morning. In contrast, major age-related reductions in the consolidation and duration of sleep occur at all circadian phases. Sleep of older people is particularly disrupted when scheduled on the rising limb of the temperature rhythm, indicating that the sleep of older people is more susceptible to arousal signals genernpated by the circadian pacemaker. Sleep-homeostatic mechanisms, as assayed by the sleep-deprivation–induced increase of EEG slow-wave activity (SWA), are operative in older people, although during both baseline sleep and recovery sleep SWA in older people remains at lower levels. The internal circadian phase advance of awakening, as well as the age-related reduction in sleep consolidation, appears related to an age-related reduction in the promotion of sleep by the circadian pacemaker during the biological night in combination with a reduced homeostatic pressure for sleep. Early morning light exposure associated with this advance of awakening in older people could reinforce the advanced circadian phase. Quantification of the interaction between sleep homeostasis and circadian rhythmicity contributes to understanding age-related changes in sleep timing and quality. (Chronobiology International, 17(3), 285–311, 2000)     

SLEEP IMPAIRMENTS IN HEALTHY SENIORS: ROLES OF STRESS,CORTISOL, AND INTERLEUKIN-1 BETA

Study Objectives: Increased stress responsivity and a longer-lasting glucocorticoid increase are common findings in aging studies. Increased cortisol levels at the circadian nadir also accompany aging. We used 24h free urine cortisol to assess these age changes in healthy seniors. We hypothesized that free cortisol levels would explain individual differences in age-related sleep impairments. Design: The study compared sleep, cortisol, and sleep-cortisol correlations under baseline and “stress” conditions in men and women. Setting: Subjects were studied in the General Clinical Research Center under baseline conditions and a mildly stressful procedure (24h indwelling intravenous catheter placement). Participants: Eighty-eight healthy, nonobese subjects (60 women and 28 men) from a large study of successful aging participated in the study. Mean ages were 70.6 (±6.2) and 72.3 (±5.7) years for women and men, respectively. Measurements: The 24h urines were collected for cortisol assay (radioimmunoassay [RIA]); blood was sampled at three diurnal time points for assay (enzyme-linked immunosorbent assay [ELISA]) of interleukin-1 (IL-1) beta; sleep architecture and sleep electroencephalograms (EEGs) were analyzed (after an adaptation and screening night) on baseline and stress nights via polysomnography and EEG power spectral analysis. Results: Healthy older women and men with higher levels of free cortisol (24h urine level) under a mild stress condition had impaired sleep (lower sleep efficiency; fewer minutes of stages 2, 3, and 4 sleep; more EEG beta activity during non–rapid eye movement sleep [NREM] sleep). Similar results were obtained when stress reactivity measures were used (cortisol and sleep values adjusted for baseline values), but not when baseline values alone were used. Gender differences were apparent: Men had higher levels of free urine cortisol in both baseline and mild stress conditions. Cortisol and sleep correlated most strongly in men; cortisol stress response levels explained 36% of the variance in NREM sleep stress responses. In women, but not men, higher cortisol was also associated with earlier time of arising and less REM sleep. Higher cortisol response to stress was associated with increased circulating levels of IL-1β, explaining 24% of the variance in a subset of women. Conclusion: These results indicate that free cortisol (as indexed by 24h urine values) can index responses to mild stress in healthy senior adults, revealing functional correlations (impaired sleep, earlier times of arising, more EEG beta activity during sleep, more IL-1β) and gender differences. (Chronobiology International, 17(3), 391–404, 2000)     

坐骨神经阻滞引起成年大鼠初级体感皮层代表区的快速改变

为了探讨成年大鼠坐骨神经（ＳＣＩ）去传入后初级体感皮层是否发生快速重组,在氯胺酮麻醉下,利用微电极测定后爪代表区,然后用普鲁卡因阻滞对侧ＳＣＩ。结果表明,阻滞后１ｈ、４ｈ和８ｈ,隐神经代表区（ＳＡＲ）比对照分别增大３２．５％（ｎ＝７）、９３．０％（ｎ＝１７）和１００％（ｎ＝４）。此外,在原ＳＡＲ和新生ＳＡＲ记录的平均多单位诱发反应的峰潜伏期,后者比前者延长４．３ｍｓ。作者推测在快速出现的皮层重组机制中,皮层－皮层多突触通路的去抑制可能起重要作用     

TEMPERATURE PROFILES,AND THE EFFECT OF SLEEP ON THEM,IN RELATION TO MORNINGNESS-EVENINGNESS IN HEALTHY FEMALE SUBJECTS

There were 15 healthy female subjects, differing in their position on the “morningness-eveningness” scale, studied for 7 consecutive days, first while living a sedentary lifestyle and sleeping between midnight and 08:00 and then while undergoing a “constant routine.” Rectal temperature was measured at regular intervals throughout this time, and the results were subjected to cosinor analysis both before and after “purification” for the effects of physical activity. Results showed that there was a phase difference in the circadian rhythm of core temperature that was associated with the morningness score, with calculations that “morning types” would be phased earlier than “evening types” by up to about 3h. This difference in phase (which was also statistically significant when the group was divided by a median split into a “morning group” and an “evening group”) could not be attributed to effects of waking activity and existed in spite of the subjects keeping the same sleep-wake schedule. Moreover, it persisted when the subjects' data had been purified and when the data were obtained from the constant routine. That is, there was an endogenous component to this difference in phase of the core temperature. The morning group also showed a greater fall of core temperature during sleep; this was assessed in two ways, the main one being a comparison of constant routine and nychthemeral data sets after correction for any effects of activity. Even though the morning group was sleeping at a later phase of their circadian temperature rhythm than was the evening group, neither group showed a fall of temperature due to sleep that varied with time elapsed since the temperature acrophase. It is concluded that another factor that differs between morning and evening types is responsible for this difference. (Chronobiology International, 18(2), 227–247, 2001)     

基底外侧杏仁核对大鼠睡眠和行为的调节作用及机制研究

目的和方法 :本研究运用多导睡眠描记 (PSG)方法、大白鼠开阔实验法及强迫游泳实验观察杏仁核的基底外侧核 (BLN)内微量注射谷氨酸、吗啡和纳络酮对大鼠睡眠、觉醒和行为的影响。结果 :用谷氨酸选择性兴奋BLN内神经元胞体可增加觉醒 ,减少慢波睡眠 (SWS)和总睡眠时间 (TST) ,增加大鼠自主活动和缩短强迫游泳“不动”时间。吗啡作用与谷氨酸相似 ,而阿片受体阻断剂纳络酮引起的作用则与之相反 ,并可完全阻断吗啡的作用。结论 :BLN神经元兴奋可引起觉醒增加、SWS减少和自主活动增加效应 ,阿片受体激动剂是BLN调节睡眠、觉醒和行为的重要递质。     

高原健康居民某些内分泌激素的变化及其生理意义

本文在海拔10m(青岛)、2260m(青海西宁)和3700m(青海玉树)三个高度,用放射免疫法,测定445例健康人血四碘甲腺原氨酸(T_4)、三碘甲腺原氨酸(T_3)、3,3’,5’三碘甲腺原氨酸(rT3)皮质醇(F)和醛固酮(ALD)含量。结果发现:(1)高海拔地区世居藏族与有15年以上移居史的汉族居民五项测值间无显著差别(P>0.05);(2)高海拔地区居民T_3、T_4、F和ALD含量降低(P<0.05～0.001),而rT3则升高(P<0.01)。这些变化的生理意义,可能反映了高原居民对低氧环境的一种慢性适应机制。在某些高原疾病防治中,适当应用肾上腺皮质激素,可能有一定临床价值。     

电刺激兔延髓腹侧化学敏感区和压力敏感区对呼吸、血压,的影响及其中枢递质机制

电刺激麻醉兔延髓腹侧化学敏感区头端区引起潮气量(V_T)增加,呼吸频率(f)增快;电刺激压力敏感区(中间区)则使V_T减小,f亦增快。弱刺激时,两者均产生降压反应;刺激增强可诱发双相或升压反应。在出现周期性呼吸时,电刺激化学敏感区可使呼吸节律正常化、V_T增大,而电刺激压力敏感区则导致呼吸暂停。电刺激压力敏感区时,吸气时间(TI)和呼气时间(T_E)均缩短,以T_E变化更明显;由于V_T减小和T_I缩短,V_T/T_I保持相对不变,提示吸气终止的中枢阈值降低。在准备刺激的相应局部预先应用阿托品,可使电刺激化学敏感区产生的通气增强效应翻转,而对电刺激压力敏感区引起的通气抑制无明显影响;用印防己毒素则可选择性消除电刺激压力敏感区的通气抑制和降压效应。本工作表明延髓腹侧存在两个不同的中枢机制,其中化学敏感区产生的通气增强与胆碱能系统有关;压力敏感区产生的通气减弱效应与GABA系统有关。