睡眠中发作症状的脑电图特征及其与睡眠分期的关系

目的探讨睡眠中发作症状的脑电图特征及其与睡眠分期的关系。方法统计分析2012年9月至2014年9月收治的86例睡眠中发作症状患者的临床资料。结果夜发性额叶癫痫患者的痫样波检出率57.1%(12/21)显著高于睡眠肌阵挛、夜惊症、梦游症、梦魇患者9.7%(3/31)、18.8%(3/16)、0、0(P0.05);86例患者中,NREMⅠ期、NREMⅡ期是睡眠肌阵挛集中发生的时期,NREMⅢ期、NREMⅣ期是夜惊症、梦游症集中发生的时期,REM期是梦魇集中发生的时期,NREMⅠ期、NREMⅡ期是夜发性额叶癫痫主要发生的时期,其次为NREMⅢ期、NREMⅣ期,最后为REM期。结论不同睡眠中发作症状的脑电图特征差异显著,和睡眠分期关系密切,临床可以依据脑电图特征对睡眠中发作症状患者的疾病类型进行诊断,从而为及时准确地治疗和改善患者预后提供良好的前提条件。     

Circadian rhythms, sleep, and metabolism

The discovery of the genetic basis for circadian rhythms has expanded our knowledge of the temporal organization of behavior and physiology. The observations that the circadian gene network is present in most living organisms from eubacteria to humans, that most cells and tissues express autonomous clocks, and that disruption of clock genes results in metabolic dysregulation have revealed interactions between metabolism and circadian rhythms at neural, molecular, and cellular levels. A major challenge remains in understanding the interplay between brain and peripheral clocks and in determining how these interactions promote energy homeostasis across the sleep-wake cycle. In this Review, we evaluate how investigation of molecular timing may create new opportunities to understand and develop therapies for obesity and diabetes.     

Radioimmunoassay for pancreatic polypeptide, and its age-related changes in concentration

Pancreatic polypeptide (PP), a recently discovered pancreatic hormone, is potentially a marker for endocrine tumors. Consequently, we devised a radioimmunoassay for it, using antisera (raised in rabbits) to bovine PP, 125I-labeled bovine PP (purified by anion-exchange chromatography), and human PP standards. Concentrations circulating in fasting, normal subjects were measured. Statistical analysis of the results revealed a skewed distribution. An age-related increase was also observed. Evaluating PP concentrations in sera from 23 patients with endocrine tumors, we found increased values in a few cases of Zollinger-Ellison syndrome, medullary carcinoma of the thyroid, carcinoid syndrome, and one tumor producing vasoactive intestinal polypeptide (VIPoma). In contrast, values from five insulinomas and one glucagonoma were within the normal reference interval. Thus, an increased value for PP in a fasting individual may suggest the diagnosis of an endocrine tumor but is not a diagnostic prerequisite.     

Gamma EEG dynamics in neocortex and hippocampus during human wakefulness and sleep

Little is known about the neurophysiological mechanisms underlying the human sleep-wake cycle. Using intracranial electrodes in humans, we investigated changes in topographic distribution of gamma power and local- and long-range gamma EEG coherence in neocortex and hippocampus during different cerebral states. We report significantly greater variability in gamma power across cortical regions during wakefulness than during either slow wave or rapid eye movement (REM) sleep. In addition, local (within cortical regions) and long-range (between cortical regions) gamma coherence was significantly higher during wakefulness than during sleep, and functional gamma-range coupling between the neocortex and hippocampus was seen during wakefulness, but not during sleep. These findings demonstrate a functional link between different stages of conscious awareness and the level of coupling of gamma-band oscillations in the human brain.     

Golgi pH, its regulation and roles in human disease

Most organelles within the exocytic and endocytic pathways typically acidify their interiors, a phenomenon that is known to be crucial for their optimal functioning in eukaryotic cells. This review highlights recent advances in our understanding of how Golgi acidity is maintained and regulated, and how its misregulation contributes to organelle dysfunction and disease. Both its biosynthetic products (glycans) and protein-sorting events are highly sensitive to changes in Golgi luminal pH and are affected in certain human disease states such as cancers and cutis laxa. Other potential disease states that are caused by, or are associated with, Golgi pH misregulation will also be discussed.     

Slow EEG rhythms and inter-hemispheric synchronization across sleep and wakefulness in the human hippocampus

Converging data that attribute a central role to sleep in memory consolidation have increased the interest to understand the characteristics of the hippocampal sleep and their relations with the processing of new information. Neural synchronization between different brain regions is thought to be implicated in long-term memory consolidation by facilitating neural communication and by promoting neural plasticity. However, the majority of studies have focused their interest on intra-hippocampal, rhinal-hippocampal or cortico-hippocampal synchronization, while inter-hemispheric synchronization has been so far neglected. To clarify the features of spontaneous human hippocampal activity and to investigate inter-hemispheric hippocampal synchronization across vigilance states, pre-sleep wakefulness and nighttime sleep were recorded from right and left homologous hippocampal loci using stereo-EEG techniques. Hence, quantitative and inter-hemispheric coherence analyses of hippocampal activity across sleep and waking states were carried out. The results showed the presence of delta activity in human hippocampal spontaneous EEG also during wakefulness. The activity in the delta range exhibited a peculiar bimodal distribution, namely a low frequency non-oscillatory activity (up to 2 Hz) synchronized between hemispheres mainly during wake and REM sleep, and a faster oscillatory rhythm (2-4 Hz). The latter was less synchronized between the hippocampi and seemed reminiscent of animal RSA (rhythmic slow activity). Notably, the low-delta activity showed high inter-hemispheric hippocampal coherence during REM sleep and, to a lesser extent, during wakefulness, paralleled by a (unexpected) decrease of coherence during NREM sleep. Therefore, low-delta hippocampal state-dependent synchronization starkly contrasts with neocortical behavior in the same frequency range. Further studies might shed light on the role of these low frequency rhythms in the encoding processes during wakefulness and in the consolidation processes during subsequent sleep.     

Circadian changes in plasma phosphate concentration, urinary phosphate excretion, and cellular phosphate shifts.

The concentration of phosphate (Pi) in plasma, Pi excretion, and the tubular threshold of Pi resorption (TmP/GFR) all increase throughout the day from about 1100 to 0300 h. For plasma [Pi], cosinor analysis yielded the following estimates of the parameters of this pattern (with 95% confidence limits): amplitude = 0.17 (0.07-0.26) mmol/L, phase = peak at 0201 (1127-0342) h, and MESOR = 1.14 (1.11-1.18) mmol/L. The increase in TmP/GFR reflects an underlying change in renal Pi handling, which is not attributable to changes in parathyrin concentrations. The changes in Pi excretion work both for and against the changes in plasma [Pi], at different times. The calculated net nonrenal flux of Pi into the extracellular fluid increases in the morning and remains high until 0300 h, and neither it nor Pi excretion nor plasma [Pi] shows any relation to meals. This illustrates the importance of transient net fluxes of Pi between intracellular and extracellular spaces in the control of hour-to-hour changes of plasma [Pi].     

Circadian rhythms and sleep patterns in urban Greek couples

A convenience sample of 14 adults (seven couples) who intentionally nap regularly was recruited to describe circadian rhythms and sleep patterns in a culture in which afternoon naps are routine. Participants wore a wrist actigraph for 48 hr during May to obtain two peaks and troughs of activity data. Peak activity, estimated by cosinor analysis (acrophase), occurred at 1542 hours for men and at 1600 hours for women. Compared to their male partners, women had a later acrophase and a significantly stronger 24-hr rhythm, despite similar nap and nighttime sleep schedules. Men had more awakenings during the night and slightly shorter naps than did women. For the 24-hr period, men averaged 6.8 +/- 1.0 hr of sleep and women averaged 7.4 +/- 1.1 hr. Results indicate that Greek adults delay sleep onset at night and awaken early in the morning. Among this small group, naps are an accepted cultural behavior.     

Nonlinear components of age-related change in sleep initiation

BACKGROUND: Although primary studies suggest that ability to initiate sleep declines as people age, no systematic literature review has addressed the age(s) at which adults experience the greatest change in their ability to initiate sleep. OBJECTIVE: To explore whether there are any points in time across the adult life span when the rate of change in ability to initiate sleep increases or decreases. METHODS: Mathematical modeling was used to generate data points from information about central tendency, variance, and correlations between age and time to sleep onset provided by seven research reports. The reports represent 258 subjects ages 17 to 91 years. Smoothing splines were used to identify inflection points suggestive of major changes in sleep initiation across the life span. RESULTS: Two mathematical models were generated. One model suggested that inflection points may exist around ages 30 and 50 years, respectively. With this model, the amount of time until sleep onset increased until the age of 30 years, but was unchanged from ages 30 to 50 years. Ability to initiate sleep appeared to decline steadily after the age of 50 years. The second model, with a p value of 0.05, lacked adequate power to identify a significant nonlinear trend. CONCLUSIONS: Decline in ability to initiate sleep may not occur at a steady rate over the adult life span. Further research is needed to pinpoint thresholds of change and possible gender differences in thresholds.     

Spontaneous EEG changes during tobacco abstinence and nicotine substitution in human volunteers

Electroencephalographic correlates of tobacco abstinence and nicotine substitution were measured in adult male cigarette smokers in residence on a research ward in two experiments. After ad libitum smoking, seven subjects were deprived of nicotine for 10 days and then resumed smoking. During tobacco abstinence, there were significant decreases in alpha frequency and beta frequency and increases in theta power. These effects were observed as early as 29 hr and in some instances persisted for 7 days. In the second experiment, a group of eight heavy smokers chewed 12 pieces of either placebo or nicotine-containing polacrilex gum (2 or 4 mg) per day while deprived of cigarettes. In the placebo condition, electroencephalographic signs were similar to those accompanying tobacco deprivation in the first experiment. Administration of nicotine polacrilex prevented the appearance of these tobacco withdrawal signs. This study provides new information on the time course of certain electrophysiologic components of the tobacco withdrawal syndrome and confirms that the effects are specific to the deprivation of nicotine. The data also suggest that the 4-mg polacrilex was more effective than the 2-mg dose when the results across all measures were considered.     

Circadian changes in urinary bicarbonate,nitric oxide metabolites and pH in female player during handball camp involved in an exercise,rest and sleep cycle

Bicarbonate and nitric oxide levels are important humoral factors in the blood and are affected by the human body's physical condition. There are few reports, however, on changes in blood bicarbonate and nitric oxide levels during exercise and rest. Since urinary bicarbonate and nitric oxide metabolites reflect the levels of bicarbonate and nitric oxide in the blood, we studied circadian changes in 6 female athletes by monitoring their urinary pH and their levels of urinary bicarbonate and nitric oxide metabolites. Measurements were taken during exercise, rest and sleep. Six female athletes participated in a 3-day team handball training camp where they followed a schedule of exercise, rest and sleep. Urinary samples were collected immediately before and after handball training, at bed-time and upon waking. The urinary pH and levels of urinary bicarbonate and nitric oxide metabolites, including nitrite and nitrate, were examined with a blood gas analyzer and a NOx analyzer. The samples collected after handball training, as compared to the samples taken before exercise, showed a decreased pH, a decrease in levels of bicarbonate and little change in NO metabolites. During rest, urinary bicarbonate, NO metabolites and pH increased markedly in all 6 subjects. The levels of urinary bicarbonate, NO metabolites and pH significantly decreased upon waking. This study took into account the subjects' various physiological conditions when considering the significance of their changes in urinary bicarbonate, NO metabolites and pH during the 3 day handball training program. There were significant circadian changes in the urinary pH, and in the levels of urinary bicarbonate and nitric oxide metabolites, in the athletes involved in the exercise, rest and sleep program at team handball camp.     

EEG microstates of wakefulness and NREM sleep

EEG-microstates exploit spatio-temporal EEG features to characterize the spontaneous EEG as a sequence of a finite number of quasi-stable scalp potential field maps. So far, EEG-microstates have been studied mainly in wakeful rest and are thought to correspond to functionally relevant brain-states. Four typical microstate maps have been identified and labeled arbitrarily with the letters A, B, C and D. We addressed the question whether EEG-microstate features are altered in different stages of NREM sleep compared to wakefulness. 32-channel EEG of 32 subjects in relaxed wakefulness and NREM sleep was analyzed using a clustering algorithm, identifying the most dominant amplitude topography maps typical of each vigilance state. Fitting back these maps into the sleep-scored EEG resulted in a temporal sequence of maps for each sleep stage. All 32 subjects reached sleep stage N2, 19 also N3, for at least 1 min and 45 s. As in wakeful rest we found four microstate maps to be optimal in all NREM sleep stages. The wake maps were highly similar to those described in the literature for wakefulness. The sleep stage specific map topographies of N1 and N3 sleep showed a variable but overall relatively high degree of spatial correlation to the wake maps (Mean: N1 92%; N3 87%). The N2 maps were the least similar to wake (mean: 83%). Mean duration, total time covered, global explained variance and transition probabilities per subject, map and sleep stage were very similar in wake and N1. In wake, N1 and N3, microstate map C was most dominant w.r.t. global explained variance and temporal presence (ratio total time), whereas in N2 microstate map B was most prominent. In N3, the mean duration of all microstate maps increased significantly, expressed also as an increase in transition probabilities of all maps to themselves in N3. This duration increase was partly--but not entirely--explained by the occurrence of slow waves in the EEG. The persistence of exactly four main microstate classes in all NREM sleep stages might speak in favor of an in principle maintained large scale spatial brain organization from wakeful rest to NREM sleep. In N1 and N3 sleep, despite spectral EEG differences, the microstate maps and characteristics were surprisingly close to wakefulness. This supports the notion that EEG microstates might reflect a large scale resting state network architecture similar to preserved fMRI resting state connectivity. We speculate that the incisive functional alterations which can be observed during the transition to deep sleep might be driven by changes in the level and timing of activity within this architecture.     

Diffusion based MR measurements correlates with age-related changes in human intervertebral disks

BackgroundUnderstanding the association between MR parameters and age related deterioration in human intervertebral disks forms an important step in the development of clinical diagnostic protocols for disk disease.MethodsTen unfixed thoracic and lumbar cadaver disk joints, age 37–81 years were imaged at 9.4 T using T2 relaxation (CPMG) and ADC (DWI spin echo) MR protocols. For each MR parameter, spatial maps were computed from the axial images, with the AF and NP segmented based on the T2 maps. Linear regression tested for the correlation between mean and variance (COV) of T2 and ADC with age in the disk, nucleus and annulus, and the effect of thoracic vs. lumbar spine on these correlations.FindingsIn the disk, age negatively correlated with mean ADC (P < 0.001) and positively with COV of ADC (P < 0.001) and T2 (P < 0.05). Age was negatively correlated with mean T2 (P < 0.01), mean ADC (P < 0.001) and positively with COV of ADC (P < 0.001) and T2 (P < 0.05) in the NP and positively correlated with mean T2 (P < 0.05), COV of ADC (P < 0.01) and T2 (P < 0.05) and negatively with mean ADC (P < 0.05) in the AF. Compared to thoracic disks, lumbar disks showed higher mean ADC (P < 0.05), lower mean T2 (P < 0.001) and higher COV of ADC (P < 0.01) and T2 (P < 0.05).InterpretationCompared to T2, MR diffusion was a more sensitive measure of age mediated changes in disk tissues. Strong differences in the association of MR parameters with age between the lumbar and thoracic suggest that mechanical environment effects tissue specific MR parameters' association with age.     

睡眠影响记忆巩固功能的研究进展

睡眠对人类健康至关重要,研究发现其对记忆巩固具有重要的生物学作用。非快动眼睡眠促进与海马相关脑区的陈述性记忆的巩固有关,而快动眼睡眠与程序性记忆高度相关,且非快动眼睡眠与快动眼睡眠的协调对记忆巩固更为重要。慢性失眠患者容易出现记忆下降等认知功能改变。本文就睡眠影响记忆巩固功能的研究进展作一综述。     

Dehydration: biological considerations, age-related changes, and risk factors in older adults

Maintenance of water balance is essential to normal physiologic function and vigorous aging. Older adults, however, frequently experience alterations in fluid homeostasis, which result in dehydration. This article describes the physiology of water balance, age-related changes that influence fluid regulation, and associated risk factors for dehydration in older adults. Fluid hygiene is an important health promotion activity for this age group, but when efforts to prevent imbalance are unsuccessful, early identification and intervention to correct problems should be done to minimize adverse consequences. Although much is known about fluid homeostasis, dehydration, and contributory factors in the aging process, water disorders remain prevalent in this group. A great deal of work is still needed to determine "best practices" and creative clinical interventions to support adequate fluid intake behaviors. Both quality management programs and research studies provide avenues for systematic evaluation.     

Orexin, sleep and appetite regulation: a review

Since 1998, two research groups independently reported the discovery of two novel hypothalamic neuropeptides, called hypocretin-1 and hypocretin-2, respectively many studies have been carried out about their possible functions. One group named these new peptides orexins (A and B) after the Greek word for appetite, since they found that central administration of orexins potently increased food intake in rats. However hypocretins/ orexins are involved in various hypothalamic mechanisms, such as energy homeostasis, neuroendocrine functions, appetite and satiety regulation, vigilance and defence behaviour, sleep and wake regulation. Here is a review of the recent literature, showing some recent discoveries about the link between orexin system, sleep regulation and appetite regulation.     

择时治疗椎基底动脉短暂缺血性眩晕的疗效及对血脂的调节

背景:椎基底动脉短暂缺血性眩晕是脑卒中的预报信号,发病多与动脉粥样硬化有关,可以是脑梗死的前驱症状,任其自然发展约有1/3患者在以后数年内会发生脑梗死,尤其是在第1次短暂缺血发作后1～6个月是发病的高危时期,因此早期治疗甚为重要。目的:观察运用时间治疗学治疗椎基底动脉短暂缺血性眩晕的疗效及对血脂、脂蛋白、载脂蛋白的调节作用。设计:完全随机分组设计,对比观察。单位:青岛大学医学院中医教研室。方法:①选择2003-01/2004-06青岛大学医学院附属松山医院中医科住院椎基底动脉短暂缺血性眩晕患者66例,男47例,女19例。患者均对检测项目知情同意。随机分为2组:择时治疗组38例和不择时治疗组28例。②择时治疗组:选择每日辰时(7:00～9:00)应用足三里穴进行温针灸,每日针灸1次,每次每穴留针20min,配合中药葛根通络汤,1次/d,辰时一次性温服,10d为1个疗程。不择时治疗组:除辰时以外,随意选择时间治疗,其治疗方法与择时治疗组相同。治疗前后用酶法测血清总胆固醇、三酰甘油、载脂蛋白A1与载脂蛋白B100;用沉淀法测定高密度脂蛋白胆固醇,低密度脂蛋白胆固醇及极低密度脂蛋白胆固醇。3个疗程结束后评定疗效。③计数和计量资料差异比较采用χ2和t检验。主要观察指标:①两组治疗前后血脂变化。②两组治疗后疗效比较。结果:椎基底动脉短暂缺血性眩晕66例患者均进入结果分析。①3个疗程结束后,择时治疗组显著好转率明显高于非择时治疗组犤79%(30/38),43%(12/28),P<0.01犦。②择时治疗组治疗后总胆固醇、三酰甘油、低密度脂蛋白胆固醇、极低密度脂蛋白胆固醇、载脂蛋白B100水平明显低于治疗前和对照组治疗后(P<0.05～0.01),高密度脂蛋白胆固醇、载脂蛋白A1水平明显高于治疗前和对照组治疗后(P<0.05～0.01)。对照组治疗后总胆固醇、三酰甘油、低密度脂蛋白胆固醇、载脂蛋白B100明显低于治疗前(P<0.05～0.01),高密度脂蛋白胆固醇明显高于治疗前(P<0.01)。结论:选择适当的时间针灸并药物治疗椎基底动脉短暂性缺血性眩晕的疗效显著好于非择时治疗,且可更有效地降低血脂水平。