Is Tourette syndrome a cause of sudden infant death syndrome and childhood obstructive sleep apnea?

The cause of sudden infant death syndrome (SIDS) is unknown. Sleep-related impairment of respiratory control and arousal are postulated; hyperdopaminergic and hyposerotonergic dysfunction may contribute to events leading to infant apnea and SIDS. Psychosocial adversity and impulsive and compulsive behaviours characterize some families of SIDS victims. Tourette syndrome (TS) is a common hereditary neurobehavioral disorder characterized by the frequent presence of impulsive and compulsive behaviors. Sleep disorders are common and include sleep apnea and abnormal arousal. Hyperdopaminergic and hyposerotonergic abnormalities are postulated to contribute to the pathophyusiology of the disorder. The following is a report of the presence of incidents of infant apnea and SIDS in families in which TS was present. In an additional TS family, a child had obstructive sleep apnea syndrome (OSAS). Results of a preliminary survey suggest that TS gene carriers are at increased risk of life-threatening apneas of infancy and that the prevalence of SIDS in such families may be 2 to 5 times the prevalence in the general population. The presence in some pedigrees of sleep apnea in children and adults suggest that in some instances disorders of sleep-related ventilatory control and arousal occurring throughout the life-span share common pathophysiological mechanisms. © 1993 Wiley-Liss, Inc.     

Development and characterization of DNAzyme candidates demonstrating significant efficiency against human rhinoviruses

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Reproducibility of the parameters of the on-transient cardiopulmonary responses during moderate exercise in patients with chronic obstructive pulmonary disease

To be clinically useful as indices reflective of altered physiological function consequent to interventions in patients with chronic obstructive pulmonary disease (COPD), the time constant (τ) and steady-state amplitude of the kinetic responses for oxygen uptake ( ) carbon dioxide output ( ) ventilation ( ) and heart rate (HR) have to be appropriately differentiable and reproducible. We therefore assessed the reproducibility of τ and steady state amplitude values in 41 patients with severe COPD [mean (SD)] [forced expiratory volume in 1 s=41 (7)% predicted], aged 64 (5) years. Of the total, 6 of the patients (15%) did not produce breath-by-breath data of sufficient quality to warrant kinetic analysis. The remaining 35 patients completed two moderate-intensity 10 min square-wave exercise tests separated by 2 h, both before and after an endurance training programme. Tests were conducted on an electromagnetically-braked cycle ergometer at an exercise intensity corresponding to 80% of the estimated lactate threshold (θ_La) or 50% of peak oxygen uptake if θ_La was insufficiently differentiable. Breath-by-breath measurements of , , and HR were averaged into 10 s bins and the on-transient response kinetics were estimated using a mono-exponential model. Analysing the pre-training and the post-training test 1 and test 2 comparisons together, the test 1 –test 2 differences were not significantly different from 0 for either τ or A. The standard deviation of the test 1 –test 2 differences allowed us to define the magnitude of change that would reach statistical significance. For τ, this averaged some 8, 10, 11 and 8 s, for , , and HR, respectively, for a one-tailed paired-comparisons test (i.e. appropriate for assessing hypothesised improvements resulting from an intervention); for a two-tailed comparison, the differences were approximately 2 s greater. The corresponding one-tailed values for A were 100 ml·min^–1, 95 ml·min^–1, 2.5 1·min^–1 and 4 beats·min^–1, respectively; the two-tailed values were 10%–15% greater. We therefore conclude that both τ and A for moderate-intensity exercise can be reproducibly estimated in patients with COPD when the data set provides a sufficiently large amplitude of response and sufficiently low sample variability to allow appropriate parameter estimation. Electronic Publication     

脉络宁对COPD患者ET含量的变化观察

目的:探讨脉络宁对慢性阻塞性肺病(chronic obstructive pulmonary diseases, COPD)患者血浆内皮素(endothelin, ET)含量变化的影响.方法:选择COPD患者45例在脉络宁应用前及一年时分别测定血浆ET含量为观察组;同期未应用脉络宁的COPD患者为对照组,同时测定ET含量.采用放免法(RIA)测定血浆ET含量.结果:观察组由治疗前(80.49±29.67)pg/ml至一年时(64.38±24.5)pg/ml;对照组(78.28±24.38)pg/ml至一年时(77.49±30.63)pg/ml.二组治疗前对比无差异(P＞0.05).应用后,一年时对比有显著性差异(P＜0.05).结论:脉络宁对COPD患者具有调节血浆ET使其减少的作用.     

经皮腔内室间隔心肌消融术对心电指标的影响

目的研究肥厚梗阻型心肌病患者经皮腔内室间隔心肌消融术对心电指标的影响。方法对50例肥厚梗阻型心肌病患者行经皮腔内室间隔心肌消融术,记录术前、术中和术后出现的心律失常类型,配对分析术前、术后心电指标的变化。结果术后与术前相比,QRS时限[(122.0±24.0)ms对(97.3±15.5)ms,P=0.000]明显延长,QTc[(469.3±32.2)ms对(434.3±41.5)ms,P=0.004]、PR间期[(169±26)ms对(162±24)ms,P=0.044]稍延长。术中心律失常发生率分别为:右束支传导阻滞70%(35/50),左束支传导阻滞8%(4/50),一过性AVB38%(19/50),频发室性早搏24%(12/50),短阵室性心动过速24%(12/50);未发生持续性室性心动过速和室颤。术后心律失常发生率分别为:右束支传导阻滞56%(28/50),左束支传导阻滞8%(4/50),交界区性心动过速4%(2/50),频发室性早搏16%(8/50),短阵室性心动过速8%(4/50)。无永久性起搏器植入及死亡病例。结论经皮腔内室间隔心肌消融术致心律失常的发生率高,右束支传导阻滞最为常见。严格选择适应证后谨慎地行PTSMA术是安全、可行的。     

Daytime variation in performance and tiredness/sleepiness ratings in patients with insomnia, narcolepsy, sleep apnea and normal controls

Daytime tiredness or sleepiness and deficits in cognitive performance are common complaints in sleep disordered patients. Till now there are few studies comparing patients from different diagnostic groups of sleep disorders in the same experimental protocol. We studied the time course of cognitive functions and subjective alertness in a parallel group design with four groups of patients [narcolepsy, untreated or treated obstructive sleep apnea (OSA), or psychophysiological insomnia] and a control group of subjects without sleep complaints. Each group consisted of 10 subjects, matched for age and gender. After a night with polysomnography, subjects were studied for 10 h from 08:00 hours to 18:00 hours at 20 min intervals under standardized environmental conditions. Four psychological tests were applied, (1) a critical flicker fusion (CFF) test to measure optical fusion threshold (alertness); (2) a paper-and-pencil visual line tracking test (selective attention); (3) a visual analog scale (VAS) for tiredness/sleepiness; and (4) the Tiredness Symptoms Scale (TSS), a 14 items check list. Each test session lasted for 8 min, followed by a 12 min pause. The level and time course of cognitive performance and self-rating data were analysed with hierarchical linear mixed effects models. Cognitive tests showed decrements in alertness and selective attention in untreated patients with insomnia, narcolepsy, and sleep apnea. Narcoleptic patients and untreated OSA had a lower CFF threshold than controls, and for narcoleptic patients the time course differed from that of all other groups. In the visual tracking test the performance of all groups of patients was worse compared with normal controls. Self-rated tiredness/sleepiness was significantly more pronounced in the three groups of untreated patients than in control subjects.     

正常成人上呼吸道CT测量及其意义

目的：确定正常人的上呼吸道CT扫描下各平面的横截面积、经线长度以及咽壁厚度，为临床服务。方法：无明显睡眠呼吸疾病史的成年人（男115、女110），采用Philips Tomoscan AV Expander E1螺旋CT，对鼻咽顶部到声门之间的区域进行连续扫描，测量软腭后区、悬雍垂后区、舌后区和会厌后区的气道横截面积、失状径、冠状径、咽侧壁和咽后壁软组织厚度，以单侧95％可信区间确定各测量指标的参考值。结果：在上呼吸道各个扫描平面，绝大多数气道的形状均为横椭圆形，冠状径大于失状径，在软腭后区、悬雍垂后区、舌后区和会厌后区中，失状径大于冠状径者分别占总人数的3．11％、10．67％、0．8％和0％。各年龄组间比较，绝大多数测量指标差异不显著，男子组和女子组间比较，除软腭后区外，大多数测量指标差异显著。故分别制定了男、女各测量指标的还范围。结论：成人上呼吸道CT测量以及正常范围的确定为临床判定OSAS患者上呼吸道解剖性狭窄的部位提供了客观依据，男性OSAS发病率明显高于女性有其相关的生理基础。     

Blood pressure analysis

SUMMARY  Arterial blood pressure is influenced by sleep-related breathing disorders. As cardiovascular consequences can be diagnosed by an accurate recording and analysis of blood pressure, new recording methodologies and an approach to analysis are presented here. Invasive continuous blood pressure recording is the common reference for all methodologies. As blood pressure varies rapidly in parallel with sleep-related breathing disorders it is indispensible to record blood pressure continuously. To introduce non-invasive methodology the Finapres system was used during sleep studies; a validation study showed severe limitations. This study was followed by the validation of an improved system called Portapres, which is portable, has two finger cuffs and a hydrostatic height compensation.
Analysis of continuous blood pressure in patients with sleep apnoea is carried out to detect mechanisms which influence the cardiovascular risk. Spectrum analysis of systolic blood pressure showed two different major oscillations present in patients with obstructive sleep apnoea. One oscillation (<0.06 Hz) occurs in parallel with each apnoeic episode and the other oscillation (0.2-0.4 Hz) occurs in parallel with the obstructive efforts during each apnoea and in parallel with respiration during periods of snoring. These two oscillations were so specific that the use of non-invasive continuous blood pressure recording allowed an estimation of the extent of underlying breathing disorders, and assessment of cardiovascular risk in a patient with obstructive apnoea in terms of hypertension and on the basis of ambulatory monitoring.     

Evaluation of quantitative aerosol techniques for use in bronchoprovocation studies

To investigate airway physiology by use of inhaled aerosols, it is frequently necessary to measure the actual amount of material deposited on the airway wall as well as the site of particle deposition. To satisfy these needs, radiolabeled aerosols and gamma camera techniques have been used to measure regional deposition of inhaled particles. To make quantitative measurements of the amount deposited, previous investigators have used a "phantom" technique to indirectly calibrate the gamma camera for the attenuation of gamma rays through the lungs and chest wall. For this calibration, the phantom is a simulated lung containing a known amount of radioactivity. Radioactive counts emitted from the phantom are assumed to be attenuated in the same manner as the intact human lung. The present article describes a technique to determine directly the amount of inhaled aerosol deposited in the lung and simultaneously to calibrate the gamma camera for each individual subject. We used right angle light scattering and a gamma camera to measure individual values of the deposition fraction (DF) of inhaled aerosol deposited in the lung and the coefficient of attenuation (AC) of gamma rays in normal and obstructed lungs of human subjects. Radiolabeled monodisperse aerosols 1 and 2 microns in diameter were used. Knowledge of the activity of the inhaled aerosol (microcurie per liter), the volume inhaled, and the measured DF determined each subject's AC (counts per minute per microcurie). DF varied by an order of magnitude in normal (0.04 to 0.48) and obstructed (0.16 to 0.75) of subjects.(ABSTRACT TRUNCATED AT 250 WORDS)