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In COPD, functional status is improved by pulmonary rehabilitation (PR) but requires specific facilities. Tai Chi, which combines psychological treatment and physical exercise and requires no special equipment, is widely practiced in China and is becoming increasingly popular in the rest of the world. We hypothesized that Tai Chi is equivalent (ie, difference less than ±4 St. George’s Respiratory Questionnaire [SGRQ] points) to PR.

ABSTRACTThe mechanisms underlying the functional link between autophagy and plant innate immunity remain largely unknown. In this study, we investigated the autophagy-mediated plant defense responses against Verticillium dahliae(V. dahliae) infection by comparative proteomics and cellular analyses. An assessment of the autophagy activity and disease development showed that autophagic processes were tightly related to the tolerance of Arabidopsisplant to Verticillium wilt. An isobaric tags for relative and absolute quantification (iTRAQ)-based proteomics analysis was performed, and we identified a total of 780 differentially accumulated proteins (DAPs) between wild-type and mutant atg10-1 Arabidopsisplants upon V. dahliaeinfection, of which, 193 ATG8-family-interacting proteins were identified in silicoand their associations with autophagy were verified for several selected proteins. Three important aspects of autophagy-mediated defense against V. dahliaeinfection were revealed: 1) autophagy is required for the activation of upstream defense responses; 2) autophagy-mediated mitochondrial degradation (mitophagy) occurs and is an important player in the defense process; and 3) autophagy promotes the transdifferentiation of perivascular cells and the formation of xylem hyperplasia, which are crucial for protection against this vascular disease. Together, our results provide several novel insights for understanding the functional association between autophagy and plant immune responses.

BackgroundThe mechanisms underlying sleep-related hypoventilation in patients with coexisting COPD and obstructive sleep apnoea (OSA), an overlap syndrome, are incompletely understood. We compared neural respiratory drive expressed as diaphragm electromyogram (EMGdi) and ventilation during stage 2 sleep in patients with COPD alone and patients with overlap syndrome.MethodsEMGdiand airflow were recorded during full polysomnography in 14 healthy subjects, 14 patients with OSA and 39 consecutive patients with COPD. The ratio of tidal volume to EMGdiwas measured to indirectly assess upper airway resistance.ResultsThirty-five patients with COPD, 12 healthy subjects and 14 patients with OSA completed the study. Of 35 patients with COPD, 19 had COPD alone (FEV138.5%±16.3%) whereas 16 had an overlap syndrome (FEV147.5±16.2%, AHI 20.5±14.1 events/hour). Ventilation (VE) was lower during stage 2 sleep than wakefulness in both patients with COPD alone (8.6±2.0 to 6.5±1.5 L/min, p<0.001) and those with overlap syndrome (8.3±2.0 to 6.1±1.8 L/min). Neural respiratory drive from wakefulness to sleep decreased significantly for patients with COPD alone (29.5±13.3% to 23.0±8.9% of maximal, p<0.01) but it changed little in those with overlap syndrome. The ratio of tidal volume to EMGdiwas unchanged from wakefulness to sleep in patients with COPD alone and healthy subjects but was significantly reduced in patients with OSA or overlap syndrome (p<0.05).ConclusionsStage 2 sleep-related hypoventilation in COPD alone is due to reduction of neural respiratory drive, but in overlap syndrome it is due to increased upper airway resistance.

It has been hypothesized that arousals after apnea and hypopnea events in patients with obstructive sleep apnea are triggered when neural respiratory drive exceeds a certain level, but this hypothesis is based on esophageal pressure data, which are dependent on flow and lung volume. We aimed to determine whether a fixed threshold of respiratory drive is responsible for arousal at the termination of apnea and hypopnea using a flow independent technique (esophageal diaphragm electromyography, EMGdi) in patients with obstructive sleep apnea.

To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA).

Assessment of neural respiratory drive is useful for diagnosis and management of breathing difficulty. The diaphragm is the most important muscle of respiration, therefore its electrical activity during spontaneously breathing could be used to reflect neural respiratory drive. In this study a catheter which was composed of 10 electrodes and two balloons was developed and was used to assess neural respiratory drive during CO2 rebreathing in six healthy subjects. There was a good linear relationship between diaphragm EMG and end-tidal CO2 (r = 0.98±0.01) during CO2 rebreathing. Transdiaphragmatic pressure was also well correlated with end-tidal CO2 during CO2 rebreathing. We concluded that the combined catheter developed in this study can be used to assess neural respiratory drive.

Many studies have shown that sleepiness is a major cause of traffic accidents. Some occupations, such as airplane pilots and automobile drivers, are not suitable for patients with daytime sleepiness. Therefore, it is important to establish an objective assessment of datime sleepiness for screening commercial drivers or pilot and for diagnosis of obstructive sleep apnea. In this study we introduced a portable system and compared it with traditional polysomnography in evaluation of daytime sleepiness. Eight patients with OSA and eight normal subjects were studied. Sleep latency as judged by portable device was the same as that judged by conventional polysomnography and sleep latency measured from patients with OSA (18.12±9.14 minutes) was significantly shorter than that in normal subjects (> 40minutes) , p&lt;0.01. In conclusion, portable device is as useful as conventional polysomnography in assessment of daytime sleepiness.

It is unknown whether efficiency of neural drive as expressed by a ratio of ventilation to the diaphragm electromyogram (EMGdi) in patients with COPD differs from that of healthy subjects during exercise and whether maximal neural drive is exhibited at the point of exercise termination.

Distinguishing central sleep apnea from obstructive sleep apnea can be clinically important because different types of apnea may require different treatment approaches. Academically, this distinction is important for investigating the pathological mechanism of different types of sleep apnea. Conventional polysomnography with recording of chest and abdominal movement may overestimate the frequency of CSA, leading to inappropriate treatment of sleep-disordered breathing. We hypothesized that diaphragm electromyogram (EMGdi) could be a useful technique to assess neural respiratory drive and respiratory effort and, therefore, to distinguish accurately CSA from OSA.

Breathlessness is an important cause of exercise limitation and reduced quality of life for patients with chronic obstructive pulmonary disease (COPD). One of the challenges of breathlessness management in COPD is the lack of physiological markers that reliably correlate with patients' symptoms. The aim of this study was to test the hypothesis that neural respiratory drive (NRD), measured with diaphragm electromyogram (EMGdi) activity, is closely related to breathlessness in COPD. We also investigated whether neuroventilatory uncoupling, which is the dissociation of ventilation from NRD as a consequence of abnormal pulmonary mechanics, contributes to breathlessness intensity over an awareness of levels of NRD alone.