Disease relevance of Respiratory Muscles

• METHODS: We sequenced SEPN1 in five unrelated CFTD patients with scoliosis and respiratory muscle weakness and screened an additional 22 CFTD patients for abnormalities in SEPN1 by Western blotting and restriction digest for the 943G-->A mutation [1].
• Near-infrared spectroscopy of an accessory respiratory muscle, Borg scale recordings of perceived dyspnea, time in inspiration, time per breath and minute ventilation were measured [2].
• In 12 patients with chronic obstructive pulmonary disease (COPD) receiving pressure support ventilation (PSV), we studied the variability of respiratory muscle unloading and defined its physiologic determinants using a modified pressure-time product (PTP) [3].
• If chronic hypercapnia in patients with severe COPD occurs as a consequence of respiratory muscle (RM) weakness or fatigue, we would expect that ventilatory muscle recruitment (VMR) and exercise performance in stable hypercapnic patients would differ from those in eucapnic patients [4].
• These data strongly suggest that theophylline, which increases respiratory muscle strength and delays the onset of diaphragmatic fatigue, could be a very useful agent in the treatment of patients with chronic airway obstruction [5].

Psychiatry related information on Respiratory Muscles

• Sleep deprivation and fragmentation occurring in the hospital setting may have a negative impact on the respiratory system by decreasing respiratory muscle function and ventilatory response to CO2 [6].
• The use of noninvasive respiratory muscle aids eliminates the need for "crisis" decision making about whether or not to "go on a respirator." Use of respiratory muscle aids by ALS patients familiarizes them with ventilator dependency before any decision about tracheostomy needs to be made [7].
• Short periods (< 20 s) of inhibition of phasic respiratory muscle activity during rapid-eye-movement sleep were followed by further decreases in arterial O2 saturation [8].
• Thus, at constant levels of arterial CO2 in anesthetized dogs, respiratory muscle partial paralysis results in a decrease in breathing rate without changing the rate of rise of respiratory motor activity [9].

High impact information on Respiratory Muscles

• The respiratory-muscle performance of the patients taking theophylline improved by approximately 29 percent (P less than 0.0001), as indicated by a decline in the ratio of inspiratory pleural pressure during quiet breathing to maximal pleural pressure [10].
• In conclusion, triamcinolone induced type IIb fiber atrophy, resulting in reduced respiratory muscle strength and a leftward shift of the force-frequency curve [11].
• We conclude that NPV as used in this study is difficult to apply and ineffective when used with the aim of resting the respiratory muscles in patients with stable COPD [12].
• CONCLUSIONS: Selective respiratory muscle training improves respiratory muscle endurance and strength, with an enhancement of submaximal and maximal exercise capacity in patients with heart failure [13].
• Elevated levels of lactate in brain, blood, and cerebrospinal fluid, abnormal urine organic acids, and changes in muscle respiratory chain enzymes are present but inconsistent, without identifiable mitochondrial DNA mutations or deletions [14].

Chemical compound and disease context of Respiratory Muscles

• In the absence of direct evidence, an O2 supply-demand imbalance within the diaphragm and other respiratory muscles in emphysema has been considered the most likely explanation for this failure [15].
• BACKGROUND: Changes in the distribution of respiratory drive to different respiratory muscles may contribute to respiratory depression produced by halothane [16].
• Polymyositis with respiratory muscle weakness requiring mechanical ventilation in a patient with metastatic thymoma treated with octreotide [17].
• We conclude that metabolic acidosis is a common finding in acute, severe asthma and suggest that the pathogenesis of lactic acidosis is multifactorial and includes contributions from lactate production by respiratory muscles, tissue hypoxia, and intracellular alkalosis [18].
• This reversible steroid-induced respiratory muscle weakness may be of great significance in reconsidering long-term steroid therapy in patients with underlying lung disease [19].

Biological context of Respiratory Muscles

• CONCLUSIONS: This study shows that oxidative stress rather than nitric oxide is likely to be involved in the respiratory muscle dysfunction in severe COPD [20].
• We addressed two questions concerned with the metabolic cost and performance of respiratory muscles in healthy young subjects during exercise: 1) does exercise hyperpnea ever attain a "critical useful level"? and 2) is the work of breathing (WV) at maximum O2 uptake (VO2max) fatiguing to the respiratory muscles [21]?
• We examined the effects of a supervised three-month running program on exercise tolerance, pulmonary function, cardiorespiratory fitness (peak oxygen consumption), and respiratory muscle endurance in CF patients [22].
• The reduced performance in CPX in our long-term survivors is caused by pulmonary perfusion abnormalities and low tidal volume, which is due to the deconditioning of respiratory muscle, rather than by interstitial changes or diffusion abnormalities [23].
• Further studies are needed to confirm the decreased respiratory muscle work of breathing during heliox inhalation in this population [24].

Anatomical context of Respiratory Muscles

• We tested the hypothesis that reflexes arising from working respiratory muscle can elicit increases in sympathetic vasoconstrictor outflow to limb skeletal muscle, in seven healthy human subjects at rest [25].
• Injection of bacterial lipopolysaccharides (LPS) in rats produced a significant rise in protein tyrosine nitration in the mitochondrial and membrane fractions but not in the cytosol of ventilatory muscles [26].
• To correct HVR for possible vecuronium-induced respiratory muscle weakness or otherwise altered central nervous system reactivity, the drug/control ratio (HVRb/a) was divided by the associated HCVRb/a ratio [27].
• The aim of this study was to determine the effects of halothane anesthesia on respiratory muscle activity and chest wall shape and motion during spontaneous breathing [28].
• BACKGROUND AND OBJECTIVES: Systemic lupus erythematosus (SLE) may affect all the components of the respiratory system, including upper airways, lung parenchyma, pulmonary vasculature, pleura, and respiratory muscles [29].

Associations of Respiratory Muscles with chemical compounds

• By analyzing the power spectrum and the amplitude behavior of the diaphragmatic EMG (calculated from the fc and RMS, respectively), we could exclude a disturbance of neural descending pathways and respiratory muscle dysfunction as possible causal mechanisms for the impaired ventilatory response to increasing CO2 [30].
• To manipulate O2 supply and O2 demand in locomotor and respiratory muscles, subjects performed both maximal conventional two-legged cycle ergometry (large muscle mass) and single-leg knee extensor exercise (KE, small muscle mass) while breathing room air (RA), 100% O2, and 79% helium + 21% O2 (HeO2) [31].
• Aminophylline and respiratory muscle interaction in normal humans [32].
• The adverse effect of long-term steroid treatment on respiratory muscle function remains controversial [33].
• Low-dose acetazolamide does affect respiratory muscle function in spontaneously breathing anesthetized rabbits [34].

Gene context of Respiratory Muscles

• In this study, we evaluated the expression and functional significance of HO-1 and HO-2 in the ventilatory muscles of normal rats and rats injected with bacterial lipopolysaccharide (LPS) [35].
• We conclude that whole body exercise training enhances both limb and ventilatory muscle NO production and that constitutive and not iNOS isoforms are responsible for increased protein tyrosine nitration in trained limb muscles [36].
• Daily respiratory muscle training in mdx mice, induces a beneficial effect on diaphragm strength, with an over-expression of alpha-dystrobrevin [37].
• Myosin gene expression in the respiratory muscles [38].
• Muscle respiratory capacity was not increased in the NRF-1 transgenic mice [39].

Analytical, diagnostic and therapeutic context of Respiratory Muscles

• To study the effects of hyperpnea training, we randomized 30 patients with COPD and ventilatory limitation to respiratory muscle training (RMT; n = 15) with a new portable device or to breathing exercises with an incentive spirometer (controls; n = 15) [40].
• The assessment included lung volumes (TLC, VC, RV, FRC), spirometry (FVC, FEV1), carbon monoxide transfer factor (TLCO adjusted for haemoglobin), inspiratory and expiratory respiratory muscle strength (Pimax and Pemax), 6 minute walk distance (6MWD), chest radiographs, and HRQoL by SF-36 questionnaire [41].
• Effect of aminophylline on respiratory muscle strength after upper abdominal surgery: a double blind study [42].
• We conclude that INPV by a pneumowrap ventilator can induce partial respiratory muscle rest in normal subjects and COPD patients [43].
• Eighteen COPD patients enrolled in a comprehensive, multidisciplinary pulmonary rehabilitation program were randomly assigned to perform either: 1) walking, or 2) ventilatory muscle exercise training (VMT) using a prototype, portable device for isocapnic hyperventilation training [44].

References