Respiratory physiology & neurobiology
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Respir Physiol Neurobiol · Jun 2012
Comparative StudyActivity-related dyspnea is not modified by psychological status in people with COPD, interstitial lung disease or obesity.
Sensory (physiological) and affective (psychological) dimensions of dyspnea have been described but the usefulness of measuring psychological status in addition to ventilatory capacity (spirometry, lung volumes) in the assessment of exertional dyspnea remains controversial. We hypothesized that activity-related dyspnea would not be modified by psychological status. ⋯ Ventilatory capacity was described by three main dimensions by PCA related to airways, volumes, and their combination (specific airway resistance, FEV(1)/FVC), which were weakly correlated with dyspnea. In conclusion, in patients with COPD, interstitial lung disease or severe obesity, psychological status does not modify activity-related dyspnea rating as evaluated by the MRC scale.
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Respir Physiol Neurobiol · Jun 2012
Anti-inflammatory and neuroprotective effects of triptolide on traumatic brain injury in rats.
Traumatic brain injury (TBI) is characterized by neuroinflammation, brain edema, and cerebral damage leading to impairment of neurobehavioral function. Triptolide (PG-490), a diterpenoid component from Tripterygium wilfordii Hook F., has anti-inflammatory properties. Whether triptolide has neuroprotective functions when treating TBI is unclear. ⋯ Thriptolide reversed the TBI-induced decrease in brain levels of anti-inflammatory cytokine interleukin-10. Importantly, triptolide improved neurobehavioral outcomes regarding motor, sensory, reflex and balance function. We conclude that triptolide confers neuroprotection against TBI, at least in part, via its anti-inflammatory activity.
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Respir Physiol Neurobiol · May 2012
Comparative StudyImpact of mechanical ventilation and fluid load on pulmonary glycosaminoglycans.
The combined effect of mechanical ventilation and fluid load on pulmonary glycasaminoglycans (GAGs) was studied in anaesthetized rats ((BW 290±21.8 (SE)g) mechanically ventilated for 4h: (a) at low (∼7.5mlkg(-1)) or high (∼23mlkg(-1)) tidal volume (V(T)) and zero alveolar pressure; (b) at low or high V(T) at 5cmH(2)O positive end-expiratory pressure (PEEP); (c) with or without 7mlkg(-1)h(-1) intravenous infusion of Phosphate Buffer Solution (PBS). Compared to spontaneous breathing, GAGs extractability decreased by 52.1±1.5% and 42.2±7.3% in not-infused lungs mechanically ventilated at low V(T) or at high V(T) and PEEP, respectively. ⋯ In the absence of an inflammatory process, these results suggest that PEEP was protective at low but not at high V(T) when alveolar structures experience exceedingly high stresses. When combined to mechanical ventilation, fluid load might exacerbate edema development and lung injury.
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Respir Physiol Neurobiol · Apr 2012
Urge-to-cough and dyspnea conceal perception of pain in healthy adults.
Although dyspnea has been shown to attenuate pain, whether urge-to-cough, a respiratory sensation preceding cough, exerts a similar inhibitory effect on pain has not been clarified. We examined the effects of both urge-to-cough and dyspnea on pain induced by thermal noxious stimuli. Urge-to-cough was induced by citric acid challenge and dyspnea was induced by external inspiratory resistive loads. ⋯ Fractional change in TPTo during dyspnea was significantly correlated with that during urge-to-cough. The study suggests that both two distinct respiratory sensations, i.e., urge-to-cough and dyspnea may harbor perception of pain. Further studies investigating interactions among these sensations in clinical settings are warranted.
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The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management.