Respiratory physiology & neurobiology
-
Respir Physiol Neurobiol · Jun 2014
Randomized Controlled TrialAntagonism of substance P and perception of breathlessness in patients with chronic obstructive pulmonary disease.
The objective of this study was to investigate whether substance P, an excitatory neuropeptide, modulates the perception of breathlessness by administering aprepitant, a selective antagonist that blocks neurokinin (NK)-1 receptor signaling. Individual targeted resistive load breathing (RLB) was used to provoke breathlessness. In Study 1, sixteen patients (age, 70±6 years) with chronic obstructive pulmonary disease (COPD) reported similar ratings of breathlessness during RLB between oral aprepitant (125mg) and placebo. ⋯ Nine patients with COPD reported comparable breathlessness ratings during RLB between aprepitant and placebo. Our results do not support a role for the substance P-NK-1 pathway in the perception of breathlessness in patients with COPD. With selective antagonism of NK-1 signaling, there was co-transmission of substance P and beta-endorphin neuropeptides.
-
Respir Physiol Neurobiol · May 2014
Comparative Study Clinical TrialPhysiological comparison of breathing patterns with neurally adjusted ventilatory assist (NAVA) and pressure-support ventilation to improve NAVA settings.
Neurally adjusted ventilator assist (NAVA) assists spontaneous breathing in proportion to diaphragmatic electrical activity (EAdi). Here, we evaluate the effects of various levels of NAVA and PSV on the breathing pattern and, thereby, on [Formula: see text] homeostasis in 10 healthy volunteers. For each ventilation mode, four levels of support (delivered pressure 0 i.e. baseline, 5, 8, and 10cmH2O) were tested in random order. ⋯ Diaphragmatic activity can decrease during NAVA without any change in VT and [Formula: see text]. This suggests that NAVA adjustment cannot be based solely on VT and [Formula: see text] criteria. Registered by Frédéric Lofaso and Nicolas Terzi on ClinicalTrials.gov, #NCT01614873.
-
Respir Physiol Neurobiol · Apr 2014
People with older age and lower FEV1%pred tend to have a smaller FVC than VC in pre-bronchodilator spirometry.
We enrolled 1772 subjects who underwent pulmonary function test before preoperative examination in our study. Pre-bronchodilator forced expiratory volume in one second (FEV1), vital capacity (VC) and forced vital capacity (FVC) were measured as primary data. According to the numerical relationship between VCmax and FVC, two groups were divided: VCmax>FVC and VCmax=FVC. ⋯ Of the 1772 spirometric results analyzed, 614 (34.65%) with VCmax=FVC and 1158 (65.35%) with VCmax>FVC were identified. Compared to VCmax=FVC group, subjects in VCmax>FVC group have older age (95%CI [1.50, 3.99], P<0.001), lower FEV1%pred (95%CI [-12.22, -8.07], P<0.001) and lower FEV1/VCmax (95%CI [-0.07, -0.05], P<0.001), parameters such as height, weight, BMI, FEV1/FVC showed no statistical significance. We made a conclusion that people with older age and lower FEV1%pred tend to have a smaller FVC than VC in pre-bronchdilator spirometry.
-
Respir Physiol Neurobiol · Mar 2014
PcrV antibody protects multi-drug resistant Pseudomonas aeruginosa induced acute lung injury.
Blocking PcrV, an essential component of the Type III secretion system (TTSS), has demonstrated efficacy against Pseudomonas aeruginosa infections. However, most of the results came from laboratory strains. Whether it is applicable to clinically isolated multi-drug resistant (MDR) strains is unknown. ⋯ Our results showed that the expression level of TTSS in MDR strains is comparable to susceptible strains. Anti-PcrV ensured the survival of challenged mice, reduced the bacteria numbers and attenuated lung inflammation and injury. This study proved that anti-PcrV may be a potentially effective strategy against MDR P. aeruginosa induced ALI.