Objective To evaluate the effects of inhaled bronchodilators on respiratory mechanics in moderate and severe chronic obstructive pulmonary disease（COPD） patients during eupnea.Methods Twenty moderate to severe COPD subjects were divided into three groups.Lung function，Borg score，breathing pattern and respiratory mechanics indexes were measured at baseline and 30 min after inhaled placebo，salbutamol 400 μg (or ipratropium 80 μg)，and ipratropium 80 μg (or salbutamol 400 μg) in sequence at interval as specified in different groups.Results In all groups，inhaled bronchodilators improved lung function (FEV1，FVC，IC) (Plt;0.05)，decreased Pdi，Peso，PTPdi，PTPeso and Raw (Plt;0.05，respectively)，in comparison with placebo.The reduction of PTPeso was positively correlated with the reduction of Peso (r=0.713，Plt;0.01）and Raw (r=0.602，Plt;0.01).Borg score decreased after inhaled bronchodilators (Plt;0.05).The reduction of dyspnea was positively correlated with the reduction of inspiratory work of breathing (ΔPTPeso%) (r=0.339，Plt;0.05) and Raw (ΔRaw) (r=0.358，Plt;0.05)，while was not associated with the changes of FEV1，FVC and IC.Conclusions In COPD patients，inhaled bronchodilators can reduce inspiratory work of breathing and airway resistance，the reduction of inspiratory work of breathing contributed to the reduction of airway resistance.Alleviation of dyspnea by inhaled bronchodilators is suggested to be ascribed to reduction of airway resistance and inspiratory work of breathing.
Objective To investigate the effect of myeloid derived suppressor cells ( MDSCs) on airway inflammation of asthmatic mice. Methods Five male BALB/ c mice aged 6 weeks were used for preparing 4T1 tumor bearing mice. Thirty female BALB/ c mice aged six weeks were randomly divided into a normal control group, an athmatic model group, and a cell transplantation group. The MDSCs were separated frommyeloid tissue of tumor-bearing mice using amagnetic cell sorting systemand cultured in RPMI medium 1640 containing GM-CSF. The morphologic characteristics of these cells were observed under lightmicroscope and the phenotypic figures were analyzed with flow cytometry. The mice in the model group and the cell transplantation group were sensitized by ovalbumin and then stimulated with nebulized ovalbumin. The mice in the cell transplantation group were intravenously administered MDSCs which purified by magnetic cell sorting system at 10 days after sensitization. The airway inflammation was evaluated by HE staining. The total and differential cell counts in bronchoalveolar lavage fluid ( BALF) were measured.Results The neutrophil and eosinophil infiltration in pulmonary tissue was dramatically increased in the model group, but not observed in the normal control group and was much milder in the cell transplantation group. The total cell count, the eosinophil and lymphocyte counts in BALF of the model group and the cell transplantation group were significantly higher than those of the normal control group( P lt; 0. 05) , and the number of eosinophils in BALF of the cell transplantation group was decreased when compared with that of the model group( P lt;0. 05) . Conclusion MDSCs via intravenous infusion can effectively suppress airway inflammation in a mouse asthma model.
ObjectiveTo assess the mortality, acute exacerbations, exercise capacity, symptoms and significant physiological parameters (lung function, respiratory muscle function and gas exchange) of patients with severe stable chronic obstructive pulmonary disease (COPD) with respiratory failure treated by noninvasive positive pressure ventilation (NPPV).MethodsA meta-analysis of randomized controlled trials was carried out by searching PubMed, Cochrane library, Embase, OVID, Chinese Biomedical Literature Database and the bibliographies of the retrieved articles up to February 2017. Studies of patients with severe stable COPD with respiratory failure receiving long-term noninvasive positive pressure ventilation and comparison with oxygen therapy were conducted, and at least one of the following parameters were reviewed: frequency of acute exacerbations, mortality, lung function, respiratory muscle function, gas exchange, 6-minute walk test.ResultsSix studies with 695 subjects met the inclusion criteria and were analyzed. The PaCO2 was significantly decreased in patients who received long-term NPPV. No significant difference was found between long-term NPPV and oxygen therapy in mortality, frequency of acute exacerbations, gas exchange, lung function, respiratory muscle function and exercise capacity. The subgroup analysis showed that NPPV improves survival of patients when it is targeted at greatly reducing hypercapnia.ConclusionCurrent evidence suggests that there is no significant improvement by application of NPPV on severe stable COPD with respiratory failure patients, but NPPV may reduce patients’ mortality with the aim of reducing hypercapnia.