Abnormal heart rate responses to exercise in non-severe COPD: relationship with pulmonary vascular volume and ventilatory efficiency.

BACKGROUND: Despite being a prognostic predictor, cardiac autonomic dysfunction (AD) has not been well investigated in chronic obstructive pulmonary disease (COPD). We aimed to characterise computed tomography (CT), spirometry, and cardiopulmonary exercise test (CPET) features of COPD patients with cardiac AD and the association of AD with CT-derived vascular and CPET-derived ventilatory efficiency metrics. METHODS: This observational cohort study included stable, non-severe COPD patients. They underwent clinical evaluation, spirometry, CPET, and CT. Cardiac AD was determined based on abnormal heart rate responses to exercise, including chronotropic incompetence (CI) or delayed heart rate recovery (HRR) during CPET. RESULTS: We included 49 patients with FEV1 of 1.2-5.0 L (51.1-129.7%), 24 (49%) had CI, and 15 (31%) had delayed HRR. According to multivariate analyses, CI was independently related to reduced vascular volume (VV; VV ≤ median; OR [95% CI], 7.26 [1.56-33.91]) and low ventilatory efficiency (nadir VE/VCO2 ≥ median; OR [95% CI], 10.67 [2.23-51.05]). Similar results were observed for delayed HRR (VV ≤ median; OR [95% CI], 11.46 [2.03-64.89], nadir VE/VCO2 ≥ median; OR [95% CI], 6.36 [1.18-34.42]). CONCLUSIONS: Cardiac AD is associated with impaired pulmonary vascular volume and ventilatory efficiency. This suggests that lung blood perfusion abnormalities may occur in these patients. Further confirmation is required in a large population-based cohort.

MASH1 induces neuron transdifferentiation of adrenal medulla chromaffin cells. / MASH1ä»‹å¯¼è‚¾ä¸Šè ºé«“è´¨å—œé“¬ç»†èƒžå‘ç”Ÿç¥žç»å ƒè½¬åˆ†åŒ–.

OBJECTIVES: Nerve growth factor (NGF) induces neuron transdifferentiation of adrenal medulla chromaffin cells (AMCCs) and consequently downregulates the secretion of epinephrine (EPI), which may be involved in the pathogenesis of bronchial asthma. Mammalian achaete scute-homologous 1 (MASH1), a key regulator of neurogenesis in the nervous system, has been proved to be elevated in AMCCs with neuron transdifferentiation in vivo. This study aims to explore the role of MASH1 in the process of neuron transdifferentiation of AMCCs and the mechanisms. METHODS: Rat AMCCs were isolated and cultured. AMCCs were transfected with siMASH1 or MASH1 overexpression plasmid, then were stimulated with NGF and/or dexamethasone, PD98059 (a MAPK kinase-1 inhibitor) for 48 hours. Morphological changes were observed using light and electron microscope. Phenylethanolamine-N-methyltransferase (PNMT, the key enzyme for epinephrine synthesis) and tyrosine hydroxylase were detected by immunofluorescence. Western blotting was used to test the protein levels of PNMT, MASH1, peripherin (neuronal markers), extracellular regulated protein kinases (ERK), phosphorylated extracellular regulated protein kinases (pERK), and JMJD3. Real-time RT-PCR was applied to analyze the mRNA levels of MASH1 and JMJD3. EPI levels in the cellular supernatant were measured using ELISA. RESULTS: Cells with both tyrosine hydroxylase and PNMT positive by immunofluorescence were proved to be AMCCs. Exposure to NGF, AMCCs exhibited neurite-like processes concomitant with increases in pERK/ERK, peripherin, and MASH1 levels (all P<0.05). Additionally, impairment of endocrine phenotype was proved by a signifcant decrease in the PNMT level and the secretion of EPI from AMCCs (all P<0.01). MASH1 interference reversed the effect of NGF, causing increases in the levels of PNMT and EPI, conversely reduced the peripherin level and cell processes (all P<0.01). MASH1 overexpression significantly increased the number of cell processes and peripherin level, while decreased the levels of PNMT and EPI (all P<0.01). Compared with the NGF group, the levels of MASH1, JMJD3 protein and mRNA in AMCCs in the NGF+PD98059 group were decreased (all P<0.05). After treatment with PD98059 and dexamethasone, the effect of NGF on promoting the transdifferentiation of AMCCs was inhibited, and the number of cell processes and EPI levels were decreased (both P<0.05). In addition, the activity of the pERK/MASH1 pathway activated by NGF was also inhibited. CONCLUSIONS: MASH1 is the key factor in neuron transdifferentiation of AMCCs. NGF-induced neuron transdifferentiation is probably mediated via pERK/MASH1 signaling.

Neutrophil Extracellular Trapping Network Promotes the Pathogenesis of Neutrophil-associated Asthma through Macrophages.

Asthma is a complex airway inflammatory disease that can be roughly classified into eosinophilic phenotype and non-eosinophilic phenotype. Most of the latter manifested as airway inflammation dominated by neutrophil infiltration, namely neutrophil-dominated asthma (NA). Neutrophil extracellular trapping (NETs) is a newly discovered antimicrobial mechanism of neutrophils; however, NETs can not only resist killing pathogenic microorganisms, but also promote tissue damage and autoimmune response. In the present study, we successfully established NA model in C57BL/6 mice and observed the increased formation of NETs. In NA mice, the free DNA abundance, the airway resistance, the cell numbers (total cell number, macrophage number, and neutrophil number), and inflammatory cytokine levels were significantly increased while the lung dynamic compliance was significantly reduced. After DNase I treatment, the above indexes in NA mice were all improved. In NA mice, either treatment with macrophage scavenger or IL-1ß neutralizing antibody also improved the above-described indexes. In vitro, in human peripheral blood-derived neutrophils, PMA treatment significantly increased the formation of NETs. Furthermore, in macrophages differentiated from THP-1 monocytes, LPS or isolated NETs both significantly increased the levels of cytokines. In conclusion, NETs can stimulate macrophages to secrete IL-1ß, which promotes neutrophils infiltration in the airway; infiltrated neutrophils, in turn, generates NETs, which can amplify the tissue damage caused by NETs and macrophages, inducing and aggravating NA.

Respiratory syncytial virus infection-induced mucus secretion by down-regulation of miR-34b/c-5p expression in airway epithelial cells.

Severe RSV infection is the main cause of hospitalization to children under the age of five. The regulation of miRNAs on the severity of RSV infection is unclear. The aim of the study was to identify the critical differential expression miRNAs (DE miRNAs) that can regulate the pathological response in RSV-infected airway epithelial cells. In this study, miRNA and mRNA chips of RSV-infected airway epithelia from Gene Expression Omnibus (GEO) were screened and analysed, separately. DE miRNAs-targeted genes were performed for further pathway and process enrichment analysis. DE miRNA-targeted gene functional network was constructed on the basis of miRNA-mRNA interaction. The screened critical miRNA was also investigated by bioinformatics analysis. Then, RSV-infected human bronchial epithelial cells (HBECs) were constructed to verify the expression of the DE miRNAs. Finally, specific synthetic DE miRNAs mimics were used to confirm the effect of DE miRNAs on the RSV-infected HBECs. 45 DE miRNAs were identified from GEO62306 dataset. Our results showed that hsa-mir-34b-5p and hsa-mir-34c-5p decreased significantly in HBECs after RSV infection. Consistent with the biometric analysis, hsa-mir-34b/c-5p is involved in the regulation of mucin expression gene MUC5AC. In RSV-infected HBECs, the inducement of MUC5AC production by decreased hsa-mir-34b/c-5p was partly mediated through activation of c-Jun. These findings provide new insights into the mechanism of mucus obstruction after RSV infection and represent valuable targets for RSV infection and airway obstruction treatment.

miR-146b overexpression ameliorates lipopolysaccharide-induced acute lung injury in vivo and in vitro.

Acute respiratory distress syndrome (ARDS) is a type of acute lung injury (ALI), which causes high morbidity and mortality. So far, effective clinical treatment of ARDS is still limited. Recently, miR-146b has been reported to play a key role in inflammation. In the present study, we evaluated the functional role of miR-146b in ARDS using the murine model of lipopolysaccharide (LPS)-induced ALI. The miR-146b expression could be induced by LPS stimulation, and miR-146b overexpression was required in the maintenance of body weight and survival of ALI mice; after miR-146b overexpression, LPS-induced lung injury, pulmonary inflammation, total cell and neutrophil counts, proinflammatory cytokines, and chemokines in bronchial alveolar lavage (BAL) fluid were significantly reduced. The promotive effect of LPS on lung permeability through increasing total protein, albumin and IgM in BAL fluid could be partially reversed by miR-146b overexpression. Moreover, in murine alveolar macrophages, miR-146b overexpression reduced LPS-induced TNF-α and interleukin (IL)-1ß releasing. Taken together, we demonstrated that miR-146b overexpression could effectively improve the LPS-induced ALI; miR-146b is a promising target in ARDS treatment.

Variable DNA methylation of aging-related genes is associated with male COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic lung inflammatory disease which has a close relationship with aging. Genome-wide analysis reveals that DNA methylation markers vary obviously with age. DNA methylation variations in peripheral blood have the potential to be biomarkers for COPD. However, the specific DNA methylation of aging-related genes in the peripheral blood of COPD patients remains largely unknown. METHODS: Firstly, 9 aging-related differentially expressed genes (DEGs) in COPD patients were screened out from the 25 aging-related genes profile through a comprehensive screening strategy. Secondly, qPCR and multiple targeted bisulfite enrichment sequencing (MethTarget) were used to detect the mRNA level and DNA methylation level of the 9 differentially expressed genes in the peripheral blood of 60 control subjects and 45 COPD patients. The candidate functional CpG sites were selected on the basis of the regulation ability of the target gene expression. Thirdly, the correlation was evaluated between the DNA methylation level of the key CpG sites and the clinical parameters of COPD patients, including forced expiratory volume in one second (FEV1), forced expiratory volume in one second as percentage of predicted volume (FEV1%), forced expiratory volume/ forced vital capacity (FEV/FVC), modified British medical research council (mMRC) score, acute exacerbation frequency and the situation of frequent of acute aggravation (CAT) score. Lastly, differentially methylated CpG sites unrelated to smoking were also determined in COPD patients. RESULTS: Of the 9 differentially expressed aging-related genes, the mRNA expression of 8 genes were detected to be significantly down-regulated in COPD group, compared with control group. Meanwhile, the methylated level of all aging-related genes was changed in COPD group containing 219 COPD-related CpG sites in total. Notably, 27 CpG sites of FOXO3 gene showed a lower False Discovery Rate (FDR) and higher methylation difference values. Also, some variable DNA methylation is associated with the severity of COPD. Additionally, of the 219 COPD-related CpG sites, 147 CpG sites were not related to smoking. CONCLUSION: These results identified that the mRNA expression and DNA methylation level of aging-related genes were changed in male COPD patients, which provides a molecular link between aging and COPD. The identified CpG markers are associated with the severity of COPD and provide new insights into the prediction and identification of COPD.

Analysis of the Clinical Features of Tracheobronchial Fungal Infections with Tumor-Like Lesions.

BACKGROUND: Tracheobronchial fungal infections (TBFI) cause life-threatening complications in immunocompromised hosts but are rarely reported. Misdiagnosis and delayed antifungal treatment are associated with the high mortality rate of patients with TBFI. OBJECTIVES: This study analyzed the bronchoscopic features of TBFI and their roles in the early diagnosis of TBFI. METHODS: The demographic, clinical, radiologic, and bronchoscopic data of 53 patients diagnosed with TBFI in our department during a 15-year period were retrospectively analyzed. RESULTS: Most of the TBFI patients were male, and mass was the most common radiologic abnormality. Obvious predilection in primary bronchus distributions was observed. 41.9% of the 43 Aspergillus tracheobronchitis (AT) patients, 70% of the 10 tracheobronchial mucormycosis (TM) patients, and 100% of the 3 endobronchial cryptococcosis patients had been misdiagnosed as having cancer on bronchoscopy because of the presence of tumor-like lesions. The most common features of AT were bronchial occlusion with a mass or mucosal necrosis, bronchial stenosis with mucosal hyperplasia, or uneven mucosa. The main descriptions of TM were bronchial stenosis or obstruction due to mucosal necrosis, uneven mucosa, or a mass. The endoscopic characteristics of endobronchial cryptococcosis included occlusion due to uneven mucosa or mass, or external compressive stricture. CONCLUSION: Immunocompromised patients and immunocompetent patients with underlying disease displaying tumor-like lesions on bronchoscopy should be differentially diagnosed with cancer. Bronchial biopsy is indispensable for the early diagnosis of TBFI.

Glucocorticoids Modulate Th1 and Th2 Responses in Asthmatic Mouse Models by Inhibition of Notch1 Signaling.

BACKGROUND: Notch1 has been linked to the pathogenesis of asthma due to its contribution on Th1/Th2 imbalance. γ-Secretase inhibitor (GSI) acts as an effective blocker of Notch1 signaling. Glucocorticoids (GCs) are the most effective anti-inflammatory drugs for asthma. The present study investigated the involvement of the Notch1 pathway in the anti-inflammatory effect of GCs and its association with Th1/Th2 balance. METHODS: The asthma model was established in BALB/c mice by sensitization with ovalbumin (OVA). Dexamethasone (DEX; 1 mg/kg) and/or GSI (0.03 mg/kg) was orally or intranasally administrated. RESULTS: Compared to the OVA-sensitized mice, the administration of DEX and/or GSI significantly ameliorated the airway inflammation infiltration, goblet cell metaplasia, and airway hyper-responsiveness. The expression of IL-4 and IL-13, as well as the ratios of eosinophils and lymphocytes, were significantly decreased, whereas IFN-γ and IL-2 levels were significantly increased in bronchoalveolar lavage fluid after the administration of DEX and GSI. The expressions of the Notch1/NICD1 pathway were decreased after DEX and/or GSI administration in lung tissues, especially in CD4+ T cells. Also, a reduction of GATA3 and elevation of T-bet levels were correlated with the upregulation of Th1/Th2 ratios in lung tissues. CONCLUSIONS: Through the inhibition of Notch1 signaling, both GSI and GCs could regulate Th1/Th2 balance involved in allergic airway inflammation in OVA-induced asthma.

The effect of H19-miR-29b interaction on bleomycin-induced mouse model of idiopathic pulmonary fibrosis.

Pulmonary fibrosis, characterized by the destruction of lung tissue architecture and the formation of fibrous foci, currently has no satisfactory treatment. Emodin is a component of Chinese herb that has been reported to be medicable on pancreatic fibrosis and liver fibrosis. However, its role in pulmonary fibrosis has not been reported yet. In the present study, we investigated the hypothesis that H19 play a promotive role in bleomycin-induced epithelial-mesenchymal transition of alveolar epithelial cell, and H19 exerts its effect through miR-29b regulation. H19 expression was positively correlated with COL1A1 and Acta2 expression; H19 knockdown inhibited COL1A1 and Acta2 expression. Moreover, H19 interacted with miR-29b through directly binding to the 3'UTR; miR-29b inhibited COL1A1 expression by directly binding to the 3'UTR. In conclusion, we revealed the promotive effect of H19 on BLM-induced IPF, and demonstrated the mechanism by which H19/miR-29b interaction exerts its effect on regulating pulmonary fibrosis. The present study provided a potential therapy to treat IPF.

[Clinical comparative analysis for pulmonary histoplasmosis and progressive disseminated histoplasmosis].

OBJECTIVE: To compare clinical features, diagnosis and therapeutic effect between pulmonary histoplasmosis and progressive disseminated histoplasmosis.
 Methods: A retrospective analysis for 12 cases of hospitalized patients with histoplasmosis, who was admitted in Xiangya Hospital, Central South University during the time from February 2009 to October 2015, was carried out. Four cases of pulmonary histoplasmosis and 8 cases of progressive disseminated histoplasmosis were included. The differences of clinical features, imaging tests, means for diagnosis and prognosis were analyzed between the two types of histoplasmosis.
 Results: The clinical manifestations of pulmonary histoplasmosis were mild, such as dry cough. However, the main clinical symptoms of progressive disseminated histoplasmosis were severe, including recurrence of high fever, superficial lymph node enlargement over the whole body, hepatosplenomegaly, accompanied by cough, abdominal pain, joint pain, skin changes, etc.Laboratory examination showed pancytopenia, abnormal liver function and abnormal coagulation function. One pulmonary case received the operation of left lower lung lobectomy, 3 cases of pulmonary histoplasmosis and 6 cases of progressive disseminated histoplasmosis patients were given deoxycholate amphotericin B, itraconazole, voriconazole or fluconazole for antifungal therapy. One disseminated case discharged from the hospital without treatment after diagnosis of histoplasmosis, and 1 disseminated case combined with severe pneumonia and active tuberculosis died ultimately.
 Conclusion: As a rare fungal infection, histoplasmosis is easily to be misdiagnosed. The diagnostic criteria depends on etiology through bone marrow smear and tissues biopsy. Liposomeal amphotericin B, deoxycholate amphotericin B and itraconazole are recommended to treat infection for histoplasma capsulatum.

Leptin Is Oversecreted by Respiratory Syncytial Virus-Infected Bronchial Epithelial Cells and Regulates Th2 and Th17 Cell Differentiation.

BACKGROUND: Infection of human bronchial epithelial cells (hBECs) with respiratory syncytial virus (RSV) has been shown to induce a Th lymphocyte subset drift, e.g. enhanced differentiation of Th2 and Th17 subsets, which is a classic characteristic of asthma. However, the molecules responsible for the drift in Th subsets remain unknown. This study aims to determine the expression of leptin in RSV-infected hBECs, and its role in Th2 and Th17 cell differentiation and extracellular regulated kinase (ERK) 1/2 phosphorylation. METHODS: Cultured hBECs were infected with RSV. mRNA expression of the LEP gene in cells was measured by real-time PCR while LEP protein secretion in culture medium was measured by ELISA. Th differentiation was investigated in cultured human peripheral blood mononuclear cells following stimulation with recombinant human leptin. Th2 and Th17 subsets were examined by flow cytometry. Phosphorylation of the ERK1/2 protein in lymphocytes was detected by Western blot and immunofluorescence. RESULTS: LEP mRNA expression was significantly upregulated in RSV-infected hBECs while the leptin protein level in the supernatants of RSV-infected hBECs was significantly increased. Stimulation of lymphocytes with leptin increased the differentiation of the Th17 subset and ERK1/2 phosphorylation, but suppressed Th2 subset differentiation. CONCLUSION: Leptin was oversecreted by RSV-infected hBECs, which promoted Th17 subset differentiation but suppressed Th2 subset differentiation possibly via regulating ERK1/2 phosphorylation.

The effect of tai chi on chronic obstructive pulmonary disease: a pilot randomised study of lung function, exercise capacity and diaphragm strength.

BACKGROUND: Although the benefits of exercise on the health of patients with chronic obstructive pulmonary disease (COPD) have been widely reported, the effect of Tai Chi as an alternative exercise has not been thoroughly evaluated in patients with COPD. This study reported a randomised controlled trial, which investigated the effects of Tai Chi on lung function, exercise capacity, and diaphragm strength in patients with COPD. TRIAL DESIGN: Single blind randomised controlled study. SETTING: Department of Respiratory Medicine, Xiangya Hospital, Central South University. METHODS: Forty patients with COPD were randomised into either a control group or Tai Chi intervention group. Participants in the control group received only routine care, while participants in the Tai Chi group received routine care and completed a six-month Tai Chi exercise program. OUTCOMES: Lung function parameters, blood gas parameters, 6-min walking distance (6MWD), and diaphragm strength parameters. RESULTS: Lung function parameters (FEV1: 1.43 ± 0.08 and FEV1 (%) predicted: 47.6 ± 4.76), 6MWD (476 ± 15) and diaphragm strength parameters (TwPes: 1.17 ± 0.07, TwPga: -1.12 ± 0.06, and TwPdi: 1.81 ± 0.09) were found to be significantly increased in participants who successfully completed the six-month Tai Chi program compared to participants in the control group who only received routine care (p<0.05). These parameters were also found to be significantly increased in participants who completed the Tai Chi exercise program compared to the baseline (p<0.05). In contrast, no significant differences in PaO2 and PaCO2 were observed in participants before or after completing a Tai Chi program or between Tai Chi group and control group (p>0.05). CONCLUSIONS: Tai Chi enhances lung function, exercise capacity, and diaphragm strength. However, this is only preliminary research data and a larger trial is needed for more detailed results.

Developing and validating prediction models for severe exacerbations and readmissions in patients hospitalised for COPD exacerbation (SERCO) in China: a prospective observational study.

BACKGROUND: There is a lack of individualised prediction models for patients hospitalised with chronic obstructive pulmonary disease (COPD) for clinical practice. We developed and validated prediction models of severe exacerbations and readmissions in patients hospitalised for COPD exacerbation (SERCO). METHODS: Data were obtained from the Acute Exacerbations of Chronic Obstructive Pulmonary Disease Inpatient Registry study (NCT02657525) in China. Cause-specific hazard models were used to estimate coefficients. C-statistic was used to evaluate the discrimination. Slope and intercept were used to evaluate the calibration and used for model adjustment. Models were validated internally by 10-fold cross-validation and externally using data from different regions. Risk-stratified scoring scales and nomograms were provided. The discrimination ability of the SERCO model was compared with the exacerbation history in the previous year. RESULTS: Two sets with 2196 and 1869 patients from different geographical regions were used for model development and external validation. The 12-month severe exacerbations cumulative incidence rates were 11.55% (95% CI 10.06% to 13.16%) in development cohorts and 12.30% (95% CI 10.67% to 14.05%) in validation cohorts. The COPD-specific readmission incidence rates were 11.31% (95% CI 9.83% to 12.91%) and 12.26% (95% CI 10.63% to 14.02%), respectively. Demographic characteristics, medical history, comorbidities, drug usage, Global Initiative for Chronic Obstructive Lung Disease stage and interactions were included as predictors. C-indexes for severe exacerbations were 77.3 (95% CI 70.7 to 83.9), 76.5 (95% CI 72.6 to 80.4) and 74.7 (95% CI 71.2 to 78.2) at 1, 6 and 12 months. The corresponding values for readmissions were 77.1 (95% CI 70.1 to 84.0), 76.3 (95% CI 72.3 to 80.4) and 74.5 (95% CI 71.0 to 78.0). The SERCO model was consistently discriminative and accurate with C-indexes in the derivation and internal validation groups. In external validation, the C-indexes were relatively lower at 60-70 levels. The SERCO model discriminated outcomes better than prior severe exacerbation history. The slope and intercept after adjustment showed close agreement between predicted and observed risks. However, in external validation, the models may overestimate the risk in higher-risk groups. The model-driven risk groups showed significant disparities in prognosis. CONCLUSION: The SERCO model provides individual predictions for severe exacerbation and COPD-specific readmission risk, which enables identifying high-risk patients and implementing personalised preventive intervention for patients with COPD.

Efficacy and safety of a music-therapy facilitated pulmonary telerehabilitation program in COPD patients: the COPDMELODY study protocol.

Despite considerable evidence for the benefit in chronic obstructive pulmonary disease (COPD), the implementation of pulmonary rehabilitation (PR) is insufficient. However, music therapy may help address this gap due to its unique benefits. Therefore, we aimed to develop a music-therapy facilitated pulmonary telerehabilitation program based on rhythm-guided walking, singing, and objective telemonitoring. A supervised, parallel-group, single-blinded, randomized controlled clinical trial will be conducted, including 75 patients with COPD anticipated to be randomized in a 1:1:1 ratio into three groups. The intervention groups will receive a 12-week remotely monitored rehabilitation program, while the usual care group will not receive any rehabilitation interventions. Of the two intervention groups, the multi-module music therapy group will contain rhythm-guided walking and singing training, while the rhythm-guided walking group will only include music tempo-guided walking. The primary outcome is the distance of the incremental shuttle walking test. Secondary outcomes include respiratory muscle function, spirometry, lower extremity function, symptoms, quality of life, anxiety and depression levels, physical activity level, training adherence, and safety measurements. The results of this study can contribute to develop and evaluate a home-based music-facilitated rehabilitation program, which has the potential to act as a supplement and/or substitute (according to the needs) for traditional center-based PR in patients with stable COPD. Clinical trial registration: https://classic.clinicaltrials.gov/, NCT05832814.

Associations Between Air Pollution and the Onset of Acute Exacerbations of COPD: A Time-Stratified Case-Crossover Study in China.

BACKGROUND: Associations between air pollution and the acute exacerbations (AEs) of COPD have been established primarily in time-series studies in which exposure and case data were at the aggregate level, limiting the identification of susceptible populations. RESEARCH QUESTION: Are air pollutants associated with the onset of AEs of COPD in China? Who is more susceptible to the effects of air pollutants? STUDY DESIGN AND METHODS: Data regarding AEs of COPD were obtained from the Acute Exacerbation of Chronic Obstructive Pulmonary Disease Registry study, and air pollution data were assigned to individuals based on their residential address. We adopted a time-stratified case-crossover study design combined with conditional logistic regression models to estimate the associations between six air pollutants and AEs of COPD. Stratified analyses were performed by individual characteristics, disease severity, COPD types, and the season of exacerbations. RESULTS: A total of 5,746 patients were included. At a 2-day lag, for each interquartile range increase in fine particulate matter (PM2.5) and inhalable particulate matter (PM10) concentrations, ORs for AEs of COPD were 1.054 (95% CI, 1.012-1.097) and 1.050 (95% CI, 1.009-1.092), respectively. The associations were more pronounced in participants who were younger than 65 years, had experienced at least one severe AE of COPD in the past year, received a diagnosis of COPD between 20 and 50 years of age, and experienced AEs of COPD in the cool seasons. By contrast, significant associations for nitrogen dioxide, sulfur dioxide, and carbon monoxide lost significance when excluding patients collected before 2020 or with larger distance from the monitoring station, and no significant association was observed for ozone. INTERPRETATION: This study provides robust evidence that short-term exposure to PM2.5 and PM10 was associated with higher odds of AEs of COPD onset. Individuals who are young, have severe COPD, or whose first diagnosis of COPD was made when they were between 20 and 50 years of age and experience an exacerbation during the cooler seasons may be particularly susceptible. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT2657525; URL: www. CLINICALTRIALS: gov.

High-intensity training induces EIB in rats through neuron transdifferentiation of adrenal medulla chromaffin cells.

A high prevalence of exercise-induced bronchoconstriction (EIB) can be found in elite athletes, but the underlying mechanisms remain elusive. Airway responsiveness, NGF and epinephrine (EPI) levels, and chromaffin cell structure in high- (HiTr) and moderate-intensity training (MoTr) rats with or without ovalbumin (OVA) sensitization were measured in a total of 120 male Sprague-Dawley rats. The expression of NGF-associated genes in rat adrenal medulla was tested. Both HiTr and OVA intervention significantly increased airway resistance to aerosolized methacholine measured by whole body plethysmography. HiTr significantly increased inflammatory reaction in the lung with a major increase in peribronchial lymphocyte infiltration, whereas OVA significantly increased the infiltration of various inflammatory cells with an over 10-fold increase in eosinophil level in bronchoalveolar lavage. Both HiTr and OVA intervention upregulated circulating NGF level and peripherin level in adrenal medulla, but downregulated phenylethanolamine N-methyl transferase level in adrenal medulla and circulating EPI level. HiTr + OVA and HiTr + ExhEx (exhaustive exercise) interventions significantly enhanced most of the HiTr effects. The elevated NGF level was significantly associated with neuronal conversion of adrenal medulla chromaffin cells (AMCC). The levels of p-Erk1/2, JMJD3, and Mash1 were significantly increased, but the levels of p-p38 and p-JNK were significantly decreased in adrenal medulla in HiTr and OVA rats. Injection of NGF antiserum and moderate-intensity training reversed these changes observed in HiTr and/or OVA rats. Our study suggests that NGF may play a vital role in the pathogenesis of EIB by inducing neuron transdifferentiation of AMCC via MAPK pathways and subsequently decreasing circulating EPI.

[Endarterium injury and the related pathway in chronic intermittent hypoxia rats].

OBJECTIVE: To examine the pathological change and intima thickness of thoracic aorta, detect the serum concentration of hypoxia-inducible factor-1α (HIF-1α), oxidized LDL (ox-LDL), and pentraxin 3 (PTX3) in the rat model of chronic intermittent hypoxia (CIH), and to determine the effect of CIH on endarterium injury and its possible pathway. METHODS: Twenty-four male Sprague-Dawley (SD) rats were divided into 4 groups: a CIH+Nacetylcysteine (NAC) group, a CIH+normal saline (NS) group, a CIH control group and a control group. CIH rats were subjected to alternating cycles of hypoxia (6%-8% O2 in N2 for 20-25 s) and normoxia (21% O2 in N2 for 2 min) every 180 s for 7 h/d. Rats in the control group were not treated. Rats in the CIH+NAC group were treated with NAC [800 mL/(kg.d)] intraperitoneal injection, and rats in the CIH+NS group were treated with NS [5 mL/(kg.d)] intraperitoneal injection. After 42 day treatment, the rats were sacrificed, blood taken, and thoracic aorta cut off. The serum concentration of HIF-1α, ox-LDL, and PTX3 were detected by ELISA. The thickness of intima was taken by computer digital image analysis. RESULTS: Vascular endothelial cell injury and detachment were found in the thoracic aorta in the CIH and the CIH+NS group. The intima in the CIH and the CIH+NS group was thicker than that in the control and the CIH+NAC group (P<0.001). The serum concentration of HIF-1α, ox-LDL, and PTX3 in the CIH and the CIH+NS group was higher than that in the control and the CIH+NAC group (P<0.001). The serum concentration of HIF-1α, ox-LDL, and PTX3 was pairwise positive correlation, and the serum concentration of ox-LDL and PTX3 was positively correlated with the thickness of intina (P<0.001). CONCLUSION: The vascular endothelial cell injury and endarterium thickening can be induced by CIH. It is an important pathway that CIH activates oxidative stress and elevates the levels of HIF- 1α, ox-LDL, and PTX3.

Nebulization versus metered-dose inhaler and spacer in bronchodilator responsiveness testing: a retrospective study.

BACKGROUND: The recommended delivery mode for bronchodilators in bronchodilator responsiveness (BDR) testing remains controversial. OBJECTIVE: To compare the efficacy of salbutamol administration using a nebulizer versus a metered-dose inhaler (MDI) with spacer in BDR testing. DESIGN: A retrospective study. METHODS: This study examined the data of patients with chronic obstructive pulmonary disease who completed BDR testing between 1 December 2021 and 30 June 2022, at Xiangya Hospital, Central South University. After administering 400 µg of salbutamol through an MDI with spacer or 2.5 mg using a nebulizer, the changes in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were analyzed in patients with moderate-to-very severe spirometric abnormalities [pre-bronchodilator FEV1 percentage predicted values (FEV1%pred) ⩽59%]. Significant responsiveness was assessed as >12% and >200 mL improvement in FEV1 and/or FVC or >10% increase in FEV1%pred or FVC percentage predicted values (FVC%pred) from pre- to post-bronchodilator administration. RESULTS: Of the enrolled 894 patients, 83.2% were male (median age, 63 years). After propensity score matching, 240 pairs of patients were selected. The increment in FEV1 and increased FEV1 relative to the predicted value (ΔFEV1%pred) were significantly higher in patients <65 years and those with severe spirometric abnormalities in the nebulization group than patients in the MDI group (all p < 0.05). Compared with MDI with spacer, patients who used nebulization had a 30 mL greater increase in ΔFEV1 (95% CI: 0.01-0.05, p = 0.004) and a 1.09% greater increase in ΔFEV1%pred (95% CI: 0.303-1.896, p = 0.007) from baseline. According to the > 12% and >200 mL increase criterion, the significant BDR rate with nebulization was 1.67 times higher than that with an MDI with spacer (OR = 1.67, 95% CI: 1.13-2.47, p = 0.009). CONCLUSION: Salbutamol delivered using a nebulizer may be preferable to an MDI with spacer in certain circumstances. Nebulization has the potential to increase responsiveness to salbutamol in BDR testing.

Nebulization versus metered-dose inhaler and spacer in bronchodilator responsiveness testingBronchodilator responsiveness testing is commonly undertaken as an important part of spirometry testing to determine the degree of volume and airflow improvement after bronchodilator administration. BDR testing results may affect patients' diagnosis and treatment. This study compared the effects of two delivery models (a metered dose inhaler (MDI) with spacer and nebulization) on responsiveness to bronchodilators and the results of bronchodilator responsiveness testing among patients with chronic obstructive pulmonary disease. We found that the increment in forced expiratory volume in one second were significantly higher in patients aged <65 years and in those with severe spirometric abnormalities in the nebulization group than in those in the MDI group. The study provides evidence that salbutamol delivered by a nebulizer is preferable to an MDI with spacer in patients <65 years and in those with severe spirometric abnormalities and could increase positive responsiveness to bronchodilators. The study will assist in clinical decision-making by selecting the appropriate dosing regimen for different patients.

Re-exacerbation within 30 days of discharge is associated with poor prognosis in the following year among patients hospitalised with exacerbation of chronic obstructive pulmonary disease: a clinical cohort study.

BACKGROUND: Exacerbation of chronic obstructive pulmonary disease (ECOPD) is a complex phenomenon, with marked heterogeneity in the aetiology, pathophysiology and clinical manifestations. This study aimed to evaluate the clinical characteristics and long-term outcomes of patients with 30-day exacerbation among those hospitalised with ECOPD in China. METHODS: Data from the Acute Exacerbations of Chronic Obstructive Pulmonary Disease Inpatient Registry were used in this study. The patients were divided into re-event and non-event groups based on the incidence of re-exacerbation within 30 days of discharge. Exacerbation, severe exacerbation and all-cause readmissions in the following 12 months were the outcomes of interest. The cumulative incidence rates and incidence densities were calculated. Multivariate hazard function models were used to determine the association between 30-day re-exacerbation and the long-term outcomes after accounting for the competing risk of death. RESULTS: Re-exacerbation within 30 days of discharge was observed in 4.9% (n=242) of the patients (n=4963). The cumulative incidence rates and incidence densities of exacerbation, severe exacerbation and all-cause readmissions in the event group were significantly higher than those in the non-event group. After adjustment, re-exacerbation within 30 days of discharge was associated with increased risks of exacerbation, severe exacerbation and all-cause readmissions in the following 12 months (adjusted HR: 3.85 (95% CI: 3.09 to 4.80), 3.46 (2.66 to 4.50) and 3.28 (2.52 to 4.25) accordingly). CONCLUSION: Re-exacerbation of COPD within 30 days of discharge is a significant predictor of long-term prognosis. In clinical practice, short-term re-exacerbation is a significant clinical phenotype of ECOPD that requires careful management at the earliest.

Mortality and readmission risk for hospitalised patients with acute exacerbation of COPD with and without spirometric obstruction: a longitudinal observational study in China.

OBJECTIVE: To compare the clinical features and outcomes in patients with pre-chronic obstructive pulmonary disease (COPD) and COPD hospitalised for confirmed or suspected acute exacerbation of COPD (AECOPD). DESIGN: A multicentre, longitudinal observational cohort study. SETTING: Data were obtained from the AECOPD Inpatient Registry Study in China. PARTICIPANTS: 5896 patients hospitalised for AECOPD between 2017 and 2021. OUTCOMES: Patients were divided into the COPD (n=5201) and pre-COPD (n=695) groups according to the lung function test results. The outcomes of interest included all-cause, respiratory disease-related and cardiovascular disease-related deaths as well as readmissions within 30 days and 12 months after discharge. Cumulative incidence functions were used to estimate the risk of cause-specific mortality and readmission. Multivariate hazard function models were used to determine the association between lung function and outcomes. RESULTS: There were significant between-group differences in the symptoms at admission and medication use during hospitalisation. However, there was no significant between-group difference in the 30-day all-cause mortality (0.00 vs 2.23/1000 person-month (pm), p=0.6110) and readmission (33.52 vs 30.64/1000 pm, p=0.7175). Likewise, the 30-day and 12-month cause-specific outcomes were not significantly different between groups (30-day readmission with acute exacerbation (AE): 26.07 vs 25.11/1000 pm; 12-month all-cause mortality: 0.20 vs 0.93/1000 pm; all-cause readmission: 11.49 vs 13.75/1000 pm; readmission with AE: 9.15 vs 11.64/1000 pm, p>0.05 for all comparisons). Cumulative incidence curves revealed no significant between-group differences in the 30-day and 12-month prognosis (p>0.05). Multivariate analysis revealed no significant association of lung function categories with 30-day and 12-month mortality or readmission (p>0.05 for all effect estimations). CONCLUSIONS: Patients with pre-COPD have mild symptoms and similar risks for mortality and readmission during follow-up as patients with COPD. Patients with pre-COPD should receive optimal therapies before the occurrence of irreversible damage.