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Metformin has been involved in modulating inflammatory state and inhibiting cell proliferation and angiogenesis. This study aimed to determine whether metformin alleviates airway inflammation and remodeling of experimental allergic asthma and elucidate the underlying mechanism. We sensitized and challenged mice with ovalbumin (OVA) to induce allergic asthma. During the challenge period, metformin was administered by intraperitoneal injection. By histopathological and immunohistochemical analyses, metformin-treated mice showed a significant alleviation in airway inflammation, and in the parameters of airway remodeling including goblet cell hyperplasia, collagen deposition and airway smooth muscle hypertrophy compared to those in the OVA-challenged mice. We also observed elevated levels of multiple cytokines (IL-4, IL-5, IL-13, TNF-α, TGF- β 1 and MMP-9) in the bronchoalveolar lavage fluid, OVA-specific IgE in the serum and angiogenesis-related factors (VEGF, SDF-1 and CXCR4) in the plasma from asthmatic mice, while metformin reduced all these parameters. Additionally, the activity of 5′-adenosine monophosphate-activated protein kinase a (AMPK α) in the lungs from OVA-challenged mice was remarkably lower than control ones, while after metformin treatment, the ratio of p -AMPK α to AMPK α was upregulated and new blood vessels in the sub-epithelial area as evidenced by CD31 staining were effectively suppressed. These results indicate that metformin ameliorates airway inflammation and remodeling in an OVA-induced chronic asthmatic model and its protective role could be associated with the restoration of AMPK α activity and decreased asthma-related angiogenesis. [ABSTRACT FROM AUTHOR]

Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Objective: To survey the risk factors of asthma among the people aged over 14 years in China., Methods: Home visits for completing epidemiological questionnaires in accordance with stratified cluster random sampling survey were conducted in 8 provinces (cities) of China residents aged over 14 years from February 2010 to August 2011. Asthma was diagnosed based upon case history, clinical signs and lung function test. The SPSS 12.0 software was used for statistic analyses for the epidemiological status of asthma., Results: Sampling population was composed of 180 099 subjects. Among 164 215 valid questionnaires, there were 79 692 males and 84 523 females, 2 034 had asthma. The overall prevalence rate was 1.2% (2 034/164 215). Correlation analyses showed that the risk factors were smoking (OR = 1.697, 95%CI: 1.547-1.861), breast feeding (OR = 0.801, 95%CI: 0.670-0.959), genetics (OR & 95%CI >1, asthma (OR = 10.440, 95%CI: 8.991-12.112)), complications (OR & 95%CI >1), body mass index (compared with normal weight, overweight (OR = 1.360, 95%CI: 1.212-1.531), obesity (OR = 10.631, 95%CI: 9.570-11.801)) and petting (OR & 95%CI >1)., Conclusion: Among Chinese asthmatics aged over 14, their risk factors include host (genetics & obesity) and environmental (smoking, breastfeeding, complications & pets) factors.

Objective: To describe the self-expanding endobronchial occluder, as utilized in bronchoscopic lung volume reduction, with a 36 month follow-up procedure., Methods: Twenty-three subjects with severe emphysema were recruited and underwent flexible bronchoscopic placement of self-expanding endobronchial occluders. Outcomes were assessed at 1 week, 1-month, 3-, 6-, 12-, 24-, and 36-month intervals. Feasibility, safety, and efficacy were analyzed by means of pulmonary function testing, 6-min walk test, dyspnea score, BODE (body mass index, air-flow obstruction, dyspnea, and exercise capacity) index, and St George's Respiratory Questionnaire., Results: Fifty-eight self-expanding endobronchial occluders were implanted into 23 lobes previously selected. No displacement was found during the follow-up. Five subjects experienced postoperative complications of cough, and 6 subjects had lobar pneumonia, which were not located in any of the blocked segments. The FEV1 in 18 subjects was improved by > 15%, compared with baselines (P < .001), and the mean first efficacy time and maximal efficacy time were 5.65 ± 1.51 months and 6.35 ± 3.08 months, respectively. No significant changes were observed in FVC or the ratio of residual volume to TLC. The 6-min walk distance, dyspnea score, and St George's Respiratory Questionnaire total score were improved in 22 subjects over a 24-month period, and a minority of subjects continued to improve through to the end of the study. Mean baseline BODE index had improved during follow-up, but not at the study's conclusion., Conclusions: This preliminary study demonstrates early significant improvements in pulmonary function, 6-min walk distance, dyspnea score, BODE index, and quality of life after placement of the self-expanding endobronchial occluder in bronchoscopic lung volume reduction. Its placement also proved both easy and safe. However, the initial improvements were maintained long-term for only a minority of subjects.