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Concept: Lung


Background The prevalence of pulmonary embolism among patients hospitalized for syncope is not well documented, and current guidelines pay little attention to a diagnostic workup for pulmonary embolism in these patients. Methods We performed a systematic workup for pulmonary embolism in patients admitted to 11 hospitals in Italy for a first episode of syncope, regardless of whether there were alternative explanations for the syncope. The diagnosis of pulmonary embolism was ruled out in patients who had a low pretest clinical probability, which was defined according to the Wells score, in combination with a negative d-dimer assay. In all other patients, computed tomographic pulmonary angiography or ventilation-perfusion lung scanning was performed. Results A total of 560 patients (mean age, 76 years) were included in the study. A diagnosis of pulmonary embolism was ruled out in 330 of the 560 patients (58.9%) on the basis of the combination of a low pretest clinical probability of pulmonary embolism and negative d-dimer assay. Among the remaining 230 patients, pulmonary embolism was identified in 97 (42.2%). In the entire cohort, the prevalence of pulmonary embolism was 17.3% (95% confidence interval, 14.2 to 20.5). Evidence of an embolus in a main pulmonary or lobar artery or evidence of perfusion defects larger than 25% of the total area of both lungs was found in 61 patients. Pulmonary embolism was identified in 45 of the 355 patients (12.7%) who had an alternative explanation for syncope and in 52 of the 205 patients (25.4%) who did not. Conclusions Pulmonary embolism was identified in nearly one of every six patients hospitalized for a first episode of syncope. (Funded by the University of Padua; PESIT number, NCT01797289 .).

Concepts: Clinical trial, Lung, Hospital, Heart, Pulmonary embolism, Pulmonary artery, Human lung, Embolism


Over 100 million women use progesterone therapies worldwide. Despite having immunomodulatory and repair properties, their effects on the outcome of viral diseases outside of the reproductive tract have not been evaluated. Administration of exogenous progesterone (at concentrations that mimic the luteal phase) to progesterone-depleted adult female mice conferred protection from both lethal and sublethal influenza A virus (IAV) infection. Progesterone treatment altered the inflammatory environment of the lungs, but had no effects on viral load. Progesterone treatment promoted faster recovery by increasing TGF-β, IL-6, IL-22, numbers of regulatory Th17 cells expressing CD39, and cellular proliferation, reducing protein leakage into the airway, improving pulmonary function, and upregulating the epidermal growth factor amphiregulin (AREG) in the lungs. Administration of rAREG to progesterone-depleted females promoted pulmonary repair and improved the outcome of IAV infection. Progesterone-treatment of AREG-deficient females could not restore protection, indicating that progesterone-mediated induction of AREG caused repair in the lungs and accelerated recovery from IAV infection. Repair and production of AREG by damaged respiratory epithelial cell cultures in vitro was increased by progesterone. Our results illustrate that progesterone is a critical host factor mediating production of AREG by epithelial cells and pulmonary tissue repair following infection, which has important implications for women’s health.

Concepts: Reproduction, Lung, Pneumonia, Epidermal growth factor, Epithelium, Skin, Cervix, Influenzavirus A


Asthma is one of the most common chronic diseases in childhood. According to guidelines, a diagnosis of asthma should be confirmed using lung function testing in children aged >6 years. Previous studies indicate that asthma in children is probably overdiagnosed. However, the extent has not previously been assessed.

Concepts: Medicine, Asthma, Lung, Medical terms, Retrospective, Chronic


Background Bronchoscopy is frequently nondiagnostic in patients with pulmonary lesions suspected to be lung cancer. This often results in additional invasive testing, although many lesions are benign. We sought to validate a bronchial-airway gene-expression classifier that could improve the diagnostic performance of bronchoscopy. Methods Current or former smokers undergoing bronchoscopy for suspected lung cancer were enrolled at 28 centers in two multicenter prospective studies (AEGIS-1 and AEGIS-2). A gene-expression classifier was measured in epithelial cells collected from the normal-appearing mainstem bronchus to assess the probability of lung cancer. Results A total of 639 patients in AEGIS-1 (298 patients) and AEGIS-2 (341 patients) met the criteria for inclusion. A total of 43% of bronchoscopic examinations were nondiagnostic for lung cancer, and invasive procedures were performed after bronchoscopy in 35% of patients with benign lesions. In AEGIS-1, the classifier had an area under the receiver-operating-characteristic curve (AUC) of 0.78 (95% confidence interval [CI], 0.73 to 0.83), a sensitivity of 88% (95% CI, 83 to 92), and a specificity of 47% (95% CI, 37 to 58). In AEGIS-2, the classifier had an AUC of 0.74 (95% CI, 0.68 to 0.80), a sensitivity of 89% (95% CI, 84 to 92), and a specificity of 47% (95% CI, 36 to 59). The combination of the classifier plus bronchoscopy had a sensitivity of 96% (95% CI, 93 to 98) in AEGIS-1 and 98% (95% CI, 96 to 99) in AEGIS-2, independent of lesion size and location. In 101 patients with an intermediate pretest probability of cancer, the negative predictive value of the classifier was 91% (95% CI, 75 to 98) among patients with a nondiagnostic bronchoscopic examination. Conclusions The gene-expression classifier improved the diagnostic performance of bronchoscopy for the detection of lung cancer. In intermediate-risk patients with a nondiagnostic bronchoscopic examination, a negative classifier score provides support for a more conservative diagnostic approach. (Funded by Allegro Diagnostics and others; AEGIS-1 and AEGIS-2 numbers, NCT01309087 and NCT00746759 .).

Concepts: Pulmonology, Lung, Lung cancer, Positive predictive value, Negative predictive value, Sensitivity and specificity, Carcinoma, Lesion


Although electronic cigarettes (ECs) are a much less harmful alternative to tobacco cigarettes, there is concern as to whether long-term ECs use may cause risks to human health. We report health outcomes (blood pressure, heart rate, body weight, lung function, respiratory symptoms, exhaled breath nitric oxide [eNO], exhaled carbon monoxide [eCO], and high-resolution computed tomography [HRCT] of the lungs) from a prospective 3.5-year observational study of a cohort of nine daily EC users (mean age 29.7 (±6.1) years) who have never smoked and a reference group of twelve never smokers. No significant changes could be detected over the observation period from baseline in the EC users or between EC users and control subjects in any of the health outcomes investigated. Moreover, no pathological findings could be identified on HRCT of the lungs and no respiratory symptoms were consistently reported in the EC user group. Although it cannot be excluded that some harm may occur at later stages, this study did not demonstrate any health concerns associated with long-term use of EC in relatively young users who did not also smoke tobacco.

Concepts: Scientific method, Oxygen, Lung, Tobacco, Tobacco smoking, Cigarette, Nicotine, Electronic cigarette


The evolution of new and reemerging historic virulent strains of respiratory viruses from animal reservoirs is a significant threat to human health. Inefficient human-to-human transmission of zoonotic strains may initially limit the spread of transmission, but an infection may be contracted by touching contaminated surfaces. Enveloped viruses are often susceptible to environmental stresses, but the human coronaviruses responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) have recently caused increasing concern of contact transmission during outbreaks. We report here that pathogenic human coronavirus 229E remained infectious in a human lung cell culture model following at least 5 days of persistence on a range of common nonbiocidal surface materials, including polytetrafluoroethylene (Teflon; PTFE), polyvinyl chloride (PVC), ceramic tiles, glass, silicone rubber, and stainless steel. We have shown previously that noroviruses are destroyed on copper alloy surfaces. In this new study, human coronavirus 229E was rapidly inactivated on a range of copper alloys (within a few minutes for simulated fingertip contamination) and Cu/Zn brasses were very effective at lower copper concentration. Exposure to copper destroyed the viral genomes and irreversibly affected virus morphology, including disintegration of envelope and dispersal of surface spikes. Cu(I) and Cu(II) moieties were responsible for the inactivation, which was enhanced by reactive oxygen species generation on alloy surfaces, resulting in even faster inactivation than was seen with nonenveloped viruses on copper. Consequently, copper alloy surfaces could be employed in communal areas and at any mass gatherings to help reduce transmission of respiratory viruses from contaminated surfaces and protect the public health.

Concepts: Lung, Virus, Severe acute respiratory syndrome, Virology, Bronze, Brass, Polyvinyl chloride, Polytetrafluoroethylene


Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity and mortality. It remains unknown which aspect of lung function carries the most prognostic information and if simple spirometry is sufficient.Survival was assessed in COPD outpatients whose data had been added prospectively to a clinical audit database from the point of first full lung function testing including spirometry, lung volumes, carbon monoxide diffusion capacity and arterial blood gases. Variables univariately associated with survival were entered into a multivariate Cox proportional hazard model.604 patients were included (mean age 61.9±9.7 years, forced expiratory volume in 1 second 37±18.1%predicted, 62.9% males); 229(37.9%) died during a median follow-up of 83 months. Median survival was 91.9(80.8-103) months with survival rates at 3 and 5 years 0.83 and 0.66, respectively. Carbon monoxide diffusion capacity %predicted quartiles [(best quartile (>51%): HR=: 0.33; 95% CI: 0.96-0. and second quartile (51-37.3%): HR=0.52, versus lowest quartile (<27.9%))], age (HR=:1.04; 95% CI:1.02-1.06) and arterial oxygen partial pressure (HR=: 0.85;95% CI:0.77-0.94) were the only parameters independently associated with mortality.Measurement of diffusion capacity provides additional prognostic information compared to spirometry in patients under hospital follow-up and could be considered routinely.

Concepts: Oxygen, Pulmonology, Asthma, Lung, Respiratory physiology, Chronic obstructive pulmonary disease, Spirometry, Respiratory therapy


End-stage lung disease is the third leading cause of death worldwide, accounting for 400,000 deaths per year in the United States alone. To reduce the morbidity and mortality associated with lung disease, new therapeutic strategies aimed at promoting lung repair and increasing the number of donor lungs available for transplantation are being explored. Because of the extreme complexity of this organ, previous attempts at bioengineering functional lungs from fully decellularized or synthetic scaffolds lacking functional vasculature have been largely unsuccessful. An intact vascular network is critical not only for maintaining the blood-gas barrier and allowing for proper graft function but also for supporting the regenerative cells. We therefore developed an airway-specific approach to removing the pulmonary epithelium, while maintaining the viability and function of the vascular endothelium, using a rat model. The resulting vascularized lung grafts supported the attachment and growth of human adult pulmonary cells and stem cell-derived lung-specified epithelial cells. We propose that de-epithelialization of the lung with preservation of intact vasculature could facilitate cell therapy of pulmonary epithelium and enable bioengineering of functional lungs for transplantation.

Concepts: Death, Pulmonology, Lung, Mortality rate, Heart, Epithelium, Endothelium, Cornea


Idiopathic pulmonary fibrosis (IPF) is a lethal interstitial lung disease characterized by airway remodeling, inflammation, alveolar destruction, and fibrosis. We utilized single-cell RNA sequencing (scRNA-seq) to identify epithelial cell types and associated biological processes involved in the pathogenesis of IPF. Transcriptomic analysis of normal human lung epithelial cells defined gene expression patterns associated with highly differentiated alveolar type 2 (AT2) cells, indicated by enrichment of RNAs critical for surfactant homeostasis. In contrast, scRNA-seq of IPF cells identified 3 distinct subsets of epithelial cell types with characteristics of conducting airway basal and goblet cells and an additional atypical transitional cell that contributes to pathological processes in IPF. Individual IPF cells frequently coexpressed alveolar type 1 (AT1), AT2, and conducting airway selective markers, demonstrating “indeterminate” states of differentiation not seen in normal lung development. Pathway analysis predicted aberrant activation of canonical signaling via TGF-β, HIPPO/YAP, P53, WNT, and AKT/PI3K. Immunofluorescence confocal microscopy identified the disruption of alveolar structure and loss of the normal proximal-peripheral differentiation of pulmonary epithelial cells. scRNA-seq analyses identified loss of normal epithelial cell identities and unique contributions of epithelial cells to the pathogenesis of IPF. The present study provides a rich data source to further explore lung health and disease.

Concepts: DNA, Gene, Gene expression, Molecular biology, Lung, Epithelium, Basement membrane, Idiopathic pulmonary fibrosis


Pirfenidone is a novel anti-fibrotic and anti-inflammatory agent that inhibits the progression of fibrosis in animal models and in patients with idiopathic pulmonary fibrosis (IPF). We previously showed that pirfenidone inhibits the over-expression of collagen type I and of heat shock protein (HSP) 47, a collagen-specific molecular chaperone, in human lung fibroblasts stimulated with transforming growth factor (TGF)-β1 in vitro. The increased numbers of HSP47-positive type II pneumocytes as well as fibroblasts were also diminished by pirfenidone in an animal model of pulmonary fibrosis induced by bleomycin. The present study evaluates the effects of pirfenidone on collagen type I and HSP47 expression in the human alveolar epithelial cell line, A549 cells in vitro.

Concepts: Protein, Cell, Lung, Collagen, Fibrosis, Chaperone, Idiopathic pulmonary fibrosis, Heat shock protein