Resp Res
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Bacterial colonization and recurrent infections of the respiratory tract contribute to the progression of chronic obstructive pulmonary disease (COPD). There is evidence that exacerbations of COPD are provoked by new bacterial strains acquired from the environment. Using a murine model of colonization, we examined whether chronic exposure to cigarette smoke (CS) promotes nasopharyngeal colonization with typical lung pathogens and whether colonization is linked to inflammation in the respiratory tract. ⋯ These findings demonstrate that exposure to CS impacts the ability of the host to control bacterial colonization of the upper airways, resulting in enhanced inflammation and susceptibility of the host to pathogens migrating into the lung.
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Comparative Study
Prevalence of chronic obstructive pulmonary disease and variation in risk factors across four geographically diverse resource-limited settings in Peru.
It is unclear how geographic and social diversity affects the prevalence of chronic obstructive pulmonary disease (COPD). We sought to characterize the prevalence of COPD and identify risk factors across four settings in Peru with varying degrees of urbanization, altitude, and biomass fuel use. ⋯ The burden of COPD in Peru was not uniform and, unlike other settings, was not predominantly explained by tobacco smoking. This study emphasizes the role of biomass fuel use, and highlights pulmonary tuberculosis as an often neglected risk factor in endemic areas.
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It is incompletely understood how cigarette smoke (CS) exposure affects lung mucosal immune responses during viral respiratory infections. B cell activating factor belonging to the tumor necrosis factor family (BAFF) plays an important role in the induction of secretory immunoglobulin A (S-IgA) which is the main effector of the mucosal immune system. We therefore investigated the effects of CS exposure on BAFF expression and S-IgA responses in the lung during influenza virus infection. ⋯ Our findings indicate that CS may hinder early mucosal IgA responses in the lung during influenza virus infection through oxidative inhibition of BAFF, which might contribute to the increased incidence and severity of viral infections in smokers.
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Comparative Study
Capillary pCO2 helps distinguishing idiopathic pulmonary arterial hypertension from pulmonary hypertension due to heart failure with preserved ejection fraction.
The demographics of patients with idiopathic pulmonary arterial hypertension (IPAH) are changing and this diagnosis is increasingly being made in older patients. However, diagnostic misclassifications are common as it may be difficult to differentiate between IPAH and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF). We investigated the hypothesis that the capillary pCO2 (pcCO2) may help distinguishing between idiopathic pulmonary arterial hypertension (IPAH) and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF). ⋯ PcCO2 levels were significantly lower in IPAH compared to PH-HFpEF and may provide useful information in differentiating between both conditions.