18 research outputs found

    Traffic-related air pollution and respiratory symptoms among asthmatic children, resident in Mexico City: the EVA cohort study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Taffic-related air pollution has been related to adverse respiratory outcomes; however, there is still uncertainty concerning the type of vehicle emission causing most deleterious effects.</p> <p>Methods</p> <p>A panel study was conducted among 147 asthmatic and 50 healthy children, who were followed up for an average of 22 weeks. Incidence density of coughing, wheezing and breathing difficulty was assessed by referring to daily records of symptoms and child's medication. The association between exposure to pollutants and occurrence of symptoms was evaluated using mixed-effect models with binary response and poisson regression.</p> <p>Results</p> <p>Wheezing was found to relate significantly to air pollutants: an increase of 17.4 μg/m<sup>3 </sup>(IQR) of PM<sub>2.5 </sub>(24-h average) was associated with an 8.8% increase (95% CI: 2.4% to 15.5%); an increase of 34 ppb (IQR) of NO<sub>2 </sub>(1-h maximum) was associated with an 9.1% increase (95% CI: 2.3% to16.4%) and an increase of 48 ppb (IQR) in O<sub>3 </sub>levels (1 hr maximum) to an increase of 10% (95% CI: 3.2% to 17.3%). Diesel-fueled motor vehicles were significantly associated with wheezing and bronchodilator use (IRR = 1.29; 95% CI: 1.03 to 1.62, and IRR = 1.32; 95% CI: 0.99 to 1.77, respectively, for an increase of 130 vehicles hourly, above the 24-hour average).</p> <p>Conclusion</p> <p>Respiratory symptoms in asthmatic children were significantly associated with exposure to traffic exhaust, especially from natural gas and diesel-fueled vehicles.</p

    Activated MCTC mast cells infiltrate diseased lung areas in cystic fibrosis and idiopathic pulmonary fibrosis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Although mast cells are regarded as important regulators of inflammation and tissue remodelling, their role in cystic fibrosis (CF) and idiopathic pulmonary fibrosis (IPF) has remained less studied. This study investigates the densities and phenotypes of mast cell populations in multiple lung compartments from patients with CF, IPF and never smoking controls.</p> <p>Methods</p> <p>Small airways, pulmonary vessels, and lung parenchyma were subjected to detailed immunohistochemical analyses using lungs from patients with CF (20 lung regions; 5 patients), IPF (21 regions; 7 patients) and controls (16 regions; 8 subjects). In each compartment the densities and distribution of MC<sub>T </sub>and MC<sub>TC </sub>mast cell populations were studied as well as the mast cell expression of IL-6 and TGF-β.</p> <p>Results</p> <p>In the alveolar parenchyma in lungs from patients with CF, MC<sub>TC </sub>numbers increased in areas showing cellular inflammation or fibrosis compared to controls. Apart from an altered balance between MC<sub>TC </sub>and MC<sub>T </sub>cells, mast cell in CF lungs showed elevated expression of IL-6. In CF, a decrease in total mast cell numbers was observed in small airways and pulmonary vessels. In patients with IPF, a significantly elevated MC<sub>TC </sub>density was present in fibrotic areas of the alveolar parenchyma with increased mast cell expression of TGF-β. The total mast cell density was unchanged in small airways and decreased in pulmonary vessels in IPF. Both the density, as well as the percentage, of MC<sub>TC </sub>correlated positively with the degree of fibrosis. The increased density of MC<sub>TC</sub>, as well as MC<sub>TC </sub>expression of TGF-β, correlated negatively with patient lung function.</p> <p>Conclusions</p> <p>The present study reveals that altered mast cell populations, with increased numbers of MC<sub>TC </sub>in diseased alveolar parenchyma, represents a significant component of the histopathology in CF and IPF. The mast cell alterations correlated to the degree of tissue remodelling and to lung function parameters. Further investigations of mast cells in these diseases may open for new therapeutic strategies.</p
    corecore