Experimental lung research
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Tissue inhibitor of metalloproteinase-3 (TIMP3) null mice develop emphysema-like airspace enlargement due to an enzymatic imbalance. This study investigates how these abnormalities alter lung mechanics and the response to 2 different mechanical ventilation strategies. ⋯ Decreased compliance and increased resistance were observed following the injurious ventilation strategy; however, the TIMP3 null response to both ventilation strategies was similar to wild-type mice. In conclusion, TIMP3 null mice have significant alterations in lung mechanics; however, this does not affect their response to ventilation.
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The authors have previously shown that mechanical ventilation can result in increased pulmonary inflammation and suppressed peripheral leukocyte function. In the present study the effect of surfactant therapy on pulmonary inflammation and peripheral immune function in ventilated surfactant-deficient rats was assessed. Surfactant deficiency was induced by repeated lung lavage, treated rats with surfactant or left them untreated, and ventilated the rats during 2 hours. ⋯ In conclusion, 2 hours of mechanical ventilation resulted in increased lung inflammation and partial peripheral leukocyte suppression in surfactant-deficient rats. Surfactant therapy ameliorated lung function but could not prevent or restore peripheral immunosuppression. The authors postulate that peripheral immunosuppression may occur in ventilated surfactant deficient patients, which may enhance susceptibility for infections.
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Alveolar cells were evaluated in BALB/c mice exposed to smoke from 9 cigarettes per day. The mice were sacrificed at 1, 5, and 10 days and examined by lung morphometry and immunohistochemical staining of alveolar macrophages for tumor necrosis factor (TNF)-alpha, matrix metalloproteinase (MMP)-12, and tissue inhibitor of metalloproteinase (TIMP)-2. ⋯ The number of AMs with TNF-alpha and TIMP-2 labeling was higher at 5 days but decreased at 10 days. Short-term CS exposure induced pulmonary inflammation with major participation of MMP-12-positive AMs.
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Half of the elderly persons with asthma have not been diagnosed, yet their quality of life is substantially lower than others their age. Primary care physicians should, therefore, be encouraged to ask about respiratory symptoms in elderly patients and then perform office spirometry for those with symptoms. ⋯ When spirometry shows airway obstruction post-bronchodilator, a normal diffusing capacity (DLCO) test will rule out COPD in current and former smokers. A normal chest X-ray and B-type natriuretic peptide (BNP) will rule out congestive heart failure (CHF) in those with dyspnea.