Experimental lung research
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Cyclical recruitment and derecruitment of lung parenchyma (R/D) remains a serious problem in ALI/ARDS patients, defined as atelectotrauma. Detection of cyclical R/D to titrate the optimal respiratory settings is of high clinical importance. ⋯ Continuous, ultrafast, on-line in vivo measurement of PaO₂ can be provided by an indwelling PaO₂ probe. In addition, monitoring of fast changes in SaO₂ by pulse oximetry technology at the bedside could also be used to detect those fast changes in oxygenation.
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The continuous exposure of the epithelial surface of the conducting airways to inhaled pathogens requires the presence of an efficient innate immune system to prevent infections. The innate immune system of the lung provides protection against a broad spectrum of microbial threats through a variety of effector mechanisms. The antimicrobial peptides and proteins form important elements of this defence system in the lung. ⋯ More recently, also active vitamin D(3) has been implicated as a major regulator of AMPs expression. AMPs contribute to host defence through direct antimicrobial activity, as well as by modulating innate and adaptive immunity, and wound repair. Novel insight into the mechanism of action of these peptides and the regulation of their expression may lead to innovative approaches for treatment of infectious and inflammatory lung disorders.
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Respiratory syncytial virus (RSV) bronchiolitis is a serious and distressing illness, which occurs almost exclusively in infants under one year of age. Although the majority of all children will have experienced an infection with RSV by the time they reach their second birthday, only a minority develop bronchiolitis. It is unclear why some otherwise healthy infants develop this severe illness and many studies have investigated whether or not this relates to an over-exuberant immunological response to the infection. It is increasingly being recognized that the innate immune response may play a key role.
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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.
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Review
A/J mouse as a model for lung tumorigenesis caused by tobacco smoke: strengths and weaknesses.
Strain A/J mice have successfully been used to develop an animal model for tobacco smoke carcinogenesis. In 18 individual studies, reported by 4 different laboratories, a significant increase in lung tumor multiplicities following exposure from 50 to 170mg/m3 of total suspended tobacco smoke particulates was found in 15 studies (83 %) and a significant increase in lung tumor incidence in 10 studies (56%). ⋯ From a toxicological standpoint, this indicates that cigarette smoke is a weak animal carcinogen. Although the assay allowed one to detect substantial chemopreventive activity of a mixture of myo-inositol and dexamethasone, it was less successful in showing efficacy for several other agents.