The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Adenosine administration by inhalation elicits concentration-related bronchoconstriction in subjects with asthma and chronic obstructive pulmonary disease (COPD). The mechanisms of adenosine-induced bronchoconstriction appear to involve a selective interaction with activated mast cells with subsequent release of preformed and newly-formed mediators. ⋯ Promising adenosine-receptor targets for novel therapeutics of asthma and chronic obstructive pulmonary disease have recently been identified in a number of inflammatory cell types, including mast cells, eosinophils, lymphocytes, neutrophils, and macrophages. The recent characterisation of the A2B receptors indicates the human lung mast cell as one of the most strategic cellular targets.
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Volatile anaesthetics relax airway smooth muscle in vitro. The amount of relaxation might depend on the type and concentration of volatile anaesthetics, the calibre and precontraction level of the bronchi, and also on the species considered. These effects were investigated on isolated human bronchi. ⋯ In conclusion, halothane, isoflurane and desflurane exert direct but differential relaxant effects on human isolated bronchial smooth muscle. This may provide supplemental bronchodilation during anaesthesia. Although adenosine triphosphate-sensitive K+ channels are involved in these relaxant effects, they are unlikely to explain the observed differences between the three volatile anaesthetics.
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Randomized Controlled Trial Clinical Trial
Ambulatory oxygen improves quality of life of COPD patients: a randomised controlled study.
It is unknown whether acute response to ambulatory oxygen (O2) predicts longer term improvement in health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD) patients. The aims of this study were 1) to assess the short-term clinical impact, as determined by HRQL, of ambulatory O2 in a 12-week, double-blind, randomised crossover study of O2 (versus cylinder compressed air) of dyspnoeic but not chronically hypoxic COPD patients with exertional desaturation < or = 88% (n=41), and 2) to determine whether either baseline characteristics or acute response to O2 predicts short-term (12 weeks) response. Primary outcome measures were Chronic Respiratory Questionnaire (CRQ), Hospital Anxiety and Depression scale and the short form (SF)-36. ⋯ Short-term ambulatory oxygen is associated with significant improvements in health-related quality of life. These benefits cannot be predicted by baseline characteristics or acute response. Despite acute or short-term response, a substantial proportion of patients declined ambulatory oxygen.
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Infants who recover from respiratory syncytial virus (RSV)-induced bronchiolitis are at high risk of developing asthma and recurrent wheezing. It is not known whether severe RSV infection itself causes persistent effects or is a marker of a "wheezy" predisposition. To determine the long-term immunological correlates of infantile bronchiolitis, interleukin (IL)-4 and interferon (IFN)-gamma responses to a panel of antigens were studied in a well-characterised cohort of 7-8-yr-old children with a history of severe RSV bronchiolitis in infancy. ⋯ Other responses (including the IFN-gamma response to RSV) were equally strong in exbronchiolitics and controls. Respiratory syncytial virus infection primes memory T-cells that make interferon-gamma, but virus and aeroallergen-specific and interleukin-4 producing T-cells are also frequently primed in bronchiolitics. Respiratory syncytial virus bronchiolitis in infancy may increase the risk of allergic sensitisation by providing a local interleukin-4-rich environment, in which airborne allergens are first encountered.