American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · May 2011
Interferon-γ production by neutrophils during bacterial pneumonia in mice.
Neutrophils are usually the first circulating leukocytes to respond during bacterial pneumonia. Their expression of oxidants, proteases, and other mediators present in granules is well documented, but their ability to produce mediators through transcription and translation after migration to an inflammatory site has been appreciated only more recently. Interferon (IFN)-γ is a cytokine with many functions important in host defense and immunity. ⋯ S. pneumoniae and S. aureus, but not P. aeruginosa and E. coli, induce emigrated neutrophils to produce IFN-γ within 24 hours. Hck/Fgr/Lyn, Rac2, and NADPH oxidase are required for IFN-γ production. IFN-γ facilitates bacterial clearance at least in part through regulating formation of neutrophil extracellular traps. Differential expression by neutrophils of microRNAs that target the 3' untranslated region of the IFN-γ gene may contribute to the pathogen-specific regulation of translation.
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Am. J. Respir. Crit. Care Med. · May 2011
Asymmetric dimethylarginine contributes to airway nitric oxide deficiency in patients with cystic fibrosis.
Airway nitric oxide is reduced in cystic fibrosis airways. Asymmetric dimethylarginine is an endogenous nitric oxide synthase inhibitor that may contribute to nitric oxide deficiency in cystic fibrosis. ⋯ Asymmetric dimethylarginine is increased in cystic fibrosis airways and may contribute to airway obstruction in patients with cystic fibrosis by reducing nitric oxide formation.
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Am. J. Respir. Crit. Care Med. · May 2011
Lung stress and strain during mechanical ventilation: any safe threshold?
Unphysiologic strain (the ratio between tidal volume and functional residual capacity) and stress (the transpulmonary pressure) can cause ventilator-induced lung damage. ⋯ In healthy pigs, ventilator-induced lung damage develops only when a strain greater than 1.5-2 is reached or overcome. Because of differences in intrinsic lung properties, caution is warranted in translating these findings to humans.