American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Aug 2014
Pseudomonas aeruginosa in vitro Phenotypes Distinguish Cystic Fibrosis Infection Stages and Outcomes.
Pseudomonas aeruginosa undergoes phenotypic changes during cystic fibrosis (CF) lung infection. Although mucoidy is traditionally associated with transition to chronic infection, we hypothesized that additional in vitro phenotypes correlate with this transition and contribute to disease. ⋯ In this large epidemiologic study of CF P. aeruginosa adaptation, P. aeruginosa isolates exhibited two in vitro phenotypes that best distinguished early and later infection stages. Among the many phenotypes tested, mucoidy and reduced twitching best predicted subsequent PE. These phenotypes indicate potentially useful prognostic markers of transition to chronic infection and advancing lung disease.
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Am. J. Respir. Crit. Care Med. · Aug 2014
Nocturnal Asthma and the Importance of Race-ethnicity and Genetic Ancestry.
Nocturnal asthma is a common presentation and is associated with a more severe form of the disease. However, there are few epidemiologic studies of nocturnal asthma, particularly in minority populations. ⋯ Both self-identified race/ethnicity and African ancestry appear to be independent predictors of nocturnal asthma. The mechanism by which genetic ancestry contributes to population-level differences in nocturnal asthma appears to be largely independent of lung function.
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Am. J. Respir. Crit. Care Med. · Aug 2014
The Natural History of Lung Function Following Lung Transplantation for Alpha-1 Antitrypsin Deficiency.
Lung transplantation (LT) is an established treatment for end-stage lung diseases, including chronic obstructive pulmonary disease (COPD) associated with α1-antitrypsin deficiency (AATD). ⋯ Although overall the post-LT FEV1 slope, severity of ACR, and survival among patients with AATD is similar to that of AAT-replete patients with COPD, patients with AATD with double LT have a faster rate of FEV1 decline. These findings support the eligibility of patients with AATD for LT, and suggest the need for additional studies to better understand the difference between single and double LT in AATD.
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Am. J. Respir. Crit. Care Med. · Aug 2014
READING PULMONARY VASCULAR PRESSURE TRACINGS How to handle the problems of zero leveling and respiratory swings.
The accuracy of pulmonary vascular pressure measurements is of great diagnostic and prognostic relevance. However, there is variability of zero leveling procedures, and the current recommendation of end-expiratory reading may not always be adequate. A review of physiological and anatomical data, supported by recent imaging, leads to the practical recommendation of zero leveling at the cross-section of three transthoracic planes, which are, respectively midchest frontal, transverse through the fourth intercostal space, and midsagittal. ⋯ This problem is amplified in patients with obstructed airways. With the exception of dynamic hyperinflation states, it is reasonable to assume that negative inspiratory and positive expiratory intrathoracic pressures cancel each other out, so averaging pulmonary vascular pressures over several respiratory cycles is most often preferable. This recommendation may be generalized for the purpose of consistency and makes sense, as pulmonary blood flow measurements are not corrected for phasic inspiratory and expiratory changes in clinical practice.