American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Aug 2016
Undiagnosed COPD Contributes to the Burden of Health Care Utilization: Data from the CanCOLD Study.
Chronic obstructive pulmonary disease (COPD) remains undiagnosed in many individuals with persistent airflow limitation. These individuals may be susceptible to exacerbation-like respiratory events that consume health care resources. ⋯ Most subjects with COPD in Canada remain undiagnosed. These subjects are less symptomatic and impaired, which may partly explain lack of diagnosis. Although patients with undiagnosed COPD experience fewer exacerbations than those with diagnosed COPD, they use a similar amount of health services for exacerbation events; thus, the overall health system burden of exacerbations in those with undiagnosed COPD is considerable.
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Adults born and raised at high altitudes have larger lung volumes and greater pulmonary diffusion capacity compared with adults at low altitude; however, it remains unclear whether the air and tissue volumes have comparable increases and whether there is a difference in airway size. ⋯ Our findings suggest that the adult lung did not increase lung volume later in life by expansion of an existing number of alveoli, but rather from increased alveolarization early in life. In addition, chronic hypoxia accentuates dysanaptic lung growth by increasing the lung parenchyma but not the airways.
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Am. J. Respir. Crit. Care Med. · Aug 2016
Syndecan-1 Attenuates Lung Injury During Influenza Infection By Potentiating c-Met Signaling to Suppress Epithelial Apoptosis.
Syndecan-1 is a cell surface heparan sulfate proteoglycan primarily expressed in the lung epithelium. Because the influenza virus is tropic to the airway epithelium, we investigated the role of syndecan-1 in influenza infection. ⋯ Our work shows that cell-associated syndecan-1 has an important role in regulating lung injury. Our findings demonstrate a novel mechanism in which cell membrane-associated syndecan-1 regulates the innate immune response to influenza infection by facilitating cytoprotective signals through c-Met signaling to limit bronchial epithelial apoptosis, thereby attenuating lung injury and inflammation.
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Am. J. Respir. Crit. Care Med. · Aug 2016
The Effect of Cigarette Smoking on Lung Function in Young Adults with Asthma.
Life-course persistent asthma and tobacco smoking are risk factors for irreversible airflow obstruction. It is often assumed that smoking and asthma have additive or multiplicative effects on the risk for airflow obstruction, but this has not been demonstrated in prospective studies of children with persistent asthma. ⋯ Childhood-onset persistent asthma is associated with airflow obstruction by mid-adult life, but this does not seem to be made worse by tobacco smoking. We found no evidence that smoking and childhood-persistent asthma have additive or multiplicative effects on airflow obstruction.