Lung
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Medical imaging is the largest contributor to per capita radiation dose in the United States. A majority of that medical imaging dose can be attributed to the increasing number of computed tomography (CT) procedures performed every year, at last count more than 62 million scans. As a result, increased attention to the possible risks of radiation exposure has entered the popular media and therefore the public at large. This review informs the medical practitioner on the nomenclature, dosimetry, and estimated risk of CT scan radiation exposure, thereby better allowing the clinician to address the risks/benefits of CT scanning and to answer questions concerning risk.
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The subepithelial fibrosis component of airway remodeling in asthma is mediated through induction of transforming growth factor-beta1 (TGF-beta1) expression with consequent activation of myofibroblasts to produce extracellular matrix proteins. The number of myofibroblasts is increased in the asthmatic airway and is significantly correlated with the thickness of lamina reticularis. However, much is still unknown regarding the origin of bronchial myofibroblasts. ⋯ Incubation of human bronchial epithelial cells with TGF-beta1 induced de novo expression of alpha-SMA, increased formation of stress fiber by F-actin reorganization, and loss of epithelial marker E-cadherin. Moreover, a significant increase in the levels of collagen I and endogenous TGF-beta1 released from bronchial epithelial cells stimulated with TGF-beta1 were observed. These results suggested that human bronchial epithelial cells, under stimulation of TGF-beta1, underwent transdifferentiation into myofibroblasts.
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Disturbed sleep is reportedly common in chronic obstructive pulmonary disease (COPD), but the impact of quality of sleep on health-related quality of life (HRQL) has not been previously investigated in these individuals. The purpose of this study was to assess the impact of quality of sleep on HRQL in patients with COPD. In 30 clinically stable patients with moderate to very severe COPD, we evaluated subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and HRQL using the Saint George's Respiratory Questionnaire. ⋯ Multiple regression analysis showed that quality of sleep was the best predictor of quality of life in our subjects. Our data suggest that quality of sleep is major determinant of HRQL in COPD. Increased efforts to diagnose and treat sleep problems, including measures to improve factors that adversely affect sleep should receive great attention in the daily management of these patients.
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Comparative Study
Chronic sleep complaints in premenopausal women and their association with sleep-disordered breathing.
In clinical practice, we have found that premenopausal women have delayed diagnosis of sleep-disordered breathing (SDB). ⋯ Normal-weight premenopausal SDB women often present with atypical sleep complaints of chronic insomnia and parasomnias. Clinical attention paid to craniofacial features and use of specific scales such as Mallampati help with the suspicion of the presence of SDB, and a low AHI is unrelated to the positive clinical impact of nasal CPAP treatment.
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Clinical Trial
Effects of nasal CPAP treatment on insulin resistance, lipid profile, and plasma leptin in sleep apnea.
Obstructive sleep apnea has been linked with metabolic syndrome characterized by dyslipidemia, dyscoagulation, hypertension, and diabetes mellitus type 2 and their cardiovascular consequences. This study was designed to determine the effects of 8 weeks of therapy with continuous positive airway pressure (CPAP) on insulin resistance, glucose, and lipid profile, and the relationship between leptin and insulin-resistance parameters in patients with moderate-to-severe obstructive sleep apnea. ⋯ In patients with moderate-to-severe obstructive sleep apnea, compliant CPAP usage may improve insulin secretion capacity, reduce leptin, total cholesterol, and low-density lipoprotein levels. Leptin showed significant relationship with insulin resistance, and this relationship remained after 8 weeks of CPAP therapy.