Lung
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Although the relative effect of racemic and (R)-albuterol on airway smooth muscle tone have been investigated in patients with airflow obstruction, the comparative effectiveness of these drugs in relaxing airway vascular smooth muscle is unknown. Therefore, we determined the actions of inhaled racemic and (R)-albuterol on airway mucosal blood flow (Qaw) normalized for anatomic dead space as an index of airway vascular smooth muscle tone in 11 healthy subjects and 10 subjects with mild asthma. We also monitored the forced expiratory volume in 1 second (FEV1) as an index of airway smooth muscle tone. ⋯ Racemic and (R)-albuterol caused a transient, dose-dependent increase of Qaw in healthy, but not in asthmatic subjects; the responses were not different between the two drugs. The FEV1 tended to increase more in asthmatics than in healthy subjects, again without a difference between the two drugs. These results show that racemic and (R)-albuterol have comparable effects on airway vascular smooth muscle and suggest that the blunted airway vascular smooth muscle response to albuterol in asthmatics is not related to (S)-albuterol.
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High-resolution computed tomography (HRCT) is a useful method for quantifying the extent of emphysema. Few reports have mentioned the relationships between HRCT scans and pulmonary function tests in chronic obstructive pulmonary disease (COPD). For diagnosis, COPD requires chronic airflow limitation and emphysema and/or chronic bronchitis. ⋯ The middle left part of the lung during expiration correlated statistically significant with MVV (r = -0.673, p = 0.001), FVC (r = -0.493, p = 0.027), FEV1 (r = -0.629, p = 0.003), resistance (r = 0.593,p = 0.005), RV (r = 0.601, p = 0.005), TLC (r = 0.546, p = 0.012), FRC (r = 0.594, p = 0.006) and peak VO2 (r = -0.525, p = 0.015). Forced expiratory volume in 1 sec (FEV1), which is a well-established measure of airflow obstruction, correlated with the HRCT grade (1) in the middle left part of the lung during inspiration (r = -0.468, p = 0.035) and during expiration (r = - 0.629, p = 0.003) (2) in the lower right lung during inspiration (r = -0.567, p = 0.007) and during expiration (r = -0.558, p = 0.008) (3) in the lower left lung during inspiration (r = -0.542, p = 0.011) and during expiration (r = -0.558, p = 0.008) (4) in the upper right lung during expiration (r = -0.469, p = 0.037) (5) in the upper left lung during expiration (r = -0.463, p = 0.035) and (6) in the middle right lung during expiration (r = -0.632, p = 0.002). According to our results HRCT was a valuable tool for evaluating the severity of COPD--especially the middle right and left part of the lungs, during expiration--and correlated well with pulmonary function tests.
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This study evaluated the effects of fluticasone propionate inhalation therapy on lung ventilation and alveolar permeability by quantitative Tc-99m DTPA radioaerosol inhalation lung scintigraphy in 15 children with asthma. Lung ventilation was evaluated as the distribution percentage (D%) of Tc-99m DTPA radioaerosols in the central, intermediate and peripheral regions of the right lung. ⋯ The preliminary results revealed statistically significantly improved lung ventilation but no significant change of alveolar permeability in the right lung after one-week fluticasone propionate inhalation therapy in children with asthma. We suggest that the widely available and noninvasive Tc-99m DTPA radioaerosol inhalation lung scintigraphy can simultaneously evaluate lung ventilation and alveolar permeability in one study and should contribute to any disorder involving both alveoli and airways.
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We used technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan to detect subclinical lung injury in patients with chronic renal failure (CRF), on regular hemodialysis (HD), who had normal chest X-ray findings (CXR) and pulmonary function test (PFT). The degree of pulmonary vascular endothelium damage was represented as lung/liver uptake ratios (L/L ratios) calculated by Tc-99m HMPAO lung scan. The L/L ratios of the 20 male CRF patients on HD with normal CXR and PFT were compared with those of the 20 male normal controls. ⋯ Using a cut-off value of 0.50, 18/20 [90%] CRF patients had abnormally increased L/L ratios. Our findings concluded that the pulmonary vascular endothelium damage represented as significantly increased L/L ratios on Tc-99m HMPAO lung scan in CRF patients on HD with normal CXR and PFT. In addition, Tc-99m HMPAO lung scan has the potential to be a sensitive, objective and noninvasive method to detect subclinical lung injury of CRF patients on HD, which is different from the traditional studies such as CXR or PFT.
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Randomized Controlled Trial Comparative Study Clinical Trial
Controlled trial of inhaled fluticasone propionate in moderate to severe COPD.
Inhaled corticosteroids are often used in the treatment of stable chronic obstructive pulmonary disease (COPD), however, studies of these agents have had mixed results. Previous trials have often excluded subjects with bronchodilator response, have failed to evaluate effect on gas exchange, and have usually looked at only post- rather than prebronchodilator forced expiratory volume (FEV). Our objective was to better assess the efficacy of topical corticosteroids in the treatment of COPD. ⋯ A trend towards fewer exacerbations with fluticasone did not quite meet statistical significance (p = 0.11). Inhaled fluticasone over 3 months improved prebronchodilator airflow obstruction and oxygenation while decreasing dyspnea in moderate to severe COPD. Postbronchodilator FEV1 was not significantly changed.