Forced oscillation technique as a predictor of FEV1 improvement in asthma.

The usefulness of the forced oscillation technique (FOT) for predicting the treatment outcomes in untreated asthmatic patients is unknown. We investigated whether FOT could predict an improvement in FEV1 following treatment. FOT, spirometry, and fractional exhaled nitric oxide were performed in 31 outpatients before and after undergoing a minimum of two months combination therapy of inhaled corticosteroids and long-acting β2-agonists.

Association of the forced oscillation technique with negative expiratory pressure in COPD.

Expiratory flow limitation (EFL) during tidal breathing is common in patients with severe COPD, and a major determinant of dynamic hyperinflation and exercise limitation. The negative expiratory pressure (NEP) technique has been the gold standard to detect EFL, while the forced oscillation technique (FOT) has also been reported to detect it. However, the association of FOT with NEP is not fully understood.

Real-world effect of gastroesophageal reflux disease on cough-related quality of life and disease status in asthma and COPD.

Background: Gastroesophageal reflux disease (GERD) is one of the most common causes of chronic cough and often coexists with asthma or chronic obstructive pulmonary disease (COPD); however, it is unknown whether there are differences in the effect of GERD on these diseases. The purpose of this study was to assess the difference in the effect of GERD on cough-related quality of life and disease status in asthma and COPD in a real-world setting.

Methods: Subjects were 132 patients with overall controlled asthma and 102 patients with stable COPD.

Inspiratory resonant frequency of forced oscillation technique as a predictor of the composite physiologic index in interstitial lung disease.

The composite physiologic index (CPI), which is derived from FEV1, FVC, and diffusing capacity, has been developed to predict the extent of fibrosis on high-resolution computed tomography (HRCT). However, the relevance to the forced oscillation technique (FOT) is not fully understood. We hypothesized that FOT would independently predict the CPI in interstitial lung disease (ILD).

Predictors of expiratory flow limitation measured by forced oscillation technique in COPD.

Background: Expiratory flow limitation (EFL) during tidal breathing is common in patients with severe COPD, and a major determinant of dynamic hyperinflation and exercise limitation. EFL can be measured by the forced oscillation technique (FOT); however, the relevance to clinical parameters is not fully understood. We hypothesized that emphysema extent and pulmonary function would contribute independently to the degree of EFL.

Development of allergic bronchopulmonary aspergillosis with central bronchiectasis over a 10-year period: the need to recheck allergen sensitization.

A 55-year-old woman visited our hospital for an investigation of central bronchiectasis, mucoid impaction and infiltrative shadows on chest CT. She had a 10-year history of bronchial asthma; however, her adherence to treatment was poor. Based on the presence of peripheral blood eosinophilia and immediate cutaneous reactivity to Aspergillus fumigatus, the patient was clinically diagnosed with allergic bronchopulmonary aspergillosis.

Usefulness of Colored 3D Imaging of Respiratory Impedance in Asthma.

Purpose: Recently, the clinical application of the forced oscillation technique (FOT) has progressed with the spread of commercially available FOT devices, including the impulse oscillation system and MostGraph. We investigated the usefulness of color 3D imaging of respiratory impedance in asthma using MostGraph.

Methods: Whole-breath and within-breath respiratory system resistance (Rrs) and reactance (Xrs) were measured in 78 patients with asthma.

Predictors of phase III slope of nitrogen single-breath washout in COPD.

The nitrogen (N₂) single-breath washout (SBW) test is a measure of ventilation distribution inhomogeneity and also a small airway function that offers complementary information to spirometry; however, the relevance to the forced oscillation technique (FOT) and pulmonary emphysema in COPD is not fully understood. We hypothesized that pulmonary functions, forced oscillatory parameters, and emphysema extent would contribute independently to the results of the SBW test. In this cross-sectional study we assessed the relationship between the phase III slope (delta N₂) derived from N₂ SBW and these parameters.

Respiratory mechanics measured by forced oscillation technique in combined pulmonary fibrosis and emphysema.

The coexistence of emphysema and pulmonary fibrosis is known as combined pulmonary fibrosis and emphysema (CPFE). The aim of this study was to compare the lung mechanics measured by multi-frequency forced oscillation technique (FOT) among patients with CPFE, interstitial pneumonia (IP), and chronic obstructive pulmonary disease (COPD). FOT and pulmonary function tests were performed in 41 patients with CPFE, 47 with IP, and 86 with COPD.

Colored 3-dimensional analyses of respiratory resistance and reactance in COPD and asthma.

Background: The forced oscillation technique (FOT) is a noninvasive method with which to measure respiratory system resistance (Rrs) and reactance (Xrs) at a wide range of frequencies during breathing at rest in a short time. The purpose of this study was to assess the differences in Rrs and Xrs between patients with chronic obstructive pulmonary disease (COPD) and asthma using a new method of FOT with colored 3-dimensional visualization.

Methods: Fifty-one patients with stable COPD and 49 patients with controlled or partly controlled asthma were enrolled.

Decreased expression of antioxidant enzymes and increased expression of chemokines in COPD lung.

The involvement of inflammation in the pathogenesis of chronic obstructive pulmonary disease (COPD) has been investigated using samples from relatively central airways such as airway biopsies, but there have been fewer studies in the peripheral lung, which is thought to be the main site of the disease process. To determine the molecules that relate to the mechanisms underlying the pathogenesis of COPD, we evaluated the mRNA expression of inflammatory cytokines, chemokines, oxidant enzymes, antioxidant enzymes, proteinases and antiproteinases in peripheral lung tissues from 33 COPD and non-COPD subjects who were undergoing lung resection for lung cancer using an RT-PCR technique. Among the 42 studied candidate genes, the expressions of mRNA for catalase, glutathion S-transferase P1 (GSTP1), glutathion S-transferase M1 (GSTM1), microsomal epoxide hydrolase (mEPHX) and tissue inhibitor of metalloproteinase 2 (TIMP2) were significantly decreased in COPD lung tissues compared with those in non-COPD tissues, and most of these decreases were significantly correlated with the degree of airflow limitation.

Cytokine-mediated xanthine oxidase upregulation in chronic obstructive pulmonary disease's airways.

Reactive oxygen species have been reported to be involved in the airway inflammatory process of chronic obstructive pulmonary disease (COPD). The aim of this study was to quantify the activity of xanthine oxidase (XO), which generates a potent radical superoxide anion in COPD airways. Thirteen stable COPD patients and 10 healthy subjects participated in this study.

Quantitative assessment of protein-bound tyrosine nitration in airway secretions from patients with inflammatory airway disease.

Because reactive nitrogen species (RNS) have potent inflammatory activity, they may be involved in the inflammatory process in pulmonary diseases. We recently reported increased numbers of 3-nitrotyrosine immunopositive cells, which are evidences of RNS production, in the sputum of patients with chronic obstructive pulmonary disease (COPD) and patients with asthma compared with healthy subjects. In the present study, we attempted to quantify this protein nitration in the airways by means of high-performance liquid chromatography (HPLC) used together with an electrochemical detection system that we developed.