Phenotype classification using the combination of lung sound analysis and fractional exhaled nitric oxide for evaluating asthma treatment

Background

We report the utility of combining lung sound analysis and fractional exhaled nitric oxide (FeNO) for phenotype classification of airway inflammation in patients with bronchial asthma.We investigated the usefulness of the combination of the expiration-to-inspiration sound power ratio in the mid-frequency range (E/I MF) of 200–400 Hz and FeNO for comprehensively classifying disease type and evaluating asthma treatment.

Respiratory function in healthy ever-smokers is impaired by smoking habits in a dose-dependent manner

Background

There is limited information about the respiratory function of ever-smokers without lung disorders. We sought to assess the effects of smoking habits on respiratory function in subjects without lung disorders.

‘Normal’ lung function in rural Australian Aborigines*

Abstract Background: Although lung diseases are a leading cause of premature mortality in Australian Aborigines, little is known about normal lung function in these people. Aim: To develop models for ‘normal’ spirometric function in rural Australian Aborigines. Method: A cross-sectional population-based study of four rural Aboriginal communities was performed in Queensland, Northern Territory and South Australia, Australia. We studied 261 children aged seven-19 years and 332 adults aged 20–80 years who were free of symptoms and had no clinical signs of chronic lung disease. The outcome measures were forced expiratory volume in one second (FEVj) and forced vital capacity (FVC). Multiple linear regression was used to develop models for FEVj and FVC and comparisons were made with Caucasians and indigenous people from other countries. Results: The Aboriginal people studied had FEVi and FVC values that were lower (20% and 30% respectively) than those found in Caucasians of the same height, age and gender. As a consequence, they had relatively high FEVi/FVC ratios. Those studied also had forced expiratory volumes that were lower than those found in African Americans and other indigenous peoples. Conclusions: Apparently healthy rural Aboriginal people have low forced expiratory volumes when contrasted with Caucasians and indigenous peoples such as African Americans. More research is required to determine if this is ‘normal’ or a product of the suboptimal environment into which many Aboriginal people are born.     

Altered Th1/Th2 commitment contributes to lung senescence in CXCR3-deficient mice

Aging is an inevitable process associated with immune imbalance, which is characterized by a progressive functional decline in major organs, including lung. However, effects of altered Th1/Th2 commitment on lung senescence are largely unknown. To examine effects of altered Th1/Th2 balance on lung aging, we measured proportions of Th1 and Th2 cells and expression of cytokines, chemokines, collagen deposition and other relevant physiological and pathological parameters in 2- and 20-months-old (mo) CXCR3-deficient (CXCR3^−/−) C57BL/6J mice compared with wild-type (WT) mice. There was a significant weight-loss observed in 20-mo CXCR3^−/− mice compared with the same aged WT group. Although lung function and structure changed with age in both groups, central airway resistance (Rn), tissue elastance (H) and damping (G) were significantly lower in 20-mo CXCR3^−/− mice than those of WT mice. In contrast, the whole lung volume (V_L), the mean linear intercept length of alveolar (L_m), and the total lung collagen content were significantly elevated in 20-mo CXCR3^−/− mice. With aging, the lungs of WT mice had typical Th1-type status (increased population of Th1 cells and concentrations of cytokine IFN-γ and CXCR3 ligands) while CXCR3^−/− mice showed Th2-type polarization (decreased proportion of Th1 cells and concentrations of CXCR3 ligands but increased level of IL-4). Our data suggest that Immunosenescence is associated with lung aging, and that altered Th1/Th2 imbalance favors Th2 predominance in CXCR3^−/− mice, which contributes to the process of accelerated lung aging in this model.     

Temporal profile of forced expiratory lung function in allergen-challenged Brown-Norway rats

The Brown–Norway rat is often used to study the allergic pulmonary response. However, relatively little is known about the delayed phase reactions after allergen challenge in this species. To evaluate the temporal changes in lung function and elucidate the mechanisms involved in the delayed phase response, Brown–Norway rats were sensitized and challenged to aerosolized ovalbumin and lung functions were measured by forced expiratory maneuvers and forced oscillation for up to 10 days after a single antigen challenge. Statistically significant (P < 0.05) reductions in inspiratory capacity, forced vital capacity, functional residual capacity, peak expiratory flow and maximum mid-expiratory flow and increases in respiratory system resistance and elastance were seen by 1 to 3 days after ovalbumin challenge that returned to baseline by 10 days. The reductions in lung function after ovalbumin challenge were blocked by the corticosteroid, betamethasone (1 mg/kg, p.o.). Histological evaluation of lung tissue of sensitized rats demonstrated evidence of interstitial pulmonary edema, an increase in tissue eosinophils and an increase in Periodic Acid Schiff-positive cells in the airway epithelium. Bronchoalveolar lavage fluid samples showed large numbers of eosinophils and increased mucin content up to 6 days after antigen challenge. There was also an increase in wet-to-dry lung weight ratio in the lungs of sensitized rats after antigen. These results demonstrate that prolonged reductions in lung function occur after a single antigen challenge in Brown–Norway rats that is probably due to inflammatory processes producing interstitial pulmonary edema, mucus secretion and cellular influx into the lungs.     

采用第一秒用力呼气量占肺活量的百分比对最大呼气流速-容量数值的推导

分别对177例受检者的V_(50)与FEV_(1.0)/FVC(％),V_(25)与FEV_(1.0)/FVC(％)作了相关性分析,求出相关系数(r=0.8428,0.7917;p<0.0005)和直线回归方程式,两者均呈高度正相关。用V_(50)与FEV_(1.0)/FVC(％),V_(25)与FEV_(1.0)/FVC(％)的直线回归方程式对另外48例受检者V_(50)、V_(25)值进行推算。推算出的V_(50)与实测的V_(50)、V_(25)与实测的V_(25)均呈高度正相关(r=0.9321,0.8445;P<0.0005)。同时,对119例受检者其它肺功能指标与推算的V_(50)、V_(25)也作了比较。在其它肺功能正常组中,推算出的V_(50)、V_(25)与其它肺功能符合率分别为94.1％、80.4％,在其它肺功能异常组中,符合率为100％。因此,用此法推算的V_(50)、V_(25)对小气道功能的评价具有较大的可靠性和一定的实用价值。