American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Nov 2000
Fibroproliferation occurs early in the acute respiratory distress syndrome and impacts on outcome.
The fibroproliferative phase of acute respiratory distress syndrome (ARDS) has traditionally been regarded as a late event but recent studies that suggest increased lung collagen turnover within 24 h of diagnosis challenge this view. We hypothesized that fibroproliferation is initiated early in ARDS, characterized by the presence of fibroblast growth factor activity in the lung and would relate to clinical outcome. Patients fulfilling American/European Consensus Committee criteria for ARDS and control patients ventilated for non-ARDS respiratory failure underwent bronchoalveolar lavage (BAL) and serum sampling within 24 h of diagnosis and again at 7 d. ⋯ In addition, BALF N-PCP-III concentrations at 24 h were significantly elevated in nonsurvivors of ARDS compared with survivors (p < 0.05). At 7 d, the mitogenic activity remained elevated in the ARDS group compared with control (p < 0.05) and was also significantly higher in ARDS nonsurvivors compared with survivors (67%; range 45-120 versus 31%; range 16-64, p < 0.05). These data are consistent with the hypothesis that fibroproliferation is an early response to lung injury and an important therapeutic target.
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Am. J. Respir. Crit. Care Med. · Nov 2000
Interleukin-8 messenger ribonucleic acid expression correlates with tumor progression, tumor angiogenesis, patient survival, and timing of relapse in non-small-cell lung cancer.
Tumor-associated angiogenesis is important for tumor growth and metastasis. Interleukin (IL)-8 was recently reported to be an important angiogenic factor both in vitro and in vivo. In this study we evaluated, for the first time, IL-8 messenger RNA (mRNA) expression in non-small-cell lung cancer (NSCLC), using real-time quantitative reverse-transcription-polymerase chain reaction, and correlated IL-8 mRNA expression in tumor and nontumor lung samples from 58 patients with NSCLC (29 with squamous cell carcinoma and 29 with adenocarcinoma, of whom 20 had Stage I, 10 had Stage II, and 28 had Stage III disease) with these patients' clinicopathologic characteristics, angiogenesis, and outcome. ⋯ Tumor MC correlated strongly with IL-8 mRNA expression (r = 0.56, p < 0.001). Multivariate analysis showed IL-8 mRNA expression and intratumor MC to be the most important predictors of patient survival and relapse. Thus, in NSCLC, IL-8 mRNA expression is strongly associated with tumor progression, tumor angiogenesis, survival, and time to relapse, suggesting its use as a prognostic indicator.
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Am. J. Respir. Crit. Care Med. · Nov 2000
Unsuspected pseudophysiologic emphysema in chronic persistent asthma.
The current literature emphasizes the role of airway remodeling in chronic persistent asthma and its putative effect on causing fixed expiratory airflow limitation. We studied 18 adults with chronic persistent asthma; 12 men, six women, age 59 +/- 15 yr (mean +/- SD) with fixed expiratory airflow obstruction. We measured lung elastic recoil and examined the mechanism of expiratory airflow limitation. ⋯ Despite hyperinflation, transdiaphragmatic pressures and strength were normal. The mechanisms responsible for loss of lung elastic recoil remain elusive. The high incidence of loss of lung elastic recoil in chronic persistent asthma was unexpected, and its contribution to abnormal lung function needs to be emphasized.
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Am. J. Respir. Crit. Care Med. · Nov 2000
Randomized Controlled Trial Clinical TrialRespiratory muscle endurance training in chronic obstructive pulmonary disease: impact on exercise capacity, dyspnea, and quality of life.
Inspiratory muscle training may have beneficial effects in certain patients with chronic obstructive pulmonary disease (COPD). Because of the lack of a home training device, normocapnic hyperpnea has rarely been used as a training mode for patients with COPD, and is generally considered unsuitable to large-scale application. To study the effects of hyperpnea training, we randomized 30 patients with COPD and ventilatory limitation to respiratory muscle training (RMT; n = 15) with a new portable device or to breathing exercises with an incentive spirometer (controls; n = 15). ⋯ Training-induced changes were significantly greater in the RMT than in the control group for the following variables: respiratory muscle endurance measured through sustained ventilation (+825 +/- 170 s [mean +/- SEM] versus -27 +/- 61 s, p < 0.001), inspiratory muscle endurance measured through incremental inspiratory threshold loading (+58 +/- 10 g versus +21.7 +/- 9.5 g, p = 0.016), maximal expiratory pressure (+20 +/- 7 cm H(2)O versus -6 +/- 6 cm H(2)O, p = 0.009), 6-min walking distance (+58 +/- 11 m versus +11 +/- 11 m, p = 0.002), V O(2peak) (+2.5 +/- 0.6 ml/kg/min versus -0.3 +/- 0.9 ml/kg/min, p = 0.015), and the SF-12 physical component score (+9.9 +/- 2.7 versus +1.8 +/- 2.4, p = 0.03). Changes in dyspnea, maximal inspiratory pressure, treadmill endurance, and the SF-12 mental component score did not differ significantly between the RMT and control groups. In conclusion, home-based respiratory muscle endurance training with the new device used in this study is feasible and has beneficial effects in subjects with COPD and ventilatory limitation.
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Am. J. Respir. Crit. Care Med. · Nov 2000
Sex-specific effects of asthma on pulmonary function in children.
To evaluate the effects on lung function of asthma, time since diagnosis of asthma, and age at diagnosis of asthma, we examined school children in a cohort of 2,277 fourth- and seventh-graders at least twice during a 4-yr follow-up period. Sex-specific models for each lung function were fitted through mixed-effects models that used regression splines and captured age-dependent trends in the effect of asthma on lung function. In males, a history of asthma was associated with large and statistically significant deficits in maximum midexpiratory flow (MMEF) (-4.89%) and forced expiratory flow at 75% of expired FVC (FEF(75)) (-6.62%), whereas in females these deficits were smaller (-1.93% and -2.45%, respectively) and were not statistically significant. ⋯ There was little evidence that lung growth in children with asthma "catches up" at older ages. Therefore, because a constant percent deficit in lung function implies an increasingly large absolute deficit in older children with larger lungs, these results are consistent with prior evidence that lung function deficits in children with asthma persist into adulthood. We also suggest that in children, commonly observed differences between sexes in the impact of asthma on lung function may reflect differences in the duration and age of onset of asthma in males and females.