Tiotropium improves walking endurance in COPD.

The primary objective of this study was to evaluate the effects of a 3-week treatment with tiotropium on walking capacity in chronic obstructive pulmonary disease (COPD). After familiarisation with study procedures, 36 patients were randomised to receive tiotropium 18 µg once daily or a matching placebo in a double-blind, parallel-group study. Pre- (trough) and 2-h post-dose pulmonary function was measured. An endurance shuttle walk was then completed. The same procedures were repeated after 3 weeks of treatment. Ventilatory parameters were monitored during exercise. At 3 weeks, tiotropium significantly improved walking endurance time in comparison with placebo, with a mean±sd between-group difference of 128±141 s (p=0.017). At 3 weeks, trough values for forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC) were significantly improved with tiotropium in comparison with placebo. The post-dose response to tiotropium was statistically superior to placebo after the first dose and after 3 weeks of treatment for FEV(1), FVC and inspiratory capacity. Ventilation and tidal volume at the end of walking were significantly improved with tiotropium. 3 weeks of tiotropium resulted in a greater walking endurance in patients with COPD. Improvements in FEV(1), maximal ventilation and tidal volume may contribute to this enhanced exercise capacity.

Assessing the impact of pulmonary rehabilitation on functional status in COPD.

BACKGROUND: The optimal way of assessing the impact of pulmonary rehabilitation on functional status in chronic obstructive pulmonary disease (COPD) is currently unknown. The minimal clinically important difference for the constant work rate cycling exercise test also needs to be investigated to facilitate its interpretation. A study was undertaken to evaluate the changes in the 6-min walking test and in the constant work rate cycle endurance test immediately following and 1 year after pulmonary rehabilitation, together with the importance of these changes in terms of health status in patients with COPD. METHODS: Patients with COPD of mean (SD) age 65 (8) years and mean (SD) forced expiratory volume in 1 s (FEV1) 45 (15)% predicted were recruited from a multicentre prospective cohort study and evaluated at baseline, immediately after a pulmonary rehabilitation programme (n = 157) and at 1 year (n = 106). The 6-min walking test and the cycle endurance test were performed at each evaluation. Health status was evaluated with the St George Respiratory Questionnaire. RESULTS: Following pulmonary rehabilitation, cycle endurance time increased (198 (352) s, p<0.001) and stayed over baseline values at 1 year (p<0.001). The 6-min walking distance also showed improvements following rehabilitation (25 (52) m, p<0.001) but returned to baseline values at the 1-year follow-up. Changes in cycle endurance time were more closely associated with changes in health status than with the 6-min walking test. An improvement of 100-200 s in the cycle endurance time was associated with clinically meaningful changes in the St George Respiratory Questionnaire scores. CONCLUSIONS: The cycle endurance test was more responsive than the 6-min walking test in detecting improvement in exercise tolerance following pulmonary rehabilitation, and was also better correlated with improvements in health status. An improvement in the cycle endurance time of 100-200 s appeared to be clinically meaningful.

Endurance shuttle walking test: responsiveness to salmeterol in COPD.

Few studies have shown that the endurance shuttle walking test (ESWT) is responsive to treatment in patients with chronic obstructive pulmonary disease (COPD). This exercise test needs to be further investigated because of its relevance for activity of daily living. The aim of the present study was to evaluate, in patients with COPD, the responsiveness of the ESWT in detecting improvement in walking performance after a single dose of salmeterol. In a randomised, double-blind, placebo-controlled crossover trial, 20 patients with COPD performed two ESWT at 80% of peak capacity 2.5 h after inhaling either a placebo or 50 microg of salmeterol. Cardiorespiratory parameters were monitored during each walking test. Inspiratory capacities and Borg ratings for dyspnoea were obtained every other minute throughout the tests. Compared with placebo, salmeterol produced a significant change in lung function and a significant improvement in walking performance (mean+/-sd difference in time: 117+/-20 s; difference in distance: 160+/-277 m). At isotime (the latest exercise time that was reached on both ESWT), a significant reduction in dyspnoea was observed after bronchodilation. Bronchodilation with salmeterol reduced dyspnoea during walking and improved walking capacity in patients with chronic obstructive pulmonary disease. These findings provide further support for the use of the endurance shuttle walking test as an evaluative tool in chronic obstructive pulmonary disease.

Detection of false-positive sera in contagious agalactia with a multiantigen ELISA and their elimination with a protein G conjugate.

In serology, lack of specificity can generally be attributed to cross-reactions between different pathogens with antigens bearing similar epitopes. During seroepidemiologic surveys of contagious agalactia of sheep caused by Mycoplasma agalactiae infection, numerous sera were analyzed by enzyme-linked immunosorbent assay (ELISA). A few sera reacted with various antigens coated on plates, including the well with no antigen. This reactivity was not due to cross-reactions as initially suspected, and these multipositive sera were designated false-positive sera. Elimination of this false positivity was not possible by using covalent ELISA plates or different rabbit anti-sheep IgG conjugates. Only conjugates using monoclonal antibodies or protein G were efficient in elimination of false positivities without reducing the true specific positive titers. No false-positive sera have been observed since the implementation of protein G conjugates in the serologic diagnosis of contagious agalactia by ELISA for the past 2 years.