Traffic-related air pollution and acute changes in heart rate variability and respiratory function in urban cyclists

BACKGROUND

Few studies have examined the acute health effects of air pollution exposures experienced while cycling in traffic.

OBJECTIVES

We conducted a crossover study to examine the relationship between traffic pollution and acute changes in heart rate variability. We also collected spirometry and exhaled nitric oxide measures.

METHODS

Forty-two healthy adults cycled for 1 hr on high- and low-traffic routes as well as indoors. Health measures were collected before cycling and 1-4 hr after the start of cycling. Ultrafine particles (UFPs; ≤ 0.1 μm in aerodynamic diameter), particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5), black carbon, and volatile organic compounds were measured along each cycling route, and ambient nitrogen dioxide (NO2) and ozone (O3) levels were recorded from a fixed-site monitor. Mixed-effects models were used to estimate associations between air pollutants and changes in health outcome measures relative to precycling baseline values.

RESULTS

An interquartile range increase in UFP levels (18,200/cm3) was associated with a significant decrease in high-frequency power 4 hr after the start of cycling [β = -224 msec2; 95% confidence interval (CI), -386 to -63 msec2]. Ambient NO2 levels were inversely associated with the standard deviation of normal-to-normal (NN) intervals (β = -10 msec; 95% CI, -20 to -0.34 msec) and positively associated with the ratio of low-frequency to high-frequency power (β = 1.4; 95% CI, 0.35 to 2.5) 2 hr after the start of cycling. We also observed significant inverse associations between ambient O3 levels and the root mean square of successive differences in adjacent NN intervals 3 hr after the start of cycling.

CONCLUSIONS

Short-term exposures to traffic pollution may contribute to altered autonomic modulation of the heart in the hours immediately after cycling.

Spirometry parameters in patients undergoing hemodialysis with bicarbonate and acetate dialysates

INTRODUCTION

End-stage renal disease causes impairment of all body organs including the heart and the lung. The main problems in the afflicted patients are pulmonary edema due to increased permeability of the capillaries, intravascular and interstitial volume overload, hypertension, and congestive heart failure. These changes cause altered physiologic and mechanical function of the lungs and subsequently increase in airway resistance. We aimed to study the impact of hemodialysis on spirometry parameters.

MATERIALS AND METHODS

In a cross-sectional study performed on 41 patients on maintenance hemodialysis, spirometry was done before and after the dialysis session. The patients were on either acetate or bicarbonate hemodialysis with the same method, dialysis machine, and duration of dialysis. Alterations in spirometry parameters including forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, and maximal midexpiratory flow rate were determined and their relation with serum electrolytes, serum creatinine, blood urea nitrogen, and hemoglobin were analyzed.

RESULTS

Twenty-nine patients undergoing dialysis with bicarbonate dialysate and 21 on dialysis with acetate were compared. Improvement in spirometry parameters was only significant in patients undergoing dialysis with bicarbonate dialysate. All spirometry parameters showed significant increases in the bicarbonate group except for the FEV1/FVC ratio. Furthermore, significant increase in these parameters was only prominent in the men. Postdialysis weight reduction and laboratory indexes had no significant correlation with improvement of spirometry parameters.

CONCLUSIONS

Dialysis with bicarbonate dialysate causes significant improvement in spirometry parameters in men on maintenance dialysis. This effect might be independent of the effect of removing the volume overload by dialysis.

[Effect of resveratrol on chronic obstructive pulmonary disease in rats and its mechanism]

The purpose of this study is to establish COPD animal model by intra-tracheal instillation of bleomycin (BLM) once and exposure to cigarette smoke for continuous 27 d, and to observe the effects of the inhalation on the model. At the 29th day, blood samples were taken from cervical artery for blood-gas analysis and parameters of lung function were recorded. Bronchoalveolar lavage fluid (BALF) was collected to measure intercellular adhesion molecule-1 (ICAM-1) concentration. The results showed that atomization inhaled resveratrol could alleviate rat COPD lung injury accompanied by amelioration of pathological changes, increase the ratio of forced expiratory volume in 0.3 s (FEV0.3) and forced vital capacity (FVC), and decrease the ICAM-1 level in BALF. The ultimate reduction of inflammatory factors was involved, at least in part, in the mechanism of resveratrol effects.

Same efficacies of ipratropium and salbutamol in reversing methacholine-induced bronchoconstriction

Efficacy of salbutamol (S) was compared to that of ipratropium (I) or to their association, after methacholine challenge testing (MCT). MCT was performed in 4 groups of 10 patients suspected to suffer from asthma; mean changes in FEV1, maximal midexpiratory flow rate (MMFR), and airway resistance (Raw) were the same in all groups. After MCT, the group 1 patients inhaled S and then I, 10 min later; both drugs were given in the reverse order to the group 2 patients. The group 3 patients inhaled a mixture of both drugs just after MCT; the group 4 patients were not given any bronchodilator till the 20th min after MCT, when they inhaled S. Short-term (10 min) bronchodilator effects of S, I or S + I on spirometric variables were of the same magnitude and Raw returned to its baseline value. Further improvement (10-20 min) in FEV1 was mainly due to spontaneous recovery, whereas further increase in MMFR was due also to bronchodilator actions of drugs. It is concluded that ipratropium could be proposed as an alternative bronchodilator to salbutamol after MCT.

The impact of spirometry on pediatric asthma diagnosis and treatment

Research has shown that spirometry is underutilized in the clinical setting. This study profiles the use of spirometry in an asthma management program at an inner-city community health clinic. Eligible subjects included 56 children who presented with an acute asthma exacerbation. Physicians recorded patient diagnosis before and after viewing spirometry. Bivariate and multivariate analysis was used to determine associations between symptoms and forced expiratory volume in 1 second (FEV1). Physicians changed 30.4% of patients' treatment plans after viewing spirometry results. Wheezing was significantly associated with FEV1 in bivariate analysis; however, multivariate modeling failed to identify significant relationships. The use of spirometry influenced patient diagnosis and treatment.

A randomized, double-blind trial of the effect of anti-asthma treatment on lung function in children with asthma

BACKGROUND

Pulmonary function tests (PFTs) and especially spirometry measures are useful tools in evaluating early response to treatment of asthma in children mainly due to their worldwide availability. The aim of our study was to determine the effects of anti-asthma treatment in children, equally on FEV(1), FEF25-75%, R(int) and SR(aw) values.

METHODS

Children 6-18 years of age with moderate atopic asthma were randomized to 4-week, placebo-controlled, double-blind trial. Patients were randomly allocated to receive 200 microg budesonide (B) (n=29), 5 or 10 mg (according to age) montelukast (M) (n=29), 200 microg B + 5 or 10 mg M (n=29), 200 microg B + 9 microg formoterol (F) (n=29) or placebo (n=27). FEV(1,) FEF25-75%, R(int), SR(aw) were measured before and after treatment.

RESULTS

R(int), SR(aw), FEV(1) improved significantly in all active treatment groups while FEF25-75% improved significantly only in BM group and M group. Combination therapy, showed significantly greater effects on R(int) than monotherapy: BM group compared to B group (P=0.01) and M group (P=0.03) and BF group compared to B group (P=0.01) and M group (P=0.04).

CONCLUSION

This study shows that using single parameter for monitoring asthma can be misleading. Using combination of lung function techniques provides better assessment of treatment. Results of our study confirm this hypothesis. The best effect on large and small airways was achieved with combined anti-inflammatory therapy.

Forskolin versus sodium cromoglycate for prevention of asthma attacks: a single-blinded clinical trial

To determine the efficacy of forskolin in preventing asthma attacks, we performed a single-blinded clinical study in children and adult out-patients at a public hospital in Mexico. Forty patients of either sex with mild persistent or moderate persistent asthma were assigned randomly to 6 months of treatment with forskolin at 10 mg/day orally (capsules) or with two inhalations of sodium cromoglycate every 8 h, i.e. three times a day. The number of patients who had asthma attacks during the treatment period was significantly lower among those receiving forskolin (8/20, 40%) than among those receiving sodium cromoglycate (17/20, 85%). Values of forced expiratory volume in 1 s and forced expiratory flow, mid-phase, A similar in the two groups during the treatment period. We conclude that forskolin is more effective than sod cromoglycate in preventing asthma attacks in patients with mild persistent or moderate persistent asthma.

Eosinophilic inflammation, remodeling of lower airway, bronchial responsiveness and cough reflex sensitivity in non-asthmatic subjects with nasal allergy

BACKGROUND

It has been reported that nasal allergy influences the lower airway inflammation and functions. We elucidated whether nasal allergy would contribute to lower airway inflammation and functions.

METHODS

266 subjects aged 21-39 years were interviewed with special emphasis on history of asthma and nasal allergies (perennial allergic rhinitis (PAR) and seasonal allergic rhinitis (Japanese cedar pollinosis; PO)). Symptomatic subject was defined when nasal symptoms were present during a 3-week study period. Pulmonary function, provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC20), capsaicin cough threshold defined as capsaicin concentration eliciting 5 or more coughs (C5) and eosinophil percentage in hypertonic saline-induced sputum were measured.

RESULTS

Based on the interview, 232 subjects without asthma were divided into symptomatic (n = 25) and asymptomatic (n = 22) PAR, PO on-season (n = 15) and off-season (n = 36), and non-nasal allergy subjects (control) (n = 134). Sputum eosinophils were significantly greater in symptomatic PAR than another four groups (p < 0.01). FEV1/FVC ratio was significantly lower in PAR than control (p < 0.05). Maximum mean expiratory flow was lower in PAR than control (asymptomatic: p < 0.05, symptomatic: p = 0.06). C5 was not different among groups. PAR tended to have a lower PC20 compared to control (symptomatic: p = 0.078; asymptomatic: p = 0.086).

CONCLUSIONS

These results suggest that eosinophilic inflammation occurred in symptomatic period of PAR may contribute to development of lower airway remodeling and bronchial hyperresponsiveness. Reversely, PO may not be associated with lower airway eosinophilic inflammation or abnormal bronchial functions. Nasal allergy dose not influence the cough reflex sensitivity.

Relationship between radical generation by urban ambient particulate matter and pulmonary function of school children

The mechanisms by which particulate matter (PM) produces adverse effects on the respiratory system, such as pulmonary dysfunction in children, are largely unknown. However, oxidative stress is thought to play an important role. Various chemical compounds in ambient particulate matter, including transition metals and aromatic organic compounds, may contribute to adverse effects through intrinsic generation of reactive oxygen species (ROS). It was hypothesized that ROS generation by PM, as determined through electron spin resonance (ESR) spectroscopy, may be negatively associated with pulmonary function in school children. PM(2.5), PM(10), and total suspended particulates (TSP) were sampled at the playgrounds of six elementary schools in the city of Maastricht, the Netherlands. All children (8-13 yr) from the six schools were asked to undergo spirometry. Multivariate linear regression models were constructed to evaluate associations between oxygen radical formation by PM and lung function. The radical-generating capacity per microgram PM correlated negatively to forced expiratory volume in 1 s (FEV(1)) and forced expiratory flow at 50% (FEF(50%)) of forced vital capacity (FVC). The data indicate that chemical features that contribute to intrinsic generation of ROS may be relevant for PM risk assessment.

A controlled trial of long-term inhaled hypertonic saline in patients with cystic fibrosis

BACKGROUND

Inhaled hypertonic saline acutely increases mucociliary clearance and, in short-term trials, improves lung function in people with cystic fibrosis. We tested the safety and efficacy of inhaled hypertonic saline in a long-term trial.

METHODS

In this double-blind, parallel-group trial, 164 patients with stable cystic fibrosis who were at least six years old were randomly assigned to inhale 4 ml of either 7 percent hypertonic saline or 0.9 percent (control) saline twice daily for 48 weeks, with quinine sulfate (0.25 mg per milliliter) added to each solution to mask the taste. A bronchodilator was given before each dose, and other standard therapies were continued during the trial.

RESULTS

The primary outcome measure, the rate of change (slope) in lung function (reflected by the forced vital capacity [FVC], forced expiratory volume in one second [FEV1], and forced expiratory flow at 25 to 75 percent of FVC [FEF25-75]) during the 48 weeks of treatment, did not differ significantly between groups (P=0.79). However, the absolute difference in lung function between groups was significant (P=0.03) when averaged across all post-randomization visits in the 48-week treatment period. As compared with the control group, the hypertonic-saline group had significantly higher FVC (by 82 ml; 95 percent confidence interval, 12 to 153) and FEV1 (by 68 ml; 95 percent confidence interval, 3 to 132) values, but similar FEF25-75 values. The hypertonic-saline group also had significantly fewer pulmonary exacerbations (relative reduction, 56 percent; P=0.02) and a significantly higher percentage of patients without exacerbations (76 percent, as compared with 62 percent in the control group; P=0.03). Hypertonic saline was not associated with worsening bacterial infection or inflammation.

CONCLUSIONS

Hypertonic saline preceded by a bronchodilator is an inexpensive, safe, and effective additional therapy for patients with cystic fibrosis. (ClinicalTrials.gov number, NCT00271310.)

Mucus clearance and lung function in cystic fibrosis with hypertonic saline

BACKGROUND

Abnormal homeostasis of the volume of airway surface liquid in patients with cystic fibrosis is thought to produce defects in mucus clearance and airway defense. Through osmotic forces, hypertonic saline may increase the volume of airway surface liquid, restore mucus clearance, and improve lung function.

METHODS

A total of 24 patients with cystic fibrosis were randomly assigned to receive treatment with inhaled hypertonic saline (5 ml of 7 percent sodium chloride) four times daily with or without pretreatment with amiloride. Mucus clearance and lung function were measured during 14-day baseline and treatment periods.

RESULTS

Long-term inhalation of hypertonic saline without pretreatment with amiloride (i.e., with placebo pretreatment) resulted in a sustained (> or =8 hours) increase in 1-hour rates of mucus clearance, as compared with those with amiloride pretreatment (14.0+/-2.0 vs. 7.0+/-1.5 percent, respectively; P=0.02) and increased 24-hour rates of mucus clearance over baseline. Furthermore, inhalation of hypertonic saline with placebo improved the forced expiratory volume in one second (FEV1) between the baseline period and the treatment period (mean difference, 6.62 percent; 95 percent confidence interval, 1.6 to 11.7; P=0.02), whereas hypertonic saline with amiloride did not improve FEV1 (mean difference, 2.9 percent; 95 percent confidence interval, -2.2 to 8.0; P=0.23). Forced vital capacity (FVC), the forced expiratory flow between 25 and 75 percent of FVC (FEF25-75), and respiratory symptoms also significantly improved in patients treated with hypertonic saline and placebo, whereas the residual volume as a proportion of total lung capacity (RV:TLC) did not change in either group. A comparison of the changes in lung function in the two groups showed no significant difference. In vitro data suggested that sustained hydration of airway surfaces was responsible for the sustained improvement in mucus clearance, whereas inhibition of osmotically driven water transport by amiloride accounted for the observed loss of clinical benefit.

CONCLUSIONS

In patients with cystic fibrosis, inhalation of hypertonic saline produced a sustained acceleration of mucus clearance and improved lung function. This treatment may protect the lung from insults that reduce mucus clearance and produce lung disease.

Effects of iohexol on ventilatory functions in patients undergoing diagnostic coronary angiography

BACKGROUND AND OBJECTIVES

Adverse respiratory reactions have been reported with intravascular radiographic contrast media. The aim of the present study is to assess the effects of iohexol on pulmonary functions in patients undergoing diagnostic coronary angiography (CA).

MATERIALS AND METHODS

30 patients enrolled in the study. The respiratory functions of the patients were measured at three different stages during angiography (before, immediately after and 2 h later) and arterial blood gas analyses were performed at six stages during CA (before, immediately after the insertion of angiography catheter, 2 min after the injection of contrast agent, at the end of angiography, an hour and 2 h after angiography). A single, experienced angiographer performed the angiography procedures via radial artery route. Totally six multiple angled views of the left and right coronary arteries were recorded in all patients by hand injection. None of the patients were performed ventriculography.

RESULTS

Angiography caused significant reduction in forced expiratory volume in 1 sec [FEV1] (from 103 +/- 15 to 95 +/- 17, p < 0.01), forced vital capacity [FVC] (from 99 +/- 13 to 95 +/- 18, p < 0.05) and maximum mid-expiratory flow rate [MMF] (from 95 +/- 33 to 84 +/- 29, p < 0.01) whereas there were no significant changes in the mean FEV1/FVC ratios at different stages of angiography. Statistically significant decrease in PaO2 (from 91 +/- 10 to 85 +/- 13 mmHg, p < 0.01) and arterial O2 saturation (from 97 +/- 1% to 96 +/- 1%, p < 0.01) were also observed. Data in present study showed a clinically insignificant but statistically significant restrictive impairment in pulmonary functions.

CONCLUSIONS

Diagnostic CA using iohexol decreases ventilatory functions in a small but significant extent in patients without any overt pulmonary disease.

Inhaled mannitol for the treatment of mucociliary dysfunction in patients with bronchiectasis: Effect on lung function, health status and sputum

OBJECTIVE

Inhaled mannitol increases mucus clearance in patients with bronchiectasis by an unclear mechanism. The effect of mannitol on lung function, health status and sputum properties was investigated.

METHODOLOGY

Nine patients with bronchiectasis inhaled 400 mg of mannitol once daily for 12 days. Health status was assessed using the St George's Respiratory Questionnaire (SGRQ). Sputum was analysed for viscosity, elasticity, spinnability, surface tension, contact angle, solids, mucociliary transportability (MCTR) on a frog palate, and cough transportability (CTR) on a simulated cough machine.

RESULTS

Lung function was unchanged with treatment (baseline FEV1 82.0 +/- 16.2%) apart from an improvement in FEF from 85.4 +/- 13% (baseline) to 90.7 +/- 14.4% (P < 0.05; 12th treatment; visit 7). The total SGRQ score (mean +/- SD) of 49.3 +/- 13.8 at baseline, decreased by 12.4 +/- 10.2 (P < 0.01; visit 7) and 10.1 +/- 9.4 units (P < 0.02) 6-10 days after treatment cessation. The baseline subscores for symptoms (72.9 +/- 11.8), activity (44.7 +/- 20.9) and impact (44.4 +/- 14.3) were reduced by 0.8 +/- 9.1 (P > 0.7), 8.4 +/- 16.0 (P > 0.1) and 19.2 +/- 13.7 (P < 0.005) units, respectively (visit 7). Mannitol reduced the baseline (mean +/- SE) surface tension from 94.5 +/- 1.4 to 84.7 +/- 2.1 mN/m (P < 0.0001), contact angle from 51.1 +/- 2.8 to 33.2 +/- 2.4 degrees (P < 0.0001), spinnability from 11.6 +/- 0.4 to 10.0 +/- 0.2 mm (P < 0.005), and solids from 5.7 +/- 0.4 to 4.3 +/- 0.7% (P < 0.02), acutely (visit 7). Viscosity, elasticity and MCTR did not change significantly, while CTR was increased from 25.8 +/- 1.0 to 34.1 +/- 2.7 mm (P < 0.003).

CONCLUSION

Mannitol significantly improved the health status over 12 days and this improvement was maintained for 6-10 days after cessation of treatment. In addition, mannitol reduced the tenacity, increased the hydration of mucus acutely and improved cough clearability in patients with bronchiectasis.

The effect of air pollution on lung development from 10 to 18 years of age

BACKGROUND

Whether exposure to air pollution adversely affects the growth of lung function during the period of rapid lung development that occurs between the ages of 10 and 18 years is unknown.

METHODS

In this prospective study, we recruited 1759 children (average age, 10 years) from schools in 12 southern California communities and measured lung function annually for eight years. The rate of attrition was approximately 10 percent per year. The communities represented a wide range of ambient exposures to ozone, acid vapor, nitrogen dioxide, and particulate matter. Linear regression was used to examine the relationship of air pollution to the forced expiratory volume in one second (FEV(1)) and other spirometric measures.

RESULTS

Over the eight-year period, deficits in the growth of FEV(1) were associated with exposure to nitrogen dioxide (P=0.005), acid vapor (P=0.004), particulate matter with an aerodynamic diameter of less than 2.5 microm (PM(2.5)) (P=0.04), and elemental carbon (P=0.007), even after adjustment for several potential confounders and effect modifiers. Associations were also observed for other spirometric measures. Exposure to pollutants was associated with clinically and statistically significant deficits in the FEV(1) attained at the age of 18 years. For example, the estimated proportion of 18-year-old subjects with a low FEV(1) (defined as a ratio of observed to expected FEV(1) of less than 80 percent) was 4.9 times as great at the highest level of exposure to PM(2.5) as at the lowest level of exposure (7.9 percent vs. 1.6 percent, P=0.002).

CONCLUSIONS

The results of this study indicate that current levels of air pollution have chronic, adverse effects on lung development in children from the age of 10 to 18 years, leading to clinically significant deficits in attained FEV(1) as children reach adulthood.

Use of submaximal inhalation and spirometry to assess the effects of ozone exposure

Spirometric measures of airway obstruction are strongly influenced by the neurally mediated reduction in total lung capacity that accompanies ozone exposure. This study was conducted to evaluate a method for quantifying the effects of performing spirometry from a reduced inspiratory position on measures of airway obstruction, and to apply the method to published ozone-response data. Nineteen healthy, nonsmoking adults, 18-30 yr of age, each performed 17 forced expiratory maneuvers from inspiratory volumes that ranged from functional residual capacity to total lung capacity. In general, measures of airway obstruction were related strongly to total expired volume, and approximately 80% of the ozone-induced decrease in forced expiratory volume in 1 s (FEV1.0) resulted from the reduction in forced vital capacity. Results indicated that, for young, healthy, nonsmoking adults, spirometric values from maneuvers conducted from reduced inspiratory positions can be predicted accurately and precisely in the unexposed state, allowing interpretation of measures of ozone-induced airway obstruction.

Effects of ranitidine on pulmonary function tests of patients with chronic obstructive pulmonary disease

Since the incidence of peptic ulcer and gastroesophageal reflux (GER) is more common in patients with chronic obstructive pulmonary disease (COPD) than normal population, H(2) receptor blockers are given more extensively to COPD patients. This study evaluated the effects of Ranitidine on pulmonary function tests (PFT) of the patients having COPD and peptic ulcer or GER, and of healthy volunteers. Fifty milligrams of Ranitidine was given intravenously to 30 COPD patients and 25 healthy volunteers. PFT were done before and 15, 30, 60, 120min after Ranitidine injection. Although mean forced vital capacity (FVC), forced expiratory volume in 1s (FEV(1)) and forced midexpiratory flow rate (FEF(25-75%)) of COPD patients were found to be decreased 60 and 120min after Ranitidine injection, the decrements were statistically insignificant. The decrements in PFT of healthy volunteers were also not statistically significant.H(2) receptor blockers can be used safely for treatment of gastrointestinal disorders in COPD patients who have mild or moderate obstruction. Minimal decreases in FEV(1) and FVC due to treatment by H(2) receptor blockers may clinically worsen COPD patients who have severe obstruction.

Clinical studies in asthmatics with a new non-extra fine HFA formulation of beclometasone dipropionate (BDP Modulite)

The main objective of the clinical development programme for BDP Modulite, a new non-extra fine formulation of beclometasone dipropionate (BDP) in hydrofluoroalkane (HFA), has been to demonstrate therapeutic equivalence compared with standard BDP chlorofluorocarbon (CFC) products at the recommended posology (delivered dose and patient population). A total of 1158 asthmatic patients were included in five clinical studies and 658 patients were treated with BDP Modulite. Four studies were undertaken in mild or moderate-to-severe asthmatic adults, while one study was carried out in children. The duration of treatment was 12 weeks in three studies and 6 weeks in the other two studies. A range of doses of BDP Modulite from 200 micrograms bid up to 1500 micrograms bid was evaluated against CFC comparators. The primary efficacy variable in all studies was morning PEFR while secondary variables included other lung function parameters, symptom scores and salbutamol use. All studies demonstrated equivalence of efficacy for morning PEFR for BDP Modulite versus BDP-CFC when compared on a microgram for microgram basis. The secondary outcome variables also consistently support similar efficacy of the two products. The safety and tolerability profile for BDP Modulite was similar to BDP-CFC; the incidence of adverse events was comparable between treatments and plasma and urinary cortisol were generally unchanged in patients receiving 1000 micrograms day-1 for 6-12 weeks. In conclusion, the results of the clinical studies with BDP Modulite show that this new HFA formulation allows a seamless transition to CFC-free BDP, thus simplifying the changeover.

Pulmonary function changes and immunomodulation of cytokine expression by zafirlukast after sensitization and allergen challenge in brown Norway rats

BACKGROUND

The cysteinyl leukotrienes are known important mediators in bronchial asthma.

OBJECTIVE

Our purpose was to evaluate the effect of zafirlukast on the late-phase reaction, bronchial hyper-responsiveness (BHR) and T cell-related cytokine mRNA expression in ovalbumin (OA)-sensitized brown Norway rats (BNRs).

METHODS

Thirty BNRs were equally divided into three groups. Group I and II animals were sensitized and then provoked with OA. Zafirlukast was given intraperitoneally (i.p.) to group I animals prior to provocation. Group II animals received i.p. normal saline. Group III animals (controls) were not sensitized and breathed aerosolized saline. After OA provocation, the animals were anaesthetized. Pulmonary function tests (PFT) were performed at baseline and after varying doses of acetylcholine. Thereafter, bronchoalveolar lavage (BAL) was performed and the lungs were examined histologically. Total RNA was extracted from lung tissue and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using primers for IL-2, IL-4, IL-5, IL-6, IL-10, TNF-alpha, IFN-gamma, iNOS and beta-actin.

RESULTS

Group II OA-treated BNRs had worse PFT results, more severe bronchoconstriction in response to acetylcholine, and more severe inflammation in lung tissue than the other two groups. Group II had higher IL-2, IL-4, IL-10 and IFN-gamma cytokine levels in BAL fluid and higher IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma, TNF-alpha and iNOS mRNA levels when compared with group I.

CONCLUSION

Zafirlukast is effective in preventing late-phase bronchoconstriction and BHR, reducing inflammatory response, and decreasing IL-2, IL-4, IL-5, IL-6, IL-10 and IFN-gamma and iNOS mRNA expression.

Methacholine versus histamine: paradoxical response of spirometry and ventilation distribution

We investigated the differential effect of histamine and methacholine on spirometry and ventilation distribution (where indexes S(cond) and S(acin) represent conductive and acinar ventilation heterogeneity; Verbanck S, Schuermans D, Van Muylem A, Noppen M, Paiva M, and Vincken W. J Appl Physiol 83: 1807-1816, 1997). Thirty normal subjects were challenged with cumulative doses of 6.52 micromol histamine and, on a separate day, with either 6.67 micromol methacholine (equal-dose group; n = 15) or 13.3 micromol methacholine (double-dose group; n = 15). Largest average forced expiratory volume in 1 s (FEV(1)) decreases or S(cond) increases obtained in either group were -9% and +286%, respectively; S(acin) remained unaffected at all times. In the equal-dose group, a smaller FEV(1) decline (P = 0.002) after methacholine was paralleled by a smaller S(cond) increase (P = 0.041) than with histamine. However, in the double-dose group, methacholine maintained a smaller FEV(1) decline (P = 0.009) while inducing a larger S(cond) increase (P = 0.006) than did histamine. The differential action of histamine and methacholine is confined to the conductive airways, where histamine likely causes the greatest overall airway narrowing and methacholine induces the largest parallel heterogeneity in airway narrowing, probably at the level of the large and small conductive airways, respectively. The observed ventilation heterogeneities predict a risk for dissociation between ventilation-perfusion mismatch and spirometry, particularly after methacholine challenge.

Budesonide but not nedocromil sodium reduces exhaled nitric oxide levels in asthmatic children

Exhaled nitric oxide (ENO) has been proposed as a marker of airway inflammation in asthma and could be useful to evaluate the response to anti-inflammatory treatment. We investigated the effect of budesonide and nedocromil sodium on ENO levels and lung function in asthmatic children. Twenty stable steroid-naïve asthmatic children were randomized in a single blind, cross-over study to receive inhaled budesonide (group A) or nedocromil sodium (group B) for 6 weeks. ENO was measured with a chemiluminescence analyser at baseline and at the end of each treatment period. Repeated-measures ANOVA was carried out. In asthmatic baseline ENO levels [mean 32.5 ppb, 95% confidence interval (CI) 26.4 to 38.7] were significantly higher compared to reference values (8.7 ppb, 95% CI 8.1 to 9.2, P<0.001). There were no treatment-order effect, no carry-over effect and in both groups the response pattern was the same: budesonide significantly lowered ENO levels from 41.0 ppb to 22.8 ppb in group A (mean, P<0.01) and from 22.6 ppb to 13.0 ppb in group B, (mean, P<0.05), while nedocromil did not reduce ENO values (from 24.4 ppb to 22.6 ppb in group B and from 22.8 ppb to 38.0 ppb in group A, mean, P = NS and P<0.01 respectively). After budesonide treatment ENO values of asthmatics were still significantly higher than in healthy children The baseline values of FEV1 and FEF(25-75) were normal in both groups and no significant changes were observed during the study. In conclusion, our study shows that budesonide, but not nedocromil sodium, significantly reduces ENO levels in stable asthmatic children even in absence of changes in the lung function.

The short-term repeatability of histamine bronchial testing in young males. The SUS study

We have measured bronchial responsiveness (BR) to histamine on two occasions between 5 and 24 h apart, to determine if conventional and new indices of BR are repeatable. A random sample of 29 healthy male subjects with a mean age of 19 (SD 3.44) years from a larger study repeated a Yan method test of BR, recording both partial and maximal expiratory flow volume (PEFV and MEFV) curves. From the MEFV curves log-dose slopes (LDS) for forced expiratory volume in 1 sec (FEV1), forced expiratory flow between 25% and 75% of forced vital capacity (FVC) (FEF(25-75%)), mean expiratory flow at 30% and 40% of FVC (MEF30, MEF40), and the first moment of the spirogram (alpha1) truncated at 75% and 90% of FVC were calculated, as well as the provocative dose that induces a 20% fall in FEV1 (PD20FEV1). From the PEFV curves LDS for alpha(1)75% and alpha(1)90%, and MEF30 and MEF40 were derived. Apart from MEF30 and alpha(1)90% the second test was significantly lower (P<0.05) than the first when measuring the repeatability of spirometric indices, whereas the LDS of the indices showed no significant change. The repeatability expressed as intra-class correlation coefficient (ICC) was highest for LDS FEV1 (0.87), second highest for LDS MEF40 (0.67) and LDS MEF30 (0.65). The LDS for moment indices were much less repeatable and the lowest ICC was found in all LDS indices derived from PEFV curves. Within-subject variance was not influenced by atopic status, smoking habits or recordable PD20FEV1. As tests for bronchial hyper-responsiveness (BHR) the LDS of FEV1, MEF40 and MEF30 seem to be acceptable for use in population studies.

e-NO peak versus e-NO plateau values in evaluating e-NO production in steroid-naive and in steroid-treated asthmatic children and in detecting response to inhaled steroid treatment

SUMMARY. Airway nitric oxide (NO) production can be measured by chemiluminescence analyzer in children able to perform a single low exhalation. The aim of the present study was to evaluate whether exhaled NO (e-NO) peaks (first part of the exhalation) were as useful as e-NO plateaus (last part of the exhalation) in evaluating e-NO production in asthmatic children and in detecting responses to inhaled steroid treatment. E-NO peak, plateau, and rate of production values were measured in 100 atopic asthmatic children using a chemiluminescence analyser. Thirty-seven patients (mean age, 11.1 +/- 0.7 years) were receiving inhaled steroids (flunisolide, 0.8-1 mg daily) or beclomethasone (0.2-0.4 mg daily), while the remaining 63 (mean age, 12.0 +/- 0.4 yrs) were-steroid naive and treated only with inhaled beta(2)-agonists on an as-needed basis. Fifteen out of the 63 steroid-naive patients were reevaluated after a short course (3 weeks) of inhaled corticosteroid treatment (flunisolide, 0.8-1 mg daily, or beclomethasone, 0.2-0.4 mg daily). Regardless of the type of data analysis (peak, plateau, or rate of production), the e-NO values of the steroid-naive patients were significantly higher than those of inhaled steroid-treated patients (P < 0.01, each comparison). Similarly, in the subgroup of steroid-naive patients, the three methods were able to detect a decrease in e-NO levels by inhaled steroid therapy (P < 0.001, each comparison). Plotting the difference between e-NO peak and e-NO plateau values against their average, the peak e-NO concentrations were higher than e-NO plateau values. This difference was independent of the absolute e-NO concentration. The results of the two types of data analysis seems to agree more closely in steroid-naive patients than in steroid treated patients, or in the subgroup of steroid-naive patients who received a short course treatment with inhaled steroids. In steroid-treated subjects, the differences were up to five times higher for peak than plateau e-NO values. These data suggest that both e-NO plateau and e-NO peak values are useful in detecting airway NO production in atopic asthmatic children, but they cannot be used interchangeably. Because of possible nasal contamination in e-NO peak measurement, we prefer e-NO plateau levels for evaluating lower airway e-NO production.

Conservation of small-airway function by tacrolimus/cyclosporine conversion in the management of bronchiolitis obliterans following lung transplantation

We studied serial lung function in 11 patients with bronchiolitis obliterans syndrome who were treated with tacrolimus conversion following lung or heart-lung transplantation. Our results show that tacrolimus conversion slows the decline of lung function in bronchiolitis obliterans syndrome. The attenuation continues for at least 1 year following conversion.

Effects of R-(+)- and S-(-)-limonene on the respiratory tract in mice

The effects of airborne R-(+)- and S-(-)- limonene were studied in conscious BALB/c mice by continuous monitoring respiratory rate (f), tidal volume (VT) and mid-expiratory flow rate (VD) during an exposure period of 30 min. Both enantiomers decreasedf from a trigeminal reflex, i.e., due to sensory irritation. The exposure concentration decreasing f by 50% (RD50) in the first 10 min of the exposure period was estimated to be 1,076 ppm for R-(+)-limonene and 1,467 ppm for S-(-)-limonene. Results for sensory irritation of R-(+)-limonene in BALB/c mice and humans are in close agreement. The reported sensory irritation threshold is above 80 ppm in humans while the no-observed-effect level was estimated to be 100 ppm in mice. The enantiomers were devoid of pulmonary irritation or general anesthetic effects with R-(+)-limonene < or =1,599 ppm and S-(-)-limonene < or =2,421 ppm. R-(+)-limonene did not influence VT below 629 ppm. S-(-)-limonene increased VT above 1,900 ppm. Both enantiomers induced a mild bronchoconstrictive effect above 1,000 ppm.

Effects of perilla seed oil supplementation on leukotriene generation by leucocytes in patients with asthma associated with lipometabolism

BACKGROUND

Dietary sources of alpha-linolenic acid, such as perilla seed oil, may have the capacity to inhibit the generation of leukotrienes (LTs) by leucocytes in patients with asthma, as has been reported with the consumption of other long-chain n-3 fatty acids.

METHODS

The factors affecting the suppression of leukotriene (LT) C4 generation by leucocytes were examined by comparing the clinical features of patients with asthma who had been given dietary perilla seed oil (n-3 fatty acids). Group A consisted of patients in whom the leucocyte generation of LTC4 was suppressed by dietary perilla seed oil. Group B consisted of those in whom LTC4 generation was not suppressed.

RESULTS

LTC4 generation by leucocytes decreased significantly in group A after 2 (p < 0.05) and 4 weeks (p < 0.05); conversely, it increased significantly in group B after 4 weeks (p < 0.05). The two study groups differed significantly in terms of LTC4 generation by leucocytes after 4 weeks of dietary supplementation (p < 0.05). Ventilatory parameters such as peak expiratory flow (PEF), forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) increased significantly after 4 weeks of dietary supplementation in group A (p < 0.05). Values of PEF, FVC, FEV(1) and maximum expiratory flow at 25% of the forced vital capacity (V(25)) differed significantly between groups A and B prior to dietary supplementation. Serum levels of total cholesterol, low-density lipoprotein (LDL) cholesterol and phospholipid were significantly decreased by dietary supplementation in group A after 4 weeks. Serum levels of total cholesterol, triglyceride, high-density lipoprotein cholesterol, LDL cholesterol and phospholipid differed significantly between the two study groups prior to dietary supplementation. Serum levels of triglyceride and LDL cholesterol differed significantly between the two study groups after 4 weeks of dietary supplementation.

CONCLUSIONS

Dietary supplementation with perilla seed oil in selected patients with asthma suppresses the generation of LTC4 and is associated with clinical features such as respiratory function and lipometabolism.

Dose-ranging study of a new steroid for asthma: mometasone furoate dry powder inhaler

A new formulation of mometasone furoate (MF) for administration by dry powder inhaler (DPI) was evaluated for the treatment of asthma. A 12-week, double-blind, placebo-controlled dose-ranging study compared the efficacy and safety of three doses of MF DPI (100, 200 and 400 mcg b.i.d) with beclomethasone dipropionate (BDP) 168 mcg b.i.d. administered by metered dose inhaler in 365 adult or adolescent patients being treated with inhaled glucocorticoids. The mean change from baseline to endpoint (last treatment visit) for forced expiratory volume in 1 sec (FEV1) was the primary efficacy variable. Secondary efficacy variables included other objective measures of pulmonary function [forced vital capacity (FVC), forced expiratory flow 25-75% (FEV25-75%.) and peak expiratory flow rate (PEFR)] as well as subjective measures of therapeutic response (patients' daily evaluation of asthma symptoms and physicians' evaluation). At endpoint, all four active treatments were significantly more effective than placebo (P < 0.01) in improving FEV1 (MF DPI 5 to 7%, BDP 3%, placebo -6.6%) and all other measures of pulmonary function (FVC: MF DPI 4 to 5%, BDP 2%, placebo -4.7%; FEF25-75%: MF DPI 6 to 18%, BDP 7.5%, placebo -9.5%; PEFR (AM): MF DPI 5 to 10%, BDP 5.7%, placebo -7%). A consistent trend was observed for better improvement in patients treated with MF DPI 200 mcg b.i.d. than with MF DPI 100 mcg b.i.d., with no apparent additional benefit of MF DPI 400 mcg b.i.d. Results for the MF DPI 100 mcg b.i.d. and BDP 168 mcg b.i.d. treatment groups were similar. Patients' and physicians' subjective evaluations of symptoms found similar improvement in the MF DPI 200 and 400 mcg b.i.d. treatment groups, which were slightly better than that in the MF DPI 100 mcg b.i.d. group. Symptoms tended to worsen in the placebo group. MF DPI was well tolerated at all dose levels and the most frequently reported treatment-related adverse effects were headache, pharyngitis and oral candidiasis. No evidence of HPA-axis suppression was detected in any treatment group. In summary, all doses of MF DPI were well tolerated and significantly improved lung function and MF DPI 400 mcg (200 mcg b.i.d.) was the optimal dose in this study of patients with moderate persistent asthma.

Effect of inhaled nitric oxide on pulmonary function in cystic fibrosis

Concentrations of nitric oxide (NO) have been found to be reduced in both the upper and lower airway of patients with cystic fibrosis (CF). As NO modulates bronchomuscular tone, low NO levels may contribute to the obstructive lung disease in these patients. To assess whether increasing inspiratory NO concentrations has any impact on lung function, we have studied 13 CF patients aged 14-38 years in a clinically stable condition and nine healthy controls. NO was applied via a mixing chamber for 5 min with NO concentrations of 100 parts per billion, 1 and 40 parts per million. Spirometry was performed at baseline and after inhalation on each occasion. There were no clinical side-effects at any NO concentration and no changes in oxygen saturation were observed. Lung function remained unchanged in all subjects throughout the study period. Sputum nitrate and nitrite concentrations before and after inhalation of high NO concentrations (40 ppm) in eight CF patients did not show any significant changes, even though a tendency to higher nitrate levels was observed (399 +/- 231 vs. 556 +/- 474 mumol l-1). Therefore, inhaled NO at either the physiological levels present in the upper airway of normal individuals or those used therapeutically to treat pulmonary hypertension has no immediate effect on bronchomuscular tone in patients with cystic fibrosis.

A pilot study on the clinical efficacy of Solanum xanthocarpum and Solanum trilobatum in bronchial asthma

Solanum xanthocarpum and Solanum trilobatum are widely used to treat respiratory diseases in southern Indian traditional medicine (Siddha). A pilot study was undertaken to investigate the clinical efficacy and safety of a single dose of the above herbs in mild to moderate bronchial asthma. The respiratory functions (FVC, FEV1, PEFR and FEF25-75%) were assessed by using a spirometer prior to and 2 h after oral administration of 300 mg powder of whole plant of either S. xanthocarpum or S. trilobatum. Standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg) were used for comparison. Treatment with either S. xanthocarpum or S. trilobatum significantly improved the various parameters of pulmonary function in asthmatic subjects. However, the effect was less when compared to that of deriphylline or salbutamol. No untoward effects were reported during the study. The results of the present study confirm the traditional claim for the usefulness of these herbs in bronchial asthma. More detailed studies are required to investigate the mechanism of action and therapeutic utility of S. xanthocarpum and S. trilobatum.

Effect of low-dose beclomethasone dipropionate on asthma control and airway inflammation

The effects of usual or low doses of inhaled corticosteroids on airway mucosal inflammation have not yet been examined. We therefore, compared the effects of inhaled beclomethasone dipropionate (BDP) 336 microg x day(-1) on asthma control outcomes and markers of airway inflammation. Twenty-four adult subjects with mild and moderate asthma were randomized to receive either BDP or placebo for four weeks; then subjects entered a single blind four week placebo run-in period. We found that the BDP group had significantly greater improvements in forced expiratory volume in one second (FEV1), morning peak flow, and rescue salbutamol use than the placebo-treated group. The improvement in FEV1 largely reversed one week after treatment was stopped. The decrease in the median percentage of eosinophils in induced sputum in the BDP group from 3.8% to 3.4% was not significant, but because eosinophils increased from 8.4% to 12.7% in the placebo group, there was a significant difference between treatment groups (p=0.03). There was no significant difference between groups during treatment in the levels of eosinophil cationic protein (ECP), tryptase mucin-like glycoprotein, or fibrinogen in induced sputum. The change in FEV1 in the BDP group did not correlate significantly with the change in eosinophil percentage or ECP levels. We concluded that four weeks of treatment with inhaled beclomethasone dipropionate 336 microg x day(-1) was associated with significant improvements in peak flow, forced expiratory volume in one second, and rescue salbutamol use in asthmatic subjects but was not associated with large reductions in markers of eosinophilic inflammation, bronchovascular permeability, or mucus hypersecretion.

Ozone responsiveness in smokers and nonsmokers

Short-term exposure to ozone causes decrements in lung function, but predictors of responsiveness remain largely unknown. Ninety healthy volunteers (56 never-smokers, age [mean +/- SD] 25 +/- 4 yr; 34 current smokers, 13 +/- 9 pack-yr, age 28 +/- 1 yr) were exposed to 0.22 ppm ozone for 4 h, with exercise, in an environmental chamber. We measured spirometry and specific airway conductance before, during, and immediately after exposure, and assessed symptoms by questionnaire. Smokers experienced a smaller increase in respiratory symptoms following exposure to ozone than did nonsmokers. Decrements in FEV1 were significantly less than for smokers than for nonsmokers (p = 0.0013). Ozone responsiveness (> 15% fall in FEV1) occurred in 16 of 56 never-smokers (28.6%) and 4 of 34 smokers (11.8%). Multiple logistic regression analysis found pack-yr of smoking to be associated with decreased ozone responsiveness (odds ratio [OR] 0.87, p = 0.017). Age, gender, and methacholine responsiveness were not predictive of responder status. Fourteen smokers and 25 nonsmokers were subsequently exposed once to air and twice to ozone; smokers as well as nonsmokers were consistent in their subsequent responsiveness (or lack of responsiveness) to ozone. Healthy smokers have smaller decrements in lung function and fewer symptoms in response to ozone exposure than do nonsmokers.

Effects of cigarette smoking on lung function in adolescent boys and girls

BACKGROUND

Little is known about the sex-specific effects of cigarette smoking on the level and growth of lung function in adolescence, when 71 percent of people in the United States who smoke tried their first cigarette.

METHODS

We studied the effects of cigarette smoking on the level and rate of growth of pulmonary function in a cohort of 5158 boys and 4902 girls 10 to 18 years of age, examined annually between 1974 and 1989 in six cities in the United States.

RESULTS

We found a dose-response relation between smoking and lower levels of both the ratio of forced expiratory volume in one second to forced vital capacity (FEB1/FVC) and the forced expiratory flow between 25 and 75 percent of FVC (FEF25-75). Each pack per day of smoking was associated with a 3.2 percent reduction in FEF25-75 for girls (P=0.01) and a 3.5 percent reduction in FEF25-75 for boys (P=0.007). Whereas the FVC level was elevated in smokers, the rate of growth of FVC and FEV1 was reduced. Among adolescents of the same sex, smoking five or more cigarettes a day, as compared with never smoking, was associated with 1.09 percent slower growth of FEV1 per year in girls (95 percent confidence interval 0.70 to 1.47) and 0.20 percent slower growth in boys (95 percent confidence interval, -0.16 to 0.56), and with 1.25 percent slower growth of FEF25-75 per year in girls (95 percent confidence interval 0.38 to 2.13) and 0.93 percent slower growth in boys (95 percent confidence interval, 0.21 to 1.65). Whereas girls who did not smoke reached a plateau of lung function at 17 to 18 years of age, girls of the same age who smoked had a decline of FEV1 and FEF25-75.

CONCLUSION

Cigarette smoking is associated with evidence of mild airway obstruction and slowed growth of lung function in adolescents. Adolescent girls may be more vulnerable than boys to the effects of smoking on the growth of lung function.

Acute safety and effects on mucociliary clearance of aerosolized uridine 5'-triphosphate +/- amiloride in normal human adults

Impaired mucociliary clearance contributes to the pathophysiology of several airways diseases including cystic fibrosis, asthma, and chronic bronchitis. Extracellular triphosphate nucleotides (adenosine 5'-triphosphate [ATP], uridine 5'-triphosphate [UTP]) activate several components of the mucociliary escalator, suggesting they may have potential as therapeutic agents for airways diseases. We conducted initial (Phase I) studies of acute safety and efficacy of aerosolized UTP alone and in combination with aerosolized amiloride, the sodium channel blocker, in normal human volunteers. Safety was assessed by measurement of pulmonary function. Neither UTP alone nor in combination with amiloride caused any clinically significant adverse effects on airway mechanics, (subdivisions of) lung volumes, or gas exchange. Acute efficacy of UTP and amiloride alone and in combination, was assessed by measuring changes in the clearance of inhaled radiolabeled particles. A 2.5-fold increase in mucociliary clearance was seen in response to UTP alone and in combination with amiloride. We conclude that aerosolized UTP +/- amiloride clearly enhances mucociliary clearance without acute adverse effects in normal adults, and may have therapeutic potential to enhance airways clearance in diseases characterized by retained airways secretions.

The effects of albuterol on the lung function of hospitalized patients with cystic fibrosis

Twenty-four hospitalized patients with cystic fibrosis were enrolled into a 2-d, double-blind, placebo-controlled, randomized crossover trial comparing albuterol inhalation aerosol with a saline placebo. Aerosols were administered with the first three of four chest physiotherapy sessions given 4 h apart. Spirometry was measured before and 45 min after 7:00 A.M. and 3:00 P.M. therapy and before therapy at 7:00 P.M. and 7:00 A.M. the next morning. The mean percent change in FVC, FEV1, and FEF25-75% at 7:00 A.M. was 10.7, 14.8, and 19.6% with albuterol versus 2.4, 1.0, and -0.8% with placebo (p = 0.0012, < 0.0001, and = 0.003, respectively). A greater than 8% change in FEV1 separated changes with albuterol versus placebo with 96% specificity and occurred in 75% of all patients with albuterol; 71% at 7:00 A.M. versus 24% at 3:00 P.M. The reduction in response at 3:00 P.M. (p < 0.01) was presumably due to prolonged effects of morning therapy ( > 4 h). Individual changes in spirometry were significantly more positive and homogeneous with albuterol versus placebo at both 7:00 A.M. and 3:00 P.M. The mean percent change for the FVC, FEV1, and FEF25-75 across the day (7:00 A.M. pretherapy to 7:00 P.M. pretherapy) was 8.1, 10.1, and 9.7% with albuterol versus 3.9, 3.5 and 2.6% with placebo (p = 0.029, 0.036, and 0.232, respectively). The more positive and homogeneous changes in spirometry with albuterol, along with greater changes in these measures across the day when compared with placebo, suggest that albuterol improves pulmonary function in a majority of hospitalized patients with cystic fibrosis.

Surfactant nebulization does not alter airflow obstruction and bronchial responsiveness to histamine in asthmatic children

To test the hypothesis that surfactant nebulization improves pulmonary function and reduces bronchial responsiveness to histamine, we studied 12 children with asthma. We measured before and after inhalation of 100 mg nebulized natural-derived bovine surfactant (Alveofact (registered)) and after nebulization of 0.9% NaCl the change in peak expiratory flow, vital VC, FEV1, and forced expiratory flows at 50 and 75% of the flow-volume curve. In addition, we performed a histamine inhalation challenge. We did not find any significant changes in these parameters after nebulization of surfactant. These findings indicate that the inhalation of nebulized surfactant does not alter airflow obstruction and does not alter bronchial responsiveness to histamine in asthmatic children with airflow obstruction.

Are asthma-like symptoms due to bronchial or extrathoracic airway dysfunction?

Patients with asthma-like symptoms may not have asthma but obstruction of the extrathoracic airway (EA). To evaluate if dysfunction of the EA causes asthma-like symptoms, we assessed bronchial and EA responsiveness to inhaled histamine in 441 patients who presented with at least one of three key symptoms--cough, wheeze, dyspnoea--but had neither documented asthma nor bronchial obstruction. The histamine concentrations causing a 20% fall in forced expiratory volume in 1 s (PC20FEV1) and a 25% fall in maximal mid-inspiratory flow (PC25MIF50) were used as respective thresholds of bronchial and EA responsiveness. Values 8 mg/mL or less indicated bronchial (B-HR) or EA hyper-responsiveness (EA-HR). The influence of concurrent upper respiratory tract diseases, such as post-nasal drip (PND), pharyngitis, laryngitis and sinusitis, was also assessed. We found four response patterns to the histamine challenge: EA-HR in 26.5% of the patients, B-HR in 11.1%, combined EA-HR and B-HR in 40.6%, and no-HR in 21.8%. Cough was reported by 79% of the patients, wheeze by 53%, and dyspnoea by 40%. Patients with cough as the sole presenting symptom (34.2%), as compared with those with wheeze and/or dyspnoea (20%), had significantly greater probability of having EA-HR (OR 5.35, 95% CI 3.25-8.82) and lower probability of having B-HR (OR 0.45, CI 0.28-0.70); patients with cough plus wheeze and/or dyspnoea (45.8%) had significantly greater probability of having both EA-HR and B-HR than either those with cough alone (OR 2.48, CI 1.49-4.13), or those with wheeze and/or dyspnoea but not cough (OR 1.74, CI 1.36-2.22). EA-HR alone or combined with B-HR was strongly associated with EA diseases, particularly pharyngitis and PND. Cough was significantly associated with PND, either when it was the sole symptom (OR 2.16, CI 1.14-4.09) or when it was combined with wheeze and/or dyspnoea (OR 3.53, CI 1.97-6.33). Our results suggest that extrathoracic airway dysfunction may account for asthma-like symptoms, particularly chronic cough. This abnormality seems to be sustained by chronic diseases of the upper respiratory tract.

Comparison of the bronchodilatory effects of cetirizine, albuterol, and both together versus placebo in patients with mild-to-moderate asthma

BACKGROUND

Many potential users of the H1 antihistamine cetirizine are asthmatic and may be using inhaled albuterol. This study was conducted to assess the possible bronchodilatory effect of cetirizine in patients with mild-to-moderate asthma and to determine whether cetirizine interacts with albuterol.

METHODS

In a randomized, double-blind, placebo-controlled, crossover study, the effects on pulmonary function of 5, 10, and 20 mg oral doses of cetirizine with and without inhaled albuterol (180 micrograms) were determined in 12 patients at 11 time points over 8 hours. The primary measure of efficacy was forced expiratory volume in 1 second (FEV1).

RESULTS

Cetirizine with or without albuterol significantly increased FEV1, peak expiratory flow rate, and forced expiratory flow rate between 25% and 75% of vital capacity relative to baseline and placebo but did not have a significant effect on forced vital capacity. The effect of 20 mg of cetirizine on FEV1 was generally greater than that of 10 or 5 mg, but the difference was statistically significant only at the 30-minute time point (p < 0.05). All three cetirizine doses produced significantly greater increases than placebo in FEV1 and forced expiratory flow rate between 25% and 75% of vital capacity for 8 hours and in peak expiratory flow rate for 7 hours (p < 0.02). Albuterol alone had a significant effect on the four pulmonary function variables from 1 to 5 hours after baseline (p < 0.05), which is consistent with albuterol's recommended dosing frequency of every 4 to 6 hours. Albuterol alone increased FEV1 significantly more than 5 mg of cetirizine alone but not 10 mg or 20 mg of cetirizine alone at 60, 90, and 120 minutes after baseline, but all three doses of cetirizine increased FEV1 significantly more than albuterol 7 and 8 hours after baseline (p < 0.05), indicating that the bronchodilatory action of cetirizine lasts longer than that of albuterol. Cetirizine neither potentiated nor inhibited the bronchodilatory action of albuterol, but the two drugs appeared to have an additive bronchodilatory effect. None of the cetirizine treatments caused a worsening of pulmonary function, and all were well tolerated.

CONCLUSIONS

Cetirizine has a significant bronchodilatory effect in patients with mild-to-moderate asthma and can be used to treat concomitant conditions (e.g., allergic rhinitis) without concern that it will interfere with the bronchodilatory effect of albuterol or cause worsening of asthma by itself.

Response to acute ozone exposure in healthy men. Results of a screening procedure

We screened 64 healthy, nonsmoking men, 18 to 35 yr old, for their sensitivity to 0.35 ppm ozone (O3) administered for 130 to 150 min with intermittent exercise. The changes in FVC, FEV1, AND FEF25-75 (p < 0.0001) immediately after O3 exposure varied widely among subjects. Histograms of the percentage changes in FVC and FEV1 did not differ from a unimodal, skewed (gamma) distribution (p = 0.99 and p = 0.17, respectively); the changes in FEF25-75 tended to deviate from a gamma distribution (p = 0.055). To adjust FEF25-75 for the confounding effects of O3 on FVC, we used multiple linear regression analysis with contemporaneous FVC as a covariable, analysis of a subgroup of nine subjects whose O3-induced FVC changes were < or = 5%, and volume correction of FEF25-75 for any changes in FVC after exposure. These analyses showed reductions in FEF25-75 unexplained by and following a different time course than the O3-induced changes in FVC. In 26 subjects also exposed to filtered air, significant effects of O3 on respiratory frequency (p < 0.004) and tidal volume (p < 0.0007) correlated weakly with FVC changes. The results confirm the wide variability in spirometric responsiveness among individuals to O3 and suggest that intrinsic narrowing of the small airways may be a significant component of the functional response.

Formaldehyde exposure, acute pulmonary response, and exposure control options in a gross anatomy laboratory

Formaldehyde exposure, acute pulmonary response, and exposure control options were evaluated in a group of 34 workers in a gross anatomy laboratory. Time-weighted average (TWA) exposure to formaldehyde ranged from 0.07-2.94 parts per million (ppm) during dissecting operations. More than 94% were exposed to formaldehyde in excess of the ceiling value of 0.3 ppm recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). The eight-hour TWA exposure of 31.7% of the subjects exceeded the action level of 0.5 ppm set by the Occupational Safety and Health Administration (OSHA). Reported symptoms included irritation of eye (88%), nose (74%), throat (29%), and airways (21%). Forced vital capacity (FVC) and forced expiratory volume in 3 seconds (FEV3) decreased, and FEV1/FVC increased during the exposure. The changes of FEV3 were statistically different from those of the controls. The results strongly support the necessity for designing and testing special local exhaust-ventilated worktables with necessary flexibility for dissecting operations.

In chronic obstructive pulmonary disease, a combination of ipratropium and albuterol is more effective than either agent alone. An 85-day multicenter trial. COMBIVENT Inhalation Aerosol Study Group

Combination bronchodilator therapy for chronic obstructive pulmonary disease (COPD) is available widely throughout the world except in North America. Previous studies have yielded conflicting results regarding the advantages of combining anticholinergic therapy with sympathomimetic therapy in COPD. We report the results of a 12-week prospective, double-blind, parallel-group evaluation of the use of the following: albuterol, a beta-adrenergic agent; ipratropium, an anticholinergic agent; or a combination of the two, administered by metered-dose inhaler to patients with moderately severe stable COPD. Following baseline studies, 534 patients were given one of the three test bronchodilator preparations to be used at home four times daily in addition to oral theophylline and corticosteroids as required. The doses of the latter two drugs were kept stable. Subjects were tested on days 1, 29, 57, and 85. Analysis of 1-s forced expiratory volume (FEV1) curves on those test days indicated that the combination was superior to either single agent alone in peak effect, in the effect during the first 4 h after dosing, and in the total area under the curve of the FEV1 response. The mean peak percent increases in FEV1 over baseline on the four test days were 31 to 33 percent for the combination, 24 to 25 percent for ipratropium, and 24 to 27 percent for albuterol. The differences between the combination and its components were statistically significant on all test days. The AUC0-4 means for the combination were 21 to 44 percent greater than the ipratropium means and 30 to 46 percent greater than the albuterol means. Similar changes were noted in the forced vital capacity curves. Symptom scores did not change over time and did not differ among the treatment groups. We conclude that the combination of ipratropium and albuterol, when given by metered-dose inhaler to patients with COPD, is more effective than either of the two agents alone. The advantage of the combination is apparent primarily during the first 4 h after administration. The availability of combination therapy by metered-dose inhaler should help to improve patient compliance.

Utility of inhaled pentamidine prophylaxis in lung transplant recipients

The incidence of Pneumocystis carinii pneumonia (PCP) has been shown to be high posttransplantation in the absence of prophylaxis. For this reason, lung transplant recipients routinely receive prophylaxis. We report on our results using aerosolized pentamidine prophylaxis in nine patients post-lung transplantation (eight single lung transplants, one double). The patients received monthly treatments of 300 mg of aerosolized pentamidine for a mean of 10.6 months (range, 4 to 21 months). Patients were routinely monitored with serial pulmonary function studies and bronchoscopy as clinically indicated. Two of the patients experienced bronchospasm in response to the therapy. None of the patients experienced any episodes of PCP during the period of inhaled pentamidine prophylaxis. Inhaled pentamidine is a safe and effective form of PCP prophylaxis and may be used instead of sulfamethoxazole-trimethoprim in patients who have a sulfa allergy or other untoward sulfa side effects.

Unspecific bronchial reactivity to carbachol in healthy subjects--effect of age and smoking habits

Chronic inflammatory processes of the airways induced by long-time cigarette consumption are a crucial factor in the pathogenesis of chronic obstructive pulmonary disease. In contrast, the role of cigarette smoking in the pathogenesis of bronchial hyperreactivity (BHR) is still unclear. The aim of this study was to assess the effect of chronic cigarette consumption on pulmonary function tests and BHR in healthy subjects. 63 healthy smokers and 63 lifetime nonsmokers matched for sex, age, height and weight were evaluated. Pulmonary function was determined by body plethysmography and spirometry. Bronchial provocation was performed by inhalation of increasing doses of carbachol (up to 25 g/l) in isotonic NaCl solution. Pulmonary function tests were within normal limits in all subjects. Nevertheless, midexpiratory flow at 25% of forced vital capacity was significantly smaller, and functional residual capacity was significantly greater in middle-aged smokers (age: 40-60 years) compared to middle-aged nonsmokers (p < 0.05, both comparisons). In young smokers and nonsmokers (age: 20-30 years) pulmonary function tests were not different (p > 0.28, all comparisons). Importantly, the carbachol concentration that provoked a 50% rise in specific airway resistance (PD50sRaw) was similar in smokers and nonsmokers of both age groups (p > 0.05, both comparisons) and did not correlate with the age of the subjects (p > 0.2). No correlations between baseline values of pulmonary function tests and PD50sRaw were observed (p > 0.34, all comparisons). The observations confirm that the distribution profile of BHR is unimodal and apparently not affected by age and smoking habits.

Pulmonary function in symptom-free asthmatics

Seventy-five adult asthmatic patients with clinical remission underwent spirometry. Only 8.3% of the subjects demonstrated normal spirometry. The others had reduced vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1), maximum mid-expiratory flow rate (MMF) and peak flow rate (PEFR). This study demonstrates that asthma can cause irreversible airflow obstruction and there is a poor relationship between symptoms in asthmatics and their respiratory function test results.

[The bronchodilator agent, Ventodisk, in the powdered inhalation form without freon is better]

The authors compared the effectiveness and advantages of the powdered inhalation variety of the preparation Ventodisc (Glaxo) with the "classical" dosed inhalation form of Salbutamol (Polfa) in 21 patients with bronchial asthma. During administration of 0.2 mg of the two drugs various conditions (mastering of the inhalation technique, elimination of the action of other drugs and the same time of day when the drug was administered) was respected. Values of ventilation parameters of the central and peripheral respiratory pathways before administration of the drugs did not differ significantly. The powdered form of salbutamol--Ventodisc (Glaxo) had a greater dilatating action than the classical dosed aerosol form--Salbutamol (Polfa) because: 1. in FEV1 values between rest and Ventodisc (1.47 l and 1.73 l) differed significantly, however, after subsequent inhalation of Salbutamol no further significant improvement occurred (1.79 l); 2. when the sequence of stimuli was reversed a significant increase of the FEV1; value occurred after Salbutamol (from 1.50 l to 1.67 l, p < 0.004) but Ventodisc caused a further significant increase (p < 0.0006). The tolerance of both drugs was equal. The powdered inhalation form of Salbutamol (Ventodisc--Glaxo) was better than the "classical" dosed aerosol form of salbutamol (Salbutamol--Polfa) as it had a greater dilatating effect in the central airways and moreover did not contaminate the environment.

Effects of aerosol methacholine and histamine on airways and lung parenchyma in healthy humans

To investigate whether histamine (His) and methacholine (MCh) have different effects on airways and lung parenchyma, 11 healthy subjects were given aerosol MCh until a response plateau was obtained and then two doses of His. At the plateau, forced expiratory volume in 1 s and forced expiratory flow at 40% of vital capacity from partial flow-volume curves were reduced by 19 +/- 3 (SE) and 80 +/- 4%, respectively. Aerosol His decreased forced expiratory volume in 1 s by an additional 12 +/- 1% but left partial forced expiratory flow unchanged. The bronchodilator effect of deep inhalation, as inferred from the ratio of forced expiratory flow from maximal to that from partial flow-volume curves, increased after MCh and plateaued but decreased after His. Quasi-static transpulmonary pressure-volume area determined in seven subjects was unchanged after MCh but was increased by 57 +/- 10% after His. We conclude that adding His after the response to MCh plateaued does not increase the maximal degree of bronchoconstriction but may increase parenchymal hysteresis, thus blunting the bronchodilator effect of deep inhalation. These results suggest that His and MCh have similar effects on airway smooth muscle but different effects on lung tissue properties.

Intrathecal morphine during thoracotomy, Part II: Effect on postoperative meperidine requirements and pulmonary function tests

The ability of intrathecal morphine (ITM) to reduce post-thoracotomy pain and meperidine requirements was investigated. Thirty adult patients scheduled for thoracic surgery were studied. Following induction with thiamylal sodium and succinylcholine, anesthesia was maintained with 100 micrograms of fentanyl, vecuronium, and enflurane. Prior to skin incision, 16 patients received intrathecal morphine, 12 micrograms/kg, injected at the L3-4 or L4-5 level. The other 14 patients were controls. Postoperatively, patients were evaluated for pain scores and the total doses of meperidine required over 24 hours. The patients in the ITM group required significantly less meperidine compared to the control group (59 +/- 68 v 167 +/- 97 mg, respectively) and had lower pain scores (1.4 +/- 1.1 v 2.4 +/- 0.9 mg, respectively). There were no serious side effects attributable to ITM. It is concluded that ITM is an effective adjunctive treatment for control of post-thoracotomy pain.

Preliminary study on the effect of broxaterol on bronchial hyperresponsiveness in asthmatic children: influence of allergen exposure

Increased bronchial hyperresponsiveness (BHR) has been reported in adult asthmatic patients after regular treatment with beta 2-agonists. In this study we evaluated the effect of a 4-weeks treatment period with broxaterol, a new beta 2-agonist, on BHR in asthmatic children living in two different environmental conditions. Two groups of patients, 24 domiciled at sea level, allergen exposed (group 1), and 24 resident at high altitude (Misurina, 1,756 m) in an allergen-free environment (group 2), have been tested. Children were randomly treated with broxaterol 400 micrograms q.i.d. or sodium chromoglycate 10 mg q.i.d. (as control treatment) by the metered dose inhaler for 4 weeks. Pulmonary function tests and methacholine challenge were performed at the beginning and at the end of the study. Throughout the study period a diary card was completed and peak expiratory flow rate (PEFR) was measured three times daily. Forty-two of the patients admitted concluded the study. No significant change was observed in the methacholine PC20 throughout the study period regardless of the type of treatment and/or environment. The amplitude percentage mean of diurnal changes in PEFR during the study period showed no statistically significant differences between treatments or centres, or in the interaction of treatment with centre, time with treatment, time with centre, time with centre and treatment (p > 0.05). Therefore in this pilot study regular treatment with broxaterol for 4 weeks did not cause an increase in BHR in asthmatic children both in conditions of allergen exposure and in an environment free of offending allergens.

Effects of steady-state and variable ozone concentration profiles on pulmonary function

Measurements of ambient ozone (O2) concentration during daylight hours have shown a spectrum of concentration profiles, from a relatively stable to a variable pattern usually reaching a peak level in the early afternoon. Several recent studies have suggested that in estimating exposure dose (O3 concentration [C] x exposure time [T] x ventilation [V]), O3 concentration needs to be weighted more heavily than either ventilation or duration of exposure in the estimates. In this study we tested the hypothesis that regardless of concentration pattern and exposure rate the same exposure dose of O3 will induce the same spirometric response. We exposed 23 healthy male volunteers (20 to 35 yr of age) for 8 h to air, 0.12 ppm O3 (steady-state), and a triangular exposure pattern (concentration increased steadily from zero to 0.24 ppm over the first 4 h and decreased back to zero by 8 h). During the first 30 min of each hour, subjects exercised for 30 min at minute ventilation (VE) approximately 40 L/min. The order of the exposures was randomized, and the exposures were separated by at least 7 days. The response patterns over the 8-h periods for spirometric variables in both O3 exposures were statistically different from air exposure changes and from each other. For FEV1 the p values were 0.017 between air and steady-state profile, 0.002 between air and triangular profile, and 0.037 between steady-state and triangular profiles. Although in the triangular pattern of exposure the maximal O3 concentration was reached at 4 h, the maximum FEV1 decrement (10.2%) was observed at 6 h of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between nonspecific bronchial responsiveness to methacholine and peripheral mononuclear leukocyte beta-adrenergic receptor function in young drug-naive subjects

Asthma is associated with dysfunction of the beta-adrenergic receptor adenylyl cyclase signal transduction pathway. It has been argued that this results from receptor down-regulation by beta-agonist therapy. This study examined the relationship between nonspecific bronchial responsiveness (NSBR) to methacholine (Newcastle dosimeter method) and beta-adrenergic receptor density (Bmax) and affinity (%KH) in membranes from peripheral blood mononuclear leukocytes (MNL) in 12 male (27.3 +/- 1.7 yr old) and 14 female (31.4 +/- 1.7 yr old) drug-naive subjects with and without symptoms of mild intermittent wheezing. None had ever smoked or received any antiasthma medication. "Hyperresponsive" subjects were defined as those (n = 11) whose simplified slope of FEF50 (calculated as the percent fall in FEF50 divided by the dose of methacholine) was more than one SD above the mean for asymptomatic subjects. The log of the slope was reproducible (repeatability coefficient = 0.43) on two nonconsecutive days. Multiple regression analysis (overall R2 = 0.57) revealed negative relationships between the log of the slope and both Bmax (p = 0.016) and %KH (p = 0.011). Analysis of variance confirmed a lower mean (+/- SEM) value of %KH in "hyperresponsives" (45.7 +/- 5.5%) than in "normoresponsives" (60.4 +/- 4.1%, p = 0.04) with a similar trend for Bmax (hyperresponsives = 33.5 +/- 4.1 fmol/mg, normoresponsives = 45.9 +/- 7.1 fmol/mg, p = 0.18). These relationships between bronchial responsiveness, Bmax, and %KH cannot be explained by drug therapy, and they provide further evidence that there is an intrinsic impairment in the function of beta-adrenergic receptors on peripheral MNLs from subjects with high levels of nonspecific bronchial responsiveness.

Effect of age on bronchodilator response

STUDY OBJECTIVE

Our objective was to compare the differential effects of age and drug type on bronchodilator response.

DESIGN

The design was an unblinded, randomized crossover study.

SETTING

An ambulatory pulmonary drug study unit was the setting.

PATIENTS

Nineteen young (18 to 25 yr) and 17 elderly (greater than 65 yr) stable asthmatic subjects were studied.

INTERVENTIONS AND MEASUREMENTS

Albuterol or ipratropium was given on two separate mornings using an MDI with extender. Subjects inhaled two puffs initially and then one puff every 30 min to a total of six puffs. Pulmonary function, blood pressure, and pulse were measured at baseline and every 30 min for 3 h.

RESULTS

All subjects had a greater than 15 percent increase in FEV1 with one or both drugs. More patients responded to albuterol than to ipratropium in both age groups. The maximum percentage of change from baseline was greater (p less than 0.05) with albuterol (mean, 40.1 percent in young and 60.5 percent in old) than with ipratropium (21.2 percent in young; 31.2 percent in old) in both groups. These differences remain significant after correction for baseline differences using area-under-the-curve analysis of the percent of maximum improvement; however, the differences between age groups for the same drug were not statistically significant by either index of change. There were also no differences between drugs or between age groups for time (or number of puffs) to reach maximum improvement (mean, 2.0 to 2.2 h for albuterol and 1.6 to 1.7 h for ipratropium). The changes in FVC and FEF25-75% were similar to FEV1. Changes in blood pressure and pulse were not significant. Three subjects stopped therapy with albuterol with side effects.

CONCLUSIONS

Both drugs are effective bronchodilators in young and old asthmatic subjects, but albuterol results in a greater magnitude of response in both age groups. Age is not a predictor of response to either drug.