Search

Study Objective: To quantify lung oxidative stress in asthmatic children by measuring concentrations of 8-isoprostane, a marker of oxidative stress, in exhaled breath condensate (EBC), which is a noninvasive method of sampling airway secretions. Secondary objectives were as follows: (1) to measure levels of exhaled prostaglandin (PG) E(2), since impaired PGE(2) production has been implicated in the pathogenesis of asthma in adults; and (2) to measure levels of fractional exhaled nitric oxide (FeNO), which is a marker of airway inflammation., Design: Single-center, cross-sectional study., Patients: Twelve healthy children, 12 steroid-naïve asthmatic children, and 30 children in stable condition with mild-to-moderate persistent asthma who were being treated with inhaled corticosteroids (ICSs) [average dose, 300 micro g per day] were studied., Interventions: Subjects attended the outpatient clinic on one occasion for the collection of EBC and FeNO measurements., Measurements and Results: 8-Isoprostane and PGE(2) concentrations in EBC were measured with specific radioimmunoassays. FeNO was measured online by a chemiluminescence analyzer. 8-Isoprostane was detectable in the EBC of healthy children (mean [+/- SEM], 34.2 +/- 4.5 pg/mL), and its concentrations were increased in both steroid-naïve asthmatic children (mean, 56.4 +/- 7.7 pg/mL; p < 0.01) and steroid-treated asthmatic children (mean, 47.2 +/- 2.3 pg/mL; p < 0.05). There was no difference in exhaled 8-isoprostane concentrations between the two groups of asthmatic children (p = 0.14). By contrast, exhaled PGE(2) concentrations were similar among the three study groups (p = 0.56). FeNO levels were higher in steroid-naïve children with asthma (49.2 +/- 9.6 parts per billion [ppb]; p < 0.05) and, to a lesser extent, in steroid-treated asthmatic children (37.8 +/- 6.6 ppb; p < 0.05) compared with healthy children (15.2 +/- 1.7 ppb)., Conclusions: Lung oxidative stress is increased in children who are in stable condition with asthma, as reflected by increased exhaled 8-isoprostane concentrations. This increase seems to be relatively resistant to treatment with ICSs. Decreased PGE(2) lung production is unlikely to play a pathophysiologic role in childhood asthma.

Background: Exhaled breath condensate (EBC) is a rapidly expanding area of research to study airway inflammation through the detection of volatile and non-volatile substances in the airways., Aims: To determine the safety and feasibility of EBC procedure in a group of children with asthma of varying severity., Methods: In a cross sectional study of children aged 4-17 years, 18 healthy and 91 asthmatic children (69 in stable condition and 22 with asthma exacerbation) underwent the EBC procedure. Outcomes assessed included completion of the procedure, decrease in FEV1, change in fractional exhaled nitric oxide (FE(NO)), and adverse effects. No pretreatment with beta2 agonists was given. All children were able to successfully complete the EBC procedure., Results: Median fall in FEV1 after the procedure was -1% (IQR -3.5, 1.8) in asthmatics and was comparable to that observed in healthy children. In only one asthmatic child did the drop in FEV1 exceed 12%. No significant changes in FE(NO) were observed after EBC., Conclusion: This study suggests that EBC is a simple and well tolerated method for evaluating biological samples from the lower airway. The procedure was safe in children with asthma exacerbation, and the success rate was 100% in children aged 4 years and above.

The aim of this prospective, self-controlled, single-blind study was to assess the effect of montelukast added to maintenance therapy with inhaled corticosteroids (ICS) on fractional exhaled nitric oxide (FENO) in asthmatic children. Thirty-five children (age 11.2+/-0.4 yrs (mean+/-SEM)) with mild-to-moderate persistent asthma treated with low to medium doses of ICS and FENO > 20 parts per billion (ppb) were included. The patients were randomly assigned to two groups: 17 patients continued ICS (group C) and 18 had montelukast added to ICS for 3 weeks (group M). FENO measurements were performed in both groups at baseline (T1) and after 3 weeks (T2), and in group M also after 2 weeks of washout. FENO was measured by a chemiluminescence analyser using an on-line method (50 mL x s(-1)) with nitric oxide-free air. The overall mean daily dose of ICS was equivalent to 530+/-58 microg x day(-1) of beclomethasone in group M and to 564+/-55 microg x day(-1) of beclomethasone in group C. There were no significant differences in baseline FENO and forced expiratory volume in one second (FEV1) between the two groups. After 3 weeks there was a significant reduction of FENO values in patients of group M (T1 52.2+/-7.8 ppb, T2 36.1+/-4.6 ppb) but no significant changes in group C (T1 43.5+/-6.0 ppb, T2 47.8+/-9.4 ppb). In group M after 2 weeks of montelukast withdrawal, FENO rose to baseline values (55.6+/-8.7 ppb). In conclusion, after montelukast treatment there is a fractional exhaled nitric oxide reduction in asthmatic children receiving maintenance therapy with inhaled corticosteroids. This suggests an anti-inflammatory effect of montelukast additive to that of inhaled corticosteroids.

Purpose: To investigate the gene expression and tissue distribution of prepro Endothelin-1 (ET-1), Endothelin Converting Enzyme (hECE-1), and ETA and ETB receptors in the central (CZ), transition (TZ) and peripheral (PZ) zones of normal human prostates., Materials and Methods: Sections of the different zones of histologically normal prostates from 35 year-old men were obtained and autoradiographically studied with 125I ET-1 with and without the ETA antagonist BQ-123, the ETB agonists sarafotoxin 6C, and excess cold ET-1. Specimens from PZ and CZ and DU145 and PC3 human prostate cancer cell lines were also investigated by reverse transcription (RT)-PCR., Results: The mRNAs of all genes were detected in all specimens examined. No ETB expression was found in either cell lines. Specific intense 125I ET-1 binding with clear-cut differences among zones was found. In the CZ the main subtype in the glandular stroma and epithelium was the ETA and ETB, respectively, in the PZ the opposite was true. In PZ, the ETA receptors were detected on the glandular epithelium; in the TZ both receptor subtypes were only in the stroma., Conclusions: These receptors' zonal distribution differences may be relevant for the pathogenesis of BPH and prostatic cancer.