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Oxide Measurement (oxide + measurement)

Distribution by Scientific Domains
Medical Sciences100%

Kinds of Oxide Measurement

  • nitric oxide measurement
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    Selected Abstracts

    Comparability of a hand-held nitric oxide analyser with online and offline chemiluminescence-based nitric oxide measurement

    PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 7 2009
    Barbara Schiller
    Practicability is crucial for successful implementation of fractional exhaled nitric oxide (FeNO) measurement into asthma management. The study aimed at comparing a conventional chemiluminescence NO analyser (EcoMedics®) with a hand-held device (NIOX MINO®) and offline FeNO measurement using a commercially available system in an unselected cohort of children aged 6,16 yr. A secondary objective was to confirm FeNO stability over time in 15 samples from adult volunteers obtained using the offline system. Sixty-six children (mean ± s.d. age 11.8 ± 3.0 yr) underwent single breath FeNO measurement in triplets with each device. Offline collected FeNO was measured after offline breath collection into a Mylar balloon and subsequent analysis using the chemiluminescence NO analyser. Variability and between-method agreement were assessed, and stability over time within the Mylar balloons was tested by repeated hourly measurements. FeNO levels ranged from 2 to 113 p.p.b. Intra-class correlation was excellent (r = 0.98, p < 0.001 for each pair). Bland,Altman plots and back-transformation of logarithmic mean differences revealed fair agreement between methods. Stability over time was confirmed over 10 h both at room temperature and when stored under cooling conditions. FeNO values obtained using the chemiluminescence NO analyser, the portable NIOX MINO® system and the offline collection technique show between-method agreement within clinically acceptable range. [source]

    Methodological issues related to exhaled nitric oxide measurement in children aged four to six years

    PEDIATRIC PULMONOLOGY, Issue 2 2005
    Edward Napier MBBS
    Abstract This study was designed to test five methodological issues related to measurement of fractional exhaled nitric oxide (FENO) in children aged 4,6 years using commercially available apparatus. Participants attended two randomly selected schools. A respiratory questionnaire was completed. Measurements of FENO were made on successive days, using a NIOX® analyzer employing standard or modified methodologies. Ninety-one children participated in the study (mean age, 5.3 years; 46 boys). Using a standard methodology (n,=,61), FENO was successfully measured in 28 (46%) children, 1/12 aged 4 years, 12/25 aged 5 years, and 15/24 aged 6 years (trend test P,=,0.01). On the first assessment, FENO could be determined in more boys than girls (64% vs. 30%, respectively, P,=,0.008), but this gender difference was not apparent on the second assessment. Exhaled NO was reproducible over a 24-hr period; the mean difference between repeated measurements of natural log (ln) FENO was 0.016 parts per billion (ppb) (95% confidence limits, ,0.479, 0.511), n,=,20. Data from 35 assessments showed that values of FENO did not alter over nine individual, successive measurements. Use of a modified methodology in 30 children increased success in obtaining FENO, but these values were unreliable. In conclusion, measurements of FENO can be obtained in the majority of 5- and 6-year-old but not 4-year-old children. Exhaled NO measurements were reproducible over a 24-hr interval, and did not change over up to nine expiratory maneuvers in these young children. Pediatr Pulmonol. 2005; 40:97,104. © 2005 Wiley-Liss, Inc. [source]

    Disconnect between standardized field-based testing and mannitol challenge in Scottish elite swimmers

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 5 2010
    K. L. Clearie
    Summary Background Elite swimmers have high rates of rhinoconjunctivitis and exercise-induced bronchoconstriction. Moreover, exposure to chlorine and chlorine metabolites is known to induce bronchial hyper-reactivity. Objective To assess the early and late effects of chlorine and exercise on the unified airway of elite swimmers, and to compare the response to mannitol and field-based exercise challenge. Methods The Scottish national squad underwent exhaled tidal (FENO) and nasal (NNO) nitric oxide measurement, peak nasal inspiratory flow (PNIF), and forced expiratory volume in 1 s before, immediately after, and 4,6 h post-swimming. A sport-specific exercise test was carried out during an intensive lactate set (8 min at 80% maximum hear rate). All swimmers underwent mannitol challenge, and completed a health questionnaire. Results N=61 swimmers were assessed: 8/59 (14%) of swimmers had a positive mannitol challenge. Nine out of 57 (16%) of swimmers had a positive exercise test. Only one swimmer was positive to both. Swimmers with a positive mannitol had a significantly higher baseline FENO (37.3 vs. 18.0 p.p.b., P=0.03) than those with a positive exercise challenge. A significant decrease in FENO was observed pre vs. immediate and delayed post-chlorine exposure: mean (95% CI) 18.7 (15.9,22.0) p.p.b. vs. 15.9 (13.3,19.1) p.p.b. (P<0.01), and 13.9 (11.5,16.7) p.p.b. (P<0.01), respectively. There were no significant differences in NNO. Mean PNIF increased from 142.4 L/min (5.8) at baseline to 162.6 L/min (6.3) immediately post-exposure (P<0.01). Delayed post-exposure PNIF was not significantly different from pre-exposure. Conclusions No association was found between mannitol and standardized field-based testing in elite swimmers. Mannitol was associated with a high baseline FENO; however, exercise/chlorine challenge was not. Thus, mannitol may identify swimmers with a ,traditional' inflammatory asthmatic phenotype, while field-based exercise/chorine challenge may identify a swimmer-specific bronchoconstrictor response. A sustained fall in FENO following chlorine exposure suggests that a non-cellular, perhaps neurogenic, response may be involved in this group of athletes. Cite this as: K. L. Clearie, P. A. Williamson, S. Vaidyanathan, P. Short, A. Goudie, P. Burns, P. Hopkinson, K. Meldrum, L. Howaniec and B. J. Lipworth, Clinical & Experimental Allergy, 2010 (40) 731,737. [source]

    Exhaled air temperature in asthma: methods and relationship with markers of disease

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2007
    G. L. Piacentini
    Summary Background Exhaled breath temperature has been proposed as a surrogate marker for the evaluation of airway inflammation in asthmatic patients. Objective The aim of the present study was to extend the investigation of exhaled air temperature as a means for the evaluation of airway inflammation using a professionally developed instrument. Methods Fifty-seven children, 41 allergic mild asthmatics and 16 healthy controls have been evaluated. They underwent exhaled air temperature and lung function measurement. The asthmatic children also underwent exhaled nitric oxide measurement, and hypertonic saline sputum induction for the evaluation of eosinophil (EOS) percentage. Results The level of exhaled temperature was significantly higher in asthmatics than in controls, being 30.18±0.14°C vs. 27.47±0.24°C (P<0.001). In asthmatic children, a positive relationship was observed between exhaled air temperature and both exhaled nitric oxide (r=0.39; P=0.01) and EOS percentage in samples from induced sputum (,=0.53; P=0.04). Conclusion The data from the present study support the hypotheses that exhaled breath temperature is related to the degree of airway inflammation in asthma. [source]

    Nasal nitric oxide measurements before and after repeated humming maneuvers

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2003
    M. Maniscalco
    Abstract Background, It has been recently shown that humming greatly increases nasal nitric oxide (NO). This is most likely owing to a rapid washout of sinus NO caused by the oscillating sound waves. During repeated humming manoeuvres nasal NO gradually decreases, likely because NO accumulated in the sinuses is washed out. Aim, We studied whether humming before measurements would affect nasally exhaled NO. Materials and methods, NO output was measured by the chemiluminescence technique in orally and nasally exhaled air in 38 subjects: 18 healthy subjects (HS), 15 subjects with allergic rhinitis (AR) and five subjects with allergic nasal polyposis (AP). Each subject performed a NO measurement during quiet nasal exhalation either preceded by a period of silence/free speaking or immediately after five consecutive humming manoeuvres (posthumming). Results, Mean nasal NO output (95% CI) after a period of silence/free speaking was 231 nL min,1 (178,284) in HS, 434 nL min,1 (347,522) in AR (P < 0·001) and 262 nL min,1 (163,361) in AP. Post-humming nasal NO output was 16% (5 to 50%) lower in HS and 14% (1 to 49%) lower in AR, while it remained unchanged in AP subjects. Intra-subject coefficient of variation of quiet nasal exhalation was 12% in HS, 13% in AR and 5% in AP. Post humming intraindividual coefficient of variation significantly decreased in both HS and AR, but it did not change in AP. Conclusions, Nasal NO levels measured immediately after repeated humming manoeuvres are consistently lower and more reproducible than nasal NO levels measured after a period of silence or free speaking. Repeated humming effectively empties the sinuses, thereby probably minimizing the normal contribution from the sinuses to nasal NO. This may be useful to better estimate NO output from the nasal cavity mucosa in health and disease. [source]

    Reliability of a new hand-held device for the measurement of exhaled nitric oxide

    ALLERGY, Issue 10 2007
    B. Khalili
    Background:, Given the importance of airway inflammation in asthma, there has been an effort to incorporate inflammatory markers into its management. Measurement of fractional exhaled nitric oxide (FeNO) is a noninvasive marker of airway inflammation; however, the use of the available FeNO analyzer is limited by several factors including its cost and lack of transportability. The aim of this study was to compare the performance of a new hand-held FeNO measuring device (NIOX MINO) to the current clinical standard , the chemiluminescence FeNO analyzer (NIOX). Methods:, Subjects 6 years and older presenting to an allergy and asthma clinic underwent FeNO evaluation by NIOX and each of three NIOX MINOs. The mean of two acceptable measurements from the NIOX and the first approved measurement from each NIOX MINO were used for analysis. Results:, One hundred ten patients aged 6,86 years completed the study. Intrasubject FeNO levels obtained by each of the three NIOX MINOs revealed no significant difference between the measurements (P = 0.59). There was a very strong correlation between FeNO measurements by NIOX and by NIOX MINO (r = 0.98, P < 0.0001). The mean intrasubject FeNO difference between NIOX and NIOX MINO was ,0.5 p.p.b. which was not statistically significantly different from zero (P = 0.21). Conclusions:, Fractional exhaled nitric oxide measurements by the NIOX MINO showed a strong correlation and a high degree of agreement with the current standard stationary device. The NIOX MINO may be reliably used in clinical practice. [source]