scholarly journals Use of a vibrating mesh nebulizer for allergen challenge

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Donald W. Cockcroft ◽  
Beth E. Davis ◽  
Christianne M. Blais ◽  
Louis-Philippe Boulet ◽  
Marie-Éve Boulay ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Allergen Challenge ◽  
Skin Tests ◽  
Tidal Breathing ◽  
Geometric Means ◽  
Asthmatic Response ◽  
Acceptable Alternative ◽  
Jet Nebulizer ◽  
Allergen Inhalation ◽  
Methacholine Provocation

Abstract Background Allergen inhalation tests are a valuable research tool. The allergen dose producing an early asthmatic response (EAR) can be predicted from methacholine responsiveness and allergen skin test endpoint (STE). The Wright® jet nebulizer, which is both inefficient and increasingly difficult to obtain, has been used historically. We assessed the Solo® vibrating mesh nebulizer as an alternative for allergen and methacholine challenges. Methods Eighteen mild atopic asthmatics completed the study. Doubling concentration allergen prick skin tests were performed to determine the STE in allergen units/mL. The Wright® protocol was used to measure the methacholine provocation dose causing a 20% forced expired volume in one second (FEV1) fall (PD20) (μg) and the allergen PD20 (units). The Solo® protocol (0.5 mL nebulized to completion, tidal breathing inhalation) was used to determine both methacholine PD20 and allergen PD20. The nebulizer order was randomized and separated by ≥ 2 weeks. Results All data were log transformed. The allergen PD20, predicted from the methacholine PD20 and the STE, was within 2 doubling doses of the PD20 measured with the Wright® and 2.64 doubling doses of that measured with Solo®. The Wright® allergen PD20 correlated with the Wright® methacholine PD20 (r = 0.74) and the STE (r = 0.78) and more strongly with the product of the two (Wright® methacholine PD20 × STE, r = 0.91, p < 0.00001). The Solo® allergen PD20 showed similar relationships with the Solo® methacholine PD20 (r = 0.61), the STE (r = 0.75) and the product of the two (Solo® methacholine PD20 × STE, r = 0.83, p < 0.00002). The Wright® and the Solo® methacholine geometric mean PD20s were not significantly different (49.3 and 54.5 μg respectively, p = 0.62). The Wright® allergen PD20 was slightly but significantly lower than the Solo® allergen PD20 (geometric means 6.7 and 10.5 units respectively, p = 0.003). Conclusion The Solo® allergen PD20 showed the same relationship with methacholine responsiveness and STE as did the Wright®. The Solo® allergen PD20 was slightly but significantly higher than the Wright® allergen PD20. The Solo® vibrating mesh nebulizer was well tolerated and is an acceptable alternative for allergen challenge. Trial registration clinicaltrials.gov: NCT03491358

scholarly journals Protective Effects of Fluticasone on Allergen-Induced Airway Responses and Sputum Inflammatory Markers

2000 ◽  
Vol 7 (4) ◽  
pp. 313-319 ◽  
Author(s):  
Krishnan Parameswaran ◽  
Mark D Inman ◽  
Rick M Watson ◽  
Marilyn M Morris ◽  
Ann Efthimiadis ◽  
...  
Keyword(s):  
Single Dose ◽  
Protective Effect ◽  
Allergen Challenge ◽  
Airway Responsiveness ◽  
Protective Effects ◽  
Asthmatic Response ◽  
Sputum Eosinophilia ◽  
Late Asthmatic Response ◽  
Cell Counts ◽  
Allergen Inhalation

BACKGROUND:A direct comparison of the protective effects of single and regular doses of inhaled glucocorticoid on allergen-induced asthmatic responses and inflammation has not been made.OBJECTIVE:To compare the effects of pretreatment with fluticasone 250 µg 30 min before allergen inhalation and two weeks of 250 µg twice daily (last dose 24 h before challenge) with single and regular (twice daily) placebo doses on early and late asthmatic responses, induced sputum cell counts and measures of eosinophil activation at 7 h and 24 h, and methacholine airway responsiveness at 24 h.PATIENTS AND METHODS:Ten mild asthmatic patients were studied in a randomized, double-blind, placebo controlled crossover study.RESULTS:Regular fluticasone increased the baseline mean provocative concentration of methacholine to cause a 20% fall (PC20) in forced expiratory volume in 1 s (FEV1) from 2.6 to 6.4 mg/mL (P<0.05) and lowered the eosinophil count from 3.1% to 0.4% (P<0.05) compared with regular placebo. Neither single nor regular fluticasone had any effect on the early asthmatic response. Single fluticasone attenuated the late asthmatic response, the mean ± SEM maximum percentage fall in FEV1(10.8±3.6 compared with single placebo 18.8±3.5, P=0.03), the allergen-induced increase of airway responsiveness (P<0.05), and the eosinophilia (P<0.005) and activated eosinophils at 7 h (P<0.01) but not at 24 h. Regular fluticasone also attenuated the late asthmatic response (11.1±2.5) compared with regular placebo (19.6±4.5), but this was not statistically significant and did not protect against the induced increase in airway responsiveness or the sputum eosinophilia.CONCLUSION:Two weeks of regular inhaled fluticasone discontinued 24 h before allergen challenge does not offer any additional protection against the early or late asthmatic responses, increased airway responsiveness or sputum eosinophilia compared with a single dose of 250 µg immediately before allergen challenge, despite increasing baseline PC20and decreasing sputum eosinophilia prechallenge. The significance of the protective effect of a single dose of inhaled steroid before an allergen inhalation and the duration of the protective effect need further investigation.

scholarly journals Pharmacokinetic Interactions between the Hormonal Emergency Contraception, Levonorgestrel (Plan B), and Efavirenz

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Monica L. Carten ◽  
Jennifer J. Kiser ◽  
Awewura Kwara ◽  
Samantha Mawhinney ◽  
Susan Cu-Uvin
Keyword(s):  
Geometric Mean ◽  
Liver Function Tests ◽  
Open Label ◽  
Time Curve ◽  
Geometric Means ◽  
Concentration Time ◽  
Plan B ◽  
Effective Contraception ◽  
Grade 3 ◽  
Hiv Negative

Objectives. Compare the Plan B levonorgestrel (LNG) area under the concentration- time curve (AUC12) prior to and with efavirenz (EFV).Design. Prospective, open-label, single-arm, equivalence study.Methods. Healthy HIV-negative subjects underwent 12 hr intensive pharmacokinetic (PK) sampling following single dose LNG alone and after 14 days of EFV. Geometric means, Geometric Mean Ratios, and 90% confidence intervals (CI) are reported for PK Parameters.T-tests were utilized. Clinical parameters and liver function tests (LFTs) were assessed.Results. 24 women enrolled and 21 completed the study. With EFV, LNG AUC12was reduced 56% (95% CI: 49%, 62%) from 42.9 to 17.8 ng*hr/mL, and maximum concentration (Cmax⁡) was reduced 41% (95% CI: 33%, 50%) from 8.4 to 4.6 ng/mL. LNG was well tolerated with no grade 3 or 4 treatment-related toxicities.Conclusions. EFV significantly reduced LNG exposures. Higher LNG doses may be required with EFV. These results reinforce the importance of effective contraception in women taking EFV.

scholarly journals Analyzing Dependent Variables with Multiple Surrogates in Accounting Research

2018 ◽  
Author(s):  
Enyi Enyi
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Performance Studies ◽  
Geometric Mean ◽  
A Priori ◽  
Geometric Means ◽  
Canonical Correlations ◽  
Dependent Variables ◽  
Actual Outcome ◽  
Ethical Clearance

The paper contains details a research carried out to show that the use of geometric mean to unify multivariate dependent variables in financial performance studies gives better and more practical results than the multiple abstraction analysis provided using advanced econometric tools such as TLS, PLS, MCA, Canonical correlations etc.<div>The study used the logistic regression analysis to compare the a priori expectations of 30 Ph.D research theses with their actual outcomes using econometric tools and the actual outcome using geometric means. The study used Ph.D theses in accounting and finance sourced from the libraries of four universities in Nigeria.</div><div>The study was a desktop research using publicly available literary resources and as such requires no ethical clearance.</div>

scholarly journals Recognition of International Education in Japanese Teachers

2017 ◽  
Vol 5 (2) ◽  
pp. 53 ◽  
Author(s):  
Masami Yoshida
Keyword(s):  
International Education ◽  
School Environment ◽  
Geometric Mean ◽  
Intercultural Education ◽  
Multiple Comparison ◽  
Geometric Means ◽  
Suburban Areas ◽  
The Third ◽  
Questionnaire Method ◽  
Multiple Comparison Procedures

Education for international understanding in Japan was focused to develop its own national identity as well as to recognize its coexistence through intercultural education. Then, we have investigated the opinions of Japanese school teachers in terms of their recognition of the necessary content to introduce school instruction of intercultural education using a questionnaire method. In the questionnaire, 14 items of three principles were extracted from the criteria of UNESCO (United Nations Educational, Scientific, and Cultural Organization). For analyzing the collected data, the geometric mean was used. Subsequently, a one-way ANOVA test and multiple-comparison procedures were conducted. By including teachers in suburban areas in Japan, we obtained 123 valid responses. All items showed a necessary level of geometric means, and particularly items of the first principle “respect cultural identity” and items of the second principle “provide knowledge for participation” showed statistically significant positive necessity levels. However, an answer of “I have never thought” increased in the third principle “provide a chance to contribute” that was closely related to present world concern of global citizenship education and statistically was not significant. From the result of the multiple-comparison procedures of the second principle and the third principle, seven pairs of statistically different items were extracted. Then, we discussed the enhancement between Japan and UNESCO and influence of school environment in Japan.

scholarly journals A Comparison of the Arithmetic and Geometric Means in Estimating Stump Diameter, Basal Area, and Volume in Appalachian Hardwoods

2007 ◽  
Vol 24 (1) ◽  
pp. 71-73 ◽  
Author(s):  
Harry V. Wiant ◽  
John R. Brooks
Keyword(s):  
Geometric Mean ◽  
Basal Area ◽  
Cross Sectional Area ◽  
Practical Significance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Geometric Means ◽  
The Difference ◽  
Appalachian Hardwoods ◽  
Stump Diameter

Abstract The difference between the use of the arithmetic and geometric means for estimation of average stump diameter, stump cross-sectional area and estimated tree volume was investigated using measurements from 739 stumps from an Appalachian hardwood stand located in central West Virginia. Although average stump diameter, cross-sectional area, and tree volumes were statistically different between estimates based on the arithmetic and geometric mean diameter, these differences were of little practical significance. The difference in average stem diameter, cross-sectional area, tree cubic volume, and board foot volume were 0.05 in, 0.01 ft2, 0.45 ft3, and 2.41 bd ft, respectively.

scholarly journals Tobacco-Specific Nitrosamines (NNAL, NNN, NAT, and NAB) Exposures in the US Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013–2014)

2020 ◽  
Author(s):  
Baoyun Xia ◽  
Benjamin C Blount ◽  
Tonya Guillot ◽  
Christina Brosius ◽  
Yao Li ◽  
...  
Keyword(s):  
Solid Phase ◽  
Geometric Mean ◽  
Tobacco Product ◽  
Geometric Means ◽  
Population Assessment ◽  
Frequency Of Use ◽  
The Us ◽  
Liquid Chromatography Tandem Mass ◽  
Highly Correlated ◽  
Tobacco Specific Nitrosamines

Abstract Introduction The tobacco-specific nitrosamines (TSNAs) are an important group of carcinogens found in tobacco and tobacco smoke. To describe and characterize the levels of TSNAs in the Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013–2014), we present four biomarkers of TSNA exposure: N′-nitrosonornicotine, N′-nitrosoanabasine, N′-nitrosoanatabine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) which is the primary urinary metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Methods We measured total TSNAs in 11 522 adults who provided urine using automated solid-phase extraction coupled to isotope dilution liquid chromatography–tandem mass spectrometry. After exclusions in this current analysis, we selected 11 004 NNAL results, 10 753 N′-nitrosonornicotine results, 10 919 N′-nitrosoanatabine results, and 10 996 N′-nitrosoanabasine results for data analysis. Geometric means and correlations were calculated using SAS and SUDAAN. Results TSNA concentrations were associated with choice of tobacco product and frequency of use. Among established, every day, exclusive tobacco product users, the geometric mean urinary NNAL concentration was highest for smokeless tobacco users (993.3; 95% confidence interval [CI: 839.2, 1147.3] ng/g creatinine), followed by all types of combustible tobacco product users (285.4; 95% CI: [267.9, 303.0] ng/g creatinine), poly tobacco users (278.6; 95% CI: [254.9, 302.2] ng/g creatinine), and e-cigarette product users (6.3; 95% CI: [4.7, 7.9] ng/g creatinine). TSNA concentrations were higher in every day users than in intermittent users for all the tobacco product groups. Among single product users, exposure to TSNAs differed by sex, age, race/ethnicity, and education. Urinary TSNAs and nicotine metabolite biomarkers were also highly correlated. Conclusions We have provided PATH Study estimates of TSNA exposure among US adult users of a variety of tobacco products. These data can inform future tobacco product and human exposure evaluations and related regulatory activities.

scholarly journals Retrospection of Anti–Blood Group Antibody Proficiency Testing Data Using the Geometric Mean and Standard Deviation

2019 ◽  
Vol 153 (4) ◽  
pp. 530-536 ◽  
Author(s):  
John Jeongseok Yang ◽  
Yousun Chung ◽  
Hyungsuk Kim ◽  
Dae-Hyun Ko ◽  
Sang-Hyun Hwang ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Blood Group ◽  
Proficiency Testing ◽  
Geometric Mean ◽  
Geometric Standard Deviation ◽  
Geometric Means ◽  
Consensus Criterion ◽  
Mode 2 ◽  
Testing Data ◽  
The Mean

Abstract Objectives We reanalyzed the data from proficiency testing (PT) to assess the effect of the geometric mean in the statistical analysis of immunohematologic data. Methods Using the five most recent anti–blood group antibody titer participant summary results, the geometric mean (GM) ±2 × geometric standard deviation (GSD) was used as the comparative consensus criterion to mode ±2 titers. Results Using the PT evaluation criterion of mode ±2 titers, the mean percentages of participants with acceptable results were 97.5% and 97.8% for anti-A and anti-D, respectively. When applying GM ±2 GSD, the mean percentages of acceptable results were 96.1% (anti-A) and 96.1% (anti-D). The percentages of responses included in each consensus criterion were lower using GM ±2 GSD, with a few exceptions. Conclusions Geometric means are more robust and precise in visualizing the central tendency. This method can improve the statistical robustness of PT evaluations.

The Use of Judgment Matrices in Subjective Workload Assessment: The Subjective Workload Dominance (SWORD) Technique

1989 ◽  
Vol 33 (20) ◽  
pp. 1406-1410 ◽  
Author(s):  
Michael A. Vidulich
Keyword(s):  
Analytic Hierarchy Process ◽  
Assessment Tool ◽  
Geometric Mean ◽  
Data Sets ◽  
Analytic Hierarchy ◽  
Geometric Means ◽  
Subjective Workload ◽  
Hierarchy Process

One objective of the project was to determine compare two analytic algorithms for converting judgment matrices into subjective workload ratings. The original eigenvector algorithm used in Saaty's Analytic Hierarchy Process (AHP) was compared an algorithm of calculating geometric means. Also, three methods of identifying excessively inconsistent matrices were compared. Data from nine previous experiments were re-examined in the present analysis. There were no differences between the AHP ratings and the geometric mean ratings in terms of their sensitivity to the experimental manipulations. However, two of the inconsistency measures were successfully used to cull the data-sets of inconsistent matrices and improved the statistical sensitivity of one set of ratings. These findings suggest that: (1) the computationally simpler geometric means algorithm can be used as an alternative to the eigenvector algorithm, and (2) culling inconsistent matrices can sometimes improve rating sensitivity. These findings, along with previous research, demonstrate that judgment matrices can be a very valuable workload assessment tool. The essential steps for the proper use of judgment matrices in workload assessment are reviewed. A user's guide and software are also being prepared to aid researchers and practitioners

scholarly journals Proofs of an Inequality

1905 ◽  
Vol 24 ◽  
pp. 45-50 ◽  
Author(s):  
R. F. Muirhead
Keyword(s):  
Finite Number ◽  
Present Article ◽  
General Type ◽  
Geometric Mean ◽  
Arithmetic Mean ◽  
Geometric Means ◽  
The Given

§ 1. The inequality of the Arithmetic and Geometric Means of n positive quantities has been proved by many different methods; of which a classified summary has been given in the Mathematical Gazette (Vol. II., p. 283). The present article may be looked on as supplementary to that summary. It deals with proofs that belong to a general type, of which the proof given in the Tutorial Algebra, §205, and that given by Mr G. E. Crawford in our Proceedings, Vol. XVIII., p. 2, are very special limiting cases. Proofs of the type in question consist of a finite number of steps, by which, starting from the n given quantities, and changing two at a time according to some law, we reach a new set of quantities whose arithmetic mean is not greater, and whose geometric mean is not less than the corresponding means of the given quantities.

The Risk Premium on Ordinary Shares

1995 ◽  
Vol 1 (2) ◽  
pp. 251-330 ◽  
Author(s):  
A.D. Wilkie
Keyword(s):  
Risk Premium ◽  
Geometric Mean ◽  
Arithmetic Mean ◽  
Short Term ◽  
Arithmetic Means ◽  
Price Inflation ◽  
Geometric Means ◽  
True Model ◽  
The Difference

ABSTRACTThe risk premium on ordinary shares is investigated, by studying the total returns on ordinary shares, and on both long-term and short-term fixed-interest investments over the period 1919 to 1994, and by analysing the various components of that return. The total returns on ordinary shares exceeded those on fixed-interest investments by over 5% p.a. on a geometric mean basis and by over 7% p.a. on an arithmetic mean basis, but it is argued that these figures are misleading, because most of the difference can be accounted for by the fact that price inflation turned out to be about 4.5% p.a. over the period, whereas investors had been expecting zero inflation.Quotations from contemporary authors are brought forward to demonstrate what contemporary attitudes were. Simulations are used along with the Wilkie stochastic asset model to show what the results would be if investors make various assumptions about the future, but the true model turns out to be different from what they expected. The differences between geometric means of the data and arithmetic means are shown to correspond to differences between using medians or means of the distribution of future returns, and it is suggested that, for discounting purposes, medians are the better measure.

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