315 results on '"M. Laviolette"'
Search Results
2. Effect of Bronchial Thermoplasty on Alarmin (S100A7/A8/A9) Expression in Severe Asthma
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P Gagnon, S Assou, M Salem, S Biardel, J De Vos, N Lampron, S Martel, L Boulet, M Laviolette, C Laprise, and J Chakir
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- 2022
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3. Instrumentation and monitoring plan for the 2nd Avenue network arch bridge with posttensioned tie girders
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A.R.M.H.B. Amunugama, U.B. Attanayake, H. Aktan, M. LaViolette, and M. Chynoweth
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- 2022
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4. Creep and shrinkage estimation for low-heat concrete mix used in the 2nd Avenue network arch bridge
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K. Basnayake, U.B. Attanayake, M. LaViolette, and M. Chynoweth
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- 2022
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5. Spatial distribution of uranium in mice kidneys detected by laser ablation inductively coupled plasma mass spectrometry
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Corinne M. LaViolette, Margaret M. Briehl, Venessa Jim, and Jani C. Ingram
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inorganic chemicals ,0301 basic medicine ,microprobe ,Laser ablation inductively coupled plasma mass spectrometry ,medicine.medical_treatment ,lcsh:RS1-441 ,chemistry.chemical_element ,Spatial distribution ,mice kidney ,complex mixtures ,Article ,uranium ,lcsh:Pharmacy and materia medica ,lcsh:Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,medicine ,LA-ICP-MS ,Inductively coupled plasma mass spectrometry ,Kidney ,Radiochemistry ,technology, industry, and agriculture ,Uranium ,Ablation ,030104 developmental biology ,medicine.anatomical_structure ,lcsh:QD1-999 ,Uranyl nitrate ,chemistry ,Toxicity - Abstract
The aim of the study is to better understand where uranium deposits in mice kidneys. The spatial distribution of uranium was examined in the kidneys of C57BL/6 mice using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Mice were exposed to varying levels of uranyl nitrate in their drinking water. Calibration standards were developed to allow for semi-quantitative measurement of uranium in the cortical and medullary regions of mice kidney by LA-ICP-MS. Scanning electron microscopy was used to image the ablation patterns on the kidney. Uranium levels were observed to increase in kidney tissue as uranyl nitrate treatment exposure levels increased. A trend towards a higher uranium concentration in the medullary versus cortical region of the kidneys was observed. These results show the usefulness of LA-ICP-MS in toxicity studies by providing a quantitative, spatial assessment of uranium deposition in a target organ.
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- 2017
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6. S132 Ten-year efficacy and safety following bronchial thermoplasty for asthma – the BT10+ study
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Salman Siddiqui, Sumita Khatri, Adalberto Sperb Rubin, Jussara Fiterman, M. Laviolette, Richard G. Barbers, Robert Niven, GM Grubb, Rekha Chaudhuri, J Lapa e Silva, Karin Klooster, Kaharu Sumino, David Duhamel, and Pallav L. Shah
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Spirometry ,medicine.medical_specialty ,Bronchiectasis ,Asthma exacerbations ,Bronchial thermoplasty ,medicine.diagnostic_test ,business.industry ,Inhaled corticosteroids ,medicine.disease ,Safety profile ,Quality of life ,Internal medicine ,medicine ,business ,Asthma - Abstract
Background Bronchial thermoplasty (BT) is a non-pharmacologic, endoscopic treatment for asthma not well controlled with long-acting b-agonists and inhaled corticosteroids. Long-term efficacy and safety of BT beyond 5 years is unknown. The BT10+ study was designed to evaluate the efficacy and safety of BT at 10+ years follow-up. Methods BT10+ is an international, multi-center, ≥10yrs follow-up study on subjects who were enrolled in the AIR, RISA and AIR2 BT trials. Demographics, quality of life, lung function, severe exacerbations (SE, defined as asthma exacerbations requiring systemic corticosteroids) and healthcare utilisation for the previous year were collected at the BT10+ study visit. Additionally, AIR2 subjects who received a pulmonary high-resolution CT (HRCT) at baseline had a second scan at the BT10+ study visit to determine if clinically relevant changes, such as bronchiectasis, occur after BT. Results Of 429 subjects enrolled AIR, RISA, and AIR2, 192 were followed-up at 10.6–15.8 years (12.1 median) post-treatment at 16 centers; of these, 136 were treated with BT and 38 were control/sham subjects in previous studies. Baseline characteristics between subjects enrolled and not enrolled in BT10+ did not show meaningful differences. For BT subjects, no increases in the rate of hospitalisations or ER visits were observed compared to baseline and rates of SE were stable compared to Year 1 (figure 1). While both groups experienced fewer SE after treatment, BT subjects had fewer SE than control/sham subjects at the BT10+ visit; this was not significant. Quality of life (AQLQ, ACQ) and spirometry results were comparable between Years 1, 5, and 10+ for both groups. Pulmonary HRCT scans from AIR2 subjects at the BT10+ study visit showed 9.5% (2/21) of control/sham subjects and 13.4% (13/97) of BT subjects had bronchiectasis; however, when these were compared with baseline HRCT scans, only 5.3% (5/94) of BT subjects had developed bronchiectasis after their baseline visit. Conclusion The BT10+ study suggests that efficacy of BT is sustained over 10 years and that BT has an acceptable safety profile.
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- 2019
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7. Long-Term Efficacy and Safety of Bronchial Thermoplasty (BT): 4 Year Follow-Up Results from a Large Scale Prospective Study
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G.M. Grubb, Charlene McEvoy, Mark T. Dransfield, Andrew R. Haas, Jennifer Toth, E. Lawson, R. Kahlstrom, Kyle B. Enfield, Michael Simoff, Carla Lamb, Ron Olivenstein, Sandeep Bansal, Sumita Khatri, S. Ryan, D.K. Hogarth, JM FitzGerald, Richard Tejedor, Geoffrey Chupp, J.S. Ferguson, M. Laviolette, Momen M. Wahidi, Adrian Shifren, Guido Silvestri, Adnan Majid, Joel N. Kline, Marc McClelland, and Mario Castro
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medicine.medical_specialty ,Bronchial thermoplasty ,Scale (ratio) ,business.industry ,Physical therapy ,Medicine ,Follow up results ,business ,Prospective cohort study ,Term (time) - Published
- 2019
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8. Longitudinal stability of asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study
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M. Laviolette, Pascal Chanez, Pierre-Olivier Girodet, Steven G. Kelsen, Sumita Khatri, JM FitzGerald, Elliot S. Barnathan, Celeste Porsbjerg, Joel N. Kline, Vedrana S. Susulic, Philip E. Silkoff, Vibeke Backer, Dave Singh, Matthew J. Loza, Patrick Berger, and F. Baribaud
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Male ,Severity of Illness Index ,0302 clinical medicine ,Risk Factors ,Bronchodilator ,Prevalence ,030212 general & internal medicine ,medicine.diagnostic_test ,Research Support, Non-U.S. Gov't ,Middle Aged ,respiratory system ,Clinical Trial ,Longitudinal stability ,Bronchodilator Agents ,Respiratory Function Tests ,Europe ,Multicenter Study ,Phenotypes ,Treatment Outcome ,Asthma Control Questionnaire ,Female ,medicine.symptom ,Pulmonary and Respiratory Medicine ,Adult ,Spirometry ,medicine.medical_specialty ,medicine.drug_class ,Sensitivity and Specificity ,Severity ,03 medical and health sciences ,FEV1/FVC ratio ,Internal medicine ,Severity of illness ,Journal Article ,medicine ,Humans ,Asthma ,business.industry ,Research ,Profiling ,Sputum ,Reproducibility of Results ,medicine.disease ,respiratory tract diseases ,030228 respiratory system ,North America ,Exhaled nitric oxide ,Physical therapy ,business ,Biomarkers - Abstract
BACKGROUND: Asthma is a biologically heterogeneous disease and development of novel therapeutics requires understanding of pathophysiologic phenotypes. There is uncertainty regarding the stability of clinical characteristics and biomarkers in asthma over time. This report presents the longitudinal stability over 12 months of clinical characteristics and clinically accessible biomarkers from ADEPT.METHODS: Mild, moderate, and severe asthma subjects were assessed at 5 visits over 12 months. Assessments included patient questionnaires, spirometry, bronchodilator reversibility, fractional exhaled nitric oxide (FENO), and biomarkers measured in induced sputum.RESULTS: Mild (n = 52), moderate (n = 55), and severe (n = 51) asthma cohorts were enrolled from North America and Western Europe. For all clinical characteristics and biomarkers, group mean data showed no significant change from visit to visit. However, individual data showed considerable variability. FEV1/FVC ratio showed excellent reproducibility while pre-bronchodilator FEV1 and FVC were only moderately reproducible. Of note bronchodilator FEV1 reversibility showed low reproducibility, with the nonreversible phenotype much more reproducible than the reversible phenotype. The 7-item asthma control questionnaire (ACQ7) demonstrated moderate reproducibility for the combined asthma cohorts, but the uncontrolled asthma phenotype (ACQ7 > 1.5) was inconstant in mild and moderate asthma but stable in severe asthma. FENO demonstrated good reproducibility, with the FENO-low phenotype (FENO CONCLUSIONS: The ADEPT cohort showed group stability, individual stability in some parameters e.g. low FEV1/FVC ratio, and low FENO, but marked individual variability in other clinical characteristics and biomarkers e.g. type-2 biomarkers over 12 months. This variability is possibly related to seasonal variations in climate and allergen exposure, medication changes and acute exacerbations. The implications for patient selection strategies based on clinical biomarkers may be considerable.
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- 2016
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9. Influence of smoking on airway inflammation and remodelling in asthma
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M. Laviolette, Celine Bergeron, Christian Couture, Nathalie Pagé, St-Laurent J, and L.-P. Boulet
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Bronchus ,education.field_of_study ,biology ,business.industry ,Immunology ,Population ,Respiratory disease ,Tryptase ,medicine.disease ,Neutrophilia ,Tobacco smoke ,respiratory tract diseases ,medicine.anatomical_structure ,Neutrophil elastase ,medicine ,biology.protein ,Immunology and Allergy ,medicine.symptom ,business ,education ,Asthma - Abstract
Summary Background Although exposure to tobacco smoke has been associated with increased morbidity and mortality, cigarette smoking is still common in the asthmatic population. Induced sputum neutrophilia has been observed in asthmatic smokers, but the effects of regular smoking on their bronchial mucosa morphology remain to be defined. This study documents the inflammatory and remodelling features in bronchial biopsies of smoking compared with non-smoking asthmatics. Methods We analysed bronchial biopsies from 24 steroid-naive young subjects with mild asthma: 12 non-smoking and 12 currently smoking subjects. In addition to airway morphology assessment, inflammation and remodelling were analysed by immunohistochemistry using antibodies against CD3, CD68, major basic protein, neutrophil elastase, and tryptase. Expression of the cytokines IL-4, IL-5, IL-8, IFN-γ, transforming growth factor-β, and TNF was determined by in situ hybridization. Results Compared with non-smoking asthmatic subjects, smoking asthmatics' bronchial mucosa showed squamous cell metaplasia, in addition to increased expression of subepithelial neutrophil elastase, IFN-γ, and intraepithelial IL-8. Conclusions Smoking status modifies morphological and inflammatory processes in young subjects with mild asthma. The changes may possibly affect asthma treatment responses and clinical outcomes.
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- 2008
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10. Budesonide/formoterol maintenance and reliever therapy: impact on airway inflammation in asthma
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JM FitzGerald, L-P Boulet, Malcolm R. Sears, J S-M Lee, Tony R. Bai, M. Laviolette, N Smiljanic-Georgijev, and Alan Kaplan
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Adult ,Male ,Pulmonary and Respiratory Medicine ,Budesonide ,medicine.medical_specialty ,Adolescent ,Exacerbation ,medicine.drug_class ,Cost-Benefit Analysis ,Anti-Inflammatory Agents ,Pharmacotherapy ,Formoterol Fumarate ,Internal medicine ,medicine ,Humans ,Child ,Aged ,Asthma ,Aged, 80 and over ,business.industry ,Middle Aged ,medicine.disease ,Bronchodilator Agents ,respiratory tract diseases ,Surgery ,Treatment Outcome ,Budesonide/formoterol ,Ethanolamines ,Corticosteroid ,Drug Therapy, Combination ,Female ,Formoterol ,business ,medicine.drug - Abstract
The aim of the present study was to compare the effectiveness, safety and health economics of budesonide/formoterol maintenance and a novel reliever therapy with conventional best practice in patients with persistent asthma in Canada. After 2 weeks of usual therapy, 1,538 patients were randomised for 6 months to open-label budesonide/formoterol maintenance and reliever therapy 160/4.5 microg twice daily and as needed, or to guideline-based conventional best practice. Severe asthma exacerbations, reliever medication use and total inhaled corticosteroid dose were analysed in all patients and airway inflammation was assessed in a sub-study of 115 patients. No differences were seen in time to first severe exacerbation and severe asthma exacerbation rate. There were numerically fewer emergency room visits or hospitalisations with budesonide/formoterol maintenance and reliever therapy (4.4 versus 7.5 events per 100 patients x yr(-1), 41% reduction); however, this did not reach statistical significance. Mean total inhaled corticosteroid dose, reliever use, asthma medication costs and total annual costs per patient were all significantly lower with budesonide/formoterol maintenance and reliever therapy. Mean sputum eosinophil cell counts remained in the range for controlled inflammation in both groups. In conclusion, budesonide/formoterol maintenance and reliever therapy achieved similar or improved clinical control compared with conventional best practice, with significantly lower total inhaled corticosteroid dose and lower cost, while maintaining similar control of eosinophilic inflammation.
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- 2008
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11. QGE031 (ligelizumab) is more effective than omalizumab and placebo in inhibiting allergen-induced early asthmatic response: Results from a predictive modeling study
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Christopher Carlsten, Ann-Sofie Lantz, Philip J. Lowe, M. Laviolette, J. Mark FitzGerald, Richard Leigh, Joanne Milot, Barbro Dahlén, Miranda Bowen, Donald W. Cockcroft, Karin Meiser, Anton Drollmann, Paul M. O'Byrne, Linda Hui, Veronica A. Swystun, Jonathan P. Arm, Gail M. Gauvreau, Karin Strandberg, Beth E. Davis, Richard M. Watson, Andrej Skerjanec, Louis-Philippe Boulet, Irvin Mayers, S. Maahs, and Kieran J. Killian
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biology ,business.industry ,FCER1 ,Omalizumab ,Basophil ,Immunoglobulin E ,medicine.disease_cause ,Placebo ,medicine.anatomical_structure ,Allergen ,Ligelizumab ,Immunology ,medicine ,biology.protein ,Dosing ,business ,medicine.drug - Abstract
Aim: QGE031 is a high-affinity humanized anti-IgE antibody in development for treatment of uncontrolled severe asthma. We predicted steady-state dose responses by fitting a mathematical model to PKPD data. Methods: Subjects with mild, atopic asthma (N=37) were randomised to 3 s.c. doses (240mg,N=8; 72mg,N=8; 24mg,N=8) of QGE031 every 2 weeks (wks) for 12wks, Omalizumab (OMA) (N=6; US dosing table) or placebo (N=7). Allergen challenges were conducted 6, 12 and 18 wks after the first dose. Mathematical functions were fitted to full time course drug, total IgE and basophil data. After curve fitting, 0-6 month responses of ∼1000 patients, each receiving an array of 4 wkly administrations of QGE031 (0-1200mg) and OMA (US dosing table), were simulated. Results: The model fitted the response data, down regulation of basophil FceR1 and surface IgE, and inhibition of bronchial and skin allergen reactivity from subjects treated with QGE031 and OMA. QGE031 36mg, dosed every 4 wks, was predicted to give similar skin wheal and allergen PC15 responses to OMA. Higher doses of QGE031 would be required for patients with higher baseline IgE. Conclusion: QGE031 is more effective than OMA in inhibiting bronchial and skin allergen response in a clinical setting. This mathematical model could allow better planning and prediction of future trial outcomes.
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- 2015
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12. Effects of Inlet Air Distortion on Gas Turbine Combustion Chamber Exit Temperature Profiles
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R. Woodason, O. Maqsood, and M. LaViolette
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geography ,geography.geographical_feature_category ,Materials science ,Meteorology ,Internal combustion engine ,Sauter mean diameter ,Nozzle ,Airflow ,Back-fire ,Mechanics ,Combustion chamber ,Inlet ,Combustion - Abstract
Localized damage to turbine inlet nozzles is typically caused by non-uniform temperature distributions at the combustion chamber exit. This damage results in decreased turbine performance and can lead to expensive repair or replacement. A test rig was designed and constructed for the Rolls-Royce Allison 250-C20B dual-entry combustion chamber to investigate the effects of inlet air distortion on the combustion chamber’s exit temperature fields. The rig includes a purposely built water cooled thermocouple rake to sweep the exit plane of the combustion chamber. Test rig operating conditions simulated normal engine cruise conditions by matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either combustion chamber inlet. An even distribution of inlet air to the combustion chamber did not produce a uniform temperature profile and varying the inlet distribution of air exacerbated the profile’s non-uniformity. The design of the combustion chamber promoted the formation of an oval-shaped toroidal vortex inside the combustion liner, causing localized hot and cool sections separated by 90° that were apparent in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most airflow and decreasing the temperature of the hot section on the opposite side.
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- 2015
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13. Additional file 2: of Asthma characteristics and biomarkers from the Airways Disease Endotyping for Personalized Therapeutics (ADEPT) longitudinal profiling study
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P. Silkoff, I. Strambu, M. Laviolette, D. Singh, J. FitzGerald, S. Lam, S. Kelsen, A. Eich, A. Ludwig-Sengpiel, G. Hupp, V. Backer, C. Porsbjerg, P. Girodet, P. Berger, R. Leigh, J. Kline, M. Dransfield, W. Calhoun, A. Hussaini, S. Khatri, P. Chanez, V. Susulic, E. Barnathan, M. Curran, A. Das, C. Brodmerkel, F. Baribaud, and M. Loza
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immune system diseases ,respiratory tract diseases - Abstract
Asthma History Questionnaire. (DOCX 29 kb)
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- 2015
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14. Determining asthma treatment by monitoring sputum cell counts: effect on exacerbations
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L Jayaram, Emilio Pizzichini, Richard J. Cook, André Cartier, Marcia Margaret Menezes Pizzichini, Krishnan Parameswaran, Frederick E. Hargreave, Catherine Lemière, M. Laviolette, L.-P. Boulet, P. Hussack, and Charles H. Goldsmith
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Adult ,Male ,Pulmonary and Respiratory Medicine ,Spirometry ,Relative risk reduction ,medicine.medical_specialty ,Exacerbation ,Cell Count ,Prednisone ,Internal medicine ,medicine ,Humans ,Fluticasone ,Asthma ,medicine.diagnostic_test ,business.industry ,Cumulative dose ,Sputum ,Middle Aged ,medicine.disease ,Surgery ,Female ,medicine.symptom ,business ,medicine.drug - Abstract
One important goal of asthma treatment is to reduce exacerbations. The current authors investigated if the use of sputum cell counts to guide treatment would achieve this goal. A total of 117 adults with asthma were entered into a multicentre, randomised, parallel group-effectiveness study for two treatment strategies over a 2-yr period. In one strategy (the clinical strategy: CS) treatment was based on symptoms and spirometry. In the other (the sputum strategy: SS) sputum cell counts were used to guide corticosteroid therapy to keep eosinophilsor=2%; symptoms and spirometry were used to identify clinical control, exacerbations and other treatments. Patients were blind to sputum cell counts in both strategies and physicians were blind in the CS, thus removing bias. First, the minimum treatment to maintain control was identified in 107 patients (Phase 1) and then this treatment was continued (Phase 2) for the remaining of the 2 yrs. The primary outcomes were the relative risk reduction for the occurrence of the first exacerbation in Phase 2 and the length of time without exacerbation. The current authors also examined the type and severity of exacerbations and the cumulative dose of inhaled steroid needed. The duration and number of exacerbations in Phase 1 were similar in both groups. In Phase 2 there were a 126 exacerbations of which 79 occurred in the CS (62.7%) and 47 (37.3%) in the SS groups. The majority of the 126 exacerbations (101; 80.1%) were mild. The majority of the 102 exacerbations, where sputum examination was performed before any treatment (n=70), were noneosinophilic. In the SS patients, the time to the first exacerbation was longer (by 213 days) especially in those considered to need treatment with a long acting beta2-agonist (by 490 days), the relative risk ratio was lower (by 49%), and the number of exacerbations needing prednisone was reduced (5 versus 15). This benefit was seen mainly in patients needing treatment with inhaled steroid in a daily dose equivalent to fluticasone250 microg, and was due to fewer eosinophilic exacerbations. The cumulative dose of corticosteroid during the trial was similar in both groups. Monitoring sputum cell counts was found to benefit patients with moderate-to-severe asthma by reducing the number of eosinophilic exacerbations and by reducing the severity of both eosinophilic and noneosinophilic exacerbations without increasing the total corticosteroid dose. It had no influence on the frequency of noneosinophilic exacerbations, which were the most common exacerbations.
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- 2006
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15. Variability of Inflammatory Cell Counts on Bronchial Biopsies of Normal Subjects
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Hélène Turcotte, M. Laviolette, L.-P. Boulet, and M. Boutet
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Adult ,Male ,Pulmonary and Respiratory Medicine ,Pathology ,medicine.medical_specialty ,Pathophysiology of asthma ,Adolescent ,Biopsy ,Connective tissue ,Bronchi ,Cell Count ,Bronchial Provocation Tests ,Immune system ,Predictive Value of Tests ,Reference Values ,Bronchoscopy ,medicine ,Animals ,Humans ,IL-2 receptor ,Skin Tests ,Observer Variation ,business.industry ,Smoking ,Epithelial Cells ,Middle Aged ,Immunohistochemistry ,Asthma ,Pathophysiology ,Respiratory Function Tests ,medicine.anatomical_structure ,Female ,Airway ,business ,CD8 - Abstract
Bronchial biopsies are currently used to study the pathophysiology of airway diseases, and comparisons are often made with biopsies from healthy volunteers. It is therefore important to evaluate the variability in each parameter analyzed in bronchial biopsies of healthy volunteers in order to be able to discriminate significant changes. We analyzed bronchial biopsies of 31 nonsmoking, nonatopic healthy subjects who volunteered as normal controls for studies on pathophysiology of asthma. Mean % epithelial desquamation was 23.7% of observed total epithelial length. No subepithelial fibrosis was observed. Inflammatory cell counts (/mm(2) connective tissue surface) were variable among subjects but not different between small (or=0.25 mm(2)) and large biopsies. Medians (range) of positive cells were for CD3: 20.5 (0-530.0), CD4: 6.2 (0-124.4), CD8: 1.8 (0-81.5), CD25: 0 (0-62.3), HLA-DR: 80.0 (3.5-524.2), EG1: 5.3 (0-180.6), EG2: 6.4 (0-48.8), AA1: 51.3 (0-286.4), CD45: 39.7 (0-448.5) and CD45ro: 28.6 (0-425.2). Subjects living in an urban area had significantly higher CD8-positive cell counts than those from suburban areas ( p = 0.0001). The presence of an animal at home was associated with lower positive cell counts for CD4 ( p = 0.02), CD45 ( p = 0.02) and HLA-DR ( p = 0.01). In conclusion, the variability in the number and expression of markers of activity of bronchial immune cells in normal subjects likely reflects variable host responses to environmental exposures and must be taken into account when compared to specimens obtained in subjects with airway diseases.
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- 2003
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16. Migration through basement membrane modulates eosinophil expression of CD44
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M.‐J. Dallaire, M. Laviolette, Sophie Lavigne, Jamila Chakir, and Claudine Ferland
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Basement membrane ,Matrigel ,biology ,medicine.medical_treatment ,Immunology ,CD44 ,Eosinophil ,Molecular biology ,medicine.anatomical_structure ,Eosinophil migration ,Cytokine ,Cell surface receptor ,medicine ,biology.protein ,Immunology and Allergy ,Eosinophil peroxidase - Abstract
BACKGROUND Tissue eosinophils express more membrane receptors and release more mediators than blood eosinophils, suggesting that migration from blood to tissue modulates eosinophil phenotype and functions. OBJECTIVE We postulated that eosinophil passage through endothelial basement membrane, an important step of eosinophil migration into tissue, may be responsible for some of these changes. METHOD We previously showed that 5-oxo-6, 8, 11, 14-eicosatetraenoic acid (5-oxo-ETE) in combination with IL-5 promotes eosinophil migration through Matrigel, a mouse tumour cell-derived basement membrane. Using this model, we evaluated the effect of trans-Matrigel migration on purified human blood eosinophil expressions of CD44, CD69 and HLA-DR that either increase or appear on activated eosinophils, and releases of peroxidase (EPO), leukotriene (LT) C(4) and granulocyte-monocyte colony stimulating factor (GM-CSF). RESULTS IL-5, but not 5-oxo-ETE, increased eosinophil expression of CD44 and CD69. Migration of eosinophils through Matrigel significantly increased CD44 expression level over the one induced by IL-5 (P = 0.0001). Migration through Matrigel did not modify CD69 expression compared with the one obtained in the presence of IL-5 alone; however, incubation of eosinophils on Matrigel decreased IL-5-induced CD69 (P = 0.0001). Trans-Matrigel migration did not modify HLA-DR expression, nor EPO, LTC(4) and GM-CSF releases. CONCLUSION These data show that in vitro trans-Matrigel migration and Matrigel contact modulate eosinophil membrane receptor expression. Consequently, they suggest that migration through basement membrane mediates changes in cell-surface phenotype observed on activated eosinophils and probably prepares them for interactions with tissue components and cells.
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- 2002
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17. [Bronchial thermoplasty in the treatment of severe adult asthma]
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P, Chanez, L-P, Boulet, P-Y, Brillet, G, Joos, M, Laviolette, R, Louis, T, Rochat, P, Soccal, and M, Aubier
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Adult ,Young Adult ,Postoperative Complications ,Adolescent ,Bronchoscopy ,Catheter Ablation ,Electrocoagulation ,Humans ,Bronchi ,Middle Aged ,Severity of Illness Index ,Asthma ,Aged - Abstract
Bronchial thermoplasty is a recent endoscopic technique for the treatment of severe asthma. It is an innovative treatment whose clinical efficacy and safety are beginning to be better understood. Since this is a device-based treatment, the evaluation procedure of risks and benefits is different that for pharmaceutical products; safety aspects, regulatory requirements, study design and the assessment of the magnitude of effects may all be different. The mechanism of action and optimal patient selection need to be assessed further in rigorous clinical and scientific studies. This technique is in harmony with the development of personalised medicine in the 21st century. It should be developed further in response to the numerous challenges and needs not yet met in the management of severe asthma.
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- 2014
18. Effect of salmeterol on allergen-induced airway inflammation in mild allergic asthma
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M. Boutet, Julie Milot, Jamila Chakir, L.-P. Boulet, and M. Laviolette
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Allergy ,Inhalation ,medicine.diagnostic_test ,business.industry ,medicine.drug_class ,Immunology ,Provocation test ,Context (language use) ,respiratory system ,medicine.disease ,respiratory tract diseases ,Bronchoalveolar lavage ,Bronchodilator ,Immunology and Allergy ,Medicine ,Methacholine ,Salmeterol ,business ,medicine.drug - Abstract
A previous study suggested that the long-acting β2-adrenergic agonist salmeterol (SM) had inhibitory effects on bronchial mucosal inflammation 6 hours after allergen exposure. To further evaluate the influence of SM on allergen-induced airway inflammation. We studied, in a randomized, double-blind, cross-over trial, 16 mild asthmatic patients who had a dual asthmatic response to allergen inhalation. Subjects received 50 µg of SM or placebo (P), twice daily for 1 week each, separated by a 2-week wash-out period. At the end of each treatment period, after withholding SM for 24 h, they had a methacholine inhalation test (medication was resumed after the test), followed 24 h later by an AC with the concentration of allergen that had induced a LAR at baseline. Airway inflammation was assessed 24 h after the AC by bronchoalveolar lavage (BAL) (n = 16) and bronchial biopsies (n = 13). As expected, SM improved baseline FEV1 and PC20 (P ≤ 0.009) and decreased the allergen-induced early bronchoconstrictive response. There were no significant differences in BAL cell counts after the two treatments. On bronchial biopsies, numbers (median, mm2) of submucosal CD45 (P: 43 ± 23; SM: 161 ± 43, P = 0.031), CD45Ro (P: 37 ± 19; SM: 126 ± 41, P = 0.047) and AA1 positive cells (P: 38 ± 6, SM: 65 ± 17, P = 0.006) were significantly higher after SM than P treatment. The numbers of CD4 (P: 11 ± 10; SM: 32 ± 7, P = 0.085), HLA-DR (P: 65 ± 30; SM: 116 ± 36, P = 0.079) and EG2 positive cells (P: 25 ± 15; SM: 38 ± 26, P = 0.09) tended to increase with SM treatment. In summary, compared to placebo, 1 week of regular use of SM is associated with an increase in bronchial inflammatory cells 24 h after AC. This is in keeping with the recommendation that salmeterol should only be used with an anti-inflammatory agent, particularly in the context of significant allergen exposure.
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- 2001
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19. Skin bruising, adrenal function and markers of bone metabolism in asthmatics using inhaled beclomethasone and fluticasone
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JL Malo, A Cartier, H Ghezzo, S Mark, J Brown, M Laviolette, and LP Boulet
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Pulmonary and Respiratory Medicine - Abstract
Fluticasone propionate (FP) is generally considered to have twice the efficacy of beclomethasone dipropionate (BDP) on a weight-to-weight basis for the control of asthma, and may have lesser effects on adrenal function. However, the effects of FP and BDP on skin integrity and bone metabolism markers require further examination. Sixty-nine asthmatic subjects were enrolled in a double-blind crossover study in which, after a baseline period, they received BDP or FP (at half the dose of BDP) for two 4-month periods each. A questionnaire on skin bruising, a skin examination, tests of adrenal function and of markers of bone metabolism were performed after 2 months of each period. The number of asthma exacerbations was not significantly different for the two treatment periods (eight for BDP and nine for FP), nor were various indices of asthma control. Whereas the frequency of bruising reported by the questionnaire was not different, there were more bruises on examination for BDP (1.6+/-2.5) than for FP (1.2+/-2.3) (p=0.04). Although baseline serum cortisol was not significantly different for the two drugs, the increase in cortisol after cortrosyn was lower for BDP (357+/-158 micromol x dL(-1)) than for FP (422+/-144 micromol x dL(-1)) (p
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- 1999
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20. Tolerance to the protective effects of salmeterol on methacholine-induced bronchoconstriction: influence of inhaled corticosteroids
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J.-L. Malo, Joanne Milot, Johanne Côté, M. Laviolette, L.-P. Boulet, and André Cartier
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Adult ,Male ,Pulmonary and Respiratory Medicine ,Adolescent ,medicine.drug_class ,Peak Expiratory Flow Rate ,Bronchoconstrictor Agents ,Double-Blind Method ,Adrenal Cortex Hormones ,Forced Expiratory Volume ,Bronchodilator ,Administration, Inhalation ,Humans ,Medicine ,Albuterol ,Salmeterol Xinafoate ,Methacholine Chloride ,Asthma ,Cross-Over Studies ,Inhalation ,business.industry ,Drug Tolerance ,Adrenergic beta-Agonists ,Middle Aged ,medicine.disease ,Crossover study ,respiratory tract diseases ,Anesthesia ,Corticosteroid ,Female ,Bronchoconstriction ,Methacholine ,Salmeterol ,medicine.symptom ,business ,medicine.drug - Abstract
Long-acting beta2-adrenoceptor agonists such as salmeterol reduce airway responsiveness for at least 12 h, but this effect seems to decrease with regular use. We evaluated the time-course of the protective effects of salmeterol on methacholine-induced bronchoconstriction, its modulation by inhaled corticosteroids (ICS) and its influence on asthma control. Thirty two subjects (13 males and 19 females) with mild to moderate stable asthma were divided into two groups according to their medication needs: bronchodilators (BD) alone (n=16) or with ICS (n=16). After a 2 week run-in period, a double-blind crossover study was conducted. Subjects from both groups received salmeterol 50 microg b.i.d. or a placebo for 4 weeks each in random order, separated by a 2 week washout period. The provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (PC20) was measured before and after each treatment period, 1 h prior to inhalation of salmeterol or placebo and 1 and 12 h after. Baseline forced expiratory volume in one second (FEV1) increased significantly after salmeterol, both after the first dose and at 4 weeks (BD group: 19 and 17%; ICS: 22 and 13%). On the first day of administration, salmeterol provided significant protection in both groups up to 12 h with a PC20 before and 1 and 12 h postdose of 2.2, 21.7 and 12.4, mg x mL(-1), respectively, in the BD group and 2.1, 11.6 and 55 mg x mL(-1), respectively, in the ICS group. After 4 weeks, this effect was significantly attenuated in both groups with a PC20 before, 1 and 12 h postdose of 3.3, 10.9 and 7.1 mg x mL(-1), respectively, in the BD group and 2.1, 5.0 and 2.3 mg x mL(-1), respectively, in the ICS group. This loss of protective effect was of similar magnitude in both groups. Respiratory symptoms, rescue beta2-agonist use and baseline FEV1 did not change significantly throughout the study in both groups. In conclusion, the bronchoprotective effect of salmeterol decreased with regular use both 1 and 12 h postdose; inhaled corticosteroids did not prevent this reduction. However, the development of tolerance was not associated with loss of asthma control.
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- 1998
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21. Identification and analysis of eosinophils by flow cytometry using the depolarized side scatter-saponin method
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M. Laviolette, Sophie Lavigne, M. Bossé, and Louis-Philippe Boulet
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medicine.diagnostic_test ,Differential staining ,Biophysics ,Cell Biology ,Hematology ,Granulocyte ,Molecular biology ,Pathology and Forensic Medicine ,Flow cytometry ,chemistry.chemical_compound ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Antigen ,Immunology ,medicine ,Centrifugation ,Paraformaldehyde ,Cytometry ,Percoll - Abstract
This study describes a method for flow cytometric (FCM) identification and analysis of eosinophils (EOS) in mixed granulocyte populations without the need of further cell purification. Granulocytes were prepared from 10 ml blood samples obtained from 14 non-atopic healthy subjects and 16 hypereosinophilic subjects. The cells were fixed in paraformaldehyde (PFA) and permeabilized with either saponin or n-octyl-beta-D-glucopyranoside (OG) before FCM. Side scatter light (SS) and depolarized sideward light scatterings (dSS) were measured before and after granulocyte fixation and permeabilization. Based on autofluorescence of cells, EOS were depicted in forward scatter (FS)-SS and FS-dSS cytograms. FS-dSS analysis of PFA-saponin-treated cells provided the best discrimination between EOS (high dSS) and neutrophils (low dSS) in normal and hypereosinophilic blood samples (n = 22). Subsequent sorting and differential staining of the two populations further confirmed cell identity in high dSS (97.2 ± 3.0% EOS) and low dSS (99.6 ± 0.5% neutrophils) PFA-saponin-treated cells (n = 5). Similar FS-dSS profiles were obtained for hypodense (HBSS-1.082 g/ml interface) and normodense (1.082–1.100 g/ml interface) EOS separated by centrifugation on discontinuous Percoll gradients and treated with PFA-saponin. Using this method, we successfully detected the cytokines interleukin-2 (IL-2), IL-4, IL-5, and interferon γ (IFNγ) in blood EOS of normal and hypereosinophilic subjects (n = 12). In conclusion, this method allows the analysis of EOS intracellular antigens in mixed granulocyte populations obtained from small blood samples. This analysis is not affected by the buoyant density of eosinophils, and can therefore be applied for the analysis of blood EOS in various types and severities of diseases. Cytometry 29:197–203, 1997. © 1997 Wiley-Liss, Inc.
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- 1997
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22. OX40L blockade and allergen-induced airway responses in subjects with mild asthma
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John G. Matthews, Dana McClintock, Irvin Mayers, Beth E. Davis, M. Laviolette, Wendy S. Putnam, C. Kipling, Christopher Carlsten, Yanan Zheng, Heleen Scheerens, J. M. FitzGerald, Benny Dua, Paul M. O'Byrne, Gail M. Gauvreau, Kieran J. Killian, Mark Larché, Sofia Mosesova, Donald W. Cockcroft, and L.-P. Boulet
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Adult ,Male ,Time Factors ,T-Lymphocytes ,Immunology ,CD40 Ligand ,Immunoglobulin E ,medicine.disease_cause ,Anti-asthmatic Agent ,Leukocyte Count ,Young Adult ,Allergen ,Forced Expiratory Volume ,Immunology and Allergy ,Medicine ,Humans ,Anti-Asthmatic Agents ,CD40 Antigens ,Asthma ,CD40 ,biology ,business.industry ,Effector ,Antibodies, Monoclonal ,Dendritic Cells ,Allergens ,Middle Aged ,medicine.disease ,Blockade ,Eosinophils ,Treatment Outcome ,biology.protein ,Female ,Airway ,business ,Signal Transduction - Abstract
The OX40/OX40L interaction contributes to an optimal T cell response following allergic stimuli and plays an important role in the maintenance and reactivation of memory T effector cells.We tested whether treatment with an anti-OX40L monoclonal antibody (MAb) would inhibit allergen-induced responses in subjects with asthma.Twenty-eight mild, atopic asthmatic subjects were recruited for a double-blind, randomized, placebo-controlled, parallel-group trial (ClinicalTrials.gov identifier NCT00983658) to compare blockade of OX40L using a humanized anti-OX40L MAb to placebo-administered intravenously in 4 doses over 3 months. Allergen inhalation challenges were carried out 56 and 113 days after the first dose of study drug. The primary outcome variable was the late-phase asthmatic response. Other outcomes included the early-phase asthmatic response, airway hyperresponsiveness, serum IgE levels, blood and sputum eosinophils, safety and tolerability.Treatment with anti-OX40L MAb did not attenuate the early- or late-phase asthmatic responses at days 56 or 113 compared with placebo. In the anti-OX40L MAb treatment group, total IgE was reduced 17% from pre-dosing levels, and sputum eosinophils decreased 75% by day 113 (both P = 0.04). There was no effect of anti-OX40L MAb on airway hyperresponsiveness or blood eosinophils. The frequency of AEs was similar in both groups.Pharmacological activity of anti-OX40L MAb was observed by decreases in serum total IgE and airway eosinophils at 16 weeks post-dosing, but there was no effect on allergen-induced airway responses. It is possible that the treatment duration or dose of antibody was insufficient to impact the airway responses.
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- 2013
23. Immunohistochemical detection of GM-CSF, IL-4 and IL-5 in a murine model of allergic bronchopulmonary aspergillosis
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J. M. Wang, M. Boutet, H. W. Chu, L.-P. Boulet, and M. Laviolette
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Pathology ,medicine.medical_specialty ,CD3 Complex ,T-Lymphocytes ,Lymphocyte ,Immunology ,Lymphocytosis ,Immunoglobulin E ,Aspergillosis ,Mice ,medicine ,Animals ,Immunology and Allergy ,Pulmonary Eosinophilia ,Lung ,Interleukin 5 ,Interleukin 4 ,biology ,business.industry ,Aspergillosis, Allergic Bronchopulmonary ,Granulocyte-Macrophage Colony-Stimulating Factor ,Eosinophil ,medicine.disease ,Immunohistochemistry ,Mice, Inbred C57BL ,Disease Models, Animal ,medicine.anatomical_structure ,Granulocyte macrophage colony-stimulating factor ,biology.protein ,Female ,Interleukin-4 ,Interleukin-5 ,Allergic bronchopulmonary aspergillosis ,business ,medicine.drug - Abstract
BACKGROUND Granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin-4 (IL-4) and IL-5 are important in tissue eosinophil accumulation and high IgE production in allergic inflammatory reaction. OBJECTIVE We examine lung GM-CSF, IL-4 and IL-5 expression in a murine model of allergic bronchopulmonary aspergillosis (ABPA) characterized by eosinophil and lymphocyte lung infiltration and elevated serum IgE level. METHODS C57BL/6 mice were intranasally treated three times a week for 1, 2 or 3 week(s) with Aspergillus fumigatus (Af) antigen or saline and were sacrificed on days 7, 14 and 21. Immunohistochemical analyses for GM-CSF, IL-4 and IL-5 were performed on lung sections. RESULTS Af treatment induced a remarkable pulmonary eosinophil influx. Increased numbers of lung T lymphocytes and GM-CSF positive cells were observed on days 14 and 21. IL-4 and IL-5 positive cells were increased significantly only on day 14. Immunostained serial sections showed that most (> or = 98%) cytokine positive cells were CD3 positive. Few eosinophils (< 2% of cytokine positive cells) were immunoreactive for GM-CSF and IL-5. Significant correlations were found between the number of GM-CSF and IL-5 positive cells, and the number of eosinophils in Af-treated lung (r = 0.62, P < 0.05 and r = 0.52, P < 0.05 respectively), and between the number of IL-4 positive cells and the serum total IgE level (r = 0.64, P < 0.01). CONCLUSIONS Our data suggest a role for T lymphocyte GM-CSF, IL-4 and IL-5 in Af-induced mouse pulmonary eosinophilia and increased serum IgE production and further support the importance of T helper (TH2) cells in the pathogenesis of ABPA.
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- 1996
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24. Blood eosinophil leukotriene C4 production in asthma of different severities
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M Laviolette, C Ferland, JF Comtois, K Champagne, M Bosse, and LP Boulet
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Pulmonary and Respiratory Medicine - Abstract
In asthma, activation and recruitment of eosinophils to the bronchial mucosa amplifies many cellular functions. The blood eosinophil count and the number of hypodense eosinophils increase with asthma severity. Eosinophils produce numerous proinflammatory mediators in response to a variety of agonists, notably the peptido-leukotriene (LT) C4, a potent bronchoconstrictor. In this study, we have evaluated blood eosinophil LTC4 release and its modulation by cytokines in normal individuals and in subjects with asthma of various severities: mild (beta 2-agonist on demand); moderate (inhaled steroids on a regular basis); and severe (inhaled and oral steroids on a regular basis). Eosinophils were isolated using a modified Percoll gradient technique, which recovers both hypodense and normodense eosinophils in a global cell population. Eosinophils released detectable amounts of LTC4 only in the presence of the stimulus (calcium ionophore A23187, 2 microM). The ionophore-induced LTC4 release was greater in moderate asthmatics (mean +/- SEM 5.7 +/- 1.3 pg x 10(3)/250,000 eosinophils) than in normal individuals (1.6 +/- 0.4 pg x 10(3)/250,000 eosinophils), mild asthmatics (1.8 +/- 0.3 pg x 10(3)/250,000 eosinophils) and severe asthmatics (2.0 +/- 0.3 pg x 10(3)/250,000 eosinophils). Granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-5 (IL-5) amplified the ionophore-induced LTC4 release in the four groups from 1.9 to 2.6 and 1.9 to 2.8 fold, respectively. Interleukin-3 (IL-3) did not increase LTC4 production except by the eosinophils of the severe asthmatics whose ionophore-induced LTC4 production was enhanced by 1.9 fold. These data demonstrate that the asthmatic bronchial inflammatory process may modify blood eosinophil LTC4 release and its modulation by cytokines according to asthma severity and treatment.
- Published
- 1995
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25. Increased maximal airway response to methacholine during seasonal allergic rhinitis in nonasthmatic subjects: relationships with airway wall thickness and inflammation
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LP Boulet, H Turcotte, G Carrier, M Boutet, and M Laviolette
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Pulmonary and Respiratory Medicine - Abstract
This study was carried out to determine whether the increase in airway responsiveness induced by natural antigenic exposure in nonasthmatic subjects is associated with an increase in maximal bronchoconstrictor response (MBR), and if these changes could be due to an increase in airway wall thickness from allergen-induced increase in airway inflammation. In 11 nonasthmatic subjects with seasonal allergic rhinitis, a methacholine challenge was obtained monthly, during and out of pollen exposure. Each subject had a high-resolution chest tomography in and out of the pollen season, to determine the relative thickness of the right intermediary bronchus over its total diameter (T/D), as well as inflammatory cell counts, apparent basement membrane thickness as an indication of subepithelial fibrosis and epithelial desquamation in bronchial biopsy specimens. In season, the mean provocative concentration of methacholine producing a 20% decrease in forced expiratory volume in one second (PC20) decreased from 51.5 to 25.8 mg.mL-1, and the maximal post-methacholine fall in forced expiratory volume in one second (delta FEV1,max) or forced vital capacity (delta FVC) and the slope of the dose response curve (DRS) increased compared with out of season: delta FEV1,max 44 +/- 5 vs 25 +/- 5%; delta FVC 34 +/- 5 vs 16 +/- 4%; and slope of DRS 14.1 +/- 2.8 vs 6.9 +/- 1.3%/mg.mL-1. No significant change was observed in T/D ratio. The seasonal change in delta FVC was positively correlated with the delta FEV1,max (rs = 0.891) and the change in DRS (rs = 0.909), but not with the change in PC20, nor with changes in bronchial biopsy inflammatory features or T/D ratio.(ABSTRACT TRUNCATED AT 250 WORDS)
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- 1995
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26. Airway inflammation after removal from the causal agent in occupational asthma due to high and low molecular weight agents
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C Leblanc, L.-P. Boulet, M Dugas, M. Laviolette, Johanne Côté, Joanne Milot, L Paquette, M. Boutet, J.-L. Malo, and André Cartier
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Adult ,Male ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Biopsy ,Provocation test ,Bronchi ,Cell Count ,Air Pollutants, Occupational ,Gastroenterology ,Bronchial Provocation Tests ,Occupational Exposure ,Internal medicine ,Bronchoscopy ,medicine ,Humans ,Asthma ,Bronchus ,Inhalation ,medicine.diagnostic_test ,business.industry ,food and beverages ,Smooth muscle hyperplasia ,medicine.disease ,respiratory tract diseases ,Molecular Weight ,Occupational Diseases ,Bronchoalveolar lavage ,medicine.anatomical_structure ,Spirometry ,Immunology ,Female ,Methacholine ,business ,Bronchoalveolar Lavage Fluid ,Occupational asthma ,medicine.drug - Abstract
In order to determine 1) the features of airway inflammation after removal from exposure to high (HMW) and low (LMW) molecular weight agents 2) if there are any differences in the pattern of inflammation induced by these two types of agents, we studied 18 subjects with a recently confirmed diagnosis of occupational asthma (OA) due to HMW (n = 11) and LMW (n = 7) agents. The duration of asthma symptoms varied from 2 to 108 months (mean 33 months), and withdrawal from exposure to the sensitizing agent from 3 to 24 weeks (mean 10 weeks). All subjects underwent measurements of expiratory flow rates, methacholine inhalation tests, and a flexible bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsies. Endoscopic findings were compared with a group of 10 normal subjects. At the time of the bronchoscopy, asthma symptoms were minimal in most subjects. Although 15/18 subjects had normal forced expiratory volume in one second (FEV1 > 80% pred), all subjects had increased airway responsiveness to methacholine (provocation concentration producing a 20% fall in FEV1 = 0.2-10.0 mg.ml-1). BAL analysis showed similar median percentages of the total number of cells and differentials in control subjects and those exposed to HMW and LMW agents. Bronchial biopsies showed that mean inflammatory cell count, both epithelial and sub-epithelial, was similarly raised in OA subjects exposed to either HMW or LMW agents, compared to controls, except for epithelial lymphocyte count. In contrast to the controls, bronchial biopsy of both groups with OA also showed other changes such as extensive epithelial desquamation, ciliary abnormalities of the epithelial cells, smooth muscle hyperplasia and subepithelial fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1994
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27. Unity and diversity of fuzziness-from a probability viewpoint
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J.W. Seaman and M. Laviolette
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Discrete mathematics ,Applied Mathematics ,Fuzzy set ,Probability and statistics ,Fuzzy control system ,Type-2 fuzzy sets and systems ,Fuzzy logic ,Computational Theory and Mathematics ,Artificial Intelligence ,Control and Systems Engineering ,Measurement uncertainty ,Representation (mathematics) ,Mathematical economics ,Mathematics ,Possibility theory - Abstract
Like the fields of probability and statistics, fuzzy set theory is characterized by a variety of viewpoints. Adherents of fuzzy methods, however, consistently maintain that probability is not necessarily the optimal representation of uncertainty. We rebut this view. >
- Published
- 1994
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28. The efficacy of fuzzy representations of uncertainty
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J.W. Seaman and M. Laviolette
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Fuzzy measure theory ,business.industry ,Applied Mathematics ,Uncertainty theory ,Type-2 fuzzy sets and systems ,Computational Theory and Mathematics ,Artificial Intelligence ,Control and Systems Engineering ,Fuzzy number ,Fuzzy set operations ,Sensitivity analysis ,Artificial intelligence ,business ,Uncertainty analysis ,Possibility theory ,Mathematics - Abstract
Advocates of the theory of fuzzy sets as a system for representing uncertainty have based their case on five basic arguments. These are: 1) the reality hypothesis, which holds that imprecision is an inherent property of the world external to an observer; 2) the subjectivity hypothesis, which holds that probability is an exclusively objective measure of uncertainty, and that therefore subjective uncertainty can only be represented with fuzzy sets; 3) the behaviorist hypothesis, which claims that uncertainty systems should emulate rather than prescribe human behavior in the face of uncertainty; 4) the "probability as fiction" hypothesis, which claims that probability does not comprise a field of study in its own right; and 5) the superset hypothesis, which holds that fuzzy set theory includes probability as a special case and thus provides a richer uncertainty modeling environment. We discuss and criticize all five. We then criticize the argument that fuzziness represents a type of uncertainty distinct from probability, and also the inordinate complexity of fuzzy methods. We present a method for assessing the efficacy of fuzzy representations of uncertainty and apply this method in three examples. >
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- 1994
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29. Isolation and characterization of human airway fibroblasts in culture
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J, Chakir, J, Dubé, M, Laviolette, F, Goulet, L, Germain, F, Auger, and L P, Boulet
- Abstract
Asthma is considered an airway inflammatory disorder characterized by variable airflow obstruction and airway hyperresponsiveness (1). The inflammatory component of asthma has been studied extensively over the past few years, but, more recently, the potential contribution of airway wall remodeling to functional and clinical changes has been emphasized (2,3). Although the methods of sampling of bronchial tissue were previously limited, being obtained mostly from autopsic or surgical specimens, they have improved recently.
- Published
- 2011
30. Regulation of epithelial cell proliferation by bronchial fibroblasts obtained from mild asthmatic subjects
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A, Semlali, E, Jacques, M, Rouabhia, J, Milot, M, Laviolette, and J, Chakir
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Tissue Engineering ,Reverse Transcriptase Polymerase Chain Reaction ,Blotting, Western ,Bronchi ,Enzyme-Linked Immunosorbent Assay ,Epithelial Cells ,Cell Communication ,Respiratory Mucosa ,Fibroblasts ,Asthma ,Coculture Techniques ,ErbB Receptors ,Transforming Growth Factor beta ,Microscopy, Electron, Scanning ,Humans ,Cells, Cultured ,Cell Proliferation ,Cyclin-Dependent Kinase Inhibitor Proteins ,Signal Transduction - Abstract
Bronchial epithelium is considered a key player in coordinating airway wall remodelling. The function of epithelial cells can be modulated by the underlying fibroblasts through autocrine and paracrine mechanisms.To investigate the effect of phenotypic changes in bronchial fibroblasts from asthmatic subjects on epithelial cell proliferation.Epithelial cells and fibroblasts derived from bronchial biopsies of asthmatic and healthy controls were cultured in an engineered model. Proliferation was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium-bromid (MTT). Epidermal growth factor receptor (EGFR), cyclin-dependent kinase inhibitors p21 and p27 were measured by western blots. Total and active forms of transforming growth factor (TGF)-β₁ were measured using ELISA and bioassay. TGF-β was inhibited using a recombinant TGF-β soluble receptor II protein.Proliferation of epithelial cells from asthmatics (AE) is increased when cells were cultured with fibroblasts from normal controls (NF). Fibroblasts from asthmatics (AF) significantly decreased the proliferation of epithelial cells from healthy subjects (NE). Activation of p21, p27, EGFR and TGF-β₁ reflects the proliferation data by decreasing in AE cultured with NF and increasing in NE cultured with AF. Neutralization of TGF-β increased proliferation of epithelial cells cultured in the asthmatic model.Fibroblasts from asthmatic subjects regulate epithelial cell prolifearation, and TGF-β signalling may represent one of the pathway involved in these interactions.
- Published
- 2010
31. Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels, Phase 2: Evaluations of Field Samples and Laboratory Blends
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D. P. Gardiner, M. LaViolette, and M. F. Bardon
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Flammable liquid ,chemistry.chemical_compound ,Materials science ,chemistry ,Waste management ,Phase (matter) ,Petroleum ,Fuel tank ,Ethanol fuel ,Biomass fuels ,Gasoline ,Flammability - Abstract
Study to measure the flammability of gasoline/ethanol fuel vapors at low ambient temperatures and develop a mathematical model to predict temperatures at which flammable vapors were likely to form.
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- 2010
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32. Monitoring sputum eosinophils in mucosal inflammation and remodelling: a pilot study
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Loubaki L, Joanne Milot, L Jayaram, M. Laviolette, F. E. Hargreave, Jamila Chakir, Parameswaran Nair, Sabrina Biardel, L.-P. Boulet, Emilio Pizzichini, and Marcia Margaret Menezes Pizzichini
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Pulmonary and Respiratory Medicine ,Adult ,Male ,Sputum Cytology ,Biopsy ,Cell Count ,Pilot Projects ,Granulocyte ,Eosinophilic ,medicine ,Humans ,Bronchitis ,Asthma ,Bronchus ,medicine.diagnostic_test ,business.industry ,Sputum ,Eosinophil ,medicine.disease ,Eosinophils ,medicine.anatomical_structure ,Immunology ,Airway Remodeling ,Female ,medicine.symptom ,business - Abstract
Normalisation of eosinophil counts in sputum of asthmatic patients reduces eosinophilic exacerbations. However, the effect of this strategy on airway remodelling remains to be determined. We compared bronchial inflammation and collagen deposition after 2 yrs of treatment guided by either sputum eosinophils (sputum strategy, SS) or by clinical criteria (clinical strategy, CS). As a pilot study, 20 mild asthmatic patients were randomly assigned to CS or SS strategies. Bronchial biopsies were obtained when minimum treatment needed to maintain control was identified and this was continued for 2 yrs. Biopsies were immunostained for inflammatory cells, mucin 5A (MUC5A) and collagen. The mean dose of inhaled corticosteroids at the start and end of the study was similar in both SS and CS groups. Forced expiratory volume in 1 s increased in both groups at the study end. In SS, mucosal lymphocyte and eosinophil counts, but not neutrophils, were reduced at the end of the study. In CS, only activated eosinophil and neutrophil counts decreased. MUC5A staining decreased in SS but not CS. No change in collagen deposition underneath the basement membrane was observed in either strategy. Treatment strategies that normalise sputum eosinophils also reduce mucosal inflammatory cells and MUC5A expression, but do not change subepithelial collagen deposition in mild to moderate asthma.
- Published
- 2009
33. Efficacy of Bronchial Thermoplasty (BT) in Patients with Severe Asthma: The AIR2 Trial
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Adalberto Sperb Rubin, M. Laviolette, Neil C. Thomson, and Mario Castro
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medicine.medical_specialty ,Bronchial thermoplasty ,business.industry ,Severe asthma ,Internal medicine ,Medicine ,In patient ,business - Published
- 2009
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34. Influence of lung volume on collateral resistance in normal man
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M. Laviolette, Frédéric Sériès, Y. Cormier, and L. Atton
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Adult ,Male ,Pulmonary and Respiratory Medicine ,Supine position ,Suction ,Physiology ,Posture ,Lumen (anatomy) ,Forced Expiratory Volume ,medicine ,Humans ,Lung volumes ,Lung ,Bronchus ,Pulmonary gas pressures ,business.industry ,Airway Resistance ,Respiration ,Middle Aged ,Normal volunteers ,medicine.anatomical_structure ,Anesthesia ,Female ,Lung Volume Measurements ,Nuclear medicine ,business - Abstract
We measured the influence of changing the end-expiratory lung volume (EELV) on collateral resistance (Rcoll) in 6 normal volunteers (5 male, 1 female, aged 23-45 years). With subjects lying supine in an iron lung, a 5.3 mm fibroscope was introduced under local anesthesia and wedged into a sub-segmental bronchus of the right lower lobe. A truncated 5f Swan-Ganz catheter was tightly fitted into the suction port of the fibroscope. One lumen of the catheter served to deliver a constant flow (200 ml/min) of 5% CO2 in air. The pressure in the wedged segment (Ps) was measured by the other channel. Airway pressure (used as alveolar pressure (Palv)) was determined with a low bias flow catheter taped to the side of the bronchoscope, its tip positioned 20 cm from the end of the bronchoscope. Rcoll was obtained by the formula: Rcoll = (Ps-Palv)/flow. EELV was passively changed by applying a constant extrathoracic pressure in the iron lung at 5 cm H2O steps from 0 to +15 and from 0 to -20 cm H2O. The changes obtained in Rcoll (% baseline, mean +/- SEM) at each extrathoracic pressure (ETP) were: -5 cm H2O, 73 +/- 4%; -10, 56 +/- 7%; -15, 56 +/- 9%; -20, 35 +/- 10%; +5, 118 +/- 6%; +10, 129 +/- 7%; +15, 118 +/- 11%. Rcoll progressively decreased with increasing EELV (negative ETP) and increased slightly as EELV was reduced (positive ETP). The relationship between the log Rcoll and delta EELV was linear; the slope of this line was 9.8%.
- Published
- 1991
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35. Influence of smoking on airway inflammation and remodelling in asthma
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J, St-Laurent, C, Bergeron, N, Pagé, C, Couture, M, Laviolette, and L-P, Boulet
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Adult ,Male ,Smoking ,Cytokines ,Humans ,Epithelial Cells ,Female ,Respiratory Mucosa ,Bronchitis ,Asthma - Abstract
Although exposure to tobacco smoke has been associated with increased morbidity and mortality, cigarette smoking is still common in the asthmatic population. Induced sputum neutrophilia has been observed in asthmatic smokers, but the effects of regular smoking on their bronchial mucosa morphology remain to be defined. This study documents the inflammatory and remodelling features in bronchial biopsies of smoking compared with non-smoking asthmatics.We analysed bronchial biopsies from 24 steroid-naïve young subjects with mild asthma: 12 non-smoking and 12 currently smoking subjects. In addition to airway morphology assessment, inflammation and remodelling were analysed by immunohistochemistry using antibodies against CD3, CD68, major basic protein, neutrophil elastase, and tryptase. Expression of the cytokines IL-4, IL-5, IL-8, IFN-gamma, transforming growth factor-beta, and TNF was determined by in situ hybridization.Compared with non-smoking asthmatic subjects, smoking asthmatics' bronchial mucosa showed squamous cell metaplasia, in addition to increased expression of subepithelial neutrophil elastase, IFN-gamma, and intraepithelial IL-8.Smoking status modifies morphological and inflammatory processes in young subjects with mild asthma. The changes may possibly affect asthma treatment responses and clinical outcomes.
- Published
- 2008
36. 15N enrichment as an integrator of the effects of C and N on microbial metabolism and ecosystem function
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Jeffrey S. Coyle, Egbert Schwartz, Corinne M. LaViolette, Stephen C. Hart, Richard R. Doucett, Paul Dijkstra, and Bruce A. Hungate
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Biogeochemical cycle ,Time Factors ,Nitrogen Isotopes ,Ecology ,Nitrogen ,Climate ,Microbial metabolism ,Heterotroph ,Mineralization (soil science) ,Biology ,complex mixtures ,Carbon ,Soil ,Soil water ,Ecosystem ,Soil microbiology ,Nitrogen cycle ,Ecology, Evolution, Behavior and Systematics ,Soil Microbiology - Abstract
Organic carbon (C) and nitrogen (N) are essential for heterotrophic soil microorganisms, and their bioavailability strongly influences ecosystem C and N cycling. We show here that the natural (15)N abundance of the soil microbial biomass is affected by both the availability of C and N and ecosystem N processing. Microbial (15)N enrichment correlated negatively with the C : N ratio of the soil soluble fraction and positively with net N mineralization for ecosystems spanning semiarid, temperate and tropical climates, grassland and forests, and over four million years of ecosystem development. In addition, during soil incubation, large increases in microbial (15)N enrichment corresponded to high net N mineralization rates. These results support the idea that the N isotope composition of an organism is determined by the balance between N assimilation and dissimilation. Thus, (15)N enrichment of the soil microbial biomass integrates the effects of C and N availability on microbial metabolism and ecosystem processes.
- Published
- 2008
37. In vitro leukotriene (LT) C4 synthesis by blood eosinophils from atopic asthmatics: Predominance of eosinophil subpopulations with high potency for LTC4 generation
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M. Laviolette, Louis-Philippe Boulet, C.J. Roberge, and P.E. Poubelle
- Subjects
Adult ,Male ,medicine.medical_specialty ,Allergy ,Clinical Biochemistry ,Centrifugation ,In Vitro Techniques ,chemistry.chemical_compound ,Internal medicine ,Humans ,Medicine ,Potency ,Asthma ,Leukotriene ,Leukotriene C4 ,business.industry ,Respiratory disease ,Povidone ,Cell Biology ,Middle Aged ,respiratory system ,Eosinophil ,Silicon Dioxide ,medicine.disease ,Blood Cell Count ,Eosinophils ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Immunology ,Female ,SRS-A ,business ,Percoll ,Densitometry - Abstract
We compared the leukotriene (LT) C4 generation by the eosinophil density subpopulations isolated from the blood of asthmatics and normal subjects. Using discontinuous Percoll gradients, eosinophil subpopulations with densities of 1.075, 1.078, 1.081, 1.084, 1.087 and 1.100 g/ml were isolated from the blood of six atopic asthmatics and seven normals. In normals, most eosinophils (94%) were recovered in the density fractions (1.084, 1.087, and 1.100 g/ml). In asthmatics, the eosinophil density profile was shifted towards lower cell density: the eosinophil subsets 1.078, 1.081 and 1.084 g/ml were increased 4.5, 30.3 and 8.9-fold respectively compared to normals (p less than 0.0001); the intermediate subsets, the hypodense 1.081 and normodense 1.084 g/ml fractions being the predominant subpopulations. The ability of asthmatic eosinophil subsets 1.078 to 1.087 g/ml to release LTC4 was measured by reversed-phase HPLC, LTC4 production was highest with the normodense 1.084 g/ml eosinophil subset (149 +/- 28 pmol/10(6) eosinophils, p less than 0.01 compared to the 1.081 fraction). The eosinophils from the hypodense 1.081 g/ml fraction also released more LTC4 (112 +/- 19 pmol/10(6) eosinophils) than the 1.078 and 1.087 g/ml fractions (70 +/- 16 and 67 +/- 12 respectively, p less than 0.01). These results show that, compared to normals, blood of mild atopic asthmatics contains an elevated number of eosinophils of intermediate density which have a high capacity for LTC4 production.
- Published
- 1990
- Full Text
- View/download PDF
38. [Clinical and immunopathological aspects of hypersensitivity pneumonitis]
- Author
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Y, Lacasse, E, Israël Assayag, M, Laviolette, and Y, Cormier
- Subjects
Extracellular Matrix Proteins ,Neutrophils ,Macrophages, Alveolar ,Humans ,Protease Inhibitors ,Pulmonary Surfactants ,Lymphocytes ,Inflammation Mediators ,Bronchoalveolar Lavage Fluid ,Antibodies ,Alveolitis, Extrinsic Allergic - Abstract
Hypersensitivity pneumonitis (HP) is a pulmonary disease with symptoms of dyspnoea and cough resulting from the inhalation of an antigen to which the patient has been previously sensitized.Acute and subacute HP represent the most active forms of the disease which may become chronic while remaining progressive. HP may also evolve to end-stage lung disease. Clinical symptoms and signs tend to be non-specific and the diagnosis of HP often relies on the clinical context. The immune response is initiated when the alveolar macrophage phagocytoses the antigen, provoking the expansion of lymphocytes T and B that reach the pulmonary parenchyma through the systemic circulation. This reaction is amplified by the expression of a number of inflammatory mediators.This article summarizes our current understanding of the diagnostic approach and immunological mechanisms related to HP.
- Published
- 2004
39. Production of tissue-engineered three-dimensional human bronchial models
- Author
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J S, Paquette, P, Tremblay, V, Bernier, F A, Auger, M, Laviolette, L, Germain, M, Boutet, L P, Boulet, and F, Goulet
- Subjects
Tissue Engineering ,Gelatinases ,Microscopy, Electron, Scanning ,Humans ,Bronchi ,Tretinoin ,Cilia ,Laminin ,Respiratory Mucosa ,Fibroblasts ,Immunohistochemistry ,Culture Media - Abstract
We have reported morphological and functional features of cells isolated from human bronchial biopsies. Both epithelial and fibroblastic cells were isolated from the same biopsies using collagenase. A few models have been established to study normal bronchial response to various agents and to understand the mechanisms responsible for some disorders, such as asthma. We produced three-dimensional bronchial equivalents in culture, using human epithelial and fibroblastic cells. We previously showed that peripheral anchorage can prevent the dramatic collagen contraction in gels seeded with fibroblasts when properly adapted to the size and type of cultured tissues. Our bilayered bronchial constructs were anchored and cultured under submerged conditions and at the air-liquid interface. Three culture media were compared. Serum-free medium supplemented with retinoic acid (5 x 10(-8) M) was found to be the best for maintenance of bronchial cell properties in the reconstructed bronchial tissue. Immunohistological and ultrastructural analyses showed that these equivalents present good structural organization, allowing ciliogenesis to occur in culture. Moreover, human bronchial goblet cells could differentiate and secrete mucus with culture time. Laminin, a major constituent of the basement membrane and basal cells, was also detected at the mesenchymoepithelial interface. Such models will be useful for studying human bronchial properties in vitro.
- Published
- 2003
40. Endothelial cells modulate eosinophil surface markers and mediator release
- Author
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M. Laviolette, Pagé N, Francis Davoine, Sophie Lavigne, M.‐J. Dallaire, and Claudine Ferland
- Subjects
Pulmonary and Respiratory Medicine ,Adult ,Antigens, Differentiation, T-Lymphocyte ,Male ,medicine.medical_specialty ,Adolescent ,medicine.medical_treatment ,Biology ,In Vitro Techniques ,Eosinophil migration ,Cell–cell interaction ,Adjuvants, Immunologic ,Antigens, CD ,Cell Movement ,Internal medicine ,medicine ,Humans ,Interferon gamma ,Lectins, C-Type ,Leukotriene ,Lymphokines ,Interleukin ,T-Lymphocytes, Helper-Inducer ,Eosinophil ,Middle Aged ,Asthma ,Leukotriene C4 ,Endothelial stem cell ,Eosinophils ,Endocrinology ,medicine.anatomical_structure ,Cytokine ,Antigens, Surface ,Receptors, Complement 3b ,Female ,Endothelium, Vascular ,Interleukin-4 ,medicine.drug ,Interleukin-1 - Abstract
Migration from blood to tissue modulates eosinophil function, possibly through interactions with endothelial cells. The effects of contact with and migration through endothelial cells on eosinophil expression of surface markers and release of leukotriene C4 were evaluated. A small proportion (2.6%) of eosinophils spontaneously migrated through endothelial cell monolayers. Activation of endothelial cells by interleukin (IL)-4 or IL-1beta slightly increased this migration (to 12.4%), which became much greater when a chemoattractant was placed in the lower chamber (84.3%). However, the chemotactic effect was downregulated by pretreating endothelial cells with interferon gamma (IFN-gamma; 63.1%). At baseline, 5% of eosinophils expressed CD69; this increased to 30.7% in culture on untreated endothelial cells and to 50.9% on IL-1beta-pretreated endothelial cells. This effect was mediated through intercellular adhesion molecule-1/CD11b interaction. Eosinophil migration through endothelial cells further increased CD69 expression to 63.9% and also increased CD35 expression from 83.3 to 91.3%. Upon stimulation, eosinophils that had migrated through endothelial cells produced more leukotriene C4 than control cells (872.4 and 103.9 pg x mL(-1), respectively). Endothelial cell pretreatment with IL-4 or IL-1beta further increased leukotriene C4 release (1,789.1 and 2,895.1 pg x mL(-1), respectively), whereas pretreatment with IFN-gamma decreased it (293.7 pg x mL(-1)). These data show that in vitro interactions with endothelial cells upregulate eosinophil membrane receptor expression and mediator release and that these effects are differently modulated by T-helper cell type 1 and 2 cytokines. These eosinophil modulations may play an important role in asthma pathogenesis.
- Published
- 2003
41. Bronchial inflammation in corticosteroid-sensitive and corticosteroid-resistant asthma at baseline and on oral corticosteroid treatment
- Author
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J, Chakir, Q, Hamid, M, Bossé, L-P, Boulet, and M, Laviolette
- Subjects
Adult ,Inflammation ,Male ,Anti-Inflammatory Agents ,Administration, Oral ,Bronchi ,Respiratory Mucosa ,Adrenergic beta-Agonists ,Methylprednisolone ,Asthma ,Leukocyte Count ,Forced Expiratory Volume ,Administration, Inhalation ,Humans ,Female ,Adrenergic beta-2 Receptor Agonists ,Glucocorticoids - Abstract
Pathophysiology of corticosteroid (CS)-resistant asthma remains incompletely understood.To determine if failure of asthma to clinically improve with CS is due to a defective response of airway bronchial inflammation to these drugs.Twenty-one asthmatics having a decreased baseline FEV1 that improvedor= 30% with inhaled beta2 agonist got bronchial biopsies before and at the end of an oral CS treatment (methylprednisolone 40 mg daily for 14 days). They were arbitrarily divided into two groups according to baseline FEV1 improvement following this treatment:or= 23% designated as CS-sensitive (CSS) (n = 10) and15% as CS-resistant (CSR) (n = 11).Before oral CS, counts of bronchial mucosa inflammatory cells identified by immunohistochemistry (CD3, MBP, tryptase, CD68, neutrophil elastase and CD25 for lymphocytes, eosinophils, mast cells, macrophages, neutrophils and IL-2 receptors, respectively) were similar in CSS and CSR subjects. Oral CS decreased CD3+ cell counts (medians: 60-20 cells/mm(2); P = 0.014) and MBP+ cell counts (medians: 19-4 cells/mm(2); P = 0.03) in CSS asthmatics, but only tryptase+ cell counts in CSR asthmatics (medians: 30-18 cells/mm(2); P = 0.05). Few bronchial neutrophil elastase+ cells were observed and their counts were similar in the two groups of asthmatics before and when on oral CS (all medians: = 2 cells/mm(2)).These data show that, in these subjects with moderate to severe asthma, lymphocytes and eosinophils constitute most of the inflammatory cells infiltrating the bronchial mucosa. They also demonstrated that clinical impaired response to CS is associated with a persistent bronchial mucosa cellular infiltrate despite oral CS treatment. Additional studies are required to determine the role of this CS-resistant bronchial inflammation in the impaired asthma clinical response to these drugs.
- Published
- 2002
42. Synergistic action of endothelin (ET)-1 on the activation of bronchial fibroblast isolated from normal and asthmatic subjects
- Author
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J, Dubé, J, Chakir, C, Dubé, Y, Grimard, M, Laviolette, and L P, Boulet
- Subjects
Platelet-Derived Growth Factor ,Analysis of Variance ,Endothelin-1 ,Becaplermin ,Bronchi ,DNA ,Proto-Oncogene Proteins c-sis ,Fibroblasts ,Asthma ,Dexamethasone ,Current Status Review ,Transforming Growth Factor beta ,Case-Control Studies ,Humans ,Glucocorticoids ,Cell Division ,Cells, Cultured ,Procollagen - Abstract
Bronchial subepithelial fibrosis is an histological characteristic of asthma. Cytokines and other mediators, such as PDGF-BB, TGF-beta1 and ET-1 found in the asthmatic submucosa can potentially activate a repair process that leads to fibroblast proliferation and collagen synthesis. The mechanisms of modulation of the repair process leading to extracellular matrix deposition are still to be documented. In this study, we assessed the in vitro proliferation and collagen synthesis of bronchial fibroblasts isolated from normal and asthmatic subjects in response to ET-1, platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-beta1 alone or in combination, in the presence or absence of dexamethasone. The combination of ET-1 with one of the other two growth factors, or the triple combination, significantly increased DNA synthesis and collagen production of bronchial fibroblasts isolated from both normal and asthmatic subjects, but the same growth factors used separately had no significant effect on the same parameters. These results suggest that the simultaneous presence of ET-1, PDGF-BB and TGF-beta1 in both normal and asthmatic subjects is necessary to activate bronchial fibroblast proliferation and collagen synthesis. As these mediators are present in the submucosa of the asthmatic bronchi, they could be responsible, at least in part, for the accumulation of collagen in the mucosa.
- Published
- 2001
43. Effect of salmeterol on allergen-induced airway inflammation in mild allergic asthma
- Author
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L P, Boulet, J, Chakir, J, Milot, M, Boutet, and M, Laviolette
- Subjects
Adult ,Inflammation ,Male ,Cross-Over Studies ,Adolescent ,Respiratory System ,Allergens ,Asthma ,Bronchodilator Agents ,Treatment Outcome ,Double-Blind Method ,Humans ,Albuterol ,Female ,Salmeterol Xinafoate - Abstract
A previous study suggested that the long-acting beta2-adrenergic agonist salmeterol (SM) had inhibitory effects on bronchial mucosal inflammation 6 hours after allergen exposure. To further evaluate the influence of SM on allergen-induced airway inflammation. We studied, in a randomized, double-blind, cross-over trial, 16 mild asthmatic patients who had a dual asthmatic response to allergen inhalation. Subjects received 50 microg of SM or placebo (P), twice daily for 1 week each, separated by a 2-week wash-out period. At the end of each treatment period, after withholding SM for 24 h, they had a methacholine inhalation test (medication was resumed after the test), followed 24 h later by an AC with the concentration of allergen that had induced a LAR at baseline. Airway inflammation was assessed 24 h after the AC by bronchoalveolar lavage (BAL) (n = 16) and bronchial biopsies (n = 13). As expected, SM improved baseline FEV1 and PC20 (Por = 0.009) and decreased the allergen-induced early bronchoconstrictive response. There were no significant differences in BAL cell counts after the two treatments. On bronchial biopsies, numbers (median, mm2) of submucosal CD45 (P: 43 +/- 23; SM: 161 +/- 43, P = 0.031), CD45Ro (P: 37 +/- 19; SM: 126 +/- 41, P = 0.047) and AA1 positive cells (P: 38 +/- 6, SM: 65 +/- 17, P = 0.006) were significantly higher after SM than P treatment. The numbers of CD4 (P: 11 +/- 10; SM: 32 +/- 7, P = 0.085), HLA-DR (P: 65 +/- 30; SM: 116 +/- 36, P = 0.079) and EG2 positive cells (P: 25 +/- 15; SM: 38 +/- 26, P = 0.09) tended to increase with SM treatment. In summary, compared to placebo, 1 week of regular use of SM is associated with an increase in bronchial inflammatory cells 24 h after AC. This is in keeping with the recommendation that salmeterol should only be used with an anti-inflammatory agent, particularly in the context of significant allergen exposure.
- Published
- 2001
44. La thermoplastie bronchique : nouvelle approche en cours d’investigation dans le traitement de l’asthme
- Author
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M. Laviolette
- Subjects
Pulmonary and Respiratory Medicine ,business.industry ,Medicine ,business - Published
- 2009
- Full Text
- View/download PDF
45. Montelukast added to inhaled beclomethasone in treatment of asthma. Montelukast/Beclomethasone Additivity Group
- Author
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M, Laviolette, K, Malmstrom, S, Lu, P, Chervinsky, J C, Pujet, I, Peszek, J, Zhang, and T F, Reiss
- Subjects
Adult ,Cyclopropanes ,Male ,Adolescent ,Beclomethasone ,Administration, Oral ,Acetates ,Middle Aged ,Sulfides ,Asthma ,Double-Blind Method ,Forced Expiratory Volume ,Administration, Inhalation ,Chronic Disease ,Quinolines ,Humans ,Leukotriene Antagonists ,Drug Therapy, Combination ,Female ,Single-Blind Method ,Anti-Asthmatic Agents ,Glucocorticoids ,Aged - Abstract
The primary objective of this study was to determine whether montelukast, an oral leukotriene receptor antagonist, provides additional clinical benefit to the effect of inhaled corticosteroids. A total of 642 patients with chronic asthma (FEV(1) 50 to 85% of predicted value and at least a predefined level of asthma symptoms) incompletely controlled with inhaled beclomethasone, 200 microg twice daily using a spacer device, during the 4-wk run-in period were randomly allocated, in a double-blind, double-dummy manner to one of four treatment groups: (1) montelukast 10 mg plus continuing inhaled beclomethasone; (2) placebo tablet plus continuing inhaled beclomethasone; (3) montelukast 10 mg and inhaled placebo (after blind beclomethasone removal); and (4) placebo tablet and inhaled placebo (after blind beclomethasone removal). The primary endpoints were FEV(1) and daytime asthma symptoms score. Montelukast provided significant (p0.05) clinical benefit in addition to inhaled beclomethasone by improving FEV(1), daytime asthma symptom scores, and nocturnal awakenings. Blind removal of beclomethasone in the presence of placebo tablets caused worsening of asthma control, demonstrating that patients received clinical benefit from inhaled corticosteroids. Blind removal of beclomethasone in the presence of montelukast resulted in less asthma control but not to the level of the placebo group. All treatments were well tolerated; clinical and laboratory adverse experiences were generally similar to placebo treatment in this study. In conclusion, montelukast provided additional asthma control to patients benefitting from, but incompletely controlled on, inhaled beclomethasone.
- Published
- 1999
46. Asymptomatic airway hyperresponsiveness: relationships with airway inflammation and remodelling
- Author
-
Catherine Laprise, M. Laviolette, Louis-Philippe Boulet, and M. Boutet
- Subjects
Pulmonary and Respiratory Medicine ,Spirometry ,Adult ,Male ,Pathology ,medicine.medical_specialty ,Adolescent ,Biopsy ,T-Lymphocytes ,Bronchi ,Asymptomatic ,Gastroenterology ,Leukocyte Count ,Fibrosis ,Internal medicine ,Bronchoscopy ,medicine ,Humans ,Bronchitis ,Asthma ,medicine.diagnostic_test ,business.industry ,Respiratory disease ,respiratory system ,Immunoglobulin E ,Middle Aged ,medicine.disease ,Prognosis ,respiratory tract diseases ,Eosinophils ,medicine.anatomical_structure ,Methacholine ,Female ,medicine.symptom ,Bronchial Hyperreactivity ,business ,Airway ,medicine.drug ,Respiratory tract ,Follow-Up Studies - Abstract
To study the physiopathology and significance of asymptomatic airway hyperresponsiveness (AHR), the clinical and bronchial immunohistological parameters were evaluated in subjects with asymptomatic and symptomatic AHR. Asymptomatic subjects with AHR (eight females/two males, no respiratory symptoms, provocative concentration of methacholine causing a 20% fall in forced expiratory volume in one second (PC20)
- Published
- 1999
47. Skin bruising, adrenal function and markers of bone metabolism in asthmatics using inhaled beclomethasone and fluticasone
- Author
-
J L, Malo, A, Cartier, H, Ghezzo, S, Mark, J, Brown, M, Laviolette, and L P, Boulet
- Subjects
Male ,Cross-Over Studies ,Hydrocortisone ,Administration, Topical ,Contusions ,Osteocalcin ,Anti-Inflammatory Agents ,Beclomethasone ,Middle Aged ,Skin Diseases ,Asthma ,Androstadienes ,Double-Blind Method ,Administration, Inhalation ,Fluticasone ,Humans ,Female ,Anti-Asthmatic Agents ,Prospective Studies - Abstract
Fluticasone propionate (FP) is generally considered to have twice the efficacy of beclomethasone dipropionate (BDP) on a weight-to-weight basis for the control of asthma, and may have lesser effects on adrenal function. However, the effects of FP and BDP on skin integrity and bone metabolism markers require further examination. Sixty-nine asthmatic subjects were enrolled in a double-blind crossover study in which, after a baseline period, they received BDP or FP (at half the dose of BDP) for two 4-month periods each. A questionnaire on skin bruising, a skin examination, tests of adrenal function and of markers of bone metabolism were performed after 2 months of each period. The number of asthma exacerbations was not significantly different for the two treatment periods (eight for BDP and nine for FP), nor were various indices of asthma control. Whereas the frequency of bruising reported by the questionnaire was not different, there were more bruises on examination for BDP (1.6+/-2.5) than for FP (1.2+/-2.3) (p=0.04). Although baseline serum cortisol was not significantly different for the two drugs, the increase in cortisol after cortrosyn was lower for BDP (357+/-158 micromol x dL(-1)) than for FP (422+/-144 micromol x dL(-1)) (p0.01). Serum osteocalcin levels were significantly lower in subject on BDP (2.8+/-1.7 microg x mL(-1)) than on FP (3.5+/-1.9 ng x mL(-1)) (p=0.003). Other markers of bone metabolism were not significantly altered. The three major side-effects were loosely, but significantly correlated with the periods on BDP and FP. However, skin bruises, increase in cortisol after Cortrosyn and osteocalcin were not significantly correlated for the period on either BDP or FP. In conclusion, whereas fluticasone propionate used at half the dose of beclomethasone dipropionate has a comparable effect on the control of asthma, fluticasone propionate demonstrated fewer side-effects in terms of skin bruising, adrenal suppression and bone metabolism.
- Published
- 1999
48. Murine Model of Allergic Bronchopulmonary Aspergillosis
- Author
-
P. Dussault, M. Laviolette, and G.M. Tremblay
- Subjects
education.field_of_study ,Pathology ,medicine.medical_specialty ,Lung ,medicine.diagnostic_test ,biology ,business.industry ,Population ,Inflammation ,respiratory system ,medicine.disease ,Alveolar cells ,Bronchoalveolar lavage ,medicine.anatomical_structure ,Antigen ,biology.protein ,Medicine ,medicine.symptom ,Antibody ,Allergic bronchopulmonary aspergillosis ,business ,education - Abstract
Publisher Summary This chapter presents a murine model of allergic bronchopulmonary aspergillosis (ABPA). Several strains and forms of Aspergillus fumigates (Af) can be used to induce ABPA in mice. For this model, a strain of Af (local Af) from an air sample of swine confinement buildings is isolated. The inoculum comes from a 3-day-old culture of Af on Sabouraud malt extract agar slant tubes. C57B1/6 mice are lightly anesthetized with isoflurane, and then 50 μl of antigen (100 lag dry weight) is administered at the tip of the nose with a micropipette. The bronchoalveolar lavage (BAL) is used to assess the alveolar cell population and to measure the different immunoglobulins, cytokines, and mediators present in the epithelial lining fluid. After euthanasia by cervical dislocation, the trachea is exposed, incised, and cannulated with a 21-gauge catheter. Serological assays such as biotin-streptavidin-linked immunosorbent assay (BSELISA), are used to detect total IgE, total IgG1, and specific IgG1 antigen in BAL fluid and sera. The induced inflammation is mostly restricted to the lung. Any modifications in physical appearance, body weight loss, and food and water intake indicates the occurrence of another inflammatory or infectious process. In Af-challenged mice, the expression of intercellular adhesion molecule-1 (ICAM-1) is up-regulated on endothelial cells of arteries, arterioles, veins, and venules as on bronchial and alveolar epithelial cells and alveolar macrophages.
- Published
- 1999
- Full Text
- View/download PDF
49. Three-dimensional production of bronchi in vitro
- Author
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J S, Paquette, F, Goulet, L P, Boulet, M, Laviolette, N, Tremblay, J, Chakir, L, Gennain, and F A, Auger
- Subjects
Cell Culture Techniques ,Humans ,Bronchi ,Epithelial Cells ,Collagen ,Fibroblasts ,Gels - Published
- 1998
50. Mechanisms of corticosteroid resistance in asthma: role of airway remodelling
- Author
-
M, Laviolette, M, Bossé, J, Chakir, and L P, Boulet
- Subjects
Inflammation ,Adrenal Cortex Hormones ,Forced Expiratory Volume ,Drug Resistance ,Humans ,Bronchial Hyperreactivity ,Asthma - Published
- 1998
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