55 results on '"G. Ostiguy"'
Search Results
2. Le développement athlétique des jeunes : synthèse ReFORM de la position de consensus du CIO
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M. Moroz, G. Ostiguy, F. Delvaux, C. Nuehrenboerger, S. Nguyen, J.-F. Kaux, M. Schindler, R. Seil, and G. Martens
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Orthopedics and Sports Medicine - Published
- 2022
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3. Human acute neurophysiological perceptions associated with ELF flux densities up to 50 mT
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G. Ostiguy, M. Plante, Alexandre Legros, Julien Modolo, Jacques Lambrozo, D. Goulet, Martine Souques, F. Deschamps, Lawson Health Research Institute, Institut de Recherche d'Hydro-Québec [Varennes] (IREQ), Laboratoire Traitement du Signal et de l'Image (LTSI), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), EDF (EDF), Electric Power Research Institute, EPRIHydro-QuébecCanadian Institutes of Health Research, CIHR, and Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)
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media_common.quotation_subject ,Small Sample Size ,Flux ,Neurophysiology ,Human study ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,Nuclear magnetic resonance ,Perception ,Extremely low frequency ,Extremely lowfrequency magnetic fields (ELF) ,ComputingMilieux_MISCELLANEOUS ,Neurophysiological perception ,media_common ,Perception thresholds ,Physics ,Lower frequencies ,Small sample ,Human exposure ,Frequency dependent ,Detection rates ,[SDV.IB]Life Sciences [q-bio]/Bioengineering ,Detection rate ,Electromagnetic field effects ,Replicated experiment ,030217 neurology & neurosurgery - Abstract
Current guidelines and recommendations limiting human exposure to extremely low frequency (ELF) magnetic field (MF) are based on the most reliable acute human neurophysiological exposure responses. However, the currently available perception thresholds are established on small sample size and non-replicated experiments. The current human study aimed to test MF levels leading to mahnetophosphenes perceptions at 20, 50, 60 and 100 Hz. Perception reported button-press were recorded in these 4 frequency groups in 55 randomly assigned magnetic flux density conditions. Results showed a frequency-dependent threshold for initial perception: 2.51 T/s at 20 Hz, 6.28 T/s at 50 Hz, 7.54 T/s at 60 Hz, and 12.57 T/s at 100 Hz; and for the 50% detection rate: 4.73 T/s at 20 Hz, 8.83 T/s at 50 Hz, 10.55 T/s at 60 Hz, and 33.46 T/s at 100 Hz. Since it is a linear correlate of the induced in-situ E-fields, the dB/dt metric was chosen to analyse the the data. It confirmed lower magnetophoshene perception at lower frequencies for a similar in-situ induced E-field.
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- 2019
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4. Acute neurophysiological response to ELF-MF and magnetophosphene perception
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Alexandre Legros, Julien Modolo, G. Ostiguy, P. Cabanes, F. Deschamps, M. Corbacio, Jacques Lambrozo, D. Goulet, Martine Souques, C. Baker, and M. Plante
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business.industry ,General Neuroscience ,media_common.quotation_subject ,Biophysics ,Neurophysiology ,Magnetophosphene ,lcsh:RC321-571 ,Perception ,Medicine ,Neurology (clinical) ,business ,Neuroscience ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,media_common - Published
- 2019
5. Magnetophospenes in humans exposed to ELF MF up to 50 mT, a threshold study
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J. Lambrozo, F. Deschamps, G. Ostiguy, Alex W. Thomas, M. Corbacio, M. Plante, Alexandre Legros, Souques M, Julien Modolo, and D. Goulet
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Physics ,Nuclear magnetic resonance ,Eeg data ,medicine.diagnostic_test ,medicine ,Small sample ,Extremely low frequency ,Electroencephalography ,Magnetophosphene - Abstract
Although magnetophosphene perception is the most reliable reported effect on acute human neurophysiological responses to extremely low frequency (ELF) magnetic field (MF) exposure, current knowledge is based on small sample size, non-replicated experiments. In this study, we established MF levels triggering magnetophosphenes at 20, 50, 60 and 100 Hz in humans. Magnetophosphene perception and EEG were collected in 55 magnetic flux density conditions randomly delivered in each frequency group (2 experiments, total n=145). Results indicate that threshold values 1) need to be reported as a function of dB/dt instead of flux density, and 2) are frequency-dependent (higher sensitivity to lower frequencies). No clear trend was found in EEG data.
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- 2018
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6. Human acute neurophysiological responses to magnetically-induced alternating current densities of up to 100 mA.m-2
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F. Deschamps, D. Goulet, G. Ostiguy, Sebastien Villard, Alexandre Legros, M. Souques, S. Davarpanah Jazi, Julien Modolo, M. Corbacio, and M. Plante
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Physics ,law ,General Neuroscience ,Biophysics ,Neurology (clinical) ,Neurophysiology ,Alternating current ,Neuroscience ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,law.invention ,lcsh:RC321-571 - Published
- 2017
7. Smart Meters and Routers Radiofrequency Disturbances Study with Pacemakers and Implantable Cardiac Defibrillators
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Tom Black, Louis-Jean Bluteau, Guillaume Girard, Katia Dyrda, M. Plante, D.H. Nguyen, G. Ostiguy, Louis Dupont, and Bernard Thibault
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business.industry ,Smart meter ,Electrical engineering ,Metre ,Medicine ,In vitro study ,General Medicine ,Cardiology and Cardiovascular Medicine ,business ,Telecommunications - Abstract
Background There is no scientific literature that examines radiofrequency (RF) interference from Smart Meters with cardiac implantable electronic devices (CIEDs). The objective of this in vitro study was to assess any potential interference with Medtronic CIEDs (Medtronic Inc., Minneapolis, MN, USA). Methods In the Quebec testing, five models of Medtronic CIEDs were placed in an acrylic cylinder filled with a saline solution and faced a Landis+Gyr Smart Meter or Router (Landis+Gyr AG, Zug, Switzerland). The distance between CIEDs and the meter casing or router antenna was 10 cm. The Meter's normal operating conditions were modified to artificially set the number of impulsions at an abnormally high level (one, two, and three impulses per second). Each scenario was repeated one to five times, for 1 minute each. In the U.S. testing, 6 cm and 15 cm (∼2.25′ and ∼6′) separated the six models of Medtronic CIEDs from the Schlumberger Smart Meter (Itron Inc., Liberty Lake, WA, USA), which generally sent out a 96-bit Standard Consumption Message over 3 seconds. The transmission varied in frequencies along with the interval between cycles. Results A total of 6,966 RF transmissions were completed during the 34 tests conducted in Quebec. In the United States, the CIED was exposed to the meter for 10 minutes to provide a minimum of 200 completed RF transmissions. No interference was observed in worst-case scenarios (testing of meters and CIEDs at their performance limits). Conclusions Landis+Gyr Smart Meters/Routers and Schlumberger Smart Meters do not interfere with the functioning of the Medtronic CIEDs tested, when placed, respectively, 10 cm and 6 cm and 15 cm apart.
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- 2013
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8. Impact of electromagnetic fields on human vestibular system and standing balance: Pilot results and future developments
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G. Ostiguy, Jacques Lambrozo, M. Plante, Alex W. Thomas, Martine Souques, A. Allen, M. Corbacio, Alexandre Legros, Julien Modolo, F. Deschamps, and D. Goulet
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Vestibular system ,Acute effects ,Electromagnetic field ,Physics ,medicine.medical_specialty ,Standing balance ,Center of pressure (terrestrial locomotion) ,business.industry ,medicine ,Electrical engineering ,Audiology ,business ,Electric stimulation - Abstract
Although a few studies have found that extremely low-frequency (ELF, < 300 Hz) magnetic fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields (EMF) on standing balance have not been systematically investigated. This work aims to establish the threshold for standing balance modulation during ELF MF exposure. One hundred volunteers will be exposed to an ELF MF (0 to 160 Hz, 0 to 100 mT) and stimulated using transcranial electric stimulation (DC and AC, 1 mA). The displacement of their center of pressure will be collected and analyzed using validated sway characteristics to detect modulations of vestibular function. Future protocols will be designed to test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.
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- 2015
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9. Human magnetophosphene perception and EEG response to 50 and 60 Hz magnetic stimuli up to 50 mT
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F. Deschamps, G. Ostiguy, Alex W. Thomas, Martine Souques, D. Goulet, Alexandre Legros, Julien Modolo, M. Plante, and Jacques Lambrozo
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medicine.medical_specialty ,medicine.diagnostic_test ,General Neuroscience ,media_common.quotation_subject ,Biophysics ,Electroencephalography ,Audiology ,Magnetophosphene ,lcsh:RC321-571 ,Perception ,medicine ,Neurology (clinical) ,Psychology ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,media_common - Published
- 2015
10. RESISTANCE OF THE MEDTRONIC MICRA LEADLESS PACEMAKER TO 60 HZ ELECTRICAL FIELDS
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Katia Dyrda, Marc Dubuc, Blandine Mondésert, G. Ostiguy, Peter G. Guerra, Laurent Macle, Paul Khairy, D. Nguyen, Denis Roy, M. Audoubert, Lena Rivard, Bernard Thibault, Mario Talajic, and M. Plante
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business.industry ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,Biomedical engineering - Published
- 2017
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11. P1504Resistance of the medtronic micra leadless pacemaker to 60 hz electrical fields
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Laurent Macle, G. Ostiguy, Lena Rivard, Denis Roy, Katia Dyrda, Peter G. Guerra, Marc Dubuc, Blandine Mondésert, Paul Khairy, M. Plante, Bernard Thibault, Mario Talajic, M. Audoubert, and Dh. Nguyen
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business.industry ,Physiology (medical) ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,Biomedical engineering - Published
- 2017
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12. Stress-strain hysteresis and damping in MnCu and NiTi alloys
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François Trochu, G. Ostiguy, and S. De Santis
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Vibration ,Hysteresis ,Materials science ,Mechanics of Materials ,Loss factor ,Metallurgy ,Dynamic modulus ,Stress–strain curve ,Metals and Alloys ,Phase (waves) ,Titanium alloy ,Shape-memory alloy ,Condensed Matter Physics - Abstract
Uniaxial stress-strain hysteresis loops for high damping manganese-copper (MnCu) and nickel-titanium (NiTi) shape memory alloys are experimentally determined. The characterization concerns two MnCu samples, one containing 60 pct Mn, the other 40 pct Mn, and two NiTi samples, one in the martensitic phase and the other in the austenitic phase at room temperature. In the 225 to 360 Hz frequency range, tests are conducted using a vibration exciter; for lower frequencies (2Hz), we use a Material Test System (MTS) servohydraulic apparatus. The ensuing characterization allows us to compute the energy dissipated per unit volume per cycle, the dynamic modulus, and the loss factor as a function of frequency and strain amplitude. The sensitivity of these results to such factors as frequency, temperature increments during the tests, and vibration duration are discussed. The experimental stress-strain characterization is also used to express the tangent stiffness along the stress-strain path as an analytical function of strain (within the vibration cycle) and strain amplitude using kriging interpolation. Behavioral differences both between the alloys and also from equivalent linear viscous models are discussed.
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- 2001
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13. INTERFERENCE RESISTANCE OF PACEMAKERS AND DEFIBRILLATORS TO 60 HZ ELECTRIC FIELDS
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G. Ostiguy, Marc Dubuc, Peter G. Guerra, Katia Dyrda, Blandine Mondésert, D. Nguyen, S. Venier, Paul Khairy, Mario Talajic, Bernard Thibault, Lena Rivard, Laurent Macle, and M. Plante
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business.industry ,Electric field ,Electrical engineering ,Medicine ,Cardiology and Cardiovascular Medicine ,business ,Interference resistance - Published
- 2015
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14. Material and Structural Characterization of the Dynamic Behavior of Shape Memory Alloy Reinforced Composites
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François Trochu, G. Ostiguy, J. M. Berthelot, H. Sol, S. De Santis, Structural Analysis, Mechanics of Materials and Constructions, and Vrije Universiteit Brussel
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Materials science ,business.industry ,Mechanical Engineering ,Modal analysis ,Composite number ,Stiffness ,02 engineering and technology ,Fiber-reinforced composite ,Structural engineering ,Shape-memory alloy ,021001 nanoscience & nanotechnology ,Finite element method ,020303 mechanical engineering & transports ,Modal ,0203 mechanical engineering ,Mechanics of Materials ,Materials Chemistry ,Ceramics and Composites ,medicine ,Boundary value problem ,Composite material ,medicine.symptom ,0210 nano-technology ,business - Abstract
The purpose of this article is to characterize elastic and dissipative properties of Shape Memory Alloy (SMA) fiber reinforced composite materials. These properties are then used to evaluate the dynamic characteristics of a structure (modal parameters) using finite elements. A laminate level procedure is used to evaluate the complex bending stiffnesses of CuZnAl fiber reinforced composites. The modal strain energy finite element method is implemented to calculate the modal parameters of composite structures with different geometries and boundary conditions. Calculated results are compared to those obtained by experimental modal analysis. The study outlines the relatively good agreement of natural frequencies and the difficulties encountered in evaluating damping in these types of composites at both the experimental (modal analysis) as well as the numerical (finite element) levels.
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- 1997
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15. RESISTANCE OF THE SUBCUTANEOUS INTERNAL CARDIOVERTER DEFIBRILLATOR TO 60 HZ ELECTRIC FIELDS
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Paul Khairy, Blandine Mondésert, D. Nguyen, Bernard Thibault, Lena Rivard, G. Ostiguy, Peter G. Guerra, M. Audoubert, Denis Roy, M. Plante, Mario Talajic, Katia Dyrda, Marc Dubuc, and Laurent Macle
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Cardioverter-Defibrillator ,medicine.medical_specialty ,business.industry ,Electric field ,Internal medicine ,Cardiology ,Medicine ,Cardiology and Cardiovascular Medicine ,business - Published
- 2016
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16. Respiratory health of workers exposed to metal dusts and foundry fumes in a copper refinery
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G Ostiguy, C Vaillancourt, and R Bégin
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Adult ,Male ,Spirometry ,medicine.medical_specialty ,Cross-sectional study ,medicine.disease_cause ,Asbestos ,Occupational medicine ,Internal medicine ,medicine ,Humans ,Longitudinal Studies ,Lung Diseases, Obstructive ,Respiratory health ,Aged ,Analysis of Variance ,COPD ,medicine.diagnostic_test ,business.industry ,Smoking ,Respiratory disease ,Public Health, Environmental and Occupational Health ,Dust ,Middle Aged ,Pleural Diseases ,respiratory system ,medicine.disease ,respiratory tract diseases ,Surgery ,Occupational Diseases ,Cross-Sectional Studies ,medicine.anatomical_structure ,Metallurgy ,Female ,Gases ,Lung Diseases, Interstitial ,business ,Copper ,Research Article ,Respiratory tract - Abstract
OBJECTIVES--To assess airflow limitation in workers exposed long term to metal dust, the prevalence of pleural plaques in those workers exposed in the past to asbestos, the influence of pleural plaques on lung function, and the possible association with airway disease caused by asbestos. METHODS--A cross sectional and longitudinal (seven year) survey of 494 long term (mean (SEM) 21(1) years) workers in a copper refinery was carried out from medical questionnaires, chest radiographs, and forced spirometry. RESULTS--The prevalence of lifetime non-smokers was 19%, current smokers 39%, and ex-smokers 42%. The prevalence of chronic obstructive pulmonary diseases (COPD) (forced expiratory volume in one second (FEV1) < 80% predicted) was 5%, small airway dysfunction (SAD) (maximal mid-expiratory flow (MMEF) < 60% predicted) was 7%, and this did not differ from the control population. The COPD and SAD were associated with cumulative smoking index but not with the cumulative work years at the plant or with any type of work at the plant. The mean (SEM) reduction of FEV1 was 20(7) ml in non-smokers, 26(4) ml in smokers, and 26(5) ml in ex-smokers (P > 0.05). In the smokers and ex-smokers with COPD, the loss of FEV1 was 53(10) (P < 0.02). The prevalence of pleural plaques was 11% (P < 0.0001); pleural plaques were found in older workers with known exposure to asbestos. The pleural plaques were circumscribed and associated with a non-significant 196 ml reduction in forced vital capacity (FVC) and non-significant reduction of FVC over time. The pleural plaques were not associated with COPD or SAD. The cumulative smoking index obtained by a technician did not differ from that by a chest physician. CONCLUSIONS--Despite exposures to asbestos that produced pleural plaques and exposures to metal dusts and foundry fumes the long term workers of this plant did not have excessive prevalence of COPD or SAD. The data suggest that low level long term exposure to metal dusts, gases, and foundry fumes do not necessarily cause respiratory dysfunction, circumscribed pleural plaques with low grades of width and extent do not reduce FVC significantly, and exposure to asbestos dust that produced pleural plaques does not necessarily produce airway dysfunction.
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- 1995
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17. Impact of electromagnetic fields on human vestibular system and standing balance: pilot results and future developments
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Alexandre Legros, Sebastien Villard, M. Corbacio, F. Deschamps, M. Plante, G. Ostiguy, Jacques Lambrozo, Alex W. Thomas, D. Goulet, Martine Souques, and A. Allen
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Electromagnetic field ,Vestibular system ,Acute effects ,medicine.medical_specialty ,business.industry ,Audiology ,030218 nuclear medicine & medical imaging ,law.invention ,03 medical and health sciences ,Standing balance ,0302 clinical medicine ,Center of pressure (terrestrial locomotion) ,Protocol design ,law ,medicine ,business ,Alternating current ,030217 neurology & neurosurgery ,Biomedical engineering - Abstract
Although studies have found that extremely low-frequency (ELF, < 300 Hz) magnetic fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields on standing balance have not been systematically investigated. This work aims to establish the threshold for acute standing balance modulation during ELFMF exposure. One hundred volunteers will be exposed to transcranial electric stimulations (Direct Current - DC and Alternating Current - AC, 1 mA) and ELFMF (0 to 160 Hz, 0 to 100 mT). The displacement of their center of pressure will be collected and analyzed as an indicator of vestibular performance. During pilot testing (n=6), we found increased lateral sway with DC, and to a lesser extent, AC exposure. The ELFMF exposure system still needs to be adapted to allow meaningful results. Future protocol design will test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.
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- 2016
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18. Summary of the task force report on occupational respiratory disease
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G, Ostiguy and C A, Guenter
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Correspondence - Published
- 2010
19. Results FROM THE PACEMAKER AND DEFIBRILLATOR ELECTROMAGNETIC INTERFERENCE REGISTRY (P-DIEM)
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Paul Khairy, Marc Dubuc, G. Ostiguy, Bernard Thibault, Denis Roy, D. Goulet, Jason G. Andrade, Peter G. Guerra, M. Plante, Lena Rivard, Laurent Macle, Katia Dyrda, and Mario Talajic
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business.industry ,medicine ,Medical emergency ,Cardiology and Cardiovascular Medicine ,medicine.disease ,business ,Electromagnetic interference - Published
- 2014
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20. [Quebec spirometry reference values]
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R R, Martin, H, Ghezzo, R, Amyot, R, Bégin, M, Desmeules, J J, Gauthier, J L, Malo, and G, Ostiguy
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Adult ,Male ,Reference Values ,Spirometry ,Respiratory Tract Diseases ,Quebec ,Humans ,Female ,Forced Expiratory Flow Rates ,Middle Aged ,Aged - Abstract
Lung volumes forced expiratory flow rates and carbon monoxide diffusing capacity (apnea) were measured in 397 non-smoking, nonatopic, asymptomatic subjects (219 women, 178 men). The equipments and methods for measurements met the ATS criteria. The linear regression of the different variables according to age and height allowed the elaboration of a new set of predictive equations (Quebec). When comparing the different reference values used in North America and Europe, it is found that those of Miller and associates as well as those recommended by the CECA provide the best description of the Quebec situation. However, we would eventually prefer the reference values of Miller and associates over those of the CECA, because they better fit the current ATS criteria and also provide references for smokers. Lung volumes and forced expiratory flow rates of 97 non-smoking, nonatopic, asymptomatic manual workers were measured in the same conditions and submitted to the same comparisons. Quebec predictive values as well as those of Miller and associates isolated the same individuals in the so called abnormal zone. We therefore conclude that Quebec's standards should be preferred in the Province of Quebec pulmonary function laboratories.
- Published
- 1999
21. Emphysema in silica- and asbestos-exposed workers seeking compensation. A CT scan study
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R, Bégin, R, Filion, and G, Ostiguy
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Male ,Analysis of Variance ,Time Factors ,Silicosis ,Smoking ,Middle Aged ,Respiratory Function Tests ,Pulmonary Emphysema ,Case-Control Studies ,Occupational Exposure ,Asbestosis ,Prevalence ,Humans ,Regression Analysis ,Workers' Compensation ,Tomography, X-Ray Computed - Abstract
It has been established that coal pneumoconiosis and confluent silicosis are associated with emphysematous changes in the lungs. In the present study, we addressed the concept of emphysema in simple silicosis and asbestosis and in workers exposed to these minerals without the pneumoconiosis. The study was done on 207 consecutive workers evaluated for possible pneumoconiosis at Québec Workman Compensation Board, who had a radiographic reading of pneumoconiosis in the category 0 or 1 of the ILO scale, and in 5 control subjects. Emphysema was detected, typed, and graded on high-resolution CT scans by three independent experienced readers. Age, work experience and industry, smoking habits, and pulmonary function test results were analyzed for possible associations. The subjects were 59 +/- 1 years of age and had mineral dust exposure averaging 26 +/- 1 years; 31 were lifetime nonsmokers and the others were either ex- or current smokers. Ninety-six workers were from primary and 111 from secondary industries and did not differ in any parameter. The CT scan readings for emphysema yielded a 63% complete agreement. In lifetime non-smokers, emphysema was seen in 1 of 20 subjects without pneumoconiosis but in 8 of 11 patients with pneumoconioses. In smokers without pneumoconioses, emphysema was present in 55% of patients with silica exposure, but 29% of patients with asbestos exposure but comparable smoking (p = 0.04). Emphysema type was equally distributed among the groups except for more paracicatricial type in confluent silicosis. Regression analyses documented that age, smoking, exposure type, and presence of pneumoconiosis were significant contribution factors. In the workers without pneumoconiosis, age, smoking, and exposure type (silica) were significant. Emphysema related best with FEV1/FVC ratio, MMEF, and DCO reductions. The prevalence of abnormality of FEV1/FVC ratio was two to five times normal and that of reduced DCO two times normal. We conclude that, in our population, there was a significant excess of CT scan emphysema, associated with lung dysfunction, in those with pneumoconioses and in smokers with silica exposure. In the absence of smoking, it took a patient with pneumoconiosis to have emphysema. These changes contributed to the lung function impairment of these subjects with ILO category 0 or 1 pneumoconioses.
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- 1995
22. [Focus on smoking]
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M, Gagné, A, Gervais, M, Juneau, R, Laforte, C, Lemoine, G, Ostiguy, D, Perreault, M, Robitaille, J, Taillefer, and M, Xhignesse
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Male ,Nicotine ,Physician-Patient Relations ,Heart Diseases ,Socioeconomic Factors ,Smoking ,Humans ,Female ,Smoking Cessation ,Smoking Prevention ,Tobacco Smoke Pollution ,Administration, Cutaneous - Published
- 1994
23. Computed tomography in the early detection of asbestosis
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G Ostiguy, R Filion, N Colman, Raymond Bégin, and P Bertrand
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Thorax ,Adult ,medicine.medical_specialty ,Radiography ,Asbestosis ,Vital Capacity ,Occupational disease ,Forced Expiratory Volume ,Occupational Exposure ,medicine ,Humans ,Aged ,Lung ,medicine.diagnostic_test ,business.industry ,Pneumoconiosis ,Public Health, Environmental and Occupational Health ,Asbestos ,respiratory system ,Middle Aged ,medicine.disease ,respiratory tract diseases ,Respiratory Function Tests ,medicine.anatomical_structure ,Radiography, Thoracic ,Tomography ,Radiology ,business ,Nuclear medicine ,Chest radiograph ,Tomography, X-Ray Computed ,Research Article - Abstract
Computed tomography (CT; both conventional (CCT) and high resolution (HRCT)) scans of the thorax were evaluated to detect early asbestosis in 61 subjects exposed to asbestos dust in Quebec for an average of 22(3) years and in five controls. The study was limited to consecutive cases with chest radiographs of the International Labour Organisation categories 0 or 1 determined independently. All subjects had a standard high kilovoltage posteroanterior and lateral chest radiograph, a set of 10-15 1 cm collimation CCT scans and a set of three to five 2 mm collimation HRCT scans in the upper, middle, and lower lung fields. Five experienced readers independently read each chest radiograph and sets of CT scans. On the basis of three to five readers agreeing for small opacities of the lung parenchyma, 12/46 (26%) negative chest radiographs were positive on CT scans, but 6/18 (33%) positive chest radiographs were negative on CT scan. On the basis of four to five readers agreeing on a chest radiograph, 36/66 (54%) subjects were normal (group A), 17/66 (26%) were indeterminate (group B), and 13/66 (20%) were abnormal (group C). By the combined readings of CCT and HRCT, 4/31 (13%) asbestos exposed subjects of group A were abnormal (p < 0.001), 6/17 (35%) of group B were abnormal, and in group C, 1/13 (8%) was normal, 2/13 were indeterminate, and 10/13 (77%) were abnormal. Separate readings of CCT and HRCT on distinct films in 14 subjects showed that all cases of asbestosis were abnormal on both CCT and HRCT. Inter-reader analyses by kappa statistics showed significantly better agreement for the readings of CT than the chest radiographs (p < 0.001), and for the reading of CCT than HRCT (p < 0.01). Thus CT scans of the thorax identifies significantly more irregular opacities consistent with the diagnosis of asbestosis than the chest radiograph (20 cases on CT scans v 13 on chest radiographs when four to five readers agreed, 13% of asbestos exposed subjects with normal chest radiographs or 21% of asbestos exposed subjects with normal or near normal chest radiographs. It decreased the number of indeterminate cases significantly from 17 on chest radiographs to 13 on CT scans. All cases of asbestosis detected only on CT scans were similarly seen on CCT and HRCT and did not have significant changes in lung function. The CT scans significantly reduced the inter-reader variability, despite the absence of ILO type reference films for these scans.
- Published
- 1993
24. Computed tomographic scanning of the thorax in workers at risk of or with silicosis
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R, Bégin, G, Ostiguy, S, Groleau, and R, Filion
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Diagnosis, Differential ,Radiographic Image Enhancement ,Occupational Medicine ,Lung Neoplasms ,Silicosis ,Quebec ,Humans ,Quartz ,Tomography, X-Ray Computed ,Lung ,Silicotuberculosis - Published
- 1990
25. Recurrent localised pneumonia due to bronchial infiltration in a patient with chronic lymphocytic leukaemia
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G Ostiguy, S Cousineau, M Gyger, and A Desjardins
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Pulmonary and Respiratory Medicine ,Pathology ,medicine.medical_specialty ,Right middle lobe ,Bronchi ,Middle lobe bronchus ,Bronchoscopy ,Recurrence ,medicine ,Humans ,Lung ,Lymphocytic leukaemia ,Leukaemic infiltration ,medicine.diagnostic_test ,business.industry ,Bronchial Neoplasms ,Pneumonia ,Middle Aged ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,respiratory tract diseases ,medicine.anatomical_structure ,Female ,business ,Infiltration (medical) ,Research Article - Abstract
A woman with chronic lymphocytic leukaemia developed pneumonia on five occasions in the right middle lobe in the course of 27 months. Bronchoscopy disclosed concentric narrowing of the middle lobe bronchus by leukaemic infiltration.
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- 1990
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26. Lung function in silica-exposed workers. A relationship to disease severity assessed by CT scan
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R, Bégin, G, Ostiguy, A, Cantin, and D, Bergeron
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Pulmonary Gas Exchange ,Silicosis ,Humans ,Pulmonary Diffusing Capacity ,Middle Aged ,Lung Volume Measurements ,Tomography, X-Ray Computed ,Lung ,Maximal Expiratory Flow Rate ,Respiratory Function Tests - Abstract
To investigate the relationship of lung function, airflow limitation, and lung injury in silica-exposed workers, we analyzed the clinical, functional, and radiologic data of 94 long-term workers exposed in the granite industry or in foundries. The subjects were divided into four subsets based on chest roentgenogram and CT scan of the thorax: group 1 consisted of 21 subjects with category 0 chest roentgenogram and category 0 CT scan; group 2, 28 subjects with category E 1 on both chest roentgenogram and CT scan; group 3, 18 subjects with category E 1 on chest roentgenogram but with coalescence or conglomeration or both seen only on CT scan; and group 4, 27 subjects with category E 1 and coalescence or conglomeration or both on roentgenogram and CT scan. The groups did not differ in terms of age, height, cigarette smoking, or years of exposure. Lung volumes were significantly reduced only in group 4 (p less than 0.05). Lung compliance, diffusion capacity, and the rest-exercise P(A-a)O2 gradient were reduced in groups 3 and 4 (p less than 0.05). Expiratory flow rates were significantly reduced in groups 2, 3, and 4, with the lowest values in group 4. The expiratory flow rates in group 3 were significantly lower in group 3 than in group 2. These results support the concept that airflow in silica-exposed workers is significantly reduced when the disease is detectable on simple chest roentgenogram; coalescence or conglomeration or both on chest roentgenogram or CT scan is associated with significant loss of lung volumes, gas exchange function, and increased airflow obstruction.
- Published
- 1988
27. [Discussion on respiratory physiology]
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H, Frank, G, Ostiguy, and D, Massey
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Respiratory Tract Diseases ,Respiratory Physiological Phenomena ,Humans - Published
- 1968
28. [Gas exchange]
- Author
-
G, Ostiguy
- Subjects
Pulmonary Alveoli ,Carbon Monoxide ,Respiration ,Humans - Published
- 1968
29. Abnormal 99mTc brain scan in cerebral sarcoidosis
- Author
-
B, Vitye, G, Ostiguy, and E, LeBel
- Subjects
Diagnosis, Differential ,Brain Diseases ,Sarcoidosis ,Humans ,Technetium ,Female ,Middle Aged ,Radionuclide Imaging ,Research Article - Published
- 1969
30. [Transthoracic needle biopsy. Value in the diagnosis of neoplasms]
- Author
-
P, Bolduc, Y, Boivin, G, Ostiguy, and P, Nadeau
- Subjects
Adult ,Male ,Lung Neoplasms ,Biopsy ,Methods ,Humans ,Female ,Middle Aged ,Aged - Published
- 1969
31. [Blood cortisol in neoplasm cases]
- Author
-
W, Lewis, P, Nadeau, J, Fauteux, G, Ostiguy, P, Leblanc, and M, Chrétien
- Subjects
Adult ,Male ,Lung Neoplasms ,Hydrocortisone ,Adrenal Gland Neoplasms ,Adenocarcinoma ,Middle Aged ,Pancreatic Neoplasms ,Carcinoma, Bronchogenic ,Adrenocorticotropic Hormone ,Neoplasms ,Carcinoma, Squamous Cell ,Humans ,Female ,Neoplasm Metastasis ,Aged - Published
- 1971
32. Impact of electromagnetic fields on human vestibular system and standing balance: pilot results and future developments.
- Author
-
A Allen, S Villard, M Corbacio, D Goulet, M Plante, M Souques, F Deschamps, G Ostiguy, J Lambrozo, A W Thomas, and A Legros
- Published
- 2016
- Full Text
- View/download PDF
33. An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease.
- Author
-
Balmes JR, Abraham JL, Dweik RA, Fireman E, Fontenot AP, Maier LA, Muller-Quernheim J, Ostiguy G, Pepper LD, Saltini C, Schuler CR, Takaro TK, and Wambach PF
- Subjects
- Berylliosis etiology, Chronic Disease, Humans, Hypersensitivity etiology, Berylliosis diagnosis, Berylliosis therapy, Beryllium toxicity, Hypersensitivity diagnosis, Hypersensitivity therapy, Occupational Exposure adverse effects
- Abstract
Rationale: Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD)., Objectives: The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD., Methods: Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management., Main Results: The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP β chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline., Conclusions: Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.
- Published
- 2014
- Full Text
- View/download PDF
34. Smart meters and routers radiofrequency disturbances study with pacemakers and implantable cardiac defibrillators.
- Author
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Ostiguy G, Black T, Bluteau LJ, Dupont L, Dyrda K, Girard G, Nguyen DH, Plante M, and Thibault B
- Subjects
- Electricity, Equipment Failure Analysis methods, Quebec, Artifacts, Computer Communication Networks instrumentation, Defibrillators, Implantable, Electric Power Supplies, Equipment Failure, Pacemaker, Artificial, Wireless Technology instrumentation
- Abstract
Background: There is no scientific literature that examines radiofrequency (RF) interference from Smart Meters with cardiac implantable electronic devices (CIEDs). The objective of this in vitro study was to assess any potential interference with Medtronic CIEDs (Medtronic Inc., Minneapolis, MN, USA)., Methods: In the Quebec testing, five models of Medtronic CIEDs were placed in an acrylic cylinder filled with a saline solution and faced a Landis+Gyr Smart Meter or Router (Landis+Gyr AG, Zug, Switzerland). The distance between CIEDs and the meter casing or router antenna was 10 cm. The Meter's normal operating conditions were modified to artificially set the number of impulsions at an abnormally high level (one, two, and three impulses per second). Each scenario was repeated one to five times, for 1 minute each. In the U.S. testing, 6 cm and 15 cm (∼2.25' and ∼6') separated the six models of Medtronic CIEDs from the Schlumberger Smart Meter (Itron Inc., Liberty Lake, WA, USA), which generally sent out a 96-bit Standard Consumption Message over 3 seconds. The transmission varied in frequencies along with the interval between cycles., Results: A total of 6,966 RF transmissions were completed during the 34 tests conducted in Quebec. In the United States, the CIED was exposed to the meter for 10 minutes to provide a minimum of 200 completed RF transmissions. No interference was observed in worst-case scenarios (testing of meters and CIEDs at their performance limits)., Conclusions: Landis+Gyr Smart Meters/Routers and Schlumberger Smart Meters do not interfere with the functioning of the Medtronic CIEDs tested, when placed, respectively, 10 cm and 6 cm and 15 cm apart., (©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.)
- Published
- 2013
- Full Text
- View/download PDF
35. Resolving moral distress when caring for patients who smoke while using home oxygen therapy.
- Author
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Kayser JW, Nault D, and Ostiguy G
- Subjects
- Attitude of Health Personnel, Burns etiology, Female, Humans, Male, Nurse's Role psychology, Nurse-Patient Relations, Patient Education as Topic methods, Quebec, Risk-Taking, Smoking Cessation, Stress, Psychological, Burns prevention & control, Home Care Services organization & administration, Moral Obligations, Oxygen Inhalation Therapy nursing, Smoking adverse effects
- Abstract
More than 1 million people in the United States use home oxygen therapy and its demand is growing. However, there are dangers associated with its use, such as burns and home fires, and smoking is the most common cause of these incidents. As a result, home healthcare nurses feel intense emotional distress when caring for patients who smoke while using home oxygen therapy. This distress arises from the nurse's competing sense of moral duties toward these patients. The purpose of this article is to describe this distress, then to propose a 3-step process of taking concrete actions to resolve the distress.
- Published
- 2012
- Full Text
- View/download PDF
36. Pleural mesothelioma surveillance: validity of cases from a tumour registry.
- Author
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Labrèche F, Case BW, Ostiguy G, Chalaoui J, Camus M, and Siemiatycki J
- Subjects
- Aged, Asbestos adverse effects, Female, Humans, Incidence, Male, Mesothelioma chemically induced, Middle Aged, Occupational Diseases chemically induced, Occupational Diseases epidemiology, Occupational Exposure adverse effects, Pleural Neoplasms chemically induced, Quebec epidemiology, Mesothelioma epidemiology, Pleural Neoplasms epidemiology, Registries, Sentinel Surveillance
- Abstract
Background: Pleural mesothelioma is a rare tumour associated with exposure to asbestos fibres. Fewer than than one-quarter of cases registered in the Quebec Tumour Registry (QTR) have been compensated as work-related. While establishing a surveillance system, this led to questioning as to whether there has been over-registration of cases that are not authentic pleural mesotheliomas in the QTR., Objective: To assess whether registered cases of pleural mesothelioma could be confirmed., Methods: A medical chart review was designed to assess the proportion of mesothelioma cases newly registered in the QTR in 2001⁄2002 that could be confirmed. For each registered case, clinical, medical imaging and pathology information were sought and, occasionally, additional immunohistochemistry staining was obtained. Three specialists - a chest physician, a radiologist and a pathologist - reviewed the available information and material, coding each mesothelioma case as to degree of certainty of the mesothelioma diagnosis., Results: The QTR reported 190 incident cases of mesothelioma (81% males) for the period. The specialists classified 81% of charts as 'certain⁄probable' or 'possible' mesotheliomas, 8% as 'unlikely to be a mesothelioma' and 11% as 'not a mesothelioma'. After excluding chart summaries of unsatisfactory quality, 87% to 88% of the charts were classified as 'certain⁄probable' or 'possible' mesotheliomas, and 9% to 11% were still considered 'not a mesothelioma'., Conclusion: Tumour registry data are a valid source of information for mesothelioma surveillance. While there is some over-registration of mesothelioma cases in the QTR, a significant majority of registered cases appeared to be authentic. Over-registration cannot explain the greater proportion of cases that were not compensated.
- Published
- 2012
- Full Text
- View/download PDF
37. Point-of-care urine tests for smoking status and isoniazid treatment monitoring in adult patients.
- Author
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Nicolau I, Tian L, Menzies D, Ostiguy G, and Pai M
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Antitubercular Agents therapeutic use, Female, Humans, Isoniazid therapeutic use, Latent Tuberculosis drug therapy, Male, Medication Adherence, Middle Aged, Multivariate Analysis, Reference Standards, Regression Analysis, Reproducibility of Results, Sensitivity and Specificity, Urinalysis standards, Young Adult, Antitubercular Agents urine, Cotinine urine, Isoniazid urine, Latent Tuberculosis urine, Point-of-Care Systems, Smoking urine, Urinalysis methods
- Abstract
Background: Poor adherence to isoniazid (INH) preventive therapy (IPT) is an impediment to effective control of latent tuberculosis (TB) infection. TB patients who smoke are at higher risk of latent TB infection, active disease, and TB mortality, and may have lower adherence to their TB medications. The objective of our study was to validate IsoScreen and SmokeScreen (GFC Diagnostics, UK), two point-of-care tests for monitoring INH intake and determining smoking status. The tests could be used together in the same individual to help identify patients with a high-risk profile and provide a tailored treatment plan that includes medication management, adherence interventions, and smoking cessation programs., Methodology/principal Findings: 200 adult outpatients attending the TB and/or the smoking cessation clinic were recruited at the Montreal Chest Institute. Sensitivity and specificity were measured for each test against the corresponding composite reference standard. Test reliability was measured using kappa statistic for intra-rater and inter-rater agreement. Univariate and multivariate logistic regression models were used to explore possible covariates that might be related to false-positive and false-negative test results. IsoScreen had a sensitivity of 93.2% (95% confidence interval [CI] 80.3, 98.2) and specificity of 98.7% (94.8, 99.8). IsoScreen had intra-rater agreement (kappa) of 0.75 (0.48, 0.94) and inter-rater agreement of 0.61 (0.27, 0.90). SmokeScreen had a sensitivity of 69.2% (56.4, 79.8), specificity of 81.6% (73.0, 88.0), intra-rater agreement of 0.77 (0.56, 0.94), and inter-rater agreement of 0.66 (0.42, 0.88). False-positive SmokeScreen tests were strongly associated with INH treatment., Conclusions: IsoScreen had high validity and reliability, whereas SmokeScreen had modest validity and reliability. SmokeScreen tests did not perform well in a population receiving INH due to the association between INH treatment and false-positive SmokeScreen test results. Development of the next generation SmokeScreen assay should account for this potential interference.
- Published
- 2012
- Full Text
- View/download PDF
38. Proposed criteria for mixed-dust pneumoconiosis: definition, descriptions, and guidelines for pathologic diagnosis and clinical correlation.
- Author
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Honma K, Abraham JL, Chiyotani K, De Vuyst P, Dumortier P, Gibbs AR, Green FH, Hosoda Y, Iwai K, Williams WJ, Kohyama N, Ostiguy G, Roggli VL, Shida H, Taguchi O, and Vallyathan V
- Subjects
- Humans, International Cooperation, Occupational Exposure adverse effects, Pneumoconiosis classification, Pneumoconiosis etiology, Silicon Dioxide adverse effects, Dust, Lung pathology, Minerals, Pneumoconiosis pathology, Practice Guidelines as Topic
- Abstract
We defined mixed-dust pneumoconiosis (MDP) pathologically as a pneumoconiosis showing dust macules or mixed-dust fibrotic nodules (MDF), with or without silicotic nodules (SN), in an individual with a history of exposure to mixed dust. We defined the latter arbitrarily as a mixture of crystalline silica and nonfibrous silicates. According to our definition of MDP, therefore, MDF should outnumber SN in the lung to make a pathologic diagnosis of MDP. In the absence of confirmation of exposure, mineralogic analyses can be used to support the pathologic diagnosis. The clinical diagnosis of MDP requires the exclusion of other well-defined pneumoconioses, including asbestosis, coal workers' pneumoconiosis, silicosis, hematite miners' pneumoconiosis, welders' pneumoconiosis, berylliosis, hard metal disease, silicate pneumoconiosis, diatomaceous earth pneumoconiosis, carborundum pneumoconiosis, and corundum pneumoconiosis. Typical occupations associated with the diagnosis of MDP include metal miners, quarry workers, foundry workers, pottery and ceramics workers, and stonemasons. Irregular opacities are the major radiographic findings in MDP (ILO 1980), in contrast to silicosis, in which small rounded opacities predominate. Clinical symptoms of MDP are nonspecific. MDP must be distinguished from a variety of nonoccupational interstitial pulmonary disorders.
- Published
- 2004
- Full Text
- View/download PDF
39. [Quebec spirometry reference values].
- Author
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Martin RR, Ghezzo H, Amyot R, Bégin R, Desmeules M, Gauthier JJ, Malo JL, and Ostiguy G
- Subjects
- Adult, Aged, Female, Forced Expiratory Flow Rates, Humans, Male, Middle Aged, Quebec, Reference Values, Respiratory Tract Diseases diagnosis, Spirometry statistics & numerical data
- Abstract
Lung volumes forced expiratory flow rates and carbon monoxide diffusing capacity (apnea) were measured in 397 non-smoking, nonatopic, asymptomatic subjects (219 women, 178 men). The equipments and methods for measurements met the ATS criteria. The linear regression of the different variables according to age and height allowed the elaboration of a new set of predictive equations (Quebec). When comparing the different reference values used in North America and Europe, it is found that those of Miller and associates as well as those recommended by the CECA provide the best description of the Quebec situation. However, we would eventually prefer the reference values of Miller and associates over those of the CECA, because they better fit the current ATS criteria and also provide references for smokers. Lung volumes and forced expiratory flow rates of 97 non-smoking, nonatopic, asymptomatic manual workers were measured in the same conditions and submitted to the same comparisons. Quebec predictive values as well as those of Miller and associates isolated the same individuals in the so called abnormal zone. We therefore conclude that Quebec's standards should be preferred in the Province of Quebec pulmonary function laboratories.
- Published
- 1998
40. Emphysema in silica- and asbestos-exposed workers seeking compensation. A CT scan study.
- Author
-
Bégin R, Filion R, and Ostiguy G
- Subjects
- Analysis of Variance, Asbestosis epidemiology, Case-Control Studies, Humans, Male, Middle Aged, Occupational Exposure adverse effects, Prevalence, Pulmonary Emphysema diagnostic imaging, Pulmonary Emphysema epidemiology, Regression Analysis, Respiratory Function Tests, Silicosis epidemiology, Smoking epidemiology, Time Factors, Tomography, X-Ray Computed, Workers' Compensation, Asbestosis complications, Pulmonary Emphysema etiology, Silicosis complications
- Abstract
It has been established that coal pneumoconiosis and confluent silicosis are associated with emphysematous changes in the lungs. In the present study, we addressed the concept of emphysema in simple silicosis and asbestosis and in workers exposed to these minerals without the pneumoconiosis. The study was done on 207 consecutive workers evaluated for possible pneumoconiosis at Québec Workman Compensation Board, who had a radiographic reading of pneumoconiosis in the category 0 or 1 of the ILO scale, and in 5 control subjects. Emphysema was detected, typed, and graded on high-resolution CT scans by three independent experienced readers. Age, work experience and industry, smoking habits, and pulmonary function test results were analyzed for possible associations. The subjects were 59 +/- 1 years of age and had mineral dust exposure averaging 26 +/- 1 years; 31 were lifetime nonsmokers and the others were either ex- or current smokers. Ninety-six workers were from primary and 111 from secondary industries and did not differ in any parameter. The CT scan readings for emphysema yielded a 63% complete agreement. In lifetime non-smokers, emphysema was seen in 1 of 20 subjects without pneumoconiosis but in 8 of 11 patients with pneumoconioses. In smokers without pneumoconioses, emphysema was present in 55% of patients with silica exposure, but 29% of patients with asbestos exposure but comparable smoking (p = 0.04). Emphysema type was equally distributed among the groups except for more paracicatricial type in confluent silicosis. Regression analyses documented that age, smoking, exposure type, and presence of pneumoconiosis were significant contribution factors. In the workers without pneumoconiosis, age, smoking, and exposure type (silica) were significant. Emphysema related best with FEV1/FVC ratio, MMEF, and DCO reductions. The prevalence of abnormality of FEV1/FVC ratio was two to five times normal and that of reduced DCO two times normal. We conclude that, in our population, there was a significant excess of CT scan emphysema, associated with lung dysfunction, in those with pneumoconioses and in smokers with silica exposure. In the absence of smoking, it took a patient with pneumoconiosis to have emphysema. These changes contributed to the lung function impairment of these subjects with ILO category 0 or 1 pneumoconioses.
- Published
- 1995
- Full Text
- View/download PDF
41. Respiratory health of workers exposed to metal dusts and foundry fumes in a copper refinery.
- Author
-
Ostiguy G, Vaillancourt C, and Bégin R
- Subjects
- Adult, Aged, Analysis of Variance, Copper adverse effects, Cross-Sectional Studies, Female, Gases adverse effects, Humans, Longitudinal Studies, Lung Diseases, Interstitial etiology, Male, Middle Aged, Smoking adverse effects, Dust adverse effects, Lung Diseases, Obstructive etiology, Metallurgy, Occupational Diseases etiology, Pleural Diseases etiology
- Abstract
Objectives: To assess airflow limitation in workers exposed long term to metal dust, the prevalence of pleural plaques in those workers exposed in the past to asbestos, the influence of pleural plaques on lung function, and the possible association with airway disease caused by asbestos., Methods: A cross sectional and longitudinal (seven year) survey of 494 long term (mean (SEM) 21(1) years) workers in a copper refinery was carried out from medical questionnaires, chest radiographs, and forced spirometry., Results: The prevalence of lifetime non-smokers was 19%, current smokers 39%, and ex-smokers 42%. The prevalence of chronic obstructive pulmonary diseases (COPD) (forced expiratory volume in one second (FEV1) < 80% predicted) was 5%, small airway dysfunction (SAD) (maximal mid-expiratory flow (MMEF) < 60% predicted) was 7%, and this did not differ from the control population. The COPD and SAD were associated with cumulative smoking index but not with the cumulative work years at the plant or with any type of work at the plant. The mean (SEM) reduction of FEV1 was 20(7) ml in non-smokers, 26(4) ml in smokers, and 26(5) ml in ex-smokers (P > 0.05). In the smokers and ex-smokers with COPD, the loss of FEV1 was 53(10) (P < 0.02). The prevalence of pleural plaques was 11% (P < 0.0001); pleural plaques were found in older workers with known exposure to asbestos. The pleural plaques were circumscribed and associated with a non-significant 196 ml reduction in forced vital capacity (FVC) and non-significant reduction of FVC over time. The pleural plaques were not associated with COPD or SAD. The cumulative smoking index obtained by a technician did not differ from that by a chest physician., Conclusions: Despite exposures to asbestos that produced pleural plaques and exposures to metal dusts and foundry fumes the long term workers of this plant did not have excessive prevalence of COPD or SAD. The data suggest that low level long term exposure to metal dusts, gases, and foundry fumes do not necessarily cause respiratory dysfunction, circumscribed pleural plaques with low grades of width and extent do not reduce FVC significantly, and exposure to asbestos dust that produced pleural plaques does not necessarily produce airway dysfunction.
- Published
- 1995
- Full Text
- View/download PDF
42. [Focus on smoking].
- Author
-
Gagné M, Gervais A, Juneau M, Laforte R, Lemoine C, Ostiguy G, Perreault D, Robitaille M, Taillefer J, and Xhignesse M
- Subjects
- Administration, Cutaneous, Female, Heart Diseases etiology, Humans, Male, Nicotine administration & dosage, Nicotine poisoning, Physician-Patient Relations, Smoking Cessation methods, Smoking Prevention, Socioeconomic Factors, Tobacco Smoke Pollution, Smoking adverse effects, Smoking psychology
- Published
- 1994
43. Computed tomography in the early detection of asbestosis.
- Author
-
Bégin R, Ostiguy G, Filion R, Colman N, and Bertrand P
- Subjects
- Adult, Aged, Asbestos adverse effects, Asbestosis physiopathology, Forced Expiratory Volume, Humans, Middle Aged, Radiography, Thoracic, Respiratory Function Tests, Vital Capacity, Asbestosis diagnostic imaging, Occupational Exposure, Tomography, X-Ray Computed methods
- Abstract
Computed tomography (CT; both conventional (CCT) and high resolution (HRCT)) scans of the thorax were evaluated to detect early asbestosis in 61 subjects exposed to asbestos dust in Québec for an average of 22(3) years and in five controls. The study was limited to consecutive cases with chest radiographs of the International Labour Organisation categories 0 or 1 determined independently. All subjects had a standard high kilovoltage posteroanterior and lateral chest radiograph, a set of 10-15 1 cm collimation CCT scans and a set of three to five 2 mm collimation HRCT scans in the upper, middle, and lower lung fields. Five experienced readers independently read each chest radiograph and sets of CT scans. On the basis of three to five readers agreeing for small opacities of the lung parenchyma, 12/46 (26%) negative chest radiographs were positive on CT scans, but 6/18 (33%) positive chest radiographs were negative on CT scan. On the basis of four to five readers agreeing on a chest radiograph, 36/66 (54%) subjects were normal (group A), 17/66 (26%) were indeterminate (group B), and 13/66 (20%) were abnormal (group C). By the combined readings of CCT and HRCT, 4/31 (13%) asbestos exposed subjects of group A were abnormal (p < 0.001), 6/17 (35%) of group B were abnormal, and in group C, 1/13 (8%) was normal, 2/13 were indeterminate, and 10/13 (77%) were abnormal. Separate readings of CCT and HRCT on distinct films in 14 subjects showed that all cases of asbestosis were abnormal on both CCT and HRCT. Inter-reader analyses by kappa statistics showed significantly better agreement for the readings of CT than the chest radiographs (p < 0.001), and for the reading of CCT than HRCT (p < 0.01). Thus CT scans of the thorax identifies significantly more irregular opacities consistent with the diagnosis of asbestosis than the chest radiograph (20 cases on CT scans v 13 on chest radiographs when four to five readers agreed, 13% of asbestos exposed subjects with normal chest radiographs or 21% of asbestos exposed subjects with normal or near normal chest radiographs. It decreased the number of indeterminate cases significantly from 17 on chest radiographs to 13 on CT scans. All cases of asbestosis detected only on CT scans were similarly seen on CCT and HRCT and did not have significant changes in lung function. The CT scans significantly reduced the inter-reader variability, despite the absence of ILO type reference films for these scans.
- Published
- 1993
- Full Text
- View/download PDF
44. Recent advances in the early diagnosis of asbestosis.
- Author
-
Bégin R, Ostiguy G, Filion R, and Groleau S
- Subjects
- Asbestosis etiology, Humans, Lung diagnostic imaging, Lung pathology, Radionuclide Imaging, Respiratory Function Tests, Tomography, X-Ray Computed, Asbestos adverse effects, Asbestosis diagnosis
- Published
- 1992
- Full Text
- View/download PDF
45. Work-related mesothelioma in Québec, 1967-1990.
- Author
-
Bégin R, Gauthier JJ, Desmeules M, and Ostiguy G
- Subjects
- Adult, Aged, Aged, 80 and over, Asbestos adverse effects, Asbestos, Serpentine, Asbestosis mortality, Asbestosis pathology, Biopsy, Cross-Sectional Studies, Humans, Incidence, Male, Mesothelioma pathology, Middle Aged, Mining statistics & numerical data, Occupational Diseases pathology, Occupational Exposure adverse effects, Pleura pathology, Pleural Neoplasms pathology, Quebec epidemiology, Risk Factors, Mesothelioma epidemiology, Occupational Diseases epidemiology, Occupational Exposure statistics & numerical data, Pleural Neoplasms epidemiology
- Abstract
Prior surveys of malignant mesothelioma in Québec have noted that almost all the excess in occupational exposure related mesothelioma was in the manufacture and industrial application of asbestos rather than in the mining and milling operations. To evaluate the current status of malignant pleural mesothelioma in the Québec workforce, we reviewed all cases of pleural mesothelioma seen and accepted by the Québec Workman's Compensation Board (CSST) for work related compensation of industrial disease. We identified 120 cases, 7 of whom were females. They were of an average age of 59 +/- 8.5 yrs (sd) (range 42-84); they were exposed to asbestos dust in the workplace for an average of 26 +/- 14.3 yrs (range 0.5-50). The cases were subdivided into 3 groups according to workplace asbestos exposures. There were 49 cases originating in the mines and mills of the Québec Eastern Township region (primary industry, group 1), 50 cases from the manufacture and industrial application sector (secondary industry, group 2), and 21 cases from industries where asbestos was not a major work material, often an "incidental" material (tertiary industry, group 3). Group 1 was of an average age of 62 +/- 8 years, exposed to asbestos dust 31 +/- 14 years and the distribution of exposure time was as follows: 15% cases with < or = 10 year-exposure and 77% > or = 25 year-exposure. In group 2, the age was significantly lower at 57 +/- 9 years; the exposure time was also significantly lower at 22 +/- 14 years, and the distribution of exposure time differed from the above (29% cases with < or = 10 year-exposure and 48% > or = 25 year-exposure). In group 3, the average age was 58 +/- 7 years, the exposure time was also significantly lower at 28 +/- 12 years and the distribution of exposure time differed from the above (33% cases with < or = 10 year-exposure and 62% > or = 25 year-exposure). Analyses of the yearly incidence of new cases in each group documented the general incremental trend in all groups, with the sharpest rises in group 3. In the mining towns of Thetford and Asbestos, the incidence of mesothelioma was proportional to the workforce, thus suggesting that the tremolite air contamination, which is 7.5 x higher in Thetford, may not be a significant determinant of the disease in these workers.(ABSTRACT TRUNCATED AT 400 WORDS)
- Published
- 1992
- Full Text
- View/download PDF
46. Computed tomography scan in the early detection of silicosis.
- Author
-
Bégin R, Ostiguy G, Fillion R, and Colman N
- Subjects
- Adult, Aged, Humans, Lung diagnostic imaging, Middle Aged, Respiratory Function Tests, Silicosis diagnosis, Time Factors, Silicosis diagnostic imaging, Tomography, X-Ray Computed methods
- Abstract
We evaluated the ability of both the conventional and high resolution computed tomography (CCT and HRCT, respectively) scans of the thorax to detect early silicosis in subjects exposed to silica dust in the mines and foundries of Québec for an average of 29 +/- 2 yr. The study was limited to subjects with chest radiograph (CR) of the International Labor Organization (ILO) Categories 0 or 1 as determined independently a priori. All subjects had a standard high-kilovoltage posteroanterior and lateral CR, a set of 10 to 15 1 cm collimation CCT scans, and a set of three to five 2 mm collimation HRCT scans in the upper, middle, and lower lung fields. For each CR and sets of CT scans, readings were done independently by four experienced readers. For small opacities of the lung parenchyma on CR, 32 of the 51 subjects were normal (Group A), six were indeterminate (Group B), and 13 were abnormal (Group C). By the combined readings of HRCT and CCT, 13 of the subjects (40%) in Group A were abnormal (p less than 0.001); four of the subjects in Group B were abnormal, and in Group C, one subject was normal, one indeterminate, and 11 (84%) abnormal. For confluence of small opacities, 48 of the 51 subjects were negative (Group 0), and three were positive (Group 1) on the CR. By the CT scan, 42 of the 48 subjects in Group 0 were negative, and the three subjects in Group 1 were positive; thus the CT scan added six positive cases with confluence of small opacities (six of 48, 12.5%).(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1991
- Full Text
- View/download PDF
47. Computed tomographic scanning of the thorax in workers at risk of or with silicosis.
- Author
-
Bégin R, Ostiguy G, Groleau S, and Filion R
- Subjects
- Diagnosis, Differential, Humans, Lung Neoplasms diagnostic imaging, Quebec, Radiographic Image Enhancement methods, Silicosis etiology, Silicotuberculosis diagnostic imaging, Tomography, X-Ray Computed methods, Lung diagnostic imaging, Occupational Medicine methods, Quartz adverse effects, Silicosis diagnostic imaging
- Published
- 1990
48. Recurrent localised pneumonia due to bronchial infiltration in a patient with chronic lymphocytic leukaemia.
- Author
-
Desjardins A, Ostiguy G, Cousineau S, and Gyger M
- Subjects
- Bronchi pathology, Bronchial Neoplasms pathology, Female, Humans, Leukemia, Lymphocytic, Chronic, B-Cell pathology, Middle Aged, Pneumonia pathology, Recurrence, Bronchial Neoplasms complications, Leukemia, Lymphocytic, Chronic, B-Cell complications, Pneumonia etiology
- Abstract
A woman with chronic lymphocytic leukaemia developed pneumonia on five occasions in the right middle lobe in the course of 27 months. Bronchoscopy disclosed concentric narrowing of the middle lobe bronchus by leukaemic infiltration.
- Published
- 1990
- Full Text
- View/download PDF
49. Summary of the task force report on occupational respiratory disease.
- Author
-
Ostiguy G and Guenter CA
- Published
- 1980
50. Lung function in silica-exposed workers. A relationship to disease severity assessed by CT scan.
- Author
-
Bégin R, Ostiguy G, Cantin A, and Bergeron D
- Subjects
- Humans, Lung diagnostic imaging, Lung Volume Measurements, Maximal Expiratory Flow Rate, Middle Aged, Pulmonary Diffusing Capacity, Pulmonary Gas Exchange, Silicosis diagnostic imaging, Respiratory Function Tests, Silicosis physiopathology, Tomography, X-Ray Computed
- Abstract
To investigate the relationship of lung function, airflow limitation, and lung injury in silica-exposed workers, we analyzed the clinical, functional, and radiologic data of 94 long-term workers exposed in the granite industry or in foundries. The subjects were divided into four subsets based on chest roentgenogram and CT scan of the thorax: group 1 consisted of 21 subjects with category 0 chest roentgenogram and category 0 CT scan; group 2, 28 subjects with category E 1 on both chest roentgenogram and CT scan; group 3, 18 subjects with category E 1 on chest roentgenogram but with coalescence or conglomeration or both seen only on CT scan; and group 4, 27 subjects with category E 1 and coalescence or conglomeration or both on roentgenogram and CT scan. The groups did not differ in terms of age, height, cigarette smoking, or years of exposure. Lung volumes were significantly reduced only in group 4 (p less than 0.05). Lung compliance, diffusion capacity, and the rest-exercise P(A-a)O2 gradient were reduced in groups 3 and 4 (p less than 0.05). Expiratory flow rates were significantly reduced in groups 2, 3, and 4, with the lowest values in group 4. The expiratory flow rates in group 3 were significantly lower in group 3 than in group 2. These results support the concept that airflow in silica-exposed workers is significantly reduced when the disease is detectable on simple chest roentgenogram; coalescence or conglomeration or both on chest roentgenogram or CT scan is associated with significant loss of lung volumes, gas exchange function, and increased airflow obstruction.
- Published
- 1988
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