SCIREQ Scientific Respiratory Equipment Inc.

Montréal, Canada

SCIREQ Scientific Respiratory Equipment Inc.

Montréal, Canada

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Hartney J.M.,University of Colorado at Denver | Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc.
Methods in Molecular Biology | Year: 2013

This chapter provides an outline of the procedures necessary to measure airway hyperresponsiveness to inhaled methacholine in mouse models of allergic lung disease. We present a method for acquiring detailed measurements of respiratory mechanics using broadband low-frequency oscillatory waveforms applied at the subject's airway opening and analyzed using the constant phase model of the lung. We acknowledge that there are other methods of measuring airway responsiveness in allergic rodent models. However, a discussion of the merits and or detriments of these various methods have been vigorously debated in the primary literature and are beyond the scope of this chapter. The goal of this chapter is to provide a guide in how to begin these types of assays in laboratories which have little to no experience with these particular types of assessments. © 2013 Springer Science+Business Media, LLC.


Shalaby K.H.,McGill University | Gold L.G.,SCIREQ Scientific Respiratory Equipment Inc. | Schuessler T.F.,SCIREQ Scientific Respiratory Equipment Inc. | Martin J.G.,McGill University | Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc.
Respiratory Research | Year: 2010

Background: Pulmonary function has been reported in mice using negative pressure-driven forced expiratory manoeuvres (NPFE) and the forced oscillation technique (FOT). However, both techniques have always been studied using separate cohorts of animals or systems. The objective of this study was to obtain NPFE and FOT measurements at baseline and following bronchoconstriction from a single cohort of mice using a combined system in order to assess both techniques through a refined approach.Methods: Groups of allergen- or sham-challenged ovalbumin-sensitized mice that were either vehicle (saline) or drug (dexamethasone 1 mg/kg ip)-treated were studied. Surgically prepared animals were connected to an extended flexiVent system (SCIREQ Inc., Montreal, Canada) permitting NPFE and FOT measurements. Lung function was assessed concomitantly by both techniques at baseline and following doubling concentrations of aerosolized methacholine (MCh; 31.25 - 250 mg/ml). The effect of the NPFE manoeuvre on respiratory mechanics was also studied.Results: The expected exaggerated MCh airway response of allergic mice and its inhibition by dexamethasone were detected by both techniques. We observed significant changes in FOT parameters at either the highest (Ers, H) or the two highest (Rrs, RN, G) MCh concentrations. The flow-volume (F-V) curves obtained following NPFE manoeuvres demonstrated similar MCh concentration-dependent changes. A dexamethasone-sensitive decrease in the area under the flow-volume curve at the highest MCh concentration was observed in the allergic mice. Two of the four NPFE parameters calculated from the F-V curves, FEV0.1and FEF50, also captured the expected changes but only at the highest MCh concentration. Normalization to baseline improved the sensitivity of NPFE parameters at detecting the exaggerated MCh airway response of allergic mice but had minimal impact on FOT responses. Finally, the combination with FOT allowed us to demonstrate that NPFE induced persistent airway closure that was reversible by deep lung inflation.Conclusions: We conclude that FOT and NPFE can be concurrently assessed in the same cohort of animals to determine airway mechanics and expiratory flow limitation during methacholine responses, and that the combination of the two techniques offers a refined control and an improved reproducibility of the NPFE. © 2010 Shalaby et al; licensee BioMed Central Ltd.


McGovern T.K.,McGill University | Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc | Fereydoonzad L.,SCIREQ Scientific Respiratory Equipment Inc | Schuessler T.F.,SCIREQ Scientific Respiratory Equipment Inc | Martin J.G.,McGill University
Journal of Visualized Experiments | Year: 2013

The forced oscillation technique (FOT) is a powerful, integrative and translational tool permitting the experimental assessment of lung function in mice in a comprehensive, detailed, precise and reproducible manner. It provides measurements of respiratory system mechanics through the analysis of pressure and volume signals acquired in reaction to predefined, small amplitude, oscillatory airflow waveforms, which are typically applied at the subject's airway opening. The present protocol details the steps required to adequately execute forced oscillation measurements in mice using a computer-controlled piston ventilator (flexiVent; SCIREQ Inc, Montreal, Qc, Canada). The description is divided into four parts: preparatory steps, mechanical ventilation, lung function measurements, and data analysis. It also includes details of how to assess airway responsiveness to inhaled methacholine in anesthetized mice, a common application of this technique which also extends to other outcomes and various lung pathologies. Measurements obtained in naïve mice as well as from an oxidative-stress driven model of airway damage are presented to illustrate how this tool can contribute to a better characterization and understanding of studied physiological changes or disease models as well as to applications in new research areas. © JoVE 2006-2013. All Rights Reserved.


Kearley J.,MedImmune LLC | Erjefalt J.S.,Lund University | Andersson C.,Lund University | Benjamin E.,MedImmune LLC | And 13 more authors.
American Journal of Respiratory and Critical Care Medicine | Year: 2011

Rationale: IL-9 is a pleiotropic cytokine that has multiple effects on structural as well as numerous hematopoietic cells, which are central to the pathogenesis of asthma. Objectives: The contribution of IL-9 to asthma pathogenesis has thus far been unclear, due to conflicting reports in the literature. These earlier studies focused on the role of IL-9 in acute inflammatory models; here we have investigated the effects of IL-9 blockade during chronic allergic inflammation. Methods: Mice were exposed to either prolonged ovalbumin or house dust mite allergen challenge to induce chronic inflammation and airway remodeling. Measurements and Main Results: We found that IL-9 governs allergen-induced mast cell (MC) numbers in the lung and has pronounced effects on chronic allergic inflammation. Anti-IL-9 antibody-treated mice were protected from airway remodeling with a concomitant reduction in mature MC numbers and activation, in addition to decreased expression of the profibrotic mediators transforming growth factor-β1, vascular endothelial growth factor, and fibroblast growth factor-2 in the lung. Airway remodeling was associated with impaired lung function in the peripheral airways and this was reversed by IL-9 neutralization. In human asthmatic lung tissue, we identified MCs as the main IL-9 receptor expressing population and found them to be sources of vascular endothelial growth factor and fibroblast growth factor-2. Conclusions: Our data suggest an important role for an IL-9-MC axis in the pathology associated with chronic asthma and demonstrate that an impact on this axis could lead to a reduction in chronic inflammation and improved lung function in patients with asthma. Copyright © 2011 American Thoracic Society.


Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc. | Fereydoonzad L.,SCIREQ Scientific Respiratory Equipment Inc. | Schuessler T.F.,SCIREQ Scientific Respiratory Equipment Inc.
American journal of physiology. Lung cellular and molecular physiology | Year: 2015

Airway hyperresponsiveness often constitutes a primary outcome in respiratory studies in mice. The procedure commonly employs aerosolized challenges, and results are typically reported in terms of bronchoconstrictor concentrations loaded into the nebulizer. Yet, because protocols frequently differ across studies, especially in terms of aerosol generation and delivery, direct study comparisons are difficult. We hypothesized that protocol variations could lead to differences in aerosol delivery efficiency and, consequently, in the dose delivered to the subject, as well as in the response. Thirteen nebulization patterns containing common protocol variations (nebulization time, duty cycle, particle size spectrum, air humidity, and/or ventilation profile) and using increasing concentrations of methacholine and broadband forced oscillations (flexiVent, SCIREQ, Montreal, Qc, Canada) were created, characterized, and studied in anesthetized naïve A/J mice. A delivered dose estimate calculated from nebulizer-, ventilator-, and subject-specific characteristics was introduced and used to account for protocol variations. Results showed that nebulization protocol variations significantly affected the fraction of aerosol reaching the subject site and the delivered dose, as well as methacholine reactivity and sensitivity in mice. From the protocol variants studied, addition of a slow deep ventilation profile during nebulization was identified as a key factor for optimization of the technique. The study also highlighted sensitivity differences within the lung, as well as the possibility that airway responses could be selectively enhanced by adequate control of nebulizer and ventilator settings. Reporting results in terms of delivered doses represents an important standardizing element for assessment of airway hyperresponsiveness in mice. Copyright © 2015 the American Physiological Society.


Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc. | Fereydoonzad L.,SCIREQ Scientific Respiratory Equipment Inc. | Urovitch I.B.,SCIREQ Scientific Respiratory Equipment Inc. | Brunet J.-D.,SCIREQ Scientific Respiratory Equipment Inc.
Experimental Lung Research | Year: 2015

The sole commercial system currently employing the forced oscillation technique (FOT) in small laboratory animals (flexiVent; SCIREQ Inc., Canada) was recently redesigned along with its operating software. Yet, many users still work with the legacy version or a mixed configuration. This study aimed to compare result accuracy and precision between three flexiVent system configurations and to quantify the impact of configuration changes on measured parameters. Physiologically relevant resistance or elastance were measured at 2.5 Hz on the following three system configurations using characterized mechanical test loads: (i) legacy flexiVent-flexiVent v5.3.4 (Leg-fV5), (ii) legacy flexiVent-flexiWare v7.2.1 (Leg-fW7), and (iii) flexiVent FX-flexiWare v7.2.1 (FX-fW7). Results demonstrated measurements of high precision that were consistent between system configurations. There was no statistical difference between system configurations in terms of measuring a predicted resistance. Measurements of elastance, on the other hand, were configuration-sensitive with FX-fW7 generating values that were closer to theoretical ones than the other two configurations. The largest impact on measurement outcomes was associated with the most noteworthy configuration change (i.e., software and hardware replacement). This effect was however constrained, with variations in the order of 3-5%, approximately. In conclusion, the latest version of the sole commercial pre-clinical FOT system currently available generated results that were equivalent or better than those acquired with two other system configurations. Given that configuration changes were associated with subtle parameter differences, best practice would recommend consistency within a study and reporting the full details of the system used. © 2015 Informa Healthcare USA, Inc.


Bassett L.,CIToxLAB North America | Troncy E.,University of Montréal | Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc. | Schuessler T.F.,SCIREQ Scientific Respiratory Equipment Inc. | And 5 more authors.
Journal of Pharmacological and Toxicological Methods | Year: 2014

Introduction: A number of drugs in clinical trials are discontinued due to potentially life-threatening airway obstruction. As some drugs may not cause changes in core battery parameters such as tidal volume (Vt), respiratory rate (RR) or minute ventilation (MV), including measurements of respiratory mechanics in safety pharmacology studies represents an opportunity for design refinement. The present study aimed to test a novel non-invasive methodology to concomitantly measure respiratory system resistance (Rrs) and conventional respiratory parameters (Vt, RR, MV) in conscious Beagle dogs and cynomolgus monkeys. Methods: An Airwave Oscillometry system (tremoFlo; THORASYS Inc., Montreal, Canada) was used to concomitantly assess Rrs and conventional respiratory parameters before and after intravenous treatment with a bronchoactive agent. Respiratory mechanics measurements were performed by applying a short (i.e. 16s) single high frequency (19Hz) waveform at the subject's airway opening via a face mask. During measurements, pressure and flow signals were recorded. After collection of baseline measurements, methacholine was administered intravenously to Beagle dogs (n=6) and cynomolgus monkeys (n=4) at 8 and 68μg/kg, respectively. Results: In dogs, methacholine induced significant increases in Vt, RR and MV while in monkeys, it only augmented RR. A significant increase in Rrs was observed after methacholine administration in both species with mean percentage peak increases from baseline of 88 (53)% for dogs and 28 (16)% for cynomolgus monkeys. Conclusion: Airwave Oscillometry appears to be a promising non-invasive methodology to enable respiratory mechanics measurements in conscious large animals, a valuable refinement in respiratory safety pharmacology. © 2014 Elsevier Inc.


Robichaud A.,SCIREQ Scientific Respiratory Equipment Inc | Fereydoonzad L.,SCIREQ Scientific Respiratory Equipment Inc | Schuessler T.F.,SCIREQ Scientific Respiratory Equipment Inc
American Journal of Physiology - Lung Cellular and Molecular Physiology | Year: 2015

Airway hyperresponsiveness often constitutes a primary outcome in respiratory studies in mice. The procedure commonly employs aerosolized challenges, and results are typically reported in terms of bronchoconstrictor concentrations loaded into the nebulizer. Yet, because protocols frequently differ across studies, especially in terms of aerosol generation and delivery, direct study comparisons are difficult. We hypothesized that protocol variations could lead to differences in aerosol delivery efficiency and, consequently, in the dose delivered to the subject, as well as in the response. Thirteen nebulization patterns containing common protocol variations (nebulization time, duty cycle, particle size spectrum, air humidity, and/or ventilation profile) and using increasing concentrations of methacholine and broadband forced oscillations (flexiVent, SCIREQ, Montreal, Qc, Canada) were created, characterized, and studied in anesthetized naïve A/J mice. A delivered dose estimate calculated from nebulizer-, ventilator-, and subject-specific characteristics was introduced and used to account for protocol variations. Results showed that nebulization protocol variations significantly affected the fraction of aerosol reaching the subject site and the delivered dose, as well as methacholine reactivity and sensitivity in mice. From the protocol variants studied, addition of a slow deep ventilation profile during nebulization was identified as a key factor for optimization of the technique. The study also highlighted sensitivity differences within the lung, as well as the possibility that airway responses could be selectively enhanced by adequate control of nebulizer and ventilator settings. Reporting results in terms of delivered doses represents an important standardizing element for assessment of airway hyperresponsiveness in mice. © 2015, American Physiological Society. All rights reserved.


Patent
Scireq Scientific Respiratory Equipment Inc. | Date: 2010-11-03

The present invention relates to a lung function assessment system, a mechanical ventilator and method that allows simultaneously measurements of lung function and provides simultaneously mechanical ventilation to multiple subjects requiring one source of gas.


Patent
Scireq Scientific Respiratory Equipment Inc. | Date: 2010-03-15

A modular kit of complementary plethysmographic apparatus components including at least one tube, at least one termination device for closing an open extremity of the tube and first and second complementary coupling mechanisms formed on the tube and the termination device. The coupling mechanisms are adapted to provide sealing engagement between the tube and the termination device. The first and second complementary coupling mechanisms comprise a notched interface component adapted to fit into a corresponding mating gap component, such that a rotation of the two components with respect to each other, solidly locks the two components together while applying pressure onto a face seal between the two components.

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