Ce travail a été soutenu par Christopher et Dana Reeve Foundation (Grant CDRF OA2-0802-2), Kentucky moelle épinière et traumatisme crânien Research Trust (Grant 9-10A - KSCHIRT), Craig H. Fondation Neilsen (Grant 1000056824 - HN000PCG) et national Institutes of Health: National Heart Lung and Blood Institute (Grant 1R01HL103750-01A1).

1. Réglages <ol><li> têtes d&#39;électrodes de surface ont été placés sur les ventres musculaires de gauche (L) et droit (R) des muscles respiratoires: sternocléidomastoïdien (SC), scalene (S), trapèze supérieur sur la ligne médio-claviculaire (UT), la partie claviculaire du grand pectoral sur la ligne médio-claviculaire (P ), le diaphragme en ligne parasternal (D), intercostal au 6 ème espace intercostal sur la ligne axillaire antérieure (IC), abdomen rectus au niveau ombilical (RA), oblique abdomen sur la ligne axillaire (O), trapèze inférieur paraspinally au niveau midscapular (LT ), et paraspinal paraspinally sur iliaque intercrestal ligne (PS) 6. Les électrodes de masse ont été placées au cours des processus d&#39;acromion. Un laboratoire Système de mouvement Back Pack Unit, avec des électrodes fixées, était relié à un mouvement Laboratoire d&#39;EMG Desk Top appareil et du système Powerlab (Figure 1). </li><li> Circuit de surveillance de T-pièce pour enregistrer la pression des voies aériennes a été assemblé comme le montre la figure 2 et relié à la faible Pressure transducteur (MP45) en utilisant le tube d&#39;air. </li><li> MP45 a été connecté au CD15 et le système Powerlab (figure 1 et tableau 1). </li></ol> 2. Protocole MRAC <ol><li> Les tâches motrices respiratoires comprenaient des tâches maximum de pression inspiratoire (MIPT) et le Groupe de pression expiratoire maximum (MEPT). Pour effectuer MIPT ou MEPT, les sujets devaient produire effort inspiratoire maximum de volume résiduel ou efforts expiratoires de la capacité pulmonaire totale pendant 5 secondes à l&#39;aide d&#39;un circuit de surveillance T (figures 1 et 2). Chaque figure a été repéré par une longue tonalité 5 sec audible et répété 3x. Au moins 1 min de repos a été autorisée entre chaque effort. </li><li> Entrée EMG a été amplifié avec un gain de 2,000; filtré à 30-1,000 Hz et échantillonnée à 2.000 Hz. Entrée de pression des voies aériennes a été calibré à 100 cm d&#39;eau et échantillonné à 2.000 Hz. Les entrées de pression des voies aériennes EMG et ont été converties par le système d&#39;acquisition Powerlab utilisant 16 bits pleine échelle ADCrésolution. signaux pression des voies respiratoires, sEMG et marqueur ont été enregistrés simultanément 9. </li></ol> 3. Analyse des données <ol><li> Multi-musculaire activité de distribution fenêtres d&#39;analyse de 5 secondes chacun pour MIPT ou MEPT été déterminée à partir du marqueur d&#39;événement et de la pression des voies aériennes enregistrées avec le ton cuing qui a marqué le sujet quand commencer et terminer la tâche (Figure 3). L&#39;activité sEMG pour chaque muscle a été calculée en utilisant une racine carrée (RMS) 6,12 algorithme (Figure 4) signifier. Trois essais répétés pour chaque tâche ont été en moyenne de 13 pour chaque muscle (canal). </li><li> Les modèles d&#39;activation multi-musculaires ont été évalués sur la base d&#39;une méthode d&#39;analyse de vecteur connu comme l&#39;indice de réponse volontaire (VRI) 8 (figures 4-6) en utilisant le logiciel Matlab sur mesure (MathWorks). Pour chaque manœuvre, le calcul VRI produit deux valeurs, une ampleur et un indice de similarité (SI) (figures 5-6).Le paramètre Magnitude, le montant de l&#39;activité EMG combiné de tous les muscles dans la fenêtre de temps spécifique, a été calculé comme une longueur du vecteur de réponse (RV) pour tâche spécifique (figure 7). L&#39;indice de similarité (SI) fournit une valeur qui exprime le degré de similarité le RV de la SCI est soumise au vecteur de réponse de Prototype (PRV) provenant de sujets sains au cours de la même tâche. La valeur SI a été calculé pour chaque tâche en cosinus de l&#39;angle entre l&#39;objet VR et PRV SCI. La valeur SI varie entre 0 et 1,0, où la valeur de 1,0 représente la meilleure correspondance pour les vecteurs comparés 9 (figure 8). </li></ol>

<ol>
	<li>Schilero, G. J., Spungen, A. M., Bauman, W. A., Radulovic, M., Lesser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulmonary+function+and+spinal+cord+injury.">Pulmonary function and spinal cord injury.</a> Respir. Physiol. Neurobiol. 166, 129-141 (2009).</li><li>Winslow, C., Rozovsky, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+spinal+cord+injury+on+the+respiratory+system.">Effect of spinal cord injury on the respiratory system.</a> Am. J. Phys. Med. Rehabil. 82, 803-814 (2003).</li><li>Garshick, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+prospective+assessment+of+mortality+in+chronic+spinal+cord+injury.">A prospective assessment of mortality in chronic spinal cord injury.</a> Spinal Cord. 43, 408-416 (2005).</li><li>Jain, N. B., Brown, R., Tun, C. G., Gagnon, D., Garshick, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determinants+of+forced+expiratory+volume+in+1+second+(FEV1),+forced+vital+capacity+(FVC),+and+FEV1/FVC+in+chronic+spinal+cord+injury.">Determinants of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury.</a> Arch. Phys. Med. Rehabil. 87, 1327-1333 (2006).</li><li>Stolzmann, K. L., Gagnon, D. R., Brown, R., Tun, C. G., Garshick, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Longitudinal+change+in+FEV1+and+FVC+in+chronic+spinal+cord+injury.">Longitudinal change in FEV1 and FVC in chronic spinal cord injury.</a> Am. J. Respir. Crit. Care Med. 177, 781-786 (2008).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+Thoracic+Society/European+Respiratory+Society.+ATS/ERS+Statement+on+respiratory+muscle+testing.">American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing.</a> Am. J. Respir. Crit. Care Med. 166, 518-624 (2002).</li><li>Sherwood, A. M., McKay, W. B., Dimitrijevic, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Motor+control+after+spinal+cord+injury:+assessment+using+surface+EMG.">Motor control after spinal cord injury: assessment using surface EMG.</a> Muscle Nerve. 19, 966-979 (1996).</li><li>Lee, D. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+an+objective+interpretation+of+surface+EMG+patterns:+a+voluntary+response+index+(VRI).">Toward an objective interpretation of surface EMG patterns: a voluntary response index (VRI).</a> J. Electromyogr. Kinesiol. 14, 379-388 (2004).</li><li>Ovechkin, A., Vitaz, T., de Paleville, D. T., Aslan, S., McKay, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+respiratory+muscle+activation+in+individuals+with+chronic+spinal+cord+injury.">Evaluation of respiratory muscle activation in individuals with chronic spinal cord injury.</a> Respir. Physiol. Neurobiol. 173, 171-178 (2010).</li><li>Lim, H. K., Sherwood, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+of+surface+electromyographic+measurements+from+subjects+with+spinal+cord+injury+during+voluntary+motor+tasks.">Reliability of surface electromyographic measurements from subjects with spinal cord injury during voluntary motor tasks.</a> J. Rehabil. Res. Dev. 42, 413-422 (2005).</li><li>Lim, H. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurophysiological+assessment+of+lower-limb+voluntary+control+in+incomplete+spinal+cord+injury.">Neurophysiological assessment of lower-limb voluntary control in incomplete spinal cord injury.</a> Spinal Cord. 43, 283-290 (2005).</li><li>Sherwood, A. M., Graves, D. E., Priebe, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+motor+control+and+spasticity+after+spinal+cord+injury:+subjective+and+objective.">Altered motor control and spasticity after spinal cord injury: subjective and objective.</a> 37, 41-52 (2000).</li><li>McKay, W. B., Lim, H. K., Priebe, M. M., Stokic, D. S., Sherwood, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+neurophysiological+assessment+of+residual+motor+control+in+post-spinal+cord+injury+paralysis.">Clinical neurophysiological assessment of residual motor control in post-spinal cord injury paralysis.</a> Neurorehabil. Neural Repair. 18, 144-153 (2004).</li><li>Marino, R. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=International+standards+for+neurological+classification+of+spinal+cord+injury.">International standards for neurological classification of spinal cord injury.</a> J. Spinal. Cord. Med. 26, S50-S56 (2003).</li><li>American Spinal Injury Association and International Spinal Cord Society. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> International Standards for Neurological Classification of Spinal Cord Injury. , (2006).</li></ol>

Aucun conflit d&#39;intérêt à déclarer.

Essais cliniques standard pour évaluer la fonction motrice respiratoire après SCI et d&#39;autres troubles comprennent les tests de la fonction pulmonaire et la moelle échelle de dégradation de l&#39;Association américaine des blessures (AIS) évaluation 14,15. Toutefois, ces outils ne sont pas conçus pour l&#39;évaluation quantitative du tronc et le contrôle moteur respiratoires. Dans notre travail déjà publié 9, nous avons montré que le MRAC est une méthode valide pour évaluer quant...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the Device</td>
 <td>Vendor</td>
 <td>Product #</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>PowerLab System 16/35</td>
 <td>ADInstruments</td>
 <td>PL3516</td>
 <td>Number of units depends on number of channels recorded</td>
 </tr>
 <tr>
 <td>EMG System MA 300</td>
 <td>Motion Lab Systems</td>
 <td>MA300-XVI</td>
 <td>Number of units depends on number of channels recorded</td>
 </tr>
 <tr>
 <td>Low Pressure Transducer MP45</td>
 <td>Validyne</td>
 <td>MP45-40-871</td>
 <td></td>
 </tr>
 <tr>
 <td>Basic Carrier Demodulator CD15</td>
 <td>Validyne</td>
 <td>CD15-A-2-A-1</td>
 <td></td>
 </tr>
 <tr>
 <td>Air Pressure Manometer</td>
 <td>Boehringer</td>
 <td>4103</td>
 <td>Needed for MP45 calibration</td>
 </tr>
 <tr>
 <td>Event Marker</td>
 <td></td>
 <td></td>
 <td>Hand held switch that when pressed gives a DC voltage and sound output (including 5-sec long mark)</td>
 </tr>
 <tr>
 <td>Alcohol Wipes</td>
 <td>Henry Schein</td>
 <td>1173771</td>
 <td>Needed for electrodes placement</td>
 </tr>
 <tr>
 <td>Electrode Gel</td>
 <td>Lectron II</td>
 <td>36-3000-25</td>
 <td>Needed for electrodes placement</td>
 </tr>
 <tr>
 <td>Tagaderm</td>
 <td>Henry Schein</td>
 <td>7779152</td>
 <td>Needed for electrodes placement</td>
 </tr>
 <tr>
 <td>Noseclip </td>
 <td>Henry Schein</td>
 <td>1089460</td>
 <td></td>
 </tr>
 <tr>
 <td>T-piece Ventilator Monitoring Circuit with One-way Valves </td>
 <td>Alleglance (Airlife)</td>
 <td>1504</td>
 <td></td>
 </tr>
 <tr>
 <td>Air Tube </td>
 <td>UnoMedical</td>
 <td>400E</td>
 <td></td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>Table 1. List of specific equipment and supplies used for the Respiratory Motor Control Assessment.</td>
 </tr>
 </tbody>
 </table>

evaluation of respiratory muscle activation using respiratory motor control assessment (rmca) in individuals with chronic spinal cord injury

Pendant la respiration, l&#39;activation des muscles respiratoires est coordonné par l&#39;entrée intégrée du cerveau, le tronc cérébral et la moelle épinière. Lorsque cette coordination est perturbée par une blessure de la moelle épinière (SCI), le contrôle des muscles respiratoires innervés dessous du niveau de la blessure est compromise 1,2 conduisant à un dysfonctionnement des muscles respiratoires et des complications pulmonaires. Ces conditions sont parmi les principales causes de décès chez les patients atteints de SCI 3. Des tests de la fonction pulmonaire standard qui évaluent la fonction motrice respiratoire comprennent les résultats spirometrical et maximum pression des voies aériennes: la capacité vitale forcée (CVF), le volume expiratoire maximal en une seconde (VEMS 1), la pression inspiratoire maximale (PI max) et pression expiratoire maximale (PE max) 4,5. Ces valeurs constituent des mesures indirectes de la performance musculaire respiratoire 6. Dans la pratique clinique et la recherche, une électromyographie de surface (EMG) a enregistré des muscles respiratoirespeut être utilisé pour évaluer la fonction motrice respiratoires et aider à diagnostiquer la pathologie neuromusculaire. Cependant, la variabilité de l&#39;amplitude EMG inhibe les efforts pour développer des mesures objectives et directes de la fonction motrice respiratoire 6. Basé sur une approche EMG multi-musculaire pour caractériser commande motrice des muscles des membres inférieurs 7, connus sous le nom de l&#39;indice de réponse volontaire (VRI) 8, nous avons développé un outil d&#39;analyse pour caractériser le contrôle moteur respiratoires directement à partir de sEMG données enregistrées à partir de plusieurs muscles respiratoires pendant le volontaire tâches respiratoires. Nous avons appelé cela le respiratoire évaluation de contrôle moteur (MRAC) 9. Cette méthode d&#39;analyse vectorielle quantifie le montant et la répartition des activités sur les muscles et les présente sous la forme d&#39;un index qui concerne le degré de sortie sEMG dans un essai-sujet ressemble à celle d&#39;un groupe de santé (non-blessés) contrôles. La valeur de l&#39;indice qui en résulte a été démontré qu&#39;ils ont une grande validité apparente, la sensibilitéet la spécificité 9-11. Nous avons montré précédemment que les résultats 9 MRAC corrélation significative avec les niveaux de SCI et des mesures de la fonction pulmonaire. Nous présentons ici la méthode pour comparer quantitativement blessures respiratoires modèles d&#39;activation multi-musculaires de la moelle épinière après à ceux de personnes en bonne santé.

La figure 3 représente l&#39;électromyogramme et la pression des voies aériennes (en haut) simultanément enregistrée au cours MEPT d&#39;un non-blessés (à gauche) et SCI individus (à droite). Remarque diminution de la pression des voies aériennes et l&#39;absence de sEMG activité des muscles expiratoires chez un sujet SCI par rapport à un individu non-blessés (marqué d&#39;ellipses grises). Notez également que début de la tâche, comme indiqué sur le fond, est associée à une augmentati...

Watch this Scientific Journal Video about Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment RMCA in Individuals with Chronic Spinal Cord Injury at JoVE.com

Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment RMCA in Individuals with Chronic Spinal Cord Injury

Le but de cette publication est de présenter notre travail original sur une approche électromyographique surface multi-musculaire pour caractériser quantitativement les modèles d&#39;activation musculaire des voies respiratoires chez les personnes souffrant de lésions de la moelle épinière chronique en utilisant une analyse basée sur un vecteur.

Evaluation de l&#39;activation des muscles respiratoires aide respiratoire évaluation du contrôle moteur (MRAC) chez les personnes atteintes de maladies chroniques Spinal Cord Injury

During breathing, activation of respiratory muscles is coordinated by integrated input from the brain, brainstem, and spinal cord. When this coordination ...

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Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment (RMCA) in Individuals with Chronic Spinal Cord Injury

10.2K vues.  University of Louisville. Le but de cette publication est de présenter notre travail original sur une approche électromyographique surface multi-musculaire pour caractériser quantitativement les modèles d'activation musculaire des voies respiratoires chez les personnes souffrant de lésions de la moelle épinière chronique en utilisant une analyse basée sur un vecteur.

Vidéo: Evaluation of Respiratory Muscle Activation Using Respiratory Motor Control Assessment RMCA in Individuals with Chronic Spinal Cord Injury

Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology

Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher frequency of fractures 1. As these fractures often occur in regions that have lost normal sensory function, the patient is at a greater risk of fracture-dependent pathologies, including death. SCI-dependent loss in both bone mineral density (BMD, grams/cm2) and bone mineral content (BMC, grams) has been attributed to mechanical disuse 2, aberrant neuronal signaling 3 and hormonal changes 4. The use of rodent models of SCI-induced osteoporosis can provide invaluable information regarding the mechanisms underlying the development of osteoporosis following SCI as well as a test environment for the generation of new therapies 5-7 (and reviewed in 8). Mouse models of SCI are of great interest as they permit a reductionist approach to mechanism-based assessment through the use of null and transgenic mice. While such models have provided important data, there is still a need for minimally-invasive, reliable, reproducible, and quantifiable methods in determining the extent of bone loss following SCI, particularly over time and within the same cohort of experimental animals, to improve diagnosis, treatment methods, and/or prevention of SCI-induced osteoporosis.
An ideal method for measuring bone density in rodents would allow multiple, sequential (over time) exposures to low-levels of X-ray radiation. This study describes the use of a new whole-animal scanner, the IVIS Lumina XR (Caliper Instruments) that can be used to provide low-energy (1-3 milligray (mGy)) high-resolution, high-magnification X-ray images of mouse hind limb bones over time following SCI. Significant bone density loss was seen in the tibiae of mice by 10 days post-spinal transection when compared to uninjured, age-matched control (na&iuml;ve) mice (13% decrease, p&lt;0.0005). Loss of bone density in the distal femur was also detectable by day 10 post-SCI, while a loss of density in the proximal femur was not detectable until 40 days post injury (7% decrease, p&lt;0.05). SCI-dependent loss of mouse femur density was confirmed post-mortem through the use of Dual-energy X-ray Absorptiometry (DXA), the current "gold standard" for bone density measurements. We detect a 12% loss of BMC in the femurs of mice at 40 days post-SCI using the IVIS Lumina XR. This compares favorably with a previously reported BMC loss of 13.5% by Picard and colleagues who used DXA analysis on mouse femurs post-mortem 30 days post-SCI 9. Our results suggest that the IVIS Lumina XR provides a novel, high-resolution/high-magnification method for performing long-term, longitudinal measurements of hind limb bone density in the mouse following SCI.

Longitudinal Evaluation of Mouse Hind Limb Bone Loss After Spinal Cord Injury using Novel, in vivo, Methodology

A longitudinal examination of bone loss in the femurs and tibiae of adult mice was performed following spinal cord injury using sequential low-dose X-ray scans. Tibia bone loss was detected throughout the study, while bone loss in the femur was not detected until 40 days post injury.

Évaluation longitudinale des souris Limb perte osseuse Hind après un traumatisme médullaire utilisant Novel, In vivo Méthodologie

Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher ...

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Médecine

Acute and Chronic Tactile Sensory Testing after Spinal Cord Injury in Rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory testing in rat SCI models is needed. However, until recently, no single testing approach had been validated for SCI so that standardized methods have not been implemented across labs. Additionally, available testing methods could not be implemented acutely or when severe motor impairments existed, preventing studies of the development of SCI-induced allodynia3. Here we present two validated sensory testing methods using von Frey Hair (VFH) monofilaments which quantify changes in tactile sensory thresholds after SCI4-5. One test is the well-established Up-Down test which demonstrates high sensitivity and specificity across different SCI severities when tested chronically5. The other test is a newly-developed dorsal VFH test that can be applied acutely after SCI when allodynia develops, prior to motor recovery4-5. Each VFH monofilament applies a calibrated force when touched to the skin of the hind paw until it bends. In the up-down method, alternating VFHs of higher or lower forces are used on the plantar L5 dermatome to delineate flexor withdrawal thresholds. Successively higher forces are applied until withdrawal occurs then lower force VFHs are used until withdrawal ceases. The tactile threshold reflects the force required to elicit withdrawal in 50% of the stimuli. For the new test, each VFH is applied to the dorsal L5 dermatome of the paw while the rat is supported by the examiner. The VFH stimulation occurs in ascending order of force until at least 2 of 3 applications at a given force produces paw withdrawal. Tactile sensory threshold is the lowest force to elicit withdrawal 66% of the time. Acclimation, testing and scoring procedures are described. Aberrant trials that require a retest and typical trials are defined. Animal use was approved by Ohio State University Animal Care and Use Committee.

We describe two tactile sensory testing methods for acute or chronic periods of spinal cord injury in rats. These validated procedures can detect the development and maintenance of allodynia-like sensations.

Aiguë et chronique Test tactile sensorielle après un traumatisme médullaire chez le rat

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory ...

A Murine Model of Cervical Spinal Cord Injury to Study Post-lesional Respiratory Neuroplasticity

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed to improve/ameliorate the respiratory failure following high cervical spinal cord injury (SCI). Here we propose a murine pre-clinical model of high SCI at the cervical 2 (C2) metameric level to study diverse post-lesional respiratory neuroplasticity. The technique consists of a surgical partial injury at the C2 level, which will induce a hemiparalysis of the diaphragm due to a deafferentation of the phrenic motoneurons from the respiratory centers located in the brainstem. The contralateral side of the injury remains intact and allows the animal recovery. Unlike other SCIs which affect the locomotor function (at the thoracic and lumbar level), the respiratory function does not require animal motivation and the quantification of the deficit/recovery can be easily performed (diaphragm and phrenic nerve recordings, whole body ventilation). This pre-clinical C2 SCI model is a powerful, useful, and reliable pre-clinical model to study various respiratory and non-respiratory neuroplasticity events at different levels (molecular to physiology) and to test diverse putative therapeutic strategies which might improve the respiration in SCI patients.

Respiratory failure is the leading cause of death following a cervical spinal cord injury. Having a reproducible, quantifiable, and reliable pre-clinical animal model of respiratory failure induced by a partial cervical injury will help to understand the subsequent respiratory and non-respiratory neuroplasticity and allow testing putative repair strategies.

Un modèle murin de la moelle épinière cervicale blessures à étude post-lésionnelle respiratoire neuroplasticité

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed ...

Controlled Cortical Impact Model for Traumatic Brain Injury

Every year over a million Americans suffer a traumatic brain injury (TBI). Combined with the incidence of TBIs worldwide, the physical, emotional, social, and economical effects are staggering. Therefore, further research into the effects of TBI and effective treatments is necessary. The controlled cortical impact (CCI) model induces traumatic brain injuries ranging from mild to severe. This method uses a rigid impactor to deliver mechanical energy to an intact dura exposed following a craniectomy. Impact is made under precise parameters at a set velocity to achieve a pre-determined deformation depth. Although other TBI models, such as weight drop and fluid percussion, exist, CCI is more accurate, easier to control, and most importantly, produces traumatic brain injuries similar to those seen in humans. However, no TBI model is currently able to reproduce pathological changes identical to those seen in human patients. The CCI model allows investigation into the short-term and long-term effects of TBI, such as neuronal death, memory deficits, and cerebral edema, as well as potential therapeutic treatments for TBI.

Traumatic brain injuries (TBIs) remain a serious health problem. Using the controlled cortical impact surgery model, research on the effects of TBI and possible treatment methods may be performed.

Contrôlée corticale modèle d&#39;impact pour Traumatic Brain Injury

Every year over a million Americans suffer a traumatic brain injury (TBI).  Combined with the incidence of TBIs worldwide, the physical, emotional, ...

A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb.

We present a protocol for using a radio-telemetric system to record cardiovascular parameters in T4 spinal cord transected rats eight weeks after embryonic brainstem neural stem cell grafting into the lesion site. Telemetry is an advanced technique to accurately evaluate cardiovascular function in conscious freely moving spinal cord injured rats.

Un système de radio-télémétrique de surveiller la fonction cardiovasculaire chez le rat avec la moelle épinière Transection et embryonnaires souches neurales greffes cellulaires

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter ...

Contrast Enhanced Ultrasound Imaging for Assessment of Spinal Cord Blood Flow in Experimental Spinal Cord Injury

Reduced spinal cord blood flow (SCBF) (i.e., ischemia) plays a key role in traumatic spinal cord injury (SCI) pathophysiology and is accordingly an important target for neuroprotective therapies. Although several techniques have been described to assess SCBF, they all have significant limitations. To overcome the latter, we propose the use of real-time contrast enhanced ultrasound imaging (CEU). Here we describe the application of this technique in a rat contusion model of SCI. A jugular catheter is first implanted for the repeated injection of contrast agent, a sodium chloride solution of sulphur hexafluoride encapsulated microbubbles. The spine is then stabilized with a custom-made 3D-frame and the spinal cord dura mater is exposed by a laminectomy at ThIX-ThXII. The ultrasound probe is then positioned at the posterior aspect of the dura mater (coated with ultrasound gel). To assess baseline SCBF, a single intravenous injection (400 &#181;l) of contrast agent is applied to record its passage through the intact spinal cord microvasculature. A weight-drop device is subsequently used to generate a reproducible experimental contusion model of SCI. Contrast agent is re-injected 15 min following the injury to assess post-SCI SCBF changes. CEU allows for real time and in-vivo assessment of SCBF changes following SCI. In the uninjured animal, ultrasound imaging showed uneven blood flow along the intact spinal cord. Furthermore, 15 min post-SCI, there was critical ischemia at the level of the epicenter while SCBF remained preserved in the more remote intact areas. In the regions adjacent to the epicenter (both rostral and caudal), SCBF was significantly reduced. This corresponds to the previously described &#8220;ischemic penumbra zone&#8221;. This tool is of major interest for assessing the effects of therapies aimed at limiting ischemia and the resulting tissue necrosis subsequent to SCI.

Contrast Enhanced Ultrasound imaging is a reliable in-vivo tool for quantifying spinal cord blood flow in an experimental rat spinal cord injury model. This paper contains a comprehensive protocol for application of this technique in association with a contusion model of thoracic spinal cord injury.

Contraste échographie amélioré pour l&#39;évaluation de la moelle épinière flux sanguin dans la partie expérimentale Traumatisme médullaire

Reduced spinal cord blood flow (SCBF) (i.e., ischemia) plays a key role in traumatic spinal cord injury (SCI) pathophysiology and is accordingly an ...

A Component-resolved Diagnostic Approach for a Study on Grass Pollen Allergens in Chinese Southerners with Allergic Rhinitis and/or Asthma

Sensitization to grass pollen imposes a global risk for allergic airway diseases. Although prevention relies on local investigation of the pollen allergens, data on this topic are limited in southern China. Any available data were obtained by self-report questionnaires, skin prick tests, and total or specific IgE tests using crude extracts. For many reasons, these methods are unreliable. Serum sIgE reactivity to Bermuda grass, Timothy grass, and Humulus scandens allergens in a cohort of patients from Greater Guangzhou (southern China&#39;s largest city and its outskirts) with allergic rhinitis and/or asthma were examined using a fully-automated immunoassay analyzer as a component-resolved diagnostics (CRD) tool.
For the first time, a considerably high prevalence of Bermuda grass sIgE positivity was demonstrated in Chinese southerners with allergic rhinitis and/or asthma. In these patients, a subtle prevalence of sensitization to Timothy grass and Humulus scandens was also noted, which may arise from cross-reactivity, as the latter two are not common in the region. This was also supported by the detection of allergen components.
Fully-automated immunoassay analyzers may offer satisfactory consistency between regions, laboratories, and institutions and over time. The automaticity of the instrument may enable a standardized detection that would not have been readily revealed before the advent of CRD.
This is a study that uses a CRD approach to investigate sensitization to grass pollen allergens in southern China. It adds to current evidence in the literature. Future studies are needed to validate these findings. However, although CRD is a useful tool, the findings made with the fully-automated immunoassay analyzer should not substitute for other laboratory investigations, clinical evaluations, and physician expertise.

This work describes a protocol that uses a component-resolved approach to study sensitization to grass pollen allergens in a cohort of patients from southern China with allergic rhinitis and/or asthma.

Une approche de diagnostic résolue par un composant pour une étude sur les allergènes au pollen dans les ressortissants chinois avec la rhinite allergique et / ou l&#39;asthme

Sensitization to grass pollen imposes a global risk for allergic airway diseases. Although prevention relies on local investigation of the pollen ...

Generation of a Chronic Obstructive Pulmonary Disease Model in Mice by Repeated Ozone Exposure

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation and lung parenchymal destruction. It has a very high incidence in aging populations. The current conventional therapies for COPD focus mainly on symptom-modifying drugs; thus, the development of new therapies is urgently needed. Qualified animal models of COPD could help to characterize the underlying mechanisms and can be used for new drug screening. Current COPD models, such as lipopolysaccharide (LPS) or the porcine pancreatic elastase (PPE)-induced emphysema model, generate COPD-like lesions in the lungs and airways but do not otherwise resemble the pathogenesis of human COPD. A cigarette smoke (CS)-induced model remains one of the most popular because it not only simulates COPD-like lesions in the respiratory system, but it is also based on one of the main hazardous materials that causes COPD in humans. However, the time-consuming and labor-intensive aspects of the CS-induced model dramatically limit its application in new drug screening. In this study, we successfully generated a new COPD model by exposing mice to high levels of ozone. This model demonstrated the following: 1) decreased forced expiratory volume 25, 50, and 75/forced vital capacity (FEV25/FVC, FEV50/FVC, and FEV75/FVC), indicating the deterioration of lung function; 2) enlarged lung alveoli, with lung parenchymal destruction; 3) reduced fatigue time and distance; and 4) increased inflammation. Taken together, these data demonstrate that the ozone exposure (OE) model is a reliable animal model that is similar to humans because ozone overexposure is one of the etiological factors of COPD. Additionally, it only took 6 - 8 weeks, based on our previous work, to create an OE model, whereas it requires 3 - 12 months to induce the cigarette smoke model, indicating that the OE model might be a good choice for COPD research.

This study describes the successful generation of a new chronic obstructive pulmonary disease (COPD) animal model by repeatedly exposing mice to high concentrations of ozone.

Génération d’un modèle de maladie pulmonaire Obstructive chronique chez les souris par exposition à l’Ozone répétées

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation and lung parenchymal destruction. It has a very high ...

Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via recanalization of the coronary artery is the most effective strategy for reducing the size of ischemic myocardium. The coronary microvasculature cannot be visualized and imaged&#160;in vivo, but there are several invasive and noninvasive techniques that can be used to assess parameters which depend directly on coronary microvascular function. The endothelial function after ischemia reperfusion can be assessed also at the level of the coronary circulation via the coronary flow reserve (CFR).&#160;In this study, peak velocity of left anterior descending (LAD) coronary arteries was measured in rats in vivo via Transthoracic Doppler Echocardiography during resting and stress challenge (induced by Dobutamine). A normal heart can increase its coronary blood flow up to four times above the resting values during stress induction. Following ischemia reperfusion, we found a significantly diminished CFR, which can be used as a marker of coronary microvascular dysfunction. CFR has opened a window on the importance of microvascular dysfunction and has been shown to predict cardiovascular risk independent of whether the severe obstructive disease is present.

Coronary flow reserve (CFR), is defined as the ratio of maximal coronary blood flow to the resting coronary blood flow. We present a protocol for evaluating CFR in rats via ultrasound, which offers the opportunity to predict cardiovascular risk factors in the absence of obstructive coronary disease.

Évaluation de la réserve de flux coronaire après la réperfusion d'ischémie myocardique chez les rats

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via ...

Employing the Forced Oscillation Technique for the Assessment of Respiratory Mechanics in Adults

There is increasing interest in the use of the forced oscillation technique (FOT) or oscillometry to characterize respiratory mechanics in healthy and diseased individuals. FOT, a complementary method to traditional pulmonary function testing, utilizes a range of oscillatory frequencies superimposed on tidal breathing to measure the functional relationship between airway pressure and flow. This passive assessment provides an estimate of respiratory system resistance (Rrs) and reactance (Xrs) that reflect airway caliber and energy storage and dissipation, respectively. Despite the recent increase in popularity and updated Technical Standards, clinical adoption has been slow which relates, in part, to the lack of standardization regarding the acquisition and reporting of FOT data. The goal of this article is to address the lack of standardization across laboratories by providing a comprehensive written protocol for FOT and an accompanying video. To illustrate that this protocol can be utilized irrespective of a particular device, three separate FOT devices have been employed in the case examples and video demonstration. This effort is intended to standardize the use and interpretation of FOT, provide practical suggestions, as well as highlight future questions that need to be addressed.

As the use of forced oscillation technique (FOT) is increasingly utilized to characterize respiratory mechanics, there is a need to standardize methods with respect to nascent technical guidelines and various manufacturer's recommendations. A detailed protocol is provided including FOT assessment and interpretation for two cases to facilitate the standardization of methods.

Utilisation de la technique d’oscillation forcée pour l’évaluation de la mécanique respiratoire chez les adultes

There is increasing interest in the use of the forced oscillation technique (FOT) or oscillometry to characterize respiratory mechanics in healthy and ...