Soutenu par le NIH RO1 prix HL073087, GM 077185, 069589 et GM à CKS. Le travail est également soutenue par une subvention du Programme de médecine régénératrice de l&#39;DHLRI. Les auteurs sont reconnaissants à l&#39;appui technique et les intrants cliniques du personnel suivant à l&#39;Université Ohio State: Dr Sabyasachi.Biswas (Centre plaies complète), le Dr Allison Spiwak (Division de la technologie de circulation), Joseph Agoston (Division de circulation), Thoma Shives (Division du prêt), Joseph Ewing (génie mécanique), Scott Killinger (génie mécanique), et Xiaoyin Ge (génie électrique).

<ol>
	<li>Myers, D. E., Anderson, L. D., Seifert, R. P., Ortner, J. P., Cooper, C. E., Beilman, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+method+for+measuring+local+hemoglobin+oxygen+saturation+in+tissue+using+wide+gap+second+derivative+near-infrared+spectroscopy.">Noninvasive method for measuring local hemoglobin oxygen saturation in tissue using wide gap second derivative near-infrared spectroscopy.</a> J Biomed Opt. 10 (3), 034017-034017 (2005).</li><li>Jarm, T., Kragelj, R., Liebert, A., Lukasiewitz, P., Erjavec, T., Preseren-Strukelj, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postocclusive+reactive+hyperemia+in+healthy+volunteers+and+patients+with+peripheral+vascular+disease+measured+by+three+noninvasive+methods.">Postocclusive reactive hyperemia in healthy volunteers and patients with peripheral vascular disease measured by three noninvasive methods.</a> Adv Exp Med Biol. 530, 661-669 (2003).</li><li>Treacher, D. F., Leach, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen+transport-1.+Basic+principles.">Oxygen transport-1. Basic principles.</a> Bmj. 317 (7168), 1302-1306 (1998).</li><li>Leach, R. M., Treacher, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen+transport-2.+Tissue+hypoxia.">Oxygen transport-2. Tissue hypoxia.</a> BMJ. 317 (7169), 1370-1373 (1998).</li><li>Sen, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wound+healing+essentials:+let+there+be+oxygen.">Wound healing essentials: let there be oxygen.</a> Wound Repair Regen. 17 (1), 1-18 (2009).</li><li>RL, G. r. e. e. n. m. a. n., Panasyuk, S., Wang, X., TE, L. y. o. n. s., Dinh, T., Longoria, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+changes+in+the+skin+microcirculation+and+muscle+metabolism+of+the+diabetic+foot.">Early changes in the skin microcirculation and muscle metabolism of the diabetic foot.</a> Lancet. 366 (9498), 1711-1717 (2005).</li><li>Valvano, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The use of thermal diffusivity to quantify tissue perfusion [dissertation]. , (1981).</li><li>Hassan, M., Togawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+skin+thermal+inertia+distribution+during+reactive+hyperaemia+using+a+single-hood+measurement+system.">Observation of skin thermal inertia distribution during reactive hyperaemia using a single-hood measurement system.</a> Physiol Meas. 22 (1), 187-200 (2001).</li><li>Ley, O., Deshpande, C., Prapamcham, B., Naghavi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumped+parameter+thermal+model+for+the+study+of+vascular+reactivity+in+the+fingertip.">Lumped parameter thermal model for the study of vascular reactivity in the fingertip.</a> J Biomech Eng. 130 (3), 031012-031012 (2008).</li><li>Wilson, S. B., Spence, V. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+thermographic+imaging+method+for+quantifying+dermal+perfusion:+potential+and+limitations.">Dynamic thermographic imaging method for quantifying dermal perfusion: potential and limitations.</a> Med Biol Eng Comput. 27 (5), 496-501 (1989).</li></ol>

L&#39;oxygène existe dans les tissus biologiques dans des formes multiples, telles que l&#39;hémoglobine en oxygène ou de myoglobine liés, l&#39;oxygène dissous, et les espèces réactives de l&#39;oxygène. Transport de l&#39;oxygène joue un rôle crucial dans le maintien de la viabilité des tissus et des processus métaboliques normaux 3. Bénigne aiguë à l&#39;hypoxie modérée lancera adaptation métabolique, la régulation vasculaire, et les réponses angiogéniques 4. Hypoxie et l&#39;anoxie extrême mènera à l&#39;angiogenèse insuffisante et la mort cellulaire. Le déséquilibre entre l&#39;apport en oxygène limitée et la demande accrue d&#39;oxygène est un des principaux facteurs à l&#39;origine pour de nombreux troubles tels que les plaies chroniques 5. Dans le cas de plaies ischémiques, l&#39;approvisionnement en oxygène est limitée par le manque de perfusion et ne peuvent satisfaire les besoins métaboliques du processus de guérison et de compromettre la fonction explosion respiratoire visant à combattre l&#39;infection. L&#39;évaluation simultanée de l&#39;oxygénation des tissus cutanés et la fonction vasculaire a une importance clinique dans le traitement des plaies chroniques. La technique d&#39;imagerie hyperspectrale estimations oxygénation des tissus cutanés par le tissu éclairant et de détecter la réflectance des tissus à différentes longueurs d&#39;onde 6. Un avantage majeur de l&#39;imagerie hyperspectrale est non invasive et sans contact de détection de propriétés des tissus fonctionnels. Cependant, la fiabilité de la mesure d&#39;oxygène pour de nombreux systèmes d&#39;imagerie hyperspectrale est affectée par la couleur de peau et d&#39;autres variations d&#39;absorption de fond. Large spectroscopie dérivée seconde lacune a été développé précédemment pour la mesure de l&#39;oxygénation tissulaire avec un effet minimal de diffusion et une pigmentation de la peau. Nous avons appliqué le principe de la spectroscopie dérivée seconde à l&#39;imagerie multispectrale et a démontré la mesure cohérente de l&#39;oxygénation des tissus cutanés indépendants avec les changements simulés couleur de la peau. Perfusion tissulaire a été préalablement étudiée en mesurant 7 diffusivité thermique des tissus. Une méthode simple capot a été développé pour introduire une stimulation thermique et les réponses des tissus image dynamique en vue d&#39;estimer le tissu cutané inertie thermique de distribution 8. Expériences sur la peau avant-bras humain soumis à une occlusion artérielle coiffe démontré de relation linéaire entre l&#39;inertie thermique et de la perfusion artérielle mesurée par un imageur laser à effet Doppler avant et pendant l&#39;occlusion du flux sanguin 8. Un modèle biochaleur regroupées a également été utilisé pour estimer la réactivité du bout des doigts vasculaires pendant l&#39;occlusion veineuse pléthysmographie 9. Malgré les efforts ci-dessus, la quantification de la perfusion sanguine cutanée à partir de mesures de température cutanée est difficile en raison du manque de sensibilité, de la dépendance des sous-cutanée épaisseur du gras, et d&#39;autres facteurs tels que la vasoconstriction, vasodilatation, et 10 artefacts de mouvement. Dans ce protocole, nous avons utilisé une caméra infrarouge pour capter la dynamique température des tissus en réponse à une stimulation thermique à température ambiante. La stimulation thermique a été choisi afin que l&#39;effet de vasoconstriction et la vasodilatation a été minimisé. La modélisation et des efforts de mesure sont nécessaires afin de délimiter une corrélation quantitative fiable entre l&#39;indice de la fonction vasculaire et la perfusion des tissus cutanés. En n ° 3, nous avons utilisé la transformation affine pour les tâches de co-inscription. Toutefois, étant donné que les deux caméras sont positionnées avec des angles différents dans l&#39;espace 3D, il est potentiellement plus précis pour appliquer une transformation liée à la transformation 3D entre les deux caméras. Actuellement, nous étudions dans cette direction qui impliquent l&#39;étalonnage extrinsèques des caméras dans l&#39;espace 3D en utilisant la géométrie épipolaire.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Higgins Calligraphy waterproof black ink</td>
<td>&nbsp;</td>
<td>Sanford</td>
<td>44314</td>
<td>diluted to 1%</td>
</tr>
<tr>
<td>Hamamatsu ORCA ER deep cooling CCD camera</td>
<td>&nbsp;</td>
<td>Hamamatsu, Bridgewater, NJ</td>
<td>C4742-80-12AG</td>
<td>&nbsp;</td>
<tr>
<td>Varispec SNIR liquid crystal tunable filter</td>
<td>&nbsp;</td>
<td>Cambridge Research Inc., Cambridge, MA</td>
<td>VIS-10-HC-20</td>
<td>&nbsp;</td>
<tr>
<td>ThermoVision A40 infrared camera</td>
<td>&nbsp;</td>
<td>FLIR Systems Inc.,Sweden</td>
<td>A40</td>
<td>&nbsp;</td>
<tr>
<td>Thorlabs OSL1 high intensity fiber light source</td>
<td>&nbsp;</td>
<td>Thorlabs</td>
<td>OSL1</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

dual-mode imaging of cutaneous tissue oxygenation and vascular function

L&#39;évaluation précise de l&#39;oxygénation des tissus cutanés et la fonction vasculaire est important pour la détection appropriée, mise en scène, et le traitement des troubles de santé tels que de nombreuses plaies chroniques. Nous rapportons le développement d&#39;un système d&#39;imagerie bi-mode pour l&#39;imagerie non-invasive et sans contact de l&#39;oxygénation des tissus cutanés et la fonction vasculaire. Le système d&#39;imagerie intégrée une caméra infrarouge, une caméra CCD, un filtre à cristaux liquides accordable et une source de fibres à haute intensité de lumière. Une interface Labview a été programmé pour le contrôle de l&#39;équipement, la synchronisation, l&#39;acquisition d&#39;images, de traitement et de visualisation. Images multispectrales capturée par la caméra CCD ont été utilisés pour reconstruire la carte oxygénation des tissus. Dynamique images thermographiques capturée par la caméra infrarouge ont été utilisés pour reconstruire la carte de la fonction vasculaire. L&#39;oxygénation des tissus cutanés et les images de la fonction vasculaire ont été co-enregistré par le biais des marqueurs fiduciaires. Les caractéristiques de performance du système de l&#39;image bi-mode ont été testés chez les humains.

Watch this Scientific Journal Video about Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function at JoVE.com

Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function

Un système bi-mode d&#39;imagerie a été développé pour les non-contact avec l&#39;évaluation de l&#39;oxygénation des tissus cutanés et la fonction vasculaire.

Double mode d&#39;imagerie de l&#39;oxygénation des tissus cutanés et la fonction vasculaire

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health ...

dual-mode-imaging-cutaneous-tissue-oxygenation-vascular

Research

JoVE Journal

Medicine

16.4K vues.  The Ohio State University. Un système bi-mode d'imagerie a été développé pour les non-contact avec l'évaluation de l'oxygénation des tissus cutanés et la fonction vasculaire.

Vidéo: Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function

Diagnostic Ultrasound Imaging of Mouse Diaphragm Function

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive surgical procedures. Although this is an effective method of assessing in vitro diaphragm activity, it involves non-survival surgery. The application of non-invasive ultrasound imaging as an in vivo procedure is beneficial since it not only reduces the number of animals sacrificed, but is also suitable for monitoring disease progression in live mice. Thus, our ultrasound imaging method may likely assist in the development of novel therapies that alleviate muscle injury induced by various respiratory diseases. Particularly, in clinical diagnoses of obstructive lung diseases, ultrasound imaging has the potential to be used in conjunction with other standard tests to detect the early onset of diaphragm muscle fatigue. In the current protocol, we describe how to accurately evaluate diaphragm contractility in a mouse model using a diagnostic ultrasound imaging technique.

Diagnostic ultrasound imaging has proven to be effective in diagnosing various respiratory diseases in human and animal subjects. We demonstrate a comprehensive ultrasound protocol utilized by Dr. Zuo's lab to analyze diaphragm kinetics specifically in mouse models. This is also a non-invasive research technique which can provide quantitative information on mouse respiratory muscle function.

L&#39;échographie diagnostique de souris membrane Fonction

Function analysis of rodent respiratory skeletal muscles, particularly the diaphragm, is commonly performed by isolating muscle strips using invasive ...

Recherche

Médecine

Assessment of Vascular Function in Patients With Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this is only partially explained by traditional CVD risk factors. Vascular dysfunction is an important non-traditional risk factor, characterized by vascular endothelial dysfunction (most commonly assessed as impaired endothelium-dependent dilation [EDD]) and stiffening of the large elastic arteries. While various techniques exist to assess EDD and large elastic artery stiffness, the most commonly used are brachial artery flow-mediated dilation (FMDBA) and aortic pulse-wave velocity (aPWV), respectively. Both of these noninvasive measures of vascular dysfunction are independent predictors of future cardiovascular events in patients with and without kidney disease. Patients with CKD demonstrate both impaired FMDBA, and increased aPWV. While the exact mechanisms by which vascular dysfunction develops in CKD are incompletely understood, increased oxidative stress and a subsequent reduction in nitric oxide (NO) bioavailability are important contributors. Cellular changes in oxidative stress can be assessed by collecting vascular endothelial cells from the antecubital vein and measuring protein expression of markers of oxidative stress using immunofluorescence. We provide here a discussion of these methods to measure FMDBA, aPWV, and vascular endothelial cell protein expression.

The degree of vascular dysfunction and contributing physiological mechanisms can be assessed in patients with chronic kidney disease by measuring brachial artery flow-mediated dilation, aortic pulse-wave velocity, and vascular endothelial cell protein expression.

L&#39;évaluation de la fonction vasculaire chez les patients atteints de maladie rénale chronique

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this ...

A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis. Damage to the endothelium may predispose the vessel to atherosclerosis and increase the risk for cardiovascular disease. Assessments of peripheral endothelial function are good indicators of early abnormalities in the vascular wall and correlate well with assessments of coronary endothelial function. The present manuscript details the important methodological steps necessary for the assessment of microvascular endothelial function using laser Doppler imaging with iontophoresis, large vessel endothelial function using flow-mediated dilatation, and carotid atherosclerosis using carotid artery ultrasound. A discussion on the methodological considerations for each of the techniques is also presented, and recommendations are made for future research.

The present article describes the methodological considerations for several non-invasive assessments of vascular function and morphology that are commonly used in medical research to assess different stages of atherosclerosis.

Une approche méthodologique pour les évaluations non invasifs de la fonction vasculaire et de morphologie

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis.  Damage to the endothelium may ...

Chronic Thromboembolic Pulmonary Hypertension and Assessment of Right Ventricular Function in the Piglet

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. Pulmonary Hypertension (PH) was induced in 3-week-old piglets by a progressive obstruction of the pulmonary vascular bed. A ligation of the left Pulmonary Artery (PA) was performed first through a mini-thoracotomy. Second, weekly embolizations of the right lower pulmonary lobe were done under fluoroscopic guidance with n-butyl-2-cyanoacrylate during 5 weeks. Mean Pulmonary Arterial Pressure (mPAP) measured by ritght heart catheterism, increased progressively, as well as Right Atrial pressure and Pulmonary Vascular Resistances (PVR) after 5 weeks compared to sham animals. Right Ventricular (RV) structural and functional remodeling were assessed by transthoracic echocardiography (RV diameters, RV wall thickness, RV systolic function). RV elastance and RV-pulmonary coupling were assessed by Pressure-Volume Loops (PVL) analysis with conductance method. Histologic study of the lung and the right ventricle were also performed. Molecular analyses on RV fresh tissues could be performed through repeated transcutaneous endomyocardial biopsies. Pulmonary microvascular disease in obstructed and unobstructed territories was studied from lung biopsies using molecular analyses and pathology. Furthermore, the reliability and the reproducibility was associated with a range of PH severity in animals. Most aspects of the human CTEPH disease were reproduced in this model, which allows new perspectives for the understanding of the underlying mechanisms (mitochondria, inflammation) and new therapeutic approaches (targeted, cellular or gene therapies) of the overloaded right ventricle but also pulmonary microvascular disease.

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Right Ventricular (RV) dysfunction were induced in piglets by progressive obstruction of the pulmonary arteries. Consequences were remarkably similar to those observed in CTEPH patients. This animal model would be a very useful tool for pathophysiology and therapeutic experiments on CTEPH and RV failure.

Chronique thromboembolique l&#39;hypertension artérielle pulmonaire et de l&#39;évaluation de la fonction ventriculaire droite dans la Porcinet

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. ...

Visualization of Vascular and Parenchymal Regeneration after 70% Partial Hepatectomy in Normal Mice

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the silicone compound, via a 26 G catheter, into the portal or hepatic vein. After silicone injection, organs were explanted and prepared for ex-vivo micro-CT (&#181;CT) scanning. The silicone injection procedure is technically challenging. Achieving a successful outcome requires extensive microsurgical experience from the surgeon. One of the challenges of this procedure involves determining the adequate perfusion rate for the silicone compound. The perfusion rate for the silicone compound needs to be defined based on the hemodynamic of the vascular system of interest. Inappropriate perfusion rate can lead to an incomplete perfusion, artificial dilation and rupturing of vascular trees.
The 3D reconstruction of the vascular system was based on CT scans and was achieved using preclinical software such as HepaVision. The quality of the reconstructed vascular tree was directly related to the quality of silicone perfusion. Subsequently computed vascular parameters indicative of vascular growth, such as total vascular volume, were calculated based on the vascular reconstructions. Contrasting the vascular tree with silicone allowed for subsequent histological work-up of the specimen after &#181;CT scanning. The specimen can be subjected to serial sectioning, histological analysis and whole slide scanning, and thereafter to 3D reconstruction of the vascular trees based on histological images. This is the prerequisite for the detection of molecular events and their distribution with respect to the vascular tree. This modified silicone injection procedure can also be used to visualize and reconstruct the vascular systems of other organs. This technique has the potential to be extensively applied to studies concerning vascular anatomy and growth in various animal and disease models.

Tools used for visualizing vascular regeneration require methods for contrasting the vascular trees. This film demonstrated a delicate injection technique used to achieve optimal contrasting of the vascular trees and illustrate the potential benefits resulting from a detailed analysis of the resulting specimen using &#181;CT and histological serial sections.

Visualisation des vasculaire et parenchymateuse Régénération après 70% hépatectomie partielle chez des souris normales

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the ...

Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation

Cardiovascular disease is the leading cause of morbidity and mortality in the world. Atherosclerotic plaques, consisting of lipid-laden macrophages and calcification, develop in the coronary arteries, aortic valve, aorta, and peripheral conduit arteries and are the hallmark of cardiovascular disease. In humans, imaging with computed tomography allows for the quantification of vascular calcification; the presence of vascular calcification is a strong predictor of future cardiovascular events. Development of novel therapies in cardiovascular disease relies critically on improving our understanding of the underlying molecular mechanisms of atherosclerosis. Advancing our knowledge of atherosclerotic mechanisms relies on murine and cell-based models. Here, a method for imaging aortic calcification and macrophage infiltration using two spectrally distinct near-infrared fluorescent imaging probes is detailed. Near-infrared fluorescent imaging allows for the ex vivo quantification of calcification and macrophage accumulation in the entire aorta and can be used to further our understanding of the mechanistic relationship between inflammation and calcification in atherosclerosis. Additionally, a method for isolating and culturing animal aortic vascular smooth muscle cells and a protocol for inducing calcification in cultured smooth muscle cells from either murine aortas or from human coronary arteries is described. This in vitro method of modeling vascular calcification can be used to identify and characterize the signaling pathways likely important for the development of vascular disease, in the hopes of discovering novel targets for therapy.

Vascular calcification is an important predictor of and contributor to human cardiovascular disease. This protocol describes methods for inducing calcification of cultured primary vascular smooth muscle cells and for quantifying calcification and macrophage burden in animal aortas using near-infrared fluorescence imaging.

Calcification vasculaire des cellules musculaires lisses et imagerie de Aortic calcification et Inflammation

Cardiovascular disease is the leading cause of morbidity and mortality in the world.  Atherosclerotic plaques, consisting of lipid-laden macrophages and ...

Assessment of Human Adipose Tissue Microvascular Function Using Videomicroscopy

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. It is hypothesized that pro-atherogenic mediators released from fat tissues particularly in association with central/visceral adiposity may promote pathogenic vascular changes locally and systemically, and the notion that cardiovascular disease may be the consequence of adipose tissue dysfunction continues to evolve. Here, we describe a unique method of videomicroscopy that involves analysis of vasodilator and vasoconstrictor responses of intact small human arterioles removed from the adipose depot of living human subjects. Videomicroscopy is used to examine functional properties of isolated microvessels in response to pharmacological or physiological stimuli using a pressured system that mimics in vivo conditions. The technique is a useful approach to gain understanding of the pathophysiology and molecular mechanisms that contribute to vascular dysfunction locally within the adipose tissue milieu. Moreover, abnormalities in the adipose tissue microvasculature have also been linked with systemic diseases. We applied this technique to examine depot-specific vascular responses in obese subjects. We assessed endothelium-dependent vasodilation to both increased flow and acetylcholine in adipose arterioles (50 - 350 &#181;m internal diameter, 2 - 3 mm in length) isolated from two different adipose depots during bariatric surgery from the same individual. We demonstrated that arterioles from visceral fat exhibit impaired endothelium-dependent vasodilation compared to vessels isolated from the subcutaneous depot. The findings suggest that the visceral microenvironment is associated with vascular endothelial dysfunction which may be relevant to clinical observation linking increased visceral adiposity to systemic disease mechanisms. The videomicroscopy technique can be used to examine vascular phenotypes from different fat depots as well as compare findings across individuals with different degrees of obesity and metabolic dysfunction. The method can also be used to examine vascular responses longitudinally in response to clinical interventions.

Videomicroscopy systems are used to examine functional properties of isolated adipose tissue arterioles in response to physiological and pharmacological stimuli. This technique can be used to examine microvascular phenotypes in different adipose tissue domains in obese humans.

Évaluation de la fonction microvasculaire tissu adipeux humain en utilisant la vidéomicroscopie

While obesity is closely linked to the development of metabolic and cardiovascular disease, little is known about mechanisms that govern these processes. ...

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic demand. Reactive hyperemia (in response to a brief period of tissue ischemia) is an independent predictor of cardiovascular events and provides important insight into vascular health and vasodilatory capacity. Skeletal muscle oxidative capacity is equally important in health and disease, as it determines the energy supply for myocellular processes. Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess each of these major clinical endpoints (reactive hyperemia, neurovascular coupling, and muscle oxidative capacity) during a single clinic or laboratory visit. Unlike Doppler ultrasound, magnetic resonance images/spectroscopy, or invasive catheter-based flow measurements or muscle biopsies, our approach is less operator-dependent, low-cost, and completely non-invasive. Representative data from our lab taken together with summary data from previously published literature illustrate the utility of each of these end-points. Once this technique is mastered, application to clinical populations will provide important mechanistic insight into exercise intolerance and cardiovascular dysfunction.

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with &#039;One Stop Shop&#039; Near-infrared Spectroscopy

Here, we describe a simple, non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia, neurovascular coupling and skeletal muscle oxidative capacity in a single clinic or laboratory visit.

Couplage neurovasculaire Muscle squelettique, la capacité oxydative et microvasculaire fonction avec « One Stop Shop » de spectroscopie proche infrarouge

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic ...

Veno-Venous Extracorporeal Membrane Oxygenation in a Mouse

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for acute as well as end-stage lung diseases. With the increase in clinical demand and prolonged use of ECMO, procedural optimization and prevention of multi-organ damage are of critical importance. The aim of this protocol is to present a detailed technique of veno-venous ECMO in a non-intubated, spontaneously breathing mouse. This protocol demonstrates the technical design of the ECMO and surgical steps. This murine ECMO model will facilitate the study of pathophysiology related to ECMO (e.g., inflammation,bleeding and thromboembolic events). Due to the abundance of genetically modified mice, the molecular mechanisms involved in ECMO-related complications can also be dissected.

Here we present a protocol describing the technique of veno-venous extracorporeal membrane oxygenation (ECMO) in a non-intubated, spontaneously breathing mouse. This murine model of ECMO can be effectively implemented in experimental studies of acute and end-stage lung diseases.

Oxygénation par Membrane extracorporelle veino-veineuse chez une souris

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for ...

Measurement of Tissue Oxygenation Using Near-Infrared Spectroscopy in Patients Undergoing Hemodialysis

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in clinical settings including cardiovascular and brain surgery, neonatal monitoring and prehospital medicine. The NIRS monitoring devices are real-time and noninvasive, and have mainly been used for evaluating cerebral oxygenation in critically ill patients during an operation or intensive care. Thus far, the use of NIRS monitoring in patients with chronic kidney disease (CKD) including hemodialysis (HD) has been limited; therefore, we investigated rSO2 values in some organs during HD. We monitored rSO2 values using a NIRS device transmitting near-infrared light at 2 wavelengths of attachment. The HD patients were placed in a supine position, with rSO2 measurement sensors attached to the foreheads, the right hypochondrium and the lower legs to evaluate rSO2 in the brain, liver and lower leg muscles, respectively. NIRS monitoring could be a new approach to clarify changes in organ oxygenation during HD or factors affecting tissue oxygenation in CKD patients. This article describes a protocol to measure tissue oxygenation represented by rSO2 as applied in HD patients.

We present a protocol to measure regional oxygen saturation (rSO2) in hemodialysis (HD) patients by using a near-infrared spectroscopy monitor. The rSO2 value is an index of tissue oxygenation. This noninvasive and real-time monitoring could be useful for confirming changes in organ oxygenation during HD.

Mesure de l’oxygénation des tissus par spectroscopie proche infrarouge chez des patients sous hémodialyse

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in ...