Agradecemos sinceramente a F. Bierry de asistencia en la producción y edición de video.

Todos los procedimientos que involucran temas de los animales han sido aprobados por el Comité Institucional de Atención Animal Hospital Universitario. 1. La inoculación bacteriana intraarticular <ol><li> Antes de la inyección, anestesiar a los conejos por medio de inyección intramuscular de ketamina (30 mg / kg de peso corporal) se mezcla con xilazina (4 mg / kg) dentro de músculo erector Spinae. Asegúrese de animales son completamente anestesiados por la comprobación de que no responden a pinch pata. Este protocolo proporciona anestesia suficiente para la inyección intraarticular de la articulación de la rodilla. Coloque los animales bajo la máscara de oxígeno durante la anestesia. </li><li> Afeitado rodilla animales. Preparar la rodilla para inyección aséptica por 3 paños alternados de matorral povidona yodada y alcohol seguido de la aplicación de la solución de povidona yodada. </li><li> Identificar manualmente el tendón rotuliano como una estructura elástica en la cara anterior de la rodilla usando una tapa de la aguja estéril como se muestra o una sonda estéril. </li><li&gt; Con el control visual y por vía anterior, coloque una aguja de 25 G por vía percutánea en la rodilla derecha de cada uno de los 12 conejos a través del tendón rotuliano. </li><li> Inyectar cada rodilla con 1 ml de una suspensión bacteriana de Staphylococcus aureus (cepa Neumann) a una concentración de 10 6 UFC / ml. Una inyección sin resistencia confirma la ubicación intra-articular de la punta de la aguja. </li><li> Después de los procedimientos de inyección, mantener al animal bajo la fuente de convección para evitar la pérdida de calor y controlar la frecuencia respiratoria mediante la observación de movimiento del pecho. Una vez despierto, mantener a los animales en jaulas con acceso libre a comida y agua. </li><li> Controlar el dolor mediante la administración de una inyección intramuscular de 0,1 mg / kg de buprenorfina cada 8 h. </li><li> Clínicamente observar conejos cada día, control de las cantidades consumidas de los alimentos y el agua, la pérdida de peso, la temperatura, y el comportamiento general. </li><li> Para la imagen de la fase aguda de la infección por realizar la primera sesión de imágenes MR tan prontocomo un animal presenta pérdida de peso sustancial (10%); generalmente esto ocurre después de aproximadamente 2 días. </li><li> Si se requiere la administración del fármaco por vía intravenosa antes de examen de resonancia magnética, un acceso venoso auricular podrá ser instalado (véase más adelante). </li></ol> 2. El examen MRI Cuando los animales imágenes en vivo, una instalación de cuidado de los animales es un elemento clave para garantizar la comodidad del animal y de la anestesia óptima. Esto permitirá que para obtener los mejores resultados de imagen y asegurar una adquisición de la imagen de reproducción para los estudios longitudinales. Debido al tamaño del animal, el uso de una unidad de MR clínico de tamaño (1,5 T o T 3) es la más adecuada. 8-canal de bobina de rodilla clínica se utiliza, ya que proporciona una resolución adecuada y relación de contraste-a-ruido para la exploración de la rodilla del conejo. <ol><li> Antes de la instalación en el sistema de imagen, instale un acceso venoso periférico a través de una vena auricular. Este acceso servirá para inyectar el agente de contraste. <ol><li> Afeitado y desinfectar el oído. </li><li&gt; Realice el anestesia local mediante inyección subcutánea de lidocaína. </li><li> Inserte un G catéter 25 dentro de la vena auricular lateral. </li><li> Evaluar la permeabilidad mediante la inyección de 1 ml de suero fisiológico estéril. </li><li> Mantener el catéter con tapping adhesivo. </li></ol></li><li> Anestesiar a los animales por medio de inyección intramuscular de ketamina (30 mg / kg de peso corporal) se mezcla con xilazina (4 mg / kg). Los animales son totalmente anestesiado, una vez que no responden a pinch pata. Coloque una máscara facial en el conejo, dándole oxígeno con una velocidad de flujo de 200 ml / min. </li><li> Una vez que esté anestesiado, tener animales en la unidad de RM. Coloque los animales de modo que las rodillas se encuentran en el centro de la bobina de MR. Colocar las patas de los animales en extensión completa, de modo que el eje largo de la tibia es paralelo a la mesa de unidad de imágenes de RM. Utilice cierres de velcro o bolsas de arena para mantener la posición óptima de la pierna. </li><li> Monitoreo Cardio-respiratoria de los animales no se requiere que elprotocolo de anestesia permite anestesia profunda en la respiración espontánea, pero los animales tienen que ser cubiertos para evitar la pérdida de calor inducida por la anestesia. </li><li> MR protocolo se detalla en la Tabla 1. El tiempo promedio para la adquisición total, incluyendo una instalación óptima es de aproximadamente 20 min. </li><li> Realizar la RM en planos diferentes. Sin embargo, el plano transversal de las rodillas (ortogonal a la tibia) es el plano de referencia, ya que garantiza la reproducibilidad de la posición de la imagen anatómica para los exámenes longitudinales secuenciales y permite la correlación óptima con las rebanadas histológicos. </li><li> En la realización de secuencias sin contraste, inyectar el agente de contraste UPSIO a través del acceso venoso auricular. Lentamente administrar las partículas de óxido de hierro en una dosis única de 150 mol de Fe / kg. Enjuague el catéter por la inyección de 1 ml de suero fisiológico estéril. </li><li> Repita el mayor GRE ponderada secuencia 24 horas después de la inyección. Este retardo permite que las partículas sean fagocitadas por loslos macrófagos. </li><li> Para los estudios longitudinales que evalúan fármacos efecto (antibióticos, esteroides, anticuerpos anti-macrófagos, etc.), Repita las pruebas de RM secuenciales utilizando el protocolo descrito anteriormente. </li></ol> 3. Análisis de Imagen <ol><li> Para la evaluación longitudinal de realizar mediciones en el mismo nivel anatómico, y definir un punto de referencia fácilmente identificable. Por ejemplo, la adquisición a través del plano axial donde se observa el mayor diámetro de la rótula es una forma segura de obtener mediciones reproducibles (Figura 1). </li><li> Realizar análisis de imágenes usando un software DICOM basado (como Osirix) o un software de procesamiento de imágenes (ImageJ). </li><li> El uso de software ImageJ, realizar la segmentación de la zona sinovial que demuestra la pérdida de señal USPIO-mejorada GRE imagen ponderada en T2 utilizando la herramienta de dibujo &quot;irregulares área&quot; en la. Una vez que la membrana sinovial con señal oscura se describe, haga clic en &quot;Analizar&quot; para obtener el área /número de píxeles (Figura 2). </li></ol>

<ol>
	<li>Madri, J., Kissane, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflammation+and+healing.">Inflammation and healing.</a> Anderson's Pathology. , 67-110 (1990).</li><li>Sephel, G., Woodward, S., Rubin, R., Strayer, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Repair,+regeneration,+and+fibrosis.">Repair, regeneration, and fibrosis.</a> Rubin's Pathology. , 71-98 (2008).</li><li>Verdrengh, M., Tarkowski, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+macrophages+in+Staphylococcus+aureus-induced+arthritis+and+sepsis.">Role of macrophages in Staphylococcus aureus-induced arthritis and sepsis.</a> Arthritis Rheum. 43 (10), 2276-2282 (2000).</li><li>Heale, J., Speert, D., Burke, B., Lewis, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macrophages+in+bacterial+infection.">Macrophages in bacterial infection.</a> The Macrophage. , 210-252 (2008).</li><li>Bierry, G., 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=Macrophage+activity+in+infected+areas+of+an+experimental+vertebral+osteomyelitis+model:+USPIO-enhanced+MR+imaging--feasibility+study.">Macrophage activity in infected areas of an experimental vertebral osteomyelitis model: USPIO-enhanced MR imaging--feasibility study.</a> Radiology. 248 (1), 114-123 (2008).</li><li>Bierry, G., 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=MRI+of+macrophages+in+infectious+knee+synovitis.">MRI of macrophages in infectious knee synovitis.</a> AJR Am. J. Roentgenol. 194 (6), W521-W526 (2010).</li><li>Lutz, A. M., 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=Detection+of+synovial+macrophages+in+an+experimental+rabbit+model+of+antigen-induced+arthritis:+ultrasmall+superparamagnetic+iron+oxide-enhanced+MR+imaging.">Detection of synovial macrophages in an experimental rabbit model of antigen-induced arthritis: ultrasmall superparamagnetic iron oxide-enhanced MR imaging.</a> Radiology. 233 (1), 149-1457 (2004).</li><li>Weissleder, R., 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=Ultrasmall+superparamagnetic+iron+oxide:+an+intravenous+contrast+agent+for+assessing+lymph+nodes+with+MR+imaging.">Ultrasmall superparamagnetic iron oxide: an intravenous contrast agent for assessing lymph nodes with MR imaging.</a> Radiology. 175 (2), 494-498 (1990).</li><li>Lefevre, S., 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=Septic+arthritis:+monitoring+with+USPIO-enhanced+macrophage+MR+imaging.">Septic arthritis: monitoring with USPIO-enhanced macrophage MR imaging.</a> Radiology. 258 (3), 722-728 (2011).</li><li>Sigovan, M., 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=Rapid-clearance+iron+nanoparticles+for+inflammation+imaging+of+atherosclerotic+plaque:+initial+experience+in+animal+model.">Rapid-clearance iron nanoparticles for inflammation imaging of atherosclerotic plaque: initial experience in animal model.</a> Radiology. 252 (2), 401-409 (2009).</li></ol>

Los autores no tienen nada que revelar.

Mientras que los agentes de contraste a base de gadolinio no específicos proporcionan información sobre el volumen y la perfusión del espacio extracelular, los macrófagos formación de imágenes por MR USPIO-mejorada permite una localización anatómica precisa y una evaluación cualitativa de la infiltración de macrófagos dentro sinovial infectada sin la necesidad de tomar muestras de tejido 9. Debido a su alta sensibilidad, USPIO puede demostrar incluso sutil infiltrado celular presentes en las primer...

Formación de imágenes por resonancia magnética (MRI) se considera que es la modalidad de imagen de elección para la demostración de la sinovitis infecciosa debido a su alta resolución espacial y contraste de los tejidos blandos. Los cambios de señal observadas en la RM en la artritis baja T1 y de alta señal en T2 que refleja el aumento de la presencia de contenido de agua extracelular, y una marcada mejora después de la administración del agente de contraste basado en gadolinio, en consonancia con las conclusiones histológicamente de aumento de la vascularización debido a la vasodilatación y angiogénesis 1. Sin embargo, la RM es a menudo incapaz de demostrar resolución de la infección durante la terapia con antibióticos como realce persistente se puede observar en las articulaciones de pacientes con curado clínicamente y biológicamente artritis séptica debido a la persistencia del espacio extracelular ampliada (tejido de granulación, la cicatriz fibrótica) 2. Además de los cambios extracelulares, células inflamatorias, incluyendo un intenso reclutamiento de macrófagos se infiltran de forma masiva en lainfectados sinovial. Los macrófagos juegan un papel importante tanto en la fase aguda y crónica de la infección bacteriana 3. Inducen la reacción inflamatoria requerida para erradicar los microorganismos patógenos, y coordinar la resolución de la inflamación, como la inflamación inducida por macrófagos persiste mientras tejidos necróticos no se eliminan, la prevención de reparación para comenzar 4. Por lo tanto, la reducción de la infiltración de macrófagos dentro de sinovia infectada después de la terapia eficaz puede ser un indicador fiable de la resolución de la infección. Celular de imagen es capaz de demostrar la infiltración celular específica dentro del tejido patológico. Específico de macrófagos RM usando dirigido agente de contraste ha sido ampliamente investigado y ha demostrado su capacidad para demostrar la inflamación o infección 5-7 conjunta. Después de la inyección intravenosa, tales agentes de contraste dirigidos, tales como partículas de USPIO (óxidos de hierro superparamagnético ultra pequeños) son absorbidos por las células fagocíticas, tales como macrófagos y,debido a sus propiedades magnéticas, inducir cambios de señal en los tejidos que presentan infiltración de macrófagos 8. El seguimiento longitudinal de los cambios en la terapia de señal de RM permite una en la evaluación no invasiva in vivo de la infiltración de macrófagos, y una reducción de USPIO-macrófagos cargados cambios de señal relacionados demostraría éxito de la terapia. El propósito de este informe es presentar la forma de realizar los macrófagos RM no invasiva para controlar la artritis séptica, demostrando la reducción de la infiltración de macrófagos en el líquido sinovial.

<table border="1">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>P904</td>
			<td>Guerbet</td>
			<td></td>
			<td>Dose: 150 &#956;mol Fe/kg</td>
		</tr>
		<tr>
			<td>Ketamine (500 mg/ml ketamine)</td>
			<td>Virbac</td>
			<td></td>
			<td>Dose: 30 mg/kg</td>
		</tr>
		<tr>
			<td>Rompun (20 mg/ml Xylazine)</td>
			<td>Axience</td>
			<td></td>
			<td>Dose: 4 mg/kg</td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>Vetoquinol</td>
			<td></td>
			<td>Dose: 0.1 mg/kg/8 hr</td>
		</tr>
		<tr>
			<td>BD 22 G, 1 inch</td>
			<td>BD Biosciences</td>
			<td>381423</td>
			<td></td>
		</tr>
		<tr>
			<td>BD 25 G, 5/8 inch</td>
			<td>BD Biosciences</td>
			<td>305122</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vivo macrophage imaging using mr targeted contrast agent for longitudinal evaluation of septic arthritis

Los macrófagos son células clave en la iniciación, el desarrollo y la regulación de la respuesta inflamatoria a la infección bacteriana. Los macrófagos son intensamente y cada vez reclutados en las articulaciones sépticas de las fases tempranas de la infección y la infiltración se supone que retroceder una vez que se obtiene la eliminación eficaz de los agentes patógenos. La capacidad de identificar en la actividad de los macrófagos in vivo en una articulación infectada por lo tanto, puede proporcionar dos aplicaciones principales: la detección temprana de la sinovitis aguda y el seguimiento de la terapia. En la detección no invasiva in vivo de los macrófagos se puede realizar con imágenes de resonancia magnética usando nanopartículas de hierro, tales como óxido de hierro superparamagnético ultra pequeño (USPIO). Después de la administración intravascular o intraarticular, USPIO están específicamente fagocitado por los macrófagos activados, y, debido a sus propiedades magnéticas, inducir cambios de señal en los tejidos que presentan infiltración de macrófagos. A quantitativEvaluación de correo del infiltrado es factible, como el área con pérdida de señal (número de píxeles oscuros) observó en eco de gradiente imágenes de RM después de inyección de partículas se correlaciona con la cantidad de hierro en el tejido y por lo tanto refleja el número de células USPIO-cargados. Se presenta aquí un protocolo para realizar las imágenes de macrófagos utilizando USPIO-mejorada imágenes de RM en un modelo animal de artritis séptica, lo que permite una inicial y longitudinal en la evaluación no invasiva in vivo de la infiltración de macrófagos y una evaluación de la acción de la terapia.

En las imágenes sin contraste, la membrana sinovial de las rodillas infectadas presenta una inflamación difusa de la señal intermedia que no es distinguible del tejido blando circundante, mientras que el fémur y la rótula aparecen como estructuras de señal bajos (Figura 1). En las imágenes USPIO-mejoradas, 24 horas después de la administración del agente de contraste, el área sinovial que contiene macrófagos cargados de USPIO demostrará la pérdida de señal <str...

Watch this Scientific Journal Video about In vivo Macrophage Imaging Using MR Targeted Contrast Agent for Longitudinal Evaluation of Septic Arthritis at JoVE.com

In vivo Macrophage Imaging Using MR Targeted Contrast Agent for Longitudinal Evaluation of Septic Arthritis

Demostramos cómo realizar macrófagos RM con contraste superparamagnético ultra pequeño (USPIO) en la artritis séptica, lo que permite una inicial y longitudinales<em&gt; In vivo</em&gt; Evaluación no invasiva de la infiltración de macrófagos y una evaluación de la eficacia de la terapia.

En vivo los macrófagos de imágenes utilizando MR Agente de contraste dirigida para la Evaluación Longitudinal de Artritis séptica

Macrophages are key-cells in the initiation, the development and the regulation of the inflammatory response to bacterial infection. Macrophages are ...

in-vivo-macrophage-imaging-using-mr-targeted-contrast-agent-for

Research

JoVE Journal

Medicine

In vivo Macrophage Imaging Using MR Targeted Contrast Agent for Longitudinal Evaluation of Septic Arthritis

9.2K vistas.  University Hospital of Strasbourg. Demostramos cómo realizar macrófagos RM con contraste superparamagnético ultra pequeño (USPIO) en la artritis séptica, lo que permite una inicial y longitudinales In vivo Evaluación no invasiva de la infiltración de macrófagos y una evaluación de la eficacia de la terapia.

Video: In vivo Macrophage Imaging Using MR Targeted Contrast Agent for Longitudinal Evaluation of Septic Arthritis

Contrast Enhanced Vessel Imaging using MicroCT

Microscopic computed tomography (microCT) offers high-resolution volumetric imaging of the anatomy of living small animals. However, the contrast between different soft tissues and body fluids is inherently poor in micro-CT images 1. Under these circumstances, visualization of blood vessels becomes a nearly impossible task. To overcome this and to improve the visualization of blood vessels exogenous contrast agents can be used. Herein, we present a methodology for visualizing the vascular network in a rodent model. By using a long-acting aqueous colloidal polydisperse iodinated blood-pool contrast agent, eXIA 160XL, we optimized image acquisition parameters and volume-rendering techniques for finding blood vessels in live animals. Our findings suggest that, to achieve a superior contrast between bone and soft tissue from vessel, multiple-frames (at least 5-8/ frames per view), and 360-720 views (for a full 360&deg; rotation) acquisitions were mandatory. We have also demonstrated the use of a two-dimensional transfer function (where voxel color and opacity was assigned in proportion to CT value and gradient magnitude), in visualizing the anatomy and highlighting the structure of interest, the blood vessel network. This promising work lays a foundation for the qualitative and quantitative assessment of anti-angiogenesis preclinical studies using transgenic or xenograft tumor-bearing mice.

Contrast enhanced small animal vessel imaging by microCT is a rapid, cost-effective and high-throughput technique for serial in situ examination for tumor development, for analyzing the network of blood vessels that nourish them, and for following the response of tumors to preclinical therapeutic intervention(s).

Contraste de imagen mejorada del buque utilizando MicroCT

Microscopic computed tomography (microCT) offers high-resolution volumetric imaging of the anatomy of living small animals. However, the contrast between ...

Investigación

Medicina

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.

Evaluación longitudinal de ratón posteriores pérdida de masa ósea del miembro después de una lesión de la médula espinal utilizando Novel, En vivo Metodología

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

Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time

Intravital imaging has emerged as an indispensable tool in biological research. In the process, many imaging techniques have been developed to study different biological processes in animals non-invasively. However, a major technical limitation in existing intravital imaging modalities is the inability to combine non-invasive, longitudinal imaging with single-cell resolution capabilities. We show here how transplantation into the anterior chamber of the eye circumvents such significant limitation offering a versatile experimental platform that enables non-invasive, longitudinal imaging with cellular resolution in vivo. We demonstrate the transplantation procedure in the mouse and provide representative results using a model with clinical relevance, namely pancreatic islet transplantation. In addition to enabling direct visualization in a variety of tissues transplanted into the anterior chamber of the eye, this approach provides a platform to screen drugs by performing long-term follow up and monitoring in target tissues. Because of its versatility, tissue/cell transplantation into the anterior chamber of the eye not only benefits transplantation therapies, it extends to other in vivo applications to study physiological and pathophysiological processes such as signal transduction and cancer or autoimmune disease development.

Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time

A new approach combining intraocular transplantation and confocal microscopy enables longitudinal, non-invasive real-time imaging with single-cell resolution within grafted tissues in vivo. We demonstrate how to transplant pancreatic islets into the anterior chamber of the mouse eye.

Trasplante en la cámara anterior del ojo para Longitudinal, no invasiva<em&gt; En vivo</em&gt; Imagen con una sola célula de resolución en tiempo real

Intravital imaging has emerged as an indispensable tool in biological research.  In the process, many imaging techniques have been developed to study ...

MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent

Tumor extracellular matrix has abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. In this work, we demonstrated effective MR cancer molecular imaging with a small molecular peptide targeted Gd-DOTA monoamide complex as a targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma. We performed the experiment of evaluating the effectiveness of the agent for non-invasive detection of prostate tumor with MRI in a mouse orthotopic PC-3 prostate cancer model. The targeted contrast agent was effective to produce significant tumor contrast enhancement at a low dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for MR molecular imaging of prostate tumor.

To demonstrate MR cancer molecular imaging with a small peptide targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma in a mouse prostate cancer model.

MR Imagen Molecular del cáncer de próstata con un agente de contraste dirigidos Pequeño Molecular CLT1 Péptido

Tumor extracellular  matrix has abundance of cancer related proteins that can be used as biomarkers  for cancer molecular imaging. In this work,  we ...

In Vivo Optical Imaging of Brain Tumors and Arthritis Using Fluorescent SapC-DOPS Nanovesicles

We describe a multi-angle rotational optical imaging (MAROI) system for in vivo monitoring of physiopathological processes labeled with a fluorescent marker. Mouse models (brain tumor and arthritis) were used to evaluate the usefulness of this method. Saposin C (SapC)-dioleoylphosphatidylserine (DOPS) nanovesicles tagged with CellVue Maroon (CVM) fluorophore were administered intravenously. Animals were then placed in the rotational holder (MARS) of the in vivo imaging system. Images were acquired in 10&#176; steps over 380&#176;. A rectangular&#160;region of interest (ROI) was placed across the full image width at the model disease site. Within the ROI, and for every image, mean fluorescence intensity was computed after background subtraction. In the mouse models studied, the labeled nanovesicles were taken up in both the orthotopic and transgenic brain tumors, and in the arthritic sites (toes and ankles). Curve analysis of the multi angle image ROIs determined the angle with the highest signal. Thus, the optimal angle for imaging each disease site was characterized. The MAROI method applied to imaging of fluorescent compounds is a noninvasive, economical, and precise tool for in vivo quantitative analysis of the disease states in the described mouse models.

In Vivo Optical Imaging of Brain Tumors and Arthritis Using Fluorescent SapC-DOPS Nanovesicles

We describe a multi-angle rotational optical imaging (MAROI) system for in vivo quantitation of a fluorescent marker delivered by saposin C (SapC)-dioleoylphosphatidylserine (DOPS) nanovesicles. Employing mouse models of cancer and arthritis, we demonstrate how the MAROI signal curve analysis can be used for the precise mapping and biological characterization of disease processes.

En vivo de imágenes óptico de tumores del cerebro y la artritis Usando fluorescente SAPC-DOPS nanovesículas

We describe a multi-angle rotational optical imaging (MAROI) system for in vivo monitoring of physiopathological processes labeled with a fluorescent ...

Longitudinal In Vivo Imaging of the Cerebrovasculature: Relevance to CNS Diseases

Remodeling of the brain vasculature is a common trait of brain pathologies. In vivo imaging techniques are fundamental to detect cerebrovascular plasticity or damage occurring overtime and in relation to neuronal activity or blood flow. In vivo two-photon microscopy allows the study of the structural and functional plasticity of large cellular units in the living brain. In particular, the thinned-skull window preparation allows the visualization of cortical regions of interest (ROI) without inducing significant brain inflammation. Repetitive imaging sessions of cortical ROI are feasible, providing the characterization of disease hallmarks over time during the progression of numerous CNS diseases. This technique accessing the pial structures within 250 &#956;m of the brain relies on the detection of fluorescent probes encoded by genetic cellular markers and/or vital dyes. The latter (e.g., fluorescent dextrans) are used to map the luminal compartment of cerebrovascular structures. Germane to the protocol described herein is the use of an in vivo marker of amyloid deposits, Methoxy-O4, to assess Alzheimer&#39;s disease (AD) progression. We also describe the post-acquisition image processing used to track vascular changes and amyloid depositions. While focusing presently on a model of AD, the described protocol is relevant to other CNS disorders where pathological cerebrovascular changes occur.

Longitudinal In Vivo Imaging of the Cerebrovasculature: Relevance to CNS Diseases

This manuscript describes a procedure to track the remodeling of the cerebrovasculature during amyloid plaque accumulation in vivo using longitudinal two-photon microscopy. A thinned-skull preparation enables the visualization of fluorescent dyes to assess the progression of cerebrovascular damage in a mouse model of Alzheimer&#39;s disease.

Longitudinal<em&gt; En Vivo</em&gt; Obtención de imágenes de la vasculatura cerebral: Importancia de las enfermedades del sistema nervioso central

Remodeling of the brain vasculature is a common trait of brain pathologies. In vivo imaging techniques are fundamental to detect cerebrovascular ...

Phase Contrast Magnetic Resonance Imaging in the Rat Common Carotid Artery

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous studies have shown that abnormal blood flow may be associated with systemic vascular risk. Thus, PC-MRI can facilitate the translation of data obtained from animal models of cardiovascular diseases to pertinent clinical investigations. In this report, we describe the procedure for measuring blood flow in the common carotid artery (CCA) of rats using cine-gated PC-MRI and discuss relevant analysis methods. This procedure can be performed in a live, anesthetized animal and does not require euthanasia after the procedure. The proposed scanning parameters yield repeatable measurements for blood flow, indicating excellent reproducibility of the results. The PC-MRI procedure described in this article can be used for pharmacological testing, pathophysiological assessment, and cerebral hemodynamics evaluation.

The overall goal of this procedure is to measure the blood flow in the rat common carotid artery by using noninvasive phase contrast magnetic resonance imaging.

Fase contraste resonancia magnética en la arteria carótida común de rata

Phase contrast magnetic resonance imaging (PC-MRI) is a noninvasive approach that can quantify flow-related parameters such as blood flow. Previous ...

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing continuous remodeling with the competing activity of osteoblasts, which produce the new bone matrix, and osteoclasts, whose function is to eliminate mineralized bone. [18F]-NaF is a positron emission tomography (PET) radiotracer that enables visualization of bone metabolism. [18F]-NaF is chemically absorbed into hydroxyapatite in the bone matrix by osteoblasts and can thus noninvasively detect osteoblastic activity, which is occult to conventional imaging techniques. Kinetic modeling of dynamic [18F]-NaF-PET data provides detailed quantitative measures of bone metabolism. Conventional semi-quantitative PET data, which utilizes standardized uptake values (SUVs) as a measure of radiotracer activity, is referred to as a static technique due to its snapshot of tracer uptake in time.&#160; Kinetic modeling, however, utilizes dynamic image data where tracer levels are continuously acquired providing tracer uptake temporal resolution. From the kinetic modeling of dynamic data, quantitative values like blood flow and metabolic rate (i.e., potentially informative metrics of tracer dynamics) can be extracted, all with respect to the measured activity in the image data. When combined with dual modality PET-MRI, region-specific kinetic data can be correlated with anatomically registered high-resolution structural and pathologic information afforded by MRI. The goal of this methodological manuscript is to outline detailed techniques for performing and analyzing dynamic [18F]-NaF-PET-MRI data. The lumbar facet joint is a common site of degenerative arthritis disease and a common cause for axial low back pain.&#160; Recent studies suggest [18F]-NaF-PET may serve as a useful biomarker of painful facetogenic disease.&#160; The human lumbar facet joint will, therefore, be used as a prototypical region of interest for dynamic [18F]-NaF-PET-MRI analysis in this manuscript.

Quantitative [18F]-Naf-PET-MRI Analysis for the Evaluation of Dynamic Bone Turnover in a Patient with Facetogenic Low Back Pain

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. We present detailed methodologies for performing and analyzing dynamic [18F]-NaF-PET-MRI data in a patient with facetogenic low back pain using the lumbar facet joints as a prototypical region of interest.

Cuantitativo [18F]-Naf-PET-MRI Análisis para la evaluación de la rotación ósea dinámica en un paciente con dolor de espalda baja facetogénico

Imaging techniques that reflect dynamic bone turnover may aid in characterizing a wide range of bone pathologies. Bone is a dynamic tissue undergoing ...

Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of the fresh gas entering a lung region divided by the region&#8217;s end-expiratory volume &#8213; in the human lung, using only inhaled oxygen as a contrast agent. Regional quantification of specific ventilation has the potential to help identify areas of pathologic lung function. Oxygen in solution in tissue shortens the tissue&#8217;s longitudinal relaxation time (T1), and thus a change in tissue oxygenation can be detected as a change in T1-weighted signal with an inversion recovery acquired image. Following an abrupt change between two concentrations of inspired oxygen, the rate at which lung tissue within a voxel equilibrates to a new steady-state reflects the rate at which resident gas is being replaced by inhaled gas. This rate is determined by specific ventilation. To elicit this sudden change in oxygenation, subjects alternately breathe 20-breath blocks of air (21% oxygen) and 100% oxygen while in the MRI scanner. A stepwise change in inspired oxygen fraction is achieved through use of a custom three-dimensional (3D)-printed flow bypass system with a manual switch during a short end-expiratory breath hold. To detect the corresponding change in T1, a global inversion pulse followed by a single shot fast spin echo sequence was used to acquire two-dimensional T1-weighted images in a 1.5&#160;T MRI scanner, using an eight-element torso coil. Both single slice and multi-slice imaging are possible, with slightly different imaging parameters. Quantification of specific ventilation is achieved by correlating the time-course of signal intensity for each lung voxel with a library of simulated responses to the air/oxygen stimulus. SVI estimations of specific ventilation heterogeneity have been validated against multiple breath washout and proved to accurately determine the heterogeneity of the specific ventilation distribution.

Specific ventilation imaging is a functional magnetic resonance imaging technique that allows for quantification of regional specific ventilation in the human lung, using inhaled oxygen as a contrast agent. Here, we present a protocol to collect and analyze specific ventilation imaging data.

Mapeo cuantitativo de ventilación específica en el pulmón humano usando resonancia magnética de protones y oxígeno como agente de contraste

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of ...

Stabilized Longitudinal In Vivo Cellular-Level Visualization of the Pancreas in a Murine Model with a Pancreatic Intravital Imaging Window

Direct in vivo cellular-resolution imaging of the pancreas in a live small animal model has been technically challenging. A recent intravital imaging study, with an abdominal imaging window, enabled visualization of the cellular dynamics in abdominal organs in vivo. However, due to the soft sheet-like architecture of the mouse pancreas that can be easily influenced by physiologic movement (e.g., peristalsis and respiration), it was difficult to perform stabilized longitudinal in vivo imaging over several weeks at the cellular level to identify, track, and quantify islets or cancer cells in the mouse pancreas. Herein, we describe a method for implanting a novel supporting base, an integrated pancreatic intravital imaging window, that can spatially separate the pancreas from the bowel for longitudinal time-lapse intravital imaging of the pancreas microstructure. Longitudinal in vivo imaging with the imaging window enables stable visualization, allowing for the tracking of islets over a period of 3 weeks and high-resolution three-dimensional imaging of the microstructure, as evidenced here in an orthotopic pancreatic cancer model. With our method, further intravital imaging studies can elucidate the pathophysiology of various diseases involving the pancreas at the cellular level.

Stabilized Longitudinal In Vivo Cellular-Level Visualization of the Pancreas in a Murine Model with a Pancreatic Intravital Imaging Window

In vivo high-resolution imaging of the pancreas was facilitated with the pancreatic intravital imaging window.

Visualización longitudinal estabilizada a nivel celular in vivo del páncreas en un modelo murino con una ventana de imágenes intravitales pancreáticas

Direct in vivo cellular-resolution imaging of the pancreas in a live small animal model has been technically challenging. A recent intravital imaging ...