Apoyado por el NIH 1P01HL089407-01A1 (Lawrence, PI), Animal núcleo A, NIH 1 K01-01A2 HL080962 (Myers, PI).

1. Procedimientos de ratón anestesia <ol><li> Los animales son extraídas de su jaula y se colocan en una cámara de inducción de la anestesia antes de la operación para la inducción de gas en el 2% de isoflurano y oxígeno al 100%, con un caudal de 0,5 litros por minuto (vaporizador controlada). </li><li> Los ratones son sedados en la cámara de inducción de la anestesia, se retiran de la cámara y la parte ventral del abdomen se afeita con una maquinilla eléctrica, o mantenerse dentro de la cámara si es una crema depilatoria el cabello se utiliza (1 min). </li><li> Si bien todavía bajo sedación, se pesan, los ojos están lubricados con ungüento oftálmico estéril y, a continuación, coloca en recumbancy dorsal en un dispositivo de calentamiento de agua caliente que circula bajo anestesia general con un cono de la nariz con isoflurano y oxígeno. En este punto, la tasa de oxígeno se reduce a 0,2 litros por minuto. </li><li> El abdomen se rocía con una solución de clorhexidina (diacetato de clorhexidina es rápidamente bacterialcidal y persistente) y se limpió con una gasa estéril tres veces o hasta que el sitio quirúrgico está limpio. </li></ol> 2. Ratón Micro-quirúrgicos y procedimientos de recuperación <ol><li> Una incisión de línea media ventral (2 cm) se realiza con unas tijeras iris a través de la piel y la pared abdominal exponer el abdomen. Una solución salina estéril 2x2 empapado en una gasa se utiliza para reflejar los intestinos al lado izquierdo del animal. Una inmovilización del ratón se pone en la visualización lugar en que se de la vena cava inferior (VCI). </li><li> En este punto, el isoflurano se reduce a un nivel de mantenimiento del 2% y la tasa de oxígeno se mantiene en 0,2 litros por minuto para el resto de la intervención quirúrgica. </li><li> Disección roma se facilita con un hisopo aplicador estéril y extra pinzas delicadas medio del iris curva de tejidos. Se debe tener cuidado en la manipulación de los tejidos del ratón para que son extremadamente frágiles. </li><li> Todas las ramas laterales IVC, a partir de las venas renales hasta la bifurcación ilíaca, se ligan con sutura de prolene 7-0 no reactivo. Ramas de nuevo quedó patente. </li><li> En el modelo electrolítico IVC (EIM), un 25G aguja de acero inoxidable, unido a un cable de cobre recubierto de plata (KY-30-1-GRN, Electrospec, Dover, Nueva Jersey) se inserta en la vena cava inferior expuestos caudal, (Figura 1) y se coloca contra la pared anterior (ánodo). </li><li> Otro cable se implanta subcutáneamente completando el circuito (cátodo). </li><li> Una corriente de 250 μAmps más de 15 minutos se aplicó mediante un estimulador Grass S48 onda cuadrada y una unidad de corriente constante (Tecnologías de la hierba, un Astro-Med, Inc., West Warwick, RI). Los resultados directos actuales en la formación de productos tóxicos de la electrólisis que erosionan la superficie endotelial de la vena cava inferior la promoción de un ambiente trombogénico y posterior formación de trombos. </li><li> Después de 15 minutos, se retira la aguja y un hisopo de algodón se realiza con suavidad en contacto con el área para prevenir el sangrado </li><li> En los animales sham, se coloca la aguja en la vena cava inferior y luego se retira, sin la aplicación de la corriente. </li><li> El sitio de la laparotomía se cierra en forma de dos capas. Nuestro laboratorio utiliza Vicryl 5-0, una sutura sintética, en un patrón continuo para cerrar la pared abdominal. Pegamento pegamento de la piel se utiliza para cerrar la piel. No hay puntos de sutura externos para su eliminación. </li><li> Ratones después se recuperan en una jaula de ratones individuales, observado de cerca después de la operación (45 minutos a 2 horas), bajo una lámpara de calentamiento (distancia min 24 pulgadas de distancia de la jaula), y luego regresaron a sus viviendas originales. Medicamentos para el dolor y agentes anti-inflamatorios no se puede utilizar si no interfiere con el objetivo de este estudio. Justificación científica para suspender medicamentos para el dolor, veterinarios, y la aprobación ICUCA se necesitan. Nuestro laboratorio ha descubierto que la buprenorfina ,0.05-0 0,1 mg / kg vía subcutánea es un analgésico excelente pre-y post-operatorios para los ratones. Además, la lidocaína en 4mg/kg (0,4 ml / kg de una solución al 1%) puede ser infundida en el sitio de la incisión, cuando analgésicos sistémicos pueden confundir los resultados experimentales. </li><li> Por lo general no la experiencia post-operatorio efectos adversos debido a la trombosis venosa profunda. Sin embargo, los efectos adversos post-operatorio efectos pueden incluir la muerte espontánea de anestesia, la pérdida quirúrgica de sangre, y la parálisis parcial debido a un traumatismo del nervio. Los animales que son de lenta recuperación se puede alimentar la nutria o gel húmedo comida colocados en el suelo de la jaula para facilitar la recuperación del animal. Los animales con cortar las complicaciones postoperatorias deberían ser sacrificados evitando la eutanasia. </li><li> En el punto en el tiempo asignado, la eutanasia se lleva a cabo humanamente de acuerdo con las recomendaciones establecidas por la American Veterinary Medical Association Directrices sobre la eutanasia para los roedores. </li></ol> 3. Resultados representante La EIM es un modelo que se forma un trombo en la presencia de flujo continuo de sangre. Las siguientes figuras muestran los parámetros investigados en este nuevo modelo. <img src="/files/ftp_upload/2737/2737fig1.jpg" alt="Figura 1" /> Figura 1 definesthe área anatómica en donde un 25G de acero inoxidableaguja, conectada a un cable de cobre recubierto de plata (KY-30-1-GRN, Electrospec, Dover, Nueva Jersey) se inserta. Tenga en cuenta que un nodo linfático es casi presente y ayuda como punto de referencia para encontrar el caudal IVC. <img src="/files/ftp_upload/2737/2737fig2.jpg" alt="Figura 2" /> Figura 2: El peso del trombo 2 días después de la EIM en las diferentes cepas. Como era de esperar, el peso del trombo fue menor en el PAI-1 ratones KO y mayor en los ratones de hipercoagulabilidad Delta CT (CT ^). <img src="/files/ftp_upload/2737/2737fig3.jpg" alt="Figura 3" /> Figura 3: P-selectina soluble, un fabricante de trombosis venosa profunda, se midió en diferentes cepas. Los niveles más bajos se encontraron en el PAI-1, mientras que los ratones KO los niveles más altos se encontraron en ratones de hipercoagulabilidad delta CT. <img src="/files/ftp_upload/2737/2737fig4.jpg" alt="Figura 4" /> Figura 4 Correlación entre el peso del trombo y P-selectina soluble se encuentra en las diferentes cepas. Es de destacar que en el grupo que generó el menor tamaño del trombo, la P-selectina soluble detectada fue la más baja (PAI-1 ratones KO). En el grupo que generó el mayor tamaño del trombo, la P-selectina soluble detectada fue la más alta (hipercoagulabilidad CT delta). <img src="/files/ftp_upload/2737/2737fig5.jpg" alt="Figura 5" /> Figura 5: Con el fin de demostrar la presencia de flujo de la sangre, la ecografía se realizó en ratones sometidos a la EIM. Figura 5 se muestra la ecografía realizada en un ratón de 2 días después de la EIM. A continuación, la muestra fue la cosecha. Tenga en cuenta que la forma del trombo sugieren la formación de trombos en la presencia de flujo

<ol>
	<li>Diaz, J. A., Hawley, A. E., Alvarado, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thrombogenesis+with+continuous+blood+flow+in+the+inferior+vena+cava.+A+novel+mouse+model.">Thrombogenesis with continuous blood flow in the inferior vena cava. A novel mouse model.</a> Thromb Haemost. 104, 366-375 (2010).</li><li>Eitzman, D. T., Westrick, R. J., Nabel, E. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasminogen+activator+inhibitor-1+and+vitronectin+promote+vascular+thrombosis+in+mice.">Plasminogen activator inhibitor-1 and vitronectin promote vascular thrombosis in mice.</a> Blood. 95, 577-580 (2000).</li><li>Myers, D., Farris, D., Hawley, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selectins+influence+thrombosis+in+a+mouse+model+of+experimental+deep+venous+thrombosis.">Selectins influence thrombosis in a mouse model of experimental deep venous thrombosis.</a> J Surg Res. 108, 212-221 (2002).</li><li>Myers, D. D., Hawley, A. E., Farris, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=P-selectin+and+leukocyte+microparticles+are+associated+with+venous+thrombogenesis.">P-selectin and leukocyte microparticles are associated with venous thrombogenesis.</a> J Vasc Surg. 38, 1075-1089 (2003).</li><li>Pierangeli, S. S., Barker, J. H., Stikovac, D. <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+human+IgG+antiphospholipid+antibodies+on+an+in+vivo+thrombosis+model+in+mice.">Effect of human IgG antiphospholipid antibodies on an in vivo thrombosis model in mice.</a> Thromb Haemost. 71, 670-674 (1994).</li><li>Pierangeli, S. S., Liu, X. W., Barker, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+thrombosis+in+a+mouse+model+by+IgG,+IgM+and+IgA+immunoglobulins+from+patients+with+the+antiphospholipid+syndrome.">Induction of thrombosis in a mouse model by IgG, IgM and IgA immunoglobulins from patients with the antiphospholipid syndrome.</a> Thromb Haemost. 74, 1361-1367 (1995).</li></ol>

El ratón es una excelente herramienta de investigación para experimentos in vivo. Por lo tanto, el desarrollo de modelos de ratón que imitan las enfermedades o estados patológicos son necesarios. Varios modelos de ratón trombosis venosa se han utilizado para estudiar la TVP, incluyendo: fotoquímica (2), la estasis (3-4) y el trauma mecánico (5-6). Sin embargo, ninguno de estos modelos utilizan un estímulo endotelial interno para generar un trombo en la presencia de flujo continuo de sangre. La EIM, utilizando estímulos electrolítico en el IVC, promueve la trombogénesis venosa por activación endotelial en la presencia de flujo sanguíneo (1). Técnicamente es simple, fácilmente reproducible y tiene una alta tasa de supervivencia (99%). A pesar del hecho de que una corriente eléctrica se utiliza para crear la electrólisis, no se genera calor (1). El modelo simula EIM TVP clínica, y por lo tanto sirve como una herramienta valiosa para el estudio de los mecanismos intrínsecos de la formación de trombos y la resolución. El modelo de EIM es también útil para la promoción de nuevos enfoques terapéuticos contra la enfermedad trombosis.

<table border="1"><tbody><tr><th> Nombre del reactivo </th><th> Empresa </th><th> Número de catálogo </th><th> Comentarios (opcional) </th></tr><tr><td> DMEM </td><td> Invitrogen </td><td> ABCD1234 </td><td></td></tr></tbody></table>

electrolytic inferior vena cava model (eim) of venous thrombosis

Los modelos animales juegan un papel vital en la trombosis venosa profunda (TVP) de investigación para estudiar la formación de trombos resolución del trombo y para probar potenciales compuestos terapéuticos (1). Nuevos compuestos para ser utilizados en el tratamiento y prevención de la TVP se están desarrollando actualmente. La entrega de compuestos con potencial terapéutico para un antagonista de la vena trombosada afectados ha sido problemático. En el contexto de las aplicaciones terapéuticas, un modelo que utiliza parcial estasis y constantemente genera trombos dentro de una vena principal ha sido creado recientemente. El electrolítico de vena cava inferior del modelo (EIM) es el modelo de ratón de la trombosis venosa profunda, que permite la formación de trombos en la presencia de flujo continuo de sangre. Este modelo permite a los agentes terapéuticos para estar en contacto con el trombo de una forma dinámica, y es más sensible que otros modelos de trombosis venosa profunda (1). Además, este modelo de trombosis simula situaciones clínicas de la formación de trombos y es ideal para estudiar la activación de las células endoteliales venosas, la migración de leucocitos, la trombogénesis venosa, y para probar las aplicaciones terapéuticas (1). El modelo de EIM es técnicamente simple, fácilmente reproducible, consistente crea tamaños de trombos y permite una amplia muestra (es decir, los trombos y pared de la vena) que se requiere para fines de análisis.

Watch this Scientific Journal Video about Electrolytic Inferior Vena Cava Model EIM of Venous Thrombosis at JoVE.com

Electrolytic Inferior Vena Cava Model EIM of Venous Thrombosis

La inducción electrolítica de activación endotelial en la superficie interna de la vena cava inferior resultados en la formación de un trombo venoso tipo debido a la activación endotelial y parcial de la estasis sanguínea, dos componentes de la tríada de Virchow.

Electrolítico de la vena cava inferior del modelo (EIM) de la Trombosis Venosa

Animal models serve a vital role in deep venous thrombosis (DVT) research in order to study thrombus formation, thrombus resolution and to test potential ...

electrolytic-inferior-vena-cava-model-eim-of-venous-thrombosis

Research

JoVE Journal

Medicine

Electrolytic Inferior Vena Cava Model (EIM) of Venous Thrombosis

17.0K vistas.  University of Michigan. La inducción electrolítica de activación endotelial en la superficie interna de la vena cava inferior resultados en la formación de un trombo venoso tipo debido a la activación endotelial y parcial de la estasis sanguínea, dos componentes de la tríada de Virchow.

Video: Electrolytic Inferior Vena Cava Model EIM of Venous Thrombosis

Mouse Complete Stasis Model of Inferior Vena Cava Thrombosis

Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). In the United States (U.S.), the high morbidity and mortality rates make VTE a serious health concern 1-2. After heart disease and stroke, VTE is the third most common vascular disease 3. In the U.S. alone, there is an estimated 900,000 people affected each year, with 300,000 deaths occurring annually 3. A reliable in vivo animal model to study the mechanisms of this disease is necessary.
The advantages of using the mouse complete stasis model of inferior vena cava thrombosis are several. The mouse model allows for the administration of very small volumes of limited availability test agents, reducing costs dramatically. Most promising is the potential for mice with gene knockouts that allow specific inflammatory and coagulation factor functions to be delineated. Current molecular assays allow for the quantitation of vein wall, thrombus, whole blood, and plasma for assays. However, a major concern involving this model is the operative size constraints and the friability of the vessels. Also, due to the small IVC sample weight (mean 0.005 grams) it is necessary to increase animal numbers for accurate statistical analysis for tissue, thrombus, and blood assays such as real-time polymerase chain reaction (RT-PCR), western blot, enzyme-linked immunosorbent (ELISA), zymography, vein wall and thrombus cellular analysis, and whole blood and plasma assays 4-8.
The major disadvantage with the stasis model is that the lack of blood flow inhibits the maximal effect of administered systemic therapeutic agents on the thrombus and vein wall.

The mouse complete stasis model of inferior vena cava thrombosis yields quantifiable amounts of vein wall tissue and thrombus. It has proven useful for evaluating interactions between the vein wall and the occlusive thrombus and in assessing the progression from acute to chronic inflammation.

Ratón completo modelo de estasis Inferior Vena Cava trombosis

Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE).  In the United States (U.S.), the high morbidity and ...

Investigación

Medicina

Implantation of Inferior Vena Cava Interposition Graft in Mouse Model

Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are often used for reconstructive surgery to treat congenital cardiac anomalies. The long-term clinical results showed excellent patency rates, however, with significant incidence of stenosis. To investigate the cellular and molecular mechanisms of vascular neotissue formation and prevent stenosis development in tissue engineered vascular grafts (TEVGs), we developed a mouse model of the graft with approximately 1 mm internal diameter. First, the TEVGs were assembled from biodegradable tubular scaffolds fabricated from a polyglycolic acid nonwoven felt mesh coated with &#949;-caprolactone and L-lactide copolymer. The scaffolds were then placed in a lyophilizer, vacuumed for 24 hr, and stored in a desiccator until cell seeding. Second, bone marrow was collected from donor mice and mononuclear cells were isolated by density gradient centrifugation. Third, approximately one million cells were seeded on a scaffold and incubated O/N. Finally, the seeded scaffolds were then implanted as infrarenal vena cava interposition grafts in C57BL/6 mice. The implanted grafts demonstrated excellent patency (&#62;90%) without evidence of thromboembolic complications or aneurysmal formation. This murine model will aid us in understanding and quantifying the cellular and molecular mechanisms of neotissue formation in the TEVG.

To improve our knowledge of cellular and molecular neotissue formation, a murine model of the TEVG was recently developed. The grafts were implanted as infrarenal vena cava interposition grafts in C57BL/6 mice. This model achieves similar results to those achieved in our clinical investigation, but over a far shortened time-course.

Implantación de la vena cava inferior interposición del injerto en modelo de ratón

Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are often used for reconstructive surgery to treat congenital cardiac anomalies. ...

Ferric Chloride-induced Thrombosis Mouse Model on Carotid Artery and Mesentery Vessel

Severe thrombosis and its ischemic consequences such as myocardial infarction, pulmonary embolism and stroke are major worldwide health issues. The ferric chloride injury is now a well-established technique to rapidly and accurately induce the formation of thrombi in exposed veins or artery of small and large diameter. This model has played a key role in the study of the pathophysiology of thrombosis, in the discovery and validation of novel antithrombotic drugs and in the understanding of the mechanism of action of these new agents. Here, the implementation of this technique on a mesenteric vessel and carotid artery in mice is presented. The method describes how to label circulating leukocytes and platelets with a fluorescent dye and to observe, by intravital microscopy on the exposed mesentery, their accumulation at the injured vessel wall which leads to the formation of a thrombus. On the carotid artery, the occlusion caused by the clot formation is measured by monitoring the blood flow with a Doppler probe.

The FeCl3 induced thrombosis model in mice is described herein. A method to monitor thrombus growth by intravital microscopy observation on a mesenteric vessel and by blood flow measurement in the carotid artery is presented.

Trombosis modelo de ratón de la arteria carótida y Mesenterio Embarcaciones inducida por cloruro férrico-

Severe thrombosis and its ischemic consequences such as myocardial infarction, pulmonary embolism and stroke are major worldwide health issues. The ferric ...

Patch Angioplasty in the Rat Aorta or Inferior Vena Cava

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, we developed a rat model of patch angioplasty that can be used in either a vein or an artery, creating a patch venoplasty or a patch arterioplasty, respectively. Technical aspects of this model are discussed. The infra-renal IVC or aorta are dissected and then clamped proximally and distally. A 3 mm venotomy or arteriotomy is performed in the infrarenal inferior vena cava or aorta of 6 to 8 week-old Wistar rats. A bovine pericardial patch (3 mm x 1.5 mm x 0.6 mm) is then used to close the site using a 10-0 nylon suture. Compared to arterial patches, venous patches show increased neointimal thickness on postoperative day 7. This novel model of pericardial patch angioplasty can be used to examine neointimal hyperplasia on vascular biomaterials, as well as to compare the differences between the arterial and venous environments.

We have established a model of pericardial patch angioplasty that can be used in either small-diameter veins or arteries. This model can be used to compare venous and arterial neointimal hyperplasia formation.

Parche angioplastia en la aorta de rata o de la vena cava inferior

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, ...

A Rat Model of Orthotopic Liver Transplantation Using a Novel Magnetic Anastomosis Technique for Suprahepatic Vena Cava Reconstruction

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep learning curve. The introduction of the cuff technique for anastomosis of the portal vein (PV) and infrahepatic vena cava (IHVC) has significantly simplified the transplant procedure in rats. However, due to the short anterior wall of the recipients' suprahepatic vena cava (SHVC), the cuff technique is very difficult to use for the reconstruction of the SHVC. Most researchers in this field still use the hand-suture technique for SHVC reconstruction, which makes it the bottleneck step in rat orthotopic liver transplantation. The magnetic anastomosis technique (i.e., magnamosis) is a method of connecting two vessels using the attractive force between two magnets. Our recent study has shown that the magnetic anastomosis technique is superior to the hand-suture technique for SHVC reconstruction in rats. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using the novel magnetic anastomosis technique. In this model, the reconstruction of the PV and IHVC was performed by the standard cuff technique, while the reconstruction of the bile duct (BD) was performed by a stent technique. The hepatic re-arterialization was not performed. The magnetic anastomosis technique made SHVC reconstruction much easier and significantly shortened the anphepatic phase. After a reasonable learning curve, even researchers without advanced microsurgical skills can produce reliable and reproducible results using this rat model of OLT.

The reconstruction of the suprahepatic vena cava (SHVC) remains a difficult step in rat orthotopic liver transplantation. In this article, we show a step-by-step protocol for SHVC reconstruction in rats using a novel magnetic anastomosis technique.

Un modelo de rata de Orthotopic trasplante del hígado usando una técnica de Anastomosis magnética novela para la reconstrucción de la Vena Cava suprahepática

The rat model of orthotopic liver transplantation (OLT) is essential for transplant research. It is a very sophisticated animal model and requires a steep ...

Ferric Chloride-induced Canine Carotid Artery Thrombosis: A Large Animal Model of Vascular Injury

Occlusive arterial thrombosis leading to cerebral ischemic stroke and myocardial infarction contributes to ~13 million deaths every year globally. Here, we have translated a vascular injury model from a small animal into a large animal (canine), with slight modifications that can be used for pre-clinical screening of prophylactic and thrombolytic agents. In addition to the surgical methods, the modified protocol describes the step-by-step methods to assess carotid artery canalization by angiography, detailed instructions to process both the brain and carotid artery for histological analysis to verify carotid canalization and cerebral hemorrhage, and specific parameters to complete an assessment of downstream thromboembolic events by utilizing magnetic resonance imaging (MRI). In addition, specific procedural changes from the previously well-established small animal model necessary to translate into a large animal (canine) vascular injury are discussed.

Here, we present the modifications necessary to a well characterized and commonly used small animal ferric chloride-induced (FeCl3) carotid artery injury model for use in a large animal vascular injury model. The resulting model can be utilized for pre-clinical trial assessment of both prophylactic and thrombolytic pharmacological and mechanical interventions.

Trombosis de la arteria carótida canina cloruro férrico-inducida: Un modelo Animal grande de lesión Vascular

Occlusive arterial thrombosis leading to cerebral ischemic stroke and myocardial infarction contributes to ~13 million deaths every year globally. Here, ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

Medición de la contractilidad isométrica de la arteria mesentérica de ratón con cable miografía

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Murine Model of Central Venous Stenosis using Aortocaval Fistula with an Outflow Stenosis

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ligation of the inferior vena cava (IVC) in the outflow of the fistula, mimicking central venous stenosis. Technical aspects of this model are introduced. The aorta and IVC are exposed, following an abdominal incision. The infra-renal aorta and IVC are dissected for proximal clamping, and the distal aorta is exposed for puncture. The IVC at the midpoint between the left renal vein and the aortic bifurcation is carefully dissected to place an 8-0 suture beneath the IVC. After clamping the aorta and IVC, an AVF is created by puncturing the infra-renal aorta through both walls into the IVC with a 25 G needle, followed by ligating a 22 G intra-venous (IV) catheter and IVC together. The catheter is then removed, creating a reproducible venous stenosis without occlusion. The aorta and IVC are unclamped after confirming primary hemostasis. This novel model of central vein stenosis is easy to perform, reproducible, and will facilitate studies on AVF failure.

An aortocaval fistula was created by puncturing the murine infra-renal aorta through both walls into the inferior vena cava and was followed by creation of a stenosis in its outflow via partial ligation of the inferior vena cava. This reproducible model can be used to study central venous stenosis.

Modelo murino de estenosis venosa central usando fístula aortocaval con una estenosis de salida

Central venous stenosis is an important entity contributing to arteriovenous fistula (AVF) failure. A murine AVF model was modified to create a partial ...

Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava

Over the past several decades, clinicians have incorporated several applications of diagnostic point-of-care ultrasound (POCUS) into medical decision-making. Among the applications of POCUS, imaging the inferior vena cava (IVC) is practiced by a wide variety of specialties, such as nephrology, emergency medicine, internal medicine, critical care, anesthesiology, pulmonology, and cardiology. Although each specialty uses IVC data in slightly different ways, most medical specialties, at minimum, attempt to use IVC data to make predictions about intravascular volume status. While the relationship between IVC sonographic data and intravascular volume status is complex and highly context-dependent, all clinicians should collect the sonographic data in standardized ways to ensure repeatability. This paper describes standardized IVC image acquisition including patient positioning, transducer selection, probe placement, image optimization, and the pitfalls and limitations of IVC sonographic imaging.&#160;This paper also describes the commonly performed anterior IVC long-axis view and three other views of the IVC that can each provide helpful diagnostic information when the anterior long-axis view is difficult to obtain or interpret.

Point-of-care ultrasound evaluation of the inferior vena cava (IVC) is commonly utilized to identify, among other things, the volume status. Imaging should be performed systematically to ensure repeatability. This manuscript reviews the methods and pitfalls of sonographic IVC examination.

Método de adquisición de imágenes para la evaluación ecográfica de la vena cava inferior

Over the past several decades, clinicians have incorporated several applications of diagnostic point-of-care ultrasound (POCUS) into medical ...

Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening sequelae. While whole leg compression ultrasound with color and spectral Doppler is commonly performed in radiology and vascular labs, point-of-care ultrasound (POCUS) is becoming more common in the acute care setting. Providers appropriately trained in focused POCUS can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. This paper describes a simplified yet validated approach to POCUS by describing a three-zone protocol for lower extremity DVT POCUS image acquisition. The protocol explains the steps in obtaining vascular images at six compression points in the lower extremity. Beginning at the level of the proximal thigh and moving distally to the popliteal space, the protocol guides the user through each of the compression points in a stepwise manner: from the common femoral vein to the femoral and deep femoral vein bifurcation, and, finally, to the popliteal vein. Further, a visual aid is provided that may assist providers during real-time image acquisition. The goal in presenting this protocol is to help make proximal lower extremity DVT exams more accessible and efficient for POCUS users at the patient&#39;s bedside.

Traditionally, lower extremity deep venous thrombosis (DVT) is diagnosed by radiology-performed venous duplex ultrasound. Providers appropriately trained in focused point-of-care ultrasound (POCUS) can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. We describe the scanning technique for focused POCUS DVT lower extremity examination.

Ecografía en el punto de atención para trombosis venosa profunda proximal de las extremidades inferiores

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening ...