Name: electrolytic inferior vena cava model (eim) of venous thrombosis
Uploaded: 2011-07-12T13:00:00
Duration: 6 min 3 s
Description: Watch this Scientific Journal Video about Electrolytic Inferior Vena Cava Model EIM of Venous Thrombosis at JoVE.com

Suportado pelo NIH 1P01HL089407-01A1 (Lawrence, PI), Core animal A, 1 NIH K01 HL080962-01A2 (Myers, PI).

1. Anestesia Procedimentos do mouse <ol><li> Os animais são removidos de suas gaiolas e colocados em uma câmara de indução anestésica pré-operatória para a indução de gás em isoflurano a 2% e 100% de oxigênio a uma vazão de 0,5 litros por minuto (vaporizador controlada). </li><li> Os ratos são sedados na câmara de indução anestésica, removido da câmara e do abdômen ventral é raspada com tosquiadeiras elétricas, ou mantidos dentro da câmara se um creme depilatório cabelo é usado (1 min). </li><li> Enquanto ainda sob sedação, eles são pesados, os olhos são lubrificados com pomada oftálmica estéril e, em seguida, colocado em recumbancy dorsal em um dispositivo de aquecimento de água quente circulando sob anestesia geral com um cone de nariz usando isoflurano e oxigênio. Neste ponto, a taxa de oxigênio é reduzida para 0,2 litros por minuto. </li><li> O abdômen é pulverizado com solução de clorexidina (diacetato de clorexidina é rapidamente bacterialcidal e persistente) e limpo com gaze estéril ou até três vezes o local da cirurgia está limpo. </li></ol> 2. Rato Micro-cirúrgico e procedimentos de recuperação <ol><li> A incisão mediana ventral (2 cm) é feita com tesoura de íris através da pele e parede abdominal expondo o abdome. Um 2x2 salina estéril embebido em gaze é usada para refletir os intestinos para o lado esquerdo do animal. Um limitador do mouse é colocado no lugar permitindo a visualização da veia cava inferior (VCI). </li><li> Neste ponto, o isoflurano é reduzida a um nível de manutenção de 2% ea taxa de oxigênio permanece em 0,2 litros por minuto para o restante do procedimento cirúrgico. </li><li> Dissecção romba é facilitada utilizando um cotonete aplicador estéril e extra delicadas meia íris pinça curva. Cuidados devem ser tomados no manuseio do mouse para tecidos que são extremamente frágeis. </li><li> Todos os ramos laterais IVC, a partir das veias renais até a bifurcação ilíaca, estão ligados com 7-0 suturas não-reativo prolene. Ramos volta permaneceu patente. </li><li> No eletrolítico IVC modelo (EIM), uma agulha de aço inoxidável 25G, conectado a um fio de cobre revestido de prata (KY-30-1-GRN, Electrospec, Dover, NJ) é inserido na exposição caudal da VCI (Figura 1) e posicionado contra a parede anterior (ânodo). </li><li> Outro fio é implantado por via subcutânea completando o circuito (cátodo). </li><li> Uma corrente de 250 μAmps mais de 15 minutos foi aplicado utilizando um estimulador Grass S48 onda quadrada e uma unidade de corrente constante (Tecnologias Grass, Um Astro-Med, Inc., West Warwick, RI). Os resultados de corrente direta na formação de produtos tóxicos de eletrólise que corroem a superfície endotelial do IVC promoção de um ambiente trombogênico e formação de trombos subseqüentes. </li><li> Após 15 minutos, a agulha é removida e um chumaço de algodão é realizada suavemente em contato com a área para prevenir hemorragias </li><li> Em animais sham, a agulha é colocada na VCI e depois removido, sem aplicação da corrente. </li><li> O site laparotomia é fechada em uma forma de duas camadas. Nosso laboratório emprega vicryl 5-0, uma sutura sintética, em um padrão contínuo para fechar a parede abdominal. Cola adesivo de pele é usado para fechar a pele. Não há suturas externas para remoção. </li><li> Ratos são então recuperados em uma gaiola de rato individual, observado de perto no pós-operatório (45 minutos a 2 horas), sob uma lâmpada de aquecimento (min distância 24 centímetros de distância da gaiola), em seguida, voltaram para suas unidades habitacionais original. Medicação para dor e anti-inflamatórios podem ser usados ​​se não interferir com o objetivo do estudo. Justificação científica de reter medicamentos para a dor, veterinária, e aprovação ICUCA são necessários. Nosso laboratório descobriu que a buprenorfina ,0.05-0 0,1 mg / kg ² é um analgésico excelente pré-e pós-operatório para os ratos. Além disso, Lidocaína a 4mg/kg (0,4 ml / kg de uma solução a 1%) pode ser infundida no local da incisão, quando analgésicos sistêmicos possam confundir os resultados experimentais. </li><li> Nós normalmente não experiência pós-operatório efeitos adversos devido à TVP. No entanto, adversos pós-operatório pode incluir efeitos anestésicos morte espontânea, perda de sangue cirúrgico, e paresia parcial devido ao trauma do nervo. Animais que são lentas para se recuperar pode ser alimentado nutria gel ou ter ração úmida colocada no chão da gaiola para facilitar a recuperação do animal. Animais com sever complicações pós-operatórias devem ser humanamente eutanasiados. </li><li> No ponto de tempo determinado, a eutanásia é realizada de forma humana, em conformidade com as recomendações estabelecidas pela American Veterinary Medical Association orientações sobre a eutanásia para roedores. </li></ol> 3. Resultados representante O EIM é um modelo que formas trombo na presença de fluxo de sangue contínuo. As figuras abaixo mostram os parâmetros investigados neste novo modelo. <img src="/files/ftp_upload/2737/2737fig1.jpg" alt="Figura 1" /> Figura 1 definesthe área anatômica onde uma 25G de aço inoxidávelagulha, conectada a um fio de cobre revestido de prata (KY-30-1-GRN, Electrospec, Dover, NJ) é inserido. Note que um nó linfático é quase presente e ajuda como um marco para encontrar o IVC caudal. <img src="/files/ftp_upload/2737/2737fig2.jpg" alt="Figura 2" /> Figura 2: peso do trombo 2 dias após EIM em diferentes linhagens. Como esperado, o peso do trombo foi menor no PAI-1 camundongos KO e maiores em hipercoagulabilidade Delta CT camundongos (^ CT). <img src="/files/ftp_upload/2737/2737fig3.jpg" alt="Figura 3" /> Figura 3: P-selectina solúvel, um fabricante de trombose venosa profunda, foi medida em diferentes linhagens. Os níveis mais baixos foram encontrados em PAI-1 camundongos KO enquanto os níveis mais altos foram encontrados em ratos de hipercoagulabilidade delta CT. <img src="/files/ftp_upload/2737/2737fig4.jpg" alt="Figura 4" /> Figura 4 Correlação entre o peso do trombo e P-selectina solúvel foi encontrado em diferentes linhagens. De nota, no grupo que gerou o menor tamanho do trombo, a P-selectina solúvel detectado foi a mais baixa (PAI-1 camundongos KO). No grupo que gerou o maior tamanho do trombo, a P-selectina solúvel detectado foi o maior (hipercoagulabilidade delta CT). <img src="/files/ftp_upload/2737/2737fig5.jpg" alt="Figura 5" /> Figura 5: A fim de demonstrar a presença do fluxo de sangue, ultra-sonografia foi realizada em ratos submetidos a EIM. A Figura 5 mostra o ultra-som realizado em um rato de 2 dias após EIM. Em seguida, o espécime foi colheita. Observe o que a forma trombo sugerem a formação de trombos na presença de fluxo

<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>

Não há conflitos de interesse declarados.

O mouse é uma ferramenta excelente para pesquisa em experimentos in vivo. Assim, o desenvolvimento de modelos de mouse que simulam doenças ou condições patológicas são necessárias. Diversos modelos de mouse trombose venosa têm sido usados ​​para estudar a TVP, incluindo: fotoquímica (2), estase (3-4) e trauma mecânico (5-6). No entanto, nenhum destes modelos utilizam um estímulo interno endoteliais para gerar trombo na presença de fluxo de sangue contínuo. A EIM, a partir de estímulo eletrolítica dentro do IVC, promove trombogênese venosa pela ativação endotelial na presença de fluxo sanguíneo (1). É tecnicamente simples, facilmente reprodutível e tem uma elevada taxa de sobrevivência (99%). Apesar do fato de que uma corrente elétrica é usado para criar a eletrólise, o calor não é gerado (1). O modelo simula EIM TVP clínicos e, portanto, serve como uma ferramenta valiosa para estudar os mecanismos intrínsecos de formação de trombos e resolução. O modelo de EIM também é útil para o avanço de novas abordagens terapêuticas contra a doença trombose.

<table border="1"><tbody><tr><th> Nome do reagente </th><th> Companhia </th><th> Número de catálogo </th><th> Comentários (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

Modelos animais desempenham um papel vital na pesquisa trombose venosa profunda (TVP), a fim de estudar a formação de trombo resolução, trombo e para testar potenciais compostos terapêuticos (1). Novos compostos para serem utilizados no tratamento e prevenção de TVP estão sendo desenvolvidos atualmente. A entrega do potencial antagonista de compostos terapêuticos para uma veia afetada thrombosed tem sido problemática. No contexto de aplicações terapêuticas, um modelo que usa parcial estase e consistente gera trombos dentro de uma veia importante foi recentemente estabelecida. O Eletrolítico veia cava inferior Model (EIM) é o modelo do rato de TVP que permite a formação de trombos na presença de fluxo de sangue contínuo. Este modelo permite que os agentes terapêuticos para estar em contato com o trombo de forma dinâmica, e é mais sensível do que outros modelos de TVP (1). Além disso, este modelo de trombose simula situações clínicas de formação de trombos e é ideal para estudar venosa ativação da célula endotelial, migração de leucócitos, trombogênese venosa, e para testar aplicações terapêuticas (1). O modelo de EIM é tecnicamente simples, facilmente reprodutível, cria tamanhos consistentes trombos e permite uma grande amostra (ie trombo e parede da veia) que é necessário para fins analíticos.

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

A indução eletrolítico de ativação endotelial na superfície interna da Vena Cava Inferior resultados na formação venosa tipo trombo devido à ativação endotelial e parciais a estagnação do sangue, dois componentes da tríade de Virchow.

Eletrolítico Veia Cava Inferior Model (EIM) de trombose 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

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.

Modelo do mouse completa de Stasis Inferior Trombose da veia cava

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

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.

Implantação de Veia Cava Inferior interposição de enxerto no Rato Modelo

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.

Férrico Thrombosis Modelo rato na artéria carótida e Mesentery Vessel induzida por Chloride

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.

Remendar Angioplastia na Rat aorta ou veia 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.

Um modelo do rato de ortotópico transplante hepático, usando uma técnica de anastomose magnético romance para reconstrução de veia Cava Suprahepatic

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.

Trombose da artéria carótida canino induzida por cloreto férrico: Um modelo Animal grande de lesão 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.

Medição de contratilidade isométrica da artéria mesentérica Mouse usando fio miografia

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 estenose venosa central usando fístula Aortocaval com estenose de saída

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 aquisição de imagens para avaliação ultrassonográfica da veia 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.

Triagem ultrassonográfica no local de atendimento para trombose venosa profunda proximal dos membros inferiores

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