Este trabajo fue apoyado por una beca de los Institutos Nacionales de Salud, R01CA142928.

1. La inyección intravenosa de azul de Evans en la vena lateral de la cola de ratones <ol><li> Preparar una solución de 0,5% estéril de azul de Evans en PBS. Si es necesario, filtro-esterilizar la solución para eliminar cualquier material particulado que no se ha disuelto. </li><li> Aspirar 200 l Evans solución azul en una jeringa. Evitar todas las burbujas de aire que podrían haber escapado a la jeringa. </li><li> Coloque los ratones que son 8-12 semanas de edad en un dispositivo de retención para que el animal no es libremente móvil, pero la cola puede ser manejado. </li><li> Coloque el dispositivo de sujeción del ratón sobre su lado para que la vena lateral de la cola es fácilmente visible y están mirando hacia arriba. </li><li> Apóyese en la cola con la mano no dominante entre el pulgar y el índice. </li><li> Insertar la aguja (calibre pequeño, 27-30) en un avance 10-15 grados de ángulo, bisel hacia arriba, en la vena lateral de la cola hacia la dirección de la cabeza. Mantener la aguja y la jeringa paralela a la cola. </li><li> Do No se aplica la presión de retorno para confirmar la colocación adecuada, ya que podría colapsar la vena. </li><li> Inyecte lentamente 200 l solución Evans Blue en la vena de la cola del ratón. </li><li> Observar la facilidad con la que avanza el émbolo, ya que esta es la prueba de la colocación correcta de la aguja en la vena. </li><li> Ponga el ratón de nuevo en su jaula y observarla durante 30 min. </li></ol> 2. Colección de órganos y extracción de Evans Blue de los Órganos <ol><li> El sacrificio de los ratones mediante dislocación cervical. Para fines de ensayo Miles dislocación cervical se recomienda ya que limita la interferencia significativa con la permeabilidad vascular. Sacrificar todos los ratones al mismo tiempo, tan rápido como sea posible. Trabaja con cohortes de 6 ratones o menos, porque poco después de la muerte vasos sanguíneos se vuelven más permeables. </li><li> Coloque los ratones en sus espaldas y ponen sus pies sobre una superficie blanca. </li><li> Abra la cavidad abdominal y torácica para exponer thorACIC y órganos abdominales. </li><li> Tome fotografías representativas para mostrar las diferencias en Evans extravasación de azul. Incluyen todos los ratones en el mismo campo con el fin de tener idénticas condiciones de iluminación para todos los ratones. </li><li> Recoge los órganos de interés y los puso en tubos de 1,5 ml </li><li> Pesar un tubo vacío y llevar el valor del balance a cero. </li><li> Transferir la muestra de tejido y ponderar la misma. Repita para todas las muestras de tejido. Los tejidos pueden ser secadas al aire para eliminar la variabilidad del contenido de agua entre los diferentes órganos. </li><li> . Añadir 500 l de formamida a cada tubo de muestra de tejido. </li><li> Transferir todos los tubos a un baño de agua a 55 ° C o bloque de calor. Incubar durante 24-48 horas para extraer tejido de azul de Evans. </li></ol> 3. La cuantificación de azul de Evans extravasado en el tejido intersticial <ol><li> Centrifugar la formamida / mezcla de azul de Evans para sedimentar los fragmentos de tejidos restantes. </li><li> Medir la absorbancia a 610nm. Utilizar 500 l formamida como blanco. </li><li> Calcular ng azul de Evans extravasado por mg de tejido. </li><li> Trazar todos los datos en un gráfico. </li><li> Realizar análisis estadístico para determinar diferencias significativas. </li></ol>

<ol>
	<li>Beck, K. F., 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=Inducible+NO+synthase:+role+in+cellular+signaling.">Inducible NO synthase: role in cellular signaling.</a> J. Exp. Biol. 202, 645-653 (1999).</li><li>Bertglia, S., Giusti, 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+nitric+oxide+in+capillary+perfusion+and+oxygen+delivery+regulation+during+systemic+hypoxia.">Role of nitric oxide in capillary perfusion and oxygen delivery regulation during systemic hypoxia.</a> Am. J. Physiol. Heart Circ. Physiol. 288, H525-H531 (2005).</li><li>Miles, A. A., Miles, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+reactions+to+histamine,+histamine-liberator+and+leutaxine+in+the+skin+of+guinea+pigs.">Vascular reactions to histamine, histamine-liberator and leutaxine in the skin of guinea pigs.</a> J. Physiol. (London). 118, 228-257 (1952).</li><li>Weis, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+permeability+in+cardiovascular+disease+and+cancer.">Vascular permeability in cardiovascular disease and cancer.</a> Curr. Opin. Hematol. 15, 243-249 (2008).</li><li>Kumar, P., Shen, Q., Pivetii, C. D., Lee, E. S., We, M. H., Yuan, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+mechanisms+of+endothelial+hyperpermeability:+implications+in+inflammation.">Molecular mechanisms of endothelial hyperpermeability: implications in inflammation.</a> Expert Rev. Mol. Med. 30, 11-19 (2009).</li><li>Viazzi, F., 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=Vascular+permeability,+blood+pressure,+and+organ+damage+in+primary+hypertension.">Vascular permeability, blood pressure, and organ damage in primary hypertension.</a> Hypertens. Res. 31, 873-879 (2008).</li><li>Scheppke, ., 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=Retinal+vascular+permeability+suppression+by+topical+application+of+a+novel+VEGFR2/Src+kinase+inhibitor+in+mice+and+rabbits.">Retinal vascular permeability suppression by topical application of a novel VEGFR2/Src kinase inhibitor in mice and rabbits.</a> J. Clin. Invest. 118, 2337-2346 (2008).</li><li>Blanchet, M. 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=Loss+of+CD34+Leads+To+Exacerbated+Autoimmune+Arthritis+through+Increased+Vascular+Permeability.">Loss of CD34 Leads To Exacerbated Autoimmune Arthritis through Increased Vascular Permeability.</a> J. Immunol. 184, 1292-1299 (2010).</li><li>Dvorak, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mast+cell-derived+mediators+of+enhanced+microvascular+permeability,+vascular+permeability+factor/vascular+endothelial+growth+factor,+histamine,+and+serotonin,+cause+leakage+of+macromolecules+through+a+new+endothelial+cell+permeability+organelle,+the+vesiculo-vacuolar+organelle.">Mast cell-derived mediators of enhanced microvascular permeability, vascular permeability factor/vascular endothelial growth factor, histamine, and serotonin, cause leakage of macromolecules through a new endothelial cell permeability organelle, the vesiculo-vacuolar organelle.</a> Chem. Immunol. Allergy. 85, 185-204 (2005).</li><li>Le Guelte, A., Gavard, J. <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+endothelial+cell-cell+junctions+in+endothelial+permeability.">Role of endothelial cell-cell junctions in endothelial permeability.</a> Methods Mol. Biol. 763, 265-279 (2011).</li><li>Martins-Green, M., Petreaca, M., Yao, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+assay+system+for+in+vitro+detection+of+permeability+in+human+"endothelium".">An assay system for in vitro detection of permeability in human "endothelium".</a> Methods Enzymol. 443, 137-153 (2008).</li></ol>

Los autores no tienen conflicto o competencia de los intereses financieros.

La permeabilidad vascular es un marcador crítico para el estado de los vasos sanguíneos. Aumento de la permeabilidad vascular se ha demostrado que está presente en varias enfermedades sistémicas, incluyendo la diabetes, la hipertensión y las enfermedades autoinmunes 6,7,8. Aumento de la permeabilidad vascular ha demostrado ser mediada por esfuerzo cortante, factores de crecimiento tales como el factor de crecimiento endotelial vascular y el factor de crecimiento de fibroblastos, mediadores de la inflamac...

Formación y mantenimiento de barreras permeables selectivas son esenciales para el desarrollo adecuado de los órganos y 1,2 rendimiento. Las células endoteliales recubren el lumen del vaso sanguíneo y forman una barrera semi-permeable que es esencial en el transporte selectivo entre la sangre y el espacio intersticial de todos los órganos. Una barrera de permeabilidad adecuada se mantiene a través de estrechos célula a célula uniones que están estrictamente controladas por factores de crecimiento, citoquinas y otras moléculas relacionadas con el estrés 3. La interrupción de la barrera de células endoteliales puede resultar en aumento de la permeabilidad vascular y las fugas. Estos efectos se observan en diversos estados de enfermedad y la comprensión de la señalización molecular subrayado requiere métodos multidisciplinarios 4,5. En este artículo, se describe un método in vivo para medir la permeabilidad de los vasos utilizando un modelo de ratón. El ensayo que se describe, también conocido como ensayo de Miles, es un bien establISHED método para probar la permeabilidad vascular in vivo. El ensayo se basa en el hecho de que, bajo condiciones fisiológicas basales, la albúmina no cruza la barrera endotelial. Evans Blue, un colorante azoico con alta afinidad para la albúmina, se inyecta en la corriente sanguínea de un animal experimental, y bajo condiciones fisiológicas, se espera a ser restringido dentro de los vasos sanguíneos. Cuando un estímulo permeabilidad vascular se añade, ya sea tópica o sistémica, los vasos sanguíneos comienzan a gotear proteína y, por tanto, también el azul de Evans que se une a la albúmina. Esto resulta en una coloración azulada rápida de los tejidos que tienen vasos permeables. Inyección exitosa del colorante en la vena lateral de la cola del ratón es crítica para el buen resultado del experimento. Vena de la cola técnica de inyección requiere una amplia práctica y debe ser dominado antes de iniciar el experimento. Permeabilidad de los vasos es altamente dependiente de la edad y el peso de la unaimal, por lo que cuando se comparan diferentes cepas de ratón, es imperativo que los ratones u otros sujetos de prueba tienen cerca de las fechas de nacimiento y el peso idénticas. Otros factores que influyen en la permeabilidad de la barrera endotelial son las condiciones ambientales tales como temperatura, humedad, y muy importante, el estrés del manejo del ratón. Debido a la multitud de factores que pueden influir en el resultado del experimento es siempre aconsejable que el experimento se repitió al menos tres veces y el análisis estadístico realizado. Este ensayo puede ser utilizado para comparar o permeabilidad de los vasos de ratones que han sido modificadas genéticamente, así como los ratones con diferentes fondos genéticos. La permeabilidad puede ser evaluada en presencia o ausencia de un estímulo, dependiendo de la función del gen que se modula. Este ensayo también se puede usar o para probar el efecto de diferentes compuestos sobre la permeabilidad de los vasos.

<table border="1"><tbody><tr><td></td><td></td><td></td><td> REACTIVO </td></tr><tr><td> EVANS BLUE </td><td> SIGMA </td><td> E2129 </td><td></td></tr><tr><td> FORMAMIDA </td><td> INVITROGEN </td><td> 15515-026 </td><td></td></tr><tr><td> PBS </td><td></td><td></td><td> Fosfato 0,2 M 1,5 M NaCl pH 7,4 </td></tr><tr><td></td><td></td><td></td><td> EQUIPO </td></tr><tr><td> ESPECTROFOTÓMETRO </td><td> EPPENDORF </td><td> 952000006 </td><td></td></tr><tr><td> RATÓN dispositivo de sujeción </td><td> Harvard Apparatus </td><td> 340012 </td><td></td></tr><tr><td> JERINGA </td><td> BD </td><td> 309659 </td><td></td></tr><tr><td> AGUJAS </td><td> BD </td><td> 305106 </td><td> El calibre de la aguja depende del tamaño del animal. </td></tr><tr><td> BALANCE </td><td> DENVER INSTRUMENT </td><td> TP-64 </td><td></td></tr></tbody></table>

an in vivo assay to test blood vessel permeability

Este método se basa en la inyección intravenosa de azul de Evans en ratones como modelo animal de ensayo. El azul de Evans es un colorante que se une a la albúmina. En condiciones fisiológicas el endotelio es impermeable a la albúmina, por lo azul de Evans albúmina permanece unido restringidos dentro de los vasos sanguíneos. En condiciones patológicas que promueven el aumento de la permeabilidad células endoteliales vasculares pierden parcialmente sus contactos estrechos y el endotelio se vuelve permeable a pequeñas proteínas tales como albúmina. Esta condición permite la extravasación de azul de Evans en los tejidos. Un endotelio sano previene la extravasación del colorante en los tejidos vascularizados vecinos. Los órganos con aumento de la permeabilidad mostrará coloración azul aumentó significativamente en comparación con los órganos con endotelio intacto. El nivel de permeabilidad vascular se puede evaluar por simple visualización o por medición cuantitativa del colorante incorporado por miligramo de tejido de control versus animal experimental / tejido. Dos Powerful aspectos de este ensayo son su simplicidad y características cuantitativas. Colorante azul de Evans se puede extraer de los tejidos mediante la incubación de una cantidad específica de tejido en formamida. Evans Blue es el máximo de absorción a 620 nm y la absorbancia es mínimo a 740 nm. Mediante el uso de una curva estándar para el azul de Evans, medidas de densidad óptica se puede convertir en colorante capturado miligramo por miligramo de tejido. El análisis estadístico se debe utilizar para evaluar las diferencias significativas en la permeabilidad vascular.

Hemos utilizado un ensayo de permeabilidad in vivo para probar las fugas buque en ratones 8-12 semanas de edad. Esta prueba es útil para comparar la permeabilidad relativa vascular entre los animales del fondo genético diferente o en una sola cepa de ratones sometidos a tratamientos que afectan a la vasculatura. Nuestros resultados muestran que una cepa de ratones genéticamente modificados que hemos creado en nuestro laboratorio cuenta con un endotelio más permeable en comparación con ratones de t...

Watch this Scientific Journal Video about An in vivo Assay to Test Blood Vessel Permeability at JoVE.com

An in vivo Assay to Test Blood Vessel Permeability

Estamos presentando un<em&gt; In vivo</em&gt; Ensayo para probar la permeabilidad de los vasos sanguíneos. Este ensayo se basa en la inyección intravenosa de un colorante y la posterior visualización de su difusión en espacios intersticiales.

Un<em&gt; In vivo</em&gt; Ensayo de prueba de permeabilidad Vasos Sanguíneos

This method is based on the intravenous injection of Evans Blue in mice as the test animal model. Evans blue is a dye that binds albumin. Under ...

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Medicine

An in vivo Assay to Test Blood Vessel Permeability

63.9K vistas.  Fox Chase Cancer Center. Estamos presentando un In vivo Ensayo para probar la permeabilidad de los vasos sanguíneos. Este ensayo se basa en la inyección intravenosa de un colorante y la posterior visualización de su difusión en espacios intersticiales.

Video: An in vivo Assay to Test Blood Vessel Permeability

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment

Certain classes of chemotherapies may exert acute vascular changes that may progress into long-term conditions that may predispose the patient to an increased risk of vascular morbidity.&#160;Yet, albeit&#160;the mounting clinical evidence, there is a paucity of clear studies of vascular toxicity and therefore the etiology of a heterogeneous group of vascular/cardiovascular disorders remains to be elucidated. Moreover, the mechanism that may underlie vascular toxicity can completely differ from the principles of chemotherapy-induced cardiotoxicity, which is related to direct myocyte injury. We have established a real-time, in vivo molecular imaging platform&#160;to evaluate&#160;the potential&#160;acute&#160;vascular toxicity of anti-cancer therapies.
We have set up a platform of in vivo, high-resolution molecular imaging&#160;in mice,&#160;suitable for visualizing vasculature within confined organs and reference blood vessels within the same individuals whereas each individual serve as its own control. Blood vessel walls were impaired after doxorubicin administration, representing a unique mechanism of vascular toxicity that may be the early event in end-organ injury. Herein, the method of fibered confocal fluorescent microscopy (FCFM) based imaging is described, which provides an innovative mode to understand physiological phenomena at the cellular and sub-cellular levels in animal subjects.

Chemotherapy-induced Vascular Toxicity - Real-time In vivo Imaging of Vessel Impairment

We herein describe the method of fibered confocal fluorescent microscopy (FCFM) based imaging, which provides an innovative mode to understand physiological phenomena at the cellular and sub-cellular levels in animal subjects.

Inducida por la quimioterapia Vascular Toxicidad - En tiempo real<em&gt; En vivo</em&gt; Imagen de Deterioro del buque

Certain classes of chemotherapies may exert acute vascular changes that may progress into long-term conditions that may predispose the patient to an ...

Investigación

Medicina

Ex Vivo Intestinal Sacs to Assess Mucosal Permeability in Models of Gastrointestinal Disease

The epithelial barrier is the first innate defense of the gastrointestinal tract and selectively regulates transport from the lumen to the underlying tissue compartments, restricting the transport of smaller molecules across the epithelium and almost completely prohibiting epithelial macromolecular transport. This selectivity is determined by the mucous gel layer, which limits the transport of lipophilic molecules and both the apical receptors and tight junctional protein complexes of the epithelium. In vitro cell culture models of the epithelium are convenient, but as a model, they lack the complexity of interactions between the microbiota, mucous-gel, epithelium and immune system. On the other hand, in vivo assessment of intestinal absorption or permeability may be performed, but these assays measure overall gastrointestinal absorption, with no indication of site specificity. Ex vivo permeability assays using &#34;intestinal sacs&#34; are a rapid and sensitive method of measuring either overall intestinal integrity or comparative transport of a specific molecule, with the added advantage of intestinal site specificity. Here we describe the preparation of intestinal sacs for permeability studies and the calculation of the apparent permeability (Papp) of a molecule across the intestinal barrier. This technique may be used as a method of assessing drug absorption, or to examine regional epithelial barrier dysfunction in animal models of gastrointestinal disease.

Ex Vivo Intestinal Sacs to Assess Mucosal Permeability in Models of Gastrointestinal Disease

This protocol describes the use of excised intestinal tissue preparations or "intestinal sacs" as an ex vivo model of intestinal barrier function. This model may be used to assess integrity of both the epithelial barrier and the mucous gel layer at specific intestinal sites in animal models of digestive disease.

Ex Vivo intestinal Sacs para evaluar la permeabilidad de la mucosa en modelos de enfermedad gastrointestinal

The epithelial barrier is the first innate defense of the gastrointestinal tract and selectively regulates transport from the lumen to the underlying ...

Depletion of Mouse Cells from Human Tumor Xenografts Significantly Improves Downstream Analysis of Target Cells

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic patient tumors in different assays1. Human tumor xenografts represent the gold standard with respect to tumor biology, drug discovery, and metastasis research 2-4. Tumor xenografts can be derived from different types of material like tumor cell lines, tumor tissue from primary patient tumors4 or serially transplanted tumors. When propagated in vivo, xenografted tissue is infiltrated and vascularized by cells of mouse origin. Multiple factors such as the tumor entity, the origin of xenografted material, growth rate and region of transplantation influence the composition and the amount of mouse cells present in tumor xenografts. However, even when these factors are kept constant, the degree of mouse cell contamination is highly variable.
Contaminating mouse cells significantly impair downstream analyses of human tumor xenografts. As mouse fibroblasts show high plating efficacies and proliferation rates, they tend to overgrow cultures of human tumor cells, especially slowly proliferating subpopulations. Mouse cell derived DNA, mRNA, and protein components can bias downstream gene expression analysis, next-generation sequencing, as well as proteome analysis 5. To overcome these limitations, we have developed a fast and easy method to isolate untouched human tumor cells from xenografted tumor tissue. This procedure is based on the comprehensive depletion of cells of mouse origin by combining automated tissue dissociation with the benchtop tissue dissociator and magnetic cell sorting. Here, we demonstrate that human target cells can be can be obtained with purities higher than 96% within less than 20 min independent of the tumor type.

Human tumor xenografts are vascularized and infiltrated by cells of mouse origin during the growth phase in vivo. To circumvent the bias caused by these contaminating cells during downstream analysis, we developed a method allowing for comprehensive depletion of all mouse cells by magnetic cell sorting.

El agotamiento de las células de ratón a partir de xenoinjertos de tumores humanos mejora significativamente análisis de aguas abajo de las células diana

The use of in vitro cell line models for cancer research has been a useful tool. However, it has been shown that these models fail to reliably mimic ...

In Vitro Assays to Assess Blood-brain Barrier Mesh-like Vessel Formation and Disruption

Blood-brain barrier (BBB) coverage plays a central role in the homeostasis of the central nervous system (CNS). The BBB is dynamically maintained by astrocytes, pericytes and brain endothelial cells (BECs). Here, we detail methods to assess BBB coverage using single cultures of immortalized human BECs, single cultures of primary mouse BECs, and a humanized triple culture model (BECs, astrocytes and pericytes) of the BBB. To highlight the applicability of the assays to disease states, we describe the effect of oligomeric amyloid-&#946; (oA&#946;), which is an important contributor to Alzheimer&#39;s disease (AD) progression, on BBB coverage. Further, we utilize the epidermal growth factor (EGF) to illuminate the drug screening potential of the techniques. Our results show that single and triple cultured BECs form meshwork-like structures under basal conditions, and that oA&#946; disrupts this cell meshwork formation and degenerates the preformed mesh structures, but EGF blocks this disruption. Thus, the techniques described are important for dissecting fundamental and disease-relevant processes that modulate BBB coverage.

In Vitro Assays to Assess Blood-brain Barrier Mesh-like Vessel Formation and Disruption

Maintaining blood-brain barrier coverage is key for the homeostasis of the central nervous system. This protocol describes in vitro techniques to delineate the fundamental and pathological processes that modulate blood-brain barrier coverage.

Ensayos in vitro para evaluar la formación y la interrupción de los vasos sanguíneos de barrera hematoencefálica

Blood-brain barrier (BBB) coverage plays a central role in the homeostasis of the central nervous system (CNS). The BBB is dynamically maintained by ...

The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo

The human placenta is highly inaccessible for research while still in utero. The current understanding of human placental physiology in vivo is therefore largely based on animal studies, despite the high diversity among species in placental anatomy, hemodynamics and duration of the pregnancy. The vast majority of human placenta studies are ex vivo perfusion studies or in vitro trophoblast studies. Although in vitro studies and animal models are essential, extrapolation of the results from such studies to the human placenta in vivo is uncertain. We aimed to study human placenta physiology in vivo at term, and present a detailed protocol of the method. Exploiting the intraabdominal access to the uterine vein just before the uterine incision during planned cesarean section, we collect blood samples from the incoming and outgoing vessels on the maternal and fetal sides of the placenta. When combining concentration measurements from blood samples with volume blood flow measurements, we are able to quantify placental and fetal uptake and release of any compound. Furthermore, placental tissue samples from the same mother-fetus pairs can provide measurements of transporter density and activity and other aspects of placental functions in vivo. Through this integrative use of the 4-vessel sampling method we are able to test some of the current concepts of placental nutrient transfer and metabolism in vivo, both in normal and pathological pregnancies. Furthermore, this method enables the identification of substances secreted by the placenta to the maternal circulation, which could be an important contribution to the search for biomarkers of placenta dysfunction.

The 4-vessel Sampling Approach to Integrative Studies of Human Placental Physiology In Vivo

We present a detailed method to study human placental physiology in vivo at term. The method combines blood sampling from the incoming and outgoing vessels on the maternal and fetal sides of the placenta with ultrasound measurements of volume blood flow and placental tissue sampling.

El Método de Muestreo de 4 Barcos para Estudios Integrativos de la Fisiología Placentaria Humana<em&gt; In Vivo</em

The human placenta is highly inaccessible for research while still in utero. The current understanding of human placental physiology in vivo is therefore ...

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. To better understand the mechanism behind these surgical procedures, a rat partial liver transplantation (PLTx) model was established for relevant surgical studies. Because of the complexity of the rat PLTx model, a protocol with detailed descriptions is required. An article published previously reported a protocol in which ex vivo hepatectomy was used to achieve 50% rat PLTx. In contrast to this protocol, we introduced a re-arterialized PLTx with an in vivo 70% hepatectomy. An updated vessel-oriented hepatectomy was incorporated into the rat PLTx to refine the microsurgical procedure. The portal veins and hepatic arteries of the left lateral lobe and the median lobe were individually dissected and ligated before removal of the liver parenchyma, thereby decreasing the probability of bleeding in the remnant liver stump. Furthermore, an end-to-side vessel anastomosis between the common hepatic artery and the enlarged proper hepatic artery was introduced to re-arterialize the hepatic artery. By using this end-to-side vessel anastomosis technique, the diameter of the anastomosis was enlarged, thereby decreasing the difficulty of hand suture and maintaining a high rate of anastomotic patency. Moreover, the cuff anastomosis of the infrahepatic vena cava was slightly modified. A section of circumferential liver parenchyma around the vena cava of a recipient was preserved during cuff anastomosis to maintain the three-dimensional shape of the vascular lumen. This section of liver parenchyma was removed after completing the anastomosis. With this modification, the step involving placement of stay sutures was omitted, thereby further shortening the cuff anastomosis time. By using this protocol of rat PLTx, a low liver enzyme level, an intact liver lobular architecture and a high survival rate were achieved after microsurgery.

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Here, a protocol involving re-arterialized rat partial liver transplantation is presented. Specifically, 70% liver was resected in vivo by using an updated technique of vessel-oriented hepatectomy. The hepatic artery was reconstructed in an end-to-side manner. The cuff technique was modified to shorten the anastomosis time of the infrahepatic vena cava.

Volver a arterializada rata parcial trasplante del hígado con una en vivo orientada al barco 70% hepatectomía

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. ...

An In Vivo Method for Evaluating the Gut-Blood Barrier and Liver Metabolism of Microbiota Products

The gut-blood barrier (GBB) controls the passage of nutrients, bacterial metabolites and drugs from intestinal lumen to the bloodstream. The GBB integrity is disturbed in gastrointestinal, cardiovascular and metabolic diseases, which may result in easier access of biologically active compounds, such as gut bacterial metabolites, to the bloodstream. Thus, the permeability of the GBB may be a marker of both intestinal and extraintestinal diseases. Furthermore, the increased penetration of bacterial metabolites may affect the functioning of the entire organism.
Commonly used methods for studying the GBB permeability are performed ex vivo. The accuracy of those methods is limited, because the functioning of the GBB depends on intestinal blood flow. On the other hand, commonly used in vivo methods may be biased by liver and kidney performance, as those methods are based on evaluation of urine or/and peripheral blood concentrations of exogenous markers. Here, we present a direct measurement of GBB permeability in rats using an in vivo method based on portal blood sampling, which preserves intestinal blood flow and is virtually not affected by the liver and kidney function. 
Polyurethane catheters are inserted into the portal vein and inferior vena cava just above the hepatic veins confluence. Blood is sampled at baseline and after administration of a selected marker into a desired part of the gastrointestinal tract. Here, we present several applications of the method including (1) evaluation of the colon permeability to TMA, a gut bacterial metabolite, (2) evaluation of liver clearance of TMA, and (3) evaluation of a gut-portal blood-liver-peripheral blood pathway of gut bacteria-derived short-chain fatty acids. Furthermore, the protocol may also be used for tracking intestinal absorption and liver metabolism of drugs or for measurements of portal blood pressure.

An In Vivo Method for Evaluating the Gut-Blood Barrier and Liver Metabolism of Microbiota Products

The access of nutrients, microbiota metabolites and medicines to the circulation is controlled by the gut-blood barrier (GBB). We describe a direct method for measuring the GBB permeability in vivo, which, in contrast to commonly used indirect methods, is virtually not affected by liver and kidney functions.

Un método In Vivo para evaluar la barrera intestinal-sangre y hígado metabolismo de la Microbiota de productos

The gut-blood barrier (GBB) controls the passage of nutrients, bacterial metabolites and drugs from intestinal lumen to the bloodstream. The GBB integrity ...

Using an Automated Hirschberg Test App to Evaluate Ocular Alignment

A smartphone app has been developed to perform the automated photographic Hirschberg test for objective measurement of ocular misalignment. By computing the difference in corneal reflection generated by the phone camera flash relative to the iris center based on high resolution images, the app can measure misalignment with a much higher precision than the naked eye performing the Hirschberg test. It has been validated in a previous clinical evaluation study by comparing to the clinical gold standard-prism and alternate cover test. The goal of this article is to describe the testing techniques regarding how to use the app to measure ocular alignment for different fixation distances, without or with cover to break fusion, as well as angle kappa, so that users can use the app to perform equivalent tests typically done in clinic using prisms.

We present a protocol of using a smartphone app to perform Hirschberg test for measuring manifest and intermittent ocular misalignment (strabismus) under near and far fixation conditions.

Uso de una aplicación de prueba de Hirschberg automatizada para evaluar la alineación ocular

A smartphone app has been developed to perform the automated photographic Hirschberg test for objective measurement of ocular misalignment. By computing ...

Measurement of Strial Blood Flow in Mouse Cochlea Utilizing an Open Vessel-Window and Intravital Fluorescence Microscopy

Transduction of sound is metabolically demanding, and the normal function of the microvasculature in the lateral wall is critical for maintaining endocochlear potential, ion transport, and fluid balance. Different forms of hearing disorders are reported to involve abnormal microcirculation in the cochlea. Investigation of how cochlear blood flow (CoBF) pathology affects hearing function is challenging due to the lack of feasible interrogation methods and the difficulty in accessing the inner ear. An open vessel-window in the lateral cochlear wall, combined with fluorescence intravital microscopy, has been used for studying CoBF changes in vivo, but mostly in guinea pig and only recently in the mouse. This paper and the associated video describe the open vessel-window method for visualizing blood flow in the mouse cochlea. Details include 1) preparation of the fluorescent-labeled blood cell suspension from mice; 2) construction of an open vessel-window for intravital microscopy in an anesthetized mouse, and 3) measurement of blood flow velocity and volume using an offline recording of the imaging. The method is presented in video format to show how to use the open window approach in mouse to investigate structural and functional changes in the cochlear microcirculation under normal and pathological conditions.

An open vessel-window approach using fluorescent tracers provides sufficient resolution for cochlear blood flow (CoBF) measurement. The method facilitates the study of structural and functional changes in CoBF in mouse under normal and pathological conditions.

Medición del flujo sanguíneo auricular en cóclea de ratón utilizando una ventana de vaso abierto y microscopía de fluorescencia intravital

Transduction of sound is metabolically demanding, and the normal function of the microvasculature in the lateral wall is critical for maintaining ...

Precision Cut Lung Slices as an Efficient Tool for Ex vivo Pulmonary Vessel Structure and Contractility Studies

The visualization of murine lung tissue provides valuable structural and cellular information regarding the underlying airway and vasculature. However, the preservation of pulmonary vessels that truly represents physiological conditions still presents challenges. In addition, the delicate configuration of murine lungs result in technical challenges preparing samples for high-quality images that preserve both cellular composition and architecture. Similarly, cellular contractility assays can be performed to study the potential of cells to respond to vasoconstrictors in vitro, but these assays do not reproduce the complex environment of the intact lung. In contrast to these technical issues, the precision-cut lung slice (PCLS) method can be applied as an efficient alternative to visualize lung tissue in three dimensions without regional bias and serve as a live surrogate contractility model for up to 10 days. Tissue prepared using PCLS has preserved structure and spatial orientation, making it ideal to study disease processes ex vivo. The location of endogenous tdTomato-labeled cells in PCLS harvested from an inducible tdTomato reporter murine model can be successfully visualized by confocal microscopy. After exposure to vasoconstrictors, PCLS demonstrates the preservation of both vessel contractility and lung structure, which can be captured by a time-lapse module. In combination with the other procedures, such as western blot and RNA analysis, PCLS can contribute to the comprehensive understanding of signaling cascades that underlie a wide variety of disorders and lead to a better understanding of the pathophysiology in pulmonary vascular diseases.

Precision Cut Lung Slices as an Efficient Tool for Ex vivo Pulmonary Vessel Structure and Contractility Studies

Presented here is a protocol for preserving the vascular contractility of PCLS murine lung tissue, resulting in a sophisticated three-dimensional image of the pulmonary vasculature and airway, which can be preserved for up to 10 days that is susceptible to numerous procedures.

Cortes pulmonares de corte de precisión como herramienta eficiente para estudios ex vivo de estructura de vasos pulmonares y contractilidad

The visualization of murine lung tissue provides valuable structural and cellular information regarding the underlying airway and vasculature. However, ...