Questo lavoro è stato sostenuto da una sovvenzione da parte del National Institutes of Health, R01CA142928.

1. Iniezione endovenosa di Evans Blue in the Vein laterale coda di topo <ol><li> Preparare una soluzione allo 0,5% sterile di blu di Evans in PBS. Se necessario, filtro sterilizzare la soluzione per rimuovere particelle che non è dissolto. </li><li> Aspirare 200 ul Evans soluzione di blu in una siringa. Evitare tutte le bolle d&#39;aria che possano esser sfuggite nella siringa. </li><li> Luogo topi che sono 8-12 settimane di vita in un dispositivo di ritenuta in modo che l&#39;animale non è liberamente mobile, ma la coda può essere gestito. </li><li> Posizionare il dispositivo di ritenuta del mouse sul fianco con la vena caudale laterale è facilmente visibile e sono rivolti verso l&#39;alto. </li><li> Tenere su la coda con la mano non dominante tra il pollice e l&#39;indice. </li><li> Inserire l&#39;ago (calibro piccolo, 27-30) in un anticipo 10-15 gradi, smussata, nella vena caudale laterale verso la direzione della testa. Tenere il parallelepipedo ago e la siringa alla coda. </li><li> Do non si applica la contropressione per confermare il corretto posizionamento in quanto ciò potrebbe comprimere la vena. </li><li> Iniettare lentamente 200 microlitri soluzione Evans blu nella vena della coda del topo. </li><li> Osservare la facilità con cui gli anticipi stantuffo, poiché questa è la prova di corretto posizionamento dell&#39;ago nella vena. </li><li> Ponga il mouse di nuovo nella sua gabbia e osservare per 30 minuti. </li></ol> 2. Organo Raccolta ed estrazione di Evans Blue dagli organi <ol><li> Sacrifica i topi tramite dislocazione cervicale. Ai fini del test Miles dislocazione cervicale è raccomandato in quanto limita la grave interferenza con la permeabilità vascolare. Sacrificare tutti i topi al tempo stesso, il più velocemente possibile. Lavora con coorti di 6 topi o meno, perché poco dopo la morte i vasi sanguigni diventano più permeabili. </li><li> Mettere i topi sulla schiena e il pin i piedi su un bordo bianco. </li><li> Aprire la cavità addominale e toracica per esporre thororgani ACIC e addominale. </li><li> Scatta foto rappresentative per mostrare le differenze di stravaso Evans Blue. Includere tutti i topi nello stesso campo in modo da avere condizioni di luce identiche per tutti i mouse. </li><li> Raccogliere gli organi di interesse e metterli in provette da 1,5 ml </li><li> Pesare un tubo vuoto e portare il valore di bilancio a zero. </li><li> Trasferire il campione di tessuto e peso. Ripetere l&#39;operazione per tutti i campioni di tessuto. Tessuti può essere essiccato per eliminare la variabilità contenuto di acqua tra diversi organi. </li><li> . Aggiungere 500 microlitri formammide in ogni provetta campione di tessuto. </li><li> Trasferire tutte le provette in un bagno d&#39;acqua ° 55 C o di un blocco di calore. Incubare per 24-48 ore per estrarre i Blu di Evans dal tessuto. </li></ol> 3. Quantificazione di Evans Blue travasato nel tessuto interstiziale <ol><li> Centrifugare la formammide / Evans miscela blu per far sedimentare i frammenti di tessuto rimanenti. </li><li> Misurare l&#39;assorbanza a 610nm. Usare 500 microlitri Formammide come bianco. </li><li> Calcola ng Evans Blue stravaso per mg di tessuto. </li><li> Tracciare tutti i dati in un grafico. </li><li> Eseguire l&#39;analisi statistica per determinare differenze significative. </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>

Gli autori non hanno alcun conflitto o in competizione interessi finanziari.

Permeabilità vascolare è un indicatore fondamentale per lo stato dei vasi sanguigni. Aumento della permeabilità vascolare ha dimostrato di essere presente in numerose malattie sistemiche, compreso il diabete, ipertensione e malattie autoimmuni 6,7,8. Aumento della permeabilità vascolare ha dimostrato di essere mediata da shear stress, fattori di crescita come il fattore di crescita vascolare endoteliale e fattore di crescita dei fibroblasti, mediatori infiammatori quali serotonina, istamina e bradichinina...

Formazione e il mantenimento di barriere permeabili selettive sono essenziali per lo sviluppo di organi corretto e 1,2 prestazioni. Cellule endoteliali linea lume del vaso sanguigno e formano una barriera semipermeabile che è essenziale per il trasporto selettivo tra sangue e lo spazio interstiziale di tutti gli organi. Una barriera di permeabilità adeguata è mantenuta attraverso stretti cellula-cellula giunzioni che sono strettamente controllate da fattori di crescita, citochine e molecole correlate allo stress altri 3. Deterioramento della barriera endoteliale può causare aumentata permeabilità vascolare e perdite. Questi effetti sono visti in diversi stati patologici e la comprensione della segnalazione sottolineatura molecolare richiede metodi multidisciplinari 4,5. In questo articolo, si descrive un metodo in vivo per misurare la permeabilità nave che utilizza un modello di topo. Il saggio stiamo descrivendo, anche noto come saggio Miles, è una ben establmentata metodo per testare la permeabilità vascolare in vivo. Il saggio è basato sul fatto che, in condizioni fisiologiche basali, albumina non attraversa la barriera endoteliale. Evans blu, un colorante azoico con alta affinità per l&#39;albumina, viene iniettato nel flusso sanguigno di un animale sperimentale, e in condizioni fisiologiche, esso dovrebbe essere limitato entro vasi sanguigni. Quando uno stimolo permeabilità vascolare è aggiunto, sia a livello topico o per via sistemica, i vasi sanguigni iniziano a perdere proteine ​​e, quindi, anche il blu Evans che è legato all&#39;albumina. Ciò provoca una colorazione bluastra rapida dei tessuti che hanno vasi permeabili. Iniezione di successo del colorante nella vena laterale della coda del mouse è fondamentale per il buon esito dell&#39;esperimento. Vena tecnica Tail iniezione richiede pratica estesa e deve essere masterizzato prima di iniziare l&#39;esperimento. Permeabilità vasale è fortemente dipendente dall&#39;età e dal peso del l&#39;IMAL, così quando si confrontano diversi ceppi di topi è imperativo che i topi o dei soggetti di prova diversi da avere vicino date di nascita e peso identici. Altri fattori che influenzano la permeabilità della barriera endoteliale sono condizioni ambientali come temperatura, umidità, e molto importante, lo stress manipolazione del mouse. A causa del gran numero di fattori che possono influenzare l&#39;esito dell&#39;esperimento è sempre consigliabile che l&#39;esperimento viene ripetuto almeno tre volte e analisi statistica effettuata. Questo test può essere utilizzato o per confrontare permeabilità vasale di topi che sono stati geneticamente modificati, nonché topi con differenti background genetico. Permeabilità può essere valutata in presenza o assenza di uno stimolo, a seconda della funzione del gene che è modulato. Questo dosaggio può anche essere utilizzato o per testare l&#39;effetto di composti differenti permeabilità vasale.

<table border="1"><tbody><tr><td></td><td></td><td></td><td> REAGENTE </td></tr><tr><td> EVANS BLU </td><td> SIGMA </td><td> E2129 </td><td></td></tr><tr><td> FORMAMIDE </td><td> INVITROGEN </td><td> 15515-026 </td><td></td></tr><tr><td> PBS </td><td></td><td></td><td> Fosfato 0,2 M 1.5M NaCl pH 7,4 </td></tr><tr><td></td><td></td><td></td><td> ATTREZZATURE </td></tr><tr><td> SPETTROFOTOMETRO </td><td> EPPENDORF </td><td> 952000006 </td><td></td></tr><tr><td> MOUSE dispositivo di sicurezza per </td><td> Harvard Apparatus </td><td> 340012 </td><td></td></tr><tr><td> SIRINGA </td><td> BD </td><td> 309659 </td><td></td></tr><tr><td> AGHI </td><td> BD </td><td> 305106 </td><td> Il calibro dell&#39;ago dipende dalla taglia dell&#39;animale. </td></tr><tr><td> SALDO </td><td> DENVER STRUMENTO </td><td> TP-64 </td><td></td></tr></tbody></table>

an in vivo assay to test blood vessel permeability

Questo metodo si basa sulla iniezione endovenosa di Evans blu in topi come modello animale di prova. Blu di Evans è un colorante che si lega all&#39;albumina. In condizioni fisiologiche l&#39;endotelio è impermeabile all&#39;albumina, in modo da Evans blu resti albumina legata restrizioni all&#39;interno dei vasi sanguigni. In condizioni patologiche che promuovere un aumento della permeabilità delle cellule endoteliali vascolari parzialmente perdono i loro contatti stretti e l&#39;endotelio diventa permeabile alle proteine ​​di piccole dimensioni come l&#39;albumina. Questa condizione consente per lo stravaso di Blu di Evans nei tessuti. Un endotelio sano impedisce stravaso del colorante nei tessuti circostanti vascolarizzati. Organi con aumento della permeabilità mostrerà significativamente aumentata colorazione blu rispetto a organi con endotelio intatto. Il livello di permeabilità vascolare può essere valutata mediante semplice visualizzazione o misurazione quantitativa del colorante incorporato per milligrammo di tessuto di controllo contro animale sperimentale / tessuto. Due PoweRFUL aspetti di questo test è la sua semplicità e le caratteristiche quantitative. Evans blu colorante può essere estratto dai tessuti incubando una quantità specifica di tessuto in formammide. Evans Blue è massima assorbanza a 620 nm e minimo assorbimento è a 740 nm. Utilizzando una curva standard per Evans blu, misure di densità ottica può essere convertito in colorante milligrammo catturato per milligrammo di tessuto. Analisi statistica dovrebbe essere utilizzato per valutare le differenze significative nella permeabilità vascolare.

Abbiamo utilizzato un saggio di permeabilità in vivo per verificare perdite nave in topi 8-12 settimane di vita. Questo test è utile per confrontare la relativa permeabilità vascolare tra animali di diverso background genetico o in un singolo ceppo di topi sottoposti a trattamenti che colpiscono il sistema vascolare. I nostri risultati mostrano che un ceppo di topi geneticamente modificati che abbiamo creato nel nostro laboratorio ha un endotelio più permeabile rispetto ai topi wild-type. Questi ca...

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

Stiamo presentando un<em&gt; In vivo</em&gt; Saggio per testare vaso sanguigno permeabilità. Questo saggio è basato sulla iniezione endovenosa di un colorante e la successiva visualizzazione della sua diffusione negli spazi interstiziali.

Un<em&gt; In vivo</em&gt; Test per la verifica della nave Permeabilità Sangue

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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An in vivo Assay to Test Blood Vessel Permeability

63.9K Views.  Fox Chase Cancer Center. Stiamo presentando un In vivo Saggio per testare vaso sanguigno permeabilità. Questo saggio è basato sulla iniezione endovenosa di un colorante e la successiva visualizzazione della sua diffusione negli spazi interstiziali.

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.

Chemioterapia-indotta vascolare Tossicità - in tempo reale<em&gt; In vivo</em&gt; Imaging di 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 ...

Ricerca

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 intestinale Sacs per valutare mucosa Permeabilità in modelli di malattia gastrointestinale

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.

L&#39;esaurimento delle cellule di topo da xenotrapianti tumorali umani migliora in modo significativo Analisi A valle delle cellule bersaglio

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.

In vitro dosaggi per valutare la formazione e la rottura del vaso come la barriera emato-cerebrale

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.

L&#39;approccio di campionamento a 4 nave per studi integrativi della fisiologia placentare umana<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.

Ri-Arterialized trapianto parziale di fegato del ratto con un in vivo vaso-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. ...

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 metodo In Vivo per valutare la Gut-barriera e metabolismo epatico del Microbiota prodotti

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.

Utilizzo di un'app di test Hirschberg automatizzata per valutare l'allineamento oculare

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.

Misurazione del flusso sanguigno striale nella coclea di topo utilizzando una finestra del vaso aperta e microscopia a fluorescenza intravitale

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.

Fette polmonari tagliate con precisione come strumento efficiente per studi ex vivo sulla struttura dei vasi polmonari e sulla contrattilità

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