Diese Arbeit wurde zum Teil durch einen Zuschuss aus dem amerikanischen otologischen Gesellschaft zu CAM und durch einen Zuschuss von der University Hospitals Case Medical Center, um KNA und CAM unterstützt. Wir möchten Jeff Churney bei Focus Medical Group, Inc. (Hinckley, OH) bedanken, die uns mit einem Mikroskop-Kamera. Video Production Services zur Verfügung gestellt von Fusion Creative Marketing, Inc. (Valdosta, GA) Wir danken Jonathan Frankel und Alex Levitt an CWRU für ihre Kommentare während der Vorbereitung des Videos.

Teil 1: Anästhesie und Vorbereitung für die Chirurgie <ol><li> Ein Erwachsener, weiblich ist Duncan-Hartley Meerschweinchen von Charles River International Laboratories, Inc. (Wilmington, MA) mit Ketamin 60 mg / kg und Xylazin 12 mg / kg intramuskulär. </li><li> Petroleum Schmierstoff wird auf die Augen aufgetragen, um das Tier aus Verletzung der Hornhaut durch Austrocknung zu schützen. </li><li> Das Tier ist von der Oberseite des Kopfes bis zu den Schultern und zwischen den Ohren rasiert. </li><li> Die rasierten Bereich wird in einem sterilen Mode zunächst mit 7,5% PVP-Jod um 70% Ethylalkohol, gefolgt vorbereitet. </li><li> Das Tier wird auf einen OP-Tisch mit wärmenden Decke und auf eine Plattform, die den Kopf und beugt den Hals erhebt platziert. Der Kopf des Tieres wird vom Operateur weg gerichtet ist. Ausreichende Flexion der Hals ist erforderlich, um ausreichend Setzen Sie die Crista occipitalis. </li><li> Das Tier wird in einem sterilen Mode drapiert. </li></ol> Teil 2: Inzision und Freilegung des knöchernen Hinterhaupt <ol><li> Bupivacain und Adrenalin (Marcain) 0,25% liegt an der prospektiven Inzisionsstelle (Mittellinie dorsal Hautschnitt entlang der Hinterhauptbein) angewendet. Dies führt dazu, lokale Vasokonstriktion, die Begrenzung Blutungen und bietet dauerhaften postoperativen Analgesie nach dem Tier erwacht. </li><li> Midline dorsalen Hautschnitt auf der Kopfhaut entlang den Hinterkopf gemacht. <img src="/files/ftp_upload/1728/1728fig1.jpg" alt="Abbildung 1" /> Abbildung 1: Hautschnitt wird entlang der dorsalen Mittellinie gemacht, wie oben gezeigt. </li><li> Um sich eine ausreichende Belichtung wird die Haut seitlich, indem Sie einen kleinen gebogenen hemostat auf jeder Seite des Schnittes eingefahren. </li><li> Ein horizontaler Schnitt entlang der Nackenmuskulatur hat, um die knöchernen Hinterhaupt aussetzen. In diesem Stadium kann das Tier trotz ausreichender Betäubung durch Durchtrennung des N. occipitalis major zucken. Durchtrennung des Rückenmarks besteht die Gefahr, mit horizontaler Schnitt in die subokzipitalen Region. Diese Komplikation kann durch Sicherstellung, dass darunter liegende Knochen ist immer unter dem Skalpell fühlte vermieden werden. </li><li> Mit dem Subokzipitalmuskulatur eingeschnitten, um die Knochen, ist ein Drittel hemostat verwendet werden, um die überlegene Muskelkraft Rand zurückzuziehen. Diese hemostat wird anstelle von der OP-Assistenz statt. </li><li> Ein Lempert Raspatorium wird verwendet, um die temporo-occipital Naht aussetzen. </li></ol> Teil 3: Bohren der temporo-occipital Naht <ol><li> Bei der Belichtung des temporo-occipital-Naht (Abb. 2), ein otologischer Bohrer mit 1,5 mm Diamantbohrer wird verwendet, um inferio-seitlich zu bohren, um die Naht. </li><li> Unterhalb der äußeren Tabelle des Schädels, wird die schwammige Struktur des Diploe (Die dazwischenliegende Spongiosa zwischen Tabellen des Schädels) sichtbar werden. Sobald die Diploe ist weg gebohrt wurden, wird die innere Tabelle des Schädels, zusammen mit einem schwachen blauen Farbe, die den Sinus sigmoideus ist. </li><li> Die Ränder der Sinus sigmoideus sind ohne Durchdringung des Schiffes festgelegt. </li><li> Sobald der Knochen über dem Sinus sigmoideus ausreichend verdünnt wurde, ist eine stärkere Vergrößerung genutzt und einen geraden Pick wird verwendet, um vorsichtig die Knochen über dem Sinus sigmoideus. </li></ol><img src="/files/ftp_upload/1728/1728fig2.jpg" alt="Abbildung 2" /> Abbildung 2: Das Gebiet um teilweise gebohrt werden überlagert die temporo-occipital Naht. Teil 4: Behinderung der Duct <ol><li> Die skelettierten Sinus sigmoideus ist medial des Operculum offenbaren eingefahren. </li><li> Ein 0,5 mm Diamantbohrer wird verwendet, um Drill medial des Operculum und in den Saccus endolymphaticus und Kanal. </li><li> Der Ductus endolymphaticus wird dann mit Knochen Wachs mit einem geraden Pick verpackt. </li><li> Der Schädel Defekt wird dann mit Gelfoam (Pfizer, New York, NY) verstärkt. </li><li> 4-0 POLYSORB (United States Surgical, Norwalk, CT) Naht wird verwendet, um den Muskel zusammen zu bringen. Es gibt dann einen nahtlosen Übergang zu einer subkutanen Nahttechnik für die Schließung der Hautschnitt. Mit diesem Abschluss ist es nicht erforderlich, um Nähte danach zu entfernen und es besteht keine Gefahr, dass das Tier Kralle an der Stelle und ziehen Sie eine Naht. </li></ol> Teil 5: post-operative Betreuung Das Meerschweinchen ist in einem Inkubator gelegt, um die Körpertemperatur zu erhalten und überprüft alle 30 Minuten, bis wach und in der Lage einer Sternal Position aufrecht zu erhalten. Das Tier ist für Atemfrequenz und Wagenfarbe inspiziert. Dieses Zentrum nutzt Enrofloxacin (0,2 ml bei 22,7 mg / ml, subkutan) und Buprenorphin (0,05 ml bei 0.3mg/mL, subkutan) zur postoperativen Infektionsprophylaxe und Schmerz zu kontrollieren, bzw.. Schmerzstillende wird einmal am Tag der Operation und zweimal am Tag nach der Operation ein und zwei gegeben. Obwohl Antibiotika sind nicht für die aseptische su notwendigrgery, eine Fünf-Tage-, zweimal am Tag natürlich von prophylaktischen Antibiotika kann givenonce am Tag nach der Operation drei sein. Komplikationen und Management <ol><li> Atemdepression Der Chirurg sollte immer bewusst sein, das Tier s Atmung. Wenn die Atmung verlangsamt oder stoppt, schalten Chirurgie und visuell für Thorax-Bewegung zu untersuchen. Wenn das Tier erlebt Atembeschwerden oder Atemnot, überprüfen Sie, dass die Mund-und Atemwege sind nicht verschlossen. </li><li> Sinus sigmoideus Eindringen Verwenden Gelfoam und Kompression zusammen mit dem Saug-Spitze bis die Blutung gestoppt ist. </li><li> Dural Eindringen Abdeckung des Defektes mit Gelfoam. </li><li> Vestibular Schäden Bohren Sie nicht mehr als 1 mm lateral des Sinus sigmoideus. Sonst riskieren Sie Verletzungen des hinteren Bogenganges, die alle Daten für die Meerschweinchen ungültig machen würden. </li></ol>

<ol>
	<li>Andrews, J. C., Bohmer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+surgical+approach+to+the+endolymphatic+sac+and+the+cochlear+aqueduct+in+the+guinea+pig.">The surgical approach to the endolymphatic sac and the cochlear aqueduct in the guinea pig.</a> Am J Otolaryngol. 10, 61-66 (1989).</li><li>Kimura, R., Schuknecht, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membranous+hydrops+in+the+inner+ear+of+the+guinea+pig+after+obliteration+of+the+endolymphatic+sac.">Membranous hydrops in the inner ear of the guinea pig after obliteration of the endolymphatic sac.</a> Pract Otolaryngol. , (1965).</li></ol>

Tierversuche wurden in Übereinstimmung mit den Richtlinien und Vorschriften her durch die Institutional Animal Care und Verwenden Ausschuss an der Case Western Reserve University gesetzt durchgeführt.

In den Wochen nach chirurgischer Verschluss des Ductus endolymphaticus, erfährt das Tier unter schwankenden Hörverlust durch akustisch evozierte Hirnstamm Reaktion gemessen. Eine Probe des auditorischen Hirnstamm Reaktion (ABR) Aufnahme ist in Abbildung 3 dargestellt. Das linke Ohr dient als nicht operierte Kontrolle. <a href="https://www.jove.com/files/ftp_upload/1728/1728fig4.jpg"><img border="0" src="/files/ftp_upload/1728/1728fig3tmb.jpg" alt="Abbildung 3" /></a> Abbildung 3: ABR Sch...

surgical induction of endolymphatic hydrops by obliteration of the endolymphatic duct

Chirurgische Induktion von endolymphatischen Hydrops (ELH) beim Meerschweinchen durch Verödung und Obstruktion des Ductus endolymphaticus ist ein gut anerkanntes Tiermodell der Erkrankung und ein wichtiges Korrelat für den menschlichen Morbus Menière. Im Jahre 1965, Robert Kimura und Harold Schuknecht zum ersten Mal beschrieben ein intradural Ansatz zur Obstruktion der Ductus endolymphaticus (Kimura 1965). Obwohl wirksame, entstehen diese Technik, die das Eindringen des Gehirns Schutzhülle erfordert, ein unerwünschtes Niveau der Morbidität und Mortalität in der Tier-Themen. Folglich entwickelt Andrews und Böhmer extraduralen Ansatz, der vorhersehbar produziert weniger von den Komplikationen des zentralen Nervensystems (ZNS) Penetration. (Andrews und Böhmer 1989) verbunden Die extraduralen hier beschriebene Ansatz erfordert zuerst eine Mittellinienschnitt in der Region den Hinterkopf auf die zugrunde liegenden muskulären Schicht freizulegen. Wir arbeiten nur auf der rechten Seite. Nach entsprechender Rücknahme der darüberliegenden Gewebe, wird ein horizontaler Schnitt in der Muskulatur des rechten Hinterhaupt nach rechts temporo-occipital Nahtlinie freizulegen. Der Knochen sofort inferio-lateral der Naht (Abb. 1) wird dann mit einem otologischer gebohrt, bis der Sinus sigmoideus sichtbar. Medial Zurückziehen des Sinus sigmoideus zeigt das Operculum des Ductus endolymphaticus, der Saccus endolymphaticus Häuser. Drilling medial des Operculum in den Bereich des Saccus endolymphaticus zeigt die Ductus endolymphaticus, die dann mit Knochenwachs Obstruktion und letztlich ELH produzieren verpackt ist. In den folgenden Wochen wird das Tier zeigen die progressive, fluktuierende Schwerhörigkeit und histologischen Nachweis der ELH.

Watch this Scientific Journal Video about Surgical Induction of Endolymphatic Hydrops by Obliteration of the Endolymphatic Duct at JoVE.com

Surgical Induction of Endolymphatic Hydrops by Obliteration of the Endolymphatic Duct

Dieses Video zeigt, wie man chirurgisch behindern das Meerschweinchen ist Ductus endolymphaticus zu endolymphatischen Hydrops zu produzieren.

Chirurgische Induktion von Endolymphatischer Hydrops durch Obliteration des Ductus endolymphaticus

Surgical induction of endolymphatic hydrops (ELH) in the guinea pig by obliteration and obstruction of the endolymphatic duct is a well-accepted animal ...

surgical-induction-endolymphatic-hydrops-obliteration-endolymphatic

Research

JoVE Journal

Biology

11.3K Aufrufe.  Case Western Reserve University. Dieses Video zeigt, wie man chirurgisch behindern das Meerschweinchen ist Ductus endolymphaticus zu endolymphatischen Hydrops zu produzieren.

Serie: Surgical Induction of Endolymphatic Hydrops by Obliteration of the Endolymphatic Duct

Imaging Effector Memory T cells in the Ear After Induction of Adoptive DTH

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a method for inducing and recording the progress of a DTH reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the CCR7- effector / memory T cell response.
An adoptive DTH is induced by the intraperitoneal injection of GFP-labeled Ova-specific CCR7- effector / memory T cell line (Beeton, C J. Visualized Experiments, Issue 8). Cells are then allowed to equilibrate in the rat for 48 hours before challenge by injecting one ear with saline (control ear) and the other with a 1:1 mix of Ova and Ova conjugated to Texas-Red (Ova-TR) to allow visualization of resident antigen-presenting cells.
We describe a method of tissue preparation useful for imaging the motility of cells within the deep dermal layer during an immune response, in conjunction with visualization of collagen fibers by second harmonic generation. Ear tissue is cut into 5 x 5 mm squares (slightly larger is better) and mounted onto plastic cover slips using Vetbond&trade;, which are then secured using silicone grease in an imaging chamber and superfused by oxygen-bubbled tissue culture medium at 37&deg;C.

Here we demonstrate a method for inducing and recording the progress of a delayed type-hypersensitivity (DTH) reaction in the rat ear. This is followed by a demonstration of the preparation of rat ear tissue for two-photon imaging of the effector / memory T cell response.

Imaging Effektor-Memory-T-Zellen im Ohr nach Induktion der Adoptive DTH

Delayed type hypersensitivity (DTH) is an immune reaction in which the main players are CCR7- effector / memory T lymphocytes. Here, we demonstrate a ...

Forschung

Biologie

Assay for Neural Induction in the Chick Embryo

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying the formation and initial patterning of the nervous system. This video demonstrates how to graft organizer tissue into a host, a method by which Hensen s node (the organizer in the chick embryo) is grafted to a host competent ectoderm. The organizer graft instructs overlying na ve tissue to adopt a neural fate via neural inducing signals. This mechanism is referred to as neural induction, and constitutes the initial step in the formation of brain and spinal cord in amniotes. This method is essentially used for the characterization of putative neural inducing molecules in chick. This video demonstrates the different steps in the assay for neural induction; First, the donnor embryo is explanted and pinned on a dish. Then, the host embryo is prepared for New culture. The graft is excised and transplanted to the host area pellucida margin. The host is cultured for 18-22 hrs. The assembly is fixed and processed for further applications (e.g. in situ hybridization). This method was originally devised by Waddington 1,2 and Gallera 3,4.

Neural induction is the first step in the formation of the brain. It is a mechanism by which Hensen's node (organizer), instructs adjacent tissue to adopt a neural fate, i.e. to give rise to the nervous system. This video demonstrates an assay for neural induction in chick embryo.

Assay für Neural Induction im Hühnerembryo

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Microsurgical Clip Obliteration of Middle Cerebral Aneurysm Using Intraoperative Flow Assessment

Cerebral aneurysms are abnormal widening or ballooning of a localized segment of an intracranial blood vessel.  Surgical clipping is an important treatment for aneurysms which attempts to exclude blood from flowing into the aneurysmal segment of the vessel while preserving blood flow in a normal fashion.  Improper clip placement may result in residual aneurysm with the potential for subsequent aneurysm rupture or partial or full occlusion of distal arteries resulting in cerebral infarction.  Here we describe the use of an ultrasonic flow probe to provide quantitative evaluation of arterial flow before and after microsurgical clip placement at the base of a middle cerebral artery aneurysm.  This information helps ensure adequate aneurysm reconstruction with preservation of normal distal blood flow.

Description of the surgical obliteration of a cerebral aneurysm utilizing an ultrasonic flow probe to assess arterial flow prior to and after aneurysm clip placement.

Mikrochirurgische Clip Obliteration des Nahen zerebralen Aneurysmen mit Intraoperative Flow-Bewertung

Cerebral aneurysms are abnormal widening or ballooning of a localized segment of an intracranial blood vessel.  Surgical clipping is an important ...

Isolation of Basal Cells and Submucosal Gland Duct Cells from Mouse Trachea

The large airways are directly in contact with the environment and therefore susceptible to injury from toxins and infectious agents that we breath in 1. The large airways therefore require an efficient repair mechanism to protect our bodies. This repair process occurs from stem cells in the airways and isolating these stem cells from the airways is important for understanding the mechanisms of repair and regeneration. It is also important for understanding abnormal repair that can lead to airway diseases 2. The goal of this method is to isolate a novel stem cell population from the mouse tracheal submucosal gland ducts and to place these cells in in vitro and in vivo model systems to identify the mechanisms of repair and regeneration of the submucosal glands 3. This production shows methods that can be used to isolate and assay the duct and basal stem cells from the large airways 3.This will allow us to study diseases of the airway, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease. Currently, there are no methods for isolation of submucosal gland duct cells and there are no in vivo models to study the regeneration of submucosal glands.

Here we demonstrate our protocol for isolation of basal and submucosal gland duct cells from mouse tracheas. We also demonstrate the method of injecting stem cells into the dorsal mouse fat pad to create an in vivo model of submucosal gland regeneration.

Isolierung von Basalzellen und Submuköse Gland Duct Zellen aus Maus Trachea

The large airways are directly in contact with the environment and therefore susceptible to injury from toxins and infectious agents that we breath in 1. ...

Culturing Primary Rat Inner Medullary Collecting Duct Cells

Arginine-vasopressin (AVP) facilitates water reabsorption by renal collecting duct principal cells and thereby fine-tunes body water homeostasis. AVP binds to vasopressin V2 receptors (V2R) on the surface of the cells and thereby induces synthesis of cAMP. This stimulates cellular signaling processes leading to changes in the phosphorylation of the water channel aquaporin-2 (AQP2). Protein kinase A phoshorylates AQP2 and thereby triggers the translocation of AQP2 from intracellular vesicles into the plasma membrane facilitating water reabsorption from primary urine. Aberrations of AVP release from the pituitary or AVP-activated signaling in principal cells can cause central or nephrogenic diabetes insipidus, respectively; an elevated blood plasma AVP level is associated with cardiovascular diseases such as chronic heart failure and the syndrome of inappropriate antidiuretic hormone secretion.
Here, we present a protocol for cultivation of primary rat inner medullary collecting duct (IMCD) cells, which express V2R and AQP2 endogenously. The cells are suitable for elucidating molecular mechanisms underlying the control of AQP2 and thus to discover novel drug targets for the treatment of diseases associated with dysregulation of AVP-mediated water reabsorption. IMCD cells are obtained from rat renal inner medullae and are used for experiments six to eight days after seeding. IMCD cells can be cultured in regular cell culture dishes, flasks and micro-titer plates of different formats, the procedure only requires a few hours, and is appropriate for standard cell culture laboratories.

Arginine-vasopressin (AVP) controls fine-tuning of body water homeostasis through facilitating water reabsorption by renal principal cells. Here, we present a protocol for the cultivation of primary rat inner medullary collecting duct cells suitable for the elucidation of molecular mechanisms underlying AVP-mediated water reabsorption.

Kultivierung primären Ratten Inner Medulläre Sammelkanal Cells

Arginine-vasopressin (AVP) facilitates water reabsorption by renal collecting duct principal cells and thereby fine-tunes body water homeostasis. AVP ...

Induction and Analysis of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is essential for proper morphogenesis during development. Misregulation of this process has been implicated as a key event in fibrosis and the progression of carcinomas to a metastatic state. Understanding the processes that underlie EMT is imperative for the early diagnosis and clinical control of these disease states. Reliable induction of EMT in vitro is a useful tool for drug discovery as well as to identify common gene expression signatures for diagnostic purposes. Here we demonstrate a straightforward method for the induction of EMT in a variety of cell types. Methods for the analysis of cells pre- and post-EMT induction by immunocytochemistry are also included. Additionally, we demonstrate the effectiveness of this method through antibody-based array analysis and migration/invasion assays.

A straightforward method is described for the induction of epithelial to mesenchymal transition (EMT) in a variety of cell types. Methods for the analysis of cells in EMT states by immunocytochemistry are included.

Induktion und Analyse von epithelialen zu mesenchymalen Transition

Epithelial  to mesenchymal transition (EMT) is essential for proper morphogenesis during  development. Misregulation of this  process has been implicated ...

Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of human hepatocytes is especially important in the fields of pharmacokinetics, toxicology, liver regeneration and translational research. Thus, this method presents a modified version of a two-step collagenase perfusion procedure to isolate hepatocytes as described by Seglen 1.
Previously, hepatocytes have been isolated by mechanical methods. However, enzymatic methods have been shown to be superior as hepatocytes retain their structural integrity and function after isolation. This method presented here adapts the method designed previously for rat livers to human liver pieces and results in a large yield of hepatocytes with a viability of 77&plusmn;10%. The main difference in this procedure is the process of cannulization of the blood vessels. Further, the method described here can also be applied to livers from other species with comparable liver or blood vessel sizes.

A modified two-step collagenase perfusion procedure for isolation of human hepatocytes is described. This method can also be applied to other mammalian livers. The isolated hepatocytes are available in high yield and viability, making them a suitable model for scientific research in areas such as liver regeneration, pharmacokinetics and toxicology.

Isolierung von humanen Hepatozyten durch eine Zwei-Schritt-Verfahren Collagenase Perfusion

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

In-vivo-4-Dimensional-Tracking von hämatopoetischen Stamm-und Vorläuferzellen im erwachsenen Maus Schädeldachknochenmark

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone metabolites can be detected in the feces of horses and assessment offers a non-invasive option to evaluate long term patterns of adrenal activity. Fecal assessment offers advantages over other techniques that monitor adrenal activity including blood plasma and saliva analysis. The non-invasive nature of the method avoids sampling stress which can confound results. It also allows the opportunity for repeated sampling over time and is ideal for studies in free ranging horses. This protocol describes the enzyme linked immunoassay (EIA) used to assess feces for corticosterone, in addition to the associated biochemical validation.

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. The method offers a non-invasive option to assess long term patterns in both domestic and free ranging horses. This protocol describes the enzyme linked immunoassay involved and the associated biochemical validation.

Fecal Glucocorticoid-Analyse: Nicht-invasive Monitoring-Adrenal in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis

In rodents, complete bile duct ligation (cBDL) of the common bile duct is an established surgical technique for studying obstructive cholestasis and bile duct proliferation. However, long-term experiments can lead to increased morbidity and mortality. In select mouse strains with underlying liver disease, meaningful comparisons can be made even with ligation of a single lobe of the liver, which can reduce animal losses and expenses. Here, we describe partial bile duct ligation (pBDL) in the mouse, in which only the left hepatic bile duct is ligated, causing biliary obstruction in the left lobe but not the remaining lobes. With careful microsurgical technique, pBDL experiments can be cost-effective, since the unligated lobe serves as an internal control to the ligated lobes, when subjected to the same conditions in the same animal. Unlike cBDL, a separate sham-operated control group is not necessary. pBDL is highly useful to directly compare localized versus systemic effects of cholestasis and other retained bile components. pBDL can also be repurposed as a novel method to investigate mechanisms related to medications and cell migration.

Here, we present partial bile duct ligation as a surgical model of liver injury and regeneration in rodents.

Partielle Gallengang Ligation in der Maus: eine kontrollierte Modell der lokalisierten obstruktive Cholestase

In rodents, complete bile duct ligation (cBDL) of the common bile duct is an established surgical technique for studying obstructive cholestasis and bile ...