Die Autoren danken Christiane Pahrmann für ihre technische Unterstützung und Durchführung der Histologie.

<html> Balb / C Mäuse mit einem Gewicht von mindestens 20g im Alter von 8 bis 12 Wochen sind von Charles River (Sandhofer Weg 7, D-97633 Sulzfeld) erworben. Mäuse sind unter üblichen Bedingungen, gefüttert Standard-Maus-Pellets und Wasser ad libitum untergebracht. Anesthetize Maus mit Isofluran (2%) mit einer Induktion Kammer. <ol><li> Shave Halsbereich und die linke Seite des Brustkorbs und desinfizieren mit 80% Ethanol. </li><li> Platzieren Sie die Maus auf den Rücken und legen Sie eine Gesichtsmaske über seinen Mund und Nase zu halten die Anästhesie. </li><li> Überprüfen Sie die Reflexe Einklemmen des Schwanzes und Hinterpfoten, um sicherzustellen, dass die Maus ausreichend narkotisiert ist. </li><li> Unter mikroskopischer Sicht führen Sie eine Mittellinie zervikale Inzision Trennung der Haut, Muskeln und Gewebe für die Luftröhre. </li><li> Wenn die Luftröhre freigelegt schneiden ein kleines Loch in das Gewebe zwischen zwei Patronen Ringe unterhalb der Glottis bis zu den Endotrachealtubus (Abbildung 1) einzufügen. Legen Sie die Endotrachealtubus Halten der kraniale Teil der Luftröhre mit mikrochirurgischen forecepts. Überprüfen Sie die Brust Bewegung sicher sein, dass beide Lungenflügel gut belüftet sind. </li><li> Die Atemfrequenz (RR) sollte etwa 110 pro Minute, mit einer inspiratorischen Druck von 17 bis 18cm H 2 O. Drehen Sie die Maus vorsichtig, liegt auf der rechten Seite, mit Blick auf die linke Seite. Führen Sie eine leftsided Thorakotomie zwischen dem 3. und der 4. Rippe und sezieren das Gewebe und Muskeln vorsichtig mit einem Kauter, um Blutungen zu verhindern. </li><li> Öffnen Sie den Brustkorb sorgfältig, nachdem der Brustkorb geöffnet wird, finden die Herzen, ohne die Lunge mit einem spitzen Gegenstand. Entfernen Sie nun den Teil der Herzbeutel, die für das Herz ist. </li><li> Die LAD ist zwischen Lungenarterie und dem linken Vorhof befindet. Verwenden Sie einen 8-0 Prolene Naht (Ethicon, Norderstedt, Deutschland), um die LAD proximal mit einer einzigen Naht (Abb. 2) zu unterbinden. </li><li> Legen Sie eine Thoraxdrainage (28G, käuflich Katheter), zwischen dem 4. und dem 5. Rippe. </li><li> Schließen Sie die Brust Einschnitt in Schichten mit 6-0 Prolene fortlaufenden Nähten (Ethicon, Norderstedt, Deutschland) an den Rippen und 4:0 Prolene fortlaufenden Nähten (Ethicon, Norderstedt, Deutschland) Adaption auf der Haut zu schließen. </li><li> Lassen Sie den Brustkorb mit Hilfe einer Spritze 2ml sorgfältig (Abbildung 3). Platzieren Sie die Maus auf dem Rücken. Jetzt nimmt man den Tubus aus und passen Sie die tracheale Patrone Ringe mit einem einzigen Stich mit 7-0 Prolene Fäden (Ethicon, Norderstedt, Deutschland). </li><li> Legen Sie die Maske auf der Maus und schließen Sie die Haut mit 4-0 Prolene fortlaufenden Nähten (Ethicon, Norderstedt, Deutschland). </li></ol> Bestätigung Es gibt verschiedene Möglichkeiten, um den Erfolg des LAD-Ligation zu bestätigen. Der Troponin-Test kann von 6 bis 18 Stunden nach der Operation durchgeführt werden, mit nur 150 l Blut, ohne die Notwendigkeit, das Tier einzuschläfern. Das Blut wird auf eine individuelle Troponin-Test-Kit (TROP T Sensitive, Roche, Mannheim) (Abbildung 4). Troponin ist ein regulative Protein in der Aktin-Filamente der Muskelzelle, gibt es verschiedene Isotypen in den drei Arten von Muskeln. Die Isotypen cTnI und cTnT sind im Herzen gefunden und sind in Gewebeverletzung freigesetzt. Der standardisierte Test für Troponin T (cTnT) auf zwei Herzen spezifischen monoklonalen Antikörper, einer fängt die Troponin in der Blutprobe basiert, ist der zweite Marker. Das Infarktareal kann makroskopisch nach 3 Tagen (Abbildung 5) identifiziert werden. TTC (2,3,5-Triphenyltetrazoliumchlorid) Färbung Maßnahmen Gewebeviabilität zur Infarktgröße zu bewerten. Evans blauen Farbstoff (1,5%, 1,0 ml) in Phosphat-gepufferter Salzlösung (PBS) in den linken Ventrikel injiziert, um den myokardialen ischämischen Bereich zu messen. Die Maus ist eingeschläfert und das Herz wird geerntet und geschnitten in Scheiben schneiden. Die Gewebeschnitte werden in 1% TTC PBS-Lösung, pH 7,4 bei 37 ° C für 20min inkubiert. Die Gewebe werden in 10% PBS-gepuffertem Formalin über Nacht bei 2-8 ° C fixiert TTC wird ex vivo zu färben Evans blue-negative Bereiche (Abb. 6) verabreicht werden. Für die Histologie der Maus muss eingeschläfert werden und das Herz hat für die weitere Verarbeitung eingebettet werden. Nach der Durchführung Paraffinschnitte werden Objektträger mit H &amp; E (Hämatoxylin und Eosin) gefärbten oder Trichrom zu Bindegewebe (Abb. 7) zu visualisieren. <img src="/files/ftp_upload/1438/1438fig1.jpg" alt="Abbildung 1" /> Abbildung 1: Trachealtubus. 1A: Exposed Luftröhre, nach ventral zervikalen Inzision. 1B: Trachea ist zwei Knorpelspangen kaudal des Kehlkopfes eröffnet. 1C: Trachealtubus in die Luftröhre eingeführt. <img src="/files/ftp_upload/1438/1438fig2.jpg" alt="Abbildung 2" /> Abbildung 2: Das Herz durch eine linksseitige Thorakotomie ausgesetzt ist, die LAD ligiert. t &quot;&gt; <img src="/files/ftp_upload/1438/1438fig3.jpg" alt="Abbildung 3" /> Abbildung 3: Nach dem Brustkorb geschlossen wird, eine Pleura drain durchgeführt wird. Die Maus ist immer noch unter Narkose. <img src="/files/ftp_upload/1438/1438fig4.jpg" alt="Abbildung 4" /> Abbildung 4: Zwei Linien erscheinen nach ein paar Minuten, wenn die Troponin-Test ist positiv. <img src="/files/ftp_upload/1438/1438fig5.jpg" alt="Abbildung 5" /> Abbildung 5: Zeigt die explantierten Herzen. 5A: Makroskopische Ansicht des Herzens mit den ischämischen Bereich mit einem verschossenen weißliche Farbe. 5B: Querschnitt durch den Infarkt Herz, zeigt den ischämischen Bereich in der oberen rechten Ecke.

<ol>
	<li>Atkins, B. Z., Hueman, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+cardiomyoplasty+improves+diastolic+properties+of+injured+Heart.">Cellular cardiomyoplasty improves diastolic properties of injured Heart.</a> J Surg Res. 85 (2), 234-242 (1999).</li><li>Jaquet, K., KT, K. r. a. u. s. e. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+of+myocardial+scar+size+after+implantation+of+mesenchymal+stem+cells+in+rats:+what+is+the+mechanism.">Reduction of myocardial scar size after implantation of mesenchymal stem cells in rats: what is the mechanism.</a> Stem Cells Dev. 14 (3), 299-309 (2005).</li><li>Joung, B., Kim, I. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+marrow+mononuclear+stem+cells+transplanted+in+rat+infarct+myocardium+improved+the+electrical+conduction+without+evidence+of+proarrhythmic+effects.">Bone marrow mononuclear stem cells transplanted in rat infarct myocardium improved the electrical conduction without evidence of proarrhythmic effects.</a> Yonsei Med J. 48 (5), 754-764 (2007).</li></ol>

Finanzierung Die vorliegende Studie wurde von der Universitätsklinik Hamburg (MK, Frau Habilitation Grant), DFG (SS, SCHR992/3-1), ISHLT (TD, Research Award 2009) unterstützt. Aussage Alle Tiere erhielten menschlicher Obhut in Übereinstimmung mit den Prinzipien des Laboratory Animal Care, wurden Experimente an Tieren in Übereinstimmung mit den Richtlinien und Vorschriften her von der Nationalen Gesellschaft für Medizinische Forschung und der Leitfaden für die Pflege und Verwendung von Labortieren durch die veröffentlichten durchgeführt National Institutes of Health (National Institutes of Health Veröffentlichung 85-23, revised 1985). Alle Tiere wurden von Charles River Laboratories (Sulzfeld, Deutschland) erhalten und wurden in der Tierpflege Einrichtungen des Universitätsklinikums Hamburg Eppendorf gepflegt. Die Tiere erhielten Standard-Futter und Wasser ad libitum.

Zusammenfassend visualisiert dieses Video der LAD-Ligatur-Modell Schritt-für-Schritt identifiziert und LAD-Ligation in Mäusen als leicht durchführbar chirurgischen Eingriffen.

lad-ligation: a murine model of myocardial infarction

Forschung Modelle der Infarkt und Ischämie sind unerlässlich, um die akute und chronische pathobiologischen und pathophysiologischen Prozessen in Myokardischämie zu untersuchen und zu entwickeln und zu optimieren künftige Behandlung. Zwei verschiedene Methoden zur Erstellung Myokardischämie sind in Labornagern durchgeführt. Die erste Methode ist die Kryo-Infarkt, eine schnelle, aber ungenaue Methode, wo ein Kryo-Stift auf der Oberfläche des Herzens (1-3) angewendet wird, zu schaffen. Mit dieser Methode kann der Wissenschaftler nicht garantieren, dass die Kryo-Narbe Ischämie führt, auch eine große Myokardschäden erstellt, zeigt pathophysiologischen Nebenwirkungen, die nicht auf Herzinfarkt in Zusammenhang stehen. Die zweite Methode ist die permanente Ligation der linken vorderen absteigenden Arterie (LAD). Hier werden die LAD ist mit einem einzigen Stich ligiert und bilden eine Ischämie, die fast sofort gesehen werden kann. Durch das Schließen der LAD, sind keine weiteren Blutfluss in diesem Bereich nicht erlaubt, während die umgebenden Herzmuskelgewebe ist fast nicht betroffen. Dieses chirurgische Verfahren ahmt die pathobiologischen und pathophysiologische Aspekte auftretenden Infarkt-bezogenen Myokardischämie. Die Methode in diesem Video vorgestellt zeigt den chirurgischen Eingriff einer Maus Infarkt Modell durch Ligation der LAD. Dieses Modell ist für pathobiologischen und pathophysiologischen sowie immunbiologische Studien über Herzinfarkt bequem. Die gezeigten Technik bietet eine hohe Genauigkeit und korreliert gut mit histologischen Schnitten.

Watch this Scientific Journal Video about LAD-Ligation: A Murine Model of Myocardial Infarction at JoVE.com

LAD-Ligation: A Murine Model of Myocardial Infarction

Dieses Video zeigt, wie eine schnelle und zuverlässige Modell nutzen, um pathobiologischen und pathophysiologischen Prozessen der Myokardischämie zu studieren.

LAD-Ligation: einem Mausmodell der Myokardinfarkt

Research models of infarction and myocardial ischemia are essential to investigate the acute and chronic pathobiological and pathophysiological processes ...

lad-ligation-a-murine-model-of-myocardial-infarction

Research

JoVE Journal

Biology

44.4K Aufrufe.  University Heart Center Hamburg. Dieses Video zeigt, wie eine schnelle und zuverlässige Modell nutzen, um pathobiologischen und pathophysiologischen Prozessen der Myokardischämie zu studieren.

Serie: LAD-Ligation: A Murine Model of Myocardial Infarction

Murine Pancreatic Islet Isolation

Murine Inselzellen der Bauchspeicheldrüse Isolation

Forschung

Biologie

Murine Model of Hindlimb Ischemia 

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide. Medical therapies for symptomatic relief are limited. Surgical or endovascular interventions are useful for some individuals, but long-term results are often disappointing. As a result, there is a need for developing new therapies to treat PAD. The murine hindlimb ischemia preparation is a model of PAD, and is useful for testing new therapies. When compared to other models of tissue ischemia such as coronary or cerebral artery ligation, femoral artery ligation provides for a simpler model of ischemic tissue. Other advantages of this model are the ease of access to the femoral artery and low mortality rate. 
In this video, we demonstrate the methodology for the murine model of unilateral hindimb ischemia. The specific materials and procedures for creating and evaluating the model will be described, including the assessment of limb perfusion by laser Doppler imaging. This protocol can also be utilized for the transplantation and non-invasive tracking of cells, which is demonstrated by Huang et al.1.

Murine Model of Hindlimb Ischemia

The surgical procedure for induction of unilateral hindlimb ischemia is demonstrated, with confirmation of ischemia by laser Doppler perfusion imaging.

Mausmodell der hinteren Gliedmaßen Ischämie

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide.  Medical therapies for ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Murine Renal Transplantation

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways that cannot be accomplished in vivo. For example, inotropic medications commonly also affect preload and afterload, precluding load-independent assessments of their myocardial effects in vivo. Additionally, this model allows for sampling of coronary sinus effluent without contamination from systemic venous return, permitting assessment of myocardial oxygen consumption. Further, the advent of miniaturized pressure-volume catheters has allowed for the precise quantification of markers of both systolic and diastolic performance. We describe a model in which the left ventricle can be studied while performing both volume and pressure work under controlled conditions. 
In this technique, the heart and lungs of a Sprague-Dawley rat (weight 300-500 g) are removed en bloc under general anesthesia. The aorta is dissected free and cannulated for retrograde perfusion with oxygenated Krebs buffer. The pulmonary arteries and veins are ligated and the lungs removed from the preparation. The left atrium is then incised and cannulated using a separate venous cannula, attached to a preload block. Once this is determined to be leak-free, the left heart is loaded and retrograde perfusion stopped, creating the working heart model. The pulmonary artery is incised and cannulated for collection of coronary effluent and determination of myocardial oxygen consumption. A pressure-volume catheter is placed into the left ventricle either retrograde or through apical puncture. If desired, atrial pacing wires can be placed for more precise control of heart rate. This model allows for precise control of preload (using a left atrial pressure block), afterload (using an afterload block), heart rate (using pacing wires) and oxygen tension (using oxygen mixtures within the perfusate).

Isolated working heart models can be used to measure the effect of loading conditions, heart rate, and medications on myocardial performance and oxygen consumption. We describe methods for preparation of a rodent left heart working model that permits study of systolic and diastolic performance and oxygen consumption under various conditions.

Nagetier Arbeits Herz Modell für die Untersuchung der myokardialen Leistung und Sauerstoffverbrauch

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways ...

The Murine Choline-Deficient, Ethionine-Supplemented (CDE) Diet Model of Chronic Liver Injury

Chronic liver diseases, such as viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease, are characterized by continual inflammation, progressive destruction and regeneration of the hepatic parenchyma, liver progenitor cell proliferation, and fibrosis. The end-stage of every chronic liver disease is cirrhosis, a major risk factor for the development of hepatocellular carcinoma. To study processes regulating disease initiation, establishment, and progression, several animal models are used in laboratories. Here we describe a six-week time course of the choline-deficient and ethionine-supplemented (CDE) mouse model, which involves feeding six-week old male C57BL/6J mice with choline-deficient chow and 0.15% DL-ethionine-supplemented drinking water. Monitoring of animal health and a typical body weight loss curve are explained. The protocol demonstrates the gross examination of a CDE-treated liver and blood collection by cardiac puncture for subsequent serum analyses. Next, the liver perfusion technique and collection of different hepatic lobes for standard evaluations are shown, including liver histology assessments by hematoxylin and eosin or Sirius Red stainings, immunofluorescent detection of hepatic cell populations as well as transcriptome profiling of the liver microenvironment. This mouse model is suitable for studying inflammatory, fibrogenic, and liver progenitor cell dynamics induced through chronic liver disease and can be used to test potential therapeutic agents that may modulate these processes.

The Murine Choline-Deficient, Ethionine-Supplemented CDE Diet Model of Chronic Liver Injury

Here we describe a common method to induce chronic liver injury in mice by feeding of a choline-deficient and ethionine-supplemented (CDE) diet. We demonstrate health monitoring, liver perfusion, isolation, and preservation. A time course of six weeks can inform about liver injury, pathohistology, fibrosis, inflammatory, and liver progenitor cell responses.

Der murinen Cholin-Mangel, Ethionine ergänzt (CDE) Diät-Modell einer chronischen Leberschädigung

Chronic liver diseases, such as viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease, are characterized by continual ...

A Murine Model of Vertical Sleeve Gastrectomy

Bariatric surgery, such as vertical sleeve gastrectomy (VSG), is a surgery of the gastrointestinal tract that is performed for the purpose of weight loss. Bariatric surgery is currently the most effective long-term treatment for obesity. In addition to weight loss, bariatric surgery produces additional health benefits such as remission of type 2 diabetes, remission of hypertension, and decreased risk of developing certain types of cancer. The mechanisms beyond weight loss for these benefits remain incompletely defined. Therefore, animal models of bariatric surgery are being developed and validated to identify the mechanisms leading to these benefits, with the goal of improving understanding of gastrointestinal physiology and identifying new therapeutic targets. VSG has become the most commonly performed bariatric procedure in the clinic in the United States because it is highly effective at producing weight loss and metabolic improvement, and is simpler to perform than other bariatric procedures. Therefore, we have developed and validated a murine model of VSG. This murine VSG model recapitulates many of the effects of VSG seen in humans, including improved glucose and blood pressure regulation. The method is based on isolation of the stomach, ligation of gastric vessels, and removal of 70% of the stomach by transecting along the greater curvature of the stomach. We have successfully applied this surgical protocol to various genetically modified mouse lines to define the mechanistic contributors to the benefits of VSG. Furthermore, this murine VSG model has been combined with other surgical techniques, to achieve deeper mechanistic insight. Therefore, this is a simple and versatile model for studying gastrointestinal physiology and the health benefits of bariatric surgery.

The following describes the performance of vertical sleeve gastrectomy in mice. This is a type of weight-loss surgery that involves removal of approximately 70% of the stomach.

Ein Mausmodell der vertikalen Sleeve-Gastrektomie

Bariatric surgery, such as vertical sleeve gastrectomy (VSG), is a surgery of the gastrointestinal tract that is performed for the purpose of weight loss. ...

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer progression. How the chromosomal location and function of a centromere (i.e., centromere identity) are determined and participate in accurate chromosome segregation is a fundamental question. CENP-A is proposed to be the non-DNA indicator (epigenetic mark) of centromere identity, and CENP-A ubiquitylation is required for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability.
Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-CENP-A K124R mutant suggesting that ubiquitylation at a different lysine is induced because of the EYFP tagging in the CENP-A K124R mutant protein. Lysine 306 (K306) ubiquitylation in EYFP-CENP-A K124R was successfully identified, which corresponds to lysine 56 (K56) in CENP-A through mass spectrometry analysis. A caveat is discussed in the use of GFP/EYFP or the tagging of high molecular weight protein as a tool to analyze the function of a protein. Current technical limit is also discussed for the detection of ubiquitylated bands, identification of site-specific ubiquitylation(s), and visualization of ubiquitylation in living cells or a specific single cell during the whole cell cycle.
The method of mass spectrometry analysis presented here can be applied to human CENP-A protein with different tags and other centromere-kinetochore proteins. These combinatory methods consisting of several assays/analyses could be recommended for researchers who are interested in identifying functional roles of ubiquitylation.

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A EYFP-CENP-A

CENP-A ubiquitylation is an important requirement for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability. Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A) protein.

Massenspektrometrieanalyse zur Identifizierung der Ubiquitylierung von EIFP-A mit EYFP-Tags (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer ...

A Murine Model of a Burn Wound Reconstructed with an Allogeneic Skin Graft

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and require surgical debridement and skin grafting. Successful integration of the donor graft into a recipient wound bed depends on timely recruitment of immune cells, robust angiogenic response and new extracellular matrix formation. The development of novel therapeutic agents, which target some key processes involved in wound healing, are hindered by the lack of reliable preclinical models with optimized objective assessment of wound closure. Here, we describe an inexpensive and reproducible model of experimental full thickness burn wound reconstructed with an allogeneic skin graft. The wound is induced on the dorsum surface of anaesthetized inbred wild type mice from the BALB/C and SKH1-Hrhr backgrounds. The burn is produced using a brass template measuring 10 mm in diameter, which is preheated to 80 &#176;C and delivered at a constant pressure for 20 s. Burn eschar is excised 24 hours after the injury and replaced with a full thickness graft harvested from the tail of a genetically similar donor mouse. No specialized equipment is required for the procedure and surgical techniques are straightforward to follow. The method may be effortlessly implemented and reproduced in most research settings. Certain limitations are associated with the model. Due to technical difficulties, the harvest of thinner split thickness skin grafts is not possible. The surgical method we describe here allows for the reconstruction of burn wounds using full thickness skin grafts. It may be used to carry out preclinical therapeutic testing.

The aim of this study was to develop a murine model of burn wound healing. A thermal burn was induced on the dorsal skin of mice using a preheated brass template. Burned tissue was debrided and overlaid with a skin graft harvested from the tail of a genetically similar donor mouse.

Ein murines Modell einer Verbranntenwunde, rekonstruiert mit einem allogenen Hautgraft

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and ...

The Establishment of a Murine Mandibular Molar Extraction Socket Healing Model

This study introduces the development of a molar extraction model in the murine mandible to provide a practicable model for studying alveolar bone regeneration and intramembranous ossification. C57/J6 mice were used to extract the mandibular first molar to establish this model. They were euthanized, and the bilateral mandibles harvested, at 1 week and 4 weeks post-surgery, respectively. Subsequent serial stereoscopic harvest, histological assessment, and immunofluorescence staining were performed to demonstrate successful surgery. Immediately after surgery, the stereoscopic images displayed an empty extraction socket. The hematoxylin and eosin (H&#38;E) at 1 week and Masson staining at 4 weeks post-surgery showed that the area of the original root was partially and fully filled with bone trabeculae, respectively. The immunofluorescence staining showed that, compared with the homeostasis side, the Sp7 expression increased at 1 week post-surgery, suggesting vigorous osteogenesis in the alveolar fossa. All these results demonstrated a practicable murine tooth extraction socket healing model. Upcoming studies revealing the mechanisms of jawbone defect healing or socket healing could adopt this method.

This protocol demonstrates step-by-step details of how to extract the mandibular first molar in the mouse. It provides an alternative method for researchers focusing on jawbone healing and regeneration.

Die Etablierung eines murinen murinen molaren Extraktionsalveolen-Heilungsmodells

This study introduces the development of a molar extraction model in the murine mandible to provide a practicable model for studying alveolar bone ...

Erforschung der HR-abhängigen Herzleistung mit Hilfe eines atrialen Stimulationsprotokolls

A Pacing-Controlled Procedure for the Assessment of Heart Rate-Dependent Diastolic Functions in Murine Heart Failure Models

Heart failure with preserved ejection fraction (HFpEF) is a condition characterized by diastolic dysfunction and exercise intolerance. While exercise-stressed hemodynamic tests or MRI can be used to detect diastolic dysfunction and diagnose HFpEF in humans, such modalities are limited in basic research using mouse models. A treadmill exercise test is commonly used for this purpose in mice, but its results can be influenced by body weight, skeletal muscle strength, and mental state. Here, we describe an atrial-pacing protocol to detect heart rate (HR)-dependent changes in diastolic performance and validate its usefulness in a mouse model of HFpEF. The method involves anesthetizing, intubating, and performing pressure-volume (PV) loop analysis concomitant with atrial pacing. In this work, a conductance catheter was inserted via a left ventricular apical approach, and an atrial pacing catheter was placed in the esophagus. Baseline PV loops were collected before the HR was slowed with ivabradine. PV loops were collected and analyzed at HR increments ranging from 400 bpm to 700 bpm via atrial pacing. Using this protocol, we clearly demonstrated HR-dependent diastolic impairment in a metabolically induced HFpEF model. Both the relaxation time constant (Tau) and the end-diastolic pressure-volume relationship (EDPVR) worsened as the HR increased compared to control mice. In conclusion, this atrial pacing-controlled protocol is useful for detecting HR-dependent cardiac dysfunctions. It provides a new way to study the underlying mechanisms of diastolic dysfunction in HFpEF mouse models and may help develop new treatments for this condition.

Autor im Rampenlicht: Untersuchung der HR-abhängigen Herzfunktion in Mausmodellen durch einen neuartigen atrialen Stimulationsansatz 

The present protocol describes obtaining the pressure-volume relationship through transesophageal pacing, which serves as a valuable tool in evaluating diastolic function&#160;in mouse models of heart failure.