GHK is supported by NIH/NHLBI K08-HL098565 and the Institute for Cardiovascular Research at the University of Chicago. All experimental methods described are approved by the Institutional Animal Care and Use Committee at the University of Chicago.

1. Preparing Mice for Imaging
<ol>
	<li>Prior to the imaging study, anesthetize the dam (2-3% isoflurane) in the induction chamber. Remove the animal from the induction chamber and immediately place the snout within a nose cone connected to the anesthesia system. Remove fur from the mid chest level to lower limbs (See Figure 1) with hair clippers. Remove the remaining body hair with depilatory cream. Depilatory cream may also be used without hair clippers, and should be thoroughly rinsed off of the ski...

<ol>
	<li>Wessels, A., Sedmera, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+anatomy+of+the+heart:+a+tale+of+mice+and+man.">Developmental anatomy of the heart: a tale of mice and man.</a> Physiol. Genomics. 15, 165 (2003).</li><li>Snider, P., Conway, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+human+cardiovascular+congenital+disease+using+transgenic+mouse+models.">Probing human cardiovascular congenital disease using transgenic mouse models.</a> Prog. Mol. Biol. Transl. Sci. 100, 83 (2011).</li><li>Clark, K. L., Yutzey, K. E., Benson, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcription+factors+and+congenital+heart+defects.">Transcription factors and congenital heart defects.</a> Annu. Rev. Physiol. 68, 97 (2006).</li><li>Leatherbury, L., Yu, Q., Lo, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+phenotypic+analysis+of+cardiovascular+structure+and+function+in+fetal+mice+using+ultrasound.">Noninvasive phenotypic analysis of cardiovascular structure and function in fetal mice using ultrasound.</a> Birth Defects Res C Embryo Today. 69, 83 (2003).</li><li>Spurney, C. F., Lo, C. W., Leatherbury, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fetal+mouse+imaging+using+echocardiography:+a+review+of+current+technology.">Fetal mouse imaging using echocardiography: a review of current technology.</a> Echocardiography. 23, 891 (2006).</li><li>Spurney, C. F., Leatherbury, L., Lo, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-frequency+ultrasound+database+profiling+growth,+development,+and+cardiovascular+function+in+C57BL/6J+mouse+fetuses.">High-frequency ultrasound database profiling growth, development, and cardiovascular function in C57BL/6J mouse fetuses.</a> J. Am. Soc. Echocardiogr. 17, 893 (2004).</li><li>Shen, Y., 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=Cardiovascular+phenotyping+of+fetal+mice+by+noninvasive+high-frequency+ultrasound+facilitates+recovery+of+ENU-induced+mutations+causing+congenital+cardiac+and+extracardiac+defects.">Cardiovascular phenotyping of fetal mice by noninvasive high-frequency ultrasound facilitates recovery of ENU-induced mutations causing congenital cardiac and extracardiac defects.</a> Physiol. Genomics. 24, 23 (2005).</li><li>Yu, Q., Leatherbury, L., Tian, X., Lo, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+assessment+of+fetal+mice+by+in+utero+echocardiography.">Cardiovascular assessment of fetal mice by in utero echocardiography.</a> Ultrasound Med. Biol. 34, 741 (2008).</li><li>Linask, K. K., Huhta, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Doppler+echocardiography+to+monitor+embryonic+mouse+heart+function.">Use of Doppler echocardiography to monitor embryonic mouse heart function.</a> Methods Mol. Biol. 135, 245 (2000).</li><li>Hinton, R. B., 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=Mouse+heart+valve+structure+and+function:+echocardiographic+and+morphometric+analyses+from+the+fetus+through+the+aged+adult.">Mouse heart valve structure and function: echocardiographic and morphometric analyses from the fetus through the aged adult.</a> Am. J. Physiol Heart Circ. Physiol. 294, H2480 (2008).</li><li>Gui, Y. H., Linask, K. K., Khowsathit, P., Huhta, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doppler+echocardiography+of+normal+and+abnormal+embryonic+mouse+heart.">Doppler echocardiography of normal and abnormal embryonic mouse heart.</a> Pediatr. Res. 40, 633 (1996).</li><li>Purssell, E., 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=Noninvasive+high-resolution+ultrasound+reveals+structural+and+functional+deficits+in+dimethadione-exposed+fetal+rat+hearts+in+utero.">Noninvasive high-resolution ultrasound reveals structural and functional deficits in dimethadione-exposed fetal rat hearts in utero.</a> Birth Defects Res. B Dev. Reprod. Toxicol. , (2011).</li><li>Le, V. P., Kovacs, A., Wagenseil, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+Left+Ventricular+Pressure+in+Late+Embryonic+and+Neonatal+Mice.">Measuring Left Ventricular Pressure in Late Embryonic and Neonatal Mice.</a> J. Vis. Exp. (60), e3756 (2012).</li><li>Ji, R. P., Phoon, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+localization+of+nuclear+factor+of+activated+T+cells+c1-/-+mouse+embryos+by+ultrasound+biomicroscopy-Doppler+allows+genotype-phenotype+correlation.">Noninvasive localization of nuclear factor of activated T cells c1-/- mouse embryos by ultrasound biomicroscopy-Doppler allows genotype-phenotype correlation.</a> J. Am. Soc. Echocardiogr. 18, 1415 (2005).</li><li>Kim, G. H., Samant, S. A., Earley, J. U., Svensson, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Translational+control+of+FOG-2+expression+in+cardiomyocytes+by+microRNA-130a.">Translational control of FOG-2 expression in cardiomyocytes by microRNA-130a.</a> PLoS One. 4, e6161 (2009).</li><li>Momoi, N., 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=Modest+maternal+caffeine+exposure+affects+developing+embryonic+cardiovascular+function+and+growth.">Modest maternal caffeine exposure affects developing embryonic cardiovascular function and growth.</a> Am. J. Physiol. Heart Circ. Physiol. 294, H2248 (2008).</li><li>Tobita, K., Liu, X., Lo, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+modalities+to+assess+structural+birth+defects+in+mutant+mouse+models.">Imaging modalities to assess structural birth defects in mutant mouse models.</a> Birth Defects Res. C Embryo Today. 90, 176 (2010).</li></ol>

The ability to perform serial measurements and to detect mutant fetuses with cardiac defects highlights the usefulness of echocardiography for investigating normal and abnormal cardiovascular development. Analysis of cardiac structure and function in vivo has become an integral part in the description of genetic and non-genetic modifications to normal fetal development. The availability of 2D-guided Doppler makes it possible to monitor heart rate and blood flow patterns while obtaining real-time images. De...

<table border="1">
<tbody>
 <tr>
 <td>Vevo 770 Imaging System</td>
 <td>VisualSonics</td>
 <td></td>
 <td>(Toronto, Canada)</td>
 </tr>
 <tr>
 <td>RMV707B.15-45 MHz transducer</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Tec 3 Isoflurane Vaporizer</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Isoflurane (2-chloro-2-(difluoromethoxy)-1,1,1-trifluoro-ethane)</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 </tbody>
</table>

murine fetal echocardiography

Transgenic mice displaying abnormalities in cardiac development and function represent a powerful tool for the understanding the molecular mechanisms underlying both normal cardiovascular function and the pathophysiological basis of human cardiovascular disease. Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development 1-3. In order to study the role of genetic or pharmacologic alterations in the early development of cardiac function, ultrasound imaging of the live fetus has become an important tool for early recognition of abnormalities and longitudinal follow-up. Noninvasive ultrasound imaging is an ideal method for detecting and studying congenital malformations and the impact on cardiac function prior to death 4. It allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies 5,6. Until recently, imaging of fetal mouse hearts frequently involved invasive methods. The fetus had to be sacrificed to perform magnetic resonance microscopy and electron microscopy or surgically delivered for transillumination microscopy. An application of high-frequency probes with conventional 2-D and pulsed-wave Doppler imaging has been shown to provide measurements of cardiac contraction and heart rates during embryonic development with databases of normal developmental changes now available 6-10. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. High-frequency ultrasound imaging of the fetus has improved 2-D resolution and can provide excellent information on the early development of cardiac structures 11.

Watch this Scientific Journal Video about Murine Fetal Echocardiography at JoVE.com

Murine Fetal Echocardiography

Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to death.

Transgenic mice displaying abnormalities in  cardiac development and function represent a powerful tool for the understanding  the molecular mechanisms ...

Research

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Medicine

17.0K ビュー.  University of Chicago. 心臓の発達に影響を与える遺伝的変化を検討する際に、胎児および周産期死亡は、一般的な機能です。高周波超音波イメージングは​​、2次元の解像度を向上しており、早期に心臓の開発に優れた情報を提供することができますし、死亡前に心臓の構造と機能に及ぼす影響を検出するための理想的な方法です。

ビデオ: Murine Fetal Echocardiography

Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development. High-frequency ultrasound imaging has improved 2-D resolution and can provide excellent information on early cardiac development and is an ideal method to detect the impact on cardiac structure and function prior to...

fetal mouse cardiovascular imaging using a high-frequency ultrasound (30/45mhz) system

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound 30/45MHZ System

High-frequency ultrasound imaging of the fetal mouse has improved imaging resolution and can provide precise non-invasive characterization of cardiac development and structural defects. The protocol outlined herein is designed to perform real-time fetal mice echocardiography in...

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System

ultrasonography in experimental reproductive investigations on rats

Ultrasonography in Experimental Reproductive Investigations on Rats

This manuscript describes the utility of ultrasound performed on female rats to design experimental models for reproductive and gynecological investigation. A step-by-step explanation of how to perform ultrasonographic evaluation is...

murine echocardiography and ultrasound imaging

Murine Echocardiography and Ultrasound Imaging

This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse.  The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast...

murine echocardiography of left atrium, aorta, and pulmonary artery

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary...

fetal echocardiography and pulsed-wave doppler ultrasound in a rabbit model of intrauterine growth restriction

Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction

We describe examination of fetal cardiac function with contemporary functional fetal echocardiography and fetoplacental Doppler ultrasound using the VisualSonics VEVO 2100 microultrasound in a surgically induced model of intrauterine fetal growth restriction in a...

culturing and measuring fetal and newborn murine long bones

Culturing and Measuring Fetal and Newborn Murine Long Bones

Here, we present a method for ex vivo culture of long murine bones at both fetal and newborn stages, suitable for analyzing bone and cartilage development and homeostasis in controlled conditions while recapitulating the in vivo...

mouse echocardiography: a non-invasive technique to assess cardiac morphology

This video describes a protocol to perform echocardiography on a laboratory...

Mouse Echocardiography: A Non-invasive Technique to Assess Cardiac Morphology

transthoracic echocardiography in mice

Transthoracic Echocardiography in Mice

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic...

isolation of leukocytes from the murine tissues at the maternal-fetal interface

Isolation of Leukocytes from the Murine Tissues at the Maternal-Fetal Interface

Described herein is a protocol to isolate and analyze the infiltrating leukocytes of tissues at the maternal-fetal interface (uterus, decidua, and placenta) of mice. This protocol maintains the integrity of most cell surface markers and yields enough viable cells for downstream applications including flow cytometry analysis.

modeling transuterine fetal tracheal occlusion in murine model: a surgical procedure for ligation of the fetal trachea within a pregnant mouse

This video demonstrates the transuterine tracheal occlusion procedure of a mouse fetus in a pregnant mouse. This model can be used to study the impact of occluded trachea on lung...

Modeling Transuterine Fetal Tracheal Occlusion in Murine Model: A Surgical Procedure for Ligation of the Fetal Trachea Within a Pregnant Mouse

Operate on two fetuses in each uterine horn if there is an even number of fetuses on each side, and on one fetus in each uterine horn if there is an odd number. Using 2x magnification glasses for visualization, position the uterine horn in a transverse fashion. Position the pups facing upward between two fingers using the eyes and the tail as a...

echocardiography recording in awake miniature pigs

Echocardiography Recording in Awake Miniature Pigs

A simple cart construct, built to perform research echocardiography in standing awake minipigs, is described, along with building considerations, training techniques, and representative ultrasound images.

2d and 3d echocardiography in the axolotl (ambystoma mexicanum)

2D and 3D Echocardiography in the Axolotl Ambystoma Mexicanum

Here we present echocardiography protocols for two-dimensional and three-dimensional image acquisition of the beating heart of the axolotl salamander (Ambystoma mexicanum), a model species in heart regeneration. These methods allow for longitudinal evaluation of cardiac function at a high spatiotemporal...

2D and 3D Echocardiography in the Axolotl (Ambystoma Mexicanum)

high-frequency high-resolution echocardiography: first evidence on non-invasive repeated measure of myocardial strain, contractility, and mitral regurgitation in the ischemia-reperfused murine heart

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine...

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

noninvasive determination of vortex formation time using transesophageal echocardiography during cardiac surgery

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

We describe a protocol to measure vortex formation time, an index of left ventricular filling efficiency, using standard transesophageal echocardiography techniques in patients undergoing cardiac surgery. We apply this technique to analyze vortex formation time in several groups of patients with differing cardiac...

a pipeline to characterize structural heart defects in the fetal mouse

A Pipeline to Characterize Structural Heart Defects in the Fetal Mouse

This article details murine congenital heart disease (CHD) diagnostic methods using fetal echocardiography, necropsy, and Episcopic fluorescence image capture (EFIC) using Episcopic confocal microscopy (ECM) followed by three-dimensional (3D)...

a murine model of fetal exposure to maternal inflammation to study the effects of acute chorioamnionitis on newborn intestinal development

A Murine Model of Fetal Exposure to Maternal Inflammation to Study the Effects of Acute Chorioamnionitis on Newborn Intestinal Development

We developed a model of chorioamnionitis to simulate fetal exposure to maternal inflammation (FEMI) without complications of live organisms to examine the effects of FEMI on development of the offspring&#8217;s intestinal tract. This allows for study of mechanistic causes for development of intestinal injury following...

high-frequency ultrasound echocardiography to assess zebrafish cardiac function

High-Frequency Ultrasound Echocardiography to Assess Zebrafish Cardiac Function

We describe a protocol to assess heart morphology and function in adult zebrafish using high-frequency echocardiography. The method allows visualization of the heart and subsequent quantification of functional parameters, such as heart rate (HR), cardiac output (CO), fractional area change (FAC), ejection fraction (EF), and blood inflow and outflow...

morphological and functional assessment of the right ventricle using 3d echocardiography

Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography

Here, we provide a step-by-step acquisition and analysis protocol for the 3D volumetric assessment of the right ventricle, mainly focusing on the practical aspects that maximize the feasibility of this...

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,6 whereas TDI is used to measure the velocity of myocardial motion.7 Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene ...

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized.  The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed. 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine heart.

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1 Echocardiography provides a powerful, non-invasive tool to serially assess cardiac morphometry and function in a living animal.2 However, using this technique on mice poses unique challenges owing to the small size and rapid heart rate of these animals.3 Until recently, few ultrasound systems were capable of performing quality echocardiography on mice, and those generally lacked the image resolution and frame rate necessary to obtain truly quantitative measurements. Newly released systems such as the VisualSonics Vevo2100 provide new tools for researchers to carefully and non-invasively investigate cardiac function in mice. This system generates high resolution images and provides analysis capabilities similar to those used with human patients. Although color Doppler has been available for over 30 years in humans, this valuable technology has only recently been possible in rodent ultrasound.4,5 Color Doppler has broad applications for echocardiography, including the ability to quickly assess flow directionality in vessels and through valves, and to rapidly identify valve regurgitation. Strain analysis is a critical advance that is utilized to quantitatively measure regional myocardial function.6 This technique has the potential to detect changes in pathology, or resolution of pathology, earlier than conventional techniques. Coupled with the addition of three-dimensional image reconstruction, volumetric assessment of whole-organs is possible, including visualization and assessment of cardiac and vascular structures. Murine-compatible contrast imaging can also allow for volumetric measurements and tissue perfusion assessment.

This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse. The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast imaging.

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1  ...

Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue2. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study3-8. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model.

In order to understand the molecular mechanisms of the ethanol-induced developmental damage, we have developed a zebrafish model of ethanol exposure and are exploring the physical, cellular, and genetic alterations that occur after ethanol exposure1. We then seek to find potential interventions and rapidly test them in this animal model.

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, ...

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ultrasound and fetal echocardiography. Increasingly, these imaging modalities are being employed clinically to examine cardiac function and assess wellbeing in utero, thereby guiding timing of birth decisions. Here, we used a rabbit model of IUGR that allows analysis of cardiac function in a clinically relevant way. Using isoflurane induced anesthesia, IUGR is surgically created at gestational age day 25 by performing a laparotomy, exposing the bicornuate uterus and then ligating 40-50% of uteroplacental vessels supplying each gestational sac in a single uterine horn. The other horn in the rabbit bicornuate uterus serves as internal control fetuses. Then, after recovery at gestational age day 30 (full term), the same rabbit undergoes examination of fetal cardiac function. Anesthesia is induced with ketamine and xylazine intramuscularly, then maintained by a continuous intravenous infusion of ketamine and xylazine to minimize iatrogenic effects on fetal cardiac function. A repeat laparotomy is performed to expose each gestational sac and a microultrasound examination (VisualSonics VEVO 2100) of fetal cardiac function is performed. Placental insufficiency is evident by a raised pulsatility index or an absent or reversed end diastolic flow of the umbilical artery Doppler waveform. The ductus venosus and middle cerebral artery Doppler is then examined. Fetal echocardiography is performed by recording B mode, M mode and flow velocity waveforms in lateral and apical views. Offline calculations determine standard M-mode cardiac variables, tricuspid and mitral annular plane systolic excursion, speckle tracking and strain analysis, modified myocardial performance index and vascular flow velocity waveforms of interest. This small animal model of IUGR therefore affords examination of in utero cardiac function that is consistent with current clinical practice and is therefore useful in a translational research setting.

We describe examination of fetal cardiac function with contemporary functional fetal echocardiography and fetoplacental Doppler ultrasound using the VisualSonics VEVO 2100 microultrasound in a surgically induced model of intrauterine fetal growth restriction in a rabbit.

Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ...

Isolation, Culture, and Imaging of Human Fetal Pancreatic Cell Clusters

For almost 30 years, scientists have demonstrated that human fetal ICCs transplanted under the kidney capsule of nude mice matured into functioning endocrine cells, as evidenced by a significant increase in circulating human C-peptide following glucose stimulation1-9. However in vitro, genesis of insulin producing cells from human fetal ICCs is low10; results reminiscent of recent experiments performed with human embryonic stem cells (hESC), a renewable source of cells that hold great promise as a potential therapeutic treatment for type 1 diabetes. Like ICCs, transplantation of partially differentiated hESC generate glucose responsive, insulin producing cells, but in vitro genesis of insulin producing cells from hESC is much less robust11-17. A complete understanding of the factors that influence the growth and differentiation of endocrine precursor cells will likely require data generated from both ICCs and hESC. While a number of protocols exist to generate insulin producing cells from hESC in vitro11-22, far fewer exist for ICCs10,23,24. Part of that discrepancy likely comes from the difficulty of working with human fetal pancreas. Towards that end, we have continued to build upon existing methods to isolate fetal islets from human pancreases with gestational ages ranging from 12 to 23 weeks, grow the cells as a monolayer or in suspension, and image for cell proliferation, pancreatic markers and human hormones including glucagon and C-peptide. ICCs generated by the protocol described below result in C-peptide release after transplantation under the kidney capsule of nude mice that are similar to C-peptide levels obtained by transplantation of fresh tissue6. Although the examples presented here focus upon the pancreatic endoderm proliferation and &#946;&#160;cell genesis, the protocol can be employed to study other aspects of pancreatic development, including exocrine, ductal, and other hormone producing cells.

A protocol to isolate, culture, and image islet cell clusters (ICCs) derived from human fetal pancreatic cells is described.&#160; The method details the steps necessary to generate ICCs from tissue, culture as monolayers or in suspension as aggregates, and image for markers of proliferation and pancreatic cell fate decisions.

For almost 30 years, scientists have demonstrated that human fetal ICCs transplanted under the kidney capsule of nude mice matured into functioning ...

In utero Measurement of Heart Rate in Mouse by Noninvasive M-mode Echocardiography

Congenital heart disease (CHD) is the most frequent noninfectious cause of death at birth. The incidence of CHD ranges from 4 to 50/1,000 births (Disease and injury regional estimates, World Health Organization, 2004). Surgeries that often compromise the quality of life are required to correct heart defects, reminding us of the importance of finding the causes of CHD. Mutant mouse models and live imaging technology have become essential tools to study the etiology of this disease. Although advanced methods allow live imaging of abnormal hearts in embryos, the physiological and hemodynamic states of the latter are often compromised due to surgical and/or lengthy procedures. Noninvasive ultrasound imaging, however, can be used without surgically exposing the embryos, thereby maintaining their physiology. Herein, we use simple M-mode ultrasound to assess heart rates of embryos at E18.5 in utero. The detection of abnormal heart rates is indeed a good indicator of dysfunction of the heart and thus constitutes a first step in the identification of developmental defects that may lead to heart failure.

In utero Measurement of Heart Rate in Mouse by Noninvasive M-mode Echocardiography

Ultra-high frequency ultrasound is a powerful live imaging tool to examine cardiac abnormalities in small animals. Its noninvasiveness allows maintaining the physiologic state of embryos. Herein, we show the use of M-mode ultrasound to measure the heart rates of embryos at E18.5 in utero.

Congenital heart disease (CHD) is the most frequent noninfectious cause of death at birth. The incidence of CHD ranges from 4 to 50/1,000 births (Disease ...

A Mouse Fetal Skin Model of Scarless Wound Repair

Early in utero, but not in postnatal life, cutaneous wounds undergo regeneration and heal without formation of a scar. Scarless fetal wound healing occurs across species but is age dependent. The transition from a scarless to scarring phenotype occurs in the third trimester of pregnancy in humans and around embryonic day 18 (E18) in mice. However, this varies with the size of the wound with larger defects generating a scar at an earlier gestational age. The emergence of lineage tracing and other genetic tools in the mouse has opened promising new avenues for investigation of fetal scarless wound healing. However, given the inherently high rates of morbidity and premature uterine contraction associated with fetal surgery, investigations of fetal scarless wound healing in vivo require a precise and reproducible surgical model. Here we detail a reliable model of fetal scarless wound healing in the dorsum of E16.5 (scarless) and E18.5 (scarring) mouse embryos.

During mammalian development, early gestational skin wounds heal without a scar. Here we detail a reliable and reproducible model of fetal scarless wound healing in the cutaneous dorsum of E16.5 (scarless) and E18.5 (scarring) mouse embryos.

Early in utero, but not in postnatal life, cutaneous wounds undergo regeneration and heal without formation of a scar. Scarless fetal wound healing occurs ...

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic pressure through echocardiography, as well as to obtain measurements of the Aorta and PA diameter in mice.
Mice older than 10 d of age can be analyzed using the present technique. The technique is composed of 3 main steps: set-up, image acquisition, and image analysis. The set-up step consists of getting the mouse anesthetized with 1% isoflurane, shaving it, and taping it in a supine position to a heated EKG board where the image acquisition will take place. The image acquisition step consists of learning to identify the cardiac structures and obtaining all the required images with its correspondent probe and axis in order to be able to calculate volumes and diameters. The image analysis step consists of measuring the previously acquired images with the aid of computer software.
Advantages of the proposed technique include a fast (15 min) procedure that would allow the researcher to evaluate interventions in a non-invasive, non-terminal approach and therefore follow the same mouse over time; each mouse can be used as its own control. This fact plus having the same operator perform all the acquisition and analysis for the entire experiment minimizes the limitation of operator-dependency. The present methodology is useful for mouse researchers in cardiovascular and pulmonary medicine.

The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary function.

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic ...

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model species such as zebrafish and salamanders that are capable of intrinsic heart regeneration hold promise for future regenerative therapies for human patients. To evaluate the outcome of cardioregenerative experiments it is imperative that heart function can be monitored. The axolotl salamander (A. mexicanum) represents a well-established model species in regenerative biology attaining sizes that allows for evaluation of cardiac function. The purpose of this protocol is to establish methods to reproducibly measure cardiac function in the axolotl using echocardiography. The application of different anesthetics (benzocaine, MS-222, and propofol) is demonstrated, and the acquisition of two-dimensional (2D) echocardiographic data in both anesthetized and unanesthetized axolotls is described. 2D echocardiography of the three-dimensional (3D) heart can suffer from imprecision and subjectivity of measurements, and to alleviate this phenomenon a solid method, namely intra/inter-operator/observer analysis, to measure and minimize this bias is demonstrated. Finally, a method to acquire 3D echocardiographic data of the beating axolotl heart at a very high spatiotemporal resolution and with pronounced blood-to-tissue contrast is described. Overall, this protocol should provide the necessary methods to evaluate cardiac function and model anatomy, and flow dynamics in the axolotl using ultrasound imaging with applications in both regenerative biology and general physiological experiments.

Here we present echocardiography protocols for two-dimensional and three-dimensional image acquisition of the beating heart of the axolotl salamander (Ambystoma mexicanum), a model species in heart regeneration. These methods allow for longitudinal evaluation of cardiac function at a high spatiotemporal resolution.

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model ...