GHK es apoyado por el NIH / NHLBI K08-HL098565 y el Instituto de Investigación Cardiovascular de la Universidad de Chicago. Todos los métodos experimentales descritos son aprobados por el Cuidado de Animales institucional y el empleo Comisión de la Universidad de Chicago.

<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>

No hay conflictos de interés declarado.

La capacidad de realizar mediciones en serie y para detectar los fetos mutantes con defectos cardíacos pone de manifiesto la utilidad de la ecocardiografía para investigar el desarrollo cardiovascular normal y anormal. Análisis de la estructura y la función cardíaca in vivo se ha convertido en una parte integral en la descripción de las modificaciones genéticas y no genéticas para el desarrollo normal del feto. La disponibilidad de 2D guiada por Doppler hace que sea posible controlar la frecuencia cardi...

<table border="1"><tbody><tr><td> Vevo 770 Imaging System </td><td> VisualSonics </td><td></td><td> (Toronto, Canadá) </td></tr><tr><td> RMV707B.15-45 MHz transductor </td><td></td><td></td><td></td></tr><tr><td> Tec 3 vaporizador isoflurano </td><td></td><td></td><td></td></tr><tr><td> Isoflurano (2-cloro-2-(difluorometoxi) -1,1,1-trifluoro-etano) </td><td></td><td></td><td></td></tr></tbody></table>

murine fetal echocardiography

Los ratones transgénicos que muestran anormalidades en el desarrollo y la función cardíaca representan una herramienta poderosa para la comprensión de los mecanismos moleculares que subyacen a la función cardiovascular normal y la base fisiopatológica de la enfermedad cardiovascular humano. La muerte fetal y perinatal es una característica común en el estudio de las alteraciones genéticas que afectan el desarrollo cardíaco 1-3. Con el fin de estudiar el papel de las alteraciones genéticas o farmacológicas en el desarrollo inicial de la función cardiaca, la ecografía del feto vivo se ha convertido en una herramienta importante para la detección temprana de anomalías y longitudinal de seguimiento. Imágenes por ultrasonido no invasiva es un método ideal para la detección y el estudio de las malformaciones congénitas y el impacto en la función cardiaca antes de la muerte 4. Se permite el reconocimiento precoz de anormalidades en el feto de vida y de la progresión de la enfermedad puede ser seguida en el útero con estudios longitudinales 5,6.Hasta hace poco, la imagen del corazón de ratón fetal frecuentemente involucrados métodos invasivos. El feto tenía que ser sacrificado para realizar microscopía de resonancia magnética y microscopía electrónica o quirúrgicamente entregado por microscopía transiluminación. Una aplicación de sondas de alta frecuencia convencional con 2-D y pulsos de onda Doppler se ha demostrado para proporcionar mediciones de la contracción cardíaca y la frecuencia cardiaca durante el desarrollo embrionario con bases de datos de los cambios normales de desarrollo disponibles actualmente 6-10. Modo M proporciona además importantes datos funcionales, aunque, los planos de imagen adecuados son a menudo difíciles de obtener. Alta frecuencia de imágenes por ultrasonido del feto ha mejorado la resolución 2-D y puede proporcionar información relevante sobre el desarrollo temprano de las estructuras cardiacas 11.

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

Murine Fetal Echocardiography

La muerte fetal y perinatal es una característica común en el estudio de las alteraciones genéticas que afectan el desarrollo cardíaco. Alta frecuencia de imágenes por ultrasonido ha mejorado en 2-D y resolución pueden proporcionar información relevante sobre el desarrollo cardíaco temprano y es un método ideal para detectar el impacto en la estructura y función cardíaca antes de la muerte.

La ecocardiografía fetal murino

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

Research

JoVE Journal

Medicine

17.1K vistas.  University of Chicago. La muerte fetal y perinatal es una característica común en el estudio de las alteraciones genéticas que afectan el desarrollo cardíaco. Alta frecuencia de imágenes por ultrasonido ha mejorado en 2-D y resolución pueden proporcionar información relevante sobre el desarrollo cardíaco temprano y es un método ideal para detectar el impacto en la estructura y función cardíaca antes de la muerte.

Video: Murine Fetal Echocardiography

Transthoracic Echocardiography in Mice

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.

Ecocardiografía transtorácica en ratones

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

Investigación

Medicina

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

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 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 heart.

Alta frecuencia de alta resolución Ecocardiografía: Primera evidencia sobre la no-invasivo medida repetida de la tensión de miocardio, la contractilidad y la insuficiencia mitral en el corazón por isquemia-reperfusión murino

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

Murine Echocardiography and Ultrasound Imaging

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.

Ecocardiografía murino y la ecografía

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.

Evaluación de los cambios teratogénicos en un modelo de pez cebra de la exposición fetal al alcohol

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

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

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.

Ecocardiografía Fetal y Ecografía Doppler de onda pulsada en un modelo de conejo de Restricción del crecimiento intrauterino

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.

El aislamiento, la cultura, y de imágenes de Human Fetal pancreáticas grupos de células

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.

En el útero de medición de la frecuencia cardíaca en el ratón por no invasiva Ecocardiografía en modo M

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.

Un ratón fetal Modelo de la piel de la reparación de heridas sin cicatrices

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

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

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.

Murino de Ecocardiografía del atrio izquierdo, la aorta y arteria pulmonar

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

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

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.

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 resolution.

Ecocardiografía 2D y 3D en el ajolote (Ambystoma Mexicanum)

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 ...