这项工作是支持汉密尔顿 - 费尔利NHMRC奖学金（RH，AL），维多利亚州政府的运营基础设施支援计划（RH，EW）和的玛丽·居里INDUSTRIA学术界的伙伴关系和途径补助，赞助由欧盟委员会（PD ME） 。笔者想感谢博士弗朗西斯安德烈博士Miyague，俄，罗西塔Kinnart女士和伊万先生Laermans的为他们的技术专长，在生产这种视频。

下面的实验动物伦理委员会，天主教鲁汶大学，比利时鲁汶协议批准。我们跟着前面描述的手术过程13，包括一些方法上的变化，尤其是在麻醉过程。 1。诱导胎儿宫内发育迟缓（IUGR） <ol><li>于孕兔（混合登德尔蒙德和新西兰白）的时间被安置在个别网箱12/12小时光照时间表与水和标准兔饲料自由采食 ，从胎龄（GA）18天的访问。 GA 25天（足月约是31天），兔子被转移到手术室手术造成胎儿宫内发育迟缓。手术前，随机分配一个"案例"（胎儿宫内发育迟缓）和"控制"子宫角子宫双角的兔子，用随机软件（GraphPad软件，USA）19。功率计算样本大小应由个别ŗesearchers他们感兴趣的问题。 </li><li> 麻醉过程。 是通过诱导麻醉管理氯胺酮35毫克/公斤（CEVA SANTE ANIMALE，布鲁塞尔，比利时）和甲苯噻嗪5毫克/公斤（CEVA SANTE ANIMALE，布鲁塞尔，比利时）的肌注后腿。然后保持1-4％的 ​​混合吸入麻醉异氟醚（Isoba兽医;雅培制药有限公司Queenborough，肯特，英国O 2的2升/分钟）。将脉搏血氧仪（N-20的Nellcor，Covidien公司，爱尔兰）对产妇的第二个和第三个脚趾连续监测心脏率和动脉氧饱和度。 </li><li> 外科手术。 <ol><li> 术前用药，手术开始之前，管理预防性应用抗生素青霉素G，30万IU（克拉制药，HOOGSTRATEN，比利时），子宫宫缩醋酸甲羟孕酮0.9毫克/千克（德波-孕酮，法玛西亚厄普约翰，Puurs位于比利时）和镇痛丁丙诺啡0.03毫克/公斤（Temgesic先灵葆雅）皮下注射2.5毫升注射器在一个单一的。 </li><li> 兔准备。变暖垫手术的持续时间将兔子。将头发从腹部外科领域应用防腐剂7.5％碘伏（聚维酮碘，普渡大学，康涅狄格州，美国）。一个完整的无菌协议。 </li><li> 腹部剖腹探查术。渗透切口部位皮下局部麻醉（2毫升1％的利多卡因，B布劳恩医疗，比利时）。切口部位应该是在中线的长度约5厘米，在下部2/3的腹部。皮肤一旦被打开，使用尖锐，钝性分离的混合物，至腹直肌鞘暴露。必须小心，以避免血管产妇乳腺位于任一侧的条目（ 图1A）上的中线。抓住腹直肌鞘和腹膜，帐篷，以防止意外的腹腔内容列入，并准确输入使用锐性剥离（ 图1B）。 </li><li> 子宫外置环绕外科领域，用纱布浸泡在温暖的盐水窗帘。小心把握和exteriorize两侧双角子宫。必须小心，不要放置下的每个子宫角阴道或卵巢年底的紧张，因为这可能导致不受欢迎的出血，疼痛和子宫收缩。助理不断灌溉露出温暖的盐水，以防止子宫收缩子宫。触诊和记录胎儿存在于每个喇叭的数量。按照惯例，胎儿卵巢端指定的第一个胎儿。子宫角之一的情况下喇叭，另一种是控制角。胎儿宫内发育迟缓感应识别先前随机分配的情况下，喇叭，然后，更换控制反击号角内部控制胎儿腹部（）。 </li><li> 手术引起的胎儿宫内发育迟缓 。子宫胎盘血管识别每个孕囊在指定的情况下，喇叭（ 图1C）。手术结扎这些船只使用5-0 polyglacin线（薇乔爱惜康，强生医疗，USA）（ 图1D-1E）的40-50％。在实践中，常常有三个维管束提供每个孕囊。在这种情况下，最大的维管束结扎。一旦完成，子宫再次灌溉用温热盐水并小心地返回到腹部。 </li><li> 腹部闭合。关闭腹部两层，采用连续运行2-0 polyglacin线（薇乔爱惜康，强生医疗，美国）。关闭皮肤的polyglactin缝合皮下3-0（薇乔，爱惜，美国强生公司医疗）。喷铝气溶胶在伤口上，以防止兔从购买干扰缝线。 </li><li> 恢复停止麻醉，并密切观察呼吸恢复。兔子，然后收纳如上所述的食物和水随意访问，每天观察。 </li></ol></li></ol> 2。进行胎儿超声心动图和多普勒超声脉冲波<ol><li>同样的兔子，然后转移GA 30天，超声心动图和超声评价。变暖的垫被放置在兔的持续时间的检查。 </li><li> 麻醉过程。 <ol><li>是通过诱导麻醉管理氯胺酮35毫克/公斤（CEVA SANTE ANIMALE，布鲁塞尔，比利时）和甲苯噻嗪5毫克/千克（CEVA SANTE ANIMALE，布鲁塞尔，比利时）的肌注。一旦稳重，取得静脉通道，使用24号外围耳静脉插入套管（BD因西特-W，碧迪输液治疗系统，犹他州，美国）。 </li><li>维持麻醉用氯胺酮和甲苯噻嗪连续输注:2毫升氯胺酮（100毫克/毫升）和1.5毫升甲苯噻嗪（20毫克/毫升），46.5 ml生理盐水，然后通过注射器泵输注在40毫升/小时。三路抽头固定和连接5毫升注射器抢救麻醉2毫升的氯胺酮（100毫克/毫升）和1.5毫升甲苯噻嗪（20毫克/毫升）。很少需要的0.5毫升麻醉救援的丸药。管理镇痛丁丙诺啡0.03毫克/千克（Temgesic先灵葆雅）subcutaneouslyprior手术。应用面罩氧气2升/分钟。将脉搏血氧仪（N-20的Nellcor，Covidien公司，爱尔兰）对产妇的第二个和第三个脚趾连续监测心脏率和动脉氧饱和度。 </li></ol></li><li> 腹部剖腹探查术及子宫表面化。参见1.3.3和1.3.4。 </li><li> 胎儿超声心动图和超声检查定位。 <ol><li>将兔的横向位置朝向研究者。这便于检索一个单一的检查孕囊和子宫胎盘血管防止过度牵拉。尽可能以尽量减少暴露时间，尽量exteriorize只有一个孕囊。确保暴露的孕囊放在纱布灌溉温暖的盐水。中使用的超声检查，以确保在不同的研究组，一般只有在卵巢癌和阴道的每个子宫角的两端胎儿之间的标准化结果的。 </li><li>胎儿心脏功能是很容易受到到子宫外化的效果，改变在胎盘血管从超声波换能器的温度和压力。为了最大限度地减少这些环境和医源性混杂对心脏功能的影响，超声检查必须立即开始表面化后孕囊，应该是系统的，高效的。根据我们的经验，在胎儿心脏功能的变化很少发生在第5分钟的曝光。如果遇到胎儿心动过缓，取出超声探头，重新胎儿，防止胎儿胎盘血管扭结，灌溉用盐水或短暂回暖返回孕囊进入母体腹部。如果胎儿心动过缓是持久性的，检查此FETUS应该放弃赞成检查下胎儿。 </li></ol></li><li> 胎儿超声心动图检查。 <ol><li> VEVO Visualsonics 2100（多伦多，加拿大）的高分辨率microultrasound平台与心脏和应变分析软件的安装是必需的。 MS-250àVisualSonics的换能器（加拿大多伦多VisualSonics）是用于数据采集。这有13-24 MHz的带宽的中心频率为21兆赫。的几何焦点的最大图像宽度是15毫米，23毫米和图像的最大深度为30mm。足迹是28×5.75毫米。按照美国社会的超声心动图的指引和标准采集数据20胎儿超声心动图的性能。 </li><li> 数据采集1的侧视图。在横向视图四腔的电平，记录至少5个心动周期的B模式电影回放，以确定应变，应变率，速度和位移。这是离线分析使用VevoStrain然后，可以（Visualsonics，多伦多，加拿大）算法21 M型超声心动图指标如前所述，在杂志上的细节。这个标准视图中获得。离线测量心脏结构和功能，然后可以分析:内部心室和室间隔直径在收缩和舒张，卷，每搏输出量，短轴缩短率，射血分数和心输出量21 </li><li> 数据采集2:根尖视图。水平的心尖四腔视图中，B模式电影回放可以重复为如上所述的VevoStrain分析。 M型超声心动图是用来评估三尖瓣和二尖瓣环平面收缩漂移（MAPSE）和纵向应变和应变率（TAPSE）22,23心尖视图还允许评估瓣膜血流速度波形和修改后的心肌性能指标如先前描述24 </li></ol></li><li> 胎儿胎盘脉冲多普勒ULT挥手rasound。 </li></ol>流速波形（FVW）是通过脐部血管彩色多普勒定位，然后将脉冲多普勒取样门上免费循环脐带脐动脉25脐动脉，大脑中动脉（MCA）FVW位于Willis环是由位于彩色多普勒后，将脉冲多普勒取样门刚刚超越马华的起源。26静脉导管（DV）是通过将脉冲多普勒取样门近端部分的DV看到FVW彩色多普勒，它起源从肝内脐静脉在矢状或横向视图的胎儿。26搏动指数（PI），离线计算的的心血管VisualSonics分析软件。

笔者扬德虎格教授有一个研究协议，VisualSonics的。的其余没有披露。

我们已经使用了一个验证的方法，手术子宫胎盘血流量减少，产生胎儿宫内发育迟缓13-16兔子，后来检查胎儿心脏功能14描述microultrasound的技术和可用在VEVO VisualSonics 2100心脏功能分析。繁殖能力，人类胎儿宫内发育迟缓胎儿胎儿胎盘多普勒变化中的小动物模型，然后让最近描述的超声心动图检查心脏功能是胎儿心脏研究可能取得进展，在临床相关的方式。 小动物模型通常依靠产妇热量限制或低蛋白质消耗，但这些限制无法证明减少胎盘血流量，在发达国家，胎儿宫内发育迟缓的主要机制。27此外，手术双侧子宫动脉结扎大鼠，而常见的，不重复导致我Ñ ​​增长限制28兔胎儿在当前的方法，我们表明胎盘功能不全，脐动脉多普勒（UA AREDF），在人类胎儿宫内发育迟缓的超声所见一致一个缺席或逆转的舒张末期流是显而易见的。实验已经证明，这个多普勒信号的电阻增加，反 ​​映下游阻抗血流在胎盘血管床，是胎盘功能不全的指标。29存在明显的UA AREDF的50 - 70％的绒毛血管功能失调时30,31临床UA AREDF是一个强大的预测缺氧和围产儿预后较差，且有1级证据，以支持其使用在高危妊娠的管理。 在这种模式下，如果UA AREDF的观察，研究者可以确信的主要手术是成功的，产生严重的胎盘功能不全，进一步的超声心动图IC评估是可能是富有成效的。胎儿超声心动图最近主要诊断领域的先天性畸形一发不可收拾，到现在心脏功能提供详细的功能性评估。18多普勒和M-模式可以用来评估胎儿心功能，并推导出心输出量的措施。32最近，如散斑跟踪和应变的测量33，已经描述了在胎儿心脏功能的新颖的指数，其中心肌性能指标24,34:组织多普勒35和三维（3D）的技术。32目前的研究的一个重要特征是这些最新进展，也可以使用Visualsonics VEVO 2100 microultrasound的心脏功能分析软件这个小规模的兔模型。此外，如前面所述14，这种模式也允许评估其他血管territ中胎儿的血流动力学反应文论，尤其是大脑中动脉，静脉导管及主动脉峡部，在临床实践中被广泛用于检查胎儿生长受限时36同样，给予糖皮质激素在早产准备的影响可能也被审查。37， 38这个的兔模型提供进一步在内部控制方面的优势，相反角子宫，的类似绒毛和胎盘hemochorial人类妊娠13，成本低，可用性和比较容易处理。 尽管如此，有几个这种模型的局限性，必须加以解决。的主要限制是在超声心动图的医源性胎儿心动过缓。母系给药吸入异氟醚，可导致胎儿心动过缓39，并应保持在最低限度，或在我们的例子中不使用期间，超声心动图。相反，我们取代静脉滴注氯胺酮甲苯噻嗪，最近已表明不改变兔平均动脉压40，从而推测保持胎盘（因此胎儿）灌注。尽管这一做法，暴露孕囊的外部环境，处理和超声换能器的压力都可以暂时导致胎儿心动过缓。我们描述的方法方式，以尽量减少这种影响，但对于精确的结果，我们认为是最好的限制胎儿胎盘超声心动图和多普勒超声波占总摄入量的5分钟左右。随着日益复杂的超声心动图技术和学习曲线，现在临床文献41，事先需要精心策划，以确保标准化的结果。超声心动图测量的几个在这项研究中，例如瓣膜环形平面收缩漂移和斑点追踪应变分析，没有建立在当前产科临床实践中，尽管日EIR使用成人心脏病。42,43然而，鉴于最近的研究兴趣，这些新颖的测量胎儿医学，我们选择了将它们包括在我们的方法，研究人员告知，他们是可行的，使用这个兔子模型得到。这些具体的参数分析，胎儿宫内发育迟缓胎儿这种方法论的研究范围之外。另一种限制涉及到的自然倾向在兔胎儿宫内发育迟缓的基础上，因此建议灌注卵巢和阴道每个喇叭的两端分配胎儿情况胎位44。此外，本方法中，胎龄25天用于手术诱导胎儿宫内发育迟缓。这是基于先前描述的实验成功，但是预期的死亡率是50％。13,14最后，胎儿的大小排除慢性仪表购买非实施安乐死测量血流动力学流探针的位置在绵羊模型是非常有用的，并重复版采血11总之，子宫胎盘血管选择性结扎兔子与的后续microultrasound检查心脏功能产生胎儿宫内发育迟缓的动物模型与现代临床实践是一致的，因此有用的双向平移研究员。

心血管疾病负担，导致胎儿宫内发育迟缓（IUGR）不能被夸大。它是导致死胎，先天性畸形后1胎儿宫内发育迟缓是指对胎儿未能达到其增长潜力，通常是一个导致胎盘功能不全。2在幸存者中，心肌功能障碍明显的心血管健康状况不佳是显而易见的整个生命跨度在婴儿期和童年3,4和后续的高血压，糖尿病6，肥胖在成年生活中发展-从出生的所有累积的心脏危险因素对缺血性心脏疾病过早死亡7 发展动物模型的特点，建立胎儿宫内发育迟缓和胎儿的后续反应减少基板的可用性母胎通信是必要的，如果我们双方更好地了解胎儿宫内发育迟缓有关汽车的病理生理DIAC减值和心脏保护策略，以提高胎儿和出生后的健康发展。在这方面，许多不同的模式，不同的植物物种已被描述。8胎儿宫内发育迟缓通常产妇营养不足引起低蛋白饮食在啮齿类动物中，9手术切除或结扎子宫血流量在啮齿类动物和豚鼠10或闭塞脐动脉的羊。11然而，很明显，没有模型充分概括了人类胎儿宫内发育迟缓。 在当前的方法论研究，我们采用了很好的验证方法选择性子宫胎盘血管中断，不仅产生超声观察胎儿的心血管反应，临床上14，但也允许审讯胎儿心脏功能新颖的超声心动图使用microultrasound技术在兔13-16的VEVO VisualSonics 2100。虽然多普勒超声fetopl保持acental血管的基石，目前的产前监测胎儿宫内发育迟缓胎儿17，超声心动图功能正在越来越多地被用于疾病的病理生理机制提供新的见解，并以评估胎儿健康18因此，在这里我们采取这些进步从临床研究和描述的动物模型，港口不仅成像的复杂性，但也提供了实验平台调查机制的途径和新的疗法。

<table border="1">
	<tbody>
 <tr>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalog Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>Ketamine</td>
 <td>Ceva Sante Animale</td>
 <td></td>
 <td><a href="http://www.ceva.com/en" target="_blank">http://www.ceva.com/en</a></td>
 </tr>
 <tr>
 <td>Xylazine</td>
 <td>Ceva Sante Animale</td>
 <td></td>
 <td><a href="http://www.ceva.com/en" target="_blank">http://www.ceva.com/en</a></td>
 </tr>
 <tr>
 <td>Depot Provera</td>
 <td>Pharmacia Upjohn</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Penicillin G</td>
 <td>Kela Pharma</td>
 <td></td>
 <td><a href="http://www.kela.be" target="_blank">http://www.kela.be</a></td>
 </tr>
 <tr>
 <td >Lidocaine</td>
 <td>B Braun Medical</td>
 <td></td>
 <td><a href="http://www.bbraun.com/" target="_blank">http://www.bbraun.com/</a></td>
 </tr>
 <tr>
 <td>Temgesic</td>
 <td>Schering-Plough</td>
 <td></td>
 <td><a href="http://www.merck-animal-health-usa.com/" target="_blank">http://www.merck-animal-health-usa.com/</a></td>
 </tr>
 <tr>
 <td>Isolurane</td>
 <td>Isoba Vet; Abbott Laboratories Ltd</td>
 <td></td>
 <td><a href="http://www.abbottanimalhealth.com/index.html" target="_blank">http://www.abbottanimalhealth.com/index.html</a></td>
 </tr>
 <tr>
 <td>Ethicon</td>
 <td>Johnson and Johnson</td>
 <td></td>
 <td><a href="http://www.ethiconproducts.co.uk/products/sutures" target="_blank">http://www.ethiconproducts.co.uk/products/sutures</a></td>
 </tr>
 <tr>
 <td>Ethicon</td>
 <td>Johnson and Johnson</td>
 <td></td>
 <td><a href="http://www.ethiconproducts.co.uk/products/sutures" target="_blank">http://www.ethiconproducts.co.uk/products/sutures</a></td>
 </tr>
 <tr>
 <td>Ethicon</td>
 <td>Johnson and Johnson</td>
 <td></td>
 <td><a href="http://www.ethiconproducts.co.uk/products/sutures" target="_blank">http://www.ethiconproducts.co.uk/products/sutures</a></td>
 </tr>
 <tr>
 <td>VEVO 2100</td>
 <td>VisualSonics</td>
 <td>SN100-0032</td>
 <td><a href="http://www.visualsonics.com/" target="_blank">http://www.visualsonics.com/</a></td>
 </tr>
 <tr>
 <td>Aquasonic Gel</td>
 <td>Parker Laboratories</td>
 <td>01 02</td>
 <td><a href="http://www.parkerlabs.com/ultrasound_products.html" target="_blank">http://www.parkerlabs.com/ultrasound_products.html</a></td>
 </tr>
 <tr>
 <td>Nellcor N-20PA Pulse oximeter</td>
 <td>Covidien</td>
 <td></td>
 <td><a href="http://www.nellcor.com/prod/PRODUCT.ASPX?S1=POX&amp;S2=MON&amp;id=282&amp;V" target="_blank">http://www.nellcor.com/prod/PRODUCT.ASPX?S1=POX&amp;S2=MON&amp;id=282&amp;V</a></td>
 </tr>
	 </tbody>
 </table>

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

胎儿宫内发育迟缓（IUGR）导致心功能异常，这是明显的产前由于胎儿胎盘多普勒超声及胎儿超声心动图的进步。越来越多，这些成像方式被雇用临床检查心脏功能，并在子宫内健康评估，从而指导出生决策时机。在这里，我们使用的胎儿宫内发育迟缓，让兔子模型分析心脏功能的临床相关的方式。使用异氟醚诱导麻醉，胎儿宫内发育迟缓手术创造胎龄25天进行剖腹探查，露出双角子宫，然后结扎每个孕囊在一个单一的子宫角子宫胎盘血管供应的40-50％。在兔双角子宫的其他角作为内部控制胎儿。然后，在胎龄30天（足月）恢复后，同一只兔子进行检查胎儿心脏功能。麻醉诱导与吉胆INE和甲苯噻嗪肌肉注射，然后保持连续静脉滴注氯胺酮和甲苯噻嗪对胎儿的心脏功能，以尽量减少医源性影响。重复剖腹探查进行揭露每个孕囊及胎儿心脏功能的一个microultrasound考试（VEVO VisualSonics 2100）进行。胎盘功能不全是由凸起的搏动指数或缺席或逆转的舒张末期脐动脉多普勒波形流可见一斑。静脉导管和大脑中动脉多普勒检查。胎儿超声心动图检查进行记录B模式，M模式和流速波形在横向和心尖意见。离线计算确定标准的M型心脏变量，三尖瓣和二尖瓣环平面收缩漂移，斑点追踪应变分析，修改后的心肌性能指数和血管血流速度波形的利益。这个小动物模型，胎儿宫内发育迟缓，因此能提供在电脑上检查Ø心脏功能与目前的临床实践是一致的，因此可用于转化研究设置。

一个不对称的生长受限制的子宫胎盘血管结扎的胎儿和胎盘从较正常对照图1F中的胎儿和胎盘。不对称增长证实了减少新生儿出生体重和头围增大:腹围比对照组。从胎儿胎盘多普勒研究的代表性结果示于图2。正端控制胎儿舒张期血流显示一个正常的低电阻模式。随着逐步增加阻力见于胎盘在胎儿宫内发育迟缓的胎儿，没有，然后逆转舒张末流是显而易见的。 图3显示正常高电阻大脑中动脉多普勒信号在一个健康的胎儿和积极的浪潮在同一胎儿静脉导管。在胎儿宫内发育迟缓，增加静脉导管及转回的波搏动指数可以看出，14个代表性的成果<html>从M-模式胎儿超声心动图，然后如图4所示。这种横向视图允许内部心室直径和体积的计算。心尖视图允许计算的TAPSE及MAPSE。 图5显示了斑点追踪速度矢量以及由此产生的区域应变曲线计算应变，应变率，位移和速度。 <img alt="图1" src="/files/ftp_upload/50392/50392fig1.jpg" /> 图1。答:中线剖腹探查暴露腹直肌鞘，箭头= mammory腺体，B:安全进入腹腔，C:箭头=子宫胎盘血管供应孕囊，D:缝合方法; E:箭头外科技术的兔子模型中创建胎儿宫内发育迟缓。 =完成子宫胎盘血管结扎，F:代表控制和胎儿宫内发育迟缓胎儿和胎盘。 RE 2"SRC ="/ files/ftp_upload/50392/50392fig2.jpg"/&gt; 图2。多普勒超声脐动脉。:积极舒张末期流速（EDF），B:缺席舒张末期流（AEDF），C:逆转舒张末期流速（REDF）。 <img alt="图3" src="/files/ftp_upload/50392/50392fig3.jpg" /> 图3:多普勒超声静脉导管 S = S波（心室收缩收缩），D = D波（心室舒张早期），=一个波（心房收缩），B:大脑中动脉多普勒超声 。 <img alt="图4" src="/files/ftp_upload/50392/50392fig4.jpg" /> 图4。 M模式心动。答:横向四腔心切 ，LVID =左室内径，IVSD =脑室间隔的直径，RVID =右VEESD间隔直径ntricular，=收缩末期内径，EDD =舒张末期内径; B:心尖显示三尖瓣环平面收缩漂移（TAPSE），C:心尖视图显示二尖瓣环平面收缩漂移（MAPSE）。 <img alt="图5" src="/files/ftp_upload/50392/50392fig5.jpg" /> 图5。胎儿心脏应变分析。:地区内和外延鸟蛤属的左心室定义的利息，B:6个心肌节段 ，SR =收缩期峰值应变率，C:6个心肌节段的应变曲线 ，STR的应变率曲线 =收缩期峰值株。心脏运动描绘M模式展示舒张末期（ED）和收缩末期（ES） <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50392/50392fig5large.jpg" target="_blank">点击此处查看大图</a> 。

Watch this Scientific Journal Video about Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction at JoVE.com

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

我们描述检查胎儿心脏功能与现代功能的胎儿超声心动图和使用VisualSonics VEVO 2100 microultrasound的胎儿胎盘多普勒超声在手术引起的胎儿宫内生长受限模型兔子。

在家兔模型宫内生长受限胎儿超声心动图和多普勒超声脉冲波

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

fetal-echocardiography-pulsed-wave-doppler-ultrasound-rabbit-model

Nanyang Technological University

Research

JoVE Journal

Medicine

28.1K 次观看.  University Hospitals Leuven. 我们描述检查胎儿心脏功能与现代功能的胎儿超声心动图和使用VisualSonics VEVO 2100 microultrasound的胎儿胎盘多普勒超声在手术引起的胎儿宫内生长受限模型兔子。

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

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.

经胸超声心动图在小鼠

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

科研

医学

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.

小鼠超声心动图和超声成像

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.

在斑马鱼模型的胎儿酒精暴露评估致畸的变化

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

A Novel Surgical Approach for Intratracheal Administration of Bioactive Agents in a Fetal Mouse Model

Prenatal pulmonary delivery of cells, genes or pharmacologic agents could provide the basis for new therapeutic strategies for a variety of genetic and acquired diseases. Apart from congenital or inherited abnormalities with the requirement for long-term expression of the delivered gene, several non-inherited perinatal conditions, where short-term gene expression or pharmacological intervention is sufficient to achieve therapeutic effects, are considered as potential future indications for this kind of approach. Candidate diseases for the application of short-term prenatal therapy could be the transient neonatal deficiency of surfactant protein B causing neonatal respiratory distress syndrome1,2 or hyperoxic injuries of the neonatal lung3. Candidate diseases for permanent therapeutic correction are Cystic Fibrosis (CF)4, genetic variants of surfactant deficiencies5 and &alpha;1-antitrypsin deficiency6.
Generally, an important advantage of prenatal gene therapy is the ability to start therapeutic intervention early in development, at or even prior to clinical manifestations in the patient, thus preventing irreparable damage to the individual. In addition, fetal organs have an increased cell proliferation rate as compared to adult organs, which could allow a more efficient gene or stem cell transfer into the fetus. Furthermore, in utero gene delivery is performed when the individual's immune system is not completely mature. Therefore, transplantation of heterologous cells or supplementation of a non-functional or absent protein with a correct version should not cause immune sensitization to the cell, vector or transgene product, which has recently been proven to be the case with both cellular and genetic therapies7.
In the present study, we investigated the potential to directly target the fetal trachea in a mouse model. This procedure is in use in larger animal models such as rabbits and sheep8, and even in a clinical setting9, but has to date not been performed before in a mouse model. When studying the potential of fetal gene therapy for genetic diseases such as CF, the mouse model is very useful as a first proof-of-concept because of the wide availability of different transgenic mouse strains, the well documented embryogenesis and fetal development, less stringent ethical regulations, short gestation and the large litter size.
Different access routes have been described to target the fetal rodent lung, including intra-amniotic injection10-12, (ultrasound-guided) intrapulmonary injection13,14 and intravenous administration into the yolk sac vessels15,16 or umbilical vein17. Our novel surgical procedure enables researchers to inject the agent of choice directly into the fetal mouse trachea which allows for a more efficient delivery to the airways than existing techniques18.

We developed a novel surgical approach for intratracheal administration of bioactive agents into the mouse fetus. The delivery route is more efficient in targeting the fetal mouse lungs than the commonly used intra-amniotic injection. This procedure has to date not been described in a mouse model.

一种新的手术方法气管内注射生物活性剂在胎鼠模型

Prenatal pulmonary delivery of cells, genes or pharmacologic agents could provide the basis for new therapeutic strategies for a variety of genetic and ...

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.

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.

小鼠胎儿超声心动图

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

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.

对无瘢痕修复鼠标胎儿皮肤模型

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

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. Despite the discovery of key regulators of uterine contractility, this process is still not fully understood. Transgenic mice provide an ideal model in which to study parturition. Previously, the only method to study uterine contractility in the mouse was ex vivo isometric tension recordings, which are suboptimal for several reasons. The uterus must be removed from its physiological environment, a limited time course of investigation is possible, and the mice must be sacrificed. The recent development of radiometric telemetry has allowed for longitudinal, real-time measurements of in vivo intrauterine pressure in mice. Here, the implantation of an intrauterine telemeter to measure pressure changes in the mouse uterus from mid-pregnancy until delivery is described. By comparing differences in pressures between wild type and transgenic mice, the physiological impact of a gene of interest can be elucidated. This technique should expedite the development of therapeutics used to treat myometrial disorders during pregnancy, including preterm labor.

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

This manuscript provides a protocol for implanting telemeters in the mouse for the purpose of measuring intrauterine pressures during pregnancy.

宫内遥测来衡量鼠标收缩压力<em&gt;在体内</em

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. ...

Percutaneous Contrast Echocardiography-guided Intramyocardial Injection and Cell Delivery in a Large Preclinical Model

Cell and gene therapy are exciting and promising strategies for the purpose of cardiac regeneration in the setting of heart failure with reduced ejection fraction (HFrEF). Before they can be considered for use, and implemented in humans, extensive preclinical studies are required in large animal models to evaluate the safety, efficacy, and fate of the injectate (e.g., stem cells) once delivered into the myocardium. Small rodent models offer advantages (e.g., cost effectiveness, amenability for genetic manipulation); however, given inherent limitations of these models, the findings in these rarely translate into the clinic. Conversely, large animal models such as rabbits, have advantages (e.g., similar cardiac electrophysiology compared to humans and other large animals), whilst retaining a good cost-effective balance. Here, we demonstrate how to perform a percutaneous contrast echocardiography-guided intramyocardial injection (IMI) technique, which is minimally invasive, safe, well tolerated, and very effective in the targeted delivery of injectates, including cells, into several locations within the myocardium of a rabbit model. For the implementation of this technique, we also have taken advantage of a widely available clinical echocardiography system. After putting in practice the protocol described here, a researcher with basic ultrasound knowledge will become competent in the performance of this versatile and minimally invasive technique for routine use in experiments, aimed at hypothesis testing of the capabilities of cardiac regenerative therapeutics in the rabbit model. Once competency is achieved, the whole procedure can be performed within 25 min after anaesthetizing the rabbit.

Novel therapeutic strategies in cardiac regenerative medicine require extensive and detailed studies in large preclinical animal models before they can be considered for use in humans. Here, we demonstrate a percutaneous contrast echocardiography-guided intramyocardial injection technique in rabbits, which is valuable for hypothesis testing the efficacy of such novel therapies.

经皮超声心动图引导心肌注射液与大鼠前体细胞的临床研究

Cell and gene therapy are exciting and promising strategies for the purpose of cardiac regeneration in the setting of heart failure with reduced ejection ...

Model Surgical Training: Skills Acquisition in Fetoscopic Laser Photocoagulation of Monochorionic Diamniotic Twin Placenta Using Realistic Simulators

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome (TTTS), but is technically challenging and can lead to significant complications. Acquiring and maintaining the necessary surgical skills require consistent practice, a critical caseload, and time. Training on realistic surgical simulators can potentially shorten this steep learning curve and enables several proceduralists to acquire procedure-specific skills simultaneously. Here we describe realistic simulators designed to allow the user familiarity with the equipment and specific steps required in the surgical treatment of TTTS, including fetoscopic handling, approaches to anterior and posterior placenta, recognition of anastomoses, and efficient coagulation of vessels. We describe the skills that are especially important in conducting placental laser coagulation that the surgeon can practice on the model and apply in a clinical case. These models can be adapted easily depending on the availability of materials and require standard fetoscopy equipment. Such training systems are complementary to traditional surgical apprenticeships and can be useful aids for fetal medicine units that provide this clinical service.

Practicing the specific skills required for fetoscopic laser coagulation of monochorionic placental anastomoses on realistic models can aid less experienced surgeons in overcoming the steep learning curve associated with this procedure that is now regarded as the standard of care for twin-twin transfusion syndrome.

模型外科训练: 用逼真模拟器 Fetoscopic 激光光凝单绒毛膜 Diamniotic 双胎胎盘的技能习得

Fetoscopic laser coagulation of arterio-venous anastomoses (AVA) in a monochorionic placenta is the standard of care for twin-twin transfusion syndrome ...

A Pleural Effusion Model in Rats by Intratracheal Instillation of Polyacrylate/Nanosilica

Pleural effusion is a prevalent clinical finding of many pulmonary diseases. Having a useful animal pleural effusion model is very important to study these pulmonary diseases. Previous pleural effusion models paid more attention to biological factors rather than nanoparticles in the environment. Here, we introduce a model to make pleural effusion in rats by intratracheal instillation of polyacrylate/nanosilica, and a method of nanoparticle isolation in the pleural effusion. By intratracheal instillation of polyacrylate/nanosilica with concentrations of 3.125, 6.25 and 12.5 mg/kg&#8729;mL, the pleural effusion in rats presented on day 3, peaked at days 7-10 in 6.25 and 12.5 mg/kg&#8729;mL groups, then slowly decreased and disappeared on day 14. When the concentration of polyacrylate/nanosilica increased, the pleural effusion is produced more and faster. This pleural fluid was detected by ultrasound examination or CT chest scanning and confirmed by dissection of rats. Silica nanoparticles were observed in the rats' pleural effusion by transmission electron microscope. These results showed that the exposure to polyacrylate/nanosilica leads to the induction of pleural effusion, which was consistent with our previous report in humans. Additionally, this model is beneficial for the further study of nanotoxicology and the pleural effusion diseases.

Here, we present a protocol to construct a pleural effusion model in rats by intratracheal instillation of polyacrylate/nanosilica.

聚丙烯酸/纳米水的气管内灌注积液模型

Pleural effusion is a prevalent clinical finding of many pulmonary diseases. Having a useful animal pleural effusion model is very important to study ...