我们要感谢马克. 史密斯在射线成像方面的帮助。这项工作得到了 nih T32 赠款的支持, 为心血管疾病 (蟒蛇) 的跨学科研究, 美国心脏协会 (SMC) 和 nih R35 补助金 (拿 dk)。

《动物处理议定书》由马里兰州马里兰大学机构动物护理和使用委员会 (0116024 号动物议定书) 批准, 并按照 AAALAC 国际标准进行。
1. 试剂的制备
<ol><li>
肝 素
	<ol>
<li>稀释250µL 的 1000年 U/毫升肝素硫酸酯50毫升的磷酸盐缓冲盐水, 使最终浓度的 5 U/毫升。</li>
		<li>温暖的血气 (5 U/毫升) 磷酸盐缓冲盐水, 这将取代血液在血管中的水浴设置为37°c。</li>
		<li>通过连接所需油管和2个空10毫升注射器, 1 血气盐缓冲液和1用于造影剂, 准备压力控制泵。</li>
		<li>用温暖的血气磷酸盐填充油管, 从压力泵的油管中取出气泡。</li>
	</ol>
</li>
	<li>
对比剂 注: 请参阅对比剂套件成分的材料表。<ol>
<li>将色素化合物与稀释剂混合, 以达到1:6 染料稀释率。</li>
		<li>在使用前 (步骤 2.3.12), 添加200µL 的固化剂, 每5毫升整除稀释色素化合物和混合他们好 (4% 按体积)。 注: 制造商报告工作时间为40分钟。当硅橡胶造影剂在添加固化剂后开始聚合20分钟后, 在输液前立即准备溶液是很重要的。</li>
	</ol>
</li>
	<li>
BAPN 饮用水
	<ol>
<li>在饮用水中溶解β-aminopropionitrile (BAPN), 以创建最终浓度为3克/升 (根据文献中先前描述的协议改编)9,16,17。</li>
		<li>将含 BAPN 的饮用水管理到一组小鼠, 一旦它们4周的年龄, 直到微 CT 灌注的时间。</li>
	</ol>
</li>
</ol>2. 手术方法
<ol><li>
动物制剂
	<ol>
<li>在3周的时间里, 将老鼠戒掉, 维持在12小时 light/12 的黑循环, 并喂养他们标准的啮齿动物周。对于 BAPN 治疗组, 管理新鲜准备 BAPN 饮用水 16-26 周广告随意。为控制动物提供标准的饮用水广告随意。</li>
	</ol>
</li>
	<li>
麻醉技术 注:24 h 在 CT 分析前, 执行以下步骤。手术程序的制定, 以准备标本的死后心脏灌注。<ol>
<li>通过一个精确的蒸发器提供 100% O2和3% 异氟醚的感应罐进行麻醉。麻醉诱导后, 停止异氟醚, 并冲洗室与 O2。用 2-2.5% 异氟醚和1升/分2通过鼻锥维持麻醉。</li>
		<li>将感应室和面罩连接到木炭清除剂中, 用于废气吸附保护人员。通过证明没有对有害刺激 (脚趾捏) 的反应, 确保足够的麻醉飞机。</li>
		<li>准备一个由手术托盘和必要的手术器械组成的手术场。</li>
		<li>将动物转移到手术领域, 并将其定位在背卧床。</li>
	</ol>
</li>
	<li>
手术技术
	<ol>
<li>使用剪刀, 使中线切口通过皮肤和软组织从中间的耻骨联合到胸骨切口, 延伸通过皮肤和软组织覆盖胸骨。</li>
		<li>使用剪刀, 在剑突过程中的隔膜上创建一个孔进入胸腔。</li>
		<li>用剪刀解剖腹侧胸壁的隔膜, 双边。</li>
		<li>穿过肋软骨, 将肋骨从胸骨的右胸骨边界分开。</li>
		<li>在胸骨尖端 (靠近剑突的过程) 应用一个细止血钳, 移动止血 cranially, 使其定位在鼠标头上。这将收回胸腺和胸骨远离心脏, 暴露心脏和伟大的血管进一步操纵。</li>
		<li>尖锐地解剖心脏和胸壁之间的任何附着物。</li>
		<li>将27口径 IV 导管针连接至注射器预装10毫升的血气磷酸盐缓冲盐水 (5 U/毫升), 并填写所有油管与缓冲, 以消除空气气泡从管的压力泵。</li>
		<li>当液体线上的气泡在准备液体时使用小心可能会阻碍较小容器的填充。限制在动物准备过程中损坏的船只数量, 因为这会导致造影剂泄漏出被切断的容器, 改变完整填充所需的体积, 并将工件引入最终成像。</li>
		<li>用直角钳固定的27口径针刺穿左心室。立即切开右心室或下腔静脉, 排出肝素溶液和血液。 注: 肝素可作为抗凝剂, 防止动物死后血管凝固。</li>
		<li>用单个注射器泵灌注动物以2毫升/分钟的恒定速率。注意器官的可见烫漂。继续灌注, 直到灌流液从静脉循环排出的血液没有血 (约 5-6 毫升)。停止泵。</li>
		<li>从10毫升注射器中拔下静脉注射导管, 注意不要干扰针在左心室的位置。</li>
		<li>在完全放血后立即将造影剂溶液分离成5毫升整除数, 并在此时添加固化剂 (见步骤 1.2)。把它们搅拌好。将5毫升的造影剂混合成一个10毫升的注射器, 并用它灌注动物。</li>
		<li>对于完整的血管充填 (动脉和静脉), 继续输液通过点, 当它可以看到退出静脉解决方案。寻找成功灌注的迹象, 包括在冠状动脉、肺动脉、肠道和肝脏血管中的铸造剂的可视化。</li>
		<li>造影剂在室温下大约20分钟后会痊愈。固化后, 根据需要, 收获各器官, 并将其固定在10% 中性缓冲福尔马林中。如果样品不用于第二天的显微 CT 扫描, 则修复整个尸体。如果尸体将在随后的一天使用, 把他们放置在一个金属托盘, 并把他们放在冰箱4摄氏度, 以治愈过夜。</li>
	</ol>
</li>
</ol>3. 显微 CT 扫描及参数
注意: 特定的图像采集参数将取决于使用的机器。
<ol><li>获取每只老鼠的 x 射线计算机断层扫描图像在使用微 CT 扫描器进行灌注后的第二天, 使用 X 射线管电压为 55 kVp, 电流为150μA, 系统放大系数为 2.19, CCD 相机像素 binning 因子2。这将生成一个有效的像素大小为29µm。<ol>
<li>将小鼠胴体仰卧在微 CT 扫描台上, 获得侦察 X 线扫描。</li>
		<li>在躯干上聚焦57.4 毫米 (轴向) x 37.1 毫米 (transaxial) 的探测器视野, 以图像的主动脉全长。</li>
		<li>获取180个图像投影, 其旋转增量为2度, 每次投影的时间为2800毫秒。</li>
	</ol>
</li>
	<li>用改进的 Feldkamp 算法重建图像;重建的体素大小是 29 x 29 x 29 µm3 (切片厚度 = 29 µm) 使用的多模式3D 可视化插件的软件在这里使用。</li>
</ol>4. 后处理和渲染
<ol><li>使用适当的软件将 CT 数据转换为 DICOM 格式。</li>
	<li>分析图像以确定是否存在动脉瘤。测量主动脉弓、降胸主动脉和腹主动脉最宽点的小轴直径 (如前所述18 ) (图 1)。 注意: 在我们的研究中, 图像被两个独立的观察者 (一个盲人) 分析, 利用 DICOM 查看器来确定动脉瘤是否存在。在主动脉弓、降胸主动脉和腹主动脉的最宽点测量了小轴直径, 如前所述19 (图 1)。BAPN 未治疗小鼠的平均非动脉瘤性动脉段建立正常血管直径作为年龄匹配的控制值。</li>
	<li>动脉瘤被定义为主动脉段的局部或弥散扩张, 直径大于参考直径的50%。根据上述测量结果找到这些数据。</li>
</ol>

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作者没有什么可透露的。

微 CT 成像可用于提供高度详细和三维的血管病理重建动物模型。通过使用血管造影增强的培养基, 非增强的软组织, 如血管的流明, 可以区别于那些加强。虽然激光多普勒, microangiography, 磁共振血管造影, 组织学与共焦, 或双光子显微镜可用于评估血管床, 他们通常侧重于有限的研究领域和/或仅限于二维评估。微 CT 提供了一种成本效益高的方法来获得详细的血管结构成像, 这有助于了解潜在的血管生...

主动脉夹层的发生率为3例, 每10万年1。在美国, 主动脉夹层和动脉瘤性疾病每年超过1万人死亡, 占 1-2% 的死亡在西方国家2。主动脉夹层是由血管内膜层撕裂引起的, 在生理压力下通过主动脉壁层的血液传播而引发。患者脉压升高与解剖和并发症发生率增高有关。增加壁面剪应力与主动脉壁扩张有关, 导致动脉瘤形成3,4。主动脉夹层的后果包括阻塞血液流向远端器官, 包括大脑, 肾脏, 内脏和四肢, 形成慢性动脉瘤, 破裂, 或死亡5,6,7。
目前, 在主动脉瘤和解剖的启动和进展中所涉及的生物化学和细胞过程尚不清楚。可再生动物模型的主动脉瘤和解剖是了解其病理生理学的关键。β-aminopropionitrile (BAPN) 是一种赖氨酰氧化酶抑制剂, 它可以防止弹性蛋白和胶原蛋白的交联, 并已被证明大大改变了血管壁细胞外基质的结构及其生物力学完整性6, 8。用 BAPN 治疗的啮齿动物被用作主动脉瘤和解剖9、10的常见动物模型。
血管成像方法有助于识别血管病理, 确认血管通畅, 评价器官灌注。近年来, 微计算机断层扫描 (显微 CT) 已被用来研究小鼠和类似大小动物的血管。与骨不同的是, 血管的轴向成像是有限的, 因为腔内血液本身相对阴性。然而, 当与血管造影剂结合时, 微 CT 可以对动物 vasculatures 进行详细的三维重建, 用于研究宏观解剖血管病理学11。
所选的对比剂 (见材料表) 是一种含有铬酸铅和硫酸铅的显影硅橡胶。在催化剂的存在下灌注时, 它很快硬化形成一个血管的投射, 在血管的宏观解剖结构中最小的改变, 使血管高度显影与背景组织对比时,检查 x 线。这种造影剂是有利的, 因为它易于处理和避免组织退化和船舶损失由于断裂经常与血管铸型腐蚀有关。由于它治愈的最低萎缩12, 血管清除的血液仍然是专利, 并允许准确评估动物宏观血管在非生存实验。以前的工作已经成功地使用了显影硅橡胶-对比在各种动物研究。具体来说, 在可视化冠状动脉, 肾小球, 胎盘和脑循环11,12,13,14,15的适用性已经显示。本文详细介绍了以铅为基础的显影硅橡胶血管内灌注的开放性左心室穿刺方法, 以定量表征 BAPN 诱导的小鼠主动脉病变的显微 CT 表现。

<table>
	<tbody>
		<tr>
			<td>Microfil</td>
			<td>Flow Tech, Inc</td>
			<td>MV-122</td>
			<td>We use yellow, a different color can be ordered as desired. Kit includes MV-Compound, MV-Diluent, and MV-Curing Agent.</td>
		</tr>
		<tr>
			<td>Heparin (1000 U/mL)</td>
			<td>Sagent Pharmaceuticals</td>
			<td>25021-400-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline</td>
			<td>Corning</td>
			<td>21-031-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Vet One, MWI</td>
			<td>502017</td>
			<td></td>
		</tr>
		<tr>
			<td>3-Aminopropionitrile fumarate salt</td>
			<td>Sigma-Aldrich</td>
			<td>A3134</td>
			<td></td>
		</tr>
		<tr>
			<td>Single syringe pump</td>
			<td>Fisher Scientific</td>
			<td>14-831-200</td>
			<td></td>
		</tr>
		<tr>
			<td>27-gauge scalp vein set needle</td>
			<td>Exel Int</td>
			<td>26709</td>
			<td>27G x 3/4&#34;, 12&#34; tube</td>
		</tr>
		<tr>
			<td>Inveon Micro-CT scanner</td>
			<td>Siemens Medical Solutions</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Osirix MD</td>
			<td>Pimxmeo SARL</td>
			<td></td>
			<td>Version 8.0.2</td>
		</tr>
		<tr>
			<td>Inveon Research Workplace</td>
			<td>Siemens Medical Solutions</td>
			<td></td>
			<td>Version 4.2</td>
		</tr>
		<tr>
			<td>Rodent Chow</td>
			<td>Harlan Teklad</td>
			<td>2018sx</td>
			<td></td>
		</tr>
	</tbody>
</table>

quantitative micro-ct analysis of aortopathy in a mouse model of &#946;-aminopropionitrile-induced aortic aneurysm and dissection

主动脉瘤和解剖与人口中严重的发病率和死亡率有关, 而且可能具有极高的致死性。虽然存在主动脉疾病的动物模型, 但在体内成像的血管已经受到限制。近年来, 微电脑断层扫描 (微 CT) 已成为一种在体内和体外成像大、小血管的首选方式. 结合血管铸型的方法, 我们成功地利用微 CT 来表征β-aminopropionitrile 治疗 C57/Bl6 小鼠主动脉病变的频率和分布。这种方法的技术局限性包括: 不良动物制剂所引入的灌注质量的变化, 适用于容器尺寸量化的适当方法, 以及本程序的不可生存性。本文详细介绍了一种以铅为基础的显影硅橡胶血管内灌注的方法, 用于 aortopathy 在动脉瘤和解剖小鼠模型中的定量表征。除了可视化的主动脉病理, 该方法可用于检查其他血管床在体内或血管床切除后的尸体。

为了评估这项议定书, 20 只成年小鼠, 以前描述的混合背景19和 20-30 周的年龄, 有或不 BAPN 治疗, 用铅基显影硅橡胶灌注 (见材料表) 使用上面详细说明的协议。他们在次日进行微 CT 扫描 (图 1和 图 2)。在对照组中, 小鼠的年龄没有显著差异。
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Watch this Scientific Journal Video about Quantitative Micro-CT Analysis of Aortopathy in a Mouse Model of Î²-aminopropionitrile-induced Aortic Aneurysm and Dissection at JoVE.com

Quantitative Micro-CT Analysis of Aortopathy in a Mouse Model of &#946;-aminopropionitrile-induced Aortic Aneurysm and Dissection

本文描述了一个详细的方法, 使用显影铅基硅橡胶灌注小鼠血管的主动脉直径量化的主动脉瘤和解剖模型。

β-aminopropionitrile 诱发主动脉瘤和解剖小鼠模型 Aortopathy 的定量显微 CT 分析

Aortic aneurysm and dissection is associated with significant morbidity and mortality in the population and can be highly lethal. While animal models of ...

quantitative-micro-ct-analysis-aortopathy-mouse-model

Research

JoVE Journal

Medicine

9.5K 次观看.  University of Maryland School of Medicine. 本文描述了一个详细的方法, 使用显影铅基硅橡胶灌注小鼠血管的主动脉直径量化的主动脉瘤和解剖模型。

视频: Quantitative Micro-CT Analysis of Aortopathy in a Mouse Model of β-aminopropionitrile-induced Aortic Aneurysm and Dissection

Quantitative Analysis of Cancer Metastasis using an Avian Embryo Model

During metastasis cancer cells disseminate from the primary tumor, invade into surrounding tissues, and spread to distant organs. Metastasis is a complex process that can involve many tissue types, span variable time periods, and often occur deep within organs, making it difficult to investigate and quantify. In addition, the efficacy of the metastatic process is influenced by multiple steps in the metastatic cascade making it difficult to evaluate the contribution of a single aspect of tumor cell behavior. As a consequence, metastasis assays are frequently performed in experimental animals to provide a necessarily realistic context in which to study metastasis. Unfortunately, these models are further complicated by their complex physiology. The chick embryo is a unique in vivo model that overcomes many limitations to studying metastasis, due to the accessibility of the chorioallantoic membrane (CAM), a well-vascularized extra-embryonic tissue located underneath the eggshell that is receptive to the xenografting of tumor cells (figure 1). Moreover, since the chick embryo is naturally immunodeficient, the CAM readily supports the engraftment of both normal and tumor tissues. Most importantly, the avian CAM successfully supports most cancer cell characteristics including growth, invasion, angiogenesis, and remodeling of the microenvironment. This makes the model exceptionally useful for the investigation of the pathways that lead to cancer metastasis and to predict the response of metastatic cancer to new potential therapeutics. The detection of disseminated cells by species-specific Alu PCR makes it possible to quantitatively assess metastasis in organs that are colonized by as few as 25 cells. Using the Human Epidermoid Carcinoma cell line (HEp3) we use this model to analyze spontaneous metastasis of cancer cells to distant organs, including the chick liver and lung. Furthermore, using the Alu-PCR protocol we demonstrate the sensitivity and reproducibility of the assay as a tool to analyze and quantitate intravasation, arrest, extravasation, and colonization as individual elements of metastasis.

Using quantitative PCR, we demonstrate how the well-established chick CAM model can be used to quantitatively analyze the metastasis of human tumor cells to distant organs.

癌症转移，使用禽流感胚胎模型的定量分析

During metastasis cancer cells disseminate from the primary tumor, invade into surrounding tissues, and spread to distant organs. Metastasis is a complex ...

科研

医学

A New Murine Model of Endovascular Aortic Aneurysm Repair

Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of Abdominal aortic aneurysm (AAA) pathophysiology. There is no abdominal aortic aneurysm endograft exclusion model cheap and reproducible, which would allow deep investigations of AAA before and after treatment. We hereby describe how to induce, and then to exclude with a covered coronary stentgraft an abdominal aortic aneurysm in a rat. The well known elastase induced AAA model was first reported in 19901 in a rat, then described in mice2. Elastin degradation leads to dilation of the aorta with inflammatory infiltration of the abdominal wall and intra luminal thrombus, matching with human AAA. Endovascular exclusion with small covered stentgraft is then performed, excluding any interactions between circulating blood and the aneurysm thrombus. Appropriate exclusion and stentgraft patency is confirmed before euthanasia by an angiography thought the left carotid artery. Partial control of elastase diffusion makes aneurysm shape different for each animal. It is difficult to create an aneurysm, which will allow an appropriate length of aorta below the aneurysm for an easy stentgraft introduction, and with adequate proximal and distal neck to prevent endoleaks. Lots of failure can result to stentgraft introduction which sometimes lead to aorta tear with pain and troubles to stitch it, and endothelial damage with post op aorta thrombosis. Giving aspirin to rats before stentgraft implantation decreases failure rate without major hemorrhage. Clamping time activates neutrophils, endothelium and platelets, and may interfere with biological analysis.

Histological and biochemical modifications after aneurysm endograft exclusion are still unclear. We describe a new model of endograft implantation on a murine aneurysm. Through thrombus analysis with and without persistant circulating blood stream interface, and new endovascular biomaterials evaluation, this model will help to better understand endovascular aneurysm exclusion pathobiology.

一种新的小鼠模型主动脉瘤腔内修复

Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of ...

Quantitative Analysis and Characterization of Atherosclerotic Lesions in the Murine Aortic Sinus

Atherosclerosis is a disease of the large arteries and a major underlying cause of myocardial infarction and stroke. Several different mouse models have been developed to facilitate the study of the molecular and cellular pathophysiology of this disease. In this manuscript we describe specific techniques for the quantification and characterization of atherosclerotic lesions in the murine aortic sinus and ascending aorta. The advantage of this procedure is that it provides an accurate measurement of the cross-sectional area and total volume of the lesion, which can be used to compare atherosclerotic progression across different treatment groups. This is possible through the use of the valve leaflets as an anatomical landmark, together with careful adjustment of the sectioning angle. We also describe basic staining methods that can be used to begin to characterize atherosclerotic progression. These can be further modified to investigate antigens of specific interest to the researcher. The described techniques are generally applicable to a wide variety of existing and newly created dietary and genetically-induced models of atherogenesis.

We describe procedures to quantify and characterize atherosclerotic lesions in mouse models using precision sectioning of the aortic sinus and ascending aorta combined with histochemical and immunohistochemical analysis.

Atherosclerosis is a disease of the large arteries and a major underlying cause of myocardial infarction and stroke. Several different mouse models have ...

Using the Sleeve Technique in a Mouse Model of Aortic Transplantation - An Instructional Video

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the aorta in mice using the sleeve method was short and easy averaging 20 min, permitting studies of iso/allo grafts. The following article describes the aortic transplantation procedure used in our laboratory. The mice were anesthetized with a mixture of 1.5% volume isoflurane and 100% oxygen through a face mask. At this point, the segment of the aorta between the renal arteries and its bifurcation was separated from the vena cava, freely prepared and clampedat the proximal and distal segments with a single silk suture. Prior to the removal of the aorta, a saline solution containing heparin was injected into the inferior vena cava. Then the aorta was cut between the clamps and a saline heparin solution was used to flush the lumen. The sleeve technique with monofilament sutures was used in order to transplant the abdominal aorta in the orthotopic position.

We present an orthotopic aortic transplantation model using the sleeve technique in mice. It is a very rapid anastomosis method, which can be employed in studies of vascular disease.

套筒技术在主动脉移植小鼠模型中的应用-教学视频

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the ...

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at the 12 codon (Ptf1acre/+;LSL-KrasG12D/+) mouse strain as a model of human pancreatic cancer. The goal of our current studies is to identify novel metabolic biomarkers of pancreatic cancer progression. We have performed metabolic profiling of urine, feces, blood, and pancreas tissue extracts, as well as histological analyses of the pancreas to stage the cancer progression. The mouse pancreas is not a well-defined solid organ like in humans, but rather is a diffusely distributed soft tissue that is not easily identified by individuals unfamiliar with mouse internal anatomy or by individuals that have little or no experience performing mouse organ dissections. The purpose of this article is to provide a detailed step-wise visual demonstration to guide novices in the removal of the mouse pancreas by dissection. This article should be especially valuable to students and investigators new to research that requires harvesting of the mouse pancreas by dissection for metabolic profiling or histological analyses.

This video article provides a detailed demonstration of the procedures required to successfully remove the pancreas from a mouse by dissection for histological analysis and metabolic profiling.

解剖的小鼠胰腺的组织学分析与代谢谱

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at ...

Creation of a Rodent Model of Abdominal Aortic Aneurysm by Blocking Adventitial Vasa Vasorum Perfusion

The adventitial vasa vasorum (VV) provides oxygen and nourishment to the aortic wall. Hypoxia in the aortic wall can cause enlarged abdominal aortic aneurysms (AAAs). This article introduces and describes a standard protocol used to induce AAAs through adventitial VV hypoperfusion created with a combination of polyurethane catheter insertion into the aortic lumen and suture ligation of the infrarenal abdominal aorta.
The protocol involves the use of male rats weighing 300-400 g, which are provided food and water ad libitum. After laparotomy with a ventral midline abdominal incision, exfoliation of the aorta is performed, which blocks blood flow from the perivascular tissue. Aortotomy involving a small incision adjacent to the renal artery branches is performed, and a polyurethane catheter is inserted using an 18-gauge indwelling needle. After repairing the incision, tight ligation of the aorta over the catheter blocks VV blood flow from the proximal direction through the aortic wall without disturbing the aortic blood flow. This technique can induce an AAA with progressive aortic dilatation.
The greatest benefit of this model is that VV hypoperfusion causes tissue hypoxia and the development of an infrarenal AAA, which has morphological and pathological characteristics similar to those of a human AAA.

Polyurethane catheter insertion into the aortic lumen and suture ligation of the aorta induce chronic hypoxia due to hypoperfusion of the adventitial vasa vasorum. This article describes a novel animal model of abdominal aortic aneurysm (AAA) with characteristics similar to those of AAA in humans.

阻断外瓦萨血管灌注对腹主动脉瘤鼠模型的建立

The adventitial vasa vasorum (VV) provides oxygen and nourishment to the aortic wall. Hypoxia in the aortic wall can cause enlarged abdominal aortic ...

Induction and Micro-CT Imaging of Cerebral Cavernous Malformations in Mouse Model

Mutations in the CCM1 (aka KRIT1), CCM2, or CCM3 (aka PDCD10) gene cause cerebral cavernous malformation (CCM) in humans. Mouse models of CCM disease have been established by tamoxifen induced deletion of Ccm genes in postnatal animals. These mouse models provide invaluable tools to investigate molecular mechanism and therapeutic approaches for CCM disease. An accurate and quantitative method to assess lesion burden and progression is essential to harness the full value of these animal models. Here, we demonstrate the induction of CCM disease in a mouse model and the use of the contrast enhanced X-ray micro computed tomography (micro-CT) method to measure CCM lesion burden in mouse brains. At postnatal day 1 (P1), we used 4-hydroxytamoxifen (4HT) to activate Cre recombinase activity from the Cdh5-CreErt2 transgene to cleave the floxed allele of Ccm2. CCM lesions in mouse brains were analyzed at P8. For micro-CT, iodine based Lugol&#39;s solution was used to enhance contrast in brain tissue. We have optimized the scan parameters and utilized a voxel dimension of 9.5 &#181;m, which lead to a minimum feature size of approximately 25 &#181;m. This resolution is sufficient to measure CCM lesion volume and number globally and accurately, and provide high-quality 3-D mapping of CCM lesions in mouse brains. This method enhances the value of the established mouse models to study the molecular basis and potential therapies for CCM and other cerebrovascular diseases.

This protocol demonstrates the induction of cerebral cavernous malformation disease in a mouse model and uses contrast enhanced micro computed tomography to measure lesion burden. This method enhances the value of established mouse models to study the molecular basis and potential therapies for cerebral cavernous malformation and other cerebrovascular diseases.

小鼠脑海绵体畸形的诱导及显微 CT 成像

Mutations in the CCM1 (aka KRIT1), CCM2, or CCM3 (aka PDCD10) gene cause cerebral cavernous malformation (CCM) in humans. Mouse models of CCM disease have ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

用线 Myography 测定小鼠肠系膜动脉的等轴收缩力

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Murine Surgical Model of Topical Elastase Induced Descending Thoracic Aortic Aneurysm

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. An aneurysm forms as a result of progressive weakening and eventual dilation of the aorta, which can rupture or tear once it reaches a critical diameter. Aneurysms of the descending aorta in the chest, called descending thoracic aortic aneurysms (dTAA), make up a large proportion of aneurysm cases in the United States. Uncontained dTAA rupture is almost universally lethal, and elective repair has a high rate of morbidity and mortality. The purpose of our model is to study dTAA specifically, to elucidate the pathophysiology of dTAA and to search for molecular targets to halt the growth or reduce the size of dTAA. By having a murine model to study thoracic pathology precisely, targeted therapies can be developed to specifically test dTAA. The method is based on the placement of porcine pancreatic elastase (PPE) directly on the outer murine aortic wall after surgical exposure. This creates a destructive and inflammatory reaction, which weakens the aortic wall and allows for aneurysm formation over weeks to months. Though murine models possess limitations, our dTAA model produces robust aneurysms of predictable size. Furthermore, this model can be used to test genetic and pharmaceutical targets which may arrest dTAA growth or prevent rupture. In human patients, interventions such as these could help avoid aneurysm rupture, and difficult surgical intervention.

We describe a surgical protocol to consistently induce robust descending thoracic aortic aneurysms in mice. The procedure involves left thoracotomy, thoracic aorta exposure, and placement of a sponge soaked in porcine pancreatic elastase on the aortic wall.

局部性乳酸酶诱导下降胸腔主动脉瘤的毛尿外科模型

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. ...

Porcine Model of Infrarenal Abdominal Aortic Aneurysm

Large animal models to study abdominal aortic aneurysms are sparse. The purpose of this model is to create reproducible, clinically significant infrarenal abdominal aortic aneurysms (AAA) in swine. To achieve this, we use a combination of balloon angioplasty, elastase and collagenase, and a lysyl oxidase inhibitor, called &#946;-aminopropionitrile (BAPN), to create clinically significant infrarenal aortic aneurysms, analogous to human disease.
Noncastrated male swine are fed BAPN for 7 days prior to surgery to achieve a steady state in the blood. A midline laparotomy is performed and the infrarenal aorta is circumferentially dissected. An initial measurement is recorded prior to aneurysm induction with a combination of balloon angioplasty, elastase (500 units)/collagenase (8000 units) perfusion, and topical elastase application. Swine are fed BAPN daily until terminal procedure on either postoperative day 7, 14, or 28, at which time the aneurysm is measured, and tissue procured. BAPN + surgery pigs are compared to pigs that underwent surgery alone.
Swine treated with BAPN and surgery had a mean aortic dilation of 89.9% &#177; 47.4% at day 7, 105.4% &#177; 58.1% at day 14, and 113.5% &#177; 30.2% at day 28. Pigs treated with surgery alone had significantly smaller aneurysms compared to BAPN + surgery animals at day 28 (p &#60; 0.0003). The BAPN + surgery group had macroscopic and immunohistochemical evidence of end stage aneurysmal disease.
Clinically significant infrarenal AAA can be induced using balloon angioplasty, elastase/collagenase perfusion and topical application, supplemented with oral BAPN. This model creates large, clinically significant AAA with hallmarks of human disease. This has important implications for the elucidation of AAA pathogenesis and testing of novel therapies and devices for the treatment of AAA. Limitations of the model include variation in BAPN ingested by swine, quality of elastase perfusion, and cost of BAPN.&#160;

This novel model creates robust infrarenal abdominal aortic aneurysms in swine using a combination of balloon angioplasty, elastase/collagenase perfusion, topical elastase application, and oral compound &#946;-aminopropionitrile administration, which interferes with collagen cross-linking.

肾上腺腹动脉瘤的猪模型

Large animal models to study abdominal aortic aneurysms are sparse. The purpose of this model is to create reproducible, clinically significant infrarenal ...