The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme [FP7/2007-2013] / ERC grant agreement [337333]. The research of SvV and GJB is supported by a VIDI grant [91711384] from ZonMw, the Netherlands Organization for Health Research and Development.

使用尸检标本和活体 MR图像此协议是符合当地法规并经大学医学中心的乌得勒支（UMCU）的当地机构审查委员会。 1.磁共振引导皮质Microinfarcts的组织病理学检验<ol><li> 体外 MRI <ol><li>在处理脑组织，一定要穿戴手套和适当的防护服。 </li><li>根据研究问题，选择合适的，最好是10毫米厚，福尔马林固定大脑板。大脑板对本文均来自UMCU的神经病理学部门，VU大学医学中心（VUMC），根据已知的阿尔茨海默氏症的病理。 <ol><li>通过浸渍在10％的福尔马林福尔马林固定全脑为至少3-4周，在切割之前。切大脑进入冠状板，包含两个半球。 </li><li>对于验尸扫描，选择例如三个脑SLA每脑BS，从正面，颞顶骨和脑的枕骨区域采取。当前协议是为使用三个冠状脑板坯优化，含有两个半球，在一个扫描会话。 </li></ol></li><li>取脑板坯的照片在两侧（背和尾），并采取谨慎音符（或使草图）在容器中，并在扫描器板坯的取向的，购买的共定位的组织学的MRI。 </li><li>填写一个特制的容器（ 图1） -在这种情况下，一个适合MR磁头线圈中-用10％福尔马林保鲜室温。如果从流体MRI信号是不希望使用全氟聚醚（PFPE）润滑剂用合适的密度，而不是福尔马林（如的Fomblin或热传导液PFPE）。确保处理福尔马林时使用一个流柜。 </li><li>当放置在容器中的大脑砖，一定要避免气泡。轻轻去除大部分气泡萨基纳克的组织，或者通过手，或者使用振动筛或超声波浴中。 </li><li>确保板坯不能在容器内移动，并限制所需要的流体的量，通过使用更小的容器，以保持板坯到位（ 图1）。 </li><li>覆盖容器用塑料或封口膜，以防止蒸发，并保护从潜在污染（图2）对MR（头）线圈。 </li><li>使用全身7T MRI扫描器与适当的线圈。在这个协议中一个双重的发送和32通道接收头线圈被使用。 </li><li>将容器中的磁头线圈，裹在毛巾或手术底垫，以防止流体的潜在溢出。确保容器不能移动，并且该板保持在水平位置（图2）。 </li><li>运行可通过使用适当的垫补工具被用于高分辨率扫描，正确B0不均匀的规划的调查扫描，并校准RF功​​率以获得正确的翻转角（少数板坯需要更少的功率相比在体内扫描整个头部的）根据制造商的协议。 </li><li>计划调查扫描高分辨率收购，以确保大脑板坯完全包含在场-的图。扫描脑板坯O / N与表1中所示的分辨率高的收购，这是用于离体成像优化。这里提出的获取协议包括具有各向同性分辨率为0.4mm，以及一个T2 *加权的图像以0.18毫米的各向同性分辨率的三维FLAIR，T2和T1加权图像。 </li><li>自动识别软件进程，可能会中断扫描，如运行O / N自动向上日期，或末梢神经的刺激警告，并确保扫描仪的程序不会被这些中断。 </li><li>监控扫描仪O / N为可能确认的弹出窗口，可能会中断扫描，通过使用例如VPN连接。</li><li>返回第二天上午（后在当前的协议大约12小时的总扫描时间）。存放于福尔马林大脑砖，清理。 </li><li>保存图像到外部硬盘。 </li></ol></li></ol><img alt="图1" src="/files/ftp_upload/53125/53125fig1.jpg" /> 图1.制备福尔马林固定脑板坯进行事后扫描在7T的MRI。甲专门建造的有机玻璃容器中填充为10％福尔马林或全氟聚醚（PFPE）润滑剂，如果从该流体的MRI信号是不希望的。三个10毫米厚的福尔马林固定冠状脑板坯放置在容器中。较小的容器用来保持板坯到位。用胶带将第二容器的第一个，以防止移动。 <img alt="图2" src="/files/ftp_upload/53125/53125fig2.jpg" /> 图2.放置在7T头部线圈的专用容器。盖上容器用塑料或封口膜，以防止福尔马林的蒸发。将容器，包在毛巾或手术焊，在7T磁共振扫描仪的头部线圈。确保容器不能移动，并且该板保持在水平位置。 <ol start="2"><li>组织病理学<ol><li>确定可能的皮质中药注射剂 - 或感兴趣的其他病变 - 对采集的图像。这些病变组织学分析的目标。当心工件，如验尸组织损伤（有时因削减出现在大脑砖的表面）或长期福尔马林保存的文物（ 如粗MRI低信号代表神经纤维的改变8）。 注：皮质中药注射剂的不同病理亚型有不同的MR特性。有关的CMI亚型进一步的细节，读者可参考最近的体外研究7。 </li><li>房颤之三确定的MR图像可能皮质中药注射剂，试样的病理验证感兴趣的区域。请一定要切出一个区域，包括解剖标志，用于组织病理学磁共振成像以后匹配。执行标准组织病理学，作为跟随（但其他的方法也可能适用）。 </li><li>切出的约30×20×5毫米3含有可能皮层的CMI的区域。 </li><li>为了获得准确的采样，通过切片厚度的磁共振图像，以及组织架构估计病变的部位。手动切割组织略高于估计病灶位置以限制是需要靶向病变连续切片（石蜡包埋后）的量。 </li><li>确保采样组织适合一个组织盒。放置表面要在盒切割面朝下。 </li><li>保留所有组织盒中10％的甲醛，直至组织处理。 </li><li>过程中组织进行石蜡包埋。这通常涉及脱水组织，通过一系列梯度酒精（例如，70％至95％至100％）浴，并清除在二甲苯的组织的的一种自动化过程。 </li><li>嵌入石蜡块中的组织。保证嵌入后的表面进行切割朝上。 </li><li>切4-6微米连续切片用切片机，直至靶疾患检索。 </li><li>浮动的37℃水浴表面上的部分。安装在载玻片上的部分。放置一个变暖块上的滑动来接合组织，以在玻璃上。商店幻灯片O / N在室温。 </li><li>执行的第一个部分一个合适的染色（ 如 H＆E染色），让相邻的空白部分用于再使用 （例如，免疫组化）。 </li><li>盖玻片的H＆E染色切片，用一滴安装选择介质。轻轻放下防滑，避免产生气泡。 </li><li>研究使用光学显微镜的部分中，在一个适当的磁nification。部分比较先前获得的MR图像。 </li></ol></li></ol> 2.评估皮质Microinfarcts 对体内7T磁共振成像<ol><li>在您感兴趣的患者群体进行7T的MRI，使用如6所述的体内 MRI方案（其包括至少一个三维FLAIR）。 </li><li>评估如在下面的步骤中详述的体内 7T MR图像皮质中药注射剂，使用以下7T评级标准中药注射剂：皮质中药注射剂是高信号上FLAIR（具有或不具有低信号中心），高信号在T2，低信号在T1，可检测的上的至少两个视图的脑（例如，矢状和横向）的，仅限于皮质，从血管周围间隙不同，具有最大尺寸≤4毫米6,7。 </li><li>使用接口具有三个图像的观众，同时查看FLAIR，T1和T2的图像，例如，MeVisLab（图3）。该平台异体WS地将多个观众，并把可能的病变部位的位置标记。 </li><li>首先评估一个半球FLAIR上矢状视图。屏幕全皮质的高信号病灶。任何hyperintens病变≤4毫米是一个可能的CMI。通过点击每一个可能的CMI位置标记。 </li><li>重复另一半球。 </li><li>验证在T1和T2的所有标记的​​位置。丢弃一个位置，如果它不是低信号T1或高信号在T2。 </li><li>评估横向视图中，FLAIR，T1和T2。丢弃一个位置，如果它是不可见的。检查中如有疑问冠状视图。 </li><li>当心MRI伪影和解剖变异（尤其是脑沟的边缘）。 </li><li>保存标记。 </li></ol><img alt="图3" src="/files/ftp_upload/53125/53125fig3.jpg" /> 图3.示例图像浏览平台皮质microinfarcts的评估。接口时，INTegrated在MeVisLab。这个程序允许同时将多个观众，矢状/横向/冠状方向之间轻松切换，并把和节省可能的病变位置标记。 （不同的标记，可以选择不同类型的病灶）。 3.评估皮质Microinfarcts 对体内3T MRI <ol><li>获取您感兴趣的患者人群的3T磁共振图像。现有的数据也可以只要该MR成像协议中包含的至少一个三维T1和一个FLAIR和T2使用。 </li><li>评估皮质中药注射剂上，如下面的步骤中详述的体内 3T MR图像，使用以下3T评级标准中药注射剂：皮质中药注射剂是低信号在T1（等信号与CSF），可检测的至少两个视图的大脑（例如矢状和横向），限制到皮质，从血管周围间隙不同，具有最大尺寸≤4毫米。 <ol><li>探索一个hypoint的位置恩瑟皮质病变发现T1的风格和T2加权像。评价病变为可能的皮质CMI如果该位置上的天赋和T2高或等信号（与灰质）。丢弃病变如果在同一位置一低信号被发现在T2，表示T1低信号病变或者是由于出血性病变，血管，或工件。如有疑问，请查看位置上的T2 *加权图像9。 </li></ol></li><li>使用相同的接口，如上所述。 </li><li>首先评估一个半球在T1矢状视图。屏幕全皮质局灶性低信号病变。任何低信号病​​灶≤4毫米是一个可能的CMI。通过点击每一个可能的CMI位置标记。 </li><li>重复另一半球。 </li><li>评估横向T1，同时核实横向FLAIR和T2的所有标记的​​位置。关于该位置作为一个可能的CMI如果是高信号或等信号的FLAIR和T2。放弃一个位置我F IT似乎是一个假象或解剖变异。丢弃的位置，如果它是低信号T2。 </li><li>当心工件看起来像在T1加权图像中药注射剂，特别是在其中将出现在几个相邻的脑回，注意沟的边缘大脑的“边缘”的环状假象，注意大血管中的颞叶（在两极）。最后，建议丢弃在组织可能皮质中药注射剂在靠近较大皮质梗塞。 </li><li>保存标记。 </li></ol>

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The authors have nothing to disclose.

中药注射剂已经​​吸引了越来越多的关注，在过去的几年里。证据尸检研究中获得越来越多的身体已经确定中药注射剂的重要贡献者与年龄有关的认知能力下降和痴呆4,5。中药注射剂是现在检测的7T，也3T MRI检查。优化和评估协议，这些病变的标准化将支持迅速执行稳健和有效的CMI检测的队列研究在世界各地。这将使中药注射剂的老化，脑血管疾病的上下文中的临床相关的在未来的临床...

超高场7特斯拉（T）MRI检查的患者研究中的应用正在迅速发展1。本文介绍7T磁共振脑血管疾病的老化人脑的范围内有代表性的应用程序。脑血管疾病是认知衰退和痴呆的主要原因。这对血管性痴呆贡献经常涉及脑的小血管，如动脉，小静脉和毛细血管。因此，它被称为脑小血管疾病（SVD）2。因为脑小血管太小捕获与常规MRI，SVD只有后果- 即，所得到的组织损伤-可以被可视化。这包括白质高信号，脑微出血和腔隙性梗死3。 SVD的其他重要表现是脑microinfarcts（CMIS）4。尸检研究报道的中药注射剂在VASC高患病率ular痴呆和阿尔茨海默氏病5。然而，由于它们的小尺寸（范围从50微米到几个毫米）他们逃过检测上常规MRI 4,5。 7T的MRI提供具有改进的信号与噪声比和对比度，这使得某些结构和病变超越常规MRI的检测极限的检测高分辨率的图像。因此，该技术应用于检测中药注射剂。为了找出可能的中药注射剂，多在体内 7T核磁共振成像扫描了以前的病变筛查与尺寸&lt;缺血性一致5毫米的影像学特征。这种病变可以可靠地在皮层被识别。这些联络拉长病变呈高信号的7T FLAIR（0.8毫米各向同性体素），受限于皮层，似乎从皮质表面延伸，高信号，在T2（0.7毫米各向同性体素），以及低信号T1（1.0毫米各向同性体素）。经证实，这些病变是使用皮质中药注射剂MR引导组织病理学方法在验尸人脑组织6,7。 在此， 离体 MRI方案，提出了用在以前的研究中对皮质中药注射剂的组织病理学验证。其次，提供了用于皮质中药注射剂在体内对7T的MRI评估准则。最后，皮质中药注射剂在7T的评估已被翻译为更广泛地提供3T MRI，并提供指导如何识别3T MRI皮质中药注射剂。

<table border="0">
	<tbody>
		<tr>
			<td>Fomblin / Galden PFPE</td>
			<td>Solvay Solexis, Bollate, Italy</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>7T MR system</td>
			<td>Philips Healthcare, Cleveland, OH, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>32-channel receive head coil</td>
			<td>Nova Medical, Wilmington, MA, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>MeVisLab</td>
			<td>MeVis Medical Solutions AG, Bremen, Germany</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

assessing cortical cerebral microinfarcts on high resolution mr images

脑microinfarcts频繁发现在验尸人脑，并与认知能力下降和痴呆。由于其尺寸小​​是具有挑战性的研究他们在临床MRI扫描。这是最近证实，皮质microinfarcts可以采用高磁场强度（7T），核磁共振成像扫描仪来描述。在此基础上的经验，这些病变的比例也较低分辨率的3T MRI可见。这些研究结果证实与死后的人脑组织的体外成像，伴随着可能的皮质microinfarcts病理组织学检验。 这里离体成像协议，提出，用于验证的MR观察脑微血管病理组织学评估的目的。此外，提供了用于在两个体内 7T和3T MR图像皮质microinfarcts的评估准则。这些准则为研究人员提供W¯¯第i个工具率在体内图像较大患者样本皮质microinfarcts，进一步揭开其临床意义的认知功能减退和老年痴呆症，并在这些病变作为一种新型的脑小血管疾病的生物标志物。

高分辨率和在7T提供获得离体序列的高图像质量的印象<a href="https://www.jove.com/files/ftp_upload/53125/53125fig4.mp4" target="_blank">这里（图4）。</a>这是一个三维的T2 *加权的离体的扫描，以0.18毫米的各向同性分辨率。组织来源于一个84岁的痴呆症的女性经病理证实为阿尔茨海默氏症和严重的脑淀粉样血管病（CAA）。图像的细节允许皮质微血管病理的鉴定。 T2 *是易感的铁，以及空气。该组织含有...

Watch this Scientific Journal Video about Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images at JoVE.com

Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images

高分辨率体外 7T磁共振成像协议提出，在验尸人脑组织进行微血管病变的MR引导组织病理学检验。此外，提供了用于在体内对7T皮质microinfarcts以及3T MR图像的评估准则。

评估皮层脑Microinfarcts高分辨率核磁共振图像

Cerebral microinfarcts are frequent findings in the post-mortem human brain, and are related to cognitive decline and dementia. Due to their small sizes ...

assessing-cortical-cerebral-microinfarcts-on-high-resolution-mr-images

Research

JoVE Journal

Medicine

13.3K 次观看.  University Medical Center Utrecht. 高分辨率体外 7T磁共振成像协议提出，在验尸人脑组织进行微血管病变的MR引导组织病理学检验。此外，提供了用于在体内对7T皮质microinfarcts以及3T MR图像的评估准则。 

视频: Assessing Cortical Cerebral Microinfarcts on High Resolution MR Images

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.

高频超声心动图：非侵入性的反复测量小鼠心脏缺血再灌注心肌劳损，收缩力，二尖瓣关闭不全的第一个证据

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

科研

医学

How to Measure Cortical Folding from MR Images: a Step-by-Step Tutorial to Compute Local Gyrification Index

Cortical folding (gyrification) is determined during the first months of life, so that adverse events occurring during this period leave traces that will be identifiable at any age. As recently reviewed by Mangin and colleagues2, several methods exist to quantify different characteristics of gyrification. For instance, sulcal morphometry can be used to measure shape descriptors such as the depth, length or indices of inter-hemispheric asymmetry3. These geometrical properties have the advantage of being easy to interpret. However, sulcal morphometry tightly relies on the accurate identification of a given set of sulci and hence provides a fragmented description of gyrification. A more fine-grained quantification of gyrification can be achieved with curvature-based measurements, where smoothed absolute mean curvature is typically computed at thousands of points over the cortical surface4. The curvature is however not straightforward to comprehend, as it remains unclear if there is any direct relationship between the curvedness and a biologically meaningful correlate such as cortical volume or surface. To address the diverse issues raised by the measurement of cortical folding, we previously developed an algorithm to quantify local gyrification with an exquisite spatial resolution and of simple interpretation. Our method is inspired of the Gyrification Index5, a method originally used in comparative neuroanatomy to evaluate the cortical folding differences across species. In our implementation, which we name local Gyrification Index (lGI1), we measure the amount of cortex buried within the sulcal folds as compared with the amount of visible cortex in circular regions of interest. Given that the cortex grows primarily through radial expansion6, our method was specifically designed to identify early defects of cortical development.
In this article, we detail the computation of local Gyrification Index, which is now freely distributed as a part of the FreeSurfer Software (<a href="http://surfer.nmr.mgh.harvard.edu/">http://surfer.nmr.mgh.harvard.edu/</a>, Martinos Center for Biomedical Imaging, Massachusetts General Hospital). FreeSurfer provides a set of automated reconstruction tools of the brain's cortical surface from structural MRI data. The cortical surface extracted in the native space of the images with sub-millimeter accuracy is then further used for the creation of an outer surface, which will serve as a basis for the lGI calculation. A circular region of interest is then delineated on the outer surface, and its corresponding region of interest on the cortical surface is identified using a matching algorithm as described in our validation study1. This process is repeatedly iterated with largely overlapping regions of interest, resulting in cortical maps of gyrification for subsequent statistical comparisons (Fig. 1). Of note, another measurement of local gyrification with a similar inspiration was proposed by Toro and colleagues7, where the folding index at each point is computed as the ratio of the cortical area contained in a sphere divided by the area of a disc with the same radius. The two implementations differ in that the one by Toro et al. is based on Euclidian distances and thus considers discontinuous patches of cortical area, whereas ours uses a strict geodesic algorithm and include only the continuous patch of cortical area opening at the brain surface in a circular region of interest.

Measuring gyrification (cortical folding) at any age represents a window into early brain development. Hence, we previously developed an algorithm to measure local gyrification at thousands of points over the hemisphere1. In this paper, we detail the computation of this local gyrification index.

如何从MR图像测量皮质折叠：一个循序渐进的教程，以计算本地Gyrification指数

Cortical folding (gyrification) is determined during the first months of life, so that adverse events occurring during this period leave traces that will ...

Automated Midline Shift and Intracranial Pressure Estimation based on Brain CT Images

In this paper we present an automated system based mainly on the computed tomography (CT) images consisting of two main components: the midline shift estimation and intracranial pressure (ICP) pre-screening system. To estimate the midline shift, first an estimation of the ideal midline is performed based on the symmetry of the skull and anatomical features in the brain CT scan. Then, segmentation of the ventricles from the CT scan is performed and used as a guide for the identification of the actual midline through shape matching. These processes mimic the measuring process by physicians and have shown promising results in the evaluation. In the second component, more features are extracted related to ICP, such as the texture information, blood amount from CT scans and other recorded features, such as age, injury severity score to estimate the ICP are also incorporated. Machine learning techniques including feature selection and classification, such as Support Vector Machines (SVMs), are employed to build the prediction model using RapidMiner. The evaluation of the prediction shows potential usefulness of the model. The estimated ideal midline shift and predicted ICP levels may be used as a fast pre-screening step for physicians to make decisions, so as to recommend for or against invasive ICP monitoring.

An automated midline shift estimation and intracranial pressure (ICP) pre-screening system based on computed tomography (CT) images for patients with traumatic brain injury (TBI) is proposed using image processing and machine learning techniques.

根据脑CT图像的自动中线移位和颅内压的估计

In this paper we present an automated system based mainly on the computed tomography (CT) images consisting of two main components: the midline shift ...

Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which disrupt normal brain function. Despite treatment with currently available antiepileptic drugs targeting neuronal functions, one third of patients with epilepsy are pharmacoresistant. In this condition, surgical resection of the brain area generating seizures remains the only alternative treatment. Studying human epileptic tissues has contributed to understand new epileptogenic mechanisms during the last 10 years. Indeed, these tissues generate spontaneous interictal epileptic discharges as well as pharmacologically-induced ictal events which can be recorded with classical electrophysiology techniques. Remarkably, multi-electrode arrays (MEAs), which are microfabricated devices embedding an array of spatially arranged microelectrodes, provide the unique opportunity to simultaneously stimulate and record field potentials, as well as action potentials of multiple neurons from different areas of the tissue. Thus MEAs recordings offer an excellent approach to study the spatio-temporal patterns of spontaneous interictal and evoked seizure-like events and the mechanisms underlying seizure onset and propagation. Here we describe how to prepare human cortical slices from surgically resected tissue and to record with MEAs interictal and ictal-like events ex vivo.

We here describe how to perform multi-electrode array recordings of human epileptic cortical tissue. Epileptic tissue resection, slice preparation and multi-electrode array recordings of interictal and ictal events are demonstrated in detail.

人类癫痫术后皮层组织的多电极阵列录音

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which ...

A Thrombotic Stroke Model Based On Transient Cerebral Hypoxia-ischemia

Stroke research has endured many setbacks in translating neuroprotective therapies into clinical practice. In contrast, the real-world therapy (tPA thrombolysis) rarely produces benefits in mechanical occlusion-based experimental models, which dominate preclinical stroke research. This split between the bench and bedside suggests the need to employ tPA-responsive models in preclinical stroke research. To this end, a simple and tPA-reactive thrombotic stroke model is invented and described here. This model consists of transient occlusion of the unilateral common carotid artery and delivery of 7.5% oxygen through a face mask in adult mice for 30 min, while maintaining the animal rectal temperature at 37.5 &#177; 0.5 &#176;C. Although reversible ligation of the unilateral carotid artery or hypoxia each suppressed cerebral blood flow only transiently, the combination of both insults caused lasting reperfusion deficits, fibrin and platelet deposition, and large infarct in the middle cerebral artery-supplied territory. Importantly, tail-vein injection of recombinant tPA at 0.5, 1, or 4 hr post-tHI (10 mg/kg) provided time-dependent reduction of the mortality rate and infarct size. This new stroke model is simple and can be standardized across laboratories to compare experimental results. Further, it induces thrombosis without craniectomy or introducing pre-formed emboli. Given these unique merits, the tHI model is a useful addition to the repertoire of preclinical stroke research.

Thromboembolic stroke models are vital tools for optimizing the recanalization therapy. Here we report a murine thrombotic stroke model based on transient cerebral hypoxic-ischemic (tHI) insult, which triggers thrombosis and infarction, and responds favorably to tissue plasminogen activator (tPA)-mediated fibrinolysis in a therapeutic window similar to those in stroke patients.

基于短暂性脑缺氧缺血性血栓性中风模型

Stroke research has endured many setbacks in translating neuroprotective therapies into clinical practice. In contrast, the real-world therapy (tPA ...

Performing Permanent Distal Middle Cerebral with Common Carotid Artery Occlusion in Aged Rats to Study Cortical Ischemia with Sustained Disability

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, obesity and diabetes. Accordingly, when evaluating therapies for stroke in animals, it is important to select a model with excellent face validity. Ischemic stroke accounts for 80% of all strokes, and the majority of these occur in the territory of the middle cerebral artery (MCA), often inducing infarcts that affect the sensorimotor cortex, causing persistent plegia or paresis on the contralateral side of the body. We demonstrate in this video a method for producing ischemic stroke in elderly rats, which causes sustained sensorimotor disability and substantial cortical infarcts. Specifically, we induce permanent distal middle cerebral artery occlusion (MCAO) in elderly female rats by using diathermy forceps to occlude a short segment of this artery. The carotid artery on the ipsilateral side to the lesion was then permanently occluded and the contralateral carotid artery was transiently occluded for 60 min. We measure the infarct size using structural T2-weighted magnetic resonance imaging (MRI) at 24 hr and 8 weeks after stroke. In this study, the mean infarct volume was 4.5% &#177; 2.0% (standard deviation) of the ipsilateral hemisphere at 24 hr (corrected for brain swelling using Gerriet&#8217;s equation, n = 5). This model is feasible and clinically relevant as it permits the induction of sustained sensorimotor deficits, which is important for the elucidation of pathophysiological mechanisms and novel treatments.

Here we present a protocol to produce permanent distal middle cerebral artery occlusion in elderly female rats with simultaneous occlusion of the carotid arteries to generate large cortical infarcts and sustained deficits. We show confirmation of the lesion size using structural MRI at 24 hr and 8 weeks after stroke.

执行永久远端大脑中与老年大鼠颈总动脉闭塞研究皮层缺血具有持续残疾

Stroke typically occurs in elderly people with a range of comorbidities including carotid (or other arterial) atherosclerosis, high blood pressure, ...

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts. The optical mapping system is assembled with dual high-speed complementary metal oxide semiconductor cameras and high magnification objective lenses, to detect the fluorescence of a voltage-sensitive dye and Ca2+ indicator. To focus on the assessment of murine atria, optical mapping is performed with an area of 2 mm &#215; 2 mm or 10 mm x 10 mm, with a 100 &#215; 100 resolution (20 &#181;m/pixel or 100 &#181;m/pixel) and sampling rate of up to 10 kHz (0.1 ms) at maximum. A 1-French size quadripolar electrode pacing catheter is placed into the right atrium through the superior vena cava avoiding any mechanical damage to the atrium, and pacing stimulation is delivered through the catheter. An electrophysiological study is performed with programmed stimulation including constant pacing, burst pacing, and up to triple extrastimuli pacing. Under a spontaneous or pacing rhythm, the optical mapping recorded the action potential duration, activation map, conduction velocity, and Ca2+ transient individually in the right and left atria. In addition, the programmed stimulation also determines the inducibility of atrial tachyarrhythmias. Precise activation mapping is performed to identify the propagation of the excitation in the atrium during an induced atrial tachyarrhythmia. Optical mapping with a specialized setting enables a thorough electrophysiological evaluation of the atrium in murine pathological models.

This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter.

高分辨率光学制图对小鼠心房电生理的评价

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and ...

Assessing Neuroprotective Effects of Glycyrrhizae Radix et Rhizoma Extract Using a Transient Middle Cerebral Artery Occlusion Mouse Model

Ischemia followed by reperfusion of cerebral blood flow after a stroke leads to the death of nerve cells and loss of brain tissue. The most commonly used animal model for studying stroke is the middle cerebral artery occlusion (MCAO) model. Previous research studies have reported different infarct sizes even when the same experimental animal species was used under similar MCAO conditions. Therefore, we developed an improved experimental method to address this discrepancy. Mice were subjected to MCAO using a filament as the occlusion material to mimic human stroke conditions and filament thickness was optimized to establish more reproducible infarction volume. Mice treated with a methanol extract of Glycyrrhizae Radix et Rhizome (GRex) following stroke induction showed a significantly decreased total infarction volume and increased number of surviving cells relative to the untreated control group. This modified experimental protocol successfully and reproducibly demonstrated the beneficial effect of GRex on ischemic stroke.

In this study, we modify an existing experimental method to obtain more reproducible results, by establishing a middle cerebral artery occlusion (MCAO) mouse model. Oral administration of Glycyrrhizae Radix et Rhizome (GR) methanol extract (GRex), following stroke induction, significantly decreased total infarction volume relative to the untreated control group.

应用短暂的中脑动脉闭塞小鼠模型评价甘草提取物的神经保护作用

Ischemia followed by reperfusion of cerebral blood flow after a stroke leads to the death of nerve cells and loss of brain tissue. The most commonly used ...

High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding cardiac function and metabolism. In preclinical research, dedicated scanners with high sensitivity and high spatio-temporal resolution are employed, designed to cope with the demanding technological requirements posed by the small heart size and very high heart rates of mice and rats. In this paper, a bimodal cardiac PET/CT imaging protocol for experimental mouse and/or rat models of cardiac diseases is described, from animal preparation and image acquisition and reconstruction to image processing and visualization.
In particular, the 18F-labeled fluorodeoxyglucose ([18F]FDG)-PET scan allows for the measurement and visualization of glucose metabolism in the different segments of the left ventricle (LV). Polar maps are convenient tools to display this information. The CT part consists of a time-resolved 3D reconstruction of the entire heart (4D-CT) using retrospective gating without electrocardiography (ECG) leads, allowing the morphofunctional evaluation of the LV and the subsequent quantification of the most important cardiac function parameters, such as ejection fraction (EF) and stroke volume (SV). Using an integrated PET/CT scanner, this protocol can be executed within the same anesthesia induction without the need to reposition the animal between different scanners. Hence, PET/CT can be seen as a comprehensive tool for the morphofunctional and metabolic evaluation of the heart in several small animal models of cardiac diseases.

Here, we present an experimental imaging protocol for the quantification of cardiac function and morphology using high-resolution positron emission tomography/computed tomography for small animals. Both mice and rats are considered, discussing the different requirements of computed tomography contrast agents for the two species.

小动物高分辨率心脏正电子发射断层扫描/计算机断层扫描

Positron emission tomography (PET) and computed tomography (CT) are among the most employed diagnostic imaging techniques, and both serve in understanding ...

通过高分辨率呼吸测定法测定人精子细胞中的呼吸

High-Resolution Respirometry to Assess Mitochondrial Function in Human Spermatozoa

Semen quality is often studied by routine semen analysis, which is descriptive and often inconclusive. Male infertility is associated with altered sperm mitochondrial activity, so the measurement of sperm mitochondrial function is an indicator of sperm quality. High-resolution respirometry is a method of measuring the oxygen consumption of cells or tissues in a closed-chamber system. This technique can be implemented to measure respiration in human sperm and provides information about the quality and integrity of the sperm mitochondria. High-resolution respirometry allows the cells to move freely, which is an a priori advantage in the case of sperm. This technique can be applied with intact or permeabilized spermatozoa and allows for the study of intact sperm mitochondrial function and the activity of individual respiratory chain complexes. The high-resolution oxygraph instrument uses sensors to measure the oxygen concentration coupled with sensitive software to calculate the oxygen consumption. The data are used to calculate respiratory indices based on the oxygen consumption ratios. Consequently, the indices are the proportions of two oxygen consumption rates and are internally normalized to the cell number or protein mass. The respiratory indices are an indicator of sperm mitochondrial function and dysfunction.

作者聚焦：通过揭示精子代谢和线粒体功能推进男性不育研究 

The analysis of sperm mitochondrial function by high-resolution respirometry permits the measurement of the oxygen consumption of freely moving spermatozoa in a closed-chamber system. The technique can be applied to measure respiration in human spermatozoa, which provides information on sperm mitochondrial characteristics and integrity.

高分辨率呼吸测定法评估人类精子的线粒体功能

Semen quality is often studied by routine semen analysis, which is descriptive and often inconclusive. Male infertility is associated with altered sperm ...