从血管集成生理学和实验治疗学（VIPERx）实验室，这项工作是由外科加州旧金山大学的系和北加州理工学院的研究与教育基金的支持。说明该项目是由国家研究资源中心支持奖号码KL2RR024130。内容完全是作者的责任，并不一定代表美国国家研究资源中心和美国国立卫生研究院的官方意见。

下面的过程，发达国家作为一个研究者发起的研究的一部分，审议并通过了由美国加州大学旧金山分校（UCSF）人类研究委员会（CHR）和所有参与者给予知情同意书。 1，设备<ol><li>使用心电图门控图像采集系统，记录并分析口蹄疫。飞利浦HD11超声连接到台式机。 </li><li>从与PC上的一个特殊的画面撷取卡超连接的视频信号。 </li><li>中继来自超声波的音频信号，放大所述信号的心电图门控模块。放大后的信号进行到PC，让图像捕捉软件，在心动周期一致点识别和记录图像。产生从R-波在EKG的急剧偏转的信号。 </li><li>使用5-12 MHz线阵探头在肱动脉的深度优化解决方案。 </li></ol> 2。除准备<ol><li>确保学员快速，避免锻炼在考试前8小时，以及避免咖啡因或尼古丁至少四四肢。确保参与者以免影响血管张力和心输出量四个半衰期药物。 注意:饮食，药物和一天中的时间可能会影响结果。 </li><li>进行考试在安静，黑暗的房间在21℃。当进行纵向研究，举办重复考试在一天的同一时间。 </li></ol> 3，基线测量<ol><li>让拍摄对象仰卧在考试表格。连接3导心电图在标准位置。解决任何骨科问题，以确保受试者将舒适和考试过程中从运动避免。 </li><li>让受考试开始前休息10分钟。后5分钟的休息，测量被检者的血压用振荡，非侵入性血压监视器。 <ol><li>应用5厘米在任一近侧或远侧位置urniquet袖口以证明上臂技术。 </li><li>延长受试者的手臂横向和心脏的水平维持。 </li><li>根据运营商的偏好时，使用表和枕头来约束主体的手臂。 </li><li>将操作者的手臂在抵抗疲劳，并且提供了在手腕支撑的位置处。尽量减少延长的手腕，并保持前臂在解剖中立位置。 </li></ol></li><li>进行肱动脉的横截面的扫描，开始在二头肌的插入和跟进近侧。使用彩色血流成像，以验证在肱动脉和定位，可作为标志性建筑的侧支血管。 </li><li>当一个合适的位置被找到时，旋转探头90°，以使邻近边缘上的超声波屏幕的左侧显示。维持使用大量的实践和细腻的触感动脉的位置。 Verify中的取向通过推动组织附近的远端边缘。标记被检者的皮肤沿所述探针的远端边缘。 </li><li>对准探针与深或聚焦设置"远"壁肱动脉，以改善图像的横向分辨率。不同与更高的频率提高轴向分辨率的轴向分辨率探头设置。 </li><li>调整探头的角度，以优化的两个近和远壁对比度分辨率。小的变化的角度可导致改进的对比度。估计用一个简单的量角器的角度，如果串行考试是关于这一主题进行。 </li><li>为了确保质量的测量，确保容器是水平的，并与纵向轴线对准。使压力的微小变化（倾侧探头的一端），以帮助使动脉。总体而言，保压光，以帮助防止操作者的疲劳。 </li><li>当进行了优化，保证了"Pignoli的双行"中可以看到íÑ​​墙壁，对应内膜中层厚度。使用增益调整，以减少回波在血管腔。允许至少2cm内膜中介厚度（IMT）两侧为精确直径测量。 </li></ol> 4，基线测量<ol><li>记录使用二维多普勒模式下，基准速度。放置样品门在管腔的中央，保持60°的声波作用角。收集60秒的数据。 </li></ol> 5，闭塞相<ol><li>袖带充气至50毫米汞柱的受试者的收缩压以上。使用5厘米止血带袖带会高估收缩压。使用二维多普勒模式来验证闭塞。 </li><li>使用定时器来跟踪遮挡的时间尽可能多的血压计会慢慢失去压力超过5分钟。使用二维多普勒模式，以验证完全闭塞。 </li><li>闭塞4时30分后，将二维多普勒门稍浅的纵动脉的轴。调整垂直刻度占2-3倍的速度比基准高。 </li><li>调整在图像捕获软件的设置记录的3:10。 </li><li>开始记录袖带释放之前10秒捕捉到袖带释放，测量时间时，在数据分析期间达到峰值直径的一个重要参数的时间。 </li></ol> 6充血<ol><li>松开袖带。由于动脉袖带可释放后表面移动，进行小改动探头的位置，一边听着扩增的声音，以帮助弥补的转变。重新定位的多普勒取样门和声波作用的角度，如果动脉的变化。 </li><li> 30秒的速度记录后，切换超声B模式。 </li><li>由于它是常见的探头考试过程中近侧滑动，使用容器的标志或标记的受试者的皮肤来验证探头位置。考试这个阶段是获得准确的关键结果。 </li><li>调整探针的位置或角度，以优化IMT两壁上进行小的变化可以显着改善图象。记录的直径为3分钟。 </li><li>如果重复测量计划，利用拍摄对象的皮肤标记来记录距离肘窝。让拍摄对象弯曲的手臂90°，标志着折痕。从该行早前提出的行措施。 </li></ol>

作者什么都没有透露。

内皮功能障碍是影响血管张力和在动脉粥样硬化的发展中的早期步骤中的化学介质的不平衡。测定动脉的反应性的方法，以评估这些化学途径的状态。评估反应的直接和间接方法的不同血管床的存在，从直接输注的内皮激动剂在冠状循环中的食指38的非侵入性，脉冲波形的分析。 肱动脉FMD是一个已建立的技术用于通过高频超声波间接地评价血管内皮功能。有优势，在?...

人类血管内皮细胞提供了在体内的结构和功能的作用。在组织切片中，内皮细胞出现小的，包括薄层细胞1-2微米厚坐​​在上面一层平滑肌细胞（媒体）和一个厚厚的一层结缔组织（外膜）的。作为一个整体，内皮细胞提供了一个广泛区域的血液和血管的平滑肌组织之间的信息交流。据估计，700 平方米和横截面面积的质量为1000-1500克体重70公斤的人，相当于在群众肝脏1。一个健康的内皮细胞可用于机械化学信号传导，保持血管的内环境稳定。内皮功能障碍是这些介质失衡，血管疾病的第一步，本前动脉粥样硬化的组织学证据。一种非侵入性的， 在活体内的方法用于定量人体的血管舒张作用动脉存在。该方法中，内皮依赖性，血流介导的血管舒张（FMD）是广泛用于临床试验。 内皮细胞充当血管的结构组分和生产的胞外基质组分，例如葡糖胺聚糖和纤连蛋白2。在血流和急性损伤动脉长期变化可能导致结构的改变。在功能上，血管内皮细胞参与血管张力，炎性过程，抗血栓形成和抗凝血的调节。内皮细胞的影响血管收缩，通过内皮素而血管舒张是由一氧化氮（NO），前列环素和内皮超极化因子（EDHF）3-6介导的。 内皮功能障碍是任何这些介质和动脉粥样硬化的第一步减值。这并不奇怪，因为疾病的一种机制，它与一些重要的临床相关条件，例如冠状动脉疾病，高血压和糖尿病7-11。重要的是，内皮功能障碍可以在个人未经诊断的心血管疾病进行观察，并预测未来的心血管事件7,12,13的。内皮功能障碍的一项措施，与Framingham评分相结合，可以提供单独或者14以上的措施更多的预后信息。 血管内皮功能障碍的措施可能涉及直接输注药物剂。 Intercoronary输注乙酰胆碱，例如，结合的定量血管造影术证明的受试者具有完整内皮的血管舒张。然而，随着血管内皮损伤的经验似是而非的血管收缩个人。15外周动脉，输液用计，应变容积描记药理剂流量的测量是可能的16。 代理Š直接影响内皮和引发一种化学信号，被称为内皮依赖性的血管扩张剂。乙酰胆碱，例如，作用于毒蕈碱性受体在内皮细胞上，从而增加细胞内钙浓度，活化一氧化氮合酶和血管舒张。影响血管舒张无内皮细胞的参与剂被称为内皮依赖性药物。硝酸甘油，例如，激活可溶性鸟苷酸环化酶和环鸟苷-3&#39;， - 5&#39;-monophasphate（cGMP）的其中通过蛋白激酶介导的血管扩张，在血管壁调节细胞内钙浓度的17。 有一种非侵入性的， 在体内方法用于定量由Celermajer和同事引入血管内皮功能障碍称为"血流介导的内皮依赖性血管舒张"（FMD）18。简单地说，改变动脉血流开放的剪切力敏感的离子赞NELS在内皮。该信号通过第二信使级联tranduced并激活内皮型一氧化氮合酶（eNOS），生成NO。穿过细胞膜此物种扩散到邻近的平滑肌细胞（SMC）。内的SMC，信号转导，从而降低细胞内钙离子浓度，影响血管舒张19。动脉管腔的直径增大，从而增加血流量用的哈根 - Poiseullie方程一致。口蹄疫的效果，可以取消与NO合成酶抑制剂，如单甲基精氨酸（L-NMMA）20的施用。 Celermajer 等人的创新工作已经允许使用高分辨率B型超声后面缺血的反应性充血过程中，以评估在动脉直径的变化。在该技术中，人受试者休息仰卧和肱动脉的直径，测量在纵向平面上。 A型血，pressu再压脉袋是用来产生缺血肢体。以下的血压袖带动脉的直径，再次测量的释放。在剪应力的急剧变化是刺激NO介导的血管扩张。一个简单的公式说明了相对于基线直径（ 式1）的直径的改变。这个方程，充血和基线直径的参数的全面讨论，可以在协议中找到和结果部分。 在多个研究中，百分之口蹄疫已发现预测患者的心血管事件既定的心血管疾病21-24。肱动脉FMD百分比和冠状动脉之间的相关性口蹄疫，建立了安德森等人 ，魔trating外围测量和更多的临床相关的缺血性变化之间的联系到心脏25。口蹄疫并不表明容器的最大血管舒张。为了评估此，口蹄疫可以跟随内皮依赖性，硝酸甘油介导的同一容器中的血管舒张。 有百分之影响口蹄疫的测量技术问题。自从引进该技术，一些研究显示，内学科，跨运营商的变化26度很高。它已经表明，生理因素如吸烟，抗高血压药物，一天中的时间，和空腹状态影响百分之口蹄疫。同样，技术的选择，如相对于测量和闭塞的持续时间的现场箍的位置已被证明影响测量27,28。指南已经出版，描述目前的共识，并允许技术与标准化实验室19,29。 尽管在技术不断发展的共识，血流介导的血管扩张仍严重依赖于操作者用长的学习曲线。 Corretti，例如，推荐一个经验丰富的调查员的监督下，超声医师完成100次独立运作之前。为了保持足够的专业知识水平，每年推荐的技师完成100次。对于研究人员用小样本的人口和有限的资源，学习曲线提供了一个进入门槛。本文将说明在上臂肱动脉血流介导的血管舒张的方法，并提供技术建议，以减少操作符内部的可变性。

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:71px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Philips HD 11XE ultrasound</td>
			<td style="width:71px;">Philips Healthcare</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">5-12 MHz linear array transducer</td>
			<td style="width:71px;">Philips Healthcare</td>
			<td style="width:119px;">L12-5</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">Ultrasound gel</td>
			<td style="width:71px;">Parker Laboratories</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">Vascular Research Tools v.5.0</td>
			<td style="width:71px;">Medical Imaging Applications, LLC</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="84">
			<td height="84" style="height:84px;width:216px;">MIA Gating module</td>
			<td style="width:71px;">Medical Imaging Applications, LLC</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Desktop PC</td>
			<td style="width:71px;">Dell, Inc</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Windows XP</td>
			<td style="width:71px;">Microsoft, Inc</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">5 cm tourniquet blood pressure cuff</td>
			<td style="width:71px;">Hokanson</td>
			<td style="width:119px;">SC 5</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Hand-held aneroid manometer</td>
			<td style="width:71px;">Welch Allyn</td>
			<td style="width:119px;">DS66</td>
			<td></td>
		</tr>
	</tbody>
</table>

ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery in clinical research

血管内皮细胞是细胞覆盖血管的内部，并提供其结构和功能的作用的单层。内皮细胞充当一个屏障，阻止白细胞粘附和聚集，以及控制渗透性血浆成分。在功能上，影响内皮血管张力。 内皮功能障碍是一种调节血管张力，thombroresistance，细胞增殖和有丝分裂的化学物质之间的不平衡。它是在动脉粥样硬化的第一步骤，并且有冠状动脉疾病，外周动脉疾病，心脏衰竭，高血压和高脂血症相关联。 血管内皮功能障碍的第一个示范涉及直接输注乙酰胆碱和定量冠状动脉造影。乙酰胆碱结合的毒蕈碱受体在血管内皮细胞表面，从而增加细胞内钙而增加镍TRIC氧化氮（NO）的产生。在受试者一个完整的内皮细胞，血管扩张，观察，同时患有血管内皮损伤经历了矛盾的血管收缩。 存在着一种非侵入性的体内测定方法内皮功能使用高分辨率的B模式超声外周动脉。外周动脉的内皮功能密切相关，冠状动脉功能。这种技术在测量肢体缺血的时间反应性充血肱动脉直径百分比变化。 这种技术被称为内皮依赖性，血流介导的血管舒张（FMD）具有在临床研究的设置值。然而，一些生理和技术问题可能影响结果和相应的准则，该技术的准确度已经公布。尽管指引，口蹄疫仍然严重依赖于操作者，并提出一个陡峭的学习曲线。本文介绍了一种标准化的方法，上臂测量口蹄疫的肱动脉，并提供建议，以降低运营商内部的变化。

血流介导的血管舒张的关键变量示于表1中 。 <table border="0" cellpadding="0" cellspacing="0" fo:keep-together.within-page="always"><tbody><tr><td>变量</td><td>说明</td></tr><tr><td>平均血流速度（厘米/秒） </td><td>血的平均动脉速度在管腔的中间50％的期间，从多普勒频谱波形，正比于血流量和反比于截面积推定一心跳周期（参见图1）。 </td></tr><tr><td>直径（mm） </td><td>如从沿着容器轴线的纵向?...

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Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research

内皮功能障碍与许多疾病有关，并预测在人类心血管不良事件。血流介导的舒张功能（FMD）是评价血管内皮功能的超声无创方法。方法的选择和操作者的经验可能会影响结果。在人类研究中的系统方法口蹄疫是在这里讨论。

肱动脉的临床研究超声评价血管内皮依赖性血流介导的血管舒张功能

The vascular endothelium is a monolayer of cells that cover the interior of blood vessels and provide both structural and functional roles. The ...

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27.2K 次观看.  University of California, San Francisco. 内皮功能障碍与许多疾病有关，并预测在人类心血管不良事件。血流介导的舒张功能（FMD）是评价血管内皮功能的超声无创方法。方法的选择和操作者的经验可能会影响结果。在人类研究中的系统方法口蹄疫是在这里讨论。 

视频: Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research

The Use of Pharmacological-challenge fMRI in Pre-clinical Research: Application to the 5-HT System

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel underlying neurobiological mechanisms behind drug action and neurotransmitter-related disorders, such as depression and ADHD. Like most of the imaging methods (PET, SPECT, CT) it represents a progress in the investigation of brain disorders and the related function of neurotransmitter pathways in a non-invasive way with respect of the overall neuronal connectivity. Moreover it also provides the ideal tool for translation to clinical investigations. MRI, while still behind in molecular imaging strategies compared to PET and SPECT, has the great advantage to have a high spatial resolution and no need for the injection of a contrast-agent or radio-labeled molecules, thereby avoiding the repetitive exposure to ionizing radiations. Functional MRI (fMRI) is extensively used in research and clinical setting, where it is generally combined with a psycho-motor task. phMRI is an adaptation of fMRI enabling the investigation of a specific neurotransmitter system, such as serotonin (5-HT), under physiological or pathological conditions following activation via administration of a specific challenging drug.
The aim of the method described here is to assess brain 5-HT function in free-breathing animals. By challenging the 5-HT system while simultaneously acquiring functional MR images over time, the response of the brain to this challenge can be visualized. Several studies in animals have already demonstrated that drug-induced increases in extracellular levels of e.g. 5-HT (releasing agents, selective re-uptake blockers, etc) evoke region-specific changes in blood oxygenation level dependent (BOLD) MRI signals (signal due to a change of the oxygenated/deoxygenated hemoglobin levels occurring during brain activation through an increase of the blood supply to supply the oxygen and glucose to the demanding neurons) providing an index of neurotransmitter function. It has also been shown that these effects can be reversed by treatments that decrease 5-HT availability16,13,18,7. In adult rats, BOLD signal changes following acute SSRI administration have been described in several 5-HT related brain regions, i.e. cortical areas, hippocampus, hypothalamus and thalamus9,16,15. Stimulation of the 5-HT system and its response to this challenge can be thus used as a measure of its function in both animals and humans2,11.

The goal of this technique is to assess serotonin (5-HT) neurotransmitter function in the live and free-breathing animal with pharmacological magnetic resonance imaging (phMRI) and an intravenous challenge with a selective serotonin reuptake inhibitor (SSRI), fluoxetine.

挑战的药理功能磁共振成像:在临床前研究使用的5  - 羟色胺系统中的应用

Pharmacological MRI (phMRI) is a new and promising method to study the effects of substances on brain function that can ultimately be used to unravel ...

科研

医学

A Novel Application of Musculoskeletal Ultrasound Imaging

Ultrasound is an attractive modality for imaging muscle and tendon motion during dynamic tasks and can provide a complementary methodological approach for biomechanical studies in a clinical or laboratory setting. Towards this goal, methods for quantification of muscle kinematics from ultrasound imagery are being developed based on image processing. The temporal resolution of these methods is typically not sufficient for highly dynamic tasks, such as drop-landing. We propose a new approach that utilizes a Doppler method for quantifying muscle kinematics. We have developed a novel vector tissue Doppler imaging (vTDI) technique that can be used to measure musculoskeletal contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities using ultrasound. The goal of this preliminary study was to investigate the repeatability and potential applicability of the vTDI technique in measuring musculoskeletal velocities during a drop-landing task, in healthy subjects. The vTDI measurements can be performed concurrently with other biomechanical techniques, such as 3D motion capture for joint kinematics and kinetics, electromyography for timing of muscle activation and force plates for ground reaction force. Integration of these complementary techniques could lead to a better understanding of dynamic muscle function and dysfunction underlying the pathogenesis and pathophysiology of musculoskeletal disorders.

We describe a new ultrasound-based vector tissue Doppler imaging technique to measure muscle contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities. This approach provides complementary measurements of dynamic muscle function and could lead to a better understanding of mechanisms underlying musculoskeletal disorders.

肌肉骨骼超声成像的一种新应用

Ultrasound is an attractive modality for imaging muscle and tendon  motion during dynamic tasks and can provide a complementary methodological  approach ...

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

时空步态参数的患者和老年人的临床评估

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

Ultrasound Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow reserve (CFR) in humans. Reduced CFR is accompanied by marked intramyocardial and pericoronary fibrosis and is used as an indication of the severity of dysfunction. This study explores, step-by-step, the real-time changes measured in the coronary flow velocity, CFR and systolic to diastolic peak velocity (S/D) ratio in the setting of an aortic banding model in mice. By using a Doppler transthoracic imaging technique that yields reproducible and reliable data, the method assesses changes in flow in the septal coronary artery (SCA), for a period of over two weeks in mice, that previously either underwent aortic banding or thoracotomy. 
During imaging, hyperemia in all mice was induced by isoflurane, an anesthetic that increased coronary flow velocity when compared with resting flow. All images were acquired by a single imager. Two ratios, (1) CFR, the ratio between hyperemic and baseline flow velocities, and (2) systolic (S) to diastolic (D) flow were determined, using a proprietary software and by two independent observers. Importantly, the observed changes in coronary flow preceded LV dysfunction as evidenced by normal LV mass and fractional shortening (FS). 
The method was benchmarked against the current gold standard of coronary assessment, histopathology. The latter technique showed clear pathologic changes in the coronary artery in the form of peri-coronary fibrosis that correlated to the flow changes as assessed by echocardiography. 
The study underscores the value of using a non-invasive technique to monitor coronary circulation in mouse hearts. The method minimizes redundant use of research animals and demonstrates that advanced ultrasound-based indices, such as CFR and S/D ratios, can serve as viable diagnostic tools in a variety of investigational protocols including drug studies and the study of genetically modified strains.

Coronary flow reserve (CFR) is useful for assessment of myocardial oxygen demand and evaluation of cardiovascular risk. This study establishes a step-by-step transthoracic Doppler echocardiographic (TTDE) method for longitudinal monitoring of the changes in CFR, as measured from coronary artery in mice, under the experimental pressure overload of aortic banding.

冠脉流量和冠状动脉血流储备用小鼠压力超负荷基于模型的超声评估

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow ...

Ultrasound Assessment of Endothelial Function: A Technical Guideline of the Flow-mediated Dilation Test

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a pathological condition characterized mainly by a disruption in the balance between vasodilator and vasoconstrictor substances and is proposed to play an important role in the development of atherosclerotic cardiovascular disease. Therefore, a precise evaluation of endothelial function in humans represents an important tool that could help better understand the etiology of multiple cardio-centric pathologies.
Over the past twenty-five years, many methodological approaches have been developed to provide an assessment of endothelial function in humans. Introduced in 1989, the FMD test incorporates a forearm occlusion and subsequent reactive hyperemia that promotes nitric oxide production and vasodilation of the brachial artery. The FMD test is now the most widely utilized, non-invasive, ultrasonic assessment of endothelial function in humans and has been associated with future cardiovascular events.
Although the FMD test could have clinical utility, it is a physiological assessment that has inherited several confounding factors that need to be considered. This article describes a standardized protocol for determining FMD including the recommended methodology to help minimize the physiological and technical issues and improve the precision and reproducibility of the assessment.

The flow mediated dilation (FMD) test is the most commonly utilized, non-invasive, ultrasound assessment of endothelial function in humans. Although the FMD test has been related with the prediction of future cardiovascular disease and events, it is a physiological assessment with many inherent confounding factors that need to be considered.

血管内皮功能的超声评估:血流介导的舒张试验的技术指导原则

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a ...

Ultrasound-based Pulse Wave Velocity Evaluation in Mice

Arterial stiffness can be evaluated by calculating pulse wave velocity (PWV), i.e., the speed with which the pulse wave travels in a conduit vessel. This parameter is being increasingly investigated in small rodent models in which it is used for assessing alterations in vascular function related to particular genotypes/treatments or for characterizing cardiovascular disease progression. This protocol describes an image processing algorithm which leads to non-invasive arterial PWV measurement in mice using ultrasound (US) images only. The proposed technique has been used to assess abdominal aorta PWV in mice and evaluate its age-associated changes.
Abdominal aorta US scans are obtained from mice under gaseous anesthesia using a specific US device equipped with high-frequency US probes. B-mode and Pulse-Wave Doppler (PW-Doppler) images are analyzed in order to obtain diameter and mean velocity instantaneous values, respectively. For this purpose, edge detection and contour tracking techniques are employed. The single-beat mean diameter and velocity waveforms are time aligned and combined in order to achieve the diameter-velocity (lnD-V) loop. PWV values are obtained from the slope of the linear part of the loop, which corresponds to the early systolic phase.
With the present approach, anatomical and functional information about the mouse abdominal aorta can be non-invasively achieved. Requiring the processing of US images only, it may represent a useful tool for the non-invasive characterization of different arterial sites in the mouse in terms of elastic properties. The application of the present technique can be easily extended to other vascular districts, such as the carotid artery, thus providing the possibility to obtain a multi-site arterial stiffness assessment.

Arterial stiffness represents a key factor in cardiovascular disease and pulse wave velocity (PWV) can be considered as a surrogate index for arterial stiffness. This protocol describes an image processing algorithm for calculating PWV in mice based on ultrasound image processing that is applicable at different arterial sites.

基于超声脉搏波速度评价小鼠

Arterial stiffness can be evaluated by calculating pulse wave velocity (PWV), i.e., the speed with which the pulse wave travels in a conduit vessel. This ...

Ultrasound Assessment of Flow-Mediated Dilation of the Brachial and Superficial Femoral Arteries in Rats

Arterial vasodilation to increases in wall shear rate is indicative of vascular endothelial function. In humans, the non-invasive measurement of endothelial function can be achieved by employing the flow-mediated dilation technique, typically performed in the brachial or superficial femoral artery. Briefly, a blood pressure cuff placed distal to an ultrasound probe is inflated to a suprasystolic pressure, which results in limb ischemia. After 5 min of occlusion the cuff is deflated, resulting in reactive hyperemia and increases in wall shear rate that signal vasodilatory molecules to be released from the endothelium eliciting vasodilation. Despite the thousands of studies performing flow-mediated dilation in humans, surprisingly, no studies have performed this technique non-invasively in living rats. Considering the recent shift in focus to translational research, the establishment of guidelines for non-invasive measurement of flow-mediated dilation in rats and other rodents would be extremely valuable. In the following article, a protocol is presented for the non-invasive measurement of flow-mediated dilation in brachial and superficial femoral arteries of rats, as those sites are most commonly measured in humans.

Non-invasive assessment of endothelial function in humans can be determined by the flow-mediated dilation technique. Although thousands of studies have used this technique, no study has performed this technique non-invasively in rats. The following article describes non-invasive measurement of flow-mediated dilation in the brachial and superficial femoral arteries of rats.

肱血流介导的扩张和大鼠股浅动脉超声评估

Arterial vasodilation to increases in wall shear rate is indicative of vascular endothelial function. In humans, the non-invasive measurement of ...

Brachial Artery Catheterization in Swine

The video describes in detail the catheterization of the distal brachial artery in swine. This technique enables researchers to measure arterial blood pressure continuously and collect arterial blood samples to assess arterial blood gas measurements. Arterial blood pressures and arterial blood gases are important physiological parameters to monitor during experimental procedures. In swine, four common methods of arterial catheterization have been described, including catheterization of the carotid, femoral, auricular, and medial saphenous arteries. Each of these techniques have advantages, such as ease of access for the auricular artery, and disadvantages that include deep tissue dissection for carotid artery catheterization. The described alternative method of arterial catheterization in swine, the catheterization of the distal aspect of the brachial artery, is a rapid procedure that requires relatively minimal tissue dissection and provides information that is in line with data collected from other arterial catheterization sites. The procedure uses a medial approach along an oblique plane of the lower brachium, positioned between the olecranon and the flexor aspect of the elbow joint, and this approach allows researchers the major advantage of unimpeded freedom for procedures that involve the caudoventral, caudodorsal back, or hind limbs of the pig. Due to the location of the upper forelimb of the catheterized vessel and potential challenges of effective homeostasis following catheter removal from the artery, this technique may be limited to non-recovery procedures.

The video describes in detail the catheterization of the distal brachial artery in swine. This procedure accurately measures arterial blood pressure and is a simple and fast method to collect samples for arterial blood gas measurements.

猪的臂动脉插管

The video describes in detail the catheterization of the distal brachial artery in swine. This technique enables researchers to measure arterial blood ...

Assessment of Static Graviceptive Perception in the Roll-Plane using the Subjective Visual Vertical Paradigm

Vestibular disorders are among the most common syndromes in medicine. In recent years, new vestibular diagnostic systems have been introduced that allow the examination of all semicircular canals in the clinical setting. Assessment methods of the otolithic system, which is responsible for the perception of linear acceleration and perception of gravity, are far less in clinical use. There are several experimental approaches for measuring the perception of gravity. The most frequently used method is the determination of the subjective visual vertical. This is usually measured with the head in an upright position. We present here an assessment method for testing otolith function in the roll plane. The subjective visual vertical is measured in the head upright position as well as with head inclination of &#177; 15&#176; and &#177; 30&#176; in the roll plane. This extended functional paradigm is an easy-to-perform clinical test of otolith function and ensures increased information content for the detection of impaired graviceptive perception.

The perception of gravity is commonly determined by the subjective visual vertical in the head upright position. The additional assessment at head tilts of &#177; 15&#176; and &#177; 30&#176; in the roll plane ensures increased information content for the detection of impaired graviceptive perception.

使用主观视觉垂直范式对卷平面中的静态视觉感知的评估

Vestibular disorders are among the most common syndromes in medicine. In recent years, new vestibular diagnostic systems have been introduced that allow ...

Direct Drug Delivery to Kidney via the Renal Artery

There is a need for directed injections to enable increased and specific renal exposure for efficient evaluation of drug targets in the renal research field. Accumulation of drugs in certain organs may give rise to adverse and unwanted effects, depending on the nature of injectate. To minimize spillover and/or accumulation in other tissues, the herein described method directs the formulation into the renal artery bloodstream by inserting a catheter in the infra renal aorta, just below where it branches into the renal artery, resulting in the kidney as first reached organ and distributing of formulation throughout the kidney.
This manuscript provides a detailed description of the method, as well as its challenges and difficulties. It guides the experimenter to become skillful with this type of microsurgery that requires accuracy under sterile conditions. Speed is crucial for minimizing the ischemia and practicing the procedure will increase the chance of successful injections without adverse effects. By modulating the time between injection and reperfusion as well as the injected volume, the risk of spillover to other organs is mitigated. 
Note that this technique is suitable for single dosing strategies.

This manuscript describes a method for targeted delivery to a single kidney via a catheter placed in the infrarenal abdominal aorta in the mouse.

通过肾脏动脉直接向肾脏输送药物

There is a need for directed injections to enable increased and specific renal exposure for efficient evaluation of drug targets in the renal research ...