我们要感谢教授罗杰的海恩斯沃思，谁开发这种技术。我们感谢他们的协助与摄影王杭超先生和胡王先生乔。 这项工作是由西蒙·弗雷泽大学和加拿大心脏及中风基金会的支持。

在整个测试中，连续拍来拍血压和心电图（ECG）监测是至关重要的。这确保受试者的安全，并及时终止测试与晕厥发作。节拍可以通过动脉插管，或手指体积描记法31-33击败血压记录。后者用于在该协议中，因为它是非侵入性的，可以评估的发生晕厥与留置31,34相同的精度，没有侵入性的监测OT 1的不利影响。使用的Modelflow技术的每搏输出量的变化，心输出量和总外周阻力可以来自手指的动脉压波形35,36。还可以进行额外的非侵入性的措施，可能有助于血流动力学的评价，并且将在这里描述。的连续呼气末氧（P ET O 2）和二氧化碳（P ET CO 2的 </sUB）使用鼻导管监测，可以评估的任何贡献，过度换气主体的症状。最后，可以进行多普勒超声监测肱动脉和脑血流速度的外围设备和脑血管反应orthostasis的允许的决心。此外，测量静脉池和毛细血管滤过的也可以用阻抗体积描记法20。最终，该协议允许的姿势的心血管反射控制在可控和可重复的设置进行评估。 1。设备<ol><li>手动可调的倾斜表是能够从-15至60℃，在10°的增量（ 图1）移动。它包括一个可调节的支架为臂丛超声探头（ 图1D），可调节的踏板为主题，站在一个可调节的右手臂休息，安全带，以确保拍摄对象的乐GS（ 图1E）。 </li><li>与一个附加的压力表的下体负压腔室适合在一个木制的槽填充有氯丁橡胶上的下半部分的倾斜表和由四个可调的带（ 图1）被固定在适当位置。一个透明的有机玻璃材料，可用于室，如果需要的话，受试者的腿，使可视化，从而任何骨骼肌抽水活动的可视化监控。 </li><li>木造腰部板被连接到腔室的顶部配备聚氯丁橡胶，环绕在被检者的髂骨水平提供一种气密的密封件与腔室（ 图1B）。髂嵴水平的选择，因为它避免了应用程序的LBNP的腹部，这可能是不舒服，但确保了标准化的刺激不同身高的个人。 </li><li>执行连续的节拍来拍1 KHz的使用模拟 - 数字转换器的采样频率的数据采集。可视化所有DATA同时在真正的时间整个测试使用LabChart（PowerLab系统16/30，AD仪器，科罗拉多斯普林斯，CO）。 </li><li>进行测试中的温度控制室温（20-22°C），以避免已知的热应激时OT 37。测试的理想是在早晨进行，因为对压力感受性反射控制昼夜节律的影响38。在某些情况下，一个熟悉会话应的程序的"应激反应"的影响减到最小。 </li><li>指导的主题只有一个清淡的早餐，以尽量减少可能的混杂因素，由于餐后低血压，在上午的测试，以避免咖啡因和剧烈运动。主题应禁食2小时前测试。他们也应该放弃饮用酒精测试前24小时，以消除酒精的利尿作用和随之而来的血浆量减少，这是众所周知的减少OT 39。 </li><li> 图2给出了协议。在桌子上的脚踏板和支架的主题，将它们移动到一个仰卧位（ 图1）。仰卧，调整髂嵴中心的表。这使得易于倾斜，和确保标准化的下体负压室定位。调整踏板。脚踏板的支持是最好的，因为表鞍支持与增加假阳性反应，这可能是由于过度压缩的腿和盆腔静脉。 </li><li>卢斯利定位表带的正上方膝，促进被动的地位和姿势的支持。指导受试者在测试过程中，不把他们的腿。主体的右臂上的扶手，调整舒适的支撑，它是在心脏水平位置。安装监控设备。 </li><li>开展击败到拍血压监测使用Finometer，根据制造商的说明40。选择指套符合适当Ø置身于主体的右手中指中节指骨。使用上臂袖带内部校准Finometer数据采集前。输入对象的性别，年龄，身高和体重，到Finometer，使适当的假设的Modelflow算法35,36。 </li><li>准确测定心脏率的反应是很重要的，持续心电监护，并能迅速识别，一旦发生任何心律失常。应用心电图电极的变形的铅II配置，，确保电极站点不干扰定位的氯丁橡胶腰部板。 </li><li>确定周边用多普勒超声在心脏水平（以免影响静水压力的变化对血压和速度的手臂）支持的右臂的肱动脉血管反应。触诊动脉，直至位于脉冲。应用超声凝胶面积和位置的8 MHz的超声探头，brachi人动脉速度波形被获得（ 图3A，B）。 </li><li>一旦信号被识别时，优化的深度和增益，并拧紧的可调夹持器保持测试的持续时间（ 图3B）的角度的声学效应常数。这是很重要的，因为，所述的多普勒频移方程，速度的变化将是在流动的变化成比例，如果角度是恒定的声学效应和动脉直径19,21。 </li><li>确定同样的脑血管反应性（ 图4A，B）。固定在脑的超声波探头（2兆赫）代替使用的塑料耳机或织物头带（ 图4B），以确保整个测试的忠实的 ​​信号检测和恒定的角度的声学效应。 </li><li>确定不断从大脑中动脉血流速度。容器的选择，因为其方便的识别，全脑灌注的巨大贡献，和const蚂蚁直径在立位应激41，确保速度的变化成正比，流量变化。应用超声凝胶主体的寺庙和定位的容器（ 图4A）。一旦确定，优化的深度和增益设置。 </li><li>将鼻导管。鼻采样是优选的，因为它允许在测试期间（不像使用吹嘴），可自由的主题。这是很重要的，启用自我报告症状的认可，同时避免了侵入性血液采样，可能会产生不利影响OT。然而，在演讲中，或当拍摄对象，通过他们的嘴呼吸，这些读数的准确性可能受到影响。鼓励科目通过自己的鼻子呼吸。 </li><li>放置在桌子上，LBNP室的肩带固定。选择一个腰部板紧贴，使得可以实现与氯丁橡胶的气密密封（ 图1B）。木制构件的腰部板不应该是touc兴的主题。腰部固定板腔。连接腔室的负压源， 通过一个可变电阻器（ 图1C）。 </li></ol> 2。数据采集<ol><li>记录20分钟的仰卧位的数据。较短的休息时间与血压下降，直立时，大概是因为已收集的任何流体的依赖四肢躺着的重吸收是尚未完成20。 </li><li>结束时的仰卧阶段操纵表，以60°的倾斜角。该角度是优选的，因为它可以提供近90％的最大垂直位移，同时允许受保持放松和支持对倾斜表（泵送活动具有较高的倾斜角的骨骼肌的混杂影响最小化）。减陡峭的角度，可能会增加假阴性率，虽然倾斜角的生理效应≥60°，较高的倾斜角与在特异性6减少。 </li><li>完成过渡到直立三十秒内。过渡时间不知道的影响的OT，它是愉快的问题，如果倾斜是不是过快。然而，非常缓慢的倾斜演习可能会与激活肌肉交感神经活性降低，应避免42。 </li><li>连续监控对象的心血管参数以及他们的主观经验。试验应立即停止，并返回到拍摄对象的仰卧位置，如果满足任何下面的结束点的标准:血压为80毫米汞柱或以下;心脏速率是低于50，每分钟节拍数（bpm）或更高超过170 BPM的主体经验的症状，如头晕，发热，并要求停止或协议完成。 </li><li>除非有一个具体的启动晕厥的愿望，迅速终止测试在晕厥前症状和体征，避免坦诚晕厥的发作。 </li><li> 20分钟后，倾动申请下体负压，同时仍然倾斜，为进一步的10分钟，在-20毫米汞柱。重要的是要告知下体负压即将发病的主题，以防止惊吓反应的感觉和声音的LBNP。 </li><li> 10分钟后，增加LBNP另一个10分钟-40毫米汞柱。 </li><li> 10分钟后，增加LBNP到-60毫米汞柱，并继续另外10分钟。在这个阶段结束时，关闭LBNP，并返回到仰卧姿势。 </li><li>这在理论上是可能的增加实现-80毫米汞柱LBNP如果晕厥前终点还没有达到在此阶段结束时的真空源。然而，在实践中，这种高层次的LBNP是不舒服的问题，的晕厥通常发生在立位应激水平要低得多，即使是在健康对照组。最大的OT录得50分钟（-60毫米汞柱），这是在秘鲁HIG与慢性高原病和极高血量的43的 Ĥ海拔居民。 </li><li> OT晕厥时间（分钟）被定义为从一开始的头的倾斜相。 </li><li>为了确保迅速终止晕厥的症状和体征的，所以要尽量减少晕厥或心搏停止的可能性，迅速恢复仰卧位是理想的（理想情况下〜1秒）。出于这个原因，一个手动倾斜表可能是优选的植物神经一个，它可能不具有这种快速转换的能力。返回的表稍微头向下的位置（-15℃），可促进更快地解决晕厥前事件。一旦所有变量返回到仰卧水平和解决任何症状，删除监控设备。 </li><li>除去下体负压室后，对被检者的腿和删除表带降低到其原始位置的脚踏板。确定主题定位板用自己的脚。 </li><li>在返回表直立的位置，指示紧张的腿部肌肉在整个过渡时期，以避免任何症状表的再度发生倾斜，以便他们下车44,45。询问的主题坐下后走下表，以确保他们在离开实验室之前，是没有症状的。 </li></ol>

没有利益冲突的声明。

这种技术是重现性好，有能力区分正常和异常反应具有很高的灵敏度和特异性，可以引起晕厥在所有科目，让患者反复发作晕厥的症状的识别。在临床上，可以区分，不同类型的晕厥，进行针对性的治疗和管理方法。可以很容易地评估干预措施的影响。额外的心血管监测，反射性的反应也可以进行评估。 为了区分某些类型的晕厥患者人群，立位应激时血浆儿茶酚胺的反应分?...

<table border="1"><tbody><tr><td> 设备 </td><td> 生产厂家 </td><td> 位置 </td></tr><tr><td>倾斜表</td><td>自定义构建</td><td>英国利兹</td></tr><tr><td> Finometer </td><td> Finapres医疗系统</td><td>阿姆斯特丹，荷兰</td></tr><tr><td>多普勒盒</td><td> Compumedics </td><td>德国Singen </td></tr><tr><td>多普勒软件</td><td> DWL多普勒公司</td><td>德国Singen </td></tr><tr><td>使用Aquasonic超声凝胶</td><td>帕克Laboratories公司</td><td>美国费尔菲尔德， </td></tr><tr><td>头带</td><td> Lululemon公司</td><td>加拿大伯纳比， </td></tr><tr><td>耳机</td><td>加拿大轮胎</td><td>加拿大伯纳比， </td></tr><tr><td>心电图</td><td> Finapres心电图模块，Finapres中号兼具医疗系统</td><td>阿姆斯特丹，荷兰</td></tr><tr><td>电极</td><td>红点</td><td>安大略，加拿大的</td></tr><tr><td>防腐异丙基酒精棉片</td><td> Lernapharm </td><td>加拿大魁北克省， </td></tr><tr><td> O 2帽氧气分析仪</td><td> Oxigraph公司</td><td>美国加利福尼亚州</td></tr><tr><td> Airlife鼻氧管</td><td>卡地纳健康</td><td>美国山景， </td></tr><tr><td> PowerLab系统16/30 </td><td> AD工具</td><td>美国科罗拉多斯普林斯， </td></tr></tbody></table>

tilt testing with combined lower body negative pressure: a "gold standard" for measuring orthostatic tolerance

立位耐力（OT）是指能够保持心血管稳定直立时，对静压重力​​的作用，从而维持脑灌注，防止晕厥（昏倒）。有多种技术可用来评估OT和自重应力的影响血液循环后，一般的做法是在受控的实验室环境中再现晕厥前的事件（近昏厥发作）。需要引起这种反应的时间和/或程度的压力OT措施。任何技术用于确定OT:使立位耐力（各种原因引起的）和无症状对照组患者之间的区别是高度可重复性，使评价治疗干预，避免侵入性操作，这是众所周知的损害OT 1。 在20世纪80年代末，头直立倾斜试验用于诊断晕厥2。硅NCE，它已被用来评估OT不明原因的晕厥患者，以及在健康受试者研究的姿势心血管反射2-6。倾斜的协议包括三类:被动倾斜，伴随着药理挑衅的被动倾斜;结合下体负压（LBNP）和被动倾斜。然而，倾斜试验（和其他体位性压力测试的方式）的影响往往是很难再现，低灵敏度和特异性诊断体位性不耐受。 通常情况下，被动倾斜，包括体位性压力持续20-60分钟，直到晕厥发作的患者2-6。然而，此过程的主要缺点是它不能调用晕厥进行试验，在所有个体和相应的低灵敏度8,9。因此，不同的方法进行了探讨，以提高立位应激和提高灵敏度。 药理挑衅已被用来增加体位性挑战，例如使用异丙肾上腺素4,7,10,11或舌下硝酸12,13。然而，这些方法的主要缺点是在不可接受的跌幅的特异性10,14的成本的增加的灵敏度，具有高的正反应率立即给药后15。此外，侵入性操作有一定的药理挑衅，大大增加了假阳性率1。 另一种方法是被动倾斜试验相结合，提供了更强的立位应激与LBNP无侵入性程序或药物副作用，使用这项技术，开创教授罗杰Hainsworth又在20世纪90年代16-18。在几乎所有科目（允许在晕厥患者症状的识别），而区分不稳定型心绞痛患者，这种做法引发晕厥新界南总区有晕厥和健康对照组，特异性为92％，敏感性为85％，重复性为1.1±0.6分钟16,17。这，不仅可以诊断和病理评估19-22的评价，但也由于其高重复性23-30立位耐力的治疗方法。由于这些原因，我们认为这应该是体位性压力测试的"金标准"，因此，这将是本文中所描述的方法。

使用此协议，所有科目的经验晕厥，正常或异常反应的定义主要是根据观察到这种反应所需要的时间。 OT晕厥时间（分钟）被定义为从发病直立倾斜。 OT在健康志愿者中的典型值可以根据年龄和性别表1中可以看出，早在测试中表现出与立位耐力晕厥患者，有85％内控制17相比，23％的-20毫米汞柱阶段的结束测试。正常的阈值定为20％的发病率晕厥17。 <p class="jove_conten...

Watch this Scientific Journal Video about Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance at JoVE.com

Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance

我们描述了一个"金标准"，以评估使用倾斜试验（OT）联合下体负压（LBNP）的立位耐力。这可以结合与心血管反射控制的非侵入性评价。正常和不正常的反应被定义。

倾斜试验结合下体负压测量立位耐力的"金标准"

Orthostatic tolerance (OT)  refers to the ability to maintain cardiovascular stability when upright,  against the hydrostatic effects of gravity, and ...

tilt-testing-with-combined-lower-body-negative-pressure-gold-standard

Universidad de Cartagena UDEC

Research

Education

JoVE Core

JoVE Journal

Medical-Surgical Nursing

Medicine

Unit 1

An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities

SCIENTISTS IN ACTION

20.6K 次观看.  Simon Fraser University. 我们描述了一个"金标准"，以评估使用倾斜试验（OT）联合下体负压（LBNP）的立位耐力。这可以结合与心血管反射控制的非侵入性评价。正常和不正常的反应被定义。

视频: Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge.1-6 Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. 7, 8 
This video demonstrates a protocol for MMT, which has been taught to &ge;43 research staff who have performed &gt;800 assessments on &gt;280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale.7,9-11 Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. 1,2.

Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

危重病人中的应用手册肌力测试:下肢肌力测量方法

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, ...

科研

医学

Driving Simulation in the Clinic: Testing Visual Exploratory Behavior in Daily Life Activities in Patients with Visual Field Defects

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily life, despite similar visual deficits. We assume this could be due to variable development of compensatory strategies such as altered visual scanning behavior. Scanning compensatory therapy (SCT) is studied as part of the visual training after infarction next to vision restoration therapy. SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy1, not only in natural search tasks but also in mastering daily life activities2. Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition3. Martin et al.4 and Hayhoe et al.5 showed that behavior demonstrated in a laboratory setting cannot be assigned easily to a natural condition. Hence, our goal was to develop a study set-up which uncovers different compensatory oculomotor strategies quickly in a realistic testing situation: Patients are tested in the clinical environment in a driving simulator. SILAB software (Wuerzburg Institute for Traffic Sciences GmbH (WIVW)) was used to program driving scenarios of varying complexity and recording the driver's performance. The software was combined with a head mounted infrared video pupil tracker, recording head- and eye-movements (EyeSeeCam, University of Munich Hospital, Clinical Neurosciences).
The positioning of the patient in the driving simulator and the positioning, adjustment and calibration of the camera is demonstrated. Typical performances of a patient with and without compensatory strategy and a healthy control are illustrated in this pilot study. Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. Compensatory gaze behavior in a patient leads to a driving performance comparable to a healthy control, while the performance of a patient without compensatory behavior is significantly worse. The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential.

Patients with visual deficits after stroke report about different constraints in daily life most likely due to variable compensatory strategies, which are difficult to differentiate in clinical routine. We present a clinical set-up which allows measurement of different compensatory head- and eye-movement-strategies and evaluating their effects on driving performance.

驾驶模拟诊所:测试视觉与视野缺损的患者在日常活动中的探索行为

Patients suffering from homonymous hemianopia after infarction of the posterior cerebral artery (PCA) report different degrees of constraint in daily ...

Dynamic Lung Tumor Tracking for Stereotactic Ablative Body Radiation Therapy

Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable risks for normal tissue injury and the hazards of physical tumor miss. A first-of-its-kind SBRT platform achieves high-precision ablative radiation treatment through a combination of versatile real-time imaging solutions and sophisticated tumor tracking capabilities. It uses dual-diagnostic kV x-ray units for stereoscopic open-loop feedback of cancer target intrafraction movement occurring as a consequence of respiratory motions and heartbeat. Image-guided feedback drives a gimbaled radiation accelerator (maximum 15 x 15 cm field size) capable of real-time &#177;4 cm pan-and-tilt action. Robot-driven &#177;60&#176; pivots of an integrated &#177;185&#176; rotational gantry allow for coplanar and non-coplanar accelerator beam set-up angles, ultimately permitting unique treatment degrees of freedom. State-of-the-art software aids real-time six dimensional positioning, ensuring irradiation of cancer targets with sub-millimeter accuracy (0.4 mm at isocenter). Use of these features enables treating physicians to steer radiation dose to cancer tumor targets while simultaneously reducing radiation dose to normal tissues. By adding respiration correlated computed tomography (CT) and 2-[18F] fluoro-2-deoxy-&#7429;-glucose (18F-FDG) positron emission tomography (PET) images into the planning system for enhanced tumor target contouring, the likelihood of physical tumor miss becomes substantially less1. In this article, we describe new radiation plans for the treatment of moving lung tumors.

Stereotactic ablative body radiation therapy (SBRT) involves the precise delivery of high-dose radiation to cancer tumor targets. A novel SBRT platform offers a first-of-its-kind gimbaled radiation accelerator mounted within a pivoting O-ring gantry capable of dynamic image-guided tumor tracking. Here, we describe dynamic tumor tracking for lung targets.

动态肺肿瘤跟踪烧蚀立体定向放射身体治疗

Physicians considering stereotactic ablative body radiation therapy (SBRT) for the treatment of extracranial cancer targets must be aware of the sizeable ...

Characterization of Metabolic Status in Nonhuman Primates with the Intravenous Glucose Tolerance Test

The intravenous glucose tolerance test (IVGTT) plays a key role in the characterization of glucose homeostasis. When taken together with serum biochemical profiles, inclusive of blood glucose levels in both the fed and fasted state, HbA1c, insulin levels, clinical history of diet, body composition, and body weight status, an assessment of normal and abnormal glycemic control can be made. Interpretation of an IVGTT is done through measurement of changes in glucose and insulin levels over time in relation to the dextrose challenge. Critical components to be considered are: peak glucose and insulin levels reached in relation to T0 (end of glucose infusion), the glucose clearance rate K derived from the slope of rapid glucose clearance in the first 20 min (T1 to T20), the time to return to glucose baseline, and the area under the curve (AUC). These IVGTT measures will show characteristic changes as glucose homeostasis moves from a healthy to a diseased metabolic state5. Herein we will describe the characterization of nonhuman primates (Rhesus and Cynomolgus macaques), which are the most relevant animal model of Type II diabetes (T2D) in humans and the IVGTT and clinical profiles of these animals from a lean healthy, to obese dysmetabolic, and T2D state 8, 10, 11.

The goal of this protocol is to present a standard method to perform intravenous glucose tolerance tests (IVGTTs) to assess glycemic control in nonhuman primates and assess their metabolic status from healthy to dysmetabolic.

代谢状态的表征非人灵长类动物与静脉葡萄糖耐量试验

The intravenous glucose tolerance test (IVGTT) plays a key role in the characterization of glucose homeostasis. When taken together with serum biochemical ...

The Lower Body Positive Pressure Treadmill for Knee Osteoarthritis Rehabilitation

Here, based on a clinician&rsquo;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in addition to a clinical, functional assessment methodology, including details for further encouragement of the development of non-drug surgical intervention strategies in knee osteoarthritis patients. However, we only present the effect of LBPP training in improvement of pain and knee function in one patient through three-dimensional gait analysis. The exact, long-term effects of this approach should be explored in future studies.

Here, based on a clinician&#8217;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in addition to a clinical, functional assessment methodology, including details for further encouragement of the development of non-drug surgical intervention strategies in knee osteoarthritis patients. However, we only present the effect of LBPP training in improvement of pain and knee function in one patient through three-dimensional gait analysis. The exact, long-term effects of this approach should be explored in future studies.

下体正压跑步机用于膝关节骨关节炎康复

Here, based on a clinician&rsquo;s point-of-view, we propose a two-model lower body positive pressure (LBPP) protocol (walking and squatting models) in ...

A Rat Carotid Artery Pressure-Controlled Segmental Balloon Injury with Periadventitial Therapeutic Application

Cardiovascular disease remains the leading cause of death and disability worldwide, in part due to atherosclerosis. Atherosclerotic plaque narrows the luminal surface area in arteries thereby reducing adequate blood flow to organs and distal tissues. Clinically, revascularization procedures such as balloon angioplasty with or without stent placement aim to restore blood flow. Although these procedures reestablish blood flow by reducing plaque burden, they damage the vessel wall, which initiates the arterial healing response. The prolonged healing response causes arterial restenosis, or re-narrowing, ultimately limiting the long-term success of these revascularization procedures. Therefore, preclinical animal models are integral for analyzing the pathophysiological mechanisms driving restenosis, and provide the opportunity to test novel therapeutic strategies. Murine models are cheaper and easier to operate on than large animal models. Balloon or wire injury are the two commonly accepted injury modalities used in murine models. Balloon injury models in particular mimic the clinical angioplasty procedure and cause adequate damage to the artery for the development of restenosis. Herein we describe the surgical details for performing and histologically analyzing the modified, pressure-controlled rat carotid artery balloon injury model. Additionally, this protocol highlights how local periadventitial application of therapeutics can be used to inhibit neointimal hyperplasia. Lastly, we present light sheet fluorescence microscopy as a novel approach for imaging and visualizing the arterial injury in three-dimensions.

The rat carotid artery balloon injury mimics the clinical angioplasty procedure performed to restore blood flow in atherosclerotic vessels. This model induces the arterial injury response by distending the arterial wall, and denuding the intimal layer of endothelial cells, ultimately causing remodeling and an intimal hyperplastic response.

大鼠胡萝卜动脉压力控制段气球损伤与腹腔ventit 治疗应用

Cardiovascular disease remains the leading cause of death and disability worldwide, in part due to atherosclerosis. Atherosclerotic plaque narrows the ...

Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice

Blood pressure (BP) and heart rate (HR) are both controlled by the autonomic nervous system (ANS) and are closely intertwined due to reflex mechanisms. The baroreflex is a key homeostatic mechanism to counteract acute, short-term changes in arterial BP and to maintain BP in a relatively narrow physiological range. BP is sensed by baroreceptors located in the aortic arch and carotid sinus. When BP changes, signals are transmitted to the central nervous system and are then communicated to the parasympathetic and sympathetic branches of the autonomic nervous system to adjust HR. A rise in BP causes a reflex decrease in HR, a drop in BP causes a reflex increase in HR.
Baroreflex sensitivity (BRS) is the quantitative relationship between changes in arterial BP and corresponding changes in HR. Cardiovascular diseases are often associated with impaired baroreflex function. In various studies reduced BRS has been reported in e.g., heart failure, myocardial infarction, or coronary artery disease. 
Determination of BRS requires information from both BP and HR, which can be recorded simultaneously using telemetric devices. The surgical procedure is described beginning with the insertion of the pressure sensor into the left carotid artery and positioning of its tip in the aortic arch to monitor arterial pressure followed by the subcutaneous placement of the transmitter and ECG electrodes. We also describe postoperative intensive care and analgesic management. After a two-week period of post-surgery recovery long-term ECG and BP recordings are performed in conscious and unrestrained mice. Finally, we include examples of high-quality recordings and the analysis of spontaneous baroreceptor sensitivity using the sequence method.

The baroreflex is a heart-rate regulation mechanism by the autonomic nervous system in response to blood-pressure changes. We describe a surgical technique to implant telemetry transmitters for continuous and simultaneous measurement of electrocardiogram and blood pressure in mice. This can determine spontaneous baroreflex sensitivity, an important prognostic marker for cardiovascular disease.

植入遥测心电图和血压递质组合以确定意识小鼠的自发压力反射敏感性

Blood pressure (BP) and heart rate (HR) are both controlled by the autonomic nervous system (ANS) and are closely intertwined due to reflex mechanisms. ...

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism

Lung transplantation (LTx) remains the standard of care for end-stage lung disease. A shortage of suitable donor organs and concerns over donor organ quality exacerbated by excessive geographic transportation distance and stringent donor organ acceptance criteria pose limitations to current LTx efforts. Ex situ lung perfusion (ESLP) is an innovative technology that has shown promise in attenuating these limitations. The physiologic ventilation and perfusion of the lungs outside of the inflammatory milieu of the donor body affords ESLP several advantages over traditional cold static preservation (CSP). There is evidence that negative pressure ventilation (NPV) ESLP is superior to positive pressure ventilation (PPV) ESLP, with PPV inducing more significant ventilator-induced lung injury, pro-inflammatory cytokine production, pulmonary edema, and bullae formation. The NPV advantage is perhaps due to the homogenous distribution of intrathoracic pressure across the entire lung surface. The clinical safety and feasibility of a custom NPV-ESLP device have been demonstrated in a recent clinical trial involving extender criteria donor (ECD) human lungs. Herein, the use of this custom device is described in a juvenile porcine model of normothermic NPV-ESLP over a 12 h duration, paying particular attention to management techniques. Pre-surgical preparation, including ESLP software initialization, priming, and de-airing of the ESLP circuit, and the addition of anti-thrombotic, anti-microbial, and anti-inflammatory agents, is specified. The intraoperative techniques of central line insertion, lung biopsy, exsanguination, blood collection, cardiectomy, and pneumonectomy are described. Furthermore, particular focus is paid to anesthetic considerations, with anesthesia induction, maintenance, and dynamic modifications outlined. The protocol also specifies the custom device's initialization, maintenance, and termination of perfusion and ventilation. Dynamic organ management techniques, including alterations in ventilation and metabolic parameters to optimize organ function, are thoroughly described. Finally, the physiological and metabolic assessment of lung function is characterized and depicted in the representative results.

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism

This paper describes a porcine model of negative pressure ventilation ex situ lung perfusion, including procurement, attachment, and management on the custom-made platform. Focus is made on anesthetic and surgical techniques, as well as troubleshooting.

非原位负压通气肺灌注:肺功能和代谢的评估

Lung transplantation (LTx) remains the standard of care for end-stage lung disease. A shortage of suitable donor organs and concerns over donor organ ...

Evaluation of a Point-of-Care Testing Analyzer for Measuring Peripheral Blood Leukocytes

White blood cell (WBC) is an important indicator of inflammation in the body, and it can help distinguish between bacterial and viral infections. At present, most primary medical institutions in China have a poor percentage of adoption of blood-testing technology, and a hematology detection system with a high price to performance ratio and easy operation is urgently needed in primary healthcare centers. This paper introduces the principle and operation procedures of a point-of-care testing (POCT) card-based leukocyte analyzer (evaluated system), which was used to detect WBC indexes such as neutrophils, lymphocytes, and intermediate group cells (including eosinophils, basophils, and monocytes) in whole blood. The results from the evaluated system were compared to those from two commercial automatic hematology analyzers (reference system). The correlation and consistency between the evaluated system and the commercial reference systems were analyzed. The results showed that WBC count and number of granulocytes detected by the evaluated and reference systems showed a strong positive correlation (rs = 0.972 and 0.973, respectively), while the number of lymphocytes showed a relatively low correlation (rs = 0.851). A Bland-Altman plot showed that the major difference between the values detected by the evaluated system and the reference systems is within 95% limits of agreement (LoA), indicating that the two systems are in good agreement. In conclusion, the evaluated system has an excellent correlation, robust consistency, and a reliable comparison with the results of the widely used automatic hematology analyzers. It is ideal for WBC detection in primary medical institutions where a full-automatic five-category hematology analyzer is unavailable, especially during the COVID-19 normalized prevention and control period.

A protocol to measure peripheral blood leukocytes using a POCT card-based leukocyte analyzer is presented here. Same blood samples were tested by two automated hematology analyzers to evaluate the consistency and accuracy of the results. The results showed that the evaluated analyzer had a good correlation with the reference system.

用于测量外周血白细胞的床旁测试分析仪的评估

White blood cell (WBC) is an important indicator of inflammation in the body, and it can help distinguish between bacterial and viral infections. At ...

一种 Zanba-Stir-Fried Tiebangchui 工艺优化方法

Optimization of Processing Technology for Tiebangchui with Zanba Based on CRITIC Combined with Box-Behnken Response Surface Method

The dried root of Aconitum pendulum Busch., called Tiebangchui (TBC) in Chinese, is one of the most famous Tibetan medicines. It is a widely used herb in northwest China. However, many cases of poisoning have occurred because of TBC's intense toxicity and because its therapeutic and toxic doses are similar. Therefore, finding a safe and effective method to reduce its toxicity is an urgent task. A search through the Tibetan medicine classics shows that the processing method of TBC stir-fried with Zanba was recorded in the "Processing specification of Tibetan medicine of Qinghai Province (2010)". However, the specific processing parameters are not yet clear. Thus, this study aims to optimize and standardize the processing technology of Zanba-stir-fried TBC.
First, a single-factor experiment was conducted on four factors: the slice thickness of TBC, amount of Zanba, processing temperature, and time. With monoester and diester alkaloid contents in Zanba-stir-fried TBC as indexes, CRITIC combined with the Box-Behnken response surface method was used to optimize the processing technology of Zanba-stir-fried TBC. The optimized processing conditions of Zanba-stir-fried TBC were a TBC slice thickness of 2 cm, three times more Zanba than TBC, a processing temperature of 125 &#176;C, and 60 min of stir-frying. This study determined the optimized and standard processing conditions for the usage of Zanba-stir-fried TBC, thus providing an experimental basis for the safe clinical use and industrial production of Zanba-stir-fried TBC.

作者聚焦：基于 CRITIC 结合 Box-Behnken 响应面法的 Tiebangchui 与 Zanba 加工工艺优化  

The present protocol describes an efficient and standard detoxification processing method for Zanba-stir-fried Tiebangchui using CRITIC combined with the Box-Behnken response surface method.

基于CRITIC结合Box-Behnken响应面法的铁邦岀与赞坝加工工艺优化

The dried root of Aconitum pendulum Busch., called Tiebangchui (TBC) in Chinese, is one of the most famous Tibetan medicines. It is a widely used herb in ...