这个项目是由国家中风基金会，亨特医学研究所（HMRI）和国家健康与医学研究理事会（NH＆MRC的），澳大利亚。特别感谢卫生车间员工在纽卡斯尔大学的教师，他们的技术专长。

1。头骨穿透<ol><li>麻醉与异氟醚（5％的诱导，维护1.5-2％）在70％N2和30％O 2的老鼠。麻醉诱导后，将大鼠俯卧变暖板，老鼠的鼻子在麻醉鼻锥定位。 </li><li>虽然维持麻醉，固定在头部立体定向框架，插入耳酒吧，直到头部稳定。确保呼吸不受损害。 （ 图2 A）。 </li><li>头皮皮下注入持久的局部麻醉，布比卡因0.3毫升0.5％（辉瑞公司，澳大利亚），然后才作出一个1.5厘米的皮肤中线头部切口。 （无菌文书和手套，应使用）。 </li><li>钝性解剖的软组织及周围的肌肉，清楚地定位Lambda和前囟门。收回的皮肤和结缔组织。 </li><li>暴露颅骨施加压力，制止任何出血。颅骨出血过多可能被烧灼。 </li><li>使用牙科DRILL与1毫米尖端的毛刺，毛刺一个洞2毫米宽的右顶骨。伯尔孔横向和2毫米，2毫米前囟门后，以避免上矢状窦，确保安置的ICP传感器是在缺血的领土，中风的研究。替代的位置，也同样适用于其他应用程序。伯尔孔深度其中硬脑膜以上的头骨变为半透明。 （ 图2-B的 ）。 </li><li>更换0.5毫米尖毛刺毛刺去除颅骨洞基地。 </li><li>当头骨开始开裂，使用45°钳清除所有剩余的头骨，清除杂物，确保孔的基础。 （ 图3）。 </li></ol> 2。螺杆修改和插入<ol><li>通过六角头螺丝，使用一台车床和0.7毫米的钻头钻一个0.7毫米的孔。 </li><li>监测螺丝插入孔内转动约1.5圈（使用的最低金额原来需要，以确保在颅骨螺钉，以免损害底层组织）。 （ 图2-C和图4）。 </li><li>伯尔第二洞一个在左顶骨锚定螺钉，外侧2毫米和2毫米，前囟门后。这个洞并不需要完整的头骨渗透，因此，1毫米尖端毛刺用于薄螺丝插入头骨。 </li><li>插入第二个孔，2×4毫米六角头螺钉。此螺钉固定的牙科水泥，因此监测螺丝头骨。 </li><li>使用移液管混合，适用于牙科水泥单体及聚合物，螺丝头的基础。 </li><li>允许牙科水泥干燥至少10分钟。 </li></ol> 3。颅内压力传感器插入<ol><li>用白色涂改液，标志着尖端的光纤传感器从4毫米。 </li><li>填补了用无菌生理盐水（0.9％）的监测螺丝孔，确保没有气泡内螺纹。 </li><li>插入ICP探头4毫米到螺钉，使探头尖端是螺杆年底的水平。确保针尖不会刺破硬脊膜。 </li><li>调整螺钉内探针的尖端，可以观察到，直到ICP跟踪反映通风和血压脉冲波。 （ 图5）。 </li></ol> 4。形成一个密闭的密封<ol><li>一个密封的密封是必须准确的ICP阅读。混合一种粘稠的生物相容性嵌缝材料中的比例为1:1的单体和聚合物。因为压力传感器探头的尖端，这是的挖空螺丝内，嵌缝材料的应用，以光纤探针轴有没有压力传感器灵敏度的影响。 </li><li>应用探头周围的一层薄薄的监测螺丝头。避免取代ICP探头。 </li><li>允许设置为5分钟。 </li><li>申请第二次裁员呃，整个监测螺钉和探头周围的嵌缝材料。从任何裂隙在嵌缝材料，确保没有液体泄漏。 （ 图的2-D）。 </li><li>卸下耳朵酒吧。 </li><li>老鼠可能会保持在俯卧位，或小心地将在ICP监测仰卧位旋转。 </li><li>完成过程的示意图所示（ 图6）。 </li></ol> 5。颅内压传感器的拆卸和重新安置<ol><li>在完成ICP监测，ICP传感器可能会被轻轻拉螺杆和嵌缝材料导管。 </li><li>桑巴传感器应立即放入1％Terg-A酶的解决方案，以防止尖端腐蚀。 </li><li>孔留在嵌缝材料应包括与嵌缝材料的附加层。 （大鼠，在这个阶段可能会被唤醒）。 </li><li>重新插入额外的监测桑巴导管，切嵌缝材料在螺丝头的水平。 </li><li>重复步骤3.2 - 5.3。 </li></ol> 6。代表结果 图5是ICP的读数超过十秒钟的代表性。在基线，在大鼠的平均ICP是6毫米汞柱。在图5所示的短周期事件反映血压脉冲波。周期较长的事件表明通风事件。请注意，SAMBA传感器反映了通风幅度为3-4毫米汞柱，脉搏振幅1-2毫米汞柱。 在每次实验来验证的桑巴传感器的位置，ICP的痕迹，应进行腹部按压和呼吸活动，如呼吸暂停期间，为响应。 图7描述了一个腹部的压缩。 在大多数实验invo观察期间的呼吸暂停（ 如图8所示）<html> lving自发呼吸的动物。呼吸上呼吸道（膈肌传感器）和动脉压的痕迹变形的情况下，这些事件被认定生理记录。相当于改变在ICP跟踪验证ICP探头定位。 图9描述了一个典型的ICP跟踪后去除耳酒吧（步骤4.6）。插入耳酒吧轻微的头骨和在颅内量随之中断，在压缩的步骤1.2结果，从而增加ICP。如果传感器被正确定位，ICP将下降至少4 - 5毫米汞柱，去除耳酒吧。 可用于组织学分析，以检查皮质区立即下的压力传感器和螺杆造成任何损害。创伤性和非创伤性的螺丝插入的一个例子如图4所示。 _upload/3689/3689fig1.jpg"/&gt; 图1。充满液体VS桑巴ICP备痕迹。ICP是通过Samba的光纤导管（ 顶部 ）和一个充满液体的导管（ 底部 ），同时记录。平均ICP值相似，在这两个痕迹，但充满流体的导管信号，特别是打击较清晰的呼吸和动脉血压波形与光纤导管。 <img alt="图2" src="/files/ftp_upload/3689/3689fig2.jpg" /> 图2。颅内压导管插入程序。大鼠的头部被固定在一个立体框架耳酒吧和麻醉鼻锥的研究[A]。是钻了一个洞，直径约2毫米，成右顶骨[A]。 2×4毫米0.7毫米的孔与轴螺丝插入[J]。锚固螺杆插入左顶骨和头骨和牙科水泥覆盖的手术部位。 ICP备cathetER（ 黑色箭头 ），然后插入螺丝孔和一个密封的密封嵌缝材料（ 白色箭头 ）研究[D]。主食（规模）= 12毫米x 5毫米。 <img alt="图3" src="/files/ftp_upload/3689/3689fig3.jpg" /> 图3。监测毛刺螺丝孔定位 。头骨被清除结缔组织找到拉姆达（ 黑色星号 ）和前囟门（ 白星号 ）和孔钻外侧2毫米和2毫米，前囟门后。孔离开硬脑膜和软脑膜血管（ 黑色箭头 ）完整的碎片被清除。主食（规模）= 12毫米x 5毫米。 <img alt="图4" src="/files/ftp_upload/3689/3689fig4.jpg" /> 图4。 ICP监测螺杆仪表24小时后大鼠脑组织学。Haemotoxylin和曙红染色，6微米的冠状切片。左:非创伤性的螺丝插入。右:创伤螺丝插入，苍白面积描述中风受损的区域（ 箭头 ）具有相似的细胞形态受损的组织。插入4X目标。 <img alt="图5" src="/files/ftp_upload/3689/3689fig5.jpg" /> 图5。典型ICP备微量脉冲压力波幅度较小（*）的事件描述。通风反映较长的周期（＃）的事件。 <img alt="图6" src="/files/ftp_upload/3689/3689fig6.jpg" /> 图6。 ICP探针插入示意图 。图表说明支持螺丝（ 右 ）和嵌缝材料涂层ICP探入螺丝（ 左 ）的位置。 <img alt="图7" src="/files/ftp_upload/3689/3689fig7.jpg" /> 图7。腹部的压缩，腹部被暂时压缩（约1秒），以验证ICP信号的可行性。压缩结果在脑静脉回流减少，增加颅内量，从而增加ICP备。动脉压（Pa）仅下降后初始ICP崛起。 <img alt="图8" src="/files/ftp_upload/3689/3689fig8.jpg" /> 图8。呼吸暂停期间，暂时停止呼吸，在反映膈肌传感器跟踪，动脉压（Pa）微量元素的ICP跟踪。 <img alt="图9" src="/files/ftp_upload/3689/3689fig9.jpg" /> 图9。耳酒吧去除。ICP应该放弃拆除的立体框架耳酒吧。

<ol>
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我们什么都没有透露。

这里介绍的过程，使颅内压非常灵敏，准确的记录。这种微创技术，避免了显着的脑外伤，定位在硬膜外腔压力传感器和脑组织或心室。 的关键步骤包括:1）通过头骨钻 - 护理必须采取不刺破硬脊膜或损害脑组织的基本; 2）确保紧的密封嵌缝材料 - 如果有任何泄漏，ICP跟踪将不会可靠。当适当的位置，ICP传感器读数将不仅ICP备准确跟踪，但呼吸和心率。与灵感，更负面的胸腔...

<table border="1"><tbody><tr><td> 试剂名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论 </td></tr><tr><td>牙科水泥单体</td><td>亨利施恩</td><td> VX-SC500MLL </td><td></td></tr><tr><td>牙科水泥聚合物</td><td>亨利施恩</td><td> VX-SC1000GCL4 </td><td></td></tr><tr><td>牙钻毛刺大小12 </td><td> gunz牙科</td><td> EL104S001012/10 </td><td></td></tr><tr><td>牙钻毛刺大小6 </td><td> gunz牙科</td><td> EL104S001006/10 </td><td></td></tr><tr><td>金属螺丝</td><td>五金店</td><td></td><td> 2×4毫米，六角头。 （0.7毫米钻孔轴实验室修改） </td></tr><tr><td> SAMBA的控制单元</td><td>哈佛仪器</td><td> 50433102 </td><td></td></tr><tr><td> SAMBA的传感器</td><td>哈佛仪器</td><td> 50461122 </td><td> 420唱片，15厘米的裸光纤，无线电不透明涂料</td></tr><tr><td> silagum影音单嵌缝材料</td><td> gunz牙科</td><td>的RG 9152 </td><td> vinylpolysiloxanes，氢聚硅氧烷，填料，颜料，添加剂，催化剂plantinum </td></tr><tr><td> terg的一个酶</td><td> alconox，公司</td><td> 1304 </td><td>活性酶洗衣粉</td></tr></tbody></table>

epidural intracranial pressure measurement in rats using a fiber-optic pressure transducer

升高颅内压（ICP）是一个重大的问题，在缺血性脑损伤的几种形式，包括中风，脑外伤和心脏骤停。这个海拔可能导致进一步的神经损伤，小脑幕1,2,3,4症，脑压，神经赤字或增加脑梗塞2,4的 ​​形式。目前的治疗方法往往不足以控制在临床上设置5,6,7 ICP升高。因此，有一个准确的ICP测量方法，在动物模型中需要进一步我们的基本机制的理解和发展新的治疗方法为ICP升高。 在临床和实验设置ICP备无法估计没有直接测量。目前存在的几种方法ICP导管插入。这些脑室导管已成为临床上的"金标准"的ICP测量人类8。这种方法INVolves颅骨部分切除和导管通过脑组织的仪器。因此，脑室导管感染发生率6-11％9。出于这个原因，硬膜下和硬膜外cannulations的缺血性损伤的动物模型已成为首选方法。 各种ICP测量技术已被改编为动物模型，其中，充满液体的的遥测导管10和固态导管是最常用的11,12,13,14,15。充液系统开发行中的气泡，很容易造成假ICP备读数。固态探头避免此问题（ 图1）。另外一个问题是没有根据头骨或装修成心室导管造成脑损伤，可能会改变实验结果。因此，我们已经开发出一种方法，连续硬膜外腔放置一个ICP导管，但避免了NE插入颅骨和大脑之间。 一个光纤压力导管（420LP，SAMBA传感器，瑞典），用来衡量在硬膜外位置ICP因为压力传感器（导管很尖）的位置被发现产生在这个模型中的信号高保真ICP 。有其他厂家类似的光纤技术，可与我们的方法使用的13。替代固态导管，导管尖端一侧有压力传感器，将不适合这种模式的信号将挫伤由监测螺丝的存在。 在这里，我们提出了一个相对简单和准确的方法来衡量ICP备。这种方法可用于广泛的跨ICP备相关的动物模型。

Watch this Scientific Journal Video about Epidural Intracranial Pressure Measurement in Rats Using a Fiber-optic Pressure Transducer at JoVE.com

Epidural Intracranial Pressure Measurement in Rats Using a Fiber-optic Pressure Transducer

介绍一种新的技术来记录颅骨内的压力。微创的方法是使用一个光纤压力传感系统，准确地测量不会造成重大的脑外伤颅内压（ICP）在麻醉大鼠。该技术可以用在广泛的实验模型。

硬膜外颅内压测量中使用的光纤压力传感器的大鼠

Elevated intracranial pressure (ICP) is a significant problem in several forms of ischemic brain injury including stroke, traumatic brain injury and ...

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JoVE Journal

Medicine

20.8K 次观看.  The University of Newcastle. 介绍一种新的技术来记录颅骨内的压力。微创的方法是使用一个光纤压力传感系统，准确地测量不会造成重大的脑外伤颅内压（ICP）在麻醉大鼠。该技术可以用在广泛的实验模型。

视频: Epidural Intracranial Pressure Measurement in Rats Using a Fiber-optic Pressure Transducer

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 ...

科研

医学

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50&#8211;60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage.

We describe a stepwise procedure for creating pressure overload and left ventricular hypertrophy in Wistar rats by constriction of the ascending aorta using a small metallic clip. This model is extensively used for studying remodeling changes during cardiac hypertrophy and for identifying and evaluating strategies for regression of such changes.

大鼠建立压力超负荷心肌肥厚模型在升主动脉缩窄

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart ...

Assessing Myogenic Response and Vasoactivity In Resistance Mesenteric Arteries Using Pressure Myography

Small resistance arteries constrict and dilate respectively in response to increased or decreased intraluminal pressure; this phenomenon known as myogenic response is a key regulator of local blood flow. In isobaric conditions small resistance arteries develop sustained constriction known as myogenic tone (MT), which is a major determinant of systemic vascular resistance (SVR). Hence, ex vivo&#160;pressurized preparations of small resistance arteries are major tools to study microvascular function in near-physiological states. To achieve this, a freshly isolated intact segment of a small resistance artery (diameter ~260 &#956;m) is mounted onto two small glass cannulas and pressurized. These arterial preparations retain most in vivo characteristics and permit assessment of vascular tone in real-time. Here we provide a detailed protocol for assessing vasoactivity in pressurized small resistance mesenteric arteries from rats; these arteries develop sustained vasoconstriction - approximately 25% of maximal diameter - when pressurized at 70 mmHg. These arterial preparations may be used to study the effect of investigational compounds on relationship between intra-arterial pressure and vasoactivity and determine changes in microvascular function in animal models of various diseases.

Pressure myography is used to assess vasoactivity of small arteries that develop sustained constriction when pressurized. This manuscript provides a detailed protocol to assess in isolated segments of small mesenteric arteries from rats, vasoactivity and the effect of intraluminal pressure on vascular diameter.

评估肌反应及血管活性阻力肠系膜动脉使用压力肌动描记

Small resistance arteries constrict and dilate respectively in response to increased or decreased intraluminal pressure; this phenomenon known as myogenic ...

Measurement of the Pressure-volume Curve in Mouse Lungs

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential phenotypic changes are best assessed by measurement of the changes in lung elasticity. To best understand specific mechanisms underlying such pathologies in mice, it is essential to make functional measurements that can reflect the developing pathology. Although there are many ways to measure elasticity, the classical method is that of the total lung pressure-volume (PV) curve done over the whole range of lung volumes. This measurement has been made on adult lungs from nearly all mammalian species dating back almost 100 years, and such PV curves also played a major role in the discovery and understanding of the function of pulmonary surfactant in fetal lung development. Unfortunately, such total PV curves have not been widely reported in the mouse, despite the fact that they can provide useful information on the macroscopic effects of structural changes in the lung. Although partial PV curves measuring just the changes in lung volume are sometimes reported, without a measure of absolute volume, the nonlinear nature of the total PV curve makes these partial ones very difficult to interpret. In the present study, we describe a standardized way to measure the total PV curve. We have then tested the ability of these curves to detect changes in mouse lung structure in two common lung pathologies, emphysema and fibrosis. Results showed significant changes in several variables consistent with expected structural changes with these pathologies. This measurement of the lung PV curve in mice thus provides a straightforward means to monitor the progression of the pathophysiologic changes over time and the potential effect of therapeutic procedures.

Here we present a protocol to simply and reliably measure the lung pressure-volume curve in mice, showing that it is sufficiently sensitive to detect phenotypic parenchymal changes in two common lung pathologies, pulmonary fibrosis and emphysema. This metric provides a means to quantify the lung&#8217;s structural changes with developing pathology.

在小鼠肺压力容积曲线的测量

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential ...

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

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

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

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

宫内遥测来衡量鼠标收缩压力<em&gt;在体内</em

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

Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye

The mechanical characteristics of the trabecular meshwork (TM) are linked to outflow resistance and intraocular pressure (IOP) regulation. The rationale behind this technique is the direct observation of the mechanical response of the TM to acute IOP elevation. Prior to scanning, IOP is measured at baseline and during IOP elevation. The limbus is scanned by spectral-domain optical coherence tomography at baseline and during IOP elevation (ophthalmodynamometer (ODM) applied at 30 g force). Scans are processed to enhance visualization of the aqueous humor outflow pathway using ImageJ. Vascular landmarks are used to identify corresponding locations in baseline and IOP elevation scan volumes. Schlemm canal (SC) cross-sectional area (SC-CSA) and SC length from anterior to posterior along its long axis are measured manually at 10 locations within a 1 mm segment of SC. Mean inner to outer wall distance (short axis length) is calculated as the area of SC divided by its long axis length. To examine the contribution of adjacent tissues to the effect IOP elevations, measurements are repeated without and with smooth muscle relaxation with instillation of tropicamide. TM migration into SC is resisted by TM stiffness, but is enhanced by the support of its attachment to adjacent smooth muscle within the ciliary body. This technique is the first to measure the living human TM response to pressure elevation in situ under physiological conditions within the human eye.

Trabecular meshwork (TM) migration into Schlemm&#8217;s canal space can be induced by acute pressure elevation by ophthalmodynamometer, and observed by spectral domain optical coherence tomography. The goal of this method is to quantify the morphometric response of the living outflow tract to acute pressure elevation in living tissues in situ.

小梁响应压升高在活的人类眼睛

The mechanical characteristics of the trabecular meshwork (TM) are linked to outflow resistance and intraocular pressure (IOP) regulation. The rationale ...

Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. Indeed, research focusing on the discovery of new potential therapeutic targets using genetically altered mice requires a reliable, long-term assessment of the systemic arterial pressure variation. Currently, the gold standard for obtaining long-term measurements of blood pressure in ambulatory mice uses implantable radio-transmitters, which require&#160;artery cannulation. This technique eliminates the need for tethering, restraining, or anesthetizing the animals which introduce stress and artifacts during data sampling. However, arterial blood pressure monitoring in mice via catheterization can be rather challenging due to the small size of the arteries. Here we present a step-by-step guide to illustrate the crucial key passages for a successful subcutaneous implantation of radio-transmitters and carotid artery cannulation in mice. We also include examples of long-term blood pressure activity taken from freely moving mice after a period of post-surgery recovery. Following this procedure will allow reliable direct blood pressure recordings from multiple animals simultaneously.

The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

自由活动小鼠使用遥测长期血压测量

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. ...

Spatial Measurements of Perfusion, Interstitial Fluid Pressure and Liposomes Accumulation in Solid Tumors

The heterogeneous intra-tumoral accumulation of liposomes is a critical determinant of their efficacy. Both the chaotic tumor microcirculation and elevated IFP are linked to the heterogeneous intra-tumoral distribution of nanotechnology-based drug delivery systems such as liposomes. In the present study, the relationship between tumor microcirculation, elevated IFP, and accumulation of nanoparticles was investigated through in vivo experimentation. This was accomplished by evaluation of the tumor microcirculation using dynamic contrast enhanced computed tomography (DCE-CT) and measurement of tumor IFP using a novel image-guided robotic needle placement system connected to the micro-CT scanner. The intra-tumoral accumulation of liposomes was determined by CT image-based assessment of a nanoparticle liposomal formulation that stably encapsulate the contrast agent iohexol (CT-liposomes). CT imaging allowed for co-localization of the spatial distribution of tumor hemodynamics, IFP and CT-liposome accumulation in an individual subcutaneous xenograft mouse model of breast cancer. Measurements led to the discovery that perfusion and plasma volume fraction are strong mediators of the intra-tumoral distribution of liposomes. Furthermore, the results suggest that IFP plays an indirect role in mediating liposome distribution through modulating blood flow.

The heterogeneous intra-tumoral accumulation of liposomes has been linked to an abnormal tumor microenvironment. Herein methods are presented to measure tumor microcirculation by perfusion imaging and elevated interstitial fluid pressure (IFP) using an image-guided robotic system. Measurements are compared to the intra-tumoral accumulation of liposomes, determined using volumetric micro-CT imaging.

灌注的空间测量，实体肿瘤间质流体压力和脂质体积累

The heterogeneous intra-tumoral accumulation of liposomes is a critical determinant of their efficacy. Both the chaotic tumor microcirculation and ...

Cavernous Nerve Stimulation and Recording of Intracavernous Pressure in a Rat

The stimulation of the cavernous nerve (CN) and measurement of intracavernous pressure (ICP) have been used extensively to test and evaluate therapies for erectile dysfunction. However, the methods used vary between laboratories, and pitfalls still exist. The goal of this study was to describe a surgical technique that would provide a reliable and reproducible model. By exposing the ischiocavernosus muscle at its point of insertion on the ischial tuberosity, the penile crus could be cannulated with minimal dissection and injury to the structures involved in erectile function. Repeated stimulation of the CN, without the need for lifting and drying, was achieved by using a 125 &#181;m bipolar silver electrode and biocompatible silicon glue to isolate the electrode-nerve complex. This method prevents neuropraxia by reducing stretching and drying the nerve and provides complete isolation of the nerve, negating electrical leakage and preventing stimulation of alternative pathways.

This study describes a simplified surgical procedure and technique for performing cavernous nerve stimulation with the isolation of the nerve-electrode complex using silicone glue and intracavernous pressure measurement.

大鼠海绵状神经刺激与海绵压力记录

The stimulation of the cavernous nerve (CN) and measurement of intracavernous pressure (ICP) have been used extensively to test and evaluate therapies for ...

Measurement of the Hepatic Venous Pressure Gradient and Transjugular Liver Biopsy

Here we provide a detailed protocol describing the clinical procedure of hepatic venous pressure gradient (HVPG) measurement in patients with advanced chronic liver disease followed by an instruction for transjugular biopsy. Under local anesthesia and ultrasound guidance, a catheter introducer sheath is placed in the right internal jugular vein. Using&#160;fluoroscopic guidance, a balloon catheter is advanced into the inferior vena cava (IVC) and inserted into a large hepatic vein. Correct and sufficient wedge position of the catheter is ensured by injecting contrast media while the balloon is blocking the outflow of the cannulated hepatic vein. After calibrating the external pressure transducer, continuous pressure recordings are obtained with triplicate recordings of the wedged hepatic venous pressure (WHVP) and free hepatic venous pressure (FHVP). The difference between FHVP and WHVP is referred to as HVPG, with values &#8805;10 mm Hg indicating clinically significant portal hypertension (CSPH). Before removing the catheter, pressure readings obtained in the IVC at the same level, as well as the right atrial pressure are recorded.
Finally, a transjugular liver biopsy can be obtained via the same vascular route. Different systems are available; however, core biopsy needles are preferred over aspiration needles, especially for cirrhotic livers. Again, under fluoroscopic guidance a biopsy needle introducer sheath is advanced into an hepatic vein. Next, the transjugular biopsy needle is gently advanced through the introducer sheath: (i) in case of aspiration biopsy, the needle is advanced into the liver parenchyma under aspiration and then removed quickly, or (ii) in case of a core biopsy, the cutting-mechanism is triggered inside the parenchyma. Several separate passages can be safely performed to obtain sufficient liver specimens via transjugular biopsy. In experienced hands, the combination of these procedures takes about 30-45 min.

Here, we present a protocol for measurement of hepatic venous pressure gradient (HVPG),the gold standard to diagnose clinically significant portal hypertension. Moreover, we describe how to perform a transjugular liver biopsy within the same session.

肝静脉压梯度和转性肝活检测量

Here we provide a detailed protocol describing the clinical procedure of hepatic venous pressure gradient (HVPG) measurement in patients with advanced ...