Ultrasonic Measurement of Islet Volume

胰岛体积的超声波测量

• 批准号: 7122193
• 负责人: Steven Allen Africk
• 金额: $ 4.4万
• 依托单位: PRODYNE CORPORATION
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7122193
• 关键词: cell morphology; cell population study; method development; morphometry; oxygen consumption; pancreatic islet function; pancreatic islets; swine; tissue /cell preparation

DESCRIPTION (provided by applicant): The main goal of this project is to develop a novel in vitro technique for measurement of total cell volume in samples of islets of Langerhans that will be useful for assessing the quality of islet preparations for pancreatic transplantation and research. DNA content is currently used as a measure of total cell volume. It has been proposed that the quality of islet preparations can be represented by the ratio of viable to total cell volume, which is related to the ratio of oxygen consumption rate (OCR) to DNA content, currently determined separately. The new method will replace DNA measurement and will be useful in several applications: (1) in a small, stand alone device useful with small aliquots, {2) in a small device capable of simultaneous measurement of both OCR and total cell volume in the same container, and (3) in a configuration useful for assay of a large islet preparation. The method will provide an estimate of total cell volume with greater accuracy, rapidity and convenience than is now possible. The technology, known as Ultrasonic Streaming Pulsed Doppler (USPD), measures the reflectivity of suspended cells from which total volume is inferred by use of a calibration curve. The method also induces flow and the reflections occur at frequencies below that of the incident energy making return signals much easier to detect than would be possible in still fluids. This flow may also provide necessary mixing and eliminate the need for a stirrer. The primary aim in Phase I will be to developed the fundamental calibrated relationship between islet total volume and reflectivity that will be the basis of the methodology. This will be developed with a series of reflectivity experiments with polystyrene micro spheres and rat and porcine islets. Other aims are to determine regimes of operational parameters in which the method can operate without damage to islets, to design transducers that can operate through container walls and to determine the practicality of using the streaming flows to provide mixing. The technique will be demonstrated with samples of islets in very small test vessels and with larger islet preparation samples prior to transplantation. The major goals for Phase II will be demonstration of the technology with human islets and development of diagnostic devices for commercial application. The technique will have other applications in medicine and bioprocessing wherever information on cell concentration is required rapidly.

描述(申请人提供)：本项目的主要目标是开发一种新的体外技术来测量朗格汉斯胰岛样本中的总细胞体积，这将有助于评估胰腺移植和研究的胰岛制剂的质量。DNA含量目前被用作衡量细胞总体积的指标。有人提出，胰岛制剂的质量可以用活细胞体积与总细胞体积的比率来表示，这与目前单独测定的耗氧率(OCR)与DNA含量的比率有关。新方法将取代DNA测量，并将在几个应用中有用：(1)用于小等分的小型独立设备，{2)能够同时测量同一容器中的OCR和总细胞体积的小型设备，以及(3)用于分析大的胰岛制剂的配置。该方法将提供比现在可能的更准确、快速和方便的总细胞体积的估计。这项技术被称为超声流脉冲多普勒(USPD)，它测量悬浮细胞的反射率，通过使用校准曲线来推断总体积。这种方法还会产生流动，反射的频率低于入射能量的频率，使得返回信号比在静止流体中更容易检测到。这种流动还可以提供必要的混合并消除对搅拌器的需要。第一阶段的主要目标将是建立胰岛总体积和反射率之间的基本校准关系，这将是该方法的基础。这将通过一系列聚苯乙烯微球以及大鼠和猪胰岛的反射率实验来发展。其他目的是确定该方法可以在不损害胰岛的情况下操作的操作参数的范围，设计可以通过容器壁操作的换能器，并确定使用流动提供混合的可行性。这项技术将在移植前用非常小的测试血管中的胰岛样本和较大的胰岛制备样本进行演示。第二阶段的主要目标将是演示人类胰岛技术，并开发用于商业应用的诊断设备。这项技术将在医学和生物处理领域有其他应用，这些领域需要迅速获得细胞浓度信息。