Biomagnetic Signals of Intestinal Ischemia

描述(由申请人提供)： 肠缺血，无论是由栓子、血栓形成还是绞窄性梗阻引起的，仍然是一种严重的和潜在的致命疾病。我们率先使用超导量子干涉装置(SQUID)磁强计在体外以及动物和人类受试者中记录胃肠道平滑肌活动。这种非侵入性、非接触式的平滑肌生物磁电流测量方法证明了使用SQUIDs研究人体肠道平滑肌生理学的可行性。与皮肤电极记录肠道电活动相比，鱿鱼具有独特的基本优势，因为磁场很容易穿透脂肪层，而电场不能，而且无法常规获得人体小肠的皮肤电极记录。鱿鱼代表了一种引人注目的新诊断设备，除了侵入性手术和在肠道表面放置电极外，没有其他同类设备。假设1：肠系膜缺血引起肠平滑肌解偶联和心律失常，可在外部记录的磁场中检测到。我们将开发模型来解释心律失常、解偶联以及介入组织对外部记录磁场的影响。基于我们对缺血期间平滑肌行为的了解，将开发先进的分析技术来区分缺血肠和正常信号。我们将首次对手术探查过程中和手术后记录中的磁流进行表征。假设w：肠系膜缺血导致受影响的平滑肌细胞持续极化，导致在外部记录的磁场中可检测到的损伤电流。损伤电流以前已经在心脏动物和人类的研究中被证明存在并且可以被磁性地检测到，以检测这一现象。作为SBIR拨款(NIH R44 DK49435-2)的一部分，专门为研究人类肠道磁场而开发和建造的新多通道鱿鱼将可供使用，并将首次为我们提供一个非同寻常的机会，探索肠缺血期间的平滑肌病理生理学-人类已知的最致命的疾病之一。

DESCRIPTION (provided by applicant): Intestinal ischemia whether resulting from emboli, thrombosis or strangulation obstruction continues to be a serious and potentially fatal condition. We have pioneered the use of Superconducting Quantum Interference Device (SQUID) magnetometers for biomagnetic recordings of gastrointestinal smooth muscle activity in vitro, and in both animal and human subjects. This non-invasive, non-contact measurement of biomagnetic currents in smooth muscle demonstrates the feasibility of using SQUIDs to investigate human intestinal smooth muscle physiology. SQUIDs have unique fundamental advantages over cutaneous electrode recordings of intestinal electrical activity because magnetic fields readily penetrate layers of fat while electrical fields do not and cutaneous electrode recordings of human small bowel can not be routinely obtained. SQUIDs represent a striking new diagnostic device that has no equivalent except for invasive surgery and placement of electrodes onto the bowel surface. Hypothesis 1: Mesenteric ischemia causes uncoupling and arrhythmias of intestinal smooth muscle detectable in externally recorded magnetic fields. We will develop models to explain the arrhythmias, uncoupling and the effects of intervening tissue on the externally recording magnetic fields. Advanced analysis techniques to discriminate ischemic bowel from normal signals will be developed base upon our knowledge of smooth muscle behavior during ischemia. We will characterize for the fist time the magnetic currents in recordings taken during and after surgical exploration. Hypothesis w: Mesenteric ischemia causes sustained polarization of affected smooth muscle cells resulting in injury currents detectable in the externally recorded magnetic fields. Injury currents have been previously demonstrated to occur and be detectable magnetically in cardiac animal and human studies to detect this phenomenon. The new multichanel SQUID specifically designed for study of human intestinal magnetic fields developed and built as part of a SBIR grant (NIH R44 DK49435-2) will be available for use and will give us an extraordinary opportunity for the first time to explore smooth muscle pathophysiology during intestinal ischemia-one of the most deadly diseases known to man.