Effect of umbilical cord occlusion on behavior and neurohistology in sheep fetus.

目的：儿童神经功能缺损可归因于产前事件和窒息性损伤。在人类妊娠近，间歇性'可变型'胎心率（FHR）减速被视为在5%，并可能与脐带阻塞（UCO）。目的观察间歇性UCO对胎儿神经组织学的影响。方法：14只孕0.8天的胎羊（实验组，n=7，对照组，n=7）在4天内进行UCO研究，每30分钟完全充气一次（持续90秒），每天3 - 5小时。然后对动物实施安乐死，并制备胎脑用于随后的组织学和髓鞘（SCR）、星形胶质细胞（GFAP）和活化小胶质细胞（HLADR）的免疫染色。脑损伤由神经病理学家根据组织病理学损伤的严重程度和免疫染色的变化进行评分; 0-正常，1-轻微，2-轻度/例 ...更多信息 rly，3-中度至重度/晚期。并以血压和SpO_2为指标，研究了山羊胎儿的循环变化。结果：胎儿血氧分压（PO_2）由24.0±0.5降至6.7±0.8mmHg，PH值由7.36降至7.31。所有实验组均表现为轻微损伤（GFR和/或HLADR染色增加）或轻度损伤（加上皮质缺血神经元）。对照组脑损伤评分为0.4±0.25（P<0.01），实验组为1.6±0.20（P<0.01）。我们推测间歇性UCO可能会引起出生后的神经功能缺损。临床上需要新的技术来检测脑灌注不足。少

Objectives : Neurologic deficit in children can be attributed to prenatal events and asphyxial insults. In human pregnancies near term, intermittent 'variable type' fetal heart rate (FHR) decelerations are seen in 5% and can be associated with umbilical cord occlusion (UCO). Effect of intermittent UCO on neurohistology in fetus is determined. Clinical detection for hypo-perfusion of the fetal brain is also investigatedMethods : 14 chronically instrumented fetal sheep (experimental, n=7, Control, n=7) at 0.8 gestation were studied over 4 days with UCOs by complete inflation of an occluder cuff (duration 90 seconds) every 30 minutes for 3 to 5 hours each day. Animals were then euthanized and the fetal brains were prepared for subsequent histology and immunostaining for myelin(SCR), astrocytes(GFAP), and activated microglia(HLADR). Brain injury was scored by a neuropathologist, based on the severity of injury by histopathology and changes in immunostaining ; 0-normal, 1-minimal, 2-mild/ea … More rly, 3-moderate to severe/advanced. We also studied the circulatory change by using blood pressure and SpO_2 charges in goat fetus. These experiments were conducted in the Department of Veterinary Medicine of Kagoshima University and Department of Obstetrics and Gynecology of Western Ontario University, Canada.Results : Fetal PO_2 decreased from 24.0±0.5 to 6.7±0.8mmHg whereas change of PH was from 7.36 to 7.31. All the experiment group showed minimal injury (increased staining of GFR and/or HLADR) or mild injury (plus in ischemic neurons in cortex). Brain injury score for controls was significantly lower, averaging 0.4±0.25(p<0.01) with one animals having minimal injury and 1.6±0.20 in experimental group.Conclusions : We conclude that intermittent UCO can result in neuropathological change in the cortical and subcortical white and gray matters. We speculate that intermittent UCO may give rise to postnatal neurologic deficit. New technique to detect brain hypo-perfusion is required in clinical settings. Less