Abnormalities of the foetal cerebral cortex

Prenatal ultrasound has concentrated on readily visible cerebral structures including head size, shape, ventricles, CSP (cavum septi pellucidi), cerebellar size/vermian presence and cisterna magna. However, apart from these easily visible structures it is important to evaluate the brain itself. Patients who initially appear to have mild isolated findings such as borderline ventriculomegaly in fact can have many more subtle findings that significantly alter prognosis and management that can be detected on detailed examination of the brain. There has been rapid evolution in imaging these foetuses, especially with neurosonography and MRI, and a revolution in understanding the underlying genetic and biochemical mechanisms. There is increasing emphasis to detect cortical abnormalities as early as possible. This article reviews development of the cerebral cortex, the classification, aetiologies and clinical manifestations of cortical disorders, normal and abnormal appearances at ultrasound and MRI, and approaches to investigation. Copyright © 2009 John Wiley & Sons, Ltd.     

高氯酸钠对斑马鱼胚胎的毒性效应

采用斑马鱼胚胎发育技术方法研究高氯酸钠对斑马鱼胚胎的急性毒性效应,配制一系列高氯酸钠的浓度,对受精1h的胚胎进行染毒暴露,最后对斑马鱼胚胎的心率,孵化率,死亡率,畸形率进行统计分析。研究结果显示,高氯酸钠(NaClO4)浓度的增加,斑马鱼胚胎的心率和孵化率降低、死亡率和畸形率增加。斑马鱼48hpf的胚胎心率高浓度组比对照组下降了35%;72 h的孵化率由对照组的88%降低到高浓度组的36%;144 h的死亡率由对照组的5%增加到72%;144 h的畸形率由对照组的2%增加到91%,主要畸形表现为心包囊肿(PE),脊柱弯曲(AM),鱼鳔缺失(SBD)等。结果表明,高浓度的高氯酸钠(NaClO4)对斑马鱼胚胎发育有明显的剂量效应作用。