实时剪切波弹性成像对乳鼠脑功能影响的研究

发布时间：2018-05-16 22:00

本文选题：超声 + 剪切波弹性成像　；参考：《中国人民解放军医学院》2016年博士论文

【摘要】：目的：剪切波弹性成像技术是目前弹性成像领域的前沿技术,其临床应用范围正在迅速的不断扩大。目前剪切波弹性成像技术已开始应用于新生儿颅脑疾病的诊断,有研究证实该技术具有一定临床诊断价值。但生长发育过程中的中枢神经系统对外界刺激存在敏感性,若这一过程受到干扰,将会给生物体带来严重的后果。因而该技术应用于新生儿颅脑检查是否在安全范围仍有待考证,国内外尚无研究对此进行报道。本课题以新生小鼠为实验对象,首次研究剪切波弹性成像颅脑检查技术对新生哺乳动物脑组织及脑功能的影响,研究内容主要包括以下两个方面：1.采用剪切波弹性成像仪对新生C57乳鼠进行不同时长的照射,并在照射后24小时取脑,观察脑组织形态学变化及信号通路相关蛋白在脑组织中的表达；2.将经过不同时长照射的C57乳鼠饲养至3个月,使用Morris水迷宫检测小鼠的认知功能,并在水迷宫实验后断头取脑,观察脑组织形态学变化及相关蛋白的表达情况。方法：第一部分：将225只出生24小时的新生乳鼠随机分为五组：对照组,5分钟组,10分钟组,20分钟组和30分钟组,并根据相应分组对乳鼠进行不同时长的剪切波弹性成像仪的照射。在接受照射后24小时,每组取10只乳鼠断头取脑,观察脑组织形态学变化和信号通路相关蛋白的表达情况。第二部分：将剩余小鼠饲养至3个月,每组随机挑选15只雄性小鼠,利用Morris水迷宫对小鼠的空间学习记忆能力进行检测,观察并统计逃避潜伏期、穿台次数及目标象限停留时间等指标,并在水迷宫实验24小时内将小鼠断头取脑,观察脑组织形态学变化及信号通路相关蛋白在脑组织中的表达情况。结果：第一部分：根据HE染色和NissI染色的结果,对照组,5分钟组,10分钟组,20分钟组和30分钟组的乳鼠脑组织均未发现明显病理变化。Western-blot检测的结果显示,10分钟,20分钟和30分钟组乳鼠脑组织中的p-PKCa蛋白水平减低,30分钟组乳鼠脑组织中的p-mTOR和p-AKT蛋白水平减低。第二部分：根据Morris水迷宫的实验结果,对照组,5分钟组,10分钟组,20分钟组和30分钟组的小鼠之间逃避潜伏期、穿台次数及目标象限停留时间等指标的差异均无统计学意义。将小鼠断头取脑后,根据HE染色和Nissl染色的结果,各组小鼠脑组织均未发现明显病理改变；Western-blot检测的结果显示,各组小鼠之间脑组织相关通路蛋白的表达水平无明显差异。结论：利用剪切波弹性成像仪对新生乳鼠持续照射30分钟,虽不会引起乳鼠脑组织形态学的改变,但当照射时间持续10分钟时,脑组织中p-PKCa蛋白水平表达减低；持续30分钟时,脑组织中P13K/AKT/mTOR信号通路会受到影响。这种改变随着小鼠的长大会逐渐得到修复,且其空间学习记忆能力与对照组小鼠相比无明显差异,但仍提示生长发育过程中的中枢神经系统对声辐射力脉冲刺激存在敏感性,在利用剪切波弹性成像仪对新生儿颅脑进行检测时,应避免长时间照射。
[Abstract]:Objective: shear wave elastic imaging is the frontier technology in the field of elastic imaging and its clinical application is expanding rapidly. At present, shear wave elastography has been applied to the diagnosis of neonatal craniocerebral diseases. The nervous system is sensitive to external stimuli. If this process is disturbed, it will bring serious consequences to the organism. Therefore, the application of this technique to the safety of newborn brain examination still remains to be examined, and there is no study on it at home and abroad. The effects of brain examination on brain tissue and brain function of newborn mammals were mainly included in the following two aspects: 1. using shear wave elastic imaging apparatus to irradiate newborn C57 rats at the same time, and take the brain for 24 hours after irradiation, and observe the changes of brain histomorphology and signal pathway related proteins in the brain group. The expression in the fabric; 2. the C57 milk rats, which were irradiated with different length of time, were reared for 3 months, and the cognitive function of the mice was detected by the Morris water maze. After the water maze experiment, the brain was cut off, and the changes of the brain histomorphology and the expression of related proteins were observed. Method: the first part: 225 newborn rats were randomly divided into 225 newborn infants, which were born and 24 hours randomly. The five groups: the control group, the 5 minute group, the 10 minute group, the 20 minute group and the 30 minute group, and according to the corresponding group, they were irradiated by the different long shear wave elastic imaging apparatus. 24 hours after receiving the irradiation, 10 milk rats in each group were taken head to take the brain, and the expression of the brain tissue morphologic changes and signal pathway related proteins was observed. Second part. After feeding the remaining mice for 3 months, 15 male mice were randomly selected in each group. The Morris water maze was used to detect the spatial learning and memory ability of the mice. The time of escape latency, the number of times and the time of the target quadrant were counted, and the brain was taken from the head of the mice within 24 hours of the water maze test, and the morphology of the brain was observed. The expression of change and signal pathway related protein in brain tissue. Results: first part: according to the results of HE staining and NissI staining, the control group, 5 minute group, 10 minute group, 20 minute group and 30 minute group of milk rat brain tissues have no obvious pathological changes of.Western-blot detection results, 10 minutes, 20 minutes and 30 minutes group The level of p-PKCa protein in the brain tissue of the rats decreased, and the level of p-mTOR and p-AKT protein in the brain tissue of the rats was reduced in 30 minutes. Second parts: according to the experimental results of the Morris water maze, the control group, the 5 minute group, the 10 minute group, the 20 minute group and the 30 minute group of mice escape the latent period, the times of wearing the platform and the residence time of the target quadrant and so on. There was no significant difference in the standard difference. After taking the head of the mouse, the brain tissue of each group was not found obvious pathological changes according to the results of HE staining and Nissl staining. The results of Western-blot detection showed that there was no significant difference in the expression level of brain related pathway proteins between each group. Conclusion: shear wave elastic imaging is used. The expression of p-PKCa protein in brain tissue decreased when irradiation time lasted for 10 minutes, and the expression of p-PKCa protein in brain tissue was affected by the duration of irradiation for 10 minutes. This change was gradually repaired as the mice grew up. There is no significant difference in spatial learning and memory ability between the control group and the control group, but it still suggests that the central nervous system in the growth and development process is sensitive to acoustic radiation impulse stimulation. The long time exposure should be avoided in the detection of neonatal craniocerebral using shear wave elastic imaging instrument.
【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2016
【分类号】：R742

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