VEGF在实验性脑积水大鼠脑组织中的表达

目的 探讨血管内皮生长因子（VEGF）在脑积水后脑组织中的表达状况。方法 雄性Wistar大鼠60只，随机分为实验组和对照组，其中实验组48只，再随机平均分为A、B、C、D四个亚组，应用显微外科技术向枕大池内注入25％白陶土混悬液0．1ml，分别在白陶土注射后第1、2、4、6周行MRI检查，获取鼠脑冠状切面的T2图象，鉴定脑积水是否形成。之后24h内处死动物并迅速取脑组织，应用免疫组织化学方法分别测定各组大鼠脑组织不同部位VEGF表达情况。其余12只用同样方法向枕大池内注入生理盐水作为对照组。结果 34只大鼠成功诱发脑积水。与对照组相比，实验组脑组织中VEGF表达均明显升高，尤其是脑室周围白质更为明显。结论 VEGF可能参与脑积水的病理损害和恢复过程。     

脑积水对脑室周围神经干细胞影响的实验研究

目的探讨脑积水对大鼠脑室周围神经干细胞影响。方法6wWistar大鼠70只，随机分为实验组35只，对照组35只，应用显微外科技术向枕大池内注入25％无菌高岭土混悬液0．05ml，分别在高岭土注射后3d，1w，2w，3w，4w处死动物，迅速取脑组织，测侧脑室指数，用免疫组织化学方法动态检测脑室周围Nestin阳性细胞的表达，同样方法向枕大池内注入生理盐水作为对照组。结果实验组28只大鼠成功诱发脑积水并完成实验全过程，对照组30只完成实验全过程。对照组大鼠各对应时间点，侧脑室指数基本相同，实验组大鼠脑室进行性扩大；脑室周围Nestin阳性细胞：对照组细胞数平均193±20．3个并维持，脑积水造模后3d达到最大值，为对照组308％±1％（P〈0．001），1w脑室周围Nestin阳性细胞下降到对照组196％±1％，2w降到对照组水平210±22．4个，3w脑室周围Nestin阳性细胞几乎看不到并持续。结论脑积水引起脑室进行性扩大，脑室周围神经干细胞可能受脑室扩张机械性压迫引起缺血，缺氧影响，参与脑积水病理损害和修复过程。     

实验性脑积水大鼠脑中iNOS的表达及脑脊液中NO含量变化

一、材料与方法 50只Wistar大鼠（体重200～250g）随机分为实验组和对照组，实验组40只再平分为A、B、C、D四个亚组。每只大鼠腹腔麻醉后在手术显微镜下暴露寰枕膜，用4．5号注射针头穿刺枕大池，抽出脑脊液80μl-0．1ml后，缓慢注入25％白陶土混悬液0．1ml，用耳脑胶封闭针眼，缝合切口，麻醉清醒后放回鼠笼中喂养，各亚组分别于白陶土注射后第1周（A组）、2周（B组）、4周（C组）、6周（D组）在中科院武汉物理研究所应用Bruker Biospec 47／30磁共振谱仪行MRI检测，获取鼠脑冠状切面的他图象；对照组大鼠用同样方法抽脑脊液后经枕大池注入生理盐水，2周后行MRI检测。     

实验性脑积水幼鼠脑脊液中一氧化氮及谷氨酸浓度的变化

目的探讨实验性脑积水幼鼠脑脊液中一氧化氮（NO）和谷氨酸（Glu）浓度的动态变化。方法SD幼鼠40只,随机平分为A、B、C实验组和对照组共4组,用显微外科技术向枕大池内注入25%白陶土混悬液,分别在注射后第2（A组）、3（B组）、4周（C组）后行MRI检测,鉴定脑积水形成情况;之后24h内取脑脊液,用硝酸还原酶法测NO浓度、高效液相色谱仪检测Glu浓度。对照组幼鼠于枕大池内注入生理盐水,用同样方法检测。结果实验组21只幼鼠成功诱发脑积水。与对照组相比,实验组脑脊液中NO和Glu浓度显著增加（P〈0.01）。结论脑脊液中高水平的NO和Glu可能参与了实验性脑积水幼鼠的病理损伤过程。     

高岭土诱导大鼠脑积水模型的建立和监测

目的 高岭土诱导Wistar大鼠脑积水后系统监测大鼠体质量、颅内压、脑室面积和胼胝体厚度的改变.方法 雄性Wistar大鼠60只,按随机数字表顺序分为实验组(n＝40)和对照组(n=20).实验组40只大鼠再随机分为A、B、C、D、E五个亚组,向枕大池内注入25％无菌高岭土混悬液0.1 ml;对照组注入等量无菌生理盐水,注入后3d、1周、2周、4周和8周后行体质量、MRI检查及颅内压监测,经视交叉切片测量胼胝体厚度.结果 实验组共有23只大鼠脑室不同程度的扩大,侧脑室随时间延长逐渐扩大;脑积水大鼠体质量明显低于对照组;颅内压在高岭土注入后3d明显增高,7d左右达峰值,8周时颅内压有所下降,但仍明显高于正常值;胼胝体厚度随脑室扩张逐渐变薄.结论 高岭土注入枕大池可成功诱导建立大鼠交通性脑积水模型,脑积水后大鼠体质量、颅内压、脑室扩张和胼胝体厚度呈一系列连续的变化,不同时间窗各有特点.     

犬脑积水模型的建立与评估

目的对比两种方法建立犬脑积水模型并进行评估。方法选取40只成年犬随机分为实验组、对照组,实验组使用硅油注入第四脑室,对照组使用白陶土注入第四脑室,术前、术后均行头部CT检查确认。结果实验组成功获得脑积水模型15例(75%),对照组成功获得脑积水模型8例(40%),两组成功率差异有统计学意义(P0.05)。结论经枕大池穿刺注射硅油建立的脑积水模型简便易行、重复性和稳定性好,适用于脑积水的实验研究。     

米诺环素对脑积水大鼠星形细胞增生的影响

目的 研究米诺环素对脑积水大鼠星形细胞增生的影响.方法 成年雄性SD大鼠100只,应用显微外科技术向枕大池内注入25％无菌高岭土混悬液0.1ml诱导脑积水.取75只造模成功大鼠随机分为实验组和对照组,实验组再分为5个亚组(3、7、14、21、28 d),每个亚组10只,配对对照组5只大鼠.分别于术后3、7、14、21和28 d行MRI检查.实验组给予米诺环素,对照组给予等量生理盐水.Morris水迷宫实验后取脑组织行苏木精-伊红染色、胶质纤维酸性蛋白(GFAP)免疫组化检查.结果 不同时间组脑积水大鼠室周白质和海马中均出现GFAP阳性星形细胞.实验组脑积水大鼠GFAP阳性星形细胞数目明显少于对照组(均P ＜0.01).两组Morris水迷宫实验差异无统计学意义(P＞0.05).结论 米诺环素对脑积水大鼠室周白质和海马星形细胞活化增生具有抑制作用.     

大鼠实验性脑室出血后水通道蛋白1在脑内的表达及意义

目的 观察大鼠脑室出血后水通道蛋白1(AQP1)在大鼠脑内的表达变化,探讨其与脑出血后慢性脑积水之间的关系. 方法 将45只Wister大鼠按照随机数字表法分为3组:正常对照组(5只,不作任何处理)、假手术对照组(20只,侧脑室内注入0.1 mL生理盐水)、实验组(20只,侧脑室内注入0.1 mL枸橼酸化的自体静脉血),后2组再分别分为术后3 d、7 d、14 d、30 d4个时相点,每时相点5只.分别采用免疫组化、原位杂交方法观察大鼠脑室出血后不同时间AOP1蛋白及AQP1 mRNA在大鼠脑内的表达变化. 结果 实验组30 d时相点4只大鼠出现脑积水(4/5)、其余组别未出现慢性脑积水.正常对照组大鼠AQP1蛋白在脉络丛上皮细胞顶质膜强烈表达,室管膜、纵裂池、软脑膜、蛛网膜、硬脑膜也有较强烈表达;实验组大鼠脑室出血后3 dAQP1蛋白表达减少,7 d表达继续减少,14 d表达最弱,与正常对照组、假手术对照组比较,差异均有统计学意义(P<0.05),30d表达仍较弱.大鼠AQP1 mRNA在脑内的表达强度较AQP1蛋白弱,表达部位及变化与AQP1蛋白基本一致. 结论 AQP1作为水通道蛋白不仅参与脑脊液的分泌,可能也参与脑脊液的循环吸收过程;大鼠实验性脑室出血后AQP1表达下调导致脑脊液吸收减少可能也参与脑出血后慢性脑积水的形成.     

大鼠实验性脑室出血后LN及LNR-1在脑内的表达及意义

目的观察大鼠脑室出血后层粘蛋白（LN）及其受体LNR-1在大鼠脑内的表达变化，探讨其与出血后慢性脑积水之间的关系。方法将大鼠随机分为3组：正常对照组、假手术对照组、实验组，将枸橼酸化的0．1ml自体静脉血注入实验组大鼠侧脑室内建立出血后慢性脑积水模型（假手术组注入0．1ml生理盐水），采用免疫组化方法观察出血后不同时间LN及LNR-1在脑内的表达变化。结果实验组30d出现脑积水为80％（4／5）、其余组别未出现慢性脑积水；实验组出血后LN在纵裂池、软脑膜、蛛网膜、硬膜、脑内毛细血管壁、蛛网膜下腔血管壁的表达在3d时增加，7d表达继续增加，14d表达最强，较对照组、假手术组显著增强（P〈0．01），30d仍强烈表达；实验组出血后LNR-1在脉络丛的立方上皮细胞胞浆及顶质膜、室管膜细胞、软脑膜细胞、蛛网膜细胞、硬膜、纵裂池、胶质细胞的表达增加。LNR-1在蛛网膜下腔的表达变化与LN基本一致。结论大鼠脑室出血后LN及LNR-1的表达上调可能参与蛛网膜纤维化的过程，从而在出血后慢性脑积水的形成中发挥重要作用。     

犬脑积水后轴索损伤的神经微丝免疫组化研究

目的探讨脑积水后大脑半球白质内轴索损伤的特点及意义.方法20只成年雄性犬通过枕大池穿刺注射白陶土的方法建立脑积水模型,按处死时间分为3 d组、2周组、8周组及对照组,每组5只.观察实验犬的行为及神经功能,并通过神经微丝免疫组化染色研究大脑半球白质内轴索的变化,同时观察轴索骨架系统超微结构改变.结果各实验组实验犬均有不同程度的行为学改变,但明显的神经功能障碍仅出现于脑积水诱导8周后;白质内轴索在3 d组即有损害发生,并随病程进展而进行性加重,在3 d组和2周组限于脑室周围,8周组则范围扩大,累及皮层下区域.结论轴索损伤贯穿于脑积水的早中晚期,其损害程度和范围与神经功能障碍密切相关.     

一种实验性脊髓空洞前状态动物模型的建立

目的:建立一种新西兰兔脊髓空洞前状态动物模型。方法:新西兰兔64只,随机分为Kaolin组、生理盐水组和假手术组,其中Kaolin组48只,经皮枕大池穿刺注入25%Kaolin混悬液0.6ml,分别于Kaolin注射后第1d、3d、7d、14d、21d、28d后常规行MRI观察后处死,取出上颈髓行组织学观察。结果:Kaolin组动物自Kaolin注入后3d出现缺血水肿(72.78±0.88%),7～14d达高峰(72.94±0.64%),21d减轻(70.21±0.49%);在T1WI表现为略低信号,T2WI为高信号且不能为FLAIR序列所抑制。至28d动物出现上颈髓空洞。结论:经皮枕大池Kaolin注射法可以制作出一种稳定性好、可重复率高的脊髓空洞前状态动物模型。     

A new experimental model of obstructive hydrocephalus in the rat: the micro-balloon technique

We used three types of specialized micro-balloons 0.7–1.35 mm in outer diameter instead of kaolin to develop a reproducible rat model of hydrocephalus with a low experimental mortality. The micro-balloon was inserted 6 mm deep into the cisterna magna via a burr hole immediately behind the lambda. The angle of introduction was 50°. We also set up kaolin-induced hydrocephalic models in 25 rats as controls. The kaolin model revealed 52% mortality with an 80% induction rate of hydrocephalus, while the balloon model showed 9% mortality with a 60% induction rate. Balloon-induced hydrocephalus was maximal at 1 week and tended to decrease after 2–3 weeks. The pathological findings were not different between the two models. We concluded that the micro-balloon model for hydrocephalus is an easily reproducible model with low experimental mortality. Received: 2 March 1998 Revised: 21 July 1998     

“Hydrocephalus-parkinsonism complex”: progressive hydrocephalus as a factor affecting extrapyramidal tract disorder—an experimental study

Objective To experimentally clarify the symptomatological and pathophysiological aspects of a newly proposed clinical entity, we produced an experimental rat hydrocephalus-parkinsonism complex model.Methods A total of 60 male Sprague-Dawley rats were used. Twenty rats were treated with only kaolin as controls. Hemiparkinsonism was induced in the other 40 rats by stereotactic injection of 6-hydroxydopamine (6-OHDA) directly into the right substantia nigra. Twenty of these 40 rats were then treated with an injection of kaolin into the cisterna magna 3 days after the induction of parkinsonism. Neurological features were assessed weekly for 1 to 6 weeks after 6-OHDA injection by an apomorphine-induced turning test.Results The mortality rate was 25% in the rats injected with kaolin and 10% in those with the 6-OHDA injection. The frequency of the induction of parkinsonism-like signs was minimal in the first 2 weeks and reached a maximum point 4 weeks after the 6-OHDA injection. In contrast, the rats injected with both 6-OHDA and kaolin developed hemiparkinsonism-like signs in the early stage of the progression of hydrocephalus, and the peak incidence was reached in the 2nd week after induction (p<0.05 compared with the 6-OHDA group). The severity of the neurological disturbance was also significantly more prominent in the latter group.Conclusion These results suggest that the hydrodynamic effect in the early period of ventriculomegaly is the mechanism for signs of parkinsonism in 6-OHDA-treated rats. It could be concluded that the hydrocephalic state aggravates parkinsonism, if any as the associated condition, and it may be a new clinical entity of hydrocephalus symptomatology with a specific pathophysiology.An erratum to this article can be found at     

Axonal damage associated with enlargement of ventricles during hydrocephalus: a silver impregnation study

Motor and cognitive deficits are commonly associated with hydrocephalus. Although the mechanisms responsible for these impairments have not been confirmed, neuronal cell death and axon degeneration may play an important role, and have long lasting consequences on neuronal connectivity. The goal of this study was to determine if neural degeneration occurred during hydrocephalus in structures anatomically related to cognitive motor functioning, namely, the sensorimotor cortex, neostriatum, hippocampus and corpus callosum. Neural damage, as visualized by silver staining, was examined in adult rats 2-10 weeks after obstructive hydrocephalus was induced by kaolin injection into the cisterna magna. In mild or moderate hydrocephalus, mostly occurring 2-6 weeks after kaolin injections, silver-labeled axons were scattered in the white matter of the sensorimotor cortex, corpus callosum, neostriatum, and hippocampus. In severe hydrocephalus, 10 weeks after kaolin injections, axon degeneration was more extensive in these areas, as well as in layers IV through VI of the sensorimotor cortex. Axons in the subiculum and the fimbria were heavily labeled, suggesting damage to hippocampal afferent and efferent fibers. In contrast, neuron cell death was rarely observed at any stage of hydrocephalus. The major pathological change of brain regions involved in motor and learning functions during hydrocephalus is axon degeneration, and this degeneration is correlated with an enlargement of the cerebral ventricles.     

Axonal damage associated with enlargement of ventricles during hydrocephalus: A silver impregnation study

Abstract

Motor and cognitive deficits are commonly associated with hydrocephalus. Although the mechanisms responsible for these impairments have not been confirmed, neuronal cell death and axon degeneration may play an important role, and have long lasting consequences on neuronal connectivity. The goal of this study was to determine if neural degeneration occurred during hydrocephalus in structures anatomically related to cognitive motor functioning, namely, the sensorimotor cortex, neostriatum, hippocampus and corpus callosum. Neural damage, as visualized by silver staining, was examined in adult rats 2–10 weeks after obstructive hydrocephalus was induced by kaolin injection into the cisterna magna. In mild or moderate hydrocephalus, mostly occurring 2–6 weeks after kaolin injections, silver-labeled axons were scattered in the white matter of the sensorimotor cortex, corpus callosum, neostriatum, and hippocampus. In severe hydrocephalus, 10 weeks after kaolin injections, axon degeneration was more extensive in these areas, as well as in layers IV through VI of the sensorimotor cortex. Axons in the subiculum and the fimbria were heavily labeled, suggesting damage to hippocampal afferent and efferent fibers. In contrast, neuron cell death was rarely observed at any stage of hydrocephalus. The major pathological change of brain regions involved in motor and learning functions during hydrocephalus is axon degeneration, and this degeneration is correlated with an enlargement of the cerebral ventricles. [Neurol Res 2001; 23: 581-587]     

Alterations in brain metabolism, CNS morphology and CSF dynamics in adult rats with kaolin-induced hydrocephalus

The present study describes the biochemical changes, morphological development and the cerebrospinal fluid dynamics of the kaolin-induced hydrocephalus in the adult rat. Two, 4 and 6 weeks after microsurgical kaolin instillation into the rat cisterna magna the basal intracranial pressure and the cerebrospinal fluid outflow resistance were measured. To determine possible biochemical changes in the rat cerebrum, brain stem and cerebellum the concentrations of glutamine, glutamate, glutathione, aspartate, GABA, alanine and taurine were measured by high pressure liquid chromatography. In addition, ventriculomegaly and syringomyelia were assessed, measuring the lateral ventricles and central canals by means of an image-processing computer program. It could be shown that the acute phase of kaolin-induced hydrocephalus in the first 4 weeks is characterised by a high basal intracranial pressure, a considerably increased CSF outflow resistance and a rise in brain water content in the fourth week. The changes in the concentrations of amino acids were moderate. Glutamine was increased and taurine was decreased in the cerebrum and alanine was increased in the brain stem. The chronic phase, however, is defined by normal basal pressure, declining outflow resistance, progression of ventriculomegaly and distinct changes in the biochemical parameters such as a remarkable decrease of glutamate, glutamine and taurine in the cerebellum, a decrease of taurine and alanine plus an increase in glutamine in the cerebrum and an increase of alanine in the brain stem. Moreover, cerebral metabolism in the adult rat seems to be more resistant to the effects of hydrocephalus than metabolism in neonatal and infantile rats.