急性局灶性脑挫裂伤对大鼠脑微循环及神经组织超微结构的影响

目的:探讨大鼠脑损伤后脑微循环障碍、脑缺血及神经组织超微结构的变化规律,为临床改善脑损伤后脑微循环障碍、治疗脑缺血、促进神经功能恢复提供理论依据。方法:采用Feeney's自由落体撞击法建立急性局灶性脑挫裂伤模型,共81只大鼠,随机均分为9组,每组6只行内源性过氧化物酶(EGPO)组织化学染色、脑含水量测定,并进行图象分析。每组3只电镜观察微血管内皮细胞和神经组织超微结构改变。结果:①脑损伤后30min伤区可见出血灶,伤区内无血管染色,伤区周围存在"微无血管区"。"微无血管区"的存在持续至伤后72h。②脑损伤后30min微血管面密度明显下降,伤后48h达到高峰,直到伤后168h才有所恢复,但仍未达到正常水平。③脑损伤后30 min微血管平均光密度明显下降,伤后24h、48h回升,72h再次下降,至168h仍未恢复正常。④脑损伤后30 min,微血管内皮细胞有轻度受损迹象,伤后2h毛细血管腔内有微绒毛形成,伤后6h微绒毛增多。伤后12~72h毛细血管腔明显狭窄。⑤脑损伤后30min,神经细胞超微结构改变不明显,随时间的延长,神经细胞超微结构逐渐恶化,至伤后168h细胞结构完全丧失。结论:EGPO组织化学染色方法能准确反应脑损伤后脑微循环的改变;脑损伤后即发生脑缺血改变,神经细胞、毛细血管内皮细胞的损害继发于脑损伤后的缺血性改变,而脑缺血的发生源于脑损伤后脑微血管结构的破坏和微循环灌注的不足。     

急性脑损伤脑微循环早期改变的实验研究

目的:研究急性脑损伤早期脑微循环和脑微血管超微结构的改变。方法:采用Feeney's脑落体撞击致伤动物模型,实验动物选用Wistar大鼠,应用内源性过氧化物酶(EPOX)细胞化学示踪微血管。结果:急性脑损伤后2—72小时脑微循环改变的总体特征为“稀”、“细”、“淡”,即伤区及周围血管稀少,管径变细,颜色变淡,提示,脑损伤后早期脑微血管处于高度收缩状态或管腔狭窄、闭塞,血循环减少。结论:脑微循环障碍、脑缺血是继发性脑损害的重要因素,救治重型颅脑损伤要重视防治脑微循环障碍,纠正脑缺血。     

肺内的血管

肺内具有两套血管系统。一套是肺循环血管系统。肺动脉从右心室发出后随支气管经肺门入肺。其分支与支气管树伴行,最后形成包绕于肺泡壁上的毛细血管网。在这里,由于肺泡和呼吸性细支气管内的氧分压比毛细血管的六,而二氧化碳的分压比毛细血管的小,所以氧进入毛细血管,二氧化碳从毛细血管出来,进入肺泡。毛细血管网再逐渐汇合成小静脉,最后汇合成肺静脉,回源至左心房。这套血管系统的功能是进行气体交换作用。另一套血管系统属体循环的一部分,包括支气管动脉、毛细血管网及支气管静脉。支气     

肺内的血管

肺内具有两套血管系统。一套是肺循环血管系统。肺动脉从右心室发出后随支气管经肺门入肺。其分支与交气管树伴行,最后形成包绕于肺泡壁上的毛细血管网。在这里,由于肺泡和呼吸性细支气管内的氧分压比毛细血管的大,而二氧化碳的分压比毛细血管的小,所以氧进入毛细血管,二氧化碳从毛细血管出来,进入肺泡。毛细血管网再逐渐汇合成小静脉,最后汇合成肺静脉,回源至左心房。这套血管系统的功能是进行气体交换作用。另一套血管系统属体循环的一部分,包括支气管动脉、毛细血管网及支气管静脉。支气管动脉起始子胸主动脉或助间动脉,而不是肺动脉,每肺一般有1～3条,较细。入肺后其分支也与支气管树伴行,沿途形成各级毛细血管网。其内流的是动脉血,所以营养着肺内的细     

自闭症谱系障碍儿童早期脑结构发育异常及其神经机制

自闭症谱系障碍是儿童发育早期出现的一种神经发展性疾病。近年来,基于婴幼儿同胞研究范式的脑神经科学研究发现,自闭症儿童发育早期会出现皮层表面积加速增大、脑脊液异常增加和脑白质结构异常,这些发现有助于追踪自闭症儿童大脑和核心行为症状的发育轨迹,预测自闭症早期的发生和后期的发展趋势。本文对自闭症儿童早期脑结构发育异常及其神经机制的研究进行了系统梳理,以期深入理解自闭症的发病机制,助益于自闭症的早期筛查、靶向干预和有效康复。     

神经生长因子治疗WEST综合证疗效分析

本文报告应用种经生长因子(NGF)治疗9例WEST综合征的疗效分析,3个月后判定疗效:7例痉挛发作控制,2例发作频度减少50-75％,脑电图明显改善,1-3年随访结果,原有智能发育障碍者亦大部分发育正常。认为WEST综合征的发生,可能是由于某些原因导致NGF的异常,中枢神经系统缺乏NGF营养保护作用,致使脑内神经介质失衡,脑胆碱能神经元发育阻滞,从而出现精神发育迟滞及痉挛发作。     

幼儿关节扭伤后的护理

幼儿的关节、韧带、骨骼等运动器官尚未发育成熟,发生关节急性扭伤后应及时处理,家园护理甚为重要,可分三个阶段。早期:伤后24～48小时内,应减少活动,同时用冰块、冷毛巾在扭伤部位进行冷敷,并用棉花、海绵来抬高伤肢,也可敷外用药消肿止痛,减轻炎症。此时切勿按摩、热敷。中期:24～48小时以后,炎症消     

昆虫激素

激素是一些化学信息物质,这些化学物质只要少量存在就能引起重大的生理反应,而调节基本的生命活动,昆虫激素基本上可分为两大类:内激素和外激素。内激素或内分泌是由昆虫体内的腺体或组织所产生的化学信息物质,它们被分泌到体液内,借体液流动被带至全身,而对昆虫的生长和发育,起着控制和调节的作用。经过几十年的研究,目前已知对昆虫生长发育起作用的内分泌系统主要包括以下三种器官,即脑中的一群神经分泌细胞,紧位于脑后的小形白色腺体咽侧体,和位于前胸的前胸腺。     

小儿的高热惊厥

高热惊厥是小儿常见疾病,最多见于六个月～三岁的幼儿,因这时期幼儿脑的发育还不够成熟,神经细胞结构简单,脑的兴奋和压抑系统的平衡很不稳定,当体温高至39℃以上时,小儿就会突然全身痉挛,神志丧失,一般时间短暂,大都在半小时内就能恢复,这种现象就称为“惊厥”,一般不会留下后遗症,也不会影响幼儿的生长发育。但大约有三分之一的患儿,多次发作后会造成脑的损害,影响幼儿的发育及智能发展,甚至转化为癲痫,因此值得重视。     

人体门静脉有两处

门静脉和一般静脉不同,一般静脉由许多小静脉会成一主干后,不再进行分支,而门静脉却是两端都有毛细血管的静脉干。 人体门静脉有两处;肝门静脉和脑垂体门静脉,关于肝门静脉在《生物学教学》1993年第11期已有文章介绍,这里仅谈一下垂体门静脉。 垂体呈椭圆形,位于颅腔底部蝶骨鞍内（即颅中窝,交叉前沟后方的垂体窝内）,借漏斗连于下丘,故名脑垂体或脑下垂体,垂体中根据其发生和结构功能特点不同可分为腺垂体、神经垂体两部。腺垂体包括前部、结节部、中间部三部分。神经垂体分后部（神经部）、     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.