牛磺酸对宫内生长受限新生大鼠大脑Bcl-2,Bax和Caspase-3蛋白表达的影响

目的 探讨牛磺酸对宫内生长受限(IUGR)新生大鼠大脑皮质Bcl-2、Bax和Caspase-3蛋白表达的影响.方法 将15只孕鼠随机分为3组:正常对照组(正常组)、IUGR模型组(IUGR组)、牛磺酸治疗组(牛磺酸组)(n=5).IUGR模型组孕鼠自受孕第1天始饲以正常组40%的进食量(10 g/d)制备IUGR模型,牛磺酸组在开始建立IUGR模型第12天喂服牛磺酸300 mg/(kg·d),直至自然分娩.每窝新生大鼠随机抽取2只,采用免疫组织化学方法检测各组仔鼠大脑Bcl-2、Bax和Caspase-3蛋白的表达.应用SPSS 10.0软件进行统计学分析.结果 与正常组相比,IUGR组新生大鼠大脑皮质Bcl-2阳性细胞数减少,Bax和Caspase-3阳性细胞数增多,Bcl-2/Bax显著降低,差异均具有统计学意义(Pa<0.05).与IUGR组比较,牛磺酸组Bcl-2阳性细胞数增加,Bax和Caspase-3阳性细胞数下降,Bcl-2/Bax增高,差异均具有统计学意义(Pa<0.05).牛磺酸组与正常组新生大鼠大脑皮质,Bcl-2、Bax和Caspase-3阳性细胞数比较差异均具有统计学意义(Pa<0.05).结论 牛磺酸可通过上调Bcl-2的表达,下渊Bax和Caspase-3的表达,抑制神经细胞的凋亡,对IUGR幼鼠脑组织起到保护作用.     

大麻素受体1及神经黏附分子L1在宫内发育迟缓大鼠脑组织的表达

目的 通过孕期低蛋白饮食的方法建立宫内发育迟缓(IUGR)动物模型,观察大麻素受体1(CB1)及神经黏附分子L1(NCAM-L1)在IUGR及正常大鼠脑不同发育阶段的表达,探讨IUGR大鼠脑发育迟缓的发生机制.方法 将32只孕鼠随机分成正常饮食组和低蛋白饮食组(每组16只),采用孕期全程低蛋白饮食方法建立IUGR大鼠模型.所有新生鼠按出生体质量分为IUGR组及正常对照组.随机于出生0、7、14、21d断头取脑,称取脑质量,免疫组织化学方法检测2组新生鼠脑组织中CB1及NCAM-L1的表达情况.采用Image-Pro Plus 5.1图像处理软件进行半定量分析,计算CB1及NCAM-L1阳性细胞的累积吸光度.结果 新生鼠脑内CB1及NCAM-L1的表达区域基本相同,二者表达量的变化与脑质量变化一致;与正常对照组比较IUGR组幼鼠0d、7d、14 d、21 d脑组织CB1的表达显著降低,NCAM-L1表达显著升高,差异均有统计学意义(P均＜0.05),且2组CB1表达与NCAM-L1表达均呈负相关(P=0.032,0.010).结论 CB1及NCAM-L1参与大鼠脑发育过程;CB1对大鼠脑发育的影响可能通过NCAM-L1实现.     

脑源性神经营养因子对缺氧缺血胚鼠脑细胞凋亡的作用

目的探讨外源性脑源性神经营养因(BDNF)在宫内缺氧缺血环境下对胚鼠脑神经细胞凋亡的作用及其可能信号传导途径。方法 钳夹孕鼠子宫动脉30 min后,实验组经孕鼠尾静脉注射2 μg BDNF,对照组注入生理盐水、Tunel法测定各组脑组织神经细胞凋亡,免疫组织化学分析不同时间点胞外信号调节酶(ERK),c-Jun氨基末端激酶(JNK)表达情况。结果随缺血再灌注时间延长,胚脑凋亡细胞逐渐增多。实验组胚脑组织同时间点神经细胞凋亡数较对照组少,ERK表达较对照组增强,JNK表达成弱。结论BDNF在宫内缺氧缺血环境下有减少胚脑神经细胞凋亡作用,该作用可能与激活ERK信号途径有关。     

反复高热惊厥大鼠脑源性神经营养因子表达的意义

目的 探讨大鼠反复高热惊厥(FS)后脑源性神经营养因子(BDNF)的变化.方法 雄性SD大鼠51只随机分为健康对照组(NC组,n=14),高热对照组(HC组,n=19)和FS组(n=18),热水浴法建立FS模型.酶联免疫吸附试验(ELISA)测定各组海马匀浆BDNF水平,免疫组织化学法检测BDNF在大鼠脑组织各区的表达,原位末端标记法(TUNEL)检测大鼠脑组织细胞凋亡,采用SPSS 13.0软件进行统计学分析.结果 ELISA法测得的FS组海马BDNF水平(89.90±12.51)ng/g明显高于NC组(54.43±18.92)ng/g和HC组(64.09±15.03)ng/g(Pa<0.01),FS组大鼠各脑区BDNF阳性神经元A值亦明显高于NC和HC组(Pa<0.01);FS组分析各Ⅸ凋亡指数(AI)均明显高于NC与HC组(Pa<0.01),各区AI从高到低依次为海马齿状回(DG)区(32.65±2.14)%、CA3区(28.99±1.16)%、CAI区(24.28±0.92)%、颞叶皮层(CTL)(22.19±1.06)%,且原位末端标记法染色观察脑组织各区细胞凋亡程度与BDNF在脑组织各区的表达特点呈正相关(r=0.332 P<0.05).结论 反复FS后大鼠脑内BDNF表达明显增加,并且与神经细胞的凋亡程度相关.     

建立大鼠宫内生长迟缓模型的方法

建立大鼠宫内生长迟缓模型在研究宫内生长迟缓 (IUGR)发生机制、疾病发生过程及病理改变起着重要作用。目前造模的方法有孕期营养干预法、子宫动脉结扎法、被动吸烟法、更生霉素药物法、低氧吸入法等 ,营养干预法、子宫动脉结扎法是最常用的。不同方法的难度不一样 ,效果也不同。由于即使同一种方法、同一种大鼠 ,其仔鼠的出生体质量也有很大的差异 ,因此均采用低于对照组出生体质量减 2倍标准差作为判断试验组仔鼠是否是IUGR的条件。     

孕酮干预缺氧缺血性脑损伤新生大鼠海马葡萄糖转运蛋白1、3基因的表达

目的 观察孕酮干预缺氧缺血新生大鼠海马葡萄糖转运蛋白基因(GLUT1 mRNA和GLUT3 mRNA)的表达变化,探讨孕酮对缺氧缺血性脑损伤的影响.方法 7日龄SD大鼠40只,随机分成4组:正常组、假手术组、缺氧缺血组和孕酮组.缺氧缺血组及孕酮组新生大鼠先行右侧颈总动脉结扎术,再吸入80 mL/L氧气和920 mL/L氮气混合气体2 h,建立缺氧缺血动物模型;孕酮组于建立模型前30 min按8 mg/kg腹腔注射孕酮溶液.假手术组新生大鼠仅作右侧颈总动脉分离.缺氧缺血后24 h,各组新生大鼠断头处死,取脑海马组织,提取总RNA,采用反转录-聚合酶链反应(RT-PCR)检测海马GLUT1 mRNA和GLUT3 mRNA的表达.结果 缺氧缺血组GLUT1 mRNA和GLIUT3 mRNA的表达分别为0.674±0.083、0.785±0.093,显著高于假手术组(0.374±0.061、0.519±0.060)(Pa<0.01);孕酮组GLUT1 mRNA和GLUT3 mRNA的表达分别为0.957±0.077、1.138±0.090,显著高于假手术组(0.374±0.061、0.519±0.060)和缺氧缺血组(0.674±0.083、0.785±0.093)(Pa<0.01);正常组GLUT1 mRNA和GLUT3 mRNA的表达分别为0.363±0.063、0.503±0.085,与假手术组(0.374±0.061、0.519±0.060)比较均无显著差异(Pa>0.05).结论 孕酮通过上调GLUT1 mRNA和GLUT3 mRNA的表达增加脑内葡萄糖的转运,以维持脑组织的能量供给,是其发挥脑保护作用的机制之一.     

钳夹子宫血管致宫内生长迟缓幼鼠肝及脑组织变化的研究

目的　建立简便可靠的大鼠宫内发育迟缓(IUGR)模型,观察其幼鼠肝及脑重量和病理变化。方法　将大鼠分为2组:钳夹组于孕17d 行双侧子宫血管钳夹术30m in;对照组行同期开关腹术,但不钳夹子宫血管。随机获得孕21d 剖宫产及自然分娩两队。结果　剖宫产队:钳夹组幼鼠体重、肝重、脑重均明显低于对照组(P< 0.05),肝及脑组织光镜下有明显的病理形态学异常。自然分娩队:生后d6 两组幼鼠体重无明显差异(P> 0.05),但钳夹组幼鼠肝及脑重仍明显低于对照组(P<0.05),光镜下脑的异常改变部分恢复,肝的形态学改变恢复正常。结论　钳夹子宫血管法能造成IUGR模型,且IUGR幼鼠出现可测定的肝及脑损伤,生后6d 肝损伤恢复,脑损伤部分恢复     

改良型脑性瘫痪大鼠模型的建立与评估

目的 探讨孕后期脂多糖混合溶液腹腔注射及序贯缺氧缺血对幼鼠出生28 d时体质量、行为学的影响及脑组织病理学变化,评定新型脑性瘫痪动物模型构建的优势.方法 孕鼠(首次怀孕10 d)15只,随机取12只为实验组,孕16d时予脂多糖腹腔注射及缺氧处理,隔日1次,直至分娩,新生大鼠与母鼠为同一组,新生大鼠出生7d结扎双侧颈总动脉;对照组孕鼠于相应日期予9 g/L盐水腹腔注射至分娩,分娩后新生大鼠与母鼠为同一组.2组新生大鼠监测出生28 d生长发育情况,包括体质量、睁眼时间、抓力实验、旋杆实验,并行脑组织病理学检测.结果 实验组与对照组新生大鼠出生体质量分别为(5.6±0.9)g和(6.2±0.8)g,睁眼时间分别为左眼(16.9±2.0)d和(13.0±2.0)d,右眼(23.1±2.6)d和(13.7±1.7)d;2组比较差异有统计学意义(P均＜0.05)抓力测试过程中得分分别为(2.7±0.8)分和(1.5±0.4)分.神经功能缺损评分分别为(4.9±2.5)分和(1.2±1.0)分,2组相比较差异均有统计学意义(P均＜0.01).实验组和对照组旋杆实验得分分别为(1.9±0.6)分和(1.9±0.4)分,2组比较差异无统计学意义(P=0.871).实验组脑组织病理切片HE染色显示神经元排列紊乱,丢失,白质变薄,脑实质有炎性细胞浸润,并可见到明显细胞海绵状变性;对照组灰质层清晰,神经元规则排列,灰白质界限清楚.结论 孕后期予脂多糖腹腔注射及序贯缺氧缺血能构建稳定的脑性瘫痪模型.     

电针对先天性脑损伤仔鼠脑组织脑源性神经生长因子表达的影响

目的探讨电针对先天性脑损伤仔鼠脑组织脑源性神经生长因子(BDNF)表达的影响和机制。方法给孕17 d的脂多糖组孕鼠腹腔注射脂多糖450μg/(kg.d),制备脑损伤模型;对照组孕鼠腹腔注射等量生理盐水。脂多糖组仔鼠随机分为非干预组和电针组,电针组于7日龄开始干预,每日1次,干预至28日龄。选取百会、曲池及足三里为干预穴位。对照组、非干预组仔鼠均常规饲养。采用免疫组织化学方法检测1、14、21、28日龄仔鼠脑组织BDNF表达情况。结果 1日龄非干预组脑组织BDNF阳性细胞计数高于对照组,差异有统计学意义(P<0.01),此后两组间比较差异无统计学意义(P>0.05);电针组各日龄仔鼠脑组织BDNF阳性细胞计数高于非干预组和对照组,差异有统计学意义(P<0.01)。结论宫内感染可引起脑损伤仔鼠脑组织BDNF阳性表达增强;电针能持续上调脑损伤仔鼠脑组织BDNF阳性表达。     

亚低温干预对缺氧缺血新生鼠脑源性神经营养因子mRNA表达的影响

目的 探讨亚低温对缺氧缺血脑损伤(HIBD)新生大鼠脑源性神经营养因子(BDNF)mRNA表达的影响.方法 新生7日龄Wistar大鼠84只,随机分为:假手术组(n=6),31 ℃亚低温干预组(n=36),非亚低温干预组(对照组,n=36)及正常对照组(n=6).于分组后6、12、24、48、72、96 h用原位杂交技术测定BDNF mRNA.用Tunel染色和免疫组化技术检测神经元凋亡数.结果 HIBD缺血再灌注后脑组织BDNFmRNA表达增加,亚低温组HIBD脑组织BDNFmRNA表达与未干预组比较差异有统计学意义,亚低温组脑组织海马、皮层区细胞凋亡数与未干预组比较差异有统计学意义.结论 亚低温可通过增加HIBD后脑组织海马、皮层BDNFmRNA的表达水平,抑制细胞凋亡而发挥脑保护作用.     

Carbamazepine-Induced Brain Weight Reduction in Chick Embryos

Abstract The antiepileptic drug carbamazepine (CBZ) had been considered to be relatively safe for the fetus. We examined the teratogenicity of CBZ using chick embryos, with particular focus on the brain. A single dose of 5 mg was injected into the yolk sac of White Leghorn chick embryos at 24, 72, 120, 168 or 216 hours of incubation. On day 19 of incubation, embryos were removed, and counted and recorded as either live or dead. Each live embryo was inspected for the presence of external abnormalities, and body and brain weight were measured. There was no statistically significant difference between treated groups and control groups at all hours of incubation for mean body weight and incidence of embryo death. Mean brain weight was significantly lighter in treated groups at 120 and 168 hours of incubation. A significant difference in mean brain/body weight ratio was observed only at 120 hours of incubation. External abnormalities in treated embryos were not found with any consistency and these incidences were not significantly higher compared to those in the control groups. This experiment provides evidence regarding the risk of teratogenesis due to CBZ in the brain of chick embryo. The 120 hours of incubation in chick embryos corresponds to the 34-36th day after conception in humans.     

选择性头部亚低温对新生儿缺氧缺血性脑损伤的治疗作用

目的 探讨选择性头部亚低温对足月新生儿窒息后缺氧缺血性脑损伤（ＨＩＢＤ）的神经保护作用及其安全性。方法 将２２例重度窒息足月新生儿随机分为治疗组（１１例）和对照组（１１例）。治疗组采用选择性头部降温方法,维持鼻咽温度为（３４．０±０．２）℃,持续７２ ｈ;对照组不进行降温治疗。两组均于治疗后６４～７２ ｈ测脑脊液神经元特异性烯醇化酶（ＮＳＥ）,血ＣＫ－ＭＢ,尿β２微球蛋白（β２－ＭＧ）等。于治疗前、生后１０ ｄ和３个月进行常规１６导ＥＥＧ检测,并采用新生儿神经行为评分（ＮＢＮＡ）、婴幼儿发育量表（ＣＤＣＣ）进行神经行为发育评价。结果 治疗组脑脊液ＮＳＥ为（１９．５±２．２）μｇ／Ｌ,明显低于对照组[（２４．６±５．３）μｇ／Ｌ］（Ｐ ＜ ０．０１）;生后２８ ｄ治疗组ＮＢＮＡ评分为（３６±３）分,低于对照组[（３２±２）分］（Ｐ＜０．０１）。治疗前两组ＥＥＧ均异常,生后１０ｄ,３个月治疗组ＥＥＧ均正常,对照组２例持续重度异常。两组患儿血ＣＫ－ＭＢ及尿β２－ＭＧ差异无显著性（Ｐ＞０．０５）。结论 选择性头部亚低温对足月新生儿窒息后ＨＩＢＤ可能具有神经保护作用,临床上具有安全性。     

水通道蛋白4在脂多糖致大鼠脑水肿的表达及与血脑脊液屏障的关系

目的观察脂多糖（LPS）致幼年大鼠感染性脑水肿后水通道蛋白4 mRNA（AQP4mRNA）的表达变化,探讨其作用机制。方法将50只幼鼠随机分为内毒素组（40只）和对照组（10只）,内毒素组又按时间点分为6、12、24及48h4个亚组,每组均为10只。于预定时间点处死动物,制备脑组织标本。用干湿重法测定不同时间点脑组织含水量,甲酰胺法测定伊文思蓝（EB）水平,RT-PCR技术检测脑组织内AQP4 mRNA的表达。结果内毒素组脑组织含水量和EB水平明显高于对照组。LPS注射后6h,脑组织AQP4 mRNA水平的表达均明显增加,12h时达高峰,各时间点与对照组比较均有显著性差异（Pa〈0.01）。结论感染性脑水肿后脑组织中AQP4 mRNA的表达增加,且与血脑脊液屏障的破坏程度呈正相关。     

缺氧缺血性脑损伤

由于高代谢的需要,脑高度的依赖充分的氧供给,全脑性缺氧/缺血会导致快速的能量丧失,引起一连串的包括兴奋毒性损伤、炎症和凋亡所共同造成的脑损伤.围生期窒息复杂的先天性心脏病开放性手术及意外的捂热综合征均是酿成缺氧/缺血脑损伤的危险因素.缺氧/缺血愈久,损伤愈重,预后也愈差.因而需及早给予积极和恰当的治疗.     

MicroRNA与缺氧缺血性脑损伤

MicroRNA(miRNA)是一组20 ～ 24个核苷酸长度的非编码单链RNA,在转录后水平抑制或诱导靶基因表达.在缺氧缺血性脑损伤(HIBD)中,miRNA通过缺氧诱导因子1α(HIF-1α)依赖或非依赖途径,快速可逆地调控中枢神经系统损伤及修复过程.现就HIF-1d、miRNA功能及HIBD后其相互作用机制作一综述,总结miRNA在HIBD诊断及治疗中发挥的重要作用.     

Severe Traumatic Brain Injuries in Children

Severe traumatic brain injury in the pediatric age group is a serious public health problem. Societal goals must prioritize safety in automobiles, bicycles, and sports to prevent primary (physical) injuries. With effective emergency management and expeditious referral to a trauma center with pediatric critical care and neurosurgical expertise, the management and eventual outcome of head injured children can be optimized. Monitoring for, avoiding, and aggressively treating hypoxia, hypotension, and fever are of paramount importance to minimize secondary injury. Routine or prophylactic hyperventilation is no longer considered appropriate. Management specifically geared toward controlling ICP begins with neurosurgical procedures to remove space-occupying lesions and the placement of an ICP monitor. Brain swelling and intracranial hypertension typically progress and peak over a period of several days after the primary injury. First-tier therapy includes sedation and analgesia, drainage of CSF, neuromuscular blockade, hyperosmolar therapy, and mild hyperventilation. Second-tier therapy may include more aggressive hyperventilation, barbiturate-induced coma, hypothermia, lumbar CSF drainage, and decompressive craniectomy in selected cases. Although there is a lack of prospective, randomized, clinical trials in the management of traumatic brain injury in the pediatric population, expert consensus recommendations based on vast empirical experience, some clinical trials, and adult guidelines have been published.     

Brain abscesses in cyanotic heart disease

Sixty cases of brain abscesses in patients with cyanotic heart disease is reported. Forty four (73.3%) belonged to pediatric age group. There was only single case of infratentorial abscess located in the cerebellar paravermian region. The abscesses were multiloculated in 42%, multiple in 10% and solitary in 48% cases. Streptococci was the commonest (77%) micro-organism isolated from pus culture. Forty eight patients were treated by aspiration through twist drill, 7 patients conservatively and 5 had primary excision of abscesses. Forty four patients improved in their neurological status, three had fixed neurological deficits and 5 patients deteriorated further. There were 8 deaths. Complication like cyanotic spells was recorded in 17% cases treated by aspiration. None of the patients treated by twist drill aspiration had seizure. It is suggested that aspiration of abscesses through twist drill hole and antibiotic therapy could be the treatment of choice. Vascular slowing in a localised area resulting in infraction and thus preparing the focus for abscess formation is the possible mechanism in the evolution of these abscesses.     

孕酮对缺氧缺血性脑损伤新生鼠脑组织孕酮受体的影响

目的观察孕酮对缺氧缺血性脑损伤(HIBD)新生鼠脑组织中孕酮受体的影响,探讨孕酮对新生鼠HIBD的保护机制。方法24只7日龄新生Wistar大鼠随机分为假手术组、缺氧缺血组、药物预防组。缺氧缺血组和药物预防组大鼠先行左侧颈总动脉结扎术,然后将动物置于37℃恒温密闭容器中,以1.5L/min的速度吸入80mL/L氧气和920mL/L氮气的混合气体2.5h,建立缺氧缺血脑病(HIE)动物模型。假手术组仅分离左侧颈总动脉,不结扎,亦不做缺氧处理。药物预防组动物于建立模型前30min按8mg/kg腹腔注射0.5g/L的孕酮溶液,假手术组和缺氧缺血组注射同等量的9g/L盐水溶液,24h后大鼠被全部处死,采用免疫组织化学方法检测各组大鼠脑组织中孕酮受体表达的变化。结果24只大鼠全部进入结果分析,无脱失。各组大鼠脑组织的胞质和胞核中均有孕酮受体表达,缺氧缺血组大鼠脑组织中孕酮受体的表达与假手术组比较明显减少(P<0.05),药物预防组孕酮受体的表达较缺氧缺血组明显增多(P<0.05)。结论孕酮可增强新生鼠缺氧缺血时脑组织中孕酮受体的表达,通过基因组效应发挥对HIBD的保护作用。     

Biochemical Studies on the Effect of Maternal Hyperphenyl-alaninemia on Fetal Brain Maturation of Mice

Abstract The effects of maternal hyperphenylalaninemia during pregnancy on the biochemical maturation of neonatal mice brains were examined, thus establishing the critical concentration of phenylalanine in maternal blood and the critical period of maternal hyperphenylalaninemia during pregnancy. Hyperphenylalaninemia was induced by giving chow supplemented with 3%, 4%, 5%, or 6% phenylalanine (Phe.) and 0.12% p-chlorophenylalanine (PCPA) for at least one month and then throughout pregnancy. Some of the pregnant mice fed the 6% Phe. diet before pregnancy received a normal diet after conception (6%: A).
Offspring from each group were decapitated two days after birth. Their brains were removed and then divided into the cerebrum and the brain stem including the cerebellum. Total protein, RNA and DNA were measured biochemically. All kinds of markers of the newborn mice born to the 5% and 6% mothers, the weight and the contents of the protein, RNA and DNA, were reduced significantly in both the cerebrum and brain stem. In the 4% group, however, only the brain stem was affected. The 3% group showed reductions neither in the weight nor the protein and nucleic acids contents in both the cerebrum and brain stem. In the 6%:A group, in which the diet was returned to normal just after conception, total protein, RNA and DNA were reduced in the brain stem, but not in the cerebrum.
These results suggest that the critical concentration of maternal blood phenylalanine during pregnancy in the mouse is 11mg/dl, which is that corresponding to the 3% group, and also suggest that it is too late to begin the low phenylalanine diet after conception.