脑出血后血红蛋白对血脑屏障的影响

目的 探讨脑出血后血红蛋白(Hb)对血脑屏障结构和功能的影响. 方法 108只雄性SD大鼠按随机数字表法分为正常对照组(12只)、Hb组(48只)和假手术组(48只);再进一步依据模型制作完成后观察时间点的不同,将Hb组和假手术组分为6h、24 h、3d、7d共4个亚组(每个亚组12只).应用HE染色、铁染色分别观察Hb注入大鼠脑内后组织学变化和铁离子释放规律.利用伊文氏蓝检测血脑屏障的通透性.免疫荧光和荧光定量PCR检测血脑屏障紧密连接蛋白claudin-5和ZO-1表达的变化. 结果 Hb注入后大鼠脑组织中可见明显的水肿坏死,3d和7d时可见铁离子的释放和蓄积.Hb组的伊文氏蓝渗出量明显高于假手术组,差异有统计学意义(P＜0.05).免疫荧光结果显示Hb注入大鼠脑内后可见血管内皮细胞间紧密连接蛋白claudin-5和ZO-1表达不连续,表达水平下降.在mRNA水平,Hb组claudin-5和ZO-1表达水平明显低于假手术组,差异有统计学意义(P＜0.05). 结论 脑出血发生后,Hb可能直接引起血脑屏障结构和功能的破坏,进而参与脑水肿的发生、发展过程.     

脑出血后血脑屏障紧密连接蛋白occludin的表达变化

目的 探讨脑出血后血脑屏障微血管内皮细胞间紧密连接蛋白occludin的表达变化. 方法 将SD雄性大鼠按随机数字表法分为正常对照组和脑出血组,再按时间因素将脑出血组分为出血后6h、24h、48h、72h、7d、14d6个亚组.采用脑内注入自体血法制作脑出血模型.HE染色观察脑出血后血肿周围脑组织的形态学改变;透射电镜观察脑出血后血肿周围紧密连接的超微结构改变;免疫荧光染色检测脑出血后血肿周围紧密连接蛋白occludin的表达分布状况;定量RT-PCR检测脑出血后血肿周围脑组织中occludin mRNA的表达状况. 结果 与正常对照组相比,脑出血组血肿周围脑组织出现水肿,在48 h左右尤为明显,局部可见明显脑细胞坏死及炎细胞浸润.脑出血后血肿周围紧密连接发生明显破坏,内皮细胞间出现裂隙.免疫荧光染色结果显示:正常对照组紧密连接蛋白occludin呈强阳性表达.脑出血后6hoccludin的表达即开始下降,呈阳性表达;脑出血后24～72h occludin的表达维持在较低水平,呈弱阳性表达.定量RT-PCR结果显示:脑出血后血肿周围脑组织中occludin mRNA相对含量明显降低,在6～72 h持续维持在较低水平,与正常对照组比较差异均有统计学意义(P＜0.05). 结论 脑出血发生后,紧密连接蛋白occludin 的表达下降,这可能是脑出血发生后血脑屏障破坏及脑水肿发生发展的重要分子基础之一.     

黄体酮对脑缺血再灌注大鼠紧密连接蛋白ZO-1和occludin表达的影响

目的探讨黄体酮对大鼠局灶性脑缺血再灌注后血脑屏障紧密连接蛋白ZO-1、occludin表达及血脑屏障通透性的影响。 方法将42只健康雄性SD大鼠按随机数字表法分为假手术组（6只）和缺血再灌注组,后者再按再灌注时间分为缺血2h再灌注3h、6h、12h、24 h、48 h及72h组（各6只）。缺血再灌注组用线栓法制备成大鼠大脑中动脉缺血再灌注模型。采用荧光分光光度法测定缺血侧脑组织中伊文氏蓝(EB)含量来评价血脑屏障的通透性,Western blotting法检测脑组织ZO-1和occludin的表达。取EB漏出最多组的时间点,增设黄体酮干预组和溶剂对照组（各6只）,与相同时间点的缺血再灌注组比较,观察黄体酮对ZO-1、occludin表达及血脑屏障通透性的影响。 结果 缺血2h再灌注3h时脑组织EB含量开始增加,再灌注24 h时达高峰;ZO-1、occludin的表达在缺血2h再灌注3h时开始下降,再灌注24 h时达最低。黄体酮干预组EB含量明显低于缺血2h再灌注24 h组,差异有统计学意义(P＜0.05)。黄体酮干预组ZO-1和occludin的表达水平均明显高于缺血2h再灌注24 h组,差异有统计学意义(P＜0.05)。 结论 黄体酮町抑制缺血再灌注大鼠紧密连接蛋白ZO-1和occludin表达的降低,从而起到保护血脑屏障的作用。     

急性创伤性脑损伤大鼠血脑屏障通透性变化与Claudin-5的相关性研究

目的 研究大鼠急性创伤性颅脑损伤(TBI)后血脑屏障(BBB)通透性的变化和机制.方法 雄性Wistar大鼠96只按随机数字表法分为假手术组和TBI组,TBI模型参照Feeney自由落体致伤法制作,假手术组仅行开颅术不行打击致伤.每组按伤后处死时间的不同分为3h、6h、12h 、24 h、48 h、72h6个亚组,每亚组4只.采用干湿重比法测定脑组织含水量,Western blotting检测脑皮质紧密连接蛋白Claudin-5的表达,伊文思蓝(EB)法检测脑组织BBB通透性变化. 结果 与假手术组比较,TBI组大鼠创伤后不同时间点脑组织含水量、EB含量均增多.组内比较显示二者创伤后3h开始增多,24 h达高峰,随后下降,差异有统计学意义(P＜0 05);与假手术组比较,TBI组大鼠创伤后6h、12h、24 h、48 h、72 h紧密连接蛋白Claudin-5表达降低.组内比较显示其创伤后6h表达降低,24 h达最低值,随后回升,差异有统计学意义(P＜0.05);大鼠脑Claudin-5蛋白的相对表达水平和脑组织水含量、脑组织EB含量呈负相关关系(r=-0.994,P=0.000;r=-0.846,P=0.036).脑组织含水量和EB含量呈正相关关系(=0.863,P=0.027). 结论 TBI后大鼠BBB通透性变化和脑损伤程度具时间依赖性,紧密连接蛋白Claudin-5与BBB变化具有一定程度的相关性.     

大鼠脑室出血后急性期脑损伤病理特点的初步探讨

目的 初步探讨大鼠脑室出血后急性期脑损伤的病理特点. 方法 健康成年雄性SD大鼠38只按随机数字表法分为对照组和脑室出血组,分别采用立体定向技术向右侧脑室内注入生理盐水200 μL或自体股动脉血200 μL手术建模.术后24 h观察大鼠体质量减轻情况,采用小动物Micro-CT扫描及大体标本脑室切面观察脑室铸型;采用干湿重法测定术后24 h大鼠脑组织含水量;采用伊文思蓝染色法(24 h时)和IgG免疫荧光染色法(48 h时)观察大鼠血脑屏障损伤情况.结果 术后24 h时脑室出血组体质量减轻(5.29％±0.59％)明显高于对照组(3.36％±1.10％),差异有统计学意义(P＜0.05).脑室出血组Micro-CT扫描及脑室切面可见脑室积血铸型并明显扩张.脑室出血组双侧大脑半球脑组织含水量(左侧:78.25％±0.29％;右侧:78.46％±0.21％)均明显高于对照组(左侧:77.64％±0.25％;右侧:77.91％±0.10％),差异有统计学意义(P＜0.05).术后24 h时脑室出血组伊文思蓝脑组织渗出量明显高于对照组,48h时脑室出血组侧脑室脉络丛免疫球蛋白IgG表达明显高于对照组. 结论 脑室出血后脑损伤除脑积水外还存在急性脑水肿、血脑屏障损伤等病理损害,其可能是脑室出血后除继发脑积水外急性脑损伤的重要环节.     

HIF-1α、VEGF在脑出血灶周的表达意义

目的 观察血肿周边脑组织中HIF-1α与VEGF蛋白的表达情况并探讨二者表达的相关性.方法 SD大鼠35只,随机分为对照组、假手术组、脑出血组,脑出血组又分为6h、24h、72h、7d和21d 5个亚组,每组5只.采用自体血脑内注射法建立脑出血动物模型,应用免疫组化的方法检测脑出血后不同时间血肿周边脑组织中HIF-1α与VEGF蛋白的表达情况.结果 脑出血后,HIF-1α和VEGF蛋白的表达均随时间呈进行性增加,并于出血后24～72h达到高峰且维持到第7天.与对照组和假手术组比较,差异均有统计学意义(P<0.01).脑出血后,HIF-1α和VEGF蛋白的表达呈正相关.结论 HIF-1α与VEGF蛋白在血肿周边脑组织中均有表达,并具有一致性,可能与脑出血后微循环的重建有关.     

局部亚低温对大鼠脑出血后血肿周围脑组织白介素-1β表达的影响

目的 观察局部亚低温对脑出血大鼠血肿周围脑组织的形态学变化和对白介素(IL)-1β表达的影响.方法 72只Wistar大鼠随机分为假手术组和脑出血后6 h、24 h、48 h、72 h、7 d组,每组再分为常温亚组和亚低温亚组,每个亚组6只大鼠.采用自体不凝血注人大鼠尾状核制备脑出血模型.各亚低温亚组注血后实施亚低温治疗4 h,维持脑温在(33±0.5)℃.观察血肿周围组织的形态学改变和IL-1β表达的变化.结果 亚低温亚组各时间点脑组织水肿明显轻于常温亚组;神经元变性坏死、炎症反应及胶质细胞增生程度明显轻于常温亚组.脑出血后6 h血肿周围脑组织IL-1β开始表达,48 h达高峰,7 d时仍明显高于对照亚组(均P＜0.01).脑出血24 h～7 d亚低温亚组IL-1β表达水平较相应时点常温亚组显著降低(均P＜0.01).结论 亚低温治疗能明显抑制血肿周围IL-1β的过度表达,减轻血肿周围脑组织的炎症反应.     

内质网蛋白29在大鼠脑出血继发性脑损伤中的作用研究

目的观察大鼠脑出血后脑组织中内质网蛋白29(ERp29)的表达变化,进而探讨其在脑出血继发性脑损伤中的作用。 方法将60只SD大鼠按随机数字表法分为2组：对照组(10只,不做处理)和实验组(50只,在脑立体定位仪下采用自体血注入尾状核法制备脑出血模型)。实验组再分为术后6h、12h、18h、24 h、48 h5个时相点,对各个时相点的模型鼠分别采用RT-PCR和Western blotting方法检测脑组织中ERp29和内质网伴侣蛋白Bip/GRp78 mRNA及蛋白的表达。结果在脑出血大鼠模型中,BiP/GRp78 mRNA及蛋白表达在术后12h开始升高,并随着时间的推移在术后18h、24h、48 h继续逐渐升高,于术后48 h达顶峰,与对照组比较差异均有统计学意义(P＜0.05)。ERp29 mRNA及蛋白表达在术后6h、12h无明显变化,与对照组比较差异无统计学意义(P＞0.05);而在术后18h、24h、48h ERp29 mRNA及蛋白表达明显升高,与对照组比较差异均有统计学意义(P＜0.05)。 结论大鼠脑出血后18h时血肿周围脑组织细胞中发生了内质网应激反应,而ERp29在此过程中表达升高,推测其有可能作为一种保护因子并以与BiP/GRp78相互作用形成复合物的形式来抵抗细胞内质网应激反应,进而减轻血肿对周围脑组织造成的损害。     

G-CSF对脑出血大鼠模型抗炎作用及作用机制的初步研究

目的 研究粒细胞集落刺激因子(G-CSF)对脑出血大鼠模型出血灶周脑组织中炎症反应的影响,并初步探讨G-CSF抗炎作用的可能作用机制.方法 36只成年雄性Wistar大鼠随机分成两组:对照组和G-CSF治疗组,每组各18只大鼠.自体血注入法建立大鼠脑出血模型.术后2h和12h,G-CSF治疗组分别给予粒细胞集落刺激因子50μg/kg)皮下注射;对照组注入等量生理盐水.于术后24h、7d、14d每组分别取6只大鼠,处死取脑,免疫组化染色计数TNF-ot、IL-1β阳性细胞;Western blot检测NF-κB/IκBα蛋白含量.结果 脑出血灶周组织中的IL-1β阳性细胞和TNF-α阳性细胞在出血24h后最多,7d、14d较前下降.G-CSF组与对照组相比,IL-1β和TNF-α阳性细胞数在24h和7d时下降明显,差异显著性(P＜0.01),而14d下降不明显;G-CSF组与对照组相比,24h时NF-κB表达减少而IκB表达增加,差异有统计学意义(P＜0.05).结论 G-CSF通过NF-κB途径,减轻血肿周围脑组织中TNF-α、IL-1β的生成,发挥抗炎症作用从而在脑出血后发挥神经保护作用.     

大鼠脑出血后基质金属蛋白酶的动态表达及七叶皂苷钠对其表达的影响

目的 观察大鼠脑出血(ICH)后基质金属蛋白酶-2( MMP-2)、MMP-9蛋白动态表达及其与血肿周围脑组织含水量的关系,以及观察七叶皂苷钠对MMP-2、MMP-9表达的影响.方法 Wistar大鼠250只随机分为4组:正常对照组10只、假手术组、ICH组和七叶皂苷钠治疗组各80只,于制模后6 h、12 h、24 h、48 h、72 h、120 h、7 d、15 d 8个时间点,测定各组血肿周围脑组织含水量、MMP-2和MMP-9的蛋白表达.结果 治疗组神经功能缺损较ICH组明显改善,尤以6 h～7 d时明显(P<0.01～0.05);6～120 h各治疗组血肿周围脑组织含水量较ICH组明显减少(P<0.01～0.05);ICH后MMP-2蛋白表达在6 h达到高峰,12 h时下降,与正常对照组相比具有统计学意义 (均P<0.01),治疗组MMP-2蛋白表达在各时间点较ICH组明显减少(均P<0.01);ICH后MMP-9蛋白表达在6 h开始上升,24～48 h达高峰,72 h时下降,与正常对照组相比,具有统计学意义(均P<0.01),其表达水平与血肿周围脑组织含水量呈正相关 (r=0.949, P<0.05);治疗组MMP-9蛋白表达在各时间点较ICH组明显减少(均P<0.01).结论 大鼠ICH后MMP-2、MMP-9蛋白的表达是ICH后早、中期脑水肿形成主要因素,七叶皂苷钠能降低MMP-2、MMP-9蛋白表达和脑组织含水量,对ICH具有保护作用.     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.