蛛网膜下腔出血后大鼠基底动脉p38MAPK信号传导途径研究

目的探讨蛛网膜下腔出血(SAH)后大鼠基底动脉中p38丝裂原活化蛋白激酶(p38MAPK)信号传导通路的活化情况以及与脑血管痉挛(CVS)的关系。方法通过枕大池二次注血方法制作大鼠SAH模型,以免疫组化方法和逆转录酶-多聚酶链反应分析,分别从蛋白、基因水平分析SAH后基底动脉中p38MAPK信号传导通路的活化情况。结果 SAH后大鼠基底动脉逐渐出现痉挛。基底动脉磷酸化p38MAPK表达逐渐增加,3 d时达高峰并持续至第5 d,14 d时恢复正常。p38MAPK基因表达在注血后1 d明显增加,逐渐增加,于5 d时达高峰,14 d仍维持较高水平。结论SAH后大鼠基底动脉中p38MAPK信号传导通路激活,可能诱导CVS的发生。     

半胱氨酸蛋白酶-3抑制剂对蛛网膜下腔出血后脑血管痉挛的作用

目的观察早期使用大剂量特异性半胱氨酸蛋白酶-3（Caspase-3）抑制剂对蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的作用。方法将20只雄性新西兰白兔随机等分为4组：①对照组：枕大池注人生理盐水；②SAH组；③SAH＋二甲基亚砜（DMSO）组：④SAH＋Z—DEVD—FMK（特异性Caspase-3抑制剂）组。采用枕大池2次注血法建立兔SAH模型。2次注血后第5天采用灌流固定法处死动物，留取基底动脉标本。用免疫组化及原位细胞凋亡检测法（TUNEL）分别检测基底动脉内皮细胞Caspase-3的表达及凋亡情况，并通过测定基底动脉血管横截面积判断有无CVS。结果免疫组化显示SAH＋Z—DEVD—FMK组基底动脉内皮细胞Caspase-3表达较SAH组及SAH＋DMSO组显著性降低（P〈0．05）。TUNEL染色示SAH＋Z—DEVD—FMK组基底动脉内皮细胞凋亡程度较SAH组及SAH＋DMSO组显著性减轻（P〈0．01）。基底动脉横截面积测定结果提示SAH组及SAH＋DMSO组较对照组显著性缩小（P〈0．01），而SAH＋Z—DEVD—FMK组较SAH组及SAH＋DMSO组显著性增大（P〈0.01）。结论早期使用大剂量Z—DEVD—FMK能减少兔SAH模型基底动脉内皮细胞的凋亡并减轻CVS。     

蛛网膜下腔出血后高迁移率族蛋白B1表达变化的调控机制研究

目的 探讨蛛网膜下腔出血(SAH)后大鼠基底动脉中高迁移率族蛋白B1 (HMGB1)表达变化的p38丝裂原活化蛋白激酶(p38 MAPK)的调控机制.方法 通过枕大池二次注血方法制作大鼠SAH模型,注血前预先给予p38MAPK抑制剂SB203580,应用酶联免疫吸附试验(ELISA)、逆转录酶-多聚酶链反应(RT-PCR)分别从蛋白、基因水平分析抑制p38MAPK途径后发生SAH时基底动脉中HMGB1的表达情况.结果 SAH后大鼠基底动脉逐渐出现痉挛.抑制p38MAPK途径后基底动脉HMGB1蛋白、基因水平在SAH后升高,于5～7d达高峰,之后逐渐降低,14 d时仍维持较高水平.与枕大池二次注血组基底动脉HMGB1蛋白、基因水平相比,SB203580干预后基底动脉HMGB1浓度相比对照组每个时间点均降低.结论 SB203580能下调枕大池二次注血后基底动脉HMGB1蛋白和基因的表达,p38MAPK信号通路可能直接参与SAH后HMGB1的诱生机制.     

钾离子通道激动剂对蛛网膜下腔出血后脑血管痉挛的作用

目的 观察早期使用不同剂量特异性钾离子通道激活剂对蛛网膜下腔出血（SAH）后脑血管痉挛（CVS）的作用。方法 将24只雄性新西兰白兔随机等分为4组：①对照组：枕大池注入生理盐水；②SAH组；③SAH＋小剂量钾离子通道激活剂Cromakalin组（0．1mg／kg）；④SAH＋大剂量Cromakalin组（0．3mg／kg）。采用枕大池注血法建立兔SAH模型，1h后开始静脉输注Cromakalin，每12h给药1次，共4次。注血后48h采用灌注固定法处死动物动物，留取基底动脉标本，通过测定基底动脉血管横截面积来评价CVS的程度。结果 基底动脉横截面积测定的结果提示SAH组较对照组明显缩小（P〈0．01），而SAH＋小剂量Cromakalin组及SAH＋大剂量Cromakalin组均较SAH组痉挛明显改善（P〈0．05）。结论 早期使用特异性钾离子通道激活剂Cromakalin能改善兔SAH模型的基底动脉血管痉挛。     

促红细胞生成素缓解蛛网膜下腔出血后脑血管痉挛的实验研究

目的 研究早期全身使用促红细胞生成素(EPO)对蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用并探索其作用机理. 方法 将30只雄性新西兰白兔按照随机数字表法等分为5组:(1)空白组;(2)对照组;(3)SAH组;(4)SAH+安慰剂组;(5)SAH+重组人促红细胞生成素(rHuEPO)组.后三组采用枕大池注血法建立兔SAH模型.注血后48 h采用灌注同定法处死动物,留取基底动脉标本.通过测定基底动脉血管横截面积判断有无CVS,并用原位细胞凋亡检测法(TUNEL)检测血管内皮细胞凋亡情况. 结果 基底动脉横截面积测定的结果 提示空白组和对照组、SAH组和SAH+安慰剂组比较,差异无统计学意义(p>0.05);SAH组和SAH+安慰剂组较空白组和对照组明显缩小,差异有统计学意义(P<0.05)SAH+rHuEPO组较SAH组和SAH+安慰剂组明显增大,差异有统计学意义(P<0.05).但小于空白组和对照组.TUNEL染色显示SAH+rHuEPO组血管内皮细胞凋亡程度较SAH组和SAH+安慰剂组减轻,差异有统计学意义(P<0.05). 结论 早期全身使用rHuEPO能减少兔SAH模型基底动脉血管内皮细胞凋亡并部分缓解CVS.     

辛伐他汀对兔蛛网膜下腔出血后迟发性脑血管痉挛中血管壁增殖的影响

目的 探讨辛伐他汀对兔蛛网膜下腔出血(SAH)后迟发性脑血管痉挛(CVS)中血管壁增殖的影响.方法 36只新西兰大白兔随机分为3组:①对照组,常规饲养并枕大池二次注入0.9%生理盐水;②SAH组,通过二次枕大池注血建立SAH模型;③辛伐他汀+SAH组,每日胃灌辛伐他汀5 ms/kg,连续7 d后建立SAH模型.各组兔模型前后行两次脑血管造影.灌注后取基底动脉组织制作病理切片,分别于光镜和透射电镜下观察其显微以及超微结构.采用免疫组化及免疫荧光方法检测基底动脉组织中增殖细胞核抗原(PCNA)及α-平滑肌肌动蛋白(α-SMA)表达量的变化,同时采用Real-Time PCR检测其血小板源性生长因子-B(PDGF-B)基因表达量的变化.采用SPSS10.0软件进行统计分析.结果 通过脑血管造影可以观察到二次注血后兔基底动脉出现明显的痉挛,管径变细;而给予辛伐他汀后,痉挛减轻.SAH组兔基底动脉壁略有增厚,电镜显示平滑肌细胞内合成旺盛;而给予辛伐他汀预处理后这些变化明显减轻.SAH组兔基底动脉管壁平滑肌细胞内α-SMA、PCNA、PDGF-B表达明显高于对照组(P＜0.05),而给予辛伐他汀后三者表达量明显降低(P＜0.05).结论 辛伐他汀可能通过抑制迟发性CVS中血管壁平滑肌细胞的增殖来缓解SAH后迟发性CVS.     

细胞色素C在兔蛛网膜下腔出血后脑血管痉挛中的作用

目的 观察兔蛛网膜下腔出血(SAH)后基底动脉细胞色素C(Cyt-C)的表达规律,以探讨其在细胞凋亡中的作用及与脑血管痉挛(CVS)的关系.方法 36只新西兰大白兔随机分为对照组(6只)和SAH组(30只).SAH组采用枕大池二次注血法建立兔CVS模型,对照组行枕大池二次注入生理盐水.应用苏木精-伊红染色观察基底动脉形态学变化,TUNEL法检测基底动脉上细胞凋亡情况,免疫组化检测基底动脉内皮细胞和平滑肌细胞的Cyt-C表达.结果 对照组基底动脉结构正常,偶见凋亡细胞和Cyt-C表达.SAH组基底动脉出现相应病理学改变,管腔狭窄呈双相期改变;基底动脉上细胞凋亡和Cyt-C表达均在SAH后增多,于第7天达高峰,第10天逐渐下降.与对照组比较,SAH组内各时间点基底动脉直径和Cyt-C表达差异均有统计学意义(P<0.05).结论 兔CVS模型的基底动脉中存在细胞凋亡,Cyt-C是启动细胞凋亡的重要因素,在CVS发生和发展过程中起重要作用.     

骨桥蛋白缓解大鼠SAH后脑血管痉挛的抗炎机制研究

目的探究重组骨桥蛋白(r-OPN)的抗炎机制对缓解蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用。方法将48只大鼠随机分为假手术+安慰剂组(n=12)、SAH+安慰剂组(n=12)、SAH+r-OPN 0.03(0.03μg)组(n=12)和SAH+r-OPN 0.1(0.1μg)组(n=12)。采用枕大池二次注血法建立SAH模型。首次注血后72 h取脑脊液,处死大鼠,苏木精-伊红(HE)染色后测量基底动脉横截面积和管壁厚度,判断脑血管痉挛情况,Western blot测定基底动脉磷酸化c-Jun氨基末端激酶(p-JNK)水平,采用酶联免疫吸附法(ELISA)检测脑脊液中肿瘤坏死因子-α(TNF-α)及白介素-1β(IL-1β)水平。结果与SAH+安慰剂组相比,SAH+r-OPN 0.1组大鼠基底动脉横截面积明显增加,管壁厚度明显减轻,基底动脉p-JNK表达明显降低,脑脊液TNF-α、IL-1β水平明显降低。结论r-OPN能有效缓解SAH后CVS,其机制可能与降低p-JNK的表达,从而抑制TNF-α及IL-1β的产生,抑制SAH后的炎症反应有关。     

促红细胞生成素对蛛网膜下腔出血后早期脑保护作用的实验研究

目的 研究全身使用促红细胞生成素（EPO）对蛛网膜下腔出血（SAH）后的早期脑保护作用。方法 将30只雄性新西兰白兔随机等分为5组：①空白组；②对照组；③SAn组；④SAH＋安慰剂组；④SAH＋重组人促红细胞生成素（rHuEPO）组。采用枕大池一次注血法建立兔SAH模型。注血后48h取脑脊液，采用酶联免疫吸附法（ELISA）检测其中S-100B的含量．原位细胞凋亡检测法（TUNEL）检测皮质神经元凋亡情况。通过测定基底动脉血管横截面积判断有无脑血管痉挛（CVS）。结果SAH＋rHuEPO组脑脊液S-100B蛋白含量较SAH组和SAH＋安慰剂组显著性减少（P〈0．05）；TUNEL染色显示SAH＋rHuEPO组皮质神经元凋亡程度较SAH组和SAH＋安慰剂组显著性减轻（P〈0．05）；SAH＋rHuEPO组基底动脉横截面积较SAH组和SAH＋安慰剂组显著性增大（P〈0．01），但小于空白组和对照组（P〈0．01）。结论 早期全身使用rHuEPO能减少兔SAH模型的皮质神经元凋亡,降低脑脊液中的S-100B蛋白含量。并部分缓解CVS,具有明显的脑保护作用。     

骨桥蛋白对大鼠蛛网膜下腔出血后脑血管痉挛的作用

目的探究重组骨桥蛋白(r-OPN)对蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的作用及其可能机制。方法将48只大鼠随机分为假手术+安慰剂组、SAH+安慰剂组、SAH+低剂量rOPN组和SAH+高剂量r-OPN组。采用枕大池二次注血法建立SAH模型。首次注血后72 h取脑脊液,处死大鼠,通过测量基底动脉横截面积和管壁厚度判断脑血管痉挛情况,采用酶联免疫吸附法(ELISA)检测脑脊液中内皮素-1(ET-1)水平,Western blot测定基底动脉磷酸化内皮型一氧化氮合酶(p-e NOS)和诱导型一氧化氮合酶(i NOS)水平。结果与SAH+安慰剂组相比,SAH+高剂量r-OPN组大鼠基底动脉横截面积明显增加,管壁厚度明显减轻,脑脊液ET-1水平明显降低,基底动脉pe NOS表达明显升高,i NOS表达明显降低。结论 r-OPN能有效缓解SAH后CVS,其机制可能与抑制ET-1的产生、降低i NOS的表达,提高p-e NOS的表达有关。     

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.