脑缺血再灌注损伤时 c-fos、c-jun 的表达和细胞凋亡

目的　研究脑缺血再灌注大鼠神经细胞凋亡和原癌基因c fos、c jun表达。 方法　 8周龄健康雄性Wistar大鼠 2 4只 ,随机分为缺血再灌注组、假手术组和对照组 ,每组各 8只。制作大鼠大脑中动脉栓塞 (MCAO)再灌注模型 ,缺血 4h再灌注 2h后断头处死 ,TUNEL法检测神经细胞凋亡 ,免疫组织化学法检测神经细胞c fos、c jun蛋白的表达。结果　缺血再灌注组细胞凋亡率、平均吸光度及c fos、c jun阳性细胞率、平均吸光度均高于假手术组和对照组 (P <0 .0 5 )。结论　脑缺血再灌注损伤可诱导c fos、c jun蛋白的表达和细胞凋亡 ;脑缺血再灌注大鼠神经功能评分与c fos、c jun蛋白的表达和细胞凋亡呈正相关。     

乌司他丁对脑缺血-再灌注大鼠脑组织细胞色素C、凋亡诱导因子表达及凋亡细胞数的影响

目的探讨乌司他丁对脑缺血-再灌注大鼠脑组织细胞色素C、凋亡诱导因子(AIF)表达及凋亡细胞数的影响。方法 54只SD大鼠随机分成假手术组、脑缺血-再灌注组(对照组)、脑缺血-再灌注+乌司他丁治疗组(治疗组)。采用大脑中动脉线栓法制作大鼠局灶性脑缺血-再灌注损伤模型。治疗组再灌注时,腹腔注射乌司他丁2万U/kg。采用免疫组化法检测大鼠脑组织细胞色素C表达,采用逆转录(RT)-PCR法检测大鼠脑组织AIF表达,采用原位末端标记法检测大鼠脑组织凋亡细胞数。结果对照组和治疗组大鼠脑组织皮质区细胞色素C、AIF的表达及凋亡细胞数均明显高于假手术组(均P<0.05),但治疗组大鼠脑组织皮质区细胞色素C、AIF的表达及凋亡细胞数明显低于对照组(均P<0.05)。结论乌司他丁抑制细胞凋亡可能与下调脑缺血-再灌注大鼠脑组织细胞色素C、AIF的表达,减轻线粒体损伤,抑制线粒体通路的凋亡途径有关。     

人尿激肽原酶对大鼠局灶性脑缺血再灌注损伤的保护作用及对Caspase-3表达的影响

目的 观察人尿激肽原酶(HUK)对局灶性脑缺血再灌注损伤大鼠神经细胞凋亡及Caspase-3表达的影响. 方法 66只SD大鼠按随机数字表法分为假手术组(n=6)、缺血再灌注损伤组和HUK处理组,后两组又按不同观察时间点分为再灌注6h、12h、24 h、72 h、168 h共5个亚组(n=6).缺血再灌注损伤组和HUK处理组采用线栓法建立大鼠大脑中动脉局灶性脑缺血再灌注损伤模型,HUK处理组按浓度17.5×10-3PNAU/mL,1.0 mL/kg,于再灌注后3h尾静脉注射给药,1次/d.采用TUNEL法及免疫组化染色检测各组大鼠脑组织中凋亡细胞及Caspase-3阳性细胞的数量变化. 结果 脑缺血再灌注损伤后6h即有细胞凋亡,于24 h达到高峰,至168 h仍可见凋亡细胞.Caspase-3阳性细胞表达均于再灌注24 h达高峰,至168 h仍有较多表达.除168 h时间点外,其余各时间点HUK处理组大鼠神经细胞凋亡数量、Caspase-3阳性细胞数量均明显低于缺血再灌注损伤组,差异均有统计学意义(P＜0.05). 结论 HUK在大鼠局灶性脑缺血再灌注损伤早期(6～72h)时能抑制细胞凋亡,推测与其减少Caspase-3的表达有关.     

依达拉奉对脑缺血再灌注损伤保护作用机制的研究

目的 探讨依达拉奉对脑缺血再灌注损伤的保护机制.方法 将45只健康雄性Wistar大鼠随机分为假手术组、生理盐水对照组、依达拉奉干预组各15只,采用线栓法制作大鼠大脑中动脉缺血模型,脑缺血2h再灌注即刻及12h干预组给予依达拉奉3mr/kg,对照组给予等量生理盐水分别腹腔注射.于24h后断头取脑,免疫组化法测细胞色素C(Cyt C)、半胱氨酸蛋白酶-3(Caspase-3),TUNEL法检测神经细胞凋亡,化学比色法测MDA、SOD,TTC染色测梗死体积.结果 假手术组无梗死现象,免疫反应阳性细胞及凋亡细胞亦少见.依达拉奉十预组与生理盐水对照组相比,Cyt C阳性细胞数、Caspase-3阳性细胞数及凋亡细胞数均明显减少,MDA含量减少,SOD活性有所恢复,差异均有统计学意义.生理盐水对照组可见明显大脑中动脉供血区梗死灶,依达拉奉干预组亦可见到梗死灶,与对照组比梗死体积占全脑体积的百分比明显缩小(t=6.576,P＜0.01).结论 依达拉奉有自由基清除作用,减少了Cyt C的释放,抑制了细胞凋亡,并缩小了梗死体积;依达拉奉可能通过线粒体途径抑制细胞凋亡.对脑缺血再灌注损伤有保护作用.     

联合应用骨髓基质细胞与bcl-2基因对脑缺血大鼠的神经保护作用

目的 探讨联合应用骨髓基质细胞(MSC)与bcl-2基因对大鼠脑缺血再灌注损伤后神经细胞凋亡和细胞色素C蛋白表达的影响.方法 采用改良线栓法制成大脑中动脉闭塞大鼠模型.将30只Wistar大鼠随机分为空白对照组、MSC组及MSC+bcl-2组3组,每组10只.MSC+bcl-2组于大鼠脑缺血再灌注3 h后经颈动脉注入pLXSN-bcl-2质粒,MSC组及MSC+bcl-2组于大鼠脑缺血再灌注24 h后经尾静脉植入MSC.各组于再灌注后7 d进行神经功能评分,采用免疫组化法检测脑组织细胞色素C蛋白表达,通过TUNEL法检测细胞凋亡情况.结果 再灌注7 d后,MSC组和MSC+bcl-2组大鼠神经功能缺损评分明显低于空白对照组(P<0.05),MSC+bcl-2组大鼠神经功能评分明显低于MSC组(P<0.05);MSC组和MSC+bcl-2组大鼠细胞色素C免疫反应阳性细胞较空白对照组明显减少(P<0.05),MSC+bcl-2组大鼠细胞色素C免疫反应阳性细胞较MSC组明显减少(P<0.05);空白对照组大鼠缺血侧凋亡细胞明显多于MSC组和MSC+bcl-2组(P<0.05),MSC+bcl-2组大鼠凋亡细胞明显少于MSC组(P<0.05).结论 MSC和bcl-2基因联合治疗脑缺血大鼠可下调其组织细胞色素C表达及抑制神经细胞凋亡,促进大鼠神经功能恢复.     

银丹心脑通对脑缺血再灌注大鼠海马区神经细胞凋亡及Caspase-3表达的影响

目的 明确银丹心脑通对脑缺血再灌注时神经细胞凋亡的保护作用,探索其治疗缺血性脑卒中的分子作用机制. 方法 将40只SD雄性大鼠按随机数字表法分为假手术组、模型组、阳性对照组(尼莫地平组)、银丹心脑通组.尼莫地平组及银丹心脑通组预先连续灌胃给药7d,假手术组和模型组每日灌服相当量的蒸馏水,第8大制备大鼠大脑中动脉阻塞模型.脑缺血再灌注24 h后应用TUNEL法检测各组大鼠海马CA1区凋亡阳性神经细胞数,应用免疫组化染色测定各组大鼠脑组织中天冬氨酸特异性半胱氨酸蛋白酶-3(Caspase-3)的表达. 结果 模型组大鼠均能见到较多的凋亡阳性细胞数及Caspase-3阳性细胞数,与假手术组比较差异有统计学意义(P＜0.05);与模型组比较,银丹心脑通组、尼莫地平组能明显减小凋亡阳性细胞数及Caspase-3阳性细胞数,差异有统计学意义(P＜0.05);银丹心脑通组与尼莫地平组在凋亡阳性神经细胞数及Caspase-3阳性细胞数上比较差异无统计学意义(P＞0.05). 结论 银丹心脑通对脑缺血再灌注损伤有一定保护作用,能够减少脑缺血再灌注大鼠神经细胞的凋亡,其作用机制可能与减少脑组织中Caspase-3的表达有关.     

吸氧预处理对大鼠局灶性脑缺血再灌注损伤后神经细胞凋亡及CHOP/GADD153表达研究

目的研究吸氧预处理(oxygen inhalating precondition,OIP)对大鼠局灶脑缺血再灌注后内质网应激反应(Indoplasmic recticulum stress,ERS)导致的细胞凋亡及凋亡相关基因生长停滞及DNA损伤基因153(C/EBPhomologous protein/growth arrest and DNA damage-inducible gene 153,CHOP/GADD153)的关系,探讨OIP的脑保护作用。方法采用线栓法阻塞大鼠大脑中动脉制作局灶脑缺血再灌注模型:(1)Tunel法标记神经细胞凋亡;(2)免疫组化染色法和western-blot法观察GADD153蛋白含量。结果与模型组比较,OIP组海马CA1区的凋亡细胞率明显下降(P<0.05),GADD153阳性细胞平均灰度值和蛋白含量相对值均明显下降(P<0.05)。结论 OIP可通过抑制缺血再灌注后神经细胞凋亡和减少GADD153蛋白的表达发挥脑保护作用。     

川芎嗪、黄芪对脑缺血再灌注后神经细胞凋亡及Fos蛋白表达的影响

目的探讨川芎嗪、黄芪对脑缺血再灌注后神经细胞凋亡及Fos蛋白表达的影响.方法48只雄性SD大鼠,随机等分成4组,每组12只.A组:假手术组;B组:生理盐水对照组;C组:川芎嗪治疗组;D组:黄芪治疗组.采用TUNEL法及免疫组化法分别检测各组大鼠脑组织神经细胞凋亡及Fos蛋白的表达.结果与A组比较,B组大鼠神经细胞凋亡数目及Fos蛋白阳性细胞数目增多,Fos蛋白阳性细胞平均灰度值下降(P＜0.01);与B组比较,C组、D组大鼠神经细胞凋亡数目及Fos蛋白阳性细胞数目下降,Fos蛋白阳性细胞平均灰度值升高(P＜0.01).结论川芎嗪、黄芪均可能通过抑制脑缺血再灌注后Fos蛋白表达而减少神经细胞凋亡.     

大鼠脑缺血预处理对额叶神经细胞凋亡和P53蛋白表达的影响

目的探讨大鼠短暂性全脑缺血预处理对再次脑缺血额叶神经细胞凋亡和P53蛋白表达的影响.方法采用改良的Pulsinelli 4血管阻断(4VO)方法,建立SD大鼠急性全脑缺血及预处理模型.雄性SD大鼠随机分为三组预处理对照组,给予3min全脑缺血;预处理缺血组,先给予3min全脑缺血,48h后在给予全脑缺血15min;缺血组,仅给予全脑缺血15min.采用TUNEL方法观察额叶神经细胞凋亡,SP免疫组化方法检测P53蛋白的表达.结果预处理对照组未见TUNEL阳性细胞,仅见个别P53蛋白阳性细胞.预处理缺血组与缺血组相比,再灌注后48h、72h及7d额叶TUNEL阳性细胞数显著减少(P《0.01).预处理缺血组与缺血组相比,再灌注后48h、72h及7d额叶P53阳性细胞数显著减少(P《0.01).结论全脑缺血15 min后额叶神经细胞凋亡和P53蛋白表达增多.全脑缺血预处理能减少额叶缺血再灌注后神经细胞凋亡和P53蛋白的表达.     

人工合成E-选择素对大鼠局灶性脑缺血再灌注损伤中血管细胞黏附分子-1及其mRNA表达的影响

目的探讨人工合成E-选择素对大鼠局部脑缺血再灌注损伤脑组织中血管细胞黏附分子-1(VCAM-1)及其mRNA表达的影响。方法采用改良的Zea Longa法建立脑缺血再灌注损伤模型,60只雄性SD大鼠随机分为模型组、假手术组和治疗组。采用免疫组化法观察缺血区脑组织中微血管VCAM-1阳性细胞数,RT-PCR法观察其mRNA表达。结果①模型组VCAM-1阳性细胞在再灌注2 h后开始出现,并持续增多,24 h后达高峰,72 h开始下降,各时间点比假手术组明显增多(P<0.01);VCAM-1 mRNA在再灌注2 h后开始表达,12 h后达高峰,24 h开始降低,各时间点比假手术组明显增高(P<0.01)。②假手术组VCAM-1阳性细胞数少见,VCAM-1 mRNA表达水平低。③治疗组(24 h)VCAM-1阳性细胞数比假手术组增多(P<0.05),但较模型组少(P<0.05);VCAM-1 mRNA表达比假手术组高(P<0.05),但较模型组低(P<0.05)。结论大鼠局灶性脑缺血再灌注损伤后,VCAM-1及VCAM-1 mRNA表达增多;人工合成E-选择素可降低VCAM-1及VCAM-1 mRNA的表达从而抑制白细胞与血管内皮细胞黏附,减轻炎症反应和脑缺血再灌注损伤,发挥脑保护作用。     

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.     

Special Pharmacokinetic Considerations in Children

Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection.