依达拉奉对大鼠脑外伤后细胞凋亡率及Bcl-2／Bax表达的影响

目的研究依达拉奉对大鼠脑外伤（TBI）后细胞凋亡率及Bcl-2／Bax表达的影响,探讨其对脑外伤后脑组织损害的保护作用。方法成年SD大鼠36只随机分为假手术组、脑外伤组、依达拉奉组。Allen＇s改良法制作脑外伤的模型;流式细胞仪检测伤侧海马细胞凋亡率的变化,免疫组化法检测海马细胞Bcl-2和Bax蛋白的表达,图象分析仪进行灰度定量分析。结果假手术组没检测到明显的细胞凋亡;脑外伤组检测到较高的细胞凋亡率;依达拉奉组细胞凋亡率较外伤组明显下降。外伤组脑细胞Bcl-2、Bax蛋白表达水平均明显高于假手术组;与外伤组相比,依达拉奉组Bcl-2蛋白表达水平显著增高,Bax蛋白表达水平明显下降。结论依达拉奉可有效抑制大鼠外伤后神经细胞凋亡,此作用可能与其有效清除氧自由基、上调Bcl-2和下调Bax蛋白表达水平有关。     

自由基清除剂预处理对大鼠脑缺血再灌注损伤后脑组织细胞凋亡及其相关蛋白表达的影响

目的探讨自由基清除剂依达拉奉预处理对大鼠脑缺血再灌注损伤后神经细胞凋亡及其相关蛋白Bcl-2、Bax、热休克蛋白70(HSP70)表达的影响。方法将45只雄性SD大鼠随机分为假手术组、对照组、依达拉奉预处理组,每组15只。采用线栓法制作大鼠缺血2h再灌注24h模型。预处理组大鼠建模前12h腹腔注射依达拉奉(3mg/kg),对照组给予等容量生理盐水。再灌注24h后断头取脑,应用免疫组织化学法检测Bcl-2、Bax、HSP70蛋白表达,末端脱氧核糖核酸转移酶介导的原位缺口末端标记法检测凋亡细胞。结果依达拉奉预处理组和对照组大鼠缺血周围脑组织中凋亡细胞和Bcl-2、Bax及HSP70阳性细胞数比假手术组均明显增加(P<0.01);与对照组比较,其凋亡细胞和Bax阳性细胞数均明显减少(P<0.01),而Bcl-2和HSP70阳性细胞数明显增加(P<0.01)。结论细胞凋亡在缺血再灌注损伤中起着重要作用;依达拉奉可能通过上调Bcl-2、HSP70蛋白表达、下调Bax蛋白表达减轻大鼠脑缺血再灌注后的细胞凋亡,增加脑缺血再灌注损伤耐受性,从而起到神经保护作用。     

亚低温对大鼠脑创伤后海马区凋亡相关蛋白表达的影响

目的观察亚低温对大鼠创伤性脑损伤(TBI)后海马CA3区细胞凋亡及相关蛋白Bcl-2、Bax及Caspase-3表达的影响,探讨亚低温脑保护的分子生物学机制.方法将大鼠随机分成假手术、单纯脑损伤和脑损伤后亚低温治疗3组,应用改良Marmarou方法制作大鼠TBI模型,分别用流式细胞仪(FCM)和免疫组化法检测各组动物脑海马CA3区细胞凋亡率和Bcl-2、Bax及Caspase-3蛋白的表达.结果与假手术组相比,大鼠TBI后海马CA3区细胞凋亡率及Caspase-3表达增高(P<0.05),Bcl-2/Bax表达比下降(P<0.05).亚低温治疗后,大鼠脑海马CA3区细胞凋亡率及Caspase-3表达较单纯脑损伤组降低(P<0.05),而Bcl-2/Bax表达比升高(P<0.05).结论亚低温对TBI的脑保护作用机制可能与干预伤后凋亡相关基因表达并减少神经细胞凋亡有关.     

依达拉奉对阿尔茨海默病模型大鼠认知损害的保护作用和脑内Bcl-2表达的影响

目的:观察依达拉奉对双侧脑室内注射链脲菌素(ICV-STZ)诱导的阿尔茨海默病(AD)模型大鼠认识功能的影响,并探讨其作用机制。方法:48只成年雄性SD大鼠随机分为4组：假手术组(S)、依达拉奉+假手术组(E+S)、模型组(L)、依达拉奉+制模组(E+L)。Morris水迷宫测试各组大鼠认知功能;比色法检测各组大鼠海马和皮质的超氧化物歧化酶(SOD)、丙二醛(MDA)含量;免疫组织化学法检测大鼠海马和皮质的Bcl-2表达。结果: Morris水迷宫测试中,与S组比较,L组大鼠目标象限停留时间显著减少(P＜0.05),潜伏期显著延长(P＜0.05);E+L组比L组目标象限停留时间显著增加(P＜0.05),潜伏期显著缩短(P＜0.05)。E+L组与L组比较,脑内SOD含量显著增加(P＜0.05),MDA含量显著减少(P＜0.05)。免疫组织化学染色显示,与L组比较,E+L组Bcl-2表达阳性率显著增高(P＜0.05)。结论:依达拉奉能够保护STZ诱导的AD模型大鼠的认知损害,其机制可能是改善大鼠脑内氧化应激和减少神经细胞凋亡。     

局灶性脑缺血再灌注大鼠海马CA1区神经元凋亡研究

目的 观察大鼠局灶性脑缺血再灌注(ischemia reperfusion,I/R)损伤后海马CA1区神经元凋亡、TUNEL阳性细胞变化,以及凋亡相关蛋白Bcl-2与Bax蛋白的表达情况.方法 将健康雄性SD (Sprague-Dawley)大鼠随机分为假手术组和I/R组,每组再分为缺血再灌注后3、6、12、24、48、72 h亚组.应用免疫组化方法检测再灌注后不同时间点大鼠海马CA1区神经元凋亡基因Bcl-2和Bax蛋白的表达及Bcl-2/Bax比值变化,采用原位细胞凋亡检测(TUNEL)技术检测凋亡阳性细胞数.结果 各组非缺血侧相应区域神经元胞质中Bcl-2均有微弱表达.I/R组缺血侧海马CA1区于再灌注3 h开始出现Bcl-2和Bax蛋白微弱表达,随再灌注时间延长神经元内Bcl-2表达逐渐增强,再灌注24 h后Bcl-2表达达高峰,假手术组与I/R组比较差异有统计学意义(P<0.05).结论 I/R损伤后海马CA1区神经元不仅存在变性坏死,还存在明显的细胞凋亡且细胞凋亡在大鼠I/R损伤中发挥重要作用;I/R可诱导海马CA1区细胞凋亡基因Bcl-2和Bax蛋白表达,且其表达呈一定规律.     

依达拉奉后处理对氧糖剥夺SK-N-SH细胞的抗凋亡作用及对Bcl-2与Bax表达的影响

目的观察依达拉奉后处理(EPC)对氧糖剥夺损伤SK-N-SH细胞的抗凋亡作用及对Bcl-2与Bax表达的影响,探讨其可能的机制。方法细胞分为正常对照组、氧糖剥夺组(OGD组)、依达拉奉后处理组(EPC组)。正常对照组DMEM高糖培养液中正常培养;OGD组的SK-N-SH细胞换用无糖DMEM培养液并置入自制缺氧罐处理4 h,再换成DMEM高糖培养液继续培养20 h;EPC组的SK-N-SH细胞先氧糖剥夺4 h,然后用含终浓度1μmol/L依达拉奉的DMEM高糖培养液作为后处理4 h后,再换成DMEM高糖培养基继续培养16 h。四甲基偶氮唑蓝(MTT)法检测细胞存活率,Hoechst33258染色检测细胞凋亡,Western blot检测Bcl-2与Bax蛋白的表达。结果 OGD组存活率比正常组明显下降(P<0.01),EPC组细胞存活率比OGD组显著增加(P<0.05);OGD组细胞凋亡率较正常组显著增高(P<0.01),而EPC组细胞凋亡率显著低于OGD组(P<0.05);与OGD组比较,EPC组Bcl-2表达显著增高(P<0.05),而Bax的表达明显降低(P<0.05)。结论依达拉奉后处理对氧糖剥夺SK-N-SH细胞有抗凋亡作用,可能与其使Bcl-2过表达和抑制Bax表达有关。     

依达拉奉对海人酸致痫大鼠海马神经元抗氧化应激能力的影响

目的本实验观察依达拉奉对海人酸(KA)致痫大鼠海马神经元抗氧化应激能力的影响。方法选用成年健康雄性Wistar大鼠66只,体质量240±20g,实验动物随机分为3组:1假手术组(n=6)右侧海马CA3区注入等量的生理盐水;2KA模型组(n=30):右侧海马CA3区注入KA 4μg·kg-1(4μg·μl-1)。3依达拉奉组(n=30):右侧海马CA3区注入KA 4μg·kg-1(4μg·μl-1)后,即刻给予依达拉奉10mg.kg-1.d-1腹腔注射。模型组和依达拉奉组均设定5个时间点,分别为5min、6h、24h、72h、7d,每个时间点6只大鼠,于预订的时间点断头取脑,分离左侧海马,检测脑组织中超氧化歧化酶(SOD)、丙二醛(MDA)含量。结果假手术组各个时间点SOD活性及MDA含量均无明显变化(P>0.05);模型组于KA注射后6h可见SOD活性下降,MDA开始升高,于3d SOD活性降至最低(P<0.01),MDA升至最高(P<0.01),随后SOD活性开始回升,MDA开始下降,于7d时SOD活性恢复至基线水平;依达拉奉组于6⁷2h时间段内SOD活性明显高于模型组(P<0.01或P<0.05),MDA含量明显低于模型组(P<0.01或P<0.05)。结论依达拉奉有效地升高KA致痫大鼠海马神经元的SOD活性并降低MDA生成,从而提高机体的抗氧化应激能力,减轻神经元的损伤,对神经元具有保护作用。     

依达拉奉对局灶性脑缺血再灌注损伤大鼠caspase-3、Bcl-2表达的影响

目的 对局灶性脑缺血再灌注损伤大鼠,给予自由基清除剂依达拉奉后,观察再灌注不同时间点脑组织caspase-3和Bcl-2蛋白表达情况,探讨依达拉奉对脑缺血再灌注损伤的保护作用.方法 制作局灶性脑缺血再灌注模型.随机分为正常组、假手术组、脑缺血组、依达拉奉组.假手术组于术后,脑缺血组和依达拉奉组于缺血1h后再灌注2h、6h、12h、24h、48h不同时间点,依达拉奉组于再灌注后30min腹腔内及皮下各注射依达拉奉1 次(3mg/kg.wt),30min 后重复1次.按时间点处死大鼠,灌注固定、取脑,行免疫组化染色,观察和计数不同脑区的caspase-3和Bcl-2蛋白表达阳性细胞数.结果 脑缺血组再灌注后2h在大脑额、顶叶皮质和海马均可见到caspase-3和Bcl-2阳性细胞,caspase-3表达高峰在12h;Bcl-2表达高峰在6h.依达拉奉组各时间点caspase-3阳性细胞较脑缺血组明显减少,而Bcl-2阳性细胞数明显增加 (均为P＜0.05).结论 依达拉奉可抑制caspase-3,提高Bcl-2的蛋白表达,对脑缺血再灌注损害有明显的保护作用.     

胰岛素联合依达拉奉治疗对实验性蛛网膜下腔出血后脑血管痉挛的影响

目的 探讨胰岛素联合依达拉奉治疗对实验性蛛网膜下腔出血(SAH)后脑血管痉挛(CVS)的影响.方法 健康新西兰白兔40只,随机分为假手术组(8只)、SAH组(10只)、胰岛素组(10只)、胰岛素+依达拉奉组(12只).采用兔枕大池2次注血法建立SAH模型.第1次注血后30 min,胰岛素组及胰岛素+依达拉奉组皮下注射胰岛素0.2 U/kg,每日3次,共7 d;同时,胰岛素+依达拉奉组经耳缘静脉推注依达拉奉注射液0.5 mg/kg,每日2次,共7 d.制模第7 d测量各组基底动脉横截面积以评估CVS的程度,观察基底动脉的病理学变化;免疫组化染色测定血管内皮细胞胰岛素受体(InRa)的表达.结果 胰岛素+依达拉奉组基底动脉横截面积[(0.46±0.3)mm2]与假手术组[(0.48±0.4)mm2]比较差异无统计学意义;SAH组[(0.25±0.3)mm2]及胰岛素组[(0.30±0.3)mm2]明显小于假手术组(均P<0.05);与假手术组比较,血管内皮细胞InRa在SAH组和胰岛素组的表达明显下调(均P<0.05);胰岛素+依达拉奉组与假手术组比较差异无统计学意义.病理学观察显示:假手术组内皮细胞光滑,血管壁无增厚;SAH组及胰岛素组血管壁明显增厚,内皮细胞皱缩;胰岛素+依达拉奉组管壁稍厚,内皮细胞舒展无皱缩.结论 胰岛素与依达拉奉联合运用可有效缓解兔实验性SAH后的CVS.     

丁苯酞联合依达拉奉治疗急性缺血性脑卒中对细胞凋亡的影响

目的探讨丁苯酞注射液联合依达拉奉对急性缺血性脑卒中的临床疗效及对细胞凋亡的影响。方法选择急性脑梗死患者136例,随机分为联合用药组和依达拉奉组,每组68例。依达拉奉组给予依达拉奉注射液治疗,联合用药组在依达拉奉组治疗的基础上加用丁苯酞,共治疗14 d。比较治疗前后NIHSS、ADL评分,测定细胞脂质过氧化水平及抗氧化酶活性及血清Bax、Bcl-2含量。结果联合用药组治疗后NIHSS评分低于依达拉奉组,ADL评分高于依达拉奉组,丙二醛(MDA)、超氧化物歧化酶(SOD)水平低于依达拉奉组(P0.05);联合用药组治疗后血清Bax含量低于依达拉奉组,血清Bcl-2含量高于依达拉奉组(P0.05)。结论丁苯酞注射液联合依达拉奉治疗急性缺血性脑卒中,可减轻缺血再灌注过程中氧化应激反应及细胞凋亡,从而减轻脑缺血再灌注(I/R)所引起的脑损伤。     

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.     

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.     

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.     

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.     

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.     

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.