H2O2对PC12细胞par-4和NF-κBP65基因表达的影响

目的 探讨H2O2对PC12细胞前列腺细胞应答凋亡蛋白-4(prostate apoptosis response-4，par-4)和陔转录因子-κBP65(NF-κBP65)基因表达的影响。方法 用不同终浓度H2O2(0～400nmol／L)处理PC12细胞8h．或终浓度200nmol／l H2O2处理PC12细胞不同时间(0～8h)，采用RT-PCR检测par-4、NF-κBP65 mRNA表达变化．Western blot检测Par-4和NF-κBP65蛋白表达的变化。结果 随H2O2浓度从100～400nmol／L增加，par-4、NF-κBP65 mRNA表达和Par-4、NF-κBP65蛋白表达水平逐渐增加；200nmol／L H2O2作用PC12细胞0～8h，par-4 mRNA表达和Par-4蛋白表达，在2～8h随时间延长表达增加；在0～8h NF-κBP65 mRNA表达和NF-κBP65蛋白表达无明显变化。结论 H2O2可时间、剂量依赖性的增加par-4 mRNA表达和Par-4蛋白表达；H2O2可剂量依赖性的增加NF-κBP65 mRNA表达和NF-κBP65蛋白表达；NF-κBP65 mRNA表达和NF-κBP65蛋白表达无时间依赖性。     

不同浓度氧合血红蛋白对平滑肌细胞核因子-κB DNA结合活性的影响

目的 观察氧合血红蛋白(OxyHb)对培养的血管平滑肌细胞(VSMCs)细胞密度及核因子(NF)-κB的DNA结合活性的影响.方法 用不同浓度(1～100 μmol/L)的OxyHb处理VSMCs,观察其形态学及细胞密度变化,测定NF-κB的DNA结合活性.结果 OxyHb刺激后VSMCs都表现出形态学的改变,其严重程度有浓度依赖性.但是在24 h时只有100 μmol/L组有明显的细胞数量减少,10μmol/L组在48 h时细胞数量开始明显减少.NF-κB的DNA结合活性在经OxyHb处理后明显增高,以10μmol/L及50μmol/L组最高.结论 NF-κB的DNA结合活性在经OxyHb处理的VSMCs中有明显改变,揭示了NF-κB在脑血管痉挛发生时是脑血管平滑肌细胞内重要的信号通路.     

槲皮苷对过氧化氢诱导PC12细胞损伤的保护作用

目的探讨槲皮苷对H2O2所致的PC12细胞凋亡的保护作用及机制。方法 PC12细胞培养后,MTT检测细胞存活率的方法进行H2O2损伤模型的摸索和槲皮苷药物浓度的筛选,将PC12细胞分为对照组、模型组和不同剂量槲皮苷组。用400μmol H2O2刺激PC12神经元细胞使其发生凋亡复制阿尔茨海默病(AD)模型,MTT法检测PC12细胞存活率、硫辛酰胺脱氢酶催化的INT显色反应检测乳酸脱氢酶(LDH)释放量和DAPI荧光核染色观察细胞凋亡形态学改变,Western blot方法检测Cytc和caspase-3表达的变化。结果 400μmol H2O2诱导PC12细胞损伤明显,与模型组比较,槲皮苷组PC12细胞存活率显著提高(P<0.01),凋亡率显著下降(P<0.01),LDH释放量和凋亡相关蛋白Cytc和caspase-3的表达显著减少(P<0.01)。结论槲皮苷可抑制H2O2诱导的PC12细胞凋亡,其机制可能与抑制细胞凋亡线粒体途径中凋亡相关蛋白Cytc和caspase-3的表达有关。     

凝血酶对培养星形胶质细胞的毒性作用研究

目的 探讨凝血酶是否上调体外培养的大鼠星形胶质细胞(As)核转录因子(NF-κB)的表达,及其对细胞增殖的影响.方法 对新生Wistar鼠大脑As体外培养并纯化,经不同浓度(0.1、1、10、100 U/ml)凝血酶干预后,用免疫细胞化学染色和逆转录多聚酶链反应(RT-PCR)检测培养各组As NF-κB mRAN和蛋白的表达;用化学反应法测定培养细胞上清液中乳酸脱氢酶活性(LDH);用MTT法观察不同浓度凝血酶对细胞生长活性的影响;用流式细胞术分析凝血酶对细胞周期和凋亡的影响.结果 与未用凝血酶的对照组比较,各种浓度凝血酶均可引起As NF-κB mRNA水平增加;凝血酶(1、10、100 U/ml)还引起了细胞活性的明显下降;同时导致了培养上清液中LDH活性增高;另外,浓度为100 U/ml的凝血酶,可使细胞阻滞在G2/M期的比例增加.结论 凝血酶能上调体外培养As的NF-κB的表达,降低细胞生长活性,影响细胞生长周期.     

褐藻多糖硫酸酯对6-羟基多巴胺所致MN9D细胞损伤的保护作用及其机制

目的 以6-羟基多巴胺(6-OHDA)为工具药,建立帕金森病(PD)的细胞模型,观察褐藻多糖硫酸酯(Fuc)对细胞模型的保护作用并初步探讨其作用机制.方法 用不同浓度(12.5、25、50、100、200 μmol/L)的6-0HDA处理MN9D细胞24 h,挑选出合适浓度50 μmol/L.再以50μmol/L 6-OHDA处理MN9D细胞不同时间(6、12、24及48 h),建立细胞损伤模型,挑选出合适时间24h.用0.01、0.1、1.0mg/mL Fuc预孵育MN9D细胞1 h后加入50μmol/L 6-OHDA共同作用24h,以探讨Fuc的保护作用.MTT法检测细胞存活率,生化法测定乳酸脱氢酶(LDH)释放量,二氯荧光索乙二酯(DCF-DA)染色法检测细胞内的氧化应激水平.结果 随着6-OHDA浓度增加或作用时间延长,MN9D细胞MTT值逐渐降低.50 μmol/L6-OHDA处理细胞24 h,MTT值明显下降,LDH释放量增加.而0.1、1.0mg/mL的Fuc预孵育1 h可明显减轻MN9D细胞的损伤,提高MTT值并降低LDH释放量,细胞形态学改变与生化实验结果一致.50 μmol/L6-OHDA作用8h可明显升高MN9D细胞内的氧化应激水平,而1.0mg/mL的Fuc预处理1 h可以拮抗6-OHDA引起的细胞内氧化应激水平增高.结论 Fuc可以有效的拮抗6-OHDA对MN9D细胞的损伤作用,其作用机制可能与抗氧化活性有关.     

咪唑克生对脂多糖诱导的皮质星形胶质细胞相关炎症细胞因子的影响

目的：了解咪唑克生（Ida）对炎症状态下的星形胶质细胞相关的炎症细胞因子的调节作用。方法：将纯度〉95％星形胶质细胞随机分为空白对照组、脂多糖刺激组和Ida炎症干预组，每组7瓶细胞。Ida 100μmol·L^-1，脂多糖10μg·mL^-1。Ida预处理6h、药物共处理12h、脂多糖处理12和24h时留上清液检测细胞因子，细胞提取RNA检测胶质酸性纤维蛋白和核转录因子κB（NF-κB）水平。结果：Ida能抑制促炎细胞因子（P〈0．01）和NF-κB的表达（P〈0．05）。结论：Ida具有抗炎作用。     

槲皮素对氧化应激大鼠星形胶质细胞的保护作用

目的 研究槲皮素对氧化应激损伤后大鼠星形胶质细胞的保护作用. 方法 采用终浓度为2 mmol/L的H2O2作用于体外原代培养的大鼠胶质细胞6 h,以诱导氧化应激.实验分为正常对照组、H2O2组、槲皮素+H2O2组.不同浓度(0、50、100、200μmol/L)槲皮素预处理24h后,应用速率法和LIVE/DEAD检测试剂盒分别检测氧化应激胶质细胞的乳酸脱氢酶(LDH)释放率以及细胞存活率的变化. 结果 终浓度为2 mmol/L的H2O2作用6 h即可造成细胞损伤,LDH释放率由对照组的(3.89±1.89)%增至(90.27±2.68)%,较对照组明显增多,细胞存活率由对照组的(99.25±0.08)%降至(59.73%±9.92)%,较对照组明显降低,差异均有统计学意义(P<0.05).槲皮素预处理后细胞LDH释放率降低,50、100、200 μmol/L浓度的槲皮素组LDH释放率分别减少到(48.19±13.98)%、(27.81±9.33)%和(18.13±8.28)%,与H2O2组比较差异有统计学意义(P<0.05);槲皮素预处理同时能提高细胞存活率,50、100、200 μmol/L浓度的槲皮素组细胞存活率分别提高至(86.80±3.62)%、(88.32±5.77)%和(91.18±3.03)%,与H2O2组比较差异均有统计学意义(P<0.05). 结论 槲皮素预处理对氧化应激大鼠胶质细胞有一定的保护作用.     

人工合成多肽FGL对神经细胞模型PC12细胞增殖与凋亡的影响**★

背景: FGL是NCAM的核心活性多肽片段，可直接作用于成纤维细胞生长因子受体1，激活NCAM的信号传导途径。 目的：观察FGL人工合成多肽联合培养对PC12细胞增殖和凋亡的作用。 方法：将培养的PC12细胞分为对照组和实验组，实验组预先加入1%的FGL多肽溶液。分别于培养1，3，5，7，9 d采用细胞计数试剂8法检测细胞增殖情况。将PC12细胞分为正常组、实验组和损伤组，损伤组加入H2O2刺激16 h。实验组加入H2O2与FGL人工合成多肽刺激16 h，流式细胞仪检测细胞凋亡，荧光定量PCR法检测PC12中的核转录因子κB mRNA表达。 结果与结论：FGL人工合成多肽与PC12复合培养细胞生长良好，可明显促进PC12细胞的活性并且减低PC12 细胞凋亡并可明显降低凋亡模型中PC12细胞核转录因子κB基因的表达。说明FGL多肽可以明显促进PC12细胞增殖，并可以抑制PC12细胞凋亡。     

电离辐射对人脑胶质瘤细胞NF-κB信号通路的作用及其机制

目的探讨电离辐射对人脑胶质瘤细胞核转录因子κB(NF-κB)通路的作用及机制。方法电离辐射(ionizing radiation,IR)诱导人胶质母细胞瘤T98G细胞(T98G细胞)DNA损伤;划痕、甲基噻唑蓝(MTT)比色实验及流式细胞仪检测细胞增殖及凋亡;Bay-11处理抑制NF-κB活性;双荧光素酶报告系统检测NF-κB的活性;免疫荧光检测p65的亚细胞定位。结果电离辐射不抑制T98G细胞增殖,不诱导其凋亡;抑制NF-κB的活性增强T98G细胞对电离辐射的敏感性;电离辐射能激活T98G细胞中NF-κB信号通路。结论电离辐射能激活T98G细胞的NF-κB信号通路。抑制NF-κB可增强T98G细胞对电离辐射的敏感性。     

雷沙吉兰(Rasagiline)对Aβ25-35诱导PC12细胞凋亡的防护作用

目的探讨雷沙吉兰(Rasagiline)对β-淀粉样蛋白(Aβ)诱导PC12细胞损伤阿尔茨海默病(AD)模型的保护作用及其机制。方法不同浓度的Aβ25-35(1μmol/L,10μmol/L,20μmol/L)作用于PC12细胞48h,MTT法检测细胞存活率,选用使细胞存活率降低到64%的Aβ浓度20μmol/L。用不同浓度的雷沙吉兰(0.1μmol/L,1μmol/L,10μmol/L)预孵育PC12细胞1h,再加入20μmol/L的Aβ共孵育48h,再测MTT活性,并用荧光染料丫啶橙和溴化乙啶染色,在荧光显微镜下计数凋亡细胞检测凋亡细胞百分率。结果Aβ在20μmol/L时使PC12细胞存活率降低至64%,与对照组差异显著,1μmol/L的雷沙吉兰可显著提高细胞存活率至85%。对照组细胞凋亡率为2%,20μmol/L Aβ作用48h后,PC12细胞凋亡率达13%,1μmol/L的雷沙吉兰使20μmol/L Aβ诱导的PC12细胞凋亡率下降到5%。结论雷沙吉兰对Aβ引起的PC12细胞损伤具有明显的保护作用,其机制可能与抑制Aβ诱导的凋亡有关。     

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.