丹参酮ⅡA对星形胶质细胞细胞周期和增殖的影响

目的探讨丹参酮ⅡA对体外培养星形胶质细胞细胞周期和增殖的影响。方法本研究采用体外细胞培养方法获得新生SD小鼠大脑皮质星形胶质细胞,然后在培养液中分别加入不同浓度的丹参酮ⅡA,作用8 h及24 h后,通过流式细胞仪检测丹参酮ⅡA对星形胶质细胞细胞周期的影响。结果丹参酮ⅡA作用于星形胶质细胞后,可引起细胞周期的显著变化,表现为G0/G1期细胞数减少,S期、G2/M期细胞数增多。结论丹参酮ⅡA可促进体外培养的星形胶质细胞增殖。     

Tamoxifen对星形胶质细胞增殖的作用

目的观察体积调节性阴离子通道阻滞剂Tamoxifen对体外培养星形胶质细胞增殖的的影响。方法采用原代培养的大鼠大脑皮层星形胶质细胞,实验分为对照组(正常培养基培养)与Tamoxifen干预组;在不同时间点(0h、12h、24h、48h),应用流式细胞技术以及免疫细胞荧光双标法(Brdu/DAPI)检测各实验组星形胶质细胞增殖及细胞周期进展的情况。结果与对照组相比,Tamoxifen干预组在12h、24h时星形胶质细胞增殖率较正常对照组降低(P0.05);处于S期细胞的百分率相对正常对照组明显下降,处于G0-G1期细胞的百分率较正常组增高(P0.01)。结论体积调节性阴离子通道阻滞剂Tamoxifen可以显著抑制体外培养星形胶质细胞增殖及细胞周期进展,提示VRAC参与了体外培养星形胶质细胞的增殖。     

脱氢异雄酮对大鼠星形胶质细胞CD80、CD86和MHC-Ⅱ分子表达及其细胞增生影响的研究

目的　探讨脱氢异雄酮 ( dehydroepiandrosterone,DHEA)对大鼠星形胶质细胞 CD80、CD86和 MHC- 分子表达及其细胞增生的影响。方法　用 2、1 0、5 0 μg/m L DHEA处理体外培养的新生 Lewis大鼠星形胶质细胞后 ,应用流式细胞仪检测星形胶质细胞表面 CD80、CD86和 MHC- 分子表达 ,用液体闪烁计数器测定掺入星形胶质细胞内3H-甲基 -胸腺嘧啶核苷。结果　不同浓度的 DHEA可降低大鼠星形胶质细胞 CD86分子表达 ,5 0μg/m L DHEA可降低星形胶质细胞的增生。结论　 DHEA可能通过降低星形胶质细胞表面 CD86共刺激分子的表达抑制中枢神经系统内的免疫反应 ,高浓度的 DHEA可降低星形胶质细胞的增生。     

异甘草素联合替莫唑胺对SHG44人脑胶质瘤干细胞增殖的影响

目的探讨异甘草素联合替莫唑胺对SHG44人脑胶质瘤干细胞增殖的影响。方法采用含无血清达尔伯克氏改良伊格尔氏培养基(DMEM/F12)(含表皮生长因子(EGF)、成纤维细胞生长因子(FGF)、B27)的悬浮细胞培养板培养、纯化胶质瘤干细胞,并通过CD133联合Nestin标记进行免疫荧光鉴定;实验分为对照组[含二甲基亚砜(DMSO)]、异甘草素(5~160μmol/L)组、替莫唑胺(12.5~200μmol/L)组、异甘草素+替莫唑胺组(160μmol/L+12.5~200μmol/L),通过细胞增殖-毒性检测(CCK-8)法、流式细胞术、免疫荧光染色法分别检测细胞抑制率、细胞周期及干细胞表面相关分化蛋白表达情况。结果异甘草素随着浓度增加细胞抑制作用越强,且160μmol/L时抑制率达32%,替莫唑胺随着浓度增加抑制作用越强,且200μmol/L时抑制率达40%;异甘草素联合替莫唑胺组随着浓度增加抑制作用越强,且160μmol/L+200μmol/L时抑制率达72%;随着异甘草素浓度增加G0/G1期细胞比例增加,细胞周期阻滞于G0/G1期;随着异甘草素浓度增加干细胞分化越多,且分化细胞的死亡越多。结论异甘草素能诱导SHG44人脑胶质瘤干细胞向星形胶质细胞和神经元细胞分化,且能抑制增殖,同时增强替莫唑胺化疗敏感性。     

葡萄糖载体-1在高血压性脑出血患者脑组织星形胶质细胞中的表达

目的　探讨葡萄糖载体 1(Glut 1,相对分子质量为 45 0 0 0 )在高血压性脑出血 (HIH)患者脑组织星形胶质细胞中的表达。方法　应用免疫组化方法 (Glut 1、GFAP抗体 )对 7例HIH患者和 6例非神经系统疾病死亡患者 (对照组 )的脑组织标本进行标记 ,分析脑出血后 2 4h内、72h后的星形胶质细胞中 45 0 0 0Glut 1表达的变化 ,同时采用多媒体彩色病理图文系统 (MPIAS 5 0 0 )计算星形胶质细胞中的平均灰度 (AGD)和平均光密度。结果　对照组 45 0 0 0Glut 1在星形胶质细胞中因表达较少 ,未达检测水平。 2 4h组HIH病灶周围反应性星形细胞增多、胞体增殖、肿胀 ,GFAP标记阳性 ;Glut 1在反应性星形细胞上同样呈明显阳性反应。 72h组标本显示GFAP和Glut 1强阳性反应 ,较 2 4h组表达明显增强 ,其AGD和平均吸光度均值分别为 2 0 3± 16和 0 .0 9± 0 .0 4。结论　 45 0 0 0Glut 1在HIH反应性星形胶质细胞中的表达增加 ,是一种充分保障脑组织葡萄糖能量代谢的防御机制 ;病灶周围星形胶质细胞反应性增生为血 脑屏障的破坏提供了一种代偿机制。     

血红素对脑神经元、星形胶质细胞、毛细血管内皮细胞的不同损伤作用

目的 研究不同剂量高铁血红素对脑内神经元、星形胶质细胞、脑毛细血管内皮细胞(BCEC)的损伤作用. 方法 (1)在原代培养大鼠脑皮质神经元、星形胶质细胞、BCEC上添加不同剂量(0、5、25、50 mmol/L)的高铁血红素孵育2h,去血红素后继续培养24或96 h,阿拉玛蓝染色检查细胞存活率,常规生化反应法检测乳酸脱氢酶(LCD)释放率,相差光学显微镜观察细胞形态.(2)在原代培养细胞上添加不同剂量血红素孵育2h,去血红素后继续培养4h,以浓甲酸裂解细胞,分光光度计下测定细胞内血红素含量.(3)在原代培养细胞上加血红素分别孵育30、60、120 min,去血红素后继续培养4h,以中性福尔马林液固定细胞,普鲁士蓝染色检查细胞内三价铁离子(Fe3+)染色情况. 结果 (1)神经元经5 mmol/L的血红素处理后24 h,存活率下降40.2％,LCD释放率增加22.2％,细胞形态出现严重损伤病变.随着时间延长和血红素剂量加大,细胞死亡率和LCD释放率均增加,细胞病变加重.(2)中、低剂量血红素(5 mmol/L、25 mmol/L)不引起星形胶质存活率、LCD释放率及细胞形态改变,高剂量血红素(50 mmol/L)在24 h后导致星形胶质细胞存活率下降52.4％,LCD释放率增加31.8％,并出现细胞病变;但96 h后损伤细胞得到修复,细胞重新形成致密单层,细胞存活率和LCD释放率均达正常水平.(3)无论低剂量或高剂量血红素均未引起BCEC存活率下降、LCD释放率升高或细胞形态学改变.(4)经不同剂量血红素处理2h后,神经元内血红素含量均明显升高,星形胶质细胞内血红素含量只有在大剂量血红素处理后才升高,BCEC内血红素含量未见升高.(5)神经元接触血红素30 min后细胞内即出现大量Fe3+染色阳性颗粒,随着接触时间延长和剂量加大,Fe3+染色阳性细胞数增多;星形胶质细胞Fe3+染色阳性细胞数明显少于神经元,BCEC几乎不出现Fe3+染色阳性细胞. 结论 (1)血红素对神经元具有严重的直接损伤作用,对星形胶质细胞有可逆的损伤作用,对BCEC无直接损伤作用.(2)血红素能快速进入神经元并在神经元内积累,但较少在星形胶质细胞脑积累,难以在BCEC内积累.     

125IUdR靶点内照射与C6胶质瘤细胞的增殖抑制和细胞周期变化

目的　研究1 2 5IUdRDNA靶点放疗对大鼠C6 胶质瘤细胞增殖和细胞周期的影响。方法　体外采用C6 细胞单层指数生长模型 ,体内运用脑胶质瘤C6 大鼠 (肿瘤增殖高峰期局部缓慢三次注射药物 ,8 1× 10 3kBq·次- 1 ·天- 1 ) 3 0只 ,结合MTT法、平板克隆形成试验和流式细胞仪 (FCM)检测肿瘤细胞的增殖情况和细胞周期分布 ,研究1 2 5IUdR治疗脑胶质瘤的作用机理。结果　1 2 5IUdR可显著抑制C6 细胞增殖 ,具有时间和浓度依赖性。细胞存活曲线呈无肩区曲线 (直线 ) ,C37=9 0 6kBq/mL ;MTT法中 15 0kBq/mL1 2 5IUdR作用 5d后抑制率达 93 0 6% ;而Na1 2 5I和1 2 7IUdR对C6 细胞生长无明显抑制作用 ;1 2 5IUdR治疗胶质瘤C6 大鼠 5d后 ,肿瘤重量低于对照组 (P <0 0 1)。1 2 5IUdR可使C6 细胞停滞于G0 /G1 期 ,G0 /G1 期比例上升 ,S期比例降低。体外经 2 5 0kBq/mL1 2 5IUdR作用 7d,G0 /G1 期和S期分别占 76 2 3 %和 12 84% ,与空白组比较P <0 0 1:体内C6 胶质瘤经1 2 5IUdR治疗后 ,G0 /G1 期和S期分别为 85 19%和 10 5 1% ,与对照组及空白组比较 ,均P <0 0 5。结论　1 2 5IUdR可显著抑制脑胶质瘤细胞的增殖 ,导致细胞周期调控紊乱 ,G0 /G1 期阻滞。1 2 5IUdR在治疗脑胶质瘤方面具有潜力。     

低渗状态下星形胶质细胞AQP4mRNA的表达和Ca2+浓度的关系

目的探讨低渗培养液对星形胶质细胞AQP4mRNA的表达变化和Ca2 浓度的影响及其之间的关系。方法取生后2d的Wistar大鼠大脑皮层进行星形胶质细胞纯培养,分别予不同程度的低渗培养液作用于细胞,建立细胞对低渗液反应的实验模型。应用台盼蓝测定细胞存活率,采用原位杂交检测AQP4mRNA的表达,Fura-2/AM荧光法测定细胞内Ca2 浓度。结果体外培养的星形胶质细胞在低渗培养液分别作用3h、6h、12h、24h后,低渗组的细胞存活率较对照组明显减少,各时间点AQP4mRNA表达水平与细胞内Ca2 含量均明显高于对照组,与对照组相比差异有显著意义(P<0.05),而且与作用时间以及低渗液的严重程度密切相关;AQP4mRNA的表达强度与Ca2 浓度的变化呈明显正相关。结论低渗液可引起星形胶质细胞AQP4mRNA的表达上调,导致细胞内Ca2 超载,AQP4和Ca2 可能共同参与脑水肿的形成,提示AQP4可能是脑水肿的重要致病因素之一。     

深入开展胶质瘤综合治疗及其基础研究

胶质瘤亦称神经胶质细胞瘤 ,包括多种发生于神经外胚层细胞的肿瘤 ,国内报告约占颅内肿瘤的3 5 2 6%～ 60 96% (平均 44 69% ) [1] 。其分类尚缺乏统一意见 ,近来文献上常依其恶性程度分为低分级和高分级二种。低分级胶质瘤约占颅内肿瘤的1 0 %～ 1 5 % ,包括一般病理学分类的Ⅰ～Ⅱ级星形细胞瘤、毛细胞型及肥胖细胞型星形细胞瘤、纤维型及原浆型星形细胞瘤、轻度间变性星形细胞瘤、少支胶质瘤及神经节胶质瘤等 ;生存时间约为 5～1 0年 ,5 %～5 0 %可达 1 0年以上 ,3 0 %病例有恶性升级的经历[2 ] 。高分级胶质瘤亦称恶性胶质瘤 ,包括一…     

星形胶质细胞和神经元凋亡的细胞周期时相分布特征

目的 通过测定星形胶质细胞和神经元各自细胞凋亡的细胞周期特异性分布规律,以进一步探讨两种细胞不同的凋亡发生机制. 方法 建立大脑中动脉阻塞再灌注模型并取损伤后3 d的脑组织进行分析,缺血再灌注3 d后取脑,采用BrdU方法标记S期的细胞;再利用流式细胞分选技术特异性的将星形胶质细胞和神经元分选出来,采用BrdU标记并结合TUNEL方法,分析星形胶质细胞和神经元凋亡的细胞周期定位. 结果 与正常组比较,缺血再灌注组中缺血侧大脑皮层可见BrdU标记阳性细胞和TUNEL标记阳性细胞均明显增多,并可见TUNEL阳性和BrdU阳性双重标记的细胞.星形胶质细胞凋亡可以发生在细胞周期的各个时相,大多发生在G0/G1期,比神经元在G0/G1期的细胞凋亡率显著增高(P＜0.01);神经元进入S期的细胞凋亡率显著高于星形胶质细胞(P＜0.01). 结论 星形胶质细胞和神经元的细胞凋亡是多点启动的,脑缺血后两种细胞的凋亡具有不一致的细胞周期时相性分布特征.     

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.     

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.     

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.