人脐血间充质干细胞静脉移植治疗大鼠局灶性脑缺血的实验研究

目的 探讨来源于人脐血的间充质干细胞经静脉移植治疗大鼠局灶性脑缺血的可行性及其机制.方法 将人脐血间充质干细胞在体外纯化、扩增并经BrdU标记后,经尾静脉移植到局灶性脑缺血大鼠体内,通过神经缺损评分观察移植后大鼠神经行为学改善情况,通过组织学方法观察移植到脑内的人脐血间充质干细胞表达脑源性神经营养因子和缺血灶周围微血管密度变化的情况.结果 人脐血间充质干细胞移植组大鼠的神经缺损评分显著低于对照组(P＜0.05);移植到脑内的人脐血间充质干细胞主要选择性分布于缺血灶周围区域并表达脑源性神经营养因子,移植组大鼠梗死灶周围的微血管密度显著高于对照组(P＜0.01).结论 经静脉注射移植人脐血间充质干细胞能明显促进局灶性脑缺血大鼠的神经行为功能恢复,促进缺血灶周边区微血管增生可能是人脐血间充质干细胞移植治疗局灶性脑缺血的机制之一.     

骨髓间充质干细胞对局灶脑缺血再灌注损伤的超早期干预

摘要：目的　探讨骨髓间充质干细胞(BMSCs) 对大鼠脑缺血再灌注损伤保护作用及机制。方法　雄性SD大鼠72只,以线栓法制成缺血再灌注模型,随机分为2组：溶剂对照组;BMSCs移植组。在缺血再灌注后1天、3天、6天分别行神经功能检测、TTC染色、免疫组化法检测Survivin、caspase-3表达,TUNEL法检测凋亡细胞表达。结果　与溶剂对照组比较,在梗死脑组织中移植骨髓间充质干细胞BMSCs后,可使大鼠神经功能有所恢复,在大鼠大脑中动脉局灶脑缺血90分钟再灌注3天及6天神经功能评分比较高,有统计学意义;TTC染色脑梗死体积百分比在缺血再灌注第3天、第6天较溶剂对照组分别减少2.13%和2.10%,有统计学意义。单纯BMSCs移植组比较对照组在缺血再灌注后1天、3天、6天缺血侧皮层Survivin表达增高、caspase-3表达降低,凋亡细胞减少,均有统计学意义。结论　脑缺血部位脑实质单纯 BMSCs 移植能够改善缺血后神经功能,减少脑缺血后梗死体积,可能通过增加脑缺血再灌注损伤部位Survivin蛋白的表达,降低凋亡相关蛋白Caspase-3表达,减少凋亡细胞数量发挥作用     

基质细胞衍生因子1及其受体CXCR4对人骨髓间充质干细胞向

背景：近年研究发现移植的骨髓间充质干细胞能向颅内创伤、脑卒中、炎症和变性疾病等病灶部位迁移,进而发挥治疗作用,但对于其向病灶定向迁移的具体机制还不十分清楚。 目的：探讨基质细胞衍生因子1及其受体 CXCR4在移植的骨髓间充质干细胞趋向缺血脑组织迁移中的作用。 设计、时间及地点：细胞学体内实验,于2008-02/2009-02在解放军第三军医大学新桥医院中心实验室进行。 材料：骨髓标本取自解放军第三军医大学附属新桥医院血液科收治的15~40岁正常或原发病未累及骨髓患者,三四月龄健康雄性SD大鼠72只由解放军第三军医大学野战外科研究所实验动物中心提供。 方法：密度梯度离心贴壁筛选法分离纯化、体外培养人骨髓间充质干细胞。54只大鼠参照Nagasawa线栓法制备局灶性脑缺血再灌注模型,剩余18只作为假手术组,仅插入线栓10 mm。模型组及假手术组大鼠各取9只,分别于造模后第2,4,8天,采用Real-time PCR和免疫组织化学法定量分析缺血脑组织基质细胞衍生因子1表达变化。剩余36只脑缺血再灌注模型鼠随机分为细胞移植组、溶液对照组,18只/组,于再灌注后24 h分别从尾静脉缓慢注入1 mL人骨髓间充质干细胞悬液(含2×109 L-1个细胞)或1 mL PBS。 主要观察指标：人骨髓间充质干细胞CXCR4 mRNA和蛋白的表达,缺血再灌注后脑组织基质细胞衍生因子1 mRNA和蛋白表达变化,免疫组织化学检测人骨髓间充质干细胞向缺血脑组织的迁移和分布。 结果：RT-PCR结果发现人骨髓间充质干细胞表达CXCR4 mRNA,免疫细胞化学染色发现CXCR4主要表达于人骨髓间充质干细胞的胞膜和胞浆。脑缺血再灌注损伤后2,4,8 d,趋化因子基质细胞衍生因子1 mRNA水平呈上升趋势,与假手术组比较差异有显著性意义(P < 0.05)。经静脉移植的人骨髓间充质干细胞定向迁移到脑损伤区域,并大量分布于基质细胞衍生因子1高表达的缺血半暗区,损伤侧大脑半球人骨髓间充质干细胞数量显著高于对侧半球(P < 0.01)。 结论：基质细胞衍生因子1及其受体CXCR4参与并促进人骨髓间充质干细胞向脑缺血再灌注损伤区的迁移。     

亚低温与脑缺血大鼠骨髓间充质干细胞的迁移

背景：关于亚低温运用到神经损伤修复领域的研究已有一些报道,但亚低温对神经干细胞在脑内移植迁移的影响还不太清楚。 目的：观察亚低温对移植入脑缺血大鼠侧脑室的骨髓间质干细胞迁移的影响。 方法：采用Longa法永久性闭塞SD大鼠大脑中动脉制作局灶性脑缺血损伤模型,亚低温组于移植前应用亚低温处理大鼠急性脑缺血损伤,对照组于移植前应用常温处理大鼠急性脑缺血损伤;造模术后24 h,在脑立体定向下,经侧脑室注射移植用5-BrdU标记的骨髓间充质干细胞。经过5,14,21,28 d,7周后用免疫组织化学方法检测各组大鼠脑组织BrdU阳性细胞数。 结果与结论：移植第14天多数标记的骨髓基质细胞细胞已经迁移至梗死灶周围,移植后各时间点亚低温组梗死灶周边皮质的BrdU阳性细胞数明显多于对照组(P < 0.05)。提示移植前宿主亚低温处理可以促进骨髓间充质细胞的定向迁移,对局灶性脑缺血有神经保护作用。     

梯度离心法制备骨髓间充质干细胞胞质体及其鉴定

目的 建立制备骨髓间充质干细胞胞质体的方法 ,以用于体细胞核移植研究. 方法 (1)培养骨髓间充质干细胞,用流式细胞仪检测骨髓间充质干细胞表面标志物CD44、CD90、CD71、CD11b;(2)用梯度离心法制备骨髓间充质干细胞胞质体,并用HE染色、Giemsa染色、荧光双标染色、透射电镜检查等方法 进行鉴定,用台盼蓝染色检测其活性. 结果 (1)骨髓间充质十细胞呈长梭形、漩涡状生长.骨髓问充质干细胞表面标志物CD44、CD90、CD71表达阳性,CD11b表达阴性;(2)HE染色、Giemsa染色、荧光双标染色和透射电镜检查显示骨髓间充质干细胞经梯度离心后在15%～18%Ficoll400梯度层可收集到大量胞质体,胞质体可快速贴壁,表达CD71,与完整骨髓间充质干细胞相似,体积与完整细胞相比差别不大.有活性的胞质体比例达99.5%. 结论 用梯度离心法可有效获得骨髓间充质干细胞胞质体.     

食蟹猴骨髓源性神经干细胞自体脑内移植的研究

目的探讨食蟹猴自体骨髓基质细胞诱导分化成神经干细胞后移植到脑内的生长情况.方法对6只食蟹猴进行骨髓基质干细胞体外培养、诱导分化成神经干细胞,经BrdU标记后进行自体脑移植.动物分为即时移植组和延迟移植组,采用立体定向多点注射的方法将神经干细胞悬液移植到猴皮层创伤灶.结果HE染色显示即时移植和延迟移植的创伤区细胞数量都明显多于假移植治疗对照;免疫组织化学染色显示两组动物在干细胞移植后1～6个月脑皮层创伤灶内均有BrdU阳性表达细胞,移植后半年的动物在移植区邻近的脑白质内也可观察到有BrdU阳性表达的细胞,而创伤对照动物、假移植治疗动物和正常脑组织中则未见BrdU阳性表达. 结论BMSCs体外培养得到的神经干细胞经过自体移植能在脑皮层内存活,并且能增殖、分化和迁移,可成为神经干细胞的替代细胞或来源细胞;干细胞移植到陈旧性的脑皮层损伤灶也具有成活、增殖和迁移能力.     

磁共振活体示踪经冠状动脉骨髓间充质干细胞移植：验证其与病理组织学结果的一致性*☆

背景：目前动物实验及临床研究证明经冠状动脉移植骨髓间充质干细胞可改善心肌梗死后的心脏功能,但骨髓间充质干细胞经冠状动脉移植后能否到达心肌梗死部位仍存在争议。 目的：磁共振活体示踪经冠状动脉注射的骨髓间充质干细胞能否到达心肌梗死部位。 方法：全骨髓法分离培养猪骨髓间充质干细胞,超顺磁性氧化铁标记后胰酶消化,调整细胞浓度为1010 L-1。10只猪均建立心肌梗死模型,造模后1周通过OTW球囊导管经冠状动脉将标记好的骨髓间充质干细胞悬液定向移植至梗死区。普鲁士蓝染色评价细胞标记效率,采用快速梯度回波序列完成长轴位四腔心和二腔心扫描,在以长轴位四腔心和二腔心为定位相,垂直于室间隔获得左心室短轴位图像。 结果与结论：超顺磁性氧化铁可安全有效标记骨髓间充质干细胞,经冠状动脉注射的骨髓间充质干细胞能到达心肌梗死区及交界区,磁共振能示踪到超顺磁性氧化铁标记的骨髓间充质干细胞,示踪结果与病理组织学检查一致,且磁共振示踪时间可长达5周。     

血脑屏障对间充质干细胞的通透性

移植骨髓间充质干细胞是中枢神经系统疾病治疗的一大突破,但脑组织结构的特殊性限制了移植方式,无论是脑组织原位移植还是脑室内注射干细胞都存在着极大的危险性和局限性,经外周血管输注间充质干细胞可通过血脑屏障并向病变组织定向迁移,本文从特异性粘附分子的表达、血脑屏障固有薄弱环节、血脑屏障通透性的改变及病变组织的趋化作用等方面阐述了间充质干细胞进入脑实质的机制,为干细胞移植方法学提供理论依据。     

骨髓间充质干细胞向脑胶质瘤趋向性的初步研究

背景骨髓间充质干细胞(MSCs)是存在于骨髓中的非造血类干细胞,具有自我更新及多向分化潜能.在大鼠脑外伤模型中的迁移能力已得到证实,而其对于脑胶质瘤的趋向性的研究尚处于初期.本实验通过将标记的MSCs移植到大鼠脑胶质瘤模型体内,观察它的迁移情况.方法采用全骨髓细胞培养法,利用MSCs的贴壁生长及可在体外长期培养的特性,获取纯化的MSCs.采用流式细胞术鉴定其表面抗原及细胞周期.在处于对数生长期的MSCs培养皿中加入BrdUrd(终浓度10μg/mL),培养24～48 h后进行移植.采用立体定向技术建立大鼠脑胶质瘤模型,3 d后移植标记好的MSCs在大脑半球组,BrdUrd标记的MSCs被注入大鼠脑胶质瘤模型肿瘤对侧大脑;在颈内动脉组,BrdUrd标记的MSCs被注入大鼠脑胶质瘤模型肿瘤同侧的颈内动脉.分别以BrdUrd标记的3T3细胞作为对照组.2周后,处死大鼠取脑组织制作病理切片,进行抗BrdUrd免疫组化及免疫荧光染色,观察MSCs的迁移情况.结果全骨髓培养法获得了纯化的MSCs.移植到脑组织及颈内动脉的BrdUrd标记的MSCs表现出了明显的向脑胶质瘤迁移的特性.在大脑半球组,MSCs主要集中在肿瘤与正常脑组织的交界部位,在瘤内只有少量分布.在颈内动脉组,MSCs主要分布于肿瘤内部,在肿瘤与正常脑组织的交界位置有少量分布.结论MSCs具有明显的向脑胶质瘤迁移的特性,同时亦可通过血脑屏障,有可能成为胶质瘤基因治疗的理想载体.     

骨髓间充质干细胞移植及生长相关蛋白43表达在脑修复中的作用

背景：研究证实骨髓间充质干细胞移植能够促进脑功能恢复,并对大鼠脑皮质及海马结构损伤具有修复作用,可能与细胞的自身代偿以及神经生长递质的参与有关,也可能是由于神经应激性损伤刺激靶组织细胞分泌各种神经因子的表达有关。 目的：从细胞生物学的角度,观察大鼠脑缺血损伤后骨髓间充质干细胞移植对神经再生及脑的修复作用。 方法：参考改良Nagasawa法建立大脑中动脉闭塞再灌注模型后,实施骨髓间充质干细胞移植,并分别进行跑台运动训练和水迷宫康复训练,进行神经功能评分及学习记忆评分。采用TUNEL法检测脑皮质区及海马区凋亡神经元的表达以及免疫组化技术检测生长相关蛋白43蛋白在两区的表达变化。 结果与结论：移植组16 h移植骨髓间充质干细胞在皮质区及海马CA1区表达明显增加;7 d细胞表达达高峰,分化细胞明显增加。移植后运动训练7,19,21 d移植组mNSS评分低于模型组(P均< 0.01);移植组大鼠水迷宫试验平台潜伏期的时间较模型组明显缩短(P < 0.05);移植组大鼠穿越平台次数较模型组增多(P < 0.05);缺血再灌注24 h凋亡细胞达高峰,3 d梗死体积测量为最大值;再灌注19 d生长相关蛋白43达高峰。提示大鼠脑缺血损伤介导了神经功能缺损,骨髓间充质干细胞移植促进了神经再生,生长相关蛋白43表达上调抑制神经元凋亡,进一步促进了脑梗死灶的修复。     

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.