Ⅰ型胶原修饰聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞的黏附和成骨分化

背景：组织工程骨成骨功能终末细胞需要骨髓间充质干细胞在体外加以诱导或在体内以基因转染等技术加以诱导。 目的：研究Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球支架上骨髓间充质干细胞黏附和成骨分化的能力。 方法：制备聚乳酸聚乙醇酸微球支架,分离纯化雌性SD大鼠骨髓间充质干细胞。将培养至第3代骨髓间充质干细胞与未经处理的聚乳酸聚乙醇酸微球及Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球共同培养14 d,观察细胞在不同支架表面的黏附生长。 结果：扫描电镜及FDA-PI染色发现,骨髓间充质干细胞可在聚乳酸聚乙醇酸微球支架上生长,而与未修饰的聚乳酸聚乙醇酸微球相比骨髓间充质干细胞更容易在Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球上黏附增殖。Ⅰ型胶原修饰的聚乳酸聚乙醇酸微球有利于骨髓间充质干细胞的黏附、增殖,并且有一定诱导干细胞成骨分化的能力。     

聚羟基丁酸与羟基辛酸骨组织工程支架的表面修饰**◆

目的：研究多聚赖氨酸表面修饰的聚羟基丁酸与羟基辛酸骨组织工程支架对细胞黏附、增殖及分化的影响。 方法：冷冻干燥/颗粒沥滤法制备聚羟基丁酸与羟基辛酸多孔支架,将其置于0.1,1.0,10 g/L的多聚赖氨酸溶液中,负压排气吸附进行表面修饰。灭菌后的支架置于48孔板,接种兔骨髓间充质干细胞。分别于1,4,7,10,14 d取样。 结果：3个多聚赖氨酸修饰组的细胞黏附率均高于支架-细胞组(P < 0.01),且细胞黏附率随多聚赖氨酸修饰质量浓度的增大而显著提高。1,4 d时10 g/L多聚赖氨酸修饰组的细胞增殖活性和碱性磷酸酶活性均高于其他两组,但至10,14 d时却低于其他两组。 结论：多聚赖氨酸修饰的聚羟基丁酸与羟基辛酸多孔支架有利于提高骨髓间充质干细胞的黏附率,但1.0 g/L的多聚赖氨酸修饰更有利于细胞的增殖与促成骨分化。 关键词：聚羟基丁酸与羟基辛酸;骨组织工程;支架;表面修饰     

3D自组装肽纳米纤维支架对胰岛细胞分泌功能的影响

背景：3D自组装肽纳米纤维支架能很好模拟体内微环境,给予细胞必要的结构模式,促进细胞外基质的正确组成及细胞的生长,改善细胞功能。 目的：体外观察3D自组装肽纳米纤维水凝胶支架对胰岛细胞分泌功能的影响。 方法：将3D自组装肽纳米纤维水凝胶支架与成年大鼠胰岛细胞共培养,AO-PI荧光染色法检测胰岛细胞的活性及生存率;放射免疫法测定胰岛细胞的分泌功能;扫描电镜观察胰岛细胞包裹在3D纳米支架中成三维立体的生长状态。 结果与结论：在3D纳米支架培养环境中胰岛细胞纯度≥80%;3D纳米支架组胰岛生存率及胰岛细胞分泌功能明显高于无支架组(2D培养组)(P < 0.05);扫描电镜显示自组装肽纳米纤维支架形成了具有几何形状的纳米级薄层,将胰岛细胞包裹在3D纳米支架中,胰岛细胞成三维立体生长。表明3D自组装肽纳米纤维支架可为胰岛细胞体外生存提供3D培养环境,改善胰岛细胞的活性、分泌功能及形态,延长胰岛细胞体外生存期。     

新型三维编织型生物支架的研制及体外生物相容性*☆

背景：脊髓损伤后,由于有胶质瘢痕的阻隔,使再生的轴突难以穿越损伤区域,从而影响脊髓功能的恢复。随着组织工程技术的发展,研究人员尝试利用在三维支架的空间诱导作用下,让再生的轴突和支架内部携带的细胞能够三维有序的生长,穿越瘢痕屏障,连接脊髓损伤断端。 目的：采用编织工艺研制新型以聚乙交酯-丙交酯为原料的三维支架,检测新型支架与许旺细胞的生物相容性。 设计、时间及地点：体外对比观察实验,于2007-06/2008-03在长海医院中心实验室完成。 材料：选择聚乳酸︰聚羟基乙酸为9︰1的聚合材料聚乙交酯-丙交酯,通过熔融纺丝、拉伸、编织等步骤制作聚乙交酯-丙交酯三维支架。取新生3 d SD乳鼠的坐骨神经,分离、纯化许旺细胞。 方法：实验分3组：三维支架组将许旺细胞接种在新型三维支架内培养;明胶海绵组将许旺细胞接种在胶原海绵上培养;细胞培养皿组直接接种在预涂左旋多聚赖氨酸的24孔培养板上培养。 主要观察指标：扫描电镜观察内部微管道的排列规律,测量其孔径大小、孔隙率等指标。通过倒置相差显微镜和扫描电镜观察许旺细胞在支架上生长情况,包括许旺细胞在支架上的黏附、增殖和凋亡情况等。 结果：支架外径为3 mm,微管道内径为100 μm,呈均匀平行排列,支架的孔隙率为68%。三维支架组与细胞培养皿组中的许旺细胞黏附、增殖差异无显著性意义,与明胶海绵组差异有显著性意义。三维支架组与明胶海绵组中细胞凋亡差异无显著性意义,它们均低于细胞培养皿组,差异有显著性意义。 结论：新型三维编织型支架具有良好的生物相容性。 关键词：支架;许旺细胞;组织工程;生物相容性     

三维支架材料与脂肪干细胞的生物相容性

背景：构建组织工程化气管需要适合的三维支架。 目的：观察脂肪干细胞与聚乳酸-乙醇酸共聚物及聚三亚甲基碳酸酯共聚物支架的生物相容性。 方法：采用组织块法原代分离培养SD大鼠脂肪干细胞,行流式细胞术及多向分化能力鉴定。将脂肪干细胞分别种植于聚乳酸-乙醇酸共聚物和聚乳酸-乙醇酸-三亚甲基碳酸酯共聚物支架中,扫描电镜观察细胞与支架的生物相容性。 结果与结论：脂肪干细胞种植于两种支架材料后生长速度快,扫描电镜观察可见脂肪干细胞呈球型,并伸展形成伪足,贴附于支架材料,细胞间相互连接成团。说明聚乳酸-乙醇酸共聚物与聚三亚甲基碳酸酯共聚物支架均具有良好的生物相容性,无细胞毒性,其多孔的三维立体状结构适合脂肪干细胞黏附生长。     

多聚赖氨酸对脂肪来源干细胞三维立体条件下生物学特性的影响**

背景：多聚赖氨酸可促进软骨细胞、表皮细胞的黏附、生长及增殖。 目的：观察多聚赖氨酸对脂肪来源干细胞三维立体培养下生物学活性的影响。 方法：采用流式细胞仪检测昆明小鼠脂肪来源干细胞表面CD29、CD34、CD44、CD45的表达,将脂肪来源干细胞分别与经多聚赖氨酸表面修饰的珊瑚羟基磷灰石或空白珊瑚羟基磷灰石体外复合培养。 结果与结论：与空白珊瑚羟基磷灰石组比较,经多聚赖氨酸修饰的珊瑚羟基磷灰石上黏附的脂肪来源干细胞较空白珊瑚羟基磷灰石组多,并分泌较多细胞基质,复合培养2,4,8 d的A值较明显增高(P < 0.05);但经多聚赖氨酸修饰的珊瑚羟基磷灰石上黏附的脂肪来源干细胞碱性磷酸酶活性值升高不明显(P > 0.05)。说明多聚赖氨酸能促进脂肪来源干细胞在珊瑚羟基磷灰石表面的黏附、生长和增殖,不影响脂肪来源干细胞向成骨细胞转化。     

壳聚糖与大鼠嗅鞘细胞的生物相容性

背景：众多研究证实,嗅鞘细胞移植和生物导管在修复中枢神经系统损伤中发挥了显著的作用,课题组前期研究已证实了壳聚糖在大鼠体内神经系统具有良好的生物相容性。 目的：观察壳聚糖与大鼠嗅鞘细胞的生物相容性。 设计、时间及地点：体外细胞学对比观察,于2005-12/2006-05在武汉协和医院泌尿外科实验室完成。 材料：将壳聚糖粉溶于10 g/L的乙酸溶液中,配制成10 g/L的壳聚糖溶液;显微剥离成年大鼠嗅球表面层,按常规方法行原代细胞培养。 方法：实验分为3组,每组10孔。壳聚糖组将制备好的壳聚糖溶液0.1 mL加入到培养板中,50 ℃烘箱至成膜干燥,加入40 g/L氢氧化钠溶液中和乙酸,双蒸水漂洗,晾干即可。多聚赖氨酸组按常规方法赖氨酸包被培养板。未包被组不用任何材料包被。将原代培养的嗅鞘细胞分别接种至壳聚糖包被、多聚赖氨酸包被和未包被的培养板上进行培养。 主要观察指标：于培养第3,5天显微镜下观察细胞形态学变化,MTT比色实验检测细胞存活和增殖状况。 结果：嗅鞘细胞可在壳聚糖膜上贴壁生长,细胞形态及数量与未包被组相比差异无显著性意义,但与多聚赖氨酸组相比细胞数量偏低。 结论：嗅鞘细胞与壳聚糖有良好的生物相容性。     

脱细胞化肝脏生物衍生支架的制备及鉴定**

背景：肝细胞在体外迅速失去极性及合成代谢障碍成为肝脏组织工程研究需要克服的一个难题,在体外寻找一个有利于肝细胞生长与功能维持的细胞外基质微环境成为目前研究的焦点。 目的：制备肝脏去细胞化细胞外基质生物衍生支架,并对该生物衍生支架进行初步鉴定。 设计、时间及地点：观察性实验,于2008-02-15/05-01在广东省脑功能修复与再生研究所完成。 材料：10只雄性SD大鼠用于制备去细胞肝脏细胞外基质支架。10只雄性SD大鼠用于制备原代肝细胞。 方法：将SD大鼠肝脏切成10 mm×5 mm的组织片后,经过胰酶-乙二胺四乙酸作用24 h、去垢剂曲拉通×100 72 h后得到肝脏去细胞化生物衍生支架。每只大鼠获取2×108个肝细胞,将所得原代细胞与肝脏去细胞化生物衍生支架放入含DMEM-F12,体积分数为10%胎牛血清,胰岛素0.5 U/mL,地塞米松1×10-7 mmol/L,表皮生长因子10 μg/L的培养基中共培养,并与单纯原代细胞培养相比较。 主要观察指标：培养14 d时组织块行苏木精-伊红染色,Masson染色进行组织学分析。并行扫描电镜观察。对培养1,3,5,7,9,14 d上清液进行白蛋白及尿素水平检测。 结果：组织学检查未见明显细胞核残存,大量胶原纤维得到保留,扫描电镜示纤维成网状排列。支架与原代肝细胞共培养上清液白蛋白和尿素水平高于单纯原代肝细胞培养（P < 0.05）。 结论：利用去垢剂与胰酶-乙二胺四乙酸低渗溶液处理可以有效完整去除肝脏组织块的细胞成分,较完整地保留细胞外基质;该生物衍生支架有利于肝细胞的生长及功能维持。     

多聚赖氨酸和明胶对神经干细胞增殖和分化的影响

摘要 背景：目前大鼠神经干细胞体外诱导分化的研究报道诸多,但其分化过程很难控制,很多实验的操作方法复杂,分化比率也很低。 目的：探索大鼠胚胎前脑神经干细胞体外原代及传代培养方法,并观察其分化规律。 方法：胎鼠在无菌条件下分离出前脑,制备单细胞悬液,以1×1011L-1接种于含N2的DMEM/F12培养基中培养,传代培养过程中加入BrdU,标记神经干细胞球。诱导分化实验分为多聚赖氨酸铺板组、明胶铺板组和无铺板组。采用体积分数20%胎牛血清刺激其分化。免疫细胞化学检测nestin、BrdU及在血清诱导条件下神经干细胞向神经细胞分化的能力。 结果与结论：细胞呈神经干细胞样生长,具有连续增殖能力,可以传代培养。传代神经球中的细胞均呈nestin阳性和BrdU阳性。多聚赖氨酸铺板组和明胶铺板组贴壁后分化为神经细胞能力强于无铺板组(P < 0.01)。多聚赖氨酸铺板组略强于明胶铺板组(P > 0.05)。神经谱系标记物神经胶质纤维酸性蛋白和微管相关蛋白2的免疫细胞化学结果均阳性。结果表明,大鼠胚胎前脑富含神经干细胞,其分化观察,多聚赖氨酸和明胶在诱导神经干细胞分化中作为细胞贴壁支持物提高分化细胞数量的作用,且多分化为星形胶质细胞。 关键词：多聚赖氨酸;神经干细胞;明胶;增殖分化;体外培养 doi:10.3969/j.issn.1673-8225.2010.47.004     

施万细胞对骨髓基质干细胞向神经组织细胞分化诱导的作用

背景：骨髓基质干细胞具有向神经组织细胞分化的多潜能特性。以往实验以化学试剂作为诱导剂加入细胞培养液中,在体外成功地诱导出神经组织细胞。 目的：观察大鼠施万细胞和骨髓基质干细胞体外共培养后,骨髓基质干细胞能否被诱导向神经组织细胞分化。 设计、时间及地点：细胞学体外观察,于2006-09/2008-10在南通大学医学院组织学与胚胎学教研室及江苏省神经再生重点实验室完成。 材料：SPF级新生1~3 d龄SD大鼠用于制备施万细胞,SPF级成年雄性SD大鼠用于制备骨髓基质干细胞,动物均由南通大学实验动物中心提供。 方法：将传2代培养的骨髓基质干细胞和施万细胞分别以1×105和1×106的密度接种于transwell双层6孔细胞培养板的皿底和板底,两种细胞间隔以PET膜,其膜孔径为0.4 μm,于37 ℃、体积分数为5%的CO2培养箱中进行非接触性共培养14 d。另外,将施万细胞培养上清作为条件培养基,培养骨髓基质干细胞14 d。 主要观察指标：光镜下观察共培养后骨髓基质干细胞的形态变化;MTT检测共培养前后骨髓基质干细胞的活性;免疫荧光染色鉴定共培养后骨髓基质干细胞S-100蛋白的表达,流式细胞仪测定S-100蛋白阳性率;免疫荧光染色检测条件培养基培养后骨髓基质干细胞S-100,P75,GFAP的表达。 结果：共培养后的骨髓基质干细胞形态发生改变,原来宽大扁平的胞体开始收缩,细胞胞体呈梭形,部分细胞类似施万细胞呈线性排列。共培养前后及条件培养基培养后,骨髓基质干细胞的活力无明显差异(P > 0.05)。共培养14 d后,骨髓基质干细胞表达施万细胞表面标记S-100蛋白,阳性率达(22.54±2.36)%。条件培养基培养14 d后,骨髓基质干细胞表达施万细胞表面标记S-100蛋白,P75,GFAP。 结论：施万细胞分泌因子可以诱导部分骨髓基质干细胞向神经组织细胞分化,并表达施万细胞表面标记。     

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.