糖尿病大鼠表皮干细胞的分离培养及特性

背景：表皮干细胞作为皮肤组织特异性干细胞,在创面修复中发挥关键作用。但有关糖尿病皮肤来源的表皮干细胞体外分离培养及生物特性研究较少。 目的：探索糖尿病大鼠表皮干细胞体外分离培养的方法及其生物特性,为糖尿病难愈创面的防治及机制研究提供实验依据。 方法：SD大鼠随机分成糖尿病组和正常对照组。糖尿病组采用一次性腹腔注射链脲佐菌素制备糖尿病大鼠模型,正常对照组不作处理。分别取成模糖尿病和正常大鼠背部全层皮肤,采用酶消化联合Ⅳ型胶原黏附法分离培养大鼠表皮干细胞。倒置相差显微镜下观察细胞形态变化和细胞克隆形成,细胞计数绘制生长曲线,计算克隆形成率,免疫细胞化学染色和图像分析软件鉴定K19、β1-integrin阳性表达和测定阳性细胞的积分吸光度(IA)值。 结果与结论：糖尿病组大鼠表皮干细胞原代贴壁数量较少,其克隆形成率明显低于正常对照组(P < 0.01)。表皮干细胞的K19、β1-integrin均呈阳性表达,糖尿病组阳性细胞的IA值均低于正常对照组(P < 0.01)。结果提示,运用酶消化联合Ⅳ型胶原黏附法可以实现糖尿病大鼠表皮干细胞的体外分离培养;糖尿病大鼠表皮干细胞体外增殖能力较正常皮肤增殖能力弱,这可能是导致糖尿病创面难愈合的重要因素之一。     

骨髓间充质干细胞在糖尿病创面中向皮肤腺上皮的分化***

背景：骨髓间充质干细胞具有多向分化潜能,目前已证实其在急性创面中能够向皮肤组织细胞转化,但在糖尿病创面中的分化报道甚少。 目的：观察糖尿病创面皮肤微环境中的骨髓间充质干细胞分化为皮肤附属器细胞的可行性。 方法：全骨髓法分离纯化大鼠骨髓间充质干细胞,传至第三四代细胞行5-BrdU标记。采用一次性腹腔注射链脲佐菌素法建立糖尿病大鼠模型,2周后在模型鼠背部制作圆形创面,取密度为1×109 L-1 5-BrdU标记的骨髓间充质干细胞悬液1 mL注射于创面边缘,分别于细胞移植后2,3周切取创面中央再生组织制备切片,行BrdU和角蛋白免疫组织化学染色。 结果与结论：BrdU阳性细胞出现在表皮、真皮及皮下组织各层,部分阳性细胞位于皮脂腺及腺导管上皮中;连续切片中BrdU阳性细胞同时也表达角蛋白,以腺导管上皮多见。提示在糖尿病溃疡创面愈合过程中,骨髓间充质干细胞具有向皮肤附属器细胞分化的潜能。     

康肤霜对大鼠放射性皮肤损伤创面愈合的影响

背景：放疗中引起的放射性皮肤损伤,常使用重组人表皮生长因子和聚维酮碘治疗,但两者均有一定缺陷。而康肤霜能促进细胞分裂增殖,具有一定的抗菌消炎作用,可能对放射性皮肤损伤有很好的疗效。 目的：观察康肤霜对大鼠放射性皮肤损伤创面愈合的影响。 方法：高能X射线照射Wistar大鼠臀部皮肤建立深Ⅱ度皮肤烧伤创面模型。照射后12 d创面出现后,将损伤动物随机分为康肤霜组,重组人表皮生长因子组和聚维酮碘组。各组每日将药物均匀涂抹在创面,直至创面取材或创面愈合。观察创面愈合率及愈合时间。各组动物分别于创面治疗后7,14,21 d取创面组织,观察病理组织学变化、创面组织增殖细胞核抗原的表达,以标记指数法测定增殖细胞核抗原阳性细胞数,评估组织创面的修复情况。 结果与结论：康肤霜组与重组人表皮生长因子组创面愈合时间、愈合率均优于聚维酮碘组(P < 0.01),但两组间无显著差异 (P > 0.05)且两组创面组织标本中增殖细胞核抗原表达量也明显高于聚维酮碘组(P < 0.01),但其两组间比较差异无显著性意义(P > 0.05)。说明康肤霜能减轻创面早期的炎症反应,促进创面的再上皮化和表皮各层的分化,加速大鼠放射性皮肤损伤创面的愈合。     

大鼠骨髓间充质干细胞在创面愈合中的作用

背景：骨髓可能是体内所谓间质组织的干细胞库,一旦组织受损,信号可通过未知方式到达骨髓,促进体内的间充质干细胞向创伤部位迁移。 目的：探讨骨髓间充质干细胞在创面愈合中的作用。 设计、时间及地点：细胞学体内观察,于2006-07/2007-07在东南大学完成。 材料：健康6~8周龄SD大鼠34只,由东南大学医学院实验动物中心提供。 方法：取4只大鼠,采用全骨髓法体外分离培养骨髓间充质干细胞,取传至第5代细胞,移植前48 h行BrdU标记。剩余30只大鼠麻醉后制作全层皮肤缺损模型,以对侧对称部位皮肤作为自身正常对照。造模后将标记的2×107个骨髓间充质干细胞经尾静脉注入体内。 主要观察指标：于创伤后不同时间点采用大体观察、免疫荧光化学染色等手段,动态观察骨髓间充质干细胞参与创面修复情况。 结果：大鼠造模后伤口有少量炎性渗出,细胞移植后7 d创面均形成较硬的痂皮,14 d创缘有新生表皮生成,21~28 d大部分创面愈合,未出现炎症、化脓现象。细胞移植后第7,14,21,28天组织切片均可见BrdU染色阳性细胞,胞核呈绿色荧光,在创面边缘和创伤局部聚集。细胞移植后第14天组织切片可见BrdU染色阳性的细胞(胞核为绿色荧光)胞浆中有FⅧ表达,呈红色荧光,提示可能有部分骨髓间充质干细胞分化为血管内皮细胞参与创面愈合。对侧正常皮肤未见明显的骨髓间充质干细胞聚集和增殖分化。 结论：创伤可能是一种刺激因素,招募自身或外源的骨髓间充质干细胞参与创面愈合。     

原位定型微囊化载体制剂在糖尿病大鼠皮肤溃疡中的作用

背景：原位定型微囊化载体制剂成分之一胰岛素可以促进溃疡愈合。 目的：观察原位定型微囊化载体制剂在糖尿病大鼠皮肤溃疡中的疗效。 方法：腹腔内注射链脲佐菌素建立糖尿病大鼠模型,应用外科方法建立全层皮肤缺损模型。根据皮肤溃疡处干预方式将实验动物分为4组。①空白对照组用生理盐水处理创面。②一般制剂组应用甲硝唑+山莨菪硷1+普通短效胰岛素处理创面。③单纯微囊组创面外敷不含有效药物成分的微囊化载体膜。④微囊化有效制剂组溃疡处外涂微囊化载体制剂膜,内含药物成分与一般制剂组相同。定时测量溃疡面积,记录溃疡愈合时间,取创面全层组织进行组织学观察,测定表皮生长因子受体、纤维连接蛋白阳性细胞数量。 结果与结论：微囊化有效制剂组大鼠溃疡愈合时间短于其他3组(P < 0.05或P < 0.01),微囊化有效制剂组表皮生长因子受体和纤维连接蛋白阳性细胞数目高于其他各组(P < 0.05或P < 0.01)。结果表明,原位定型微囊化载体制剂能够缩短愈合时间和促进糖尿病大鼠皮肤溃疡愈合。     

组织工程皮肤移植过程中白细胞介素10和肿瘤坏死因子α的表达

背景：白细胞介素10和肿瘤坏死因子α在异体异种皮肤移植局部免疫与排斥反应中发挥了重要作用。但在组织工程人工皮肤移植过程中局部皮肤组织内白细胞介素10和肿瘤坏死因子α的表达情况目前尚不清楚。 目的：采用表皮干细胞联合脱细胞真皮构建人工皮肤并移植修复兔全层皮肤缺损创面,观察创面修复效果和局部皮肤组织白介素10与肿瘤坏死因子α的表达变化。 方法：将体外培养的人表皮干细胞或角质细胞接种到脱细胞真皮支架中,构建组织工程人工皮肤;取新西兰白兔常规制作背部全层皮肤缺损创面随机分为4组,表皮干细胞组、角质细胞组用含表皮干细胞或角质细胞的组织工程皮肤移植于皮肤缺损创面;脱细胞真皮组移植单纯脱细胞真皮;对照组创面空置。观察创面修复情况,局部炎症反应,创面愈合时间。各组分别于术后7d在部分创面取材观察组织形态和白细胞介素10与肿瘤坏死因子α表达。 结果与结论：含表皮干细胞的人工皮肤移植后创面愈合良好,局部炎症反应轻微,无出血、积脓、坏死,创面愈合时间较角质细胞组明显缩短。白细胞介素10在各组均有表达,其中表皮干细胞组表达最强,角质细胞组次之,脱细胞真皮组和对照组最弱。肿瘤坏死因子α在各组也均有表达,其中角质细胞组表达最强,表皮干细胞组次之,脱细胞真皮组和对照组较弱。说明以表皮干细胞作为种子细胞联合脱细胞真皮构建人工皮肤可用有效促进皮肤缺损创面的修复治疗,创面修复过程中局部皮肤组织内白细胞介素10和肿瘤坏死因子的表达变化可能是其取得较好效果的主要机制之一。     

老年大鼠脑出血后海马齿状回神经干细胞的增殖与分化

目的 观察老年大鼠脑出血后海马齿状回神经干细胞(NSCs)的增殖与分化,探讨脑出血后NSCs的变化规律.方法 制作老年大鼠脑出血模型,5-溴脱氧尿核苷(BrdU)腹腔注射标记增殖细胞,用免疫组化法检测大鼠海马齿状回BrdU、神经元核抗原(NeuN)、胶质纤维酸性蛋白(GFAP)阳性细胞数的变化.结果 正常组和假手术组老年大鼠海马齿状回均有少量BrdU阳性细胞,脑出血后大鼠各时间段的BrdU阳性细胞数目均较正常组和假手术组明显增加,7d组达到峰值后逐渐下降,28d组仍高于正常组和假手术组.正常老年大鼠海马齿状回可见少量BrdU/NeuN和BrdU/GFAP双标阳性细胞,脑出血后双标阳性细胞数较正常组明显增加.结论 脑出血后老年大鼠海马齿状回NSCs增殖明显,且可以向神经元和神经胶质细胞分化.     

BrdU标记大鼠骨髓间充质干细胞增殖与成骨能力的变化

背景：BrdU标记是一种标记率高、标记简便的标记物,但其毒性报道不一。 目的：观察BrdU标记对SD大鼠骨髓间充质干细胞增殖与成骨能力的影响。 方法：直接贴壁法分离培养大鼠骨髓间充质干细胞,0.2%Brdu标记后检测其增殖能力、克隆形成能力;经成骨诱导液诱导培养3周后,利用茜素红染色,荧光免疫组织化学和RT-PCR观测标记前后骨髓间充质干细胞成骨能力的变化情况。 结果与结论：Brdu标记后骨髓间充质干细胞克隆形成能力明显减弱,在克隆个数和面积上均小于正常对照组(P < 0.05);在增殖能力方面,BrdU标记后第4天开始进入对数增长期时增殖较慢,高峰较低(P < 0.05);在成骨能力方面,经成骨诱导后BrdU标记组与正常对照组的骨髓间充质干细胞均表达骨钙素、Ⅰ型胶原,并且都有明显的钙结节形成,RT-PCR检测显示标记前后骨髓间充质干细胞在骨钙素基因的表达方面差异无显著性意义(P > 0.05)。提示BrdU标记抑制骨髓间充质干细胞的克隆增殖形成能力,但不会降低其成骨分化能力,可以广泛应用于骨髓间充质干细胞作为种子细胞干细胞研究的示踪剂。     

表皮干细胞向皮肤附件诱导分化的研究近况

摘要：皮肤组织工程技术为烧伤创面的修复提供了新的方法,但现有各类组织工程皮肤也面临着共同的难题,突出表现在：没有完整的皮肤功能,尤其是缺乏毛囊、皮脂腺和汗腺等,难以达到完全意义上的“功能愈合”。表皮干细胞作为皮肤组织的特异性干细胞, 与创面修复紧密相关,是维持皮肤新陈代谢的主要功能细胞和皮肤及其附属器发生、修复、改建的基础。表皮干细胞具有无限增殖潜能及多向分化潜能,通过整合素-丝裂原激活蛋白激酶通路、Wnt/β-连环素-Lef/ Tcf信号通路、神经肽等途径诱导分化形成毛囊、皮脂腺、汗腺及表皮等组织。由于表皮干细胞向皮肤附件诱导分化研究尚存在许多问题,目前大部分是关于表皮干细胞向皮肤附件诱导分化的动物实验研究,而其广泛的临床应用研究有待进一步发展。     

胰岛素样生长因子1在脑梗死大鼠神经干细胞增殖、迁移和分化中的作用*

背景：胰岛素样生长因子1是一种多肽类激素,已证明其对前体细胞增殖有促进作用。 目的：探讨静脉注射胰岛素样生长因子1对大鼠脑缺血后神经干细胞增殖、迁移和分化的影响。 方法：成年雄性SD大鼠80只,随机分为对照组和实验组,40只/组。两组大鼠均采用改良线栓法制备局灶性脑缺血模型,实验组大鼠通过尾静脉注射胰岛素样生长因子1,按100 μg/kg计算,连续注射6 d;对照组给予等剂量的生理盐水。分别于干预后7,14,21,28 d断头去脑,各组分别在处死前1 d腹腔注射BrdU。采用免疫组织化学及其双重染色法检测BrdU阳性细胞、PSA-NCAM阳性细胞、BrdU+PSA-NCAM双阳性细胞、BrdU+MAP2双阳性细胞的表达。 结果与结论：BrdU阳性细胞、PSA-NCAM阳性细胞数均在缺血后7 d最多;BrdU+PSA-NCAM双标阳性细胞在缺血后双侧室管膜下区和海马齿状回区均可以检测到,于7 d计数最多,之后逐渐减少;BrdU+MAP2双阳性细胞却从14 d开始逐渐增多,随BrdU+PSA-NCAM双阳性表达的逐渐降低,BrdU+MAP2双阳性表达逐渐增高,呈现此消彼涨的变化。提示静脉途经给予胰岛素样生长因子1能诱导大鼠缺血性脑损伤后神经干细胞的增殖、分化和迁移。     

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.     

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.