首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
目的探讨p53基因和PTEN基因在脑胶质瘤细胞系U251发生发展过程中的作用机制。方法用不同MOI的p53腺病毒表达载体pAdCMV-p53及空载体pAdCMV-lacZ分别感染表达野生型PTEN基因和突变型PTEN基因的细胞系,RT-PCR及Westernblot方法检测转染效率;并通过MTT检测生长抑制率、流式细胞仪检测细胞周期及TUNEL检测分析细胞凋亡等指标观察p53基因及PTEN基因对U251细胞生长的影响。结果MOI为100时,p53基因可引起U251细胞G0G1期阻滞、诱导细胞凋亡,生长抑制;MOI为50时,U251-p53 PTEN生长抑制率明显高于U251-p53,并能出现细胞凋亡,而U251-p53仅出现少量细胞凋亡。结论p53基因可以通过细胞周期G0G1期阻滞及诱导细胞凋亡抑制胶质瘤细胞系U251的生长;PTEN基因可以促进p53基因对胶质瘤细胞系U251的生长抑制作用,并能增加U251细胞对p53基因诱导凋亡的敏感性。  相似文献   

2.
目的 探讨微小核糖核酸592(miR-592)对神经胶质瘤细胞株U251凋亡的影响。方法 首先通过定量聚合酶链反应(PCR)分析miR-592在28份神经胶质瘤与其临近癌旁组织中的表达水平; 随后向U251细胞转染miR-592的拟合物,并通过流式细胞技术分析miR-592过表达对U251细胞凋亡的影响; 通过生物信息学分析找到miR-592的潜在靶分子,并通过荧光素酶双报告实验以及蛋白免疫印迹法等进行验证; 进一步转染U251细胞Runx2的下调siRNA,绘制细胞的生长曲线,检测U251细胞的凋亡率。结果 对28份神经胶质瘤组织和正常组织的定量PCR分析发现,miR-592在肿瘤组织中明显低表达; miR-592过表达能明显抑制U251细胞的生长; 流式细胞分析显示,miR-592显著促进U251细胞凋亡:对照组晚期凋亡率为(7.2±0.68)%,而转染miR-592组晚期凋亡率为(17.47±1.45)%; 荧光素酶双报告实验以及蛋白免疫印迹法实验发现miR-592直接靶向Runx2的3'-UTR来抑制Runx2蛋白的表达水平。结论 miR-592通过直接靶向Runx2来诱导神经胶质瘤细胞凋亡,进而抑制细胞生长。  相似文献   

3.
目的探讨重组人类肝细胞生长因子(rhHGF)对胶质瘤细胞增殖及血管内皮生长因子(VEGF)表达的影响。方法用5、10、20、30μg/L不同浓度的rhHGF作用于体外培养的U251胶质瘤细胞并设立空白对照组,甲基噻唑基四唑(MTT)法检测细胞增殖;免疫组化及Westernblot检测增殖细胞核抗原(PCNA)和VEGF表达。结果与对照组相比,rhHGF明显促进U251细胞的增殖和生长,其作用呈时间效应关系和一定浓度范围内的剂量效应关系(P<0.05)。Westernblot及免疫组化检测显示,20μg/LrhHGF作用后U251细胞PCNA和VEGF表达上升,呈时间依赖性(P<0.05);细胞外调节蛋白激酶(ERK)抑制剂PD98059呈剂量依赖性抑制rhHGF诱导的PCNA和VEGF表达增加。结论rhHGF可能通过ERK信号途径促进胶质瘤细胞增殖和VEGF表达,从而影响胶质瘤的生长和血管发生。  相似文献   

4.
目的利用RNA干扰(RNA interference,RNAi)技术特定沉默胶质瘤U251细胞株的血小板源生长因子-B(PDGF-B)基因,观察其对U251细胞株细胞凋亡和增殖的影响。方法利用脂质体将针对PDGF-B基因的siRNA转染进入U251细胞,利用实时荧光定量多聚核苷酸链式反应(RTPCR)检测PDGF-B基因表达;Western blot检测显示siRNA转染组PDGF-B蛋白表达,采用MTT法检测胶质瘤U251细胞的增殖,应用流式细胞计数观察抑制PDGF-B基因后胶质瘤U251细胞的凋亡情况。结果 RT-PCR检测PDGF-B基因表达明显下降;Western blot检测显示siRNA转染组PDGF-B蛋白表达明显抑制(抑制率60%),MTT结果显示siRNA转染组U251细胞增殖较对照组明显降低;流式细胞学检测提示降低PDGF-B在胶质瘤细胞的表达能抑制胶质瘤细胞的有丝分裂,促进细胞的凋亡。结论构建针对胶质瘤细胞PDGF-B的RNA干扰质粒并转染人胶质瘤U251细胞株后,可明显抑制U251细胞株PDGF的表达,对人胶质瘤U251细胞株有明显的生长抑制和促进凋亡作用。  相似文献   

5.
目的 观察敲低微小RNA-155(miR-155)的表达对人胶质瘤细胞系U251细胞增殖和凋亡的影响.方法 脂质体介导转染miR-155反义抑制序列(AS-miR-155)下调入胶质瘤U251细胞中miR-155的表达,同时设未转染组和无义序列转染组.实时定量聚合酶链式反应(qRT-PCR)检测转染后细胞miR-155的表达,四甲基偶氨唑盐(MTT)实验检测转染后细胞增殖活性,流式细胞术(FCM)检测转染后细胞周期变化和凋亡情况.结果 与未转染组和无义序列转染组相比,miR-155 反义抑制序列转染组细胞miR-155表达下降;MTT实验结果显示细胞生长受抑;流式细胞术结果可见细胞出现G0/G1期阻滞,细胞凋亡率增高.结论 反义miR-155可抑制U251胶质瘤细胞生长增殖,促进其凋亡.miR-155可能成为治疗胶质瘤的候选靶标.  相似文献   

6.
目的 探讨miR-127-3p在神经胶质瘤中的表达水平差异及生物学作用。方法 用RT-PCR法检测神经胶质瘤患者及健康人群脑脊液中miR-127-3p相对表达水平; 用RT-PCR法检测人神经胶质瘤细胞株和人正常神经胶质细胞中的miR-127-3p相对表达水平; 用瞬时转染法上调神经胶质瘤细胞U251中的miR-127-3p相对表达水平,用MTT法检测细胞增殖,用流式细胞术检测细胞凋亡,用Western blot检测凋亡相关蛋白bcl-2、Mcl-1和bax表达水平; Targetscan等在线靶基因预测软件预测miR-127-3p的靶基因,并采用双荧光素酶报告试验和Western blot验证miR-127-3p与靶基因之间的直接作用关系。结果 神经胶质瘤患者(1.33±0.12)脑脊液中的miR-127-3p相对表达水平低于健康人群(3.62±0.26)(t=5.867,P=0.004); U251(0.59±0.05)、U373(0.96±0.08)、U87(0.77±0.03)、SHG44(1.28±0.05)中miR-127-3p相对表达水平均低于人脑正常胶质细胞株HEB(3.64±0.26)(P<0.01); 转染后24、48、72 h 150组、100组和50组细胞吸光度值均低于对照组(P<0.05),并且随着miR-127-3p mimics转染水平增高,U251细胞吸光度值越低; miR-127-3p mimics转染组(39.3±4.6%)细胞早期凋亡率高于对照组(7.2±0.6%)(P<0.05); miR-127-3p mimics转染组(9.3±2.3%)细胞晚期凋亡率高于对照组(2.4±0.5%)(P<0.05); mimic转染组(0.119±0.008)U251细胞bcl-2蛋白表达水平低于对照组(0.556±0.039),mimic转染组(0.168±0.015)U251细胞bax蛋白表达水平高于对照组(0.086±0.006),mimic转染组(0.144±0.009)U251细胞Mcl-1蛋白表达水平低于对照组(0.426±0.028)(P均<0.05); 双荧光素酶报告基因实验显示,只有当MAPK4-WT-3' UTR与miR-127-3p mimic共同转染时荧光素酶活性被抑制,这提示miR-127-3p能与MAPK4直接结合,miR-127-3p mimic转染组(0.121±0.003)U251细胞MAPK4蛋白表达水平低于对照组(0.467±0.028)(P<0.05)。结论 miR-127-3p在神经胶质瘤患者脑脊液中呈低表达,上调miR-127-3p能抑制神经胶质瘤U251细胞增殖,促进其凋亡,其机制可能与调控Bcl凋亡相关基因及抑制靶基因MAPK4有关。  相似文献   

7.
目的 研究从海葵组织中提取的海葵毒素(Phyllodiscus semonii toxin,PsTX)对人神经胶质瘤细胞(U251)凋亡的诱导作用及其可能机制.方法 MTT法检测PsTX对肿瘤细胞的增殖抑制率;原位末端脱氧核糖苷肽转移酶分析法(TUNEL)及DNA Ladder法检测PsTX对肿瘤细胞的凋亡诱导作用;免疫组织化学染色显示Fas蛋白在U251细胞中的表达.结果 PsTX对人神经胶质瘤细胞具有明显的生长抑制及促凋亡作用,PsTX诱导Fas在人神经胶质瘤细胞膜上表达增高.结论 PsTX可能通过Fas途径诱导人神经胶质瘤细胞凋亡.  相似文献   

8.
目的探讨Survivin拮抗肽对人胶质瘤U251细胞体外增殖的抑制作用及细胞周期的影响。方法将U251细胞与不同浓度的Survivin拮抗肽进行体外培养,采用四甲基偶氮唑蓝法测定不同浓度的Survivin拮抗肽对U251细胞的生长抑制率;采用流式细胞仪分析细胞周期与细胞凋亡。结果浓度为5、10、20ug/ml的Survivin拮抗肽均能抑制U251细胞的生长,且抑制率与Survivin拮抗肽浓度及作用时间成正比(P〈0.01)。20ug/ml Survivin拮抗肽作用U251细胞72h,抑制率达63.33%。流式细胞仪结果显示,终浓度为5、10、20ug/ml Survivin拮抗肽亦能促进U251细胞凋亡,且随作用浓度增大及作用时间延长凋亡率明显上升(P〈0.01);20ug/ml Survivin拈抗肽作用U251细胞72h,凋亡率为31.29%。不同浓度的Survivin拮抗肽作用U251细胞72h,随作用浓度增大,G2/M期细胞构成比明显上升(P〈0.01)。结论Survivin拮抗肽对U251细胞增殖具有抑制作用和促进凋亡,其抗胶质瘤细胞增殖作用机制可能为诱导肿瘤细胞凋亡,调控肿瘤细胞周期。  相似文献   

9.
目的探讨盐酸小檗碱(ber)诱导人脑胶质瘤细胞U251凋亡及其与HERG钾离子通道表达相关性。方法使用不同浓度的ber处理人胶质瘤细胞U251,采用四甲基偶氮唑盐(MTT)染色法测定细胞增值率,Hoechst33258荧光染色法观察细胞形态学改变,流式细胞术测定细胞凋亡率,分别采用实时荧光定量PCR与Western Blotting检测HERG钾通道的RNA及蛋白的表达情况。结果 MTT法检测显示细胞抑制率呈浓度与时间依赖性,且随药物浓度增加而增大(P0.05),其24 h的半数抑制浓度(IC50))是(8.78±0.20)μmol/l;Hoechst33258荧光染色法检测表明处理组出现典型的凋亡特征;且流式细胞术检测结果表明随着ber的剂量增加U251细胞的早期凋亡率及晚期凋亡率逐渐增大(P0.05);RT-PCR与Western Bloting检测结果显示ber处理后U251细胞的HERG钾通道的RNA含量及蛋白的表达均上调,且随着药物浓度的增高而增高。结论在体外ber可诱导人胶质瘤细胞系U251的凋亡,并可能通过上调HERG蛋白的表达抑制U251增殖。  相似文献   

10.
目的 研究生长抑制因子4(ING4)在脑胶质瘤中的表达和姜黄素(curcumin)对脑胶质瘤的治疗作用,揭示curcumin抗脑胶质瘤作用的分子机制。方法 体外培养U251胶质瘤细胞并以不同浓度curcumin处理细胞;以药物敏感试验和流式细胞仪分别检测curcumin对胶质瘤细胞生长和细胞周期的影响,以DNA梯度凝胶电泳检测细胞凋亡,以Western blot分析curcumin处理后蛋白表达变化。结果 ING4蛋白在正常神经细胞中高表达,在U251细胞中几乎不表达。低剂量curcumin对U251细胞无明显抑制作用,而高剂量curcumin对U251细胞存在明显的生长抑制作用,生长抑制率达35%。10μMcurcumin作用24h后,U251细胞中ING4蛋白表达水平显著增加。结论 高剂量curcumin通过诱导ING4表达上调,抑制脑胶质瘤细胞体外生长。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
Hepatic Considerations in the Use of Antiepileptic Drugs   总被引:5,自引:4,他引:1  
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.  相似文献   

14.
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.  相似文献   

15.
S. FELDMAN 《Epilepsia》1971,12(3):249-262
  相似文献   

16.
Neonatal Seizures: Problems in Diagnosis and Classification   总被引:6,自引:5,他引:1  
Eli M. Mizrahi 《Epilepsia》1987,28(S1):S46-S54
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.  相似文献   

17.
Valproate Monotherapy in the Management of Generalized and Partial Seizures   总被引:4,自引:2,他引:2  
David W. Chadwick 《Epilepsia》1987,28(S2):S12-S17
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.  相似文献   

18.
Carbamazepine Efficacy and Utilization in Children   总被引:4,自引:3,他引:1  
W. Edwin Dodson 《Epilepsia》1987,28(S3):S17-S24
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.  相似文献   

19.
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.  相似文献   

20.
Special Pharmacokinetic Considerations in Children   总被引:4,自引:2,他引:2  
W. Edwin Dodson 《Epilepsia》1987,28(S1):S56-S69
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号