白藜芦醇抑制SHG-44胶质瘤细胞生长实验研究

目的探讨白藜芦醇(Res)在体外诱导脑胶质瘤SHG-44细胞凋亡并抑制其生长的作用。方法四甲基偶氮唑蓝(MTT)比色法测量不同剂量的Res作用6h、24h和48h后对SHG-44胶质瘤细胞增殖的影响。HE染色、Hoechst33342荧光染色观察细胞形态改变,DNAladder检测细胞DNA裂解情况,流式细胞仪用异硫氰酸荧光素标记的膜联蛋白V(AnnexinV-FITC)和碘化丙啶(PI)双染检测凋亡率,并测定细胞周期的改变。结果Res明显抑制SHG-44细胞的生长和增殖(P<0.01),呈浓度及时间依赖性反应;Res所致的SHG-44胶质瘤细胞凋亡为浓度依赖关系,随着浓度的增高,凋亡更明显。此凋亡细胞周期主要发生G1期比例升高,S、G2期比例降低。结论Res明显抑制SHG-44细胞生长并诱导其发生凋亡和细胞周期改变,为Res用于治疗脑胶质细胞瘤提供了实验依据。     

三氧化二砷对人胶质瘤U251细胞生长及端粒酶活性的影响

目的探讨三氧化二砷（As2O3）对人胶质瘤U251细胞的生长及端粒酶活性的影响。方法采用倒置显微镜和透射电镜观察As2O3处理后U251细胞形态变化;四甲基偶氮唑蓝比色法观察As2O3对U251细胞增殖的影响;流式细胞术检测细胞凋亡;端粒重序列扩增酶联免疫吸附实验（TRAP-ELISA）结合聚丙烯酰胺凝胶电泳（TRAP-PAGE）银染法检测As2O3处理后U251细胞端粒酶活性变化。结果倒置显微镜下观察到：As2O3处理后的U251细胞逐渐变圆、脱壁,细胞间接触变松,细胞质中颗粒增多,增殖变慢,细胞周围碎片增多;透射电镜下见较多典型凋亡细胞。1～8μmol/LAs2O3明显抑制U251细胞增殖,诱导其凋亡;并使端粒酶活性逐渐下降,该作用呈浓度和时间依赖性。结论 As2O3对人胶质瘤U251细胞株生长具有显著抑制作用,其机制可能与As2O3能够抑制U251细胞的端粒酶活性密切相关。     

NAC调控HIF-1α抑制胶质瘤细胞生长的作用研究

目的研究N-乙酰半胱氨酸(NAC)通过抑制低氧诱导因子-1α(HIF-1α)表达,进而抑制SHG-44胶质瘤细胞生长的作用研究。方法对照组为常规培养的SHG-44胶质瘤细胞,NAC组为常规培养基础上加入N-乙酰半胱氨酸,两组培养48 h后实时荧光定量逆转录酶聚合酶联反应(RTPCR)检测HIF-1αmRNA的表达,四甲基偶氮唑盐比色法(MTT)检测SHG-44胶质瘤细胞增殖情况,流式细胞仪检测SHG-44胶质瘤细胞凋亡情况。结果 NAC组HIF-1αmRNA的表达水平明显低于对照组,差异有统计学意义(P0.05)。MTT检测SHG-44胶质瘤细胞增殖情况,NAC组明显低于对照组,差异有统计学意义(P0.05)。NAC组早期凋亡率、晚期凋亡及坏死率均高于对照组,差异有统计学意义(P0.05)。结论 N-乙酰半胱氨酸具有下调低氧诱导因子-1α表达,进而抑制SHG-44胶质瘤细胞生长,加速凋亡的作用。     

华蟾素对人脑胶质瘤细胞SHG44增殖及凋亡的影响

目的初步探讨华蟾素对人脑胶质瘤细胞SHG44增殖、细胞周期分布及凋亡的影响机制。方法利用MTT法、流式细胞仪检测华蟾素对人脑胶质瘤细胞SHG44增殖及细胞周期变化的影响。AO／EB染色、透射电镜观察人脑胶质瘤细胞SHG44凋亡细胞形态学的变化。Westernblot检测Bcl-2与Caspase8蛋白的表达。结果华蟾素（1μg／ml、10μg／ml）对细胞株增殖具有显著抑制作用（P〈0．05）,并呈时间和浓度依赖性。沆式细胞仪检测可见凋亡峰,Go／G。期细胞明显增多（P〈0．05）;华蟾素作用后可使Bcl-2蛋白表达降低．Caspase8蛋白表达升高。结论华蟾素可调控人脑胶质瘤细胞SHG44的周期进程,诱导Bcl-2及Caspase8差异性表达,且具有抑制肿瘤细胞增殖及促凋亡的作用。     

甘草查尔酮A对胶质瘤的增殖抑制及促凋亡作用机制研究

目的探讨甘草查尔酮A(LCA)对人胶质瘤U87、U251细胞的增殖抑制和促凋亡作用及其机制研究。方法通过四甲基偶氮唑蓝(MTT)比色法检测细胞增殖抑制作用,并计算出半数抑制浓度(IC50),按IC50和100μM不同浓度进行分组。采用倒置显微镜观察细胞形态,流式细胞术检测细胞凋亡以及Western Blot从蛋白水平检测凋亡相关分子的改变情况。结果 MTT显示LCA对人胶质瘤U87、U251细胞具有明显的增殖抑制作用,呈浓度及时间依赖性,LCA对U87、U251细胞48 h的IC50值分别为61.54μM和53.02μM,倒置显微镜下观察细胞密度减少,形态发生明显改变。流式细胞术结果显示,LCA可促进胶质瘤U87、U251的细胞凋亡(P0.01)。Western Blot结果显示,LCA干预后可显著降低胶质瘤U87、U251细胞内Bcl-2的表达(P0.01),相反,增加Bax的表达(P0.05),呈浓度依赖性。结论 LCA对胶质瘤U87、U251细胞具有明显的增殖抑制作用,可能通过内源性凋亡途径诱导其凋亡。     

铜绿假单胞菌制剂对大鼠C6胶质瘤细胞作用的体外机制研究

[摘要] 目的 初步探讨铜绿假单胞菌制剂（PA-MSHA）对体外培养的大鼠C6胶质瘤细胞的增殖抑制机制。方法 体外培养大鼠C6胶质瘤细胞, MTT比色法测定不同时间、不同浓度PA-MSHA对C6胶质瘤细胞的增殖抑制率。Hochest 33258染色,荧光显微镜下检测细胞凋亡,流式细胞仪检测PA-MSHA对C6细胞周期的影响。结果MTT比色法结果提示,细胞生长抑制率与药物作用时间和剂量正相关。24小时和48小时IC50值分别为(5.80±1.79)× 108cfu/ml和(3.90±2.14) × 108cfu/ml。Hochest33258染色可见明显的细胞凋亡形态学改变,流式细胞仪检测,药物作用组可见典型的亚二倍体峰即凋亡峰（AP）,且随浓度加大S期比例明显增多。 结论 铜绿假单胞菌(PA-MSHA)制剂对体外培养的C6胶质瘤细胞具有增殖抑制作用,且呈时间剂量依赖性。其机制可能与诱导细胞凋亡及S期阻滞有关。     

鸦胆子油乳对SKMG-4胶质瘤细胞抑制作用研究

目的探讨鸦胆子油乳注射液对人脑胶质瘤细胞增殖的影响及其作用机制。方法体外培养人脑胶质瘤细胞SKMG-4;利用四甲基偶氮唑盐(MTT)比色法检测鸦胆子油乳注射液对SKMG-4增殖的抑制作用;利用流式细胞术(FCM)分析药物处理前后SKMG-4的细胞周期变化;应用免疫组化检测药物处理前后bcl-2表达情况。结果 MTT比色法显示鸦胆子油乳注射液对SKMG-4细胞增殖的抑制作用呈剂量依赖性,当浓度为5 g/L时,对SKMG-4细胞增殖的抑制率达到72.1%±2.2%(P<0.05)。流式细胞仪分析显示,用5 g/L鸦胆子油乳注射液培养48 h,细胞周期中G1期细胞所占比例增高,S期所占比例降低。免疫组化显示随着鸦胆子油乳注射液作用剂量的增加,bcl-2基因的表达被明显抑制。结论中药鸦胆子油乳注射液能通过调控细胞周期,抑制bcl-2凋亡基因的表达抑制人脑胶质瘤细胞SKMG-4的增殖。     

I型γ-分泌酶抑制剂对恶性胶质瘤细胞株增殖及凋亡的影响

目的 探讨I型γ-分泌酶抑制剂(GSI-I)对U87、U251胶质瘤细胞的增殖抑制及诱导凋亡作用.方法 应用GSI-I作用于U87、U251胶质瘤细胞,通过MTT法观察GSI-I对上述两种细胞的增殖抑制作用,通过流式细胞仪检测GSI-I对该两种细胞细胞周期的影响及诱导凋亡的作用.结果RT-PCR及实时定量荧光RT-PCR结果显示,GSI-T可明显抑制胶质瘤细胞中Notch通路的活性,主要体现为Notch通路的靶基因Hes-1表达明显下调.MTT检测结果显示2.5μmol/L及以上浓度的GSI-I对U87及U251胶质瘤细胞有明显的增殖抑制作用.与对照组比较,差异有统计学意义(P<0.05),且该抑制作用呈剂量依赖型增加.流式细胞检测结果显示GSI-I主要使U87胶质瘤细胞的细胞周期阻滞在G1期而抑制细胞增殖,对于U251胶质瘤细胞则主要通过诱导凋亡来抑制增殖.结论 GSI-I可明显抑制U87及U251胶质瘤细胞的增殖并诱导凋亡,为恶性胶质瘤的临床治疗提供了理论参考依据.     

~(125)I诱导大鼠脑内胶质瘤凋亡实验研究

目的研究125I诱导人脑胶质瘤细胞系SHG-44体内外凋亡的可能性及其机制。方法体外培养SHG-44细胞,采用流式细胞仪法检测125I诱导SHG-44细胞凋亡及对细胞周期影响,采用立体定向的方法建立大鼠脑内人胶质瘤模型,1周后经MRI检测后,于肿瘤区接种125I,2周后复查MRI检测肿瘤大小,3周后处死大鼠,取对照组及肿瘤周边组织及肿瘤组织行Bcl-2、p53免疫组织化学染色。结果SHG-44细胞接种1周,MRI示脑内形成实体瘤;125I可抑制肿瘤生长,诱导细胞凋亡,延长荷瘤鼠生长周期,抑制Bcl-2基因表达,促进p53蛋白表达。结论125I具有体内、外抑制SHG-44细胞增殖,诱导凋亡的作用;其诱导凋亡机制可能与抑制Bcl-2蛋白表达,促进p53蛋白表达有关。     

125Ⅰ诱导大鼠脑内胶质瘤凋亡实验研究

目的研究125Ⅰ诱导人脑胶质瘤细胞系SHG-44体内外凋亡的可能性及其机制.方法体外培养SHG-44细胞,采用流式细胞仪法检测125Ⅰ诱导SHG-44细胞凋亡及对细胞周期影响,采用立体定向的方法建立大鼠脑内人胶质瘤模型,1周后经MRI检测后,于肿瘤区接种125Ⅰ,2周后复查MRI检测肿瘤大小,3周后处死大鼠,取对照组及肿瘤周边组织及肿瘤组织行Bcl-2、p53免疫组织化学染色.结果SHG-44细胞接种1周,MRI示脑内形成实体瘤;125I可抑制肿瘤生长,诱导细胞凋亡,延长荷瘤鼠生长周期,抑制Bcl-2基因表达,促进p53蛋白表达.结论125Ⅰ具有体内、外抑制SHG-44细胞增殖,诱导凋亡的作用;其诱导凋亡机制可能与抑制Bcl-2蛋白表达,促进p53蛋白表达有关.     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.