RNA干扰抑制Nogo-A基因表达及对PC12细胞凋亡的影响

为研究Nogo-A基因沉默对细胞凋亡的影响,本文构建了靶向Nogo-A的短发夹样RNA(short hairpin RNA,shRNA)真核表达载体并经脂质体转染到培养的PC12细胞。分别以逆转录聚合酶链反应(RT-PCR)和免疫印迹法检测转染48h后Nogo-A mRNA及蛋白表达的变化。在转染后不同时间应用四甲基偶氮唑盐(MTT)法检测细胞增殖活性,用原位末端标记(TUNEL)法及流式细胞仪检测细胞凋亡率。结果显示:由shRNA产生的小干扰RNA(siRNA)可有效抑制PC12细胞Nogo-A基因的表达。Nogo-A siRNA处理组细胞的增殖活性增加、凋亡率明显下降。本结果提示,Nogo-A基因可能与细胞凋亡有关。     

院外纳曲酮治疗酒精依赖的疗效观察

目的 :评估纳曲酮院外治疗酒依赖的临床疗效。方法 :采用随机对照的方法 ,分别对纳曲酮组和安慰剂组各 2 3例和 2 2例 ,作总疗程 12周的临床观察。结果 :纳曲酮显著降低病人对酒精的渴求程度 ,其疗后 4、 8、 12周的保持率分别为 91 3 %、 77 9%、 73 3 % ,明显高于安慰剂。纳曲酮的副作用与安慰剂相当 ,其主要副作用为轻度的恶心、厌食、头晕。结论 :纳曲酮是一种安全有效的治疗酒依赖的药物     

API0134对大鼠血浆和血小板血栓素B2生成与血小板聚集的影响

用放射免疫分析法和比浊法测定ＰＡＩ０１３４对大鼠血浆血栓素Ｂ２浓度，血小板ＴＸＢ２生成血小板聚集的影响。静脉注射ＡＰＩ０１３４７０ｍｇ或１００ｍｇ．ｋｇ显著降低血浆ＴＸＢ２浓度，其降低２率分别为３８．８％和５１．６％，ＡＰＩ０１３４明显抑制ＡＤＰ诱导的大鼠血小板聚集和ＴＸＢ２生成，抑制率分别为２７．８％，３９．５％，和４１．４％，５３．６％，两抑制率间呈显著正相关。     

APOE is a potential modifier gene in an autosomal dominant form of frontotemporal dementia (IBMPFD).

PURPOSE: Inclusion-body myopathy, Paget's disease of bone and frontotemporal dementia is an adult-onset autosomal dominant illness (IBMPFD) caused by mutations in the valosin-containing protein (VCP) on chromosome 9p21.1-p12. The penetrance of the gene is 82% for myopathy, 49% for Paget's disease, but may be as low as 30% for frontotemporal dementia. Modifier genes could account for decreased frontotemporal dementia penetrance. In this study apolipoprotein-E (APOE) was evaluated for this role in IBMPFD families based on its known modifier effect in Alzheimer's disease. METHODS: From a database of 231 members of 15 families, 174 had APOE genotype available for analysis. Logistic regressions on APOE genotype and frontotemporal dementia were performed, using appropriate covariates. RESULTS AND CONCLUSION: FTD was associated with APOE 4 genotype (P=0.0002), myopathy (P=0.0006), and age (P=0.01), but not microtubule associated protein tau (MAPT) H2 haplotype (P=0.5) or gender (0.09) after adjustment for membership in pedigrees with at least one APOE 4 genotype. These data suggest a potential link between APOE 4 genotype and the specific form of frontotemporal dementia found in IBMPFD. The molecular basis of this link bears further investigation. We did not observe an association of frontotemporal dementia and H2 MAPT haplotype.     

Activation of NR1a/NR2B receptors by soluble factors from APP-stimulated monocyte-derived macrophages: implications for the pathogenesis of Alzheimer's disease

Amyloid-beta peptide (Abeta), the major component of amyloid plaques, can activate brain mononuclear phagocytes (MP; macrophages and microglia), leading to their secretion of neurotoxins. Recent studies strongly suggest that MP-mediated neurotoxicity plays an important role in the pathogenesis of Alzheimer's disease (AD). To further explore this notion, human monocyte-derived macrophages (MDM) were stimulated with naturally secreted alpha-processing soluble amyloid precursor protein/p3 (alphaAPPs/p3) or beta-processing APP/Abeta (betaAPPs/Abeta). MDM conditioned media (MCM) was recovered and tested for its ability to activate recombinant N-methyl-d-aspartate (NMDA) receptor subtype NR1a/NR2B expressed in Xenopus oocytes. Pressure ejection of alphaAPPs/p3- and betaAPPs/Abeta-stimulated MCM produced inward currents of 59.5 +/- 8.9 nA (mean +/- S.E.M., n = 31) and 111.1 +/- 21.0 nA (n = 42) in NR1a/NR2B-expressing oocytes, respectively. The MCM-induced currents were concentration dependent and blocked by 50 microM of the NMDA receptor antagonist 2-amino-5-phosphnovalerate, but not by a non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (20 microM). The alphaAPPs/p3- and betaAPPs/Abeta-stimulated MCM placed in non-injected oocytes failed to generate inward current. These results demonstrate that APPs/Abeta-stimulated MCM directly activate NMDA receptor subtypes relevant in the pathogenesis of AD.     

含银介孔二氧化硅-壳聚糖复合材料的制备与性能研究

目的探讨含银介孔二氧化硅-壳聚糖复合材料(Ag/MSN-Chi)的制备方法及其微观表征、细胞毒性、吸水性能、抗菌性能及止血性能。 方法以正硅酸乙酯为前驱体，十六烷基三甲基溴化铵为致孔剂，采用离子交换法在介孔二氧化硅纳米粒子(MSN)中引入银离子，制备出具有抗菌作用的新型有序的含银介孔二氧化硅纳米粒子(Ag/MSN)材料。再利用烷基化壳聚糖负载Ag/MSN，制备出Ag/MSN-Chi。根据所用材料不同将实验分为实验组和空白对照组，实验组又分为3个亚组：MSN组、Ag/MSN组、Ag/MSN-Chi组，空白组为不加任何材料的阳性对照。计算MSN和Ag/MSN的比表面积、孔容、孔径和Ag/MSN与Ag/MSN-Chi的电荷。并通过吸水实验、体外凝血实验、抗菌实验对MSN、Ag/MSN和Ag/MSN-Chi的细胞毒性、吸水性能、止血性能及抗菌性能进行评价，计算细胞相对存活率、吸水率、凝血酶原时间(PT)、凝血活酶时间(APTT)及抑菌率。取健康成年新西兰大白兔18只，随机分成3组：对照组(采用医用纱布处理)、Ag/MSN组(采用Ag/MSN处理)、Ag/MSN-Chi组(采用Ag/MSN-Chi处理)，每组6只，建立肝创伤出血模型，计算止血时间。数据比较采用方差分析和t检验。 结果MSN的比表面积为(523.8±12.4) m²/g、孔容为(1.2±0.4) m³/g、孔径为(3.5±0.9) nm；Ag/MSN的比表面积为(521.6±11.7) m²/g、孔容为(1.15±0.5) m³/g、孔径为(3.6±0.7) nm，2种材料的比表面积、孔容、孔径比较差异均无统计学意义(t＝0.224、0.135、0.015，P值均大于0.05)。经测量，Ag/MSN的Zeta电位为－19.7 mV，Ag/MSN-Chi的Zeta电位为10.27 mV，表明Ag/MSN表面电荷从负值变为正值。Ag/MSN-Chi组、Ag/MSN组和MSN组与小鼠成肌细胞共培养1、4、7 d的细胞相对存活率比较，差异均无统计学意义(F＝2.61、4.72、3.52, P值均大于0.05)。Ag/MSN组吸水率分别与MSN组和Ag/MSN-Chi组比较，差异均无统计学意义(t＝0.482、1.159，P值均大于0.05)。经检测，Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组的PT比较，差异无统计学意义(F＝10.28，P>0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组APTT分别为(20.9±2.1)、(28.5±3.4)、(31.4±2.6)、(38.7±2.5) s，4组比较差异有统计学意义(F＝8.70，P<0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组APTT分别与空白对照组比较，差异均有统计学意义(t＝9.443、4.186、3.506，P值均小于0.05)；Ag/MSN-Chi组APTT与Ag/MSN组比较，差异有统计学意义(t＝3.294，P<0.05)。MSN组在培养0.5、2、4、6、24 h 5个时间点抑菌率比较差异无统计学意义(F＝5.437，P>0.05)；培养0.5 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(99.7±5.2)%、(97.1±5.4)%，与培养0.5 h MSN组抑菌率(11.2±5.8)%比较，差异均有统计学意义(t＝19.678、18.775, P值均小于0.05)；培养24 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(73.2±5.1)%和(72.9±6.9)%，与MSN组(11.8±5.7)%比较，差异均有统计学意义(t＝13.904、11.825, P值均小于0.05)。Ag/MSN-Chi组、Ag/MSN组和对照组止血时间分别为(12.3±1.5)、(17.2±3.4)、(28.1±3.8) s，3组比较差异有统计学意义(F＝5.892，P<0.05)；Ag/MSN-Chi组和Ag/MSN组止血时间分别与对照组比较，差异均有统计学意义(t＝9.473、5.236, P值均小于0.05)；且Ag/MSN-Chi组与Ag/MSN组止血时间比较，差异有统计学意义(t＝3.230，P<0.05)。 结论Ag/MSN-Chi在不增加细胞毒性的基础上具有有较好的吸水性能、止血性能及抗菌性能。     

心血管组织钙化时内源性硫化氢系统下调

目的：观察心血管组织钙化时内源性硫化氢生成系统(CSE/H2S)的变化，以探讨内源性硫化氢在心血管组织钙化中的作用及血管钙化的细胞分子机制。方法：在维生素D3 (Vit D3)和尼古丁(nicotine)诱导大鼠血管钙化模型上，测定钙含量、［45Ca2+］沉积及碱性磷酸酶（ALP）活性判断心血管钙化程度,采用生化法测定血浆、心肌组织和主动脉H2S含量及CSE活性，半定量RT-PCR方法测定心血管组织CSE mRNA水平。结果：钙化组大鼠心肌组织钙含量较对照组高3.8倍,主动脉钙含量、［45Ca2+］ 沉积及ALP 活性分别较对照组高6.8倍、1.4倍和 1.9倍（P＜0.01）；钙化组大鼠血浆H2S含量较对照组低39%（P<0.01），心肌和主动脉组织的 H2S含量也分别较对照组低39%和31%，CSE mRNA表达也分别低28％和36％（P<0.01），CSE活性分别低56%和53%(P<0.01)。结论：钙化心血管组织CSE/H2S通路受抑制，内源性H2S生成减少。     

血管内皮生长因子和E26转录因子在乳腺癌中的表达及意义

目的 试图揭示血管内皮生长因子（VEGF）和E26转录因子（E26 transformation-specificl,ETS-1)在乳腺癌组织中的表达规律,探讨其在血管生成和肿瘤浸润转移中的作用机制。方法 应用原位杂交和免疫组织化学链霉素抗生物系－过氧化物酶复合物法（SP）法,检测48例乳腺癌组织中VEGF和ETS－1的mRNA和蛋白的表达。结果 乳腺癌细胞高表达VEGF mRNA和蛋白,阳性率分别为75％（36／48）,70．8％（34／48）,而血管内皮细胞几乎不表达;ETS－1既表达在乳腺癌细胞,也表达在血管内皮细胞。癌细胞中mRNA和蛋白表达阳性率分别为85．4％（41／48）,79．2％（38／48）;VEGF和ETS－1高表达组的血管密度明显高于低表达组（均P＜0．01）;VEGF和ETS－1的表达与组织学分级和淋巴结转移密切相关,并且高表达组的微血管密度明显高于低表达组（P＜0．01）。结论 VEGF和ETS－1可促进乳腺癌血管形成,同时也促进肿瘤的浸润和转移;检测VEGF和ETS－1的表达可做为乳腺癌恶性度,浸润转移等生物学行为的参考指标。     

Predicting intellectual outcome among children treated with 35-40 Gy craniospinal irradiation for medulloblastoma

Fifty children diagnosed with medulloblastoma completed 188 psychological evaluations using the Wechsler Intelligence Scales for Children (D. Wechsler, 1974, 1991) over a 7-year study period following 35-40 Gy postoperative craniospinal irradiation. Random coefficient models were used to predict the trend in the children's intellectual performance as a function of time since diagnosis, with both patient and treatment variables as parameters of this function. A quadratic model demonstrated a delay prior to decline in performance for older patients, whereas the younger patients showed an immediate loss of performance with a plateau at approximately 6 years postdiagnosis. A steeper decline was found for those with higher baseline performance. Clinicians may use the proposed predictive model to identify those patients who are at risk of significant intellectual decline.     

pH Sensitivity of non-synaptic field bursts in the dentate gyrus

Under conditions of low [Ca(2+)](o) and high [K(+)](o), the rat dentate granule cell layer in vitro develops recurrent spontaneous prolonged field bursts that resemble an in vivo phenomenon called maximal dentate activation. To understand how pH changes in vivo might affect this phenomenon, the slices were exposed to different extracellular pH environments in vitro. The field bursts were highly sensitive to extracellular pH over the range 7.0-7.6 and were suppressed at low pH and enhanced at high pH. Granule cell resting membrane potential, action potentials, and postsynaptic potentials were not significantly altered by pH changes within the range that suppressed the bursts. The pH sensitivity of the bursts was not altered by pharmacologic blockade of N-methyl-D-aspartate (NMDA), non-NMDA, and GABA(A) receptors at concentrations of these agents sufficient to eliminate both spontaneous and evoked synaptic potentials. Gap junction patency is known to be sensitive to pH, and agents that block gap junctions, including octanol, oleamide, and carbenoxolone, blocked the prolonged field bursts in a manner similar to low pH. Perfusion with gap junction blockers or acidic pH suppressed field bursts but did not block spontaneous firing of single and multiple units, including burst firing. These data suggest that the pH sensitivity of seizures and epileptiform phenomena in vivo may be mediated in large part through mechanisms other than suppression of NMDA-mediated or other excitatory synaptic transmission. Alterations in electrotonic coupling via gap junctions, affecting field synchronization, may be one such process.