In situ and immunocytochemical localization of E-FABP mRNA and protein during neuronal migration and differentiation in the rat brain

The present study compares the temporal-spatial expression and tissue localization of the rat epidermal type fatty acid binding protein (E-FABP) (DA11/C-FABP/S-FABP/LEBP/KLBP) in the developing rat central nervous system (CNS). In situ hybridization (ISH) and immunocytochemistry (ICC) studies demonstrate that mRNA E-FABP and protein are expressed at high levels during neurogenesis, neuronal migration, and terminal differentiation. Migrating pyramidal cells in the cerebral cortex, Purkinje cells and deep nuclear neurons in the cerebellum, and neurons in the olfactory bulb and retina exhibited a strong E-FABP-like immunoreactivity (E-FABP-LI) throughout the entire process of differentiation and migration. The levels of E-FABP mRNA and protein were dramatically higher in prenatal and early postnatal neurons, as compared to adult neurons. The E-FABP antibody immunoreacted with growing neurites, and nuclear and cytoplasmic regions of neurons. The intracellular multiregional pattern of localization of E-FABP and its differential temporal expression during development, are consistent with its proposed role in transporting long chain free fatty acids and/or other hydrophobic ligands during neuronal differentiation and axon growth.     

Depression of long term potentiation in gerbil hippocampus following postischemic hypothermia

To investigate the mechanism of chronic cell death following postischemic hypothermia, the change of N-methyl- -aspartate receptor (NMDAR) were examined by immunohistochemistry of NMDAR1 and long-term potentiation (LTP) in the CA1 subfield of the gerbil hippocampus. At 1 week following postischemic hypothermia (32°C×4 h), all CA1 neurons survived; however, immunoreactivity of NMDAR1 increased in neuronal perikarya whereas decreased in dendrites in the CA1 neurons. The abnormality was still observed in remaining CA1 neurons at 1 month after hypothermia. LTP was also significantly depressed at 1 week after hypothermia. These results suggest that some abnormalities in the glutamate receptor may be caused by ischemia; such abnormality would persist in spite of hypothermia treatment, resulting in the depression of LTP.     

Modulation of dihydroxyphenylacetaldehyde extracellular levels in vivo in the rat striatum after different kinds of pharmacological treatment

We recently identified the direct product of dopamine (DA) by monoamine-oxidase (MAO) activity, dihydroxyphenylacetaldehyde (DOPALD) in the trans-striatal dialysate. Based on these findings, in this work, we directly measured the variations in DOPALD levels after various kinds of pharmacological treatment in rat striatal extracellular fluid. Using both reversible and irreversible MAO inhibitors, we found that MAO-A inhibition suppressed, whereas MAO-B inhibition did not modify DOPALD levels in the dialysate. The vesicular DA uptake blocker Ro 4-1284 led to an increase in extracellular DA and DOPALD, whereas the increase in extracellular DA obtained after administration of the plasma membrane DA uptake blocker GBR-12909 occurred without concomitant changes in DOPALD extracellular levels. Microinfusions of DA through the dialysis probe or systemic administration of L-DOPA increased striatal DOPALD to a greater extent compared with other DA metabolites, both in intact and in 6-hydroxydopamine (6-OHDA)-lesioned striatum. This study indicates that the direct product of MAO activity within the rat striatum derives from the activity of the isoenzyme MAO-A. The assay of DOPALD, together with DOPAC, represents a reliable tool to measure directly, in freely moving animals, DA oxidative metabolism. As recent studies have shown that microinfusions of exogenous DOPALD might induce cell death, pharmacological modulation of DOPALD levels might also be relevant for an understanding of the mechanisms involved in DA neurotoxicity.     

共轭亚油酸诱导人乳腺癌细胞(MCF-7)凋亡的作用

目的　为了研究共轭亚油酸单体 (c9,t11 CLA)对人乳腺癌细胞 (MCF 7)凋亡的影响。方法　采用细胞生长曲线 ,凋亡细胞的荧光显微镜和电镜观察、流式细胞光度术的检测以及p5 3蛋白表达的方法 ,观察了用不同浓度c9,t11 CLA(2 5、5 0、10 0和 2 0 0 μmol L)诱导MCF 7细胞凋亡作用。结果　c9,t11 CLA可明显抑制MCF 7细胞生长 ,8天的抑制率分别为 -6 0 %、4 5 2 %、99 0 %和 99 4 %。通过荧光显微镜和电镜技术观察到了发生凋亡的MCF 7细胞 ;用流式细胞光度术也检测到c9,t11 CLA可诱导MCF 7细胞产生凋亡 ,并随着c9,t11 CLA浓度的增加 ,细胞凋亡率逐渐增加 ;而p5 3蛋白表达则随着c9,t11 CLA浓度的增加呈现逐渐降低的趋势。结论　c9,t11 CLA可诱导MCF 7细胞产生凋亡 ,这可能是c9,t11 CLA抑制肿瘤细胞生长的机制之一。     

β-紫罗兰酮对人乳腺癌细胞抑制作用

目的　研究 β 紫罗兰酮对人乳腺癌细胞 (MCF 7)生长的影响。 方法　采用细胞核分裂 ,生长曲线 ,集落形成和DNA合成实验 ,观察了用不同浓度 β 紫罗兰酮 (2 5、5 0、10 0和2 0 0 μmol L)对MCF 7细胞生长作用。 结果　β 紫罗兰酮可明显抑制MCF 7细胞增殖、细胞核分裂、集落形成和细胞DNA的合成 ,随着剂量的增加 ,抑制作用增强 ,IC50 值为 10 4 μmol L。细胞核分裂的抑制率分别为 2 4h 12 88%～ 6 8 6 7%。 4 8h 2 0 79%～ 87 79% ;集落形成抑制率分别为 2 4h 14 11%～ 6 5 18% ,4 8h 6 5 8%～ 72 4 8% ;DNA合成实验抑制率为 2 4h 16 75 %～6 5 33% ,4 8h 35 10 %～ 81 89%。结论　β 紫罗兰酮可抑制MCF 7细胞的生长 ,其机制需要进一步探讨。     

DNA甲基转移酶1和CD11a基因在SLE患者中的表达

目的检测SLE患者外周血单核细胞(peripheral blood mononuclear cells,PBMC)中DNA甲基转移酶1(DNA methylatransferase1,DNMT1)和CD11a基因的表达水平,探讨DNMT1表达异常在SLE发病中的作用。方法提取8例SLE患者及12例正常人外周血单核细胞,以RT-PCR法检测DNMT1和CD11a基因的转录水平,采用两样本均数t检验比较分析SLE患者与正常人之间DNMT1与CD11a基因表达的差异;统计分析两种基因表达的相关性。结果正常人PBMC中DNMT1表达的均值为0.289±0.092,CD11a基因表达的均值为0.430±0.143;SLE患者PBMC中DNMT1表达均值为0.167±0.046,CD11a表达均值为0.875±0.331。SLE患者PBMC中DN-MT1表达水平明显低于正常人(T=3.479,P=0.003);CD11a基因表达水平明显高于正常人(T=4.196,P=0.001)。在正常人PBMC中,DNMT1与CD11a基因的表达没有相关性;在SLE患者PBMC中DNMT1与CD11a基因表达呈负相关性(r=-0.714 53,P=0.046 4),DNMT1表达下降与CD11a表达增加有相关性。结论SLE患者PBMC中DNMT1表达降低可能是造成DNA低甲基化的一个重要原因,因而与CD11a基因的过度表达有重要关系,进而导致SLE的发病。因此可以推测DNMT1可能是SLE发病机制中一个重要的内源性因素。     

补肾益气方对流产大鼠胎盘孕酮生成通路的影响

目的:探讨补肾益气方对流产大鼠胎盘孕酮生成通路中相关重要上游因素低密度脂蛋白受体(LDLR)、细胞色素P450链裂解酶(P450scc)、3β-羟基类固醇脱氢酶(3β-HSD)的影响及其与孕酮(P)分泌的关系。方法:溴隐亭皮内注射法建立流产大鼠模型,分别于孕1-8 d、1-11 d灌服补肾益气方药,黄体酮肌注作为阳性对照组,采用放免法测定大鼠血清P水平;RT-PCR技术检测LDLR、P450scc、3β-HSD在不同组动物胎盘中的mRNA表达。结果:模型组LDLR、P450scc、3β-HSD mRNA表达较正常对照组明显降低;中药组及黄体酮组不同程度提高模型大鼠胎盘LDLR、P450scc、3β-HSD mRNA表达,表达强度随孕天和给药时间逐渐升高,与血P有显著相关性。结论:补肾益气方清热益气、固肾安胎,能调控胎盘滋养细胞LDLR、P450scc、3β-HSD基因表达,促进孕激素合成分泌增加,从而达到保胎维持妊娠的目的。     

p38MAPK在17β-雌二醇和雷洛昔芬促成骨细胞増殖和分化中的作用

目的:观察p38MAPK信号转导通路在17β-雌二醇和雷洛昔芬促成骨细胞增殖和分化过程中的作用。方法:取第一继代BALB/c小鼠头盖骨成骨细胞,药物刺激组分别加入不同浓度17β-雌二醇或雷洛昔芬;含阻断剂组预先添加不同浓度的SB202190(p38MAPK的阻断剂)阻断信号转导通路,再加17β-雌二醇或雷洛昔芬,作用72h后用MTT法与PNPP法测定细胞的增殖能力和碱性磷酸酶活性。结果:加入雌激素或雷洛昔芬后,成骨细胞的增殖和分化明显增强,与空白对照组比较差异具有显著性意义(P<0·05);阻断p38MAPK信号转导通路后,细胞增殖分化受到明显抑制,与未阻断组比较差异具有非常显著性意义(P<0.01)。结论:p38MAPK在17β-雌二醇和雷洛昔芬诱导的小鼠成骨细胞的増殖和分化过程中发挥重要作用。     

普伐他汀促进对慢性脑缺血β淀粉样蛋白的清除

目的观察降血脂药普伐他汀对慢性脑缺血大鼠的β淀粉样蛋白(Aβ)水平的影响。方法39只雄性SD大鼠分为正常饮食组(6只),高脂饮食组随机分为空白对照组(7只)、普伐他汀服用组(7只)、单纯脑缺血组(9只)及普伐他汀加脑缺血组(10只),采用结扎双侧颈总动脉建立CVI模型,于术后1个月行为学试验后,测血脂及Aβ水平。取脑组织,行病理学分析及ELISA检测Aβ水平。结果未治疗组(空白对照、单纯脑缺血组)血脂水平升高,但无显著差异(p>0.05),治疗组为正常水平。与正常饮食组相比,其余各组均无明显运动功能障碍,第4周平台定位时间、搜索策略无显著性差异(p>0.05)。脑病理学呈慢性缺血性改变结构欠清晰,神经元固缩或均匀着色,但明显的细胞坏死改变较少见;白质疏松明显。ELISA显示单纯缺血组Aβ较对照组明显升高,而治疗组Aβ下降至略高于对照组水平。结论普伐他汀能够降低脑内Aβ水平,这种降脂外的调节Aβ代谢作用提示血脂代谢异常参与了AD发病。     

Long-term persistence of molecular disease after histological remission in low-grade gastric MALT lymphoma treated with H. pylori eradication. Lack of association with translocation t(11;18): a 10-year updated follow-up of a prospective study.

BACKGROUND: Localized low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma can regress after Helicobacter pylori eradication, but IgV(H) gene monoclonality may persist. We studied the long-term histological and molecular follow-up of 24 patients and the possible association of t(11;18) with the persistent monoclonality. PATIENTS AND METHODS: From January 1994, 24 untreated patients with stage I low-grade gastric MALT lymphoma associated with H. pylori were prospectively studied. They all received eradication treatment and were sequentially followed-up with endoscopies for histological and molecular studies. Rearrangement of the IgV(H) gene was studied by PCR analysis. MALT1 locus alterations were studied by FISH. RESULTS: Twenty-two of the 24 patients (91%) achieved disappearance of the lymphoma. Eighteen (82%) of the 22 histologically cured patients and 16 of the 19 (84%) with long follow-up had monoclonality. Three patterns of development of IgV(H) gene rearrangements were observed: four patients (21%) had polyclonal rearrangements; eight (58%) had maintained/intermittent monoclonality and four (21%) had occasional monoclonality, mostly after H. pylori reinfection. Only one patient (6%) with persistent monoclonality relapsed. The remaining 18 patients maintained the remission, despite the persistent monoclonality in 15, for a median of 66 months (range 20-113). t(11;18) was not found in any of the patients with persistent monoclonality. Time and the number of endoscopies performed were not related with the occurrence of monoclonality. CONCLUSIONS: In stage I low-grade gastric MALT lymphoma eradication of H. pylori achieves prolonged histological remission in 90% of patients, but molecular remission is not accomplished in most cases. Molecular disease persists for years, but is not associated with t(11;18).