银杏内酯A对海马神经细胞凋亡保护作用的研究

目的探讨银杏内酯A(GKA)对凋亡海马神经细胞的影响及机制。方法用MTT法分析GKA对原代培养海马神经细胞的毒性作用,用浓度分别为0.1、1、10μmol/L的GKA预处理神经细胞6h,再用50μmol/LSNP孵育神经细胞24h;用流式细胞仪分析各组凋亡情况,用RT-PCR和Westernblot分析bcl-2、bax和cpp32 mRNA和蛋白表达水平,用试剂盒测定各组Cpp32活性。结果流式细胞术结果显示GKA实验组凋亡率均显著低于SNP组(P<0.01);RT-PCR结果和WesternBlot结果表明,GKA可以对抗SNP,上调bcl-2表达,下调bax表达,不影响Cpp32表达,但能显著降低Cpp32的活性(P<0.01)。结论GKA可以对抗SNP,对海马神经细胞有保护作用。     

银杏苦内酯B对大鼠常压低氧性肺动脉高压的影响

银杏苦内酯Ｂ对大鼠常压低氧性肺动脉高压的影响程德云，陈文彬低氧血症可引起血小板激活因子（ＰＡＦ）合成明显增多，长期给动物应用ＰＡＦ可导致肺动脉高压和肺血管重建。应用特异性ＰＡＦ受体拮抗剂有助于深入了解ＰＡＦ在肺动脉高压中的作用，并探讨了ＰＡＦ受体拮抗...     

银杏内酯B对心肌缺血再灌注损伤保护作用的实验研究

目的观察银杏内酯B对心肌缺血再灌注(MI/R)损伤的保护作用,探讨其作用机制。方法采用冠状动脉结扎使心肌缺血30min再灌注2h的方法建立MI/R损伤大鼠模型,按随机数字表法分为模型组、银杏内酯B三个剂量组(2、4、8mg/kg)、假手术组(n=10),于术前1h和再灌注即刻分别进行尾静脉注射给药。取血清,测定CK、LDH、SOD活性及MDA含量;取心脏,测定心肌梗死面积。结果银杏内酯B高剂量可明显缩小MI/R损伤大鼠的心肌梗死面积,与模型组比较差异有统计学意义(P0.05);银杏内酯B高、中剂量可显著降低血清CK和LDH活性(P0.05或P0.01),低剂量可明显降低血清CK活力(P0.05);银杏内酯B各剂量组的血清SOD活性显著升高(P0.05或P0.01),血清MDA含量则明显降低(P0.01)。结论银杏内酯B预处理对MI/R损伤的保护作用与其减少自由基的产生、抑制脂质过氧化反应等有关。     

银杏苦内酯B对重症急性胰腺炎大鼠血浆细胞因子的影响

目的:观察重症急性胰腺炎(SAP)大鼠血浆中TNF-α,血小板活化因子(PAF),IL-10, IL-12,sTNFR的水平变化及其银杏苦内酯B(BN52021)的影响.方法:实验选用Wistar♂大鼠45只,随机分成SAP模型组(SAP,n=15),BN52021治疗组(BN,n=15)和阴性对照组(NC,n=15)．前两组以50 g／L牛磺胆酸钠逆行注入主胰管制成SAP模型,NC组开腹后仅翻动十二指肠并触摸胰腺数次关腹．制模15 min后,SAP组经股静脉以5 mL／mg注射生理盐水;BN组以BN52021(5 mg／kg)代替生理盐水静注．制模后分别于1,6,12 h采血,应用ELISA技术测定血浆TNF-α,PAF,IL-10,IL-12和sTNFR水平．结果:SAP组,NC组和BN组大鼠血浆TNF-α和PAF水平相比,具有显著性差异,SAP组(746．2±374．1,82．5±35．4 ng／L)显著高于NC组(385．1±86．3．1．1±1．9 ng／L),BN组(503．7±177．9,39．9±29．9 ng／L)显著低于SAP组(P<0．05)．血浆sTNFR水平三组相比存在明显差异,SAP组(488．7±363．8 ng／L)显著高于NC组(50．0±21．0 ng／L),BN组(883．4±552．5 ng／L)显著高于SAP组(488．7±363．8 ng／L)(P<0．05)．血浆IL-12三组相比存在明显差异,SAP组(97．1±55．9 ng／L)显著高于NC组(20．4±19．4 ng／L),BN组在1 h时相点(133．5±33．4 ng／L)显著高于SAP组(55．9±14．7 ng／L)(P<0．05)．血浆IL-10三组相比不存在明显差异(P>0．05)．结论:SAP大鼠促炎细胞因子和抗炎细胞因子均显著升高．BN52021能降低血浆促炎因子含量,提高IL-12和细胞因子拮抗剂sTNFR含量．     

银杏内酯A、B对豚鼠乳头肌细胞的电生理效应

目的：研究银杏内酯A、B（GA、GB）抗心肌缺血与抗心律失常的效应及其机制。方法：细胞内微电极方法记录乳头肌动作电位。灌流模拟缺血液造缺血模型以及在低钾台氏液中加入氯化铯灌流诱发延迟后除极（DAD）模型。观察GA、GB在生理、缺血状态下对乳头肌动作电位各项电生理参数以及DAD的影响。结果：生理条件下10^-6mol/LGA、GB使APD50分别缩短9．1％和6．2％；APD90分别缩短8．4％和5．9％。缺血状态下APD明显缩短、APA减小、RP及0期Vmax减小（P＜0．05－0．01）。GA、GB可延缓和减轻缺血引起的上述变化（P＜0．01），GA、GB可降低DADA的发生率（P＜0．01）。结论：银杏内酯A、B有缓解和改善心肌缺血作用，并可阻抑DAD的发生。     

银杏内酯B对胆固醇和载脂蛋白E4损伤海马神经元活性和生长的影响

目的探讨高胆固醇和载脂蛋白E4(apoE4)对海马神经元生长和活性的影响及银杏内酯B的保护作用。方法采用无血清培养基体外培养初生大鼠海马神经元,采用神经元特异性烯醇化酶免疫荧光进行鉴定。用160μg/ml的银杏内酯B处理海马神经元16h,40μg/ml25-OH-胆固醇和30μg/mlapoE4继续处理24h。MTT比色实验观察海马神经元生长活力的改变;Image-Proplus分析系统观察神经元最长突起长度和胞体长短经的改变。结果25-OH-胆固醇和apoE4降低海马神经元活性,抑制海马神经元突起的生长,与单纯apoE4和单纯胆固醇相比有显著性差异;银杏内酯B对神经元活性有提高趋势,但与模型组无显著差异(P>0.05),银杏内酯B可以有效促进损伤神经元突起生长,与模型组相比有显著差异(P<0.05)。结论高胆固醇在apoE4环境下损伤海马神经元,促进老年性痴呆的发生,银杏内酯B对损伤神经元在一定程度上有保护作用。     

银杏内酯B对载脂蛋白E基因敲除小鼠动脉粥样硬化的影响

目的评价银杏内酯B对载脂蛋白E基因敲除(ApoE-/-)小鼠动脉粥样硬化的影响。方法选用8周龄雄性ApoE-/-小鼠,给予高脂饮食喂养。将动物分为模型组、银杏内酯B(GB)组和阿司匹林(ASA)组。8周后处死小鼠,进行血脂测定和血浆炎症蛋白ELISA测定,免疫组织化学法分析主动脉斑块。用健康人血小板分析血小板聚集,使用检测血小板聚集仪检测血小板聚集。Western Blotting法分析Akt磷酸化。结果银杏内酯B组小鼠血浆趋化因子RANTES水平下降了47%,阿司匹林组下降了69%,与模型组比较差异有显著性。与模型组比较,血小板第4因子(PF4)水平银杏内酯B组下降了45%(P<0.05),阿司匹林组下降了11%(P>0.05)。主动脉油红O染色显示与模型组比,银杏内酯B组脂质沉积减少40%,阿司匹林组减少31%,差异有统计学意义。巨噬细胞染色表明银杏内酯B组和阿司匹林组主动脉斑块处巨噬细胞浸润比模型组分别减少51%和11%,差异均有统计学意义。斑块局部炎症蛋白分析表明,与模型组比较,血管细胞黏附分子1(VCAM-1)表达在银杏内酯B组减少69%,阿司匹林组减少32%,差异有统计学意义。银杏内酯B组RANT...     

血管活性肠肽对神经细胞脂褐素影响的实验研究

采用小鼠神经母细胞癌细胞无血清培养建立神经细胞老化实验研究模型。以显微荧光分光光度术测定的细胞内脂褐素自发荧光值为神经细胞老化指标，观察血管活性肠肽（ＶＩＰ）对实验性神经细胞内脂褐素荧光值的影响。结果发现：ＶＩＰ作用５ｄ可显著升高细胞内的脂褐素荧光值（Ｐ＜０．０１）．提示ＶＩＰ可加速实验性神经细胞的老化过程。     

香烟对气道上皮细胞表达4-羟基壬烯醛的影响以及银杏内酯B的干预作用

目的探讨香烟烟雾浓缩物(CSC)对人类支气管上皮细胞系(16-HBE)表达4-羟基壬烯醛(4-HNE)的影响以及银杏内酯 B 的干预作用;并观察4-HNE 对中性粒细胞的趋化作用。方法采用免疫细胞化学和 Western blot 方法。(1)不同浓度(1、10μg/ml CSC)CSC 刺激16-HBE 细胞4h后4-HNE 加成蛋白的表达水平,设正常对照组(无血清培养基代替 CSC);(2)10μg/ml CSC 刺激不同时间(1、4、8、12、24、30h)后,16-HBE 中4-HNE 加成蛋白的水平,设正常对照组(无血清培养基代替 CSC);(3)用100μmol/L 银杏内酯 B 孵育16-HBE 后,CSC 刺激1、4、8、12h,检测4-HNE 加成蛋白表达的变化,设正常对照组(无银杏内酯 B 孵育);(4)以趋化实验检测0.1、1、10μmol/L 4-HNE 对兔中性粒细胞的趋化作用。结果(1)1、10μg/ml CSC 刺激4h 后,16-HBE 细胞表达4-HNE 加成蛋白水平(免疫化学为2.12±0.38、2.69±0.42,Western blot 为100.2±6.3、72.3±6.1)均较正常对照组显著增加(免疫化学为1.25±0.37,Western blot 为122.4±4.2,P 均<0.01)。(2)10μg/ml CSC 刺激1、4、8、12、24、30h后,16-HBE 细胞表达4-HNE 加成蛋白(免疫化学为2.67±0.46、2.69±0.42、2.71±0.48、2.72±0.56、2.93±0.11、2.92±0.20,Western blot 为73.2±8.3,72.3±6.4,72.6±9.2,71.5±8.1,54.4±3.6,56.7±4.4)较正常对照组(免疫化学为1.25±0.35,Western blot 为122.4±4.1)显著增加(P 均<0.01),刺激24h 和30h,细胞内4-HNE 加成蛋白较其他时间点增加。(3)50、100μmol/L 银杏内酯 B 孵育后再以 CSC 刺激时,16-HBE 细胞内4-HNE 加成蛋白表达水平(Westernblot 为84.6±4.4、101.2±4.4)明显低于未以内酯 B 孵育组,但高于正常对照组(Western blot 为72.5±6.4,P 均<0.01)。(4)0.1、1、10μmol/L 4-HNE 对兔中性粒细胞趋化数目(92±12、104±16、131±12)较正常对照组(72±12)均显著增加,10 μmol/L 4-HNE 趋化数目显著高于0.1和1μmol/L4-HNE,差异均有统计学意义(P 均<0.01)。结论香烟所引起肺中性粒细胞趋化的结果可能与其促使4-HNE 产生增加有关,银杏内酯 B 可以抑制 CSC 对4-HNE 的诱生。     

多巴胺对体外培养神经细胞的影响

目的　研究高浓度多巴胺 (DA)对神经细胞的毒性作用。　方法　观察不同浓度、不同时间DA对体外培养神经细胞的毒性 ,并用琼脂糖凝胶电泳、原位末端标记、流式细胞仪进行细胞凋亡的检测。　结果　 (1)高浓度DA引起神经细胞凋亡 ;(2 )给予 80、16 0、32 0 μmol/LDA处理 2 4h后神经细胞凋亡率分别为 (41 49± 1 32 ) %、(6 5 6 7± 1 6 8) %、(84 6 5± 2 2 1) % ,明显高于浓度效应对照组〔(2 0 7± 0 2 6 ) % ,P <0 0 5〕 ;(3)在给予 30 0 μmol/LDA处理的条件下 ,经过 12、2 4、48h后 ,神经细胞的凋亡率分别为 (37 90± 0 39) %、(6 9 34± 3 31) %、(82 0 7± 0 86 ) % ,明显高于时间效应对照组〔(2 30± 0 11) % ,P <0 0 5〕。　结论　高浓度DA对体外培养神经细胞具有细胞毒性 ,诱导神经细胞凋亡 ,具有时间及剂量效应。     

Transcellular transport characteristics of huperzine alone or in combination with ginkgolide B across Caco-2 and Madin-Darby canine kidney cell monolayer

Objective:To study the various processes involved in transcellular transport(TT) of huperzine A alone or in combination with ginkgolide B in Caco-2 and Madin-Darby canine renal(MDCK)cell monolayer.Methods:The transepithelial passage was assayed in the apical-to-basolateral(AP to BL) direction and opposite direction(BL to AP) in both cell lines.The determination of huperzine A and ginkgolide B were performed by high performance liquid chromatography(HPLC).The passage rates of huperzine A and ginkgolide B were calculated.Bi-directional TT(absorption and secretion) were taken in huperzine A and ginkgolide B in Caco-2 and MDCK cell monolayer.Results:TT absorption and secretion kinetics of huperzine A and ginkgolide B across two cells existed at the same time.The passage rates of huperzine A were increased significantly with adding different concentrations of ginkgolide B.Conclusions:The compound preparations of HA in combination with CB for dementia caused by cerebral ischemic have synergistic effects on the pharmacodynamics,and improve the bioavailability through BBB.     

Elevated serum homocysteine as a predictor for vitamin B12 or folate deficiency

Abstract: Tissue deficiency of vitamin B₁₂ and folate results in an increase in serum homocysteine (sHcy). We have measured sHcy in patients with reduced serum vitamin B₁₂ and/or red cell folate (RCF) to determine its usefulness as a discriminant for the diagnostic interpretation of reduced vitamin levels. Of 3846 patients who had serum vitamin B₁₂ and RCF assayed, 335 (9%) had reduced vitamin levels. Multivariate analysis showed a significant association between sHcy and serum creatinine (p = 0.0001), positive intrinsic factor (IF) antibody or neutrophil hypersegmentation (NHS) (p = 0.001), increased MCV (p = 0.014) and low RCF (p = 0.025) but no relationship with the level of serum vitamin B₁₂ or haemoglobin. After censoring the patients with renal impairment (n = 54), the distribution of the remaining 72 patients with elevated sHcy was 37/151 (25%) with low serum vitamin B₁₂ with or without low RCF and 35/130 (27%) with low RCF alone. sHcy correctly identified response to vitamin therapy in 33/35 (94%) patients who had adequate parameters to assess response. The positive predictive values of IF antibody/NHS, macrocytosis and/or low RCF for elevated sHcy were 100% and 34% respectively. Twenty-four percent of patients with a low serum vitamin B₁₂ and elevated sHcy had no abnormal haematologic parameters as determined by the routine laboratory staff. These data suggest that the usefulness of measuring sHcy in a routine diagnostic setting is limited and a careful review of the peripheral blood for macrocytosis and NHS plus determination of RCF may be a more cost-effective process than sHcy assay in most instances to determine the presence of tissue deficiency.     

Food-bound B12 absorption and serum total homocysteine in patients with low serum B12 levels

This study was undertaken to determine whether measurements of serum total homocysteine (Hcys) and bound B12 absorption are useful in determining which patients with low- or low-normal levels of serum B12 are B12 deficient. In 40 patients with low or borderline serum levels of B12, food-bound B12 absorptions were determined using a body counter in an iron room, and were related to serum total Hcys levels. Food-bound B12 absorption was decreased in 16 patients and in an additional four, absorption of the free vitamin was also decreased. Homocysteine levels were elevated in four of the 16; in three of the four who had both decreased bound and free B12 absorptions, Hcys was elevated. If elevation of the Hcys level indicates tissue deficiency of B12, the 75% incidence of normal levels of Hcys in these patients with low food-bound B12 absorptions suggests the existence of a cohort of patients who may be at risk to develop, but have not yet developed, B12 deficiency. Only long term follow-up will reveal how many ultimately will become B12 deficient. Am. J. Hematol. 59:42–45, 1998. © 1998 Wiley-Liss, Inc.     

高碘对小鼠大脑神经细胞超微结构的影响

目的 研究高碘对小鼠大脑海马组织形态和神经细胞超微结构的影响。方法 用随机区组法将动物随机分为高碘、低碘、适碘三组,复制高碘、低碘甲状腺肿动物模型,观察其仔一代鼠１５日龄时的大脑海马组织形态和神经细胞超微结构。结果 高碘组大脑海马神经细胞核浓缩、胞浆增多,特别是核周的细胞质减少消失,出现了“空晕”现象。超微结构显示,高碘组神经细胞核肿胀变性,异染色质明显减少,结构松懈,部分区域丢失,胞质内线粒体肿     

实验性肝硬化大鼠纹状体中神经元的形态定量学研究

目的 观察肝硬化大鼠纹状体中神经元的形态及数目的变化，探讨肝性脑病的发病机制。方法 用四氯化碳（CCL4）建立肝硬化模型，尼氏染色法观察纹状体神经元的变化。图像分析仪对神经元的形态及数量变化做定量分析。结果 肝硬化模型制备成功。肝硬化大鼠纹状体中神经元数量减少，染色变浅，尼氏小体减少或消失。结论 提示纹状体神经元的变化有可能与肝性脑病时出现的运动异常有关。     

Mechanism and dose-effect of Ginkgolide B on severe acute pancreatitis of rats

AIM:To determine the optimal dosage and mechanism of Ginkgolide B(BN52021) on severe acute pancreatitis(SAP) of rats.METHODS:Seventy male Wistar rats were randomly divided into seven groups(10 for each group).Shamoperation group(SO),SAP model group(SAP),dimethyl sulfoxide(DMSO) contrast group(DMSO),and groups treated with 2.5 mg/kg BN52021(BN1),5 mg/kg BN52021(BN2),10 mg/kg BN52021(BN3),and 20 μg/kg Sandostatin(SS).The SAP model was established in Wistar rats by injecting 5% sodium taurocholate retrogradely...     

Platelet Activating Factor (PAF) Antagonism with Ginkgolide B Protects the Liver Against Acute Injury. Importance of Controlling the Receptor of PAF

Platelet activating factor (PAF) is an ubiquitous phospholipid that acts as a mediator of numerous pathophysiological conditions, including hepatotoxicity. The present study has been conducted to evaluate the eventual role of the platelet activating factor in post-acetaminophen intoxication of liver, using ginkgolide B, BN52021, a selective PAF receptor antagonist. One group of rats was treated with a toxic dose of acetaminophen (APAP) (3.5 g/kg b.w.) (control group) and a second one with the same dose of APAP followed by a dose of ginkgolide B, BN52021 (10 mg/kg b.w.) (BN52021-treated group). The animals were killed at 8, 16, 24, 32 and 40 h after treatment. APAP was found to cause an acute hepatic injury, evident by alterations of biochemical (serum enzymes: ALT, AST and ALP) and liver histopathological (degree of inflammation and apoptosis) indices, which was followed by liver regeneration evident by three independent indices ([3H] thymidine incorporation into hepatic DNA, liver thymidine kinase activity and hepatocyte mitotic index). Hepatic levels of malondialdehyde and serum cholesterol/HDL cholesterol fraction were also measured as parameters of oxidant–antioxidant balance. The protected effects of ginkgolide B were qualified during post treatment time by: (1) reduction of oxidative stress, (2) high decrease of hepatic injury, and (3) decrease of regenerating activity. These results indicate that PAF may play an important role in APAP-induced liver injury and regeneration, and that the use of ginkgolide B attenuates liver damage providing important means of improving liver function following acetaminophen intoxication.