鱼油对高脂喂养加小剂量STZ诱导的2型糖尿病大鼠血脂及肝脏的影响

目的:探讨鱼油对高脂喂养加小剂量STZ诱导的2型糖尿病大鼠脂代谢及肝脏组织的影响及其机制。方法:Sprague-Dawley大鼠随机分为对照组(Control)、高脂组(HF)、糖尿病组(DM)、高脂鱼油组(HF+FO)和糖尿病鱼油组(DM+FO),观察大鼠周体重变化,检测各组大鼠血糖、血脂、肝脏细胞形态学及过氧化损伤情况,探讨其可能的作用机制。结果:与对照组相比,高脂喂养大鼠体重明显增加(387.74±36.20 g vs 339.64±10.41 g,P0.05),血甘油三酯(triglyceride,TG)、总胆固醇(total cholesterol,TC)和低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)分别由1.96±0.06 mmol/L、1.91±0.09 mmol/L和0.72±0.07 mmol/L升高至2.29±0.16 mmol/L、2.08±0.06 mmol/L和1.22±0.09 mmol/L,高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)降低(0.92±0.15 mmol/L vs 1.80±0.07 mmol/L,P0.05),膳食添加鱼油后均有明显改善。糖尿病大鼠体重减轻(287.78±16.11 g vs 339.64±10.41 g,P0.05);但血清中LDL-C水平升高至1.08±0.08 mmol/L,HDL-C水平降低至1.09±0.07 mmol/L(P0.05),鱼油可显著提高HDL-C的水平(P0.05)。高脂组和糖尿病组均有明显的肝脏脂肪浸润和过氧化损伤,添加鱼油后明显减轻。结论:膳食添加鱼油对高脂膳食及2型糖尿病引起的血脂异常均有保护作用,可降低血中甘油三酯和低密度脂蛋白胆固醇水平;减轻大鼠肝脏脂肪浸润和过氧化损伤。     

糖尿病大鼠下丘脑Nesfatin-1对胃运动的影响及机制研究

目的:探讨下丘脑腹内侧核Nesfatin-1对正常大鼠及糖尿病大鼠胃运动的影响及其潜在机制。方法:正常大鼠随机分为0.08μg,0.8μg,8.0μg/0.5μL Nesfatin-1组;30μg/0.5μL astressin-B组;(0.8μg Nesfatin-1+30μg astressin-B)/0.5μL组;0.5μL生理盐水(NS)组;正常羊血清+假刺激(NR+SS)组;正常羊血清+电刺激(NR+ES)组;抗NUCB2/Nesfatin-1抗体+假刺激(anti-Nn-Ab+SS)组;抗NUCB2/Nesfatin-1抗体+电刺激(anti-Nn-Ab+ES)组。制作糖尿病大鼠模型,将糖尿病大鼠随机分为0.08μg/0.5μL Nesfatin-1组;0.8μg/0.5μLNesfatin-1组;8.0μg/0.5μL Nesfatin-1组;0.5μLNS组;NR+SS组;NR+ES组;anti-Nn-Ab+SS组;anti-Nn-Ab+ES组。大鼠胃部置入感应器后腹内侧核置管,记录清醒大鼠胃运动及电刺激海马CA1区后的胃运动。结果:与生理盐水组相比,下丘脑腹内侧核注射不同浓度Nesfatin-1,大鼠胃收缩幅度和频率显著降低,下丘脑腹内侧核注射0.5μL(0.8μg Nesfatin-1+30μg astressin-B)混合液后,相比单独给予0.8μg Nesfatin-1组,大鼠胃收缩幅度和频率显著升高。大鼠下丘脑腹内侧核注射0.5μL Nesfatin-1(0.8μg),大鼠胃收缩幅度和频率显著降低,下丘脑腹内侧核注射0.5μL(0.8μg Nesfatin-1+30μg astressin-B)混合液后,相比单独给予0.8μg Nesfatin-1组,大鼠胃收缩幅度和频率显著升高。下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与正常羊血清+电刺激组相比,大鼠胃收缩幅度和频率进一步增强,下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与单独注射抗NUCB2/Nesfatin-1抗体+假电刺激组相比,大鼠的胃收缩幅度和频率显著增高。下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再给予电刺激海马CA1区,与正常羊血清+电刺激组相比,正常大鼠和糖尿病大鼠胃运动指数均显著增加,下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再电刺激海马CA1区,与单独注射抗NUCB2/Nesfatin-1抗体+假电刺激组相比,正常和糖尿病大鼠的胃运动指数均显著增高。与正常大鼠相比,电刺激海马CA1区、下丘脑腹内侧核注射抗NUCB2/Nesfatin-1抗体后再给予电刺激海马CA1区,或下丘脑腹内侧核微量注射抗NUCB2/Nesfatin-1抗体,糖尿病大鼠胃运动指数均无显著差异。结论:海马-下丘脑Nesfatin-1信号通路参与胃传入信息和胃运动调控,该作用可能与CRF系统活动有关。     

姜黄素对糖尿病大鼠大脑海马神经元的作用研究

目的观察姜黄素(Curcumin,Cur)对STZ诱导的2型糖尿病大鼠大脑海马神经元的影响。方法雄性SD大鼠随机分为3组:正常对照组(Con组),高糖高脂饮食结合链脲佐菌素(STZ)诱导的2型糖尿病模型组(DM组)和给予姜黄素处理的糖尿病组(DM+Cur组)。免疫印迹法(WB法)检测大鼠大脑海马凋亡相关蛋白Bcl-2和Bax的蛋白含量;免疫组织化学法(IHC法)检测凋亡执行者caspase-3在大鼠大脑海马各区中的表达情况。结果大鼠给予高糖高脂饮食一个月后,腹腔注射STZ可诱导大鼠血糖升高,继续给予高糖高脂饮食,大鼠出现类似于2型糖尿病的症状,通过WB检测,DM组大鼠海马的Bcl-2/Bax比值较Con组明显下降(P0.05),而给予姜黄素处理16周后的DM+Cur组大鼠可明显增强抗凋亡蛋白Bcl-2的表达而减弱促凋亡蛋白Bax的表达,两者比值增大(P0.05);另外,通过IHC法检测发现,DM组大鼠海马各区的caspase-3阳性表达明显增多,而DM+Cur组可减弱caspase-3的阳性表达。结论高糖高脂饮食结合STZ腹腔注射可诱导出2型糖尿病大鼠模型,姜黄素能通过调控DM大鼠海马凋亡相关蛋白的表达而发挥保护作用。     

线粒体大麻素受体1在大鼠海马神经元缺氧复氧损伤中对线粒体分裂的影响

目的:探讨线粒体CB1受体(mitochondrial cannabinoid receptor1,mtCB1)在大鼠海马神经元缺氧复氧损伤中对线粒体分裂的影响。方法:原代培养新生的Wistar大鼠海马神经元,将培养至第8天的海马神经元采用随机数字表分为5组(n=60):正常组(N组):正常培养,不做任何处理;缺氧复氧组(H/R组):采用氧糖剥夺法构建海马神经元缺氧复氧损伤模型,缺氧6h,复氧20 h;缺氧复氧组+ACEA+AM251组(H/R+ACEA+AM251组):缺氧6 h结束后立即加入ACEA和AM251,终浓度分别为1μmol/L、10μmol/L,复氧20 h;缺氧复氧+ACEA+Hemopressin(H/R+ACEA+Hemo组):缺氧6h结束后立即加入ACEA和Hemopressin,终浓度分别为1μmol/L、10μmol/L,复氧20 h;缺氧复氧+赋形剂组(H/R+V组):同样于缺氧6h结束后立即加入二甲基亚砜(DMSO),终浓度0.1%,复氧20 h。使用激光共聚焦显微镜检测细胞内Ca~(2+)的浓度,流式细胞仪检测细胞凋亡率,Western blot检测凋亡诱导因子(AIF)、线粒体分裂相关蛋白Drp1、Fis1,细胞凋亡相关蛋白细胞色素C(Cytc)和Rho相关的卷曲蛋白激酶1(ROCK1)的表达。结果:与N组相比,H/R组、H/R+ACEA+AM251组、H/R+ACEA+Hemo组和H/R+V组的细胞内Ca~(2+)浓度、细胞凋亡率、以及AIF、Drp1、Fis1、Cytc、ROCK1蛋白的表达水平均明显增加(P0.05);与H/R组相比,H/R+ACEA+Hem组上述各检测指标明显降低(P0.05),H/R+ACEA+AM251组和H/R+V组各指标比较差异无统计学意义(P0.05)。结论:线粒体CB1受体(mtCB1受体)可能通过降低细胞内ROS的含量来减少细胞内Ca~(2+)浓度和ROCK1的表达,进而抑制线粒体分裂,并最终减轻海马神经元缺氧复氧损伤。     

负载维生素D3的海藻酸纳米粒抗佝偻病作用研究

目的:观察负载维生素D3海藻酸纳米粒和维生素D3的抗佝偻病作用.方法:36只SD大鼠随机分组为正常对照组、佝偻痛模型组、负载VD3的自组装海藻酸钠纳米粒(sSAN-VD3)低剂量组(1.70 mg·kg-1·d-1含VD315.0μg)、sSAN-VD3高剂量组(4.2 mg·kg-1·d-1含VD337.5μg)、VD3低剂量组(15.0μg·kg-1·d-1)、VD3高剂量组(37.5μg·kg-1·d-1)6组,每组6只.正常对照组大鼠在通光条件下用正常饲料饲养,其余各组大鼠置于暗室中,并喂养缺乏维生素D3的饲料,同时各预防给药组按剂量连续灌胃给药35天.观察记录大鼠的体重变化,检测大鼠血清中25羟基维生素D3(25-(OH)VD3)、血清骨碱性磷酸酶(Bone Alkaline Phosphatase,BAP)活性及股骨骨密度(Bone Mineral Density BMD).结果佝偻病模型组大鼠喂养5周后体重明显低于正常对照组,血清BAP活性明显增高,血清25-(OH)VD3含量及股骨BMD则显著降低(P<0.05);与佝偻病模型组大鼠比较,各预防给药组大鼠体重及股骨BMD均有所增加,sSAN-VD3高、低剂量组和VD3高剂量组大鼠血清BAP活性降低,25-(OH)VD3水平明显升高,与模型组差异显著(P<0.05);与同剂量的VD3低剂量组比较,sSAN-VD3低剂量组大鼠的血清BAP、25-(OH)VD3及股骨BMD等三项指标均显示出更明显的抗佝偻痛作用(P<0.05).结论:负载维生素D3海藻酸纳米粒和维生素D3均具有良好的抗佝偻病作用,以前者作用较强.     

戊四氮致痫大鼠大脑皮质和海马内GFAP和cyclin D1表达的变化及脑和脑脊液天冬氨酸和谷氨酸含量的变化

目的研究癫痫发病时星形胶质细胞的激活及脑和脑脊液兴奋性氨基酸含量的变化.方法将实验SD大鼠随机分为2组:1.生理盐水对照(control)组(n=8);腹腔注射与致痫剂等容量的生理盐水.2.戊四氮(PTZ)组;PTZ 60mg/kg腹腔注射后2h、4h、8h、12h取脑,每个时间点各8只,检测下列指标:(1)用免疫组织化学方法(SABC法)观察大鼠大脑皮质和海马内星形胶质细胞胶质原纤维酸性蛋白(GFAP)含量的变化;(2)用Western blot方法检测大鼠大脑皮质和海马细胞周期素D1(cyclin D1)表达的变化;(3)采用高效液相色谱(HPLC)法测定大鼠大脑皮质和海马组织匀浆及脑脊液中兴奋性氨基酸(天冬氨酸和谷氨酸)含量的变化.结果星形胶质细胞GFAP免疫组织化学染色结果显示癫痫发作4h后在大脑皮质和海马CA3区、CA1区和皮质内GFAP免疫反应明显增强(P<0.05);Western blot检测癫痫发作2h后cyclin D1的表达在皮质和海马均较对照组明显增强(P<0.05);HPLC测定癫痫发作4h后大脑皮质中天冬氨酸(Asp)和谷氨酸(Glu)的含量达到最高峰,分别为8.900±0.540μmol/g protein和17.500±0.526μmol/g protein,与对照组(分别为7.083±0.693μmol/g protein和7.017±0.419μmol/g protein)相比均有显著性差异(P<0.05),在海马内Asp的含量在癫痫发作后2h达到最高峰,为11.425±1.006μmol/g protein,Glu的含量在癫痫发作后4h达到最高峰,为17.698±0.250μmol/g protein,与对照组(分别为7.300±0.824μmol/g protein和10.925±0.323μmol/g protein)比较均有显著性差异(P<0.05),脑脊液中Asp的含量在癫痫发作后2h达到最高峰,为82.65±4.81μmol/L,而Glu的含量在癫痫发作后持续增高,12h后达到72.80±3.66μmol/L.结论戊四氮致痫过程中兴奋性氨基酸含量增多,海马及皮质内星形胶质细胞激活,cyclin D1表达增加,星形胶质细胞增殖,以上变化在癫痫的形成和维持中发挥作用.     

ERK激活对SDF-1引起的大鼠海马神经元GABA分泌抑制的影响

目的:观察细胞外调节激酶(ERK)信号通路激活对基质细胞衍生因子(SDF-1)引起离体培养的大鼠海马神经元γ-氨基丁酸(GABA)分泌的影响。方法:新生SD大鼠海马神经元离体培养,Western blot法观察ERK1/2信号通路的磷酸化水平;ELISA法和RT-PCR技术检测ERK1/2特异性阻断剂PD98059作用于离体培养的海马神经元后GABA分泌的改变;谷氨酸脱羧酶(GAD65/67)和γ-氨基丁酸转运体(GAT)的蛋白表达量及GAD65和GAT-1 mRNA表达水平。结果:SDF-1作用于海马神经元可引起ERK1/2磷酸化水平明显升高,同时加用CXCR4受体阻断剂AMD3100,可阻断SDF1引起的ERK1/2激活;SDF-1可明显抑制离体培养的海马神经元GABA的分泌,同时加用ERK1/2特异性抑制剂PD98059,可部分逆转SDF-1对GABA分泌的抑制作用;SDF-1作用于离体培养的海马神经元,可抑制谷氨酸脱羧酶GAD65和GABA转运体GAT-1 mRNA的生成;ERK抑制剂PD98059可有效翻转SDF-1的作用。Western blot结果发现SDF-1可抑制海马神经元GAT-1和GAD65/67蛋白的表达,加用ERK1/2抑制剂可部分恢复GAT-1和GAD65/67蛋白合成。结论:SDF1作用于离体培养的海马神经元CXCR4,通过激活ERK1/2信号通路进而抑制GAD蛋白表达,可能是其介导GABA分泌抑制的通路之一。     

硫化氢减轻同型半胱氨酸诱导大鼠海马CA1区神经元损伤

目的探讨硫化氢(H2S)对同型半胱氨酸(Hcy)诱导大鼠海马CA1区神经元损伤的改善作用。方法以侧脑室注射同型半胱氨酸的SD大鼠为同型半胱氨酸神经毒性动物模型,采用Tunel染色法分析大鼠海马CA1区神经元的凋亡情况,采用Elisa法分析大鼠海马组织MDA含量。结果 0.6μmol和2.0μmol的同型半胱氨酸使大鼠海马CA1区神经元发生大量的凋亡(P0.01),而NaHS(100μmol/kg)显著抑制同型半胱氨酸(0.6μmol)诱导大鼠海马CA1区神经元的凋亡(P0.05);同型半胱氨酸(0.2,0.6μmol)可增加大鼠海马CA1区丙二醛含量(P0.001),而NaHS(100μmol/kg)可抑制同型半胱氨酸(0.6μmol/L)诱导大鼠海马CA1区丙二醛水平的增加(P0.001)。结论硫化氢可减轻同型半胱氨酸诱导大鼠海马CA1区神经元的损伤。     

组织蛋白酶K对大鼠空间学习记忆功能的影响

目的:探讨组织蛋白酶K(CatK)对大鼠海马空间学习和记忆功能的影响及其神经化学机制。方法:SD雄性大鼠随机分为对照组(Control组)和CatK阻断组(CatKⅡ组)每组各10只,分别于海马DG区微量注射组织蛋白酶K特异性阻断剂(0.5μg/μl)和等量人工脑脊液5 d;原代培养海马神经元细胞,设对照组(CON组)、阴性对照组(NC组)和siRNA干扰组(siCatK组),每组设3个复孔,siRNA导入18～20 h后收集样本。应用Morris水迷宫评估大鼠空间学习和记忆功能,同时在大鼠清醒、自由活动状态下,结合脑部微量透析法和高效液相色谱法观察学习记忆过程中DG区细胞外液中谷氨酸(Glu)含量的动态变化;采用蛋白免疫印迹法检测海马组织和神经元细胞中c-Notch1、Notch1、p-CREB、BDNF等相关信号蛋白的表达情况。结果:动物实验显示,与Control组相比,CatKⅡ组空间学习记忆能力明显减弱,并伴随着海马组织的c-Notch1、p-Akt、p-CREB和BDNF蛋白表达明显下降(P<0.05);Control组和CatK II组DG区Glu含量均随水迷宫训练天...     

CaSR表达在大鼠糖尿病性肝硬化损伤和纤维化发生中的作用

目的:观察钙敏感受体(CaSR)在糖尿病性肝损伤发生中的作用。方法:本实验分别制备糖尿病大鼠和高糖处理HSC系大鼠肝星形细胞模型。40只Wistar大鼠随机分为正常对照组(Control,n=10),糖尿病组(T1D,STZ 60 mg/kg一次性腹腔注射,n=30),造模成功后分别在2、4、8周检测大鼠的体重、血糖、血清中谷草转氨酶(AST)和谷丙转氨酶(ALT)活性,观察形态学和超微结构改变,以及Western blot检测CaSR和肝纤维化相关指标表达的变化。HSC系大鼠肝星形细胞随机分为正常对照组(Control,10%FBS-DMEM+5.6 mmol/L葡萄糖),高糖组(HG,10%FBS-DMEM+40 mmol/L葡萄糖下培养48h)和CaSR抑制剂组(HG+Calhex₂₃₁,10%FBS-DMEM+40mmol/L葡萄糖+2.5μmol/L CaSR抑制剂(Calhex₂₃₁)下培养48h,每组n=5)。结果:动物模型中,与正常组相比,糖尿病大鼠体重减轻,血糖、AST和ALT显著升高,CaSR和胶原Ⅰ(COⅠ)、胶原Ⅲ(C...     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.