大黄醇提液抗家兔实验性高脂血症及脂肪肝的实验研究

目的:检验大黄醇提液抗家兔实验性高脂血症及脂肪肝的影响。方法:将30只雄性健康白兔随机分为5组(n=6):对照组给予基础饲料;模型组给予高脂饲料;三个大黄组给予高脂饲料同时分别灌胃不同药量的大黄醇提液。实验过程中进行一般性指标观测,检测不同阶段五组家兔血脂水平,检测脂肪肝病变程度。结果:大黄醇提液具有降低血清甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C),升高高密度脂蛋白胆固醇(HDL-C),降低肝细胞脂肪变性的作用。并且大黄醇提液的以上作用存在一定的量效关系。结论:大黄醇提液可降低动脉粥样硬化兔模型的血脂水平、降低脂肪肝的发生发展。     

河北省小五台山自然保护区蚜蝇科昆虫的调查(双翅目)

通过对河北省小五台山自然保护区蚜蝇科昆虫的调查,结合整理河北大学博物馆馆藏蚜蝇科昆虫标本,鉴定出小五台山自然保护区蚜蝇科昆虫54种,包括10新种,3中国新记录种,隶属于2亚科、9族、27属。文中给出种类名录及新种、新记录种描述和特征图。新种正模标本保存于河北大学博物馆,副模标本保存于陕西理工学院陕西省资源生物重点实验室。     

我国湖泊表层沉积物生物硅的空间分布特征

选取我国东北、西南、西北及中北部地区的10个典型湖泊,调查了表层沉积物生物硅含量变化情况,并通过区域对比分析了生物硅含量变化的原因,寻找我国湖泊生物硅变化的空间规律。结果表明,西北及中北部地区湖泊生物硅含量平均值整体低于东北和西南地区湖泊,可能是由于西北及中北部地区较低的温度和较少的降水量导致硅藻生长受限,从而造成生物硅含量偏低。东北湖泊与西南湖泊生物硅含量相对较高,但其形成原因不同。东北2个湖泊均靠近人类聚居区,属富营养型湖泊,虽然东北地区年均温较低,但充足的营养盐为硅藻生长提供了必要因素。而西南地区湖泊大多为中贫营养型湖泊,其生物硅含量整体较高可能主要归因于较高的温度和较多的降水。     

Dynamics of Membrane Tethers Reveal Novel Aspects of Cytoskeleton-Membrane Interactions in Axons

Mechanical properties of cell membranes are known to be significantly influenced by the underlying cortical cytoskeleton. The technique of pulling membrane tethers from cells is one of the most effective ways of studying the membrane mechanics and the membrane-cortex interaction. In this article, we show that axon membranes make an interesting system to explore as they exhibit both free membrane-like behavior where the tether-membrane junction is movable on the surface of the axons (unlike many other cell membranes) as well as cell-like behavior where there are transient and spontaneous eruptions in the tether force that vanish when F-actin is depolymerized. We analyze the passive and spontaneous responses of axonal membrane tethers and propose theoretical models to explain the observed behavior.     

Mutational approach for N2-fixing and P-solubilizing mutant strains of Klebsiella pneumoniae RSN19 by microwave mutagenesis

Nitrogen (N) fixing Klebsiella pneumoniae RSN19 has high inorganic phosphorus (P) solubilizing capability, but its N₂-fixing capability is limited. In order to acquire a P-solubilizing mutant strain with high efficiency N-fixing capability, different microwave irradiation intensities and durations were tested on RSN19 in an attempt to produce mutants with improved N₂-fixation and P-solubilization capabilities. The effect of microwave irradiation power and time were studied and the microwave mutagenesis parameters were optimized. Nitrogenase activity was tested on the mutant strains by acetylene reduction method; and their P-solubilizing capability and genetic stability were determined. The results indicated that the best conditions for microwave mutagenesis that produced better performed mutant strains were 250W, 36 s. Under these conditions a maximum positive mutation rate of 1.66% was obtained, resulting in five genetically stable strains with promoted nitrogenase activity which was designated as RSM-219, RSM-206, RSM-224, RSM-225 and RSM-275. Subculture tests showed that RSM-219 and RSM-206 were genetically stable mutant strains with higher nitrogenase activity and phosphate solubilizing capabilities than the original strain. Both RSM-219 and RSM-206 performed better than the original strain under N-free conditions when supplied with calcium phosphate only, and produced greater increases in the biomass of alfalfa seedlings.     

Stable and orally bio-available pro-drugs of CPS11

Stable and orally bio-available pro-drugs of CPS11 were synthesized. They are active on human umbilical vein endothelial cell proliferation assay and tube formation assay. The therapeutic efficacy and safety of 4 as a single agent or combined with Taxol in the treatment of MX-1 human breast cancer xenograft were evaluated. Compound 4 as a single agent failed to produce an anti-tumor activity, while it significantly enhanced antitumor potency of Taxol.     

氨溴索与肝素联合应用对急性肺损伤兔TNF-α和IL-1β的影响

目的：探讨联合应用氨溴索与小剂量肝素对急性肺损伤（ALI）时氧化应激,TNF-α和IL-1β变化的干预及其机制。方法：健康日本大耳白兔24只,随机分成3组（n=8）：①生理盐水对照组（NC）,②油酸损伤组（OA）,③氨溴索＋小剂量肝素治疗组（AH）。各组分别在给药前和给药后6 h采血及测定动脉血氧分压（PaO2）、肿瘤坏死因子-α（TNF-α）、白介素-1β（IL-1β）的含量,实验结束后肉眼观察肺病理改变,测定支气管肺泡灌洗液（BALF）以及肺组织匀浆中TNF-α、IL-1β、超氧化物歧化酶（SOD）、丙二醛（MDA）、黄嘌呤氧化酶（XO）、谷胱甘肽过氧化物酶（GSH-Px）的含量,检测肺组织原位凋亡细胞变化、肺组织湿干比（W/D）,光镜观察肺组织病理改变,电镜观察肺组织超微结构变化。结果：①光镜,电镜观察结果以及W/D提示氨溴索＋小剂量联合治疗减轻了ALI造成的肺组织形态学改变。②OA组中显著降低的PaO2均在AH组明显升高（P〈0.01）。③抗氧化指标GSH-Px和SOD活力检测,发现AH组比OA组有不同程度升高（P〈0.01或P〈0.05）,而氧化性指标XO活力和MDA含量则较OA组显著降低（P〈0.01）。④除给药前IL-1β外,在OA组中IL-1β、TNF-α含量均显著高于NC组（P均〈0.01）,但在AH组中有显著的降低（P〈0.01）。⑤AH组凋亡指数（AI）比OA组显著降低（P〈0.01）。结论：在OA致ALI时,TNF-α和IL-1β明显升高,参与了ALI的发生与发展。联合应用氨溴索与小剂量肝素可减轻氧化应激反应,抑制促炎细胞因子TNF-α和IL-1β释放,发挥对ALI的治疗作用。     

微滴培养技术的新应用

微滴培养技术在卵母细胞培养和胚胎早期发育研究中有广泛的应用.近期研究发现这项技术又有新的应用范围.有科学家发现将该技术应用于胚胎干细胞可以实现高效传代,在精原干细胞培养和精子发生相关过程的研究方面也可取得很好效果,同时,对早期人类胚胎干细胞的分离过程的监控和对精原干细胞生长过程的观察也相对容易.这些研究结果显示,微滴培养技术在这些新领域的研究与常规培养方法相比具有独特的优势.回顾微滴培养技术的主要发展过程,重点探讨微滴培养技术的最新应用及其优点.