三种杜拉属（Drawida）蚯蚓的酯酶同工酶的初步研究

应用聚丙烯酰胺凝胶电泳的方法，对寡毛纲杜拉属三种蚯蚓进行酯酶同工酶酶谱分析。其结果表明，同属蚯蚓具有几条相似的酶谱区带，而不同种蚯蚓又具有各自独特的酶谱带，种间酶谱区带数目、泳动率及染色强度都有明显区别。雅和杜拉蚓酶谱图和天锡杜拉蚓相似，而与管状杜拉蚓相差较远，表明同属蚯蚓在进化水平上的亲缘关系。     

Stabilization of MyoD by direct binding to p57(Kip2)

Recent data have demonstrated the role of Cdk1- and Cdk2-dependent phosphorylation of MyoD(Ser200) in the regulation of MyoD activity and protein turnover. In the present study, we show that in presence of p57(Kip2), MyoD(Ala200), a MyoD mutant that cannot be phosphorylated by cyclin-Cdk complexes, displayed activity 2-5-fold higher than of MyoD(Ala200) alone in transactivation of muscle-specific genes myosin heavy chain, creatine kinase, and myosin light chain 1. Furthermore, p57(Kip2) increases the levels of MyoD(Ala200) in cotransfected cells. This result implies that p57(Kip2) may regulate MyoD through a process distinct from its function as a cyclin-dependent kinase inhibitors. We report that overexpression of p57(Kip2) increased the half-life of MyoD(Ala200). This increased half-life of MyoD involves a physical interaction between MyoD and p57(Kip2) but not with p16(Ink4a), as shown by cross-immunoprecipitation not only on overexpressed proteins from transfected cells, but also on endogenous MyoD and p57(Kip2) from C2C12 myogenic cells. Mutational and functional analyses of the two proteins show that the NH(2) domain of p57(Kip2) associates with basic region in the basic helix-loop-helix domain of MyoD. Competition/association assays and site-directed mutagenesis of the NH(2) terminus of p57(Kip2) identified the intermediate alpha-helix domain, located between the Cdk and the cyclin binding sites, as essential for MyoD interaction. These data show that the alpha-helix domain of p57(Kip2), which is conserved in the Cip/Kip proteins, is implicated in protein-protein interaction and confers a specific regulatory mechanism, outside of their Cdk-inhibitory activity, by which the p57(Kip2) family members positively act on myogenic differentiation.     

研究报告：CRBGP通过抑制FAK-AKT通路和白介素-6的分泌抑制胶质瘤U251细胞的活性

目的电压门控钠通道(voltage-gated sodium channels,VGSCs)表达于胶质瘤U251细胞,并影响U251细胞的增殖、侵袭和凋亡。富含半胱氨酸的颊腺蛋白(cysteine-rich buccal gland protein,CRBGP)是一种从日本七鳃鳗颊腺中分离出来的VGSCs阻断剂。本文旨在探究CRBGP是否因具有VGSCs阻断功能从而能够抑制U251细胞的活性。方法首先采用MTT法检测了CRBGP对U251细胞增殖的作用,并分别利用莱特-吉姆萨、FITC-phalloidin和Hoechst 33258染色法观察CRBGP处理后U251细胞的形态、细胞骨架和细胞核。细胞外基质蛋白如IV型胶原蛋白、纤连蛋白和层黏连蛋白用于检测CRBGP对U251细胞黏附的影响。此外,本文采用transwell法检测CRBGP处理后U251细胞的迁移和侵袭能力,并通过Western blot方法探讨CRBGP诱导U251细胞凋亡并抑制其运动的内在机理。最后,通过酶联免疫吸附测定法检测CRBGP对U251细胞的抑炎效果。结果 CRBGP通过线粒体依赖途径诱导U251细胞凋亡,...     

中国蓼属萹蓄组植物果实形态的研究

应用解剖镜和电子扫描显微镜对中国产蓼属萹蓄组Polygonum sect.Polygonum 16种1变种及1变型植物的果实形态进行了研究。发现该组5种一年生植物的果实具有两型性,即有长、短两种果实类型。短果类型为卵形,具三棱,包于宿存花被内或与花被近等长,呈黑褐色。在解剖镜下观察到其表面具小点、无光泽,而在电子扫描显微镜下观察到其表面具有散乱分布或排列成行的瘤状颗粒;长果类型为狭卵形,具三棱,长于宿存花被,黄褐色或淡黄绿色,在解剖镜下观察到其表面平滑、有光泽,而在电子扫描显微镜下观察到其表面上部具有散乱分布的瘤状颗粒,中、下部则具不规则洼点、星花状褶皱或浅波纹状。果实具两型性的植物有萹蓄P.aviculare、乌鲁木齐萹蓄P.urumqiense、展枝萹蓄P.patulum、直立萹蓄P.avicularef.erectum和尖果萹蓄P.rigidum。果实微形态可分为两种类型：1.果实表面无瘤状颗粒或疣状突起、有光泽,此类型又可以分为2种亚类型：（1）果实表面平滑、浅波纹状,如岩萹蓄P.cognatum、松叶萹蓄P.acerosum和帚萹蓄P.argyrocoleum;（2）果实表面具浅洼点或洼点,如铁马鞭P.plebeium和针叶萹蓄P.polycnemoides。2.果实表面有瘤状颗粒或疣状突起,无或具微光泽,此类型又可分为4种亚类型：（1）果实表面具疣状突起,如圆叶萹蓄P.intramongolicum.;（2）果实表面具散乱分布的瘤状颗粒,如普通萹蓄P.humifusum和展枝萹蓄的短果;（3）果实表面具有纵行排列的瘤状颗粒,如萹蓄和乌鲁木齐萹蓄的短果;（4）果实表面上部具散乱分布的瘤状颗粒,中、下部具不规则洼点、星花状褶皱或浅波纹状,如萹蓄、展枝萹蓄、直立萹蓄和尖果萹蓄的长果。因此果实两型性和果实微形态特征对蓼属萹蓄组种、变种的鉴定具有较大的分类学价值。基于果实微形态特征以及其他形态特征,确定了新种晖春萹蓄Polygonum huichunense F.Z.Li,Y.T.Hou＆C.Y.Qu,同时恢复褐鞘萹蓄Polygonum aviculareL.var.fusco-ochreatum（Kom.）A.J.Li为原种,即Polygonum fusco-ochreatum Kom.。     

2004—2018年青海省乙型病毒性肝炎流行病学特征分析

目的 了解青海省2004—2018年乙型病毒性肝炎(简称乙肝)流行病学特征,为乙肝防治工作提供科学依据。方法 对青海省15年间乙肝监测数据进行描述性流行病学分析。结果 15年来青海省共报告乙肝患者201931例,年平均报告发病率239.71/10万,总体呈下降趋势。2004—2018年西宁市乙肝报告病例98218例,占48.64%;果洛藏族自治州最低,乙肝报告病例6766例,仅占3.35%。玉树藏族自治州乙肝报告发病率最高332.89/10万,海东市最低133.43/10万,不同地区乙肝报告发病率有统计学意义(χ^2=21997.32,P<0.05)。报告病例主要分布在25~55岁人群中,50~<55岁组发病率最高为454.99/10万,0~<5岁组发病率最低为23.69/10万;男、女性别比为1.57∶1。报告病例职业分布以农、牧民为主,占47.19%。结论 青海省经过多年的计划免疫的实施,乙肝防控效果明显,2009年以后乙肝报告病例呈现平稳状况。     

Food web structure in the high Arctic Canada Basin: evidence from δ13C and δ15N analysis

The food-web structure of the Arctic deep Canada Basin was investigated in summer 2002 using carbon and nitrogen stable isotope tracers. Overall food-web length of the range of organisms sampled occupied four trophic levels, based on 3.8 trophic level enrichment (¹⁵N range: 5.3–17.7). It was, thus, 0.5–1 trophic levels longer than food webs in both Arctic shelf and temperate deep-sea systems. The food sources, pelagic particulate organic matter (POM) (¹³C=–25.8, ¹⁵N=5.3) and ice POM (¹³C=–26.9, ¹⁵N=4.1), were not significantly different. Organisms of all habitats, ice-associated, pelagic and benthic, covered a large range of ¹⁵N values. In general, ice-associated crustaceans (¹⁵N range 4.6–12.4, mean 6.9) and pelagic species (¹⁵N range 5.9–16.5, mean 11.5) were depleted relative to benthic invertebrates (¹⁵N range 4.6–17.7, mean 13.2). The predominantly herbivorous and predatory sympagic and pelagic species constitute a shorter food chain that is based on fresh material produced in the water column. Many benthic invertebrates were deposit feeders, relying on largely refractory material. However, sufficient fresh phytodetritus appeared to arrive at the seafloor to support some benthic suspension and surface deposit feeders on a low trophic level (e.g., crinoids, cumaceans). The enriched signatures of benthic deposit feeders and predators may be a consequence of low primary production in the high Arctic and the subsequent high degree of reworking of organic material.     

The kinase inhibitor iso-H7 stimulates rat satellite cell differentiation through a non-protein kinase C pathway by increasing myogenin expression level

We analysed the signaling pathways involved in myogenic differentiation of primary cultures of rat satellite cells using substances targeting the protein kinase C (PKC) and the cAMP protein kinase (PKA) pathways. We have previously shown that iso-H7, which putatively inhibits both PKC and PKA, strongly stimulates satellite cell differentiation, as well as the PKA inhibitor HA 1004. In the study reported here, the effects of iso-H7 on satellite cell differentation were compared to those observed in the presence of agents which reduce PKC activity. It was shown that treatments with the highly specific PKC inhibitor GF109203X or with 12-O-tetradecanoylphorbol 13-acetate (TPA) which induced a partial PKC downregulation, did not significantly alter myogenic differentiation. Northern blot analyses showed that iso-H7 activated the expression of myogenin but not that of MyoD mRNA. Concurrently, iso-H7 increased myosin light-chain mRNA expression. In contrast, TPA had no effect on these syntheses. Taken together, these results showed that iso-H7 did not act intracellularly as a PKC inhibitor but rather as a PKA inhibitor as previously suggested. Our results are compatible with the hypothesis that a reduction in PKA activity controls satellite cell myogenesis through an increased myogenin mRNA expression.Abbreviations PKC protein kinase C - PKA cAMP-dependent protein kinase - CK creatine kinase - iso-H7 1-(5-isoquinolinesulfonyl)-3-methylpiperazine - H7 1-(5-isoquinolinesulfonyl)-2-methylpiperazine - HA 1004 N-(3-hydroxyethyl)-1-piperazine ethanesulfonate - TPA 12-O-tetradecanoyl phorbol 13-acetate - MLC myosin light chain - GAPDH glyceraldehyde 3-phosphate deshydrogenase     

初始底物浓度对序批式培养光合细菌产氢动力学影响

实验研究了初始底物浓度对序批式培养光合细菌生长、降解及产氢过程的影响,根据最大比生长速率实验数据拟合得到其关于初始底物浓度影响的关联式,并在建立的修正Monod模型基础上建立了光合细菌比生长速率、基质比消耗速率和比产氢速率关于底物初始浓度影响的数学模型,模型预测值与实验结果在光合细菌生长期和稳定期内得到较好吻合,反映了光合细菌生长、降解和产氢过程中受底物初始浓度限制性和抑制性影响的基本规律。分析发现光合细菌生长、降解基质和产氢过程中最适底物浓度为50 mmol/L,初始底物浓度低于或高于该浓度时,光合细菌生长、降解及产氢过程都受到限制性或抑制性影响,且抑制性影响较限制性影响效果更明显;底物比消耗速率受初始底物浓度影响较小。     

比格犬MC4R基因多态性与体重相关性的研究

为了分析比格犬黑素皮质素受体-4基因多态性与犬体重的关系, 根据犬MC4R基因DNA外显子序列, 设计MC4R基因特异PCR引物1对, 犬DNA经PCR扩增, 克隆和测序, 寻找和确定犬MC4R基因的多态性位点, 分析多态性与犬体重的关系。结果在比格犬MC4R基因中发现2处单碱基缺失突变, 1个单碱基颠换变异, 存在Psh AⅠ酶切位点, 并基于PshAⅠ酶切位点建立了PCR-RFLP技术。统计分析显示犬MC4R基因型与体重显著相关, 可以考虑将MC4R基因作为犬体重的候选基因。