研究生在基础与临床相结合科研项目中培养方法的几点思考

随着我国科研创新的开展与推进,学生进入实际科研项目已逐渐成为研究生培养的重要方式。基础与,临床相结合的科研项目立论均来自于临床问题,把在患者身上无法实现的方法通过基础实验的手段加以实施和验证,从而达到发现和揭示病因与发病机制的目的,结果甚或对临床产生指导意义。首都医科大学病理与病理生理学系研究生培养点结合这类研究项目的推进,在规范的方法和流程中引导和培养研究生从临床现象中设问、从海量数据中分析和论证的能力,并通过这些训练,使研究生为进一步深入研究奠定基础,共同为转化医学研究做出贡献。     

智力低下患者的手纹分析

本文对安徽合肥和芜湖地区284例（男145人,女139人）2－59岁智力低下患者的手纹进行了分析。结果表明：患者的皮纹参数与正常对照组有明显的统计学差异,其中尺箕、箕／箕组合、帐弓、皮纹密度、atd角、t距比、掌褶通贯型、悉尼型、过渡Ⅰ型和小指短小类型等项参数均高于对照组（P＜0.01);而简斗、斗／斗组合、a-dRC、t-dRC低于对照组（P＜0.01),a-bRC亦低于对照组（P＜0.05)。这些皮纹参数可以作为智力低下患者的辅助诊断指标。     

发酵抑制物对絮凝酵母戊糖发酵的影响

将絮凝剂加入酵母溶液中,使酵母絮凝成颗粒以此作为固定化酵母进行戊糖发酵。研究了常见发酵抑制物(甲酸、乙酸、糠醛和乳酸等)对絮凝酵母发酵木糖的影响。结果表明:在60.0g/L木糖发酵液中,经过24h发酵,木糖利用率达94.6%,当分别添加抑制物甲酸、乙酸、糠醛、乙醇和乳酸时,聚氧乙烯絮凝酵母分别对其的耐受浓度为0.5、0.5、1.0、30.0和8.0g/L。当抑制物添加量超过各自的耐受浓度后,对絮凝酵母发酵会产生明显的抑制作用。     

轴浆转运在神经再生中的作用

夹伤坐骨神经阻断标记蛋白在轴浆中的快、慢转运。3天后转运再现。第14天的转运距离与对照相似,说明再生神经的转运动能基本恢复。用快、慢转运测出的14天平均再生速度分别为1.77±0.14与1.96±0.07mm/d,比对照神经的正常生长速度快6.3—7倍,提示再生需要更多的转运物质。进一步发现再生神经中某些标记蛋白(慢转运波W1)的转运速度为10.25±0.66mm/d,约比对照快1倍,因此这些标记蛋白可能包含适应再生需要而加速转运的结构和功能物质。     

木糖高效生物转化的新出路

木糖的高效利用是影响木质纤维资源生物炼制经济效益的关键因素之一,也是构建其工业化生产体系的必要前提,但是木糖生物转化面临着重要的技术瓶颈,必须寻求新的思路。基于对木糖利用的现状及产业发展的综合分析,提出了木糖高效发酵制取木糖酸的新出路,论述了本领域首要的科学和技术问题是发酵抑制物的控制与消除;针对抑制物的问题,提出了细胞生理生化、代谢流分析及分子生物学的多层次和多尺度解析的研究方法;在此基础上,基于系统论的观点提出了菌种选育、原料预处理、抑制物控制与脱除、木糖酸高效发酵的技术集成的研究思路。     

2010年冬季寒冷天气对闽江口3种红树植物幼苗的影响

2010年10月8日-2011年2月26日,跟踪监测了闽江河口互花米草治理试验区人工种植的秋茄(Kandelia candel)、无瓣海桑(Sonneratia apetala)和拉关木(Leguncalaria racemosa)1年生幼苗叶片相溶性物质含量以及活性氧代谢等生理生化指标.结果表明:可溶性糖和脯氨酸含量均随气温的逐步降低而增加,秋茄可溶性糖含量最高,拉关木脯氨酸含量最高;整个监测期无瓣海桑和拉关木幼苗叶片超氧阴离子(O2)产生速率显著高于秋茄(P＜0.01),而超氧化物歧化酶(SOD)和过氧化物酶(POD)活性显著低于秋茄(P＜0.01);3种植物叶片丙二醛(MDA)含量及电解质渗透率均随着气温的降低而增加,其中无瓣海桑和拉关木MDA含量及电解质渗透率与日最低气温为显著和极显著的负相关关系.2010年冬季持续寒冷天气对闽江河口湿地1年生土著种秋茄幼苗无破坏,对引进种无瓣海桑和拉关木造成了严重的低温胁迫并使幼苗基本全部死亡.     

影响芋茎尖培养中脱毒和快速繁殖的几个生理因素

以3个芋品种（‘石川早生’、‘虾籽芋’、‘叶用芋）球茎茎尖为外植体,进行脱病毒和快繁的结果表明,外植体表面灭菌的最佳方法是剥鳞片→乙醇→新洁尔灭→剥幼叶→氯化汞;适宜茎尖分化的培养基为MS＋1．0-2．0mg·L^-16-BA＋0．2mg·L^-1 NAA。生物学方法和电镜观察显示：连续3代0．5-0．7mm茎尖剥离培养对芋花叶病毒（DMV）的脱毒率达100％。在培养基MS＋0．2mg·L^-1 NAA中,适量添加6-BA和TDZ,三品种芋的试管苗增殖效果好;附加KT,试管苗生长健壮且利于生根：添加20-100mg·L^-1的精胺（spm）,可促进不定芽的发生,与KT配合使用可促使继代增殖和成苗一步完成。完整植株在草炭土：蛭石=1：1的基质中,移栽成活率超过97％,且苗生长健壮。     

Genetic uniformity characterizes the invasive spread of water hyacinth (Eichhornia crassipes), a clonal aquatic plant

Aquatic plant invasions are often associated with long‐distance dispersal of vegetative propagules and prolific clonal reproduction. These reproductive features combined with genetic bottlenecks have the potential to severely limit genetic diversity in invasive populations. To investigate this question we conducted a global scale population genetic survey using amplified fragment length polymorphism markers of the world’s most successful aquatic plant invader –Eichhornia crassipes (water hyacinth). We sampled 1140 ramets from 54 populations from the native (South America) and introduced range (Asia, Africa, Europe, North America, Central America and the Caribbean). Although we detected 49 clones, introduced populations exhibited very low genetic diversity and little differentiation compared with those from the native range, and ～80% of introduced populations were composed of a single clone. A widespread clone (‘W’) detected in two Peruvian populations accounted for 70.9% of the individuals sampled and dominated in 74.5% of the introduced populations. However, samples from Bangladesh and Indonesia were composed of different genotypes, implicating multiple introductions to the introduced range. Nine of 47 introduced populations contained clonal diversity suggesting that sexual recruitment occurs in some invasive sites where environmental conditions favour seedling establishment. The global patterns of genetic diversity in E. crassipes likely result from severe genetic bottlenecks during colonization and prolific clonal propagation. The prevalence of the ‘W’ genotype throughout the invasive range may be explained by stochastic sampling, or possibly because of pre‐adaptation of the ‘W’ genotype to tolerate low temperatures.     

phbB,phbC Gene Expression in E. coli and Their Transformation and Identification in Potato

Using NADPH-dependent acetoacetyl-CoA reductase gene (phbB) and poly-β-hydroxybutyrate (PHB) synthase gene (phbC) cloned from Alcaligenes eutrophus H16 and expression vector pKK223-3, the authors constructed an E. coli expression vector pKCB containing independent phbB and phbC operators, respectively, and transfered it into E. coli JM109. The microscopy and GC analysis indicated that E. coli JM109 (containing pKCB) induced by IPTG could synthesize poly-β- hydroxybutyrate (PHB). By DNA processing, three tuber-specific plant expression vectors, pP- SAGB (containing phbB), pBIBGC ( containing phbC) and pPSAGCB ( containing both phbB and phbC), were successfully constructed. In 5 transformed potato cuhivars, the authors screened 20 positive lines.     

Human chromosome pellicle antibody recognizing centromere protein-C (CENP-C), the main component of the kinetochore

INTRODUCTIONDuringnormalcelldivision,thechromosomesplitsevenly,givingthesamegeneticmaterialtoeachdaughtercell.Theaccuracyofsuchcelldivisiondependsontheinteractionbetweenthespindleapparatusandtheets--actingregionofeachchromosomeknownasthecentromere.Manyessentialmitoticfunctionsoccuratorarecontrolledbythecentromere.Capturingspindlemicrotubules,thegrowthanddisassemblyofmicrotubules,theliningupofchromosomesonthemetaphaseplate,andthesplittingoffofthesisterchromatidsduringmitosisareallsomehowre…