人的恶性高热和猪的应激综合征

人的恶性高热和猪的应激综合征是临床症状极其相似、遗传方式不同的两种代谢障碍性疾病,它们直接威胁着人类的生命安全和畜牧业生产。随着医学和基因工程技术的发展,有关专家对这两种病的认识在９０年代初取得了突破性进展。本文在回溯这两种疾病的历史背景的基础上,将...     

FT Ⅰ, a novel positive myeloid-lineage-specific transcription regulatory element within the mouse myeloperoxidase gene enhancer, En 1

INTanDUCTI0NMyeloidcelldifferentiati0n,inwhichmultip0tentialprogenitorcellsarec0nvertedint00neofthesixmaturedifferentiatedcells,i.e.,erythr0cytes,platelets(megakary-ocytes),macr0phages,neutr0phils,e0sinophilsandbas0phils,involvestemporalre-gulati0nofexpression0fanumberoflineage-anddifferentiationstage-specificgenes.Understandingthedevel0pmentalspecificationoflineageaJswellasmaturationstageassociatedpatterns0fgeneexpressioninmyel0idcelldifferentiationrequiresanin-sightintothecontrol0findivid…     

Distribution and Significance of Nitric Oxide Synthase in Brain Tissues of Rats Exposed to Deltamethrin Insecticide

The distribution of nitric oxide synthase(NOS)in brain tissues of rats exposed to deltamethrininsecticide has been examined by histochemical NADPH-diaphorase staining techniques on frozen sec-tions.After injection of deltamethrin(12.5mg/kg,i.p.),a reproducible sequence of toxic signs ofhyperexcitability were elicited.The observation and image analysis showed that,within brain sec-tions of rats exposed to deltamethrin,the numbers and the total staining areas of the NOS positiveneurons were greatly increased,especially in cerebral cortex,hippocampal formation and paraventric-ular nucleus.In addition,the density of single neuron and the processes were also increased.The re-sults suggested that deltamethrin may induce the NOS expression or activate the NOS activity.TheNOS activation may involve in the chains responsible for the excitatory neurotoxicities induced bydeltamethrin.     

Impacts of population growth and economic development on the nitrogen cycle in Asia

Asia is the major consumer of fertilizer nitrogen and energy in the world, and consequently shares a considerable proportion of the world creation of reactive nitrogen (Nr). However, if estimated on per capita basis, Asia is characterized by a lower arable land area, fertilizer nitrogen consumption, energy consumption, and gross domestic product, as well as lower daily protein intake. To meet the increasing needs for food and energy for the growing population combined with the improvement of living standards, Nr will inevitably increase. The present study estimates the creation of Nr and the emissions of various N compounds into environment in Asia currently and in 2030. In comparison with the world averages, the lower fertilizer nitrogen and energy use efficiencies, and the lower use of animal wastes for agriculture imply that there is potential for moderating the increase in Nr and its impacts on the environment. Strategies for moderating the increase are discussed.     

Effect of Human WEE1 and Stem Cell Factor on Human CD34^＋ Umbilical Cord Blood Cell Damage Induced by Chemotherapeutic Agents

Myelosuppression is one of the major side-effects of most anticancer drugs. To achieve myeloprotection, one bicistronic vector encoding anti-apoptotic protein human WEE l （WEElHu） and proliferation-stimulating stem cell factor （SCF） was generated. In this study, we selected human umbilical cord blood CD34^＋ cells as the in vitro model in an attempt to investigate whether WEEIHu, rather than conventional drug-resistant genes, can be introduced to rescue cells from the damage by chemotherapeutic agents such as cisplatin, adriamycin, mitomycin-c and 5-fluorouracil. Cell viability and cytotoxicity assay, colony-forming units in culture assay and externalization of phospholipid phosphatidylserine analysis showed that the expression of WEElHu and SCF in CD34^＋ cells provided the cells with some protection. These findings suggest that the expression of WEElHu and SCF might rescue CD34^＋ cells from chemotherapyinduced myelosuppression.     

中华鳖精母细胞联会复合体的研究

本文以微铺展技术制备中华鳖精母细胞联会复合体标本,经硝酸银染色后电镜观察,分析了SC组型。并与有丝分裂染色体组型相比较,发现二者有着良好的一致性,而且微小染色体的SC结构和着丝粒清晰,未发现形态上有分化的性染色体。中华鳖SC的研究为其细胞遗传学及性别决定机制提供了重要的依据。 Abstract　Synaptonemal Complexes (SC) in Trionyx sinensis spermatocytes prepared with micro-spreading technique and silver staining was analyzed by electron microscopy. The meiotic SC karyotype was constructed from 10 cells and compared with mitotic chromosome karyotype. There is a good agreement between them. The structure and kinetochores of micro-chromosomes are very distinctive on each SC. There does not exist differential sex chromosome.     

基因靶位操作的技术与应用

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Phylogenetic clusters of rhizobia revealed by genome structures

Rhizobiaareagriculturallyandenvironmentallyimportantbacteria.Theirsymbiosiswithleguminousplantsisresponsibleformostoftheatmosphericni-trogenfixedonland.Classificationofthesebacteriabasedontheirnaturalrelationshipswillpromotetheirapplication.Thisresearchemploysanewphylogeneticmethod,i.e.,revelationandcomparisonofgenomestructure,tocategorizerhizobia.Phylogenyisthestudyoftheevolutionaryrelationshipsamongorgan-isms[1].Currentlyphylogeneticrelationshipsamongrhizobiaaremostlyinferredfromcomparisons…     

PCR-RFLP检测LDL受体基因TaqⅠ多态性位点的研究

应用聚合酶链反应(PCR)扩增人类LDL受体基因外显子4-内含子4-外显子5片段,PCR产物为1.55kb,DNA片段经序列鉴定后,进行TaqI酶切位点的RFLP分析。结果显示:中国汉族人群LDL受体基因中存在着TaqⅠ酶切位点多态性; 200个LDL受体等位基因中TaqⅠ酶切位点出现的频率为0.515,该点频率较为适中, 可作为中国汉族人群LDL受体基 因的遗传标志来进行家族性高胆固醇血症(FH)的基因诊断。所建立起的LDL受体基因TaqⅠ位点的PCR -RFLP方法具有快速、简便的特点,在FH的基因诊断上有应用价值。 Abstract:To develop rapid and sensitive technique for detectin the TaqI polymorphism at the human LDL receptor gene in Chinese,the exon4-intron4-exon5 of the human LDL receptor gene was amplified by polymerase chain reaction(PCR).The PCR products were directly analysed by restriction fragment length polymorphisms(RFLP).The results showed that the TaqI polymorphism is associated with the LDL receptor gene in Chinese of Han nationality;The frequency of T= allele (presence of TaqI cutting site)is 0.515 in 200 LDL receptor alleles.This technique may be used for rapid and sensitive screening of the LDL receptor gene for the TaqI polymorphism.     

纬度变化对不同冬小麦品种蛋白质组分的影响

选用6个有代表性的冬小麦品种在河南省5个不同纬度试验点（32°—36°N）进行种植,研究纬度变化对冬小麦蛋白质组分含量的影响.结果表明：纬度变化对冬小麦清蛋白、麦谷蛋白含量和谷/醇比值有显著影响,而基因型差异对蛋白质组分的影响不显著.随着纬度的升高,清蛋白和醇溶蛋白含量呈降低趋势,而麦谷蛋白含量、谷/醇比值、蛋白质组分之和及小麦产量呈递增趋势.与其他试验点相比,信阳种植的6个小麦品种的清蛋白含量相对较高,驻马店和许昌的醇溶蛋白含量较高,而武陟和汤阴的麦谷蛋白含量较高.5月份平均气温、总日照时数和降雨量与小麦蛋白质组分地点间变化关系密切.因此,生产上选择适宜的小麦种植区,同时可在5月份采取改善光合作用、延长灌浆时间等栽培措施,以提高小麦籽粒品质.