Study on the expression and mutation of human telomeric repeat binding factor ( hTRF1 ) in 10 malignant hematopoietic cell lines

Objective: Detecting the expression and mutation of human telomeric repeat binding factor (hTRF1) in 10 malignant hematopoietic cell line cells on the base of determining its genomic structure and its four pseudogenes to clarify if hTRF1 mutation is one of the factors of the activation of telomerase. Methods: hTRF1cDNA sequences were obtained from GenBank, its genome structure and pseudogenes were forecasted by BLAST and other biology information programs and then testified by sequencing. Real-time RT-PCR was used to detect the expression of hTRF1mRNA in 10 cell line cells, including myelogenous leukemia cell lines K562, HL-60, U-937, NB4, THP-1, HEL and Dami; lymphoblastic leukemia cell lines 6T-CEM, Jurkat and Raji. Telomerase activities of cells were detected by using telomeric repeat amplification (TRAP)-ELISA protocol. PCR and sequencing were used to detect mutation of each exon of hTRF1 in 10 cell line cells. Results: hTRF1 gene, mapped to 8q13, was divided into 10 exons and spans 38.6 kb. Four processed pseudogenes of hTRF1 located on chromosome 13, 18, 21 and X respectively, was named as ψhTRF1-13, ψhTRF1-18, ψhTRF1-21 and ψhTRF1-X respectively. All cell line cells showed positive telomerase activity. The expression of hTRF1 was significantly lower in malignant hematopoietic cell lines cells (0.0338, 0.0108:_0.0749) than in normal mononuclear cells (0.0493, 0.0369:_0.128) (P=0.004). But no significant mutation was found in all exons of hTRF1 in 10 cell line cells. Four variants were found in part of intron 1, 2 and 8 of hTRF1. Their infection on gene function is unknown and needs further studies. Conclusion: hTRF1 mutation is probably not one of the main factors for telomerase activation in malignant hematopoietic disease. Project supported by the National Basic Research Program (973) of China (No. 2002CB713700) and the National Natural Science Foundation of China (No. 39870339)     

母语习得与外语学习对比

“习得”与“学习”是语言学中两个完全不同的语言学习过程。它们在语言环境、认知能力、情感因素、交际能力等方面存在着明显的异同。对母语习得的探讨与研究对外语学习具有重大意义。     

利用语块教学有效减少壮族预科学生母语负迁移作用

母语负迁移是影响词汇习得的重要因素。在学习环境和条件限制下,壮语的负迁移作用对壮族预科学生在英语习得过程中的影响非常明显。同时,壮族预科学生在其母语和汉语的双重影响下,这种负迁移具有其特点。利用语块的整体性和自动生成性等特点和优势的英语教学能有效减少由于壮语负迁移对壮族预科学生在英语习得的影响。     

组建一个安全高效的地震减灾中心网络系统

针对国内地震减灾系统建设现状,结合目前政府信息网络建设的优缺点,明确提出地震减灾中心网络系统的全面解决方案.     

关于一个平面1-集的不规则性

一个S-集必定是不规则集,除非S是整数.但S是整数的时候这个S-集可能是规则的,也可能是不规则的.为此,利用上密度和下密度来证明一个平面1-集的不规则性.     

二语写作中母语负迁移对句法层面的影响及对策

二语写作中母语负迁移的影响客观存在而且涉及到写作的各个环节。句子作为表达独立完整观点、构建段落篇章的基本单位起着至关重要的作用。因此,分析和探究母语负迁移对句法造成的影响有利于写作教学的有效开展。     

与时俱进是马克思主义生命力之所在——学习江泽民“七一”讲话的体会

中国共产党坚持将马克思主义和中国革命的具体实践相结合 ,出现了两次理论飞跃 ,形成了两大理论成果。中国共产党 80年奋斗历史说明 ,马克思主义是与时俱进的 ,正是这种与时俱进的理论品质 ,马克思主义才具有强大的生命力。江总书记的“七一”重要讲话 ,全面系统地论述了“三个代表”的重要思想 ,是一篇马克思主义的纲领性文献 ,本身就体现马克思主义所具有的与时俱进的理论品质 ,是马克思主义中国化的又一次历史性飞跃     

大学英语短文写作中的母语干扰因素分析

母语干扰是英语写作的一大障碍。本既从理论层面上探讨了母语对英语写作的几个关键因素的负面影响,又通过实例列举了学生在行过程中受母语干扰而出现的各种各样的“中式英语”错误,并就如何减少或排除这些干扰提出了具体的对策。