Anti-HIF-1α-pEGFP重组质粒的构建及表达

目的构建EGFP-HIF-1α反义重组质粒,转染人宫颈癌Hela细胞,用以探讨HIF-1α蛋白在宫颈癌的生长、转移中的作用。方法应用基因重组技术构建EGFP-HIF-1α反义重组质粒,通过脂质体介导将其转染入Hela细胞,倒置荧光显微镜观察转染效果,Western blot检测HIF-1α蛋白的表达。结果酶切鉴定结果显示含EGFP-HIF-1α反义重组质粒构建成功,并能在Hela细胞中封闭HIF-1α蛋白的表达。结果 EGFP-HIF-1α反义重组质粒构建及转染成功,封闭Hela细胞中HIF-1α蛋白的表达,为进一步研究HIF-1α蛋白在宫颈癌的生长、转移中的作用提供试验基础。     

转录因子与造血调控

血细胞生成是一个极其复杂的过程,转录因子在这个过程中起到了重要的调控作用。而转录因子的表达具有阶段和细胞系特异性。在造血干细胞的增殖和分化、髓系和淋巴系细胞等的成熟过程中,众多转录因子既相互作用又表现出各自的特异性。转录因子数目较多,该文仅就一些与造血细胞分化、成熟相关的转录因子近年来的研究进展作一介绍。     

黄土高原半干旱区刺槐生长盛期树干液流动态

通过研究树干液流速率与气象因子的关系,可以定量地分析树木生长与群落蒸腾耗水的相互关系,揭示黄土高原半干旱区刺槐水分利用动态及其适应环境因子的内在机理,为当地生态环境建设提供理论依据。应用热扩散式树干茎流计(TDP)于2008年7月1日至7月26日,在黄土高原半干旱区安塞县对刺槐(Robinia pseudoacacia)人工林生长盛期树干液流速率进行了连续测定,并对周围气象、土壤水分等指标进行了同步测定。刺槐生长盛期树干液流速率晴天日变化呈宽峰形曲线,在测量时期液流速率日平均值为0.00133cm·s–1;刺槐树干单位边材面积的液流速率与光合有效辐射、大气温度、水汽压差呈极显著正相关关系,与相对湿度呈负相关关系。其相关程度绝对值顺序为光合有效辐射大气温度水汽压差相对湿度风速;刺槐边材面积与胸径之间存在着显著的线性相关关系,相关系数为0.878,单位边材面积的液流速率随树干胸径的增大而减小。     

大杯香菇辐射选育新株系数量性状的因子分析

对20个大杯香菇品种和辐射选育新株系的数量性状进行因子分析.结果表明,20个大杯香菇品种和辐射选育新株系的18个数量性状,可提取为7个公因子,其累积方差贡献率达91.85 %,代表了所有性状绝大部分相关信息.按照主因子所包含的性状及其所反映的生物学、营养学和酶学含义,可把7个主因子命名并按方差贡献大小顺序排列为：促长因子1、CAT活性因子2、营养质量因子3、MDA因子7、化学评分因子4、氨基酸比值系数分因子5、粗壮因子6.从主因子出发进行大杯香菇辐射育种,可以加大目标性状的针对性的选择效率,比较容易获得综合数量性状优良的新品种.     

The HDL hypothesis: does high-density lipoprotein protect from atherosclerosis?

There is unequivocal evidence of an inverse association between plasma high-density lipoprotein (HDL) cholesterol concentrations and the risk of cardiovascular disease, a finding that has led to the hypothesis that HDL protects from atherosclerosis. This review details the experimental evidence for this “HDL hypothesis”. In vitro studies suggest that HDL has a wide range of anti-atherogenic properties but validation of these functions in humans is absent to date. A significant number of animal studies and clinical trials support an atheroprotective role for HDL; however, most of these findings were obtained in the context of marked changes in other plasma lipids. Finally, genetic studies in humans have not provided convincing evidence that HDL genes modulate cardiovascular risk. Thus, despite a wealth of information on this intriguing lipoprotein, future research remains essential to prove the HDL hypothesis correct.     

Extent of cell differentiation and capacity for cartilage synthesis in human adult adipose‐derived stem cells: Comparison with fetal chondrocytes

This study evaluated the extent of differentiation and cartilage biosynthetic capacity of human adult adipose‐derived stem cells relative to human fetal chondrocytes. Both types of cell were seeded into nonwoven‐mesh polyglycolic acid (PGA) scaffolds and cultured under dynamic conditions with and without addition of TGF‐β1 and insulin. Gene expression for aggrecan and collagen type II was upregulated in the stem cells in the presence of growth factors, and key components of articular cartilage such as glycosaminoglycan (GAG) and collagen type II were synthesized in cultured tissue constructs. However, on a per cell basis and in the presence of growth factors, accumulation of GAG and collagen type II were, respectively, 3.4‐ and 6.1‐fold lower in the stem cell cultures than in the chondrocyte cultures. Although the stem cells synthesized significantly higher levels of total collagen than the chondrocytes, only about 2.4% of this collagen was collagen type II. Relative to cultures without added growth factors, treatment of the stem cells with TGF‐β1 and insulin resulted in a 59% increase in GAG synthesis, but there was no significant change in collagen production even though collagen type II gene expression was upregulated 530‐fold. In contrast, in the chondrocyte cultures, synthesis of collagen type II and levels of collagen type II as a percentage of total collagen more than doubled after growth factors were applied. Although considerable progress has been achieved to develop differentiation strategies and scaffold‐based culture techniques for adult mesenchymal stem cells, the extent of differentiation of human adipose‐derived stem cells in this study and their capacity for cartilage synthesis fell considerably short of those of fetal chondrocytes. Biotechnol. Bioeng. 2010;107: 393–401. © 2010 Wiley Periodicals, Inc.