Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) sho...Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) showed many important mutations. The homology of these two strains was 98.17%. Then H gene was cloned into expression vector pCD SRα296 and introduced into COS 7 cells by electroporation method. The expression and function of cloned H gene was checked by hemadsorption assays.展开更多
Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to e...Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to easily determine the cell incorporation of TiO2 NPs or related DNA damage, and to date, few studies have examined the different degrees of incorporation into cells according to the size of the TiO2 NPs particles and the presence or absence of cell specificity regarding DNA damage. This present study was therefore designed to examine COS7 cells that had incorporated TiO2 NPs using atmospheric scanning electron microscopy (ASEM). The results indicated that absorption of TiO2 NPs into cells and nuclear abnormalities had occurred. ASEM is a rapid and simple technique that enables the observation of samples immediately after fixation with glutaraldehyde and staining with phosphotungstic acid, and this method was suggested to be useful in screening for DNA damage.展开更多
目的:寻找血管紧张素Ⅱ1型受体(angiotensinⅡ type 1 receptor,AT1受体)上的机械负荷感受位点。方法:制备AT1受体不同位点的突变体,转染既不表达血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)也不表达AT1的COS7细胞,Western blotting法检测细胞...目的:寻找血管紧张素Ⅱ1型受体(angiotensinⅡ type 1 receptor,AT1受体)上的机械负荷感受位点。方法:制备AT1受体不同位点的突变体,转染既不表达血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)也不表达AT1的COS7细胞,Western blotting法检测细胞牵张后细胞外信号调节激酶(ERKs)的磷酸化水平。结果:构建了C76A、K199Q、H256A、Q257A、C289A、C296A、K199Q/H256A、K199Q/Q257A8种突变体。COS7细胞转染AT1受体以前,AngⅡ和牵张刺激都不能引起细胞内ERKs磷酸化升高;而转染野生型AT1后,AngⅡ和牵张刺激引起细胞内ERKs磷酸化明显升高,各突变体中,Q257A和C289A转染细胞后细胞对牵张刺激的反应受到明显抑制,提示AT1的牵张感受位点在Q257A和C289A。结论:结果提示AT1受体上位于257位的谷氨酰胺和289位的胱氨酸在机械牵张引起的AT1受体激活中起了重要作用。展开更多
文摘Hemagglutinin gene of Measles virus(Nepal strain) was amplified by RT PCR technique, cloned and sequenced by the dideoxy mediated chain termination method. The comparison to the standard strain(Edmonston strain) showed many important mutations. The homology of these two strains was 98.17%. Then H gene was cloned into expression vector pCD SRα296 and introduced into COS 7 cells by electroporation method. The expression and function of cloned H gene was checked by hemadsorption assays.
文摘Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to easily determine the cell incorporation of TiO2 NPs or related DNA damage, and to date, few studies have examined the different degrees of incorporation into cells according to the size of the TiO2 NPs particles and the presence or absence of cell specificity regarding DNA damage. This present study was therefore designed to examine COS7 cells that had incorporated TiO2 NPs using atmospheric scanning electron microscopy (ASEM). The results indicated that absorption of TiO2 NPs into cells and nuclear abnormalities had occurred. ASEM is a rapid and simple technique that enables the observation of samples immediately after fixation with glutaraldehyde and staining with phosphotungstic acid, and this method was suggested to be useful in screening for DNA damage.
文摘目的:寻找血管紧张素Ⅱ1型受体(angiotensinⅡ type 1 receptor,AT1受体)上的机械负荷感受位点。方法:制备AT1受体不同位点的突变体,转染既不表达血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)也不表达AT1的COS7细胞,Western blotting法检测细胞牵张后细胞外信号调节激酶(ERKs)的磷酸化水平。结果:构建了C76A、K199Q、H256A、Q257A、C289A、C296A、K199Q/H256A、K199Q/Q257A8种突变体。COS7细胞转染AT1受体以前,AngⅡ和牵张刺激都不能引起细胞内ERKs磷酸化升高;而转染野生型AT1后,AngⅡ和牵张刺激引起细胞内ERKs磷酸化明显升高,各突变体中,Q257A和C289A转染细胞后细胞对牵张刺激的反应受到明显抑制,提示AT1的牵张感受位点在Q257A和C289A。结论:结果提示AT1受体上位于257位的谷氨酰胺和289位的胱氨酸在机械牵张引起的AT1受体激活中起了重要作用。
