Polycyclic aromatic hydrocarbons(PAHs),dimethyl beazanthracene(DMBA)and benzo-(a)-pyrene(BaP),stimulate the expression of the P1-450 gene in human lung tumor cells(ChaGo)in culture.A concentration-and time-dependent i...Polycyclic aromatic hydrocarbons(PAHs),dimethyl beazanthracene(DMBA)and benzo-(a)-pyrene(BaP),stimulate the expression of the P1-450 gene in human lung tumor cells(ChaGo)in culture.A concentration-and time-dependent increase in the level of P1-450 specific mRNA sequences hasbeen observed in ChaGo cells treated with sublethal concentrations of DMBA.Results presentedsuggest that the parent compound causes the induction of P1-450 gene expression.The methylationpattern of the internal“-C-” residues of the “-CCGG-” sequence has been studied in a stretch ofabout 8000 base pairs(bp)of DNA sequence in and around the P1-450 gene in the control andDMBA-treated ChaGo cells.A comparative Southern blot analysis of the Msp Ⅰ/Hpa Ⅱ digestedDNA of the control and DMBA-treated ChaGo cells followed by hybridization with ^(32)P-labelledregion-specific probes,revealed that i)the internal “-C-” residues of the “-CCGG-” sequences ofdifferent regions of P1-450 gene were methylated to different degrees;ii)DMBA treatment of thecells induced hypomethylation of only the 5' end “-CCGG-” sequences of the gene;and iii)themethylation patterns of “-CCGG-” sequences of most of the coding region and of the 3' end regionof P1-450 gene were not affected by such DMBA treatment.展开更多
Cancer cells show characteristic alterations in DNA methylation patterns. Aberrant CpG methylation of specificpromoters results in inactivation of tumor suppressor genes and therefore plays an important role in carcin...Cancer cells show characteristic alterations in DNA methylation patterns. Aberrant CpG methylation of specificpromoters results in inactivation of tumor suppressor genes and therefore plays an important role in carcinogenesis. Thep53-regulated gene 14-3-3σ undergoes frequent epigenetic silencing in several types of cancer, including carcinoma ofthe breast, prostate, and skin, suggesting that the loss of 14-3-3σ expression may be causally involved in tumor progression.Functional studies demonstrated that 14-3-3σ is involved in cell-cycle control and prevents the accumulation of chro-mosomal damage. The recent identification of novel 14-3-3σ-associated proteins by a targeted proteomics approachimplies that 14-3-3σ regulates diverse cellular processes, which may become deregulated after silencing of 14-3-3σexpression in cancer cells.展开更多
The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop...The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of synthesis.Indeed,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating conditions.The structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and MS.The results revealed that the experimental study is in good correlation with the computational one.展开更多
为探明春油菜田野燕麦(Avena fatua L.)对高效氟吡甲禾灵抗性生理机制,在实验室对抗性生物型野燕麦和敏感性生物型喷施高效氟吡甲禾灵后测定了相关生理指标的变化,结果表明喷施高效氟吡甲禾灵EC375 m L/hm2后,野燕麦敏感种群(S)的叶绿...为探明春油菜田野燕麦(Avena fatua L.)对高效氟吡甲禾灵抗性生理机制,在实验室对抗性生物型野燕麦和敏感性生物型喷施高效氟吡甲禾灵后测定了相关生理指标的变化,结果表明喷施高效氟吡甲禾灵EC375 m L/hm2后,野燕麦敏感种群(S)的叶绿素含量呈逐渐降低的趋势,抗性种群(R)的叶绿素含量变化趋势不明显;野燕麦抗性种群(R)喷药处理后丙二醛含量始终很低,敏感种群(S)随着药剂胁迫时间的延长,施药与未施药处理后的丙二醛含量的差异明显;敏感野燕麦种群(S)施药和未施药处理后CAT的活性差异比较显著,抗性种群(R)施药后的CAT活性与未施药的CAT活性差异不显著。研究得出敏感野燕麦生物型生理变化较大,高抗野燕麦生物型具有一定的生理适应性,生理变化较小。展开更多
为评价高效氟吡甲禾灵在马铃薯中使用的安全性,开展高效氟吡甲禾灵在马铃薯和土壤中的残留量及残留消解研究。进行2年2地田间试验。消解动态试验按高效氟吡甲禾灵337. 5 g/hm2(94. 5 g a. i/hm2,推荐最高剂量的1. 5倍)施药;最终残留试...为评价高效氟吡甲禾灵在马铃薯中使用的安全性,开展高效氟吡甲禾灵在马铃薯和土壤中的残留量及残留消解研究。进行2年2地田间试验。消解动态试验按高效氟吡甲禾灵337. 5 g/hm2(94. 5 g a. i/hm2,推荐最高剂量的1. 5倍)施药;最终残留试验按高效氟吡甲禾灵337. 5 g/hm2(94. 5 g a. i/hm2,推荐最高剂量的1. 5倍)和225 g/hm2(63 g a. i/hm2,推荐最高剂量)施药,收获期采样。气相色谱质谱法对高效氟吡甲禾灵进行定量分析。田间消解动态试验表明:高效氟吡甲禾灵在马铃薯植株和土壤中消解较快,半衰期分别为4. 8～8. 9 d、8. 3～14. 2 d。最终马铃薯中高效氟吡甲禾灵的残留量均低于最低检测浓度(<0. 01 mg/kg)。该方法,准确可靠。收获期马铃薯中高效氟吡甲禾灵残留低于我国规定的农药最高残留限量值(0. 1mg/kg)。展开更多
基金This work is supported by grant(HL32034) from the U.S.National Institute of Heart,Lung and Blood.
文摘Polycyclic aromatic hydrocarbons(PAHs),dimethyl beazanthracene(DMBA)and benzo-(a)-pyrene(BaP),stimulate the expression of the P1-450 gene in human lung tumor cells(ChaGo)in culture.A concentration-and time-dependent increase in the level of P1-450 specific mRNA sequences hasbeen observed in ChaGo cells treated with sublethal concentrations of DMBA.Results presentedsuggest that the parent compound causes the induction of P1-450 gene expression.The methylationpattern of the internal“-C-” residues of the “-CCGG-” sequence has been studied in a stretch ofabout 8000 base pairs(bp)of DNA sequence in and around the P1-450 gene in the control andDMBA-treated ChaGo cells.A comparative Southern blot analysis of the Msp Ⅰ/Hpa Ⅱ digestedDNA of the control and DMBA-treated ChaGo cells followed by hybridization with ^(32)P-labelledregion-specific probes,revealed that i)the internal “-C-” residues of the “-CCGG-” sequences ofdifferent regions of P1-450 gene were methylated to different degrees;ii)DMBA treatment of thecells induced hypomethylation of only the 5' end “-CCGG-” sequences of the gene;and iii)themethylation patterns of “-CCGG-” sequences of most of the coding region and of the 3' end regionof P1-450 gene were not affected by such DMBA treatment.
文摘Cancer cells show characteristic alterations in DNA methylation patterns. Aberrant CpG methylation of specificpromoters results in inactivation of tumor suppressor genes and therefore plays an important role in carcinogenesis. Thep53-regulated gene 14-3-3σ undergoes frequent epigenetic silencing in several types of cancer, including carcinoma ofthe breast, prostate, and skin, suggesting that the loss of 14-3-3σ expression may be causally involved in tumor progression.Functional studies demonstrated that 14-3-3σ is involved in cell-cycle control and prevents the accumulation of chro-mosomal damage. The recent identification of novel 14-3-3σ-associated proteins by a targeted proteomics approachimplies that 14-3-3σ regulates diverse cellular processes, which may become deregulated after silencing of 14-3-3σexpression in cancer cells.
基金Supported by the Centre National de la Recherche Scientifique et Techniques,Rabat,Morocco(No.PROTARS D13/03).
文摘The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent years.In the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of synthesis.Indeed,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating conditions.The structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and MS.The results revealed that the experimental study is in good correlation with the computational one.
文摘为探明春油菜田野燕麦(Avena fatua L.)对高效氟吡甲禾灵抗性生理机制,在实验室对抗性生物型野燕麦和敏感性生物型喷施高效氟吡甲禾灵后测定了相关生理指标的变化,结果表明喷施高效氟吡甲禾灵EC375 m L/hm2后,野燕麦敏感种群(S)的叶绿素含量呈逐渐降低的趋势,抗性种群(R)的叶绿素含量变化趋势不明显;野燕麦抗性种群(R)喷药处理后丙二醛含量始终很低,敏感种群(S)随着药剂胁迫时间的延长,施药与未施药处理后的丙二醛含量的差异明显;敏感野燕麦种群(S)施药和未施药处理后CAT的活性差异比较显著,抗性种群(R)施药后的CAT活性与未施药的CAT活性差异不显著。研究得出敏感野燕麦生物型生理变化较大,高抗野燕麦生物型具有一定的生理适应性,生理变化较小。
文摘为评价高效氟吡甲禾灵在马铃薯中使用的安全性,开展高效氟吡甲禾灵在马铃薯和土壤中的残留量及残留消解研究。进行2年2地田间试验。消解动态试验按高效氟吡甲禾灵337. 5 g/hm2(94. 5 g a. i/hm2,推荐最高剂量的1. 5倍)施药;最终残留试验按高效氟吡甲禾灵337. 5 g/hm2(94. 5 g a. i/hm2,推荐最高剂量的1. 5倍)和225 g/hm2(63 g a. i/hm2,推荐最高剂量)施药,收获期采样。气相色谱质谱法对高效氟吡甲禾灵进行定量分析。田间消解动态试验表明:高效氟吡甲禾灵在马铃薯植株和土壤中消解较快,半衰期分别为4. 8～8. 9 d、8. 3～14. 2 d。最终马铃薯中高效氟吡甲禾灵的残留量均低于最低检测浓度(<0. 01 mg/kg)。该方法,准确可靠。收获期马铃薯中高效氟吡甲禾灵残留低于我国规定的农药最高残留限量值(0. 1mg/kg)。
