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| 1 | 干扰与生态系统演替的空间分析显示文摘演替不光是生态系统在时间序列上的替代过程,而且也是生态系统在空间上的动态演变。演替的空间属性有演替系列的格局、范围、尺度、演替方向和速率、稳定的程度、多样性、以及在自然和人为干扰下的恢复等。干扰破坏了生态系统的稳定性,形成生态系统结构和功能的破损,使生态系统处于一种过渡状态。但是干扰也是生态系统演替的外在驱动力,自然的和人为的干扰引起的生态系统的对称性破缺,推动了系统的进化和演变。外界因素作用于生态系统的干扰因子包含了很多种类,如火、风倒、洪水、病虫害、人类活动等。干扰的属性有范围、频度、季节、强度、损害度、返回时间和循环周期。讨论了这些干扰的类型和生态系统演替所具有空间的特征,并且介绍了干扰和生态系统演替空间分析常用的方法,如空间解绎和辨识、空间统计分析、空间格局分析和地理信息系统的空间分析、以及空间模拟。利用了一些典型的实例来深入阐明空间分析在干扰和生态系统演替中的应用。利用美国加利福尼亚北部火干扰的历史和空间分布的记录,进行了火干扰的空间分析的研究;用Spies等在美国俄勒冈州西部1972~1988年的多时段的变化的实例说明了收获干扰的影响;利用俄勒冈州东部山地的主要两个虫害(山地松树甲虫(MountainPineBeetle) | 江洪 张艳丽 JamesRStrittholt | 2003 | 生态学报2003，23，9： | 78 |
| 2 | SVM with Quadratic Polynomial Kernel Function Based Nonlinear Model One-step-ahead Predictive Control显示文摘A support vector machine (SVM) with quadratic polynomial kernel function based nonlinear model one-step-ahead predictive controller is presented. The SVM based predictive model is established with black-box identification method. By solving a cubic equation in the feature space, an explicit predictive control law is obtained through the predictive control mechanism. The effect of controller is demonstrated on a recognized benchmark problem and on the control of continuous-stirred tank reactor (CSTR). Simulation results show that SVM with quadratic polynomial kernel function based predictive controller can be well applied to nonlinear systems, with good performance in following reference trajectory as well as in disturbance-rejection. | 钟伟民 何国龙 皮道映 孙优贤 | 2005 | Chinese Journal of Chemical Engineering2005，13，3： | 12 |
| 3 | Rapid detection of the known SNPs of CYP2C9 using oligonucleotide microarray显示文摘AIM: Cytochrome P450 2C9 (CYP2C9) is a polymorphic enzyme responsible for the metabolism of a large number of dinically important drugs. Individuals with mutant enzymes may risk serious side effects under routine therapy with certain drugs metabolized by CYP2C9. In order to facilitate the detection of the known SNPs of CYP2C9, an allele-specific oligonucleotide (ASO) based microarray was made.METHODS: An oligonucleotide microarray was made to fadlitate the SNP (single nucleotide polymorphism) screening and was applied for the detection of CYP2C9 polymorphism in 62 high blood pressure (HBP) patients who received Irbesartan for treatment. Part of the genotyping results was confirmed by direct sequendng. And the relation between CYP2C9 polymorphism and therapeutic outcome of Irbesartan was statistically analyzed.RESULTS: Heterozygous alleles of CYP2C9*1/*3 were found in 7 out of 62 subjects. No mutant alleles of CYP2C9*2, *4 and *5 and no homozygous mutant alleles were detected.The 7 heterozygous CYP2C9*1/*3 and 13 random wild type DNA samples were subjected to direct sequencing with purified PCR products and same genotyping results were obtained with the 20 DNA samples. There was no significant difference in the odds of effectiveness of Irbesartan between the wild type (normal) group and CYP2C9*1/*3 (mutant)group (P>O.05).CONCLUSION: The oligonucleotide microarray made in this study is a reliable assay for detecting the CYP2C9 known alleles and the heterozygous CYP2C9*1/*3 has no significant effects on the therapeutic outcome of Irbesartan. | Si-Yuan Wen Hui Wang Ou-Jun Sun Sheng-Qi Wang Beijing Institute of Radiation Medicine,Beijing 100850,China | 2003 | World Journal of Gastroenterology2003，9，6： | 10 |
| 4 | Heterologous expression of human cytochrome P450 2E1 in HepG2 cell line显示文摘AIM: Human cytochrome P-450 2E1 (CYP2E1) takes part in the biotransformation of ethanol, acetone, many smallmolecule substrates and volatile anesthetics. CYP2E1 is involved in chemical activation of many carcinogens,procarcinogens, and toxicants. To assess the metabolic and toxicological characteristics of CYP2E1, we cloned CYP2E1 cDNA and established a HepG2 cell line stably expressing recombinant CYP 2E1.METHODS: Human CYP2E1 cDNA was amplified with reverse transcription-polymerase chain reaction (RT-PCR)from total RNAs extracted from human liver and cloned into pGEM-T vector. The cDNA segment was identified by DNA sequencing and subcloned into a mammalian expression vector pREP9. A transgenic cell line was established by transfecting the recombinant plasmid of pREP9-CYP2E1 to HepG2 cells. The expression of CYP2E1 mRNA was validated by RT-PCR. The enzyme activity of CYP2E1 catalyzing oxidation of 4-nitrophenol in postmitochondrial supernate (S9) fraction of the cells was determined by spectrophotometry. The metabolic activation of HepG2-CYP2E1 cells was assayed by N-nitrosodiethylamine (NDEA)cytotoxicity and micronucleus test.RESULTS: The cloned CYP2E1 cDNA segment was identical to that reported by Umeno et al(GenBank access No.J02843). HepG2-CYP2E1 cells expressed CYP2E1 mRNA and had 4-nitrophenol hydroxylase activity (0.162±0.025nmol.min-1.mg-1 S9 protein), which were undetectable in parent HepG2 cells. HepG2-CYP2E1 cells increased the cytotoxicity and micronucleus rate of NDEA in comparison with those of HepG2 cells.CONCLUSION: The cDNA of human CYP2E1 can be successfully cloned, and a cell line, HepG2-CYP2E1, which can efficiently express mRNA and has CYP2E1 activity, is established. The cell line is useful for testing the cytotoxicity,mutagenicity and metabolism of xenobiotics, which may possibly be activated or metabolized by CYP2E1. | Jian Zhuge Ye Luo Ying-Nian Yu Department of Pathophysiology,School of Medicine,Zhejiang University,Hangzhou 310031,Zhejiang Province,China | 2003 | World Journal of Gastroenterology2003，9，12： | 7 |
| 5 | Establishment of a transgenic cell line stably expressing human cytochrome P450 2C18 and identification of a CYP2C18 clone with exon 5 missing显示文摘AIM: The human cytochrome P-450 2C18(CYP2C18) hasbeen characterized. However, the protein has not beenpurified from liver and very little is known regarding thespecific substrate of CYP2C18. In order to study its enzymaticactivity for drug metabolism, the CYP2C18cDNA was clonedand a stable CHL cell line expressing recombinant CYP 2C18was established.METHODS: The human CYP2C18cDNA was amplified withreverse transcription-polymerase chain reaction (RT-PCR)from total RNAs extracted from human liver and cloned intopGEM-T vector. The cDNA segment was identified by DNAsequencing and subcloned into a mammalian expressionvector pREP9. A transgenic cell line was established bytransfecting the recombinant plasmid of pREPg-CYP2C18toChinese hamster lung (CHL) cell. The enzyme activity ofCYP2C18 catalyzing oxidation of tolbutamide tohydroxytolbutamide in postmitochondrial supernant(Sg)fraction of the cell was determined by high performanceliquid chromatography(HPLC).RESULTS: The amino acid sequence predicted from thecloned cDNA segment was identical to that of reported byRomkes et al(GenBank accession number: M61856,J05326).The S9 fraction of the established cell line metabolizestolbutamide to hydroxytolbutamide. Tolbutamide hydroxylaseactivity was found to be 0.509±0.052 μmol.min-1.g-1 S9protein or 8.82±0.90 mol.min-1.mol-1 CYP, but wasundetectable in parental CHL cell. In addition, we haveidentified a CYP2C18cDNA clone with exon 5 missing.CONCLUSION: The cDNA of human CYP2C18 wassuccessfully cloned and a cell line, CHL-CYP2C18, efficientlyexpressing the protein of CYP2C18, was established. Aspliced variant of CYP2C18 with exon 5 missing was identifiedin the cloning process. | JianZhu-GE Ying-NianYu | 2002 | World Journal of Gastroenterology2002，8，5： | 6 |
| 6 | 人细胞色素P450 2B6的异源表达及活性分析显示文摘目的获得有活性的人CYP2B6重组酶,用于进一步药物代谢研究。方法采用Bac-to-Bac杆状病毒介导的昆虫细胞表达系统进行人CYP2B6重组酶的表达,采用His抗体进行蛋白质印迹分析。安非他酮作为底物进行重组酶活性测定,高效液相色谱法测定其含量。结果蛋白质印迹分析检测到带有His标签的CYP2B6重组酶的表达,重组酶对安非他酮的Km值为(138±42)μmol.L-1,Vmax值为(676±21)pmol.min-1.mg-1蛋白。结论杆状病毒表达系统能成功表达有活性的CYP2B6重组酶,可用来进一步研究在药物代谢中的作用。 | 吕青 陈枢青 曾苏 | 2007 | 中国药学杂志2007，42，21： | 5 |
| 7 | Stable expression of human cytochrome P450 2D6*10 in HepG2 cells显示文摘AIM:Over 90% of drugs are metabolized by the cytochrome P-450 (CYP) family of liver isoenzymes.The most important enzymes are CYPIA2, 3A4,2C9/19,2D6 and 2E1.Although CYP2D6 accounts for<2% of the total CYP liver enzyme content,it mediates metabolism in almost 25% of drugs.In order to study its enzymatic activity for drug metabolism, its cDNA was cloned and a HepG2 cell line stably expressing CYP2D6 was established.METHODS:Human CYP2D6 cDNA was amplified with reverse transcription-polymerase chain reaction (RT-PCR) from total RNA extracted from human liver tissue and cloned into pGEM-T vector,cDNA segment was identified by DNA sequencing and subcloned into a mammalian expression vector pREP9.A cell line was established by transfecting the recombinant plasmid of pREP9-CYP2D6 to hepatoma HepG2 cells.Expression of mRNA was validated by RT-PCR.Enzyme activity of catalyzing dextromethorphan Odemethylation in postmitochondrial supernant (S9) fraction of the cells was determined by high performance liquid chromatography (HPLC).RESULTS:The cloned cDNA had 4 base differences, e.g.100 C→T, 336 T→C,408 C→G and 1 457 G→C,which resulted in P34S,and S486T amino acid substitutions, and two samesense mutations were 112F and 136V compared with that reported by Kimura et al (GenBank accession number: M33388).P34S and S486T amino acid substitutions were the characteristics of CYP2D6*10 allele.The relative activity of S9 fraction of HepG2-CYP2D6*10 metabolized detromethorphan O-demethylation was found to be 2.31±0.19nmol·min^-1·mg^-1 S9 protein (n=3),but was undetectable in parental HepG2 cells.CONCLUSION:cDNA of human CYP2D6*IOcan be successfully doned.A cell line,HepG2-CYP2D6*10,expressing CYP2D6*10 mRNA and having metabolic activity,has been established. | JianZhuge Ying-NianYu Xiao-DanWu | 2004 | World Journal of Gastroenterology2004，10，2： | 2 |
| 8 | 稳定表达人细胞色素P4501A2的HepG2细胞的建立及其代谢效应显示文摘目的 :建立稳定表达人细胞的色素 P4 5 0 1A2 (CYP1A2 )的 Hep G2细胞。方法 :将所克隆的野生型CYP1A2 c DNA从重组质粒 p GEM- CYP1A2中用 Kpn / Bam H 双酶切 ,并亚克隆到哺乳动物细胞表达载体p REP9中。再将重组质粒转化感受态大肠杆菌 Top10 ,用氨苄青霉素抗性筛选和限制酶谱鉴定。改良的磷酸钙介导的细胞转染法将重组质粒 p REP9- CYP1A2转染肝癌细胞 Hep G2 ,用 RT- PCR技术对转基因细胞的 CYP1A2m RNA表达作了分析 ,并用 MTT法比较转基因细胞对黄曲霉素 B1(AFB1)细胞毒敏感试验。结果 :与 Hep G2细胞相比 ,Hep G2 - CYP1A2转基因细胞表达 CYP1A2 m RNA,能增强 AFB1的细胞毒作用。结论 :建立了稳定表达CYP1A2的转基因细胞系 ,可用于由 CYP1A2参与的毒理学与药物代谢研究。 | 诸葛坚 叶森 余应年 | 2003 | 浙江大学学报(医学版)2003，32，5： | 0 |
| 9 | Enzyme activity analysis of CYP2C18 with exon 5 skipped显示文摘AIM: To study the enzyme activity of CYP2C 18 variant with exon 5 skipped. METHODS: A full length CYP2C18 cDNA X1 and an exon 5 skipped variant CYP2C18 X2 were separately subcloned into mammalian expression vector pREP9 to transfect HepG2 cells. The expression of CYP2C18 mRNA in transgenic cells and human liver tissues were determined by RT-PCR. The enzyme activity of CYP2C 18 to oxidate tolbutamide in postmitochondrial supernate (S9) fraction was determined by HPLC. The cytotoxicity of ifosfamide to transgenic cells was evaluated by MTT test. RESULTS: HepG2-CYP2C 18 X 1 cells showed strong expression of the full length CYP2C 18 mRNA. On the other hand, HepG2-CYP2C 18 X2 cells had only infinitesimal expression of the exon-skipped CYP2C 18 as well as the full length CYP2C 18, while non-transfected HepG2 cell only demonstrated an infinitesimal expression of the full length CYP2C 18. The expression of CYP2C 18 exons 2 to 7 was also analyzed by RT-PCR in 7 extratumoral liver tissues. Among them, 3 samples expressed only wild type mRNA, whereas 4 samples expressed both wild type and alternative splicing products. The tolbutamide hydroxylase activity of CYP2C 18 was tested, and it was shown that HepG2-2C 18 X 1 cells had higher enzyme activity than those of HepG2-2C18 X2 and HepG2 cells. The relative survival of HepG2-CYP2C 18 X 1 cells was lower than that of HepG2 cells with 1, 2, and 4 mmol/L ifosfamide treatments. In contrast, the relative survival of HepG2-CYP2C 18 X2 cell was the same as that of HepG2 cell in 0.5 and 1 mmol/L of ifosfamide, but lower than that of HepG2 cell in 2 and 4 mmol/L of ifosfamide. CONCLUSION: CYP2C18 X 1 could metabolize tolbutamide and ifosfamide efficiently. The exon 5-skipped CYP2C18 X2 could not metabolize tolbutamide, and could not metabolize ifosfamide effectively at low concentrations. | JianZHU-GE Ying-nianYU | 2004 | Acta Pharmacologica Sinica2004，25，8： | 0 |
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