转染E1B55K基因提高Hep2细胞包装肠腺病毒Ad41的能力

人F组腺病毒Ad40、Ad41难以在体外培养的细胞中传代,被称为难养腺病毒(Fastidious adenovirus).本研究观察了在Hep2细胞表达Ad41 E1B55K基因对Ad41复制的促进作用.从Ad41阳性粪便标本中用PCR的方法获得E1B55K基因,构建真核表达载体,转染Hep2细胞,筛选单克隆,用RT-PCR检测了E1B55K基因的表达.用引起293细胞完全CPE比较产毒量的方法对所得细胞克隆进行初步筛选,获得一株产毒相对较强的细胞Hep2-E1B#4.与对照细胞Hep2、Hep2-DNA3相比,等量Ad41接种Hep2-E1B#4产生的细胞病变效应(CPE)程度明显加深.用免疫细胞化学的方法测定产毒的感染滴度,等量Ad41接种后,Hep2-E1B#4产生的子代腺病毒滴度大于对照的9倍;半定量PCR测得Hep2-E1B#4子代病毒基因组拷贝数约为对照细胞的4倍.结果说明转染E1B55K基因促进了Ad41在Hep2细胞的复制,获得的Hep2-E1B#4细胞株可用于Ad41的分离、培养和体外扩增.     

蛋白质组学技术在研究AdIL-24抗癌机制中的应用

目的：探讨蛋白质组学技术在研究AdIL-24抗宫颈癌CaSki细胞作用机制的应用价值。方法：前期研究已成功构建AdIL-24,可抑制宫颈癌CaSki细胞生长,促进凋亡。在此基础上,通过双向凝胶电泳分离AdIL-24处理前后细胞总蛋白,并对胶条（pH3-10NL、pH4-7）、SDS-PAGE浓度（10％、12％）、电泳时间（6h、7h）进行优化,PDQuest图像分析,MALDI-TOF质谱鉴定,经Mascot、MS-fit软件查询SWISS-PORT数据库鉴定差异蛋白。结果：获得分辨率高、重复性好的CaSki细胞双向电泳图谱,质谱鉴定的差异蛋白点经Mascot、MS-fit软件搜索到同一种蛋白质。结论：已建立的蛋白质组学技术,为进一步研究AdIL-24的抑癌机制奠定基础。     

Synthesis and in-vitro biological activity of macrocyclic urea Chk1 inhibitors

A variety of macrocyclic urea compounds were prepared as potent Chk1 inhibitors by modifying the C5 position of the benzene ring of the macrocyclic urea with ether moieties, aliphatic carbon chains, amide and halides. Enzymatic activity less than 20nM was observed in 29 of 40 compounds. Compounds 14, 46d, and 48j provided the best overall results in the cellular assays as they abrogated doxorubicin-induced cell cycle arrest (IC(50)=3.31, 3.08, and 3.13microM) and enhanced doxorubicin cytotoxicity (IC(50)=0.54, 1.27, and 0.96microM) while displaying no single agent activity, respectively.     

Discovery of tetralin ureas as potent melanin concentrating hormone 1 receptor antagonists

Melanin concentrating hormone (MCH) plays an important role in the regulation of food intake and energy balance in mammals. MCH-1 receptor (MCH1R) deficient mice are lean and resistant to diet-induced obesity. As such, MCH1R antagonists are believed to have potential as possible treatments for obesity. The discovery of a novel class of tetralin ureas as potent MCH1R antagonists is described herein.     

Biological evaluation of de-O-sulfonated analogs of salacinol, the role of sulfate anion in the side chain on the alpha-glucosidase inhibitory activity

De-O-sulfonated analogs (10a, Y(-)=CH(3)OSO(3) and 10b, Y(-)=Cl) of salacinol, a naturally occurring glycosidase inhibitor, and its diastereomer (12a, Y(-)=CH(3)OSO(3)) with L-thiosugar moiety (1,4-dideoxy-1,4-epithio-L-arabinitol) were prepared. Their inhibitory activities against intestinal maltase and sucrase were examined and compared with those of the parent alpha-glycosidase inhibitor, salacinol (1a). Compounds 10a and 10b showed a potent inhibitory activity equal to that of 1a against both enzymes, although 12a was a weak inhibitor against sucrase and maltase. These results indicated that the O-sulfonate anion moiety of 1a is not essential for the inhibitory activity.     

Identification of secondary structure elements in intermediate-resolution density maps

An increasing number of structural studies of large macromolecular complexes, both in X-ray crystallography and cryo-electron microscopy, have resulted in intermediate-resolution (5-10 A) density maps. Despite being limited in resolution, significant structural and functional information may be extractable from these maps. To aid in the analysis and annotation of these complexes, we have developed SSEhunter, a tool for the quantitative detection of alpha helices and beta sheets. Based on density skeletonization, local geometry calculations, and a template-based search, SSEhunter has been tested and validated on a variety of simulated and authentic subnanometer-resolution density maps. The result is a robust, user-friendly approach that allows users to quickly visualize, assess, and annotate intermediate-resolution density maps. Beyond secondary structure element identification, the skeletonization algorithm in SSEhunter provides secondary structure topology, which is potentially useful in leading to structural models of individual molecular components directly from the density.     

1,4-Dihydroindeno[1,2-c]pyrazoles as potent checkpoint kinase 1 inhibitors: extended exploration on phenyl ring substitutions and preliminary ADME/PK studies

A study on substitutions at the four open positions on the phenyl ring of the 1,4-dihydroindeno[1,2-c]pyrazoles as potent CHK-1 inhibitors is described. Bis-substitution at both the 6- and 7-positions led to inhibitors with IC(50) values below 0.3nM. The compound with the best overall activities (36) was able to potentiate the anti-proliferative effect of doxorubicin in HeLa cells by at least 47-fold. Physicochemical, metabolic, and pharmacokinetic properties of selected inhibitors are also disclosed.     

Synthesis and cytotoxicity of novel fatty acid-nucleoside conjugates

N(3)-Hydroxyethyltegafur (3) was synthesized in 91.0% yield under a new condition. A series of novel fatty acid esters of 3 were synthesized. These fatty acid-nucleoside conjugates have shown cytotoxicities against Ec9706 cells and A549 cells, and the structure activity relationship was discussed.     

Dumbbell-shaped circular oligonucleotides as inhibitors of human topoisomerase I

A dumbbell-shaped circular oligonucleotide containing topoisomerase I-binding sites and two mismatched base pairs in its sequence has been designed and synthesized. Our further studies demonstrate that this particularly designed oligonucleotide displays an IC(50) value of 9 nM in its inhibition on the activity of human topoisomerase I, a magnitude smaller than that of camptothecin, an anticancer drug currently in clinical use.     

Size-fractionated chlorophyll a and primary productivity in the Chukchi Sea and its northern Chukchi Plateau

Investigations on chlorophyll a and primary productivity were carried out in the Chukchi Sea and its northern Chukchi Plateau during the 2^nd Chinese National Arctic Research Expedition in the summer of 2003. The results showed that chlorophyll a concentrations were 0.009–30.390 μg/dm³ at the surveyed waters; the surface chlorophyll a concentrations were 0.050–4.644 μg/dm³ and the average value was (0.875±0.981) μg/dm³ in the surveyed area. In the Chukchi Sea Shelf, chlorophyll a concentrations at the depth from 10 m to bottom were higher than that in the surface water, and the concentrations were lower at the depth below 75 m in the Chukchi Plateau. Chlorophyll a concentrations descended in 3 sequential samplings on Transect R, with average values of (2.564±1.496) μg/dm³, (1.329±0.882) μg/dm³ and (0.965±0.623) μg/dm³, respectively. The potential primary productivity ((2.305± 1.493) mgC/(m³·h)) in the Chukchi Sea was higher than that ((0.527±0.374) mgC/(m³·h)) in the Chukchi Plateau. The results of the size-fractionated chlorophyll a and primary productivity showed that microplankton accounted for the majority of the total chlorophyll a (63.13%) and primary productivity (65.16%) at the survey stations. The contributions of the nanoplankton and picoplankton to the total chlorophyll a and primary productivity were roughly the same.