INHIBITED NEOPLASTIC PHENOTYPE BY THE c-Ha-ras ANTISENSE RNA

A 2.0 kb fragment DNA plasmid which expresses antisense to the upstream first exon of c-Ha-ras oncogene was transfected into Ha-ras transformed cell lines, GCM-3T3 and REF-4.3. The transfection leads to the inhibition of malignant behaviour, shown by decreasing of growth speed, colony forming ability on soft agar, tumorigenicity in nude mice and increasing ot differentiation degree. In GCM-3T3 cells the lung metastasis frequency became much less (from 60% to 12.5%) after the transfection and the expression of ras oncogene product, and p21 protein was obviously decreased in the transfected cells. This work has first shown the inhibitory effect of antisense RNA on neoplastic behaviour in China.     

人参叶全长cDNA文库的构建及部分克隆的序列分析

提取人参叶组织总RNA,用SMART[TM]cDNA文库构建试剂盒所示方法,以λTriplEx2为载体构建了人参叶cDNA文库.经测定该文库初始滴度为1.2×106pfu/mL,扩增后滴度为7.6×1010pfu/mL,重组率为86%.插入片段长度为0.3~2.5 kb.随机挑取16个cDNA克隆体进行测序分析,结果显示16个克隆体中有8个同GenBank中登录的人参皂苷合成相关基因GBR5,GBR3和GBR1高度同源,8个为新的基因序列.人参cDNA文库的建立为克隆人参中有明确功能的特异基因以及克隆和研究人参中的新基因奠定了必要的物质基础.     

EXPRESSION OF A PARTIAL SYNTHETIC HUMAN TNF cDNA IN E. coli

A recombinant human tumour necrosis factor (rhTNF) cDNA was constructed. The TNF gene was isolated from a human genomic gene library. There are four exons in the TNF gene. The fourth exou codes for 140 amino acids of the TNF matured protein which is composed of 157 amino acids. A major portion of the fourth exon was isolated and then ligated to a synthesized DNA fragment coding for the remaining amino acids. The partial synthetic hTNF (rhTNF) cDNA thus generated was subcloned into a vector and successfully expressed in E. coli. 5-1 fer1entator was used to produce rhTNF. About 20g (wet weight) of bacterial pellet per liter medium and 106—10~7 units of cytotoxicity to L929 cells per milliliter medium were obtained. rhTNF was purified by HPLC and dried with a freeze dryer, rhTNF with a purity of about 95% in the form of white powder was obtained. The sequence of ten amino acids at the amino terminus of the rhTNF was determined. The result showed that it was identical with that of the natural human TNF.     

Construction and Characterization of a cDNA Expression Library for the North American Ginseng Root Tissues

The root of Panax ginseng plant undergoes a specific developmental process to become a biosynthesis and accumulation tissue for ginsenosides. To identify and analyze genes involved in the biosynthesis of ginsenoside, we constructed and characterized a full-length cDNA library for 6-year-old North American ginseng. The titer of primary cDNA library is 1.2 × 10^6 pfu/mL, the titer of amplified library is 2. 6 × 10^10 pfu/mL and the rate of recombinant is above 86%. The insert size ranges from 0. 3 to 2.0 kb. Sequencing results show that 18 of 58 genes are high homologous to the genes （GBRS, GBR3 and GBR1 ） known in GenBank, which are involved in biosynthesis of ginsenoside in North American ginseng plant; 16 of 58 genes are novel genes. The full-length cDNA library of North American ginseng root tissues is essential for the cloning of genes known and it is also an initial key for the screening and cloning of new genes.     

COPOLYMERIZATION OF PROPYLENE WITH HINDERED PIPERIDINE MONOMER OVER A HIGH ACTIVITY SUPPORTED ZIEGLER-NATTA CATALYST

Copolymerization of propylene and hindered piperidine monomers was carried out overa high activity supported Ziegler-Natta catalyst, using Al(C_2H_5)_3 as cocatalyst. Factorswhich affect the copolymerization were studied. The copolymers exhibited high light sta-bility without adding extra light stabilizers. A self-stabilized polypropylene was prepared.     

SYNTHESIS OF POLYCATECHOL WITH ELECTROCHEMICAL ACTIVITY AND ITS PROPERTIES

The electrochemical polymerization of catechol on platinum has been carried out using repeated potential cyclingbetween-0.2 and 1.1 V (versus SCE). The electrolytic solution consisted of 0.2 mol dm~(-3) catechol, 0.5 mol dm~(-3) NaCl and0.1 mol dm~(-3) Na_2HPO_4 with pH 8.72. Catechol can not be polymerized at pH≥10.12. Polycatechol has an electrochemicalactivity at pH≤4. The anodic and cathodic peak potentials of polycatechol shift towards more negative values as the pH ofthe solution increases from 1 to 4. The electrochemical activity of polycatechol hardly changes in this pH region, but itdecreases slowly with time. This is caused by oxygen in air, which leads to an irreversible oxidation of polycatechol. Thisproperty is favorable for protecting metals from corrosion. Raman and FTIR spectra of polycatechol and catechol are quitedifferent. AFM images of polycatechol films provide evidence that the image of the oxidized state of polycatechol ismarkedly different from that of the reduced one. This difference is caused by doping and dedoping of polycatechol.     

淇河鲫生长激素(growth hormone)全长cDNA的克隆与序列分析

用RT-PCR法和3′、5′RACE(Rapid amplification of cDNAends)法从淇河鲫脑垂体RNA克隆出生长激素(Growth hormone,GH)cDNA.此cDNA全长1191 nt(含Poly(A)14 nt),其5′端非编码区长55 nt、阅读框(Open readingframe,OAF)长633 nt,3′端非编码区长503 nt.其推导的GH由210个氨基酸组成,其中氮端前22个氨基酸为信号肽部分.氨基酸序列比较表明:淇河鲫与同目的鲫鱼、鲤鱼、团头鲂和斑马鱼的同源性分别为98.6%,96.2%,91.5%和88.6%;与不同目鱼的胡子鲇和鳗鲡的同源性分别为74.6%和49.5%;与哺乳类的家鼠和人等的同源性低于40%.     

TREATMENT ACTIVITY AND NURSING VALUES OF A HETEROCYCLIC COMPOUND COMBINED WITH ASPIRIN ON TRAUMATIC ARTHRITIS

Journal of Structural Chemistry - Heterocyclic compound 2-(3-(ethoxycarbonyl)-4-isobutoxyphenyl)-4-methylthiazole-5-carboxylic acid (1) designed using...     

PHOTOBIOLOGICAL ACTIVITY OF 3,4''-DIMETHYL-8-METHOXYPSORALEN, A LINEAR FUROCOUMARIN WITH UNUSUAL DNA-BINDING PROPERTIES

The furocoumarin derivative 3,4'-dimethyl-8-methoxypsoralen (DMe-8-MOP) exhibits remarkable antiproliferative activity, but is devoid of skin phototoxicity. To gain insight into this peculiar behaviour we investigated non-covalent and covalent binding of DMe-8-MOP to calf thymus DNA, along with DNA-synthesis inhibition and mutagenic activity. The non-covalent interaction of DMe-8-MOP with the nucleic acid is quite poor as shown by equilibrium dialysis, spectroscopic, chiroptical and hydrodynamic techniques. However, it exhibits relevant photobinding ability to DNA using both isolated nucleic acid samples and cellular systems. Unlike the large majority of congeners, DMe-8-MOP undergoes predominantly photochemical monoaddition to the double helical polynucleotide. Upon examination of the products obtained by enzymatic hydrolysis of DMe-8-MOP photomodified DNA, the formation of an unusual furan side adduct is proposed, which could account for the peculiar photochemical and photobiological properties of the 3,4'-dimethyl furocoumarin derivative.     

丙氨酸－N－荒酸镍与稀土多核配合物的合成、表征和抗癌、抑菌活性研究

本文报道了稀土与丙氨酸－Ｎ－荒酸镍［Ｈ２ＮｉＬ２］多核配合物的合成和表征。通过元素分析确定配合物的组成为ＲＥ２（ＮｉＬ２）３·ｘＨ２Ｏ（ＲＥ＝Ｌａ、Ｎｄ、Ｓｍ－Ｅｒ、Ｙｂ；ｘ＝１、４、８），并研究了配合物的摩尔电导、红外光谱和核磁共振氢谱。配合物体外抗癌活性及抑菌活性的测定结果表明，丙氨酸－Ｎ－荒酸镍及其稀土多核配合物均具一定的抗癌、抑菌活性。     

Gene Amplification and High-Level Expression of Human Pro-Urokinase cDNA in Chinese Hamster Ovary Cells

Human Pro-Urokinase (Pro-UK) is expressed in CHO-DHFR- cells at high efficiency by co-transfecting the mouse dhfr gene and Pro-UK cDNA under the control of the SV40 late promoter. After gene co-amplification, the product level could reach 2-3 μg/106 cells/24 h in the presence of 5×10-6 mol/ L MTX, and the levels can be further raised to 3. 5-4 μg/106 cells/24 h by PMA superinduction. The copy number of Pro-UK cDNA in the genomes of host cells is about 200-300 copies/cell. The Western blot analysis shows that the recombinant Pro-UK has similar molecular weight to its natural counterpart, and also the amidolytic activity of the product is determined by S-2444 assay.     

A PULSED LASER AND PULSE RADIOLYSIS STUDY OF AMPHIPHILIC CHLOROPHYLL DERIVATIVES WITH PDT ACTIVITY TOWARD MALIGNANT MELANOMA

Two amphiphilic derivatives of chlorophyll, which have high potential as photodynamic therapy sensitizers for malignant melanoma have been investigated by a combination of laser flash photolysis and pulse radiolysis. It is shown that direct excitation of monomeric forms of these molecules in both hydrophilic and hydrophobic environments produces significant yields of the corresponding triplet states, which have been characterized in terms of spectral and kinetic parameters. In both environments, scavenging of the triplets by oxygen produces singlet oxygen, O₂(^lΔ₈), with essentially unit efficiency as evidenced by time-resolved IR luminescence measurements.     

SYNTHESIS OF PSEUDO-DISACCHARIDE ANALOGUES OF LIPID A: HAPTENS FOR THE GENERATION OF ANTIBODIES WITH GLYCOSIDASE ACTIVITY TOWARDS LIPID A

In order to develop a generic treatment of sepsis caused by infections with Gram-negative bacteria, a series of pseudo-disaccharide analogues of lipid A (1–5) was synthesized. These adducts not only harbor a 2-acylaminodideoxynojirimycin unit mimicking the transition state of the glycosidic hydrolysis, but also a 2-N, 3-O-diacylated glucosamine moiety capable of generating catalytic antibodies with more selective glycosidase properties towards lipid A.     

八面体配合物分子的旋光性和构型

在极化度多级圆球不对称模型(该模型运用于含一个或二个不对称碳的有机化合物)和对称性规则的基础上,我们提出了某些规则和八面体配合物的八区律。利用这些规则和规律,八面体配合物的分子构型可以方便的与它们的旋光方向联系起来。     

基于二氧化硅微颗粒促细胞增殖效应的基因转染新方法

报道了二氧化硅微颗粒(SiMPs)的促细胞增殖效应, 并基于该效应发展了一种以二氧化硅微颗粒为转染伴侣的基因转染新方法, 采用MTT实验证明了二氧化硅微颗粒具有促细胞增殖效应, 并以绿色荧光蛋白表达载体质粒pEGFP为报告基因, COS-7细胞为靶细胞, 在多聚-L-赖氨酸介导的基因转染中, 利用二氧化硅微颗粒的促细胞增殖效应, 加入二氧化硅微颗粒作为转染伴侣开展基因转染实验, 获得了显著增强的基因转染效率, 相比于未加入二氧化硅微颗粒为转染伴侣的基因转染方法, 该方法的转染效率提高到5倍多. 利用二氧化硅微颗粒的促细胞增殖效应, 以其作为转染伴侣的基因转染新方法不仅为相关研究提供了一种高效简便的基因转染新方法, 而且也为基因转染效率的提高提供了新的思路.     

Cholera toxin-induced modulation of gene expression: elucidation via cDNA microarray for rational cell-based sensor design

Cell-based biosensors utilize functional changes in cellular response to identify the biological threats in a physiological relevant manner. Cell-based sensors have been used for a wide array of applications including toxicological assessment and drug-screening. In this paper, we utilize DNA arrays to identify differential gene expression events induced by toxin exposure for the purpose of developing a reporter gene assay system compatible with insertion into a cell-based sensor platform. HT29, an intestine epithelial cell line, was used as a cell model to study the cholera toxin (CT)-induced host cell modulation using DNA array analysis. A false positive model was generated from analysis of housekeeping genes in untreated control experiments to characterize our system and to minimize the number of false positives in the data. Threshold probability scores (−3.72), which gives <0.02% false positives for up/down regulation from the false positive model, were used to identify 73 and 25 known genes/expression tag sequences (ESTs) that were up- and down-regulated, respectively, in cells exposed 23 nM of CT. Using quantitative multiplex PCR assay, the gene expression levels for several genes shown to be modulated according to the microarray experiments, such as apolipoprotein D (Apol D), E-cadherin, and cyclin A2, were confirmed. The differential expression of genes encoding cytochrome P450, glutathione transferase (GST), and MGAT2 were noteworthy and consistent with previous studies. Our study provides an approach to analyze cDNA microarray data with defined false positive rates. The utility of cDNA microarray information for the design of cell-based sensor using a reporter gene approach is discussed.