金子——DNA试验

请设想,如果医生能用1个简单的变色试验,在几秒钟内诊断出病人是否患癌或者基因功能不良,或者病原体感染,那该多好!可是,如果这种试验需要耗费金子,那么,医生会感到,该试验是否太贵了?事实上,这样的试验即将成为可能,每次试验的成本,不需10美分,因为1盎司的金子,足供几千次试验之用.关键在于:这金子要变成纳米球的形式使用.

应用DNA彗星试验技术检测辐照鸡肉的研究

[目的]研究DNA彗星试验技术在检测辐照鸡肉方面的应用。[方法]新鲜鸡肉,于-20℃冷冻保存7天后,分别用0kGy、1kGy、3kGy、5kGy和7kGy不同剂量进行辐照处理,解冻后分离细胞,用彗星试验测定其DNA损伤,并分析剂量反应关系。[结果]经0kGy、1kGy、3kGy、5kGy和7kGy辐照的鸡肉细胞平均尾长和尾相分别为1.02μm、2.19μm、2.88μm、3.53μm和4.11μm以及0.38、0.75、1.05、1.60和2.03。经统计学分析,辐照与未辐照鸡肉细胞彗星电泳图尾长与尾相存在显著性差异,并存在一定的剂量反应关系。[结论]彗星试验可检测由于辐照对于鸡肉组织细胞的DNA损伤,并可作为筛选技术判断该鸡肉是否经过辐照处理。

Genentech公司着手于抗胆囊纤维变性的DNA酶试验

Genentech 公司继今年五月向食品和药物管理局(FDA)申请 DNA 酶的新药试用研究以后,又宣布它希望在以后的几月里着手于人类临床试验.DNA 酶是一种粘液溶解性酶,公司希望能将其制成治疗胆囊纤维变性的独特药物.胆囊纤维变性是一种青年人中普遍的致命性遗传病(美国患者约3万)。它通常使患者死于由重复性肺部感染引起的呼吸障碍.

海洋真菌提取物损伤大肠杆菌DNA活性的筛选及活性菌株研究

从海洋微生物中筛选抗菌、抗肿瘤物质是海洋药物研究的热点之一,而筛选模型在研究中起着重要作用。建立了可用于抗菌及潜在抗肿瘤活性物质筛选的大肠杆菌差异性DNA修复试验模型,并运用该模型对海洋共附生真菌的提取物进行了筛选。结果显示,5株海洋真菌的提取物具有较强的选择性抑制DNA损伤修复基因缺陷型大肠杆菌的活性,可能具有DNA损伤作用。对这5种活性真菌进行了分子生物学鉴定,而且薄层色谱(TLC)和高效液相色谱(HPLC)-活性追踪显示这些菌株可产生较多样化的活性物质。

某市饮用水原水、自来水及经不同浓度活性炭处理后自来水对大鼠原代肝细胞DNA损伤修复的影响研究

为研究不同浊度的原水、自来水、加入不同浓度的活性炭处理后的自来水水样有机提取物的致突变性 ,进行了大鼠肝细胞程序外DNA合成 (UDS)试验研究。结果表明 :自来水、加活性炭 5、10、15mg L处理组以及各种浊度的原水水样有机提取物UDS试验均呈阳性结果 ,且每组随加入水样体积增高而出现CPM值上升。水样致突变性随浊度升高而增强 ,自来水致突变性高于原水 ,自来水加活性炭 2 0mg L处理后未检出程序外DNA合成。通过加强混凝沉淀、过滤和活性炭吸附等常规水处理工艺 。

Genetic Polymorphism in GDF8 Region of HU Sheep Based on Microsatellite DNA

[ Objective ] This study was to analyze the genetic polymorphism in GDF8 Region of HU sheep. [Method] Four microsatellite loci including BMS1591, TEXAN-2, FCB128 and BM81124 mapped on GDF8 region of chromosome No. 2 of sheep that may be correlated with growth performance were chosen to detect the molecular genetics foundation of growth performance of Hu sheep. [ Result] Four microsatellite loci detected were high in heterozygosity, more in effective alleles number and rich in polymorphic information, all the three indices passed through the high polymorphic level （PIC 〉0.5）. [ Conclusion ] The four microsatellite loci detected could be used to estimate the genetic polymorphism of growth performance of Hu sheep.

脱氧雪腐镰刀菌烯醇(CBD_1)的毒性探讨:CBD_1对DNA合成的抑制作用观察

为了评价 CBD1的诱变和/或致癌作用,用3（?）-胸腺嘧啶核苷研究 CBD1对雄性小鼠睾丸 DNA合成的影（?）。实验结果表明 CBD1抑制睾丸 DNA 合成。CBD1剂量越大,睾丸 DNA 合成抑制越明显,具有剂量——效应关系。结合 Ames 试验的阳性结果,可初步检测CBD1的诱变和/或致癌作用。

Optimization of PCR Reaction System for Random Single-strand DNA Pool in SELEX Technology

[Objective] This study aimed to optimize the PCR amplification conditions for random ssDNA pool in SELEX technology. [Method] L16（45） orthogonal experimental design was adopted for optimization of five important factors affecting PCR reaction system for random single-stranded DNA pool including Mg2＋ concentration, dNTP concentration, amount of Taq DNA polymerase, primer concentration and amount of random single-stranded DNA pool at four levels. Meanwhile, the annealing temperature and number of PCR reaction cycles were optimized to establish the optimal reaction system and PCR procedure. [Result] The optimal combination of PCR reaction system for random ssDNA pool was obtained, with a total system volume of 20 μl containing 2.0 μl of 10 × Buffer, 0.5 ng of random ssDNA pool, 2.5 mmol/L Mg2＋, 0.25 mmol/L dNTP Mixture, 0.6 μmol/L upstream and downstream primers and 1.5 U of Taq DNA polymerase; the optimal annealing temperature was 68 ℃ and the optimal number of cycles was 12. Under the above conditions, clear and stable bands with high specificity for random ssDNA pool were amplified. [Conclusion] This study laid the foundation for selection of parameters with higher specificity in SELEX technology.

改进的CTAB法提取高寒植物长鞭红景天基因组DNA的研究

根据自己抽提高寒植物基因组DNA的实际经验,改进了Clark利用CTAB提取植物基因组DNA的方法,在试验过程中发现,通过在研磨材料时加入液氮、剪去端部的吸头转移含有DNA的溶液,并且将加入RNaseA消化RNA的步骤,结果证明改良的CTAB法得到的长鞭红景天基因组DNA浓度和纯度较高,且无无蛋白质和RNA等杂质影响。

DNA Damage （Comet Assay） as Biomarker of Cd Exposure in Marine Seed Scallops Mizuhopecten Yessoensis Age 1 Year

Cadmium-induced DNA degradation in gill cells of the scallop Mizuhopectenyessoensis was assessed using the comet assay （single-cell gel electrophoresis）. Accumulation of highly toxic cadmium in the gill cells of bivalve is accompanied by the damage of the cell genome revealed as DNA migration in the comet assay. The main mechanisms of Cd effects on the integrity of the DNA structure are discussed.

Study on DNA Immunization by Recombinants Encoding Japanese Encephalitis Virus prME and E Proteins

To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) genes, two recombinants (pJME and pJE) containing JEV prME and E genes fused with FLAG were constructed and then transfected into HepG2 and COS-1 cells by liposome fusion. The expression feature of FLAG-prME (about 72 kDa) and FLAG-E (about 54 kDa) proteins in transfected cells were analyzed by Western blot and two antibody systems (anti-FLAG and anti-E). BALB/c mice were immunized with 100 μg of two kinds of recombinants by intramuscular injection, and JEV JaGAr-01 strains (10 5 PFU/100 μl)were given to BALB/c mice by intraperioneal injection 3 wk after twice DNA immunization by a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. 80% plaque reduction neutralization test was performed to titrate neutralization antibody before and after viral challenge. It was found that the expression of proteins associated with pJME and pJE was determined in transfected cells with anti-FLAG and a new protein of 11 kDa was detected in HepG2 and COS-1 cells transfected with pJME. Only E (53 kDa) protein was identified as transfected with pJME using anti-E. Higher level of neutralization antibodies and the efficacy of protective immunity were induced with pJME immunization, and were similar to those induced by inactivated Japanese encephalitis vaccine, but were better than those induced with pJE. It concludes that the expression level from prM to E proteins of JEV is different in vitro, and the in vitro expression efficiency of pJME was better than that of pJE. FLAG-prME protein expressed by pJME could be cleaved by peptidase from host. The efficacy of DNA immunization is correlated to the expression characterization of related proteins expressed in vitro.

基因工程药物的安全性及其伦理问题

随着重组DNA技术的不断完善 ,基因工程药物的研制和利用日益增多。与此同时 ,基因工程药物的安全性及其伦理学问题也与日俱增。其主要体现在 :重组DNA试验及大规模产业化过程中病原体的逃逸及其对人体的污染、基因工程药物的安全性、基因治疗的安全性及其伦理问题、基因工程药物与生态伦理及社会伦理、基因工程药物的研究与国际安全、基因工程药物对生物进化的影响等。本文在概述了基因工程药物现状和存在的安全性及伦理问题的基础上 ,提出了与之相应的对策 ,并对所提出的对策进行了初步的理论探讨。

乙脑病毒prME与E蛋白编码基因重组构建的DNA免疫试验研究

目的 研究乙脑病毒prME、E蛋白的体外表达特点 ,比较不同重组质粒所进行的DNA免疫效率。方法 分别将乙脑病毒 (JaGAr 0 1株 )prME、E蛋白编码基因 (2 0 0 1bp、15 0 0bp)构建于融合FLAG标记基因的真核表达载体pcDNA(FLAG) 3上 (pJME、pJE) ,脂质体法将二重组质粒转染于HepG2及COS 1细胞系 ;采用不同抗体系统 (anti FLAG、anti E) ,经Westernblot法检测乙脑病毒prME[相对分子质量 (Mr)约 72× 10 3]与E(Mr 约 5 4× 10 3)蛋白表达水平 ;将质粒肌注BALB c鼠 ,二次免疫后 3周 ,腹腔注射乙脑病毒 (10 5PFU 10 0 μl)作为病毒攻击并观察 2 1d。 80 %空斑减少中和实验法检测中和抗体滴度变化。结果 anti FLAG可检测到由质粒pJME、pJE编码的相应蛋白产物在转染细胞内表达 ,同时在pJME转染的细胞内检测到一个新的 11× 10 3的低Mr 蛋白。anti E仅在pJME转染的细胞内检测到E蛋白。肌注pJME可产生高水平中和抗体滴度以及诱导有效的保护性免疫 ,效果等同于普通灭活JE疫苗 ,但优于pJE。结论 pJME的体外表达水平优于pJE。DNA免疫实验结果与prME。

一种新的快速简便的抗肿瘤药物筛选模型

本研究利用 DNA修复缺陷的大肠埃希氏菌 343/ 5 91和正常的大肠埃希氏菌 343/ 6 36的差异性DNA修复特性 ,建立了液体悬浮法和琼脂固体筛选方法 ,用于抗肿瘤药物的筛选。这两种方法简便易行 ,其中琼脂固体筛选方法与抗生素生物鉴定杯碟法一样简单 ,适合于大量筛选各种来源的抗肿瘤药物。

甲基叔丁基醚的遗传毒性研究

[目的 ]探讨国产甲基叔丁基醚 (MTBE)的遗传毒性。 [方法 ]应用单细胞凝胶电泳试验、DNA交联试验和程序外DNA合成试验 ,测试MTBE对大鼠肺Ⅱ型细胞和肝细胞的遗传毒性。 [结果 ]MTBE可引起大鼠肺Ⅱ型细胞和肝细胞的DNA链断裂及程序外DNA合成的增加 ,不引起小牛胸腺DNA、大鼠肺Ⅱ型细胞DNA和肝细胞DNA交联。 [结论

饮用水中二溴乙酸遗传毒性研究

二溴乙酸 (DBA)是饮用水氯化消毒副产物中的一种 ,属于氯乙酸类 ,臭氧消毒也可产生。本次试验采用Ames试验、程序外DNA合成 (UDS)试验、小鼠体内微核试验、NIH3T3细胞微核试验对其遗传毒性进行了研究。在Ames试验中 ,TA10 0菌株在加与不加S9的情况下均表现出致突变性。在大鼠肝细胞UDS试验中 ,DBA表现出明显的DNA损伤作用 ,导致程序外合成增加。在小鼠体内微核试验中 ,DBA在一定剂量范围内可引起染色体损伤。在NIH3T3细胞微核试验中 ,DBA可诱导细胞微核数增加。上述结果表示 ,DBA具有明确的DNA损伤作用。