S-DABO 类衍生物及AZT-氟喹喏酮类偶联物体外抗HIV 活性及机制研究

本论文由2 个相对独立的部分组成: S-DABO 类衍生物体外抗HIV 活性及 其机制研究和AZT－氟喹喏酮类偶联物体外抗HIV-1 活性及其机制研究。 HIV 逆转录酶抑制剂一直是抗HIV 药物研发的热点。该类抑制剂靶定在病 毒复制周期早期，为HAART 疗法提供了很多新的药物组合。目前FDA 批准上 市的逆转录酶抑制剂虽然有很多，但由于较严重的毒副作用、HIV 病毒易变异、 耐药性的出现等问题还需要开发更多的新的逆转录酶抑制剂。本论文对23 个 S-DABO 类化合物和8 个AZT－氟喹喏酮类偶联物的体外抗HIV 活性进行检 测，并对其中活性较高的化合物进行靶点和机制研究。 23 个S-DABO 类化合物采用对C8166 细胞的毒性试验，对HIV-1ⅢB 诱导的 合胞体形成的抑制试验和对HIV-1ⅢB 急性感染的MT-4 细胞的保护试验进行抗 HIV-1 活性初步筛选。试验结果发现所有化合物均对多种HIV 宿主细胞毒性小， 其中22 个化合物具有抗HIV-1 活性，特别是化合物RZK-4 和RZK-5，其对 HIV-1ⅢB 诱导的合胞体形成的SI 值（Selective index）分别为>16666 和>38462； RZK-4 和RZK-5 对HIV-1ⅢB 急性感染的MT-4 细胞的保护的SI 值分别为2666.67 和2150.54，与相应的阳性对照药品NVP（Nevirapine）的SI 值相接近。以p24 抗原水平为指标，对其中20 个化合物的抗HIV-1 活性进行确证，发现这20 个 化合物均能抑制 HIV-1ⅢB p24 抗原的产生，其中RZK-4 和RZK-5 的EC50 值分 别为5.93 和5.74ng/ml，比相应的阳性对照药品NVP（Nevirapine）的EC50 值 要低（27.3ng/ml）。这些化合物对试验株HIV-1MN、临床分离株HIV-1KM018、非 核苷类抑制剂耐药株HIV-1ⅢB A17 也有较好的抑制效果。但这23 个S-DABO 类化合物对HIV-2 病毒株均无抑制作用。通过检测化合物对感染与未感染细胞的 融合的抑制、对HIV-1 逆转录酶和蛋白酶活性的抑制、对慢性感染H9 细胞 （H9/HIV-1ⅢB）中病毒复制的抑制等试验来探讨化合物的抗HIV-1 机制。结果 显示：有20 个化合物对HIV-1 蛋白酶（PR）有抑制作用，其中有17 个化合物 对HIV-1 逆转录酶（RT）有抑制作用；但所有化合物均不能抑制感染与未感染 细胞的融合，也不能抑制慢性感染H9 细胞中病毒的复制。试验结果表明，这 23 个S-DABO 类化合物主要通过抑制HIV-1 逆转录酶来发挥作用，它们是典型 的非核苷类RT 抑制剂。 8 个AZT－氟喹喏酮类偶联物采用对C8166 细胞的毒性试验，对HIV-1ⅢB 诱导的合胞体形成的抑制试验和对HIV-1ⅢB急性感染的MT-4 细胞的保护试验 进行抗HIV-1 活性初步筛选。试验结果发现其中2 个化合物SRLZ 和SROZ 有 较显著的抗HIV-1 活性，其对HIV-1ⅢB诱导的合胞体形成抑制的SI 值分别为 >41667 和>105263；对HIV-1ⅢB 急性感染的MT-4 细胞的保护的SI 值分别为 30162 和 6368，与AZT（Zidothymidine）的SI 值相近似。以p24 抗原水平为 指标，对其抗HIV-1活性进行确证，发现化合物SRLZ和SROZ均能抑制HIV-1ⅢB p24 抗原的产生，其EC50 值分别为 0.71 和2.1ng/ml,比相应的阳性对照药品AZT 的EC50 值要低（3.5ng/ml）。化合物SRLZ 和SROZ 对临床分离株HIV-1KM018 也有较好的抑制活性，其EC50 值分别为1.4 和22ng/ml。通过检测化合物对慢 性感染H9 细胞（H9/HIV-1ⅢB）中病毒复制的抑制试验来探讨化合物的抗HIV-1 机制，结果表明化合物SRLZ 和SROZ 均不能抑制慢性感染H9 细胞中病毒的 复制。通过检测化合物对金黄色葡萄球菌的抑制作用来检测其抗菌活性，化合 物SRLZ 和SROZ 对金黄色葡萄球菌有较好的抑制作用，其MIC（Minimum inhibitory concentration）值分别为14.65 和7.32μg/ml，与其相应的阳性对照药 物的MIC 值相类似。试验结果表明：药物—药物偶连这种化学修饰方法并没有 改变AZT－氟喹喏酮类偶联物的抗HIV 作用靶点，但也没有较大地影响到其体 外抗病毒活性和抗微生物活性。

两种AZT-氟喹诺酮偶联物体外抗HIV-1及抗菌活性的研究

目的 体外测定两种AZT-氟喹诺酮偶联物SRLZ和SROZ的抗HIV-1活性及抗菌活性.方法 通过合胞体抑制、HIV-1感染细胞保护、HIV-1 p24抗原测定等方法检测急性感染中化合物对HIV-1实验株、临床分离株的抑制作用和对慢性感染细胞中的病毒复制影响;通过体外金黄色葡萄球菌的抑制实验检测化合物的抗菌活性.结果 AZT-氟喹诺酮偶联物SRLZ和SROZ能抑制HIV-1实验株诱导的合胞体形成,减少病毒感染细胞的死亡和抑制病毒在细胞内的复制;SRLZ和SROZ对HIV-1临床分离株也有较好的抑制作用;SRLZ和SROZ对HIV-1的抑制活性与AZT相近;AZT-氟喹诺酮偶联物也能抑制金黄色葡萄球菌,其MIC值与其相应的阳性药物相近.结论 SRLZ和SROZ有很好的抗HIV-1活性和抗菌活性.

Human immunodeficiency virus-1 genotypic drug resistance among volunteer blood donors in Yunnan, China

BACKGROUND: Drug resistance profiles of human immunodeficiency virus-1 (HIV-1) in treatment-naive infections have been reported in developed countries. However, little is known in developing countries, including China, especially in treatment-naive volunt

Complete genomic sequences for hepatitis C virus subtypes 6e and 6g isolated from Chinese patients with injection drug use and HIV-1 co-infection

In one of our recent studies, two HCV genotype 6 variants were identified in patients from Hong Kong and Guangxi in southern China, with injection drug use and HIV-1 co-infection. We report the complete genomic sequences for these two variants: GX004 and

Abnormal regional homogeneity of drug-naive obsessive-compulsive patients

To explore the possible abnormal resting-state activity in patients with obsessive-compulsive disorder (OCD), the regional homogeneity (ReHo) of 22 pairs of patients and well-matched healthy controls was calculated. Compared with controls, the patients showed higher ReHo in the left anterior cingulate cortex, but lower ReHo in the left inferior temporal gyrus. These findings supported the abnormal resting-state brain activity in drug-naive OCD patients. No significant correlations between ReHo value and four clinical characteristics were found, suggesting that abnormal ReHo might be trait-related in OCD. NeuroReport 21:786-790 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

High prevalence of HIV-1 and hepatitis C virus coinfection among injection drug users in the southeastern region of Yunnan, China

The southeastern region of Yunnan province is a key site for drug trafficking and HIV-1 infection spread from the west of Yunnan and Laos to southeastern China. To investigate the prevalence of HIV-1 infection and hepatitis C virus (HCV) coinfection among injection drug users (IDUs) in southeastern Yunnan, three cohorts of 285 addicts, including 242 IDUs and 43 oral drug users, living in the cities of Gejiu and Kaiyuan and the county of Yanshan were studied. HIV-1 and HCV infections were detected by enzyme-linked immunosorbent assay and/or polymerase chain reaction. Data on the age, sex, risk behavior, drug use history, employment, ethnic background, and marriage status were obtained by interview. The overall prevalence of HIV-1 infection was 71.9%. The rate of HCV coinfection among 138 HIV-1-infected IDUs was 99.3%. Most HIV-infected IDUs were 20 to 35 years old (86.7%) and were ethnic Han (75.9%), suggesting that the epidemic in Yunnan is no longer confined to non-Han ethnic minorities, HIV prevalence in female IDUs (81.2%) was significantly higher than in male IDUs (68.2%) (p <.05). The prevalence of HIV infection reached 68.4% after 1 year of injection drug use. Needle/syringe sharing is the major high risk factor for the spread of HIV-1 and HCV infections. Large-scale educational campaigns are urgently needed to reduce the spread of HIV and HCV infection in these regions.

In vitro activities of small peptides from snake venom against clinical isolates of drug-resistant Mycobacterium tuberculosis

The recent re-emergence of tuberculosis, especially the multidrug-resistant cases, has highlighted the importance of screening effective novel drugs against Mycobacterium tuberculosis. In this study, the in vitro activities of small peptides isolated from snake venom were investigated against multidrug-resistant M. tuberculosis. Minimum inhibitory concentrations (MICs) were determined by the Bactec TB-460 radiometric method. A small peptide with the amino acid sequence ECYRKSDIVTCEPWQKFCYREVTFFPNHPVYLSGCASECTETNSKWCCTTDKCNRARGG (designated as vgf-1) from Naja atra (isolated from Yunnan province of China) venom had in vitro activity against clinically isolated multidrug-resistant strains of M. tuberculosis. The MIC was 8.5 mg/l. The antimycobacterial domain of this 60aa peptide is under investigation. (C) 2003 Elsevier Science B.V. and the International Society of Chemotherapy. All rights reserved.

Retention of the developmental pluripotency in medaka embryonic stem cells after gene transfer and long-term drug selection for gene targeting in fish

Embryonic stem (ES) cells provide a unique tool for introducing random or targeted genetic alterations, because it is possible that the desired, but extremely rare recombinant genotypes can be screened by drug selection. ES cell-mediated transgenesis has so far been limited to the mouse. In the fish medaka (Oryzias latipes) several ES cell lines have been made available. Here we report the optimized conditions for gene transfer and drug selection in the medaka ES cell line MES1 as a prelude for gene targeting in fish. MES1 cells gave rise to a moderate to high transfection efficiency by the calcium phosphate co-precipitation (5%), commercial reagents Fugene (11%), GeneJuice (21%) and electroporation (>30%). Transient gene transfer and CAT reporter assay revealed that several enhancers/promoters and their combinations including CMV, RSV and ST (the SV40 virus early gene enhancer linked to the thymidine kinase promoter) were suitable regulatory sequences to drive transgene expression in the MES1 cells. We show that neo, hyg or pac conferred resistance to G418, hygromycin or puromycin for positive selection, while the HSV-tk generated sensitivity to ganciclovir for negative selection. The positive-negative selection procedure that is widely used for gene targeting in mouse ES cells was found to be effective also in MES1 cells. Importantly, we demonstrate that MES1 cells after gene transfer and long-term drug selection retained the developmental pluripotency, as they were able to undergo induced differentiation in vitro and to contribute to various tissues and organs during chimeric embryogenesis.

中国部分地区未经治疗HIV-1 感染者耐药基因研究

高效抗逆转录病毒治疗(HAART)的应用，极大的降低了AIDS发病率和死亡 率，延长了HIV感染者的生命。但HIV耐药在很大程度上影响了HAART的疗效， 耐药株的产生成为影响抗病毒治疗效果的主要因素。欧洲、美国的耐药监测技术 规范均推荐在新感染未经抗病毒药物治疗的患者中进行原发耐药检测。我国政府 于2003年底出台了艾滋病治疗的“四免一关怀”政策，陆续在全国范围内开展了大 规模的免费抗病毒治疗，监测我国未经抗病毒药物治疗HIV-1感染者中的耐药情 况可以为制定合理的用药方案和减少耐药毒株出现提供科学依据。 根据世界卫生组织(WHO)的“HIV 耐药监测指南”，无偿献血者中的HIV-1 感染者，可以认定为HIV 新诊断未治疗人群。分析了云南无偿献血者的血浆和 外周血单核细胞(PBMC)，研究云南无偿献血人群的耐药状况。 已有实验室血清学方法识别HIV-1 新近感染和长期感染，用BED-CEIA 方 法，在河南、安徽、山西自愿咨询检测(VCT)人群中检出新近感染人群，进行耐 药基因研究, 对照研究了部分长期感染人群。 样品提取核酸后，巢式聚合酶链反应(nested-PCR)扩增pol 基因区(含蛋白酶 区1～99 氨基酸全长和逆转录酶区1～242 氨基酸)。PCR 产物双脱氧法测序，所 得序列与洛斯阿拉莫斯HIV 核酸序列库(Los Alamos HIV Database)标准株构建系 统进化树分析亚型；用斯坦福大学耐药数据库(Standford HIV Drug Resistance Database)分析耐药。 研究发现，云南省2005～2006 年无偿献血者中，有52 例为HIV-1 阳性，其 中49 例血浆和相应的PBMC 样品病毒基因扩增成功。序列分析表明，HIV 病毒 的亚型分布为CRF08_BC (51.0%), CRF07_BC (24.5%), CRF01_AE (20.4%)和B (4.1%)；所有样品均未发现蛋白酶抑制剂（PI）耐药基因位点主要突变，只在6 例(11.7%)样品中发现7 例次PI 次要耐药位点突变；另外，在9 例(18.4%)样品中发现10 例次核苷类逆转录酶抑制剂(NRTI) 耐药突变，1 例(2.0%)发生非核苷类 逆转录酶抑制剂(NNRTI) 耐药突变；针对具体药物PI/NRTI/NNRTI 均只有1 例 有潜在的低度耐药，临床仍对药物敏感。PBMC 和血浆的病毒耐药没有显著差异。 从河南、安徽、山西27 个VCT 检测点2006～2007 年采集的10310 例样品 中，通过WB 和BED-CEIA 检测出新近感染人群63 例，分析成功50 例血浆样 品；河南VCT 长期感染样品中随机抽样，分析成功19 例样品。分析成功的69 例VCT 样品中，HIV 病毒株的亚型分布分别为B’ (95.7%)，CRF01_AE(2.9%)和 C(1.4%)。上诉样品均未检出PI 主要耐药相关突变，只在26 例(37.7%)样品中存 在27 例次PI 次要耐药相关突变；3 例(4.3%)样品出现6 例次NRTI 耐药相关突 变，7 例(10.1%)样品出现8 例次NNRTI 耐药相关突变。通过与斯坦福大学耐药 数据库比对，没有发现针对PI 类药物的临床耐药；但有2 例(2.8%)针对NRTI 类 药物耐药，1 例有M184V 突变导致对拉米夫定(3TC)和氟代拉米夫定(FTC)高度 耐药；1 例样品存在T215Y、M41L、L210W 三重突变位点，对阿巴卡韦(ABC)、 去羟肌苷(ddI)和坦那夫韦(TDF)中度耐药，对齐多夫定(AZT)和司他夫定(d4T)高 度耐药；针对NNRTI 类药物，有3 例(4.3%)毒株有耐药，1 例有K103N 突变导 致对奈韦拉平(NVP)、地拉韦啶(DLV)和依菲韦伦(EFV)的高度耐药；1 例有Y188L 突变导致对NVP 和EFV 的高度耐药；1 例存在K101E 和G190A 双重突变，导 致对NVP 的高度耐药，对DLV、EFV 和依曲韦林(ETR)中度耐药。 比较长期感染和新近感染者之间的亚型和耐药，未发现显著差异。 研究结果表明，云南、河南和安徽未经治疗HIV-1 感染者中耐药处于低流行 状态。亚型分布云南无偿献血者以CRF_BC 为主，河南、安徽VCT 人群以B’ 为主。应持续在未经治疗人群中进行耐药监测。

Separation of drug enantiomers by capillary electrophoresis in the presence of neutral cyclodextrins

This is a selected review, highlighting our results obtained in an extended screening program ("The German-Chinese Drug Screening Program"), with a focus on a set of original data obtained with heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin(TM-beta-CD) as the chiral solvating agent (CSA). The enantioseparation of 86 drugs by capillary zone electrophoresis in the presence of this CSA was successful for 47 drugs. The migration separation factors (alpha(m)) and the migration retardation factors (R-m) were compared with those found for native beta-cyclodextrin (beta-CD). The patterns thus obtained were also compared with those observed for hexakis(2,3,6-tri-O-methyl)-alpha-CD (TM-alpha-CD) and octakis(2,3,6-tri-O-methyl)-gamma-CD (TM-gamma-CD), respectively. From the statistical data, it can be concluded that there is a remarkable influence of the analyte structure on the electrophoretic data. A substructure 4H was found in the analyte structure that has a significant influence on the analytes' behaviour. Thus, analytes bearing the substructure 4H do not only have a strong affinity to the CDs but also a high rate of success of chiral separation in all systems reviewed. In light of this, the different ring sizes of native cyclodextrins (alpha-, beta- and gamma-CD) readily explain their behaviour towards a limited test set of chiral drugs. Sterical considerations point to the significance of side-on-binding versus inclusion in the cavity of the host. In addition to the findings from the screening program, numerous references to the Literature are given. (C) 2000 Elsevier Science B.V. All rights reserved.