Cervical cancer screening, screening errors and reporting

Screening for cervical carcinoma by cervicovaginal cytology has led to a marked reduction in the incidence of and mortality from this tumor over the last 50 years in essentially all countries with a functioning screening program. It is the most successful cancer prevention program of all times. Consequently, approximately 80% of the current incidence of and mortality from this disease occurs in geographic areas of underserved and underscreened women. Essential components of a successful program are a high coverage rate of the female population, screening at regular intervals, well-trained clinical and laboratory staff, and an efficient follow-up and treatment system. Deficiencies in any of these areas may lead to a failing screening system. Thus, the most important reason for the remaining mortality from cervical carcinoma in developed countries is lack of complete coverage. It is questionable if new and more expensive technologies will be able to renmedy the remaining failures of the system if no improvement in the coverage rate is achieved. Screening errors do occur but represent only a small fraction of screening failures. Currently, there are a number of terminology systems around the world; thus, a unified terminology is currently not a realistic goal.     

表达H5N1亚型禽流感病毒HA蛋白的重组鼠白血病病毒的特性

通过反转录 聚合酶链式反应 (RT PCR)扩增了H5N1亚型鹅源禽流感病毒 (AIV)完整的血凝素 (HA)基因并进行了克隆与鉴定。序列测定结果已经登陆GenBank ,登陆号为AY6 394 0 5。序列分析表明所扩增的HA基因开放性阅读框架 (ORF)由170 7个核苷酸组成 ,共编码 5 6 8个氨基酸 ,裂解位点的氨基酸组成为RKKR↓GLF ,含连续的碱性氨基酸 ,具有高致病性AIVHA基因裂解位点的特征。构建了含HA基因的真核表达载体pcDNA HA ,通过与鼠白血病病毒 (MuLV)假病毒构建体系的两种质粒pHIT6 0和pHIT111共转染人胚肾细胞 2 93T ,4 8h后收集假病毒上清 ,超离后通过Western blot证明HA蛋白能够在假病毒颗粒表面表达 ,表明HA能够整合到此病毒粒子表面。通过感染 2 93T、COS 7和NIH3T3三种不同的靶细胞 ,证实所构建的假病毒粒子具有感染性和泛嗜性。本研究成功构建了具有感染性的MuLV HA假病毒体系 ,为研究鹅源禽流感病毒侵入细胞的机理及其组织嗜性的变异提供一种新方法。     

Summary statement on quantitative cytochemistry (DNA and molecular biology): Task Force 8

OBJECTIVE: To reach consensus on the application of quantitative cytochemical analysis of chromosomal and DNA aneuploidy in cervical cytopathology. CONCLUSION: The current Pap test has limited specificity to predict cancer and its truly progressive pre-malignant lesions. Infection with human papillomavirus may trigger genetic instability, hyperproliferation and immortalization of the cervical mucosa and cause cervical cancer. Several related molecular markers have been shown to be informative about this neoplastic process. Quantitative analysis of chromosomal and DNA aneuploidy has been shown to be an important tool for identifying (progression to) high grade squamous intraepithelial lesions. A high degree of standardization (material handling, calibration and quality control, measurement and interpretation of results) is required for accurate and reproducible measurements. Areas for further study are presented.     

Injection drug use and HIV/AIDS transmission in China

INTRODUCTION Although sexual transmission accounts for most of the AIDS epidemic globally, HIV/AIDS among injecting drug users (IDUs) is a growing problem worldwide. First de- tected in China in 1989 among drug abusers on the Yunnan border, HIV/AIDS subse…