A novel design for estimating relative accuracy of screening tests when complete disease verification is not feasible

The accuracy (sensitivity and specificity) of a new screening test can be compared with that of a standard test by applying both tests to a group of subjects in which disease status can be determined by a gold standard (GS) test. However, it is not always feasible to administer a GS test to all study subjects. For example, a study is planned to determine whether a new screening test for cervical cancer ("ThinPrep") is better than the standard test ("Pap"), and in this setting it is not feasible (or ethical) to determine disease status by biopsy in order to identify women with and without disease for participation in a study. When determination of disease status is not possible for all study subjects, the relative accuracy of two screening tests can still be estimated by using a paired screen-positive (PSP) design in which all subjects receive both screening tests, but only have the GS test if one of the screening tests is positive. Unfortunately in the cervical cancer example, the PSP design is also infeasible because it is not technically possible to administer both the ThinPrep and Pap at the same time. In this article, we describe a randomized paired screen-positive (RPSP) design in which subjects are randomized to receive one of the two screening tests initially, and only receive the other screening test and GS if the first screening test is positive. We derive maximum likelihood estimators and confidence intervals for the relative accuracy of the two screening tests, and assess the small sample behavior of these estimators using simulation studies. Sample size formulae are derived and applied to the cervical cancer screening trial example, and the efficiency of the RPSP design is compared with other designs.     

Ram seminal plasma improves pregnancy rates in ewes cervically inseminated with ram semen stored at 5 °C for 24 hours

In this study, we compared pregnancy rates obtained using ram semen stored at 5 °C for 24 h, with ram or bull seminal plasma (SP) added to TRIS-egg yolk extender. During the breeding period, 670 adult Corriedale ewes were cervically inseminated with semen (2 × 10⁸ sperm in a volume of 0.2 mL) from eight adult Corriedale rams. Ejaculates, obtained using an artificial vagina, were split into three aliquots and diluted with the following: TRIS-egg yolk based extender (T), T + 30% ram SP (R), or T + 30% bull SP (B). Samples were refrigerated and stored at 5 °C for 24 h until used for AI. Pregnancy was assessed by ultrasonography 35 to 40 d after AI. Pregnancy rate was not affected by ram (P = 0.77) or breeding period (P = 0.43), and there were no interactions between extender and ram (P = 0.94), or extender and breeding period (P = 0.24). However, there was an effect of extender (P = 0.0009) on pregnancy rates; ram SP, but not bull SP, increased pregnancy rates compared with extender without SP (49.7, 38.1, and 31.1%, for R, B, and T respectively). In conclusion, ram SP added to TRIS-egg yolk extender had a beneficial effect on the pregnancy rate of ram sperm stored at 5 °C for 24 h and used for cervical insemination of ewes.     

Isolation and characterization of cancer stem cells from cervical cancer HeLa cells

Cervical cancer is one of the most common gynecologic malignancies and poses a serious health problem worldwide. Identification and characterization of cervical cancer stem cells may facilitate the development of novel strategies for the treatment of advanced and metastatic cervical cancer. Breast cancer-resistance protein (Bcrp1)-positive cells were selected from a population of parent HeLa cells using flow cytometry. The invasion capacity of Bcrp1-positive and -negative cells was analyzed with a Boyden chamber invasion test. The tumorigenicity of these cells was determined by in vivo transplantation in non-obesity diabetes/severe combined immunodeficiency (NOD/SCID) mice. The Bcrp1-positive subpopulation accounted for about 7% of the parent HeLa cell population. The proliferative capacity of the Bcrp1-positive cells was greater than that of the Bcrp1-negative cells (P < 0.05). In the invasion assay, the Bcrp1-positive cells demonstrated a greater invasive capacity through the artificial basement membrane than their Bcrp1-negative counterparts. Following transplantation of 10⁴ cells, only the Bcrp1-positive cells formed tumors in NOD/SCID mice. When 10⁵ or 10⁶ cells were transplanted, the tumor incidence and the tumor mass were greater in the Bcrp1-positive groups than those in the Bcrp1-negative groups (P < 0.05). The Bcrp1-positive subpopulation cervical cancer stem cells.     

Molecular screening of compounds to the predicted Protein-Protein Interaction site of Rb1-E7 with p53- E6 in HPV

Cervical cancer is malignant neoplasm of the cervix uteri or cervical area. Human Papillomaviruses (HPVs) which are heterogeneous groups of small double stranded DNA viruses are considered as the primary cause of cervical cancer, involved in 90% of all Cervical Cancers. Two early HPV genes, E6 and E7, are known to play crucial role in tumor formation. E6 binds with p53 and prevents its translocation and thereby inhibit the ability of p53 to activate or repress target genes. E7 binds to hypophosphorylated Rb and thereby induces cells to enter into premature S-phase by disrupting Rb-E2F complexes. The strategy of the research work was to target the site of interaction of Rb1 -E7 & p53-E6. A total of 88 compounds were selected for molecular screening, based on comprehensive literature survey for natural compounds with anti-cancer activity. Molecular docking analysis was carried out with Molegro Virtual Docker, to screen the 88 chosen compounds and rank them according to their binding affinity towards the site of interaction of the viral oncoproteins and human tumor suppressor proteins. The docking result revealed that Nicandrenone a member of Withanolides family of chemical compounds as the most likely molecule that can be used as a candidate drug against HPV induced cervical cancer. ABBREVIATIONS: HPV - Human Papiloma Virus, HTSP - Human Tumor Suppressor Proteins, VOP - Viral oncoproteins.     

扩散张量成像对颈椎病脊髓早期损伤的研究

目的:探讨磁共振(MR)扩散张量成像(DTI)作为定量分析方法,对脊髓型颈椎病(CSM)脊髓早期损伤诊断的应用价值.方法:选择45例经临床及影像诊断为脊髓型颈椎病患者,颈椎常规MRI检查显示脊髓内无异常信号,使用单次激发自旋回波平面(SE-EPI)序列,进行DTI扫描.测量压迫部位脊髓的ADC值及FA值作为病例组,选择病变上或下方两个节段以上未受压正常脊髓作为正常对照组,测量其ADC值及FA值.分析病例组与对照组间ADC及FA值差别,计算ADC值及FA值诊断脊髓损伤的敏感性.结果:所有脊髓型颈椎病患者经DTI检查均可得到ADC图及FA图,经图像后处理,脊髓显示清晰,图像无变形及伪影.3例脊髓型颈椎病患者ADC值降低,42例脊髓型颈椎病患者ADC值增高,平均ADC值为(1.388± 0.149)x 10-3 mm2/s.44名脊髓型颈椎病患者FA值降低,1名脊髓型颈椎病患者FA值增高,平均FA值为0.476±0.085,受压处脊髓平均ADC值升高,平均FA值下降,与正常值比较差别有统计学意义.ADC值诊断的敏感性为93.33％,FA值诊断的敏感性为97.78％.结论:DTI与常规MR比较,能早期而准确地诊断脊髓型颈椎病脊髓早期损伤.     

HPV基因的进化分析

目的:HPV有许多类型,其大致可分为高危型和低危型,高危型HPV感染是导致宫颈癌发生的首要原因,在HPV基因组中,E6基因是促进宫颈细胞癌变的关键基因,本文主要研究HPV中的E6基因在各种不同型别的HPV中的进化关系,并对E2基因碱基替换率进行分析,探讨高危型HPV与低危型HPV的区别.方法:本文对不同类型HPV E6氨基酸序列构建系统发生树,探讨识别高危型HPV可能的一致序列,对E6基因其中一处能导致恶性程度增加的突变进行分析.并对HPV16与其位于同一颗树的HPV35和HPV31计算相对碱基替换率.结果:高危型HPV均源自同一株病毒株的进化.各种HPV型别中,高危型HPV E6蛋白对应于HPV16E6蛋白的第83位氨基酸为缬氨酸更为保守,HPV中除E2以外的其他基因的非同义替换率均小于同义替换率.结论:HPV E6蛋白对应于HPV16E6蛋白的第83位氨基酸为缬氨酸能更好地实现HPV E6蛋白的致癌作用.HPV基因中除E2以外的基因在进化过程中都较为保守,是HPV增殖生长的关键基因,而E2部分区域非同义替换率大于同义替换率,说明E2这部分区域的突变能够更好的促进HPV的增殖和生长.     

HPV-DNA 和TCT 检测在宫颈癌前病变筛查中的诊断价值

目的:探讨乳头瘤病毒定性检测( HPV- DNA)与液基薄层细胞学检查技术(TCT)在宫颈癌前病变中的诊断价值.方法:分别采用HPV- DNA及TCT法检测1536例患者,对TCT阳性、HPV- DNA阳性病例者进行阴道镜下活检.结果:随着病理诊断级别的升高,高危型HPV感染率上升,而低危型HPV感染多见于轻度不典型增生(CINⅠ)及其以下病变,HPV混合感染在各组间未见明显趋势.HPV-DNA检测与宫颈活检的符合率为66.78％.随着病理级别的升高,不典型鳞状细胞(ASCUS)组的感染率呈降低趋势,鳞状上皮内低度病变(LSIL)组感染率亦呈下降趋势,而鳞状上皮内高度病变(HSIL)组和鳞癌(SCC)组感染率均呈上升趋势,TCT检测与组织学诊断的符合率为66.67％,与HPV-DNA检查比较,差异无统计学意义(x=0.001,P＞0.05).结论:HPV-DNA、TCT及宫颈活检三者检测相结合,能明显提高诊断的正确性.     

鬼臼毒素涂膜剂治疗子宫颈HPV 感染的疗效观察

目的:了解鬼臼毒素涂膜剂治疗子宫颈HPV感染的疗效。方法:126例临床诊断证明为子宫颈HPV感染的患者,随机分为两组,试验组63例采用0.5%鬼臼毒素涂膜剂治疗,对照组63例单独采用0.5%鬼臼毒素酊治疗。结果:①痊愈率:试验组与对照组的痊愈率分别为90.5%、73.00%,两组比较具有统计学学差异(P<0.05);②复发率:试验组与对照组第12、24周的复发率分别为9.52%、28.57%和9.52%、36.51%,两个时段的两组比较均具有统计学差异(P<0.05);③不良反应:经随访观察,两组发生了红斑、水肿、灼热、疼痛、瘙痒、溃疡、渗出等不良反应,其中两组比较试验组红斑、水肿、溃疡、渗出的发生率低于对照组,具有统计学差异(P<0.05)。结论:鬼臼毒素涂膜剂能有效治疗子宫颈HPV感染,并控制复发,副作用小,比采用鬼臼毒素酊治疗的效果好。     

宫颈癌患者外周血CD4+CD25+high调节性T细胞的表达及意义

目的:探讨宫颈癌患者外周血中CD4~ CD25~( high)调节性T(regulator T cells,Tr)的表达及意义。方法:采用流式细胞术检测52例宫颈癌患者,35例健康女性外周血中CD4~ CD25~( high)Tr、细胞毒性T细胞(cytotoxic T lymphocytes,CTL)和NK细胞,采用ELISA检测血清中-干扰素(interferon,IFN-)的表达水平。结果:宫颈癌患者外周血CD4~ CD25~( high)Tr占CD4~ T淋巴细胞的百分比为(7.18±2.32)%,高于健康女性组(P<0.05);宫颈癌患者外周血CD4~ CD25~( high)Tr水平与CTL、NK细胞及IFN-水平呈负相关。结论:宫颈癌患者外周血中具免疫抑制活性的CD4~ CD25~( high)Tr水平较高,参与宫颈癌患者的肿瘤免疫抑制。     

Proteomic analysis of cervical cancer cells treated with suberonylanilide hydroxamic acid

Suberonylanilide hydroxamic acid (SAHA) is an orally administered histone deacetylase inhibitor (HDACI) that has shown significant antitumour activity in a variety of tumour cells. To identify proteins involved in its antitumour activity, we utilized a proteomic approach to reveal protein expression changes in the human cervical cancer cell line HeLa following SAHA treatment. Protein expression profiles were analysed by 2-dimensional polyacrylamide gel electrophoresis (2-DE) and protein identification was performed on a MALDI-Q-TOF MS/MS instrument. As a result, a total of nine differentially expressed proteins were visualized by 2-DE and Coomassie brilliant blue (CBB) staining. Further, all the changed proteins were positively identified via mass spectrometry (MS)/MS analysis. Of these, PGAM1 was significantly downregulated in HeLa cells after treatment with SAHA. Moreover, PGAM1 has been proven to be downregulated in another cervical cancer cell line (CaSki) by western blot analysis. Together, using proteomic tools, we identified several differentially expressed proteins that underwent SAHA-induced apoptosis. These changed proteins may provide some clues to a better understanding of the molecular mechanisms underlying SAHA-induced apoptosis in cervical cancer.