简介:摘要目的比较正常生育男性及少弱精子症患者DAZL基因启动子区域DNA甲基化水平的差异。方法采用病例对照研究,回顾性分析2018年6月至2019年6月期间于徐州医科大学附属连云港医院就诊的具有正常生育男性(对照组)15例和少弱精子症患者35例(少弱精子症组)的临床资料,对精液标本进行精子形态与精子浓度、活力分析。提取精液基因组DNA行亚硫酸氢盐处理,利用PCR体外扩增并将PCR产物经纯化后与pCR2.1载体连接及酶切验证,挑选阳性克隆进行测序和DNA甲基化程度差异比较。结果对照组DAZL基因启动子均呈低甲基化水平,甲基化率为0.96%±0.46%,少弱精子症组甲基化率为12.15%±11.35%,组间差异有统计学意义(P=0.000 4);DAZL基因甲基化率在少弱精子症组患者中个体差异明显,有12例(34.3%)患者DNA甲基化水平超过10%。结论DAZL基因启动子区域甲基化异常可能和少弱精子症有关,有望成为男性生精缺陷的生物学标志之一。
简介:摘要机体的免疫功能与肿瘤的发生发展密切关联,一方面,机体可以通过免疫效应机制,包括固有免疫和特异性免疫,发挥抗肿瘤作用;另一方面,肿瘤细胞通过免疫逃逸机制逃避免疫系统的识别和清除。越来越多的证据表明表观遗传调控在实体肿瘤免疫调节中占有重要地位,其中,DNA甲基化作为目前研究最久、最深入的表观遗传机制,除了促进肿瘤的恶性转化,也影响机体免疫细胞对肿瘤的免疫应答。本文主要针对DNA甲基化对实体肿瘤免疫反应的调节作用进行阐述。
简介:AbstractBackground:Circulating tumor DNA (ctDNA) is a promising biomarker for non-invasive epidermal growth factor receptor mutations (EGFRm) detection in lung cancer patients, but existing methods have limitations in sensitivity and availability. In this study, we used the ΔCt value (mutant cycle threshold [Ct] value-internal control Ct value) generated during the polymerase chain reaction (PCR) assay to convert super-amplification-refractory mutation system (superARMS) from a qualitative method to a semi-quantitative method named reformed-superARMS (R-superARMS), and evaluated its performance in detecting EGFRm in plasma ctDNA in patients with advanced lung adenocarcinoma.Methods:A total of 41 pairs of tissues and plasma samples were obtained from lung adenocarcinoma patients who had known EGFRm in tumor tissue and were previously untreated. EGFRm in ctDNA was identified by using superARMS. Through making use of ΔCt value generated during the detection process of superARMS, we indirectly transform this qualitative detection method into a semi-quantitative PCR detection method, named R-superARMS. Both qualitative and quantitative analyses of the data were performed. Kaplan-Meier analysis was performed to estimate the progression-free survival (PFS) and overall survival (OS). Fisher exact test was used for categorical variables.Results:The concordance rate of EGFRm in tumor tissues and matched plasma samples was 68.3% (28/41). At baseline, EGFRm-positive patients were divided into two groups according to the cut-off ΔCt value of EGFRm set at 8.11. A significant difference in the median OS (mOS) between the two groups was observed (EGFRm ΔCt ≤8.11 vs. >8.11: not reached vs. 11.0 months; log-rank P = 0.024). Patients were divided into mutation clearance (MC) group and mutation incomplete clearance (MIC) group according to whether the ΔCt value of EGFRm test turned negative after 1 month of treatment. We found that there was also a significant difference in mOS (not reached vs. 10.4 months; log-rank P = 0.021) between MC group and MIC group. Although there was no significant difference in PFS between the two groups, the two curves were separated and the PFS of MC group tended to be higher than the MIC group (not reached vs. 27.5 months; log-rank P = 0.088). Furthermore, EGFRm-positive patients were divided into two groups according to the cut-off of the changes in ΔCt value of EGFRm after 1 month of treatment, which was set at 4.89. A significant difference in the mOS between the two groups was observed (change value of ΔCt >4.89 vs. ≤4.89: not reached vs. 11.0 months; log-rank P = 0.014).Conclusions:Detecting EGFRm in ctDNA using R-superARMS can identify patients who are more likely sensitive to targeted therapy, reflect the molecular load of patients, and predict the therapeutic efficacy and clinical outcomes of patients.
简介:AbstractBackground:Epigenetics, especially DNA methylation, plays an important role in the pathogenesis of primary Sjogren syndrome (pSS). Our study aimed to reveal the role of DNA methylation in peripheral monocytes of pSS patients.Methods:A total of 11 pSS patients and five age-matched healthy controls (HCs) were included in this study. Monocytes were isolated from peripheral blood mononuclear cells using magnetic microbeads. DNA methylation profiles were generated using Human Methylation 850K BeadChips.Results:In monocytes from pSS patients, we identified 2819 differentially methylated positions (DMPs), comprising 1977 hypomethylated- and 842 hypermethylated-DMPs, corresponding to 1313 unique genes when compared with HCs. IFI44L, MX1, PAARP9, and IFITM1, which influence the interferon (IFN) signaling pathway, were among the genes hypomethylated in pSS. Functional analysis of genes with a minimum of two DMPs showed involvement in antigen binding, transcriptional regulation, cell adhesion, IFN-γ pathway, type I IFN pathway, antigen presentation, Epstein-Barr virus infection, human T-lymphotropic virus type 1 virus infection, and metabolic disease-related pathways. In addition, patients with higher serum IgG levels exhibited enrichment in Notch signaling and metabolic-related pathways. Upon comparing monocytes with salivary gland epithelial cells, an important overlap was observed in the cell cycle, cell senescence, and interleukin-17 signaling pathways. The differentially methylated genes were more enriched in the ribosome- and AMP-activated protein kinase signaling pathway in anti-Ro/SSA and anti-La/SSB autoantibodies double-positive patients.Conclusion:Genome-wide DNA methylation profiling revealed significant differences in DNA methylation in monocytes isolated from patients with pSS.
简介:【摘要】目的:本文主要是对DNA自动化检验技术在法医领域物证提取工作内容进行分析。方法:本文对2020年6月到2021年6月内所发生的案件中所涉及400份物证为基础,并通过-chelex法的两种应用方法进行分析,以此来完成检测结果的比较工作。结果:尽管手工模式下的-chelex法和工作站模式下的-chelex法在成功率上大体相同(P>0.05),不过后者的所用时间要远远短于前者,而DNA自动化检验技术的存在能够尽可能降低孔间交叉感染情况的出现。结论:当法医人员在开展物证检验的过程中,可以利用DNA自动化检验技术的特性,这样能够缩短破案时间,提高检测结果的精准性,以此来确保案件能够顺利破获。
简介:摘要:很多犯罪嫌疑人在作案期间都有着非常强的反侦查意识,因此,刑事科当中的技术人员如何在犯罪嫌疑人犯罪现场找出证据和线索,需要其在工作期间具有极为敏锐的观察力以及逻辑思维能力。在人身认定当中,手印和DNA都是能够直接进行认定的生物特征识别技术,在勘查犯罪现场时,所有的刑事技术人员都无法采取措施同时获得到手印以及手印当中的DNA生物作为案件的检材,如果先显现出指纹就无法进行DNA的提取,而如果先进行了DNA的提取也就会破坏了指纹,所以,在生物检材提取时,如何兼顾到手印以及手印当中DNA提取是所有刑事技术人员的共同愿望,如此才能够更好地对现场手印进行开发和利用,为案件提供证据,形成更加坚固的证据链。本文正是基于此,首先分析了手印和DNA间的联系和区别,最后总结了提取手印和DNA 生物检材的具体策略。
简介:[摘要]随着现代医疗水平的发展,CT检查已经成为一项常见的检查,为医生的临床诊断提供了重要依据,在这次新型冠状病毒肺炎(COVID-19)的诊断中起着至关重要的作用。在我们医院一台CT 一天的工作量大概是240例病人左右,机器在频繁的使用过程中就会出现各种问题。本文是基于西门子Life Net上记录的设备维修维护记录上出现频率较高的故障进行分析,探讨西门子SOMATOM Definition AS螺旋CT在工作中出现的常见问题和解决方案。