简介：目的探讨尸检老年不同年龄肝组织基因组DNA含量变化。方法选取低温（-80℃）保存尸检的新鲜肝组织样本37例,提取基因组DNA,并按照年龄分为4组：≤65（51.5±15.6）岁组6例,66～79（76.3±2.2）岁组8例,80～89（86.4±1.8）岁组11例,≥90（93.3±4.1）岁组12例,包括2例百岁老人,用紫外光谱法测定DNA含量并进行分析比较。结果（1）80～89岁组DNA含量（0.310±0.286）mg/ml,分别与≤65岁组DNA含量（1.665±0.529）mg/ml、66～79岁组DNA含量（1.393±0.424）mg/ml、≥90岁组DNA含量（1.147±0.333）mg/ml相比,均差异有统计学意义（P〈0.001）,提示80～89岁组DNA含量明显降低;（2）≤65岁、66～79岁、≥90岁3组DNA含量比较,差异无统计学意义（P〉0.05）,但基因组DNA含量有随龄逐渐降低的趋势;（3）≥90岁组DNA含量比80～89岁组DNA含量高。结论（1）人肝组织基因组DNA含量随年龄的增长而降低,表明在衰老过程中,DNA的改变不仅表现在质的方面,在含量上也有所变化;（2）≥90岁组基因组DNA含量出现略有增高的现象。

简介：摘要宿主细胞残留DNA是指可能出现于生物制品中的来自宿主细胞的DNA片段。用传代细胞株生产的生物制品，其宿主细胞残留DNA可能会传递肿瘤或病毒相关基因，存在潜在的危险性。各国药品监督管理机构对宿主细胞DNA的残留量有着严格的限度控制，同时各国药典也提供数种经典的检测方法。建立合适的宿主细胞残留DNA检测方法有助于监测生产工艺，确保生物制品的安全性和质量。此文对宿主细胞残留DNA潜在的危害、国内外监管机构对宿主细胞残留DNA检测标准和检测方法以及各方法的特点及研究进展做一综述。

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：摘要随着检测技术灵敏度的不断提高，循环肿瘤DNA（ctDNA）检测的应用领域逐渐从晚期肿瘤拓展到早期肿瘤。近期，ctDNA在实体瘤微小残留病（MRD）检测中的应用尤其受到关注。MRD检测在实体瘤复发风险评估以及治疗指导方面都展现出了重要的意义。然而，各研究中采用的MRD检测策略有所不同，得出的结论也有所差异。本文回顾了ctDNA在实体瘤MRD检测领域的研究进展，阐述了MRD检测技术及应用方面的挑战，旨在推动ctDNA在实体瘤MRD检测中的临床转化与规范应用。

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：摘要目的探讨血浆供体来源的细胞游离DNA（donor-derived cell-free DNA，dd-cfDNA）片段在鉴别移植肾T细胞介导的排斥反应（T cell-mediated rejection，TCMR）和抗体介导的排斥反应（antibody-mediated rejection，ABMR）中的价值。方法回顾性纳入2017年12月1日至2019年7月18日在浙江大学医学院附属第一医院经肾活检确诊的移植肾急性排斥反应患者。根据2017年Banff移植肾排斥反应病理分类诊断标准将患者分为ABMR组和TCMR组，后者又分为TCMRⅠ型亚组和TCMRⅡ型亚组。采用二代测序+目标区域捕获的方法检测入选者外周血浆dd-cfDNA水平。比较两组患者人口学及临床病理指标的差异。采用受试者工作特征曲线（receiver operating characteristic curve，ROC曲线）评价血浆dd-cfDNA和血肌酐水平对鉴别两种移植肾ABMR和TCMR的诊断价值。结果共60例移植肾急性排斥反应患者入选本研究，TCMR组42例，ABMR组18例。ABMR组患者血浆dd-cfDNA百分比较TCMR组显著升高[2.33（1.19，4.30）%比0.98（0.50，1.82）%，P=0.001]；ABMR组dd-cfDNA绝对值亦较TCMR组显著升高[0.94（0.60，2.27）ng/ml比0.43（0.20，0.96）ng/ml，P=0.003]。ROC曲线分析结果显示，dd-cfDNA百分比鉴别诊断TCMR和ABMR的曲线下面积（area under the curve，AUC）为0.76（95%CI 0.64~0.88），阈值为1.11%，敏感性88.89%，特异性59.52%；dd-cfDNA绝对值鉴别诊断TCMR和ABMR的AUC为0.74（95% CI 0.61~0.86），阈值为0.53 ng/ml，敏感性88.89%，特异性54.76%。TCMR亚组与ABMR组血浆dd-cfDNA水平的比较结果显示，TCMR两亚组间dd-cfDNA百分比及绝对值水平的差异均无统计学意义（均P>0.05）；ABMR组dd-cfDNA百分比显著高于TCMRⅠ型亚组（P=0.008）和TCMRⅡ型亚组（P=0.030）。ABMR组dd-cfDNA绝对值显著高于TCMRⅠ型亚组（P=0.003）。结论血浆dd-cfDNA水平检测对鉴别ABMR和TCMR两种排斥反应类型有辅助诊断价值。

简介：摘要循环肿瘤DNA(ctDNA)作为一种基于血液的生物标志物，在胰腺癌早期诊断、动态监测和预后判断等方面具有一定优势，但也存在样本前处理、提取方法等缺乏统一标准及缺少特异性标志物等难题。未来还需要要进行更大规模的临床试验和技术改进来推进ctDNA在胰腺癌诊疗中的应用。

简介：AbstractBackground:Epigenetics, and especially DNA methylation, contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis (SALS). This study aimed to investigate the role of DNA methylation in SALS using whole blood of SALS patients.Methods:In total, 32 SALS patients and 32 healthy controls were enrolled in this study. DNA was isolated from whole blood collected from the participants. DNA methylation profiles were generated using Infinium MethylationEPIC BeadChip.Results:We identified 34 significant differentially methylated positions (DMPs) in whole blood from SALS patients, compared with the healthy controls. Of these DMPs, five were hypermethylated and 29 were hypomethylated; they corresponded to 13 genes. For the DMPs, ATAD3B and BLK were hypermethylated, whereas DDO, IQCE, ABCB1, DNAH9, FIGN, NRP1, TMEM87B, CCSAP, ST6GALNAC5, MYOM2, and RUSC1-AS1 were hypomethylated. We also identified 12 differentially methylated regions (DMRs), related to 12 genes (NWD1, LDHD, CIS, IQCE, TNF, PDE1C, LGALS1, CSNK1E, LRRC23, ENO2, ELOVL2, and ELOVL2-AS1). According to data from the Kyoto Encyclopedia of Genes and Genomes database, DNAH9 and TNF are involved in the amyotrophic lateral sclerosis (ALS) pathway. Correlation analysis between clinical features and DNA methylation profiling indicated that the methylation level of ELOVL2 and ARID1B was positively associated with the age of onset (r = 0.86, adjust P = 0.001) and disease duration (r = 0.83, adjust P = 0.01), respectively.Conclusions:We found aberrant methylation in DMP- and DMR-related genes, implying that many epigenetic alterations, such as the hypomethylation of DNAH9 and TNF, play important roles in ALS etiology. These findings can be helpful for developing new therapeutic interventions.

简介：摘要线粒体DNA是位于线粒体基质内线粒体自有的遗传物质，参与细胞代谢和能量供给。线粒体DNA的损伤通过增加活性氧的释放加剧氧化应激，线粒体DNA释放亦可引发细胞凋亡及通过损伤相关分子模式激活免疫炎症反应。线粒体自噬则通过负反馈机制调控线粒体DNA损伤和释放，维持细胞内稳态。近年研究结果显示，慢性肝病的发生、发展与线粒体DNA介导的免疫炎症反应、氧化应激均密切相关。

简介：目的探讨泛昔洛韦联合干扰素γ抗乙型肝炎病毒（HBV）的作用。方法将65例慢性乙型病毒性肝炎（CHB）患者、HBV携带者（ASC）以泛昔洛韦（250mg，每日3次）口服及干扰素γ（200万单位，隔日肌肉注射1次）治疗3个月（治疗组），并以42例采用干扰素α-2b治疗的患者为对照组，观察血清HBV—DNA载体量、e抗原（HbeAg）和表面抗原（HbsAg）含量的变化。有效病例继续治疗6个月，停药后随访1年。结果治疗后HBV—DNA载体量治疗组仅16．9％无变化，对照组42．8％无变化（P〈0．01）；阴转率治疗组为52．3％，对照组为28．6％（P〈0．05）；继续治疗6个月后阴转率治疗组为75．3％，对照组为52．4％（P〈0．01）；停药随访1年复发率治疗组为23．4％，对照组为22．7％（P〉0．05）。血清HbeAg及HbsAg含量治疗前两组无统计学差异，治疗后两组均有下降，治疗组下降幅度明显大于对照组（P〈0．01）。结论泛昔洛韦联合干扰素1抗病毒作用疗效优于对照组，干扰素1与其他抗病毒药物联用是有益的尝试。

简介：本文采用荧光定量PCR法对49例慢性乙型肝炎患者血清HBVDNA作定量检测,分析血清HBVDNA水平与疾病程度和HBV血清标志物(HBVM)的关系,探讨血清HBVDNA定量检测的临床意义。资料与方法一、检测对象参照1995年北京第五次全国传染病寄生虫病学术会议修订的诊断标准。慢性乙型肝炎49例,均存在肝功能异常,其中轻度19例、中度13例、重度17例。男42例,女7例。年龄18～78岁,平

简介：目的探讨老龄大鼠局灶性脑缺血周围DNA损伤特点.方法应用HE染色、原位末端标记法(TUNEL)标记、原位分子杂交、免疫组织化学等方法,分别对缺血4、24h和5d组大鼠脑组织中坏死细胞、凋亡细胞、p53mR.NA、p53蛋白阳性细胞密度及空间分布进行观察和比较.结果不同时间点病灶周围每高倍视野TUNEL、p53蛋白、p53mRNA的阳性细胞数分别为4h:8.0±1.5、25.1±2.6、10.3±1.9;24h:20.5±2.4、60.0±4.8、22.0±1.8;5d:2.1±0.4、3.6±1.4、3.5±0.8.p53基因主要在形态完整和可逆性损伤细胞中表达、分布范围较TUNEL细胞广泛.结论局灶性脑缺血后,缺血周围DNA损伤区大于凋亡区,p53基因表达范围可能代表病理意义上的半暗带;p53主要发挥DNA修复作用.

简介：摘要线粒体DNA（mitochondrial DNA，mtDNA）是特殊的遗传物质，具有母系遗传、高突变率、高拷贝数和无重组特性，广泛应用于进化遗传学、法医学和分子诊断等领域。对mtDNA遗传标记的研究可以反映一个群体的母系脉络特征，有助于推断群体的母系起源、分析迁移轨迹以及不同群体间的系统发育关系。本文将以达斡尔族为切入点，对达斡尔族人群mtDNA多样性作一综述；并追踪mtDNA遗传多样性在其他人群中的研究进展，为丰富中国人群的遗传信息资源提供重要资料。

简介：摘要目的探究分析男性少弱精子症不育患者精子DNA碎片检测情况。方法研究对象为我院2017年1月到10月期间收治的40例男性少弱精子症不育患者，将其作为观察组，同期选择健康体检的40名男性作为对照组，检测观察组和对照组人员的精液指标，并测定精子DNA碎片指数（DFI），分析DFI与精子密度、活动率、正常形态率以及前向活动精子之间的相关性。结果观察组患者DFI、精子密度、活动率、正常形态、前向活动精子等指标与对照组上述指标存在较大的差异性，存在统计学意义（P＜0.05）；DFI和精子密度、活动率、正常形态率以及前向活动精子之间呈负相关。结论男性少弱精子症不育患者精子DNA碎片与精子的相关指标呈负相关，表明男性少弱精子症不育患者的精子DNA完整性受到损伤，通过对DFI检测可作为男性生育能力评价的重要指标。

简介：摘要目的设计一种能够基于原有的分析数据、结合游离DNA片段大小及计数的新的分析方法。方法选取180例孕妇血样进行无创产前检测(non-invasive prenatal testing，NIPT)常规的高通量测序，探索游离DNA片段分子量大小与胎儿DNA含量的关系，提出一种新的结合游离DNA片段大小的Z值的算法。以羊水细胞染色体核型分析结果为金标准，比较两种算法的判断结果。结果当以150 bp为分割值时，小分子片段比例与胎儿DNA含量呈正相关。对高通量测序数据用新旧两种算法进行计算，发现基于计数的传统分析的敏感度为75.00%，特异度为98.86%；基于以150 bp为分割点的结合游离DNA片段大小及计数的分析敏感度和特异度在本次实验中都达到了100%。结论在结合游离DNA片段大小及计数的新方法中选取150 bp作为分子大小分割点，可能比传统基于计数的算法更为合理、有效。

简介：AIM:Toanalyzethemismatchrepair(MMR)statusandtheARID1Aexpressionaswellastheirclinicopathologicalsignificanceingastricadenocarcinomas.METHODS:WeexaminedtheexpressionsofMMRproteinsandARID1Abyimmunohistochemistryinconsecutive489primarygastricadenocarcinomas.Theresultswerefurthercorrelatedwithclinicopathologicalvariables.RESULTS:ThelossofanyMMRproteinexpression,indicativeofMMRdeficiency,wasobservedin38cases(7.8%)andwassignificantlyassociatedwithanolderage(68.6±9.2vs60.4±11.7,P<0.001),afemalesex(55.3%vs31.3%,P=0.004),anantrallocation(44.7%vs25.7%,P=0.021),andadifferentiatedhistology(57.9%vs39.7%,P=0.023).AbnormalARID1Aexpression,includingreducedorlossofARID1Aexpression,wasobservedin109cases(22.3%)andwassignificantlycorrelatedwithlymphaticinvasion(80.7%vs69.5%,P=0.022)andlymphnodemetastasis(83.5%vs73.7%,P=0.042).ThetumorswithabnormalARID1AexpressionmorefrequentlyindicatedMMRdeficiency(47.4%vs20.2%,P<0.001).AmultivariateanalysisidentifiedabnormalARID1Aexpressionasanindependentpoorprognosticfactor(HR=1.36,95%CI:1.01-1.84;P=0.040).CONCLUSION:OurobservationssuggestthattheAIRD1Ainactivationisassociatedwithlymphaticinvasion,lymphnodemetastasis,poorprognosis,andMMRdeficiencyingastricadenocarcinomas.

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简介：摘要电化学DNA传感器具有选择性好、灵敏度高、消耗低及简便易用等优点，能够对特征DNA序列进行快速准确的测定，因此电化学DNA传感器在食品安全检测、医学诊断和环境监测等领域都有广阔的应用前景。

简介：AbstractLung cancer is one of the leading causes of all cancer-related deaths. Circulating tumor DNA (ctDNA) is released from apoptotic and necrotic tumor cells. Several sensitive techniques have been invented and adapted to quantify ctDNA genomic alterations. Applications of ctDNA in lung cancer include early diagnosis and detection, prognosis prediction, detecting mutations and structural alterations, minimal residual disease, tumor mutational burden, and tumor evolution tracking. Compared to surgical biopsy and radiographic imaging, the advantages of ctDNA are that it is a non-invasive procedure, allows real-time monitoring, and has relatively high sensitivity and specificity. Given the massive research on non-small cell lung cancer, attention should be paid to small cell lung cancer.

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