DNA损伤在衰老相关疾病中的研究进展

DNA损伤是衰老相关疾病领域的研究热点, 可引起细胞周期停滞、凋亡, 加快个体衰老速度、增加衰老相关疾病的患病风险。本文将从细胞衰老和个体衰老两个层面阐述其与衰老之间的研究进展, 并综述其与衰老常见相关疾病(肿瘤、心血管疾病、阿尔茨海默病)及早衰综合征的关系, 为抗衰老研究和临床干预衰老相关疾病提供理论依据。     

Evaluation of the MHSeqTyper47 kit for forensically challenging DNA samples

Microhaplotypes have been highly regarded for forensic mixture DNA deconvolution because they do not experience interference from stutters in the same way as short tandem repeat markers, and they tend to be more polymorphic than single nucleotide polymorphism markers. However, forensic microhaplotype kits have not been reported. The MHSeqTyper47 kit genotypes 47 microhaplotype loci. In this study, MiSeq FGx sequencing metrics for MHSeqTyper47 were presented, and the genotyping accuracy of this kit was examined. The sensitivity of MHSeqTyper47 reached 62.5 pg, and full genotyping results were obtained from degraded DNA samples with degradation indexes ≤ 3.00. Full genotypes were obtained in the presence of 100 ng/μL tannin, 50 μM heme, 25 ng/μL humic acid, and 1.25 μg/μL indigo dye. In DNA mixture studies, a minimum of 31 loci of the minor contributor were correctly genotyped at 1:99 or 99:1 mixing ratios, with the cumulative random matching probability of these loci reaching 4.54 × 10⁻²⁵. Mixing ratios could be reliably predicted from two-donor DNA mixtures based on the loci with four called alleles. Taken together, these data showed that the MHSeqTyper47 kit was effective for forensically challenging DNA analysis.     

多发性骨髓瘤中表观遗传学修饰的研究进展北大核心

多发性骨髓瘤(multiple myeloma,MM)是一种病因不明,目前仍无法治愈的恶性血液系统性疾病。研究显示MM是一种复杂的表观遗传学修饰所驱动的恶性肿瘤,表观遗传学修饰是改变MM发病进展的重要机制,并影响治疗及预后。本文将对表观遗传学异常调控在MM的发生发展过程中的作用及相关耐药机制和治疗的现状进行综述。     

二维斑点追踪显像技术评估窒息新生儿左心室纵向收缩功能与心肌损害的相关性

【摘要】目的 探讨二维斑点追踪显像技术(2D-STI)评估新生儿窒息合并心肌损害后左心室整体及局部心肌的纵向收缩功能在早期诊断窒息新生儿心肌损害中的临床价值。方法 选择2019年07月至2020年12月期间在右江民族医学院附属医院新生儿科住院的足月窒息新生儿61例，经临床确诊合并心肌损害，根据Apgar评分分为轻度组31例和重度组30例，选择同期住院出生的正常足月新生儿30例作为对照组。检测受检者的血清肌酸激酶同工酶（CK-MB）、肌钙蛋白（cTnT）、左室舒张期前后径（LVDId）、左室射血分数（LVEF）、左室短轴缩短率（LVFS）、辛普森法左室射血分数（Simpson EF）、左室三腔心整体应变（GLS-LAX）、左室四腔心整体应变（GLS-A4C）、左室两腔心整体应变（GLS-A2C）、左室整体应变（GLS-AVG）,分析GLS-AVG和CK-MB、cTnT三者的相关性。结果 三组间CK-MB和cTnT比较差异有统计学意义（P<0.05）。三组间性别、体重、胎龄均无统计学差异（P>0.05）。三组间LVDId、LVEF、LVFS、Simpson EF比较差异无统计学意义（P>0.05）。GLS-AVG与CK-MB呈负性相关（r=-0.515，P=0.000），GLS-AVG与cTnT呈负性相关（r=-0.912，P=0.000）。结论 GLS-AVG与CK-MB、cTnT具有相关性，GLS-AVG可作为窒息新生儿心肌损害早期诊断指标。     

Validation of donor fraction cell-free DNA with biopsy-proven cardiac allograft rejection in children and adults

ObjectivesDonor-specific cell-free DNA shows promise as a noninvasive marker for allograft rejection, but as yet has not been validated in both adult and pediatric recipients. The study objective was to validate donor fraction cell-free DNA as a noninvasive test to assess for risk of acute cellular rejection and antibody-mediated rejection after heart transplantation in pediatric and adult recipients.MethodsPediatric and adult heart transplant recipients were enrolled from 7 participating sites and followed for 12 months or more with plasma samples collected immediately before all endomyocardial biopsies. Donor fraction cell-free DNA was extracted, and quantitative genotyping was performed. Blinded donor fraction cell-free DNA and clinical data were analyzed and compared with a previously determined threshold of 0.14%. Sensitivity, specificity, negative predictive value, positive predictive value, and receiver operating characteristic curves were calculated.ResultsA total of 987 samples from 144 subjects were collected. After applying predefined clinical and technical exclusions, 745 samples from 130 subjects produced 54 rejection samples associated with the composite outcome of acute cellular rejection grade 2R or greater and pathologic antibody-mediated rejection 2 or greater and 323 healthy samples. For all participants, donor fraction cell-free DNA at a threshold of 0.14% had a sensitivity of 67%, a specificity of 79%, a positive predictive value of 34%, and a negative predictive value of 94% with an area under the curve of 0.78 for detecting rejection. When analyzed independently, these results held true for both pediatric and adult cohorts at the same threshold of 0.14% (negative predictive value 92% and 95%, respectively).ConclusionsDonor fraction cell-free DNA at a threshold of 0.14% can be used to assess for risk of rejection after heart transplantation in both pediatric and adult patients with excellent negative predictive value.     

The impact of the covalently closed circular DNA level on recurrence of hepatocellular carcinoma after initial hepatectomy: an analysis of patients with resolved hepatitis B virus infection

BackgroundWe assessed whether or not covalently closed circular DNA (cccDNA) levels in the background liver influence the recurrence of hepatocellular carcinoma (HCC) in patients with resolved hepatitis B virus (HBV) infection.MethodsAmong 425 patients who underwent initial hepatectomy for HCC between 2010 and 2018, a retrospective review was performed in 44 with resolved HBV infection. The clinicopathologic characteristics were analyzed for correlation with tumor recurrence. The HBV cccDNA levels were tested via a droplet digital polymerase chain reaction assay.ResultsHBV cccDNA was detected in 27 of 44 patients (61%), and the median level was 1.0 copies/1000 ng (range, 0-931.3 copies/1000 ng). Anti-HBc ≥8.9 S/CO was associated with cccDNA detection (odds ratio, 11.08; 95% confidence interval [95% CI], 2.48-49.46; P = 0.002). Twenty-eight patients (64%) developed HCC recurrence after hepatectomy. The overall 3- and 5-year recurrence-free survival rates were 45.7% and 34.3%, respectively.19 HBV cccDNA levels was not significantly associated with HCC recurrence, while the presence of multiple tumors was an independent risk fact or (hazard ratio, 6.53; 95% CI, 2.48-17.19; P < 0.001.ConclusionHBV cccDNA levels did not influence HCC recurrence after hepatectomy. Anti-HBc levels may be used as a surrogate marker for cccDNA.     

尿酸性肾病中医分型与氧化应激指标的相关性研究

目的：探讨尿酸性肾病中医分型与氧化应激相关性。方法：采用回顾性分析方法对2017年12月至2019年9月北京中医药大学第三附属医院收治的尿酸性肾病患者105例进行研究，选择同时期正常健康者105例作为对照，参考《中药新药临床研究指导原则》将105例尿酸性肾病和临床常见证型相结合，分成脾肾气虚18例、气阴两虚证19例、肝肾阴虚16例、阴阳两虚12例、湿热蕴结19例、瘀血阻滞17例、痰浊内阻13例，均在入院次日清晨空腹抽取静脉血，检测氧化应激氧化应激、肾功能损害指标，比较不同组别在氧化应激指标含量水平变化情况，比较中医分型和氧化应激、肾功能损害指标水平变化。结果：1）尿酸性肾病组总抗氧化能力（T-ACO）、晚期蛋白氧化物（AOPP）、血清丙二醇（MDA）、超氧化物歧化酶（SOD）含量水平分别为（19.45±3.42）U/mL、（42.45±3.53）μmol/L、（4.52±1.23）nmol/L、（76.78±5.64）U/mL，正常对照组则分别为（10.76±1.31）U/mL、（20.84±1.28）μmol/L、（2.13±0.76）nmol/L、（130.85±16.75）U/mL，尿酸性肾病组T-ACO、AOPP、MDA较正常对照组显著偏高，SOD显著偏低（P<0.05）。2）虚证中阴阳两虚证SOD含量上较其他证型均偏低，而MDA、T-AOC、AOPP、胱抑素C（CysC）、β2微球蛋白、尿微量白蛋白（UMALB）、蛋白尿发生率则较其他证型均偏高，差异均有统计学意义（P<0.05），实证中瘀血阻滞证SOD含量较其他证型均偏低，而MDA、T-AOC、AOPP则较其他证型均偏高，差异均有统计学意义（P<0.05）。结论：尿酸性肾病中医分型的阴阳两虚证、瘀血阻滞证氧化应激水平、肾损害指标均显著升高，可结合该实验室检查进行临床干预。