基于规律成簇的间隔短回文重复序列及其相关蛋白技术检测乙型肝炎病毒共价闭合环状DNA方法的建立

目的建立一种基于规律成簇的间隔短回文重复序列及其相关蛋白(CRISPR/Cas13a)的乙型肝炎病毒(HBV)共价闭合环状DNA(HBV cccDNA)检测方法。方法提取2017年6月至2020年10月于首都医科大学附属北京佑安医院就诊的4例乙型肝炎患者肝脏总DNA后,使用HindⅢ内切酶和质粒安全性ATP依赖DNA酶(PSAD)分别进行酶切;根据松弛环状DNA(rcDNA)和cccDNA的结构差异,设计特异性扩增HBV cccDNA的引物,对酶切后的产物进行滚环扩增(RCA)和PCR扩增;并筛选crRNA,建立基于CRISPR/Cas13a技术的HBV cccDNA检测新方法。结果利用α-1-抗胰蛋白酶(A1AT)和HBV表面抗原(HBsAg)引物对双重酶切后的产物进行扩增,验证产物中HBV基因组的存在;利用HBV cccDNA和HBV rcDNA引物对PSDA酶切后的产物扩增,验证了产物中只存在HBV cccDNA;利用RCA后的阳性样本作为模板梯度稀释,然后进行PCR扩增转录后使用CRISPR/Cas13a检测,计算出检测下限为10拷贝/μl。结论本研究建立了RCA-PCR-CRISPR-Cas13a的新型检测方法,可对HBV cccDNA进行高灵敏度和高特异性检测,为乙型肝炎患者抗病毒治疗评估、治疗终点的确定以及调整治疗方案提供了有效的监测手段。     

CD19+CD24hiCD38hi B细胞比例预测肝移植术后急性细胞性排斥反应发生的临床研究

目的分析肝移植术后受者外周血CD19⁺CD24^hiCD38^hi B细胞占单个核细胞比例变化情况及其与急性细胞性排斥反应(ACR)之间的关系。 方法回顾性分析2013年12月至2015年12月在浙江大学医学院附属第一医院接受心脏死亡器官捐献肝移植的80例成人受者临床资料，根据术后是否发生ACR，将受者分为ACR组(25例)和非ACR组(55例)。术前、术后各个时间点抽取参加研究者静脉血并分离外周血单个核细胞，加入异硫氰酸荧光素-单克隆鼠抗人CD19抗体、藻红蛋白-单克隆鼠抗人CD24抗体和别藻蓝蛋白-单克隆鼠抗人CD38抗体，流式细胞仪检测各组CD19⁺CD24^hiCD38^hi B细胞百分比。采用t检验和单因素方差分析比较正态分布计量资料，采用χ²检验比较计数资料，采用Kaplan-Meier法绘制受试者工作特征曲线(ROC曲线)。P<0.05为差异有统计学意义。 结果ACR组、非ACR组受者术前外周血平均CD19⁺CD24^hiCD38^hi B细胞比例分别为(3.13±0.91)%、(3.49±0.83)%，差异无统计学意义(t＝1.636，P>0.05)。ACR组术后发生ACR前外周血平均CD19⁺CD24^hiCD38^hi B细胞比例为(1.87±0.70)%。非ACR组受者术后3个月、6个月和1年外周血平均CD19⁺CD24^hiCD38^hi B细胞比例分别为(1.64±0.52)%、(1.63±0.56)%和(2.04±1.24)%，术后3、6个月平均值均低于术前和术后1年，差异均有统计学意义(P均<0.05)。ACR组受者发生ACR时外周血平均CD19⁺CD24^hiCD38^hi B细胞比例为(0.8±0.5)%，低于发生ACR前的平均水平(t＝5.752，P<0.05)，且低于非ACR组术后3个月、6个月和1年的平均水平(P<0.05)。ACR组受者接受抗排斥反应治疗后，CD19⁺CD24^hiCD38^hi B细胞比例也逐渐增加，ACR发生后7 d为(0.84±0.08)%，与ACR发生时相比差异无统计学意义(P>0.05)；而发生30 d后达(1.65±0.18)%，与ACR发生时相比差异有统计学意义(P<0.05)。当截断值为1.015%时，CD19⁺CD24^hiCD38^hi B细胞比例预测ACR发生的敏感度和特异度分别为0.786和0.702，ROC曲线下面积为0.775(95%CI: 0.671~0.879，P<0.05)。 结论CD19⁺CD24^hiCD38^hi B细胞比例下降与肝移植术后ACR反应发生有关，并可作为预测ACR发生的细胞标志物。     

Hepatotoxicity of cantharidin is associated with the altered bile acid metabolism

Cantharidin (CTD) is an effective antitumor agent. However, it exhibits significant hepatotoxicity, the mechanism of which remains unclear. In this study, biochemical and histopathological analyses complemented with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabolomic analysis of bile acids (BAs) were employed to investigate CTD-induced hepatotoxicity in rats. Sixteen male and female Sprague–Dawley rats were randomly divided into two groups: control and CTD (1.0 mg/kg) groups. Serum and liver samples were collected after 28 days of intervention. Biochemical, histopathological, and BA metabolomic analyses were performed for all samples. Further, the key biomarkers of CTD-induced hepatotoxicity were identified via multivariate and metabolic pathway analyses. In addition, metabolite–gene–enzyme network and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to identify the signaling pathways related to CTD-induced hepatotoxicity. The results revealed significantly increased levels of biochemical indices (alanine aminotransferase, aspartate aminotransferase, and total bile acid). Histopathological analysis revealed that the hepatocytes were damaged. Further, 20 endogenous BAs were quantitated via UHPLC-MS/MS, and multivariate and metabolic pathway analyses of BAs revealed that hyocholic acid, cholic acid, and chenodeoxycholic acid were the key biomarkers of CTD-induced hepatotoxicity. Meanwhile, primary and secondary BA biosynthesis and taurine and hypotaurine metabolism were found to be associated with the mechanism by which CTD induced hepatotoxicity in rats. This study provides useful insights for research on the mechanism of CTD-induced hepatotoxicity.     

Biopsia selectiva de ganglio centinela en cáncer de mama, ¿está justificada la espera al resultado intraoperatorio?

IntroductionIn our institution, the study of selective sentinel node biopsy (SLNB) is performed intraoperatively. The main objective of our study is to know the proportion of patients who benefits from the waiting of the results of SLNB.MethodsA retrospective analysis of patients operated on our center between January 1 st, 2018 and June 30, 2019 was carried out. We included women diagnosed with T1–T2 tumors, treated by lumpectomy and SLNB studied using OSNA method.ResultsOur study included 149 women. There were not statistically significant differences in terms of demographic data between the group treated with axillary lymph node dissection (ALND) and exclusively SLNB group. After analysis of SLN intraoperatively, there were performed 18 axillary lymphadenectomies. Only in six of these 18 cases, three or more sentinel nodes were founded. The location of the tumor, the presence of lymphovascular permeation and the total tumor load (TTL) showed statistically significant differences between groups. Only the TTL was established as the independent factor of the need for ALND.ConclusionsObtaining a deferred result of the SLNB allowed reducing the time of anesthesia and occupation of the operating room, since in a high percentage of cases an additional procedure is not performed.     

Hepatitis B and circadian rhythm of the liver

The circadian rhythm in humans is determined by the central clock located in the hypothalamus’s suprachiasmatic nucleus, and it synchronizes the peripheral clocks in other tissues. Circadian clock genes and clock-controlled genes exist in almost all cell types. They have an essential role in many physiological processes, including lipid metabolism in the liver, regulation of the immune system, and the severity of infections. In addition, circadian rhythm genes can stimulate the immune response of host cells to virus infection. Hepatitis B virus (HBV) infection is the leading cause of liver disease and liver cancer globally. HBV infection depends on the host cell, and hepatocyte circadian rhythm genes are associated with HBV replication, survival, and spread. The core circadian rhythm proteins, REV-ERB and brain and muscle ARNTL-like protein 1, have a crucial role in HBV replication in hepatocytes. In addition to influencing the virus’s life cycle, the circadian rhythm also affects the pharmacokinetics and efficacy of antiviral vaccines. Therefore, it is vital to apply antiviral therapy at the appropriate time of day to reduce toxicity and improve the effectiveness of antiviral treatment. For these reasons, understanding the role of the circadian rhythm in the regulation of HBV infection and host responses to the virus provides us with a new perspective of the interplay of the circadian rhythm and anti-HBV therapy. Therefore, this review emphasizes the importance of the circadian rhythm in HBV infection and the optimization of antiviral treatment based on the circadian rhythm-dependent immune response.     

同型半胱氨酸、维生素D、C、E、B12及叶酸与胃癌关系的研究进展北大核心

胃癌作为临床最常见的肿瘤之一,常因确诊疾病较晚而影响治疗效果,胃镜活检后的病理虽然作为确诊的金标准,但是由于此方式过程痛苦,操作复杂,费用较高,且具有侵入性,可能会导致患者拒绝操作而难普及于临床,因此积极找寻胃癌有效的监测指标十分必要。近年来,很多学者研究维生素与胃癌的相关关系,并试图通过摄取某些维生素降低胃癌发生率,延缓病情及改善预后,也有通过检测血清中维生素的水平给早期胃癌的诊断提供帮助。本文就同型半胱氨酸、维生素D、维生素C、维生素E、维生素B12及叶酸在胃癌中的作用机制,及其在血清中水平与胃癌关系的相关研究进展进行简要综述,为临床胃癌诊疗提供新思路。