双重实时荧光PCR快速鉴别人参和西洋参＊

目的 建立一种能够快速鉴定人参和西洋参的双重实时荧光PCR方法。方法 通过对人参属及其近似种基因序列的分析比对，设计特异性的引物探针，建立双重实时荧光PCR检测方法。PCR反应体系为Premix Ex Taq （Probe qPCR） 10 μL，人参上下游引物各0.5 μL，西洋参上下游引物各0.3 μL，人参与西洋参特异性探针各0.4 μL，DNA模板2 μL，灭菌去离子水补至20 μL。反应条件为95℃预变性30 s；然后以95℃变性5 s，60℃退火延伸30 s进行40个循环。应用该方法测试了27份DNA样品，包括7份人参、6份西洋参、4份人参与西洋参混合样、10份其他人参属样品及其他常见中药材样品的DNA，以确定该方法的特异性。将人参与西洋参样品DNA混合后10倍稀释成不同浓度后进行检测，用以确定该方法的灵敏度。结果 人参及西洋参样品均在特定的荧光通道下出现典型的阳性扩增曲线，人参与西洋参混合样品均同时出现两条阳性扩增曲线，其它对照样品及空白对照均没有出现阳性扩增曲线。灵敏度检测结果显示该方法检测人参及西洋参的最低检测限均为2 pg DNA/反应。结论 本实验建立的双重实时荧光PCR方法能够同时快速、准确、灵敏地鉴别出人参和西洋参。     

程序性死亡受体1和程序性死亡受体配体1在非小细胞肺癌组织中的表达情况及临床意义

目的探讨程序性死亡受体1(PD-1)和程序性死亡受体配体1(PD-L1)在非小细胞肺癌(NSCLC)组织中的表达情况及临床意义。方法选择150例NSCLC患者的NSCLC组织及其癌旁组织,采用实时荧光定量聚合酶链反应(PCR)检测两种组织中PD-1 mRNA和PD-L1 mRNA的相对表达量。采用免疫组织化学染色法检测NSCLC组织中PD-1和PD-L1的表达情况,分析PD-1和PD-L1表达情况与患者临床特征的关系。采用流式细胞术检测NSCLC组织和癌旁组织中CD4^+-PD-1、CD8^+-PD-1、CD14^+-PD-L1、CD68^+-PD-L1的表达水平。结果NSCLC组织中PD-1 mRNA和PD-L1 mRNA的相对表达量分别为(5.03±1.92)和(4.95±1.09),分别高于癌旁组织的(1.72±0.81)和(1.25±0.24),差异均有统计学意义(P﹤0.05)。TNM分期为Ⅲ~Ⅳ期、低分化、有淋巴结转移、有远处转移的NSCLC患者NSCLC组织中PD-1和PD-L1的高表达率均明显高于TNM分期为Ⅰ~Ⅱ期、高+中分化、无淋巴结转移、无远处转移的患者,差异均有统计学意义(P﹤0.01)。NSCLC组织中CD4^+-PD-1、CD8^+-PD-1、CD14^+-PD-L1、CD68^+-PD-L1的表达水平均明显高于癌旁组织,差异均有统计学意义(P﹤0.01)。结论PD-1和PD-L1在NSCLC组织中高表达,可能成为一种新的生物标志物,PD-1/PD-L1信号通路可能参与了NSCLC的免疫逃逸过程,对其逃逸机制进行研究可以为NSCLC患者的临床治疗提供新靶点。     

移动医生查房系统临床实施应用研究

结合陆军军医大学第一附属医院移动医护信息化建设实践，介绍移动查房系统软件架构、网络架构、具体功能及应用优势，指出该系统可实现患者临床信息实时更新和共享，有助于提高医护人员临床决策响应能力和工作效率。     

基于线粒体COⅠ基因的广西不同地区福寿螺遗传多态性分析

目的 通过对广西不同地区福寿螺的COⅠ基因进行分析,以了解广西福寿螺种群的遗传多态性。方法 从南宁市横县、桂林市全州县和荔浦县、贺州市富川县、百色市田林县和崇左市凭祥县共计6个县区采集福寿螺样本,提取DNA并进行COⅠ基因的PCR扩增及测序。运用MAGE 7.0将本研究获得的单倍型与GenBank中的福寿螺单倍型使用邻接法构建系统进化树,并计算个体间的遗传距离,分析其遗传多样性。结果 COⅠ基因长度为493 bp,从11个样本鉴定出2种单倍型：单倍型1（Haplotype 1）和单倍型2（Haplotype 2）。其中9个样本为Haplotype 1,分别来源于南宁市横县（2个）、贺州市富川县（1个）、桂林市荔浦县（1个）、百色市田林县（2个）、崇左市凭祥县（3个）,该单倍型与小管福寿螺遗传距离最近,为0.047;2个样本为Haplotype 2,分别源自为南宁市横县和桂林市全州,与孤岛福寿螺遗传距离最近,为0.062。根据上述条件所构建的进化树形成了7个分支,分别为P. canaliculata、P. camena、P. insularum、P. paludosa、P. diffusa、P. haustrum、和外群Pilaconica。Haplotype 1与来自美国夏威夷 （GenBank登录号 EU 523129）的P. canaliculata组成一个分支,Haplotype 2与来自巴西（GenBank登录号EF514942）的P. insularum组成一个分支,且置信值均在98%以上。结论 初步判断广西地区存在小管福寿螺与孤岛福寿螺两种类型的福寿螺,其种群内没有发现遗传分化。     

Reopening schools in the context of increasing COVID-19 community transmission: The French experience

Background and objectivesThe role of schools in the spread of SARS-CoV-2 infections in the community is still controversial. The objective of our study was to describe the epidemiology of SARS-CoV-2 infections in different pediatric age groups during the first 2 months of the fall back-to-school period, in the context of increasing viral transmission in France.MethodsWeekly epidemiological data provided by Santé Publique France and the Ministry of National Education were analyzed according to the age groups defined by the different school levels. Weeks (W) 34–42 were considered for analysis.ResultsThe PCR positivity rate and incidence rate increased in all age groups during the study period, in an age-dependent manner. At W42, with adults being considered as reference, the risk ratio for a positive PCR test was 0.46 [95% CI: 0.44–0.49] and 0.69 [0.68–0.70] for children aged 0–5 years and 6–17 years, respectively. Similarly, the incidence rate ratio was 0.09 [0.08–0.09], 0.31 [0.30–0.32], 0.64 [0.63–0.66], and 1.07 [1.05–1.10] for children aged 0–5 years, 6–10 years, 11–14 years, and 15–17 years, respectively. Children and adolescents accounted for 1.9% of the newly hospitalized patients between W34 and W42, and for 1.3% of new intensive care admissions. No death was observed. Among infected children and adolescents, the percentage of asymptomatic individuals was 57% at W34 and 48% at W42. The number of schools closed remained low, less than 1% throughout the study period. The number of confirmed cases among school staff was consistent with the data measured in the general population.ConclusionIn the context of increasing viral transmission in the population, the spread among children and adolescents remained lower than that observed among adults, despite keeping schools open. However, the impact was age-dependent, with data in high schools close to those observed in adults.     

The Viral Load of Epstein-Barr Virus in Blood of Children after Hematopoietic Stem Cell Transplantation

ObjectiveTo detect the Epstein-Barr virus (EBV) viral load of children after hematopoietic stem cell transplantation (HSCT) using chip digital PCR (cdPCR).MethodsThe sensitivity of cdPCR was determined using EBV plasmids and the EBV B95-8 strain. The specificity of EBV cdPCR was evaluated using the EBV B95-8 strain and other herpesviruses (herpes simplex virus 1, herpes simplex virus 2, varicella zoster virus, human cytomegalovirus, human herpesvirus 6, and human herpesvirus 7). From May 2019 to September 2020, 64 serum samples of children following HSCT were collected. EBV infection and the viral load of serum samples were detected by cdPCR. The epidemiological characteristics of EBV infections were analyzed in HSCT patients.ResultsThe limit of detection of EBV cdPCR was 110 copies/mL, and the limit of detection of EBV quantitative PCR was 327 copies/mL for the pUC57-BALF5 plasmid. The result of EBV cdPCR was up to 121 copies/mL in the EBV B95-8 strain, and both were more sensitive than that of quantitative PCR. Using cdPCR, the incidence of EBV infection was 18.75% in 64 children after HSCT. The minimum EBV viral load was 140 copies/mL, and the maximum viral load was 3,209 copies/mL using cdPCR. The average hospital stay of children with EBV infection (184 ± 91 days) was longer than that of children without EBV infection (125 ± 79 days), P = 0.026.ConclusionEBV cdPCR had good sensitivity and specificity. The incidence of EBV infection was 18.75% in 64 children after HSCT from May 2019 to September 2020. EBV cdPCR could therefore be a novel method to detect EBV viral load in children after HSCT.