Prognostic value of anti-ADAMTS 13 antibody features (Ig isotype, titer, and inhibitory effect) in a cohort of 35 adult French patients undergoing a first episode of thrombotic microangiopathy with undetectable ADAMTS 13 activity

To study both the pathophysiologic and the prognostic value of ADAMTS13 in thrombotic microangiopathies (TMAs), we enrolled a cohort of 35 adult patients combining a first acute episode of TMA, an undetectable (below 5%) ADAMTS13 activity in plasma, and no clinical background such as sepsis, cancer, HIV, and transplantation. All patients were treated by steroids and plasma exchange, and an 18-month follow-up was scheduled. Remission was obtained in 32 patients (91.4%), and 3 patients died (8.6%) after the first attack. At presentation, ADAMTS13 antigen was decreased in 32 patients (91.4%), an ADAMTS13 inhibitor was detectable in 31 patients (89%), and an anti-ADAMTS13 IgG/IgM/IgA was present in 33 patients (94%). The 3 decedent patients were characterized by the association of several anti-ADAMTS13 Ig isotypes, including very high IgA titers, while mortality was independent of the ADAMTS13 inhibitor titer. In survivors, ADAMTS13 activity in remission increased to levels above 15% in 19 patients (59%) but remained undetectable in 13 patients (41%). Six patients relapsed either once or twice (19%) during the follow-up. High levels of inhibitory anti-ADAMTS13 IgG at presentation were associated with the persistence of an undetectable ADAMTS13 activity in remission, the latter being predictive for relapses within an 18-month delay.     

头孢吡肟等抗生素对革兰阴性杆菌体外敏感性连续四年耐药性监测分析

目的监测和了解头孢吡肟对临床常见革兰阴性菌体外抗菌活性。方法从1999～2002年收集的临床常见革兰阴性杆菌50528株(主要为尿液、痰、伤口及其分泌物标本)，连续监测4年。药物敏感性试验采用纸片扩散法，WHONET5软件进行结果分析。结果1999～2002年头孢吡肟对肠杆菌科细菌的敏感性为70．0％-95．2％；对铜绿假单胞菌敏感性为73．9％-77．5％。1999-2002年肠杆菌科细菌临床分离株对头孢噻肟、头孢他啶和头孢吡肟耐药性变迁的比较表明，头孢吡肟耐药率增加幅度低于头孢噻肟、头孢他啶；铜绿假单胞菌对头孢吡肟耐药率增加幅度明显低于哌拉西林、阿米卡星和头孢他啶。结论头孢吡肟对大肠埃希菌、肺炎克雷伯菌、弗劳地枸橼酸杆菌、产气肠杆菌、阴沟肠杆菌、奇异变形杆菌、铜绿假单胞菌和鲍曼不动杆菌有较好的体外抗菌活性。     

Age-determined expression of priming protease TMPRSS2 and localization of SARS-CoV-2 in lung epithelium

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) novel coronavirus 2019 (COVID-19) global pandemic has led to millions of cases and hundreds of thousands of deaths. While older adults appear at high risk for severe disease, hospitalizations and deaths due to SARS-CoV-2 among children have been relatively rare. Integrating single-cell RNA sequencing (scRNA-seq) of developing mouse lung with temporally resolved immunofluorescence in mouse and human lung tissue, we found that expression of SARS-CoV-2 Spike protein primer TMPRSS2 was highest in ciliated cells and type I alveolar epithelial cells (AT1), and TMPRSS2 expression increased with aging in mice and humans. Analysis of autopsy tissue from fatal COVID-19 cases detected SARS-CoV-2 RNA most frequently in ciliated and secretory cells in airway epithelium and AT1 cells in peripheral lung. SARS-CoV-2 RNA was highly colocalized in cells expressing TMPRSS2. Together, these data demonstrate the cellular spectrum infected by SARS-CoV-2 in lung epithelium and suggest that developmental regulation of TMPRSS2 may underlie the relative protection of infants and children from severe respiratory illness.     

Salvianolic acid B modulates the expression of drug-metabolizing enzymes in HepG2 cells

BACKGROUND: Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GSTs). Herbs that inhibit CYPs such as CYP3A4 or that induce GSTs may have the potential to protect against chemical carcinogenesis since the mutagenic e...     

Titration of Newcastle disease virus and its neutralizing antibodies in microplates by a modified hemadsorption and hemadsorption inhibition method.

Using the microtiter system, titration of Newcastle disease virus infectivity and neutralizing antibodies was carried out in chicken embryo fibroblasts grown in "U" or flat-bottomed plates. Infectivity was detected by a combined hemadsorption-hemagglutination method. Inhibition of that reaction indicated the presence of neutralizing antibodies. A 24-h microneutralization test was developed and compared to the plaque neutralization and microhemagglutination inhibition test. Reproducibility of the microneutralization test was statistically analyzed.     

鱼腥草药材挥发油的指纹对照法研究

目的：建立鱼腥草药材中挥发油成分的指纹图谱,对各产地药材实现定性定量地评价,并对挥发油中主要成分进行鉴别。方法：采用气相色谱-氢离子火焰检测（GC-FID）技术测定不同产地的13批鱼腥草药材挥发油成分GC指纹图谱。以甲基正壬酮为对照品,以内标法估算各产地药材中各成分的相对含量,以夹角余弦和相对欧氏距离为参考指标进行评价;利用气相色谱-质谱-计算机检索技术（GC-MS-DS）对各色谱峰进行鉴别。结果：建立的鱼腥草药材挥发油成分指纹图谱确立23个共有峰,方法学考查显示各特征指纹峰保留相对稳定,经考察甲基正壬酮在6．6-660μg／ml内线性关系良好,经空白回收率校正后加样回收率为93．46％（n=6）。经鉴定识别其中24种主要成分。结论：建立的鱼腥草药材挥发油成分指纹图谱重复性好,综合了指纹对照法、定性和定量相似度,能更好地评价鱼腥草药材的质量。     

小单孢菌3',4'-双脱羟基酶基因功能的研究

根据文献查阅、同源比对及进化树分析,推测绛红色小单孢菌中gntI和伊纽小单孢菌sisI为3',4'-双脱羟基酶基因。通过克隆得到gntI和sisI,随后将其构建到pET30a表达载体,并在E.coli BL21实现异源表达。利用生物信息学对该蛋白亲水性图谱、空间结构及活性域进行分析、预测。基于同源建模得到三级结构,推测其二级结构以α-螺旋为主,肽段40～60,100～120处可能为该酶活性中心。此研究为该酶进一步功能研究和应用奠定了基础。     

痘苗病毒弱毒株广9株对动物的致病力研究

目的了解经痘苗病毒天坛株(VTT)3次挑斑纯化筛选出的痘苗病毒减毒株广9株(VG9)的神经毒性和致病性。方法对痘苗病毒VG9和其亲代病毒VTT进行小鼠和乳鼠及家兔脑内毒力测定、裸鼠腹腔毒力测定及家兔皮内反应性实验,并观察实验动物的发病率和死亡率及皮肤坏死情况。结果两株病毒对小鼠和乳鼠的脑内毒力(icLD50)值显示,VTT株较VG9株分别强约100倍和18倍;对家兔脑内的毒力虽然icLD50值显示两株病毒相同,但VTT致家兔发病的数量较VG9多,其50%发病剂量较VG9多32倍。家兔皮内接种病毒后,较低病毒滴度(6.63 lg PFU)的VTT接种点出现严重的皮肤坏死,而VG9仅在较高滴度(7.54 lg PFU)接种点皮肤出现轻微坏死。结论通过不同途径接种几种实验动物均显示VG9的毒力较其母株VTT明显减弱。可以预测VG9痘苗在人体可能产生的不良反应较VTT痘苗低,并且有可能比VTT更适合作为痘苗病毒载体应用于新的重组疫苗(如HIV疫苗)的研发。     

口腔局部使用干扰素对小鼠唾液SIgA的调节

目的 :了解干扰素对口腔粘膜分泌SIgA的调节作用。方法 :以生物素 -ELISA法检测口腔使用干扰素前后小鼠唾液SIgA的水平。结果 :大、小剂量干扰素组在用药后 10天、2 0天和 3 0天都能增高唾液SIgA ,并同对照组相比有显著差异 (P <0 0 5 ) ;大剂量组SIgA的增高更多 ,特别是在 2 0天时明显高于小剂量组 (P <0 0 5 ) ;干扰素的调节作用持续至少 3 0天 ,小剂量在维持作用方面不亚于大剂量。结论 :干扰素直接作用于口腔粘膜 ,可提高局部的SIgA的分泌水平。     

单克隆与多克隆双抗体夹心法测定可溶性白细胞介素2受体试剂盒的研制

采用抗白细胞介素2受体(IL-2R)的单克隆与多克隆抗体以及辣根过氧化物酶(HRP)标记的羊抗兔IgG,建立了高特异性及高灵敏度的双抗体夹心法测定可溶性白细胞介素2受体(sIL-2R)。结果,酶联免疫吸附试验(ELISA)测得兔抗人IL-2R多克隆抗体效价达1:10~4,免疫双向扩散法测得羊抗兔抗体效价高达1:256。本试剂盒检测sIL-2R的特异性强,灵敏度为100U/ml,在28C存放一年,稳定性不变。此方法操作简单,适用于临床和基础研究。