Use of sodA sequencing for the identification of clinical isolates of coagulase-negative staphylococci

This study evaluated the possible advantages provided by a genotypic method over commercially available biochemical systems for the identification of clinical isolates of coagulase-negative staphylococci (CNS). Partial sequencing of the sodA gene was performed for 168 coagulase-negative clinical isolates of staphylococci identified previously with the ID32 STAPH system. Of these, 101 (60.1%) were identified to the species level with ID32 STAPH, while 67 (39.9%) were misidentified or not identified with certainty. Sequencing of sodA proved useful for resolving all ambiguities or inconclusive identifications generated by the commercially available biochemical identification system.     

巨噬细胞移动抑制因子提高鼻咽癌细胞体外侵袭能力

目的　研究巨噬细胞移动抑制因子 (MIF)体外提高鼻咽癌细胞侵袭能力的原因 ,探讨鼻咽癌细胞早期发生侵袭和转移的机制。方法　采用微孔迁移分析法 (micron migrationassay)检测鼻咽癌细胞株CNE 1、CNE 2在细胞因子MIF诱导下通过 8μm直径微孔的细胞数量变化 ,采用Western蛋白印迹法、流式细胞术和酶联免疫吸附法检测侵袭转移相关因子基质金属蛋白酶 2、9(MMP2 ,MMP9)及白介素 8(IL 8)在此过程中的相应改变。结果　 (1)经MIF诱导后 ,CNE 1通过 8μm微孔的细胞数由原来的 2 3 7± 11 0 2增加至 113 7± 2 0 9,CNE 2则由原来的 3 4 7± 7 41增加至 3 11 3± 48 9,差异均呈显著性 (P =0 0 0 5,P =0 0 0 1)。 (2 )经MIF诱导后 ,癌细胞表达MMP9蛋白的细胞比例均明显增加 ,CNE 1细胞由 2 8 5%± 2 45%增加至 82 4%± 3 49% (P =0 0 0 1) ,而CNE 2细胞则由刺激前的 3 2 8%± 3 48%增加至 86 1%± 1 62 % (P =0 0 0 2 )。同时癌细胞MMP9蛋白表达强度也显著增强 ,CNE 1和CNE 2细胞MMP9蛋白的平均相对强度均比诱导前提高 3倍以上 (P <0 0 5)。但MIF刺激前后 ,MMP2蛋白的细胞表达数量和表达强度在两株细胞中却未见明显变化 (P值均大于 0 0 5)。 (3 )MIF诱导后 ,CNE 2细胞培养上清液中的IL 8浓度为 12     

利用噬菌体肽库筛选抗黏附的活性多肽

目的 :筛选抗内皮细胞与单核细胞黏附的活性多肽。方法 :①以氧化型低密度脂蛋白 (ox LDL ,10 0mg/L)损伤的内皮细胞作为筛选的“靶”细胞 ,从XCX15肽文库 (X代表随机氨基酸 ,C为半胱氨酸 ,X15代表编码随机 15肽 )中 ,筛选能与受损内皮细胞特异性结合的多肽。②用ELISA法鉴定部分阳性克隆 ,经DNA序列测定确定其插入的氨基酸序列。③以计数法检测特异性噬菌体多肽对内皮细胞与单核细胞黏附率的影响。结果 :①从挑选鉴定的 14个克隆中 ,得到 6个阳性克隆 ,测序结果有两个克隆的外源多肽序列相同 ,4个克隆的外源多肽中含有亮氨酸 亮氨酸重复序列。②两个序列相同的克隆的噬菌体多肽 ,能明显降低内皮细胞与单核细胞的黏附率(分别降低 17.0 %和 17.6 % ,P <0 .0 1,n =4 )。结论 :从XCX15肽文库中 ,初步鉴定出 1个具有较明显地抗内皮细胞与单核细胞黏附作用的活性多肽     

抗广州管圆线虫噬菌体抗体库的构建及初步筛选

目的以广州管圆线虫感染的小鼠脾细胞为源,构建抗广州管圆线虫抗体库,并筛选可用于广州管圆线虫病早期诊断的目的抗体。方法提取感染广州管圆线虫的小鼠脾细胞RNA,并逆转录合成cDNA第一链,PCR扩增出抗体轻链和重链基因,将轻、重链基因先后连接到表达载体pComb3上,转化大肠杆菌XLI-Blue,构建组合文库。用广州管圆线虫排泄分泌抗原（EsAg）作为筛选抗原,进行富集筛选,用ELISA法鉴定阳性克隆。结果成功构建了小鼠抗广州管圆线虫噬菌体抗体文库,库容为2.32×106,滴度为1.7×1013cfu/ml。筛选到了抗广州管圆线虫排泄分泌抗原特异性抗体克隆5株,用过氧化物酶标记的抗M13抗体进行初步鉴定,具有一定的特异性。结论构建的抗广州管圆线虫噬菌体抗体库达到了要求,为研制广州管圆线虫金标诊断试剂盒奠定了基础。     

抗人CD20纳米抗体的筛选、表达及特性分析

目的 筛选出抗人CD20纳米抗体序列,并获得具有高亲和力与特异性的抗CD20-人IgG Fc纳米抗体.方法 利用天然噬菌体纳米抗体库,以生物素化的CD20抗原为靶标进行4轮液相亲和筛选,采用ELISA鉴定阳性克隆;将筛选到的阳性克隆基因序列与人IgG Fc片段偶联,构建到原核表达载体pCZN1中,并转化至大肠杆菌Arc...     

血清IL-32、IL-33、IL-35在不同亚型Hp感染者及胃癌患者中的水平及意义

目的 观察血清白细胞介素-32(interleukin-32,IL-32)、白细胞介素-33(interleukin-33,IL-33)、白细胞介素-35(interleukin-35,IL-35)水平与不同亚型幽门螺杆菌(Helicobacter pylori,Hp)感染之间的关系,并探讨胃癌患者血清IL-32、IL...     

Preparations of intravenous immunoglobulins diminish the number and proinflammatory response of CD14+CD16++ monocytes in common variable immunodeficiency (CVID) patients

We have studied the effect of intravenous immunoglobulins (IVIG) on monocyte subpopulations and cytokine production in patients with CVID. The absolute number of CD14(+)CD16(++) monocytes decreased on average 2.5-fold 4h after IVIG and after 20h returned to the baseline. The cytokine level in the supernatants of peripheral blood mononuclear cells (PBMC) after ex vivo LPS stimulation demonstrated the >2-fold decrease in TNF production 4h after IVIG. The TNF expression, which is higher in the CD14(+)CD16(++) monocytes, was decreased in these cells by IVIG in 4/7 CVID cases. In vitro exposure of the healthy individuals' monocytes to the IVIG preparation resulted in reduced TNF production, which was overcome by blockade of the FcγRIIB in the CD14(+)CD16(++) CD32B(high) monocytes. Our data suggest that reduction in the number of CD14(+)CD16(++) monocytes and the blockade of their cytokine production via triggering CD32B can contribute to the anti-inflammatory action of IVIG.     

Isolation,production, and characterization of a new single chain anti-idiotypic antibody against benzo[a]pyrene

Polycyclic aromatic hydrocarbons are chemical carcinogens which could induce the development of human cancers. Anti-idiotypic antibodies against benzo[a]pyrene (BP) are perspective for human cancer immunoprophylaxis and tumor immunodiagnostic techniques. The purpose of this study was to isolate anti-idiotypic antibodies against BP from human lymphocytes naïve phage library. The anti-idiotypic antibody, named B5, was selected. Analysis of the nucleotide and amino acid sequences B5 showed no similarity to known protein databases antibodies. B5 bound idiotypic antibodies against BP in direct and competitive ELISA. It was suggested that the B5 carried an immunological image of BP and bound the idiotypic antibodies against BP.

Abbreviations: scFv: single-chain variable fragment; Ab1: idiotypic antibodies; Ab2: anti-idiotypic antibodies; CBD: cellulose binding domain; BSA: bovine serum albumin; PBS: phosphate buffer; BP-BSA: benzo[a]pyrene-BSA conjugate; Cr-BSA: chrysene-BSA conjugate; Py-BSA: pyrene-BSA conjugate; Ac-BSA: anthracene-BSA conjugate; Ba-BSA: benz[a]anthracene-BSA conjugate; PAH: polycyclic aromatic hydrocarbons; pSh: mouse idiotypic single-chain variable fragment against benzo[a]pyrene; T72: human idiotypic single-chain variable fragment against benzo[a]pyrene.     

IL-32与肿瘤生物学行为

肿瘤是威胁人类健康的重大疾病,其进程与肿瘤微环境密切相关。炎性介质是肿瘤微环境的重要组分, IL?32是一种炎性因子,主要由免疫细胞及上皮细胞表达,目前共发现IL?32α、β、γ、δ、ε、η、s、θ、ζ9种亚型。 IL?32可诱导IL?6、 IL?8、 IL1β等介质的表达,参与炎性疾病的进程,还可以通过NF?κB （核因子κB）、 MMP?2（基质蛋白酶2）等信号通路影响乳腺癌、宫颈癌、胃癌、肝癌等肿瘤的侵袭转移、增殖和凋亡。文章介绍了IL?32的发现、生物结构、分泌及其受体, IL?32在肿瘤微环境中的表达特点及其对肿瘤的生物学效应,旨在为IL?32的研究及肿瘤分子靶向治疗提供思路。