应用FITC系统建立非均衡竞争睾酮(T)化学发光法

目的 建立可广泛应用于睾酮(T)检测的方法.方法 制备辣根过氧化物酶(HRP)标记兔抗人T多克隆抗体及异硫氰酸荧光素(FITC)标记T-类似物.以抗FITC抗体包被发光板,FITC-T类似物与抗FITC抗体结合形成固相抗原,固相抗原与血清中T竞争结合抗T抗体-HRP,建立化学发光法(CLIA)血清T检测系统(FITC系统),进行方法 学评价,并与直接用T-牛血清清蛋白包被系统(非FITC系统)和罗氏公司Elecsys2010系统进行比较.结果 FITC系统检测线性范围为0.05~20 ng/mL,灵敏度为0.05 ng/mL;批内、批间变异系数均小于5%,优于非FITC系统;与Elecsys2010系统检测结果 的相关系数为0.973 2,测定结果 差异无统计学意义(P>0.05).结论 成功建立基于FITC系统的非均衡竞争T检测CLIA系统,精密度、灵敏度等指标均符合临床要求,可用于临床标本检测.     

Hydrogen sulfide protects colon cancer cells from chemopreventative agent β-phenylethyl isothiocyanate induced apoptosis

AIM: Hydrogen sulfide (H2S) is a prominent gaseous constituent of the gastrointestinal (GI) tract with known cytotoxic properties. Endogenous concentrations of H2S are reported to range between 0.2-3.4 mmol/L in the GI tract of mice and humans. Considering such high levels we speculate that, at non-toxic concentrations, H2S may interact with chemical agents and alter the response of colonic epithelium cells to such compounds. The GI tract is a major site for the absorption of phytochemical constituents such as isothiocyanates, flavonoids, and carotenoids, with each group having a role in the prevention of human diseases such as colon cancer. The chemopreventative properties of the phytochemical agent β-phenyethyl isothiocyanate (PEITC) are well recognized. However, little is currently known about the physiological or biochemical factors present in the GI tract that may influence the biological properties of ITCs. The current study was undertaken to determine the effects of H2S on PEITC mediated apoptosis in colon cancer cells.METHODS: Induction of apoptosis by PEITC in human colon cancer HCT116 cells was assessed using classic apoptotic markers namely SubG1 population analysis,caspase-3 like activity and nuclear fragmentation and condensation coupled with the MTT (3-(4,5-dimethylthiazol2-yl)-2,5-diphenyl tetrasodium bromide) viability assay and LDH leakage.RESULTS: PEITC significantly induced apoptosis in HGT116cells as assessed by SubG1 population formation, nuclear condensation, LDH leakage and caspase-3 activity after 24 h, these data being significant from control groups (P＜0.01). In contrast, co-treatment of cells with physiological concentrations of H2S (0.1-1 mmol/L) prevented PEITC mediated apoptosis as assessed using the parameters described.CONCLUSION: PEITC effectively induced cell death in the human adenocarcinoma cell line HCT116 in vitro through classic apoptotic mechanisms. However, in the presence of H2S, apoptosis was abolished. These data suggest that H2S may play a significant role in the response of colonic epithelial cells to beneficial as well as toxic agents present within the GI tract.     

Antibody producing human-human hybridomas. I. Technical aspects

Technical aspects of generation of antibody-secreting human-human hybridomas are evaluated as based on 100 human-human fusions with a human B-lymphoma cell line (RH-L4) or the SKO-007 myeloma cell line as malignant fusion partners, and compared with similar fusion conditions in the mouse hybridoma system. The yield of hybrids was significantly lower when normal peripheral blood lymphocytes were used as fusion partners as compared with spleen lymphocytes, but could be substantially improved by increasing the amount of mitotic active B-lymphocytes by mitogen stimulation of the lymphocytes, preferably in HAT medium, prior to fusion. Furthermore, human hybrids grew slower and had a higher degree of chromosomal instability than usually observed in the mouse hybridoma system. Thus, out of 72 fusions, only 3 stable hybrids with antibody production against a predefined antigen were established. The importance of improved sources of human B-lymphocytes for human-human hybridoma production is discussed and methods of obtaining such improvement suggested.     

Immunoassays at a quartz-liquid interface: theory, instrumentation and preliminary application to the fluorescent immunoassay of human immunoglobulin G

The theoretical basis and instrumental requirements of an optical detection technique for monitoring antibody-antigen reactions at a quartz-liquid interface are described. The antibody is covalently immobilized on the optical surface of a planar, fused-quartz waveguide and reacted with antigen solution. A light beam is internally reflected within the waveguide and penetrates into the solution only a fraction of the wavelength of the incident light. This is the evanescent wave which interacts optically with the growing number of antigen-antibody complexes but minimally with the bulk solution. A two-site immunofluorescent assay for human IgG measurement is described using fluorescein as the label. The assay detection limit is approximately 0.8 micrograms/ml and individual fluorescence measurements are completed within 10 min. It is expected that this evanescent wave immunoassay should have wide applicability in both routine and research fields.     

Candida albicans is an immunogen for anti-Saccharomyces cerevisiae antibody markers of Crohn's disease

BACKGROUND AND AIMS: Antibodies directed against oligomannose sequences alpha-1,3 Man (alpha-1,2 Man alpha-1,2 Man)(n) (n = 1 or 2), termed anti-Saccharomyces cerevisiae antibodies (ASCAs) are markers of Crohn's disease (CD). S. cerevisiae mannan, which expresses these haptens, is used to detect ASCA, but the exact immunogen for ASCA is unknown. Structural and genetic studies have shown that Candida albicans produces mannosyltransferase enzymes that can synthesize S cerevisiae oligomannose sequences depending on growth conditions. This study investigated whether C. albicans could act as an immunogen for ASCA. METHODS: Sequential sera were collected from patients with CD, systemic candidiasis, and rabbits infected with C. albicans. Antibodies were purified by using chemically synthesized (Sigma) ASCA major epitopes. These affinity-purified antibodies and lectins were then used to analyze the expression of ASCA epitopes on molecular extracts and cell walls of C. albicans and S cerevisiae grown in various conditions. RESULTS: In humans and rabbits, generation of ASCA was shown to be associated with the generation of anti-C. albicans antibodies resulting specifically from infection. By using affinity-purified antibodies, C. albicans was shown to express ASCA epitopes on mannoproteins similar to those of S. cerevisiae. By changing the growth conditions, C. albicans mannan was also able to mimic S. cerevisiae mannan in its ability to detect ASCA associated with CD. This overexpression of ASCA epitopes was achieved when C. albicans grew in human tissues. CONCLUSIONS: C. albicans is one of several immunogens for ASCA and may be at the origin of an aberrant immune response in CD.     

Effect of Gardenia extract ZG on the adsorption quantity of herpes simplex virus type 1 （HSV-1）

To observe the effect of Gardenia extract ZG on the adsorption quantity of herpes simplex virus type 1 (HSV-1) so as to explore the mechanism of its antiviral activity, fluorescein isothiocyanate (FITC) was used as the fluorescent probe to label viruses and heparin sodium was used as control. Meanwhile , the effect of Gardenia extract ZG on the adsorption quantity on the surface of Hep-2 cells was determined by flow cytometry. It was demonstrated that adsorption of HSV-1 on the surface of Hep-2 cells exhibited the character of saturation and specificity and heparin sodium could prevent attachment of viruses on these cells. These results are in accord with those reported previously. It was also proved that the manner of drug-use prior to adsorption or simultaneous use of drug and adsorption was better than adsorption prior to drug-use, and the inhibition rates of the former and latter manner were 84. 76% and 82.92% respectively. Three manners of drug-use with Gardenia extract ZG were all effective to reduce the adsorption quantity of viruses, especially the manner of simultaneous use of drug and adsorption with an adsorption inhibition rate of 68.46% . From the above observation, it is apparent that the mechanism of anti-viral activity of Gardenia extract ZG may be via several steps involved in the HSV-1 adsorption.     

小鼠抗兔IgG单克隆抗体的制备与应用

制备小鼠抗兔IgG的mAb,经标记HRP和FITC后,应用于ELISA、Western blot、免疫组织化学染色试验以及FCM.以正常兔IgG为抗原,免疫BALB/c小鼠,通过常规B淋巴细胞融合技术,获得两株分泌抗兔IgG mAb的杂交瘤细胞株,间接ELISA腹水效价均达1 ×10-7,且亚类均为IgG1(κ).抗体经鉴定、纯化后,以改良的过碘酸钠法标记HRP,本室常规方法标记FITC.FITC标记的2A1 mAb的F/P值为4.1,2F11的F/P值为2.7.HRP标记抗体的效价和工作浓度分别:2A1为1:25600和1:3200,2F11为1:102400和1:25600.在相同工作浓度条件下,ELISA、Western blot的实验结果,HRP标记的2F11 mAb明显优于商品化抗兔pAb,而且,2A1和2F11mAb经标记后还可用于免疫组化和FCM,显示出很好的应用前景.     

Human mast cells present antigen to autologous CD4+ T cells

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Efficient differentiation of vascular endothelial cells from dermal-derived mesenchymal stem cells induced by endothelial cell lines conditioned medium

Objective

To directionally-differentiate dermis-derived mesenchymal stem cells (DMSCs) into vascular endothelial cells (VECs) in vitro, providing an experimental basis for studies on the pathogenesis and treatment of vascular diseases.