聚苯乙烯活性膜免疫电极的研究

用离子选择电极测定无机离子,既简便又快速.由此发展起来的酶电极,可以测定与酶促反应有关的低分子有机化合物,近来,免疫电极的研究引起人们的兴趣.免疫电极的基本原理是把抗体或抗原固定在特制的电极上,由于电极上的抗体或抗原与溶液中对应的配体相互作用,结果引起电极电位发生变化.从电极电位的变化量反映溶液中抗体或抗原的含     

纤维素载体的酶免疫测定技术

纤维素载体的酶免疫测定技术黎皓（北京生化免疫制剂中心开发室）程伯鲲（中国预防医科院流研所微生物室）自１９６６年Ｎａｋａｎｅ建立酶标记抗体技术以来,酶免疫测定技术（ＥｎｚｙｍｅＩｍｍｕｎｏａｓ－ｓａｙｓ,ＥＩＡ）在很多领域得到广泛应用,被认为是继放射免疫测定技术（ＲＩＡ）和荧光免疫测定技术（ＩＦＡ）之后的一项重要的免疫测定技术。其原理是通过化学方法将酶与抗体（或抗原）结合起来,酶标记后的抗体（或抗原）仍然保持与相应抗原（或抗体）相结合的免疫学活性以及酶的催化活性, 酶标记抗体与抗原结合后, 形成酶标抗体一抗原复合物。     

聚苯乙烯活性膜免疫电极的研究

用离子选择电极测定无机离子,既简便又快速。由此发展起来的酶电极,可以测定与酶促反应有关的低分子有机化合物,近来,免疫电极的研究引起人们的兴趣。免疫电极的基本原理是把抗体或抗原固定在特制的电极上,由于电极上的抗体或抗原与溶液中对应的配体相互作用,结果引起电极电位发生变化。从电极电位的变化量反映溶液中抗体或抗原的含量。Solsky等人用离子载体二苯并-18-王冠     

萤火虫荧光素酶单克隆抗体的制备与抗原决定簇的研究

以大肠杆菌表达的萤火虫荧光素酶 (fireflyluciferase)为抗原 ,免疫小鼠并进一步筛选与克隆 ,共得到 6株单克隆抗体 .制备腹水并纯化获得抗体后 ,对这 6株抗体与天然态和热变性态蛋白质以及蛋白酶解片段的结合性质进行了鉴定 .认为这 6株抗体的抗原决定簇都是顺序决定簇 .发现其中有 2株单抗与热变性态蛋白质及酶解片段的结合能力较强 ,而不与天然态蛋白质结合 ,其抗原决定簇可能是位于蛋白质内部的肽段 .另外 4株抗体既可与热变性态蛋白质以及酶解片段结合 ,也可与天然态蛋白质结合 ,其抗原决定簇可能位于蛋白质分子表面 .     

重组大肠杆菌菌蜕与幽门螺杆菌蛋白质疫苗协同免疫BALB/c小鼠

目的:考察重组菌蜕和蛋白质疫苗混合后对BAB/c小鼠机体免疫反应的影响。方法:首先构建展示尿素酶B抗原表位的大肠杆菌菌蜕,同时通过融合PCR构建分子内佐剂蛋白质疫苗rLTBKAT,然后分别利用该菌蜕和蛋白质疫苗免疫BAB/c小鼠。结果:当rLTBKAT和重组菌蜕联合口服免疫BAB/c小鼠时,其抗尿素酶B抗体的效价由单独免疫时的1∶(239±23)提高到1∶(681±76),二者差异极显著(P=0.009);而其抗过氧化氢酶抗体的效价则由单独免疫时的1∶(2800±275)下降至1∶(1800±400),二者差异不显著(P=0.08)。抗体分型试验表明,单独和联合免疫时,其抗尿素酶B抗体类型均以IgG1为主,而抗过氧化氢酶抗体类型则由单独免疫时的IgG1为主转变为联合免疫时的IgG2a为主。联合免疫时,小鼠抗尿素酶B和抗过氧化氢酶IgA抗体水平均高于单独免疫时。结论:重组菌蜕和蛋白质疫苗联合免疫,可提高机体对某些抗原的免疫水平或改变其反应类型。     

中华鳖对温和气单胞菌体液免疫应答规律的研究

从健康中华鳖血清中提取抗体并用Sephadex及DFAE-52进行了纯化,再免疫新西兰白兔制备兔抗鳖抗体的抗血清,纯化后以辣根过氧化物酶（HRP）标记酶标复合物,方阵滴定法确定酶标复合物的最适稀释度为1/3200。用温和气单胞菌TL970424株制成铝胶佐剂灭活苗免疫健康中华鳖,经一次免疫和二次免疫后,分别在不同时间采集血清,用ELISA法测定血清抗体变化规律。结果表明中华鳖对该菌苗产生良好的体液免疫应答。免疫后20d抗体水平达到高峰。在测定期间内二次免疫组的抗体水平高于一次免疫组。表明中华鳖存在着二次免疫应答,但与哺乳类相比,中华鳖的二次应答则相对软弱。免疫后90d对一次免疫组的鳖进行了攻毒试验,10d后免疫鳖100%存活,而非免疫对照组鳖则100%死亡,表明温和气单胞菌TL970424株灭活苗免疫效果良好。     

小鼠S_(180)瘤细胞免疫性的初步研究

本文选用灵敏度高,特异性强的酶标免疫吸附测定法(ELISA)及A.D.C.C.测试法(Antibody Dependent Cell mediated Cytotoxicity Assay)检测到以S_(180)瘤细胞免疫的小鼠血清中有抗S_(180)瘤细胞的特异抗体。并初步探讨了S_(180)肿瘤细胞膜上的唾液酸与抗原抗体相互作用的关系。实验表明S_(180)肿瘤细胞经唾液酸酶作用,水解去除瘤细胞表面的唾液酸后,对其与特异抗体的结合反应无明显影响。这提示S_(180)瘤细胞膜表面的糖蛋白上的唾液酸未必直接参与抗原抗体的特异性结合。以上结果为进一步研究患瘤小鼠各阶段的免疫情况及寻求最佳免疫时机,为治疗肿瘤奠定了基础。     

免疫聚合酶链反应技术的建立及其对甲胎蛋白的检测

免疫ＰＣＲ是一种新的具高敏感性的抗原检测技术,它类似传统的ＥＬＩＳＡ法,若与抗体连接的酶用ＤＮＡ片段代替,则该ＤＮＡ片段可用于ＰＣＲ扩增。以链酶亲合素搭桥将生物素标记的抗体与ＤＮＡ相连建立了免疫ＰＣＲ技术,并将其用于检测甲胎蛋白（ＡＦＰ）,其敏感性比ＥＬＩＳＡ法高１０４。因此,免疫ＰＣＲ有可能作为一种具高敏感性的检测手段用于临床早期诊断     

蛋白质微阵列检测抗原-抗体相互作用

为了制备蛋白质微阵列和研究芯片表面抗原-抗体的相互作用,研究了如何在玻片表面固化蛋白质和用荧光染料（Cy3,Cy5）对蛋白质进行标记.结果表明,在醛基修饰的玻璃表面,通过共价偶联的方法将抗原或抗体固定到芯片表面,能使二者保持其特异性结合能力.同时,荧光标记后的抗原或抗体仍然具有特异性结合能力.蛋白质微阵列是通过机械手在玻片表面排阵制作的.芯片上的荧光信号获取采用了激光共焦荧光扫描系统.用不同浓度的抗原探针阵列,对其相应的抗体靶分子的特异性结合进行了分析和研究.此外,还通过在玻片表面固定兔IgG和固定鼠IgG,对羊抗兔和羊抗鼠抗体与其相应抗原的特异性相互作用进行了检测.     

一种酶免疫传感器的制备和性能测试

这种酶免疫传感器是采用丝素蛋白溶液将待测抗原(兔IgG)固定在基础电极表面,选用抗体(山羊抗兔IgG-HRP)与其识别结合。利用H2O2将抗原抗体结合的电位响应信号放大而检测抗原的浓度。该传感器测定抗原的最低检测浓度1.0×10-10 mol/L,线性范围1.0×10-8~1.0×10-10 mol/L,响应时间为10s。通过电泳的方法加速抗原抗体的识别结合,反应时间由原来的90min缩短到30min,这在国内外鲜有报道。这种以固定化抗原结合酶标抗体量的多少作为检测抗原标准的新型酶免疫传感器,在临床检测、生物医学研究等领域将会有广阔的应用前景。     

Detection of O-acetylated Vi polysaccharide of Salmonella enterica subspecies typhi by enzyme immunoassay.

Immunisation with capsular Vi polysaccharide (Vi PS) of Salmonella enterica serovar Typhi (S. typhi) protects against typhoid. This protection depends on the presence of O-acetyl groups on the Vi PS, which form an immunodominant epitope. An antiserum raised against conjugated Vi PS was used as the basis for an indirect Enzyme Immunoassay (EIA). The antiserum did not react with lipopolysaccharide of five gram negative bacteria including S. typhi. Vi PS from three different sources was tested, and all but one of 18 native Vi PS preparations had EIA values comparable to a standard Vi PS preparation. The sensitivity of the EIA for the detection of O-acetyl groups on Vi PS was compared to an NMR spectroscopy assay (Biologicals 28 (2000) 17-24). The EIA distinguished between O-acetylated and de-O-acetylated Vi PS preparations. However, significantly lower EIA reactivity was observed only for samples which had O-acetylation levels of 25% or less. This assay should facilitate batch control of Vi vaccines.     

The immunological status indices of monkeys inoculated with a meningococcal B vaccine

The method for the determination of bacterial antibodies to group B meningococci was worked out. The method was used for the determination of antibodies to group B meningococcal vaccine produced in the USSR. The dynamic study of antibodies to protein, polysaccharide and lipopolysaccharide antigens of group B meningococci was made by the method of the enzyme immunoassay (EIA), and the safety of the vaccine was studied by the determination of autoantibodies active against brain tissue antigens. The data thus obtained were indicative of the immunological activity of group B protein-polysaccharide vaccines, manifested by the capacity for stimulating bactericidal antibodies whose level increased 8- to 10-fold after the immunization of monkeys in 2 and 3 injections. Similarity in the dynamics of the formation of bacteriolysins and antibodies to protein antigen, as determined in EIA, was noted. The vaccine was found to stimulate no cytotoxic anticerebral antibodies in the glia migration test, which was indicative of the safety of group B meningococcal vaccine.     

Autoantibody biomarker opens a new gateway for cancer diagnosis

The list of cancer markers of current interest has grown considerably, but none of the markers used in clinical work is a true tumor marker. These cancer biomarkers are based on the determination of tumor antigens. Here, we report a single method of autoantibody enzyme immunoassay (EIA) screens for a spectrum of serum tumor markers. A comparison of the autoantibody-based EIA to conventional antigen EIA kits, using receiver operating characteristic (ROC) plots, showed that the autoantibody EIA can significantly enhance the sensitivity and specificity of tumor markers. The detection of serum autoantibodies for a spectrum of serum tumor markers, as demonstrated here, suggests that most, if not all, serum cancer biomarkers produce autoantibodies. A unique autoantibody biomarker screening method, as presented here, might therefore facilitate achieving the accurate and early diagnosis of cancer.     

The characteristics of detecting the tick-borne encephalitis virus antigen in the ELISA and indirect hemagglutination reaction by means of scanning electron microscopy

The surface of polystyrene plates was studied at different stages of the enzyme immunoassay (EIA) and the passive hemagglutination (PHA) test by the method of scanning electron microscopy in the detection of tick-borne encephalitis (TBE) virus antigen. The study revealed that in the process of EIA larger antigens were washed away from the plate surface. The objects detected on the polystyrene surface were identified as conglomerations of the virions of TBE virus, but whole virions were shown to play no decisive role in EIA. The conclusion was made that, due to some specific features of this method, EIA was more sensitive in reaction with small antigens (individual glycoproteids, their small complexes). And, respectively, the PHA test was more sensitive in reaction with large antigenic complexes (whole virions, their conglomerations, immune complexes).     

Tumour-specific Antibodies in Human Malignant Melanoma and their Relationship to the Extent of the Disease

Biopsy specimens and sera were obtained from 103 melanoma patients. Autoantibodies were demonstrated by (1) complement-dependent cytotoxicity of autologous melanoma cells in short-term culture; (2) complement-dependent inhibition of ribonucleic acid synthesis; (3) immunofluorescent staining of the cytoplasm of killed melanoma cells and of the surface membrane of viable melanoma cells. Over one-third of the sera studied had antibodies to autologous melanoma cells. Although for technical reasons all three tests could not be performed with the cells from every melanoma, whenever multiple testing was possible there was complete concordance. The autoantibodies were virtually confined to patients in whom the disease was not widely disseminated, and over 80% of such patients had positive sera. In a limited number of patients who have been followed autoantibodies disappeared as the disease progressed to become widely disseminated. Two patients with generalized disease developed autoantibodies following inoculation by their own irradiated tumour cells.Two types of autoantibodies were recognized: one, active against antigen(s) in the cell surface membrane, was specific for each tumour—that is, only the autologous serum reacted—and was concerned in the cytotoxic activity; the other reacted with cytoplasmic antigens which appeared to be present in most or all melanoma cells.     

Immunofluorescence and electron microscopy of the cytoplasmic surface of the human erythrocyte membrane and its interaction with Sendai virus

A method was developed for directly observing the inner surfaces of plasma membranes by light and electron microscopy. Human erythrocytes were attached to cover slips (glass or mica) treated with aminopropylsilane and glutaraldehyde, and then disrupted by direct application of a jet of buffer, which removed the distal portion of the cells, thus exposing the cytoplasmic surface (PS) of the flattened membranes. Antispectrin antibodies and Sendai virus particles were employed as sensitive markers for, respectively, the PS and the external surface (ES) of the membrane; their localization by immunofluorescence or electron microscopy demonstrated that the major asymmetrical features of the plasma membrane were preserved. The fusion of Sendai virus particles with cells was investigated using double- labeling immunofluorescence techniques. Virus adsorbed to the ES of cells at 4 degrees C was not accessible to fluorescein-labeled antibodies applied from the PS side. After incubation at 37 degrees C, viral antigens could be detected at the PS. These antigens, however, remained localized and did not diffuse from the site of attachment, as is usually seen in viral antigens accessible on the ES. They may therefore represent internal viral antigens not incorporated into the plasma membrane as a result of virus-cell fusion.     

Detecting ultraviolet damage in single DNA molecules by atomic force microscopy

We report detection and quantification of ultraviolet (UV) damage in DNA at a single molecule level by atomic force microscopy (AFM). By combining the supercoiled plasmid relaxation assay with AFM imaging, we find that high doses of medium wave ultraviolet (UVB) and short wave ultraviolet (UVC) light not only produce cyclobutane pyrimidine dimers (CPDs) as reported but also cause significant DNA degradation. Specifically, 12.5 kJ/m(2) of UVC and 165 kJ/m(2) of UVB directly relax 95% and 78% of pUC18 supercoiled plasmids, respectively. We also use a novel combination of the supercoiled plasmid assay with T4 Endonuclease V treatment of irradiated plasmids and AFM imaging of their relaxation to detect damage caused by low UVB doses, which on average produced approximately 0.5 CPD per single plasmid. We find that at very low UVB doses, the relationship between the number of CPDs and UVB dose is almost linear, with 4.4 CPDs produced per Mbp per J/m(2) of UVB radiation. We verified these AFM results by agarose gel electrophoresis separation of UV-irradiated and T4 Endonuclease V treated plasmids. Our AFM and gel electrophoresis results are consistent with the previous result obtained using other traditional DNA damage detection methods. We also show that damage detection assay sensitivity increases with plasmid size. In addition, we used photolyase to mark the sites of UV lesions in supercoiled plasmids for detection and quantification by AFM, and these results were found to be consistent with the results obtained by the plasmid relaxation assay. Our results suggest that AFM can supplement traditional methods for high resolution measurements of UV damage to DNA.     

Preparation of insolubilized-DNA film with three-dimensional network and removal of endocrine disruptors.

A water-insolubilized film was prepared by UV irradiation on a dried DNA film. When a UV-irradiated DNA was examined using a circular dichroism spectroscopy, a double stranded structure was observed as well as that of native DNA. The UV irradiated DNA film was also accumulated intercalating reagents. These results suggested that the double stranded structure was involved in the UV irradiated DNA film with a three-dimensional network. The thymine-thymine dimer formation was suggested to be involved in the cross-linking reactions by the polymerization analysis using poly(dA)-poly(dT) and poly(dG)-poly(dC). We also demonstrate the utilization of the UV-irradiated DNA film as a functional material for the accumulation of harmful DNA intercalating pollutants in aqueous solution. These results suggested that the UV-irradiated DNA film was applicable as a functional material for medical, engineering and environmental sciences.     

Establishment of a monoclonal antibody recognizing ultraviolet light-induced (6-4) photoproducts

We obtained a monoclonal antibody directed against UV-induced DNA damage. Analysis of the antigenic determinant in UV-irradiated DNA recognized by this antibody, 64M-1, revealed that it bound UV-irradiated oligo- or poly-nucleotides containing thymine-thymine or thymine-cytosine sequences. The antibody failed to bind DNA irradiated with 313 nm UV in the presence of acetophenone, which contained predominantly thymine dimers as DNA damage. The binding activity of this antibody to 254-nm UV-irradiated DNA decreased with 313-nm UV irradiation, and the decrease of this binding activity correlated with the decrease of fluorescence corresponding to (6-4) photoproducts. These results suggest that the antigenic determinant recognized by this monoclonal antibody is a (6-4) photoproduct. Using autoradiography with 3H-antibody, we could detect the formation of the (6-4) photoproduct in individual human cells irradiated with 254-nm UV doses as low as 20 J/m2.     

Surface characteristics of UV-irradiated chitin-based polyurethane elastomers

Chitin-based polyurethane elastomers (PUEs) constituted on 4,4′-diphenylmethane diisocyanate (MDI), poly(ε-caprolactone) (PCL) and extended with blends of chitin/1,4-butane diol were first synthesized via two step polymerization technique and then irradiated for 50, 100 and 200 h in an UV exposure chamber as such the spectral distribution of the light is good match for terrestrial solar radiation. The surface properties of the irradiated PU samples were investigated by contact angle measurements, surface free energy and water absorption (%), total work of water adhesion to polymer and equilibrium degree of swelling. The effects of UV-irradiation time and chitin contents in chain extenders (CE) proportion on surface properties were investigated. Results of the aforementioned surface techniques revealed that the UV-irradiated polyurethane samples were affected by varying the UV exposure period.