生物素─链霉亲和素系统在检测巨细胞病毒抗体中的应用

本文用自制ＣＭＶ抗原和生物素－链霉亲和素系统试剂，通过最适条件的对比，建立了检测人血清中抗巨细胞病毒ＩｇＭ、ＩｇＡ类抗体的ＢＳＡ－ＥＬＩＳＡ，并与普通ＥＬＩＳＡ作比较，结果表明，ＢＳＡ－ＥＬＩＳＡ的非特异性吸附明显低于普通ＥＬＩＳＡ，与普通ＥＬＩＳＡ相比，抗体效价分别提高５和７倍，阳性率分别提高６８％和１５３．５％。在实际工作中曾用ＢＳＡ－ＥＬＩＳＡ检测临床样品１６５份，就所得结果进行分析。表明ＢＳＡ－ＥＬＩＳＡ检测ＣＭＶＩｇＭ和ＩｇＡ可提高特异性和灵敏度，值得推广应用。     

Role of oxidative stress,angiogenesis and chemo-attractant cytokines in the pathogenesis of ischaemic protection induced by remote ischaemic conditioning: Study of a human model of ischaemia-reperfusion induced vascular injury

Aims

We explored the effect of remote ischaemic conditioning (RIC) on endothelial function and on circulating mediators.

应用单克隆抗体测定纤维连结蛋白ELISA方法的建立

本文介绍用McAb作为包被和检测抗体进行双抗体夹心ELISA来测定人血浆纤维连结蛋白。通过实验找出最佳条件,即两种McAb混合使用,在McAb和酶结合物稀释液内加入4％PEG及使用TMBI底物的最适浓度等,该法敏感性可达80ng/ml,可作为临床常规方法使用。     

Adsorption of anti-dsDNA antibodies by immobilized polyanionic compounds.

Antibodies to dsDNA are characteristically present in serum from patients with systemic lupus erythematosus (SLE), and have been shown to have the capacity to react with various molecules bearing repeating negative charges. After a number of polymeric or monomeric molecules with differently charged groups and hydrophobic molecules had been coupled covalently as ligands on cellulose gel, the adsorption capacities of the ligands for anti-dsDNA antibodies were evaluated. It was found that gels coupled with polyanionic dextran sulphate (DXS) and polyacrylic acid (PA) and monoanionic sulphanilic acid (SA) absorbed anti-dsDNA antibodies effectively. DXS gel also adsorbed antibodies to ssDNA and heparan sulphate, antigens with repeating negatively charged moieties, while no ligand was able to adsorb anti-nRNP antibodies. The finding that DXS gels adsorbed anti-dsDNA antibody in proportion to their charge density, and that the interaction between anti-dsDNA and DXS gel is broken readily by an increase in ionic strength, indicated that the binding is ionic in nature. Moreover, virtually all F(ab')2 anti-dsDNA became adsorbed onto the DXS gels, suggesting that the binding occurred via specific antigen-binding sites on the antibody molecule. Binding of these polyanion-binding autoantibodies with anionic sites in the glomerular basement membrane may therefore cause the tissue damage observed in SLE.     

Horizontal transmission of hepatitis B virus infection in household contacts, Pune, India

The study was undertaken to detect the risk of infection, if any, among 193 household contacts of 40 hospitalised hepatitis patients (group I) with hepatitis B surface antigen (HBsAg) in their blood. As a control group, 103 household contacts of 27 hospitalised hepatitis patients who were negative for HBsAg (group II) were investigated. The family contacts of the former group had a significantly higher prevalence of HBV infection than those of the latter group (P less than .001). Significant differences were observed both in the prevalence of HBsAg (P less than .05) and antibody to HBsAg (anti-HBs) (P less than .025) between the two groups. IgM antibody to hepatitis B core antigen (anti-Hbc-IgM) was detected in 32 out of the 39 (82%) sera tested from the patients of group I with HBsAg. A statistically significant difference (P less than .005) of HBV prevalence was also found in the contacts of these 32 patients suffering from acute hepatitis B as compared to the contacts of the patients of group II. Overall, the children of the first group showed a significantly higher prevalence of HBsAg as compared to the second group. All the children with HBsAg were positive for HBeAg also, but were negative for anti-HBc-IgM. Anti-HBs was detected in a significantly larger number of adult females. Spouses were found to be affected more than other relatives. A significant difference (P less than .025) was noted in the number of families having HBV markers in group I (80.0%) as compared to those in group II (48.1%).(ABSTRACT TRUNCATED AT 250 WORDS)     

The significance of blood levels of IgM,IgA, IgG and IgG subclasses in Sudanese visceral leishmaniasis patients

We developed an ELISA test using leishmania antigenic extracts to detect antigen-specific antibody responses, including subclass and isotype analysis, in visceral leishmaniasis (VL) patients from the Sudan. A total of 92 parasitologically proven patients were compared with cutaneous leishmaniasis, schistosomiasis, malaria, onchocerciasis and tuberculosis patients, as well as with healthy endemic and non-endemic controls. Some VL patients were examined before and after chemotherapy. VL patients showed significantly higher IgG responses compared with all other groups (93·4% sensitivity, 93·7% specificity), and higher (but not significantly) IgM responses. All groups showed low IgA levels. All groups showed low IgA levels. All IgG subclasses, IgG1, 2, 3, and 4, showed higher levels in patients than all other groups, with IgG1 and IgG3 levels being significantly reduced following treatment. The rank order for specificity and sensitivity for IgG subclasses was IgG3 > IgG I> IgG2> IgG4.     

Hepatitis C virus seroconversion rate in established blood donors

The results of hepatitis C virus (HCV) antibody test of 237, 813 blood donations collected from 143, 815 donors by the West Midlands Blood Transfusion Centre in 1993 were analyzed retrospectively in order to determine the seroconversion rate among established previously anti-HCV negative donors. Three hundred sixteen (0.22%; 1 in 455) donors were positive by the enzyme linked immunosorbent assay (ELISA) screening test and 34 (0.024%; 1 in 4, 230) donors were positive by ELISA and the Recombinant Immuno Blot Assay (RIBA). Three donors previously negative for HCV antibody reacted positively by both tests. The annual seroconversion rate was calculated as one in 35, 937 donors. This figure argues against limitation of HCV antibody screening to new blood donors. A further 45 donors negative on previous screening reacted positively by ELISA and were indeterminate by RIBA. Unexpectedly, lapsed blood donors first tested for HCV antibody in 1993 had high positive reaction rates by ELSA and RIBA, which was significantly (P < 0.001) higher than those of new donors. RIBA-positive reaction rate among ELISA-positive donors was significantly higher amongst males than females (P < 0.0011. © 1995 Wiley-Liss, Inc.     

Evaluation of Onchocerca volvulus-specific IgG4 subclass serology as an index of onchocerciasis transmission potential of three Gabonese villages

The major objective of this study was to evaluate the usefulness of IgG4 ELISA and Western blot analysis, using a crude extract of Onchocerca volvulus adult worms as antigens, for diagnosing onchocerciasis in a Gabonese paediatric population with mixed filarial infections. The subjects had loaisis, streptocercosis or mansonellosis in addition to onchocerciasis. Control sera from loaisis or mansonellosis subjects residing outside the endemic zone were used to provide the cut-off point for positive results. The IgG4 ELISA had a specificity of 96% but a lower sensitivity of 78·7%. It detected 25 onchocerciasis cases out of 65 individuals who were negative on parasitological examination. Furthermore, the ELISA provided a more accurate picture of onchocerciasis transmission in a village with very low skin microfilartal load. A 27·5-kD antigen was identified on Western blots as a marker of onchocerciasis. The paediatric population provided a reliable window for assessing the parasitologic and serologic parameters in the three villages with disparate levels of onchocerciasis transmission.     

Development of a quantitative monoclonal antibody‐based immunoassay for humicola ianuginosa on rice grains and comparison with conventional assays

A sensitive, specific, quantitative enzyme‐linked immunosorbent assay (ELISA) has been developed that can be used to determine the extent of mycelial growth of a sporulating thermophilic fungus, Humicola lanuginosa on the surface of rice grains. The assay employs a monoclonal antibody EC6, developed in a previous study, which does not recognize spores of the fungus. Using antigen‐coated wells, a direct linear relationship was established between dilutions of extracts from freeze‐dried mycelium (0.5 to 3 μg/ml) and absorbance values but to eliminate day‐to‐day variations it was found to be necessary to run a dilution series, prepared from stock freeze‐dried mycelium, with every test sample. The ELISA method was compared with conventional quantitative methods. Estimates of total mycelial length in freeze‐dried material by ELISA were found to be in the same order of magnitude as those determined by ergosterol and a theoretical calculation. The ELISA method also compared favourably with direct linear measurements (by photomicrography) of live mycelium present in aliquots from homogenates of a 1 cm² plug taken from a plate but estimates of the latter by the dilution plate count method were much lower. In assays with inoculated rice grains, the quantitative ELISA method proved more sensitive than either the ergosterol method or direct plating of surface‐sterilized grains. The ELISA method also has the advantage of being highly specific and quick to conduct.