Quantitative determination of circulating soluble egg antigen in urine and serum of Schistosoma mansoni-infected individuals using a combined two-site enzyme-linked immunosorbent assay.

Two enzyme-linked immunosorbent assays (ELISA-5B1 using monoclonal antibody [MAb] 114-5B1-A [IgG1] and ELISA-4D12 using MAb 114-4D12-A [IgG3]) that detect circulating soluble egg antigen (CSEA) of Schistosoma mansoni were combined into one assay. This assay showed better performance than either of the two MAbs alone in detecting egg antigen, which was demonstrated with 80 urine samples from patients infected with Schistosoma mansoni from Zaire. The lower detection limit of the combined ELISA was 90 pg of the trichloroacetic acid-soluble fraction of soluble egg antigen (SEA-TCA) per milliliter. Thirty-two serum samples and 107 urine samples from uninfected Dutch individuals were negative when tested with the combined ELISA. This assay showed the same sensitivity (86.3%) with patients' urine samples as parallel testing with ELISA-5B1 and ELISA-4D12 (85%), while ELISA-5B1 and ELISA-4D12 showed sensitivities of 81.3% and 75%, respectively. The sensitivity of the combined ELISA with 51 serum samples was 84.3%, and three of five serum samples available from the seven patients with negative urine were positive for CSEA. The concentration of CSEA calculated from a four-parameters logistic curve for samples tested showed a correlation with egg output and serum circulating anodic antigen (P < 0.0001). Circulating soluble egg antigen in urine showed a significant decrease with an increase in age of the patients in relation to serum CSEA and egg output.

A poliovirus type-specific IgM antibody-capture enzyme-linked immunosorbent assay for the rapid diagnosis of poliomyelitis.

OBJECTIVES: To develop and evaluate an IgM antibody-capture ELISA for the rapid detection of poliovirus type-specific IgM antibodies in serum and CSF of patients suspected of poliomyelitis. STUDY DESIGN: The assay uses monoclonal antibody to human IgM as catching antibody, monovalent IPV as antigen and type-specific monoclonal antibodies labeled with horseradish peroxidase as detecting antibody. RESULTS: Sera from 21 of 24 patients, contacts of these patients or recently vaccinated children were positive in the IgM assay. Sera from 100 healthy individuals were negative in all three poliovirus type-specific ELISAs. Sera from 5 of 81 patients with non-polio viral infections showed (weak) reactivity in one or more of the IgM assays. In a prospective study, sera and/or CSFs from 72 patients with a recent clinical diagnosis of poliomyelitis were tested. A homotypic IgM antibody response was found in 51 of the 55 patients which shedded wild poliovirus in stool or throat. Poliovirus type-specific IgM antibodies were also detected in serum from 13 of the 17 patients, from whom no poliovirus was isolated. Poliovirus type-specific IgM-antibodies could be detected from the second day up till at least 28 days after onset of paralysis. BACKGROUND: Poliovirus infections still create measurable morbidity and mortality in the world. Rapid diagnosis methods are needed to detect infection. CONCLUSION: The use of the poliovirus type-specific IgM antibody-capture ELISA allows rapid diagnosis of poliomyelitis within 24 h after obtaining serum or a CSF specimen.

The postpolio syndrome: no evidence for poliovirus persistence.

To investigate the possibility of poliovirus persistence in patients with the postpolio syndrome, we examined skeletal muscle biopsy specimens, cerebrospinal fluid specimens, and sera for the presence of poliovirus RNA by the polymerase chain reaction, and for IgM antibodies by a poliovirus type-specific IgM antibody-capture enzyme-linked immunosorbent assay. In none of these specimens was poliovirus RNA or a poliovirus type-specific IgM response detected. These results argue against the hypothesis that poliovirus persists in patients with the postpolio syndrome and plays a role in the pathogenesis of the postpolio syndrome.

Phenethyl alcohol disorders phospholipid acyl chains and promotes translocation of the mitochondrial precursor protein apocytochrome c across a lipid bilayer.

The interaction of phenethyl alcohol with model membranes and its effect on translocation of the chemically prepared mitochondrial precursor protein apocytochrome c across a lipid bilayer was studied. Phenethyl alcohol efficiently penetrates into monolayers and causes acyl chain disordering judged from deuterium nuclear magnetic resonance measurements with specific acyl chain-deuterated phospholipids. Translocation of apocytochrome c across a phospholipid bilayer was stimulated on addition of phenethyl alcohol indicating that the efficiency of translocation of this precursor protein is enhanced due to a disorder of the acyl chain region of the bilayer.