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J P Rotmans

Publications and source records attributed to J P Rotmans.

At least 37 records · Page 2Linked to original sources
PubMed1982

KCl-Extractable surface antigens of Schistosoma mansoni: immunological characterization and applicability in immunodiagnosis.

A Schistosoma mansoni antigen preparation was obtained by extraction of adult worms with a 3 M KCl solution. An indirect immunofluorescence reaction on cryostat sections of adult worms showed that the extracted antigens mainly originated from the tegument. The complex antigenic composition of the tegument extract was shown by immunoelectrophoresis against serum from infected mice and immunized rabbits, which gave up to 9 and 17 precipitation lines, respectively. When we compared the use of adult worm antigens and the tegument antigen preparation in the DASS and ELISA tests for immunodiagnosis of human schistosomiasis, the average sensitivity of the tests with the two preparations was about equal, although considerable differences between individual sera occurred. Analysis of tegument antigens, fractionated by gel filtration, showed that the main serological activity of the tegument antigen preparation was due to high molecular weight antigens.

Animals↗
PubMed1980

Automated measurement of immunogalactosidase reactions with a fluorogenic substrate by the aperture defined microvolume measurement method and its potential application to Schistosoma mansoni immunodiagnosis.

For automated read-out of immunogalactosidase assays with a fluorogenic substrate, performed in microtitration trays, an inverted fluorescence microscope equipped with a photometer and a scanning stage and operated by a microprocessor has been used. Trays (60 and 96 wells) were scanned in 1 min and corrected measurements and a histogram of the results printed out in a few minutes. A lower level of 4 ng of the reaction product, 4-methylumbelliferone, was detected. By making the measuring system flexible we were also able to use it for fluorescence measurements of individual agarose beads or cells and for extinction measurements in ELISA reactions with a chromogenic substrate. On comparing FITC and galactosidase conjugates in a DASS-test, and peroxidase and galactosidase conjugates in an ELISA, with Schistosoma mansoni infection as test system, it appeared that the galactosidase modification of both assays was 30-50 times more sensitive than the FITC or peroxidase modification. For S. mansoni egg antigen, a lower detectable level of 0.1 ng antigen/ml was achieved.

Antigens↗
PubMed1980

Separation and comparative immunoassay (DASS, ELISA) with antigens from adult Schistosoma mansoni.

Antigenic fractions were prepared from adult Schistosoma mansoni by homogenization and solubilization in phosphate buffer, and subsequent separation on Ultrogel AcA-44. The fractions were tested for antigenicity in two immunodiagnostic techniques, the defined antigen substrate spheres (DASS) system, and the enzyme-linked immunosorbent assay (ELISA), using serum from schistosomiasis patients. The results obtained in the two tests correspond to each other. Sera from 25 patients with proven schistosomiasis were tested with ELISA, using the antigen fractions. For all sera tested, the titres obtained, were dependent on the antigen fraction used. However, areas of high antigenicity were different for different sera. Antigens with molecular weight lower than 60,000, gave negative results for about 30% of the sera but those with molecular weight higher than 60,000 gave positive results for all sera. For about 60% of the sera, the sensitivity of ELISA increased when antigens of increasing molecular weight were used. Cross reactions with two other helminth infections occurred mainly with high molecular weight antigens.

Animals↗
PubMed1980

Applicability of different antigen preparations in the enzyme-linked immunosorbent assay for schistosomiasis mansoni.

The applicability of seven different antigen preparations for the detection of antibodies against Schistosoma mansoni was tested in the enzyme-linked immunosorbent assay. For this purpose, sera from children and adults from Surinam infected with S. mansoni were screened for the presence of specific antibodies against the various antigens. With all antigens, generally better results were obtained with the sera from children than with those from adults. The best results were obtained when the trichloroacetic acid-soluble fraction of adult worm antigen (containing the proteoglycan circulating anodic antigen) was used.

Animals↗
PubMed1975

Biochemical aspects of the visual process. XXVII. Stereospecificity of ocular retinol dehydrogenases and the visual cycle.

A comparative study is made of the stereospecificity of two particulate retinol dehydrogenases from bovine eyes and of horse liver alcohol dehydrogenase. The particulate retinol dehydrogenase of outer segments reacts with the all-trans isomers of retinaldehyde and retinol but not with the 11-cis compounds. In contrast, a particulate retinol dehydrogenase present in pigment epithelium reacts preferentially with the 11-cis compounds. Horse liver alcohol dehydrogenase (EC 1.1.1.1.) can convert both isomers, but the all-trans isomers are clearly preferred. Differences with regard to cofactor preference and stability are also noted. The outer segment enzyme clearly functions in the rhodopsin cycle. It is unlikely that the 11-cis retinol dehydrogenase from pigment epithelium is directly involved in providing 11-cis retinaldehyde from rhodopsin regeneration, but it may serve to make available 11-cis retinaldehyde from rhodopdsin, digested in phagocytized rod sacs, for the synthesis of visual pigment by the visual cells.

Alcohol Oxidoreductases↗