Search PubMed⌕ Search

Biomedical subjects

A M Deelder

Publications and source records attributed to A M Deelder.

At least 163 records · Page 9Linked to original sources
PubMed1981

A comparative study on the preparation of immunoglobulin-galactosidase conjugates.

For the application of beta-D-galactosidase-immunoglobulin conjugates in the enzyme-linked immunosorbent assay (ELISA), four techniques for the preparation of such conjugates were compared. Sheep immunoglobulin (Ig) (against soluble egg antigens of the trematode Schistosoma mansoni) was coupled to beta-D-galactosidase by means of 1) glutaraldehyde treatment, 2) the heterobifunctional reagent N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP), and 3,4) two different procedures using the coupling agent m-maleimidobenzoyl-N-hydroxysuccinimide ester(MBS). The prepared conjugates were then fractionated by gel filtration on Sepharose 6B and the resultant molecular weight fractions were tested in an ELISA for the detection of S. mansoni antigen. Optimal results were obtained with a conjugate that was synthesized according to one of the two techniques using MBS. With this conjugate, 10(-9) g antigen/ml could still be detected in an ELISA with a chromogenic substrate, which was at least ten times as sensitive as with the other conjugates. Application of a fluorogenic substrate resulted in a lower detection level of 10(-10) g antigen/ml.

Animals↗
PubMed1981

Renal disease in chronic experimental Trypanosoma gambiense infections.

Two recently isolated stocks of Trypanosoma brucei gambiense of human origin gave rise to a moderate to severe proliferative or membranoproliferative glomerulonephritis in 40 or 44 NMRI and C57BL/6J mice infected for 7-22 weeks. Extensive granular deposits of C3, IgG1 and IgG3 were found in the mesangium, together with smaller quantities of IgG2a, IgG2b, and IgM. No trypanosomal antigen could be detected in the deposits though specific anti-trypanosoma antibodies were found in kidney eluates. By electron microscopy, a conspicuous proliferation of mesangial and endothelial cells was observed and electron-dense deposits were seen in a mesangial and subepithelial localization. With one of these trypanosome stocks, four of seven Wistar rats infected for 9-15 weeks developed morphologically similar glomerular lesions. Four other trypanosome stocks did not evoke renal alterations in 17 other rats infected for 13-56 weeks. Experimental infection in mice or rats appears to be a suitable model for the study of renal disease in chronic African sleeping sickness.

Animals↗
PubMed1981

Immunodiagnosis of recently acquired Schistosoma mansoni infection. A comparison of various immunological techniques.

A group of Dutch tourists, who became infected with Schistosoma mansoni in Ethiopia, was investigated in a serological follow-up study, during 8-50 weeks after infection. The following immunodiagnostic tests were applied: (1) the immunofluorescent antibody (IFA) test, both on frozen sections of adult worms, and in a modification for the detection of antibodies against gut-associated polysaccharide antigens; (2) the enzyme-linked immunosorbent assay (ELISA) with as antigens: adult worm antigens (AWA), cercarial antigens (CA), soluble egg antigens (SEA), and the purified antigens CAA and MSA1; (3) the defined antigen substrate spheres system with AWA as antigen in an immunofluorescence and immunoperoxidase modification; (4) the indirect haemagglutination reaction with AWA; and (5) the immunoelectrophoresis with AWA and antigens of the intermediate host. With these techniques it could be shown that in all persons which had been in contact with S. mansoni infected water, also in those not excreting schistosome eggs or not showing clinical symptoms of infection, specific anti-schistosome antibodies were present. No false-negative reactions were found with the ELISA with cercarial antigens, MSA1, or AWA-TCA, with the IFA detecting gut-associated polysaccharide antigens and with the immunoelectrophoresis. The highest titres were observed with the two techniques (IFA and ELISA) detecting antibodies against the gut-associated polysaccharide antigen CAA.

Enzyme-Linked Immunosorbent Assay↗
PubMed1980

The implantation of sepharose beads in mouse livers as an aid in the study of hepatic schistosomal fibrosis.

An experimental model of schistosomal portal fibrosis is described. Sepharose beads the size of schistosome eggs, loaded or not with soluble egg antigen (SEA) from Schistosoma mansoni, are injected into the coecal vein of C3H/Sn mice and become embolized in the liver. Only SEA-coated beads evoke a granulomatous reaction; this is enhanced by simultaneous priming of the mice with spleen cells from Schistosoma mansoni-infected syngeneic animals. The fibrosis, which ensues around the beads, is stable and is much more evident after priming. Preliminary collagen tissue immunotyping reveals the presence of collagen deposits of types I and III collagen. Type IV collagen remains unchanged in the portal tracts. The model appears to be well suited for studies of the pathogenesis of portal fibrosis.

Animals↗
PubMed1980

A comparison of the IFA and the ELISA for the demonstration of antibodies against schistosome gut-associated polysaccharide antigens in schistosomiasis.

The applicability of two immunodiagnostic techniques was studied for the detection of antibodies against schistosome gut-associated polysaccharide antigens in human schistosomiasis mansoni: the immunofluorescent antibody reaction (IFA) using Rossman's fixed paraffin sections of adult worms and the enzyme-linked immunosorbent assay (ELISA) with a trichloroacetic acid soluble fraction of total adult worm antigens (AWA-TCA). With the IFA, gut-associated polysaccharide antigens could be demonstrated with an anti-IgM conjugate in a high percentage of the sera tested, although false-negative reactions were occasionally recorded. The use of an anti-IgG conjugate resulted in the demonstration of antibodies against additional antigens in the parenchyma of the worm and on the tegument. Specific IgM antibodies were present in higher concentrations in the sera from children than in those from adults. Using AWA-TCA as the antigen preparation in the ELISA, only antibodies against the circulating anodic antigen (CAA) could be demonstrated. Pretreatment of the ELISA-plates with poly-L-lysine to couple AWA-TCA was not necessary. The ELISA was successfully applied with anti-Ig, anti IgG, and anti-IgM conjugates. With anti-Ig conjugate the test was very sensitive and gave less false-negative reactions than the IFA. There was a significant difference between Ig, IgG, and IgM titres of children and adults. The use of an immunogalactosidase assay with a fluorogenic substrate in the ELISA, resulted in a test which was able to detect antibodies at ten times higher dilutions than with the immunoperoxidase assay.

Adolescent↗
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

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↗
PubMed1979

H-2 linked immune response to murine experimental Schistosoma mansoni infections.

Mice of two congenic inbred strains C3H/Sn (H-2k) and C3H.B10 (H-2b) were infected with 100 Schistosoma mansoni cercariae. After the infection, the following parameters for the immunological response were studied: worm burden, mortality, antibody titre, spleen index, eosinophilia, delayed type of hypersensitivity and in vitro response to three S. mansoni antigen preparations. No difference in the worm burden and in the in vitro response to the antigen preparations of adult worm antigen, soluble egg antigens and the egg antigen MSA1, was found. The C3H.B10 mice showed a significantly higher mortality, antibody titre and delayed type of hypersensitivity while the C3H/Sn mice showed asignificantly higher spleen index and eosinophilia. This indicates that the H-2 region influences the course of an acute S. mansoni infection, whereas the susceptibility to the infection seems not to be influenced, as is shown by the worm burden.

Animals↗
PubMed1978

An indirect haemagglutination reaction for the demonstration of Schistosoma mansoni circulating anodic antigen.

Using the IgG fraction of a monospecific sheep antiserum against the circulating anodic antigen (CAA) of Schistosoma mansoni, an indirect haemagglutination reaction for the determination of this antigen was developed. This is the first time that an IHA has been applied to the detection of circulating antigens in parasite infections. The IHA proved to be highly sensitive; CAA levels up to 20 ng/ml could be measured. At the moment it appears to be the most sensitive technique for the determination of CAA levels. CAA could readily be detected in the sera of S. mansoni infected hamsters and in the immune complexes isolated from these sera, but never in sera from human schistosome infections.

Animals↗