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Biomedical subjects

A M Deelder

Publications and source records attributed to A M Deelder.

At least 127 records · Page 7Linked to original sources
PubMed1988

Schistosoma mansoni: impaired clearance of model immune complexes consisting of circulating anodic antigen and monoclonal IgG1 in infected mice.

The clearance of schistosome-specific model immune complexes (IC) consisting of circulating anodic antigen (CAA), a gut-associated excretory-secretory antigen, and radiolabeled monoclonal antibody (IgG1) was investigated in mice with a light and heavy Schistosoma mansoni infection and in noninfected control animals. The size analysis of the in vitro prepared and injected IC, as determined by density gradient centrifugation, revealed a wide peak at 11S. In infected animals the injected IC were cleared at a significantly lower rate than in control mice. This was attributed to a decreased uptake of IC by the liver in infected mice. In heavily infected mice, 30 min after injection of 11S IC, 8S, 11S, and greater than 11S IC were present in the serum, whereas only small 8S IC were detected in the serum of lightly infected animals and noninfected controls. Immune complexes were also present in the serum of heavily infected mice 30 min after injection of antibody and were detectable as 11S and greater than 11S IC. The importance of this study is twofold. First, these results show that schistosome-specific monoclonal antibodies can be used in the production of model immune complexes applicable in clearance studies. Second, our findings might be of importance when the possible pathogenicity of circulating IC in schistosomiasis is considered.

Animals↗
PubMed1988

Detection of circulating anodic antigen by ELISA for seroepidemiology of schistosomiasis mansoni.

Sera of individuals from Burundi excreting eggs of Schistosoma mansoni (prevalence 35%; 178 subjects) and of similar individuals from Maniema, Zaire (prevalence 95%; 99 subjects), and of 159 Dutch and 81 Zairean non-infected controls, were screened by enzyme-linked immunosorbent assay for the presence of schistosome circulating anodic antigen (CAA). No false positive results were obtained. The sensitivity of the test was 75% in Burundi and 93% in Zaire, a significant difference (P less than 0.05). However, in matched egg output classes the test results did not differ significantly; 60% and 67%, respectively, of those excreting 1-100 eggs per gram of faeces (epg), 86% and 100% of those excreting 101-400 epg, and 100% of those excreting over 400 epg were detected. The efficiency of the assay was 91% in Burundi and 93% in Zaire. The Spearman rank coefficient of correlation between antigen titre and egg output (determined by 3 consecutive Kato egg counts) was 0.61 in Burundi and 0.82 in Zaire. The sensitivity of the test compared well with a single egg count. In addition, preliminary data showed that occasionally CAA was detectable in serum of individuals not excreting schistosome eggs. As CAA is found only in the presence of living worms, such cases reflect active infections.

Animals↗
PubMed1988

Characterisation of kidney lesions in early schistosomal-specific nephropathy.

In this work 42 patients with active Schistosoma mansoni infection and renal involvement were examined. Of these, 16 had asymptomatic proteinuria (group I) and 26 had the nephrotic syndrome (group II). Fifteen nonschistosomal patients with idiopathic nephrotic syndrome were included as control cases (group III). Renal biopsy specimens were obtained from all patients and controls. These were examined by light microscopy (LM), by direct immunofluorescence microscopy using antisera against human IgG, IgM, IgA, C3, C4, C1q, and fibrinogen, and by indirect immunofluorescence microscopy using monoclonal antibodies directed against the circulating schistosome antigens, circulating anodic antigen (CCA) and circulating cathodic antigen (CCA). Schistosomal-specific deposits were seen in the renal glomeruli in 24 of the 42 schistosomal patients but in none of the 15 control patients. Although schistosomal-specific deposits were seen in seven of the 16 patients presenting with asymptomatic proteinuria, no morphological changes could be seen by LM. On the other hand, schistosomal-specific deposits could be seen in the kidneys of 17 of the 26 patients presenting with the nephrotic syndrome. All but one specimen showed morphological changes when examined by LM. These were consistent with mesangioproliferative glomerulonephritis in seven, focal segmental glomerulosclerosis in five, mesangiocapillary glomerulonephritis in two, membranous glomerulonephritis in one, and focal segmental hyalinosis in one patient. The present study clearly suggests that (a) schistosomal-specific nephropathy does exist in human settings, (b) it is an immune complex disease, and (c) CAA and CCA are major responsible antigens.

Adolescent↗
PubMed1988

Schistosoma mansoni: ultrastructural localization of the circulating anodic antigen and the circulating cathodic antigen in the mouse kidney glomerulus.

In this study two major antigens of Schistosoma mansoni, the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA), were localized ultrastructurally in glomeruli of S. mansoni infected mice. These antigens were studied by direct gold labeling in which anti-CAA and anti-CCA monoclonal antibodies were labeled with 5 and 15 nm gold particles, respectively. CAA and CCA were demonstrable in glomeruli at week 3 in the basement membrane and from 5 weeks in moderately electron-dense material of the mesangial matrix. Both antigens were also encountered in fenestrae of the endothelial cells, in filtration slit pores, and on the luminal membranes of the epithelial cells. It appears that CAA and CCA are arrested by the glomerular basement membrane and deposited in the mesangial matrix. CAA was seen in considerably smaller amounts than CCA. This was ascribed to the fact that CAA, but not CCA, is repelled by the negative charge of the capillary walls and the glomerular basement membrane.

Animals↗
PubMed1988

Effect of anti-schistosomal treatment on schistosomal-specific nephropathy.

Twenty-one patients with schistosomal-specific nephropathy (18 nephrotics and three with non-nephrotic proteinuria) were given anti-schistosomal treatment (oxamniquine and praziquantel). The schistosomal specificity of the kidney lesions was assessed by the detection of schistosomal-specific antigens (CAA and CCA) and antibodies deposited in the renal glomeruli of these patients. After anti-schistosomal treatment, the patients were followed for clinical and laboratory changes occurring within 12 months. In addition, 15 patients had a second kidney biopsy and the histopathological and the immunopathological findings were compared with those observed in the first biopsy. Based on clinical, laboratory and histopathological evaluations, none of the patients subjected to the study showed regression of the kidney lesion following antischistosomal treatment; in fact three patients showed progression in their lesions, one of them reaching end-stage renal failure. The histopathology of these three cases was focal segmental glomerulosclerosis. Our data suggest that anti-schistosomal treatment in an established disease state, will not produce remission.

Adult↗
PubMed1987

A simple and rapid treatment (trichloroacetic acid precipitation) of serum samples to prevent non-specific reactions in the immunoassay of a proteoglycan.

In our laboratory serum components interfering in the immunoassay of the schistosome proteoglycan circulating anodic antigen (CAA) in serum necessitated us to develop a simple technique by which the non-specific reaction of negative control sera could be prevented. Trichloroacetic acid was added to serum samples to precipitate interfering (glyco-)proteins. After centrifugation, the supernatant was neutralized and used directly either in the ELISA or in the indirect haemagglutination. This method gave satisfactory results, i.e., negative control sera did no longer give false positive reactions, while the titre of the positive controls remained unaffected. This method could also be successfully applied for the pretreatment of urine samples.

Antigens, Helminth↗
PubMed1987

Ultrastructural localization of the circulating anodic antigen and the circulating cathodic antigen in the liver of mice infected with Schistosoma mansoni: a sequential study.

The present study describes the ultrastructural localization of two important circulating schistosome antigens--the circulating anodic antigen (CAA) and the circulating cathodic antigen (CCA)--in livers of mice at various time intervals after infection with Schistosoma mansoni. For the demonstration of these antigens at the electron microscope level use was made of a direct, double immunogold labeling procedure, in which CAA-specific monoclonal antibodies, labeled with 5-nm gold particles, and CCA-specific monoclonal antibodies, labeled with 15-nm gold particles, were used. Both antigens were localized in granules and in inclusion bodies of Kupffer cells and granuloma macrophages and it was found that in these compartments the degree of 5- and 15-nm gold labeling increased with the duration of the infection. Sometimes gold particles were also encountered on the cell surface and in endocytotic vesicles of these cells, in endothelial cells, and in the space of Disse. From these data it was concluded that in the liver CAA and CCA were primarily accumulated in granules and inclusion bodies of Kupffer cells and granuloma macrophages. It is discussed whether at these locations both antigens are degraded by lysosomal enzymes and whether these antigens are complexed with antibodies.

Animals↗
PubMed1987

Schistosomal specific nephropathy leading to end-stage renal failure.

In this study 17 patients, 11 with end-stage renal failure and six with nephrotic syndrome were selected. The selection criteria were presence of active intestinal schistosomiasis and absence of any surgical or other medical disease which could explain the renal disease. When examined by light microscopy, kidney biopsies showed membranoproliferative glomerulonephritis in nine, membranous in four, focal segmental glomerulosclerosis in two, sclerosing glomerulonephritis in one case, and no changes in another case. Direct immunofluorescence showed IgG deposits in 13 cases, IgM in 10 and different complement components (C3, C1q) in eight cases. Eluates from the kidney biopsies of the 17 schistosomal as well as six control cases were examined by ELISA against schistosoma mansoni adult worm antigen (AWA). This test showed the presence of antibodies against the AWA in 12 out of 17 of the schistosomal cases, and zero out of six of the controls. When examined by direct IFA using sheep anti-circulating anodic antigen/FITC and by indirect IFA using monoclonal antischistosomal CAA IgG3, kidney biopsies of the ELISA positive cases showed granular deposits of circulating anodic antigen (CAA). We conclude that schistosomal specific nephropathy does exist in the clinical settings and can lead to end-stage renal disease, with CAA probably being a major responsible antigen.

Adolescent↗
PubMed1987

Three monoclonal antibodies with specific binding activity to the excretory system of Schistosoma mansoni: an immunoelectron microscopic study using the gold labeling technique.

This study describes three monoclonal antibodies against the excretory system of Schistosoma mansoni. Immunofluorescence revealed antigens forming part of the excretory system of cercariae, adult worms, and miracidia, which were located on the luminal membranes of flame and first tubule cells by immunoelectron microscopy. These antigens are either structural components of the membranes or they derive from excretory fluid and are absorbed during transport and ultrafiltration. Binding specificity of the monoclonal antibodies was tested by immunoelectrophoresis and competitive immunofluorescence; one or two antigens were recognized by each. Reactivity of the antigens after treatment with 7.5% trichloroacetic acid or Rossman's fixative demonstrates at least partial polysaccharide content.

Animals↗
PubMed1986

Ultrastructural localization of the circulating cathodic antigen in the digestive tract of various life-cycle stages of Schistosoma mansoni.

In the present study the ultrastructural localization of the schistosome-derived circulating cathodic antigen (CCA) within the digestive tract of various life-cycle stages of the blood fluke Schistosoma mansoni has been determined. Use was made of CCA-specific monoclonal antibodies in a two-step gold-labeling procedure. The following results were obtained: In cercariae gold label was found in the cytoplasm and in the luminal surface coat of the gut epithelium. The oesophagus of this life-cycle stage of the parasite showed minimal CCA reactivity, as gold label was limited to the luminal surface coat, locating proximally to the gut. In 3 1/2-week-old worms and in adult male and female worms CCA was demonstrable in the Golgi apparatus, in cytoplasmic vesicles and in the luminal surface coat; in the caudal quarter of the gut of adult worms CCA was also present in lysosome-like bodies. The oesophagus of these worm preparations did not show any CCA reactivity. In miracidia CCA was not present.

Animals↗
PubMed1986

Ultrastructural localization of the circulating anodic antigen in the digestive tract of Schistosoma mansoni using monoclonal antibodies in an immunogold labeling procedure.

The purpose of this study was to determine the ultrastructural localization of a major schistosome circulating antigen-the circulating anodic antigen (CAA)-in the digestive tract of various life cycle stages of Schistosoma mansoni. The presence of CAA was determined by an indirect gold-labeling procedure using CAA-specific monoclonal antibodies. In cercariae, gold label was found in the cytoplasm and in the surface coat of the gut epithelium. A minimal amount of gold particles was also observed in the esophagus epithelium, but this was limited to the luminal surface coat and located proximally to the gut. In 3 1/2-week-old worms and in adult male and female worms CAA was demonstrable in the Golgi apparatus, in cytoplasmic vesicles, and in the luminal surface coat of the gut epithelium. As determined in the adult worms, CAA-positive lysosome-like bodies were only encountered in the most caudal quarter of the gut. In the gut lumen CAA was associated with host white blood cells and with a thick layer of finely granular, moderately electron-dense material covering the gut epithelium. The esophagus of these worms did not show CAA reactivity. These results definitely prove that CAA is a gut-specific antigen produced by various life cycle stages of S. mansoni, from the cercarial stage on.

Animals↗
PubMed1985

Immunofluorescent localization of Schistosoma mansoni circulating cathodic antigen in tissues of infected mice using monoclonal antibody.

In the present study the kinetics of the uptake and deposition of the major circulating cathodic antigen (CCA) of Schistosoma mansoni in liver, spleen, and kidney of S. mansoni infected Swiss mice was investigated in relation to the duration of infection and infection dose (50, 100, 200 cercariae). The presence of antigen was studied with a direct immunofluorescence reaction on frozen sections of the mouse organs, using a fluorescein isothiocyanate (FITC)-labelled mouse IgM monoclonal antibody recognizing a repeating epitope of CCA. CCA was demonstrable from 2 weeks post infection (p.i.) onwards in Kupffer cells in the liver, from 3-4 weeks p.i. onwards in macrophages in the marginal zones in the spleen and from 8 weeks p.i. onwards in kidney glomeruli. The immunofluorescence reactions on CCA in kidney glomeruli, however, remained relatively weak.

Animals↗
PubMed1985

The aperture-defined microvolume (ADM) method: automated measurements of enzyme activity using an inverted fluorescence microscope.

The aperture-defined microvolume (ADM) method is based on the relatively constant absorbance or fluorescence of a microvolume of homogeneously coloured material, which is defined by the numerical aperture of the objective. This paper describes the principle of the method and discusses the equipment needed. The main applications reported so far for the measurement of enzyme activity are reviewed. Among these are the quantification of ELISA and DASS tests used in immunology, kinetic studies of enzymes in solution using fluorogenic substrates, and the measurement of enzyme activity in single cells or cell fractions that have been isolated by flow sorting. Typical characteristics of automated ADM measurements include a coefficient of variation of less than 3%, a lower detection limit of a few nanogrammes of fluorescing dye (e.g. 4-methylumbelliferone) and a linear relationship between fluorescence yield and fluorophore concentration over a range of 0.01 to 2.5 nmol. The scanning of Terasaki-type trays and 96-well microtitration plates can be completely automated and requires approximately one minute.

Animals↗
PubMed1985

Comparison of four schistosome excretory-secretory antigens: phenol sulfuric test active peak, cathodic circulating antigen, gut-associated proteoglycan, and circulating anodic antigen.

Several carbohydrate-containing antigens of schistosomes have been characterized and tests for these antigens or for the corresponding antibodies are increasingly being used for the diagnosis and clinical analysis of human schistosomiasis. Phenol sulfuric active peak (PSAP) and cathodic circulating antigen (CCA) are 2 soluble glycoproteins found in adult worms of Schistosoma mansoni. These antigens have some similar characteristics including solubility in trichloroacetic acid and non-binding or weak binding to DEAE cellulose which suggests these 2 compounds to be identical. PSAP and CCA were therefore compared using radioimmunoassays employing monoclonal antibodies to CCA and radiolabeled PSAP as well as inhibitory assays using the original glycoproteins as inhibitors. By these criteria PSAP and CCA were found to be different glycoproteins. Using similar techniques, 2 anodic schistosome compounds, gut-associated proteoglycan (GASP) and circulating anodic antigen (CAA) were found to be identical. We now propose to call this later material GASCAP (gut-associated circulating anodic proteoglycan).

Animals↗
PubMed1984

Presence of Schistosoma mansoni antigens in liver, spleen and kidney of infected mice: a sequential study.

In the present study the kinetics of the uptake and deposition of Schistosoma mansoni antigens in liver, spleen and kidney of S. mansoni infected Swiss mice have been investigated in relation to duration of infection and infection dose (50, 100, 200 cercariae). The presence of antigen was studied with a direct immunofluorescence reaction on frozen sections of the organs, using a number of fluorescein isothiocyanate (FITC)-labeled antisera produced against various antigen preparations isolated from different life-cycle stages of the parasite. The presence of antigen was demonstrable with two of the antisera, directed against the circulating anodic antigen (CAA) and against total soluble egg antigen (SEA). CAA was demonstrable from 1 week post infection (p.i.) onwards in Kupffer cells in the liver, from 2-3 weeks p.i. onwards in macrophages in the marginal zones in the spleen and from 3 weeks onwards in kidney glomeruli. Immunofluorescence reactions on CAA in kidney glomeruli, however, were only weak positive until 12 weeks p.i., whereafter strong positive reactions were found. SEA was demonstrable from 5 weeks p.i. onwards in Kupffer cells in the liver and from 4 weeks p.i. onwards in macrophages of the spleen. In contrast to CAA, SEA was not detectable in kidney glomeruli.

Animals↗
PubMed1984

Schistosoma mansoni: a diamidinophenylindole probe for in vitro death of schistosomula.

The following fluorochromes were studied as probes for discrimination between living and dead Schistosoma mansoni schistosomula: ethidium bromide (EB), propidium iodide (PI), diamidinophenylindole (DAPI), and carboxyfluoresceine diacetate (C-FDA). While schistosomula stained with EB, PI, or C-FDA showed leakage of fluorochrome into the medium, this was not the case with DAPI. Dead schistosomula, which were stained with DAPI, showed an intense blue fluorescence, while living schistosomula were not stained even after prolonged incubation. In addition, the low DAPI concentration (1 microgram/ml) in the medium proved not to be toxic to the schistosomula, nor did it cause any background fluorescence. These properties make DAPI an ideal probe: the viability of S. mansoni schistosomula in cytotoxicity tests can be continuously monitored in tissue culture trays, using an inverted microscope with simultaneous transmitted light and incident fluorescent light illumination.

Animals↗