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C Verhofstede

Publications and source records attributed to C Verhofstede.

25 records · Page 2Linked to original sources

Evaluation of immunoblotting for the detection of Toxoplasma gondii immunoglobulin M antibodies.

Immunoblot analysis was used to detect human IgM antibodies to Toxoplasma gondii in 20 patients with recent toxoplasmosis, 30 immune individuals, 30 non-immune individuals, and 24 children less then two years old. Analysis of the IgM strips revealed that specific IgM antibodies detectable after a recent Toxoplasma gondii infection react with the same antigens as the 'natural' antibodies present in the sera of immune and non-immune individuals and in the sera of young children. These data indicate that immunoblotting is not useful as a reference method for Toxoplasma gondii IgM detection, and suggest that improvement of the specificity of IgM detection will remain difficult.

Animals↗

The subcellular localization of the neu protein in human normal and neoplastic cells.

We have examined the subcellular localization of the neu protein by immunohistochemistry and immuno-electron microscopy, associated with immunoblotting of normal and neoplastic tissues with 2 monoclonal antibodies (MAbs). Immunoelectron microscopy clearly reveals that neu protein resides only on the lateral plasma membrane of the simple epithelium of the breast and on the plasma membrane of malignant breast cells. It is also found on the membranes of the microvilli and the apical vacuoles of the cells of the proximal convoluted tubule of the kidney. In the cytoplasm, the only immunoreactivity detected with both antibodies was on the membrane of the mitochondrial cristae of normal and malignant cells. Immunoblotting reveals that the molecular weight of the membrane protein is 185 and 155 kDa for the mitochondrial protein. The cell membrane staining pattern can be revealed by light microscopic immunohistochemistry only in malignant cells and is therefore specific for malignancy. The membrane expression in normal cells cannot be visualized in this way. The mitochondrial reactivity appears as a cytoplasmic granular staining when examined under the light microscope. Similar cytoplasmic staining has been described previously in other studies with other antibodies against the neu protein and has lead to speculation about its function in normal and malignant cells. However, it is demonstrated in this study that it is not the known neu-oncogene product.

Antibodies, Monoclonal↗

Comparison of six commercial enzyme linked immunosorbent assays for detecting IgM antibodies against Toxoplasma gondii.

To evaluate the usefulness of different commercial enzyme linked immunosorbent assays (ELISAs) for the detection of IgM antibodies against Toxoplasma gondii the results of six of these assays for a panel of 81 sera were compared. The following tests were selected: Toxoplasma gondii IgM ELISA (Clark Laboratories), Toxoplasma IgM EIA (Labsystems), Toxo-M EIA (Abbott), Toxonostika M (Organon), Toxo M Enzyme Immunoassay (Hybritech) and Platelia Toxo IgM (Diagnostics Pasteur). An antibody capture ELISA developed at our laboratory was used as the reference test. An IgM immunoblotting assay was also performed. Four (Toxoplasma IgM EIA, Tox-M EIA, Toxonostika M, and Platelia Toxo IgM) of the commercial IgM ELISAs gave a high sensitivity and a high specificity. Toxo-M EIA, Toxonostika M, Toxoplasma IgM EIA and the Toxo M Enzyme Immunoassay were too insensitive, and the Toxoplasma gondii IgM ELISA was both insensitive and unspecific. No remarkable differences were observed between the results of indirect or antibody capture ELISAs, and between the results of ELISAs performed with polyclonal or monoclonal antibodies.

Animals↗

The infection-stage-related IgG response to Toxoplasma gondii studied by immunoblotting.

The technique of SDS-polyacrylamide gel electrophoresis and immunoblotting was used to study the evolution of the IgG antibody response to Toxoplasma gondii antigens in sequential sera of acutely infected patients. The results show that the IgG immunoblot pattern can be a useful marker for the stage of T. gondii infection. A 35-kD antigen elicited the first IgG response soon after exposure. During the course of infection additional bands appeared consecutively, following a constant sequence, to evolve to a late-stage-specific pattern with about 13-15 major bands. This pattern, which was reached at least 4 months after infection, was also found in the immunoblots of 28 patients with a chronic (latent) T. gondii infection.

Acute Disease↗

Ability of enzyme-linked immunosorbent assays to detect early immunoglobulin G antibodies to Toxoplasma gondii.

Two ELISA procedures, one using sonicated antigen coated with carbonate buffer and the other formalin fixed trophozoites with dry coating, differ in their ability to detect early antibodies in toxoplasmosis. In order to identify factors responsible for this difference, seven ELISA systems differing from each other in antigen used and/or coating procedure were compared. Both fixation of the trophozoites with formalin and air-drying of the antigen in the microtiterplate were important factors determining the ability of the assay to detect IgG antibodies in the early stage of infection. Differences in the results of the two ELISA procedures can be used to distinguish between the acute and chronic stages of infection.

Acute Disease↗

Hepatitis C among risk groups for HIV and hepatitis B.

In order to obtain more information on sexual transmission of hepatitis C (HCV) we compared different high-risk groups for HIV and hepatitis B to see if they were seropositive for HCV. A high seroprevalence (38/81) of hepatitis C (HCV) was found among intravenous drug users. Nursing staff (n = 35) and patients of a dialysis unit (n = 57) had a low prevalence of anti-HCV antibodies (0% and 5%, respectively). Serology laboratory technicians also had a very low prevalence (0% out of 29). Among prostitutes (n = 114), healthy homosexual men (n = 132) and HIV-infected homosexual men (n = 31), we found a remarkably low seroprevalence of HCV (3.5%, 0.8% and 0.0% respectively). These data support the view that parenteral exposure to the virus is the most important way of acquiring the infection and that neither heterosexual nor homosexual promiscuity are associated with a high risk of transmission of hepatitis C.

Belgium↗

The AIDS epidemic: the spread of a deadly disease in the biotech era.

In the last two decades we have witnessed the progression of a newly introduced infection in humans. It is sobering that despite a world-wide effort and the tremendous progression of technical capabilities and scientific knowledge we are still not able to control the global epidemic of HIV. In 2004 more than 40 million people were infected. Educational approaches to modify risk-taking behavior is still the most critical component of prevention and the most important measure to limit the spread of the infection. Vaccine development, which is still far from promising, is probably the only way to control the disease in the future.

Acquired Immunodeficiency Syndrome↗