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Neuried, Germany

Bandilla M.,Friz Biochem | Zimdars A.,Friz Biochem | Neugebauer S.,Ruhr University Bochum | Motz M.,Mikrogen GmbH | And 2 more authors.
Analytical and Bioanalytical Chemistry | Year: 2010

An electrochemical method for the detection of Epstein-Barr virus (EBV) infections is described. The method relies on an immunoassay with electrochemical read-outs based on recombinant antigens. The antigens are immobilised on an Au electrode surface and used to complementarily bind antibodies from serum samples found during different stages of infection with EBV. Thiol chemistry under formation of self-assembled monolayers functions as a means to immobilise the antigens at the Au electrodes. A reporter system consisting of a secondary antibody labelled with alkaline phosphatase is used for electrochemical detection. The feasibility of the assay design is demonstrated and the assay performance is tested against the current gold standard in EBV detection. Close correlation is obtained for the results found for the developed electrochemical immunoassay and a standard line assay. Moreover, the electrochemical immunoassay is combined with a nanoporous electrode system allowing signal amplification by means of redox recycling. An amplification factor of 24 could be achieved. © Springer-Verlag 2010.


Bohm B.,Albert Ludwigs University of Freiburg | Heinzelmann S.,Albert Ludwigs University of Freiburg | Motz M.,Mikrogen GmbH | Bauer G.,Albert Ludwigs University of Freiburg
Biological Chemistry | Year: 2015

Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase. © 2015 by De Gruyter.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: HEALTH.2012.2.3.0-1 | Award Amount: 4.57M | Year: 2012

The SMEs MIKROGEN and BIOSYNEX are well established in the field of diagnostic tests for infectious diseases in humans and perform active research into innovative products. As a critical step to get access to the lucrative market of diagnostic kits for the detection of persistent infections by human papillomaviruses (HPV), the SMEs teamed up with partner UIBK who developed a unique set of immunological tools suitable for this purpose, and two leading European gynecological clinics with longstanding interest in improving clinical management of HPV-associated diseases. Currently used diagnostic tools can detect HPV DNA in cervical smears but fall short of discriminating between transient infections which can spontaneously regress and persistent infections, which have a high chance to progress to high-grade squamous intraepithelial lesions. At this point, the PIPAVIR consortium comes in with the proposal to develop and validate a new diagnostic test for progressive infectious diseases that allows detection, by sandwich-ELISA, of HPV E7 proteins in cervical smears, as markers specific for persistent infections with bad prognosis. In addition, it is planned to develop and validate a diagnostic test strip for rapid detection of viral E7 proteins in cervical smears, most appropriate for alternative diagnostic procedures, such as self-sampling, as well as for the use in low-resource settings. As a major innovative feature, both proposed products use as molecular markers virus-encoded proteins closely related to infection-associated pathology, rather than just the presence of viral DNA or any surrogate markers. Based on the potential of the technology to meet a real clinical need, it can be anticipated that the ability of the participating SME partners to provide and market such superior diagnostic tools will create great business opportunities.


Wacheck S.,Ludwig Maximilians University of Munich | Werres C.,Ludwig Maximilians University of Munich | Mohn U.,Mikrogen GmbH | Dorn S.,Mikrogen GmbH | And 3 more authors.
Foodborne Pathogens and Disease | Year: 2012

Hepatitis E virus (HEV) is an emerging foodborne pathogen with domestic and wild pigs (and likely other species such as deer or rabbits) recognized as reservoir. Pathogenesis in pigs usually leads to an asymptomatic course of disease. Since there is no enzyme-linked immunosorbent assay (ELISA) kit for the detection of anti-HEV antibodies in pigs commercially available, the objective of this study was to assess the seroprevalence in fattening pigs at slaughter and at herd level using a newly developed ELISA based on genotype (GT) 1 and GT 3 in Bavaria, Germany. Based on 516 serum and 198 meat juice samples collected from different herds at four different Bavarian slaughterhouses, the overall seroprevalence of anti-HEV IgG in serum and meat juice samples was 68.6% and 67.6%, respectively. Analyzing the serum for the presence of anti-HEV IgM, 36/516 (7%) were positive for anti-HEV IgM. At herd level, most of the herds were seropositive for anti-HEV antibodies. The present study shows that HEV is widespread among the Bavarian pig population and that some pigs might test positive for anti-HEV IgM even at the age of slaughter. Also, meat juice serves as an equivalent matrix to serum to test for anti-HEV antibodies in pigs. © Copyright 2012, Mary Ann Liebert, Inc.

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