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336 results on '"Schnekenburger, Jürgen"'

9. Quantitative Phase Imaging as Sensitive Screening Method for Nanoparticle-Induced Cytotoxicity Assessment.

Author

Marzi, Anne, Eder, Kai Moritz, Barroso, Álvaro, Kemper, Björn, and Schnekenburger, Jürgen

Subjects
CYTOTOXINS, DIGITAL holographic microscopy, LACTATE dehydrogenase, CELL populations, NANOPARTICLES
Abstract

The assessment of nanoparticle cytotoxicity is challenging due to the lack of customized and standardized guidelines for nanoparticle testing. Nanoparticles, with their unique properties, can interfere with biochemical test methods, so multiple tests are required to fully assess their cellular effects. For a more reliable and comprehensive assessment, it is therefore imperative to include methods in nanoparticle testing routines that are not affected by particles and allow for the efficient integration of additional molecular techniques into the workflow. Digital holographic microscopy (DHM), an interferometric variant of quantitative phase imaging (QPI), has been demonstrated as a promising method for the label-free assessment of the cytotoxic potential of nanoparticles. Due to minimal interactions with the sample, DHM allows for further downstream analyses. In this study, we investigated the capabilities of DHM in a multimodal approach to assess cytotoxicity by directly comparing DHM-detected effects on the same cell population with two downstream biochemical assays. Therefore, the dry mass increase in RAW 264.7 macrophages and NIH-3T3 fibroblast populations measured by quantitative DHM phase contrast after incubation with poly(alkyl cyanoacrylate) nanoparticles for 24 h was compared to the cytotoxic control digitonin, and cell culture medium control. Viability was then determined using a metabolic activity assay (WST-8). Moreover, to determine cell death, supernatants were analyzed for the release of the enzyme lactate dehydrogenase (LDH assay). In a comparative analysis, in which the average half-maximal effective concentration (EC50) of the nanocarriers on the cells was determined, DHM was more sensitive to the effect of the nanoparticles on the used cell lines compared to the biochemical assays. [ABSTRACT FROM AUTHOR]

Published
2024
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19. Gut microbiome as a response marker for pancreatic enzyme replacement therapy in a porcine model of exocrine pancreas insufficiency

Author

Ritz, Sabrina, Opper, Daniela, Wami, Haleluya T., Tegelkamp, Karin, Dobrindt, Ulrich, Schnekenburger, Jürgen, and Universitäts- und Landesbibliothek Münster

Subjects
Pancreatic enzyme replacement therapy, Bacteria, Swine, 610 Medicine and health, Research, Exocrine pancreatic insufficiency, lcsh:QR1-502, Gut microbiota, lcsh:Microbiology, Pancreas, Exocrine, Gastrointestinal Microbiome, α-diversity, β-diversity, Disease Models, Animal, Feces, RNA, Ribosomal, 16S, Medicine and health, Animals, Humans, Swine, Miniature, Enzyme Replacement Therapy, Female, ddc:610
Abstract

Background: Exocrine pancreatic insufficiency (EPI) is characterized by the loss of active pancreatic enzymes and a resulting severely reduced food digestion. EPI therapy requires orally applied pancreatic enzyme replacement. The gut microbiome is a known mediator of intestinal diseases and may influence the outcome of EPI and the effects of a pancreatic enzyme replacement therapy (PERT). Here, we analyzed the effects of EPI and PERT on the gut microbiome in the model of pancreatic duct ligated minipigs. Results: The microbial community composition in pig feces was analyzed by next generation sequencing of 16S rRNA amplicons. The data were evaluated for α- and β-diversity changes and changes at the different Operational Taxonomic Unit (OTU) levels by Shannon–Wiener and inverse Simpson index calculation as well as by Principal Coordinates Analysis based on Bray–Curtis dissimilarity. Microbial α-diversity was reduced after EPI induction and reverted to nearly healthy state after PERT. Analysis of microbial composition and β-diversity showed distinctive clusters of the three study groups and a change towards a composition comparable to healthy animals upon PERT. The relative abundance of possible pathobionts like Escherichia/Shigella, Acinetobacter or Stenotrophomonas was reduced by PERT. Conclusion: These data demonstrate that EPI-induced dysbiosis could be reverted by PERT to a nearly healthy state. Elevated α-diversity and the reduction of bacterial overgrowth after PERT promises benefits for EPI patients. Non-invasive microbiome studies may be useful for EPI therapy monitoring and as marker for response to PERT., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

Published
2023

21. Contributors

Author

Alenius, Harri, primary, Beezhold, Don, additional, Bergamaschi, Enrico, additional, Boraschi, Diana, additional, Bouwmeester, Hans, additional, Campagnolo, Luisa, additional, Chen, Chunying, additional, de Jong, Wim H., additional, Doak, Shareen H., additional, Docter, Dominic, additional, Donaldson, Ken, additional, Duffin, Rodger, additional, Duschl, Albert, additional, Dusinska, Maria, additional, Epa, Vidana, additional, Fadeel, Bengt, additional, Larese Filon, Francesca, additional, Guseva Canu, Irina, additional, Gwinn, Maureen R., additional, Hirose, Akihiro, additional, Hougaard, Karin S., additional, Jepson, Mark A., additional, Kanno, Jun, additional, Knauer, Shirley K., additional, Landsiedel, Robert, additional, Le, Tu C., additional, Liu, Ying, additional, Lu, Xuefei, additional, Magrini, Andrea, additional, Mattsson, Mats-Olof, additional, Mech, Agnieszka, additional, Mills, Nicholas L., additional, Monteiro-Riviere, Nancy A., additional, Pietroiusti, Antonio, additional, Poland, Craig A., additional, Prina-Mello, Adriele, additional, Raftis, Jennifer B., additional, Rasmussen, Kirsten, additional, Rauscher, Hubert, additional, Rundén-Pran, Elise, additional, Sauer, Ursula G., additional, Savolainen, Kai, additional, Schnekenburger, Jürgen, additional, Shurin, Galina V., additional, Shurin, Michael R., additional, Shvedova, Anna A., additional, Simkó, Myrtill, additional, Sokull-Klüttgen, Birgit, additional, Stauber, Roland H., additional, Tran, Lang, additional, Westmeier, Dana, additional, Winkler, Dave, additional, Yokel, Robert A., additional, Yu, Il Je, additional, Zhu, Tao, additional, and Zhu, Yong, additional

Published
2017
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23. Pre-validation of a reporter gene assay for oxidative stress for the rapid screening of nanobiomaterials

Author

Martin, Sebastin, primary, de Haan, Laura, additional, Miro Estruch, Ignacio, additional, Eder, Kai Moritz, additional, Marzi, Anne, additional, Schnekenburger, Jürgen, additional, Blosi, Magda, additional, Costa, Anna, additional, Antonello, Giulia, additional, Bergamaschi, Enrico, additional, Riganti, Chiara, additional, Beal, David, additional, Carrière, Marie, additional, Taché, Olivier, additional, Hutchison, Gary, additional, Malone, Eva, additional, Young, Lesley, additional, Campagnolo, Luisa, additional, La Civita, Fabio, additional, Pietroiusti, Antonio, additional, Devineau, Stéphanie, additional, Baeza, Armelle, additional, Boland, Sonja, additional, Zong, Cai, additional, Ichihara, Gaku, additional, Fadeel, Bengt, additional, and Bouwmeester, Hans, additional

Published
2022
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24. Pre-validation of a reporter gene assay for oxidative stress for the rapid screening of nanobiomaterials

Author

Martin, Sebastin, de Haan, Laura, Miro Estruch, Ignacio, Eder, Kai Moritz, Marzi, Anne, Schnekenburger, Jürgen, Blosi, Magda, Costa, Anna, Antonello, Giulia, Bergamaschi, Enrico, Riganti, Chiara, Beal, David, Carrière, Marie, Taché, Olivier, Hutchison, Gary, Malone, Eva, Young, Lesley, Campagnolo, Luisa, La Civita, Fabio, Pietroiusti, Antonio, Devineau, Stéphanie, Baeza, Armelle, Boland, Sonja, Zong, Cai, Ichihara, Gaku, Fadeel, Bengt, Bouwmeester, Hans, Martin, Sebastin, de Haan, Laura, Miro Estruch, Ignacio, Eder, Kai Moritz, Marzi, Anne, Schnekenburger, Jürgen, Blosi, Magda, Costa, Anna, Antonello, Giulia, Bergamaschi, Enrico, Riganti, Chiara, Beal, David, Carrière, Marie, Taché, Olivier, Hutchison, Gary, Malone, Eva, Young, Lesley, Campagnolo, Luisa, La Civita, Fabio, Pietroiusti, Antonio, Devineau, Stéphanie, Baeza, Armelle, Boland, Sonja, Zong, Cai, Ichihara, Gaku, Fadeel, Bengt, and Bouwmeester, Hans

Abstract

Engineered nanomaterials have been found to induce oxidative stress. Cellular oxidative stress, in turn, can result in the induction of antioxidant and detoxification enzymes which are controlled by the nuclear erythroid 2-related factor 2 (NRF2) transcription factor. Here, we present the results of a pre-validation study which was conducted within the frame of BIORIMA (“biomaterial risk management”) an EU-funded research and innovation project. For this we used an NRF2 specific chemically activated luciferase expression reporter gene assay derived from the human U2OS osteosarcoma cell line to screen for the induction of the NRF2 mediated gene expression following exposure to biomedically relevant nanobiomaterials. Specifically, we investigated Fe3O4-PEG-PLGA nanomaterials while Ag and TiO2 “benchmark” nanomaterials from the Joint Research Center were used as reference materials. The viability of the cells was determined by using the Alamar blue assay. We performed an interlaboratory study involving seven different laboratories to assess the applicability of the NRF2 reporter gene assay for the screening of nanobiomaterials. The latter work was preceded by online tutorials to ensure that the procedures were harmonized across the different participating laboratories. Fe3O4-PEG-PLGA nanomaterials were found to induce very limited NRF2 mediated gene expression, whereas exposure to Ag nanomaterials induced NRF2 mediated gene expression. TiO2 nanomaterials did not induce NRF2 mediated gene expression. The variability in the results obtained by the participating laboratories was small with mean intra-laboratory standard deviation of 0.16 and mean inter laboratory standard deviation of 0.28 across all NRF2 reporter gene assay results. We conclude that the NRF2 reporter gene assay is a suitable assay for the screening of nanobiomaterial-induced oxidative stress responses.

Published
2022

26. Digital Holographic Microscopy for Label-Free Detection of Leukocyte Alternations Associated with Perioperative Inflammation after Cardiac Surgery

Author

Steike, David Rene, Heßler, Michael, Korsching, Eberhard Ulrich, Lehmann, Florian Michael, Schmidt, Christina, Ertmer, Christian, Schnekenburger, Jürgen, Eich, Hans-Theodor, Kemper, Björn, Greve, Burkhard, and Universitäts- und Landesbibliothek Münster

Subjects
610 Medicine and health, Medicine and health, quantitative phase imaging, digital holographic microscopy, flow cytometry, label free, cardiac surgery, CPB, systemic inflammation, epinephrine, ddc:610
Abstract

In a prospective observational pilot study on patients undergoing elective cardiac surgery with cardiopulmonary bypass, we evaluated label-free quantitative phase imaging (QPI) with digital holographic microscopy (DHM) to describe perioperative inflammation by changes in biophysical cell properties of lymphocytes and monocytes. Blood samples from 25 patients were investigated prior to cardiac surgery and postoperatively at day 1, 3 and 6. Biophysical and morphological cell parameters accessible with DHM, such as cell volume, refractive index, dry mass, and cell shape related form factor, were acquired and compared to common flow cytometric blood cell markers of inflammation and selected routine laboratory parameters. In all examined patients, cardiac surgery induced an acute inflammatory response as indicated by changes in routine laboratory parameters and flow cytometric cell markers. DHM results were associated with routine laboratory and flow cytometric data and correlated with complications in the postoperative course. In a subgroup analysis, patients were classified according to the inflammation related C-reactive protein (CRP) level, treatment with epinephrine and the occurrence of postoperative complications. Patients with regular courses, without epinephrine treatment and with low CRP values showed a postoperative lymphocyte volume increase. In contrast, the group of patients with increased CRP levels indicated an even further enlarged lymphocyte volume, while for the groups of epinephrine treated patients and patients with complicative courses, no postoperative lymphocyte volume changes were detected. In summary, the study demonstrates the capability of DHM to describe biophysical cell parameters of perioperative lymphocytes and monocytes changes in cardiac surgery patients. The pattern of correlations between biophysical DHM data and laboratory parameters, flow cytometric cell markers, and the postoperative course exemplify DHM as a promising diagnostic tool for a characterization of inflammatory processes and course of disease., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Published
2022
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28. A JAM-A–tetraspanin–αvβ5 integrin complex regulates contact inhibition of locomotion

Author

Kummer, Daniel, primary, Steinbacher, Tim, additional, Thölmann, Sonja, additional, Schwietzer, Mariel Flavia, additional, Hartmann, Christian, additional, Horenkamp, Simone, additional, Demuth, Sabrina, additional, Peddibhotla, Swetha S.D., additional, Brinkmann, Frauke, additional, Kemper, Björn, additional, Schnekenburger, Jürgen, additional, Brandt, Matthias, additional, Betz, Timo, additional, Liashkovich, Ivan, additional, Kouzel, Ivan U., additional, Shahin, Victor, additional, Corvaia, Nathalie, additional, Rottner, Klemens, additional, Tarbashevich, Katsiaryna, additional, Raz, Erez, additional, Greune, Lilo, additional, Schmidt, M. Alexander, additional, Gerke, Volker, additional, and Ebnet, Klaus, additional

Published
2022
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32. Digital Holographic Microscopy for Label-Free Detection of Leukocyte Alternations Associated with Perioperative Inflammation after Cardiac Surgery

Author

Steike, David Rene, primary, Hessler, Michael, additional, Korsching, Eberhard, additional, Lehmann, Florian, additional, Schmidt, Christina, additional, Ertmer, Christian, additional, Schnekenburger, Jürgen, additional, Eich, Hans Theodor, additional, Kemper, Björn, additional, and Greve, Burkhard, additional

Published
2022
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37. Shot-noise limited, supercontinuum-based optical coherence tomography

Author

Rao D. S, Shreesha, Jensen, Mikkel, Grüner-Nielsen, Lars, Olsen, Jesper Toft, Heiduschka, Peter, Kemper, Björn, Schnekenburger, Jürgen, Glud, Martin, Mogensen, Mette, Israelsen, Niels Møller, Bang, Ole, Rao D. S, Shreesha, Jensen, Mikkel, Grüner-Nielsen, Lars, Olsen, Jesper Toft, Heiduschka, Peter, Kemper, Björn, Schnekenburger, Jürgen, Glud, Martin, Mogensen, Mette, Israelsen, Niels Møller, and Bang, Ole

Abstract

We present the first demonstration of shot-noise limited supercontinuum-based spectral domain optical coherence tomography (SD-OCT) with an axial resolution of 5.9 μm at a center wavelength of 1370 nm. Current supercontinuum-based SD-OCT systems cannot be operated in the shot-noise limited detection regime because of severe pulse-to-pulse relative intensity noise of the supercontinuum source. To overcome this disadvantage, we have developed a low-noise supercontinuum source based on an all-normal dispersion (ANDi) fiber, pumped by a femtosecond laser. The noise performance of our 90 MHz ANDi fiber-based supercontinuum source is compared to that of two commercial sources operating at 80 and 320 MHz repetition rate. We show that the low-noise of the ANDi fiber-based supercontinuum source improves the OCT images significantly in terms of both higher contrast, better sensitivity, and improved penetration. From SD-OCT imaging of skin, retina, and multilayer stacks we conclude that supercontinuum-based SD-OCT can enter the domain of shot-noise limited detection.

Published
2021

50. Long - term follow up of a simplified and less burdened pancreatic duct ligation model of exocrine pancreatic insufficiency in Goettingen Minipigs

Author

Luu, Andreas Minh, primary, Brock, Alexander, additional, Ritz, Sabrina, additional, Junghänel, Sandra, additional, Aldag, Ingo, additional, Edskes, Stella, additional, Hartmann, Marcus, additional, Hessler, Michael, additional, Praktiknjo, Michael, additional, Arnemann, Philip, additional, Ertmer, Christian, additional, Uhl, Waldemar, additional, Schnekenburger, Jürgen, additional, and Herzog, Torsten, additional

Published
2020
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