Search

Your search keyword '"Kopp, Markus"' showing total 154 results
Start Over Author "Kopp, Markus"
154 results on '"Kopp, Markus"'

9. Benchmark for Performance Evaluation of SHACL Implementations in Graph Databases

Author

Schaffenrath, Robert, Proksch, Daniel, Kopp, Markus, Albasini, Iacopo, Panasiuk, Oleksandra, Fensel, Anna, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Gutiérrez-Basulto, Víctor, editor, Kliegr, Tomáš, editor, Soylu, Ahmet, editor, Giese, Martin, editor, and Roman, Dumitru, editor

Published
2020
Full Text
View/download PDF

10. Diagnostic Accuracy and Performance Analysis of a Scanner-Integrated Artificial Intelligence Model for the Detection of Intracranial Hemorrhages in a Traumatology Emergency Department

Author

Kiefer, Jonas, primary, Kopp, Markus, additional, Ruettinger, Theresa, additional, Heiss, Rafael, additional, Wuest, Wolfgang, additional, Amarteifio, Patrick, additional, Stroebel, Armin, additional, Uder, Michael, additional, and May, Matthias Stefan, additional

Published
2023
Full Text
View/download PDF

12. Diagnostic Challenges and Imaging Considerations for Intraparotid Facial Nerve Schwannoma: A Case Report and Literature Review.

Author

Luzha, Jeton, Kopp, Markus, Wiesmüller, Marco, Taha, Lava, Rupp, Robin, Mantsopoulos, Konstantinos, Koch, Michael, Iro, Heinrich Iro, and Sievert, Matti

Subjects
*FACIAL nerve, *LITERATURE reviews, *SCHWANNOMAS, *DIAGNOSTIC imaging, *DIFFUSION magnetic resonance imaging, *MAGNETIC resonance imaging
Abstract

Objective: Rare disease Background: A mass in the parotid gland usually indicates parotid gland neoplasia. Warthin tumors or pleomorphic adenomas are common differential diagnoses. Less frequently, other differential diagnoses and sites of origin are considered. Schwannomas are rare, benign tumors in the head and neck region. Even more rarely, these tumors occur in the intraparotid course of the facial nerve. In the following, we report about 2 patients in whom a mass in the right parotid gland was found incidentally during magnetic resonance imaging (MRI). Case Reports: We reviewed data from the literature on intraparotid facial nerve schwannomas (IPFNS) and compared them with those from our cases. The focus was on data such as clinical history, clinical symptoms, electroneurography, and various imaging modalities, such as ultrasonography and MRI combined with diffusion-weighted imaging. Conclusions: It is challenging to distinguish facial nerve schwannomas from other neoplasms. Patient's history, clinical symptoms, MRI examination with diffusion-weighted imaging, and high-resolution ultrasound imaging are decisive factors for diagnosis and should be performed when IPFNS is suspected. Diagnosis and therapy for IPFNS remain challenging. A wait-and-scan approach could be an option for patients with small tumors and good facial nerve function. On the other hand, patients with advanced tumors associated with limited facial nerve function can benefit from surgical approaches or stereotactic radiosurgery. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

21. Apparent Diffusion Coefficient (ADC) Histogram Analysis in Parotid Gland Tumors: Evaluating a Novel Approach for Differentiation between Benign and Malignant Parotid Lesions Based on Full Histogram Distributions

Author

Hepp, Tobias, primary, Wuest, Wolfgang, additional, Heiss, Rafael, additional, May, Matthias Stefan, additional, Kopp, Markus, additional, Wetzl, Matthias, additional, Treutlein, Christoph, additional, Uder, Michael, additional, and Wiesmueller, Marco, additional

Published
2022
Full Text
View/download PDF

24. Phantom study for comparison between computed tomography- and C-Arm computed tomography-guided puncture applied by residents in radiology

Author

Meine, Timo C., additional, Hinrichs, Jan B., additional, Werncke, Thomas, additional, Afat, Saif, additional, Biggemann, Lorenz, additional, Bucher, Andreas, additional, Büttner, Martina, additional, Christner, Sara, additional, Dethlefsen, Ebba, additional, Engel, Hannes, additional, Gerwing, Mirjam, additional, Getzin, Tobias, additional, Gräger, Stephanie, additional, Gresser, Eva, additional, Grunz, Jan-Peter, additional, Harder, Felix, additional, Heidenreich, Julius, additional, Hitpaß, Lea, additional, Jakobi, Kristina, additional, Janisch, Michael, additional, Kocher, Nadja, additional, Kopp, Markus, additional, Lennartz, Simon, additional, Martin, Ole, additional, Moher Alsady, Tawfik, additional, Pamminger, Matthias, additional, Pedersoli, Frederico, additional, Piechotta, Paula Louise, additional, Platz Batista da Silva, Natascha, additional, Raudner, Marcus, additional, Roehrich, Sebastian, additional, Schindler, Philipp, additional, Schwarze, Vincent, additional, Seppelt, Danilo, additional, Sieren, Malte M., additional, Spurny, Manuela, additional, Starekova, Jitka, additional, Storz, Corinna, additional, Wiesmüller, Marco, additional, Zopfs, David, additional, Ringe, Kristina Imeen, additional, Meyer, Bernhard C., additional, and Wacker, Frank K., additional

Published
2021
Full Text
View/download PDF

26. Personalized Chest Computed Tomography

Author

May, Matthias, primary, Heiss, Rafael, additional, Koehnen, Julia, additional, Wetzl, Matthias, additional, Wiesmueller, Marco, additional, Treutlein, Christoph, additional, Braeuer, Lars, additional, Uder, Michael, additional, and Kopp, Markus, additional

Published
2021
Full Text
View/download PDF

27. Potential for Radiation Dose Reduction in Dual-Source Computed Tomography of the Lung in the Pediatric and Adolescent Population Compared to Digital Radiography

Author

Wetzl, Matthias, primary, May, Matthias Stefan, additional, Weinmann, Daniel, additional, Hammon, Matthias, additional, Kopp, Markus, additional, Ruppel, Renate, additional, Trollmann, Regina, additional, Woelfle, Joachim, additional, Uder, Michael, additional, and Rompel, Oliver, additional

Published
2021
Full Text
View/download PDF

28. Personalized computed tomography – Automated estimation of height and weight of a simulated digital twin using a 3D camera and artificial intelligence

Author

Geissler, Frederik, additional, Heiß, Rafael, additional, Kopp, Markus, additional, Wiesmüller, Marco, additional, Saake, Marc, additional, Wuest, Wolfgang, additional, Wimmer, Andreas, additional, Prell, Veronika, additional, Uder, Michael, additional, and May, Matthias Stefan, additional

Published
2020
Full Text
View/download PDF

32. Feasibility and advantages of tablet-based structured medical history and informed patient consent prior to computed tomography

Author

Kopp, Markus

Subjects
genetic structures, eHealth, CT, Structured reporting
Abstract

Aims and objectives Methods and materials Results Conclusion Personal information References, Aims and objectives: Digitalization has the potential to increasingly spread into hospitals when improved software technology and mobile devices such as tablets computers are used 1-4 .However, informed patient consent is often archived in hardcopy form and information...

Published
2019
Full Text
View/download PDF

33. Personalised examination protocols related to clinical indication in unenhanced thoracic computed tomography

Author

Kopp, Markus

Subjects
Radiation safety, genetic structures, Radioprotection / Radiation dose, CT
Abstract

Aims and objectives Methods and materials Results Conclusion Personal information References, Aims and objectives: Contemporary computed tomography (CT) of the chest is a very common examination with high clinical implications. To minimize stochastic risk of malignancy due to radiation dose every CT examination shouldhave the lowest radiation exposure as...

Published
2019
Full Text
View/download PDF

34. Analysis of a magnetoelastic sensor

Author

Copeland, Richard L., Kopp, Markus, and O'Handley, R.C.

Subjects
Sensors -- Design and construction, Magnetization -- Models, Magnetic materials -- Analysis, Eddy currents (Electric) -- Analysis, Finite element method -- Usage, Business, Electronics, Electronics and electrical industries
Abstract

A brief description of a magnetoelastic sensor is presented. The relationship between ac resonance and dc bias magnetization is explained. A 3D magnetostatic finite element model is used to describe the dc bias magnetization using either a uniform solenoidal or permanent magnet source. An analysis of the equation of motion of the magnetoelastic sensor is derived and an equivalent circuit model describing the ac resonance behavior is presented. The results of these models agree well with experimental data.

Published
1994

38. Characterization and Interrelations of One-Carbon Metabolites in Tissues, Erythrocytes, and Plasma in Mice with Dietary Induced Folate Deficiency

Author

Kopp, Markus, Morisset, Rosalie, and Rychlik, Michael

Subjects
Male, S-Adenosylmethionine, Erythrocytes, S-adenosylhomocysteine, folate metabolism, Brain, Heart, homocysteine, Folic Acid Deficiency, Kidney, Article, folate deficiency, Carbon, Diet, Mice, Inbred C57BL, Mice, Folic Acid, Methionine, methionine metabolism, Liver, Animals, Biomarkers
Abstract

Studies on one-carbon metabolism for the assessment of folate deficiency have focused on either metabolites of folate metabolism or methionine cycle. To bridge the gap between deficiency markers in these pathways we designed a dietary induced folate deficiency study using male C57BL/6N mice. After weaning (3 weeks) mice were fed a defined control diet (1 week) before being fed a folate deficient diet (n = 6 mice) and the control diet (n = 6 mice) for 12 additional weeks. Thereafter, we determined total homocysteine in plasma and folate in erythrocytes as well as S-adenosylmethionine, S-adenosylhomocysteine, and six folate vitamers in tissues including 5-methyltetrahydrofolate, 5-formyltetrahydrofolate, 5,10-methenyltetrahydrofolate, tetrahydrofolate, 10-formylfolic acid, and folic acid by means of stable isotope dilution assays coupled with liquid chromatography tandem mass spectrometry. In all organs, except heart (mainly 5-mehtyltetrahydrofolate), tetrahydrofolate constitutes the main vitamer. Moreover, in liver tetrahydrofolate was most abundant followed by 5-methyltetrahydrofolate (heart: tetrahydrofolate), 5-formyltetrahydrofolate, and 5,10-methenyltetrahydrofolate. Because of the significant decrease (p < 0.05) of folate status and S-adenosylmethionine/S-adenosylhomocysteine ratio accompanied with increasing S-adenosylhomocysteine (p < 0.05), hepatocytes are most susceptible to folate deficiency. To the best of our knowledge, we herein present the first method for simultaneous quantitation of eight metabolites for both folate and methionine cycle in one tissue sample, tHcy in plasma, and erythrocyte folate to shed light on physiological interrelations of one-carbon metabolism.

Published
2017

39. Assessing Volumetric Absorptive Microsampling Coupled with Stable Isotope Dilution Assay and Liquid Chromatography–Tandem Mass Spectrometry as Potential Diagnostic Tool for Whole Blood 5-Methyltetrahydrofolic Acid

Author

Kopp, Markus and Rychlik, Michael

Subjects
dried blood, 5-methyltetrahydrofolic acid, volumetric absorptive microsampler, Mitra™, folate status, Methods, Nutrition
Abstract

Volumetric absorptive microsamplers (VAMS) have been developed recently as a promising tool for clinical blood sampling. Compared to dried blood spot samples analyzed by accurate stable isotope dilution assays (SIDAs), the new technique could provide further substantial miniaturizing of folate assays by eliminating hematocrit effects and uneven analyte distribution within the sample. Herein, we present a miniaturized SIDA coupled with LC-MS/MS measurement of 5-methyltetrahydrofolic acid as main folate vitamer in whole blood (WB) using [13C5]-5-methyltetrahydrofolic acid as internal standard. Elution and extraction of only 10.8 μL-dried WB were carried out by centrifugation followed by enzymatic treatment for polyglutamate deconjugation. Matrix separation was achieved by heating and centrifugation. To verify applicability, WB folate status of 11 volunteers was screened. Limits of detection and limits of quantitation were 9 and 26 nmol·L−1, respectively, which is sufficiently low for screening folate status. Recoveries were 97 (±5.8), 99 (±2.8), and 96 (±6.1)% for 800, 400, and 200 nmol L−1 5-methyltetrahydrofolic acid, respectively. Precision of the LC-MS/MS instrument and inter-assay precision trials revealed CVs of 8.1 and 3.5% (294 nmol L−1), respectively, thus confirming reproducible and precise quantitation. Compared to fresh WB, no significant degradation of 5-methyltetrahydrofolate was observed after 2.5 h of drying at room temperature. VAMS 5-CH3-H4folate was stable for at least 3 weeks at −20°C. In our pilot study, accurate and diagnostically conclusive determination of folate status was verified. Nevertheless, blood sampling should be performed by trained individuals to avoid substantial errors concerning the absorbed volume. Endogenous folate in rat serum and chicken pancreas caused a significant background especially at low blood 5-CH3-H4folate levels and, thus, for polyglutamate deconjugation, these background folates or alternative mixtures need to be removed. The superior feasibility of a minimized blood collection with VAMS allows further progress regarding time- and cost-effective methodologies in newborn or population screenings for 5-methyltetrahydrofolate status. Further steps toward minimization could include an automated assay coupled with UPLC-MS/MS.

Published
2017

40. Measurements of Intra- and Extra-Cellular 5-Methyltetrahydrofolate Indicate that Bifidobacterium Adolescentis DSM 20083T and Bifidobacterium Pseudocatenulatum DSM 20438T Do Not Actively Excrete 5-Methyltetrahydrofolate In vitro

Author

Kopp, Markus, Dürr, Kerstin, Steigleder, Matthias, Clavel, Thomas, and Rychlik, Michael

Subjects
gut microbiota, ddc:570, folate synthesis, bifidobacteria, LC-MS/MS, folate bioavailability, stable isotope dilution assay, Microbiology, Original Research
Abstract

Frontiers in microbiology 8, 445 (2017). doi:10.3389/fmicb.2017.00445, Published by Frontiers Media, Lausanne

Published
2017

50. Measurements of Intra-and Extra-Cellular 5-Methyltetrahydrofolate Indicate that Bifidobacterium Adolescentis DSM 20083T and Bifidobacterium Pseudocatenulatum DSM 20438T Do Not Actively Excrete 5-Methyltetrahydrofolate In vitro.

Author

Kopp, Markus, Dürr, Kerstin, Steigleder, Matthias, Clavel, Thomas, and Rychlik, Michael

Subjects
5-Methyltetrahydrofolate, BIFIDOBACTERIUM
Abstract

Certain intestinal bifidobacteria have the ability to synthesize folates. In vitro experiments revealed a high production, cellular accumulation, and release of reduced folate vitamers like 5-methyltetrahydrofolate and tetrahydrofolate in folate-free medium (FFM). However, it is still unclear to which extent synthesized folates are polyglutamylated and probably not available for transport, and if they are actively released by excretion. To address these questions, we characterized intra- and extra-cellular pteroylmonoglutamates and polyglutamylated 5-methyltetrahydrofolate (5-CH3-H4PteGlu2-4) in Bifidobacterium adolescentis DSM 20083T and Bifidobacterium pseudocatenulatum DSM 20438T in vitro. Folates were measured by means of stable isotope dilution assays (SIDA) coupled with LC-MS/MS analysis using [2H4]-5-methyltetrahydrofolic acid, [2H4]-tetrahydrofolic acid, and [2H4]-5-formyltetrahydrofolic acid as internal standards. Cell viability was examined by fluorescence microscopy. Quantitation of folate production by B. adolescentis during the stationary phase revealed a linear increase of dead cells paralleled by increasing concentration of 5-formyltetrahydrofolate and 5-methyltetrahydrofolate (100% 5-CH3-H4PteGlu4) in FFM, whereas the intracellular concentrations of these vitamers remained constant. After 24 h, B. adolescentis (125mg cells, wet weight) produced a total amount of 0.846 nmol 5-CH3-H4folate: 0.385 ± 0.059 nmol (46 ± 7%) and 0.461 ± 0.095 nmol (54 ± 11%) measured in the intracellular (viable cells; 52 ± 3% measured by fluorescence microscopy) and extracellular (lysed cells; 48 ± 3%) fraction, respectively. For B. pseudocatenulatum (124mg cells, wet weight), 1.135 nmol 5-CH3-H4folate was produced after 24 h, and a similar proportionality between intra- and extra-cellular folate concentrations and viable/lysed cells was observed. These results indicate that the strains tested produce and accumulate 5-CH3-H4PteGlu4 for cellular metabolism, and that extracellular concentrations of the vitamer arise from cell lysis. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results