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Solomun T, Cordsmeier L, Hallier DC, Seitz H, Hahn MB. Interaction of a Dimeric Single-Stranded DNA-Binding Protein (G5P) with DNA Hairpins. A Molecular Beacon Study. J Phys Chem B 2023; 127:8131-8138. [PMID: 37704207 PMCID: PMC10544328 DOI: 10.1021/acs.jpcb.3c03669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/23/2023] [Indexed: 09/15/2023]
Abstract
Gene-V protein (G5P/GVP) is a single-stranded (ss)DNA-binding protein (SBP) of bacteriophage f1 that is required for DNA synthesis and repair. In solution, it exists as a dimer that binds two antiparallel ssDNA strands with high affinity in a cooperative manner, forming a left-handed helical protein-DNA filament. Here, we report on fluorescence studies of the interaction of G5P with different DNA oligonucleotides having a hairpin structure (molecular beacon, MB) with a seven base-pair stem (dT24-stem7, dT18-stem7), as well as with DNA oligonucleotides (dT38, dT24) without a defined secondary structure. All oligonucleotides were end-labeled with a Cy3-fluorophore and a BHQ2-quencher. In the case of DNA oligonucleotides without a secondary structure, an almost complete quenching of their strong fluorescence (with about 5% residual intensity) was observed upon the binding of G5P. This implies an exact alignment of the ends of the DNA strand(s) in the saturated complex. The interaction of the DNA hairpins with G5P led to the unzipping of the base-paired stem, as revealed by fluorescence measurements, fluorescence microfluidic mixing experiments, and electrophoretic mobility shift assay data. Importantly, the disruption of ssDNA's secondary structure agrees with the behavior of other single-stranded DNA-binding proteins (SBPs). In addition, substantial protein-induced fluorescence enhancement (PIFE) of the Cy3-fluorescence was observed.
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Affiliation(s)
- Tihomir Solomun
- Bundesanstalt
für Materialforschung und -prüfung (BAM), Berlin 12205, Germany
| | - Leo Cordsmeier
- Bundesanstalt
für Materialforschung und -prüfung (BAM), Berlin 12205, Germany
- Institut
für Chemie, Freie Universität
Berlin, Berlin 14195, Germany
| | - Dorothea C. Hallier
- Bundesanstalt
für Materialforschung und -prüfung (BAM), Berlin 12205, Germany
- Institut
für Biochemie und Biologie, Universität
Potsdam, Potsdam 14476, Germany
- Fraunhofer
Institut für Zelltherapie und Immunologie Institutsteil Bioanalytik
und Bioprozesse IZI-BB, Potsdam 14476, Germany
| | - Harald Seitz
- Institut
für Biochemie und Biologie, Universität
Potsdam, Potsdam 14476, Germany
- Fraunhofer
Institut für Zelltherapie und Immunologie Institutsteil Bioanalytik
und Bioprozesse IZI-BB, Potsdam 14476, Germany
| | - Marc Benjamin Hahn
- Bundesanstalt
für Materialforschung und -prüfung (BAM), Berlin 12205, Germany
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2
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Hallier DC, Smales GJ, Seitz H, Hahn MB. Bio-SAXS of single-stranded DNA-binding proteins: radiation protection by the compatible solute ectoine. Phys Chem Chem Phys 2023; 25:5372-5382. [PMID: 36637121 DOI: 10.1039/d2cp05053f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL-1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
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Affiliation(s)
- Dorothea C Hallier
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), 14476 Potsdam, Germany.,Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
| | - Glen J Smales
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
| | - Harald Seitz
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), 14476 Potsdam, Germany
| | - Marc Benjamin Hahn
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
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3
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Weizel A, Distler T, Detsch R, Boccaccini AR, Seitz H, Budday S. Time-dependent hyper-viscoelastic parameter identification of human articular cartilage and substitute materials. J Mech Behav Biomed Mater 2023; 138:105618. [PMID: 36566662 DOI: 10.1016/j.jmbbm.2022.105618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/13/2022]
Abstract
Numerical simulations are a valuable tool to understand which processes during mechanical stimulations of hydrogels for cartilage replacement influence the behavior of chondrocytes and contribute to the success or failure of these materials as implants. Such simulations critically rely on the correct prediction of the material response through appropriate material models and corresponding parameters. In this study, we identify hyper-viscoelastic material parameters for numerical simulations in COMSOL Multiphysics® v. 5.6 for human articular cartilage and two replacement materials, the commercially available ChondroFillerliquid and oxidized alginate gelatin (ADA-GEL) hydrogels. We incorporate the realistic experimental boundary conditions into an inverse parameter identification scheme based on data from multiple loading modes simultaneously, including cyclic compression-tension and stress relaxation experiments. We provide individual parameter sets for the unconditioned and conditioned responses and discuss how viscoelastic effects are related to the materials' microstructure. ADA-GEL and ChondroFillerliquid exhibit faster stress relaxation than cartilage with lower relaxation time constants, while cartilage has the largest viscoelastic stress contribution. The elastic response predominates in ADA-GEL and ChondroFillerliquid, while the viscoelastic response predominates in cartilage. These results will help to simulate mechanical stimulations, support the development of suitable materials with distinct mechanical properties in the future and provide parameters and insight into the time-dependent material behavior of human articular cartilage.
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Affiliation(s)
- A Weizel
- Chair of Microfluidics, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Rostock, Germany.
| | - T Distler
- Institute of Biomaterials, Department of Materials Science and Engineering, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - R Detsch
- Institute of Biomaterials, Department of Materials Science and Engineering, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - A R Boccaccini
- Institute of Biomaterials, Department of Materials Science and Engineering, Friedrich-Alexander-University Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - H Seitz
- Chair of Microfluidics, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Rostock, Germany
| | - S Budday
- Institute of Applied Mechanics, Department of Mechanical Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
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4
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Pellegrino A, Mükusch S, Seitz V, Stein C, Herberg FW, Seitz H. Transient Receptor Potential Vanilloid 1 Signaling Is Independent on Protein Kinase A Phosphorylation of Ankyrin-Rich Membrane Spanning Protein. Med Sci (Basel) 2022; 10:medsci10040063. [PMID: 36412904 PMCID: PMC9680306 DOI: 10.3390/medsci10040063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
The sensory ion channel transient receptor potential vanilloid 1 (TRPV1) is mainly expressed in small to medium sized dorsal root ganglion neurons, which are involved in the transfer of acute noxious thermal and chemical stimuli. The Ankyrin-rich membrane spanning protein (ARMS) interaction with TRPV1 is modulated by protein kinase A (PKA) mediating sensitization. Here, we hypothesize that PKA phosphorylation sites of ARMS are crucial for the modulation of TRPV1 function, and that the phosphorylation of ARMS is facilitated by the A-kinase anchoring protein 79 (AKAP79). We used transfected HEK293 cells, immunoprecipitation, calcium flux, and patch clamp experiments to investigate potential PKA phosphorylation sites in ARMS and in ARMS-related peptides. Additionally, experiments were done to discriminate between PKA and protein kinase D (PKD) phosphorylation. We found different interaction ratios for TRPV1 and ARMS mutants lacking PKA phosphorylation sites. The degree of TRPV1 sensitization by ARMS mutants is independent on PKA phosphorylation. AKAP79 was also involved in the TRPV1/ARMS/PKA signaling complex. These data show that ARMS is a PKA substrate via AKAP79 in the TRPV1 signaling complex and that all four proteins interact physically, regulating TRPV1 sensitization in transfected HEK293 cells. To assess the physiological and/or therapeutic significance of these findings, similar investigations need to be performed in native neurons and/or in vivo.
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Affiliation(s)
- Antonio Pellegrino
- Fraunhofer Institute for Cell Therapy and Immunology, 14476 Potsdam, Germany
| | - Sandra Mükusch
- Fraunhofer Institute for Cell Therapy and Immunology, 14476 Potsdam, Germany
| | - Viola Seitz
- Institute of Experimental Anaesthesiology, Charité—Universitätsmedizin Berlin, 12203 Berlin, Germany
- Brandenburg Medical School Theodor Fontane, Fehrbelliner Str. 38, 16816 Neuruppin, Germany
| | - Christoph Stein
- Institute of Experimental Anaesthesiology, Charité—Universitätsmedizin Berlin, 12203 Berlin, Germany
| | | | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology, 14476 Potsdam, Germany
- Correspondence: ; +49-331-58187-208
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5
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Polley C, Radlof W, Hauschulz F, Benz C, Sander M, Seitz H. Morphological and mechanical characterisation of three-dimensional gyroid structures fabricated by electron beam melting for the use as a porous biomaterial. J Mech Behav Biomed Mater 2021; 125:104882. [PMID: 34740017 DOI: 10.1016/j.jmbbm.2021.104882] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/23/2021] [Accepted: 10/02/2021] [Indexed: 02/05/2023]
Abstract
Additive manufactured porous biomaterials based on triply periodic minimal surfaces (TPMS) are a highly discussed topic in the literature. With their unique properties in terms of open porosity, large surface area and surface curvature, they are considered to have bone mimicking properties and remarkable osteogenic potential. In this study, scaffolds of gyroid unit cells of different sizes consisting of a Ti6Al4V alloy were manufactured additively by electron beam melting (EBM). The scaffolds were analysed by micro-computed tomography (micro-CT) to determine their morphological characteristics and, subsequently, subjected to mechanical tests to investigate their quasi-static compressive properties and fatigue resistance. All scaffolds showed an average open porosity of 71-81%, with an average pore size of 0.64-1.41 mm, depending on the investigated design. The design with the smallest unit cell shows the highest quasi-elastic gradient (QEG) as well as the highest compressive offset stress and compression strength. Furthermore, the fatigue resistance of all unit cell size (UCS) variations showed promising results. In detail, the smallest unit cells achieved fatigue strength at 106 cycles at 45% of their compressive offset stress, which is comparatively good for additively manufactured porous biomaterials. In summary, it is demonstrated that the mechanical properties can be significantly modified by varying the unit cell size, thus enabling the scaffolds to be specifically tailored to avoid stress shielding and ensure implant safety. Together with the morphological properties of the gyroid unit cells, the fabricated scaffolds represent a promising approach for use as a bone substitute material.
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Affiliation(s)
- C Polley
- Chair of Microfluidics, University of Rostock, Rostock, Germany.
| | - W Radlof
- Institute of Structural Mechanics, University of Rostock, Rostock, Germany
| | - F Hauschulz
- Chair of Microfluidics, University of Rostock, Rostock, Germany
| | - C Benz
- Institute of Structural Mechanics, University of Rostock, Rostock, Germany
| | - M Sander
- Institute of Structural Mechanics, University of Rostock, Rostock, Germany
| | - H Seitz
- Chair of Microfluidics, University of Rostock, Rostock, Germany; Department Life, Light & Matter, University of Rostock, Rostock, Germany
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6
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Blazquez-Navarro A, Dang-Heine C, Wehler P, Roch T, Bauer C, Neumann S, Blazquez-Navarro R, Kurchenko A, Wolk K, Sabat R, Westhoff TH, Olek S, Thomusch O, Seitz H, Reinke P, Hugo C, Sawitzki B, Or-Guil M, Babel N. Risk factors for Epstein-Barr virus reactivation after renal transplantation: Results of a large, multi-centre study. Transpl Int 2021; 34:1680-1688. [PMID: 34448272 DOI: 10.1111/tri.13982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 01/02/2023]
Abstract
Epstein-Barr virus (EBV) reactivation is a very common and potentially lethal complication of renal transplantation. However, its risk factors and effects on transplant outcome are not well known. Here, we have analysed a large, multi-centre cohort (N = 512) in which 18.4% of the patients experienced EBV reactivation during the first post-transplant year. The patients were characterized pre-transplant and two weeks post-transplant by a multi-level biomarker panel. EBV reactivation was episodic for most patients, only 12 patients showed prolonged viraemia for over four months. Pre-transplant EBV shedding and male sex were associated with significantly increased incidence of post-transplant EBV reactivation. Importantly, we also identified a significant association of post-transplant EBV with acute rejection and with decreased haemoglobin levels. No further severe complications associated with EBV, either episodic or chronic, could be detected. Our data suggest that despite relatively frequent EBV reactivation, it had no association with serious complications during the first post-transplantation year. EBV shedding prior to transplantation could be employed as biomarkers for personalized immunosuppressive therapy. In summary, our results support the employed immunosuppressive regimes as relatively safe with regard to EBV. However, long-term studies are paramount to support these conclusions.
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Affiliation(s)
- Arturo Blazquez-Navarro
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Chantip Dang-Heine
- Clinical Study Center (CSC), Berlin Institute of Health, and Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Patrizia Wehler
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Toralf Roch
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | | | | | | | - Andriy Kurchenko
- Department of Clinical Immunology and Allergology, Bogolomets National Medical University, Kiev, Ukraine
| | - Kerstin Wolk
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Psoriasis Research and Treatment Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Robert Sabat
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Psoriasis Research and Treatment Center, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Timm H Westhoff
- Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
| | - Sven Olek
- Ivana Türbachova Laboratory for Epigenetics, Epiontis GmbH, Precision for Medicine Group, Berlin, Germany
| | - Oliver Thomusch
- Klinik für Allgemein- und Viszeralchirurgie, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics und Bioprocesses, Leipzig, Germany
| | - Petra Reinke
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Berlin Center for Advanced Therapies (BeCAT), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Hugo
- Universitätsklinikum Carl Gustav Carus, Medizinische Klinik III - Bereich Nephrologie, Dresden, Germany
| | - Birgit Sawitzki
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Michal Or-Guil
- Systems Immunology Lab, Department of Biology, Humboldt-Universität zu Berlin, Berlin, Germany.,Institute of Medical Immunology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Nina Babel
- Berlin Institute of Health Center for Regenerative Therapies (BCRT): Berlin-Brandenburger Centrum für Regenerative Therapien, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Center for Translational Medicine, Universitätsklinikum der Ruhr-Universität Bochum, Medizinische Klinik I, Herne, Germany
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7
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Weizel A, Distler T, Schneidereit D, Friedrich O, Bräuer L, Paulsen F, Detsch R, Boccaccini A, Budday S, Seitz H. Complex mechanical behavior of human articular cartilage and hydrogels for cartilage repair. Acta Biomater 2020; 118:113-128. [PMID: 33080391 DOI: 10.1016/j.actbio.2020.10.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 12/29/2022]
Abstract
The mechanical behavior of cartilage tissue plays a crucial role in physiological mechanotransduction processes of chondrocytes and pathological changes like osteoarthritis. Therefore, intensive research activities focus on the identification of implant substitute materials that mechanically mimic the cartilage extracellular matrix. This, however, requires a thorough understanding of the complex mechanical behavior of both native cartilage and potential substitute materials to treat cartilage lesions. Here, we perform complex multi-modal mechanical analyses of human articular cartilage and two surrogate materials, commercially available ChondroFillerliquid, and oxidized alginate-gelatin (ADA-GEL) hydrogels. We show that all materials exhibit nonlinearity and compression-tension asymmetry. However, while hyaline cartilage yields higher stresses in tension than in compression, ChondroFillerliquid and ADA-GEL exhibit the opposite trend. These characteristics can be attributed to the materials' underlying microstructure: Both cartilage and ChondroFillerliquid contain fibrillar components, but the latter constitutes a bi-phasic structure, where the 60% nonfibrillar hydrogel proportion dominates the mechanical response. Of all materials, ChondroFillerliquid shows the most pronounced viscous effects. The present study provides important insights into the microstructure-property relationship of cartilage substitute materials, with vital implications for mechanically-driven material design in cartilage engineering. In addition, we provide a data set to create mechanical simulation models in the future.
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8
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Hahn MB, Smales GJ, Seitz H, Solomun T, Sturm H. Ectoine interaction with DNA: influence on ultraviolet radiation damage. Phys Chem Chem Phys 2020; 22:6984-6992. [PMID: 32188961 DOI: 10.1039/d0cp00092b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Ectoine is a small zwitterionic osmolyte and compatible solute, which does not interfere with cell metabolism even at molar concentrations. Plasmid DNA (pUC19) was irradiated with ultraviolet radiation (UV-C at 266 nm) under quasi physiological conditions (PBS) and in pure water in the presence and absence of ectoine (THP(B)) and hydroxyectoine (THP(A)). Different types of UV induced DNA damage were analysed: DNA single-strand breaks (SSBs), abasic sites and cyclobutane pyrimidine dimers (CPDs). A complex interplay between these factors was observed with respect to the nature and occurrence of DNA damage with 266 nm photons. In PBS, the cosolutes showed efficient protection against base damage, whilst in pure water, a dramatic shift from SSB damage to base damage was observed when cosolutes were added. To test whether these effects are caused by ectoine binding to DNA, further experiments were conducted: small-angle X-ray scattering (SAXS), surface-plasmon resonance (SPR) measurements and Raman spectroscopy. The results show, for the first time, a close interaction between ectoine and DNA. This is in stark contrast to the assumption made by preferential exclusion models, which are often used to interpret the behaviour of compatible solutes within cells and with biomolecules. It is tentatively proposed that the alterations of UV damage to DNA are attributed to ectoine influence on nucleobases through the direct interaction between ectoine and DNA.
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Affiliation(s)
- Marc Benjamin Hahn
- Freie Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany. and Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Glen J Smales
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Harald Seitz
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany and Fraunhofer Institute for Cell Therapy and Immunology, 14476 Potsdam, Germany
| | - Tihomir Solomun
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Heinz Sturm
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
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9
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Rekowska N, Teske M, Arbeiter D, Brietzke A, Konasch J, Riess A, Mau R, Eickner T, Seitz H, Grabow N. Biocompatibility and thermodynamic properties of PEGDA and two of its copolymer. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:1093-1096. [PMID: 31946084 DOI: 10.1109/embc.2019.8857503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
During the last years substantial effort was taken in order to provide an effective and safe pharmacotherapy that can be adjusted to the individual needs of patients. Stereolithography is a simple and accurate additive manufacturing technology. According to these characteristics, it may offer unique opportunities for the industrial fabrication of structured drug delivery systems (DDS), which can be tailored to individual needs. During the stereolithographic process photopolymerizable biomaterial is transformed, layer by layer, into the designed polymer DDS. Combined with inkjet printing in an innovative 3D building system it enables selective and precise incorporation of the drug depot into the basic body of the DDS. Poly(ethylene glycol) diacrylate (PEGDA), a hydrophilic and low-immunogenic compound, is a suitable material as drug depot in a photopolymerizable basic biomaterial for this purpose. By combination of PEGDA with other acrylates, the physical properties of the DDS can be adjusted towards the desired characteristics. Therefore, it should be possible to modify the drug release profile through the positioning of drug depots and the diffusion of the drug and adjust it for a wide range of applications. In this study we investigated basic biological and thermodynamic properties of conventionally photocured systems consisting of PEGDA and its coacrylates: 1,3-butanediol diacrylate and pentaerythritol triacrylate. Our preliminary outcomes demonstrate the hydrophilic character of the samples and the importance of a rinsing process. They also show that the addition of different amounts of co-monomers influence the glass transition temperature, which increases with increasing content of coacrylate. Therefore, PEGDA/comonomer composition can be used as a tool for the modification of drug release properties. Consequently, these materials may be regarded as interesting and promising components for DDS via novel additive manufacturing with the ability of highly controlled drug release.
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10
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Weizel A, Zimmermann J, Riess A, Kruger S, Bader R, Rienen UV, Seitz H. Numerical simulation of the electric field distribution in an electrical stimulation device for scaffolds settled with cartilaginous cells. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:6481-6484. [PMID: 31947326 DOI: 10.1109/embc.2019.8857760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Electrical stimulation is a promising approach to enhance cell viability and differentiation. We aim to develop a stimulation device for the investigation and realization of cartilaginous cell engineering. The stimulation setup is capable of applying well-defined electric fields to several scaffolds at the same time. The setup consists of a flat plate with multiple test tubes for the scaffolds. A flexible printed circuit board containing a separate pair of electrodes for each tube is fixed at the bottom of the plate. In this context, numerical simulation using Finite Element Method (FEM) is a valuable tool to gain a better understanding of the electric field distribution in such devices. The thin insulating layer of the flexible printed circuit board allows sufficient field strength to be achieved at moderate input voltages but presents challenges for modelling. In simulations, thin layers would usually require a fine discretization with many degrees of freedom (DOF). This leads to large models, which are expensive regarding memory and computation time. Based on the 'contact impedance' boundary condition available in COMSOL Multiphysics® 5.4, an alternative approach is proposed that can model thin layers in capacitively coupled setups. The resulting electric field distribution in the new stimulation setup is presented and discussed.
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11
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Wittenbrink N, Herrmann S, Blazquez-Navarro A, Bauer C, Lindberg E, Wolk K, Sabat R, Reinke P, Sawitzki B, Thomusch O, Hugo C, Babel N, Seitz H, Or-Guil M. A novel approach reveals that HLA class 1 single antigen bead-signatures provide a means of high-accuracy pre-transplant risk assessment of acute cellular rejection in renal transplantation. BMC Immunol 2019; 20:11. [PMID: 31029086 PMCID: PMC6486998 DOI: 10.1186/s12865-019-0291-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Acute cellular rejection (ACR) is associated with complications after kidney transplantation, such as graft dysfunction and graft loss. Early risk assessment is therefore critical for the improvement of transplantation outcomes. In this work, we retrospectively analyzed a pre-transplant HLA antigen bead assay data set that was acquired by the e:KID consortium as part of a systems medicine approach. RESULTS The data set included single antigen bead (SAB) reactivity profiles of 52 low-risk graft recipients (negative complement dependent cytotoxicity crossmatch, PRA < 30%) who showed detectable pre-transplant anti-HLA 1 antibodies. To assess whether the reactivity profiles provide a means for ACR risk assessment, we established a novel approach which differs from standard approaches in two aspects: the use of quantitative continuous data and the use of a multiparameter classification method. Remarkably, it achieved significant prediction of the 38 graft recipients who experienced ACR with a balanced accuracy of 82.7% (sensitivity = 76.5%, specificity = 88.9%). CONCLUSIONS The resultant classifier achieved one of the highest prediction accuracies in the literature for pre-transplant risk assessment of ACR. Importantly, it can facilitate risk assessment in non-sensitized patients who lack donor-specific antibodies. As the classifier is based on continuous data and includes weak signals, our results emphasize that not only strong but also weak binding interactions of antibodies and HLA 1 antigens contain predictive information. TRIAL REGISTRATION ClinicalTrials.gov NCT00724022 . Retrospectively registered July 2008.
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Affiliation(s)
- Nicole Wittenbrink
- Systems Immunology Lab, Department of Biology, Humboldt University Berlin, Berlin, Germany
| | - Sabrina Herrmann
- Fraunhofer Institute for Cell Therapy and Immunology, Bioanalytics und Bioprocesses, Potsdam, Germany
| | - Arturo Blazquez-Navarro
- Systems Immunology Lab, Department of Biology, Humboldt University Berlin, Berlin, Germany
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
| | | | | | - Kerstin Wolk
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
- Psoriasis Research and Treatment Center, Institute of Medical Immunology, Department of Dermatology and Allergy, Charité University Medicine Berlin, Berlin, Germany
| | - Robert Sabat
- Psoriasis Research and Treatment Center, Institute of Medical Immunology, Department of Dermatology and Allergy, Charité University Medicine Berlin, Berlin, Germany
- Interdisciplinary Group of Molecular Immunopathology, Institute of Medical Immunology, Department of Dermatology and Allergy, Charité University Medicine Berlin, Berlin, Germany
| | - Petra Reinke
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
- Department of Nephrology and Internal Intensive Care, Charité University Medicine Berlin, Campus Virchow Clinic, Berlin, Germany
- Berlin Center for Advanced Therapies (BeCAT), Charité University Medicine Berlin, Campus Virchow Clinic, Berlin, Germany
| | - Birgit Sawitzki
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
- Molecular Immune Modulation, Institute for Medical Immunology, Charité University Medicine Berlin, Campus Virchow Clinic, Berlin, Germany
| | - Oliver Thomusch
- Klinik für Allgemein- und Viszeralchirurgie, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Christian Hugo
- University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Nina Babel
- Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Berlin, Germany
- Medical Clinic I, Marien Hospital Herne, Ruhr University Bochum, Herne, Germany
| | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology, Bioanalytics und Bioprocesses, Potsdam, Germany
| | - Michal Or-Guil
- Systems Immunology Lab, Department of Biology, Humboldt University Berlin, Berlin, Germany
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Hahn MB, Meyer S, Schröter MA, Seitz H, Kunte HJ, Solomun T, Sturm H. Direct electron irradiation of DNA in a fully aqueous environment. Damage determination in combination with Monte Carlo simulations. Phys Chem Chem Phys 2018; 19:1798-1805. [PMID: 28059422 DOI: 10.1039/c6cp07707b] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane. The corresponding Monte Carlo simulations suggest that the kinetic energy spectrum of the electrons throughout the water is dominated by low energy electrons (<100 eV). The DNA radiation damage, single-strand breaks (SSBs) and double-strand breaks (DSBs), was determined by gel electrophoresis. The median lethal dose of D1/2 = 1.7 ± 0.3 Gy was found to be much smaller as compared to partially or fully hydrated DNA irradiated under vacuum conditions. The ratio of the DSBs to SSBs was found to be 1 : 12 as compared to 1 : 88 found for hydrated DNA. Our method enables quantitative measurements of radiation damage to biomolecules (DNA, proteins) in solutions under varying conditions (pH, salinity, co-solutes) for an electron energy range which is difficult to probe by standard methods.
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Affiliation(s)
- Marc Benjamin Hahn
- Free University Berlin, Department of Physics, D-14195 Berlin, Germany. and Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Susann Meyer
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany. and University of Potsdam, Institute of Biochemistry and Biology, D-14476 Potsdam, Germany
| | | | - Harald Seitz
- Fraunhofer-Institut für Zelltherapie und Immunologie, Institutsteil Bioanalytik und Bioprozesse, D-14476 Potsdam, Germany
| | - Hans-Jörg Kunte
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Tihomir Solomun
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Heinz Sturm
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany. and Technical University Berlin, D-10587 Berlin, Germany
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15
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Schumacher S, Seitz H. A novel immunoassay for quantitative drug abuse screening in serum. J Immunol Methods 2016; 436:34-40. [DOI: 10.1016/j.jim.2016.06.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 06/21/2016] [Accepted: 06/21/2016] [Indexed: 01/10/2023]
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16
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Schumacher S, Seitz H. Quality control of antibodies for assay development. N Biotechnol 2016; 33:544-50. [PMID: 26873787 DOI: 10.1016/j.nbt.2016.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 01/12/2016] [Accepted: 02/03/2016] [Indexed: 01/19/2023]
Abstract
Antibodies are used as powerful tools in basic research, for example, in biomarker identification, and in various forms for diagnostics, for example, identification of allergies or autoimmune diseases. Due to their robustness and ease of handling, immunoassays are favourite methods for investigation of various biological or medical questions. Nevertheless in many cases, additional analyses such as mass spectrometry are used to validate or confirm the results of immunoassays. To minimize the workload and to increase confidence in immunoassays, there are urgent needs for antibodies which are both highly specific and well validated. Unfortunately many commercially available antibodies are neither well characterized nor fully tested for cross-reactivities. Adequate quality control and validation of an antibody is time-consuming and can be frustrating. Such validation needs to be performed for every assay/application. However, where an antibody validation is successful, a highly specific and stable reagent will be on hand. This article describes the validation processes of antibodies, including some often neglected factors, as well as unspecific binding to other sample compounds in a multiparameter diagnostic assay. The validation consists of different immunological methods, with important assay controls, and is performed in relation to the development of a diagnostic test.
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Affiliation(s)
- Sarah Schumacher
- Fraunhofer Institute for Cell Therapy and Immunology - Bioanalytics und Bioprocesses, Am Mühlenberg 13, 14476 Potsdam, Germany; Humboldt University Berlin, Department of Biology, Invalidenstr. 110, 10115 Berlin, Germany
| | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology - Bioanalytics und Bioprocesses, Am Mühlenberg 13, 14476 Potsdam, Germany.
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Hahn MB, Solomun T, Wellhausen R, Hermann S, Seitz H, Meyer S, Kunte HJ, Zeman J, Uhlig F, Smiatek J, Sturm H. Influence of the Compatible Solute Ectoine on the Local Water Structure: Implications for the Binding of the Protein G5P to DNA. J Phys Chem B 2015; 119:15212-20. [PMID: 26555929 DOI: 10.1021/acs.jpcb.5b09506] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Microorganisms accumulate molar concentrations of compatible solutes like ectoine to prevent proteins from denaturation. Direct structural or spectroscopic information on the mechanism and about the hydration shell around ectoine are scarce. We combined surface plasmon resonance (SPR), confocal Raman spectroscopy, molecular dynamics simulations, and density functional theory (DFT) calculations to study the local hydration shell around ectoine and its influence on the binding of a gene-5-protein (G5P) to a single-stranded DNA (dT25). Due to the very high hygroscopicity of ectoine, it was possible to analyze the highly stable hydration shell by confocal Raman spectroscopy. Corresponding molecular dynamics simulation results revealed a significant change of the water dielectric constant in the presence of a high molar ectoine concentration as compared to pure water. The SPR data showed that the amount of protein bound to DNA decreases in the presence of ectoine, and hence, the protein-DNA dissociation constant increases in a concentration-dependent manner. Concomitantly, the Raman spectra in terms of the amide I region revealed large changes in the protein secondary structure. Our results indicate that ectoine strongly affects the molecular recognition between the protein and the oligonucleotide, which has important consequences for osmotic regulation mechanisms.
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Affiliation(s)
- Marc Benjamin Hahn
- Federal Institute for Materials Research and Testing , D-12205 Berlin, Germany.,Department of Physics, Free University Berlin , D-14195 Berlin, Germany
| | - Tihomir Solomun
- Federal Institute for Materials Research and Testing , D-12205 Berlin, Germany
| | - Robert Wellhausen
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytic and Bioprocesses , D-14476 Potsdam-Golm, Germany
| | - Sabrina Hermann
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytic and Bioprocesses , D-14476 Potsdam-Golm, Germany
| | - Harald Seitz
- Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytic and Bioprocesses , D-14476 Potsdam-Golm, Germany
| | - Susann Meyer
- Federal Institute for Materials Research and Testing , D-12205 Berlin, Germany.,Institute of Biochemistry and Biology, University of Potsdam , D-14476 Potsdam, Germany
| | - Hans-Jörg Kunte
- Federal Institute for Materials Research and Testing , D-12205 Berlin, Germany
| | - Johannes Zeman
- Institute for Computational Physics, University of Stuttgart , D-70569 Stuttgart, Germany
| | - Frank Uhlig
- Institute for Computational Physics, University of Stuttgart , D-70569 Stuttgart, Germany
| | - Jens Smiatek
- Institute for Computational Physics, University of Stuttgart , D-70569 Stuttgart, Germany
| | - Heinz Sturm
- Federal Institute for Materials Research and Testing , D-12205 Berlin, Germany.,Technical University Berlin , D-10587 Berlin, Germany
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Seitz H, Mueller S, Rausch V. SY05ALCOHOL AND CANCERSY05-1CARCINOGENIC ETHENO DNA ADDUCTS GENERATED DURING INFLAMMATION AND CYP2E1 INDUCTION IN VARIOUS TISSUES FOLLOWING ALCOHOL CONSUMPTION. Alcohol Alcohol 2015. [DOI: 10.1093/alcalc/agv076.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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19
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Schumacher S, Muekusch S, Seitz H. Up-to-Date Applications of Microarrays and Their Way to Commercialization. Microarrays (Basel) 2015; 4:196-213. [PMID: 27600220 PMCID: PMC4996390 DOI: 10.3390/microarrays4020196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/01/2015] [Accepted: 04/14/2015] [Indexed: 12/12/2022]
Abstract
This review addresses up-to-date applications of Protein Microarrays. Protein Microarrays play a significant role in basic research as well as in clinical applications and are applicable in a lot of fields, e.g., DNA, proteins and small molecules. Additionally they are on the way to enter clinics in routine diagnostics. Protein Microarrays can be powerful tools to improve healthcare. An overview of basic characteristics to mediate essential knowledge of this technique is given. To reach this goal, some challenges still have to be addressed. A few applications of Protein Microarrays in a medical context are shown. Finally, an outlook, where the potential of Protein Microarrays is depicted and speculations how the future of Protein Microarrays will look like are made.
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Affiliation(s)
- Sarah Schumacher
- Branch Bioanalytics and Bioprocesses, Fraunhofer Institute for Cell Therapy and Immunology, Am Muehlenberg 13, 14476 Potsdam, Germany.
| | - Sandra Muekusch
- Branch Bioanalytics and Bioprocesses, Fraunhofer Institute for Cell Therapy and Immunology, Am Muehlenberg 13, 14476 Potsdam, Germany.
| | - Harald Seitz
- Branch Bioanalytics and Bioprocesses, Fraunhofer Institute for Cell Therapy and Immunology, Am Muehlenberg 13, 14476 Potsdam, Germany.
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20
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Schumacher S, Victor T, Seitz H. Detection of antibiotic resistances of Mycobacterium tuberculosis on DNA microarrays. Int J Infect Dis 2014. [DOI: 10.1016/j.ijid.2014.03.630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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21
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Pratsch K, Wellhausen R, Seitz H. Advances in the quantification of protein microarrays. Curr Opin Chem Biol 2014; 18:16-20. [DOI: 10.1016/j.cbpa.2013.10.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 10/18/2013] [Accepted: 10/22/2013] [Indexed: 10/26/2022]
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22
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Fiedler S, Irsig R, Tiggesbäumker J, Schuster C, Merschjann C, Rothe N, Lochbrunner S, Vehse M, Seitz H, Klinkenberg ED, Meiwes-Broer KH. Machining of Biocompatible Ceramics with Femtosecond Laser Pulses. BIOMED ENG-BIOMED TE 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-C/bmt-2013-4093/bmt-2013-4093.xml. [PMID: 24042670 DOI: 10.1515/bmt-2013-4093] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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23
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Cornelsen M, Petersen S, Dietsch K, Rudolph A, Schmitz K, Sternberg K, Seitz H. Infiltration of 3D printed tricalciumphosphate scaffolds with biodegradable polymers and biomolecules for local drug delivery. ACTA ACUST UNITED AC 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-C/bmt-2013-4090/bmt-2013-4090.xml. [PMID: 24042685 DOI: 10.1515/bmt-2013-4090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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24
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Tsukamoto H, Stickel F, Seitz H, Rao R, Gangwar R, Samak G, Mir H, Chaudhry K, Manda B, Nagy L, Sood A, Nagy L, Chiang D, Roychowdhury S. S13 * MULTIPLE HITS IN THE PATHOGENESIS OF ALCOHOLIC LIVER DISEASE. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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25
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Szabo G, Dooley S, Mueller S, Seitz H, Bataller R, Sanyal A, Caravati C. S04 * ALCOHOLIC HEPATITIS ESBRA & NIAAA JOINT SYMPOSIUM. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Schuckit M, O'Brien C, Seitz H, De Witte P. PL1 * FOUR DECADES OF RESEARCH ON THE LEVEL OF RESPONSE TO ALCOHOL AS A RISK FACTOR FOR ALCOHOLISM: FROM IDEA TO PREVENTION. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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27
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Wurst F, Allen J, Thon N, Litten R, Dom G, Seitz H, Bobes J, Preuss U. S22 * LIVER TRANSPLANTATION: A EUROPEAN PERSPECTIVE SYMPOSIUM OF THE EUROPEAN FEDERATION OF ADDICTION SOCIETES (EUFAS) II. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Wawrzynowicz-Syczewska M, Laurans L, Jurczyk K, Lachtara M, Kornak D, Dooley S, Hofmann S, Rakoczy P, Breitkopf-Heinlein K, Meyer C, Stickel F, Patsenker E, Buch S, Hampe J, Datz C, Seitz H, Trabut JB, Gagni C, Patel V, Mueller S, Rausch V, Peccerella T, Seitz H, Stickel F, Yagmur E, Herzig S, Longerich T, Mueller S, Yagmur E, Seitz H, Stickel F, Longerich T, Bantel H, Houchi H, Nguyen-Khac E, Dreher ML, Naassila M, Borodinsky A, Razvodovsky Y. ALCOHOL LIVER DISEASE. Alcohol Alcohol 2013. [DOI: 10.1093/alcalc/agt116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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29
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Wojnar M, Klimkiewicz A, Seitz H. 14th Congress of the European Society for Biomedical Research on Alcoholism (ESBRA) September 8-11, 2013 Warsaw, Poland. Alcohol Alcohol 2013; 48 Suppl 1:i1-63. [DOI: 10.1093/alcalc/agt120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
Small regulatory RNAs (microRNAs, siRNAs, and piRNAs) exhibit several unique features that clearly distinguish them from other known gene regulators. Their genomic organization, mode of action, and proposed biological functions raise specific questions. In this review, we focus on the quantitative aspect of small regulatory RNA biology. The original nature of these small RNAs accelerated the development of novel detection techniques and improved statistical methods and promoted new concepts that may unexpectedly generalize to other gene regulators. Quantification of natural phenomena is at the core of scientific practice, and the unique challenges raised by small regulatory RNAs have prompted many creative innovations by the scientific community.
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Affiliation(s)
- A M Sergeeva
- IGH du CNRS UPR 1142, 34396 Montpellier, France.
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Schuster C, Merschjann C, Rothe N, Fiedler S, Irsig R, Meiwes-Broer KH, Vehse M, Seitz H, Senz V, Sternberg K, Lochbrunner S. Machining of Biocompatible Polymers with Shaped Femtosecond Laser Pulses. BIOMED ENG-BIOMED TE 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-C/bmt-2013-4085/bmt-2013-4085.xml. [DOI: 10.1515/bmt-2013-4085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Drescher P, Wilmes B, Dangers M, Rübenhagen R, Seitz H. Comparison of Elisa Sensitivity Relating to Manual and Low-Pressure Loading of the Fluidic Test Device. BIOMED ENG-BIOMED TE 2013; 58 Suppl 1:/j/bmte.2013.58.issue-s1-F/bmt-2013-4152/bmt-2013-4152.xml. [DOI: 10.1515/bmt-2013-4152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Schütz F, Maleika A, Poeschl J, Domschke C, Seitz H, Beuter-Winkler P, Sohn C. Partnerships between Medical Centres and General Hospitals Providing Normal Care Standards in Gynaecology and Obstetrics in Germany. Geburtshilfe Frauenheilkd 2012; 72:922-926. [PMID: 25308978 PMCID: PMC4168358 DOI: 10.1055/s-0032-1327853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/03/2012] [Accepted: 09/03/2012] [Indexed: 10/27/2022] Open
Abstract
Hospital managers and the heads of medical departments are nowadays being faced with ever increasing demands. It is becoming difficult for some small hospitals to find highly experienced or even experienced medical staff, to provide specific health-care services at break-even prices and to maintain their position in competition with other hospitals. On the other hand, large hospitals are facing enormous pressure in the investment and costs fields. Cooperation could provide a solution for these problems. For an optimal strategic exploitation of the hospitals, their direction could be placed in the hands of a joint medical director. However, the directorship of two hospitals is associated both with opportunities and with risks. The present article illustrates the widely differing aspects of the cooperation between a medical centre and a general hospital providing standard care from both a theoretical point of view and on the basis of practical experience with an actual cooperation of this type in Heidelberg.
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Affiliation(s)
- F. Schütz
- Frauenklinik, Universitätsklinikum Heidelberg, Heidelberg
| | - A. Maleika
- Gynäkologie & Geburtshilfe, Krankenhaus Salem, Heidelberg
| | - J. Poeschl
- Universitätskinderklinik, Universitätsklinikum Heidelberg, Heidelberg
| | - C. Domschke
- Universitätsfrauenklinik, Universitätsklinikum Heidelberg, Heidelberg
| | - H. Seitz
- Innere Medizin, Krankenhaus Salem, Heidelberg
| | | | - C. Sohn
- Universitätsfrauenklinik, Universitätsklinikum Heidelberg, Heidelberg
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Köhler K, Seitz H. Validation processes of protein biomarkers in serum--a cross platform comparison. Sensors (Basel) 2012; 12:12710-28. [PMID: 23112739 PMCID: PMC3478866 DOI: 10.3390/s120912710] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 09/06/2012] [Accepted: 09/10/2012] [Indexed: 12/14/2022]
Abstract
Due to insufficient biomarker validation and poor performances in diagnostic assays, the candidate biomarker verification process has to be improved. Multi-analyte immunoassays are the tool of choice for the identification and detailed validation of protein biomarkers in serum. The process of identification and validation of serum biomarkers, as well as their implementation in diagnostic routine requires an application of independent immunoassay platforms with the possibility of high-throughput. This review will focus on three main multi-analyte immunoassay platforms: planar microarrays, multiplex bead systems and, array-based surface plasmon resonance (SPR) chips. Recent developments of each platform will be discussed for application in clinical proteomics, principles, detection methods, and performance strength. The requirements for specific surface functionalization of assay platforms are continuously increasing. The reasons for this increase is the demand for highly sensitive assays, as well as the reduction of non-specific adsorption from complex samples, and with it high signal-to-noise-ratios. To achieve this, different support materials were adapted to the immobilized biomarker/ligand, allowing a high binding capacity and immobilization efficiency. In the case of immunoassays, the immobilized ligands are proteins, antibodies or peptides, which exhibit a diversity of chemical properties (acidic/alkaline; hydrophobic/hydrophilic; secondary or tertiary structure/linear). Consequently it is more challenging to develop immobilization strategies necessary to ensure a homogenous covered surface and reliable assay in comparison to DNA immobilization. New developments concerning material support for each platform are discussed especially with regard to increase the immobilization efficiency and reducing the non-specific adsorption from complex samples like serum and cell lysates.
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Affiliation(s)
- Katja Köhler
- Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam-Golm, Am Mühlenberg 13, 14476 Potsdam-Golm, Germany; E-Mail:
| | - Harald Seitz
- Fraunhofer Institute for Biomedical Engineering IBMT, Branch Potsdam-Golm, Am Mühlenberg 13, 14476 Potsdam-Golm, Germany; E-Mail:
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Becker S, Bolte H, Schünemann K, Seitz H, Bara J, Beck-Broichsitter B, Russo P, Wiltfang J, Warnke P. Endocultivation: the influence of delayed vs. simultaneous application of BMP-2 onto individually formed hydroxyapatite matrices for heterotopic bone induction. Int J Oral Maxillofac Surg 2012; 41:1153-60. [DOI: 10.1016/j.ijom.2012.03.031] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 01/16/2012] [Accepted: 03/20/2012] [Indexed: 11/25/2022]
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Abstract
In most bacteria, the timing and synchrony of initiation of chromosomal replication are determined by the binding of the AAA+ protein DnaA to a set of high- and low-affinity sites found within the origin of chromosomal replication (oriC). Despite the large amount of information on the role and regulation of DnaA, the actual structure of the DnaA–oriC complex and the mechanism by which it primes the origin for the initiation of replication remain unclear. In this study, we have performed magnetic tweezers experiments to investigate the structural properties of the DnaA–oriC complex. We show that the DnaA-ATP–oriC complex adopts a right-handed helical conformation involving a variable amount of DNA and protein whose features fit qualitatively as well as quantitatively with an existing model based on the crystal structure of a truncated DnaA tetramer obtained in the absence of DNA. We also investigate the topological effect of oriC’s DNA unwinding element.
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Affiliation(s)
- Sylvain Zorman
- Institut Jacques Monod, CN RS UMR 7592, Univ Paris Diderot, Sorbonne Paris Cité, F-75205 Paris, France
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Vehse M, Löbler M, Schmitz KP, Seitz H. Laser induced surface structure on stainless steel influences cell viability. BIOMED ENG-BIOMED TE 2012. [DOI: 10.1515/bmt-2012-4007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Vehse M, Gieseke M, Fiedler S, Petersen S, Irsig R, Senz V, Löbler M, Hustedt M, Kaierle S, Haferkamp H, Sternberg K, Schmitz KP, Lochbrunner S, Meiwes-Broer KH, Seitz H. Loading method for discrete drug depots on implant surfaces. BIOMED ENG-BIOMED TE 2012. [DOI: 10.1515/bmt-2012-4006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Schuster C, Rothe N, Svanidze AV, Fiedler S, Irsig R, Tiggesbäumker J, Senz V, Vehse M, Seitz H, Lochbrunner S. Material processing with shaped femtosecond laser pulses. BIOMED ENG-BIOMED TE 2012. [DOI: 10.1515/bmt-2012-4037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Egkher A, Schlenz I, Seitz H. Traumatic epiphysiolysis of the proximal femur. Acta Chir Orthop Traumatol Cech 2012; 79:114-118. [PMID: 22538100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE OF THE STUDY Several former studies show the treatment of slipped epiphysis of the femoral head (SEFH). Its reason is rather unknown. On the other hand the rare traumatic SEFH takes place due to a real accident. According to the literature these injuries are treated like chronic SEFHs. The aim of this study is to show the differences in pathology and treatment of an acute traumatic SEFH in relationship to the chronic SEFH. PATIENTS AND METHODS In 8 patients dislocated traumatic SEFHs were reduced anatomically and stabilized by the means of 3 to 4 Kirschner- (K-) wires or two cancellous screws. Each patient got a plaster-cast fixation for about 6 weeks of the ipsilateral hip and leg and was mobilized with two crutches and partial weight bearing for 12 weeks. The implants were removed 24 weeks after surgery. Four patients with not dislocated SEFHs were immobilized or mobilized with two crutches without weight bearing according to their pain sensation. The final examination of both groups took place 2 Vz to 15 years after the initial treatment. RESULTS Four patients primarily under 10 years of age showed no or minimal radiological signs of a dislocated femoral head and were without any further inconvenience--the suspected SEFHs revealed as hip contusions. 8 children aged 10 years or older at the time of trauma were treated by closed reduction and internal fixation. Complications occurred in three cases--one necrosis of the femoral head because of a perforating K-wire, one subtrochanteric femur fracture after implant removal of a prophylactically stabilized contralateral femoral head and one minimally dislocated femoral head after postoperative too early full weight bearing. DISCUSSION The traumatic SEFH is very different to the chronic one regarding the pathology and acute treatment. Technical challenges must be solved. Unilateral K-wiring or screwing for 24 weeks and reduced weight bearing for the first 12 weeks after surgery is a sufficient way of treatment of the traumatic SEFH. CONCLUSIONS In the case of a traumatic SEFH it needs to be reduced anatomically and stabilized by surgical means in the acute phase. A prophylactic stabilization of the opposite intact side is usually not required.
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Affiliation(s)
- A Egkher
- Department of Trauma Surgery, Medical University of Vienna, Vienna, Austria
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Ganzleben I, Seitz H, Mueller S, Millonig G, Helminen A, Salaspuro M, Vakevainen S, Breitkopf-Heinlein K, Gaitantzi H, Meyer C, Li Q, Dzieran J, Millonig G, Mueller S, Bantel H, Bergheim I, Dooley S, Helminen A, Salaspuro M, Vakevainen S, Blecha L, Benyamina A, Domart M, Lemoine A, Debuire B, Saffroy R, Reynaud M. S22 * YOUNG RESEARCHER SYMPOSIUM II: PATHOGENETIC MECHANISMS OF ALCOHOLIC ASSOCIATED ORGAN INJURY * S22.1 * IRON METABOLISM IN PATIENTS WITH ALD. Alcohol Alcohol 2011. [DOI: 10.1093/alcalc/agr112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
Sensitive detection assays are a prerequisite for the analysis of small amounts of samples derived from biological material. There is a great demand for highly sensitive and robust detection techniques to analyze biomolecules. The combination of catalytic active DNA (DNAzyme) with a peroxidase activity with rolling circle amplification (RCA) is a promising alternative to common detection systems. The rolling circle amplification leads to a product with tandemly linked copies of DNAzymes. The continuous signal generation of the amplified DNAzymes results in an increased sensitivity. The combination of two amplification reactions, namely RCA and DNAzymes, results in increased signal intensity by a factor of 10(6). With this approach the labeling of samples can be avoided. The advantage of the introduced assay is the usage of nucleic acids as biosensors for the detection of biomolecules. Coupling of the analyte molecule to the detection molecules allows the direct detection of the analyte molecule. The described label-free hotpot assay has a broad potential field of applications. The hotpot assay can be adapted to detect and analyze RNA, DNA and proteins down to femtomolar concentrations in a miniaturized platform with a total reaction solution of 50 nl. The applicability of the assay for diagnostics and research will be shown with a focus on high throughput systems using a nano-well platform.
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Affiliation(s)
- Daniela M Köster
- Max Planck Institute for Molecular Genetics, Vertebrate Genomics, Ihnestraße 63-73, 14195 Berlin, Germany
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Schwibbert K, Marin-Sanguino A, Bagyan I, Heidrich G, Lentzen G, Seitz H, Rampp M, Schuster SC, Klenk HP, Pfeiffer F, Oesterhelt D, Kunte HJ. A blueprint of ectoine metabolism from the genome of the industrial producer Halomonas elongata DSM 2581 T. Environ Microbiol 2010; 13:1973-94. [PMID: 20849449 PMCID: PMC3187862 DOI: 10.1111/j.1462-2920.2010.02336.x] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The halophilic γ-proteobacterium Halomonas elongata DSM 2581T thrives at high salinity by synthesizing and accumulating the compatible solute ectoine. Ectoine levels are highly regulated according to external salt levels but the overall picture of its metabolism and control is not well understood. Apart from its critical role in cell adaptation to halophilic environments, ectoine can be used as a stabilizer for enzymes and as a cell protectant in skin and health care applications and is thus produced annually on a scale of tons in an industrial process using H. elongata as producer strain. This paper presents the complete genome sequence of H. elongata (4 061 296 bp) and includes experiments and analysis identifying and characterizing the entire ectoine metabolism, including a newly discovered pathway for ectoine degradation and its cyclic connection to ectoine synthesis. The degradation of ectoine (doe) proceeds via hydrolysis of ectoine (DoeA) to Nα-acetyl-l-2,4-diaminobutyric acid, followed by deacetylation to diaminobutyric acid (DoeB). In H. elongata, diaminobutyric acid can either flow off to aspartate or re-enter the ectoine synthesis pathway, forming a cycle of ectoine synthesis and degradation. Genome comparison revealed that the ectoine degradation pathway exists predominantly in non-halophilic bacteria unable to synthesize ectoine. Based on the resulting genetic and biochemical data, a metabolic flux model of ectoine metabolism was derived that can be used to understand the way H. elongata survives under varying salt stresses and that provides a basis for a model-driven improvement of industrial ectoine production.
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Affiliation(s)
- Karin Schwibbert
- Materials and Environment Division, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
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Abstract
Single-stranded DNA oligonucleotides (33-mers) containing different numbers of guanines (n=1-4) were tethered to a gold surface and exposed to 1 eV electrons. The electrons induced DNA damage, which was analyzed with fluorescence and infrared spectroscopy methods. The damage was identified as strand breaks and found to correlate linearly with the number of guanines in the sequence. This sequence dependence indicates that the electron capture by the DNA bases plays an important role in the damage reaction mechanism.
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Affiliation(s)
- T Solomun
- Institute of Chemistry and Biochemistry, Free University Berlin, Takustrasse 3, D-14195 Berlin, Germany.
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Millonig G, Giesel F, Reimann F, Topalidis T, Seitz H, Mueller S. Gastrointestinal Stromal Tumor in a Patient with Undiagnosed Neurofibromatosis Type I: an Uncommon Cause of Extrahepatic Cholestasis. Z Gastroenterol 2009; 48:479-81. [DOI: 10.1055/s-0028-1109604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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