1
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Drakhlis L, Biswanath S, Farr CM, Lupanow V, Teske J, Ritzenhoff K, Franke A, Manstein F, Bolesani E, Kempf H, Liebscher S, Schenke-Layland K, Hegermann J, Nolte L, Meyer H, de la Roche J, Thiemann S, Wahl-Schott C, Martin U, Zweigerdt R. Human heart-forming organoids recapitulate early heart and foregut development. Nat Biotechnol 2021; 39:737-746. [PMID: 33558697 PMCID: PMC8192303 DOI: 10.1038/s41587-021-00815-9] [Citation(s) in RCA: 143] [Impact Index Per Article: 47.7] [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] [Received: 06/18/2019] [Accepted: 12/30/2020] [Indexed: 12/13/2022]
Abstract
Organoid models of early tissue development have been produced for the intestine, brain, kidney and other organs, but similar approaches for the heart have been lacking. Here we generate complex, highly structured, three-dimensional heart-forming organoids (HFOs) by embedding human pluripotent stem cell aggregates in Matrigel followed by directed cardiac differentiation via biphasic WNT pathway modulation with small molecules. HFOs are composed of a myocardial layer lined by endocardial-like cells and surrounded by septum-transversum-like anlagen; they further contain spatially and molecularly distinct anterior versus posterior foregut endoderm tissues and a vascular network. The architecture of HFOs closely resembles aspects of early native heart anlagen before heart tube formation, which is known to require an interplay with foregut endoderm development. We apply HFOs to study genetic defects in vitro by demonstrating that NKX2.5-knockout HFOs show a phenotype reminiscent of cardiac malformations previously observed in transgenic mice. Heart-forming organoids model early cardiac development.
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Affiliation(s)
- Lika Drakhlis
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany.
| | - Santoshi Biswanath
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Clara-Milena Farr
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Victoria Lupanow
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Jana Teske
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Katharina Ritzenhoff
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Annika Franke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Felix Manstein
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Emiliano Bolesani
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Henning Kempf
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany.,Stem Cell Discovery, Novo Nordisk A/S, Måløv, Denmark
| | - Simone Liebscher
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Katja Schenke-Layland
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany.,The Natural and Medical Sciences Institute (NMI) at the University of Tübingen, Reutlingen, Germany.,Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.,Cluster of Excellence iFIT (EXC 2180) 'Image-Guided and Functionally Instructed Tumor Therapies', Eberhard Karls University Tübingen, Tübingen, Germany
| | - Jan Hegermann
- Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany.,Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Lena Nolte
- Industrial and Biomedical Optics Department, Laser Zentrum Hannover, Hannover, Germany
| | - Heiko Meyer
- Industrial and Biomedical Optics Department, Laser Zentrum Hannover, Hannover, Germany
| | - Jeanne de la Roche
- Institute for Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Stefan Thiemann
- Institute for Neurophysiology, Hannover Medical School, Hannover, Germany
| | | | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover, Germany
| | - Robert Zweigerdt
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG), REBIRTH-Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany.
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2
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Weber N, Kowalski K, Holler T, Radocaj A, Fischer M, Thiemann S, de la Roche J, Schwanke K, Piep B, Peschel N, Krumm U, Lingk A, Wendland M, Greten S, Schmitto JD, Ismail I, Warnecke G, Zywietz U, Chichkov B, Meißner J, Haverich A, Martin U, Brenner B, Zweigerdt R, Kraft T. Advanced Single-Cell Mapping Reveals that in hESC Cardiomyocytes Contraction Kinetics and Action Potential Are Independent of Myosin Isoform. Stem Cell Reports 2020; 14:788-802. [PMID: 32302556 PMCID: PMC7220955 DOI: 10.1016/j.stemcr.2020.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/12/2020] [Accepted: 03/17/2020] [Indexed: 01/14/2023] Open
Abstract
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow β-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus β-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus β-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated.
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Affiliation(s)
- Natalie Weber
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany.
| | - Kathrin Kowalski
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Tim Holler
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Ante Radocaj
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Martin Fischer
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Stefan Thiemann
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Jeanne de la Roche
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Kristin Schwanke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Birgit Piep
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Neele Peschel
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Uwe Krumm
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Alexander Lingk
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Meike Wendland
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Stephan Greten
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Jan Dieter Schmitto
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Issam Ismail
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Gregor Warnecke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Urs Zywietz
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Boris Chichkov
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Joachim Meißner
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Axel Haverich
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Bernhard Brenner
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Robert Zweigerdt
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Theresia Kraft
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
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3
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Gorinski N, Wojciechowski D, Guseva D, Abdel Galil D, Mueller FE, Wirth A, Thiemann S, Zeug A, Schmidt S, Zareba-Kozioł M, Wlodarczyk J, Skryabin BV, Glage S, Fischer M, Al-Samir S, Kerkenberg N, Hohoff C, Zhang W, Endeward V, Ponimaskin E. DHHC7-mediated palmitoylation of the accessory protein barttin critically regulates the functions of ClC-K chloride channels. J Biol Chem 2020; 295:5970-5983. [PMID: 32184353 DOI: 10.1074/jbc.ra119.011049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 09/11/2019] [Revised: 03/13/2020] [Indexed: 12/21/2022] Open
Abstract
Barttin is the accessory subunit of the human ClC-K chloride channels, which are expressed in both the kidney and inner ear. Barttin promotes trafficking of the complex it forms with ClC-K to the plasma membrane and is involved in activating this channel. Barttin undergoes post-translational palmitoylation that is essential for its functions, but the enzyme(s) catalyzing this post-translational modification is unknown. Here, we identified zinc finger DHHC-type containing 7 (DHHC7) protein as an important barttin palmitoyl acyltransferase, whose depletion affected barttin palmitoylation and ClC-K-barttin channel activation. We investigated the functional role of barttin palmitoylation in vivo in Zdhhc7 -/- mice. Although palmitoylation of barttin in kidneys of Zdhhc7 -/- animals was significantly decreased, it did not pathologically alter kidney structure and functions under physiological conditions. However, when Zdhhc7 -/- mice were fed a low-salt diet, they developed hyponatremia and mild metabolic alkalosis, symptoms characteristic of human Bartter syndrome (BS) type IV. Of note, we also observed decreased palmitoylation of the disease-causing R8L barttin variant associated with human BS type IV. Our results indicate that dysregulated DHHC7-mediated barttin palmitoylation appears to play an important role in chloride channel dysfunction in certain BS variants, suggesting that targeting DHHC7 activity may offer a potential therapeutic strategy for reducing hypertension.
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Affiliation(s)
- Nataliya Gorinski
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | | | - Daria Guseva
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Dalia Abdel Galil
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Franziska E Mueller
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Alexander Wirth
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Stefan Thiemann
- Institute for Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Andre Zeug
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Silke Schmidt
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Monika Zareba-Kozioł
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Jakub Wlodarczyk
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Boris V Skryabin
- Department of Medicine, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Münster, 48149 Münster, Germany
| | - Silke Glage
- Institute for Laboratory Animal Science, Hannover Medical School, 30625 Hannover, Germany
| | - Martin Fischer
- Institute for Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Samer Al-Samir
- Institute of Vegetative Physiology, Hannover Medical School, 30625 Hannover, Germany
| | - Nicole Kerkenberg
- Department of Psychiatry and Psychotherapy, Laboratory for Molecular Psychiatry, University of Münster, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
| | - Christa Hohoff
- Department of Psychiatry and Psychotherapy, Laboratory for Molecular Psychiatry, University of Münster, 48149 Münster, Germany
| | - Weiqi Zhang
- Department of Psychiatry and Psychotherapy, Laboratory for Molecular Psychiatry, University of Münster, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany
| | - Volker Endeward
- Institute of Vegetative Physiology, Hannover Medical School, 30625 Hannover, Germany
| | - Evgeni Ponimaskin
- Department of Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany.
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4
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Weber N, Holler T, Meißner J, Montag J, Fischer M, de la Roche J, Thiemann S, Peschel N, Kathrin Mayer A, Schwanke K, Piep B, Martin U, Zweigerdt R, Kraft T. Hypertrophic Cardiomyopathy: Prolonged Twitch, Calcium Transients and Action Potentials in Human Stem Cell-Derived Cardiomyocytes with β-Myosin Mutation R723G. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.1496] [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: 10/25/2022] Open
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5
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Beer LA, Tatge H, Schneider C, Ruschig M, Hust M, Barton J, Thiemann S, Fühner V, Russo G, Gerhard R. The Binary Toxin CDT of Clostridium difficile as a Tool for Intracellular Delivery of Bacterial Glucosyltransferase Domains. Toxins (Basel) 2018; 10:toxins10060225. [PMID: 29865182 PMCID: PMC6024811 DOI: 10.3390/toxins10060225] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 05/28/2018] [Accepted: 05/30/2018] [Indexed: 12/16/2022] Open
Abstract
Binary toxins are produced by several pathogenic bacteria. Examples are the C2 toxin from Clostridium botulinum, the iota toxin from Clostridium perfringens, and the CDT from Clostridium difficile. All these binary toxins have ADP-ribosyltransferases (ADPRT) as their enzymatically active component that modify monomeric actin in their target cells. The binary C2 toxin was intensively described as a tool for intracellular delivery of allogenic ADPRTs. Here, we firstly describe the binary toxin CDT from C. difficile as an effective tool for heterologous intracellular delivery. Even 60 kDa glucosyltransferase domains of large clostridial glucosyltransferases can be delivered into cells. The glucosyltransferase domains of five tested large clostridial glucosyltransferases were successfully introduced into cells as chimeric fusions to the CDTa adapter domain (CDTaN). Cell uptake was demonstrated by the analysis of cell morphology, cytoskeleton staining, and intracellular substrate glucosylation. The fusion toxins were functional only when the adapter domain of CDTa was N-terminally located, according to its native orientation. Thus, like other binary toxins, the CDTaN/b system can be used for standardized delivery systems not only for bacterial ADPRTs but also for a variety of bacterial glucosyltransferase domains.
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Affiliation(s)
- Lara-Antonia Beer
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| | - Helma Tatge
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| | - Carmen Schneider
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| | - Maximilian Ruschig
- Department of Biochemistry and Biotechnology, Technical University Braunschweig, 38106 Braunschweig, Germany.
| | - Michael Hust
- Department of Biochemistry and Biotechnology, Technical University Braunschweig, 38106 Braunschweig, Germany.
| | - Jessica Barton
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| | - Stefan Thiemann
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
| | - Viola Fühner
- Department of Biochemistry and Biotechnology, Technical University Braunschweig, 38106 Braunschweig, Germany.
| | - Giulio Russo
- Department of Biochemistry and Biotechnology, Technical University Braunschweig, 38106 Braunschweig, Germany.
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
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6
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Wojciechowski D, Thiemann S, Schaal C, Rahtz A, de la Roche J, Begemann B, Becher T, Fischer M. Activation of renal ClC-K chloride channels depends on an intact N terminus of their accessory subunit barttin. J Biol Chem 2018; 293:8626-8637. [PMID: 29674316 DOI: 10.1074/jbc.ra117.000860] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 11/09/2017] [Revised: 04/17/2018] [Indexed: 12/27/2022] Open
Abstract
ClC-K channels belong to the CLC family of chloride channels and chloride/proton antiporters. They contribute to sodium chloride reabsorption in Henle's loop of the kidney and to potassium secretion into the endolymph by the stria vascularis of the inner ear. Their accessory subunit barttin stabilizes the ClC-K/barttin complex, promotes its insertion into the surface membrane, and turns the pore-forming subunits into a conductive state. Barttin mutations cause Bartter syndrome type IV, a salt-wasting nephropathy with sensorineural deafness. Here, studying ClC-K/barttin channels heterologously expressed in MDCK-II and HEK293T cells with confocal imaging and patch-clamp recordings, we demonstrate that the eight-amino-acids-long barttin N terminus is required for channel trafficking and activation. Deletion of the complete N terminus (Δ2-8 barttin) retained barttin and human hClC-Ka channels in intracellular compartments. Partial N-terminal deletions did not compromise subcellular hClC-Ka trafficking but drastically reduced current amplitudes. Sequence deletions encompassing Thr-6, Phe-7, or Arg-8 in barttin completely failed to activate hClC-Ka. Analyses of protein expression and whole-cell current noise revealed that inactive channels reside in the plasma membrane. Substituting the deleted N terminus with a polyalanine sequence was insufficient for recovering chloride currents, and single amino acid substitutions highlighted that the correct sequence is required for proper function. Fast and slow gate activation curves obtained from rat V166E rClC-K1/barttin channels indicated that mutant barttin fails to constitutively open the slow gate. Increasing expression of barttin over that of ClC-K partially recovered this insufficiency, indicating that N-terminal modifications of barttin alter both binding affinities and gating properties.
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Affiliation(s)
- Daniel Wojciechowski
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Stefan Thiemann
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Christina Schaal
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Alina Rahtz
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Jeanne de la Roche
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Birgit Begemann
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Toni Becher
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
| | - Martin Fischer
- From the Institute for Neurophysiology, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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7
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Durán-Garcia S, Lee J, Yki-Järvinen H, Rosenstock J, Hehnke U, Thiemann S, Patel S, Woerle HJ. Efficacy and safety of linagliptin as add-on therapy to basal insulin and metformin in people with Type 2 diabetes. Diabet Med 2016; 33:926-33. [PMID: 26605991 DOI: 10.1111/dme.13041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/18/2015] [Indexed: 12/17/2022]
Abstract
AIM To evaluate the efficacy and safety of linagliptin in people with Type 2 diabetes inadequately controlled on basal insulin and metformin. METHODS This was a post hoc subanalysis of participants who received basal insulin and metformin in a global phase III study that randomized participants (1:1) to receive linagliptin 5 mg once daily or placebo for ≥52 weeks as add-on therapy to basal insulin alone or in combination with metformin and/or pioglitazone. During the first 24 weeks, the background dose of basal insulin remained stable; thereafter, adjustments based on glucose concentrations were recommended. The primary endpoint of the subanalysis was the change from baseline in HbA1c after 24 weeks. The safety analysis incorporated data up to a maximum of 110 weeks. RESULTS A total of 950 participants receiving background insulin and metformin were included in this subanalysis (linagliptin and placebo, both n = 475). At week 24, the placebo-corrected adjusted mean (±se) change from baseline in HbA1c with linagliptin was -7 (±1) mmol/mol [-0.7 (±0.1) %; 95% CI -0.8, -0.6; P < 0.0001]. The overall frequency of drug-related adverse events (linagliptin, 18.9%; placebo, 21.9%) and investigator-reported hypoglycaemia (linagliptin, 30.7%; placebo, 31.6%) were similar in both groups at the end of treatment. The frequency of severe hypoglycaemia was low (linagliptin, 1.7%; placebo, 0.8%). No meaningful changes in mean (±sd) body weight were noted in either group [week 52: linagliptin, -0.5 (±3.2) kg; placebo, 0.0 (±3.1) kg]. CONCLUSIONS Linagliptin added to basal insulin and metformin improved glycaemic control, without increasing the risk of hypoglycaemia or body weight gain.
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Affiliation(s)
- S Durán-Garcia
- Valme University Hospital Medical School, Seville, Spain
| | - J Lee
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
| | - H Yki-Järvinen
- Department of Medicine, University of Helsinki, Helsinki, Finland
| | - J Rosenstock
- Dallas Diabetes and Endocrine Center at Medical City, Dallas, TX, USA
| | - U Hehnke
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
| | - S Thiemann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
| | - S Patel
- Boehringer Ingelheim Ltd, Bracknell, UK
| | - H-J Woerle
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
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8
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Gallwitz B, Thiemann S, Wörle H, Marx N. Kardiovaskuläre Studien-Endpunkte bei Typ-2-Diabetes und die Sulfonylharnstoff-Kontroverse: Rationale für die aktiv kontrollierte CAROLINA®-Studie. DIABETOL STOFFWECHS 2015. [DOI: 10.1055/s-0035-1553589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- B. Gallwitz
- Medizinische Klinik IV, Universitätsklinikum Tübingen, Tübingen, Germany
| | - S. Thiemann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
| | - H. Wörle
- Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim, Germany
| | - N. Marx
- Medizinische Klinik I, Universitätsklinikum Aachen, Aachen, Germany
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Schornbaum J, Zakharko Y, Held M, Thiemann S, Gannott F, Zaumseil J. Light-emitting quantum dot transistors: emission at high charge carrier densities. Nano Lett 2015; 15:1822-8. [PMID: 25652433 PMCID: PMC4358076 DOI: 10.1021/nl504582d] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 01/19/2015] [Indexed: 05/20/2023]
Abstract
For the application of colloidal semiconductor quantum dots in optoelectronic devices, for example, solar cells and light-emitting diodes, it is crucial to understand and control their charge transport and recombination dynamics at high carrier densities. Both can be studied in ambipolar, light-emitting field-effect transistors (LEFETs). Here, we report the first quantum dot light-emitting transistor. Electrolyte-gated PbS quantum dot LEFETs exhibit near-infrared electroluminescence from a confined region within the channel, which proves true ambipolar transport in ligand-exchanged quantum dot solids. Unexpectedly, the external quantum efficiencies improve significantly with current density. This effect correlates with the unusual increase of photoluminescence quantum yield and longer average lifetimes at higher electron and hole concentrations in PbS quantum dot thin films. We attribute the initially low emission efficiencies to nonradiative losses through trap states. At higher carrier densities, these trap states are deactivated and emission is dominated by trions.
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Affiliation(s)
- Julia Schornbaum
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Yuriy Zakharko
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Martin Held
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Stefan Thiemann
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Florentina Gannott
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Jana Zaumseil
- Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
- Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany
- E-mail:
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Ross SA, Caballero AE, Del Prato S, Gallwitz B, Lewis-D'Agostino D, Bailes Z, Thiemann S, Patel S, Woerle HJ, von Eynatten M. Initial combination of linagliptin and metformin compared with linagliptin monotherapy in patients with newly diagnosed type 2 diabetes and marked hyperglycaemia: a randomized, double-blind, active-controlled, parallel group, multinational clinical trial. Diabetes Obes Metab 2015; 17:136-44. [PMID: 25298165 DOI: 10.1111/dom.12399] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/22/2014] [Accepted: 09/30/2014] [Indexed: 12/18/2022]
Abstract
AIMS To evaluate glucose-lowering treatment strategies with linagliptin and metformin in people with newly diagnosed type 2 diabetes and marked hyperglycaemia, a prevalent population for which few dedicated studies of oral antidiabetes drugs have been conducted. METHODS A total of 316 patients, with type 2 diabetes diagnosed for ≤12 months and with glycated haemoglobin (HbA1c) concentration in the range 8.5-12.0%, were randomized 1:1 to double-blind, free-combination treatment with linagliptin 5 mg once daily and metformin twice daily (uptitrated to 2000 mg/day maximum) or to linagliptin monotherapy. The primary endpoint was change in HbA1c concentration from baseline at week 24 (per-protocol completers' cohort: n = 245). RESULTS The mean (standard deviation) age and HbA1c at baseline were 48.8 (11.0) years and 9.8 (1.1)%, respectively. At week 24, the mean ± standard error (s.e.) HbA1c decreased from baseline by -2.8 ± 0.1% with linagliptin/metformin and -2.0 ± 0.1% with linagliptin; a treatment difference of -0.8% (95% confidence interval -1.1 to -0.5; p <0.0001). Similar results were observed in a sensitivity analysis based on intent-to-treat principles: adjusted mean ± s.e. changes in HbA1c of -2.7 ± 0.1% and -1.8 ± 0.1%, respectively; treatment difference of -0.9% (95% CI -1.3 to -0.6; p <0.0001). A treatment response of HbA1c <7.0% was achieved by 61 and 40% of patients in the linagliptin/metformin and linagliptin groups, respectively. Few patients experienced drug-related adverse events (8.8 and 5.7% of patients in the linagliptin/metformin and linagliptin groups, respectively). Hypoglycaemia occurred in 1.9 and 3.2% of patients in the linagliptin/metformin and linagliptin groups, respectively (no severe episodes). Body weight decreased significantly with the combination therapy (-1.3 kg between-group difference; p =0.0033). CONCLUSIONS Linagliptin in initial combination with metformin in patients with newly diagnosed type 2 diabetes and marked hyperglycaemia, an understudied group, elicited significant improvements in glycaemic control with a low incidence of hypoglycaemia, weight gain or other adverse effects. These results support early combination treatment strategies and suggest that newly diagnosed patients with marked hyperglycaemia may be effectively managed with oral, non-insulin therapy.
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Affiliation(s)
- S A Ross
- University of Calgary, LMC Endocrinology Centres, Calgary, Alberta, Canada
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11
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Lokteva I, Thiemann S, Gannott F, Zaumseil J. Ambipolar, low-voltage and low-hysteresis PbSe nanowire field-effect transistors by electrolyte gating. Nanoscale 2013; 5:4230-4235. [PMID: 23545580 DOI: 10.1039/c3nr33723e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Semiconductor nanowire field-effect transistors (FETs) are interesting for fundamental studies of charge transport as well as possible applications in electronics. Here, we report low-voltage, low-hysteresis and ambipolar PbSe nanowire FETs using electrolyte-gating with ionic liquids and ion gels. We obtain balanced hole and electron mobilities at gate voltages below 1 V. Due to the large effective capacitance of the ionic liquids and thus high charge carrier densities electrolyte-gated nanowire FETs are much less affected by external doping and traps than nanowire FETs with traditional dielectrics such as SiO2. The observed current-voltage characteristics and on/off ratios indicate almost completely transparent Schottky barriers and efficient ambipolar charge injection into a low band gap one-dimensional semiconductor. Finally, we explore the possibility of applying these ambipolar nanowire FETs in complementary inverters for printed electronics.
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Affiliation(s)
- Irina Lokteva
- Institute of Polymer Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Martensstraße 7, D-91058 Erlangen, Germany
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12
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Yki-Jarvinen H, Rosenstock J, Durán-Garcia S, Pinnetti S, Bhattacharya S, Thiemann S, Patel S, Woerle HJ. Langzeitwirksamkeit und -verträglicheit von Linagliptin als Add-on-Therapie zu Basalinsulin bei Patienten mit Typ-2-Diabetes: eine 52-wöchige randomisierte, Placebo-kontrollierte Studie. DIABETOL STOFFWECHS 2013. [DOI: 10.1055/s-0033-1341901] [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: 10/26/2022]
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13
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Araki E, Kawamori R, Inagaki N, Watada H, Hayashi N, Horie Y, Sarashina A, Thiemann S, von Eynatten M, Dugi K, Woerle HJ. Long-term safety of linagliptin monotherapy in Japanese patients with type 2 diabetes. Diabetes Obes Metab 2013; 15:364-71. [PMID: 23163910 DOI: 10.1111/dom.12039] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 09/11/2012] [Accepted: 11/12/2012] [Indexed: 12/22/2022]
Abstract
AIMS In a phase III study conducted among Japanese patients with type 2 diabetes mellitus (T2DM), linagliptin 5 and 10 mg showed clinically meaningful improvements in glycaemic parameters after 12 and 26 weeks compared with placebo and voglibose, respectively. This extension study assessed long-term tolerability of linagliptin over 52 weeks. METHODS Japanese patients with T2DM who completed either phase of a 12-week/26-week study comparing linagliptin monotherapy with placebo or voglibose were eligible to enrol. In the extension study, the comparator groups switched to linagliptin 5 or 10 mg, while the linagliptin groups maintained dosage. RESULTS In all, 540 patients received at least one dose of linagliptin 5 or 10 mg and 494 completed the extension. Long-term treatment with linagliptin was well tolerated; adverse events (AEs) of special interest and serious AEs occurred in small percentages of patients. Drug-related AEs occurred in 10.2 and 10.6% of patients in the linagliptin 5- and 10-mg groups, respectively, and discontinuations due to drug-related AEs occurred in 1.1 and 0.7%, respectively. Only one (0.4%) patient in each dose group experienced investigator-defined hypoglycaemia during the treatment period (both events were non-severe). Body weight was not clinically altered in either group. The glycated haemoglobin A1c profiles over time were similar with linagliptin 5 and 10 mg. CONCLUSIONS These findings provide evidence for the safety and tolerability of oral linagliptin at either 5 or 10 mg for up to 52 weeks for the treatment of Japanese patients with T2DM, without clinically relevant increase in the risk of hypoglycaemia or weight gain.
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Affiliation(s)
- E Araki
- Department of Metabolic Medicine, Kumamoto University Graduate School of Medicine, Kumamoto, Japan
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Thiemann S, Gruber M, Lokteva I, Hirschmann J, Halik M, Zaumseil J. High-mobility ZnO nanorod field-effect transistors by self-alignment and electrolyte-gating. ACS Appl Mater Interfaces 2013; 5:1656-1662. [PMID: 23398625 DOI: 10.1021/am3026739] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
High mobility, solution-processed field-effect transistors are important building blocks for flexible electronics. Here we demonstrate the alignment of semiconducting, colloidal ZnO nanorods by a simple solvent evaporation technique and achieve high electron mobilities in field-effect transistors at low operating voltages by electrolyte-gating with ionic liquids. The degree of alignment varies with nanorod length, concentration and solvent evaporation rate. We find a strong dependence of electron mobility on the degree of alignment but less on the length of the nanorods. Maximum field-effect mobilities reach up to 9 cm(2) V(-1) s(-1) for optimal alignment. Because of the low process temperature (150 °C), ZnO nanorod thin films are suitable for application on flexible polymer substrates.
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Affiliation(s)
- Stefan Thiemann
- Institute of Polymer Materials, Friedrich-Alexander Universität Erlangen-Nürnberg, Martensstrasse 7, D-91058 Erlangen, Germany
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Barnett AH, Patel S, Harper R, Toorawa R, Thiemann S, von Eynatten M, Woerle HJ. Linagliptin monotherapy in type 2 diabetes patients for whom metformin is inappropriate: an 18-week randomized, double-blind, placebo-controlled phase III trial with a 34-week active-controlled extension. Diabetes Obes Metab 2012; 14:1145-54. [PMID: 22974280 DOI: 10.1111/dom.12011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 08/06/2012] [Accepted: 09/06/2012] [Indexed: 12/24/2022]
Abstract
AIMS To investigate the efficacy and safety of linagliptin, a dipeptidyl peptidase-4 inhibitor, in type 2 diabetes mellitus (T2DM) patients for whom metformin was inappropriate. METHODS This 1-year double-blind study (ClinicalTrials.gov, NCT00740051) enrolled T2DM patients with inadequate glycaemic control, treatment-naïve [glycated haemoglobin (HbA1c) 7.0-10.0%] or previously treated with one oral antidiabetes drug (HbA1c 6.5-9.0% before washout), ineligible for metformin because of contraindications (e.g. renal impairment) or previous intolerable side effects. Patients were randomized to monotherapy with linagliptin 5 mg once daily (n = 151) or placebo (n = 76) for 18 weeks, after which placebo patients switched to glimepiride 1-4 mg once daily and treatments continued for another 34 weeks. The primary endpoint was change from baseline in HbA1c after 18 weeks (full-analysis set, last observation carried forward). RESULTS At week 18, adjusted mean difference in change from baseline HbA1c (8.1%) was -0.60% (95% confidence interval -0.88, -0.32; p < 0.0001) (-0.39% with linagliptin, +0.21% with placebo). At week 52, mean HbA1c was decreased from baseline in both groups [linagliptin: -0.44%; placebo/glimepiride: -0.72% (observed cases)]. Adverse events occurred in 40.4 and 48.7% of linagliptin and placebo patients, respectively, during the initial 18 weeks. During the 34-week extension, patients receiving linagliptin experienced less hypoglycaemia (2.2% vs. 7.8%) and no weight gain (mean change from baseline of -0.2 and +1.3 kg, respectively) compared with glimepiride patients. CONCLUSIONS In T2DM patients for whom metformin was inappropriate, linagliptin improved glycaemic control and was well tolerated, with less hypoglycaemia and relative weight loss compared with glimepiride.
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Affiliation(s)
- A H Barnett
- Diabetes Centre, Heart of England NHS Foundation Trust and University of Birmingham, Birmingham, UK
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Hahn R, Schmidt-Stein F, Salonen J, Thiemann S, Song Y, Kunze J, Lehto VP, Schmuki P. Semimetallic TiO2Nanotubes. Angew Chem Int Ed Engl 2009; 48:7236-9. [DOI: 10.1002/anie.200902207] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Becker HD, Gat M, Thiemann S. Vibration Response Imaging (VRI) bei der Anwendung in einer internistischen Allgemeinpraxis – eine Machbarkeitsstudie. Pneumologie 2008. [DOI: 10.1055/s-2008-1074225] [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: 10/21/2022]
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Hobeika E, Thiemann S, Storch B, Jumaa H, Nielsen PJ, Pelanda R, Reth M. Testing gene function early in the B cell lineage in mb1-cre mice. Proc Natl Acad Sci U S A 2006; 103:13789-94. [PMID: 16940357 PMCID: PMC1564216 DOI: 10.1073/pnas.0605944103] [Citation(s) in RCA: 453] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mb1 gene encodes the Ig-alpha signaling subunit of the B cell antigen receptor and is expressed exclusively in B cells beginning at the very early pro-B cell stage in the bone marrow. We examine here the efficacy of the mb1 gene as a host locus for cre recombinase expression in B cells. We show that by integrating a humanized cre recombinase into the mb1 locus we obtain extraordinarily efficient recombination of loxP sites in the B cell lineage. The results from a variety of reporter genes including the splicing factor SRp20 and the DNA methylase Dnmt1 suggest that mb1-cre is probably the best model so far described for pan-B cell-specific cre expression. The availability of a mouse line with efficient cre-mediated recombination at an early developmental stage in the B lineage provides an opportunity to study the role of various genes specifically in B cell development and function.
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Affiliation(s)
- E. Hobeika
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - S. Thiemann
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - B. Storch
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - H. Jumaa
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - P. J. Nielsen
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - R. Pelanda
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
| | - M. Reth
- Max Planck Institute of Immunobiology, Stuebeweg 51, 79108 Freiburg, Germany
- To whom correspondence should be addressed. E-mail:
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20
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Eberhardt C, Raussen W, Thiemann S, Schwarz M, Bauss F, Kurth AA. [Improved osseointegration and periprosthetic bone volume around cementless metal implants under bisphosphonate treatment]. ACTA ACUST UNITED AC 2006; 143:645-51. [PMID: 16380896 DOI: 10.1055/s-2005-836752] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
AIM The effects of a systemic treatment with the bisphosphonate ibandronate on osseointegration of uncoated and hydroxyapatite-coated titanium implants and on periprosthetic bone volume have been evaluated and the dosage of medication had to be defined. METHOD We used an animal model of the rat, the animals were assigned to three treatment groups receiving 1 microg, 5 microg and 25 microg/kg body weight and one control group receiving NaCl 0.9%. An uncoated and a hydroxyapatite-coated titanium rod were inserted into the medullary canal of the femur. After 28 days the specimens were harvested and histomorphometric evaluation revealed extend of osseointegrated implant surface and changes of periprosthetic bone volume. RESULTS Treatment groups receiving 5 microg and 25 microg ibandronate showed significant improvement of osseointegrated implant surface compared to the control group. Enhancement of periprosthetic bone volume was revealed in all treatment groups but only application of 25 microg ibandronate was significantly improved compared to the control group. CONCLUSION A minor dose of 1 microg ibandronate is not effective to improve osseointegration. A high dosed bisphosphonate treatment with 5 microg or 25 microg ibandronate is potent to improve osseointegrated implant surface significantly compared to an untreated control in both uncoated and hydroxyapatite-coated titanium implants and to enhance periprosthetic bone volume. By that, improved secondary stability and prolonged survival time of cementless metal implants can be expected.
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Affiliation(s)
- C Eberhardt
- Orthopädische Universitäts- und Poliklinik Frankfurt.
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Gartrell NK, Koh AS, Becker C, LaVoy A, Rosen S, Thiemann S. Prevalence of hormone replacement therapy and antidepressant use in peri- and postmenopausal women. J Gend Specif Med 2001; 4:60-3. [PMID: 11324242] [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: 02/19/2023]
Abstract
OBJECTIVE To examine the prevalence of hormone replacement therapy (HRT) and antidepressant use in peri- and postmenopausal women. DESIGN Prevalence survey. SUBJECTS Peri- and postmenopausal outpatients (N = 253) at five medical clinics. METHODS Participants completed a 47-item questionnaire requesting information on mood changes associated with menstruation, childbirth, oral contraceptive use, and menopause. Peri- and postmenopausal participants were asked to rate the severity of dysphoric symptoms experienced during the menopausal transition and to specify whether HRT, antianxiety medication, or antidepressant medication relieved the symptoms. RESULTS Forty percent of respondents experienced more severe depression than anticipated during menopause, but only 8% were treated with antidepressants. Forty-six percent of respondents were treated with HRT. CONCLUSIONS The data suggest that antidepressant and antianxiety medications are more helpful than HRT in relieving peri- and postmenopausal depression or anxiety. However, most women managed the mood changes associated with menopause without psychopharmacologic intervention. This is consistent with other reports on the transitory nature of peri- and postmenopausal depression for most women.
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Affiliation(s)
- N K Gartrell
- Department of Psychiatry, University of California, San Francisco, USA
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Abstract
OBJECTIVE In obsessive-compulsive disorder, the relationship between blood levels of serotonin reuptake inhibitors and clinical outcome is unclear. In a multicenter trial, the authors examined the relationship between steady state plasma levels of fluoxetine and norfluoxetine (determined after 7 weeks of treatment), and their sum, and clinical outcome. METHOD Ratings of symptom severity of obsessive-compulsive disorder (Yale-Brown Obsessive Compulsive Scale scores) were obtained at baseline and after 13 weeks for 200 adult outpatients with moderately severe obsessive-compulsive disorder treated with fluoxetine doses of 20 mg/day (N = 68), 40 mg/day (N = 64), and 60 mg/day (N = 68). RESULTS Mean plasma levels of fluoxetine and norfluoxetine were statistically significantly higher with higher dose. Statistical analyses revealed no significant relationship for plasma level of either molecule or their sum in predicting endpoint percent change in obsessive-compulsive scores. Plasma levels of patients with a marked response (decrease of 50% or more in obsessive-compulsive score) did not differ significantly from those of nonresponders (less than a 25% decrease in obsessive-compulsive score). No hint was seen of a therapeutic window or of a relationship limited to one gender or within the lowest dose group (20 mg/day). However, since S-norfluoxetine is a much more potent serotonin reuptake inhibitor than R-norfluoxetine, the absence of chiral (stereospecific) assays in this study limits the results. CONCLUSIONS Steady state plasma levels of fluoxetine and norfluoxetine are not related to clinical outcome in patients with obsessive-compulsive disorder. Individual patients can be told only that the optimum dose of fluoxetine for them will be the dose that produces the largest therapeutic effect with the smallest side effect burden. Future studies should examine the predictive utility of measures of serotonergic neuronal function and, if plasma levels of norfluoxetine are examined, the use of chiral assays.
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Affiliation(s)
- L M Koran
- Department of Psychiatry, Stanford University School of Medicine, CA, USA
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Gartrell NK, Milliken N, Goodson WH, Thiemann S, Lo B. Physician-patient sexual contact. Prevalence and problems. West J Med 1992; 157:139-43. [PMID: 1441462 PMCID: PMC1011231] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To document the current prevalence of physician-patient sexual contact and to estimate its effect on involved patients, 10,000 family practitioners, internists, obstetrician-gynecologists, and surgeons were surveyed. Of the 1,891 respondents, 9% acknowledged sexual contact with 1 or more patients. Even in the unlikely case that none of the nonrespondents had sexual contact with patients, its prevalence among all 10,000 physicians surveyed would still be 2%. Of respondents, 23% had at least 1 patient who reported sexual contact with another physician; 63% thought this contact was "always harmful" to the patients. Almost all (94%) responding physicians opposed sexual contact with current patients; 37% also opposed sexual contact with former patients. More than half of respondents (56%) indicated that physician-patient sexual contact had never been addressed in their training; only 3% had participated in a continuing education course focusing on this issue. Clear and enforceable medical ethics codes concerning physician-patient sexual contact are needed, as well as preventive educational programs for medical schools and residency programs.
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Affiliation(s)
- N K Gartrell
- Department of Psychiatry, University of California, San Francisco
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Abstract
Soft data are defined as measures having substantial intrasubject variability due to errors of measurement or to the inconsistency of subjects' responses. Such data are often important measures of response in randomized clinical trials. In this context, we show that using an intensive design and the slope of response on time as the outcome measure (a) maximizes sample retention and (b) decreases within-group variability, thus (c) maximizing the power of test procedures without requiring increased sample sizes.
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Abstract
Soft data are defined as measures having substantial intrasubject variability due to errors of measurement or to the inconsistency of subjects' responses. Such data are often important measures of response in randomized clinical trials. In this context, we show that using an intensive design and the slope of response on time as the outcome measure (a) maximizes sample retention and (b) decreases within-group variability, thus (c) maximizing the power of test procedures without requiring increased sample sizes.
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Whiteford HA, Peabody CA, Thiemann S, Kraemer HC, Csernansky JG, Berger PA. The effect of age on baseline and postdexamethasone cortisol levels in major depressive disorder. Biol Psychiatry 1987; 22:1029-32. [PMID: 3607127 DOI: 10.1016/0006-3223(87)90013-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Prosser ES, Csernansky JG, Kaplan J, Thiemann S, Becker TJ, Hollister LE. Depression, parkinsonian symptoms, and negative symptoms in schizophrenics treated with neuroleptics. J Nerv Ment Dis 1987; 175:100-5. [PMID: 2879880 DOI: 10.1097/00005053-198702000-00006] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To determine whether depression and neuroleptic-induced parkinsonism confound the clinical assessment of negative symptoms in schizophrenics, we evaluated 45 outpatient schizophrenics for depression, parkinsonian symptoms, and negative symptoms using standard clinical rating scales. Neuroleptic and anticholinergic dose and plasma activity were also determined. Associations between negative symptoms and these clinical and drug variables were examined using a multivariate statistical model. Negative symptoms were significantly correlated with several parkinsonian symptoms, some vegetative features of depression, and with anticholinergic dose. No significant correlations were found between negative symptoms and cognitive features of depression, or neuroleptic and anticholinergic plasma activity. These findings suggest that assessment criteria for negative symptoms, depression, and drug-induced parkinsonism overlap in treated schizophrenics. Strategies for differentiating these clinical syndromes are discussed.
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Abstract
Two measures of negative schizophrenic symptoms, the Scale for the Assessment of Negative Symptoms and the withdrawal-retardation subscale of the Brief Psychiatric Rating Scale, are found to be redundant when used together. Studies incorporating redundant measures have numerous disadvantages. Using multiple scales increases the cost and effort for the investigator, places a greater burden on research subjects, and compromises the interpretability of findings by increasing the probability of both Type I and Type II errors. A strategy for evaluating the use of multiple rating scales is suggested, and the theoretical basis of this strategy is discussed.
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Abstract
Principal component analysis was performed on data obtained for the concentrations of 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylethylene glycol, homovanillic acid, and 5-hydroxyindoleacetic acid in lumbar cerebrospinal fluid from a group of normal volunteers (n = 40), hypersomniac patients (n = 13), and narcoleptic patients (n = 8). All four compounds were shown to be highly intercorrelated in the normal volunteers. In the hypersomniac patients, 3-methoxy-4-hydroxyphenylethylene glycol did not appear to be correlated with the other three compounds. In the narcoleptic patients, homovanillic acid and 3,4-dihydroxyphenylacetic acid appeared not to be correlated with the other two metabolites. The results provide tentative support for a neurochemical distinction between narcolepsy and hypersomnia and suggest that attention should be given to a possible malfunction of the dopamine system in narcolepsy and norepinephrine in hypersomnia.
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Abstract
A previous study suggested that schizophrenic subjects exhibit an impaired ability to correct their own errors of movement without using exteroceptive signals. However, the performance of schizophrenic subjects was compared to that of only one other psychiatric group (alcoholic subjects), and a relatively small number of subjects was studied. To investigate the specificity of the postulated impairment, 9 schizophrenic, 11 depressed, and 8 normal subjects performed a tracking task designed to prevent the use of exteroceptive cues in correcting errors of movement. The depressed and normal groups did not differ significantly on any performance measure, but the schizophrenic subjects again demonstrated a gross impairment in correcting errors, yet no impairment in initiating correct responses. These findings suggest that the impaired ability to monitor ongoing motor behavior on the basis of internal, self-generated cues may be specific to schizophrenia among major psychiatric disorders.
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Abstract
We measured the dopamine metabolite homovanillic acid (HVA) in cerebrospinal fluid (CSF) before and after probenecid administration in normal controls and in patients with Huntington's disease. Baseline CSF HVA concentrations correlated positively with age in normal control subjects. Baseline CSF HVA concentrations were reduced in patients with Huntington's disease, and the degree of this reduction correlated with the severity of dementia and with the duration of disease. These results suggest that changes in the metabolism of dopamine by dopaminergic neurons may be associated with the dementia of Huntington's disease as well as with normal aging. These changes in dopaminergic functioning are apparently different in Huntington's disease than in normal aging and can be detected by measuring CSF HVA concentration.
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Peabody CA, Thiemann S, Pigache R, Miller TP, Berger PA, Yesavage J, Tinklenberg JR. Desglycinamide-9-arginine-8-vasopressin (DGAVP, Organon 5667) in patients with dementia. Neurobiol Aging 1985; 6:95-100. [PMID: 3895014 DOI: 10.1016/0197-4580(85)90024-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vasopressin peptides have been shown to facilitate learning and memory in both animals and humans; however, the effectiveness in humans is controversial. In a double blind parallel group study, 17 demented subjects (either Alzheimer's or alcoholic) were given either desglycinamide-9-arginine-8-vasopressin (DGAVP) 92 micrograms intranasally TID or an identical placebo for 1 week after having received 1 week of placebo. To our knowledge, this is the first report of DGAVP being used in subjects with dementia. The DGAVP group had a statistically significant improvement on the Buschke list learning of low imagery words. However, for various reasons discussed in the paper, we feel this finding needs to be replicated before any definite conclusions can be drawn. Since there were no other appreciable behavioral effects of this DGAVP regimen, our results should be considered negative. There was no evidence of any DGAVP-related adverse effects, except for possible weight gain.
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King R, Faull KF, Stahl SM, Mefford IN, Thiemann S, Barchas JD, Berger PA. Serotonin and schizophrenia: correlations between serotonergic activity and schizophrenic motor behavior. Psychiatry Res 1985; 14:235-40. [PMID: 2408290 DOI: 10.1016/0165-1781(85)90018-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Increased serotonergic activity in animals has been associated with a variety of stereotyped motor behaviors. In addition, serotonin facilitates brainstem, reticular, and spinal motor neuronal activity implicated in the expression of these behaviors. This report presents positive correlations between both peripheral (platelet serotonin levels) and central (cerebrospinal concentrations of 5-hydroxy-indoleacetic acid) measures of serotonin metabolism and the symptom of peculiar or unusual mannerisms and posturing in schizophrenic patients. The findings are discussed in light of the animal behavioral correlates of increased serotonergic activity and the stereotyped affectomotor behavior seen in some schizophrenic patients.
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Thiemann S, Faull KF, Kraemer HC, Barchas JD, Berger PA. CSF probenecid and biogenic amines. Biol Psychiatry 1984; 19:1357-8. [PMID: 6498258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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