1
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Hussaini S, Mamyraiym Kyzy A, Schröder-Schetelig J, Lädke SL, Venkatesan V, Diaz-Maue L, Quiñonez Uribe RA, Richter C, Biktashev VN, Majumder R, Krinski V, Luther S. Efficient termination of cardiac arrhythmias using optogenetic resonant feedback pacing. Chaos 2024; 34:031103. [PMID: 38526981 DOI: 10.1063/5.0191519] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/03/2024] [Indexed: 03/27/2024]
Abstract
Malignant cardiac tachyarrhythmias are associated with complex spatiotemporal excitation of the heart. The termination of these life-threatening arrhythmias requires high-energy electrical shocks that have significant side effects, including tissue damage, excruciating pain, and worsening prognosis. This significant medical need has motivated the search for alternative approaches that mitigate the side effects, based on a comprehensive understanding of the nonlinear dynamics of the heart. Cardiac optogenetics enables the manipulation of cellular function using light, enhancing our understanding of nonlinear cardiac function and control. Here, we investigate the efficacy of optically resonant feedback pacing (ORFP) to terminate ventricular tachyarrhythmias using numerical simulations and experiments in transgenic Langendorff-perfused mouse hearts. We show that ORFP outperforms the termination efficacy of the optical single-pulse (OSP) approach. When using ORFP, the total energy required for arrhythmia termination, i.e., the energy summed over all pulses in the sequence, is 1 mJ. With a success rate of 50%, the energy per pulse is 40 times lower than with OSP with a pulse duration of 10 ms. We demonstrate that even at light intensities below the excitation threshold, ORFP enables the termination of arrhythmias by spatiotemporal modulation of excitability inducing spiral wave drift.
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Affiliation(s)
- S Hussaini
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - A Mamyraiym Kyzy
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - J Schröder-Schetelig
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - S L Lädke
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - V Venkatesan
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - L Diaz-Maue
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
- Research Electronics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - R A Quiñonez Uribe
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - C Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
- WG Cardiovascular Optogenetics, Lab Animal Science Unit, Leibniz Institute for Primate Research, Göttingen 37077, Germany
| | - V N Biktashev
- Department of Mathematics and Statistics, University of Exeter, Exeter EX4 4QF, United Kingdom
| | - R Majumder
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
| | - V Krinski
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
| | - S Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organisation, Göttingen 37077, Germany
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen 37075, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Lower Saxony, Göttingen 37075, Germany
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2
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Stenger R, Herzog S, Kottlarz I, Rüchardt B, Luther S, Wörgötter F, Parlitz U. Reconstructing in-depth activity for chaotic 3D spatiotemporal excitable media models based on surface data. Chaos 2023; 33:013134. [PMID: 36725654 DOI: 10.1063/5.0126824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 12/22/2022] [Indexed: 06/18/2023]
Abstract
Motivated by potential applications in cardiac research, we consider the task of reconstructing the dynamics within a spatiotemporal chaotic 3D excitable medium from partial observations at the surface. Three artificial neural network methods (a spatiotemporal convolutional long-short-term-memory, an autoencoder, and a diffusion model based on the U-Net architecture) are trained to predict the dynamics in deeper layers of a cube from observational data at the surface using data generated by the Barkley model on a 3D domain. The results show that despite the high-dimensional chaotic dynamics of this system, such cross-prediction is possible, but non-trivial and as expected, its quality decreases with increasing prediction depth.
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Affiliation(s)
- R Stenger
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - S Herzog
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - I Kottlarz
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - B Rüchardt
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - F Wörgötter
- Department for Computational Neuroscience, Third Institute of Physics-Biophysics, University of Göttingen, 37077 Göttingen, Germany
| | - U Parlitz
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
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3
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Biasci V, Santini L, Hussaini S, Ferrantini C, Coppini R, Loew LM, Luther S, Campione M, Poggesi C, Pavone FS, Cerbai E, Bub G, Sacconi L. Optogenetic manipulation of cardiac electrical dynamics using sub-threshold illumination: dissecting the role of cardiac alternans in terminating rapid rhythms. Cardiovasc Res 2022. [DOI: 10.1093/cvr/cvac066.161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Cardiac action potential (AP) shape and propagation are regulated by several key dynamic factors such as ions channel recovery and intracellular Ca2+-cycling. Experimental methods for manipulating AP electrical dynamics commonly use ion channel inhibitors that lack spatial and temporal specificity. In this work, we propose a novel approach based on optogenetics to manipulate cardiac electrical activity employing a light-modulated depolarizing current with intensities that are too low to elicit APs (sub-threshold illumination) but are sufficient to fine-tune AP electrical dynamics. We investigated the effects of sub-threshold illumination in isolated cardiomyocytes and whole hearts by using transgenic mice constitutively expressing a light-gated ion channel (channelrhodopsins-2, ChR2). We find that ChR2-mediated depolarizing current prolongs APs and reduces conduction velocity (CV) in a space-selective and reversible manner. Sub-threshold manipulation also affects the dynamics of cardiac electrical activity, increasing the magnitude of cardiac alternans. We use an optical system that uses real-time feedback control to generate re-entrant circuits with user-defined cycle lengths to explore the role that cardiac alternans plays in spontaneous termination of ventricular tachycardias (VTs). We find that VT stability significantly decreases during sub-threshold illumination primarily due to an increase in the amplitude of electrical oscillations, which implies that cardiac alternans may be beneficial in the context of self-termination of VT.
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Affiliation(s)
- V Biasci
- LENS - European Laboratory for Non-Linear Spectroscopy, University of Florence , Sesto Fiorentino , Italy
| | - L Santini
- University of Florence, Dept NeuroFarBa , Florence , Italy
| | - S Hussaini
- Max Planck Institute for Dynamics and Self-Organization , Gottingen , Germany
| | - C Ferrantini
- University of Florence, Department of Experimental and Clinical Medicine , Firenze , Italy
| | - R Coppini
- University of Florence, Dept NeuroFarBa , Florence , Italy
| | - LM Loew
- University of Connecticut, Center for Cell Analysis and Modeling , Farmington , United States of America
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization , Gottingen , Germany
| | - M Campione
- University of Padua, Department of Biomedical Science , Padova , Italy
| | - C Poggesi
- University of Florence, Department of Experimental and Clinical Medicine , Firenze , Italy
| | - FS Pavone
- LENS - European Laboratory for Non-Linear Spectroscopy, University of Florence , Sesto Fiorentino , Italy
| | - E Cerbai
- LENS - European Laboratory for Non-Linear Spectroscopy, University of Florence , Sesto Fiorentino , Italy
| | - G Bub
- Mcgill University, Department of Physiology , Montreal , Canada
| | - L Sacconi
- LENS - European Laboratory for Non-Linear Spectroscopy, University of Florence , Sesto Fiorentino , Italy
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Alistar A, Morris B, Luther S, Pardee T, Morganstein N, Alpert J, Burak N. P-222 GA CPI 613: A single-arm, open-label phase I study of CPI-613 in combination with gemcitabine and nab-paclitaxel for patients with locally advanced or metastatic pancreatic cancer. Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.04.312] [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: 11/01/2022] Open
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Sahai V, Chang A, Crysler O, Zhen D, Luther S, Zalupski M. P-176 A multicenter, randomized phase 1b/2 study of gemcitabine and cisplatin with or without CPI-613 as first-line therapy for patients with advanced unresectable biliary tract cancer (BilT-04). Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.05.231] [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: 10/20/2022] Open
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6
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Nikolaenko L, Pardee TS, Steiner R, Abramson JS, Horwitz S, Matasar M, Owens C, Rodriguez‐Rivera I, Straus D, Luther S, Noy A. PRELIMINARY ACTIVITY OF DEVIMISTAT (CPI 613) IN PATIENTS WITH RELAPSED OR REFRACTORY BURKITT LYMPHOMA/LEUKEMIA. Hematol Oncol 2021. [DOI: 10.1002/hon.84_2881] [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: 11/11/2022]
Affiliation(s)
- L. Nikolaenko
- City of Hope Hematology & Hematopoietic Cell Transplantation Duarte CA USA
| | - T. S. Pardee
- Wake Forrest Baptist Health Hematology Winston Salem NC USA
| | - R. Steiner
- MD Anderson Cancer Center Lymphoma‐Myeloma Houston TX USA
| | - J. S. Abramson
- Massachusetts General Hospital Cancer Center Medicine/Lymphoma Boston MA USA
| | - S. Horwitz
- Memorial Sloan Kettering Cancer Center Medicine/Lymphoma New York USA
| | - M. Matasar
- Memorial Sloan Kettering Cancer Center Medicine/Lymphoma New York USA
| | - C. Owens
- Memorial Sloan Kettering Cancer Center Medicine/Lymphoma New York USA
| | | | - D. Straus
- Memorial Sloan Kettering Cancer Center Medicine/Lymphoma New York USA
| | - S. Luther
- Rafael Pharmaceuticals Chief Business Officer Cranbury NJ USA
| | - A. Noy
- Memorial Sloan Kettering Cancer Center Medicine/Lymphoma New York USA
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7
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Quinonez Uribe RA, Luther S, Richter C. P2835Low-energy control of spatiotemporal cardiac dynamics using structured photo-stimulation. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p2835] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- R A Quinonez Uribe
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - C Richter
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
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8
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Christoph J, Chebbok M, Richter C, Schröder-Schetelig J, Bittihn P, Stein S, Uzelac I, Fenton FH, Hasenfuß G, Gilmour RF, Luther S. Electromechanical vortex filaments during cardiac fibrillation. Nature 2018; 555:667-672. [PMID: 29466325 DOI: 10.1038/nature26001] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/14/2018] [Indexed: 11/09/2022]
Abstract
The self-organized dynamics of vortex-like rotating waves, which are also known as scroll waves, are the basis of the formation of complex spatiotemporal patterns in many excitable chemical and biological systems. In the heart, filament-like phase singularities that are associated with three-dimensional scroll waves are considered to be the organizing centres of life-threatening cardiac arrhythmias. The mechanisms that underlie the onset, maintenance and control of electromechanical turbulence in the heart are inherently three-dimensional phenomena. However, it has not previously been possible to visualize the three-dimensional spatiotemporal dynamics of scroll waves inside cardiac tissues. Here we show that three-dimensional mechanical scroll waves and filament-like phase singularities can be observed deep inside the contracting heart wall using high-resolution four-dimensional ultrasound-based strain imaging. We found that mechanical phase singularities co-exist with electrical phase singularities during cardiac fibrillation. We investigated the dynamics of electrical and mechanical phase singularities by simultaneously measuring the membrane potential, intracellular calcium concentration and mechanical contractions of the heart. We show that cardiac fibrillation can be characterized using the three-dimensional spatiotemporal dynamics of mechanical phase singularities, which arise inside the fibrillating contracting ventricular wall. We demonstrate that electrical and mechanical phase singularities show complex interactions and we characterize their dynamics in terms of trajectories, topological charge and lifetime. We anticipate that our findings will provide novel perspectives for non-invasive diagnostic imaging and therapeutic applications.
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Affiliation(s)
- J Christoph
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Institute for Nonlinear Dynamics, University of Göttingen, Göttingen, Germany
| | - M Chebbok
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Department for Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - C Richter
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Department for Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - J Schröder-Schetelig
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Institute for Nonlinear Dynamics, University of Göttingen, Göttingen, Germany
| | - P Bittihn
- BioCircuits Institute, University of California San Diego, La Jolla, California, USA
| | - S Stein
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,Institute for Nonlinear Dynamics, University of Göttingen, Göttingen, Germany
| | - I Uzelac
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - F H Fenton
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - G Hasenfuß
- German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Department for Cardiology and Pneumology, University Medical Center Göttingen, Göttingen, Germany
| | - R F Gilmour
- University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.,Institute for Nonlinear Dynamics, University of Göttingen, Göttingen, Germany.,Institute of Pharmacology, University Medical Center Göttingen, Göttingen, Germany.,Department of Bioengineering, Northeastern University, Boston, Massachusetts, USA.,Department of Physics, Northeastern University, Boston, Massachusetts, USA
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9
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Abstract
OBJECTIVE A frequent observation during cardiac fibrillation is a fluctuation in complexity where the irregular pattern of the fibrillation is interrupted by more regular phases of varying length. APPROACH We apply different measures to sliding windows of raw ECG signals for quantifying the temporal complexity. The methods include permutation entropy, power spectral entropy, a measure for the extent of the set of reconstructed states and several wavelet measures. MAIN RESULTS Using these methods, variations of fibrillation patterns over time are detected and visualized. SIGNIFICANCE These quantifications can be used to characterize different phases of the ECG during fibrillation and might improve diagnosis and treatment methods for heart diseases.
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Affiliation(s)
- A Schlemmer
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, German. Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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Barrett B, Bulat T, Schultz S, Luther S. MORTALITY AND ASSOCIATED RISK FACTORS IN COMMUNITY-DWELLING PERSONS WITH EARLY DEMENTIA. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.4440] [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: 11/13/2022] Open
Affiliation(s)
- B. Barrett
- HSR&D Center of Innovation on Disability and Rehabilitation Research, Department of Veterans Affairs, Tampa, Florida,
- Patient Safety Center of Inquiry, Department of Veterans Affairs, Tampa, Florida
| | - T. Bulat
- HSR&D Center of Innovation on Disability and Rehabilitation Research, Department of Veterans Affairs, Tampa, Florida,
- Patient Safety Center of Inquiry, Department of Veterans Affairs, Tampa, Florida
| | - S.K. Schultz
- HSR&D Center of Innovation on Disability and Rehabilitation Research, Department of Veterans Affairs, Tampa, Florida,
| | - S. Luther
- HSR&D Center of Innovation on Disability and Rehabilitation Research, Department of Veterans Affairs, Tampa, Florida,
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11
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Boccia E, Luther S, Parlitz U. Modelling far field pacing for terminating spiral waves pinned to ischaemic heterogeneities in cardiac tissue. Philos Trans A Math Phys Eng Sci 2017; 375:rsta.2016.0289. [PMID: 28507234 PMCID: PMC5434080 DOI: 10.1098/rsta.2016.0289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 05/24/2023]
Abstract
In cardiac tissue, electrical spiral waves pinned to a heterogeneity can be unpinned (and eventually terminated) using electric far field pulses and recruiting the heterogeneity as a virtual electrode. While for isotropic media the process of unpinning is much better understood, the case of an anisotropic substrate with different conductivities in different directions still needs intensive investigation. To study the impact of anisotropy on the unpinning process, we present numerical simulations based on the bidomain formulation of the phase I of the Luo and Rudy action potential model modified due to the occurrence of acute myocardial ischaemia. Simulating a rotating spiral wave pinned to an ischaemic heterogeneity, we compare the success of sequences of far field pulses in the isotropic and the anisotropic case for spirals still in transient or in steady rotation states. Our results clearly indicate that the range of pacing parameters resulting in successful termination of pinned spiral waves is larger in anisotropic tissue than in an isotropic medium.This article is part of the themed issue 'Mathematical methods in medicine: neuroscience, cardiology and pathology'.
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Affiliation(s)
- E Boccia
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
- Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- Institute of Pharmacology and Toxicology, University Medical Center, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
- Department of Bioengineering, Northeastern University, 360 Huntington Avenue, Boston MA 02115, USA
- Department of Physics, Northeastern University, 360 Huntington Avenue, Boston MA 02115, USA
| | - U Parlitz
- Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, 37077 Göttingen, Germany
- Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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12
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Hood T, Luther S, Verma A, Lawson T, Pease M, Ring J, Der K, Schnitzler A, Rook M, Murrell J. Manufacturing solutions for mesenchymal stromal/stem cell therapy expansion. Cytotherapy 2017. [DOI: 10.1016/j.jcyt.2017.02.122] [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: 10/19/2022]
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13
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Hornung D, Biktashev VN, Otani NF, Shajahan TK, Baig T, Berg S, Han S, Krinsky VI, Luther S. Mechanisms of vortices termination in the cardiac muscle. R Soc Open Sci 2017; 4:170024. [PMID: 28405398 PMCID: PMC5383855 DOI: 10.1098/rsos.170024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/14/2017] [Indexed: 06/07/2023]
Abstract
We propose a solution to a long-standing problem: how to terminate multiple vortices in the heart, when the locations of their cores and their critical time windows are unknown. We scan the phases of all pinned vortices in parallel with electric field pulses (E-pulses). We specify a condition on pacing parameters that guarantees termination of one vortex. For more than one vortex with significantly different frequencies, the success of scanning depends on chance, and all vortices are terminated with a success rate of less than one. We found that a similar mechanism terminates also a free (not pinned) vortex. A series of about 500 experiments with termination of ventricular fibrillation by E-pulses in pig isolated hearts is evidence that pinned vortices, hidden from direct observation, are significant in fibrillation. These results form a physical basis needed for the creation of new effective low energy defibrillation methods based on the termination of vortices underlying fibrillation.
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Affiliation(s)
- D. Hornung
- Max Planck Institute DS, BMPG, Gottingen, Germany
| | | | - N. F. Otani
- Rochester Institute of Technology, Rochester, NY, USA
| | - T. K. Shajahan
- National Institute of Technology Karnataka, Bangalore, India
| | - T. Baig
- Max Planck Institute DS, BMPG, Gottingen, Germany
- Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen
| | - S. Berg
- Max Planck Institute DS, BMPG, Gottingen, Germany
- Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen
| | - S. Han
- Rochester Institute of Technology, Rochester, NY, USA
| | - V. I. Krinsky
- Max Planck Institute DS, BMPG, Gottingen, Germany
- INLN, CNRS, Valbonne, France
| | - S. Luther
- Max Planck Institute DS, BMPG, Gottingen, Germany
- Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen
- Department of Pharmacology, University Medical Centre Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
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14
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Schumann-Bischoff J, Luther S, Parlitz U. Estimability and dependency analysis of model parameters based on delay coordinates. Phys Rev E 2016; 94:032221. [PMID: 27739730 DOI: 10.1103/physreve.94.032221] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Indexed: 06/06/2023]
Abstract
In data-driven system identification, values of parameters and not observed variables of a given model of a dynamical system are estimated from measured time series. We address the question of estimability and redundancy of parameters and variables, that is, whether unique results can be expected for the estimates or whether, for example, different combinations of parameter values would provide the same measured output. This question is answered by analyzing the null space of the linearized delay coordinates map. Examples with zero-dimensional, one-dimensional, and two-dimensional null spaces are presented employing the Hindmarsh-Rose model, the Colpitts oscillator, and the Rössler system.
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Affiliation(s)
- J Schumann-Bischoff
- Biomedical Physics Group, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany and Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen, Germany
| | - S Luther
- Biomedical Physics Group, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany and Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen, Germany
| | - U Parlitz
- Biomedical Physics Group, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077 Göttingen, Germany and Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, 37077 Göttingen, Germany
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Rook M, Heron A, Verma A, Luther S, Lawson T, Aysola M, Hood T, Schnitzler A, Murrell J. Transitioning to Xeno-Free and Chemically Defined Media Platforms for Mesenchymal Stem Cell Manufacturing. Cytotherapy 2016. [DOI: 10.1016/j.jcyt.2016.03.282] [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: 11/16/2022]
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16
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Rother J, Richter C, Turco L, Knoch F, Mey I, Luther S, Janshoff A, Bodenschatz E, Tarantola M. Crosstalk of cardiomyocytes and fibroblasts in co-cultures. Open Biol 2016; 5:150038. [PMID: 26085516 PMCID: PMC4632504 DOI: 10.1098/rsob.150038] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Electromechanical function of cardiac muscle depends critically on the crosstalk of myocytes with non-myocytes. Upon cardiac fibrosis, fibroblasts translocate into infarcted necrotic tissue and alter their communication capabilities. In the present in vitro study, we determined a multiple parameter space relevant for fibrotic cardiac tissue development comprising the following essential processes: (i) adhesion to substrates with varying elasticity, (ii) dynamics of contractile function, and (iii) electromechanical connectivity. By combining electric cell-substrate impedance sensing (ECIS) with conventional optical microscopy, we could measure the impact of fibroblast–cardiomyocyte ratio on the aforementioned parameters in a non-invasive fashion. Adhesion to electrodes was quantified via spreading rates derived from impedance changes, period analysis allowed us to measure contraction dynamics and modulations of the barrier resistance served as a measure of connectivity. In summary, we claim that: (i) a preferred window for substrate elasticity around 7 kPa for low fibroblast content exists, which is shifted to stiffer substrates with increasing fibroblast fractions. (ii) Beat frequency decreases nonlinearly with increasing fraction of fibroblasts, while (iii) the intercellular resistance increases with a maximal functional connectivity at 75% fibroblasts. For the first time, cardiac cell–cell junction density-dependent connectivity in co-cultures of cardiomyocytes and fibroblasts was quantified using ECIS.
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Affiliation(s)
- J Rother
- Institute of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Goettingen 37077, Germany
| | - C Richter
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Fassberg 17, Goettingen 37077, Germany Heart Research Center Goettingen, Robert-Koch-Strasse 40, Goettingen 37099, Germany
| | - L Turco
- Laboratory for Fluid Dynamics, Pattern Formation and Biocomplexity, Am Fassberg 17, Goettingen 37077, Germany
| | - F Knoch
- Laboratory for Fluid Dynamics, Pattern Formation and Biocomplexity, Am Fassberg 17, Goettingen 37077, Germany
| | - I Mey
- Institute of Organic and Biomolecular Chemistry, Georg-August University, Tammannstrasse 6, Goettingen 37077, Germany
| | - S Luther
- Research Group Biomedical Physics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Fassberg 17, Goettingen 37077, Germany German Center for Cardiovascular Research (DZHK), Oudenarder Strasse 16, Berlin 13347, Germany Heart Research Center Goettingen, Robert-Koch-Strasse 40, Goettingen 37099, Germany Institute of Nonlinear Dynamics, Georg-August University, Friedrich-Hund-Platz 1, Goettingen 37077, Germany
| | - A Janshoff
- Institute of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Goettingen 37077, Germany
| | - E Bodenschatz
- Laboratory for Fluid Dynamics, Pattern Formation and Biocomplexity, Am Fassberg 17, Goettingen 37077, Germany German Center for Cardiovascular Research (DZHK), Oudenarder Strasse 16, Berlin 13347, Germany Heart Research Center Goettingen, Robert-Koch-Strasse 40, Goettingen 37099, Germany Institute of Nonlinear Dynamics, Georg-August University, Friedrich-Hund-Platz 1, Goettingen 37077, Germany
| | - M Tarantola
- Laboratory for Fluid Dynamics, Pattern Formation and Biocomplexity, Am Fassberg 17, Goettingen 37077, Germany
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Nayar S, Campos J, Cloake T, Bowman S, Bombardieri M, Pitzalis C, Luther S, Buckley C, Barone F. SAT0005 IL22 Regulates Autoantibody Production by Inducing Lymphoid Chemokine Expression in Tertiary Lymphoid Organs. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.5049] [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: 11/03/2022]
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Schlemmer A, Parlitz U, Luther S, Wessel N, Penzel T. Changes of sleep-stage transitions due to ageing and sleep disorder. Philos Trans A Math Phys Eng Sci 2015; 373:rsta.2014.0093. [PMID: 25548271 DOI: 10.1098/rsta.2014.0093] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Transition patterns between different sleep stages are analysed in terms of probability distributions of symbolic sequences for young and old subjects with and without sleep disorder. Changes of these patterns due to ageing are compared with variations of transition probabilities due to sleep disorder.
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Affiliation(s)
- A Schlemmer
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, Göttingen 37077, Germany Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, Göttingen 37077, Germany
| | - U Parlitz
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, Göttingen 37077, Germany Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, Göttingen 37077, Germany
| | - S Luther
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, Göttingen 37077, Germany Institute for Nonlinear Dynamics, Georg-August-Universität Göttingen, Am Faßberg 17, Göttingen 37077, Germany
| | - N Wessel
- Department of Physics, Humboldt-Universität zu Berlin, Robert-Koch-Platz 4, Berlin 10115, Germany
| | - T Penzel
- Department of Physics, Humboldt-Universität zu Berlin, Robert-Koch-Platz 4, Berlin 10115, Germany Sleep Medicine Center, Charité Universitätsmedizin Berlin, Chariteplatz 1, Berlin 10117, Germany
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Lehnart SE, Wagner E, Kohl T, Westphal V, Parlitz U, Luther S, Hell SW, Jafri MS, Lederer WJ. Proliferative membrane changes of T-tubules and cell-wide network changes during cardiac remodeling with orphaning of Ca2+ release sites are a general mechanism of heart failure. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht307.34] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Borchers S, Weissinger E, Pabst B, Ganzenmueller T, Dammann E, Luther S, Diedrich H, Ganser A, Stadler M. Expansion of recipient-derived antiviral T cells may influence donor chimerism after allogeneic stem cell transplantation. Transpl Infect Dis 2013; 15:627-33. [DOI: 10.1111/tid.12101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 11/13/2012] [Accepted: 12/23/2012] [Indexed: 11/29/2022]
Affiliation(s)
- S. Borchers
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - E.M. Weissinger
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - B. Pabst
- Department of Human Genetics; Hannover Medical School; Hannover Germany
| | - T. Ganzenmueller
- Department of Virology; Hannover Medical School; Hannover Germany
| | - E. Dammann
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - S. Luther
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - H. Diedrich
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - A. Ganser
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
| | - M. Stadler
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation; Hannover Medical School (MHH); Hannover Germany
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Abstract
Abstract
Calender units with rotating rolls are used to produce foils or sheets from polymer material with viscous or elastomeric flow properties. Up to now, the design process of calender units, the calculation of flow and pressure fields in the calender gap and the calculation of resulting deformations of the rotating rolls are implemented with different computer programs. In this work a design concept that integrates design and calculation programs is being developed in order to achieve integrated design and calculation. With this concept, it is possible to design calenders and calculate flow fields and deformations. After designing the rolls with the Computer Aided Design program Pro/Engineer, the flow field in the calender gap is calculated with the Finite Volume Method program CFX4, and the deformation of the rolls is calculated with the Finite Element Method program ANSYS. The iterative process of design, calculation and modification of shape is continued until sheets or foils of constant thickness leave the calender gap. The design concept has an object-oriented operational structure. The data transfer between the programs takes place via a central data base in STEP format.
As examples, calenders with combinations of solid rolls are designed. The flow field in the calender gap is calculated for Newtonian and for viscoelastic fluids with use of an integral rheological equation of state. The flow field is compared to a measured flow field. The resulting deformations of the rolls are calculated and represented graphically. Furthermore, a design process for elastomer-coated rolls is implemented and their deformations as well as the interior stress fields are calculated.
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Affiliation(s)
- D. Mewes
- Institut für Verfahrenstechnik, Universität Hannover, Germany
| | - S. Luther
- Institut für Verfahrenstechnik, Universität Hannover, Germany
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Wagner E, Kohl T, Tuan HTM, Westphal V, Parlitz U, Luther S, Hell SW, Jafri MS, Lederer WJ, Lehnart SE. Best Basic Science abstract. Europace 2013. [DOI: 10.1093/europace/eut179] [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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Nayar S, Cloake T, Lane P, Pitzalis C, Coles M, Luther S, Buckley C, Barone F. OP0258 IL-22 Regulates Lymphoid Stromal Cell Expansion, Development of Germinal Centers and Humoral Response in Mucosal Ectopic Lymphoneogenesis. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2013-eular.463] [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: 11/04/2022]
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Parlitz U, Berg S, Luther S, Schirdewan A, Kurths J, Wessel N. Classifying cardiac biosignals using ordinal pattern statistics and symbolic dynamics. Comput Biol Med 2012; 42:319-27. [DOI: 10.1016/j.compbiomed.2011.03.017] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 03/02/2011] [Accepted: 03/28/2011] [Indexed: 11/30/2022]
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Abstract
A basic state and parameter estimation scheme for an extended excitable system is presented, where time series from a spatial grid of sampling points are used to drive and synchronize corresponding model equations. Model parameters are estimated by minimizing the synchronization error. This estimation scheme is demonstrated using data from generic models of excitable media exhibiting spiral wave dynamics and chaotic spiral break-up that are implemented on a graphics processing unit.
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Affiliation(s)
- S Berg
- Drittes Physikalisches Institut, Georg-August-Universität, Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
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Borchers S, Luther S, Lips U, Hahn N, Kontsendorn J, Stadler M, Buchholz S, Diedrich H, Eder M, Koehl U, Ganser A, Mischak-Weissinger E. Tetramer monitoring to assess risk factors for recurrent cytomegalovirus reactivation and reconstitution of antiviral immunity post allogeneic hematopoietic stem cell transplantation. Transpl Infect Dis 2011; 13:222-36. [PMID: 21585633 DOI: 10.1111/j.1399-3062.2011.00626.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Reactivation of cytomegalovirus (CMV) is a major cause of morbidity after allogeneic hematopoietic stem cell transplantation (HSCT). In healthy individuals, virus-specific T cells (CMV-CTL) control the reactivation of latent CMV. The monitoring of virus-epitope-binding CD8(+) T cells using major histocompatibility complex-I-peptide complexes (tetramers) has recently been established, allowing assessment of the reconstitution of CMV-CTL post HSCT. PATIENTS AND METHODS In order to study immune reconstitution and reactivation control through CMV-CTL, we regularly monitored all patients undergoing allogeneic HSCT in our department for 2 years, who matched at least 1 of 6 commercially available tetramers for common human leukocyte antigen (HLA) types. To verify risk factors for CMV reactivations in our cohorts, clinical characteristics of all patients transplanted within the last 10 years were included in statistical analyses determining the relative risk for single and recurrent CMV reactivations. RESULTS As expected, CMV serostatus, HLA match, and donor source significantly influenced the risk of recurrent CMV reactivation. Applying CMV-CTL tetramer monitoring for 2 years allowed the monitoring of 114 (85%) of 134 patients, by testing a set of tetramers representing 6 epitopes from 3 different CMV proteins. The presence of CMV-CTL before day + 50 and their expansion post reactivation seem to protect against recurrent CMV reactivations. The mean number of CMV-CTL by day +100 was >5-fold higher in the recipient CMV-positive/donor-positive (R +/D +) group (91/μL) compared with the R +/ D- (13/μL) and the R -/D +(2/μL) group. Seventy-nine percent of patients from the R +/D + setting recovered >10 CMV-CTL per μL by day + 100, while almost 50% of the other groups failed to mount a CMV-specific response by that time (R +/D -: 58%; R -/D +: 43%). CONCLUSION Tetramer monitoring can help to predict (recurrent) CMV reactivation and is a useful approach to monitor individual patients with increased risk for recurrent reactivation post HSCT; thus, it could help to identify patients in need of adoptive transfer of CMV-CTL or to optimize the use of antiviral drugs.
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Affiliation(s)
- S Borchers
- Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
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Matsen C, Luther S, Stewart A, Henderson W, Neumayer L. A Match Made In Heaven? Trying To Combine NSQIP And NCDB Databases. J Surg Res 2011. [DOI: 10.1016/j.jss.2010.11.254] [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: 10/18/2022]
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Becker W, Kaiser B, Luther S, Otremba H. Feuchteschäden in Wohnräumen: gesundheitliche, umweltbezogene und soziale Aspekte – Kleinräumige Erhebung aus dem Gesundheitsamt Bremen. Gesundheitswesen 2008; 70:636-9. [DOI: 10.1055/s-0028-1100393] [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: 10/21/2022]
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Wieczorek A, Hernandez-Robles J, Ewing L, Leshko J, Luther S, Huhta J. Prediction of outcome of fetal congenital heart disease using a cardiovascular profile score. Ultrasound Obstet Gynecol 2008; 31:284-288. [PMID: 18253925 DOI: 10.1002/uog.5177] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
OBJECTIVES Congestive heart failure in fetuses with congenital heart defects (CHD) is associated with high perinatal mortality. The clinical condition can be characterized by five ultrasound markers that comprise the 10-point cardiovascular profile (CVP) score. Our aim was to assess the value of the CVP score in evaluating the condition and in maintaining surveillance of fetuses with CHD. METHODS We evaluated retrospectively 131 singleton pregnancies with a diagnosis of fetal CHD, which had been assessed by serial echocardiographic examinations, during which the CVP score was obtained. Fetal and neonatal outcomes, including perinatal mortality and Apgar scores, were assessed. RESULTS Fetuses with a final CVP score <or= 7 were statistically significantly more likely to suffer mortality than were fetuses with a final CVP score >or= 8 (87.5% vs. 15.2% mortality; P < 0.0001, chi square = 24.5). Significance was maintained after controlling for birth weight, lag time between the final examination and delivery and the dichotomized 5-min Apgar score (odds ratio, 22.3; P = 0.024). For low Apgar score and mortality, the CVP score had low sensitivity (0.25 and 0.27, respectively) but high specificity (0.98 and 0.99, respectively). The presence of hydrops and severe cardiomegaly were statistically significantly associated with mortality (P < 0.05). CONCLUSIONS Fetuses with CHD and a CVP score below 8 are at risk of perinatal death. The CVP score may be used to assess the severity of fetal CHD and to plan perinatal management.
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Affiliation(s)
- A Wieczorek
- Department of Pediatrics, University of South Florida College of Medicine, Tampa, FL 33701, USA
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Haiduven D, Cooper E, Luther S. Comparison of live versus online bioreadiness training programs for nurses. Am J Infect Control 2005. [DOI: 10.1016/j.ajic.2005.04.055] [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: 11/25/2022]
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Hassaballa H, Luther S, Bloom KJ, Prinz RA. Systemic calciphylaxis in a patient with end-stage renal disease and a normal parathyroid hormone level taking erythropoietin intramuscularly. Endocr Pract 2004; 5:46-50. [PMID: 15251703 DOI: 10.4158/ep.5.1.46] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To describe a patient with systemic calciphylaxis. METHODS We present a case of a 26-year-old woman with end-stage renal disease taking intramuscular injections of erythropoietin in whom systemic calciphylaxis subsequently developed. Both clinical and laboratory findings are reviewed. RESULTS In a 26-year-old woman with end-stage renal disease who was taking erythropoietin intramuscularly, multiple, superficial ulcerative lesions developed on both lower extremities. Despite aggressive treatment, new lesions subsequently developed. Laboratory values showed an increased calcium-phosphate product and a normal parathyroid hormone level. A skin biopsy specimen showed necrotic skin and subcutaneous fat with foci of calcification around the vessels, findings that confirmed the diagnosis of calciphylaxis. The patient then underwent subtotal parathyroidectomy and responded with initial improvement; however, her condition later deteriorated, and she died of uncontrolled pulmonary hemorrhage. CONCLUSION Systemic calciphylaxis is a rare but devastating complication of end-stage renal disease. This condition mimics many different disorders; therefore, a high index of suspicion is essential for early recognition and diagnosis, which is assisted by biopsy specimens of skin lesions. Treatment includes subtotal or total parathyroidectomy in conjunction with autotransplantation, administration of phosphate binders, aggressive treatment with antibiotics, and lowering of the calcium-phosphate product. Even though a successful outcome is possible when this disease is recognized early and treated aggressively, the morbidity and mortality associated with systemic calciphylaxis still remain high.
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Affiliation(s)
- H Hassaballa
- Rush Medical College, Rush University, Chicago, Illinois, USA
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Tiede A, Eder M, von Depka M, Battmer K, Luther S, Kiem HP, Ganser A, Scherr M. Recombinant factor VIII expression in hematopoietic cells following lentiviral transduction. Gene Ther 2003; 10:1917-25. [PMID: 14502221 DOI: 10.1038/sj.gt.3302093] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [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: 11/08/2022]
Abstract
Autologous transplantation of gene-modified hematopoietic stem cells may provide a therapeutic strategy for several monogeneic disorders. In previous studies, retroviral gene transfer of coagulation factor VIII (FVIII) into FVIII(-/-) mouse bone marrow (BM) cells did not result in detectable plasma FVIII levels. However, specific immune tolerance was achieved against neo-antigenic FVIII. Here, we used lentiviral vectors to study the ability of various hematopoietic cell types to synthesize and secrete recombinant FVIII. Several myeloid, monocytic and megakaryocytic cell lines (K-562, TF-1, Monomac-1, Mutz-3, Meg-01) expressed FVIII at 2-12 mU/10(4) cells. In contrast, two lymphatic cell lines, BV-173 and Molt-4, were less-efficiently transduced and did not express detectable FVIII. Similarly, peripheral blood-derived primary monocytes were transduced efficiently and expressed up to 20 mU/10(4) cells, whereas primary lymphocytes did not express FVIII. Although human and canine CD34(+) cells were transduced efficiently, the cells expressed very low levels of FVIII (up to 0.8 mU/10(4) cells). Following xenotransplantation of transduced CD34(+) into NOD/SCID mice, ELISA failed to detect FVIII in the plasma of engrafted mice. However, NOD/SCID repopulating cell (SRC)-derived human monocytes isolated from BM of these mice secreted functional recombinant FVIII after culture ex vivo. Again, SRC-derived human lymphocytes did not secrete FVIII. Therefore, certain hematopoietic cell types are able to synthesize and secrete functional recombinant FVIII. Our results show for the first time that transplantation of transduced CD34(+) progenitors may give rise to differentiated hematopoietic cells secreting a nonhematopoietic recombinant protein.
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Affiliation(s)
- A Tiede
- Department of Hematology and Oncology, Hannover Medical School, Hannover, Germany
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Luther S, Mewes D. Untersuchung des Kalandrierprozesses mit Hilfe der Berechnung von Strömungsfeldern. CHEM-ING-TECH 2003. [DOI: 10.1002/cite.200390366] [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: 11/09/2022]
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Kittel R, Bittmann F, Badtke G, Luther S. Objektivierte Beurteilung der aktiven zyklischen Halswirbelsäulenrotation bei Funktionsstörungen. Manuelle Medizin 2002. [DOI: 10.1007/s00337-002-0154-3] [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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Abstract
Acoustically induced cavitation at 20 kHz is observed by means of high speed CCD recording at a frame-rate of 2250 per second. Using digital image processing the bubbles' trajectories are reconstructed. The experimental data reveal that collision and coalescence of bubbles is a predominant phenomenon that limits their individual lifetime. Measurements of bubble sizes and velocities are in agreement with previous results.
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Affiliation(s)
- S Luther
- Drittes Physikalisches Institut, Universität Göttingen, Bürgerstrasse 42-44, D-37073 Göttingen, Germany.
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Tatlidil R, Luther S, West A, Jadvar H, Kingman T. Comparison of fluorine-18 deoxyglucose and O-15 water PET in temporal lobe epilepsy. Acta Neurol Belg 2000; 100:214-20. [PMID: 11233675] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
This study reports a comparison of Fluorine-18 deoxyglucose positron emission tomography (FDG-PET) and O-15 water (H2(15)O) PET with regard to lateralization of the seizure focus in patients with complex partial epilepsy. The analysis of 35 patients who had an anterior temporal lobectomy for medically intractable seizures indicated that FDG- and H2(15)O-PET were highly correlated in demonstrating the epileptic focus. FDG- and H2(15)O-PET showed significant asymmetries in 83% and 77% of cases respectively. The lateralization with visual analysis of MRI was found to be lower than both FDG and blood flow imaging. Ictal electroencephalography (EEG) lateralizations were concordant with sites of blood flow and FDG-PET abnormalities. Thirty-three patients (94%) were seizure-free or improved significantly after surgery. In conclusion, blood flow PET yielded similar results compared to FDG-PET and can be a valuable modality in preoperative evaluation of patients with temporal lobe epilepsy.
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Affiliation(s)
- R Tatlidil
- Research Imaging Center and Division of Neurosurgery, University of Texas Health Science Center, San Antonio, USA
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Abstract
OBJECTIVES The purpose of this study was to assess the value of same day blood flow PET in both the identification of the language dominant hemisphere and in the lateralization of the epileptic focus in patients who were preoperatively evaluated for complex partial seizures. METHODS The charts of 24 patients who had temporal lobectomies for seizures were retrospectively reviewed. All PET scans were acquired by using O-15 water tracer (H2(15)O) in both resting and language activation conditions. PET language laterality results were compared to Intracarotid amytal procedure (IAP) results. For epileptic focus lateralizations, regions of interest (ROI) analysis of temporal lobes was performed on resting scans. RESULTS IAP testing was discordant with PET language mapping in 1 out of 24 cases. This patient had a decline in cognitive abilities as measured by postoperative neuropsychologic testing. For epileptic focus lateralization, the PET was highly sensitive (87%) and specific (100%). Lateralizations with the PET were in agreement with surgical sites in all cases. Eighteen patients (75%) were seizure free and 4 patients (17%) were significantly improved after surgery. CONCLUSION The results suggest that O-15 water PET is sensitive and specific in both the lateralization of epileptic focus and the language dominant hemisphere and can be a cost-effective and noninvasive method in presurgical evaluation of patients with complex partial seizures.
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Affiliation(s)
- R Tatlidil
- Research Imaging Center, University of Texas Health Science Center in San Antonio, USA
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Rosenbaum D, Luther S, Krist A. Is a 7-day course of ciprofloxacin effective in the treatment of uncomplicated pyelonephritis in women? J Fam Pract 2000; 49:573-574. [PMID: 10923561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- D Rosenbaum
- Fairfax Family Practice Residency, Virginia, USA.
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Luther S, Bittmann F, Böhme C, Wanagas T. [Stretch and relaxation training with isokinetic training apparatus]. Sportverletz Sportschaden 2000; 14:M11-6. [PMID: 10859787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- S Luther
- Institut für Sportmedizin und Prävention Universität Potsdam.
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Kafert S, Luther S, Böll I, Wagner K, Ganser A, Eder M. Functional analysis of a single chain chimeric alpha/beta-granulocyte-macrophage colony-stimulating factor receptor. Importance of a glutamate residue in the transmembrane region. J Biol Chem 1999; 274:33064-71. [PMID: 10551876 DOI: 10.1074/jbc.274.46.33064] [Citation(s) in RCA: 6] [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: 11/06/2022] Open
Abstract
To analyze the function of each subunit of the receptor for granulocyte-macrophage colony-stimulating factor (GM-CSF), GMR, we previously generated a single-chain chimeric receptor by fusion of the extracellular and transmembrane domain from the alpha-subunit (alpha-GMR) to the intracellular part of the beta-subunit (beta-GMR) introducing an additional glutamate residue at the fusion site (alpha/beta-GMR). We demonstrated the capacity of alpha/beta-GMR to bind GM-CSF with low affinity and to induce GM-CSF-dependent activation of tyrosine kinase activity and proliferation in transfected Ba/F3 cells. To further compare the functions of wild type and chimeric receptors, we now report that this alpha/beta-GMR is sufficient to mediate morphological changes, expression of alpha(4)- and beta(1)-integrin receptor subunits, and serine-phosphorylation of Akt kinase. To analyze the function of the glutamate residue at the fusion region of alpha/beta-GMR various point mutants changing this amino acid and its position were expressed in Ba/F3 cells. None of these mutants was capable of supporting GM-CSF-dependent proliferation; however, when beta-GMR was coexpressed, GM-CSF mediated short and long term proliferation. Interestingly, some mutants but not alpha/beta-GMR can induce proliferation in the presence of an anti-alpha-GMR antibody. These data demonstrate the significance of a glutamate residue in the transmembrane region of alpha/beta-GMR for ligand-induced receptor activation.
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Affiliation(s)
- S Kafert
- Department of Hematology, Hannover Medical School, D-30625 Hannover, Germany
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McCloskey MA, Fan Y, Luther S. Chemotaxis of rat mast cells toward adenine nucleotides. J Immunol 1999; 163:970-7. [PMID: 10395694] [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] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Rat mucosal mast cells express P2 purinoceptors, occupation of which mobilizes cytosolic Ca2+ and activates a potassium conductance. The primary function of this P2 system in mast cell biology remains unknown. Here, we show that extracellular ADP causes morphological changes in rat bone marrow-cultured mast cells (BMMC) typical of those occurring in cells stimulated by chemotaxins, and that the nucleotides ADP, ATP, and UTP are effective chemoattractants for rat BMMC. ADP was also a chemotaxin for murine J774 monocytes. The nucleotide selectivity and pertussis toxin sensitivity of the rat BMMC migratory response suggest the involvement of P2U receptors. Poorly hydrolyzable derivatives of ADP and ATP were effective chemotaxins, obviating a role for adenosine receptors. Buffering of external Ca2+ at 100 nM or reduction of the electrical gradient driving Ca2+ entry (by elevating external K+) blocked ADP-driven chemotaxis, suggesting a role for Ca2+ influx in this process. Anaphylatoxin C5a was a potent chemotaxin (EC50 approximately 0.5 nM) for J774 monocytes, but it was inactive on rat BMMC in the presence or absence of laminin. Ca2+ removal or elevated [K+] had modest effects on C5a-driven chemotaxis of J774 cells, implicating markedly different requirements for Ca2+ signaling in C5a- vs ADP-mediated chemotaxis. This is supported by the observation that depletion of Ca2+ stores with thapsigargin completely blocked migration induced by ADP but not C5a. These findings suggest that adenine nucleotides liberated from parasite-infested tissue could participate in the recruitment of mast cells by intestinal mucosa.
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Affiliation(s)
- M A McCloskey
- Department of Zoology and Genetics, Iowa State University, Ames 50011, USA.
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Bittmann F, Luther S, Wanagas T, Kittel R. [Objective evaluation of muscular elasticity using routine general practice isokinetic test systems]. Sportverletz Sportschaden 1999; 13:M24-8. [PMID: 10478386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Affiliation(s)
- F Bittmann
- Institut für Sportmedizin und Prävention Universität Potsdam
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Abstract
Cavitation bubbles in acoustic resonators are observed to arrange in branch-like patterns. We give a brief review of the anatomy of such structures and outline an approach for simulation by individual, moving bubbles. This particle model can reproduce an experimentally observed transition between different structure types in a rectangular resonator cell.
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Affiliation(s)
- R Mettin
- Drittes Physikalisches Institut, Universität Göttingen, Germany.
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Ardavín C, Martín P, Ferrero I, Azcoitia I, Anjuère F, Diggelmann H, Luthi F, Luther S, Acha-Orbea H. B cell response after MMTV infection: extrafollicular plasmablasts represent the main infected population and can transmit viral infection. J Immunol 1999; 162:2538-45. [PMID: 10072493] [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: 02/11/2023]
Abstract
The immune response to mouse mammary tumor virus (MMTV) relies on the presentation of an MMTV-encoded superantigen by infected B cells to superantigen-specific T cells. The initial extrafollicular B cell differentiation involved the generation of B cells expressing low levels of B220. These B220low B cells corresponded to plasmablasts that expressed high levels of CD43 and syndecan-1 and were CD62 ligand- and IgD-. Viral DNA was detected nearly exclusively in these B220low B cells by PCR, and retroviral type-A particles were observed in their cytoplasm by electron microscopy. An MMTV transmission to the offspring was also achieved after transfer of B220low CD62 ligand- CD43+ plasmablasts into noninfected females. These data suggest that B220low plasmablasts, representing the bulk of infected B cells, are capable of sustaining viral replication and may be involved in the transmission of MMTV.
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Affiliation(s)
- C Ardavín
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland
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Schikora D, Widmer T, Lischka K, Schäfer P, Machel G, Luther S. Structural and physical properties of mercury-iron selenide layers and quantum wells. Phys Rev B Condens Matter 1995; 52:12072-12080. [PMID: 9980348 DOI: 10.1103/physrevb.52.12072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Luther S, Shakhov AN, Xenarios I, Haga S, Imai S, Acha-Orbea H. New infectious mammary tumor virus superantigen with V beta-specificity identical to staphylococcal enterotoxin B (SEB). Eur J Immunol 1994; 24:1757-64. [PMID: 8056034 DOI: 10.1002/eji.1830240806] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [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: 01/28/2023]
Abstract
Only few infectious mouse mammary tumor viruses (MMTV) have been characterized which induce a potent superantigen response in vivo. Here we describe the characterization of an MMTV which was isolated from milk of the highly mammary tumor-prone SHN mouse strain. Exposure of newborn mice to milk-borne MMTV (SHN) results in a very slow deletion of V beta 7, 8.1, 8.2 and 8.3 expressing peripheral T cells. Subcutaneous injection of adult mice with this virus induces a rapid and strong stimulation of all four affected V beta-subsets in vivo. Besides the strong T cell effect we observed an early proliferation and activation of the local B cell pool leading to the initial secretion of IgM followed by preferential secretion of IgG2a by day 6. Sequence comparison of the polymorphic C terminus with known open reading frames revealed high homology to the endogenous provirus Mtv-RCS. This is the first report of a virus having a complete overlap in V beta-specificity with a bacterial superantigen stimulating as many as 35% of the whole CD4+ T cell repertoire including V beta 8.2.
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Affiliation(s)
- S Luther
- Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland
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Marshburn J, Bradham DD, Studnicki J, Nemec L, Luther S, Clark RA. Mass mammography screening: using an information system to track participation and identify target populations. Cancer Pract 1994; 2:146-53. [PMID: 8055016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This article describes the 1991 American Cancer Society Greater Tampa Bay Breast Screening Program and an information system developed to track participants from the point of inquiry to mammography results. Information from three sources was linked to create a comprehensive data base, including participant demographics, mammography history, perceived risks of breast cancer, barriers to mammography, and mammography results. This comprehensive data base allowed investigators to describe the 11,134 participants and to assess the program's impact. The analysis suggested that women older than 65 years are underrepresented in this voluntary program. Black women were less likely to participate, as were women in lower income and education groups. To reduce mortality effectively, leaders of mass screening programs need to develop creative strategies for reaching these high-risk groups. Effective information systems can identify program weaknesses and track the impact of changes.
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Karayiannis P, Saldanha J, Jackson AM, Luther S, Goldin R, Monjardino J, Thomas HC. Partial control of hepatitis delta virus superinfection by immunisation of woodchucks (Marmota monax) with hepatitis delta antigen expressed by a recombinant vaccinia or baculovirus. J Med Virol 1993; 41:210-4. [PMID: 8263503 DOI: 10.1002/jmv.1890410308] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [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] [Indexed: 01/29/2023]
Abstract
We have successfully limited the level of hepatitis delta viraemia occurring after superinfection of hepadna-virus infected woodchucks by prior immunisation with the short form of the hepatitis delta virus antigen expressed by a recombinant baculovirus or vaccinia virus. This phenomenon occurred in the absence of detectable circulating antibody to hepatitis delta virus antigen and in the absence of evidence of priming of the humoral immune response and may reflect the induction of a cytotoxic T-cell response. The latter would control viraemia by rapid lysis of delta antigen expressing hepatocytes. It is suggested that the T-cell epitopes involved may be located on the carboxyl end of the delta protein (amino acids 77-195).
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Affiliation(s)
- P Karayiannis
- Department of Medicine, St. Mary's Hospital Medical School, Imperial College of Science, Technology and Medicine, London, United Kingdom
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