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Stegner M, Lackner B, Schäfernolte T, Buchner O, Xiao N, Gierlinger N, Holzinger A, Neuner G. Winter Nights during Summer Time: Stress Physiological Response to Ice and the Facilitation of Freezing Cytorrhysis by Elastic Cell Wall Components in the Leaves of a Nival Species. Int J Mol Sci 2020; 21:E7042. [PMID: 32987913 PMCID: PMC7582304 DOI: 10.3390/ijms21197042] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/21/2020] [Accepted: 09/21/2020] [Indexed: 01/01/2023] Open
Abstract
Ranunculus glacialis grows and reproduces successfully, although the snow-free time period is short (2-3 months) and night frosts are frequent. At a nival site (3185 m a.s.l.), we disentangled the interplay between the atmospheric temperature, leaf temperatures, and leaf freezing frequency to assess the actual strain. For a comprehensive understanding, the freezing behavior from the whole plant to the leaf and cellular level and its physiological after-effects as well as cell wall chemistry were studied. The atmospheric temperatures did not mirror the leaf temperatures, which could be 9.3 °C lower. Leaf freezing occurred even when the air temperature was above 0 °C. Ice nucleation at on average -2.6 °C started usually independently in each leaf, as the shoot is deep-seated in unfrozen soil. All the mesophyll cells were subjected to freezing cytorrhysis. Huge ice masses formed in the intercellular spaces of the spongy parenchyma. After thawing, photosynthesis was unaffected regardless of whether ice had formed. The cell walls were pectin-rich and triglycerides occurred, particularly in the spongy parenchyma. At high elevations, atmospheric temperatures fail to predict plant freezing. Shoot burial prevents ice spreading, specific tissue architecture enables ice management, and the flexibility of cell walls allows recurrent freezing cytorrhysis. The peculiar patterning of triglycerides close to ice rewards further investigation.
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Affiliation(s)
- Matthias Stegner
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria; (B.L.); (T.S.); (A.H.); (G.N.)
| | - Barbara Lackner
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria; (B.L.); (T.S.); (A.H.); (G.N.)
| | - Tanja Schäfernolte
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria; (B.L.); (T.S.); (A.H.); (G.N.)
| | - Othmar Buchner
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria;
| | - Nannan Xiao
- Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria; (N.X.); (N.G.)
| | - Notburga Gierlinger
- Institute for Biophysics, University of Natural Resources and Life Sciences (BOKU), 1190 Vienna, Austria; (N.X.); (N.G.)
| | - Andreas Holzinger
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria; (B.L.); (T.S.); (A.H.); (G.N.)
| | - Gilbert Neuner
- Department of Botany, University of Innsbruck, 6020 Innsbruck, Austria; (B.L.); (T.S.); (A.H.); (G.N.)
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Derler I, Jardin I, Stathopulos PB, Muik M, Fahrner M, Zayats V, Pandey SK, Poteser M, Lackner B, Absolonova M, Schindl R, Groschner K, Ettrich R, Ikura M, Romanin C. Cholesterol modulates Orai1 channel function. Sci Signal 2016; 9:ra10. [PMID: 26814231 DOI: 10.1126/scisignal.aad7808] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
STIM1 (stromal interaction molecule 1) and Orai proteins are the essential components of Ca(2+) release-activated Ca(2+) (CRAC) channels. We focused on the role of cholesterol in the regulation of STIM1-mediated Orai1 currents. Chemically induced cholesterol depletion enhanced store-operated Ca(2+) entry (SOCE) and Orai1 currents. Furthermore, cholesterol depletion in mucosal-type mast cells augmented endogenous CRAC currents, which were associated with increased degranulation, a process that requires calcium influx. Single point mutations in the Orai1 amino terminus that would be expected to abolish cholesterol binding enhanced SOCE to a similar extent as did cholesterol depletion. The increase in Orai1 activity in cells expressing these cholesterol-binding-deficient mutants occurred without affecting the amount in the plasma membrane or the coupling of STIM1 to Orai1. We detected cholesterol binding to an Orai1 amino-terminal fragment in vitro and to full-length Orai1 in cells. Thus, our data showed that Orai1 senses the amount of cholesterol in the plasma membrane and that the interaction of Orai1 with cholesterol inhibits its activity, thereby limiting SOCE.
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Affiliation(s)
- Isabella Derler
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria.
| | - Isaac Jardin
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Peter B Stathopulos
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Martin Muik
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Marc Fahrner
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Vasilina Zayats
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, CZ-373 33 Nové Hrady, Czech Republic
| | - Saurabh K Pandey
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, CZ-373 33 Nové Hrady, Czech Republic
| | - Michael Poteser
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/4, 8010 Graz, Austria
| | - Barbara Lackner
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Marketa Absolonova
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Rainer Schindl
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Klaus Groschner
- Institute of Biophysics, Medical University of Graz, Harrachgasse 21/4, 8010 Graz, Austria
| | - Rüdiger Ettrich
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, CZ-373 33 Nové Hrady, Czech Republic
| | - Mitsu Ikura
- Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria.
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Frischauf I, Zayats V, Deix M, Hochreiter A, Jardin I, Muik M, Lackner B, Svobodová B, Pammer T, Litviňuková M, Sridhar AA, Derler I, Bogeski I, Romanin C, Ettrich RH, Schindl R. A calcium-accumulating region, CAR, in the channel Orai1 enhances Ca(2+) permeation and SOCE-induced gene transcription. Sci Signal 2015; 8:ra131. [PMID: 26696631 DOI: 10.1126/scisignal.aab1901] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The Ca(2+) release-activated Ca(2+) channel mediates Ca(2+) influx in a plethora of cell types, thereby controlling diverse cellular functions. The channel complex is composed of stromal interaction molecule 1 (STIM1), an endoplasmic reticulum Ca(2+)-sensing protein, and Orai1, a plasma membrane Ca(2+) channel. Channels composed of STIM1 and Orai1 mediate Ca(2+) influx even at low extracellular Ca(2+) concentrations. We investigated whether the activity of Orai1 adapted to different environmental Ca(2+) concentrations. We used homology modeling and molecular dynamics simulations to predict the presence of an extracellular Ca(2+)-accumulating region (CAR) at the pore entrance of Orai1. Furthermore, simulations of Orai1 proteins with mutations in CAR, along with live-cell experiments, or simulations and electrophysiological recordings of the channel with transient, electrostatic loop3 interacting with loop1 (the site of CAR) determined that CAR enhanced Ca(2+) permeation most efficiently at low external Ca(2+) concentrations. Consistent with these results, cells expressing Orai1 CAR mutants exhibited impaired gene expression stimulated by the Ca(2+)-activated transcription factor nuclear factor of activated T cells (NFAT). We propose that the Orai1 channel architecture with a close proximity of CAR to the selectivity filter, which enables Ca(2+)-selective ion permeation, enhances the local extracellular Ca(2+) concentration to maintain Ca(2+)-dependent gene regulation even in environments with relatively low Ca(2+)concentrations.
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Affiliation(s)
- Irene Frischauf
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Vasilina Zayats
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, CZ-373 33, Nove Hrady, Czech Republic.,Faculty of Sciences, University of South Bohemia, Zamek 136, CZ-373 33, Nove Hrady, Czech Republic
| | - Michael Deix
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Anna Hochreiter
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.,Institute for Experimental and Clinical Cell Therapy, Paracelsus Medical University, A-5020 Salzburg, Austria
| | - Isaac Jardin
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Martin Muik
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Barbara Lackner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Barbora Svobodová
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.,Institute for Biophysics of Medical University Graz, A-8010, Graz, Austria
| | - Teresa Pammer
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Monika Litviňuková
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Amrutha Arumbakam Sridhar
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Isabella Derler
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Ivan Bogeski
- Department of Biophysics, School of Medicine, University of Saarland, D-66421 Homburg, Germany
| | - Christoph Romanin
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Rüdiger H Ettrich
- Center for Nanobiology and Structural Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic, Zamek 136, CZ-373 33, Nove Hrady, Czech Republic.,Faculty of Sciences, University of South Bohemia, Zamek 136, CZ-373 33, Nove Hrady, Czech Republic
| | - Rainer Schindl
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
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Derler I, Lackner B, Fahrner M, Stathopulos PB, Jardin I, Bergsmann J, Ikura M, Romanin C. Cholesterol Regulates Orai1 Function. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1834] [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: 10/23/2022] Open
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Nawara C, Rendl G, Wurstbauer K, Lackner B, Rettenbacher L, Datz L, Studnicka M, Sedlmayer F, Pirich C. The impact of PET and PET/CT on treatment planning and prognosis of patients with NSCLC treated with radiation therapy. Q J Nucl Med Mol Imaging 2012; 56:191-201. [PMID: 22402822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AIM 18F fluoro-deoxy-glucose (FDG) positron emission tomography (PET)-imaging improves the diagnostic accuracy in staging non small cell lung cancer (NSCLC) with possible impact on survival. This prospective study aimed to investigate the impact of PET and PET/CT on treatment planning and prognosis in patients with NSCLC treated with radiation therapy. METHODS From October 2003 to January 2008, 91 consecutive patients with proven NSCLC stage T1-4N0-3M0 (clinical stages: I-IIIb) underwent accelerated, twice daily radiation therapy in target splitting technique. 70 patients received chemotherapy before radiation therapy (76%). All patients underwent PET or PET/CT-imaging and were followed up for a median time of 30 months. Imaging findings were interpreted visually and a SUV cut-off of 2.5 was applied for delineation of tumor borders. Changes in staging and planning treatment volumes (PTV) due to PET or PET/CT-imaging and survival were defined as primary study endpoints. The impact of tumor-type, stage, age, gender, weight loss and FDG-uptake in PET imaging as measured by the standardized uptake value (SUV) on survival were analysed as secondary endpoints. RESULTS PET imaging provided additional diagnostic information over CT alone in 20% (N.=18) of our study population, leading to upstaging in 17% of them, respectively. In 5 patients (5.5% of 91) atelectasis could be separated from tumor tissue, PTV was altered in 9% (N.=8). 39 patients (43%) died during the observation period, mean overall survival was 32.3 months (95% Confidence intervalI 27.6-37.1) and tumor specific survival was 36.9 months (95 % CI 32.0-42.0), respectively. One- and two year survival rates reached 90.1% and 67.7%, respectively. Multivariate analysis did not reveal any significant prognostic impact of tumor-type, stage, age, gender or FDG-uptake as given by SUVmax (mean 13.6±6.8) or SUVmean (mean 5.5±1.6). CONCLUSION The use of FDG-PET- and PET/CT-imaging provided incremental information relevant for treatment-planning in about 10 % of patients with NSCLC undergoing accelerated radiation therapy with curative intent. This prospective trial did not provide evidence for the assumption that the SUV might be an independent predictor of outcome.
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Affiliation(s)
- C Nawara
- Department of Nuclear Medicine and Endocrinology, Paracelsus Medical University, Salzburg, Austria
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Muik M, Fahrner M, Schindl R, Stathopulos P, Frischauf I, Derler I, Plenk P, Lackner B, Groschner K, Ikura M, Romanin C. STIM1 couples to ORAI1 via an intramolecular transition into an extended conformation. EMBO J 2011; 30:1678-89. [PMID: 21427704 PMCID: PMC3101990 DOI: 10.1038/emboj.2011.79] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [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: 12/09/2010] [Accepted: 02/25/2011] [Indexed: 12/11/2022] Open
Abstract
Upon depletion of ER calcium stores, STIM1 and ORAI1 associate and induce calcium release-activated calcium (CRAC) currents. This study reveals that STIM1 undergoes an intramolecular transition into an extended conformation that is involved in ORAI1 binding and activation. Stromal interaction molecule (STIM1) and ORAI1 are key components of the Ca2+ release-activated Ca2+ (CRAC) current having an important role in T-cell activation and mast cell degranulation. CRAC channel activation occurs via physical interaction of ORAI1 with STIM1 when endoplasmic reticulum Ca2+ stores are depleted. Here we show, utilizing a novel STIM1-derived Förster resonance energy transfer sensor, that the ORAI1 activating small fragment (OASF) undergoes a C-terminal, intramolecular transition into an extended conformation when activating ORAI1. The C-terminal rearrangement of STIM1 does not require a functional CRAC channel, suggesting interaction with ORAI1 as sufficient for this conformational switch. Extended conformations were also engineered by mutations within the first and third coiled-coil domains in the cytosolic portion of STIM1 revealing the involvement of hydrophobic residues in the intramolecular transition. Corresponding full-length STIM1 mutants exhibited enhanced interaction with ORAI1 inducing constitutive CRAC currents, even in the absence of store depletion. We suggest that these mutant STIM1 proteins imitate a physiological activated state, which mimics the intramolecular transition that occurs in native STIM1 upon store depletion.
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Affiliation(s)
- Martin Muik
- Institute of Biophysics, University of Linz, Linz, Austria
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Madl J, Weghuber J, Fritsch R, Derler I, Fahrner M, Frischauf I, Lackner B, Romanin C, Schütz GJ. Resting-State Orai1 Diffuses as Homotetramer in the Plasma Membrane of Live Mammalian Cells. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Schindl R, Frischauf I, Bergsmann J, Derler I, Fahrner M, Fritsch R, Lackner B, Groschner K, Romanin C. Cooperativeness of Orai Cytosolic Domains Tunes Subtype-Specific Gating. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.1211] [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: 11/27/2022] Open
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9
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Lackner B, Derler I, Fahrner M, Bergsmann J, Frischauf I, Muik M, Schindl R, Groschner K, Romanin C. Orai Coordinates Multiple Regulatory Processes via its N-Terminal Conserved Domain. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.662] [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] Open
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Frischauf I, Schindl R, Bergsmann J, Derler I, Fahrner M, Muik M, Fritsch R, Lackner B, Groschner K, Romanin C. Cooperativeness of Orai cytosolic domains tunes subtype-specific gating. J Biol Chem 2011; 286:8577-8584. [PMID: 21220423 PMCID: PMC3048740 DOI: 10.1074/jbc.m110.187179] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [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] [Indexed: 12/21/2022] Open
Abstract
Activation of immune cells is triggered by the Ca2+ release-activated Ca2+ current, which is mediated via channels of the Orai protein family. A key gating process of the three Orai channel isoforms to prevent Ca2+ overload is fast inactivation, most pronounced in Orai3. A subsequent reactivation is a unique gating characteristic of Orai1 channels, whereas Orai2 and Orai3 currents display a second, slow inactivation phase. Employing a chimeric approach by sequential swapping of respective intra- and extracellular regions between Orai1 and Orai3, we show here that Orai1 specific proline/arginine-rich domains in the N terminus mediate reactivation, whereas the second, intracellular loop modulates fast and slow gating processes. Swapping C-terminal strands lacks a significant impact. However, simultaneous transfer of Orai3 N terminus and its second loop or C terminus in an Orai1 chimera substantially increases fast inactivation centered between wild-type channels. Concomitant swap of all three cytosolic strands from Orai3 onto Orai1 fully conveys Orai3-like gating characteristics, in a strongly cooperative manner. In conclusion, Orai subtype-specific gating requires a cooperative interplay of all three cytosolic domains.
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Affiliation(s)
- Irene Frischauf
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Rainer Schindl
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and.
| | - Judith Bergsmann
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Isabella Derler
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Marc Fahrner
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Martin Muik
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Reinhard Fritsch
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Barbara Lackner
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and
| | - Klaus Groschner
- the Department of Pharmaceutical Sciences-Pharmacology and Toxicology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria
| | - Christoph Romanin
- From the Institute of Biophysics, University of Linz, Altenbergerstrasse 69, 4040 Linz, Austria and.
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Madl J, Weghuber J, Fritsch R, Derler I, Fahrner M, Frischauf I, Lackner B, Romanin C, Schütz GJ. Resting state Orai1 diffuses as homotetramer in the plasma membrane of live mammalian cells. J Biol Chem 2010; 285:41135-42. [PMID: 20961852 PMCID: PMC3003411 DOI: 10.1074/jbc.m110.177881] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 10/05/2010] [Indexed: 01/11/2023] Open
Abstract
Store-operated calcium entry is essential for many signaling processes in nonexcitable cells. The best studied store-operated calcium current is the calcium release-activated calcium (CRAC) current in T-cells and mast cells, with Orai1 representing the essential pore forming subunit. Although it is known that functional CRAC channels in store-depleted cells are composed of four Orai1 subunits, the stoichiometric composition in quiescent cells is still discussed controversially: both a tetrameric and a dimeric stoichiometry of resting state Orai1 have been reported. We obtained here robust and similar FRET values on labeled tandem repeat constructs of Orai1 before and after store depletion, suggesting an unchanged tetrameric stoichiometry. Moreover, we directly visualized the stoichiometry of mobile Orai1 channels in live cells using a new single molecule recording modality that combines single molecule tracking and brightness analysis. By alternating imaging and photobleaching pulses, we recorded trajectories of single, fluorescently labeled Orai1 channels, with each trajectory consisting of bright and dim segments, corresponding to higher and lower numbers of colocalized active GFP label. The according brightness values were used for global fitting and statistical analysis, yielding a tetrameric subunit composition of mobile Orai1 channels in resting cells.
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Affiliation(s)
- Josef Madl
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Julian Weghuber
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Reinhard Fritsch
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Isabella Derler
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Marc Fahrner
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Irene Frischauf
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Barbara Lackner
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Christoph Romanin
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
| | - Gerhard J. Schütz
- From the Biophysics Institute, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria
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Derler I, Lackner B, Bergsmann J, Fahrner M, Groschner K, Romanin C. Positively Charged as Well as Hydrophobic Amino Acids in Orais’ Conserved N-Terminal Domain Contribute to Orai Function. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.3715] [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: 11/28/2022] Open
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13
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Derler I, Fahrner M, Muik M, Lackner B, Schindl R, Groschner K, Romanin C. A Ca2(+ )release-activated Ca2(+) (CRAC) modulatory domain (CMD) within STIM1 mediates fast Ca2(+)-dependent inactivation of ORAI1 channels. J Biol Chem 2009; 284:24933-8. [PMID: 19622747 DOI: 10.1074/jbc.c109.024083] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
STIM1 and ORAI1, the two limiting components in the Ca(2+) release-activated Ca(2+) (CRAC) signaling cascade, have been reported to interact upon store depletion, culminating in CRAC current activation. We have recently identified a modulatory domain between amino acids 474 and 485 in the cytosolic part of STIM1 that comprises 7 negatively charged residues. A STIM1 C-terminal fragment lacking this domain exhibits enhanced interaction with ORAI1 and 2-3-fold higher ORAI1/CRAC current densities. Here we focused on the role of this CRAC modulatory domain (CMD) in the fast inactivation of ORAI1/CRAC channels, utilizing the whole-cell patch clamp technique. STIM1 mutants either with C-terminal deletions including CMD or with 7 alanines replacing the negative amino acids within CMD gave rise to ORAI1 currents that displayed significantly reduced or even abolished inactivation when compared with STIM1 mutants with preserved CMD. Consistent results were obtained with cytosolic C-terminal fragments of STIM1, both in ORAI1-expressing HEK 293 cells and in RBL-2H3 mast cells containing endogenous CRAC channels. Inactivation of the latter, however, was much more pronounced than that of ORAI1. The extent of inactivation of ORAI3 channels, which is also considerably more prominent than that of ORAI1, was also substantially reduced by co-expression of STIM1 constructs missing CMD. Regarding the dependence of inactivation on Ca(2+), a decrease in intracellular Ca(2+) chelator concentrations promoted ORAI1 current fast inactivation, whereas Ba(2+) substitution for extracellular Ca(2+) completely abrogated it. In summary, CMD within the STIM1 cytosolic part provides a negative feedback signal to Ca(2+) entry by triggering fast Ca(2+)-dependent inactivation of ORAI/CRAC channels.
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Affiliation(s)
- Isabella Derler
- Institute of Biophysics, University of Linz, A-4040 Linz, Austria
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Michels S, Prager F, Geitzenauer W, Lackner B, Sacu S, Weigert G, Kriechbaum K, Polak K, Georgopoulos M, Schmidt-Erfurth U. Systemisches und intravitreales Bevacizumab (Avastin®) bei neovaskulärer altersbezogener Makuladegeneration. Spektrum Augenheilkd 2007. [DOI: 10.1007/s00717-007-0203-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Lackner B, Schmidinger G, Funovics M. Intraokulare Fremdkörperdiagnostik in der Multidetektor-CT: Auswirkung der Akquisitionsparameter auf Strahlendosis und Erkennbarkeit. ROFO-FORTSCHR RONTG 2006; 178:90-5. [PMID: 16392062 DOI: 10.1055/s-2005-858763] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE Determination of the influence of acquisition and reconstruction parameters on radiation dose and detectability of intraocular foreign bodies using multidetector CT (MDCT). MATERIALS AND METHODS Porcine eyes with intraocular foreign bodies of a 0.3-mm quartz fiber and a 0.1-mm steel wire as well as 0.5 ml of blood in the vitreous were investigated using MDCT. The tube current was 500, 250, 100, and 50 mAs; the collimation was 16 x 0.75 mm and 16 x 1.5 mm; and the pitch was 0.5 and 0.75. Image reconstruction was performed using a soft tissue (H30), a bone algorithm (H60 s), and thin (0.7 and 2 mm, respectively) and thick (2 and 4 mm, respectively) reconstruction increments. The resulting data sets were then used to determine the signal difference to noise ratio (SDNR) between the foreign body and adjacent vitreous. RESULTS Changes in tube current resulted in a proportional change in the radiation dose but only in the SDNR within a range of 1:2. Reducing the collimation from 1.5 mm to 0.75 mm resulted in a doubling of the SDNR at an approximately identical radiation dose. The series with a lower pitch at the same dose per volume showed a slightly higher SDNR. Reconstruction using a bone algorithm and thin increments resulted in an increase in the mean SDNR by a factor of 1.8 to 2.3. CONCLUSION When diagnosing small intraocular foreign bodies using MDCT, the following parameters can yield an adequate SDNR while minimizing radiation exposure: tube current 50 mAs, pitch 0.5, collimation 16 x 0.75, bone algorithm, and reconstruction increment 0.7 mm.
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16
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Lackner B, Schmidinger G, Pieh S, Skorpik C. Hornhautdickenmessung mittels neuem rotierenden Scheimpflug-Systems (Pentacam). Klin Monbl Augenheilkd 2005. [DOI: 10.1055/s-2005-863928] [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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17
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Schmidinger G, Simader C, Lackner B, Paikl D, Skorpik C, Pieh S. Visusänderung nach Implantation phaker Linsen. Klin Monbl Augenheilkd 2005. [DOI: 10.1055/s-2005-863946] [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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18
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Lackner B, Pieh S, Simader C, Schmidinger G, Franz C, Dejaco-Ruhswurm I, Skorpik C. Inzidenz von Linsentrübungen nach ICL Implantation der neuesten Generation. Klin Monbl Augenheilkd 2004. [DOI: 10.1055/s-2004-820101] [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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19
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Simader C, Schmidinger G, Lackner B, Franz C, Skorpik C, Pieh S. Einfluss des kornealen Astigmatismus auf die unkorrigierte postoperative Sehschärfe nach Implantation unterschiedlich gewichteter Bifokallinsen. Klin Monbl Augenheilkd 2004. [DOI: 10.1055/s-2004-820130] [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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20
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Abstract
In recipients of rotary blood pumps for cardiac assist, the pulsatility of arterial flow is considerably diminished. This influences the shear stress patterns and streamlines in the arterial bed, with potential influence on washout and subsequent plaque growth. To study these effects, a three-dimensional computer simulation of the carotid bifurcation at various levels of flow pulsatility was performed. The results showed that as expected pulsatile shear stress varied considerably, whereas local mean shear stress levels were nearly identical for all degrees of pulsatility. Particle residence time in the carotid bulb did only increase for less than 15%, with secondary washout patterns contributing to good washout also in nonpulsatile conditions. It is concluded that also under continuous pump support the local flow patterns in the carotids provide sufficient washout and fluid exchange to prevent excessive plaque growth.
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Affiliation(s)
- H Schima
- Department for Cardio-Thoracic Surgery, University of Vienna, Vienna, Austria.
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21
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Funovics MA, Philipp MO, Lackner B, Fuchsjaeger M, Funovics PT, Metz V. Galactography: method of choice in pathologic nipple discharge? Eur Radiol 2003; 13:94-9. [PMID: 12541115 DOI: 10.1007/s00330-002-1401-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2001] [Revised: 01/17/2002] [Accepted: 02/04/2002] [Indexed: 10/25/2022]
Abstract
Our objective was to assess the role of galactography in the diagnostic work-up of patients with pathological nipple discharge together with exfoliative cytology, and investigation of secretion colour. All galactographies performed in this center between 1993 and 1998 were evaluated retrospectively. In 134 cases, outcomes, defined as either a postoperative histology or a negative follow-up over 2 years after galactography, were available. In 96 of these cases, exfoliative cytology was performed, and in 65 cases the colour of the secretion was determined. Galactograms, cytological findings and colour of the secretions were compared with the outcomes. At galactography, the radiographic findings had the following individual sensitivities/specificities in detecting carcinomas: filling defect 55.6%/62.1%; ductectasia 22.2%/94%; and filling stop 5.6%/77.6%. Normal galactograms (n=33, 25%) had a sensitivity of 78% and a specificity of 93% in predicting absence of disease. Technically inadequate investigations occurred in 16 (12%) cases. Cytology showed 69.2%/66.8% for papillomatous borderline or malignant cells; 53.8%/75.3% for borderline or malignant cells; and 7.7%/100% for one case of malignant cells. For the assessment of pathological secretions, galactography is a sensitive but unspecific method for the detection of papillomas or carcinomas. Filling defects, ductectasia and ductal distortion carry the highest levels of suspicion for carcinoma. A normal galactogram is a specific yet moderately sensitive indicator of absence of localized disease. Exfoliative cytology shows low sensitivity but better specificity for carcinomas when borderline or malignant cells are found. In the present series, the colour of the secretions does not add significant information about underlying pathology.
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Affiliation(s)
- M A Funovics
- Department of Radiology, University of Vienna Medical School, Vienna General Hospital, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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22
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Funovics MA, Lackner B, Cejna M, Peloschek P, Sailer J, Philipp MO, Maca T, Ahmadi A, Minar E, Lammer J. Predictors of long-term results after treatment of iliac artery obliteration by transluminal angioplasty and stent deployment. Cardiovasc Intervent Radiol 2002; 25:397-402. [PMID: 12447561 DOI: 10.1007/s00270-002-1877-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate initial and long-term success rate after percutaneous treatment of iliac artery occlusion with angioplasty and stent deployment. To investigate the influence of vascular comorbidity, lesion length, stent placement and lesion coverage as possible predictors of outcome. METHODS Between January 1994 and December 1999, 80 iliac recanalizations were performed on 78 patients, median age 61.1 +/- 11.5 (SD) years. All patients were followed up by clinical examinations, duplex ultrasound and intravenous digital subtraction angiography. Mean follow-up time was 2.0 +/- 1.53 (SD) years. Multivariate Cox regression analysis was used to determine the influence of cofactors on patency. RESULTS One, 2 and 4 years after recanalization, primary patency was 78.1%, 74.5% and 64.0%; secondary patency was 88.8%, 88.8% and 77.9%, respectively. Patients with shorter occlusions, complete lesion coverage and patent ipsilateral femoral arteries had significantly longer patency rates. Complications included inguinal hematoma (n=1), technical failure (n=3) aortic dissection (n=1), embolic occlusions (n=7), gluteal claudication (n=1) and genital necrosis after subsequent urethral surgery in one patient with contralateral occlusion and ipsilateral overstenting of the internal iliac artery with subsequent stenosis. Complications were of permanent clinical significance in seven of 78 (9%) of the patients. In 17 (22%) cases, percutaneous reintervention was performed with angioplasty in the stent (n=16) or deployment of a new stent (n=1). CONCLUSION Endoluminal stent placement has its place in an interdisciplinary therapeutic approach as a viable therapeutic alternative to major transabdominal bypass surgery and can be performed with comparable complication rates. Patients with short occlusions, patent femoral arteries, and stents covering the entire occlusion have significant longer patency.
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Affiliation(s)
- M A Funovics
- Department of Angiography and Interventional Radiology, University of Vienna Medical School, Vienna General Hospital, A-1090 Vienna, Austria.
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Pieh S, Lackner B, Hanselmayer G, Zöhrer R, Sticker M, Weghaupt H, Fercher A, Skorpik C. Halo size under distance and near conditions in refractive multifocal intraocular lenses. Br J Ophthalmol 2001; 85:816-21. [PMID: 11423456 PMCID: PMC1724058 DOI: 10.1136/bjo.85.7.816] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [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: 11/03/2022]
Abstract
AIMS To calculate the diameter of halos perceived by patients with multifocal intraocular lenses (IOLs) and to stimulate halos in patients with refractive multifocal IOLs in a clinical experiment. METHODS Calculations were done to show the diameter of halos in the case of the bifocal intraocular lens. 24 patients with a refractive multifocal IOLs and five patients with a monofocal IOL were asked about their subjective observation of halos and were included in a clinical experiment using a computer program (Glare & Halo, FW Fitzke and C Lohmann, Tomey AG) which simulates a light source of 0.15 square degrees (sq deg) in order to stimulate and measure halos. Halo testing took place monoculary, under mesopic conditions through the distance and the near focus of the multifocal lens and through the focus of the monofocal lens. RESULTS The halo diameter depends on the pupil diameter, the refractive power of the cornea, and distance focus of the multifocal IOL as well as the additional lens power for the near focus. 23 out of 24 patients with a refractive multifocal IOL described halos at night when looking at a bright light source. Only one patient was disturbed by the appearance of halos. Under test conditions, halos were detected in all patients with a refractive multifocal IOL. The halo area testing through the distance focus was 1.05 sq deg +/- 0.41, through the near focus 1.07 sq deg +/- 0.49 and in the monofocal lens 0.26 sq deg +/- 0.13. CONCLUSIONS Under high contrast conditions halos can be stimulated in all patients with multifocal intraocular lenses. The halo size using the distance or the near focus is identical.
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Affiliation(s)
- S Pieh
- Department of Ophthalmology, University of Vienna, Medical School, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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24
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Pieh S, Hanselmayer G, Lackner B, Marvan P, Grechenig A, Weghaupt H, Vass C, Skorpik C. Tritan colour contrast sensitivity function in refractive multifocal intraocular lenses. Br J Ophthalmol 2001; 85:811-5. [PMID: 11423455 PMCID: PMC1724048 DOI: 10.1136/bjo.85.7.811] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [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: 11/03/2022]
Abstract
AIMS To compare tritan colour contrast sensitivity (CCS), without and with glare, in patients with refractive multifocal intraocular lenses (IOLs) and with monofocal intraocular lenses. METHODS Tritan CCS was determined (Moorfields Vision System, CH Electronics) in 15 eyes (14 patients, 75.7 (+/-6.6) years) with a refractive multifocal IOL (Allergan SA 40N) and in 11 eyes (10 patients, 73.7 (+/-6.4) years) with a monofocal IOL (Allergan SI 40 NB). Measurements were made monocularly under mesopic conditions at a distance of 2 metres from the monitor with best distance refraction plus 0.5 D at 0.5, 1, 3, 6, 11.4, and 22.8 cycles per degree (cpd). The test was then repeated for the multifocal IOLs, adding minus 2.5 D to the best distance refraction to force the patient to use the near focus. Both lenses were also investigated under glare conditions with the same set-up and using the brightness acuity tester (BAT). RESULTS The tritan CCS function without glare in multifocal lenses through the distance focus was nearly identical to that through the near focus. The following statistically significant differences were measured: the CCS function without glare for the multifocal lens was worse at 0.5 cpd and 1.0 cpd than that of the monofocal lens. In CCS testing of the multifocal group with glare at 6 cpd, the results through the distance focus were better than the results through the near focus. For the CCS function with glare, the values for the distance focus in the multifocal lens were worse than the values for the monofocal lens at 0.5 cpd and 1 cpd. In CCS testing with glare through the near focus and CCS testing through the monofocal lens, the monofocal lens performed better at 0.5 cpd, 1 cpd, 3 cpd, and 6 cpd. CONCLUSION Refractive multifocal intraocular lenses influence tritan CCS function compared to monofocal lenses.
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Affiliation(s)
- S Pieh
- Department of Ophthalmology, University of Vienna, Medical School, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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25
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Funovics M, Schamp S, Helbich TH, Lackner B, Wunderbaldinger P, Fuchsjäger M, Lechner G, Wolf G. [Evaluation of a computer-assisted diagnosis system in breast carcinoma]. ROFO-FORTSCHR RONTG 2001; 173:218-23. [PMID: 11293863 DOI: 10.1055/s-2001-11608] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [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: 10/16/2022]
Abstract
PURPOSE Evaluation of a computerassisted diagnosis (CAD) system (R2 linage Checker 1.2). Comparison of the results of three readers with and without knowledge of the computer results. MATERIALS AND METHODS The mammograms of 52 patients, bilaterally in two planes each, with histologically proven carcinoma of the breast were included in the study. They were first scanned by the CAD machine and subsequently read by three readers with different degrees of experience in two sessions with and without knowledge of the computer results. RESULTS Of the 91 views of carcinomas, the readers detected 96%, 89%, and 85%, respectively. With CAD, the values rose to 97%, 93%, and 96%. The increase of the first observer was not significant. As for the 49 areas of malignant microcalcifications, the first reader showed a significant decrease of sensitivity, the other two readers showed no significant change. The sensitivity of CAD was 74% for masses and 86% for microcalcifications at a rate of 1.8 false positive markers per image. All but two tumors were correctly marked in at least one plane. CONCLUSIONS Use of the CAD machine led to a significant increase of sensitivity in the detection of malignant masses by two of three observers. In the case of malignant microcalcifications, and for the most experienced observer, CAD did not improve the results. The most important problem is the high rate of false positive markers.
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Affiliation(s)
- M Funovics
- Universitätsklinik für Radiodiagnostik, AKH Wien.
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26
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Abstract
The case of a 30 year old man with acatalasemia is presented. The congenital disorder is charaterized by a lack or major reduction of catalase, an enzyme that catalyzes the decomposition of hydrogen peroxide to oxygen and water. The defect is inherited in an autosomal recessive fashion. Occasionally the defect manifests as progressive oral gangrene or Takahara's, disease.
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Affiliation(s)
- H Perner
- Dermatologische Abteilung der Landeskrankenanstallen Saltzburg
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27
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Funovics M, Herneth A, Lackner B, Imhof H. Quiz case 10. Metastasising retroduodenal gastrinoma. Eur J Radiol 1999; 31:152-5. [PMID: 10565514 DOI: 10.1016/s0720-048x(99)00092-3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A 37-year-old male patient with no significant past medical history presented with a 6-month history of intermittent epigastric pain which was partially relieved by antacid medication. Gastroscopy showed a peptic ulcer and the biopsies that were taken did not show signs of malignancy. Conservative treatment was initiated, but healing was prolonged, and the epigastric pain persisted. The patient was referred to our department for further diagnosis.
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Affiliation(s)
- M Funovics
- Department of Radiology, Vienna General Hospital, University of Vienna, Austria
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28
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Funovics M, Schamp S, Lackner B, Wunderbaldinger P, Lechner G, Wolf G. [Computer-assisted diagnosis in mammography: the R2 ImageChecker System in detection of spiculated lesions]. Wien Med Wochenschr 1998; 148:321-4. [PMID: 9816642] [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: 02/09/2023]
Abstract
Because of the rapid development of computer systems for digitalization and image analysis, they play an increasing important role in computer-assisted diagnosis (CAD). Especially in the field of mammography, the early signs of malignancy are relatively uniform and therefore more easily detected by a computer algorithm. In this study, we tested one of the few commercially available systems for the detection of both microcalcifications and suspicious, spiculated solid lesions on 40 cases of proven breast carcinomas. These mammograms were analyzed by three independent observers with and without knowledge of the computer results, respectively. Depending on the time of their radiologic experience, the sensitivity of the observers alone was 92.4%, 86.1% and 82%. With knowledge of the computer interpretation, sensitivity of all three observers rose significantly to 100%, 92.7%, and 95%, respectively. However, due to a high number of false positive results of the computer algorithm (0.4 markers per image), the positive predictive value of the interpretations worsened from 100%, 92.7%, and 95.5% to 86.4%, 97.3%, and 91.1%, respectively. It can be expected that future developments will soon overcome this problem and CAD will become an effective tool in screening mammography.
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Affiliation(s)
- M Funovics
- Universitätsklinik für Radiodiagnostik, Wien.
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Widhalm K, Lackner B, Bauernfried M. Medical education in nutrition in Europe. Workshop. Ann Nutr Metab 1997; 41:66-8. [PMID: 9195003 DOI: 10.1159/000177980] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- K Widhalm
- Department of Pediatrics, University of Vienna, Austria
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30
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Dohrmann U, Fisher PR, Broderlein M, Lackner B, Williams KL. Arachidonic Acid and Related Molecules Affect the Behaviour of Dictyostelium discoideum Slugs. Microbiology (Reading) 1984. [DOI: 10.1099/00221287-130-10-2685] [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: 11/18/2022] Open
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