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Nguyen D, Prieto C, Liu Z, Wheat J, Perez A, Gourkanti S, Chou T, Barin E, Velleca A, Rohwetter T, Chow A, Taggart J, Savino A, Hoskova K, Dhodapkar M, Schurer A, Barlowe T, Leslie C, Vu L, Steidl U, Rabandan R, Kharas M. 2007 – TRANSCRIPTIONAL CONTROL OF CBX5 BY THE RNA BINDING PROTEINS RBMX AND RBMXL1 MAINTAINS CHROMATIN STATE IN MYELOID LEUKEMIA. Exp Hematol 2021. [DOI: 10.1016/j.exphem.2021.12.372] [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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2
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Prieto C, Nguyen DTT, Liu Z, Wheat J, Perez A, Gourkanti S, Chou T, Barin E, Velleca A, Rohwetter T, Chow A, Taggart J, Savino AM, Hoskova K, Dhodapkar M, Schurer A, Barlowe TS, Vu LP, Leslie C, Steidl U, Rabadan R, Kharas MG. Transcriptional control of CBX5 by the RNA binding proteins RBMX and RBMXL1 maintains chromatin state in myeloid leukemia. Nat Cancer 2021; 2:741-757. [PMID: 34458856 PMCID: PMC8388313 DOI: 10.1038/s43018-021-00220-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 05/11/2021] [Indexed: 01/08/2023]
Abstract
RNA binding proteins (RBPs) are key arbiters of post-transcriptional regulation and are found to be found dysregulated in hematological malignancies. Here, we identify the RBP RBMX and its retrogene RBMXL1 to be required for murine and human myeloid leukemogenesis. RBMX/L1 are overexpressed in acute myeloid leukemia (AML) primary patients compared to healthy individuals, and RBMX/L1 loss delayed leukemia development. RBMX/L1 loss lead to significant changes in chromatin accessibility, as well as chromosomal breaks and gaps. We found that RBMX/L1 directly bind to mRNAs, affect transcription of multiple loci, including CBX5 (HP1α), and control the nascent transcription of the CBX5 locus. Forced CBX5 expression rescued the RBMX/L1 depletion effects on cell growth and apoptosis. Overall, we determine that RBMX/L1 control leukemia cell survival by regulating chromatin state through their downstream target CBX5. These findings identify a mechanism for RBPs directly promoting transcription and suggest RBMX/L1, as well as CBX5, as potential therapeutic targets in myeloid malignancies.
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Affiliation(s)
- Camila Prieto
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Diu T T Nguyen
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Zhaoqi Liu
- Program for Mathematical Genomics, Department of Systems Biology, Department of Biomedical Informatics, Columbia University Medical Center, New York, NY, USA
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing 100101, China
| | - Justin Wheat
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY USA
| | - Alexendar Perez
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Saroj Gourkanti
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Timothy Chou
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ersilia Barin
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Anthony Velleca
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Thomas Rohwetter
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Arthur Chow
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - James Taggart
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Angela M Savino
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Katerina Hoskova
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Meera Dhodapkar
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Alexandra Schurer
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Trevor S Barlowe
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ly P Vu
- Terry Fox Laboratory, British Columbia Cancer Research Centre, Vancouver, BC, Canada; Molecular Biology and Biochemistry, Simon Fraser University, Vancouver, BC, Canada
| | - Christina Leslie
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ulrich Steidl
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY USA
| | - Raul Rabadan
- Program for Mathematical Genomics, Department of Systems Biology, Department of Biomedical Informatics, Columbia University Medical Center, New York, NY, USA
| | - Michael G Kharas
- Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Center for Hematologic Malignancies, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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3
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Leyva-Díaz JC, Phonbun RA, Taggart J, Díaz E, Ordóñez S. Influence of nalidixic acid on tandem heterotrophic-autotrophic kinetics in a "NIPHO" activated sludge reactor. Chemosphere 2019; 218:128-137. [PMID: 30471493 DOI: 10.1016/j.chemosphere.2018.11.107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 10/22/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
This work analyzes the effect of nalidixic acid (NAL) on the kinetics of the heterotrophic and autotrophic biomass growth within a "NIPHO" activated sludge reactor treating municipal wastewater. Thus, the effect of this chemical in the degradation rates of carbon and nitrogen sources and net biomass growth rate is evaluated. Activated sludge samples were taken at three different operation conditions, changing the values of hydraulic retention time (2.8-3.8 h), biomass concentration (1400-1700 mgVSS L-1), temperature (12.6-14.8 °C), and sludge retention time (11.0-12.6 day). A respirometric method was applied to model the kinetic performance of heterotrophic and autotrophic biomass in absence and presence of NAL, and a multivariable statistical analysis was carried out to characterize the influence of the operation variables on the kinetic response of the system, which was finally optimized. The results showed that there was no inhibitory effect of NAL on heterotrophic biomass, with an increase of net heterotrophic biomass growth rate from 1.70 to 6.73 mgVSS L-1 h-1 at the most favorable period. By contrast, the autotrophic biomass was negatively affected by NAL, reducing the value of net autotrophic biomass growth rate from 25.37 to 10.29 mgVSS L-1 h-1 at the best operation conditions. In general, biomass concentration and temperature had the highest influence on the degradation rate of carbon and nitrogen sources, whereas hydraulic retention time and sludge retention time were the most influential on net heterotrophic and autotrophic biomass growth rates.
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Affiliation(s)
- J C Leyva-Díaz
- Department of Chemical and Environmental Engineering, University of Oviedo, 33006, Oviedo, Spain.
| | - R A Phonbun
- Department of Chemical and Process Engineering, University of Strathclyde, G11XJ, Glasgow, United Kingdom
| | - J Taggart
- Department of Chemical and Process Engineering, University of Strathclyde, G11XJ, Glasgow, United Kingdom
| | - E Díaz
- Department of Chemical and Environmental Engineering, University of Oviedo, 33006, Oviedo, Spain
| | - S Ordóñez
- Department of Chemical and Environmental Engineering, University of Oviedo, 33006, Oviedo, Spain.
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4
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Park SM, Cho H, Thornton AM, Barlowe TS, Chou T, Chhangawala S, Fairchild L, Taggart J, Chow A, Schurer A, Gruet A, Witkin MD, Kim JH, Shevach EM, Krivtsov A, Armstrong SA, Leslie C, Kharas MG. IKZF2 Drives Leukemia Stem Cell Self-Renewal and Inhibits Myeloid Differentiation. Cell Stem Cell 2019; 24:153-165.e7. [PMID: 30472158 PMCID: PMC6602096 DOI: 10.1016/j.stem.2018.10.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 08/06/2018] [Accepted: 10/10/2018] [Indexed: 01/08/2023]
Abstract
Leukemias exhibit a dysregulated developmental program mediated through both genetic and epigenetic mechanisms. Although IKZF2 is expressed in hematopoietic stem cells (HSCs), we found that it is dispensable for mouse and human HSC function. In contrast to its role as a tumor suppressor in hypodiploid B-acute lymphoblastic leukemia, we found that IKZF2 is required for myeloid leukemia. IKZF2 is highly expressed in leukemic stem cells (LSCs), and its deficiency results in defective LSC function. IKZF2 depletion in acute myeloid leukemia (AML) cells reduced colony formation, increased differentiation and apoptosis, and delayed leukemogenesis. Gene expression, chromatin accessibility, and direct IKZF2 binding in MLL-AF9 LSCs demonstrate that IKZF2 regulates a HOXA9 self-renewal gene expression program and inhibits a C/EBP-driven differentiation program. Ectopic HOXA9 expression and CEBPE depletion rescued the effects of IKZF2 depletion. Thus, our study shows that IKZF2 regulates the AML LSC program and provides a rationale to therapeutically target IKZF2 in myeloid leukemia.
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MESH Headings
- Animals
- Cell Differentiation
- Cell Self Renewal
- Chromatin/genetics
- Chromatin/metabolism
- DNA-Binding Proteins/physiology
- Female
- Gene Expression Regulation, Leukemic
- Hematopoiesis
- Leukemia, Experimental/genetics
- Leukemia, Experimental/metabolism
- Leukemia, Experimental/pathology
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neoplastic Stem Cells/metabolism
- Neoplastic Stem Cells/pathology
- Transcription Factors/physiology
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Affiliation(s)
- Sun-Mi Park
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Hyunwoo Cho
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Angela M Thornton
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA
| | - Trevor S Barlowe
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Timothy Chou
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Sagar Chhangawala
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Lauren Fairchild
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - James Taggart
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Arthur Chow
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Alexandria Schurer
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Antoine Gruet
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew D Witkin
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jun Hyun Kim
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ethan M Shevach
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, USA
| | - Andrei Krivtsov
- Department of Pediatric Oncology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Scott A Armstrong
- Department of Pediatric Oncology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Christina Leslie
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Michael G Kharas
- Molecular Pharmacology Program and Center for Cell Engineering, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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5
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Vu LP, Prieto C, Amin EM, Chhangawala S, Krivtsov A, Calvo-Vidal MN, Chou T, Chow A, Minuesa G, Park SM, Barlowe TS, Taggart J, Tivnan P, Deering RP, Chu LP, Kwon JA, Meydan C, Perales-Paton J, Arshi A, Gönen M, Famulare C, Patel M, Paietta E, Tallman MS, Lu Y, Glass J, Garret-Bakelman FE, Melnick A, Levine R, Al-Shahrour F, Järås M, Hacohen N, Hwang A, Garippa R, Lengner CJ, Armstrong SA, Cerchietti L, Cowley GS, Root D, Doench J, Leslie C, Ebert BL, Kharas MG. Functional screen of MSI2 interactors identifies an essential role for SYNCRIP in myeloid leukemia stem cells. Nat Genet 2017; 49:866-875. [PMID: 28436985 PMCID: PMC5508533 DOI: 10.1038/ng.3854] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [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: 10/30/2016] [Accepted: 03/31/2017] [Indexed: 12/15/2022]
Abstract
The identity of the RNA-binding proteins (RBPs) that govern cancer stem cells remains poorly characterized. The MSI2 RBP is a central regulator of translation of cancer stem cell programs. Through proteomic analysis of the MSI2-interacting RBP network and functional shRNA screening, we identified 24 genes required for in vivo leukemia. Syncrip was the most differentially required gene between normal and myeloid leukemia cells. SYNCRIP depletion increased apoptosis and differentiation while delaying leukemogenesis. Gene expression profiling of SYNCRIP-depleted cells demonstrated a loss of the MLL and HOXA9 leukemia stem cell program. SYNCRIP and MSI2 interact indirectly though shared mRNA targets. SYNCRIP maintains HOXA9 translation, and MSI2 or HOXA9 overexpression rescued the effects of SYNCRIP depletion. Altogether, our data identify SYNCRIP as a new RBP that controls the myeloid leukemia stem cell program. We propose that targeting these RBP complexes might provide a novel therapeutic strategy in leukemia.
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Affiliation(s)
- Ly P Vu
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Camila Prieto
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA
| | - Elianna M Amin
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Sagar Chhangawala
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York, USA.,Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Andrei Krivtsov
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - M Nieves Calvo-Vidal
- Department of Medicine, Division of Hematology/Oncology, Weill Cornell Medical College, New York, New York, USA
| | - Timothy Chou
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Arthur Chow
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Gerard Minuesa
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Sun Mi Park
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Trevor S Barlowe
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - James Taggart
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Patrick Tivnan
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | | | - Lisa P Chu
- Division of Hematology, Brigham and Woman's Hospital, Boston, Massachusetts, USA
| | | | - Cem Meydan
- Institute for Computational Biomedicine, Department of Physiology and Biophysics, Weill Cornell Medical College, New York, New York, USA
| | - Javier Perales-Paton
- Translational Bioinformatics Unit, Clinical Research Programme, Spanish National Cancer Research Centre, Madrid, Spain
| | - Arora Arshi
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Mithat Gönen
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Christopher Famulare
- Human Oncology and Pathogenesis Program, Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Minal Patel
- Human Oncology and Pathogenesis Program, Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Elisabeth Paietta
- Department of Medicine, Montefiore Medical Center, Bronx, New York, USA
| | - Martin S Tallman
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Hospital, New York, New York, USA
| | - Yuheng Lu
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Jacob Glass
- Leukemia Service, Department of Medicine, Memorial Sloan Kettering Hospital, New York, New York, USA
| | - Francine E Garret-Bakelman
- Department of Medicine and Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, Virginia, USA.,Division of Hematology and Medical Oncology, Departments of Medicine and Pharmacology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ari Melnick
- Division of Hematology and Medical Oncology, Departments of Medicine and Pharmacology, Weill Cornell Medical College, Cornell University, New York, New York, USA
| | - Ross Levine
- Human Oncology and Pathogenesis Program, Leukemia Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Fatima Al-Shahrour
- Translational Bioinformatics Unit, Clinical Research Programme, Spanish National Cancer Research Centre, Madrid, Spain
| | - Marcus Järås
- Department of Clinical Genetics, Lund University, Lund, Sweden
| | - Nir Hacohen
- Harvard Medical School, Boston, Massachusetts, USA
| | - Alexia Hwang
- RNAi Core, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Ralph Garippa
- RNAi Core, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Christopher J Lengner
- Department of Animal Biology, Department of Cell and Developmental Biology, and Institute for Regenerative Medicine, Schools of Veterinary Medicine and Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Scott A Armstrong
- Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Leandro Cerchietti
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Glenn S Cowley
- Discovery Sciences, Janssen Research and Development, Spring House, Pennsylvania, USA
| | - David Root
- Broad Institute, Boston, Massachusetts, USA
| | | | - Christina Leslie
- Computational Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Benjamin L Ebert
- Division of Hematology, Brigham and Woman's Hospital, Boston, Massachusetts, USA
| | - Michael G Kharas
- Molecular Pharmacology Program, Center for Cell Engineering, Center for Stem Cell Biology, and Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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6
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Affiliation(s)
- Tzu-Chieh Ho
- a Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center , New York , NY , USA
| | - James Taggart
- a Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center , New York , NY , USA
| | - Michael G Kharas
- a Molecular Pharmacology Program and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center , New York , NY , USA
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7
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Taggart J, Ho TC, Amin E, Xu H, Barlowe TS, Perez AR, Durham BH, Tivnan P, Okabe R, Chow A, Vu L, Park SM, Prieto C, Famulare C, Patel M, Lengner CJ, Verma A, Roboz G, Guzman M, Klimek VM, Abdel-Wahab O, Leslie C, Nimer SD, Kharas MG. MSI2 is required for maintaining activated myelodysplastic syndrome stem cells. Nat Commun 2016; 7:10739. [PMID: 26898884 PMCID: PMC4764878 DOI: 10.1038/ncomms10739] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 07/29/2015] [Accepted: 01/14/2016] [Indexed: 12/22/2022] Open
Abstract
Myelodysplastic syndromes (MDS) are driven by complex genetic and epigenetic alterations. The MSI2 RNA-binding protein has been demonstrated to have a role in acute myeloid leukaemia and stem cell function, but its role in MDS is unknown. Here, we demonstrate that elevated MSI2 expression correlates with poor survival in MDS. Conditional deletion of Msi2 in a mouse model of MDS results in a rapid loss of MDS haematopoietic stem and progenitor cells (HSPCs) and reverses the clinical features of MDS. Inversely, inducible overexpression of MSI2 drives myeloid disease progression. The MDS HSPCs remain dependent on MSI2 expression after disease initiation. Furthermore, MSI2 expression expands and maintains a more activated (G1) MDS HSPC. Gene expression profiling of HSPCs from the MSI2 MDS mice identifies a signature that correlates with poor survival in MDS patients. Overall, we identify a role for MSI2 in MDS representing a therapeutic target in this disease. Several studies have recently demonstrated the role of the MSI2 RNA binding protein in normal and malignant haematopoietc stem cells. In this study, the authors show that MSI2 is required for maintaining myelodysplastic syndrome stem cells in mice and that MSI2 expression predicts poor prognosis in patients affected by this disease.
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Affiliation(s)
- James Taggart
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Tzu-Chieh Ho
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Elianna Amin
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Haiming Xu
- Memorial Sloan Kettering Cancer Center, Cancer Biology Program, New York, New York 10065, USA
| | - Trevor S Barlowe
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Alexendar R Perez
- Computational Biology Program Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Institute, New York, New York 10065, USA
| | - Benjamin H Durham
- Memorial Sloan Kettering Cancer Center, Human Oncology and Pathogenesis Program, New York, New York 10065, USA
| | - Patrick Tivnan
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Rachel Okabe
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Arthur Chow
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Ly Vu
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Sun Mi Park
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Camila Prieto
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Christopher Famulare
- Memorial Sloan Kettering Cancer Center, Department of Medicine, Leukemia Service, New York, New York 10065, USA
| | - Minal Patel
- Memorial Sloan Kettering Cancer Center, Department of Medicine, Leukemia Service, New York, New York 10065, USA
| | - Christopher J Lengner
- Department of Animal Biology, Department of Cell and Developmental Biology and Institute for Regenerative Medicine, Schools of Veterinary Medicine and Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Amit Verma
- Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Gail Roboz
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York 10065, USA
| | - Monica Guzman
- Division of Hematology and Medical Oncology, Department of Medicine and Pharmacology, Weill Cornell Medical College, Cornell University, New York, New York 10065, USA
| | - Virginia M Klimek
- Memorial Sloan Kettering Cancer Center, Department of Medicine, Leukemia Service, New York, New York 10065, USA
| | - Omar Abdel-Wahab
- Memorial Sloan Kettering Cancer Center, Human Oncology and Pathogenesis Program, New York, New York 10065, USA
| | - Christina Leslie
- Computational Biology Program Memorial Sloan Kettering Cancer Center, Memorial Sloan Kettering Institute, New York, New York 10065, USA
| | - Stephen D Nimer
- Sylvester Comprehensive Cancer Center, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA
| | - Michael G Kharas
- Molecular Pharmacology and Center for Cell Engineering, Center for Stem Cell Biology, Center for Experimental Therapeutics, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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Park SM, Gönen M, Vu L, Minuesa G, Tivnan P, Barlowe TS, Taggart J, Lu Y, Deering RP, Hacohen N, Figueroa ME, Paietta E, Fernandez HF, Tallman MS, Melnick A, Levine R, Leslie C, Lengner CJ, Kharas MG. Musashi2 sustains the mixed-lineage leukemia-driven stem cell regulatory program. J Clin Invest 2015; 125:1286-98. [PMID: 25664853 DOI: 10.1172/jci78440] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 01/05/2015] [Indexed: 01/15/2023] Open
Abstract
Leukemia stem cells (LSCs) are found in most aggressive myeloid diseases and contribute to therapeutic resistance. Leukemia cells exhibit a dysregulated developmental program as the result of genetic and epigenetic alterations. Overexpression of the RNA-binding protein Musashi2 (MSI2) has been previously shown to predict poor survival in leukemia. Here, we demonstrated that conditional deletion of Msi2 in the hematopoietic compartment results in delayed leukemogenesis, reduced disease burden, and a loss of LSC function in a murine leukemia model. Gene expression profiling of these Msi2-deficient animals revealed a loss of the hematopoietic/leukemic stem cell self-renewal program and an increase in the differentiation program. In acute myeloid leukemia patients, the presence of a gene signature that was similar to that observed in Msi2-deficent murine LSCs correlated with improved survival. We determined that MSI2 directly maintains the mixed-lineage leukemia (MLL) self-renewal program by interacting with and retaining efficient translation of Hoxa9, Myc, and Ikzf2 mRNAs. Moreover, depletion of MLL target Ikzf2 in LSCs reduced colony formation, decreased proliferation, and increased apoptosis. Our data provide evidence that MSI2 controls efficient translation of the oncogenic LSC self-renewal program and suggest MSI2 as a potential therapeutic target for myeloid leukemia.
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9
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Power J, Taggart J, Parker M, Berry JL, Reeve J. Bone marrow levels of 25 hydroxy vitamin D are not depressed in cases of hip fracture compared with controls. Cell Biochem Funct 2014; 32:341-3. [PMID: 24375617 DOI: 10.1002/cbf.3021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 11/11/2013] [Accepted: 11/22/2013] [Indexed: 11/11/2022]
Abstract
There is little information on tissue as distinct from plasma levels of vitamin D metabolites in cases of hip fracture compared with controls. Femoral neck fractures in the elderly are associated with increased cortical remodelling and endosteal resorption, leading to regional increases in porosity and reduced cortical thickness. Vitamin D metabolites play a central role in the maintenance of normal serum calcium levels and may, through interactions with parathyroid hormone, exert an important influence on bone structure. To investigate whether hip fracture might be associated with tissue vitamin D deficiency, we have measured by radioimmunoassay the levels of 25 hydroxy vitamin D (25 (OH)D) in bone marrow samples extracted from the proximal femurs of 16 female subjects who had suffered fracture (mean age = 82.1 years, standard error (se) 1.9) and nine sex matched post mortem controls (mean age = 83.8 years, se 2.5). Twenty five (OH)D concentrations were significantly greater in the fracture cases (median = 3.7, IQR = 2.5-3.9 ng/g) than in the control group (median = 1.5, IQR = 0.9-2.3 ng/g; P = 0.0007, non-parametric Wilcoxon/Kruskal-Wallis test). It was suggested in the 1970s that bone loss and hip fracture risk in the UK were driven by vitamin D deficiency. Our results suggest that the alterations in femoral neck bone microstructure and remodelling in hip fracture cannot be assigned to the single cause of relative deficiency of vitamin D. Vitamin D deficiency or insufficiency may nevertheless increase remodelling and loss of bone tissue and contribute causally to a minority of hip fractures.
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Affiliation(s)
- J Power
- Department of Biological Sciences, University of Chester, Chester, UK
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10
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Jones M, Osawa G, Regal JA, Weinberg DN, Taggart J, Kocak H, Friedman A, Ferguson DO, Keegan CE, Maillard I. Hematopoietic stem cells are acutely sensitive to Acd shelterin gene inactivation. J Clin Invest 2013; 124:353-66. [PMID: 24316971 DOI: 10.1172/jci67871] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/03/2013] [Indexed: 12/26/2022] Open
Abstract
The shelterin complex plays dual functions in telomere homeostasis by recruiting telomerase and preventing the activation of a DNA damage response at telomeric ends. Somatic stem cells require telomerase activity, as evidenced by progressive stem cell loss leading to bone marrow failure in hereditary dyskeratosis congenita. Recent work demonstrates that dyskeratosis congenita can also arise from mutations in specific shelterin genes, although little is known about shelterin functions in somatic stem cells. We found that mouse hematopoietic stem cells (HSCs) are acutely sensitive to inactivation of the shelterin gene Acd, encoding TPP1. Homozygosity for a hypomorphic acd allele preserved the emergence and expansion of fetal HSCs but led to profoundly defective function in transplantation assays. Upon complete Acd inactivation, HSCs expressed p53 target genes, underwent cell cycle arrest, and were severely depleted within days, leading to hematopoietic failure. TPP1 loss induced increased telomeric fusion events in bone marrow progenitors. However, unlike in epidermal stem cells, p53 deficiency did not rescue TPP1-deficient HSCs, indicating that shelterin dysfunction has unique effects in different stem cell populations. Because the consequences of telomere shortening are progressive and unsynchronized, acute loss of shelterin function represents an attractive alternative for studying telomere crisis in hematopoietic progenitors.
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11
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Dordea AC, Sweeney M, Taggart J, Lartey J, Wessel H, Robson SC, Taggart MJ. Differential vasodilation of human placental and myometrial arteries related to myofilament Ca(2+)-desensitization and the expression of Hsp20 but not MYPT1. Mol Hum Reprod 2013; 19:727-36. [PMID: 23775458 DOI: 10.1093/molehr/gat045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Endothelial-dependent regulation of vascular tone occurs in part via protein kinase G1α-mediated changes in smooth muscle myofilament sensitivity to Ca(2+). Tissue-specific differences in PKG-dependent relaxation have been attributed to altered expression of myofilament-associated proteins that are substrates for PKG binding. These include the alternative splicing of the myosin targeting subunit (MYPT1) of myosin light chain phosphatase to yield leucine zipper positive (LZ(+)) and negative (LZ(-)) isovariants, with the former being required for PKG-mediated relaxation, and/or altered expressions of telokin, vasodilator-stimulated phosphoprotein (VASP) or heat shock protein Hsp20. During human pregnancy the uterine and placental circulations remain distinct entities and, as such, their mechanisms of vascular tone regulation may differ. Indeed, the sensitivity of myometrial arteries to endothelial-dependent agonists has been suggested to be greater than that of placental arteries. We tested the hypothesis that this was related to tissue-specific changes in PKG-mediated myofilament Ca(2+)-desensitization and/or the expressions of PKG-interacting myofilament-associated proteins. Permeabilized human placental and myometrial arteries were constricted with maximal activating Ca(2+) (pCa 4.5), or sub-maximal Ca(2+) (pCa 6.7) and the thrombane mimetic U46619, and exposed to 8-Br-cGMP. In each case, relaxation was significantly greater in myometrial arteries (e.g. relaxation in pCa 4.5 to 8-Br-cGMP was 49 ± 9.7%, n = 7) than placental arteries (relaxation of 23 ± 6.6%, n = 6, P < 0.05). MYPT1 protein levels, or MYPT1 LZ(+)/LZ(-) mRNA ratios, were similar for both artery types. Of other proteins examined, only Hsp20 expression was significantly elevated in myometrial arteries than placental arteries. These results demonstrate that the reduced human placental artery relaxation to PKG stimulation lies partly at the level of myofilament (de)activation and may be related to a lower expression of Hsp20 than in myometrial arteries.
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Affiliation(s)
- A C Dordea
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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12
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Liaw S, Rahimi A, Ray P, Taggart J, Dennis S, de Lusignan S, Jalaludin B, Yeo A, Talaei-Khoei A. Corrigendum to “Towards an ontology for data quality in integrated chronic disease management: A realist review of the literature” [Int. J. Med. Inform. 82 (2013) 10–24]. Int J Med Inform 2013. [DOI: 10.1016/j.ijmedinf.2012.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Black DA, Taggart J, Jayasinghe UW, Proudfoot J, Crookes P, Beilby J, Powell-Davis G, Wilson LA, Harris MF, Teamwork Research Team T. The Teamwork Study: enhancing the role of non-GP staff in chronic disease management in general practice. Aust J Prim Health 2013; 19:184-9. [DOI: 10.1071/py11071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Accepted: 05/22/2012] [Indexed: 11/23/2022]
Abstract
There is evidence for a team-based approach in the management of chronic disease in primary health care. However, the standard of care is variable, probably reflecting the limited organisational capacity of health services to provide the necessary structured and organised care for this group of patients. This study aimed to evaluate the impact of a structured intervention involving non-GP staff in GP practices on the quality of care for patients with diabetes or cardiovascular disease. A cluster randomised trial was undertaken across 60 GP practices. The intervention was implemented in 30 practices with staff and patients interviewed at baseline and at 12–15 months follow up. The change in team roles was evaluated using a questionnaire completed by practice staff. The quality of care was evaluated using the Patient Assessment of Chronic Illness Care questionnaire. We found that although the team roles of staff improved in the intervention practices and there were significant differences between practices, there was no significant difference between those in the intervention and control groups in patient-assessed quality of care after adjusting for baseline-level score and covariates at the 12-month follow up. Practice team roles were not significantly associated with change in Patient Assessment of Chronic Illness Care scores. Patients with multiple conditions were more likely to assess their quality of care to be better. Thus, although previous research has shown a cross-sectional association between team work and quality of care, we were unable to replicate these findings in the present study. These results may be indicative of insufficient time for organisational change to result in improved patient-assessed quality of care, or because non-GP staff roles were not sufficiently focussed on the aspects of care assessed. The findings provide important information for researchers when designing similar studies.
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14
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Liaw ST, Rahimi A, Ray P, Taggart J, Dennis S, de Lusignan S, Jalaludin B, Yeo AET, Talaei-Khoei A. Towards an ontology for data quality in integrated chronic disease management: a realist review of the literature. Int J Med Inform 2012; 82:10-24. [PMID: 23122633 DOI: 10.1016/j.ijmedinf.2012.10.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 10/03/2012] [Accepted: 10/05/2012] [Indexed: 11/25/2022]
Abstract
PURPOSE Effective use of routine data to support integrated chronic disease management (CDM) and population health is dependent on underlying data quality (DQ) and, for cross system use of data, semantic interoperability. An ontological approach to DQ is a potential solution but research in this area is limited and fragmented. OBJECTIVE Identify mechanisms, including ontologies, to manage DQ in integrated CDM and whether improved DQ will better measure health outcomes. METHODS A realist review of English language studies (January 2001-March 2011) which addressed data quality, used ontology-based approaches and is relevant to CDM. RESULTS We screened 245 papers, excluded 26 duplicates, 135 on abstract review and 31 on full-text review; leaving 61 papers for critical appraisal. Of the 33 papers that examined ontologies in chronic disease management, 13 defined data quality and 15 used ontologies for DQ. Most saw DQ as a multidimensional construct, the most used dimensions being completeness, accuracy, correctness, consistency and timeliness. The majority of studies reported tool design and development (80%), implementation (23%), and descriptive evaluations (15%). Ontological approaches were used to address semantic interoperability, decision support, flexibility of information management and integration/linkage, and complexity of information models. CONCLUSION DQ lacks a consensus conceptual framework and definition. DQ and ontological research is relatively immature with little rigorous evaluation studies published. Ontology-based applications could support automated processes to address DQ and semantic interoperability in repositories of routinely collected data to deliver integrated CDM. We advocate moving to ontology-based design of information systems to enable more reliable use of routine data to measure health mechanisms and impacts.
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Affiliation(s)
- S T Liaw
- University of NSW School of Public Health & Community Medicine, Sydney, Australia.
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15
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Taggart J, Liaw ST, Dennis S, Yu H, Rahimi A, Jalaludin B, Harris M. The University of NSW electronic practice based research network: disease registers, data quality and utility. Stud Health Technol Inform 2012; 178:219-227. [PMID: 22797045] [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: 06/01/2023]
Abstract
INTRODUCTION Accurate well-maintained registers are a prerequisite to co-ordinated care of patients with chronic diseases. Their effectiveness in enabling improved management is dependent on the quality of the information captured. This paper provides an overview into the methodology and data quality of the electronic Practice Based Research Network. METHODS Clinical records with no identifying information are routinely extracted from four general practices. The data are linked in the data warehouse. Data quality is assessed for completeness, correctness and consistency. Reports on data quality are given back to practices and semi-structured interviews provide information to interpret the results and discuss how data quality could be improved. FINDINGS Data quality is mostly complete for sex and date of birth but indigenous status, smoking and weight were incomplete. There are generally high levels of correctness and internal consistency. Completeness of records in assisting the management of diabetes patients using the annual cycle of care was poor. GPs often use the progress notes to enter information during the consultation and coding diagnoses was considered onerous. DISCUSSION The routine capture of electronic clinical health records from primary health care and health services can be used to monitor performance and improve the quality of clinical records. There is a need for accurate and comprehensive clinical records to ensure the safety and quality of clinical practice. Understanding the true reasons for poor data quality is complex. Having a community-based research network may assist in answering some of these questions. CONCLUSION Electronic health records are increasingly being used for secondary research and evaluation, beyond the primary purpose of supporting clinical care. The data must be of sufficient quality to support these purposes.
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Affiliation(s)
- J Taggart
- University of NSW Centre for Primary Health Care and Equity, Iran
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16
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Taggart J, Summerlin DJ, Moore MG. Parathyroid Carcinosarcoma: A Case Study. Laryngoscope 2011. [DOI: 10.1002/lary.22014] [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: 11/10/2022]
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17
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Abstract
Our results lead us to believe that renin in the form in which it is extracted from the kidney cannot be the agent causing chronic renal hypertension. The reasons against accepting renin as the pressor substance responsible for the hypertension of renal ischemia may be summed up as follows:- 1. The high blood pressure levels of renal ischemia cannot be approximated by any constant injection of renin that will maintain a sustained increase in normal animals. 2. The ratio of size of response to size of dose becomes progressively less as the amount of the dose is increased. If the hypertension of renal ischemia were due to a large elaboration of renin in the body, a small dose injected would be expected to have much less effect than in a normal individual. This is not the case; the response of the hypertensive animal to a given dose of renin is the same. Also animals with increased blood pressure due to a constant infusion of renin respond differently qualitatively and quantitatively to renin than do animals hypertensive from renal ischemia. 3. Since renin exhibits the phenomenon of tachyphylaxis one cannot explain the sustained hypertension of renal ischemia as due to a substance toward which the body becomes refractory as more and more of it is given. If tolerance results from the presence in the renin preparation of an antagonistic contaminant which persists longer in the body than the pressor agent, renal hypertension is definitely not caused by renin. This follows from our observations that rabbits hypertensive from renal ischemia, and in which tolerance is produced, maintain the blood pressure they had before injection of any renin.
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Affiliation(s)
- J Taggart
- Department of Physiology, School of Medicine, University of Southern California, Los Angeles
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18
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Christl B, Harris MF, Jayasinghe UW, Proudfoot J, Taggart J, Tan J. Readiness for organisational change among general practice staff. Qual Saf Health Care 2010; 19:e12. [PMID: 20194220 DOI: 10.1136/qshc.2009.033373] [Citation(s) in RCA: 8] [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] [Indexed: 11/04/2022]
Abstract
BACKGROUND Increasing demands on general practice to manage chronic disease may warrant organisational change at the practice level. Staff's readiness for organisational change can act as a facilitator or barrier to implementing interventions aimed at organisational change. OBJECTIVES To explore general practice staff readiness for organisational change and its association with staff and practices characteristics. METHODS This is a cross-sectional study of practices in three Australian states involved in a randomised control trial on the effectiveness of an intervention to enhance the role of non-general practitioner staff in chronic disease management. Readiness for organisational change, job satisfaction and practice characteristics were assessed using questionnaires. RESULTS 502 staff from 58 practices completed questionnaires. Practice characteristics were not associated with staff readiness for change. A multilevel regression analysis showed statistically significant associations between staff readiness for organisational change (range 1 to 5) and having a non-clinical staff role (vs general practitioner; B=-0.315; 95% CI -0.47 to -0.16; p<0.001), full-time employment (vs part-time; B=0.175, 95% CI 0.06 to 0.29; p<0.01) and lower job satisfaction (B=-0.277, 95% CI -0.40 to -0.15; p<0.001). CONCLUSIONS The results suggest that different approaches are needed to facilitate change which addresses the mix of practice staff. Moderately low job satisfaction may be an opportunity for organisational change.
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Affiliation(s)
- B Christl
- Centre for Primary Health Care and Equity, University of New South Wales, UNSW, Sydney, NSW 2052, Australia
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19
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Taggart J, Schwartz A, Harris MF, Perkins D, Davies GP, Proudfoot J, Fanaian M, Crookes P. Facilitating teamwork in general practice: moving from theory to practice. Aust J Prim Health 2009. [DOI: 10.1071/py08057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aims of this paper are to describe the development of an intervention to improve teamwork and systems in general practice that support the care of patients with diabetes, ischaemic heart disease and hypertension and to identify the challenges to implementing the intervention. Effective teamwork in general practice encompasses general practitioners (GP), clinical and non-clinical staff, each with clearly defined roles and opportunities to provide feedback and input into how the practice is run and chronic disease managed. The intervention implemented in this study provided an opportunity for key members of general practice teams to work with a facilitator on changes to improve teamwork over three practice visits over 6–12 months. Facilitators had experience in practice support and goal setting, an understanding of the Medicare Items and knowledge about teamwork and systems. The visits focussed on the specific needs and capacities of each practice, assisting the team to set manageable goals and building systems that best utilise the systemic and human resources available. Successful implementation of sustained change depended on strong leadership in the practice and cooperation between team members as well as clear and achievable goals being set. Structured facilitation of teamwork in general practice should focus on goal setting and the development of leadership and communication rather than delivery of information or resources.
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20
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Kalynchuk LE, Davis AC, Gregus A, Taggart J, Chris Dodd C, Wintink AJ, Marchant EG. Hippocampal involvement in the expression of kindling-induced fear in rats. Neurosci Biobehav Rev 2001; 25:687-96. [PMID: 11801294 DOI: 10.1016/s0149-7634(01)00051-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/30/2022]
Abstract
Kindling dramatically increases fearful behavior in rats. Because kindling-induced fear increases in magnitude as rats receive more stimulations, kindling provides a superb opportunity to study the nature and neural mechanisms of fear sensitization. Interestingly, these changes in behavior are accompanied by increased binding to inhibitory receptors and decreased binding to excitatory receptors in the CA1 and dentate gyrus regions of the hippocampus. This led us to hypothesize that kindling-induced fear may result from an increased inhibitory tone within hippocampal circuits. To test this hypothesis, we investigated FOS protein immunoreactivity in hippocampal and amygdalar regions of kindled rats that were exposed to an unfamiliar open field. We found that FOS immunoreactivity was significantly decreased in the CA1 region, dentate gyrus, and perirhinal cortex of kindled rats compared to sham-stimulated rats. These results support our hypothesis that kindling-induced fear may be produced by inhibition within hippocampal circuits. They also suggest that neural changes within the hippocampus may be important for the sensitization of fear.
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Affiliation(s)
- L E Kalynchuk
- Department of Psychology, Life Sciences Center, Dalhousie University, NS, B3H 4J1, Halifax, Canada.
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21
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Yamamoto M, Patel NA, Taggart J, Sridhar R, Cooper DR. A shift from normal to high glucose levels stimulates cell proliferation in drug sensitive MCF-7 human breast cancer cells but not in multidrug resistant MCF-7/ADR cells which overproduce PKC-betaII. Int J Cancer 1999; 83:98-106. [PMID: 10449615 DOI: 10.1002/(sici)1097-0215(19990924)83:1<98::aid-ijc18>3.0.co;2-v] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [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: 11/06/2022]
Abstract
Glucose concentration may be an important factor in breast cancer cell proliferation because the prevalence of breast cancer is high in diabetic patients. To determine the role of protein kinase C (PKC)-betaII in regulating MCF-7 cell proliferation at different glucose concentrations, the effects of glucose and a PKC-betaII-specific inhibitor (CGP53353) were examined in cultures of MCF-7 human breast cancer cell line and its multidrug resistant variant (MCF-7/ADR). Cell proliferation and DNA synthesis of MCF-7 were increased when glucose concentration in the culture medium was increased from normal (5.5 mM) to high (25 mM) levels. However, MCF-7/ADR cell proliferation and DNA synthesis were unaffected by the increase in glucose. PKC-betaII protein and the corresponding mRNA levels were 4- to 5-fold higher in MCF-7/ADR than in MCF-7 cells. High glucose-induced decreases of PKC-betaII protein and mRNA levels were observed during the DNA synthesis phase in MCF-7 but not in MCF-7/ADR cells. Decreases in PKC-betaII mRNA and protein levels below a critical threshold in response to high glucose levels may account for glucose-stimulated proliferation of MCF-7 cells. Cultures of multidrug resistant MCF-7/ADR cells reach maximal cell density in medium containing normal (5.5 mM) glucose levels and are not induced to grow further in response to high (25 mM) glucose. Our results demonstrate a link between high glucose-induced PKC-betaII isozyme down-regulation with concomitant acceleration of cell cycle progression in MCF-7 cells.
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Affiliation(s)
- M Yamamoto
- Department of Biochemistry and Molecular Biology, University of South Florida College of Medicine, Tampa, FL, USA
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22
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Bell S, Taggart J, Karl J, Lind M, Peterman P, Stone K. Implementing a research-based protocol: an interactive approach. AACN Clin Issues Crit Care Nurs 1994; 5:147-51. [PMID: 7767808 DOI: 10.4037/15597768-1994-2006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Endotracheal suctioning (ETS) is a common procedure done in the critical care environment. There are many different practices related to ETS. With the proliferation of research studies about ETS, a change in practice is needed to incorporate these research findings. The authors present a creative teaching strategy that was used to implement a research-based ETS protocol.
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Abstract
A parkinsonian syndrome can be produced in nonhuman primates by administration of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Parkinsonian-like symptoms induced acutely by MPTP were ameliorated after treatment with GM1 ganglioside, a substance shown to have neurotrophic effects on the damaged dopamine system in rodents. Treatment with GM1 ganglioside also increased striatal dopamine and metabolite levels and enhanced the dopaminergic innervation of the striatum as demonstrated by tyrosine hydroxylase immunohistochemistry. These results suggest that GM1 ganglioside may hold promise as a therapeutic agent for the treatment of Parkinson's disease.
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Affiliation(s)
- J S Schneider
- Department of Neurology, Hahnemann University, School of Medicine, Philadelphia, PA 19102
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24
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Schneider JS, Pope A, Simpson K, Taggart J, Smith MG, DiStefano L. Recovery from Experimental Parkinsonism in Primates with GM
1
Ganglioside Treatment. Science 1992. [DOI: 10.1126/science.256.5058.843] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- J. S. Schneider
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
| | - A. Pope
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
| | - K. Simpson
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
| | - J. Taggart
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
| | - M. G. Smith
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
| | - L. DiStefano
- Center for Neurological Research, Department of Neurology, and Institute of Neuroscience, Hahnemann University School of Medicine, Philadelphia, PA 19102
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25
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Platt DJ, Taggart J, Heraghty KA. Molecular divergence of the serotype-specific plasmid (pSLT) among strains of Salmonella typhimurium of human and veterinary origin and comparison of pSLT with the serotype specific plasmids of S. enteritidis and S. dublin. J Med Microbiol 1988; 27:277-84. [PMID: 3058981 DOI: 10.1099/00222615-27-4-277] [Citation(s) in RCA: 26] [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: 01/03/2023] Open
Abstract
Molecular variants of the serotype-specific plasmid (SSP) of Salmonella typhimurium (pSLT) were recognised in clinical and veterinary isolates by restriction enzyme fingerprinting. Three had undergone minor DNA rearrangements, whereas two had acquired resistance determinants to a wide range of antimicrobial agents including gentamicin, trimethoprim, tetracycline, streptomycin, ampicillin (Ap) and kanamycin (Km). One of the latter was the result of co-integrate formation with an IncX, conjugative R-plasmid that specified ApKm resistance. The co-integrate plasmid (pOG669) was incompatible with, and displaced, pSLT and its molecular variants. The restriction fingerprints of SSPs of S. enteritidis and S. dublin were compared with pSLT. All were related at the 35% level on the basis of a Dice coefficient of similarity. The SSPs of S. enteritidis and S. dublin were incompatible with the co-integrate plasmid pOG669. Whereas in S. enteritidis this resulted from incompatibility with the pSLT component (the SSP was compatible with the IncX component), the converse was found with S. dublin.
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Affiliation(s)
- D J Platt
- University Department of Bacteriology, Royal Infirmary, Glasgow
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Platt DJ, Chesham JS, Brown DJ, Kraft CA, Taggart J. Restriction enzyme fingerprinting of enterobacterial plasmids: a simple strategy with wide application. J Hyg (Lond) 1986; 97:205-10. [PMID: 3023479 PMCID: PMC2083545 DOI: 10.1017/s0022172400065281] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Restriction enzyme fingerprints were generated from purified plasmid DNA from 324 clinical isolates that belonged to 7 enterobacterial genera and 88 single plasmids in Escherichia coli K 12 according to the following strategy. Purified plasmid DNA was digested with PstI. The number of fragments detected in a 0.8 agarose gel was used to determine which 2 of 6 restriction enzymes including PstI was most likely to provide a fingerprint comprising sufficient fragments to ensure specificity but sufficiently few to allow easy visual assessment and minimize coincidental matching. When PstI produced greater than 20 fragments, EcoRI and HindIII were used; when PstI generated less than 6 fragments Bsp 1286 and AvaII were used and SmaI was employed when between 6 and 20 fragments were obtained from PstI digests. Using a minimum of 12 fragments from a combination of 2 enzymes as the criterion for characterizing a strain/plasmid, satisfactory 2-enzyme fingerprints were obtained from 87% of the strains and plasmids studied using PstI and no more than two additional enzymes per strain. Of the remaining 54 strains, 51 harboured only small plasmids (less than 10 kb) and 3 produced satisfactory fingerprints when digested with a fourth enzyme.
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Abstract
A home-based behavioral program utilizing contingency contracts and parent-determined rewards was employed in a changing criterion design to modify children's physical activity levels and subsequent measures of health fitness. Children were initially diagnosed as being low in health fitness. Following diagnosis, the child's parents, with support from a trained physical education teacher (parenter), recorded baseline physical activity levels during nonschool hours. During intervention the level of physical activity was systematically increased by setting specific criterion levels of activity for each week. Levels of physical activity increased markedly during the extended 9-12 week intervention phase. Improvements in health fitness criterion measures were recorded. The implications for application and future research involving parents in areas related to physical education were discussed.
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Halbach JW, Taggart J, Palmer K, Coplin T. PHYSIOLOGICAL PROFILE OF PROFESSIONAL HOCKEY PLAYERS. Med Sci Sports Exerc 1985. [DOI: 10.1249/00005768-198504000-00372] [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: 11/21/2022]
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Taggart J. : Quetzalcoatl and the Irony of Empire: Myths and Prophecies in the Aztec Tradition . David Carrasco. American Anthropologist 1985. [DOI: 10.1525/aa.1985.87.1.02a00610] [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: 11/17/2022]
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Dundee JW, Howard AJ, Isaac M, Taggart J, Howard PJ. Alcohol and the Benzodiazepines; The Interaction between Intravenous Ethanol and Chlordiazepoxide and Diazepam. ACTA ACUST UNITED AC 1971. [DOI: 10.15288/qjsa.1971.32.960] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- J. W. Dundee
- Department of Anaesthetics, The Queen's University of Belfast
| | - A. J. Howard
- Department of Forensic Science, Ministry of Commerce, Northern Ireland
| | - M. Isaac
- Department of Anaesthetics, The Queen's University of Belfast
| | - J. Taggart
- Department of Forensic Science, Ministry of Commerce, Northern Ireland
| | - P. J. Howard
- Department of Anaesthetics, The Queen's University of Belfast
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Affiliation(s)
- John W. Dundee
- Department of Anaesthetics, The Queen's University of Belfast, Northern Ireland
| | - M. Isaac
- Department of Anaesthetics, The Queen's University of Belfast, Northern Ireland
| | - J. Taggart
- Department of Forensic Science, Ministry of Commerce, Northern Ireland
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Dundee JW, Isaac M, Taggart J. Blood ethanol levels following rapid intravenous infusion. Q J Stud Alcohol 1971; 32:741-7. [PMID: 5112789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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