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Chandrakasan S, Jordan MB, Baker A, Behrens EM, Bhatla D, Chien M, Eckstein OS, Henry MM, Hermiston ML, Hinson AP, Leiding JW, Oladapo A, Patel SA, Pednekar P, Ray AK, Dávila Saldaña B, Sarangi SN, Walkovich KJ, Yee JD, Zoref-Lorenz A, Allen CE. Real-world treatment patterns and outcomes in patients with primary hemophagocytic lymphohistiocytosis treated with emapalumab. Blood Adv 2024; 8:2248-2258. [PMID: 38429096 DOI: 10.1182/bloodadvances.2023012217] [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] [Received: 11/27/2023] [Revised: 01/19/2024] [Accepted: 02/09/2024] [Indexed: 03/03/2024] Open
Abstract
ABSTRACT Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening, hyperinflammatory syndrome. Emapalumab, a fully human monoclonal antibody that neutralizes the proinflammatory cytokine interferon gamma, is approved in the United States to treat primary HLH (pHLH) in patients with refractory, recurrent, or progressive disease, or intolerance with conventional HLH treatments. REAL-HLH, a retrospective study, conducted across 33 US hospitals, evaluated real-world treatment patterns and outcomes in patients treated with ≥1 dose of emapalumab between 20 November 2018 and 31 October 2021. In total, 46 patients met the pHLH classification criteria. Median age at diagnosis was 1.0 year (range, 0.3-21.0). Emapalumab was initiated for treating refractory (19/46), recurrent (14/46), or progressive (7/46) pHLH. At initiation, 15 of 46 patients were in the intensive care unit, and 35 of 46 had received prior HLH-related therapies. Emapalumab treatment resulted in normalization of key laboratory parameters, including chemokine ligand 9 (24/33, 72.7%), ferritin (20/45, 44.4%), fibrinogen (37/38, 97.4%), platelets (39/46, 84.8%), and absolute neutrophil count (40/45, 88.9%). Forty-two (91.3%) patients were considered eligible for transplant. Pretransplant survival was 38 of 42 (90.5%). Thirty-one (73.8%) transplant-eligible patients proceeded to transplant, and 23 of 31 (74.2%) of those who received transplant were alive at the end of the follow-up period. Twelve-month survival probability from emapalumab initiation for the entire cohort (N = 46) was 73.1%. There were no discontinuations because of adverse events. In conclusion, results from the REAL-HLH study, which describes treatment patterns, effectiveness, and outcomes in patients with pHLH treated with emapalumab in real-world settings, are consistent with the emapalumab pivotal phase 2/3 pHLH trial.
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Affiliation(s)
- Shanmuganathan Chandrakasan
- Division of Bone Marrow Transplant, Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Emory University, Atlanta, GA
| | - Michael B Jordan
- Division of Bone Marrow Transplantation and Immune Deficiency, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
| | - Ashley Baker
- Department of Pediatrics, Division of Hematology Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Edward M Behrens
- Division of Rheumatology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Deepika Bhatla
- Department of Pediatric Hematology Oncology, Saint Louis University, St. Louis, MO
| | - May Chien
- Department of Hematology-Oncology, Lucile Packard Children's Hospital at Stanford University, Palo Alto, CA
| | - Olive S Eckstein
- Division of Pediatric Hematology and Oncology, Baylor College of Medicine, Houston, TX
| | - Michael M Henry
- Department of Pediatric Hematology-Oncology, Phoenix Children's, Phoenix, AZ
| | - Michelle L Hermiston
- Department of Pediatric Hematology-Oncology, University of California San Francisco, San Francisco, CA
| | - Ashley P Hinson
- Department of Pediatric Hematology-Oncology, Atrium Health, Levine Children's Hospital, Charlotte, NC
| | - Jennifer W Leiding
- Division of Allergy and Immunology, Department of Pediatrics, Johns Hopkins University, Baltimore, MD
| | | | - Sachit A Patel
- Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE
| | | | - Anish K Ray
- Department of Pediatric Hematology-Oncology, Cook Children's Medical Center, Fort Worth, TX
| | - Blachy Dávila Saldaña
- Division of Blood and Marrow Transplantation, Children's National Medical Center, Washington, DC
| | - Susmita N Sarangi
- Department of Pediatric Hematology-Oncology, MedStar Georgetown University Hospital, Washington, DC
| | - Kelly J Walkovich
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI
| | | | - Adi Zoref-Lorenz
- Division of Bone Marrow Transplantation and Immune Deficiency, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
- Division of Hematology, Hematology Institute, Meir Medical Center, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Carl E Allen
- Division of Pediatric Hematology and Oncology, Baylor College of Medicine, Houston, TX
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Bielamowicz K, Dimitrion P, Abla O, Bomken S, Campbell P, Collin M, Degar B, Diamond EL, Eckstein OS, El-Mallawany N, Fluchel M, Goyal G, Henry MM, Hermiston M, Hogarty M, Jeng M, Jubran R, Lubega J, Kumar A, Ladisch S, McClain KL, Merad M, Mi QS, Parsons DW, Peckham-Gregory E, Picarsic J, Prudowsky ZD, Rollins BJ, Shaw PH, Wistinghausen B, Rodriguez-Galindo C, Allen CE. Langerhans cell histiocytosis: NACHO update on progress, chaos, and opportunity on the path to rational cures. Cancer 2024. [PMID: 38687639 DOI: 10.1002/cncr.35301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/14/2024] [Accepted: 02/27/2024] [Indexed: 05/02/2024]
Abstract
Langerhans cell histiocytosis (LCH) is a myeloid neoplastic disorder characterized by lesions with CD1a-positive/Langerin (CD207)-positive histiocytes and inflammatory infiltrate that can cause local tissue damage and systemic inflammation. Clinical presentations range from single lesions with minimal impact to life-threatening disseminated disease. Therapy for systemic LCH has been established through serial trials empirically testing different chemotherapy agents and durations of therapy. However, fewer than 50% of patients who have disseminated disease are cured with the current standard-of-care vinblastine/prednisone/(mercaptopurine), and treatment failure is associated with long-term morbidity, including the risk of LCH-associated neurodegeneration. Historically, the nature of LCH-whether a reactive condition versus a neoplastic/malignant condition-was uncertain. Over the past 15 years, seminal discoveries have broadly defined LCH pathogenesis; specifically, activating mitogen-activated protein kinase pathway mutations (most frequently, BRAFV600E) in myeloid precursors drive lesion formation. LCH therefore is a clonal neoplastic disorder, although secondary inflammatory features contribute to the disease. These paradigm-changing insights offer a promise of rational cures for patients based on individual mutations, clonal reservoirs, and extent of disease. However, the pace of clinical trial development behind lags the kinetics of translational discovery. In this review, the authors discuss the current understanding of LCH biology, clinical characteristics, therapeutic strategies, and opportunities to improve outcomes for every patient through coordinated agent prioritization and clinical trial efforts.
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Affiliation(s)
- Kevin Bielamowicz
- Department of Pediatrics, College of Medicine at the University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Pediatric Hematology and Oncology, Arkansas Children's Hospital, Little Rock, Arkansas, USA
| | - Peter Dimitrion
- Center for Cutaneous Biology and Immunology, Henry Ford Health, Detroit, Michigan, USA
| | - Oussama Abla
- Division of Hematology/Oncology, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Simon Bomken
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Patrick Campbell
- Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew Collin
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- National Institute for Health and Care Research, Newcastle Biomedical Research Center, Newcastle upon Tyne, United Kingdom
| | - Barbara Degar
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Eli L Diamond
- Departments of Neurology and Medicine, Memorial Sloan Kettering Center, New York, New York, USA
| | - Olive S Eckstein
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Nader El-Mallawany
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Mark Fluchel
- Division of Pediatric Hematology/Oncology, Department of Pediatrics, Seattle Children's Hospital and University of Washington School of Medicine, Seattle, Washington, USA
| | - Gaurav Goyal
- Division of Hematology-Oncology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael M Henry
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Michelle Hermiston
- Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA
| | - Michael Hogarty
- Division of Hematology and Oncology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Michael Jeng
- Department of Pediatrics, Pediatric Hematology/Oncology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California, USA
| | - Rima Jubran
- Division of Pediatric Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Joseph Lubega
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Ashish Kumar
- Division of Bone Marrow Transplant and Immune Deficiency, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Stephan Ladisch
- Center for Cancer and Immunology Research, Children's National Medical Center and George Washington University School of Medicine, Washington, District of Columbia, USA
| | - Kenneth L McClain
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Miriam Merad
- Marc and Jennifer Lipschultz Precision Immunology Institute, New York, New York, USA
- The Tisch Cancer Institute, New York, New York, USA
- Department of Oncology Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Qing-Sheng Mi
- Center for Cutaneous Biology and Immunology, Henry Ford Health, Detroit, Michigan, USA
| | - D Williams Parsons
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Erin Peckham-Gregory
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Jennifer Picarsic
- University of Cincinnati College of Medicine and Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Zachary D Prudowsky
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
| | - Barrett J Rollins
- Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter H Shaw
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Birte Wistinghausen
- Center for Cancer and Immunology Research, Children's National Medical Center and George Washington University School of Medicine, Washington, District of Columbia, USA
| | - Carlos Rodriguez-Galindo
- Department of Global Pediatric Medicine and Department of Oncology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Carl E Allen
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
- Texas Children's Cancer Center, Texas Children's Hospital, Houston, Texas, USA
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Ries B, Alibay I, Swenson DWH, Baumann HM, Henry MM, Eastwood JRB, Gowers RJ. Kartograf: A Geometrically Accurate Atom Mapper for Hybrid-Topology Relative Free Energy Calculations. J Chem Theory Comput 2024; 20:1862-1877. [PMID: 38330251 PMCID: PMC10941767 DOI: 10.1021/acs.jctc.3c01206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 02/10/2024]
Abstract
Relative binding free energy (RBFE) calculations have emerged as a powerful tool that supports ligand optimization in drug discovery. Despite many successes, the use of RBFEs can often be limited by automation problems, in particular, the setup of such calculations. Atom mapping algorithms are an essential component in setting up automatic large-scale hybrid-topology RBFE calculation campaigns. Traditional algorithms typically employ a 2D subgraph isomorphism solver (SIS) in order to estimate the maximum common substructure. SIS-based approaches can be limited by time-intensive operations and issues with capturing geometry-linked chemical properties, potentially leading to suboptimal solutions. To overcome these limitations, we have developed Kartograf, a geometric-graph-based algorithm that uses primarily the 3D coordinates of atoms to find a mapping between two ligands. In free energy approaches, the ligand conformations are usually derived from docking or other previous modeling approaches, giving the coordinates a certain importance. By considering the spatial relationships between atoms related to the molecule coordinates, our algorithm bypasses the computationally complex subgraph matching of SIS-based approaches and reduces the problem to a much simpler bipartite graph matching problem. Moreover, Kartograf effectively circumvents typical mapping issues induced by molecule symmetry and stereoisomerism, making it a more robust approach for atom mapping from a geometric perspective. To validate our method, we calculated mappings with our novel approach using a diverse set of small molecules and used the mappings in relative hydration and binding free energy calculations. The comparison with two SIS-based algorithms showed that Kartograf offers a fast alternative approach. The code for Kartograf is freely available on GitHub (https://github.com/OpenFreeEnergy/kartograf). While developed for the OpenFE ecosystem, Kartograf can also be utilized as a standalone Python package.
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Affiliation(s)
- Benjamin Ries
- Medicinal
Chemistry, Boehringer Ingelheim Pharma GmbH
& Co KG, Birkendorfer Str 65, 88397 Biberach an der Riss, Germany
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
| | - Irfan Alibay
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
| | - David W. H. Swenson
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
| | - Hannah M. Baumann
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
| | - Michael M. Henry
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
- Computational
and Systems Biology Program, Sloan Kettering
Institute, Memorial Sloan Kettering Cancer Center, New York, 1275 New York, United States
| | - James R. B. Eastwood
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
| | - Richard J. Gowers
- Open
Free Energy, Open Molecular Software Foundation, Davis, 95616 California, United States
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4
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Luong H, Cornejo P, Henry MM, Ramasubramanian A. Leukemic Optic Neuropathy. J Neuroophthalmol 2024:00041327-990000000-00558. [PMID: 38271193 DOI: 10.1097/wno.0000000000002094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
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5
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Zhang I, Rufa DA, Pulido I, Henry MM, Rosen LE, Hauser K, Singh S, Chodera JD. Correction to Identifying and Overcoming the Sampling Challenges in Relative Binding Free Energy Calculations of a Model Protein:Protein Complex. J Chem Theory Comput 2024; 20:990-991. [PMID: 38164914 DOI: 10.1021/acs.jctc.3c01298] [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: 01/03/2024]
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6
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Eastman P, Galvelis R, Peláez RP, Abreu CRA, Farr SE, Gallicchio E, Gorenko A, Henry MM, Hu F, Huang J, Krämer A, Michel J, Mitchell JA, Pande VS, Rodrigues JPGLM, Rodriguez-Guerra J, Simmonett AC, Singh S, Swails J, Turner P, Wang Y, Zhang I, Chodera JD, De Fabritiis G, Markland TE. OpenMM 8: Molecular Dynamics Simulation with Machine Learning Potentials. J Phys Chem B 2024; 128:109-116. [PMID: 38154096 PMCID: PMC10846090 DOI: 10.1021/acs.jpcb.3c06662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2023]
Abstract
Machine learning plays an important and growing role in molecular simulation. The newest version of the OpenMM molecular dynamics toolkit introduces new features to support the use of machine learning potentials. Arbitrary PyTorch models can be added to a simulation and used to compute forces and energy. A higher-level interface allows users to easily model their molecules of interest with general purpose, pretrained potential functions. A collection of optimized CUDA kernels and custom PyTorch operations greatly improves the speed of simulations. We demonstrate these features in simulations of cyclin-dependent kinase 8 (CDK8) and the green fluorescent protein chromophore in water. Taken together, these features make it practical to use machine learning to improve the accuracy of simulations with only a modest increase in cost.
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Affiliation(s)
- Peter Eastman
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Raimondas Galvelis
- Acellera Labs, C Dr Trueta 183, 08005, Barcelona, Spain
- Computational Science Laboratory, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Raúl P. Peláez
- Computational Science Laboratory, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Charlles R. A. Abreu
- Chemical Engineering Department, School of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro 68542, Brazil
- Redesign Science Inc., 180 Varick St., New York, NY 10014, USA
| | - Stephen E. Farr
- EaStCHEM School of Chemistry, University of Edinburgh, EH9 3FJ, United Kingdom
| | - Emilio Gallicchio
- Department of Chemistry and Biochemistry, Brooklyn College of the City University of New York, NY, USA
- Ph.D. Program in Chemistry and Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY, USA
| | - Anton Gorenko
- Stream HPC, Koningin Wilhelminaplein 1 - 40601, 1062 HG Amsterdam, Netherlands
| | - Michael M. Henry
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York NY 10065, USA
| | - Frank Hu
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Andreas Krämer
- Department of Mathematics and Computer Science, Freie Universität Berlin, Arnimallee 12, 14195 Berlin, Germany
| | - Julien Michel
- EaStCHEM School of Chemistry, University of Edinburgh, EH9 3FJ, United Kingdom
| | - Joshua A. Mitchell
- The Open Force Field Initiative, Open Molecular Software Foundation, Davis, CA 95616, USA
| | - Vijay S. Pande
- Andreessen Horowitz, 2865 Sand Hill Rd, Menlo Park, CA 94025, USA
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - João PGLM Rodrigues
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Jaime Rodriguez-Guerra
- Charité Universitätsmedizin Berlin In silico Toxicology and Structural Bioinformatics, Virchowweg 6, 10117 Berlin, Germany
| | - Andrew C. Simmonett
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sukrit Singh
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York NY 10065, USA
| | - Jason Swails
- Entos Inc., 9310 Athena Circle, La Jolla, CA 92037, USA
| | - Philip Turner
- College of Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Yuanqing Wang
- Simons Center for Computational Physical Chemistry and Center for Data Science, New York University, 24 Waverly Place, New York, NY 10004, USA
| | - Ivy Zhang
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York NY 10065, USA
- Tri-Institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medical College, Cornell University, New York, NY 10065, USA
| | - John D. Chodera
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York NY 10065, USA
| | - Gianni De Fabritiis
- Acellera Labs, C Dr Trueta 183, 08005, Barcelona, Spain
- Computational Science Laboratory, Universitat Pompeu Fabra, Barcelona Biomedical Research Park (PRBB), C Dr. Aiguader 88, 08003, Barcelona, Spain
- ICREA, Passeig Lluis Companys 23, 08010, Barcelona, Spain
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7
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Eastman P, Galvelis R, Peláez RP, Abreu CRA, Farr SE, Gallicchio E, Gorenko A, Henry MM, Hu F, Huang J, Krämer A, Michel J, Mitchell JA, Pande VS, Rodrigues JP, Rodriguez-Guerra J, Simmonett AC, Singh S, Swails J, Turner P, Wang Y, Zhang I, Chodera JD, Fabritiis GD, Markland TE. OpenMM 8: Molecular Dynamics Simulation with Machine Learning Potentials. ArXiv 2023:arXiv:2310.03121v2. [PMID: 37986730 PMCID: PMC10659447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Machine learning plays an important and growing role in molecular simulation. The newest version of the OpenMM molecular dynamics toolkit introduces new features to support the use of machine learning potentials. Arbitrary PyTorch models can be added to a simulation and used to compute forces and energy. A higher-level interface allows users to easily model their molecules of interest with general purpose, pretrained potential functions. A collection of optimized CUDA kernels and custom PyTorch operations greatly improves the speed of simulations. We demonstrate these features on simulations of cyclin-dependent kinase 8 (CDK8) and the green fluorescent protein (GFP) chromophore in water. Taken together, these features make it practical to use machine learning to improve the accuracy of simulations at only a modest increase in cost.
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8
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Zhang I, Rufa DA, Pulido I, Henry MM, Rosen LE, Hauser K, Singh S, Chodera JD. Identifying and Overcoming the Sampling Challenges in Relative Binding Free Energy Calculations of a Model Protein:Protein Complex. J Chem Theory Comput 2023; 19:4863-4882. [PMID: 37450482 DOI: 10.1021/acs.jctc.3c00333] [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: 07/18/2023]
Abstract
Relative alchemical binding free energy calculations are routinely used in drug discovery projects to optimize the affinity of small molecules for their drug targets. Alchemical methods can also be used to estimate the impact of amino acid mutations on protein:protein binding affinities, but these calculations can involve sampling challenges due to the complex networks of protein and water interactions frequently present in protein:protein interfaces. We investigate these challenges by extending a graphics processing unit (GPU)-accelerated open-source relative free energy calculation package (Perses) to predict the impact of amino acid mutations on protein:protein binding. Using the well-characterized model system barnase:barstar, we describe analyses for identifying and characterizing sampling problems in protein:protein relative free energy calculations. We find that mutations with sampling problems often involve charge-changes, and inadequate sampling can be attributed to slow degrees of freedom that are mutation-specific. We also explore the accuracy and efficiency of current state-of-the-art approaches─alchemical replica exchange and alchemical replica exchange with solute tempering─for overcoming relevant sampling problems. By employing sufficiently long simulations, we achieve accurate predictions (RMSE 1.61, 95% CI: [1.12, 2.11] kcal/mol), with 86% of estimates within 1 kcal/mol of the experimentally determined relative binding free energies and 100% of predictions correctly classifying the sign of the changes in binding free energies. Ultimately, we provide a model workflow for applying protein mutation free energy calculations to protein:protein complexes, and importantly, catalog the sampling challenges associated with these types of alchemical transformations. Our free open-source package (Perses) is based on OpenMM and is available at https://github.com/choderalab/perses.
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Affiliation(s)
- Ivy Zhang
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Tri-Institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medical College, Cornell University, New York, New York 10065, United States
| | - Dominic A Rufa
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
- Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medical College, Cornell University, New York, New York 10065, United States
| | - Iván Pulido
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Michael M Henry
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Laura E Rosen
- Vir Biotechnology, San Francisco, California 94158, United States
| | - Kevin Hauser
- Vir Biotechnology, San Francisco, California 94158, United States
| | - Sukrit Singh
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - John D Chodera
- Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
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9
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Zhang I, Rufa DA, Pulido I, Henry MM, Rosen LE, Hauser K, Singh S, Chodera JD. Identifying and overcoming the sampling challenges in relative binding free energy calculations of a model protein:protein complex. bioRxiv 2023:2023.03.07.530278. [PMID: 36945557 PMCID: PMC10028896 DOI: 10.1101/2023.03.07.530278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Relative alchemical binding free energy calculations are routinely used in drug discovery projects to optimize the affinity of small molecules for their drug targets. Alchemical methods can also be used to estimate the impact of amino acid mutations on protein:protein binding affinities, but these calculations can involve sampling challenges due to the complex networks of protein and water interactions frequently present in protein:protein interfaces. We investigate these challenges by extending a GPU-accelerated opensource relative free energy calculation package (Perses) to predict the impact of amino acid mutations on protein:protein binding. Using the well-characterized model system barnase:barstar, we describe analyses for identifying and characterizing sampling problems in protein:protein relative free energy calculations. We find that mutations with sampling problems often involve charge-changes, and inadequate sampling can be attributed to slow degrees of freedom that are mutation-specific. We also explore the accuracy and efficiency of current state-of-the-art approaches-alchemical replica exchange and alchemical replica exchange with solute tempering-for overcoming relevant sampling problems. By employing sufficiently long simulations, we achieve accurate predictions (RMSE 1.61, 95% CI: [1.12, 2.11] kcal/mol), with 86% of estimates within 1 kcal/mol of the experimentally-determined relative binding free energies and 100% of predictions correctly classifying the sign of the changes in binding free energies. Ultimately, we provide a model workflow for applying protein mutation free energy calculations to protein:protein complexes, and importantly, catalog the sampling challenges associated with these types of alchemical transformations. Our free open-source package (Perses) is based on OpenMM and available at https://github.com/choderalab/perses .
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Kemps PG, Picarsic J, Durham BH, Hélias-Rodzewicz Z, Hiemcke-Jiwa L, van den Bos C, van de Wetering MD, van Noesel CJM, van Laar JAM, Verdijk RM, Flucke UE, Hogendoorn PCW, Woei-A-Jin FJSH, Sciot R, Beilken A, Feuerhake F, Ebinger M, Möhle R, Fend F, Bornemann A, Wiegering V, Ernestus K, Méry T, Gryniewicz-Kwiatkowska O, Dembowska-Baginska B, Evseev DA, Potapenko V, Baykov VV, Gaspari S, Rossi S, Gessi M, Tamburrini G, Héritier S, Donadieu J, Bonneau-Lagacherie J, Lamaison C, Farnault L, Fraitag S, Jullié ML, Haroche J, Collin M, Allotey J, Madni M, Turner K, Picton S, Barbaro PM, Poulin A, Tam IS, El Demellawy D, Empringham B, Whitlock JA, Raghunathan A, Swanson AA, Suchi M, Brandt JM, Yaseen NR, Weinstein JL, Eldem I, Sisk BA, Sridhar V, Atkinson M, Massoth LR, Hornick JL, Alexandrescu S, Yeo KK, Petrova-Drus K, Peeke SZ, Muñoz-Arcos LS, Leino DG, Grier DD, Lorsbach R, Roy S, Kumar AR, Garg S, Tiwari N, Schafernak KT, Henry MM, van Halteren AGS, Abla O, Diamond EL, Emile JF. ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition. Blood 2022; 139:256-280. [PMID: 34727172 PMCID: PMC8759533 DOI: 10.1182/blood.2021013338] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/18/2021] [Indexed: 11/20/2022] Open
Abstract
ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in 3 infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALK rearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (7 and 12 from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one-third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated extracellular signal-regulated kinase, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, whereas CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK, and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, 10 with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis and provides guidance for the clinical management of this emerging histiocytic entity.
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Affiliation(s)
- Paul G Kemps
- Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Jennifer Picarsic
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Benjamin H Durham
- Human Oncology and Pathogenesis Program, Department of Medicine, and
- Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Zofia Hélias-Rodzewicz
- Department of Pathology, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne, France
- EA4340-Biomarqueurs et Essais Cliniques en Cancérologie et Onco-Hématologie, Versailles Saint-Quentin-en-Yvelines University, Boulogne, France
| | | | - Cor van den Bos
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pediatric Oncology, Emma Children's Hospital, and
| | - Marianne D van de Wetering
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pediatric Oncology, Emma Children's Hospital, and
| | - Carel J M van Noesel
- Department of Pathology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Jan A M van Laar
- Department of Internal Medicine and Immunology, and
- Section of Clinical Immunology, Department of Immunology, and
| | - Robert M Verdijk
- Department of Pathology, Erasmus Medical Center University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Uta E Flucke
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - F J Sherida H Woei-A-Jin
- Department of General Medical Oncology, University Hospitals Leuven, Leuven Cancer Institute, Leuven, Belgium
| | - Raf Sciot
- Department of Pathology, University Hospitals Leuven, Katholieke Universiteit Leuven, Leuven, Belgium
| | | | | | - Martin Ebinger
- Department I - General Pediatrics, Children's Hospital, Hematology and Oncology
| | | | - Falko Fend
- Department of Pathology and Neuropathology and Comprehensive Cancer Center, University Hospital Tuebingen, Tuebingen, Germany
| | - Antje Bornemann
- Department of Pathology and Neuropathology and Comprehensive Cancer Center, University Hospital Tuebingen, Tuebingen, Germany
| | - Verena Wiegering
- Department of Oncology, Hematology and Stem Cell Transplantation, University Children's Hospital Würzburg, Würzburg, Germany
| | - Karen Ernestus
- Department of Pathology, University of Würzburg and Comprehensive Cancer Center Mainfranken, Würzburg, Germany
| | - Tina Méry
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, Klinikum Chemnitz, Chemnitz, Germany
| | | | | | - Dmitry A Evseev
- Dmitriy Rogachev National Center for Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - Vsevolod Potapenko
- Department of Hematology and Oncology, Municipal Educational Hospital N°31, Saint Petersburg, Russia
- Department of Bone Marrow Transplantation and
| | - Vadim V Baykov
- Department of Pathology, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
| | - Stefania Gaspari
- Department of Hematology/Oncology, Cell and Gene Therapy, Bambino Gesù Children's Hospital Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy
| | - Sabrina Rossi
- Pathology Unit, Laboratories Department, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | | | - Gianpiero Tamburrini
- Department of Pediatric Neurosurgery, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Sébastien Héritier
- Department of Pediatric Hematology and Oncology, Trousseau Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean Donadieu
- EA4340-Biomarqueurs et Essais Cliniques en Cancérologie et Onco-Hématologie, Versailles Saint-Quentin-en-Yvelines University, Boulogne, France
- Department of Pediatric Hematology and Oncology, Trousseau Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | | | - Claire Lamaison
- Department of Pathology, Rennes University Hospital, Rennes, France
| | - Laure Farnault
- Department of Hematology, La Conception, University Hospital of Marseille, Marseille, France
| | - Sylvie Fraitag
- Department of Pathology, Necker-Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Marie-Laure Jullié
- Department of Pathology, University Hospital of Bordeaux, Bordeaux, France
| | - Julien Haroche
- Department of Internal Medicine, University Hospital La Pitié-Salpêtrière Paris, French National Reference Center for Histiocytoses, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Matthew Collin
- Newcastle upon Tyne Hospitals, Newcastle upon Tyne, United Kingdom
| | | | - Majid Madni
- Department of Pediatric Hematology and Oncology, Nottingham University Hospitals, Nottingham, United Kingdom
| | | | - Susan Picton
- Department of Pediatric Oncology, Leeds Children's Hospital, Leeds, United Kingdom
| | - Pasquale M Barbaro
- Department of Hematology, Queensland Children's Hospital, Brisbane, QLD, Australia
| | - Alysa Poulin
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ingrid S Tam
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Dina El Demellawy
- Department of Pathology, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - Brianna Empringham
- Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - James A Whitlock
- Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | | | - Amy A Swanson
- Division of Anatomic Pathology, Mayo Clinic Rochester, Rochester, MN
| | - Mariko Suchi
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI
| | - Jon M Brandt
- Department of Pediatric Oncology, Hospital Sisters Health System St Vincent Children's Hospital, Green Bay, WI
| | - Nabeel R Yaseen
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Joanna L Weinstein
- Department of Hematology, Oncology and Stem Cell Transplantation, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Irem Eldem
- Department of Pediatric Hematology and Oncology, St Louis Children's Hospital, Washington University in St Louis, St Louis, MO
| | - Bryan A Sisk
- Department of Pediatric Hematology and Oncology, St Louis Children's Hospital, Washington University in St Louis, St Louis, MO
| | - Vaishnavi Sridhar
- Department of Pediatric Hematology and Oncology, Carilion Children's Pediatric Hematology and Oncology, Roanoke, VA
| | - Mandy Atkinson
- Department of Pediatric Hematology and Oncology, Carilion Children's Pediatric Hematology and Oncology, Roanoke, VA
| | - Lucas R Massoth
- Department of Pathology, Massachusetts General Hospital, and
| | - Jason L Hornick
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Sanda Alexandrescu
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
- Department of Pathology, Boston Children's Hospital, Boston, MA
| | - Kee Kiat Yeo
- Department of Pediatric Oncology, Dana Farber/Boston Children's Cancer and Blood Disorders Center, Boston, MA
| | | | - Stephen Z Peeke
- Department of Hematology and Medical Oncology, Maimonides Medical Center, Brooklyn, NY
| | - Laura S Muñoz-Arcos
- Department of Internal Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY
| | - Daniel G Leino
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - David D Grier
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Robert Lorsbach
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Somak Roy
- Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Ashish R Kumar
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH
- Division of Bone Marrow Transplantation and Immune Deficiency, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | | | | | | | - Michael M Henry
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, AZ
| | - Astrid G S van Halteren
- Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
- Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands; and
| | - Oussama Abla
- Department of Hematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Eli L Diamond
- Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY
| | - Jean-François Emile
- Department of Pathology, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne, France
- EA4340-Biomarqueurs et Essais Cliniques en Cancérologie et Onco-Hématologie, Versailles Saint-Quentin-en-Yvelines University, Boulogne, France
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11
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Goode E, Smith JA, Gilpatrick M, Matney C, Borch-Christensen B, Henry MM. Autoimmune lymphoproliferative syndrome with Langerhans cell histiocytosis diagnosis. Pediatr Blood Cancer 2022; 69:e29301. [PMID: 34398530 DOI: 10.1002/pbc.29301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Erin Goode
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona, USA
| | - Jaron A Smith
- Department of Pediatrics, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Maryam Gilpatrick
- Department of Pediatrics, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Chelsea Matney
- Department of Pediatrics, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Bo Borch-Christensen
- Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona, USA.,Department of Hospital Medicine, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Michael M Henry
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona, USA.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona, USA
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12
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Chaturvedi V, Marsh RA, Zoref-Lorenz A, Owsley E, Chaturvedi V, Nguyen TC, Goldman JR, Henry MM, Greenberg JN, Ladisch S, Hermiston ML, Jeng M, Naqvi A, Allen CE, Wong HR, Jordan MB. T-cell activation profiles distinguish hemophagocytic lymphohistiocytosis and early sepsis. Blood 2021; 137:2337-2346. [PMID: 33512385 PMCID: PMC8085480 DOI: 10.1182/blood.2020009499] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/25/2020] [Indexed: 12/18/2022] Open
Abstract
Hemophagocytic lymphohistiocytosis (HLH) is a fatal disorder of immune hyperactivation that has been described as a cytokine storm. Sepsis due to known or suspected infection has also been viewed as a cytokine storm. Although clinical similarities between these syndromes suggest similar immunopathology and may create diagnostic uncertainty, distinguishing them is critical as treatments are widely divergent. We examined T-cell profiles from children with either HLH or sepsis and found that HLH is characterized by acute T-cell activation, in clear contrast to sepsis. Activated T cells in patients with HLH were characterized as CD38high/HLA-DR+ effector cells, with activation of CD8+ T cells being most pronounced. Activated T cells were type 1 polarized, proliferative, and displayed evidence of recent and persistent activation. Circulating activated T cells appeared to be broadly characteristic of HLH, as they were seen in children with and without genetic lesions or identifiable infections and resolved with conventional treatment of HLH. Furthermore, we observed even greater activation and type 1 polarization in tissue-infiltrating T cells, described here for the first time in a series of patients with HLH. Finally, we observed that a threshold of >7% CD38high/HLA-DR+ cells among CD8+ T cells had strong positive and negative predictive value for distinguishing HLH from early sepsis or healthy controls. We conclude that the cytokine storm of HLH is marked by distinctive T-cell activation whereas early sepsis is not, and that these 2 syndromes can be readily distinguished by T-cell phenotypes.
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Affiliation(s)
- Vandana Chaturvedi
- Division of Immunobiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH
| | - Rebecca A Marsh
- Division of Bone Marrow Transplantation and Immune Deficiency, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Adi Zoref-Lorenz
- Division of Immunobiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH
- Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Erika Owsley
- Division of Bone Marrow Transplantation and Immune Deficiency, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Vijaya Chaturvedi
- Division of Bone Marrow Transplantation and Immune Deficiency, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Trung C Nguyen
- Section of Critical Care, Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - Jordana R Goldman
- Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey VA Medical Center, Houston, TX
| | - Michael M Henry
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, AZ
| | - Jay N Greenberg
- Division of Hematology, Department of Pediatrics, Children's National Hospital, Washington, DC
| | - Stephan Ladisch
- Division of Hematology, Department of Pediatrics, Children's National Hospital, Washington, DC
| | - Michelle L Hermiston
- Division of Hematology Oncology, Department of Pediatrics, UCSF School of Medicine, San Francisco, CA
| | - Michael Jeng
- Hematology and Oncology, Department of Pediatrics, Stanford Medical School, Stanford, CA
| | - Ahmed Naqvi
- Department of Pediatrics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Carl E Allen
- Section of Hematology/Oncology, Department of Pediatrics, Baylor College of Medicine, Houston, TX; and
| | - Hector R Wong
- Division of Critical Care, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Michael B Jordan
- Division of Immunobiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH
- Division of Bone Marrow Transplantation and Immune Deficiency, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
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13
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McInnis-Smith K, Mansueto LA, Schafernak K, Jacobsen J, Henry MM, Ramasubramanian A. Isolated optic nerve leukemic relapse diagnosed via fine needle aspiration biopsy and transconjunctival biopsy. Pediatr Blood Cancer 2021; 68:e28684. [PMID: 32886399 DOI: 10.1002/pbc.28684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Michael M Henry
- Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona
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14
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Henry MM, Thomas S, Alberts M, Estridge CE, Farmer B, McNair O, Jankowski E. General-Purpose Coarse-Grained Toughened Thermoset Model for 44DDS/DGEBA/PES. Polymers (Basel) 2020; 12:polym12112547. [PMID: 33143261 PMCID: PMC7693565 DOI: 10.3390/polym12112547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/23/2020] [Accepted: 10/23/2020] [Indexed: 12/26/2022] Open
Abstract
The objective of this work is to predict the morphology and material properties of crosslinking polymers used in aerospace applications. We extend the open-source dybond plugin for HOOMD-Blue to implement a new coarse-grained model of reacting epoxy thermosets and use the 44DDS/DGEBA/PES system as a case study for calibration and validation. We parameterize the coarse-grained model from atomistic solubility data, calibrate reaction dynamics against experiments, and check for size-dependent artifacts. We validate model predictions by comparing glass transition temperatures measurements at arbitrary degree of cure, gel-points, and morphology predictions against experiments. We demonstrate for the first time in molecular simulations the cure-path dependence of toughened thermoset morphologies.
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Affiliation(s)
- Michael M. Henry
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA; (M.M.H.); (S.T.); (M.A.)
| | - Stephen Thomas
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA; (M.M.H.); (S.T.); (M.A.)
| | - Mone’t Alberts
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA; (M.M.H.); (S.T.); (M.A.)
| | | | | | - Olivia McNair
- The Boeing Company, St. Louis, MO 63134, USA; (C.E.E.); (O.M.)
| | - Eric Jankowski
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA; (M.M.H.); (S.T.); (M.A.)
- Correspondence:
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15
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Miller ED, Jones ML, Henry MM, Chery P, Miller K, Jankowski E. Optimization and Validation of Efficient Models for Predicting Polythiophene Self-Assembly. Polymers (Basel) 2018; 10:E1305. [PMID: 30961230 PMCID: PMC6401914 DOI: 10.3390/polym10121305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 01/27/2023] Open
Abstract
We develop an optimized force-field for poly(3-hexylthiophene) (P3HT) and demonstrate its utility for predicting thermodynamic self-assembly. In particular, we consider short oligomer chains, model electrostatics and solvent implicitly, and coarsely model solvent evaporation. We quantify the performance of our model to determine what the optimal system sizes are for exploring self-assembly at combinations of state variables. We perform molecular dynamics simulations to predict the self-assembly of P3HT at ∼350 combinations of temperature and solvent quality. Our structural calculations predict that the highest degrees of order are obtained with good solvents just below the melting temperature. We find our model produces the most accurate structural predictions to date, as measured by agreement with grazing incident X-ray scattering experiments.
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Affiliation(s)
- Evan D Miller
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83705, USA.
| | - Matthew L Jones
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83705, USA.
| | - Michael M Henry
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83705, USA.
| | - Paul Chery
- Physics, Macalester College, St. Paul, MN 55105, USA.
| | - Kyle Miller
- Physics, University of Puget Sound, Tacoma, WA 98416, USA.
| | - Eric Jankowski
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83705, USA.
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16
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Azorsa DO, Lee DW, Wai DH, Bista R, Patel AR, Aleem E, Henry MM, Arceci RJ. Clinical resistance associated with a novel MAP2K1 mutation in a patient with Langerhans cell histiocytosis. Pediatr Blood Cancer 2018; 65:e27237. [PMID: 29768711 DOI: 10.1002/pbc.27237] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/13/2018] [Accepted: 04/17/2018] [Indexed: 01/18/2023]
Abstract
Patients with Langerhans cell histiocytosis (LCH) harbor BRAF V600E and activating mutations of MAP2K1/MEK1 in 50% and 25% of cases, respectively. We evaluated a patient with treatment-refractory LCH for mutations in the RAS-RAF-MEK-ERK pathway and identified a novel mutation in the MAP2K1 gene resulting in a p.L98_K104 > Q deletion and predicted to be auto-activating. During treatment with the MEK inhibitor trametinib, the patient's disease showed significant progression. In vitro characterization of the MAP2K1 p.L98_K104 > Q deletion confirmed its effect on cellular activation of the ERK pathway and drug resistance.
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Affiliation(s)
- David O Azorsa
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona
| | - David W Lee
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona
| | - Daniel H Wai
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona
| | - Ranjan Bista
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona.,Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona
| | - Apurvi R Patel
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona.,Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona
| | - Eiman Aleem
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona.,Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Michael M Henry
- Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona.,Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona
| | - Robert J Arceci
- Institute of Molecular Medicine, Phoenix Children's Hospital, Phoenix, Arizona.,Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona.,Center for Cancer and Blood Disorders, Phoenix Children's Hospital, Phoenix, Arizona
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17
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Thomas S, Alberts M, Henry MM, Estridge CE, Jankowski E. Routine million-particle simulations of epoxy curing with dissipative particle dynamics. J Theor Comput Chem 2018. [DOI: 10.1142/s0219633618400059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mesoscale simulation techniques have helped to bridge the length scales and time scales needed to predict the microstructures of cured epoxies, but gaps in computational cost and experimental relevance have limited their impact. In this work, we develop an open-source plugin epoxpy for HOOMD-Blue that enables epoxy crosslinking simulations of millions of particles to be routinely performed on a single modern graphics card. We demonstrate the first implementation of custom temperature-time curing profiles with dissipative particle dynamics and show that reaction kinetics depend sensitively on the stochastic bonding rates. We provide guidelines for modeling first-order reaction dynamics in a classic epoxy/hardener/toughener system and show structural sensitivity to the temperature-time profile during cure. We conclude with a discussion of how these efficient large-scale simulations can be used to evaluate ensembles of epoxy processing protocols to quantify the sensitivity of microstructure on processing.
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Affiliation(s)
- Stephen Thomas
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA
| | - Monet Alberts
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA
| | - Michael M Henry
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA
| | | | - Eric Jankowski
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725, USA
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Beharry KD, Cai CL, Henry MM, Chowdhury S, Valencia GB, Aranda JV. Co-Enzyme Q10 and n-3 Polyunsaturated Fatty Acid Supplementation Reverse Intermittent Hypoxia-Induced Growth Restriction and Improved Antioxidant Profiles in Neonatal Rats. Antioxidants (Basel) 2017; 6:E103. [PMID: 29258174 PMCID: PMC5745513 DOI: 10.3390/antiox6040103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/08/2017] [Accepted: 12/14/2017] [Indexed: 12/20/2022] Open
Abstract
Neonatal intermittent hypoxia (IH) increases the risk for many morbidities in extremely low birth weight/gestational age (ELBW/ELGA) neonates with compromised antioxidant systems and poor growth. We hypothesized that supplementation with coenzyme Q10 (CoQ10, ubiquinol) or n-3 polyunsaturated fatty acids (PUFAs) during neonatal IH improves antioxidant profiles and somatic growth in neonatal rats. Newborn rats were exposed to two IH paradigms at birth (P0): (1) 50% O₂ with brief hypoxic episodes (12% O₂); or (2) room air (RA) with brief hypoxia, until P14 during which they received daily oral CoQ10 in olive oil, n-3 PUFAs in fish oil, or olive oil only from P0 to P14. Pups were studied at P14 or placed in RA until P21 for recovery from IH (IHR). Body weight and length; organ weights; and serum antioxidants and growth factors were determined at P14 and P21. Neonatal IH resulted in sustained reductions in somatic growth, an effect that was reversed with n-3 PUFAs. Improved growth was associated with higher serum growth factors. CoQ10 decreased superoxide dismutase (SOD) and glutathione, but increased catalase, suggesting reduced oxidative stress. Further studies are needed to determine the synergistic effects of CoQ10 and n-3 PUFA co-administration for the prevention of IH-induced oxidative stress and postnatal growth deficits.
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Affiliation(s)
- Kay D Beharry
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
- Department of Ophthalmology; State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
- SUNY Eye Institute, State University of New York, New York, NY 10062, USA.
| | - Charles L Cai
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
| | - Michael M Henry
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
| | - Sara Chowdhury
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
| | - Gloria B Valencia
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
| | - Jacob V Aranda
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
- Department of Ophthalmology; State University of New York, Downstate Medical Center, Brooklyn, NY 11203, USA.
- SUNY Eye Institute, State University of New York, New York, NY 10062, USA.
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Tulapurkar ME, Maity TK, Henry MM, Shah NG, Hasday JD, Singh IS. Distinct, Gene Specific Effect of Heat Shock on Heat Shock Factor‐1 Recruitment and Expression of CXC Chemokine Genes. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.945.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Tapan K Maity
- MedicineUniversity of Maryland School of MedicineBaltimoreMD
| | - Michael M Henry
- MedicineUniversity of Maryland School of MedicineBaltimoreMD
| | - Nirav G Shah
- MedicineUniversity of Maryland School of MedicineBaltimoreMD
| | - Jeffrey D Hasday
- MedicineUniversity of Maryland School of MedicineBaltimoreMD
- Baltimore VA Medical CenterBaltimoreMD
| | - Ishwar S Singh
- MedicineUniversity of Maryland School of MedicineBaltimoreMD
- Baltimore VA Medical CenterBaltimoreMD
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Maity TK, Henry MM, Tulapurkar ME, Shah NG, Hasday JD, Singh IS. Distinct, gene-specific effect of heat shock on heat shock factor-1 recruitment and gene expression of CXC chemokine genes. Cytokine 2011; 54:61-7. [PMID: 21266308 DOI: 10.1016/j.cyto.2010.12.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 12/19/2010] [Accepted: 12/22/2010] [Indexed: 11/26/2022]
Abstract
The heat shock (HS) response, a phylogenetically conserved ubiquitous response to stress, is generally characterized by the induced expression of heat shock protein (HSP) genes. Our earlier studies showed that the stress-activated transcription factor, heat shock factor-1 (HSF1), activated at febrile range or HS temperatures also modified expression of non-HSP genes including cytokine and chemokine genes. We also showed by in silico analysis that 28 among 29 human and mouse CXC chemokine genes had multiple putative heat shock response elements (HSEs) present in their gene promoters. To further determine whether these potential HSEs were functional and bound HSF1, we analyzed the recruitment of HSF1 to promoters of 5 human CXC chemokine genes (CXCL-1, 2, 3, 5 and 8) by chromatin immunoprecipitation (ChIP) assay and analyzed the effect of HS exposure on tumor necrosis factor-α (TNFα)-induced expression of these genes in human lung epithelial-like A549 cells. HSF1 ChIP analysis showed that HSF1 was recruited to all but one of these CXC chemokine genes (CXCL-3) and HS caused a significant increase in recruitment of HSF1 to one or multiple HSEs present in the promoters of CXCL-1, 2, 5 and 8 genes. However, the effect of HS exposure on expression of these genes showed a variable gene-specific effect. For example, CXCL8 expression was markedly enhanced (p<0.05) whereas CXCL5 expression was significantly repressed (p<0.05) in cells exposed to HS coincident with TNFα stimulation. In contrast, expression of CXCL1 and CXCL2, despite HSF1 recruitment to their promoters, was not affected by HS exposure. Our results indicate that some, if not all, putative HSEs present in the CXC chemokine gene promoters are functional and recruit HSF1 in vivo but the effects on gene expression are variable and gene specific. We speculate, the physical proximity and interactions of other transcription factors and co-regulators with HSF1 could be critical to determining the effects of HS on the expression of these genes.
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Affiliation(s)
- Tapan K Maity
- Division of Pulmonary and Critical Care, Department of Medicine, University of Maryland School of Medicine, Baltimore, USA
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21
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Harris RE, Termuhlen AM, Smith LM, Lynch J, Henry MM, Perkins SL, Gross TG, Warkentin P, Vlachos A, Harrison L, Cairo MS. Autologous peripheral blood stem cell transplantation in children with refractory or relapsed lymphoma: results of Children's Oncology Group study A5962. Biol Blood Marrow Transplant 2010; 17:249-58. [PMID: 20637881 DOI: 10.1016/j.bbmt.2010.07.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 07/06/2010] [Indexed: 10/19/2022]
Abstract
This prospective study was designed to determine the safety and efficacy of cyclophosphamide, BCNU, and etoposide (CBV) conditioning and autologous peripheral blood stem cell transplant (PBSCT) in children with relapsed or refractory Hodgkin and non-Hodgkin lymphoma (HL and NHL). Patients achieving complete remission (CR) or partial remission (PR) after 2 to 4 courses of reinduction underwent a granulocyte-colony stimulating factor (G-CSF) mobilized PBSC apheresis with a target collection dose of 5 × 10⁶ CD34(+)/kg. Those eligible to proceed received autologous PBSCT after CBV (7200 mg/m², 450-300 mg/m², 2400 mg/m²). Forty-three of 69 patients (30/39 HL, 13/30 NHL) achieved a CR/PR after reinduction. Thirty-eight patients (28 HL, 10 NHL) underwent PBSCT. All initial 6 patients who received BCNU at 450 mg/m² experienced grade III or IV pulmonary toxicity compared to none of the subsequent 32 receiving 300 mg/m² (P < .0001). The probability of overall survival (OS) at 3 years for all patients is 51% and for transplanted patients is 64%. The 3-year event-free survival (EFS) is 38% (45% for HL; 30% NHL). The 3-year EFS in transplanted patients is 66% (65% HL; 70% NHL). Initial duration of remission of ≥12 versus <12 months was associated with a significant increase in OS (3 years OS 70% versus 34%) (P = .003). BCNU at 300 mg/m(2) in a CBV regimen prior to PBSCT is well tolerated in relapsed or refractory pediatric lymphoma patients. A short duration (<12 months) of initial remission is associated with a poorer prognosis. Last, a high percentage of patients achieving a CR/PR after reinduction therapy can be salvaged with CBV and autologlous PBSCT.
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Affiliation(s)
- Richard E Harris
- Division of Bone Marrow Transplant and Immune Deficiency, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
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Henry MM, Hasday JD, Singh IS. Effect of heat shock on TNF alpha‐induced chemokine expression in A549 cells. FASEB J 2007. [DOI: 10.1096/fasebj.21.5.a252-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Michael M Henry
- Department of MedicineUniversity of MarylandVAMC, Rm 3C 117, 10 N Greene StreetBaltimoreMD21201
| | - Jeffrey D Hasday
- Department of MedicineUniversity of MarylandVAMC, Rm 3C 116, 10 N Greene StreetBaltimoreMD21201
| | - Ishwar S Singh
- Department of MedicineUniversity of MarylandVAMC, Rm 3C 117, 10 N Greene StreetBaltimoreMD21201
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Mintz MB, Sowers R, Brown KM, Hilmer SC, Mazza B, Huvos AG, Meyers PA, Lafleur B, McDonough WS, Henry MM, Ramsey KE, Antonescu CR, Chen W, Healey JH, Daluski A, Berens ME, Macdonald TJ, Gorlick R, Stephan DA. An expression signature classifies chemotherapy-resistant pediatric osteosarcoma. Cancer Res 2005; 65:1748-54. [PMID: 15753370 DOI: 10.1158/0008-5472.can-04-2463] [Citation(s) in RCA: 157] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Osteosarcoma is the most common malignant bone tumor in children. Osteosarcoma patients who respond poorly to chemotherapy are at a higher risk of relapse and adverse outcome. Therefore, it was the aim of this study to identify prognostic factors at the time of diagnosis to characterize the genes predictive of poor survival outcome and to identify potential novel therapeutic targets. Expression profiling of 30 osteosarcoma diagnostic biopsy samples, 15 with inferior necrosis following induction chemotherapy (Huvos I/II) and 15 with superior necrosis following induction chemotherapy (Huvos III/IV), was conducted using Affymetrix U95Av2 oligonucleotide microarrays. One hundred and four genes were found to be statistically significant and highly differentially expressed between Huvos I/II and III/IV patients. Statistically significant genes were validated on a small independent cohort comprised of osteosarcoma xenograft tumor samples. Markers of Huvos I/II response predominantly were gene products involved in extracellular matrix (ECM) microenvironment remodeling and osteoclast differentiation. A striking finding was the significant decrease in osteoprotegerin, an osteoclastogenesis inhibitory factor. Additional genes involved in osteoclastogenesis and bone resorption, which were statistically different, include annexin 2, SMAD, PLA2G2A, and TGFbeta1. ECM remodeling genes include desmoplakin, SPARCL1, biglycan, and PECAM. Gene expression of select genes involved in tumor progression, ECM remodeling, and osteoclastogenesis were validated via quantitative reverse transcription-PCR in an independent cohort. We propose that osteosarcoma tumor-driven changes in the bone microenvironment contribute to the chemotherapy-resistant phenotype and offer testable hypotheses to potentially enhance therapeutic response.
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Affiliation(s)
- Michelle B Mintz
- Neurogenomics Division and Genetic Basis of Human Disease Division, Translational Genomics Research Institute, Phoenix, Arizona 85004, USA
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Mitchell SA, Brown KM, Henry MM, Mintz M, Catchpoole D, LaFleur B, Stephan DA. Inter-platform comparability of microarrays in acute lymphoblastic leukemia. BMC Genomics 2004; 5:71. [PMID: 15387886 PMCID: PMC522810 DOI: 10.1186/1471-2164-5-71] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Accepted: 09/23/2004] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy and has been the poster-child for improved therapeutics in cancer, with life time disease-free survival (LTDFS) rates improving from <10% in 1970 to >80% today. There are numerous known genetic prognostic variables in ALL, which include T cell ALL, the hyperdiploid karyotype and the translocations: t(12;21)[TEL-AML1], t(4;11)[MLL-AF4], t(9;22)[BCR-ABL], and t(1;19)[E2A-PBX]. ALL has been studied at the molecular level through expression profiling resulting in un-validated expression correlates of these prognostic indices. To date, the great wealth of expression data, which has been generated in disparate institutions, representing an extremely large cohort of samples has not been combined to validate any of these analyses. The majority of this data has been generated on the Affymetrix platform, potentially making data integration and validation on independent sample sets a possibility. Unfortunately, because the array platform has been evolving over the past several years the arrays themselves have different probe sets, making direct comparisons difficult. To test the comparability between different array platforms, we have accumulated all Affymetrix ALL array data that is available in the public domain, as well as two sets of cDNA array data. In addition, we have supplemented this data pool by profiling additional diagnostic pediatric ALL samples in our lab. Lists of genes that are differentially expressed in the six major subclasses of ALL have previously been reported in the literature as possible predictors of the subclass. RESULTS We validated the predictability of these gene lists on all of the independent datasets accumulated from various labs and generated on various array platforms, by blindly distinguishing the prognostic genetic variables of ALL. Cross-generation array validation was used successfully with high sensitivity and high specificity of gene predictors for prognostic variables. We have also been able to validate the gene predictors with high accuracy using an independent dataset generated on cDNA arrays. CONCLUSION Interarray comparisons such as this one will further enhance the ability to integrate data from several generations of microarray experiments and will help to break down barriers to the assimilation of existing datasets into a comprehensive data pool.
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Affiliation(s)
- Stephanie A Mitchell
- Research Center for Genetic Medicine, Children's National Medical Center, Washington, D.C. 20010, USA
- Institute of Biomedical Sciences, George Washington University Medical Center, Washington, D.C. 20037, USA
| | - Kevin M Brown
- Family Studies, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Michael M Henry
- Research Center for Genetic Medicine, Children's National Medical Center, Washington, D.C. 20010, USA
- Department of Hematology and Oncology, Children's National Medical Center, Washington, D.C. 20010, USA
| | - Michelle Mintz
- Research Center for Genetic Medicine, Children's National Medical Center, Washington, D.C. 20010, USA
- Institute of Biomedical Sciences, George Washington University Medical Center, Washington, D.C. 20037, USA
| | | | - Bonnie LaFleur
- Department of Preventative Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | - Dietrich A Stephan
- Neurogenomics Program, Translational Genomics Research Institute, Phoenix, AZ 85004, USA
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Eells JT, Henry MM, Summerfelt P, Wong-Riley MTT, Buchmann EV, Kane M, Whelan NT, Whelan HT. Therapeutic photobiomodulation for methanol-induced retinal toxicity. Proc Natl Acad Sci U S A 2003; 100:3439-44. [PMID: 12626762 PMCID: PMC152311 DOI: 10.1073/pnas.0534746100] [Citation(s) in RCA: 527] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2002] [Indexed: 11/18/2022] Open
Abstract
Methanol intoxication produces toxic injury to the retina and optic nerve, resulting in blindness. The toxic metabolite in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit the essential mitochondrial enzyme, cytochrome oxidase. Photobiomodulation by red to near-IR radiation has been demonstrated to enhance mitochondrial activity and promote cell survival in vitro by stimulation of cytochrome oxidase activity. The present studies were undertaken to test the hypothesis that exposure to monochromatic red radiation from light-emitting diode (LED) arrays would protect the retina against the toxic actions of methanol-derived formic acid in a rodent model of methanol toxicity. Using the electroretinogram as a sensitive indicator of retinal function, we demonstrated that three brief (2 min, 24 s) 670-nm LED treatments (4 J/cm(2)), delivered at 5, 25, and 50 h of methanol intoxication, attenuated the retinotoxic effects of methanol-derived formate. Our studies document a significant recovery of rod- and cone-mediated function in LED-treated, methanol-intoxicated rats. We further show that LED treatment protected the retina from the histopathologic changes induced by methanol-derived formate. These findings provide a link between the actions of monochromatic red to near-IR light on mitochondrial oxidative metabolism in vitro and retinoprotection in vivo. They also suggest that photobiomodulation may enhance recovery from retinal injury and other ocular diseases in which mitochondrial dysfunction is postulated to play a role.
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Affiliation(s)
- J T Eells
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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Patel H, Le Marer N, Wharton RQ, Khan ZAJ, Araia R, Glover C, Henry MM, Allen-Mersh TG. Clearance of circulating tumor cells after excision of primary colorectal cancer. Ann Surg 2002; 235:226-31. [PMID: 11807362 PMCID: PMC1422418 DOI: 10.1097/00000658-200202000-00010] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [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: 02/05/2023]
Abstract
OBJECTIVE To establish whether the prevalence of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results decreased during the first 3 months after colorectal cancer excision, and to assess whether persistence of RT-PCR positivity after primary colorectal cancer excision was related to tumor stage or locally advanced and metastatic disease. METHODS Systemic venous blood was collected from patients with colorectal cancer before and at intervals up to 12 weeks after surgery. RNA was extracted from the mononuclear cell fraction of the blood samples and subjected to RT-PCR using specific primers for carcinoembryonic antigen mRNA and cytokeratin-20 mRNA. Healthy individuals with no history of cancer were used as controls. RESULTS The results of RT-PCR were positive in 81 of 116 patients with colorectal cancer before surgery, with no significant differences in preoperative prevalence by Dukes stage or presence of locally advanced or metastatic disease. There was a significant decrease in the prevalence of RT-PCR positivity at 24 hours after surgery compared with before surgery. On subgroup analysis by Dukes stage, only the decrease in Dukes A and B patients reached significance. Seven of the 143 controls were RT-PCR positive. CONCLUSIONS Circulating tumor cells were present before treatment in most patients with colorectal cancer regardless of tumor stage or metastases. Clearance of circulating tumor cells within 24 hours of colorectal cancer excision was greatest in tumors with the best prognosis.
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Affiliation(s)
- Hitesh Patel
- Department of Surgery, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Chelsea and Westminster Hospital, London, United Kingdom
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Scott CS, Retsch-Bogart GZ, Henry MM. Renal failure and vestibular toxicity in an adolescent with cystic fibrosis receiving gentamicin and standard-dose ibuprofen. Pediatr Pulmonol 2001; 31:314-6. [PMID: 11288217 DOI: 10.1002/ppul.1047] [Citation(s) in RCA: 33] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Gentamicin and standard-dose ibuprofen were administered to an adolescent with cystic fibrosis who developed renal failure and severe vestibulotoxicity. A contributing factor was possible suboptimal intravascular volume status. Because of the potential severity of this drug interaction, hydration status and renal and vestibular functions should be closely monitored in patients receiving ibuprofen and intravenous aminoglycosides concomitantly.
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Affiliation(s)
- C S Scott
- Division of Pharmacotherapy, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7360, USA.
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Seme MT, Summerfelt P, Neitz J, Eells JT, Henry MM. Differential recovery of retinal function after mitochondrial inhibition by methanol intoxication. Invest Ophthalmol Vis Sci 2001; 42:834-41. [PMID: 11222547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
PURPOSE The authors' laboratory has previously documented formate-induced retinal toxicity in a rodent model of methanol intoxication. These studies determined functional, bioenergetic, and structural recovery of the retina after methanol intoxication. METHODS Rats were intoxicated with methanol, and retinal function was assessed by electroretinography 72 hours after the initial dose of methanol and after a 72-hour recovery period. Retinal energy metabolites, glutathione (GSH) concentrations, and histology were determined at the same time points. RESULTS Both rod-dominated and UV-cone-mediated electroretinogram responses were profoundly attenuated in methanol-intoxicated rats. In rats allowed to recover from methanol intoxication, there was significant, although incomplete, recovery of rod-dominated retinal function. However, there was no demonstrable improvement in UV-cone-mediated responses. Retinal adenosine triphosphate (ATP), adenosine diphosphate (ADP), and GSH concentrations were significantly reduced after intoxication. Although retinal energy metabolites returned to control values after the recovery period, retinal GSH remained significantly depleted. Histopathologic changes were apparent in the photoreceptors after methanol intoxication, with evidence of inner segment swelling and mitochondrial disruption. In animals allowed to recover from methanol intoxication, there was no evidence of histopathology at the light microscopic level; however, ultrastructural studies revealed subtle photoreceptor mitochondrial alterations. CONCLUSIONS These findings support the hypothesis that formate inhibits retinal mitochondrial function and increases oxidative stress. They also provide evidence for a differential sensitivity of photoreceptors to the cytotoxic actions of formic acid, with a partial recovery of rod-dominated responses and no recovery of UV-cone-mediated responses.
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Affiliation(s)
- M T Seme
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Eells JT, Henry MM, Gross GJ, Baker JE. Increased mitochondrial K(ATP) channel activity during chronic myocardial hypoxia: is cardioprotection mediated by improved bioenergetics? Circ Res 2000; 87:915-21. [PMID: 11073888 DOI: 10.1161/01.res.87.10.915] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased resistance to myocardial ischemia in chronically hypoxic immature rabbit hearts is associated with activation of ATP-sensitive K(+) (K(ATP)) channels. We determined whether chronic hypoxia from birth alters the function of the mitochondrial K(ATP) channel. The K(ATP) channel opener bimakalim (1 micromol/L) increased postischemic recovery of left ventricular developed pressure in isolated normoxic (FIO(2)=0.21) hearts to values (42+/-4% to 67+/-5% ) not different from those of hypoxic controls but did not alter postischemic recovery of developed pressure in isolated chronically hypoxic (FIO(2)=0.12) hearts (69+/-5% to 72+/-5%). Conversely, the K(ATP) channel blockers glibenclamide (1 micromol/L) and 5-hydroxydecanoate (5-HD, 300 micromol/L) attenuated the cardioprotective effect of hypoxia but had no effect on postischemic recovery of function in normoxic hearts. ATP synthesis rates in hypoxic heart mitochondria (3.92+/-0.23 micromol ATP. min(-1). mg mitochondrial protein(-1)) were significantly greater than rates in normoxic hearts (2.95+/-0.08 micromol ATP. min(-1). mg mitochondrial protein(-1)). Bimakalim (1 micromol/L) decreased the rate of ATP synthesis in normoxic heart mitochondria consistent with mitochondrial K(ATP) channel activation and mitochondrial depolarization. The effect of bimakalim on ATP synthesis was antagonized by the K(ATP) channel blockers glibenclamide (1 micromol/L) and 5-HD (300 micromol/L) in normoxic heart mitochondria, whereas glibenclamide and 5-HD alone had no effect. In hypoxic heart mitochondria, the rate of ATP synthesis was not affected by bimakalim but was attenuated by glibenclamide and 5-HD. We conclude that mitochondrial K(ATP) channels are activated in chronically hypoxic rabbit hearts and implicate activation of this channel in the improved mitochondrial bioenergetics and cardioprotection observed.
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Affiliation(s)
- J T Eells
- Department of Pharmacology, Division of Pediatric Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Abstract
PURPOSE Patients with chronic anal fissures are known to have high resting anal pressures that return to normal after successful surgical treatment. Internal anal sphincter activity is increased by sympathetic excitatory innervation via alpha adrenoceptors. The objective of this study was to determine the effect of alpha-1 adrenoceptor blockade on anal sphincter pressure in patients with and without chronic anal fissures. METHODS The effect on the anal canal pressure profile of a single oral 20 mg dose of indoramin, an alpha-1 adrenoceptor antagonist, on seven patients with chronic anal fissure and six healthy patients without a fissure was investigated. RESULTS Indoramin reduced anal resting pressures in those with anal fissure by a mean of 35.8 percent, from 106.9 +/- 22.15 cm H2O to 68.6 +/- 20.35 cm H2O, and in those without anal fissure by a mean of 39.9 percent, from 84.17 +/- 27.46 cm H2O to 52.17 +/- 24.78 cm H2O, after one hour. This pressure reduction persisted at three hours, and its magnitude is comparable to that obtained after internal sphincterotomy. The pressure reduction occurred over the whole length of the anal canal. CONCLUSION It is proposed that alpha-1 adrenoceptor antagonists could be a suitable treatment for chronic anal fissure and other painful conditions where reduction in anal pressure is warranted.
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Affiliation(s)
- J Pitt
- University College London Medical School, United Kingdom
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31
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Eells JT, Henry MM, Lewandowski MF, Seme MT, Murray TG. Development and characterization of a rodent model of methanol-induced retinal and optic nerve toxicity. Neurotoxicology 2000; 21:321-30. [PMID: 10894122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Methanol is an important public health and environmental concern because of the selective actions of its neurotoxic metabolite, formic acid, on the retina, optic nerve and central nervous system. Humans and non-human primates are uniquely sensitive to methanol-induced neurotoxicity as a consequence of the limited capacity of primate species to oxidize and thus detoxify formic acid. The toxic syndrome in primates is characterized by formic acidemia, metabolic acidosis and blindness or serious visual impairment. Nonprimate species are normally resistant to the accumulation of formate and associated metabolic and visual toxicity. We have characterized retinal and optic nerve toxicity in a nonprimate model of methanol toxicity using rats in which folate-dependent formate oxidation has been selectively inhibited, allowing formate to accumulate to toxic concentrations following methanol administration. Methanol-intoxicated rats developed formic acidemia, metabolic acidosis and visual toxicity analogous to the human methanol poisoning syndrome. Visual dysfunction was manifested as reductions in the electroretinogram and the flash-evoked cortical potential which occurred coincident with blood formate accumulation. Histological studies revealed mitochondrial disruption and vacuolation in the retinal pigment epithelium, photoreceptor inner segments and optic nerve. The temporal relationship between methanol administration and the onset and development of ocular toxicity, as well as, the degree of metabolic acidosis and extent of formic acidemia in this rodent model are remarkably similar to that documented in human methanol intoxication. Moreover, the functional and morphologic findings in methanol-intoxicated rats are consistent with the hypothesis that formate acts as a mitochondrial toxin in the retina and optic nerve. The establishment and characterization of this nonprimate animal model of methanol intoxication will facilitate research into the mechanistic aspects of methanol toxicity and the development and testing of treatments for human methanol poisoning.
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Affiliation(s)
- J T Eells
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226, USA.
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Fryer RM, Eells JT, Hsu AK, Henry MM, Gross GJ. Ischemic preconditioning in rats: role of mitochondrial K(ATP) channel in preservation of mitochondrial function. Am J Physiol Heart Circ Physiol 2000; 278:H305-12. [PMID: 10644614 DOI: 10.1152/ajpheart.2000.278.1.h305] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined the role of the sarcolemmal and mitochondrial K(ATP) channels in a rat model of ischemic preconditioning (IPC). Infarct size was expressed as a percentage of the area at risk (IS/AAR). IPC significantly reduced infarct size (7 +/- 1%) versus control (56 +/- 1%). The sarcolemmal K(ATP) channel-selective antagonist HMR-1098 administered before IPC did not significantly attenuate cardioprotection. However, pretreatment with the mitochondrial K(ATP) channel-selective antagonist 5-hydroxydecanoic acid (5-HD) 5 min before IPC partially abolished cardioprotection (40 +/- 1%). Diazoxide (10 mg/kg iv) also reduced IS/AAR (36.2 +/- 4.8%), but this effect was abolished by 5-HD. As an index of mitochondrial bioenergetic function, the rate of ATP synthesis in the AAR was examined. Untreated animals synthesized ATP at 2.12 +/- 0.30 micromol x min(-1) x mg mitochondrial protein(-1). Rats subjected to ischemia-reperfusion synthesized ATP at 0.67 +/- 0.06 micromol x min(-1) x mg mitochondrial protein(-1). IPC significantly increased ATP synthesis to 1.86 +/- 0.23 micromol x min(-1) x mg mitochondrial protein(-1). However, when 5-HD was administered before IPC, the preservation of ATP synthesis was attenuated (1.18 +/- 0.15 micromol x min(-1) x mg mitochondrial protein(-1)). These data are consistent with the notion that inhibition of mitochondrial K(ATP) channels attenuates IPC by reducing IPC-induced protection of mitochondrial function.
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Affiliation(s)
- R M Fryer
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Ge Y, MacDonald D, Henry MM, Hait HI, Nelson KA, Lipsky BA, Zasloff MA, Holroyd KJ. In vitro susceptibility to pexiganan of bacteria isolated from infected diabetic foot ulcers. Diagn Microbiol Infect Dis 1999; 35:45-53. [PMID: 10529881 DOI: 10.1016/s0732-8893(99)00056-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [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: 11/21/2022]
Abstract
During two clinical trials involving the treatment of 835 outpatients with infected diabetic foot ulcers, 2515 bacterial isolates, including 2337 aerobes and 178 anaerobes, were grown from cultures of the ulcers. The in vitro susceptibility of these isolates was determined to pexiganan, a peptide anti-infective evaluated in these clinical trials, and to other classes of antibiotics. Pexiganan demonstrated broad spectrum antimicrobial activity against Gram-positive and Gram-negative aerobes and anaerobes. The MIC90 values for the most common species among 1735 Gram-positive aerobes isolated, such as Staphylococcus aureus, coagulase-negative staphylococci, Group A streptococci, and Group B streptococci, were 16 micrograms/mL or less. Of 602 Gram-negative aerobes tested, the MIC90 values for pexiganan were 16 micrograms/mL or less for Acinetobacter, Pseudomonas, Stenotrophomonas, Citrobacter, Enterobacter, Escherichia, Klebsiella, and Flavobacterium species. Pexiganan had a MIC90 of 4 to 16 micrograms/mL against the anaerobic isolates of Bacteroides, Peptostreptococcus, Clostridium, and Prevotella species. Importantly, pexiganan did not exhibit cross-resistance with other commonly used antibiotics, including beta-lactams, quinolones, macrolides, and lincosamides. The broad spectrum in vitro antimicrobial activity of pexiganan against clinical isolates from infected diabetic foot ulcers supports its potential as a local therapy for infected diabetic foot ulcers.
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Affiliation(s)
- Y Ge
- Magainin Pharmaceuticals Inc., Plymouth Meeting, PA 19462, USA
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Seme MT, Summerfelt P, Henry MM, Neitz J, Eells JT. Formate-induced inhibition of photoreceptor function in methanol intoxication. J Pharmacol Exp Ther 1999; 289:361-70. [PMID: 10087025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Formic acid is the toxic metabolite responsible for the retinal and optic nerve toxicity produced in methanol intoxication. Previous studies in our laboratory have documented formate-induced retinal dysfunction and histopathology in a rodent model of methanol intoxication. The present studies define the time and concentration dependence of formate-induced retinal toxicity in methanol-intoxicated rats. Retinal function was assessed 24, 48, and 72 h after the initial dose of methanol by flicker electroretinographic measurements. Retinal histopathology was assessed at the same time intervals. Rod- and cone-mediated electroretinogram (ERG) responses were attenuated in a formate concentration- and time-dependent manner, and both retinal sensitivity and maximal responsiveness to light were diminished. Attenuation of UV-cone-mediated responses was temporally delayed in comparison to the functional deficits observed in the 15 Hz/510 nm responses, which have a rod-mediated component and occurred at significantly higher formate concentrations. Both 15 Hz/510 nm and UV-cone-mediated ERG responses were undetectable by 72 h; however, if light intensity was increased, a retinal ERG response could be recorded, indicating that photoreceptor function was profoundly attenuated, but not abolished, under these intoxication conditions. Functional changes preceded structural alterations. Histopathological changes were most pronounced in the outer retina with evidence of inner segment swelling, photoreceptor mitochondrial disruption, and the appearance of fragmented photoreceptor nuclei in the outer nuclear layer. The nature of both the functional and structural alterations observed are consistent with formate-induced inhibition of mitochondrial energy production, resulting in photoreceptor dysfunction and pathology.
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Affiliation(s)
- M T Seme
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, USA
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Hughes JM, Weill H, Checkoway H, Jones RN, Henry MM, Heyer NJ, Seixas NS, Demers PA. Radiographic evidence of silicosis risk in the diatomaceous earth industry. Am J Respir Crit Care Med 1998; 158:807-14. [PMID: 9731009 DOI: 10.1164/ajrccm.158.3.9709103] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
There is limited and conflicting evidence regarding the exposure-response relationship between exposure to crystalline silica and silicosis; the level of risk to current workers remains uncertain. We conducted an epidemiologic investigation of 1,809 workers in the diatomaceous earth industry, where exposures to crystalline silica are primarily to the cristobalite form. On the basis of the median of three independent readings, 81 (4.5%) workers were judged to have opacities on chest radiographs (small opacities, profusion >= 1/0, and/or large opacities). Age-adjusted relative risk of opacities increased significantly with cumulative exposure to crystalline silica. The concentration of respirable crystalline silica to which workers were exposed (highly correlated with period of hire) was an important determinant of risk after accounting for cumulative exposure. For workers with an average exposure to crystalline silica of <= 0.50 mg/m3 (or hired >= 1950), the cumulative risk of opacities for a cumulative exposure to crystalline silica of 2.0 mg/m3-yr was approximately 1.1%; for an average exposure > 0.50 mg/m3 (or hired < 1950), the corresponding cumulative risk was 3.7%. These findings indicate an exposure-response relationship between cumulative exposure to crystalline silica and radiographic opacities; moreover, the relationship was substantially steeper among workers exposed at the highest average concentrations of crystalline silica.
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Affiliation(s)
- J M Hughes
- Department of Biostatistics and Epidemiology, and Department of Medicine, Tulane University, New Orleans, Louisiana, USA.
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Farel AM, Hooper SR, Teplin SW, Henry MM, Kraybill EN. Very-low-birthweight infants at seven years: an assessment of the health and neurodevelopmental risk conveyed by chronic lung disease. J Learn Disabil 1998; 31:118-126. [PMID: 9529782 DOI: 10.1177/002221949803100202] [Citation(s) in RCA: 17] [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] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To determine whether history of chronic lung disease (CLD) in children born at very low birthweight (VLBW) confers additional risk for impaired health, growth, and neurodevelopment, 17 VLBW children born in 1984 who had CLD (requiring supplemental oxygen more than 30 days after birth) in infancy and 28 VLBW children who did not have CLD were assessed at age 7 years. Assessments included a medical history, standard physical and neurological examinations, pulmonary-function tests, and tests of neuropsychological and psychoeducational functioning. Health status did not differ between the groups. In contrast, children with CLD did not perform as well in neuropsychological and psychoeducational assessments. Although CLD confers little added risk to health, it seems to add significantly to risks for poor school performance that are known to be associated with very low birthweight.
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Affiliation(s)
- A M Farel
- Department of Maternal and Child Health, School of Public Health-CB #7400, University of North Carolina, Chapel Hill 27599, USA
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Jones KM, Liao E, Hohneker K, Turpin S, Henry MM, Selinger K, Hsyu PH, Boucher RC, Knowles MR, Dukes GE. Pharmacokinetics of amiloride after inhalation and oral administration in adolescents and adults with cystic fibrosis. Pharmacotherapy 1997; 17:263-70. [PMID: 9085317] [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: 02/04/2023]
Abstract
STUDY OBJECTIVE To compare the pharmacokinetics and systemic exposure of nebulized and oral amiloride in adolescents and adults with mild to moderate cystic fibrosis (CF). DESIGN Open-label, randomized, two-way crossover, single-dose pharmacokinetic study. SETTING University hospital clinical research unit. PATIENTS Nine adolescents and 10 adults with mild to moderate CF (forced expiratory volume in 1 sec > or = 50% predicted, Brasfield score > or = 15). INTERVENTIONS Patients received amiloride solution orally (10 mg of amiloride 1-mg/ml solution) and by inhalation [4.5 ml amiloride of 1-mg/ml solution in 12% saline (approximately 3.8 mmol/L) by DeVilbiss 646 nebulizer] during two study phases separated by a 7- to 28-day washout period. Serial blood and urine samples were collected for 48 and 72 hours, respectively. MEASUREMENTS AND MAIN RESULTS After oral dosing, the mean +/- SD maximum peak concentration (Cmax) was 20.6 +/- 10.0 ng/ml at 3.2 +/- 1.2 hours in adults and 21.7 +/- 4.88 at 2.9 +/- 0.6 hours in the adolescents. Mean area under the concentration-time curve (AUC) from time zero to infinity hours was 275 +/- 115 and 254 +/- 60 ng.hr/ml in the adult and adolescent groups; half-life was 16.0 +/- 0.7 and 13.4 +/- 1.4 hours, respectively. After nebulization, 14 of 19 subjects exhibited two concentration peaks (Cmax1 and Cmax2) with mean values of 1.57 +/- 1.67 ng/ml at 0.5 +/- 0.2 hours and 1.37 +/- 1.21 ng/ml at 4.0 +/- 1.0 hours for adults, and 1.49 +/- 0.99 ng/ml at 0.5 +/- 0.1 hours and 1.52 +/- 0.81 ng/ml at 3.3 +/- 0.5 hours for adolescents. Estimated mean +/- SD dose nebulized was 1.91 +/- 0.66 and 2.28 +/- 0.30 mg in the adult and adolescent groups, respectively. Mean +/- SD AUC from time zero to the last measurable plasma amiloride concentration after inhalation was 14.4 +/- 17.6 and 15.4 +/- 10.1 ng.hr/ml in the adults and adolescents. No significant adverse events occurred during the study. Pharmacokinetic parameters were not statistically different between the adolescent and adult groups by route of administration. However significant differences in peak amiloride concentration, AUC, and urinary amiloride excretion were evident when comparing oral versus inhalation administration within each group. CONCLUSIONS Mean amiloride plasma concentration peaks and AUC after inhalation were significantly lower than after oral dosing. In addition, the second amiloride plasma concentration peak may be due to oral ingestion of the nebulized amiloride, whereas the earlier Cmax1 after inhalation may be due to pulmonary absorption of amiloride. These results suggest that single-dose amiloride inhalation in patients with mild to moderate CF results in minimal systemic exposure compared with oral dosing, and that drug disposition is similar in adolescents and adults with CF.
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Affiliation(s)
- K M Jones
- Department of Pharmacy Practice, School of Pharmacy, Campbell University, Buies Creek, NC 27506, USA
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Affiliation(s)
- C J Fowler
- National Hospital for Neurology and Neurosurgery, London, England
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Chia YW, Gill KP, Jameson JS, Forti AD, Henry MM, Swash M, Shorvon PJ. Paradoxical puborectalis contraction is a feature of constipation in patients with multiple sclerosis. J Neurol Neurosurg Psychiatry 1996; 60:31-5. [PMID: 8558147 PMCID: PMC486186 DOI: 10.1136/jnnp.60.1.31] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [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: 01/31/2023]
Abstract
OBJECTIVE To study the disturbed anorectal physiology associated with constipation in multiple sclerosis. METHODS Anorectal function in 10 patients with clinically definite multiple sclerosis and constipation has been compared with 10 normal persons and 11 patients with idiopathic constipation, without multiple sclerosis. RESULTS All 10 constipated patients with multiple sclerosis had difficulty evacuating barium paste during defaecography. In four of these there was complete failure of puborectalis relaxation when straining to defaecate, and in another four there was incomplete puborectalis relaxation. There was no evidence of lower motor neuron involvement of pelvic floor muscles in the multiple sclerosis group. CONCLUSIONS Paradoxical puborectalis contraction is common in patients with multiple sclerosis in whom constipation is a symptom. This may be a feature of the disturbed voluntary sphincter control mechanism, analogous to detrusor sphincter dyssnergia in the bladder.
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Affiliation(s)
- Y W Chia
- Department of Surgery, Central Middlesex Hospital, London, UK
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Affiliation(s)
- J S Penn
- Arkansas Center for Eye Research, University of Arkansas for Medical Sciences, Little Rock 72205, USA
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Abstract
Inflammation can be demonstrated in the airway mucosa of asthmatics, even in the absence of overt symptoms, but the pathogenesis of this chronic inflammation is incompletely defined. It has been suggested that inflammatory cytokines produced by epithelium may play important roles in this process. Therefore, we measured the cytokines interleukin-8 (IL-8), IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in nasal lavage fluids from school-age children who were (1) "normal" (nonallergic/nonasthmatic), (2) allergic to house-dust mite antigen but nonasthmatic (no history of wheezing), or (3) allergic and asthmatic (history of > or = 10 wheezing episodes). Children underwent a single nasal lavage procedure while asymptomatic and on no anti-inflammatory medications or anti-histamines. In addition to cytokine concentrations, cell counts, differentials, albumin, histamine, and eosinophil cationic protein (ECP) concentrations were determined in nasal lavage fluids. Significant increases in IL-8 and ECP were observed in asthmatics compared with both normals and allergic nonasthmatics. Overall, IL-8 in nasal lavage fluids correlated significantly with ECP. Allergic nonasthmatics did not have significant increases in cytokines or other mediators compared with normal subjects. Concentrations of IL-6 did not differ significantly among the three groups, and GM-CSF was undetectable in all samples tested. We conclude that increased IL-8 production and eosinophil activation are characteristic of the airways of asthmatic children when asymptomatic, and we speculate that IL-8 plays a role in the maintenance of airway inflammation in asthma.
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Affiliation(s)
- T L Noah
- Department of Pediatrics, University of North Carolina at Chapel Hill, USA
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Penn JS, Henry MM, Wall PT, Tolman BL. The range of PaO2 variation determines the severity of oxygen-induced retinopathy in newborn rats. Invest Ophthalmol Vis Sci 1995; 36:2063-70. [PMID: 7657545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
PURPOSE This study was conducted to determine the potential influence of PaO2 fluctuation on the retinal neovascular response known to occur in newborn rats exposed to hyperoxic conditions. As an inherent corollary, the authors also defined the relationship between the fraction of inspired oxygen (FiO2) and the arterial blood oxygen tension (PaO2) in newborn rats. METHODS Experiment 1 was composed of several oxygen-exposure protocols in which atmospheres of 10% oxygen concentration were alternated with different higher levels of ambient oxygen (50%, 40%, 30%, and room air). In experiment 2, two alternating oxygen concentrations were made to converge toward room air (20.9% oxygen) with each successive group of four treatment groups. These included another group exposed to alternating 50% and 10% oxygen, a group exposed to alternating 45% and 12.5% oxygen concentrations, one exposed to alternating concentrations of 40% and 15% oxygen, and a final group exposed to 35% and room air oxygen concentrations. In each case, oxygen was alternated between the two exposure concentrations every 24 hours. The term delta FiO2 is used to designate the difference in the two oxygen concentrations to which a treatment group was subjected, applying the units of fraction of inspired oxygen (i.e., delta FiO2 = 0.4 for the exposure to alternating 50% and 10% oxygen). At birth, litters of albino rats were placed in each of these environments for 13 or 14 days, after which PaO2 and retinal vascular development were assessed in some rats. The remainder were removed to room air for 4 days before the incidence and severity of abnormal neovascularization were measured. RESULTS PaO2 and FiO2 were directly and linearly correlated (r2 = 0.998). In experiment 1, the extent of retinal vascular development on removal from oxygen was a linear function of delta FiO2. Retinal neovascularization subsequently occurred in all rats exposed to alternating 50% and 10% or 40% and 10% oxygen concentrations, but only a third of the 30% and 10% exposure group, indicating a minimum threshold for proliferative disease at delta FiO2 = 0.2. In experiment 2, retinal avascularity also increased linearly with increasing delta FiO2. There was a threshold for neovascularization between the exposure to alternating 45% and 12.5% oxygen and the 40% and 15% oxygen exposure (100% versus 4.8% incidence of neovascularization), indicating a requirement of < or = 12.5% oxygen episodes to stimulate a consistent proliferative response. CONCLUSIONS These results suggest that PaO2 fluctuation and degree of hypoxia may have more influence on proliferative retinal disease in newborn rats than the extended hyperoxia that has historically received greater attention. Experimental designs that address the inherent differences in pulmonary function between intrinsically healthy animals and compromised premature infants are of substantial value to our understanding of the pathogenesis of retinopathy of prematurity.
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Affiliation(s)
- J S Penn
- Arkansas Center for Eye Research, University of Arkansas for Medical Sciences, Little Rock 72205-7199, USA
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Henderson FW, Henry MM, Ivins SS, Morris R, Neebe EC, Leu SY, Stewart PW. Correlates of recurrent wheezing in school-age children. The Physicians of Raleigh Pediatric Associates. Am J Respir Crit Care Med 1995; 151:1786-93. [PMID: 7767521 DOI: 10.1164/ajrccm.151.6.7767521] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Correlates of recurrent wheezing were examined in a case-control study involving 343 children ranging from 7 to 12 yr of age and recruited from a general pediatric practice. Positive skin tests for allergy were observed in 35% of a random sample of children without recurrent wheezing, and in 77% and 90% of children who had experienced from two to four episodes and five or more episodes, respectively, of recent wheezing. By logistic regression analysis, sensitization to dust mite (odds ratio [OR]: 5.2; 95% CI: 3.0 to 9.0), cat (OR: 15.5; 95% CI: 3.4 to 70.8), and Alternaria (OR: 6.8; 95% CI: 2.1 to 21.5) antigens was consistently associated with recurrent wheezing. Sensitization to pollen antigen(s), observed in 60% of allergic children, was not associated with wheezing. A family history of asthma was a significant predictor of recurrent wheezing (OR: 3.2; 95% CI: 1.7 to 5.9) after adjusting for its association with positive skin tests. Environmental tobacco smoke (ETS) exposure was associated with an increased risk of recurrent wheezing in nonallergic children and in allergic females, but not in allergic males. ETS exposure was not associated with positive skin tests for allergy. A history of wheezing with respiratory illness before 2 yr of age was associated with a modest risk of recurrent wheezing between 7 and 12 yr of age (OR: 2.3; 95% CI: 1.2 to 4.6), a risk that did not differ by allergic status or gender. Theoretically, the prevalence of recurrent wheezing in this population could be reduced approximately 65% by controlling exposure to indoor allergens and ETS.
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Affiliation(s)
- F W Henderson
- Department of Pediatrics, University of North Carolina at Chapel Hill 27599-7220, USA
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Speakman CT, Hoyle CH, Kamm MA, Swash M, Henry MM, Nicholls RJ, Burnstock G. Abnormal internal anal sphincter fibrosis and elasticity in fecal incontinence. Dis Colon Rectum 1995; 38:407-10. [PMID: 7720450 DOI: 10.1007/bf02054231] [Citation(s) in RCA: 31] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE We aimed to investigate the changes in the proportion of collagen and in the elasticity of the internal anal sphincter in patients with neurogenic fecal incontinence. METHODS Collagen content was studied in ten patients with neurogenic fecal incontinence (mean age, 51.5 years) and ten controls (age, 58.6 years) using histologic techniques to determine differences between incontinence and health and to determine the effect of aging. Changes in elasticity were also measured in 8 controls (mean age, 63 years) and 13 patients with neurogenic incontinence (mean age, 60 years) by recording the in vitro length-tension relationship of the freshly excised internal anal sphincter. RESULTS Incontinent patients had a significantly higher collagen content than controls (55 percent vs. 33 percent; P = 0.013). In incontinent patients the amount of collagen and the patients' ages correlated significantly (P = 0.001). There was a greater increase in stable tension per increase in muscle length in the strips from incontinent patients compared with controls. CONCLUSIONS Changes in fibrous tissue content are likely to influence muscle tone and responsiveness of the sphincter in fecal incontinence.
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Affiliation(s)
- C T Speakman
- Sir Alan Parks Physiology Unit, St Mark's Hospital, London, United Kingdom
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Abstract
The widespread success of laparoscopic cholecystectomy has led to the development of a wide range of laparoscopic surgical procedures. Procedures for treating rectal prolapse (Procidentia) may constitute some of the best applications for colorectal laparoscopic techniques. A technique of laparoscopic rectopexy performed using the endo-stapler is described. Twenty-nine consecutive patients have undergone laparoscopic rectopexy. The median age was 71 years (52-89), and male:female ratio was 27:2. One procedure had to be converted to open due to ventilatory difficulties. The mean operative time was 95 minutes (50-190). The mean hospital stay was 5 days (4-15). There was no mortality in this series. Morbidity included incisional hernia through a port hole (n = 1), extraperitoneal haematoma (n = 1), and urinary tract infection with retention (n = 1). In conclusion, laparoscopic abdominal rectopexy is a safe and effective technique in the management of rectal prolapse.
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Affiliation(s)
- A Darzi
- Academic Surgical Unit, St. Mary's Hospital, London, UK
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Chia YW, Fowler CJ, Kamm MA, Henry MM, Lemieux MC, Swash M. Prevalence of bowel dysfunction in patients with multiple sclerosis and bladder dysfunction. J Neurol 1995; 242:105-8. [PMID: 7707085 DOI: 10.1007/bf00887825] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [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: 01/26/2023]
Abstract
Urinary dysfunction is common in cases of multiple sclerosis (MS). The close proximity of those neural pathways which control the bladder to those which control anorectal function might be expected to lead to a high coexistence of bladder and bowel symptoms. Seventy-seven consecutive patients with clinically definite MS attending a uroneurology clinic were interviewed about their bowel function. All patients had clinical evidence of spinal cord disease with varying degrees of impaired mobility and sufficiently severe disturbance of bladder control to seek medical advice. Thirty-six per cent of these patients had constipation. Twenty per cent had "current incontinence", although another 30% had had at least one episode of faecal incontinence more than 3 months previously. Some patients had both constipation and faecal incontinence. A total of 52% currently had at least one bowel symptom. The pattern of bowel symptoms did not correlate with the pattern of urinary disturbance, or the duration of MS, or the degree of disability. Bowel symptoms are common in patients with MS, but even in those with urinary dysfunction are not universal. Whereas bladder dysfunction in MS is clearly related to spinal cord disease, the neurological basis for the bowel dysfunction is less clear.
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Affiliation(s)
- Y W Chia
- Department of Uro-neurology, National Hospital for Neurology and Neurosurgery, London, UK
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Chia YW, Darzi A, Speakman CT, Hill AD, Jameson JS, Henry MM. CO2 laser haemorrhoidectomy--does it alter anorectal function or decrease pain compared to conventional haemorrhoidectomy? Int J Colorectal Dis 1995; 10:22-4. [PMID: 7745318 DOI: 10.1007/bf00337581] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Carbon dioxide (CO2) laser haemorrhoidectomy is feasible and safe provided it is used with care. It is associated with a reduced requirement for post-operative analgesia. The CO2 laser caused no significant alteration in anorectal physiology.
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Affiliation(s)
- Y W Chia
- Department of Surgery, Central Middlesex Hospital, London, UK
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Abstract
Exposure to variable hyperoxia has recently been shown to be much more effective at producing proliferative retinopathy in the newborn rat than exposure to constant hyperoxia. To incorporate a more clinically relevant oxygen-exposure paradigm in our studies, we have now used a cycle between 50 and 10% oxygen and have compared its effects with those found using new exposures to the previously used 80/40% cycle. Starting at birth and continuing for 14 d, rats were exposed to environments that cycled between 50 and 10% oxygen or 80 and 40% oxygen every 24 h. After exposure, some rats were killed for assessment of retinal vascular development. Others were removed to room air for 4 d before killing and evaluation for the presence of abnormal neovascularization--a clinical consequence believed to be promoted by termination of oxygen therapy. The 50/10% cycle resulted in greater retardation of retinal blood vessel development during oxygen than that found in the 80/40% exposure group. After 4 d postexposure in room air, the incidence of preretinal neovascularization was 97% in the 50/10% rats and 72% in the 80/40% group. Clearly, the overall amount of oxygen the subject receives is less critical than other parameters of its administration in producing proliferative retinopathy. Also, the range of variation (40% in both cases) is not the controlling characteristic. Our results suggest that consistency of oxygen level and avoidance of hypoxic levels should be important concerns in neonatal oxygen therapy.
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Affiliation(s)
- J S Penn
- Arkansas Center for Eye Research, University of Arkansas for Medical Sciences, Little Rock 72205-7199
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49
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Abstract
Ninety-one healthy subjects (51 women; age range 16-85 years) were studied prospectively to determine the effect of age, sex and parity on anorectal function. Maximum resting pressure, voluntary contraction pressure, rectal sensation to distension, rectal and mid-anal electrosensitivity, perineal descent, pudendal nerve terminal motor latency and fibre density of the external and sphincter were measured. Sex influenced mean(s.d.) voluntary contraction pressure (148(56) versus 95(43) cmH2O for men versus women, P < 0.0001), perineal descent on straining (1.0(0.5) versus 1.3(0.4) cm, P = 0.02) and fibre density (1.43(0.14) versus 1.52(0.15), P = 0.02). Age influenced resting pressure (r = -0.43, P = 0.0001), perineal position at rest (r = -0.55, P < or = 0.0001), mid-anal electrosensitivity (r = 0.42, P = 0.0001) and rectal electrosensitivity (r = 0.54, P < 0.0001). Parity affected mean(s.d.) voluntary contraction pressure (105(53) versus 75(20) cmH2O for nulliparous versus parous women, P = 0.04) and mid-anal electrosensitivity (5.3(2.3) versus 4.5(2.3) mA, P = 0.02). Increasing age leads to perineal descent at rest, slowed pudendal nerve conduction, a fall in resting anal pressure and decreased anorectal sensory function. Women have a lower and squeeze pressure, greater perineal descent, longer pudendal nerve terminal motor latency and a greater muscle fibre density than men. Parity leads only to lower squeeze pressure.
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Affiliation(s)
- J S Jameson
- Department of Gastroenterology, Central Middlesex Hospital, London, UK
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Penn JS, Tolman BL, Henry MM. Oxygen-induced retinopathy in the rat: relationship of retinal nonperfusion to subsequent neovascularization. Invest Ophthalmol Vis Sci 1994; 35:3429-35. [PMID: 8056518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
PURPOSE To confirm a relationship between oxygen-induced retinal vasoattenuation and subsequent abnormal neovascularization in the newborn rat. METHODS Beginning at birth, some litters of Sprague-Dawley rats were exposed to 80% constant oxygen while others received oxygen varying between 40% and 80% in a cyclic fashion. The frequency of the change in inspired oxygen (FiO2) was either 6, 12, 24, or 48 hours. The exposures periods lasted for 14 days, at which time some rats from each exposure group were sacrificed and assessed for retinal vasoattenuation with injection of fluorescein-labeled dextran. The remaining rats from each group were transferred at day 14 from the hyperoxic atmosphere to room air for an additional 4 days. These animals were then killed and assessed for retinal neovascularization by staining for vascular ADPase activity. RESULTS Of all rats raised in variable oxygen, 62% exhibited abnormal retinal neovascularization after 4 days in room air. Only 18% of the rats exposed to constant oxygen responded with abnormal neovascularization. Among the four groups of variable oxygen-exposed rats, there was a direct correlation (R2 = 0.96) between degree of retinal avascularity upon removal from oxygen and the propensity for subsequent abnormal neovascularization. Constant oxygen-exposed rats did not exhibit this relationship. This exposure produced the greatest retinal avascularity upon removal from oxygen but the lowest incidence of abnormal neovascularization after 4 days in room air. CONCLUSIONS Retinal avascularity may not be the single overriding stimulus for neovascularization in oxygen-induced retinopathy. Other hypotheses bear consideration, including the possibility that variable oxygen leads directly to vascular endothelial cell mitosis, a common retinal manifestation of ischemia-reperfusion.
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Affiliation(s)
- J S Penn
- Arkansas Center for Eye Research, University of Arkansas for Medical Science, Little Rock 72205-7199
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