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Jiang W, Armstrong GSJ, Han L, Xu Y, Zuo Z, Tong J, Lu P, Dahlström JM, Ueda K, Brown AC, van der Hart HW, Gong X, Wu J. Resolving Quantum Interference Black Box through Attosecond Photoionization Spectroscopy. Phys Rev Lett 2023; 131:203201. [PMID: 38039486 DOI: 10.1103/physrevlett.131.203201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/30/2023] [Accepted: 10/13/2023] [Indexed: 12/03/2023]
Abstract
Multiphoton light-matter interactions invoke a so-called "black box" in which the experimental observations contain the quantum interference between multiple pathways. Here, we employ polarization-controlled attosecond photoelectron metrology with a partial wave manipulator to deduce the pathway interference within this quantum 'black box" for the two-photon ionization of neon atoms. The angle-dependent and attosecond time-resolved photoelectron spectra are measured across a broad energy range. Two-photon phase shifts for each partial wave are reconstructed through the comprehensive analysis of these photoelectron spectra. We resolve the quantum interference between the degenerate p→d→p and p→s→p two-photon ionization pathways, in agreement with our theoretical simulations. Our approach thus provides an attosecond time-resolved microscope to look inside the "black box" of pathway interference in ultrafast dynamics of atoms, molecules, and condensed matter.
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Affiliation(s)
- Wenyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Gregory S J Armstrong
- Centre for Light-Matter Interaction, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Lulu Han
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yidan Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zitan Zuo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Jihong Tong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | | | - Kiyoshi Ueda
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Department of Chemistry, Tohoku University, Sendai 980-8578, Japan
| | - Andrew C Brown
- Centre for Light-Matter Interaction, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Hugo W van der Hart
- Centre for Light-Matter Interaction, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401121, China
- CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
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Amarasinghe HE, Zhang P, Whalley JP, Allcock A, Migliorini G, Brown AC, Scozzafava G, Knight JC. Mapping the epigenomic landscape of human monocytes following innate immune activation reveals context-specific mechanisms driving endotoxin tolerance. BMC Genomics 2023; 24:595. [PMID: 37805492 PMCID: PMC10559536 DOI: 10.1186/s12864-023-09663-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 09/08/2023] [Indexed: 10/09/2023] Open
Abstract
BACKGROUND Monocytes are key mediators of innate immunity to infection, undergoing profound and dynamic changes in epigenetic state and immune function which are broadly protective but may be dysregulated in disease. Here, we aimed to advance understanding of epigenetic regulation following innate immune activation, acutely and in endotoxin tolerant states. METHODS We exposed human primary monocytes from healthy donors (n = 6) to interferon-γ or differing combinations of endotoxin (lipopolysaccharide), including acute response (2 h) and two models of endotoxin tolerance: repeated stimulations (6 + 6 h) and prolonged exposure to endotoxin (24 h). Another subset of monocytes was left untreated (naïve). We identified context-specific regulatory elements based on epigenetic signatures for chromatin accessibility (ATAC-seq) and regulatory non-coding RNAs from total RNA sequencing. RESULTS We present an atlas of differential gene expression for endotoxin and interferon response, identifying widespread context specific changes. Across assayed states, only 24-29% of genes showing differential exon usage are also differential at the gene level. Overall, 19.9% (6,884 of 34,616) of repeatedly observed ATAC peaks were differential in at least one condition, the majority upregulated on stimulation and located in distal regions (64.1% vs 45.9% of non-differential peaks) within which sequences were less conserved than non-differential peaks. We identified enhancer-derived RNA signatures specific to different monocyte states that correlated with chromatin accessibility changes. The endotoxin tolerance models showed distinct chromatin accessibility and transcriptomic signatures, with integrated analysis identifying genes and pathways involved in the inflammatory response, detoxification, metabolism and wound healing. We leveraged eQTL mapping for the same monocyte activation states to link potential enhancers with specific genes, identifying 1,946 unique differential ATAC peaks with 1,340 expression associated genes. We further use this to inform understanding of reported GWAS, for example involving FCHO1 and coronary artery disease. CONCLUSION This study reports context-specific regulatory elements based on transcriptomic profiling and epigenetic signatures for enhancer-derived RNAs and chromatin accessibility in immune tolerant monocyte states, and demonstrates the informativeness of linking such elements and eQTL to inform future mechanistic studies aimed at defining therapeutic targets of immunosuppression and diseases.
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Affiliation(s)
- Harindra E Amarasinghe
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK.
| | - Ping Zhang
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
- Chinese Academy of Medical Science Oxford Institute, University of Oxford, Oxford, OX3 7BN, UK
| | - Justin P Whalley
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Alice Allcock
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Gabriele Migliorini
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Andrew C Brown
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Giuseppe Scozzafava
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK
| | - Julian C Knight
- Wellcome Centre for Human Genetics, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK.
- Chinese Academy of Medical Science Oxford Institute, University of Oxford, Oxford, OX3 7BN, UK.
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Brown AC, Cohen CJ, Mielczarek O, Migliorini G, Costantino F, Allcock A, Davidson C, Elliott KS, Fang H, Lledó Lara A, Martin AC, Osgood JA, Sanniti A, Scozzafava G, Vecellio M, Zhang P, Black MH, Li S, Truong D, Molineros J, Howe T, Wordsworth BP, Bowness P, Knight JC. Comprehensive epigenomic profiling reveals the extent of disease-specific chromatin states and informs target discovery in ankylosing spondylitis. Cell Genom 2023; 3:100306. [PMID: 37388915 PMCID: PMC10300554 DOI: 10.1016/j.xgen.2023.100306] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 01/30/2023] [Accepted: 03/27/2023] [Indexed: 07/01/2023]
Abstract
Ankylosing spondylitis (AS) is a common, highly heritable inflammatory arthritis characterized by enthesitis of the spine and sacroiliac joints. Genome-wide association studies (GWASs) have revealed more than 100 genetic associations whose functional effects remain largely unresolved. Here, we present a comprehensive transcriptomic and epigenomic map of disease-relevant blood immune cell subsets from AS patients and healthy controls. We find that, while CD14+ monocytes and CD4+ and CD8+ T cells show disease-specific differences at the RNA level, epigenomic differences are only apparent upon multi-omics integration. The latter reveals enrichment at disease-associated loci in monocytes. We link putative functional SNPs to genes using high-resolution Capture-C at 10 loci, including PTGER4 and ETS1, and show how disease-specific functional genomic data can be integrated with GWASs to enhance therapeutic target discovery. This study combines epigenetic and transcriptional analysis with GWASs to identify disease-relevant cell types and gene regulation of likely pathogenic relevance and prioritize drug targets.
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Affiliation(s)
- Andrew C. Brown
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Carla J. Cohen
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- MRC WIMM Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7LD, UK
| | - Olga Mielczarek
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Horizon Discovery (PerkinElmer) Cambridge Research Park, 8100 Beach Dr., Waterbeach, Cambridge CB25 9TL, UK
| | - Gabriele Migliorini
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Félicie Costantino
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- UVSQ, INSERM UMR1173, Infection et Inflammation, Laboratory of Excellence INFLAMEX, Université Paris-Saclay, Paris, France
- Rheumatology Department, AP-HP, Ambroise Paré Hospital, Paris, France
| | - Alice Allcock
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Connor Davidson
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7LD, UK
| | | | - Hai Fang
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Centre for Translational Medicine at Shanghai, Ruijin Hospital affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Alicia Lledó Lara
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Alice C. Martin
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Julie A. Osgood
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Anna Sanniti
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Giuseppe Scozzafava
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Matteo Vecellio
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7LD, UK
- Centro Ricerche Fondazione Italiana Ricerca sull’Artrite (FIRA), Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini 13, 56017 San Giuliano Terme (Pisa), Italy
| | - Ping Zhang
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Chinese Academy of Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK
| | - Mary Helen Black
- Data Science, Population Analytics, Janssen R&D, Spring House, PA 19002, USA
| | - Shuwei Li
- Data Science, Population Analytics, Janssen R&D, Spring House, PA 19002, USA
| | - Dongnhu Truong
- Data Science, Population Analytics, Janssen R&D, Spring House, PA 19002, USA
| | - Julio Molineros
- Data Science, Population Analytics, Janssen R&D, Spring House, PA 19002, USA
| | - Trevor Howe
- Data Science, External Innovation, Janssen R&D, London W1G 0BG, UK
| | - B. Paul Wordsworth
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7LD, UK
- National Institute for Health Research, Comprehensive Biomedical Research Centre, Oxford OX4 2PG, UK
| | - Paul Bowness
- Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7LD, UK
- National Institute for Health Research, Comprehensive Biomedical Research Centre, Oxford OX4 2PG, UK
| | - Julian C. Knight
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
- Chinese Academy of Medical Sciences Oxford Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK
- National Institute for Health Research, Comprehensive Biomedical Research Centre, Oxford OX4 2PG, UK
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Jiang W, Armstrong GSJ, Tong J, Xu Y, Zuo Z, Qiang J, Lu P, Clarke DDA, Benda J, Fleischer A, Ni H, Ueda K, van der Hart HW, Brown AC, Gong X, Wu J. Atomic partial wave meter by attosecond coincidence metrology. Nat Commun 2022; 13:5072. [PMID: 36038537 PMCID: PMC9424306 DOI: 10.1038/s41467-022-32753-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 08/15/2022] [Indexed: 11/29/2022] Open
Abstract
Attosecond chronoscopy is central to the understanding of ultrafast electron dynamics in matter from gas to the condensed phase with attosecond temporal resolution. It has, however, not yet been possible to determine the timing of individual partial waves, and steering their contribution has been a substantial challenge. Here, we develop a polarization-skewed attosecond chronoscopy serving as a partial wave meter to reveal the role of each partial wave from the angle-resolved photoionization phase shifts in rare gas atoms. We steer the relative ratio between different partial waves and realize a magnetic-sublevel-resolved atomic phase shift measurement. Our experimental observations are well supported by time-dependent R-matrix numerical simulations and analytical soft-photon approximation analysis. The symmetry-resolved, partial-wave analysis identifies the transition rate and phase shift property in the attosecond photoelectron emission dynamics. Our findings provide critical insights into the ubiquitous attosecond optical timer and the underlying attosecond photoionization dynamics. Understanding the photoelectron emission time after the interaction of photon with atoms and molecules is of fundamental interest. Here the authors examine the role of partial waves to the photoionization phase shift of atoms using an attosecond clock and electron-ion coincidence spectroscopy.
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Affiliation(s)
- Wenyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Gregory S J Armstrong
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast, BT7 1NN, Northern Ireland, UK
| | - Jihong Tong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Yidan Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Zitan Zuo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Junjie Qiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Daniel D A Clarke
- School of Physics and CRANN Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Jakub Benda
- Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00, Prague 8, Czech Republic
| | - Avner Fleischer
- Raymond and Beverly Sackler Faculty of Exact Science, School of Chemistry and Center for Light-Matter Interaction, Tel Aviv University, 6997801, Tel-Aviv, Israel
| | - Hongcheng Ni
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, China
| | - Kiyoshi Ueda
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China
| | - Hugo W van der Hart
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast, BT7 1NN, Northern Ireland, UK
| | - Andrew C Brown
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast, BT7 1NN, Northern Ireland, UK.
| | - Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China. .,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, China.
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China. .,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, China. .,CAS Center for Excellence in Ultra-intense Laser Science, Shanghai, China.
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Moody CT, Brown AE, Massaro NP, Patel AS, Agarwalla PA, Simpson AM, Brown AC, Zheng H, Pierce JG, Brudno Y. Restoring Carboxylates on Highly Modified Alginates Improves Gelation, Tissue Retention and Systemic Capture. Acta Biomater 2022; 138:208-217. [PMID: 34728426 PMCID: PMC8738153 DOI: 10.1016/j.actbio.2021.10.046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/05/2021] [Accepted: 10/26/2021] [Indexed: 01/17/2023]
Abstract
Alginate hydrogels are gaining traction for use in drug delivery, regenerative medicine, and as tissue engineered scaffolds due to their physiological gelation conditions, high tissue biocompatibility, and wide chemical versatility. Traditionally, alginate is decorated at the carboxyl group to carry drug payloads, peptides, or proteins. While low degrees of substitution do not cause noticeable mechanical changes, high degrees of substitution can cause significant losses to alginate properties including complete loss of calcium cross-linking. While most modifications used to decorate alginate deplete the carboxyl groups, we propose that alginate modifications that replenish the carboxyl groups could overcome the loss in gel integrity and mechanics. In this report, we demonstrate that restoring carboxyl groups during functionalization maintains calcium cross-links as well as hydrogel shear-thinning and self-healing properties. In addition, we demonstrate that alginate hydrogels modified to a high degree with azide modifications that restore the carboxyl groups have improved tissue retention at intramuscular injection sites and capture blood-circulating cyclooctynes better than alginate hydrogels modified with azide modifications that deplete the carboxyl groups. Taken together, alginate modifications that restore carboxyl groups could significantly improve alginate hydrogel mechanics for clinical applications. STATEMENT OF SIGNIFICANCE: Chemical modification of hydrogels provides a powerful tool to regulate cellular adhesion, immune response, and biocompatibility with local tissues. Alginate, due to its biocompatibility and easy chemical modification, is being explored for tissue engineering and drug delivery. Unfortunately, modifying alginate to a high degree of substitution consumes carboxyl group, which are necessary for ionic gelation, leading to poor hydrogel crosslinking. We introduce alginate modifications that restore the alginate's carboxyl groups. We demonstrate that modifications that reintroduce carboxyl groups restore gelation and improve gel mechanics and tissue retention. In addition to contributing to a basic science understanding of hydrogel properties, we anticipate our approach will be useful to create tissue engineered scaffolds and drug delivery platforms.
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Affiliation(s)
- C T Moody
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America
| | - A E Brown
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America
| | - N P Massaro
- Department of Chemistry, North Carolina State University, Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America
| | - A S Patel
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC United States of America
| | - P A Agarwalla
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America
| | - A M Simpson
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America
| | - A C Brown
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America
| | - H Zheng
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC United States of America
| | - J G Pierce
- Department of Chemistry, North Carolina State University, Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America
| | - Y Brudno
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University at Raleigh, NC United States of America; Department of Chemistry, North Carolina State University, Raleigh, NC United States of America; Comparative Medicine Institute, North Carolina State University, Raleigh, NC United States of America; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC United States.
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Maxwell AS, Armstrong GSJ, Ciappina MF, Pisanty E, Kang Y, Brown AC, Lewenstein M, Figueira de Morisson Faria C. Manipulating twisted electrons in strong-field ionization. Faraday Discuss 2021; 228:394-412. [PMID: 33591304 DOI: 10.1039/d0fd00105h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We investigate the discrete orbital angular momentum (OAM) of photoelectrons freed in strong-field ionization. We use these 'twisted' electrons to provide an alternative interpretation on existing experimental work of vortex interferences caused by strong field ionization mediated by two counter-rotating circularly polarized pulses separated by a delay. Using the strong field approximation, we derive an interference condition for the vortices. In computations for a neon target we find very good agreement of the vortex condition with photoelectron momentum distributions computed with the strong field approximation, as well as with the time-dependent methods Qprop and R-Matrix. For each of these approaches we examine the OAM of the photoelectrons, finding a small number of vortex states localized in separate energy regions. We demonstrate that the vortices arise from the interference of pairs of twisted electron states. The OAM of each twisted electron state can be directly related to the number of arms of the spiral in that region. We gain further understanding by recreating the vortices with pairs of twisted electrons and use this to determine a semiclassical relation for the OAM. A discussion is included on measuring the OAM in strong field ionization directly or by employing specific laser pulse schemes as well as utilizing the OAM in time-resolved imaging of photo-induced dynamics.
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Affiliation(s)
- A S Maxwell
- Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK. and ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - G S J Armstrong
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, Northern Ireland, UK
| | - M F Ciappina
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain and Physics Program, Guangdong Technion - Israel Institute of Technology, Shantou, Guangdong 515063, China and Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - E Pisanty
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Y Kang
- Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK.
| | - A C Brown
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, Northern Ireland, UK
| | - M Lewenstein
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain and ICREA, Pg. Lluís Companys 23, 08010, Spain
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Chester D, Theetharappan P, Ngobili T, Daniele M, Brown AC. Ultrasonic Microplotting of Microgel Bioinks. ACS Appl Mater Interfaces 2020; 12:47309-47319. [PMID: 33026794 DOI: 10.1021/acsami.0c15056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Material scaffolds that mimic the structure, function, and bioactivity of native biological tissues are in constant development. Recently, material scaffolds composed of microgel particles have shown promise for applications ranging from bone regeneration to spheroid cell growth. Previous studies with poly N-isopropylacrylamide microgel scaffolds utilized a layer-by-layer (LBL) technique where individual, uniform microgel layers are built on top of each other resulting in a multilayer scaffold. However, this technique is limited in its applications due to the inability to control microscale deposition or patterning of multiple particle types within a microgel layer. In this study, an ultrasonic microplotting technique is used to address the limitations of LBL fabrication to create patterned microgel films. Printing parameters, such as bioink formulation, surface contact angle, and print head diameter, are optimized to identify the ideal parameters needed to successfully print microgel films. It was found that bioinks composed of 2 mg/mL of microgels and 20% polyethylene glycol by volume (v/v), on bovine serum albumin-coated glass, with a print head diameter of 50 μm resulted in the highest quality prints. Patterned films were created with a maximum resolution of 50 μm with the potential for finer resolutions to be achieved with alternative bioink compositions and printing parameters. Overall, ultrasonic microplotting can be used to create more complex microgel films than is possible with LBL techniques and offers the possibility of greater printing resolution in 3D with further technology development.
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Affiliation(s)
- D Chester
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - P Theetharappan
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - T Ngobili
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - M Daniele
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - A C Brown
- Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
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De Silva M, Brown AC, Patrick AL. Thermal- and collision-induced dissociation studies of functionalized imidazolium-based ionic liquid cations. J Mass Spectrom 2020; 55:e4518. [PMID: 32578308 DOI: 10.1002/jms.4518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/12/2020] [Indexed: 06/11/2023]
Abstract
Ionic liquids are now used in applications ranging from chemical synthesis to spacecraft propulsion. With this comes the need to characterize new syntheses, identify environmental contamination, and determine eventual fate in terrestrial and space environments. This work investigates the effects of source conditions, particularly capillary temperature, on the observed mass spectrum and determines the collision-induced dissociation (CID) patterns of imidazolium-based ionic liquid cations as a function of their substituent types. Experiments were carried out on a Thermo LTQ-XL ion-trap mass spectrometer and a Bruker microTOF-Q II mass spectrometer. Dissociation of the imidazolium cations occurred predominantly via substituent losses, except in benzyl-substituted systems, for which the neutral loss of the imidazole was exclusively observed. Several of these dissociation pathways were studied in greater depth using complementary quantum chemical calculations. The nature of the neutral losses from the substituents was found to be highly dependent upon the nature of the substituent, as would be expected, establishing bases for characterization.
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Affiliation(s)
- Maleesha De Silva
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| | - Andrew C Brown
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
| | - Amanda L Patrick
- Department of Chemistry, Mississippi State University, Mississippi State, Mississippi, USA
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9
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Wragg J, Clarke DDA, Armstrong GSJ, Brown AC, Ballance CP, van der Hart HW. Resolving Ultrafast Spin-Orbit Dynamics in Heavy Many-Electron Atoms. Phys Rev Lett 2019; 123:163001. [PMID: 31702341 DOI: 10.1103/physrevlett.123.163001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/09/2019] [Indexed: 06/10/2023]
Abstract
We use R-matrix with time-dependence theory, with spin-orbit effects included, to study krypton irradiated by two time-delayed extreme ultraviolet ultrashort pulses. The first pulse excites the atom to 4s^{2}4p^{5}5s. The second pulse then excites 4s4p^{6}5s autoionizing levels, whose population can be observed through their subsequent decay. By varying the time delay between the two pulses, we are able to control the excitation pathway to the autoionizing states. The use of cross-polarized light pulses allows us to isolate the two-photon pathway, with one photon taken from each pulse.
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Affiliation(s)
- Jack Wragg
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Daniel D A Clarke
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Gregory S J Armstrong
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Andrew C Brown
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Connor P Ballance
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
| | - Hugo W van der Hart
- Centre for Theoretical Atomic Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, United Kingdom
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10
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Nellenbach K, Guzzetta NA, Brown AC. Analysis of the structural and mechanical effects of procoagulant agents on neonatal fibrin networks following cardiopulmonary bypass. J Thromb Haemost 2018; 16:2159-2167. [PMID: 30182421 DOI: 10.1111/jth.14280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Indexed: 12/18/2022]
Abstract
Essentials The standard of care (SOC) for treating neonatal bleeding is transfusion of adult blood products. We compared neonatal clots formed with cryoprecipitate (SOC) to two procoagulant therapies. The current SOC resulted in clots with increased stiffness and decreased fibrinolytic properties. Procoagulant therapies may be a viable alternative to SOC treatment for neonatal bleeding. SUMMARY: Background Bleeding is a serious complication of neonates undergoing cardiopulmonary bypass (CPB) and associated with substantial morbidity and mortality. Bleeding is addressed through the transfusion of adult blood products, including platelets and cryoprecipitate. However, significant differences exist between neonatal and adult clotting components, specifically fibrinogen. Our recent ex vivo studies have shown that neonatal fibrinogen does not fully integrate with adult fibrinogen, leading to decreased susceptibility to fibrinolysis. These differences may contribute to ineffective clot formation and/or an increased risk of thrombosis. A need exists to identify more effective and safer methods to promote clotting in neonates. Objectives Procoagulant agents, such as prothrombin complex concentrates (PCCs) and recombinant activated factor VII (rFVIIa), are being used off-label to treat excessive bleeding in neonates after CPB. Because these agents stimulate endogenous fibrin formation, we hypothesize that their addition to post-CPB neonatal plasma will better recapitulate native clot properties than cryoprecipitate. Methods We analyze the structural, mechanical and degradation properties of fibrin matrices formed by neonatal plasma collected after CPB in the presence of an activated four-factor (F) PCC (FEIBA), rFVIIa, or cryoprecipitate using confocal microscopy, atomic force microscopy and a fluidics-based degradation assay. Results The ex vivo addition of FEIBA and rFVIIa to post-CPB neonatal plasma resulted in enhanced clot networks with differences in fibrin alignment, mechanics and degradation properties. Conclusions Our results suggest that these procoagulant agents could be used as an alternative to the transfusion of adult fibrinogen for the treatment of bleeding after CPB in neonates.
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Affiliation(s)
- K Nellenbach
- Joint Department of Biomedical Engineering, North Carolina State University and The University of North Carolina at Chapel Hill, Raleigh, NC, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA
| | - N A Guzzetta
- Department of Anesthesiology, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - A C Brown
- Joint Department of Biomedical Engineering, North Carolina State University and The University of North Carolina at Chapel Hill, Raleigh, NC, USA
- Comparative Medicine Institute, North Carolina State University, Raleigh, NC, USA
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11
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Brown AC, Reddy VRAP, Lee J, Nair V. Marek's disease virus oncoprotein Meq physically interacts with the chicken infectious anemia virus-encoded apoptotic protein apoptin. Oncotarget 2018; 9:28910-28920. [PMID: 29988968 PMCID: PMC6034753 DOI: 10.18632/oncotarget.25628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/31/2018] [Indexed: 12/17/2022] Open
Abstract
Marek's disease (MD) is a neoplastic disease of poultry caused by Marek's disease virus (MDV), a highly contagious alphaherpesvirus. Meq, the major MDV oncoprotein, induces neoplastic transformation of T-cells through several mechanisms, including inhibition of apoptosis. In contrast, the chicken anemia virus (CAV)-encoded protein apoptin (VP3) is a powerful inducer of apoptosis of tumor cells, a property that is exploited for anticancer therapeutics. Although the molecular mechanisms of selective induction of tumor cell apoptosis by apoptin are not fully understood, its tumor cell–restricted nuclear translocation is thought to be important. Co-infection with MDV and CAV is common in many countries, CAV antigens are readily detectable in MD lymphomas, and the MDV-transformed T-lymphoblastoid cell lines such as MSB-1 is widely used for propagating CAV for vaccine production. As MDV-transformed cell lines express high levels of Meq, we examined here whether CAV-encoded apoptin interacts with Meq in these cells. Using immunofluorescence microscopy, we found that apoptin and Meq co-localize to the nucleus, and biochemical analysis indicated that the two proteins do physically interact. Using a combination of Meq mutagenesis and co-immunoprecipitation, we demonstrate that apoptin interacts with Meq within a region between amino acids 130 and 140. Results from the IncuCyte assay suggested that Meq inhibits apoptin-induced apoptosis activity. In summary, our findings indicate that Meq interacts with and inhibits apoptin. Insights into this novel interaction between Meq and apoptin will relevance for pathogenesis of coinfections of the two viruses and in CAV vaccine production using MDV-transformed cell lines.
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Affiliation(s)
- Andrew C Brown
- Wellcome Trust Centre for Human Genetics, Oxford, OX3 7BN, UK
| | | | - Joshua Lee
- Bristol University, Bristol, BS8 1TH, UK
| | - Venugopal Nair
- Viral Oncogenesis Group, The Pirbright Institute, Pirbright, Surrey, GU24 0NF, UK
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12
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Brown AC, van der Hart HW. Extreme-Ultraviolet-Initated High-Order Harmonic Generation: Driving Inner-Valence Electrons Using Below-Threshold-Energy Extreme-Ultraviolet Light. Phys Rev Lett 2016; 117:093201. [PMID: 27610852 DOI: 10.1103/physrevlett.117.093201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 06/06/2023]
Abstract
We propose a novel scheme for resolving the contribution of inner- and outer-valence electrons in extreme-ultraviolet (XUV)-initiated high-harmonic generation in neon. By probing the atom with a low-energy (below the 2s ionization threshold) ultrashort XUV pulse, the 2p electron is steered away from the core, while the 2s electron is enabled to describe recollision trajectories. By selectively suppressing the 2p recollision trajectories, we can resolve the contribution of the 2s electron to the high-harmonic spectrum. We apply the classical trajectory model to account for the contribution of the 2s electron, which allows for an intuitive understanding of the process.
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Affiliation(s)
- A C Brown
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - H W van der Hart
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
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13
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Brown AC, Powell JG, Kegley EB, Gadberry MS, Reynolds JL, Hughes HD, Carroll JA, Burdick Sanchez NC, Thaxton YV, Backes EA, Richeson JT. Effect of castration timing and oral meloxicam administration on growth performance, inflammation, behavior, and carcass quality of beef calves. J Anim Sci 2016; 93:2460-70. [PMID: 26020341 DOI: 10.2527/jas.2014-8695] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Beef bull calves (n = 62) were assigned randomly, within sire breed, to 1 of 4 treatments at birth. Treatments were 1) surgical castration near birth, 2) surgical castration near birth with oral administration of meloxicam (1 mg/kg BW), 3) surgical castration at weaning (WNG), or 4) surgical castration at weaning with oral administration of meloxicam (1 mg/kg BW; WMX). A subset of calves (n = 7/treatment group) were selected randomly near birth for blood collection, behavioral analyses, and rectal temperature (RT) records for a 7-d postcastration period on d 0 (birth), 1, 3, and 7, and on d 214 (weaning), 214 + 6 h, 215, 217, 221, and 228. Calf standing and lying activity were monitored from the same subsets by recording x- and y-axis positions of an accelerometer attached to the right metatarsus for 7 d postcastration. Calf BW was recorded throughout the entire production cycle, and carcass data were collected at slaughter. For statistical analyses, bulls left intact at birth were considered a positive control (BUL) for observations that occurred before their treatment application at weaning; likewise, bulls castrated at birth were considered a negative control (STR) during postweaning observations. No difference (P > 0.88) occurred in ADG between treatments throughout the preweaning period (d 0 to 214); however, 56-d postweaning ADG was greatest ( P= 0.02) in STR, intermediate in WMX, and least in WNG. At weaning, haptoglobin (Hp) was greater (P ≤ 0.005) for WNG and WMX compared to STR on d 214+6 h, 215, and 217, and Hp was greater (P = 0.05) in WNG compared to WMX on d 217. Neutrophils increased (P < 0.001) and red blood cells decreased (P ≤ 0.03) for WNG and WMX on d 214+6 h and 217, respectively. Postweaning behavior observations indicated that STR calves spent the least proportion of time standing (P = 0.002) when compared to WNG and WMX. Furthermore, WMX calves exhibited a greater proportion of time spent standing (P = 0.03) compared to WNG. Grazing and finishing phase ADG and carcass measurements did not differ (P ≥ 0.24) across treatments. In this study, surgical castration at weaning, but not near birth, altered the acute phase response, behavior, and growth performance. Oral meloxicam reduced serum Hp and improved ADG briefly when administered to calves castrated at weaning. Oral administration of meloxicam may be efficacious for mitigating some of the stress and inflammation associated with castration of weaning-age bull calves.
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14
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Gold MJ, Hiebert PR, Park HY, Stefanowicz D, Le A, Starkey MR, Deane A, Brown AC, Liu G, Horvat JC, Ibrahim ZA, Sukkar MB, Hansbro PM, Carlsten C, VanEeden S, Sin DD, McNagny KM, Knight DA, Hirota JA. Mucosal production of uric acid by airway epithelial cells contributes to particulate matter-induced allergic sensitization. Mucosal Immunol 2016; 9:809-20. [PMID: 26509876 DOI: 10.1038/mi.2015.104] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 09/03/2015] [Indexed: 02/07/2023]
Abstract
Exposure to particulate matter (PM), a major component of air pollution, contributes to increased morbidity and mortality worldwide. PM induces innate immune responses and contributes to allergic sensitization, although the mechanisms governing this process remain unclear. Lung mucosal uric acid has also been linked to allergic sensitization. The links among PM exposure, uric acid, and allergic sensitization remain unexplored. We therefore investigated the mechanisms behind PM-induced allergic sensitization in the context of lung mucosal uric acid. PM10 and house dust mite exposure selectively induced lung mucosal uric acid production and secretion in vivo, which did not occur with other challenges (lipopolysaccharide, virus, bacteria, or inflammatory/fibrotic stimuli). PM10-induced uric acid mediates allergic sensitization and augments antigen-specific T-cell proliferation, which is inhibited by uricase. We then demonstrate that human airway epithelial cells secrete uric acid basally and after stimulation through a previously unidentified mucosal secretion system. Our work discovers a previously unknown mechanism of air pollution-induced, uric acid-mediated, allergic sensitization that may be important in the pathogenesis of asthma.
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Affiliation(s)
- M J Gold
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - P R Hiebert
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - H Y Park
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - D Stefanowicz
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Le
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - M R Starkey
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - A Deane
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - A C Brown
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - G Liu
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - J C Horvat
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - Z A Ibrahim
- Discipline of Pharmacy, Graduate School of Health, The University of Technology Sydney, Sydney, Australia.,Woolcock Institute of Medical Research, Sydney Medical School, The University of Sydney, Sydney, Australia
| | - M B Sukkar
- Discipline of Pharmacy, Graduate School of Health, The University of Technology Sydney, Sydney, Australia.,Woolcock Institute of Medical Research, Sydney Medical School, The University of Sydney, Sydney, Australia
| | - P M Hansbro
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - C Carlsten
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver General Hospital, Vancouver, British Columbia, Canada
| | - S VanEeden
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - D D Sin
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - K M McNagny
- Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - D A Knight
- Priority Research Centre for Asthma and Respiratory Disease, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, Australia.,Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - J A Hirota
- James Hogg Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Vancouver Coastal Health Research Institute, Vancouver General Hospital, Vancouver, British Columbia, Canada
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15
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Brown AC, Koufos E, Balashova NV, Boesze-Battaglia K, Lally ET. Inhibition of LtxA toxicity by blocking cholesterol binding with peptides. Mol Oral Microbiol 2015; 31:94-105. [PMID: 26352738 DOI: 10.1111/omi.12133] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2015] [Indexed: 12/30/2022]
Abstract
The leukotoxin (LtxA) produced by Aggregatibacter actinomycetemcomitans kills host immune cells, allowing the bacterium to establish an ecological niche in the upper aerodigestive tract of its human host. The interaction of LtxA with human immune cells is both complex and multifaceted, involving membrane lipids as well as cell-surface proteins. In the initial encounter with the host cell, LtxA associates with lymphocyte function-associated antigen-1, a cell surface adhesion glycoprotein. However, we have also demonstrated that the toxin associates strongly with the plasma membrane lipids, specifically cholesterol. This association with cholesterol is regulated by a cholesterol recognition amino acid consensus (CRAC) motif, with a sequence of (334) LEEYSKR(340), in the N-terminal region of the toxin. Here, we have demonstrated that removal of cholesterol from the plasma membrane or mutation of the LtxA CRAC motif inhibits the activity of the toxin in THP-1 cells. To inhibit LtxA activity, we designed a short peptide corresponding to the CRAC(336) motif of LtxA (CRAC(336WT)). This peptide binds to cholesterol and thereby inhibits the toxicity of LtxA in THP-1 cells. Previously, we showed that this peptide inhibits LtxA toxicity against Jn.9 (Jurkat) cells, indicating that peptides derived from the cholesterol-binding site of LtxA may have a potential clinical applicability in controlling infections of repeats-in-toxin-producing organisms.
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Affiliation(s)
- A C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - E Koufos
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - N V Balashova
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - K Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - E T Lally
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
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16
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Walters MJ, Brown AC, Edrington TC, Baranwal S, Du Y, Lally ET, Boesze-Battaglia K. Membrane association and destabilization by Aggregatibacter actinomycetemcomitans leukotoxin requires changes in secondary structures. Mol Oral Microbiol 2013; 28:342-53. [PMID: 23678967 DOI: 10.1111/omi.12028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2013] [Indexed: 01/13/2023]
Abstract
Aggregatibacter actinomycetemcomitans is a common inhabitant of the upper aerodigestive tract of humans and non-human primates and is associated with disseminated infections, including lung and brain abscesses, pediatric infective endocarditis, and localized aggressive periodontitis. Aggregatibacter actinomycetemcomitans secretes a repeats-in-toxin protein, leukotoxin, which exclusively kills lymphocyte function-associated antigen-1-bearing cells. The toxin's pathological mechanism is not fully understood; however, experimental evidence indicates that it involves the association with and subsequent destabilization of the target cell's plasma membrane. We have long hypothesized that leukotoxin secondary structure is strongly correlated with membrane association and destabilization. In this study, we tested this hypothesis by analysing lipid-induced changes in leukotoxin conformation. Upon incubation of leukotoxin with lipids that favor leukotoxin-membrane association, we observed an increase in leukotoxin α-helical content that was not observed with lipids that favor membrane destabilization. The change in leukotoxin conformation after incubation with these lipids suggests that membrane binding and membrane destabilization have distinct secondary structural requirements, suggesting that they are independent events. These studies provide insight into the mechanism of cell damage that leads to disease progression by A. actinomycetemcomitans.
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Affiliation(s)
- M J Walters
- Department of Pathology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104, USA
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17
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Clotfelter ED, Lapidus SJH, Brown AC. The effects of temperature and dissolved oxygen on antioxidant defences and oxidative damage in the fathead minnow Pimephales promelas. J Fish Biol 2013; 82:1086-1092. [PMID: 23464565 DOI: 10.1111/jfb.12050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 12/15/2012] [Indexed: 06/01/2023]
Abstract
Fathead minnows Pimephales promelas maintained at 25° C for 6 h had significantly higher superoxide dismutase (SOD) activity than fish maintained at 7 or 32° C, but hypoxic conditions (3 mg l(-1) O2 ) over the same time period did not affect SOD activity. Fish in better body condition (length-adjusted mass) had higher SOD activity. In a separate experiment, P. promelas maintained at three water temperatures (7, 23 and 32° C) for 31 days did not differ in liver acrolein, a biomarker of oxidative stress.
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Affiliation(s)
- E D Clotfelter
- Department of Biology, Amherst College, Amherst, MA 01002, USA.
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18
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Brown AC, Hutchinson S, Lysaght MA, van der Hart HW. Interference between competing pathways in atomic harmonic generation. Phys Rev Lett 2012; 108:063006. [PMID: 22401067 DOI: 10.1103/physrevlett.108.063006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Indexed: 05/31/2023]
Abstract
We investigate the influence of the autoionizing 3s3p(6)nℓ resonances on the fifth harmonic generated by 200-240 nm laser fields interacting with Ar. To determine the influence of a multielectron response we develop the capability within time-dependent R-matrix theory to determine the harmonic spectra generated. The fifth harmonic is affected by interference between the response of a 3s electron and the response of a 3p electron, as demonstrated by the asymmetric profiles in the harmonic yields as functions of wavelength.
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Affiliation(s)
- A C Brown
- Centre for Theoretical Atomic, Molecular and Optical Physics, Queen's University Belfast, Belfast, United Kingdom
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19
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Fong KP, Tang HY, Brown AC, Kieba IR, Speicher DW, Boesze-Battaglia K, Lally ET. Aggregatibacter actinomycetemcomitans leukotoxin is post-translationally modified by addition of either saturated or hydroxylated fatty acyl chains. Mol Oral Microbiol 2011; 26:262-76. [PMID: 21729247 DOI: 10.1111/j.2041-1014.2011.00617.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aggregatibacter actinomycetemcomitans, a common inhabitant of the human upper aerodigestive tract, produces a repeat in toxin (RTX), leukotoxin (LtxA). The LtxA is transcribed as a 114-kDa inactive protoxin with activation being achieved by attachment of short chain fatty acyl groups to internal lysine residues. Methyl esters of LtxA that were isolated from A. actinomycetemcomitans strains JP2 and HK1651 and subjected to gas chromatography/mass spectrometry contained palmitoyl (C16:0, 27-29%) and palmitolyl (C16:1 cis Δ9, 43-44%) fatty acyl groups with smaller quantities of myristic (C14:0, 14%) and stearic (C18:0, 12-14%) fatty acids. Liquid chromatography/mass spectrometry of tryptic peptides from acylated and unacylated recombinant LtxA confirmed that Lys(562) and Lys(687) are the sites of acyl group attachment. During analysis of recombinant LtxA peptides, we observed peptide spectra that were not observed as part of the RTX acylation schemes of either Escherichia coliα-hemolysin or Bordetella pertussis cyclolysin. Mass calculations of these spectra suggested that LtxA was also modified by the addition of monohydroxylated forms of C14 and C16 acyl groups. Multiple reaction monitoring mass spectrometry identified hydroxymyristic and hydroxypalmitic acids in wild-type LtxA methyl esters. Single or tandem replacement of Lys(562) and Lys(687) with Arg blocks acylation, resulting in a >75% decrease in cytotoxicity when compared with wild-type toxin, suggesting that these post-translational modifications are playing a critical role in LtxA-mediated target cell cytotoxicity.
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Affiliation(s)
- K P Fong
- School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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20
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Ostrov DA, Barnes CL, Smith LE, Binns S, Brusko TM, Brown AC, Quint PS, Litherland SA, Roopenian DC, Iczkowski KA. Characterization of HKE2: an ancient antigen encoded in the major histocompatibility complex. ACTA ACUST UNITED AC 2007; 69:181-8. [PMID: 17257322 DOI: 10.1111/j.1399-0039.2006.00730.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [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: 11/29/2022]
Abstract
Genes at the centromeric end of the human leukocyte antigen region influence adaptive autoimmune diseases and cancer. In this study, we characterized protein expression of HKE2, a gene located in the centromeric portion of the class II region of the major histocompatibility complex encoding subunit 6 of prefoldin. Immunohistochemical analysis using an anti-HKE2 antibody indicated that HKE2 protein expression is dramatically upregulated as a consequence of activation. In a tissue microarray and in several tumors, HKE2 was overexpressed in certain cancers compared with normal counterparts. The localization of the HKE2 gene to the class II region, its cytoplasmic expression and putative protein-binding domain suggest that HKE2 may function in adaptive immunity and cancer.
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Affiliation(s)
- D A Ostrov
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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21
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Brown AC, Lerner CP, Graber JH, Shaffer DJ, Roopenian DC. Pooling and PCR as a method to combat low frequency gene targeting in mouse embryonic stem cells. Cytotechnology 2006; 51:81-8. [PMID: 19002898 DOI: 10.1007/s10616-006-9021-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 08/22/2006] [Accepted: 08/23/2006] [Indexed: 10/24/2022] Open
Abstract
The introduction of germ line modifications by gene targeting in mouse embryonic stem (ES) cells has proven a fundamental technology to relate genes to mammalian biology. Critical aspects required for successful gene targeting have traditionally been experimental enhancements that increase the frequency or detection of homologous recombination within ES cells; however, the utilization of such methods may still result in the failed isolation of a positively targeted ES cell clone. In this study, we discuss the current enhancement methods and describe an ES cell pooling strategy that maximizes the ability to detect properly targeted ES cells regardless of an inherent low targeting efficiency. The sensitivity required to detect correctly targeted events out of a pool of ES cell clones is provided by polymerase chain reaction (PCR), and only those pools containing positives need to be expanded and screened to find individually targeted clones. This method made it possible to identify targeted clones from a screen of approximately 2,300 ES cell colonies by performing only 123 PCR reactions. This technically streamlined approach bypasses the need to troubleshoot and re-engineer an existing targeting construct that is functionally suitable despite its low targeting frequency.
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Affiliation(s)
- A C Brown
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA,
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Brown AC, Baigent SJ, Smith LP, Chattoo JP, Petherbridge LJ, Hawes P, Allday MJ, Nair V. Interaction of MEQ protein and C-terminal-binding protein is critical for induction of lymphomas by Marek's disease virus. Proc Natl Acad Sci U S A 2006; 103:1687-92. [PMID: 16446447 PMCID: PMC1413633 DOI: 10.1073/pnas.0507595103] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [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] [Indexed: 11/18/2022] Open
Abstract
Marek's disease virus (MDV) is an oncogenic herpesvirus that induces fatal T cell lymphomas in chickens. With more than 20 billion doses of vaccine used annually, vaccination constitutes the cornerstone of Marek's disease control. Despite the success of vaccination, evolution of virulence among MDV strains continues to threaten the effectiveness of the current Marek's disease vaccines. MDV-encoded protein MEQ (MDV EcoRI Q) probably acts as a transcription factor and is considered to be the major MDV oncoprotein. MEQ sequence shows a Pro-Leu-Asp-Leu-Ser (PLDLS) motif known to bind C-terminal-binding protein (CtBP), a highly conserved cellular transcriptional corepressor with roles in the regulation of development, proliferation, and apoptosis. Here we show that MEQ can physically and functionally interact with CtBP through this motif and that this interaction is critical for oncogenesis because mutations in the CtBP-interaction domain completely abolished oncogenicity. This direct role for MEQ-CtBP interaction in MDV oncogenicity highlights the convergent evolution of molecular mechanisms of neoplastic transformation by herpesviruses because Epstein-Barr virus oncoproteins EBNA 3A and 3C also interact with CtBP. We also demonstrate that the nononcogenic MDV generated by mutagenesis of the CtBP-interaction domain of MEQ has the potential to be an improved vaccine against virulent MDV infection. Engineering MDV with precisely defined attenuating mutations, therefore, represents an effective strategy for generating new vaccines against this major poultry disease.
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Affiliation(s)
- Andrew C. Brown
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, United Kingdom
| | - Susan J. Baigent
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Lorraine P. Smith
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Jason P. Chattoo
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Lawrence J. Petherbridge
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Pippa Hawes
- Bioimaging Group, Institute for Animal Health, Ash Road, Pirbright, Guildford GU24 0NF, United Kingdom; and
| | - Martin J. Allday
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London W2 1PG, United Kingdom
- To whom correspondence may be addressed. E-mail:
or
| | - Venugopal Nair
- *Viral Oncogenesis Group, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, United Kingdom
- To whom correspondence may be addressed. E-mail:
or
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Petherbridge L, Brown AC, Baigent SJ, Howes K, Sacco MA, Osterrieder N, Nair VK. Oncogenicity of virulent Marek's disease virus cloned as bacterial artificial chromosomes. J Virol 2004; 78:13376-80. [PMID: 15542691 PMCID: PMC525015 DOI: 10.1128/jvi.78.23.13376-13380.2004] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Marek's disease virus (MDV) is an oncogenic alphaherpesvirus that induces T-cell lymphomas in poultry. We report the construction of bacterial artificial chromosome (BAC) clones of the highly oncogenic RB-1B strain by inserting mini-F vector sequences into the U(S)2 locus. MDV reconstituted from two BAC clones induced rapid-onset lymphomas similar to those induced by the wild-type virus. Virus reconstituted from another BAC clone that showed a 7.7-kbp deletion in the internal and terminal unique long repeat regions was nononcogenic, suggesting that the deleted region may be associated with oncogenicity. The generation of the oncogenic BAC clones of MDV is a significant step in unraveling the oncogenic determinants of this virus.
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Affiliation(s)
- Lawrence Petherbridge
- Viral Oncogenesis Group, Institute for Animal Health, High St., Compton, Berkshire RG20 7NN, United Kingdom
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Hart GT, Shaffer DJ, Akilesh S, Brown AC, Moran L, Roopenian DC, Baker PJ. Quantitative gene expression profiling implicates genes for susceptibility and resistance to alveolar bone loss. Infect Immun 2004; 72:4471-9. [PMID: 15271905 PMCID: PMC470695 DOI: 10.1128/iai.72.8.4471-4479.2004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [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: 11/22/2003] [Revised: 03/06/2004] [Accepted: 04/12/2004] [Indexed: 01/22/2023] Open
Abstract
Periodontal disease is one of the most prevalent chronic inflammatory diseases. There is a genetic component to susceptibility and resistance to this disease. Using a mouse model, we investigated the progression of alveolar bone loss by gene expression profiling of susceptible and resistant mouse strains (BALB/cByJ and A/J, respectively). We employed a novel and sensitive quantitative real-time PCR method to compare basal RNA transcription of a 48-gene set in the gingiva and the spleen and the subsequent changes in gene expression due to Porphyromonas gingivalis oral infection. Basal expression of interleukin-1 beta (Il1b) and tumor necrosis factor alpha (Tnf) mRNA was higher in the gingiva of the susceptible BALB/cByJ mice than in the gingiva of resistant A/J mice. Gingival Il1b gene expression increased further and Stat6 gene expression was turned on after P. gingivalis infection in BALB/cByJ mice but not in A/J mice. The basal expression of interleukin-15 (Il15) in the gingiva and the basal expression of p-selectin (Selp) in the spleen were higher in the resistant A/J mice than in the susceptible BALB/cByJ mice. In the resistant A/J mice the expression of no genes detectably changed in the gingiva after infection. These results suggest a molecular phenotype in which discrete sets of differentially expressed genes are associated with genetically determined susceptibility (Il1b, Tnf, and Stat6) or resistance (Il15 and Selp) to alveolar bone loss, providing insight into the genetic etiology of this complex disease.
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Affiliation(s)
- G T Hart
- Bates College, Lewiston, ME 04240, USA
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Jules-Elysee K, Urban MK, Urquhart BL, Susman MH, Brown AC, Kelsey WT. Pulmonary complications in anterior-posterior thoracic lumbar fusions. Spine J 2004; 4:312-6. [PMID: 15125855 DOI: 10.1016/j.spinee.2003.11.008] [Citation(s) in RCA: 36] [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] [Received: 04/07/2003] [Accepted: 11/19/2003] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Surgery for adult spinal deformity may require both an anterior and posterior approach in order to stabilize the spine and achieve the desired correction. These procedures can be associated with significant pulmonary complications, including atelectasis, pneumonia and respiratory failure. The etiology of some of the respiratory complications is clear: poor inspiratory effort from incision pain and previous pulmonary disease. However, for many patients the direct cause of these complications is not obvious. PURPOSE To delineate the incidence, severity and risks associated with pulmonary complications in the setting of major spine surgery. STUDY DESIGN/SETTING Retrospective chart review study of adult patients undergoing combined anterior-posterior thoracic, lumbar and sacral fusion spine surgery. PATIENT SAMPLE A total of 60 charts were reviewed for this study. OUTCOME MEASURES Radiographic abnormalities correlated with clinical findings, postoperative need for ventilation and lengths of hospital stay were used as outcome measures. METHODS Perioperative pulmonary complications were assessed for 60 patients with spinal deformities who underwent combined anterior-posterior thoracic, lumbar and sacral fusion over a 2-year period. RESULTS One patient was eliminated from analysis because of multiple surgeries during his hospital course. Of the remaining 59 patients, 38 (64%) developed roentgenographic abnormalities. The most common radiographic finding was an effusion found in 66% of these patients, followed by atelectasis in 53%. Twenty-one percent (8 of 38) had infiltrates. Five (5 of 38) or 13% had evidence of partial or complete lobar collapse; in two bronchoscopy was required because of profound hypoxemia. Two patients had pneumonia requiring antibiotic treatment. All but two patients were extubated within 36 hours of surgery. They were kept intubated because of hemodynamic instability. There was no statistically significant difference in the group of patients with and without roentgenographic abnormalities with regard to age, weight, American Society of Anesthesiologists class, smoking history, pulmonary function test results, blood loss, perioperative blood and crystalloid requirement and length of surgery. Patients with radiographic abnormalities were more likely to have had invasion of their thoracic cavity (p=.02) and had a longer mean hospital stay of 13.5 versus 10.2 days (p=.009). CONCLUSION Radiographic abnormalities of the lungs are common after major spine surgery involving both an anterior and posterior approach, especially when the thoracic cavity is invaded. In view of the morbidity and longer hospital stay associated with such findings, close monitoring of pulmonary status with aggressive pulmonary toilet are indicated.
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Affiliation(s)
- Kethy Jules-Elysee
- Department of Anesthesiology, The Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY 10021, USA
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Barkley RA, Brown AC, Hanis CL, Kardia SL, Turner ST, Boerwinkle E. Lack of genetic linkage evidence for a trans-acting factor having a large effect on plasma lipoprotein[a] levels in African Americans. J Lipid Res 2003; 44:1301-5. [PMID: 12730294 DOI: 10.1194/jlr.m300163-jlr200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distribution of plasma lipoprotein[a] (Lp[a]) concentrations, a risk factor for cardiovascular disease, varies greatly among racial groups, with African Americans having values that are shifted toward higher levels than those of whites. The underlying cause of this heterogeneity is unknown, but a role for "trans-acting" factors has been hypothesized. This study used genetic linkage analysis to localize genetic factors influencing Lp[a] levels in African Americans that were absent in other populations; linkage results were analyzed separately in non-Hispanic whites, Hispanic whites, and African Americans. As expected, all three samples showed highly significant linkage at the approximate location of the lysophosphatidic acid locus. The white populations also independently had regions of significant linkage on chromosome 19 (LOD 3.80) and suggestive linkage on chromosomes 12 (LOD 1.60), 14 (LOD 2.56), and 19 (LOD 2.52). No linkage evidence was found to support the hypothesis of another single gene with large effects specifically segregating in African Americans that may account for their elevated Lp[a] levels.
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Affiliation(s)
- Ruth Ann Barkley
- Human Genetics Center and Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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Abstract
BACKGROUND Sentinel lymph node (SLN) dissection in the management of high-risk melanoma and other cancers, such as breast cancer, has recently increased in use. The procedure identifies an SLN by intradermal or intraparenchymal injection of an isosulfan blue dye, a radiocolloid, or both around the primary malignancy. METHODS At the time of selective SLN mapping, 3 to 5 mL of isosulfan blue was injected either intradermally or intraparenchymally around the primary malignancy. From October 1997 to May 2000, 267 patients underwent intraoperative lymphatic mapping with the use of both isosulfan 1% blue dye and radiocolloid injection. Five cases with adverse reactions to isosulfan blue were reviewed. RESULTS We report 2 cases of anaphylaxis and 3 cases of "blue hives" after injection with isosulfan blue of 267 patients who had intraoperative lymphatic mapping by the procedure described above. The 2 patients with anaphylaxis experienced cardiovascular collapse, erythema, perioral edema, urticaria, and uvular edema. The blue hives in 3 patients resolved and transformed to blue patches during the course of the procedures. CONCLUSIONS The incidence of allergic reactions in our series was 2.0%. As physicians expand the role of SLN mapping, they should consider the use of histamine blockers as prophylaxis and have emergency treatment readily available to treat the life- threatening complication of anaphylactic reaction.
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Affiliation(s)
- V M Cimmino
- Department of Surgery, University of Michigan Medical School and University Hospital, Ann Arbor, MI 48109-0932, USA
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Derrickson JP, Fisher AG, Anderson JE, Brown AC. An assessment of various household food security measures in Hawaiì has implications for national food security research and monitoring. J Nutr 2001; 131:749-57. [PMID: 11238755 DOI: 10.1093/jn/131.3.749] [Citation(s) in RCA: 21] [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] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Core Food Security Module (CFSM), the national food security monitoring tool, requires three affirmative responses to categorize households as food insecure. If this tool is unreliable or inaccurate, vulnerable segments of our population may be adversely affected. The objectives of the present study were to assess the credibility of applying the CFSM categorical measure to a population sample from Hawaiì and to assess the concurrent validity of the CFSM, the new face-valid measure and measures adapted from the Radimer/Cornell (RC) measure and Community Childhood Hunger Identification Project. The sample included 1469 respondents gathered through a statewide telephone sample and 144 food pantry recipients. Responses to the 18 CFSM questions were used to create all four measures. The credibility of the CFSM categorical measure was also assessed via comparisons with individual items and with the 1995 national modal CFSM response pattern. Categorical measures were compared across food security prevalence estimates and indices of income and vegetable intake and with the CFSM scale measure. Differences in the modal response pattern between samples affected CFSM categorization. Only 36% of households followed the Hawaiì modal response pattern, and categorization was not consistent with the content of key items. Although 85% of the households were classified as food secure by the CFSM, only 78% were classified as food secure with each of the other food security measures. Concurrent validity of all measures was confirmed. A reassessment of the national CFSM categorical measure appears warranted.
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Shintani TT, Beckham S, Brown AC, O'Connor HK. The Hawaii Diet: ad libitum high carbohydrate, low fat multi-cultural diet for the reduction of chronic disease risk factors: obesity, hypertension, hypercholesterolemia, and hyperglycemia. Hawaii Med J 2001; 60:69-73. [PMID: 11320614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE The purpose of this study was to determine the health effects of a high carbohydrate, low fat multi-cultural traditional diet, The Hawaii Diet, fed ad libitum to an adult population. METHODS Twenty-two adults recruited from various cultural backgrounds in Hawaii were fed, without calorie or portion size restriction, the Hawaii Diet for 21 days. The Hawaii Diet, based on familiar traditional foods from different cultures, is high in complex carbohydrate (77% of calories), low in fat (12% of calories), and moderate in protein (11% of calories). Participants were encouraged to eat to satiety. RESULTS There was a significant weight loss on The Hawaii Diet averaging 10.8 lbs (23.8 kg) (P < .0001). Blood pressure was decreased from an average of 136.0/82.7 mm Hg to 125.5/78.9 mm Hg yielding a significant decrease of 10.4 mm Hg for systolic (P < .01). Beginning diastolic levels were normal so decreases in these values were not significant. Average lipid values also decreased with total serum cholesterol being significantly reduced from 205.3 to 156.9 mg/dl (P < .0001); LDL from 125.9 to 94.9 mg/dl (P < .001); and HDL from 38.3 to 31.3 mg/dl (P < .0005). Triglycerides (238.7 to 152.2 mg/dl) and the Chol:HDL ratio (5.8 to 5.2) improved at marginally significant levels (P < .08). There was also a significant reduction in blood glucose levels from 112.2 to 91.5 mg/dL (P < .01). CONCLUSION The Hawaii Diet consisting of high carbohydrate, low fat ethnic meals appears to have a beneficial influence on weight loss and in decreasing systolic blood pressure, total cholesterol, LDL, and blood glucose values. Marginal improvement occurred for triglyceride levels. There was also a significant drop in HDL levels, however, the Chol:HDL was ratio did not increase. Further studies of longer duration with a control group should be conducted to test the effectiveness of The Hawaii Diet in maintaining these health benefits over a longer period of time.
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Affiliation(s)
- T T Shintani
- Preventive Health Department, Waianae Coast Comprehensive Health Center, 86-260 Farrington Hwy, Waianae, HI 96792, USA
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Abstract
The purpose of this review was to search the scientific literature for dietary compounds that alleviate or exacerbate symptoms of lupus erythematosus (LE) in both animal and human models. A detailed literature review was undertaken to find articles showing a relationship between LE and nutrition by using MEDLINE/INDEX MEDICUS (1950-March 2000) for English-language articles, followed by cross-referencing. Aggravating substances appear to include excess calories, excess protein, high fat (especially saturated and omega-6 polyunsaturated fatty acids), zinc, iron, and L-canavanine found in alfalfa tablets. Possible beneficial dietary compounds include vitamin E, vitamin A (beta-carotene), selenium, fish oils (omega-3 polyunsaturated fatty acids), evening primrose oil, flaxseed, a plant herb (Tripterygium wilfordii), dehydroepiandrosterone, and calcium plus vitamin D (if taking corticosteroids). Some people with systemic LE placed on food allergy elimination diets reported improvement in their LE symptoms; however, this may be related to a decrease of other substances in the diet. Also, although no direct evidence was reported on the beneficial effects of either bromelain or a vegetarian diet (possibly allowing fish), it is suggested that they might be beneficial. Limitations to this research are that the findings are based on relatively few studies, many of which were without control groups or extrapolated from animal models. No large-scale studies have been performed with LE patients to substantiate the benefit, if any, of these individual dietary interventions, and if they were conducted, the remission and exacerbation pattern of LE may interfere with elucidating their effectiveness. Also, dietary changes should not be attempted without a physician's approval/monitoring.
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Affiliation(s)
- A C Brown
- Department of Human Nutrition, Food, & Animal Sciences, University of Hawaii at Manoa, Honolulu, HI 96822, USA
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Cronin-Golomb A, Cronin-Golomb M, Dunne TE, Brown AC, Jain K, Cipolloni PB, Auerbach SH. Facial frequency manipulation normalizes face discrimination in AD. Neurology 2000; 54:2316-8. [PMID: 10881260 DOI: 10.1212/wnl.54.12.2316] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [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: 11/15/2022] Open
Abstract
People with AD have deficient contrast sensitivity and impaired face discrimination. The authors presented photographs of unfamiliar faces of three different sizes to enhance the low, middle, or high facial frequency information (cycles per face). Patients with AD demonstrated normal discrimination of small faces only, indicating that impaired contrast sensitivity at low facial frequencies contributes to their poor face discrimination.
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Abstract
We examined the extent to which 11- to 12-year-old children's (N = 174) self-esteem (SE) stability and level related to their perceptions of various aspects of parent-child communication. Compared to children with stable SE, children with unstable SE reported that their fathers were more critical and psychologically controlling, and less likely to acknowledge their positive behaviors or to show their approval in value-affirming ways. Likewise, children with low SE reported that their fathers exhibited these qualities to a greater extent than did children with high SE. In addition, fathers of children with stable high SE were viewed as especially good at problem solving. Children's SE level related to perceptions of mothers' communication styles very similarly to how it did with fathers'; with respect to SE stability, however, relationships were generally less consistent and frequently absent. Discussion centered on the role of parent-child communication in promoting unstable SE.
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Affiliation(s)
- M H Kernis
- Department of Psychology, University of Georgia, Athens 30602, USA
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Cormack KF, Brown AC, Hastings RP. Behavioural and emotional difficulties in students attending schools for children and adolescents with severe intellectual disability. J Intellect Disabil Res 2000; 44 ( Pt 2):124-129. [PMID: 10898375 DOI: 10.1046/j.1365-2788.2000.00251.x] [Citation(s) in RCA: 27] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND For several decades, researchers and clinicians have been aware of an increased prevalence of psychiatric disorder in children with intellectual disability. However, there are few research studies exploring this issue. METHODS The parents of 123 children attending schools for children with 'severe learning difficulties' completed the Developmental Behaviour Checklist (DBC) in order to identify those children with clinically significant behavioural and emotional problems. Comparisons were made with norms for the DBC and a range of child variables were investigated as possible correlates of disorder. RESULTS Some 50.4% of the children scored above the cut-off on the DBC for psychiatric disorder. The child's severity of physical disability was related most strongly to parental ratings of behavioural and emotional problems. There were also effects for the child's age and the absence of Down's syndrome. CONCLUSIONS The present study confirms previous research findings of a high prevalence of behavioural and emotional difficulties amongst children with intellectual disability, and identifies a number of correlates of disorder which require further investigation.
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Affiliation(s)
- K F Cormack
- Severe Challenging Behaviour Service, NHS Trust, Southampton, UK
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Brown AC, Garrison C. The emerging role of telemedicine in extended-care risk management. Manag Care Interface 2000; 13:66-8. [PMID: 10747694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Davis MD, Brown AC, Blackston RD, Gaughf C, Peterson EA, Gleich GJ, Leiferman KM. Familial eosinophilic cellulitis, dysmorphic habitus, and mental retardation. J Am Acad Dermatol 1998; 38:919-28. [PMID: 9631998 DOI: 10.1016/s0190-9622(98)70588-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [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: 02/07/2023]
Abstract
BACKGROUND Eosinophilic cellulitis is a polymorphous, chronic disease characterized by eosinophil infiltration and granulomatous inflammation. OBJECTIVE Our purpose was to describe the clinical, histologic, and immunohistologic findings in three family members who have had eosinophilic cellulitis since childhood associated with mental retardation and abnormal body habitus. METHODS Family members were evaluated. Multiple skin biopsy specimens were obtained and examined after hematoxylin-and-eosin staining, by immunofluorescence and by electron microscopy. Blood specimens were analyzed by immunoassays for eosinophil granule proteins and eosinophil active cytokines. RESULTS Three short-statured, mentally retarded family members with abnormal body habitus in at least two generations had recurrent eosinophilic cellulitis. Peripheral blood and bone marrow eosinophilia was present. Plasma eosinophil granule major basic protein and eosinophil-derived neurotoxin levels were elevated with normal plasma eosinophil cationic protein levels. Eosinophil survival in culture was increased by patients' plasma and was blocked with monoclonal interleukin-5 antibody. The level of plasma interleukin-5 was elevated. Lesional skin biopsy specimens showed massive staining for three eosinophil granule proteins. Electron microscopy showed eosinophil disruption. CONCLUSION Eosinophilic cellulitis, mental retardation, and abnormal body habitus were likely inherited as a dominant syndrome in this family in which eosinophil involvement was striking.
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Affiliation(s)
- M D Davis
- Department of Dermatology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
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Abstract
In this article, it is noted that poststructural ideas can be useful tools in fostering reflexivity and creativity for clinicians. By examining the process of meaning construction, clinicians can detach from repetitive interpretations of therapy discourse that lead to conversational closure. Four strategies for guiding a reading of family therapy interaction are presented: incitement to discourse, deconstruction, normativity, and the cultural grid of intelligibility. These strategies are used to describe examples of marital therapy discourse. By learning to read therapy as discourse, clinicians may critically examine how meaning is constructed and use that awareness to foster therapeutic conversations.
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Affiliation(s)
- S M Kogan
- Department of Child and Family Development, University of Georgia, Athens 30602, USA.
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Scott H, Brown AC. Is routine drainage of pelvic anastomosis necessary? Am Surg 1996; 62:452-7. [PMID: 8651527] [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: 02/01/2023]
Abstract
The routine use of drains for pelvic anastomosis is controversial. This study was undertaken to determine whether drainage alters leak rate, aids in diagnosing a leak, and/or prevents the need for laparotomy when a leak occurs. Records of 156 consecutive patients who underwent elective resection and pelvic anastomosis for cancer from 1986 to 1994 were retrospectively reviewed. The patients were stratified into two parent groups, I and II. One hundred and eleven Group I patients who routinely had Jackson-Pratt 10-mm drains inserted were subdivided into subgroup I-A (n = 24) with proximal intraoperative diversion and subgroup I-B (n = 87), without diversion. Forty-five Group II patients routinely did not have drains inserted. They were also subdivided, into II-A (n = 3) and II-B (n = 42), i.e., with and without simultaneous diversion, respectively. The overall leak rate was 5.1 per cent (8/156). Subgroups I-A and II-A had leak rates of 8.33 per cent (2/24) and 0 per cent (0/3), respectively. The leak rates were 4.6 per cent (4/87) in subgroup I-B and 4.8 per cent (2/42) in subgroup II-B, with no significant difference (P > 0.05). Also, no significant difference was noted when the overall leak rate for diverted cases was compared with nondiverted ones. Of the four leaks in I-B, three occurred after the drains were removed; two of these required laparotomy, drainage, and diversion. The fourth occurred with the drain in place, but failed to demonstrate feces or pus in the drainage fluid or prevent the need for laparotomy. The presence of a drain did not affect the leak rate (P > 0.10). Drain contents did not aid in diagnosing anastomotic dehiscence. Routine prophylactic use of Jackson-Pratt drains seems unjustified because leaks either occurred after the drains were removed or failed to prevent the need for laparotomy.
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Affiliation(s)
- H Scott
- Department of Surgery, Interfaith Medical Center, Brooklyn, New York, USA
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Pertusi RM, Forman MD, Brown AC. Sweet's syndrome after splenic irradiation for chronic myelogenous leukemia. J Am Osteopath Assoc 1996; 96:366-7. [PMID: 8690626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Sweet's syndrome is defined as acute febrile neutrophilic dermatosis. Characteristic features are fever; peripheral neutrophilia; and painful cutaneous nodules and plaques on the face, neck, trunk, and limbs. Biopsy specimens of these lesions show a mature neutrophilic infiltrate of the dermis. Vasculitis is absent. Sweet's syndrome is associated with malignancy in approximately 20% of reported cases. The pathogenesis is unknown. The authors describe Sweet's syndrome in a 39-year-old man 5 weeks after splenic irradiation for chronic myelogenous leukemia. Treatment with parenteral corticosteroids resulted in dramatic improvement of the patient's condition. The authors discuss the diagnosis of Sweet's syndrome and the fact that it is thought to be cytokine-induced.
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Affiliation(s)
- R M Pertusi
- Department of Medicine, University of North Texas Health Science Center at Fort Worth-Texas College of Osteopathic Medicine 76107-2699, USA
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Abstract
Abstract
Sweet's syndrome is defined as acute febrile neutrophilic dermatosis. Characteristic features are fever; peripheral neutrophilia; and painful cutaneous nodules and plaques on the face, neck, trunk, and limbs. Biopsy specimens of these lesions show a mature neutrophilic infiltrate of the dermis. Vasculitis is absent. Sweet's syndrome is associated with malignancy in approximately 20% of reported cases. The pathogenesis is unknown. The authors describe Sweet's syndrome in a 39year-old man 5 weeks after splenic irradiation for chronic myelogenous leukemia. Treatment with parenteral corticosteroids resulted in dramatic improvement of the patient's condition. The authors discuss the diagnosis of Sweet's syndrome and the fact that it is thought to be cytokine-induced.
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Brown AC. Reviews of state veterinary services--a new disease? Vet Rec 1996; 138:118. [PMID: 8650908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Abstract
The determination of cadmium levels in tissues of the tunicate Pyura stolonifera collected from uncontaminated sites revealed highest concentrations in the liver. After keeping P. stolonifera under laboratory conditions in Cd-containing water for 15 days, cadmium accumulated most markedly in liver tissue. Liver tissue of Cd-exposed specimens was used for the isolation of Cd-binding proteins. Five Cd-binding proteins, which differ in their chromatographic properties, could be purified. At least four of these Cd-binding proteins are heat stable and cysteine-rich. The N-terminal sequence (Met-Asp-Pro-Cys-Asn-Cys-Ala-Glu...) of at least two of these peptides resembles fish (plaice) metallothionein. Unlike vertebrate metallothioneins, P. stolonifera Cd-binding proteins are not N-terminally blocked by acetylation of methionine.
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Affiliation(s)
- W Liebrich
- Department of Biochemistry, University of Cape Town, Rondebosch, South Africa
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Bertiol DJ, Smoker M, Brown AC, Jones MG, Burrows PR. A method based on PCR for the construction of cDNA libraries and probes from small amounts of tissue. Biotechniques 1994; 16:1054-8. [PMID: 8074870] [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: 01/28/2023] Open
Abstract
A PCR-based method is described for the production of cDNA libraries and total cDNA probes from a few milligrams of tissue. Using a model system, we show how a PCR library and PCR probes can be used to identify genes expressed at different levels in two tissues. Small amounts of tissue derived from two plants, one infected with arabis mosaic virus and the other uninfected, were used to make a library and probes. This library and the probes were used to identify viral genes expressed only in the infected plant.
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Affiliation(s)
- D J Bertiol
- AFRC-IACR, Rothamsted Experimental Station Harpenden, Herts, UK
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Abstract
OBJECTIVE The purpose of this study was to evaluate the diets of 96 Hopi fifth- and sixth-grade students on the Hopi reservation in Arizona. DESIGN Dietary food intakes were collected using a 3-day dietary record and were analyzed with a computer software program to obtain information on the intake of energy, protein, carbohydrate, total fat, saturated fat, cholesterol, fiber, 10 vitamins, and six minerals. SETTING The survey was conducted during the health class or homeroom period in the elementary schools located on the Hopi reservation in Arizona. SUBJECTS The survey population consisted of 96 fifth- and sixth-grade Hopi elementary students attending the five schools on the Hopi reservation. MAIN OUTCOME Before data collection we hypothesized the average diet of Hopi elementary students did not meet dietary recommendations (eg, Dietary Goals, Recommended Dietary Allowances (RDAs), and/or National Cancer Institute recommendations). STATISTICS The nutrient analyses and demographic data were analyzed for frequencies and percentages of responses. Descriptive and inferential statistics were calculated where appropriate. RESULTS Results of the analysis revealed a mean daily dietary intake of 2,123 kcal consisting of 35% fat (84 g), 48% carbohydrate (261 g; 38% from sugar), and 17% protein (89 g), with 27 g saturated fat, 442 mg cholesterol, 11 g fiber, and 2,477 mg sodium. At least 97% or 100% of the RDA was met for all analyzed vitamins and minerals except for vitamin D (146 IU; 37% RDA), calcium (874 mg; 82% RDA), and zinc (12 mg; 94% RDA). CONCLUSIONS Given the health problems relatively new to Native Americans, such as diabetes, obesity, liver cirrhosis, hypertension, fetal alcohol syndrome, and increasing rates of heart disease and cancer, dietary modification may benefit them in their adult life. Modifications to meet current recommended dietary goals would include reducing fat to below 30% of energy; cholesterol to less than 250 mg; sodium to lower levels but not below 500 mg/day; and decreasing refined sugars. Carbohydrates would be increased to at least 58% energy; fiber to 20 to 30 g; and vitamin D, calcium, and, possibly, zinc to RDA levels.
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Affiliation(s)
- A C Brown
- Department of Health, Physical Education and Nutrition, Northern Arizona University, Flagstaff 86011
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Abstract
We describe a patient who presented with a history of unexplained exertional dyspnea and pulmonary infiltrates. She was evaluated for interstitial lung disease, presumed to be idiopathic and underwent an open lung biopsy. The pathologic findings were compatible with exogenous lipoid pneumonia and her history revealed longstanding use of intranasal petroleum jelly (Vaseline) at bedtime.
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Affiliation(s)
- A C Brown
- Texas College of Osteopathic Medicine, Department of Internal Medicine, Fort Worth
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Cirocco WC, Brown AC. Anterior resection for the treatment of rectal prolapse: a 20-year experience. Am Surg 1993; 59:265-9. [PMID: 8489090] [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: 01/31/2023]
Abstract
Between 1971 and 1991, 41 patients underwent anterior resection for the treatment of complete rectal prolapse. Anterior resection was performed after full rectal mobilization to the levator ani muscles with reanastomosis (39 hand-sewn and two stapled) carried out to peritonealized distal rectum. The 41 patients comprised 35 women and six men with an average age of 56 years (range, 7-88 years). Postoperative follow-up averaged 6 years (range, 6 months to 18 years). Three patients (7%) suffered recurrent prolapse in 2, 2.5, and 5.5 years, respectively. Mortality was 0 per cent; morbidity was 15 per cent including three incisional herniae, two small bowel obstructions, and one stroke. No pelvic sepsis, abscess, or anastomotic dehiscence occurred. Anal incontinence was a preoperative finding in 21 patients (51%) with rectal prolapse. Nineteen of these patients (90%) noted either improvement or no change in postoperative continence. Anterior resection is a familiar, frequently performed operation that does not require a foreign body or rectal suspension. We believe this to be the procedure of choice for patients with complete rectal prolapse. Anterior resection withstands long-term scrutiny both in terms of recurrence rate and associated complications.
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Affiliation(s)
- W C Cirocco
- Department of Colon and Rectal Surgery, Saint Vincent Health Center, Erie, Pennsylvania
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Brown AC, Smolensky MH, D'Alonzo GE. Day-night variation of airways status in sympathomimetic- and theophylline-treated asthma patients. J Am Osteopath Assoc 1993; 93:321-4, 327-9, 332-3. [PMID: 8514532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Eleven diurnally active asthma patients having a history of nocturnal asthma and treated regularly with albuterol or metaproterenol alone or with twice-daily sustained-release theophylline were evaluated for day-night pattern in peak expiratory flow (PEF) and use of supplemental beta-agonist aerosol for relief of acute asthma. Overall, significant day-night variation was observed in the supplemental use of beta-agonist medication and in airway patency. The patients managed by albuterol or metaproterenol alone used supplemental beta-agonist medication significantly more between 4 AM and 8 AM and also 8 PM and midnight in comparison to 4 PM to 8 PM; this was not true for those treated with both theophylline and beta-agonist aerosol. In patients taking a beta-agonist bronchodilator, the 24-hour mean PEF was greater than in those who also took theophylline, but the day-night variation in PEF was comparable. Supplemental isoproterenol use was significantly correlated with circadian amplitude of the PEF rhythm, but not with the 24-hour mean PEF. The greater the day-night variation in PEF, the greater the reliance on a supplemental beta-agonist bronchodilator.
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Affiliation(s)
- A C Brown
- School of Public Health, University of Texas Health Science Center, Houston
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Lutton JD, da Silva JL, Moqattash S, Brown AC, Levere RD, Abraham NG. Differential induction of heme oxygenase in the hepatocarcinoma cell line (Hep3B) by environmental agents. J Cell Biochem 1992; 49:259-65. [PMID: 1322919 DOI: 10.1002/jcb.240490308] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [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: 12/26/2022]
Abstract
In situ hybridization and Northern analysis of heme oxygenase (HO) mRNA was used to determine the induction and expression of HO by various environmental agents. Exposure of Hep3B cells to hemin (10 microM) for as little as 5 min resulted in significant production of HO transcripts and mRNA expression as seen by in situ hybridization. We followed the pattern of HO transcript accumulation by heme and results indicate that the peak of induction of HO by heme was reached between 10 and 20 minutes. Other metalloporphyrins were all effective in inducing HO mRNA after 1 h exposure. On the other hand, CoCl2 caused accumulation of HO mRNA at a later time than seen with the metalloporphyrins. However, lipopolysaccharide (LPS) gave a more immediate effect on HO induction which was somewhat similar to heme in its time course. Direct measurements of HO activity revealed that enzyme activity could be detected after about 20 min exposure to hemin, and this activity was inhibited by tin protoporphyrin (SnPP). The different pattern of HO mRNA induction by LPS as contrasted with CoCl2 suggests that LPS may act through a different translational factor, or stimulate free radical formation and the subsequent release of heme and induction of HO. These results indicate that heme causes accumulation of HO mRNA by a different mechanism than that of CoCl2. Finally, LPS shares a concomitant effect on induction of HO as an acute phase reactant type protein.
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Affiliation(s)
- J D Lutton
- Department of Medicine, New York Medical College, Valhalla 10595
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