1
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Yeung M, Su CKY, Au SCL. Vaccine-related retinal artery occlusion in adults: a review of the current literature. J Stroke Cerebrovasc Dis 2023; 32:106694. [PMID: 35953410 DOI: 10.1016/j.jstrokecerebrovasdis.2022.106694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Maggie Yeung
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | | | - Sunny Chi Lik Au
- Department of Ophthalmology, Tung Wah Eastern Hospital, Hong Kong.
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2
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Bertoncelli Tanaka M, Smith A, Mannion E, Yeung M, Lloyd J, Silvanto A, Asakra R, Winkler M, Ahmed H. Is immunohistochemistry relevant for the diagnosis of prostate cancer? A 2-year retrospective analysis in a single tertiary centre in the UK. Eur Urol 2023. [DOI: 10.1016/s0302-2838(23)01274-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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3
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Lang ES, Yeung M. When evidence-based medicine and quality improvement collide. CAN J EMERG MED 2022; 24:566-568. [PMID: 36071322 PMCID: PMC9451656 DOI: 10.1007/s43678-022-00377-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/09/2022] [Indexed: 11/04/2022]
Affiliation(s)
- E S Lang
- Department of Emergency Medicine, University of Calgary, Calgary, AB, Canada
| | - M Yeung
- Department of Emergency Medicine, University of Calgary, Calgary, AB, Canada. .,Holy Cross Ambulatory Care Centre, AB, Calgary, Canada.
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4
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Rimbert A, Yeung M, Dalila N, Yu H, Loaiza N, Oldoni F, Van Der Graaf A, Wang S, Said A, Blauw L, Girardeau A, Bray L, Caillaud A, Bloks V, Marrec M, Moulin P, Rensen P, Van De Sluis B, Snieder H, Di Filippo M, Van Der Harst P, Tybjærg-Hansen A, Zimmerman P, Cariou B, Kuivenhoven J. GPR146 gene variants are associated with reduced plasma lipids and cardiovascular health: A novel role for GPR146 in hypolipidemia. Atherosclerosis 2022. [DOI: 10.1016/j.atherosclerosis.2022.06.216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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5
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Wang N, Zhang X, Rothrauff BB, Fritch MR, Chang A, He Y, Yeung M, Liu S, Lipa KE, Lei G, Alexander PG, Lin H. Novel role of estrogen receptor-α on regulating chondrocyte phenotype and response to mechanical loading. Osteoarthritis Cartilage 2022; 30:302-314. [PMID: 34767957 DOI: 10.1016/j.joca.2021.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 02/09/2023]
Abstract
OBJECTIVE In knee cartilage from patients with osteoarthritis (OA), both preserved cartilage and damaged cartilage are observed. In this study, we aim to compare preserved with damaged cartilage to identify the molecule(s) that may be responsible for the mechanical loading-induced differences within cartilage degradation. METHODS Preserved and damaged cartilage were harvested from the same OA knee joint. RNA Sequencing was performed to examine the transcriptomic differences between preserved and damaged cartilage cells. Estrogen receptor-α (ERα) was identified, and its function of was tested through gene knockin and knockout. The role of ERα in mediating chondrocyte response to mechanical loading was examined via compression of chondrocyte-laded hydrogel in a strain-controlled manner. Findings from the studies on human samples were verified in animal models. RESULTS Level of estrogen receptor α (ERα) was significantly reduced in damaged cartilage compared to preserved cartilage, which were observed in both human and mice samples. Knockdown of ESR1, the gene encoding ERα, resulted in an upregulation of senescence- and OA-relevant markers in chondrocytes. Conversely, knockin of ESR1 partially reversed the osteoarthritic and senescent phenotype of OA chondrocytes. Using a three-dimensional (3D) culture model, we demonstrated that mechanical overload significantly suppressed ERα level in chondrocytes with concomitant upregulation of osteoarthritic phenotype. When ESR1 expression was suppressed, mechanical loading enhanced hypertrophic and osteogenic transition. CONCLUSION Our study demonstrates a new estrogen-independent role of ERα in mediating chondrocyte phenotype and its response to mechanical loading, and suggests that enhancing ERα level may represent a new method to treat osteoarthritis.
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Affiliation(s)
- N Wang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Orthopaedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China; Xiangya Third Hospital, Central South University, Changsha, Hunan, China.
| | - X Zhang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Orthopaedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China; Xiangya Third Hospital, Central South University, Changsha, Hunan, China.
| | - B B Rothrauff
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - M R Fritch
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - A Chang
- Department of Bioinformatics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - Y He
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Orthopaedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China; Xiangya Third Hospital, Central South University, Changsha, Hunan, China.
| | - M Yeung
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, 15219, USA.
| | - S Liu
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - K E Lipa
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, 15219, USA.
| | - G Lei
- Department of Orthopaedic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - P G Alexander
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - H Lin
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, 15219, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
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6
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Prasselsperger A, Coughlan M, Breslin N, Yeung M, Arthur C, Donnelly H, White S, Afshari M, Speicher M, Yang R, Villagomez-Bernabe B, Currell FJ, Schreiber J, Dromey B. Real-Time Electron Solvation Induced by Bursts of Laser-Accelerated Protons in Liquid Water. Phys Rev Lett 2021; 127:186001. [PMID: 34767414 DOI: 10.1103/physrevlett.127.186001] [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: 05/20/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Understanding the mechanisms of proton energy deposition in matter and subsequent damage formation is fundamental to radiation science. Here we exploit the picosecond (10^{-12} s) resolution of laser-driven accelerators to track ultrafast solvation dynamics for electrons due to proton radiolysis in liquid water (H_{2}O). Comparing these results with modeling that assumes initial conditions similar to those found in photolysis reveals that solvation time due to protons is extended by >20 ps. Supported by magnetohydrodynamic theory this indicates a highly dynamic phase in the immediate aftermath of the proton interaction that is not accounted for in current models.
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Affiliation(s)
- A Prasselsperger
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Coughlan
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - N Breslin
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Yeung
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - C Arthur
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - H Donnelly
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - S White
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Afshari
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Speicher
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - R Yang
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - B Villagomez-Bernabe
- The Dalton Cumbria Facility and the School of Chemistry, The University of Manchester, Oxford Rd, Manchester M13 9PL, United Kingdom
| | - F J Currell
- The Dalton Cumbria Facility and the School of Chemistry, The University of Manchester, Oxford Rd, Manchester M13 9PL, United Kingdom
| | - J Schreiber
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 85748 Garching, Germany
| | - B Dromey
- Centre for Plasma Physics, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, United Kingdom
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7
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Yeung M, Yeung C. Delivering hope in hepatology: an interview with Professor Grace Lai-hung Wong. Hong Kong Med J 2021; 27:315-317. [PMID: 34413265 DOI: 10.12809/hkmj-hc202108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- M Yeung
- Year 4 MBBS, The University of Hong Kong
| | - C Yeung
- Year 6 MBBS, The University of Hong Kong
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8
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Hendrickson M, Arora S, Sharma M, Yeung M, Byku M. Trends in Hospitalizations and Racial Disparities in Rates of Procedures in Adults Hospitalized with Congenital Heart Disease. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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9
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Arora S, Strassle P, Hendrickson M, Sitammagari K, Qamar A, McRee C, Yeung M, Vavalle J. Cause and risk factors for readmissions after transcatheter aortic valve replacement. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Hospital readmissions following transcatheter aortic valve replacement (TAVR) are associated with higher costs and worse outcomes.
Purpose
Identify causes and risk factors for readmissions after TAVR
Methods
Hospitalizations of adults aged ≥50, with aortic stenosis and undergoing elective TAVR between 2012 and 2016 in the National Readmission Database were analyzed. Multivariable generalized logistic regression, adjusting for age, sex, Charleson Comorbidity Index, primary insurance type, median household income, hospital type and size, were used to assess the effect of inpatient complications, length of stay (LOS), discharge disposition, and TAVR hospital volume on 30-day cardiovascular (CV) and non-cardiovascular (non-CV) readmission.
Results
Between January 2012 and November 2016, 56,858 weighted TAVR hospitalizations were included. The most common causes of readmissions after TAVR were heart failure (23%), infection (17%), gastrointestinal (11%), respiratory (8%), and “other” non-CV causes (8%). The adjusted odds of both CV and non-CV readmissions were significantly higher in patients with acute kidney injury, inpatient LOS ≥5 days, those discharged to skilled nursing facility (SNF) and those treated at medium volume compared with high volume hospitals, Table 1.
Conclusion
Heart failure is the most common cause of readmissions after TAVR. Inpatient incidence of acute kidney injury, as well as longer LOS, SNF discharge and lower hospital TAVR volume were associated with higher odds of 30-day readmissions.
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
- S Arora
- University of North Carolina Hospitals, Chapel Hill, United States of America
| | - P.D Strassle
- University of North Carolina Hospitals, Chapel Hill, United States of America
| | - M.J Hendrickson
- University of North Carolina Hospitals, Chapel Hill, United States of America
| | - K Sitammagari
- Cape Fear Valley Medical Center, Internal Medicine, Fayetteville, United States of America
| | - A Qamar
- New York University Langone Medical Center, Cardiology, New York, United States of America
| | - C McRee
- University of North Carolina Hospitals, Chapel Hill, United States of America
| | - M Yeung
- University of North Carolina Hospitals, Chapel Hill, United States of America
| | - J.P Vavalle
- University of North Carolina Hospitals, Chapel Hill, United States of America
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Yeung M, Busink E. PUK8 Cost-Effectiveness Analysis of Haemodiafiltration (HDF) Versus Haemodialysis (HD) in South Korea. Value Health Reg Issues 2020. [DOI: 10.1016/j.vhri.2020.07.569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Yeung M, Loh EW, Tiong TY, Tam KW. Indwelling pleural catheter versus talc pleurodesis for malignant pleural effusion: a meta-analysis. Clin Exp Metastasis 2020; 37:541-549. [PMID: 32524317 DOI: 10.1007/s10585-020-10042-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023]
Abstract
Malignant pleural effusion (MPE) results from primary mesothelioma or the spreading of metastatic cancer. Both talc pleurodesis (TP) and indwelling pleural catheter (IPC) improve MPE symptoms. We performed a meta-analysis of randomized controlled trials to compare the efficacy of TP with that of IPC in patients with MPE. PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov databases were searched for studies published before February 2020. Individual effect sizes were standardized, and a meta-analysis was conducted to calculate a pooled effect size by using random effects models. In total, 4 trials with 500 patients were reviewed. Difference in pleurodesis success rate and change in dyspnea scores at 4 and 6 weeks between MPE patients treated with IPC and those treated with TP for pleurodesis were nonsignificant. The number of hospital inpatient days was significantly lower among patients who were treated with IPC (weight mean difference: 2.19; 95% confidence interval 0.70-3.67) than among those who were treated with TP. No significant difference was shown in adverse event profile between patients treated with IPC and those treated with TP for pleurodesis. In conclusion, both TP and IPC are equally effective in treating patients with MPE. The number of hospitalization days was significantly lower for patients who were treated with IPC, but the magnitude of the difference is of uncertain clinical importance.
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Affiliation(s)
- Maggie Yeung
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - El-Wui Loh
- Centre for Evidence-Based Health Care, Shuang Ho Hospital, Taipei Medical University, 291, Zhongzheng Road, Zhonghe District, New Taipei City, 23561, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Tung-Yu Tiong
- Division of Thoracic Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Ka-Wai Tam
- Centre for Evidence-Based Health Care, Shuang Ho Hospital, Taipei Medical University, 291, Zhongzheng Road, Zhonghe District, New Taipei City, 23561, Taiwan. .,Division of General Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan. .,Division of General Surgery, Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Cochrane Taiwan, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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12
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Cousens S, Yeung M, Zepf M, Dromey B. Electron trajectories associated with laser-driven coherent synchrotron emission at the front surface of overdense plasmas. Phys Rev E 2020; 101:053210. [PMID: 32575346 DOI: 10.1103/physreve.101.053210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/21/2020] [Indexed: 11/07/2022]
Abstract
We present an in-depth analysis of an ultrafast electron trajectory type that produces attosecond electromagnetic pulses in both the reflected and forward directions during normal incidence, relativistic laser-plasma interactions. Our particle-in-cell simulation results show that for a target which is opaque to the frequency of the driving laser pulse the emission trajectory is synchrotronlike but differs significantly from the previously identified figure-eight type which produces bright attosecond bursts exclusively in the reflected direction. The origin and characteristics of this trajectory type are explained in terms of the driving electromagnetic fields, the opacity of the plasma, and the conservation of canonical momentum.
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Affiliation(s)
- S Cousens
- Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Yeung
- Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - M Zepf
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany.,Helmholtz Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - B Dromey
- Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
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13
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Yeung M, Wroot H, Charnock C, Forbes C, Lafay-Cousin L, Schulte F. Cannabis use in pediatric cancer patients: what are they reading? A review of the online literature. Support Care Cancer 2020; 28:3503-3515. [PMID: 31960125 DOI: 10.1007/s00520-020-05306-2] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 01/14/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Recent changes to the legal status of marijuana in Canada warrant a review of the information that patients and families are accessing online regarding the role of cannabis in cancer. The aims of the current research were to identify the quality of literature available online as well as the themes, and opinion (i.e., pro-, neutral, or anti-cannabis) of online articles. METHODS Searches were conducted using three primary search engines: Google, Yahoo, and DuckDuckGo. Articles were assessed for quality based on a modified scale for evaluating online sources. Content of all unique articles was coded using a qualitative thematic methodology in a line-by-line fashion. Codes were clustered to determine themes within articles. Finally, opinions were determined by examining all articles in a line-by-line fashion. Each statement was coded as either pro-cannabis (positive) or anti-cannabis (negative). RESULTS We found most articles were authored by journalists (39.4%) and MDs (14.1%) and published as news (35.2%) or web articles (28.2%). The content of articles focused on four themes: the reasons for and against cannabis use; the opinions of health care providers; the restrictions placed by governing bodies and the need for additional research, education, and standardization. Article opinions were neutral-pro-cannabis. CONCLUSIONS Health care providers should be aware that the overall quality of information found online is considered "satisfactory." The majority of articles present a pro-cannabis opinion.
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Affiliation(s)
- M Yeung
- University of Calgary, Calgary, Alberta, Canada
| | - H Wroot
- University of Calgary, Calgary, Alberta, Canada
| | - C Charnock
- University of Calgary, Calgary, Alberta, Canada
| | - C Forbes
- University of Calgary, Calgary, Alberta, Canada
| | - L Lafay-Cousin
- University of Calgary, Calgary, Alberta, Canada
- Department of Oncology, Division of Psychosocial Oncology, Cumming School of Medicine, Psychologist, Hematology, Oncology and Transplant Program, University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada
| | - Fiona Schulte
- University of Calgary, Calgary, Alberta, Canada.
- Department of Oncology, Division of Psychosocial Oncology, Cumming School of Medicine, Psychologist, Hematology, Oncology and Transplant Program, University of Calgary, Alberta Children's Hospital, Calgary, Alberta, Canada.
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14
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Bujak A, Weng CF, Silva MJ, Yeung M, Lo L, Ftouni S, Litchfield C, Ko A, Kuykhoven K, van Geelen C, Chandrashekar S, Dawson M, Loi S, Wong S, Dawson SJ. Prospective testing of circulating tumour DNA in metastatic breast cancer facilitates clinical trial enrollment and precision oncology. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz239.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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15
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Kuschel S, Schwab MB, Yeung M, Hollatz D, Seidel A, Ziegler W, Sävert A, Kaluza MC, Zepf M. Controlling the Self-Injection Threshold in Laser Wakefield Accelerators. Phys Rev Lett 2018; 121:154801. [PMID: 30362794 DOI: 10.1103/physrevlett.121.154801] [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: 05/21/2018] [Indexed: 06/08/2023]
Abstract
Controlling the parameters of a laser plasma accelerated electron beam is a topic of intense research with a particular focus placed on controlling the injection phase of electrons into the accelerating structure from the background plasma. An essential prerequisite for high-quality beams is dark-current free acceleration (i.e., no electrons accelerated beyond those deliberately injected). We show that small-scale density ripples in the background plasma are sufficient to cause the uncontrolled (self-)injection of electrons. Such ripples can be as short as ∼50 μm and can therefore not be resolved by standard interferometry. Background free injection with substantially improved beam characteristics (divergence and pointing) is demonstrated in a gas cell designed for a controlled gas flow. The results are supported by an analytical theory as well as 3D particle in cell simulations.
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Affiliation(s)
- S Kuschel
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M B Schwab
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M Yeung
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - D Hollatz
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - A Seidel
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - W Ziegler
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - A Sävert
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M C Kaluza
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M Zepf
- Helmholtz Insitute Jena, Fröbelstieg 3, 07743 Jena, Germany
- Institute of Optics and Quantumelectronics, University of Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- School of Mathematics and Physics, Queens University Belfast, BT7 1NN, United Kingdom
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16
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Warwick J, Dzelzainis T, Dieckmann ME, Schumaker W, Doria D, Romagnani L, Poder K, Cole JM, Alejo A, Yeung M, Krushelnick K, Mangles SPD, Najmudin Z, Reville B, Samarin GM, Symes DD, Thomas AGR, Borghesi M, Sarri G. Experimental Observation of a Current-Driven Instability in a Neutral Electron-Positron Beam. Phys Rev Lett 2017; 119:185002. [PMID: 29219555 DOI: 10.1103/physrevlett.119.185002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Indexed: 06/07/2023]
Abstract
We report on the first experimental observation of a current-driven instability developing in a quasineutral matter-antimatter beam. Strong magnetic fields (≥1 T) are measured, via means of a proton radiography technique, after the propagation of a neutral electron-positron beam through a background electron-ion plasma. The experimentally determined equipartition parameter of ε_{B}≈10^{-3} is typical of values inferred from models of astrophysical gamma-ray bursts, in which the relativistic flows are also expected to be pair dominated. The data, supported by particle-in-cell simulations and simple analytical estimates, indicate that these magnetic fields persist in the background plasma for thousands of inverse plasma frequencies. The existence of such long-lived magnetic fields can be related to analog astrophysical systems, such as those prevalent in lepton-dominated jets.
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Affiliation(s)
- J Warwick
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - T Dzelzainis
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - M E Dieckmann
- Department of Science and Technology (ITN), Linköping University, Campus Norrköping, 60174 Norrköping, Sweden
| | - W Schumaker
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - D Doria
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - L Romagnani
- LULI, Ecole Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau, France
| | - K Poder
- The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW72AZ, United Kingdom
| | - J M Cole
- The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW72AZ, United Kingdom
| | - A Alejo
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - M Yeung
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - K Krushelnick
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 481099-2099, USA
| | - S P D Mangles
- The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW72AZ, United Kingdom
| | - Z Najmudin
- The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College London, London SW72AZ, United Kingdom
| | - B Reville
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - G M Samarin
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - D D Symes
- Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - A G R Thomas
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 481099-2099, USA
- Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - M Borghesi
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
| | - G Sarri
- School of Mathematics and Physics, Queen's University Belfast, University Road, Belfast BT7 1NN, United Kingdom
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Nazzari H, Yeung M, Marceau A, Luong M, Toma M. THE UTILITY OF HOLTER MONITORING IN ASSESSING ELIGIBILITY CRITERIA FOR IVABRADINE IN PATIENTS WITH HEART FAILURE AND REDUCED EJECTION FRACTION. Can J Cardiol 2017. [DOI: 10.1016/j.cjca.2017.07.334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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18
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Raman M, Aghdassi E, Baun M, Yeung M, Fairholm L, Saqui O, Allard JP. Metabolic Bone Disease in Patients Receiving Home Parenteral Nutrition: A Canadian Study and Review. JPEN J Parenter Enteral Nutr 2017; 30:492-6. [PMID: 17047173 DOI: 10.1177/0148607106030006492] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Metabolic bone disease (MBD) is a significant complication in patients receiving long-term home parenteral nutrition (HPN). Pamidronate has been poorly studied in this population. We examine the prevalence and risk factors for MBD and examine changes in bone mineral density (BMD) after pamidronate administration. METHODS First, a chart review of patients receiving HPN for >1 year was performed, and Pearson correlations were used to assess associations between MBD (defined as t score<-1) and risk factors. Second, the effect of IV pamidronate on BMD was studied prospectively in 11 HPN patients. Results were compared using a t-test. RESULTS Charts were reviewed in 25 patients (15 F, 10 M): age, 56.9+/-3.1 years; body mass index (BMI), 21.2+/-0.57 kg/m2; months receiving HPN, 113.2+/-0.09; and days per week receiving HPN, 5.08+/-0.39. MBD was present in 33% of patients for the spine and hip and in 50% for the femoral neck; 24% had previous fractures. There was a significant negative correlation between the duration of HPN and BMD (r=-0.40) for all measurements. From those patients, 11 received IV pamidronate for a mean of 22.2+/-5.4 months. At baseline, their mean HPN treatment duration was 10.6+/-6.3 years. Overall, BMD results showed a trend toward improvement in the mean t score of the spine and hip postpamidronate therapy (pre, -3.1+/-0.75; post, -2.9+/-0.69; p=.07). After excluding 2 patients receiving corticosteroids, the mean t score of the spine showed significant improvement (prepamidronate -3.4+/-0.57 vs post-pamidronate -3.1+/-0.65, p=.036). CONCLUSIONS In our HPN population, 76% had MBD and 24% had previous fractures. The results suggest that these patients may benefit from pamidronate. More studies are needed to assess the efficacy of pamidronate.
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Affiliation(s)
- M Raman
- University Health Network, Toronto, Canada
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19
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Abstract
Objective Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia. Methods A systematic search was performed in duplicate for studies investigating the outcome of hip arthroscopy in the setting of hip dysplasia up to July 2015. Study parameters including sample size, definition of dysplasia, outcomes measures, and re-operation rates were obtained. Furthermore, the levels of evidence of studies were collected and quality assessment was performed. Results The systematic review identified 18 studies investigating hip arthroscopy in the setting of hip dysplasia, with 889 included patients. Criteria used by the studies to diagnose hip dysplasia and borderline hip dysplasia included centre edge angle in 72% of studies but the range of angles were quite variable. Although 89% of studies reported improved post-operative outcome scores in the setting of hip dysplasia, revision rates were considerable (14.1%), with 9.6% requiring conversion to total hip arthroplasty. Conclusion The available orthopaedic literature suggests that although improved outcomes are seen in hip arthroscopy in the setting of hip dysplasia, there is a high rate of re-operation and conversion to total hip arthroplasty. Furthermore, the criteria used to define hip dysplasia vary considerably among published studies. Cite this article: M. Yeung, M. Kowalczuk, N. Simunovic, O. R. Ayeni. Hip arthroscopy in the setting of hip dysplasia: A systematic review. Bone Joint Res 2016;5:225–231. DOI: 10.1302/2046-3758.56.2000533.
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Affiliation(s)
- M Yeung
- McMaster University, 1200 Main St W, Room 4E15, Hamilton, Ontario L8N 3Z5, Canada
| | - M Kowalczuk
- McMaster University, 1200 Main St W, Room 4E15, Hamilton, Ontario L8N 3Z5, Canada
| | - N Simunovic
- McMaster University, 293 Wellington St. N., Suite 110, Hamilton, Ontario L8L 8E7, Canada
| | - O R Ayeni
- McMaster University, 1200 Main St W, Room 4E15, Hamilton, Ontario L8N 3Z5, Canada
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20
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Corvan DJ, Dzelzainis T, Hyland C, Nersisyan G, Yeung M, Zepf M, Sarri G. Optical measurement of the temporal delay between two ultra-short and focussed laser pluses. Opt Express 2016; 24:3127-3136. [PMID: 26906877 DOI: 10.1364/oe.24.003127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Temporal overlapping of ultra-short and focussed laser pulses is a particularly challenging task, as this timescale lies orders of magnitude below the typical range of fast electronic devices. Here we present an optical technique that allows for the measurement of the temporal delay between two focussed and ultra-short laser pulses. This method is virtually applicable to any focussing geometry and relative intensity of the two lasers. Experimental implementation of this technique provides excellent quantitative agreement with theoretical expectations. The proposed technique will prove highly beneficial for high-power multiple-beam laser experiments.
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21
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Yeung M, Bierbach J, Eckner E, Rykovanov S, Kuschel S, Sävert A, Förster M, Rödel C, Paulus GG, Cousens S, Coughlan M, Dromey B, Zepf M. Noncollinear Polarization Gating of Attosecond Pulse Trains in the Relativistic Regime. Phys Rev Lett 2015; 115:193903. [PMID: 26588384 DOI: 10.1103/physrevlett.115.193903] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Indexed: 06/05/2023]
Abstract
High order harmonics generated at relativistic intensities have long been recognized as a route to the most powerful extreme ultraviolet pulses. Reliably generating isolated attosecond pulses requires gating to only a single dominant optical cycle, but techniques developed for lower power lasers have not been readily transferable. We present a novel method to temporally gate attosecond pulse trains by combining noncollinear and polarization gating. This scheme uses a split beam configuration which allows pulse gating to be implemented at the high beam fluence typical of multi-TW to PW class laser systems. Scalings for the gate width demonstrate that isolated attosecond pulses are possible even for modest pulse durations achievable for existing and planned future ultrashort high-power laser systems. Experimental results demonstrating the spectral effects of temporal gating on harmonic spectra generated by a relativistic laser plasma interaction are shown.
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Affiliation(s)
- M Yeung
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - J Bierbach
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - E Eckner
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - S Rykovanov
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - S Kuschel
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - A Sävert
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M Förster
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - C Rödel
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - G G Paulus
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - S Cousens
- Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, United Kingdom
| | - M Coughlan
- Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, United Kingdom
| | - B Dromey
- Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, United Kingdom
| | - M Zepf
- Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
- Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
- Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN, United Kingdom
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22
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Bin JH, Ma WJ, Wang HY, Streeter MJV, Kreuzer C, Kiefer D, Yeung M, Cousens S, Foster PS, Dromey B, Yan XQ, Ramis R, Meyer-ter-Vehn J, Zepf M, Schreiber J. Ion Acceleration Using Relativistic Pulse Shaping in Near-Critical-Density Plasmas. Phys Rev Lett 2015; 115:064801. [PMID: 26296119 DOI: 10.1103/physrevlett.115.064801] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Indexed: 06/04/2023]
Abstract
Ultraintense laser pulses with a few-cycle rising edge are ideally suited to accelerating ions from ultrathin foils, and achieving such pulses in practice represents a formidable challenge. We show that such pulses can be obtained using sufficiently strong and well-controlled relativistic nonlinearities in spatially well-defined near-critical-density plasmas. The resulting ultraintense pulses with an extremely steep rising edge give rise to significantly enhanced carbon ion energies consistent with a transition to radiation pressure acceleration.
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Affiliation(s)
- J H Bin
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
- Max-Planck-Institute für Quantenoptik, D-85748 Garching, Germany
| | - W J Ma
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
- State Key Laboratory of Nuclear Physics and Technology and Key Lab of High Energy Density Physics Simulation, CAPT, Peking University, Beijing 100871, People's Republic of China
| | - H Y Wang
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
- Max-Planck-Institute für Quantenoptik, D-85748 Garching, Germany
- State Key Laboratory of Nuclear Physics and Technology and Key Lab of High Energy Density Physics Simulation, CAPT, Peking University, Beijing 100871, People's Republic of China
| | - M J V Streeter
- The John Adams Institute for Accelerator Science, Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom
| | - C Kreuzer
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - D Kiefer
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - M Yeung
- Department of Physics and Astronomy, Centre for Plasma Physics, Queens University, Belfast BT7 1NN, United Kingdom
| | - S Cousens
- Department of Physics and Astronomy, Centre for Plasma Physics, Queens University, Belfast BT7 1NN, United Kingdom
| | - P S Foster
- Department of Physics and Astronomy, Centre for Plasma Physics, Queens University, Belfast BT7 1NN, United Kingdom
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon 0X11 0QX, United Kingdom
| | - B Dromey
- Department of Physics and Astronomy, Centre for Plasma Physics, Queens University, Belfast BT7 1NN, United Kingdom
| | - X Q Yan
- State Key Laboratory of Nuclear Physics and Technology and Key Lab of High Energy Density Physics Simulation, CAPT, Peking University, Beijing 100871, People's Republic of China
| | - R Ramis
- E.T.S.I Aeronáuticos, Universidad Politécnica de Madrid, E-28040 Madrid, Spain
| | - J Meyer-ter-Vehn
- Max-Planck-Institute für Quantenoptik, D-85748 Garching, Germany
| | - M Zepf
- Department of Physics and Astronomy, Centre for Plasma Physics, Queens University, Belfast BT7 1NN, United Kingdom
- Helmholtz-Institut-Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - J Schreiber
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
- Max-Planck-Institute für Quantenoptik, D-85748 Garching, Germany
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23
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Yeung M, Cooper I, Jones A, Jenkins S. Professional sexual boundaries – an observational study between Singapore, Hong Kong and Australia. Physiotherapy 2015. [DOI: 10.1016/j.physio.2015.03.099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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24
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Ma WJ, Bin JH, Wang HY, Yeung M, Kreuzer C, Streeter M, Foster PS, Cousens S, Kiefer D, Dromey B, Yan XQ, Meyer-ter-Vehn J, Zepf M, Schreiber J. Bright subcycle extreme ultraviolet bursts from a single dense relativistic electron sheet. Phys Rev Lett 2014; 113:235002. [PMID: 25526132 DOI: 10.1103/physrevlett.113.235002] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Indexed: 06/04/2023]
Abstract
Double-foil targets separated by a low density plasma and irradiated by a petawatt-class laser are shown to be a copious source of coherent broadband radiation. Simulations show that a dense sheet of relativistic electrons is formed during the interaction of the laser with the tenuous plasma between the two foils. The coherent motion of the electron sheet as it transits the second foil results in strong broadband emission in the extreme ultraviolet, consistent with our experimental observations.
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Affiliation(s)
- W J Ma
- Fakultät für Physik, Ludwig-Maximilians-University, Am Coulombwall 1, D-85748 Garching, Germany
| | - J H Bin
- Fakultät für Physik, Ludwig-Maximilians-University, Am Coulombwall 1, D-85748 Garching, Germany and Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany
| | - H Y Wang
- Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany and State Key Laboratory of Nuclear Physics and Technology & Center of Applied Physics and Technology, Peking University, Beijing 100871, China
| | - M Yeung
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom and Helmholtz Institute Jena, 07743 Jena, Germany
| | - C Kreuzer
- Fakultät für Physik, Ludwig-Maximilians-University, Am Coulombwall 1, D-85748 Garching, Germany
| | - M Streeter
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - P S Foster
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom and Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - S Cousens
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - D Kiefer
- Fakultät für Physik, Ludwig-Maximilians-University, Am Coulombwall 1, D-85748 Garching, Germany
| | - B Dromey
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - X Q Yan
- State Key Laboratory of Nuclear Physics and Technology & Center of Applied Physics and Technology, Peking University, Beijing 100871, China
| | - J Meyer-ter-Vehn
- Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany
| | - M Zepf
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom and Helmholtz Institute Jena, 07743 Jena, Germany
| | - J Schreiber
- Fakultät für Physik, Ludwig-Maximilians-University, Am Coulombwall 1, D-85748 Garching, Germany and Max-Planck-Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany
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25
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Sarri G, Corvan DJ, Schumaker W, Cole JM, Di Piazza A, Ahmed H, Harvey C, Keitel CH, Krushelnick K, Mangles SPD, Najmudin Z, Symes D, Thomas AGR, Yeung M, Zhao Z, Zepf M. Ultrahigh Brilliance Multi-MeV γ-Ray Beams from Nonlinear Relativistic Thomson Scattering. Phys Rev Lett 2014; 113:224801. [PMID: 25494074 DOI: 10.1103/physrevlett.113.224801] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Indexed: 06/04/2023]
Abstract
We report on the generation of a narrow divergence (θ_{γ}<2.5 mrad), multi-MeV (E_{max}≈18 MeV) and ultrahigh peak brilliance (>1.8×10^{20} photons s^{-1} mm^{-2} mrad^{-2} 0.1% BW) γ-ray beam from the scattering of an ultrarelativistic laser-wakefield accelerated electron beam in the field of a relativistically intense laser (dimensionless amplitude a_{0}≈2). The spectrum of the generated γ-ray beam is measured, with MeV resolution, seamlessly from 6 to 18 MeV, giving clear evidence of the onset of nonlinear relativistic Thomson scattering. To the best of our knowledge, this photon source has the highest peak brilliance in the multi-MeV regime ever reported in the literature.
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Affiliation(s)
- G Sarri
- School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom
| | - D J Corvan
- School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom
| | - W Schumaker
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA
| | - J M Cole
- The John Adams Institute for Accelerator Science, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom
| | - A Di Piazza
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - H Ahmed
- School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom
| | - C Harvey
- School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom
| | - C H Keitel
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - K Krushelnick
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA
| | - S P D Mangles
- The John Adams Institute for Accelerator Science, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom
| | - Z Najmudin
- The John Adams Institute for Accelerator Science, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom
| | - D Symes
- Central Laser Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - A G R Thomas
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA
| | - M Yeung
- Helmholtz Institute Jena, Fröbelstieg 3, 07743 Jena, Germany
| | - Z Zhao
- Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109-2099, USA
| | - M Zepf
- School of Mathematics and Physics, The Queen's University of Belfast, BT7 1NN Belfast, United Kingdom and Helmholtz Institute Jena, Fröbelstieg 3, 07743 Jena, Germany
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26
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Hage A, Landgraf B, Taylor M, Wünsche M, Gangolf T, Höppner H, Prandolini MJ, Riedel R, Schulz M, Tavella F, Willner A, Yeung M, Paulus GG, Spielmann C, Dromey B, Zepf M. New design of a multi-jet target for quasi phase matching. Rev Sci Instrum 2014; 85:103105. [PMID: 25362369 DOI: 10.1063/1.4897269] [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] [Indexed: 06/04/2023]
Abstract
An improved dual-gas quasi-phase matching (QPM) foil target for high harmonic generation (HHG) is presented. The target can be setup with 12 individual gas inlets each feeding multiple nozzles separated by a minimum distance of 10 μm. Three-dimensional gas density profiles of these jets were measured using a Mach-Zehnder Interferometer. These measurements reveal how the jets influence the density of gas in adjacent jets and how this leads to increased local gas densities. The analysis shows that the gas profiles of the jets are well defined up to a distance of about 300 μm from the orifice. This target design offers experimental flexibility, not only for HHG/QPM investigations, but also for a wide range of experiments due to the large number of possible jet configurations. We demonstrate the application to controlled phase tuning in the extreme ultraviolet using a 1 kHz-10 mJ-30 fs-laser system where interference between two jets in the spectral range from 17 to 30 nm was observed.
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Affiliation(s)
- A Hage
- Deutsches Elektronensynchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - B Landgraf
- Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - M Taylor
- School of Mathematics and Physics, Queen's University, University Road, Belfast BT7 1NN, United Kingdom
| | - M Wünsche
- Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - T Gangolf
- Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - H Höppner
- Deutsches Elektronensynchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - M J Prandolini
- Helmholtzinstitut Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - R Riedel
- Helmholtzinstitut Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - M Schulz
- Deutsches Elektronensynchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - F Tavella
- Helmholtzinstitut Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - A Willner
- Deutsches Elektronensynchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - M Yeung
- School of Mathematics and Physics, Queen's University, University Road, Belfast BT7 1NN, United Kingdom
| | - G G Paulus
- Institute of Optics and Quantum Electronics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany
| | - C Spielmann
- Helmholtzinstitut Jena, Helmholtzweg 4, 07743 Jena, Germany
| | - B Dromey
- School of Mathematics and Physics, Queen's University, University Road, Belfast BT7 1NN, United Kingdom
| | - M Zepf
- School of Mathematics and Physics, Queen's University, University Road, Belfast BT7 1NN, United Kingdom
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27
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Yeung M, Dromey B, Cousens S, Dzelzainis T, Kiefer D, Schreiber J, Bin JH, Ma W, Kreuzer C, Meyer-ter-Vehn J, Streeter MJV, Foster PS, Rykovanov S, Zepf M. Dependence of laser-driven coherent synchrotron emission efficiency on pulse ellipticity and implications for polarization gating. Phys Rev Lett 2014; 112:123902. [PMID: 24724650 DOI: 10.1103/physrevlett.112.123902] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Indexed: 06/03/2023]
Abstract
The polarization dependence of laser-driven coherent synchrotron emission transmitted through thin foils is investigated experimentally. The harmonic generation process is seen to be almost completely suppressed for circular polarization opening up the possibility of producing isolated attosecond pulses via polarization gating. Particle-in-cell simulations suggest that current laser pulses are capable of generating isolated attosecond pulses with high pulse energies.
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Affiliation(s)
- M Yeung
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - B Dromey
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - S Cousens
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - T Dzelzainis
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - D Kiefer
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - J Schreiber
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - J H Bin
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - W Ma
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany and Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - C Kreuzer
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - J Meyer-ter-Vehn
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, D-85748 Garching, Germany
| | - M J V Streeter
- Blackett Laboratory, Imperial College London, London SW7 2BZ, United Kingdom
| | - P S Foster
- Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom
| | - S Rykovanov
- Fakultät für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany
| | - M Zepf
- Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, United Kingdom and Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena, Germany
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Abstract
A ubiquitous nuclear protein, the high-mobility group box 1 (HMGB1), is secreted by activated macrophages/monocytes and leaked passively from injured cells. HMGB1 functions as a mediator of infection- and injury-elicited inflammatory diseases. Here, we describe a semiquantitative immuno-blotting method to measure the released HMGB1 in human serum, in comparison with a commercially available HMGB1 ELISA technique.
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Affiliation(s)
- Haichao Wang
- Laboratory of Emergency Medicine, The Feinstein Institute for Medical Research, North Shore-LIJ Health System, 350 Community Drive, 11030, Manhasset, NY, USA,
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29
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Kang H, Metz LM, Traboulsee AL, Eliasziw M, Zhao GJ, Cheng Y, Zhao Y, Li DKB, Traboulsee A, Li D, Riddehough A, Cheng Y, Lam K, Lee A, Zhao GJ, Vorobeychik G, Metz L, Yeung M, Yong VW, Hill M, Cerchiaro G, Ma C, Topor T, Blevins G, Marriott J, Kremenchutzky M, Freedman M, Lee L, Duquette P, Antel J, Grand’Maison F, Thibault M, Bhan V, Eliasziw M. Application and a proposed modification of the 2010 McDonald criteria for the diagnosis of multiple sclerosis in a Canadian cohort of patients with clinically isolated syndromes. Mult Scler 2013; 20:458-63. [DOI: 10.1177/1352458513501230] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: The 2005 and 2010 McDonald criteria utilize magnetic resonance imaging (MRI) to provide evidence of disease dissemination in space (DIS) and time (DIT) for the diagnosis of multiple sclerosis (MS) in patients who have clinically isolated syndromes (CIS). Methods: Data from 109 CIS patients not satisfying the 2005 criteria at entry into a randomized controlled minocycline trial were analyzed to determine the proportion who would have been diagnosed with MS at screening based on 2010 criteria. The impact of including symptomatic, as well as asymptomatic, MRI lesions to confirm DIT was also explored. Results: Thirty percent (33/109) of patients, retrospectively, met the 2010 criteria for a diagnosis of MS at baseline. When both symptomatic and asymptomatic lesions were used to confirm DIT, three additional patients met the 2010 criteria. There was a significant 10.1% increase in the proportion of patients who met the 2010 DIS criteria, compared with the 2005 DIS criteria; however, two patients satisfied the 2005 DIS but not 2010 DIS criteria. Conclusion: Using 2010 McDonald criteria, 30% of the CIS patients could be diagnosed with MS using a single MRI scan. Inclusion of symptomatic lesions in the DIT criteria further increases this proportion to 33%.
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Affiliation(s)
- H Kang
- Department of Radiology, University of British Columbia (UBC), Canada
| | - LM Metz
- Department of Clinical Neurosciences, University of Calgary, Canada
| | - AL Traboulsee
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
- UBC MS/MRI Research Group, Canada
| | - M Eliasziw
- Department of Public Health and Community Medicine, Tufts University, USA
| | - GJ Zhao
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
- UBC MS/MRI Research Group, Canada
| | - Y Cheng
- Department of Radiology, University of British Columbia (UBC), Canada
- UBC MS/MRI Research Group, Canada
| | - Y Zhao
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
- UBC MS/MRI Research Group, Canada
| | - DKB Li
- Department of Radiology, University of British Columbia (UBC), Canada
- Division of Neurology, Department of Medicine, University of British Columbia, Canada
- UBC MS/MRI Research Group, Canada
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30
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Yeung M, Dromey B, Adams D, Cousens S, Hörlein R, Nomura Y, Tsakiris GD, Zepf M. Beaming of high-order harmonics generated from laser-plasma interactions. Phys Rev Lett 2013; 110:165002. [PMID: 23679609 DOI: 10.1103/physrevlett.110.165002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Indexed: 06/02/2023]
Abstract
Beam divergences of high-order extreme ultraviolet harmonics from intense laser interactions with steep plasma density gradients are studied through experiment and Fourier analysis of the harmonic spatial phase. We show that while emission due to the relativistically oscillating mirror mechanism can be explained by ponderomotive surface denting, in agreement with previous results, the divergence of the emission due to the coherent wake emission mechanism requires a combination of the dent phase and an intrinsic emission phase. The temporal dependence of the divergences for both mechanisms is highlighted while it is also shown that the coherent wake emission divergence can be small in circumstances where the phase terms compensate each other.
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Affiliation(s)
- M Yeung
- Department of Physics and Astronomy, Queen's University Belfast, BT7 1NN Belfast, United Kingdom
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31
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Rödel C, an der Brügge D, Bierbach J, Yeung M, Hahn T, Dromey B, Herzer S, Fuchs S, Pour AG, Eckner E, Behmke M, Cerchez M, Jäckel O, Hemmers D, Toncian T, Kaluza MC, Belyanin A, Pretzler G, Willi O, Pukhov A, Zepf M, Paulus GG. Harmonic generation from relativistic plasma surfaces in ultrasteep plasma density gradients. Phys Rev Lett 2012; 109:125002. [PMID: 23005951 DOI: 10.1103/physrevlett.109.125002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Indexed: 06/01/2023]
Abstract
Harmonic generation in the limit of ultrasteep density gradients is studied experimentally. Observations reveal that, while the efficient generation of high order harmonics from relativistic surfaces requires steep plasma density scale lengths (L(p)/λ < 1), the absolute efficiency of the harmonics declines for the steepest plasma density scale length L(p)→0, thus demonstrating that near-steplike density gradients can be achieved for interactions using high-contrast high-intensity laser pulses. Absolute photon yields are obtained using a calibrated detection system. The efficiency of harmonics reflected from the laser driven plasma surface via the relativistic oscillating mirror was estimated to be in the range of 10(-4)-10(-6) of the laser pulse energy for photon energies ranging from 20-40 eV, with the best results being obtained for an intermediate density scale length.
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Affiliation(s)
- C Rödel
- Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Jena, Germany
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32
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Palmer CAJ, Schreiber J, Nagel SR, Dover NP, Bellei C, Beg FN, Bott S, Clarke RJ, Dangor AE, Hassan SM, Hilz P, Jung D, Kneip S, Mangles SPD, Lancaster KL, Rehman A, Robinson APL, Spindloe C, Szerypo J, Tatarakis M, Yeung M, Zepf M, Najmudin Z. Rayleigh-Taylor instability of an ultrathin foil accelerated by the radiation pressure of an intense laser. Phys Rev Lett 2012; 108:225002. [PMID: 23003606 DOI: 10.1103/physrevlett.108.225002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Indexed: 06/01/2023]
Abstract
We report experimental evidence for a Rayleigh-Taylor-like instability driven by radiation pressure of an ultraintense (10(21) W/cm(2)) laser pulse. The instability is witnessed by the highly modulated profile of the accelerated proton beam produced when the laser irradiates a 5 nm diamondlike carbon (90% C, 10% H) target. Clear anticorrelation between bubblelike modulations of the proton beam and transmitted laser profile further demonstrate the role of the radiation pressure in modulating the foil. Measurements of the modulation wavelength, and of the acceleration from Doppler-broadening of back-reflected light, agree quantitatively with particle-in-cell simulations performed for our experimental parameters and which confirm the existence of this instability.
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Affiliation(s)
- C A J Palmer
- Blackett Laboratory, Imperial College, London SW7 2BW, United Kingdom
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33
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Zhao X, Boenisch O, Yeung M, Mfarrej B, Yang S, Turka LA, Sayegh MH, Iacomini J, Yuan X. Critical role of proinflammatory cytokine IL-6 in allograft rejection and tolerance. Am J Transplant 2012; 12:90-101. [PMID: 21992708 DOI: 10.1111/j.1600-6143.2011.03770.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The proinflammatory cytokine IL-6 plays an important role in controlling T-cell differentiation, especially the development of Th17 and regulatory T cells. To determine the function of IL-6 in regulating allograft rejection and tolerance, BALB/c cardiac grafts were transplanted into wild-type or IL-6-deficient C57BL/6 mice. We observed that production of IL-6 and IFN-γ was upregulated during allograft rejection in untreated wild-type mice. In IL-6-deficient mice, IFN-γ production was greater than that observed in wild-type controls, suggesting that IL-6 production affects Th1/Th2 balance during allograft rejection. CD28-B7 blockade by CTLA4-Ig inhibited IFN-γ production in C57BL/6 recipients, but had no effect on the production of IL-6. Although wild-type C57BL/6 recipients treated with CTLA4-Ig rejected fully MHC-mismatched BALB/c heart transplants, treatment of IL-6-deficient mice with CTLA4-Ig resulted in graft acceptance. Allograft acceptance appeared to result from the combined effect of costimulatory molecule blockade and IL-6-deficiency, which limited the differentiation of effector cells and promoted the migration of regulatory T cells into the grafts. These data suggest that the blockade of IL-6, or its signaling pathway, when combined with strategies that inhibit Th1 responses, has a synergistic effect on the promotion of allograft acceptance. Thus, targeting the effects of IL-6 production may represent an important part of costimulation blockade-based strategies to promote allograft acceptance and tolerance.
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Affiliation(s)
- X Zhao
- Transplantation Research Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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34
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Willner A, Tavella F, Yeung M, Dzelzainis T, Kamperidis C, Bakarezos M, Adams D, Schulz M, Riedel R, Hoffmann MC, Hu W, Rossbach J, Drescher M, Papadogiannis NA, Tatarakis M, Dromey B, Zepf M. Coherent control of high harmonic generation via dual-gas multijet arrays. Phys Rev Lett 2011; 107:175002. [PMID: 22107529 DOI: 10.1103/physrevlett.107.175002] [Citation(s) in RCA: 3] [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: 07/08/2011] [Indexed: 05/31/2023]
Abstract
High harmonic generation (HHG) is a central driver of the rapidly growing field of ultrafast science. We present a novel quasiphase-matching (QPM) concept with a dual-gas multijet target leading, for the first time, to remarkable phase control between multiple HHG sources (>2) within the Rayleigh range. The alternating jet structure with driving and matching zones shows perfect coherent buildup for up to six QPM periods. Although not in the focus of the proof-of-principle studies presented here, we achieved competitive conversion efficiencies already in this early stage of development.
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Affiliation(s)
- A Willner
- Deutsches Elektronen Synchrotron, Notkestrasse 85, 22607 Hamburg, Germany
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35
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Yeung M, Zepf M, Geissler M, Dromey B. Angularly separated harmonic generation from intense laser interaction with blazed diffraction gratings. Opt Lett 2011; 36:2333-2335. [PMID: 21686011 DOI: 10.1364/ol.36.002333] [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] [Indexed: 05/30/2023]
Abstract
We made numerical simulations of the generation of narrowband beams of extreme ultraviolet radiation from intense laser interaction with a blazed grating surface. Strong fifth harmonic emission into its blazed diffraction order was observed as well as heavy suppression of the fundamental frequency with comparison to a typical harmonic spectrum from a flat target. The results demonstrate a new highly efficient method of generating near-monochromatic harmonics from the fundamental with minimal effect on the pulse duration.
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Affiliation(s)
- M Yeung
- Centre for Plasma Physics, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, UK.
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36
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Riella LV, Watanabe T, Sage PT, Yang J, Yeung M, Azzi J, Vanguri V, Chandraker A, Sharpe AH, Sayegh MH, Najafian N. Essential role of PDL1 expression on nonhematopoietic donor cells in acquired tolerance to vascularized cardiac allografts. Am J Transplant 2011; 11:832-40. [PMID: 21401869 DOI: 10.1111/j.1600-6143.2011.03451.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The PD1:PDL1 pathway is an essential negative costimulatory pathway that plays a key role in regulating the alloimune response. PDL1 is expressed not only on antigen-presenting cells (APCs) but also cardiac endothelium. In this study, we investigated the importance of PDL1 expression on donor cardiac allograft in acquired transplantation tolerance in a fully MHC-mismatched model. We generated PDL1 chimeric mice on B6 background that expressed PDL1 on either hematopoietic cells or nonhematopoietic cells of the heart. Sham animals were used as controls. These hearts were then transplanted into BALB/c recipients and treated with CTLA4-Ig to induce tolerance. Cardiac endothelium showed significant expression of PDL1, which was upregulated upon transplantation. While the absence of PDL1 on hematopoietic cells of the heart resulted in delayed rejection and prevented long-term tolerance in most but not all recipients, we observed an accelerated and early graft rejection of all donor allografts that lacked PDL1 on the endothelium. Moreover, PDL1-deficient endothelium hearts had significant higher frequency of IFN-γ-producing alloreactive cells as well as higher frequency of CD8(+) effector T cells. These findings demonstrate that PDL1 expression mainly on donor endothelium is functionally important in a fully allogeneic mismatched model for the induction of cardiac allograft tolerance.
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Affiliation(s)
- L V Riella
- Transplantation Research Center, Renal Division, Brigham & Women's Hospital, Children's Hospital Boston, MA, USA
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37
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Yamaura K, Watanabe T, Boenisch O, Yeung M, Yang S, Magee CN, Padera R, Datta S, Schatton T, Kamimura Y, Azuma M, Najafian N. In vivo function of immune inhibitory molecule B7-H4 in alloimmune responses. Am J Transplant 2010; 10:2355-62. [PMID: 21143433 DOI: 10.1111/j.1600-6143.2010.03250.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
B7 ligands deliver both costimulatory and coinhibitory signals to the CD28 family of receptors on T lymphocytes, the balance between which determines the ultimate immune response. Although B7-H4, a recently discovered member of the B7 family, is known to negatively regulate T cell immunity in autoimmunity and cancer, its role in solid organ allograft rejection and tolerance has not been established. Targeting the B7-H4 molecule by a blocking antibody or use of B7-H4(-/-) mice as recipients of fully MHC-mismatched cardiac allografts did not affect graft survival. However, B7-H4 blockade resulted in accelerated allograft rejection in CD28-deficient recipients. B7-1/B7-2-double-deficient recipients are truly independent of CD28/CTLA-4:B7 signals and usually accept MHC-mismatched heart allografts. Blockade of B7-H4 in these mice also precipitated rejection, demonstrating regulatory function of this molecule independent of an intact CD28/CTLA-4:B7 costimulatory pathway. Accelerated allograft rejection was always accompanied by increased frequencies of alloreactive IFN-γ-, IL-4- and Granzyme B-producing splenocytes. Finally, intact recipient, but not donor, B7-H4 is essential for prolongation of allograft survival by blocking CD28/CTLA4:B7 pathway using CTLA4-Ig. These data are the first to provide evidence of the regulatory effects of B7-H4 in alloimmune responses in a murine model of solid organ transplantation.
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Affiliation(s)
- K Yamaura
- Transplantation Research Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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38
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Casper D, Lekhraj R, Pidel A, Yeung M, Myrie A, Pilla A. P2.100 Pulsed electromagnetic flelds modulate nitric oxide pathways in dopaminergic neurons. Parkinsonism Relat Disord 2009. [DOI: 10.1016/s1353-8020(09)70451-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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39
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So WKW, Marsh G, Ling WM, Leung FY, Lo JCK, Yeung M, Li GKH. The symptom cluster of fatigue, pain, anxiety, and depression and the effect on the quality of life of women receiving treatment for breast cancer: a multicenter study. Oncol Nurs Forum 2009; 36:E205-14. [PMID: 19581224 DOI: 10.1188/09.onf.e205-e214] [Citation(s) in RCA: 171] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE/OBJECTIVES To examine the symptom cluster of fatigue, pain, anxiety, and depression and its effect on the quality of life (QOL) of women receiving chemotherapy or radiotherapy for breast cancer. DESIGN Descriptive. SETTING Oncology outpatient sections of four public hospitals in Hong Kong. SAMPLE 215 ethnic Chinese women who were midway through treatment for breast cancer. METHODS Chinese versions of the Brief Fatigue Inventory, Hospital Anxiety and Depression Scale, Brief Pain Inventory, Functional Assessment of Chronic Illness Therapy for Breast Cancer, and Medical Outcomes Study Social Support Survey were used. Spearman rho correlation and structural equation modeling were used to examine the relationships among the study variables. MAIN RESEARCH VARIABLES Breast cancer, fatigue, pain, anxiety, depression, and QOL. FINDINGS Most participants reported mild-to-moderate levels of fatigue and pain. Twenty-one percent and 36% of patients might have had an anxiety or depression disorder, respectively. Significant correlations among the four symptoms supported the existence of the symptom cluster. The participants receiving chemotherapy had inadequate social support, experienced higher levels of symptoms, and were more likely to have a poorer QOL. CONCLUSIONS The findings supported the existence of the symptom cluster that had detrimental effects on QOL. IMPLICATIONS FOR NURSING This study shed light on a contemporary approach of grouping several related symptoms together. The findings enhance nurses' clinical sensitivity when identifying patients in high-risk groups and provide useful information for designing and prioritizing symptom-management strategies to meet patients' needs.
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Affiliation(s)
- Winnie K W So
- Department of Nursing Studies, University of Hong Kong, Hong Kong, SAR.
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40
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Keenen B, Qi H, Saladi SV, Yeung M, de la Serna IL. Heterogeneous SWI/SNF chromatin remodeling complexes promote expression of microphthalmia-associated transcription factor target genes in melanoma. Oncogene 2009; 29:81-92. [PMID: 19784067 PMCID: PMC2803337 DOI: 10.1038/onc.2009.304] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The microphthalmia-associated transcription factor (MITF) promotes melanocyte differentiation and cell cycle arrest. Paradoxically, MITF also promotes melanoma survival and proliferation, acting like a lineage survival oncogene. Thus, it is critically important to understand the mechanisms that regulate MITF activity in melanoma cells. SWI/SNF chromatin remodeling enzymes are multiprotein complexes composed of one of two related ATPases, BRG1 or BRM, and 9-12 associated factors (BAFs). We previously determined that BRG1 interacts with MITF to promote melanocyte differentiation. However, it was unclear whether SWI/SNF enzymes regulate the expression of different classes of MITF target genes in melanoma. In this study, we characterized SWI/SNF subunit expression in melanoma cells and observed down-regulation of BRG1 or BRM, but not concomitant loss of both ATPases. Re-introduction of BRG1 in BRG1 deficient SK-MEL5 cells enhanced expression of differentiation specific MITF target genes and resistance to cisplatin. Down-regulation of the single ATPase, BRM, in SK-MEL5 cells inhibited expression of both differentiation specific and pro-proliferative MITF target genes and inhibited tumorigenicity in vitro. Our data suggest that heterogeneous SWI/SNF complexes composed of either the BRG1 or BRM subunit promote expression of distinct and overlapping MITF target genes and that at least one ATPase is required for melanoma tumorigenicity.
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Affiliation(s)
- B Keenen
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine, Toledo, OH 43614, USA
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41
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Raj MD, Grodski S, Yeung M, Serpell J. ES04�*DIAGNOSTIC LOBECTOMY IS NOT ROUTINELY REQUIRED TO DIAGNOSE THYROID CANCER IN NODULES GREATER THAN OR EQUAL TO 4CM IN SIZE? ANZ J Surg 2009. [DOI: 10.1111/j.1445-2197.2009.04916_4.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Orsi RH, Ripoll DR, Yeung M, Nightingale KK, Wiedmann M. Recombination and positive selection contribute to evolution of Listeria monocytogenes inlA. Microbiology (Reading) 2007; 153:2666-2678. [PMID: 17660431 DOI: 10.1099/mic.0.2007/007310-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The surface molecule InlA interacts with E-cadherin to promote invasion of Listeria monocytogenes into selected host cells. DNA sequencing of inlA for 40 L. monocytogenes isolates revealed 107 synonymous and 45 nonsynonymous substitutions. A frameshift mutation in a homopolymeric tract encoding part of the InlA signal peptide was identified in three lineage II isolates, which also showed reduced ability to invade human intestinal epithelial cells. Phylogenies showed clear separation of inlA sequences into lineages I and II. Thirteen inlA recombination events, predominantly involving lineage II strains as recipients (12 events), were detected and a number of amino acid residues were shown to be under positive selection. Four of the 45 non-synonymous changes were found to be under positive selection with posterior probabilities >95 %. Mapping of polymorphic and positively selected amino acid sites on the partial crystal structure for InlA showed that the internalin surface of the leucine-rich repeat (LRR) region that faces the InlA receptor E-cadherin does not include any polymorphic sites; all polymorphic and positively selected amino acids mapped to the outer face of the LRR region or to other InlA regions. The data show that (i) inlA is highly polymorphic and evolution of inlA involved a considerable number of recombination events in lineage II isolates; (ii) positive selection at specific amino acid sites appears to contribute to evolution of inlA, including fixation of recombinant events; and (iii) single-nucleotide deletions in a lineage II-specific 3' homopolymeric tract in inlA lead to complete loss of InlA or to production of truncated InlA, which conveys reduced invasiveness. In conclusion, inlA has a complex evolutionary history, which is consistent with L. monocytogenes' natural history as an environmental pathogen with broad host-range, including its adaptation to environments and hosts where different inlA alleles may provide a selective advantage or where inlA may not be required.
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Affiliation(s)
- R H Orsi
- Department of Food Science, Cornell University, Ithaca, NY, USA
| | - D R Ripoll
- Computational Biology Service Unit, Cornell Theory Center, Cornell University, Ithaca, NY, USA
| | - M Yeung
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, USA
| | - K K Nightingale
- Department of Food Science, Cornell University, Ithaca, NY, USA
| | - M Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, USA
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Abstract
A 39-year-old HIV-infected woman developed signs and symptoms of obstructive jaundice and cholestasis. Serological tests were positive for cytomegalovirus (CMV) infection. There was no evidence of AIDS cholangiopathy in ultrasonography or magnetic resonance cholangiopancreatography (MRCP). A liver biopsy revealed marked ductopenia and the patient was diagnosed with vanishing bile duct syndrome, thought to be secondary to CMV infection as a result of profound immunosuppression. To the best of our knowledge, this is the first reported case of vanishing bile duct syndrome diagnosed in a patient with HIV/AIDS.
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Affiliation(s)
- S Hindupur
- Department of Internal Medicine, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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44
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Zabad RK, Metz LM, Todoruk TR, Zhang Y, Mitchell JR, Yeung M, Patry DG, Bell RB, Yong VW. The clinical response to minocycline in multiple sclerosis is accompanied by beneficial immune changes: a pilot study. Mult Scler 2007; 13:517-26. [PMID: 17463074 DOI: 10.1177/1352458506070319] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [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: 11/17/2022]
Abstract
Minocycline has immunomodulatory and neuroprotective activities in vitro and in an animal model of multiple sclerosis (MS). We have previously reported that minocycline decreased gadolinium-enhancing activity over six months in a small trial of patients with active relapsing-remitting MS (RRMS). Here we report the impact of oral minocycline on clinical and magnetic resonance imaging (MRI) outcomes and serum immune molecules in this cohort over 24 months of open-label minocycline treatment. Despite a moderately high pretreatment annualized relapse rate (1.3/year pre-enrolment; 1.2/year during a three-month baseline period) prior to treatment, no relapses occurred between months 6 and 24. Also, despite very active MRI activity pretreatment (19/40 scans had gadolinium-enhancing activity during a three-month run-in), the only patient with gadolinium-enhancing lesions on MRI at 12 and 24 months was on half-dose minocycline. Levels of the p40 subunit of interleukin (IL)-12, which at high levels might antagonize the proinflammatory IL-12 receptor, were elevated over 18 months of treatment, as were levels of soluble vascular cell adhesion molecule-1. The activity of matrix metalloproteinase-9 was decreased by treatment. Thus, clinical and MRI outcomes are supported by systemic immunological changes and call for further investigation of minocycline in MS.
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Affiliation(s)
- R K Zabad
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
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Nightingale KK, Windham K, Martin KE, Yeung M, Wiedmann M. Select Listeria monocytogenes subtypes commonly found in foods carry distinct nonsense mutations in inlA, leading to expression of truncated and secreted internalin A, and are associated with a reduced invasion phenotype for human intestinal epithelial cells. Appl Environ Microbiol 2006; 71:8764-72. [PMID: 16332872 PMCID: PMC1317312 DOI: 10.1128/aem.71.12.8764-8772.2005] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The surface protein internalin A (InlA) contributes to the invasion of human intestinal epithelial cells by Listeria monocytogenes. Screening of L. monocytogenes strains isolated from human clinical cases (n=46), foods (n=118), and healthy animals (n=58) in the United States revealed mutations in inlA leading to premature stop codons (PMSCs) in L. monocytogenes ribotypes DUP-1052A and DUP-16635A (PMSC mutation type 1), DUP-1025A and DUP-1031A (PMSC mutation type 2), and DUP-1046B and DUP-1062A (PMSC mutation type 3). While all DUP-1046B, DUP-1062A, DUP-16635A, and DUP-1031A isolates (n=76) contained inlA PMSCs, ribotypes DUP-1052A and DUP-1025A (n=72) contained isolates with and without inlA PMSCs. Western immunoblotting showed that all three inlA PMSCs result in the production of truncated and secreted InlA. Searches of the Pathogen Tracker database, which contains subtype and source information for more than 5,000 L. monocytogenes isolates, revealed that the six ribotypes shown to contain isolates with inlA PMSCs were overall more commonly isolated from foods than from human listeriosis cases. L. monocytogenes strains carrying inlA PMSCs also showed significantly (P=0.0004) reduced invasion of Caco-2 cells compared to isolates with homologous 3' inlA sequences without PMSCs. Invasion assays with an isogenic PMSC mutant further supported the observation that inlA PMSCs lead to reduced invasion of Caco-2 cells. Our data show that specific L. monocytogenes subtypes which are common among U.S. food isolates but rare among human listeriosis isolates carry inlA mutations that are associated with, and possibly at least partially responsible for, an attenuated invasion phenotype.
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Affiliation(s)
- K K Nightingale
- Cornell University, Department of Food Science, 412 Stocking Hall, Ithaca, NY 14853.
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Metz LM, Patten SB, Archibald CJ, Bakker JI, Harris CJ, Patry DG, Bell RB, Yeung M, Murphy WF, Stoian CA, Billesberger K, Tillotson L, Peters S, McGowan D. The effect of immunomodulatory treatment on multiple sclerosis fatigue. J Neurol Neurosurg Psychiatry 2004; 75:1045-7. [PMID: 15201369 PMCID: PMC1739126 DOI: 10.1136/jnnp.2002.007724] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To assess the effects of glatiramer acetate and beta interferon on fatigue in multiple sclerosis. METHODS Fatigue was measured at baseline and six months using the fatigue impact scale (FIS). Groups (glatiramer acetate and beta interferon) were evaluated for the proportion improved, using Fisher's exact test. Logistic regression analysis assessed the relation between treatment group and improvement and controlled for confounding variables. RESULTS Six month paired FIS assessments were available for 218 patients (76% female). Ages ranged between 19 and 61 years, with 86% having relapsing-remitting disease. Glatiramer acetate was used by 61% and beta interferon by 39%. At baseline, total FIS and subscale scores were comparable in the two groups. More patients improved on glatiramer acetate than on beta interferon on total FIS (24.8% v 12.9%, p = 0.033; adjusted odds ratio = 2.36, 95% confidence interval 1.03 to 5.42), and on physical (28.6% v 14.1%, p = 0.013) and cognitive subscales (21.1% v 10.6%, p = 0.045). Logistic regression analysis confirmed the association between glatiramer acetate use and improved fatigue, after accounting for baseline group differences. CONCLUSIONS The odds of reduced multiple sclerosis fatigue were around twice as great with glatiramer acetate treatment as with beta interferon. Confirmation of this result is required.
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Affiliation(s)
- L M Metz
- Department of Clinical Neurosciences, University of Calgary, Alberta, Canada.
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Lemke C, Yeung M, Howell PL. Expression, purification, crystallization and preliminary X-ray analysis of Escherichia coli argininosuccinate synthetase. Acta Crystallogr D Biol Crystallogr 1999; 55:2028-30. [PMID: 10666579 DOI: 10.1107/s0907444999011816] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A recombinant form of Escherichia coli argininosuccinate synthetase with a C-terminal polyhistidine affinity tag has been expressed, purified and subsequently crystallized using the hanging-drop vapour-diffusion technique. The crystals grow as large rectangular chunks with unit-cell dimensions a = 79.70, b = 105.84, c = 127.33 A, alpha = beta = gamma = 90 degrees. The crystals exhibit the symmetry of space group I222 and diffract to a minimum d-spacing of 1.6 A at station X8C of the National Synchrotron Light Source, Brookhaven National Laboratory. On the basis of density calculations, one monomer of this homotetrameric protein is predicted per asymmetric unit (Matthews coefficient V(m) = 2.69 A(3) Da(-1)).
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Affiliation(s)
- C Lemke
- Structural Biology and Biochemistry, Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, M5G 1X8, Ontario, Canada
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Yeung M, Downe L, Coughtrey H. Gentamicin doses and dose intervals in neonatal intensive care. J Paediatr Child Health 1999; 35:411-2. [PMID: 10457306] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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Abstract
OBJECTIVES To identify the clinical, electrophysiological, and genetic characteristics of a family with an unusual form of hereditary motor neuron disease. METHODS Surviving members of a pedigree in which affected members presented with weakness and atrophy of distal musculature in the upper limbs were examined clinically and electrophysiologically, and had genetic testing. RESULTS The disease was autosomal dominantly inherited and manifested as weakness and atrophy of distal musculature in the upper limbs, with minimal involvement of lower limbs, brisk reflexes, minimal sensory findings, and considerable variability in severity among the affected persons. Nerve conduction studies disclosed near normal motor conduction velocity, reduced motor compound action potential amplitude, prolonged distal motor latency, prolonged sensory latency, and normal sensory compound action potential amplitude. Needle electrode examination showed reduced number and increased size of motor unit potentials, but no fibrillations or fasciculations. CONCLUSION Distal upper limb muscular atrophy is a distinct clinical entity.
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Affiliation(s)
- D W Gross
- University of Saskatchewan, Saskatoon, Canada
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Kerbel D, Glazier R, Holzapfel S, Yeung M, Lofsky S. Adverse effects of screening for gestational diabetes: a prospective cohort study in Toronto, Canada. J Med Screen 1997; 4:128-32. [PMID: 9368868 DOI: 10.1177/096914139700400303] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To investigate the adverse effects associated with a false positive 50 g glucose challenge test for gestational diabetes mellitus (GDM). SETTING Consecutive women attending a prenatal registration clinic at a large community hospital in suburban Toronto, Canada. METHODS Prospective cohort study of women between 12 and 24 weeks' gestation with no previous history of diabetes mellitus or GDM. Main outcome measures included anxiety (Spielberger's State-Trait Anxiety Inventory), depression (Centers for Epidemiologic Studies Depression Scale), perceived maternal health, and concern about health of the newborn. RESULTS Among 2564 eligible subjects, there were 897 subjects with complete data at enrollment and at 32 weeks' gestation, including 88 who had false positive glucose challenge test results. At 32 weeks, only 20% (95% confidence limits 11%, 28%) of women with false positive glucose challenge test results rated their health as excellent, compared with 38% (35%, 42%) of those having negative results and those not tested (P = 0.001). These results were sustained at 36 weeks. There was no association between glucose challenge test result and the change in anxiety (P = 0.57), depression (P = 0.09) or concern about health of the newborn (P = 0.91) between baseline and 32 weeks' gestation, nor were these associations found at 36 weeks. CONCLUSIONS False positive glucose challenge test results are about six times more likely than true positive results in the general population. Pregnant women with false positive GDM screening results experience a significant decline in their perception of their own health. These adverse effects should be taken into account when deciding about a policy of screening all pregnant women for gestational diabetes.
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Affiliation(s)
- D Kerbel
- Public Health Branch, Ontario Ministry of Health, Canada
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