1
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Tran P, Lau C, Joshi M, Kuehl M, Maddock H, Banerjee P. Exploring Changes in Myocyte Structure, Contractility, and Energetics From Mechanical Unloading in Patients With Heart Failure Undergoing Ventricular Assist Device Implantation: A Systematic Review and Meta-Analysis. Heart Lung Circ 2024:S1443-9506(24)00082-9. [PMID: 38704332 DOI: 10.1016/j.hlc.2024.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 01/27/2024] [Accepted: 01/31/2024] [Indexed: 05/06/2024]
Abstract
AIMS Recent reports of myocardial recovery after mechanical unloading with left ventricular assist devices (LVADs) have challenged the prevailing notion that end-stage heart failure (HF) is irreversible. To improve our understanding of this phenomenon, we comprehensively analysed the structural, functional, and energetic changes in failing human cardiomyocytes after LVAD implantation. METHODS Based on a prospectively registered protocol (PROSPERO-CRD42022380214), 30 eligible studies were identified from 940 records with a pooled population of 648 patients predominantly with non-ischaemic cardiomyopathy. RESULTS LVAD led to a substantial regression in myocyte size similar to that of donor hearts (standardised mean difference, -1.29; p<0.001). The meta-regression analysis revealed that HF duration was a significant modifier on the changes in myocyte size. There were some suggestions of fibrosis reversal (-5.17%; p=0.009); however, this was insignificant after sensitivity analysis. Developed force did not improve in cardiac trabeculae (n=5 studies); however, non-physiological isometric contractions were tested. At the myocyte level (n=4 studies), contractile kinetics improved where the time-to-peak force reduced by 41.7%-50.7% and time to 50% relaxation fell by 47.4%-62.1% (p<0.05). Qualitatively, LVAD enhanced substrate utilisation and mitochondrial function (n=6 studies). Most studies were at a high risk of bias. CONCLUSION The regression of maladaptive hypertrophy, partial fibrosis reversal, and normalisation in metabolic pathways after LVAD may be a testament to the heart's remarkable plasticity, even in the advanced stages of HF. However, inconsistencies exist in force-generating capabilities. Using more physiological force-length work-loop assays, addressing the high risks of bias and clinical heterogeneity are crucial to better understand the phenomenon of reverse remodelling.
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Affiliation(s)
- Patrick Tran
- Centre for Health & Life Sciences, Coventry University, Coventry, UK; Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK.
| | - Clement Lau
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
| | - Mithilesh Joshi
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
| | - Michael Kuehl
- Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
| | - Helen Maddock
- Centre for Health & Life Sciences, Coventry University, Coventry, UK
| | - Prithwish Banerjee
- Centre for Health & Life Sciences, Coventry University, Coventry, UK; Cardiology Department, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK; Warwick Medical School, University of Warwick, Coventry, UK
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Shabbir A, Chhetri I, Khambata RS, Parakaw T, Lau C, Aubdool MABN, Massimo G, Dyson N, Kapil V, Godec T, Apea V, Flint J, Orkin C, Rathod KS, Ahluwalia A. A double-blind, randomised, placebo-controlled parallel study to investigate the effect of sex and dietary nitrate on COVID-19 vaccine-induced vascular dysfunction in healthy men and women: protocol of the DiNOVasc-COVID-19 study. Trials 2023; 24:593. [PMID: 37715222 PMCID: PMC10504715 DOI: 10.1186/s13063-023-07616-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/30/2023] [Indexed: 09/17/2023] Open
Abstract
BACKGROUND Cardiovascular events, driven by endothelial dysfunction, are a recognised complication of COVID-19. SARS-CoV-2 infections remain a persistent concern globally, and an understanding of the mechanisms causing endothelial dysfunction, particularly the role of inflammation, nitric oxide, and whether sex differences exist in this response, is lacking. We have previously demonstrated important sex differences in the inflammatory response and its impact on endothelial function and separately that the ingestion of inorganic nitrate can protect the endothelium against this dysfunction. In this study, we will investigate whether sex or a dietary inorganic nitrate intervention modulates endothelial function and inflammatory responses after the COVID-19 vaccine. METHODS DiNOVasc-COVID-19 is a double-blind, randomised, single-centre, placebo-controlled clinical trial. A total of 98 healthy volunteers (49 males and 49 females) will be recruited. Participants will be randomised into 1 of 2 sub-studies: part A or part B. Part A will investigate the effects of sex on vascular and inflammatory responses to the COVID-19 vaccine. Part B will investigate the effects of sex and dietary inorganic nitrate on vascular and inflammatory responses to the COVID-19 vaccine. In part B, participants will be randomised to receive 3 days of either nitrate-containing beetroot juice (intervention) or nitrate-deplete beetroot juice (placebo). The primary outcome for both sub-studies is a comparison of the change in flow-mediated dilatation (FMD) from baseline after COVID-19 vaccination. The study has a power of > 80% to assess the primary endpoint. Secondary endpoints include change from baseline in inflammatory and leukocyte counts and in pulse wave analysis (PWA) and pulse wave velocity (PWV) following the COVID-19 vaccination. DISCUSSION This study aims to evaluate whether sex or dietary influences endothelial function and inflammatory responses in healthy volunteers after receiving the COVID-19 vaccine. TRIAL REGISTRATION ClinicalTrials.gov NCT04889274. Registered on 5 May 2023. The study was approved by the South Central - Oxford C Research Ethics Committee (21/SC/0154).
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Affiliation(s)
- Asad Shabbir
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- Department of Cardiology, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Ismita Chhetri
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Rayomand S Khambata
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Tipparat Parakaw
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Clement Lau
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- Department of Cardiology, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Muhammad A B N Aubdool
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Gianmichele Massimo
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Nicki Dyson
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Vikas Kapil
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Thomas Godec
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Vanessa Apea
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
| | - Jan Flint
- Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - Chloe Orkin
- Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - Krishnaraj S Rathod
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK
- Department of Cardiology, Barts Heart Centre, St. Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Amrita Ahluwalia
- Barts and The London Faculty of Medicine and Dentistry, Queen Mary University of London, London, EC1M 6BQ, UK.
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Chowdhury S, Crocker NA, Peebles WA, Rhodes TL, Zeng L, Lantsov R, Van Compernolle B, Brookman M, Pinsker RI, Lau C. A novel Doppler backscattering (DBS) system to simultaneously measure radio frequency plasma fluctuations and low frequency turbulence. Rev Sci Instrum 2023; 94:073504. [PMID: 37493501 DOI: 10.1063/5.0149654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023]
Abstract
A novel quadrature Doppler Backscattering (DBS) system has been developed and optimized for the E-band (60-90 GHz) frequency range using either O-mode or X-mode polarization in DIII-D plasmas. In general, DBS measures the amplitude of density fluctuations and their velocity in the lab frame. The system can simultaneously monitor both low-frequency turbulence (f < 10 MHz) and radiofrequency plasma density fluctuations over a selectable frequency range (20-500 MHz). Detection of high-frequency fluctuations has been demonstrated for low harmonics of the ion cyclotron frequency (e.g., 2fci ∼ 23 MHz) and externally driven high-frequency helicon waves (f = 476 MHz) using an adjustable frequency down conversion system. Importantly, this extends the application of DBS to a high-frequency spectral domain while maintaining important turbulence and flow measurement capabilities. This unique system has low phase noise, good temporal resolution (sub-millisecond), and excellent wavenumber coverage (kθ ∼ 1-20 cm-1 and kr ≲ 30 cm-1). As a demonstration, localized internal DIII-D plasma measurements are presented from turbulence (f ≤ 5 MHz), Alfvenic waves (f ∼ 6.5 MHz), ion cyclotron waves (f ≥ 20 MHz), as well as fluctuations around 476 MHz driven by an external high-power 476 MHz helicon wave antenna. In the future, helicon measurements will be used to validate GENRAY and AORSA modeling tools for prediction of helicon wave propagation, absorption, and current drive location for the newly installed helicon current drive system on DIII-D.
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Affiliation(s)
- S Chowdhury
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - N A Crocker
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - W A Peebles
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - T L Rhodes
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - L Zeng
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - R Lantsov
- Physics and Astronomy Department, University of California Los Angeles, Los Angeles, California 90098, USA
| | - B Van Compernolle
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - M Brookman
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - R I Pinsker
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
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Leppink E, Lau C, Lin Y, Wukitch SJ. Evaluation of the Abel inversion integral in O-mode plasma reflectometry using Chebyshev-Gauss quadrature. Rev Sci Instrum 2023; 94:063506. [PMID: 37862546 DOI: 10.1063/5.0132246] [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: 10/27/2022] [Accepted: 06/15/2023] [Indexed: 10/22/2023]
Abstract
The Abel transform is often used to reconstruct plasma density profiles from O-Mode polarized reflectometry diagnostics. However, standard numerical trapezoidal evaluation of the Abel inversion integral can be computationally expensive for a large number of evaluation points, and an endpoint singularity exists on the upper-bound of the integral, which can result in an increased error. In this work, Chebyshev-Gauss quadrature is introduced as a new method to evaluate the Abel inversion integral for the problem of O-Mode plasma reflectometry. The method does not require numerical evaluation of an integral singularity and is shown to have similar accuracy compared to existing methods while being computationally efficient.
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Affiliation(s)
- E Leppink
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Y Lin
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
| | - S J Wukitch
- MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA
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Lau C, Gul U, Liu B, Captur G, Hothi SS. Cardiovascular Magnetic Resonance Imaging in Familial Dilated Cardiomyopathy. Medicina (B Aires) 2023; 59:medicina59030439. [PMID: 36984439 PMCID: PMC10057087 DOI: 10.3390/medicina59030439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/25/2023] Open
Abstract
Dilated cardiomyopathy (DCM) is a common cause of non-ischaemic heart failure, conferring high morbidity and mortality, including sudden cardiac death due to systolic dysfunction or arrhythmic sudden death. Within the DCM cohort exists a group of patients with familial disease. In this article we review the pathophysiology and cardiac imaging findings of familial DCM, with specific attention to known disease subtypes. The role of advanced cardiac imaging cardiovascular magnetic resonance is still accumulating, and there remains much to be elucidated. We discuss its potential clinical roles as currently known, with respect to diagnostic utility and risk stratification. Advances in such risk stratification may help target pharmacological and device therapies to those at highest risk.
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Affiliation(s)
- Clement Lau
- New Cross Hospital, Royal Wolverhampton NHS Trust, Wolverhampton WV10 0QP, UK
| | - Uzma Gul
- New Cross Hospital, Royal Wolverhampton NHS Trust, Wolverhampton WV10 0QP, UK
| | - Boyang Liu
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Gabriella Captur
- MRC Unit for Lifelong Health and Ageing at UCL, University College London, London WC1E 6BT, UK
- Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK
- Centre for Inherited Heart Muscle Conditions, Cardiology Department, The Royal Free Hospital, London NW3 2QG, UK
| | - Sandeep S. Hothi
- New Cross Hospital, Royal Wolverhampton NHS Trust, Wolverhampton WV10 0QP, UK
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Correspondence:
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Cerrato C, Margaret M, Autorino R, Simone G, Yang B, Uzzo R, Kutikov A, Porpiglia F, Capitanio U, Montorsi F, Porter J, Beksac A, Nguyen M, Hakimi K, Pandolfo S, Minervini A, Lau C, Monish A, Eun D, Mottrie A, Mir C, Sundaram C, Antonelli A, Kaouk J, Derweesh I. Partial versus radical nephrectomy for complex renal mass: Multicenter comparative analysis of functional outcomes (ROSULA Collaborative Group). Eur Urol 2023. [DOI: 10.1016/s0302-2838(23)01057-6] [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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Cerrato C, Autorino R, Simone G, Yang B, Uzzo R, Porpiglia F, Capitanio U, Montorsi F, Porter J, Beksac A, Minervini A, Lau C, Akbar A, Eun D, Mottrie A, Mir C, Meagher M, Nguyen M, Pandolfo S, Kutikov A, Cerruto M, Antonelli A, Sundaram C, Kaouk J, Derweesh I. Partial or radical nephrectomy for complex renal mass: A comparative analysis of oncological outcomes and complications from the rosula (robotic surgery for large renal mass) collaborative group. Eur Urol 2023. [DOI: 10.1016/s0302-2838(23)00891-6] [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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Zhang Y, Lau C, Gabriel B, Ifeoluwa J, Yap T. Venous thromboembolism risk in testosterone treated men with and without Klinefelter syndrome. Eur Urol 2023. [DOI: 10.1016/s0302-2838(23)00270-1] [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] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Lau C, Elshibly MMM, Kanagala P, Khoo JP, Arnold JR, Hothi SS. The role of cardiac magnetic resonance imaging in the assessment of heart failure with preserved ejection fraction. Front Cardiovasc Med 2022; 9:922398. [PMID: 35924215 PMCID: PMC9339656 DOI: 10.3389/fcvm.2022.922398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
Heart failure (HF) is a major cause of morbidity and mortality worldwide. Current classifications of HF categorize patients with a left ventricular ejection fraction of 50% or greater as HF with preserved ejection fraction or HFpEF. Echocardiography is the first line imaging modality in assessing diastolic function given its practicality, low cost and the utilization of Doppler imaging. However, the last decade has seen cardiac magnetic resonance (CMR) emerge as a valuable test for the sometimes challenging diagnosis of HFpEF. The unique ability of CMR for myocardial tissue characterization coupled with high resolution imaging provides additional information to echocardiography that may help in phenotyping HFpEF and provide prognostication for patients with HF. The precision and accuracy of CMR underlies its use in clinical trials for the assessment of novel and repurposed drugs in HFpEF. Importantly, CMR has powerful diagnostic utility in differentiating acquired and inherited heart muscle diseases presenting as HFpEF such as Fabry disease and amyloidosis with specific treatment options to reverse or halt disease progression. This state of the art review will outline established CMR techniques such as transmitral velocities and strain imaging of the left ventricle and left atrium in assessing diastolic function and their clinical application to HFpEF. Furthermore, it will include a discussion on novel methods and future developments such as stress CMR and MR spectroscopy to assess myocardial energetics, which show promise in unraveling the mechanisms behind HFpEF that may provide targets for much needed therapeutic interventions.
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Affiliation(s)
- Clement Lau
- Department of Cardiology, New Cross Hospital, Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom
| | - Mohamed M. M. Elshibly
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Prathap Kanagala
- Department of Cardiology, Liverpool University Hospitals NHS Foundation Trust and Liverpool Centre for Cardiovascular Science, Liverpool, United Kingdom
| | - Jeffrey P. Khoo
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Jayanth Ranjit Arnold
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Sandeep Singh Hothi
- Department of Cardiology, New Cross Hospital, Royal Wolverhampton NHS Trust, Wolverhampton, United Kingdom
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
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Pasrija C, Shah A, Holmes S, Bittle G, Reed R, Patel V, Lau C, Krupnick A. Safety of Single Lung Transplantation Post Donation Service Area-Specific Organ Distribution. J Heart Lung Transplant 2022. [DOI: 10.1016/j.healun.2022.01.1226] [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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Davies RH, Augusto JB, Bhuva A, Xue H, Treibel TA, Ye Y, Hughes RK, Bai W, Lau C, Shiwani H, Fontana M, Kozor R, Herrey A, Lopes LR, Maestrini V, Rosmini S, Petersen SE, Kellman P, Rueckert D, Greenwood JP, Captur G, Manisty C, Schelbert E, Moon JC. Precision measurement of cardiac structure and function in cardiovascular magnetic resonance using machine learning. J Cardiovasc Magn Reson 2022; 24:16. [PMID: 35272664 PMCID: PMC8908603 DOI: 10.1186/s12968-022-00846-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/03/2022] [Indexed: 02/21/2023] Open
Abstract
BACKGROUND Measurement of cardiac structure and function from images (e.g. volumes, mass and derived parameters such as left ventricular (LV) ejection fraction [LVEF]) guides care for millions. This is best assessed using cardiovascular magnetic resonance (CMR), but image analysis is currently performed by individual clinicians, which introduces error. We sought to develop a machine learning algorithm for volumetric analysis of CMR images with demonstrably better precision than human analysis. METHODS A fully automated machine learning algorithm was trained on 1923 scans (10 scanner models, 13 institutions, 9 clinical conditions, 60,000 contours) and used to segment the LV blood volume and myocardium. Performance was quantified by measuring precision on an independent multi-site validation dataset with multiple pathologies with n = 109 patients, scanned twice. This dataset was augmented with a further 1277 patients scanned as part of routine clinical care to allow qualitative assessment of generalization ability by identifying mis-segmentations. Machine learning algorithm ('machine') performance was compared to three clinicians ('human') and a commercial tool (cvi42, Circle Cardiovascular Imaging). FINDINGS Machine analysis was quicker (20 s per patient) than human (13 min). Overall machine mis-segmentation rate was 1 in 479 images for the combined dataset, occurring mostly in rare pathologies not encountered in training. Without correcting these mis-segmentations, machine analysis had superior precision to three clinicians (e.g. scan-rescan coefficients of variation of human vs machine: LVEF 6.0% vs 4.2%, LV mass 4.8% vs. 3.6%; both P < 0.05), translating to a 46% reduction in required trial sample size using an LVEF endpoint. CONCLUSION We present a fully automated algorithm for measuring LV structure and global systolic function that betters human performance for speed and precision.
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Affiliation(s)
- Rhodri H Davies
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - João B Augusto
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Anish Bhuva
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Hui Xue
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, USA
| | - Thomas A Treibel
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Yang Ye
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Rebecca K Hughes
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Wenjia Bai
- Data Science Institute, Imperial College London, London, UK
| | - Clement Lau
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
- William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Hunain Shiwani
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Marianna Fontana
- Institute of Cardiovascular Science, University College London, London, UK
- National Amyloidosis Centre, University College London, London, UK
| | - Rebecca Kozor
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Anna Herrey
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Luis R Lopes
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Viviana Maestrini
- Department of Clinical, Internal, Anesthesiology and Cardiovascular Sciences, Sapienza University of Rome, Rome, Italy
| | - Stefania Rosmini
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Steffen E Petersen
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
- William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, USA
| | - Daniel Rueckert
- Biomedical Image Analysis Group, Department of Computing, Imperial College London, London, UK
| | - John P Greenwood
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Gabriella Captur
- Institute of Cardiovascular Science, University College London, London, UK
- MRC Unit for Lifelong Health and Ageing, University College London, London, UK
| | - Charlotte Manisty
- Institute of Cardiovascular Science, University College London, London, UK
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK
| | - Erik Schelbert
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, USA
- Minneapolis Heart Institute East, Saint Paul, MN, USA
| | - James C Moon
- Institute of Cardiovascular Science, University College London, London, UK.
- Bart's Heart Centre, St Bartholomew's Hospital, West Smithfield, London, EC1A 7BE, UK.
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Tuderti G, Autorino R, Minervini A, Kaouk J, Lau C, Perdonà S, Porpiglia F, Derweesh I, Saidian A, Nguyen M, Carbonara U, Rha K, Schiavina R, Mastroianni R, Misuraca L, Mari A, Brassetti A, Anceschi U, Bove A, Ferriero M, Mottrie A, Gallucci M, Simone G. On-clamp versus off-clamp robotic partial nephrectomy for totally endophytic deep renal masses: Propensity score-matched comparison of perioperative, oncologic and functional outcomes of a multicenter analysis (ROSULA database). Eur Urol 2022. [DOI: 10.1016/s0302-2838(22)00420-1] [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] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tuderti G, Autorino R, Mastroianni R, Mari A, Carbonara U, Misuraca L, Anceschi U, Brassetti A, Ferriero M, Bove A, Costantini M, Porpiglia F, Kaouk J, Lau C, Derweesh I, Rha K, Schiavina R, Mottrie A, Gallucci M, Simone G. Nephrometry scores predicting value of Trifecta achievement in a multicenter analysis (ROSULA database) of Robotic Partial Nephrectomy for totally endophytic “deep” renal masses. Eur Urol 2022. [DOI: 10.1016/s0302-2838(22)00146-4] [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: 11/29/2022]
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Joy G, Artico J, Kurdi H, Seraphim A, Lau C, Thornton GD, Oliveira MF, Adam RD, Aziminia N, Menacho K, Chacko L, Brown JT, Patel RK, Shiwani H, Bhuva A, Augusto JB, Andiapen M, McKnight A, Noursadeghi M, Pierce I, Evain T, Captur G, Davies RH, Greenwood JP, Fontana M, Kellman P, Schelbert EB, Treibel TA, Manisty C, Moon JC. Prospective Case-Control Study of Cardiovascular Abnormalities 6 Months Following Mild COVID-19 in Healthcare Workers. JACC Cardiovasc Imaging 2021; 14:2155-2166. [PMID: 33975819 PMCID: PMC8105493 DOI: 10.1016/j.jcmg.2021.04.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/08/2021] [Accepted: 04/08/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The purpose of this study was to detect cardiovascular changes after mild severe acute respiratory syndrome-coronavirus-2 infection. BACKGROUND Concern exists that mild coronavirus disease 2019 may cause myocardial and vascular disease. METHODS Participants were recruited from COVIDsortium, a 3-hospital prospective study of 731 health care workers who underwent first-wave weekly symptom, polymerase chain reaction, and serology assessment over 4 months, with seroconversion in 21.5% (n = 157). At 6 months post-infection, 74 seropositive and 75 age-, sex-, and ethnicity-matched seronegative control subjects were recruited for cardiovascular phenotyping (comprehensive phantom-calibrated cardiovascular magnetic resonance and blood biomarkers). Analysis was blinded, using objective artificial intelligence analytics where available. RESULTS A total of 149 subjects (mean age 37 years, range 18 to 63 years, 58% women) were recruited. Seropositive infections had been mild with case definition, noncase definition, and asymptomatic disease in 45 (61%), 18 (24%), and 11 (15%), respectively, with 1 person hospitalized (for 2 days). Between seropositive and seronegative groups, there were no differences in cardiac structure (left ventricular volumes, mass, atrial area), function (ejection fraction, global longitudinal shortening, aortic distensibility), tissue characterization (T1, T2, extracellular volume fraction mapping, late gadolinium enhancement) or biomarkers (troponin, N-terminal pro-B-type natriuretic peptide). With abnormal defined by the 75 seronegatives (2 SDs from mean, e.g., ejection fraction <54%, septal T1 >1,072 ms, septal T2 >52.4 ms), individuals had abnormalities including reduced ejection fraction (n = 2, minimum 50%), T1 elevation (n = 6), T2 elevation (n = 9), late gadolinium enhancement (n = 13, median 1%, max 5% of myocardium), biomarker elevation (borderline troponin elevation in 4; all N-terminal pro-B-type natriuretic peptide normal). These were distributed equally between seropositive and seronegative individuals. CONCLUSIONS Cardiovascular abnormalities are no more common in seropositive versus seronegative otherwise healthy, workforce representative individuals 6 months post-mild severe acute respiratory syndrome-coronavirus-2 infection.
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Affiliation(s)
- George Joy
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Jessica Artico
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Hibba Kurdi
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Andreas Seraphim
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Clement Lau
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - George D Thornton
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Marta Fontes Oliveira
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Cardiology Department, University Hospital Centre of Porto, Porto, Portugal
| | - Robert Daniel Adam
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Nikoo Aziminia
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom
| | - Katia Menacho
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Liza Chacko
- Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, Division of Medicine, University College London, London, United Kingdom; Royal Free London NHS Foundation Trust, Pond Street, London, United Kingdom
| | - James T Brown
- Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, Division of Medicine, University College London, London, United Kingdom; Royal Free London NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Rishi K Patel
- Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, Division of Medicine, University College London, London, United Kingdom; Royal Free London NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Hunain Shiwani
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Anish Bhuva
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Joao B Augusto
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom; Cardiology Department, Hospital Prof Doutor Fernando Fonseca Amadora, Portugal
| | - Mervyn Andiapen
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Aine McKnight
- Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Mahdad Noursadeghi
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Iain Pierce
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | | | - Gabriella Captur
- Institute of Cardiovascular Science, University College London, London, United Kingdom; Royal Free London NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Rhodri H Davies
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - John P Greenwood
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, and Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom
| | - Marianna Fontana
- Institute of Cardiovascular Science, University College London, London, United Kingdom; National Amyloidosis Centre, Division of Medicine, University College London, London, United Kingdom; Royal Free London NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, Maryland, USA
| | | | - Thomas A Treibel
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - Charlotte Manisty
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom
| | - James C Moon
- Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom; Institute of Cardiovascular Science, University College London, London, United Kingdom.
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15
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Lau C, Shabbir A, Rathod KS, Chhetri I, Ono M, Hamers AJP, Amarin JJ, Ibrahim A, Nuredini G, Godec T, Kapil V, Ahluwalia A. Inorganic nitrate attenuates endothelial dysfunction consequent to systemic inflammation. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3008] [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: 11/14/2022] Open
Abstract
Abstract
Introduction
Chronic cardiovascular diseases are characterised by low-grade systemic inflammation and attenuated nitric oxide (NO) bioavailability resulting in endothelial dysfunction. Inorganic nitrate augments NO bioavailability and improves markers of vascular dysfunction in patients with cardiovascular risk factors. However, the exact mechanism of this effect is uncertain.
Purpose
To determine whether inorganic nitrate supplementation alters systemic inflammation-induced endothelial dysfunction.
Methods
62 healthy male volunteers were randomised 1:1 to receive ∼8–10 mmol of dietary inorganic nitrate in beetroot juice or nitrate-free beetroot juice (placebo) once daily for 6 days. Measures of brachial artery flow-mediated dilatation (FMD), brachial blood pressure (BP), pulse wave analysis and carotid-femoral pulse wave velocity (PWV) by Vicorder were taken prior to and at 8 hours after a typhoid vaccine (to induce mild systemic inflammation). Plasma, urine and saliva samples were also collected. Clinicaltrials.gov: NCT02715635.
Results
Baseline characteristics were similar between the two groups. Inorganic nitrate significantly elevated plasma nitrite (placebo = Δ0.02±0.5 μM, inorganic nitrate = Δ0.63±1.2 μM; p=0.01) and nitrate levels (p<0.0001) compared to placebo. There were significant increases in urine nitrite (p<0.0001) and nitrate (p<0.0001) in addition to salivary nitrite (p<0.0001) and nitrate (p<0.0001) compared to placebo. After 8 hours, typhoid vaccine induced an increase in circulating white cells (placebo = Δ3.34±3.37x109/L, inorganic nitrate = Δ2.9±2.78x109/L; p=0.58) that was similar in in both arms. However, there was a significant reduction in the FMD response in the placebo group at 8-hours post vaccine; an effect that was absent in volunteers treated with inorganic nitrate (placebo = Δ−1.33±1.53%, inorganic nitrate = Δ−0.07±1.84%, p=0.005). Importantly, there were no statistically significant differences in baseline vessel diameter (p=0.78), time to peak diameter in response to flow (p=0.87) and peak shear rate (p=0.57) between the groups. When comparing change from baseline to 8 hours after the vaccine, there were no significant differences in brachial systolic BP (p=0.12), central systolic BP (p=0.12) and PWV (p=0.60) between groups, but a significant reduction in brachial diastolic BP in the inorganic nitrate group (p=0.048).
Conclusions
Inflammation-induced endothelial dysfunction was prevented in those receiving dietary inorganic nitrate suggesting that elevating circulating nitrite and delivering NO to the blood vessel wall, through dietary approaches may offer potential therapeutic benefit in those cardiovascular diseases which typically exhibit low grade inflammation and deficiencies in bioavailable NO.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): British Heart Foundation
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Affiliation(s)
- C Lau
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - A Shabbir
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - K S Rathod
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - I Chhetri
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - M Ono
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - A J P Hamers
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - J J Amarin
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - A Ibrahim
- University of Southampton, Southampton, United Kingdom
| | - G Nuredini
- Barts Health NHS Trust, London, United Kingdom
| | - T Godec
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - V Kapil
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - A Ahluwalia
- William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
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16
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Shabbir A, Lau C, Rathod KS, Chhetri I, Haque A, Godec T, Khambata RS, Kapil V, Ahluwalia A. Inorganic nitrate attenuates the systemic inflammatory response in typhoid vaccine-induced endothelial dysfunction in healthy volunteers. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3009] [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
Inflammatory responses underlie the development of endothelial dysfunction in CVD, however, therapeutics that might target this pathway have not been forthcoming. A key pathogenic mechanism mediating endothelial dysfunction is a reduction in bioavailable (eNOS-derived) nitric oxide (NO). Activation of the non-canonical pathway for in-vivo NO generation might offer an approach to improve NO levels and recover vascular function in pre-clinical models of CVD. Whether this might occur in humans is unknown.
Purpose
We hypothesize that consumption of inorganic nitrate will lead to increases in bioavailable NO and thus attenuate the inflammatory pathways leading to typhoid vaccine-induced endothelial dysfunction in healthy volunteers.
Methods
Healthy male volunteers were recruited (n=78) and randomized to receive either beetroot juice containing 8–10mmol nitrate or placebo (nitrate-deplete) juice once daily for 6 days. Participants underwent serial measurements of BP, FMD and GTN-induced brachial artery dilatation, and haematology and biochemistry, before and after typhoid vaccination. Blood, urine and saliva nitrite and nitrate were quantified using ozone chemiluminescence, and leukocyte flow cytometry analysis was conducted.
Results
8-hours post-vaccine endothelial function was depressed in placebo-treated volunteers, however this was prevented in nitrate-treated volunteers. This dysfunction was due to impaired endothelial function since responses to GTN were unaffected either by vaccination or dietary intervention (p=0.981). Dietary nitrate resulted in an increase in plasma (p<0.0001), urine (p=0.0006) and saliva (p<0.0001) nitrate, and urine (p=0.0354) and saliva (p<0.0001) nitrite levels. There was a reduction in the proportions of CD14++/CD16+intermediate monocytes in nitrate-treated participants after vaccine (p=0.016, change from baseline between groups). In the nitrate-treated group, less CD14++/CD16+ intermediate monocyte CD62L expression was identified post-vaccine (p=0.0122), compared to placebo, with no difference in soluble plasma CD62L between groups (p=0.875). CD11b median fluorescence intensity was increased in CD3+/CD4+ T-lymphocytes in nitrate-treated volunteers (p=0.0095).
Conclusions
Dietary nitrate reduced BP, as previously shown, indicating efficacy of the intervention. Importantly, we also now show for the first time that inorganic nitrate suppresses the systemic inflammatory response, specifically by reducing the numbers and activation state of CD14++/CD16+ intermediate monocytes. Furthermore, an increased expression of CD3+/CD4+ T-cell CD11b and preserved FMD in healthy volunteers treated with nitrate, suggests an anti-inflammatory phenotype, induced by the intervention, leading to improved endothelial function. Inorganic dietary nitrate modulates endothelial function through the attenuation of inflammatory responses and may be of potential therapeutic benefit in patients with established CAD.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- A Shabbir
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - C Lau
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - K S Rathod
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - I Chhetri
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - A Haque
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - T Godec
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - R S Khambata
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - V Kapil
- St Bartholomews and Queen Mary University, London, United Kingdom
| | - A Ahluwalia
- St Bartholomews and Queen Mary University, London, United Kingdom
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17
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Misuraca L, Tuderti G, Autorino R, Carbonara U, Mari A, Amparore D, Mastroianni R, Bove A, Anceschi U, Ferriero M, Brassetti A, Perdonà S, Lau C, Koon H, Leonardo C, Schiavina R, Derweesh I, Porpiglia F, Mottrie A, Kaouk J, Minervini A, Simone G. Nephrometry scores predicting value of trifecta achievement in a multicenter analysis (ROSULA database) of robotic partial nephrectomy for totally endophytic “deep” renal masses. EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00734-5] [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: 10/20/2022] Open
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18
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Tuderti G, Autorino R, Carbonara U, Mari A, Amparore D, Mastroianni R, Bove A, Anceschi U, Perdonà S, Lau C, Koon H, Leonardo C, Misuraca L, Ferriero M, Brassetti A, Schiavina R, Derweesh I, Porpiglia F, Mottrie A, Kaouk J, Minervini A, Simone G. Renal function deterioration assessment in totally endophytic “deep” renal masses treated with robotic partial nephrectomy: comparison with a whole cohort of cT1-2 renal tumors patients from a multicenter analysis (ROSULA database). EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00753-9] [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: 10/20/2022] Open
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19
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Misuraca L, Tuderti G, Autorino R, Carbonara U, Mari A, Amparore D, Mastroianni R, Bove A, Anceschi U, Ferriero M, Brassetti A, Perdonà S, Lau C, Koon H, Leonardo C, Schiavina R, Derweesh I, Porpiglia F, Mottrie A, Kaouk J, Minervini A, Simone G. Robotic partial nephrectomy for totally endophytic “deep” renal masses: perioperative, pathologic, oncologic and functional outcomes of a multicenter analysis (ROSULA database). EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00755-2] [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: 10/20/2022] Open
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20
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Tuderti G, Autorino R, Carbonara U, Mari A, Amparore D, Mastroianni R, Bove A, Anceschi U, Misuraca L, Ferriero M, Brassetti A, Perdonà S, Lau C, Koon H, Leonardo C, Schiavina R, Derweesh I, Porpiglia F, Mottrie A, Kaouk J, Minervini A, Simone G. Trifecta assessment in totally endophytic “deep” renal masses treated with robotic partial nephrectomy: comparison with a whole cohort of cT1-2 renal tumors patients from a multicenter analysis (ROSULA database). EUR UROL SUPPL 2021. [DOI: 10.1016/s2666-1683(21)00754-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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21
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Lim AJ, Lau C, Li NP. The Moderating Role of Social Network Size on Social Media Use and Self-Esteem: An Evolutionary Mismatch Perspective. Front Psychol 2021; 12:734206. [PMID: 34646214 PMCID: PMC8503551 DOI: 10.3389/fpsyg.2021.734206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/02/2021] [Indexed: 11/24/2022] Open
Abstract
Existing meta-analyses have shown that the relationship between social media use and self-esteem is negative, but at very small effect sizes, suggesting the presence of moderators that change the relationship between social media use and self-esteem. Employing principles from social comparison and evolutionary mismatch theories, we propose that the social network sizes one has on social media play a key role in the relationship between social media use and self-esteem. In our study (N = 123), we showed that social media use was negatively related to self-esteem, but only when their social network size was within an evolutionarily familiar level. Social media use was not related to self-esteem when people's social networks were at evolutionarily novel sizes. The data supported both social comparison and evolutionary mismatch theories and elucidated the small effect size found for the relationship between social media use and self-esteem in current literature. More critically, the findings of this study highlight the need to consider evolutionarily novel stimuli that are present on social media to better understand the behaviors of people in this social environment.
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Affiliation(s)
- Amy J. Lim
- Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Murdoch Singapore, Singapore, Singapore
| | - Clement Lau
- School of Social Sciences, Singapore Management University, Singapore, Singapore
| | - Norman P. Li
- School of Social Sciences, Singapore Management University, Singapore, Singapore
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22
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Augusto JB, Johner N, Shah D, Nordin S, Knott KD, Rosmini S, Lau C, Alfarih M, Hughes R, Seraphim A, Vijapurapu R, Bhuva A, Lin L, Ojrzyńska N, Geberhiwot T, Captur G, Ramaswami U, Steeds RP, Kozor R, Hughes D, Moon JC, Namdar M. The myocardial phenotype of Fabry disease pre-hypertrophy and pre-detectable storage. Eur Heart J Cardiovasc Imaging 2021; 22:790-799. [PMID: 32514567 PMCID: PMC8219366 DOI: 10.1093/ehjci/jeaa101] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/07/2020] [Accepted: 04/15/2020] [Indexed: 11/17/2022] Open
Abstract
Aims Cardiac involvement in Fabry disease (FD) occurs prior to left ventricular hypertrophy (LVH) and is characterized by low myocardial native T1 with sphingolipid storage reflected by cardiovascular magnetic resonance (CMR) and electrocardiogram (ECG) changes. We hypothesize that a pre-storage myocardial phenotype might occur even earlier, prior to T1 lowering. Methods and results FD patients and age-, sex-, and heart rate-matched healthy controls underwent same-day ECG with advanced analysis and multiparametric CMR [cines, global longitudinal strain (GLS), T1 and T2 mapping, stress perfusion (myocardial blood flow, MBF), and late gadolinium enhancement (LGE)]. One hundred and fourteen Fabry patients (46 ± 13 years, 61% female) and 76 controls (49 ± 15 years, 50% female) were included. In pre-LVH FD (n = 72, 63%), a low T1 (n = 32/72, 44%) was associated with a constellation of ECG and functional abnormalities compared to normal T1 FD patients and controls. However, pre-LVH FD with normal T1 (n = 40/72, 56%) also had abnormalities compared to controls: reduced GLS (−18 ± 2 vs. −20 ± 2%, P < 0.001), microvascular changes (lower MBF 2.5 ± 0.7 vs. 3.0 ± 0.8 mL/g/min, P = 0.028), subtle T2 elevation (50 ± 4 vs. 48 ± 2 ms, P = 0.027), and limited LGE (%LGE 0.3 ± 1.1 vs. 0%, P = 0.004). ECG abnormalities included shorter P-wave duration (88 ± 12 vs. 94 ± 15 ms, P = 0.010) and T-wave peak time (Tonset – Tpeak; 104 ± 28 vs. 115 ± 20 ms, P = 0.015), resulting in a more symmetric T wave with lower T-wave time ratio (Tonset – Tpeak)/(Tpeak – Tend) (1.5 ± 0.4 vs. 1.8 ± 0.4, P < 0.001) compared to controls. Conclusion FD has a measurable myocardial phenotype pre-LVH and pre-detectable myocyte storage with microvascular dysfunction, subtly impaired GLS and altered atrial depolarization and ventricular repolarization intervals.
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Affiliation(s)
- João B Augusto
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Nicolas Johner
- Cardiology Division, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
| | - Dipen Shah
- Cardiology Division, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
| | - Sabrina Nordin
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Kristopher D Knott
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Stefania Rosmini
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Clement Lau
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK.,William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, London, UK
| | - Mashael Alfarih
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Rebecca Hughes
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Andreas Seraphim
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Ravi Vijapurapu
- Cardiology Department, University Hospitals Birmingham, Birmingham, UK
| | - Anish Bhuva
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Linda Lin
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Natalia Ojrzyńska
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK.,Institute of Cardiology, Warsaw, Poland
| | - Tarekegn Geberhiwot
- Inherited Metabolic Disorders Unit, University Hospitals Birmingham, Birmingham, UK
| | - Gabriella Captur
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Uma Ramaswami
- Royal Free London NHS Foundation Trust and University College London, London, UK
| | - Richard P Steeds
- Cardiology Department, University Hospitals Birmingham, Birmingham, UK
| | - Rebecca Kozor
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Derralynn Hughes
- Royal Free London NHS Foundation Trust and University College London, London, UK
| | - James C Moon
- Institute of Cardiovascular Science, University College London, London, UK.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, UK
| | - Mehdi Namdar
- Cardiology Division, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland
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23
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Gee LC, Massimo G, Lau C, Primus C, Fernandes D, Chen J, Rathod KS, Hamers AJP, Filomena F, Nuredini G, Ibrahim AS, Khambata RS, Gupta AK, Moon JC, Kapil V, Ahluwalia A. Inorganic nitrate attenuates cardiac dysfunction: role for xanthine oxidoreductase and nitric oxide. Br J Pharmacol 2021; 179:4757-4777. [PMID: 34309015 DOI: 10.1111/bph.15636] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 01/29/2021] [Revised: 07/01/2021] [Accepted: 07/03/2021] [Indexed: 11/28/2022] Open
Abstract
Nitric oxide (NO) is a vasodilator and independent modulator of cardiac remodelling. Commonly, in cardiac disease (e.g. heart failure) endothelial dysfunction (synonymous with NO-deficiency) has been implicated in increased blood pressure (BP), cardiac hypertrophy and fibrosis. Currently no effective therapies replacing NO have succeeded in the clinic. Inorganic nitrate (NO3 - ), through chemical reduction to nitrite and then NO, exerts potent BP-lowering but whether it might be useful in treating undesirable cardiac remodelling is unknown. In a nested age- and sex-matched case-control study of hypertensive patients +/- left ventricular hypertrophy (NCT03088514) we show that lower plasma nitrite concentration and vascular dysfunction accompany cardiac hypertrophy and fibrosis in patients. In mouse models of cardiac remodelling, we also show that restoration of circulating nitrite levels using dietary nitrate improves endothelial dysfunction through targeting of xanthine oxidoreductase (XOR)-driven H2 O2 and superoxide, and reduces cardiac fibrosis through NO-mediated block of SMAD-phosphorylation leading to improvements in cardiac structure and function. We show that via these mechanisms dietary nitrate offers easily translatable therapeutic options for treatment of cardiac dysfunction.
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Affiliation(s)
- Lorna C Gee
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Gianmichele Massimo
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Clement Lau
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Christopher Primus
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Daniel Fernandes
- Departamento de Farmacologia, Federal University of Santa Catarina, Florianópolis, Santa Catarina,, Brazil
| | - Jianmin Chen
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Krishnaraj S Rathod
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Alexander Jozua Pedro Hamers
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Federica Filomena
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Gani Nuredini
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Abdiwahab Shidane Ibrahim
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Rayomand S Khambata
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Ajay K Gupta
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - James C Moon
- UCL Institute of Cardiovascular Science, University College London, London, UK
| | - Vikas Kapil
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Amrita Ahluwalia
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
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Joy G, Artico J, Kurdi H, Lau C, Adam RD, Menacho KM, Pierce I, Captur G, Davies R, Schelbert EB, Fontana M, Kellman P, Treibel TA, Manisty C, Moon JC. Prospective case-control study of cardiovascular abnormalities six months following mild COVID-19 in healthcare workers. Eur Heart J Cardiovasc Imaging 2021. [PMCID: PMC8344927 DOI: 10.1093/ehjci/jeab090.064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Barts Charity UCLH Charity
OnBehalf
COVIDsortium
Background
Recent CMR studies have reported cardiac abnormalities after COVID-19 are common, even after mild, non-hospitalised illness with evidence of ongoing myocardial inflammation. Such a prevalence of chronic myocarditis after mild disease has prompted societal concerns in diverse domains, and suggests that screening should be considered post COVID-19, even in asymptomatic individuals. Cardiovascular magnetic resonance (CMR) has proven utility for diagnosis in patients with COVID-19 infection and elevated troponin from unclear causes by measuring cardiac structure, function, myocardial scar (late gadolinium enhancement) and oedema (T1 and T2 mapping).
Objectives
We aimed to determine the prevalence and extent of late cardiac and cardiovascular sequelae after mild non-hospitalised SARS-CoV-2 infection.
Methods
Participants were recruited from COVIDsortium, a three-hospital prospective study of 731 healthcare workers who underwent first wave weekly symptom, PCR and serology assessment over 4 months, with seroconversion in 21.5% (n = 157). At 6 months post infection, 74 seropositive and 75 age-, sex-, ethnicity-matched seronegative controls were recruited for cardiovascular phenotyping (comprehensive phantom-calibrated Cardiovascular Magnetic Resonance and blood biomarkers). Analysis was blinded, using objective AI analytics where available.
Results
149 subjects (mean age 37 years, range 18-63, 58% female) were recruited. Seropositive infections had been mild with case definition/non-case definition/asymptomatic disease in 45(61%), 18(24%) and 11(15%) with one person hospitalised (for 2 days). Between seropositive and seronegative groups, there were no differences in cardiac structure (left ventricular volumes, mass; atrial area), function (ejection fraction, global longitudinal shortening, aortic distensibility), tissue characterisation (T1, T2, ECV mapping, late gadolinium enhancement) or biomarkers (troponin, NT-proBNP). With abnormal defined by the 75 seronegatives (2 standard deviations from mean, e.g. EF < 54%, septal T1 > 1072ms, septal T2 > 52.4ms), individuals had abnormalities including reduced EF (n = 2, minimum 50%), T1 elevation (n = 6), T2 elevation (n = 9), LGE (n = 13, median 1%, max 5% of myocardium), biomarker elevation (borderline troponin elevation in 4; all NT-proBNP normal). These were distributed equally between seropositive and seronegative individuals.
Conclusions
Cardiovascular abnormalities are no more common in seropositive vs seronegative otherwise healthy, workforce representative individuals 6 months post mild SARS-CoV-2 infection. Our study provides societal reassurance for the cardiovascular health of working-aged individuals with convalescence from mild SARS-CoV-2. Screening asymptomatic individuals following mild diseases is not indicated.
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Affiliation(s)
- G Joy
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - J Artico
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - H Kurdi
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - C Lau
- Queen Mary University of London, London, United Kingdom of Great Britain & Northern Ireland
| | - RD Adam
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - KM Menacho
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - I Pierce
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - G Captur
- Royal Free Hospital, London, United Kingdom of Great Britain & Northern Ireland
| | - R Davies
- University College of London, London, United Kingdom of Great Britain & Northern Ireland
| | - EB Schelbert
- University of Pittsburgh, Pittsburgh, United States of America
| | - M Fontana
- Royal Free Hospital, London, United Kingdom of Great Britain & Northern Ireland
| | - P Kellman
- National Institutes of Health, Bethesda, United States of America
| | - TA Treibel
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - C Manisty
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - JC Moon
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
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25
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Lau C, Kalantari B, Batts KP, Ferrell LD, Nyberg SL, Graham RP, Moreira RK. The Voronoi theory of the normal liver lobular architecture and its applicability in hepatic zonation. Sci Rep 2021; 11:9343. [PMID: 33927276 PMCID: PMC8085188 DOI: 10.1038/s41598-021-88699-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 04/12/2021] [Indexed: 11/24/2022] Open
Abstract
The precise characterization of the lobular architecture of the liver has been subject of investigation since the earliest historical publications, but an accurate model to describe the hepatic lobular microanatomy is yet to be proposed. Our aim was to evaluate whether Voronoi diagrams can be used to describe the classic liver lobular architecture. We examined the histology of normal porcine and human livers and analyzed the geometric relationships of various microanatomic structures utilizing digital tools. The Voronoi diagram model described the organization of the hepatic classic lobules with overall accuracy nearly 90% based on known histologic landmarks. We have also designed a Voronoi-based algorithm of hepatic zonation, which also showed an overall zonal accuracy of nearly 90%. Therefore, we have presented evidence that Voronoi diagrams represent the basis of the two-dimensional organization of the normal liver and that this concept may have wide applicability in liver pathology and research.
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Affiliation(s)
- C Lau
- Department of Computer Science, Rutgers University, Brunswick, NJ, USA
| | - B Kalantari
- Department of Computer Science, Rutgers University, Brunswick, NJ, USA
| | | | - L D Ferrell
- Department of Pathology, University of California, San Francisco, CA, USA
| | - S L Nyberg
- Division of Transplantation Surgery, Department of Surgery, Mayo Clinic, Rochester, MN, USA
| | - R P Graham
- Department of Pathology and Laboratory Medicine, Mayo Clinic, Rochester, MN, USA
| | - Roger K Moreira
- Department of Pathology and Laboratory Medicine, Mayo Clinic, Rochester, MN, USA.
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Timofte I, Wells C, Hersi K, Ryan A, Varghese A, Vesselinov R, Iacono A, Assadi J, Davis D, Li G, Herr D, Harrington T, Griffith B, Lau C, Krupnick A, Madathil R, Rabin J, Alon G, Parker E, Baer D, Magder L, Terrin M, Verceles A. Nutritional Supplementation and Neuromuscular Electrical Stimulation in Lung Transplant Patients. J Heart Lung Transplant 2021. [DOI: 10.1016/j.healun.2021.01.1012] [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: 10/21/2022] Open
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27
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Joy G, Crane JD, Lau C, Augusto J, Brown LAE, Chowdhary A, Kotecha T, Plein S, Fontana M, Moon JC, Kellman P, Xue H, Cruickshank JK, Mcgowan BM, Manisty C. Impact of obesity on myocardial microvasculature assessed using fully-automated inline myocardial perfusion mapping CMR. Eur Heart J Cardiovasc Imaging 2021. [DOI: 10.1093/ehjci/jeaa356.296] [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
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Guy"s and St Thomas" Charity University College London Hospitals Biomedical Research Centre
Background
Obesity and cardiovascular disease are associated, but the relationship is poorly understood. Myocardial perfusion, metabolic derangement and lipotoxicity appear adversely associated in many scenarios (myocardial injury, diastolic dysfunction, diabetes). Altered perfusion (by PET) predicts outcome, and it is hypothesised that perfusion derangement is part of causality for cardiac disease and adverse outcomes.
Purpose
To assess the presence and pattern of myocardial microvascular dysfunction in patients with obesity (scheduled for bariatric surgery) using stress quantitative perfusion mapping.
Methods
38 subjects with obesity planned to undergo bariatric surgery and 38 age and sex matched healthy volunteers (no diabetes, no hypertension) underwent anthropometry, biochemistry and CMR at 1.5T (Siemens) with cine imaging, stress (adenosine 140-210 mcg/kg/min) and rest fully-automated quantitative perfusion mapping.
Results
Bariatric patients had a higher BMI (44 ± 6.4 vs 26.5 ± 4kg/m2 p = 0.001); 58%(22) were diabetic and 58%(22) had hypertension. Bariatric patients had higher absolute but lower indexed end-diastolic volumes, and overall higher ejection fractions (+5%) (see Table). Rest myocardial blood flow (MBF) in bariatric patients was the same (1.00 ± 0.3 vs 0.88 ± 0.24 p = 0.052), but stress perfusion results were significantly lower both for stress MBF (2.35 ± 0.69 vs 2.93 ± 0.76ml/g/min p = 0.001) and myocardial perfusion reserve (MPR 2.48 ± 0.82 vs 3.4 ± 0.81ml/g/min p = 0.0001). Although this was transmural, the endocardial stress MBF was particularly negatively affected in the bariatric cohort compared to controls (endocardial MBF 2.16 ± 0.65 vs 2.82 ± 0.73ml/g/min, p = 0.0001 vs epicardial MBF: 2.52 ± 0.76 vs 3.06 ± 0.79 p = 0.003), meaning there was an increased endo-epicardial stress MBF gradient in bariatric patients (0.87 ± 0.12 vs 0.92 ± 0.07 p = 0.03).
Conclusion
Compared to healthy controls, patients with obesity have abnormal myocardial stress perfusion with reduced global perfusion, perfusion reserve and an increased transmyocardial perfusion gradient.
Table - myocardial perfusion parameters Category Bariatric patients n = 38 Controls n = 38 p value Age (years) 48 ± 11 45 ± 13 0.25 n male (%) 12 (32%) 10 (36%) 0.32 LVEDV (ml) 168 ± 37 149 ± 31 0.017 LVEDVi (ml/m2) 70.4 ± 12.3 78.8 ± 12.1 0.004 LV Mass (g) 116 ± 31 99 ± 28 0.019 EF (%) 70 ± 8 65 ± 5 0.002 LVEDV - left ventricular end-diastolic volume, EF - ejection fraction
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Affiliation(s)
- G Joy
- Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - JD Crane
- King"s College London, Department of Diabetes and Nutritional Sciences, London, United Kingdom of Great Britain & Northern Ireland
| | - C Lau
- Queen Mary University of London, London, United Kingdom of Great Britain & Northern Ireland
| | - J Augusto
- University College London, Institute of Cardiovascular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - LAE Brown
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - A Chowdhary
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - T Kotecha
- Royal Free Hospital, London, United Kingdom of Great Britain & Northern Ireland
| | - S Plein
- University of Leeds, Leeds Institute of Cardiovascular and Metabolic Medicine, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - M Fontana
- University College London, Institute of Cardiovascular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - JC Moon
- University College London, Institute of Cardiovascular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - P Kellman
- National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, United States of America
| | - H Xue
- National Institutes of Health, National Heart, Lung, and Blood Institute, Bethesda, United States of America
| | - JK Cruickshank
- King"s College London, Department of Diabetes and Nutritional Sciences, London, United Kingdom of Great Britain & Northern Ireland
| | - BM Mcgowan
- King"s College London, Department of Diabetes and Nutritional Sciences, London, United Kingdom of Great Britain & Northern Ireland
| | - C Manisty
- University College London, Institute of Cardiovascular Science, London, United Kingdom of Great Britain & Northern Ireland
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Bhuva AN, Treibel TA, Seraphim A, Scully P, Knott KD, Augusto JB, Torlasco C, Menacho K, Lau C, Patel K, Moon JC, Kellman P, Manisty CH. Measurement of T1 Mapping in Patients With Cardiac Devices: Off-Resonance Error Extends Beyond Visual Artifact but Can Be Quantified and Corrected. Front Cardiovasc Med 2021; 8:631366. [PMID: 33585589 PMCID: PMC7878555 DOI: 10.3389/fcvm.2021.631366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/07/2021] [Indexed: 11/24/2022] Open
Abstract
Background: Measurement of myocardial T1 is increasingly incorporated into standard cardiovascular magnetic resonance (CMR) protocols, however accuracy may be reduced in patients with metallic cardiovascular implants. Measurement is feasible in segments free from visual artifact, but there may still be off-resonance induced error. Aim: To quantify off-resonance induced T1 error in patients with metallic cardiovascular implants, and validate a method for error correction for a conventional MOLLI pulse sequence. Methods: Twenty-four patients with cardiac implantable electronic devices (CIEDs: 46% permanent pacemakers, PPMs; 33% implantable loop recorders, ILRs; and 21% implantable cardioverter-defibrillators, ICDs); and 31 patients with aortic valve replacement (AVR) (45% metallic) were studied. Paired mid-myocardial short-axis MOLLI and single breath-hold off-resonance field maps were acquired at 1.5 T. T1 values were measured by AHA segment, and segments with visual artifact were excluded. T1 correction was applied using a published relationship between off-resonance and T1. The accuracy of the correction was assessed in 10 healthy volunteers by measuring T1 before and after external placement of an ICD generator next to the chest to generate off-resonance. Results: T1 values in healthy volunteers with an ICD were underestimated compared to without (967 ± 52 vs. 997 ± 26 ms respectively, p = 0.0001), but were similar after correction (p = 0.57, residual difference 2 ± 27 ms). Artifact was visible in 4 ± 12, 42 ± 31, and 53 ± 27% of AHA segments in patients with ILRs, PPMs, and ICDs, respectively. In segments without artifact, T1 was underestimated by 63 ms (interquartile range: 7–143) per patient. The greatest error for patients with ILRs, PPMs and ICDs were 79, 146, and 191 ms, respectively. The presence of an AVR did not generate T1 error. Conclusion: Even when there is no visual artifact, there is error in T1 in patients with CIEDs, but not AVRs. Off-resonance field map acquisition can detect error in measured T1, and a correction can be applied to quantify T1 MOLLI accurately.
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Affiliation(s)
- Anish N Bhuva
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Thomas A Treibel
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Andreas Seraphim
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Paul Scully
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Kristopher D Knott
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - João B Augusto
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Camilla Torlasco
- Istituto Auxologico Italiano (IRCCS), Istituto Auxologico Italiano, Milan, Italy
| | - Katia Menacho
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Clement Lau
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Kush Patel
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - James C Moon
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Peter Kellman
- National Institutes of Health, Bethesda, MD, United States
| | - Charlotte H Manisty
- Institute for Cardiovascular Science, University College London, London, United Kingdom.,Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
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29
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Augusto JB, Davies RH, Bhuva AN, Knott KD, Seraphim A, Alfarih M, Lau C, Hughes RK, Lopes LR, Shiwani H, Treibel TA, Gerber BL, Hamilton-Craig C, Ntusi NAB, Pontone G, Desai MY, Greenwood JP, Swoboda PP, Captur G, Cavalcante J, Bucciarelli-Ducci C, Petersen SE, Schelbert E, Manisty C, Moon JC. Diagnosis and risk stratification in hypertrophic cardiomyopathy using machine learning wall thickness measurement: a comparison with human test-retest performance. Lancet Digit Health 2021; 3:e20-e28. [PMID: 33735065 DOI: 10.1016/s2589-7500(20)30267-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 10/10/2020] [Accepted: 10/14/2020] [Indexed: 01/26/2023]
Abstract
BACKGROUND Left ventricular maximum wall thickness (MWT) is central to diagnosis and risk stratification of hypertrophic cardiomyopathy, but human measurement is prone to variability. We developed an automated machine learning algorithm for MWT measurement and compared precision (reproducibility) with that of 11 international experts, using a dataset of patients with hypertrophic cardiomyopathy. METHODS 60 adult patients with hypertrophic cardiomyopathy, including those carrying hypertrophic cardiomyopathy gene mutations, were recruited at three institutes in the UK from August, 2018, to September, 2019: Barts Heart Centre, University College London Hospital (The Heart Hospital), and Leeds Teaching Hospitals NHS Trust. Participants had two cardiovascular magnetic resonance scans (test and retest) on the same day, ensuring no biological variability, using four cardiac MRI scanner models represented across two manufacturers and two field strengths. End-diastolic short-axis MWT was measured in test and retest by 11 international experts (from nine centres in six countries) and an automated machine learning method, which was trained to segment endocardial and epicardial contours on an independent, multicentre, multidisease dataset of 1923 patients. Machine learning MWT measurement was done with a method based on solving Laplace's equation. To assess test-retest reproducibility, we estimated the absolute test-retest MWT difference (precision), the coefficient of variation (CoV) for duplicate measurements, and the number of patients reclassified between test and retest according to different thresholds (MWT >15 mm and >30 mm). We calculated the sample size required to detect a prespecified MWT change between pairs of scans for machine learning and each expert. FINDINGS 1440 MWT measurements were analysed, corresponding to two scans from 60 participants by 12 observers (11 experts and machine learning). Experts differed in the MWT they measured, ranging from 14·9 mm (SD 4·2) to 19·0 mm (4·7; p<0·0001 for trend). Machine learning-measured mean MWT was 16·8 mm (4·1). Machine learning precision was superior, with a test-retest difference of 0·7 mm (0·6) compared with experts, who ranged from 1·1 mm (0·9) to 3·7 mm (2·0; p values for machine learning vs expert comparison ranging from <0·0001 to 0·0073) and a significantly lower CoV than for all experts (4·3% [95% CI 3·3-5·1] vs 5·7-12·1% across experts). On average, 38 (64%) patients were designated as having MWT greater than 15 mm by machine learning compared with 27 (45%) to 50 (83%) patients by experts; five (8%) patients were reclassified in test-retest by machine learning compared with four (7%) to 12 (20%) by experts. With a cutoff point of more than 30 mm for implantable cardioverter-defibrillator, three experts would have changed recommendations between tests a total of four times, but machine learning was consistent. Using machine learning, a clinical trial to detect a 2 mm MWT change would need 2·3 times (range 1·6-4·6) fewer patients. INTERPRETATION In this preliminary study, machine learning MWT measurement in hypertrophic cardiomyopathy is superior to human experts with potential implications for diagnosis, risk stratification, and clinical trials. FUNDING European Regional Development Fund and Barts Charity.
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Affiliation(s)
- João B Augusto
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Rhodri H Davies
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Anish N Bhuva
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Kristopher D Knott
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Andreas Seraphim
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Mashael Alfarih
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Clement Lau
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, London, UK
| | - Rebecca K Hughes
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Luís R Lopes
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Hunain Shiwani
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK
| | - Thomas A Treibel
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - Bernhard L Gerber
- Division of Cardiology, Department of Cardiovascular Diseases, Cliniques Universitaires St Luc UCL, Woluwe St Lambert, Belgium; Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Christian Hamilton-Craig
- The Prince Charles Hospital, Brisbane, QLD, Australia; Centre for Advanced Imaging, University of Queensland and Griffith University School of Medicine, QLD, Australia
| | - Ntobeko A B Ntusi
- Division of Cardiology, Department of Medicine, University of Cape Town and Groote Schuur Hospital, Cape Town, South Africa; Hatter Institute of Cardiovascular Research in Africa and Cape Universities Body Imaging Centre, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Gianluca Pontone
- Department of Cardiovascular Imaging, Centro Cardiologico Monzino IRCCS, Milan, Italy
| | - Milind Y Desai
- Heart and Vascular Institute Cleveland Clinic, Cleveland, OH, USA
| | - John P Greenwood
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, and Leeds Teaching Hospitals NHS Trust, UK
| | - Peter P Swoboda
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, and Leeds Teaching Hospitals NHS Trust, UK
| | - Gabriella Captur
- Institute of Cardiovascular Science, University College London, London, UK
| | - João Cavalcante
- Minneapolis Heart Institute, Department of Cardiology, Abbott Northwestern Hospital, Minneapolis, MN, USA; Valve Science Center, Minneapolis Heart Institute Foundation, Minneapolis, MN, USA
| | - Chiara Bucciarelli-Ducci
- Bristol Heart Institute, Bristol National Institute of Health Research Biomedical Research Centre, University Hospitals Bristol NHS Trust and University of Bristol, Bristol, UK
| | - Steffen E Petersen
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, London, UK
| | - Erik Schelbert
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Cardiovascular Magnetic Resonance Center, UPMC Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Charlotte Manisty
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK
| | - James C Moon
- Cardiac Imaging Department, Barts Heart Centre, St Bartholomew's Hospital, London, UK; Institute of Cardiovascular Science, University College London, London, UK.
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Lim A, N.A.Rahim, Periyasamy P, Mat W, Lau C. Mortality and microbiological clearance among critically ill patients receiving Polymyxin B in a Malaysian ICU: A 10 years retrospective study. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.724] [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: 11/26/2022] Open
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Bicho Augusto J, Johner N, Shah D, Nordin S, Knott K, Lau C, Alfarih M, Seraphim A, Vijapurapu R, Ramaswami U, Steeds R, Kozor R, Hughes D, Moon J, Namdar M. The myocardial phenotype of Fabry disease pre-hypertrophy and pre-detectable storage. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.2132] [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: 11/14/2022] Open
Abstract
Abstract
Background
Cardiac involvement in Fabry Disease (FD) occurs prior to left ventricular hypertrophy (LVH) and is characterized by low myocardial native T1 with storage reflected by cardiovascular magnetic resonance (CMR) and ECG changes.
Objectives
We hypothesize that a pre-storage myocardial phenotype might occur even earlier, prior to T1 lowering.
Methods
FD patients and age, sex and heart rate matched healthy controls underwent same-day ECG with advanced analysis and multiparametric CMR (cines, global longitudinal strain [GLS], T1 and T2 mapping, stress perfusion [myocardial blood flow, MBF] and late gadolinium enhancement [LGE]).
Results
114 Fabry patients (46±13 years, 61% female) and 76 controls (49±15 years, 50% female) were included. In pre-LVH FD (n=72, 63%), a low T1 (n=32/72, 44%) was associated with a constellation of ECG and functional abnormalities compared to normal T1 FD patients and controls. However, pre-LVH FD with normal T1 (n=40/72, 56%) also had abnormalities compared to controls: reduced GLS (−18±2 vs −20±2%, P<0.001), microvascular changes (lower MBF 2.5±0.7 vs 3.0±0.8mL/g/min, P=0.028), subtle T2 elevation (50±4 vs 48±2ms, p=0.027) and limited LGE (%LGE 0.3±1.1 vs 0%, P=0.004). ECG abnormalities included shorter P wave duration (88±12 vs 94±15ms, P=0.010) and T wave peak time (Tonset–Tpeak; 104±28 vs 115±20ms, P=0.015), resulting in a more symmetric T wave with lower T wave time ratio (Tonset–Tpeak)/(Tpeak–Tend) (1.5±0.4 vs 1.8±0.4, P<0.001) compared to controls.
Conclusions
FD has a measurable myocardial phenotype pre-LVH and pre-detectable myocyte storage with microvascular dysfunction, subtly impaired GLS and altered atrial depolarization and ventricular repolarization intervals.
Proposed stages of cardiac involvement
Funding Acknowledgement
Type of funding source: None
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Affiliation(s)
| | - N Johner
- Geneva University Hospitals, Cardiology Division, Geneva, Switzerland
| | - D Shah
- Geneva University Hospitals, Cardiology Division, Geneva, Switzerland
| | - S Nordin
- Barts Health NHS Trust, London, United Kingdom
| | - K Knott
- University College London, London, United Kingdom
| | - C Lau
- Barts Health NHS Trust, London, United Kingdom
| | - M Alfarih
- University College London, London, United Kingdom
| | - A Seraphim
- University College London, London, United Kingdom
| | - R Vijapurapu
- Queen Elizabeth Hospital Birmingham, Department of Cardiology, Birmingham, United Kingdom
| | - U Ramaswami
- Royal Free Hospital, lysosomal storage disorders unit, London, United Kingdom
| | - R Steeds
- Queen Elizabeth Hospital Birmingham, Department of Cardiology, Birmingham, United Kingdom
| | - R Kozor
- University of Sydney, Sydney Medical School, Sydney, Australia
| | - D Hughes
- Royal Free Hospital, lysosomal storage disorders unit, London, United Kingdom
| | - J Moon
- Barts Health NHS Trust, London, United Kingdom
| | - M Namdar
- Geneva University Hospitals, Cardiology Division, Geneva, Switzerland
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Lau C, Turcich MR, Smith EO. Early detection of parenting stress in mothers of preterm infants during their first-year home. BMC Psychol 2020; 8:66. [PMID: 32576260 PMCID: PMC7313173 DOI: 10.1186/s40359-020-00435-z] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 06/17/2020] [Indexed: 11/11/2022] Open
Abstract
Background Maternal stress following the birth of an infant is well acknowledged. It is particularly so when infants are born prematurely as their mothers cannot fully take on their parenting role until their infant(s) is discharged from neonatal intensive care units (NICUs). In this exploratory study, we examined whether these mothers’ parenting stress would lessen during their first-year reunification with their infant(s) as they settle into motherhood at home. Methods Two groups of mothers with infants born between 24- and 33-week gestational age were recruited. A group of 25 mothers were monitored at their infants’ 1-month corrected age (CA) and a second group of 24 mothers were monitored at their infants’ 12-month CA. Subjects completed the long form Parental Stress Index (PSI) ranking how stressful they perceive the individual subscales in the Child and Parent Domains of the self-reported questionnaire (PSI-3; Abidin; PAR Inc). The PSI theorizes that the stress mothers perceive is a resultant of their respective characteristics, interactions with their infant(s), family, and environment. Statistical analyses include descriptive statistics, χ2 square analysis, and independent t-test. Results There was no significant difference in the levels of perceived stress in the PSI subscales between the two groups of mothers at 1- and 12-month CA. Scores for the majority of respondents fell within the 15th to 80th percentile (% ile) distribution of Abidin’s normative population, with some mothers falling below the 15th % ile. Discussion/conclusion The data collected suggest that: 1. the perceived stress experienced by mothers during their first-year reunited with their preterm infants is within the normal range observed in Abidin’s normative population. 2. As the PSI is a self-reported survey, care providers need to be aware that some mothers may downplay their stress responses. 3. With the ability to monitor individual participants, the PSI can be readily offered to mothers at their infants’ first year routine clinical visits to assist in the early identification of parenting issues that may threaten the development of a healthy mother-infant dyad. Early appropriate guidance and social support would help “at-risk” mothers develop more constructive parenting routines.
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Affiliation(s)
- C Lau
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - M R Turcich
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - E O Smith
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, 77030, USA
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Farry T, Lau C, Keates H, McEwen M, Woldeyohannes S, Barnes T, Perkins N, Goodwin W. Comparison of two formulations of alfaxalone in laboratory zebra fish (Danio rerio) for use in immersion anaesthesia. Vet Anaesth Analg 2019. [DOI: 10.1016/j.vaa.2019.08.017] [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: 11/26/2022]
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34
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Bhuva A, Bai W, Lau C, Davies R, Ye Y, Bulluck H, McAlindon E, Culotta V, Swoboda P, Captur G, Treibel T, Augusto J, Knott K, Seraphim A, Cole G, Petersen S, Edwards N, Greenwood J, Bucciarelli-Ducci C, Hughes A, Rueckert D, Moon J, Manisty C. A Multicenter, Scan-Rescan, Human and Machine Learning CMR Study to Test Generalizability and Precision in Imaging Biomarker Analysis. Circ Cardiovasc Imaging 2019; 12:e009214. [PMID: 31547689 DOI: 10.1161/circimaging.119.009214] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/25/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Automated analysis of cardiac structure and function using machine learning (ML) has great potential, but is currently hindered by poor generalizability. Comparison is traditionally against clinicians as a reference, ignoring inherent human inter- and intraobserver error, and ensuring that ML cannot demonstrate superiority. Measuring precision (scan:rescan reproducibility) addresses this. We compared precision of ML and humans using a multicenter, multi-disease, scan:rescan cardiovascular magnetic resonance data set. METHODS One hundred ten patients (5 disease categories, 5 institutions, 2 scanner manufacturers, and 2 field strengths) underwent scan:rescan cardiovascular magnetic resonance (96% within one week). After identification of the most precise human technique, left ventricular chamber volumes, mass, and ejection fraction were measured by an expert, a trained junior clinician, and a fully automated convolutional neural network trained on 599 independent multicenter disease cases. Scan:rescan coefficient of variation and 1000 bootstrapped 95% CIs were calculated and compared using mixed linear effects models. RESULTS Clinicians can be confident in detecting a 9% change in left ventricular ejection fraction, with greater than half of coefficient of variation attributable to intraobserver variation. Expert, trained junior, and automated scan:rescan precision were similar (for left ventricular ejection fraction, coefficient of variation 6.1 [5.2%-7.1%], P=0.2581; 8.3 [5.6%-10.3%], P=0.3653; 8.8 [6.1%-11.1%], P=0.8620). Automated analysis was 186× faster than humans (0.07 versus 13 minutes). CONCLUSIONS Automated ML analysis is faster with similar precision to the most precise human techniques, even when challenged with real-world scan:rescan data. Assessment of multicenter, multi-vendor, multi-field strength scan:rescan data (available at www.thevolumesresource.com) permits a generalizable assessment of ML precision and may facilitate direct translation of ML to clinical practice.
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Affiliation(s)
- Anish Bhuva
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Wenjia Bai
- Institute for Cardiovascular Science, University College London, United Kingdom
| | - Clement Lau
- Institute for Cardiovascular Science, University College London, United Kingdom
| | - Rhodri Davies
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Yang Ye
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Heeraj Bulluck
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Elisa McAlindon
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Veronica Culotta
- Institute for Cardiovascular Science, University College London, United Kingdom
| | - Peter Swoboda
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Gabriella Captur
- Institute for Cardiovascular Science, University College London, United Kingdom
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Thomas Treibel
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
- Imperial College London, South Kensington Campus, United Kingdom. William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, United Kingdom
| | - Joao Augusto
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Kristopher Knott
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
- Department of Cardiology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, People's Republic of China
| | - Andreas Seraphim
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
| | - Graham Cole
- Department of Cardiovascular Imaging, Barts Heart Centre, Barts Health NHS Trust, London, United Kingdom
- Imperial College London, South Kensington Campus, United Kingdom. William Harvey Research Institute, NIHR Barts Biomedical Research Centre, Queen Mary University of London, United Kingdom
| | - Steffen Petersen
- Data Science Institute and Department of Medicine (W.B.),
Department of Computing
| | | | - John Greenwood
- Bristol Heart Institute, Bristol NIHR Biomedical Research Centre, University Hospitals Bristol NHS Trust and University
of Bristol, United Kingdom
- Heart and Lung Centre, New Cross Hospital, Wolverhampton, United Kingdom
| | - Chiara Bucciarelli-Ducci
- Bristol Heart Institute, Bristol NIHR Biomedical Research Centre, University Hospitals Bristol NHS Trust and University
of Bristol, United Kingdom
| | - Alun Hughes
- Multidisciplinary Cardiovascular Research Centre and Division of Biomedical Imaging, Leeds Institute of Cardiovascular
and Metabolic Medicine, University of Leeds, United Kingdom
| | - Daniel Rueckert
- Multidisciplinary Cardiovascular Research Centre and Division of Biomedical Imaging, Leeds Institute of Cardiovascular
and Metabolic Medicine, University of Leeds, United Kingdom
| | - James Moon
- Imperial College London, National Heart and Lung Institute, Hammersmith Hospital, United Kingdom
| | - Charlotte Manisty
- Auckland City Hospital, New Zealand and Institute of Cardiovascular Science, University of Birmingham
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Caneses JF, Piotrowicz PA, Biewer TM, Goulding RH, Lau C, Showers M, Rapp J. Ion Fluxes and Neutral Gas Ionization Efficiency of the 100-kW Light-Ion Helicon Plasma Source Concept for the Material Plasma Exposure eXperiment. Fusion Science and Technology 2019. [DOI: 10.1080/15361055.2019.1622988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- J. F. Caneses
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - P. A. Piotrowicz
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- University of Illinois at Urbana-Champaign, Department of Nuclear, Plasma and Radiological Engineering, Center for Plasma-Material Interactions, Urbana, Illinois 61801
| | - T. M. Biewer
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - R. H. Goulding
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - C. Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - M. Showers
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
- University of Tennessee, Knoxville, Tennessee 37996
| | - J. Rapp
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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36
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Bhuva A, Bai W, Lau C, Davies R, Yang Y, Bulluck H, Mcalindon E, Cole GD, Petersen SE, Greenwood JP, Bucciarelli-Ducci C, Hughes AD, Rueckert D, Moon JC, Manisty CH. 349Fully automated left ventricular analysis matches clinician precision: a multi-centre, multi-vendor, multi-field strength, multi-disease scan:rescan CMR study. Eur Heart J Cardiovasc Imaging 2019. [DOI: 10.1093/ehjci/jez103.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A Bhuva
- University College London, Institute of Cardiovasular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - W Bai
- Imperial College London, London, United Kingdom of Great Britain & Northern Ireland
| | - C Lau
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - R Davies
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - Y Yang
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - H Bulluck
- University College London, Institute of Cardiovasular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - E Mcalindon
- Bristol Heart Institute, Bristol, United Kingdom of Great Britain & Northern Ireland
| | - G D Cole
- Imperial College London, London, United Kingdom of Great Britain & Northern Ireland
| | - S E Petersen
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - J P Greenwood
- University of Leeds, Leeds, United Kingdom of Great Britain & Northern Ireland
| | - C Bucciarelli-Ducci
- Bristol Heart Institute, Bristol, United Kingdom of Great Britain & Northern Ireland
| | - A D Hughes
- University College London, Institute of Cardiovasular Science, London, United Kingdom of Great Britain & Northern Ireland
| | - D Rueckert
- Imperial College London, London, United Kingdom of Great Britain & Northern Ireland
| | - J C Moon
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
| | - C H Manisty
- Barts Health NHS Trust, Barts Heart Centre, London, United Kingdom of Great Britain & Northern Ireland
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37
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Illes J, McCall IC, Lau C, Minielly N. Ethical considerations for brain recording and stimulating neurotechnologies available in the open marketplace. Brain Stimul 2019. [DOI: 10.1016/j.brs.2018.12.964] [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: 10/27/2022] Open
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38
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Donald PM, Illes J, Lau C, McCall IC. Regulatory oversight for DBS: Current framework for device recall in North America. Brain Stimul 2019. [DOI: 10.1016/j.brs.2018.12.966] [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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39
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Landsem A, Fure H, Krey Ludviksen J, Christiansen D, Lau C, Mathisen M, Bergseth G, Nymo S, Lappegård KT, Woodruff TM, Espevik T, Mollnes TE, Brekke OL. Complement component 5 does not interfere with physiological hemostasis but is essential for Escherichia coli-induced coagulation accompanied by Toll-like receptor 4. Clin Exp Immunol 2018; 196:97-110. [PMID: 30444525 PMCID: PMC6422650 DOI: 10.1111/cei.13240] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2018] [Indexed: 12/18/2022] Open
Abstract
There is a close cross-talk between complement, Toll-like receptors (TLRs) and coagulation. The role of the central complement component 5 (C5) in physiological and pathophysiological hemostasis has not, however, been fully elucidated. This study examined the effects of C5 in normal hemostasis and in Escherichia coli-induced coagulation and tissue factor (TF) up-regulation. Fresh whole blood obtained from six healthy donors and one C5-deficient individual (C5D) was anti-coagulated with the thrombin inhibitor lepirudin. Blood was incubated with or without E. coli in the presence of the C5 inhibitor eculizumab, a blocking anti-CD14 monoclonal antibody (anti-CD14) or the TLR-4 inhibitor eritoran. C5D blood was reconstituted with purified human C5. TF mRNA was measured by quantitative polymerase chain reaction (qPCR) and monocyte TF and CD11b surface expression by flow cytometry. Prothrombin fragment 1+2 (PTF1·2) in plasma and microparticles exposing TF (TF-MP) was measured by enzyme-linked immunosorbent assay (ELISA). Coagulation kinetics were analyzed by rotational thromboelastometry and platelet function by PFA-200. Normal blood with eculizumab as well as C5D blood with or without reconstitution with C5 displayed completely normal biochemical hemostatic patterns. In contrast, E. coli-induced TF mRNA and TF-MP were significantly reduced by C5 inhibition. C5 inhibition combined with anti-CD14 or eritoran completely inhibited the E. coli-induced monocyte TF, TF-MP and plasma PTF1·2. Addition of C5a alone did not induce TF expression on monocytes. In conclusion, C5 showed no impact on physiological hemostasis, but substantially contributed to E. coli-induced procoagulant events, which were abolished by the combined inhibition of C5 and CD14 or TLR-4.
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Affiliation(s)
- A Landsem
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway.,Department of Clinical Medicine, UiT - The Arctic University of Norway, Tromsø, Norway
| | - H Fure
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - J Krey Ludviksen
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - D Christiansen
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - C Lau
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - M Mathisen
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - G Bergseth
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway
| | - S Nymo
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway.,Division of Medicine, Nordland Hospital Trust, Bodø, Norway
| | - K T Lappegård
- Department of Clinical Medicine, UiT - The Arctic University of Norway, Tromsø, Norway.,Division of Medicine, Nordland Hospital Trust, Bodø, Norway
| | - T M Woodruff
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - T Espevik
- Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - T E Mollnes
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway.,Department of Clinical Medicine, UiT - The Arctic University of Norway, Tromsø, Norway.,K. G. Jebsen TREC, UiT - The Arctic University of Norway, Tromsø, Norway.,Department of Immunology, Oslo University Hospital Rikshospitalet and University of Oslo, Norway.,Centre of Molecular Inflammation Research, and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - O-L Brekke
- Research Laboratory and Department of Laboratory Medicine, Nordland Hospital Trust, Bodø, Norway.,Department of Clinical Medicine, UiT - The Arctic University of Norway, Tromsø, Norway
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40
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Gupta R, Chevalier D, Saluja J, Lau C, Wang C, Fakih M. ctDNA assays identify alterations in RAS, EGFR, and cMET that are unique to RAS-WT patients progressing on anti-EGFR therapy. Ann Oncol 2018. [DOI: 10.1093/annonc/mdy281.090] [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: 11/13/2022] Open
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41
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Amanam I, Chao J, Lim D, Rahmanuddin S, Schrock A, Ali S, Lau C, Chevalier D, Harris E, Saluja J, Wang C, Fakih M. Lower tumor mutational burden (TMB) and hepatic metastases may predict for lack of response to PD-1 blockade in MSI-H metastatic colorectal cancer (MCRC). Ann Oncol 2018. [DOI: 10.1093/annonc/mdy281.081] [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: 11/14/2022] Open
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42
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Martin EH, Lau C, Brookman MW, Lohr J. A spectroscopic electric field vector imaging diagnostic for electron cyclotron heating systems. Rev Sci Instrum 2018; 89:10D117. [PMID: 30399893 DOI: 10.1063/1.5038670] [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: 05/04/2018] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
An experimental measurement of the wave electric field vector provides important data that can be used to directly compare against 3D full-wave simulations. This direct comparison yields the fastest approach toward identifying missing physics in computational models and providing a high fidelity validation platform. In this paper, we present a diagnostic that is capable of imaging the Electron Cyclotron (EC) wave electric field vector by acquiring filtered images of polarized D β spectral satellites. The diagnostic is designed to have a spatial and temporal resolution on the order of 100 μm and 100 μs, respectively. The diagnostic purpose is to provide experimental data for the direct validation of full-wave codes used to predict EC beam propagation and absorption and to provide real-time monitoring of EC waves.
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Affiliation(s)
- E H Martin
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
| | - M W Brookman
- General Atomics, 3550 General Atomics Ct., San Diego, California 92121, USA
| | - J Lohr
- General Atomics, 3550 General Atomics Ct., San Diego, California 92121, USA
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43
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Schmitz L, Deng B, Thompson M, Gota H, Lau C, Fulton DP, Lin Z, Tajima T, Binderbauer M. Combination Doppler backscattering/cross-polarization scattering diagnostic for the C-2W field-reversed configuration. Rev Sci Instrum 2018; 89:10H116. [PMID: 30399746 DOI: 10.1063/1.5038914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
A versatile combination Doppler backscattering and Cross-Polarization Scattering (CPS) diagnostic for the C-2W beam-driven field-reversed configuration is described. This system is capable of measuring density fluctuations and perpendicular magnetic field fluctuations across a wide wavenumber range (2.5 ≤ k θ ρ s ≤ 50), with typical resolution Δk θ/k θ ≤ 0.4-0.8. Four tunable frequencies (26 GHz ≤ f ≤ 60 GHz corresponding to plasma cut-off densities 0.8 × 1019 ≤ n e ≤ 4.4 × 1019 m-3) are launched via quasi-optical beam combiners/polarizers and an adjustable parabolic focusing mirror selecting the beam incidence angle. GENRAY ray tracing shows that the incident O-mode and backscattered CPS X-mode beam trajectories for C-2W plasma parameters nearly overlap, allowing simultaneous detection of ñ and B̃ r or B̃ θ from essentially the same scattering volume.
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Affiliation(s)
- L Schmitz
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - B Deng
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - M Thompson
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - H Gota
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - C Lau
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - D P Fulton
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - Z Lin
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, USA
| | - T Tajima
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
| | - M Binderbauer
- TAE Technologies, Inc., Foothill Ranch, California 92610, USA
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44
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Lau C. Effect of short-term high-intensity noise exposure on auditory physiology: a functional magnetic resonance imaging study. Hong Kong Med J 2018; 24 Suppl 4:46-47. [PMID: 30135276] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Affiliation(s)
- C Lau
- Department of Physics, City University of Hong Kong
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45
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Spong DA, Heidbrink WW, Paz-Soldan C, Du XD, Thome KE, Van Zeeland MA, Collins C, Lvovskiy A, Moyer RA, Austin ME, Brennan DP, Liu C, Jaeger EF, Lau C. First Direct Observation of Runaway-Electron-Driven Whistler Waves in Tokamaks. Phys Rev Lett 2018; 120:155002. [PMID: 29756886 DOI: 10.1103/physrevlett.120.155002] [Citation(s) in RCA: 3] [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: 12/08/2017] [Indexed: 06/08/2023]
Abstract
DIII-D experiments at low density (n_{e}∼10^{19} m^{-3}) have directly measured whistler waves in the 100-200 MHz range excited by multi-MeV runaway electrons. Whistler activity is correlated with runaway intensity (hard x-ray emission level), occurs in novel discrete frequency bands, and exhibits nonlinear limit-cycle-like behavior. The measured frequencies scale with the magnetic field strength and electron density as expected from the whistler dispersion relation. The modes are stabilized with increasing magnetic field, which is consistent with wave-particle resonance mechanisms. The mode amplitudes show intermittent time variations correlated with changes in the electron cyclotron emission that follow predator-prey cycles. These can be interpreted as wave-induced pitch angle scattering of moderate energy runaways. The tokamak runaway-whistler mechanisms have parallels to whistler phenomena in ionospheric plasmas. The observations also open new directions for the modeling and active control of runaway electrons in tokamaks.
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Affiliation(s)
- D A Spong
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - W W Heidbrink
- University of California-Irvine, Irvine, California 92697, USA
| | - C Paz-Soldan
- General Atomics, San Diego, California 92186-5608, USA
| | - X D Du
- University of California-Irvine, Irvine, California 92697, USA
| | - K E Thome
- Oak Ridge Associated Universities, P.O. Box 117, Oak Ridge, Tennessee 37831, USA
| | | | - C Collins
- General Atomics, San Diego, California 92186-5608, USA
| | - A Lvovskiy
- Oak Ridge Associated Universities, P.O. Box 117, Oak Ridge, Tennessee 37831, USA
| | - R A Moyer
- University of California-San Diego, La Jolla, California 92093, USA
| | - M E Austin
- University of Texas, Austin, Texas 78705, USA
| | - D P Brennan
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - C Liu
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - E F Jaeger
- XCEL Engineering, Oak Ridge, Tennessee 37830, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Shurrab M, Kaoutskaia A, Baranchuk A, Lau C, Singarajah T, Lashevsky I, Newman D, Healey JS, Crystal E. Are there increased periprocedural complications with the MRI-conditional Medtronic Revo SureScan Pacing System? : A meta-analysis. Neth Heart J 2018; 26:233-239. [PMID: 29411288 PMCID: PMC5910305 DOI: 10.1007/s12471-018-1086-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The use of magnetic resonance imaging (MRI)-conditional permanent pacemakers has increased significantly. In this meta-analysis, we examine the safety of MRI-conditional pacing systems in comparison with conventional systems. METHODS An electronic search was performed using major databases, including studies that compared the outcomes of interest between patients receiving MRI-conditional pacemakers (MRI group) versus conventional pacemakers (control group). RESULTS Six studies (5 retrospective and 1 prospective non-randomised) involving 2,118 adult patients were identified. The MRI-conditional pacemakers, deployed in 969 patients, were all from a single manufacturer (Medtronic Pacing System with 5086 leads). The rate of pacemaker lead dislodgement (atrial and ventricular) was significantly higher in the MRI group (3% vs. 1%, OR 2.47 (95% CI 1.26; 4.83), p = 0.008). The MRI group had a significantly higher rate of pericardial complications (2% vs. 1%, OR 4.23 (95% CI 1.18; 15.10), p = 0.03) and a numerically higher overall complication rate in comparison with the conventional group (6% vs. 3%, OR 2.02 (95% CI 0.88; 4.66), p = 0.10) but this was not statistically significant. CONCLUSIONS In this meta-analysis, the rates of pacemaker lead dislodgement and pericardial complications were significantly higher with the Medtronic MRI-conditional pacing system.
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Affiliation(s)
- M Shurrab
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. .,Division of Cardiology, Women's College Hospital, University of Toronto, Toronto, Ontario, Canada. .,Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
| | - A Kaoutskaia
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - A Baranchuk
- Division of Cardiology, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada
| | - C Lau
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - T Singarajah
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - I Lashevsky
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - D Newman
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - J S Healey
- Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - E Crystal
- Arrhythmia Services, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Women's College Hospital, University of Toronto, Toronto, Ontario, Canada
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Wang G, Peebles WA, Doyle EJ, Crocker NA, Wannberg C, Lau C, Hanson GR, Doane JL. Evaluation of low-frequency operational limit of proposed ITER low-field-side reflectometer waveguide run including miter bends. Rev Sci Instrum 2017; 88:103508. [PMID: 29092526 DOI: 10.1063/1.4995662] [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] [Indexed: 06/07/2023]
Abstract
The present design concept for the ITER low-field-side reflectometer transmission line (TL) consists of an ∼40 m long, 6.35 cm diameter helically corrugated waveguide (WG) together with ten 90° miter bends. This paper presents an evaluation of the TL performance at low frequencies (33-50 GHz) where the predicted HE11 mode ohmic and mode conversion losses start to increase significantly. Quasi-optical techniques were used to form a near Gaussian beam to efficiently couple radiation in this frequency range into the WG. It was observed that the output beams from the guide remained linearly polarized with cross-polarization power levels of ∼1.5%-3%. The polarization rotation due to the helical corrugations was in the range ∼1°-3°. The radiated beam power profiles typically show excellent Gaussian propagation characteristics at distances >20 cm from the final exit aperture. The round trip propagation loss was found to be ∼2.5 dB at 50 GHz and ∼6.5 dB at 35 GHz, showing an inverse increase with frequency. This was consistent with updated calculations of miter bend and ohmic losses. At low frequencies (33-50 GHz), the mode purity remained very good at the exit of the waveguide, and the losses are perfectly acceptable for operation in ITER. The primary challenge may come from the future addition of a Gaussian telescope and other filter components within the corrugated guide, which will likely introduce additional perturbations to the beam profile and an increase in mode-conversion loss.
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Affiliation(s)
- G Wang
- Department of Physics and Astronomy and PSTI, UCLA, Los Angeles, California 90095, USA
| | - W A Peebles
- Department of Physics and Astronomy and PSTI, UCLA, Los Angeles, California 90095, USA
| | - E J Doyle
- Department of Physics and Astronomy and PSTI, UCLA, Los Angeles, California 90095, USA
| | - N A Crocker
- Department of Physics and Astronomy and PSTI, UCLA, Los Angeles, California 90095, USA
| | - C Wannberg
- Department of Physics and Astronomy and PSTI, UCLA, Los Angeles, California 90095, USA
| | - C Lau
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G R Hanson
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J L Doane
- General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA
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Kumar A, Lau C, Chan S, Ma M, Kearns W. A LONGITUDINAL STUDY OF THE NAVIGATION PATTERNS OF DEMENTIA PATIENTS AND THEIR RELATIONSHIP TO MMSE. Innov Aging 2017. [DOI: 10.1093/geroni/igx004.908] [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: 11/12/2022] Open
Affiliation(s)
- A. Kumar
- Joint NTU-UBC Research Centre of Excellence in Active Living for the Elderly, Singapore, Singapore,
- IGS, Nanyang Technological University, Singapore, Singapore,
| | - C. Lau
- SCSE, Nanyang Technological University, Singapore, Singapore,
| | - S. Chan
- College of Professional and Continuing Education, Singapore, Singapore,
| | - M. Ma
- EEE, Nanyang Technological University, Singapore, Singapore,
| | - W. Kearns
- University of South Florida, Tampa, Florida
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Huang L, Injac SG, Zhao H, Lin Q, Kogiso M, Man C, Li X, Lau C, Wong ST. P11.08 Systematic drug repurposing for faster cures of pediatric cancer identifies that Digoxin prolongs survival in a PDOX model of group 4 medulloblastoma. Neuro Oncol 2017. [DOI: 10.1093/neuonc/nox036.352] [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: 11/13/2022] Open
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Viswanathan S, Lau C, Akbari H, Hoyen C, Walsh MC. Survey and evidence based review of probiotics used in very low birth weight preterm infants within the United States. J Perinatol 2017; 37:104. [PMID: 28050019 DOI: 10.1038/jp.2016.181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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