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Marchand M, Erickson AC, Gillman L, Haywood R, Morrison J, Jaworsky D, Drouin O, Laksman Z, Krahn AD, Arbour L. The Impact of Chronic Disease on the Corrected QT (QTc) Value in Women in a British Columbia First Nations Population. Can J Cardiol 2024; 40:89-97. [PMID: 37852605 DOI: 10.1016/j.cjca.2023.10.007] [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: 03/06/2023] [Revised: 09/27/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023] Open
Abstract
BACKGROUND Indigenous women have higher rates of chronic disease than Indigenous men and non-Indigenous women. Long QT syndrome (LQTS) can be inherited or acquired; the latter may occur with chronic disease. A prolonged corrected QT value (QTc) is an independent risk factor for ventricular arrhythmias and sudden death, but few studies have quantified the impact of chronic disease on the QTc. We assessed the association between chronic disease and QTc prolongation in a population of First Nations women previously ascertained to study a high rate of inherited LQTS due to a unique genetic (founder) variant in their community. METHODS This substudy focusing on women expands on the original research where patients with clinical features of LQTS and their relatives were assessed for genetic variants discovered to affect the QTc. Medical records were retrospectively reviewed and chronic diseases documented. Using multivariate linear regression, adjusting for the effect of genetic variants, age, and QTc-prolonging medications, we evaluated the association between chronic disease and the QTc. RESULTS In total, 275 women were included. After adjustments, a prolonged QTc was associated with coronary artery disease (26.5 ms, 95% confidence interval [CI] 9.0-44.1 ms; P = 0.003), conduction system disease (26.8 ms, 95% CI 2.2-51.4 ms; P = 0.033), rheumatoid arthritis (28.9 ms, 95% CI 12.7-45.1 ms; P = 0.001), and type 2 diabetes mellitus (17.9 ms, 95% CI 3.6-32.3 ms; P = 0.015). CONCLUSIONS This quantification of the association between chronic disease and QTc prolongation in an Indigenous cohort provides insight into the nongenetic determinants of QTc prolongation. Corroboration in other populations will provide evidence for generalisability of these results.
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Affiliation(s)
- Miles Marchand
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Syilx Okanagan Nation, British Columbia, Canada
| | - Anders C Erickson
- Population and Public Health Division, British Columbia Ministry of Health, Victoria, British Columbia, Canada(‡)
| | - Lawrence Gillman
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada
| | - Rachel Haywood
- Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada
| | - Julie Morrison
- Community Member, Gitxsan Nation, British Columbia, Canada
| | - Denise Jaworsky
- Northern Health Authority, Terrace, British Columbia, Canada; Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Olivier Drouin
- Northern Health Authority, Terrace, British Columbia, Canada
| | - Zachary Laksman
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Arbour
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada; Community Genetics Research Program, University of British Columbia, Island Medical Program, Victoria, British Columbia, Canada.
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Smillie C, Haywood R, Donnellan C, Chu P. The use of technology to aid the formation of home parenteral nutrition contingency prescriptions. Clin Nutr ESPEN 2022. [PMCID: PMC8937548 DOI: 10.1016/j.clnesp.2022.02.078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Faderani R, Ali S, Masud D, Haywood R. 180 Improving Wall Access When Using Double Clamps for Microsurgical Anastomosis – A New Technique. Br J Surg 2021. [DOI: 10.1093/bjs/znab259.690] [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] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Microvascular techniques and instrumentation have continually evolved since the advent of clinical microsurgery in the 1970’s. These refinements and improved patient selection have led to increased vessel patency and flap survival rates. However, a fundamental principle which has not changed over this time period is comfort and proper operating microscope set-up. Both these factors were described as a precondition of microsurgical success by the late pioneer of microsurgery himself, Robert Acland. Suboptimal comfort or set-up can negatively impact on access to the surgical field leading to improper technique and if significant enough, anastomotic thrombosis. We describe a new technique aimed at improving wall access when using double clamps for microsurgical anastomosis.
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Affiliation(s)
- R Faderani
- Morriston hospital, Swansea, United Kingdom
| | - S Ali
- Welsh Centre for Burns and Plastic Surgery, Swansea, United Kingdom
| | - D Masud
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - R Haywood
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
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4
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Thompson AK, Carruth H, Haywood R, Hill NJ, Sarnacki WA, McCane LM, Wolpaw JR, McFarland DJ. Effects of Sensorimotor Rhythm Modulation on the Human Flexor Carpi Radialis H-Reflex. Front Neurosci 2018; 12:505. [PMID: 30090056 PMCID: PMC6068279 DOI: 10.3389/fnins.2018.00505] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/04/2018] [Indexed: 11/18/2022] Open
Abstract
People can learn over training sessions to increase or decrease sensorimotor rhythms (SMRs) in the electroencephalogram (EEG). Activity-dependent brain plasticity is thought to guide spinal plasticity during motor skill learning; thus, SMR training may affect spinal reflexes and thereby influence motor control. To test this hypothesis, we investigated the effects of learned mu (8–13 Hz) SMR modulation on the flexor carpi radialis (FCR) H-reflex in 6 subjects with no known neurological conditions and 2 subjects with chronic incomplete spinal cord injury (SCI). All subjects had learned and practiced over more than 10 < 30-min training sessions to increase (SMR-up trials) and decrease (SMR-down trials) mu-rhythm amplitude over the hand/arm area of left sensorimotor cortex with ≥80% accuracy. Right FCR H-reflexes were elicited at random times during SMR-up and SMR-down trials, and in between trials. SMR modulation affected H-reflex size. In all the neurologically normal subjects, the H-reflex was significantly larger [116% ± 6 (mean ± SE)] during SMR-up trials than between trials, and significantly smaller (92% ± 1) during SMR-down trials than between trials (p < 0.05 for both, paired t-test). One subject with SCI showed similar H-reflex size dependence (high for SMR-up trials, low for SMR-down trials): the other subject with SCI showed no dependence. These results support the hypothesis that SMR modulation has predictable effects on spinal reflex excitability in people who are neurologically normal; they also suggest that it might be used to enhance therapies that seek to improve functional recovery in some individuals with SCI or other CNS disorders.
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Affiliation(s)
- Aiko K Thompson
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, United States
| | - Hannah Carruth
- Division Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Haywood
- Division Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow, United Kingdom
| | - N Jeremy Hill
- Burke Neurological Institute, White Plains, NY, United States.,Blythedale Children's Hospital, Valhalla, NY, United States
| | - William A Sarnacki
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Lynn M McCane
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Jonathan R Wolpaw
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, NY, United States.,Albany Stratton VA Medical Center, Albany, NY, United States
| | - Dennis J McFarland
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health, Albany, NY, United States
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Chiang SC, Meagher M, Kassouf N, Hafezparast M, McKinnon PJ, Haywood R, El-Khamisy SF. Mitochondrial protein-linked DNA breaks perturb mitochondrial gene transcription and trigger free radical-induced DNA damage. Sci Adv 2017; 3:e1602506. [PMID: 28508041 PMCID: PMC5409496 DOI: 10.1126/sciadv.1602506] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 03/02/2017] [Indexed: 05/06/2023]
Abstract
Breakage of one strand of DNA is the most common form of DNA damage. Most damaged DNA termini require end-processing in preparation for ligation. The importance of this step is highlighted by the association of defects in the 3'-end processing enzyme tyrosyl DNA phosphodiesterase 1 (TDP1) and neurodegeneration and by the cytotoxic induction of protein-linked DNA breaks (PDBs) and oxidized nucleic acid intermediates during chemotherapy and radiotherapy. Although much is known about the repair of PDBs in the nucleus, little is known about this process in the mitochondria. We reveal that TDP1 resolves mitochondrial PDBs (mtPDBs), thereby promoting mitochondrial gene transcription. Overexpression of a toxic form of mitochondrial topoisomerase I (TOP1mt*), which generates excessive mtPDBs, results in a TDP1-dependent compensatory up-regulation of mitochondrial gene transcription. In the absence of TDP1, the imbalance in transcription of mitochondrial- and nuclear-encoded electron transport chain (ETC) subunits results in misassembly of ETC complex III. Bioenergetics profiling further reveals that TDP1 promotes oxidative phosphorylation under both basal and high energy demands. It is known that mitochondrial dysfunction results in free radical leakage and nuclear DNA damage; however, the detection of intermediates of radical damage to DNA is yet to be shown. Consequently, we report an increased accumulation of carbon-centered radicals in cells lacking TDP1, using electron spin resonance spectroscopy. Overexpression of the antioxidant enzyme superoxide dismutase 1 (SOD1) reduces carbon-centered adducts and protects TDP1-deficient cells from oxidative stress. Conversely, overexpression of the amyotrophic lateral sclerosis-associated mutant SOD1G93A leads to marked sensitivity. Whereas Tdp1 knockout mice develop normally, overexpression of SOD1G93A suggests early embryonic lethality. Together, our data show that TDP1 resolves mtPDBs, thereby regulating mitochondrial gene transcription and oxygen consumption by oxidative phosphorylation, thus conferring cellular protection against reactive oxygen species-induced damage.
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Affiliation(s)
- Shih-Chieh Chiang
- Krebs Institute and Sheffield Institute for Nucleic Acids, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, U.K
| | - Martin Meagher
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
| | - Nick Kassouf
- RAFT Institute, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, U.K
| | - Majid Hafezparast
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, U.K
| | - Peter J. McKinnon
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105–3678, USA
| | - Rachel Haywood
- RAFT Institute, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, U.K
| | - Sherif F. El-Khamisy
- Krebs Institute and Sheffield Institute for Nucleic Acids, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, U.K
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza 12588, Egypt
- Corresponding author.
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Snhah SS, Agarwal R, Haywood R. Atraumatic Flexor Tendon Retrieval: The Use of a Slip Knot. ACTA ACUST UNITED AC 2016; 31:580-1. [PMID: 16835004 DOI: 10.1016/j.jhsb.2006.05.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 05/22/2006] [Accepted: 05/26/2006] [Indexed: 11/28/2022]
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7
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O'Neill F, McLoughlin E, Riwanto M, Manz J, Adler A, Sutill E, Khan T, Haywood R, Kay CWM, D'Aiuto F, Charakida M, Landmesser U, Deanfield J. Reproducibility and biological variability of HDL's vascular functional assays. Atherosclerosis 2015; 241:588-94. [PMID: 26115070 DOI: 10.1016/j.atherosclerosis.2015.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 05/14/2015] [Accepted: 06/02/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent failures of clinical trials promoting HDL-elevating therapies have prompted research groups to focus on its functional activity in disease. Endothelial effects of HDL can be measured with in vitro cell assays. The reproducibility and biological relevance of these assays have not been explored both in healthy individuals and those at increased cardiovascular (CV) risk. METHODS HDL dependent nitric oxide (NO) bioavailability, superoxide (SO) production and serum paraoxonase-1 (PON-1) activity were measured in 35 healthy adults (34.37 24-49) and 8 patients (43.56 37-49) suffering from a chronic inflammatory condition (periodontitis-PD). Assay reproducibility was assessed by independent technicians on consecutive days to determine inter and intra analyser variability for each assay. The 35 healthy individuals were further divided into young (n = 16) and middle aged (n = 19) groups and compared with regards to HDL functions. Within-subject biological variation of HDL function was determined in a sub-group of 25 healthy volunteers at intervals of one day and 1 month, and in 8 patients at intervals of one day and 1 week. Power curves were also generated to estimate the number of patients that would be required for HDL functional assays in a cross-over and parallel study design. RESULTS NO bioavailability was the most reproducible assay in healthy adults (coefficient of variation = 1.72%, 1.92 - intra and inter respectively) and PD patients (CV = 4.4% and 5.5%). All measures demonstrated no statistical difference between young and healthy middle aged population. No single assay demonstrated significant variations over time, indicating that within patient variations are negligible. Our power curves for NO bioavailability and PON-1 activity suggest that low number of patients will be required to detect significant differences in HDL function in a cross over and parallel study design. CONCLUSION This study suggests that in vitro HDL functional assays are reliable and can be used to assess HDL functionality in healthy and diseased populations. NO bioavailability was the most reproducible assay, but PON-1 activity remains the most practical for application in clinical trials due to its capacity for scale.
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Affiliation(s)
- Francis O'Neill
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Eve McLoughlin
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Meliana Riwanto
- Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland
| | - Jasmin Manz
- Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland
| | - Andreas Adler
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Emma Sutill
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Tauseef Khan
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Rachel Haywood
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Christopher W M Kay
- Institute of Structural & Molecular Biology and London Centre for Nanotechnology, University College London, London, UK
| | - Francesco D'Aiuto
- Periodontology Unit, Department of Clinical Research, University College London Eastman Dental Institute, London, UK
| | - Marietta Charakida
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK
| | - Ulf Landmesser
- Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland
| | - John Deanfield
- Vascular Physiology Unit, Institute of Cardiovascular Science, University College London, London, UK; National Institute for Cardiovascular Outcomes Research, University College London, London, UK.
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Haywood R, Volkov A, Andrady C, Sayer R. Measuring sunscreen protection against solar-simulated radiation-induced structural radical damage to skin using ESR/spin trapping: Development of anex vivotest method. Free Radic Res 2012; 46:265-75. [DOI: 10.3109/10715762.2011.651719] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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9
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Haywood R, Andrady C, Kassouf N, Sheppard N. Intensity-dependent Direct Solar Radiation- and UVA-induced Radical Damage to Human Skin and DNA, Lipids and Proteins. Photochem Photobiol 2010; 87:117-30. [DOI: 10.1111/j.1751-1097.2010.00850.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [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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10
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Haywood R, Rogge F, Lee M. Protein, lipid, and DNA radicals to measure skin UVA damage and modulation by melanin. Free Radic Biol Med 2008; 44:990-1000. [PMID: 18160051 DOI: 10.1016/j.freeradbiomed.2007.11.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 11/14/2007] [Accepted: 11/21/2007] [Indexed: 01/22/2023]
Abstract
Afro-Caribbeans have a lower incidence of skin cancer than Caucasians, but the effectiveness of melanin as a photoprotective pigment is debated. We investigated the UVA and solar irradiation of ex vivo human skin and DMPO using electron spin resonance spectroscopy, to determine whether pigmented skin is protected by melanin against free radical damage. Initial ascorbate radicals in Caucasian skin were superseded by lipid and/or protein radical adducts with isotropic (a(H)=1.8 mT) and anisotropic spectra comparable to spectra in irradiated pig fat (a(H)=1.9 mT) and BSA. DNA carbon-centered radical adducts (a(H)=2.3 mT) and a broad singlet were detected in genomic DNA/melanin but were not distinguishable in irradiated Caucasian skin. Protein and lipid radicals (n=6 in Caucasian skin) were minimal in Afro-Caribbean skin (n=4) and intermediate skin pigmentations were variable (n=3). In irradiated Afro-Caribbean skin a shoulder to the melanin radical (also in UVA-irradiated pigmented melanoma cells and genomic DNA/melanin and intrinsic to pheomelanin) was detected. In this sample group, protein (but not lipid) radical adducts decreased directly with pigmentation. ESR/spin trapping methodology has potential for screening skin susceptibility to aging and cancer-related radical damage and for measuring protection afforded by melanin, sunscreens, and antiaging creams.
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Affiliation(s)
- Rachel Haywood
- RAFT Institute of Plastic Surgery, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, UK.
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11
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Haywood R. Solar radiation, carcinogenesis and radical damage: Measuring damage, susceptibility and improving protection. J Plast Reconstr Aesthet Surg 2007. [DOI: 10.1016/j.bjps.2007.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Haywood R. ESR/SPIN-trapping investigation of UV-induced radical production in human skin. J Plast Reconstr Aesthet Surg 2006. [DOI: 10.1016/j.bjps.2006.03.009] [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: 11/16/2022]
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13
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Haywood R. Relevance of Sunscreen Application Method, Visible Light and Sunlight Intensity to Free-radical Protection: A Study of ex vivo Human Skin. Photochem Photobiol 2006; 82:1123-31. [PMID: 17205635 DOI: 10.1562/2006-02-08-ra-799] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
With the continued rise in skin cancers worldwide there is a need for effective skin protection against sunlight damage. It was shown previously that sunscreens, which claimed UVA protection (SPF 20+), provided limited protection against UV-induced ascorbate radicals in human skin. Here the results of an electron spin resonance (ESR) investigation to irradiate ex vivo human skin with solar-simulated light are reported. The ascorbate radical signal in the majority of skin samples was directly proportional to the irradiance over relevant sunlight intensities (0.9-2.9 mW cm(-2)). Radical production (substratum-corneum) by UV (wavelengths < 400 nm) and visible components (> 400 nm) was approximately 67% and 33% respectively. Ascorbate radicals were in steady state concentration at low irradiance (approximately 1 mW cm(-2) equivalent to UK sunlight), but at higher irradiance (approximately 3 mW cm(-2)) decreased with time, suggesting ascorbate depletion. Radical protection by a four star-rated sunscreen (with UVA protection) was optimal when applied as a thin film (40-60% at 2 mg cm(-2)) but less so when rubbed into the skin (37% at 4 mg cm(-2) and no significant protection at 2 mg cm(-2)), possibly due to cream filling crevices, which reduced film thickness. This study validates ESR determinations of the ascorbate radical for quantitative protection measurements. Visible light contribution to radical production, and loss of protection when sunscreen is rubbed into skin, has implications for sunscreen design and use for the prevention of free-radical damage.
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Affiliation(s)
- Rachel Haywood
- RAFT Institute of Plastic Surgery, Mount Vernon Hospital, Northwood, Middlesex, UK.
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14
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Haywood R, Wardman P, Sanders R, Linge C. Sunscreens Inadequately Protect Against Ultraviolet-A-Induced Free Radicals in Skin: Implications for Skin Aging and Melanoma? J Invest Dermatol 2003; 121:862-8. [PMID: 14632206 DOI: 10.1046/j.1523-1747.2003.12498.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Sunscreens are employed to mitigate the adverse effects of sunlight on skin but are primarily designed to prevent ultraviolet-B-associated burning and damage. The increasingly recognized role of ultraviolet A in aging, and possibly melanoma, highlights the need to include ultraviolet A screens; however, validation remains difficult. We have used a novel method to establish the efficacy of sunscreens, by measuring ultraviolet-A-induced free-radical production (thought to contribute towards ultraviolet-A-related aging and malignant change). Electron spin resonance spectroscopy was used to detect free radicals directly in human Caucasian skin during irradiation with levels of ultraviolet comparable to solar intensities. Using this system the protection afforded by three high factor sunscreens (sun protection factor 20+) that claim ultraviolet A protection was examined. Each sunscreen behaved similarly: at recommended application levels (> or = 2 mg per cm2) the ultraviolet-induced free radicals were reduced by only about 55%, and by about 45% at 0.5-1.5 mg per cm (0.5 mg per cm2 reported for common usage). A "free-radical protection factor" calculated on the basis of these results was only 2 at the recommended application level, which contrasts strongly with the erythema-based sun protection factors (mainly indicative of ultraviolet B protection) quoted by the manufacturers (20+). The disparity between these protection factors suggests that prolonged sunbathing (encouraged by use of these creams) would disproportionately increase exposure to ultraviolet A and consequently the risk of ultraviolet-A-related skin damage.
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Affiliation(s)
- Rachel Haywood
- RAFT Institute of Plastic Surgery, Mount Vernon Hospital, Northwood, Middlesex, UK.
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15
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Clover J, Haywood R. New use for a prep sponge. Br J Plast Surg 2001; 54:182-3. [PMID: 11424283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
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16
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Clover J, Haywood R. New use for a prep sponge. Br J Plast Surg 2001; 54:182-183. [PMID: 11207142 DOI: 10.1054/bjps.2000.3492] [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] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- J. Clover
- Department of Plastic and Reconstructive Surgery, Nottingham City Hospital, Hucknall Road, Nottingham, NG5 1PB, UK
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Grootveld MC, Herz H, Haywood R, Hawkes GE, Naughton D, Perera A, Knappitt J, Blake DR, Claxson AW. Multicomponent analysis of radiolytic products in human body fluids using high field proton nuclear magnetic resonance (NMR) spectroscopy. Radiat Phys Chem Oxf Engl 1993 1994. [DOI: 10.1016/0969-806x(94)90060-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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Naughton DP, Haywood R, Blake DR, Edmonds S, Hawkes GE, Grootveld M. A comparative evaluation of the metabolic profiles of normal and inflammatory knee-joint synovial fluids by high resolution proton NMR spectroscopy. FEBS Lett 1993; 332:221-5. [PMID: 7691662 DOI: 10.1016/0014-5793(93)80636-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
High resolution 1H NMR spectroscopy has been employed to investigate the metabolic profile of healthy human knee-joint synovial fluid (SF) and the biochemical data acquired have been compared with those of matched serum, and inflammatory knee-joint SF samples. Results obtained indicate that the healthy human knee-joint has a hypoxic status (high lactate level when expressed relative to that of paired serum) that is milder than that of the inflamed human knee-joint. Moreover, normal SF differs from that of inflammatory SF in that it contains little or no NMR-detectable lipoprotein-associated fatty acids and 'acute-phase' glycoproteins, an observation reflecting the limited passage of these macromolecules from plasma into the synovial space in healthy subjects.
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Affiliation(s)
- D P Naughton
- Inflammation Research Group, London Hospital Medical College, UK
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Randell CP, Collins AG, Young IR, Haywood R, Thomas DJ, McDonnell MJ, Orr JS, Bydder GM, Steiner RE. Nuclear magnetic resonance imaging of posterior fossa tumors. AJR Am J Roentgenol 1983; 141:489-96. [PMID: 6603757 DOI: 10.2214/ajr.141.3.489] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The results of nuclear magnetic resonance (NMR) examinations in 26 patients with histologic (15 cases) or clinical (11 cases) diagnoses of tumors within the posterior fossa were reviewed and compared with x-ray computed tomography (CT). Most tumors displayed an increase in T1 and T2 relative to brain. All seven benign tumors were seen with both CT and NMR, although one of these cases initially was misdiagnosed on the basis of the CT findings. The extent of these tumors was equally well shown with CT and NMR in three cases but was demonstrated better by NMR in four. Calcification was seen with CT but not with NMR in two of these patients. All 19 malignant tumors were demonstrated with NMR. Two of these were not seen with CT. In 12 patients minimal changes consisting of a poorly defined low-attenuation are or minor displacement of the fourth ventricle were noted with CT, although much more extensive changes were seen with NMR. In three patients the changes were equally well shown with both techniques. In the remaining two cases, the extent of the tumor was defined more accurately with contrast-enhanced CT, where the margin between tumor and surrounding edema was better seen than with NMR. Mass effects were better demonstrated with NMR in 13 patients and equally well shown in six. Bony erosion was better demonstrated with CT in two cases. Hydrocephalus with periventricular edema was seen in five patients; in each it was more clearly demonstrated with NMR. The NMR diagnosis of tumors is discussed and relevant new developments are summarized.
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Haywood R. Extraction of a Large Stone by the Lateral Operation. Med Exam (Phila) 1847; 3:85-86. [PMID: 38120477 PMCID: PMC10287271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
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