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Orlando G, Bubbear J, Clarke S, Keen R, Roy M, Anilkumar A, Schini M, Walsh JS, Javaid MK, Ireland A. Physical function and physical activity in adults with X-linked hypophosphatemia. Osteoporos Int 2022; 33:1485-1491. [PMID: 35122145 DOI: 10.1007/s00198-022-06318-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/20/2022] [Indexed: 12/17/2022]
Abstract
UNLABELLED We described physical function and activity in UK adults with X-linked hypophosphatemia (XLH). Our data indicate that low physical activity and impaired mobility are common in adults with XLH. Deficits in lower limbs muscle power and functional capacity contribute to the loss of physical function in adults with XLH. INTRODUCTION There is a dearth of literature on physical function and physical activity in adults with X-linked hypophosphatemia (XLH). We described muscle strength and power, functional capacity, mobility and physical activity level and explored the relationships among these variables in adults with XLH. METHODS Participants were recruited as part of a UK-based prospective cohort study, the RUDY Study. They underwent a clinical visit and physical examination, including assessment of handgrip strength, jump power (mechanography), six-minute walk test (6MWT) and short physical performance battery (SPPB), and completed the International Physical Activity Questionnaire (IPAQ). Performance data were analysed using parametric and non-parametric tests, whereas correlations were assessed by univariate analysis. RESULTS Twenty-six adults with XLH (50% males) with a mean age of 44 ± 16.1 years were recruited. Jump power and 6MWT distances (p < 0.0001) were 54.4% and 38.6% lower respectively in individuals with XLH compared with normative values. These deficits were not associated with age or sex. Handgrip strength values were similar to expected values. Deficits in muscle power were more pronounced than those reported at 6MWT (p < 0.0001). Univariate analysis revealed only a correlation between total physical activity and muscle power (r = 0.545, p = 0.019). CONCLUSIONS Adults with XLH have a marked deficit in lower limb muscle power and a reduced functional capacity, with a high incidence of impaired mobility and inactivity. In addition to metabolic effects of XLH, low physical activity may contribute to deficits in lower limb power. Further studies are required to develop novel treatment approaches to improve physical function and mobility.
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Affiliation(s)
- G Orlando
- Research Centre for Musculoskeletal Science & Sports Medicine, Department of Life Sciences, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD, UK.
| | - J Bubbear
- Rheumatology & Metabolic Bone Unit, Royal National Orthopaedic Hospital, Stanmore, UK
| | - S Clarke
- Department of Rheumatology, University Hospitals Bristol, Bristol, UK
| | - R Keen
- Rheumatology & Metabolic Bone Unit, Royal National Orthopaedic Hospital, Stanmore, UK
| | - M Roy
- Department of Rheumatology, University Hospitals Bristol, Bristol, UK
| | - A Anilkumar
- Department of Rheumatology, University Hospitals Bristol, Bristol, UK
| | - M Schini
- Academic Unit of Bone Metabolism, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - J S Walsh
- Academic Unit of Bone Metabolism, Department of Oncology and Metabolism, University of Sheffield, Sheffield, UK
| | - M K Javaid
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford NIHR Musculoskeletal Biomedical Research Unit, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - A Ireland
- Research Centre for Musculoskeletal Science & Sports Medicine, Department of Life Sciences, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD, UK
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Quinlivan R, Messer B, Murphy P, Astin R, Mukherjee R, Khan J, Emmanuel A, Wong S, Kulshresha R, Willis T, Pattni J, Willis D, Morgan A, Savvatis K, Keen R, Bourke J, Marini Bettolo C, Hewamadduma C. Adult North Star Network (ANSN): Consensus Guideline For The Standard Of Care Of Adults With Duchenne Muscular Dystrophy. J Neuromuscul Dis 2021; 8:899-926. [PMID: 34511509 PMCID: PMC8673515 DOI: 10.3233/jnd-200609] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [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] [Indexed: 12/28/2022]
Abstract
There are growing numbers of adults with Duchenne Muscular Dystrophy living well into their fourth decade. These patients have complex medical needs that to date have not been addressed in the International standards of care. We sought to create a consensus based standard of care through a series of multi-disciplinary workshops with specialists from a wide range of clinical areas: Neurology, Cardiology, Respiratory Medicine, Gastroenterology, Endocrinology, Palliative Care Medicine, Rehabilitation, Renal, Anaesthetics and Clinical Psychology. Detailed reports of evidence reviewed and the consensus building process were produced following each workshop and condensed into this final document which was approved by all members of the Adult North Star Network including service users. The aim of this document is to provide a framework to improve clinical services and multi-disciplinary care for adults living with Duchenne Muscular Dystrophy.
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Affiliation(s)
- R. Quinlivan
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - B. Messer
- Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | - P. Murphy
- Lane Fox Unit, Guy’s and St Thomas’ Foundation Trust, London, UK
| | - R. Astin
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - R. Mukherjee
- Heart of England NHS Foundation Trust, Birmingham, UK
| | - J. Khan
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - A. Emmanuel
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - S.C. Wong
- University of Glasgow, Royal Hospital for Children, Glasgow, UK
| | - R. Kulshresha
- Robert Jones and Agnes Hunt Foundation NHS Trust, Oswestry, UK
| | - T. Willis
- Robert Jones and Agnes Hunt Foundation NHS Trust, Oswestry, UK
| | - J. Pattni
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - D. Willis
- Shrewsbury and Telford NHS Trust, Shropshire, UK
| | - A. Morgan
- South West Neuromuscular Operational Delivery Network, Bristol, UK
| | - K. Savvatis
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
- St Bartholomew’s Hospital and Royal London NHS Trust, London UK
| | - R. Keen
- Royal National Orthopaedic Hospital, Stanmore, UK
| | - J. Bourke
- Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle, UK
| | | | - C. Hewamadduma
- Academic Neurology Department, Sheffield Teaching Hospitals Foundation Trust and Sheffield Institute for Translational Neurosciences (SITRAN), University of Sheffield, Sheffield, UK
| | - on behalf of the ANSN
- MRC Centre for Neuromuscular Disease, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
- Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle, UK
- Lane Fox Unit, Guy’s and St Thomas’ Foundation Trust, London, UK
- Heart of England NHS Foundation Trust, Birmingham, UK
- University of Glasgow, Royal Hospital for Children, Glasgow, UK
- Robert Jones and Agnes Hunt Foundation NHS Trust, Oswestry, UK
- Shrewsbury and Telford NHS Trust, Shropshire, UK
- South West Neuromuscular Operational Delivery Network, Bristol, UK
- St Bartholomew’s Hospital and Royal London NHS Trust, London UK
- Royal National Orthopaedic Hospital, Stanmore, UK
- Academic Neurology Department, Sheffield Teaching Hospitals Foundation Trust and Sheffield Institute for Translational Neurosciences (SITRAN), University of Sheffield, Sheffield, UK
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Seefried L, Smyth M, Keen R, Harvengt P. Burden of disease associated with X-linked hypophosphataemia in adults: a systematic literature review. Osteoporos Int 2021; 32:7-22. [PMID: 32710160 PMCID: PMC7755619 DOI: 10.1007/s00198-020-05548-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 03/03/2020] [Accepted: 07/08/2020] [Indexed: 12/30/2022]
Abstract
UNLABELLED This systematic review collated evidence on the burden of XLH in adults. Data captured highlight the substantial ongoing burden of XLH in adulthood and identified unmet needs. Greater awareness and understanding of the impact of XLH in adulthood are needed to improve care and outcomes in adults with XLH. INTRODUCTION X-linked hypophosphataemia (XLH) is a rare metabolic bone disease characterized by renal phosphate wasting and musculoskeletal manifestations. Whilst the disease's impact in children is well documented, information on the effects of this progressive, debilitating condition on adults is lacking. This systematic review aimed to collate existing evidence on the burden of XLH in adulthood to identify unmet needs. METHODS MEDLINE, Embase and Cochrane Library databases and recent congress reports were searched on 19 February 2019 for English-language publications describing the medical, humanistic and socio-economic impact of XLH in adults (≥ 18 years old). In addition, a structured Internet search was conducted. RESULTS Of the 2351 articles identified, 91 met the selection criteria along with 44 congress abstracts. Data show that adults with XLH experience a range of clinical manifestations, particularly skeletal deformities and (pseudo)fractures, along with pain, dental abnormalities and impaired physical function and mobility. XLH in adulthood impacts on quality of life and places limitations on daily activities. The level of healthcare resource utilization among adults with XLH is indicative of substantial socio-economic burden; further research is needed to quantitate the economic impact on the healthcare system, society and patients. Adults with XLH may not receive appropriate care and treatment; a possible explanation for this is a lack of awareness among healthcare professionals. CONCLUSION XLH in adults is associated with considerable disease burden and unmet needs. Forthcoming studies and increased awareness of the impact of XLH in adulthood should help to improve management of XLH in adulthood and patient outcomes.
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Affiliation(s)
- L Seefried
- Orthopedic Institute, König-Ludwig Haus, University of Würzburg, Würzburg, Germany
| | - M Smyth
- Kyowa Kirin International, Galashiels, UK
| | - R Keen
- Royal National Orthopaedic Hospital, Stanmore, UK
| | - P Harvengt
- RVRH-XLH, French association of patients with XLH (a member of the International XLH Alliance), 20 rue Merlin de Thionville, Appt 120, 92150, Suresnes, France.
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McCarthy ID, Bloomer Z, Gall A, Keen R, Ferguson-Pell M. Changes in the structural and material properties of the tibia in patients with spinal cord injury. Spinal Cord 2011; 50:333-7. [PMID: 22124349 DOI: 10.1038/sc.2011.143] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
STUDY DESIGN A cross-sectional study. OBJECTIVES To measure the change of structural and material properties at different sites of the tibia in spinal cord-injured patients using peripheral quantitative computerised tomography (pQCT). SETTING Orthopaedic research centre (UK). METHODS Thirty-one subjects were measured--eight with acute spinal cord injury (SCI), nine with chronic SCI and fourteen able-bodied controls. pQCT scans were performed at 2% (proximal), 34% (diaphyseal) and 96% (distal) along the tibia from the tibial plateau. Structural measures of bone were calculated, and volumetric bone mineral density (vBMD) was also measured at all three levels. Muscle cross-sectional area was measured at the diaphyseal level. RESULTS Structurally, there were changes in the cortical bone; in the diaphysis, the shape of the cross-section changed to offer less resistance to AP bending, and the cross-sectional area of the cortical shell decreased both proximally and distally. There were corresponding changes in vBMD in the anterior aspect of the cortical diaphysis, as well as proximal and distal trabecular bone. Changes in muscle occurred more rapidly than changes in bone. CONCLUSION There were clear changes of both structure and material at all three levels of the tibia in chronic SCI patients. These changes were consistent with specific adaptations to reduced local mechanical loading conditions. To assess fracture risk in SCI and also to monitor the effect of therapeutic interventions, the structure of the bone should be considered in addition to trabecular bone mineral density.
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Affiliation(s)
- I D McCarthy
- UCL Institute of Orthopaedics and Musculoskeletal Science, Stanmore, UK.
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Panoutsopoulou K, Southam L, Elliott KS, Wrayner N, Zhai G, Beazley C, Thorleifsson G, Arden NK, Carr A, Chapman K, Deloukas P, Doherty M, McCaskie A, Ollier WER, Ralston SH, Spector TD, Valdes AM, Wallis GA, Wilkinson JM, Arden E, Battley K, Blackburn H, Blanco FJ, Bumpstead S, Cupples LA, Day-Williams AG, Dixon K, Doherty SA, Esko T, Evangelou E, Felson D, Gomez-Reino JJ, Gonzalez A, Gordon A, Gwilliam R, Halldorsson BV, Hauksson VB, Hofman A, Hunt SE, Ioannidis JPA, Ingvarsson T, Jonsdottir I, Jonsson H, Keen R, Kerkhof HJM, Kloppenburg MG, Koller N, Lakenberg N, Lane NE, Lee AT, Metspalu A, Meulenbelt I, Nevitt MC, O'Neill F, Parimi N, Potter SC, Rego-Perez I, Riancho JA, Sherburn K, Slagboom PE, Stefansson K, Styrkarsdottir U, Sumillera M, Swift D, Thorsteinsdottir U, Tsezou A, Uitterlinden AG, van Meurs JBJ, Watkins B, Wheeler M, Mitchell S, Zhu Y, Zmuda JM, Zeggini E, Loughlin J. Insights into the genetic architecture of osteoarthritis from stage 1 of the arcOGEN study. Ann Rheum Dis 2010; 70:864-7. [PMID: 21177295 PMCID: PMC3070286 DOI: 10.1136/ard.2010.141473] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [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] [Indexed: 12/21/2022]
Abstract
Objectives The genetic aetiology of osteoarthritis has not yet been elucidated. To enable a well-powered genome-wide association study (GWAS) for osteoarthritis, the authors have formed the arcOGEN Consortium, a UK-wide collaborative effort aiming to scan genome-wide over 7500 osteoarthritis cases in a two-stage genome-wide association scan. Here the authors report the findings of the stage 1 interim analysis. Methods The authors have performed a genome-wide association scan for knee and hip osteoarthritis in 3177 cases and 4894 population-based controls from the UK. Replication of promising signals was carried out in silico in five further scans (44 449 individuals), and de novo in 14 534 independent samples, all of European descent. Results None of the association signals the authors identified reach genome-wide levels of statistical significance, therefore stressing the need for corroboration in sample sets of a larger size. Application of analytical approaches to examine the allelic architecture of disease to the stage 1 genome-wide association scan data suggests that osteoarthritis is a highly polygenic disease with multiple risk variants conferring small effects. Conclusions Identifying loci conferring susceptibility to osteoarthritis will require large-scale sample sizes and well-defined phenotypes to minimise heterogeneity.
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Roemer FW, Kassim Javaid M, Guermazi A, Thomas M, Kiran A, Keen R, King L, Arden NK. Anatomical distribution of synovitis in knee osteoarthritis and its association with joint effusion assessed on non-enhanced and contrast-enhanced MRI. Osteoarthritis Cartilage 2010; 18:1269-74. [PMID: 20691796 DOI: 10.1016/j.joca.2010.07.008] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [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] [Received: 12/17/2009] [Revised: 06/07/2010] [Accepted: 07/20/2010] [Indexed: 02/02/2023]
Abstract
PURPOSE To describe the anatomical distribution of synovitis and its association with joint effusion on non-enhanced and contrast-enhanced (CE) MRI in patients with knee osteoarthritis (OA). METHODS Baseline MRI was performed at 1.5T using axial proton density (PD)-weighted (w) fat suppressed (fs) and axial and sagittal T1-w fs CE sequences. Synovial enhancement was scored in nine articular subregions. Maximum synovial enhancement was grouped as absent (0), equivocal (1) and definite (2 and 3). Effusion was scored from 0 to 3 on the axial sequences. We described the anatomical distribution of synovitis, its association with effusion and compared assessment of effusion on T1-w fs CE and PD fs sequences. RESULTS 111 subjects were included and examined by MRI. 89.2% of knees exhibited at least one subregion with a minimum grade 2 and 39.6% at the maximum of a grade 3. The commonest sites for definite synovitis were posterior to the posterior cruciate ligament (PCL) in 71.2% and in the suprapatellar region in 59.5% of all knees. On T1-w fs CE, 73.0% of knees showed any effusion. Definite synovitis in at least one location was present in 96.3% knees with an effusion and in 70.0% without an effusion. Higher grades of effusion were scored on the PD fs sequence. CONCLUSION Definite synovitis was present in the majority of knees with or without effusion with the commonest sites being posterior to the PCL and in the suprapatellar recess. Joint effusion as measured on PD fs images does not only represent effusion but also synovial thickening.
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Affiliation(s)
- F W Roemer
- Quantitative Imaging Center (QIC), Department of Radiology, Boston University Medical Center, Boston, MA 02118, USA.
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El Miedany Y, El Gaafary M, Youssef S, Toth M, Weightman J, Kelly M, Johnston E, Stone A, Harrison P, Bartholomew P, Kelly C, Vagadia V, Tuck S, Al-Shakarchi I, Louise Dolan A, Bridges MJ, Ruddick S, Bracewell C, Wright D, Aspray T, Hynes GM, Jameson K, Aihie Sayer A, Cooper C, Dennison E, Robinson S, Tull TJ, Fisher BA, Jenabzadeh R, Cobb JP, Abraham S, Hynes GM, Jameson K, Harvey N, Aihie Sayer A, Cooper C, Dennison E, Cheah J, Stacpoole S, Heaney D, Duncan J, Roshandel D, Holliday K, Pye SR, Boonen S, Borghs H, Vanderschueren D, Adams JE, Ward KA, Finn JD, Huhtaniemi IT, Silman AJ, Wu FC, Thomson W, O'Neill TW, White S, Shaw S, Short C, Gilleece Y, Fisher M, Walker-Bone K, Narshi CB, Martin R, Mitchell K, Keen R, Bridges MJ, Ruddick S, El Miedany Y, Toth M, Youssef S, El Gaafary M, Alhambra DP, Azagra R, Duro GE, Aguye A, Zwart M, Javaid KM. Osteoporosis and Metabolic Bone Disease [127-142]: 127. Osteoporosis, Falls and Fractures: Three Confounders in One Equation. Development and Validity of a New form for Assessment of Patients Referred for Dxa Scanning. Rheumatology (Oxford) 2010. [DOI: 10.1093/rheumatology/keq723] [Citation(s) in RCA: 3] [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: 12/25/2022] Open
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Reid DM, Mackay I, Wilkinson S, Miller C, Schuette DG, Compston J, Cooper C, Duncan E, Galwey N, Keen R, Langdahl B, McLellan A, Pols H, Uitterlinden A, O'Riordan J, Wass JAH, Ralston SH, Bennett ST. Cross-calibration of dual-energy X-ray densitometers for a large, multi-center genetic study of osteoporosis. Osteoporos Int 2006; 17:125-32. [PMID: 16136277 DOI: 10.1007/s00198-005-1936-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Accepted: 04/18/2005] [Indexed: 11/25/2022]
Abstract
Osteoporosis is a common disease with a strong genetic component characterized by reduced bone mass and an increased risk of fragility fractures. Bone mineral density (BMD) is the most important determinant of osteoporotic fracture risk, but the genes responsible for BMD regulation and fracture are incompletely defined. To enable multi-center studies to examine the genetic influences on BMD there is a requirement to standardize measurements across different manufacturers of bone densitometers, different versions of machines and different normative ranges. This paper describes a method developed to allow near-identical subjects with low age-adjusted BMD (based on Z-scores) to be recruited in 17 centers using 27 different densitometers. Cross-calibration was based on measurements using a European spine phantom circulated to all centers and measured ten times on each individual machine. From theses values an individual exponential curve, based on nominal versus observed BMD, was derived for each machine. As expected, there were large and significant variations in nominal BMD values, not only between scanners from different manufacturers but also between different versions of scanners from the same manufacturer. Hologic scanners tended to underestimate the nominal BMD, while Lunar scanners overestimated the value. Norland scanners gave mixed values over estimating BMD at the lower nominal value (0.5 g/cm2) while underestimating the value at the higher value (1.5 g/cm2). The validity of the exponential equations was tested using hip and spine measurements on 991 non-proband women from a familial osteoporosis study (FAMOS). After cross-calibration there was a considerable reduction in variation between machines. This observation, coupled with the absence of a similar reduction in variation attributable to a linear regression on age, demonstrated the validity of the cross-calibration approach. Use of the cross-calibration curves along with a standard normative range (in the case of this study, the Hologic normative range) allowed age-specific Z-scores to be used as an inclusion criterion in this genetic study, a method that will be useful for other trials where age-specific BMD inclusion criteria are required.
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Affiliation(s)
- D M Reid
- Department of Medicine and Therapeutics, Medical School, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
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Patel S, Dolan AL, Hajela V, Cheung N, Keen R. Does giving osteoporosis patient information to women who have had a fracture improve access to health care? Rheumatology (Oxford) 2004; 43:387-9. [PMID: 14963206 DOI: 10.1093/rheumatology/keh047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Moss K, Keen R. Usefulness of bone densitometry in postmenopausal women with clinically diagnosed vertebral fractures. Ann Rheum Dis 2002; 61:667-8; author reply 668. [PMID: 12079924 PMCID: PMC1754151 DOI: 10.1136/ard.61.7.667-a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Hunter D, Major P, Arden N, Swaminathan R, Andrew T, MacGregor AJ, Keen R, Snieder H, Spector TD. A randomized controlled trial of vitamin D supplementation on preventing postmenopausal bone loss and modifying bone metabolism using identical twin pairs. J Bone Miner Res 2000; 15:2276-83. [PMID: 11092410 DOI: 10.1359/jbmr.2000.15.11.2276] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vitamin D supplementation, when given with calcium, has been shown to increase bone mineral density (BMD) and reduce the incidence of hip fracture in elderly subjects. Despite its widespread use, the benefits of vitamin D supplementation in younger women and as a single agent are less clear. We performed a randomized co-twin, placebo-controlled, double-blind trial over 2 years to measure the effect of vitamin D3 supplementation on bone density and bone metabolism in young postmenopausal women. Seventy-nine monozygotic (MZ) twin pairs (mean age, 58.7 years; range, 47-70 years) were recruited. For each twin pair, one was randomized to 800 IU cholecalciferol/day for 2 years and the other was randomized to placebo. BMD was measured at the spine and hip and heel ultrasound at baseline, 12, 18, and 24 months. Samples were collected at 0, 3, and 6 months to measure serum calcium, 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), osteocalcin, and urinary deoxypyridinoline (DPD). In total, 64 pairs completed the study. No differences in baseline characteristics were seen between the groups. At 6 months, the treatment group had an increase in serum vitamin D [mean +/- SEM intrapair difference, 14.1+/-2.4 microg/liter (p < 0.001)]. There were no significant differences in other serum measurements or bone markers at 3 months or 6 months. At 24 months, no significant treatment effect was seen on BMD or calcaneal ultrasound change within pairs. Subanalysis of treatment response by vitamin D receptor (VDR) genotype revealed no significant difference in effect on BMD variables with treatment. On the basis of these results, vitamin D supplementation, on its own, cannot be recommended routinely as an osteoporosis prevention for healthy postmenopausal women with normal vitamin D levels under the age of 70 years.
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Affiliation(s)
- D Hunter
- Twin Research and Genetic Epidemiology Unit, St. Thomas' Hospital, London, United Kingdom
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Abstract
This study examined how pigeons discriminate the relative frequencies of events when the events occur serially. In a discrete-trials procedure, 6 pigeons were shown one light nf times and then another nl times. Next, they received food for choosing the light that had occurred the least number of times during the sample. At issue were (a) how the discrimination was related to two variables, the difference between the frequencies of the two lights, D = nf - nl, and the total number of lights in the sample, T = nf + nl; and (b) whether a simple mathematical model of the discrimination process could account for the data. In contrast with models that assume that pigeons count the stimulus lights, engage in mental arithmetic on numerons, or remember the number of stimuli, the present model assumed only that the influence of a sample stimulus on choice increases linearly when the stimulus is presented, but decays exponentially when the stimulus is absent. The results showed that, overall, the pigeons discriminated the relative frequencies well. Their accuracy always increased with the absolute value of the difference D and, for D > 0, it decreased with T. Performance also showed clear recency, primacy, and contextual effects. The model accounted well for the major trends in the data.
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Affiliation(s)
- R Keen
- Department of Psychology, Indiana University, Bloomington 47405, USA.
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Spector TD, Snieder H, Keen R, Lewis C, MacGregor A. Interpreting the results of a segregation analysis of generalized radiographic osteoarthritis: comment on the article by Felson et al. Arthritis Rheum 1999; 42:1068-70. [PMID: 10323471 DOI: 10.1002/1529-0131(199905)42:5<1068::aid-anr34>3.0.co;2-l] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wyns W, Schwaiger M, Huang SC, Buxton DB, Hansen H, Selin C, Keen R, Phelps ME, Schelbert HR. Effects of inhibition of fatty acid oxidation on myocardial kinetics of 11C-labeled palmitate. Circ Res 1989; 65:1787-97. [PMID: 2684448 DOI: 10.1161/01.res.65.6.1787] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effects of glucose and lactate infusion on palmitate oxidation were compared with the effect of 2-tetradecylglycidic acid (TDGA), an irreversible inhibitor of the carnitine acyltransferase I, in normoxic canine myocardium. The initial capillary transit retention fraction of [1-11C]palmitate and its fractional distribution between oxidation and esterification in myocardium were measured by the residue detection method after intracoronary tracer injection, as well as by effluent measurements of 11CO2, the end product of palmitate oxidation. TDGA reduced the initial capillary transit retention fraction (from 56 +/- 13% to 37 +/- 6%; p less than 0.001) and oxidation of palmitate (n = 19), as also evidenced by the decrease in the fraction of tracer released as 11CO2 from 28 +/- 5% to 6 +/- 3% (p less than 0.001). Infusion of carbohydrate (glucose or lactate; n = 6) reduced 11CO2 production from 30 +/- 7% to 7 +/- 4% (p less than 0.05) but did not alter the initial capillary transit retention fraction of tracer (59 +/- 5% vs. 56 +/- 10%; NS). The latter was due to increased esterification into neutral lipids (41 +/- 11% of injected palmitate after carbohydrate infusion versus 21 +/- 12% in control conditions), as measured from multiexponential curve fittings. When carbohydrates were given after inhibition of palmitate oxidation by TDGA (n = 7), the 11C tissue clearance kinetics were strikingly similar to those observed after carbohydrate infusion alone. Thus, enhanced metabolic trapping of [1-11C]palmitate in myocardium resulted in initial capillary transit retention fractions that were not different from control conditions (41 +/- 5% vs. 48 +/- 12%; NS) despite inhibition of oxidation. The results show that the intracellular metabolism of palmitate contributes to the control of its uptake by myocardium. The findings are consistent with inhibition of palmitate oxidation by carbohydrates occurring at the same site as TDGA.
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Affiliation(s)
- W Wyns
- Division of Nuclear Medicine and Biophysics, UCLA School of Medicine 90024
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Abstract
An ordinary desk-top microcomputer was programmed to simulate MR images for specified spin-echo pulse sequences. Model pixel maps of proton density and T1 and T2 relaxation times were made from published estimated values for regions of the human head, neck, and spine. Images were generated and displayed from the model maps and user-specified pulse-sequence parameters in less than 30 sec/image. Models for various pathologic conditions, including calcification, subacute hemorrhage, porencephaly, lipoma, and multiple sclerosis, were superimposed on the images of normal anatomy to create unknown cases. Simulated images can easily demonstrate the effect of pulse-sequence selection on the contrast of normal structures and pathologic conditions. Use of simulated images is an excellent technique for gaining experience in pulse-sequence selection. Low-cost microcomputers can provide adequate image detail and reasonable image display time of synthetic MR images for teaching purposes.
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Schwaiger M, Schelbert HR, Keen R, Vinten-Johansen J, Hansen H, Selin C, Barrio J, Huang SC, Phelps ME. Retention and clearance of C-11 palmitic acid in ischemic and reperfused canine myocardium. J Am Coll Cardiol 1985; 6:311-20. [PMID: 4019919 DOI: 10.1016/s0735-1097(85)80166-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Free fatty acids are the major energy source for cardiac muscle. Oxidation of fatty acid decreases or even ceases during ischemia. Its recovery after transient ischemia remains largely unexplored. Using intracoronary carbon-11 palmitic acid as a tracer of myocardial fatty acid metabolism in an open chest dog model, retention and clearance of tracer in myocardium were evaluated at control, during ischemia and after reperfusion following a 20 minute occlusion of the left anterior descending coronary artery. Myocardial C-11 time-activity curves were analyzed with biexponential curve-fitting routines yielding fractional distribution and clearance half-times of C-11 palmitic acid in myocardial tissue. In animals with permanent occlusion and intracoronary injection of C-11 palmitic acid distal to the occlusion site, the relative size and half-time of the early clearance curve component differed markedly from control values and did not change with ongoing ischemia. Conversely, in animals with only 20 minutes of coronary occlusion, the relative size of the early C-11 clearance phase was still significantly depressed at 20 and 90 minutes of reperfusion but returned to control level at 180 minutes. Tissue C-11 clearance half-times remained significantly prolonged throughout the reperfusion period. Regional function in reperfused myocardium monitored with ultrasonic crystals recovered slowly and was still less than control after 3 hours of reperfusion. The data indicate that after transient ischemia, myocardial fatty acid metabolism fails to recover immediately. Because the metabolic recovery occurs in parallel with recovery of regional function, C-11 palmitic acid in conjunction with positron tomography may be useful for studying regional fatty acid metabolism noninvasively after an ischemic injury, and may be helpful in identifying reversible tissue injury.
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Keen R, Filardo T, Colgan A. History and physical examination by oral and maxillofacial surgeons: the development of a physical assessment course. J Am Dent Assoc 1985; 110:64-6. [PMID: 3855923 DOI: 10.14219/jada.archive.1985.0286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Qualified oral surgeons may be granted hospital privileges to perform history and physical examinations on their patients as a result of a JCAH policy change, which became effective in January 1982. Oral surgeons must apply for and be granted this privilege from their affiliate hospitals and must demonstrate their qualifications. Various criteria can be used to assess qualification, including a review of the applicant's training in physical diagnosis in residency training, and participation in physical assessment continuing education programs. Review courses that feature hands-on practice are useful to oral surgeons interested in updating and refining their skills. Since the University of Illinois began offering a review course in 1981, 91 oral surgeons have completed the 2-day intensive review program. A follow-up survey of the participants indicates that the oral surgeons are applying for medical staff privileges. In a survey of 30 oral surgeons who participated in the course during 1982, 13 (43%) indicated that they had obtained the privilege to perform histories and physical examinations from their local hospitals.
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Eross J, Kreutzmann D, Jimenez M, Keen R, Rogers S, Cowell C, Vines R, Silink M. Colorimetric measurement of glycosylated protein in whole blood, red blood cells, plasma and dried blood. Ann Clin Biochem 1984; 21 ( Pt 6):477-83. [PMID: 6517486 DOI: 10.1177/000456328402100606] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A colorimetric method for the measurement of whole-blood glycosylation (WBG), glycosylated haemoglobin in red blood cells (GHb), glycosylated plasma protein (GPP) and dried-blood glycosylation (DBG) is described which is rapid, inexpensive and precise. GHb correlated well with HbA1 measured by cation-exchange chromatography and was also correlated with WBG, DBG and GPP. DBG, which showed good correlation with GHb, could be measured on several drops of blood dried on filter paper treated with glucose oxidase. Filter papers are posted to the laboratory prior to clinic visits, and by having the DBG result available more rational diabetic management is possible. For DBG, the intra- and inter-assay coefficient of variation at three levels is less than 6%. Reference values in non-diabetic children have been calculated and are compared with values obtained in 'good' clinical diabetic control and in 'fair' control. The filter-paper assay DBG method has a high degree of patient acceptance.
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Schelbert HR, Henze E, Keen R, Schon HR, Hansen H, Selin C, Huang SC, Barrio JR, Phelps ME. C-11 palmitate for the noninvasive evaluation of regional myocardial fatty acid metabolism with positron-computed tomography. IV. In vivo evaluation of acute demand-induced ischemia in dogs. Am Heart J 1983; 106:736-50. [PMID: 6604447 DOI: 10.1016/0002-8703(83)90096-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Schelbert HR, Henze E, Schon HR, Keen R, Hansen H, Selin C, Huang SC, Barrio JR, Phelps ME. C-11 palmitate for the noninvasive evaluation of regional myocardial fatty acid metabolism with positron computed tomography. III. In vivo demonstration of the effects of substrate availability on myocardial metabolism. Am Heart J 1983; 105:492-504. [PMID: 6600872 DOI: 10.1016/0002-8703(83)90368-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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