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Knight DS, Virsinskaite R, Karia N, Cole AR, Maclean RH, Brown JT, Patel RK, Razvi Y, Venneri L, Kotecha T, Martinez-Naharro A, Kellman P, Scott-Russell AM, Schreiber BE, Ong VH, Denton CP, Fontana M, Coghlan JG, Muthurangu V. Native myocardial T1 and right ventricular size by CMR predict outcome in systemic sclerosis-associated pulmonary hypertension. Rheumatology (Oxford) 2024:keae141. [PMID: 38759116 DOI: 10.1093/rheumatology/keae141] [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: 11/11/2023] [Revised: 01/10/2024] [Accepted: 02/07/2024] [Indexed: 05/19/2024] Open
Abstract
OBJECTIVES Measures of right heart size and function are prognostic in systemic sclerosis-associated pulmonary hypertension (SSc-PH), but the importance of myocardial tissue characterisation remains unclear. We aimed to investigate the predictive potential and interaction of cardiovascular magnetic resonance (CMR) myocardial tissue characterisation and right heart size and function in SSc-PH. METHODS A retrospective, single-centre, observational study of 148 SSc-PH patients confirmed by right heart catheterization who underwent clinically-indicated CMR including native myocardial T1 and T2 mapping from 2016 to 2023 was performed. RESULTS Sixty-six (45%) patients died during follow-up (median 3.5 years, range 0.1-7.3). Patients who died were older (65 vs 60 years, p= 0.035) with more dilated (RVEDVi and RVESVi, p< 0.001), hypertrophied (RVMi, p= 0.013) and impaired (RVEF, p< 0.001) right ventricles, more dilated right atria (RAi, p= 0.043) and higher native myocardial T1 (p< 0.001).After adjustment for age, RVESVi (p = 0.0023) and native T1 (p = 0.0024) were independent predictors of all-cause mortality. Both RVESVi and native T1 remained independently predictive after adjusting for age and PH subtype (RVESVi p < 0.001, T1 p = 0.0056). Optimal prognostic thresholds for RVESVi and native T1 were ≤38 mL/m2 and ≤1119 ms, respectively (p < 0.001). Patients with RVESVi ≤ 38 mL/m2 and native T1 ≤ 1119 ms had significantly better outcomes than all other combinations (p < 0.001). Furthermore, patients with RVESVi > 38mL/m2 and native T1 ≤ 1119 ms had significantly better survival than patients with RVESVi > 38mL/m2 and native T1 > 1119ms (p = 0.017). CONCLUSION We identified prognostically relevant CMR metrics and thresholds for patients with SSc-PH. Assessing myocardial tissue characterisation alongside RV function confers added value in SSc-PH and may represent an additional treatment target.
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Affiliation(s)
- Daniel S Knight
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Ruta Virsinskaite
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Nina Karia
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Alice R Cole
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), London, UK
| | - Rory H Maclean
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), London, UK
| | - James T Brown
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | - Rishi K Patel
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Division of Medicine, University College London, London, UK
| | - Yousuf Razvi
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Division of Medicine, University College London, London, UK
| | - Lucia Venneri
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
| | - Tushar Kotecha
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Institute of Cardiovascular Science, University College London, London, UK
| | | | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, MD, USA
| | | | - Benjamin E Schreiber
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
| | - Voon H Ong
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), London, UK
| | - Christopher P Denton
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), London, UK
| | - Marianna Fontana
- Department of Cardiac MRI, Royal Free London NHS Foundation Trust, London, UK
- Division of Medicine, University College London, London, UK
| | - J Gerry Coghlan
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, London, UK
| | - Vivek Muthurangu
- Institute of Cardiovascular Science, University College London, London, UK
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Knight DS, Karia N, Cole AR, Maclean RH, Brown JT, Masi A, Patel RK, Razvi Y, Chacko L, Venneri L, Kotecha T, Martinez-Naharro A, Kellman P, Scott-Russell AM, Schreiber BE, Ong VH, Denton CP, Fontana M, Coghlan JG, Muthurangu V. Distinct cardiovascular phenotypes are associated with prognosis in systemic sclerosis: a cardiovascular magnetic resonance study. Eur Heart J Cardiovasc Imaging 2023; 24:463-471. [PMID: 35775814 PMCID: PMC10029850 DOI: 10.1093/ehjci/jeac120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/16/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
AIMS Cardiovascular involvement in systemic sclerosis (SSc) is heterogeneous and ill-defined. This study aimed to: (i) discover cardiac phenotypes in SSc by cardiovascular magnetic resonance (CMR); (ii) provide a CMR-based algorithm for phenotypic classification; and (iii) examine for associations between phenotypes and mortality. METHODS AND RESULTS A retrospective, single-centre, observational study of 260 SSc patients who underwent clinically indicated CMR including native myocardial T1 and T2 mapping from 2016 to 2019 was performed. Agglomerative hierarchical clustering using only CMR variables revealed five clusters of SSc patients with shared CMR characteristics: dilated right hearts with right ventricular failure (RVF); biventricular failure dilatation and dysfunction (BVF); and normal function with average cavity (NF-AC), normal function with small cavity (NF-SC), and normal function with large cavity (NF-LC) sizes. Phenotypes did not co-segregate with clinical or antibody classifications. A CMR-based decision tree for phenotype classification was created. Sixty-three (24%) patients died during a median follow-up period of 3.4 years. After adjustment for age and presence of pulmonary hypertension (PH), independent CMR predictors of all-cause mortality were native T1 (P < 0.001) and right ventricular ejection fraction (RVEF) (P = 0.0032). NF-SC and NF-AC groups had more favourable prognoses (P≤0.036) than the other three groups which had no differences in prognoses between them (P > 0.14). Hazard ratios (HR) were statistically significant for RVF (HR = 8.9, P < 0.001), BVF (HR = 5.2, P = 0.006), and NF-LC (HR = 4.9, P = 0.002) groups. The NF-LC group remained significantly predictive of mortality after adjusting for RVEF, native T1, and PH diagnosis (P = 0.0046). CONCLUSION We identified five CMR-defined cardiac SSc phenotypes that did not co-segregate with clinical data and had distinct outcomes, offering opportunities for a more precision-medicine based management approach.
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Affiliation(s)
- Daniel S Knight
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Nina Karia
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Alice R Cole
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Rory H Maclean
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - James T Brown
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ambra Masi
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
| | - Rishi K Patel
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- National Amyloidosis Centre, Division of Medicine, University College London, Rowland Hill Street, London, NW3 2PF, UK
| | - Yousuf Razvi
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- National Amyloidosis Centre, Division of Medicine, University College London, Rowland Hill Street, London, NW3 2PF, UK
| | - Liza Chacko
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- National Amyloidosis Centre, Division of Medicine, University College London, Rowland Hill Street, London, NW3 2PF, UK
| | - Lucia Venneri
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Tushar Kotecha
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
| | - Ana Martinez-Naharro
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- National Amyloidosis Centre, Division of Medicine, University College London, Rowland Hill Street, London, NW3 2PF, UK
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institute of Health, 31 Center Dr, Bethesda, MD 20892, USA
| | - Ann M Scott-Russell
- Department of Rheumatology, Queen Alexandra Hospital, Cosham, Portsmouth, PO6 3LY, UK
| | - Benjamin E Schreiber
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
| | - Voon H Ong
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Christopher P Denton
- Centre for Rheumatology and Connective Tissue Diseases, UCL Medical School (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Marianna Fontana
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
- National Amyloidosis Centre, Division of Medicine, University College London, Rowland Hill Street, London, NW3 2PF, UK
| | - J Gerry Coghlan
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
| | - Vivek Muthurangu
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT, UK
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Rosmini S, Seraphim A, Knott K, Brown JT, Knight DS, Zaman S, Cole G, Sado D, Captur G, Gomes AC, Zemrak F, Treibel TA, Cash L, Culotta V, O’Mahony C, Kellman P, Moon JC, Manisty C. Non-invasive characterization of pleural and pericardial effusions using T1 mapping by magnetic resonance imaging. Eur Heart J Cardiovasc Imaging 2022; 23:1117-1126. [PMID: 34331054 PMCID: PMC9612798 DOI: 10.1093/ehjci/jeab128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
AIMS Differentiating exudative from transudative effusions is clinically important and is currently performed via biochemical analysis of invasively obtained samples using Light's criteria. Diagnostic performance is however limited. Biochemical composition can be measured with T1 mapping using cardiovascular magnetic resonance (CMR) and hence may offer diagnostic utility for assessment of effusions. METHODS AND RESULTS A phantom consisting of serially diluted human albumin solutions (25-200 g/L) was constructed and scanned at 1.5 T to derive the relationship between fluid T1 values and fluid albumin concentration. Native T1 values of pleural and pericardial effusions from 86 patients undergoing clinical CMR studies retrospectively analysed at four tertiary centres. Effusions were classified using Light's criteria where biochemical data was available (n = 55) or clinically in decompensated heart failure patients with presumed transudative effusions (n = 31). Fluid T1 and protein values were inversely correlated both in the phantom (r = -0.992) and clinical samples (r = -0.663, P < 0.0001). T1 values were lower in exudative compared to transudative pleural (3252 ± 207 ms vs. 3596 ± 213 ms, P < 0.0001) and pericardial (2749 ± 373 ms vs. 3337 ± 245 ms, P < 0.0001) effusions. The diagnostic accuracy of T1 mapping for detecting transudates was very good for pleural and excellent for pericardial effusions, respectively [area under the curve 0.88, (95% CI 0.764-0.996), P = 0.001, 79% sensitivity, 89% specificity, and 0.93, (95% CI 0.855-1.000), P < 0.0001, 95% sensitivity; 81% specificity]. CONCLUSION Native T1 values of effusions measured using CMR correlate well with protein concentrations and may be helpful for discriminating between transudates and exudates. This may help focus the requirement for invasive diagnostic sampling, avoiding unnecessary intervention in patients with unequivocal transudative effusions.
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Affiliation(s)
- Stefania Rosmini
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
- King’s College Hospital NHS Trust Foundation, Denmark Hill, London SE5 9RS, UK
| | - Andreas Seraphim
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Kristopher Knott
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - James T Brown
- Royal Free London NHS Foundation Trust, Pond St, London NW3 2QG, UK
| | - Daniel S Knight
- Royal Free London NHS Foundation Trust, Pond St, London NW3 2QG, UK
| | - Sameer Zaman
- Imperial College London, Imperial College, Healthcare NHS Trust, South Kensington, London SW7 2BX, UK
| | - Graham Cole
- Imperial College London, Imperial College, Healthcare NHS Trust, South Kensington, London SW7 2BX, UK
| | - Daniel Sado
- King’s College Hospital NHS Trust Foundation, Denmark Hill, London SE5 9RS, UK
| | - Gabriella Captur
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
- Institute for Cardiovascular Sciences, University College London, 62 Huntley St, London WC1E 6DD, UK
| | - Ana Caterina Gomes
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Filip Zemrak
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Thomas A Treibel
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Lizette Cash
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Veronica Culotta
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Constantinos O’Mahony
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
| | - Peter Kellman
- National Heart, Lung and Blood Institute, National Institutes of Health, Medical Signal and Imaging Processing Program, 10 Center Dr, Bethesda, MD 20814, USA
| | - James C Moon
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
- Institute for Cardiovascular Sciences, University College London, 62 Huntley St, London WC1E 6DD, UK
| | - Charlotte Manisty
- Department of Cardiac Imaging, Barts Heart Centre, St Bartholomew’s Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK
- Institute for Cardiovascular Sciences, University College London, 62 Huntley St, London WC1E 6DD, UK
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Bajaj R, Ramasamy A, Brown JT, Koganti S, Little C, Rathod KS, Jones DA, Rees P, Guttmann O, Lockie T, Ozkor M, Mathur A, Kalra SS, Baumbach A, Bourantas CV, Rakhit R, O'Mahony C. Treatment Strategies and Outcomes of Emergency Left Main Percutaneous Coronary Intervention. Am J Cardiol 2022; 177:1-6. [PMID: 35732552 DOI: 10.1016/j.amjcard.2022.04.043] [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] [Received: 11/24/2021] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/01/2022]
Abstract
Emergency percutaneous coronary intervention of the left main (LM ePCI) coronary artery necessitated by acute coronary syndrome is associated with a high risk of mortality. However, optimal treatment strategies and related outcomes remain undefined in this group. We undertook a multi-center, retrospective, observational cohort study of consecutive patients requiring LM ePCI between 2011 and 2018 and reported the coronary anatomy, treatment strategies, outcomes, and predictors of mortality. A total of 116 consecutive cases were included. Patients were predominantly male (85%) with a median age of 68.0 years; 12 patients (10%) had previous coronary artery bypass grafting. ST-elevation was noted in 76 (66%); 30 (26%) presented with an out-of-hospital cardiac arrest (OOHCA) and 47 (41%) with cardiogenic shock. The most frequent pattern of disease was Medina 1,1,1, seen in 59 patients (51%). The commonest revascularization strategy was provisional stenting (95 cases, 82%) with improved or thrombolysis in myocardial infarction 3 flow seen in 85 cases (73%). All-cause mortality was 35% at 30 days, rising to 58% at 5 years. Adverse predictors of 30-day mortality included presentation with cardiogenic shock (p = 0.018) and OOHCA (p = 0.020), whereas improved flow and/or thrombolysis in myocardial infarction 3 flow in both circumflex and left anterior descending artery afforded a better prognosis (p = 0.028). In conclusion, patients who underwent LM ePCI are a high-risk subgroup and commonly present with cardiogenic shock and OOHCA. Provisional stenting appears to be the preferred option with the successful restoration of coronary flow in most cases despite complex anatomy. High 30-day mortality is driven by the presence of cardiogenic shock, OOHCA, and failure to restore or improve coronary flow.
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Affiliation(s)
- Retesh Bajaj
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom.
| | - Anantharaman Ramasamy
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom
| | - James T Brown
- Institute of Cardiovascular Sciences, University College London, London, United Kingdom; National Pulmonary Hypertension Service; Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Sudheer Koganti
- Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom; Citizens Specialty Hospital, Hyderabad, India
| | - Callum Little
- Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Krishnaraj S Rathod
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom
| | - Daniel A Jones
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom
| | - Paul Rees
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Oliver Guttmann
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Tim Lockie
- Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Mick Ozkor
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Anthony Mathur
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom
| | - Sundeep S Kalra
- Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Andreas Baumbach
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom
| | - Christos V Bourantas
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Queen Mary University London, London, United Kingdom; Institute of Cardiovascular Sciences, University College London, London, United Kingdom
| | - Roby Rakhit
- Department of Cardiology, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Constantinos O'Mahony
- Department of Cardiology, Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; Institute of Cardiovascular Sciences, University College London, London, United Kingdom
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5
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Brown JT, Saigal A, Karia N, Patel RK, Razvi Y, Constantinou N, Steeden JA, Mandal S, Kotecha T, Fontana M, Goldring J, Muthurangu V, Knight DS. Ongoing Exercise Intolerance Following COVID-19: A Magnetic Resonance-Augmented Cardiopulmonary Exercise Test Study. J Am Heart Assoc 2022; 11:e024207. [PMID: 35470679 PMCID: PMC9238618 DOI: 10.1161/jaha.121.024207] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [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] [Indexed: 12/18/2022]
Abstract
Background Ongoing exercise intolerance of unclear cause following COVID-19 infection is well recognized but poorly understood. We investigated exercise capacity in patients previously hospitalized with COVID-19 with and without self-reported exercise intolerance using magnetic resonance-augmented cardiopulmonary exercise testing. Methods and Results Sixty subjects were enrolled in this single-center prospective observational case-control study, split into 3 equally sized groups: 2 groups of age-, sex-, and comorbidity-matched previously hospitalized patients following COVID-19 without clearly identifiable postviral complications and with either self-reported reduced (COVIDreduced) or fully recovered (COVIDnormal) exercise capacity; a group of age- and sex-matched healthy controls. The COVIDreducedgroup had the lowest peak workload (79W [Interquartile range (IQR), 65-100] versus controls 104W [IQR, 86-148]; P=0.01) and shortest exercise duration (13.3±2.8 minutes versus controls 16.6±3.5 minutes; P=0.008), with no differences in these parameters between COVIDnormal patients and controls. The COVIDreduced group had: (1) the lowest peak indexed oxygen uptake (14.9 mL/minper kg [IQR, 13.1-16.2]) versus controls (22.3 mL/min per kg [IQR, 16.9-27.6]; P=0.003) and COVIDnormal patients (19.1 mL/min per kg [IQR, 15.4-23.7]; P=0.04); (2) the lowest peak indexed cardiac output (4.7±1.2 L/min per m2) versus controls (6.0±1.2 L/min per m2; P=0.004) and COVIDnormal patients (5.7±1.5 L/min per m2; P=0.02), associated with lower indexed stroke volume (SVi:COVIDreduced 39±10 mL/min per m2 versus COVIDnormal 43±7 mL/min per m2 versus controls 48±10 mL/min per m2; P=0.02). There were no differences in peak tissue oxygen extraction or biventricular ejection fractions between groups. There were no associations between COVID-19 illness severity and peak magnetic resonance-augmented cardiopulmonary exercise testing metrics. Peak indexed oxygen uptake, indexed cardiac output, and indexed stroke volume all correlated with duration from discharge to magnetic resonance-augmented cardiopulmonary exercise testing (P<0.05). Conclusions Magnetic resonance-augmented cardiopulmonary exercise testing suggests failure to augment stroke volume as a potential mechanism of exercise intolerance in previously hospitalized patients with COVID-19. This is unrelated to disease severity and, reassuringly, improves with time from acute illness.
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Affiliation(s)
- James T. Brown
- National Pulmonary Hypertension ServiceRoyal Free London NHS Foundation TrustLondonUnited Kingdom
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
| | - Anita Saigal
- Department of Respiratory MedicineRoyal Free London NHS Foundation TrustLondonUnited Kingdom
| | - Nina Karia
- National Pulmonary Hypertension ServiceRoyal Free London NHS Foundation TrustLondonUnited Kingdom
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
| | - Rishi K. Patel
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- National Amyloidosis CentreDivision of MedicineUniversity College LondonUnited Kingdom
| | - Yousuf Razvi
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- National Amyloidosis CentreDivision of MedicineUniversity College LondonUnited Kingdom
| | - Natalie Constantinou
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
| | | | - Swapna Mandal
- Department of Respiratory MedicineRoyal Free London NHS Foundation TrustLondonUnited Kingdom
| | - Tushar Kotecha
- National Pulmonary Hypertension ServiceRoyal Free London NHS Foundation TrustLondonUnited Kingdom
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
- Department of CardiologyRoyal Free London NHS Foundation TrustLondonUnited Kingdom
| | - Marianna Fontana
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- National Amyloidosis CentreDivision of MedicineUniversity College LondonUnited Kingdom
| | - James Goldring
- Department of Respiratory MedicineRoyal Free London NHS Foundation TrustLondonUnited Kingdom
| | - Vivek Muthurangu
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
| | - Daniel S. Knight
- National Pulmonary Hypertension ServiceRoyal Free London NHS Foundation TrustLondonUnited Kingdom
- UCL Department of Cardiac MRIUniversity College London (Royal Free Campus)LondonUnited Kingdom
- Institute of Cardiovascular ScienceUniversity College LondonUnited Kingdom
- Department of CardiologyRoyal Free London NHS Foundation TrustLondonUnited Kingdom
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6
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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: 87] [Impact Index Per Article: 29.0] [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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7
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Brown JT, Kotecha T, Steeden JA, Fontana M, Denton CP, Coghlan JG, Knight DS, Muthurangu V. Reduced exercise capacity in patients with systemic sclerosis is associated with lower peak tissue oxygen extraction: a cardiovascular magnetic resonance-augmented cardiopulmonary exercise study. J Cardiovasc Magn Reson 2021; 23:118. [PMID: 34706740 PMCID: PMC8554852 DOI: 10.1186/s12968-021-00817-1] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/24/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Exercise intolerance in systemic sclerosis (SSc) is typically attributed to cardiopulmonary limitations. However, problems with skeletal muscle oxygen extraction have not been fully investigated. This study used cardiovascular magnetic resonance (CMR)-augmented cardiopulmonary exercise testing (CMR-CPET) to simultaneously measure oxygen consumption and cardiac output. This allowed calculation of arteriovenous oxygen content gradient, a recognized marker of oxygen extraction. We performed CMR-CPET in 4 groups: systemic sclerosis (SSc); systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH); non-connective tissue disease pulmonary hypertension (NC-PAH); and healthy controls. METHODS We performed CMR-CPET in 60 subjects (15 in each group) using a supine ergometer following a ramped exercise protocol until exhaustion. Values for oxygen consumption, cardiac output and oxygen content gradient, as well as ventricular volumes, were obtained at rest and peak-exercise for all subjects. In addition, T1 and T2 maps were acquired at rest, and the most recent clinical measures (hemoglobin, lung function, 6-min walk, cardiac and catheterization) were collected. RESULTS All patient groups had reduced peak oxygen consumption compared to healthy controls (p < 0.022). The SSc and SSc-PAH groups had reduced peak oxygen content gradient compared to healthy controls (p < 0.03). Conversely, the SSc-PAH and NC-PH patients had reduced peak cardiac output compared to healthy controls and SSc patients (p < 0.006). Higher hemoglobin was associated with higher peak oxygen content gradient (p = 0.025) and higher myocardial T1 was associated with lower peak stroke volume (p = 0.011). CONCLUSIONS Reduced peak oxygen consumption in SSc patients is predominantly driven by reduced oxygen content gradient and in SSc-PAH patients this was amplified by reduced peak cardiac output. Trial registration The study is registered with ClinicalTrials.gov Protocol Registration and Results System (ClinicalTrials.gov ID: 100358).
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Affiliation(s)
- James T Brown
- Institute of Cardiovascular Science, University College London, London, UK
- Royal Free Hospital, London, UK
| | - Tushar Kotecha
- Institute of Cardiovascular Science, University College London, London, UK
- Royal Free Hospital, London, UK
| | - Jennifer A Steeden
- Institute of Cardiovascular Science, University College London, London, UK
| | - Marianna Fontana
- Royal Free Hospital, London, UK
- Division of Medicine, University College London, London, UK
| | - Christopher P Denton
- Royal Free Hospital, London, UK
- Division of Medicine, University College London, London, UK
| | | | - Daniel S Knight
- Institute of Cardiovascular Science, University College London, London, UK
- Royal Free Hospital, London, UK
| | - Vivek Muthurangu
- Institute of Cardiovascular Science, University College London, London, UK.
- Centre for Cardiovascular Imaging, Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK.
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8
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Kotecha T, Knight DS, Razvi Y, Kumar K, Vimalesvaran K, Thornton G, Patel R, Chacko L, Brown JT, Coyle C, Leith D, Shetye A, Ariff B, Bell R, Captur G, Coleman M, Goldring J, Gopalan D, Heightman M, Hillman T, Howard L, Jacobs M, Jeetley PS, Kanagaratnam P, Kon OM, Lamb LE, Manisty CH, Mathurdas P, Mayet J, Negus R, Patel N, Pierce I, Russell G, Wolff A, Xue H, Kellman P, Moon JC, Treibel TA, Cole GD, Fontana M. Patterns of myocardial injury in recovered troponin-positive COVID-19 patients assessed by cardiovascular magnetic resonance. Eur Heart J 2021; 42:1866-1878. [PMID: 33596594 PMCID: PMC7928984 DOI: 10.1093/eurheartj/ehab075] [Citation(s) in RCA: 238] [Impact Index Per Article: 79.3] [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: 11/10/2020] [Revised: 12/14/2020] [Accepted: 02/03/2021] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Troponin elevation is common in hospitalized COVID-19 patients, but underlying aetiologies are ill-defined. We used multi-parametric cardiovascular magnetic resonance (CMR) to assess myocardial injury in recovered COVID-19 patients. METHODS AND RESULTS One hundred and forty-eight patients (64 ± 12 years, 70% male) with severe COVID-19 infection [all requiring hospital admission, 48 (32%) requiring ventilatory support] and troponin elevation discharged from six hospitals underwent convalescent CMR (including adenosine stress perfusion if indicated) at median 68 days. Left ventricular (LV) function was normal in 89% (ejection fraction 67% ± 11%). Late gadolinium enhancement and/or ischaemia was found in 54% (80/148). This comprised myocarditis-like scar in 26% (39/148), infarction and/or ischaemia in 22% (32/148) and dual pathology in 6% (9/148). Myocarditis-like injury was limited to three or less myocardial segments in 88% (35/40) of cases with no associated LV dysfunction; of these, 30% had active myocarditis. Myocardial infarction was found in 19% (28/148) and inducible ischaemia in 26% (20/76) of those undergoing stress perfusion (including 7 with both infarction and ischaemia). Of patients with ischaemic injury pattern, 66% (27/41) had no past history of coronary disease. There was no evidence of diffuse fibrosis or oedema in the remote myocardium (T1: COVID-19 patients 1033 ± 41 ms vs. matched controls 1028 ± 35 ms; T2: COVID-19 46 ± 3 ms vs. matched controls 47 ± 3 ms). CONCLUSIONS During convalescence after severe COVID-19 infection with troponin elevation, myocarditis-like injury can be encountered, with limited extent and minimal functional consequence. In a proportion of patients, there is evidence of possible ongoing localized inflammation. A quarter of patients had ischaemic heart disease, of which two-thirds had no previous history. Whether these observed findings represent pre-existing clinically silent disease or de novo COVID-19-related changes remain undetermined. Diffuse oedema or fibrosis was not detected.
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Affiliation(s)
- Tushar Kotecha
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, UK
| | - Daniel S Knight
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, UK
| | - Yousuf Razvi
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
| | - Kartik Kumar
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
| | | | - George Thornton
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Rishi Patel
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Liza Chacko
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - James T Brown
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, UK
| | - Clare Coyle
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Donald Leith
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Abhishek Shetye
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
- University College London Hospitals NHS Trust, London, UK
| | - Ben Ariff
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
| | - Robert Bell
- Institute of Cardiovascular Science, University College London, UK
- University College London Hospitals NHS Trust, London, UK
| | - Gabriella Captur
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, UK
| | - Meg Coleman
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
| | - James Goldring
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
| | - Deepa Gopalan
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
| | | | - Toby Hillman
- University College London Hospitals NHS Trust, London, UK
| | - Luke Howard
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Michael Jacobs
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
| | | | - Prapa Kanagaratnam
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Onn Min Kon
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Lucy E Lamb
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Academic Department of Defence Medicine, Royal Centre for Defence Medicine, Edgbaston, Birmingham, UK
| | - Charlotte H Manisty
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | | | - Jamil Mayet
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Rupert Negus
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
| | - Niket Patel
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- Institute of Cardiovascular Science, University College London, UK
| | - Iain Pierce
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Georgina Russell
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Anthony Wolff
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
| | - Hui Xue
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, MD, USA
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institute of Health, Bethesda, MD, USA
| | - James C Moon
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Thomas A Treibel
- Institute of Cardiovascular Science, University College London, UK
- Barts Heart Centre, Barts Health NHS Trust, W Smithfield, London EC1A 7BE, UK
| | - Graham D Cole
- Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK
- National Heart and Lung Institute, Imperial College London, UK
| | - Marianna Fontana
- Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK
- National Amyloidosis Centre, Division of Medicine, University College London, UK
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9
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Chacko L, Boldrini M, Martone R, Law S, Martinez-Naharrro A, Hutt DF, Kotecha T, Patel RK, Razvi Y, Rezk T, Cohen OC, Brown JT, Srikantharajah M, Ganesananthan S, Lane T, Lachmann HJ, Wechalekar AD, Sachchithanantham S, Mahmood S, Whelan CJ, Knight DS, Moon JC, Kellman P, Gillmore JD, Hawkins PN, Fontana M. Cardiac Magnetic Resonance-Derived Extracellular Volume Mapping for the Quantification of Hepatic and Splenic Amyloid. Circ Cardiovasc Imaging 2021; 14:CIRCIMAGING121012506. [PMID: 33876651 DOI: 10.1161/circimaging.121.012506] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Systemic amyloidosis is characterized by amyloid deposition that can involve virtually any organ. Splenic and hepatic amyloidosis occurs in certain types, in some patients but not others, and may influence prognosis and treatment. SAP (serum amyloid P component) scintigraphy is uniquely able to identify and quantify amyloid in the liver and spleen, thus informing clinical management, but it is only available in 2 centers globally. The aims of this study were to examine the potential for extracellular volume (ECV) mapping performed during routine cardiac magnetic resonance to: (1) detect amyloid in the liver and spleen and (2) estimate amyloid load in these sites using SAP scintigraphy as the reference standard. METHODS Five hundred thirty-three patients referred to the National Amyloidosis Centre, London, between 2015 and 2017 with suspected systemic amyloidosis who underwent SAP scintigraphy and cardiac magnetic resonance with T1 mapping were studied. RESULTS The diagnostic performance of ECV to detect splenic and hepatic amyloidosis was high for both organs (liver: area under the curve, -0.917 [95% CI, 0.880-0.954]; liver ECV cutoff, 0.395; sensitivity, 90.7%; specificity, 77.7%; P<0.001; spleen: area under the curve, -0.944 [95% CI, 0.925-0.964]; spleen ECV cutoff, 0.385; sensitivity, 93.6%; specificity, 87.5%; P<0.001). There was good correlation between liver and spleen ECV and amyloid load assessed by SAP scintigraphy (r=0.504, P<0.001; r=0.693, P<0.001, respectively). There was high interobserver agreement for both the liver and spleen (ECV liver intraclass correlation coefficient, 0.991 [95% CI, 0.984-0.995]; P<0.001; ECV spleen intraclass correlation coefficient, 0.995 [95% CI, 0.991-0.997]; P<0.001) with little bias across a wide range of ECV values. CONCLUSIONS Our study demonstrates that ECV measurements obtained during routine cardiac magnetic resonance scans in patients with suspected amyloidosis can identify and measure the magnitude of amyloid infiltration in the liver and spleen, providing important clues to amyloid type and offering a noninvasive measure of visceral amyloid burden that can help guide and track treatment.
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Affiliation(s)
| | | | - Raffaele Martone
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
- Department of Heart, Lung and Vessels, Tuscan Regional Amyloid Center, Careggi University Hospital, Florence, Italy (R.M.)
| | - Steven Law
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Ana Martinez-Naharrro
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - David F Hutt
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | | | - Rishi K Patel
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Yousuf Razvi
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Tamer Rezk
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Oliver C Cohen
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - James T Brown
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Mukunthan Srikantharajah
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Sharmananthan Ganesananthan
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Thirusha Lane
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Helen J Lachmann
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Ashutosh D Wechalekar
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Sajitha Sachchithanantham
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Shameem Mahmood
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Carol J Whelan
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Daniel S Knight
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - James C Moon
- Institute of Cardiovascular Science, University College London, London, United Kingdom. (J.C.M.)
- Barts Heart Centre, Cardiovascular Magnetic Resonance Imaging Unit, and the Inherited Cardiovascular Diseases Unit, St Bartholomew's Hospital, London, United Kingdom (J.C.M.)
| | - Peter Kellman
- Department of Health and Human Services, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (P.K.)
| | - Julian D Gillmore
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Philip N Hawkins
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
| | - Marianna Fontana
- Division of Medicine, National Amyloidosis Centre, University College London, London, United Kingdom. (L.C., M.B., R.M., S.L., A.M.-N., D.F.H., T.K., R.K.P., Y.R., T.R., O.C.C., J.B., M.S., S.G., T.L., H.L., A.W., S.S., S.M., C.W., D.S.K., J.G., P.N.H., M.F.)
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10
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Knight DS, Kotecha T, Razvi Y, Chacko L, Brown JT, Jeetley PS, Goldring J, Jacobs M, Lamb LE, Negus R, Wolff A, Moon JC, Xue H, Kellman P, Patel N, Fontana M. COVID-19: Myocardial Injury in Survivors. Circulation 2020; 142:1120-1122. [PMID: 32673505 DOI: 10.1161/circulationaha.120.049252] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Daniel S Knight
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,Institute of Cardiovascular Science, University College London, United Kingdom (D.S.K., J.T.B., J.C.M., N.P.)
| | - Tushar Kotecha
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - Yousuf Razvi
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - Liza Chacko
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,National Amyloidosis Centre, Division of Medicine, University College London, United Kingdom (L.C., M.F.)
| | - James T Brown
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,Institute of Cardiovascular Science, University College London, United Kingdom (D.S.K., J.T.B., J.C.M., N.P.)
| | - Paramjit S Jeetley
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - James Goldring
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - Michael Jacobs
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - Lucy E Lamb
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,Academic Department of Defence Medicine, Royal Centre for Defence Medicine, ICT Centre, Edgbaston, Birmingham, United Kingdom (L.E.L.)
| | - Rupert Negus
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - Anthony Wolff
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.)
| | - James C Moon
- Institute of Cardiovascular Science, University College London, United Kingdom (D.S.K., J.T.B., J.C.M., N.P.).,Barts Heart Centre, Barts Health NHS Trust, West Smithfield, London, United Kingdom (J.C.M.)
| | - Hui Xue
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (H.X., P.K.)
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (H.X., P.K.)
| | - Niket Patel
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,Institute of Cardiovascular Science, University College London, United Kingdom (D.S.K., J.T.B., J.C.M., N.P.)
| | - Marianna Fontana
- Royal Free London NHS Foundation Trust, United Kingdom (D.S.K., T.K., Y.R., L.C., J.T.B., P.S.J., J.G., M.J., L.E.L., R.N., A.W., N.P., M.F.).,National Amyloidosis Centre, Division of Medicine, University College London, United Kingdom (L.C., M.F.)
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11
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Knight DS, Kotecha T, Martinez-Naharro A, Brown JT, Bertelli M, Fontana M, Muthurangu V, Coghlan JG. Cardiovascular magnetic resonance-guided right heart catheterization in a conventional CMR environment - predictors of procedure success and duration in pulmonary artery hypertension. J Cardiovasc Magn Reson 2019; 21:57. [PMID: 31495338 PMCID: PMC6732841 DOI: 10.1186/s12968-019-0569-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [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: 04/10/2019] [Accepted: 07/23/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Cardiovascular magnetic resonance imaging (CMR) is valuable for the investigation and management of pulmonary artery hypertension (PAH), but the direct measurement of pulmonary hemodynamics by right heart catheterization is still necessary. CMR-guided right heart catheterization (CMR-RHC) combines the benefits of CMR and invasive cardiac catheterization, but its feasibility in patients with acquired PAH has not been established. The aims of this study are to: (1) demonstrate the feasibility of CMR-RHC in patients being assessed for PAH in a conventional diagnostic CMR scanner room; (2) determine the predictors of (i) procedure duration, and (ii) procedural failure or technical difficulty as determined by the adjunctive need for a guidewire. METHODS Fifty patients investigated for suspected or known PH underwent CMR-RHC. Durations of separate procedural components were recorded, including time taken to pass the catheter from the femoral vein to a stable wedge position (procedure time) and total time the patient spent in the CMR department (department time). Associations between procedural failure/guidewire usage and hemodynamic/CMR measures were assessed using logistic regression. Relationships between procedure times and hemodynamic/CMR measures were evaluated using Spearman's correlation coefficient. RESULTS A full CMR-RHC study was successfully completed in 47 (94%) patients. CMR-conditional guidewires were used in 6 (12%) patients. Metrics associated with guidewire use/procedural failure were higher mean pulmonary artery (PA) pressures (mPAP: OR = 1.125, p = 0.018), right heart dilatation (right ventricular (RV) end-systolic volume (RVESV): OR = 1.028, p = 0.018), RV hypertrophy (OR = 1.050, p = 0.0067) and RV ejection fraction (EF) (OR = 0.914, p = 0.014). Median catheter and department times were 3.6 (2.0-7.7) minutes and 60.0 (54.0-68.5) minutes, respectively. All procedure times became significantly shorter with increasing procedural experience (p < 0.05). Catheterization time was also associated with PH severity (RV systolic pressure: rho = 0.46, p = 0.0013) and increasing RV end-systolic volume (RVESV: rho = 0.41, p = 0.0043), hypertrophy (rho = 0.43, p = 0.0025) and dysfunction (RVEF: rho = - 0.32, p = 0.031). CONCLUSIONS This study demonstrates that CMR-RHC using standard technology can be incorporated into routine clinical practice for the investigation of PAH. Procedural failure was rare but more likely in patients with severe PAH. Procedure time is clinically acceptable and increases with worsening PAH severity.
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Affiliation(s)
- Daniel S Knight
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Tushar Kotecha
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Ana Martinez-Naharro
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - James T Brown
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Michele Bertelli
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Marianna Fontana
- UCL Department of Cardiac MRI, University College London (Royal Free Campus), Rowland Hill Street, London, NW3 2PF, UK
| | - Vivek Muthurangu
- Centre for Cardiovascular Imaging, Institute of Cardiovascular Science, University College London and Great Ormond Street Hospital for Children, 30 Guilford Street, London, WC1N 1EH, UK.
| | - J Gerry Coghlan
- National Pulmonary Hypertension Service, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
- Department of Cardiology, Royal Free London NHS Foundation Trust, Pond Street, London, NW3 2QG, UK
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12
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Meagher RL, Watrous KM, Fleischer SJ, Nagoshi RN, Brown JT, Bowers K, Miller N, Hight SD, Legaspi JC, Westbrook JK. Documenting Potential Sunn Hemp (Crotalaria juncea L.) (Fabaceae) Pollinators in Florida. Environ Entomol 2019; 48:343-350. [PMID: 30753472 DOI: 10.1093/ee/nvy190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Indexed: 06/09/2023]
Abstract
Sunn hemp, Crotalaria juncea L., is a warm-season legume that can be planted in rotation to cash crops to add nitrogen and organic matter to the soils, for weed growth prevention, and to suppress nematode populations. Sunn hemp flowers also provide nectar and pollen for pollinators and enhance biological control by furnishing habitat for natural enemies. Experiments were conducted in Northern and North Central Florida to evaluate bee populations that visited flowers within mixed plots of sunn hemp and sorghum-sudangrass and plots of two sunn hemp germplasm lines. Collections of bees that visited 'AU Golden' and Tillage Sunn flowers indicated that Xylocopa virginica (L.) (Hymenoptera: Apidae), Xylocopa micans Lepeletier (Hymenoptera: Apidae), Megachile sculpturalis Smith (Hymenoptera: Megachilidae), Megachile mendica (Cresson) (Hymenoptera: Megachilidae), and Megachile georgica Cresson (Hymenoptera: Megachilidae) were present in large numbers in May through July and then again in October. Although Tillage Sunn seeds planted in March flowered in May, percent bloom and number of bee visits were low. Compared with short day sunn hemp cultivars, 'AU Golden' plants produced flowers early in the season to provide food and habitat for pollinators and have the potential to produce an abundant seed crop in Northern and North Central Florida.
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Affiliation(s)
- Robert L Meagher
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Gainesville, FL
| | - Kristal M Watrous
- Department of Entomology, University of California, Riverside, Riverside, CA
| | - Shelby J Fleischer
- Department of Entomology, Pennsylvania State University, University Park, PA
| | - Rodney N Nagoshi
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Gainesville, FL
| | - James T Brown
- Entomology and Nematology Department, University of Florida, Gainesville, FL
| | - Kristen Bowers
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Tallahassee, FL
| | - Neil Miller
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Tallahassee, FL
| | - Stephen D Hight
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Tallahassee, FL
| | - Jesusa C Legaspi
- USDA-ARS CMAVE, Insect Behavior and Biocontrol Research Unit, Tallahassee, FL
| | - John K Westbrook
- USDA-ARS SPARC, Insect Control and Cotton Disease Research Unit, College Station, TX
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13
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Brown JT, Abdel-Rahman SM, van Haandel L, Gaedigk A, Lin YS, Leeder JS. Single dose, CYP2D6 genotype-stratified pharmacokinetic study of atomoxetine in children with ADHD. Clin Pharmacol Ther 2016; 99:642-50. [PMID: 26660002 DOI: 10.1002/cpt.319] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 01/22/2023]
Abstract
The effect of CYP2D6 genotype on the dose-exposure relationship for atomoxetine has not been well characterized in children. Children 6-17 years of age diagnosed with attention-deficit hyperactivity disorder (ADHD) were stratified by CYP2D6 genotype into groups with 0 (poor metabolizers [PMs], n = 4), 0.5 (intermediate metabolizers [IMs], n = 3), one (extensive metabolizer [EM]1, n = 8) or two (EM2, n = 8) functional alleles and administered a single 0.5 mg/kg oral dose of atomoxetine (ATX). Plasma and urine samples were collected for 24 (IM, EM1, and EM2) or 72 hours (PMs). Dose-corrected ATX systemic exposure (area under the curve [AUC]0-∞ ) varied 29.6-fold across the study cohort, ranging from 4.4 ± 2.7 μM*h in EM2s to 5.8 ± 1.7 μM*h, 16.3 ± 2.9 μM*h, and 50.2 ± 7.3 μM*h in EM1s, IMs, and PMs, respectively (P < 0.0001). Simulated steady state profiles at the maximum US Food and Drug Administration (FDA)-recommended dose suggest that most patients are unlikely to attain adequate ATX exposures. These data support the need for individualized dosing strategies for more effective use of the medication.
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Affiliation(s)
- J T Brown
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota College of Pharmacy, Duluth, Minnesota, USA
| | - S M Abdel-Rahman
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - L van Haandel
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - A Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Y S Lin
- Department of Pharmaceutics, University of Washington School of Pharmacy, Seattle, Washington, USA
| | - J S Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
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14
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Witton J, Padmashri R, Zinyuk LE, Popov VI, Kraev I, Line SJ, Jensen TP, Tedoldi A, Cummings DM, Tybulewicz VLJ, Fisher EMC, Bannerman DM, Randall AD, Brown JT, Edwards FA, Rusakov DA, Stewart MG, Jones MW. Hippocampal circuit dysfunction in the Tc1 mouse model of Down syndrome. Nat Neurosci 2015; 18:1291-1298. [PMID: 26237367 PMCID: PMC4552261 DOI: 10.1038/nn.4072] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [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: 05/19/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
Abstract
Hippocampal pathology is likely to contribute to cognitive disability in Down syndrome, yet the neural network basis of this pathology and its contributions to different facets of cognitive impairment remain unclear. Here we report dysfunctional connectivity between dentate gyrus and CA3 networks in the transchromosomic Tc1 mouse model of Down syndrome, demonstrating that ultrastructural abnormalities and impaired short-term plasticity at dentate gyrus-CA3 excitatory synapses culminate in impaired coding of new spatial information in CA3 and CA1 and disrupted behavior in vivo. These results highlight the vulnerability of dentate gyrus-CA3 networks to aberrant human chromosome 21 gene expression and delineate hippocampal circuit abnormalities likely to contribute to distinct cognitive phenotypes in Down syndrome.
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Affiliation(s)
- J Witton
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - R Padmashri
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - L E Zinyuk
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - V I Popov
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Reg. 142290, Russia.,The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - I Kraev
- The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - S J Line
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK
| | - T P Jensen
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - A Tedoldi
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - D M Cummings
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - V L J Tybulewicz
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - E M C Fisher
- Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK
| | - D M Bannerman
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK
| | - A D Randall
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - J T Brown
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - F A Edwards
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - D A Rusakov
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.,Laboratory of Brain Microcircuits, Institute of Biology and Biomedicine, University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
| | - M G Stewart
- The Open University, Department of Life Sciences, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - M W Jones
- School of Physiology & Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
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15
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Brown JT, Wicklund BM, Abdel-Rahman SM. Individualized factor IX dosing in two brothers: application of longitudinal pharmacokinetic modelling to optimize therapeutic benefit. Haemophilia 2014; 21:e125-e127. [PMID: 25420419 DOI: 10.1111/hae.12593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2014] [Indexed: 11/25/2022]
Affiliation(s)
- J T Brown
- Division of Clinical Pharmacology and Therapeutic Innovation, Children's Mercy Hospitals and Clinics, Kansas, Missouri, USA
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16
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Kerrigan TL, Brown JT, Randall AD. Characterization of altered intrinsic excitability in hippocampal CA1 pyramidal cells of the Aβ-overproducing PDAPP mouse. Neuropharmacology 2014; 79:515-24. [PMID: 24055500 PMCID: PMC3989024 DOI: 10.1016/j.neuropharm.2013.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/21/2013] [Accepted: 09/04/2013] [Indexed: 11/27/2022]
Abstract
Transgenic mice that accumulate Aβ peptides in the CNS are commonly used to interrogate functional consequences of Alzheimer's disease-associated amyloidopathy. In addition to changes to synaptic function, there is also growing evidence that changes to intrinsic excitability of neurones can arise in these models of amyloidopathy. Furthermore, some of these alterations to intrinsic properties may occur relatively early within the age-related progression of experimental amyloidopathy. Here we report a detailed comparison between the intrinsic excitability properties of hippocampal CA1 pyramidal neurones in wild-type (WT) and PDAPP mice. The latter is a well-established model of Aβ accumulation which expresses human APP harbouring the Indiana (V717F) mutation. At the age employed in this study (9-10 months) CNS Abeta was elevated in PDAPP mice but significant plaque pathology was absent. PDAPP mice exhibited no differences in subthreshold intrinsic properties including resting potential, input resistance, membrane time constant and sag. When CA1 cells of PDAPP mice were given depolarizing stimuli of various amplitudes they initially fired at a higher frequency than WT cells. Commensurate with this, PDAPP cells exhibited a larger fast afterdepolarizing potential. PDAPP mice had narrower spikes but action potential threshold, rate of rise and peak were not different. Thus not all changes seen in our previous studies of amyloidopathy models were present in PDAPP mice; however, narrower spikes, larger ADPs and the propensity to fire at higher frequencies were consistent with our prior work and thus may represent robust, cross-model, indices of amyloidopathy. This article is part of a Special Issue entitled 'Neurodevelopment Disorder'.
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Affiliation(s)
- T L Kerrigan
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - J T Brown
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK
| | - A D Randall
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK.
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Forsyth LH, Witton J, Brown JT, Randall AD, Jones MW. In Vitro and In Vivo Recording of Local Field Potential Oscillations in Mouse Hippocampus. ACTA ACUST UNITED AC 2012; 2:273-94. [PMID: 26069015 DOI: 10.1002/9780470942390.mo120089] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oscillations in hippocampal local field potentials (LFP) reflect the coordinated, rhythmic activity of constituent interneuronal and principal cell populations. Quantifying changes in oscillatory patterns and power therefore provides a powerful metric through which to infer mechanisms and functions of hippocampal network activity at the mesoscopic level, bridging single-neuron studies to behavioral assays of hippocampal function. Here, complementary protocols that enable mechanistic analyses of oscillation generation in vitro (in slices and a whole hippocampal preparation) and functional analyses of hippocampal circuits in behaving mice are described. Used together, these protocols provide a comprehensive view of hippocampal phenotypes in mouse models, highlighting oscillatory biomarkers of hippocampal function and dysfunction. Curr. Protoc. Mouse Biol. 2:273-294 © 2012 by John Wiley & Sons, Inc.
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Affiliation(s)
- L H Forsyth
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - J Witton
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - J T Brown
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - A D Randall
- Pfizer Applied Neurophysiology Group, School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - M W Jones
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
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Brown JT, Laosinchai-Wolf W, Hedges JB, Watt CD, Van Deerlin VM, Fletcher L, Branford S, Labourier E. Establishment of a standardized multiplex assay with the analytical performance required for quantitative measurement of BCR-ABL1 on the international reporting scale. Blood Cancer J 2011; 1:e13. [PMID: 22829126 PMCID: PMC3255280 DOI: 10.1038/bcj.2011.10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 02/15/2011] [Indexed: 11/26/2022] Open
Abstract
Accurate and standardized methods for the quantitative measurement of BCR–ABL1 are a prerequisite for monitoring of treatment response in t(9;22)-positive leukemia. Here, we describe a novel multiplex assay system based on the proven TaqMan and Armored RNA technologies and optimized for sensitive detection of three BCR–ABL1 fusion transcripts and ABL1 in a single reaction. Analytical experiments confirmed the absence of significant competition between the simultaneous amplification reactions and established the sensitivity, linearity and precision of the assay. Comparative studies with 115 clinical specimens resulted in high qualitative and quantitative agreement with independent singleplex laboratory-developed tests routinely used in clinical testing. Direct comparison with a reference laboratory calibrated to the international scale (IS) demonstrated minimal analytical bias between methods and an overall accuracy and precision within the performance range required for quantitative measurement of BCR–ABL1 on the IS. We conclude that detection of e1a2, b2a2, b3a2 and ABL1 can be achieved in a multiplex assay format compatible with IS reporting. Further clinical validation of the assay could improve the operational efficiency of clinical laboratories, increase their adherence to current recommendations for b2a2/b3a2 reporting on the IS and provide for the first time an opportunity to standardize e1a2-monitoring results.
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Chater TE, Henley JM, Brown JT, Randall AD. Voltage- and temperature-dependent gating of heterologously expressed channelrhodopsin-2. J Neurosci Methods 2010; 193:7-13. [PMID: 20691205 DOI: 10.1016/j.jneumeth.2010.07.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 07/27/2010] [Accepted: 07/27/2010] [Indexed: 10/19/2022]
Abstract
Channelrhodopsins are light-activated channels originally isolated from algae that are being used increasingly as tools to non-invasively stimulate neurones. Despite their widespread use some aspects of their biophysical properties have not been fully characterised. Here we report detailed investigation of the gating kinetics and voltage-dependence of ChR2 transiently expressed in HEK-293 cells. Currents were elicited using light pulses of defined duration and intensity generated by a blue LED. Datasets were gathered both at room temperature (RT, ∼22°C) and 37°C. Current responses to light rose rapidly to a peak and then desensitized to a steady state plateau. When illumination was terminated currents rapidly deactivated. Recovery from desensitization at -85 mV was slow with half-times of 1.4 and 3.1s at 37°C and ∼22°C, respectively. At both temperatures, the reversal potential of ChR2 responses was a few mV positive to 0 mV. Both the peak and plateau phases of ChR2 responses exhibited strong inward rectification with only small outward currents at positive membrane potentials. The rates of ChR2 activation, deactivation and desensitization were ∼2 times faster at 37°C than at ∼22°C. Both the activation and deactivation kinetics of ChR2 were significantly slowed by depolarization at both temperatures. Additionally, the degree of steady state desensitization was greater at more depolarized potentials. The macroscopic desensitization kinetics were not voltage-dependent, but recovery from desensitization was slowed by depolarization. These gating behaviour data provide an important basis for more detailed analysis of the properties and limitations of ChR2 use in more complex systems.
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Affiliation(s)
- T E Chater
- MRC Centre for Synaptic Plasticity, University of Bristol, University Walk, Bristol, UK
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Abstract
Seeds in a conifer cone from the Lower Permian of west Texas contain embryo tissue. These are the oldest plant embryos on record. Their development prior to seed dispersal shows that the sequence of embryo growth typical of most modern seed plants had evolved before the end of the Paleozoic Era.
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Randall AD, Witton J, Booth C, Hynes-Allen A, Brown JT. The functional neurophysiology of the amyloid precursor protein (APP) processing pathway. Neuropharmacology 2010; 59:243-67. [PMID: 20167227 DOI: 10.1016/j.neuropharm.2010.02.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 01/12/2023]
Abstract
Amyloid beta (Abeta) peptides derived from proteolytic cleavage of amyloid precursor protein (APP) are thought to be a pivotal toxic species in the pathogenesis of Alzheimer's disease (AD). Furthermore, evidence has been accumulating that components of APP processing pathway are involved in non-pathological normal function of the CNS. In this review we aim to cover the extensive body of research aimed at understanding how components of this pathway contribute to neurophysiological function of the CNS in health and disease. We briefly outline changes to clinical neurophysiology seen in AD patients before discussing functional changes in mouse models of AD which range from changes to basal synaptic transmission and synaptic plasticity through to abnormal synchronous network activity. We then describe the various neurophysiological actions that are produced by application of exogenous Abeta in various forms, and finally discuss a number or other neurophysiological aspects of the APP pathway, including functional activities of components of secretase complexes other than Abeta production.
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Affiliation(s)
- A D Randall
- MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK.
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Langmead CJ, Austin NE, Branch CL, Brown JT, Buchanan KA, Davies CH, Forbes IT, Fry VAH, Hagan JJ, Herdon HJ, Jones GA, Jeggo R, Kew JNC, Mazzali A, Melarange R, Patel N, Pardoe J, Randall AD, Roberts C, Roopun A, Starr KR, Teriakidis A, Wood MD, Whittington M, Wu Z, Watson J. Characterization of a CNS penetrant, selective M1 muscarinic receptor agonist, 77-LH-28-1. Br J Pharmacol 2008; 154:1104-15. [PMID: 18454168 DOI: 10.1038/bjp.2008.152] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE M1 muscarinic ACh receptors (mAChRs) represent an attractive drug target for the treatment of cognitive deficits associated with diseases such as Alzheimer's disease and schizophrenia. However, the discovery of subtype-selective mAChR agonists has been hampered by the high degree of conservation of the orthosteric ACh-binding site among mAChR subtypes. The advent of functional screening assays has enabled the identification of agonists such as AC-42 (4-n-butyl-1-[4-(2-methylphenyl)-4-oxo-1-butyl]-piperidine), which bind to an allosteric site and selectively activate the M(1) mAChR subtype. However, studies with this compound have been limited to recombinantly expressed mAChRs. EXPERIMENTAL APPROACH In this study, we have compared the pharmacological profile of AC-42 and a close structural analogue, 77-LH-28-1 (1-[3-(4-butyl-1-piperidinyl)propyl]-3,4-dihydro-2(1H)-quinolinone) at human recombinant, and rat native, mAChRs by calcium mobilization, inositol phosphate accumulation and both in vitro and in vivo electrophysiology. KEY RESULTS Calcium mobilization and inositol phosphate accumulation assays revealed that both AC-42 and 77-LH-28-1 display high selectivity to activate the M1 mAChR over other mAChR subtypes. Furthermore, 77-LH-28-1, but not AC-42, acted as an agonist at rat hippocampal M1 receptors, as demonstrated by its ability to increase cell firing and initiate gamma frequency network oscillations. Finally, 77-LH-28-1 stimulated cell firing in the rat hippocampus in vivo following subcutaneous administration. CONCLUSIONS AND IMPLICATIONS These data suggest that 77-LH-28-1 is a potent, selective, bioavailable and brain-penetrant agonist at the M1 mAChR and therefore that it represents a better tool than AC-42, with which to study the pharmacology of the M1 mAChR.
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Affiliation(s)
- C J Langmead
- Psychiatry Centre of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, Essex, UK.
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Piccinin S, Randall AD, Brown JT. KCNQ/Kv7 channel regulation of hippocampal gamma-frequency firing in the absence of synaptic transmission. J Neurophysiol 2006; 95:3105-12. [PMID: 16467425 DOI: 10.1152/jn.01083.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 11/22/2022] Open
Abstract
Synchronous neuronal firing can be induced in hippocampal slices in the absence of synaptic transmission by lowering extracellular Ca2+ and raising extracellular K+. However, the ionic mechanisms underlying this nonsynaptic synchronous firing are not well understood. In this study we have investigated the role of KCNQ/Kv7 channels in regulating this form of nonsynaptic bursting activity. Incubation of rat hippocampal slices in reduced (<0.2 mM) [Ca2+]o and increased (6.3 mM) [K+]o, blocked synaptic transmission, increased neuronal firing, and led to the development of spontaneous periodic nonsynaptic epileptiform activity. This activity was recorded extracellularly as large (4.7 +/- 1.9 mV) depolarizing envelopes with superimposed high-frequency synchronous population spikes. These intraburst population spikes initially occurred at a high frequency (about 120 Hz), which decayed throughout the burst stabilizing in the gamma-frequency band (30-80 Hz). Further increasing [K+]o resulted in an increase in the interburst frequency without altering the intraburst population spike frequency. Application of retigabine (10 microM), a Kv7 channel modulator, completely abolished the bursts, in an XE-991-sensitive manner. Furthermore, application of the Kv7 channel blockers, linopirdine (10 microM) or XE-991 (10 microM) alone, abolished the gamma frequency, but not the higher-frequency population spike firing observed during low Ca2+/high K+ bursts. These data suggest that Kv7 channels are likely to play a role in the regulation of synchronous population firing activity.
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Affiliation(s)
- S Piccinin
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK
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Brown JT, Teriakidis A, Randall AD. A pharmacological investigation of the role of GLUK5-containing receptors in kainate-driven hippocampal gamma band oscillations. Neuropharmacology 2005; 50:47-56. [PMID: 16153668 DOI: 10.1016/j.neuropharm.2005.07.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [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: 05/20/2005] [Revised: 07/22/2005] [Accepted: 07/22/2005] [Indexed: 10/25/2022]
Abstract
Low concentrations of kainate can induce gamma frequency (25-80 Hz) oscillations in hippocampal slices as well as other brain structures in vitro. Little is known, however, about the kainate receptor (KAR) subtypes that underlie this type of rhythmic neuronal network activity. In this study, the role of GLU(K5) subunit-containing KARs in kainate-induced hippocampal gamma frequency oscillations was assessed using GLU(K5)-selective pharmacological ligands. Activation of GLU(K5)-containing subunits using the selective agonists (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid (ATPA; 0.1-1 microM) or iodowillardiine (0.1-1 microM) failed to induce gamma frequency oscillations in area CA3 of the rat hippocampal slice. Likewise, preincubation with a selective GLU(K5) antagonist, (RS)-3-(2-carboxybenzyl)willardiine (UBP296), did not prevent the appearance of gamma oscillations induced by 150 nM kainate. However, addition of UBP296 (10 microM) to hippocampal slices in which kainate-driven gamma oscillations were pre-established resulted in an approximately 50% reduction in gamma frequency power. These effects occurred in the absence of any effect on AMPA receptor-mediated synaptic transmission. Furthermore, carbachol-induced gamma oscillations were also unaffected by application of UBP296. These results suggest that GLU(K5)-containing KARs are not alone sufficient to generate gamma frequency oscillations, but are involved in maintaining neuronal network activity induced by the actions of kainate at other KARs such as GLU(K6).
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Affiliation(s)
- J T Brown
- Neurology and GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research and Development Limited, New Frontiers Science Park (North), Harlow, Essex, UK.
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Abstract
Anabolic steroids have not currently made their way into the daily practice of emergency physicians. The patients that use and abuse them have. In addition, those patients that are suffering from the consequences of illnesses that have excess levels of androgens are commonly evaluated in the emergency department. Clinicians should familiarize themselves with the practices of anabolic steroid users, so they can provide more beneficial council to their patients. As research continues, the emergency physician may find uses for androgens within the emergency department.
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Affiliation(s)
- James T Brown
- OSF Saint Francis Medical Center, 530 N.E. Glen Oak, Peoria, IL 61637, USA.
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Spencer JP, Brown JT, Richardson JC, Medhurst AD, Sehmi SS, Calver AR, Randall AD. Modulation of hippocampal excitability by 5-HT4 receptor agonists persists in a transgenic model of Alzheimer's disease. Neuroscience 2005; 129:49-54. [PMID: 15489027 DOI: 10.1016/j.neuroscience.2004.06.070] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2004] [Indexed: 10/26/2022]
Abstract
5-HT(4) receptors are widely distributed in both peripheral and central nervous systems where they couple, via a G-protein, to the activation of adenylate cyclase. In the brain, the highest 5-HT(4) receptor densities are found in the limbic system, including the hippocampus and frontal cortex. It has been suggested that activation of these receptors may be of therapeutic benefit in diseases that produce cognitive deficits such as Alzheimer's disease (AD). Previous electrophysiological studies have shown that the 5-HT(4) agonist, Zacopride, can increase population spike amplitude recorded in region CA1 of rat hippocampal slices in a cyclic AMP (cAMP)/cAMP-dependent protein kinase A-dependent manner. We report here that the 5-HT(4) agonist, Prucalopride, and the 5-HT(4) partial agonist, SL65.0155, produce a similar effect in rat hippocampal slices and that the specific 5-HT(4) antagonist, GR113808, blocks these effects. To investigate the potential use of 5-HT(4) agonists in the treatment of AD, Prucalopride was applied to hippocampal slices from a transgenic mouse line that overexpresses the Abeta peptide. Despite the deficit in synaptic transmission present in these mice, the percentage increase of the CA1 population spike induced by Prucalopride was the same as that observed in wild-type mice. These data support 5-HT(4) receptors as a target for cognitive enhancement and suggest that a partial agonist would be sufficient to produce benefits, while reducing potential peripheral side effects. In addition, we show that 5-HT(4) receptors remain functional in the presence of excess Abeta peptide and may therefore be a useful target in AD.
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Affiliation(s)
- J P Spencer
- Neurology and GI CEDD, GlaxoSmithKline, Harlow, Essex CM19 5AW, UK.
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Harrison SM, Reavill C, Brown G, Brown JT, Cluderay JE, Crook B, Davies CH, Dawson LA, Grau E, Heidbreder C, Hemmati P, Hervieu G, Howarth A, Hughes ZA, Hunter AJ, Latcham J, Pickering S, Pugh P, Rogers DC, Shilliam CS, Maycox PR. LPA1 receptor-deficient mice have phenotypic changes observed in psychiatric disease. Mol Cell Neurosci 2004; 24:1170-9. [PMID: 14697676 DOI: 10.1016/j.mcn.2003.09.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [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: 11/26/2022] Open
Abstract
Several psychiatric diseases, including schizophrenia, are thought to have a developmental aetiology, but to date no clear link has been made between psychiatric disease and a specific developmental process. LPA(1) is a G(i)-coupled seven transmembrane receptor with high affinity for lysophosphatidic acid. Although LPA(1) is expressed in several peripheral tissues, in the nervous system it shows relatively restricted temporal expression to neuroepithelia during CNS development and to myelinating glia in the adult. We report the detailed neurological and behavioural analysis of mice homozygous for a targeted deletion at the lpa(1) locus. Our observations reveal a marked deficit in prepulse inhibition, widespread changes in the levels and turnover of the neurotransmitter 5-HT, a brain region-specific alteration in levels of amino acids, and a craniofacial dysmorphism in these mice. We suggest that the loss of LPA(1) receptor generates defects resembling those found in psychiatric disease.
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Affiliation(s)
- S M Harrison
- Comparative Genomics, GlaxoSmithKline, Harlow, Essex, UK
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Abstract
Recent experiments have demonstrated that formation of functional type B gamma-aminobutyric acid (GABA(B)) receptors requires co-expression of two receptor subunits, GABA(B1) and GABA(B2). Despite the identification of these subunits and a number of associated splice variants, there has been little convincing evidence of pharmacological diversity between GABA(B) receptors comprising different subunit combinations. However, Ng et al. [Mol. Pharmacol., 59 (2000) 144] have recently suggested a novel and important pharmacological difference between GABA(B) receptor heterodimers expressing the GABA(B1a) and GABA(B1b) receptor subunits. This study suggested that the antiepileptic GABA analogue gabapentin (Neurontin) is an agonist at GABA(B) receptors expressing the GABA(B1a) but not the GABA(B1b) receptor subunit. The importance of this finding with respect to identifying novel GABA(B) receptor subunit specific agonists prompted us to repeat these experiments in our own [35S]-GTPgammaS binding and second messenger assay systems. Here we report that gabapentin was completely inactive at recombinant GABA(B) heterodimers expressing either GABA(B1a) or GABA(B1b) receptor subunits in combination with GABA(B2) receptor subunits. In addition, in both CA1 and CA3 pyramidal neurones from rodent hippocampal slices we were unable to demonstrate any agonist-like effects of gabapentin at either pre- or post-synaptic GABA(B) receptors. In contrast, gabapentin activated a GABA(A) receptor mediated chloride conductance. Our data suggest that gabapentin is not a GABA(B)-receptor agonist let alone a GABA(B) receptor subunit selective agonist.
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Affiliation(s)
- C Lanneau
- Neurology Centre of Excellence for Drug Discovery, GlaxoSmithKline, New Frontiers Science Park North, Third Avenue, Essex, CM19 5AW, Harlow, UK
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Brown JT, Johnson AW. A cis-acting element known to block 3' mRNA degradation enhances expression of polyA-minus mRNA in wild-type yeast cells and phenocopies a ski mutant. RNA 2001; 7:1566-1577. [PMID: 11720286 PMCID: PMC1370199] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
mRNA lacking a 3' polyA tail is not translated efficiently in wild-type eukaryotic cells, but is translated efficiently in yeast ski mutants. This enhanced expression could be due to altered translational specificity. However, as the SKI genes are required for 3' mRNA degradation, it could be a consequence of inhibition of 3' mRNA decay. Therefore, we asked if inhibition of 3' decay of a polyA-minus mRNA in cis would allow its efficient expression in wild-type cells. Capped in vitro reporter transcripts were prepared with or without a 3' cis-acting element known to inhibit 3' degradation (oligoG) and electroporated into yeast cells. The addition of oligoG to a polyA-minus mRNA enhanced expression 30-fold in wild-type cells. This level of expression was the same as that for an oligoG-minus, polyA-minus transcript in a ski mutant. The addition of oligoG did not significantly enhance the expression of polyA-minus mRNA in a ski mutant. The oligoG-dependent increase in expression was due to an increase in initial rate of translation and an increase in the functional half-life of the mRNA, similar to the effects observed in a ski mutant. The enhanced expression of the oligoG-containing RNA did not require Pab1p. We conclude that the enhanced translation of polyA-minus RNA in a ski mutant is due to inhibition of 3' mRNA degradation. Furthermore, a polyA-minus mRNA is expressed in wild-type cells when terminated in an element known to inhibit 3' decay in cis.
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Affiliation(s)
- J T Brown
- Department of Molecular Genetics and Microbiology and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712-1095, USA
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Brown JT, Yang X, Johnson AW. Inhibition of mRNA turnover in yeast by an xrn1 mutation enhances the requirement for eIF4E binding to eIF4G and for proper capping of transcripts by Ceg1p. Genetics 2000; 155:31-42. [PMID: 10790382 PMCID: PMC1461062 DOI: 10.1093/genetics/155.1.31] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Null mutants of XRN1, encoding the major cytoplasmic exoribonuclease in yeast, are viable but accumulate decapped, deadenylated transcripts. A screen for mutations synthetic lethal with xrn1Delta identified a mutation in CDC33, encoding eIF4E. This mutation (glutamate to glycine at position 72) affected a highly conserved residue involved in interaction with eIF4G. Synthetic lethality between xrn1 and cdc33 was not relieved by high-copy expression of eIF4G or by disruption of the yeast eIF4E binding protein Caf20p. High-copy expression of a mutant eIF4G defective for eIF4E binding resulted in a dominant negative phenotype in an xrn1 mutant, indicating the importance of this interaction in an xrn1 mutant. Another allele of CDC33, cdc33-1, along with mutations in CEG1, encoding the nuclear guanylyltransferase, were also synthetic lethal with xrn1Delta, whereas mutations in PRT1, encoding a subunit of eIF3, were not. Mutations in CDC33, CEG1, PRT1, PAB1, and TIF4631, encoding eIF4G1, have been shown to lead to destabilization of mRNAs. Although such destabilization in cdc33, ceg1, and pab1 mutants can be partially suppressed by an xrn1 mutation, we observed synthetic lethality between xrn1 and either cdc33 or ceg1 and no suppression of the inviability of a pab1 null mutation by xrn1Delta. Thus, the inhibition of mRNA turnover by blocking Xrn1p function does not suppress the lethality of defects upstream in the turnover pathway but it does enhance the requirement for (7)mG caps and for proper formation of the eIF4E/eIF4G cap recognition complex.
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Affiliation(s)
- J T Brown
- Section of Molecular Genetics and Microbiology and the Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712-1095, USA
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Abstract
The yeast superkiller (SKI) genes were originally identified from mutations allowing increased production of killer toxin encoded by M "killer" virus, a satellite of the dsRNA virus L-A. XRN1 (SKI1) encodes a cytoplasmic 5'-exoribonuclease responsible for the majority of cytoplasmic RNA turnover, whereas SKI2, SKI3, and SKI8 are required for normal 3'-degradation of mRNA and for repression of translation of poly(A) minus RNA. Ski2p is a putative RNA helicase, Ski3p is a tetratricopeptide repeat (TPR) protein, and Ski8p contains five WD-40 (beta-transducin) repeats. An xrn1 mutation in combination with a ski2, ski3, or ski8 mutation is lethal, suggesting redundancy of function. Using functional epitope-tagged Ski2, Ski3, and Ski8 proteins, we show that Ski2p, Ski3p, and Ski8p can be coimmunoprecipitated as an apparent heterotrimeric complex. With epitope-tagged Ski2p, there was a 1:1:1 stoichiometry of the proteins in the complex. Ski2p did not associate with Ski3p in the absence of Ski8p, nor did Ski2p associate with Ski8p in the absence of Ski3p. However, the Ski3p/Ski8p interaction did not require Ski2p. In addition, ski6-2 or ski4-1 mutations or deletion of SKI7 did not affect complex formation. The identification of a complex composed of Ski2p, Ski3p, and Ski8p explains previous results showing phenotypic similarity between mutations in SKI2, SKI3, and SKI8. Indirect immunofluorescence of Ski3p and subcellular fractionation of Ski2p and Ski3p suggest that Ski2p and Ski3p are cytoplasmic. These data support the idea that Ski2p, Ski3p, and Ski8p function in the cytoplasm in a 3'-mRNA degradation pathway.
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Affiliation(s)
- J T Brown
- Section of Molecular Genetics and Microbiology and The Institute for Cellular and Molecular Biology, The University of Texas at Austin, 78712-1095, USA
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Kurtis KE, Monteiro PJ, Brown JT, Meyer-Ilse W. High resolution transmission soft X-ray microscopy of deterioration products developed in large concrete dams. J Microsc 1999; 196 (Pt 3):288-98. [PMID: 10594769 DOI: 10.1046/j.1365-2818.1999.00587.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In concrete structures, the reaction of certain siliceous aggregates with the highly alkaline concrete pore solution produces an alkali-silicate gel that can absorb water and expand. This reaction can lead to expansion, cracking, increased permeability, and decreased strength of the concrete. Massive concrete structures, such as dams, are particularly susceptible to the damage caused by the alkali-silica reaction because of the availability of water and because massive gravity dams usually do not contain steel reinforcement to restrain the expansion. Both the cement hydration products and alkali-silica reaction products are extremely sensitive to humidity. Consequently, characterization techniques that require high vacuum or drying, as many existing techniques do, are not particularly appropriate for the study of the alkali-silica reaction because artefacts are introduced. Environmental scanning electron micrographs and scanning electron micrographs with energy dispersive X-ray analysis results demonstrate the effect of drying on the morphology and chemical composition of the alkali-silicate reaction gel. Thus, the impetus for this research was the need to observe and characterize the alkali-silica reaction and its gel product on a microscopic level in a wet environment (i.e. without introducing artefacts due to drying). Only soft X-ray transmission microscopy provides the required high spatial resolution needed to observe the reaction process in situ. The alkali-silica reaction can be observed over time, in a wet condition, and at normal pressures, features unavailable with most other high resolution techniques. Soft X-rays also reveal information on the internal structure of the sample. The purpose of this paper is to present research, obtained using transmission soft X-ray microscopy, on the effect of concrete pore solution cations, namely sodium and calcium, on the product formed as a result of alkali attack. Alkali-silicate reaction (ASR) gel was obtained from the FURNAS Dam in Minas Gerais, Brazil. Images of the ASR gel in sodium hydroxide indicated dissolution and repolymerization of the silicate into a less dense form, demonstrating the expansive nature of the gel when exposed to alkalis. In the calcium hydroxide solution, ASR gel, silica fume, and chemical grade silica gel each reacted with the calcium ions in solution to produce a calcium silicate hydrate precursor with a lathlike, branching morphology. The distinctive spherulitic microstructure formed during this reaction was identified as the 'sheaf of wheat' morphology, previously described in the literature. In addition, the development of the sheaf of wheat morphology was documented over time. These results suggest that of the cations studied in this investigation, it is the alkalis in concrete pore solution that produce the expansive ASR gel, while reaction with calcium ions does not result in expansion or damage to the concrete structure. More broadly, these results demonstrate the advantage of transmission soft X-ray microscopy for the study of the alkali-silica reaction, indicating the value of this technique for further studies in concrete technology.
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Affiliation(s)
- KE Kurtis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Abstract
Humic substances (HSs) are the natural organic polyelectrolytes formed from the biochemical weathering of plant and animal remains. Their macromolecular structure and chemistry determine their role in biogeochemical processes. In situ spectromicroscopic evidence showed that the HS macromolecular structures (size and shape) vary as a function of HS origin (soil versus fluvial), solution chemistry, and the associated mineralogy. The HSs do not simply form coils in acidic or strong electrolyte solutions and elongated structures in dilute alkaline solutions. The macromolecular structural changes of HSs are likely to modify contaminant solubility, biotransformation, and the carbon cycle in soils and sediments.
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Affiliation(s)
- SC Myneni
- Earth Sciences Division, Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Agriculture Experimental Station, University o
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Yeung J, Brown JT, Nair A, Meites E, Coppel RL, Mohandas N, Meyer-Ilse W, Magowan C. X-ray microscopic visualization of specific labeling of adhesive molecule CD36 and cytoadherence by Plasmodium falciparum infected erythrocytes. Res Commun Mol Pathol Pharmacol 1998; 99:245-58. [PMID: 9591321] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the cytoadherence of Plasmodium falciparum infected erythrocytes to target cells that express CD36 by soft x-ray microscopy. Using immunogold beads enhanced with silver, we localized CD36 on the surface of intact melanoma cells and throughout Triton extracted melanoma cells. We examined the orientation of parasites within erythrocytes that bound to target cells, and the interactions between the red cell membrane and the target cell, and we confirmed that fibrillar structures on the surface of melanoma and endothelial cells can be involved in the association between infected erythrocytes and melanoma cells or endothelial cells.
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Affiliation(s)
- J Yeung
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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Magowan C, Brown JT, Liang J, Heck J, Coppel RL, Mohandas N, Meyer-Ilse W. Intracellular structures of normal and aberrant Plasmodium falciparum malaria parasites imaged by soft x-ray microscopy. Proc Natl Acad Sci U S A 1997; 94:6222-7. [PMID: 9177198 PMCID: PMC21030 DOI: 10.1073/pnas.94.12.6222] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Soft x-ray microscopy is a novel approach for investigation of intracellular organisms and subcellular structures with high spatial resolution. We used x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes and in infected erythrocytes treated with cysteine protease inhibitors. Investigations in normal red blood cells enabled us to recognize anomalies in parasite structures resulting from growth under unfavorable conditions. X-ray microscopy facilitated detection of newly elaborated structures in the cytosol of fixed, unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology. In cysteine protease inhibitor-treated, infected erythrocytes, high concentrations of material were detected in abnormal digestive vacuoles and aggregated at the parasite plasma membrane. We have demonstrated that an abnormal host erythrocyte skeleton affects structural development of parasites and that this aberrant development can be detected in the following generation when parasites from protein 4.1-deficient red blood cells infect normal erythrocytes. This work extends our current understanding of the relationship between the host erythrocyte membrane and the intraerythrocytic malaria parasite by demonstrating for the first time that constituents of the erythrocyte membrane play a role in normal parasite structural development.
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Affiliation(s)
- C Magowan
- Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA
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Brown JT, Ellis L, Guerrina ML, Paxton DM, Poleno P. The relationship between the frequency of exercise and the age of onset of sexual intercourse in adolescent females. Nurse Pract 1997; 22:16-8, 171. [PMID: 9055314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
Tumor cell invasion surrounding intracerebrally implanted tumors in rats was studied by comparing the results of cerebral microangiography, fluorescence imaging of blood-brain barrier (BBB) disruption and histopathology. Each comparison was on subsequent sections taken from an initial 1 mm coronal slice of brain taken through the cell injection site containing tumor using the RT-2 glioma model. Tumor extension was assessed at 3, 5, 7 and 9 days after tumor implantation. Analysis of the brain adjacent to tumor shows that the actual tumor cell invasion area is greater than the area of BBB disruption at later stages of tumor growth and the extent of tumor vascularization lies well within the area defined by the extent of tumor cell invasion. Furthermore, this study found that the size of the area of tumor cell invasion remains relatively stable in proportion to the solid tumor mass at various stages of growth such that the area of tumor invaded brain was approximately 2.5 times greater than the area outlined by solid tumor mass. We conclude that measurement of the solid tumor mass, tumor vascular area and region of blood-brain barrier disruption due to tumor, grossly underestimate the total tumor volume. Therapies aimed at controlling glial tumor growth must, therefore, include normal appearing regions of brain peripheral to the abnormal region defined as tumor and tumor invaded brain as defined by radiographic and imaging studies.
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Affiliation(s)
- Y Ji
- Milton S. Hershey Medical Center, Pennsylvania State University, Hershey, USA
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Brown JT. A piece of my mind. A jack of all trades. JAMA 1996; 276:264. [PMID: 8656522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Brown JT, Miller A. Peroneal tenosynovitis following acute gonococcal infection. Am J Orthop (Belle Mead NJ) 1996; 25:445-7. [PMID: 8798987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A 17-year-old adolescent girl presented with tenosynovitis of the peroneal tendons following diagnosis and treatment of an endocervical gonococcal infection. The need for careful history in any sexually active adolescent is emphasized. Acute peroneal tenosynovitis, although not previously cited in the literature, can occur and should be suspected.
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Affiliation(s)
- J T Brown
- Community General Osteopathic Hospital, Harrisburg, Pennsylvania, USA
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Abstract
The widespread acceptance of photodynamic therapy (PDT), a potential adjuvant brain tumor therapy under clinical evaluation since 1980, has been partially restrained by its potential toxicity toward normal brain tissue. This study examined PDT-produced injury of normal rat brain as a function of photosensitizer dose. Brain injury was characterized by correlating measurements of the area of cerebral edema using T2-weighted magnetic resonance images, measurement of brain water content at the lesion site, microscopic examination of histological sections through the PDT lesion, and by evaluation of the area of blood brain barrier (BBB) disruption using computerized morphometric analysis of the region of Evans blue (EB) dye-labelled albumin extravasation. Monochromatic red light (630 nm) was delivered intracerebrally using a 5-mm-long cylindrical, diffusion-tip optical fiber at a constant energy dose of 15 joules. A Photofrin dose of 2 mg/kg of body weight produced a transient breakdown in the blood brain barrier around the site of the implanted optical fiber demonstrated by magnetic resonance imaging (MRI), extravasation of EB dye and pallor on hematoxylin and eosin-stained microscopic tissue sections. A much larger area of BBB disruption was seen at a dose of 4 mg/kg of Photofrin, and this drug dose resulted in significant permanent brain injury. In this model, a Photofrin dose of 4 mg/kg body weight is not tolerated by the normal brain.
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Affiliation(s)
- Y Ji
- Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
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Weinberger M, Saunders AF, Bearon LB, Gold DT, Brown JT, Samsa GP, Loehrer PJ. Physician-related barriers to breast cancer screening in older women. J Gerontol 1992; 47 Spec No:111-7. [PMID: 1430872] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Despite evidence that annual mammographic screening in women 50 years and older reduces mortality, surveys of physicians and patients have repeatedly demonstrated that annual screening mammography is not performed. The fundamental question addressed in this chapter is: If the assumption is made that the scientific evidence supports the use of mammography, what, then, are physician-related barriers to mammographic screening of elderly women? Using a model that classifies barriers to implementing prevention protocols into three categories (predisposing, enabling, and reinforcing factors), literature is reviewed to help identify reasons for low mammographic screening rates, especially in elderly women. This article concludes with a discussion of strategies that may help overcome barriers to mammographic screening in elderly women.
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Abstract
OBJECTIVE To estimate the frequency with which patients are incorrectly used as the unit of analysis among statistical calculations in published studies of physicians' patient care behavior. DESIGN Retrospective review of studies published during 1980-1990. ARTICLES: 54 articles retrieved by a computerized search using medical subject headings for physicians and study characteristics. Article selection criteria included the requirement that the physician should have been the correct unit of analysis. INTERVENTION Presence of the error was determined by consensus using published criteria. MAIN RESULTS The error was present in 38 articles (70%). The number of study physicians was reported in 35 articles (65%). The error was found in 57% of articles that reported the number of study physicians and in 95% of those that did not. The error rate was not lower among articles published more recently nor among those published in journals with higher rates of article citations in the medical literature. CONCLUSION The unit of analysis error occurs frequently and can generate artificially low p values. Failure to report the number of study physicians can be a clue that this type of error has been made.
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Affiliation(s)
- G W Divine
- Department of Community and Family Medicine, Duke University, Durham, NC
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Abstract
The effectiveness of intratumoral photoradiation in photodynamic therapy (PDT) using a polyporphyrin photosensitizer was studied in the RT-2 rat glioma model. One week after intracerebral implantation of RT-2 cells, experimental rats received a single i.p. injection of 2 mg/kg of Photofrin. After administration of the photosensitizer (48 h), the tumors were partially resected and the exposed cavity was irradiated with 15 J of laser light at a wavelength of 630 nm. Further treatment with a large craniectomy significantly enhanced rat survival. Control rats which received no photosensitizer but were treated with surgery, alone or in combination with laser irradiation, succumbed from early tumor recurrence. Photodynamic therapy without decompressive surgery resulted in hemorrhagic infarction of residual tumor and adjacent brain with focal cerebral edema which resulted in cerebral herniation and early death. Our results indicate that photodynamic therapy is effective in treating residual brain tumor but at the expense of brain tissue surrounding the tumor. Unless relieved, intracranial pressure from photodynamic therapy-associated cerebral edema in this animal model resulted in shortened survival.
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Affiliation(s)
- Y Ji
- Division of Neurosurgery, University of North Carolina, Chapel Hill 27599-7060
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Abstract
Photofrin (a polyporphyrin mixture) distribution in a rat glioma model was studied in relation to changes in the blood brain barrier (BBB). At selected intervals after intraperitoneal injection of Photofrin, the concentration of polyporphyrins (PP) and Evans Blue Dye, an indicator of BBB permeability, were determined for tumor, brain adjacent to tumor (BAT), and normal brain tissue. Contrary to earlier reports of maximal accumulation at 4-24 hours, tumor levels of PP increased throughout the 96 hour measurement period. During the early stages of tumor development, PP uptake by tumor appeared to be less correlated to BBB disruption. We conclude that passive diffusion through an incompetent BBB does not completely explain PP accumulation in tumor tissue.
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Affiliation(s)
- Y Ji
- Division of Neurological Surgery, University of North Carolina, Chapel Hill 27599-7060
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Abstract
A case of traumatic spondylolisthesis of C6 and C7 is presented. The mechanism of injury and the therapeutic implications are discussed.
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Affiliation(s)
- R A Rovin
- Division of Neurological Surgery, Northwestern University Medical School, Chicago, Illinois
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Abstract
The effect on normal brain of continuous interstitial laser irradiation at 630 nm through an implanted cylindrical-shape, diffusion-tipped optical fiber was studied in the rat. Brain water content in the laser irradiation area (LIA) and Evans blue (EB) dye content in selected areas of the brain were measured for different laser power outputs from 0 to 250 mW after 5 minutes of photoradiation. The degree and nature of tissue damage was examined histologically and correlated with the laser power level. There is significant brain damage, blood brain barrier (BBB) disruption, and brain edema in LIA for laser power outputs in excess of 100 mW from the diffusion tip (p less than 0.001). Brain edema in the LIA is strongly correlated with BBB disruption indicated by the presence of EB. Histologically, the cortical surface was more susceptible than deeper white matter regions to interstitial laser irradiation. Possible indirect mechanisms of brain injury from interstitial laser irradiation are discussed.
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Affiliation(s)
- Y Ji
- Division of Neurological Surgery, University of North Carolina, Chapel Hill 27599-7060
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Brown JT, Wong JG. The Duke Minority Medical Student Summer Fellowship: one program's attempt to attract minority residents. Am J Med Sci 1991; 302:124-8. [PMID: 1897558 DOI: 10.1097/00000441-199108000-00011] [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] [Indexed: 12/29/2022]
Abstract
Despite numerous Federal and private funding programs aimed at increasing the numbers of underrepresented minorities in medicine, the participation of minority groups in the medical profession remains low and shows little sign of improvement. With the goal of improving minority representation in our primary care residency program, the Minority Medical Student Summer Fellowship started in July 1990. The program's purpose is to give minority medical students positive exposure to primary care and attract them back for residency training. In this four-week elective, students participate in seminars with our primary care residents, see patients in a variety of clinics, and complete a project. Key implementation issues include support of the medicine chairman and dean, funding, and malpractice coverage for the students. Program evaluation from the first two students rated the clinic experiences higher than the seminar sessions and the independent project. Both students stated our fellowship made them more likely to train at this medical center should they enter a primary care program. Implications for other programs are listed.
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Affiliation(s)
- J T Brown
- Division of General Internal Medicine, Duke University Medical Center, Durham, North Carolina 27710
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Frazier LM, Brown JT, Divine GW, Fleming GR, Philips NM, Siegal WC, Khayrallah MA. Can physician education lower the cost of prescription drugs? A prospective, controlled trial. Ann Intern Med 1991; 115:116-21. [PMID: 2058859 DOI: 10.7326/0003-4819-115-2-116] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [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: 12/30/2022] Open
Abstract
OBJECTIVE To determine whether an educational program featuring a drug cost manual can assist physicians in reducing their patients' out-of-pocket prescription drug expenses. DESIGN Prospective controlled trial. SETTING A general internal medicine-teaching clinic in a university hospital. PARTICIPANTS Fifty-one medical interns. INTERVENTION Thirty-one interns received a manual of comparative drug prices annotated with prescribing advice, two feedback reports, and weekly cost-oriented prescribing reminders. A control group concurrently participated in a manual-based educational program on cholesterol management. MEASUREMENTS Copies of 3012 prescriptions written over 8 months were analyzed. MAIN RESULTS Intervention group physicians prescribed less expensive drugs within classes of drugs. The change in drug price score per prescription was -0.15 (95% Cl, -0.27 to -0.04; P = 0.01). A score of 3 was assigned to the most expensive, 2 was assigned to intermediate-priced, and 1 was assigned to the least expensive drug or drugs in the class. An increase of 0.74 months' (Cl, 0.49 to 0.98; P less than 0.001) supply of medication was dispensed per prescription, reducing dispensing fees. The program was well accepted by the physicians. CONCLUSION This relatively simple educational intervention can help physicians to reduce their patients' drug expenses and may serve as a model for incorporating cost information into the routine practice of medicine.
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Affiliation(s)
- L M Frazier
- Duke University Medical Center, Durham, North Carolina
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Abstract
OBJECTIVE To measure the content of oral outpatient case presentations and to assess the correlation of objective assessments of this content with subjective ratings provided by the clinic attending physician. DESIGN Blinded assessment via audiotape of 36 oral case presentations of new patient evaluations by 23 medical residents. SETTING Outpatient general medical clinic. PARTICIPANTS Duke University Medical Center medical residents during their outpatient rotation. MEASUREMENTS AND MAIN RESULTS Important deficiencies were found in oral case presentation content. Specifically, psychosocial data were often missing (employment history) was mentioned in 28% of presentations; illicit drug use, in 17%; household social structure, in 11%; sexual history, in 6%). An assessment and a plan were mentioned only 56% and 69% of the time, respectively. No correlation was seen between an objective "content score" and the attending physician's subjective rating of the quality of the presentation (r = 0.09). CONCLUSIONS 1) The outpatient care presentation can be quantitatively assessed in a simple, straightforward manner; 2) outpatient case presentations have important deficiencies in content; and 3) preceptors' evaluations of case presentations may be based upon factors other than content of the presentation.
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Affiliation(s)
- J T Kihm
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
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