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Barker EN, Payne JR, Wilson H. Control line failure in Angiostrongylus vasorum point-of-care serology test in dogs with angiostrongylosis due to suspected hook effect. J Small Anim Pract 2024; 65:243-250. [PMID: 38438331 DOI: 10.1111/jsap.13716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 01/29/2024] [Accepted: 02/07/2024] [Indexed: 03/06/2024]
Abstract
OBJECTIVES Angiostrongylosis is a significant differential for a diverse range of clinical signs in dogs, many of whom present acutely and sometimes with fatal consequences. Point-of-care diagnostic assays include a commercially available Angiostrongylus vasorum qualitative direct lateral flow assay. MATERIALS AND METHODS Case records from one referral centre from dogs with an invalid A. vasorum lateral flow assay, comprising an absent control line alongside a visible test line, were reviewed. As control line failure was hypothesised to be due to antigen excess; where available the A. vasorum lateral flow assay was repeated using dilutions of the original serum. RESULTS Six dogs had an invalid A. vasorum lateral flow assay result. Five dogs had presented with acute-onset, severe clinical disease consistent with angiostrongylosis, and one dog was a clinically healthy in-contact. Clinical suspicion of angiostrongylosis was confirmed using alternative diagnostic testing and/or response to treatment. Repetition of the A. vasorum lateral flow assay, in four cases, using diluted plasma (10% to 12.5% v/v) resulted in the appearance of a control line alongside the visible test line. CLINICAL SIGNIFICANCE A heavy burden of A. vasorum infection resulting in angiostrongylosis should be suspected in dogs with compatible clinical signs and an invalid A. vasorum lateral flow assay result due to control failure alongside a visible test line. Repetition of the test with a diluted serum may be considered to account for the hook effect, also known as the postzone phenomenon, as a possible cause.
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Affiliation(s)
- E N Barker
- Langford Vets, Small Animal Referral Hospital, Langford House, Langford, BS40 5DU, UK
- Bristol Veterinary School, University of Bristol, Langford House, Langford, BS40 5DU, UK
| | - J R Payne
- Langford Vets, Small Animal Referral Hospital, Langford House, Langford, BS40 5DU, UK
| | - H Wilson
- Langford Vets, Small Animal Referral Hospital, Langford House, Langford, BS40 5DU, UK
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Novo Matos J, Payne JR, Mullins J, Luis Fuentes V. Isolated discrete upper septal thickening in a non-referral cat population of senior and young cats. J Vet Cardiol 2023; 50:39-50. [PMID: 37924557 DOI: 10.1016/j.jvc.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 09/27/2023] [Accepted: 09/29/2023] [Indexed: 11/06/2023]
Abstract
INTRODUCTION/OBJECTIVES Discrete upper septal thickening (DUST) is a phenotype of elderly people. The cardiac phenotype in senior cats has been incompletely described. We aimed to characterize the echocardiographic phenotype of senior cats, specifically to determine prevalence of DUST and hypertrophic cardiomyopathy (HCM). ANIMALS One hundred and forty-nine healthy, normotensive cats. MATERIALS AND METHODS Prospective cross-sectional study. Senior (≥9 years) and young (<6 years) cats were recruited from non-referral population. We defined DUST as an isolated basilar septal bulge, and HCM as left ventricular wall thickness ≥6 mm. An interventricular septum ratio (basal-to-mid septal thickness ratio) was calculated. We assessed for associations between clinical and echocardiographic variables and DUST. Data are presented as mean (±SD), median (range), or frequency (percentage). RESULTS One-hundred and two senior and 47 young cats were enrolled. Aortoseptal angle (AoSA) was steeper in senior cats (137° (±14.5) vs. 145° (±12.3) in young cats, P=0.002). Eighteen cats had DUST (18/149, 12%), fourteen senior, and four young cats (P=0.4). Cats with DUST had steeper AoSA (125° (±8.3) vs. 142° (±13.7), P<0.0001) and higher interventricular septum ratio (1.4 (1.2-2.0) vs. 1.0 (0.7-1.8)). Univariable analysis showed decreased odds of DUST with greater AoSA (OR 0.9, P<0.0001), age was not associated with DUST. Twenty-nine senior cats had HCM (28.4%). DISCUSSION/CONCLUSIONS Prevalence of DUST was 12%. There was no association between age and DUST. Smaller/steeper AoSA was the main factor associated with DUST. There was a high prevalence of HCM in this senior population.
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Affiliation(s)
- J Novo Matos
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, AL9 7TA, UK.
| | - J R Payne
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, BS40 5DU, Langford, UK
| | - J Mullins
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, AL9 7TA, UK
| | - V Luis Fuentes
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, AL9 7TA, UK
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McGrath C, Dixon A, Hirst C, Bode EF, DeFrancesco T, Fries R, Gordon S, Hogan D, Martinez Pereira Y, Mederska E, Ostenkamp S, Sykes KT, Vitt J, Wesselowski S, Payne JR. Pacemaker-lead-associated thrombosis in dogs: a multicenter retrospective study. J Vet Cardiol 2023; 49:9-28. [PMID: 37541127 DOI: 10.1016/j.jvc.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 06/18/2023] [Accepted: 06/25/2023] [Indexed: 08/06/2023]
Abstract
INTRODUCTION Pacemaker implantation is the treatment of choice for clinically relevant bradyarrhythmias. Pacemaker-lead-associated thrombosis (PLAT) occurs in 23.0-45.0% of people with permanent transvenous pacemakers. Serious thromboembolic complications are reported in 0.6-3.5%. The incidence of PLAT in dogs is unknown. ANIMALS, MATERIALS AND METHODS multicenter retrospective study of seven centers with 606 client-owned dogs undergoing permanent pacemaker implantation between 2012 and 2019. 260 dogs with a transvenous pacemaker with echocardiographic follow-up, 268 dogs with a transvenous pacemaker without echocardiographic follow-up and 78 dogs with an epicardial pacemaker. RESULTS 10.4% (27/260) of dogs with transvenous pacemakers and echocardiographic follow-up had PLAT identified. The median time to diagnosis was 175 days (6-1853 days). Pacemaker-lead-associated thrombosis was an incidental finding in 15/27 (55.6%) dogs. Of dogs with a urine protein:creatinine ratio measured at pacemaker implantation, dogs with PLAT were more likely to have proteinuria at pacemaker implantation vs. dogs without PLAT (6/6 (100.0%) vs. 21/52 (40.4%), P=0.007). Urine protein:creatinine ratio was measured in 12/27 (44.4%) dogs at PLAT diagnosis, with proteinuria identified in 10/12 (83.3%) dogs. Anti-thrombotic drugs were used following the identification of PLAT in 22/27 (81.5%) dogs. The thrombus resolved in 9/15 (60.0%) dogs in which follow-up echocardiography was performed. Dogs with PLAT had shorter survival times from implantation compared to those without PLAT (677 days [9-1988 days] vs. 1105 days [1-2661 days], P=0.003). CONCLUSIONS Pacemaker-lead-associated thrombosis is identified in 10.4% (27/260) of dogs following transvenous pacing, is associated with proteinuria, can cause significant morbidity, and is associated with reduced survival times.
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Affiliation(s)
- C McGrath
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, Langford, Bristol, BS40 5DU, United Kingdom
| | - A Dixon
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, Langford, Bristol, BS40 5DU, United Kingdom
| | - C Hirst
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, Langford, Bristol, BS40 5DU, United Kingdom
| | - E F Bode
- Small Animal Teaching Hospital, Institute of Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Wirral, CH64 7TE, United Kingdom
| | - T DeFrancesco
- College of Veterinary Medicine, North Carolina State Veterinary Hospital, 1052 William Moore Dr., Raleigh, NC, 27607, USA
| | - R Fries
- University of Illinois Veterinary Teaching Hospital, 1008 W Hazelwood Dr., Urbana, IL, 61802, USA
| | - S Gordon
- Texas A&M University Veterinary Medical Teaching Hospital, 408 Raymond Stotzer Pkwy, College Station, TX, 77845, USA
| | - D Hogan
- Purdue University Small Animal Hospital, West Lafayette, Indiana LYNN, 625 Harrison St., West Lafayette, IN, 47907, USA
| | - Y Martinez Pereira
- Hospital for Small Animals, The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, United Kingdom
| | - E Mederska
- Small Animal Teaching Hospital, Institute of Veterinary Science, University of Liverpool, Leahurst Campus, Chester High Road, Neston, Wirral, CH64 7TE, United Kingdom
| | - S Ostenkamp
- Purdue University Small Animal Hospital, West Lafayette, Indiana LYNN, 625 Harrison St., West Lafayette, IN, 47907, USA
| | - K T Sykes
- Texas A&M University Veterinary Medical Teaching Hospital, 408 Raymond Stotzer Pkwy, College Station, TX, 77845, USA
| | - J Vitt
- University of Illinois Veterinary Teaching Hospital, 1008 W Hazelwood Dr., Urbana, IL, 61802, USA
| | - S Wesselowski
- Texas A&M University Veterinary Medical Teaching Hospital, 408 Raymond Stotzer Pkwy, College Station, TX, 77845, USA
| | - J R Payne
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, Langford, Bristol, BS40 5DU, United Kingdom.
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Novo Matos J, Sargent J, Silva J, Payne JR, Seo J, Spalla I, Borgeat K, Loureiro J, Pereira N, Simcock IC, Hutchinson JC, Arthurs OJ, Luis Fuentes V. Thin and hypokinetic myocardial segments in cats with cardiomyopathy. J Vet Cardiol 2023; 46:5-17. [PMID: 36893525 DOI: 10.1016/j.jvc.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 01/30/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
INTRODUCTION/OBJECTIVES Thin and hypokinetic myocardial segments (THyMS) represent adverse ventricular (LV) remodeling in human hypertrophic cardiomyopathy. We describe the echocardiographic features and outcome in cats with THyMS, and in a subpopulation, the echocardiographic phenotype before LV wall thinning was detected (pre-THyMS). ANIMALS Eighty client-owned cats. MATERIALS AND METHODS Retrospective multicenter study. Clinical records were searched for cats with THyMS, defined as LV segment(s) with end-diastolic wall thickness (LVWT) <3 mm and hypokinesis in the presence of ≥one LV segment(s) with LVWT >4 mm and normal wall motion. When available, echocardiograms pre-THyMS were assessed. Survival time was defined as time from first presentation with THyMS to death. RESULTS Mean thickest LV wall segment (MaxLVWT) was 6.1 mm (95% CI 5.8-6.4 mm) and thinnest (MinLVWT) was 1.7 mm (95% CI 1.6-1.9 mm). The LV free wall was affected in 74%, apex in 13% and septum in 5%. Most cats (85%) presented with heart failure and/or arterial thromboembolism. Median circulating troponin I concentration was 1.4 ng/mL ([range 0.07-180 ng/mL]). Prior echocardiography results were available for 13/80 cats, a mean of 2.5 years pre-THyMS. In segments subsequently undergoing thinning, initial MaxLVWT measured 6.7 mm (95% CI 5.8-7.7 mm) vs. 1.9 mm (95% CI 1.5-2.4 mm) at last echocardiogram (P<0.0001). Survival data were available for 56/80 cats, median survival time after diagnosing THyMS was 153 days (95% CI 83-223 days). Cardiac histopathology in one cat revealed that THyMS was associated with severe transmural scarring. CONCLUSIONS Cats with THyMS had advanced cardiomyopathy and a poor prognosis.
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Affiliation(s)
- J Novo Matos
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, CB3 0ES, Cambridge, UK; Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, London, UK.
| | - J Sargent
- Southern Counties Veterinary Specialists, Unit 6, Forest Corner Farm, Hangersley, BH24 3JW, Ringwood, Hampshire, UK
| | - J Silva
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, CB3 0ES, Cambridge, UK; North Downs Specialist Referrals, The Friesian Buildings 3 & 4, Brewer Street, RH1 4QP, Bletchingley, Surrey, UK
| | - J R Payne
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, BS40 5DU, Langford, UK
| | - J Seo
- Animal Referral Centre, 224 Albany Highway, Schnapper Rock, 0632, Auckland, New Zealand
| | - I Spalla
- Ospedale Veterinario San Francesco, Via Feltrina, 29, 31038, Castagnole, Milan, Italy
| | - K Borgeat
- Langford Vets Small Animal Referral Hospital, University of Bristol, Langford House, BS40 5DU, Langford, UK
| | - J Loureiro
- North Downs Specialist Referrals, The Friesian Buildings 3 & 4, Brewer Street, RH1 4QP, Bletchingley, Surrey, UK
| | - N Pereira
- Freelance Cardiology, Salstrasse 92, 8400, Winterthur, Switzerland
| | - I C Simcock
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - J C Hutchinson
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - O J Arthurs
- Department of Clinical Radiology, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; UCL Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, Great Ormond Street, WC1N 3JH, London, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Hospital Biomedical Research Centre, London, UK
| | - V Luis Fuentes
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire, AL9 7TA, London, UK
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Seo J, Matos JN, Payne JR, Fuentes VL, Connolly DJ. Anterior mitral valve leaflet length in cats with hypertrophic cardiomyopathy. J Vet Cardiol 2021; 37:62-70. [PMID: 34610570 DOI: 10.1016/j.jvc.2021.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 08/30/2021] [Accepted: 09/06/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Anterior mitral valve leaflet (AMVL) elongation is a recognised feature of hypertrophic cardiomyopathy (HCM). However, whether AMVL elongation precedes left ventricular hypertrophy in cats is currently unknown. The aim of this study was to explore the risk of developing an HCM phenotype in cats with an elongated AMVL. ANIMALS FIFTY-FIVE APPARENTLY HEALTHY CATS WITH A NORMAL BASELINE ECHOCARDIOGRAM AND A FOLLOW-UP ECHOCARDIOGRAM AT >ONE YEAR. MATERIALS AND METHODS This was a retrospective longitudinal study. Cats at the baseline were grouped based on whether or not they developed an HCM phenotype at follow-up. AMVL length and left atrial and left ventricular dimensions were measured from two-dimensional images. RESULTS The median follow-up period of the study population was 5.4 years (25th and 75th quartile, 2.7-6.7 years). During this time, 17 cats (30.9%) developed an HCM phenotype. At the baseline, cats that subsequently developed an HCM phenotype had greater AMVL length (9.4 mm [25th and 75th quartile, 9.0-10.6 mm] vs. 8.5 mm [25th and 75th quartile, 7.6-9.1 mm], P < 0.0001) and maximal left ventricular wall thickness (4.5 mm [25th and 75th quartile, 4.1-4.7 mm] vs. 4.0 mm [25th and 75th quartile, 3.7-4.6 mm], P = 0.007) than those that did not. Multiple logistic regression analysis confirmed that both baseline variables were independent predictors for development of an HCM phenotype. CONCLUSIONS The AMVL length was greater in cats that subsequently developed left ventricular hypertrophy. Further studies investigating the clinical application of AMVL in the natural history of feline HCM are warranted.
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Affiliation(s)
- J Seo
- Animal Referral Centre, Auckland, New Zealand; School of Veterinary Science, Massey University, Palmerston North, New Zealand; Clinical Science and Services, Royal Veterinary College, Hertfordshire, United Kingdom.
| | - J Novo Matos
- Clinical Science and Services, Royal Veterinary College, Hertfordshire, United Kingdom; Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - J R Payne
- Langford Vets Small Animal Referral Hospital, University of Bristol, Bristol, United Kingdom
| | - V Luis Fuentes
- Clinical Science and Services, Royal Veterinary College, Hertfordshire, United Kingdom
| | - D J Connolly
- Clinical Science and Services, Royal Veterinary College, Hertfordshire, United Kingdom
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Gomart S, Allaway D, Harrison M, Dickson D, Seo J, Ferasin L, Payne JR, Hezzell MJ, Borgeat K. Long-term biological variability and the generation of a new reference interval for plasma N-terminal pro-B-type natriuretic peptide in Labrador retrievers. J Small Anim Pract 2020; 61:368-373. [PMID: 32297329 DOI: 10.1111/jsap.13136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 02/26/2020] [Accepted: 02/29/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES First, to investigate the biological variability of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in healthy Labrador retrievers and compare this with current laboratory recommendations for dilated cardiomyopathy screening. Second, to calculate a breed-specific reference interval and validate it in a retrospective cohort. MATERIALS AND METHODS Plasma NT-proBNP was measured in 51 clinically healthy Labrador retrievers at 0, 2, 4, 6 and 8 weeks. Coefficient of variation for individual dogs over time, the coefficient of variation for the group at each time point and the index of individuality were calculated. A reference interval was derived and tested on a clinical dataset available from four UK cardiology referral centres. RESULTS Median NT-proBNP was 865 pmol/L (315 to 2064 pmol/L). Mean individual coefficient of variation was 19% (95% CI: 16 to 21%) and group coefficient of variation was 43% (95% CI: 41 to 46%), with index of individuality at 0.44. The breed-specific reference interval was 275 to 2100 pmol/L. In the validation group, 93% of NT-proBNP measurements from healthy dogs were within the reference interval. NT-proBNP measurements exceeded the reference interval in 82% of dogs with dilated cardiomyopathy. The upper bound of the reference interval (2100 pmol/L) had a positive predictive value of 90% and a negative predictive value of 87% for identification of dilated cardiomyopathy in this population. CLINICAL SIGNIFICANCE Breed-specific reference intervals might improve the diagnostic accuracy of NT-proBNP measurement. Applying the currently recommended general cut-off value to Labradors is likely to result in frequent false positives and diagnosis would be improved by application of the new breed-specific reference interval calculated here.
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Affiliation(s)
- S Gomart
- Langford Vets, University of Bristol, Bristol, UK
| | - D Allaway
- MARS PetCare Ltd, Waltham Centre for Pet Nutrition, Waltham, UK
| | - M Harrison
- MARS PetCare Ltd, Waltham Centre for Pet Nutrition, Waltham, UK
| | | | - J Seo
- Royal Veterinary College, London, UK
| | - L Ferasin
- Lumbry Park Veterinary Specialists, Alton, UK
| | - J R Payne
- Langford Vets, University of Bristol, Bristol, UK
| | - M J Hezzell
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - K Borgeat
- Langford Vets, University of Bristol, Bristol, UK
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Abstract
Aortic stenosis affects 0.028% of cats in a shelter population, with valvular aortic stenosis compromising almost half of these cases. Of congenital heart diseases reported in cats, aortic stenosis is the second most common one, affecting 17% of these cases. Existing literature on valvular aortic stenosis is scant, and thus, presentation and prognosis of affected animals is poorly understood. In this case series, we describe three cats with confirmed valvular aortic stenosis. All cases were diagnosed echocardiographically, and all three had visible aortic valve leaflet fusion and a poststenotic dilation of the ascending aorta. Congestive heart failure developed in all three cases, and prognosis was poor. This case report highlights the existence of aortic valve dysplasia in cats and may allow clinicians a better understanding of the clinical presentation of this congenital abnormality.
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Affiliation(s)
- C E Watson
- Langford Vets, University of Bristol, Stock Lane, Lower Langford, North Somerset, BS40 5DU, United Kingdom
| | - J R Payne
- Langford Vets, University of Bristol, Stock Lane, Lower Langford, North Somerset, BS40 5DU, United Kingdom
| | - K Borgeat
- Langford Vets, University of Bristol, Stock Lane, Lower Langford, North Somerset, BS40 5DU, United Kingdom.
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Spalla I, Payne JR, Borgeat K, Pope A, Fuentes VL, Connolly DJ. Mitral Annular Plane Systolic Excursion and Tricuspid Annular Plane Systolic Excursion in Cats with Hypertrophic Cardiomyopathy. J Vet Intern Med 2017; 31:691-699. [PMID: 28370313 PMCID: PMC5435071 DOI: 10.1111/jvim.14697] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 01/03/2017] [Accepted: 02/23/2017] [Indexed: 11/29/2022] Open
Abstract
Background Left ventricular (LV) systolic dysfunction is associated with increased risk of death in cats with hypertrophic cardiomyopathy (HCM). Mitral and tricuspid annular plane systolic excursion (MAPSE and TAPSE, respectively) are measures of longitudinal systolic function and are reduced in human patients with HCM. Hypotheses Cats with HCM have lower MAPSE and TAPSE compared to control cats; lower MAPSE and TAPSE are associated with the presence of congestive heart failure (CHF) and reduced survival time. Animals 64 cats with HCM and 27 healthy cats. Forty‐five cats with HCM were not showing clinical signs, and 19 had CHF. Methods Retrospective study. Anatomic M‐mode from the left apical 4‐chamber view was used to record MAPSE from the free wall (MAPSE FW) and septum (MAPSE IVS) and TAPSE. Results Compared to controls, cats with HCM had lower MAPSE IVS (controls 5.2 [4.6–5.6] mm, asymptomatic HCM 4.7 [4.1–5.2] mm, HCM with CHF 2.6 [2.5–3.2] mm, P < .001), MAPSE FW (controls 5.9 [5.3–6.2] mm, asymptomatic HCM 4.7 [4.1–5.1] mm, HCM with CHF 2.8 [2.4–3.2] mm) and TAPSE (controls 8.6 [7.4–10.2] mm, asymptomatic HCM 7.2 [6.3–8.2] mm, HCM with CHF 4.6 [4.1–5.4] mm), with the lowest in the CHF group. Univariate survival analysis showed a shorter survival in cats displaying lower MAPSE IVS, MAPSE FW, and TAPSE. Conclusions and Clinical Importance MAPSE and TAPSE were lower in cats with HCM than in control cats and were lowest in CHF, suggesting that systolic longitudinal dysfunction is present in cats with HCM. MAPSE and TAPSE have potential prognostic significance.
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Affiliation(s)
- I Spalla
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - J R Payne
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK.,Highcroft Veterinary Referrals, Whitchurch, Bristol, UK
| | - K Borgeat
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK.,Highcroft Veterinary Referrals, Whitchurch, Bristol, UK
| | - A Pope
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - V Luis Fuentes
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - D J Connolly
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
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Payne JR, Brodbelt DC, Luis Fuentes V. Blood Pressure Measurements in 780 Apparently Healthy Cats. J Vet Intern Med 2016; 31:15-21. [PMID: 27906477 PMCID: PMC5259628 DOI: 10.1111/jvim.14625] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 10/05/2016] [Accepted: 11/02/2016] [Indexed: 11/30/2022] Open
Abstract
Background Mean systolic blood pressure in apparently healthy cats has been reported as approximately 125 mmHg using direct assessment, but there is greater variability in reported values using indirect assessment. Increasing age and the white‐coat effect are associated with increased systolic blood pressure. Hypothesis/Objectives To report Doppler‐derived blood pressure measurements from a large population of apparently healthy cats and to assess epidemiologic factors associated with recorded blood pressures. Animals A total of 780 cats in rehoming centers enrolled in a screening program for heart murmurs and cardiac disease. Methods Cats were considered healthy based on history and physical examination. Cats with known hypertension, hyperthyroidism, or clinical signs of systemic disease and pregnant or nursing queens were excluded. After an acclimatization period, systolic blood pressure was measured using the Doppler sphygmomanometry method following the recommendations of the ACVIM Consensus Statement. General linear model analysis was performed to identify factors associated with variation in systolic blood pressure. Results Median (interquartile range, IQR) systolic blood pressure for the group was 120.6 (110.4–132.4) mmHg. Factors significantly associated with higher systolic blood pressure in a general linear model were increased age, increased nervousness, male sex, neutering, or history of being a stray. The model explained 29.2% of the variation in systolic blood pressure. Conclusions and Clinical Importance The age, demeanor, sex, neuter status and history of being a stray should be taken into account when assessing systolic blood pressure in apparently healthy cats.
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Affiliation(s)
- J R Payne
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - D C Brodbelt
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
| | - V Luis Fuentes
- Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, UK
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Payne JR, Borgeat K, Brodbelt DC, Connolly DJ, Luis Fuentes V. Risk factors associated with sudden death vs. congestive heart failure or arterial thromboembolism in cats with hypertrophic cardiomyopathy. J Vet Cardiol 2016; 17 Suppl 1:S318-28. [PMID: 26776589 DOI: 10.1016/j.jvc.2015.09.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 09/17/2015] [Accepted: 09/27/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES To evaluate risk factors associated with different types of cardiac death in cats with hypertrophic cardiomyopathy (HCM). ANIMALS Two hundred fifty-five cats with HCM referred to a veterinary teaching hospital. METHODS This is a retrospective study. Cats with HCM were identified that had either died within 2 years of diagnosis or were known to be alive 2 years after initial examination. Signalment, physical exam, electrocardiographic and echocardiographic data were analyzed separately for association with death due to congestive heart failure (CHF) vs. aortic thromboembolism (ATE) vs. sudden death. RESULTS Within 2 years of follow-up, 23/255 (9.0%) cats had died with ATE, 44/255 (17.3%) cats had died with CHF and 12/255 (4.7%) cats had experienced a sudden death, with 141/255 (55.3%) cats still alive at the end of 2 years. Presence of CHF at presentation and reduced left ventricular fractional shortening (FS%) were independently associated with a CHF death within 2 years of diagnosis. Presence of ATE and reduced left atrial fractional shortening (LA-FS%) were independently associated with dying with ATE within 2 years. No multivariable models were generated for risks of dying a sudden death owing to the low event rate, but syncope at presentation and arrhythmias on auscultation were associated with sudden death on univariable analysis. CONCLUSIONS Asymptomatic cats have a reduced risk of all three types of death. Reduced FS% and a history of CHF independently predict CHF death, and reduced LA-FS% and history of ATE independently predict ATE death. Sudden death is less commonly reported but is associated with syncope.
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Affiliation(s)
- J R Payne
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, United Kingdom
| | - K Borgeat
- Highcroft Veterinary Referrals, 615 Wells Road, Whitchurch, Bristol, BS14 9BE, United Kingdom
| | - D C Brodbelt
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, United Kingdom
| | - D J Connolly
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, United Kingdom
| | - V Luis Fuentes
- Clinical Science and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, United Kingdom.
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Borgeat K, Sherwood K, Payne JR, Luis Fuentes V, Connolly DJ. Plasma cardiac troponin I concentration and cardiac death in cats with hypertrophic cardiomyopathy. J Vet Intern Med 2014; 28:1731-7. [PMID: 25319115 PMCID: PMC4895638 DOI: 10.1111/jvim.12459] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Revised: 07/28/2014] [Accepted: 08/21/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The use of cardiac biomarkers to assist in the diagnosis of occult and symptomatic hypertrophic cardiomyopathy (HCM) in cats has been established. There is limited data describing their prognostic utility in cats with HCM. HYPOTHESIS Circulating concentrations of N-terminal B-type natriuretic peptide (NTproBNP) and cardiac troponin I (cTnI) predict cardiac death in cats with HCM. ANIMALS Forty-one cats diagnosed with HCM at a veterinary teaching hospital, between February 2010 and May 2011. METHODS Prospective investigational study. Plasma samples were collected from cats diagnosed with HCM and concentrations of NTproBNP and cTnI were analyzed at a commercial laboratory. Echocardiographic measurements from the day of blood sampling were recorded. Long-term outcome data were obtained. Associations with time to cardiac death were analyzed using Cox proportional hazards models. RESULTS When controlling for the presence/absence of heart failure and echocardiographic measures of left atrial size and function, cTnI > 0.7 ng/mL was independently associated with time to cardiac death. In univariable analysis, NTproBNP > 250 pmol/L was associated with cardiac death (P = .023), but this did not remain significant (P = .951) when controlling for the effect of clinical signs or left atrial size/function. CONCLUSIONS AND CLINICAL IMPORTANCE Plasma concentration of cTnI (cutoff >0.7 ng/mL) is a predictor of cardiac death in cats with HCM that is independent of the presence of heart failure or left atrial dilatation.
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Affiliation(s)
- K Borgeat
- Royal Veterinary College, Hatfield, UK; Highcroft Veterinary Referrals, Bristol, UK
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Borgeat K, Wright J, Garrod O, Payne JR, Fuentes VL. Arterial thromboembolism in 250 cats in general practice: 2004-2012. J Vet Intern Med 2013; 28:102-8. [PMID: 24237457 PMCID: PMC4895537 DOI: 10.1111/jvim.12249] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 08/09/2013] [Accepted: 09/26/2013] [Indexed: 11/29/2022] Open
Abstract
Background Population characteristics and outcome of cats with arterial thromboembolism (ATE) managed in general practice (GP) have been poorly described. Hypothesis Cats with ATE presenting to GP are usually euthanized at presentation, but survival times >1 year are possible. Animals Cats with ATE managed by 3 GP clinics in the United Kingdom. Methods Records of cases presenting to GP over a 98‐month period (2004–2012) were reviewed. Cats with an antemortem diagnosis of limb ATE were included. Outcome information was obtained. Results Over 98 months, 250 cats were identified with ATE. Prevalence was approximately 0.3%. At presentation, 153 cats (61.2%) were euthanized, with 68/97 (70.1%) of the remaining cats (27.2% of the total population) surviving >24 hours after presentation. Of these, 30/68 (44.1%) survived for at least 7 days. Hypothermia (HR, 1.44; 95% CI, 1.002–2.07; P = .049) and management by Clinic 2 (HR, 5.53; 95% CI, 1.23–24.8; P = .026) were independent predictors of 24‐hour euthanasia or death. For cats surviving >24 hours, hypothermia (HR, 2.25; 95% CI, 1.12–4.48; P = .021) and failure to receive aspirin, clopidogrel, or both (HR, 8.26; 95% CI, 1.39–50; P = .001) were independent predictors of euthanasia or death within 7 days. For cats that survived ≥7 days, median survival time was 94 (95% CI, 42–164) days, with 6 cats alive 1 year after presentation. Conclusions Although 153/250 cats were euthanized at presentation, 6 cats survived >12 months. No factors were identified that predicted euthanasia on presentation.
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Affiliation(s)
- K Borgeat
- Royal Veterinary College, Hatfield, Hertfordshire, UK
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Lee PT, Japp A, Payne JR. A delayed diagnosis of acute myocarditis: diagnostic value of cardiovascular magnetic resonance imaging. Scott Med J 2012; 57:247. [PMID: 22892447 DOI: 10.1258/smj.2012.012081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Acute myocarditis is an inflammatory disorder of the myocardium associated with cardiac dysfunction. The definition of myocarditis varies, but the Dallas criteria for myocarditis requires an inflammatory infiltrate and associated myocyte necrosis or damage not characteristic of an ischaemic event. Here we present a case of acute myocarditis in a 48-year-old woman masquerading as acute coronary syndrome. Patients with myocarditis usually have normal coronary arteries and we discuss diagnostic difficulties when it presents with 'true' acute coronary syndrome. In this case, cardiovascular magnetic resonance played an important role in the diagnosis of our patient and follow-up.
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Affiliation(s)
- P T Lee
- Cardiology Department, Western Infirmary Glasgow, Dumbarton Road, Glasgow, Scotland, UK.
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Payne JR, Dhamrait SS, Gohlke P, Cooper J, Scott RA, Pitsiladis YP, Humphries SE, Rayner B, Montgomery HE. The impact of ACE genotype on serum ACE activity in a black South African male population. Ann Hum Genet 2007; 71:1-7. [PMID: 17227472 DOI: 10.1111/j.1469-1809.2006.00300.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The strong association between the angiotensin I-converting enzyme (ACE) gene I/D polymorphism with serum ACE activity appears lacking in Nigerians and Kenyans, but has not previously been well assessed in others of African origin. This study addressed this issue in an ethnically well defined black South African population. A putative association for the A22982G ACE gene variant, a QTL likely to impact on serum ACE activity, was also sought. Subjects were 200 healthy male black South African volunteers from the Xhosa ethnic group. Venous blood was obtained from all subjects for DNA extraction. ACE I/D and A22982G genotypes were determined and serum ACE activity measured. Age and blood pressure were recorded. For the group as a whole (mean +/- SD age 38.5 +/- 9.8 years, SBP 119.6 +/- 14.1 mmHg, DBP 78.2 +/- 10.1 mmHg) serum ACE activity was 38.2 +/- 11.2 nmol ml(-1)min(-1). ACE I/D genotype was not significantly associated with serum ACE activity. In contrast, the A22982G variant was significantly associated with serum ACE activity, being 35.9 +/- 9.6, 38.1 +/- 10.6 and 42.4 +/- 15.3 nmol ml(-1)min(-1) for AA, AG and GG genotypes respectively; p = 0.03 by ANOVA and p = 0.01 by linear trend. In keeping with the findings in some other African populations, the ACE I/D polymorphism is not strongly associated with serum ACE activity in Xhosa South Africans. As such, it cannot be used as a marker of ACE activity in these subjects. In this regard the use of the A22982G gene variant may be more appropriate.
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Affiliation(s)
- J R Payne
- Centre for Cardiovascular Genetics, University College London, UK
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Payne JR, Eleftheriou KI, James LE, Hawe E, Mann J, Stronge A, Kotwinski P, World M, Humphries SE, Pennell DJ, Montgomery HE. Left ventricular growth response to exercise and cigarette smoking: data from LARGE Heart. Heart 2006; 92:1784-8. [PMID: 16803937 PMCID: PMC1861277 DOI: 10.1136/hrt.2006.088294] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [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: 01/19/2023] Open
Abstract
BACKGROUND Increasing left ventricular mass is a risk factor for cardiovascular morbidity and mortality. OBJECTIVE To examine the possible association of smoking with the left ventricular growth response in men. METHODS Left ventricular mass was measured in 309 army recruits before and after an identical 12-week physical training programme. Left ventricular mass was determined using cardiovascular magnetic resonance. RESULTS Left ventricular mass increased with training (mean (standard deviation (SD)) 3.83 (10.81) g, p<0.001). By univariate analysis, exercise-induced change in left ventricular mass was positively associated with cigarette smoking (mean (SD) 1.69 (11.10) g v 4.76 (10.23) g for non-smokers v ex- and current smokers, respectively; p = 0.026), whereas age, height, diastolic and systolic blood pressure (SBP), alcohol consumption or indices of physical activity were not significantly associated with change in left ventricular mass. Multivariate analysis showed body weight, smoking status and SBP to be independent predictors of left ventricular mass (incremental R(2) = 3.4%, p = 0.004; R(2) = 4.9%, p = 0.024; and R(2) = 1.7%, p = 0.041, respectively). CONCLUSIONS Cigarette smoking and SBP are associated with exercise-induced left ventricular growth in young men. The positive association of smoking with changes in left ventricular mass is surprising, given the limited exposure of these subjects to smoking, and although these data do not prove causation, they are of great interest to those trying to uncover the drivers of left ventricular hypertrophy, as well as to those examining the possible ill-effects of smoking in the young.
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Affiliation(s)
- J R Payne
- Centre for Cardiovascular Genetics, BHF Laboratories, Royal Free & University College Medical School, London, UK
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Abstract
Anabolic steroid abuse in athletes has been associated with a wide range of adverse conditions, including hypogonadism, testicular atrophy, impaired spermatogenesis, gynaecomastia, and psychiatric disturbance. But what effect does steroid abuse have on the cardiovascular system?
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Payne JR, Dhamrait SS, Toor IS, Cooper J, Jones A, Miller GJ, Humphries SE, Montgomery HE. The −344T>C promoter variant of the gene for aldosterone synthase (CYP11B2) is not associated with cardiovascular risk in a prospective study of UK healthy men. Atherosclerosis 2004; 174:81-6. [PMID: 15135254 DOI: 10.1016/j.atherosclerosis.2004.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2003] [Revised: 12/30/2003] [Accepted: 01/21/2004] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The tissue renin-angiotensin system is implicated in the pathogenesis of coronary artery disease (CAD). As locally synthesised aldosterone is a potential mediator of CAD, we have sought an association of the -344T>C variant of the aldosterone synthase (CYP11B2) gene with CAD events. METHODS Subjects comprised of the Second Northwick Park Heart Study (NPHSII), a prospective study of unrelated, healthy middle-aged Caucasian males. CAD events were recorded in 2490 subjects, and defined as a sudden cardiac death, myocardial infarction or coronary artery revascularisation procedure. Mean follow-up was 10.8 years. Aldosterone synthase genotype was determined in 2490 subjects. Power calculation suggests that we have 80% power (at a significance level of 0.05) to detect a difference in hazard ratio (HR) between homozygote groups of 0.45. RESULTS One hundred and eighty-seven CAD events were recorded in 2490 subjects. In the group overall, CAD events were independent of genotype with adjusted hazard ratios being 1.00 versus 1.25 versus 0.80 for TT versus TC versus CC genotypes, respectively, P = 0.07. Genotype interactions with smoking and blood pressure were sought. Whilst CAD events were independent of genotype amongst non-smokers, CC genotype in smokers was associated with a reduced risk HR 2.02 versus 2.28 versus 0.82 for TT versus TC versus CC genotypes, P = 0.05 (HR for TT + TC versus CC were 1.77 versus 0.67, P = 0.02). This apparent interaction remained after adjustment for conventional risk factors. No such interaction was found with blood pressure. CONCLUSIONS Aldosterone synthase genotype is unrelated to overall CAD events risk. A possible interaction with smoking requires confirmation.
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Affiliation(s)
- J R Payne
- British Heart Foundation Laboratories, Centre for Cardiovascular Genetics, Royal Free & University College Medical School, Rayne Building, 5 University Street, London WC1E 6JF, UK
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Nelson ME, Xu Z, Payne JR. Characterization and modeling of P-type electrosensory afferent responses to amplitude modulations in a wave-type electric fish. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 1997; 181:532-44. [PMID: 9373958 DOI: 10.1007/s003590050137] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [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: 02/05/2023]
Abstract
The first stage of information processing in the electrosensory system involves the encoding of local changes in transdermal potential into trains of action potentials in primary electrosensory afferent nerve fibers. To develop a quantitative model of this encoding process for P-type (probability-coding) afferent fibers in the weakly electric fish Apteronotus leptorhynchus, we recorded single unit activity from electrosensory afferent axons in the posterior branch of the anterior lateral line nerve and analyzed responses to electronically generated sinusoidal amplitude modulations of the local transdermal potential. Over a range of AM frequencies from 0.1 to 200 Hz, the modulation transfer function of P-type afferents is high-pass in character, with a gain that increases monotonically up to AM frequencies of 100 Hz where it begins to roll off, and a phase advance with a range of 15-60 degrees. Based on quantitative analysis of the observed gain and phase characteristics, we present a computationally efficient model of P-type afferent response dynamics which accurately characterizes changes in afferent firing rate in response to amplitude modulations of the fish's own electric organ discharge over a wide range of AM frequencies relevant to active electrolocation.
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Affiliation(s)
- M E Nelson
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign 61801, USA.
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20
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Abstract
1. We recorded single unit activity from individual primary electrosensory afferent axons in the posterior branch of the anterior lateral line nerve of gymnotid weakly electric fish, Apteronotus leptorhynchus. We analyzed the responses of P-type (probability-coding) afferent fibers to externally applied amplitude step changes in the quasi-sinusoidal transdermal potential established by the fish's own electric organ discharge (EOD). 2. In response to AM step increases in transdermal potential, the firing rate of P-type afferents exhibited an abrupt increase followed by an initially rapid and subsequently more gradual decay back toward the baseline level. Afferent responses continued to adapt slowly throughout the duration of prolonged step stimuli lasting > 100 s. The time course of sensory adaptation was similar for all units tested. 3. We introduce a new functional form for describing the time course of sensory adaptation in which the change in firing rate delta r decays logarithmically with time: delta r(t) = A/[B In (t) + 1]. This logarithmic form accurately describes the adaptation time course of P-type afferents over five decades in time, from milliseconds to hundreds of seconds, with only two free parameters. Using a nonlinear least-squares fitting technique, we obtained a mean value of the parameter B, which characterizes the adaptation time course, of 0.149 +/- 0.028 (mean +/- SD, n = 49). 4. We compare logarithmic fits with traditional multiexponential and power law forms and demonstrate that the logarithmic form yields a better characterization of P-type afferent responses. This analysis helps explain the variability in previously reported adaptation time constants, which have ranged from 0.2 to 3.4 s, in gymnotid P-type afferents. 5. We tested the linearity of P-type afferent responses using positive and negative AM steps of varying amplitudes. Aside from nonlinearities associated with rectification (firing rates cannot be negative) and saturation (firing rates cannot exceed the EOD frequency), we found that P-type afferent responses scaled linearly with stimulus amplitude. 6. Based on the observed linearity, we predict the frequency domain response characteristics of P-type afferents and find that the predicted gain and phase are in good agreement with experimental measurements using sinusoidal AM stimuli over a range of AM frequencies from 1 to 100 Hz. Thus the logarithmic parameterization of the step appears to accurately capture the response dynamics of P-type afferents over a wide range of behaviorally relevant AM frequencies. 7. We conclude that the temporal filtering properties of pyramidal cells in the medullary electrosensory nucleus, the electrosensory lateral line lobe (ELL), need to be reevaluated in light of the logarithmic adaptation time course in the periphery, and we discuss implications for the role of P-type afferents in driving a feedback gain control mechanism that regulated ELL pyramidal cell responsiveness.
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Affiliation(s)
- Z Xu
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign 61801, USA
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Wolfe DA, Hameedi MJ, Galt JA, Watabayashi G, Short J, O'Claire C, Rice S, Michel J, Payne JR, Braddock J, Hanna S, Sale D. The fate of the oil spilled from the exxon valdez. Environ Sci Technol 1994; 28:560A-8A. [PMID: 22663575 DOI: 10.1021/es00062a712] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Ounjian M, Roy RR, Eldred E, Garfinkel A, Payne JR, Armstrong A, Toga AW, Edgerton VR. Physiological and developmental implications of motor unit anatomy. J Neurobiol 1991; 22:547-59. [PMID: 1890428 DOI: 10.1002/neu.480220510] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
There is increasing evidence that the architectural design and arrangement of the fibers within a motor unit have important physiological and developmental ramifications. Limited data, however, are available to directly address this issue. In the present study the physiological properties of one motor unit in each of seven cat tibialis anterior (TA) muscles were determined. Each of these units then was repetitively stimulated to deplete the glycogen in all muscle fibers within the unit. Subsequently, the length, type of ending, and spatial distribution of fibers sampled from these physiologically and histochemically typed motor units were determined. Four fast fatigable (FF), one fast, fatigue resistant (FR), and two slow (S) motor units (MU) were studied. The samples consisted of all those glycogen-depleted fibers (9-27) contained within a single fascicle or a circumscribed area of each of the motor unit territories. The mean fiber lengths for the two slow motor units were 35.9 and 45.5 mm. The mean fiber lengths for the fast motor unit samples ranged from 8.8 to 48.5 mm. Some fibers of both the fast and slow units reached lengths of 58 mm. Most of the fibers in the slow units extended the entire distance between the proximal and distal musculotendinous planes, had relatively constant cross-sectional areas, and terminated at the tendon as blunt endings. In contrast, the majority of the fibers in the fast units terminated intrafascicularly at one end, and the cross-sectional area decreased progressively along their lengths, that is, showed a tapering pattern for a significant proportion of their lengths. Therefore, the force generated by units that end midfascicularly would appear to be transmitted to connective tissue elements and/or adjacent fibers. All fibers of a fast unit within a fascicle were located at approximately the same proximo-distal location. Thus, developmentally the selection of muscle fibers by a motoneuron would seem to be influenced by their spatial distribution. The architectural complexities of motor units also have clear implications for the mechanical interactions of active and inactive motor units. For example, the tension capabilities of a motor unit may be influenced not only by the spatial arrangement of its own fibers, but also by the level of activation of neighboring motor units.
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Affiliation(s)
- M Ounjian
- Brain Research Institute, University of California, Los Angeles 90024
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Payne JR. AIDS and food production in East and Central Africa. WHO AIDS Tech Bull 1989; 2:87-8. [PMID: 12342467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Wallace HG, Weaver DB, Kretzmann PM, Payne JR. Bovine parafilariasis: condemnations at the Cato Ridge abattoir. J S Afr Vet Assoc 1983; 54:123-5. [PMID: 6631899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Evidence presented shows a 585% increase in the compounded total carcase condemnations for parafilariasis at the Cato Ridge abattoir in the year July 1981/June 1982 as compared with July 1979/June 1980. There is also evidence which points to condemnations occurring in bi-annual cycles with peaks in November/December and June.
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O'Leary MH, Payne JR. 13C NMR spectroscopy of labeled pyridoxal 5'-phosphate. Model studies, D-serine dehydratase, and L-glutamate decarboxylase. J Biol Chem 1976; 251:2248-54. [PMID: 1262325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pyridoxal 5'-phosphate labeled to the extent of 90% with 13C in the 4' (aldehyde) and 5' (methylene) positions has been synthesized. 13C NMR spectra of this material and of natural abundance pyridoxal 5'-phosphate are reported, as well as 13C NMR spectra of the Schiff base formed by reaction of pyridoxal 5'-phosphate with n-butylamine, the secondary amine formed by reduction of this Schiff base, the thiazolidine formed by reaction of pyridoxal 5'-phosphate with cysteine, the hexahydropyrimidine formed by reaction of pyridoxal 5'-phosphate with 1,3-diaminobutane, and pyridoxamine 5'-phosphate. The range of chemical shifts for carbon 4' in these compounds is more than 100 ppm, and thus this chemical shift is expected to be a sensitive indicator of structure in enzyme-bound pyridoxal 5'-phosphate. The chemical shift of carbon 5', on the other hand, is insensitive to these structure changes. 13C NMR spectra have been obtained at pH 7.8 and 9.4 for D-serine dehydratase (Mr = 46,000) containing natural abundance pyridoxal 5'-phosphate and containing 13C-enriched pyridoxal 5'-phosphate. The enriched material contains two new resonances not present in the natural abundance material, one at 167.7 ppm with a linewidth of approximately 24 Hz, attributed to carbon 4' of the Schiff base in the bound coenzyme, and one at 62.7 Hz with a linewidth of approximately 48 Hz attributed to carbon 5' of the bound Schiff base. A large number of resonances due to individual amino acids are assigned. The NMR spectrum changes only slightly when the pH is raised to 9.4. The widths of the two enriched coenzyme resonances indicate that the coenzyme is rather rigidly bound to the enzyme but probably has limited motional freedom relative to the protein. 13C NMR spectra have been obtained for L-glutamate decarboxylase containing natural abundance pyridoxal 5'-phosphate and 13C-enriched pyridoxal 5'-phosphate. Under conditions where the two enriched 13C resonances are clearly visible in D-serine dehydratase, no resonances are visible in enriched L-glutamate decarboxylase, presumably because the coenzyme is rigidly bound to the protein and the 300,000 molecular weight of this enzyme produces very short relaxation times for the bound coenzyme and thus very broad lines.
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Waldroup PW, Mitchell RJ, Payne JR, Hazen KR. Performance of chicks fed diets formulated to minimize excess levels of essential amino acids. Poult Sci 1976; 55:243-53. [PMID: 934987 DOI: 10.3382/ps.0550243] [Citation(s) in RCA: 100] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Studies were conducted in which levels of essential amino acids in excess of the minimum requirements were minimized in broiler diets composed of commercially available feed stuffs and synthetic amino acid supplements. Growth rate and efficiency of feed utilization of chicks fed such diets were equal to that attained by chicks fed diets formulated by conventional means when grown under conditions where heat stress was not a factor and significantly improved when fed under conditions of heat stress. Improvements were obtained in efficiency of protein and calorie utilization using this technique of formulation.
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Payne JR. Clinically severe lactic acidosis with coma. Calif Med 1966; 105:281-4. [PMID: 4962640 PMCID: PMC1516503] [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: 01/13/2023]
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