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Potier JFN, Durham AE, Modi R, Rosenberg W, Dash SA. Investigation of Serum Markers of Hepatic Fibrosis in Equids. J Equine Vet Sci 2023; 131:104937. [PMID: 37816414 DOI: 10.1016/j.jevs.2023.104937] [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: 02/09/2023] [Revised: 10/04/2023] [Accepted: 10/04/2023] [Indexed: 10/12/2023]
Abstract
Liver disease is common in equine practice, and treatment and prognosis are dependent on histopathologic examination of biopsies. Liver biopsy is invasive and expensive which restricts its use. Serum markers are used to predict hepatic fibrosis in humans. This study aimed to investigate the enhanced liver fibrosis (ELF) test, based on serum Hyaluronic Acid (HA), procollagen III N-terminal peptide (PIIINP), and tissue inhibitor of metalloproteinase 1 (TIMP-1) to detect hepatic fibrosis in equids. Four groups were included; two with increased serum concentrations of liver-derived enzymes and a liver biopsy (group H; 10 horses and ponies and group D; 10 donkeys) and two without any evidence of liver disease (group HC; 10 horses and ponies and group DC; 10 donkeys). All samples were analyzed for concentrations of HA, PIINP, and TIMP-1. Given the failure to detect TIMP-1 in most subjects, a novel eELF (equid ELF) score was calculated, based on HA and PIIINP. HA and PIIINP concentrations and the eELF score, were compared with determined hepatic fibrosis. HA, PIIINP, and eELF were significantly greater in horses and ponies with a histopathologic fibrosis score ≥ 2 compared with those < 2. A similar observation was found with donkeys for HA and eELF. A significant correlation was found between fibrosis score and HA, PIIINP, and eELF for horses and ponies, and between fibrosis score and HA and eELF in donkeys. Serum HA and the eELF score might be useful serum markers to predict and monitor hepatic fibrosis in horses, ponies, and donkeys.
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Affiliation(s)
| | | | - Raakesh Modi
- iQur Ltd.Division of Medicine, Royal Free Hospital, University College London, London, UK
| | - William Rosenberg
- Division of Medicine, Institute for Liver and Digestive Health, University College London, London, UK
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Li FI, Spence RJ, de Laat MA, Harris PA, Sonntag J, Menzies-Gow NJ, Durham AE, Bailey SR, Sillence MN. Association between insulin dysregulation and adrenocorticotropic hormone in aged horses and ponies with no clinical signs of pituitary pars intermedia dysfunction. Equine Vet J 2023; 55:1003-1011. [PMID: 36641787 DOI: 10.1111/evj.13925] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 01/05/2023] [Indexed: 01/16/2023]
Abstract
BACKGROUND High concentrations of adrenocorticotropic hormone (ACTH) are used as an indicator of pituitary pars intermedia dysfunction (PPID), but other factors that may influence ACTH need to be understood, if diagnostic reference ranges for ACTH are to be used with confidence. Insulin dysregulation (ID) could be one such factor, as insulin affects pituitary hormones in other species. OBJECTIVES To test the hypothesis that a relationship exists between high insulin and high ACTH in aged (>15-year-old) animals with no clinical signs of PPID. STUDY DESIGN A cohort study. METHODS Thirteen horses and eleven ponies (17-25 years-old; mares and geldings) were clinically examined for signs of PPID in the spring (November 2020) and autumn (April 2021). On the same day, blood samples were taken before and 2 h after an oral glucose test (OGT). Concentrations of insulin, glucose, ACTH and cortisol were measured. RESULTS There was no association between ACTH and cortisol. However, there was a positive linear correlation between ACTH and post-OGT (insulin in the autumn (r = 0.427, p = 0.04). Two horses and six ponies had ACTH above the cut-off value for PPID diagnosis, and of these eight animals, six also had insulin concentrations above the cut-off value for ID. MAIN LIMITATIONS The cohort was small and thyrotropin-releasing hormone (TRH) stimulation tests were not performed. CONCLUSIONS In autumn, high ACTH was associated with ID, when no clinical signs of PPID were present. Because ACTH is used in PPID diagnosis, further work is required to understand this interaction.
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Affiliation(s)
- Fang I Li
- School of Biology & Environmental Science, Science Faculty, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Robert J Spence
- School of Biology & Environmental Science, Science Faculty, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Melody A de Laat
- School of Biology & Environmental Science, Science Faculty, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
| | - Patricia A Harris
- Equine Studies Group, Waltham Petcare Science Institute, Leicestershire, UK
| | - Johanna Sonntag
- Boehringer Ingelheim Vetmedica GmbH, Ingelheim am Rhein, Germany
| | | | | | - Simon R Bailey
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Martin N Sillence
- School of Biology & Environmental Science, Science Faculty, Queensland University of Technology (QUT), Brisbane, Queensland, Australia
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Stewart AJ, Ireland JL, Durham AE, McGowan CM. Diagnosis of equine pituitary pars intermedia dysfunction. Vet J 2023; 300-302:106036. [PMID: 37805159 DOI: 10.1016/j.tvjl.2023.106036] [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: 12/23/2022] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Equine pituitary pars intermedia dysfunction (PPID) is common in aged horses. The majority of horses respond well to treatment, but treatment is lifelong, meaning accurate diagnosis of PPID is important. Similar to any condition, there is no perfect laboratory test to diagnose PPID and accuracy is affected by the characteristics of the population in which the test is being evaluated. This review details the importance of consideration of clinical factors and diagnostic test accuracy. Basal adrenocorticotrophic hormone (ACTH) concentration is used most frequently in practice and has very good diagnostic accuracy when used in combination with clinical judgement and the correct application of diagnostic thresholds. The thyrotropin-releasing hormone stimulation test can be used in horses with equivocal test results following basal ACTH testing, or to evaluate subtle cases due to its improved accuracy.
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Affiliation(s)
| | - Joanne L Ireland
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK
| | - Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK
| | - Catherine M McGowan
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK.
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Delarocque J, Feige K, Carslake HB, Durham AE, Fey K, Warnken T. Development of a Web App to Convert Blood Insulin Concentrations among Various Immunoassays Used in Horses. Animals (Basel) 2023; 13:2704. [PMID: 37684968 PMCID: PMC10487020 DOI: 10.3390/ani13172704] [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: 07/03/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
The measurement of the blood insulin concentration, and comparison to cut-offs, is essential in diagnosing insulin dysregulation, a common equine endocrinopathy. However, different insulin assays provide disparate results. We aimed to ease comparison between assays by compiling original and published data into a web app to convert insulin measurements from one assay to another. Data were available for ADVIA Centaur insulin chemiluminescent immunoassay (CLIA), Beckman Coulter insulin radioimmunoassay (RIA), Immulite 1000 CLIA, Immulite 2000 CLIA, Immulite 2000 XPi CLIA, Mercodia equine insulin enzyme-linked immunosorbent assay (ELISA), and Millipore porcine insulin RIA. Linear models were fitted for 13 assay pairs using non-decreasing splines, and integrated into this app. Assay comparisons including data from several studies showed a lower performance. This indicates technical variation between laboratories, which has not been described before, but is relevant when diagnostic measurements and cut-offs are provided by different laboratories. Nevertheless, the models' overall high performance (median r2 = 0.94; range 0.57-1.00) supports their use to interpret results from diagnostic insulin measurements when the reference assay is unavailable, and to compare values obtained from different assays.
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Affiliation(s)
- Julien Delarocque
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, 30559 Hannover, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, 30559 Hannover, Germany
| | - Harry B. Carslake
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst, Neston CH64 7TE, Cheshire, UK
| | - Andy E. Durham
- The Liphook Equine Hospital, Forest Mere, Liphook GU30 7JG, Hampshire, UK
| | - Kerstin Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Frankfurter Str. 126, 35392 Giessen, Germany
| | - Tobias Warnken
- Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Bünteweg 9, 30559 Hannover, Germany
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de Laat MA, Warnken T, Delarocque J, Reiche DB, Grob AJ, Feige K, Carslake HB, Durham AE, Sillence MN, Thane KE, Frank N, Brojer J, Lindase S, Sonntag J. Carbohydrate pellets to assess insulin dysregulation in horses. Vet Med (Auckl) 2022; 37:302-314. [PMID: 36583553 PMCID: PMC9889680 DOI: 10.1111/jvim.16621] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 12/14/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND A glycemic challenge test is used for the diagnosis of insulin dysregulation (ID) in horses and ponies. Different forms of the test exist where the administrative route and dose of glucose vary, which makes interpretation of results challenging. HYPOTHESIS/OBJECTIVES To evaluate the palatability of, and blood glucose and insulin responses to, carbohydrate pellets fed as an oral glucose test (OGT), and to establish the diagnostic threshold for ID when using the pellets. ANIMALS University and privately-owned horses and ponies (n = 157) comprised of 31 breeds and both sexes. METHODS Multicenter cohort study. A custom-produced glycemic pellet was offered for free intake at 0.5 g/kg BW soluble carbohydrate and serum insulin and blood glucose concentrations measured before and after (60, 120, and 180 minutes) the pellets were offered. Pellet acceptance and intake time (those that finished within 10 minutes) were determined to assess palatability. RESULTS The pellets were palatable to 132/157 animals, and ponies found the pellets more (P = .004) palatable than horses. The median intake time (4 [3-6] minutes) was positively correlated with acceptance grade (r = .51; P < .0001). Consumption of the pellets elicited peak blood glucose (6.6 [5.8-7.8] mmol/L) and serum insulin (40.5 [19-99.8] μIU/mL) responses at 120 minutes. At 120 minutes the optimal cut-off was 83 μIU/mL (95% CI: 70-99 μIU/mL) for the IMMULITE 2000XPi assay. CONCLUSIONS AND CLINICAL IMPORTANCE The pellets were palatable and a suitable, novel carbohydrate source for the OGT.
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Affiliation(s)
- Melody A. de Laat
- Faculty of ScienceQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Tobias Warnken
- Boehringer Ingelheim Vetmedica GmbHIngelheimGermany,Clinic for HorsesUniversity of Veterinary MedicineHannoverGermany
| | | | | | - Anne J. Grob
- Clinic for HorsesUniversity of Veterinary MedicineHannoverGermany
| | - Karsten Feige
- Clinic for HorsesUniversity of Veterinary MedicineHannoverGermany
| | - Harry B. Carslake
- Institute of Infection, Veterinary and Ecological SciencesUniversity of LiverpoolLiverpoolUK
| | | | - Martin N. Sillence
- Faculty of ScienceQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Kristen E. Thane
- Department of Comparative PathobiologyCummings School of Veterinary Medicine, Tufts UniversityNorth GraftonMassachusettsUSA
| | - Nicholas Frank
- Department of Comparative PathobiologyCummings School of Veterinary Medicine, Tufts UniversityNorth GraftonMassachusettsUSA
| | - Johan Brojer
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | - Sanna Lindase
- Department of Clinical SciencesSwedish University of Agricultural SciencesUppsalaSweden
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Durham AE. Association between forage mycotoxins and liver disease in horses. J Vet Intern Med 2022; 36:1502-1507. [PMID: 35792718 PMCID: PMC9308415 DOI: 10.1111/jvim.16486] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 06/15/2022] [Indexed: 11/30/2022] Open
Abstract
Background Outbreaks of liver disease in horses are common but the etiology of most remains unknown. Forage mycotoxins have been suspected to be a cause. Objectives To examine the association between outbreaks of liver disease and the presence of mycotoxins in forage stored on the same premises. Animals Premises were identified where ≥4 horses were contemporaneously affected by liver disease, and a control group was formed from premises where ≥4 horses had been examined and found to have no evidence of liver disease. Methods Forage was collected from 29 case and 12 control premises. The forage was analyzed for mycotoxin content using a liquid chromatography/mass spectrometry method, targeting 54 mycotoxins. The presence and distribution of mycotoxins between case and control samples was compared. Results Mycotoxins were found in 23/29 (79%) case samples and 10/12 (83%) control samples (P > .99; relative risk, 0.93; 95% confidence interval [CI], 0.64‐1.75). Median (interquartile range [IQR]) total mycotoxin concentration was similar in case and control samples (85.8 μg/kg [1.6‐268] vs. 315 μg/kg [6.3‐860]; P = .16). Ten mycotoxins were found exclusively in case premises comprising fumonisin B1, 15‐acetyldeoxynivalenol, deoxynivalenol, zearalenone, aflatoxins B1 and G1, methylergonovine, nivalenol, verruculogen, and wortmannin. The median (IQR) concentration of fumonisin B1 was significantly higher in case versus control samples (0 μg/kg [0‐81.7] vs. 0 μg/kg [0‐0]; P = .04). Conclusions and Clinical Importance Several mycotoxins with known hepatotoxic potential were found, alone or in combination, exclusively at case premises, consistent with the hypothesis that forage‐associated mycotoxicosis may be a cause of outbreaks of liver disease in horses in the United Kingdom.
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Durham AE. The effect of pergolide mesylate on adrenocorticotrophic hormone responses to exogenous thyrotropin releasing hormone in horses. Vet J 2022; 285:105831. [PMID: 35477010 DOI: 10.1016/j.tvjl.2022.105831] [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: 01/19/2022] [Revised: 03/08/2022] [Accepted: 04/21/2022] [Indexed: 10/18/2022]
Abstract
Thyrotropin releasing hormone (TRH) stimulation testing is often used to support a diagnosis of pituitary pars intermedia dysfunction (PPID) in horses although it is unclear whether or not repeat TRH stimulation testing post-treatment is a valid means of assessing response to medical therapy. Laboratory submissions from 64 suspected equine PPID cases were examined including the initial pre-treatment TRH stimulation test and a follow up test within 100 days of starting medical therapy with pergolide. In a subset of cases, further follow-up tests were examined beyond 100 days of starting treatment. Results from tests conducted between 1 July and 30 November 30 were excluded. Significant improvements were seen in both the baseline and TRH-stimulated adrenocorticotrophic hormone (ACTH) concentrations within 100 days with no further improvements seen in the subset of cases examined thereafter. Although 88% (n=56/64) of all cases showed a decreased response to TRH post-treatment, only 24% (n=9/38) of horses with positive pre-treatment TRH stimulation tests normalised following treatment, with a further 34% (n=13/38) improving into an equivocal test outcome category. Most commonly (42%; n=16/38), horses with positive pre-treatment TRH stimulation tests remained positive following treatment, although 75% (n=12/16) of these showed a numerically lower post-treatment response to TRH. These results will help inform practitioners of expected changes in TRH stimulation test results when assessing response of horses with PPID to medical therapy with pergolide.
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Affiliation(s)
- A E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK.
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Tura G, Savini F, Gallina L, La Ragione RM, Durham AE, Mazzeschi M, Lauriola M, Avallone G, Sarli G, Brunetti B, Muscatello LV, Girone C, Bacci B. Fibroblast-associated protein-α expression and BPV nucleic acid distribution in equine sarcoids. Vet Pathol 2021; 58:1044-1050. [PMID: 34128437 DOI: 10.1177/03009858211022696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Sarcoids are the most common cutaneous tumor of equids and are caused by bovine papillomavirus (BPV). Different clinical subtypes of sarcoids are well characterized clinically but not histologically, and it is not known whether viral activity influences the clinical or histological appearance of the tumors. The aim of this study was to verify whether the development of different clinical types of sarcoids or the presence of certain histological features were associated with BPV distribution within the tumor. The presence of BPV was assessed by polymerase chain reaction (PCR) and visualized in histological sections by chromogenic in situ hybridization (CISH) in 74 equine sarcoids. Furthermore, to better characterize the molecular features of neoplastic cells, immunohistochemistry for S100, smooth muscle actin-α (αSMA), and fibroblast-associated protein-α (FAPα) was performed. The presence of BPV was confirmed in all tissues examined by either or both PCR and CISH (72/74, 97% each). Of 70/74 CISH-positive cases, signal distribution appeared as either diffuse (61/70, 87%) or subepithelial (9/70, 13%); the latter was more frequently observed in the verrucous subtype. However, no statistically significant association was found between clinical subtypes and specific histological features or hybridization pattern. Moreover, CISH signal for BPV was not detected in the epidermis overlying sarcoids nor in the tissue surrounding the neoplasms. By immunohistochemistry, αSMA confirmed the myofibroblastic differentiation of neoplastic cells in 28/74 (38%) sarcoids. Using tissue microarrays, FAPα labelling was observed in neoplastic fibroblasts of all sarcoids, suggesting this marker as a potential candidate for the immunohistochemical diagnosis of sarcoids.
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Affiliation(s)
- Giorgia Tura
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Federica Savini
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Laura Gallina
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | | | - Andy E Durham
- School of Veterinary Medicine and Science, 417508University of Surrey, UK.,Liphook Equine Hospital, Liphook, UK
| | - Martina Mazzeschi
- Department of Experimental, Diagnostic and Specialty Medicine, 9296University of Bologna, Italy
| | - Mattia Lauriola
- Department of Experimental, Diagnostic and Specialty Medicine, 9296University of Bologna, Italy
| | - Giancarlo Avallone
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Giuseppe Sarli
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Barbara Brunetti
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Luisa V Muscatello
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Cinzia Girone
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
| | - Barbara Bacci
- Department of Veterinary Medical Sciences, 9296University of Bologna, Italy
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Durham AE, Clarke BR, Potier JFN, Hammarstrand R, Malone GL. Clinically and temporally specific diagnostic thresholds for plasma ACTH in the horse. Equine Vet J 2020; 53:250-260. [PMID: 32470177 DOI: 10.1111/evj.13292] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 08/28/2019] [Accepted: 05/10/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Pituitary pars intermedia dysfunction (PPID) is commonly investigated using plasma ACTH concentrations but problems exist with currently available diagnostic thresholds. OBJECTIVES To derive temporally specific diagnostic thresholds for equine plasma ACTH concentration to be used alongside clinical judgement in each individual week of the year and appropriate for the degree of clinical suspicion in any given case. Furthermore, to apply these thresholds to compare the prevalence of high and low ACTH in two subgroups of animals with high and low clinical suspicion of PPID. STUDY DESIGN A retrospective population study examining a large laboratory database of equine plasma ACTH concentrations using an indirect approach to calculate diagnostic thresholds. METHODS Logs of plasma ACTH concentrations from 75 892 individual horses were examined using robust L2 estimation of mixtures of two normal distributions in categories of each week and month of the year. Thresholds dividing the two populations of high-ACTH and low-ACTH horses were then established at different levels of sensitivity and specificity and compared with clinical subgroups of horses divided based on reported clinical signs, as having high (n = 4036) or low (n = 3022) clinical suspicion of PPID. RESULTS For most of the year there were small interweek differences in diagnostic thresholds. However, from mid-June to early-December diagnostic thresholds showed greater interweek variability, reaching a maximum in late September and early October. Grouping of high- and low-ACTH compared favourably with grouping based on clinical signs. MAIN LIMITATIONS Given the multiple sources of diagnostic samples, pre-analytical data could not be fully verified. CONCLUSIONS Diagnostic thresholds for equine plasma ACTH vary through the year. It is especially important to consider the temporally specific threshold between June and December. Different clinical thresholds can be used depending on the case circumstances and whether a false-positive or false-negative diagnosis is deemed least desirable.
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Affiliation(s)
| | - Brenton R Clarke
- Mathematics and Statistics, ITMAS, College of Science, Health, Engineering and Education, Murdoch University, Western Australia, Australia
| | | | - Robert Hammarstrand
- Mathematics and Statistics, ITMAS, College of Science, Health, Engineering and Education, Murdoch University, Western Australia, Australia
| | - George L Malone
- Mathematics and Statistics, ITMAS, College of Science, Health, Engineering and Education, Murdoch University, Western Australia, Australia
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Durham AE, Kemp-Symonds J. Failure of serological testing for antigens A and C of Streptococcus equi subspecies equi to identify guttural pouch carriers. Equine Vet J 2020; 53:38-43. [PMID: 32374892 DOI: 10.1111/evj.13276] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [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: 12/11/2019] [Revised: 04/05/2020] [Accepted: 04/23/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. OBJECTIVES The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. STUDY DESIGN Retrospective clinical study. METHODS As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibodies directed at S. equi antigens A and C. Laboratory results and endoscopic findings were examined to determine associations between serological results and guttural pouch carriage of S. equi. RESULTS Of 287 included horses, 9 (3.1%) were found to be guttural pouch carriers. There was no significant association between serological status and guttural pouch carriage of S. equi Only one of the nine carriers (11%) was seropositive using a cut-off of OD ≥ 0.5, and only three of nine (33%) using a cut-off of OD ≥ 0.3. MAIN LIMITATIONS Horses examined in this study were new arrivals at a welfare centre rather than from a general, well-managed, equid population. As a retrospective clinical study, the laboratory test results could not be repeated for further confirmation. CONCLUSIONS Caution is advised when relying on seronegativity to antigens A and C in order to discount the possibility of chronic carriage of S. equi in guttural pouches.
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Potier JFN, Durham AE. Antimicrobial susceptibility of bacterial isolates from ambulatory practice and from a referral hospital. J Vet Intern Med 2020; 34:300-306. [PMID: 31849110 PMCID: PMC6979268 DOI: 10.1111/jvim.15685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/04/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Responsible use of antimicrobials in equine practice relies on knowledge of common bacterial isolates and their antimicrobial sensitivities. OBJECTIVES To assess the frequency of bacterial resistance to a combination of parenteral penicillin and gentamicin and to trimethoprim and sulfamethoxazole for PO use in a selection of clinical isolates, and subsequently to determine the prevalence of resistance to antimicrobials that might then be used as alternatives to first-line antimicrobials for the same isolates. METHODS Retrospective analysis of minimal inhibitory concentrations (MICs) of antimicrobials for 6354 bacterial isolates from 365 ambulatory practices and 519 isolates from a referral hospital. The MICs were used to indicate sensitivity or resistance to commonly used antimicrobials and the prevalences of resistance were compared between origin of the isolates, and among antimicrobial drugs. RESULTS Isolates from the referral hospital were significantly (P < .05) more likely to be resistant to the antimicrobials tested than those derived from ambulatory practice. Overall, 91% of the ambulatory isolates and 64% of the hospital isolates were sensitive to penicillin-gentamicin. For trimethoprim-sulfamethoxazole combination, 82% of the ambulatory practice isolates and 56% of the referral hospital isolates were sensitive. CONCLUSIONS AND CLINICAL IMPORTANCE Most isolates were sensitive to penicillin and gentamicin as well as trimethoprim-sulfamethoxazole. No predictable efficacious second choice antimicrobial was identified for those isolates resistant to the first-line antimicrobials. The likelihood of isolates being sensitive to second choice antimicrobials was variable but generally higher for ambulatory isolates compared to referral isolates. Bacterial identification and measurement of MIC are essential to make the appropriate antimicrobial choice.
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Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. Response to letter to editor regarding ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019; 33:1125-1126. [PMID: 30990917 PMCID: PMC6524088 DOI: 10.1111/jvim.15503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 11/30/2022] Open
Affiliation(s)
| | - Nicholas Frank
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts
| | - Cathy M McGowan
- Institute of Veterinary Science, University of Liverpool, United Kingdom
| | - Nicola J Menzies-Gow
- Department of clinical sciences and services, Royal Veterinary College, Herts, United Kingdom
| | - Ellen Roelfsema
- Utrecht University, Department of Equine Sciences, Utrecht, The Netherlands
| | - Ingrid Vervuert
- Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Kersten Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany
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Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019; 33:335-349. [PMID: 30724412 PMCID: PMC6430910 DOI: 10.1111/jvim.15423] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/11/2019] [Indexed: 12/26/2022] Open
Abstract
Equine metabolic syndrome (EMS) is a widely recognized collection of risk factors for endocrinopathic laminitis. The most important of these risk factors is insulin dysregulation (ID). Clinicians and horse owners must recognize the presence of these risk factors so that they can be targeted and controlled to reduce the risk of laminitis attacks. Diagnosis of EMS is based partly on the horse's history and clinical examination findings, and partly on laboratory testing. Several choices of test exist which examine different facets of ID and other related metabolic disturbances. EMS is controlled mainly by dietary strategies and exercise programs that aim to improve insulin regulation and decrease obesity where present. In some cases, pharmacologic aids might be useful. Management of an EMS case is a long‐term strategy requiring diligence and discipline by the horse's carer and support and guidance from their veterinarians.
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Affiliation(s)
| | - Nicholas Frank
- Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts
| | - Cathy M McGowan
- Institute of Veterinary Science, University of Liverpool, Neston, United Kingdom
| | - Nicola J Menzies-Gow
- Department of clinical sciences and services, Royal Veterinary College, Herts, United Kingdom
| | - Ellen Roelfsema
- Department of Equine Sciences, Utrecht University, Utrecht, The Netherlands
| | - Ingrid Vervuert
- Faculty of Veterinary Medicine, University of Leipzig, Institute of Animal Nutrition, Nutrition Diseases and Dietetics, Leipzig, Germany
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Germany
| | - Kerstin Fey
- Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany
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Durham AE, Hall YS, Kulp L, Underwood C. A study of the environmental survival of Streptococcus equi subspecies equi. Equine Vet J 2018; 50:861-864. [PMID: 29654609 DOI: 10.1111/evj.12840] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 10/07/2017] [Accepted: 03/30/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Streptococcus equi represents a common hazard to equids worldwide. Environmental contamination with bacteria shed from an infected horse may represent a significant source of contagion and further knowledge of ex vivo bacterial survival under different conditions is important for disinfection and isolation protocols. OBJECTIVES To determine the potential duration of survival and vigour of growth of S. equi inoculated onto surfaces relevant to equine veterinary practice and stabling in summer and winter. STUDY DESIGN Repeat sampling of environmental inocula of S. equi. METHODS Cultures of S. equi were inoculated onto wood, a shoe sole, cotton overalls, inside a nasogastric tube, inside a dental rasp, in a wet plastic bucket and onto a fence post both in the summer and winter seasons. Frequent resampling and culture from the inoculated sites was conducted until no viable bacteria were found. Bacterial viability was determined by both duration (time to first negative culture) and vigour of growth (growth score over the first 3 days of culture) and compared between inoculated sites and times of year. RESULTS Bacterial viability was enhanced by a wet local environment and by the winter season. Survival tended to be short in the summer (up to 9 days in wet sites and up to 2 days in dry sites) but much longer in the winter (up to 34 days in wet sites and up to 13 days in dry sites). Vigour of bacterial growth was also greater in the winter than in the summer as judged by 3-day-growth scores. MAIN LIMITATIONS Direct comparison with the variable size and nature of naturally shed infectious material is difficult. CONCLUSIONS Veterinarians and personnel handling horses should be aware that S. equi may survive in an equine environment for longer than previously found, especially when protected by wet and cold conditions.
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Affiliation(s)
- A E Durham
- Liphook Equine Hospital, Liphook, Hampshire, UK
| | - Y S Hall
- Liphook Equine Hospital, Liphook, Hampshire, UK
| | - L Kulp
- The Village Animal Hospital, Caterham, Surrey, UK
| | - C Underwood
- University of Pennsylvania, School of Veterinary Medicine, Philadelphia, Pennsylvania, USA
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Durham AE. An evaluation of serum gentamicin concentrations and bacterial susceptibility to gentamicin in equine practice. J Vet Intern Med 2018; 32:1194-1201. [PMID: 29575239 PMCID: PMC5980452 DOI: 10.1111/jvim.15078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [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: 10/09/2017] [Revised: 09/27/2017] [Accepted: 01/23/2018] [Indexed: 12/01/2022] Open
Abstract
Background Therapeutic drug monitoring and minimum inhibitory concentration (MIC) data allow more informed use of gentamicin. Hypothesis/Objectives To measure peak and trough serum gentamicin concentrations in horses after a 6.6 mg/kg dose of gentamicin given IV and the MIC of gentamicin of bacteria for which gentamicin might be selected. Methods Retrospective analysis of hospital records. Peak and trough plasma gentamicin concentrations were measured after 6.6 mg/kg gentamicin IV in 339 hospitalized horses. The MIC of gentamicin was measured for 503 isolates from ambulatory practice and 33 from hospital practice. The distribution of gentamicin concentrations and MIC results were compared to current recommendations for MIC breakpoints. Results The median serum gentamicin concentration at 60 minutes after administration (C60min) was 21.4 μg/mL with a distribution indicating that bacteria with MIC ≥2 μg/mL were unlikely to be exposed to sufficient gentamicin for effective killing. Approximately 90% of isolates from ambulatory practice and 36% of hospital isolates had MICs at or below breakpoints for susceptibility with most of the remainder unlikely to be responsive, even to higher IV doses. Conclusions and Clinical Importance Gentamicin at a dosage of 6.6 mg/kg IV is likely to be effective against the majority of infections encountered in ambulatory practice, but less effective in an equine hospital. Because there was a dichotomy of most bacteria as being clearly susceptible or clearly resistant to gentamicin, it appears unlikely that higher doses would have been more efficacious, especially in the hospitalized population in our study.
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Affiliation(s)
- Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire, United Kingdom
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Abstract
Equine endocrine disease is commonly encountered by equine practitioners. Pituitary pars intermedia dysfunction (PPID) and equine metabolic syndrome (EMS) predominate. The most logical therapeutic approach in PPID uses dopamine agonists; pergolide mesylate is the most common. Bromocryptine and cabergoline are alternative drugs with similar actions. Drugs from other classes have a poor evidence basis, although cyproheptadine and trilostane might be considered. EMS requires management changes as the primary approach; reasonable justification for use of drugs such as levothyroxine and metformin may apply. Therapeutic options exist in rare cases of diabetes mellitus, diabetes insipidus, hyperthyroidism, and critical illness-related corticosteroid insufficiency.
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Affiliation(s)
- Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK.
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Affiliation(s)
- Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK.
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Affiliation(s)
- Andy E Durham
- Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG
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Rendle DI, Duz M, Beech J, Parkin T, Durham AE. Investigation of single and paired measurements of adrenocorticotropic hormone for the diagnosis of pituitary pars intermedia dysfunction in horses. J Vet Intern Med 2014; 29:355-61. [PMID: 25312676 PMCID: PMC4858100 DOI: 10.1111/jvim.12489] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [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: 06/14/2014] [Revised: 08/11/2014] [Accepted: 09/16/2014] [Indexed: 11/28/2022] Open
Abstract
Background Paired measurement of ACTH concentration may be more reliable than a single measurement. Hypothesis/Objectives To determine whether the mean of 2 measurements of ACTH concentration is more reliable in assessing pituitary pars intermedia dysfunction (PPID) than a single measurement. Animals Paired ACTH measurements were performed on (1) 148 occasions from 124 horses being investigated for PPID, (2) 90 occasions from 76 horses with PPID that were receiving treatment with pergolide, and (3) 63 occasions from 50 horses in which there was no clinical suspicion of PPID. Histologic examination of the pars intermedia was performed in 67 of the untreated horses. Methods Outcome of testing using single and the mean of paired samples was compared directly and both methods were compared against histology, which was considered the gold standard. Results Paired ACTH measurement altered binary classification as healthy or diseased in 6 of 211 cases, all off which had equivocal initial ACTH concentrations between 20 and 39 pg/mL. Using histology as the gold standard, optimal sensitivity and specificity for diagnosing PPID were 69.4 and 80.9%, respectively, for a single measurement and 72.2 and 76.2%, respectively, for paired measurements. The area under the receiver operating characteristic curve was 0.72 and 0.73 for single and paired measurements compared with histopathologic diagnosis, respectively. Conclusions and Clinical Importance Paired measurement of ACTH concentration offers no advantage over a single measurement.
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Affiliation(s)
- D I Rendle
- The Liphook Equine Hospital, Liphook, Hampshire, UK
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Durham AE, Geor RJ, Ireland JL, McGowan CM, Schott HC. Science-in-brief: Report from the second [corrected] European Equine Endocrinology symposium. Equine Vet J 2014; 46:525-8. [PMID: 25099187 DOI: 10.1111/evj.12313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Lyons S, Kapoor A, Schneider BS, Wolfe ND, Culshaw G, Corcoran B, Durham AE, Burden F, McGorum BC, Simmonds P. Viraemic frequencies and seroprevalence of non-primate hepacivirus and equine pegiviruses in horses and other mammalian species. J Gen Virol 2014; 95:1701-1711. [PMID: 24814924 DOI: 10.1099/vir.0.065094-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Non-primate hepacivirus (NPHV), equine pegivirus (EPgV) and Theiler's disease associated virus (TDAV) are newly discovered members of two genera in the Flaviviridae family, Hepacivirus and Pegivirus respectively, that include human hepatitis C virus (HCV) and human pegivirus (HPgV). To investigate their epidemiology, persistence and clinical features of infection, large cohorts of horses and other mammalian species were screened for NPHV, EPgV and TDAV viraemia and for past exposure through serological assays for NPHV and EPgV-specific antibodies. NPHV antibodies were detected in 43% of 328 horses screened for antibodies to NS3 and core antibodies, of which three were viraemic by PCR. All five horses that were stablemates of a viraemic horse were seropositive, as was a dog on the same farm. With this single exception, all other species were negative for NPHV antibodies and viraemia: donkeys (n=100), dogs (n=112), cats (n=131), non-human primates (n=164) and humans (n=362). EPgV antibodies to NS3 were detected in 66.5% of horses, including 10 of the 12 horses that had EPgV viraemia. All donkey samples were negative for EPgV antibody and RNA. All horse and donkey samples were negative for TDAV RNA. By comparing viraemia frequencies in horses with and without liver disease, no evidence was obtained that supported an association between active NPHV and EPgV infections with hepatopathy. The study demonstrates that NPHV and EPgV infections are widespread and enzootic in the study horse population and confirms that NPHV and potentially EPgV have higher frequencies of viral clearance than HCV and HPgV infections in humans.
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Affiliation(s)
- Sinéad Lyons
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK
| | - Amit Kapoor
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | | | - Nathan D Wolfe
- Metabiota, 1 Sutter Street, Suite 600, San Francisco, CA 94104, USA
| | - Geoff Culshaw
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK
| | - Brendan Corcoran
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK
| | - Andy E Durham
- Liphook Equine Hospital, Forest Mere, Liphook, Hampshire, UK
| | | | - Bruce C McGorum
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK
| | - Peter Simmonds
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK
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Rendle DI, Rutledge F, Hughes KJ, Heller J, Durham AE. Effects of metformin hydrochloride on blood glucose and insulin responses to oral dextrose in horses. Equine Vet J 2013; 45:751-4. [PMID: 23600690 DOI: 10.1111/evj.12068] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [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: 06/08/2012] [Accepted: 01/18/2013] [Indexed: 11/28/2022]
Abstract
REASONS FOR PERFORMING STUDY Metformin is a potential therapeutic agent for the treatment of insulin resistance (IR). In laboratory animals, orally administered metformin reduces intestinal glucose absorption and may therefore affect insulinaemic responses to oral carbohydrate ingestion. OBJECTIVES To determine whether pretreatment with metformin reduces plasma glucose concentration and insulin responses following consumption of dextrose in horses. STUDY DESIGN Therapeutic cross-over study. METHODS Seven healthy Standardbred and Thoroughbred geldings were subjected to an oral dextrose challenge test on 4 occasions: with and without metformin, before and after induction of IR with dexamethasone. Metformin was administered by nasogastric tube at 30 mg/kg bwt 1 h before administration of dextrose. Glucose and insulin concentrations in plasma/serum were measured at regular intervals during each test. Linear mixed models were specified for each predetermined outcome variable, and for each model the 'treatment' was included as a fixed effect with 4 categorical levels (none, metformin, dexamethasone and dexamethasone with metformin) and horse accounted for as a random effect. RESULTS In healthy horses, the administration of metformin resulted in a statistically significant reduction in peak glucose concentration (P = 0.002), area under the glucose curve (P<0.001) and insulin concentration 120 min after dextrose administration (P = 0.011). Following the induction of IR, administration of metformin was associated with significant differences in peak glucose concentration (P<0.001), the percentage increase in glucose concentration (P = 0.010), the area under the glucose curve (P<0.001) and insulin concentration at 120 min (P = 0.034) and 150 min after dextrose administration (P = 0.014). CONCLUSIONS Metformin resulted in reduced glycaemic and insulinaemic responses both in healthy horses and in horses with experimentally induced IR. POTENTIAL RELEVANCE Metformin may benefit horses with naturally acquired IR by reducing glycaemic and insulinaemic responses to dietary nonstructural carbohydrates. Further investigations into the mechanisms of action of metformin in horses and controlled clinical trials are warranted.
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Affiliation(s)
- D I Rendle
- The Liphook Equine Hospital, Liphook, UK
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Copas VEN, Durham AE. Circannual variation in plasma adrenocorticotropic hormone concentrations in the UK in normal horses and ponies, and those with pituitary pars intermedia dysfunction. Equine Vet J 2011; 44:440-3. [PMID: 21848531 DOI: 10.1111/j.2042-3306.2011.00444.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
REASONS FOR PERFORMING STUDY Pituitary pars intermedia dysfunction (PPID) is a common endocrinopathy, frequently diagnosed via plasma adrenocorticotropic hormone (ACTH) concentrations. Seasonal variation in plasma ACTH concentrations has been described in normal horses prompting caution in diagnosing PPID at certain times of the year. The aims of this study were to determine appropriate reference intervals for equine plasma ACTH throughout the year; and to examine the circannual variation of plasma ACTH concentrations in PPID cases. HYPOTHESIS Plasma ACTH can be used as a test for PPID throughout the year with the use of appropriate reference intervals. METHODS Data for reference interval calculations were obtained from samples collected from inpatients of Liphook Equine Hospital (non-PPID group, n=156). Data from PPID cases (n=941) were obtained from samples submitted to the Liphook Equine Hospital Laboratory from horses with a clinical suspicion of PPID found to have plasma ACTH concentrations greater than our upper reference interval for that time of year. RESULTS Upper limits for reference interval of plasma ACTH were 29 pg/ml between November and July and 47 pg/ml between August and October. Circannual variation in plasma ACTH occurred in both non-PPID and PPID horses with the highest ACTH concentrations found between August and October in both groups (P<0.0001). The greatest difference between the 2 populations also occurred between August and October. CONCLUSIONS Plasma ACTH can be used for the diagnosis and monitoring of PPID throughout the year with the use of appropriate reference intervals. These findings demonstrate an increase in pituitary gland secretory activity during the late summer and autumn in both normal and PPID cases.
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Durham AE, Hughes KJ, Cottle HJ, Rendle DI, Boston RC. Type 2 diabetes mellitus with pancreatic beta cell dysfunction in 3 horses confirmed with minimal model analysis. Equine Vet J 2010; 41:924-9. [PMID: 20383993 DOI: 10.2746/042516409x452152] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Type 2 diabetes mellitus (T2DM) is diagnosed rarely in equine practice although it may be under-recognised. A greater awareness of the condition and therapeutic considerations would be to the benefit of such cases presenting in practice. More investigation into the pharmacological management of these cases is needed. OBJECTIVES Three cases of diabetes mellitus were investigated using a specific test for insulin sensitivity and pancreatic beta cell function in order to define accurately and characterise the existence of T2DM in all 3 subjects. METHODS The insulin-modified frequently sampled i.v. glucose tolerance test was performed in each case and the data so obtained were subject to minimal model analysis of insulin-glucose dynamics. Cases were then monitored following treatment using a combination of dietary modification, metformin, glibenclamide and pergolide. RESULTS Marked insulin resistance was identified in each case and, furthermore, severe pancreatic beta cell dysfunction was present therefore classifying each case as end stage T2DM. Treatment was nevertheless associated with restoration of normoglycaemia in all cases. CONCLUSIONS T2DM in horses may be more common than generally considered.In some cases individuals may respond to therapy aimed at restoring insulin sensitivity and pancreatic function. Drugs used in other species for the treatment of T2DM have not yet been adequately tested in horses. POTENTIAL RELEVANCE T2DM should be considered as an important differential diagnosis in mature to elderly horses and ponies suffering from weight loss, polydipsia and polyuria. Clinicians should be encouraged to offer treatment and management advice when such cases are encountered.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Durham AE, Smitht KC, Newton JR, Hillyer MH, Hillyer LL, Smith MRW, Marr CM. Development and application of a scoring system for prognostic evaluation of equine liver biopsies. Equine Vet J 2010; 35:534-40. [PMID: 14515951 DOI: 10.2746/042516403775467171] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY The study was designed to investigate the prognostic value of liver biopsy during investigation of cases of suspected liver disease in mature horses. HYPOTHESIS That liver biopsy is the most prognostically useful technique in common usage in the investigation of suspected liver disease. METHODS This study examined the prognostic value of liver biopsy during the investigation of suspected liver disease in 73 mature horses. Histopathological variables comprising fibrosis, irreversible cytopathology, inflammatory infiltration, haemosiderin accumulation and biliary hyperplasia were found to be significant predictors of nonsurvival and were used to formulate a weighted biopsy score representing a prognostically useful broad comparative index of histopathological severity. Minimum and maximum possible scores were 0 and 14 points, respectively. RESULTS Retrospective application of the biopsy scoring system to the study population indicated that horses with scores of 0 or 1 were equally likely to survive to 6 months with a combined mortality of 4%. Horses with biopsy scores between 2 and 6 had a combined mortality of 33% and were at a 12-fold increased risk of nonsurvival within 6 months (hazard ratio = 12.04, 95% CI 134-107.81, P = 0.026) compared to horses with a biopsy score of 0. Horses with biopsy scores between 7 and 14 had a combined mortality of 86% and were at a 46-fold increased risk of nonsurvival (hazard ratio = 46.01, 95% CI 5.92-357.5, P < 0.001) compared to horses with biopsy score 0. CONCLUSIONS Application of the biopsy scoring system to histopathological findings in liver biopsy specimens was very useful in predicting survival of cases of suspected liver disease. POTENTIAL RELEVANCE Application of the findings in this study may not be directly applicable to other case populations. However, liver biopsy appears to be the most valuable prognostic technique employed during the investigation of suspected cases of liver disease in mature horses.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Abstract
REASONS FOR PERFORMING STUDY The diagnostic value of several investigative procedures commonly used during the evaluation of suspected equine hepatopathy cases has not been specifically quantified in previous studies. HYPOTHESIS No noninvasive procedures would clearly discriminate between horses with and without significant liver disease. METHODS Histopathology of biopsy samples was used as the 'gold standard' technique for definitive diagnosis of the presence or absence of significant liver disease. Clinical, ultrasonographic and clinicopathological data obtained during the investigation of 82 suspected cases of hepatopathy in mature horses were compared with the results of subsequent biopsy in order to quantify the diagnostic value of each test. RESULTS Of the 82 cases, 61 were confirmed to have significant liver disease and 21 were not. Only serum concentrations of gamma-glutamyltransferase (gammaGT), globulins and alkaline phosphatase (AP) were found to be significantly different between the 2 groups of horses. Clinical and ultrasonographic abnormalities were found, when present, to be good indicators of the presence of liver disease. Certain single serum biochemical tests and combinations thereof were found to have high values for sensitivity (SN), specificity (SP), positive predictive value (PPV) and/or negative predictive value (NPV), but none showed high values for all 4 parameters leading to important limitations in their practical diagnostic application. Of all serum biochemical tests studied, the PPVs of only gammaGT and globulins could be clearly improved by considering especially high positive results. CONCLUSIONS The single positive test results of greatest diagnostic value were presence of hepatic encephalopathy (HE), increased gammaGT, hyperglobulinaemia, hypoalbuminaemia, increased AP, increased total bile acids (TBA) and increased total bilirubin (TBil). Increased aspartate aminotransferase (AST) and increased glutamate dehydrogenase (GLDH) were also of good diagnostic value, but only when used in combination with the above tests. However, no single, combination or sequential test was able to discriminate fully between horses with and without biopsy-confirmed liver disease and reliance on the use of noninvasive tests for the prediction of the presence or absence of significant liver disease may lead to frequent diagnostic errors. Although certain positive results did reliably predict the presence of liver disease, negative test results were invariably poor predictors of the absence of liver disease. POTENTIAL RELEVANCE Application of the findings in this study may not be directly applicable to other case populations. However, the results may help clinicians with their selection and interpretation of appropriate test results in cases of suspected liver disease.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Abstract
REASONS FOR PERFORMING STUDY Liver disease is fairly common in horses and, although previous literature suggests that fatality rates are high, impressions gained from current clinical practice suggest that this is no longer the case. OBJECTIVES A case-control study was undertaken in 2 hospitals to investigate whether age, gender or breed type predisposed horses to developing hepatic disease, with the additional aim of determining whether these factors and disease category had any effect on outcome. METHODS Eighty-eight cases were identified by review of computerised archives at 2 hospitals. Three cases admitted immediately before and after the cases were used as controls. Multivariant models were developed to explore the relationship between age, breed type and gender and the development of liver disease, and within the clinical cases, to identify whether any of these factors or specific forms of liver disease were associated with fatality rate. RESULTS Ponies were more likely to develop hepatic disease than light riding horses, but neither age nor gender were significant risk factors. Overall, the fatality rate was fairly low; horses with unclassified hepatopathies had the lowest fatality rate and those with cholangiohepatitis, pyrrolizidine alkaloid toxicity and chronic active hepatitis had significantly higher fatality rates in comparison. However, age, breed type and gender had no detectable effect on outcome. CONCLUSIONS AND POTENTIAL RELEVANCE Such data could be of particular value to equine practitioners, as the cases were drawn from both primary and referral practice, and were all seen within the last 5 years.
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Affiliation(s)
- M R W Smith
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK
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Durham AE, Phillips TJ, Walmsley JP, Newton JR. Nutritional and clinicopathological effects of post operative parenteral nutrition following small intestinal resection and anastomosis in the mature horse. Equine Vet J 2010; 36:390-6. [PMID: 15253078 DOI: 10.2746/0425164044868369] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY There is an absence of data describing the nutritional requirements and nutritional status of horses following surgery for colic; furthermore, the potential effect of parenteral nutrition (PN) on improving nutritional status in such cases is unknown. HYPOTHESIS Post operative colic cases suffer from a potentially detrimental negative energy balance and the PN formulation developed in this study would lead to clinicopathologically detectable improvements in the subjects' nutritional status. METHODS Several clinicopathological variables, some known to be associated with nutritional status, were compared in 2 groups of horses in the post operative period following colic surgery; Group N (n = 15) were treated with PN and Group C (n = 15) were starved routinely. RESULTS Group N had significantly lower serum concentrations of triglycerides, total bilirubin, albumin and urea and significantly higher serum concentrations of glucose and insulin compared with Group C in the post operative period. CONCLUSIONS The control group of horses demonstrated significant clinicopathological evidence of starvation and the described PN protocol resulted in a demonstrably improved nutritional status in the treated horses. POTENTIAL RELEVANCE Further study is required to investigate clinical benefits and possible harmful side effects of post operative parenteral nutrition before the technique can be advocated for widespread use in practice.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Durham AE, Newton JR, Smith KC, Hillyer MH, Hillyer LL, Smith MRW, Marr CM. Retrospective analysis of historical, clinical, ultrasonographic, serum biochemical and haematological data in prognostic evaluation of equine liver disease. Equine Vet J 2010; 35:542-7. [PMID: 14515952 DOI: 10.2746/042516403775467324] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [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: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Results of noninvasive tests of liver disease do not always correlate with the degree of hepatic disease nor outcome of the case. OBJECTIVE To investigate the prognostic value of data collected using noninvasive tests during the investigation of cases of suspected liver disease in mature horses. HYPOTHESIS Much of the data gathered during the investigation of suspected hepatopathy cases offers little prognostic guidance and interpretation of such data can be misleading. METHODS The results from a range of common and noninvasive diagnostic techniques applied in 116 mature horses with suspected liver disease, were assessed for their ability to predict survival within a 6 month period. RESULTS A significantly poorer prognosis was found in association with clinical signs suggestive of liver disease, presence of hepatic encephalopathy, ultrasonographic abnormalities, increased serum globulins, increased total bile acids (TBA), increased alkaline phosphatase (AP), increased gamma-glutamyl transferase (gammaGT), erythrocytosis, leucocytosis, low serum albumin and low serum urea. Additional significant novel findings of interest included an association between increased plasma fibrinogen and low serum creatinine concentrations with nonsurvival in cases of liver disease, an association between raised serum concentrations of AP and gammaGT with biliary hyperplasia and also an association between hepatic fibrosis, haemosiderosis and biliary hyperplasia with ultrasonographically detected hepatic abnormalities. CONCLUSIONS The most useful noninvasive prognostic test in cases of suspected liver disease in mature horses is the severity of clinical signs. Other data may be of some limited prognostic value. POTENTIAL RELEVANCE Application of the findings in this study may not be directly applicable to other case populations. However, the findings should at least be considered when prognosis is based on similar criteria.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Abstract
Five horses with sabulous cystitis were managed for up to three years. They were treated by emptying the bladder through a urinary catheter and saline lavage with cytoscopic guidance to remove residual sabulous material. The cystitis was treated with antimicrobial and anti-inflammatory medications, and bethanechol chloride was also administered. Frequent catheterisation and emptying of the bladder was an alternative to regular cystoscopic examination with saline lavage but it resulted in the development of a urethral stricture in one case. Four of the horses returned to work and one was retired owing to persistent incontinence.
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Affiliation(s)
- D I Rendle
- Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG
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Durham AE, Rendle DI, Newton JE. The effect of metformin on measurements of insulin sensitivity and beta cell response in 18 horses and ponies with insulin resistance. Equine Vet J 2008; 40:493-500. [PMID: 18482898 DOI: 10.2746/042516408x273648] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASONS FOR PERFORMING STUDY Laminitis in equids is a very common debilitating disease, and insulin resistance (IR) and hyperinsulinaemia are increasingly recognised as important predisposing factors. Pharmacological modification of IR and hyperinsulinaemia might reduce the risk of laminitis. HYPOTHESIS Metformin, a drug commonly prescribed for treatment of human IR, may also decrease IR in equids. METHODS Eighteen horses and ponies with IR and recurrent laminitis were treated with 15 mg/kg bwt metformin per os q. 12 h. Each animal served as its own control by comparing pre- and post treatment proxies for IR, insulin sensitivity (IS) and pancreatic beta cell function while controlling for possible dietary and managemental influences on IR. RESULTS Evidence of significantly improved IS and decreased pancreatic beta cell secretion was found following metformin treatment. The magnitude of effect was greater at earlier resampling (6-14 days) than at later times (23-220 days). Apparent subjective clinical benefits were good but less favourable than effects on IR. CONCLUSIONS Metformin is safe and appears to increase IS in equids. POTENTIAL RELEVANCE Metformin may be indicated as a treatment for IR in equids. Further studies are required to define appropriate selection of subjects warranting therapy, dosing schedule and pharmacokinetics.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG, UK
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Rendle DI, Durham AE, Bestbier M, Smith KC, Boswell JC. Neurenteric cyst with associated butterfly vertebrae in a seven-month-old colt. Vet Rec 2008; 162:558-61. [PMID: 18441354 DOI: 10.1136/vr.162.17.558] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- D I Rendle
- Liphook Equine Hospital, Forest Mere, Liphook, Hampshire, UK
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Abstract
Five ponies and one donkey with hyperlipaemia that occurred secondarily to a variety of primary clinical conditions were treated with lipid-free partial parenteral nutrition comprising equal volumes of 50 per cent glucose and 15 per cent amino acids. The infusion supplied energy and protein at rates of 2.6 kJ/kg per hour and 34.3 mg/kg per hour, respectively. In all six cases there was a prompt and sustained decrease in serum concentrations of triglyceride. In four of the six cases a good response to treatment of the primary condition was also seen and the subjects were discharged successfully. In the remaining two cases, poor clinical response of the primary condition resulted in euthanasia, although hyperlipaemia was nevertheless resolved. The main complication of parenteral nutrition was hyperglycaemia.
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Affiliation(s)
- A E Durham
- Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG
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Packer M, Patterson-Kane JC, Smith KC, Durham AE. Quantification of Immune Cell Populations in the Lamina Propria of Equine Jejunal Biopsy Specimens. J Comp Pathol 2005; 132:90-5. [PMID: 15629483 DOI: 10.1016/j.jcpa.2004.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [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: 02/13/2004] [Accepted: 06/07/2004] [Indexed: 11/17/2022]
Abstract
The histological diagnosis of inflammatory bowel disease (IBD) in horses and other species is subjective, and pathological assessments vary considerably as a result. One important criterion is increased infiltration of the lamina propria by eosinophils, plasma cells, lymphocytes or macrophages, but this is difficult to assess without a knowledge of the normal immune cell populations and potential for individual variation. Retrospective jejunal specimens were analysed from 14 horses aged 13-15 years which had not shown clinical or post-mortem signs of gastrointestinal disease. Populations of plasma cells, T lymphocytes (CD3+), B lymphocytes (CD79a+ cytoplasmic membranes), eosinophils, macrophages and neutrophils were counted in 9000-microm2 areas of the villous lamina propria and intercryptal lamina propria for each horse. There were significantly higher counts of plasma cells, B lymphocytes and eosinophils in the intercryptal than in the villous region, which accords with previous findings in dogs. This information will be used as control data for future quantitative morphometrical analysis of immune cells in small intestinal specimens from horses in which IBD has been diagnosed.
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Affiliation(s)
- M Packer
- Department of Pathology and Infectious Diseases, The Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA, UK
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Abstract
Several clinical variables were compared in two groups of 15 horses recovering from resection and anastomosis of a strangulated small intestine; 15 were treated with parenteral nutrition and 15 were starved routinely. There was some evidence that parenteral nutrition had a short-lived adverse effect on both the catheter sites and gastric emptying, but there were no marked adverse clinical effects and no evidence of any improvement in the horses' condition.
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Affiliation(s)
- A E Durham
- The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG
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Moxon W, Durham AE. On a Case of Abdominal Aneurism cured by Compression of the Aorta. J R Soc Med 1872; 55:213-224.1. [PMID: 20896387 DOI: 10.1177/095952877205500111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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