Analyze Diet

Topic:Analytical Methods

Analytical methods in equine research encompass a variety of scientific techniques and tools used to study and evaluate different aspects of horse health, performance, and physiology. These methods help advance our understanding of equine biology, diagnosing conditions, and improving management practices. Common analytical methods include molecular techniques like PCR and ELISA for detecting pathogens and measuring biomarkers, imaging technologies such as ultrasound and MRI for assessing musculoskeletal health, and statistical models for analyzing genetic data and performance metrics. This page compiles peer-reviewed research studies and scholarly articles that explore the development, application, and impact of various analytical methods in equine science.
The concentration of lidocaine and mepivacaine measured in synovial fluid of different joints of horses after single intra-articular injection.
Frontiers in veterinary science    November 10, 2022   Volume 9 1007399 doi: 10.3389/fvets.2022.1007399
Adler DMT, Jørgensen E, Cornett C.To determine the synovial fluid (SF) concentrations of lidocaine and mepivacaine after intra-articular injection with clinically relevant doses to the distal interphalangeal (DIP), metacarpophalangeal (MCP), middle carpal (MC), and tarsocrural (TC) joint at two different time points after injection in order to be able to compare concentrations with previously established concentrations associated with cytotoxicity and antimicrobial activity. Unassigned: In the first of two experiments, 20 joints (5 MC, 5 MCP, 10 DIP joints) of five horses under general anesthesia were injected with clinically ...
Administration and detection of gene therapy in horses: A systematic review.
Drug testing and analysis    November 7, 2022   Volume 15, Issue 2 143-162 doi: 10.1002/dta.3394
Haughan J, Ortved KF, Robinson MA.Gene therapy uses genetic modification of cells to produce a therapeutic effect. Defective or missing genes can be repaired or replaced, or gene expression can be modified using a variety of technologies. Repair of defective genes can be achieved using specialized gene editing tools. Gene addition promotes gene expression by introducing synthetic copies of genes of interest (transgenes) into cells where they are transcribed and translated into therapeutic proteins. Protein production can also be modified using therapies that regulate gene expression. Gene therapy is currently prohibited in bot...
Hierarchical modeling of elastic moduli of equine hoof wall.
Journal of the mechanical behavior of biomedical materials    October 23, 2022   Volume 136 105529 doi: 10.1016/j.jmbbm.2022.105529
Shiang CA, Bonney C, Lazarus B, Meyers M, Jasiuk I.This study predicts analytically effective elastic moduli of substructures within an equine hoof wall. The hoof wall is represented as a composite material with a hierarchical structure comprised of a sequence of length scales. A bottom-up approach is employed. Thus, the outputs from a lower spatial scale serve as the inputs for the following scale. The models include the Halpin-Tsai model, composite cylinders model, a sutured interface model, and classical laminate theory. The length scales span macroscale, mesoscale, sub-mesoscale, microscale, sub-microscale, and nanoscale. The macroscale re...
Commercial Hair Analysis in Horses: A Tool to Assess Mineral Intake?
Journal of equine veterinary science    October 22, 2022   Volume 119 104145 doi: 10.1016/j.jevs.2022.104145
Wahl L, Vervuert I.The use of hair samples to assess the mineral intake of horses under practical conditions has recently been attracting increased interest. The aims of this study were to compare mineral analysis results in equine mane hair between three commercial laboratories and to determine the relationship between the mineral intake and mineral content in mane hair. Four warmblood horses (14 ± 3 years) were included in the study. Horses were fed hay ad libitum and a commercial mineral supplement to meet nutrient requirements under maintenance conditions. Mane hair from the hairline was collected with a sa...
Generic approach for the discovery of drug metabolites in horses based on data-dependent acquisition by liquid chromatography high-resolution mass spectrometry and its applications to pharmacokinetic study of daprodustat.
Analytical and bioanalytical chemistry    October 1, 2022   Volume 414, Issue 28 8125-8142 doi: 10.1007/s00216-022-04347-2
Ishii H, Shibuya M, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Sato F, Kuroda T, Yamada M, Leung GN.In drug metabolism studies in horses, non-targeted analysis by means of liquid chromatography coupled with high-resolution mass spectrometry with data-dependent acquisition (DDA) has recently become increasingly popular for rapid identification of potential biomarkers in post-administration biological samples. However, the most commonly encountered problem is the presence of highly abundant interfering components that co-elute with the target substances, especially if the concentrations of these substances are relatively low. In this study, we evaluated the possibility of expanding DDA coverag...
Determination of hair cortisol in horses: comparison of immunoassay vs LC-HRMS/MS.
Analytical and bioanalytical chemistry    September 22, 2022   Volume 414, Issue 28 8093-8105 doi: 10.1007/s00216-022-04343-6
The measure of hair cortisol concentration (HCC) is becoming an emerging approach to monitor mid-/long-term stress in animals, so it is more and more important to develop accurate and reliable methods. In the light of this, the aim of the present study was to compare mane HCCs of 47 horses with different managements, by means of an immunoassay (ELISA) and liquid chromatography coupled to hybrid high-resolution mass spectrometry (LC-HRMS/MS). After the washing step, the ground hair was extracted with methanol. The extract was evaporated and redissolved in two different aqueous solutions, depend...
Additional studies on nicotine exposure in horses: Accurate quantification and elimination profiles of potential biomarkers in plasma and urine.
Rapid communications in mass spectrometry : RCM    September 14, 2022   Volume 36, Issue 23 e9396 doi: 10.1002/rcm.9396
Ishii H, Shibuya M, Leung GN, Yamashita S, Nagata SI, Kushiro A, Sakai S, Toju K, Okada J, Kawasaki K, Kusano K, Kijima-Suda I.For the purpose of doping control, this is the first report of accurate quantification of four critical structural isomers of nicotine metabolites (trans-3'-hydroxycotinine, cis-3'-hydroxycotinine, 5'-hydroxycotinine, and N'-hydroxymethylnorcotinine) in equine plasma and urine for the establishment of their elimination profiles. Besides, the pharmacokinetic studies of trans-3'-hydroxycotinine and N'-hydroxymethylnorcotinine in equine plasma and urine are also presented for the first time. Methods: The accurate quantification methods of the aforementioned four structural isomers in horse plasma...
Analysis of the effect of 1-Allyl-3-Methylimidazolium chloride on thermodynamic stability, folding kinetics, and motional dynamics of horse cytochrome c.
Biophysical chemistry    September 8, 2022   Volume 290 106892 doi: 10.1016/j.bpc.2022.106892
Garg M, Sharma D, Kumar R.1-allyl-3-methylimidazolium chloride (AMIMCl) acts as a potential green solvent for proteins. The present work provides a possible pathway by which the structural, kinetic, thermodynamic, and folding properties of horse cytochrome c (cyt c) are affected in green aqueous-AMIMCl systems. Analysis of the effect of AMIMCl on thermodynamic stability, refolding/unfolding kinetics, and motional dynamics of cyt c provided important information, (i) AMIMCl decreases the thermodynamic stability of reduced cyt c and also strengthens the guanidinium chloride (GdmCl)-mediated decrease in thermodynamic stab...
Pharmacokinetic Study of Vadadustat and High-Resolution Mass Spectrometric Characterization of its Novel Metabolites in Equines for the Purpose of Doping Control.
Current drug metabolism    August 27, 2022   Volume 23, Issue 10 850-865 doi: 10.2174/1389200223666220825093945
Ishii H, Shibuya M, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Sato F, Kuroda T, Yamada M, Leung GN.Vadadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitor, is a substance which carries a lifetime ban in both horse racing and equestrian competition. A comprehensive metabolic study of vadadustat in horses has not been previously reported. Objective: Metabolism and elimination profiles of vadadustat in equine plasma and urine were studied for the purpose of doping control. Methods: A nasoesophageal administration of vadadustat (3 g/day for 3 days) was conducted on three thoroughbred mares. Potential metabolites were comprehensively detected by differential analysis of ful...
Direct 14C dating of equine products preserved in archaeological pottery vessels from Botai and Bestamak, Kazakhstan.
Archaeological and anthropological sciences    August 18, 2022   Volume 14, Issue 9 175 doi: 10.1007/s12520-022-01630-2
Casanova E, Knowles TDJ, Outram AK, Stear NA, Roffet-Salque M, Zaibert V, Logvin A, Shevnina I, Evershed RP.Direct and accurate radiocarbon dating of lipid residues preserved in ceramics is a recently established method that allows direct dating of specific food products and their inception in human subsistence strategies. The method targets individual fatty acids originating from animal fats such as ruminant dairy, ruminant adipose, non-ruminant adipose and aquatic fats. Horse lipid residues found in Central Asian pottery vessels are also directly dateable using this new method. Here we present the identification of equine lipid residues preserved in two pottery assemblages from the Neolithic and E...
A fully automated method to quantitate total carbon dioxide in equine plasma by headspace GCMS.
Drug testing and analysis    August 16, 2022   Volume 14, Issue 10 1724-1731 doi: 10.1002/dta.3353
Zahra PW, Jayasinghe NS, Selvadurai NS, Willers SJ, Krsta D, Batty DC, Vine JH.Pre-race dosing of horses with alkalinising agents to manipulate performance has been evident in racing worldwide for over 30 years. To regulate the use of alkalinising agents, racing authorities adopted thresholds for total plasma carbon dioxide (TCO ) in racehorses. Traditionally, racing laboratories have measured plasma TCO using ion selective electrode (ISE) technology, with the Association of Official Racing Chemists (AORC) approving the use of only three ISE instruments for measurement. Because of the manufacture and support of these instruments ceasing, racing laboratories have explor...
Evaluation of hair analysis for determination of trace mineral status and exposure to toxic heavy metals in horses in the Netherlands. van der Merwe D, van den Wollenberg L, van Hees-Valkenborg J, de Haan T, van der Drift S, Vandendriessche V.Analysis of hair to gain insight into the trace mineral status and exposure to toxic heavy metals of horses is attractive because hair is an easily accessible sample material. To investigate the potential value of hair analysis in horses for determination of trace mineral and heavy metal concentrations, we analyzed mane hair and liver samples from 62 horses presented for slaughter at a facility in the Netherlands that receives horses from all regions of the country. Hair samples were cleaned in warm water. After acid digestion of hair and liver specimens, we quantified, with inductively couple...
Simultaneous quantification of caffeine and its main metabolites by gas chromatography mass spectrometry in horse urine.
Biomedical chromatography : BMC    July 15, 2022   Volume 36, Issue 10 e5445 doi: 10.1002/bmc.5445
Göktaş EF, Kabil E, Yatanaslan L, Güneş E, Dirikolu L.Caffeine is a naturally occurring alkaloid and it is metabolized to paraxanthine, theophylline and theobromine. Analysis of caffeine and its metabolites is challenging since the metabolites theophylline and paraxanthine generate similar product and precursor ions. In this study, a new method was developed for the simultaneous analysis of caffeine, paraxanthine, theobromine and theophylline in horse urine using gas chromatography-mass spectrometry (GC-MS). Urine samples were treated using solid-phase extraction followed by the elution with dichloromethane-isopropanol (90:10) after the pH was ad...
Application of Fourier transform infrared spectroscopy (FTIR) techniques in the mid-IR (MIR) and near-IR (NIR) spectroscopy to determine n-alkane and long-chain alcohol contents in plant species and faecal samples.
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy    June 21, 2022   Volume 280 121544 doi: 10.1016/j.saa.2022.121544
Ferreira L, Machado N, Gouvinhas I, Santos S, Celaya R, Rodrigues M, Barros A.n-Alkanes and long-chain alcohols (LCOH) have been used as faecal markers to assess the feeding behaviour of both wild and domestic herbivore species. However, their chemical analysis is time-consuming and expensive, making it necessary to develop more expeditious methodologies to evaluate concentrations of these markers. This work aimed to evaluate the use of Fourier Transform Infrared Spectroscopy (FTIR) technology in the near infrared (NIR) and mid infrared (MIR) intervals, for the determination of n-alkane and LCOH concentrations of different plant species and faecal samples of domestic he...
Characterization of growth hormone secretagogue small molecule ibutamoren (MK-0677) and its possible metabolites in thoroughbred horses for doping control.
Rapid communications in mass spectrometry : RCM    June 19, 2022   Volume 36, Issue 18 e9337 doi: 10.1002/rcm.9337
Philip M, Karakka Kal AK, Subhahar MB, Karatt TK, Mathew B, Koshy SA.It is important to remember that performance-enhancing agents such as non-peptide growth hormone secretagogues present a significant risk of abuse. Ibutamoren (MK-0677) is a potent, long-acting, selective non-peptide growth hormone secretagogue that can be taken orally. Methods: This study examines ibutamoren and its metabolites in thoroughbred horses after oral administration. Liquid chromatography/high-resolution mass spectrometry was used to determine the probable structures of the detected metabolites. Results: In this study, 22 metabolites of ibutamoren were identified (17 phase I and 5 p...
Pharmacokinetics of grapiprant and effects on TNF-alpha concentrations following oral administration to horses.
Journal of veterinary pharmacology and therapeutics    June 1, 2022   Volume 45, Issue 5 467-472 doi: 10.1111/jvp.13076
Hoffmann SL, Seminoff K, McKemie DS, Kass PH, Knych HK.Grapiprant is a prostaglandin E2 receptor antagonist that has been found to be an effective anti-inflammatory in dogs and that is devoid of some of the adverse effects associated with traditional NSAIDs that elicit their effects through inhibition of PGE2 production. Previously published reports have described the pharmacokinetics of this drug in horses when administered at 2 mg/kg; however, pharmacodynamic effects in this species have yet to be described. The objective of the current study was to describe the pharmacokinetics and pharmacodynamics of grapiprant at a higher dose. Eight horses...
Development of a Microsphere-Based Immunoassay Authenticating A2 Milk and Species Purity in the Milk Production Chain.
Molecules (Basel, Switzerland)    May 17, 2022   Volume 27, Issue 10 3199 doi: 10.3390/molecules27103199
Elferink AJW, Entiriwaa D, Bulgarelli P, Smits NGE, Peters J.Processed milk and milk products produced from bovine milk, commonly contain β-casein A1 (βCA1) and β-casein A2 (βCA2). Since the presence of βCA1 is linked to milk intolerance and digestion problems, A2A2 milk, which only contains βCA2, is proposed as a healthier alternative. To support this health claim, the purity of A2A2-milk has to be guaranteed. In the presented study, a multiplex immunoassay, able to distinguish between βCA2 and βCA1, was developed and real-life applicability was shown on raw milk samples from genotyped A1A1, A1A2 and A2A2 cows. Because of its ability to discrim...
A quantitative method for the simultaneous detection of SR9009 and SR9011 in equine plasma using liquid chromatography-electrospray ionization-tandem mass spectrometry.
Drug testing and analysis    April 19, 2022   Volume 14, Issue 8 1532-1538 doi: 10.1002/dta.3271
Kwak YB, Yu J, Yoo HH.SR9009 and SR9011 are metabolic modulators pharmacologically targeting REV-ERB receptors as synthetic agonists. A liquid chromatography-tandem mass spectrometry method for the detection of SR9009 and SR9011 in equine plasma was developed and validated. Plasma samples were pretreated by protein precipitation with methanol and were loaded onto an ACQUITY ultra performance liquid chromatography high-strength silica C18 column (2.1 × 150 mm, 1.8 μm) for chromatographic separation. The mobile phase consisted of 5-mM ammonium formate (pH 3.0) in distilled water and 0.1% formic acid in ac...
Pharmacokinetics of glaucine after intravenous and oral administrations and detection of systemic aporphine alkaloids after ingestion of tulip poplar shavings in horses.
Journal of veterinary pharmacology and therapeutics    April 8, 2022   Volume 45, Issue 3 273-282 doi: 10.1111/jvp.13057
Haughan JE, Missanelli JR, You Y, Stefanovski D, Soma LR, Robinson MA.Glaucine, an aporphine alkaloid with anti-tussive, anti-inflammatory, and anti-nociceptive properties, has been identified in post-race samples from racehorses. To investigate pharmacokinetics of glaucine in horses, a three-way crossover study of intravenous and oral glaucine (0.1 mg/kg) and orally administered tulip poplar shavings (50 g shavings = 0.001 mg/kg glaucine) was performed in six horses. A two-compartment model best described IV administration with alpha ( ) and beta ( ) half-life lives of 0.3 (0.1-0.7) and 3.1 (2.4-7.8) h, respectively. The area under the curve ( ) was ...
Equine metabolism of the growth hormone secretagogue MK-0677 in vitro and in urine and plasma following oral administration.
Drug testing and analysis    March 25, 2022   Volume 14, Issue 7 1273-1290 doi: 10.1002/dta.3252
Cutler C, Viljanto M, Taylor P, Habershon-Butcher J, Van Eenoo P.Ibutamoren mesylate, or MK-0677, is an orally active, nonpeptide growth hormone secretagogue that has been developed to stimulate excretion of endogenous growth hormone. It has been evaluated for the treatment of a range of clinical conditions but is not available therapeutically. Nonetheless, MK-0677 is widely available to purchase online, sold as 'supplement' products. The mode of action and relative ease of purchase make MK-0677 a potential threat with regard to sports doping. The aim of this study was to investigate the metabolism of MK0677 in the horse following in vitro incubation and or...
Technical Note: A method for determination of titanium dioxide concentration in fecal samples.
Journal of animal science    March 10, 2022   Volume 100, Issue 3 skac074 doi: 10.1093/jas/skac074
Fowler AL, Hayes SH, Crum AD, Lawrence LM.Titanium dioxide has been used as a marker for determining diet digestibility indirectly, but some authors have expressed difficulty in measuring TiO2 concentrations in fecal material. We developed an accurate and precise method to determine TiO2 concentrations in equine feces. The method includes dry-ashing samples, digestion with (NH4)2SO4 in concentrated sulfuric acid, followed by the addition of H2O2 to produce a yellow to orange color that can be read spectrophotometrically. Accuracy was tested by spike recovery, and precision was tested by examining the coefficient of variation (CV) betw...
Metabolomics in clinical and forensic toxicology, sports anti-doping and veterinary residues.
Drug testing and analysis    March 8, 2022   Volume 14, Issue 5 794-807 doi: 10.1002/dta.3245
Keen B, Cawley A, Reedy B, Fu S.Metabolomics is a multidisciplinary field providing workflows for complementary approaches to conventional analytical determinations. It allows for the study of metabolically related groups of compounds or even the study of novel pathways within the biological system. The procedural stages of metabolomics; experimental design, sample preparation, analytical determinations, data processing and statistical analysis, compound identification and validation strategies are explored in this review. The selected approach will depend on the type of study being conducted. Experimental design influences ...
Identification of potential biomarkers in urine and plasma after consumption of tobacco product in horses.
Drug testing and analysis    March 7, 2022   Volume 14, Issue 5 902-914 doi: 10.1002/dta.3242
Ishii H, Leung GN, Yamashita S, Nagata SI, Kushiro A, Sakai S, Toju K, Okada J, Kawasaki K, Kusano K, Kijima-Suda I.The use of nicotine stimulants in horses is generally banned in horse racing and equestrian sports-accidental consumption of tobacco products is one of the possible causes of nicotine exposure in horses. The authors recently reported a comprehensive metabolic study of nicotine in equines, differentiating between nicotine exposure and sample contamination by means of a nicotine biomarker trans-3'-hydroxycotinine. To identify potential biomarkers for the differentiation of genuine nicotine administration and consumption of tobacco products, tobacco leaves (equivalent to 250 mg of nicotine) wer...
Long-term monitoring of IOX4 in horse hair and its longitudinal distribution with segmental analysis using liquid chromatography/electrospray ionization Q Exactive high-resolution mass spectrometry for the purpose of doping control.
Drug testing and analysis    March 7, 2022   Volume 14, Issue 7 1244-1254 doi: 10.1002/dta.3247
Ishii H, Shibuya M, So YM, Wong JKY, Ho ENM, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Yamada M, Leung GN.IOX4, a hypoxia-inducible factor stabilizer, is classified as a banned substance for horses in both horse racing and equestrian sports. We recently reported the pharmacokinetic profiles of IOX4 in horse plasma and urine and also identified potential monitoring targets for the doping control purpose. In this study, a long-term longitudinal analysis of IOX4 in horse hair after a nasoesophageal administration of IOX4 (500 mg/day for 3 days) to three thoroughbred mares is presented for the first time for controlling the abuse/misuse of IOX4. Six bunches of mane hair were collected at 0 (pre), ...
Measurements of hydrocortisone and cortisone for longitudinal profiling of equine plasma by liquid chromatography-tandem mass spectrometry.
Drug testing and analysis    March 4, 2022   Volume 14, Issue 5 943-952 doi: 10.1002/dta.3244
Tou K, Cawley A, Bowen C, Sornalingam K, Fu S.The conventional detection of exogenous drugs in equine doping samples has been used for confirmation and subsequent prosecution of participants responsible. In recent years, alternative methods using indirect detection have been investigated due to the expanding number of pharmaceutical agents available with the potential of misuse. The monitoring of endogenous biomarkers such as hydrocortisone (HC) has been studied in equine urine with an international threshold of 1 μg/ml established; however, there is no current threshold for equine plasma. The aim of this research was to investigate pl...
Profiling Urinary Sulfate Metabolites With Mass Spectrometry.
Frontiers in molecular biosciences    February 23, 2022   Volume 9 829511 doi: 10.3389/fmolb.2022.829511
Fitzgerald CCJ, Hedman R, Uduwela DR, Paszerbovics B, Carroll AJ, Neeman T, Cawley A, Brooker L, McLeod MD.The study of urinary phase II sulfate metabolites is central to understanding the role and fate of endogenous and exogenous compounds in biological systems. This study describes a new workflow for the untargeted metabolic profiling of sulfated metabolites in a urine matrix. Analysis was performed using ultra-high-performance liquid chromatography-high resolution tandem mass spectrometry (UHPLC-HRMS/MS) with data dependent acquisition (DDA) coupled to an automated script-based data processing pipeline and differential metabolite level analysis. Sulfates were identified through -means clustering...
Analytical documentation of an Arabian horse fatality related to Oenanthe crocata poisoning.
Toxicon : official journal of the International Society on Toxinology    February 18, 2022   Volume 210 39-43 doi: 10.1016/j.toxicon.2022.02.009
Gish A, Robveille C, Gicquel T, Allorge D, Gault G, Gaulier JM.Analytical detection of Oenanthe crocata toxins in biological samples is challenging because of their instability, the lack of commercially available standards and the exceptionally low detection of these molecules using mass spectrometry. This work aims to report the used analytical methods that allowed identification of the main plant toxins in biological samples from an equid (an Arabian horse) fatality related to hemlock water dropwort (Oenanthe crocata Linnaeus) intake. Using both LC-DAD and LC-HRMS methods allowed identification (i) of oenanthotoxin in roots found on the site, root fragm...
Pharmacokinetics of a single dose of oclacitinib maleate as a top dress in adult horses.
Journal of veterinary pharmacology and therapeutics    January 30, 2022   Volume 45, Issue 3 320-324 doi: 10.1111/jvp.13043
Hunyadi L, Datta P, Rewers-Felkins K, Sundman E, Hale T, Fajt V, Wagner S.The objective of this study was to determine the pharmacokinetic parameters of oclacitinib maleate as a top dress given to adult horses. Six adult horses with a mean weight of 528 kg were administered a single dose of 0.5 mg/kg oclacitinib maleate. Blood was collected prior to drug administration and at 15 min, 30 min, 45 min, 1, 2, 4, 6, 8, 12, 24, 48, and 72 h after treatment. Oclacitinib maleate plasma concentrations were measured by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were found best to fit a one-compartment model. Mean C was 486 ng/ml (range 423-549Â...
Suspensory ligament size does not change after plantar fasciotomy and neurectomy of the deep branch of the lateral plantar nerve by ultrasonographic assessment.
Veterinary surgery : VS    December 31, 2021   Volume 51, Issue 2 259-269 doi: 10.1111/vsu.13757
Scharf A, de Solis CN, Sampson SN, Glass K, Watts AE.To determine the short-term effect of plantar fasciotomy and neurectomy (PFN) of the deep branch of the lateral plantar nerve on the proximal suspensory ligament (PSL) cross-sectional area (CSA) in horses with hindlimb proximal suspensory desmopathy (PSD). Methods: Analytical, observational, cohort study. Methods: Twenty-one horses. Methods: Records of horses with chronic PSD treated by PFN were included if a preoperative ultrasonographic examination was available and at least one postoperative ultrasonographic examination. One masked observer measured the ultrasonographic cross-sectional area...
Defining the specificity of recombinant human erythropoietin confirmation in equine samples by liquid chromatography-tandem mass spectrometry.
Drug testing and analysis    December 21, 2021   Volume 14, Issue 4 676-689 doi: 10.1002/dta.3210
Timms M, Steel R.The proteotypic human EPO peptides YLLEAK (T4), SLTTLLR (T11), TITADTFR (T14), and VYSNFLR (T17) are often used to confirm the presence of recombinant human EPO (rhEPO) in equine samples. Each of these peptides contains one or more isomeric leucine or isoleucine amino acids, raising the possibility that a simple leucine/isoleucine substitution could lead to a false identification when compared with a rhEPO reference standard. To examine this possibility variants of these four peptides were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These studies indicate that confir...
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