Laboratory methods in equine research encompass a variety of techniques and procedures used to analyze biological samples from horses to study health, disease, genetics, and physiology. These methods include hematological analyses, biochemical assays, molecular biology techniques, and microbiological cultures. Commonly utilized laboratory techniques involve blood tests for complete blood count (CBC) and serum chemistry, polymerase chain reaction (PCR) for genetic and infectious disease studies, and enzyme-linked immunosorbent assays (ELISA) for detecting specific proteins or antibodies. These methods provide valuable data that contribute to understanding equine health and disease mechanisms. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and outcomes of laboratory methods in the context of equine research.
Kato H, Youn HY, Ohashi T, Watari T, Goitsuka R, Tsujimoto H, Hasegawa A.Using lipopolysaccharide (LPS)-stimulated equine peripheral blood mononuclear cell (PBMC) cDNA as a template, we performed polymerase chain reaction (PCR) amplification with equine interleukin-1 beta (IL-1 beta) specific primers. Electrophoresis of the PCR product on agarose gel revealed an additional smaller fragment that hybridized with an equine IL-1 beta cDNA probe. Sequencing of this fragment demonstrated that it was shorter than normal equine IL-1 beta cDNA by 162 nucleotides, which corresponded to exon 5 of the human and murine IL-1 beta genes. The deletion of 162 nucleotides did not re...
Ihler CF, Bjørn H.Ten stables were included in a study to evaluate two in vitro methods for the detection of anthelmintic resistance in cyathostomes by comparing a faecal egg count reduction test (FECRT) to a larval development assay (LDA) and an egg hatch assay (EHA). The LDA was used in seven stables and EHA in the last three. On the basis of FECR values, resistance to benzimidazoles was detected in eight of the ten small strongyle populations. Resistance to pyrantel pamoate and ivermectin was not detected. The mean concentrations that inhibited hatching in 50% of the eggs (EC50), using thiabendazole (TBZ) in...
Black SB, Stenhouse AM, Hansson RC.This paper details various rapid and sensitive methods for the extraction and derivatisation of propranolol, metoprolol, sotalol, atenolol, pindolol, timolol, oxprenolol, alprenolol and penbutolol in equine urine and in human post mortem whole blood and urine. Three solid-phase extraction methods are described involving the use of either XtrackT XRDAH515, Bond Elut Certify or Sep-Pak C18 cartridges. Two derivatisation methods are also described involving the formation of cyclised silyl or pentafluoropropionate derivatives with either chloromethyldimethylchlorosilane or pentafluoropropionic anh...
Hoshino M, Kawata Y, Goto Y.GroEL interacts with proteins in denatured states and promotes their efficient folding. To understand the conformational features required for the substrate, we studied the interactions of GroEL with various derivatives of horse cytochrome c including porphyrin-cytochrome c, apo-cytochrome c, and the three fragments containing the heme group, i.e. fragments 1-65, 1-38 and 11-21. Size-exclusion chromatography was performed, taking advantage of the heme absorption of the fluorescence label. Under low-salt conditions, significant binding to GroEL was observed for porphyrin-cytochrome c, apo-cytoc...
Ishida N, Hasegawa T, Oyunsuren T, Mukoyama H.The mitochondrial DNA sequence of cytochrome b gene in a Thoroughbred horse was determined. By comparing DNA sequences between the Thoroughbred and published sequence data (two horses and one Grevyi zebra), polymerase chain reaction (PCR) primers were designed for amplification of a 590 bp DNA fragment in the cytochrome b gene, and PCR-restriction fragment length polymorphism (RFLP) analysis was studied in 140 horses of six breeds using three restriction enzymes (AciI, BamHI, RsaI). Two morphs were found using each of the three enzymes. By combining three enzymes morphs, the 140 horses examine...
Rivero JL, Talmadge RJ, Edgerton VR.The aim of this study was to characterize the myosin heavy chain (MyHC) isoforms present in equine skeletal muscle. Methods: Muscle biopsies were removed from the superficial region of the gluteus medius muscle of five mature horses and analyzed by immunohistochemistry (using a battery of monoclonal antibodies specific for rat MyHC isoforms) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results: Immunohistochemistry allowed subdivision of three different muscle fiber populations containing a single MyHC, one slow and two fast, and two hybrid populations, one containing slow an...
Wilson SM, Rakhit S, Murdoch R, Pediani JD, Elder HY, Baines DL, Ko WH, Wong PY.Experiments were undertaken using cultured equine sweat gland epithelial cells that express purine receptors belonging to the P2U subclass which allow the selective agonist uridine triphosphate (UTP) to increase the concentration of intracellular free Ca2+ ([Ca2+]i). Experiments using pertussis toxin (Ptx), which inactivates certain guanine-nucleotide-binding proteins (G-proteins), showed that this response consisted of Ptx-sensitive and Ptx-resistant components, and immunochemical analyses of the G-protein alpha subunits present in the cells showed that both Ptx-sensitive (alpha i1-3) and Ptx...
Adler CP, Friedburg H, Herget GW, Neuburger M, Schwalb H.DNA content, ploidy level, cell size and nuclear number were investigated in 54 mammalian hearts from nine species. DNA content was determined biochemically and ploidy level of cells was studied by the means of Feulgen cytophotometry. Nuclear number was calculated by a new method, while cell size was determined by using ocular micrometry. In most mammals diploid cell nuclei predominate. Higher ploidy levels were found in the human and the pig hearts. The total amount of DNA correlated with the myocardial weight. Eight million heart muscle cell nuclei were found in mice (myocardial weight 160 m...
Sellon DC, Walker KM, Russell KE, Perry ST, Fuller FJ.Equine infectious anemia virus (EIAV) is a lentivirus that replicates predominantly in mature tissue macrophages. Viral expression is strongly influenced by the state of differentiation of the host cell. While blood monocytes can be infected, viral transcription is limited until the cell differentiates into a mature macrophage. Activation of mature macrophages infected with EIAV might also alter viral expression, presumably through binding of cellular transcription factors to viral nucleic acid sequences within the long terminal repeat (LTR). Using DNA amplification techniques, we compared LTR...
Gasser RB, Stevenson LA, Chilton NB, Nansen P, Bucknell DG, Beveridge I.Five species of equine strongyle belonging to the subfamily Strongylinae (Strongylus edentatus, S. equinus, S. vulgaris, Oesophagodontus robustus and Triodontophorus serratus) and 11 species belonging to the subfamily Cyathostominae (Poteriostomum imparidentatum, P. ratzii, Cylicocyclus insignis, Cc. leptostomus, Cc. nassatus, Cylicostephanus calicatus, Cs. longibursatus, Cs. goldi, Cyathostomum catinatum, Cy. labiatum and Cy. pateratum) were characterized using a polymerase chain reaction-linked restriction fragment length polymorphism technique (PCR-RFLP). Internal transcribed spacer ribosom...
Aramaki S, Ishidaka O, Suzuki E, Momose A, Umemura K.In a doping test for racing horses, it is useful for the elucidation of the illegal use of drugs if one can estimate the time at which the detected drug was administered. In order to estimate the time which has elapsed after the administration of caffeine (CA) into horses, the ratios of concentration for the respective metabolites to the unchanged CA in the plasma or the urine were determined. These ratios have been known to be independent of the dose of CA. The relationship between [plasma or urinary concentration of a metabolite]/ [plasma or urinary concentration of the unchanged drug] and t...
Zhang XY, Zhu FX, Robinson NE.We examined the effect of activation of beta 2-adrenoceptor (AR) by isoproterenol (ISO) on acetylcholine (ACh) release evoked by electrical field stimulation (EFS: 20 V, 0.5 Hz, 0.5 msec) from cholinergic nerves in five regions of equine airways. We also tested if the effect of ISO was dependent on epithelium or prostanoids by examining the effect of ISO on ACh release in the presence and absence of epithelium or cyclooxygenase inhibition. Trachealis strips or bronchial rings were preincubated for 60 min with 10(-7) M atropine, 10(-6) M neostigmine, and 10(-5) M guanethidine. The ACh amount wa...
Grøndahl C, Hyttel P.The nucleolus is believed to be the active site of rRNA synthesis in all eukaryotic cells. In preimplantation embryos, the embryonic genome is apparently more or less silent up to a species-specific developmental stage at which a major burst of transcription occurs. Here we report on nucleologenesis and some ultrastructural aspects of the onset of RNA synthesis in equine embryos during in vivo development. The zygotes and embryos up to blastocyst stages were surgically recovered from normally cycling mares. Mares were induced to ovulate by treatment with 3000 IU hCG and inseminated 20 and 34 h...
Almadhidi J, Moslemi S, Drosdowsky MA, Séralini GE.Aromatase (estrogen synthetase) is a steroidogenic enzyme complex which catalyzes the conversion of androgens to estrogens (termed aromatization). This enzyme was purified from adult equine testis to homogeneity by five chromatographic steps. The ability of purified and reconstituted equine aromatase to exhibit an estrogen 2-hydroxylase activity was tested and compared to testosterone aromatization. Enzymatic activities were assessed by tritiated water release from labelled estradiol and testosterone. Kinetic analysis of estradiol 2-hydroxylation showed an apparent K(m) of 23 microM and a V(ma...
Evans DL, Golland LC.The aim of this study was to investigate correlations between lactate concentrations in equine whole blood and plasma measured with Accusport1 and Yellow Springs Instruments (YSI2) (2300) methods. The effect of packed cell volume (PCV) on the accuracy of Accusport was also investigated. Blood samples were collected from Thoroughbred horses at 5-10 min intervals after a treadmill exercise test. Blood was added to NaEDTA (for PCV measurement) and to 2 tubes containing lithium heparin anticoagulant (for lactate assays). At concentrations greater than 10 mmol/l, Accusport1 greatly underestimated t...
Wijesundera WS, Chandrasekharan NV, Karunanayake EH, Dharmasena SP.Two repetitive sequences (IpSdM and IpSdS) have been cloned and sequenced from the genome of Setaria digitata. When IpSdM (214 bp) and IpSdS (201 bp) were aligned, a high degree of homology (85%) was observed, indicating that they belong to the same family of repeats. IpSdM represents a complete repeating element while IpSdS consists of two partial repeating elements arranged in tandem. The elements are present in about 10 000 copies comprising 2.8% of the S. digitata genome. As a diagnostic probe IpSdM detects as little as 100 pg DNA of both S. digitata and S. labiato-papillosa. It can also d...
Kawcak CE, Trotter GW, Frisbie DD, McIlwraith CW.To evaluate the effects of a commercially defined, serum-free medium additive on equine articular cartilage explants, compared with effects of serum-free and serum-supplemented media. Methods: Articular cartilage from a 3-year-old, mixed breed horse euthanatized for reasons other than musculoskeletal disease or sepsis. Methods: Media were changed every 48 hours, and the glycosaminoglycan (GAG) content was determined in media collected at each time point. Glycosaminoglycan synthesis by explant chondrocytes, and residual GAG content of articular cartilage (as a measure of explant GAG loss) were ...
Engvall EO, Pettersson B, Persson M, Artursson K, Johansson KE.A PCR-based assay was developed for detecting DNA of granulocytic ehrlichiae in blood samples from dogs, horses, and cattle, Primers were designed from 16S rRNA sequence information to specifically amplify DNA from a newly identified Swedish Ehrlichia species. The 16S rRNA nucleotide sequence of this Swedish species differs in only two and three positions from the sequences of Ehrlichia phagocytophila and Ehrlichia equi, respectively, which were also amplified by this PCR system. For evaluation, PCR results were compared with microscopic examination of stained blood smears for the detection of...
Netherwood T, Chanter N, Mumford JA.There have been several case reports of foal diarrhoea associated with Clostridium perfringens. However, there has been no epidemiological assessment of the strength of the association of these bacteria with foal diarrhoea or of their relative importance. To prepare methods for such a study, the success of different cultural techniques for the isolation of C perfringens was examined with respect to the various physiological states of the bacteria. The germination and growth of C perfringens NCTC 8239 endospores of differing maturity were favoured by different pre-treatments which failed to rec...
Yang X, Chasteen ND.Electron paramagnetic resonance spectroscopy and gel permeation chromatography were employed to study the molecular diffusion of a number of small nitroxide spin probes (approximately 7-9 A diameter) into the central cavity of the iron-storage protein ferritin. Charge and polarity of these radicals play a critical role in the diffusion process. The negatively charged radical 4-carboxy-2,2,6,6-tetramethylpiperidine-N-oxyl (4-carboxy-TEMPO) does not penetrate the cavity whereas the positively charged 4-amino-TEMPO and 3-(aminomethyl)-proxyl radical and polar 4-hydroxy-TEMPO radical do. Unlike th...
Gravance CG, Liu IK, Davis RO, Hughes JP, Casey PJ.The heads of stallion spermatozoa were analysed by computer automated sperm head morphometry and the morphometric values of the major subpopulations of sperm heads were assessed. The criteria for normal dimensions of stallion sperm heads are proposed based on the analysis of these measurements. Semen samples were collected from 10 fertile and 10 subfertile stallions, processed by a standard method, smeared onto microscope slides and stained using haematoxylin. At least 200 properly digitized sperm heads were analysed from each stallion. The measurements for length, width, area, perimeter and w...
Gustafson MB, Martin RB, Gibson V, Storms DH, Stover SM, Gibeling J, Griffin L.This work determined whether mineral dissolution due to prolonged testing or storage of bone specimens in normal saline would alter their elastic modulus. In one experiment, small pieces of equine third metacarpal bone were soaked in normal saline supplemented with varying amounts of CaCl2. Changing Ca ion concentrations in the bath were monitored and the equilibrium concentration was determined. In a second experiment, the elastic moduli of twenty 4 x 10 x 100 mm equine third metacarpal beams were determined non-destructively in four-point bending. Half the beams were then soaked for 10 days ...
Jackson B, Eastell R, Russell RG, Lanyon LE, Price JS.For many years total alkaline phosphatase (AP) activity in serum has been used to monitor bone metabolism in different species. However, total AP lacks bone specificity because the total activity in serum is made up of several isoenzymes, of which the liver and bone isoforms predominate. The aim of the present study was to evaluate an immunoradiometric assay for measuring bone specific alkaline phosphatase (BAP) in horses. BAP, a specific marker of bone formation, was measured in sera from thoroughbred horses by using a previously characterised wheat germ lectin (WGL) precipitation assay and a...
Frazer GS, Bucci DM.The aims of this project were to document the protein profile of equine seminal plasma and determine the variability between stallions in the relative composition of proteins in the ejaculate. A single ejaculate was obtained from 14 stallions of varying breed and age. The gel fraction was removed by an in-line filter. The semen was centrifuged and the supernatant seminal plasma aspirated without disturbing the sperm pellet. The seminal plasma was recentrifuged and stored in cryovials at -70 degrees C. Samples were thawed, recentrifuged, assayed for protein concentration (BCA protein assay), di...
Lunn DP, Schram BR, Vagnoni KE, Schobert CS, Horohov DW, Ginther OJ.Lymphokine activated killing (LAK) is an example of natural cytotoxicity, and as such is a critical means of defense against diseases such as viral infection and neoplasia. Despite this important role, the specific molecular interactions involved in LAK or other forms of natural cytotoxicity are only partially understood. In some species, cells capable of mediating natural cytotoxicity express the CD8 molecule, although no specific role has been demonstrated for CD8 in non-MHC restricted cytotoxicity. In this study the role of the EqCD8 equine homolog of CD8 in LAK cell activity was examined. ...
Johnsen , Thanh DB, Ly Q, Smestad Paulsen B, Wold JK.IgE-binding components in an extract of horse dander were analyzed, especially with regard to the glycoprotein allergens. After SDS-PAGE under reducing conditions and blotting, several of the glycoprotein IgE-binding components, including two distinct bands of 27 and 31 kDa, were detected. Together with several other bands, they were shown to bind to the lectins Sambucus nigra agglutinin (SNA) and Datura stramonium agglutinin (DSA), indicating terminal sialic acid linked alpha 2 --> 6 to galactose, and galactose linked beta 1 --> 4 to N-acetylglucosamine, respectively. Carbohydrate analy...
Siles-Lucas M, Cuesta-Bandera C.A comparison was made, by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), of excretory/secretory (ES)-crude and immunopurified (with the corresponding anti-host serum) hydatid fluids-and somatic (S)-protoscoleces-proteins, from several ovine, equine, swine, bovine and human Echinococcus granulosus Spanish isolates. Likewise, the host influence on parasitic ES protein expression was studied, comparing purified hydatid fluids from ovine and equine cysts obtained from natural hosts and in RNMI mice. Purified hydatid fluids patterns, under reducing conditions, yielded the mos...
Nett TM, Holtan DW, Estergreen VL.Levels of oestrone, equilin and equilenin (E1), oestradiol (E2) LH, PMSG and prolactin were measured by radioimmunoassay in serum from pregnant mares. Levels of E1 were always greater than those of E2. Both E1 and E2 remained at low levels until Day 80, increased significantly (P less than 0-05) by Day 120 to reach peak levels at Day 210 or 240 and then declined until parturition. Maximum levels of oestrogens observed in this study were 828 +/- 151 pg/ml for E1 and 71 +/- 18 pg/ml for E2 at Days 210 and 240 respectively. Spikes of LH release were observed in early pregnancy in most mares. Leve...
Theurillat R, Larenza MP, Feige K, Bettschart-Wolfensberger R, Thormann W.Ketamine and norketamine are being transported across the blood brain barrier and are also entering from blood into cerebrospinal fluid (CSF). Enantioselective distributions of these compounds in brain and CSF have never been determined. The enantioselective CE based assay previously developed for equine plasma was adapted to the analysis of these compounds in equine brain via use of an acidic pre-extraction of interferences prior to liquid/liquid extraction at alkaline pH. CSF can be treated as plasma. With 100 mg of brain tissue and 0.5 mL of CSF or plasma, assay conditions for up to 30 nmol...
Farlin ME, Jasko DJ, Graham JK, Squires EL.The use of fluorescein-conjugated Pisum sativum agglutinin (FITC-PSA) was evaluated for its ability to distinguish acrosome-intact from acrosome-damaged stallion spermatozoa. Incubation of fresh (acrosome-intact) and frozen-thawed (acrosome-damaged) spermatozoa with FITC-PSA resulted in acrosome-intact spermatozoa that exhibited no fluorescence, while acrosome-damaged spermatozoa exhibited fluorescent staining over the rostral portion of the head and equatorial segment. Experiments using mixtures of various ratios of acrosome-intact and acrosome-damaged spermatozoa determined the precision (in...
Pemberton AD, Hodgson JC, Gilmour JS, Doxey DL.Isolates were prepared from the sera of 12 horses with acute grass sickness, using methods reported to yield serum fractions associated with neurotoxicity, and their components identified by liquid chromatography and spectroscopy. All isolates were found to contain cortisol and six isolates also contained a degradation product of an analgesic drug, dipyrone. However, no recognised neurotoxin was detected.
Hubenov H, Bakalov D, Krastev S, Yanev S, Haritova A, Lashev L.The objective of the study was to evaluate the pharmacokinetics of tobramycin in plasma and urine in the horse (n = 7) after intravenous administration of a dose of 4 mg/kg b.w. Plasma tobramycin concentrations were assayed microbiologically and by means of HPLC analyses. Pharmacokinetic parameters, calculated on the basis of concentrations determined with the microbiological assay were not statistically different from those obtained when data from HPLC analysis were used, but the microbiological assay was more sensitive in the detection of low plasma and urine values. The values of the total ...
Watson ED.Uterine washings were found to promote neutrophil mediated killing of Streptococcus zooepidemicus. Depletion of complement and/or specific antibody from the washings significantly reduced bactericidal activity. Phagocytosis of yeast by uterine washings was complement dependent. Inhibition of the classical pathway significantly reduced opsonic activity indicating that, in addition to direct activation via the alternate pathway, antibody may also be involved in yeast phagocytosis.
Hiss PH, Atkinson JP.THE RESULTS OF THE FOREGOING EXPERIMENTS MAY BE BRIEFLY SUMMARIZED AS FOLLOWS: The amount of antitoxic substance obtained by precipitation with magnesium sulphate from the blood-serum of the horse corresponds, as nearly as can be determined by the use of test guinea-pigs, in full to the protective power of the serum from which it is obtained, i. e. the precipitate from 1 cc. of serum will protect against the same amount of toxin as 1 cc. of the serum itself. Equal amounts of the precipitates by magnesium sulphate from immunized and non-immunized horses act differently toward toxin; i. e. the p...
Teixeira-Neto FJ, McDonell WN, Black WD, Harris W, Grovum L.This study investigated the effects of a muscarinic type 1 (M(1)), 2 (M(2)), and 3 (M(3)) antagonists (4-DAMP, pirenzepine, and methoctramine, respectively) on acetylcholine (Ach)-induced contractions of longitudinal jejunal muscle strips of horses. Strips were irrigated with Krebs-Henseleit solution gassed with 95% O(2) and 5% CO(2), and the developed tension in response to Ach was recorded before and after incubation with increasing concentrations of 4-DAMP (10(-8)-10(-6) M), pirenzepine (10(-6)-10(-4) M), and methoctramine (10(-5)-10(-3) M). When competitive antagonism was characterized, th...
Kettler MK, Weil MR, Perryman LE.Serum uric acid concentrations were determined in horses known to be carriers of combined immunodeficiency gene(s) and in presumed noncarrier horses. Uric acid concentrations were significantly higher (P less than 0.005) in carrier horses than in presumed noncarrier horses. However, there was some overlap in serum uric acid concentrations between carrier and presumed noncarrier horses.
Hoffmann WE, Dorner JL, Morris H.Two isoenzymes of alkaline phosphatase from horse kidney were identified by cellulose acetate electrophoresis. Horse kidney alkaline phosphatase was similar to horse intestinal alkaline phosphatase, in regard to both antigenicity and response to levamisole inhibition, but different from horse liver alkaline phosphatase. This study suggests that horse kidney alkaline phosphatase is an expression of the intestinal gene locus and not the hepatic gene locus.