In vitro research involving horses refers to the study of equine cells, tissues, or biological molecules outside their normal biological context, typically in controlled laboratory environments. This research approach allows scientists to investigate cellular processes, molecular interactions, and the effects of various treatments without the ethical and logistical complexities of in vivo studies. In vitro studies contribute to understanding equine physiology, pathology, and pharmacology by providing insights into cellular responses to pathogens, drugs, and other stimuli. This page compiles peer-reviewed research studies and scholarly articles that explore various in vitro methodologies and their applications in equine science, including cell culture techniques, molecular assays, and drug efficacy testing.
Orrego A, Issel CJ, Montelaro RC, Adams WV.Five serial passages of a cell-adapted strain of equine infectious anemia (EIA) virus were conducted in Shetland ponies. The 13 recipient ponies became agar-gel immunodiffusion test-positive by 25 days after they were inoculated. The virulence of the cell-adapted strain of EIA virus markedly increased through 3 serial passages, although individual variation within passages was high. The 1st serial-passage recipient remained afebrile through 200 days, whereas a febrile episode occurred about every 185, 44, 35, and 33 days in the 2nd, 3rd, 4th, and 5th serial-passage recipients, respectively. Se...
Tuthill RJ, Clark WH, Levene A.A unique pigmented lesion, judged to be a hamartoma of neural crest origin, occurring in a female patient, is compared with equine melanotic disease, The characteristic perifollicular arrangement of pigment-laden spindle cells is remarkably similar in both. Previously described patch- and plaque-like blue nevi in humans are also closely related. Light and ultrastructural features showed differentiation toward both nevus cells and Schwann cells, and it is proposed that the lesion be termed pilar neurocristic hamartoma.
Miller RI, Campbell RS.One in vivo and 2 in vitro tests were developed to study immunological aspects of phycomycosis in clinically infected, recovered and normal in-contact horses. Serum from all infected horses gave positive readings in an agar-gel double diffusion test; serum from normal and recovered horses did not react. A complement fixation test detected antibody against Hyphomyces destruens in 82% clinical cases at an average titre of 20. Serum from recovered and in-contact horses reacted sporadically at positive titre. An intradermal hypersensitivity test (Heaf test) was used to detect evidence of cellular ...
Arriola J, Foote RH.Because microfloral content of stallion semen tends to be high, and strains may be resistant to commonly used antibiotics, amikacin was tested with stallion semen and compared with bull semen. Nine ejaculates to stallion semen were incubated at 37 C in egg yolk-tris extender for 0, 2, 4, 6, 8 and 10 h in the presence of amikacin concentrations of 0, 50, 100, 250, 500, 1,000 and 10,000 microgram/ml, with penicillin and penicillin-streptomycin as controls. Averaged over all incubations, spermatozoal motility was 44, 48, 49, 46, 45, 45 and 19%, for increasing concentrations of amikacin, compared ...
Cross AR, Higson FK, Jones OT, Harper AM, Segal AW.1. The absorption coefficient of human neutrophil plasma-membrane reduced-minus-oxidized cytochrome b-245 was determined [delta epsilon (mM; 559-540 nm) = 21.6 cm-1]. 2. Neutrophil polymorphonuclear leucocytes (neutrophils) were prepared from human, ox, horse and pig blood. In each case plasma-membrane fractions were found to contain low-potential cytochrome b. When membranes from horse neutrophils were incubated anaerobically with either NADH or NADPH the cytochrome b became reduced. Prior stimulation of the cells with phorbol myristate acetate did not increase the rate or extent of cytochrom...
Peters GJ, Veerkamp JH.Optimal conditions for stimulation by phytohaemagglutinin (PHA) were established for equine, porcine, ovine and human lymphocytes in MEMS medium. Optimal thymidine concentration was determined for assay of cell transformation. With all species tested horse serum gave highest thymidine incorporation. Homologous serum was not more appropriate for lymphocytes of man, pig and sheep. Optimal stimulation was achieved at 20, 0.5-5, 5, and 10-40 micrograms PHA per 10(6) cells for human, equine, porcine and ovine lymphocytes, respectively.
Sahu SP, Wool S, Breese SS.In uterine or cervical specimens obtained from pony mares infected with streptomycin-resistant contagious equine metritis bacteria, several colonies of the bacteria which differed in morphologic characteristics were recognized during their primary isolation on Eugon chocolate agar and tryptose chocolate agar plates. The differences were usually not observed until plates were incubated 10 to 15 days. On Eugon chocolate agar plates, smooth colony, sandy colony with rings, and colony with blebs were recognized. On tryptose chocolate agar plates, only a round smooth convex colony was observed. By ...
Cheevers WP, Roberson SM, Brassfield AL, Davis WC, Crawford TB.A virus with the morphologic and biochemical properties of the family Retroviridae has been isolated from cultured cells explanted from a malignant tumor induced by intradermal inoculation of equine sarcoid cells into a combined immunodeficient Arabian foal. By electron microscopy, intracytoplasmic, extracellular, and budding particles measuring 89 to 120 nm with electron-lucent cores were seen. Virus purified from the medium of cultured cells had a buoyant density of 1.15 g/cm3 in isopycnic sucrose-gradient centrifugation, incorporated radiolabeled uridine but not thymidine, and had constitut...
Martin DH, Dietz WH, Alvaerez O, Johnson KM.One hundred and fifty-eight strains of Venezuelan equine encephalomyelitis virus were typed antigenically and classified epidemiologically as either epizootic or enzootic. Plaque sizes for 148 of these strains were determined, and the pH requirements for hemagglutination (HA) of goose erythrocytes of 131 were studied. Only antigenic variant group IABC strains could be classified epidemiologically as epizootic. In vitro these strains were characterized by the formation of small plaques in Vero cells and a relatively narrow pH range for optimum HA reactivity. Experimental studies in horses confi...
Bártek J, Viklický V, Franĕk F, Angelisová P, Dráber P, Jarosíková T, Nĕmec M, Verlová H.Five stable hybridoma lines were prepared using the myeloma cell line P3-X63-Ag.653 and spleen cells of mice hyperimmunized by pig transferrin. All hybridomas grew well in mouse peritoneal cavity and produced antibodies of the IgG1 subclass. Antibody preparations obtained from ascitic fluids tested for their capacity of antigen precipitation. No precipitation was obtained with single antibodies and with pairs of antibodies. Three out of 10 possible triads gave clear and sharp precipitation zones and rings in immunodiffusion tests performed in agar gel. All 5 antibodies were shown by quantitati...
Lindmark DG, Jarroll EL, Timoney PJ, Shin SJ.The energy metabolism of the English E-CMO strain of contagious equine metritis bacterium was studied in whole cells and cell extracts. This bacterium appears to have an active Krebs cycle and probably obtains energy by oxidative phosphorylation since glycolysis and the hexose monophosphate pathways appear to be absent. These conclusions are based on the findings that [U-14C]glucose incorporation by this bacterium is below the level of detection, and that respiration is stimulated by Krebs cycle intermediates (i.e., malate, citrate, and succinate), but not by glucose, fructose, maltose, or suc...
Jagodzinski PW, Funk GF, Peticolas WL.The nature of the binding of aromatic aldehyde and aromatic alcohol substrates to the catalytic zinc of equine liver alcohol dehydrogenase has been studied by using resonance-enhanced Raman spectroscopy. When an excess of both enzyme and coenzyme to substrate is used, a stable ternary chemical intermediate is formed between liver alcohol dehydrogenase and the reduced coenzyme, nicotinamide adenine dinucleotide, and the aldehyde, p-(dimethylamino)benzaldehyde, in the pH range 8.5-0.6. Resonance-enhanced Raman spectra clearly show that this same intermediate is formed between the excess enzyme, ...
Brems DN, Liu YC, Stellwagen E.The heme iron of horse heart cytochrome c was selectively removed using anhydrous HF. The product, porphyrin c, exhibits the viscosity, far ultraviolet circular dichroic, and fluorescence properties characteristic for native cytochrome c. However, porphyrin c is more susceptible to denaturation by guanidine hydrochloride and by heat than is the parent cytochrome. All of the conformational parameters of porphyrin c exhibit a common reversible transition centered at 0.95 m guanidine hydrochloride at 23 degrees C and pH 7.0. Guanidine denatured porphyrin c refolds in two kinetic phases having tim...
Pierrot M, Astier JP, Astier M, Charles M, Drenth J.A detailed study of the crystallization of hog and horse colipases has been undertaken. Several crystallographic varieties have been obtained and a 0.3-nm resolution structure determination is actually in progress. The sequence of the A form of horse colipase (one methionine) is given. From spectrophotometric experiments and sequence comparisons, the involvement of the aromatic residue in position 52 in the micelle binding site has been demonstrated.
Shively MA, Banks KL, Greenlee A, Klevjer-Anderson P.Equine infectious anemia is a chronic disease of horses caused by a nononcogenic retrovirus. Studies were undertaken to determine the types of cells involved in the in vitro lymphoproliferative response to viral antigens and the dynamics of this reaction. It was observed that reactive lymphocytes were present at unpredictable times in the peripheral blood of infected horses. This reaction was shown to be specific for the interaction of equine infectious anemia virus and T lymphocytes. Enriched B-lymphocyte populations did not divide when exposed to equine infectious anemia virus. Macrophages w...
Sellers AF, Lowe JE, Drost CJ, Rendano VT, Georgi JR, Roberts MC.The circular and longitudinal muscle coats of equine "midcolon" were found to be directly electrically coupled. They appear to act in concert, in healthy animals, as a pacemaker in the area of the large colon pelvic flexure, for retropulsive-propulsive myoelectrical events. The retropulsive events keep the cecum and right ventral and left ventral divisions of the colon filled, imposing a delay time for fermentation of cellulose and for bacterial protein synthesis. Point-to-point involvement of adjacent colon sections was slowed by cooling the intestinal contents with no adverse clinical signs....
Camp CJ, Leid RW.A method for the isolation of equine neutrophils was developed using metrizamide cushions. A purity of greater than 95% was routinely obtained with greater than 90% viability. These cells were radiolabeled and tested for their chemotactic response in Boyden chambers to zymosan-activated equine serum, the partially purified equine complement component C5a, and formyl-L-methionyl-L-leucyl-L-phenylalanine. The time and ionic requirements for chemotaxis of radiolabeled equine neutrophils were investigated and maximal movement was observed at 2 hours' incubation and 1.0 mM Ca and 0.5 mM Mg. Dinitro...
Jörg A, Pasquier JM, Klebanoff SJ.Eosinophil peroxidase (donor: hydrogen-peroxidase oxidoreductase, EC 1.11.1.7) was isolated in a highly purified form (415/280 nm ratio, 1.05) from horse peripheral blood eosinophil. Eosinophil peroxidase was extracted from intact eosinophils (98-100% purity) or isolated eosinophil granules with 0.05 M acetate buffer (pH 4.7)/0.18 M NaCl and purified by chromatography on Sephadex G-200 and carboxymethylcellulose. Final elution was with 0.05 M acetate buffer (pH 4.7)/ 1 M NaCl. Horse eosinophil peroxidase is a strongly basic protein with bacterial properties when combined with H2O2 and iodide, ...
Jörg A, Henderson WR, Murphy RC, Klebanoff SJ.Horse eosinophils purified to greater than 98% generated slow reacting substance (SRS) when incubated with the calcium ionophore A23187. On a per cell basis, eosinophils generated four to five times the SRS produced by similarly treated horse neutrophils. Eosinophil SRS production was inhibited by 5,8,11,14-eicosatetraynoic acid and augmented by indomethacin and arachidonic acid, suggesting that it was a product(s) of the lipoxygenase pathway of arachidonic acid metabolism. Compounds with SRS activity were purified by high-pressure liquid chromatography (HPLC) and identified by ultraviolet spe...
Liu IK, Shivers CA.Cross-reactivity tests indicated that the equine zona pellucida shares common antigen(s) with porcine zona. Porcine oocytes were therefore used to test for the presence of zona antibodies in the sera of horses. Serum samples were collected from 65 mares infertile for unexplained causes: 7 mares were strongly positive for antibodies reactive to porcine zona pellucida as determined by an indirect immunofluorescence method. Of these 7 mares, aged 8-23 years, 2 were nulliparous and 5 were multiparous. Zona-covered horse oocytes were treated with sera from 4 mares previously identified as zona posi...
Riemersa DJ, Schamhardt HC.A clamp designed for holding tendons in force/elongation studies is described. No slippage occurred when tensile forces up to 13,800 N were applied to horses digital flexor tendons fixed in this clamp.
Bridges CG, Edington N.Equine sera were used to immunoprecipitate radiolabelled virus-infected cell proteins; subsequent resolution with polyacrylamide gel electrophoresis identified the EHV-1 polypeptides VP 2, 10a, 11, 13, 14, 15, 16, 20, 21 and 23a. The humoral support of ADCC by these sera was examined in vitro. Cytotoxicity could be demonstrated against both subtypes irrespective of the immunising isolate. The implications of these results are discussed.
Serafini R, Ghosh S, Love CC, Medrano JMR, Teague SR, LaCaze KA, Varner DD.Commercially available vaginal lubricants, typically labeled as non-spermicidal, are used to lubricate equine artificial vaginas prior to semen collection. Improper type or amount of lubricant might affect stallion sperm quality, either after short-time exposure or following cooled storage of extended semen previously exposed to lubricant. The aim of this study was to evaluate stallion sperm quality following exposure to lubricant-containing extender for 1 h (T1h) or 24 h (T24h). Three ejaculates were collected from each of four stallions using a small volume of petrolatum to lubricate a...
Minelli A, Moroni M, Trinari D, Mezzasoma I.Ectoenzymic activities capable of hydrolyzing ATP sequentially to adenosine are present on equine epidydimal spermatozoa membranes. Kinetic parameters for ATPase, ADPase and 5'-nucleotidase were obtained by analysis of progress reactions curve when ATP, ADP and AMP were supplied as initial substrates. These values are not different from those found when the substrates were supplied from the preceding reactions. Feed-forward inhibition on 5'-nucleotidase by ATP/ADP was taken into account to fit simulated data to the experimental results. None of the substrates supplied by the preceding reaction...
Mogielnicka-Brzozowska M, Woźniak MJ, Cichowska AW, Fraser L, Kraziński B, Strzezek R, Zielińska D.Seminal plasma (SP) proteins are responsible for sperm functional quality. Developing a reliable method to determine the degree of oxidative damage of these proteins is important for establishing semen fertilizing ability. The main aim of the study was to verify the applicability of protein carbonyl derivatives measurement in the SP of canine and stallion, using a method with 2,4-dinitrophenylhydrazine (DNPH). The research material consisted of ejaculates obtained from eight English Springer Spaniels, and from seven half-blood stallions during the breeding and non-breeding season. The content ...
Inoue OJ, Freeman DE, Wallig M.To study effects of hypochlorous acid (HOCl) on equine colonic mucosa in vitro, and determine whether addition of ascorbic acid protects against the effects. Methods: 6 healthy horses and ponies. Methods: Short-circuit current was measured in mucosa mounted in Ussing chambers. Incubation conditions were: control (no additions); 5 mM HOCl; 1 mM HOCl; same and 5 mM ascorbic acid; 3 mM HOCl; 3 mM HOCl and 5 mM ascorbic acid; 7 mM HOCl; and 7 mM HOCl plus 5 mM ascorbic acid. Permeability was measured with [3H]mannitol and, at the conclusion of each experiment, tissues were examined microscopically...
Woods AC, Chesney AM.A filterable agent has been obtained from the humors and tissues of the eyes of horses suffering from active periodic ophthalmia. The intra-vitreous injection of this filtrate produced in normal horses the same clinical and pathological picture observed in the natural disease. This filtrate injected into rabbits produced a different clinical picture, but the essential pathological lesions closely resembled those found in horses. After passage of the filterable agent through six generations of rabbits, it again produced the clinical and pathological picture of the natural disease when injected ...
Joonè CJ, Schulman ML, Fosgate GT, Plagis TA, Crafford JE, Gupta SK, Bertschinger HJ.Few studies have investigated the cell mediated immune response during zona pellucida-based immunocontraception, despite hypothesized cytotoxic T-cell involvement in ovarian dysfunction associated with these vaccines. This study aimed to investigate antigen-specific anamnestic responses of helper (CD4) and cytotoxic (CD8) T-lymphocytes in peripheral blood mononuclear cells (PBMC) isolated from pony mares before and after their treatment with native porcine zona pellucida (pZP), recombinant pZP3 and pZP4 antigens (reZP) or adjuvanted saline. Mares were randomly assigned to pZP, reZP and control...
Gastal GDA, Scarlet D, Melchert M, Ertl R, Aurich C.In embryos subjected to assisted reproductive techniques, epigenetic modifications may occur that can influence embryonic development and the establishment of pregnancy. In horses, the storage temperature during transport of fresh embryos before transfer is a major concern. The aim of this study was, therefore, to determine the effects of two storage temperatures (5 °C and 20 °C) on equine embryos, collected at day seven after ovulation and stored for 24 h, on: (i) morphological development; (ii) expression of candidate genes associated with embryo growth and development, maternal recognitio...
Knych HK, Finno CJ, Baden R, Arthur RM, McKemie DS.The in vivo metabolism and pharmacokinetics of flunixin meglumine and phenylbutazone have been extensively characterized; however, there are no published reports describing the in vitro metabolism, specifically the enzymes responsible for the biotransformation of these compounds in horses. Due to their widespread use and, therefore, increased potential for drug-drug interactions and widespread differences in drug disposition, this study aims to build on the limited current knowledge regarding P450-mediated metabolism in horses. Drugs were incubated with equine liver microsomes and a panel of r...
Morris DD, Crowe N, Moore JN.The purpose of this study was to determine if a structurally novel dual inhibitor of arachidonic acid metabolism, SK & F 86002, would inhibit the endotoxin-induced production of tumor necrosis factor (TNF) activity by equine peritoneal macrophages. Equine peritoneal macrophages were variously pretreated for 0, 0.5 and 2 h with SK & F 86002 at 10(-9) to 10(-4) molar final concentrations or were left untreated. Then, the macrophages were cultured in vitro in the presence of endotoxin (5 ng/mL). Supernatant media were collected after 4 h and stored at -70 degrees C until assayed for TNF a...
Whan G, Phillips J, Bullock S, Runciman RJ, Pearce S, Hurtig M.A novel, multi-use, low-stiffness and low-cost transducer for measuring in vitro strains has been developed and tested. Currently available strain measurement methods are either too expensive, too complicated or too inflexible for multi-use strain measurement. The stainless-steel modular strain measurement clip introduced here was instrumented with four 350 Omega axial strain gauges in a full Wheatstone bridge configuration to take advantage of commonly available strain gauge amplifier equipment. Adjustable extension arms were designed to allow greater application versatility. The clip was cal...
We evaluated the vasorelaxant effect of propentofylline (PPF), a methylxanthine derivative, and its mechanism of action in equine digital veins (EDVs). Cumulative concentration-response curves to PPF (1 nM-300 µM) were recorded in phenylephrine-precontracted EDV rings under different experimental conditions. PPF-induced relaxation was partially inhibited by endothelium removal, but was unaltered by CGS-15943 (an adenosine receptor antagonist; 3 µM). PPF-induced relaxation was partially inhibited in the presence of L-NAME (a nitric oxide (NO) synthase inhibitor; 100 µM), ODQ (an inhibitor of...
Coyne CP, Smith JE, DeBowes RM.Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, XIIIa*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate. Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency),...
Kot K, Tischner M.The aim of the experiment was to determine the effect of a year-to-year prolonged daylength on the patterns of equine reproductive activity and results of embryo recovery. Experiments using Konik Polski mares were conducted over four reproduction seasons. Five mares were exposed to a regimen of artificially prolonged daylength (APD) and another five mares in a control group were kept under conditions of natural daylight. Both the control and experimental groups were examined for appearance of estrus, ovulation and also for the state of their coats. A single stallion was used for breeding all o...
Alexander S, Irvine CH.Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Brom-de-Luna JG, Salgado RM, Felix MR, Canesin HS, Stefanovski D, Diaw M, Hinrichs K.In vitro production of horse embryos via intracytoplasmic sperm injection (ICSI) is a useful clinical and research technique. Current rates of blastocyst production are typically sub-optimal, and few methods to increase the rate of equine blastocyst development have been reported. Factors that might improve blastocyst production in a horse embryo culture system were explored. Myo-inositol is found in the horse oviduct and improves blastocyst development in other species, thus Experiment 1 was conducted to assess the effect of 10 mM myo-inositol added to Day 0-5 embryo culture medium, using hor...
Yagisawa S.One mole of horse hemoglobin tetramer reacts with 2 moles of 2-chloromercuri-4-nitrophenol (MNP) at beta 93 cysteine. The difference spectra between NMP-bound hemoglobin and hemoglobin, measured with the aid of ascorbic acid and ascorate oxidase [EC 1.10.3.3] as deoxygenation reagents, indicate that the pK of the phenolic hydroxyl group of MNP increases by 0.6 to 0.8 pH unit on deoxygenation of the hemoglobin. The Hill constant of the modified hemoglobin changes with pH. It decreases from about 2.4 at pH 6.8 to about 1.0 at pH 9.0 This effect of the reagent is interpreted as inherent to the re...
Yoshimura T, Sogabe T, Aki K.Electron transfer between horse heart and Candida krusei cytochromes c in the free and phosvitin-bound states was examined by difference spectrum and stopped-flow methods. The difference spectra in the wavelength range of 540-560 nm demonstrated that electrons are exchangeable between the cytochromes c of the two species. The equilibrium constants of the electron transfer reaction for the free and phosvitin-bound forms, estimated from these difference spectra, were close to unity at 20 degrees C in 20 mM Tris-HCl buffer (pH 7.4). The electron transfer rate for free cytochrome c was (2-3).10(4)...
Landim-Alvarenga FC, Alvarenga MA, Seidel GE, Squires EL, Graham JK.Experiments evaluated the ability of follicular fluid (FF), dilauroylphosphatidylcholine (PC12) and the calcium ionophore A23187 (A23187) to induce capacitation in stallion and bull spermatozoa, determined by the ability of the spermatozoa to penetrate zona-free hamster, bovine and equine oocytes. Spermatozoa suspensions were incubated at 37 degrees C in one of the following treatments: 1) a modified Tyrode's medium (BGM3) alone; 2) BGM3 + FF; 3) BGM3 + PC12; 4) BGM3 + FF + PC12; 5) BGM3 + A23187; and 6) BGM3 + FF + A23187. Treated spermatozoa were incubated with zona-free hamster, bovine and ...
Sod GA, Riggs LM, Mitchell CF, Martin GS, Gill MS.To compare number of cycles to failure for palmarodorsal 4-point bending of a modified 5.5 mm broad locking compression plate (M5.5-LCP) fixation with a 5.5 mm broad LCP (5.5-LCP) fixation used to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing. Methods: Adult equine cadaveric MC3 bones (n=6 pairs). Methods: An 8-hole, M5.5-LCP, obtained by having a 1.0 mm thickness removed from the bone contact portion of the 5.5-LCP, was applied to the dorsal surface of 1 randomly selected MC3 from each pair, and an 8-hole, 5.5-LCP was applied dorsally to the ...
Orsolini MF, Meyers SA, Dini P.As the use of assisted reproductive technologies (ART) and in vitro embryo production (IVP) expand in the equine industry, it has become necessary to further our understanding of available semen selection techniques. This segment of our two-section review will focus on the selection of spermatozoa based on quality and sex for equine intracytoplasmic sperm injection (ICSI), as well as current and future developments in sperm sorting technologies. Ultimately, novel methods of semen selection will be assessed based on their efficacy in other species and their relevance and future application towa...
Bhutia WD, Gupta S, Rani R, Batra K, Sethi K, Kumar S, Kumar R.Trypanosoma evansi is a causative agent of chronic wasting and fatal disease of livestock and wild animals known as surra. In this study, repurposing approach based on drug target was used to investigate the efficacy of kinase inhibitors (Barasertib-HQPA, BAR and Palbociclib isethionate, PAL) and protease inhibitors (Z-pro-prolinal, Z-PRO and Leupeptin hemisulphate, LEU) against T. evansi in HMI-9 medium. BAR, PAL and Z-PRO exhibited IC values of 13.52 µM, 0.6375 µM and 63.20 µM against T. evansi in terms of growth inhibition, in the contrary, LEU failed to exhibit a significant growth i...
Cunha AP, Bello AC, Leite RC, Ribeiro AC, Freitas CM, Bastianetto E, Oliveira PR.The objective of this study was to evaluate the effect of the Amblyomma cajennense strategic control program on the Anocentor nitens population. The acaricide treatments were carried out every seven days and divided in two series, the first one beginning in April 2004 (eight treatments) and the second beginning in July of the same year (five treatments), using pyrethroid chemical base - cypermethrin in the concentration of 0,015%. Monthly it was evaluated the infestation of A. nitens in the ear and nasal diverticulum of the equines before (October 2003 to March 2004) and after (October of 2004...
Leopold S, Samper JC, Curtis E, Buhr MM.Movement of Ca2+ into spermatozoa is a critically important event for capacitation and the acrosome reaction. In the present study, the nature of Ca2+ movement in fresh equine spermatozoa was established and the effects of oviductal cell conditioned medium (OCM) and cryopreservation on Ca2+ flux were investigated. The ability of fresh and cryopreserved stallion spermatozoa to regulate Ca2+ concentration over time was evaluated in Ca2+ -free PBS. Intracellular Ca2+ concentrations were higher in cryopreserved spermatozoa than in fresh spermatozoa. However, extracellular Ca2+ concentrations were ...
Rakestraw PC, Snyder JR, Sanders KM, Shuttleworth WC.To evaluate electrical activity of jejunal circular muscle in horses and characterize electrical responses to stimulation by intrinsic inhibitory neurons. Methods: Portions of jejunum obtained from horses euthanatized for reasons other than gastrointestinal tract disease. Methods: Isolated circular muscle preparations were perfused with oxygenated modified Krebs solution. Glass microelectrodes were used for intracellular recording of membrane potentials from single smooth muscle cells. Electrical activity and responses to electrical field stimulation (EFS) of intrinsic neurons in the presence ...
Gray AW, Davies ME, Jeffcott LB.We report on preliminary results of a novel in vitro culture system designed to generate equine osteoclasts in large numbers. Osteoclast generation, as determined by the expression of tartrate resistant acid phosphatase (TRAP) and ability to resorb bone, was enhanced in equine bone marrow cultures supplemented with fibroblastic cell (L929) conditioned medium (L929-CM). Bone marrow was collected from a total of 12 horses and ponies and TRAP-positive cells with bone resorbing ability were generated in significant numbers in the last seven. TRAP-positive mononuclear cells appeared after three day...
Sasaki N, Takakuwa J, Yamada H, Mori R.To evaluate effectiveness of allogeneic bone screws and pins for internal fixation of midbody transverse fractures of equine proximal sesamoid bones (PSBs) in vitro. Methods: 14 forelimbs from cadavers of 3-year-old Thoroughbreds. Methods: Allogeneic cortical bone fragments were collected from the limbs of a male Thoroughbred, and cortical bone screws were prepared from the tissue by use of a precision desktop microlathe programmed with the dimensions of a metal cortical bone screw. A midbody transverse osteotomy of each PSB was performed by use of a bone-shaping oscillating saw and repaired v...
Papkoff H, Murthy HM, Roser JF.The tyrosine residues of equine chorionic gonadotropin have been nitrated with tetranitromethane and the resulting effects on the biological and immunological activities of the hormone studied. All of the tyrosine residues in equine chorionic gonadotropin were found to react with tetranitromethane when a 100-fold molar excess of reagent was used or with an 8.6 molar excess in the presence of 5 M guanidine hydrochloride. Complete nitration abolished the biological activities and decreased the immunological activity of the hormone. The nitration of one tyrosine residue resulted in the loss of 70...
Fatemikia H, Kamyab M, Movahed A, Sadeghi M, Kim E, Behdani M, Mohammadpour Dounighi N, Shahrivar M, Seyedian R.In this study, the neutralizing abilities of the equine and the recently introduced camelid antivenoms on the hemodynamic parameters (inotropism, chronotropism, and arrhythmogenicity) were assessed following envenomation by venom in rats. Methods: At first, the electrophoretic profiles of both products were obtained by using the SDS-PAGE method (12.5%) and stained with Coomassie blue and silver nitrate. Secondly, different doses of the camelid antivenom (10, 50, and 100 µl) were given intravenously in 10 min before venom injection (400 µg/rat). The neutralizing potencies of camelid and equi...
Fukushima JG, Cascone O, Santomé JA, Biscoglio de Jimenez Bonino MJ.Reactivity of histidine residues in equine growth hormone to ethoxyformic anhydride was studied. The existence of two kinetically different sets was demonstrated: one of them including only the slow reacting histidine 169 (k = 0.164 min-1) and the other containing fast reacting histidines 19 and 21 (k = 0.892 min-1). A correlation between the decrease in the capacity to compete with 125I-labeled hormone for rat liver binding sites and the degree of ethoxyformylation of the fast group was found. Circular dichroism studies indicated no significant conformational changes in the protein with all t...
