Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:In Vitro Research
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.
Effects of pentoxifylline on equine neutrophil function and flow properties. Pentoxifylline has been reported to improve peripheral vascular circulation by altering the flow properties of blood. To determine if the hemorrheological effects of pentoxifylline were mediated by alterations in neutrophil function and/or flow properties, we evaluated the drug's effects on equine neutrophils in vitro. Pentoxifylline, at a concentration of 1 x 10(-1) M, but not at concentrations of 1 x 10(-6) M to 1 x 10(-2) M, markedly suppressed neutrophil superoxide production, zymosan phagocytosis and adherence to nylon wool. Pentoxifylline failed to improve neutrophil filterability throug...
C3 fixed in vivo to cornea from horses inoculated with Leptospira interrogans. C3 was detected bound in vivo to the opaque cornea of horses inoculated with killed Leptospira interrogans. Employing epithelial corneal cells isolated from a monolayer in tissue culture, we proved that C3 is fixed in vitro to the intact cell surface after incubation with a fresh equine anti-Leptospira serum. These findings, in addition to the infiltration of cornea with neutrophils and lymphocytes, may explain the mechanisms of tissue damage in recurrent uveitis of horses with leptospirosis.
Potential use of simple manganese salts as antioxidant drugs in horses. The scavenging of superoxide radicals by endogenous and therapeutically administered superoxide dismutases may prevent superoxide-mediated oxidative stress leading to lipid peroxidation, membrane lysis, and cell death in a wide variety of normal and pathologic states. Simple inorganic manganous salts such as MnCl2 also have superoxide dismutase-like activity and are extremely inexpensive, compared with enzymatic superoxide dismutase preparations. In this study, we explored the use of Mn salts as antioxidant drugs. We used the percentage of inhibition of nitroblue tetrazolium reduction by super...
Acholeplasma multilocale sp. nov., isolated from a horse and a rabbit. Acholeplasma strains were isolated from the nasopharynx of a horse (strain PN525T [T = type strain]) and the feces of a rabbit (strain B1). One clone of strain PN525T and one clone of strain B1 were examined in detail. These clones were indistinguishable from each other and were serologically distinct from the previously described Acholeplasma and Mycoplasma spp. The strains had the following properties: guanine-plus-cytosine content of 31 mol%; sterol was not required for growth, which occurred under both aerobic and anaerobic conditions; glucose was metabolized; and arginine was hydrolyzed. ...
Involvement of interleukin 2 receptors in conceptus-derived suppression of T and B cell proliferation in horses. The mechanism by which a horse conceptus-derived immunosuppressive factor (HCS) of M(r) > 100,000 inhibits lymphocyte proliferation was investigated. The factor was obtained from the culture supernatants of 20-day-old horse conceptuses; activity, identified by reduced uptake of [3H]thymidine by mitogen-stimulated lymphocytes, was greatest (P < 0.01) in cultures stimulated by mitogen from pokeweed. HCS also suppressed cell proliferation stimulated by phytohaemagglutinin (P 0.05). Data from a fluorescence-activated cell sorter indicated that supplementation with HCS reduced the number of ...
Immunochemical study of equine chorionic gonadotropin (eCG/PMSG): antigenic determinants on alpha- and beta-subunits. In the present study we have established an immunochemical mapping of equine Chorionic Gonadotropin (eCG/PMSG) using three monoclonal antibodies (mAbs), namely the antibodies ECG01, E10 and D7, raised against the native hormone. These antibodies do not bind to reduced, alkylated hormone, suggesting that they recognize discontinuous rather than continuous epitopes. We have also assessed the reactivity of mAbs towards human CG, and ovine, porcine, equine and bovine LH and FSH. The antigenic determinant recognized by ECG01 is localized on the alpha-subunit of equine gonadotropins and of human CG ...
Identification of equine herpesvirus 4 glycoprotein G: a type-specific, secreted glycoprotein. Equine herpesvirus 4 (EHV4) glycoproteins of M(r) 63K and 250K were identified in the supernatant of infected cell cultures. The 63K glycoprotein was type-specific; that is, it reacted with monospecific sera from horses that had been immunized or infected with EHV4, but not with monospecific sera from horses immunized or infected with EHV1, a closely related alphaherpesvirus. It was postulated that the secreted protein may be the homologue of similarly secreted glycoproteins of herpes simplex virus 2 glycoprotein G (HSV2 gG) and pseudorabies virus (PRV) gX, which is the homologue of HSV2 gG. T...
Mechanical properties of suture materials in vitro and after in vivo implantation in horses. Tensile testing of reproducible loops of size 5 braided polyester, size 2 polyglycolic acid, size 2 monofilament nylon, and size 2 polydioxanone sutures was performed in vitro and after subcutaneous implantation in horses for 7, 14, and 28 days. Maximum breaking strength, energy absorption, and percentage elongation to breakage point were measured. Size 5 braided polyester had the highest maximum breaking strength and energy absorption over 28 days. Polydioxanone had better mechanical performance over 28 days than did polyglycolic acid. On day 28, none of these parameters was measurable in pol...
Decreased airway mucosal prostaglandin E2 production during airway obstruction in an animal model of asthma. Heaves is a respiratory disorder of horses and ponies characterized by bouts of acute airway obstruction and airway hyperresponsiveness. We measured prostaglandin E2 (PGE2) and 15-hydroxyeicosatetraenoic acid (15-HETE) production in vitro in tracheal epithelium obtained from six affected horses at the time of acute airway obstruction as compared with six matched control horses. Strips of epithelium and subepithelial tissue were prepared and stimulated with A23187, histamine, and bradykinin. The PGE2 and 15-HETE in media from strips was quantitated by radioimmunoassay. 15-HETE above the limits ...
[Effects of the fraction (1-10 kDa) of the brain of a Yakut horse on kinetic parameters of Ca2+ transport system in sarcolemma vesicles of cardiomyocytes]. The effect of the fraction (1-10 kDa) obtained from the brain of cold-adapted animal (Yakut horse) on Ca2+ transport in sarcolemma vesicles of cardiomyocytes was investigated. It was shown that during insertion of Yakut horse brain fraction into incubation medium at the concentration from 10(-9) M to 3.10(-5) M at Ca2+ transport substrate concentration from 0.1 mM to 1.0 mM, the rate of Ca2+ passive penetration into vesicles slightly increased and at Ca2+ transport substrate concentration 3 mM, which is physiologic, a decrease of rate values was established for all concentrations of the fracti...
Thermal injury by in vitro incision of equine skin with electrosurgery, radiosurgery, and a carbon dioxide laser. Freshly harvested equine skin incised with an electrosurgical unit, a radiosurgical device, or a carbon dioxide (CO2) laser was examined by light microscopy to determine the extent of thermal injury caused by each instrument. There was no significant difference between the thermal injury caused by the electrosurgical unit in the pure-cut mode and the CO2 laser in the superpulse mode, or between the electrosurgical unit and the radiosurgical device in the fully filtered cut mode. However, thermal injury caused by the CO2 laser was significantly less than that caused by the radiosurgical device....
Equine chondrocyte activation by a variety of stimuli. There is increasing evidence that the chondrocyte is capable of considerable anabolic and catabolic activity. In the case of equine chondrocytes, this study demonstrates that a variety of factors involved in the pathogenesis of joint disease stimulate the production of prostaglandin E2. These include exposure to IL-1, bone fragments and LPS. In addition, an IL-1-like factor was shown to be produced by the chondrocyte itself, when stimulated by LPS, providing a possible mechanism for amplification of extra-cartilagenous signals and even autocrine control. Considered together with evidence of in...
World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) methods for the detection of anthelmintic resistance in nematodes of veterinary importance. Methods have been described to assist in the detection of anthelmintic resistance in strongylid nematodes of ruminants, horses and pigs. Two tests are recommended, an in vivo test, the faecal egg count reduction test for use in infected animals, and an in vitro test, the egg hatch test for detection of benzimidazole resistance in nematodes that hatch shortly after embryonation. Anaerobic storage for submission of faecal samples from the field for use in the in vitro test is of value and the procedure is described. The tests should enable comparable data to be obtained in surveys in all parts o...
In vitro production of specific antibody by equine peripheral blood mononuclear cells using tetanus toxoid as a recall antigen. Anti-tetanus toxoid (TT) antibody (Ig) levels in the supernatant of cultured, pre-immunised equine peripheral blood mononuclear cells (PBMC) were measured by an indirect enzyme-linked immunoabsorbent assay (ELISA). Optimal anti-TT Ig production occurred at concentrations of stimulating, purified TT of between 0.001 and 0.1 micrograms ml-1, which varied depending on the cell concentration. Optimal anti-TT Ig production was most consistently produced when the cell concentration was 5 x 10(6) ml-1. At this cell concentration maximal anti-TT Ig was induced using 0.1 micrograms ml-1 TT. At a cell c...
Interaction of plasma gelsolin with tropomyosin. Horse plasma gelsolin labelled with benzophenone-4-isothiocyanate can be photochemically cross-linked to rabbit cardiac tropomyosin. The cross-linking proceeds with greater efficiency in calcium-containing buffers. Further evidence for interaction between these proteins is provided by retention of fluorescently labelled gelsolin on tropomyosin-agarose affinity columns and by the ability of tropomyosin to cause an increase in the fluorescence intensity of gelsolin labelled with fluorescein-5-isothiocyanate. Both of these effects require the presence of calcium ions.
Hydrophobic interaction of lysozyme and alpha-lactalbumin from equine milk whey. From fluorescence measurements on mixtures of bis-ANS and equine lysozyme and from Ca(2+)-dependent hydrophobic interaction chromatography of equine lysozyme, it is demonstrated that Ca2+ binding induces a conformational change upon which hydrophobic regions in the protein become less accessible. Bis-ANS fluorescence titrations in the absence of Ca2+ and in 2 mM Ca2+ are also performed with equine alpha-lactalbumin variants B and C. These variants differ by an amino-acid exchange Asp----Ile at residue 95. The fluorescence titration curves indicate that the accessibility of the probe to the Ca2...
Crystal structure of cleaved equine leucocyte elastase inhibitor determined at 1.95 A resolution. The crystal structure of active-site cleaved equine leucocyte elastase inhibitor, a member of the serpin superfamily, has been solved and refined to a crystallographic R-factor of 17.6% at 1.95 A resolution. Despite being an intracellular inhibitor with rather low sequence homology of 30% to human alpha 1-antichymotrypsin and alpha 1-proteinase inhibitor, the three-dimensional structures are very similar, with deviations only at the sites of insertions and few mobile secondary structure elements. The better resolution in comparison with the structures of other cleaved serpins allows a more pre...
Effect of calcium on the stability of mares’ milk lysozyme. The three aspartic acid residues that form part of the Ca-binding site of mares' milk lysozyme have apparent pK values of 4.9, 4.3 and 4.1. The fluorescence of tryptophan has been used to compare the denaturation of mares' milk lysozyme by guanidinium chloride at various concentrations of Ca with that of hens' egg-white lysozyme (EC 3.2.1.17) and alpha-lactalbumin. Fluorescence revealed an intermediate stage in the denaturation of mares' milk lysozyme. The Ca-free form of mares' milk lysozyme is slightly more stable than that of alpha-lactalbumin, but its interaction with Ca is similar to that...
Endotoxin-induced production of interleukin 6 by equine peritoneal macrophages in vitro. A study was performed to determine whether equine peritoneal macrophages produce interleukin 6 (IL-6) in vitro in response to endotoxin. Peritoneal fluid was collected from 14 clinically normal adult horses and was used as the source of peritoneal macrophages. Macrophages from each horse were isolated and cultured separately in vitro in the absence or presence of various concentrations (0.5, 5, 500 ng/ml) of endotoxin (lipopolysaccharide from Escherichia coli 055:B5). Culture medium supernatants were collected after 3, 6, 12, and 24 hours' incubation and were frozen at -70 C until assayed for ...
Embryo-initiated oviductal transport in mares. The hypothesis that equine embryos initiate oviductal transport in mares was tested by placing day 6 uterine embryos in the oviducts of day 2 (n = 10) or day 5 (n = 10) recipient mares and attempting to collect the embryos from the uterus 48 h later. To determine whether the surgical transfer procedure initiated oviductal transport, medium alone was placed in the oviducts of day 2 (n = 10) inseminated mares (sham transfer), and uterine embryo collections were attempted 48 h later. Embryos were transported through the oviduct of day 2 recipients by day 4 (instead of day 5 to 6) in six of ten ma...
Monitoring of effects induced by recombinant equine interferon-beta 1 in whole blood and separated fractions of peripheral blood of horses. Interferon is known to induce antiviral mechanisms and to exert immunoregulatory capacities on various cell types. The antiviral capacity of recombinant equine interferon-beta 1 (rEqIFN-beta 1) is most sensitively monitored by indirect quantitation of multiplication of vesicular stomatitis virus (VSV) in blood cells of horses. As few as 0.5 pg rEqIFN-beta 1/ml can be assessed by means of 90% reduction of VSV-replication in whole blood (w.b.) as well as in isolated mononuclear blood cells (MNC) in spite of individual variations. The immunoregulatory influence of 20-50 pg rEqIFN-beta 1/ml is suf...
Effects of equine infectious anemia virus on hematopoietic progenitors in vitro. Direct effects of equine infectious anemia virus (EIAV) on hematopoiesis in vitro were studied. Bone marrow mononuclear cells from clinically normal horses were incubated with 100 TCID50 of EIAV/10(7) cells. These cells were cultured to assay for colonies derived from erythroid progenitors, granulocyte/monocyte progenitors, and fibroblastic progenitors. The EIAV had a selective suppressive effect on the erythroid progenitors. Colony-forming units-erythroid were suppressed to 80% of that for medium controls (P = 0.011). Burst-forming units-erythroid were suppressed to 70% of that for medium con...
Unusual selective immunoglobulin deficiency in an Arabian foal. A 10-month-old Arabian foal was evaluated for a suspected immunoglobulin (Ig) M deficiency. Decreased to nondetectable concentrations of IgM, IgA, and IgG (T), and a normal concentration of IgG, were present. Results of in vitro testing of the blood lymphocyte blastogenesis showed a weak response to the B-cell mitogen, lipopolysaccharide (LPS), but normal responses to T-cell mitogens. Results of postmortem examination showed synovitis of the left tibiotarsal and both scapulohumeral joints. Atrophy and edema of the lymph nodes and lymphocyte depletion in the thymus and spleen were seen. A subac...
Restriction enzyme maps for equine adenovirus 1 genome. Physical maps were constructed for the genome of equine adenovirus 1 (EAV1) using the restriction enzymes; DraI, EcoRV, NotI and SfiI. The total size of the EAV1 genome was 34.4 kb estimated by comparison with known DNA standards and the polarity of the fragment order, with respect to the left and right molecular ends, was determined by hybridization with known regions of the human adenovirus 2 (HAV2) genome.
Substrate specificities of tissue kallikrein and T-kininogenase: their possible role in kininogen processing. The present studies demonstrate the importance of subsite interactions in determining the cleavage specificities of kallikrein gene family proteinases. The effect of substrate amino acid residues in positions P3-P'3 on the catalytic efficiency of tissue kallikreins (rat, pig, and horse) and T-kininogenase was studied using peptidyl-pNA and intramolecularly quenched fluorogenic peptides as substrates. Kinetic analyses show the different effects of D-amino acid residues at P3, Pro at P'2, and Arg at either P'1 or P'3 on the hydrolysis of substrates by tissue kallikreins from rat and from horse o...
Role of the eosinophil in serum-mediated adherence of equine leukocytes to infective larvae of Strongylus vulgaris. The adherence of equine leukocytes to Strongylus vulgaris infective larvae (L3) in the presence of normal and immune sera was examined in vitro. Immune sera promoted adherence of buffy coat cells from ponies with S. vulgaris-induced eosinophilia (eosinophilic ponies) to S. vulgaris L3. However, eosinophils in the buffy coat cells were the predominant adherent cell type. Studies using leukocyte populations enriched for eosinophils, neutrophils, and mononuclear cells from eosinophilic ponies support the observations using buffy coat cells that eosinophils were the main effector cells. Adherent e...
Diversity of the antibody responses produced in ponies and mice against the equine influenza A virus H7 haemagglutinin. A large panel of mouse monoclonal antibodies was produced and tested against field isolates of the equine H7N7 influenza A virus subtype. Only a limited degree of H7 haemagglutinin variation was detected. At least four antigenic sites were identified by selecting variant viruses in eggs. The limited variation in the field did not correlate with the frequency of variant viruses detected in eggs; this frequency was similar to those reported for other influenza viruses. We sought to determine whether the limited amount of variation could be correlated with an epitope-restricted antibody response ...
Short-term effect of aldosterone on Na-Cl transport across equine colon. In ponies fed concentrated (pelleted) meals, postprandial increases of plasma aldosterone have been temporally associated with a decrease in colonic fluid volume that parallels the conclusion of postfeeding fermentation. To determine the significance of short-term increases of plasma aldosterone on the rate of colonic Na absorption, in vitro transport studies were conducted on the mucosae of three morphologically distinct colonic segments (i.e., ventral, dorsal, and small colons) from ponies infused with a high physiological concentration of aldosterone for an 8-h period. In control ponies, ba...
In vitro comparison of equine granulocytes labeled with 99mTc-hexamethylpropyleneamine oxime or 111In-oxine. Isolated equine granulocytes (WBC), radiolabeled with 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) or 111In-oxine, were evaluated in vitro for their labeling characteristics, viability, and phagocytic function over a 6-hour postlabeling period. Mean +/- SD labeling efficiency for 111In-oxine-WBC was 62.2 +/- 15.3%, which was significantly (P less than 0.001) higher than that for 99mTc-HMPAO-WBC (32.0 +/- 17.0%). In vitro elution of radiolabel from cells was significantly (P less than 0.02) greater for 99mTc-HMPAO-WBC at 0.5, 2, and 4 hours, but was not significantly different from elutio...
Equine infectious anemia virus gene expression: characterization of the RNA splicing pattern and the protein products encoded by open reading frames S1 and S2. The utilization of predicted splice donor and acceptor sites in generating equine infectious anemia virus (EIAV) transcripts in fetal donkey dermal cells (FDD) was examined. A single splice donor site identified immediately upstream of the gag coding region joins the viral leader sequence to all downstream exons of spliced EIAV transcripts. The predominant 3.5-kb transcript synthesized in EIAV-infected FDD cells appears to be generated by a single splicing event which links the leader sequence to the first of two functional splice acceptor sites near the 5' end of the S1 open reading frame (OR...
