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Topic:Cells
The study of cells in horses encompasses the examination of various cell types and their functions within the equine body. Cells are the basic structural and functional units of life, and in horses, they contribute to numerous physiological processes, including growth, repair, and immune responses. Different cell types, such as red blood cells, white blood cells, and muscle cells, each perform specific roles that are vital for maintaining the health and homeostasis of the horse. This topic includes research on cellular mechanisms, cellular responses to disease or injury, and the application of cellular biology in equine medicine. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and significance of cells in equine biology and health.
Pyrimidine metabolism in peripheral and phytohemagglutinin-stimulated mammalian lymphocytes. 1. Activity of uridine kinase was very low in ovine lymphocytes and in those of some pigs. Lymphocytes of other pigs showed a significantly higher activity of this enzyme. Activity of uridine kinase in lymphocytes of man, horse and cattle was intermediate. 2. Activity of uridine phosphorylase was higher than that of uridine kinase with lymphocytes of all species. 3. Activity of uridine kinase in equine lymphocytes increases at PHA-stimulation and also in porcine lymphocytes with a low activity at the start of the culture. Activity of uridine kinase decreased in porcine lymphocytes with a high ...
Characterization of the major antigens of Haemophilus equigenitalis (contagious equine metritis organism). Immunoelectrophoresis of ultrasonically disrupted Haemophilus equigenitalis (contagious equine metritis organism) cells against rabbit and equine antisera disclosed at least 11 precipitating antigens. Two of these, a polysaccharide and a lipopolysaccharide-protein complex, were of high molecular weight and located on the cell surface. The remaining antigens were intracellular and were small- to medium-sized proteins. The surface antigens were the most significant in relation to the serological response in infected horses. They also reacted with sera from apparently healthy cattle, but the reas...
Isolation of equine neutrophils and analysis of functional characteristics by chemiluminescence and bacterial assays. Equine neutrophils (PMN) were isolated to greater than 99% purity by isopyknic sedimentation on coated colloidal silica particles. A cell recovery of 84.7 +/- 4.0%, with a viability of greater than 99%, was observed with this method. The isolated PMN were compared with mixed population of equine peripheral leukocytes with respect to functional integrity by chemiluminescence and bactericidal assays. There was no significant difference (P less than 0.01) observed in either assay between the isolated equine PMN and the mixed-cell populations. The methods used in both the isolation as well as the ...
The uptake of mepacrine by horse polymorphonuclear leucocytes in vitro. The uptake of mepacrine by isolated horse polymorphonuclear leucocytes (PMN) was measured using spectrophotofluorimetry. Two phases of uptake were observed, the first, rapid fraction, essentially complete by 10 min, and a second, slow fraction, which was still proceeding after 60 min. The appearance of mepacrine within the PMN was also visualized by fluorescence microscopy. Discrete yellow points of fluorescence were observed in the cytoplasm of PMN within 30 s. These discrete points corresponded both in size and number to the PMN granules. After 5 min, the nuclei showed faint fluorescence whi...
Lysosomal hydrolase activity in leucocytes from cattle, sheep, goats, horses and pigs. Activities of lysosomal hydrolases were measured in the leucocytes of cattle, sheep, goats, horses and pigs. There was high activity of arylsulphatase in leucocytes from cattle, high activities of alpha-fucosidase and beta-glucuronidase in leucocytes from horses and high activity of acid phosphatase in granulocytes from pigs. Within species, arylsulphatase and beta-galactosidase activities were higher in granulocytes than in mononuclear cells, but beta-glucuronidase, phosphodiesterase and alpha-galactosidase activities were higher in mononuclear cells than in granulocytes. Eosinophils of cattl...
Connective tissue composition of the equine sarcoid. The connective tissue composition and organisation of the "equine sarcoid" was compared with that of normal adult equine skin to determine whether the cells which produce their respective connective tissue matrices show similar biosynthetic characteristics. No major qualitative difference could be found between the collagen compositions of skin and sarcoid material, although the organisation into fibres of Type III collagen in the sarcoid was markedly greater than that of skin.
Observations on the isoenzymes of aspartate aminotransferase in equine tissues and serum. The distribution of the isoenzymes of aspartate aminotransferase (AST, E.C. 2.6.1.1.) in equine tissues has been studied to ascertain whether the organ of origin may be identified when the total AST activity of serum is raised. Most tissues contain 3 isoenzymes of cytoplasmic origin (cAST) with isoelectric points of 5.6, 5.7 and 5.9, and one isoenzyme of mitochondrial (mAST) origin with an isoelectric point of 9. Serum from horses with azoturia contained an additional cytoplasmic subform with an isoelectric point of 5.8. This form could not be generated by ageing, freezing and thawing or bindi...
Mononuclear phagocytes of peritoneal fluid. Cells in the peritoneal fluid from 179 horses were examined in Giemsa stained preparations using light microscopy. Mononuclear phagocytes were a common cell type observed in normal fluids. In the absence of stimulation they were morphologically similar to the peripheral blood monocyte and the unstimulated mesothelial cell. In acute inflammatory effusions their proportion decreased significantly but, as the condition resolved, monocytes began to migrate into the cavity gradually becoming more numerous, transforming into larger macrophages and assuming an increasing phagocytic role. They were of...
[Some physicochemical properties of native and polymerized glutaraldehyde-treated horse heart cytochrome c]. Glutaraldehyde treatment does not change the absorption of cytochrome c either in the visible or in UV spectra. It brings about the formation of dimers, trimers and high-polymeric forms of cytochrome c and shifts the pI of all cytochrome c isoelectric fractions to more acid pH. Polymerization also results in changes of kinetic parameters of cytochrome c benzidine reaction increasing its affinity to 3,3-diaminobenzidine with a simultaneous decrease in the effectiveness of H2O2 binding. These biochemical changes can be related to immunochemical differences of native and glutaraldehyde-treated cy...
Morphometry of equine neutrophils isolated at different temperatures. Equine neutrophils were evaluated ultrastructurally and by morphometric analysis. Homogeneous populations of neutrophils were isolated from peripheral blood at 4 degrees and 22 degrees C by centrifugation on two sequential Ficoll-Hypaque density gradients. Isolation procedures at both temperatures resulted in neutrophil degranulation but not cell swelling. Degranulation was more extensive in cells isolated at 22 degrees C. Isolation temperature affected the neutrophil content of secondary granules more than primary granules. A granule similar to immature specific granules of human neutrophils ...
Pilar neurocristic hamartoma: its relationship to blue nevus and equine melanotic disease. 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.
The effects of thermal stimulation on the ultrastructure of the fundus and duct of the equine sweat gland. Sweating in the horse had little effect on the ultrastructure of the glandular duct, other than on the lumen which enlarged. The fundus secretory cells, which in the resting gland were packed with vesicles, gradually lost them as sweating progressed until, after 4 hours of activity, few remained. Sweat appeared to be largely the product of secretion (a) by fluid transport, probably involving a region of complex cellular interdigitations adjacent to the basement membrane and (b) by exocytosis of vesicles, although a secondary mechanism of vesicle loss by micro-apocrine secretion may occur. Howe...
The enzymic reduction and kinetics of oxidation of cytochrome b-245 of neutrophils. 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...
Stimulation by phytohaemagglutinin of peripheral blood lymphocytes from horse, pig, sheep and man. 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.
Epidemiological significance of Venezuelan equine encephalomyelitis virus in vitro markers. 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...
Energy metabolism of the contagious equine metritis bacterium. 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...
Cytotaxin-induced cAMP peak in granulocytes: its relationship to crawling movements, chemokinesis and chemotaxis. The relationship between the short transient intracellular increase in cAMP levels on the one hand and chemotaxis or crawling movements on the other hand was investigated using human and equine granulocytes. C5ades arg, f-met-leu-phe, human serum albumin and immunoglobulin were used as stimulating agents. There was no strict correlation between the induction of crawling movements or of chemokinesis in general and the generation of the cAMP peak. But there was so far a strict parallelism between the occurrence of the chemotactic response and the cAMP peak. However, the magnitude of the peak was...
The conformational transition of horse heart porphyrin c. 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...
Chemotaxis of horse polymorphonuclear leukocytes to N-formyl-L-methionyl-L-leucyl-L-phenylalanine. Horse polymorphonuclear leukocytes (PMN) isolated from horse blood by sedimentation and isotonic lysis and having about 25% accompanying lymphocytes were as effective at chemotaxis as nearly pure PMN isolated by density gradient techniques. N-Formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP), used as a representative of the formylmethionyl peptides (produced by prokaryocytic organisms), was effective as a chemoattractant only at the high concentration of 10(-4) M. When serum was preincubated with FMLP at concentrations as low as 10(-8) M, the serum attracted horse PMN. This activity was not g...
Chemotaxis of radiolabeled equine neutrophils. 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...
Purification of horse eosinophil peroxidase. 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, ...
Isolation and some properties of equine alpha 1-antitrypsin. 1. Equine alpha 1-antitrypsin was isolated from horse plasma by a combination of ammonium sulfate and acidification precipitation followed by ion-exchange chromatography on DEAE-cellulose, molecular sieve chromatography on Sephadex G-200 and affinity chromatography on Cibacron Blue-agarose. 2. The purified protein showed a single precipitin arc on immunoelectrophoresis in agarose but gave two bands on discontinuous polyacrylamide gel electrophoresis (PAGE). 3. Both bands appeared to interact equally with trypsin and were thought to represent two isoinhibitors of equine alpha 1-AT.
