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.
Nyindo MB, Ristic M, Lewis GE, Huxsoll DL, Stephenson EH.Four ponies experimentally infected with Ehrlichia equi developed substantial cell-mediated immune responses, as measured by the leukocyte migration-inhibition test. Serum anti-E equi antibodies up to 1:1,280 were demonstrated by the indirect fluorescent antibody test. Cell-mediated immune responses returned to a base-line value by day 200 after primary inoculation, but serum antibody titers persisted for at least 300 days after inoculation. Two additional susceptible ponies, which were inoculated with convalescent blood or organ homogenates from ponies recovered from acute equine ehrlichiosis...
Allen GP, Cohen JC, Randall CC, O'Callaghan DJ.The replication of equine herpesvirus type 1 (EHV-1) and type 3 (EHV-3) was unimpeded in three different cell types-equine epithelial cells, equine fibroblasts, and mouse fibroblasts-which had been blocked in their capacity to synthesize host DNA by 2.5 mM hydroxyurea (HU) or 2 mM thymidine (TdR). The rate of DNA synthesis in uninfected or equine herpesvirus-infected cells in the presence of HU or TdR was measured by pulse-labeling cell samples with a labeled DNA precursor at different times after infection. DNA synthesis in uninfected cultures was completely inhibited by both compounds. Howev...
Jemmerson R, Margoliash E.Of the antigenic determinants so far identified for cytochrome c, only one involves more than a single amino acid substitution between the immunogen and host proteins. Both a threonine at position 89 and a glutamic acid at position 92 control one of the three antigenic sites identified in horse cytochrome c, as expressed in rabbits. Three antibody subpopulations, all directed against this region of the molecule, were isolated from the serum of a single rabbit by adsorption on a series of insolubilized cytochromes c. Antibody fluorescence quenching titrations with a variety of cytochromes c wer...
McConnel MB, Katada M, McConnell S, Moore R.Electron microscopy was used to demonstrate the presence of viral particles in primary cultures of leukocytes taken from a horse after SC inoculation with the Wyoming strain of equine infectious anemia virus. Unlike previous studies, the exposure virus was not passaged through cell culture prior to horse inoculation. Cultures were begun approximately 1 week before and 1 week after the 1st pyrexic period after inoculation. In both samples, viral particles and cytoplasmic alterations were observed resembling those previously reported in equine infectious anemia virus and other retravirus-infecte...
Nicander L, Malmqvist M.Principal cells in the initial segment of the epididymis in horses, cattle, pigs, sheep, dogs, cats, and rabbits have an abundant, partly rough, endoplasmic reticulum and a large Golgi complex. Small vacuoles with opaque content seem to be formed by the Golgi complex and move to the cell apex, where they empty their contents into the lumen by a merocrine mechanism.
Tarr MJ, Olsen RG, Krakowka GS, Cockerell GL, Gabel AA.Erythrocyte rosette (ER) formation of equine peripheral blood lymphocytes (PBL) was characterized. Guinea pig and, to a lesser extent, human erythrocytes formed ER; cat, cow, dog, hamster, mouse, rat, and sheep erythrocytes showed negligible rosetting properties. Conditions of the assay were varied to determine which procedure allowed the largest percentage of rosette formation. The PBL from 20 normal horses were then assayed, averaging 38 +/- 2% ER. To characterize the erythrocyte receptor as being on T or B cells, equine thymocytes from 6 foals were assayed; the thymocytes formed an average ...
Butler WF, Pousty I.Disc material from horse, ox, sheep, pig, dog and cat was stained by the Alcian-blue-critical electrolyte concentration technique and with the standard and two-step periodic acid Schiff methods. The effects of pretreatment with hyaluronidase and with chondroitinase was also evaluated. There appears to be a small increase in total cellular glycosaminoglycan content with age in all species: cellular material of high molecular weight however only increases in aged animals. The degree of sulphation of cellular glycosaminoglycans does not vary with age or with position in the disc.
Jirgensons B, de Haas GH.Conformation of porcine, bovine, and equine pancreatic phospholipases A2 (EC 3.1.1.4) and their zymogens was studied by the circular dichroism (CD) probe in the far and near ultraviolet spectral zones.
All these phospholipases and their zymogens displayed CD curves suggesting the presence of moderate amounts of α-helical conformation. However, on the basis of known primary structure and recent X-ray structural analysis of prophospholipase A2 crystals (Drenth, J., Enzing, C.M., Kalk, K.H. and Vessies, J.C.A. (1976) Nature 264, 373–377), it has to be concluded that the positive CD band cen...
Gerber JD, Marron AE, Bass EP, Beckenhauer WH.The cell-mediated immune response and antibody response of horses of varying ages and of pregnant horses to equine herpesvirus 1 antigen were examined. Six to eight month old horses showed either no increase or slight increases in anti-equine herpesvirus 1 serum neutralizing antibody following vaccination and revaccination with a modified live equine herpesvirus 1 vaccine. However, these same horses showed a marked increase in the cell-mediated immune response to equine herpesvirus 1 as measured by the lymphocyte transformation test. Eighteen to 21 month old horses showed four to 64-fold incre...
Jahrling PB, Beall JL.Hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. Different conditions of pH and phosphate molarity were required to obtain satisfactory elution profiles and separations for Western equine encephalomyelitis virus strains, compared with Eastern equine encephalomyelitis virus and Semliki Forest virus strains. Raising the pH of the buffers effected earlier elutions of all viruses. Selection of phosphate gradients with more gentle slopes and adjustment to the proper pH effected better separations of virus subpopulations. Elution profiles ...
Schochetman G, Fine D, Arthur L, Gilden R, Heberling R.A new retravirus (SMRV) isolated from a squirrel monkey, Saimiri sciureus, has an Mg2+-dependen reverse transcriptase and a buoyant density of 1.17 g/cm3 in sucrose and 1.21 g/cm3 in cesium chloride, similar to the mouse mammary tumor virus and the Mason-Pfizer monkey virus. The polypeptide patter of SMRV as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was distinct from the reported polypeptide patterns of known retraviruses. Four major polypeptides of molecular weights 40,000, 20,000, 14,000 and 8,000 were resolved in virus propagated in human, mink, and canine cell...
Banerjee DP, Singh B, Gautam OP, Sarup S.An intradermal skin test, to demonstrate a delayed cutaneous hypersensitivity reaction in Babesia equi infection in donkeys, was developed. A skin reaction to B. equi antigen was elicited in vaccinnated, infected and carrier intact and splenectomised donkeys. The histopathological examination of the skin biopsy revealed infiltration of mononuclear cells and accumulation of oedematous fluid in the deeper layers of the dermis. A leucocyte migration inhibition test was developed and its specificity as an in vitro measure of cell-mediated immunity to B. equi antigen was established. The results of...
Peterman BF, Morton RA.The apparent equilibrium constant and rate of oxidation was investigated for the reaction of cytochrome c with iron hexacyanide. It was found that if horse heart ferricytochrome c was exposed to ferricyanide (to oxidize traces of reduced protein) the cytochrome subsequently, even after extensive dialysis, had an apparent equilibrium constant different from that of electrodialyzed protein. The effect of ferricyanide ion apparently cannot be removed by ordinary dialysis. The ionic strength dependence of the apparent equilibrium constant and bimolecular oxidation rate constant was measured in the...
Rose RJ, Purdue RA, Hensley W.The effects of prolonged strenous exercise on the plasma concentrations of sodium, potassium, calcium, chloride, bicarbonate, phosphate, albumin, cholesterol, glucose, creatinine, bilirubin, alkaline phosphatase, creatine phosphokinase, lactic dehydrogenase and asparate amino transferase were studied in a group of 26 horses competing in an endurance ride. There were significant changes in most parameters, when control values were compared with those taken immediately after the ride. There was also a significant correlation between several biochemical parameters and heart rate taken 30 minutes ...
Seybert DW, Moffat K, Gibson QH, Chang CK.Horse globin has been recombined with 2,4-dimethyldeuteroheme and 2,4-dibromodeuteroheme to yield the corresponding reconstituted hemoglobins, and the ligand binding reactions of these reconstituted hemoglobins have been examined in detail. Both hemoglobins exhibit relatively high n values, but 2,4-dimethyldeuterohemoglobin displays a consistently higher oxygen affinity than native hemoglobin, whereas the oxygen affinity of 2,4-dibromodeuterohemoglobin is consistently lower than that of native hemoglobin. The rate constants l’, and 1’4 for the binding of the first and fourth molecules of C...
Shahrabadi MS, Marusyk RG, Crawford TB.Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining...
Scheel J, Duswald KH, Ring J, Seifert J, Scholz S, Brendel W.Eight mongrel dogs received a standard daily i.v. infusion of 20 mg/kg b.w. deaggregated horse-anti-dog-lymphocyte-globulin (ALG) and additional prednisolone (1 mg/kg b.w. daily i.v.) over a maximum period of 82 days following pretreatment with deaggregated normal horse IgG. No sensitization against horse protein was observed during therapy of afterwards as proved by lack of humoral antibodies against horse antigens, maintained lymphopenia, good compatibility, longterm prolongation of xenogeneic skin graft survival (85.6+/-20.6 days, n=8' untreated controls 12.5+/-1.3 days, n=4) and longterm s...
Kang CH, Ferguson-Miller S, Margoliash E.1. The steady state kinetics for the oxidation of ferrocytochrome c by yeast cytochrome c peroxidase are biphasic under most conditions. The same biphasic kinetics were observed for yeast iso-1, yeast iso-2, horse, tuna, and cicada cytochromes c. On changing ionic strength, buffer anions, and pH, the apparent Km values for the initial phase (Km1) varied relatively little while the corresponding apparent maximal velocities varied over a much larger range. 2. The highest apparent Vmax1 for horse cytochrome c is attained at relatively low pH (congruent to 6.0) and low ionic strength (congruent to...
Allen GP, O'Callaghan DJ, Randall CC.Infection of cells with equine herpesvirus type 1 (EHV-1) or type 3 (EHV-3) resulted in the induction of a DNA polymerase activity distinguishable from host cell DNA polymerases by its high salt requirement for maximal activity. By column chromatography on DEAE-cellulose, DNA-cellulose, phosphocellulose, and hydroxyapatite, the EHV-1-induced polymerase was purified 500-fold with 1–2% recovery of total activity from the nuclei of infected hamster livers. The final enzyme preparation was homogeneous as judged by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Calculations based ...
Looijen MG, New DJ, Fischer CD, Dardari R, Irwin KM, Berezowski CJ, Bond SL, Léguillette R.OBJECTIVE To evaluate the mRNA expression of T helper (Th)1, Th2, and Th17 cell-associated inflammatory mediators in cells of bronchoalveolar lavage fluid samples collected from healthy horses exposed to hyperbaric oxygen (HBO) and to monitor blood oxygen concentration during and following HBO therapy. ANIMALS 8 healthy horses. PROCEDURES In a randomized controlled crossover design study, each horse was exposed (beginning day 1) to 100% oxygen at a maximum of 3 atmospheres absolute (304 kPa) daily for 10 days or ambient air at atmospheric pressure in the HBO chamber for an equivalent amount of...
Freer H, Hillegas JM, Wimer C, Baldwin C, LaBresh J, Wagner B.Interleukin-2 (IL-2) is a T cell growth factor and major modulator of T helper (Th) cell differentiation. Here, we have developed and characterized a monoclonal antibody to equine IL-2 (anti-IL-2 mAb, clone 158-1). The IL-2 mAb detected rIL-2 by ELISA, intracellular staining and flow cytometry analysis and Western blotting. The IL-2 mAb was also paired with a polyclonal IL-2 detection antibody in both ELISA and a fluorescent bead-based assay. When these two assays were compared using identical reagents there was an improved analytical sensitivity (46pg/ml) and wider linear quantification range...
Freeman KP, Roszel JF, Slusher SH, Kocan KM.Cells resembling those known as "repair cells" in gynecologic cytology specimens from women were identified in uterine cytology specimens from infertile mares treated with antibiotics using indwelling uterine catheters. This prompted a study of the effect on the equine uterus of indwelling catheterization without antibiotic infusion, using light microscopic examination of cytologic and biopsy specimens and electron microscopic examination of biopsy specimens. Cytologic and biopsy specimens had features within normal limits at the start of the study. Following five days of indwelling catheteriz...
Bugno M, Jabłońska Z, Słota E.The aim of the study was to optimize hybridization conditions of molecular probes specific for X sex chromosomes of the domestic horse in mare oocyte chromosomes. Mare oocytes, recovered from slaughterhouse ovaries by scraping the granulosa layer, were cultured in vitro. Metaphase II mature oocytes were treated with hypotonic solution and fixed, followed by hybridization of the molecular probe specific for the X chromosome ofthe domestic horse. Hybridization of probes specific for mouse heterosomes on mouse oocytes and early embryos was performed to verify the FISH technique. Of 438 oocytes an...
Moor RM, Allen WR, Hamilton DW.Biochemical and morphological studies were carried out to determine the origin and histogenesis of endometrial cups in mares. A wide range of fetal and maternal tissues were cultured in vitro and their ability to secrete gonadotrophin (PMSG) was monitored. High levels of PMSG were produced in culture only by cells from the restricted area of the equine trophoblast known as the chorionic girdle which is an annular band of highly specialized cells at the junction of the allantois and the regressing yolk sac. The morphological appearance of girdle cells after cultivation in vitro and after alloge...
Ząbek T, Witarski W, Semik-Gurgul E, Szmatoła T, Kowalska K, Samiec M.Ex vivo expansion of chondrocytes in monolayer (ML) culture for therapeutic purposes is burdened with difficulties related to the loss of cartilaginous phenotype. Epigenetic mechanisms responsible for regulation of gene expression are believed to underlie chondrocyte dedifferentiation. We have inspected the relevance of DNA methylation alterations for passage-related differential expression of NFATC1 gene involved in hard connective tissue turnover and development, NADSYN1 influencing redox metabolism, and JAK3 - an important driver of inflammation. We have assessed relative amount of transcri...
Brostroöm H, Paulie S, Perlmann P.To characterise the expression of surface antigens on equine sarcoid cells compared to normal equine fibroblasts, immune sera were produced in rabbits against transformed cells of a virus-containing sarcoid cell line (Mc-1) and normal dermal fibroblasts, respectively. The specificities of the sera were analysed by antibody-dependent cellular cytotoxicity against 51Cr-labelled target cells using human lymphocytes as effector cells. Anti-Mc-1 antiserum induced strong cytotoxicity against transformed cells of two sarcoid cell lines (Mc-1 and Bay Mc-1), whereas the cytotoxicity against transformed...
Horohov DW, Keadle TL, Pourciau SS, Littlefield-Chabaud MA, Kamerling SG, Keowen ML, French DD, Melrose PA.Intense exercise affects various parameters of the immune system. The overall effect of exercise on immune function is dependent upon the physical condition of the subject, the intensity and duration of the exercise period, and the immune parameter assessed. Unconditioned horses subjected to a single bout of intensive exercise exhibit multiple alterations in immune function, including an augmentation of lymphokine activated killer (LAK) cell function. This increase in LAK cell activity is not due to an increase in circulating LAK precursors. While peripheral blood mononuclear cells from exerci...
Richardson DW, Dodge GR.The complete nucleotide sequence of equine type II procollagen has not been previously reported, and equine-specific probes have not been available. We report the complete sequence and discuss the molecular characteristics of equine type II procollagen mRNA which was cloned from a cDNA library prepared from mRNA isolated from equine articular chondrocytes. The coding sequence (4257 bp) was 92.4% homologous to the cDNA of the human sequence, and the propeptide was 97% identical to the human sequence. We demonstrated that when equine chondrocytes are grown in phenotypically-maintained cultures, ...
Simpson CF, Buergelt CD.The alveoli of the lungs of 2 aborted foals contained elongated, dense bodies when examined histologically and by transmission and scanning electron microscopy. By light microscopy, the bodies (10 to 40 micrometers in size) stained intensely with the Gram stain, and up to 10 were present within an alveolus. Electron microscopy determined that such bodies were not cellular in origin but appeared to be a congealed fluid product composed of layers of fibrillar-like material. From the human literature, it was concluded that these intraalveolar bodies were probably congealed amniotic fluid.
Malekinejad H, Alizadeh-Tabrizi N, Ostadi A, Fink-Gremmels J.The pathogenesis of equine grass sickness (EGS) has not fully understood. A better understanding of the exact pathogenesis of diseases can help to make an accurate diagnosis. Previous studies reported some pathological damage of neuronal cells in EGS patients. In this study, primarily cytotoxicity of serum from three clinically EGS-diagnosed horses on PC12 Tet-off (PTO) cells was assessed. Subsequently, the apoptotic tests including cytochrome C release, caspase-3/7 activity measurement and DNA fragmentation assay were conducted to clarify the apoptotic effect of serum from EGS patients. Addit...
Hendrix DV, Newkirk KM.To determine whether epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are expressed in periocular squamous cell carcinomas (SCCs) of horses. Methods: Biopsy specimens of SCCs from 46 horses. Methods: Pathology records were searched retrospectively for biopsy specimens of periocular SCCs obtained from horses. Slides of the specimens were reviewed histologically to confirm the SCC diagnosis and stained for EGFR and HER2 by immunohistochemical methods. For both EGFR and HER2, the immunohistochemical staining intensity and percentage of stain-positive cel...
Coruzzi G, Poli E, Bertaccini G.The effects of nifedipine, verapamil and diltiazem were investigated in the isolated mare uterus in comparison with salbutamol. All the calcium-channel blockers and salbutamol inhibited the spontaneous, KC1- and electrically induced contractions; nifedipine and salbutamol were the most potent compounds. The calcium agonist Bay K 8644 (10(-8)-10(-6) mol/l) competitively antagonized the inhibitory effect of nifedipine (pA2 value = 8.54 +/- 0.06), whereas it was only slightly or totally ineffective against verapamil, diltiazem and salbutamol. These results indicate that calcium-channel blockers a...
Ball BA.There are considerable differences between mammalian species in the distribution and activity of ciliated cells within the oviduct, and limited information is available concerning either the distribution or activity of cilia within the equine oviduct. Patterns of ciliary activity were characterized in the ampulla and isthmus of oviducts recovered at 2 d after ovulation from 10 mares, and scanning electron microscopy was used to examine regional differences in the distribution of cilia in oviducts from 3 of these mares. Based upon the motility of 15 microm latex microspheres, ciliary activity w...
Harland MM, Fedele C, Berens v Rautenfeld D.Horses are highly susceptible to lymphedema. Knowledge of the morphological components of lymphatic collectors is therefore essential to understanding the function of the lymphatic system. A better knowledge of the lymphatic system allows the development of more effective treatments against lymphedema. The composition of hypodermal and deep lymphatic collectors was investigated with immunohistochemical staining, using antibodies against proteins of the collector walls from the skin in the hind limbs of 10 healthy horses. Lymphatic collectors can be subdivided into passive (elastic fibers) and ...
Schuberth HJ, Hadam M, Leibold W.The determination of differentiation and transplantation antigens will be of growing importance in immune diagnosis for individual animals as well as for breeding purposes in populations. Differentiation antigens characterize subsets of cell populations and indicate their functional capacity while transplantation antigens represent markers of individuals of a species. Occurrence and significance of these antigenic systems are briefly reviewed.
Valpotić I, Kastelan M, Rudolf M, Gerencer M, Jukić B, Basić I.The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
de Oliveira AC, Rosenbruch M, Schulz LC.The morphology of asteroid bodies in equine arteries is demonstrated by light microscopy as well as by scanning and transmission electron microscopy combined with chemical analysis. Asteroid bodies first occur in horses at four weeks of age in all investigated tissues except the esophagus and always are located in the subendothelial space. The number, shape, ultrastructure and chemical composition of asteroid bodies differ markedly--depending on the age of the horse. Asteroid bodies are round and smooth in foals, but are shaped irregularly and have several projections and marked stratified cal...
Vagnoni KE, Ginther OJ, Lunn DP.Chorionic girdle cells are a highly invasive subpopulation of trophoblastic cells of the horse conceptus that adhere to the uterine epithelium and begin to invade the endometrium on Days 34-36 (Day 0 = day of ovulation). Just prior to and during invasion (Days 32-36), chorionic girdle cells express high levels of major histocompatibility complex (MHC) I, but expression of this antigen decreases by Days 40-45 and is lost by Day 55. The mechanisms involved in the control of chorionic girdle cell invasion and altered MHCI expression over time are not known. The objective of this study, therefore,...
Bochsler PN, Slauson DO, Chandler SK, Suyemoto MM.The use of cultured tissue has not yet become widespread in research involving equine disease, and this may be attributable in part to the scarcity of published reports concerning tissue culture methods for this species. We report here the isolation of equine microvascular endothelium (EMVE) from fresh omental tissue of horses and ponies. Fresh donor tissue was minced, subjected to collagenase digestion, and filtered. Cells were layered on 5% bovine serum albumin for gravity sedimentation, the bottom layer was collected, and the cells were plated onto fibronectin-coated flasks. Medium consiste...
Chidambaram RM, Eades SC, Moore RM, Hosgood G, Venugopal CS.To characterize the in vitro response of equine cecal longitudinal smooth muscle (CLSM) to endothelin (ET)-1 and assess the role of ETA and ETB receptors in those ET-1-induced responses. Methods: 36 horses without gastrointestinal tract disease. Methods: To determine cumulative concentration-response relationships, CLSM strips were suspended in tissue baths containing graded concentrations of ET-1 (10(-9) to 10(-6)M) with or without BQ-123 (ETA receptor antagonist); with or without IRL-1038 (ETB receptor antagonist); or with both antagonists at concentrations of 10(-9), 10(-7), and 10(-5)M. To...
Johnson L, Nguyen HB.Stereological methods were employed in two experiments with adult stallions: to confirm seasonal variation in number of Sertoli cells and to characterize the annual cycle of the Sertoli cell population. In the first experiment, testes from 28 adult (4-20 years old) horses obtained in the non-breeding season (December-January) were compared to testes from 28 adult horses in the breeding season (June-July). Sertoli cell numbers were calculated from the nuclear volume density, parenchymal volume, and volume of an individual Sertoli cell nucleus determined by reconstruction of serial sections or f...
Lavoie-Lamoureux A, Martin JG, Lavoie JP.Neutrophils are the predominant cells recruited in the airways of horses suffering from heaves. These cells have been shown to express arginase in some species. The metabolism of l-arginine is thought to be involved in chronic inflammation, and airway obstruction and remodeling. The aim of this study was to assess the expression, regulation, activity, and functional role of arginase isoforms in equine neutrophils. Arginase I, arginase II, ornithine decarboxylase (ODC) and ornithine aminotransferase (OAT) expression were assessed in resting and stimulated (IL-4, LPS/fMLP, PMA; 5 and 18 h) blood...
Magma (New York, N.Y.)October 4, 2019
Volume 33, Issue 2 299-307 doi: 10.1007/s10334-019-00781-z
Palfrey RM, Summers IR, Winlove CP.Quantitative magnetic resonance imaging was used to determine partition coefficients and characteristic time constants for diffusion of MRI contrast agents in disc tissue. Methods: Twenty-two excised equine intervertebral discs were exposed to a range of contrast agents: six to manganese chloride, eight to Magnevist (gadopentetate dimeglumine) and eight to Gadovist (gadobutrol), and uptake into the disc was quantified in T-weighted images. Results: Diffusion for all contrast agents was approximately 25% faster in the nucleus than in the outer annulus; disc-average time constants ranged from (2...
Watson ED, Zanecosky HG.Fluid was aspirated from the preovulatory follicles of mares before and 12, 24 and 36 h after intravenous administration of hCG. Follicular fluid significantly (P less than 0.001) reduced lymphocyte blastogenesis in vitro and, at a dilution of 1:100, fluid collected at 36 h after administration of hCG was significantly more suppressive (P less than 0.01) than fluid collected before 36 h. Suppression of blastogenesis was reduced by extracting the follicular fluid with ether or by charcoal treatment (P less than 0.01) or by heating at 56 degrees C for 30 min (P less than 0.05). Preincubation of ...
Stewart M.The structure of vertebrate skeletal muscle is reviewed. The mechanism of muscular contraction and its control is then discussed from the point of view of molecular structure. Contraction takes place by a sliding filament mechanism produced by cross-bridges which form between thick and thin filaments. Control is exercised by tropomyosin and troponin. When the calcium concentration is low, these proteins interfere with the formation of cross-bridges and prevent contraction, but when the calcium concentration is increased, they no longer interfere and contraction proceeds.
Dagleish MP, Pemberton AD, Brazil TJ, McAleese SM, Miller HR, Scudamore CL.Man and horses both suffer from neutrophil mediated pulmonary diseases however there are striking species differences in the underlying pathology. In particular while pulmonary emphysema is a common pathological sequel to human respiratory disease it is not a major feature of the common equine neutrophil mediated condition, chronic obstructive pulmonary disease (COPD). The proposed reason for this difference is that equine neutrophils contain less elastase than equivalent human cells and therefore there is a reduced risk of excess and/or uninhibited elastase activity, which is considered the m...
Murabayashi H, Hondo E, Kitamura N, Furuoka H, Taguchi K, Nambo Y, Yamada J.One of the most attractive characteristics of a horse testis is the change of the weight during development. As the testicular weight changes and the number of Leydig cells decreases, pigments appear in interstitial tissues. In the present study, the characteristics of the pigments found in the interstitial tissues were examined histochemically and ultrastructurally. Specific stainings indicated that the pigmented granules showed almost all of the histological and histochemical characteristics of ceroid or ceroid-like pigment. The cells showed positive reaction for acid phosphatase while the p...
Willis P, Caudle AB, Fayrer-Hosken RA.Transmission electron microscopy (TEM) was used to evaluate the fine structure of equine oocytes cultured in vitro. Oocytes obtained by follicular aspiration were cultured for either zero or 15 hr. After treatment oocytes were processed either by light microscopy (nuclear evaluation) or TEM (cytoplasmic evaluation). Those oocytes cultured for 15 hr were incubated in modified TCM 199 with 15% (v/v) mare serum (day of ovulation) at 39 +/- 0.2 degree C. Evaluation using TEM revealed that cortical granules were present in all oocytes. However, zero-time oocytes contained few cortical granules, and...
Kempson SA, Campbell EH.The permeability barrier in the dorsal wall of the equine hoof capsule was studied by means of horseradish peroxidase (HRP) in 0.9 N saline solution as a water soluble tracer. Section were treated with 3'3'-diaminobenzidine tetrachloride (DAB) and before dissection the quality of the horn of feet from 10 horses was assessed and given a subjective grade as either good or poor. Blocks of tissue from each horse were left in either an oven at 60 degrees C or in water for 2 weeks before treatment in HRP, sectioning and DAB solution. Regions observed were i) outer surface, ii) outermost layers of th...
