Ultrastructure refers to the detailed architecture of biological cells as observed through electron microscopy. In horses, the study of cellular ultrastructure provides insights into the organization and function of various tissues and organs at a microscopic level. This includes the examination of cellular components such as mitochondria, endoplasmic reticulum, and lysosomes. Understanding the ultrastructure of equine cells aids in identifying cellular changes associated with disease processes, developmental stages, and physiological adaptations. This page compiles peer-reviewed research studies and scholarly articles that explore the ultrastructural characteristics of equine cells and tissues, contributing to a deeper understanding of equine biology and pathology.
Cheville NF, Prasse K, van der Maaten M, Boothe AD.A newborn foal developed generalized cutaneous mastocytosis characterized by multiple elevated nodules of mast cells in skin and basophil hyperplasia in bone marrow. Skin lesions began as small aggregates of mast cells that progressively enlarged, ulcerated, and regressed spontaneously. Eosinophil infiltration, collagen necrosis, and fibroplasia were characteristic of advanced lesions. Many new lesions developed during the first month of life but numbers progressively diminished. Large numbers of mast cells were present in biopsies of lymph node, spleen and bone marrow. Discrete aggregates of ...
Fong CK, Hsiung GD.Development of equine herpesvirus strain 82A was studied in cells from primary horse kidney (HOK) cultures and an equine dermis (ED) cell strain. HOK and ED cells are equally susceptible to the 82A virus infection and yield about the same amount of infectious virus. Intranuclear inclusions were present in both cell systems, but a ring-shaped syncytial formation was observed only in infected ED cells. Ultrastructural studies revealed the presence of dense granules 30 nm in diameter and characteristic star-like clusters of granules in the infected HOK cells, but these granules were rarely seen i...
Garcia-Tamayo J.The mode of development of Venezuelan equine encephalomyelitis virus and the activity of acid phosphatase in the central nervous system of newborn mice were investigated. Precursor particles appeared to be formed in masses of viroplasm, migrating to the membrane of the Golgi cisterns and vacuoles or to the plasma membrane and being transformed into mature viral particles by budding. Mature viral particles were also found in the lumen of the blood vessels and around the myelin sheath of axons. Increased number of Golgi complexes and depletion of polysomes were the main ultrastructural alteratio...
Fulton RE, Doane FW, Macpherson LW.Combined light and electron microscopy were used to follow the sequence of virus development in equine papillomas. The deepest layer in which virus was observed was the stratum spinosum of the epidermis. In this layer virus was scattered throughout the nuclei and was occasionally found in association with the nucleolus. In the stratum granulosum virus particles were more numerous, often forming isolated nuclear aggregates. Virus inclusions observed in the stratum granulosum by electron microscopy were correlated with nuclear inclusions seen by light microscopy. In the stratum corneum closely p...
Tajima M, Nakajima H, Ito Y.Equine infectious anemia (EIA) virus was observed in thin sections of infected cultured horse leukocytes by electron microscopy. The virus particles had a spherical shape and were between 80 and 120 nm in diameter. Most of them contained an electron-dense nucleoid 40 to 60 nm in diameter. They were observed to form by a process of budding from the plasma membrane and appeared to have thin surface projections. The particles described were not detected in uninfected cultured cells, and their appearance could be prevented by adding EIA immune serum to the inoculum. The implications of these findi...
Bykovsky AF, Yershov FI, Zhdanov VM.Morphogenesis of Venezuelan equine encephalomyelitis virus was studied by means of electron microscopy. Virus-specific structures (factories, viroplasts) were found at early stages of infection; these structures were composed of fibrillar and cylindrical formations, aggregates of ribosomes, and viral nucleoids. The latter emerged from fibrillar and cylindrical structures. Aggregates of viral nucleoids were found in the cytoplasm and occasionally in the nuclei of virus-infected cells. Viral envelopes and mature virions were formed on the cell membranes and on the membranes of intracellular vacu...
Williams MA, Harrison PM.Horse ferritin was fractionated both by starch-gel electrophoresis and by gel filtration on Sephadex G-200. Monomer fractions contained up to 98% of monomer and oligomer fractions up to 76% of oligomers as determined by quantitative electron microscopy. Percentages obtained from electron micrographs correlated well with analytical starch-gel electrophoretograms and ultracentrifuge patterns. Amino acid analyses of monomer- and oligomer-enriched fractions showed no significant differences. Ferritin oligomers did not apparently dissociate on dilution for electron microscopy or on storage. Apoferr...
Grandi D.An ultrastructural and immunohistochemical analysis was performed on the epiphysis of two species of mammals: mink and horse. These animals present a reproductive cycle that varies along the year according to the light exposition. The aim of the study was to define possible structural changes connected with the gonadal activity. Structural aspects in common emerged such as those in concern with the epiphysis cells, their immunocytochemical characteristics (NSE and Synaptophysin positivity of pinealocytes, as well as CFAP positivity of further cells), and those in concern with the general ultra...
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...
Boudouard M, Giudicelli J, Sudaka P.A rapid method for preparation of brush border membrane vesicles from a large amount of horse kidney cortex is described. Self-orienting Percoll-gradient centrifugation minimized contamination by microsomal membranes. The characteristics of this preparation were checked by electron microscopy and measurement of L-alanine uptake.
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...
Van Driessche K, Ducatelle R, Chiers K, Van Coster R, van der Kolk JH.Very few mitochondrial myopathies have been described in horses. Objective: To examine the ultrastructure of muscle mitochondria in equine cases of myopathy of unknown origin. Methods: Biopsies of vastus lateralis of the Musculus quadriceps femoris were taken predominantly immediately post mortem and processed for transmission electron microscopy. As a result, electron micrographs of 90 horses in total were available for analysis comprising 4 control horses, 16 horses suffering from myopathy and 70 otherwise diseased horses. Results: Following a thorough clinical and laboratory work-up, four o...
Breit S, Stiglhuber A, König HE.Striking synovial structures were taken and their surface was investigated by scanning electron microscopy. Depending where the probes were taken from, the stratum synovial was arranged in a different way. The synovial intima seems to miss under the tendon of the long/commune extensor muscle, the collateral ligaments and the sesamoidean collateral ligaments. That is why the subsynovial tissue forms the superficial layer. The surface of the probes taken sidewards to the tendon of the extensor muscle and of the synovial fold, which is situated between the metacarpus/metatarsus and the proximal p...
Tunón AM, Rodriguez-Martinez H, Haglund A, Albihn A, Magnusson U, Einarsson S.Cyclical accumulation of uterine fluid occurs during oestrus and is often seen in excessive volumes in mares considered susceptible to endometritis. Since the mechanisms behind the formation of free uterine fluid remain to be clarified, the fine structure of the secretory equine endometrium was studied in biopsies collect during videoendoscopy from 14 endometritis-free, 4-9-year-old mares during oestrus. A distinct oedema of the tunica mucosa was evident. The surface epithelium had both ciliated and nonciliated cells and, particularly at the uterine body, often presented intra-epithelial macro...
Hinchcliff KW, McGuirk SM, MacWilliams PS, Cooley AJ.Changes in renal function, determined by pharmacokinetics of phenolsulfonphthalein (PSP), and renal morphologic features were examined in adult pony mares given 20 mg of gentamicin sulfate/kg of body weight, IV, q 8 h (group A) n = 7 or isotonic saline solution, IV, q 8 h, n = 5 (group B) for 14 days. Susceptibility of ponies to gentamicin-induced nephrotoxicosis was varied. Two group-A ponies developed acute renal failure and were euthanatized before treatment day 14, whereas 5 group-A A ponies did not develop physical or behavioral abnormalities after 14 days of gentamicin administration. Al...
Gebhart W, Niebauer GW.The morphological substrates of pigmented and depigmented skin as well as the structural characteristics of spontaneously developing melanomas were revealed by clinical, light- and electron microscopic methods in gray horses (Lipizzaner breed) from the Vienna Spanish Riding School. On clinical investigations in a group of 31 older horses (more than 10 years old) 20 exhibited melanomas, whereas 23 younger animals (less than 10 years of age) had no evidence for visuable melanotic tumors. Concomitantly with the progressive graying of the hair a depigmentation of the skin was frequently observed. ...
Vogelsang MM, Kraemer DC, Potter GD, Stott GG.Oocytes recovered by follicular aspiration were evaluated by light and transmission electron microscopy. Of the 22 oocytes, 4 exhibited characteristics of degeneration, and the remaining 18 were in various stages of meiotic development. Of the non-degenerate oocytes, 14 were in the germinal vesicle stage, 2 had undergone nuclear membrane disintegration, 1 displayed chromosomes in late metaphase I-early anaphase I, and 1 oocyte was in the process of extrusion of the first polar body. Although some oocytes retained complete cumulus cell investments, oocytes were predominantly enclosed only by th...
López ML, Fuentes P, Retamal C, De Souza W.The occurrence, localization and ultrastructural characteristics of a blood-tissue barrier throughout the stallion proximal seminal excurrent duct system were studied by the exclusion of electron-dense tracers and freeze-fracture techniques. Striking differences were observed in the distribution of lanthanum tracer and in the geometrical organization of the zonulae occludentes along the ductus efferentes, epididymides and vas deferens. The zonulae occludentes domain, the principal structural component of the blood-epididymis barrier, differed in permeability, width and strand numbers along the...
Turek JJ, Lamar CH, Fessler JF, Bottoms GD.An in vitro system of cultured equine endothelial cells was evaluated as a model for endotoxin (ET) exposure in the horse. Primary cell lines from pulmonary vessels and aortas were cultured from tissues of 6 horses. Effects of ET alone with and without serum and in combination with the cyclo-oxygenase inhibitor flunixin meglumine and isolated equine neutrophils were evaluated by transmission electron microscopy. Cells plus serum were incubated with 10, 25, 50, or 100 micrograms of ET/ml of incubation medium for 1, 3, 8, or 24 hours. Cells without serum were cultured for 1 and 3 hours. Flunixin...
Oikawa M, Ohishi H, Katayama Y, Kushiro A, Yoshikawa H, Yoshikawa T.A mass developed in the mandibular gingiva of a thoroughbred racehorse. When the horse could no longer eat unassisted, it was killed and immediately autopsied. Macroscopically, the mandible exhibited extensive osteolysis, with only a small amount of bone remaining around the tooth roots. The cut surface of the mass around the mandible consisted of neoplastic medullary tissue, in which osteogenesis was observed. The medullary tissue was composed of pleomorphic medium-sized to large cells, interlaced by collagen bundles. These cells had large, pale, round or ovoid, sometimes cleaved nuclei, with...
Aleman M, Lecouteur RA, Nieto JE, Williams DC, Stanke NJ, Shelton GD.Sarcoplasmic masses in humans have been associated with various myopathies, although the significance remains elusive. Similar structures have also been observed in equine muscle. The aim of this study was to determine the frequency of such structures in normal and abnormal equine muscle, and to characterize these structures using histological, histochemical, immunohistochemical, ultrastructural, and morphometric analyses. The histological and histochemical appearance was similar to that of human sarcoplasmic masses with a central or subsarcolemmal distribution. Of interest was a predilection ...
Al-Bagdadi FK, Eilts BE, Richardson GF.Scanning electron microscopy (SEM) was used to study the endometrium of nine 1-year-old thoroughbred mares after twice intrauterine infusions of gentamicin, on 2 consecutive days. Five mares were infused on 2 consecutive days with 40 ml gentamicin (50 mg/ml) mixed with 80 ml of normal saline. Four mares served as controls and were infused with 120 ml of saline on 2 consecutive days. Endometrial biopsies were obtained from all mares 3 days after the second intrauterine infusion. Each biopsy was processed for SEM by standard methods. The endometrial epithelium of the gentamicin-infused mares had...
Altunay H.The fine structure of the retinal pigment epithelium (RPE), Bruch's membrane and choriocapillaris was investigated by light and transmission electron microscopy in both the tapetal and non-tapetal fundus of the horse eye. In all locations, the RPE consisted of a single layer of low cuboidal cells. The epithelial cells were joined laterally by apically located tight junctions. These cells displayed numerous basal infoldings and abundant thin apical processes which enclosed the rod outer segments. The epithelial cell nuclei were large and located basally. Within the epithelial cells, smooth endo...
Hago BE, Vaughan LC, Plummer JM.A transmission electron microscope study was undertaken to investigate the details of the synovial tendon sheath and bursal lining in horses. The lining cells appeared to be fibroblasts and were buried in a finely granular ground substance. Generally these cells had poor cytoplasmic organelles, sparse short profiles of rough endoplasmic reticulum (RER), few scattered ribosomes and, occasionally, a poorly developed Golgi complex. However, a few lining cells appeared more active, having pronounced RER with dilated cisternane. The surface of the lining cells, particularly those with dilated RER, ...
Staszyk C, Jackowiak H, Godynicki S, Gasse H.The microvascularisation of the equine non-glandular gastric mucosa was investigated using corrosion casts for scanning electron microscopy. Specimens from 11 healthy horses were examined. Corresponding to the high incidence of gastric lesions in the margo plicatus, special attention was paid to the differentiation between the pars nonglandularis and the margo plicatus as a distinct area of the aglandular mucosa. In both areas, the blood vessels of the lamina propria mucosae were arranged in three vascular layers; i. e. I) a basal, II) an intermediate, and III) a subepithelial horizontal level...
Mishra PC, Leach DH.The venous organisation of the dermal lamellae of the equine hoof wall of 18 pairs of forelimb hooves from clinically healthy horses was studied using plastic vascular corrosion casts, and scanning electron microscopic and histological techniques. A consistent pattern of venous organisation was observed in the dermal lamella of the toe, quarter and heel regions. The lamellar corium had an extensive interconnecting capillary network which drained into axially located veins of the primary dermal lamella. Many of the capillaries had a proximodistal orientation and most of those located at the int...
Germanà A, Cassata R, Cristarella S, Scirpo A, Muglia U.The three-dimensional architecture of the myosalpinx in the mare was investigated by means of scanning electron microscopy (SEM) after removal of interstitial connective tissue with NaOH digestion. In the extramural portion of the tubo-uterine junction (TUJ), isthmus, and ampulla, the myosalpinx architecture is represented by a unique muscular structure which runs from the mesosalpinx to the base of the inner mucous folds. This unique muscular structure consists mainly of bundles of muscular fibers independent of one another, which show a multiple spatial arrangement and form a complex network...
Steven DH, Jeffcott LB, Mallon KA, Ricketts SW, Rossdale PD, Samuel CA.Post-partum placentae and uterine biopsy samples from mares after normal and abnormal foalings are described. After normal delivery there is little damage to fetal or maternal tissues. The villous epitheliochorial palcenta separates cleanly at the maternal-fetal interface and the afterbirth consists almost exclusively of fetal tissue. Uterine involution is well advanced by the 3rd and 4th days post partum and the changes are usually complete by the oestrus 7--10 days after parturition. Placental separation and involution of the uterus appear to proceed normally in malpresented foals and in oth...
Mobarak MS, Ryan MF.The ultrastructure of the dorsal oesophageal gland ampulla and its relationship with the oesophagus, oesophageal ultrastructure, and control mechanisms in oesophageal activity were studied. Terminal ducts of the sub-ventral glands open through the oesophageal crown at the base of the buccal cavity. The terminal duct of the dorsal oesophageal gland running through the dorsal gutter opens to the exterior at the rim 'groove' of the buccal capsule. The posterior oesophageal region is clavate and the cuticle of the lumen folds to form outlet valves, 'valvulae'. An inconspicuous oesophago-intestinal...
Tangkawattana P, Karkoura A, Muto M, Yamano S, Taniyama H, Yamaguchi M.Numerous rod bodies were found in a heart sample from a 33-year-old pony by a conventional electron-microscopic technique. The rod bodies were concentrated in localized areas of both atria and ventricles, without a specific pattern of distribution. The rods appear to have a typical crystalline-like structure which presumably contains actin backbone filaments and alpha-actinin as major protein constituents. Diminution, fragmentation, and disorganization of the myofibrils, random expansion of electron-dense materials, especially at the fasciae adherens of the intercalated disc, an increase of in...
Lantz KC, Enders AC, Liu IK.In addition to the unique feature of retention of unfertilized ova, the oviducts of mares frequently contain large intraluminal masses with a fibrillar component and some cells. The aim of this study was to identify the cells and examine their relationship to the extracellular components of these masses. Intraluminal masses were examined both in situ and flushed from the oviducts. The nature of the contained cells and their relationship to the fibrils were examined by light microscopy and by transmission and scanning electron microscopy. In some mares the large masses distended the oviduct, bu...
Camacho CA, Estradé MJ, Cazales N, Caballeros JE, Fiala-Rechsteiner SM, Neves AP, Mattos RC.This experiment aimed to verify if the proteins present in a 13 day conceptus induce changes in the equine endometrial ultra-structure, histology, and vascularization, two days after its infusion. Ten healthy cyclic mares were used. Once estrus was confirmed, mares were examined daily to detect ovulation (day 0). After ovulation, mares were examined daily until day seven by transrectal palpation and B-mode and Doppler ultrasonography. In this first cycle, intrauterine biopsies were collected at day seven after ovulation, constituting the Cyclic group (n = 10). In the second cycle, the same mar...
Alm H, Neumann H, Torner H, Tomek W, Wollenhaupt K, Kanitz W, Becker F.Equine oocytes were collected by follicle aspiration in vivo or by dissection of material obtained from an abattoir, and the ultrastructure, protein phosphorylation and mRNA status of the oocytes were evaluated. Electron microscopy studies indicated that the nucleus had a smooth membrane in oocytes with a compact cumulus, whereas the nuclear membrane was undulated in all other groups. Oocytes with compact cumuli had only a few microvilli, whereas those with expanded cumuli had more microvilli. There were only small numbers of cortical granules close to the oolemma in oocytes with compact cumul...
Pfeiffer CJ, Murray MJ, Fainter L.The granular columnar epithelial cell of the equine dorsal large colon has been studied by transmission electron microscopy and X-ray microanalysis. Particular attention was focused on nuclear bodies commonly observed as central clusters of spherical, electron-dense inclusions within the nucleus. Ultrastructural morphology as well as X-ray microanalysis spectra reveal great similarity between colonic nuclear bodies and the numerous small granules of the apical cytoplasm in these epithelial cells. X-ray spectra of these cells were distinct from those of goblet cell mucous granules and mast cell...
Anthauer K, Mülling C, Budras KD.This study aimed to carry out a comprehensive morphological examination of the structure and ultrastructure of the membrane-coating granules (MCG) and membrane-coating material (MCM) common to all hoof segments as well as segment-specific features in the MCG and MCM regarding their synthesis, structure and biochemical composition. Tissue samples from the hooves of the left front and right hind limb of 20 adult riding horses were used. Samples were preserved and embedded for histological routine methods as well as for histochemical techniques and tracer techniques for light and electron microsc...
Hamada M, Itakura C.The morphology of hypomelanosis occurring in experimentally induced equine papillomas was investigated. Histologically, dopa-positive functioning melanocytes were decreased in number from the basal layer in the epidermis. Electron-microscopically, melanogenic organelles in the melanocytes were degenerate and melanosomes were decreased in number and size. In addition, the melanocytes had some abnormal melanosomes including melanosome complexes and giant melanosomes. Some abnormal melanosomes were also present in the keratinocytes. The hypomelanosis seemed to be related to a disturbance in melan...
