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Topic:Microscopy
Microscopy in equine research involves the use of various microscopic techniques to study the cellular and subcellular structures of horses. This field encompasses the examination of tissues, cells, and microorganisms to gain insights into equine health, disease mechanisms, and physiological processes. Techniques such as light microscopy, electron microscopy, and fluorescence microscopy are employed to observe and analyze samples at high magnification, providing detailed information on morphology and pathology. Microscopy aids in the diagnosis of diseases, identification of pathogens, and evaluation of cellular responses to treatments. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of microscopy in the study of equine biology and medicine.
Intimal asteroid bodies in horses: light and electron microscopic observations. 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...
Microtubular mass defect of spermatozoa in the stallion. A microtubular mass (MM) defect was found in the spermatozoa of 7 Standardbred stallions; 3 stallions were sons of the same sire. Two of these 3 stallions and 2 other stallions (for a total of 4 out of the 7 stallions) were considered subfertile when the defect was first observed. Fertility improved with time, either during the first breeding season or when a given stallion was used less frequently; however, the MM defect persisted, consisting of tortuous arrays of small abnormal microtubules visible only by transmission electron microscopy. The MM probably contained the protein tubulin as ind...
Cryptosporidiosis in two foals. Cryptosporidium oocysts were identified by phase contrast microscopy on smears from flotations of greenish-yellow pasty feces obtained from two foals. One foal, a one week old Percheron was recumbent, anorectic and lethargic, believed to be the result of a septicemia of undetermined etiology. Despite therapy and nursing care the animal died. Using light and electron microscopy, numerous stages of Cryptosporidium sp. were seen protruding from the surface of epithelial cells of intestinal villi. The other foal, a six week old Arabian had a mild diarrhea. The diarrhea and passage of oocysts event...
Morphology of three strains of contagious equine metritis organism. Examination of recently isolated cultures of three strains of Contagious Equine Metritis Organism grown on specially formulated, serum-free, clear typing medium revealed the presence of numerous colonial opacity variants. These colonies were prepared by a number of fixation and staining techniques and examined by scanning and transmission electron microscopy. Opaque and transparent phenotypes produced copious amounts of extracellular material compared with intermediate-opacity phenotypes which produced little or none. Also unique to intermediate colonies were numerous thin intercellular strand...
Flunixin meglumine attenuation of endotoxin-induced damage to the cardiopulmonary vascular endothelium of the pony. Endotoxic shock was induced in 5 ponies by intraperitoneal injections of 20, 40, 60, 80, and 80 micrograms of Escherichia coli endotoxin (LPS)/kg of body weight at 0, 6, 12, 18, and 24 hours, respectively. At 24 hours, the ponies also were given 20 micrograms of LPS/kg via catheter in the left ventricle of the heart. A 2nd group of 4 ponies was given 1.1 mg of flunixin meglumine (FM)/kg, IV, at 6, 12, 18, and 24 hours just before the corresponding LPS injection. Two hours after the 24-hour LPS injection, the ponies in both groups were anesthetized, the lungs were perfused with fixative, and po...
Uterine involution in mares treated with progesterone and estradiol-17 beta. Bacteriology, histology, and scanning electron microscopy were used to evaluate uterine involution in 27 mares treated with daily injections of 150 mg of progesterone and 10 mg of estradiol-17 beta, commencing within 18 hours of parturition. These findings were compared with those for 24 untreated mares at postpartum day 10 or 11. The treatment resulted in significantly (P less than 0.05) greater uterine gland proliferation. Gland density was significantly (P less than 0.05) greater in mares treated for 6 to 10 days than in those treated 2 to 5 days. The proportion of ciliated cells to secreto...
Steroidogenic characteristics of the adrenal cortex of the mare studied by electron microscopy. The three concentric zones of the horse adrenal cortex (zonae glomerulosa, fasciculata and reticularis) showed marked interpenetration and exhibited a different relative development according to their position in the gland. Whereas the three cortical zones each had a specific histological structure, the ultrastructure of their cells showed a certain qualitative homogeneity. The differences corresponded essentially to the relative abundance of the constituents which are generally considered typical of steroidogeneous cells: mitochondria with vesicular cristae, smooth endoplasmic reticulum and l...
Effects of repeated endotoxin injections on prostanoids, hemodynamics, endothelial cells, and survival in ponies. The objectives of this study were to determine the pathophysiological effects of increasing amounts of endotoxin administered intraperitoneally (IP) for 24 hr at which time an intravenous (IV) injection of endotoxin was given. The ability of flunixin meglumine (FM), a nonsteroidal antiinflammatory drug with antiprostaglandin activity, to provide protective effects was also determined. Eight ponies were divided into two groups of four ponies each; one group (untreated) received endotoxin only and the other group (treated) received endotoxin while being treated with flunixin. Hemodynamic and ser...
Topography and enterocyte morphology of the small bowel mucosal surface in equine granulomatous enteritis. The jejunal mucosa of 4 cases of equine granulomatous enteritis and 2 control horses was investigated by light microscopy and by scanning and transmission electron microscopy. Attention was focused upon changes in mucosal topography and enterocyte morphology in the inflamed mucosa. Structural changes ranged in severity from only a slight thickening and shortening of villi to the appearance of a virtually flat mucosa, upon which crypts opened directly or through shallow cavities encircled by collars of epithelial cells. Between these extremes, the mucosa showed a variety of patterns, all charac...
[Attachment of horse cecum Ciliata to plant fragments. Degradation of chloroplasts. Attachment of bacteria to cecal Ciliata]. Cecum microfauna association with different plant tissues was examined by scanning and transmission electron microscopy. The ciliates were attached to the damaged areas of the leaves and their highest concentrations were found on the epidermis and mesophyll tissues. The degradation of plant tissue was due to protozoal ingestion of the plant fragments. The morphology of ingested envacuolized chloroplasts changed rapidly, showing different stages of digestion inside the ciliate endoplasm. Intact chloroplasts were rarely observed but the grana of fragmented thylakoid membranes was often seen. The...
Qualitative detection of corticosteroids in equine biological fluids and the comparison of relative dexamethasone metabolite/dexamethasone concentration in equine urine by micro-liquid chromatography-mass spectrometry. Several important corticosteroids were qualitatively determined in the plasma and urine of horses by micro-liquid chromatography-mass spectrometry (micro-LC-MS). The sensitivity and specificity of micro-LC-MS are demonstrated as is the ability of micro-LC-MS to deal with endogenous interferences. In turn, the relative amount of dexamethasone and its major unconjugated metabolite were determined in equine urine by micro-LC-MS; the conclusions drawn are reported.
Electron microscopy of equine respiratory viruses in organ cultures of equine fetal respiratory tract epithelium. Organ cultures of equine fetal tracheal and nasal turbinate epithelium were inoculated with equine influenza virus-A1 (EIV-A1), equine herpesvirus-1 (EHV-1), or equine rhinovirus-1 (ERV-1). Infected organ cultures were processed for scanning and transmission electron microscopy at various intervals and were compared with noninfected controls. Organ cultures inoculated with ERV-1 appeared normal with the exception of rare island-like lesions in infected nasal turbinate. Virus particles were not seen in thin sections of organ cultures infected with ERV-1. The EHV-1 caused extensive loss of the e...
Dirofilariasis with arteriosclerosis in a horse. Arteriosclerosis caused by Dirofilaria immitis adult parasites was diagnosed in a 20-month-old Quarter horse stallion that died from cantharidin toxicosis. Microscopically, the pulmonary vascular changes were typical of those described as "proliferative endarteritis" in D immitis-infected dogs.
Equine hydatidosis: a new record for New Zealand. Cysts found in the liver of a horse which had never been out of New Zealand were used to infect two dogs which were slaughtered 35 days after infection. Large numbers of Echinococcus granulosus were recovered. These cestodes were compared with mature dog-sheep cestodes, using light and scanning electron microscopy and identified as the dog-horse strain of E.granulosus.
A congenital vascular naevus in a foal. This paper describes a case of a congenital vascular malformation in the skin of a colt. The lesion arose at the coronary border of the right hind leg. The microscopic structure of a biopsy suggested that the lesion, consisting of multiple foci of closely-packed convoluted small vessels in the dermis, represented a marked exaggeration of glomi which normally occur in considerable numbers in this region of the skin. On the basis of the clinical, macroscopic and histological findings, this lesion was considered to be an hamartoma, rather than a true tumour, and was therefore termed a congenital ...
The regulatory peptide system of the large bowel in equine grass sickness. In recent years, distinct changes in regulatory peptides have been found in a number of gastrointestinal diseases. Grass sickness is a fatal disease of horses for which the etiology has yet to be fully ascertained. In this study, the peptide-containing nerves and ganglionic and mucosal endocrine cells of the ileum, colon and rectum were investigated in horses with sub-acute or chronic grass sickness and compared with normal controls using immunocytochemistry, at both the light and electron microscopical levels, and radioimmunoassay. A substantial loss of both peptide-containing cells and nerve...
Seasonal variation of histomorphologic features of equine endometrium. The effect of seasonal morphologic variation of equine endometrium on histologic interpretation of periglandular fibrosis was investigated in 5 mares. Endometrial tissue was procured monthly and examined microscopically for the degree of periglandular fibrosis. A prognostic category for each mare was based on the mean number of fibrotic foci per linear field of 5.5 mm. It was found that seasonal changes reflected in endometrial glands and stroma influenced quantitative assessment of fibrosis. This occasionally resulted in a change in the assigned prognostic category. Marked nonseasonal variati...
Disposition of the manchette in the normal equine spermatid. Bielanski and Kaczmarski (1979) reported the presence of microtubules in the neck region of mature stallion spermatozoa. It was hypothesized that these microtubules are derived from the manchette (a microtubular organelle present during spermiogenesis). In order to test this hypothesis, testes from 15 mature stallions were collected, perfused with 2% phosphate-buffered glutaraldehyde, and prepared for transmission electron microscopy. Spermatozoa from the caudae epididymides of each stallion were prepared in a similar manner. Spermiogenesis was observed in general, and the presence of a microt...
The comparative pathology of equine cutaneous phycomycosis. Pythiosis (204 cases, 77%), basidiobolomycosis (48 cases, 18%), and conidiobolomycosis (14 cases, 5%) were diagnosed morphologically from 266 horses with phycomycosis. All lesions were cutaneous ulcerative granulomas and three horses with pythiosis had metastatic lesions in regional lymph nodes. Lesions of pythiosis contained characteristic yellow, coral-like coagula and had a fibrotic surface containing sinus tract openings. Basidiobolomycosis was characterized by infrequent small yellow coagula and a yellow line of fungal invasion beneath an edematous surface. Lesions of conidiobolomycosis h...
Pathology of maternal genital tract, placenta, and fetus in equine viral arteritis. Six pregnant mares were given equine viral arteritis virus intravenously. Tissues from genital tracts, placentae, and fetuses were examined by light and electron microscopy to study the mechanism of abortion. Four mares which died with acute disease had diffuse vacuolation of endometrial epithelium and systemic necrotizing vasculitis. Two of these mares had dead fetuses and two had live fetuses; virus was isolated from tissues of one live fetus. Placentae of mares dying from acute disease did not have lesions attributable to infection; virus was isolated from two of these placentae. One of the...
Dermal collagen degradation and phagocytosis. Occurrence in a horse with hyperextensible fragile skin. A 2-year-old female horse had large areas of hyperextensible, fragile skin that were interspersed with areas of normal skin. Affected skin tore easily and contained reduced amounts of dermal collagen. Collagen fibers were fragmented and disorganized, and in trichrome-stained sections, many fibers had abnormal red-stained centers. Electron microscopy showed that many collagen fibers had discrete foci of degradation in which the fibrils were fragmented, loosely packed, and widely separated by granular material. Collagen fibril fragments were present in secondary lysosomes in dermal fibroblasts, ...
Ultrastructural comparison of Oncovirinae (type C), Spumavirinae, and Lentivirinae: three subfamilies of Retroviridae found in farm animals. The successive steps of maturation of seven retroviruses from five species of farm animals and one retrovirus from a mouse were compared in cell cultures. The viruses included three type C oncoviruses, one spumavirus, and three lentiviruses. Although members of the 3 subfamilies shared some gross morphologic features such as budding on plasma membranes, core, and surface projections, differences were noted in the ultrastructural detail of these features. Type C oncoviruses did not show any structural differentiation in identifiable form in the cytoplasm as opposed to characteristic features ob...
Laser therapy in the horse: histopathologic response. Surgical incisions were made in the skin and superficial digital flexor tendons in horses. A low intensity laser therapy device was used to treat the limbs. After laser therapy was completed, skin and superficial digital flexor tendons from incised laser-irradiated, incised-control, and nonincised-control limbs were compared microscopically. Qualitative differences between laser irradiated and nonirradiated tissues were not found. The laser therapy device used in this study may be of insufficient power to affect wound healing.
Effect of monensin on the morphology of mitochondria in rodent and equine striated muscle. Heart, diaphragm, and rear limb muscle from ponies and rats treated with monensin were examined by light and electron microscopy. In both species, mitochondrial aberrations were observed in selected muscle cells. The aberrations consisted of loss of matrix substance (vacuolization) usually accompanied by swelling. Vacuolated mitochondria were characterized by an almost total loss of matrix substance with retention of the rudimentary cristae form. In ponies, most vacuolated mitochondria were observed in heart muscle though some also were found in the diaphragm. In rats, most vacuolated mitochon...
[Lateral motor nucleus in the lumbosacral segment of the spinal cord of the horse]. Two medullae oblongatae of horses were cut into 15 microns cross-sections and stained according to the modified method of Nissel. The lateral motor nucleus lies in the lateral and median part of the ventral column of spinal cord grey matter. It adjoins medially nucleus motorius medialis of the spinal ventral column. Cells of this nucleus occur both along the whole lumbar and sacral segment of the spinal cord. In the lateral motor nucleus three cell groups are distinguished - median, basal and lateral. The latter is divided in some segments into subgroups - dorsal and ventral. Along the nucleus...
Cholesteric organization of DNA in the stallion sperm head. The fine structure of chromatin in sperm heads was investigated by different microscopic techniques: in vivo examinations in the polarizing microscope, thin sections and freeze-fracture replicas observed by transmission electron microscopy. The freeze-fractured chromatin appears to be formed of superimposed lamellae, each one 330 A thick. These lamellae are parallel to the flattening plane of the sperm head. This situation was already described in other mammal spermatozoa and in particular in the bull and the rabbit. This work presents a new interpretation of this lamellated aspect. The chroma...
Borna disease of horses. An immunohistological and virological study of naturally infected animals. The brains of eight horses that had suffered from natural Borna disease were examined with virologic, immunohistological, and electron-microscopic methods. All brains harbored infectious virus as shown by inoculation of experimental animals. Regional assessment of the infectivity exhibited the highest titers in the hippocampus and piriform cortex and the lowest in the cerebellum. Conventional histology yielded pathologic alterations very similar to those of the classical description of the disease. Immunohistology demonstrated the highest amounts of Borna disease virus-specific antigen in the ...
Effectiveness of fenbendazole against later 4th-stage Strongylus vulgaris in ponies. Twelve pony foals (reared worm-free) were inoculated with Strongylus vulgaris. Approximately 8 weeks later, 4 of the foals were given fenbendazole (10% suspension) at a dosage rate of 10 mg/kg of body weight daily for 5 days and 4 foals were given the suspension at a dosage rate of 50 mg/kg daily for 3 days; the remaining foals were given a placebo. All treatments were administered by stomach tube. Fenbendazole was 99.6 and 97.9% effective in the 2 treatment groups, respectively, in eliminating later 4th-stage S vulgaris larvae located near the origin of major intestinal arteries. On microscop...
