Scanning electron microscopy of the bovine, equine, porcine, and caprine uterine tube (oviduct).

The luminal surface topography of bovine, equine, porcine, and caprine uterine tubes was studied by scanning electron microscopy. The main types of epithelial cells were secretory and ciliated. Both types were more active during estrus. Cilia were observed in both the infundibular and the ampular parts of the uterine tube, but ciliated cells were more numerous than secretory cells on the surface of the fimbriae. Sperm were observed in the ampulla of the uterine tube of the cow 2 hours after artificial insemination.     

Scanning electron microscopy of nerve sheath neoplasms

Neurofibromas and schwannomas were clearly differentiable by scanning electron microscopy of thin microscopic sections. Neurofibromas exhibited ordered laminations of collagen with scattered fibroblast-like cells interspersed. Schwannomas contained proliferations of smooth tube-forming cells. These neoplastic characteristics were compared with cellular characteristics of normal nerve sheaths to determine the cell of origin in each neoplasm.     

Scanning electron microscopy of sarcoptic mange lesions in swine

Scanning electron microscopy revealed that lesions of sarcoptic mange in swine, pass through 3 different stages. During the first 3 weeks of infestation, adult female mites tunnel into the epidermis. During the following 3 or 4 weeks, the surface openings of these tunnels become covered with keratinized epidermal crust which increases in thickness. After 7 weeks of infestation, the crust falls off, the tunnel openings become apparent again and most of the mites vacate these tunnels.     

Scanning electron microscopy of the canine atrioventricular bundle and moderator band

The atrioventricular (AV) bundle and the moderator band in the canine heart were examined by scanning electron microscopy. The AV bundle and the moderator band both were comprised of large, cylindrically shaped cells. These cells were highly organized into bundles, with minimal lateral communication between bundles. There was extensive cell-to-cell communication between cells within a bundle. The end branching of individual cells was prominent, with some interbundle communication. These results are discussed in relationship to the electrophysiologic properties of the AV bundle and the conduction velocity.     

Scanning electron microscopy of the lesions of swine dysentery.

Thirty weanling pigs were examined by scanning electron microscopy at various time intervals after oral inoculation with crude colon contents from pigs affected with dysentery. The earliest recognizable change was a corrugated appearance of the mucosal surface of the large intestine. Large spirochetes, morphologically similar to Treponema hyodysenteriae, were first observed within the crypts of Lieberkühn where they seemed to proliferate onto the luminal surface. Then mucus, fibrin, erythrocytes, and disrupted epithelium appeared. Large spirochetes were always abundant in those lesions, but variable numbers of other mixed bacterial forms were also present. The earliest changes could be correlated with the appearance of large spirochetes in the feces and with early clinical signs, but not with a specific postinoculation time. Once bloody diarrhea was present, no consistent pattern was observed in development, location, or form of the lesions. With time, the lesions merely came to involve an increasingly greater surface area of the large intestine.     

Scanning electron microscopy of Heinz bodies in feline erythrocytes.

Whole blood and partially lysed blood films from 5 cats having 20 to 91% of the erythrocytes containing Heinz bodies were examined, using the light microscope and the scanning electron microscope. Heinz bodies were detected in the intact erythrocytes from 3 of the cats as abruptly elevated and distinctly demarcated protuberances in various shapes, sizes, and locations. The Heinz bodies were located just beneath the cell membrane either centrally or near the cell margin and varied in their projectional magnitude. Brilliant cresyl blue staining of blood of these 3 cats revealed prominent Heinz bodies within, and projecting from, the erythrocytes. In contrast, Heinz bodies were not identified on scanning electron microscopy of intact erythrocytes of the remaining 2 cats even though Heinz bodies were found on their blood films stained with brilliant cresyl blue. Scanning electron microscopy of partially lysed blood smears of all 5 cats revealed Heinz bodies of various sizes in the erythrocyte ghosts. Furthermore, blood smears from the 3 cats having distinct Heinz bodies in intact erythrocytes revealed small dense intracellular granules distributed singly or coalesced in small clumps. Further aggregation of these clumps was assumed to result in the formation of a single large Heinz body. The 3-dimensional nature of Heinz bodies was clearly apparent in lysed blood smears.     

Scanning electron microscopy of the cecal mucosa in Eimeria-tenella-infected and uninfected chickens.

Four major types of surface conformation were observed in the ceca of uninoculated control chickens. Spatulate villi were found in the cecal neck region, low ridges in the region where the neck expands, protruding collarlike structures in the mid cecal pouch, and flattened collars in the distal portion. In ceca infected with Eimeria tenella, there was some erosion and sloughing of the mucosal cells. These lesions were slight in the neck region, more severe in the dilated portion, most severe in the midregion, and moderate in the distal area. Oocysts were observed in the mucosal tissue of the cecal pouch.     

Scanning electron microscopy of root resorption of feline teeth

Scanning electron microscopy was carried out on 10 feline extracted permanent teeth from 3 cases with root resorption. Various-sized resorption lacunae were well defined, showing an etched pattern and configuration as shown in human deciduous teeth. In cats, regardless of the shape and depth of lacunae, the resorption lacunae showed opening dentinal tubules in the wall with or without cement matrix apperring only in the deep and round lacunae of human cases. Some specific process of mineralization for repairing dental root resorption was suggested in cats.     

Scanning electron microscopy of circulating primordial germ cells in the chick embryo

A demonstration of circulating primordial germ cells in the stage 14 embryo was carried out. The definition of primordial cells was based upon specific criteria utilized by other workers and developed in this study. Evidence supports a passive transport of these cells to the germinal epithelium.     

Scanning electron and light microscopy of the mucosa of the equine ileocaecal junction

The ileocaecal junction mucosal surface morphology of 5 horses and 1 donkey was examined using scanning electron microscopy and light microscopy. Based on differences in surface morphology, the junction could be divided into 4 distinct regions. The distal extremity of the ileum was characterized by the presence of typical finger-like villi followed by a narrow zone displaying short, stubby villi which gradually merged into a 3rd region representing the true transitional zone between the small and large intestine. In this region the villi fused, forming low ridges arranged in circular, semi-circular or S-shaped patterns. Many of the fused villi were indented at the tips giving these structures a doughnut-like appearance. The caecal portion of the ileocaecal junction formed the 4th region and was characterized by the absence of villi and the occurrence of regularly spaced crypt openings each surrounded by a slightly raised circular mound.