Aracy Akiko Motoyama

Scanning electron microscopy study of the interface epithelium-connective tissue surface of the lingual mucosa in Calomys callosus

The characteristics of the interface epithelium-connective tissue of the lingual mucosa of Calomys callosus was studied by employing scanning electron microscopy after removal of the epithelial cells. In the anterior part, the connective tissue papillae of filiform papillae are distributed at random in their original configuration, and the round-shaped fungiform papillae are scattered among the filiform papillae. In the middle part, the filiform papillae present several rod-shaped projections. In the posterior part, the vallate papilla are oval in shape, and the connective tissue reveals a large ridge separated by deep lateral grooves. The posterior adjacent area is a flat surface and shows several openings of salivary gland ducts. The foliate papillae are formed by several small ridges separated by grooves. In the areas adjacent to the foliate papilla, small pointed and laminar papillae were observed.

Ultrastructural characteristics of the gerbil pterygoid medial muscle after experimental occlusal alteration

Ten male young adult gerbils Meriones unguiculatus weighing 55g were divided in two groups: experimental (n=5) animals submitted to exodontia of the left upper molars, and sham-operated were used as control (n=5) group. The aim of the present study was to investigate the ultrastructural effects of occlusal alteration induced by unilateral exodontia on medial pterygoid muscle. After 60 days, the animals were sacrificed by perfusion intracardially with a modified Karnovsky solution after anesthetized with overdose of urethane (3g/kg i.p.). The small samples of this muscle were fixed in 2.5% glutaraldehyde solution and post-fixed in 1% buffered osmium tetroxide solution, dehydrated in ascending concentration of ethanol, and embedded in Spurr resin. Several micrographs data showed that in this period of time, the unilateral teeth extraction was able to induce modifications on the medial pterygoid muscle fibers and capillaries at ultrastructural levels as compared to control muscles and to the ones in the contralateral side of the experimental animals. Ultrastructural changes suggest that injury was greater in the hypofunctional muscle, ipsilateral to teeth extraction.

Ultrastructure of motor nerve terminals in the anterior third of Wistar rat tongue.

The nerve terminals of intrinsic muscular fibers of the tongue of adult wistar rats was studied by using silver impregnation techniques, transmission electron microscopy (TEM), and high resolution scanning electron microscopy (HRSEM) to observe the nerve fibers and their terminals. Silver impregnation was done according to Winkelman and Schmit, 1957 . For TEM, small blocks were fixed in modified Karnovsky solution, postfixed in 1% buffered osmium tetroxide solution, and embedded in Spurr resin. For HRSEM, the parts were fixed in 2% osmium tetroxide solution with 1/15 M sodium phosphate buffer (pH 7.4) at 4°C for 2 h, according to the technique described by Tanaka, 1989 . Thick myelinated nerve bundles were histologically observed among the muscular fibers. The intrafusal nerve fiber presented a tortuous pathway with punctiform terminal axons in clusters contacting the surface of sarcolemma. Several myelinated nerve fibers involved by collagen fibers of the endoneurium were observed in HRSEM in three‐dimensional aspects. The concentric lamellae of the myelin sheath and the axoplasm containing neurofilaments interspersed among the mitochondria were also noted. In TEM, myofibrils, mitochondria, rough endoplasmic reticulum, Golgis apparatus, and glycogen granules were observed in sarcoplasm. It is also noted that the sarcomeres constituted by myofilaments with their A, I, and H bands and the electron dense Z lines. In areas adjacent to muscular fibers, there were myelinated and unmyelinated nerve fibers involved by endoneurium and perineurium. In the region of the neuromuscular junction, the contact with the sarcolemma of the muscular cell occurs forming several terminal buttons and showing numerous evaginations of the cell membrane. In the terminal button, mitochondria and numerous synaptic vesicles were observed. Microsc. Res. Tech., 2009.

Ultrastructure of the adhesion of bacteria to the epithelial cell membrane of three-day postnatal rat tongue mucosa: a transmission and high-resolution scanning electron microscopic study

Togue mucosa surface of 3-day postnatal rats was examined under transmission electron microscopy (TEM) and high-resolution scanning electron microscopy (HRSEM). For HRSEM analysis, the specimens were fixed in the same solution for 24 h, postfixed in 2% osmiun tetroxide, critical-point dried and coated with platinum-palladium. For TEM analysis, the specimens were fixed using modified Karnovsky solution and embedded in Spurr resin. The results revealed the presence of numerous microplicae in the membrane surface of keratinized epithelial cells to which groups of bacteria were attached. These bacteria were staphylococcus and coccus organized either in rows or at random, which were visualized in three-dimensional HRSEM images. At high magnification, the TEM images revealed the adhesion of bacteria to the cell membrane through numerous filamentous structures comprising the glycocalyx. The fine fibrillar structures rising from each bacterium and from cell membrane were clearly seen. These characteristics on bacteria structure may be used for future control or prevention of bacterial diseases and for installation of the oral native flora.

Ultrastructure of the Myelinated and Unmyelinated Nerve Fibers of the Tongue Mucosa of Albinus Rat (Wistar) with Aging

El objetivo de esta investigacion fue estudiar las fibras sensitivas mielinizadas y amielinicas localizadas en la lamina propia subepitelial de la mucosa lingual de ratas. Se uso el metodo de impregnacion argentica, microscopia MET y mediciones morfometricas. Los resultados revelaron que los fasciculos de fibras subepiteliales de las regiones anterior, media y posterior de la lengua provenian de su capa muscular profunda. Los grupos de fibras fueron localizados dentro del tejido conectivo de la lamina propia. Estas fibras nerviosas se ramificaron varias veces y en el tejido conectivo de las papilas formaron terminaciones simples o ramificados. Las papilas fungiformes y valadas contenian numerosas terminaciones nerviosas. La ultraestructura demostro en el axoplasma la presencia de neurofilamentos, mitocondrias y microtubulos; aunque los registros morfometricos de las fibras mielinizadas mostraron que alrededor del 44% tenian un diametro entre 3 y 4 µm, el valor promedio fue de 4.5 µm. El diametro mayor fue de 12 µm y el menor de 1.4 um. Los rangos de menores diametros fueron de 1 a 3 µm, siendo el promedio de 2.33 µm. En relacion al espesor de las vainas de mielina, los valores obtenidos fueron de 0.2 a 0.8 um siendo el valor promedio de alrededor de 0,5 µm, en el 90% de ellas. En las fibras amielinicas los mayores diametros (62%) variaron entre 0.25 y 0.75 µm. El valor promedio fue de 0.6 µm, siendo el valor maximo 3.17 µm y el minimo 0.2 µm. El menor diametro fue obtenido en 44% de las fibras amielinicas y los rangos variaron entre 0.2 y 0.4 µm. El valor maximo obtenido fue de 1 µm y el minimo 0.12 µm

HIGH RESOLUTION SEM OF INTRINSIC MUSCLE FIBERS OF ANTERIOR THIRD RET'S TONGUE

SUMMARY: Las caracteristicas de las fibras musculares del tercio anterior de la lengua de la rata adulta fueron estudiadas em- pleando microscopio de luz, MEB y metodos de alta resolucion de MEB (ARMEB). Para la miscroscopia de luz, los especimenes fueron fijados en solucion de Bouin e incluidos en parafina. Con el proposito de identificar las fibras musculares y los haces de fibras colagenas, cortes frontales fueron tenidos con hematoxilia-eosina, azo-carmin y picro-sirius. Los resultados mostraron que las fibras musculares cerca de la lamina propia estan fijos con tejido conectivo, constituyendo varios grupos. Los haces de fibras musculares estan dispuestos en direcciones longitudinal, vertical y transversal. Para la MEB, los especimenes fueron fijados en solucion de Karnovsky modificada y fracturadas en frio en nitrogeno liquido revelandose las fibras colagenas y fasciculos de fibras musculares dispuestas en tres dimensiones. Las muestras tratadas en solucion de NaOH mostraron la original localizacion de las fibras colagenass, constituyendo complejas redes en imagenes tridimensionales de MEB. A traves de ARMEB, los especimenes fracturados en DMSO revelaron la membrana basal de la celula muscular conteniendo estructuras tipo esponja y finas redes de fibras colagenas. Organelos citoplasmaticos, tales como mitocondrias con sus crestas y reticulo sarcoplasmatico, fueron claramente observados en imagenes tridimensionales con ARMEB