Marcia Consentino Kronka

Corrosion casts of young rabbit palatine mucosa angioarchitecture.

The microvascular system arrangement of the palatine mucosa in young rabbits was studied using vascular corrosion casts. Specimens were obtained by injecting low viscosity resin. Superficial microvessels were observed mainly by scanning electron microscopy (SEM). The blood microvessels showed differing features in the areas considered palatine rugae, inter-rugal areas and posterior region of the palatine raphe. Larger vessels were noted in deeper layers. Several capillary loops were distributed all over the palatine rugal surface. In spite of being a young animal, the rabbits palatine mucosa demonstrated a complex angioarchitecture.

Coronal dentinal tubules of non-erupted deciduous incisors

The diameter and density of coronal dentinal tubules were assessed in non-erupted human deciduous incisors. Using liquid nitrogen, frozen samples were fractured in longitudinal and oblique directions and observed by means of a Jeol JSM-6100 scanning electron microscope. It was observed that the diameter of dentinal tubules ranged from 0.50 to 1.94 micrometers and increased significantly from the outer to the inner layers. However, comparing the incisal, middle and cervical thirds, no statistically significant differences were observed. The number of tubules per square millimeter varied from 3,281 to 32,313 and also increased from the external dentinal surface to the dentinal surface of the pulp chamber.

Angioarchitectural characteristics of the anterodorsal surface of aging and young rabbit tongue: scanning electron microscopy study

The three-dimensional angioarchitecture of young and aging rabbit tongues were studied using a vascular corrosion cast method. The vascular network of different lingual papillae were observed by scanning electron microscope (SEM). Young animals showed filiform papillae distributed all over considered area, with fungiform ones among them. In comparison to developed specimens, young rabbits demonstrated dense and higher organization of microvascular network.

Fine structure of the 7 postnatal days Calomys callosus palatine salivary glands

The aim of this study has been to determine the ultrastructural characteristics of the minor palatine salivary glands on the seventh day of development and to demonstrate wether their secretion is mucous, serous or seromucous by light, transmission and scanning electron microscopy. This study has shown that the palatine gland acinar cells are predominantly mucous with some serous units. These cells contain electron dense (serous) and low electron dense (mucous) granules in the apical portions. The cytoplasmatic organelles like mitochondria, Golgi apparatus and rough endoplasmic reticulum are localized in a supranuclear portion. We could also observe the flattened myoepithelial cells surrounding the basal part of the acini with myofilaments, Golgi apparatus and mitochondria. Desmosomal junctions and membrane interdigitations are present between the acinar and the myoepithelial cells. A basal lamina, divided in two layers, an electron dense and an electron lucent is present between the glandular stroma which is composed of dense connective tissue and the endpieces.

PALATINE MUCOSA ANGIOARCHITECTURE STUDY OF YOUNG RABBITS USING SCANNING ELECTRON MICROSCOPY

Pocos trabajos han relatado la angioarquitectura de animales jovenes. Este estudio contribuye con las investigaciones acerca de la distribucion tridimensional de la mucosa palatina en conejos jovenes usando MEB. La corrosion vascular del molde fue obtenida usando resina de baja densidad - Mercox® CL-2B. No pudimos observar redes especificas en la cupula de los pliegues palatinos, en los interpliegues y mucosa labial. Fueron observados solamente loops capilares y pliegues transversos palatinos

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

Palatine mucosa of aging and experimentally induced diabetic aging rabbits : Light-microscopic, scanning electron microscopic and transmission electron microscopic qualitative study

Background: Data associating palatine mucosa, microvascular architecture, aging and diabetes mellitus are few, so the aim of the present study was to examine these conditions structurally and ultrastructurally. Methods: We used 18 female rabbits, aged about 2 years at the beginning of the experiment, distributed into 2 groups: aging diabetic and aging animals, prepared by three different methodologies: light microscopy, scanning electron microscopy and transmission electron microscopy. The samples were stained with hematoxylin-eosin for light microscopy, and for scanning electron microscopy, we used Mercox® Cl-2B vascular corrosion casts. For transmission electron microscopy, the specimens were fixed and embedded in Epon 812 resin. Results: Under light microscopy, we noted small amounts of underdeveloped connective papillae and significant flattened areas through the epithelium-connective tissue interface in the aging diabetic group. Larger blood vessels were deeply located in the palatine mucosa, branching off in the direction of the epithelium-connective tissue interface. Capillaries followed the interface contour. In both groups, vascular corrosion casts revealed capillaries sprouting out in disorganized rows but parallel between themselves. ‘Hair-pin’ capillary loops and convoluted capillary loops were noted. Conclusion: The aging diabetic group showed rarefying microvasculature areas with complex tortuous capillary loops. Transmission electron microscopy results showed that the aging diabetic group presented small cytoplasmatic projections directed to the vessel lumen and micropinocytic vesicle, i.e. caveolas. Epithelium-connective tissue interface, connective papillae, microangioarchitecture, and information about endothelial cells alterations were observed in the aging diabetic and aging animals.

Sensory nerve endings in the rat cheek mucosa: an electron microscopic study

As terminacoes nervosas sensitivas da mucosa da bochecha de ratos foram estudadas utilizando-se microscopia eletronica de transmissao. As amostras foram fixadas em solucao de Karnovsky modificada e inclusas em resina do tipo Epon. As terminacaos nervosas sensitivas mostraram um axonio central terminal contendo numerosas mitocondiras, neurofilamentos, microtubulos e vesiculas claras. A porcao proximal dos corpusculos revelaram projecoes citoplasmaticas de celulas lamelares e celulas perineurais. Delgados feixes de fibras colagenas foram identificados nos espacos interlamelares e na regiao externa dos corpusculos. Numerosas lamelas concentricas apresentavam caveolas, espacos interlamelares preenchidos por material amorfo, desmossomos do tipo juncional entre lamelas adjacentes e celulas lamelares internas e membrana axolplasmatica. Essas estruturas delgadas mostram-se importantes na identificacao e estudo das caracteristicas da mucosa oral.