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The purpose of the present study was to demonstrate the localization of transmembrane mucin MUC1 on the outer layer of oral mucosal cells and the involvement of apical cell surface microplicae (MPL) in bioadhesion of MUC1. Tissue samples of six healthy subjects were obtained. First, the presence of MUC1 was examined with an immunohistochemical method using a monoclonal MUC1 antigen called HFMG1. Second, the localization of MUC1 was examined with immuno-scanning electron microscopy. Immunohistochemically, high intense staining for MUC1 (antigen HFMG1) was detected in the epithelial superficial layers. In the superficial layer, intense MUC1 expression was seen predominantly on the apical cell surface. On the apical epithelial cells, MUC1 was associated predominantly with MPL towards the oral cavity. The novelty of the results of the present study is that MPL serves a harbor of MUC1 in superficial epithelial cells towards the oral cavity. It is speculated that the transmembrane MUC1 is one component of the "oral mucosal barrier complex" representing a signaling pathway between saliva and mucosal cells. Abbreviations: MUC1: mucin1; MAM: membrane-anchored mucin; OMBC: oral mucosal barrier complex; LM: light microscopy; TEM: transmission electron microscopy; SEM: scanning electron microscopy; iSEM: immuno-scanning electron microscopy; MPL: microplicae [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study is to investigate the morphological and cellular changes in dental extraction socket that has been irradiated after the tooth extraction and to describe morphological characteristics of the osteocytes and osteocyte-lacunar-canalicular network (LCN) by scanning electron microscopy (SEM).Material and methods: Five beagle dogs aged 1–2 years were used in this study. One side of each mandible was irradiated in two sessions and the other side of mandible (non-irradiated) served as a control. The mandible bone blocks were processed by bulk staining en bloc in basic fuchsin and the specimens were embedded routinely in polymethyl methacrylate resin without preliminary decalcification. All blocks were subjected to micro-CT imaging, after that the specimens were prepared for light microscopy and SEM.Results: Alterations in bone macrostructure are minimal in irradiated bone, but the changes in LCN are clear. In the area of the tooth extraction socket, the connections of osteocytes to the vessels and to neighboring osteocytes were not observed both in irradiated and nonirradiated bone. However, osteoclasts were located in the bone surface entering inside to the bone between osteons. In the lamellar bone of lateral sides, a decrease in canalicular connections between osteocytes and periosteum was found in irradiated bone as compared to the non-irradiated side.Conclusions: The novelty of the present study is that radiation disrupts osteocytes and their dendrites. [ABSTRACT FROM PUBLISHER]

The aim of this study was to define the acid-etching technique for bone samples embedded in polymethyl metacrylate (PMMA) in order to visualize the osteocyte lacuno-canalicular network (LCN) for scanning electron microscopy (SEM). Human jaw bone tissue samples (N = 18) were collected from the study population consisting of patients having received dental implant surgery. After collection, the bone samples were fixed in 70% ethanol and non-decalcified samples embedded routinely into polymethyl metacrylate (PMMA). The PMMA embedded specimens were acid-etched in either 9 or 37% phosphoric acid (PA) and prepared for SEM for further analysis. PMMA embedded bone specimens acid-etched by 9% PA concentration accomplishes the most informative and favorable visualization of the LCN to be observed by SEM. Etching of PMMA embedded specimens is recommendable to start with 30 s or 40 s etching duration in order to find the proper etching duration for the samples examined. Visualizing osteocytes and LCN provides a tool to study bone structure that reflects changes in bone metabolism and diseases related to bone tissue. By proper etching protocol of non-decalcified and using scanning electron microscope it is possible to visualize the morphology of osteocytes and the network supporting vitality of bone tissue. [ABSTRACT FROM PUBLISHER]

Background: Salivary mucosal pellicle forms the structural basis of the local innate immune defense mechanism of the oral mucosa. At the surface of the oral mucosa, the apical cell membrane adjacent to the saliva interface contains short membrane folds, termed microplicae (MPL). This MPL structure of oral epithelial cells and its function as a basis to the salivary mucosal pellicle is unclear. In this preliminary study, we describe the ultrastructural morphology of cell membrane of superficial cells of the oral mucosa and study the membrane-associated mucins (MAMs), MUC1 and MUC4, with immunohistological methods. Materials and methods: Oral mucosal specimens were obtained from six healthy patients. Half of each specimen was prepared routinely for light microscopy, and the other part for scanning and transmission electron microscopy. The presence of MUC1 and MUC4 were studied by immunohistochemical methods in oral mucosal specimens. Results: Morphologically, the cell membrane of MPL is partly discontinuous and membrane-associated molecules extrude from the cell membrane. MUC1 expression was detected in the superficial part of the buccal epithelium, while MUC4 had no expression in the oral squamous epithelium. Conclusions: The novel of this study is that the membrane-tethered molecules seem to occur onto the cell membrane of the superficial epithelial cells of the oral mucosa. Furthermore, the stratified squamous epithelium of the buccal mucosa produces MUC1 for the surface-saliva pellicle interface. The interaction between MPL structure, MUC1 mucin, and salivary mucosal pellicle is discussed. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study is to investigate if radiation induces changes in the superficial cells of the oral mucosa and secondly to describe morphological characteristics of the cell surface structure by scanning electron microscopy (SEM). Materials and methods: Ten beagle dogs aged 1-2 years were used in this study. One side of each mandible was irradiated in two sessions, each lasting 1 week. The total dosage was 40 Gy (Group A; 5 dogs) and 50 Gy (Group B; 5 dogs), in five fractions of 4 Gy. The other side of mandible (non-irradiated) served as a control. The specimen was harvested with a scalpel from the alveolar mucosa of the irradiated area 1 year after irradiation and studied with SEM. Results: In the control side, the surface structure of the cell contains straight parallel or branched microplicae (MPL), which were equally spaced over the cell surfaces. Discontinuous and short MPL were typical cell structure of irradiated mucosa. In 50 Gy group, the surface structure of epithelial cell was pitted and the cell boundaries were thick. Conclusions: The novelty of the present study is that radiation disrupts superficial cells of the oral mucosa. The role of the MPL structure of the superficial cells in mucositis development is discussed. [ABSTRACT FROM AUTHOR]