Epithelial membrane antigen and DOG1 expression in minor salivary gland tumours.

Epithelial membrane antigen (EMA) and DOG1 are used as marker of epithelial cells, particularly the luminal cells, of salivary gland tumours. The aim of this study was to compare the EMA and DOG1 expression in tumours of minor salivary glands. Cases of pleomorphic adenoma (PA), basal cell adenoma (BCA), canalicular adenoma (CA), adenoid cystic carcinoma (ACC), polymorphous adenocarcinoma (PAC), mucoepidermoid carcinoma (MEC) and epithelial-myoepithelial carcinoma (EMC) were submitted to immunohistochemistry for EMA and DOG1. In PA and BCA, EMA and DOG1 were observed in luminal cells, while in CA the tumour cells were negative for both proteins. The EMA and DOG1 pattern expression detected in EMC was similar to that one observed in benign tumours. In ACC, both myoepithelial e epithelial expressed EMA and DOG-1. PAC tumour cells were only positive for DOG1, whereas MEC were only positive for EMA. In conclusion, EMA and DOG1 expression in benign salivary gland tumours was similar to normal salivary gland tissue and can be used as good marker of tumoral cells derived from intercalated ducts or its progenitor cells, while in malignant salivary gland tumours EMA expression is, however, better used as an indicator of aggressive behavior than a marker of luminal cells.

Immunolocalization of Surfactant Proteins SP-A, SP-B, SP-C, and SP-D in Infantile Labial Glands and Mucosa.

Surfactant proteins in different glandular structures of the oral cavity display antimicrobial activity for protection of invading microorganisms. Moreover, they are involved in lowering liquid tension in fluids and facilitate secretion flows. Numerous investigations for studying the occurrence of surfactant proteins in glandular tissues were performed using different methods. In the oral cavity, minor salivary glands secrete saliva continuously for the maintenance of a healthy oral environment. For the first time, we could show that infantile labial glands show expression of the surfactant proteins (SP) SP-A, SP-B, SP-C, and SP-D in acinar cells and the duct system in different intensities. The stratified squamous epithelium of the oral mucosa revealed positive staining for SPs in various cell layers.

A pathological study of the tongues of rabid dogs in the Philippines.

During rabies virus infections, the minor salivary glands are one of the important organs for virus replication and excretion into the oral cavity. However, details of pathological findings and viral antigen distribution in the minor salivary glands remain poorly understood. In this study, we conducted pathological tests on the tongues of 71 rabid dogs in the Philippines; the minor salivary glands (von Ebner's glands, lingual glands), circumvallate papilla, autonomic ganglia, and skeletal muscles were evaluated. Inflammatory changes were observed in the von Ebner's glands of 20/71 dogs, in the circumvallate papilla of 10/71, and in the tongue muscle of 1/71. Conversely, no morphological changes were observed in the lingual glands and autonomic ganglia. Viral antigens were detected via immunohistochemistry-based methods in the cytoplasm of the acinar epithelium in the von Ebner's glands of all 71 dogs. Virus particles were confirmed in the intercellular canaliculi and acinar lumen via electron microscopy. In the autonomic ganglia, viral antigens were detected in 67/71 rabid dogs. Viral antigens were detected in the taste buds of all 71 dogs, and were distributed mainly in type II and III taste bud cells. In tongue muscle fibers, viral antigens were detected in 11/71 dogs. No virus antigens were detected in lingual glands. These findings suggest that rabies virus descends in the tongue along the glossopharyngeal nerve after proliferation in the brain, and von Ebner's glands and taste buds are one of the portals of virus excretion into the saliva in rabid dogs.

Papillary architecture of the lingual surface in the puma (Puma concolor).

This research presents the first anatomical description of the tongue and lingual papillae of the mountain lion (puma). The tongues of three adult male pumas were used in this study. The tongues were dissected and studied firstly by gross and stereomicroscopy. Samples of each part were processed by study with scanning electron microscopy. The margins of the lingual apex were surrounded by numerous filiform papillae, which had a bulky papillary body and a bifurcated tip. On the dorsal surface of the lingual apex, filiform papillae were remarkably pointed and had many secondary projections, which emerged from the base of the main papilla. In the rostral half of the lingual body, filiform papillae were longer, cylindrical and had blunt tips. On the caudal half of the lingual body, filiform papillae gave place to conical ones exhibiting a pointed tip. The fungiform papillae were scattered on the whole dorsal surface of the tongue. On each lateral half of the tongue, four circumvallate papillae were observed and each circumvallate papilla was surrounded by thick and horseshoe-like annular pad, which were composed by pointed conical papillae on the caudal border of the lingual body. The dorsal surface of the circumvallate papilla was covered by many finger-like protrusion, and the tip of each protrusion had a central orifice. Anatomical distribution of lingual papillae was different to other carnivores and represents the adaptation to the feeding habits of this mammal. General morphology of the lingual structures was similar to those of the tiger.

Mucoepidermoid carcinoma of the posterior-lateral border of tongue: a rare presentation.

Mucoepidermoid carcinoma (MEC) is the most common malignant tumour of the major and minor salivary glands. Minor salivary glands are scattered in different areas of the oral cavity such as palate, retromolar area, floor of the mouth, buccal mucosa, lips and tongue, but so far, only a few lingual MEC cases have been documented in the literature and most of the studies have shown a predilection for base and dorsum of the tongue. We report a rare case of MEC involving the posterior-lateral border of the tongue.

Anatomical and Scanning Electron Microscopic Study of the Tongue in the Meerkat (Suricata suricatta, Schreber, 1776).

This research presents the first anatomical description of the tongue and lingual papillae of the meerkat and compares the different information on the morphology of the other carnivore species. For this purpose, three tongues were used as material. The tongue was elongated with an oval or rounded apex. On the dorsal and ventrolateral surfaces of the tongue, filiform papillae had extent variations in morphology. Papillary body of each filiform papilla on the ventrolateral surface of the lingual body was ramified into 2-5 glovelike projections, and all pointed tips of these projections were directed caudally. On the dorsal lingual surface, each filiform papilla leaned on another without any space and both lateral borders of each filiform papilla included 4-6 small secondary projections or spines. A few rounded fungiform papillae were randomly distributed and embedded among the filiform papillae. On the caudal one-third of the body, there were two elongated circumvallate papillae. Some superficial fissures and taste pores were detected on the flat surfaces of each circumvallate papilla which was surrounded by a prominent and continuous gustatory groove. On the radix of the tongue, numerous dome-shaped protuberances of lingual salivary glands beneath the epithelium and one centrally located orificium was very invincible on the convex surface of each protuberance. Anatomical distribution of lingual papillae differed from those of other carnivores and represented morphological adaptation to the food type and feeding habits.

Morphologic diversity of the minor salivary glands of the rat: fertile ground for studies in gene function and proteomics.

In this article the locations and histologic and ultrastructural features of all of the minor salivary glands of the rat are presented; similarities and differences among them are highlighted. These glands are almost as diverse morphologically as the major salivary glands of the rat. The acini of von Ebner's glands are serous; those of the anterior and posterior buccal glands and minor sublingual glands are mucous; and those of the glossopalatal, palatal, and Weber's glands are mucous with serous demilunes. The anterior buccal, minor sublingual and von Ebner's glands have striated and stratified columnar ducts, while only the minor sublingual and von Ebner's glands have intercalated ducts. The glossopalatal, palatal, posterior buccal and Weber's glands have none of these ducts; the tubulo-acini drain abruptly into short terminal ducts composed of stratified squamous epithelium. All of the mucous acini react with an antibody to a mucin (Muc19) of the rat major sublingual gland, but in some of the glands the reaction varies in intensity among the acinar cells. Ultrastructurally, the mucous secretory granules of the anterior buccal, glossopalatal, palatal and Weber's glands are biphasic, while those of the minor sublingual and posterior buccal glands are monophasic. Although there is a considerable body of literature concerning the development, innervation, physiology and proteomics of von Ebner's glands, investigation of the other minor salivary glands of the rat ranges from modest to nearly nonexistent.

Electron microscopic immunogold localization of salivary mucin MUC5B in human buccal and palatal glands.

In recent years, minor salivary glands, due to their involvement in the health and homeostasis of the oral cavity, have been the focus of several research investigations. Despite the fact that a considerable amount of data has been collected, many aspects of their functional features, including the secretory components they produce, remain to be ascertained. In this study we have analyzed the ultrastructural distribution of the MUC5B mucin in human palatal and buccal glands by means of post-embedding immunoelectron microscopy. Thin sections of normal human buccal and palatal glands obtained at surgery, were treated with polyclonal antibodies to human salivary MUC5B. Intense MUC5B reactivity was observed in the secretory granules of mucous cells of all glands examined. The present results provide new data regarding the secretory pattern of MUC5B in human buccal and palatal glands, indicating their significant contribution to the maintenance of the mucous biofilm that protects buccal and palatal mucosal areas.

Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands.

As a result of their presence throughout the mouth in the submucosa or between muscle fibers, minor salivary glands secrete directly and continuously into the oral cavity, providing mucosal surfaces with highly glycosylated proteins that are active in bacterial aggregation and in oral tissue lubrication. In this study, we investigated the ultrastructural localization of the MUC5B and MUC7 mucins in human labial glands by means of a postembedding immunogold technique. Thin sections of normal human labial glands, obtained during surgery, were incubated with polyclonal antibodies to human salivary mucins MUC5B and MUC7, and then with gold-labeled secondary antibodies. Specific MUC5B reactivity was found in the secretory granules of mucous cells of all glands examined, and was associated with the luminal membrane of duct cells. MUC7 labeling was observed in the granules of both mucous and seromucous secretory cells of the glandular parenchyma. Quantitative analyses demonstrated that seromucous granules have higher immunogold labeling densities for MUC7 than mucous granules. Our immunohistochemical data extend the results of previous light microscopic studies of MUC5B and MUC7 localizations, pointing out the significant contribution of human labial glands in the secretion process of these two mucins.

Ultrastructure and lectin cytochemistry of secretory cells in lingual glands of the Japanese quail (Coturnix coturnix japonica).

In the present study, as continuation of our previous research, Japanese quail (Coturnix coturnix japonica) lingual glands were investigated by means of transmission electron microscopy (TEM) to understand the cytoarchitecture and the subcellular sugar distribution within the different secretory structures. Indeed, glycosidic residues were visualized by applying an indirect technique of binding and the terminal sialoglycoconjugate sequences were characterized by employing sialidase digestion combined with lectin affinity. The ultrastructural analysis revealed an unusual cytoarchitecture of the caudal portion of anterior lingual gland that was composed of both secretory cells, filled with granules, and non-secretory cells, filled with mitochondria. Conversely, the posterior lingual gland was composed of secretory units of lingual glands only containing mucous cells filled with secretory granules with a variable morphology, including bipartite features characterized by an electron-lucent matrix and one or more electron-dense areas. Actual findings further supported that the quail lingual glands produce sialoglycoconjugates characterized by a heterogeneous composition. In conclusion, the cytological characteristics and the carbohydrate composition of quail lingual glands suggest that, analogously to mammal salivary glands, avian lingual glands could also be involved in several functions that can be correlated with the occurrence of sialic acids.

Ultrastructural changes of posterior lingual glands after hypoglossal denervation in hamsters.

Posterior lingual glands consist of two sets of minor salivary glands that serve important functions in oral physiology. To investigate the hypothesis that the hypoglossal nerve provides sympathetic innervation to the posterior lingual glands, we examined ultrastructural changes in the glands following hypoglossal denervation. In the posterior deep lingual glands (of von Ebner), the serous acinar cells showed a decrease in the number of secretory granules and an increase in lipofuscin accumulation. The ratios of cells containing lipofuscin granules were 11.39, 36.49 and 50.46%, respectively, of the control, 3- and 7-day post-axotomy glands (P < 0.001). Intraepithelial phagocytotic activity was increased. The mucous acinar cells in the posterior superficial lingual glands (of Weber) also showed degenerative changes after hypoglossal denervation. One week after nerve transection, marked cytoplasmic vacuolation and fragmentation of organelles were frequently observed. Degenerative changes were also found in unmyelinated axons associated with the glands. We provide the first evidence of the structural and functional connections between the sympathetic component of the hypoglossal nerve and posterior lingual glands.

Oral glands in dipsadine "goo-eater" snakes: morphology and histochemistry of the infralabial glands in Atractus reticulatus, Dipsas indica, and Sibynomorphus mikanii.

Although snake infralabial glands are generally constituted of mucous cells, among dipsadines, they are much more developed and predominantly serous in nature, possibly due to the peculiar feeding habits of some species of this group, the "goo-eaters", which feed on soft and viscous invertebrates. We compared the morphology and histochemistry of the infralabial glands of three goo-eater species of Southeast Brazil, Atractus reticulatus, Dipsas indica and Sibynomorphus mikanii. In A. reticulatus the glands are formed by mixed acini composed of mucous and seromucous cells and in D. indica, they are composed of mucous tubules and seromucous acini. In S. mikanii the glands are organized in seromucous acini; mucous cells are restricted to the gland anterior region and to the duct lining epithelium. Ultrastructurally, secretory granule electron density varies from low to moderate, depending on their mucous or seromucous nature. The results indicate a large morphological and histochemical variation in the infralabial glands, probably reflecting differences in the secretion chemical composition and in feeding specialization among the three species. The protein content in the secretory cells can be related with the presence of toxins that can be used in chemical prey immobilization or detaching of snails from their shells.

Glándulas linguales de Blandin y Nuhn; estudio histoquímico de los glicoconjugados de las células serosas y mucosas / Blandin and Nuhn lingual glands; an histochemical study of serous and mucous sugars

Se emplearon las técnicas histoquímicas convencionales para mucinas (PAS, Alcian blue y Azul de toluidina) y la técnica de avidina-biotina para estudiar la unión de las lectinas PNA, UEA-1, RCA-1, ConA, DBA, SBA y WGA a los azúcares específicos en cortes histológicos de glándulas inguales anteriores de Blandin y Nuhn. Las células secretoras mucosas y serosas exhibieron diferentes grados de coloración dependiendo de la lectina y el tipo celular. Estos resultados proveen las bases para la comparación de posibles cambios en las enfermedades de las glándulas salivales menores

Localisation of epidermal growth factor receptor in mucous cells of human salivary glands.

EGFR activation has been related to an increase in synthesis and secretion of mucins in epithelial cells, so that the use of EGFR tyrosine kinase inhibitors has been proposed in the therapy of mucin hypersecretory diseases. In this paper, we describe the ultrastructural localisation of EGFR in the mucous elements of human major and minor salivary glands and relate it to mucin distribution. A post-embedding immunogold staining method has been applied to normal surgical samples of human submandibular, sublingual, and labial glands, using a mouse monoclonal antibody specific for the intracellular domain of human EGFR. In mucous cells of all the glands examined, specific reactivity was detected in the cytoplasmic basolateral portions and near the mucous droplets, but not on cell surfaces. Since this pattern of labelling must be related to the internalisation process of the ligand-GFR complex, our results support the hypothesis that EGFR activation takes place in mucous cells and affects mucin production in human salivary glands.

[The glands of the dorso-distal mucosa of the toad Bufo marinus (Amphibia: Anura) tongue: histology and ultrastructure ]. / Las glandulas de la mucosa dorso-distal de la lengua del sapo Bufo marinus L. (Amphibia: Anura): histologia y ultraestructura.

Frequently, the studies on the lingual epithelium ultrastructure in anurans do not show differences between filiform papilae and glandular epithelia in the non-sensory dorsal epithelium. To accomplish the study of glandular epithelium, samples of dorso-distalis mucosae of Bufo marinus tongue were processed for transmission electron microscopy and also semithin sections of the same material were used for light microscopy study. The results showed that the glandular epithelium is constituted by three different types of cells: (1) serous granular secretory cells; (2) mitochondria rich cells (CRM); and (3) ciliated cells. Detailed structures of each type of cell under light and electron microscopy were given. Notably, in the lingual portion studied, secretory cells showed no signs of exocytosis of their granules, thus suggesting that they do not have a basal or continuous rate of secretory activity. Additionally, the distribution, localization and structure of CRM in the gland epithelium suggest their participation in secretory cell maturation and/or function.

A high resolution sem study of human minor salivary glands.

By SEM we have investigated the human minor salivary glands using the NaOH method for the visualization of endpieces and myoepithelial cells, and the osmium maceration technique that reveals membranous intracellular structures. With the former method all minor glands, including the posterior deep (Ebner's) lingual glands, consist of tubules sometimes dilated into alveoli, while true acini of the kind observed in human major salivary glands, are absent. Tubules of the posterior deep lingual gland exhibit stellate myoepitelial cells that leave a substantial part of the secretory cells uncovered. The latter cells, at variance with serous cells of major glands, do not show basal folds. In contrast, tubules of the other minor glands, like the mucous ones of major glands, are covered almost completely by band-like myoepithelial cells. The osmium maceration method clearly demonstrates that posterior deep lingual glands are serous in character and that all the other minor glands, together with the predominant mucous cells, possess a variable number of seromucous cells that, despite variations among individuals, increase in order from palatine and posterior superficial lingual (Weber's), to minor sublingual, labial, anterior lingual (Blandin and Nuhn's), and buccal glands.

Three-dimensional structure of oncocyte mitochondria in human salivary glands: a scanning electron microscope study.

Oncocytes occurring in otherwise normal human salivary glands were examined by scanning electron microscopy after being subjected to a maceration technique that removes all soluble cytoplasmic components and leaves only membranes in place. The three-dimensional images resulting from this procedure confirm that the majority of oncocyte mitochondria have shelf-like cristae that are attached to the inner boundary membrane, often by means of tubular structures. In some mitochondria, the cristae are digitiform and, when transected, give rise to putative vesicles. The oncocytic mitochondria in human salivary glands, by and large, lack the structural irregularity that has been reported for these organelles occurring in oncocytes in other organs.

Ultrastructural localization of E-cadherin and alpha-/beta-catenin in adenoid cystic carcinoma.

AIMS: To investigate the disturbance of intercellular adhesion in adenoid cystic carcinoma (ACC), we examined the ultrastructural localization of E-cadherin (E-cad), alpha-catenin (alpha-cat) and beta-catenin (beta-cat) in ACC, and compared it with that in the normal labial gland. METHODS AND RESULTS: Using immuno-electron microscopy, in the normal labial gland, E-cad was found to be uniformly distributed along the plasmalemma, where cells were in close contact with each other, with junctional complexes, desmosomes and interdigitations; expression of alpha-cat and beta-cat was also detected. In ACC, which was classified into tubular, cribriform and trabecular types, E-cad expression seemed not to be uniform, but was observed to be along the plasmalemma where cell-to-cell contact was made. On the other hand, expression of alpha-cat or beta-cat was uneven in the trabecular-type cells which were very slender and grew in an infiltrative scattered pattern into the extracellular matrix; that was absent in the cribriform-type cells which made contact with each other mostly at the tip of the cytoplasmic processes. CONCLUSION: These findings suggest that the neoplastic cells of ACC express E-cad for use in intercellular adhesion, but the cadherin-catenin complex might not operate properly, which is the cause of neoplastic cell dissociation, followed by invasion and metastasis.

Biosynthesis of glycosaminoglycans and aggrecan by tumor cells in salivary pleomorphic adenoma: ultrastructural evidence.

The present study attempted to discover the sites of synthesis of various glycosaminoglycans (GAGs) and aggrecan in salivary pleomorphic adenoma (PA) with the use of a highly sensitive and specific post-embedding immunogold-silver staining technique at the ultrastructural level. Silver particles representing various GAGs and aggrecan were found to accumulate frequently in the intercellular spaces of non-luminal cells in the epithelial clusters and were dispersed in the myxoid matrix of the mesenchyme-like areas. Furthermore, the non-luminal epithelial cells were demonstrated to contain immunopositive intracytoplasmic vesicles and vacuoles, some of which were of Golgi complex origin. In contrast, intracellular silver particles for hyaluronic acid were mostly attached to the inner surface of the cell membrane. These observations agree well with the current theories of the biosynthesis of GAGs and proteoglycans and provide direct evidence for the production of various GAGs and aggrecan by tumor epithelial cells of PA. Such findings support the ideas that in PA a loss of epithelium occurs by stromalization following epithelial secretion of extracellular matrix substances and transformation of epithelium to mesenchyme represents the basic principle of the tissue heterogeneity in this tumor.

Crystalloid architecture of a sialolith in a minor salivary gland.

A sialolith from a minor salivary gland of the mucosa of the upper lip was studied morphologically and analytically. Under stereoscopic microscopic visualisation, no core or any concentric laminar structure was found in the sialolith and it had a transparent glassy appearance. Scanning electron microscopy revealed differences between the internal structure of the sialolith and its external structure. No microbes were observed but some mineralized inclusion bodies were seen. X-ray diffraction indicated the absence of inorganic crystals in the sialolith, while energy dispersive x-ray microanalysis revealed a high content of S followed by Ca, Si and Na and little and scarce P on the fracture surface, with S, Na, Ca and P being distributed throughout the external coating of the sialolith. The results suggest that the sialolith was young and consisted of a crystalloid body with an incipient coating undergoing calcification.