• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.81-93
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• 2006

Obstructive sialadenitis is one of common disease in salivary gland, and most common histologic features are loss of acinar cell and ductal dilatation associated with fibrosis, and infiltration of inflammatory cells. Although many experimental studies has been accomplished for the salivary acinar cell change in obstructive salivary gland disease, studies for myoepithelial cell were deficient. This study is designed for salivary gland tissue change, especially myoepithelial cell when nonspecific chronic sialadenitis or salivary duct injury by duct obstruction or cut can be occurred that is common encounted clinically. After ligation and cutting of submandibular gland of rabbit, groups of aminmal were sacrificed at 1, 2, 4 weeks postoperatively, submandibular gland were removed. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining with ${\alpha}$-smooth muscle actin, characteristics of myoepithelial cell were examined. With transmission electron microscopy, ultrastructure of myoepithelial cell were examined for distribution and ultrastructure of myoepithelial cell. The results were obtained as follows: 1. In the histopathologic evaluation, ligation and cutting group of 1 week, linkage of myoepithelial cell associated with acinar atrophy and degeneration were disappeared in both group. 2. More prominent squamous metaplasia was seen in acinar cells of ligation group of 2 weeks experimental rabbit than cutting group. 3. Acinar cells are nearly disappeared in both ligation and cutting group of 4 weeks, and myoepithelial cell also disappeared associated with acinar cell atrophy, and duct-like structure composed by squamous cells by squamous metaplasia in acinar cells were distributed. 4. In immunohistochemical study, both ligation and cutting group ${\alpha}$-SMA distribution were diminished at 1 week experimental rabbits, but myoepithelial cell was more diminished in ligation group than cutting group, which were distributed around cells of squamous metaplasia. 5. Nuclear condensation, chromosome margination, and cytoplasmic vaculoation were appeared in myoepithelial cell of both cutting and ligation group after 1 week with transmission electron microscopy. But degenerative substance were seen in cytoplasm of myoepithelial cell of ligation group of 4 weeks. From the results obtained in this study, atrophy and degeneration of myoepithelial cell was more prominent in duct ligation group than duct cutting group, and myoepithelial cells were seen around cells squamous metaplasia of acinar cell.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.479-484
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• 2007

A case of epithelial-myoepithelial carcinoma transformed in pleomorphic adenoma occurring in palate of a 61 years old woman is reported. The tum or was composed of 2 different components, pleomorphic adenoma and epithelial myoepithelial carcinoma, accounting for approximately 40% and 60% of whole tumor, respectively. As the results of the immunohistopathologic study, epithelial-myoepithelial carcinoma showed multiple tubular or solid nest, which were separated by a basement membrane and considered of variable proportion of 2 cell types, cuboidal epithelial cells positive for cytokeratin and clear myoepithelial cells positive for glial fibrillary acid protein, wheres the myoepithelial nest of pleomorphic adenoma intermingled with hyaline and myxoid stroma. The malignancy was demonstrated by convincing evidence of invasion into the submucosa, although the epithelial-myoepithelial carcinoma component was mostly surrounded by the pleomorphic adenoma componemts. An increased immunoreactivity of proliferating cell nuclear antign in the epithelial myoepithelial carcinoma area in comparison to the pleomorphic adenoma also suggested epithelial-myoepithelial carcinoma arising in a pleomorphic adenoma.

• Korean Journal of Bronchoesophagology
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• v.6 no.1
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• pp.108-112
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• 2000

Epithelial-myoepithelial carcinoma(EMC) is a rare low grade malignant salivary gland neoplasm that most commonly occurs in the parotid gland but can also arise in minor salivary glands. It is a distinct neoplasm characterized by tubular and solid growth patterns and a dual cell population including an inner larger of cuboidal to columnar epithelial cells which are peripherally bounded by a layer of myoepithelial cells with distinctly clear cytoplasm. The clinical course is characterized by a high incidence of local recurrence and not infrequent distant metastasis. The differential diagnosis included acinic cell tumor, adenoid cystic carcinoma, mucoepidermoid carcinoma, sebaceous carcinoma and pleomorphic adenoma. We report a case of EMC of left parotid gland in a 55-year-old woman.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.649-656
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• 2003

We have a cultured method to grow rat mammary epithelial cells (RMEC) for 1 to 14 days in 1:1 mixture of Dulbecco's Modified Eagle Medium: Nutrient and F-12 (DMEM/F-12) containing 10% fetal bovine serum (FBS), human EGF, insulin, hydrocortisone, human transferrin and $17{\beta}$-estradiol in vitro. We were able to isolate and distinguish two cell types, luminal epithelial cells and myoepithelial cells, from primary clutures of RMEC. Immunocytochemical stains were used to distingusih luminal epithelial cells and myoepithelial cells. Peanut lectin (PNA) was stained in most alveolar epithelail cells and luminal epithelial cells of rats, while Thy-1.1, a maker of potential rat mammary myoepithelial cells, was expressed in myoepithelial cells in the rat. Also, we examined the expression patterns of three types of gap junction proteins, connexin 26 ($C{\times}26$), connexins 32 ($C{\times}32$) and connexin 43 ($C{\times}43$) by immunocytochemistry and western blot analysis. In the cell types, the results show that at the early stage of culture, luminal epithelial cells were increased and these cells were surrounded by myoepithelial cells. At the late stage of culture, luminal epithelial cells were decreased, in contrast myoepithelial cells were increased. In the expression pattern of gap junction, $C{\times}26$ maintained it's expression until day 3, but afterwards gradually decreased in intensity. Expression of $C{\times}32$ remained until day 5, then decreased slightly. $C{\times}43$ gradually increased untill the middle time of culture then decreased in intensity. These results suggest that connexins may be important for the control of growth in rat mammary epithelial cell types.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.131-134
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• 2003

Epithelial-myoepithelial carcinoma(EMC) of the salivary glands is a rare tumor first discribed in 1972. The EMC comprises approximately 1% of all salivary gland tumors. It is characterized by tubular and solid growth pattern with a dual cell population including an inner layer of epithelial cells, which is peripherally bounded by a layer of clear myoepithelial cells. It is demonstrated that tumor with solid slowly growing pattern, generally have a higher frequency of local recurrence. We report a case of parotidic EMC in a 30 years old woman with literature review

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.6
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• pp.533-537
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• 2010

Sialadenoma papilliferum (SP) is a rare benign neoplasm that normally arises from the minor salivary glands, particularly in the palate. SP is normally encountered in older men with an exophytic papillary surface growth. In the present study, an SP of the hard palate of a 69-year-old woman was examined immunohistochemically. Myoepithelial cell markers, such as S-100, smooth muscle actin and vimentin, were observed in the basal or luminal layer of tumor cells, indicating that myoepithelial cells participate in the pathogenesis of SP. In addition, cytokeratin 7 was also strongly detected in the tumor cells, suggesting that excretory ductal epithelial cells have a role in its histogenesis. A review of the literature of immunohistochemical studies on SP showed that the expression and co-expression of cytokeratins and myoepithelial cell markers have been reported in tumor cells. These results suggested that excretory duct cells and myoepithelial cells participate in the pathogenesis of SP.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.238-241
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• 2001

Epithelial-myoepithelial carcinoma is a rare neoplasm comprising approximately 1% of all salivary gland neoplasms. Histopathologically, the carcinomas are characterized by a dual cell population of an inner duct-forming epithelium and an outer myoepithelial cell. They are characterized by their variable clinical course and a lack of features that predict clinical outcome. The following report describes our experience with this type of tumor. We suggest that radiation therapy and long term follow-up will be necessary because this tumor have a high risk of locoregional aggressiveness.

• Journal of Oral Medicine and Pain
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• v.39 no.3
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• pp.83-89
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• 2014

Purpose: Chronic nicotine administration induce various effects in whole organs of the body; however, little is known about salivary gland. In the present study, we pursued the links between systemic nicotine and the histomorphological changes of the salivary gland in mice. Methods: Twenty-five C57BL6 mice were allocated into two groups. The control group (n=9) received distilled water only for 8 weeks by gavage. The experimental nicotine group (n=16) was administered nicotine $5{\mu}g/g$ with distilled water. Animals were sacrificed at 8 weeks; then, submandibular glands were excised and processed for histologic evaluation. Volumetric changes in acinar cells were evaluated by H&E staining. The expression of calponin-positive myoepithelial cells and Ki-67-positive proliferating acinar cells were evaluated by immunohistochemistry. Results: The nicotine group showed significantly decreased number of calponin-positive myoepithelial cell process compared with the control group. There were no significant differences in average volume of acinar cell and the number of Ki-67-positive acinar cells between both groups. Conclusions: These findings suggested that chronic nicotine administration may cause decreased function of myoepithelial cells in submandibular glands of mice, and these can partly explain xerostomic conditions in chronic smokers.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.428-431
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• 2015

Epithelial-myoepithelial carcinoma (EMC) of lung is a minor subset of salivary type carcinoma of lung of known low grade malignancy. Histologically, two-cell components forming duct-like structure with inner epithelial cell layer and outer myoepithelial cell layer are characteristics of EMC. In salivary gland, dedifferentiation of conventional low grade malignancy has been reported and is thought to be related with poor prognosis. However, precise histomorphology and prognostic factors of pulmonary EMC have not been clarified due to its rarity. Herein, we reported a rare case of EMC presented as endobronchial mass in a 53-year old woman, which showed predominant solid lobular growth pattern and lymph node metastases.

• Applied Microscopy
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• v.25 no.1
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• pp.86-95
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• 1995

This study was accomplished to investigate the ultrastructure of mucous glands in dorsal skin of frog (Rana catesbeiana) by means of scanning and transmission electron microscopes. The dorsal skin of Rana catesbeiana is composed of epidermis and dermis. The cutaneous mucous glands consist of inner glandular epithelial cells and outer myoepithelial cells. Glandular epithelial cells are divided into four types by the microscopic ultrastructure; ER-rich cell, round secretory granule-containing cell, foam-like granule mass-containing cell, mitochondria-rich cell. Myoepithelial cell has a long elliptical nucleus and filled with fibrous materials in the cytoplasm. As a result of scanning microscopic observation, the surface of dorsal skin is covered with cutaneous protrusions. The opening sites of the mucous glands are irregularly distributed in dorsal skin.