In vitro characterization of human dental pulp stem cells isolated by three different methods

OBJECTIVES: In this study, we characterized human dental pulp cells (HDPCs) obtained by different culture methods to establish the most suitable methodology for dental tissue engineering and regenerative endodontic applications. MATERIALS AND METHODS: HDPCs were isolated by the outgrowth method (HDPCs-OG), the enzymatic digestion method (collagenase/dispase/trypsin, HDPCs-ED), or the combination of both methods (HDPCs-Combined). The expression of mesenchymal stem cell markers (CD105, CD90, and CD73) was investigated. In vitro differentiation capacities of HDPCs into adipogenic, osteogenic, and chondrogenic lineages were compared. Differentiation markers were analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and western blotting. RESULTS: Our data indicated that whole HDPCs-ED, HPDCs-OG, and HDPCs-Combined could be differentiated into adipogenic, chrondrogenic, and osteogenic cell types. However, we found that the methods for isolating and culturing HDPCs influence the differentiation capacities of cells. HDPCs-OG and HDPCs-ED were preferably differentiated into adipogenic and osteogenic cells, respectively. Differentiation markers shown by RT-PCR and western blotting analysis were mostly upregulated in the treated groups compared with the control groups. CONCLUSIONS: Our findings confirmed that cell populations formed by two different culture methods and the combined culture method exhibited different properties. The results of this study could provide an insight into regenerative endodontic treatment using HDPCs.

Clinical management of a fused upper premolar with supernumerary tooth: a case report

In dentistry, the term 'fusion' is used to describe a developmental disorder of dental hard tissues. In the permanent dentition, fusion of a normal tooth and a supernumerary tooth usually involves the incisors or canines. However, a few cases of fusion involving premolars have also been reported to date. We present a rare case in which fusion of the maxillary left second premolar and a supernumerary tooth in a 13-year-old girl was diagnosed using cone beam computed tomography (CBCT, Alphard-3030, Asahi Roentgen Ind. Co., Ltd.). The tooth was bicuspidized after routine nonsurgical root canal treatment, and the separated teeth underwent appropriate restoration procedures. The second premolar and supernumerary tooth remained asymptomatic without any signs of inflammation after a follow-up period of 9 years. Identification of anatomical anomalies is important for treatment in cases involving fusion with supernumerary tooth, and therefore the microscopic examinations and CBCT are essential for the diagnosis. Fused teeth can be effectively managed by the comprehensive treatment which includes both endodontic and periodontal procedures.

Immunohistochemical Study on MAPK Expression in Seborrheic Keratosis and Squamous Cell Carcinoma by Sun Exposure / 대한피부과학회지

BACKGROUND: Mitogen-activated protein kinase (MAPK) is a key molecule in intracellular signal transducing pathways that transport extracellular stimuli from cell surface to nuclei. The MAPK family, comprised of extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinases, could be activated by a number of growth factors, cytokines, and other stimuli such as UV light, and has been implicated in the regulation of cell proliferation, tumorigenesis, differentiation, and apoptosis. OBJECTIVE: The purpose of this study was to immunohistochemically analyze the expression of ERK and JNK in epidermal tumors, including seborrheic keratosis (SK) and squamous cell carcinoma (SCC) on sun-exposed skin and unexposed skin. METHOD: SK on sun-exposed skin (5 cases) and unexposed skin (5 cases), and SCC on sun- exposed skin (5 cases) and unexposed skin (5 cases) were immunohistochemically stained with ERK and JNK monoclonal antibodies. RESULTS: ERK was more strongly expressed than JNK in all the cases. In the sun-exposed skin of SK and SCC, ERK was more definitely expressed than in the unexposed area. JNK was not expressed in all tumor cells of SK and SCC. CONCLUSION: This study strongly indicates that ERK expression may be related to sun exposure and responsible for proliferation of tumors. On the other hand, JNK may not be associated with tumor progression, caused by sun exposure.

A Case of Cylindroma on the Upper Left Extremity / 대한피부과학회지

Cylindromas are rare benign adnexal tumors that arise primarily on the scalp. There are 2 distinct clinical forms: a solitary form, which is sporadic, and a multiple form, which is dominantly inherited. The lesions are pink-red, nodular, firm, and usually painless, and vary in size. On light microscopic examination, the tumors are nonencapsulated and are located in the upper dermis. They are composed characteristically of aggregations of islands of basaloid cells arranged in a jigsaw pattern and surrounded by hyaline sheaths. Malignant transformation occurs rarely, although some have argued that cylindromas are always benign. We report a man who developed a cylindroma on the upper left extremity, which is an unusual site.

Changes in Expressions of Endothelin-1, Microphthalmia Associated Transcription Factor, and Protease-activated Receptor-2 after Ultraviolet Irradiation / 대한피부과학회지

BACKGROUND: A number of cytokines, growth factors and inflammatory mediators made by keratinocytes, fibroblasts and potentially other cells in the skin were shown to augment melanin production and/or melanin transfer to keratinocytes. A lot of studies were done to investigate the mechanisms. But there was no studies about sequential relationship between the suggestive factors. OBJECT: To measure the changes in expressions of ET-1, MITF, and PAR-2 after UV exposure on skin in Korean. MATERIAL AND METHOD: We established an immunohistochemical staining protocol for specimens which were obtained from UV-irradiated skin in four healthy Korean males on the 2nd, 4th, 7th days after UV irradiation. RESULT: This study reveals the sequential relationship between ET-1, MITF, and PAR-2. ET-1 was increased at day 2 and decreased at day 4 and 7. MITF increased gradually day 2, day 4, and day 7. PAR-2 increased at day 4 and increased once more at day 7.

A Case of Hobnail Hemangioma / 대한피부과학회지

Hobnail hemangioma is a benign vascular tumor characterized by a violaceous or brown papule that is surrounded by a thin pale area and a peripheral ecchymotic ring. Histologically the lesion consists of a superficial dermal vascular proliferation. In the upper dermis, dilated vascular spaces often lined by endothelial cells that protrude in to the lumina and closely resemble hobnail. In the deeper dermis, slit-like vascular structures appeared to dissect between collagen bundles. It is important to distinguish these tumors from patch stage of Kaposi's sarcoma, solitary angiokeratomas, retiform hemangioma and progressive lymphangioma. We report a 29-year-old woman showing typical clinical and histological features of hobnail hemangioma.

A Case of Granulomatous Perioral Dermatitis / 대한피부과학회지

A 54-year-old female developed symmetrical, grouped, perioral papules affecting the perioral area for four years. Histologic examination revealed spongiosis and edema in the follicular infundibulum. Mild mononuclear cell exocytosis and perivascular lymphohistiocytic infiltration were seen. In addition, granulomatous areas were present. She had used topical corticosteroid intermittently and no associated systemic abnormalities. We made diagnosis that this condition was granulomatous perioral dermatitis, which began to resolve in about three weeks after oral doxycycline and topical metronidazole treatment.