Primary intraosseous odontogenic carcinoma (PIOC) is a carcinoma arising within the jaws, putatively developing from remnants of odontogenic epithelium. We describe a case of PIOC arising from odontogenic cyst affecting the left posterior mandible of 72-year-old Korean man. Clinical examination showed a symptom-free hard mass. There was no evidence of ulceration, and there was no pain or bleeding. The overlying mucosa was intact and no regional lymph nodes were palpable. Clinical and radiological studies for other distant primary sites were negative. Radiographically, the tumor showed multilocular radiolucency with a noncorticated, ill defined border surrounding an impacted third molar tooth. Histology exhibited sheets or islands of nonkeratinizing malignant epithelial cells with minimal clear cell component in continuity with begin or dysplastic cyst lining epithelium. Immunostaining for PCNA and p53 protein showed a higher percentage of positive cells and more intense staining in the carcinomatous tissues than in the benign and dysplastic lesions.

The ossifying fibroma (OF), with the microscopic features of trabuclae or spherules of bone or cementum-like material in a cellular fibrous connective tissue stroma, is one of the most common benign fibro-osseous lesions in the jaw bones. The OF often occurs in patients from 20 to 40 years of age, which is a definite female predilection. The mandibles are involved far more often than the maxillas, especially the pre-molar and molar regions. It is slow-growing, bone producing, asymptomatic and well-demarcated. The OF is a disorder of odontogenesis or osteogenesis ascribed to bone marrow stroma cells (BMSCs) abnormality. However, the detailed mechanisms of OF’s oncogenesis, cytodifferentiation, and tumor progression remain unknown. In this article, we reported a huge central OF on the anterior mandible. The lesion was enucleated and peripheral ostectomy was done via intraoral approach and reconstructed with vascularized iliac block bone graft. After 25 months of follow up, the tumor had not recurred. This case shows that OF may be successfully treated by conservative surgical enucleation and peripheral ostectomy.

Combined epithelial odontogenic tumors are very rare and represent hybrid lesion comprising adenomatoid odontogenic tumor intermixed with calcifying epithelial odontogenic tumor. The authors present 3 cases of combined epithelial odontogenic tumor which contained diagnostic areas for both adenomatoid odontogenic tumor and calcifying epithelial odontogenic tumor. Their behaviour and histogenesis were discussed.

System L amino acid transporter is a major route for providing living cells with neutral amino acids including several essential amino acids. To elucidate the expression pattern of L-type amino acid transporter 1 (LAT1) in the bone formation process, the expressions of LAT1 and its subunit 4F2 heavy chain (4F2hc) were investigated in the healing process after the implantation of bone graft materials in the calvarial osseous defected rats. Circular calvarial defects (1 cm in diameter) were made midparietally. The rats were divided into 4 groups of 1 control group and 3 experimental groups. In the control group, the defect was only covered with soft tissue flap. In the experimental groups, they were filled with human particulate dentin (particulate dentin group), with plaster of Paris (plaster of Paris group) and with the mixture of human particulate dentin and plaster of Paris with ratio of 2 : 1 by weight (mixture group). The rats were sacrificed at the 1, 2, 4 and 8 weeks after operation and the RT-PCR analysis and immunohistochemical analysis were performed. In the RT-PCR analysis, the mRNAs of LAT1 and 4F2hc were strongly detected in all 4 groups. In the immunohistochemical analysis, at 1 week after operation, the LAT1 protein and its subunit 4F2hc protein were mainly expressed in the osteoblasts, osteocytes and interstitial tissues of the around the defect and inner part of newly forming bone in all 4 groups. The expressions of LAT1 and 4F2hc proteins were decreased at 2 and 4 weeks after operation. The LAT1 and 4F2hc proteins were scarcely expressed at 8 weeks after operation in all 4 groups. These results suggest that the LAT1 and its subunit 4F2hc highly expressed at the early stage of new bone formation and may have an important role in providing cells with neutral amino acids including several essential amino acids at that stage.

The relationship between the distribution of sea surface temperature(SST) and dinoflagellate(Cochlodinium polykrikoides) bloom areas were studied. The SST data were derived from the infrared channels of AVHRR(Advanced Very High Resolution Radiometer) sensor on NOAA(National Oceanic and Atmospheric Administration) 12 and 14 satellites during 1995-1998. The initial water temperature at C. polykrikoides bloom was about 21℃ at the coastal areas of the South Sea and along the shore of the East Sea of Korea during the summer season of 1995. The northern limit of red tides was coincident with that of 21℃ isothermal line in the East Sea. The red tides that initially bloomed at the coast of Pohang on September 21, 1995 moved to the coast of Uljin on September 26, 1995. The skipped appearance of the red tides in the areas between Pohang and Uljin was due to the East Korean Warm Current, which was moving offshore from Pohang to approach to Uljin. The cold water which was formed by tidal front in the western coast of the South Sea and by upwelling water from deep layer in the southeastern coast of the Korean peninsula played a role in blocking the spreading of red tides during summer season in 1997 and 1998. In conclusion, the distribution of red tides appeared to be dependent on the initial water temperature at red tides bloom. The SST at the red tides varied from 21℃ to 25℃ ; 21℃, 23℃, 24℃ and 24-25℃ in 1995, 1996, 1997 and 1998, respectively.