PubMed Health⌕ Search

Biomedical subjects

Masashi Shimahara

Publications and source records attributed to Masashi Shimahara.

6 recordsLinked to original sources

Closed treatment of condylar fractures by intermaxillary fixation with thermoforming plates.

We report a new intermaxillary fixation (IMF) method for condylar fractures using a thermoforming plate. Fifteen cases of condylar fracture were selected and thermoforming plates were applied. The patient's recover was uneventful in all 15 cases, and the period of IMF ranged from 7 to 17 days, (mean 12) for the following 7 days IMF was used only at night together with functional jaw training during the day. The outcome was good. IMF using a thermoforming plate may be a useful technique for selected condylar fractures.

Adolescent↗

Study on chemosensitivity of oral squamous cell carcinomas by histoculture drug response assay.

The aim of this study was to evaluate the reliability and utility of a histoculture drug response assay (HDRA) for treatment of squamous cell carcinoma in the oral cavity. Nineteen patients with squamous cell carcinoma of the oral cavity were assessed. Tumor tissue samples were histocultured on Gelfoam sponge gels in 24-well plates, followed by treatment with 5-fluorouracil (5-FU, 300 microg/ml), cisplatinum (CDDP, 20 microg/ml), 4-0-tetrahydropyranyl adriamycin (THP, 4.6 microg/ml), bleomycin (BLM, 20 microg/ml), adriamycin (ADM, 15 microg/ml) and docetaxel (TXT, 100 microg/ml). The controls were cultured without drug treatment. After completion of the culture, the relative cell survival in the tumors was determined using an MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide) assay. The inhibition rate was calculated, and sensitivity was defined as a tumor inhibition rate greater than 60% for 5-FU, 40% for TXT, and 50% for the other drugs. All cases were successfully evaluated by the HDRA, and no apparent relationships between the chemosensitivity test results and clinico-histopathological characteristics were seen. CDDP tended to be sensitive, whereas 5-FU, THP, and BLM tended to show resistance in many cases. A good correlation was obtained between the chemosensitivity test results and clinical response. In conclusion, HDRA is a useful method for selection of an anticancer agent for individual oral cancer patients, because of its ease of evaluation and high predictability.

Adult↗

Clear cell odontogenic carcinoma with ghost cells and inductive dentin formation - report of a case in the mandible.

An atypical case of clear cell odontogenic carcinoma occurred in the mandible of a 50-year-old Japanese man. Microscopically, the tumor mainly consisted of clear, glycogen-rich epithelial cell nests, aggressively proliferated in the mandible and invading into the surrounding soft tissues. Within the tumor cell nests, clusters of ghost cells were observed in addition to occasional foci of microcystic degeneration. Hyaline, osteoid or dentinoid-like deposits were also demonstrated adjacent to the tumor cell nests. Dentinal tubules were clearly revealed in some of these structures. Hence, this tumor was regarded as an epithelial neoplasm with odontogenic ectomesenchyme induction.

Dentin, Secondary↗