Search PubMed⌕ Search

Biomedical subjects

Masashi Shimahara

Publications and source records attributed to Masashi Shimahara.

9 recordsLinked to original sources
PubMed2006

Relationships between dynamic contrast-enhanced MRI findings and pattern of invasion for tongue carcinoma.

The purpose of this study was to evaluate the effectiveness of dynamic contrast-enhanced MRI (DC-MRI) for assessing the pattern of invasion of tongue carcinomas. We studied 20 cases of squamous cell carcinoma of the tongue that showed peripheral enhancement patterns on DC-MRI. The diameter of each tumor was >2.0 cm and no apparent artifacts were seen. The signal enhancement to noise ratio (SE/N) of the regions of interest, which were located in the central and peripheral regions of the tumor, were measured using DC-MRI, while maximum SE/N, %-wash out, and the ascending rate of SE/N were also calculated. The histopathological pattern of invasion was assessed in each case and used to classify them into clear (13 cases) and diffuse (7 cases) groups, after which the 4 parameters were compared between the 2 groups. The ascending rate of SE/N in the peripheral region was significantly lower in the diffuse group (p=0.047). There were no other significant differences between the 2 groups for any parameter in either tumor region. These results suggest that DC-MRI is able to show the histopathological pattern of invasion into surrounding structures.

Adult↗
PubMed2005

Atrophic tongue associated with Candida.

BACKGROUND: Traditionally, total atrophic tongue has been due to nutritional deficiencies, such as vitamin B12, folic acid, or iron deficiencies, and partial atrophic tongue has been well known as median rhomboid glossitis or geographic tongue. The other cause of atrophic tongue is oral candidiasis. METHODS: Forty patients with atrophic change of the tongue were examined on a relation to candidiasis. All of them complained of tongue pain on spicy or hot diet. Laboratory examinations included blood examination for diabetes and anemia, culture test and direct cytologic examination. The intensity of tongue pain was evaluated pre- and post-treatment using visual analogue scale (VAS). RESULTS: Twenty-four of 40 (60%) had pre-disposing factors of candidiasis including diabetes mellitus, malignancy, systemic steroid therapy, long-term antibiotic therapy and others in their medical history. Blood examinations revealed mild anemia and/or Fe deficiency in 5 (12.5%), mild diabetes in 4 (10.0%), both in two, while residual 29 patients (72.5%) were within reference levels. In the culture examination, candidal species were isolated in 72.5%, and almost all of them were candida albicans. The direct cytologic examination performed in 17 of 40 patients, witch revealed pseudohyphae of fungi in 14 patients (82.4%). After the antifungal treatment, the tongue pain disappeared or improved markedly in 80%. Simultaneously, the regenerative tendency of filifolm papilla of the tongue dorsum was observed in these patients. CONCLUSION: Atrophic tongue associated with pain at eating, even though it is mild atrophic change, has a high probability of being a candida-induced lesion. Long disease duration and no benefit by topical steroids are suggestive and diagnostic factors of this disease.

Adult↗
PubMed2004

Evaluation of speech intelligibility after a secondary dehiscence operation using an artificial graft in patients with speech disorders after partial glossectomy.

The purpose of this study was to evaluate speech intelligibility after a dehiscence operation using artificial grafts for patients with speech disorders after partial glossectomy that were caused by scars resulting from the primary operation. The subjects were six men and three women, who had had a partial glossectomy for tongue cancer followed by direct closure without reconstruction. They were operated on a second time operation to mobilise the residual tongue by dividing the cicatrix. An artificial graft was applied to the wound to maintain the dehiscence. Speech intelligibility was evaluated by a standardised Japanese speech intelligibility test before, and 6 and 12 months after the second operation. The intelligibility scores significantly improved during the first 6 months after the second operation, and continued to improve slightly during the following 6 months. This study suggests that the dehiscence operation using an artificial graft could improve speech in patients after partial glossectomy.

Adult↗
PubMed2004

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↗
PubMed2003

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↗
PubMed2002

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↗