The Bulletin of Tokyo Medical and Dental University最新文献

The effects of cancer sera on the in vitro induction of lymphokine activated killer (LAK) cells and the killer activity of the LAK cells were determined. When the peripheral blood lymphocytes (PBLs) were incubated with recombinant interleukin-2 in a medium (RPMI 1640 + 10% normal human AB serum) for 96 hours, 53-55% of the LAK activity were induced. LAK induction was inhibited when cancer sera were added to the medium. The inhibition rates varied from slight to high (a mean LAK activity; 37.1%). The cancer sera also inhibited the killer activity of the LAK cells which were already induced in the PBLs. These results suggested the presence of an inhibiting factor against the LAK cells in the cancer serum.

P. micros is thought to be an important pathogen in the etiology of certain inflammatory lesions, however, the role of this microorganism is uncertain due to the lack of rapid and reliable method to identify this species. The purpose of this study was to develop a DNA probe specific for the detection of P. micros in order to evaluate its prevalence in oral infectious lesions. The whole genomic DNA from P. micros was partially digested and inserted into the vector pUC 13. Four recombinant clones were selected, purified and screened against reference strains of Peptostreptococcus species to check the species specificity and then applied to clinical isolates. The sensitivity and specificity of the DNA probe for P. micros was 99.2% and 100%, respectively. P. micros could be detected in 7.2% of subgingival dental plaques from the patients with adult periodontitis and in 16.1% of the endodontic lesions with periapical pathosis. In the endodontic lesions, there was a good correlation between the clinical symptoms and the presence of P. micros. These data strongly suggested that the DNA probe can be useful in the detection of P. micros and that this microorganism is important in certain periodontal and endodontic lesions.

A rare case of papillary adenocarcinoma located in the sublingual region is presented. This case was initially considered to be a hemangioma and then the tentative clinical diagnosis was thyroglossal duct cyst at the time of the operation under general anesthesia. However, the final histopathologic diagnosis was papillary adenocarcinoma. We investigated its origin by histological, ultrastructural and histochemical techniques and it was suggested that this tumor arose from the minor salivary gland.

Forty-four patients with oral cancer were examined by ultrasonography to detect cervical lymph nodal metastases. The lymph nodes, which were histopathologically or clinically confirmed to have cancer metastases, showed the following characteristic echogram findings: distinctive nodal boundary, posterior echo enhancement and an increased ratio of the shortest and the longest diameters of the node. It is suggested that these three peculiar ultrasonographic findings are considered to be important items for the differential diagnosis of benign nodes from the cervical metastasis of oral cancer.

Serum IgG level against Streptococcus mutans serotype c was studied in 33 subjects, in relation to dental caries, oral hygiene and age. The activity of the serum IgG against the sonicated antigens of the bacterium was evaluated by micro-ELISA. The serum IgG titer to S. mutans was significantly higher in the subjects with no detectable carious lesions than in the subjects with active caries (p less than 0.05). However, there was no clear difference between the serum IgG antibody to S. mutans and the DMF index. The serum IgG antibodies to S. mutans were associated with the level of oral hygiene but not with age.