We investigated immunohistochemical expression of pRb, cyclin D 1, and cdk 4 in rat tongue carcinoma induced by 4-nitroquinoline 1-oxide. pRb expression in carcinoma decreased compared with that in dysplastic lesions, while expression of cyclin D 1 and cdk 4 increased gradually during the course of carcinogenesis. Phosphorylation of pRb was analyzed by immunoblotting using the G 3-245 antibody, which recognizes both phosphorylated (pp 110^<RB>) and unphosphorylated pRb (p 110^<RB>). Although expression of pp 110^<RB> notably increased in the dyspiastic membrane, it almost disappeared in carcinoma. p 110^<RB> was also expressed in control and dysplastic membranes, but not in carcinoma. We found there was a decrease of pRb and an increase of cdk 4 and cyclin D 1 in the premalignant stage. A decrease in the amount of pRb and an increase in its phosphorylation may prevent G 1 arrest and consequently accelerate proliferation of chemically injured cells.

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In order to clarify how cerebrospinal fluid (CSF) is excreted into the cervical lymphatic vessels, we infused 30μL of India ink into the lateral ventricle of rats, and evaluated the route of excretion of carbon particles outside the cranium using macroscopic and histological techniques. We also evaluated the relationship between the time required for delivery of the ink into the deep cervical lymph nodes (t) and intracranial compliance (Co). In this study, the carbon particles reached the deep cervical lymph nodes within 30 minutes after administration, and a positive correlation was observed between t and Co. Histological evaluation revealed that carbon particles moved to the perineurium of the olfactory nerve, penetrated the cribriform plate, leaked into the nasal mucosa, were taken up by the lymphatic system, and were then delivered to the cranial deep cervical lymph nodes. Although carbon particles were observed around the optic nerve, and some particles were delivered into subcutaneous lymphatics, they were small in number. The results of this study indicated that the route to the nasal mucosa via the cribriform plate is most important as a route of excretion of CSF from the brain to the cervical lymphatics, and that this route also plays an important role in buffering increases in intracranial pressure.

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I investigated changes in the activity of the masseter and temporal muscles, and changes in the position of the incisal point when intermaxillary elastics were used in orthodontic treatment. The subjects included ten adults, seven males and three females between 23 and 28 years of age. All subjects had normal Class I occlusion with no signs or symptoms of temporomandibular disorder. The changes were recorded with and without intermaxillary elastics using the K6-I diagnostic system. Class II elastics induced the incial point at the rest position of the mandible to move backward. The activities of the masseter muscle increased with intermaxillry elastics when the mandible was at the rest position and in centric occulusion. These resuits suggested that the force of intermaxillary elastics can affect the activity of the masseter and the temporal muscles.

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We investigated the influence of masseter muscle fatigue on motor evoked potentials (MEPs) using transcranial magnetic stimulation (TMS). A double cone coil driven by a Magstim Model 200 magnetic stimulator was placed on the skull overlaying the right temporal area. The stimulus intensity was set to 50% maximum output. Two experiments were carried out with continuous (Exp1) and periodic (Exp 2) voluntary contractions. Two types of MEPs were measured. One was in the ipsilateral masseter muscle with short latency (about 3.0 msec) as Root MEPs (R-MEPs) and the other was in the contralat eral masseter muscle with long latency (about 7.0 msec) as Cortex MEPs (C-MEPs). There were no changes in the latency of the R-MEPs or the C-MEPs during either experiment. Continuous voluntary contraction decreased the amplitude of both MEPs in Exp 1, while the periodic voluntary contraction only decreased the amplitude of the C-MEPs. These findings indicated that the central fatigue was evaluated in the observation of differences of the amplitude between the R-MEPs and C-MEPs by using the TMS.

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We investigated the relationship between emotional stress and autonomic nervous response during gingival infiltration anesthesia. Twenty-four healthy subjects were divided into two groups that group consisted of six low dental anxiety subjects and six high dental anxiety subjects. A dental health questionnaire was used to determine the anxiety of the subjects before the experiment. For both groups the dentist administering the gingival infiltration anesthesia was changed just before administration. One group was informed this change would be made, and the other was not. Tonometry systolic blood pressure (SBP) and heart rate (HR) were measured continuously by a monitoring system (BP-508, COLIN, Aichi-ken, Japan) in all subjects. The average and coefficiency of variation (CV) was calculated for SBP and HR for eight periods of 30 seconds each during the experiment. The average SBP and HR were also calculated for twelve periods of 3 seconds each during administering the anesthesia. The results were compared by using repeated measure ANOVA. We found that anxiety induced by the change of dentist influenced SBP and HR more among the patients who were not informed of the change. This suggests that it is important to inform the patient of procedural changes he does not anticipate.

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Swallowing of water was observed continuously from the oral phase to the pharyngeal phase in 8 adult males with no perceived swallowing difficulty, we simultaneously recorded mandibular movements and swallowing pressures in the oral cavity and pharynx during a single swallow and a continuous swallow, and made functional assessments of the swallowing. We found that during a single swallow, the time lag between the oral and laryngeal phases was reduced as the volume increased, and that the middle pharyngeal pressure peaked before the maximum oral pressure. When a single swallow was compared with a continuous swallow of approximately the same volume, the values of various parameters, tended to decrease with the latter. This was especially true for the time lag of the mandible. From these results, we found that the two swallowing patterns have their respective temporal characteristics, and that there is coordination between mandibular movements and swallowing pressures. The simultaneous measurement of mandibular movements and swallowing pressure may be useful in the assessment of swallowing.

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Phosphate-bonded investment materials are most frequently used for casting pure titanium because of their compatibility, ease of manipulation, and reasonable price. However, a reactive layer forms on the surface of CP titanium when cast in phosphate-bonded investment materials. The magnesia transfer process of casting was devised to improve the reactive layer of CP titanium denture bases cast with phosphate-bonded investment, We compared various properties of coating samples used with the magnesia transfer process with those of control samples made with a conventional investing method. We found that the surface of the molds contained coating materials when the transfer process was used. A small amount of residual investment was observed on the coating samples removed from the mold. A reactive layer was observed in the control samples when the microstructure was observed. An electron probe microanalyzer (EPMA) was used to determine distribution of various elements in the superficial layer of the castings. However, this layer was redused in the samples that were coated. These results suggest that it is possible to improve the reactive layer of CP titanium casting plates using phosphate-bonded investments when the magnesia transfer process of coating is used.

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We developed a detection system for human beta actin mRNA, telomerase RNA and granzyme mRNA using a single section of human gingival tissue, and discussed the relationship between immunohistochemical staining of NK and killer T cells and RNA expression. One 4μm frozen section and one 4μm paraffin section of human gingiva were examined by RT-PCR and immunohistchemical staining. RT-PCR analysis of the three RNAs was accomplished by appropriate combination of the design and selection of primers. Actin and telomerase were strongly detected in all sections examined irrespective of the degree of inflammation in the gingival tissue, although expression of granzyme depended on the extent of inflammation in the epithelial region. Samples with stronger inflammation had greater granzyme activity. Intraepithelial lymphocytes had the morphology of large spindle or round cells similar to that of epithelial cells and macrophages.

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Ameloblastoma is an odontogenic tumor and probably one of the most controversial neoplasmas. Although the recurrence rate is high, the tumor has little capacity for metastasis. We investigated five cases of monolocular ameloblastoma to determine whether telomerase activity could be observed in the immortal cell lines and cancer cells by using a polymerase chain reaction (PCR) based (TRAP) assay. Expression of telomerase activity was observed uniformly in all of the ameloblastomas. Analysis using reverse transcription PCR (RT-PCR) showed that hTERT, hTER and hTEP 1 mRNA were expressed in all cases. Matrix metalloproteinases (MMPs) are a family of related enzymes with the combined ability to control essentially all components of the extracellular matrix, including development, wound healing, tissue resorption, and cancer metastasis. To determine the biological characteristics of ameloblastoma, we investigated MMP-1, MMP-3 and MMP-9 mRNA, which are involved in bone resorption and metastasis, using RT-PCR. Although expression of MMP-1 mRNA was observed in three cases, and MMP-3 mRNA was observed in four cases, MMP-9 mRNA was not expressed in any. These results suggested that the biological characterization of monolocular ameloblastoma was ability of immortalization and week resorption of bone, that is the reason why a few ameloblastoma cells remain in trabecular bone to be high recurrence.

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The topical application of antibiotics in periodontal pockets has been widely used for treatment of periodontal disease. However, there are no clear guidelines as to the ideal frequency and duration of application. We clinically examined the effects of administering Periocline^【○!R】in combination with scaling and root planing (group B) as compared with scaling and root planing alone (group A). We found that with the exception of the plaque index, there was more improvement in group B than in group A throughout the observation period.

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The observations in Part 1 of this study were done at Osaka Dental University, while the patients of this study (Part 2) were seen at Beijing University. We clinically examined the effects of administration of Periocline^【○!R】in combination with scaling and root planing (group B) as compared with scaling and root planing alone (group A). We found that with the exception of the plaque index, there was more improvement in group B than in group A throughout the observation period. The results of this study were almost identical to those of Part 1.

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When we take Oriented Tomogram, We beforehand take the submental vertex (SMV), and we calculate the measurement values from it. We examined the correlation between that measurement values and the measurement values of the difference of the condylar head position that the clinical CR bite called power centric bite and the CO bite in centric occlusion make. The subjects were 109 patients (25 males and 84 females) who wished to have orthodontic treatment with an average age of 17.3 years (8〜36 years old). In result, we found that the condyle angle and offset distance had a significant correlation with the y-axis value of the condylar position indicator (CPI). This measurement values of SMV show the big value in the patients with temporomandibular disorders. On the other hand, it suggested that temporomandibular disorder is related to dislocation of condylar head because the value of the Y-axis of CPI is related to subluxation of condylar head. These result suggest that CPI screening shoud be done for patients with temporomandibular joint problems before starting orthodontic treatments.

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Panoramic radiographs often show a dome-type uniform shadow in the maxillary antrum that is a retention cyst that occurs in the mucosa. I investigated the clinical, biochemical and histological aspects of this lesion. In 1397 cases, I observed shadows that seemed to be hydroceles in the maxillary antrums of 89 cases (6.4%), 8 cases of which were bilateral. Since 47 of the cases were males and 42 females, there did not seem to be a significant gender difference. Thiny of the cases were on the left side, 51 on the right and 8 were bilateral. sixty-four (66%) of the cases were asymptomatic. The patients complained of buccal region discomfort in 31 (32 %) of the cases, heavy-headedness in 8 cases (8%) and tooth discomfort in 4 cases (4%). Neither dental infections and nasal allergies seemed to contribute to development of this cyst. Endoscopic examination of 65 cases revealed that 48 (74%) showed a large second aditus at meatus nasi medius and that a hydrocele could be observed in the maxillary antrum in 31 (48%) cases. there was no correlation between a large second aditus and the size of the hydrocele. A positive reaction of the Rivalta and Runeberg test revealed that the contents of the solution in the hydrocele was exudative. Bacterial examinations were all negative. Histopathological examination revealed that the maxillary antrum mucosa was normal, and that the hydrocele contained serous fluid that poored in connective tissue.

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We attempted to isolate and purify a bacteriocin from Streptococcus mutans Rm-10 cells which have a stationary phase in the growth curve. The bactericidal substance was isolated from the supernatant fluid and purified by arginine Sepharose 4B, gel filtration, sucrose density gradient ultracentrifugation and lysine Sepharose 4 B. In SDS-PAGE analysis of the purified bacteriocin (N-ABC), only one band was recognized at a molecular weight of approximately 34 kDa, where antibacterial activity against the indicator strain was displayed. N-ABC was a protein-carbohydrate complex, and was found to be rich in the sugars glucose and rhamnose, and in the amino acids alanine and lysine. These results indicate that Streptococcus mutans Rm-10 used in this experiment produced a bacteriocin different from two previously reported bacteriocins.

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We attempted to oharacterize a purified bacteriocin (N-ABC) isolated from Streptococcus mutans Rm-10. N-ABC was stable to heating at 120℃ for 10 min and under acidic pH conditions. However, the exposure of N-ABC to pH 11.0 resulted in complete loss of the activity. It was partially destroyed with trypsin, pepsin, papain, α-chymotrypsin, β-galactosidase, α-galactosidase and endo-β-galactosidase. The bacteriocin showed a relatively narrow spectrum of activity against Streptococcus mutans strains. N-ABC killed Enterococcus faecalis ODU in a dosedependent manner by a bactericidal mode of action. These results indicate that this bacteriocin is different from two bacteriocins previously reported by Muramatsu.

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We did immunohistochemical examinations of the cell growth factor BrdU, cyclin D1 and the cell adhesion molecular P-cadherin (P-CD) during carcinogenesis in the tongue. In normal cells and those with hyperkeratoosis, BrdU and cyclin D1 localized only in the nuclei of basal cells, and P-CD was expressed only in the basal cell membrane. In dysplasia, BrdU was expressed in the basal cells, and cyclin D1 extended to a wide area, including the basal cell layer and spinous cell layer. P-CD was expressed from the basal cells to the spinous cell membrane. In carcinomas, BrdU and cyclin D1 immunoreactive cells were localized in the peripheral layer of the tumor nests. P-CD was expressed in cancer cells except in the tumor nests. The expression of cell growth factor and P-CD corresponded to the development of carcinogenesis.

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We examined flow cytometry and immunohistochemical staining specimens in order to investigate the relationship between cellular immunity and the process of carcinogenesis. The appearance of CD4 positive (CD4^+) and CD8 positive (CD8^+) cells increased in peripheral blood and tongue intraepithelial lymphocytes four weeks after administration of 4-nitroquinoline 1-oxide (4NQO). Histological changes of hyperplasia and dysplasia increased CD4 cells significantly, compared with normal peripheral blood and and tongue intraepithelial lymphocytes. In histological changes of dysplasia and carcinoma, the appearance of CD8^+ cells increased significantly compared with peripheral blood and tongue intraepithelial lymphocytes in the normal comrol group. Compared with normal cells, NKR-P 1 A positive and CD3 positive (NKT^+ like cells) cells were increased significantly in the peripheral blood and tongue intraepithelial lymphocytes when there was cancer. The expression of cellular immunity corresponded to histological changes during the development of carcinogenesis. These findings suggest that the development of 4NQO -induced carcinogenesis used in this study may mediate cellular immunity. We believe that changes in cellular immunity during carcinogenesis are accomplished by cell suppression factors such as the carcinogenesis factor.

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We developed a highly sensitive detection system for human papillomavirus (HPV) in order to elucidate the localization of HPV in formalin-fixed, Paraffin-embedded sections from squamous cell carcinoma (SCC) using in situ polymerase chain reaction (PCR) primers (MY 09 and MY 11). Various parameters such as thermal cycler apparatus, pepsin treatment, PCR reagent, stringency, PCR reaction condition, and immunohistochemistry were examined. Under optimal conditions, in situ PCR analysis revealed the specific presence of HPV DNA in all cases of SCC and their localizations were observed in the nuclei and cytoplasms of koilocytes, SCC cells and epithelial cells as forms of integrated HPV DNA and episomes. These results suggest that the establishment of a highly accurate detection system for HPV will be very useful in carcinogenesis research.

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