Nitric oxide (NO) has been implicated in macrophage-mediated cytotoxicity against various pathogens and may play a role in persistent or latent infections. However, its overproduction induced by some bacterial antigens could cause damage to host tissues and cellular DNA. We have previously reported a novel bioactive antigen (SAA) from a culture supernatant of Streptococcus anginosus that induces NO synthesis by murine peritoneal exudate cells (PEC). In this study, I performed a further assessment of SAA-induced NO synthesis by PEC. The results indicated that SAA stimulated the macrophages in PEC as well as a murine macrophage cell line, J774.1, to produce NO with the accumulation of inducible NO synthase (iNOS) mRNA. SAA also stimulated the non-macrophage cells in PEC to produce IFN- γ, however, the endogenous IFN-γ was not involved in the SAA-induced NO synthesis and iNOS mRNA accumulation by the macrophages. Further, phosphorylation of both p38 and ERK1/2 mitogen-activated protein (MAP) kinase was observed in macrophages by the stimulation with SAA but p38 MAP kinase pathway could solely correlate with SAA-induced NO synthesis. Thus, the present results suggest that S. anginosus, by a bioactive antigen, SAA, could stimulate macrophages through p38 MAP kinase nathwav to induce NO svnthesis without heln of the endogenous TFN-γ.

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During the tooth movement, an optimal compressive force (orthodontic force) must be applied to the periodontal ligament. In order to achieve an optimal force, it is important to understand the changes of blood flow and the vascular networks on the pressure side of the periodontal ligament. However, there are few published reports about the long-term daily changes of the blood flow in the vascular networks of the periodontal ligament. We studied the daily changes of the blood flow in the pressure side of the periodontal ligament of the dog mandibular canine using a microcirculation analyzer, which enables to discriminate between blood flow of arteries and veins based on a cross-correlation coefficient between laser speckle and pulse signals. We measured the blood flow in the pressure side of its periodontal ligament through a thin cavity wall. The following results were obtained ; 1. The microcirculation analyzer and the cross-correlation coefficient that we used in this study could measure the changes of arterial and venous blood flow on the pressure side of the periodontal ligament. 2. The overall blood flow after the force application decreased immediately. 3. The blood flow after the force application increased on day 1 especially in the arteries. 4. The arterial and venous blood flow recovered after 3, 7, and 14 days of the force application to the same levels as under non-pressurized conditions.

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Angiogenesis is associated with tumor growth and metastasis in patients with solid tumors, including those of the head and neck. Nitric oxide (NO) production may contribute to these processes. NO production in the tumor depends on the iNOS. 1400W is the most selective iNOS inhibitor and strongly prevents NO production by the iNOS. In the present study, the effect of 1400W on tumor-induced angiogenesis and tumor proliferation was examined using a weakly immunogenic squamous cell carcinoma of the WHT/Ht mouse. 1400W inhibited the angiogenesis induced by the murine tumor dose-dependently, and the number of blood vessels orientated towards the intradermal tumor was maximally reduced by 62.5% compared to the control. In the tumor proliferation assay, 1400W significantly inhibited proliferation of the subcutaneously inoculated tumor, and reduced the tumor volume by 60.0% (20mg/kg) and 75.7% (lOmg/kg) compared to the control. Subcutaneously inoculated tumors were observed by the Immunohistochemistry and Western blot analysis, and iNOS and VEGF expression was lowered with administration of 1400W compared to the control. These results suggest that 1400W has significant inhibitory activities against in vivo tumor-induced angiogenesis and proliferation of murine squamous cell carcinoma.

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Endostatin, a fragment of collagen XVIII, is a potent antitumor protein, but the mechanism of its action is not yet clear. There is little report concerning antitumor action of endostatin on squamous cell carcinoma occurring in the head and neck. This study examined the antitumor effect and anti-angiogenesis effect of endostatin on murine squamous cell carcinoma, and the effect on the cell proliferation and tube formation of normal human umbilical vein endothelial cell (HUVEC). As a result, endostatin induced reduction of murine squamous cell carcinoma growth and that of tumor angiogenesis. Moreover, endostatin inhibited cell growth and tube formation for HUVEC. In this time, the ratio of S-phase cells was decreased by endostatin-treatment. These findings suggested that the antitumor effect of endostatin was caused through the inhibition of angiogenesis, which was induced by the decreasing of S-phase endothelial cells.

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Though it has been reported that osteoblasts perceive extracellular calcium levels and regulate the differentiation and function of osteoclasts, the details of its mechanism of calcium perception or of its genetic expression system mostly remains unclear. In the present study, therefore, the influence of a high-calcium environment on osteoblasts was examined from the expressions of RANKL and CaSR mRNAs as well as from the formation of osteoclasts following cocultures. The identification of CaSR was made by the immunohistochemical staining method using rat alveolar bones with experimental tooth movement. On the third and seventh days after manipulation, both osteoclasts and osteoblasts showed CaSR positive reaction on the compressed side of the alveolar bones. On the other hand, CaSR positive reaction was observed only for osteoblasts on the tension side of the alveolar bones, though the reaction was weak. In the subsequent experiment using an osteoblast-like cell line (SaOS-2 ), PT-PCR was performed by changing the calcium concentration in the cultured solution from 1.8 to 2.5, 10 and 40 mM and further by treating with 0.1 and 1.0 μM of ionomycin. The PCR products of RANKL and CaSR mRNAs were then analyzed. The expressions of RANKL and CaSR mRNAs decreased in a calcium concentration dependent manner. When SaOS-2 cells were treated with ionomycin, RANKL mRNA expression increased in a dose dependent manner. However, CaSR mRNA expression increased at 0.1 μM ionomycin but showed almost no difference at 1.0 μM as compared with the untreated level. In order to examine the effect of calcium on the differentiation of osteoclasts, SaOS-2 cells were cocultured with a human myeloid leukemia cell line (HL-60). Total RNAs were extracted after SaOS- 2 cells pretreated with calcium were cocultured with HL-60 and after SaOS-2 cells pretreated with lα,25(OH)_2D_3 were cocultured with HL-60 under the presence of calcium, and the amount of tartrate-resistant acid phosphatase (TRAP) mRNA expression was examined by RT-PCR, Simultaneously, the number of osteoclasts that appeared was counted. As a result, the expression of TRAP mRNA increased in a dose dependent manner up to the calcium level of 2.5 mM but decreased at levels above it. The number of osteoclast-like cells showed a similar pattern to the expression of TRAP mRNA. In the case of SaOS-2 cells pretreated with 1α,25(OH)_2D_3, the TRAP mRNA expression increased in a dose dependent manner up to a calcium level of 10 mM but the expression at a calcium level of 40 mM decreased to a similar level observed at 1.8 mM. From the results mentioned above, it was suggested that a high extracellular calcium level in osteoblasts suppresses the expression of RANKL through CaSR which exists in the cell membrane and further suppresses the differentiation of osteoclastic precursors to osteoclasts.

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Many regional health projects have been planned or implemented since Health Japan 21 was stipulated. In these projects, many numerical health indicators have been established to evaluate achievement. In small areas, however, numerical indicators are difficult to compare over years or between regions due to data fluctuations. This statistically problematic fluctuation can be seen in the dental caries prevalence rate. Recently, the Bayesian method has received attention as a way to overcome this problem. In this study we attempted to assess the utility of the Bayesian model in estimating caries prevalence in municipalities. The results show that the Bayesian approach can stabilize the fluctuations in the rates. Moreover, analysis using the ratio of standard error suggests the power of data adjustment by the Bayesian method results from reduction in random error due to population heterogeneity, and the results are clearer in sample sizes of 200 or less. Thus this study confirmed that the Bayesian method is very useful in assessment of dental health.

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Antigen I/II protein is a cell surface protein antigen of Streptococcus mutans and is implicated in the adhesion mechanism to tooth surfaces. We have identified the antigen I/II homologous gene (paaA) from Streptococcus cricetus, a member of mutans streptococci. To clarify the mechanism of paaA expression, we sequenced the flanking regions of the paaA gene utilizing the gene-walking method in this study. In the upstream region of paaA, three homologous genes found in the corresponding region of Streptococcus sobrinus were identified. One of the corresponding genes in S. sobrinus was par, which has been characterized as a transcription represser of the antigen I/II (spaA) gene. Therefore, the homologous gene in S. cricetus could have a role in transcription of paaA. In the downstream region of paaA, the paaA homologous gene was found and designated as paaB. The paaB gene was interrupted by a novel insertion sequence element (ISScr1), a member of the IS982 family. Southern hybridization analysis of S. cricetus par indicated that no gene homologous to S. cricetus par was found in the oral streptococci used in this study. Furthermore, the downstream region of antigen I/II (spaA) in S. sobrinus was sequenced using the gene-walking method. No similar gene to antigen I/II gene was found in the region. It was suggested that the paaA might be regulated by the par in S. cricetus.

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Anti-angiogenic agents exert strong inhibitory effects on tumors, and their inhibitory effects on metastasis to regional lymph nodes have also been reported. We confirmed the inhibitory effects of an anti-angiogenic agent, E7820 (provided by Eizai Co., Ltd., Japan), on the growth of VX 2 cancer in a rabbit tongue. We examined the changes in the lymphatic architecture around the tumor. E7820 (O.1ml of 10mg/ml) was injected into the center of a tongue tumor in rabbits every other day for a total of 4 injections starting at 3 days after the transplantation of VX 2 cancer cells. One day after the last injection, the rabbits were sacrificed. The tongue was excised, and serial frozen sections were made. The sections were stained with 5'-Nase, and their 2-dimensional images were fed to a computer. The lymphatic structure was extracted on the computer, and its 3-dimensional image was constructed and examined. 5'-Nase-positive lymphatic vessels were abolished in the region 200μn around the border of the tumor, and no genesis of the lymphatic capillaries was noted. The growth in tumor volume was inhibited to one-fourth that of controls, and metastasis to the lymph nodes was limited to one-fifth of the control.

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With recently prevailed knowledge and information on orthodontic treatment as well as improved awareness about dental health and aesthetic concerns, the proportion of adult female orthodontic patients has tended to increase yearly. The decreases of bone density in females forty and older are known. Although several reports have investigated the possible relationship between osteoporosis and the alveolar bone, we could not find a report concerning the tooth movement in relation to this disease. In this study, we confirmed that tooth movement was experimentally induced by inserting a gum ring for orthodontic treatment onto the molar site of normal and osteoporotic rats 12 weeks postpartum. The histological study of the alveolar bone was performed with immunohistological staining using TGF- β 1 antibody as a primary antibody. As a result, we found that TGF-β 1 is induced by orthodontic force and acts on osteoblasts and osteoclasts in the alveolar bone and ultimately induces a reconstruction of alveolar bone through activation of both bone formation and resorption. This also occurred even in the case of osteoporosis, however, an enhanced bone resorption and delayed initiation of bone formation was suggested in the osteoporotic group.

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The purpose of this study was to elucidate the relation of dentition to the palate and the cranium in Japanese adults to serve as fundamental material for considering the morphology of dental arch well fitted to each person. In 168 Japanese male adults with no history of orthodontic treatment (mean age of 25 years and 5 months), the dental arch length and width, basal arch length and width, palate depth and volume as well as biometric head length and breadth were measured using a set of dental casts. From the determined values thus obtained, the correlative coefficient was calculated and tested for comparison. The results of this study reveal as follows : 1. The maxillary arch length and the width of inter-1 st molars tended to become larger with more deepened palate, indicating a tendency of larger volumes of the palate. 2. The larger the head length was, the larger the width of inter-maxillary 1 st molars became. 3. The larger the head breadth was, the larger the width of inter-1st molars of both arches became. 4. The maxillary protrusion tended to have a larger head length as compared with the mandibular protrusion. From the results mentioned above, the dentition was revealed to closely relate to the palate and the cranial size, and it was thus suggested that not only the harmonized size of the tooth and alveolar base but also the cranial size should be considered when the teeth are aligned.

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