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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健康日本21が示されて以来、多くの地域において健康づくり計画の策定が進んでいる。これらの計画には,達成度評価のために多種の数値指標が設定されている。しかし,小地域においては,数値指標が不規則に変動するため,経年的動向を見たり,地域間比較が困難である。う歯有病者率も同様な問題を抱えている。近年,ベイズ推定法がその解決策として法目されてきている。本研究では,市町村のう歯有病者率推定にベイズ・モデルを応用し,その有効性を検証した。その結果,ベイズ推定法がう歯有病者率においても数値の変動を抑制できることが示された。また,標準誤差率による分析から,その誤差調整作用が人口の不均等によって生じる偶然誤差の抑制によるものであり, 200人以下の標本サイズで顕著であることが分かった。以上から,ベイズ推定法が歯科保健分野においても有効な手法であることが確認された。

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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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固形腫瘍の増殖は腫瘍細胞に由来する増殖因子によって新生される血管に依存することが明らかになり,その結果血管の新生を阻害することにより,抗腫瘍効果を期待する薬剤が開発されてきた。本実験で用いたE7820は,血管の管腔形成を抑制する新しい血管新生阻害薬である。一方,癌治療薬は,ほとんどが局所での有効濃度を考慮して高濃度で経静脈的に,または大量を経口的に投与されており,様々な副作用を引き起こす可能性が考えられる。そこでわれわれは薬剤を少量で,しかも高濃度の状況を得るため,腫瘍塊中心部に薬剤を直接注入する投与方法を用いて検索した。ウサギ舌近縁部にVX2癌細胞を移植し,移植後3日目より隔日で4回,腫瘍塊中心部にE7820(10mg/ml)をそれぞれ100μl注入した。最終投与の翌日に屠殺し舌を摘山,凍結包埋し,10μmの連続切片を作成した。切片は5'-Nase染色を施し,コンピュータに二次元画像として入力,リンパ管を抽出後,三次元再構築し観察した。またリンパ節転移の有無に関しては,深頸リンパ節を摘出後,連続切片標本にH-E染色を施し,病理組織学的に検索した。腫瘍の体積は,対照群と比較して約1/4であり著明に腫瘍の増殖が抑制された。また対照群では,全例に深頸リンパ節への転移が認められたのに対し,薬剤投与群では,80%に転移が認められなかった。腫瘍周囲のリンパ管は,腫瘍外郭200μmの範囲には, 5'-Nase陽性のリンパ管が完全に消滅しており,毛細リンパ管の新生は認められなかった。腫瘍の増殖は本薬剤により抑制されたと考えられた。また薬剤投与により,腫瘍外郭200μmの広範囲のリンパ管が消失したことから,癌細胞がリンパ管源流に到達する確率が低くなり,リンパ節転移が抑制されたと考察した。E7820の腫瘍内投与により,少量の薬剤投与量で著効を認めたことから,本薬剤の有効性と,腫瘍内投与による臨床応用の可能性が示唆された。

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歯科矯正治療についての知識や情報が一般的に知られ,歯の健康に対する意識や審美的意識の向上により,なかでも成人女性の矯正治療を希望する割合は年々増加する傾向にある。しかし,女性は40歳をさかいに骨密度が減少すると言われている。骨粗鬆症と歯槽骨の関係に関してはいくつかの報告があるが,歯の移動に関する報告はほとんどない。本研究では,12週齢の正常ラットと骨粗鬆症ラットの臼歯部に,矯正治療用ゴムリングを挿入し歯の移動を行った。歯槽骨の組織学的観察は一次抗体にTGF-β1抗体を用いた免疫組織染色法にて行った.その結果,骨粗鬆症であっても矯正力でTGF-β1は誘導され,歯槽骨骨梁の骨芽細胞ならびに破骨細胞に作用し,骨形成と骨吸収の両作用を活性化することにより歯槽骨の改造を引き起こすが,骨粗鬆症群では骨吸収の亢進と骨形成開始の遅延が生じている可能性が示唆された。

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本研究の目的は,各個人に適した歯列弓形態を考えるための基礎資料として,日本人成人における歯列と□蓋および頭蓋との関走既を明らかにすることである。矯正治療経験のない日本人成人男子168名(平均年齢25歳5か月)を対象に,歯列模型から歯列弓の幅径と長径,歯槽基底部の幅径と長径,□蓋の深さと容積,生体から頭長および頭幅を計測した.得られた計測値については, Pearsonの相関係数を算出し,さらに相関係数の検定を行って比較検討した。結果は以下の通りであった。1.上顎歯列弓長径と第一大臼歯部の歯列の幅か大きいほど,口蓋が深く,容積が大きい傾向が認められた。2.頭長が大きいほど,上顎第一大臼歯部の歯列の幅が大きい傾向が認められた。3.頭幅が大きいほど,上下顎第一大臼歯部の歯列の幅が大きい傾向が認められた。4.上顎前突は反対校合より頭長が大きい傾向が認められた。以上のことから,歯列は口蓋の形態および頭蓋の大きさと関連があることが示され,歯を排列する際には,歯と歯槽基底部の大きさの調和を考慮するだけでなく,頭蓋の大きさも考慮する必要性が示唆された

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