The objective of this study was to establish an X-ray radiographic evaluation method of regenerated bone by comparison of X-ray photograph, bone mineral content, and bone morphometry by microfocus X-ray CT in a bone regeneration model using an acidic gelatin disc (AGD) containing a sustained release basic fibroblast growth factor (bFGF) system. A defect 6 mm in diameter was made in the cranium of 36 Wistar rats aged 16 weeks (6 animals per group). bFGF (1.0 and 10.0 μg) and physiological saline (control) were added to AGD with a water content of 81.8 ± 0.2%, and the discs were implanted in the bone defects. The animals were sacrificed after 4 and 8 weeks, and evaluated. Regenerated bone was evaluated by X-ray photodensitometry using an aluminum step wedge and imaging plate JP) and based on the CT concentration (pixel concentration) and volume on microfocus X-ray CT. Photodensitometry showed that bFGF promoted bone regeneration with time in a concentration-dependent manner. Microfocus X-ray CT also detected similar changes in the pixel concentration in the regenerated region and the regenerated bone volume, clarifying that bFGF promoted bone regeneration. The relative aluminum concentration measured by photodensitometry and the pixel concentration measured by microfocus X-ray CT were correlated. It was revealed that microfocus X-ray CT can non-invasively evaluate regenerated bone, and is capable of quantitative and 3 -dimensional analyses. These findings suggested that microfocus X-ray CT is useful for the assessment of regenerated bone in the clinical application of regenerative medical methods.

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To elucidate the effects of various chemical mediators, which are considered to appear in inflammation, on vascular smooth muscle, annular specimens of porcine lingual arterial smooth muscle were prepared, and divided into specimens denuded or undenuded of vascular endothelium. These specimens were attached to the thermostat incubator of an intracellular calcium ion concentration measurement unit, stimulated with 40 mM KCl, noradrenalin (NA), or U46619, followed by administration of acetylcholine (ACh) or bradykinin (BK), and the isometric contractile tension generated and fluorescence intensity ratio were simultaneously measured ; the following conclusions were drawn. 1. The inhibition by ACh or BK of NA-, high KCl-, or U46619-induced contraction was dependent on the presence of vascular endothelium, suggesting the involvement of a decreased [Ca^<2+>]_i concentration in the contraction inhibition. 2. It was suggested that the inhibition of high KCl-induced contraction by ACh or BK was weaker than that of receptor stimulation-induced contraction. 3. The administration of BK showed biphasic changes in U46619-induced contractile tension and [Ca^<2+>]_i.

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To establish effective regenerative periodontal therapy, a two-dimensional quantitative assay for regenerated alveolar bone in rats was developed, and the regenerative activity of Emdogain^<(R)> (EMD) as well as collagen sponge (CLS) and acid-polyglycolic gelatin sponge (GEL) was evaluated. After anesthetization of a Wistar rat, alveolar bone defects were prepared at both palato-distal sides of the maxillary first molars. The biomaterial was topically applied to one defect, and the other quadrant defect without application was designated as a control. One to 8 weeks after application, the animals were sacrificed, and the new bone formation (NBF) on the bone samples was measured by a newly-developed two-dimensional scale. The NBFs were observed at Week 1 and then gradually increased in all sites. The NBF in EMD-applied sites at Week 1 was significantly lower, and those in GEL-applied sites at Weeks 4 and 5 were significantly higher than those in controls (all p<0.05). However, the regenerated bone densities assayed by X-ray micro-CT tomograms in EMD-applied sites were significantly higher than the control. The present findings indicate that the developed assay could be a useful method for evaluation of the regenerative activities of biomaterials, and that EMD could induce the regeneration of alveolar bone with relatively higher density.

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To elucidate B cell activation induced by Porphyromonas gingivalis, the lipopolysaccharide (LPS)-induced B cell proliferation and tyrosine phosphorylation in B cells from C 3 H/HeN and LPS-hyporesponsive C 3 H/HeJ mice were examined. P. gingivalis LPS induced cell proliferation of both C 3 H/HeN and C 3 H/HeJ B cells, accompanied by the induction of tyrosine phosphorylation of selected proteins that included 25 kDa protein (p25). In contrast, Escherichia coli LPS activated only C 3 H/HeN B cells to proliferate and to induce tyrosine phosphorylation of p25. In order to characterize p25, P. gingivalis LPS-activated B cell lysates were separated by two-dimensional gel electrophoresis (2D-PAGE). Two out of 8 spots of the candidates of p25 separated by 2D-PAGE were identified as Ran (Ras-like nuclear protein) by peptide mass fingerprinting with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Western blotting analysis revealed that Ran existed as at least 4 spots in B cells with and without LPS stimulation. However, total amounts and the amount of the most acidic spot of Ran apparently increased by P. gingivalis LPS stimulation. These results suggested that quantitative alteration and tyrosine phosphorylation of Ran are involved in P. gingivalis LPS-induced B cell proliferation.

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齲蝕の治療を行うにあたり,齲蝕部位の病理組織学的診断を行うことは実際に不可能である。そのため,実際に行われている臨床診断の精度は明らかでない。本研究の目的は,ふだん行われている診査方法による臨床診断の信頼性,および術者間における診断の変動についてin vitroで調べることである。臨床診断にはエアーシリンジを用いた視診,探針による触診,それにエックス線診が使われた。試験には抜去歯が用いられ,臨床診断とコンタクトマイクロラジオグラム(CMR)による最終診断が比較された。レーザー型齲蝕検出装置であるDIAGNOdent^<TM>も客観的に臨床診断を行う方法として検討を行った。その結果,臨床診断のうち81%がCMRによる最終診断と一致した。4名の歯科医師の特異度はC_1で0.8から1.0,C_2で0.63から0.88だった。敏感度はC_1で0.5から0.83,C_2で0.88から1.0だった。Kappa係数は0.45から0.66だった。DIAGNOdent^<TM>と最終診断の一致率は50%だった。結論として,術者間の再現性は必ずしも高くはなく,共通の診断方法を使った場合でも術者によって臨床診断は変化するように思われた。したがって,臨床診断と最終診断は81%が一致したが,より正確な臨床診断を行うためにはさらなる研究が必要と思われる。一方,単独のDIAGNOdent^<TM>計測値は現在のところ,臨床診断ほどには信頼できないものだった。

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当科では,従来から機能温存,形態温存を目的に抗癌剤の動脈内投与と放射線療法の同時併用療法を行い,その有用性を報告してきた。しかし,そのなかで治療後の治療効果判定の困難さが問題点として残された。そこで1993年から2-deoxy-2-fluoro[¹⁸F]-D-glucoseを用いたpositron emission tomography(¹⁸FDG-PET)による治療効果判定を加え検討を行っている。今回は,下顎歯肉癌に対して本療法後,¹⁸FDG-PETによる治療効果判定および治療後の再発,転移の診断に用い,一次治療時に外科療法を回避し,機能温存,形態温存が可能となり治療後のQOLの向上が得られた経過良好な1例を経験したので報告する。患者は50歳女性で,下顎歯肉扁平上皮癌(T4NOMO)と診断され,治療目的に当科を紹介来院した。初診時の¹⁸FDG-PETの所見では,腫瘍放射能比(standardized uptake value,SUV)は50分値12.35±0.10,60分値13.89±0.49と上昇を認めた。入院後,浅側頭動脈カニュレーションを行い,bleomycin(総量60mg),methotrexate(総量200mg)およびcisplatin(総量100mg)の3剤併用化学療法と放射線療法(Linac総量40,25Gy)を行った。治療後臨床的に腫瘍は縮小,消失し,¹⁸FDG-PETによる所見でもSUVは50分値3.30±0.15,60分値3.58±0.14と明らかな上昇は認めずCRと判定し,この結果,外科療法を行わず,維持療法を行った。治療後2年6か月後に行った¹⁸FDG-PETによる所見でもSUVは50分値1.91±0.16,60分値1.90±0.02と低値を示し,現在まで,再発,転移の徴候はなく,経過良好である。

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After investigating 430 teeth of 346 patients having infected root canals after restorative procedures in four private practices, the following conclusions were obtained. 1. Upper and lower first primary molars were most susceptible to infected root canals. Upper second primary molars had the lowest susceptibility to infected root canals among all primary molars. 2. The peak age for obtaining restorative treatments was youngest in upper primary central incisors and it was 2 years. The highest peak age was 4 years in upper second primary molars. 3. In either restoration, more than half of the cases were treated without pulp capping. 4. The peak age for incidence of infected root canals after restorations was 4 years in upper primary central incisors. In these restored teeth, the more distally teeth were located, the higher peak age was observed; therefore, the peak age for upper and lower second primary molars was 5 or 6 years. 5. The duration between receiving restorative procedures and incidence of infected root canals was mostly within 6 months in upper first primary molars. Nevertheless, in almost 50 % of the other primary teeth except for lower and upper second primary molars, infection of root canals occurred within 1 to 1.5 years. 6. One third of children having infected root canals after restorations had some systemic diseases. On the other hand, two thirds of children were uncooperative at the time of restorations. Above the results, it was revealed that deep caries requires pulp capping and close proximity to pulp should be taken into consideration during restoring teeth with thin tooth structure such as upper and lower first primary molars and upper primary central incisors. In such cases as treatments on uncooperative young children, it is suggested that provisional treatments should be performed first before providing final restorations.

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