Faculty Profiles - EKUNI Daisuke

Oxidative damage of rat liver induced by ligature-induced periodontitis and chronic ethanol consumption

Takaaki Tomofuji, Toshihiro Sanbe, Daisuke Ekuni, Tetsuji Azuma, Koichiro Irie, Takayuki Maruyama, Naofumi Tamaki, Tatsuo Yamamoto

ARCHIVES OF ORAL BIOLOGY 53 ( 12 ) 1113 - 1118 2008.12

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

DOI： 10.1016/j.archoralbio.2008.05.015

Relationship Between Periodontal Condition and Plasma Reactive Oxygen Metabolites in Patients in the Maintenance Phase of Periodontal Treatment

Naofumi Tamaki, Takaaki Tomofuji, Takayuki Maruyama, Daisuke Ekuni, Reiko Yamanaka, Noriko Takeuchi, Tatsuo Yamamoto

JOURNAL OF PERIODONTOLOGY 79 ( 11 ) 2136 - 2142 2008.11

Language：English Publisher：AMER ACAD PERIODONTOLOGY

Background: The relationship between systemic antioxidative status and periodontal condition has been investigated in epidemiologic studies. However, little literature is available with regard to the correlation between systemic reactive oxygen species and periodontal condition. The purpose of this cross-sectional study was to investigate the relationship between plasma reactive oxygen metabolites (ROM) and periodontal condition in patients in the maintenance phase of periodontal treatment.
Methods: Eighty-one subjects (mean age: 57.4 years) who had entered a periodontal maintenance program were examined for probing depth (PD) and clinical attachment level (CAL). Plasma levels of ROM and biologic antioxidant potential (BAP) were determined with a free radical electric evaluator.
Results: The plasma level of ROM was positively correlated to mean CAL (r = 0.281; P = 0.011) and percentage of teeth with CAL A mm (r = 0.236; P = 0.034), but not mean PD (r = 0.196; P = 0.080). Logistic regression analysis showed that subjects with ROM levels >400 Carratelli units (CARR U) had significantly higher mean CAL compared to subjects with ROM >400 CARR U after adjusting for age, gender, and the number of teeth present (P = 0.011). However, the plasma level of BAP was not significantly correlated with the periodontal parameters.
Conclusions: A positive association was found between plasma oxidative status and CAL in patients in the maintenance phase of periodontal therapy. A systemic increase in oxidative stress may influence the rate of progression of periodontal disease. J Periodontol 2008; 79:2136-2142.

DOI： 10.1902/jop.2008.080082

Relationship Between Periodontal Condition and Plasma Reactive Oxygen Metabolites in Patients in the Maintenance Phase of Periodontal Treatment International journal

Naofumi Tamaki, Takaaki Tomofuji, Takayuki Maruyama, Daisuke Ekuni, Reiko Yamanaka, Noriko Takeuchi, Tatsuo Yamamoto

JOURNAL OF PERIODONTOLOGY 79 ( 11 ) 2136 - 2142 2008.11

Language：English Publisher：AMER ACAD PERIODONTOLOGY

DOI： 10.1902/jop.2008.080082

アンケートによる歯周疾患スクリーニングの有効性

小山玲子, 玉木直文, 丸山貴之, 友藤孝明, 江國大輔, 山中玲子, 東哲司, 山本龍生

口腔衛生学会雑誌 58 ( 5 ) 557 - 557 2008.10

歯周炎モデルラットにおける歯肉酸化ストレス度・抗酸化力に対するビタミンC全身投与の効果

入江浩一郎, 友藤孝明, 江國大輔, 三部俊博, 東哲司, 丸山貴之, 玉木直文, 山本龍生, 森田学

口腔衛生学会雑誌 58 ( 4 ) 454 - 454 2008.8

Relationship between body mass index and periodontitis in young Japanese adults

D. Ekuni, T. Yamamoto, R. Koyama, M. Tsuneishi, K. Naito, K. Tobe

JOURNAL OF PERIODONTAL RESEARCH 43 ( 4 ) 417 - 421 2008.8

Language：English Publisher：WILEY

Background and Objective: Obesity has been implicated as a risk factor for several chronic health conditions. Recent studies have reported a relationship between obesity and periodontitis, but few studies have investigated this relationship in adolescents. The purpose of the present study was to investigate the relationship between body composition (i.e. body mass index and body fat) and periodontitis in university students in Japan.
Material and methods: Medical and oral health data were collected in a cross-sectional examination conducted by the Health and Environment Center of Okayama University. Students aged 18-24 years (n = 618), who were interested in receiving an oral health examination, were included in the analysis. The community periodontal index was used to assess periodontal status. Subjects with a community periodontal index score of 0-2 were considered as controls and those with a community periodontal index score of > 2 were considered to have periodontitis. Logistic regression analysis was used to estimate the association between body mass index and periodontitis.
Results: The body mass index of all subjects was < 30 kg/m(2). Age and body mass index were significantly associated with the community periodontal index. Logistic regression analysis revealed a 16% increased risk for periodontitis per 1-kg/m(2) increase in body mass index (adjusted odds ratio, 1.16; 95% confidence interval, 1.03-1.31; p < 0.05).
Conclusion: Body mass index could be a potential risk factor for periodontitis among healthy young individuals (i.e. those with a body mass index of < 30 kg/m(2)). It may be useful to include an evaluation of body mass index on a regular basis in university general and oral health examinations.

DOI： 10.1111/j.1600-0765.2007.01063.x

Relationship between body mass index and periodontitis in young Japanese adults

D. Ekuni, T. Yamamoto, R. Koyama, M. Tsuneishi, K. Naito, K. Tobe

JOURNAL OF PERIODONTAL RESEARCH 43 ( 4 ) 417 - 421 2008.8

Language：English Publisher：WILEY

DOI： 10.1111/j.1600-0765.2007.01063.x

Effects of ethanol consumption on periodontal inflammation in rats

K. Irie, T. Tomofuji, N. Tamaki, T. Sanbe, D. Ekuni, T. Azuma, T. Maruyama, T. Yamamoto

JOURNAL OF DENTAL RESEARCH 87 ( 5 ) 456 - 460 2008.5

Language：English Publisher：INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R

Studies suggest a correlation between ethanol consumption and periodontal disease. We hypothesized that elevated levels of blood reactive oxygen species following ethanol consumption may increase inflammation in periodontal tissue. Rats were divided into 4 groups (6-7 rats/group). Two groups were fed an ethanol-containing liquid diet, and 2 groups were fed a pair-fed control diet. In one of each dietary group, periodontitis was ligature-induced, while the other group was left unligated. Chronic ethanol feeding alone decreased the ratio of reduced/oxidized glutathione and increased 8-hydroxydeoxy guanosine and tumor necrosis factor (TNF)-alpha levels in the gingiva. Blood hydroperoxides were also increased. In ligature-induced periodontitis lesions, ethanol feeding enhanced polymorphonuclear leukocyte infiltration and TNF-alpha expression. The results suggest that chronic alcohol consumption increased periodontal inflammation, oxidative damage, and TNF-alpha production and had an additive effect on polymorphonuclear leukocyte infiltration and gingival oxidative damage, increasing the severity of periodontal inflammation in the ligature model.

DOI： 10.1177/154405910808700511

歯周組織の状態と血漿の酸化ストレス度・抗酸化力との関係

Effects of ethanol consumption on periodontal inflammation in rats

K. Irie, T. Tomofuji, N. Tamaki, T. Sanbe, D. Ekuni, T. Azuma, T. Maruyama, T. Yamamoto

JOURNAL OF DENTAL RESEARCH 87 ( 5 ) 456 - 460 2008.5

Language：English Publisher：INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R

DOI： 10.1177/154405910808700511

丸山貴之, 玉木直文, 友藤孝明, 江國大輔, 山中玲子, 竹内倫子, 山本龍生

日本歯周病学会会誌 50 ( 春季特別 ) 137 - 137 2008.4

Mechanical stimulation of gingiva reduces plasma 8-OHdG level in rat periodontitis International journal

Daisuke Ekuni, Takaaki Tomofuji, Naofumi Tamaki, Toshihiro Sanbe, Tetsuji Azuma, Reiko Yamanaka, Tatsuo Yamamoto, Tatsuo Watanabe

ARCHIVES OF ORAL BIOLOGY 53 ( 4 ) 324 - 329 2008.4

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Objective: Gingival cells respond to periodontal pathogens by generating reactive oxygen species, and such a condition would increase circulating oxidative stress. Improvement of gingival inflammation by toothbrushing may offer clinical benefits on not only periodontal health but also the circulatory conditions. We examined the effects of mechanical stimulation on the plasma 8-hydroxydeoxyguanosine level in a rat periodontitis model.
Design: In this experiment, male Wistar rats (n = 18) were divided into three groups. The control group received topical application of pyrogen-free water to the gingival sulcus for 8 weeks, while the other two groups received topical application of bacterial pathogens (lipopolysaccharide and proteases). After 4 weeks, half of the rats in the experimental groups received daily mechanical stimulation with an electric toothbrush for 4 weeks.
Results: Rats treated with bacterial pathogens presented periodontal tissue damage and increased plasma levels of 8-hydroxydeoxyguanosine. Mechanical stimulation by toothbrushing decreased gingival inflammation and oxidative DNA damage indicated by a decrease in plasma 8-hydroxydeoxyguanosine.
Conclusions: Mechanical stimulation of periodontally involved gingiva reduced 8-hydroxydeoxyguanosine in plasma and may contribute to a reduction in circulating oxidative stress associated molecules. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.archoralbio.2007.10.005

Mechanical stimulation of gingiva reduces plasma 8-OHdG level in rat periodontitis International journal

Daisuke Ekuni, Takaaki Tomofuji, Naofumi Tamaki, Toshihiro Sanbe, Tetsuji Azuma, Reiko Yamanaka, Tatsuo Yamamoto, Tatsuo Watanabe

ARCHIVES OF ORAL BIOLOGY 53 ( 4 ) 324 - 329 2008.4

Language：English Publisher：PERGAMON-ELSEVIER SCIENCE LTD

DOI： 10.1016/j.archoralbio.2007.10.005

岡山大学医学部・歯学部附属病院の頭頚部癌チーム医療における予防歯科の関わり

山中玲子, 水川展吉, 山本龍生, 小山玲子, 古田美智子, 江國大輔, 西川悟郎, 岡崎恵子, 志茂加代子, 羽川操, 森田学

岡山歯学会雑誌 27 ( 2 ) 93 - 98 2008

岡山大学医学部・歯学部附属病院の頭頚部癌チーム医療における予防歯科の関わり

山中玲子, 水川展吉, 山本龍生, 小山玲子, 古田美智子, 江國大輔, 西川悟郎, 岡崎恵子, 志茂加代子, 羽川操, 森田学

岡山歯学会雑誌 27 ( 2 ) 93 - 98 2008

Oral administration of vitamin c prevents alveolar bone resorption induced by high dietary cholesterol in rats International journal

Toshihiro Sanbe, Takaaki Tomofuji, Daisuke Ekuni, Tetsuji Azuma, Naofumi Tamaki, Tatsuo Yamamoto

JOURNAL OF PERIODONTOLOGY 78 ( 11 ) 2165 - 2170 2007.11

Language：English Publisher：AMER ACAD PERIODONTOLOGY

Background: A high-cholesterol diet stimulates alveolar bone resorption, which may be induced via tissue oxidative damage. Vitamin C reduces tissue oxidative damage by neutralizing free radicals and scavenging hydroxyl radicals, and its antioxidant effect may offer the clinical benefit of preventing alveolar bone resorption in cases of hyperlipidernia. We examined whether vitamin C could suppress alveolar bone resorption in rats fed a high-cholesterol diet.
Methods: In this 12-week study, rats were divided into four groups: a control group (fed a regular diet) and three experimental groups (fed a high-cholesterol diet supplemented with 0, 1, or 2 g/l vitamin C). Vitamin C was provided by adding it to the drinking water. The bone mineral density of the alveolar bone was analyzed by microcomputerized tomography. As an index of tissue oxidative damage, the 8-hydroxydeoxyguanosine level in the periodontal tissue was determined using a competitive enzyme-linked immunosorbent assay.
Results: Hyperlipidemia, induced by a high-cholesterol diet, decreased rat alveolar bone density and increased the number of tartrate-resistant acid phosphatase-positive osteoclasts. The expression of 8-hydroxydeoxyguanosine was upregulated in the periodontal tissues. Intake of vitamin C reduced the effect of a high-cholesterol diet on alveolar bone density and osteoclast differentiation and decreased periodontal 8-hydroxydeoxyguanosine expression.
Conclusion: In the rat model, vitamin C suppressed alveolar bone resorption, induced by high dietary cholesterol, by decreasing the oxidative damage of periodontal tissue.

DOI： 10.1902/jop.2007.070181

Oral administration of vitamin c prevents alveolar bone resorption induced by high dietary cholesterol in rats International journal

Toshihiro Sanbe, Takaaki Tomofuji, Daisuke Ekuni, Tetsuji Azuma, Naofumi Tamaki, Tatsuo Yamamoto

JOURNAL OF PERIODONTOLOGY 78 ( 11 ) 2165 - 2170 2007.11

Language：English Publisher：AMER ACAD PERIODONTOLOGY

DOI： 10.1902/jop.2007.070181

Chronic administration of lipopolysaccharide and proteases induces periodontal inflammation and hepatic steatosis in rats International journal

Takaaki Tomofuji, Daisuke Ekuni, Reiko Yamanaka, Hiroki Kusano, Tetsuji Azuma, Toshihiro Sanbe, Naofumi Tamaki, Tatsuo Yamamoto, Tatsuo Watanabe, Mutsumi Miyauchi, Takashi Takata

JOURNAL OF PERIODONTOLOGY 78 ( 10 ) 1999 - 2006 2007.10

Language：English Publisher：AMER ACAD PERIODONTOLOGY

Background: Epidemiologic studies suggest a relationship between periodontitis and liver diseases. A rat periodontitis model was used to investigate whether a causal relationship exists between periodontitis and liver diseases.
Methods: Fourteen male Wistar rats (8 weeks old) were divided into two groups: a periodontitis group in which Escherichia coli lipopolysaccharide (LPS) and Streptomyces griseus proteases were applied into the gingival sulcus for 8 weeks, and a control group using pyrogen-free water instead. After blood samples were collected, periodontal tissues and liver specimens were analyzed.
Results: Chronic administration of LPS and proteases to the gingival sulcus induced periodontitis and liver injury, including steatosis with inflammation and sinusoidal fibrosis. Apoptosis, enhanced concentration of 8-hydroxydeoxyguanosine, and activated production of tumor necrosis factor-alpha in liver were observed in the periodontitis group, with increased gingival inflammation, serum LPS, and reactive oxygen species.
Conclusion: Periodontal inflammation in a rat model induced fatty liver disease through increased serum LPS.

DOI： 10.1902/jop.2007.070056