Faculty Profiles - MARUYAMA Takayuki

Effects of improvement in periodontal inflammation by toothbrushing on serum lipopolysaccharide concentration and liver injury in rats. Reviewed International journal

Takaaki Tomofuji, Daisuke Ekuni, Toshihiro Sanbe, Tetsuji Azuma, Naofumi Tamaki, Koichiro Irie, Takayuki Maruyama, Tatsuo Yamamoto, Tatsuo Watanabe, Mutsumi Miyauchi, Takashi Takata

Acta odontologica Scandinavica 67 ( 4 ) 200 - 5 2009.7

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

Objective. Periodontitis increases the serum lipopolysaccharide level, contributing to liver injury. Toothbrushing improves periodontitis and may also affect serum lipopolysaccharide concentration and periodontitis-induced liver injury. The purpose of the present study was to examine whether the improvement in periodontal inflammation by toothbrushing clinically affects the serum lipopolysaccharide level and hepatic pathological changes in rat periodontitis. Material and methods. Thirty male Wistar rats were divided into 5 groups, 2 groups receiving topical application of pyrogen-free water to the gingival sulcus for 4 or 8 weeks. The next 2 groups received topical application of lipopolysaccharide and proteases for 4 or 8 weeks. The last group received topical application of lipopolysaccharide and proteases for 8 weeks, and the palatal gingiva was brushed with a powered toothbrush once a day for 4 weeks prior to the end of the experimental period. Results. Topical application of lipopolysaccharide and proteases induced not only periodontal inflammation but also an elevation in the serum lipopolysaccharide concentration, with increasing hepatic inflammation, steatosis and 8-hydroxydeoxyguanosine levels in a time-dependent mariner. The rats that received gingival stimulation showed decreased polymorphonuclear leukocyte infiltration and collagen loss levels in the periodontal lesions. Furthermore, this group also showed a decrease in serum lipopolysaccharide concentration and hepatic inflammation, steatosis and 8-hydroxydeoxyguanosine levels, compared with the group receiving no treatment. Conclusions. Toothbrushing promoted healing of periodontal lesions, decreased serum lipopolysaccharide concentration and suppressed liver injury in a rat periodontitis model.

DOI： 10.1080/00016350902794818

Vitamin C intake attenuates the degree of experimental atherosclerosis induced by periodontitis in the rat by decreasing oxidative stress. Reviewed International journal

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

Archives of oral biology 54 ( 5 ) 495 - 502 2009.5

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Objective: Periodontitis has been causally linked to cardiovascular disease, which is mediated through the oxidative stress induced by periodontitis. Since vitamin C has been suggested to limit oxidative damage, we hypothesized that vitamin C intake may reduce endothelial oxidative stress induced by periodontitis in the aorta. The aim of this study was to investigate the effects of vitamin C intake on the initiation of atherosclerosis in a ligature-induced rat periodontitis model.
Design: Eighteen 8-week-old-male Wistar rats were divided into three groups of six rats and all rats received daily fresh water and powdered food through out the 6-week study. In the vitamin C and periodontitis groups, periodontitis was ligature-induced for the first 4 weeks. In the vitamin C group, rats were given distilled water containing 1 g/L vitamin C for the 2 weeks after removing the ligature.
Results: In the periodontitis group, there was lipid deposition in the descending aorta and significant increases of serum level of hexanoyl-lysine (HEL), and aortic levels of nitrotyrosine expression, HEL expression and 8-hydroxydeoxyguanosine (8-OHdG) compared to the control group. Vitamin C intake significantly increased plasma vitamin C level and GSH:GSSG ratio (178% and 123%, respectively), and decreased level of serum HEL and aortic levels of nitrotyrosine, HEL and 8-OHdG (23%, 87%, 84%, and 38%, respectively).
Conclusions: These results suggest that vitamin C intake attenuates the degree of experimental atherosclerosis induced by periodontitis in the rat by decreasing oxidative stress. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.archoralbio.2009.02.006

Validity of a questionnaire for periodontitis screening of Japanese employees. Reviewed International journal

Tatsuo Yamamoto, Reiko Koyama, Naofumi Tamaki, Takayuki Maruyama, Takaaki Tomofuji, Daisuke Ekuni, Reiko Yamanaka, Tetsuji Azuma, Manabu Morita

Journal of occupational health 51 ( 2 ) 137 - 43 2009.3

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC OCCUPATIONAL HEALTH

Validity of a Questionnaire for Periodontitis Screening of Japanese Employees: Tatsuo YAMAMOTO, et al. Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences-Objectives: Workplaces are suitable for screening for periodontal disease effectively. However, the majority of workplaces do not have a screening program. One possible reason may be that pocket probing, which is commonly used for the screening, needs qualified examiners and is time-consuming. In this study, the validity of a self-reported questionnaire was assessed for screening of periodontitis in 50- to 59-yr-old male employees in Japan. Methods: A total of 250 people were asked to complete a self-administered questionnaire regarding signs and symptoms of periodontal disease, and experience of periodontal treatment, followed by a clinical examination by a dentist. Subjects with at least one tooth having a clinical attachment loss of 7 mm or more were defined as periodontitis patients. Results: Thirteen percent of the subjects were diagnosed as having periodontitis. Logistic regression selected 4 questions, "Are you a current or past smoker?", "Have your gums bled recently?", "Do you think that you can see more roots of teeth than in the past?", and "Have you ever been told that you need periodontal or gum treatment?" as potential predictors of periodontitis. When subjects with at least 3 "yes" responses to the 4 questions were separated from the others, the subjects with periodontitis were separated most effectively (showing the highest sensitivity + specificity: 1.524) from those without. The area under the receiver operating characteristic curve was 0.81. Conclusions: These results suggest that the self-reported questions are useful for screening of periodontitis in 50- to 59-yr-old Japanese workers.

DOI： 10.1539/joh.l8108

Effects of vitamin C intake on gingival oxidative stress in rat periodontitis. Reviewed International journal

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

Free radical biology & medicine 46 ( 2 ) 163 - 8 2009.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE INC

Increased levels of oxidative stress due to excessive production of reactive oxygen species are involved in the pathogenesis of periodontitis. Studies Suggest a negative association between plasma vitamin C level and the severity of periodontitis. We hypothesized that increases in plasma vitamin C levels after vitamin C intake might clinically reduce gingival oxidative stress in a rat periodontitis model. A ligature was placed around rat mandibular molars for 4 weeks to induce periodontitis, and the rats were then given drinking water with or without 1 g/L vitamin C for 2 weeks after the ligature was removed. The periodontitis-induced rats showed a 149% increase in 8-hydroxydeoxyguanosine level and a 40% decrease in reduced:oxidized glutathione ratio in gingival tissue. Vitamin C intake induced a 175% increase in plasma vitamin C level, resulting in an improvement in the gingival 8-hydroxydeoxyguanosine level (decreased) and in the reduced:oxidized glutathione ratio (increased). Furthermore, in ligature-induced periodontitis lesions, gene expression encoding inflammation, including interleukin-1 alpha and interleukin-1 beta, was more than twofold down-regulated by vitamin C intake. The results suggest that systemic administration of vitamin C could be clinically beneficial in improving periodontitis-induced oxidative stress by down-regulating inflammatory gene expression. (C) 2008 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.freeradbiomed.2008.09.040

Oxidative damage of rat liver induced by ligature-induced periodontitis and chronic ethanol consumption. Reviewed International journal

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

Archives of oral biology 53 ( 12 ) 1113 - 8 2008.12

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Objective: oxidative stress plays a central role in the initiation and progression of liver disease. Chronic ethanol consumption induces oxidative damage of the liver. Using a rat model, we previously showed that chronic administration of lipopolysaccharide and proteases to gingival sulcus induced both periodontal inflammation and liver injury. Periodontitis and ethanol consumption may have an additional effect on hepatic oxidative damage. The present study investigated the effects of periodontitis on ethanol-induced oxidative damage of the liver using a rat model.
Design: Male Wistar rats were divided into four groups (six rats/group). During the experimental period of eight weeks, two groups were fed an ethanol-containing liquid diet, and two groups were on a pair-fed control diet. Four weeks prior to the end of the experimental period, one group from each dietary treatment was ligated to induce periodontitis, while the other group was left unligated. In order to evaluate hepatic oxidative damage, the level of hexanoyl-lysine and the ratio of reduced form glutathione/oxidized form glutathione (GSH/GSSG) was determined. The concentration of blood hexanoyl-lysine was also measured as an index of circulating lipid peroxide.
Results: Ligature-induced periodontitis increased plasma levels of hexanoyl-lysine. in the liver, periodontitis decreased the CSH/GSSG ratio, and the combination of periodontitis and ethanol consumption induced a significant increase in hexanoyl-lysine level compared to ethanol consumption alone.
Conclusion: In the rat model, ligature-induced periodontitis increased plasma lipid peroxide, decreased the hepatic GSH/GSSG ratio and augmented ethanol-induced lipid peroxidation in the liver. (C) 2008 Elsevier Ltd. All rights reserved.

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. Reviewed International journal

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

Journal of periodontology 79 ( 11 ) 2136 - 42 2008.11

Language：English Publishing type：Research paper (scientific journal) 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