Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Yoshihisa Yamashita Last modified date:2018.06.22

Professor / Division of Oral Health, Growth and Development / Department of Dental Science / Faculty of Dental Science

1. Akihiko Tanaka, Kenji Takeuchi, Michiko Furuta, Toru Takeshita, Shino Suma, Takashi Shinagawa, Yoshihiro Shimazaki, Yoshihisa Yamashita, Relationship of toothbrushing to metabolic syndrome in middle-aged adults, Journal of Clinical Periodontology, 10.1111/jcpe.12876, 45, 5, 538-547, 2018.05, Aim: To examine the effect of toothbrushing on the development of metabolic syndrome (MetS), including assessment of periodontal status, in middle-aged adults. Methods: This 5-year follow-up retrospective study was performed in 3,722 participants (2,897 males and 825 females) aged 35–64 years who underwent both medical check-ups and dental examinations. Metabolic components included obesity, elevated triglycerides, blood pressure, fasting glucose and reduced high-density lipoprotein. Toothbrushing frequency was assessed using a questionnaire. Periodontal disease was defined as having at least one site with a pocket depth of ≥4 mm. Logistic regression analysis was performed to evaluate the relationship between toothbrushing frequency at the baseline examination and the development of MetS (≥3 components). Results: During follow-up, 11.1% of participants developed MetS. After adjusting for potential confounders including periodontal disease, participants with more frequent daily toothbrushing tended to have significantly lower odds of developing MetS (p for trend =.01). The risk of development of MetS was significantly lower in participants brushing teeth ≥3 times/day than in those brushing teeth ≤1 time/day (odds ratio = 0.64, 95% confidence interval = 0.45–0.92). Conclusions: Frequent daily toothbrushing was associated with lower risk of development of MetS..
2. Kenji Takeuchi, Michiko Furuta, Y. Okabe, Shino Suma, Toru Takeshita, S. Akifusa, M. Adachi, T. Kinoshita, T. Kikutani, Yoshihisa Yamashita, Swallowing disorders and 1-year functional decline in community-dwelling older adults receiving home care, Journal of Oral Rehabilitation, 10.1111/joor.12577, 44, 12, 982-987, 2017.12, The purpose of this study was to clarify the effect of swallowing disorders on functional decline in community-dwelling older adults receiving home care. This was a 1-year follow-up survey of 176 individuals ≥60 years living at home and receiving homecare services, without total dependence in basic daily living activities, in two mid-sized municipalities in Fukuoka, Japan. Functional decline was measured using the Barthel index (BI), and the primary outcome was total dependence in basic daily living activities (BI ≤ 20 points). Swallowing function was assessed using cervical auscultation, and the primary predictor was swallowing disorders. Logistic regression models were used to assess univariate and multivariate associations between baseline swallowing function and functional decline during follow-up. During follow-up 16 (9.1%), the participants became totally dependent in basic daily living activities. The participants with swallowing disorders had 6.41 times higher odds of total dependence in basic daily living activities compared to participants with normal swallowing function. After adjusting for potential confounders, swallowing disorders were significantly associated with higher odds of total dependence in basic daily living activities (odds ratio = 5.21, 95% confidence interval = 1.33-20.44). Regarding swallowing disorders, the corresponding population attributable fraction (%) of the incidence of total dependence in basic daily living activities was 50.4%. The current findings demonstrated that swallowing disorders were associated with greater risk of functional decline in basic daily living activities among older adults living at home and receiving home nursing care. Maintenance and improvement of swallowing function may prevent late-life functional decline..
3. Haruna Yasunaga, Toru Takeshita, Yukie Shibata, Michiko Furuta, Yoshihiro Shimazaki, Sumio Akifusa, Toshiharu Ninomiya, Yutaka Kiyohara, Ichiro Takahashi, Yoshihisa Yamashita, Exploration of bacterial species associated with the salivary microbiome of individuals with a low susceptibility to dental caries, Clinical Oral Investigations, 10.1007/s00784-016-2035-5, 21, 8, 2399-2406, 2017.11, Objective: Dental caries is caused by acidogenic plaque microbiota formed on saliva-bathed tooth surfaces, in which multiple organisms act collectively to initiate and expand a cavity. We explored bacterial species associated with the salivary microbiome of individuals with low susceptibility to dental caries. Materials and methods: The bacterial composition of saliva from 19 young adults was analyzed using barcoded pyrosequencing of the 16S rRNA gene; we compared 10 caries-experienced (CE) and nine caries-free (CF) individuals. A quantitative PCR assay of saliva from 139 orally healthy adults aged 40–59 years was carried out to confirm the result obtained by pyrosequencing analysis. Results: The microbiomes of CF individuals showed more diverse communities with a significantly greater proportion of the genus Porphyromonas. Among operational taxonomic units (OTUs) corresponding to the genus Porphyromonas, the OTU corresponding to P. pasteri was the most predominant and its relative abundance in CF individuals was significantly greater than in CE individuals (P < 0.001, Wilcoxon rank sum test). A quantitative PCR assay of saliva confirmed that the amounts of P. pasteri were significantly higher in individuals with lower caries experience (filled teeth <15, n = 67) than in those with higher caries experience (filled teeth ≥15, n = 72) (P < 0.001, Student’s t test). Conclusion: These results revealed an association between a greater abundance of P. pasteri and lower susceptibility to dental caries. Clinical relevance: P. pasteri may be a bacterial species that could potentially be used as a marker for maintaining a healthy oral microbiome against dental caries..
4. M. N. Zakaria, Michiko Furuta, Toru Takeshita, Yukie Shibata, R. Sundari, N. Eshima, Toshiharu Ninomiya, Yoshihisa Yamashita, Oral mycobiome in community-dwelling elderly and its relation to oral and general health conditions, Oral Diseases, 10.1111/odi.12682, 23, 7, 973-982, 2017.10, Objective: Oral fungal infection is generally associated with dysbiosis related to antibiotic use, immunodeficiency, or frailty. However, fungal colonization in a typical population without apparent symptoms and its associated conditions are poorly understood. In this study, oral fungal colonization in community-dwelling and independently living elderly populations was evaluated and factors affecting fungal colonization were analyzed. Subjects and Methods: The subjects (410; 181 males and 229 females) were 75–99 years of age; those under prior antibiotic use were excluded. Fungal populations in the saliva were evaluated by PCR-based molecular techniques. Body mass index (BMI), smoking habits, and oral health conditions were examined. Results: Salivary fungal amounts exceeded 104 CFU/ml in 63 (15.4%) of 410 subjects. Candida albicans was most frequently detected (98.4%), followed by Candida glabrata (54.0%), and Candida dubliniensis (38.1%) in those subjects with fungi at 104 CFU/ml or over. Fungi at 104 CFU/ml or over in the presence of C. glabrata or C. dubliniensis was significantly associated with low BMI. Conclusions: Candida albicans, C. glabrata, and C. dubliniensis dominated the oral mycobiome in Japanese community-dwelling elderly. Lower BMI might signify compromised health status and thus could result in susceptibility to specific candidiasis by C. glabrata and C. dubliniensis..
5. Kenji Takeuchi, Tomoyuki Ohara, Michiko Furuta, Toru Takeshita, Yukie Shibata, Jun Hata, Daigo Yoshida, Yoshihisa Yamashita, Toshiharu Ninomiya, Tooth loss and risk of dementia in the community: the Hisayama study
, American Geriatrics Society, 10.1111/jgs.14791, 65, 5, e95-e100, 2017.05.
6. Kenji Takeuchi, May Izumi, Michiko Furuta, Toru Takeshita, Yukie Shibata, Shinya Kageyama, Seijun Ganaha, Yoshihisa Yamashita, Association between posterior teeth occlusion and functional dependence among older adults in nursing homes in Japan, Geriatr Gerontol Int., 10.1038/srep22164, 17, 4, 622-627, 2017.04.
7. Shinya Kageyama, Toru Takeshita, Mikari Asakawa, Yukie Shibata, Kenji Takeuchi, Wataru Yamanaka, Yoshihisa Yamashita, Relative abundance of total subgingival plaque-specific bacteria in salivary microbiota reflects the overall periodontal condition in patients with periodontitis
, PLoS One, 10.1371/journal.pone.0174782, 12, 4, e0174782, 2017.04.
8. Yoshihiro Shimazaki, Bohan Fu, Koji Yonemoto, Michiko Furuta, Sumio Akifusa, Yukie Shibata, Toru Takeshita, Toshiharu Ninomiya, Yutaka Kiyohara, Yoshihisa Yamashita, Stimulated salivary flow rate and oral health status, J Oral Sci, 10.2334/josnusd.16-0372, 59, 1, 55-62, 2017.03.
9. Y. Okabe, Kenji Takeuchi, M. Izumi, Michiko Furuta, Toru Takeshita, Yukie Shibata, S. Kageyama, S. Ganaha, Yoshihisa Yamashita, Posterior teeth occlusion and dysphagia risk in older nursing home residents
a cross-sectional observational study, Journal of Oral Rehabilitation, 10.1111/joor.12472, 44, 2, 89-95, 2017.02, The total number of natural teeth was related to swallowing function among older adults; however, limited information is available regarding the impact of occluding pairs of teeth on swallowing function. This study aimed to examine the association between posterior teeth occlusion and dysphagia risk in older nursing home residents. This cross-sectional study included 238 residents aged ≥60 years from eight nursing homes in Aso City, Japan. Swallowing function was evaluated using the modified water swallowing test (MWST); the primary outcome was dysphagia risk (MWST score ≤3). Posterior teeth occlusion was assessed using number of functional tooth units (FTUs), determined based on number and location of the remaining natural and artificial teeth on implant-supported, fixed or removable prostheses. Univariate and multivariate logistic regression analyses were performed to examine the association between posterior teeth occlusion and dysphagia risk, adjusted for the covariates of number of natural teeth, demographic characteristics, comorbidities, physical function, body mass index and cognitive function. Of the 238 subjects, 44 (18·5%) were determined to be at risk of dysphagia based on the MWST scores. The odds ratio (OR) of dysphagia risk decreased in subjects with higher total FTUs [OR = 0·92, 95% confidence interval (CI) 0·87–0·98]. After adjusting for covariates, this association remained significant (OR = 0·90, 95% CI 0·84–0·97). Loss of posterior teeth occlusion was independently associated with dysphagia risk in older nursing home residents. Maintaining and restoring posterior teeth occlusion may be an effective measure to prevent dysphagia..
10. M. Izumi, Kenji Takeuchi, S. Ganaha, S. Akifusa, Yoshihisa Yamashita, Effects of oral care with tongue cleaning on coughing ability in geriatric care facilities
a randomised controlled trial, Journal of Oral Rehabilitation, 10.1111/joor.12451, 43, 12, 953-959, 2016.12, Methods for preventing aspiration pneumonia are needed soon in order to reduce mortality from aspiration pneumonia and promote the health of the elderly. The aim of this randomised controlled trial was to examine whether oral care with tongue cleaning improves coughing ability in elderly individuals living in geriatric care facilities. Participants comprised of 114 residents of 11 group homes and private nursing homes in Aso City in Kumamoto Prefecture. Participants were randomly assigned to either (i) a group that underwent routine oral care with tongue cleaning (intervention group; n�=�58) or (ii) a group that underwent routine oral care alone (control group; n�=�56). Coughing ability was evaluated by measuring peak expiratory flow (PEF) before and after 4�weeks of intervention. Before the intervention, PEF did not differ significantly between the intervention group (1�65���1�11�L�s−1) and control group (1�59���1�05�L�s−1; P�=�0�658). However, on termination of the intervention, PEF was significantly higher in the intervention group (2�54���1�42�L�s−1) than in the control group (1�90���1�20�L�s−1; P�=�0�014). After the intervention, PEF had increased significantly in both groups; however, this increase was significantly greater in the intervention group (0�90���0�95�L�s−1) than in the control group (0�31���0�99�L�s−1; P�<�0�001). Oral care with tongue cleaning led to increased PEF, suggesting improved coughing ability. Oral care incorporating tongue cleaning appears to be important for preventing aspiration pneumonia..
11. Yukie Shibata, Yoshihisa Yamashita, Kanji Tsuru, Kazuhiko Ishihara, Kyoko Fukazawa, Kunio Ishikawa, Preventive effects of a phospholipid polymer coating on PMMA on biofilm formation by oral streptococci, Applied Surface Science, 10.1016/j.apsusc.2016.08.108, 390, 602-607, 2016.12, The regulation of biofilm formation on dental materials such as denture bases is key to oral health. Recently, a biocompatible phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) coating, was reported to inhibit sucrose-dependent biofilm formation by Streptococcus mutans, a cariogenic bacterium, on the surface of poly(methyl methacrylate) (PMMA) denture bases. However, S. mutans is a minor component of the oral microbiome and does not play an important role in biofilm formation in the absence of sucrose. Other, more predominant oral streptococci must play an indispensable role in sucrose-independent biofilm formation. In the present study, the effect of PMB coating on PMMA was evaluated using various oral streptococci that are known to be initial colonizers during biofilm formation on tooth surfaces. PMB coating on PMMA drastically reduced sucrose-dependent tight biofilm formation by two cariogenic bacteria (S. mutans and Streptococcus sobrinus), among seven tested oral streptococci, as described previously [N. Takahashi, F. Iwasa, Y. Inoue, H. Morisaki, K. Ishihara, K. Baba, J. Prosthet. Dent. 112 (2014) 194–203]. Streptococci other than S. mutans and S. sobrinus did not exhibit tight biofilm formation even in the presence of sucrose. On the other hand, all seven species of oral streptococci exhibited distinctly reduced glucose-dependent soft biofilm retention on PMB-coated PMMA. We conclude that PMB coating on PMMA surfaces inhibits biofilm attachment by initial colonizer oral streptococci, even in the absence of sucrose, indicating that PMB coating may help maintain clean conditions on PMMA surfaces in the oral cavity..
12. Xiaochen Men, Yukie Shibata, Toru Takeshita, Yoshihisa Yamashita, Identification of anion channels responsible for fluoride resistance in oral streptococci, PLoS One, 10.1371/journal.pone.0165900, 11, 11, e0165900, 2016.11.
13. Y. Okabe, Michiko Furuta, S. Akifusa, Kenji Takeuchi, M. Adachi, T. Kinoshita, T. Kikutani, Seiji Nakamura, Yoshihisa Yamashita, Swallowing function and nutritional status in Japanese elderly people receiving home-care services
A 1-year longitudinal study, Journal of Nutrition, Health and Aging, 10.1007/s12603-015-0645-2, 20, 7, 697-704, 2016.07, Objectives: Malnutrition is a serious health concern for frail elderly people. Poor oral function leading to insufficient food intake can contribute to the development of malnutrition. In the present study, we explored the longitudinal association of malnutrition with oral function, including oral health status and swallowing function, in elderly people receiving home nursing care. Design: Prospective observational cohort study with 1-year follow-up. Setting: Two mid-sized cities in Fukuoka, Japan from November 2010 to March 2012. Participants: One hundred and ninety-seven individuals, aged ≥ 60 years, living at home and receiving homecare services because of physical disabilities, without malnutrition. Measurements: Oral health status, swallowing function, taking modified-texture diets such as minced or pureed foods, nutritional status, cognitive function, and activities of daily living were assessed at baseline. The associations between malnutrition at 1-year follow-up and these related factors were analyzed using a logistic regression model. Results: Swallowing disorders [risk ratio (RR): 5.21, 95% confidence interval (95% CI): 1.65–16.43] were associated with malnutrition. On the other hand, oral health status did not have a direct association with malnutrition. Conclusion: Swallowing disorders may be associated with the incidence of malnutrition in elderly people receiving home-care. The findings indicate that maintaining swallowing function may contribute to the prevention of malnutrition in frail elderly people..
14. Michiko Furuta, An Liu, Takashi Shinagawa, Kenji Takeuchi, Toru Takeshita, Yoshihiro Shimazaki, Yoshihisa Yamashita, Tooth loss and metabolic syndrome in middle-aged Japanese adults, Journal of Clinical Periodontology, 10.1111/jcpe.12523, 43, 6, 482-491, 2016.06.
15. Yum Imabayashi, Masafumi Moriyama, Toru Takeshita, IShinsuke Ieda, Hayashida Jun-Nosuke, Akihiko Tanaka, Takashi Maehara, Sachiko Furukawa, Miho Ohta, Keigo Kubota, Maski Yamaguchi, Noriko Ishiguro, Yoshihisa Yamashita, Seiji Nakamura, Molecular analysis of fungal populations in patients with oral candidiasis using next-generation sequencing, SCIENTIFIC REPORTS, 10.1038/srep28110, 6, 28110, 2016.06.
16. Toru Takeshita, Shinya Kageyama, Michiko Furuta, Hidenori Tsuboi, Kenji Takeuchi, Yukie Shibata, Yoshihiro Shimazaki, Sumio Akifusa, Toshiharu Ninomiya, Yutaka Kiyohara, Yoshihisa Yamashita, Bacterial diversity in saliva and oral health-related conditions: the Hisayama study, SCIENTIFIC REPORTS, 10.1038/srep22164, 6, 22164, 2016.02.
17. Aisyah Ahmad, Michiko Furuta, Takashi Shinagawa, Kenji Takeuchi, Yoshihiro Shimazaki, Yoshihisa Yamashita, Association of periodontal status with liver abnormalities and metabolic syndrome
, Journal of Oral Science, 10.2334/josnusd.57.335, 57, 4, 335-343, 2015.12.
18. Genkai Sae, Kikutani Takeshi, Suzuki Ryo, Tamura Fumiyo, Yamashita Yoshihisa, Yoshida Mitsuyoshi, Loss of occlusal support affects the decline in activities of daily living in elderly people receiving home care
, J Prosthodont Res, 10.1016/j.jpor.2015.06.003, 59, 4, 243-248, 2015.10.
19. Kenji Takeuchi, Mai Izumi, Michiko Furuta, Toru Takeshita, Yukie Shibata, Shinya Kageyama, Yoshihisa Yamashita, Posterior teeth ccclusion associated with cognitive function in nursing home older residents: a cross-sectional observational study
, PLoS One, 10.1371/journal.pone.0141737, 10, 10, e0141737, 2015.10.
20. Keisuke Moritani, Toru Takeshita, Yukie Shibata, Toshiharu Ninomiya, Yutaka Kiyohara, Yoshihisa Yamashita, Acetaldehyde production by major oral microbes, Oral Diseases, 10.1111/odi.12341, 21, 6, 748-754, 2015.09.
21. Mitsuo Sakamoto, Dan Li, Yukie Shibata, Toru Takeshita, Yoshihisa Yamashita, Moriya Ohkuma, Porphyromonas pasteri sp. nov., isolated from human saliva
, Int J Syst Evol Microbial, 10.1099/ijs.0.000294, 65, 8, 2511-2515, 2015.08.
22. Ryo Suzuki, Takeshi Kikutani, Mitsuyoshi Yoshida, Yoshihisa Yamashita, Yoji Hirayama, Prognosis-related factors concerning oral and general conditions for homebound older adults in Japan, Geriatrics and Gerontology International, 10.1111/ggi.12382, 15, 8, 1001-1006, 2015.08, Purpose: The present study examined the relationship between oral function, such as eating/swallowing, and life prognosis among a homebound elderly population, considering physical and mental function. Methods: The participants were 511 homebound older adults aged 65 years or older living in four Japanese prefectures. Sex, age, activities of daily living (ADL), cognitive function, underlying disease, nutritional status as Mini-Nutritional Assessment-Short Form (MNA®-SF), swallowing function, dietary modification and occlusal status were examined at baseline. Participants were categorized into poor outcome (died or admitted to hospital or nursing home) and good outcome (still under home care) groups at 1-year follow up, and significant related baseline factors were analyzed. In addition, these groups were compared by the ADL subgroup divided into <60 (lower) and ≥60 (higher) by Barthel Index. Results: In total, 473 participants were followed up (poor outcome group 177 [37.4%], good outcome group 296 [62.6%]). Sex, age, ADL, MNA®-SF, swallowing function, dietary modification and occlusal support were significantly different between these groups. Logistic regression analysis showed that sex and MNA®-SF score were significantly related to prognosis in the lower ADL group, and sex, age, Charlson Comorbidity Index and occlusal support were significantly related in the higher ADL group. Conclusions: ADL was strongly correlated with life prognosis in homebound older adults. Within the higher ADL participants, occlusal support was related to this outcome..
23. Kenji Takeuchi, Michiko Furuta, Toru Takeshita, Yukie Shibata, Yoshihiro Shimazaki, Akifusa Sumiro, Toshiharu Ninomiya, Yutaka Kiyohara, Yoshihisa Yamashita, Serum antibody to Porphyromonas gingivitis and periodontitis progression: the Hisayama Study
, J Clin Periodontology, 10.1111/jcpe.12431, 2015.07.
24. Takeuchi, Kenji; Furuta, Michiko; Takeshita, Toru; Shibata, Yukie; Shimazaki, Yoshihiro; Akifusa, Sumio; Ninomiya, Toshiharu; Kiyohara, Yutaka; Yamashita, Yoshihisa, Risk Factors for Reduced Salivary Flow Rate in a Japanese Population: The Hisayama Study, BIOMED RESEARCH INTERNATIONAL, 10.1155/2015/381821, 381821, 2015.02.
25. Takeshita, Toru; Yasui, Masaki; Shibata, Yukie; Furuta, Michiko; Saeki, Yoji; Eshima, Nobuoki; Yamashita, Yoshihisa, Dental plaque development on a hydroxyapatite disk in young adults observed by using a barcoded pyrosequencing approach, SCIENTIFIC REPORTS, 10.1038/srep08136, 5, 2015.01.
26. Hashiba, Takafumi; Takeuchi, Kenji; Shimazaki, Yoshihiro; Takeshita, Toru; Yamashita, Yoshihisa, Chewing Xylitol Gum Improves Self-Rated and Objective Indicators of Oral Health Status under Conditions Interrupting Regular Oral Hygiene, TOHOKU JOURNAL OF EXPERIMENTAL MEDICINE, 10.1620/tjem.235.39, 235, 1, 39-46, 2015.01.
27. Furuta, Michiko; Shimazaki, Yoshihiro; Tanaka, Shunichi; Takeuchi, Kenji; Shibata, Yukie; Takeshita, Toru; Nishimura, Fusanori; Yamashita, Yoshihisa, Gender-Specific Associations of Serum Antibody to Porphyromonas gingivalis and Inflammatory Markers, BIOMED RESEARCH INTERNATIONAL, 10.1155/2015/897971, 2015, 897971, 2015.01.
28. Aisyah Ahmad, Michiko Furuta, Takashi Shinagawa, Kenji Takeuchi, Toru Takeshita, Yoshihiro Shimazaki, Yoshihisa Yamashita, Association of periodontal status with liver abnormalities and metabolic syndrome, Journal of oral science, 10.2334/josnusd.57.335, 57, 4, 335-343, 2015.01, Although an association between periodontal status and liver abnormalities has been reported, it has not been described in relation to metabolic syndrome (MetS), which often coexists with non-alcoholic fatty liver disease. We examined the association of a combination of liver abnormality and MetS with periodontal condition in Japanese adults, based on the level of alcohol consumption. In 2008, 4,207 males aged 45.4 ± 8.9 years and 1,270 females aged 45.9 ± 9.7 years had annual workplace health check-ups at a company in Japan. Periodontal status was represented as periodontal pocket depth at the mesio-buccal and mid-buccal sites for all teeth. Alanine aminotransferase (ALT), and metabolic components were examined. Multiple linear regression analysis showed a significant association between deep pocket depth and the coexistence of elevated ALT and MetS in males with low alcohol consumption. Females showed no such relationship. In conclusion, the association between periodontal condition and the combination of elevated ALT and MetS was confirmed in males. That is, a clear association between liver abnormalities and periodontal condition was seen in male subjects with no or low alcohol consumption and MetS, providing new insights into the connection between liver function and periodontal health..
29. M. N. Zakaria, Toru Takeshita, Yukie Shibata, Hidefumi Maeda, Naohisa Wada, A. Akamine, Yoshihisa Yamashita, Microbial community in persistent apical periodontitis
A 16S rRNA gene clone library analysis, International Endodontic Journal, 10.1111/iej.12361, 48, 8, 717-728, 2015.01, Aim: To characterize the microbial composition of persistent periapical lesions of root filled teeth using a molecular genetics approach. Methodology: Apical lesion samples were collected from 12 patients (23-80 years old) who visited the Kyushu University Hospital for apicectomy with persistent periapical lesions associated with root filled teeth. DNA was directly extracted from each sample and the microbial composition was comprehensively analysed using clone library analysis of the 16S rRNA gene. Enterococcus faecalis, Candida albicans and specific fimA genotypes of Porphyromonas gingivalis were confirmed using polymerase chain reaction (PCR) analysis with specific primers. Results: Bacteria were detected in all samples, and the dominant findings were P. gingivalis (19.9%), Fusobacterium nucleatum (11.2%) and Propionibacterium acnes (9%). Bacterial diversity was greater in symptomatic lesions than in asymptomatic ones. In addition, the following bacteria or bacterial combinations were characteristic to symptomatic lesions: Prevotella spp., Treponema spp., Peptostreptococcaceae sp. HOT-113, Olsenella uli, Slackia exigua, Selemonas infelix, P. gingivalis with type IV fimA, and a combination of P. gingivalis, F. nucleatum, and Peptostreptococcaceae sp. HOT-113 and predominance of Streptococcus spp. On the other hand, neither Enterococcus faecalis nor C. albicans were detected in any of the samples. Conclusion: Whilst a diverse bacterial species were observed in the persistent apical lesions, some characteristic patterns of bacterial community were found in the symptomatic lesions. The diverse variation of community indicates that bacterial combinations as a community may cause persistent inflammation in periapical tissues rather than specific bacterial species..
30. Takeshita, Toru; Matsuo, Kazuki; Furuta, Michiko; Shibata, Yukie; Fukami, Kaoru; Shimazaki, Yoshihiro; Akifusa, Sumio; Han, Dong-Hung; Kim, Hyun-Duck; Yokoyama, Takeshi; Ninomiya, Toshiharu; Kiyohara, Yutaka; Yamashita, Yoshihisa, Distinct composition of the oral indigenous microbiota in South Korean and Japanese adults, SCIENTIFIC REPORTS, 10.1038/srep06990, 4, 2014.11.
31. Obata, Junko; Takeshita, Toru; Shibata, Yukie; Yamanaka, Wataru; Unemori, Masako; Akamine, Akifumi; Yamashita, Yoshihisa, Identification of the Microbiota in Carious Dentin Lesions Using 165 rRNA Gene Sequencing, PLOS ONE, 10.1371/journal.pone.0103712, 9, 8, 2014.08.
32. Ieda, Shinsuke; Moriyama, Masafumi; Takashita, Toru; Maehara, Takashi; Imabayashi, Yumi; Shinozaki, Shoichi; Tanaka, Akihiko; Hayashida, Jun-Nosuke; Furukawa, Sachiko; Ohta, Miho; Yamashita, Yoshihisa; Nakamura, Seiji, Molecular Analysis of Fungal Populations in Patients with Oral Candidiasis Using Internal Transcribed Spacer Region, PLOS ONE, 10.1371/journal.pone.0101156, 9, 6, 2014.06.
33. Kenji Takeuchi, Aida Jun, Ito Kanade, Michiko Furuta, Yamashita Yoshihisa, Osaka Ken, Nutritional status and dysphagia risk among community-deweeling frail older adults, Journal of Nutrition and Health Aging, 10.1007/s12603-014-0025-3, 18, 4, 352-357, 2014.04.
34. Naoki Kakudate, Tsukasa Muramatsu, Mami Endoh, Kazuhito Satomura, Takeyoshi Koseki, Yuji Sato, Kayoko Ito, Tadashi Ogasawara, Seiji Nakamura, Etsuo Kishimoto, Haruhiko Kashiwazaki, Yoshihisa Yamashita, Kimio Uchiyama, Tatsuji Nishihara, Yutaka Kiyohara, Yasuaki Kakinoki, Factors associated with dry mouth in dependent Japanese elderly, Gerodontology, 10.1111/j.1741-2358.2012.00685.x, 31, 1, 11-18, 2014.03, Objectives To identify factors associated with dry mouth. Background Dry mouth adversely affects oropharyngeal health, particularly in elderly, and can lead to pneumonia. A better understanding of the epidemiology of dry mouth is therefore important in improving treatment strategies and oral health in high-risk elderly patients. Methods We conducted a cross-sectional study involving 383 dependent Japanese elderly individuals (65-84 [n = 167] and ≥85 [n = 216] years) at eight long-term care facilities and hospitals. Thirty-four potential factors associated with dry mouth were examined by multiple logistic regression analysis. The primary outcome was dry mouth, as diagnosed by tongue dorsum moisture. Results We identified that body mass index and severity of physical disability were identified as a potential factors associated with dry mouth in the super-elderly (≥85 years) group, whereas severity of physical disability, outcome measurement time, high daily water consumption, mouth breathing, use of antidepressants and diuretics, and high frequency of daily brushing (≥2 times per day; Odds ratio: 5.56; 95% Confidence Interval: 1.52-20.00) were associated with dry mouth in the 65- to 84-year-old group. Conclusion To our knowledge, this is the first study to identify a link between frequency of daily brushing and dry mouth and suggests that tooth brushing should be encouraged in high-risk dependent Japanese elderly (65-84 years), particularly those taking antidepressants and/or diuretics..
35. Nakano Yoshio, Toru Takeshita, Kamio Noriaki, Susumu Shiota, Yukie Shibata, Suzuku Nao, Yoneda Masahiro, Hirofuji Takao, Yamashita Yoshihisa, Supervised machine learning-based classification of oral malodor based on the microbiota in saliva samples, ARTIFICIAL INTELLIGENCE IN MEDICINE, 10.1016/j.artmed.2013.12.001, 60, 2, 97-101, 2014.02.
36. Li Dan, Yukie Shibata, Toru Takeshita, Yamashita Yoshihisa, A Novel Gene Involved in the Survival of Streptococcus mutans under Stress Conditions, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 10.1128/AEM.02549-13, 80, 1, 97-103, 2014.01.
37. Koichi Yamane, Yasunori Ayukawa, Toru Takeshita, Akihiro Furuhashi, Yoshihisa Yamashita, Kiyoshi Koyano, Bacterial adhesion affinities of various implant abutment materials, Clinical Oral Implants Research, 10.1111/j.1600-0501.2012.02574.x, 24, 12, 1310-1315, 2013.12, Objectives: To investigate bacterial adhesion to various abutment materials. Material and methods: Thirty volunteers participated in this study. Resin splints were fabricated, and five types of disks were fabricated from pure titanium, gold-platinum alloy, zirconia, alumina, and hydroxyapatite with uniform surface roughness and attached to the buccal surface of each splint. After 4 days of use by the subjects, the plaque accumulated on the disk surfaces was analyzed. The bacterial community structure was evaluated using 16S rRNA gene profiling with terminal restriction fragment length polymorphism analysis. The total bacterial count on each disk was estimated using quantitative polymerase chain reaction. Results: Terminal restriction fragment length polymorphism profiles were more similar between tested materials than between subjects, suggesting that the bacterial community structures on the abutment material were influenced more by the individuals than by the type of material. However, the total number of bacteria attached to a disk was significantly different among five materials (P < 0.001, Brunner-Langer test for longitudinal data). Fewer bacteria were attached to the gold-platinum alloy than to the other materials. Conclusions: Gold-platinum alloy appears to be useful material for abutments when considering the accumulation of plaque. However, alternative properties of the abutment material, such as effects on soft tissue healing, should also be taken into consideration when choosing an abutment material..
38. Kawada-Matsuo, Miki, Oogai, Yuichi, Zendo, Takeshi, Nagao, Junichi;, Yukie Shibata, Yamashita Yoshihisa, Ogura, Yoshitoshi, Hayashi, Tetsuya, Sonomoto, Kenji, Komatsuzawa, Hitoshi, Involvement of the Novel Two-Component NsrRS and LcrRS Systems in Distinct Resistance Pathways against Nisin A and Nukacin ISK-1 in Streptococcus mutans, APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 10.1128/AEM.00780-13, 79, 15, 4751-4755, 2013.08.
39. Fujinaka Hidetake, Toru Takeshita, Sato Hirayuki, Yamamoto Tetsuji, Nakamura Junji, Hase Tadashi, Yamashita Yoshihisa, Relationship of periodontal clinical parameters with bacterial composition in human dental plaque, Archives of Microbiology, 10.1007/s00203-013-0883-9, 195, 6, 371-383, 2013.06.
40. Michiko Furuta, Manae Komiya-Nonaka, Sumio Akifusa, Yoshihiro Shimazaki, Munehisa Adachi, Toshinori Kinoshita, Takeshi Kikutani, Yoshihisa Yamashita, Interrelationship of oral health status, swallowing function, nutritional status, and cognitive ability with activities of daily living in Japanese elderly people receiving home care services due to physical disabilities, Community Dentistry and Oral Epidemiology, 10.1111/cdoe.12000, 41, 2, 173-181, 2013.04, Objectives: Malnutrition and cognitive impairment lead to declines in activities of daily living (ADL). Nutritional status and cognitive ability have been shown to correlate with oral health status and swallowing function. However, the complex relationship among the factors that affect decline in ADL is not understood. We examined direct and indirect relationships among oral health status, swallowing function, nutritional status, cognitive ability, and ADL in Japanese elderly people living at home and receiving home care services because of physical disabilities. Methods: Participants were 286 subjects aged 60 years and older (mean age, 84.5 ± 7.9 years) living at home and receiving home care services. Oral health status (the number of teeth and wearing dentures) was assessed, and swallowing function was examined using cervical auscultation. Additionally, ADL, cognitive ability, and nutritional status were assessed using the Barthel Index, the Clinical Dementia Rating Scale, and the Mini Nutritional Assessment-Short Form, respectively. Path analysis was used to test pathways from these factors to ADL. Results: The mean number of teeth present in the participants was 8.6 ± 9.9 (edentates, 40.6%). Dysphagia, malnutrition, and severe cognitive impairment were found in 31.1%, 14.0%, and 21.3% of the participants, respectively. Path analysis indicated that poor oral health status and cognitive impairment had a direct effect on denture wearing, and the consequent dysphagia, in addition to cognitive impairment, was positively associated with malnutrition. Malnutrition as well as dysphagia and cognitive impairment directly limited ADL. Conclusions: A lower number of teeth are positively related to swallowing dysfunction, whereas denture wearing contributes to recovery of swallowing function. Dysphagia, cognitive impairment, and malnutrition directly and indirectly decreased ADL in elderly people living at home and receiving home nursing care. The findings suggest that preventing tooth loss and encouraging denture wearing when teeth are lost may indirectly contribute to maintaining or improving ADL, mediated by recovery of swallowing function and nutritional status..
41. Shimazaki Yoshihiro, Kushiyama Misato, Murakamai Masatoshi, Yamashita Yoshihisa, Relationship between normal serum creatinine concentration and periodontal disease in Japanese middle-aged males, J Periodontol, 10.1902/jop.2012.110528., 84, 1, 94-99, 2013.01, BACKGROUND:
Periodontitis has been shown to be closely related to diabetes, which was recently found to be associated with lower serum creatinine. Conversely, several studies have suggested a positive relationship between periodontitis and abnormally high concentrations of serum creatinine associated with renal dysfunction, seemingly contradicting the above. This study evaluates periodontal status and serum levels of creatinine within the normal range to resolve this apparent contradiction.
A comprehensive health examination of 907 Japanese males, 49 to 59 years old, was performed from 2000 to 2002. A blood sample was collected from the antecubital vein after an overnight fast. The periodontal parameters were periodontal probing depth (PD) and clinical attachment loss (AL). We examined the association between serum creatinine concentration within the normal range and periodontal parameters.
Serum creatinine concentration within the normal range was inversely correlated with mean PD and mean AL. In multivariate linear regression analyses, every 0.1-mg/dL increment in serum creatinine concentration was associated with a 0.064-mm decrease in both mean PD and mean AL (P <0.05) after adjusting for confounding variables.
This study finds a significant inverse association between normal serum creatinine concentration and periodontal disease.
42. Kikutani Takeshi, Yoshida Mitsuyoshi, Enoki Hiromi, Yamashita Yoshihisa, Akifusa Sumio, Shimazaki Yoshihiro, Hirano Hirohiko, Tamura Fumio, Relationship between nutrition status and dental occlusion in community-dwelling frail elderly people, Geriatr Gerontol Int, 10.1111/j.1447-0594.2012.00855.x., 13, 1, 50-54, 2013.01, AIM:
This study aimed to determine the risk of malnutrition in some communities where the frail elderly receive public long-term care insurance. We also clarified the dental problems in those at risk of malnutrition.
A total of 716 frail elderly who lived in eight cities in Japan (240 males and 476 females with a mean age of 83.2±8.6 years) were divided into three groups according to Mini Nutritional Assessment short form results: well nourished, at risk of malnutrition and malnourished. They were also divided into three groups in terms of remaining teeth occlusion and denture occlusion: group A, natural dentition with adequate function; group B, partially or fully edentulous, but maintaining functional occlusion with dentures in either or both jaws; and group C, functionally inadequate occlusion with no dentures. The relationship between nutrition status and dental occlusion was evaluated using logistic regression analysis with sex, age, activities of daily living and cognitive function as covariates.
The number of participants in each of the groups was as follows: 251 well nourished, 370 at risk of malnutrition and 95 malnourished. When they were divided into just two groups, (i) well nourished and (ii) at risk of malnutrition plus malnourished, in order to study malnutrition risk factors, there were significant relationships between their nutritious status and sex, Barthel index, and occlusion.
This large-scale cross-sectional survey showed that loss of natural teeth occlusion was a risk factor for malnutrition among community-dwelling frail elderly..
43. Kawato Takayuki, Tanaka Hideki, Tabuchi Masaki, Ooshima Kana, Nakai Kumiko, Yamashita Yoshihisa, Maeno Masao, Continual gram-negative bacterial challenge accelerates stroke onset in stroke-prone spontaneously hypertensive rats, Clin Exp Hypertens, 10.3109/10641963.2012.689042., 35, 1, 28-34, 2013.01, This study examined the effects of continual Gram-negative bacterial challenge on stroke onset. Stroke onset occurred significantly earlier in stroke-prone spontaneously hypertensive rats (SHRSP) injected with a bacterial cell suspension of Gram-negative rods or lipopolysaccharides (LPSs) than in uninjected controls. Paralysis of the hindlimb, piloerection, hypokinesis, and hyperkinesis were observed in LPS-injected SHRSP but not in uninjected controls during stroke onset. The serum levels of NOx, thiobarbituric acid reactive substance, and 8-hydroxydeoxyguanosine increased in LPS-injected SHRSP. These results suggest that continual Gram-negative bacterial challenge induces accelerated stroke onset in SHRSP, probably caused by oxidative stress responses derived from LPSs..
44. Fukui Nao, 嶋﨑 義浩, 品川 隆, 山下 喜久, Periodontal status and metabolic syndrome in middle-aged Japanese, J Periodontol, 10.1902/jop.2012.110605, 83, 11, 1363-1371, 2012.11, BACKGROUND:
Metabolic syndrome (MetS) increases the risk of various lifestyle-related diseases. Although some studies have reported a significant relationship between periodontal status and MetS, little information exists about the nature of the relationship between periodontal health status and MetS.
Comprehensive health examinations of 6,421 Japanese individuals (aged 34 to 77 years) were performed. Five components (obesity, high blood pressure, low high-density lipoprotein cholesterol, hypertriglyceridemia, and high plasma glucose) of MetS were evaluated, and individuals with ≥3 positive components were defined as having MetS. The periodontal parameters were periodontal probing depth (PD) and clinical attachment level (CAL), and each parameter was divided into three categories (none/mild: ≤3 mm; moderate: 4 to 5 mm; and severe: ≥6 mm).
When PD and CAL were analyzed separately in multivariate models, both parameters were significantly associated with MetS. In a multivariate logistic regression analysis using a combination of PD and CAL as an independent variable, individuals with severe PD and severe CAL or with moderate PD and moderate CAL had significantly higher odds ratios for MetS, but severe CAL without severe PD was not significantly associated with MetS.
The results of this study suggest that periodontal status, particularly in individuals suspected to have untreated periodontal infection indicated by ≥4 mm PD, is significantly associated with MetS.
45. H. Li, Toru Takeshita, Michiko Furuta, M. Tomioka, Yukie Shibata, Y. Shimazaki, K. Makimura, Yoshihisa Yamashita, Molecular characterization of fungal populations on the tongue dorsum of institutionalized elderly adults, Oral Diseases, 10.1111/j.1601-0825.2012.01944.x, 18, 8, 771-777, 2012.11, Objectives: To characterize the global composition of oral fungal populations in frail elderly adults and to investigate the relationship with their health status. Materials and methods: We investigated the fungal populations on the tongue dorsum in 291 institutionalized elderly adults by molecular PCR-based techniques using internal transcribed spacer regions of nuclear ribosomal DNA. Results: Quantitative PCR analysis showed that fungi were present on the tongue dorsum of 128 subjects at ≥104CFU per sample, and 35 of them exceeded 105CFU per sample. Length heterogeneity-PCR analysis and nucleotide sequence determinations showed that Candida albicans was most frequently detected in those subjects with fungi at ≥104CFU per sample (105 subjects), followed by Candida dubliniensis (78), Malassezia restricta (57), and Candida tropicalis (45). Statistical analysis revealed that those subjects with ≥105CFU of fungi other than C. albicans per sample had an increased risk of fever (≥7 febrile days per 12months) compared with subjects with <105CFU per sample, after adjustment for other fever-associated confounding factors. Conclusions: These data demonstrate that the oral cavity of the elderly is inhabited by a diverse array of fungi not limited to typical Candida species and they suggest that the diversity in distribution is associated with health status..
46. Yamanaka Wataru, Takeshita Toru, Shibata Yukie, Eshima Nobuoki, Yokoyama Takeshi, Yamashita Yoshihisa, Compositional stability of a salivary bacterial population against supragingival microbiota shift following periodontal therapy, PLoS One, 10.1371/journal.pone.0042806., 7, 8, e42806, 2012.08, Supragingival plaque is permanently in contact with saliva. However, the extent to which the microbiota contributes to the salivary bacterial population remains unclear. We compared the compositional shift in the salivary bacterial population with that in supragingival plaque following periodontal therapy. Samples were collected from 19 patients with periodontitis before and after periodontal therapy (mean sample collection interval, 25.8 ± 2.6 months), and their bacterial composition was investigated using barcoded pyrosequencing analysis of the 16S rRNA gene. Phylogenetic community analysis using the UniFrac distance metric revealed that the overall bacterial community composition of saliva is distinct from that of supragingival plaque, both pre- and post-therapy. Temporal variation following therapy in the salivary bacterial population was significantly smaller than in the plaque microbiota, and the post-therapy saliva sample was significantly more similar to that pre-therapy from the same individual than to those from other subjects. Following periodontal therapy, microbial richness and biodiversity were significantly decreased in the plaque microbiota, but not in the salivary bacterial population. The operational taxonomic units whose relative abundances changed significantly after therapy were not common to the two microbiotae. These results reveal the compositional stability of salivary bacterial populations against shifts in the supragingival microbiota, suggesting that the effect of the supragingival plaque microbiota on salivary bacterial population composition is limited..
47. Takeshita T, Suzuki N, Nakano Y, Yasui M, Yoneda M, Shimazaki Y, Hirofuji T, Yamashita Y, Discrimination of the oral microbiota associated with high hydrogen sulfide and methyl mercaptan production, Sci Rep, 2, 215, Open Access Journal, 2012.04.
48. Suzuki N, Tanabe K, Takeshita T, Yoneda M, Iwamoto T, Oshiro S, Yamashita Y, Hirofuji T, Effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds, J Breath Res, 10.1088, 6, 017106, 2012.03.
49. Oshikohji T, Shimazaki Y, Shinagawa T, Fukui N, Akifusa S, Hirata Y, Yamashita Y, Relationship between receiving a workplace oral health examination including oral health instruction and oral health status in the Japanese adult population, J Occup Health, 53, 3, 222-229, 2011.12.
50. Takeshita T, Yasui M, Tomioka M, Nakano Y, Shimazaki Y, Yamashita Y, Enteral tube feeding alters the oral indigenous microbiota in elderly adults, Appl Environ Microbiol, 77, 19, 6739-6745, 2011.10.
51. Uchimaru M, Sakai T, Moroi R, Shiota S, Shibata Y, Deguchi M, Sakai H, Yamashita Y, Terada Y, Antimicrobial and antifungal effects of tissue conditioners containing a photocatalyst, Dent Mater J, 30, 5, 691-699, 2011.10.
52. Seki M, Karakama F, Kawato T, Tanaka H, Saeki Y, Yamashita Y, Effect of xylitol gum on the level of oral mutans streptococci of preschoolers: block-randomised trial, Int Dent J, 10.1111, 61, 5, 274-280, 2011.10.
53. Masayuki Uchimaru, Takako Sakai, Ryoji Moroi, Susumu Shiota, Yukie Shibata, Mikito Deguchi, Hidetaka Sakai, Yoshihisa Yamashita, Yoshihiro Terada, Antimicrobial and antifungal effects of tissue conditioners containing a photocatalyst, Dental Materials Journal, 10.4012/dmj.2010-203, 30, 5, 691-699, 2011.10, This study examined the antimicrobial/antifungal ability of a tissue conditioner containing a photocatalyst for Escherichia coli, Streptococcus mutans, Staphylococcus aureus and Candida albicans. The photocatalyst was mixed with tissue conditioners powders at concentrations of 0, 10, 15, and 20 wt%. Tissue conditioners powders containing a photocatalyst were mixed with liquid to make test specimens. Test specimens inoculated by each microorganism were irradiated by ultraviolet light for 0-, 2-and 4 hours. The antimicrobial/antifungal effects were evaluated by the CFU technique. The CFU values of each microorganism for tissue conditioners containing a photocatalyst showed significant decrease following UV-irradiation. The improvement in antimicrobial/antifungal effects was concomitant with the increase of the mixing ratio and the irradiation time. Therefore, the results indicated that tissue conditioners containing a photocatalyst might have photocatalytic ability..
54. Fujimoto A, Akifusa S, Hirofuji T, Yamashita Y, Involvement of suppressor of cytokine signaling-1 in globular adiponectin-induced granulocyte colony-stimulating factor in RAW 264 cell, Mol Immunol, 48, 15-16, 2052-2058, 2011.09.
55. Kitagawa N, Shiota S, Shibata Y, Takeshita T, Yamashita Y, Characterization of MbrC involved in bacitracin resistance in Streptococcus mutans, FEMS Microbiol Lett, 381, 1, 61-67, 2011.05.
56. Shibata Y, Kawada-Matsuo M, Shirai Y, Saito N, Li D, Yamashita Y, Streptococcus mutans diacylglycerol kinase homologue: a potential target for anti-caries chemotherapy, J Med Microbiol, 60, Pt5, 625-630, 2011.05.
57. Shimazaki Y, Akifusa S, Takeshita T, Shibata Y, Doi Y, Hata J, Ninomiya T, Hirakawa Y, Kiyohara Y, Yamashita Y, Effectiveness of the salivary occult blood test as a screening method for periodontal status, J Periodontol, 82, 4, 581-587, 2011.04.
58. Kamio N, Akifusa S, Yamashita Y., Diacylglycerol kinase alpha regulates globular adiponectin-induced reactive oxygen species, Free Radic Res., 45, 3, 336-341, 2011.03.
59. Takeshita T, Tomioka M, Shimazaki Y, Matsuyama M, Koyano K, Yamashita Y, Microfloral characterization of tongue coating and associated risk for pneumonia-related health problems in institutionalized older adults, J Am Geriatr Soc, 58, 6, 1050-1057, 2010.01.
60. Takeshita T, Suzuki N, Nakano Y, Shimazaki Y, Yoneda M, Hirofuji T, Yamashita Y, Relationship between oral malodor and the global composition of indigenous bacterial populations in saliva, Appl Environ Microbiol, 76, 9, 2806-2814, 2010.05.
61. Yamaguchi N, Hamachi T, Kamio N, Akifusa S, Masuda K, Nakamura Y, Nonaka K, Maeda K, Hanazawa S, Yamashita Y, Expression levels of adiponectin receptors and periodontitis., J Periodontal Res, 45, 2, 296-300, 2010.04.
62. Kushiyama M, Shimazaki Y, Yamashita Y, Relationship between metabolic syndrome and periodontal disease in Japanese adults, J Periodontol, 80巻、1610-1615, 2009.10.
63. Shimazaki y, Kim JB, Han D-H, Ryu JI, Park DY, Yamashita Y, Comparison of oral health status in adult populations of Japan and South Korea, J Dent Health, 59, 5, 596-602, 2009.10.
64. Kamio N, Akifusa S, Yamaguchi N, Nonaka K, Yamashita Y , Anti- inflammatory activity of a globular adiponectin function on RAW 264 cells stimulated by lipopolysaccharide from Aggregatibacter actinomycetemcomitans, FEMS Immunol Med Microbiol, 56巻、241-247, 2009.08.
65. Shibata Y, Yamashita Y, van der Ploeg JR, The serotype-specific glucose side chain of rhamnose-glucose polysaccharides is essential for adsorption of bacteriophage M102 to Streptococcus mutans, FEMS Miclobiol Lett, 294巻、68-73, 2009.05.
66. Shimazaki Y, Tomioka M, Saito T, Nabeshima F, Ikematsu H, Koyano K, Yamashita Y: , Influence of oral health on febrile status in long-term hospitalized elderly patients, Arch Gerontol Geriatr, 48巻、411-414, 2009.05.
67. Kawada-Matsuo M, Shibata Y, Yamashita Y, Role of two component signaling response regulators in acid tolerance of Streptococcus mutans, Oral Microbiol Immunol, 24巻、173-176, 2009.04.
68. Akifusa S, Kamio N, Shimazaki Y, Yamaguchi N, Yamashita Y, Involvement of Ca(2+) in globular adiponectin-induced reactive oxygen species, Biochem Biophys Res Commun, 381巻、649-653, 2009.04.
69. Kushiyama M, Shimazaki Y, Murakami M, Yamashita Y, Relationship between intake of green tea and periodontal disease, J Periodontol , 80巻、372-377, 2009.03.
70. Akifusa S, Kamio N, Shimazaki Y, Yamaguchi N, Nishihara T, Yamashita Y, Globular adiponectin-induced RAW 264 apoptosis is regulated by a reactive oxygen species-dependent pathway involving Bcl-2, Free Radic Med, 46巻、1308-1316, 2009.03.
71. Shibata Y, van der Ploeg JR, Kozuki T, Shirai Y, Saito N, Kawada-Matsuo M, Takeshita T, Yamashita Y, Kinase activity of the dgk gene product is involved in the virulence of Streptococcus mutans, Microbiology, 155巻、557-565ページ, 2009.02.
72. Takeshita T, Nakano Y, Kumagai T, Yasui M, Kamio N, Shibata Y, Shiota S, Yamashita Y, The ecological proportion of indigenous bacterial populations in saliva is correlated with oral health status, ISME J, 3巻、65-78ページ, 2009.01.
73. Nakano Y, Takeshita T, Kamio N, Shiota S, Shibata Y, Yasui M, Yamashita Y, Development and application of a T-RFLP data analysis method using correlation coefficient matrices, J Microbiol Methods , 75巻、501-505ページ, 2008.12.
74. Akifusa S, Kamio N, Shimazaki Y, Yamaguchi N, Yamashita Y, Regulation of globular adiponectin-induced apoptosis by reactive oxygen/nitrogen species in RAW264 macrophages, Free Radic Biol Med, 45巻、1326-1339ページ, 2008.11.
75. Kamio N, Akifusa S, Yamaguchi N, Yamashita Y, Induction of granulocyte colony-stimulating factor by globular adiponectin via the MEK-ERK pathway., Mol Cell Endocrinol , 292巻、20-25ページ, 2008.09.
76. Saito T, Oobayashi K, Shimazaki Y, Yamashita Y, Iwasa Y, Nabeshima F, Ikematsu H, Association of dry tongue to pyrexia in long-term hospitalized patients, Gerontology, 54巻、2号、87-91, 2008.05.
77. Saito T, Yamaguchi N, Shimazaki Y, Hayashida H, Yonemoto K, Doi Y, Kiyohara Y, Iida M, Yamashita Y, Serum levels of resistin and adiponectin in women with periodontitis: the Hisayama study, J Dent Res, 87巻4号319-322頁, 2008.04.
78. Kawato T, Yamashita Y, Katono T, Kimura A, Maeno M, Effects of antibodies against a fusion protein consisting of parts of cell surface protein antigen and glucosyltransferase of Streptococcus sobrinus on cell adhesion of mutans streptococci, Oral Microbiol Immunol, 23巻1号14-20頁, 2008.02.
79. Yamaguchi N, Kukita T, Li YJ, Kamio N, Fukumoto S, Nonaka K, Ninomiya Y, Hanazawa S, Yamashita Y, Adiponectin inhibits induction of TNF-alpha/RANKL-stimulated NFATc1 via the AMPK signaling, FEBS Lett, 582巻3号451-456頁, 2008.02.
80. Shimazaki Y, Shirota T, Uchida K, Koji Yonemoto, Yutaka Kiyohara, Mituo Iida, and Yoshihisa Yamashita, Intake of dairy products and periodontal disease: the Hisayama study., Journal of Periodontology, 79:131-137, 2008.01.
81. Takeshita T, Nakano Y, Yamashita Y., Improved accuracy in T-RFLP phylogenetic analysis using a novel internal size standard definition, Oral Microbial. Immunol., 22(6):419-28, 2007.12.
82. Shimazaki Y, Saito T, Yonemoto K, Kiyohara Y, Iida M, and Yamashita Y., Relationship of metabolic syndrome to periodontal disease in Japanese women: the hisayama study, J. Dent. Res., 86:271-275 , 2007.03.
83. Yamaguchi N, Kukita T, Li YJ, Martinez Argueta JG, Saito T, Hanazawa S, and Yamashita Y. , Adiponectin inhibits osteoclast formation stimulated by lipopolysaccharide from Actinobacillus actinomycetemcomitans, FEMS Immunol. Med. Microbiol. , 49:28-34, 2007.02.
84. Torigoe H, Seki M, Yamashita Y, Sugaya A, and Maeno M. , Detection of Haemophilus influenzae by loop-mediated isothermal amplification (LAMP) of the outer membrane protein P6 gene, Jpn. J. Infect. Dis. , 60:55-58 , 2007.02.
85. Nagata E, Okayama H, Ito HO, Yamashita Y, Inoue M, and Oho T. , Serotype-specific polysaccharide of Streptococcus mutans contributes to infectivity in endocarditis, Oral Microbiol. Immunol., 21:420-423 , 2006.12.
86. Shimazaki Y, Saito T, Kiyohara Y, Kato I, Kubo M, Iida M, and Yamashita Y., The influence of current and former smoking on gingival bleeding: the Hisayama study, J. Periodontol., 77:1430-1435, 2006.08.
87. Nakano Y, Takeshita T, and Yamashita Y., TRFMA: a web-based tool for terminal restriction fragment length polymorphism analysis based on molecular weight, Bioinformatics, 22:1788-1789, 2006.07.
88. Saito T, Murakami M, Shimazaki Y, Matsumoto S, and Yamashita Y., The Extent of Alveolar Bone Loss Is Associated With Impaired Glucose Tolerance in Japanese Men, J. Periodontol., 77:392-397, 2006.03.
89. Seki M, Yamashita Y, Shibata Y, Torigoe H, Tsuda H, and Maeno M., Effect of mixed mutans streptococci colonization on caries development, Oral Microbiol. Immunol., 21:47-52, 2006.02.
90. Nakano Y., Shibata Y., Kawada M., Kojima M., Fukamachi H., Shibata Y., Okano S., Matsushima K., Abiko Y., and Yamashita Y., A searchable database for proteomes of oral microorganisms, Oral Microbiol. Immunol., 10.1111/j.1399-302X.2005.00235.x, 20, 6, 344-348, 20:344-348, 2005.12.
91. Yamaguchi N., Argueta JG., Masuhiro Y., Kagishita M., Nonaka K, Saito T., Hanazawa S., and Yamashita Y., Adiponectin inhibits Toll-like receptor family-induced signaling, FEBS Lett., 10.1016/j.febslet.2005.11.019, 579, 30, 6821-6826, 579:6821-6826, 2005.12.
92. Shimazaki Y., Saito T., Kiyohara Y., Kato I., Kubo M., Iida M., and Yamashita Y., Relationship between Drinking and Periodontitis: The Hisayama Study, J. Periodontol., 10.1902/jop.2005.76.9.1534, 76, 9, 1534-1541, 76:1534-1541, 2005.09.
93. Suzuki N., Seki M., Nakano Y., Kiyoura Y., Maeno M., and Yamashita Y., Discrimination of Streptococcus pneumoniae from viridans group streptococci by genomic subtractive hybridization, J. Clin. Microbiol., 10.1128/JCM.43.9.4528-4534.2005, 43, 9, 4528-4534, 43:4528-4534, 2005.09.
94. Saito T., Shimazaki Y., Kiyohara Y., Kato I., Kubo M., Iida M., and Yamashita Y., Relationship between Obesity, Glucose Tolerance, and Periodontal Disease in Japanese Women, J. Periodont. Res., 10.1111/j.1600-0765.2005.00813.x, 40, 4, 346-353, 40:346-353, 2005.08.
95. Shibata Y., Kawada M., Nakano Y., Toyoshima K., and Yamashita Y., Identification and characterization of an autolysin-encoding gene of Streptococcus mutans, Infect. Immun., 10.1128/IAI.73.6.3512-3520.2005, 73, 6, 3512-3520, 73:3512-3520, 2005.06.
96. Fukamachi H., Nakano Y., Okano S., Shibata Y., Abiko Y., and Yamashita Y., High production of methyl mercaptan by L-methionine-α-deamino-γ-mercaptomethane lyase (METase) from Treponema denticola, Biochem. Biophys. Res. Commun.., 10.1016/j.bbrc.2005.03.139, 331, 1, 127-131, 331:127-131, 2005.05.
97. Seki M., and Yamashita Y., Decreasing caries prevalence in Japanese preschool children is accompanied with a reduction in mutans streptococci infection, Inter. Dental J., 55:100-104, 2005.04.
98. Seki M., Yamashita Y., Torigoe H., Tsuda H., Sato S., and Maeno M., Loop-Mediated Isothermal Amplification Method Targeting the lytA Gene for Detection of Streptococcus pneumoniae, J. Clin. Microbiol., 10.1128/JCM.43.4.1581-1586.2005, 43, 4, 1581-1586, 43:1581-1586, 2005.04.
99. Imatani T., Kato T., Okuda K., and Yamashita Y., Histatin 5 inhibits apoptosis in human gingival fibroblasts induced by Porphyromonas gingivalis cell-surface polysaccharide, Eur. J. Med. Res., 9:528-532, 2004.11.
100. Suzuki N., Nakano Y., Yoshida A., Yamashita Y., and Kiyoura Y., Real-timeTaqMan PCR for quantifying oral bacteria during biofilm formation, J. Clin. Microbiol., 10.1128/JCM.42.8.3827-3830.2004, 42, 8, 3827-3830, 42:3827-3830, 2004.08.
101. Yoshida A., Kawada M., Suzuki N., Nakano Y., Oho T., Saito T., and Yamashita Y., TaqMan real-time PCR Assay for the correlation of Treponema denticola numbers to the severity of periodontal disease, Oral Microbiol. Immunol., 10.1111/j.0902-0055.2004.00142.x, 19, 3, 196-200, 19:196-200, 2004.06.
102. Engels-Deutsch, M., Pini, A., Yamashita, Y., Shibata, Y., Haikel, Y., Scholler-Guinard, M., and Klein, J-P., Insertional inactivation of pac and rmlB genes reduces the release of tumor necrosis factor alpha, interleukin-6, and interleukin-8 induced by Streptococcus mutans in monocytic, dental pulp, and periodontal ligament cells, Infect. Immun., 10.1128/IAI.71.9.5169-5177.2003, 71, 9, 5169-5177, 71:5169-5177, 2003.09.
103. Shibata, Y., Ozaki, K., Seki, M., Kawato, T., Tanaka, H., Nakano, Y., and Yamashita, Y., Analysis of loci required for determination of serotype antigenicity in Streptococcus mutans and its clinical utilization, J. Clin. Microbiol., 10.1128/JCM.41.9.4107-4112.2003, 41, 9, 4107-4112, 41:4107-4112, 2003.09.
104. Tsuda, H., Yamashita, Y., Shibata, Y., Nakano, Y., and Koga, T., Gene involved in bacitracin resistance in Streptococcus mutans, Antimicrob. Agents Chemother., 46:3756-3764, 2002.12.
105. Shibata, Y., Yamashita, Y., Ozaki, K., Nakano, Y., and Koga, T., Expression and characterization of streptococcal rgp genes required for rhamnan synthesis in Escherichia coli, Infect. Immun., 10.1128/IAI.70.6.2891-2898.2002, 70, 6, 2891-2898, 70:2891-2898, 2002.06.
106. Suzuki, N., Nakano, Y., Yoshida, Y., Nezu, T., Terada, Y., Yamashita, Y., and Koga, T., Guanosine diphosphate-4-keto-6-deoxy-D-mannose reductase in the pathway for the synthesis of GDP-6-deoxy-D-talose in Actinobacillus actinomycetemcomitans, Eur. J. Biochem., 10.1046/j.1432-1033.2002.03331.x, 269, 23, 5963-5971, 269: 5963-5971, 2002.01.
107. Ozaki, K., Shibata, Y., Yamashita, Y., Nakano, Y., Tsuda, H., and Koga, T., A novel mechanism for glucose side-chain formation in rhamnose-glucose polysaccharide synthesis, FEBS Lett., 10.1016/S0014-5793(02)03661-X, 532, 1-2, 159-163, 532:159-163, 2002.01.
108. Yoshida, A., Nakano, Y., Yamashita, Y., Oho, T., Ito,H., Kondo, M., Ohishi, M., and Koga, T., Immunodomminant region of Actinobacillus actinomycetemcomitans 40-kilodalton heat shock protein in patients with rheumatoid arthritis, J. Dent. Res., 80, 1, 346-350, 80:346-350, 2001.01.
109. Shimazaki, Y., Soh, I., Saito, T., Yamashita, Y., Koga, T., Miyazaki, H.,and Takehara, T., Influence of dentition status on physical disability, mental impairment, and mortality in institutionalized elderly people, J. Dent. Res., 80, 1, 340-345, 80:340-345, 2001.01.
110. Oho, T., Yoshida, Y., Shimazaki, Y., Yamashita, Y., and Koga, T., Characteristics of patients complaining of halitosis and the usefulness of gas chromatography for diagnosing halitosis, Oral Surg. Oral Med. Oral Pathol. Oral Radiol Endod., 10.1067/moe.2001.112543, 91, 5, 531-534, 91:531-534, 2001.01.
111. Oho, T., Yoshida, Y., Shimazaki, Y., Yamashita, Y., and Koga, T., Psychological condition of patients complaining of halitosis, J. Dent., 10.1016/S0300-5712(00)00057-9, 29, 1, 31-33, 29:31-33, 2001.01.
112. Shimazaki, Y., Mitoma, M., Oho, T., Nakano. Y., Yamashita, Y., Okano, K., Nakano, Y., Fukuyama, M., Fujihara, N., Nada, Y., and Koga, T., Passive immunization with milk produced from an immunized cow prevents oral recolonization by Streptococcus mutans, Clin. Diagno. Labo. Immunol., 10.1128/CDLI.8.6.1136-1139.2001, 8, 6, 1136-1139, 8:1136-1139, 2001.01.
113. Yoshimura M., Nakano Y., Yamashita Y., Oho T., Saito T. and Koga T., Formatiom of Methyl Mercaptan from L-Methionine by Porphyromonas gingivalis, Infect. Immun., 10.1128/IAI.68.12.6912-6916.2000, 68, 12, 6912-6916, 68:6912-6916, 2000.12.
114. Nakano Y., Suzuki N., Yoshida Y., Nezu T., Yamashita Y. and Koga T., Thymidine diphosphate-6-deoxyl-L-lyxo-4-hexulose Reductase Synthesizing dTDP-6-deoxy-L-talose from Actinobacillus actinomycetemcomitans, J. Biol. Chem., 10.1074/jbc.275.10.6806, 275, 10, 6806-6812, 275:6806-6812, 2000.03.
115. Tsuda H., Yamashita Y., Toyoshima K., Yamaguchi N., Oho T., Nakano Y., Nagata K. and Koga T., Role of serotype-specific polysaccharide in the resistance of Streptococcus mutans to phagocytosis by human polymorphonuclear leukocytes, Infec. Immun., 10.1128/IAI.68.2.644-650.2000, 68, 2, 644-650, 68:644-650, 2000.02.
116. Nakano Y., Yoshida Y., Suzuki N, Yamashita Y. and Koga T., A gene cluster for the synthesis of serotype d-specific polysaccharide antigen in Actinobacillus actinomycetemcomitans, Biochim. Biophys. Acta, 10.1016/S0167-4781(00)00179-2, 1493, 1-2, 259-263, 1493:259-263, 2000.01.
117. Suzuki, N., Nakano Y., Yoshida, Y., Nakao, H., Yamashita, Y., and Koga, T., Genetic analysis of the gene cluster for the synthesis of serotype a-specific polysaccharide antigen in Actinobacillus actinomycetemcomitans, Biochim. Biophys. Acta, 10.1016/S0167-4781(00)00229-3, 1517, 1, 135-138, 1517:135-138, 2000.01.
118. Oho T., Yamashita Y., Shimazaki Y., Kushiyama M. and Koga T., Simple and rapid detection of Streptococcus mutans and Streptococcus sobrinus in human saliva by polymerase chain reaction, Oral Microbiol. Immunol., 15, 4, 258-262, 15:258-262, 2000.01.
119. Yamashita, Y., Shibata, Y., Nakano, Y., Tsuda, H., Kido, N., Ohta, M., and Koga, T., A nobel gene required for rhamnose-glucose polysaccharide synthesis in Streptococcus mutans, J. Bacteriol, 181, 20, 6556-6559, 181:6556-6559, 1999.10.
120. Yoshida, Y., Nakano, Y., Nezu, T., Yamashita, Y., and Koga, T., A novel NDP-6-deoxyhexosyl-4-ulose reductase in the pathway for the synthesis of dTDP-D-fucose, J. Biol. Chem., 10.1074/jbc.274.24.16933, 274, 24, 16933-16939, 274:16933-16939, 1999.06.
121. Yoshida, A., Nakano, Y., Yamashita, Y., Oho, T., Shibata, Y., Ohishi, M., and Koga, T., A novel dnaK operon from Porphyromonas gingivalis, FEBS Lett., 10.1016/S0014-5793(99)00237-9, 446, 2-3, 287-291, 446:287-291, 1999.01.
122. Yamashita, Y., Tomihisa, T., Nakano, Y., Shimazaki, Y., Oho, T., and Koga, T., Recombination between gtfB and gtfC is reqired for survival of a dTDP-rhamonose synthesis-deficient mutant of Streptococcus mutans in the presence of sucrose, Infect. Immun., 67, 7, 3693-3697, 67:3693-3697, 1999.01.
123. Saito, T., Shimazaki, Y., Yamashita, Y., Koga, T., Tsuzuki, M., and Sakamoto, M., Association between periodontitis and exercise capacity, Periodontal Insights, 6:9-12, 1999.01.
124. Oho, T., Shimazaki, Y., Mitoma, M., Yoshimura, M., Yamashita, Y., Okano, K., Nakano, Y., Kawagoe, H., Fukuyama, M., Fujihara, N., Koga, T., Bovine milk antibodies against cell surface protein antigen PAc- glucosyltransferase fusion protein suppress cell adhesion and alter glucan synthesis of Streptococcus mutans, J. Nutr., 129, 10, 1836-1841, 129:1836-41, 1999.01.
125. Yoshida, Y., Nakano, Y., Suzuki, N., Nakao, H., Yamashita, Y., and Koga, T., Genetic analysis of the gene cluster responsible for synthesis of serotype e-specific polysaccharide antigen in Actinobacillus actinomycetemcomitans, Biochim. Biophys. Acta, 10.1016/S0167-4781(99)00192-X, 1489, 2-3, 457-461, 1489:457-461, 1999.01.
126. Shibata, Y., Yamashita, Y., Nakano, Y., and Koga, T., Isolation and characterization of the rml gene homologs from Porphyromonas gingivalis, Oral Microbiol. Immunol., 10.1034/j.1399-302X.1999.140602.x, 14, 6, 339-347, 14:339-347, 1999.01.
127. Yamashita, Y., Tsukioka,Y., Tomihisa, T., Nakano, Y., and Koga, T., Genes involved in cell wall localization and side chain formation of rhamnose-glucose polysaccharide in Streptococcus mutans, J. Bacteriol., 180, 21, 5803-5807, 180:5803-5807, 1998.11.
128. Yamaguchi, N., Saito, T., Ikeda, D., Hideshima, A., Yamashita, Y., and Koga, T.:, Caries prevalence in junior high school students 2 year after ceasing a fluoride mouthrinsing program, J. Dent. Health, 48:146-148, 1998.01.
129. Yamashita, Y., Tsukioka, Y., Nakano, Y., Tomihisa, K., Oho, T., and Koga, T., Biological fuctions of UDP-glucose synthesis in Streptococcus mutans, Microbiology, 144, 1235-1245, 144:1235-1245, 1998.01.
130. Katoh, Y., Ansai, T., Takehara, T., Yamashita, Y., Miyazaki, H., Jenny, J., and Cons, N. C., A comparison of DAI scores and characteristics of occlusal traits in three ethnic groups of Asian origin, Int. Dent. J., 48:405-411, 1998.01.
131. Yamaguchi, N., Tsuda, H., Yamashita, Y., and Koga, T., Binding of the capsule-like serotype-specific polysaccharide antigen and the lipopolysaccharide from Actinobacillus actinomycetemcomitans to human compement-derived opsonins, Oral Microbiol. Immunol., 13, 6, 348-354, 13:348-354, 1998.01.
132. Yamashita, Y., Tsukioka,Y., Tomihisa, T., Nakano, Y., and Koga, T., A gene cluster for 6-deoxy-L-talan synthesis in Actinobacillus actinomycetemcomitans, Biochim. Biophys. Acta, 10.1016/S0167-4781(98)00174-2, 1442, 2-3, 409-414, 1442:409-414, 1998.01.
133. Yoshida, Y., Nakano, Y., Yamashita, Y., and Koga, T., Identification of a gene locus essential for serotype b-specific antigen synthesis in Actinobacillus actinomycetemcomitans, Infect. Immun., 66:107-114, 1998.01.
134. Oho, T., Yu, H., Yamahstia, Y., and Koga, T., Binding of salivary glycoprotein-secretory immunoglobulin A complex to the surface protein antigen of Streptococcus mutans, Infect. Immun., 66, 1, 115-121, 66:115-121, 1998.01.