Longitudinal association between periodontal condition and glycaemic status in middle-aged adults: A cross-lagged panel analysis.

AIM: To investigate the existence of a bidirectional temporal relationship between periodontal condition and glycaemic status. MATERIALS AND METHODS: This longitudinal study included 2198 participants with mean age 43.4 ± 7.7 years, who underwent dental examinations in Yokohama, Japan, at two time points, 2003-2004 and 2008-2009, at an interval of 5 years. Periodontal condition was assessed by the mean value of probing pocket depth (PPD) and clinical attachment level (CAL). Glycaemic status was assessed by fasting glucose and glycated haemoglobin (HbA1c). RESULTS: The cross-lagged panel models showed the effect of HbA1c at baseline on mean PPD at follow-up (ß = 0.044, p = .039). There was a marginal effect of fasting glucose on the mean PPD (ß = 0.037, p = .059). It was similar to the effect of fasting glucose or HbAlc on mean CAL. However, in the opposite direction, no effect of mean PPD or CAL at baseline on fasting glucose or HbAlc at follow-up was identified. CONCLUSIONS: This study demonstrated a unidirectional relationship between glycaemic status and periodontal condition. The study population, however, had mostly mild periodontitis. Future studies are needed to investigate the effect of periodontal condition on glycaemic status in patients with severe periodontitis.

Disrupted tongue microbiota and detection of nonindigenous bacteria on the day of allogeneic hematopoietic stem cell transplantation.

Disruption of the intestinal microbiota caused by intensive chemotherapy, irradiation and antibiotics can result in development of severe gut graft-versus-host disease and infectious complications, leading to poorer outcomes among allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Although the oral cavity is also densely colonized by indigenous microorganisms, the bacterial composition in allo-HSCT recipients remains unclear. We determined the tongue microbiota composition of 45 patients with hematological disorders on the day of transplantation and compared them to 164 community-dwelling adults. The V1-V2 regions of the 16S rRNA gene sequences demonstrated that the allo-HSCT recipients had less diverse and distinct microbiota from that of community-dwelling adults. The full-length 16S rRNA gene sequences identified 146 bacterial taxa in the microbiota of allo-HSCT recipients, of which 34 bacterial taxa did not correspond to bacteria primarily inhabiting the oral cavity deposited in the expanded Human Oral Microbiome Database. Notably, the detection of Staphylococcus haemolyticus and/or Ralstonia pickettii was significantly associated with a higher risk of mortality during the follow-up period. These results demonstrate that the oral cavity of allo-HSCT recipients is colonized by a disrupted microbiota on the day of transplantation and suggest that detection of specific nonindigenous taxa could be a predictor of transplant outcome.

Yogurt product intake and reduction of tooth loss risk in a Japanese community.

AIM: To evaluate the longitudinal association between yogurt product intake and oral health in a population-based study. MATERIALS AND METHODS: This study included 1967 Japanese residents aged 40-79 years who underwent dental examinations in 2012. Among them, 1469 participants were followed up in 2017 for the incidence of tooth loss, which was defined as two or more teeth lost over 5 years. The intake of yogurt products, defined as yogurt and lactic acid beverages, was estimated using a semi-quantitative food frequency questionnaire. The composition of the salivary microbiota was evaluated. RESULTS: The Poisson regression model showed that a higher intake of yogurt products was negatively associated with the incidence of tooth loss (p for trend = .020), adjusted for potential confounding factors. Mediation analysis confirmed that periodontal condition partly mediated the effect of yogurt product intake on tooth loss, while dental caries experience did not. Additionally, we confirmed the association of a high intake of yogurt products with a low percentage of the salivary microbiota pattern, which was associated with poor oral health. CONCLUSION: These findings suggest that the intake of yogurt products is associated with a lower risk of tooth loss resulting from periodontal disease, probably via modulation of the oral microbiome composition.

Association between periodontitis and fibrotic progression of non-alcoholic fatty liver among Japanese adults.

AIM: Non-alcoholic fatty liver (NAFL) is known to develop into liver fibrosis, which increases the risk of liver cirrhosis and liver cancer. The association between periodontal condition and fibrotic progression of NAFL is unclear. This study aimed to clarify this longitudinal association. MATERIALS AND METHODS: Among 4812 participants aged 35-64 years undergoing annual health check-ups between 2003 and 2004, and follow-up 5 years later, 392 participants were diagnosed with NAFL. After excluding participants with liver fibrosis at baseline, 341 participants were followed up for 5 years. NAFL disease fibrosis score of ≥-1.455 was used to evaluate the probability of the presence of liver fibrosis. RESULTS: During the follow-up period, 10.6% of participants progressed to liver fibrosis. A higher clinical attachment level (CAL) tended to be associated with the incidence of liver fibrosis in the logistic regression analysis (odds ratio [OR] 1.82, 95% confidence interval [CI], 0.94-3.49, p = .074). The stratified analysis by obesity revealed a significant association with higher CAL in obese participants (OR 2.87, 95% CI, 1.23-6.69, p = .015), but not in non-obese participants. CONCLUSION: Higher CAL was associated with an increased probability of liver fibrosis in obese adults with NAFL.

Longitudinal Associations of Toothbrushing With Obesity and Hyperglycemia.

BACKGROUND: Toothbrushing is a health-related lifestyle habit and has been reported to contribute not only to oral health but also to some parameters of general health; however, little research has been conducted to understand the association of the frequency and timing of toothbrushing with the development of comprehensive metabolic abnormalities, with consideration of oral health condition. In this study, using longitudinal data, we examined this association in Japanese adults, adjusting for periodontal condition. METHODS: A 5-year longitudinal study was performed with 4,537 participants between 35 and 64 years old who underwent an annual dental examination in both 2003 and 2008. Data about toothbrushing habits and metabolic abnormalities, such as obesity, hyperglycemia, diabetes, hypertension, hypertriglyceridemia, and low levels of high-density lipoprotein-cholesterol, were analyzed using Poisson regression analysis. RESULTS: The percentage of participants with a toothbrushing frequency ≤1 time/day was 29.4%, and that for those not brushing their teeth at night was 21.4%. The incidences of obesity and hyperglycemia after 5 years were 5.5% and 28.4%, respectively. A toothbrushing frequency ≤1 time/day was associated with development of obesity (prevalence rate ratio [PRR] 1.77; 95% confidence interval [CI], 1.12-2.80), after adjusting for periodontal condition and potential risk factors. A significant association between not brushing teeth at night and hyperglycemia (PRR 1.30; 95% CI, 1.02-1.66) was observed in participants with toothbrushing frequency of 1 time/day. No association was found between toothbrushing habits and other metabolic abnormalities. CONCLUSIONS: This study suggests that toothbrushing habits are associated with the development of obesity and hyperglycemia.

Relationship of toothbrushing to metabolic syndrome in middle-aged adults.

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.

Decreased cognitive function is associated with dysphagia risk in nursing home older residents.

OBJECTIVE: To examine the association between cognitive function and dysphagia risk among Japanese nursing home residents. BACKGROUND: Reduction in cognitive function can influence the intake of food during swallowing, and may be an aggravating factor in dysphagia. METHODS: This cross-sectional study included 236 residents aged ≥60 years from eight nursing homes. Screening of dysphagia, especially aspiration risk, was conducted using the Modified Water Swallow Test, whose scores from one to three were classified as at risk of dysphagia. Cognitive function was evaluated using Mini-Mental State Examination (MMSE). Number of teeth and occlusal support were evaluated by clinical examination. The participants were stratified into dentulous and edentulous groups, because the number of teeth could influence swallowing function. The odds ratio (OR) and 95% confidence interval (CI) for dysphagia risk based on the scores of MMSE were calculated using logistic regression. Demographic characteristics, activity of daily living, comorbidities, health behaviour and occlusal support were used as covariates. RESULTS: Among the 236 participants (111 dentulous participants and 125 edentulous participants) included in our analysis, 16.9% belonged to risk of dysphagia. Dentulous participants with higher scores of MMSE tended to have significantly lower odds of dysphagia risk after adjusting for covariates (OR = 0.87, 95% CI = 0.80-0.96). Despite the lack of significant differences, edentulous participants with higher score of MMSE tended to have lower odds of dysphagia risk (OR = 0.92, 95% CI = 0.83-1.00). CONCLUSION: Decreased cognitive function may be an independent predictor of dysphagia among dentulous and edentulous adults.

Exploration of bacterial species associated with the salivary microbiome of individuals with a low susceptibility to dental caries.

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.

Prediction for Improvement of Liver Function after Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices to Manage Portosystemic Shunt Syndrome.

PURPOSE: To investigate predictive factors and cutoff value of transient elastography (TE) measurements for assessing improvement in liver function after balloon-occluded retrograde transvenous obliteration (BRTO) for gastric varices (GV). MATERIALS AND METHODS: Retrospective analysis was performed of 50 consecutive patients followed for > 3 months after BRTO, who had undergone TE before BRTO between January 2011 and February 2015. The correlation between change in liver function (total bilirubin, albumin, and prothrombin time) and baseline liver function values and liver stiffness measurement (LSM) by TE was evaluated by Pearson correlation test. Receiver operating characteristic curves were used to determine cutoff values for discriminating between patients who had improved liver function and patients who did not. The time interval from BRTO to aggravation of esophageal varices (EV) (worsening morphology, development of new varices, or variceal rupture) grouped by cutoff values was also analyzed. RESULTS: Serum albumin was significantly improved at 3 months after BRTO (3.57 g/dL vs 3.74 g/dL, P < .001). There was a significant negative correlation between change in albumin and baseline LSM (r = -0.50, P < .001). The best cutoff point for LSM was ≤ 22.9 kPa, with sensitivity and specificity of 78.4% and 69.2%, respectively, for predicting which patients would have improved albumin after BRTO. Among 33 patients, 29 (88%) patients had improved albumin. The 1-year progression rate of EV after BRTO was 13.6% in patients with LSM ≤ 22.9 kPa. CONCLUSIONS: The predictive factor for improvement in albumin after BRTO was lower LSM (≤ 22.9 kPa) using TE.

Tooth loss and metabolic syndrome in middle-aged Japanese adults.

AIM: Metabolic syndrome is associated with periodontal disease and dental caries; however, little attention has been given to the association between metabolic syndrome and tooth loss, which is the endpoint of these two diseases. This study examined this association in middle-aged adults over a 5-year period. METHODS: A retrospective study was performed in 2107 participants (1718 males and 389 females) aged 35-60 years who underwent annual dental check-ups, to evaluate tooth loss and metabolic components, including obesity, elevated triglycerides, blood pressure, fasting glucose, and reduced high-density lipoprotein. Logistic regression analysis was performed to evaluate the association between metabolic syndrome (≥3 components) at the baseline examination and tooth loss. RESULTS: Over a 5-year period, 10.8% of the participants lost at least one tooth. Compared to those with no metabolic components, participants with ≥3 components had an increased risk of tooth loss (odds ratio = 1.54; 95% confidence interval: 1.01-2.37), adjusting for age, gender, dental caries experience, attachment loss, oral hygiene status, number of teeth, tooth brushing frequency, smoking, and occupational status. CONCLUSIONS: Metabolic syndrome was associated with the incidence of tooth loss among middle-aged adults.

Porphyromonas pasteri sp. nov., isolated from human saliva.

A bacterial strain, designated KUFDS01T, isolated from human saliva was characterized using a polyphasic taxonomic approach that included analysis of physiological and biochemical features, cellular fatty acid profiles and phylogenetic position based on 16S rRNA gene sequence analysis. Cells of the strain were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-stain-negative rods. Growth of the strain was inhibited on medium containing 20% bile. The 16S rRNA gene sequence analysis showed that the strain was a member of the genus Porphyromonas. Strain KUFDS01T was closely related to Porphyromonas catoniae JCM 13863T (96.6% sequence similarity). An hsp60 gene sequence analysis indicated that strain KUFDS01T was different from P. catoniae JCM 13863T, with a sequence similarity value of 87.8%. The major cellular fatty acids of strain KUFDS01T were C16 : 0, iso-C15 : 0, anteiso-C15 : 0, C18 : 2ω6, 9c and C18 : 1ω9c. The DNA G+C content of strain KUFDS01T was 57.7 ± 0.66 mol%. On the basis of these data, strain KUFDS01T represents a novel species of the genus Porphyromonas, for which the name Porphyromonas pasteri sp. nov. is proposed. The type strain of P. pasteri is KUFDS01T ( = JCM 30531T = CCUG 66735T).

Serum antibody to Porphyromonas gingivalis and periodontitis progression: the Hisayama Study.

AIM: To assess the effectiveness of serum titres of antibody to Porphyromonas gingivalis in the prediction of periodontitis progression in a community-dwelling adult population. MATERIALS AND METHODS: This 4-year follow-up cohort study included 183 Japanese individuals (75 men and 108 women) aged 40-49 years. The clinical attachment level was measured at two sites on all teeth present at baseline and follow-up, and periodontitis progression was defined as progression in attachment loss of ≥3 mm at ≥2 measurement sites. Serum titres of antibody to Porphyromonas gingivalis were evaluated at baseline and served as the primary predictor variable for periodontitis progression. RESULTS: Periodontitis progression was found in 8.7% subjects. In a multivariate logistic regression model, higher titres of antibody to Porphyromonas gingivalis and male gender were significantly associated with greater odds of periodontitis progression, even after adjustment for other confounding variables (titres of antibody to Porphyromonas gingivalis per 10 units: odds ratio, 1.66; 95% confidence interval, 1.16-2.36; male gender: odds ratio, 4.13; 95% confidence interval, 1.20-14.27). CONCLUSIONS: Elevated serum titres of antibody to Porphyromonas gingivalis may be a risk factor for periodontitis progression.

A case of ß-catenin-positive hepatocellular adenoma with MR imaging sign of diffuse intratumoral fat deposition.

Hepatocellular adenoma (HCA) is a rare primary benign tumor of the liver, which occurs predominantly in young and middle-aged women. Recently, the subclassification of HCA was proposed by the Bordeaux group. Subsequently, characteristic radiological and clinical features have been revealed in each HCA subtype. According to the previous literature, diffuse intratumoral fat deposition is a very common finding in hepatocyte nuclear factor 1α-negative HCA, but this finding has been reported in ß-catenin-positive HCA in the literature for only one case. In this case report, we report the second case of ß-catenin-positive HCA with MR imaging sign of diffuse intratumoral fat deposition, confirmed immunohistologically on the basis of a surgical specimen. In addition, our case showed hypovascularity and isointensity on the hepatobiliary phase which have been reported as characteristic findings in ß-catenin-positive HCA. Diffuse intratumoral fat deposition can be observed in ß-catenin-positive HCA, which has a greater probability of malignant transformation than other types of HCA.

Chewing xylitol gum improves self-rated and objective indicators of oral health status under conditions interrupting regular oral hygiene.

Chewing xylitol gum provides oral health benefits including inhibiting Streptococcus mutans plaque. It is thought to be especially effective in conditions where it is difficult to perform daily oral cleaning. Our study aim was to determine the effects of chewing xylitol gum on self-rated and objective oral health status under a condition interfering with oral hygiene maintenance. A randomized controlled intervention trial was conducted on 55 healthy ≥ 20-year-old men recruited from the Japan Ground Self Defense Force who were undergoing field training. Participants were randomly assigned to a test group (chewing gum; n = 27) or a control group (no gum; n = 28) and the researchers were blinded to the group assignments. The Visual Analog Scale (VAS) scores of oral conditions subjectively evaluated oral health, and the stimulated salivary bacteria quantity objectively evaluated oral health 1 day before field training (baseline) and 4 days after the beginning of field training (follow-up). VAS scores of all three oral conditions significantly increased in the control group (malodor: p < 0.001; discomfort: p < 0.001; dryness: p < 0.001), but only two VAS scores increased in the test group (malodor: p = 0.021; discomfort: p = 0.002). The number of salivary total bacteria significantly increased in the control group (p < 0.01), while no significant change was observed in the test group (p = 0.668). Chewing xylitol gum positively affects self-rated and objective oral health status by controlling oral hygiene under conditions that interfere with oral hygiene maintenance.

A novel gene involved in the survival of Streptococcus mutans under stress conditions.

A Streptococcus mutans mutant defective in aciduricity was constructed by random-insertion mutagenesis. Sequence analysis of the mutant revealed a mutation in gidA, which is known to be involved in tRNA modification in Streptococcus pyogenes. Complementation of gidA by S. pyogenes gidA recovered the acid tolerance of S. mutans. Although the gidA-inactivated S. pyogenes mutant exhibited significantly reduced expression of multiple extracellular virulence proteins, the S. mutans mutant did not. On the other hand, the gidA mutant of S. mutans showed reduced ability to withstand exposure to other stress conditions (high osmotic pressure, high temperature, and bacitracin stress) besides an acidic environment. In addition, loss of GidA decreased the capacity for glucose-dependent biofilm formation by over 50%. This study revealed that gidA plays critical roles in the survival of S. mutans under stress conditions, including lower pH.

Incidence of abnormal retropharyngeal lymph nodes in sinonasal malignancies among adults.

INTRODUCTION: The aim of this study is to investigate the relationship between abnormal retropharyngeal lymph nodes (RPLNs) and sinonasal malignancies among adults. METHODS: Magnetic resonance and computed tomography images from 89 patients over 20 years old who were all histopathologically confirmed to have sinonasal malignancies from September 2001 to April 2014 were assessed retrospectively. Abnormal RPLNs were determined as those >5 mm in shortest axis or showing heterogeneous enhancement on axial images. Locations of sinonasal malignancies were categorized using the anterior border of the pterygopalatine fossa as a boundary: (a) anterior lesions, only present anterior to the boundary, or (b) posterior lesions, present or extending posterior to the boundary. Fisher's exact test was used for the analysis of the relationship between frequency of abnormal RPLNs and lesion location. RESULTS: Abnormal RPLNs were present in 13 of 89 patients (15%), including 6 of 41 squamous cell carcinomas (15%), 4 of 24 malignant lymphomas (17%), 3 of 5 olfactory neuroblastomas (60%), and 0 of 19 others (0%). Four of the 39 patients (10%) with anterior lesions showed abnormal RPLNs, compared to 9 of 50 patients (18%) with posterior lesions. No significant difference in frequency of abnormal RPLNs was apparent between anterior and posterior lesions (P = 0.37). CONCLUSIONS: In primary sinonasal malignancies among adults, the highest incidence of abnormal RPLNs was seen with olfactory neuroblastoma. The frequency of abnormal RPLNs was unaffected by the location of sinonasal malignancies among adults.

Development and establishment of oral microbiota in early life.

BACKGROUND: The oral microbiota has recently attracted attention owing to its association with oral and systemic diseases. Accordingly, gaining an understanding of oral microbiota development and the factors influencing it can contribute to preventing the establishment of dysbiotic oral microbiota and, eventually, oral microbiota-related diseases. HIGHLIGHT: In this review, we highlight the results of a longitudinal project focusing on oral microbiota development during early life. At 4 months of age, the oral microbiota of infants was found to differ considerably from the maternal oral microbiota, even though infants acquire oral bacteria from their mothers. At 18 months, although the infant microbiota is still not completely comparable with that of adults, from 4 to 18 months, there is a rapid phase of development, during which the microbial composition undergoes considerable change to a profile more similar to that in adults. During this development, the infant oral microbiota converges into two different profiles with adult-like traits, namely, Streptococcus salivarius- and Neisseria-dominant profiles. This divergence is strongly influenced by dietary habits, with a frequent intake of sweetened beverages being associated with an S. salivarius-dominant profile, which is suspected to be implicated in oral and systemic diseases. CONCLUSION: The foundation of the adult oral microbiota may be established by 18 months of age, and the developmental period from 4 to 18 months may be an appropriate period during which to modify the microbial balance to obtain a desirable healthy state. In particular, dietary habits during this period warrant close attention.

Oral-to-rectum microbial transmission in orthopedic patients without a history of intestinal disorders.

The enrichment of oral taxa in the gut has recently been reported as a notable alteration in the microbial balance in patients with intestinal disorders. However, translocation in populations without such diseases remains controversial. In this study, we examined 49 pairs of tongue and rectal samples collected from orthopedic patients without a history of intestinal disorders to verify the presence of oral taxa in the rectal microbiota. The bacterial composition of each sample was determined using 16S rRNA gene sequencing and amplicon sequence variant (ASV) analysis. Although the bacterial compositions of the tongue and rectal microbiota were distinctly different, tongue ASVs were detected in 67.3% of the participants and accounted for 0.0%-9.37% of the rectal microbiota. Particularly, Streptococcus salivarius, Fusobacterium nucleatum, and Streptococcus parasanguinis were abundant in the rectal microbiota. According to the network analysis, tongue taxa, such as S. salivarius and S. parasanguinis, formed a cohabiting group with Klebsiella pneumoniae and Alistipes finegoldii in the rectal microbiota. The total abundance of tongue ASVs in the rectal microbiota was significantly higher in participants with older age, hypertension, and proton pump inhibitor (PPI) use. Our study presents an extensive translocation of oral taxa to the rectum of a population without intestinal disorders and suggests that aging, hypertension, and PPI use are associated with an increased abundance of oral taxa and potential pathogenic bacteria in the rectal microbiota.

Radiofrequency ablation and immunostimulant OK-432: combination therapy enhances systemic antitumor immunity for treatment of VX2 lung tumors in rabbits.

PURPOSE: To evaluate whether antitumor immunity is enhanced systemically by combining radiofrequency ablation (RFA) and local injection of an immunostimulant, OK-432. MATERIALS AND METHODS: Experiments were approved by the institutional animal care committee. Experimental Japanese rabbits inoculated with VX2 tumors in the lung and the auricle were randomized into four groups of eight: control (supportive care), RFA (RFA of lung tumor), OK-432 (direct injection of OK-432 into lung tumor), and combination therapy (lung RFA and direct OK-432 injection into lung tumor). All procedures were performed 1 week after implantation of VX2 tumors (week 1). In addition, a VX2 tumor rechallenge test was performed in the RFA and combination therapy groups. Survival time was evaluated by means of the Kaplan-Meier method and by using the log-rank test for intergroup comparison. Mean auricle tumor volumes were calculated every week. Specific growth rates (SGRs) were calculated and compared by using the Mann-Whitney test. RESULTS: The median survival times of the control, RFA, OK-432, and combination therapy groups were 23, 36.5, 46.5, and 105 days, respectively. Survival was significantly prolonged in the combination therapy group when compared with the other three groups (P <.05). The mean auricle tumor volume decreased only in the combination therapy group. The mean auricle tumor volumes of the combination therapy group from week 1 to week 7 were 205, 339, 264, 227, 143, 127, and 115 mm(3). SGR in the combination therapy group became significantly smaller than those in the other three groups (P < .05). In the rechallenge test, the volume of all reimplanted tumors decreased. CONCLUSION: Combining RFA with local injection of immunostimulant OK-432 may lead to indirectly activation of systemic antitumor immunity.

Relationship of periodontal clinical parameters with bacterial composition in human dental plaque.

More than 600 bacterial species have been identified in the oral cavity, but only a limited number of species show a strong association with periodontitis. The purpose of the present study was to provide a comprehensive outline of the microbiota in dental plaque related to periodontal status. Dental plaque from 90 subjects was sampled, and the subjects were clustered based on bacterial composition using the terminal restriction fragment length polymorphism of 16S rRNA genes. Here, we evaluated (1) periodontal clinical parameters between clusters; (2) the correlation of subgingival bacterial composition with supragingival bacterial composition; and (3) the association between bacterial interspecies in dental plaque using a graphical Gaussian model. Cluster 1 (C1) having high prevalence of pathogenic bacteria in subgingival plaque showed increasing values of the parameters. The values of the parameters in Cluster 2a (C2a) having high prevalence of non-pathogenic bacteria were markedly lower than those in C1. A cluster having low prevalence of non-pathogenic bacteria in supragingival plaque showed increasing values of the parameters. The bacterial patterns between subgingival plaque and supragingival plaque were significantly correlated. Chief pathogens, such as Porphyromonas gingivalis, formed a network with other pathogenic species in C1, whereas a network of non-pathogenic species, such as Rothia sp. and Lautropia sp., tended to compete with a network of pathogenic species in C2a. Periodontal status relates to non-pathogenic species as well as to pathogenic species, suggesting that the bacterial interspecies connection affects dental plaque virulence.