The relationship between the uptake of alveolar bone inflammation and of cervical lymph nodes on fluoro-2-deoxy-D-glucose positron emission tomography.

OBJECTIVES: To elucidate the relationships between the maximum standardized uptake value (SUVmax) of alveolar bone and those of lymph nodes (LNs) around the neck on 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET). METHODS: The SUVmax values of alveolar bone and of level IA, level IB, and level IIA LNs of 174 patients, including those with and without active odontogenic inflammation, on PET/CT performed for a health check were retrospectively evaluated. The upper and lower jaws were divided into four blocks (right maxilla, left maxilla, right mandible, and left mandible). The SUVmax values of each block and of the LNs were calculated. The differences in the SUVmax of each LN level between patients with and without odontogenic inflammation, and the relationship between the SUVmax values of alveolar bone and of the LNs were analysed statistically. RESULTS: Significant differences in SUVmax values of bilateral level IB and IIA LNs were found between patients with and without odontogenic inflammation (Mann-Whitney U test: right level IB, P = .008; left level IB, P = .006; right level IIA, P < .001; left level IIA, P = .002), but not in bilateral level IA LNs (Mann-Whitney U test: right level IA, P = .432; left level IA, P = .549). The inflammatory site with the highest SUVmax in level IB LNs was the ipsilateral mandible (multivariate analysis: right, beta = 0.398, P < .001; left, beta = 0.472, P < .001), and the highest SUVmax in level IIA LNs was the ipsilateral maxilla (multivariate analysis: right, beta = 0.223, P = .002; left, beta = 0.391, P < .001). CONCLUSIONS: The SUVmax values of level IB and IIA LNs were associated with a tendency towards a higher SUVmax value of alveolar bone on 18F-FDG-PET.

Slow starch hydrolysis of non-glutinous rice flour and potato starch heated with taxifolin: contribution of proteins to the former and longer amylose to the latter.

Taxifolin (dihydroquercetin), which has various pharmacological functions, is contained in edible plants. Some taxifolin-containing foodstuffs such as adzuki bean and sorghum seeds are cooked by themselves and with other starch-containing ingredients. In this study, non-glutinous rice flour (joshin-ko) and potato starch were heated with taxifolin. The heating resulted in the slowdown of pancreatin-induced hydrolysis of suspendable starch in joshin-ko and soluble starch in potato starch. The products of taxifolin formed by the heating such as quercetin were combined with starch during the heating and/or retrogradation, which was converted into the suspendable starch in joshin-ko and the soluble starch in the potato. Taking the difference in protein content and amylose chain length between joshin-ko and potato starch into account, the slowdown is discussed to be due to the binding of the reaction products of taxifolin to proteins in suspendable starch in joshin-ko and to soluble amylose in potato starch.

Periodontal status is associated with oral function in community-dwelling older adults, independent of dentition status.

OBJECTIVE: To determine whether periodontal status is associated with oral function, including masticatory performance and occlusal force, among community-dwelling older adults. BACKGROUND: Although a potential association between periodontal status and oral function has been reported, variations in the root surface area (RSA) of each tooth have not been considered. METHODS: We used data from a population-based study involving community-dwelling older adults. The RSA with periodontal ligament (RSA-PL), which quantifies the RSA attached to the periodontal ligament and alveolar bone, was calculated based on full-mouth periodontal examination. Masticatory performance was assessed using spectrophotometric measurement of the color (a* value) of color-changing chewing gum. The bilateral maximal occlusal force (MOF) was measured using a pressure-sensitive sheet and dedicated software. The associations of the RSA-PL, a quantitative marker of periodontal tissue support, with the a* value and MOF were assessed using linear regression models. RESULTS: The analyses included data from 250 adults [60.8% women; age, mean (standard deviation) 82.5 (5.0) years]. On average, the study participants had an RSA-PL of 26.3 cm2 , a* value of 25.0, and an MOF value of 555.1 N. After adjustments for potential confounders, including dentition status, age, sex, dental visit regularity, smoking status, physical activity level, depressive symptoms, a history of stroke or diabetes mellitus, and body mass index, the RSA-PL was found to be associated with the a* value [coefficient (per 1 cm2 increase): 0.16, 95% confidence interval (CI) 0.10-0.22)] and MOF (coefficient: 9.2, 95% CI 5.3-13.1). CONCLUSION: This study demonstrated that greater amounts of remaining tooth-supporting structures, indicated by higher RSA-PL values, were associated with better masticatory performance and a higher occlusal force among community-dwelling older adults.

Pancreatin-induced liberation of starch/cyanidin 3-O-glucoside complexes from rice cooked with black soybean that exhibit slow hydrolysis.

Cyanidin 3-O-glucoside (C3G), which has various health-promoting functions, is contained in black soybean (BSB). In Japan and Korea, BSB is cooked with rice and the cooked rice appears purplish in colour. In this study, BSB was cooked with glutinous rice, non-glutinous rice, and high-amylose rice. The amount of C3G detected in high-amylose rice was greater than that detected in glutinous rice, suggesting that C3G combined more efficiently with amylose than with amylopectin. Pancreatin induced the liberation of starch/C3G complexes from the purplish cooked rice, and rate of the liberation was in the following order; glutinous rice < non-glutinous rice < high-amylose rice. The amylose/C3G complexes liberated from high-amylose rice was hydrolysed slowly, while the amylopectin/C3G complexes liberated from glutinous rice were hydrolysed into smaller amylopectin/C3G complexes that were difficult to further hydrolysis. Thus, C3G may be useful for preparing foods whose starch hydrolysis is slow.

Association between periodontitis and the Mediterranean diet in young Moroccan individuals.

BACKGROUND & OBJECTIVES: Adherence to the Mediterranean diet (MedDiet) has been reported to be associated with a lower risk of various chronic diseases. This cross-sectional study aimed to investigate the potential association between adherence to the MedDiet and periodontitis, which is highly prevalent in young Moroccan individuals. METHODS: We evaluated 1075 Moroccan individuals (72% women, mean [standard deviation] age = 20.2 [1.5] years). Adherence to the MedDiet was assessed using the MedDiet score (MDS) based on the frequency of intake of eight food groups (vegetables, legumes, fruits, cereals or potatoes, fish, red meat, dairy products, and olive oil). A value of 0 (unhealthy) or 1 (healthy) was assigned to each food group, and the MDS (range, 0-8 points) was generated by adding the individual scores, with a higher score indicating better adherence to the MedDiet. The logistic regression model was used to evaluate the MDS (high [5-8 points]/low [0-4 points]) and each component score (1/0) with the presence of periodontitis, which was determined through full-mouth periodontal examinations. Age, sex, and oral health behavior were considered as potential confounders. RESULTS: In total, 693 (64.5%) study participants showed high MDSs. Periodontitis was observed in 71 (6.6%) participants. No significant association between MDS and periodontitis was observed. Nonetheless, olive oil consumption, a component of the MDS, showed a significant inverse association with periodontitis (adjusted odds ratio = 0.55; 95% confidence interval, 0.32-0.96). CONCLUSIONS: The MedDiet was not significantly associated with periodontitis among young Moroccans. However, frequent consumption of olive oil may have a protective effect against periodontitis, although the temporal association needs to be clarified in further studies.

A 5-year longitudinal association between dietary fermented soya bean (natto) intake and tooth loss through bone mineral density in postmenopausal women: The Yokogoshi cohort study.

OBJECTIVE: In this 5-year cohort study, we aimed to determine whether the intake of natto, a fermented soya bean food product, has an indirect effect on tooth loss incidence through BMD changes among postmenopausal women. BACKGROUND: Evidence indicates (1) that natto has a beneficial effect on bone health and (2) that a decrease in bone mineral density (BMD) is associated with tooth loss. METHODS: The study recruited 435 postmenopausal women (average age = 64.2 years). Natto intake (exposure) was assessed at baseline using a food frequency questionnaire. Lumbar spine BMD and number of teeth were measured at baseline and 5-year follow-up. BMD change (mediator) and the number of teeth lost (outcome) over time were calculated. The mediation model consisted of these 3 variables. Mediation analysis was performed to test the indirect effect of the natto intake measured through BMD change on tooth loss. RESULTS: During the study, the mean number of teeth lost was 1.2 (standard deviation = 1.8), and the mean BMD decline was 2.5% (standard deviation = 7.1). After adjusting for potential confounders, increasing habitual natto intake was significantly indirectly associated with a lower incidence of tooth loss mediated by BMD change (incidence rate ratio of tooth loss among women with "≥1 pack/day" natto intake was 0.90 [95% confidence interval = 0.82-0.99] compared to those with natto consumption of "rarely"). CONCLUSIONS: Dietary natto intake is significantly indirectly associated with a lower incidence of tooth loss among postmenopausal women, and systemic bone density could be a mediator of this association.

[Regular dental visits and changes in oral health among high school students during the coronavirus disease pandemic: A study using data from medical checkup at a school].

Objective　Continuous oral health care and regular dental visits are important for maintaining oral health. As a result of the high communicability of the coronavirus disease (COVID-19), individuals are reluctant to visit medical institutions. It is as yet unclear how the oral health of the population has been affected by the interruption of regular medical services during the COVID-19 pandemic. This study aimed to examine the association between the status of regular dental visits and changes in oral health among high school students during the pandemic using data from routine medical checkups conducted at a school, as well as data obtained from a questionnaire-based survey conducted simultaneously with medical checkups.Methods　This study included 878 participants (comprising freshmen and sophomores) during the 2019 academic year from a high school in Fukuoka prefecture, Japan. Data on the frequency of dental checkups and anxiety related to dental visits during the pandemic was obtained through a questionnaire-based survey. Changes in dental health and gingival status between 2019 and 2020 were determined using data from routine medical checkups at the school. Poisson regression analysis with robust standard errors was used to evaluate the association between changes in dental health and gingival status and the status of regular dental visits.Results　Of 878 participants, 417 (47.5%) did not have regular dental visits, 320 (36.4%) continued to have regular dental visits, and 141 (16.1%) had interrupted regular dental visits during the pandemic. In the interrupted regular dental visit group, 30.5% of participants were anxious about visiting a dental institution, which was a significantly higher proportion than other groups. Of the 521 participants who did not have gingival inflammation at the time of dental checkup in 2019, gingival inflammation at the time of dental checkup in 2020 was observed in 31.0% of participants having no regular dental visits, 20.2% participants having regular dental visits, and 38.2% participants having interrupted regular dental visits. The multivariable adjusted incidence rate ratios were 1.95 [95% confidence interval (CI), 1.34-2.84] in the interrupted regular dental visit group and 1.50 (95%CI,1.07-2.10) in the no regular dental visit group. There was no significant association between interruption of regular dental visits and changes in dental health status.Conclusion　The study results showed that there was a significant association between interruptions in regular dental visits and anxiety related to dental visits during the COVID-19 pandemic, and that a higher proportion of participants who had interruptions in regular dental visits had gingival inflammation at the time of the medical checkup at the school.

Combined effect of poor appetite and low masticatory function on sarcopenia in community-dwelling Japanese adults aged ≥ 75 years: A 3-year cohort study.

OBJECTIVE: This study aimed to investigate the longitudinal association of the combination of poor appetite (PA) and low masticatory function (LMF) with sarcopenia in community-dwelling older adults. METHODS: In total, 173 community-dwelling Japanese adults aged ≥ 75 years participated in the 3-year cohort study. Appetite assessment using the Simplified Nutritional Appetite Questionnaire (SNAQ) and masticatory function assessment using spectrophotometric measurement of differences in gum colour before and after masticating colour-changeable chewing gum (ΔE*ab) were performed at baseline. SNAQ score of ≤ 14 was defined as PA. The lowest tertile of ΔE*ab was defined as LMF. Follow-up examinations were administered annually over a 3-year period to determine sarcopenia incidence, which was defined by the criteria proposed by the Asian Working Group for Sarcopenia. Adjusted hazard ratios (HRs) of sarcopenia incidence according to the presence of PA and LMF were calculated using Cox proportional hazards regression models. RESULTS: At baseline, 81 participants (46.8%) had neither PA nor LMF, 34 (19.7%) had PA alone, 35 (20.2%) had LMF alone, and 23 (13.3%) had both PA and LMF. On follow-up, 31 participants (17.9%) developed sarcopenia. After adjusting for covariates, the adjusted HR for sarcopenia in participants with both PA and LMF was 4.4 (95% confidence interval = 1.6-12.2) compared with those without PA or LMF. PA or LMF alone was not significantly associated with sarcopenia development. CONCLUSIONS: Coexisting PA and LMF increase the risk of sarcopenia development among community-dwelling Japanese adults aged ≥ 75 years.

The relationship between masticatory performance and intakes of foods and nutrients in Japanese male workers: A cross-sectional study.

BACKGROUND: Although many studies have been conducted on the relationship between masticatory performance and nutrient ingestion in the elderly, few large-scale studies have been carried out using relatively young individuals. OBJECTIVES: The objective of this study was to clarify the association between the masticatory performance evaluated by the gummy-jelly test, not by visual examination, and nutrient ingestion state based on the brief self-administered diet history questionnaire (BDHQ). METHODS: This was a cross-sectional survey of 540 male workers. Somatometry, blood pressure measurement, blood test and medical interview were performed as a periodic health check-up. In the dental check-up, an oral examination, gummy-jelly test (glucosensor) and survey of ingested food and nutrients using BDHQ were performed. The participants were classified into two groups with low and normal values of masticatory performance. Participants with a score on the gummy-jelly test below 150 mg/dL or 150 mg/dL or higher were included in the low and normal groups, respectively. RESULTS: Two hundred and forty-eight participants (45.8%) had low masticatory performance, and 292 (53.2%) had normal masticatory performance. The intakes of some minerals and vitamins, such as calcium, vitamin D, vitamin B2 , small fish with bones and non-oily fish, were significantly lower in the low masticatory group than in the normal group. In contrast, the intake of sugar for coffee and tea and that of chicken were significantly higher in the low masticatory group than in the normal group. CONCLUSION: This study suggested that low masticatory performance can affect nutrient intake, which may cause non-communicable diseases.

Retraction Note: Temporal activation of anti- and pro-apoptotic factors in human gingival fibroblasts infected with the periodontal pathogen, Porphyromonas gingivalis: potential role of bacterial proteases in host signalling.

The Editor has retracted this article [1] following an investigation by the University of South Alabama which found.

Periodontitis, periodontal inflammation, and mild cognitive impairment: A 5-year cohort study.

BACKGROUND AND OBJECTIVES: Identification of modifiable factors for mild cognitive impairment (MCI) is important since individuals with MCI are at a high risk of dementia and disability. Previous studies have suggested a potential association between periodontitis and cognitive impairment, but the results remain inconclusive. We designed a 5-year longitudinal study to explore the association between MCI and periodontitis and periodontal inflammation in older adults. METHODS: This study included 179 community-dwelling dentate individuals (62 men and 117 women, average age: 80.1 years). A full-mouth periodontal examination at six sites per tooth was performed at baseline. Case definitions provided by the European Workshop in Periodontology Group C (EWP definition) and the Centers for Disease Control/American Academy of Periodontology (CDC/AAP definition) were used to define severe periodontitis. Additionally, the periodontal inflamed surface area (PISA), reflecting the amount of inflamed periodontal tissue, was calculated using clinical periodontal parameters. Follow-up cognitive examinations for MCI diagnosis were performed by neurologists 1, 2, 3, and 5 years after baseline. Odds ratios (ORs) for MCI according to the presence of periodontitis and periodontal inflammation at baseline were calculated using multilevel mixed-effects logistic regression. RESULTS: At baseline, 56.4% and 27.4% of the participants had severe periodontitis by the EWP and CDC/AAP definitions, respectively. After adjusting for follow-up period and other baseline health characteristics (age, sex, smoking status, educational level, physical activity level, obesity, depression, and diabetes), severe periodontitis by either definition was significantly associated with MCI (for the EWP definition: adjusted OR = 3.58, 95% confidence interval [CI] = 1.45-8.87; for the CDC/AAP definition: adjusted OR = 2.61, 95% CI = 1.08-6.28). Periodontal inflammation assessed by PISA was also significantly associated with a higher OR for MCI (adjusted OR = 1.05, 95% CI = 1.01-1.10, per 10-mm2 increase in PISA). CONCLUSION: Severe periodontitis and periodontal inflammation were associated with incident MCI among older community-dwelling men and women.

Porphyromonas gingivalis hydrogen sulfide enhances methyl mercaptan-induced pathogenicity in mouse abscess formation.

Porphyromonas gingivalis produces hydrogen sulfide (H2S) from l-cysteine. However, the role of H2S produced by P. gingivalis in periodontal inflammation is unclear. In this study, we identified the enzyme that catalyses H2S production from l-cysteine and analysed the role of H2S using a mouse abscess model. The enzyme identified was identical to methionine γ-lyase (PG0343), which produces methyl mercaptan (CH3SH) from l-methionine. Therefore, we analysed H2S and CH3SH production by P. gingivalis W83 and a PG0343-deletion mutant (ΔPG0343) with/without l-cysteine and/or l-methionine. The results indicated that CH3SH is produced constitutively irrespective of the presence of l-methionine, while H2S was greatly increased by both P. gingivalis W83 and ΔPG0343 in the presence of l-cysteine. In contrast, CH3SH production by ΔPG0343 was absent irrespective of the presence of l-methionine, and H2S production was eliminated in the absence of l-cysteine. Thus, CH3SH and H2S production involves different substrates, l-methionine or l-cysteine, respectively. Based on these characteristics, we analysed the roles of CH3SH and H2S in abscess formation in mice by P. gingivalis W83 and ΔPG0343. Abscess formation by P. gingivalis W83, but not ΔPG0343, differed significantly in the presence and absence of l-cysteine. In addition, the presence of l-methionine did not affect the size of abscesses generated by P. gingivalis W83 and ΔPG0343. Therefore, we conclude that H2S produced by P. gingivalis does not induce inflammation; however, H2S enhances inflammation caused by CH3SH. Thus, these results suggest the H2S produced by P. gingivalis plays a supportive role in inflammation caused by methionine γ-lyase.

Effect of lifestyle on 6-year periodontitis incidence or progression and tooth loss in older adults.

AIM: To evaluate the longitudinal association of combined healthy lifestyle factors with incidence or progression of periodontitis and tooth loss in older adults. MATERIALS AND METHODS: This 6-year study included 374 Japanese 70-year olds with 7,157 teeth, from a source eligible baseline population of 554 individuals. Four lifestyle factors-cigarette smoking, physical activity, relative weight, and dietary quality-were scored as healthy (1 point) or unhealthy (0 point). Adding the individual scores generated the "healthy lifestyle score" (0-4 points). Multilevel mixed-effects logistic regression models were applied to evaluate tooth-specific associations between the baseline healthy lifestyle score and the incidence or progression of periodontitis (increase in clinical attachment loss ≥3 mm) and tooth loss. RESULTS: After 6 years, 19.0% of the teeth exhibited periodontitis incidence or progression and 8.2% were lost. Compared with a healthy lifestyle score of 0-1 (least healthy), the highest score (4 points) was associated with a significantly lower tooth-specific risk of periodontitis (adjusted odds ratio = 0.32; 95% confidence interval: 0.16-0.62) and tooth loss (adjusted odds ratio = 0.42; 95% confidence interval: 0.23-0.77). CONCLUSIONS: Simultaneous adherence to multiple healthy lifestyle factors significantly lowers the risk of incidence or progression of periodontitis and tooth loss in older adults.

Periodontal disease and pneumonia mortality in haemodialysis patients: A 7-year cohort study.

AIM: To evaluate the association between periodontal disease and pneumonia mortality in haemodialysis patients. MATERIALS AND METHODS: This prospective cohort study included 211 patients (mean age, 64.4 years) undergoing haemodialysis at a single medical centre. The patients underwent a baseline clinical dental examination in 2008 and were then followed up until July 2015. Periodontal disease was defined as the presence of clinical attachment loss of ≥4 mm in ≥30% of the probed sites. The primary endpoint, that is death from pneumonia, was determined by reviewing death certificates and was analysed using the competing-risks regression model. RESULTS: At baseline, 92 patients (43.6%) had periodontal disease. The median follow-up period was 84 months (interquartile range, 36-86 months). Of the 68 deaths that occurred, 21 were from pneumonia. The multivariable competing-risks regression model showed that periodontal disease was significantly associated with death from pneumonia (adjusted subhazard ratio, 3.49; 95% confidence interval, 1.14-10.64), after adjusting for other baseline health characteristics. CONCLUSIONS: The results of this study suggest that periodontal disease is independently associated with pneumonia mortality in haemodialysis patients. Future studies evaluating the potential effect of oral interventions for periodontal health improvement on pneumonia in haemodialysis patients would be of great interest.

Hyposalivation and 10-year all-cause mortality in an elderly Japanese population.

OBJECTIVE: To evaluate the association of salivary flow rate with all-cause mortality among older Japanese adults. We hypothesised that hyposalivation would be a marker for mortality. BACKGROUND: Hyposalivation, which is an objectively measurable decrease in salivary flow, is highly prevalent among older adults. It is associated with malnutrition and poor general health. METHODS: The study population comprised 600 community-dwelling Japanese adults (306 men and 294 women), who were 70 years old at baseline. They underwent stimulated salivary flow rate (SSFR) measurements and were followed up during a 10-year study period. After stratification by sex, the hazard ratios of all-cause mortality were estimated using Cox proportional hazards regression analysis comparing groups with and without hyposalivation (ie, SSFR < 0.7 mL/min). RESULTS: The baseline prevalence of hyposalivation was 27.8% (85/306) among men and 47.3% (139/294) among women. During a mean (standard deviation) follow-up period of 104 (27) months, 80 deaths occurred: 60 (75.0%) deaths among men and 20 (25.0%) deaths among women. After adjusting for the number of remaining teeth, smoking status, exercise, hypoalbuminemia, diabetes and cardiovascular disease, hyposalivation at baseline was significantly associated with all-cause mortality among men (adjusted hazard ratio, 1.71; 95% confidence interval, 1.01-2.89). In contrast, no association between SSFR and all-cause mortality existed among women. CONCLUSION: Hyposalivation could be a marker for all-cause mortality among older community-dwelling Japanese men. Future studies investigating the association between SSFR and cause-specific mortality are warranted.

Jaw-opening force test to screen for Dysphagia: preliminary results.

OBJECTIVE: To assess the jaw-opening force test (JOFT) for dysphagia screening. DESIGN: Criterion standard. SETTING: University dental hospital. PARTICIPANTS: Patients complaining of dysphagia (N=95) and with symptoms of dysphagia with chronic underlying causes (mean age ± SD, 79.3±9.61y; range, 50-94y; men: n=49; mean age ± SD, 77.03±9.81y; range, 50-94y; women: n=46; mean age ± SD, 75.42±9.73y; range, 51-93y) admitted for treatment between May 2011 and December 2012 were included. INTERVENTIONS: None. MAIN OUTCOME MEASURES: All patients were administered the JOFT and underwent fiberoptic endoscopic evaluation of swallowing (FEES). The mean jaw-opening strength was compared with aspiration (ASP) and pharyngeal residue observations of the FEES, which was used as the criterion standard. RESULTS: A receiver operating characteristic (ROC) curve analysis was performed. Forces of ≤3.2kg for men and ≤4kg for women were appropriate cutoff values for predicting ASP with a sensitivity and specificity of .57 and .79 for men and .93 and .52 for women, respectively. Based on the ROC analyses for predicting pharyngeal residue, forces of ≤5.3kg in men and ≤3.9kg in women were appropriate cutoff values, with a sensitivity and specificity of .80 and .88 for men and .83 and .81 for women, respectively. CONCLUSIONS: The JOFT could be a useful screening tool for predicting pharyngeal residue and could provide useful information to aid in the referral of patients for further diagnostic imaging testing. However, given its low sensitivity to ASP the JOFT should be paired with other screening tests that predict ASP.

Association between oral frailty and nutritional status among hemodialysis patients aged ≥50 years.

AIM: Malnutrition is a prevalent health issue among hemodialysis patients. Oral frailty, a condition characterized by impairments in multiple oral health aspects and functions, has been associated with nutritional status in the general population. We aimed to determine whether oral frailty was associated with nutritional status in hemodialysis patients aged ≥50 years. Our secondary aim was to determine the prevalence of oral frailty in this population. METHODS: This cross-sectional study included hemodialysis patients who were admitted to a single medical center. According to the Oral Frailty 5-item Checklist, oral frailty is characterized by the presence of two or more of the following criteria: (i) fewer teeth, (ii) difficulty in chewing, (iii) difficulty in swallowing, (iv) dry mouth, and (v) low articulatory oral motor skills. Patients' nutritional status was assessed using the Geriatric Nutritional Risk Index (GNRI). Multivariable ordinal logistic regression analysis was performed to assess the association between oral frailty and nutritional status (classified into three categories according to the GNRI: >98, 92-98, and <92). RESULTS: In total, 152 hemodialysis patients (55 women and 97 men) with a mean age of 70.4 years were included. The prevalence of oral frailty was 61.2%. After adjusting for health characteristics and sociodemographic background, oral frailty was associated with poor nutritional status according to the GNRI (odds ratio = 2.04, 95% confidence interval = 1.02-4.09). CONCLUSIONS: In this study, approximately 60% of hemodialysis patients aged ≥50 years exhibited oral frailty, and hemodialysis patients with oral frailty had poor nutritional status according to the GNRI. Geriatr Gerontol Int 2024; ••: ••-••.

Monitoring the prevalence of viable and dead cariogenic bacteria in oral specimens and in vitro biofilms by qPCR combined with propidium monoazide.

BACKGROUND: Streptococcus mutans and Streptococcus sobrinus are associated with the development of dental caries in humans. However, previous diagnostic systems are unsuitable for monitoring viable cell numbers in oral specimens. Assessing the relationship between the numbers of viable and dead bacterial cells and oral status is important for understanding oral infectious diseases. Propidium monoazide (PMA) has been reported to penetrate dead cells following membrane damage and to cross-link DNA, thereby inhibiting DNA amplification. In the present study, we established an assay for selective analysis of two viable human cariogenic pathogens, S. mutans and S. sobrinus, using PMA combined with real-time PCR (PMA-qPCR). RESULTS: We designed species-specific primer sets for S. mutans and S. sobrinus, generated standard curves for measuring cell numbers, and evaluated the dynamic range of the assay. To determine the effectiveness of the assay, PMA was added to viable and autoclave-killed cell mixtures. PMA treatment effectively prevented DNA amplification from dead cells. No amplification of DNA from dead cells was observed in these organisms. In addition, we applied this assay to analyze viable cell numbers in oral specimens. A significant correlation was found between the number of viable S. mutans cells in saliva and that in plaque among caries-free patients, whereas no correlation was observed between saliva and carious dentin. The total and viable cell numbers in caries-positive saliva were significantly higher than those in caries-free saliva. Finally, we analyzed the usefulness of this assay for in vitro oral biofilm analysis. We applied PMA-qPCR for monitoring viable S. mutans cell numbers in vitro in planktonic cells and oral biofilm treated with hydrogen peroxide (H2O2). In planktonic cells, the number of viable cells decreased significantly with increasing H2O2 concentration, whereas only a small decrease was observed in biofilm cell numbers. CONCLUSIONS: PMA-qPCR is potentially useful for quantifying viable cariogenic pathogens in oral specimens and is applicable to oral biofilm experiments. This assay will help to elucidate the relationship between the number of viable cells in oral specimens and the oral status.

Neutral endopeptidase regulates neurogenic inflammatory responses induced by stimulation of human oral keratinocytes with bacterial lipopolysaccharide and nicotine.

Neutral endopeptidase (NEP) is present on various epithelial cells and inactivates numerous physiologically active peptides. Neutral endopeptidase may regulate proinflammatory signals in oral mucosal epithelium. However, the function of NEP in oral mucosal epithelium is unknown. The present study investigated the action of NEP upon proinflammatory signals on human oral keratinocytes and the influence of endothelin-converting enzyme (ECE)-1, an enzyme similar to NEP, on the functions of NEP. Oral keratinocytes were cultured in medium containing inflammatory inducers [lipopolysaccharide (LPS) and nicotine], NEP inhibitors, and ECE-1/NEP inhibitors, either alone or in combination. The concentrations of substance P (SP) and interleukin-1ß (IL-1ß) were measured in the supernatant. Additionally, the concentrations of SP and IL-1ß were measured in the supernatant of cells incubated with LPS or nicotine after transfection with NEP small interfering RNA (siRNA). The concentrations of SP and IL-1ß were significantly increased in cells incubated with NEP inhibitors and, to a lesser extent, in cells incubated with ECE-1/NEP inhibitors, compared with controls (cells incubated with LPS or nicotine alone). The concentrations of SP and IL-1ß in cells transfected with NEP siRNA were significantly augmented compared with controls. In conclusion, the present study demonstrated that NEP down-regulated the levels of SP and IL-1ß produced from human oral keratinocytes, although ECE-1 may be partly related to the down-regulation.

Association between tooth loss and orodigestive cancer mortality in an 80-year-old community-dwelling Japanese population: a 12-year prospective study.

BACKGROUND: A growing body of evidence has indicated a possible association between oral and gastrointestinal (orodigestive) cancers and periodontal disease or tooth loss. However, the evidence remains contradictory. This study investigated whether tooth loss, which is indicative of poor oral health and a potential source of oral infections, is associated with death from orodigestive cancer. METHODS: The study included 656 subjects in Fukuoka prefecture, Japan, who were 80 years old at baseline in 1998. All subjects underwent oral clinical examination and answered a questionnaire to determine their background characteristics. Cause of death over the 12-year follow-up was recorded from the registers at the Public Health Centers and classified according to the WHO International Classification of Diseases. Statistical analysis of associations was performed using Kaplan-Meier and Cox multivariate regression analyses. RESULTS: A significant association was observed between tooth loss (continuous variable) and cancer death (hazard ratio (HR): 1.03, 95% confidence interval (CI): 1.00-1.07), after adjustment for potential confounders, including sex and smoking status. However, that association became insignificant in the fully adjusted model. On the other hand, tooth loss was significantly associated with orodigestive cancer (HR: 1.06, 95% CI: 1.01-1.13), even in the fully adjusted model including place of residence as a part of socioeconomic status. CONCLUSIONS: This study provides the first evidence in a prospective study in a Japanese population that tooth loss is associated with increased orodigestive cancer mortality, although the causality remains unclear.