Kyushu Dental University

Dental caries are caused by organic acids produced by cariogenic bacteria through carbohydrate metabolism. Suppression of acid production without disrupting the oral microbiome is a promising preventive strategy against dental caries. Surfactin, a naturally derived biosurfactant, has several biological activities. However, its effects on acid production by cariogenic bacteria remain unclear. In this study, the effects of surfactin on lactate production, growth, biofilm formation, and metabolic activity of Streptococcus sobrinus, were investigated. In vitro assays were performed to distinguish surfactin-mediated suppression of acidogenic metabolism from its effects on bacterial growth or biofilm formation, combined with molecular and enzymatic analyses to explore the underlying regulatory mechanisms. Surfactin significantly reduced lactate production in planktonic and biofilm-associated S. sobrinus, and it delayed environmental pH reduction in the presence of sucrose. Notably, these effects were observed without inhibition of bacterial growth or biofilm formation. There were no significant changes in the expression of lactate production-related genes, and lactate dehydrogenase activity was not inhibited by surfactin. In contrast, in the MTT assay, there was a transient reduction in metabolic activity, accompanied by delayed initiation of growth. These findings indicate that surfactin selectively attenuates acidogenicity in S. sobrinus, without markedly affecting bacterial viability or biofilm architecture, which is consistent with an anti-virulence mode of action. Although further validation in more complex oral environments and comprehensive safety assessments are required, this study provides fundamental evidence supporting the potential of naturally derived biosurfactants as a basis for future preventive strategies for caries.

Gene therapy has emerged as a promising therapeutic strategy in oncology by targeting the molecular mechanisms that drive malignant transformation. Among gene-based approaches, oncolytic viruses (OVs) are distinctive in their ability to selectively replicate within tumor cells, induce direct oncolysis, and simultaneously stimulate systemic antitumor immunity by exploiting defects in cancer cell antiviral responses. Recent studies have identified Coxsackievirus A11 (CVA11) as a highly potent immunostimulatory OV. CVA11 demonstrates strong tumor-selective replication, robust cytolytic activity, and marked induction of antitumor immune responses. Notably, CVA11 has been shown to induce complete tumor regression in human non-small cell lung cancer models. In addition, CVA11 enhances chemosensitivity in oxaliplatin-resistant colorectal cancer and may have broader applicability in treatment-refractory malignancies, including pancreatic cancer. This review summarizes current gene therapy strategies for malignant tumors with a particular focus on the biological properties and therapeutic potential of CVA11. We discuss its mechanisms of tumor selectivity, immune activation, and potential integration with chemotherapy and gene-based cancer vaccines. Collectively, these findings position CVA11 as a promising next-generation oncolytic virus for cancer gene therapy and immunotherapy.

Empathy is a crucial component in healthcare, contributing to improved patient outcomes. However, excessive empathy may lead to emotional exhaustion and reduced self-compassion. This study examined the relationship between empathy and self-compassion among dental hygiene students. A cross-sectional survey was conducted among 520 dental hygiene students from four schools in Fukuoka Prefecture, Japan. Empathy was assessed using the Japanese version of the Jefferson Scale of Empathy (JSE), while self-compassion was measured using the Japanese version of the Self-Compassion Scale (SCS). Additional data on academic year and self-rated health status were collected. Segmented regression analysis was performed to examine a potential nonlinear relationship between JSE and SCS scores. A total of 454 respondents were included in the final analysis. No significant correlation was found between JSE and SCS scores (r = 0.016, p = 0.739). However, segmented regression identified a breakpoint at JSE = 121.0 (95% CI: 119.2-122.8). Below this threshold, no significant association was observed, but above it, JSE was significantly negatively associated with SCS (β = -0.875, p < 0.01), suggesting that excessive empathy may reduce self-compassion. Additionally, students with higher perceived health status had greater self-compassion, while third-year students scored higher in empathy than lower-year students. This study revealed an online a relationship between empathy and self-compassion, with self-compassion significantly declining in students with exceptionally high empathy levels. Additionally, self-compassion was positively associated with perceived health status, while third-year students exhibited higher empathy scores.

Perceived professional suitability-students' judgment of whether they are well-suited to their profession-may shift within a semester, yet longitudinal evidence in dental hygiene education is limited. We examined 6-month changes in perceived suitability and their psychological associations. This longitudinal survey followed dental hygiene students from April to September 2025 in Kitakyushu, Japan. Of 450 eligible students, 402 responded at baseline, and 293 completed both time points. The primary outcome at 6 months was perceived suitability for being a dental hygienist, dichotomized as not well-suited/uncertain versus well-suited. Prospective associations were tested with multivariable logistic regression using April covariates. As a secondary outcome, 6-month transitions-deterioration (well-suited to not/uncertain) and improvement (not/uncertain to well-suited)-were compared by school year with McNemar's tests. First-year students showed net deterioration, whereas third-year students showed relative stability/improvement. McNemar's tests indicated net deterioration in first-year students (4 vs. 26; p<0.001) and second-year students (5 vs. 17; p=0.019), but not in third-year students (13 vs. 7; p=0.263). In the prospective model, higher baseline positive self-compassion was associated with lower odds of being not well-suited/uncertain at 6 months (OR=0.90 [0.83-0.96]; p=0.003), whereas higher HADS-D was associated with higher odds of being not well-suited/uncertain at 6 months (OR=1.11 [1.00-1.22]; p=0.044). Lower self-compassion and higher depressive symptoms at baseline were associated with later reports of being not well-suited/uncertain. These findings indicate associations between self-compassion and perceived suitability; causal inferences cannot be made from this observational study.

Malnutrition is common among individuals with intellectual disabilities, and behavioral resistance may limit access to routine oral care. This study examined the association between refusal of oral care and poor nutritional status. In this cross-sectional study, conducted between February and March 2025, we assessed 55 adults with intellectual disabilities living in two designated residential support facilities for persons with disabilities in Fukuoka, Japan. Nutritional status was evaluated using the Mini Nutritional Assessment-Short Form. Oral care refusal was identified from staff records. Functional and body composition data were obtained using the Functional Independence Measure, Barthel Index, and bioelectrical impedance analysis. The at-risk/malnourished group had significantly lower BMI, fat mass, and functional scores, and a higher rate of oral care refusal (p=0.007). Logistic regression showed that oral care refusal [OR=9.23 (95% confidence interval (CI): 1.10-77.33], lower fat mass [OR=0.78 (0.66-0.92)] were independently associated with poor nutritional status (FIM-Eating [OR=0.86 (0.53-1.39)], gender [OR=0.44 (0.08-2.27)], age [OR=0.96 (0.90-1.02)]). AUC was 0.90 (0.81-0.98). Oral care refusal may indicate increased risk of malnutrition among adults with intellectual disabilities. Larger, longitudinal studies are needed to confirm these findings.

ObjectiveThis study aimed to evaluate the prevalence of oral hypofunction among dental maintenance outpatients aged over 50 years who had completed dental treatment at least three months before and to explore the relationship among oral hypofunction, age, and underweight.BackgroundRecently, the relationship between oral function and general health, such as frailty or sarcopenia, through the mechanism of declining nutritional status, has been the focus of research. Improving oral function, such as general dental treatment, may prevent deterioration or improve overall health, but the causal relationship has not yet been fully clarified. It is useful how often the general dentist might encounter subjects with oral hypofunction in regular maintenance patients or how oral hypofunction could predict present underweight status.Materials and methodsThis cross-sectional study enrolled 107 subjects (mean age: 72.9 ± 9.2 years, 40.2% men). Oral hypofunction tests and body mass index (BMI) were used as indicators of oral function and nutrition status, respectively. Underweight was defined based on the BMI cut-off values specified in the Global Leadership Initiative on Malnutrition (GLIM) criteria for Asians. Other patient characteristics, such as medical history, the number of teeth, and functional tooth units (FTUs), were collected from the patients’ charts. The participants were classified into three groups: middle-aged (50-64 years), early older adult (65-74 years), and late older adult (≥75 years). Associations among oral hypofunction, underweight, and age were evaluated using two-way ANOVA, with additional analyses performed using general linear models (GLM) to account for potential confounders.ResultsThe overall prevalence of oral hypofunction was 50.5%, and 48.1% of the participants in the nonunderweight group (n = 81) exhibited oral hypofunction. The oral hypofunction group was significantly older than the nonoral hypofunction group (75.5 ± 7.4 versus 70.3 ± 10.1 years, p < 0.05). No significant differences in BMI status were observed among the three age groups, although functions of oral hygiene status (tongue coating index {TCI}) and oral diadochokinesis (ODK) (/ta/ and /ka/) had significant differences in some parts of the age groups. In multivariable-adjusted general linear models, age group remained significantly associated with oral diadochokinesis, and a significant interaction between age group and underweight status was observed for tongue coating index.ConclusionApproximately half of the dental outpatients in the maintenance phase in this study exhibited oral hypofunction. Oral hypofunction was significantly observed in elderly people in the dental maintenance phase. Although it could not be detected as a significant uniform association between oral hypofunction and underweight, the small underweight group limits our ability to rule out a clinically meaningful relationship.