Cerebral microbleeds (CMBs) are an important risk factor for stroke and dementia. We have shown that the collagen binding surface Cnm protein expressed on cnm-positive Streptococcus mutans is involved in the development of CMBs. However, whether the collagen binding activity of cnm-positive S. mutans is related to the nature of the CMBs or to cognitive impairment is unclear. Two-hundred seventy nine community residents (70.0 years) were examined for the presence or absence of cnm-positive S. mutans in the saliva by PCR and collagen binding activity, CMBs, and cognitive function were evaluated. Cnm-positive S. mutans was detected more often among subjects with CMBs (p < 0.01) than those without. The risk of CMBs was significantly higher (odds ratio = 14.3) in the group with S. mutans expressing collagen binding activity, as compared to the group without that finding. Deep CMBs were more frequent (67%) and cognitive function was lower among subjects with cnm-positive S. mutans expressing collagen binding activity. This work supports the role of oral health in stroke and dementia and proposes a molecular mechanism for the interaction.

No abstract

BackgroundHelicobacter pylori (H. pylori) colonize the stomach and are considered an etiological agent of gastric cancer. The oral cavity is a transmission route to the stomach, but the exact site of colonization has not yet been explicated. Our study investigated the association between H. pylori infection and presence in oral samples.MethodsDental pulp, supragingival plaque, and saliva from 192 patients visiting the Dentistry’s outpatient clinic were collected for testing. The H. pylori ureA gene was identified via Nested PCR. Urine anti-H. pylori antibody test was utilized to detect infection.ResultsTwenty-five subjects were found to be antibody-positive. PCR analysis of dental pulp revealed that 23 subjects possessed the ureA gene. Twenty-one subjects were positive for both antibodies and genes in dental pulp. PCR testing revealed that 2 subjects were positive in dental plaque but negative for saliva. The subjects positive for H. pylori in dental pulp expressed clinical signs of severe dental caries.ConclusionsH. pylori infected subjects expressed H. pylori in samples from the oral cavity. The main reservoir for infection within the oral cavity was determined to be dental pulp. Moreover, H. pylori are likely transmitted from dental caries to the root canal.

Aim: Stroke is associated closely with vascular homeostasis, and several complex processes and interacting pathways, which involve various genetic and environmental factors, contribute to the risk of stroke. Although adrenomedullin (ADM) has a number of physiological and vasoprotective functions, there are few studies of the ADM receptor system in humans. The ADM receptor comprises a calcitonin-receptor-like receptor (CLR) and receptor activity-modifying proteins (RAMPs). We analyzed single nucleotide polymorphisms (SNPs) in the RAMP2 and CLR genes to determine their association with stroke in the light of gene-environment interactions.Methods: Using cross-sectional data from the Japan Multi-Institutional Collaborative Cohort Study in the baseline surveys, 14,087 participants from 12 research areas were genotyped. We conducted a hypothesis-based association between stroke prevalence and SNPs in the RAMP2 and CLR genes based on data abstracted from two SNPs in RAMP2 and 369 SNPs in CLR. We selected five SNPs from among the CLR variants (rs77035639, rs3815524, rs75380157, rs574603859, and rs147565266) and one RAMP2 SNP (rs753152), which were associated with stroke, for analysis.Results: Five of the SNPs (rs77035639, rs3815524, rs75380157, rs147565266, and rs753152) showed no significant association with obesity, ischemic heart disease, hypertension, dyslipidemia, and diabetes. In the logistic regression analysis, rs574603859 had a lower odds ratio (0.238; 95% confidence interval, 0.076–0.745, adjusted for age, sex, and research area) and the other SNPs had higher odds ratios for association with stroke.Conclusions: This was the first study to investigate the relationships between ADM receptor genes (RAMP2 and CLR) and stroke in the light of gene-environment interactions in human.

This cross-sectional study investigated the relationship between self-reported chewing status and glycemic control in 30,938 Japanese adults who participated in health checkups. Chewing status was evaluated using a self-reported questionnaire. We defined high hemoglobin A1c (HbA1c) levels as a HbA1c level ≥6.5%; 692 (2.2%) respondents met this criterion. After adjusting for gender, age, smoking status, exercise habits, body mass index and eating speed, high HbA1c levels was found to be associated with male gender (odds ratio (OR), 1.568; 95% confidence interval (CI), 1.310 to 1.878; p < 0.001), older age (OR, 1.077; 95% CI, 1.068 to 1.087; p < 0.001), higher body mass index (OR, 1.246; 95% CI, 1.225 to 1.268; p < 0.001), current smoker status (OR, 1.566; 95% CI, 1.303 to 1.882; p < 0.001) and chewing difficulty (OR, 1.302; 95% CI, 1.065 to 1.591; p < 0.05). In conclusion, self-reported chewing difficulty was associated with high HbA1c levels in Japanese adults.