Oral Cnm-positive Streptococcus Mutans Expressing Collagen Binding Activity is a Risk Factor for Cerebral Microbleeds and Cognitive Impairment.

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.

Validity of self-reported number of teeth and oral health variables.

BACKGROUND: Oral condition and number of teeth were investigated by questionnaire in the Japan Multi-Institutional Collaborative Cohort (J-MICC Study). The aim of the present study was to assess the validity of the tooth number measure by comparing the self-reported number of teeth with the number of teeth determined at clinical dental examination. METHODS: A self-administered questionnaire and dental examination were performed by 1275 participants of a company medical examination who requested dental check-up and 377 subjects of the J-MICC study. The validity of the tooth number measure was assessed by comparing the self-reported number of teeth with that determined at clinical examination. Spearman's rank correlation coefficient was calculated to quantitatively evaluate the validity. RESULTS: In males, the mean clinically-examined and self-reported numbers of teeth were 26.5 and 24.8 teeth, respectively. In females, the mean clinically-examined and self-reported numbers of teeth were 26.4 and 25.5 teeth, respectively. There was a tendency toward underestimation of the number of natural teeth by self-reporting. A significant correlation was observed between the clinically-examined and self-reported numbers of teeth in total (ρ = 0.69) and both males (ρ = 0.70) and females (ρ = 0.67). CONCLUSIONS: The self-reported oral health variables were valid and reflected clinical status. Further revision of the question on the remaining tooth in the questionnaire improves the validity of self-reported number of teeth.

ß-cryptoxanthin regulates bone resorption related-cytokine production in human periodontal ligament cells.

OBJECTIVE: ß-cryptoxanthin (ß-cry) is a type of carotenoid found in certain fruits and vegetables. Although it has been shown that ß-cry inhibits alveolar bone resorption, the molecular mechanisms for this have not yet been clarified. In the present study, we investigated the effects of ß-cry on bone resorption related-cytokine production in human periodontal ligament (hPDL) cells. DESIGN: hPDL cells were stimulated with ß-cry (1×10(-7)mol/l), mechanical stress (1 or 6MPa), and P. gingivalis. The production of interleukin (IL)-1ß, IL-6, IL-8, tumour necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by RT-PCR and ELISA. RESULTS: The production of IL-1ß, IL-6, IL-8, and TNF-α was not induced in hPDL cells after stimulation with ß-cry, although these cytokines were produced after stimulation with P. gingivalis. On the other hand, IL-6 and IL-8 were produced after exposure to 6MPa of mechanical stress. The production of IL-6 and IL-8 was significantly decreased by the addition of ß-cry. Furthermore, ß-cry up-regulated the production of OPG, but not RANKL. CONCLUSION: ß-cry inhibited the production of IL-6 and IL-8 induced by mechanical stress and periodontopathogenic bacteria in hPDL cells. Moreover, ß-cry up-regulated OPG production. These results suggest that ß-cry may prevent bone resorption in periodontitis.

valsartan in elderly isolated systolic hypertension (VALISH) study: rationale and design.

Although antihypertensive therapy has been proven to reduce cardiovascular morbidity and mortality, it is unclear how much blood pressure should be decreased in elderly patients with hypertension. The Valsartan in Elderly Isolated Systolic Hypertension (VALISH) study is a multicenter parallel-group study comparing the incidence of cardiovascular events between two target systolic blood pressure levels, below 140 mmHg and below 150 mmHg, under treatment with valsartan, an angiotensin II receptor blocker, as an initial antihypertensive drug in elderly patients with isolated systolic hypertension. The number of patients to be recruited is 3,000 and the duration of follow-up is at least 2 years. This 3,000-patient trial was designed with a two-sided alpha level of 0.05 and 80% power to detect the difference in incidence of cardiovascular events between the target blood pressure levels based on estimation of the cardiovascular events ratio as 21.5/1,000 patient-years and 29.1/1,000 patient-years for the two blood pressure levels. The VALISH study, a large-scale investigator-initiated trial in Japan, will determine whether age should be considered in setting target blood pressure in treatment of isolated systolic hypertension in elderly patients.