Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon.

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst) eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

Association between parental occupations, educational levels, and household income and children's psychological adjustment in Japan.

OBJECTIVES: Most research on the association between parental or family socio-economic status and psychological adjustment in children has been performed mainly in Western countries, while there is limited evidence of such research in Asian countries. We examined the association of parental occupation and educational levels and household income with children's psychological adjustment in Japan. STUDY DESIGN: This was a cross-sectional study. METHODS: Study subjects were 6329 children aged 3 years. Children's psychological adjustment was assessed using the Strengths and Difficulties Questionnaire. RESULTS: Compared with having an unemployed father, having a father who worked in an administrative and managerial or clerical job was associated with a lower prevalence of peer problems. Compared with having an unemployed mother, having a mother who worked in the professional and engineering, sales, service, or manufacturing process area was associated with a lower prevalence of low prosocial behaviors, whereas having a mother who worked in the clerical, service, or manufacturing process area was associated with an increased prevalence of emotional problems. Having a mother who worked in a clerical area was associated with a higher prevalence of conduct problems. Higher paternal and maternal educational levels were inversely associated with the prevalence of conduct problems and hyperactivity but were positively associated with low prosocial behaviors. A higher household income was inversely associated with the prevalence of emotional problems, conduct problems, and hyperactivity. CONCLUSION: Parental occupation, educational levels, and household income may affect children's psychological adjustment in Japan.

Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays.

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kß x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

Perinatal smoking exposure and risk of asthma in the first three years of life: A prospective prebirth cohort study.

BACKGROUND: There is limited evidence on the association between prenatal smoking exposure and the risk of asthma in children. The aim of this prebirth cohort study was to investigate the association between prenatal and postnatal tobacco smoke exposure and the risk of asthma in Japanese children. METHODS: Study subjects were 1304 mother-child pairs. Information on the variables under study was obtained using repeated questionnaires that were completed by mothers, first prior to delivery, then shortly after birth and subsequently around 4, 12, 24, and 36 months after delivery. Ever asthma was defined as a maternal report of physician-diagnosed asthma at any time since birth. Current asthma was defined as the use of asthma medication at the time of the sixth survey. RESULTS: Logistic regression models revealed that maternal active smoking, either before pregnancy or during pregnancy, was not associated with the risk of ever asthma or current asthma. Further, no association was observed between postnatally living with at least one household smoker and the risk of asthma. Among children whose mothers are never smokers, maternal second-hand smoke (SHS) exposure at work and/or at home during pregnancy increased the risk of ever asthma and current asthma in children; adjusted odds ratio (95% confidence intervals) for ever asthma and current asthma were 2.41 (1.13-5.05) and 4.82 (1.68-13.43), respectively. CONCLUSIONS: Our findings suggest that maternal SHS exposure during pregnancy might be associated with an increased risk of ever asthma and current asthma in young children whose mothers have never smoked.

Preterm birth is associated with higher prevalence of wheeze and asthma in a selected population of Japanese children aged three years.

BACKGROUND: The present cross-sectional study investigated the associations between low birthweight (LBW), high birthweight, preterm birth (PTB), postterm birth, small for gestational age (SGA), and large for gestational age (LGA) and the prevalence of wheeze and asthma in Japanese children aged three years (age range, 33-54 months; mean age, 38.7 months). METHODS: Study subjects were 6364 children. A questionnaire was used to collect all data. Wheeze and asthma were defined according to the criteria of the International Study of Asthma and Allergies in Childhood. RESULTS: The prevalence values of wheeze and asthma were 19.5% and 7.7%, respectively. Of the 6364 subjects, 8.8% were classified as LBW (<2500g), 90.4% as normal birthweight, 0.8% as high birthweight (≥4000g), 4.8% as PTB (<37 weeks), 94.8% as term birth, 0.4% as postterm birth (≥42 weeks), 7.8% as SGA (<10th percentile), 82.5% as appropriate for gestational age, and 9.7% as LGA (>90th percentile). Compared with term birth, PTB was independently positively associated with wheeze and asthma: the adjusted ORs (95% CI) were 1.47 (1.11-1.92) and 1.52 (1.02-2.20), respectively. An independent positive association was shown between PTB and wheeze only in boys; the interaction between PTB and sex was significant. Such an interaction between PTB and sex was not seen for asthma. No evident associations were observed between LBW, high birthweight, postterm birth, SGA, or LGA and wheeze or asthma. CONCLUSIONS: This is the first study in Japan to show that PTB, but not LBW or SGA, was significantly positively associated with childhood wheeze and asthma.

Association of salivary lactate dehydrogenase level with systemic inflammation in a Japanese population.

BACKGROUND AND OBJECTIVE: Salivary lactate dehydrogenase (LDH) was reported to be a useful parameter for the screening of periodontal disease. We performed a cross-sectional study to verify the usefulness of salivary LDH as a biomarker of periodontitis and to investigate the association of severity of periodontitis with systemic inflammation by measuring salivary LDH and serum high sensitive C-reactive protein (hs-CRP) levels in a community-based middle-aged and elderly population in Japan. MATERIAL AND METHODS: We recruited 644 men and 1171 women, aged 30-79 years, who participated in the Toon Health Study during 2011-15. Periodontal condition was assessed by full-mouth examination including mean value of probing depth, percentage of probing depth of ≥4 mm and ≥6 mm, and bleeding on probing. Saliva and blood serum samples were collected for measurement of salivary LDH level and hs-CRP, respectively. A linear trend across quartiles of salivary LDH was calculated using linear regression. Interaction of salivary LDH and overweight status (body mass index of ≥25 kg/m2 ) was tested using the cross-product term of log-transformed continuous salivary LDH and overweight status. RESULTS: Analysis of covariance adjusted for potential confounders revealed strong associations between salivary LDH level and the indicators of periodontal condition (P < .01) in both men and women. Sex- and age-adjusted mean values of hs-CRP according to salivary LDH quartiles were 0.40, 0.45, 0.45 and 0.50 mg/L (P for trend <.01). Although the association was attenuated after further adjustment for body mass index, hypertension, diabetes mellitus, dyslipidemia, alcohol intake, smoking status and physical activity. When stratified by overweight status, the association remained significant in overweight individuals (P = .03). The multivariable adjusted odds ratio of hs-CRP level of ≥1 mg/L for the highest vs lowest quartile of salivary LDH was 1.93 (95% CI, 1.01-3.69) in overweight individuals, but not significant in non-overweight individuals. CONCLUSION: Salivary LDH appears to be a promising biomarker for the mass screening of periodontitis in local community health settings. High salivary LDH levels, particularly in overweight individuals might contribute to prevention of cardiovascular disease, through measuring systemic inflammatory burdens as well as traditional cardiovascular risk factors.

High birthweight is associated with increased prevalence of dental caries in Japanese children.

OBJECTIVE: We determined the prevalence of dental caries in 3-year-old Japanese children in a cross-sectional study and analysed its associations with birthweight, gestational age and birthweight for gestational age among the study subjects. METHODS: Study subjects were 6327 children. Their parents or guardians completed our study questionnaire with information on birth conditions and oral examinations taken from their Maternal and Child Health Handbooks, as documented by medical personnel at the hospital, clinic or public health centre. Children with one or more primary teeth that had either decayed or been filled were categorized as having caries. RESULTS: The prevalence of dental caries was 14.7%. We found a significant association between high birthweight (≥4000 g) and a higher prevalence of caries, compared with normal birthweight (2500-3999 g). Low birthweight (<2500 g) was not associated with dental caries prevalence. In addition, no measurable associations between gestational age or birthweight for gestational age and caries prevalence were observed. CONCLUSIONS: Our findings indicate that high birthweight might increase the likelihood of dental caries in children.

Pathogenic factors in Candida biofilm-related infectious diseases.

Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.

Evaluation of the effectiveness of the potent bis-quaternary ammonium compound, 4,4'-(α,ω-hexametylenedithio) bis (1-octylpyridinium bromide) (4DTBP-6,8) on Pseudomonas aeruginosa.

AIMS: Quaternary ammonium compounds (QACs), including benzalkonium chloride (BAC) and cetylpyridinium chloride (CPC) are cationic surfactants and have been used widely as general disinfectants in the medical field due to their strong antibacterial effects and low cytotoxicity to human cells. 4,4'-(α,ω-hexametylenedithio) bis (1-octylpyridinium bromide) (4DTBP-6,8) is one of the potent bis-QACs synthesized to improve the antimicrobial activities of mono-QACs such as BAC. This study aimed to assess the effectiveness of 4DTBP-6,8 against Pseudomonas aeruginosa, a prevalent hospital pathogen. METHODS AND RESULTS: The minimum inhibitory concentrations of 4DTBP-6,8, CPC and BAC against P. aeruginosa were measured. 4DTBP-6,8 exhibited strong antibacterial activity. We assessed the bactericidal effects of QACs against P. aeruginosa under certain conditions and their cytotoxicities in human epithelial cells using lactate dehydrogenase (LDH) release. 4DTBP-6,8 exerted excellent bactericidal effects against high concentrations of bacteria, biofilm cells and even in the presence of contaminated proteins. Cellular LDH was not released by the treatment with 4DTBP-6,8. CONCLUSIONS: 4DTBP-6,8 exhibited the strongest bactericidal activity against P. aeruginosa among the three QACs tested without any cytotoxicity. SIGNIFICANCE AND IMPACT OF THE STUDY: The potent bis-QAC, 4DTBP-6,8 has the potential to be an effective disinfectant in preventing hospital infections caused by P. aeruginosa.

Relationship between the length of the forefoot bones and performance in male sprinters.

Although recent studies have reported that the forefoot bones are longer in sprinters than in non-sprinters, these reports included a relatively small number of subjects. Moreover, while computer simulation suggested that longer forefoot bones may contribute to higher sprint performance by enhancing plantar flexor moment during sprinting, the correlation between forefoot bone length and sprint performance in humans has not been confirmed in observational studies. Thus, using a relatively large sample, we compared the length of the forefoot bones between sprinters and non-sprinters. We also examined the relationship between forefoot bone length and performance in sprinters. The length of forefoot bones of the big and second toes in 36 well-trained male sprinters and 36 male non-sprinters was measured using magnetic resonance imaging. The length of forefoot bones in the big and second toes was significantly longer in sprinters than in non-sprinters. After dividing the sprinters into faster and slower groups according to their personal best time in the 100-m sprint, it was found that the forefoot bone length of the second toe, but not that of the big toe, was significantly longer in faster group than in slower group. Furthermore, the forefoot bone length of the second toe correlated significantly with the personal best time in the 100-m sprint. This study supported evidence that the forefoot bones are longer in sprinters than in non-sprinters. In addition, this is the first study to show that longer forefoot bones may be advantageous for achieving superior sprint performance in humans.

Novel reuterin-related compounds suppress odour by periodontopathic bacteria.

OBJECTIVE: Halitosis is caused by volatile sulphur compounds including methyl mercaptan (CH3 SH) in the oral cavity and is a serious problem that limits interpersonal social communication. The aim of study was to evaluate the effects of reuterin-related compounds (RRCs) on halitosis-related periodontopathic bacteria in vitro. MATERIALS AND METHODS: RRC-01, RRC-02 and RRC-03 (32 and 64 µg ml-1 ) in culture media containing Fusobacterium nucleatum JCM8523 and Porphyromonas gingivalis ATCC33277 were used. The effects of RRCs on CH3 SH production and detectable odour by F. nucleatum and P. gingivalis were examined by CH3 SH production assay and organoleptic test, respectively. The number of bacterial cells was also measured using an ATP assay. In P. gingivalis treated with RRCs, the expression of mgl gene, which is responsible for CH3 SH production, was examined by qRT-PCR. RESULTS: CH3 SH production and the score of detectable odour from F. nucleatum and P. gingivalis culture media containing RRCs were significantly lower than that without RRCs (P < 0.05). The expression of mgl gene in P. gingivalis was significantly downregulated by RRC-01 (P < 0.01), but not by RRC-02 or RRC-03. CONCLUSIONS: RRCs are potent oral care products for preventing halitosis via reducing CH3 SH production.

Intake of dairy products and calcium and prevalence of depressive symptoms during pregnancy in Japan: a cross-sectional study.

OBJECTIVE: To examine the relationship between the intake of dairy products and calcium and the prevalence of depressive symptoms during pregnancy. DESIGN: Cross-sectional study. SETTING: Kyushu Okinawa Maternal and Child Health Study (KOMCHS). SAMPLE: A cohort of 1745 pregnant Japanese women. METHODS: Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Scores of 16 or higher on the Center for Epidemiologic Studies Depression Scale denoted depressive symptoms. Adjustment was made for age, gestation, region of residence, number of children, family structure, history of depression, family history of depression, smoking, secondhand smoke exposure at home and at work, job type, household income, education, and body mass index. In our analyses regarding dairy products in general, adjustment was also made for fish intake; in our analysis regarding calcium, adjustment was also made for the intake of saturated fatty acids, eicosapentaenoic acid plus docosahexaenoic acid, and vitamin D. MAIN OUTCOME MEASURES: Depressive symptoms during pregnancy. RESULTS: Higher intake levels of yogurt and calcium were independently related to a lower prevalence of depressive symptoms during pregnancy: the adjusted odds ratios between extreme quartiles were 0.69 (95% CI 0.48-0.99, P for trend = 0.03) and 0.59 (95% CI 0.40-0.88, P for trend = 0.006), respectively. No relationships were observed between the intake of all dairy products, milk, or cheese and depressive symptoms during pregnancy. CONCLUSIONS: The current results suggest that a higher intake of yogurt and calcium may be associated with a lower prevalence of depressive symptoms during pregnancy.

IL5RA polymorphisms, smoking and eczema in Japanese women: the Kyushu Okinawa Maternal and Child Health Study.

The present case-control study examined the relationship between IL5RA SNPs and eczema in young adult Japanese women. Cases and control subjects were selected from pregnant women who participated in the baseline survey of the Kyushu Okinawa Maternal and Child Health Study, which is an ongoing prebirth cohort study. Cases comprised 188 women with eczema in the previous 12 months as defined according to the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC), regardless of the presence of a doctor's diagnosis of atopic eczema. Control subjects comprised 1130 women without eczema as defined according to the ISAAC criteria who also had not been diagnosed with atopic eczema by a doctor. Compared with the AA genotype of IL5RA SNP rs17881144, the AT genotype, but not the TT genotype, was significantly associated with a decreased risk of eczema. The ATTAGA haplotype and the GTAGCA haplotype of rs17882210, rs3804797, rs334809, rs9831572, rs6771148 and rs17881144 were significantly associated with an increased risk of eczema. In contrast, the GCTGCA haplotype was significantly related to a decreased risk of eczema. Multiplicative interactions between IL5RA SNPs rs334809 and rs17881144 and smoking with respect to eczema were marginally significant (P = 0.07 and 0.07, respectively). This is the first study to show significant associations between IL5RA SNP rs17881144, the ATTAGA haplotype, the GTAGCA haplotype, and the GCTGCA haplotype and eczema. Smoking may modify the relationships between SNPs rs334809 and rs17881144 and eczema.

Treatment of pressure ulcers in patients with declining renal function using arginine, glutamine and ß-hydroxy-ß-methylbutyrate.

The aim of this study is to examine the efficacy on healing pressure ulcers (PU) of using a supplement combination containing arginine, glutamine and ß-hydroxy-ß-methylbutyrate, which was given to two elderly patients with renal dysfunction. The PU was surgically opened, decompressed and treated by drugs. A half quantity of the defined dose of the supplement combination, with an enteral nutrition product, was administered to the patients twice a day. This combination improved the PUs, with no effect on renal function. This novel finding may provide a nutritional rationale of arginine, glutamine and ß-hydroxy-ß-methylbutyrate for PUs associated with renal dysfunction.

IL3 rs40401 polymorphism and interaction with smoking in risk of asthma in Japanese women: the Kyushu Okinawa Maternal and Child Health study.

Three previous genetic association studies conducted in Korea and China investigated the relationship between IL3 single nucleotide polymorphism (SNP) rs40401 and asthma, but their results were inconsistent. We examined this relationship and the possibility of an interaction between IL3 SNP rs40401 and smoking in young adult Japanese women. Included were 89 women who met the criteria of the European Community Respiratory Health Survey (ECRHS) for asthma. Control subjects were 700 women without asthma according to the ECRHS criteria who had not been diagnosed with asthma and/or allergic rhinitis by a doctor and/or who had not met the criteria of the International Study of Asthma and Allergies in Childhood for rhinoconjunctivitis. A significant positive association was found between SNP rs40401 and the risk of asthma, with the TT genotype as the reference under the additive model: the adjusted odds ratio was 1.39 (95% CI: 1.004-1.93). The positive association was not statistically significant in any other genetic model. Compared with subjects with the TT or TC genotype of SNP rs40401 who had never smoked, those with the CC genotype who had ever smoked had a significantly increased risk of asthma: the adjusted OR was 2.67 (95% CI: 1.23-5.79); the additive interaction, but not the multiplicative interaction, was significant. This study suggests that IL3 SNP rs40401 is significantly associated with the risk of asthma in young adult Japanese women and reveals that the combination of ever smoking and having the CC genotype of IL3 SNP rs40401 is significantly positively associated with asthma.

Effects of extracellular DNA from Candida albicans and pneumonia-related pathogens on Candida biofilm formation and hyphal transformation.

AIMS: The aim of this study was to investigate the effects of genomic DNA purified from Candida albicans and pneumonia-related pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, on in vitro biofilm formation and morphological change of 3 Candida species (C. albicans, C. glabrata, and C. tropicalis). METHODS AND RESULTS: Biofilm formation was evaluated by the crystal violet assay and colony-forming unit counts. Morphological characteristics of biofilms were evaluated by scanning electron microscopy and fluorescence microscopy. Addition of DNA at a low concentration (<1·0 µg ml(-1)) significantly increased biofilm mass of all three Candida species. In contrast, the addition of DNA at a high concentration (10 µg ml(-1)) decreased the biofilm mass. Interestingly, the formation of hyphae in a dense network of yeast cells was observed in C. albicans biofilms exposed to a low concentration of DNA (<1·0 µg ml(-1)). CONCLUSIONS: These findings demonstrated that extracellular DNA (eDNA) plays a crucial role in Candida biofilm formation and suggested that eDNA may induce the morphological transition from yeast to hyphal growth form during C. albicans biofilm development. SIGNIFICANCE AND IMPACT OF THE STUDY: A novel therapy targeting eDNA may be applicable for Candida infection to decrease biofilm formation and hyphal formation.

Pro-angiogenic cytokines for prediction of outcomes in patients with advanced hepatocellular carcinoma.

BACKGROUND: We previously reported that expressions of the pro-angiogenic cytokines angiopoietin-2 (Ang-2), follistatin, granulocyte colony-stimulating factor, hepatocyte growth factor, leptin, platelet-derived growth factor-BB, platelet endothelial cell adhesion molecule-1, and vascular endothelial growth factor were associated with the response to sorafenib in patients with advanced hepatocellular carcinoma (HCC). The aim of the present study is to examine the same relationship in a larger cohort. METHODS: In the current retrospective cohort study, we measured serum levels of the eight cytokines in 120 consecutive HCC patients who were treated with sorafenib. We evaluated the effects of increased expression of serum cytokines on progression-free survival (PFS) and overall survival (OS). RESULTS: Elevated expression of Ang-2 correlated both with significantly shorter PFS (hazard ratio (HR), 1.84; 95% confidence interval (CI), 1.21-2.81), and OS (HR, 1.95; 95% CI, 1.21-3.17). Patients with more than three cytokines expressed above the median similarly had significantly shorter PFS (HR, 1.98; 95% CI, 1.30-3.06) and OS (HR, 1.94; 95% CI, 1.19-3.22). Differences in OS were evident in cases with the evidence of macroscopic vascular invasion or extrahepatic metastasis. CONCLUSION: High expression of Ang-2 or more than cytokines in serum is associated with poor PFS and OS in HCC patients treated with sorafenib.

Case-control study of eczema in relation to IL4Rα genetic polymorphisms in Japanese women: The Kyushu Okinawa Maternal and Child Health Study.

Epidemiological research on the relationship between single nucleotide polymorphisms (SNPs) in the IL4Rα gene and eczema is sparse. We investigated the associations between IL4Rα SNPs rs1805011, rs1805015 and rs1801275 and risk of eczema in young adult Japanese women. Included were 188 women who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for eczema. Controls were 635 women without eczema according to the ISAAC criteria who also had not been diagnosed with asthma, atopic eczema and/or allergic rhinitis by a doctor. Adjustment was made for age, region of residence, number of children, smoking and education. Under the additive model, SNP rs1805011 was significantly related to eczema: the adjusted OR was 0.55 (95% CI: 0.31-0.99). SNP rs1805015 was significantly associated with eczema in the additive and dominant models: the adjusted ORs were 0.55 (95% CI: 0.30-0.98) and 0.55 (95% CI: 0.30-0.997), respectively. There was no significant association between SNP rs1801275 and eczema. None of the haplotypes were significantly related to eczema. Significant associations between SNPs rs1805011 and rs1805015 and eczema were reported in women who had never smoked, but not in those who had ever smoked; the multiplicative interactions, however, were not significant. This is the first study to demonstrate significant associations between IL4Rα SNPs rs1805011 and rs1805015 and eczema. We do not find evidence for interactions affecting eczema between IL4Rα SNPs and smoking.

VDR gene polymorphisms, interaction with smoking and risk of periodontal disease in Japanese women: the Kyushu Okinawa maternal and child health study.

Epidemiological evidence on the relationship between vitamin D receptor (VDR) polymorphisms and periodontal disease is inconsistent. We investigated associations between four VDR single-nucleotide polymorphisms (SNPs) including rs731236 (TaqI), rs7975232 (ApaI), rs1544410 (BsmI) and rs2228570 (FokI), and the risk of periodontal disease among young Japanese women. Cases included 131 women who had at least one tooth with a probing depth of 3.5 mm or deeper. Controls included 1019 women without periodontal disease. Adjustment was made for age, region of residence, education, toothbrushing frequency and use of an interdental brush. Compared with the AA genotype of SNP rs731236, the GG genotype had a significantly increased risk of periodontal disease: the adjusted OR was 3.68 (95% confidence interval: 1.06-12.78). There were no significant relationships between SNPs rs7975232, rs1544410 or rs2228570 and periodontal disease. None of the haplotypes were significantly related to periodontal disease. Compared with subjects with the AA or AG genotype of SNP rs731236 who had never smoked, those with the GG genotype who had ever smoked had a significantly increased risk of periodontal disease; nevertheless, neither multiplicative nor additive interaction was significant. The additive interaction between SNP rs7975232 and smoking was significant, although the multiplicative interaction was not statistically significant. No multiplicative or additive interactions were observed between the other SNPs and smoking. Our results indicated that VDR SNP rs731236 might be associated with periodontal disease. In addition, we present new evidence for a biological interaction between VDR SNP rs7975232 and smoking that affects periodontal disease.

Active and passive smoking and prevalence of periodontal disease in young Japanese women.

BACKGROUND AND OBJECTIVE: Studies reporting on the association between smoking and periodontal disease have mostly focused on active smoking. The purpose of this study was to examine the relationships between active smoking and exposure to second-hand smoke at home and at work and the prevalence of periodontal disease among young Japanese women. MATERIAL AND METHODS: Study subjects were 1167 postpartum women with a mean age of 31.5 years. Information on smoking and potential confounding factors was obtained through a self-administered questionnaire. Partial-mouth recording was used to determine probing pocket depth at six sites per tooth for six teeth in the mouth. Periodontal disease was defined as positive if a woman had at least one tooth with a probing pocket depth of 3.5 mm or deeper. Adjustment was made for age, region of residence, household income, education, toothbrushing frequency and use of an interdental brush. RESULTS: Compared with never smoking, ever smoking was independently positively associated with the prevalence of periodontal disease: the adjusted odds ratio was 1.56 (95% confidence interval: 1.02-2.36). There was a marginally significant positive dose-response relationship between pack-years of smoking and the prevalence of periodontal disease (p for linear trend = 0.08). No material associations were observed between second-hand smoke exposure at home or at work and periodontal disease. CONCLUSION: Our findings suggest that active smoking, but not passive smoking, might be associated with an increased prevalence of periodontal disease among young women in Japan.