Estimation of the effective reproduction number of influenza based on weekly reports in Miyazaki Prefecture.

In Japan, as part of surveillance for seasonal influenza, the number of patients per influenza sentinel site is counted on a weekly basis. Currently, reference values are set for the weekly reported number of influenza cases per sentinel, and pre-epidemic and epidemic warnings are issued based on these values. In this study, we examined the association between these reference values and the effective reproduction number (Rt) using surveillance data for Miyazaki Prefecture collected from 2010 to 2011. There are nine public health centre jurisdictions in this prefecture, and Rt exceeded 1.0 at the time when pre-epidemic warnings were issued in almost all the jurisdictions. Thus, it was indicated that the validity of the reference value was also high for influenza transmission. However, our results indicated the presence of secondary epidemic caused by infections originating both from other jurisdictions and inner jurisdictions, and it is occasionally not possible to evaluate the end of an epidemic in a jurisdiction using only the reference value of termination. It is necessary to establish new methods after considering the situation in the surrounding jurisdictions for more detailed epidemic predictions.

Prognostic Value of Left Atrial Size and Functional Indices Measured by 3-Dimensional Speckle-Tracking Analysis.

BACKGROUND: The prognostic value of indices for left atrial volumes (LAV) and reservoir function measured by 3D speckle-tracking analysis (3DSTA) has not been determined. Methods and Results: LA maximal and minimal volume indices (LAVImax, LAVImin), and LA emptying fraction (LAEmpF) were measured via 2D echocardiography (2DE) and 3DSTA in 514 patients (62% male, mean age: 66±15 years) with various cardiovascular diseases. Two cutoff values using normal±2SD (cutoff criterion 1) and receiver-operating characteristic analysis (cutoff criterion 2) were evaluated. During a mean follow-up of 720±383 days, MACE (cardiac death, nonfatal myocardial infarction, stroke and admission for heart failure) occurred in 98 patients. Kaplan-Meier survival analysis showed both cutoff criteria measured by 2DE and 3DSTA had significant predictive power for MACE (P<0.001). For cutoff criterion 1, 3DSTA measurements yielded higher hazard ratios than 2DE by Cox proportional hazard model. Cutoff criterion 2 using 3DSTA had higher average treatment effect values than 2DE by matching propensity scores on the outcome. Further, a regression model that included clinical variables, left ventricular ejection fraction and cutoff criterion 2 using 3DSTA-derived LAEmpF had significantly higher prognostic power than 2DE. CONCLUSIONS: LA indices measured by 3DSTA had greater prognostic power for future MACE than 2DE. In particular, 3DSTA-derived LAEmpF has the potential to be a valuable prognostic tool in clinical settings.

Assessing the chronic respiratory health risk associated with inhalation exposure to powdered toner for printing in actual working conditions: a cohort study on occupationally exposed workers over 10 years.

BACKGROUND: Little epidemiological evidence exists regarding the chronic respiratory effects of inhaled powdered toner exposure in humans, although several case reports have suggested the existence of lung disorders that might be related to exposure to toner dust. OBJECTIVE: We aimed to estimate the chronic health risk to humans associated with routine toner dust exposure in copier industry workers under current actual work conditions. DESIGN: A prospective observational cohort study of occupational population. METHODS: Changes in chest radiogram, spirometry measurements and serum and urine biomarkers of biomedical responses to extrinsic stress, as well as subjective symptoms were longitudinally observed for up to 10 years in Japanese copier industry workers responsible for the manufacturing, maintenance or recycling of powdered toner or toner-using machines. A total of 694 subjects who did not change their work category during the follow-up and were free from chronic respiratory diseases at the baseline survey provided reliable results on at least three survey occasions during 3 years or more of follow-up. RESULTS: Typical fibrosis findings associated with pneumoconiosis was not observed on chest radiograms. No significant differences associated with toner exposure were noted in the frequency of new incidence of either non-specific findings on chest radiogram or serum fibrosis biomarkers (sialylated carbohydrate antigen KL-6 and surfactant protein D). However, the exposed subjects tended to show increases in the frequency of respiratory symptoms and reduced spirometry results during the follow-up compared with the control group, although significant differences were only seen in chronic cough. CONCLUSIONS: Under the current reasonably controlled work environmental conditions, lung fibrotic changes caused by inhaled dust exposure, including powdered toner, appear to be relatively uncommon; however, non-specific temporal irritation causing subjective symptoms and inflammatory responses might exist.

Clinical impact of undersized- versus oversized-stenting approaches in ST-elevation myocardial infarction.

BACKGROUND: Primary percutaneous coronary intervention (PCI) is the standard treatment in patients with ST-elevation myocardial infarction (STEMI). However, some patients still develop ST re-elevation during PCI, resulting in further myocardial damage and a poor outcome. An undersized-stenting approach may prevent ST re-elevation. We aimed to determine the association between final stent area and ST re-elevation during primary PCI for STEMI. METHODS: Overall, 102 consecutive STEMI patients who underwent primary PCI under integrated backscatter intravascular ultrasound guidance were enrolled. The stent-reference (SR) ratio was defined as the stent cross-sectional area (CSA) divided by the average CSA of the 5-mm proximal and distal reference lumens. The patients were divided into two groups according to the SR ratio: undersize group (SR<1.0, n=62) and oversize group (SR≥1.0, n=40). The incidences of ST re-elevation and total ST resolution (STR) were compared. RESULTS: The oversize group showed a higher incidence of ST re-elevation (32.5 vs. 9.7%, p=0.004) and a lower total STR (22.4±62.7 vs. 43.4±38.6%, p=0.04). After adjustment, the oversized-stenting approach was independently associated with ST re-elevation [odds ratio: 3.74, 95% confidence interval (CI) 1.27-12.1, p=0.02]. The peak creatine kinase-MB level was higher in the oversize group (341±259 vs. 242±208IU/l, p=0.04). The incidences of stent thrombosis and restenosis were similar between the two groups. CONCLUSIONS: An oversized-stenting approach in patients with STEMI was associated with a higher incidence of ST re-elevation and a lower total STR, resulting in increased myocardial damage.

Quantitative effects of a declaration of a state of emergency on foot-and-mouth disease.

OBJECTIVES: The law in Japan requires the declaration of a state of emergency and implementation of countermeasures for an epidemic of a new infectious disease. However, because a state of emergency has never been declared in Japan, its effects remain unknown. The required countermeasures are similar to those implemented in the foot-and-mouth disease epidemic in Miyazaki in 2010. This study aimed to quantitatively estimate the effect of the declaration in 2010 and investigate the nature of the epidemic based on the day on which the declaration took effect. METHODS: Only publicly available data were used. Data for farms in the most affected town were analyzed. A modified susceptible-infected-recovered model was used to estimate the effect and for the simulation. Another model was used to estimate the effective reproduction number. RESULTS: After the declaration, the intra-bovine transmission rate decreased by 18.1 %, and there were few days when the effective reproduction number was >1.0. A few weeks delay in the declaration significantly increased the possibility of epidemic, number of farms at peak, and final infection scale. CONCLUSIONS: Based on the substantial decrease in the transmission rate after the declaration of a state of emergency in 2010, a future declaration will have a similar effect for a new infectious disease even though a direct extrapolation is not valid. Although a declaration should be carefully considered owing to the potential socioeconomic effects, it is essential to prepare for the implementation given that a delay of only a few weeks should be acceptable.

Patterns of Sensitization to Inhalant Allergens in Japanese Lower-Grade Schoolchildren and Related Factors.

OBJECTIVE: This study clarified sensitization patterns to house dust mite (HDM) and Japanese cedar pollen (JCP) in Japanese lower-grade schoolchildren. We also explored factors associated with allergic sensitization. METHODS: This cross-sectional study used a database from the Study on Respiratory Disease and Automobile Exhaust (SORA), a Japanese health study project. The subjects comprised 8,815 pupils aged 6-9 years. We obtained the distribution of HDM- and JCP-specific IgE, respectively, as a marker of sensitization. To determine factors associated with sensitization, we used logistic regression and calculated adjusted odds ratios (AORs) for the relative prevalence of sensitization. The cut-off point for specific IgE levels was 0.35 kU/l. RESULTS: Sensitization to HDM and JCP was detected in 51 and 39% of subjects, respectively, occurring more often in boys and at older ages. In addition, AORs of sensitization to HDM/JCP were higher in subjects with a history of bronchitis, parental asthma, parental atopic eczema and parental pollinosis. In contrast, AORs for sensitization were lower in those subjected to maternal passive smoking as well as among boys with pets. AORs of sensitization to JCP alone were lower in those with a history of otitis media, those who had been bottle milk fed, and those who were not the firstborn and who lived near a busy road. CONCLUSION: Sensitization to HDM and JCP was detected in 51 and 39% of lower-grade schoolchildren, respectively.

Possible production of arsenic hemoglobin adducts via exposure to arsine.

OBJECTIVES: Arsine is an arsenic compound generated as a by-product in metal refineries. Accidental poisoning occurs sporadically; however, the administrative level for workers has not been established. Thus, it is essential to identify a highly specific biomarker for risk management in the workplace. The aim of this study was to identify an arsenic adduct, a potential biomarker, in the plasma. METHODS: Preserved mouse blood was exposed to arsine in vitro, and the plasma was separated. The residual clot of the control sample was hemolyzed using ultrapure water, and the supernatant was collected. Plasma from mice exposed to arsine in vivo was also separated from blood. Immunoprecipitation assays were conducted using all samples after ultrafiltration, and three fractions were collected. The total arsenic concentration in each fraction was quantified using inductively coupled plasma mass spectrometry (ICP-MS). The three in vitro samples and the eluate fraction from immunoprecipitation were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS: In the exposed samples, the arsenic concentration in the fraction containing immunocomplexes was higher when immunoprecipitation was conducted with an anti-globin antibody. Three peaks were specifically observed in arsine-exposed samples after MALDI-TOF-MS analysis. Two of them were around m/z 15,000, and the other was m/z 15,700. The latter peak was confirmed even after immunoprecipitation. CONCLUSIONS: Globin forms an adduct with arsenic after both in vitro and in vivo exposure to arsine. This adduct together with hemoglobinuria could be a candidate biomarker of acute arsine poisoning in plasma.

Association of arteriosclerosis index and oxidative stress markers in school children.

BACKGROUND: Recent years have seen increased numbers of children with conditions that contribute strongly to atherosclerotic disease, such as passive smoking, obesity, and dyslipidemia. In the present study, we evaluated the utility of non-invasive urinary markers in preventing lifestyle-related diseases by comparing lipid metabolism-related parameters with oxidative stress markers in school children. METHODS: Subjects were 85 first-grade students. The variables examined included the smoking in subjects' household; exercise habits; height and weight; blood pressure; and plasma total cholesterol, high-density lipoprotein cholesterol, triglyceride, leptin, blood sugar, urinary cotinine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostaglandin F2α (IsoP). RESULTS: Of the subjects, 10.6% were obese (% overweight ≥ 20%), 3.5% had a high-risk arteriosclerosis index (AI; 3 ≤ AI < 5), and 29.4% were passive smokers. No significant differences were seen between boys and girls for any of the measurement parameters. Both urinary 8-OHdG (6.8-24.5 ng/mg creatinine) and IsoP (0.9-7.4 ng/mg creatinine) were detected in all subjects, and a significant positive correlation was seen between the two markers. On multiple regression analysis using AI as an objective variable and all non-invasive markers as explanatory variables, urinary IsoP correlated most strongly with AI (P ≤ 0.01). CONCLUSIONS: Risk factors for atherosclerosis in adults, such as obesity and hypercholesterolemia, are associated with oxidative stress and inflammation. The present findings of the strongest correlation between urinary IsoP and AI suggest that urinary IsoP may serve as a non-invasive and effective early marker in predicting risk in children of developing lifestyle-related diseases.

Induction of activation-induced cytidine deaminase by a not-directly mutagenic carcinogen: a novel potential molecular mechanism.

OBJECTIVE: The molecular mechanisms underlying the carcinogenic activity of not-directly mutagenic (Ames mutagenicity test-negative) carcinogens are not fully understood. Given recent findings that ectopic expression of activation-induced cytidine deaminase (AID) in somatic cells plays a critical role in carcinogenesis, we investigated whether several of the established not-directly mutagenic carcinogens induce AID expression. METHODS: We prepared cells with stable expression of luciferase reporter gene containing the promoter of AID. We then used this system to examine the AID promoter activity of the non-genotoxic carcinogen: butyl benzyl phthalate, bisphenol A, di (2-ethylhexyl) phthalate, cadmium chloride (Cd), and butylated hydroxyanisole. RESULTS: Results showed that Cd increased the promoter activity of AID and actually induced AID gene expression. CONCLUSION: A not-directly mutagenic carcinogen, cadmium, has the potential to induce the AID gene, suggesting that this might represent a novel molecular mechanism of carcinogenesis of cadmium.

Association between traffic-related air pollution and development of asthma in school children: cohort study in Japan.

Air pollution is widely understood to be capable of exacerbating asthma symptoms. Here we examined the association between traffic-related air pollution and development of asthma in school children. Subjects were 10,069 school children in their first through third years of compulsory education (6-9-year old). The main outcome was incidence of asthma as determined from the questionnaire. Follow-up surveys were conducted every year up to 4 years after the end of the study. To evaluate individual level of exposure to traffic-related air pollution, we used a simulation model that accounted for exposure level both at home and at school. As surrogates of traffic-related air pollution, the estimation target was the annual average individual exposure of automobile exhaust-originating nitrogen oxides (NOx) and elemental carbon (EC). Confounding factors were adjusted using a discrete-time logistic regression model. We found a positive association between exposure to EC and incidence of asthma. The odds ratio (OR) (95% confidence interval) for asthma incidence was 1.07 (1.01-1.14) for each 0.1 µg/m(3) EC and 1.01 (0.99-1.03) for each 1 p.p.b. NOx. Traffic-related air pollution is associated with development of asthma in school children.

Involvement of annexin A8 in the properties of pancreatic cancer.

Although Annexin A8 (ANXA8), a member of a superfamily of calcium and phospholipid binding proteins, is physiologically expressed in a tissue-specific manner, recent microarray studies reported that ANXA8 was also ectopically expressed in pancreatic cancers. We investigated the molecular mechanism of expression of ANXA8 in cancer cells and its functional role in pancreatic cancer cells. ANXA8 was diversely expressed in human cancer cell lines. Expression was enhanced by treatment with 5-aza-dC and butyrate, and correlated with methylation status at CpG in the promoter-exon 1 region. Inhibition of ANXA8 using siRNA in BxPC-3 cells which express ANXA8 at a high level elevated caspase-3 and -7 activities. In in vitro invasion assay, inhibition of ANXA8 using siRNA in BxPC-3 reduced the numbers of migrating cells, and down-regulated HIF-1α mRNA transcription. Overexpression of ANXA8 increased the number of viable cells and BrdU incorporation in PANC-1 cells, which express ANXA8 at a low level. Expression of ANXA8 was induced under conditions of nutrient deprivation, and overexpression of ANXA8 showed resistance against serum starvation in PANC-1 cells. In a promoter assay, co-transfection with the expression vector of ANXA8 and the vector of a reporter gene containing the promoter of HIF-1α enhanced HIF-1α promoter activity. In contrast, this effect of ANXA8 was inhibited by administration of BAPTA-AM, an intracellular Ca²âº chelator. These results suggest that ectopic ANXA8 expression in cancer cells might involve an epigenetic mechanism. ANXA8 might play an important role in calcium fluctuation-mediated HIF-1α transcriptional activation and cell viability.

Urinary 1-hydroxypyrene as a comprehensive carcinogenic biomarker of exposure to polycyclic aromatic hydrocarbons: a cross-sectional study of coke oven workers in China.

PURPOSE: Polycyclic aromatic hydrocarbons (PAHs) are multiple compounds that include many carcinogens. We conducted a cross-sectional study in steel plant workers in Anshan, China, to identify biomarkers that reflect the carcinogenicity of PAHs. METHODS: Subjects were 57 workers and 20 controls. Level of personal exposure to PAHs was measured using GC-MS. In accordance with the assessment methods defined by the United States Environmental Protection Agency (US EPA), 15 PAHs were selected for the analysis. For the measurement of urinary metabolites, urine samples were treated with ß-glucuronidase and analyzed using HPLC with a fluorescence detector. RESULTS: The mean range of personal exposure to 15 PAHs (total PAHs) was 178.85, 47.08-1,329.45 (geometric mean, 5th and 95th percentile) µg/m(3). Ten known urinary metabolites (1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 3-hydroxyphenanthrene, 9-hydroxyphenanthrene, 1-hydroxypyrene, 3-hydroxybenz[a]anthracene, 6-hydroxychrysene, and 3-hydroxybenzo[a]pyrene) and four unknown peaks were detected. The highest correlation was between total PAHs and urinary 2-hydroxynaphthalene (Spearman r = 0.716, P < 0.01). Among the detected urinary metabolites, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 3-hydroxyphenanthrene, and 1-hydroxypyrene were found to correlate significantly with the "Σ carcinogenic potency of PAHs" (sum of seven carcinogenic PAHs calculated from the levels of personal PAHs and relative potency factors), and with the greatest correlation found for 1-hydroxypyrene (Spearman r = 0.630, P < 0.01). CONCLUSIONS: The analysis of personal exposure to 15 PAHs and 10 urinary metabolites, and calculation of Σ carcinogenic potency, indicated that urinary 1-hydroxypyrene was the most comprehensive carcinogenic biomarker of exposure to PAHs.

Symptoms related to glaucomatous visual field abnormalities among male Japanese workers in a population-based setting.

PURPOSE: To identify symptoms potentially related to glaucomatous visual field abnormalities (VFAs) in a population-based setting, and to assess the applicability of using these symptoms to identify persons at risk of developing glaucoma. METHODS: In this study, 10,214 Japanese male general workers (mean age, 45.3±8.8 years) filled out a self-administered questionnaire and underwent frequency doubling technology (FDT) perimetry testing. The questionnaire inquired about whether the participant was suffering from any of nine symptoms, with scores for each response graded on a four-item Likert scale: 0 (none), 1 (rarely), 2 (sometimes), and 3 (always). Results from the questionnaire were compared among three groups: participants without any VFAs (9767), participants with VFAs as determined by the FDT test (FDT-VFA; 447), and 227 participants (of the 447 FDT-VFA participants) with glaucomatous VFAs who were newly diagnosed by ophthalmologic examinations. RESULTS: The mean summed scores for the total items were significantly (p<0.01) higher in FDT- and glaucomatous VFA groups than in normal subjects. In particular, responses citing the symptoms 'feeling of something in the front of the eye' and 'feeling of hardness to see in dark places' were significantly (p<0.05) more frequent in subjects with FDT- and glaucomatous VFAs than among normal participants. However, the respective areas under the receiver operating characteristic curve of summed scores for the nine total items and for the two items which showed significant differences for the glaucoma groups were 0.57 (95% confidence interval=0.53-0.60) and 0.58 (95% confidence interval=0.54-0.61). CONCLUSION: Although the symptoms 'feeling of hardness to see in dark places' and 'feeling of something in the front of the eye' could be associated with glaucomatous VFA in a population-based setting, inquiring about symptoms is of little aid in identifying subjects with glaucomatous VFA as a strategy for public health.

Ectopic expression of activation-induced cytidine deaminase caused by epigenetics modification.

Recently studies have shown that ectopic expression of activation-induced cytidine deaminase (AID) plays an important role in carcinognesis and cancer progression of inflammatory-associated cancers. Here, we examined the molecular mechanism of ectopic expression of AID in cancer cells, and whether or not nitric oxide (NO) modulates this expression, as NO is known to cause chemical deamination of the cytidine. In several cancer cell lines, treatment with the DNA methyltransferase (Dnmt) inhibitor 5-Aza-dC effected expression of AID by TNF-α, and expression was further induced by additional treatment with histone deacetylase (HDAC) inhibitors with no stimulation. The CpG sites located in the promoter and exon 1 region of the AID gene in cancer cells were found to be hypomethylated in correlation with AID expression levels. Further, administration of HDAC inhibitors also induced expression of inducible nitric oxide synthase (iNOS) in cancer cells treated with 5-Aza-dC. Interestingly, administration of S-nitroso-L-glutathione (GSNO) a nitric oxide (NO) donor, was found to enhance AID and iNOS expression in LoVo cells treated with 5-Aza-dC. Our findings suggest that AID and iNOS expression in cancer cells may be modified by epigenetic mechanisms, and that NO may further enhance AID and iNOS expression. Given recent plans to introduce Dnmt and HDAC inhibitors as novel cancer treatments, these findings regarding the potential for Dnmt and HDAC inhibitors to enhance expression of AID and iNOS, resulting in further cancer progression, might be taken into consideration.

Occupational exposure in methyl bromide manufacturing workers: 17-year follow-up study of urinary bromide ion concentration for biological monitoring.

To elucidate the circumstances of their occupational exposure to methyl bromide (MeBr), we conducted a 17-yr study on 124 workers employed by a MeBr manufacturer. Subjects were classified into three groups according to the nature of their work: synthesis group, filling group, and other group. Urinary concentrations of bromide ion (Br(-)) were assessed, and data attained via MeBr-health examinations were analyzed. The highest Br(-) concentrations were seen in the synthesis group, with a median value of 13.0 µg/mg CRE (2.5-51.8), followed by the filling group, with a concentration of 11.9 µg/mg CRE (3.1-34.8). Both values were significantly higher than the levels noted in the other group (p<0.001). Three major opportunities for exposure were identified: during exchange of reaction equipment for maintenance or cleaning, during operations to adjust for weight variations after filling canisters, or when canisters were recycled. Overall, however, the workplace environment concentration remained largely below the administrative control level throughout the study period. Therefore, while this was a relatively well-controlled workplace, exposure opportunities still arose when performing certain tasks, indicating the need for ongoing improvement in workplace procedures and underscoring the importance of biological monitoring.

Passive smoking is associated with lower serum HDL-C levels in school children.

BACKGROUND: In recent years, a number of studies have reported that exposure to environmental tobacco smoke (ETS) reduces high-density lipoprotein cholesterol (HDL-C) levels in children, as well as in adults. Further, a number of countries have indicated that passive smoking increases the risk of early arteriosclerosis onset. Here, to evaluate the effects of ETS exposure, we conducted a cross-sectional epidemiological study on primary school children in Japan using answers from a questionnaire survey, as well as urine cotinine and lipid metabolism-related variable measurements. METHODS: A total of 121 sixth-grade primary school children participated in this study by completing a questionnaire about their food intake, lifestyle and family smoking habits. Early in the morning, we also measured height, weight, blood pressure, serum levels of total cholesterol, triglyceride, HDL-C, and blood sugar, as well as urine levels of cotinine and creatinine under unfed conditions. RESULTS: From the questionnaire, 40 and 81 children reported being exposed and not exposed to ETS, respectively. Serum HDL-C levels, which were adjusted for the degree of corpulence and exercise habits, were significantly lower in the passive smoker group than the non-passive-smoker group (65.3 and 72.1 mg/dL, respectively; P= 0.012). In addition, proportional differences in serum HDL-C levels were also observed based on the amount of cigarettes smoked at home by family members of the child. CONCLUSIONS: Results suggest that ETS exposure at home is associated in a dose-related manner with lower serum HDL-C levels in primary school children. In addition, our results suggest that smoking in the presence of children who are not usually exposed to ETS increases the risk of arteriosclerosis. Given these findings, we strongly recommend the establishment of anti-passive-smoking measures.

Survival prognosis of Japanese with severe motor and intellectual disabilities living in public and private institutions between 1961 and 2003.

BACKGROUND: Although the prognosis for survival in people with severe functional disabilities is a serious concern for their families and health care practitioners, there have been few reports on survival rates for this population. Every year, the Japanese Association of Welfare for Persons with Severe Motor and Intellectual Disability collects anonymous records of individual registrations and deaths from all private and public institutions, excepting national institutions. We used these data to estimate the prognosis for survival. METHODS: We reviewed the records of 3221 people with severe motor and intellectual disabilities (SMID); all subjects had lived in one of 119 public or private institutions in Japan between 1961 and 2003. Kaplan-Meier survival estimates were calculated according to disability type and birth year range. RESULTS: Of the 3221 persons, 2645 were alive and 576 had died. The survival rate at the age of 20 for all subjects was 79% (95% confidence interval, 78%-81%). Among people who were unable to sit, those with lower intelligence quotients had lower survival rates. CONCLUSIONS: The survival rate among people with SMID housed in public and private institutions in Japan was much worse than that of the general population, and has not improved since the 1960s.

Lipopolysaccharide induces aberrant hypermethylation of Hic-1 in mouse embryonic fibroblasts lacking p53 gene.

BACKGROUND: The present study asked whether continuous administration with lipopolysaccharide (LPS), a potent inflammatory agent, induces aberrant methylation in the promoter region of tumor suppressor genes and p53 and/or inducible nitric oxide synthase (iNOS) genes involved in its aberrant methylation. MATERIALS AND METHODS: Mouse embryonic fibroblasts (MEFs) were prepared from mice harboring four different genotypes (p53+/+iNOS+/+, p53++iNOS-/-, p53-/-iNOS+/+ and p53-/-iNOS-/-). The MEFs were immortalized by 3T3 procedure and continuously cultured under a medium containing LPS or LPS plus interferon (IFN)-gamma during 40 passages. The methylation status in the CpG site of hypermethylated in cancer-1 (Hic-1) exon la and p16 promoter region was monitored using bisulfite-sequencing methods. RESULTS: LPS and LPS plus IFN-gamma induced de novo methylation in the CpG sites of the Hic-1 gene. This site was methylated only in p53-/- MEFs, and the mRNA expression of Hic-1 decreased in p53-/- MEFs compared to p53+/+ MEFs. The methylation patterns of Hic-1, however, were not affected by iNOS gene status. The promoter region of p16 was methylated by increasing the passage, even under the control medium, with LPS administration promoting methylation, particularly in MEFs lacking the iNOS gene. However, the methylation pattern was not significantly different between the p53 genotypes. CONCLUSION: Our preliminary study suggests that LPS induces de novo methylation in the CpG site in MEFs. For the Hic-1 gene, but not p16, the p53 gene might protect against aberrant methylation. The iNOS gene might not be involved in methylation of the Hic-1 gene, whereas the promoter region of p16 could be prone to methylation in MEFs lacking the iNOS gene.

Allergy as a possible predisposing factor for hypodontia.

The aim of this retrospective study was to identify general health problems as potential predisposing factors for hypodontia in a population of Japanese orthodontic patients. The study included 3683 individuals (1312 males and 2371 females, 13-42 years of age; mean, 23 years 7 months). Dental pantomograms (DPTs) were used to diagnose hypodontia. Health histories were obtained through a questionnaire administered by the dentist in charge. The Mantel-Haenszel test was used to determine the significance of the differences in the prevalence of health problems. The overall frequency of hypodontia was 5.8 per cent. The average number of missing teeth per patient was 1.7. There was a high prevalence of systemic complications, which included allergy, asthma, atopy, and enlarged adenoids associated with hypodontia. Only allergy showed a significant relationship with hypodontia (P < 0.01). The environmental aetiology of hypodontia is not yet fully understood. However, based on the results of this retrospective study, predisposing general health problems, especially allergy, seem to be involved.

Long-term study of urinary bisphenol A in elementary school children.

OBJECTIVES: Due to its industrial application and frequent use as a coating material for food containers, bisphenol A (4,4'-isopropylidenediphenol, BPA) is present in abundance in our environment. Data on intake levels of BPA are limited in preadolescent children in Japan. This study was designed to help us better understand the current state of BPA exposure in children in Japan. METHODS: We followed first graders (n = 104) attending school in a Tokyo suburb from 1998 until the sixth grade (2003), during which time we collected a total of three morning urine samples. Urinary BPA was analyzed using high-performance liquid chromatography isotope-dilution tandem mass spectrometry. RESULTS: Ninety-four children were followed for 5 years. Median urinary BPA level was 2.66 ng/mg creatinine (CRE) (range 0.9-38.9) at first grade (1998), 1.52 ng/mg CRE (0.4-11.8) at third grade (2000), and 0.66 ng/mg CRE (0.2-8.5) at sixth grade (2003), showing a significant decrease in urinary BPA levels over a 5-year follow-up study (p < 0.001). No significant difference was seen between boys and girls at each grade. CONCLUSIONS: Urinary levels of BPA were relatively low throughout the study period; however, as the study progressed, we observed a significant decline in levels, the reason behind which is not yet clear.