[Immune System Reaction against Environmental Pollutants].

Environmental pollutants (such as diesel exhaust particles and silica) cause disorders ranging from bronchial asthma to malignant tumors. In recent years, it has been reported that some of the signaling pathways in which environmental contaminants act in vivo are associated with innate immunity. Innate immunity recognizes ligands and induces inflammation. Those ligands are pathogen-associated molecular patterns (PAMPs: e.g., lipopolysaccharide) and danger-associated molecular patterns (DAMPs: e.g., cholesterol crystallization or uric acid crystal). Activation of innate immunity stimulates the acquired immunity system. Therefore, innate immunity regulates the strength of the general immune system. Furthermore, crystal silica, which is an environmental pollutant, activates innate immunity as a ligand. Innate immunity involves the membrane-bound Toll-like receptors (TLR) and cytoplasm-localized nucleotide-binding oligomerization domain (NOD)-like receptors (NLR). We reported the innate immunity-system-related diseases such as Crohn's disease, Blau syndrome, myelogenous leukemia, and sarcoidosis. An inflammasome complex containing NLR has attracted attention owing to its correlation with the onset of several diseases. It is reported that the inflammasome activation is related to the development of lifestyle-related diseases such as myocardial infarction and fatty liver. It is also reported that the mechanism by which crystal silica and asbestos cause inflammation involves the inflammasome activation. Analyzing the genes of innate immunity contributes to the clarification of the mechanism of disease onset caused by environmental pollutants.

Psychosocial functioning and self-rated health in Japanese school-aged children: A cross-sectional study.

Emotional and behavioral disorders in children are school-health concerns; however, Japanese screening tools for such disorders are not yet available. We examined the association between psychosocial functioning as measured by the Pediatric Symptom Checklist (PSC) and self-rated health within school settings. A cross-sectional study was conducted for 2513 fifth and eighth graders from all of the primary and secondary schools in Shunan City, Japan. The Japanese PSC had high internal consistency (Cronbach's α = 0.90) and a factor structure similar to that of the English PSC. When the cut-off values were set to ≥ 28 and ≥ 17, 4-9% and 20-39% of our respondents, respectively, reported high PSC scores. A multiple ordinal logistic regression analysis showed that the odds ratio of a positive PSC score (≥ 28) for poorer self-rated health among ratings of "very good," "good," "fair," and "poor" was 3.5 (95% confidence interval = 2.6-4.8). There was a clear association between psychosocial dysfunction identified by a PSC score ≥ 28 and poor self-rated health. We offer directions for further research on appropriate PSC cut-off values with Japanese samples.

Breakfast habits among adolescents and their association with daily energy and fish, vegetable, and fruit intake: a community-based cross-sectional study.

OBJECTIVES: To investigate breakfast eating habits on daily energy and fish, vegetable, and fruit intake in Japanese adolescents. METHODS: This study was completed as part of the Shunan Child Health Cohort Study. Two types of questionnaires, one on lifestyle habits and the other a brief-type, self-administered questionnaire on diet history, were administered to second-year junior high school students (1,876 boys and 1,759 girls) in Shunan City, Yamaguchi, Japan. The different breakfast habits were compared using the general linear model and the estimated means and P value for trend were calculated, with energy-adjusted food intake as the dependent variable and body mass index, gender, age, residential areas, and living status as covariates. RESULTS: In both males and females, the proportion of those who ate breakfast irregularly was about 10%. The daily intake of fish, vegetables, and fruit was significantly higher in those who ate breakfast with their guardians than in those who ate breakfast alone (P for trend <0.01). The daily intake of fish, seafood, and vegetables was significantly higher in those who less frequently ate cooked foods for breakfast (P for trend <0.01). Those who ate rice more frequently than bread at breakfast had a higher daily intake of fish, seafood, and vegetables (P for trend <0.01). CONCLUSIONS: Eating breakfast with the family, reducing the intake of cooked foods at breakfast, and eating breakfast with rice as a main staple food are suggested to contribute to an improved quality of diet in adolescents.

Iron load and liver enzymes in 10- and 13-year-olds.

OBJECTIVES: Iron plays a pivotal role in adult steatosis, but its role in child and adolescent steatosis is unclear. We investigated the effect of dietary iron, serum iron, and ferritin on serum transaminases and γ-glutamyltransferase in 10- and 13-year-olds. PATIENTS AND METHODS: The study included 4894 fifth and eighth graders enrolled between 2006 and 2009 in all schools in Shunan City, Japan. Multiple regression analyses were performed with adjustments for grade, sex, z score of the body mass index, serum lipids, plasma glucose, frequency of sports activities, having a single parent, number of siblings, tobacco smoking behavior, passive smoking at home, resident areas, and schools, using linear mixed models. In addition, we analyzed ferritin and insulin resistance in randomly selected subset of participants. RESULTS: Dietary iron intake was positively associated with serum alanine aminotransferase levels (standardized coefficient ß = 2.35, P = 0.019). Serum iron concentrations were associated with transaminase and γ-glutamyltransferase levels (ß = 3.22, and 4.05, respectively, P < 0.01). In the subset of 421 subjects with further serum analysis, serum ferritin levels were significantly associated with serum enzyme levels (ß = 2.43-3.35; P < 0.05) and showed significant odds ratio for the elevated alanine aminotransferase levels (1.05 for 1 SD with 95% confidence intervals 1.02-1.08). However, iron load did not show a positive association with insulin resistance. CONCLUSIONS: Although an effect size for iron is small in regression analyses, iron is implicated in increased transaminase levels in prepubertal and pubertal children.

Use of body mass index and percentage overweight cutoffs to screen Japanese children and adolescents for obesity-related risk factors.

BACKGROUND: Cutoffs based on percentage overweight (POW) are used for screening students in Japan; however, body mass index (BMI) is more common in the rest of the world. To screen for risk factors related to obesity among Japanese primary and secondary school students, we compared fasting and postprandial values, and the receiver operating characteristic (ROC) curves for the POW and BMI criteria. METHODS: The subjects were students aged 10 and 13 years living in Shunan City, Japan between 2006 and 2008 (n = 6566). POW and International Obesity Taskforce (IOTF) BMI criteria were used to screen for obesity-related risk factors. The lower (20%, 18-year-old equivalent: 25 kg/m(2)) and higher (50%, 18-year-old equivalent: 30 kg/m(2)) cutoffs were examined, and ROC curves were drawn. RESULTS: Fasting cholesterol levels were higher than postprandial levels. The prevalences of overweight/obesity were 6.6% to 10.0% using the lower cutoff and 0.6% to 5.0% using the higher cutoff. Among overweight subjects under fasting conditions, dyslipidemia was present in 12% to 52%, hypertriglyceridemia in 29% to 54%, hyperglycemia in 11% to 21%, and hypertension in 15% to 40%. Although the use of the lower and higher POW cutoffs resulted in lower sensitivity and the higher specificity, the POW and BMI ROC curves largely overlapped. However, for girls aged 10 years, the POW curve for >or=3 risks factors was lower than that of the latter (P = 0.013). CONCLUSIONS: For Japanese aged 10 and 13 years, both BMI and POW are useful for risk factor screening. However, subjects may be misclassified with dyscholesterolemia if postprandial blood samples are used.

MMP-9 and TIMP-1 in the cord blood of premature infants developing BPD.

We investigated matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) levels in the cord blood of 29 premature infants who were <30 weeks gestation. One, 8, and 14 infants developed severe, moderate and mild bronchopulmonary dysplasia (BPD), respectively, and 6 did not. MMP-9 and TIMP-1 levels in the cord blood were determined by ELISA. MMP-9/TIMP-1 ratios in the cord blood of infants who developed severe or moderate BPD (n = 9) were significantly higher than those who developed mild BPD or did not develop BPD (n = 20; P = 0.015). Multivariate linear regressions demonstrated that MMP-9 levels and MMP-9/TIMP-1 ratios in the cord blood of the premature infants correlated with the oxygen supplementation period (r = 0.58, P = 0.003 and r = 0.41, P = 0.030, respectively). The MMP-9 levels and MMP-9/TIMP-1 ratios correlated with the severity of maternal chorioamnionitis (both trend P = 0.006). The MMP-9 levels and MMP-9/TIMP-1 ratios in the cord blood may be related to the pathogenesis and severity of BPD and maternal chorioamnionitis.