Seasonal changes in hydration in free-living Japanese children and adolescents.

Changes in hydration status occur throughout the day affecting physiological and behavioral functions. However, little is known about the hydration status of free-living Japanese children and the seasonality of this response. We evaluated hydration status estimated by urine osmolality (Uosm) in 349 children (189 boys and 160 girls, 9.5 ± 2.6 years, range: 6 to 15 years) upon waking at home and during a single school day in spring (April) and summer (July). Further, we assessed the efficacy of employing self-assessment of urine color (UC, based on an 8-point scale) by children to monitor their hydration status. Early morning Uosm was greater in the spring (903 ± 220 mOsm L-1; n = 326) as compared to summer (800 ± 244 mOsm L-1; n = 125) (P = 0.003, paired t-test, n = 104). No differences, however, were observed in Uosm during the school day (P = 0.417, paired t-test, n = 32). While 66% and 50% of children were considered underhydrated (Uosm ≧800 mOsm L-1) upon waking in the spring and summer periods respectively, more children were underhydrated (∼12%) during the school day. Self-reported UC was similar between seasons as assessed in the morning and school day (P ≧ 0.101, paired t-test), which differed from the pattern of responses observed with Uosm. We showed that a significant number of Japanese children are likely underhydrated especially in the spring period. Children do not detect seasonal changes in hydration from self-assessed UC, limiting its utility to manage hydration status in children.

Amelioration of skewed Th1/Th2 balance in tumor-bearing and asthma-induced mice by oral administration of Agaricus blazei extracts.

We showed in a previous study that hot-water extracts of Agaricus blazei (Agaricus extracts) had anti-tumor activity to Meth A fibrosarcoma, but it remains unclear whether the Agaricus extracts ameliorate the skewed balance of type-1 T helper (Th1) and type-2 T helper (Th2) cells. We examined whether Agaricus extracts effect the skewed Th1/Th2 balance in tumor-bearing and asthma-induced mice. When Meth A-bearing mice were given orally either Agaricus extracts or water once a day starting 5 days after tumor implantation, spleen T cells, prepared from tumor-bearing mice treated with Agaricus extracts, in response to anti-CD3 monoclonal antibody produced significantly higher levels of interferon gamma (IFN-gamma) than that of controls. The mRNA expression of IFN-gamma-inducing protein 10 and the frequency of CD69(+) or CD49d(+) cells, among activated T cells infiltrated into tumors, significantly increased in Agaricus-treated mice, compared with those of tumor-controls. In asthma-induced mice, treatment with the Agaricus extracts caused significant downregulation of OVA-specific antibody responses of IgG1 and IgE but not of IgG2a, and significantly decreased total cell numbers, levels of interleukin 5, and eosinophil numbers in bronchial alveolar lavage fluids. IFN-gamma production by anti-CD3-stimulated spleen cells, obtained from Agaricus-treated mice, significantly increased. Our results strongly suggest that oral administration of Agaricus extracts ameliorates the Th1/Th2 balance from the Th2-skewed conditions.