Isolation and characterization of baker's yeast capable of strongly activating a macrophage.

A physiological function of the ß-glucans which constitute the cell wall of Saccharomyces cerevisiae is to activate immune cells. Here, we focused on the immunostimulation ability of S. cerevisiae itself to give this ability to fermented foods including yeast. Previously, we found that in S. cerevisiae the deletion of MCD4 gene causes exposure of ß-glucans on the cell surface and that the mcd4 deletion mutant strongly enhances immunity in vitro and in vivo. However, this is not a practical strain but a genetically modified strain with an antibiotic resistance gene, and growth was very slow. The aim of this study was to acquire a practical strain capable of strongly activating a macrophage. The parental strain y-21 was mutated with ethyl methanesulfonate, and the resulting strain was screened. Two mutants (AP-57 and AQ-37) were obtained. AQ-37 had the same fermentation capacity as y-21. In addition, a mutation point of AQ-37 was identified, suggesting that the mutation of NDD1 gene affects the cell wall structure and confers a high ability for macrophage stimulation. The obtained yeast may activate immune cells in materials to which the yeast is added.

Isolation of diploid baker's yeast capable of strongly activating immune cells and analyses of the cell wall structure.

Diploid baker's yeast capable of strongly activating a mouse macrophage was constructed based on haploid mutant AQ-37 obtained previously. The obtained strain BQ-55 activated also human immune cells. To clarify a factor for the activation, the cell wall structure, especially the ß-glucan structure, was analyzed, suggesting that the length of branching, ß-1,6-glucan, may be one of the factors.

Comparison of physical activity energy expenditure in Japanese adolescents assessed by EW4800P triaxial accelerometry and the doubly labelled water method.

The present study compared the accuracy of triaxial accelerometry and the doubly labelled water (DLW) method for measuring physical activity (PA) in Japanese adolescents. A total of sixty adolescents aged 12-15 years were analysed. The total energy expenditure (TEE) was measured over 7 d by the DLW method and with an EW4800P triaxial accelerometer (Panasonic Corporation). The measured (RMR)(m) and predicted RMR (RMR(p)) were 5·7 (SD 0·9) and 6·0 (SD 1·0) MJ/d, respectively. TEE measured by the DLW method and accelerometry using RMR(m) or RMR(p) were 11·0 (SD 2·6), 10·3 (SD 1·9), and 10·7 (SD 2·1) MJ/d, respectively. The PA levels (PAL) measured by the DLW method using RMR(m) or RMR(p) were 1·97 (SD 0·31) and 1·94 (SD 0·31) in subjects who exercised, and 1·85 (SD 0·27) and 1·74 (SD 0·29) in subjects who did not exercise. The percentage of body fat correlated significantly with the percentage difference between RMR(m) v. RMR(p), TEE, PA energy expenditure (PAEE) and PAL using RMR(p), and PAL using RMR(m) assessed by the DLW method and accelerometry. The present data showed that while accelerometry estimated TEE accurately, it did not provide the precise measurement of PAEE and PAL. The error in accelerometry was attributed to the prediction error of RMR and assessment in exercise.

Absorption of dietary licorice isoflavan glabridin to blood circulation in rats.

Bioavailability of glabridin was elucidated to show that this compound is one of the active components in the traditional medicine licorice. Using a model of intestinal absorption, Caco-2 cell monolayer, incorporation of glabridin was examined. Glabridin was easily incorporated into the cells and released to the basolateral side at a permeability coefficient of 1.70+/-0.16 cm/s x 10(5). The released glabridin was the aglycone form and not a conjugated form. Then, 10 mg (30 micromol)/kg body weight of standard chemical glabridin and licorice flavonoid oil (LFO) containing 10 mg/kg body weight of glabridin were administered orally to rats, and the blood concentrations of glabridin was determined. Glabridin showed a maximum concentration 1 h after the dose, of 87 nmol/L for standard glabridin and 145 nmol/L for LFO glabridin, and decreased gradually over 24 h after the dose. The level of incorporation into the liver was about 0.43% of the dosed amount 2 h after the dose. These detected glabridins were in the aglycone form and not conjugated forms. The bioavailability was calculated to be AUC(inf) of 0.825 and 1.30 microM.h and elimination T(1/2 )of 8.2 and 8.5 h for standard glabridin and LFO, respectively. Adipocytokine levels were determined in the rats. The secreted amount of monocyte chemoattractant protein-1 was significantly lower in the glabridin group compared to control vehicle group. Thus, dietary glabridin was at least partly incorporated into the body in an unchanged form, though most dietary flavonoids are converted to non-active conjugate forms during intestinal absorption.

Resting energy expenditure (REE) in six- to seventeen-year-old Japanese children and adolescents.

Accurate estimation of resting energy expenditure (REE) in children and adolescents is important to establish estimated energy requirements for the Japanese population. Our objectives were 1) to determine the REE of 6- to 17-y-old Japanese children and adolescents by indirect calorimetry in order to estimate energy expenditure for this group, 2) to compare measured REE with predicted REE to determine the accuracy of predictive equations of REE for Japanese children and adolescents, and 3) to derive new predictive equations for REE for Japanese children and adolescents based on measured REE. REE was measured in 221 Japanese children and adolescents, aged 6 to 17 y old (113 boys and 108 girls) using a ventilated indirect calorimeter. Anthropometric and body composition measurements were also performed. REE expressed as absolute values increased with age in both genders, and there was a significant difference between genders in the 12-17 y age group. REE was strongly correlated with body weight (BW) and fat-free mass (FFM). REE adjusted for BW or FFM decreased with age in both genders, and a gender difference was still observed in the 12-17 y age group after this adjustment. The highest accuracy of prediction was achieved using the Dietary Reference Intake for Japanese (1969) for boys and the Molnar equation for girls. Step-down multiple regression analysis was carried out using either a combination of age, gender, BW, and height, or a combination of age, gender, FFM, and fat mass (FM). The predictive equation accounted for 75% (R2) and 76% of the variance, respectively. In conclusion, absolute REE increased and REE adjusted for BW or FFM decreased with age. The major determinant of REE was FFM, but significant gender differences were observed in the 12-17 y range for both absolute REE and adjusted REE.