Objectives: The chronic social defeat stress (CSDS) mouse model is a potentially useful system for understanding stress responses to social environments. We previously developed a mouse model of subchronic and mild social defeat stress (sCSDS) that exhibits increased body weight gain and food intake following polydipsia-like features. sCSDS mice also show avoidance behavior in a social interaction test. In this study, we examined the effects of diet quality on susceptibility to sCSDS by feeding these mice semi- and non-purified diets.Methods: Male C57BL/6J (B6; n = 82) mice were exposed to sCSDS using male ICR mice. The B6 mice were divided into four test groups: semi-purified pellet diet + sCSDS, non-purified pellet diet + sCSDS, semi-purified diet + control (no sCSDS), and non-purified diet + control.Results: Although increased body weight, and food and water intake following sCSDS exposure were consistently observed in the groups that were fed semi- and non-purified diets, social avoidance behavior was influenced by food type (i.e., sCSDS mice fed semi-purified diet showed the greatest social avoidance behavior). In addition, the rates of stress susceptibility were estimated at 73.9 and 34.8% in sCSDS mice fed semi-purified and non-purified diets, respectively (P < 0.05). For comparison, the susceptible-like phenotype rates were estimated at 12.5 and 8.3% in healthy control mice fed semi-purified and non-purified diets, respectively.Discussion: These results suggest that diet quality affects the vulnerability of mice to social defeat stress.
In this study, we investigated the effects of dietary supplementation of Citrus tumida hort. ex Tanaka on food intake, body and fat tissue weights, and metabolic profiles of plasma and liver in mice. Supplementation with 5% (w/w) of peels of immature C. tumida (PIC) for 4 weeks significantly suppressed body weight gain and decreased adipose tissue weight in epididymal, perirenal, and subcutaneous fats. Metabolome analyses showed that 2-hydroxyvaleric acid levels were reduced in the blood plasma of mice fed with PIC. PIC supplementation significantly elevated dipeptide (Thr-Asp, Ser-Glu, and Ala-Ala), glucuronic acid, and S-methylglutathione levels, and significantly reduced betaine aldehyde levels in the liver. In conclusion, PIC supplementation affects the metabolism of fatty acids, pectin, glutathione, and choline, showing potential beneficial effects for metabolic syndrome and obesity. PIC may be developed as a functional food and used in the treatment of these diseases. Peel of immature C. tumida supplementation impacts body weight followed by metabolic changes.
The γ-Reθt transition model was adopted to predict the boundary layer transition on Japan Aerospace Exploration Agency (JAXA) high-lift configuration model. A comparison among fully turbulent computation, computation with transition model and wind tunnel test was conducted. Lift and drag characteristics were discussed based on pressure coefficient distributions at several wing sections. Boundary layer transition position was compared with wind tunnel experiment result by checking starting position of intermittency of the γ-Reθt transition model and distribution of skin friction coefficient. Predicted transition position agreed with experimental results except for the inboard section of mother wing and engine nacelle. To investigate the cause of discrepancy between the computation and experiment, crossflow velocity component within the boundary layer was visualized and it was shown that the large crossflow velocity was seen at inboard section of mother wing where the discrepancy appears significantly. Surface flow visualization using oil flow was carried out to see the flow characteristics on the slat.
Experiments were conducted to investigate the effect of the Bacillus subtilis var. natto fermented soybean (FS) on growth performance, microbial activity in the caeca and cytokine gene expression in spleen of domestic meat type chickens. Chicks were fed commercial diets supplemented with 0 (control), 1 or 2% FS for 80 days from 0 to 80 days of age, and a fourth group of chicks were fed control diet from 0 to 27 days of age, and then fed a 2% FS diet from 28 to 80 days of age. Supplementation with FS did not decrease feed intake compared to chicks fed the control diet, and there were no significant differences in body weight gain and feed efficiency due to dietary treatment. FS supplementation had no effect on carcass weight, breast and thigh meat composition, or abdominal fat deposition. There were no significant differences in pH, NH3-N concentration, or number of microorganisms in the cecum content in each group; however, total acetic acid concentration increased (P<0.05) in chicks fed the 2% FS supplemented diet from 0 to 80 days of age. Supplementation with FS did not affect IFN-γ, IL-4 and IL-13 gene expression in spleens.It can be concluded from this study that supplementing FS to meat type chicken diets has no deleterious effect on the growth performance, and has beneficial effects on intestinal microbial activity, as observed by increases in VFA concentration.
Citrus fruits have several potential benefits for maintaining our health. In this study, we investigated the anti-obesity effects of immature Citrus tumida hort. ex Tanaka (C. tumida) peels using an acute obesity mice model. C57BL/6J male mice were divided into 2 groups; HFD-LL subjected to a high fat diet (HFD) and constant light exposure (LL), and HFDC-LL subjected to a HFD containing immature peel powder of C. tumida (5% w/w) and LL. Dietary ingestion of immature C. tumida peels significantly suppressed body weight gain following decreased epidydimal, perirenal, and subcutaneous fat weights. Blood levels of triglyceride and total cholesterol in the HFDC-LL were significantly lower than those in the HFD-LL group; however, there was no significant difference in food or calorie intake between the 2 groups. These results suggested that immature C. tumida peels have a beneficial effect on the prevention of obesity and metabolic syndrome via its biochemical activities of lipid metabolism.
