l-Arginine administration attenuates airway inflammation by altering l-arginine metabolism in an NC/Nga mouse model of asthma.

Changes in l-arginine metabolism, including increased arginase levels and decreased nitric oxide production, are involved in the pathophysiology of asthma. In this study, using an intranasal mite-induced NC/Nga mouse model of asthma, we examined whether administration of l-arginine ameliorated airway hyperresponsiveness and inflammation by altering l-arginine metabolism. Experimental asthma was induced in NC/Nga mice via intranasal administration of mite crude extract (50 µg/day) on 5 consecutive days (days 0-4, sensitization) and on day 11 (challenge). Oral administration of l-arginine (250 mg/kg) was performed twice daily on days 5-10 for prevention or on days 11-13 for therapy. On day 14, we evaluated the inflammatory airway response (airway hyperresponsiveness, the number of cells in the bronchoalveolar lavage fluid, and the changes in pathological inflammation of the lung), arginase expression and activity, l-arginine bioavailability, and the concentration of NOx, the end products of nitric oxide. Treatment with l-arginine ameliorated the mite-induced inflammatory airway response. Furthermore, l-arginine administration attenuated the increases in arginase expression and activity and elevated the NOx levels by enhancing l-arginine bioavailability. These findings indicate that l-arginine administration may contribute to the improvement of asthmatic symptoms by altering l-arginine metabolism.

Associations of serum retinol, α-tocopherol, and γ-tocopherol with biomarkers among healthy Japanese men.

Retinol, α-tocopherol, and γ-tocopherol are fat-soluble vitamins acting as antioxidants via the prevention of lipid oxidation. Little is known about circulatory levels in healthy individuals. The present cross-sectional study aimed at elucidating the relationship between these antioxidants and clinical biomarkers in 206 male (median age 41 years, range 23-67) employees from companies located in the Okayama Prefecture, Japan. Subjects younger than 40 years (n = 94) showed a positive association of the frequency of alcohol consumption with the circulating retinol (ß = 0.344, p = 0.001) and γ-tocopherol levels (ß = 0.219, p = 0.041), and an inverse association of fast insulin with serum retinol (ß = -0.301, p = 0.009). In participants older than 40 years (n = 112) we found that an inverse association of HOMA-R with serum retinol (ß = -0.262, p = 0.021), α-tocopherol (ß = -0.236, p = 0.035), and γ-tocopherol levels (ß = -0.224, p = 0.052); and cigarette smoking was inversely associated with the levels of serum α-tocopherol (ß = -0.286, p = 0.008) and γ-tocopherol (ß = -0.229, p = 0.040). We further found negative relationships between serum ferritin and the retinol (ß = -0.211, p = 0.032) and α-tocopherol levels (ß = -0.223, p = 0.022) in men over 40 years of age. The present study suggests that the circulatory levels of antioxidant vitamins may modulate the action of insulin and that higher levels of iron might decrease the levels of antioxidant vitamins in the blood.

Relationship between ceruloplasmin and oxidative biomarkers including ferritin among healthy Japanese.

Serum ceruloplasmin (CP), a marker relevant to copper metabolism, is one of famous inflammation markers with a reduction in Wilson's disease, whereas serum ferritin is a marker relevant to iron metabolism. Recently, ferritin is pointed out to be related with oxidative stress. However, there is still no population research which showed the relation of CP and ferritin. Therefore, we investigated the relationship between CP and ferritin including oxidative stress biomarkers among healthy Japanese (n = 389). We measured serum CP, ferritin, Fe, high-sensitivity C-reactive protein (hs-CRP), and urinary oxidative stress biomarkers [H2O2, 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-isoprostane] and so on. Subjects showed that age; 41.7 ± 10.0 (year), CP; 31.9 ± 6.8 (mg/dl), ferritin; 123.5 ± 121.0 (ng/ml), hs-CRP; 0.89 ± 2.53 (mg/l), 8-OHdG; 10.2 ± 4.4 [ng/mg creatinine (Cre)] and H2O2; 6.5 ± 10.9 (µM/g Cre), (All data mentioned above were expressed as mean ± SD). CP was significantly and positively correlated with hs-CRP and inversely correlated with ferritin, Fe and 8-OHdG. By a multiple logistic regression analysis, odds ratio of CP according to quartiles of hs-CRP was 4.86, and according to quartiles of 8-OHdG was 0.39 after adjusting for age and other confounding factors. In conclusion, our findings suggest that CP was an antioxidative biomarker which controls oxidative stress, whereas ferritin was a marker which may participate in the generation of oxidative stress.

Relationship of experience and the place of work to the level of competency among public health nurses in Japan.

AIM: To examine the actual competencies of public health nurses (PHNs) working in public organizations in Japan in order to clarify the relationship between the level of competency and the number of years of experience and the place of work. METHODS: The subjects were 1799 full-time PHNs working at 135 prefectural public health centers and 115 municipal health centers, which were randomly selected. Each subject received a questionnaire in the mail, requesting basic personal information and a self-evaluation of six levels of achievement in 11 topics in five categories of competencies. RESULTS: The number of respondents was 1261 (70.1%), with a total of 1184 valid responses (65.8%). In terms of the level of competency, the average score was >3 for all items and the number of PHNs who achieved Ladders 5 and 6 was low, with very few achieving Ladder 6, despite having more years of experience. Furthermore, the level of achievement depended on the workplace, position, and academic background. CONCLUSION: The tasks regarding the education of PHNs in Japan are to establish achievement goals clearly and incrementally and to develop methods and systems that consistently and systematically increase competencies, not only in basic undergraduate education, but also for employed PHNs, through specialized education. In particular, educational methods that lead to high-quality experiences need to be selected in order to develop competencies.