The British journal of nutrition
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Muscle atrophy increases the production of reactive oxygen species and the expression of atrophy-related genes, which are involved in the ubiquitin-proteasome system. In the present study, we investigated the effects of β-carotene on oxidative stress (100 μM-H2O2)-induced muscle atrophy in murine C2C12 myotubes. β-Carotene (10 μM) restored the H2O2-induced decreased levels of myosin heavy chain and tropomyosin (P< 0·05, n 3) and decreased the H2O2-induced increased levels of ubiquitin conjugates. β-Carotene reduced the H2O2-induced increased expression levels of E3 ubiquitin ligases (Atrogin-1 and MuRF1) and deubiquitinating enzymes (USP14 and USP19) (P< 0·05, n 3) and attenuated the H2O2-induced nuclear localisation of FOXO3a. Furthermore, we determined the effects of β-carotene on denervation-induced muscle atrophy. ⋯ At day 3 after denervation, the ratio of soleus muscle mass in the denervated leg to that in the sham leg was significantly higher in β-carotene-administered mice than in control vehicle-administered ones (P< 0·05, n 5). In the denervated soleus muscle, β-carotene administration significantly decreased the expression levels of Atrogin-1, MuRF1, USP14 and USP19 (P< 0·05, n 5) and the levels of ubiquitin conjugates. These results indicate that β-carotene attenuates soleus muscle loss, perhaps by repressing the expressions of Atrogin-1, MuRF1, USP14 and USP19, at the early stage of soleus muscle atrophy.
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Previous national nutrition surveys in Irish adults did not include blood samples; thus, representative serum 25-hydroxyvitamin D (25(OH)D) data are lacking. In the present study, we characterised serum 25(OH)D concentrations in Irish adults from the recent National Adult Nutrition Survey, and determined the impact of vitamin D supplement use and season on serum 25(OH)D concentrations. Of the total representative sample (n 1500, aged 18+ years), blood samples were available for 1132 adults. ⋯ These prevalence estimates were much higher during winter time. While vitamin D supplement use has benefits in terms of vitamin D status, at present rates of usage (17.5 % of Irish adults), it will have only very limited impact at a population level. Food-based strategies, including fortified foods, need to be explored.
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The aim of the present study was to describe the present knowledge of healthcare professionals and the practices surrounding enteral feeding in the UK and Irish paediatric intensive care unit (PICU) and propose recommendations for practice and research. A cross-sectional (thirty-four item) survey was sent to all PICU listed in the Paediatric Intensive Care Audit Network (PICANET) database (http://www.picanet.org.uk) in November 2010. The overall PICU response rate was 90 % (27/30 PICU; 108 individual responses in total). ⋯ There was considerable variation across respondents about which procedures required fasting and the duration of this fasting. The present survey has highlighted the variability of the present enteral feeding practices across the UK and Ireland, particularly with regard to the use of GRV and fasting for procedures. The present study highlights a number of recommendations for both practice and research.