96 research outputs found

    Flight and Dietary Antioxidants Influence Antioxidant Expression and Activity in A Migratory Bird

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    Ecologically-relevant factors such as exercise and diet quality can directly influence how physiological systems work including those involved in maintaining oxidative balance; however, to our knowledge, no studies to date have focused on how such factors directly affect expression of key components of the endogenous antioxidant system (i.e., transcription factors, select antioxidant genes, and corresponding antioxidant enzymes) in several metabolically active tissues of a migratory songbird. We conducted a 3-factor experiment that tested the following hypotheses: (H1) Daily flying over several weeks increases the expression of transcription factors NRF2 and PPARs as well as endogenous antioxidant genes (i.e., CAT, SOD1, SOD2, GPX1, GPX4), and upregulates endogenous antioxidant enzyme activities (i.e., CAT, SOD, GPx). (H2) Songbirds fed diets composed of more 18:2n-6 PUFA are more susceptible to oxidative damage and thus upregulate their endogenous antioxidant system compared to when fed diets with less PUFA. (H3) Songbirds fed dietary anthocyanins gain additional antioxidant protection and thus upregulate their endogenous antioxidant system less compared to songbirds not fed anthocyanins. Flight training increased the expression of 3 of the 6 antioxidant genes and transcription factors measured in the liver, consistent with H1, but for only one gene (SOD2) in the pectoralis. Dietary fat quality had no effect on antioxidant pathways (H2) whereas dietary anthocyanins increased the expression of select antioxidant enzymes in the pectoralis, but not in the liver (H3). These tissue-specific differences in response to flying and dietary antioxidants are likely explained by functional differences between tissues as well as fundamental differences in their turnover rates. The consumption of dietary antioxidants along with regular flying enables birds during migration to stimulate the expression of genes involved in antioxidant protection likely through increasing the transcriptional activity of NRF2 and PPARs, and thereby demonstrates for the first time that these relevant ecological factors affect the regulation of key antioxidant pathways in wild birds. What remains to be demonstrated is how the extent of these ecological factors (i.e., intensity or duration of flight, amounts of dietary antioxidants) influences the regulation of these antioxidant pathways and thus oxidative balance

    Seasonal and Interspecific Variation in Frugivory by a Mixed Resident-Migrant Overwintering Songbird Community

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    Many temperate passerine bird species switch from diets of mostly invertebrates in the spring and summer to diets that include fruit and seeds in the fall and winter. However, relatively few studies have quantified diet composition or the extent of seasonal shifts during the non-breeding period, particularly among species and across communities with both residents and migrants. We measured carbon and nitrogen stable isotope values in food items (fruits, C3 and C4seeds, and insects from various trophic levels and plant communities) and in multiple tissues (feathers and plasma/whole blood) from 11 species of songbirds wintering in the southeastern U.S. We combined these diet and tissue values with empirically derived discrimination factors and used concentration-dependent mixing models to quantify seasonal diet shifts. We also validated mixing model results with data from fecal samples. Diets in this bird community, as delineated N and C isotopic space, diverged in the fall and winter relative to the summer as consumption of fruits and seeds increased. Across this songbird community, estimated contributions of fruit to plasma/whole blood increased from 16.2 ± 7.5% in the fall (mean ± SD; range: 4–26%) to 21.7 ± 10.3% (range: 9–37%) in the winter, while contributions of seeds increased from 29.4 ± 2.6% (range: 28–32%) in the fall to 36.6 ± 4.8% (range: 32–42%) in the winter. Fecal data showed qualitatively similar trends to mixing models, but consistently estimated higher contributions of fruit. Our work indicates that fruits and seeds constitute substantial sources of sustenance for non-breeding songbirds, there is considerable separation of resource use among species in the fall and winter, and fecal estimates of contributions to songbird tissues should be interpreted cautiously

    Safety and Efficacy of Teduglutide in Pediatric Patients With Intestinal Failure due to Short Bowel Syndrome : A 24-Week, Phase III Study

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    Background This study evaluated the safety and efficacy of teduglutide in pediatric patients with short bowel syndrome-associated intestinal failure (SBS-IF). Methods A 24-week, phase III trial with 2 randomized, double-blind teduglutide dose groups and a nonblinded standard of care (SOC) arm was used; patients received 0.025 mg/kg or 0.05 mg/kg teduglutide once daily. Safety end points included treatment-emergent adverse events (TEAEs) and growth parameters. The primary efficacy/pharmacodynamic end point was the number of patients who achieved a >= 20% reduction in parenteral support (PS) from baseline at week 24. Results All 59 enrolled patients completed the study (0.025 mg/kg, n = 24; 0.05 mg/kg, n = 26; SOC, n = 9). Baseline demographics and disease characteristics were comparable among groups. TEAEs were reported by 98% and 100% of patients in the teduglutide and SOC groups, respectively. The most common TEAEs in the teduglutide-treated groups were pyrexia and vomiting. The primary end point was achieved by 13 (54.2%), 18 (69.2%), and 1 (11.1%) patients who received 0.025 mg/kg teduglutide, 0.05 mg/kg teduglutide, and SOC, respectively (P <0.05 vs SOC). Both 0.025-mg/kg and 0.05-mg/kg teduglutide groups showed clinically significant reductions in PS volume (P <0.05 vs SOC), PS calories, days per week and hours per day of PS infusions, and increases in enteral nutrition and plasma citrulline at week 24 compared with baseline. Two (8.3%, 0.025 mg/kg teduglutide) and 3 patients (11.5%, 0.05 mg/kg teduglutide) achieved enteral autonomy. Conclusion The safety profile of teduglutide was similar to that reported previously in children and adults. Treatment with teduglutide was associated with significant reductions in PS for pediatric patients with SBS-IF over 24 weeks.Peer reviewe

    Safety Findings in Pediatric Patients During Long-Term Treatment With Teduglutide for Short-Bowel Syndrome-Associated Intestinal Failure : Pooled Analysis of 4 Clinical Studies

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    Background This analysis assessed combined safety data from 4 clinical studies of teduglutide in pediatric patients with short-bowel syndrome-associated intestinal failure (SBS-IF). Methods Safety data from teduglutide-treated patients in 4 clinical trials were pooled. The completed 12-week and 24-week phase 3 core studies (NCT01952080/EudraCT 2013-004588-30 and NCT02682381/EudraCT 2015-002252-27) enrolled children aged 1-17 years with SBS-IF. Patients could elect to enroll in ongoing open-label extensions (NCT02949362/EudraCT 2016-000863-17 and NCT02954458/EudraCT 2016-000849-30). Interim data from ongoing studies were included. Results Safety data are reported for 89 pediatric patients treated with teduglutide for a median (range) of 51.7 (5.0-94.7) weeks. Adverse events (AEs) were reported in all patients; the most common were vomiting (51.7%), pyrexia (43.8%), upper respiratory tract infection (41.6%), and cough (33.7%). Thirty-five patients (39.3%) had AEs considered related to teduglutide treatment; abdominal pain and vomiting were most frequent (5.6% each). Three serious AEs in 3 patients (3.4%) were considered related to teduglutide treatment: ileus, d-lactic acidosis, and gastrointestinal obstruction due to hard stools. All 3 events resolved. One cecal polyp was detected, which was not biopsied or found on repeat colonoscopy. No cases of neoplasia occurred. Conclusion Based on integrated data from 4 clinical studies, including long-term follow-up forPeer reviewe

    Loss of a single Hic1 allele accelerates polyp formation in ApcΔ716 mice

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    Adenomatous polyposis coli (APC) gene mutations have been implicated in familial and sporadic gastrointestinal (GI) cancers. APC mutations are associated with autosomal dominant inheritance of disease in humans. Similarly, mice that contain a single mutant APC gene encoding a protein truncated at residue 716 (ApcΔ716) develop multiple polyps throughout the GI tract as early as 4 weeks after birth. Inactivation of another tumor suppressor gene, Hypermethylated in Cancer 1 (HIC1), often occurs in human colon cancers, among others, via CpG island hypermethylation. Homozygous deletion of Hic1 in mice results in major developmental defects and embryonic lethality. Hic1 heterozygotes have previously been shown to develop tumors of a variety of tissue types. We now report that loss of a single Hic1 allele can promote crypt hyperplasia and neoplasia of the GI tract, and Hic1+/−, Apc+/Δ716 double heterozygotes (DH) develop increased numbers of polyps throughout the GI tract at 60 days. Hic1 expression is absent in polyps from DH mice, with concomitant increased expression of two transcriptional repression targets of Hic1, Sirt1 and Sox9. Together, our data suggest that loss of a gene frequently silenced via epigenetic mechanisms, Hic1, can cooperate with loss of a gene mutated in GI cancer, Apc, to promote tumorigenesis in an in vivo model of multiple intestinal neoplasia

    Obesity prevention and personal responsibility: the case of front-of-pack food labelling in Australia

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    <p>Abstract</p> <p>Background</p> <p>In Australia, the food industry and public health groups are locked in serious struggle for regulatory influence over the terms of front-of-pack food labelling. Clear, unambiguous labelling of the nutritional content of pre-packaged foods and of standardized food items sold in chain restaurants is consistent with the prevailing philosophy of 'personal responsibility'. An interpretive, front-of-pack labelling scheme has the capacity to encourage healthier patterns of eating, and to be a catalyst for improvements in the nutritional quality of food products through re-formulation. On the other hand, the strength of opposition of the Australian Food and Grocery Council to 'Traffic Light Labelling', and its efforts to promote a non-interpretive, voluntary scheme, invite the interpretation that the food industry is resistant to any reforms that could destabilise current (unhealthy) purchasing patterns and the revenues they represent.</p> <p>Discussion</p> <p>This article argues that although policies that aim to educate consumers about the nutritional content of food are welcome, they are only one part of a broader basket of policies that are needed to make progress on obesity prevention and public health nutrition. However, to the extent that food labelling has the capacity to inform and empower consumers to make healthier choices - and to be a catalyst for improving the nutritional quality of commercial recipes - it has an important role to play. Furthermore, given the dietary impact of meals eaten in fast food and franchise restaurants, interpretive labelling requirements should not be restricted to pre-packaged foods.</p> <p>Summary</p> <p>Food industry resistance to an interpretive food labelling scheme is an important test for government, and a case study of how self-interest prompts industry to promote weaker, voluntary schemes that pre-empt and undermine progressive public health regulation.</p

    Gendering the careers of young professionals: some early findings from a longitudinal study. in Organizing/theorizing: developments in organization theory and practice

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    Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales
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