169 research outputs found
Contribution of intestinal- and cereal-derived phytase activity on phytate degradation in young broilers
There is little consensus as to the capability of poultry to utilize dietary phytate without supplemental phytase. Therefore, an experiment was conducted to examine the extent to which endogenous phytase of intestinal and cereal origin contributes to phytate degradation in birds aged 0 to 14 d posthatch. Ross 308 broilers (n = 720) were fed one of 4 experimental diets with differing dietary ingredient combinations and approximate total phytate levels of 10 g/kg, dietary phytase activity analyzed at 460 U/kg, dietary calcium (Ca) levels of 11 g/kg, and nonphytate-phosphorus (P) levels of 4 g/kg. Broiler performance, gizzard, duodenum, jejunum and ileum pH, Ca and P digestibility and solubility, amount of dietary phytate hydrolyzed in the gizzard, jejunum, and ileal digesta phytase activity were analyzed at d 4, 6, 8, 10, 12, and 14 posthatch. Intestinal endogenous phytase activity increased significantly (P < 0.001) between d 4 and 6, resulting in increased phytate hydrolysis in the gizzard (P = 0.003), jejunum (P < 0.001), and ileum (P < 0.001). Phytase activity and phytate hydrolysis continued to increase with age, with a greater phytase activity and associated increase in phytate hydrolysis and mineral utilization between d 10 and 12. Gizzard and jejunum Ca and P solubility and ileal Ca and P digestibility increased significantly (P < 0.001), and gastrointestinal pH decreased significantly (P < 0.001) between d 4 and 6. By d 14, phytase activity recovered in the ileum was approximately 45 U/kg. There were strong correlations between phytase activity measured in the ileum and phytate hydrolyzed in the gizzard (r = 0.905, P < 0.001), jejunum (r = 0.901, P = 0.023), and ileum (r = 0.938, P = 0.042). This study shows intestinal- and dietary-derived endogenous phytase activity is responsible for phytate-P hydrolysis in broilers
In vitro versus in situ evaluation of the effect of phytase supplementation on calcium and phosphorus solubility in soya bean and rapeseed meal broiler diets
1. In vitro assays provide a sensitive and economic tool to evaluate dietary effects, but have limitations. In this study, the effect of phytase supplementation on solubility, and presumed availability, of calcium (Ca) and phosphorus (P) in soybean meal (SBM) and rapeseed meal (RSM) based diets was evaluated both in situ and by a 2-step in vitro digestion assay that simulated the gastric and small intestine (SI) phases of digestion
Isoforms of U1-70k control subunit dynamics in the human spliceosomal U1 snRNP
Most human protein-encoding genes contain multiple exons that are spliced together, frequently in alternative arrangements, by the spliceosome. It is established that U1 snRNP is an essential component of the spliceosome, in human consisting of RNA and ten proteins, several of which are post- translationally modified and exist as multiple isoforms. Unresolved and challenging to investigate are the effects of these post translational modifications on the dynamics, interactions and stability of the particle. Using mass spectrometry we investigate the composition and dynamics of the native human U1 snRNP and compare native and recombinant complexes to isolate the effects of various subunits and isoforms on the overall stability. Our data reveal differential incorporation of four protein isoforms and dynamic interactions of subunits U1-A, U1-C and Sm-B/B’. Results also show that unstructured post- ranslationally modified C-terminal tails are
responsible for the dynamics of Sm-B/B’ and U1-C and that their interactions with the Sm core are controlled by binding to different U1-70k isoforms and their phosphorylation status in vivo. These results therefore provide the important functional link between proteomics and structure as well as insight into the dynamic quaternary structure of the native U1 snRNP important for its function.This work was funded by: BBSRC (OVM), BBSRC and EPSRC (HH and NM), EU Prospects (HH), European Science Foundation (NM), the Royal Society (CVR), and fellowship from JSPS and HFSP (YM and DAPK respectively)
Variations in influenza vaccination coverage among the high-risk population in Sweden in 2003/4 and 2004/5: a population survey
<p>Abstract</p> <p>Background</p> <p>In Sweden, the vaccination campaign is the individual responsibility of the counties, which results in different arrangements. The aim of this study was to find out whether influenza vaccination coverage rates (VCRs) had increased between 2003/4 and 2004/5 among population at high risk and to find out the influence of personal preferences, demographic characteristics and health care system characteristics on VCRs.</p> <p>Methods</p> <p>An average sample of 2500 persons was interviewed each season (2003/4 and 2004/5). The respondents were asked whether they had had an influenza vaccination, whether they suffered from chronic conditions and the reasons of non-vaccination. For every county the relevant health care system characteristics were collected via a questionnaire sent to the medical officers of communicable diseases.</p> <p>Results</p> <p>No difference in VCR was found between the two seasons. Personal invitations strongly increased the chance of having had a vaccination. For the elderly, the number of different health care professionals in a region involved in administering vaccines decreased this chance.</p> <p>Conclusion</p> <p>Sweden remained below the WHO-recommendations for population at high risk due to disease. To meet the 2010 WHO-recommendation further action may be necessary to increase vaccine uptake. Increasing the number of personal invitations and restricting the number of different administrators responsible for vaccination may be effective in increasing VCRs among the elderly.</p
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What are the factors driving antimicrobial resistance? Perspectives from a public event in London, England.
BACKGROUND: Antimicrobial resistance is driven by multiple factors. Resolving the threat to human and animal health presented by drug-resistant infections remains a societal challenge that demands close collaboration between scientists and citizens. We compared current public views about key contributing factors to antimicrobial resistance with those expressed by experts.
METHODS: Overarching factors contributing to antimicrobial resistance were identified following a review of literature. The factors were then described in plain language and attached to ballot boxes at a public engagement event organised by a university. Responses to each factor were counted at the end of the event.
RESULTS: Four hundred five responses were received from 3750 visitors (11 % response rate). Nearly half of responses (192/405, 47 · 4 %) considered the misuse/overuse of antibiotics in humans as the main determinant of antimicrobial resistance. The misuse of antibiotics in animal health obtained 16 · 3 % (66/405) responses. However, the lack of quick tests to diagnose infections received 10/405 votes (2 · 47 %), and the lack of effective vaccines received one vote (0 · 25 %).
CONCLUSIONS: The majority of responses ascribed the emergence of drug-resistant infections to the misuse of antibiotics in human and animals. Suboptimal dosing, availability of diagnostics and environmental contamination were considered less influential on the development of antimicrobial resistance. The growing recognition of broader multifaceted drivers of drug resistance by experts is not yet echoed in the public mind
Integrated Ecosystem Assessment: Lake Ontario Water Management
BACKGROUND: Ecosystem management requires organizing, synthesizing, and projecting information at a large scale while simultaneously addressing public interests, dynamic ecological properties, and a continuum of physicochemical conditions. We compared the impacts of seven water level management plans for Lake Ontario on a set of environmental attributes of public relevance. METHODOLOGY AND FINDINGS: Our assessment method was developed with a set of established impact assessment tools (checklists, classifications, matrices, simulations, representative taxa, and performance relations) and the concept of archetypal geomorphic shoreline classes. We considered each environmental attribute and shoreline class in its typical and essential form and predicted how water level change would interact with defining properties. The analysis indicated that about half the shoreline of Lake Ontario is potentially sensitive to water level change with a small portion being highly sensitive. The current water management plan may be best for maintaining the environmental resources. In contrast, a natural water regime plan designed for greatest environmental benefits most often had adverse impacts, impacted most shoreline classes, and the largest portion of the lake coast. Plans that balanced multiple objectives and avoided hydrologic extremes were found to be similar relative to the environment, low on adverse impacts, and had many minor impacts across many shoreline classes. SIGNIFICANCE: The Lake Ontario ecosystem assessment provided information that can inform decisions about water management and the environment. No approach and set of methods will perfectly and unarguably accomplish integrated ecosystem assessment. For managing water levels in Lake Ontario, we found that there are no uniformly good and bad options for environmental conservation. The scientific challenge was selecting a set of tools and practices to present broad, relevant, unbiased, and accessible information to guide decision-making on a set of management options
From arginine methylation to ADMA: A novel mechanism with therapeutic potential in chronic lung diseases
Protein arginine methylation is a novel posttranslational modification regulating a diversity of cellular processes, including protein-protein interaction, signal transduction, or histone function. It has recently been shown to be dysregulated in chronic renal, vascular, and pulmonary diseases, and metabolic products originating from protein arginine methylation have been suggested to serve as biomarkers in cardiovascular and pulmonary diseases
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