1,222 research outputs found

    Effect of cyclosporine on hepatic cytosolic estrogen and androgen receptor levels before and after partial hepatectomy

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    Estrogen and androgen receptors within the liver have been reported to modulate the hepatic regenerative response to partial hepatectomy. Moreover, cyclosporine has several untoward effects that might occur as a consequence of alterations in sex hormone activity. To evaluate these questions the following experiments were performed. Estrogen and androgen receptors in cytosol were quantitated in livers of rats treated with cyclosporine or olive oil vehicle before and after partial hepatectomy or a sham operation. Ornithine decarboxylase activity and thymidine kinase activity were assessed as indices of hepatic regeneration. Preoperative levels of estrogen receptor activity in the hepatic cytosol were significantly greater in rats treated with cyclosporine as compared to vehicle treated controls (P<0.01). In contrast, preoperative levels of androgen receptor activity in the cyclosporine-treated and vehicle-treated animals were similar. Following partial hepatectomy, a reduction in the activity of both sex hormone receptors in the hepatic cytosol was observed and was compatible with results described previously in normal animals. Unexpectedly the preoperative levels of ornithine decarboxylase (P<0.01) and thymidine kinase activity (P<0.01) were significantly greater in the rats treated with cyclosporine as compared to the vehicle treated controls. As expected, ornithine decarboxylase activity (at 6 hr) and thymidine kinase activity (at 24 hr) rose and peaked in response to a partial hepatectomy but were significantly greater (P<0.05) in the rats treated with cyclosporine as compared to the vehicle. These results show that cyclosporine treatment causes an increase in the hepatic content of estrogen receptor activity that is associated with an enhanced potential for a regenerative response. These effects of cyclosporine treatment on the sex hormone receptor levels in liver may explain the mechanisms responsible for some of the untoward effects of treatment with this agent. © 1990 Plenum Publishing Corporation

    Perceived environmental factors related to adults’ leisure-time physical activity : findings from Europe, Australia and the USA

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    This journal suppl. entitled: Be Avtive 2012Session 204B - Environments and physical activity: Adults: paper no. 524INTRODUCTION: A growing body of evidence shows that objective and perceived built environment factors are positively associated with physical activity in adults. However, built environment correlates are behavior-specific and the factors associated with leisure-time physical activity are less understood than those associated with active transportation. Furthermore, most previous studies of associations of built environment attributes with physical activity have been conducted in single countries. Limited within-country variability in environmental attributes and physical activity levels can potentially contribute to an underestimation of the strength of the associations. Therefore, the purpose of this study was to examine the strength, direction and shape of the associations of neighborhood environmental perceptions with recreational walking and leisure-time moderate-to-vigorous physical activity, using pooled data from four study sites (Baltimore [USA], Seattle [USA], Adelaide [Australia] and Ghent [Belgium]) in culturally- and environmentally-diverse countries. Moreover, site- and gender-specificity of the associations were examined. METHODS: Data from the four study sites were pooled. In total, 6,014 adults (20–65 years, 55.7% women) were randomly recruited in high-/low-walkable and high-/low-income neighborhoods in the four sites. All participants completed the Neighborhood Environmental Walkability Scale (environmental perceptions) and the International Physical Activity Questionnaire. General additive mixed models were used to estimate the strength and shape of the associations between environmental perceptions and leisure-time activity (walking and moderate-to-vigorous physical activity). RESULTS: Perceived residential density, aesthetics and reporting few barriers to physical activity in the neighborhood were included in a ‘recreational walking-friendliness’ index. This index was linearly positively related to recreational walking in all study sites except Ghent. No gender-differences were observed. The ‘leisure-time activity friendliness’ index consisted of perceived residential density, proximity to recreation facilities, aesthetics and perceiving few barriers in the neighborhood. This index had a positive linear association with leisure-time moderate-to-vigorous physical activity that was significant in all sites but Ghent. Again, no gender-differences in the associations were found. DISCUSSION: Similar environmental attributes were related to both outcome measures in men and women, but the present findings were clearly site-specific, imposing possible challenges for built environment recommendations. In Europe, interventions to promote leisure-time activity may need to target promotion of existing opportunities rather than built environment improvements. In the USA and Australia, a focus on the factors identified in this study, may be of most relevance for promoting leisure-time physical activity

    Social Interactions vs Revisions, What is important for Promotion in Wikipedia?

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    In epistemic community, people are said to be selected on their knowledge contribution to the project (articles, codes, etc.) However, the socialization process is an important factor for inclusion, sustainability as a contributor, and promotion. Finally, what does matter to be promoted? being a good contributor? being a good animator? knowing the boss? We explore this question looking at the process of election for administrator in the English Wikipedia community. We modeled the candidates according to their revisions and/or social attributes. These attributes are used to construct a predictive model of promotion success, based on the candidates's past behavior, computed thanks to a random forest algorithm. Our model combining knowledge contribution variables and social networking variables successfully explain 78% of the results which is better than the former models. It also helps to refine the criterion for election. If the number of knowledge contributions is the most important element, social interactions come close second to explain the election. But being connected with the future peers (the admins) can make the difference between success and failure, making this epistemic community a very social community too

    Supplementing food for health: Practices amongst French adults aged 60 to 75 years

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    The use of food supplements continues to grow in France, even though it is being discouraged by the main health and medical authorities. The ambiguous definitions surrounding these products make it difficult to measure their consumption. Using a qualitative survey based on interviews (n = 31) of consumers aged 60 to 75 years, this paper explores the ways in which this consumption is increasing. It traces the adoption of food supplementation in this age group back to life-course events, relating to health in particular. Using the practice theory, three forms of supplementation are identified according to the norms, products, sources of medical prescription and purposes at play. The first form is dependent on orthodox medical prescription having been taken; the supplements are prescribed by a doctor and considered by the consumer to be almost like medicinal products. The second form is linked to heterodox 'natural' therapies; products are most often based on plants and considered to be traditional remedies. The third form is related to a heterodox micronutritional approach, claiming to be scientifically advanced; products are identified as food supplements, and their consumption reflected a strategy of prevention, or even health optimisation in ageing. The affinities between these supplementation forms and the individuals' social characteristics are discussed. Results suggest that common consumer categories should be better integrated in the measurement of food supplement consumption

    The effect of different types of hepatic injury on the estrogen and androgen receptor activity of liver

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    Mammalian liver contains receptors for both estrogens and androgens. Hepatic regeneration after partial hepatectomy in male rats is associated with a loss of certain male-specific hepatic characteristics. In this study we investigated the effects of lesser forms of hepatic injury on the levels of estrogen and androgen receptor activity in the liver. Adult male rats were subjected to portacaval shunt, partial portal vein ligation, hepatic artery ligation, or two-thirds partial hepatectomy. Another group of animals was treated with cyclosporine. At the time of sacrifice the livers were removed and used to determine the estrogen and androgen receptor activity in the hepatic cytosol. A significant reduction (p < 0.05) in the hepatic cytosolic androgen receptor activity and a slight increase in the estrogen receptor activity occurred following total portosystemic shunting. Partial ligation of the portal vein, which produces a lesser degree of portosystemic shunting, had no effect on the levels of the estrogen and androgen receptor activity present within hepatic cytosol. Cyclosporine-treated animals had significantly greater (p < 0.01) levels of estrogen receptor activity in the hepatic cytosol compared to vehicle-treated control animals. Levels of estrogen and androgen receptor activity within the hepatic cytosol remained unchanged after ligation of the hepatic artery. The reduction in the cytosolic estrogen and androgen receptor activity in the liver after partial hepatectomy was confirmed. In summary, certain types of hepatic injury are associated with profound changes in the estrogen and androgen receptor content within the liver. © 1989 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

    The Hamburg/ESO R-process Enhanced Star survey (HERES). V. Detailed abundance analysis of the r-process enhanced star HE 2327-5642

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    We report on a detailed abundance analysis of the strongly r-process enhanced giant star, HE 2327-5642 ([Fe/H] = -2.78, [r/Fe] = +0.99). Determination of stellar parameters and element abundances was based on analysis of high-quality VLT/UVES spectra. The surface gravity was calculated from the NLTE ionization balance between Fe I and Fe II, and Ca I and Ca II. Accurate abundances for a total of 40 elements and for 23 neutron-capture elements beyond Sr and up to Th were determined. The heavy element abundance pattern of HE 2327-5642 is in excellent agreement with those previously derived for other strongly r-process enhanced stars. Elements in the range from Ba to Hf match the scaled Solar r-process pattern very well. No firm conclusion can be drawn with respect to a relationship between the fisrt neutron-capture peak elements, Sr to Pd, in HE 2327-5642 and the Solar r-process, due to the uncertainty of the latter. A clear distinction in Sr/Eu abundance ratios was found between the halo stars with different europium enhancement. The strongly r-process enhanced stars reveal a low Sr/Eu abundance ratio at [Sr/Eu] = -0.92+-0.13, while the stars with 0 < [Eu/Fe] < 1 and [Eu/Fe] < 0 have 0.36 dex and 0.93 dex larger Sr/Eu values, respectively. Radioactive dating for HE 2327-5642 with the observed thorium and rare-earth element abundance pairs results in an average age of 13.3 Gyr, when based on the high-entropy wind calculations, and 5.9 Gyr, when using the Solar r-residuals. HE 2327-5642 is suspected to be radial-velocity variable based on our high-resolution spectra, covering ~4.3 years.Comment: 16 pages, 12 figures, accepted to A&

    Stellar Rotation in Young Clusters. II. Evolution of Stellar Rotation and Surface Helium Abundance

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    We derive the effective temperatures and gravities of 461 OB stars in 19 young clusters by fitting the H-gamma profile in their spectra. We use synthetic model profiles for rotating stars to develop a method to estimate the polar gravity for these stars, which we argue is a useful indicator of their evolutionary status. We combine these results with projected rotational velocity measurements obtained in a previous paper on these same open clusters. We find that the more massive B-stars experience a spin down as predicted by the theories for the evolution of rotating stars. Furthermore, we find that the members of binary stars also experience a marked spin down with advanced evolutionary state due to tidal interactions. We also derive non-LTE-corrected helium abundances for most of the sample by fitting the He I 4026, 4387, 4471 lines. A large number of helium peculiar stars are found among cooler stars with Teff < 23000 K. The analysis of the high mass stars (8.5 solar masses < M < 16 solar masses) shows that the helium enrichment process progresses through the main sequence (MS) phase and is greater among the faster rotators. This discovery supports the theoretical claim that rotationally induced internal mixing is the main cause of surface chemical anomalies that appear during the MS phase. The lower mass stars appear to have slower rotation rates among the low gravity objects, and they have a large proportion of helium peculiar stars. We suggest that both properties are due to their youth. The low gravity stars are probably pre-main sequence objects that will spin up as they contract. These young objects very likely host a remnant magnetic field from their natal cloud, and these strong fields sculpt out surface regions with unusual chemical abundances.Comment: 50 pages 18 figures, accepted by Ap

    Community led active schools programme (CLASP) exploring the implementation of health interventions in primary schools: headteachers’ perspectives

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    Background: Schools are repeatedly utilised as a key setting for health interventions. However, the translation of effective research findings to the school setting can be problematic. In order to improve effective translation of future interventions, it is imperative key challenges and facilitators of implementing health interventions be understood from a school's perspective. Methods: Nineteen semi-structured interviews were conducted in primary schools (headteachers n = 16, deputy headteacher n = 1, healthy school co-ordinator n = 2). Interviews were transcribed verbatim and analysed using thematic analysis. Results: The main challenges for schools in implementing health interventions were; government-led academic priorities, initiative overload, low autonomy for schools, lack of staff support, lack of facilities and resources, litigation risk and parental engagement. Recommendations to increase the application of interventions into the school setting included; better planning and organisation, greater collaboration with schools and external partners and elements addressing sustainability. Child-centred and cross-curricular approaches, inclusive whole school approaches and assurances to be supportive of the school ethos were also favoured for consideration. Conclusions: This work explores schools' perspectives regarding the implementation of health interventions and utilises these thoughts to create guidelines for developing future school-based interventions. Recommendations include the need to account for variability between school environments, staff and pupils. Interventions with an element of adaptability were preferred over the delivery of blanket fixed interventions. Involving schools in the developmental stage would add useful insights to ensure the interventions can be tailored to best suit each individual schools' needs and improve implementation.11 page(s

    Autism as a disorder of neural information processing: directions for research and targets for therapy

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    The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
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