51 research outputs found

    Significance of Input Correlations in Striatal Function

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    The striatum is the main input station of the basal ganglia and is strongly associated with motor and cognitive functions. Anatomical evidence suggests that individual striatal neurons are unlikely to share their inputs from the cortex. Using a biologically realistic large-scale network model of striatum and cortico-striatal projections, we provide a functional interpretation of the special anatomical structure of these projections. Specifically, we show that weak pairwise correlation within the pool of inputs to individual striatal neurons enhances the saliency of signal representation in the striatum. By contrast, correlations among the input pools of different striatal neurons render the signal representation less distinct from background activity. We suggest that for the network architecture of the striatum, there is a preferred cortico-striatal input configuration for optimal signal representation. It is further enhanced by the low-rate asynchronous background activity in striatum, supported by the balance between feedforward and feedback inhibitions in the striatal network. Thus, an appropriate combination of rates and correlations in the striatal input sets the stage for action selection presumably implemented in the basal ganglia

    Time spent on work-related activities, social activities and time pressure as intermediary determinants of health disparities among elderly women and men in 5 European countries: a structural equation model

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    Background Psychosocial factors shape the health of older adults through complex inter-relating pathways. Besides socioeconomic factors, time use activities may explain gender inequality in self-reported health. This study investigated the role of work-related and social time use activities as determinants of health in old age. Specifically, we analysed whether the impact of stress in terms of time pressure on health mediated the relationship between work-related time use activities (i.e. housework and paid work) on self-reported health. Methods We applied structural equation models and a maximum-likelihood function to estimate the direct and indirect effects of psychosocial factors on health using pooled data from the Multinational Time Use Study on 11,168 men and 14,295 women aged 65+ from Italy, Spain, UK, France and the Netherlands. Results The fit indices for the conceptual model indicated an acceptable fit for both men and women. The results showed that socioeconomic status (SES), demographic factors, stress and work-related time use activities after retirement had a significant direct influence on self-reported health among the elderly, but the magnitude of the effects varied by gender. Social activities had a positive impact on self-reported health but had no significant impact on stress among older men and women. The indirect standardized effects of work-related activities on self-reported health was statistically significant for housework (ÎČ = − 0.006; P  0.05 among women), which implied that the paths from paid work and housework on self-reported health via stress (mediator) was very weak because their indirect effects were close to zero. Conclusions Our findings suggest that although stress in terms of time pressure has a direct negative effect on health, it does not indirectly influence the positive effects of work-related time use activities on self-reported health among elderly men and women. The results support the time availability hypothesis that the elderly may not have the same time pressure as younger adults after retirement

    Imaging biomarker roadmap for cancer studies.

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    Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution

    In vitro α-glucosidase inhibitory activity of phenolic constituents from aerial parts of Polygonum hyrcanicum

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    <p>Abstract</p> <p>Background and the purpose of the study</p> <p>The early stage of diabetes mellitus type 2 is associated with postprandial hyperglycemia. Hyperglycemia is believed to increase the production of free radicals and reactive oxygen species, leading to oxidative tissue damage. In an effort of identifying herbal drugs which may become useful in the prevention or mitigation of diabetes, biochemical activities of <it>Polygonum hyrcanicum</it> and its constituents were studied.</p> <p>Methods</p> <p>Hexane, ethylacetate and methanol extracts of <it>P. hyrcanicum</it> were tested for α-glucosidase inhibitory, antioxidant and radical scavenging properties. Active constituents were isolated and identified from the methanolic extract in an activity guided approach.</p> <p>Results</p> <p>A methanolic extract from flowering aerial parts of the plant showed notable α-glucosidase inhibitory activity (IC<sub>50</sub> = 15 ÎŒg/ml). Thirteen phenolic compounds involving a cinnamoylphenethyl amide, two flavans, and ten flavonols and flavonol 3-O-glycosides were subsequently isolated from the extract. All constituents showed inhibitory activities while compounds 3, 8 and 11 (IC<sub>50</sub> = 0.3, 1.0, and 0.6 ÎŒM, respectively) were the most potent ones. The methanol extract also showed antioxidant activities in DPPH (IC<sub>50</sub> = 76 ÎŒg/ml) and FRAP assays (1.4 mmol ferrous ion equivalent/g extract). A total phenol content of 130 mg/g of the extract was determined by Folin-Ciocalteu reagent.</p> <p>Conclusion</p> <p>This study shows that <it>P. hyrcanicum</it> contains phenolic compounds with in vitro activity that can be useful in the context of preventing or mitigating cellular damages linked to diabetic conditions.</p

    Plasma oxytocin concentration during pregnancy is associated with development of postpartum depression

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    Postpartum depression (PPD) affects up to 19% of all women after parturition. The non-apeptide oxytocin (OXT) is involved in adjustment to pregnancy, maternal behavior, and bonding. Our aim was to examine the possible association between plasma OXT during pregnancy and the development of PPD symptoms. A total of 74 healthy, pregnant women were included in this prospective study. During the third trimester of pregnancy and within 2 weeks after parturition, PPD symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS). Blood samples for plasma OXT assessment were collected in the third trimester. Following the literature, participants with postpartum EPDS scores of 10 or more were regarded as being at risk for PPD development (rPPD group). In a logistic regression analysis, plasma OXT was included as a potential predictor for being at risk for PPD. Results were controlled for prepartal EPDS score, sociodemographic and birth-outcome variables. Plasma OXT concentration in mid-pregnancy significantly predicted PPD symptoms at 2 weeks postpartum. Compared with the no-risk-for-PPD group, the rPPD group was characterized by lower plasma OXT concentrations. To our knowledge, this is the first study to show an association between prepartal plasma OXT concentration and postpartal symptoms of PPD in humans. Assuming a causal relationship, enhancing OXT release during pregnancy could serve as a potential target in prepartum PPD prevention, and help to minimize adverse effects of PPD on the mother-child relationship

    The attitude of european consumers towards the country of origin of products: the influence of "Made In" in the purchase intention

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    This study approaches the theme of country of origin as a criterion for choosing products. The research focused on Portuguese products, using a sample of 567 consumers from Germany, France, Spain, and United Kingdom, which are Portugal’s main importers. The dimensions “country image”, “perception regarding the country’s products”, “perception towards consumers of the products”, as well as the “purchase intention” of these products, were analyzed. The first two dimensions presented positive relationships with the purchase intention, but this did not happen for the third dimension. Based on the results of the study, recommendations for professionals were elaborated and suggestions for future research outlined.691D-6753-BE59 | Manuel JosĂ© Serra da FonsecaN/

    Stent versus gastrojejunostomy for the palliation of gastric outlet obstruction: A systematic review

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    Background: Gastrojejunostomy (GJJ) is the most commonly used palliative treatment modality for malignant gastric outlet obstruction. Recently, stent placement has been introduced as an alternative treatment. We reviewed the available literature on stent placement and GJJ for gastric outlet obstruction, with regard to medical effects and costs. Methods: A systematic review of the literature was performed by searching PubMed for the period January 1996 and January 2006. A total of 44 publications on GJJ and stents was identified and reported results on medical effects and costs were pooled and evaluated. Results from randomized and comparative studies were used for calculating odds ratios (OR) to compare differences between the two treatment modalities. Results: In 2 randomized trials, stent placement was compared with GJJ (with 27 and 18 patients in each trial). In 6 comparative studies, stent placement was compared with GJJ. Thirty-six series evaluated either stent placement or GJJ. A total of 1046 patients received a duodenal stent and 297 patients underwent GJJ. No differences between stent placement and gastrojejunostomy were found in technical success (96% vs. 100%), early and late major complications 7% vs. 6% and 18% vs. 17%, respectively) and persisting symptoms (8% vs. 9%). Initial clinical success was higher after stent placement (89% vs. 72%). Minor complications were less frequently seen after stent placement in the patient series (9% vs. 33%), however the pooled analysis showed no differences (OR: 0.75, p = 0.8). Recurrent obstructive symptoms were more common after stent placement (18% vs. 1%). Hospital stay was prolonged after GJJ compared to stent placement (13 days vs. 7 days). The mean survival was 105 days after stent placement and 164 days after GJJ. Conclusion: These results suggest that stent placement may be associated with more favorable results in patients with a relatively short life expectancy, while GJJ is preferable in patients with a more prolonged prognosis. The paucity of evidence from large randomized trials may however have influenced the results and therefore a trial of sufficient size is needed to determine which palliative treatment modality is optimal in (sub)groups of patients with malignant gastric outlet obstruc
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