761 research outputs found

    Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

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    Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

    Coordinated optimization of visual cortical maps (II) Numerical studies

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    It is an attractive hypothesis that the spatial structure of visual cortical architecture can be explained by the coordinated optimization of multiple visual cortical maps representing orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we defined a class of analytically tractable coordinated optimization models and solved representative examples in which a spatially complex organization of the orientation preference map is induced by inter-map interactions. We found that attractor solutions near symmetry breaking threshold predict a highly ordered map layout and require a substantial OD bias for OP pinwheel stabilization. Here we examine in numerical simulations whether such models exhibit biologically more realistic spatially irregular solutions at a finite distance from threshold and when transients towards attractor states are considered. We also examine whether model behavior qualitatively changes when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. Our numerical results support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the spatially irregular architecture of the visual cortex. We discuss several alternative scenarios and additional factors that may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with arXiv:1102.335

    Psychiatric and medical admissions observed among elderly patients with new-onset epilepsy

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    <p>Abstract</p> <p>Background</p> <p>Inpatient utilization associated with incidence of geriatric new-onset epilepsy has not been characterized in any large study, despite recognized high levels of risk factors (comorbidity).</p> <p>Methods</p> <p>Retrospective study using administrative data (Oct '01-Sep '05) from the Veterans Health Administration from a nationwide sample of 824,483 patients over age 66 in the retrospective observational Treatment In Geriatric Epilepsy Research (TIGER) study. Psychiatric and medical hospital admissions were analyzed as a function of patient demographics, comorbid psychiatric, neurological, and other medical conditions, and new-onset epilepsy.</p> <p>Results</p> <p>Elderly patients experienced a 15% hospitalization rate in FY00 overall, but the subset of new-onset epilepsy patients (n = 1,610) had a 52% hospitalization rate. New-onset epilepsy was associated with three-fold increased relative odds of psychiatric admission and nearly five-fold increased relative odds of medical admission. Among new-onset epilepsy patients, alcohol dependence was most strongly associated with psychiatric admission during the first year after epilepsy onset (odds ratio = 5.2; 95% confidence interval 2.6-10.0), while for medical admissions the strongest factor was myocardial infarction (odds ratio = 4.7; 95% confidence interval 2.7-8.3).</p> <p>Conclusion</p> <p>From the patient point of view, new-onset epilepsy was associated with an increased risk of medical admission as well as of psychiatric admission. From an analytic perspective, omitting epilepsy and other neurological conditions may lead to overestimation of the risk of admission attributable solely to psychiatric conditions. Finally, from a health systems perspective, the emerging picture of the epilepsy patient with considerable comorbidity and demand for healthcare resources may merit development of practice guidelines to improve coordinated delivery of care.</p

    Study of trunk asymmetry in normal children and adolescents

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    The scoliometer readings in both standing and sitting position of 2071 children and adolescents (1099 boys and 972 girls) aged from 5 to 18 years old were studied. The angle of trunk rotation (ATR) was measured, in order to quantify the existing trunk asymmetry. Children and adolescents were divided in two groups according to the severity of trunk asymmetry. In the first group asymmetry was 1 to 6 degrees and in the second group was 7 or more degrees. Radiographic and leg length inequality evaluation were also performed in a number of children. The mean frequency of symmetric (ATR = 0 degrees) boys and girls was 67.06% and 65.01% for the standing screening position and 76.5% and 75.1% for the sitting position, respectively. The mean difference of frequency of asymmetry (ATR > 0 degrees) at standing minus sitting forward bending position for boys and girls was 10.22% and 9.37%, respectively. The mean frequency of asymmetry of 7 or more degrees was 3.23% for boys and 3.92% for girls at the standing forward bending position and 1.62% and 2.21% at the sitting, respectively. Girls are found to express higher frequency of asymmetry than boys. Right trunk asymmetry was more common than left. The sitting position is the preferred screening position for examining the rib or loin hump during school screening as it demonstrates the best correlation with the spinal deformity exposing the real trunk asymmetry

    Spatio-temporal Models of Lymphangiogenesis in Wound Healing

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    Several studies suggest that one possible cause of impaired wound healing is failed or insufficient lymphangiogenesis, that is the formation of new lymphatic capillaries. Although many mathematical models have been developed to describe the formation of blood capillaries (angiogenesis), very few have been proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a markedly different process from angiogenesis, occurring at different times and in response to different chemical stimuli. Two main hypotheses have been proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic endothelial cells first pool in the wound region following the lymph flow and then, once sufficiently populated, start to form a network. Here we present two PDE models describing lymphangiogenesis according to these two different hypotheses. Further, we include the effect of advection due to interstitial flow and lymph flow coming from open capillaries. The variables represent different cell densities and growth factor concentrations, and where possible the parameters are estimated from biological data. The models are then solved numerically and the results are compared with the available biological literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total
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