195 research outputs found

    Left hepatic trisegmentectomy

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    Left hepatic trisegmentectomy was successfully performed upon four patients in whom the true left lobe of the liver and all, or part, of the anterior segment of the right lobe of the liver were removed in continuity. Three of the patients had carcinoma of the liver, and the fourth patient had a hemangioma and arteriovenous malformation. This procedure, which has not been described before, should allow subtotal hepatic resection to be performed upon some patients who have lesions that have been classified as inoperable, in the past

    Physiological beta-catenin signaling controls self-renewal networks and generation of stem-like cells from nasopharyngeal carcinoma

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    BACKGROUND: A few reports suggested that low levels of Wnt signaling might drive cell reprogramming, but these studies could not establish a clear relationship between Wnt signaling and self-renewal networks. There are ongoing debates as to whether and how the Wnt/beta-catenin signaling is involved in the control of pluripotency gene networks. Additionally, whether physiological beta-catenin signaling generates stem-like cells through interactions with other pathways is as yet unclear. The nasopharyngeal carcinoma HONE1 cells have low expression of beta-catenin and wild-type expression of p53, which provided a possibility to study regulatory mechanism of stemness networks induced by physiological levels of Wnt signaling in these cells. RESULTS: Introduction of increased beta-catenin signaling, haploid expression of beta-catenin under control by its natural regulators in transferred chromosome 3, resulted in activation of Wnt/beta-catenin networks and dedifferentiation in HONE1 hybrid cell lines, but not in esophageal carcinoma SLMT1 hybrid cells that had high levels of endogenous beta-catenin expression. HONE1 hybrid cells displayed stem cell-like properties, including enhancement of CD24(+) and CD44(+) populations and generation of spheres that were not observed in parental HONE1 cells. Signaling cascades were detected in HONE1 hybrid cells, including activation of p53- and RB1-mediated tumor suppressor pathways, up-regulation of Nanog-, Oct4-, Sox2-, and Klf4-mediated pluripotency networks, and altered E-cadherin expression in both in vitro and in vivo assays. qPCR array analyses further revealed interactions of physiological Wnt/beta-catenin signaling with other pathways such as epithelial-mesenchymal transition, TGF-beta, Activin, BMPR, FGFR2, and LIFR- and IL6ST-mediated cell self-renewal networks. Using beta-catenin shRNA inhibitory assays, a dominant role for beta-catenin in these cellular network activities was observed. The expression of cell surface markers such as CD9, CD24, CD44, CD90, and CD133 in generated spheres was progressively up-regulated compared to HONE1 hybrid cells. Thirty-four up-regulated components of the Wnt pathway were identified in these spheres. CONCLUSIONS: Wnt/beta-catenin signaling regulates self-renewal networks and plays a central role in the control of pluripotency genes, tumor suppressive pathways and expression of cancer stem cell markers. This current study provides a novel platform to investigate the interaction of physiological Wnt/beta-catenin signaling with stemness transition networks.published_or_final_versio

    Autonomy support, basic need satisfaction and the optimal functioning of adult male and female sport participants: A test of basic needs theory

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    Grounded in Basic Needs Theory (BNT; Ryan and Deci, American Psychologist, 55, 68–78, 2000a), the present study aimed to: (a) test a theoretically-based model of coach autonomy support, motivational processes and well-/ill being among a sample of adult sport participants, (b) discern which basic psychological need(s) mediate the link between autonomy support and well-/ill-being, and (c) explore gender invariance in the hypothesized model. Five hundred and thirty nine participants (Male = 271;Female = 268; Mage = 22.75) completed a multi-section questionnaire tapping the targeted variables. Structural Equation Modeling (SEM) analysis revealed that coach autonomy support predicted participants’ basic need satisfaction for autonomy, competence and relatedness. In turn, basic need satisfaction predicted greater subjective vitality when engaged in sport. Participants with low levels of autonomy were more susceptible to feeling emotionally and physically exhausted from their sport investment. Autonomy and competence partially mediated the path from autonomy support to subjective vitality. Lastly, the results supported partial invariance of the model with respect to gender

    Assessing bird exclusion effects in a wetland crossed by a railway (Sado estuary, Portugal)

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    L. Borda-de-Água et al. (eds.), Railway Ecology, Chapter 11, p. 179-195Linear transportation infrastructures may displace wildlife from nearby areas that otherwise would provide adequate habitat conditions. This exclusion effect has been documented in roads, but much less is known about railways. Here we evaluated the potential exclusion effect on birds of a railway crossing a wetland of international importance (Sado Estuary, Portugal). We selected 22 sectors representative of locally available wetland habitats (salt pans, rice paddy fields, and intertidal mudflats); of each, half were located either close to (0–500 m) or far from (500–1500 m) the railway line. Water birds were counted in each sector between December 2012 and October 2015, during two months per season (spring, summer, winter, and autumn) and year, at both low and high tide. We recorded 46 species, of which the most abundant (>70% of individuals) were black-headed gull, greater flamingo, northern shoveler, black-tailed godwit, and lesser black-backed gull. Peak abundances were found in autumn and winter. There was no significant variation between sectors close to and far from the railway in species richness, total abundance, and abundance of the most common species. Some species tended to be most abundant either close to or far from the railway albeit not significantly so but this often varied across the tidal and annual cycles. Overall, our study did not find noticeable exclusion effects of this railway on wetland birds, with spatial variation in abundances probably reflecting habitat selection and daily movement patterns. Information is needed on other study systems to assess the generality of our findingsinfo:eu-repo/semantics/publishedVersio

    Human Papillomavirus Type 16 Entry: Retrograde Cell Surface Transport along Actin-Rich Protrusions

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    The lateral mobility of individual, incoming human papillomavirus type 16 pseudoviruses (PsV) bound to live HeLa cells was studied by single particle tracking using fluorescence video microscopy. The trajectories were computationally analyzed in terms of diffusion rate and mode of motion as described by the moment scaling spectrum. Four distinct modes of mobility were seen: confined movement in small zones (30–60 nm in diameter), confined movement with a slow drift, fast random motion with transient confinement, and linear, directed movement for long distances. The directed movement was most prominent on actin-rich cell protrusions such as filopodia or retraction fibres, where the rate was similar to that measured for actin retrograde flow. It was, moreover, sensitive to perturbants of actin retrograde flow such as cytochalasin D, jasplakinolide, and blebbistatin. We found that transport along actin protrusions significantly enhanced HPV-16 infection in sparse tissue culture, cells suggesting a role for in vivo infection of basal keratinocytes during wound healing

    Maternal iodine status in a multi‐ethnic UK birth cohort: Associations with child cognitive and educational development

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    Background: Maternal iodine requirements increase during pregnancy to supply thyroid hormones critical for fetal neurodevelopment. Iodine insufficiency may result in poorer cognitive or child educational outcomes but current evidence is sparse and inconsistent. Objectives: To quantify the association between maternal iodine status and child educational outcomes. Methods: Urinary iodine concentrations (UIC) and iodine/creatinine ratios (I:Cr) were measured in 6971 mothers at 26‐28 weeks' gestation participating in the Born in Bradford cohort. Maternal iodine status was examined in relation to child school achievement (early years foundation stage (EYFS), phonics, and Key Stage 1 (KS1)), other learning outcomes, social and behavioural difficulties, and sensorimotor control in 5745 children aged 4‐7 years. Results: Median (interquartile range) UIC was 76 µg/L (46, 120), and I:Cr was 83 µg/g (59, 121). Overall, there was no strong or consistent evidence to support associations between UIC or I:Cr and neurodevelopmental outcomes. For instance, predicted EYFS and phonics scores (primary outcomes) at the 25th vs 75th I:Cr percentiles (99% confidence intervals) were similar, with no evidence of associations: EYFS scores were 32 (99% CI 31, 33) and 33 (99% CI 32, 34), and phonics scores were 34 (99% CI 33, 35) and 35 (99% CI 34, 36), respectively. Conclusions: In the largest single study of its kind, there was little evidence of detrimental neurodevelopmental outcomes in children born to pregnant women with iodine insufficiency as defined by World Health Organization–outlined thresholds. Alternative functional biomarkers for iodine status in pregnancy and focused assessment of other health outcomes may provide additional insight

    A Generic System for the Expression and Purification of Soluble and Stable Influenza Neuraminidase

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    The influenza surface glycoprotein neuraminidase (NA) is essential for the efficient spread of the virus. Antiviral drugs such as Tamiflu (oseltamivir) and Relenza (zanamivir) that inhibit NA enzyme activity have been shown to be effective in the treatment of influenza infections. The recent ‘swine flu’ pandemic and world-wide emergence of Tamiflu-resistant seasonal human influenza A(H1N1) H274Y have highlighted the need for the ongoing development of new anti-virals, efficient production of vaccine proteins and novel diagnostic tools. Each of these goals could benefit from the production of large quantities of highly pure and stable NA. This publication describes a generic expression system for NAs in a baculovirus Expression Vector System (BEVS) that is capable of expressing milligram amounts of recombinant NA. To construct NAs with increased stability, the natural influenza NA stalk was replaced by two different artificial tetramerization domains that drive the formation of catalytically active NA homotetramers: GCN4-pLI from yeast or the Tetrabrachion tetramerization domain from Staphylothermus marinus. Both recombinant NAs are secreted as FLAG-tagged proteins to allow for rapid and simple purification. The Tetrabrachion-based NA showed good solubility, increased stability and biochemical properties closer to the original viral NA than the GCN4-pLI based construct. The expressed quantities and high quality of the purified recombinant NA suggest that this expression system is capable of producing recombinant NA for a broad range of applications including high-throughput drug screening, protein crystallisation, or vaccine development

    Multi-Level Interactions between the Nuclear Receptor TRα1 and the WNT Effectors β-Catenin/Tcf4 in the Intestinal Epithelium

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    Intestinal homeostasis results from complex cross-regulation of signaling pathways; their alteration induces intestinal tumorigenesis. Previously, we found that the thyroid hormone nuclear receptor TRα1 activates and synergizes with the WNT pathway, inducing crypt cell proliferation and promoting tumorigenesis. Here, we investigated the mechanisms and implications of the cross-regulation between these two pathways in gut tumorigenesis in vivo and in vitro. We analyzed TRα1 and WNT target gene expression in healthy mucosae and tumors from mice overexpressing TRα1 in the intestinal epithelium in a WNT-activated genetic background (vil-TRα1/Apc mice). Interestingly, increased levels of β-catenin/Tcf4 complex in tumors from vil-TRα1/Apc mice blocked TRα1 transcriptional activity. This observation was confirmed in Caco2 cells, in which TRα1 functionality on a luciferase reporter-assay was reduced by the overexpression of β-catenin/Tcf4. Moreover, TRα1 physically interacted with β-catenin/Tcf4 in the nuclei of these cells. Using molecular approaches, we demonstrated that the binding of TRα1 to its DNA target sequences within the tumors was impaired, while it was newly recruited to WNT target genes. In conclusion, our observations strongly suggest that increased β-catenin/Tcf4 levels i) correlated with reduced TRα1 transcriptional activity on its target genes and, ii) were likely responsible for the shift of TRα1 binding on WNT targets. Together, these data suggest a novel mechanism for the tumor-promoting activity of the TRα1 nuclear receptor
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