25 research outputs found

    Poorly differentiated and anaplastic thyroid carcinomas: chromosomal and oligo-array profile of five new cell lines

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    Information on gene alterations associated to poorly differentiated (PDTC) and anaplastic thyroid carcinomas (ATC) is scarce. Using human cancer cell lines as a tool for gene discovery, we performed a cytogenetic and oligo-array analysis in five new cell lines derived from two PDTC and three ATC. In PDTC we evidenced, as important, the involvement of the MAPK/ERK kinase pathway, and downregulation of a group of suppressor genes that include E-cadherin. In ATC, downregulation of a specific group of oncosuppressor genes was also observed. Our ATC cell lines presented chromosomal markers of gene amplification, and we were able to identify for the first time the nature of the involved amplicon target genes. We found that the main molecular differences between the two cell line types were related to signal transduction pathways, cell adhesion and motility process. TaqMan experiments performed for five amplicon target genes and for two genes, which allowed a clear distinction between ATC and PDTC: CDH13 and PLAU corroborated array results, not only in the cell lines, but also in an additional set of primary 14 PDTC and three ATC. We suggest that our findings may represent new tools for the development of more effective therapies to the hitherto untreatable ATC

    Metabolic Rift or Metabolic Shift? Dialectics, Nature, and the World-Historical Method

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    Abstract In the flowering of Red-Green Thought over the past two decades, metabolic rift thinking is surely one of its most colorful varieties. The metabolic rift has captured the imagination of critical environmental scholars, becoming a shorthand for capitalism’s troubled relations in the web of life. This article pursues an entwined critique and reconstruction: of metabolic rift thinking and the possibilities for a post-Cartesian perspective on historical change, the world-ecology conversation. Far from dismissing metabolic rift thinking, my intention is to affirm its dialectical core. At stake is not merely the mode of explanation within environmental sociology. The impasse of metabolic rift thinking is suggestive of wider problems across the environmental social sciences, now confronted by a double challenge. One of course is the widespread—and reasonable—sense of urgency to evolve modes of thought appropriate to an era of deepening biospheric instability. The second is the widely recognized—but inadequately internalized—understanding that humans are part of nature

    Geostatistical analysis of soil properties in a secondary tropical dry forest, St. Lucia, West Indies

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    Spatial variability of soil properties directly influences forest growth. However, spatial variation in soil properties has not been studied within tropical dry forests. As such, it is unclear whether soil properties, like moisture and N availability, display spatial variation at scales similar to that of other ecosystems. To gain insight into this variation, we established a 56 Ă— 56 m sampling grid in tropical dry forest on the Caribbean island of St. Lucia. Samples collected at 4-m intervals were analyzed for forest floor mass, soil texture, pH, organic C, net N mineralization, net nitrification and available P. Geostatistical procedures were used to determine spatial autocorrelation of the aforementioned properties and processes. Semivariogram parameters were used in a block kriging procedure to produce spatial maps of soil properties. At the scale of our study, most soil properties exhibited spatial autocorrelation at distances of 24 m or less. Varying degrees of similarity were found between patterns of forest floor mass, organic C, net N mineralization, net nitrification and available P. No similarity was found between soil texture or pH and other properties. Fine-scale spatial patterns of net N mineralization and net nitrification are likely driven by overstory litter inputs, rather than variation in soil texture and water availability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43463/1/11104_2004_Article_BF00033939.pd

    Degradation of Leaf Litter Phenolics by Aquatic and Terrestrial Isopods

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    To investigate species-specific decomposition rates of litter from native (Quercus faginea) and introduced (Eucalyptus globulus) tree species in Portugal, we monitored changes in the phenolic signature of leaf litter during decomposition as mediated by an aquatic, Proasellus coxalis (Isopoda: Asellota), and two terrestrial, Porcellio dispar and Eluma caelatum (Isopoda: Oniscidea), detritivores. Although the litter of Eucalyptus and Quercus did not differ in overall protein precipitation capacity, we detected differences in terms of contents of particular phenolic compounds and phenol oxidation products. Accordingly, we observed food-specific consumption rates in Proasellus, but not in the terrestrial isopods. Proasellus digested Eucalyptus at significantly higher rates than Quercus, whereas the opposite was the case for Eluma, and Porcellio digested both litter types equally well. Despite slight differences in detail, effects of Proasellus on changes in the signature of litter phenolics were similar for both litter types, whereas terrestrial isopods—Porcellio and Eluma, although they differed from each other—digestively degraded phenolic compounds in Eucalyptus and Quercus litter, respectively, in different ways. Overall, however, degradation of litter phenolics was similarly effective on both litter types. From these data, we conclude that decomposition of Eucalyptus litter does not proceed more slowly than of litter from native Portuguese trees

    Proceedings of the Oxygen Homeostasis/Hypoxia Meeting

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    © 2004 American Association for Cancer ResearchThe first Oxygen Homeostasis/Hypoxia Meeting was held on February 12, 2003, at the Sheraton National Hotel, Washington, D.C. The meeting was hosted by Drs. S. Percy Ivy and Giovanni Melillo of the National Cancer Institute, NIH. The purpose of the meeting was to stimulate collaborations among the participants who are engaged in different areas of hypoxia research and application, Including basic research on hypoxia, and its induction and consequences; the development of drugs targeting hypoxia and factors involved in pathways leading to (or controlled by) hypoxia; and the development and application of hypoxia imaging techniques and reagents.Bennett Kaufman, Orit Scharf, Jeffrey Arbeit, Margaret Ashcroft, J. Martin Brown, Richard K. Bruick, J. Donald Chapman, Sydney M. Evans, Amato J. Giaccia, Adrian L. Harris, Eric Huang, Randall Johnson, William Kaelin, Jr., Cameron J. Koch, Patrick Maxwell, James Mitchell, Len Neckers, Garth Powis, Joseph Rajendran, Gregg L. Semenza, Jonathan Simons, Erik Storkebaum, Michael J. Welch, Murray Whitelaw, Giovanni Melillo and S. Percy Iv
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