22 resultados para virtue

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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The attribution of responsibility in world society is increasingly a field of contestation. On the one hand, the perception of causal and moral links reaching far in space and time are ever more explicitly pronounced; on the other hand, the very complexity of these links often engenders a fragmentation of responsibility both in law (Veitch 2007) as well as in moral commitment. Moreover, those institutions of legal responsibility attempting to reflect some of these interrelations are often criticised as insufficient by those who follow alternative narratives of causation and moral community. Current institutions of responsibility in law appear to abstract from what could be called enabling contexts; they perform their cuts in the chains of enabling interactions at very brief intervals (Strathern 2001). The result is often “organised irresponsibility” (Veitch 2007; Beck 1996), producing appeals to a global community of concern in time and space without corresponding obligatory commitments. This talk explores alternative conceptualisations of responsibility, and enquires into their notion of the person, their temporal and socio-spatial dimensions, and their notion of liability.

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Metzincins and functionally related genes play important roles in extracellular matrix remodeling both in healthy and fibrotic conditions. We recently presented a transcriptomic classifier consisting of 19 metzincins and related genes (MARGS) discriminating biopsies from renal transplant patients with or without interstitial fibrosis/tubular atrophy (IF/TA) by virtue of gene expression measurement (Roedder et al., Am J Transplant 9:517-526, 2009). Here we demonstrate that the same algorithm has diagnostic value in non-transplant solid organ fibrosis. We used publically available microarray datasets of 325 human heart, liver, lung, kidney cortex, and pancreas microarray samples (265 with fibrosis, 60 healthy controls). Expression of nine commonly differentially expressed genes was confirmed by TaqMan low-density arrays (Applied Biosystems, USA) in 50 independent archival tissue specimens with matched histological diagnoses to microarray patients. In separate and in combined, integrated microarray data analyses of five datasets with 325 samples, the previously published MARGS classifier for renal post-transplant IF/TA had a mean AUC of 87% and 82%, respectively. These data demonstrate that the MARGS gene panel classifier not only discriminates IF/TA from normal renal transplant tissue, but also classifies solid organ fibrotic conditions of human pancreas, liver, heart, kidney, and lung tissue samples with high specificity and accuracy, suggesting that the MARGS classifier is a cross-platform, cross-organ classifier of fibrotic conditions of different etiologies when compared to normal tissue.

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Meprin-α is a metalloprotease overexpressed in cancer cells, leading to the accumulation of this protease in a subset of colorectal tumors. The impact of increased meprin-α levels on tumor progression is not known. We investigated the effect of this protease on cell migration and angiogenesis in vitro and studied the expression of meprin-α mRNA, protein and proteolytic activity in primary tumors at progressive stages and in liver metastases of patients with colorectal cancer, as well as inhibitory activity towards meprin-α in sera of cancer patient as compared to healthy controls. We found that the hepatocyte growth factor (HGF)-induced migratory response of meprin-transfected epithelial cells was increased compared to wild-type cells in the presence of plasminogen, and that the angiogenic response in organ-cultured rat aortic explants was enhanced in the presence of exogenous human meprin-α. In patients, meprin-α mRNA was expressed in colonic adenomas, primary tumors UICC (International Union Against Cancer) stage I, II, III and IV, as well as in liver metastases. In contrast, the corresponding protein accumulated only in primary tumors and liver metastases, but not in adenomas. However, liver metastases lacked meprin-α activity despite increased expression of the corresponding protein, which correlated with inefficient zymogen activation. Sera from cancer patients exhibited reduced meprin-α inhibition compared to healthy controls. In conclusion, meprin-α activity is regulated differently in primary tumors and metastases, leading to high proteolytic activity in primary tumors and low activity in liver metastases. By virtue of its pro-migratory and pro-angiogenic activity, meprin-α may promote tumor progression in colorectal cancer.

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By analogy to gliosarcoma, the neologism "oligosarcoma" is to describe an uncommon form of biphasic central nervous system tumor composed of contiguous neuroepithelial and mesenchymal elements, each of which individually meet the criteria of oligodendroglioma and sarcoma, respectively. By virtue of its distinctive genotype (codeletion 1p/19q), oligodendroglioma is a particularly inviting paradigm to test the assumption that such mixed tumors are clonally derived from a glial primary. We observed this constellation in a 41-year-old male who underwent two resection procedures for a recurring right frontal tumor at five years' interval. On imaging, both lesions were contrast-enhancing, and measured 7 cm × 7 cm × 6.8 cm and 7 cm × 6.5 cm × 4cm, respectively. Following the first operation, temozolomide monotherapy was administered. Whereas initial histology showed conventional anaplastic oligodendroglioma, the recurrence consisted mostly of a fibrosarcoma-like, fascicular neoplasm that was immunoreactive for vimentin, smooth muscle actin, S100 protein, and focally epithelial membrane antigen. In between, a subset of otherwise indistinguishable spindle cells expressed GFAP, and focally merged with residues of oligodendroglioma. Molecular testing for loss of heterozygosity confirmed codeletion of 1p/19q in both the primary tumor and the sarcomatous recurrence. Similarly, generalized immunoreactivity for the mutant R132H form of isocitrate dehydrogenase in both lesions indicated an identical mutation of the IDH1 gene. By the above standards, biologically consistent "oligosarcomas" are felt to be exceedingly rare, and possibly participate of a nosologically heterogeneous group of combined glial/mesenchymal lesions that may also include iatrogenically induced second malignancies as well as true collision tumors.

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Modification of the ribose unit in DNA and RNA profoundly influences the self-rcognition and the biological properties of the nucleic acids. Conformational restriction of the ribose units, as in LNA and tricyclo-DNA, has been identified as a powerful tool to increase DNA and RNA affinity as well as biological stability and antisense properties. Apart from that sugar modified DNA analogues, as homo-DNA, have shown to be orthogonal base-pairing systems which by virtue of non-crosscommunicating with the natural nucleic acids open novel applications in biotechnology.

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The gene for agouti signaling protein (ASIP) is centrally involved in the expression of coat color traits in animals. The Mangalitza pig breed is characterized by a black-and-tan phenotype with black dorsal pigmentation and yellow or white ventral pigmentation. We investigated a Mangalitza x Piétrain cross and observed a coat color segregation pattern in the F2 generation that can be explained by virtue of two alleles at the MC1R locus and two alleles at the ASIP locus. Complete linkage of the black-and-tan phenotype to microsatellite alleles at the ASIP locus on SSC 17q21 was observed. Corroborated by the knowledge of similar mouse coat color mutants, it seems therefore conceivable that the black-and-tan pigmentation of Mangalitza pigs is caused by an ASIP allele a(t), which is recessive to the wild-type allele A. Toward positional cloning of the a(t) mutation, a 200-kb genomic BAC/PAC contig of this chromosomal region has been constructed and subsequently sequenced. Full-length ASIP cDNAs obtained by RACE differed in their 5' untranslated regions, whereas they shared a common open reading frame. Comparative sequencing of all ASIP exons and ASIP cDNAs between Mangalitza and Piétrain pigs did not reveal any differences associated with the coat color phenotype. Relative qRT-PCR analyses showed different dorsoventral skin expression intensities of the five ASIP transcripts in black-and-tan Mangalitza. The a(t) mutation is therefore probably a regulatory ASIP mutation that alters its dorsoventral expression pattern.

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A critical role for Tie1, an orphan endothelial receptor, in blood vessel morphogenesis has emerged from mutant mouse studies. Moreover, it was recently demonstrated that certain angiopoietin (Ang) family members can activate Tie1. We report here that Ang1 induces Tie1 phosphorylation in endothelial cells. Tie1 phosphorylation was, however, Tie2 dependent because 1) Ang1 failed to induce Tie1 phosphorylation when Tie2 was down-regulated in endothelial cells; 2) Tie1 phosphorylation was induced in the absence of Ang1 by either a constitutively active form of Tie2 or a Tie2 agonistic antibody; 3) in HEK 293 cells Ang1 phosphorylated a form of Tie1 without kinase activity when coexpressed with Tie2, and Ang1 failed to phosphorylate Tie1 when coexpressed with kinase-defective Tie2. Ang1-mediated AKT and 42/44MAPK phosphorylation is predominantly Tie2 mediated, and Tie1 down-regulates this pathway. Finally, based on a battery of in vitro and in vivo data, we show that a main role for Tie1 is to modulate blood vessel morphogenesis by virtue of its ability to down-regulate Tie2-driven signaling and endothelial survival. Our new observations help to explain why Tie1 null embryos have increased capillary densities in several organ systems. The experiments also constitute a paradigm for how endothelial integrity is fine-tuned by the interplay between closely related receptors by a single growth factor.

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The astacins are a subfamily of the metzincin superfamily of metalloproteinases. The first to be characterized was the crayfish enzyme astacin. To date more than 200 members of this family have been identified in species ranging from bacteria to humans. Astacins are involved in developmental morphogenesis, matrix assembly, tissue differentiation and digestion. Family members include the procollagen C-proteinase (BMP1, bone morphogenetic protein 1), tolloid and mammalian tolloid-like, HMP (Hydra vulgaris metalloproteinase), sea urchin BP10 (blastula protein) and SPAN (Strongylocentrotus purpuratus astacin), the 'hatching' subfamily comprising alveolin, ovastacin, LCE, HCE ('low' and 'high' choriolytic enzymes), nephrosin (from carp head kidney), UVS.2 from frog, and the meprins. In the human and mouse genomes, there are six astacin family genes (two meprins, three BMP1/tolloid-like, one ovastacin), but in Caenorhabditis elegans there are 40. Meprins are the only astacin proteinases that function on the membrane and extracellularly by virtue of the fact that they can be membrane-bound or secreted. They are unique in their domain structure and covalent subunit dimerization, oligomerization propensities, and expression patterns. They are normally highly regulated at the transcriptional and post-translational levels, localize to specific membranes or extracellular spaces, and can hydrolyse biologically active peptides, cytokines, extracellular matrix (ECM) proteins and cell-surface proteins. The in vivo substrates of meprins are unknown, but the abundant expression of these proteinases in the epithelial cells of the intestine, kidney and skin provide clues to their functions.

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Fatal falls from great height are a frequently encountered setting in forensic pathology. They present--by virtue of a calculable energy transmission to the body--an ideal model for the assessment of the effects of blunt trauma to a human body. As multislice computed tomography (MSCT) has proven not only to be invaluable in clinical examinations, but also to be a viable tool in post-mortem imaging, especially in the field of osseous injuries, we performed a MSCT scan on 20 victims of falls from great height. We hereby detected fractures and their distributions were compared with the impact energy. Our study suggests a marked increase of extensive damage to different body regions at about 20 kJ and more. The thorax was most often affected, regardless of the amount of impacting energy and the primary impact site. Cranial fracture frequency displayed a biphasic distribution with regard to the impacting energy; they were more frequent in energies of less than 10, and more than 20 kJ, but rarer in the intermediate energy group, namely that of 10-20 kJ.

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The radiological determination of foreign objects in corpses can be difficult if they are fragmented or deformed. With multislice computed tomography, radiodensities--referred to as Hounsfield units (HU)--can be measured. We examined the possibility of differentiating 21 frequently occurring foreign bodies, such as metals, rocks, and different manmade materials by virtue of their HU values. Gold, steel, and brass showed mean HU values of 30671-30710 (upper measurable limit), mean HU values for steel, silver, copper, and limestone were 20346, 16949, 14033, and 2765, respectively. The group consisting of objects, such as aluminum, tarmac, car front-window glass, and other rocks, displayed mean HU values of 2329-2131 HU. The mean HU value of bottle glass and car side-window glass was 2088, whereas windowpane glass was 493. HU value determination may therefore help in preautopsy differentiation between case-relevant and irrelevant foreign bodies and thus be useful for autopsy planning and extraction of the objects in question.

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A fundamental assumption in invasion biology is that most invasive species exhibit enhanced performance in their introduced range relative to their home ranges. This idea has given rise to numerous hypotheses explaining “invasion success” by virtue of altered ecological and evolutionary pressures. There are surprisingly few data, however, testing the underlying assumption that the performance of introduced populations, including organism size, reproductive output, and abundance, is enhanced in their introduced compared to their native range. Here, we combined data from published studies to test this hypothesis for 26 plant and 27 animal species that are considered to be invasive. On average, individuals of these 53 species were indeed larger, more fecund, and more abundant in their introduced ranges. The overall mean, however, belied significant variability among species, as roughly half of the investigated species (N = 27) performed similarly when compared to conspecific populations in their native range. Thus, although some invasive species are performing better in their new ranges, the pattern is not universal, and just as many are performing largely the same across ranges.

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PURPOSE In leukemic cutaneous T-cell lymphoma (L-CTCL), malignant T cells accumulate in the blood and give rise to widespread skin inflammation. Patients have intense pruritus, increased immunoglobulin E (IgE), and decreased T-helper (TH)-1 responses, and most die from infection. Depleting malignant T cells while preserving normal immunity is a clinical challenge. L-CTCL has been variably described as a malignancy of regulatory, TH2 and TH17 cells. EXPERIMENTAL DESIGN We analyzed phenotype and cytokine production in malignant and benign L-CTCL T cells, characterized the effects of malignant T cells on healthy T cells, and studied the immunomodulatory effects of treatment modalities in patients with L-CTCL. RESULTS Twelve out of 12 patients with L-CTCL overproduced TH2 cytokines. Remaining benign T cells were also strongly TH2 biased, suggesting a global TH2 skewing of the T-cell repertoire. Culture of benign T cells away from the malignant clone reduced TH2 and enhanced TH1 responses, but separate culture had no effect on malignant T cells. Coculture of healthy T cells with L-CTCL T cells reduced IFNγ production and neutralizing antibodies to interleukin (IL)-4 and IL-13 restored TH1 responses. In patients, enhanced TH1 responses were observed following a variety of treatment modalities that reduced malignant T-cell burden. CONCLUSIONS A global TH2 bias exists in both benign and malignant T cells in L-CTCL and may underlie the infectious susceptibility of patients. TH2 cytokines from malignant cells strongly inhibited TH1 responses. Our results suggest that therapies that inhibit TH2 cytokine activity, by virtue of their ability to improve TH1 responses, may have the potential to enhance both anticancer and antipathogen responses.