997 resultados para Peripheral Regions


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Peripheral nerve injury is a serious problem affecting significantly patients' life. Autografts are the "gold standard" used to repair the injury gap, however, only 50% of patients fully recover from the trauma. Artificial conduits are a valid alternative to repairing peripheral nerve. They aim at confining the nerve environment throughout the regeneration process, and providing guidance to axon outgrowth. Biocompatible materials have been carefully designed to reduce inflammation and scar tissue formation, but modifications of the inner lumen are still required in order to optimise the scaffolds. Biomicking the native neural tissue with extracellular matrix fillers or coatings showed great promises in repairing longer gaps and extending cell survival. In addition, extracellular matrix molecules provide a platform to further bind growth factors that can be released in the system over time. Alternatively, conduit fillers can be used for cell transplantation at the injury site, reducing the lag time required for endogenous Schwann cells to proliferate and take part in the regeneration process. This review provides an overview on the importance of extracellular matrix molecules in peripheral nerve repair.

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Soft tissue sarcomas (STS) with complex genomic profiles (50% of all STS) are predominantly composed of spindle cell/pleomorphic sarcomas, including leiomyosarcoma, myxofibrosarcoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma, malignant peripheral nerve sheath tumor, angiosarcoma, extraskeletal osteosarcoma, and spindle cell/pleomorphic unclassified sarcoma (previously called spindle cell/pleomorphic malignant fibrous histiocytoma). These neoplasms show, characteristically, gains and losses of numerous chromosomes or chromosome regions, as well as amplifications. Many of them share recurrent aberrations (e.g., gain of 5p13-p15) that seem to play a significant role in tumor progression and/or metastatic dissemination. In this paper, we review the cytogenetic, molecular genetic, and clinicopathologic characteristics of the most common STS displaying complex genomic profiles. Features of diagnostic or prognostic relevance will be discussed when needed.

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PURPOSE: Statins have beneficial effects in patients after myocardial infarction and at least part of the benefit results from mobilization of marrow endothelial progenitors to repopulate damaged myocardial tissues. This study examines if statins may have the same effect in mobilizing marrow progenitors to be harvested and subsequently used in high-dose chemotherapy with progenitor cell rescue in multiple myeloma. METHODS: From 2006 to 2012, 86 patients with multiple myeloma were mobilized with the use of G-CSF and were retrospectively analyzed. Patients with other malignancies or mobilized with the use of chemotherapy or with plerixafor were excluded. RESULTS: The median age of the patients was 60 years. 72 patients had received one line of chemotherapy and 14 patients two or more lines of chemotherapy. Twenty patients were taking statins at the time of the harvest while 66 patients were not. In the group of patients taking statins the success rate of first leukapheresis (obtaining the target number of 4 × 10(6) CD34+ cells/kg) was 85 % while in the group not taking statins this rate was 63.6 %. Despite the comparatively small number of patients this difference approached statistical significance (χ (2) = 0.07). CONCLUSION: This retrospective analysis of 86 patients shows for the first time a possible benefit of statins for peripheral blood progenitor cells mobilization in patients with multiple myeloma. Larger studies would be required to clarify the issue. If their effectiveness is confirmed, statins could be a safe and cheaper addition to chemotherapy and plerixafor for peripheral hematopoietic stem cell mobilization.

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The liver secretes triglyceride-rich VLDLs, and the triglycerides in these particles are taken up by peripheral tissues, mainly heart, skeletal muscle, and adipose tissue. Blocking hepatic VLDL secretion interferes with the delivery of liver-derived triglycerides to peripheral tissues and results in an accumulation of triglycerides in the liver. However, it is unclear how interfering with hepatic triglyceride secretion affects adiposity, muscle triglyceride stores, and insulin sensitivity. To explore these issues, we examined mice that cannot secrete VLDL [due to the absence of microsomal triglyceride transfer protein (Mttp) in the liver]. These mice exhibit markedly reduced levels of apolipoprotein B-100 in the plasma, along with reduced levels of triglycerides in the plasma. Despite the low plasma triglyceride levels, triglyceride levels in skeletal muscle were unaffected. Adiposity and adipose tissue triglyceride synthesis rates were also normal, and body weight curves were unaffected. Even though the blockade of VLDL secretion caused hepatic steatosis accompanied by increased ceramides and diacylglycerols in the liver, the mice exhibited normal glucose tolerance and were sensitive to insulin at the whole-body level, as judged by hyperinsulinemic euglycemic clamp studies. Normal hepatic glucose production and insulin signaling were also maintained in the fatty liver induced by Mttp deletion. Thus, blocking VLDL secretion causes hepatic steatosis without insulin resistance, and there is little effect on muscle triglyceride stores or adiposity

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Although not specific, an increased in peripheral blood eosinophils may contribute substantially to the diagnosis of numerous infectious, allergic and inflammatory diseases. The scope of this article is to detail pathologies associated with peripheral eosinophilia by order of frequency and to guide further investigations.

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Traumatic injuries resulting in peripheral nerve lesions often require a graft to bridge the gap. Although autologous nerve auto-graft is still the first-choice strategy in reconstructions, it has the severe disadvantage of the sacrifice of a functional nerve. Cell transplantation in a bioartificial conduit is an alternative strategy to create a favourable environment for nerve regeneration. We decided to test new fibrin nerve conduits seeded with various cell types (primary Schwann cells and adult stem cells differentiated to a Schwann cell-like phenotype) for repair of sciatic nerve injury. Two weeks after implantation, the conduits were removed and examined by immunohistochemistry for axonal regeneration (evaluated by PGP 9.5 expression) and Schwann cell presence (detected by S100 expression). The results show a significant increase in axonal regeneration in the group of fibrin seeded with Schwann cells compared with the empty fibrin conduit. Differentiated adipose-derived stem cells also enhanced regeneration distance in a similar manner to differentiated bone marrow mesenchymal stem cells. These observations suggest that adipose-derived stem cells may provide an effective cell population, without the limitations of the donor-site morbidity associated with isolation of Schwann cells, and could be a clinically translatable route towards new methods to enhance peripheral nerve repair.

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After peripheral nerve injury in adult mammals, reestablishment of functional connections depends on several parameters including neurotrophic factors, the extracellular matrix, and hormones. However, little is known about the contribution of hormones to peripheral nerve regeneration. Thyroid hormones, which are required for the development and maturation of the central nervous system, are also important for the development of peripheral nerves. The action of triiodothyronine (T3) on responsive cells is mediated through nuclear thyroid hormone receptors (TRs) which modulate the expression of specific genes in target cells. Thus, to study the effect of T3, it is first necessary to know whether the target tissues possess TRs. The fact that sciatic nerve cells possess functional TRs suggests that these cells can respond to T3 and, as a consequence, that thyroid hormone may be involved in peripheral nerve regeneration. The silicone nerve guide model provides an excellent system to study the action of local administration of T3. Evidence from such studies demonstrate that animals treated locally with T3 at the level of transection have more complete regeneration of sciatic nerve and better functional recovery. Among the possible regulatory mechanisms by which T3 enhances peripheral nerve regeneration is rapid action on both axotomized neurons and Schwann cells which, in turn, produce a lasting and stimulatory effect on peripheral nerve regeneration. It is probable that T3 up- or down-regulates gene expression of one or more growth factors, extracellular matrix, or cell adhesion molecules, all of which stimulate peripheral nerve regeneration. This could explain the greater effect of T3 on nerve regeneration compared with the effect of any one growth factor or adhesion molecule.

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The importance of financial market reforms in combating corruption has been highlighted in the theoretical literature but has not been systemically tested empirically. In this study we provide a first pass at testing this relationship using both linear and nonmonotonic forms of the relationship between corruption and financial intermediation. Our study finds a negative and statistically significant impact of financial intermediation on corruption. Specifically, the results imply that a one standard deviation increase in financial intermediation is associated with a decrease in corruption of 0.20 points, or 16 percent of the standard deviation in the corruption index and this relationship is shown to be robust to a variety of specification changes, including: (i) different sets of control variables; (ii) different econometrics techniques; (iii) different sample sizes; (iv) alternative corruption indices; (v) removal of outliers; (vi) different sets of panels; and (vii) allowing for cross country interdependence, contagion effects, of corruption.

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An extensive economics and regional science literature has discussed the importance of social capital for economic growth and development. Yet, what social capital is and how it is formed are elusive issues, which require further investigation. Here, we refer to social capital in terms of civic capital and good culture , as rephrased by Guiso, Sapienza and Zingales (2010) and Tabellini (2010). The accumulation of this kind of capital allows the emerging of regional informal institutions, which may help explaining diff erences in regional development. In this paper, we take a regional perspective and use exploratory space and space-time methods to assess whether geography, via proximity, contributes to the formation of social capital across European regions. In particular, we ask whether generalized trust, a fundamental constituent of social capital and an ingredient of economic development, tends to be clustered across space and over time. From the policy standpoint, the spatial hysteresis of regional trust may contribute to the formation of spatial traps of social capital and act as a further barrier to regional economic development and convergence.

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Functional RNA structures play an important role both in the context of noncoding RNA transcripts as well as regulatory elements in mRNAs. Here we present a computational study to detect functional RNA structures within the ENCODE regions of the human genome. Since structural RNAs in general lack characteristic signals in primary sequence, comparative approaches evaluating evolutionary conservation of structures are most promising. We have used three recently introduced programs based on either phylogenetic-stochastic context-free grammar (EvoFold) or energy directed folding (RNAz and AlifoldZ), yielding several thousand candidate structures (corresponding to approximately 2.7% of the ENCODE regions). EvoFold has its highest sensitivity in highly conserved and relatively AU-rich regions, while RNAz favors slightly GC-rich regions, resulting in a relatively small overlap between methods. Comparison with the GENCODE annotation points to functional RNAs in all genomic contexts, with a slightly increased density in 3'-UTRs. While we estimate a significant false discovery rate of approximately 50%-70% many of the predictions can be further substantiated by additional criteria: 248 loci are predicted by both RNAz and EvoFold, and an additional 239 RNAz or EvoFold predictions are supported by the (more stringent) AlifoldZ algorithm. Five hundred seventy RNAz structure predictions fall into regions that show signs of selection pressure also on the sequence level (i.e., conserved elements). More than 700 predictions overlap with noncoding transcripts detected by oligonucleotide tiling arrays. One hundred seventy-five selected candidates were tested by RT-PCR in six tissues, and expression could be verified in 43 cases (24.6%).

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The housing market has been extensively investigated in the literature; however there is a lack of understanding of the fundamentals a ffecting housing affordability across UK regions as measured by the price to income ratio. The aim of this paper is twofold; fi rstly we calculate the a ffordability ratio based on individuals' incomes. Second we set o f to ask which socio-economic factors could a affect this ratio. The analysis finds a strong influence coming from the mortgage rate, the residents' age and academic quali fications. We also report a positive and signifi cant e ffect from foreign capital coming to the UK. Finally, we record a non-negligible degree of heterogeneity across the twelve regions.