912 research outputs found

    MicroRNA expression differs in cutaneous squamous cell carcinomas and healthy skin of immunocompetent individuals

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    Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers, but the influence of microRNA (miRNA) expression has only been sporadically analysed. We hypothesized that miRNAs are differentially expressed in cSCC and hence influence its development. We therefore isolated total miRNA from well-differentiated cSCCs and from controls without SCC. Expression analyses of 12 miRNAs showed three significantly differentially expressed miRNAs. We identified a significant upregulation of the miR-21 and the miR-31, a proto-oncogene like miR-21. While the upregulated expression of miR-21 has been known for some time, the increased expression of miR-31 was never shown so clearly. Furthermore, we showed the upregulation of miRNA-205, which has never been described before. The miR-205 induces specific keratinocyte migration and could be a characteristic marker for cSCC. It has to be determined in following studies whether these upregulated expressions are specific for cSCC and if so, for which cSCC stages

    Enforced Bcl-2 Expression Inhibits Antigen-mediated Clonal Elimination of Peripheral B Cells in an Antigen Dose–dependent Manner and Promotes Receptor Editing in Autoreactive, Immature B Cells

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    The mechanisms that establish immune tolerance in immature and mature B cells appear to be distinct. Membrane-bound autoantigen is thought to induce developmental arrest and receptor editing in immature B cells, whereas mature B cells have shortened lifespans when exposed to the same stimulus. In this study, we used Eμ–bcl-2-22 transgenic (Tg) mice to test the prediction that enforced expression of the Bcl-2 apoptotic inhibitor in B cells would rescue mature, but not immature, B cells from tolerance induction. To monitor tolerance to the natural membrane autoantigen H-2Kb, we bred 3–83μδ (anti-Kk,b) Ig Tg mice to H-2b mice or to mice expressing transgene-driven Kb in the periphery. In 3–83μδ/bcl-2 Tg mice, deletion of autoreactive B cells induced by peripheral Kb antigen expression in the liver (MT-Kb Tg) or epithelia (KerIV-Kb Tg), was partly or completely inhibited, respectively. Furthermore, Bcl-2 protected peritoneal B-2 B cells from deletion mediated by acute antigen exposure, but this protection could be overcome by higher antigen dose. In contrast to its ability to block peripheral self-tolerance, Bcl-2 overexpression failed to inhibit central tolerance induced by bone marrow antigen expression, but instead, enhanced the receptor editing process. These studies indicate that apoptosis plays distinct roles in central and peripheral B cell tolerance

    The Non-Trapping Degree of Scattering

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    We consider classical potential scattering. If no orbit is trapped at energy E, the Hamiltonian dynamics defines an integer-valued topological degree. This can be calculated explicitly and be used for symbolic dynamics of multi-obstacle scattering. If the potential is bounded, then in the non-trapping case the boundary of Hill's Region is empty or homeomorphic to a sphere. We consider classical potential scattering. If at energy E no orbit is trapped, the Hamiltonian dynamics defines an integer-valued topological degree deg(E) < 2. This is calculated explicitly for all potentials, and exactly the integers < 2 are shown to occur for suitable potentials. The non-trapping condition is restrictive in the sense that for a bounded potential it is shown to imply that the boundary of Hill's Region in configuration space is either empty or homeomorphic to a sphere. However, in many situations one can decompose a potential into a sum of non-trapping potentials with non-trivial degree and embed symbolic dynamics of multi-obstacle scattering. This comprises a large number of earlier results, obtained by different authors on multi-obstacle scattering.Comment: 25 pages, 1 figure Revised and enlarged version, containing more detailed proofs and remark

    Risk of Cutaneous Squamous Cell Carcinoma Development in Renal Transplant Recipients Is Independent of TMC/EVER Alterations

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    Renal transplant recipients (RTRs) have an increased risk of developing nonmelanoma skin cancer, mainly cutaneous squamous cell carcinoma (cSCC). Two genes (TMC6/EVER1 and TMC8/EVER2), mutated in epidermodysplasia verruciformis (EV) patients with an increased risk of cSCC development, contain numerous single-nucleotide polymorphisms (SNPs).; To evaluate the effect of SNPs in both TMC/EVER genes on the different susceptibilities of RTRs to cSCC.; We determined the occurrence of cSCC in 105 RTRs who were transplanted at least 7 years previously and investigated the frequency of 26 SNPs within both TMC/EVER genes in severely affected (n = 16) as well as in nonaffected RTRs (n = 25).; Our data did not indicate a significant association between any SNP genotype and risk of cSCC development in RTRs.; To clarify the correlation between SNPs in both TMC genes and cSCC development in RTRs, integrated investigations of large cohorts including both RTRs and immunocompetent individuals with consideration of cSCC status, SNP genotype and human papillomavirus status might be necessary

    Risk of Cutaneous Squamous Cell Carcinoma Development in Renal Transplant Recipients Is Independent of TMC/EVER Alterations

    Get PDF
    Renal transplant recipients (RTRs) have an increased risk of developing nonmelanoma skin cancer, mainly cutaneous squamous cell carcinoma (cSCC). Two genes (TMC6/EVER1 and TMC8/EVER2), mutated in epidermodysplasia verruciformis (EV) patients with an increased risk of cSCC development, contain numerous single-nucleotide polymorphisms (SNPs).; To evaluate the effect of SNPs in both TMC/EVER genes on the different susceptibilities of RTRs to cSCC.; We determined the occurrence of cSCC in 105 RTRs who were transplanted at least 7 years previously and investigated the frequency of 26 SNPs within both TMC/EVER genes in severely affected (n = 16) as well as in nonaffected RTRs (n = 25).; Our data did not indicate a significant association between any SNP genotype and risk of cSCC development in RTRs.; To clarify the correlation between SNPs in both TMC genes and cSCC development in RTRs, integrated investigations of large cohorts including both RTRs and immunocompetent individuals with consideration of cSCC status, SNP genotype and human papillomavirus status might be necessary

    Equilibrium shapes of flat knots

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    We study the equilibrium shapes of prime and composite knots confined to two dimensions. Using rigorous scaling arguments we show that, due to self-avoiding effects, the topological details of prime knots are localised on a small portion of the larger ring polymer. Within this region, the original knot configuration can assume a hierarchy of contracted shapes, the dominating one given by just one small loop. This hierarchy is investigated in detail for the flat trefoil knot, and corroborated by Monte Carlo simulations.Comment: 4 pages, 3 figure

    Low fertility and population replacement in Scotland

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    It has been argued that Scotland faces population ageing and decline that will have potentially serious economic and social consequences, and that the origin of these processes lie in its low and declining fertility rates. After considering alternatives to the total period rate measure of fertility, empirical evidence and theoretical argument about low fertility and its consequences is briefly reviewed. The paper argues that low fertility in general may not be the problem it is often purported to be, that Scotland has relatively high fertility, and that pro-natalist policies are neither desirable nor necessary. It suggests that low fertility and population ageing may be viewed as positive developments, and that within Europe, Scotland is distinguished more by its excess of early deaths than by any shortage of births.Peer reviewe

    Neurologic complications in adult living donor liver transplant patients: an underestimated factor?

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    Liver transplantation is the only curative treatment in patients with end-stage liver disease. Neurological complications (NC) are increasingly reported to occur in patients after cadaveric liver transplantation. This retrospective cohort study aims to evaluate the incidence and causes of NC in living donor liver transplant (LDLT) patients in our transplant center. Between August 1998 and December 2005, 121 adult LDLT patients were recruited into our study. 17% of patients experienced NC, and it occurred significantly more frequently in patients with alcoholic cirrhosis (42%) and autoimmune hepatitis (43%) as compared with patients with hepatitis B or C (9/10%, P = 0.013). The most common NC was encephalopathy (47.6%) followed by seizures (9.5%). The choice of immunosuppression by calcineurin inhibitor (Tacrolimus or Cyclosporin A) showed no significant difference in the incidence of NC (19 vs. 17%). The occurrence of NC did not influence the clinical outcome, since mortality rate, median ICU stay and length of hospital stay were similar between the two groups. Most patients who survived showed a nearly complete recovery of their NC. NCs occur in approximately 1 in 6 patients after LDLT and seem to be predominantly transient in nature, without major impact on clinical outcome

    Imaging Shock Waves in Diamond with Both High Temporal and Spatial Resolution at an XFEL

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    The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnified x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions

    A New Human Somatic Stem Cell from Placental Cord Blood with Intrinsic Pluripotent Differentiation Potential

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    Here a new, intrinsically pluripotent, CD45-negative population from human cord blood, termed unrestricted somatic stem cells (USSCs) is described. This rare population grows adherently and can be expanded to 1015 cells without losing pluripotency. In vitro USSCs showed homogeneous differentiation into osteoblasts, chondroblasts, adipocytes, and hematopoietic and neural cells including astrocytes and neurons that express neurofilament, sodium channel protein, and various neurotransmitter phenotypes. Stereotactic implantation of USSCs into intact adult rat brain revealed that human Tau-positive cells persisted for up to 3 mo and showed migratory activity and a typical neuron-like morphology. In vivo differentiation of USSCs along mesodermal and endodermal pathways was demonstrated in animal models. Bony reconstitution was observed after transplantation of USSC-loaded calcium phosphate cylinders in nude rat femurs. Chondrogenesis occurred after transplanting cell-loaded gelfoam sponges into nude mice. Transplantation of USSCs in a noninjury model, the preimmune fetal sheep, resulted in up to 5% human hematopoietic engraftment. More than 20% albumin-producing human parenchymal hepatic cells with absence of cell fusion and substantial numbers of human cardiomyocytes in both atria and ventricles of the sheep heart were detected many months after USSC transplantation. No tumor formation was observed in any of these animals
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