107 research outputs found

    Brain antigens in functionally distinct antigen-presenting cell populations in cervical lymph nodes in MS and EAE

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    Drainage of central nervous system (CNS) antigens to the brain-draining cervical lymph nodes (CLN) is likely crucial in the initiation and control of autoimmune responses during multiple sclerosis (MS). We demonstrate neuronal antigens within CLN of MS patients. In monkeys and mice with experimental autoimmune encephalomyelitis (EAE) and in mouse models with non-inflammatory CNS damage, the type and extent of CNS damage was associated with the frequencies of CNS antigens within the cervical lymph nodes. In addition, CNS antigens drained to the spinal-cord-draining lumbar lymph nodes. In human MS CLN, neuronal antigens were present in pro-inflammatory antigen-presenting cells (APC), whereas the majority of myelin-containing cells were anti-inflammatory. This may reflect a different origin of the cells or different drainage mechanisms. Indeed, neuronal antigen-containing cells in human CLN did not express the lymph node homing receptor CCR7, whereas myelin antigen-containing cells in situ and in vitro did. Nevertheless, CLN from EAE-affected CCR7-deficient mice contained equal amounts of myelin and neuronal antigens as wild-type mice. We conclude that the type and frequencies of CNS antigens within the CLN are determined by the type and extent of CNS damage. Furthermore, the presence of myelin and neuronal antigens in functionally distinct APC populations within MS CLN suggests that differential immune responses can be evoked

    Life-History Evolution on Tropidurinae Lizards: Influence of Lineage, Body Size and Climate

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    The study of life history variation is central to the evolutionary theory. In many ectothermic lineages, including lizards, life history traits are plastic and relate to several sources of variation including body size, which is both a factor and a life history trait likely to modulate reproductive parameters. Larger species within a lineage, for example tend to be more fecund and have larger clutch size, but clutch size may also be influenced by climate, independently of body size. Thus, the study of climatic effects on lizard fecundity is mandatory on the current scenario of global climatic change. We asked how body and clutch size have responded to climate through time in a group of tropical lizards, the Tropidurinae, and how these two variables relate to each other. We used both traditional and phylogenetic comparative methods. Body and clutch size are variable within Tropidurinae, and both traits are influenced by phylogenetic position. Across the lineage, species which evolved larger size produce more eggs and neither trait is influenced by temperature components. A climatic component of precipitation, however, relates to larger female body size, and therefore seems to exert an indirect relationship on clutch size. This effect of precipitation on body size is likely a correlate of primary production. A decrease in fecundity is expected for Tropidurinae species on continental landmasses, which are predicted to undergo a decrease in summer rainfall

    New Approaches in the Differentiation of Human Embryonic Stem Cells and Induced Pluripotent Stem Cells toward Hepatocytes

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    Orthotropic liver transplantation is the only established treatment for end-stage liver diseases. Utilization of hepatocyte transplantation and bio-artificial liver devices as alternative therapeutic approaches requires an unlimited source of hepatocytes. Stem cells, especially embryonic stem cells, possessing the ability to produce functional hepatocytes for clinical applications and drug development, may provide the answer to this problem. New discoveries in the mechanisms of liver development and the emergence of induced pluripotent stem cells in 2006 have provided novel insights into hepatocyte differentiation and the use of stem cells for therapeutic applications. This review is aimed towards providing scientists and physicians with the latest advancements in this rapidly progressing field

    Identification of Pax6-Dependent Gene Regulatory Networks in the Mouse Lens

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    Lineage-specific DNA-binding transcription factors regulate development by activating and repressing particular set of genes required for the acquisition of a specific cell type. Pax6 is a paired domain and homeodomain-containing transcription factor essential for development of central nervous, olfactory and visual systems, as well as endocrine pancreas. Haploinsufficiency of Pax6 results in perturbed lens development and homeostasis. Loss-of-function of Pax6 is incompatible with lens lineage formation and results in abnormal telencephalic development. Using DNA microarrays, we have identified 559 genes expressed differentially between 1-day old mouse Pax6 heterozygous and wild type lenses. Of these, 178 (31.8%) were similarly increased and decreased in Pax6 homozygous embryonic telencephalon [Holm PC, Mader MT, Haubst N, Wizenmann A, Sigvardsson M, Götz M (2007) Loss- and gain-of-function analyses reveals targets of Pax6 in the developing mouse telencephalon. Mol Cell Neurosci 34: 99–119]. In contrast, 381 (68.2%) genes were differently regulated between the lens and embryonic telencephalon. Differential expression of nine genes implicated in lens development and homeostasis: Cspg2, Igfbp5, Mab21l2, Nrf2f, Olfm3, Spag5, Spock1, Spon1 and Tgfb2, was confirmed by quantitative RT-PCR, with five of these genes: Cspg2, Mab21l2, Olfm3, Spag5 and Tgfb2, identified as candidate direct Pax6 target genes by quantitative chromatin immunoprecipitation (qChIP). In Mab21l2 and Tgfb2 promoter regions, twelve putative individual Pax6-binding sites were tested by electrophoretic mobility shift assays (EMSAs) with recombinant Pax6 proteins. This led to the identification of two and three sites in the respective Mab21l2 and Tgfb2 promoter regions identified by qChIPs. Collectively, the present studies represent an integrative genome-wide approach to identify downstream networks controlled by Pax6 that control mouse lens and forebrain development

    Therapist Effects and the Impact of Early Therapeutic Alliance on Symptomatic Outcome in Chronic Fatigue Syndrome

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    Few studies have examined therapist effects and therapeutic alliance (TA) in treatments for chronic fatigue syndrome (CFS). Therapist effects are the differences in outcomes achieved by different therapists. TA is the quality of the bond and level of agreement regarding the goals and tasks of therapy. Prior research suffers the methodological problem that the allocation of therapist was not randomized, meaning therapist effects may be confounded with selection effects. We used data from a randomized controlled treatment trial of 296 people with CFS. The trial compared pragmatic rehabilitation (PR), a nurse led, home based self-help treatment, a counselling-based treatment called supportive listening (SL), with general practitioner treatment as usual. Therapist allocation was randomized. Primary outcome measures, fatigue and physical functioning were assessed blind to treatment allocation. TA was measured in the PR and SL arms. Regression models allowing for interactions were used to examine relationships between (i) therapist and therapeutic alliance, and (ii) therapist and average treatment effect (the difference in mean outcomes between different treatment conditions). We found no therapist effects. We found no relationship between TA and the average treatment effect of a therapist. One therapist formed stronger alliances when delivering PR compared to when delivering SL (effect size 0.76, SE 0.33, 95% CI 0.11 to 1.41). In these therapies for CFS, TA does not influence symptomatic outcome. The lack of significant therapist effects on outcome may result from the trial’s rigorous quality control, or random therapist allocation, eliminating selection effects. Further research is needed

    Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

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    Pan-cancer analysis of whole genomes

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    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
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