61 research outputs found

    7 Tesla MRI of Balo's concentric sclerosis versus multiple sclerosis lesions

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    Background: Baló’s concentric sclerosis (BCS) is a rare condition characterized by concentrically layered white matter lesions. While its pathogenesis is unknown, hypoxia-induced tissue injury and chemotactic stimuli have been proposed as potential causes of BCS lesion formation. BCS has been suggested to be a variant of multiple sclerosis (MS). Here, we aimed to elucidate similarities and differences between BCS and MS by describing lesion morphology and localization in high-resolution 7 Tesla (7 T) magnetic resonance imaging (MRI) scans. Methods: Ten patients with Baló-type lesions underwent 7 T MRI, and 10 relapsing remitting MS patients served as controls. The 7 T MR imaging protocol included 3D T1-weighted (T1w) magnetization-prepared rapid gradient echo, 2D high spatial resolution T2*-weighted (T2*w) fast low-angle shot and susceptibility-weighted imaging. Results: Intralesional veins were visible in the center of all but one Baló-type lesion. Four Baló-type lesions displayed inhomogeneous intralesional T2*w signal intensities, which are suggestive of microhemorrhages or small ectatic venules. Eight of 10 BCS patients presented with 97 additional lesions, 36 of which (37%) had a central vein. Lesions involving the cortical gray matter and the U-fibers were not detected in BCS patients. Conclusion: Our findings support the hypothesis that BCS and MS share common pathogenetic mechanisms but patients present with different lesion phenotypes

    A tiered approach to the use of alternatives to animal testing for the safety assessment of cosmetics: Eye irritation

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    AbstractThe need for alternative approaches to replace the in vivo rabbit Draize eye test for evaluation of eye irritation of cosmetic ingredients has been recognised by the cosmetics industry for many years. Extensive research has lead to the development of several assays, some of which have undergone formal validation. Even though, to date, no single in vitro assay has been validated as a full replacement for the rabbit Draize eye test, organotypic assays are accepted for specific and limited regulatory purposes. Although not formally validated, several other in vitro models have been used for over a decade by the cosmetics industry as valuable tools in a weight of evidence approach for the safety assessment of ingredients and finished products. In light of the deadlines established in the EU Cosmetics Directive for cessation of animal testing for cosmetic ingredients, a COLIPA scientific meeting was held in Brussels on 30th January, 2008 to review the use of alternative approaches and to set up a decision-tree approach for their integration into tiered testing strategies for hazard and safety assessment of cosmetic ingredients and their use in products. Furthermore, recommendations are given on how remaining data gaps and research needs can be addressed

    Replicability, Robustness, and Reproducibility in Psychological Science

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    Replication—an important, uncommon, and misunderstood practice—is gaining appreciation in psychology. Achieving replicability is important for making research progress. If findings are not replicable, then prediction and theory development are stifled. If findings are replicable, then interrogation of their meaning and validity can advance knowledge. Assessing replicability can be productive for generating and testing hypotheses by actively confronting current understandings to identify weaknesses and spur innovation. For psychology, the 2010s might be characterized as a decade of active confrontation. Systematic and multi-site replication projects assessed current understandings and observed surprising failures to replicate many published findings. Replication efforts highlighted sociocultural challenges such as disincentives to conduct replications and a tendency to frame replication as a personal attack rather than a healthy scientific practice, and they raised awareness that replication contributes to self-correction. Nevertheless, innovation in doing and understanding replication and its cousins, reproducibility and robustness, has positioned psychology to improve research practices and accelerate progress

    DKK1 expression by synovial fibroblasts in very early rheumatoid arthritis associates with lymphocyte adhesion in an in vitro flow co-culture system

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    BACKGROUND: Synovial fibroblasts play a key role in joint destruction and regulation of the inflammatory infiltrate in established rheumatoid arthritis (RA). The mechanisms by which this occurs in the earliest stages of RA are largely unknown. We investigated the role of Dickkopf-related protein 1 (DKK1) produced by synovial fibroblasts of patients with very early rheumatoid arthritis (VeRA). METHODS: Fibroblasts were isolated from the disease-modifying anti-rheumatic drug–naive Birmingham early arthritis cohort of patients with new onset of clinically apparent arthritis and inflammatory symptoms of ≤12 weeks’ duration, who at follow-up had either resolving arthritis or RA. Endothelial fibroblast co-cultures were formed using porous filters, and lymphocyte adhesion to co-cultures was assessed using phase-contrast microscopy. DKK1 gene expression and secretion were quantified by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. RESULTS: Synovial fibroblasts from patients with VeRA expressed significantly higher levels of DKK1 messenger RNA than those from patients with resolving arthritis. A similar trend was observed for DKK1 protein secretion. In co-culture constructs, more DKK1 tended to be secreted in co-cultures incorporating fibroblasts from VeRA than in co-cultures from non-inflamed joints and resolving arthritis. DKK1 secretion during co-culture positively correlated with lymphocyte adhesion. CONCLUSIONS: Alterations in DKK1 could be involved in the pathogenesis and perpetuation of the inflammatory response in the earliest clinically apparent stages of RA

    Integration und Desintegration der Kulturen im europäischen Mittelalter

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    Das mittelalterliche Europa war keine christliche Einheitskultur, sondern geprägt von vielfältigen Prozessen des Kontakts und der Abgrenzung zwischen Kulturen, bei denen die drei monotheistischen Religionen Christentum, Judentum und Islam eine herausragende Rolle spielten. Seit 2005 erforscht das DFG-Schwerpunktprogramm "Integration und Desintegration der Kulturen im europäischen Mittelalter" die Geschichte Europas als Geschichte kultureller Differenzen. Der Band dokumentiert die Dynamiken und Erträge eines wissenschaftsorganisatorischen Experiments: Gegliedert in fächerübergreifende Arbeitsgruppen, erforschten 24 Einzelprojekte aus 14 Disziplinen Integrations- und Desintegrationsprozesse von Skandinavien bis Ägypten, von der Iberischen Halbinsel bis zu den Steppen Zentralasiens in komparativem Zugriff; sie präsentieren ihre Ergebnisse nun in Beiträgen, die von mehreren Autorinnen und Autoren gemeinsam verfasst worden sind. Dabei werden Begriffe wie "Kultur" problematisiert und schon eingeführte Konzepte wie "Integration/Desintegration", "Inklusion/Exklusion", "Hybridisierung" und "Transfer" als Instrumente transkultureller Mediävistik auf den Prüfstand gestellt. Das Ende der Laufzeit des Schwerpunktprogramms gibt zugleich Anlass, methodisch-theoretische Einsichten der gemeinsamen Forschung wie auch praktische Erfahrungen bei der transdisziplinären Zusammenarbeit zu bilanzieren

    TGFβ pathway limits dedifferentiation following WNT and MAPK pathway activation to suppress intestinal tumourigenesis

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    Recent studies have suggested increased plasticity of differentiated cells within the intestine to act both as intestinal stem cells (ISCs) and tumour-initiating cells. However, little is known of the processes that regulate this plasticity. Our previous work has shown that activating mutations of Kras or the NF-κB pathway can drive dedifferentiation of intestinal cells lacking Apc. To investigate this process further, we profiled both cells undergoing dedifferentiation in vitro and tumours generated from these cells in vivo by gene expression analysis. Remarkably, no clear differences were observed in the tumours; however, during dedifferentiation in vitro we found a marked upregulation of TGFβ signalling, a pathway commonly mutated in colorectal cancer (CRC). Genetic inactivation of TGFβ type 1 receptor (Tgfbr1/Alk5) enhanced the ability of KrasG12D/+ mutation to drive dedifferentiation and markedly accelerated tumourigenesis. Mechanistically this is associated with a marked activation of MAPK signalling. Tumourigenesis from differentiated compartments is potently inhibited by MEK inhibition. Taken together, we show that tumours arising in differentiated compartments will be exposed to different suppressive signals, for example, TGFβ and blockade of these makes tumourigenesis more efficient from this compartment
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