231 research outputs found
Enhancing Situation Awareness in Real Time Geospatial Visualization
Today’s hardware and software infrastructure enables large-scale visualization of (near) real-time data in a geospatial context, which is attractive in a variety of application areas ranging from military applications to disaster management and incident response. The drawback on the other hand is that combined visualizations might lead to an overload of human processing capacity, for instance if multiple dynamic aspects must be observed in parallel. The objective for our research is to develop a solution which enhances the situation awareness of the user by identifying the appropriate means of visualizing information based on the user’s task and a given situation. In this paper, we propose an approach and associated system architecture how this objective can be reached. The primary ingredient of our approach is the combination of a GIS system and logic-based ontology representation and reasoning system
Thymic Medullary Epithelial Cell Differentiation, Thymocyte Emigration, and the Control of Autoimmunity Require Lympho–Epithelial Cross Talk via LTβR
Thymocytes depend on the interaction with thymic epithelial cells for the generation of a diverse, nonautoreactive T cell repertoire. In turn, thymic epithelial cells acquire their three-dimensional cellular organization via instructive signals from developing thymocytes. The nature of these signals has been elusive so far. We show that thymocytes and medullary epithelial cells (MECs) communicate via the lymphotoxin β receptor (LTβR) signaling axis. Normal differentiation of thymic MECs requires LTβR ligand on thymocytes and LTβR together with nuclear factor–κB-inducing kinase (Nik) in thymic epithelial cells. Impaired lympho–epithelial cross talk in the absence of the LTβR causes aberrant differentiation and reduced numbers of thymic MECs, leads to the retention of mature T lymphocytes, and is associated with autoimmune phenomena, suggesting an unexpected role for LTβR signaling in central tolerance induction
The presence of phosphatidylinositol-4,5-bisphosphate directly impacts on amphetamine-induced serotonin transporter-mediated efflux
A membrane network of receptors and enzymes for adenine nucleotides and nucleosides
AbstractMost cells express more than one receptor plus degrading enzymes for adenine nucleotides or nucleosides, and cellular responses to purines are rarely compatible with the actions of single receptors. Therefore, these receptors are viewed as components of a combinatorial receptor web rather than self-dependent entities, but it remained unclear to what extent they can associate with each other to form signalling units. P2Y1, P2Y2, P2Y12, P2Y13, P2X2, A1, A2A receptors and NTPDase1 and -2 were expressed as fluorescent fusion proteins which were targeted to membranes and signalled like the unlabelled counterparts. When tested by FRET microscopy, all the G protein-coupled receptors proved able to form heterooligomers with each other, and P2Y1, P2Y12, P2Y13, A1, A2A, and P2X2 receptors also formed homooligomers. P2Y receptors did not associate with P2X, but G protein-coupled receptors formed heterooligomers with NTPDase1, but not NTPDase2. The specificity of prototypic interactions (P2Y1/P2Y1, A2A/P2Y1, A2A/P2Y12) was corroborated by FRET competition or co-immunoprecipitation. These results demonstrate that G protein-coupled purine receptors associate with each other and with NTPDase1 in a highly promiscuous manner. Thus, purinergic signalling is not only determined by the expression of receptors and enzymes but also by their direct interaction within a previously unrecognized multifarious membrane network
Die grundlegende Untersuchung uber die Theorien von Unternehmungsbewertung
Na+/H+ antiporters are integral membrane proteins that are present in almost every cell and in every kingdom of life. They are essential for the regulation of intracellular pH-value, Na+-concentration and cell volume. These secondary active transporters exchange sodium ions against protons via an alternating access mechanism, which is not understood in full detail. Na+/H+ antiporters show distinct species-specific transport characteristics and regulatory properties that correlate with respective physiological functions. Here we present the characterization of the Na+/H+ antiporter NhaA from Salmonella enterica serovar Thyphimurium LT2, the causing agent of food-born human gastroenteritis and typhoid like infections. The recombinant antiporter was functional in vivo and in vitro. Expression of its gene complemented the Na+-sensitive phenotype of an E. coli strain that lacks the main Na+/H+ antiporters. Purified to homogeneity, the antiporter was a dimer in solution as accurately determined by size-exclusion chromatography combined with multi-angle laser-light scattering and refractive index monitoring. The purified antiporter was fully capable of electrogenic Na+(Li+)/H+-antiport when reconstituted in proteoliposomes and assayed by solid-supported membrane-based electrophysiological measurements. Transport activity was inhibited by 2-aminoperimidine. The recorded negative currents were in agreement with a 1Na+(Li+)/2H+ stoichiometry. Transport activity was low at pH 7 and up-regulation above this pH value was accompanied by a nearly 10-fold decrease of KmNa (16 mM at pH 8.5) supporting a competitive substrate binding mechanism. K+ does not affect Na+ affinity or transport of substrate cations, indicating that selectivity of the antiport arises from the substrate binding step. In contrast to homologous E. coli NhaA, transport activity remains high at pH values above 8.5. The antiporter from S. Typhimurium is a promising candidate for combined structural and functional studies to contribute to the elucidation of the mechanism of pH-dependent Na+/H+ antiporters and to provide insights in the molecular basis of species-specific growth and survival strategies
IDO1 is highly expressed in macrophages of patients in advanced tumour stages of oral squamous cell carcinoma
Purpose Strategies for Indolamine-2,3-dioxygenase 1 (IDO1) inhibition in cancer immunotherapy once produced encouraging results, but failed in clinical trials. Recent evidence indicates that immune cells in the tumour microenvironment,
especially macrophages, contribute to immune dysregulation and therefore might play a critical role in drug resistance.
Methods In this study, we investigated the signifcance of IDO1 expressing immune cells in primary tumours and corresponding lymph node metastases (LNMs) in oral squamous cell carcinoma (OSCC) by immunohistochemistry. The link
between IDO1 and macrophages was investigated by fow cytometry in tumour tissue, healthy adjacent tissue and peripheral
blood mononuclear cells (PBMCs). IDO1 activity (measured as Kynurenine/Tryptophan ratio) was assessed by ELISAs.
Results High IDO1 expression in tumour-infltrating immune cells was signifcantly correlated with advanced stages [Spearman’s rank correlation (SRC), p=0.027] and reduced progression-free survival (multivariate Cox regression, p=0.034).
IDO1 was signifcantly higher expressed in PBMCs of patients in advanced stages than in healthy controls (ANOVA, p<0.05)
and IDO1+ macrophages were more abundant in intratumoural areas than peritumoural (t test, p<0.001). IDO1 expression
in PBMCs was signifcantly correlated with IDO1 activity in serum (SRC, p<0.05). IDO1 activity was signifcantly higher
in patients with LNMs (t test, p<0.01).
Conclusion All in all, IDO1 expressing immune cells, especially macrophages, are more abundant in advanced stages of
OSCC and are associated with reduced progression-free survival. Further investigations are needed to explore their role
in local and systemic immune response. The IDO1 activity might be a suitable biomarker of metastasis in OSCC patients
- …