163 research outputs found

    Integriertes Performance-Monitoring von SOA-Anwendungen

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    Der Beitrag stellt einen Ansatz zur Integration von Performance-Monitoring-Aspekten in serviceorientierte Architekturen (SOAs) vor. Der Fokus liegt hierbei auf der konsistenten Instrumentierung bereits existierender SOA-Dienste. Hierfür wird ein im Rahmen des Projekts Performance Management of Enterprise Applications (PerManEntA) entwickeltesWerkzeug vorgestellt, das eine modellbasierte Instrumentierungsunterstützung mit Hilfe grafischer Marker vorsieht. Der Ansatz ermöglicht die Verwendung einheitlicher Monitoringschnittstellen und -funktionalität für alle in einer SOA kooperierenden Dienste und die konsistente Instrumentierung mit Hilfe teilautomatisierter, werkzeuggestützter Instrumentierung und Quellcodegenerierung. Im Ausblick werden Möglichkeiten zur Integration mit unterschiedlichen Ansätzen für das Service Level Management im SOA-Kontext aufgezeigt

    HuSiDa—the human siRNA database: an open-access database for published functional siRNA sequences and technical details of efficient transfer into recipient cells

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    Small interfering RNAs (siRNAs) have become a standard tool in functional genomics. Once incorporated into the RNA-induced silencing complex (RISC), siRNAs mediate the specific recognition of corresponding target mRNAs and their cleavage. However, only a small fraction of randomly chosen siRNA sequences is able to induce efficient gene silencing. In common laboratory practice, successful RNA interference experiments typically require both, the labour and cost-intensive identification of an active siRNA sequence and the optimization of target cell line-specific procedures for optimal siRNA delivery. To optimize the design and performance of siRNA experiments, we have established the human siRNA database (HuSiDa). The database provides sequences of published functional siRNA molecules targeting human genes and important technical details of the corresponding gene silencing experiments, including the mode of siRNA generation, recipient cell lines, transfection reagents and procedures and direct links to published references (PubMed). The database can be accessed at http://www.human-siRNA-database.net. We used the siRNA sequence information stored in the database for scrutinizing published sequence selection parameters for efficient gene silencing

    Effects of RAL signal transduction in KRAS- and BRAF-mutated cells and prognostic potential of the RAL signature in colorectal cancer

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    Our understanding of oncogenic signaling pathways has strongly fostered current concepts for targeted therapies in metastatic colorectal cancer. The RALA pathway is novel candidate due to its independent role in controlling expression of genes downstream of RAS. We compared RALA GTPase activities in three colorectal cancer cell lines by GTPase pull-down assay and analyzed the transcriptional and phenotypic effects of transient RALA silencing. Knocking-down RALA expression strongly diminished the active GTP-bound form of the protein. Proliferation of KRAS mutated cell lines was significantly reduced, while BRAF mutated cells were mostly unaffected. By microarray analysis we identified common genes showing altered expression upon RALA silencing in all cell lines. None of these genes were affected when the RAF/MAPK or PI3K pathways were blocked. To investigate the potential clinical relevance of the RALA pathway and its associated transcriptome, we performed a meta-analysis interrogating progression-free survival of colorectal cancer patients of five independent data sets using Cox regression. In each dataset, the RALA-responsive signature correlated with worse outcome. In summary, we uncovered the impact of the RAL signal transduction on genetic program and growth control in KRAS- and BRAF-mutated colorectal cells and demonstrated prognostic potential of the pathway-responsive gene signature in cancer patients

    Ein implantierbares Telemetriesystem zur Impedanzspektroskopie

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    Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Die kontinuierliche Überwachung des intrakorporalen Zustandes von Geweben beispielsweise zur Erkennung ischämischer Vorgänge nach gefäßchirurgischen Eingriffen oder im Rahmen der Rejektionsdiagnostik läßt sich durch bisher vorhandene Meßsysteme nur bedingt erreichen. Speziell die direkte Erfassung sensitiver Gewebeparameter über einen längeren Zeitraum ohne Belastung für den Patienten stellt in diesem Zusammenhang ein Problem dar. In der nachfolgenden Arbeit wird das Konzept eines implantierbaren Telemetriesystems vorgestellt, das die Bewertung des Gewebezustandes über die Messung der frequenzabhängigen Bioimpedanz ermöglicht. Besondere Beachtung wird der Auslegung und Umsetzung der einzelnen Systemkomponenten sowie der Vorstellung erster in vitro Messungen zur Evaluierung des Meßsystems geschenkt

    Discovery and Validation of Novel Biomarkers for Detection of Epithelial Ovarian Cancer

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    Detection of epithelial ovarian cancer (EOC) poses a critical medical challenge. However, novel biomarkers for diagnosis remain to be discovered. Therefore, innovative approaches are of the utmost importance for patient outcome. Here, we present a concept for blood-based biomarker discovery, investigating both epithelial and specifically stromal compartments, which have been neglected in search for novel candidates. We queried gene expression profiles of EOC including microdissected epithelium and adjacent stroma from benign and malignant tumours. Genes significantly differentially expressed within either the epithelial or the stromal compartments were retrieved. The expression of genes whose products are secreted yet absent in the blood of healthy donors were validated in tissue and blood from patients with pelvic mass by NanoString analysis. Results were confirmed by the comprehensive gene expression database, CSIOVDB (Ovarian cancer database of Cancer Science Institute Singapore). The top 25% of candidate genes were explored for their biomarker potential, and twelve were able to discriminate between benign and malignant tumours on transcript levels (p < 0.05). Among them T-cell differentiation protein myelin and lymphocyte (MAL), aurora kinase A (AURKA), stroma-derived candidates versican (VCAN), and syndecan-3 (SDC), which performed significantly better than the recently reported biomarker fibroblast growth factor 18 (FGF18) to discern malignant from benign conditions. Furthermore, elevated MAL and AURKA expression levels correlated significantly with a poor prognosis. We identified promising novel candidates and found the stroma of EOC to be a suitable compartment for biomarker discovery

    Isolation and characterization of Chinese hamster cells defective in cell-cell coupling via gap junctions

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    Chinese hamster Wg3-h-o cells which were descended from DON cells have been mutagenized and selected for derivatives defective in metabolic cooperation via gap junctions (i.e., mec&#8722;). The selection protocol included four consecutive cycles of cocultivating mutagenized cells, deficient in hypoxanthine phosphoribosyltransferase (HPRT) and wild-type cells in the presence of thioguanine (cf Slack, C, Morgan, R H M & Hooper, M L, Exp cell res 117 (1978) 195-205) [8]. We carried out the last two selection cycles in the presence of 1 mM dibutyryl cyclic adenosine monophosphate (db-cAMP). The isolated Chinese hamster CI-4 cells which expressed the mec&#8722; phenotype most stringently showed the following characteristics: 1. 1. In standard culture medium no cell-cell coupling was detected among CI-4 cells when assayed by injections of the fluorescent dye Lucifer yellow or by electrical measurements. Between 73 and 100% of the mec+ parental cells were coupled under these conditions. Up to 14% positive contacts were found between CI-4 cells and Chinese hamster Don cells (mec+). Confluent CI-4 cells grown in the presence of 1 mM db-cAMP showed 9% coupled cells. 2. 2. No gap junction plaques were found on electron micrographs of freeze-fractured, confluent CI-4 cells. The mec+ parental cells showed small gap junction plaques (0.013% of the total cell surface analyzed). 3. 3. CI-4 cells exhibited 16% positive contacts and the parental Wg3-h-o cells showed 92% positive contacts in autoradiographic measurements of metabolic cooperation with DON cells. On an extracellular matrix, prepared from normal embryonic fibroblasts, metabolic cooperation between CI-4 and DON cells was autoradiographically measured to be 68%. Other cells of spontaneous mec&#8722; phenotype (for example mouse L cells or human fibrosarcoma HT1080 cells) also appeared to exhibit increased metabolic cooperation when grown on an extracellular matrix and assayed by autoradiographic measurements. When tested by Lucifer yellow injections, however, only very few positive contacts were found for CI-4/DON cell pairs and no positive contacts were found among mouse L cells grown on an extracellular matrix. 4. 4. The mec&#8722; defect in the genome of CI-4 cells was cured in somatic cell hybrids with mouse embryonic fibroblasts or with mouse embryonal carcinoma cells. The results of isozyme and karyotype studies of mec&#8722;, as well as mec+ somatic cell hybrids suggest that mouse chromosome 16 may be involved in complementation of the mec&#8722; defect

    IC50: an unsuitable measure for large-sized prostate cancer spheroids in drug sensitivity evaluation

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    Preclinical models of tumors have the potential to become valuable tools for commercial drug research and development, and 3D culture systems are gaining traction in this area, particularly in prostate cancer (PCa) research. However, nearly all 3D drug design and screening assessments are based on 2D experiments, suggesting limitations of 3D drug testing. To simulate the natural response of human cells to the drug, we detected the half-maximal inhibitory concentration (IC50) changes of 2D/3D LNCaP cells in the drug docetaxel, as well as the sensitivity of different morphologies of 2D/3D LNCaP to docetaxel treatment. In contrast to 2D LNCaP cells, the evaluation of LNCaP spheroids’ susceptibility to treatment was more complicated; the fitness of IC50 curves of 2D and 3D tumor cell preclinical models differs significantly. IC50 curves were unsuitable for large-sized LNCaP spheroids. More evaluation indexes (such as max inhibition) and experiments (such as spheroids formation) should be explored and performed to evaluate the susceptibility systematically
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