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  • Author: M. Hörmann, x
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Wir präsentieren ein Verfahren, das als Teil des visuellen Lokalisationssystems eines mobilen Roboters dessen Position ohne eine vorab gegebene Karte bestimmen kann. Es erhält von einem Bildverarbeitungsmodul, das nicht Gegenstand dieses Artikels ist, die Bildpositionen punktförmiger Umgebungsmerkmale, sogenannter Landmarken. Aus den daraus resultierenden Winkelmessungen und der Odometrie bildet es ein Netz von unscharfen räumlichen Beziehungen, das als Graph repräsentiert wird. Die Beziehungen werden metrisch auf den Kanten angegeben. Die Unschärfe wird hierbei mengenbasiert mit Ellipsoiden und Hyperboloiden modelliert. Für die Lokalisation löst dieser Ansatz die Konsistenzprobleme, die beim autonomen Aufbau weiträumiger Karten entstehen.

Abstract

In modern pharmaceutical research, microarrays for the analysis of differential gene expression are some of the most valuable tools for the characterization of novel compounds and their biological activity. Moreover, basic clinical research in medicine has benefited tremendously from this rapid development leading to the discovery of new pathophysiological concepts for numerous diseases and to an increased significance for molecular genetic approaches by the characterization of molecular signatures (synonymous for gene expression profile, gene profiling, expression profiling) of diseases or diseased tissues. Extensive data already exist particularly in oncology, where gene profiling has been brought into patient care. For the clinical application of innovative diagnostic procedures, the quest for disease prognosis as well as optimized therapies usually have the highest priority. Particularly in this field, gene expression profiling could help to improve and supplement phenotypic diagnostics and classical laboratory analytics. It is foreseeable that the analysis of a limited number of diagnostically relevant targets and their quantitative measurement by real-time PCR, a reliable technique for this kind of analyses, would suffice. For the identification of diagnostically relevant targets, the research community currently has access to a number of whole-genome arrays or topic-specific arrays, which provide information about the up- or down-regulation of transcripts. These techniques are primarily based upon hybridization of mRNA or cDNA to capture probes and the semi-quantitative measurement of the signal intensity. This article demonstrates the workflow required when setting up a gene expression laboratory for routine analytics in biomedical research and diagnostics.

Incubation under sublethal high pressure (50 MPa) allowed the isolation of a piezotolerant mutant of Lactobacillus sanfranciscensis. Compared to the wild type this strain showed faster growth at 50 MPa and an altered temperature-dependent growth at ambient pressure. Additionally, an altered antibiotic resistance pattern was detected. To address the molecular basis of the mutation the genotypic characterisation was focused on alterations of ribosomal components. Northern analysis using ssrA (transfer mRNA) as probe revealed a constitutive overexpression in the mutant. A 2.2 fold induction after pressure shock and increased pressure sensitivity of a ssrA-insertional mutant of L. sanfranciscensis indicate the tmRNA as genetic determinant of a piezotolerance response in the wild type. Thus, we propose trans-translation and peptide tagging, processes that promote recycling of stalled ribosomes and prevent accumulation of abortively synthesised polypeptides to be involved in combating high-pressure damage and conferring moderate piezotolerance.

Abstract

Background:

Antibodies directed against dsDNA are a highly specific diagnostic marker for the presence of systemic lupus erythematosus and of particular importance in its diagnosis. To assess anti-dsDNA antibodies, the Crithidia luciliae-based indirect immunofluorescence test (CLIFT) is one of the assays considered to be the best choice. To overcome the drawback of subjective result interpretation that inheres indirect immunofluorescence assays in general, automated systems have been introduced into the market during the last years. Among these systems is the EUROPattern Suite, an advanced automated fluorescence microscope equipped with different software packages, capable of automated pattern interpretation and result suggestion for ANA, ANCA and CLIFT analysis.

Methods:

We analyzed the performance of the EUROPattern Suite with its automated fluorescence interpretation for CLIFT in a routine setting, reflecting the everyday life of a diagnostic laboratory. Three hundred and twelve consecutive samples were collected, sent to the Central Diagnostic Laboratory of the Maastricht University Medical Centre with a request for anti-dsDNA analysis over a period of 7 months.

Results:

Agreement between EUROPattern assay analysis and the visual read was 93.3%. Sensitivity and specificity were 94.1% and 93.2%, respectively. The EUROPattern Suite performed reliably and greatly supported result interpretation.

Conclusions:

Automated image acquisition is readily performed and automated image classification gives a reliable recommendation for assay evaluation to the operator. The EUROPattern Suite optimizes workflow and contributes to standardization between different operators or laboratories.