Gene expression noise in a complex artificial toxin expression system.

Gene expression is an intrinsically stochastic process. Fluctuations in transcription and translation lead to cell-to-cell variations in mRNA and protein levels affecting cellular function and cell fate. Here, using fluorescence time-lapse microscopy, we quantify noise dynamics in an artificial operon in Escherichia coli, which is based on the native operon of ColicinE2, a toxin.

Blocking-Free and Substrate-Independent Serological Microarray Immunoassays.

In bioanalytical applications, many coating strategies have been established for so-called "blocking" of the surfaces. However, most of the procedures developed so far require additional processing steps for surface blocking and small variations in the blocking efficiency result in increased background noise, which lowers the overall sensitivity of an assay. In this study, we demonstrate the preparation of a bioanalytical surface with a thin film of a photo-cross-linkable copolymer that is transformed photochemically into a surface-attached hydrogel network.

CsrA and its regulators control the time-point of ColicinE2 release in Escherichia coli.

The bacterial SOS response is a cellular reaction to DNA damage, that, among other actions, triggers the expression of colicin - toxic bacteriocins in Escherichia coli that are released to kill close relatives competing for resources. However, it is largely unknown, how the complex network regulating toxin expression controls the time-point of toxin release to prevent premature release of inefficient protein concentrations. Here, we study how different regulatory mechanisms affect production and release of the bacteriocin ColicinE2 in Escherichia coli.

Retrospective angiographic study to determine the effect of atherosclerotic stenoses of upstream arteries on the degree of atherosclerosis in distal vascular territories.

Objective: Experimental coarctation of the aorta prevents the development of downstream atherosclerosis. The aim of this study was to find out whether or not atherosclerotic stenoses protect distal vascular territories from developing atherosclerosis in humans.

Design And Setting: A total of 2125 vascular segments from angiographies of 101 patients were evaluated by calculating the maximum degree of stenosis (NASCET criteria), the degree of calcification, the degree of collaterals and the Friesinger score.

Amount of colicin release in Escherichia coli is regulated by lysis gene expression of the colicin E2 operon.

The production of bacteriocins in response to worsening environmental conditions is one means of bacteria to outcompete other microorganisms. Colicins, one class of bacteriocins in Escherichia coli, are effective against closely related Enterobacteriaceae. Current research focuses on production, release and uptake of these toxins by bacteria.

Immediate and heterogeneous response of the LiaFSR two-component system of Bacillus subtilis to the peptide antibiotic bacitracin.

Background: Two-component signal transduction systems are one means of bacteria to respond to external stimuli. The LiaFSR two-component system of Bacillus subtilis consists of a regular two-component system LiaRS comprising the core Histidine Kinase (HK) LiaS and the Response Regulator (RR) LiaR and additionally the accessory protein LiaF, which acts as a negative regulator of LiaRS-dependent signal transduction. The complete LiaFSR system was shown to respond to various peptide antibiotics interfering with cell wall biosynthesis, including bacitracin.

Universal nucleic acid sequence-based amplification for simultaneous amplification of messengerRNAs and microRNAs.

A universal NASBA assay is presented for simultaneous amplification of multiple microRNA (miRNA) and messengerRNA (mRNA) sequences. First, miRNA and mRNA sequences are reverse transcribed using tailed reverse transcription primer pairs containing a gene-specific and an non-specific region. For reverse transcription of small miRNA molecules a non-specific region is incorporated into a structured stem-loop reverse transcription primer.

Discrimination of Escherichia coli strains using glycan cantilever array sensors.

Carbohydrate-based sensors, that specifically detect sugar binding molecules or cells, are increasingly important in medical diagnostic and drug screening. Here we demonstrate that cantilever arrays functionalized with different mannosides allow the real-time detection of several Escherichia coli strains in solution. Cantilever deflection is thereby dependent on the bacterial strain studied and the glycan used as the sensing molecule.

Simple one-step process for immobilization of biomolecules on polymer substrates based on surface-attached polymer networks.

For the miniaturization of biological assays, especially for the fabrication of microarrays, immobilization of biomolecules at the surfaces of the chips is the decisive factor. Accordingly, a variety of binding techniques have been developed over the years to immobilize DNA or proteins onto such substrates. Most of them require rather complex fabrication processes and sophisticated surface chemistry.

Cantilever array sensors detect specific carbohydrate-protein interactions with picomolar sensitivity.

Advances in carbohydrate sequencing technologies have revealed the tremendous complexity of the glycome. This complexity reflects the structural and chemical diversity of carbohydrates and is greater than that of proteins and oligonucleotides. The next step in understanding the biological function of carbohydrates requires the identification and quantification of carbohydrate interactions with other biomolecules, in particular, with proteins.

Nucleic acid sequence-based amplification in formalin-fixed and paraffin-embedded breast-cancer tissues.

Aim: To evaluate the nucleic acid sequence-based amplification (NASBA) technique to amplify mRNA isolated from formalin-fixed and paraffin-embedded (FFPE) breast-cancer tissues.

Methods: RNA was extracted from archived, 10-year-old FFPE tissues, and selected genes, namely ribosomal protein S18 (RPS18), epidermal growth factor receptor 2 (HER2), estrogen receptor alpha (ERα), Y box binding protein (YBX-1), matrix metallopeptidase 11 (MMP11), caspase 8 (CASP8) and superoxide dismutase 2 (SOD2), were amplified by NASBA.

Results: Despite strong degradation of the template, RNA amplification of all tested genes resulted in strong hybridisation signals.

Microarray-based amplification and detection of RNA by nucleic acid sequence based amplification.

Nucleic acid sequence based amplification (NASBA) is a versatile in vitro nucleic acid amplification method. In this work, RNA amplification and labeling by NASBA and microarray analysis are combined in a one-step process. The NASBA reaction is performed in direct contact with capture probes.

Evidence for RPE65-independent vision in the cone-dominated zebrafish retina.

An enzyme-based cyclic pathway for trans to cis isomerization of the chromophore of visual pigments (11-cis-retinal) is intrinsic to vertebrate cone and rod vision. This process, called the visual cycle, is mostly characterized in rod-dominated retinas and essentially depends on RPE65, an all-trans to 11-cis-retinoid isomerase. Here we analysed the role of RPE65 in zebrafish, a species with a cone-dominated retina.