A cell-based assay system for activators of the environmental cell stress response.

Improved health span and lifespan extension in a wide phylogenetic range of species is associated with the induction of the environmental cell stress response through a signalling pathway regulated by the transcription factor Nrf2. Phytochemicals which stimulate this response may form part of therapeutic interventions which stimulate endogenous cytoprotective mechanisms, thereby delaying the onset of age-related diseases and promoting healthy ageing in humans. In order to identify compounds that activate the Nrf2 pathway, a cell-based reporter system was established in HepG2 cells using a luciferase reporter gene under the control of the Nqo1 promoter. Sulforaphane, an isothiocyanate derived from cruciferous vegetables and a known activator of the Nrf2 pathway, was used to validate the reporter system. The transfected cell line HepG2 C1 was subsequently used to screen natural product libraries. Five compounds were identified as activating the bioluminescent reporter by greater than 5-fold. The two most potent compounds, MBC20 and MBC37, were further characterised and shown to stimulate endogenous cytoprotective gene and protein expression. The bioluminescent reporter system will allow rapid, in vitro identification of novel compounds that have the potential to improve health span through activation of the environmental stress response.

Folate deficiency promotes differentiation of vascular smooth muscle cells without affecting the methylation status of regulated genes.

Elevated serum homocysteine, an intermediate of cellular one-carbon metabolism, is an independent risk factor for cardiovascular disease (CVD). Folate deficiency increases serum homocysteine and may contribute to CVD progression. Vascular smooth muscle cells (VSMCs) regulate vascular contractility, but also contribute to repair processes in response to vascular injury. Nutritional deficiencies, like folate deficiency, are thought to impact on this phenotypic plasticity, possibly by epigenetic mechanisms. We have investigated the effect of folate deficiency on VSMCs in two cell culture systems representing early and late stages of smooth muscle cells differentiation. We find that folate deficiency promotes differentiation towards a more contractile phenotype as indicated by increased expression of respective marker genes. However, microarray analysis identified markers of striated muscle as the predominant gene expression change elicited by folate deficiency. These changes are not merely a reflection of cell cycle arrest, as foetal calf serum restriction or iron deficiency do not replicate the gene expression changes observed in response to folate deficiency. Folate deficiency only has a marginal effect on global DNA methylation. DNA methylation of CpG islands associated with genes regulated by folate deficiency remains unaffected. This supports our earlier findings in a mouse model system which also did not show any changes in global DNA methylation in response to folate and vitamin B6/B12 deficiency. These data suggest that folate deficiency enhances the expression of smooth muscle marker gene expression, promotes a shift towards a skeletal muscle phenotype, and does not regulate gene expression via DNA methylation.

Pulse Based Time-of-Flight Range Sensing.

Pulse-based Time-of-Flight (PB-ToF) cameras are an attractive alternative range imaging approach, compared to the widely commercialized Amplitude Modulated Continuous-Wave Time-of-Flight (AMCW-ToF) approach. This paper presents an in-depth evaluation of a PB-ToF camera prototype based on the Hamamatsu area sensor S11963-01CR. We evaluate different ToF-related effects, i.e., temperature drift, systematic error, depth inhomogeneity, multi-path effects, and motion artefacts. Furthermore, we evaluate the systematic error of the system in more detail, and introduce novel concepts to improve the quality of range measurements by modifying the mode of operation of the PB-ToF camera. Finally, we describe the means of measuring the gate response of the PB-ToF sensor and using this information for PB-ToF sensor simulation.

CD13/aminopeptidase N is a negative regulator of mast cell activation.

Antigen-induced mast cell (MC) activation via cross-linking of IgE-bound high-affinity receptors for IgE (FcεRI) underlies type I allergy and anaphylactic shock. Comprehensive knowledge of FcεRI regulation is thus required. We have identified a functional interaction between FcεRI and CD13 in murine MCs. Antigen-triggered activation of IgE-loaded FcεRI results in cocapping and cointernalization of CD13 and equivalent internalization rates of up to 40%. Cointernalization is not unspecific, because ligand-driven KIT internalization is not accompanied by CD13 internalization. Moreover, antibody-mediated cross-linking of CD13 causes IL-6 production in an FcεRI-dependent manner. These data are indicative of a functional interaction between FcεRI and CD13 on MCs. To determine the role of this interaction, CD13-deficient bone marrow-derived MCs (BMMCs) were analyzed. Intriguingly, antigen stimulation of CD13-deficient BMMCs results in significantly increased degranulation and proinflammatory cytokine production compared to wild-type cells. Furthermore, in a low-dose model of passive systemic anaphylaxis, antigen-dependent decrease in body temperature, reflecting the anaphylactic reaction, is substantially enhanced by the CD13 inhibitor bestatin (-5.9 ± 0.6°C) and by CD13 deficiency (-8.8 ± 0.6°C) in contrast to controls (-1.2 ± 1.97°C). Importantly, bestatin does not aggravate anaphylaxis in CD13-deficient mice. Thus, we have identified CD13 as a novel negative regulator of MC activation in vitro and in vivo-Zotz, J. S., Wölbing, F., Lassnig, C., Kauffmann, M., Schulte, U., Kolb, A., Whitelaw, B., Müller, M., Biedermann, T., Huber, M. CD13/aminopeptidase N is a negative regulator of mast cell activation.

Quantified, Interactive Simulation of AMCW ToF Camera Including Multipath Effects.

In the last decade, Time-of-Flight (ToF) range cameras have gained increasing popularity in robotics, automotive industry, and home entertainment. Despite technological developments, ToF cameras still suffer from error sources such as multipath interference or motion artifacts. Thus, simulation of ToF cameras, including these artifacts, is important to improve camera and algorithm development. This paper presents a physically-based, interactive simulation technique for amplitude modulated continuous wave (AMCW) ToF cameras, which, among other error sources, includes single bounce indirect multipath interference based on an enhanced image-space approach. The simulation accounts for physical units down to the charge level accumulated in sensor pixels. Furthermore, we present the first quantified comparison for ToF camera simulators. We present bidirectional reference distribution function (BRDF) measurements for selected, purchasable materials in the near-infrared (NIR) range, craft real and synthetic scenes out of these materials and quantitatively compare the range sensor data.

Imaging in scattering media using correlation image sensors and sparse convolutional coding.

Correlation image sensors have recently become popular low-cost devices for time-of-flight, or range cameras. They usually operate under the assumption of a single light path contributing to each pixel. We show that a more thorough analysis of the sensor data from correlation sensors can be used can be used to analyze the light transport in much more complex environments, including applications for imaging through scattering and turbid media. The key of our method is a new convolutional sparse coding approach for recovering transient (light-in-flight) images from correlation image sensors. This approach is enabled by an analysis of sparsity in complex transient images, and the derivation of a new physically-motivated model for transient images with drastically improved sparsity.

Site specific insertion of a transgene into the murine α-casein (CSN1S1) gene results in the predictable expression of a recombinant protein in milk.

Gene loci of highly expressed genes provide ideal sites for transgene expression. Casein genes are highly expressed in mammals leading to the synthesis of substantial amounts of casein proteins in milk. The α-casein (CSN1S1) gene has assessed as a site of transgene expression in transgenic mice and a mammary gland cell line. A transgene encoding an antibody light chain gene (A1L) was inserted into the α-casein gene using sequential homologous and site-specific recombination. Expression of the inserted transgene is directed by the α-casein promoter, is responsive to lactogenic hormone activation, leads to the synthesis of a chimeric α-casein/A1L transgene mRNA, and secretion of the recombinant A1L protein into milk. Transgene expression is highly consistent in all transgenic lines, but lower than that of the α-casein gene (4%). Recombinant A1L protein accounted for 0.5% and 1.6% of total milk protein in heterozygous and homozygous transgenic mice, respectively. The absence of the α-casein protein in homozygous A1L transgenic mice leads to a reduction of total milk protein and delayed growth of the pups nursed by these mice. Overall, the data demonstrate that the insertion of a transgene into a highly expressed endogenous gene is insufficient to guarantee its abundant expression.

Maternal α-casein deficiency extends the lifespan of offspring and programmes their body composition.

Early nutrition has significant effects on physiological outcomes during adult life. We have analysed the effect of maternal α-casein (CSN1S1) deficiency on the physiological fate of dams and their offspring. α-casein deficiency reduces maternal milk protein concentration by more than 50% and attenuates the growth of pups to 27% (p < 0.001) of controls at the point of weaning. This is associated with a permanent reduction in adult body weight (- 31% at 25 weeks). Offspring nursed by α-casein deficient dams showed a significantly increased lifespan (+ 20%, χ2: 10.6; p = 0.001). Liver transcriptome analysis of offspring nursed by α-casein deficient dams at weaning revealed gene expression patterns similar to those found in dwarf mice (reduced expression of somatotropic axis signalling genes, increased expression of xenobiotic metabolism genes). In adult mice, the expression of somatotropic axis genes returned to control levels. This demonstrates that, in contrast to dwarf mice, attenuation of the GH-IGF signalling axis in offspring nursed by α-casein deficient dams is transient, while the changes in body size and lifespan are permanent. Offspring nursed by α-casein deficient dams showed permanent changes in body composition. Absolute and relative adipose tissue weights (p < 0.05), the percentage of body fat (p < 0.001) as well as adipocyte size in epididymal white adipose tissue are all reduced. Serum leptin levels were 25% of those found in control mice (p < 0.001). Liver lipid content and lipid composition were significantly altered in response to postnatal nutrition. This demonstrates the nutrition in early life programmes adult lipid metabolism, body composition and lifespan.

Improved synthesis of cyclic tertiary allylic alcohols by asymmetric 1,2-addition of AlMe3 to enones.

The development of an improved protocol for the enantioselective Rh(I) /binap-catalysed 1,2-addition of AlMe3 to cyclic enones is reported. (31)P NMR analysis of the reaction revealed that the catalyst in its resting state is a chloride-bridged dimer. This insight led to the use of AgBF4 as an additive for in situ activation of the dimeric precatalyst. Thus, the catalyst loading can now be reduced to only 1 mol% with respect to rhodium. Various 5-7-membered cyclic enones can be transformed into tertiary allylic alcohols with excellent levels of enantioselectivity and high yields. The obtained products are versatile synthetic building blocks, shown by a highly enantioselective formal total synthesis of the pheromone (-)-frontalin as well as formation of a bicyclic lactone that has the core structure of the natural flavour component "wine lactone".

Mammary gland development is delayed in mice deficient for aminopeptidase N.

Development of the mammary gland requires the coordinated action of proteolytic enzymes during two phases of remodelling. Firstly, new ducts and side-branches thereof need to be established during pregnancy to generate an extensive ductal tree allowing the secretion and transport of milk. A second wave of remodelling occurs during mammary involution after weaning. We have analysed the role of the cell surface protease aminopeptidase N (Anpep, APN, CD13) during these processes using Anpep deficient and Anpep over-expressing mice. We find that APN deficiency significantly delays mammary gland morphogenesis during gestation. The defect is characterised by a reduction in alveolar buds and duct branching at mid-pregnancy. Conversely over-expression of Anpep leads to accelerated ductal development. This indicates that Anpep plays a critical role in the proteolytic remodelling of mammary tissue during adult mammary development.

Behaviour of postnatally growth-impaired mice during malnutrition and after partial weight recovery.

OBJECTIVES: Early malnutrition is a highly prevalent condition in developing countries. Different rodent models of postnatal early malnutrition have been used to approach the subject experimentally, inducing early malnutrition by maternal malnutrition, temporal maternal separation, manipulation of litter size or the surgical nipple ligation to impair lactation. Studies on the behaviour of (previously) malnourished animals using animal models have produced sometimes contradictory results regarding the effects of early postnatal malnutrition and have been criticized for introducing potential confounding factors. The present paper is a first report on the behavioural effects of early malnutrition induced by an alternative approach: mice nursed by α-casein-deficient knockout dams showed a severe growth delay during early development and substantial catch-up growth after weaning when compared with animals nursed by wild-type females. METHODS: Established behavioural tests were used to study the consequences of early postnatal malnutrition on mouse pups at weaning and after partial weight recovery. RESULTS: Despite the impaired growth, the only behavioural difference between malnourished and normally growing animals was found in exploratory behaviour during acute malnutrition at the time of weaning. After partial catch-up in weight early protein malnourished animals showed no indication of lasting effects on general activity, emotionality and exploration, memory, and pain reactivity. DISCUSSION: These results suggest that the role of early nutrition on behavioural development after recovery in animal models may have been overestimated. Further careful examination of this animal model in terms of maternal care and offspring behaviour will be necessary to confirm if mice nursed by α-casein-deficient dams offer an alternative to existing models while eliminating potential confounding factors.

Influence of rubber dam on objective and subjective parameters of stress during dental treatment of children and adolescents - a randomized controlled clinical pilot study.

BACKGROUND: Rubber dam is recommended for isolating the working field during adhesive dentistry procedures; however, dentists often omit rubber dam, particularly in paediatric dentistry, supposing that it would stress the patient. AIM: The aim of this study was to evaluate stress parameters during a standardized dental treatment procedure performed with or without rubber dam. The treatment time was measured as a secondary outcome variable. DESIGN: This study was designed as a randomized, controlled, clinical study with 72 patients (6-16 years; mean age, 11.1). During standardized fissure sealing procedures, objective parameters of stress (e.g., skin resistance, breath rate) were recorded. The operator's stress level was measured by pulse rate. Subjective pain (patients) and stress perception (operator) were evaluated by an interview. RESULTS: The breath rate was significantly (P<0.05) lower and the skin resistance level was significantly higher during treatment with rubber dam compared to the control group. Subjective pain perception was significantly lower for the test group. The treatment time needed for the fissure sealing procedure was 12.4% less in the test group. CONCLUSION: Isolation with rubber dam caused less stress in children and adolescents compared to relative isolation with cotton rolls if applied by an experienced dentist.

Anatomically Integrated In-Place Visualization of Patient Data for Cooperative Tasks with a Case Study on a Neurosurgical Ward.

The workflow in modern hospitals entails that the medical treatment of a patient is distributed between several physicians and nurses. This leads to intensive cooperation, which takes place under particular time pressure and requires efficient conveyance of relevant patient-related medical data to colleagues. This requirement is difficult to achieve with traditional data representation approaches. In this paper, we introduce a novel concept of anatomically integrated in-place visualization designed to engage with cooperative tasks on a neurosurgical ward by using a virtual patient's body as spatial representation of visually encoded abstract medical data. Based on the findings of our field studies, we provide a set of formal requirements and procedures for this kind of visual encoding. Moreover, we implemented a prototype on a mobile device that supports the diagnosis of spinal disc herniation and has been evaluated by 10 neurosurgeons. The physicians have assessed the proposed concept as beneficial, especially emphasizing the advantages of the anatomical integration such as intuitiveness and a better data availability due to providing all information at a glance. Particularly, four of nine respondents have stressed solely benefits of the concept, other four have mentioned benefits with some limitations and only one person has seen no benefits.

Recombinase mediated cassette exchange into genomic targets using an adenovirus vector.

Recombinase mediated cassette exchange (RMCE) is a process in which site-specific recombinases exchange one gene cassette flanked by a pair of incompatible target sites for another cassette flanked by an identical pair of sites. Typically one cassette is present in the host genome, whereas the other gene cassette is introduced into the host cell by chemical or biological means. We show here that the frequency of cassette exchange is dependent on the relative and absolute quantities of the transgene cassette and the recombinase. We were able to successfully modify genomic targets not only by electroporation or chemically mediated gene transfer but also by using an adenovirus vector carrying both the transgene cassette to be inserted and the recombinase coding region. RMCE proceeds efficiently in cells in which the adenovirus vector is able to replicate. In contrast, insufficient quantities of the transgene cassette are produced in cells in which the virus cannot replicate. Additional transfection of the transgene cassette significantly enhances the RMCE frequency. This demonstrates that an RMCE system in the context of a viral vector allows the site directed insertion of a transgene into a defined genomic site.

Perception and Quantization Model for Periodic Contour Modifications.

Periodic, wave-like modifications of 2D shape contours are often applied to convey quantitative data via images. However, to the best of our knowledge, there has been no in-depth investigation of the perceptual uniformity and legibility of these kind of approaches. In this paper, we design and perform a user study to evaluate the perception of periodic contour modifications related to their geometry and colour. Based on the study results, we statistically derive a perceptual model, which demonstrates a mainly linear stimulus-to-perception relationship for geometric and colour amplitude and a close-to-quadratic relationship for the respective frequencies, with a rather negligible dependency on the waveform. Furthermore, analyzing the distribution of perceived magnitudes and the overlapping of the respective 50% confidence intervals, we extract distinguishable, visually equidistant quantization levels for each contour-related visual variable. Moreover, we give first insights into the perceptual dependency between amplitude and frequency, and propose a scheme for transferring our model to glyphs with different size, which preserves the distinguishability and the visual equidistance. This work is seen as a first step towards a comprehensive understanding of the perception of periodic contour modifications in image-based visualizations.

A Generic Framework for Depth Reconstruction Enhancement.

We propose a generic depth-refinement scheme based on GeoNet, a recent deep-learning approach for predicting depth and normals from a single color image, and extend it to be applied to any depth reconstruction task such as super resolution, denoising and deblurring, as long as the task includes a depth output. Our approach utilizes a tight coupling of the inherent geometric relationship between depth and normal maps to guide a neural network. In contrast to GeoNet, we do not utilize the original input information to the backbone reconstruction task, which leads to a generic application of our network structure. Our approach first learns a high-quality normal map from the depth image generated by the backbone method and then uses this normal map to refine the initial depth image jointly with the learned normal map. This is motivated by the fact that it is hard for neural networks to learn direct mapping between depth and normal maps without explicit geometric constraints. We show the efficiency of our method on the exemplary inverse depth-image reconstruction tasks of denoising, super resolution and removal of motion blur.

A Generative Model for Generic Light Field Reconstruction.

Recently deep generative models have achieved impressive progress in modeling the distribution of training data. In this work, we present for the first time a generative model for 4D light field patches using variational autoencoders to capture the data distribution of light field patches. We develop a generative model conditioned on the central view of the light field and incorporate this as a prior in an energy minimization framework to address diverse light field reconstruction tasks. While pure learning-based approaches do achieve excellent results on each instance of such a problem, their applicability is limited to the specific observation model they have been trained on. On the contrary, our trained light field generative model can be incorporated as a prior into any model-based optimization approach and therefore extend to diverse reconstruction tasks including light field view synthesis, spatial-angular super resolution and reconstruction from coded projections. Our proposed method demonstrates good reconstruction, with performance approaching end-to-end trained networks, while outperforming traditional model-based approaches on both synthetic and real scenes. Furthermore, we show that our approach enables reliable light field recovery despite distortions in the input.

Analysis of mammary specific gene locus regulation in differentiated cells derived by somatic cell fusion.

The transcriptional regulation of a gene is best analysed in the context of its normal chromatin surroundings. However, most somatic cells, in contrast to embryonic stem cells, are refractory to accurate modification by homologous recombination. We show here that it is possible to introduce precise genomic modifications in ES cells and to analyse the phenotypic consequences in differentiated cells by using a combination of gene targeting, site-specific recombination and somatic cell fusion. To provide a proof of principle, we have analysed the regulation of the casein gene locus in mammary gland cells derived from modified murine ES cells by somatic cell fusion. A beta-galactosidase reporter gene was inserted in place of the beta-casein gene and the modified ES cells, which do not express the reporter gene, were fused with the mouse mammary gland cell line HC11. The resulting cell clones expressed the beta-galactosidase gene to a similar extent and with similar hormone responsiveness as the endogenous gene. However, a reporter gene under the control of a minimal beta-casein promoter (encompassing the two consensus STAT5 binding sites which mediate the hormone response of the casein genes) was unable to replicate expression levels or hormone responsiveness of the endogenous gene when inserted into the same site of the casein locus. As expected, these results implicate sequences other than the STAT5 sites in the regulation of the beta-casein gene.

EMMPRIN (basigin/CD147) expression is not correlated with MMP activity during adult mouse mammary gland development.

Extracellular matrix metalloproteinase inducer (EMMPRIN/basigin/CD147) is a cell surface protein, which has been associated with the induction of matrix metalloproteinase (MMP) genes during cancer metastasis. EMMPRIN plays a role in a variety of physiological processes as is evident by the diverse deficiencies detectable in EMMPRIN knockout mice. We have analysed the role of EMMPRIN in the induction of MMP genes during mammary gland differentiation and involution. Co-transfection studies showed that EMMPRIN has diverse effects on MMP promoter activity in different mammary and non-mammary cell lines. Expression of EMMPRIN mRNA is enhanced markedly by insulin in a mammary gland cell line but appears to have no direct effect on MMP gene expression in these cells. Microarray analysis and quantitative PCR show that EMMPRIN is expressed throughout mammary gland differentiation in the mouse. Its expression decreases during early pregnancy and briefly after induction of mammary gland involution by litter removal. Immunohistochemical analysis shows that EMMPRIN expression is limited to the stromal compartment during pregnancy, whereas it is strongly expressed in the epithelium during lactation. In summary the data argue against a causal role for EMMPRIN for the induction of MMP gene expression during adult mammary gland development. These data therefore support a physiological role for EMMPRIN other than MMP induction in mammary gland biology.

A virus-neutralising antibody is not cytotoxic in vitro.

Hybridoma cell lines are characterized by a preferential loss of the heavy chain gene. This observation has led to the theory that the immunoglobulin heavy chain possesses an intrinsic cytotoxic activity in some cell types. We have generated transgenic mice expressing the heavy and light chain genes of the virus-neutralising antibody A1 carrying constant domains of the human gamma1 and kappa isotype. Heavy chain and light chain transgenes were under trancriptional control of identical promoter regions derived from the mammary gland specific ovine beta-lactoglobulin gene. The copy number of the heavy chain transgene was consistently lower than the copy number of the light chain gene in all lines of transgenic mice. Moreover, the light chain gene was expressed in significant excess of the heavy chain gene in the lactating mammary gland in all transgenic lines. In several transgenic lines, the differences in antibody expression were greater than could be explained by the differences in transgene copy number. One potential cause of this phenotype could be a cytotoxic effect of free heavy chain protein in embryonic cells (resulting in differences in copy number) or mammary epithelial cells (resulting in differences in transgene expression). We therefore directly assessed the effect of the expression of free A1 heavy chain protein in epithelial cell lines and in murine embryonic stem cells. However, full-length A1 heavy chain mRNA and protein could be expressed transiently and stably in both epithelial and embryonic stem cells and had no detectable effect on cell viability. Taken together, these findings argue against an inherent cytotoxicity of the free A1 heavy chain protein in epithelial or embryonic cells.