240 research outputs found

    Expression of TGF-β1 and β3 but not apoptosis factors relates to flow-induced aortic enlargement

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    BACKGROUND: Cell proliferation and apoptosis are both involved in arterial wall remodeling. Increase in blood flow induces arterial enlargement. The molecular basis of flow-induced remodeling in large elastic arteries is largely unknown. METHODS: An aortocaval fistula (ACF) model in rats was used to induce enlargement in the abdominal aorta. Aortic gene expression of transforming growth factors beta (TGF-β) and apoptosis-related factors was assessed at 1 and 3 days and 1, 2, 4, and 8 weeks. Expression levels were determined using a ribonuclease protection assay and western blotting. Cell proliferation and apoptosis were analyzed using BrdU incorporation and TUNEL techniques. RESULTS: Blood flow increased 5-fold immediately after ACF (P<0.05). Lumen diameter of the aorta was 30% and 75% larger at 2 and 8 weeks respectively than those of controls (P<0.05). mRNA levels of TGF-β1 and TGF-β3 increased after ACF, peaked at 3 days (P<0.05) and returned to normal level at 1 week and thereafter. Western blotting showed enhanced expression of TGF-β1 at 3 days and TGF-β3 at 1 and 3 days and 1 week (P<0.05). mRNA levels of Bcl-xS initially decreased at 1 day, 3 days and 1 week, followed a return to baseline level at 2 weeks. Cell proliferation was observed at all time points after ACF (P<0.001 vs. controls) with proliferation in endothelial cells more significant than smooth muscle cells. Apoptosis was not significant. CONCLUSIONS: Gene expression of TGF-β1 and β3 precedes arterial enlargement. Expression of apoptosis related factors is little regulated in the early stage of the flow-induced arterial remodeling

    Rotational velocities of A-type stars. III. Velocity distributions

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    Aim - In this work, a sample of vsini of B9 to F2-type main sequence single stars has been built from highly homogeneous vsini parameters determined for a large sample cleansed from objects presenting the Am and Ap phenomenon as well as from all known binaries. The aim is to study the distributions of rotational velocities in the mass range of A-type stars for normal single objects. Methods - Robust statistical methods are used to rectify the vsini distributions from the projection effect and the error distribution. The equatorial velocity distributions are obtained for an amount of about 1100 stars divided in six groups defined by the spectral type, under the assumption of randomly orientated rotational axes. Results - We show that late B and early A-type main-sequence stars have genuine bimodal distributions of true equatorial rotational velocities due probably to phenomena of angular momentum loss and redistribution the star underwent before reaching the main sequence. A striking lack of slow rotators is noticed among intermediate and late A-type stars. The bimodal-like shape of their true equatorial rotational velocity distributions could be due to evolutionary effects.Comment: 16 pages, 10 figures, accepted in A&

    Variants in pharmacokinetic transporters and glycemic response to metformin:A metgen meta-analysis

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    Therapeutic response to metformin, a first-line drug for type 2 diabetes (T2D), is highly variable, in part likely due to genetic factors. To date, metformin pharmacogenetic studies have mainly focused on the impact of variants in metformin transporter genes, with inconsistent results. To clarify the significance of these variants in glycemic response to metformin in T2D, we performed a large-scale meta-analysis across the cohorts of the Metformin Genetics Consortium (MetGen). Nine candidate polymorphisms in five transporter genes (organic cation transporter [OCT]1, OCT2, multidrug and toxin extrusion transporter [MATE]1, MATE2-K, and OCTN1) were analyzed in up to 7,968 individuals. None of the variants showed a significant effect on metformin response in the primary analysis, or in the exploratory secondary analyses, when patients were stratified according to possible confounding genotypes or prescribed a daily dose of metformin. Our results suggest that candidate transporter gene variants have little contribution to variability in glycemic response to metformin in T2D

    Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

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    The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is required so that the signal integration time can be as short as the Cherenkov light flash duration (a few ns). We have developed a readout board which samples waveforms of seven PMTs per board at a GHz rate. Since a GHz FADC has a high power consumption, leading to large heat dissipation, we adopted the analog memory ASIC "DRS4". The sampler has 1024 capacitors per channel and can sample the waveform at a GHz rate. Four channels of a chip are cascaded to obtain deeper sampling depth with 4096 capacitors. After a trigger is generated in a mezzanine on the board, the waveform stored in the capacitor array is subsequently digitized with a low speed (33 MHz) ADC and transferred via the FPGA-based Gigabit Ethernet to a data acquisition system. Both a low power consumption (2.64 W per channel) and high speed sampling with a bandwidth of >>300 MHz have been achieved. In addition, in order to increase the dynamic range of the readout we adopted a two gain system achieving from 0.2 up to 2000 photoelectrons in total. We finalized the board design for the first LST and proceeded to mass production. Performance of produced boards are being checked with a series of quality control (QC) tests. We report the readout board specifications and QC results.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

    PCFamily: a web server for searching homologous protein complexes

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    The proteins in a cell often assemble into complexes to carry out their functions and play an essential role of biological processes. The PCFamily server identifies template-based homologous protein complexes [called protein complex family (PCF)] and infers functional modules of the query proteins. This server first finds homologous structure complexes of the query using BLASTP to search the structural template database (11 263 complexes). PCFamily then searches the homologous complexes of the templates (query) from a complete genomic database (Integr8 with 6 352 363 protein sequences in 2274 species). According to these homologous complexes across multiple species, this sever infers binding models (e.g. hydrogen-bonds and conserved amino acids in the interfaces), functional modules, and the conserved interacting domains and Gene Ontology annotations of the PCF. Experimental results demonstrate that the PCFamily server can be useful for binding model visualizations and annotating the query proteins. We believe that the server is able to provide valuable insights for determining functional modules of biological networks across multiple species. The PCFamily sever is available at http://pcfamily.life.nctu.edu.tw

    Using magnetic resonance imaging to assess visual deficits : a review

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    PURPOSE: Over the last two decades, magnetic resonance imaging (MRI) has been widely used in neuroscience research to assess both structure and function in the brain in health and disease. With regard to vision research, prior to the advent of MRI, researchers relied on animal physiology and human post-mortem work to assess the impact of eye disease on visual cortex and connecting structures. Using MRI, researchers can non-invasively examine the effects of eye disease on the whole visual pathway, including the lateral geniculate nucleus, striate and extrastriate cortex. This review aims to summarise research using MRI to investigate structural, chemical and functional effects of eye diseases, including: macular degeneration, retinitis pigmentosa, glaucoma, albinism, and amblyopia. RECENT FINDINGS: Structural MRI has demonstrated significant abnormalities within both grey and white matter densities across both visual and non-visual areas. Functional MRI studies have also provided extensive evidence of functional changes throughout the whole of the visual pathway following visual loss, particularly in amblyopia. MR spectroscopy techniques have also revealed several abnormalities in metabolite concentrations in both glaucoma and age-related macular degeneration. GABA-edited MR spectroscopy on the other hand has identified possible evidence of plasticity within visual cortex. SUMMARY: Collectively, using MRI to investigate the effects on the visual pathway following disease and dysfunction has revealed a rich pattern of results allowing for better characterisation of disease. In the future MRI will likely play an important role in assessing the impact of eye disease on the visual pathway and how it progresses over time

    N-Palmitoyl Glycine, a Novel Endogenous Lipid That Acts As a Modulator of Calcium Influx and Nitric Oxide Production in Sensory Neurons

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    N-arachidonoyl glycine is an endogenous arachidonoyl amide that activates the orphan G protein-coupled receptor (GPCR) GPR18 in a pertussis toxin (PTX)-sensitive manner and produces antinociceptive and antiinflammatory effects. It is produced by direct conjugation of arachidonic acid to glycine and by oxidative metabolism of the endocannabinoid anandamide. Based on the presence of enzymes that conjugate fatty acids with glycine and the high abundance of palmitic acid in the brain, we hypothesized the endogenous formation of the saturated N-acyl amide N-palmitoyl glycine (PalGly). PalGly was partially purified from rat lipid extracts and identified using nano-high-performance liquid chromatography/hybrid quadrupole time-of-flight mass spectrometry. Here, we show that PalGly is produced after cellular stimulation and that it occurs in high levels in rat skin and spinal cord. PalGly was up-regulated in fatty acid amide hydrolase knockout mice, suggesting a pathway for enzymatic regulation. PalGly potently inhibited heat-evoked firing of nociceptive neurons in rat dorsal horn. In addition, PalGly induced transient calcium influx in native adult dorsal root ganglion (DRG) cells and a DRG-like cell line (F-11). The effect of PalGly on the latter cells was characterized by strict structural requirements, PTX sensitivity, and dependence on the presence of extracellular calcium. PalGly-induced calcium influx was blocked by the nonselective calcium channel blockers ruthenium red, 1-(beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl)-1H-imidazole (SK&F96365), and La3+. Furthermore, PalGly contributed to the production of NO through calcium-sensitive nitric-oxide synthase enzymes present in F-11 cells and was inhibited by the nitric-oxide synthase inhibitor 7-nitroindazole

    Decoding Plant–Environment Interactions That Influence Crop Agronomic Traits

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    To ensure food security in the face of increasing global demand due to population growth and progressive urbanization, it will be crucial to integrate emerging technologies in multiple disciplines to accelerate overall throughput of gene discovery and crop breeding. Plant agronomic traits often appear during the plants’ later growth stages due to the cumulative effects of their lifetime interactions with the environment. Therefore, decoding plant–environment interactions by elucidating plants’ temporal physiological responses to environmental changes throughout their lifespans will facilitate the identification of genetic and environmental factors, timing and pathways that influence complex end-point agronomic traits, such as yield. Here, we discuss the expected role of the life-course approach to monitoring plant and crop health status in improving crop productivity by enhancing the understanding of plant–environment interactions. We review recent advances in analytical technologies for monitoring health status in plants based on multi-omics analyses and strategies for integrating heterogeneous datasets from multiple omics areas to identify informative factors associated with traits of interest. In addition, we showcase emerging phenomics techniques that enable the noninvasive and continuous monitoring of plant growth by various means, including three-dimensional phenotyping, plant root phenotyping, implantable/injectable sensors and affordable phenotyping devices. Finally, we present an integrated review of analytical technologies and applications for monitoring plant growth, developed across disciplines, such as plant science, data science and sensors and Internet-of-things technologies, to improve plant productivity
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