69 research outputs found

    Identification of a functional 3′,5′-cyclic adenosine monophosphate response element within the second promoter of the mouse somatostatin receptor type 2 gene

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    AbstractImportant physiological actions of somatostatin are mediated by the somatostatin receptor type 2. Its transcription is regulated by three tissue specific, alternative promoters. It is known that the mRNA of the somatostatin receptor type 2 gene is induced by cAMP, but little is known about the mechanisms underlying this regulation. We have identified and characterized a cAMP responsive element located at nucleotide −162 on the second promoter of the gene consisting of the classical palindromic octameric sequence 5′-TGACGTCA-3′. Using transient expression of reporter gene deletion constructs in NG108-15 cells the necessity of the intact element for forskolin-induced reporter gene activity was demonstrated. The first and the third promoter are not responsive to forskolin, nor did any promoter respond to the phorbol ester PMA. Electrophoretic mobility shift assays in combination with competition experiments suggest the interaction of the promoter element with the cAMP responsive element binding protein

    The use of moderate hypothermia during cardiac surgery is associated with repression of tumour necrosis factor-α via inhibition of activating protein-1: an experimental study

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    INTRODUCTION: The use of moderate hypothermia during experimental cardiac surgery is associated with decreased expression of tumour necrosis factor (TNF)-α in myocardium and with myocardial protection. In order to identify the cellular mechanisms that lead to that repression, we investigated the effect of hypothermia during cardiac surgery on both main signalling pathways involved in systemic inflammation, namely the nuclear factor-κB (NF-κB) and activating protein-1 pathways. METHOD: Twelve female pigs were randomly subjected to standardized cardiopulmonary bypass with moderate hypothermia or normothermia (temperature 28°C and 37°C, respectively; six pigs in each group). Myocardial probes were sampled from the right ventricle before, during and 6 hours after bypass. We detected mRNA encoding TNF-α by competitive RT-PCR and measured protein levels of TNF-α, inducible nitric oxide synthase and cyclo-oxygenase-2 by Western blotting. Finally, we assessed the activation of NF-κB and activating protein-1, as well as phosphorylation of p38 mitogen-activated protein kinase by electrophoretic mobility shift assay with super shift and/or Western blot. RESULTS: During and after cardiac surgery, animals subjected to hypothermia exhibited lower expression of TNF-α and cyclo-oxygenase-2 but not of inducible nitric oxide synthase. This was associated with lower activation of p38 mitogen-activated protein kinase and of its downstream effector activating protein-1 in hypothermic animals. In contrast, NF-κB activity was no different between groups. CONCLUSION: These findings indicate that the repression of TNF-α associated with moderate hypothermia during cardiac surgery is associated with inhibition of the mitogen-activated protein kinase p38/activating protein-1 pathway and not with inhibition of NF-κB. The use of moderate hypothermia during cardiac surgery may mitigate the perioperative systemic inflammatory response and its complications

    Neural differentiation potential of human bone marrow-derived mesenchymal stromal cells: misleading marker gene expression

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    Background: In contrast to pluripotent embryonic stem cells, adult stem cells have been considered to be multipotent, being somewhat more restricted in their differentiation capacity and only giving rise to cell types related to their tissue of origin. Several studies, however, have reported that bone marrow-derived mesenchymal stromal cells (MSCs) are capable of transdifferentiating to neural cell types, effectively crossing normal lineage restriction boundaries. Such reports have been based on the detection of neural-related proteins by the differentiated MSCs. In order to assess the potential of human adult MSCs to undergo true differentiation to a neural lineage and to determine the degree of homogeneity between donor samples, we have used RT-PCR and immunocytochemistry to investigate the basal expression of a range of neural related mRNAs and proteins in populations of non-differentiated MSCs obtained from 4 donors. Results: The expression analysis revealed that several of the commonly used marker genes from other studies like nestin, Enolase2 and microtubule associated protein 1b (MAP1b) are already expressed by undifferentiated human MSCs. Furthermore, mRNA for some of the neural-related transcription factors, e.g. Engrailed-1 and Nurr1 were also strongly expressed. However, several other neural-related mRNAs (e.g. DRD2, enolase2, NFL and MBP) could be identified, but not in all donor samples. Similarly, synaptic vesicle-related mRNA, STX1A could only be detected in 2 of the 4 undifferentiated donor hMSC samples. More significantly, each donor sample revealed a unique expression pattern, demonstrating a significant variation of marker expression. Conclusion: The present study highlights the existence of an inter-donor variability of expression of neuralrelated markers in human MSC samples that has not previously been described. This donor-related heterogeneity might influence the reproducibility of transdifferentiation protocols as well as contributing to the ongoing controversy about differentiation capacities of MSCs. Therefore, further studies need to consider the differences between donor samples prior to any treatment as well as the possibility of harvesting donor cells that may be inappropriate for transplantation strategies

    Textile Design of an Intervertebral Disc Replacement Device from Silk Yarn

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    Low back pain is often due to degeneration of the intervertebral discs (IVD). It is one of the most common age- and work-related problems in today’s society. Current treatments are not able to efficiently restore the full function of the IVD. Therefore, the aim of the present work was to reconstruct the two parts of the intervertebral disc—the annulus fibrosus (AF) and the nucleus pulposus (NP)—in such a way that the natural structural features were mimicked by a textile design. Silk was selected as the biomaterial for realization of a textile IVD because of its cytocompatibility, biodegradability, high strength, stiffness, and toughness, both in tension and compression. Therefore, an embroidered structure made of silk yarn was developed that reproduces the alternating fiber structure of +30° and −30° fiber orientation found in the AF and mimics its lamellar structure. The developed embroidered ribbons showed a tensile strength that corresponded to that of the natural AF. Fiber additive manufacturing with 1 mm silk staple fibers was used to replicate the fiber network of the NP and generate an open porous textile 3D structure that may serve as a reinforcement structure for the gel-like NP

    Применение детандер-генератора для повышения ресурсоэффективности газораспределительной станции магистрального газопровода

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    Объектом исследования является: Газораспределительная станция "Урожай-20" магистрального газопровода "П-К" в Томской области. Цель работы: Выбор наиболее оптимального детандер–генераторного агрегата для использования потенциала природного газа при редуцировании на газораспределительной станции. В процессе исследования были проведены: аналитический обзор детандер–генераторных агрегатов применимых для газораспределительных станций различной производительности, изучение характеристик и специфики эксплуатации газораспределительной станции; выбор оптимального детандер–генераторного агрегата для использования его на ГРС-Ч "Урожай-20; проведение расчетов мощности и рентабельности применения детандер–генераторного агрегата.Object of the study: gas distribution station "Urozhay-20" of the main gas pipeline "P-K" in the of the Tomsk region. Purpose – Selection of the most optimal expander-generator set for using natural gas capabilities while reducing at a gas distribution station. The study included: analytical review of expander-generator sets applicable for gas distribution stations of various capacities, study of characteristics and specific features of operation of the gas distribution station, selection of the optimal expander-generator set for its use on GDS "Urozhai-20, carrying out of calculations of capacity and profitability of application of the expander-generator set, adoption of the most acceptable schemes for the introduction of an expander-generator set at AGRS "Urozhay-20"
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