91 research outputs found

    Protein binding regions of the mRNAs for the 55 kDa tumor necrosis factor receptor and the glucose transporter 1: sequence homology and competition for cellular proteins

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    AbstractGene expression is influenced by mechanisms regulating mRNA degradation. Knowledge on regulatory RNA elements involved and on proteins interacting with them is still limited. A 33 nucleotide (nt) region of the 55 kDa tumor necrosis factor receptor (TNFR-55) mRNA, previously reported by us to engage in such interaction with proteins from U-937 cells, exhibits homology to a 38 nt regulatory region of the glucose transporter GLUT-1 mRNA. Labeled RNA fragments comprising these two regions bind similar sets of proteins. Upon phorbol ester-induced differentiation into macrophage-like cells, protein binding to both fragments is changed similarly. Furthermore, both compete with each other for protein binding. This suggests that GLUT-1 and TNFR-55 RNA share a novel protein binding RNA motif involved in regulation of their half life

    A Tobacco Homolog of DCN1 is Involved in Cellular Reprogramming and in Developmental Transitions

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    Plant proteomes show remarkable plasticity in reaction to environmental challenges and during developmental transitions. Some of this adaptability comes from ubiquitin-mediated protein destruction regulated by cullin-RING E3 ubiquitin ligases (CRLs). CRLs are activated through modification of the cullin subunit with the ubiquitin-like protein RUB/NEDD8 by an E3 ligase called defective in cullin neddylation 1 (DCN1). Here we show that tobacco DCN1 binds ubiquitin and RUB/NEDD8, and associates with cullin. When knocked down by RNAi, tobacco pollen formation stopped and zygotic embryogenesis was blocked around the globular stage. Additionally, we found that RNAi of DCN1 inhibited the stress-triggered reprogramming of cultured microspores from their intrinsic gametophytic mode of development to an embryogenic state. This stress-induced developmental switch is a known feature in many important crops and leads ultimately to the formation of haploid embryos and plants. Compensating the RNAi effect by re-transformation with a promoter-silencing construct restored pollen development and zygotic embryogenesis, as well as the ability for stress-induced formation of embryogenic microspores. Overexpression of DCN1, however, accelerated pollen tube growth and increased the potential for microspore reprogramming. These results demonstrate that the biochemical function of DCN1 is conserved in plants and that its activity is specifically required for transitions during pollen development and embryogenesis, and for pollen tube tip growth

    Interleukin 1 activates jun N-terminal kinases JNK1 and JNK2 but not extracellular regulated MAP kinase (ERK) in human glomerular mesangial cells

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    AbstractInterleukin 1 (IL-1) potently activates human glomerular mesangial cells (HMC). In cytosolic extracts of IL-1-stimulated HMC or in anion exchange chromatography fractions we could not find any change in phosphorylation of myelin basic protein (MBP), a good substrate for extracellular regulated kinase (ERK). In contrast, IL-1 stimulated GST-jun kinase activity at least 10-fold. The jun kinase activity could be characterised as JNK1 and JNK2 at the protein and mRNA level. IL-1, TNF, UV light and osmotic stress, but not PMA, LPS, IL-3, IL-4, IL-6, IL-8, IL-10, IL-13, GM-CSF, PDGF, bFGF, TGF-β and interferon-γ were able to stimulate jun kinase activity in HMC, suggesting that jun kinase is selectively mediating signal transduction of the proinflammatory cytokines IL-1 and TNF as well as of cellular stress in HMC

    BOOST -- A Satellite Mission to Test Lorentz Invariance Using High-Performance Optical Frequency References

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    BOOST (BOOst Symmetry Test) is a proposed satellite mission to search for violations of Lorentz invariance by comparing two optical frequency references. One is based on a long-term stable optical resonator and the other on a hyperfine transition in molecular iodine. This mission will allow to determine several parameters of the standard model extension in the electron sector up to two orders of magnitude better than with the current best experiments. Here, we will give an overview of the mission, the science case and the payload.Comment: 11 pages, 2 figures, accepted for publication in Phys. Rev.

    Action plan for deriving dynamic RES-E policies

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    The core objective of this project is to facilitate a continuous and significant increase in the share of RESE with minimal costs to European citizen. To identify the most important strategies (e.g. Tradable Green Certificates, Feed-In Tariffs, Investment Subsidies, Emissions Trading, CO2-taxes) in a dynamic way the computer-based toolbox Green-X has been developed. Although within the scope of this project it has not been feasible to investigate all possible issues within this field, the cases analysed cover not only the needs and opportunities at the level of the national Member States, but also those at the level ofthe EU. However, the most important ones have been treated thoroughly. This report, which is the final outcome from the Green-X project (Contract No: ENG2-CT-2002- 00607), with funding from the European Commission, DG Research, provides recommendations on the way forward for the promotion of renewable energy for electricity generation in the EU. It is addressed primarily to energy policy maker, as well as to other people interested in renewable energy and energy policy

    Systematic reviews of complementary therapies - an annotated bibliography. Part 1: Acupuncture

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    Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with acupuncture. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of acupuncture; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pretested form and summarized descriptively. Results From a total of 48 potentially relevant reviews preselected in a screeening process 39 met the inclusion criteria. 22 were on various pain syndromes or rheumatic diseases. Other topics addressed by more than one review were addiction, nausea, asthma and tinnitus. Almost unanimously the reviews state that acupuncture trials include too few patients. Often included trials are heterogeneous regarding patients, interventions and outcome measures, are considered to have insufficient quality and contradictory results. Convincing evidence is available only for postoperative nausea, for which acupuncture appears to be of benefit, and smoking cessation, where acupuncture is no more effective than sham acupuncture. Conclusions A large number of systematic reviews on acupuncture exists. What is most obvious from these reviews is the need for (the funding of) well-designed, larger clinical trials

    HIV/AIDS, demography and development: individual choices versus public policies in SSA

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    Despite the increasing rate of diffusion of effective therapies, the battle against HIV/AIDS in Sub-Saharan Africa (SSA) is far from being over. Three main challenges are that the epidemics might paralyse or reverse the fertility transition, the expansion of the resources needed to finance the fight against HIV, and the emerging resistance to anti-retroviral treatments. This research proposes a UGT-like model showing the complexity of the interplay amongst the (macro)economy, the epidemics, their endogenous feedback on mortality and fertility and the central role of policy actions aimed to fight HIV. The disease-induced increase in adult mortality can hamper economic development by its upward pressure on the precautionary demand for children and downward pressure on education. This can dramatically reduce physical and human capital accumulation

    Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: A prospective study

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    <p>Abstract</p> <p>Background</p> <p>A precise modular topographic-morphological (MTM) classification for proximal humeral fractures may address current classification problems. The classification was developed to evaluate whether a very detailed classification exceeding the analysis of fractured parts may be a valuable tool.</p> <p>Methods</p> <p>Three observers classified plain radiographs of 22 fractures using both a simple version (fracture displacement, number of parts) and an extensive version (individual topographic fracture type and morphology) of the MTM classification. Kappa-statistics were used to determine reliability.</p> <p>Results</p> <p>An acceptable reliability was found for the simple version classifying fracture displacement and fractured main parts. Fair interobserver agreement was found for the extensive version with individual topographic fracture type and morphology.</p> <p>Conclusion</p> <p>Although the MTM-classification covers a wide spectrum of fracture types, our results indicate that the precise topographic and morphological description is not delivering reproducible results. Therefore, simplicity in fracture classification may be more useful than extensive approaches, which are not adequately reliable to address current classification problems.</p
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