112 research outputs found

    Features of proinflammatory cytokine production in patients with allergic rhinitis combined with <i>Helicobacter pylori</i>-associated pathologies

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    Investigating a role for pro- and anti-inflammatory cytokines in immune and inflammatory response represents one of the most pressing topics in current immunology. There have been accumulated a great body of data regarding the cytokine status during inflammatory processes in gastrointestinal tract. However, many issues remain poorly elucidated. Moreover, most of the studies were mainly aimed at examining biopsy material cytokines collected from various parts of the gastrointestinal tract or gastric juice. Here we present the data on investigating the features of cytokine production in patients with allergic rhinitis combined with H. pylori-associated diseases of the upper gastrointestinal tract. A total of 225 patients aged 18 to 40 years (mean age 29.5±6.74 years) were examined, among which 43 patients suffered from allergic rhinitis, 66 patients had inflammatory diseases of the upper gastrointestinal tract (chronic gastritis/gastroduodenitis), and 69 patients — allergic rhinitis with concomitant inflammatory diseases of the upper gastrointestinal tract. Patients were stratified to various study groups depending on diagnosed allergic rhinitis and H. pylori infection. Serum IL-6 and IL-8 level and complete blood cell count were measured. Statistical significance for difference in parameter frequencies between independent groups was assessed by using Fisher's exact test or χ2 criteria. It was shown that serum IL-6 level in H. pylori-negative patients was within the reference interval with single spikes, whereas its production was markedly increased in patients with H. pylori infection regardless of allergic pathology. Frequency of subjects with elevated serum IL-8 level was comparable between groups of patients with gastrointestinal diseases, but significantly higher than that one in the control group. An interdependence between serum IL-8 level and white blood cell count was found, which is of interest for predicting development of the inflammatory process. Thus, the serum IL-8 level during the upper gastrointestinal tract inflammatory diseases was increased regardless of verified of H. pylori infection and allergic rhinitis, whereas increased IL-6 serum level was observed solely in H. pylori-positive patients

    High Light Induced Disassembly of Photosystem II Supercomplexes in Arabidopsis Requires STN7-Dependent Phosphorylation of CP29

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    Photosynthetic oxidation of water and production of oxygen by photosystem II (PSII) in thylakoid membranes of plant chloroplasts is highly affected by changes in light intensities. To minimize damage imposed by excessive sunlight and sustain the photosynthetic activity PSII, organized in supercomplexes with its light harvesting antenna, undergoes conformational changes, disassembly and repair via not clearly understood mechanisms. We characterized the phosphoproteome of the thylakoid membranes from Arabidopsis thaliana wild type, stn7, stn8 and stn7stn8 mutant plants exposed to high light. The high light treatment of the wild type and stn8 caused specific increase in phosphorylation of Lhcb4.1 and Lhcb4.2 isoforms of the PSII linker protein CP29 at five different threonine residues. Phosphorylation of CP29 at four of these residues was not found in stn7 and stn7stn8 plants lacking the STN7 protein kinase. Blue native gel electrophoresis followed by immunological and mass spectrometric analyses of the membrane protein complexes revealed that the high light treatment of the wild type caused redistribution of CP29 from PSII supercomplexes to PSII dimers and monomers. A similar high-light-induced disassembly of the PSII supercomplexes occurred in stn8, but not in stn7 and stn7stn8. Transfer of the high-light-treated wild type plants to normal light relocated CP29 back to PSII supercomplexes. We postulate that disassembly of PSII supercomplexes in plants exposed to high light involves STN7-kinase-dependent phosphorylation of the linker protein CP29. Disruption of this adaptive mechanism can explain dramatically retarded growth of the stn7 and stn7stn8 mutants under fluctuating normal/high light conditions, as previously reported

    A Protein Phosphorylation Threshold for Functional Stacking of Plant Photosynthetic Membranes

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    Phosphorylation of photosystem II (PSII) proteins affects macroscopic structure of thylakoid photosynthetic membranes in chloroplasts of the model plant Arabidopsis. In this study, light-scattering spectroscopy revealed that stacking of thylakoids isolated from wild type Arabidopsis and the mutant lacking STN7 protein kinase was highly influenced by cation (Mg++) concentrations. The stacking of thylakoids from the stn8 and stn7stn8 mutants, deficient in STN8 kinase and consequently in light-dependent phosphorylation of PSII, was increased even in the absence of Mg++. Additional PSII protein phosphorylation in wild type plants exposed to high light enhanced Mg++-dependence of thylakoid stacking. Protein phosphorylation in the plant leaves was analyzed during day, night and prolonged darkness using three independent techniques: immunoblotting with anti-phosphothreonine antibodies; Diamond ProQ phosphoprotein staining; and quantitative mass spectrometry of peptides released from the thylakoid membranes by trypsin. All assays revealed dark/night-induced increase in phosphorylation of the 43 kDa chlorophyll-binding protein CP43, which compensated for decrease in phosphorylation of the other PSII proteins in wild type and stn7, but not in the stn8 and stn7stn8 mutants. Quantitative mass spectrometry determined that every PSII in wild type and stn7 contained on average 2.5±0.1 or 1.4±0.1 phosphoryl groups during day or night, correspondingly, while less than every second PSII had a phosphoryl group in stn8 and stn7stn8. It is postulated that functional cation-dependent stacking of plant thylakoid membranes requires at least one phosphoryl group per PSII, and increased phosphorylation of PSII in plants exposed to high light enhances stacking dynamics of the photosynthetic membranes

    Soluble CD44 Interacts with Intermediate Filament Protein Vimentin on Endothelial Cell Surface

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    CD44 is a cell surface glycoprotein that functions as hyaluronan receptor. Mouse and human serum contain substantial amounts of soluble CD44, generated either by shedding or alternative splicing. During inflammation and in cancer patients serum levels of soluble CD44 are significantly increased. Experimentally, soluble CD44 overexpression blocks cancer cell adhesion to HA. We have previously found that recombinant CD44 hyaluronan binding domain (CD44HABD) and its non-HA-binding mutant inhibited tumor xenograft growth, angiogenesis, and endothelial cell proliferation. These data suggested an additional target other than HA for CD44HABD. By using non-HA-binding CD44HABD Arg41Ala, Arg78Ser, and Tyr79Ser-triple mutant (CD443MUT) we have identified intermediate filament protein vimentin as a novel interaction partner of CD44. We found that vimentin is expressed on the cell surface of human umbilical vein endothelial cells (HUVEC). Endogenous CD44 and vimentin coprecipitate from HUVECs, and when overexpressed in vimentin-negative MCF-7 cells. By using deletion mutants, we found that CD44HABD and CD443MUT bind vimentin N-terminal head domain. CD443MUT binds vimentin in solution with a Kd in range of 12–37 nM, and immobilised vimentin with Kd of 74 nM. CD443MUT binds to HUVEC and recombinant vimentin displaces CD443MUT from its binding sites. CD44HABD and CD443MUT were internalized by wild-type endothelial cells, but not by lung endothelial cells isolated from vimentin knock-out mice. Together, these data suggest that vimentin provides a specific binding site for soluble CD44 on endothelial cells

    Catching-up in the global factory: analysis and policy implications

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    MNEs shape the location of activities in the world economy, linking diverse regions in what has been called the global factory. This study portrays the evolution of incomes and employment in the global factory using a quantitative input–output approach. We find emerging economies forging ahead relative to advanced economies in income derived from fabrication activities, handling the physical transformation process of goods. In contrast, convergence in income derived from knowledge-intensive activities carried out in pre- and post-fabrication stages is much slower. We discuss possible barriers to catching-up and policy implications for emerging economies in developing innovation capabilities, stressing the pivotal role of MNEs

    FDI and regional development policy

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    The transformations in the worldwide division of labour brought about by globalisation and technological change have shown an unintended negative effect, particularly evident in advanced economic systems: uneven spatial distribution of wealth and rising within-country inequality. Although the latter has featured prominently in recent academic and policy debates, in this paper we argue that the relevance of connectivity (here proxied by foreign capital investments, FDI) for regional economic development is still underestimated and suffers from a nation-biased perspective. As a consequence, the relationship between the spatial inequality spurred by the global division of labour and the changes in the structural advantages of regions remains to be fully understood in its implications for economic growth, territorial resilience and industrial policy. Furthermore, even though connectivity entails bi-directional links – i.e. with regions being simultaneously receivers and senders – attractiveness to foreign capital has long been at the centre of policy attention whilst internationalisation through investment abroad has been disregarded, and sometimes purposely ignored, in regional development policy agendas. We use three broad-brushed European case-studies to discuss some guiding principles for a place-sensitive regional policy eager to integrate the connectivity dimension in pursuing local economic development and territorial equity

    Changing perspectives on the internationalization of R&D and innovation by multinational enterprises: a review of the literature

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    Internationalization of R&D and innovation by Multinational Enterprises (MNEs) has undergone a gradual and comprehensive change in perspective over the past 50 years. From sporadic works in the late 1950s and in the 1960s, it became a systematically analysed topic in the 1970s, starting with pioneering reports and “foundation texts”. Our review unfolds the theoretical and empirical evolution of the literature from dyadic interpretations of centralization versus decentralization of R&D by MNEs to more comprehensive frameworks, wherein established MNEs from Advanced Economies still play a pivotal role, but new players and places also emerge in the global generation and diffusion of knowledge. Hence views of R&D internationalization increasingly rely on concepts, ideas and methods from IB and other related disciplines such as industrial organization, international economics and economic geography. Two main findings are highlighted. First, scholarly research pays an increasing attention to the network-like characteristics of international R&D activities. Second, different streams of literature have emphasized the role of location- specific factors in R&D internationalization. The increasing emphasis on these aspects has created new research opportunities in some key areas, including inter alia: cross-border knowledge sourcing strategies, changes in the geography of R&D and innovation, and the international fragmentation of production and R&D activities
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