1,837 research outputs found

    Carrageenan-induced acute inflammation in the mouse air pouch synovial model. Role of tumour necrosis factor

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    We used the mouse air pouch model of inflammation to study the interaction between cytokines, prostaglandin E2 (PGE2) and cell migration during the various phases of acute local inflammation induced by carrageenan. In serum, the levels of interleukin 1 (IL-1), interleukin 6 (IL-6), tumour necrosis factor (TNF), serum amiloid-A (SAA) and Fe++ were never different from controls, indicating that no systemic inflammatory changes were induced. Locally the exudate volume and the number of leukocytes recruited into the pouch increased progressively until 7 days after carrageenan. The same was true for PGE2 production. We could not measure IL-1 but the production of IL-6 and TNF reached a maximum after 5-24 h then quickly decreased. Anti-TNF antibodies inhibited cell migration by 50% 24 h after treatment. Pretreatment with interleukin 10 (IL-10) inhibited TNF production almost completely and cell migration by 60%. Carrageenan-induced inflammation was modulated by anti-inflammatory drugs. Pretreatment with dexamethasone (DEX) or indomethacin (INDO) inhibited cell migration and reduced the concentration of TNF in the exudate. Production of PGE2 or vascular permeability did not correlate with the number of cells in the pouch. Local TNF seems to play an important role in this model, particularly for leukocyte migration in the first phase of the inflammatory process. In conclusion, the air pouch seems to be a good model for studying the regulation of the early events of local inflammation, particularly the role of cytokines and cell migration

    IBIS: The Imager on-board INTEGRAL

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    The IBIS telescope is the high angular resolution gamma-ray imager on-board the INTEGRAL Observatory, successfully launched from Baikonur (Kazakhstan) the 17th of October 2002. This medium size ESA project, planned for a 2 year mission with possible extension to 5, is devoted to the observation of the gamma-ray sky in the energy range from 3 keV to 10 MeV (Winkler 2001). The IBIS imaging system is based on two independent solid state detector arrays optimised for low ( 15-1000 keV) and high ( 0.175-10.0 MeV) energies surrounded by an active VETO System. This high efficiency shield is essential to minimise the background induced by high energy particles in the highly excentric out of van Allen belt orbit. A Tungsten Coded Aperture Mask, 16 mm thick and ~1 squared meter in dimension is the imaging device. The IBIS telescope will serve the scientific community at large providing a unique combination of unprecedented high energy wide field imaging capability coupled with broad band spectroscopy and high resolution timing over the energy range from X to gamma rays. To date the IBIS telescope is working nominally in orbit since more than 9 month.Reglero Velasco, Victor, [email protected]

    The Sea Urchin sns5 Chromatin Insulator Improves the Likelihood of Lentiviral Vectors in Erythroid Milieu By Organizing an Independent Chromatin Domain at the Integration Site

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    Retroviral vectors are currently the most suitable vehicles for therapeutic gene transfer in hematopoietic stem cells. However, these vectors are known to integrate rather randomly throughout the genome, suffering the so called chromosomal position effects (PE). Such a critical occurrence most probably depends upon the ability of heterochromatin to spread in the inserted vector sequences. Moreover, the use of transgenes imply genotoxicity effects, since the cis-regulatory sequences harbored by the vector can disturb the proper transcription of the resident genes neighboring the integration site, potentially leading to malignant transformation. Due to their enhancer blocker activity, the incorporation of chromatin insulators in flanking position to the transferred unit can reduce the mentioned dangerous effects. Moreover, by acting as barriers to the spread of heterochromatin, chromatin insulators can also mitigate vector silencing. We have previously shown that the sea urchin sns5 chromatin insulator activity is conserved in mouse and human erythroid milieu: it blocks the βglobin-LCR-HS2 enhancer/globin promoter interaction when placed between them. In addition, when placed in flanking location of a γ-retrovirus vector, sns5 impedes PE variegation and improves vector-specific expression following integration in the erythroid genome. Importantly, by binding both erythroid-specific and ubiquitous factors, sns5 favors the accumulation inside the provirus locus of epigenetic marks commonly associated to an euchromatic state (Acuto S. et al., BCMD 2005; D'Apolito D. et al., 2009; Di Caro D. et al., J Mol Biol 2004; Cavalieri V. et al., NAR 2009). In this study we extend these findings, demonstrating that sns5 works as chromatin insulator also when placed in flanking position of a GFP transgene contained in a lentivirus vector (LV-GFP). A large panel of mouse erythroleukemic clones (MELC) was generated after transduction with uninsulated and sns5 -insulated LV-GFP. Individual clones were screened for single vector integrants (by Q-PCR), and for GFP-expression (by cytofluorimetry). Our results shown that the inclusion of the sns5 element in a forward orientation increased the fraction of vector expressing cells (89% for the insulated vector vs 42% for the uninsulated ones). The clonal variegation of expression, assessed as frequency of clones that showed a percentage of GFP-negative cells in the progeny, decreased in clones transduced with the insulated vectors (7.4% vs 13,9%). It has been suggested that chromatin insulators could shape the architecture of topologically independent chromosome domains. High resolution mapping of chromosomal domains in drosophila and higher eukaryotes highlighted that chromatin insulators play a critical role in shaping the architectural genome organization both in a local chromosome environment and in long range chromosomal interaction. Intriguingly, by using the Chromosome Conformation Capture (3C) technology, we demonstrated that the sns5 -flanked LV-GFP integrated at a single copy in the erythroid cell genome is organized into an independent chromatin loop at the integration site. Worth to mention, no looping was detected in the absence of sns5, indicating that the two flanking copies of sns5 are specifically involved in the reorganization of the chromatin structure at the provirus locus. In conclusion our results not only confirm the conserved and striking boundary function of sns5, but also provide a new clue concerning the molecular mechanism that allows this function to occur. On these basis, our findings reassure the use of sns5 to improve both efficacy and safety of lentiviral vectors for gene therapy

    Expected performance of the ASTRI-SST-2M telescope prototype

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    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica) strictly linked to the development of the Cherenkov Telescope Array, CTA. Primary goal of the ASTRI program is the design and production of an end-to-end prototype of a Small Size Telescope for the CTA sub-array devoted to the highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be tested on field in Italy during 2014. This telescope will be the first Cherenkov telescope adopting the double reflection layout in a Schwarzschild-Couder configuration with a tessellated primary mirror and a monolithic secondary mirror. The collected light will be focused on a compact and light-weight camera based on silicon photo-multipliers covering a 9.6 deg full field of view. Detailed Monte Carlo simulations have been performed to estimate the performance of the planned telescope. The results regarding its energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223

    A follow-up study for left ventricular mass on chromosome 12p11 identifies potential candidate genes

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    <p>Abstract</p> <p>Background</p> <p>Left ventricular mass (LVM) is an important risk factor for cardiovascular disease. Previously we found evidence for linkage to chromosome 12p11 in Dominican families, with a significant increase in a subset of families with high average waist circumference (WC). In the present study, we use association analysis to further study the genetic effect on LVM.</p> <p>Methods</p> <p>Association analysis with LVM was done in the one LOD critical region of the linkage peak in an independent sample of 897 Caribbean Hispanics. Genotype data were available on 7085 SNPs from 23 to 53 MB on chromosome 12p11. Adjustment was made for vascular risk factors and population substructure using an additive genetic model. Subset analysis by WC was performed to test for a difference in genetic effects between the high and low WC subsets.</p> <p>Results</p> <p>In the overall analysis, the most significant association was found to rs10743465, downstream of the <it>SOX5 </it>gene (p = 1.27E-05). Also, 19 additional SNPs had nominal p < 0.001. In the subset analysis, the most significant difference in genetic effect between those with high and low WC occurred with rs1157480 (p = 1.37E-04 for the difference in β coefficients), located upstream of <it>TMTC1</it>. Twelve additional SNPs in or near 6 genes had p < 0.001.</p> <p>Conclusions</p> <p>The current study supports previously identified evidence by linkage for a genetic effect on LVM on chromosome 12p11 using association analysis in population-based Caribbean Hispanic cohort. <it>SOX5 </it>may play an important role in the regulation of LVM. An interaction of <it>TMTC1 </it>with abdominal obesity may contribute to phenotypic variation of LVM.</p
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