1,067 research outputs found

    Redistribution of DNA topoisomerase II beta after in vitro stabilization of human erythroleukemic nuclei by heat or Cu++ revealed by confocal microscopy.

    Get PDF
    Using confocal laser scanning microscope and a monoclonal antibody we have examined by means of indirect immunofluorescence techniques the distribution of DNA topoisomerase II beta (the 180-kDa nucleolar isoform of topoisomerase II) following stabilization of isolated nuclei by exposure to moderate heat (37 degrees or 42 degrees C) or Cu++. In intact cells the antibody specifically decorated the nucleoli. The same pattern was maintained if nuclei were incubated at 0 degree C in a buffer containing spermine/spermidine/KCl or stabilized by means of 0.5 mM Cu++ for 10 minutes at 0 degree C in the same buffer. On the contrary, if stabilization was performed by incubating the nuclei either at 37 degrees or 42 degrees C, the immunoreactivity dispersed all over the nucleus, forming numerous speckles. This phenomenon was not detected if, in addition to spermine/spermidine/KCl, the incubation buffer also contained 5 mM Mg++ and the temperature was 37 degrees C. If the stabilization was performed at 42 degrees C, Mg++ failed to maintain the original distribution of DNA topoisomerase II beta, as seen in intact cells. The analysis on 2-D optical section showed the alteration of the nucleolar profile, particularly at 37 degrees C, even when the samples were treated with Mg++. The 3-D reconstruction figured out the irregularity of the surface at 37 degrees C and the variations of the volume occupied by the fluorescent figures. These were in close proximity to each other both in intact cells and in 0 degree C incubated nuclei; they showed a certain degree of shrinkage in 0 degree C plus Cu++ exposed samples (-20\% of the volume), and, on the contrary, the labeled structures were scattered in a volume increased two- or threefold when exposed to 37 degrees or 42 degrees C, respectively. The addition of Mg++ restored the original spatial relationship and volume at 37 degrees C, but not at 42 degrees C, where the volumetric analysis showed an increase of about 50\%. Our results demonstrate that heat stabilization of isolated nuclei in a buffer without Mg++ (i.e., a technique often employed to prepare the nuclear matrix or scaffold) cannot be considered an optimal procedure to maintain the original distribution of protein within the nucleus

    Coverage and Deployment Analysis of Narrowband Internet of Things in the Wild

    Full text link
    Narrowband Internet of Things (NB-IoT) is gaining momentum as a promising technology for massive Machine Type Communication (mMTC). Given that its deployment is rapidly progressing worldwide, measurement campaigns and performance analyses are needed to better understand the system and move toward its enhancement. With this aim, this paper presents a large scale measurement campaign and empirical analysis of NB-IoT on operational networks, and discloses valuable insights in terms of deployment strategies and radio coverage performance. The reported results also serve as examples showing the potential usage of the collected dataset, which we make open-source along with a lightweight data visualization platform.Comment: Accepted for publication in IEEE Communications Magazine (Internet of Things and Sensor Networks Series

    Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

    Get PDF
    Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity

    X-ray spectroscopy of the z=6.4 quasar J1148+5251

    Full text link
    We present the 78-ks Chandra observations of the z=6.4z=6.4 quasar SDSS J1148+5251. The source is clearly detected in the energy range 0.3-7 keV with 42 counts (with a significance 9σ\gtrsim9\sigma). The X-ray spectrum is best-fitted by a power-law with photon index Γ=1.9\Gamma=1.9 absorbed by a gas column density of NH=2.01.5+2.0×1023cm2\rm N_{\rm H}=2.0^{+2.0}_{-1.5}\times10^{23}\,\rm cm^{-2}. We measure an intrinsic luminosity at 2-10 keV and 10-40 keV equal to 1.5×1045 erg s1\sim 1.5\times 10^{45}~\rm erg~s^{-1}, comparable with luminous local and intermediate-redshift quasar properties. Moreover, the X-ray to optical power-law slope value (αOX=1.76±0.14\alpha_{\rm OX}=-1.76\pm 0.14) of J1148 is consistent with the one found in quasars with similar rest-frame 2500 \AA ~luminosity (L25001032 erg s1L_{\rm 2500}\sim 10^{32}~\rm erg~s^{-1}\AA1^{-1}). Then we use Chandra data to test a physically motivated model that computes the intrinsic X-ray flux emitted by a quasar starting from the properties of the powering black hole and assuming that X-ray emission is attenuated by intervening, metal-rich (ZZZ\geq \rm Z_{\odot}) molecular clouds distributed on \simkpc scales in the host galaxy. Our analysis favors a black hole mass MBH3×109MM_{\rm BH} \sim 3\times 10^9 \rm M_\odot and a molecular hydrogen mass MH22×1010MM_{\rm H_2}\sim 2\times 10^{10} \rm M_\odot, in good agreement with estimates obtained from previous studies. We finally discuss strengths and limits of our analysis.Comment: 9 pages, 3 figures, 1 table, MNRAS in pres

    J.D. Thompson’s Organizations in Action 50th anniversary: a reflection

    Get PDF
    At the 50th anniversary of James D. Thompson’s fundamental book, Organizations in Action, TAO Digital Library proposes a reflection on this great master’s legacy and the evolution of organizational studies. Twelve researchers, from different disciplinary fields, analyze both the texts utilized for teaching and the contribution of several important journals, particularly in recent decades. The outcome is an overall picture that may stimulate different, divergent evaluations and, even more importantly, desirable, deeper reflections

    IL-8 and thrombospondin-1 as prognostic markers in patients with metastatic colorectal cancer receiving bevacizumab

    Get PDF
    Purpose: Bevacizumab (B) plus chemotherapy (CT) is a common choice for first-line treatment of metastatic colorectal cancer. Molecular predictors of B efficacy have still not been identified. We analyzed the role of 22 angiogenesis-associated proteins in patient outcome. Patients and methods: Serum samples collected at baseline and at the first clinical evaluation were available for 58 patients enrolled in the randomized multicenter ITACa trial and who received CT+ B. Serum protein levels were determined using multiplex ELISA. Results: Patients with baseline 65145 pg/mL IL-8 showed shorter median progression-free survival and overall survival (OS) than those with lower levels (6.5 vs 6. 12.6 months; HR 7.39, P<0.0001 and 8.7 vs 28.8 months, HR 7.68, P<0.001, respectively). Moreover, patients with baseline thrombospondin-1 levels 6512,000 ng/mL had a better median OS than those with lower levels (34.5 vs 13.1 months, HR 0.43, P=0.007). Patients with a 6520% reduction in IL-8 levels from baseline to first clinical evaluation showed a better progression-free survival and OS than the others (HR 0.41, P=0.005 and HR 0.43, P=0.007, respectively). Conclusion: Baseline IL-8 and thrombospondin-1 levels and reduced IL-8 during B treatment could represent potential prognostic markers in metastatic colorectal cancer

    Synergistic effects of selective inhibitors targeting the PI3K/AKT/mTOR pathway and NUP214-ABL1 fusion protein in human acute lymphoblastic leukemia

    Get PDF
    Acute lymphoblastic leukemia (ALL) is a neoplasm of precursor cells committed to the B-cell and T-cell lineages involving bone marrow and blood, with a rapid onset and frequent chemotherapy resistance and refractory relapses (1). Philadelphia chromosome-positive (Ph+) ALL accounts for 25–30% of adult ALL and its incidence increases with age in adults >40 years old. Irrespective of age, the ABL1 fusion genes, among which BCR-ABL1 is the most commonly found, are markers of very poor prognosis. Amplification of the NUP214-ABL1 oncogene can be detected only in patients with T-ALL (2). The PI3K/Akt/mTOR signaling pathway is activated in many solid cancers and in leukemias and plays a crucial role in tumorigenesis. Furthermore, the presence of RTKs (Receptor Tyrosine Kinases) by ABL1 fusion proteins may result in activation of the PI3K/Akt/mTOR axis. T cell malignancies bearing the ABL1 fusion genes are sensitive to many cytotoxic agents, but up to date complete remissions have not been found. In this work we analyzed the effects of three BCR-ABL1 tyrosine kinase inhibitors (TKIs), alone and in combination with a panel of selective PI3K/Akt/mTOR inhibitors, on two NUP214-ABL1 positive T-ALL cell lines, ALL-SIL and PEER that also displayed Akt hyperactivation. Cells were sensitive to anti BCR-ABL1 TKIs Imatinib, Nilotinib and GZD824, that specifically targeted the ABL1 fusion protein, but not the PI3K/Akt/mTOR axis as deducted by a readout of drug efficacy, four drugs against the PI3K/Akt/mTOR cascade, GSK690693, NVP-BGT226 (BGT226), ZSTK474 and Torin-2, showed a relevant cytotoxic efficacy on T-leukemic cells, without affecting the NUP214-ABL1 kinase and related pathway. Dephosphorylation of pAkt and pS6 showed the cytotoxicity of the compounds. Either single or combined administration of drugs against the different targets displayed inhibition of cellular viability which was associated with a concentration-dependent induction of apoptosis, cell cycle arrest in G0/G1 phase and autophagy, having the combined treatments a significant synergistic cytotoxic effect. Co-targeting NUP214-ABL1 fusion gene and PI3K/Akt/mTOR signaling pathway could represent a new and effective pharmacological strategy to improve the outcome in NUP214-ABL1 positive T-ALL

    In-depth study of the hypercompact H II region G24.78+0.08 A1

    Get PDF
    Context. The earliest phases of the evolution of a massive star are closely related to the developement of an H II region. Hypercompact H II regions are the most interesting in this respect because they are very young, and hence best suited to study the beginning of the expansion of the ionised gas inside the parental core. Aims: We have analysed the geometrical and physical structure of the hypercompact H II region G24.78+0.08 A1, making use of new continuum and hydrogen recombination line data (H41α, H63α, H66α, H68α) and data from the literature (H30α, H35α). Methods: We fit the continuum spectrum with a homogenous, isothermal shell of ionised gas at 104 K and derive the size of the H II region and the Lyman continuum luminosity of the ionising star. We also fit the recombination line spectra emitted from the same shell with a model taking into account expansion at constant speed. Results: The best fits to the continuum and line spectra allow the derivation of the Lyman continuum luminosity of the ionising star, H II region size, geometrical thickness of the shell, and expansion velocity. Comparison between the 5 cm and 7 mm brightness temperature distributions demonstrates that a thin layer of ionised gas of a few 1000 K at the surface of the H II region is necessary to reproduce the morphology of the continuum emission at both wavelengths. Conclusions: We confirm that the G24 A1 hypercompact H II region consists of a thin shell ionised by an O9.5 star. The shell is expanding at a speed comparable to the sound speed in the ionised gas. The radius of the H II region exceeds the critical value needed to trap the ionised gas by the gravitational field of the star, consistent with the observed expansion

    Roles of GSK-3 and microRNAs on epithelial mesenchymal transition and cancer stem cells

    Get PDF
    Various signaling pathways exert critical roles in the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs). The Wnt/beta-catenin, PI3K/PTEN/ Akt/mTORC, Ras/Raf/MEK/ERK, hedgehog (Hh), Notch and TP53 pathways elicit essential regulatory influences on cancer initiation, EMT and progression. A common kinase involved in all these pathways is moon-lighting kinase glycogen synthase kinase-3 (GSK-3). These pathways are also regulated by micro-RNAs (miRs). TP53 and components of these pathways can regulate the expression of miRs. Targeting members of these pathways may improve cancer therapy in those malignancies that display their abnormal regulation. This review will discuss the interactions of the multi-functional GSK-3 enzyme in the Wnt/beta-catenin, PI3K/PTEN/Akt/mTORC, Ras/Raf/MEK/ERK, Hh, Notch and TP53 pathways. The regulation of these pathways by miRs and their effects on CSC generation, EMT, invasion and metastasis will be discussed
    corecore