21 research outputs found

    A laboratory-based scoring system predicts early treatment in Rai 0 chronic lymphocytic leukemia

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    We present a laboratory-based prognostic calculator (designated CRO score) to risk stratify treatment-free survival in early stage (Rai 0) chronic lymphocytic leukemia developed using a training-validation model in a series of 1,879 cases from Italy, the United Kingdom and the United States. By means of regression analysis, we identified five prognostic variables with weighting as follows: deletion of the short arm of chromosome 17 and unmutated immunoglobulin heavy chain gene status, 2 points; deletion of the long arm of chromosome 11, trisomy of chromosome 12, and white blood cell count>32.0x103/microliter, 1 point. Low, intermediate and high-risk categories were established by recursive partitioning in a training cohort of 478 cases, and then validated in four independent cohorts of 144/395/540/322 cases, as well as in the composite validation cohort. Concordance indices were 0.75 in the training cohort and ranged from 0.63 to 0.74 in the four validation cohorts (0.69 in the composite validation cohort). These findings advocate potential application of our novel prognostic calculator to better stratify early-stage chronic lymphocytic leukemia, and aid case selection in risk-adapted treatment for early disease. Furthermore, they support immunocytogenetic analysis in Rai 0 chronic lymphocytic leukemia being performed at the time of diagnosis to aid prognosis and treatment, particularly in today's chemo-free era

    Spectral analysis of spatially resolved 3C295 (sub-arcsecond resolution) with the International LOFAR Telescope

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    3C295 is a bright, compact steep spectrum source with a well-studied integrated radio spectral energy distribution (SED) from 132 MHz to 15 GHz. However, spatially resolved spectral studies have been limited due to a lack of high resolution images at low radio frequencies. These frequencies are crucial for measuring absorption processes, and anchoring the overall spectral modelling of the radio SED. In this paper, we use International LOw-Frequency ARray (LOFAR) Telescope (ILT) observations of 3C295 to study its spatially resolved spectral properties with sub-arcsecond resolution at 132 MHz. Combining our new 132 MHz observation with archival data at 1.6 GHz, 4.8 GHz, and 15 GHz, we are able to carry out a resolved radio spectral analysis. The spectral properties of the hotspots provides evidence for low frequency flattening. In contrast, the spectral shape across the lobes is consistent with a Jaffe-Perola spectral ageing model. Using the integrated spectral information for each component, we then fitted low-frequency absorption models to the hotspots, finding that both free-free absorption and synchrotron self-absorption models provide a better fit to the data than a standard power law. Although we can say there is low-frequency absorption present in the hotspots of 3C295, future observations with the Low Band Antenna of the ILT at 55 MHz may allow us to distinguish the type of absorption

    The LOFAR window on star-forming galaxies and AGNs – curved radio SEDs and IR–radio correlation at 0

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    We present a study of the low-frequency radio properties of star-forming (SF) galaxies and active galactic nuclei (AGNs) up to redshift z = 2.5. The new spectral window probed by the Low Frequency Array (LOFAR) allows us to reconstruct the radio continuum emission from 150 MHz to 1.4 GHz to an unprecedented depth for a radio-selected sample of 1542 galaxies in ∼ 7 deg2 of the LOFAR Boötes field. Using the extensive multiwavelength data set available in Boötes and detailed modelling of the far-infrared to ultraviolet spectral energy distribution (SED), we are able to separate the star formation (N = 758) and the AGN (N = 784) dominated populations. We study the shape of the radio SEDs and their evolution across cosmic time and find significant differences in the spectral curvature between the SF galaxy and AGN populations. While the radio spectra of SF galaxies exhibit a weak but statistically significant flattening, AGN SEDs show a clear trend to become steeper towards lower frequencies. No evolution of the spectral curvature as a function of redshift is found for SF galaxies or AGNs. We investigate the redshift evolution of the infrared–radio correlation for SF galaxies and find that the ratio of total infrared to 1.4-GHz radio luminosities decreases with increasing redshift: q1.4 GHz = (2.45 ± 0.04) (1 + z)−0.15 ± 0.03 . Similarly, q150 MHz shows a redshift evolution following q150 GHz = (1.72 ± 0.04) (1 + z)−0.22 ± 0.05 . Calibration of the 150 MHz radio luminosity as a star formation rate tracer suggests that a single power-law extrapolation from q1.4 GHz is not an accurate approximation at all redshifts

    Thymosin beta-4 is essential for coronary vessel development and promotes neovascularization via adult epicardium.

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    Ischemic heart disease leading to myocardial infarction causes irreversible cell loss and scarring and is a major cause of morbidity and mortality in humans. Significant effort in the field of cardiovascular medicine has been invested in the search for adult cardiac progenitor cells that may replace damaged muscle cells and/or contribute to new vessel formation (neovascularization) and in the identification of key factors, which may induce such progenitor cells to contribute to myocardial repair and collateral vessel growth. We recently demonstrated that the actin monomer-binding protein, thymosin beta-4 (Tbeta-4), when secreted from the myocardium provides a paracrine stimulus to the cells of the epicardium-derived cells (EPDCs) to promote their inward migration and differentiation into endothelial and smooth muscle cells to form the coronary vasculature. Translating this essential role for Tbeta-4 in coronary vessel development to the adult, we found that treatment of cultured adult explants with Tbeta-4 stimulated extensive outgrowth of epicardin-positive epicardial cells, which, as they migrated away from the explant, differentiated into procollagen type I, SMalphaA, and Flk1-positive cells indicative of fibroblasts, smooth muscle, and endothelial cells; thus releasing the adult epicardium from a quiescent state and restoring pluripotency. The ability of Tbeta-4 to promote coronary vessel development and potentially induce new vasculature in the adult is essential for cardiomyocyte survival and could contribute significantly toward the reported Tbeta4-induced cardioprotection and repair in the adult heart. Tbeta-4 is currently subject to multicenter phase 1 clinical trials for treatment of cardiovascular disease (http://www.regenerx.com), therefore, insight into the repair mechanism(s) induced by Tbeta-4 is an essential step toward harnessing therapeutic survival, migration, and repair properties of the peptide in the context of acute myocardial damage

    LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group

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    We report on the discovery in the LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with a projected size of 2.56±0.072.56 \pm 0.07 Mpc projected on the sky. It is associated with the galaxy triplet UGC 9555, within which one is identified as a broad-line galaxy in the Sloan Digital Sky Survey (SDSS) at a redshift of 0.05453±1×1050.05453 \pm 1 \times 10^{-5} , and with a velocity dispersion of 215.86±6.34215.86 \pm 6.34 km/s. From archival radio observations we see that this galaxy hosts a compact flat-spectrum radio source, and we conclude that it is the active galactic nucleus (AGN) responsible for generating the radio lobes. The radio luminosity distribution of the jets, and the broad-line classification of the host AGN, indicate this GRG is orientated well out of the plane of the sky, making its physical size one of the largest known for any GRG. Analysis of the infrared data suggests that the host is a lenticular type galaxy with a large stellar mass (log M/M=11.56±0.12\log~\mathrm{M}/\mathrm{M}_\odot = 11.56 \pm 0.12), and a moderate star formation rate (1.2±0.3 M/year1.2 \pm 0.3~\mathrm{M}_\odot/\mathrm{year}). Spatially smoothing the SDSS images shows the system around UGC 9555 to be significantly disturbed, with a prominent extension to the south-east. Overall, the evidence suggests this host galaxy has undergone one or more recent moderate merger events and is also experiencing tidal interactions with surrounding galaxies, which have caused the star formation and provided the supply of gas to trigger and fuel the Mpc-scale radio lobes.Comment: Compressed for arXiv, see journal for full resolution image

    V-LoTSS: The circularly polarised LOFAR Two-metre Sky Survey

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    We present the detection of 68 sources from the most sensitive radio survey in circular polarisation conducted to date. We used the second data release of the 144 MHz LOFAR Two-metre Sky Survey to produce circularly polarised maps with a median noise of 140 µJy beam−1 and resolution of 20″ for ≈27% of the northern sky (5634 deg2). The leakage of total intensity into circular polarisation is measured to be ≈0.06%, and our survey is complete at flux densities ≥1 mJy. A detection is considered reliable when the circularly polarised fraction exceeds 1%. We find the population of circularly polarised sources is composed of four distinct classes: stellar systems, pulsars, active galactic nuclei, and sources unidentified in the literature. The stellar systems can be further separated into chromospherically active stars, M dwarfs, and brown dwarfs. Based on the circularly polarised fraction and lack of an optical counterpart, we show it is possible to infer whether the unidentified sources are likely unknown pulsars or brown dwarfs. By the completion of this survey of the northern sky, we expect to detect 300±100 circularly polarised sources
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