X-ray Spectral Survey of WGACAT Quasars, II: Optical and Radio Properties of Quasars with Low Energy X-ray Cut-offs

We have selected quasars with X-ray colors suggestive of a low energy cut-off, from the ROSAT PSPC pointed archive. We examine the radio and optical properties of these 13 quasars. Five out of the seven quasars with good optical spectra show associated optical absorption lines, with two having high delta-v candidate systems. Two other cut-off quasars show reddening associated with the quasar. We conclude that absorption is highly likely to be the cause of the X-ray cut-offs, and that the absorbing material associated with the quasars, not intervening along the line-of-sight. The suggestion that Gigahertz Peaked Sources are associated with X-ray cut-offs remains unclear with this expanded sample.Comment: 17 pages, LaTeX, including 2 Tables and 1 figure. Ap.J. in pres

The Chandra COSMOS Survey, I: Overview and Point Source Catalog

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area with an effective exposure of ~80ksec. The limiting source detection depths are 1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) band, 7.3e(-16) erg cm^-2 s^-1 in the Hard (2-10 keV) band, and 5.7e(-16) erg cm(-2) s(-1) in the Full (0.5-10 keV) band. Here we describe the strategy, design and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of <2e(-5) (1655 in the Full, 1340 in the Soft, and 1017 in the Hard bands). By using a grid of 36 heavily (~50%) overlapping pointing positions with the ACIS-I imager, a remarkably uniform (to 12%) exposure across the inner 0.5 sq.deg field was obtained, leading to a sharply defined lower flux limit. The widely different PSFs obtained in each exposure at each point in the field required a novel source detection method, because of the overlapping tiling strategy, which is described in a companion paper. (Puccetti et al. Paper II). This method produced reliable sources down to a 7-12 counts, as verified by the resulting logN-logS curve, with sub-arcsecond positions, enabling optical and infrared identifications of virtually all sources, as reported in a second companion paper (Civano et al. Paper III). The full catalog is described here in detail, and is available on-line.Comment: Revised to omit egregious bold facing and fix missing ',' in author lis

The role of Extracellular Vesicles (EVs) in Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Lobar Degeneration (FTLD)

ALS and FTLD are neurodegenerative diseases characterized by pathological ubiquitinated and phosphorilated inclusions in the cytosol of affected cells. In 98% of ALS and in the majority of Tau-negative FTLD cases the main component is the TAR DNA-binding protein of 43 KDa (TDP-43) together with its C-terminal fragments of 35 (TDP-35) and 25 KDa (TDP-25). TDP-inclusions are mainly removed from cells via the protein quality control (PQC) system, but they could also be secreted within extracellular vesicles (EVs). In our work we first analysed the TDP-content of the EVs, by comparing large (LVs) with small vesicles (SVs); then, we evaluated the presence of some PQC-members. Finally, we investigated the effect of PQC blockage on EVs secretion and content. Methods. We isolated EVs produced by NSC34 cells untreated or treated with MG132 or NH4Cl (proteasome and autophagy inhibitors). To isolate EVs we used the differential ultracentrifugation method. We analysed EVs size, count and morphology through the Nanoparticle Tracking Analysis and the transmission electron microscopy, and their protein content through western blot analysis. Results. We showed that both TDP-43 and its C-terminal fragments (especially TDP-35) are secreted in EVs, mainly in LVs. Interestingly, in cells TDPs are present as soluble forms, instead the secreted TDPs are mainly insoluble. We found that many PQC-components are secreted in EVs and PQC modulation resulted in a significant increase in EVs numbers, that is paralleled by a slight increase in TDP-content. Summary/Conclusion. EVs may positively contribute to the clearance of insoluble TDPs species by cooperating with PQC, having a protective role for affected cells. However, they may also contribute to the prion-like distribution of TDP-neurotoxic forms in neighboring and more distant cells

Adult T-cell acute lymphoblastic leukemia: biologic profile at presentation and correlation with response to induction treatment in patients enrolled in the GIMEMA LAL 0496 protocol

Between 1996 and 2000, 90 newly diagnosed adult patients with T-acute lymphoblastic leukemia (T-ALL) were registered in the Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) Leucemia Acuta Limfoide (LAL) 0496 protocol. Cases were centrally processed for morphology, immunophenotype, cytogenetics, molecular biology, and multidrug resistance (MDR). Twenty-two patients were females and 68 were males. Four percent of cases were pro-T, 47% pre-T, 39% cortical T, and 10% mature T-ALL. Fifty-six percent of patients with pro-T + pre–T-ALL achieved complete remission (CR) compared with 91% for cortical + mature cases (P = .002). CD34 expression was associated with a significantly lower CR rate: 54% versus 84% (P = .009). Thirty-one (36.5%) of 85 patients had an abnormal karyotype, the most common abnormality (15%) being a partial del(6q). The cytogenetic profile did not impact on CR achievement. MDR1 function, present in 26% of cases, correlated significantly with CR achievement (P = .004). A highly significant (P = .001) difference in CR rate was observed between patients who did not express the CD13/CD33/CD34 antigens and were MDR functionally negative (96%) compared with patients positive for at least one of these markers (57%). Multivariate analysis showed an impact on CR achievement for CD33 expression and MDR1 function. An extensive biologic workup of adult T-ALL cases at presentation is recommended in order to design tailored therapeutic strategies aimed at improving CR rates