30 research outputs found

    Spin and orbital magnetic moment of reconstructed √2 × √2R45º magnetite(001)

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    © 2015 American Physical Society. The surface of a magnetite single crystal with (001) orientation has been prepared by sputtering/annealing cycles providing the √2×2√2R45º reconstruction. The distribution of magnetic domains on the surface has been imaged by x-ray magnetic dichroism in a photoemission microscope. The easy axes are along the surface in-plane 110 directions. The near-surface magnetic moment was determined by applying the sum rules to XMCD spectra obtained with different kinetic energies of the secondary electrons. A reduced total moment of 3.3 μB and a ratio of about 0.10 between orbital and spin moment was found, which we attribute to the surface reconstruction.Peer Reviewe

    Analysis of incidence, risk factors and clinical outcome of thromboembolic and bleeding events in 431 allogeneic hematopoietic stem cell transplantation recipients

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    This is an open-access paper.-- et al.Allogeneic hematopoietic stem cell transplantation recipients have an increasing risk of both hemorrhagic and thrombotic complications. However, the competing risks of two of these life-threatening complications in these complex patients have still not been well defined. We retrospectively analyzed data from 431 allogeneic transplantation recipients to identify the incidence, risk factors and mortality due to thrombosis and bleeding. Significant clinical bleeding was more frequent than symptomatic thrombosis. The cumulative incidence of a bleeding episode was 30.2% at 14 years. The cumulative incidence of a venous or arterial thrombosis at 14 years was 11.8% and 4.1%, respectively. The analysis of competing factors for venous thrombosis revealed extensive chronic graft-versus-host disease to be the only independent prognostic risk factor. By contrast, six factors were associated with an increased risk of bleeding; advanced disease, ablative conditioning regimen, umbilical cord blood transplantation, anticoagulation, acute III-IV graft-versus-host disease, and transplant-associated microangiopathy. The development of thrombosis did not significantly affect overall survival (P=0.856). However, significant clinical bleeding was associated with inferior survival (P<0.001). In allogeneic hematopoietic stem cell transplantation, significant clinical bleeding is more common than thrombotic complications and affects survival.Peer Reviewe

    Allogeneic Stem Cell Transplantation in Mature T Cell and Natural Killer/T Neoplasias: A Registry Study from Spanish GETH/GELTAMO Centers

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    Despite advances in understanding the biology of mature T and natural killer (NK)/T cell neoplasia, current therapies, even the most innovative ones, are still far from ensuring its cure. The only treatment to date that has been shown to control aggressive T cell neoplasms in the long term is allogeneic stem cell transplantation (alloSCT). We aim to report the results of alloSCT for advanced mature T and NK/T neoplasias performed in centers from our national GELTAMO/GETH (Grupo Español de Linfoma y Trasplante de Médula Ósea/Grupo Español de Trasplante Hematopoyético y Terapia Celular) over the past 25 years. As a secondary objective, we analyzed the results of alloSCT from haploidentical donors. We performed a retrospective analysis of all patients who received an alloSCT in Spanish centers (n = 201) from September 1995 to August 2018. The 2-year overall survival (OS) and disease-free survival (DFS) were 65.5% and 58.2%, respectively. The univariate for OS and DFS showed statistically different hazard ratios for conditioning intensity, response pre-alloSCT, comorbidity index, donor/receptor cytomegalovirus status and Eastern Cooperative Oncology Group (ECOG) pre-alloSCT, but only a better ECOG pre-alloSCT remained significant in the multivariate analysis. There was an increased incidence of relapse in those patients who did not develop chronic graft-versus-host disease (GVHD) and an increased risk of death in those developing moderate to severe acute GVHD. The 1-year nonrelapse mortality was 21.9% and was mainly due to GVHD (30%) and bacterial infections (17%). When comparing unrelated donors with haploidentical donors, we found similar results in terms of OS and DFS. There was, however, a reduction of acute GVHD in the haploidentical group (P = .04) and trend to a reduction of chronic GVHD. In conclusion, alloSCT is the only curative option for most aggressive T cell neoplasias. Haploidentical donors offer similar results to related donors in terms of survival with a reduction of acute GVHD

    The Variant rs1867277 in FOXE1 Gene Confers Thyroid Cancer Susceptibility through the Recruitment of USF1/USF2 Transcription Factors

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    In order to identify genetic factors related to thyroid cancer susceptibility, we adopted a candidate gene approach. We studied tag- and putative functional SNPs in genes involved in thyroid cell differentiation and proliferation, and in genes found to be differentially expressed in thyroid carcinoma. A total of 768 SNPs in 97 genes were genotyped in a Spanish series of 615 cases and 525 controls, the former comprising the largest collection of patients with this pathology from a single population studied to date. SNPs in an LD block spanning the entire FOXE1 gene showed the strongest evidence of association with papillary thyroid carcinoma susceptibility. This association was validated in a second stage of the study that included an independent Italian series of 482 patients and 532 controls. The strongest association results were observed for rs1867277 (OR[per-allele] = 1.49; 95%CI = 1.30–1.70; P = 5.9×10−9). Functional assays of rs1867277 (NM_004473.3:c.−283G>A) within the FOXE1 5′ UTR suggested that this variant affects FOXE1 transcription. DNA-binding assays demonstrated that, exclusively, the sequence containing the A allele recruited the USF1/USF2 transcription factors, while both alleles formed a complex in which DREAM/CREB/αCREM participated. Transfection studies showed an allele-dependent transcriptional regulation of FOXE1. We propose a FOXE1 regulation model dependent on the rs1867277 genotype, indicating that this SNP is a causal variant in thyroid cancer susceptibility. Our results constitute the first functional explanation for an association identified by a GWAS and thereby elucidate a mechanism of thyroid cancer susceptibility. They also attest to the efficacy of candidate gene approaches in the GWAS era

    Risk factors for infections caused by carbapenem-resistant Enterobacterales: an international matched case-control-control study (EURECA)

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    Cases were patients with complicated urinary tract infection (cUTI), complicated intraabdominal (cIAI), pneumonia or bacteraemia from other sources (BSI-OS) due to CRE; control groups were patients with infection caused by carbapenem-susceptible Enterobacterales (CSE), and by non-infected patients, respectively. Matching criteria included type of infection for CSE group, ward and duration of hospital admission. Conditional logistic regression was used to identify risk factors. Findings Overall, 235 CRE case patients, 235 CSE controls and 705 non-infected controls were included. The CRE infections were cUTI (133, 56.7%), pneumonia (44, 18.7%), cIAI and BSI-OS (29, 12.3% each). Carbapenemase genes were found in 228 isolates: OXA-48/like, 112 (47.6%), KPC, 84 (35.7%), and metallo-beta-lactamases, 44 (18.7%); 13 produced two. The risk factors for CRE infection in both type of controls were (adjusted OR for CSE controls; 95% CI; p value) previous colonisation/infection by CRE (6.94; 2.74-15.53; <0.001), urinary catheter (1.78; 1.03-3.07; 0.038) and exposure to broad spectrum antibiotics, as categorical (2.20; 1.25-3.88; 0.006) and time-dependent (1.04 per day; 1.00-1.07; 0.014); chronic renal failure (2.81; 1.40-5.64; 0.004) and admission from home (0.44; 0.23-0.85; 0.014) were significant only for CSE controls. Subgroup analyses provided similar results. Interpretation The main risk factors for CRE infections in hospitals with high incidence included previous coloni-zation, urinary catheter and exposure to broad spectrum antibiotics

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Línea de investigación en Helicobacter pylori para la formación de recurso humano en ciencia, tecnología e innovación en el programa de microbiología

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    Este libro nace de la unión de un maestro altamente calificado y alumnos dedicados con unas creatividades activas y dispuestas a trabajar por resolver los problemas que trae una bacteria a la humanidad. Las investigaciones aquí consignadas son producto de los trabajos de grado de los estudiantes del programa de Microbiología, quienes además fueron miembros del semillero de investigación, MICROORGANISMOS DE IMPORTANCIA EN SALUD HUMANA Y ANIMAL “OBVIO-MICROBIO”. Apoyados y dirigidos por la doctora Adalucy Alvarez-Aldana, quien gracias a su amplio conocimiento en el microorganismo supo sembrar curiosidad sobre el mismo durante las sesiones del semillero, incentivando a muchos de sus alumnos a dedicar su trabajo de grado a resolver alguna pregunta que les surgiera en torno a este microorganismo. Aunque diferentes son las investigaciones, todas fueron trazadas con un fin común, entregarle a la humanidad un poco más de conocimiento sobre Helicobacter pylori, por esto la unión de estas investigaciones en una sola consigna, son importantes para entender más sobre todo lo que rodea esta bacteria y pretenden resolver muchos misterios que aún aquejan la epidemiología detrás de la misma. Estos trabajos son fruto de muchos esfuerzos, materiales y académicos, de personas grandiosas, de la unión de universidades, doctores y docentes de diferentes disciplinas, razón que demuestra una vez más que la unión hace la fuerza, porque solo llegarás más rápido, pero en compañía llegarás más lejos. Además, contamos con la fortuna de tener un capitulo invitado, cuyo tema no es sobre Helicobacter pylori, pero si un sobre un tópico de gran interes en la actualidad como es la resistencia bacteriana. Capitulo titulado: “Caracterización epidemiológica y microbiológica de las bacteriemias y su perfil de resistencia durante el periodo junio 2011 a junio 2015”

    Diagnóstico interno del clima organizacional en una cooperativa de transportes intermunicipal de la ciudad de Palmira de conformidad al mejoramiento de su gestión administrativa

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    El ejercicio académico que fundamenta este proyecto de grado corresponde al “Diagnóstico interno del clima organizacional en una Cooperativa de Transporte Intermunicipal de Palmira. Se realiza este proyecto, en este tipo de organizaciones, primero porque son empresas de  gran dinámica de servicio, y segundo, por la complejidad interna de este tipo de compañías en cuanto a su personal que lo conforman (ejecutivos, directivos, empleados, pasantes y conductores).Sobre la base de las consideraciones anteriores, la investigación tuvo como punto de partida, el análisis de información interna, necesaria para contextualizar la situación actual y de conformidad a la identificación de las necesidades de cambio.La fase intermedia, corresponde a la revisión del nivel de eficacia del tipo de liderazgo  y estilo de gestión gerencial de la Transportadora, la idea de este proceso era medir el trato de los directivos hacia todo su personal colaborativo y hacia sus grupos de interés (clientes, proveedores, asociados).Por último, ante la situación detectada, se procedió a sintetizar todos los factores incidentales asociados al clima organizacional para plantear una propuesta de  mejoramiento administrativo

    Phase II Trial of Allogeneic Transplantation Plus Novel Drugs in Multiple Myeloma : Effect of Intensifying Reduced-Intensity Conditioning with Bortezomib and Adding Maintenance Treatment

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    The use of reduced-intensity conditioning (RIC) regimens has decreased the risk of nonrelapse mortality (NRM) after allogeneic stem cell transplantation (alloSCT). In contrast, disease relapse remains the most frequent cause of treatment failure and death. Owing to both their antimyeloma effect and immunomodulatory properties, novel drugs could improve outcomes after alloSCT. This phase II European Myeloma Network trial was designed to evaluate the combination of alloSCT with novel agents. The study was conducted to evaluate the toxicity and efficacy of RIC intensified with bortezomib (Bz) prior to alloSCT for high-risk (HR) multiple myeloma (MM) patients, as well as the efficacy of post-transplantation maintenance with Bz and lenalidomide (Len). Patients received RIC with Bz on days -9 and -2, fludarabine on days -6 to -4, and melphalan on day -3. Patients who were in complete response (CR) or near CR at day +100 post-transplantation received 6 cycles of Bz every 56 days, and the remaining received Bz, Len, and dexamethasone. Len maintenance was started on day +180 at a dose of 5 mg and continued until relapse or toxicity occurred. Of the 24 patients included, 21 were evaluable on day +100, including 12 in CR, 4 in very good partial response, 3 in partial response, and 2 with relapse or progression. The cumulative incidence (CuI) of relapse was 13.6% (95% confidence interval [CI], 3.2% to 31.3%) at 1 year and 28.5% (95% CI, 11.1% to 48.9%) at 2 years. The CuI of NRM was 21.1% (95% CI, 7.4% to 39.4%) at 2 years. With a median follow-up of 39 months (range, 1 to 67 months), the median event-free survival (EFS) was 29 months, and median overall survival (OS) was not reached. EFS and OS at 3 years were 42.5% (95% CI, 21.9% to 61.7%) and 74.01% (95% CI, 50.9% to 87.5%), respectively. The use of Bz within an RIC regimen allows for a high response rate after alloSCT. Maintenance with Bz and Len is feasible and provides remarkable results in terms of EFS and OS in HR MM patients
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