56 research outputs found

    Variabilidad en secuencias proteicas de los sistemas Toxina-Antitoxina en Mycobacterium tuberculosis

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    El agente causal de la tuberculosis es Mycobacterium tuberculosis, un patógeno dividido en 7 linajes asociados a zonas geográficas específicas y con diferencias en su comportamiento. Una característica notable en M. tuberculosis es su alto número de sistemas toxina-antitoxina, operones involucrados en la formación de células persistentes bajo situaciones de estrés. Se analizó la variabilidad en la secuencia de las proteínas de los sistemas toxina-antitoxina entre los linajes de M. tuberculosis. La predicción se hizo utilizando perfiles de modelos ocultos de Markov, seguido de un agrupamiento de genes ortólogos y posteriormente el alineamiento múltiple para la búsqueda de mutaciones. Se encontraron seis posibles antitoxinas y 63 proteínas completamente conservadas: 22 toxinas, 36 antitoxinas y 5 proteínas sin caracterizar. 41 toxinas y 18 antitoxinas presentaron mutaciones. Se encontraron mutaciones asociadas a cada linaje. Estos resultaron sugieren que en M. tuberculosis se favorece el surgimiento de nuevas antitoxinas y que las toxinas son más propensas a cambios que la antitoxinas.Abstract: Tuberculosis is caused by Mycobacterium tuberculosis. It is a pathogen divided into 7 lineages associated with specific geographical areas and with differences in their behavior. The high numbers of toxin- antitoxin systems are a notable feature in M. tuberculosis, which are operons involved in the formation of persistent cells under stress situations. The sequence variability of the toxin-antitoxin systems among the M. tuberculosis lineages was analyzed. Profiles of hidden Markov models, followed by a clustering of orthologous genes, and subsequently multiple alignments for mutations search were used to predict protein sequences. Six possible antitoxins and 63 fully conserved proteins were found: 22 toxins, 36 antitoxins and 5 uncharacterized proteins. 41 toxins and 18 antitoxins showed mutations. Mutations associated with each lineage were found. The results suggest that M. tuberculosis favors the emergence of new antitoxins and that toxins are more likely to change than antitoxins.Maestrí

    Draft Genome Sequences of 29 Helicobacter pylori Strains Isolated from Colombia

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    Here, we present the draft genome sequences of 29 Colombian Helicobacter pylori strains. These strains were isolated in Bogotá, Colombia, from patients diagnosed with chronic gastritis. The genomic characterization of these strains will provide more information on the genetic composition of H. pylori strains from Colombia.We thank the entities that financially supported the development of this work. A.B.M. is a recipient of a scholarship from the Centro de Estudios Interdisciplinarios Básicos y Aplicados (CEIBA) Foundation, Colombia; and A.B.M., C.A., J.S., and A.A.T.-R. are recipients of a project grant (120380763025/2018) from MinCiencias, Colombia. The work is partially supported by Research Vice-Rectory, Pontificia Universidad Javeriana (PPTA_7676) and F.P.I.T. BanRepCultural (project 3956). F.F.V. is financed by national funds from the Fundação para a Ciência e a Tecnologia (FCT) through an assistant researcher grant (CEECIND/03023/2017), a project grant (PTDC/BTM-SAL/28978/2017), and projects UIDB/04138/2020 and UIDP/04138/2020; these funds partially supported this work. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.info:eu-repo/semantics/publishedVersio

    Parental participation and parents’ support: effects on mathematics achievement, 2018 national assessment of learning, Mexico

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    The relationship between family involvement in students’ academic activities, their learning, and academic achievement has been widely studied. Two different types of family involvement are recognized: parental participation, which is linked to activities implemented by the school, and parental support, which occurs at home and has to do with the family’s educational practice. This study analyzed the influence of parental participation in school activities, parental support at home, and family socioeconomic status on student learning in mathematics. The database of 104,973 third-year secondary education students (50.1% female and 49.9% male) from the 2018 assessment of academic achievement in mathematical thinking was considered. Path analysis was employed in structural equation modeling, where a general model of parental support was proposed to compare the learning of students from the lowest quartile and those from the highest socioeconomic level; the model presented a good fit for each group. The models used showed acceptable adjustments in some criteria; in these models, there were positive and significant associations between parental schooling and socioeconomic level and achievement in mathematics. The results obtained are consistent with the findings of other studies in which parental support, mediated by socioeconomic status, significantly influences student learning

    Usefulness of sputum gram stain for etiologic diagnosis in community-acquired pneumonia: a systematic review and meta-analysis

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    Background: implementation of sputum Gram stain in the initial assessment of community-acquired pneumonia (CAP) patients is still controversial. We performed a systematic review and meta-analysis to investigate the usefulness of sputum Gram stain for defining the etiologic diagnosis of CAP in adult patients. Methods: we systematically searched the Medline, Embase, Science Direct, Scopus and LILACS databases for full-text articles. Relevant studies were reviewed by at least three investigators who extracted the data, pooled them using a random effects model, and carried out quality assessment. For each bacterium (Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Gram-negative bacilli), pooled sensitivity, specificity, positive and negative likelihood ratios were reported. Results: after a review of 3539 abstracts, 20 articles were included in the present meta-analysis. The studies included yielded 5619 patients with CAP. Pooled sensitivity and pooled specificity of sputum Gram stain were 0.59 (95% CI, 0.56-0.62) and 0.87 (95% CI, 0.86-0.89) respectively for S. pneumoniae, 0.78 (95% CI, 0.72-0.84) and 0.96 (95% CI, 0.94-0.97) for H. influenzae, 0.72 (95% CI, 0.53-0.87) and 0.97 (95% CI, 0.95-0.99) for S. aureus, and 0.64 (95% CI, 0.49-0.77) and 0.99 (95% CI, 0.97-0.99) for Gram-negative bacilli. Conclusion: Sputum Gram stain test is sensitive and highly specific for identifying the main causative pathogens in adult patients with CAP

    The adjusted International Prognostic Index and beta-2-microglobulin predict the outcome after autologous stem cell transplantation in relapsing/refractory peripheral T-cell lymphoma

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    BACKGROUND AND OBJECTIVES: Preliminary data on the use of autologous stem cell transplantation (ASCT) as a salvage therapy for peripheral T-cell lymphoma (PTCL) indicate that the results are similar to those obtained in aggressive B-cell lymphomas. The aim of our study was to analyze outcomes of a large series of patients with PTCL with a prolonged follow-up who received ASCT as salvage therapy. DESIGN AND METHODS: Between 1990 and 2004, 123 patients in this situation were registered in the GELTAMO database. The median age at transplantation was 43.5 years; in 91% of patients the disease was chemosensitive. RESULTS: Seventy-three percent of the patients achieved complete remission, 11% partial remission and the procedure failed in 16%. At a median follow-up of 61 months, the 5-year overall and progression-free survival rates were 45% and 34%, respectively. The presence of more than one factor of the adjusted International Prognostic Index (a-IPI) and a high beta2-microglobulin at transplantation were identified as adverse prognostic factors for both overall and progression-free survival and allowed the population to be stratified into three distinct risk groups. INTERPRETATION AND CONCLUSIONS: Our data show that approximately one third of patients with PTCL in the salvage setting may enjoy prolonged survival following ASCT, provided they are transplanted in a chemosensitive disease state. The a-IPI and beta2-microglobulin level predict the outcome after ASCT in relapsing/refractory PTCL

    Allogeneic Stem Cell Transplantation in Mantle Cell Lymphoma; Insights into Its Potential Role in the Era of New Immunotherapeutic and Targeted Therapies: The GETH/GELTAMO Experience

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    Allo-SCT is a curative option for selected patients with relapsed/refractory (R/R) MCL, but with significant NRM. We present the long-term results of patients receiving allo-SCT in Spain from March 1995 to February 2020. The primary endpoints were EFS, OS, and cumulative incidence (CI) of NRM, relapse, and GVHD. We included 135 patients, most (85%) receiving RIC. After a median follow-up of 68 months, 5-year EFS and OS were 47 and 50%, respectively. Overall and CR rates were 86 and 80%. The CI of relapse at 1 and 3 years were 7 and 12%. NRM at day 100 and 1 year were 17 and 32%. Previous ASCT and Grade 3-4 aGVHD were associated with a higher NRM. Grade 3-4 aGVHD, donor type (mismatch non-related), and the time-period 2006-2020 were independently related to worse EFS. Patients from 1995-2005 were younger, most from HLA-identical sibling donors, and were pretreated less. Our data confirmed that allo-SCT may be a curative option in R/R MCL with low a CI of relapse, although NRM is still high, being mainly secondary to aGVHD. The arrival of new, highly effective and low toxic immunotherapeutic or targeted therapies inevitably will relegate allo-SCT to those fit patients who fail these therapies, far away from the optimal timing of treatment

    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

    PENSAMIENTO CRÍTICO EN LA INVESTIGACIÓN CIENTÍFICA Y ACADÉMICA COLECCIÓN CIENTÍFICA EDUCACIÓN, EMPRESA Y SOCIEDAD

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    PENSAMIENTO CRÍTICO EN LA INVESTIGACIÓN CIENTÍFICA Y ACADÉMICA COLECCIÓN CIENTÍFICA EDUCACIÓN, EMPRESA Y SOCIEDAD Primera Edición 2023 Vol. 21 Editorial EIDEC Sello Editorial EIDEC (978-958-53018) NIT 900583173-1 ISBN: 978-628-95884-1-5 Formato: Digital PDF (Portable Document Format) DOI: https://doi.org/10.34893/e1150-3660-8721-s Publicación: Colombia Fecha Publicación: 13/09/2023 Coordinación Editorial Escuela Internacional de Negocios y Desarrollo Empresarial de Colombia – EIDEC Centro de Investigación Científica, Empresarial y Tecnológica de Colombia – CEINCET Red de Investigación en Educación, Empresa y Sociedad – REDIEES Revisión y pares evaluadores Centro de Investigación Científica, Empresarial y Tecnológica de Colombia – CEINCET Red de Investigación en Educación, Empresa y Sociedad – REDIEE

    The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars

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    The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520–1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700–900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s−1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3–4 m s−1
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