Procesos moleculares implicados en los pasos iniciales de la síntesis de los ribosomas humanos

[EN] Ribosome synthesis is an intricate process during which the transcription, modification, folding, and processing of the rRNA precursors (pre-rRNAs) are coordinated to build mature ribosome subunits. This process is driven by more than 200 ribosome biogenesis factors (RBFs) that, together with the pre-rRNAs and ribosomal proteins, form different preribosomal complexes. These complexes migrate from the nucleolus to the cytoplasm as they mature. The composition and structure of preribosomes in human cells are ill-defined and, in the case of those formed in the most internal regions of the nucleolus, this is caused by technical limitations. The main reason for those limitations is that the highly viscous nature of the inner regions of the nucleolus precludes the extraction of the complexes. The first part of this thesis is focused on the generation of tools and the development of extraction methods to characterize early nucleolar preribosomes in human cells. The initial studies were the validation of the PSE extraction method to isolate early preribosomes and the generation of cell lines that endogenously express an early RBF fused to GFP to be used as bait for preribosome purification by affinity chromatography. Using these tools, and a combination of mass-spectrometry compositional analysis and sucrose-gradient sedimentation experiments, it was found that the composition of the preribosomal subcomplex UTP-B and the function of the UTP14A protein are conserved in humans and yeast. The second part of the thesis was devoted to the functional characterization of RRP8, a methyltransferase responsible for the m1A1322 modification in the 28S rRNA. The identification of RBFs that interact with RRP8 and the characterization of the RRP8 knockout phenotype unveiled that this protein forms a module with one 40S subunit RBF that binds to the bipartite preribosome, the initial intermediate that contains the primordial precursors of both the small and large subunits. The RRP8 module is required for the efficient formation of bipartite preribosomes. The complete loss of RRP8 is well tolerated by transformed cell lines, but not by non-transformed cells indicating that its function is essential for the viability of some cell types. [ES] La síntesis de ribosomas es un proceso complejo en el que la transcripción, modificación, plegamiento y procesamiento del precursor del rRNA (pre-rRNA) se tienen que coordinar para dar lugar a la formación de las subunidades ribosómicas maduras. Este proceso es asistido por más de 200 factores de biogénesis de ribosomas (RBFs) que, junto con el pre-rRNA y las proteínas ribosómicas, van conformando diferentes complejos pre-ribosómicos. Estos complejos migran desde el nucleolo al citoplasma a medida que van madurando. En células humanas, la información disponible acerca de la composición de los pre-ribosomas, sobre todo la que se refiere a aquellos que son nucleolares y más iniciales, es muy escasa debido a que existen limitaciones técnicas para poder analizarlos bioquímicamente. Esto se debe a que las partículas pre-ribosómicas más tempranas son producidas en regiones internas del nucleolo que tienen una alta viscosidad, lo cual dificulta su extracción. La primera parte de esta tesis se centra en la generación de herramientas y el desarrollo de métodos de extracción que permitan caracterizar a los pre-ribosomas nucleolares tempranos de células humanas. Primero, se realizó una validación del método de extracción PSE y se generaron líneas celulares que expresan endógenamente un RBF fusionado a la GFP, para utilizarlo como cebo de purificación de pre-ribosomas tempranos por cromatografía de afinidad. Seguidamente, utilizando esas herramientas en combinación con análisis composicionales por espectrometría de masas y experimentos de sedimentación en gradientes de sacarosa, se comprobó que la composición del subcomplejo pre-ribosómico UTP-B y que la función de la proteína UTP14A están conservados en células humanas y células de levadura. En la segunda parte de la tesis se realizó un estudio de caracterización funcional de la proteína RRP8, la metiltransferasa que introduce la modificación m1A1322 en el rRNA 28S. La identificación de RBFs que interaccionan con RRP8 y la caracterización del fenotipo inducido por su silenciamiento o eliminación total evidenciaron que esta proteína forma un módulo con un RBF de la subunidad 40S que se une y es importante para la producción eficiente del pre-ribosoma bipartito, el intermediario inicial que contiene todavía unidos los precursores prematuros de la subunidad pequeña y de la subunidad grande. Aunque la pérdida de RRP8 es bien tolerada por células transformadas en cultivo, no lo es en células no transformadas, lo cual revela que su función es esencial en algunos tipos celulares

Elaboración e implementación de un nuevo programa de prácticas de laboratorio para una asignatura de grado de Biología Molecular

Memoria ID-191. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020

HTLV-1 infection in solid organ transplant donors and recipients in Spain

HTLV-1 infection is a neglected disease, despite infecting 10-15 million people worldwide and severe illnesses develop in 10% of carriers lifelong. Acknowledging a greater risk for developing HTLV-1 associated illnesses due to immunosuppression, screening is being widely considered in the transplantation setting. Herein, we report the experience with universal HTLV testing of donors and recipients of solid organ transplants in a survey conducted in Spain. All hospitals belonging to the Spanish HTLV network were invited to participate in the study. Briefly, HTLV antibody screening was performed retrospectively in all specimens collected from solid organ donors and recipients attended since the year 2008. A total of 5751 individuals were tested for HTLV antibodies at 8 sites. Donors represented 2312 (42.2%), of whom 17 (0.3%) were living kidney donors. The remaining 3439 (59.8%) were recipients. Spaniards represented nearly 80%. Overall, 9 individuals (0.16%) were initially reactive for HTLV antibodies. Six were donors and 3 were recipients. Using confirmatory tests, HTLV-1 could be confirmed in only two donors, one Spaniard and another from Colombia. Both kidneys of the Spaniard were inadvertently transplanted. Subacute myelopathy developed within 1 year in one recipient. The second recipient seroconverted for HTLV-1 but the kidney had to be removed soon due to rejection. Immunosuppression was stopped and 3 years later the patient remains in dialysis but otherwise asymptomatic. The rate of HTLV-1 is low but not negligible in donors/recipients of solid organ transplants in Spain. Universal HTLV screening should be recommended in all donor and recipients of solid organ transplantation in Spain. Evidence is overwhelming for very high virus transmission and increased risk along with the rapid development of subacute myelopathy

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Soy Niña

Este libro pretende contribuir al reencuentro de la educación con esas finalidades que verdaderamente importan a una niña o un niño: ser feliz, jugar, vivir juntos y (no) aprender. Para ello hemos puesto el arte, nuestras experiencias y el saber acumulado al servicio del disfrute, el cuestionamiento, el análisis crítico y la construcción común de un presente deseable. Un texto colaborativo coordinado por Ignacio Calderón Almendros y realizado por alumnado de Educación y Cambio Social en el Grado en Educación Infantil de la Universidad de Málaga

Çédille, revista de estudios franceses

Presentació

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Synthetic control of correlated disorder in UiO-66 frameworks [Dataset]

Raw data associated to the Figures 2, 3, 4, 5 and 7 in the main text.LIVINGPORE – Bringing Nanospace to Life by Adapting Pore Environments to Chemical Complexity 101043428 European CommissionPeer reviewe

Synthetic control of correlated disorder in UiO-66 frameworks

Abstract Changing the perception of defects as imperfections in crystalline frameworks into correlated domains amenable to chemical control and targeted design might offer opportunities for the design of porous materials with superior performance or distinctive behavior in catalysis, separation, storage, or guest recognition. From a chemical standpoint, the establishment of synthetic protocols adapted to control the generation and growth of correlated disorder is crucial to consider defect engineering a practicable route towards adjusting framework function. By using UiO-66 as experimental platform, we systematically explored the framework chemical space of the corresponding defective materials. Periodic disorder arising from controlled generation and growth of missing cluster vacancies can be chemically controlled by the relative concentration of linker and modulator, which has been used to isolate a crystallographically pure “disordered” reo phase. Cs-corrected scanning transmission electron microscopy is used to proof the coexistence of correlated domains of missing linker and cluster vacancies, whose relative sizes are fixed by the linker concentration. The relative distribution of correlated disorder in the porosity and catalytic activity of the material reveals that, contrarily to the common belief, surpassing a certain defect concentration threshold can have a detrimental effect

Rapid decrease in titer and breadth of neutralizing anti-HCV antibodies in HIV/HCV-coinfected patients who achieved SVR

The main targets for neutralizing anti-hepatitis C virus (HCV) antibodies (HCV-nAbs) are the E1 and E2 envelope glycoproteins. We have studied the characteristics of HCV-nAbs through a retrospective study involving 29 HIV/HCV-coinfected patients who achieved sustained virological response (SVR) with peg-IFNα + ribavirin anti-HCV therapy. Plasma samples at baseline and week 24 after SVR were used to perform neutralization assays against five JFH1-based HCV recombinant viruses coding for E1 and E2 from genotypes 1a (H77), 1b (J4), 2a (JFH1), 3a (S52) and 4a (ED43). At baseline, the majority of plasma samples neutralized 1a, 1b, 2a, and 4a, but not 3a, genotypes. Twenty-four weeks following SVR, most neutralizing titers declined substantially. Furthermore, titers against 3a and 2a were not detected in many patients. Plasma samples with high HCV-nAb titers neutralized all genotypes, and the highest titers at the starting point correlated with the highest titers at week 24 after SVR. In conclusion, high titers of broad-spectrum HCV-nAbs were detected in HIV/HCV-coinfected individuals, however, those titers declined soon after SVR