Discovery of novel pathways of microbial arginine biosynthesis

The amino acid L-arginine is an essential component of all living organisms. Its importance resides in the variety of functions that arginine itself, along with some intermediary metabolites involved in its de novo synthesis in the cell. In many prokaryotes, fungi, and plants the de novo biosynthesis of arginine proceeds from glutamate in eight enzymatic steps (Figure 2). The first committed step of this pathway is the N-acetylation of glutamate. Acetylation of the early precursors of arginine distinguishes them from the analogous intermediates in the biosynthesis of proline. Although each and every step of the pathway is essential for its completion, transcarbamylation of ornithine to produce citrulline is one of the crucial steps in the pathway. This reaction is catalyzed by the enzyme ornithine transcarbamylase (OTC). The transcarbamylases family of enzymes belongs to the carboxyl- and carbamoyltransferases group, EC 2.1.3, a family that comprises enzymes that catalyze the transfer of a carbamoyl group from carbamylphosphate (CP) to an amino or oxygen group of a second substrate. Members of the transcarbamylase family can be identified based on sequence identities in the N-terminal or CP-binding domain as all the members of this family share common residues involved in the binding of CP to the enzyme. All the evolutionary conserved motifs present in the transcarbamylase family have led to the erroneous annotation of a large, yet increasing, number of genes as OTCases without experimental confirmation of such activity. The case of the transcarbamylase-like gene found in B. fragilis illustrates this statement. The present thesis work is focused in the case of two families of misannotated microbial transcarbamylases that have been identified as essential for arginine biosynthesis, but which lacked the ability to catalyze the conversion of ornithine into citrulline. The objectives of the present thesis work are the biochemical and molecular characterization of the N-acetylornithine transcarbamylase (AOTC) activity of XcArgF’ as well as the elucidation of the enzymatic activity of BfArgF’ and its biochemical and molecular characterization. We show that Xanthomonads and Bacteroidetes use novel pathways for the de novo arginine biosynthesis mediated by acetyl- and succinyl-ornithine transcarbamylases, we identify a recognition motif for these enzymes and we provide evidence supporting the view that the existence of succinyl-ornithine transcarbamylase requires that the first five steps of the arginine biosynthesis pathway use succinylated rather than acetylated intermediates

Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Withdrawal Is Associated with Higher Mortality in Hospitalized Patients with COVID-19

Our main aim was to describe the effect on the severity of ACEI (angiotensin-converting enzyme inhibitor) and ARB (angiotensin II receptor blocker) during COVID-19 hospitalization. A retrospective, observational, multicenter study evaluating hospitalized patients with COVID-19 treated with ACEI/ARB. The primary endpoint was the incidence of the composite outcome of prognosis (IMV (invasive mechanical ventilation), NIMV (non-invasive mechanical ventilation), ICU admission (intensive care unit), and/or all-cause mortality). We evaluated both outcomes in patients whose treatment with ACEI/ARB was continued or withdrawn. Between February and June 2020, 11,205 patients were included, mean age 67 years (SD = 16.3) and 43.1% female; 2162 patients received ACEI/ARB treatment. ACEI/ARB treatment showed lower all-cause mortality (p < 0.0001). Hypertensive patients in the ACEI/ARB group had better results in IMV, ICU admission, and the composite outcome of prognosis (p < 0.0001 for all). No differences were found in the incidence of major adverse cardiovascular events. Patients previously treated with ACEI/ARB continuing treatment during hospitalization had a lower incidence of the composite outcome of prognosis than those whose treatment was withdrawn (RR 0.67, 95%CI 0.63-0.76). ARB was associated with better survival than ACEI (HR 0.77, 95%CI 0.62-0.96). ACEI/ARB treatment during COVID-19 hospitalization was associated with protection on mortality. The benefits were greater in hypertensive, those who continue

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group

SARS-CoV-2 viral load in nasopharyngeal swabs is not an independent predictor of unfavorable outcome

The aim was to assess the ability of nasopharyngeal SARS-CoV-2 viral load at first patient’s hospital evaluation to predict unfavorable outcomes. We conducted a prospective cohort study including 321 adult patients with confirmed COVID-19 through RT-PCR in nasopharyngeal swabs. Quantitative Synthetic SARS-CoV-2 RNA cycle threshold values were used to calculate the viral load in log10 copies/mL. Disease severity at the end of follow up was categorized into mild, moderate, and severe. Primary endpoint was a composite of intensive care unit (ICU) admission and/or death (n = 85, 26.4%). Univariable and multivariable logistic regression analyses were performed. Nasopharyngeal SARS-CoV-2 viral load over the second quartile (≥ 7.35 log10 copies/mL, p = 0.003) and second tertile (≥ 8.27 log10 copies/mL, p = 0.01) were associated to unfavorable outcome in the unadjusted logistic regression analysis. However, in the final multivariable analysis, viral load was not independently associated with an unfavorable outcome. Five predictors were independently associated with increased odds of ICU admission and/or death: age ≥ 70 years, SpO2, neutrophils > 7.5 × 103/µL, lactate dehydrogenase ≥ 300 U/L, and C-reactive protein ≥ 100 mg/L. In summary, nasopharyngeal SARS-CoV-2 viral load on admission is generally high in patients with COVID-19, regardless of illness severity, but it cannot be used as an independent predictor of unfavorable clinical outcome

Manual de simulación clínica en especialidades médicas

Manual sobre técnicas y modos de simulación clínica en diversas especialidades médicas.La enseñanza y formación en medicina necesita el uso de la simulación. Existen evidencias de su uso desde hace cientos de años, pero, en los últimos años se ha incrementado y diseminado. La simulación clínica está validada científicamente en múltiples contextos médicos y de otras áreas profesionales de la salud. Y es considerada de gran importancia como proceso de entrenamiento y de mejora de las competencias y adquisición de habilidades médicas en campos que incluye desde la historia clínica, comunicación con el paciente, exploración, diagnóstico terapéutica médica-farmacológica y quirúrgica y seguridad al tratar al paciente. Hoy en día, para muchas técnicas y situaciones clínicas es inaceptable llegar junto a los pacientes sin un dominio adquirido en simulación. La simulación puede ocurrir sin el uso de recursos adicionales, solo las personas, o utilizando pocos o muchos recursos de baja hasta alta tecnología y se puede adaptar a los recursos disponibles, abarcando todas las áreas de conocimiento, y dentro de ellas competencias técnicas o actitudes, solas o en conjunto. El uso racional y basado en evidencia de la simulación es de la mayor importancia por la necesidad de una mayor efectividad y eficiencia en la transformación de los profesionales de la salud para que puedan mejorar su capacidad de atender a los pacientes. La simulación es también una buena herramienta de evaluación de competencias y habilidades en Medicina y otras disciplinas de las Ciencias de la Salud Este manual incluye técnicas y modos de simulación clínica en diversas especialidades médicas, útiles, para quien busque un manual práctico y actualizado.Cátedra de Mecenazgo de la Universidad de Málaga. Cátedra de Terapias Avanzadas en Patología Cardiovascular Cátedra de Mecenazgo de la Universidad de Málaga. Cátedra de Investigación Biomédica Quirón Salu

A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS

Funding: TGW, ACC, and KH acknowledge support from STFC consolidated grant numbers ST/R000824/1 and ST/V000861/1, and UKSA grant ST/R003203/1.We report the discovery and characterization of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in the Transiting Exoplanet Survey Satellite (TESS) photometry. To characterize the system, we performed and retrieved the CHaracterising ExOPlanets Satellite (CHEOPS), TESS, and ground-based photometry, the High Accuracy Radial velocity Planet Searcher (HARPS) high-resolution spectroscopy, and Gemini speckle imaging. We characterize the host star and determine Teff,⋆=4734±67K⁠, R⋆=0.726±0.007R⊙⁠, and M⋆=0.748±0.032M⊙⁠. We present a novel detrending method based on point spread function shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of Pb = 6.44387 ± 0.00003 d, a radius of Rb = 2.59 ± 0.04 R⊕, and a mass of Mb=13.5+1.7−1.8 M⊕, whilst TOI-1064 c has an orbital period of Pc=12.22657+0.00005−0.00004 d, a radius of Rc = 2.65 ± 0.04 R⊕, and a 3σ upper mass limit of 8.5 M⊕. From the high-precision photometry we obtain radius uncertainties of ∼1.6 per cent, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterized sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further radial velocities are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass–radius space, and it allow us to identify a trend in bulk density–stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets.Publisher PDFPeer reviewe

Ensayos sobre aplicación de la Teoría del Estado en las algunas culturas del Perú antiguo

Investigations of State Theory on the cultures of ancient Peru.Capítulos de libro con investigaciones de Teoría del Estado sobre las culturas del Perú antiguo, realizado por docentes y estudiantes de la Escuela Profesional de Derecho de la Universidad Nacional del Altiplano de Puno.      

Ensayos sobre aplicación de la Teoría del Estado en las algunas culturas del Perú antiguo

Investigations of State Theory on the cultures of ancient Peru.Capítulos de libro con investigaciones de Teoría del Estado sobre las culturas del Perú antiguo, realizado por docentes y estudiantes de la Escuela Profesional de Derecho de la Universidad Nacional del Altiplano de Puno.      

Ensayos sobre aplicación de la Teoría del Estado en las algunas culturas del Perú antiguo

Investigations of State Theory on the cultures of ancient Peru.Capítulos de libro con investigaciones de Teoría del Estado sobre las culturas del Perú antiguo, realizado por docentes y estudiantes de la Escuela Profesional de Derecho de la Universidad Nacional del Altiplano de Puno.