Central role of the ramAR locus in the multidrug resistance in ESBL-Enterobacterales.

The aim of this study was to evaluate the proportion of resistance to a temocillin, tigecycline, ciprofloxacin, and chloramphenicol phenotype called t2c2 that resulted from mutations within the ramAR locus among extended-spectrum ß-lactamases-Enterobacterales (ESBL-E) isolated in three intensive care units for 3 years in a French university hospital. Two parallel approaches were performed on all 443 ESBL-E included: (i) the minimal inhibitory concentrations of temocillin, tigecycline, ciprofloxacin, and chloramphenicol were determined and (ii) the genomes obtained from the Illumina sequencing platform were analyzed to determine multilocus sequence types, resistomes, and diversity of several tetR-associated genes including ramAR operon. Among the 443 ESBL-E strains included, isolates of Escherichia coli (n = 194), Klebsiella pneumoniae (n = 122), and Enterobacter cloacae complex (Ecc) (n = 127) were found. Thirty-one ESBL-E strains (7%), 16 K. pneumoniae (13.1%), and 15 Ecc (11.8%) presented the t2c2 phenotype in addition to their ESBL profile, whereas no E. coli presented these resistances. The t2c2 phenotype was invariably reversible by the addition of Phe-Arg-ß-naphthylamide, indicating a role of resistance-nodulation-division pumps in these observations. Mutations associated with the t2c2 phenotype were restricted to RamR, the ramAR intergenic region (IR), and AcrR. Mutations in RamR consisted of C- or N-terminal deletions and amino acid substitutions inside its DNA-binding domain or within key sites of protein-substrate interactions. The ramAR IR showed nucleotide substitutions involved in the RamR DNA-binding domain. This diversity of sequences suggested that RamR and the ramAR IR represent major genetic events for bacterial antimicrobial resistance.IMPORTANCEMorbimortality caused by infectious diseases is very high among patients hospitalized in intensive care units (ICUs). A part of these outcomes can be explained by antibiotic resistance, which delays the appropriate therapy. The transferable antibiotic resistance gene is a well-known mechanism to explain the high rate of multidrug resistance (MDR) bacteria in ICUs. This study describes the prevalence of chromosomal mutations, which led to additional antibiotic resistance among MDR bacteria. More than 12% of Klebsiella pneumoniae and Enterobacter cloacae complex strains presented mutations within the ramAR locus associated with a dysregulation of an efflux pump called AcrAB-TolC and a porin: OmpF. These dysregulations led to an increase in antibiotic output notably tigecycline, ciprofloxacin, and chloramphenicol associated with a decrease of input for beta-lactam, especially temocillin. Mutations within transcriptional regulators such as ramAR locus played a major role in antibiotic resistance dissemination and need to be further explored.

Major primary bile salts repress Salmonella enterica serovar Typhimurium invasiveness partly via the efflux regulatory locus ramRA.

Bile represses Salmonella enterica serovar Typhimurium (S. Typhimurium) intestinal cell invasion, but it remains unclear which bile components and mechanisms are implicated. Previous studies reported that bile inhibits the RamR binding to the ramA promoter, resulting in ramA increased transcription, and that ramA overexpression is associated to decreased expression of type III secretion system 1 (TTSS-1) invasion genes and to impaired intestinal cell invasiveness in S. Typhimurium. In this study, we assessed the possible involvement of the ramRA multidrug efflux regulatory locus and individual bile salts in the bile-mediated repression of S. Typhimurium invasion, using Caco-2 intestinal epithelial cells and S. Typhimurium strain ATCC 14028s. Our results indicate that (i) major primary bile salts, chenodeoxycholate and its conjugated-derivative salts, cholate, and deoxycholate, activate ramA transcription in a RamR-dependent manner, and (ii) it results in repression of hilA, encoding the master activator of TTSS-1 genes, and as a consequence in the repression of cellular invasiveness. On the other hand, crude ox bile extract and cholate were also shown to repress the transcription of hilA independently of RamR, and to inhibit cell invasion independently of ramRA. Altogether, these data suggest that bile-mediated repression of S. Typhimurium invasion occurs through pleiotropic effects involving partly ramRA, as well as other unknown regulatory pathways. Bile components other than the bile salts used in this study might also participate in this phenomenon.

Antibiotics do not induce expression of acrAB directly but via a RamA-dependent pathway.

The aim of this study was to determine if acrAB induction in Salmonella Typhimurium relies solely on RamA or if other transcriptional activator pathways are also involved, and to better understand the kinetics of induction of both acrAB and ramA. We evaluated the expression of acrAB in S. Typhimurium in response to a variety of compounds that are known to induce the expression of one or more of the transcriptional activators, MarA, SoxS, RamA, and Rob. We utilized green fluorescent protein (GFP) transcriptional reporter fusions to investigate the changes in the expression of acrAB, ramA, marA, and soxS following exposure to sub-inhibitory concentrations of antimicrobial compounds. Of the compounds tested, 13 induce acrAB expression in S. Typhimurium via RamA, MarA, SoxS, and Rob-dependent pathways. None of the tested antibiotics induced acrAB expression, and compounds that induced acrAB expression also induced a general stress response. The results from this study show that the majority of compounds tested induced acrAB via the RamA-dependent pathway. However, none of the antibiotic substrates of the AcrB efflux pump directly increased the expression of AcrAB either directly or indirectly via the induction of one of the transcriptional activators. Using a dual GFP/RFP reporter, we investigated the kinetics of the induction of ramA and acrAB simultaneously and found that acrAB gene expression was transient compared to ramA gene expression. ramA gene expression increased with time and would remain high or decrease slowly over the course of the experiment indicating that RamA exerts a wider global effect and is not limited to efflux regulation alone.

Mechanical Evaluation of Different Stable Internal Fixation Techniques of Sagittal Osteotomy in Mandibular Advance / Evaluación Mecánica de Diferentes Técnicas de Fijación Interna Estable de Osteotomía Sagital en Avance Mandibular

The mandibular advancements performed in orthognathic surgeries can be stabilized with several techniques when using stable internal fixation. This study aims to comparatively evaluate, in vitro, the mechanical strength in a polyurethane mandibular model for four fixation techniques for sagittal split ramus osteotomy mandibular. 60 samples were divided into 4 groups, with 15 units for each group: group A, group B, group C and group D. Advances of 5 mm were made for each subgroup and fixed with 2.0 mm system plates and monocortical screws in the replicas of human hemimandibles in polyurethane resin. The samples were submitted to mechanical tests of linear loading, being evaluated the peak load and peak deformation. Technique B presented higher peak load (Kgf) and techniques A and B presented higher peak strain (p<0.05). Technique D presented lower peak load and lower peak strain (p<0.05). It is concluded that the study based on the development of new techniques for fixation for sagittal osteotomy of the mandibular ramus is of great importance for the advancement of orthognathic surgery, provided by the technical innovation of more favorable plate models.

Los avances mandibulares realizados en cirugías ortognáticas pueden estabilizarse con varias técnicas cuando se utiliza fijación interna estable. Este estudio tuvo como objetivo evaluar comparativamente, in vitro, la resistencia mecánica en un modelo mandibular de poliuretano para cuatro técnicas de fijación para la osteotomía sagital de la rama mandibular. Se dividieron 60 muestras en 4 grupos, con 15 unidades para cada grupo: grupo A, grupo B, grupo C y grupo D. Se realizaron avances de 5 mm para cada subgrupo y se fijaron con placas de sistema de 2,0 mm y tornillos monocorticales en las réplicas de hemimandíbulas humanas en resina de poliuretano. Las muestras fueron sometidas a pruebas mecánicas de carga lineal, siendo evaluadas la carga máxima y la deformación máxima. La técnica B presentó mayor pico de carga (Kgf) y las técnicas A y B presentaron mayor pico de deformación (p<0,05). La técnica D presentó menor carga máxima y menor tensión máxima (p<0,05). Se concluye que el estudio basado en el desarrollo de nuevas técnicas de fijación para la osteotomía sagital de la rama mandibular es de gran importancia para el avance de la cirugía ortognática, proporcionada por la innovación técnica de modelos de placas más favorables.

Comparação da fragilidade gerada por 3 diferentes osteotomias sagitais de mandíbula: estudo in vitro / Comparison of fragility generated by 3 different sagittal mandible osteotomies: in vitro study / Comparación de la fragilidad generada por 3 osteotomías mandibulares sagitales diferentes: estudio in vitro

A osteotomia sagital bilateral de mandíbula (OSBM) foi publicada por Trauner e Obwegeser em 1957, desde então sofreu várias modificações a fim de diminuir as complicações e tornar o procedimento mais simples e previsível. Sendo assim objetivo do presente trabalho foi avaliar e comparar a fragilidade causada na mandíbula por 3 tipos de OSBM. Para isso, foram realizadas as osteotomias propostas por Trauner e Obwegeser modificada por Hunsuck e Epker (I), a de Sant'Ana (II) e de Wolford (III), em 24 hemimandibulas de poliuretano e foi realizado o ensaio mecânico para gerar a fratura sagital. Os dados foram coletados e tabulados, e obteve como resultado que, a maior quantidade de força máxima aplicada foi observada no grupo III, e a menor quantidade no grupo II; com relação à deflexão, apresentou significância estatística entre o grupo II e grupo III; com relação à rigidez, a maior média, foi encontrada no grupo I. Sendo assim, foi possível concluir que dentro deste modelo de estudo a osteotomia II foi capaz de gerar maior fragilidade à hemimandibula de poliuretano com menor quantidade de força. As OBMD dos grupos I e a III também apresentaram ótimos resultados, entretanto necessitaram mais força para alcançar a fratura... (AU)

The bilateral sagittal split osteotomy of the mandible (BSSO) was published by Trauner and Obwegeser in 1957, since then it has undergone several modifications in order to reduce complications and make the procedure simpler and more predictable. Therefore, the objective of this study was to evaluate and compare the fragility caused in the mandible by 3 types of BSSO. For this, the osteotomies proposed by Trauner and Obwegeser modified by Hunsuck and Epker (I), Sant'Ana (II) and Wolford (III) were performed on 24 polyuretha ne hemimandibles, a mechanical test to generate the sagittal fracture. Data were collected and tabulated, and the result was that, the highest amount of maximum force applied was observed in group III, and the lowest amount in group II; with regard to deflection, it was statistically significant between group II and group III; with regard to stiffness, the highest average was found in group I. Therefore, it was possible to conclude that within this study model, osteotomy II was able to generate greater fragility to the polyurethane hemimandible with less force. The BSSO of the groups I and III also showed excelent results, however they required more force to reach the fracture... (AU)

La osteotomía sagital bilateral de la mandíbula (OSBM) fue publicada por Trauner y Obwegeser en 1957, desde entonces ha sufrido varias modificaciones con el fin de reducir las complicaciones y hacer el procedimiento más simple y predecible. Por lo tanto, el objetivo de este estudio fue evaluar y comparar la fragilidad causada en la mandíbula por 3 tipos de OSBM. Para eso, se realizaron las osteotomías propuestas por Trauner y Obwegeser modificadas por Hunsuck y Epker (I), Sant'Ana (II) y Wolford (III) en 24 hemimandíbulas de poliuretano y se realizó un ensayo mecánico para generar la fractura sagital. Los datos fueron recolectados y tabulados, obteniendo como resultado que, la mayor cantidad de fuerza máxima aplicada se observó en el grupo III, y la menor cantidad en el grupo II; en cuanto a la deflexión, fue estadísticamente significativa entre el grupo II y el grupo III; en cuanto a la rigidez, la media más alta se encontró en el grupo I. Por lo tanto, se pudo concluir que, dentro de este modelo de estudio, la osteotomía II logró generar mayor fragilidad a la hemimandíbula de poliuretano con menor fuerza. El OSBM de los grupos I y III también mostró excelentes resultados, pero requirieron mayor fuerza para llegar a la fractura... (AU)

Riesgo arrítmico en episodios únicos o recurrentes de síncope inexplicado con bloqueo completo de rama / Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block

Introducción y objetivos: Los pacientes con un episodio sincopal inexplicable único (ESU) y bloqueo completo de rama del haz de His (BcR) con frecuencia se tratan de manera más conservadora que aquellos con episodios recurrentes (ESR). El objetivo fue analizar si existen diferencias entre pacientes con ESU o ESR y BcR en cuanto al riesgo arrítmico, el rendimiento diagnóstico de las pruebas y los resultados clínicos. Métodos: Estudio de cohorte de pacientes consecutivos con seguimiento medio de 3 años. Fueron estudiados mediante un protocolo escalonado basado en un estudio electrofisiológico y seguimiento con un monitor cardiaco implantable (MCI). Resultados: De los 503 pacientes incluidos en el estudio, 238 (47,3%) referían un ESU. El riesgo de síncope arrítmico fue similar en ambos grupos (58,8% ESU frente a 57,0% ESR; p=0,68), también tras ajustar por variables de confusión (HR=1,06; IC95%, 0,81-1,38; p=0,674). No se encontraron diferencias significativas en cuanto a los resultados del estudio electrofisiológico y la rentabilidad diagnóstica del monitor cardiaco implantable. Un total de 141 (59,2%) pacientes con ESU y 154 (58,1%) con ESR requirieron el implante de un dispositivo cardiaco (p=0,797). Tras el tratamiento adecuado, 35 (7%) pacientes presentaron recurrencia del síncope. La tasa de recurrencia y la mortalidad también fueron similares. Conclusiones: Los pacientes con BcR y síncope tienen un alto riesgo de tener una etiología arrítmica, aunque solo hayan presentado un episodio aislado. Los pacientes con ESU y ESR tienen un riesgo arrítmico similar y presentan un pronóstico similar, por lo que no existe una justificación clínica para no tratarlos de la misma manera.(AU)

Introduction and objectives: Patients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. Methods: Cohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. Results: Of the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. Conclusions: Patients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.(AU)

A Clinical and Anatomical Study on the Localization of the Temporal Branch of the Facial Nerve Crossing the Zygomatic Arch / Estudio Clínico y Anatómico sobre la Localización del Ramo Temporal del Nervio Facial que Cruza el Arco Cigomático

SUMMARY: To clarify the path of the temporal branch of facial nerve (TB) crossing the zygomatic arch (ZA). Eighteen fresh adult heads specimens were carefully dissected in the zygomatic region, with the location of TB as well as its number documented. The hierarchical relationship between the temporal branch and the soft tissue in this region was observed on 64 P45 plastinated slices. 1. TB crosses the ZA as type I (21.8 %), type II (50.0 %,), and type III (28.1 %) twigs. 2. At the level of the superior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 36.36±6.56 mm, for the posterior trunk is 25.59±5.29 mm. At the level of the inferior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 25.77±6.19 mm, for the posterior trunk is 19.16±4.71 mm. 3. The average length of ZA is 62.06±5.36 mm. TB crosses the inferior edge of the ZA at an average of 14.67±6.45 mm. TB crosses the superior edge of the ZA at an average of 9.08±4.54 mm. 4. At the level of the ZA, TB passes on the surface of the pericranium while below the SMAS. The TB obliquely crosses the middle 1/3 part of the superior margin of the ZA and the junction of the middle 1/3 part and the posterior 1/3 part of the inferior margin of the ZA below the SMAS while beyond the periosteum. It is suggested that this area should be avoided in clinical operation to avoid the injury of TB.

El objetivo de estudio fue esclarecer el trayecto del ramo temporal del nervio facial (RT) que cruza el arco cigomático (AC). Se disecaron la región cigomática de 18 especímenes de cabezas sin fijar de individuos adultas y se documentó la ubicación del RT y su número de ramos. La relación jerárquica entre el ramo temporal y el tejido blando en esta región se observó en 64 cortes plastinados o P45. 1º El RT cruza el AC como tipo I (21,8 %), tipo II (50,0 %) y tipo III (28,1 %). 2º A nivel del margen superior del AC, la distancia promedio entre el tronco anterior de RT y la parte anterior de la aurícula fue de 36,36±6,56 mm, para el tronco posterior fue de 25,59±5,29 mm. A nivel del margen inferior del AC, la distancia promedio entre el tronco anterior del RT y la parte anterior de la aurícula era de 25,77±6,19 mm, para el tronco posterior era de 19,16±4,71 mm. 3º La longitud media de RT fue de 62,06±5,36 mm. EL RT cruzaba el margen inferior del AC a una distancia media de 14,67±6,45 mm. El RT cruzaba el margen superior del AC a una distancia media de 9,08±4,54 mm. 4º Anivel del AC, el RT pasaba por la superficie del pericráneo mientras se encuentra por debajo del SMAS. El RT cruza oblicuamente el tercio medio del margen superior del AC y la unión del tercio medio y el tercio posterior del margen inferior del AC por debajo del SMAS, más allá del periostio. Se sugiere que esta área debe evitarse en la operación clínica para evitar la lesión de la RT.

Differentially Expressed Genes Induced by Erythropoietin Receptor Overexpression in Rat Mammary Adenocarcinoma RAMA 37-28 Cells.

The erythropoietin receptor (EPOR) is a transmembrane type I receptor with an essential role in the proliferation and differentiation of erythroid progenitors. Besides its function during erythropoiesis, EPOR is expressed and has protective effect in various non-hematopoietic tissues, including tumors. Currently, the advantageous aspect of EPOR related to different cellular events is still under scientific investigation. Besides its well-known effect on cell proliferation, apoptosis and differentiation, our integrative functional study revealed its possible associations with metabolic processes, transport of small molecules, signal transduction and tumorigenesis. Comparative transcriptome analysis (RNA-seq) identified 233 differentially expressed genes (DEGs) in EPOR overexpressed RAMA 37-28 cells compared to parental RAMA 37 cells, whereas 145 genes were downregulated and 88 upregulated. Of these, for example, GPC4, RAP2C, STK26, ZFP955A, KIT, GAS6, PTPRF and CXCR4 were downregulated and CDH13, NR0B1, OCM2, GPM6B, TM7SF3, PARVB, VEGFD and STAT5A were upregulated. Surprisingly, two ephrin receptors, EPHA4 and EPHB3, and EFNB1 ligand were found to be upregulated as well. Our study is the first demonstrating robust differentially expressed genes evoked by simple EPOR overexpression without the addition of erythropoietin ligand in a manner which remains to be elucidated.

Efectos del tratamiento médico guiado en pacientes con miocardiopatía inducida por bloqueo de rama izquierda / Effects of guideline-directed medical therapy in patients with left bundle branch block-induced cardiomyopathy

Introducción y objetivos La miocardiopatía inducida por el bloqueo de rama izquierda (BRI) se produce en pacientes con BRI de larga duración. Es característico que muestren hiperrespuesta a las terapias de resincronización cardiaca (TRC). Sin embargo, existe poca información sobre su respuesta al tratamiento médico. El objetivo de este estudio es evaluar el cambio en la fracción de eyección del ventrículo izquierdo (FEVI) después de un periodo de 3 meses tras la dosificación del tratamiento médico recomendado por la guía de insuficiencia cardiaca. Métodos Se trata de un análisis retrospectivo, en el que se incluyó a todos los pacientes valorados en la unidad de insuficiencia cardiaca de un hospital universitario español entre 2020 y 2021, que presentaban disfunción ventricular de novo (FEVI <40%) y tenían antecedentes de BRI de larga evolución sin otras posibles causas de miocardiopatía. Resultados Se analizó a un total de 1.497 pacientes, de los que resultaron elegibles 21. El tiempo medio desde el primer diagnóstico de BRI a la primera consulta fue de 4,05±4,1 años. La FEVI media desde la primera consulta hasta el final de la dosificación mejoró del 29,5±5,7% al 32,7±8,6% (p=0,172); ninguno recuperó la función ventricular al final del seguimiento. La clase funcional de la New York Heart Association mejoró de 1,91±0,46 a 1,81±0,53 (p=0,542). Tras el implante del dispositivo de TRC en 8 pacientes, la FEVI mejoró un 18,1±6,4% (p=0,003). Conclusiones El tratamiento médico recomendado por la guía parece ser ineficaz para mejorar la FEVI y la clase funcional en pacientes con insuficiencia cardiaca de novo y miocardiopatía inducida por BRI. Basándose en la respuesta positiva a la TRC en la mejora de la FEVI, el implante temprano de TRC podría ser una estrategia razonable para estos pacientes (AU)

Introduction and objectives Left bundle branch block (LBBB)-induced cardiomyopathy occurs in patients with long-standing LBBB. These patients characteristically exhibit hyperresponsiveness to cardiac resynchronization therapies (CRT). However, there is scarce information on their response to medical treatment. The aim of this study was to assess the change in left ventricular ejection fraction (LVEF) after a 3-month period following titration of guideline-directed medical therapy for heart failure. Methods This retrospective analysis included all patients assessed in the heart failure unit of a Spanish University Hospital between 2020 and 2021, who presented with de novo ventricular dysfunction (LVEF <40%) and had a history of long-standing LBBB with no other possible causes of cardiomyopathy. Results A total of 1497 patients were analyzed, of which 21 were finally eligible. Mean time from first diagnosis of LBBB to first consultation was 4.05± 4.1 years. Mean LVEF from first consultation to end of titration improved from 29.5±5.7% to 32.7±8.6% (P = .172), but none had recovered ventricular function at the end of follow-up. New York Heart Association functional class improved from 1.91±0.46 to 1.81±0.53 (P=.542). After CRT device implantation in 8 patients, LVEF improved by 18.1±6.4% (P=.003). Conclusions Guideline-directed medical therapy seems to be ineffective in improving LVEF and functional class in patients with de novo heart failure and LBBB-induced cardiomyopathy. Based on a positive response to CRT on LVEF improvement, early CRT implantation could be a reasonable strategy for these patients (AU)

Mejoría clínica, hemodinámica y de marcadores bioquímicos tras estimulación ventricular desde el área de la rama izquierda / Clinical, hemodynamic and biochemical improvement related to left bundle branch area pacing

Resumen Introducción: La estimulación ventricular derecha puede provocar insuficiencia cardiaca y disfunción ventricular. La estimulación en el área de la rama izquierda (ERI) permite capturar el sistema His-Purkinje. La ERI se ha estudiado en la estimulación ventricular y en la terapia de resincronización cardiaca. La evolución de los péptidos natriuréticos (NT-proBNP) asociada a la ERI no ha sido estudiada hasta el momento. Métodos: Se incluyeron pacientes consecutivos remitidos para implante de marcapasos o terapia de resincronización cardiaca. El implante del electrodo de ERI se realizó siguiendo la técnica descrita por Huang et al. Los pacientes eran sometidos a ecocardiograma y determinación de NT-proBNP antes y cuatro semanas después del procedimiento. Resultados: Se analizaron 50 pacientes con implante exitoso y seguimiento completo. No hubo diferencias significativas entre los umbrales medidos durante el procedimiento y los obtenidos al cabo de 12 semanas. La ERI logró una reducción significativa de la anchura del complejo QRS (148 ± 21 vs. 107 ± 11 ms; p = 0.029). La ERI logró una reducción significativa de la clasificación funcional en el conjunto de la muestra y una reducción significativa de NT-proBNP (2,888.2 ± 510 vs. 1,181 ± 130 pg/ml; p = 0.04). En pacientes con fracción de eyección del ventrículo izquierdo (FEVI) < 50% y asincronía se logró un incremento significativo de la FEVI con la ERI (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). Conclusiones: La ERI es factible en la mayoría de pacientes y se asocia con una reducción de la duración del complejo QRS. La ERI no condiciona un efecto deletéreo sobre la FEVI a corto-medio plazo; además, en aquellos pacientes con FEVI deprimida y asincronía ventricular permite incrementar la FEVI.

Abstract Background: Right ventricular pacing is associated with risk of heart failure and left ventricular dysfunction. Left bundle branch area pacing (LBBP) has emerged as an alternative method for delivering physiological pacing. The effect of LBBP on N-terminal pro-brain natriuretic peptide (NT-proBNP) has not been investigated. Method: Finally, 50 patients referred for pacemaker implantation were included. LBBP was performed as described previously by Huang et al. Transthoracic echocardiogram and NT-proBNP were performed before and four weeks after the procedure. Results: 50 patients were analyzed. There were not differences between ventricular thresholds during the procedure and 3 months later, LBBP significantly reduced QRS complex duration (148 ± 21 vs. 107 ± 11 ms; p = 0.029). LBBP significantly improved NYHA functional class and reduced NT-proBNP concentration (2888.2 ± 510 vs. 1181 ± 130 pg/ml; p = 0.04). In patients showing left ventricular ejection fraction (LVEF) < 50% and ventricular desynchrony LBBP showed a significant LVEF increase (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). Conclusions: LBBP was feasible and safe in most of patients. LBBP was associated with reduction in QRS width and with increase in LVEF in patients with ventricular desynchrony, while in patients with normal LVEF it remained unchanged during follow-up.

Genome-wide analysis of genes involved in efflux function and regulation within Escherichia coli and Salmonella enterica serovar Typhimurium.

The incidence of multidrug-resistant bacteria is increasing globally, with efflux pumps being a fundamental platform limiting drug access and synergizing with other mechanisms of resistance. Increased expression of efflux pumps is a key feature of most cells that are resistant to multiple antibiotics. Whilst expression of efflux genes can confer benefits, production of complex efflux systems is energetically costly and the expression of efflux is highly regulated, with cells balancing benefits against costs. This study used TraDIS-Xpress, a genome-wide transposon mutagenesis technology, to identify genes in Escherichia coli and Salmonella Typhimurium involved in drug efflux and its regulation. We exposed mutant libraries to the canonical efflux substrate acriflavine in the presence and absence of the efflux inhibitor phenylalanine-arginine ß-naphthylamide. Comparisons between conditions identified efflux-specific and drug-specific responses. Known efflux-associated genes were easily identified, including acrAB, tolC, marRA, ramRA and soxRS, confirming the specificity of the response. Further genes encoding cell envelope maintenance enzymes and products involved with stringent response activation, DNA housekeeping, respiration and glutathione biosynthesis were also identified as affecting efflux activity in both species. This demonstrates the deep relationship between efflux regulation and other cellular regulatory networks. We identified a conserved set of pathways crucial for efflux activity in these experimental conditions, which expands the list of genes known to impact on efflux efficacy. Responses in both species were similar and we propose that these common results represent a core set of genes likely to be relevant to efflux control across the Enterobacteriaceae.

Clinical, hemodynamic and biochemical improvement related to left bundle branch area pacing.

BACKGROUND: Right ventricular pacing is associated with risk of heart failure and left ventricular dysfunction. Left bundle branch area pacing (LBBP) has emerged as an alternative method for delivering physiological pacing. The effect of LBBP on N-terminal pro-brain natriuretic peptide (NT-proBNP) has not been investigated. METHOD: Finally, 50 patients referred for pacemaker implantation were included. LBBP was performed as described previously by Huang et al. Transthoracic echocardiogram and NT-proBNP were performed before and four weeks after the procedure. RESULTS: 50 patients were analyzed. There were not differences between ventricular thresholds during the procedure and 3 months later, LBBP significantly reduced QRS complex duration (148 ± 21 vs. 107 ± 11 ms; p = 0.029). LBBP significantly improved NYHA functional class and reduced NT-proBNP concentration (2888.2 ± 510 vs. 1181 ± 130 pg/ml; p = 0.04). In patients showing left ventricular ejection fraction (LVEF) < 50% and ventricular desynchrony LBBP showed a significant LVEF increase (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). CONCLUSIONS: LBBP was feasible and safe in most of patients. LBBP was associated with reduction in QRS width and with increase in LVEF in patients with ventricular desynchrony, while in patients with normal LVEF it remained unchanged during follow-up.

INTRODUCCIÓN: La estimulación ventricular derecha puede provocar insuficiencia cardiaca y disfunción ventricular. La estimulación en el área de la rama izquierda (ERI) permite capturar el sistema His-Purkinje. La ERI se ha estudiado en la estimulación ventricular y en la terapia de resincronización cardiaca. La evolución de los péptidos natriuréticos (NT-proBNP) asociada a la ERI no ha sido estudiada hasta el momento. MÉTODOS: Se incluyeron pacientes consecutivos remitidos para implante de marcapasos o terapia de resincronización cardiaca. El implante del electrodo de ERI se realizó siguiendo la técnica descrita por Huang et al. Los pacientes eran sometidos a ecocardiograma y determinación de NT-proBNP antes y cuatro semanas después del procedimiento. RESULTADOS: Se analizaron 50 pacientes con implante exitoso y seguimiento completo. No hubo diferencias significativas entre los umbrales medidos durante el procedimiento y los obtenidos al cabo de 12 semanas. La ERI logró una reducción significativa de la anchura del complejo QRS (148 ± 21 vs. 107 ± 11 ms; p = 0.029). La ERI logró una reducción significativa de la clasificación funcional en el conjunto de la muestra y una reducción significativa de NT-proBNP (2,888.2 ± 510 vs. 1,181 ± 130 pg/ml; p = 0.04). En pacientes con fracción de eyección del ventrículo izquierdo (FEVI) < 50% y asincronía se logró un incremento significativo de la FEVI con la ERI (40.2 ± 7 vs. 55.2 ± 7%; p < 0.001). CONCLUSIONES: La ERI es factible en la mayoría de pacientes y se asocia con una reducción de la duración del complejo QRS. La ERI no condiciona un efecto deletéreo sobre la FEVI a corto-medio plazo; además, en aquellos pacientes con FEVI deprimida y asincronía ventricular permite incrementar la FEVI.

Arrhythmic risk in single or recurrent episodes of unexplained syncope with complete bundle branch block.

INTRODUCTION AND OBJECTIVES: Patients with a single syncopal episode (SSE) and complete bundle branch block (cBBB) are frequently managed more conservatively than patients with recurrent episodes (RSE). The objective of this study was to analyze if there are differences between patients with single or recurrent unexplained syncope and cBBB in arrhythmic risk, the diagnostic yield of tests, and clinical outcomes. METHODS: Cohort study of consecutive patients with unexplained syncope and cBBB with a median follow-up time of 3 years. The patients were evaluated via a stepwise workup protocol based on electrophysiological study (EPS) and long-term follow-up with an implantable cardiac monitor. RESULTS: Of the 503 patients included in the study, 238 (47.3%) had had only 1 syncopal episode. The risk of an arrhythmic syncope was similar in both groups (58.8% in SSE vs 57.0% in RSE; P=.68), also after adjustment for possible confounding variables (HR, 1.06; 95%CI, 0.81-1.38; P=.674). No significant differences between the groups were found in the EPS results and implantable cardiac monitor diagnostic yield. A total of 141 (59.2%) patients with SSE and 154 (58.1%) patients with RSE required cardiac device implantation (P=.797). After appropriate treatment, 35 (7%) patients had recurrence of syncope. The recurrence rate and mortality were also similar in both groups. CONCLUSIONS: Patients with cBBB and unexplained syncope are at high risk of an arrhythmic etiology, even after the first syncopal episode. Patients with SSE and RSE have a similar arrhythmic risk and similar outcomes, and therefore there is no clinical justification for not managing them in the same manner.

Effects of guideline-directed medical therapy in patients with left bundle branch block-induced cardiomyopathy.

INTRODUCTION AND OBJECTIVES: Left bundle branch block (LBBB)-induced cardiomyopathy occurs in patients with long-standing LBBB. These patients characteristically exhibit hyperresponsiveness to cardiac resynchronization therapies (CRT). However, there is scarce information on their response to medical treatment. The aim of this study was to assess the change in left ventricular ejection fraction (LVEF) after a 3-month period following titration of guideline-directed medical therapy for heart failure. METHODS: This retrospective analysis included all patients assessed in the heart failure unit of a Spanish University Hospital between 2020 and 2021, who presented with de novo ventricular dysfunction (LVEF <40%) and had a history of long-standing LBBB with no other possible causes of cardiomyopathy. RESULTS: A total of 1497 patients were analyzed, of which 21 were finally eligible. Mean time from first diagnosis of LBBB to first consultation was 4.05± 4.1 years. Mean LVEF from first consultation to end of titration improved from 29.5±5.7% to 32.7±8.6% (P = .172), but none had recovered ventricular function at the end of follow-up. New York Heart Association functional class improved from 1.91±0.46 to 1.81±0.53 (P=.542). After CRT device implantation in 8 patients, LVEF improved by 18.1±6.4% (P=.003). CONCLUSIONS: Guideline-directed medical therapy seems to be ineffective in improving LVEF and functional class in patients with de novo heart failure and LBBB-induced cardiomyopathy. Based on a positive response to CRT on LVEF improvement, early CRT implantation could be a reasonable strategy for these patients.

Immunogenicity and antigenicity of a conserved fragment of the rhoptry-associated membrane antigen of Plasmodium vivax.

BACKGROUND: Plasmodium vivax rhoptry-associated membrane antigen (RAMA) is a glycophosphatidylinositol-anchored membrane protein currently under consideration as a malaria vaccine candidate. Immunoglobulin G (IgG) antibodies induced by P. vivax RAMA (PvRAMA) have been proved to persist over 12 months in the sera of people infected with P. vivax. It has also been shown that through stimulation of peripheral blood mononuclear cells with PvRAMA in vitro, the antigen can induce CD4+ T cells to produce interleukin-10. However, the genetic diversity of the RAMA gene in isolates of P. vivax (pvrama) and the immunogenicity of PvRAMA in animals remain unclear. METHODS: Genomic DNA was extracted from blood samples (n = 25) of patients in Jiangsu Province, China with imported infections of P. vivax from endemic countries in South and Southeast Asia. The extract genomic DNA was used as templates to amplify the P. vivax rama gene (pvrama) by PCR, and the PCR products were then sequenced and analyzed by the DnaSP, MEGA, and GeneDoc software packages. Recombinant PvRAMA (rPvRAMA) protein was expressed and purified, and then used to immunize mice. Levels of total IgG and different IgG subclasses of rPvRAMA-immunized mice were evaluated by enzyme-linked immunosorbent assay. Also, spleen cells of rPvRAMA-immunized mice were stimulated with rPvRAMA in vitro and levels of T cells were measured by flow cytometry. RESULTS: The average pairwise nucleotide diversity (π) of the pvrama gene was 0.00190, and the haplotype diversity (Hd) was 0.982. The C-terminal of PvRAMA showed lower haplotype diversity compared to the N-terminal and was completely conserved at amino acid sites related to erythrocyte binding. To further characterize immunogenicity of the C-terminal of PvRAMA, mice were immunized with rPvRAMA antigen. The rPvRAMA protein induced antibody responses, with the end-point titer ranging from 1:10,000 to 1:5,120,000. IgG1 was the predominant IgG subclass in rPvRAMA-immunized mice, followed by IgG2b. In addition, levels of CD4+ and CD8+ T cells in the rPvRAMA-stimulated group were significantly higher than those in the phosphate-buffered saline-stimulated group (normal control group). CONCLUSIONS: The high conservation at specific amino acid sites and the high immunogenicity of the C-terminal of PvRAMA indicate the presence of conserved epitopes able to generate broadly reactive humoral and cellular immune responses. These findings support the potential of PvRAMA to serve as a vaccine candidate against P. vivax infection.

Bacterial distribution in the Equatorial Indian Ocean using Amplicon sequencing of V3-V4 rDNA hypervariable region data.

The Equatorial Indian Ocean (EIO) is a complex system strongly influenced by Indian Monsoon. During a RAMA (Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction) mooring maintenance expedition during the Southwest monsoon (August-September 2016) onboard ORV Sagar Kanya, seawater samples from the surface, deep chlorophyll maxima (DCM) and 200m were collected for bacterioplankton community structure. Herein we document our amplicon data of the bacterial community at 4 stations (4.01°S, 1.60°S, 0.36°N and 1.78°N) along the 67°00' E transect. The samples were subjected to next-generation sequencing (NGS), followed by processing with Mothur v 1.48.0, and the taxonomic classification prepared with Silva 138.1nr reference database. Our data indicates Alphaproteobacteria (48 %) and Cyanobacteria (33 %) dominance in the surface and DCM samples.

High-level ertapenem resistance in Klebsiella pneumoniae is due to RamA downregulation of ompK35 through micF.

An ertapenem-resistant Klebsiella pneumoniae clinical isolate (KP20) without carbapenemase and negative for the efflux pump inhibition test was resistant to ertapenem at a high level [minimum inhibitory concentration (MIC) = 64 mg/L] but susceptible to meropenem and imipenem. Second-generation sequencing was performed and a termination mutation was found in ramR. Complementation of ramR in KP20 reduced the ertapenem MIC by 128 times (from 64 mg/L to 0.5 mg/L). Overexpression of ramA and loss of OmpK35 were discovered in strain KP20 by quantitative reverse transcription PCR (RT-qPCR) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Furthermore, ramA deletion in strain KP20 resulted in a 128-fold decrease in the MIC of ertapenem (from 64 mg/L to 0.5 mg/L), and expression of OmpK35 was observed in KP20ΔramA by SDS-PAGE. Complementation of ramA in KP20ΔramA led to a 45.45-fold downregulation of ompK35. Complementation of ompK35 in KP20 could restore susceptibility to ertapenem (MIC reduced from 64 mg/L to 0.25 mg/L). Furthermore, results of the electrophoretic mobility shift assay showed that RamA could bind to the promoter of micF. These results showed that the termination mutation in ramR resulted in overexpression of ramA causing loss of OmpK35 expression through upregulation of micF, revealing the mechanism of ertapenem resistance only in K. pneumoniae.

Factores asociados al bloqueo de rama derecha en adultos mayores / Factors associated with right bundle branch block in older adults

RESUMEN Introducción: Existe poca literatura sobre la asociación entre el bloqueo de rama derecha y factores de riesgo como la hipertensión y la diabetes en pacientes de Latinoamérica y Perú. Objetivo: Determinar los factores asociados al bloqueo de rama derecha en adultos mayores. Métodos: Estudio transversal que incluyó 376 pacientes adultos mayores atendidos en el Hospital Almanzor Aguinaga Asenjo, Lambayeque-Perú. La variable dependiente fue la presencia de bloqueo de rama derecha y las variables independientes fueron edad, sexo, antecedente de hipertensión arterial y diabetes. Se estimaron razones de prevalencia e intervalos de confianza al 95 %. Resultados: De 376 pacientes, la mayoría eran varones (55,9 %), la edad media fue de 75,6 años, el 11,4 % tuvo antecedente de hipertensión y el 9 % era diabético. El 41 % tuvo diagnóstico de bloqueo de rama derecha. En la regresión múltiple; el sexo femenino (RP=1,53, IC 95 %: 1,21 - 1,95), antecedente de hipertensión (RP=1,55; IC 95 %: 1,21 - 2,00) y diabetes mellitus (RP=1,49, IC 95 %: 1,12 - 2,00) se asociaron de forma positiva a presentar bloqueo de rama derecha. El modelo anidado seleccionó las variables: sexo femenino (RP=1,54, IC 95 %: 1,21 - 1,96) y antecedente de hipertensión arterial (RP=1,61, IC 95 %: 1,25 - 2,08). Conclusión: El sexo femenino, antecedente de hipertensión arterial y de diabetes mellitus se asocian positivamente a presentar bloqueo de rama derecha.

ABSTRACT Introduction: There is little literature on the association between right bundle branch block and risk factors such as hypertension and diabetes in patients in Latin America and Peru. Objective: To determine the factors associated with right bundle branch block in older adults. Methods: Analytical cross-sectional study completed by 376 elderly patients treated at Almanzor Aguinaga Asenjo Hospital, Lambayeque-Peru. The dependent variable was the presence of right bundle branch block, and the independent variables were age, sex, history of hypertension, and diabetes. Prevalence ratios and 95 % confidence intervals were estimated. Results: Of 376 patients, the majority were male (55,9 %), the mean age was 75,6 years, 11,4 % had a history of hypertension and 9 % were diabetic; 41 % had a diagnosis of right bundle branch block. In simple regression, the frequency of right bundle branch block was 56 % (PR= 1,56; 95 % CI: 1,22-1,99), 65 % (PR=1,65; 95 % CI: 1,26 - 2,15) and 59 % (PR= 1,59; CI 95 %: 1,18 - 2,14) higher in women, hypertensive and diabetics; respectively. In the multiple regression; female sex (PR= 1,53; 95 % CI: 1,21 - 1,95), history of hypertension (PR= 1,55; 95 % CI: 1,21 - 2,00) and diabetes mellitus (PR= 1,49; 95 % CI: 1,12 - 2,00) were positively associated with right bundle branch block. The nested model selected the variables: female sex (PR= 1,54; 95 % CI: 1,21 - 1,96) and history of arterial hypertension (PR= 1,61; 95 % CI: 1,25 - 2,08). Conclusion: Female sex, history of arterial hypertension and diabetes mellitus were positively associated with presenting right bundle branch block in older adults.

Evaluación de las relaciones entre la rama palmar profunda de la arteria ulnar y el ramo profundo del nervio ulnar en la región palmar / Evaluation of the relationship between the deep palmar branch of ulnar artery and the deep branch of the ulnar nerve in the palmar region

RESUMEN: Nos motivó esta presentación los hallazgos observados en la sala de disección sobre las relaciones de la rama palmar profunda de la arteria ulnar y el ramo profundo del nervio ulnar, las diferentes disposiciones de esta rama, el cruzamiento, cuando existe, entre ambos elementos y las pocas referencias sobre el tema, todo con miras a favorecer el abordaje profundo de la palma de la mano y contribuir al conocimiento del área en donde se practican las neurotomías del ramo profundo del nervio ulnar y/ o sus ramas.

SUMMARY: We are motivated by the findings observed in the dissection room on the relationship between the deep palmar branch of ulnar artery and the deep branch of ulnar nerve, the different dispositions of this branch, the crossing, when it exists, between both elements and the few references on the subject, all with a view to favoring the deep approach to the palm and contributing to the knowledge of the area where neurotomies of the deep branch of ulnar nerve and/or its branches are performed.

Prevalencia e impacto en el pronóstico del bloqueo de rama derecha en pacientes con insuficiencia cardíaca aguda: hallazgos del registro RICA / Prevalence and impact on prognosis of right-bundle branch block in patients with acute heart failure: Findings from the RICA registry

Objetivos: Determinar la prevalencia, las características y el impacto en el pronóstico del bloqueo de rama derecha (BRD) en una cohorte de pacientes con insuficiencia cardíaca aguda (ICA). Métodos: Analizamos prospectivamente 3.638 pacientes con ICA incluidos en el Registro Nacional de Insuficiencia Cardíaca de la Sociedad Española de Medicina Interna (RICA). Analizamos de forma independiente la relación entre las características basales y clínicas y la presencia de BRD, y el impacto potencial del BRD en la mortalidad por todas las causas a un año y el evento combinado de hospitalización o muerte a 90 días después del alta. Resultados: La prevalencia de BRD fue del 10,9%. Los pacientes con BRD eran de edad más avanzada, con mayor proporción de sexo masculino y comorbilidades pulmonares, valores más altos de fracción de eyección del ventrículo izquierdo y peor estado funcional. No hubo diferencias en riesgo para los pacientes con BRD, con un cociente de riesgo ajustado (intervalo de confianza del 95%) para la mortalidad a un año de 1,05 (0,83-1,32) y para el evento combinado a 90 días después del alta de 0,97 (0,74-1,25). Estos resultados fueron consistentes en los análisis de sensibilidad. Conclusiones: Pocos pacientes con ICA presentan BRD, que se asocia consistentemente con la edad avanzada, el sexo masculino, las comorbilidades pulmonares, la fracción de eyección del ventrículo izquierdo preservada y el peor estado funcional. Sin embargo, después de tener en cuenta estos factores, el BRD en pacientes con ICA no se asocia a peores resultados (AU)

Objectives: This work aims to determine the prevalence, characteristics, and impact on prognosis of right bundle branch block (RBBB) in a cohort of acute heart failure (AHF) patients. Methods: We prospectively analyzed 3,638 AHF patients included in the RICA registry (National Heart Failure Registry of the Spanish Internal Medicine Society). We independently analyzed the relationship between baseline and clinical characteristics and the presence of RBBB as well as the potential impact of RBBB on 1-year all-cause mortality and a composite endpoint of 90-day post-discharge hospitalization or death. Results: The prevalence of RBBB was 10.9%. Patients with RBBB were older, a higher proportion were male, had more pulmonary comorbidities, had higher left ventricular ejection fraction values, and had worse functional status. There were no differences in risk for patients with RBBB, with an adjusted hazard ratio (95% confidence interval) for 1-year mortality of 1.05 (0.83-1.32), and for the composite endpoint of 90-day post-discharge hospitalization or death of 0.97 (0.74-1.25). These results were consistent on the sensitivity analyses. Conclusions: Few patients with AHF present with RBBB, which is consistently associated with advanced age, male sex, pulmonary comorbidities, preserved left ventricular ejection fraction, and worse functional status. Nonetheless, after considering these factors, RBBB in AHF patients is not associated with worse outcomes (AU)