The 4q25 variant rs13143308T links risk of atrial fibrillation to defective calcium homoeostasis

Aims: Single nucleotide polymorphisms on chromosome 4q25 have been associated with risk of atrial fibrillation (AF) but the exiguous knowledge of the mechanistic links between these risk variants and underlying electrophysiological alterations hampers their clinical utility. Here, we tested the hypothesis that 4q25 risk variants cause alterations in the intracellular calcium homoeostasis that predispose to spontaneous electrical activity. Methods and results: Western blotting, confocal calcium imaging, and patch-clamp techniques were used to identify mechanisms linking the 4q25 risk variants rs2200733T and rs13143308T to defects in the calcium homoeostasis in human atrial myocytes. Our findings revealed that the rs13143308T variant was more frequent in patients with AF and that myocytes from carriers of this variant had a significantly higher density of calcium sparks (14.1¿±¿4.5 vs. 3.1¿±¿1.3 events/min, P¿=¿0.02), frequency of transient inward currents (ITI) (1.33¿±¿0.24 vs. 0.26¿±¿0.09 events/min, P¿<¿0.001) and incidence of spontaneous membrane depolarizations (1.22¿±¿0.26 vs. 0.56¿±¿0.17 events/min, P¿=¿0.001) than myocytes from patients with the normal rs13143308G variant. These alterations were linked to higher sarcoplasmic reticulum calcium loading (10.2¿±¿1.4 vs. 7.3¿±¿0.5¿amol/pF, P¿=¿0.01), SERCA2 expression (1.37¿±¿0.13 fold, P¿=¿0.03), and RyR2 phosphorylation at ser2808 (0.67¿±¿0.08 vs. 0.47¿±¿0.03, P¿=¿0.01) but not at ser2814 (0.28¿±¿0.14 vs. 0.31¿±¿0.14, P¿=¿0.61) in patients carrying the rs13143308T risk variant. Furthermore, the presence of a risk variant or AF independently increased the ITI frequency and the increase in the ITI frequency observed in carriers of the risk variants was exacerbated in those with AF. By contrast, the presence of a risk variant did not affect the amplitude or properties of the L-type calcium current in patients with or without AF. Conclusions: Here, we identify the 4q25 variant rs13143308T as a genetic risk marker for AF, specifically associated with excessive calcium release and spontaneous electrical activity linked to increased SERCA2 expression and RyR2 phosphorylation.Peer ReviewedPostprint (author's final draft

Experiencias de cuidado paliativo en contexto de pandemia : Estudio a realizarse con los enfermeros y pacientes de la Casa de la Bondad, Provincia de Córdoba, durante el primer cuatrimestre del 2023

El 19 de marzo de 2020, el Poder Ejecutivo Nacional dictó el DNU N° 297/2020 que dispuso el aislamiento social, preventivo y obligatorio (ASPO) para todas las personas que habitaran en el país o se encontraran en él en forma temporaria al momento de su dictado, con el objetivo de proteger la salud pública, obligación inalienable del Estado nacional. Como es de esperarse en una circunstancia de este tipo, los hospitales, y las instituciones de salud en general, están tratando a decenas de miles de enfermos graves, muchos de los cuales necesitan soporte vital sin que sus familias los puedan acompañar. Para los pacientes y las familias que tienen que estar separados porque el virus es tan contagioso, esto ha sido especialmente difícil. Ante tal situación, es necesario profundizar con respecto a la categoría cuidados paliativos, entendidos como un enfoque que busca mejorar la calidad de vida de los pacientes y sus familias a partir del afrontamiento de problemas que se asocian de alguna u otra forma con una condición potencialmente mortal, por medio de prevenir y alivianar el sufrir a partir de identificar lo antes posible la enfermedad, evaluarla y tratar el dolor y todas aquellas dolencias físicas, psicosociales y espirituales surgidas de ella (Organización Mundial de la Salud, 2004). En razón de ello, el objetivo general de esta investigación se basa en describir las experiencias de cuidado paliativo de los/as enfermeros/as y de los pacientes de la Casa de la Bondad (Córdoba), ante la circunstancia de pandemia a causa del covid-19, durante el primer cuatrimestre del 2023, en pos de contribuir a la revisión, actualización y construcción de conocimiento científico de la enfermería mediante la reflexión activa, específicamente en relación al cuidado de personas con tratamiento paliativo en circunstancias globales de vulnerabilidad, como así también propiciar un cuidado enfermero desde una mirada humanística y singular. Asimismo, es preciso destacar que es un estudio de tipo cualitativo, más precisamente fenomenológico, que se basará en el método inductivo a partir del cual mediante la observación e interpretación de los datos se buscarán explicar desde las perspectivas teóricas de un fenómeno. En relación a esto, la población en estudio estará conformada por el total de sujetos pertenecientes a la Casa de la Bondad de Córdoba, y la muestra será por saturación teórica. Por otro lado, la fuente será primaria, y la técnica elegida para recoger información será la entrevista en su variante de entrevista abierta. En relación con el aspecto estructural de este trabajo, ha de establecerse que su desarrollo consta de dos capítulos generales: el primero gira en torno al tema de investigación, en tanto allí se introduce y justifica su razón, así como también se define la variable y el marco conceptual que la enmarca. En segundo lugar, se encuentra el apartado en el que se delimitan los aspectos metodológicos en tanto tipo de estudio, variable y dimensiones, población, muestra y técnica de recolección de datos. Además, se adjuntan el Cronograma y el Presupuesto de la investigación, como así también se incluyen anexos como las notas de ingreso al campo, el consentimiento informado, el instrumento de recolección de información y la tabla matriz. En razón de ello, en el presente trabajo de investigación se procederán a analizar, a partir de un lineamiento teórico que respalde las categorizaciones utilizadas y una metodología cualitativa que presenta a la entrevista como herramienta de recolección de datos, aquellas experiencias de cuidado de enfermeros y pacientes pertenecientes a La Casa de la Bondad, Hospice de cuidados paliativos localizado en la ciudad de Córdoba Capital, y dependientes de la fundación Manos Abiertas, en pos de contribuir a la revisión, actualización y construcción de conocimientos científicos de la enfermería, mediante la reflexión en la acción, específicamente en relación al cuidado de las personas con tratamiento paliativo en tiempo de pandemia.Fil: Corilla, Egoavil Elizabeth. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Enfermería; Argentina.Fil: Vargas, Carmen María de los Ángeles. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Enfermería; Argentina.Fil: Tarifa, Nancy Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Enfermería; Argentina

Increased density of endogenous adenosine A2A receptors in atrial fibrillation: from cellular and porcine models to human patients

Adenosine, an endogenous nucleoside, plays a critical role in maintaining homeostasis during stressful situations, such as energy deprivation or cellular damage. Therefore, extracellular adenosine is generated locally in tissues under conditions such as hypoxia, ischemia, or inflammation. In fact, plasma levels of adenosine in patients with atrial fibrillation (AF) are elevated, which also correlates with an increased density of adenosine A2A receptors (A2ARs) both in the right atrium and in peripheral blood mononuclear cells (PBMCs). The complexity of adenosine-mediated effects in health and disease requires simple and reproducible experimental models of AF. Here, we generate two AF models, namely the cardiomyocyte cell line HL-1 submitted to Anemonia toxin II (ATX-II) and a large animal model of AF, the right atrium tachypaced pig (A-TP). We evaluated the density of endogenous A2AR in those AF models. Treatment of HL-1 cells with ATX-II reduced cell viability, while the density of A2AR increased significantly, as previously observed in cardiomyocytes with AF. Next, we generated the animal model of AF based on tachypacing pigs. In particular, the density of the key calcium regulatory protein calsequestrin-2 was reduced in A-TP animals, which is consistent with the atrial remodelling shown in humans suffering from AF. Likewise, the density of A2AR in the atrium of the AF pig model increased significantly, as also shown in the biopsies of the right atrium of subjects with AF. Overall, our findings revealed that these two experimental models of AF mimicked the alterations in A2AR density observed in patients with AF, making them attractive models for studying the adenosinergic system in AF

Pitx2c deficiency confers cellular electrophysiological hallmarks of atrial fibrillation to isolated atrial myocytes

Aims Atrial fibrillation (AF) has been associated with altered expression of the transcription factor Pitx2c and a high incidence of calcium release-induced afterdepolarizations. However, the relationship between Pitx2c expression and defective calcium homeostasis remains unclear and we here aimed to determine how Pitx2c expression affects calcium release from the sarcoplasmic reticulum (SR) and its impact on electrical activity in isolated atrial myocytes. Methods To address this issue, we applied confocal calcium imaging and patch-clamp techniques to atrial myocytes isolated from a mouse model with conditional atrial-specific deletion of Pitx2c. Results Our findings demonstrate that heterozygous deletion of Pitx2c doubles the calcium spark frequency, increases the frequency of sparks/site 1.5-fold, the calcium spark decay constant from 36 to 42 ms and the wave frequency from none to 3.2 min-1. Additionally, the cell capacitance increased by 30% and both the SR calcium load and the transient inward current (ITI) frequency were doubled. Furthermore, the fraction of cells with spontaneous action potentials increased from none to 44%. These effects of Pitx2c deficiency were comparable in right and left atrial myocytes, and homozygous deletion of Pitx2c did not induce any further effects on sparks, SR calcium load, ITI frequency or spontaneous action potentials. Conclusion Our findings demonstrate that heterozygous Pitx2c deletion induces defects in calcium homeostasis and electrical activity that mimic derangements observed in right atrial myocytes from patients with AF and suggest that Pitx2c deficiency confers cellular electrophysiological hallmarks of AF to isolated atrial myocytes.Peer ReviewedPostprint (published version

Novel PITX2 Homeodomain-Contained Mutations from ATRIAL Fibrillation Patients Deteriorate Calcium Homeostasis

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the human population, with an estimated incidence of 1¿2% in young adults but increasing to more than 10% in 80+ years patients. Pituitary Homeobox 2, Paired Like Homeodomain 2 (PITX2c) loss-of-function in mice revealed that this homeodomain (HD)-containing transcription factor plays a pivotal role in atrial electrophysiology and calcium homeostasis and point to PITX2 as a candidate gene for AF. To address this issue, we recruited 31 AF patients for genetic analyses of both the known risk alleles and PITX2c open reading frame (ORF) re-sequencing. We found two-point mutations in the homedomain of PITX2 and three other variants in the 5¿untranslated region. A 65 years old male patient without 4q25 risk variants but with recurrent AF displayed two distinct HD-mutations, NM_000325.5:c.309G>C (Gln103His) and NM_000325.5:c.370G>A (Glu124Lys), which both resulted in a change within a highly conserved amino acid position. To address the functional impact of the PITX2 HD mutations, we generated plasmid constructs with mutated version of each nucleotide variant (MD4 and MD5, respectively) as well as a dominant negative control construct in which the PITX2 HD was lacking (DN). Functional analyses demonstrated PITX2c MD4 and PITX2c MD5 decreased Nppa-luciferase transactivation by 50% and 40%, respectively, similar to the PITX2c DN (50%), while Shox2 promoter repression was also impaired. Co-transactivation with other cardiac-enriched co-factors, such as Gata4 and Nkx2.5, was similarly impaired, further supporting the pivotal role of these mutations for correct PITX2c function. Furthermore, when expressed in HL1 cardiomyocyte cultures, the PITX2 mutants impaired endogenous expression of calcium regulatory proteins and induced alterations in sarcoplasmic reticulum (SR) calcium accumulation. This favored alternating and irregular calcium transient amplitudes, causing deterioration of the beat-to-beat stability upon elevation of the stimulation frequency. Overall this data demonstrate that these novel PITX2c HD-mutations might be causative of atrial fibrillation in the carrier.This work was supported by grants from The Spanish Ministry of Science Innovation and Universities [SAF2017-88019-C3-1-R] to L.H.-M. V.J.-S. was employed by CIBERCV [RD12/0042/0002] grant. Work was also supported by a PhD scholarship [FPU18/01250] to S.C., and partially funded by grants from Generalitat de Catalunya [SGR2017-1769] and Fundació Marato TV3 [20152030] to L.H.-M., a translational CNIC grant [2009/08] to D.F., R.C. and L.H.-M. and a grant-in-aid from the Junta de Andalucia Regional Council to D.F. and A.A. [CTS-446]

Spatial distribution of calcium sparks determines their ability to induce afterdepolarizations in human atrial myocytes

Analysis of the spatio-temporal distribution of calcium sparks showed a preferential increase in sparks near the sarcolemma in atrial myocytes from patients with atrial fibrillation (AF), linked to higher ryanodine receptor (RyR2) phosphorylation at s2808 and lower calsequestrin-2 levels. Mathematical modeling, incorporating modulation of RyR2 gating, showed that only the observed combinations of RyR2 phosphorylation and calsequestrin-2 levels can account for the spatio-temporal distribution of sparks in patients with and without AF. Furthermore, we demonstrate that preferential calcium release near the sarcolemma is key to a higher incidence and amplitude of afterdepolarizations in atrial myocytes from patients with A

Sevoflurane Sedation Protocol in Children with Cerebral Palsy Undergoing BotulinumToxin-A Injections

Objetivo: Describir nuestra experiencia con un protocolo basado en el uso de sevoflurano para la sedación y analgesia durante la infiltración de Toxina Botulínica tipo A (BoNT-A) en niños con parálisis cerebral (PC), especialmente en términos de seguridad y efectividad. Material y Métodos: Estudio observacional retrospectivo de pacientes con PC a los que se realizó infiltración con BoNT-A bajo sedación con sevoflurano desde noviembre de 2012 hasta diciembre de 2019. Se revisaron las características demográficas, las características clínicas y funcionales, la efectividad de la sedación, los eventos adversos (EA) y la satisfacción del profesional. Resultados: se realizaron 387 sedaciones en 74 pacientes diagnosticados de PC. La sedación efectiva se logró en el 100% de los procedimientos, facilitando la colaboración durante la infiltración y la satisfacción del profesional. Se notificaron EA en el 6,02% de los procedimientos, siendo las más frecuentes las náuseas y los vómitos (3,88%) y la hipoxemia transitoria (2,07%). No se informaron EA graves. No se encontró asociación entre la incidencia de EA y las variables clínicas, funcionales o el riesgo antes de la anestesia. Conclusiones: La sedación con sevoflurano muestra resultados prometedores en términos de seguridad y efectividad para el manejo de la agitación y el dolor durante la infiltración de BoNT-A en nuestra práctica clínica diaria. Además, puede facilitar la infiltración, permitir la exploración bajo sedación e infiltración multinivel con buena tolerancia.Objective: This study aimed to describe our experience with a protocol based on sevoflurane sedation to control pain and agitation during botulinum toxin-A (BoNT-A) infiltration in children with cerebral palsy (CP), especially in terms of safety and efficacy. Material and methods: We conducted a retrospective observational study of patients diagnosed with CP who underwent BoNT-A infiltration with sevoflurane sedation from November 2012 to December 2019. Demographic, clinical and functional characteristics, the effectiveness of sedation, adverse events (AE) and professional satisfaction were reviewed. Results: A total of 387 sedations were successfully performed in 74 patients. Effective sedation was achieved in 100% of procedures, facilitating collaboration during infiltration and improving professional satisfaction. AE were reported in 6.02% of the procedures, the most frequent being nausea and vomiting (3.88%) and transient hypoxemia (2.07%). There were no severe AE. No association was found between the incidence of AE and the clinical and functional variables or risk before anaesthesia. Conclusion: Sevoflurane sedation shows promising results in terms of safety and effectiveness for the management of agitation and pain during BoNT-A infiltration in our daily clinical practice. In addition, it can facilitate infiltration, allowing examination under sedation and multilevel infiltration with good tolerance

Developing speaking competences in technical English for Spanish civil engineering students

[EN] Traditionally, Spanish schools of civil engineering provide their students a class on “Technical English” in order to develop their language skills. However, this class does not cover all the skills that the student would need in the labor market and mainly focuses in the reading and writing skills, and in a lower degree in the speaking and listening ones. This paper proposes a series of innovative and informal training activities (cine-forum on technical civil engineering topics and role playing on real professional situations) that allow Spanish civil engineering students to develop English skills that can rarely be worked in the classroom (i.e. speaking, negotiating and conversing), encouraging debate, participation, and fostering their self-confidence to speak about technical-English topics in public. Although the students’ level of English is much lower than expected, they all agree on the importance of technical English for their future career. The results also show the students’ lack in skills that are difficult to train in regular classes (speaking and talking). Consequently, this situation would require to provide complementary activities like the ones suggested in this project in order to develop these skills and increase the students’ demand for engineering classes taught in English.Romero De Ávila Serrano, V.; Diaz García, S.; Asensio Sánchez, L.; Lozano Galant, JA.; Moyano Enríquez De Salamanca, A.; Porras Soriano, R.; Poveda Bautista, E.... (2017). Developing speaking competences in technical English for Spanish civil engineering students. En Proceedings of the 3rd International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 1228-1236. https://doi.org/10.4995/HEAD17.2017.55641228123

Influence of sex on intracellular calcium homoeostasis in patients with atrial fibrillation

Altres ajuts: Fundació Marato TV3 [20152030/31].Atrial fibrillation (AF) has been associated with intracellular calcium disturbances in human atrial myocytes, but little is known about the potential influence of sex and we here aimed to address this issue. Alterations in calcium regulatory mechanisms were assessed in human atrial myocytes from patients without AF or with long-standing persistent or permanent AF. Patch-clamp measurements revealed that L-type calcium current (I ) density was significantly smaller in males with than without AF (−1.15 ± 0.37 vs. −2.06 ± 0.29 pA/pF) but not in females with AF (−1.88 ± 0.40 vs. −2.21 ± 0.0.30 pA/pF). In contrast, transient inward currents (I ) were more frequent in females with than without AF (1.92 ± 0.36 vs. 1.10 ± 0.19 events/min) but not in males with AF. Moreover, confocal calcium imaging showed that females with AF had more calcium spark sites than those without AF (9.8 ± 1.8 vs. 2.2 ± 1.9 sites/µm 2) and sparks were wider (3.0 ± 0.3 vs. 2.2 ± 0.3 µm) and lasted longer (79 ± 6 vs. 55 ± 8 ms), favouring their fusion into calcium waves that triggers I s and afterdepolarizations. This was linked to higher ryanodine receptor phosphorylation at s2808 in women with AF, and inhibition of adenosine A or beta-adrenergic receptors that modulate s2808 phosphorylation was able to reduce the higher incidence of I in women with AF. Perturbations of the calcium homoeostasis in AF is sex-dependent, concurring with increased spontaneous SR calcium release-induced electrical activity in women but not in men, and with diminished I density in men only. This work was supported by grants from The Spanish Ministry of Science Innovation and Universities