El uso de la simulación en la enseñanza de la medicina

La simulación clínica es una técnica que permite reemplazar experiencias reales con experiencias ficticias intentando reproducir con mayor o menor fidelidad las circunstancias que el alumno va a enfrentar en su futura vida profesional. Es un recurso didáctico útil para entrenar alumnos y graduados en diversos procedimientos más o menos invasivos como intubación traqueal, punción lumbar, resucitación cardiopulmonar, cirugía laparoscópica, etc. Permite además el desarrollo de la capacidad de comunicación, ejercicio de liderazgo y trabajo en equipo entre otras competencias. Varias son las razones por las que la simulación está adquiriendo mayor importancia en la enseñanza no sólo de la Medicina sino también de otras Ciencias de la Salud. Una relevante es que la seguridad del paciente ha pasado a ser un tema prioritario en la atención médica limitando las prácticas de los alumnos en los hospitales. Con el uso de simuladores el estudiante puede repetir los procedimientos hasta alcanzar la competencia sin temor a dañar al paciente. En esta revisión daremos una visión general del concepto de simulación clínica, y de las ventajas y dificultades de su aplicación en la enseñanza de la Medicina.Clinical simulation is a technique that allows to replace real experiences with fictitious ones trying to reproduce with greater or less fidelity the circumstances that the students will face in their future professional life. It is a didactic tool that permits training in various procedures more or less invasive such as tracheal intubation, lumbar puncture, cardiopulmonary resuscitation, laparoscopic surgery, etc. It also allows to develop communication, leadership and teamwork skills, among many others. There are several reasons why simulation is becoming more important in the teaching not only of Medicine but also of other Health Sciences. One relevant point is that patient safety has become a priority issue in medical care, limiting student practices in hospitals. With the use of simulators the student can repeat the procedures until reach the competency without the risk of damaging the patient. In this review we will give an overview of the concept of clinical simulation, and the advantages and difficulties of its application in the teaching of Medicine.Sociedad Argentina de Fisiologí

A precise DNA bend angle is essential for the function of the phage φ29 transcriptional regulator

Bacteriophage φ29 protein p4 is essential for the regulation of the switch from early to late phage transcription. The protein binds to two regions of the phage genome located between the regulated promoters. Each region contains two inverted repeats separated by 1 bp. We used circular permutation assays to study the topology of the DNA upon binding of the protein and found that p4 induced the same extent of bending independent of the topology of the binding region. In addition, the results revealed that the p4-induced bending is not dependent on the affinity to the binding site but is intrinsic to p4 binding. Independent binding sites were identified through the characterization of the minimal sequence required for p4 binding. The protein has different affinity for each of its binding sites, with those overlapping the A2c and A2b promoter cores (sites 1 and 3), having the highest affinity. The functionality of the p4 binding sites and the contribution of p4-mediated promoter restructuring in transcription regulation is discussed

Engineered viral DNA polymerase with enhanced DNA amplification capacity: a proof-of-concept of isothermal amplification of damaged DNA

© The Author(s) 2020.The development of whole genome amplification (WGA) and related methods, coupled with the dramatic growth of sequencing capacities, has changed the paradigm of genomic and genetic analyses. This has led to a continual requirement of improved DNA amplification protocols and the elaboration of new tailored methods. As key elements in WGA, identification and engineering of novel, faithful and processive DNA polymerases is a driving force in the field. We have engineered the B-family DNA polymerase of virus Bam35 with a C-terminal fusion of DNA-binding motifs. The new protein, named B35-HhH, shows faithful DNA replication in the presence of magnesium or an optimised combination of magnesium and manganese divalent cofactors, which enhances the replication of damaged DNA substrates. Overall, the newly generated variant displays improved amplification performance, sensitivity, translesion synthesis and resistance to salt, which are of great interest for several applications of isothermal DNA amplification. Further, rolling-circle amplification of abasic site-containing minicircles provides a proof-of-concept for using B35-HhH for processive amplification of damaged DNA samples.This work was funded by grants from Spanish Ministry of Science, Innovation and Universities [PGC2018-093726-B-100 AEI/FEDER UE to M.S. and PGC2018-093723-A-100 to M.R.R.] and a ComFuturo Grant from Fundación General CSIC [NewPols4Biotech to M.R-R.]. C.D. O. and A. L. were holders of a PhD fellowship [FPU16/02665 and FPU15/05797, respectively] from the Spanish Ministry of Science, Innovation and Universities. An institutional grant from Fundación Ramón Areces and Banco Santander to the Centro de Biología Molecular Severo Ochoa is also acknowledged. Tis paper is dedicated to the memory of Prof. Margarita Salas, an irreplaceable researcher and mentor

Phage Ø29 Protein p6 Is in a Monomer−Dimer Equilibrium That Shifts to Higher Association States at the Millimolar Concentrations Found in Vivo

Protein p6 from Bacillus subtilis phage Ø29 (Mr = 11 800) binds in vitro to DNA forming a large nucleoprotein complex in which the DNA wraps a multimeric protein core. The high intracellular abundance of protein p6 together with its ability to bind the whole Ø29 DNA in vitro strongly suggests that it plays a role in viral genome organization. We have determined by sedimentation equilibrium analysis that protein p6 (1−100 μM range), in the absence of DNA, is in a monomer−dimer equilibrium, with an association constant (K2) of 2 × 105 M-1. The intracellular concentration of protein p6 (1 mM) was estimated measuring the number of copies per cell (7 × 105) and the cell volume (1 × 10-15 L). At concentrations around 1 mM, protein p6 associates into oligomers. This self-association behavior is compatible with a dimer−hexamer model (K2,6 = 3.2 × 108 M-2) or with an isodesmic association of the dimer (K = 950 M-1), because the apparent weight-average molecular mass (Mw,a) does not reach saturation at the highest protein concentrations. The sedimentation coefficients of protein p6 monomer and dimer were 1.4 and 2.0, respectively, compatible with translational frictional ratios (f/fo) of 1.15 and 1.30, which slightly deviate from the hydrodynamics of a rigid globular protein. Taking together these results and considering the structure of the nucleoprotein complex, we speculate that the observed oligomers of protein p6 could mimic a scaffold on which DNA folds to form the nucleoprotein complex in vivo.Peer reviewe

Efecto antiproliferativo y proapoptótico de las estaninas en tumores subcutáneos de A549 implantados en ratones nude

La familia de las estatinas está constituida por drogas naturales (de origen fúngico), semisintéticas (obtenidas por modificaciones de las anteriores) y sintéticas. Estos compuestos son estructuralmente similares a la mevalonolactona, característica que les posibilita actuar como inhibidores competitivos de la 3-hidroxi-3-metil glutaril CoA reductasa. Esta enzima cataliza la conversión de HMG-CoA en mevalonato y constituye el punto clave en la regulación de la velocidad de la llamada vía del mevalonato Esta es una ruta metabólica muy ramificada donde, además de colesterol (producto final mayoritario), se generan otros productos finales que desempeñan importantes funciones en la célula como dolicol (participa en la glicosilación de proteínas), ubiquinona (constituyente de la cadena transportadora de electrones de mitocondrias) y grupos isopreno de proteínas isopreniladas (involucradas en vías de transducción de señales relacionadas con la proliferación celular). Uno de los posibles efectos de las estatinas es la modulación del crecimiento celular. Las proteínas Ras y Rho, para las cuales la prenilación es indispensable para su actividad, regulan señales de traducción que se encargan de la transcripción de genes involucrados en la proliferación y diferenciación celular, así como en la apoptosis. Mutaciones en los genes que codifican por estas proteínas forman oncogenes encontrados en una amplia variedad de tumores; por ejemplo, en un 90% de las neoplasias de páncreas, 50% de las tumoraciones de colon y tiroides y, aproximadamente, en un 30% de las leucemias mieloides y en el cáncer de pulmón.Facultad de Ciencias Médica

Angiotensin II-induced oxidative stress resets the Ca2+ dependence of Ca2+-calmodulin protein kinase II and promotes a death pathway conserved across different species

Rationale: Angiotensin (Ang) II-induced apoptosis was reported to be mediated by different signaling molecules. Whether these molecules are either interconnected in a single pathway or constitute different and alternative cascades by which Ang II exerts its apoptotic action, is not known. Objective: To investigate in cultured myocytes from adult cat and rat, 2 species in which Ang II has opposite inotropic effects, the signaling cascade involved in Ang II-induced apoptosis. Methods and results: Ang II (1 μmol/L) reduced cat/rat myocytes viability by ≈40%, in part, because of apoptosis (TUNEL/caspase-3 activity). In both species, apoptosis was associated with reactive oxygen species (ROS) production, Ca2+/calmodulin-dependent protein kinase (CaMK)II, and p38 mitogen-activated protein kinase (p38MAPK) activation and was prevented by the ROS scavenger MPG (2-mercaptopropionylglycine) or the NADPH oxidase inhibitor DPI (diphenyleneiodonium) by CaMKII inhibitors (KN-93 and AIP [autocamtide 2-related inhibitory peptide]) or in transgenic mice expressing a CaMKII inhibitory peptide and by the p38MAPK inhibitor, SB202190. Furthermore, p38MAPK overexpression exacerbated Ang II-induced cell mortality. Moreover, although KN-93 did not affect Ang II-induced ROS production, it prevented p38MAPK activation. Results further show that CaMKII can be activated by Ang II or H2O2, even in the presence of the Ca 2+chelator BAPTA-AM, in myocytes and in EGTA-Ca2-free solutions in the presence of the calmodulin inhibitor W-7 in in vitro experiments. Conclusions: (1) The Ang II-induced apoptotic cascade converges in both species, in a common pathway mediated by ROS-dependent CaMKII activation which results in p38MAPK activation and apoptosis. (2) In the presence of Ang II or ROS, CaMKII may be activated at subdiastolic Ca2+concentrations, suggesting a new mechanism by which ROS reset the Ca2+dependence of CaMKII to extremely low Ca2+levels.Facultad de Ciencias Médica

Angiotensin II-induced oxidative stress resets the Ca2+ dependence of Ca2+-calmodulin protein kinase II and promotes a death pathway conserved across different species

Rationale: Angiotensin (Ang) II-induced apoptosis was reported to be mediated by different signaling molecules. Whether these molecules are either interconnected in a single pathway or constitute different and alternative cascades by which Ang II exerts its apoptotic action, is not known. Objective: To investigate in cultured myocytes from adult cat and rat, 2 species in which Ang II has opposite inotropic effects, the signaling cascade involved in Ang II-induced apoptosis. Methods and results: Ang II (1 μmol/L) reduced cat/rat myocytes viability by ≈40%, in part, because of apoptosis (TUNEL/caspase-3 activity). In both species, apoptosis was associated with reactive oxygen species (ROS) production, Ca2+/calmodulin-dependent protein kinase (CaMK)II, and p38 mitogen-activated protein kinase (p38MAPK) activation and was prevented by the ROS scavenger MPG (2-mercaptopropionylglycine) or the NADPH oxidase inhibitor DPI (diphenyleneiodonium) by CaMKII inhibitors (KN-93 and AIP [autocamtide 2-related inhibitory peptide]) or in transgenic mice expressing a CaMKII inhibitory peptide and by the p38MAPK inhibitor, SB202190. Furthermore, p38MAPK overexpression exacerbated Ang II-induced cell mortality. Moreover, although KN-93 did not affect Ang II-induced ROS production, it prevented p38MAPK activation. Results further show that CaMKII can be activated by Ang II or H2O2, even in the presence of the Ca 2+chelator BAPTA-AM, in myocytes and in EGTA-Ca2-free solutions in the presence of the calmodulin inhibitor W-7 in in vitro experiments. Conclusions: (1) The Ang II-induced apoptotic cascade converges in both species, in a common pathway mediated by ROS-dependent CaMKII activation which results in p38MAPK activation and apoptosis. (2) In the presence of Ang II or ROS, CaMKII may be activated at subdiastolic Ca2+concentrations, suggesting a new mechanism by which ROS reset the Ca2+dependence of CaMKII to extremely low Ca2+levels.Facultad de Ciencias Médica

Entrenamiento Basado en Simulación (EBS) en la Facultad de Ciencias Médicas (UNLP): estrategias didácticas

La puesta en marcha de la utilización sistemática y continua del Laboratorio de Habilidades y Destrezas a lo largo del ciclo clínico de la Carrera de Medicina y durante la Práctica Final Obligatoria (PFO), conlleva a la necesidad de capacitar al personal docente de las cátedras del ciclo clínico en estrategias de enseñanza con modelos de simulación.Facultad de Ciencias Médica

Chemical chaperones improve the functional recovery of stunned myocardium by attenuating the endoplasmic reticulum stress

Aim: Myocardial ischaemia/reperfusion (I/R) produces structural and functional alterations depending on the duration of ischaemia. Brief ischaemia followed by reperfusion causes reversible contractile dysfunction (stunned heart) but long-lasting ischaemia followed by reperfusion can result in irreversible injury with cell death. Events during I/R can alter endoplasmic reticulum (ER) function leading to the accumulation of unfolded/misfolded proteins. The resulting ER stress induces activation of several signal transduction pathways, known as unfolded protein response (UPR). Experimental evidence shows that UPR contributes to cell death in irreversible I/R injury; however, there is still uncertainty for its occurrence in the stunned myocardium. This study investigated the ER stress response and its functional impact on the post-ischaemic cardiac performance of the stunned heart. Methods: Perfused rat hearts were subjected to 20 minutes of ischaemia followed by 30 minutes of reperfusion. UPR markers were evaluated by qRT-PCR and western blot. Post-ischaemic mechanical recovery was measured in absence and presence of two chemical chaperones: tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid (4-PBA). Results: Analysis of mRNA and protein levels of various ER stress effectors demonstrated that different UPR signalling cascades, involving both pro-survival and pro-apoptotic pathways, are activated. Inhibition of the UPR with chemical chaperones improved the post-ischaemic recovery of cardiac mechanical function without affecting the I/R-induced increase in oxidative stress. Conclusion: Our results suggest that prevention of ER stress by chemical chaperones could be a therapeutic tool to limit deterioration of the contractile function in clinical settings in which the phenomenon of myocardial stunning is present.Fil: Mariángelo, Juan Ignacio Elio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Roman, Barbara Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Silvestri, María Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Salas, Margarita Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Vittone, Leticia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Said, Maria Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Mundiña, Cecilia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; Argentin

La enseñanza de la Fisiología en la Argentina

Objetivo: Realizar un diagnóstico de la enseñanza de la Fisiología en las cátedras de las facultades o escuelas de salud de la Argentina: analizar el cuerpo docente y las actividades de cada cátedra.Facultad de Ciencias Médica