Implementación de técnicas para el aprendizaje grupal en estudiantes que cursan la asignatura de Diagnóstico Parasitológico de la carrera de Licenciatura en Laboratorio Clínico, Facultad Multidisciplinaria Oriental, Universidad de El Salvador. Año 2019

RESUMEN: El aprendizaje grupal es un proceso de interacción e influencia mutua en el que intervienen en interjuego dinámico los miembros del grupo, el profesor, las actividades conjuntas, las tareas, los métodos, técnicas grupales y los contenidos que se han de asimilar. La implementación de las técnicas para aprendizaje grupal incrementan la calidad de los aprendizajes y favorecen la adquisición de conocimientos a través de la interacción de las relaciones que se dan entre los integrantes, trabajar con técnicas grupales permite mejorar las habilidades sociales del diálogo, facilitar la comunicación, y la capacidad de participar, fomentando la cooperatividad e integración de las diversas opiniones e ideas en el logros de los objetivos planteados en el proceso de enseñanza-aprendizaje. OBJETIVO: Implementar técnicas que propicien el aprendizaje grupal en estudiantes que cursan la asignatura de Diagnóstico Parasitológico de la carrera de Licenciatura en Laboratorio Clínico, Facultad Multidisciplinaria Oriental, Universidad de El Salvador. Año 2019 METODOLOGÍA: La investigación fue de tipo cualitativo, documental, descriptiva y de campo, para este estudio se realizó una recopilación de información procedente de 53 estudiantes que cursaron la asignatura de Diagnóstico Parasitológico durante el Ciclo Académico II-2019, con la finalidad de conocer la importancia de la implementación de técnicas para aprendizaje grupal, dicha información se obtuvo a través de cuestionarios y pruebas objetivas. RESULTADOS: Los estudiantes que cursaron la asignatura de Diagnóstico Parasitológico donde se implementaron las técnicas para aprendizaje grupal, concuerdan que con la aplicación de éstas se propicia una mayor interacción y comunicación entre los compañeros y docentes, así como también una mejor comprensión de los contenidos abordados en las clases y por lo tanto esto conlleva a una mejora en el rendimiento académico. REFLEXIÓNES FINALES: Según la información recopilada se confirma que con la implementación de las técnicas para aprendizaje grupal se incrementa la integración y conocimiento de grupo; así como también se acelera la asimilación de contenidos en los estudiantes. ABSTRAC: Group learning is a process of mutual interaction and influence in which group members, the teacher, joint activities, tasks, methods, group techniques and the contents to be assimilated intervene in dynamic interplay. The implementation of techniques for group learning increases the quality of learning and favors the acquisition of knowledge through the interaction of the relationships that exist between the members, working with group techniques allows improving the social skills of dialogue, facilitating communication , and the ability to participate, promoting cooperativity and integration of various opinions and ideas in achieving the objectives set in the teaching-learning process. OBJECTIVE: To implement techniques that promote group learning in students who take the Parasitological Diagnosis course of the Clinical Laboratory Bachelor's degree, Oriental Multidisciplinary Faculty, University of El Salvador. Year 2019 METHODOLOGY: The research was qualitative, documentary, descriptive and field, for this study a compilation of information was made from 53 students who took the subject of Parasitological Diagnosis during the Academic Cycle II-2019, in order to know the importance of the implementation of techniques for group learning, said information was obtained through questionnaires and objective tests. RESULTS: The students who took the Parasitological Diagnosis subject where the techniques for group learning were implemented, agree that their application encourages greater interaction and communication between classmates and teachers, as well as a better understanding of the contents addressed in classes and therefore this leads to an improvement in academic performance. FINAL REFLECTIONS: According to the information collected, it is confirmed that with the implementation of techniques for group learning, integration and group knowledge increases; as well as the assimilation of content in students is accelerate

Formation and nanoscale characterization of asymmetric supported lipid bilayers containing raft-like domains

The development of new strategies for achieving stable asymmetric membrane models has turned interleaflet lipid asymmetry into a topic of major interest. Cyclodextrin-mediated lipid exchange constitutes a simple and versatile method for preparing asymmetric membrane models without the need for sophisticated equipment. Here we describe a protocol for preparing asymmetric supported lipid bilayers mimicking membrane rafts by cyclodextrin-mediated lipid exchange and the main guidelines for obtaining structural information and quantitative measures of their mechanical properties using Atomic force microscopy and Force spectroscopy; two powerful techniques that allow membrane characterization at the nanoscale.Fil: Vazquez, Romina Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; ArgentinaFil: Ovalle García, Erasmo. Universidad Nacional Autónoma de México; MéxicoFil: Antillón, Armando. Universidad Nacional Autónoma de México; MéxicoFil: Ortega Blake, Iván. Universidad Nacional Autónoma de México; MéxicoFil: Muñoz Garay, Carlos. Universidad Nacional Autónoma de México; MéxicoFil: Maté, Sabina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner"; Argentin

The amino- and carboxyl-terminal fragments of the Bacillus thuringensis Cyt1Aa toxin have differential roles on toxin oligomerization and pore formation

The Cyt toxins produced by the bacteria Bacillus thuringiensis show insecticidal activity against some insects, mainly dipteran larvae, being able to kill mosquitoes and black flies. However, they also possess a general cytolytic activity in vitro showing hemolytic activity in red blood cells. These proteins are composed of two outer layers of α-helix hairpins wrapped around a β-sheet. Regarding to their mode of action, one model proposed that the two outer layers of α-helix hairpins swing away from the β-sheet allowing insertion of β-strands into the membrane forming a pore after toxin oligomerization. The other model suggested a detergent-like mechanism of action of the toxin on the surface of the lipid bilayer. In this work we cloned the N- and C-terminal domains form Cyt1Aa and analyzed their effects in Cyt1Aa toxin action. The N-terminal domain shows a dominant negative phenotype inhibiting the in vitro hemolytic activity of Cyt1Aa in red blood cells and the in vivo insecticidal activity of Cyt1Aa against Aedes aegypti larvae. In addition, N-terminal region is able to induce aggregation of Cyt1Aa toxin in solution. Finally, Cterminal domain composed mainly of β-strands, is able to bind to the SUV liposomes, suggesting that this region of the toxin is involved in membrane interaction. Overall, our data indicate that the two isolated domains of Cyt1Aa have different roles in toxin action. The N-terminal region is involved in toxin aggregation while the C-terminal domain in the interaction of the toxin with the lipid membrane.Research was funded in part through grants from the National Institutes of Health, 1R01 AI066014, DGAPA/UNAM IN218608 and IN210208-N, CONACyT U48631-Q 478. IRdE received a José Castillejo postdoctoral grant, and a mobility grant for teaching and research staff of UPNA, Spain

Dual regulation of the T-type Ca2+ current by serum albumin and β-estradiol in mammalian spermatogenic cells

AbstractThis study provides evidence for a novel mechanism of voltage-gated Ca2+ channel regulation in mammalian spermatogenic cells by two agents that affect sperm capacitation and the acrosome reaction (AR). Patch-clamp experiments demonstrated that serum albumin induced an increase in Ca2+ T current density in a concentration-dependent manner, and significant shifts in the voltage dependence of both steady-state activation and inactivation of the channels. These actions were not related to the ability of albumin to remove cholesterol from the membrane. In contrast, β-estradiol significantly inhibited Ca2+ channel activity in a concentration-dependent and essentially voltage-independent fashion. In mature sperm this dual regulation may influence capacitation and/or the AR

Immune response to SARS-CoV-2 variants after immunization with different vaccines in Mexico

There is limited information on the antibody responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in subjects from developing countries with populations having a high incidence of co-morbidities. Here, we analysed the immunogenicity of homologous schemes using the ChAdOx1-S, Sputnik V, or BNT162b2 vaccines and the effect of a booster dose with ChAdOx1-S in middle-aged adults who were seropositive or seronegative to the SARS-CoV-2 spike protein before vaccination. The study was conducted post-vaccination with a follow-up of 4 months for antibody titre using enzyme-linked immunosorbent assay (ELISA) and pseudovirus (PV) neutralization assays (PNAs). All three vaccines elicited a superior IgG anti-receptor-binding domain (RBD) and neutralization response against the Alpha and Delta variants when administered to individuals with a previous infection by SARS-CoV-2. The booster dose spiked the neutralization activity among individuals with and without a prior SARS-CoV-2 infection. The ChAdOx1-S vaccine induced weaker antibody responses in infection-naive subjects. A follow-up of 4 months post-vaccination showed a drop in antibody titre, with about 20% of the infection-naive and 100% of SARS-CoV-2 pre-exposed participants with detectable neutralization capacity against Alpha pseudovirus (Alpha-PV) and Delta PV (Delta-PV). Our observations support the use of different vaccines in a country with high seroprevalence at the vaccination time

Asymmetric bilayers mimicking membrane rafts prepared by lipid exchange: nanoscale characterization using AFM-Force spectroscopy

Sphingolipids-enriched rafts domains are proposed to occur in plasma membranes and to mediate important cellular functions. Notwithstanding, the asymmetric transbilayer distribution of phospholipids that exists in the membrane confers the two leaflets different potentials to form lateral domains as next to no sphingolipids are present in the inner leaflet. How the physical properties of one leaflet can influence the properties of the other and its importance on signal transduction across the membrane are questions still unresolved. In this work, we combined AFM imaging and Force spectroscopy measurements to assess domain formation and to study the nanomechanical properties of asymmetric supported lipid bilayers (SLBs) mimicking membrane rafts. Asymmetric SLBs were formed by incorporating N-palmitoyl-sphingomyelin (16:0SM) into the outer leaflet of preformed 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC)/Cholesterol SLBs through methyl-β-cyclodextrin– mediated lipid exchange. Lipid domains were detected after incorporation of 16:0SM though their phase state varied from gel to liquid ordered (Lo) phase if the procedure was performed at 24 or 37 °C, respectively. When comparing symmetric and asymmetric Lo domains, differences in size and morphology were observed, with asymmetric domains being smaller and more interconnected. Both types of Lo domains showed similar mechanical stability in terms of rupture forces and Young's moduli. Notably, force curves in asymmetric domains presented two rupture events that could be attributed to the sequential rupture of a liquid disordered (Ld) and a Lo phase. Interleaflet coupling in asymmetric Lo domains could also be inferred from those measurements. The experimental approach outlined here would significantly enhance the applicability of membrane models.Instituto de Investigaciones Bioquímicas de La PlataCentro de Investigación de Proteínas Vegetale

Bacillus thuringiensis Cry1A toxins are versatile proteins with multiple modes of action: two distinct pre-pores are involved in toxicity

Cry proteins from Bacillus thuringiensis are insecticidal PFTs (pore-forming toxins). In the present study, we show that two distinct functional pre-pores of Cry1Ab are formed after binding of the protoxin or the protease-activated toxin to the cadherin receptor, but before membrane insertion. Both pre-pores actively induce pore formation, although with different characteristics, and contribute to the insecticidal activity. We also analysed the oligomerization of the mutant Cry1AbMod protein. This mutant kills different insect populations that are resistant to Cry toxins, but lost potency against susceptible insects. We found that the Cry1AbMod-protoxin efficiently induces oligomerization, but not the activated Cry1AbMod-toxin, explaining the loss of potency of Cry1AbMod against susceptible insects. These data are relevant for the future control of insects resistant to Cry proteins. Our data support the pore-formation model involving sequential interaction with different midgut proteins, leading to pore formation in the target membrane. We propose that not only different insect targets could have different receptors, but also different midgut proteases that would influence the rate of protoxin/toxin activation. It is possible that the two pre-pore structures could have been selected for in evolution, since they have differential roles in toxicity against selected targets, increasing their range of action. These data assign a functional role for the protoxin fragment of Cry PFTs that was not understood previously. Most PFTs produced by other bacteria are secreted as protoxins that require activation before oligomerization, to finally form a pore. Thus different pre-pores could be also part of the general mechanism of action of other PFTs

Dominant Negative Mutants of Bacillus thuringiensis Cry1Ab Toxin Function as Anti-Toxins: Demonstration of the Role of Oligomerization in Toxicity

BACKGROUND:Bacillus thuringiensis Cry toxins, that are used worldwide in insect control, kill insects by a mechanism that depends on their ability to form oligomeric pores that insert into the insect-midgut cells. These toxins are being used worldwide in transgenic plants or spray to control insect pests in agriculture. However, a major concern has been the possible effects of these insecticidal proteins on non-target organisms mainly in ecosystems adjacent to agricultural fields. METHODOLOGY/PRINCIPAL FINDINGS:We isolated and characterized 11 non-toxic mutants of Cry1Ab toxin affected in different steps of the mechanism of action namely binding to receptors, oligomerization and pore-formation. These mutant toxins were analyzed for their capacity to block wild type toxin activity, presenting a dominant negative phenotype. The dominant negative phenotype was analyzed at two levels, in vivo by toxicity bioassays against susceptible Manduca sexta larvae and in vitro by pore formation activity in black lipid bilayers. We demonstrate that some mutations located in helix alpha-4 completely block the wild type toxin activity at sub-stoichiometric level confirming a dominant negative phenotype, thereby functioning as potent antitoxins. CONCLUSIONS/SIGNIFICANCE:This is the first reported case of a Cry toxin dominant inhibitor. These data demonstrate that oligomerization is a fundamental step in Cry toxin action and represent a potential mechanism to protect special ecosystems from the possible effect of Cry toxins on non-target organisms

A personalized intervention to prevent depression in primary care: cost-effectiveness study nested into a clustered randomized trial

Abstract Background: Depression is viewed as a major and increasing public health issue, as it causes high distress in the people experiencing it and considerable financial costs to society. Efforts are being made to reduce this burden by preventing depression. A critical component of this strategy is the ability to assess the individual level and profile of risk for the development of major depression. This paper presents the cost-effectiveness of a personalized intervention based on the risk of developing depression carried out in primary care, compared with usual care. Methods: Cost-effectiveness analyses are nested within a multicentre, clustered, randomized controlled trial of a personalized intervention to prevent depression. The study was carried out in 70 primary care centres from seven cities in Spain. Two general practitioners (GPs) were randomly sampled from those prepared to participate in each centre (i.e. 140 GPs), and 3326 participants consented and were eligible to participate. The intervention included the GP communicating to the patient his/her individual risk for depression and personal risk factors and the construction by both GPs and patients of a psychosocial programme tailored to prevent depression. In addition, GPs carried out measures to activate and empower the patients, who also received a leaflet about preventing depression. GPs were trained in a 10- to 15-h workshop. Costs were measured from a societal and National Health care perspective. Qualityadjustedlife years were assessed using the EuroQOL five dimensions questionnaire. The time horizon was 18 months.This work was supported by grants from the Spanish Ministry of Health, the Institute of Health Carlos III (ISCIII) and the European Regional Development Fund (ERDF) ’A way to build Europe’(grant references PS09/02272, PS09/02147, PS09/01095, PS09/00849 and PS09/00461); the Andalusian Council of Health (grant reference PI-0569-2010); the Spanish Network of Primary Care Research ’redIAPP’ (RD06/0018, RD12/0005/0001); the ’Aragón group’ (RD06/0018/0020, RD12/0005/0006); the ’Bizkaya group’ (RD06/0018/0018, RD12/0005/0010); the Castilla-León Group (RD06/0018/0027); the Mental Health (SJD) Barcelona Group (RD06/0018/0017, RD12/0005/0008); and the Mental-Health, Services and Primary Care (SAMSERAP) MálagaGroup (RD06/0018/0039, RD12/0005/0005)

Mutational Landscape of CEBPA in Mexican Pediatric Acute Myeloid Leukemia Patients: Prognostic Implications

BackgroundIn Mexico, the incidence of acute myeloid leukemia (AML) has increased in the last few years. Mortality is higher than in developed countries, even though the same chemotherapy protocols are used. CCAAT Enhancer Binding Protein Alpha (CEBPA) mutations are recurrent in AML, influence prognosis, and help to define treatment strategies. CEBPA mutational profiles and their clinical implications have not been evaluated in Mexican pediatric AML patients.Aim of the StudyTo identify the mutational landscape of the CEBPA gene in pediatric patients with de novo AML and assess its influence on clinical features and overall survival (OS).Materials and MethodsDNA was extracted from bone marrow aspirates at diagnosis. Targeted massive parallel sequencing of CEBPA was performed in 80 patients.ResultsCEBPA was mutated in 12.5% (10/80) of patients. Frameshifts at the N-terminal region were the most common mutations 57.14% (8/14). CEBPA biallelic (CEBPABI) mutations were identified in five patients. M2 subtype was the most common in CEBPA positive patients (CEBPAPOS) (p = 0.009); 50% of the CEBPAPOS patients had a WBC count > 100,000 at diagnosis (p = 0.004). OS > 1 year was significantly better in CEBPA negative (CEBPANEG) patients (p = 0.0001). CEBPAPOS patients (either bi- or monoallelic) had a significantly lower OS (p = 0.002). Concurrent mutations in FLT3, CSF3R, and WT1 genes were found in CEBPAPOS individuals. Their contribution to poor OS cannot be ruled out.ConclusionCEBPA mutational profiles in Mexican pediatric AML patients and their clinical implications were evaluated for the first time. The frequency of CEBPAPOS was in the range reported for pediatric AML (4.5–15%). CEBPA mutations showed a negative impact on OS as opposed to the results of other studies