The development of self-regulated learning during the pre-clinical stage of medical school: a comparison between a lecture-based and a problem based curriculum

Society expects physicians to always improve their competencies and to be up to date with developments in their field. Therefore, an important aim of medical schools is to educate future medical doctors to become self-regulated, lifelong learners. However, it is unclear if medical students become better self-regulated learners during the pre-clinical stage of medical school, and whether students develop self-regulated learning skills differently, dependent on the educational approach of their medical school. In a cross-sectional design, we investigated the development of 384 medical students’ self-regulated learning skills with the use of the Self-Regulation of Learning Self-Report Scale. Next, we compared this development in students who enrolled in two distinct medical curricula: a problem-based curriculum and a lectured-based curriculum. Analysis showed that more skills decreased than increased during the pre-clinical stage of medical school, and that the difference between the curricula was mainly caused by a decrease in the skill evaluation in the lecture-based curriculum. These findings seem to suggest that, irrespective of the curriculum, self-regulated learning skills do not develop during medical school

Regulatory T Cells Phenotype in Different Clinical Forms of Chagas' Disease

CD25High CD4+ regulatory T cells (Treg cells) have been described as key players in immune regulation, preventing infection-induced immune pathology and limiting collateral tissue damage caused by vigorous anti-parasite immune response. In this review, we summarize data obtained by the investigation of Treg cells in different clinical forms of Chagas' disease. Ex vivo immunophenotyping of whole blood, as well as after stimulation with Trypanosoma cruzi antigens, demonstrated that individuals in the indeterminate (IND) clinical form of the disease have a higher frequency of Treg cells, suggesting that an expansion of those cells could be beneficial, possibly by limiting strong cytotoxic activity and tissue damage. Additional analysis demonstrated an activated status of Treg cells based on low expression of CD62L and high expression of CD40L, CD69, and CD54 by cells from all chagasic patients after T. cruzi antigenic stimulation. Moreover, there was an increase in the frequency of the population of Foxp3+ CD25HighCD4+ cells that was also IL-10+ in the IND group, whereas in the cardiac (CARD) group, there was an increase in the percentage of Foxp3+ CD25High CD4+ cells that expressed CTLA-4. These data suggest that IL-10 produced by Treg cells is effective in controlling disease development in IND patients. However, in CARD patients, the same regulatory mechanism, mediated by IL-10 and CTLA-4 expression is unlikely to be sufficient to control the progression of the disease. These data suggest that Treg cells may play an important role in controlling the immune response in Chagas' disease and the balance between regulatory and effector T cells may be important for the progression and development of the disease. Additional detailed analysis of the mechanisms on how these cells are activated and exert their function will certainly give insights for the rational design of procedure to achieve the appropriate balance between protection and pathology during parasite infections

Systems Biology Reveals Relevant Gaps in Fc-γR Expression, Impaired Regulatory Cytokine Microenvironment Interfaced With Anti-Trypanosoma cruzi IgG Reactivity in Cardiac Chagas Disease Patients

The systems biology approach has become an innovative tool when it comes to shedding light on the complex immune response underlying the development/maintenance of distinct clinical forms of Chagas disease. The goal of this study was to describe an integrative overview of Fc-γR expression, cytokine microenvironment and anti-Trypanosoma cruzi IgG interface in indeterminate-(IND) and cardiac-(CARD) patients. Data demonstrated that IND displayed an overall higher Fcγ-R expression (CD16; CD32; CD64) on neutrophils-(NEU), along with (CD16; CD64) on monocytes-(MON) as compared to CARD. Additionally, CARD presented an increased expression of CD32 in B-cells. While preserved frequency of IL-10-producing cells was observed in IND, decreased levels of IL-10+ phagocytes and enhanced TNF+ MON and NK-cells were observed in CARD. T. cruzi-antigen recall in vitro induces a general decrease of Fc-γR expression in Chagas disease patients, especially in CARD. Moreover, T. cruzi-antigen stimuli triggered a concomitant increase of IFN-γ+NEU/TNF+NK-cells and IL-10+MON/IL-10+B-cells in IND. Biomarker signatures further emphasized the contrasting Fc-γR expression and cytokine microenvironment observed in Chagas disease patients with distinct clinical forms. Up-regulation of Fc-γR expression (CD16 on NEU;MON;NK) was observed in IND, whereas a general decrease was reported for CARD. Moreover, while a mixed cytokine microenvironment (TNF; IL-10) was observed in IND, CARD presented a contrasting profile with up-regulation of TNF+NEU and IL-12+NEU. Integrative network analysis revealed a distinct assemblage of biomarkers, with CARD presenting a large number of negative internode connectivity in comparison with IND. The relevant gaps in Fc-γR expression and impaired regulatory cytokine microenvironment interfaced with the anti-T. cruzi IgG reactivity throughout an exacerbated negative connectivity may account for the development/maintenance of the clinical status of cardiac Chagas disease

Evidence of Different IL-1 beta Activation Pathways in Innate Immune Cells From Indeterminate and Cardiac Patients With Chronic Chagas Disease

Submitted by Nuzia Santos ([email protected]) on 2019-10-10T14:18:09Z No. of bitstreams: 1 Evidence of Different .pdf: 3085663 bytes, checksum: f6266a1b26d8964e822c9c9eceb9fb36 (MD5)Approved for entry into archive by Nuzia Santos ([email protected]) on 2019-10-10T14:22:16Z (GMT) No. of bitstreams: 1 Evidence of Different .pdf: 3085663 bytes, checksum: f6266a1b26d8964e822c9c9eceb9fb36 (MD5)Made available in DSpace on 2019-10-10T14:22:16Z (GMT). No. of bitstreams: 1 Evidence of Different .pdf: 3085663 bytes, checksum: f6266a1b26d8964e822c9c9eceb9fb36 (MD5) Previous issue date: 2019Fundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, Brasil / Universidade Federal de Minas Gerais. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto René Rachou. Grupo Integrado de Pesquisas em Biomarcadores. Belo Horizonte, MG, Brasil / Universidade Federal de Minas Gerais. Faculdade de Medicina. Departamento de Propedêutica Complementar. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto René Rachou. Grupo Integrado de Pesquisas em Biomarcadores. Belo Horizonte, MG, Brasil.Inflammatory Cell Dynamics Section. Center for Cancer Research. National Institute of Health. NIH, Bethesda, MD, USA.Universidade Federal de Minas Gerais. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brasil / Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais. Belo Horizonte, MG, Brasil.Fundação Oswaldo Cruz. Instituto René Rachou. Laboratório de Imunologia Celular e Molecular. Belo Horizonte, MG, Brasil / Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais. Belo Horizonte, MG, Brasil.Universidade Federal de Minas Gerais. Departamento de Morfologia. Laboratório de Biologia das Interações Celulares. Belo Horizonte, MG, Brasil.Background: Chagas cardiomyopathy is the main fibrosing myocarditis among known heart diseases. Development of cardiomyopathy has been related to extracellular matrix (ECM) remodeling, which are controlled by matrix metalloproteinases (MMPs) and cytokines, especially interleukin (IL)-1β. The convertion of 31KDa inactive precursor, the proIL-1β in 17KDa active IL-1β peptide, is controlled by caspase-1-dependent pathway, associated with inflammasomes. Other caspase-1 independent mechanisms mediated by proteases, especially as MMPs, have already been described. Methods: We evaluated IL-1β activation pathways in neutrophils and monocyte subsets from patients with different clinical forms of Chagas disease after T. cruzi antigen stimulation by multiparameter flow cytometry. Results: Our data demonstrated that Chagas patients with the indeterminate clinical form (IND) showed increased levels of IL-1β post-stimulation as well as increased expression of MMP-2, NLRP3, and CASP1, which are associated with the classical caspase-1-dependent pathway. Conversely, patients with the cardiac clinical form (CARD) showed increased IL-1β after stimulation associated with MMP-9 and alternative caspase-1-independent pathway. Conclusions: We suggest some distinct molecular mechanisms for production of IL-1β in innate immune cells from patients with different clinical forms of Chagas disease. MMP-2 and MMP-9 gelatinases are associated with distinct disease outcomes and IL-1β production

Blood leukocytes from benznidazole-treated indeterminate chagas disease patients display an overall type-1-modulated cytokine profile upon short-term in vitro stimulation with <it>trypanosoma cruzi</it> antigens

<p>Abstract</p> <p>Background</p> <p>Benznidazole (Bz)-chemotherapy is recommended to prevent Chagas disease progression, despite its limited efficacy during chronic disease. However, the host mechanisms underlying these benefits still remain to be elucidated.</p> <p>Methods</p> <p>In this study, we have used short-term whole blood cultures to describe the cytokine profile of Bz-treated Indeterminate Chagas disease patients-(INDt) as compared to untreated patients-(IND).</p> <p>Results</p> <p>Our findings showed that IND presented increased levels of IL-10⁺neutrophils, IL-12⁺ and IL-10⁺monocytes and IFN-γ⁺NK-cells. Moreover, IND showed slight increase of IL-4⁺CD4⁺T-cells and enhanced levels of IL-10⁺CD8⁺T-cells and B-cells. Additional analysis of cytokine Low and High producers also highlighted the presence of High cytokine producers within IND, including IL-10 from CD4+ T-cells and IFN-γ from CD8⁺ T-cells, as compared to NI. The Bz-treatment lead to an overall cytokine down-regulation in the innate and adaptive compartments, including low levels of IL-12⁺ and IL-10⁺neutrophils and monocytes, IFN-γ⁺NK-cells, IL-12⁺, TNF-α⁺, IFN-γ⁺ and IL-5⁺CD4⁺T-cells and IL-10⁺B-cells, along with basal levels of cytokine-expressing CD8⁺T-cells in INDt as compared to IND. The in vitro antigen stimulation shifted the cytokine profile toward a type 1-modulated profile, with increased levels of IL-12⁺ and IL-10⁺ monocytes, IFN-γ⁺ and IL-4⁺NK-cells along with TNF-α⁺ and IFN-γ⁺CD8⁺T-cells. Analysis of Low and High cytokine producers, upon in vitro antigen stimulation, further confirm these data.</p> <p>Conclusion</p> <p>Together, our findings showed that the Bz treatment of Indeterminate Chagas’ disease patients shifts the cytokine patterns of peripheral blood monocytes, NK-cells and CD8⁺ T-cells towards a long-lasting Type-1-modulated profile that could be important to the maintenance of a non-deleterious immunological microenvironment.</p