RESUMO
En los últimos años, se utilizan cada vez con más profusión los estudios de caso como parte de la investigación del paradigma cualitativo. Se aplica como método y también como estrategia para dar respuesta a problemas clínicos, sociales y educativos que difícilmente se pueden abordar desde un modelo más centrado en la explicación de los fenómenos, y no en la comprensión de los mismos. Este artículo tiene como objetivo valorar la contribución de los estudios de caso en la investigación científica, y las potencialidades de su aplicación en el ámbito de la Cultura Física y el Deporte. Mediante el análisis bibliográfico, se valora el estudio de caso, insertado en la metodología de la investigación cualitativa educativa. El investigador lo utiliza según sus objetivos particulares, se exponen estudios de caso en diferentes esferas de actuación de la cultura física y el deporte, de manera que propicia un acercamiento preliminar, se utiliza como método y como técnica en el procesamiento de la información recopilada; también como estrategia investigativa que permite profundizar en casos particulares, en los cuales se analiza y obtiene información valiosa en dependencia del objetivo planificado en la investigación. Se concluye que en el ámbito de la Cultura Física y el Deporte este tipo de investigaciones permite sistematizar estudios particulares distintivos y ejemplarizantes que constituyen una fuente enriquecedora para la docencia, la investigación y las prácticas de entrenadores, psicólogos, deportistas y demás especialistas.
Nos últimos anos, os estudos de caso têm sido cada vez mais usados como parte da pesquisa do paradigma qualitativo. Ele é aplicado como um método e também como uma estratégia para responder a problemas clínicos, sociais e educacionais que dificilmente podem ser abordados a partir de um modelo mais focado na explicação dos fenômenos, em vez de sua compreensão. O objetivo deste artigo é avaliar a contribuição dos estudos de caso na pesquisa científica e o potencial de sua aplicação no campo da cultura física e do esporte. Por meio de uma análise bibliográfica, avalia-se o estudo de caso, inserido na metodologia da pesquisa educacional qualitativa. O pesquisador o utiliza de acordo com seus objetivos particulares, os estudos de caso são apresentados em diferentes âmbitos de atuação na cultura física e no esporte, de modo que favorece uma abordagem preliminar, é utilizado como método e como técnica no processamento das informações coletadas; também como estratégia de pesquisa que permite um estudo aprofundado de casos particulares, nos quais são analisadas e obtidas informações valiosas, dependendo do objetivo planejado na pesquisa. Conclui-se que, no campo da Cultura Física e do Esporte, esse tipo de pesquisa permite a sistematização de estudos particulares distintos e exemplares que constituem uma fonte enriquecedora para o ensino, a pesquisa e as práticas de treinadores, psicólogos, esportistas e outros especialistas.
In recent years, case studies have been increasingly used as part of qualitative paradigm research. It is applied as a method and also as a strategy to respond to clinical, social and educational problems that can hardly be approached from a model more focused on the explanation of the phenomena, and not on the understanding of them. The aim of this article is to evaluate the contribution of the case studies in scientific research, and the potential of their application in the field of Physical Culture and Sport. By means of the bibliographic analysis, the case study is evaluated, inserted in the methodology of educational qualitative research. The researcher uses it according to his particular objectives, case studies are presented in different spheres of action of physical culture and sport, so that it provides a preliminary approach, it is used as a method and as a technique in the processing of the information collected; also, as a research strategy that allows to deepen in particular cases, in which valuable information is analyzed and obtained depending on the objective planned in the research. It is concluded that in the field of Physical Culture and Sport, this type of research allows systematizing particular distinctive and exemplary studies that constitute an enriching source for teaching, research and practices of coaches, psychologists, athletes and other specialists.
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In Chile, Piscirickettsia salmonis contains two genetically isolated genogroups, LF-89 and EM-90. However, the impact of a potential co-infection with these two variants on Salmonid Rickettsial Septicemia (SRS) in Atlantic salmon (Salmo salar) remains largely unexplored. In our study, we evaluated the effect of P. salmonis LF-89-like and EM-90-like co-infection on post-smolt Atlantic salmon after an intraperitoneal challenge to compare changes in disease dynamics and host immune response. Co-infected fish had a significantly lower survival rate (24.1%) at 21 days post-challenge (dpc), compared with EM-90-like single-infected fish (40.3%). In contrast, all the LF-89-like single-infected fish survived. In addition, co-infected fish presented a higher presence of clinical lesions than any of the single-infected fish. The gene expression of salmon immune-related biomarkers evaluated in the head kidney, spleen, and liver showed that the EM-90-like isolate and the co-infection induced the up-regulation of cytokines (e.g., il-1ß, ifnγ, il8, il10), antimicrobial peptides (hepdicin) and pattern recognition receptors (PRRs), such as TLR5s. Furthermore, in serum samples from EM-90-like and co-infected fish, an increase in the total IgM level was observed. Interestingly, specific IgM against P. salmonis showed greater detection of EM-90-like antigens in LF-89-like infected fish serum (cross-reaction). These data provide evidence that P. salmonis LF-89-like and EM-90-like interactions can modulate SRS disease dynamics in Atlantic salmon, causing a synergistic effect that increases the severity of the disease and the mortality rate of the fish. Overall, this study contributes to achieving a better understanding of P. salmonis population dynamics.
Assuntos
Coinfecção , Doenças dos Peixes , Piscirickettsia , Infecções por Piscirickettsiaceae , Salmo salar , Animais , Piscirickettsia/fisiologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/imunologia , Infecções por Piscirickettsiaceae/veterinária , Infecções por Piscirickettsiaceae/microbiologia , Coinfecção/veterinária , Coinfecção/microbiologia , Coinfecção/imunologia , Chile , Sepse/veterinária , Sepse/microbiologia , Sepse/imunologiaRESUMO
This study aimed to evaluate the effect of chemical gasification and HEPES as alternative systems to pH control during in vitro maturation on bovine oocytes competence. Groups of 20 bovine cumulus oocytes complexes (COCs) were randomly distributed and cultured for 24 h in one of the following experimental groups: (i) chemical reaction (ChRG) system: CO2 generated from sodium bicarbonate and citric acid reaction (ii) culture media TCM-HEPES (HEPES-G); and (iii) control group (CNTG) in conventional incubator. After in vitro maturation (IVM), the COCs were in vitro fertilized (IVF), and in vitro cultivated (IVC) in a conventional incubator. We evaluated oocyte nuclear maturation, cleavage and blastocyst rates, in addition to the relative mRNA expression of BAX, BMP-15, AREG and EREG genes in oocytes and cumulus cells. The proportion of oocytes in metaphase II was higher in CNTG and ChRG (77.57% and 77.06%) than in the HEPES-G (65.32%; p = .0408 and .0492, respectively). The blastocyst production was similar between CNTG and ChRG (26.20% and 28.47%; p = .4232) and lower (p = .001) in the HEPES-G (18.71%). The relative mRNA expression of BAX gene in cumulus cells was significantly higher (p = .0190) in the HEPES-G compared to the CNTG. Additionally, the relative mRNA expression of BMP-15 gene was lower (p = .03) in oocytes from HEPES-G compared to the CNTG. In conclusion, inadequate atmosphere control has a detrimental effect on oocyte maturation. Yet, the use of chemical gasification can be an efficient alternative to bovine COCs cultivation.
Assuntos
Fertilização in vitro , Técnicas de Maturação in Vitro de Oócitos , Oócitos , Animais , Bovinos , Técnicas de Maturação in Vitro de Oócitos/veterinária , Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos/efeitos dos fármacos , Fertilização in vitro/veterinária , Feminino , Meios de Cultura , Blastocisto/efeitos dos fármacos , Células do Cúmulo/efeitos dos fármacos , Dióxido de Carbono/farmacologia , Bicarbonato de Sódio/farmacologia , Ácido Cítrico/farmacologia , Técnicas de Cultura Embrionária/veterináriaRESUMO
Emerging evidence suggests that gender is a defining feature of personhood. Studies show that gender is the primary social category individuals use to perceive humanness and the social category most strongly related to seeing someone-or something-as human. However, the universality of gender's primacy in social perception and its precedence over other social categories like race and age have been debated. We examined the primacy of gender perception in the Mayangna community of Nicaragua, a population with minimal exposure to Western influences, to test whether the primacy of gender categorization in humanization is more likely to be a culturally specific construct or a cross-cultural and potentially universal phenomenon. Consistent with findings from North American populations [A. E. Martin, M. F. Mason, J. Pers. Soc. Psychol. 123, 292-315 (2022)], the Mayangna ascribed gender to nonhuman objects more strongly than any other social category-including age, race, sexual orientation, disability, and religion-and gender was the only social category that uniquely predicted perceived humanness (i.e., the extent to which a nonhuman entity was seen as "human"). This pattern persisted even in the most isolated subgroup of the sample, who had no exposure to Western culture or media. The present results thus suggest that gender's primacy in social cognition is a widely generalizable, and potentially universal, phenomenon.
Assuntos
Identidade de Gênero , Humanos , Masculino , Feminino , Adulto , Nicarágua , Percepção Social , Pessoa de Meia-Idade , Adulto JovemRESUMO
We evaluated the influence of different media plus various concentrations of Glial cell line-derived neurotrophic factor (GDNF) during the in vitro culture (IVC) of testicular tissues from prepubertal collared peccary. Testes from 5 individuals were collected, fragmented and cultured for 28 days (34°C and 5% CO2). Culture media were Dulbecco's modified essential medium (DMEM) or stem cell serum free media (StemPro-34™ SFM), both supplemented with various concentrations of GDNF (0, 10, or 20 ng/mL). Fragments were cultured on the flat surface of 0.75% agarose gel and were evaluated every 7 days for fragment area, histomorphology, cellular viability, and proliferative activity. Data were expressed as mean ± standard error and analyzed by Kruskal-Wallis's and Tukey test. Fragments area decreased over the 28 days-culture, regardless of the treatment. For morphology, the StemPro-37 SFM medium plus 10 ng/mL GDNF provided higher scores at all time points in comparison to DMEM using any GDNF concentration (p < .05). After 28 days, similar cellular viability (~70%) was observed in all treatments (p > .05). For proliferating cell nuclear antigen assay, only DMEM plus 10 ng/mL GDNF improved (p < .05) cellular proliferation on Days 14 and 28. Looking at argyrophilic nucleolar organizing regions, after 28 days, there were no differences among treatments regarding cell proliferative capacity for both spermatogonia and Sertoli cells (p > .05). In summary, the DMEM and StemPro-34 SFM are adequate medium for IVC of prepubertal peccary testicular tissue. Supplementation with GDNF, especially at a 10 ng/mL concentration, appears to be essential for the maintenance of cell survival and proliferation.
Assuntos
Sobrevivência Celular , Meios de Cultura , Fator Neurotrófico Derivado de Linhagem de Célula Glial , Testículo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/farmacologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Masculino , Testículo/citologia , Testículo/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura/farmacologia , Meios de Cultura/química , Proliferação de Células/efeitos dos fármacos , Carica , Técnicas de Cultura de Tecidos/métodosRESUMO
Hyaline cartilage is a highly specialized tissue. When injured, its repair capacity is low, which results in the massive destruction of the articular surface. Using tissue engineering and genetic engineering techniques, it is possible to provide a suitable microenvironment providing chondrocyte growth factors involved in the development of hyaline cartilage proteins, as well as cell proliferation and differentiation. Our aim was to stimulate the synthesis of an extracellular matrix via the chondrocytes included in a fibrin matrix through the addition or overexpression of IGF1 and/or FGF2, while maintaining a constant agitation of the culture medium. Collagen type II and glycosaminoglycans increased during the entire incubation time. In contrast, collagen type I decreased its expression under the same culture conditions, transfecting or supplementing growth factors to chondrocytes. However, chondrocytes that were not transfected or supplemented showed a general increase in the proteins analyzed in this study. The presence of IGF1 and FGF2 increased the protein synthesis of the hyaline cartilage, regardless of which one was the source of growth factors. Continuous agitation using the spinner flask allows for the adequate nutrition of chondrocytes included in the fibrin matrix. However, they require growth factors to up-regulate or down-regulate collagenous proteins.
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A three-dimensional (3D) cell culture can more precisely mimic tissues architecture and functionality, being a promising alternative model to study disease pathophysiology and drug screening. Chagas disease (CD) is a neglected parasitosis that affects 7 million people worldwide. Trypanosoma cruzi's (T. cruzi) mechanisms of invasion/persistence continue to be elucidated. Benznidazole (BZ) and Nifurtimox (NF) are trypanocidal drugs with few effects on the clinical manifestations of the chronic disease. Chronic Chagas cardiomyopathy (CCC) is the main manifestation of CD due to its frequency and severity. The development of fibrosis and hypertrophy in cardiac tissue can lead to heart failure and sudden death. Thus, there is an urgent need for novel therapeutic options. Our group has more than fifteen years of expertise using 3D primary cardiac cell cultures, being the first to reproduce fibrosis and hypertrophy induced by T. cruzi infection in vitro. These primary cardiac spheroids exhibit morphological and functional characteristics that are similar to heart tissue, making them an interesting model for studying CD cardiac fibrosis. Here, we aim to demonstrate that our primary cardiac spheroids are great preclinical models which can be used to develop new insights into CD cardiac fibrosis, presenting advances already achieved in the field, including disease modeling and drug screening.
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The understanding of anti-tumor drug effects requires specific experimental settings which model clinical scenarios. We describe a protocol for 10-day treatment of lowly aggressive tumor cell lines with antineoplastic agents at concentrations which do not affect cell growth. We describe steps for seeding cells and treating cells with anti-tumor drugs. We then detail steps for cell sensitivity, cell proliferation, and mRNA and protein expression assays. We also detail assays to determine modifications in compound efflux. For complete details on the use and execution of this protocol, please refer to Rios Medrano et al.1.
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HER2-targeted therapies, such as Trastuzumab (Tz), have significantly improved the clinical outcomes for patients with HER2+ breast cancer (BC). However, treatment resistance remains a major obstacle. To elucidate functional and metabolic changes associated with acquired resistance, we characterized protein profiles of BC Tz-responder spheroids (RSs) and non-responder spheroids (nRSs) by a proteomic approach. Three-dimensional cultures were generated from the HER2+ human mammary adenocarcinoma cell line BT-474 and a derived resistant cell line. Before and after a 15-day Tz treatment, samples of each condition were collected and analyzed by liquid chromatography-mass spectrometry. The analysis of differentially expressed proteins exhibited the deregulation of energetic metabolism and mitochondrial pathways. A down-regulation of carbohydrate metabolism and up-regulation of mitochondria organization proteins, the tricarboxylic acid cycle, and oxidative phosphorylation, were observed in nRSs. Of note, Complex I-related proteins were increased in this condition and the inhibition by metformin highlighted that their activity is necessary for nRS survival. Furthermore, a correlation analysis showed that overexpression of Complex I proteins NDUFA10 and NDUFS2 was associated with high clinical risk and worse survival for HER2+ BC patients. In conclusion, the non-responder phenotype identified here provides a signature of proteins and related pathways that could lead to therapeutic biomarker investigation.