Gamification and cooperative learning: effects of a hybridization in physical education / Gamificación y aprendizaje cooperativo: efectos de una hibridación en educación física

El presente estudio tuvo como objetivo evaluar el impacto de una unidad didáctica de Educación Física (EF) sobre la satisfacción en las clases de EF, la satisfacción de las necesidades psicológicas básicas, la motivación, el clima social escolar y el rendimiento cognitivo. Se utilizó un diseño cuasi-experimental con grupo control para una muestra total de 120 estudiantes de Educación Secundaria (M = 13,48; DT = 1,36) a los que se les administró un cuestionario para analizar las variables de estudio. Se aplicó la unidad didáctica basada en la hibridación de la gamificación y el aprendizaje cooperativo (GF + CL) durante 8 sesiones. El programa mostró mejoras en el índice de mediadores psicológicos, la función ejecutiva de la planificación, la satisfacción de los alumnos de educación física y el clima social escolar, lo que podría ser adecuado para mejorar el rendimiento de los profesores de educación física en los centros educativos. (AU)

The present study aimed to assess the impact of a Physical Education (PE) teaching unit on PE satisfaction classes, basic psychological needs satisfaction, motivation, school social climate and cognitive performance. A quasi-experimental design with a control group was used for a total sample of 120 students of Secondary Education (M = 13,48; SD = 1,36) to whom a questionnaire was administered to analyse the study variables. The teaching unit based on the hybridization of gamification and Cooperative Learning (GF + CL) was applied for 8 sessions. The programme showed improvements in the psychological mediators index, executive function of planning, the PE students satisfaction and the school social climate, which would make it suitable for the improvement in the performance of PE teachers in educational centres. (AU)

Structural characterization of two CD1A allelic variants.

CD1 molecules are specialized in presenting lipidic antigens to T lymphocytes. They are structurally and evolutionary related to MHC molecules and show very limited polymorphism. We have previously described and partially characterized a new human CD1A allele differing from the wild type CD1A by a substitution of Cysteine by Tryptophan at position 52 in the alpha1 domain of the CD1A molecule. The frequency of this allele varies from 10% in individuals of Caucasian origin to 56% in Chinese people. The aim of the present work was to structurally characterize this CD1A allele. To do this we have cloned and sequenced the full-length cDNA encoding the new CD1A allele. The cDNA sequence of this allele encodes a protein differing the wild type in two amino acids at positions 14 (Threonine versus Isoleucine) and 52 (Cysteine versus Tryptophan). The cDNAs encoding both wild type and mutant CD1A were cloned in the expression vector pSRalphaNeo and transfected into C1R and L721.221 cells. Cell surface expression of the protein products in transfected cell lines were analyzed by flow cytometry and immunoprecipitation using CD1a-specific monoclonal antibodies. Our results indicate that both allelic products are efficiently expressed on the cell surface.

Self and nonself stimulatory molecules induce preferential expansion of CD5+ B cells or activated T cells of chagasic patients, respectively.

It has previously been demonstrated that Trypanosoma cruzi-derived antigens (TRP) and human parasite-specific antibodies (Id) stimulate proliferation of cells from Chagasic patients. More recently, we have shown that activated T cells and CD5+ B cells are present in elevated levels in the peripheral blood of Chagasic patients. Upon in vitro exposure to these two different types of stimulatory molecules (TRP, Id), we now show that each of these elevated populations respond differentially to TRP or Id. We found that stimulation with TRP led to preferential expansion of activated T cells, while Id preferentially stimulated CD5+ B cells and CD8+ T cells. Moreover, this expansion of CD5+ B cells by Id was even more pronounced in cultures of cells from Chagasic patients with the severe, cardiac form of the disease, as compared to indeterminate patients. CD8+ T cells comprise approximately 50% of the total T cells in cultures stimulated by Id while in TRP-stimulated cultures their frequency is proportionally lower. Since parasite antigens and antiparasite antibodies are always present in the host during the chronic phase of the disease, they may also be involved with differential activation mechanisms of these cell populations in vivo.

Single strand conformational polymorphism analysis of human CD1 genes in different ethnic groups.

CD1 molecules are able to present unusual antigens, lipids or glycolipids from mycobacterium cell walls to T lymphocytes. Previous studies have suggested that polymorphism of these genes is very limited, in contrast with classical major histocompatibility complex (MHC) antigen-presenting molecules. Our aim was to study possible allelic variations of exons 2 and 3, encoding for the alpha1 and alpha2 domains, respectively, of human CD1A, -B, -C and -D genes. We analyzed genomic samples of unrelated, healthy individuals from different ethnic background: 70 Caucasians from Europe, 33 Black Africans (13 from Tanzania and 20 Zulus), 19 Caucasians from the Sahara and 44 Asian individuals. We have found CD1A to be a biallelic locus with a common allele which was present in the majority of the individuals studied. The second allele differed from the common one by a single-point mutation, resulting in a change of Cys to Trp at position 52 in the alpha1 domain. This second allele was found in heterozygosis in 7 out of 70 Caucasians from Europe (allelic frequencies P=0.95 and q=0.05). In the Chinese population, we found the second allele present in heterozygosis in 19 from the 44 individuals studied, and we also found 6 homozygous individuals for the second allele (allelic frequencies P=0.64 and q=0.35). In addition, we detected a synonymous mutation (C to T transition) in codon 34 of CD1C exon 2 in 4 out of 20 Zulus and in 2 of the 13 Blacks from Tanzania.

PCR amplification of the mitochondrial DNA minisatellite region to detect Schistosoma mansoni infection in Biomphalaria glabrata snails.

Schistosoma infection in Biomphalaria glabrata can be detected by either exposing snails to light to induce cercarial shedding or by squeezing them between glass slides to detect parasites in the digestive gland and other regions. The methods available are inefficient for identification of prepatent infections and do not allow the diagnosis of infection in snails that die before arriving in the laboratory. Furthermore, infection is undetectable after migration of sporocysts from the head-foot region of the snail. We examined the use of polymerase chain reaction (PCR) amplification of minisatellite repeats from Schistosoma mansoni mitochondrial DNA (mtDNA) to identify snail infection. We found that amplification of mtDNA under low stringency conditions (LS-PCR) allowed for the identification of specific S. mansoni infection in Biomphalaria snails. To confirm these results, specific amplification reactions were performed using 2 sets of primers that allowed for the diagnosis of infection and an internal control of the reaction (multiplex PCR). Results obtained using multiplex PCR demonstrated the ability of the assay to detect S. mansoni-specific infection. Thus, LS-PCR as well as specific multiplex PCR allow for the detection of prepatent infections and show high specificity for S. mansoni in comparison with other trematode infections in either living or dead snails.

Cytokine mRNA profile of peripheral blood mononuclear cells isolated from individuals with Trypanosoma cruzi chronic infection.

Characterization of immunologic activities during chronic infection with Trypanosoma cruzi is critical for understanding the dynamics of human Chagas' disease. Since cytokine production is mainly regulated by transcription and mRNA stability, quantitative RT-PCR analysis gives an accurate picture of the influences of disease on cytokine profile. Using RT-PCR, the authors analysed the levels of message expression for several cytokines in peripheral blood mononuclear cells (PBMC) freshly isolated from chagasic patients (CP) and non-infected individuals (NI), and in in vitro-stimulated PBMC from CP. Ex vivo analysis showed that mean levels of expression of IL-5, IL-10, IL-13 and IFN gamma were dramatically increased in PBMC from CP, compared to NI. The levels of IL-2 and IL-4 were not significantly different between groups. Analysis of cytokine mRNA production after in vitro culture with parasite-derived antigens (EPI or TRP) or anti-epimastigote antibodies (Id) showed that these two classes of stimuli induced distinct cytokine responses. While EPI or TRP induced higher production of IFN gamma specific message and low IL-10, anti-Id cells produced higher levels of IL-10 and low IFN gamma. The simultaneous presence of antigenic and antibody stimulation in the host during the chronic phase of Chagas' disease could explain the existence of both inflammatory and anti-inflammatory cellular reactivity detected in most patients.

Influence of parasite presence on the immunologic profile of peripheral blood mononuclear cells from chagasic patients after specific drug therapy.

The aim of this study is to evaluate the effects of parasite clearance on the immunological profile of peripheral blood mononuclear cells (PBMC) from chagasic patients submitted to specific drug therapy. PBMC were examined by flow cytometry and proliferative responsiveness to Trypanosoma cruzi-related stimuli. Three groups of patients were studied: not treated (NT), treated not cured (TNC) and cured (C). All data were compared to values from uninfected individuals (NI). NT displayed a lower percentage of CD3+ cells as compared to NI, while TNC and C had mean values that were between those from NI and NT. Infected patients had double the percent of CD3+ HLA-DR+ cells, independent of the efficacy of the treatment. Thus, absence of circulating parasites did not reduce T cell activation in Chagas' disease. NT displayed a higher percentage of CD5+ B cells as compared to NI, while TNC and C had mean values between those from NI and NT. In contrast to the phenotypic data, the in vitro mean proliferative responses to parasite-related stimuli of PBMC from C were reduced to the low mean levels observed in NI. These striking differences were statistically different from the high responses seen in NT and TNC. Our data suggest that proliferative responses of PBMC from C reflect immunological changes due elimination of parasite. However, successful treatment did not alter the levels of peripheral T cell activation.

Idiotypic/anti-idiotypic interactions in schistosomiasis and Chagas' disease.

Immunoaffinity-purified antibodies against soluble Schistosoma mansoni egg antigens (SEA) were isolated from the sera of patients with schistosomiasis mansoni. Similarly, antibodies against Trypanosoma cruzi epimastigote antigens were obtained from sera of patients with Chagas' disease. These antibody preparations were used in culture to demonstrate the presence of anti-idiotypic T lymphocytes in peripheral blood mononuclear cell preparations from patients with either schistosomiasis mansoni or Chagas' disease, or with both of these infections. Only cells from patients with schistosomiasis or both infections proliferated upon exposure to the anti-SEA antibodies. Conversely, only cells from patients with Chagas' disease or both infections responded to anti-epimastigote antibodies. Western blot analysis of SEA and epimastigote antigens, developed by patients' sera or by immunoaffinity-purified antibody preparations, substantiated that anti-SEA immunoaffinity-purified antibodies only reacted with components of SEA, and anti-epimastigote immunoaffinity-purified antibodies only reacted with components of epimastigote antigenic preparation. These studies demonstrate the presence of anti-idiotypic T lymphocytes in the peripheral blood of patients with schistosomiasis or Chagas' disease which are specific for idiotypes generated during these infections.

Schistosoma mansoni: phospholipid methylation and the escape of schistosomula from in vitro cytotoxic reaction.

The ability of Schistosoma mansoni schistosomula to evade in vitro cytotoxic activity of antibodies plus complement is shown to be increased by incubation with Concanavalin A (Con A) or with non-immune inactivated human serum. This effect was not observed if S-adenosyl-homocysteine (SAH) a methyltransferase inhibitor was added to the incubation medium. Methyl group incorporation occurs in schistosomulum phospholipids if parasites are incubated in Earle's balanced salt solution. This incorporation is increased by Con A addition and this increase is inhibited by SAH. Supernatants of schistosomula incubated in culture media containing Con A were able to promote phospholipid methylation, showing that methyltransferases were liberated into the culture media. The possible roles played by these phenomena in host-parasite interactions are discussed.