RESUMO
O estudo teve por objetivo conhecer a visão e a prática de professores de ciências e alunos de curso de licenciatura em Ciências Biológicas em relação aos distúrbios de aprendizagem e ao fracasso escolar, de modo a compreender os sentidos e significados construídos por eles em relação à crescente atribuição de responsabilidade biológica ao suposto fracasso no ensino. Trata-se de pesquisa qualitativa, que se utilizou de aplicação de questionário e entrevista semiestruturada com professores de escolas pública e particular e com alunos de um curso de graduação/licenciatura de uma universidade pública. Como resultados, é possível identificar a sobreposição em relação ao entendimento e uso de terminologias como "distúrbios", "problemas" e "dificuldades" de aprendizagem, sendo utilizadas pelos professores e estudantes participantes da pesquisa, como sinônimos para designar um processo análogo. Verificou-se a atribuição de causa biológica a qualquer dificuldade ou problema de aprendizado do aluno, ainda que a causa seja, de fato, devido a fatores sociais ou psicológicos. Evidenciou-se o despreparo para com a realização do diagnóstico, bem como desconhecimento em relação às formas de se fazer, atribuindo esse papel a outros profissionais que acreditam estar mais preparados para lidar com esses casos, considerando-se que o tratamento medicamentoso possa ser o mais efetivo. Desse modo, os resultados obtidos demonstram a importância de investigações e elucidações mais profundas a respeito do cotidiano escolar no que se refere às questões atreladas ao processo ensino-aprendizagem e à crescente medicalização de crianças e adolescentes.
The purpose of this study was to understand the vision and practice of science teachers and students of a licentiate degree course in Biological Sciences in relation to learning disorders and school failure, in order to understand the senses and meanings they constructed in relation to the increasing attribution of biological responsibility to the supposed school failure. It is a qualitative research, in which was used a questionnaire application and a semi-structured interview with public and private school teachers and with students of a undergraduate/licentiate course from a public university. As results it is possible to identify the overlap in terms of understanding and use of terminologies such as "disturbs", "problems" and "difficulties" of learning, by teachers and students participating in the research, as synonyms to designate the same process. The attribution of biological cause to any difficulty or learning problem of the student has been verified, even if the cause is, in fact, due to social or psychological factors. The lack of preparation for diagnosis was evidenciated, as well as lack of knowledge about the ways of doing it, attributing this role to other professionals who believe that they are better prepared to assist these cases, considering that drug treatment may be the most effective. Thus, the results obtained demonstrate the importance of investigations and more profound elucidations about the school daily life in relation to the issues linked with the teaching-learning process and the increasing medicalization of children and adolescents.
El estudio tuvo como objetivo conocer la visión y la práctica de los profesores de ciencias y los estudiantes de la licenciatura en Ciencias Biológicas en relación a los trastornos de aprendizaje y fracaso escolar, con el fin de comprender los significados construidos por ellos en relación al crecente aumento de la asignación de la responsabilidad biológica al supuesto fracaso en la enseñanza. Se trata de una investigación cualitativa, en la cual se utilizo la aplicación de cuestionarios y entrevistas semiestructuradas a maestros de escuelas públicas y privadas y a estudiantes en un curso de grado / licenciatura de una universidad pública. Como resultado, es posible identificar la superposición en relación con la comprensión y el uso de terminología como "trastornos", "problemas" y "dificultades" de aprendizaje, siendo utilizados por los profesores y estudiantes que participaron de la encuesta, indistintamente para describir un mismo proceso. Se encontró la asignación de causa biológica a cualquier dificultad o problema de aprendizaje de los estudiantes, aun que la causa sea de hecho, debido a factores sociales o psicológicos. La falta de preparación para realización de diagnóstico se hizo evidente, así como el desconocimiento de formas de hacer, asignando ese papel a otros profesionales que creen estar mejor preparados para hacer frente a estos casos, teniendo en cuenta que el tratamiento farmacológico puede ser más eficaz. Por lo tanto, los resultados demuestran la importancia investigaciones y mejores esclarecimiento sobre el cotidiano de la escuela cuando se trata de cuestiones relacionadas al proceso de enseñanza-aprendizaje y la creciente medicalización de niños y adolescentes.
Assuntos
Estudantes , Disciplinas das Ciências Biológicas , Medicalização , Professores Escolares , Fracasso Acadêmico , Fatores Sociais , Aprendizagem , Deficiências da Aprendizagem , Ensino , Tratamento Farmacológico , DocentesRESUMO
Cytokinesis is the last stage in the cell cycle. In prokaryotes, the protein FtsZ guides cell constriction by assembling into a contractile ring-shaped structure termed the Z-ring. Constriction of the Z-ring is driven by the GTPase activity of FtsZ that overcomes the energetic barrier between two protein conformations having different propensities to assemble into polymers. FtsZ is found in psychrophilic, mesophilic and thermophilic organisms thereby functioning at temperatures ranging from subzero to >100°C. To gain insight into the functional adaptations enabling assembly of FtsZ in distinct environmental conditions, we analyzed the energetics of FtsZ function from mesophilic Escherichia coli in comparison with FtsZ from thermophilic Methanocaldococcus jannaschii. Presumably, the assembly may be similarly modulated by temperature for both FtsZ orthologs. The temperature dependence of the first-order rates of nucleotide hydrolysis and of polymer disassembly, indicated an entropy-driven destabilization of the FtsZ-GTP intermediate. This destabilization was true for both mesophilic and thermophilic FtsZ, reflecting a conserved mechanism of disassembly. From the temperature dependence of the critical concentrations for polymerization, we detected a change of opposite sign in the heat capacity, that was partially explained by the specific changes in the solvent-accessible surface area between the free and polymerized states of FtsZ. At the physiological temperature, the assembly of both FtsZ orthologs was found to be driven by a small positive entropy. In contrast, the assembly occurred with a negative enthalpy for mesophilic FtsZ and with a positive enthalpy for thermophilic FtsZ. Notably, the assembly of both FtsZ orthologs is characterized by a critical concentration of similar value (1-2 µM) at the environmental temperatures of their host organisms. These findings suggest a simple but robust mechanism of adaptation of FtsZ, previously shown for eukaryotic tubulin, by adjustment of the critical concentration for polymerization.
Assuntos
Proteínas Arqueais/metabolismo , Methanocaldococcus/metabolismo , Biopolímeros/metabolismo , Escherichia coli/genética , Guanosina Trifosfato/metabolismo , Hidrólise , Cinética , Methanocaldococcus/genética , Polimerização , Temperatura , TermodinâmicaRESUMO
The induction of donor-specific transplant tolerance is one of the main goals of modern immunology. Establishment of a mixed chimerism state in the transplant recipient has proven to be a suitable strategy for the induction of long-term allograft tolerance; however, current experimental recipient preconditioning protocols have many side effects, and are not feasible for use in future therapies. In order to improve the current mixed chimerism induction protocols, we developed a non-myeloablative bone-marrow transplant (NM-BMT) protocol using retinoic acid (RA)-induced alloantigen-specific Tregs, clinically available immunosuppressive drugs, and lower doses of irradiation. We demonstrate that RA-induced alloantigen-specific Tregs in addition to a NM-BMT protocol generates stable mixed chimerism and induces tolerance to allogeneic secondary skin allografts in mice. Therefore, the establishment of mixed chimerism through the use of donor-specific Tregs rather than non-specific immunosuppression could have a potential use in organ transplantation.
RESUMO
Introducción: el dolor crónico es una condición que afecta a 1 de cada 5 personas en el mundo, comprometiendo diferentes áreas de la calidad de vida. El cuestionario para graduación de dolor crónico (CGDC) fue desarrollado como una forma de evaluar y monitorear a estos pacientes, con altos niveles de fiabilidad y validez. Objetivos: Desarrollar una versión española del CGDC, adaptado culturalmente a Chile y determinar su validez y fiabilidad, en el Hospital Clínico de la Universidad de Chile. Material y métodos: El cuestionario fue traducido y adaptado culturalmente de acuerdo a las recomendaciones internacionales. Se aplicó SF-36 v2.0 en 130 pacientes condolor musculoesquelético crónico (más de 6 meses). La fiabilidad se calculó con Alfa de Cronbach y el índice de validez se evaluó mediante la comparación de las respuestas de la CGDC para cada categoría con las subescalas del SF-36 v.2. Resultados: La versión chilena de la CGDC fue válida. Se obtuvieron altos niveles de confiabilidad con alfa de Cronbach> 0,7. Se observaron correlaciones significativas del SF -36,especialmente con las subescalas que tienen alta capacidad de medir el dolor y la salud física (p <0,01). Conclusiones: Los resultados presentados aquí confirman la fiabilidad y validez de la versión chilena del CGDC en la evaluación de pacientes con dolor musculoesquelético crónico.
Introduction: chronic pain is a condition that affectss 1 in every 5 people in the world, compromising different areas of quality of life. The Chronic Pain Graded questionnaire (CPG) was developed as a form to assess and monitor these patients, with high levels of reliability and validity. Objectives: To develop a spanish version of the chronic pain graded questionnaire, culturally adapted to Chile determine its reliability and convergent construct validity , in the University of Chile Clinical Hospital. Materials and Methods: The chronic pain graded questionnaire was translated and culturally adapted accordingt o international recommendations. It was applied with SF -36 v2.0 questionnaire in 130 patients with chronic musculoskeletal pain (more than 6 months). The reliability was calculated with de Alpha the Cronbach Index and de validity was assessed by comparing the responses of the CPG for each category with the subscales of SF-36 v.2. Results: The Chilean version of the CBDC was valid. High levels of reliability was obtained with Cronbachs alpha > 0.7. Compared with the SF -36 significant correlations were observed, especially with the SF -36 subscales having high ability to measure pain and physical health ( P < 0.01). Conclusions: The results presented here confirm the reliability and validity of the Chilean version of the chronic pain graded questionnaire in the evaluation of patients with chronic musculoskeletal pain.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Doenças Musculoesqueléticas/complicações , Dor Musculoesquelética/diagnóstico , Medição da Dor/instrumentação , Inquéritos e Questionários , Chile , Doença Crônica , Reprodutibilidade dos Testes , Autorrelato , TraduçõesRESUMO
BACKGROUND: DNA methylation is the most important epigenetic change involved in the control of gene expression in human cells. Methylation of the p16(INK4a) gene occurs early in the development of cervical cancer. Low-grade squamous intraepithelial lesions (LSILs) are prevalent, and their behavior is variable. OBJECTIVE: To identify the HPV DNA type, detect the methylation status of the p16(INK4A) gene, and analyze their association with the cytological evolution of LSIL over a period of two years. METHODS: We conducted a cohort study with 40 participants. Cervical scrapings were collected for cytological and molecular analysis. HPV DNA detection and typing were performed by means of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Methylation-specific PCR was performed to detect methylation. RESULTS: HPV DNA was detected in 87% of the cases, and type 16 was the most frequent type. Methylation was detected in 11% of the cases and did not exhibit a significant correlation with the HPV type. Unfavorable cytological evolution exhibited a significant association with the presence of methylation. CONCLUSION: HPV 16 was the most frequently detected type of HPV in LSIL. Methylation of the p16(INK4A) gene was infrequent and occurred independent of the presence of HPV DNA. Methylation of the p16(INK4a) gene exhibited a significant correlation with persistence/progression of LSIL.
Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA/genética , Papillomavirus Humano 16/genética , Lesões Intraepiteliais Escamosas Cervicais/genética , Displasia do Colo do Útero/genética , Adulto , Biomarcadores Tumorais , Estudos de Coortes , DNA Viral/genética , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Papillomavirus/diagnóstico , Lesões Intraepiteliais Escamosas Cervicais/virologia , Adulto Jovem , Displasia do Colo do Útero/virologiaRESUMO
CD4(+) CD25(+) Foxp3(+) regulatory T (Treg) cells mediate immunological self-tolerance and suppress immune responses. Retinoic acid (RA), a natural metabolite of vitamin A, has been reported to enhance the differentiation of Treg cells in the presence of TGF-ß. In this study, we show that the co-culture of naive T cells from C57BL/6 mice with allogeneic antigen-presenting cells (APCs) from BALB/c mice in the presence of TGF-ß, RA, and IL-2 resulted in a striking enrichment of Foxp3(+) T cells. These RA in vitro-induced regulatory T (RA-iTreg) cells did not secrete Th1-, Th2-, or Th17-related cytokines, showed a nonbiased homing potential, and expressed several cell surface molecules related to Treg-cell suppressive potential. Accordingly, these RA-iTreg cells suppressed T-cell proliferation and inhibited cytokine production by T cells in in vitro assays. Moreover, following adoptive transfer, RA-iTreg cells maintained Foxp3 expression and their suppressive capacity. Finally, RA-iTreg cells showed alloantigen-specific immunosuppressive capacity in a skin allograft model in immunodeficient mice. Altogether, these data indicate that functional and stable allogeneic-specific Treg cells may be generated using TGF-ß, RA, and IL-2. Thus, RA-iTreg cells may have a potential use in the development of more effective cellular therapies in clinical transplantation.
Assuntos
Rejeição de Enxerto/prevenção & controle , Transplante de Pele , Pele/imunologia , Linfócitos T Reguladores/imunologia , Tretinoína/farmacologia , Transferência Adotiva , Aloenxertos , Animais , Técnicas de Cocultura , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Expressão Gênica , Sobrevivência de Enxerto , Interleucina-2/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/administração & dosagem , Pele/citologia , Baço/citologia , Baço/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/transplante , Fator de Crescimento Transformador beta/farmacologiaRESUMO
The aim of this study was to assess whether α-tocopherol administration prevented alterations in the ectonucleotidase activities and platelet aggregation induced by high-fat diet in rats. Thus, we examined four groups of male rats which received standard diet, high-fat diet (HFD), α-tocopherol (α-Toc), and high-fat diet plus α-tocopherol. HFD was administered ad libitum and α-Toc by gavage using a dose of 50 mg/kg. After 3 months of treatment, animals were submitted to euthanasia, and blood samples were collected for biochemical assays. Results demonstrate that NTPDase, ectonucleotide pyrophosphatase/phosphodiesterase, and 5'-nucleotidase activities were significantly decreased in platelets of HFD group, while that adenosine deaminase (ADA) activity was significantly increased in this group in comparison to the other groups (P < 0.05). When rats that received HFD were treated with α-Toc, the activities of these enzymes were similar to the control, but ADA activity was significantly increased in relation to the control and α-Toc group (P < 0.05). HFD group showed an increased in platelet aggregation in comparison to the other groups, and treatment with α-Toc significantly reduced platelet aggregation in this group. These findings demonstrated that HFD alters platelet aggregation and purinergic signaling in the platelets and that treatment with α-Toc was capable of modulating the adenine nucleotide hydrolysis in this experimental condition.
Assuntos
Dieta Hiperlipídica , Nucleotídeos/metabolismo , Agregação Plaquetária , alfa-Tocoferol/farmacologia , Animais , RatosRESUMO
One of the greatest advances in medicine during the past century is the introduction of organ transplantation. This therapeutic strategy designed to treat organ failure and organ dysfunction allows to prolong the survival of many patients that are faced with no other treatment option. Today, organ transplantation between genetically dissimilar individuals (allogeneic grafting) is a procedure widely used as a therapeutic alternative in cases of organ failure, hematological disease treatment, and some malignancies. Despite the potential of organ transplantation, the administration of immunosuppressive drugs required for allograft acceptance induces severe immunosuppression in transplanted patients, which leads to serious side effects such as infection with opportunistic pathogens and the occurrence of neoplasias, in addition to the known intrinsic toxicity of these drugs. To solve this setback in allotransplantation, researchers have focused on manipulating the immune response in order to create a state of tolerance rather than unspecific immunosuppression. Here, we describe the different treatments and some of the novel immunotherapeutic strategies undertaken to induce transplantation tolerance.
Assuntos
Rejeição de Enxerto/prevenção & controle , Fatores Imunológicos/uso terapêutico , Transplante de Órgãos , Tolerância ao Transplante/efeitos dos fármacos , Citocinas/biossíntese , Citocinas/imunologia , Células Dendríticas/imunologia , Células Dendríticas/patologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/efeitos dos fármacos , Sobrevivência de Enxerto/imunologia , Humanos , Terapia de Imunossupressão , Imunossupressores/efeitos adversos , Macrófagos/imunologia , Macrófagos/patologia , Linfócitos T/imunologia , Linfócitos T/patologia , Transplante HomólogoRESUMO
The relation between adenine nucleotides and cancer has already been described in literature. Considering that the enzymes ectonucleotide pyrophosphatase/phosphodiesterase (E-NPP) and adenosine deaminase (ADA) act together to control nucleotide levels, we aimed to investigate the role of these enzymes in prostate cancer (PCa). E-NPP and ADA activities were determined in serum and platelets of PCa patients and controls. We also verified the influence of the Gleason score, bone metastasis and treatment in the enzyme activities. Platelets and serum E-NPP activity increased, whereas ADA activity in serum decreased in PCa patients. In addition, Gleason score, metastasis and treatment influenced E-NPP and ADA activities. We may propose that E-NPP and ADA are involved in the development of PCa. Moreover, E-NPP and ADA activities are modified in PCa patients with distinct Gleason score, with bone metastasis, as well as in patients under treatment.
Assuntos
Adenosina Desaminase/metabolismo , Neoplasias Ósseas/enzimologia , Neoplasias Ósseas/patologia , Diester Fosfórico Hidrolases/metabolismo , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia , Pirofosfatases/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/secundário , Neoplasias Ósseas/terapia , Regulação para Baixo/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Diester Fosfórico Hidrolases/sangue , Neoplasias da Próstata/terapia , Pirofosfatases/sangue , Resultado do TratamentoRESUMO
T helper type 17 (Th17) lymphocytes are found in high frequency in tumour-burdened animals and cancer patients. These lymphocytes, characterized by the production of interleukin-17 and other pro-inflammatory cytokines, have a well-defined role in the development of inflammatory and autoimmune pathologies; however, their function in tumour immunity is less clear. We explored possible opposing anti-tumour and tumour-promoting functions of Th17 cells by evaluating tumour growth and the ability to promote tumour infiltration of myeloid-derived suppressor cells (MDSC), regulatory T cells and CD4(+) interferon-γ(+) cells in a retinoic acid-like orphan receptor γt (RORγt) -deficient mouse model. A reduced percentage of Th17 cells in the tumour microenvironment in RORγt-deficient mice led to enhanced tumour growth, that could be reverted by adoptive transfer of Th17 cells. Differences in tumour growth were not associated with changes in the accumulation or suppressive function of MDSC and regulatory T cells but were related to a decrease in the proportion of CD4(+) T cells in the tumour. Our results suggest that Th17 cells do not affect the recruitment of immunosuppressive populations but favour the recruitment of effector Th1 cells to the tumour, thereby promoting anti-tumour responses.