42 resultados para Citotoxidade de mediação celular Teses


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Oral squamous cell carcinoma (OSCC) is the most common malignancy in oral cavity and human papillomavirus (HPV) may have an important role in its development. The aim of this experiment was to investigate the HPV DNA and viral types in 90 cases of OSCC. Moreover, a comparative analysis between the cases of OSSC with and without HPV DNA was performed by using cell cycle markers p21 and pRb in order to detect a possible correlation of these proteins and HPV infection. DNA was extracted from paraffin embedded tissue and amplified by PCR (polymerase chain reaction) with primers PCO3+ e PCO4+ for a fragment of human β-globin gene. After this procedure, PCR for HPV DNA detection was realized using a pair of generic primers GP5+ e GP6+. Immunohistochemical study was performed by streptoavidin-biotin technique and antibodies against p21 and pRb proteins were employed. Eighty-eight cases were positive for human β-globin gene and HPV DNA was found in 26 (29.5%) of then. It could not be detected significant correlation between HPV and age, sex and anatomical sites of the lesion. The most prevalent viral type was HPV 18 (80.8%). Regarding the immunohistochemical analysis, it was detected significant association between HPV presence and pRb immunoexpression (p=0,044), nevertheless, the same was not observed in relation to p21 protein (p =0,416). It can be concluded that the low detection of HPV DNA in OSCC by the present experiment suggests a possible role of the virus in the development and progression in just a subset of this disease

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In rodents, the suprachiasmatic nucleus (SCN) and the intergeniculate leaflet (IGL) are the main components of the circadian system. The SCN is considerate the site of an endogenous biological clock because can to generate rhythm and to synchronize to the environmental cues (zeitgebers) and IGL has been related as one of the main areas that modulate the action of SCN. Both receive projections of ganglion cells of retina and this projection to SCN is called retinohypothalamic tract (RHT). Moreover, the IGL is connected with SCN through of geniculohypothalamic tract (GHT). In primates (include humans) was not still demonstrated the presence of a homologous structure to the IGL. It is believed that the pregeniculate nucleus (PGN) can be the answer, but nothing it was still proven. Trying to answer that question, the objective of our study is to do a comparative analysis among PGN and IGL through of techniques immunohystochemicals, neural tracers and FOS expression after dark pulses. For this, we used as experimental model a primate of the new world, the common marmoset (Callithrix jacchus). Ours results may contribute to the elucidation of this lacuna in the circadian system once that the IGL is responsible for the transmission of nonphotic information to SCN and participate in the integration between photic and nonphotic stimulus to adjust the function of the SCN. In this way to find a same structure in primates represent an important achieve in the understanding of the biological rhythms in those animals

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It s an application about the development of the family agriculture integrated to the market in which is detected the development of the relation of partnership between settled of agrarian reform and the capitalist enterprise. It s shown initially, a conceptual discussion about family agriculture, watching the historical contexts that characterize the expropriation and subordination of the category. This way, the family agriculture is contextual zed in the moment of the modernization of the agriculture, he rising of the social tension in the area of the restructuration of production and the globalization. Finding to understand the agrarian question in Rio Grande do Norte, it s characterized the acting of the state in promoting agrarian reform politics and redistribution of lands. This way, the research demonstrate the reality of the settled of Vale do Lrio, with the partnership of the Caliman Company S. A. in this context, it s emphasized the social geographic transformation in the settler. This way it was realized the analysis of the survey of data in a lot of public department, and the research of the area with use of application form, in 90% percent of the researched group, with interviewing with the leaders of this group and with the manager of the Company. The research demonstrates an analysis of the reality lived by this group, in the perspective the interests of the government and the capital.

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The Amazon holds over half of the planet's remaining tropical forests and comprises the largest biodiversity in the world, accounting for approximately 60 % of the Brazilian territory. However, deforestation fires in the region causes serious problems to exposed human. The aim of this study was to evaluate the chemical compounds as well as the cellular and molecular effects after exposure to organic material extracted from particulate matter less than 10 m (PM10) in the Amazon region. As for the chemical composition, n-alkanes analysis showed a prevalence of anthropogenic influence during the fires in the region. In addition, there was a predominance of monosaccharides from biomass burning markers. Also, the Polycyclic Aromatic Hydrocarbons (PAH) and their derivatives have also been identified in samples collected in the Amazon. By using the PAH concentrations was possible to calculate the BaP-equivalent and it was found that the dibenz(a) anthracene contributes with 83% to potential carcinogenic risk. As for the potential mutagenic risk, the benzo (a) pyrene is the HPA that has a major contribution in this analysis. It may be noted that the retene was the most abundant PAH. This compound was genotoxic and cause death by necrosis in the human lung cells. In biological tests, the data showed that organic PM10 is capable of causing genetic damage in both plant cells and in human lung cells. This damage cause an arrest in the G1 phase of the cell cycle exposed, increasing the expression of p53 and p21. Additionally, the PM10 caused cell death by apoptosis, increasing the foci of histone - H2AX. Given these results, it is important to emphasize the reduction and better control of biomass burning in the Amazon region thus improving the quality of health of the population being exposed. As clearly stated recently by the World Health Organization, the reduction of air pollution could save millions of lives annually.

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This research aims to make a reflective analysis about the academic production originated in the stricto sensu post graduation programs in the country, produced in the period of 1990 to 2010, in the field of History of Mathematics, especifically on works about the History of Mathematics in Mathematics education and that present pedagogical proposals that make use of the History of Mathematics in order to teach Mathematics. Defending the thesis that the researches on mathematics education with goals turned to the use of didactic proposals related to the history of mathematic that take in consideration the coherency between epistemological aspects inherent to mathematics history and anthological elements materialized on the conceptions of mathematics and mathematics history and of apprenticeship (implicitly or explicitly exposed) may originate significant contribution to the field of history of mathematics on education. Among these, nine were Masters Degree dissertations and five PHDs theses. The reflective analysis was accomplished from two matrixes; one from theoretical nature and the other, ontologic nature, elaborated from the pretexts of Sanches Gamboa, about the epistemological analysis from academic production in the field of Mathematics Education and the following theoretical perspectives in the field of History of Mathematics Education, that are: linear evolutionary theory, structural construtivist operative, evolutionary discontinuous, historical and socialcultural investigation and the use of activities estimulating the usage of verbal and nonverbal expressions. These perspectives were based on the works of Miguel and Miorim, Mendes and Radford. As results, we have detected some established dissonances between the categories related to theoretical and ontologic levels and the pedagogical proposal presented in these researches. On the other hand, we have discovered works that are able to establish consonances between the theoretical and ontological elements and the presented pedagogical proposal. These works carry significative contributions to the field of History of Mathematics applied to Mathematics pedagogical practice, inclusively presenting significative theoretical elements to the production of knowledge recognized as scientific in the Mathematics field

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This work aims at studying the biographical mediation taken as the progress of people in formation process who develop a biographical work on their own experiences with the help of a former (PASSEGGI, 2006, 2011). The research was carried out on a curricular component from Curso de Formao Inicial e Continuada (initial and continuous process of formation of teachers) with teachers from public schools developed by Instituto Federal de Educao do Rio Grande do Norte (IFRN/ Ipanguau). The target audience featured diversity of professionals and experiences of formation. The general objective studied the potentials of procedures and devices used to mediate the reflection about the necessary knowledge to teaching practice based on their own experiences (auto-biographical) and the experience from the others (hetero-biographical). The study tried to respond to the following questions: how do teachers in formation relate themselves to the knowledge from experience? What procedures and devices contribute on the teachers formation on the three different dimensions of biographical mediation (initiatory, maieutic, hermeneutics)? How to provide the auto-formation and hetero-formation? The theories and methods of this work are based on studies and researches that place the person in formation in the center of investigation and formation and analyze their reflective, re-inventive and self-re-inventive capacity. (FREIRE, 1987, 1996, 2001, 2011; JOSSO, 2008, 2010, 2012; DELORY-MONBERGER, 2006, 2008, 2012; CHARLLOT, 2000; CATANI, 2001; PASSEGGI, 2008; 2010; 2011; 2012). We selected six teachers who participate entirely on the meetings of the program. They discussed on the study topics, shared narrations that integrate their formation and the themes related to the course. The empirical material is composed by the narrations of the six participants and hearing boards done by themselves at the moment of the narration sharing process. The analysis followed three steps: a) the path of the program and the procedures of biographical mediation; b) the relations former/teacher on the three dimensions of biographical mediation; c) the hearing board as a device of biographical mediation. We concluded that the procedures and devices used for biographical mediation made possible specific learnings that are sources for the practice of initial and continuous teachers formation, as well as for the formation of the former-researcher about the work with autobiographical narrations. Thus, it allow the co-investment of participants into the process of auto-formation and hetero-formation.

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Base excision repair (BER) proteins has been associated with functions beyond DNA repair. Apurynic/apyrimidinic endonuclease 1 (APE1) is a multifunctional protein involved in a plethora of cellular activities, such as redox activation of transcription factors, RNA processing and DNA repair. Some studies have described the action of the protein 8-oxoguanine (OGG1) in correcting oxidized lesions in promoters as a step in the transcription of pro-inflammatory cytokines. Despite being especially important in redox activation of transcription factors such as nuclear factor B (NF-B) and AP- 1, the repair activity of APE1 has not yet been associated with the inflammatory response. In this study, experimental and bioinformatic analysis approaches have been used to investigate the relationship between inhibition of the repair of abasic sites in DNA by MX, a synthetic molecule designed to inhibt the repair activity of APE1, and the modulation of the inflammatory response. The results showed that treatment of monocytes with lipopolysaccharide (LPS) and MX reduced the expression of cytokines, chemokines and toll-like receptors, and negatively regulated biological immune processes, as macrophages activation, and NF-B and tumor necrosis factor (TNF-) and interferon pathways, without inducing cell death. The transcriptomic analysis suggests that LPS/MX treatment induces mitochondrial dysfunction, endoplasmic reticulum stress and activation of autophagy pathways, probably activated by impairment of cellular energy and/or the accumulation of nuclear and mitochondria DNA damage. Additionally, it is proposed that the repair activity of APE1 is required for transcription of inflammatory genes by interaction with abasic sites at specific promoters and recruitment of transcriptional complexes during inflammatory signaling. This work presents a new perspective on the interactions between the BER activity and the modulation of inflammatory response, and suggests a new activity for APE1 protein as modulator of the immune response in a redox-independent manner.

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This doctoral dissertationproposes the description, interpretation and analysis of the compositional structure of thesis and dissertation abstracts, with regard to the linguistic mechanisms that evidence text zones of different typological sequences, such as those of the text plan. Along these lines, the research problem was developed from the notion of compositional structure (sequences and text plans), as one of the levels or plans of text analysis, according to the theoretical framework proposed by Jean-Michel Adam (2011a). The main objective of this study was to recognize how the compositional structure, of thesis and dissertation abstracts, is achieved, with respect to text units and the global organization of this text category. The hypothesis posed in this research posits that specific informational text composition categories of abstracts are necessary to process the representation of the original text and the way in which it makes its meaning. Subsequently, this study is based on the theoretical and methodological framework of Text Linguistics (TL) and, above all, Textual Discourse Analysis (TDA), as we endeavor to understand the organizational structure of abstracts from both a linguistic and textual perspective. This structure involves the text plan of abstracts, with respect to their communicative purpose, i.e, the sharing of scientific information in its standard textual form. Thus, the development of this study, from a theoretical and methodological perspective, is based on the theoretical and descriptive premises from TDA (ADAM, 2011a, 2012; PASSEGGI et al., 2010), and also from TL (BEAUGRANDE; DRESSLER, (2012 [1981]); COSERIU; LAMAS (2010); MARCUSCHI, 2009 [1983]; FVERO; KOCH, 1994;KOCH, 2006; BENTES, 2004; BENTES; LEITE, 2010), within the field of text studies. The methodology of this study relies on empirical, documental research, which is qualitative, and adopts a descriptive and interpretive approach. From the empirical perspective, our objective is to understand the problems pertaining to the textual composition of abstracts, aiming to elucidate them in light of the theoretical and methodological framework previously mentioned. The corpus of the analysis is comprised of seven abstracts designated for systematic data collection. These texts, written between 2004 and 2011,were selected from Masters theses and Doctoral dissertations in their electronic version, from the graduate program at the Federal University of Rio Grande do Norte. A thorough review of the literature reveals a clear fluctuation in the terminology of the concept, abstract. The results of the analysis revealed that the abstracts, which comprise the corpus of analysis in this study, in general, present typological heterogeneity, while the text plan remains fixed. Finally, the new knowledge gained in this research contributes both to the understanding of the compositional structure of abstracts as well as their production.

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Textual composition in classroom has been object of research in language studies along this last three decades in Brazil. This thematic recurrence occurs is a demonstration of the gap between writing skill teaching and learners performance. In this research, we argue that during writing process in classroom, teachers mediated actions guide students to the exotopic exercise on their texts, facing it as a fundamental phase of their composition, with meaningful effect for the development of textual authorship. In this sense, we have chosen as investigation focus the textual composition of Letters Students at Universidade do Estado do Rio Grande do Norte UERN - to study writing processual characteristics, based on teachers mediation. The main aim of this research is to analyze students (re)writing along Letters Course, to comprehend the process of authorship construction in their texts and the effects resulted through teacher mediation in this process. More specifically, a) to analyze teacher mediation as a mechanism for authorship development in texts composed by Letters Students; b) to deduce, based on different versions of textual composition, the effects of teacher mediation on students writing; and c) to describe compositional textual process in classroom, identifying students attitudes/behaviors before writing task. We have brought several voices into the dialogue, among them we highlight those based on bakhtinian studies. Some of those authors are related to Bakhtin circle, by themselves (BAKHTIN/VOLOCHINOV, [1929] 2006; BAKHTIN, [1979] 2003; [1963] 2008; [1975] 2010a; [1986] 2010b), their debaters (FARACO, 2008, 2009a, 2009b, 2010; PONZIO, 2010, 2012; GERALDI, 2010a; 2010b OLIVEIRA, 2006, 2008a, 2008b, 2010, among others), to guide us, mainly, on dialogism, author and authorship, and their conceptual implications: exotopy, finishing, esthetic activity, and ethical act. Data was constituted in teaching situation, involving teacher/researcher and 5th Term Letters/UERN students. Therefore, we have submitted an open questionnaire, textual discussion, and an article (re)writing. Data analysis has revealed subjects little experience with writing composition in the Course, as a systematic practice, in their routine, dialogued, whose social function is explored. The texts are generally written in a single version and useful only to receive a score. Data analysis show insecure students in relation the writing, and with many difficulties to do it. On the other hand, writing movements, on the analyzed articles, have revealed that the subjects show a responsive attitude in relation to the mediated activities, to respond rewriting proposal. Despite some problems remain unsolved and many others emerge in each version of the article, in general, we consider that teacher mediation had a positive effect on student writing, considering that it boosted the author exotopic movement, something indispensable to compose a text. The three interventions carried out, in some way, provided opportunity for the subjects to modify their article.

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Textual composition in classroom has been object of research in language studies along this last three decades in Brazil. This thematic recurrence occurs is a demonstration of the gap between writing skill teaching and learners performance. In this research, we argue that during writing process in classroom, teachers mediated actions guide students to the exotopic exercise on their texts, facing it as a fundamental phase of their composition, with meaningful effect for the development of textual authorship. In this sense, we have chosen as investigation focus the textual composition of Letters Students at Universidade do Estado do Rio Grande do Norte UERN - to study writing processual characteristics, based on teachers mediation. The main aim of this research is to analyze students (re)writing along Letters Course, to comprehend the process of authorship construction in their texts and the effects resulted through teacher mediation in this process. More specifically, a) to analyze teacher mediation as a mechanism for authorship development in texts composed by Letters Students; b) to deduce, based on different versions of textual composition, the effects of teacher mediation on students writing; and c) to describe compositional textual process in classroom, identifying students attitudes/behaviors before writing task. We have brought several voices into the dialogue, among them we highlight those based on bakhtinian studies. Some of those authors are related to Bakhtin circle, by themselves (BAKHTIN/VOLOCHINOV, [1929] 2006; BAKHTIN, [1979] 2003; [1963] 2008; [1975] 2010a; [1986] 2010b), their debaters (FARACO, 2008, 2009a, 2009b, 2010; PONZIO, 2010, 2012; GERALDI, 2010a; 2010b OLIVEIRA, 2006, 2008a, 2008b, 2010, among others), to guide us, mainly, on dialogism, author and authorship, and their conceptual implications: exotopy, finishing, esthetic activity, and ethical act. Data was constituted in teaching situation, involving teacher/researcher and 5th Term Letters/UERN students. Therefore, we have submitted an open questionnaire, textual discussion, and an article (re)writing. Data analysis has revealed subjects little experience with writing composition in the Course, as a systematic practice, in their routine, dialogued, whose social function is explored. The texts are generally written in a single version and useful only to receive a score. Data analysis show insecure students in relation the writing, and with many difficulties to do it. On the other hand, writing movements, on the analyzed articles, have revealed that the subjects show a responsive attitude in relation to the mediated activities, to respond rewriting proposal. Despite some problems remain unsolved and many others emerge in each version of the article, in general, we consider that teacher mediation had a positive effect on student writing, considering that it boosted the author exotopic movement, something indispensable to compose a text. The three interventions carried out, in some way, provided opportunity for the subjects to modify their article.

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INTRODUCTION AND OBJECTIVE: The study of biological behavior of odontogenic lesions is essential to the establishment of appropriate therapeutic approach and prognosis. The production of extracellular matrix metalloproteinases (MMPs), angiogenesis and cell proliferation contribute to tumor growth. This paper aims to review the literature on odontogenic tumors (OT) selected according to the new World Health Organization classification (WHO- 2005) by evaluating the expression of MMPs, angiogenic and cell proliferation. Furthermore, it aims to verify the relation between these markers and the biological behavior of these lesions. RESULTS: it was found that MMPs -1, -2, -7, -9 and -26 had a higher expression in both epithelial component and stroma, and 13 particularly in the stroma. Increased angiogenesis was observed in more aggressive OT. CD105 expression was higher in keratocystic odontogenic tumour (KOT) and CD34 in solid ameloblastomas (SA). It was observed a higher expression of Ki-67 and p53 in SA and KOT and a low cell proliferation rate in the adenomatoid odontogenic tumour (AOT). CONCLUSION: These results show that MMPs are involved in invasion and recurrence of some odontogenic lesions and are associated with the biological behavior of these tumors. Angiogenesis is critical to provide support to cell proliferation and these concomitant events are correlated with different levels of biological behavior in OT when compared to odontogenic cysts, hence the use of angiogenic inhibitors may be a potential therapeutic approach in these lesions.

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INTRODUCTION AND OBJECTIVE: The study of biological behavior of odontogenic lesions is essential to the establishment of appropriate therapeutic approach and prognosis. The production of extracellular matrix metalloproteinases (MMPs), angiogenesis and cell proliferation contribute to tumor growth. This paper aims to review the literature on odontogenic tumors (OT) selected according to the new World Health Organization classification (WHO- 2005) by evaluating the expression of MMPs, angiogenic and cell proliferation. Furthermore, it aims to verify the relation between these markers and the biological behavior of these lesions. RESULTS: it was found that MMPs -1, -2, -7, -9 and -26 had a higher expression in both epithelial component and stroma, and 13 particularly in the stroma. Increased angiogenesis was observed in more aggressive OT. CD105 expression was higher in keratocystic odontogenic tumour (KOT) and CD34 in solid ameloblastomas (SA). It was observed a higher expression of Ki-67 and p53 in SA and KOT and a low cell proliferation rate in the adenomatoid odontogenic tumour (AOT). CONCLUSION: These results show that MMPs are involved in invasion and recurrence of some odontogenic lesions and are associated with the biological behavior of these tumors. Angiogenesis is critical to provide support to cell proliferation and these concomitant events are correlated with different levels of biological behavior in OT when compared to odontogenic cysts, hence the use of angiogenic inhibitors may be a potential therapeutic approach in these lesions.