122 resultados para Desenvolvimento da expressão oral


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DNA repair systems play a critical role in protecting the human genome from damage caused by carcinogens present in the environment. Mutations in DNA repair genes may be responsible for tumor development and resistance of malignant cells to chemotherapeutic agents. The major pathway for oxidative DNA damage repair is the base excision repair pathway. The objective of this study was to investigate the immunoexpression of APE-1 and XRCC-1, which are proteins involved in DNA base excision repair and its association with clinical and histopathological parameters in oral tongue squamous cell carcinoma (OTSCC), in order to investigate a possible prognostic value for those proteins. The expression of APE-1 and XRCC-1 was evaluated semi-quantitatively by immunohistochemistry in 50 OTSCC cases. Clinical data was collected from patients’ medical charts and histopathological grading was performed for each case. Statistical analysis (Chi-square and Fisher’s exact tests; significance of 5%) was performed to determine the association between protein expressions and clinico-pathological characteristics. APE-1 was highly expressed in nucleus and cytoplasm in 56% of cases. XRCC-1 showed overexpression only in nucleus in 60% of cases. High expression of XRCC-1 was significantly associated to clinical stages I and II (P=0.02). Both proteins were not associated to other clinical parameters or histopathological grading. Our findings demonstrate that DNA base excision repair proteins APE-1 and XRCC-1 are upregulated in OTSCC, however, they are not related to clinical and histologic parameters, except for XRCC-1 association to better clinical staging. Our results indicate that the immunohistochemical expression of these proteins has no association with prognostic parameters in this tumor.

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Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.

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Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.

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Squamous cell carcinoma (SCC ) is the most common malignancy of the oral cavity (OSCC), with a high mortality rate. Due to this, the discovery of biomarkers that facilitate the understanding of the biological behavior of the tumor and improve treatment is necessary. Urokinase type plasminogen activator (uPA) and its receptor, uPAR, are responsible for the proteolysis of structures of the basement membrana and extracellular matrix, facilitating tumor invasion. This study aims to assess the immuno expression of these proteins in 46 cases of squamous cell carcinoma of the oral tongue (OTSCC). These results were related to the presence of metastasis, clinical TNM staging, locoregional recurrence, outcome of the lesion and histological grading. Immunostaining of each case was evaluated semiquantitatively, in the front of invasion and center of the tumor, in which scores were assigned: 0 (0% of positive cells), 1 (1-10% of positive cells), 2 (11 -50% positive cells) and 3 (more than 50% positive cells). The expression of uPA was observed in 93.5% (n=43) of the cases in the front of invasion, with predominance of score 2 (n=16; 34.8%) and in 67.9% (n=31) of the cases in the center of the tumor, with predominance of score 1 (n=15; 32.6%). Overall, the immunoexpression of uPA was not associated with clinical parameters. Regarding the malignant histological grading, a higher expression of uPA was observed in cases of high-grade malignancy comp ared to low-grade malignancy (p=0.05). Regarding the morphological parameters, increased expression of uPA was observed in the worst mode of invasion (p=0.03 ). The expression of uPAR was observed in 73.9% of cases in the front of invasion, with a predominance of score 1 (n=21; 45.6 %), and in 47.5% (n=21) of the cases in the center of the tumor, with a predominance of score 0 (n=25; 54.4%). Although no statistical differences were observed in relation to lymph node metastasis, clinical TNM staging, outcome, and histological grading, there was a higher expression of uPAR in cases with locoregional recurrence (p=0.04). Regarding the tumor intra -localization, it was observed an increased expression of uPA and uPAR at the front of invasion in relation to the center of the tumor (p<0.001). Regarding the correlation between uPA and uPAR, there was no statistical sign ificance. Based on these results, it is suggested that uPA and uPAR are involved in the progression of CELO, mainly in the deeper region of the tumor.

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Squamous cell carcinoma (SCC ) is the most common malignancy of the oral cavity (OSCC), with a high mortality rate. Due to this, the discovery of biomarkers that facilitate the understanding of the biological behavior of the tumor and improve treatment is necessary. Urokinase type plasminogen activator (uPA) and its receptor, uPAR, are responsible for the proteolysis of structures of the basement membrana and extracellular matrix, facilitating tumor invasion. This study aims to assess the immuno expression of these proteins in 46 cases of squamous cell carcinoma of the oral tongue (OTSCC). These results were related to the presence of metastasis, clinical TNM staging, locoregional recurrence, outcome of the lesion and histological grading. Immunostaining of each case was evaluated semiquantitatively, in the front of invasion and center of the tumor, in which scores were assigned: 0 (0% of positive cells), 1 (1-10% of positive cells), 2 (11 -50% positive cells) and 3 (more than 50% positive cells). The expression of uPA was observed in 93.5% (n=43) of the cases in the front of invasion, with predominance of score 2 (n=16; 34.8%) and in 67.9% (n=31) of the cases in the center of the tumor, with predominance of score 1 (n=15; 32.6%). Overall, the immunoexpression of uPA was not associated with clinical parameters. Regarding the malignant histological grading, a higher expression of uPA was observed in cases of high-grade malignancy comp ared to low-grade malignancy (p=0.05). Regarding the morphological parameters, increased expression of uPA was observed in the worst mode of invasion (p=0.03 ). The expression of uPAR was observed in 73.9% of cases in the front of invasion, with a predominance of score 1 (n=21; 45.6 %), and in 47.5% (n=21) of the cases in the center of the tumor, with a predominance of score 0 (n=25; 54.4%). Although no statistical differences were observed in relation to lymph node metastasis, clinical TNM staging, outcome, and histological grading, there was a higher expression of uPAR in cases with locoregional recurrence (p=0.04). Regarding the tumor intra -localization, it was observed an increased expression of uPA and uPAR at the front of invasion in relation to the center of the tumor (p<0.001). Regarding the correlation between uPA and uPAR, there was no statistical sign ificance. Based on these results, it is suggested that uPA and uPAR are involved in the progression of CELO, mainly in the deeper region of the tumor.

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DNA repair systems, genes and proteins are essential for genome integrity maintenance, avoiding serious diseases such as cancer. Deregulation in the expression of those proteins has been associated with both the risk of development and evolution of various human cancers, including oral squamous cell carcinoma. The purpose of this study was to analyze the immunoreactivity of the DNA repair proteins XRCC1, THIIF and XPF in oral tongue squamous cell carcinoma (OTSCC) and to investigate its association with clinical and histopathological parameters, outcome and 5-year survival rate. Seventy-four cases of OTSCC were analyzed semi-quantitatively through immunohistochemistry. We observed that DNA repair proteins were highly expressed in parenchymal cells; however, we only observed a significant association between XRCC1 high expression and better clinical staging (p=0,02). Cox regression showed that tumor size (p<0,01), lymph node involvement (p=0,04), tumor stage (p=0,02) and depth of invasion> 4mm (p=0,05) were prognostic factors. The results of this experiment suggest that XRCC1, TFIIH and XPF participate in the tumorigenic process, however, their immunoexpression may not be used as an independent prognostic indicator for OTSCC.

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DNA repair systems, genes and proteins are essential for genome integrity maintenance, avoiding serious diseases such as cancer. Deregulation in the expression of those proteins has been associated with both the risk of development and evolution of various human cancers, including oral squamous cell carcinoma. The purpose of this study was to analyze the immunoreactivity of the DNA repair proteins XRCC1, THIIF and XPF in oral tongue squamous cell carcinoma (OTSCC) and to investigate its association with clinical and histopathological parameters, outcome and 5-year survival rate. Seventy-four cases of OTSCC were analyzed semi-quantitatively through immunohistochemistry. We observed that DNA repair proteins were highly expressed in parenchymal cells; however, we only observed a significant association between XRCC1 high expression and better clinical staging (p=0,02). Cox regression showed that tumor size (p<0,01), lymph node involvement (p=0,04), tumor stage (p=0,02) and depth of invasion> 4mm (p=0,05) were prognostic factors. The results of this experiment suggest that XRCC1, TFIIH and XPF participate in the tumorigenic process, however, their immunoexpression may not be used as an independent prognostic indicator for OTSCC.

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Melanocytic nevi (MNs) are benign melanocytic proliferations of cells, which can be found in the skin and mucous coat, including the oral mucosa. However, skin NMs are more common when compared to those that affect the oral mucosa. The molecular mechanisms involved in the development of nevi and the factors that can influence the migration pattern of the nevus cells are little explored. The aim of this study was to analyze the immunohistochemical expression of E-cadherin protein and Bcl-2 in oral / skin NMs and relate them to the clinical characteristics (gender, age, location, exposure to solar radiation) and histopathological types. 36 cases of oral NMs and 34 Skin NMs were analyzed. The immunohistochemistry was used of the protein E-cadherin and bcl-2, which were analyzed the intensity (weak, moderate and strong) and distribution marking (diffuse and focal). The immunoreactivity also analyzed as to the types of nevus cells (epithelioid cells -A, -B lymphocyte and fibroblast-like -C). Statistical analysis was performed using the chi-square tests of Pearson and Spearman correlation with significance level set at 5%. Of the 70 cases of NMs, 82.9% were female, 48.6% aged 26-50 years, 51.4% were diagnosed histologically as intradermal / intramucosal nevi and 80% were NMs acquired. Immunohistochemical expression of BCL2 and E-cadherin were variables in the sample and showed no association with clinical parameters. The expression of bcl-2 and E-cadherin were variable according to the types of nevus cells (A, B and C) (P = 0.001). The expression of bcl-2 was more diffuse in congenital MNs (p = 0.002). E-cadherin was positive in 83.3% of MNs <1cm (p = 0.001) and exhibited weak staining in 73.9% of MNs that were in exposed areas (p = 0.010). Based on these results, it is suggested that the E-cadherin has a modulating effect on the migratory properties of NMs, and bcl-2 is a marker of MNs with increased proliferative capacity.

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Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex® 355; Tween® 80; Spam® 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q®). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way

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Riboflavin is a vitamin very important in aerobic organisms, as a precursor of many coenzymes involved in the electron transporter chain. However, after photosensitization of riboflavin with UV or visible light, it generates reactive oxygen species (ROS), which can oxidize the DNA. The repair of oxidative lesions on DNA occurs through the base excision repair pathway (BER), where APE1 endonuclease plays a central role. On the other hand, the nucleotide excision repair pathway (NER) repairs helix-distorting lesions. Recently, it was described the participation of NERproteins in the repair of oxidative damage and in stimulation of repair function fromAPE1. The aim of this research was to evaluate the cytotoxic effects of photosensitized riboflavin (RF*) in cells proficient and deficient in NER, correlating with APE1 expression. For this propose, the cells were treated with RF* and it was performed the cell viability assay, extraction of whole proteins, cells fractionation, immunoblotting, indirect immunofluorescence and analysis of polymorphisms of BER gens. The results evidenced that cells deficient in XPA and CSB proteins were more sensitive to RF*. However, XPC-deficient cells presented similar resistance to MRC5- SV cells, which is proficient in NER. These results indicate that XPA and CSB proteins have an important role on repair of oxidative lesions induced by RF*. Additionally, it was evidenced that single nucleotide polymorphisms (SNPs) in BER enzymes may influence in sensitivity of NER-deficient cell lines. Concerning the APE1 expression, the results showed that expression of this protein after treatment with RF* only changed in XPC-deficient cells. Though, it was observed that APE1 is recruited and is bound to chromatin in MRC5-SV and XPA cells after treatment with RF*. The results also showed the induction of DNA damage after treatment with RF*, through the analysis of-H2AX, since the treatment promoted an increase of endogenous levels of this phosphorylated protein, which acts signaling double strand-break on DNA. On the other hand, in XPC-deficient cells, regardless of resistance of RF*, the endogenous levels of APE1 are extremely reduced when compared with other cell lines and APE1 is not bound to chromatin after treatment with RF*. These results conclude that RF* was able to induce cell death in NERdeficient cells, where XPA and CSB cells were more sensitive when compared with MRC5-SV and XPC-deficient cells. This last result is potentially very interesting, since XPC-deficient cell line presents low levels of APE1. Additionally, the results evidenced that APE1 protein can be involved in the repair of oxidative damage induced by RF*, because APE1 is recruited and bound strongly to chromatin after treatment.

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This work aimed to develop a suitable magnetic system for administration by the oral route. In addition to that, it was intended to review the current uses of magnetic systems and the safety related to magnetic field exposure. Methods: Coprecipitation and emulsification/crosslinking were carried out in order to synthesize magnetite particles and to coat them, respectively. Results: According to literature review, it was found that magnetic particles present several properties such as magnetophoresis in magnetic field gradient, production of a surrounding magnetic field, and heat generation in alternated magnetic field. When the human organism is exposed to magnetic fields, several interaction mechanisms come into play. However, biological tissues present low magnetic susceptibility. As a result, the effects are not so remarkable. Concerning the development of a magnetic system for oral route, uncoated magnetite particles did undergo significant dissolution at gastric pH. On the other hand, such process was inhibited in the xylan-coated particles. Conclusions: Due to their different properties, magnetic systems have been widely used in biosciences. However, the consequent increased human exposure to magnetic fields has been considered relatively safe. Concerning the experimental work, it was developed a polymer-coated magnetic system. It may be very promising for administration by the oral route for therapy and diagnostic applications as dissolution at gastric pH hardly took place

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Introduction: The chronic immunosuppression promotes the development of changes in the oral cavity of the kidney transplant recipients (KTR), however with the exception of gingival overgrowth, little is known regarding the prevalence of oral lesions in this population. Objective: To evaluate the prevalence of clinical and microbiological conditions of the oral cavity of the recipients of kidney transplantation and the associated factors. Methods: This was a cross-sectional study which examined 96 clinical KTR and experimental where collected saliva stimulated them to identify Candida sp. Data collection consisted of evaluation stomatologic, socio-demographic, clinical aspects of transplantation, condition of oral hygiene and dental caries, yonder to questions about knowledge of oral alteration after transplantation. Results: Of the total, 66.7% of KTR had some type of oral manifestation. The most common was saburral tongue, followed by gingival overgrowth, with both oral manifestations related to gender and concomitant use of cyclosporine and nifedipine (p <0.05). Tacrolimus showed a protective effect for gingival overgrowth (OR = 0.13). The oral hygiene was associated with saburral tongue(p = 0.03) and severity of gingival overgrowth (p = 0.0001). Oral candidiasis was diagnosed in 17.7% of patients and Candida albicans was isolated most frequently in the saliva of RTR with a colonization of 58.3%. The average DMF-T increased with age. The method of oral hygiene was most used brush and toothpaste to 61.5%. Changes in the oral cavity was seen in 54.2% of KTR, citing as the main growth and gingival ulcers. Instructions for oral hygiene after transplantation were neglected for 61.5% of RTR. Dry mouth and halitosis were reported in 30.2% and 36.5% respectively. Conclusions: More the half of the KTR had at least one injury of the mouth, the immunosuppressive drugs and oral hygiene are associated with these alterations. Prospective cohort studies are needed to elucidate the relationship between oral manifestations and levels of drug and risk of oral manifestations occur over time. The kidney transplant recipients showed to be aware of oral alterations occurred after transplantation and uninformed about the oral hygiene instructions. With regard to hygiene, the incidence of caries was considered high, conditions of risk were identified and improvements in primary attention should be encouraged and reflected in the monitoring of renal transplant

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Magnetic targeting is being investigated as a means of local delivery of drugs, combining precision, minimal surgical intervention, and satisfactory concentration of the drug in the target region. In view of these advantages, it is a promising strategy for improving the pharmacological response. Magnetic particles are attracted by a magnetic field gradient, and drugs bound to them can be driven to their site of action by means of the selective application of magnetic field on the desired area. Helicobacter pylori is the commonest chronic bacterial infection. The treatment of choice has commonly been based upon a triple therapy combining two antibiotics and an anti-secretory agent. Furthermore, an extended-release profile is of utmost importance for these formulations. The aim of this work was to develop a magnetic system containing the antibiotic amoxicillin for oral magnetic drug targeting. First, magnetic particles were produced by coprecipitation of iron salts in alkaline medium. The second step was coating the particles and amoxicillin with Eudragit® S-100 by spray-drying technique. The system obtained demonstrated through the characterization studies carried out a possible oral drug delivery system, consisting in magnetite microparticles and amoxicillin, coated with a polymer acid resistant. This system can be used to deliver drugs to the stomach for treatment of infections in this organ. Another important finding in this work is that it opens new prospects to coat magnetic microparticles by the technique of spray-drying.

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O zinco é um micronutriente fundamental para as funções vitais de qualquer organismo vivo e sua deficiência em humanos pode causar alterações na expressão gênica, crescimento e desenvolvimento infantil, e proteção antioxidante. Devido à sua importância, as concentrações corporais de zinco são estritamente controladas por processos homeostáticos complexos. Este controle reflete no fato da deficiência grave de zinco ser detectada apenas após privação crônica. Embora se estime que a deficiência leve seja comum, os métodos existentes para avaliação individual do estado corporal de zinco são limitados e pouco eficazes. O objetivo deste trabalho foi avaliar o zinco sérico basal e os parâmetros farmacocinéticos na determinação do estado corporal de zinco em crianças, estabelecendo relação entre esses índices. O estudo foi aprovado pelo Comitê de Ética em pesquisa do Hospital Universitário Onofre Lopes (CEP-HUOL) e 129 crianças, eutróficas e aparentemente saudáveis, entre 6 e 9 anos de idade, foram avaliadas antes e após a suplementação oral de zinco (5 mg Zn/dia) durante 3 meses. No início e fim do período houve a administração venosa de zinco (0,06537 mg de Zn/kg de peso) em 40 destas crianças para avaliação dos parâmetros farmacocinéticos por meio de três diferentes fórmulas de clearance de zinco. Os limites do CI (95%) para o zinco sérico basal variaram entre 0,94 1,00 e 0,91 0,98 μg/mL em meninas e meninos, respectivamente. Em relação aos parâmetros farmacocinéticos, a fórmula específica para um compartimento apresentou correlação positiva com o zinco sérico após a suplementação e foi efetiva em detectar mudanças no estado corporal de zinco

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Conselho Nacional de Desenvolvimento Científico e Tecnológico