Kelly das Graças Fernandes Dantas

Downregulation of TNF-α and VEGF expression by Sp1 decoy oligodeoxynucleotides in mouse melanoma tumor

Melanoma tumor growth and progression are highly dependent on adequate blood supply through angiogenesis. Since several genes involved in angiogenesis revealed potential binding sites for the transcription factor Sp1, we have examined the effects of local inoculation of Sp1 decoy oligodeoxynucleotides (ODNs) on the growth of transplanted murine melanoma tumors and the expression of VEGF and TNF-α within these tumors. Treatment with Sp1 decoy ODNs, but not their mutated form, led to a significant increase (P=0.041) of the tumor necrotic area, as evaluated morphometrically. Tumor necrosis was associated with a significant decrease of microvascular density (P=0.012) and relative vascular area (P=0.026), as determined by counting CD34-positive vascular structures within the tumor microenvironment of Sp1 decoy ODNs and control ODN-treated tumors. RT-PCR experiments showed a strong decrease in the levels of VEGF188 and VEGF164 isoforms and a moderate decrease of TNF-α in Sp1 decoy-treated tumors. Taken together, our results indicate that Sp1 decoy ODNs may inhibit angiogenesis by affecting the gene expression of key players in angiogenesis such as TNF-α and VEGF. These findings indicate that Sp1 decoy ODNs may be a potential new therapeutic tool in antiangiogenic therapy.

Evaluation of inorganic elements in cat's claw teas using ICP OES and GF AAS.

The determination of Ba, Ca, Cu, Fe, Mg, Mn, P, Pb, and Zn by inductively coupled plasma optical emission spectrometry (ICP OES), and Se by graphite furnace atomic absorption spectrometry (GF AAS), has been carried out in dry matter and teas from 11 samples of the cats claw plant. The accuracy and precision values were verified against GBW 07604 (Poplar leaves) certified reference material and by the recovery test. Results showed a high content of Ca in the medicinal plant studied, followed by Mg and P. The values obtained showed that the elements studied have different concentrations depending on the method of tea preparation. The highest levels were observed in Ca and Mg, and the lowest for Se and Pb, by both infusion and decoction. Teas prepared from this plant were found to be at safe levels for human consumption, and may be suitable as sources of these elements in the human diet.

Comportamento do mercúrio em perfis de solos do sítio Ilha de Terra-Caxiuanã, Pará

Behavior of mercury in soil profiles with archaeological black earth (ABE) and surroundings area (SA) from Sitio Ilha de Terra, Caxiuana, can provide information on anthropogenic activity of the Amazonian habitat. The samples of ABE and SA soil profiles were submitted to mineralogical chemical (total and sequential) analysis. The data show that the Hg occurs mainly in goethite and kaolinite in the two soil profiles. The highest concentrations of Hg and Fe are observed in the SA profile. These results indicate that the prehistoric human occupation contributed to the decrease of the concentration of Hg in soil ABE from Caxiuana.

Evaluation of the physicochemical parameters and inorganic constituents of honeys from the Amazon region

The aim of this study was to determine the physicochemical composition and inorganic constituents of seventeen honey samples produced in Amazon region by different bee species (Scaptotrigona sp., Melipona fasciculata, Melipona flavolineata and Apis mellifera). The physicochemical parameters evaluated were pH, acidity, soluble solids, moisture, density, reducing sugars, apparent sucrose and hydroxymethylfurfural. Ba, Ca, Cd, Cu, Fe, Mg, Mn, P, Pb and Zn contents were determined in honey samples by inductively coupled plasma optical emission spectrometry. Na and K contents were measured in honeys by flame atomic absorption spectrometry. Honey samples were digested in a microwave oven using diluted nitric acid and hydrogen peroxide. The analytical results obtained in this study were evaluated by analysis of certified reference material (GBW 07604 Poplar leaves). The results of physicochemical analyzes showed significant differences (p < 0.05) among the species, mainly regarding moisture content, acidity, density and soluble solids. In general, the honeys from Scaptotrigona sp. showed the highest levels of minerals (Ca, Cu, K, Mg), being a good source of minerals, as well as presented significant differences (at 5% of significance) in relation to the other studied species. Thus, the results indicate new information about the composition of these honeys and emphasize the need for the implementation of specific legislation for quality assessing of honey from stingless bees.

Determination of Ca, Mg, Na, and K in Biodiesel of Oilseed from Northern Brazil

In this study flame atomic absorption spectrometry (FAAS) was used to determine calcium, magnesium, sodium and potassium contents in biodiesel produced with different oilseeds (bacaba, bacuri, brazil nut, palm). These samples were digested using open system with conventional heating with concentrated nitric and sulfuric acids plus hydrogen peroxide. The element concentrations varied considerably in the different samples. The limits of detection obtained were < 0.3 mg/kg.

Mineral Composition of Amazonian Fruits by Flame Atomic Absorption Spectrometry Using Multivariate Analysis

This study aimed to evaluate the mineral composition in native and non-native Amazonian fruits using flame atomic absorption spectrometry (FAAS) and multivariate methods, such as principal component analysis (PCA) and hierarchical cluster analysis (HCA), in order to conduct a more thorough evaluation of the original data. The accuracy was checked by certified reference material analysis (Poplar leaves) and spike experiments. The results of the analysis were in agreement with the certified values, with analytical recoveries for all analytes in an acceptable range from 82 to 113%, and relative standard deviations (RSD) were in the range of 0.2–18%. Furthermore, PCA explained 68% of the total variance, while HCA confirmed the correlations found in the PCA, allowing for the evaluation of the degree of similarity between the fruits studied. These results will be used to better understand the distribution of inorganic constituents within these Amazonian fruits.

Determinação dos Teores de Cu, Fe, Mn e Zn por FAAS em Raízes de Mandioca ( Manihot esculenta Crantz) da Amazônia Oriental

O objetivo deste estudo foi determinar a quantidade de micronutrientes Fe, Zn, Mn e Cu de nove amostras de raizes de mandioca por espectrometria de absorcao atomica com chama (FAAS) utilizando ferramentas quimiometricas como a analise exploratoria multivariada sem supervisao para tentar explicar possiveis diferencas nas suas caracteristicas quimicas e teste de Tukey para verificar a significância estatistica dos valores medios. Quatro amostras foram obtidas de um comercio local, cultivadas sem qualquer informacao sobre as condicoes ambientes de plantio ou colheita. As outras cinco amostras pertencem a um banco ativo de germoplasma (BAG) em condicoes de plantio e ambientes conhecidas. O teor de Fe variou de 0,54 a 5,24 mg/kg; Zn de 0,38 a 6,55 mg/kg; Cu de 0,04 a 0,89 mg/kg e Mn de 0,16 a 0,41 mg/kg. As amostras comerciais apresentaram resultados esperados para todos os elementos estudados, enquanto as amostras de BAG apresentaram vantagens na absorcao de ferro e zinco. As amostras do comercio local nao apresentaram ferro em sua composicao, mas foram as unicas que apresentaram manganes em sua composicao. Tal caracteristica foi, portanto, um parâmetro essencial para distinguir as amostras comerciais das outras amostrasis. O conhecimento das condicoes de plantio sao essenciais para assegurar provaveis fatores exogenos que podem causar variacoes na absorcao de micronutrientes. Esses fatores devem ser considerados como influentes na absorcao de micronutrientes em amostras de mandioca.

Afinidade e Espontaneidade de Interações Fenol e Mn (II) em Sistemas Aquosos Simples e Binários em Sítios Adsorventes de Caulinitas

Este estudo visa a caracterizacao de adsorventes, preparados a partir de rejeito de caulim sem tratamento (RC ST ) e tratado com acido humico (RC AH ), e aplicabilidade nos processos de adsorcao de fenol e Mn (II), em sistemas aquosos simples (SS) e binario (SB). A caracterizacao dos materiais foi feita por DRX, espectros FTIR, MEV/EDS e ATD/DTG. A avaliacao das afinidades dos processos de interacoes fenol e Mn (II) nos sitios adsorventes das caulinitas foi efetuada a partir dos coeficientes de distribuicao K d e a viabilidade e espontaneidade foram investigadas com base nos calculos do coeficiente de separacao (K R ) e energia livre de Gibbs (?G o ), respectivamente. Os resultados nao indicaram diferencas aparentes nos espectros FTIR e padroes de DRX dos adsorventes, mas foi verificado que as curvas ATD e DTG do RC AH, se diferenciam em relacao as do RC ST , principalmente na faixa de temperatura 350 a 400 o C, devido a decomposicao do acido humico. Nos processos de adsorcao foi verificado que q max do fenol e Mn (II) nos sistemas simples e binarios seguiu a ordem de adsorcao RC AH >RC ST e RC ST >RC AH , respectivamente. A afinidade de adsorcao do fenol em sistemas simples e binarios segue a ordem RC AH >RC ST , sendo menor nos sistemas binarios. Por outro lado, a presenca de fenol favorece o aumento de afinidade e viabilidade dos processos de adsorcao do Mn (II) nos sitios adsorventes das caulinitas. Os processos de adsorcao foram considerados espontâneos, sendo de natureza fisica nos sistemas simples e fisico-quimicos nos sistemas binarios.

Avaliação da Concentração de Elementos-traço em Farinha de Mandioca ( Manihot esculenta Crantz) por Espectrometria de Emissão Óptica com Plasma Acoplado Indutivamente

As concentracoes de Ca, Cu, Fe, K, Mg, Mn, P e Zn em 10 amostras de farinha de mandioca comercialmente disponiveis ( Manihot esculenta Crantz, Euphorbiaceae) foram analisadas por espectrometria de emissao optica com plasma acoplado indutivamente (ICP OES). Os elementos foram encontrados em ordem decrescente de concentracao, como Ca > P > Mg > Fe > Cu > Zn > Mn. Com base na ingestao diaria recomendada para adultos, os valores mostraram que o consumo de 10 g de farinha de mandioca por dia proporciona 5,3% da ingestao diaria para Cu, 0,5-1,2% para Fe, 0,5% para Ca, 0,9-1,2% para Mg, 0,6 -0,8% para Mn, 0,6% para P, 0,2% para K e 0,2-0,3% para Zn. Os resultados indicam que a farinha de mandioca contem varios elementos essenciais e nao apresenta riscos a saude humana.As concentracoes de Ca, Cu, Fe, K, Mg, Mn, P e Zn em 10 amostras de farinha de mandioca comercialmente disponiveis ( Manihot esculenta Crantz, Euphorbiaceae) foram analisadas por espectrometria de emissao optica com plasma acoplado indutivamente (ICP OES). Os elementos foram encontrados em ordem decrescente de concentracao, como Ca > P > Mg > Fe > Cu > Zn > Mn. Com base na ingestao diaria recomendada para adultos, os valores mostraram que o consumo de 10 g de farinha de mandioca por dia proporciona 5,3% da ingestao diaria para Cu, 0,5-1,2% para Fe, 0,5% para Ca, 0,9-1,2% para Mg, 0,6 -0,8% para Mn, 0,6% para P, 0,2% para K e 0,2-0,3% para Zn. Os resultados indicam que a farinha de mandioca contem varios elementos essenciais e nao apresenta riscos a saude humana.

Study of the Distribution of Metals in Tissues of Fish from Amazon Region

The purpose of this study was to evaluate the levels of Al, Ca, Cu, Fe, Mg, Mn, Na, Pb and Zn in 15 samples of five fish species (Brachyplatystoma rousseauxii, Brachyplatystoma filamentosum, Cynoscion leiarchus, Brachyplatystoma vaillanti e Colossoma macropomum) obtained in municipal market of Belém (Pará State, Brazil). These samples were digested in a cavity microwave oven using a 3.5 mol L nitric acid solution and concentrated hydrogen peroxide. Total concentrations of the studied elements were determined by flame atomic absorption spectrometry (FAAS) and graphite furnace atomic absorption spectrometry (GF AAS). The contents of the elements in fish samples ranged from 90.12-2497.09 μg g for Al, 114.05-7100.10 μg g for Ca, 43.2-150.1 μg g for Cu, 22.26-4296.62 μg g for Fe, 514.03-7520.13 μg g for Mg, 20.05-20.08 μg g for Mn, 227.93-7315.56 μg g for Na, 0.54-11.81 μg g for Pb, and 7.46-129.74 μg g for Zn. Results show that higher levels of the elements studied were found in the liver and lower levels in the muscle of fish. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to check correlations between mineral composition, length and mass of fish samples studied.