Análise do vetor de impedância bioelétrico na avaliação da suplementação de zinco em crianças prepuberais e sadias

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Preparação de óxidos mistos de níquel e zinco nanoparticulados a partir de combustíveis alternativos

The field of "Materials Chemistry" has been developing in recent years and there has been a great increase of interest in the synthesis and chemical and physical properties of new inorganic solids. New routes of synthesis and synthesis modified has been developed with the aim not only to optimize the processes in laboratory scale, but also on an industrial scale, and make them acceptable by current environmental legislation. The phenomenology of current solid state chemistry properties coupled with the high temperature superconductivity, ferromagnetism, porosity molecular and colors are evidence affected by the synthesis method, which in turn can influence the technological application of these materials. From this understanding, mixed oxides of nickel and zinc nanoparticulate were synthesized by microwave-assisted combustion route using three specific types of organic fuels employing the weight ratios 1:1/2 and 1:1 of cation metallic/fuel, in order to investigate the influence of such proportions to obtain the solids. The new fuels were chosen to replace, for example, urea or glycine that are the fuels most commonly preferred in this kind of synthesis. The powders without heat treatment were studied by Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD) and then calcined at 900°C. After heat treatment, the samples were characterized by analysis of X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The modified synthesis route porposed was effective for obtaining powders. Both the alternative fuels chosen as the different weight ratios employed, influenced in the morphology and obtaining oxides

Estudo da síntese e propriedade magnética de ferritas de manganês/cobalto dopadas com níquel

For the chemical method of synthesis of co-precipitation were produced ferrite powders manganese-cobalt equal stoichiometric formula Mn (1-x) Co (x) Fe2O4, for 0 < x < 1, first reagent element using as the hydroxide ammonium and second time using sodium hydroxide. The obtained powders were calcined at 400 ° C, 650 ° C, 900 ° C and 1150 ° C in a conventional oven type furnace with an air atmosphere for a period of 240 minutes. Other samples were calcined at a temperature of 900 ° C in a controlled atmosphere of argon, to evaluate the possible influence of the atmosphere on the final results the structure and morphology. The samples were also calcined in a microwave oven at 400 ° C and 650 ° C for a period of 45 minutes possible to evaluate the performance of this type of heat treatment furnace. It was successfully tested the ability of this group include isomorphic ferrite with the inclusion of nickel cations in order to evaluate the occurrence of disorder in the crystalline structures and their changes in magnetic characteristics.To identify the structural, morphological, chemical composition and proportions, as well as their magnetic characteristics were performed characterization tests of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDX), thermogravimetric (TG), vibrating sample magnetometry (MAV) and Mössbauer spectroscopy. These tests revealed the occurrence of distortion in the crystal lattice, changes in magnetic response, occurrence of nanosized particles and superparamagnetism

Diagnóstico da possível influência da atividade petrolífera em sedimentos de fundo da Bacia Piranhas-Açu, região Baixo Açu/RN

It is located in an area of increasing oil exploration, the region of the Lower Açu is at the mercy of a possible pollution generated by this economic activity, which includes various chemical substances harmful to health, such as metals. This thesis aims to, diagnose the areas of River Piranhas-Açu, a region of the Lower Açu, which are polluted by traces factors and more. In this study, it was determined the concentration of the chemica elements Al, CD, Cr, Cu, Fe, Mn, Ni, P, Pb, V and Zn, through the technique of ICP-OES analysis and the size of sediments and their contents organic matter. Were mapped by GPS, 12 points from collections. The interpretations of the results, together associating that allowed pollution to a possible contamination by oil activity. The results showed tha some regions have low concentrations of cadmium, lead, copper, manganese and zinc unable to promote damage to human health. However, there are places where the concentrations of certain metals chromium, iron and zinc are moderately polluted compared to the results with the reference values of literature and others that are highly polluted by iron. However, due to a greater number of wells in production in those locations, those higher concentrations, it can be suggested a possible influence of oi production in some areas with concentrations of chromium and lead are higher than the rest of the points of monitoring. Moreover, it is observed that the highest levels of metals found in sediment of finer texture and more organic matter content

Sensibilidade da cinética do zinco e avaliação nutricional em crianças submetidas ao teste venoso de tolerância ao zinco

Objective: The purpose of this study was to investigate the kinetics of this micronutrient in schoolchildren between the ages of 6 and 9 years, of both sexes, and to verify its sensitivity in detecting alterations in body zinc status. Methods: Nutritional assessment was performed by body mass index. Food intake, venous zinc tolerance test and zinc kinetics were carried out before and after 3-month oral zinc supplementation. Results: Of the 42 children studied, 76.2% had healthy weight. Only energy, calcium and fiber intake were suboptimal before and after oral zinc supplementation. Serum zinc and total-body zinc clearance, although at normal levels, increased significantly after zinc supplementation. Conclusion: We concluded, therefore, that kinetics is a sensitive tool for detecting changes in body zinc status, even in children without a deficiency of this mineral. Furthermore, kinetics showed a positive response to supplementation and may be a sensitive parameter to evaluate the efficacy of this therapy

Interação competitiva do zinco e ferro após administração oral e venosa de zinco em crianças eutróficas

The aim of this study was to assess the acute and chronic effects of zinc in serum iron profile of children aged 6-9 years in relation to nutritional status and dietary intake. The study participants were 11 children regardless of sex, aged 6-9 years. They were selected from three public schools of the city of Natal, Brazil. Body mass index was used to assess nutritional status. In order to determine the patterns of childhood growth and ideal weight we used the standards of the World Health Organization. The dietary intake assessment was based on information from a three-day prospective food survey. The variables were energy intake, protein, lipids, carbohydrates, fiber, calcium, iron and zinc. All children underwent an intravenous administration of zinc (IVAZn) before and after oral administration of zinc (OAZn) (5 mg Zn / day) for three months. We measured serum iron, hematocrit, hemoglobin and total protein, before and after the use of oral zinc. The analysis of hematocrit, hemoglobin and total protein was performed using standard methods of clinical laboratory. Zinc levels and serum iron were measured by atomic absorption spectrophotometry. The project was evaluated and approved by the Ethics in Research Committee of Federal University of Rio Grande do Norte. Results: All children had normal weight. The consumption of energy, fat, fiber, calcium and iron were below recommended levels. However, the levels of protein and carbohydrates were high. Protein and zinc increased significantly after OAZn. Carbohydrate and protein were elevated in the blood. After OAZn, both protein and zinc increased, being statistically significant. Conclusion: The potential inhibitory effect of physiological or pharmacological doses of zinc on the profile of serum iron was observed in children with healthy weight and aged between 6 and 9 years. This negative effect of zinc did not affect the levels of hematocrit or hemoglobin, and therefore did not cause anemia. This was a multidisciplinary study, involving researchers from medicine, nutrition and pharmacy. This met the requirements of multidisciplinarity of the Post Graduate Program in Health Sciences of Federal University of Rio Grande do Norte.

Alterações no metabolismo de zinco relacionadas ao envelhecimento

Although many studies point to alterations in the organic concentrations of zinc in elderly patients, the mechanisms by which aging might cause changes in the metabolism of this nutrient remain unclear. Thus, we assessed the changes in plasma zinc, Zinc Binding Capacity to Plasma Protein (ZnBCPP) and Saturation Index (SI), comparing elderly individuals and young adults. The zinc analyses were performed by atomic absorption spectrophotometry. A statistically significant difference (p < 0.001) was found between the two groups, in relation to plasma zinc and SI, but the ZnBCPP did not differ between the younger and older subjects. In agreement with this result, it was shown in the young group that 76% (R2 = 0.760) of the ZnBCPP variations are explained by the variations in plasma zinc and SI. In the elderly group this measure decreased to 30.5% (R2 = 0.305). We conclude, therefore, that aging may be a factor associated to changes in control mechanisms and in zinc homeostasis, and could even alter ZnBCPP response patterns and other zinc-related indicators of nutritional status.

Estudo cinético na caracterização do status corporal de zinco na Síndrome de Berardinelli-Seip

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Zinco Sérico e parâmetros farmacocinéticos na determinação do estado corporal de zinco em crianças

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

Suplementação oral de zinco pode diminuir o perfil sérico de ferro em crianças saudáveis

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Efeito positivo da suplementação de zinco no crscimeto, GH, IGF-1 E IGFBP-3 em crianças eutróficas

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Valores de referência para cobre e zinco no plasma e no eritrócito em adultos universitários na cidade de Natal-RN

This study aimed builds reference values for copper and zinc, of healthy adults in Natal-RN, and to identify the influence of the gender, age, body mass index (BMI) and diet, on those values. They were assessed 123 healthy students of the Universidade Federal do Rio Grande do Norte (UFRN), both genders, with age between 19 and 41 years. The project was approved by the Ethics Committee in Research of UFRN. BMI was determined and the food consume was accomplished through a 24h recordatory. Dietary was evaluated as the energy, macronutrients, copper and zinc, according to the recommendations of National Academy of Sciences (2001; 2002). Analyses of the copper and zinc concentrations in the plasma and erythrocytes were accomplished by flame atomic absorption spectrometry. The casuistic came quite homogeneous as for the distribution for gender and age, being the largest number of individuals between the 19 and 24 years old. Most of the volunteers presented anthropometric nutritional state inside of the normality patterns. Chronic diseases family antecedents and sedentarysm were observed. Diet was characterized with low consumption of zinc, appropriate of copper and of lipids. Average concentrations of plasma copper (p=0,002), erythrocyte copper (μg/dL, p=0,036; μg/gHb, p=0,038), and plasma zinc (p=0,022) were different among the genders, what was demonstrated by the largest values of copper in the female gender and larger of zinc in the masculine. Plasma copper values still suffered interference of the variables: energy, carbohydrate and copper consumption, all classified in agreement with the median, besides the protein classified according to the percentage contribution for the dietary total energy. The study allowed to establish reference values for erythrocyte zinc (1.261,6-1.344,0 μg/dL e 51,0-54,3 μg/gHb) and to suggest "indicative" of reference values for plasma (108,4 130,2 μg/dL) and erythrocyte (female = 85,0 91,4 μg/dL; masculine = 80,2 86,5 μg/dL) copper and plasma zinc (female = 98,8 105,8 μg/dL; masculine = 104,6 111,6 μg/dL)

Osteopenia diabética e pós-menopausa: efeito metabólico do zinco na recuperação do volume ósseo trabecular

Diabetes mellitus has been associated with bone metabolism alterations, such as osteopenia and osteporosis. So, the search of new anabolic agents promote bone mass gain can be important to prevent osteoporosis. The aim of this study was evaluate zinc anabolic effect over bone in diabetic and post-menopausal osteopenic models. Diabetes was induced by STZ (45mg/Kg of body weight) administration and post-menopausal by bilateral ovariectomy. Adults female Wistar rats (n=65) were divided in 5 groups: control group (n=15), ovariectomized without (n=15) and with zinc supplementation (n=10) groups, diabetic and ovarioctomized without (n=15) and with zinc supplementation (n=10) groups. Studied periods had been untill 90 days. Diabetic condition was confirmed hiperglicemic state and alterations of state with polyuria, polyphagia, polydipsia and glucosuria. Histomorphometric analysis showed that zinc supplementation increased trabecular thickness and reduced trabecular distance significantly in diabetic groups with similar values to those showed in control group. Correlation analysis of histomorphometric parameters with serum glucose concentration showed that more time in hyperglycemia more bone damage, as well as, zinc supplementation contributed to prevent this damage. Elevated serum glucose caused hyperzincuria, phosphaturia and calciuria. Zinc supplementation promoted increased levels of calcium and phosphorous ions in 90th days diabetic group. No alteration was observed by ovariectomy in mineral (Ca, P and Zn) serum and urine concentrations. Total serum Alkaline Phosphatase activity increased in diabetic groups, supplemented or not, compared with control group. However, Tartarate-Resistant Acid Phosphatase, magnesium and serum zinc did not altered in studied groups. Serum albumin was reduced only in diabetic groups. Serum creatinine was unaltered. These results support the hypotesis that zinc can be used to prevent and treat diabetic and post-menopausal osteopenia

Avaliação do status de zinco e da expressão gênica de metalotioneínas em pacientes com aterosclerose tratados com rosuvastatina

The study had as objective to evaluate the zinc status by means of dietary intake, zinc in plasma and in erythrocytes and the metallothionein gene expression in patients with atherosclerosis in use of rosuvastatin. The research involved 27 adult and elderly patients of both genders with atherosclerosis that were treated with rosuvastatin (10mg/day) during 4 months. We performed the dosage of lipids, glucose, AST and ALT, ultrasensitive C-reactive protein (hsCRP), plasmatic and erythrocyte zinc and 1 and 2 metallothionein gene expression. The assessment of body mass index (BMI) and abdominal circumference (AC) was performed, besides the analysis of dietary intake of patients. The majority of the evaluated patients presented overweight, before and after the treatment, with no significant difference between the times of the study. It was identified that the AC was significantly reduced in the group (p<0.05) after the intervention. The majority of the patients had intake below the recommendation of calories and fibers and above recommendation of proteins. The mono and polyunsaturated fats were adequate for the majority of the patients, however, the saturated fat and cholesterol were consumed in excess by a great part of the individuals. The intake of zinc was inadequate, being noticed an inadequacy of 100% in the male gender and of 84% in the female. After the treatment with rosuvastatin there was a significant reduction in the total cholesterol (TC) and LDL-c (p<0.01) and no alterations were observed in the HDL-c and triacylglycerols. It was also verified that the reduction of glycemia (p<0.05) and of hsCRP (p<0.01). The analysis did not demonstrate significant differences in the plasmatic and erythrocyte zinc concentration after the treatment. There was, after the treatment, reduction of the MT1F gene (p<0.05) without, however, occurring significant alterations in the MT2A gene. The treatment with rosuvastatin was effective in the reduction of TC and LDL-c, and promoted the reduction of inflammatory marker hsCRP. The zinc in the plasma and erythrocyte was not altered by the use of the medication and there was a reduction in the MT1F gene, possibly due to the reduction of inflammation. The majority of patients presented inadequate intake of zinc and this inadequacy did not have relation with the mineral parameters in plasma and erythrocytes or with the metallothionein gene expression

Obtenção de cerâmicas à base de tricálcio fosfatos utilizando óxido de manganês como aditivo

The calcium phosphate ceramics have been very investigated as material for bone implants. The tricalcium phosphate (β-TCP) had a great potential for application in temporary implants like a resorbable bioceramic. This material presents a limitation in its sintering temperature due to occurrence of the allotropic transformation β → α at temperatures around 1200°C, not allowing the attainment of dense ceramic bodies. This transformation also causes cracks, what diminishes the mechanical strength, limiting its use to applications of low mechanical requests. This work studies the influence of the addition of manganese oxide in the sintering of β-TCP. Two processing routes were investigated. The first was the powder metallurgy conventional process. The test bodies (samples) were pressed and sintering at temperatures of 1200 and 1250°C. The second route was uniaxial hot pressing and its objective was to obtain samples with high relative density. The samples were physically characterized through density and porosity measurements. The thermal behavior was studied through dilatometric, thermal differential and thermogravimetric analysis. The mechanical properties were characterized by three point flexure test and Vickers microhardness measurements. The microstructure was analyzed by scanning electron microscopy. The addition of manganese oxide caused an improvement of the mechanical strength in relation to the material without additive and promoting the stabilization of β-TCP to greater temperatures