RESUMO Objetivo A deficiência de ferro e de vitamina A são duas das principais deficiências de micronutrientes, sendo que ambos são essenciais para a vida humana e o desenvolvimento das crianças. O objetivo deste estudo foi investigar o efeito da deficiência de vitamina A na expressão de ferritina e o receptor de transferrina e sua relação com a deficiência de ferro. Métodos Cinco dietas com diferentes proporções de vitamina A para ferro foram administradas a 35 ratos Wistar machos de 21 dias de vida (sete animais por grupo). Os animais receberam a dieta por seis semanas antes de serem eutanasiados. Os níveis séricos de ferro e retinol foram medidos como parâmetros bioquímicos. Duodeno, baço e fígado foram analisados quanto à expressão de ferritina e o receptor de transferrina por Western Blotting. Resultados Em relação aos parâmetros bioquímicos, os resultados mostram que quando a vitamina A e o ferro são insuficientes, o teor de ferro sérico (74.74µg/dL) é significativamente menor do que no grupo controle (255.86µg/dL). Os resultados também mostram que a deficiência de vitamina A não influencia a expressão do receptor da transferrina, mas da ferritina. Conclusão A deficiência de vitamina A regula a expressão de ferritina em ratos Wistar machos jovens.

ABSTRACT Objective Iron deficiency and vitamin A deficiency are two of the main micronutrient deficiencies. Both micronutrients are essential for human life and children's development. This study aimed to investigate the effects of vitamin A deficiency on ferritin and transferrin receptors' expression and its relationship with iron deficiency. Methods Five diets with different vitamin A-to-iron ratios were given to thirty five 21-day-old male Wistar rats (separated in groups of seven animals each). The animals received the diet for six weeks before being euthanized. Serum iron and retinol levels were measured as biochemical parameters. Their duodenums, spleens, and livers were analyzed for the expression of ferritin and transferrin receptors by Western Blotting. Results Regarding biochemical parameters, the results show that when both vitamin A and iron are insufficient, the serum iron content (74.74µg/dL) is significantly lower than the control group (255.86µg/dL). The results also show that vitamin A deficiency does not influence the expression of the transferrin receptor, but only of the ferritin one. Conclusion Vitamin A deficiency regulates the expression of ferritin in young male Wistar rats.

ABSTRACT Aptamers are short single-stranded RNA or DNA oligonucleotides that are capable of binding various biological targets with high affinity and specificity. Their identification initially relies on a molecular process named SELEX (Systematic Evolution of Ligands by EXponential enrichment) that has been later modified in order to improve aptamer sensitivity, minimize duration and cost of the assay, as well as increase target types. Several biochemical modifications can help to enhance aptamer stability without affecting significantly target interaction. As a result, aptamers have generated a large interest as promising tools to compete with monoclonal antibodies for detection and inhibition of specific markers of human diseases. One aptamer-based drug is currently authorized and several others are being clinically evaluated. Despite advances in the knowledge of parasite biology and host-parasite interactions from "omics" data, protozoan parasites still affect millions of people around the world and there is an urgent need for drug target discovery and novel therapeutic concepts. In this context, aptamers represent promising tools for pathogen identification and control. Recent studies have reported the identification of "aptasensors" for parasite diagnosis, and "intramers" targeting intracellular proteins. Here we discuss various strategies that have been employed for intracellular expression of aptamers and expansion of their possible application, and propose that they may be suitable for the clinical use of aptamers in parasitic infections.

Objetivo: establecer la frecuencia de diabetes mellitus gestacional (DMG) y explorar posibles factores de riesgo para su desarrollo en un grupo de gestantes atendidas en primer nivel de atención. Materiales y métodos: estudio de corte transversal analítico en gestantes atendidas en ASSBASALUD ESE, institución privada de primer nivel de atención en salud ubicada en Manizales (Colombia) en los años 2011-2012. No se incluyeron pacien tes con diabetes mellitus diagnosticada previa al embarazo. Muestreo consecutivo. Se evaluaron las variables demográficas y antropométricas de los recién nacidos, la vía del parto, el diagnóstico de laboratorio de DMG y el resultado de la prueba de O'Sullivan. Se describe la prevalencia de periodo y se hace comparación entre el grupo que presentó DMG y el que no la presentó, mediante la prueba Chi 2 y la prueba t. Resultados: se incluyeron 1.138 mujeres. Se encontró 6,3 % de prevalencia de DMG, y una prevalencia de 10,7 % de prueba de O'Sullivan positiva. La mayor prevalencia de DMG se encontró en mujeres con formación universitaria (15,2 %), con una edad comprendida entre los 40 y 50 años (21,4 %), con dos o más gravideces (7,6 %). De las pacientes del estudio que presentaron sobrepeso, el 8,3 % desarrolló DMG. El peso de los bebés de gestantes con DMG fue de 3.263 g promedio. El 6,5 % de las gestantes con excesivo aumento de peso presentó DMG, comparado con el 3,8 % presentado por las gestantes con aumento de peso normal. No se encontró relación entre el desarrollo de DMG y la no asistencia al curso psicoprofiláctico. Conclusiones: La proporción de DMG en gestantes encontrada en la presente investigación, está dentro de los límites hallados en población mundial. La edad de la gestante, sus partos previos y el nivel educativo mostraron asociación con el desarrollo de DM.

Objective: To determine the frequency of gestational diabetes mellitus (GDM) and explore potential risk factors in pregnant women seen in primary care. Materials and methods: Analytical cross-sectional study in pregnant women seen at ASSBASALUD ESE, a private, level-one healthcare institution in Manizales (Colombia), in 2011- 2012. Patients diagnosed with diabetes mellitus before pregnancy were not included. Consecutive sampling. Demographics and anthropometric variables of the neonates, route of deliver y, laboratory diagnosis of GDM and the result of the O'Sullivan test were assessed. Period prevalence is described and a comparison is made between the group presenting GDM and the group that did not, using the Chi square and t tests. Results: Overall, 1,138 women were included. The prevalence of GDM was found to be 6.3 % and the prevalence of a positive O'Sullivan test was found to be 10.7%. The highest prevalence of GDM was found among women with college education (15.2%), between the ages of 40-50 (21.4%), with two or more pregnancies (7.6 %). Of the patients in the study who were overweight, 8.3% developed GDM. Babies born to mothers with GDM had a mean weight at birth of 3,263 g. Among pregnant women with excess weight gain, 6.5 % developed GDM, compared to 3.8 % in women with normal weight gain. No relationship was found between the development of GDM and non-attendance to psychoprophylactic preparation. Conclusions: The proportion of GDM in the study population was comparable to that found in other populations. No risk factors were found in the study population.