Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests.

OBJETIVO E MÉTODOS: Estimar a concentração de iodo urinário (CIU) mediana e correlacioná-la com os indicadores de nutrição geral e com o índice de desigualdade social (IDS) de 50 escolas estaduais de ensino fundamental de 10 municípios do estado de Querétaro, no México. RESULTADOS: Utilizou-se um total de 1.544 crianças e encontrou-se uma ingestão acima das necessidades de iodo (CIU mediana de 297 µg/L). O nível de iodo determinado foi deficiente, adequado, mais do que adequado e excessivo em 2, 4, 19 e 25 escolas, respectivamente. Setenta e sete por cento de amostras de sal de mesa mostraram uma quantidade de iodo adequada (20-40 ppm), enquanto 9,6% das amostras tinham um teor de iodo baixo (< 15 ppm). As medianas de CIU por escola foram correlacionadas positivamente com as medianas do índice de massa corporal (IMC) usando o desvio-padrão da contagem (DP) (r = 0,47; p < 0.005), o DP da altura (r = 0,41; p < 0.05) e a prevalência de sobrepeso e de obesidade (r = 0,41; p < 0,05). As medianas de CUI por escola foram correlacionadas negativamente com a prevalência de desnutrição (r = -0.39; p = 005) e com o índice de desigualdade social (r = -0.36; p < 0,05). Os melhores modelos de regressão múltipla mostraram que a DP do IMC e a altura foram relacionados significativamente com a CIU (p < 0,05). CONCLUSÃO: Existe uma convivência entre os dois extremos de ingestão de iodo (insuficiente e excessiva). Em nosso conhecimento, a correlação positiva entre a CIU, o excesso de peso e a obesidade não foi descrita anteriormente e poderia ser explicada pela disponibilidade e consumo de alimentos ou refeições ricos(as) em energia e sal iodado.

OBJECTIVE AND METHODS: To estimate median urinary iodine concentration (UIC), and to correlate it with global nutrition indicators and social gap index (SGI) in 50 elementary state schools from 10 municipalities in the State of Queretaro, Mexico. RESULTS: 1,544 students were enrolled and an above of requirements of iodine intake was found (median UIC of 297 µg/L). Iodine status was found as deficient, adequate, more than adequate and excessive in 2, 4, 19 and 25 schools, respectively. Seventy seven percent of table salt samples showed adequate iodine content (20-40 ppm), while 9.6% of the samples had low iodine content (< 15 ppm). Medians of UIC per school were positively correlated with medians of body mass index (BMI) by using the standard deviation score (SDS) (r = 0.47; p < 0.005), height SDS (r = 0.41; p < 0.05), and overweight and obesity prevalence (r = 0.41; p < 0.05). Medians of UIC per school were negatively correlated with stunting prevalence (r = -0.39; p = 005) and social gap index (r = -0.36; p < 0.05). Best multiple regression models showed that BMI SDS and height were significantly related with UIC (p < 0.05). CONCLUSIONS: There is coexistence between the two extremes of iodine intake (insufficient and excessive). To our knowledge, the observed positive correlation between UIC and overweight and obesity has not been described before, and could be explained by the availability and consumption of snack food rich in energy and iodized salt.

Importancia del yodo en la gestación. El yodo es un nutrimento constituyente indispensable de las hormonas tiroideas (HT). Las HT participan activamente en periodos críticos del desarrollo cerebral durante las etapas embrionaria, fetal y posnatal. Por lo tanto la ausencia o deficiencia de las HT o de yodo en estas etapas del desarrollo produce un daño cerebral irreversible. De hecho, se sabe que la deficiencia de yodo es la principal causa de daño cerebral prevenible en el mundo. Debido a los ajustes fisiológicos propios de la gestación los requerimientos de yodo se incrementan notablemente, pasando de 150 μg al día en la mujer adulta no gestante a 250 μg al día durante el embarazo. Por otra parte, estudios epidemiológicos recientes hechos en todo el mundo muestran que el consumo de yodo durante la gestación es insuficiente en varios países; incluso en países desarrollados como Australia y España e Italia. En la presente revisión se da un panorama general de la importancia del consumo adecuado de yodo durante la gestación.

Iodine is an essential constituent of thyroid hormones (TH). TH actively take part in critical periods of brain development during embryonic, fetal and postnatal stages. Therefore the absence of TH or iodine in these critical periods produces an irreversible brain damage. In fact, it is known that iodine deficiency is the leading cause of preventable brain damage worldwide. Because of the physiological adjustments during pregnancy iodine requirements increase significantly from 150 μg per day in non-pregnant adult women to 250 μg per day. Moreover, recent epidemiological studies around the world show that iodine intake during pregnancy is insufficient in many countries, even in developed countries like Australia, Spain and Italy. In the present work an overview of the importance of iodine nutrition during pregnancy is given.

Diabetes mellitus type 1 is a multifactorial metabolic disease in which immunological mechanisms play an essential role. Once the disease is fully established, affected individuals are dependent upon exogenous insulin administration. Current research has identified a pancreatic population resembling stem cells features. This population of nestin-positive cells is activated under specific circumstances and opens the possibility of developing procedures for obtaining new β cells for the regeneration of the pancreatic islets. In this work we review the embryonic development of pancreas, pancreatic stem cells, the current models for the induction of stem cells in adult pancreas, the role of free radicals on the induction of new stem cells, and the current therapeutic procedures to improve the expression of these cells.

La diabetes mellitus tipo 1 es una enfermedad metabólica multifactorial en la que los mecanismos inmunológicos juegan un papel fundamental. Una vez desarrollada la enfermedad, los pacientes son dependientes de la administración exógena de insulina. Actualmente, el campo de la investigación experimental ha identificado una población pancreática con características de células madre. Esta población de células positivas a nestina, se expresa bajo ciertas condiciones especiales y abre la posibilidad de desarrollar técnicas para la obtención de nuevas células β que pudieran regenerar el tejido dañado. Este trabajo es una revisión acerca del desarrollo embrionario del páncreas, las células madre pancreáticas embrionarias, los modelos actuales de lesión para la inducción de la expresión de células madre en páncreas adultos, el papel de los radicales libres sobre la expresión de nuevas células madre y las terapias experimentales actuales para mejorar la expresión de estas células.