Glutamatergic system components as potential biomarkers and therapeutic targets in cancer in non-neural organs.

Glutamate is one of the most abundant amino acids in the blood. Besides its role as a neurotransmitter in the brain, it is a key substrate in several metabolic pathways and a primary messenger that acts through its receptors outside the central nervous system (CNS). The two main types of glutamate receptors, ionotropic and metabotropic, are well characterized in CNS and have been recently analyzed for their roles in non-neural organs. Glutamate receptor expression may be particularly important for tumor growth in organs with high concentrations of glutamate and might also influence the propensity of such tumors to set metastases in glutamate-rich organs, such as the liver. The study of glutamate transporters has also acquired relevance in the physiology and pathologies outside the CNS, especially in the field of cancer research. In this review, we address the recent findings about the expression of glutamatergic system components, such as receptors and transporters, their role in the physiology and pathology of cancer in non-neural organs, and their possible use as biomarkers and therapeutic targets.

Synchronization of the circadian clock by time-restricted feeding with progressive increasing calorie intake. Resemblances and differences regarding a sustained hypocaloric restriction.

Circadian rhythms are the product of the interaction of molecular clocks and environmental signals, such as light-dark cycles and eating-fasting cycles. Several studies have demonstrated that the circadian rhythm of peripheral clocks, and behavioural and metabolic mediators are re-synchronized in rodents fed under metabolic challenges, such as hyper- or hypocaloric diets and subjected to time-restricted feeding protocols. Despite the metabolic challenge, these approaches improve the metabolic status, raising the enquiry whether removing progressively the hypocaloric challenge in a  time-restricted feeding protocol leads to metabolic benefits by the synchronizing effect. To address this issue, we compared the effects of two time-restricted feeding protocols, one involved hypocaloric intake during the entire protocol (HCT) and the other implied a progressive intake accomplishing a normocaloric intake at the end of the protocol (NCT) on several behavioural, metabolic, and molecular rhythmic parameters. We observed that the food anticipatory activity (FAA) was driven and maintained in both HCT and NCT. Resynchronization of hepatic molecular clock, free fatty acids (FFAs), and FGF21 was elicited closely by HCT and NCT. We further observed that the fasting cycles involved in both protocols promoted ketone body production, preferentially beta-hydroxybutyrate in HCT, whereas acetoacetate was favoured in NCT before access to food. These findings demonstrate that time-restricted feeding does not require a sustained calorie restriction for promoting and maintaining the synchronization of the metabolic and behavioural circadian clock, and suggest that metabolic modulators, such as FFAs and FGF21, could contribute to FAA expression.

Mechanistic Effects of Calcitriol in Cancer Biology.

Besides its classical biological effects on calcium and phosphorus homeostasis, calcitriol, the active vitamin D metabolite, has a broad variety of actions including anticancer effects that are mediated either transcriptionally and/or via non-genomic pathways. In the context of cancer, calcitriol regulates the cell cycle, induces apoptosis, promotes cell differentiation and acts as anti-inflammatory factor within the tumor microenvironment. In this review, we address the different mechanisms of action involved in the antineoplastic effects of calcitriol.

Iodine nutrition in elementary state schools of Queretaro, Mexico: correlations between urinary iodine concentration with global nutrition status and social gap index.

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.

Iodine nutrition in elementary state schools of Queretaro, Mexico: correlations between urinary iodine concentration with global nutrition status and social gap index / Consumo de iodo em escolas de ensino fundamental de Querétaro, México: correlação entre a concentração urinária de iodo, o estado nutricional geral e o índice de desigualdade social

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.

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.

Iodine nutrition status in pregnant women in Mexico.

BACKGROUND: Iodine nutrition during pregnancy has become an important public health concern because of the deleterious impact of iodine deficiency on brain development during fetal and early postnatal life. Iodine nutrition status can be assessed in a population by the median urinary iodine concentration (UIC). World Health Organization, the United Nations Children's Fund, and the International Council for Iodine Deficiency Disorders have established that a median of UIC between 150 and 249 µg/L in pregnant women indicates an adequate iodine intake. The aim of this study was to assess iodine nutrition status in Mexican pregnant women. METHODS: Two hundred ninety-four pregnant women receiving prenatal care in the Public Medical Units of the State Ministry of Health for each pregnancy trimester (first, n=60; second, n=103; and third, n=131) in Queretaro, Mexico, were enrolled to assess UIC by the Sandell-Kholtoff method. RESULTS: The median of UIC was 273, 285, and 231 µg/L in the first, second, and third trimesters of gestation, respectively. Globally, the median (range) of UIC was 260 (5-1320) µg/L, and the percentage of samples with UIC below 150 µg/L was 28%. There was no significant difference between the UIC of women using iodine-containing multivitamins compared with those who reported the consumption of noniodized multivitamins (p>0.05). In addition, we found no difference between the UIC of women using iodized table salt compared with those who employed noniodized table salt, with those who did not know whether their table salt was iodized (p>0.05). CONCLUSIONS: Based on the median UIC, iodine intake in Queretaro, Mexico, is slightly above requirements during the first two trimesters, and adequate in the third trimester. The wide Mexican universal iodized salt program seems to supply adequate dietary iodine to pregnant women without health insurance in this region. However, regular monitoring of iodine status is recommended during pregnancy throughout Mexico.