Folate induces stemness and increases oxygen consumption under glucose deprivation by notch-1 pathway activation in colorectal cancer cell.

Evidence for folate's protective effects on neural tube defects led the USA and Chile to start mandatory folic acid (FA) fortification programs, decreasing up to 50%. However, ∼30% of the population consuming fortified foods reach supraphysiologic serum levels. Although controversial, several epidemiological and clinical observations suggest that folate increases cancer risk, giving concern about the risks of FA supplementation. The Cancer stem cells (CSCs) model has been used to explain survival to anticancer therapies. The Notch-1 pathway plays a role in several cancers and is associated with the stemness process. Different studies show that modulation of metabolic pathways regulates stemness capacity in cancer. Supraphysiologic concentrations of FA increase the proliferation of HT-29 cells by Notch-1 activation. However, whether folate can induce a stemness-like phenotype in cancer is not known. We hypothesized that FA protects from glucose deprivation-induced cell death through Notch-1 activation. HT-29 cells were challenged with glucose deprivation at basal (20 nM) and supraphysiological (400 nM) FA and 5-MTHF concentrations. We analyzed changes in stemness-like gene expression, cell death and different energetic metabolic functions. Supraphysiological concentrations of FA increased stemness-like genes, and improved survival and oxygen consumption, inducing AMPK phosphorylation and HSP-70 protein expression. We evaluated the Notch-1 pathway using the DAPT and siRNA as inhibitors, decreasing the stemness-like gene expression and preventing the FA protection against glucose deprivation-induced cell death. Moreover, they decreased oxygen consumption and AMPK phosphorylation. These results suggest that FA protects against glucose deprivation. These effects were associated with AMPK activation, a critical metabolic mediator in nutrient consumption and availability that activates the Notch-1 pathway.

Next steps to advance general physical activity recommendations towards physical exercise prescription: a narrative review.

Physical inactivity is a major health concern, associated with the development of several non-communicable diseases and with an increased mortality rate. Therefore, promoting active lifestyles has become a crucial public health necessity for enhancing overall health and quality of life. The WHO guidelines for physical activity (PA) present valuable contributions in this respect; however, we believe that greater specificity should be added or complemented towards physical exercise (PE) testing, prescription and programming in future recommendations. In this review article, we suggest simple and practical tools accessible to the entire population to improve the specificity of this approach, highlighting aspects of PE programming used by trained subjects. By adopting these suggestions, exercise professionals, clinicians and physical trainers can optimise the current general PA recommendations towards PE prescription to improve fitness status and encourage PE adherence in the general population.

Mercury and selenium in oysters Saccostrea palmula and Crassostrea corteziensis from coastal lagoons of the southeastern Gulf of California: molar ratio and risk assessment on human health.

Total mercury (Hg) and selenium (Se) contents were determined in oysters Saccostrea palmula and Crassostrea corteziensis soft tissues from four coastal lagoons of the southeastern Gulf of California. The annual Hg mean concentrations for S. palmula (0.09 ± 0.04 µg g- 1, wet weight) and C. corteziensis (0.08 ± 0.04 µg g- 1) were similar (p ˃ 0.05) among the lagoons and did not exceed the limit established by the Norma Oficial Mexicana and World Health Organization (< 1.0 µg g- 1 Hg). On the other hand, the annual mean concentrations of Se for S. palmula (3.34 ± 0.96 µg g- 1) and C. corteziensis (2.79 ± 0.89 µg g- 1) were higher (p < 0.05) in El Colorado lagoon. The Se/Hg molar ratios were above 1; the positive selenium health benefit value index suggested that Se load in oysters could reduce the Hg potential toxic effect. The hazard quotient for Hg in both species was below 1. Therefore, the consumption of oysters does not represent a risk due to Hg ingestion.

Catastrophic health-care payments and multidimensional poverty: Are they related?

The negative impact of health-related out-of-pocket (OOP) payments is a well-known problem in low and middle-income countries (LMICs). Cross-sectional analysis reveals that households use different coping mechanisms to mitigate or overcome the effect of OOP payments, but little is known from a longitudinal perspective. We explore this link using panel data for Colombia, Mexico, India, Malawi, Nigeria, Uganda, and Tanzania. Using a fixed-effect model, we computed the association between multidimensional poverty (MP) and facing catastrophic health payments (CHP) using a capacity-to-pay approach. We estimated different heterogeneous effects, including variables such as area of residence, facing CHP, being poor in the first wave, and facing CHP in period two. While using cross-sectional data, we found that the association between CHP and MP is present for six of the seven countries; it is not the case for the time variation in most of them. The results provide evidence that OOP induce a long-term impact on MP only in Colombia, India and Nigeria. In the last two countries, the levels of poverty and CHP were the highest of all seven, and the association between both situations was found by using different poverty cutoffs and thresholds to define CHP.

The CB1 cannabinoid receptor regulates autophagy in the tibialis anterior skeletal muscle in mice.

The endocannabinoid system (ECS) regulates energy metabolism, has been implicated in the pathogenesis of metabolic diseases and exerts its actions mainly through the type 1 cannabinoid receptor (CB1). Likewise, autophagy is involved in several cellular processes. It is required for the normal development of muscle mass and metabolism, and its deregulation is associated with diseases. It is known that the CB1 regulates signaling pathways that control autophagy, however, it is currently unknown whether the ECS could regulate autophagy in the skeletal muscle of obese mice. This study aimed to investigate the role of the CB1 in regulating autophagy in skeletal muscle. We found concomitant deregulation in the ECS and autophagy markers in high-fat diet-induced obesity. In obese CB1-KO mice, the autophagy-associated protein LC3 II does not accumulate when mTOR and AMPK phosphorylation levels do not change. Acute inhibition of the CB1 with JD-5037 decreased LC3 II protein accumulation and autophagic flux. Our results suggest that the CB1 regulates autophagy in the tibialis anterior skeletal muscle in both lean and obese mice.

Biomonitoring of potentially toxic elements through oysters (Saccostrea palmula and Crassostrea corteziensis) from coastal lagoons of Southeast Gulf of California, Mexico: health risk assessment.

The coastal lagoons of the Gulf of California support important traditional fisheries and mollusc cultures (generally oysters) and receive important volumes of agricultural, industrial and urban effluents, consumption of the oysters could pose risk to human health. The concentrations of arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in the oysters Saccostrea palmula and Crassostrea corteziensis, from four coastal lagoons (Altata, AL; Macapule, ML; Navachiste, NL; El Colorado, ECL) in the Southeast Gulf of California, were seasonally evaluated (summer 2019-spring 2020). The order of magnitude of potentially toxic elements concentrations in the soft tissue in both oyster species and at all sites was Zn > Fe > Cu > As > Cd > Pb. Cadmium, Cu, Pb, and Zn exceeded the maximum permissible limits in more than one sampling site. The highest concentrations (mg kg-1, wet weight) of As (4.2 ± 1.1, spring) and Cd (3.3 ± 0.7, autumn) were registered in S. palmula et al. and NL sampling sites, respectively. Crassostrea corteziensis presented higher levels of Cu (40.5 ± 6.7, spring), Pb (2.0 ± 0.4, spring), and Zn (96.9 ± 20.4, spring) in ECL and Fe (62.2 ± 25.4, autumn) in ML. The hazard quotient (HQ) values exceeded the safe level of 1 for Cd in S. palmula and C. corteziensis in NL for children (~ 16 kg weight). In addition, in children, the hazard index (HI) values in both species of oysters ranged from 0.7 to 2.1 and 0.6 to 1.9, respectively. On the other hand, the intake of the studied elements through the consumption of oysters would not induce adverse effects to human health (men and women weighing 70 and 60 kg, respectively); HQ and HI values were < 1.

The CB1 cannabinoid receptor regulates autophagy in the tibialis anterior skeletal muscle in mice

The endocannabinoid system (ECS) regulates energy metabolism, has been implicated in the pathogenesis of metabolic diseases and exerts its actions mainly through the type 1 cannabinoid receptor (CB1). Likewise, autophagy is involved in several cellular processes. It is required for the normal development of muscle mass and metabolism, and its deregulation is associated with diseases. It is known that the CB1 regulates signaling pathways that control autophagy, however, it is currently unknown whether the ECS could regulate autophagy in the skeletal muscle of obese mice. This study aimed to investigate the role of the CB1 in regulating autophagy in skeletal muscle. We found concomitant deregulation in the ECS and autophagy markers in high-fat diet-induced obesity. In obese CB1-KO mice, the autophagy-associated protein LC3 II does not accumulate when mTOR and AMPK phosphorylation levels do not change. Acute inhibition of the CB1 with JD-5037 decreased LC3 II protein accumulation and autophagic flux. Our results suggest that the CB1 regulates autophagy in the tibialis anterior skeletal muscle in both lean and obese mice.

Replenishment of myeloid-derived suppressor cells (MDSCs) overrides CR-mediated protection against tumor growth in a murine model of triple-negative breast cancer.

Caloric restriction (CR) is the leading non-pharmacological intervention to delay induced and spontaneous tumors in pre-clinical models. These effects of CR are largely attributed to canonical inhibition of pro-growth pathways. However, our recent data suggest that CR impairs primary tumor growth and cancer progression in the murine 4T1 model of triple negative breast cancer (TNBC), at least in part, through reduced frequency of the myeloid-derived suppressor cells (MDSC). In the present study, we sought to determine whether injection of excess MDSCs could block regression in 4T1 tumor growth and metastatic spread in BALB/cJ female mice undergoing daily CR. Our findings show that MDSC injection impeded CR-mediated protection against tumor growth without increasing lung metastatic burden. Overall, these results reveal that CR can slow cancer progression by affecting immune suppressive cells.Impact statement: Inoculation of MDSCs from donor mice effectively impedes the ability of calorie restriction to protect against primary tumor growth without impacting lung metastatic burden in recipient animals.

Hydrogen sulfide disrupts insulin-induced glucose uptake in L6 skeletal muscle cells.

Hydrogen sulfide (H2S) has been known for its toxicity. However, recent studies have focused on the mechanisms involved in endogenous production and function. To date, the H2S role in insulin signaling and glucose homeostasis is unclear. This uncertainty is even more evident in skeletal muscle, a physiological niche highly relevant for regulating glycemia in response to insulin. This study aimed to investigate the role of H2S on insulin signaling and glucose uptake in the L6 skeletal muscle cell line. We evaluated the endogenous synthesis with the fluorescent dye, 7-azido-4-methyl coumarin (7-AzMC). Glucose restriction-induced an increase in the endogenous levels of H2S, likely through stimulation of cystathionine γ-lyase activity, as its specific inhibitor, PAG (5 mM) prevented this increase, and mRNA levels of CSE decreased with glucose and amino acid restriction. Exogenous H2S reduced insulin-induced glucose uptake at 0.5 up to 24 h, an effect dissociated from the level of Akt phosphorylation. Our results show that glucose restriction induces endogenous production of H2S via CSE. In addition, H2S disrupts insulin-induced glucose uptake independent of the Akt pathway. These results suggest that H2S antagonism over insulin-induced glucose uptake could help maintain the plasmatic glucose levels in conditions that provoke hypoglycemia, which could serve as an H2S-regulated mechanism for maintaining glucose plasmatic levels through the inhibition of the skeletal muscle insulin-depended glucose uptake.

Pandemic Effects and Gluten-Free Diet: An Adherence and Mental Health Problem.

The COVID-19 pandemic has been present for many months, influencing diets such as the gluten-free diet (GFD), which implies daily challenges even in non-pandemic conditions. Persons following the GFD were invited to answer online ad hoc and validated questionnaires characterizing self-perceptions of the pandemic, current clinical condition, dietary characteristics, adherence to GFD, anxiety, and depression. Of 331 participants, 87% experienced shortage and higher cost of food and 14.8% lost their jobs. Symptoms increased in 29% and 36.6% failed to obtain medical help. Although 52.3% increased food preparation at home and purchased alternative foodstuffs, 53.8% had consumed gluten-containing foods. The Health Eating Index was intermediate/"needs improvement" (mean 65.6 ± 13.3 points); in 49.9% (perception) and 44.4% (questionnaire), adherence was "bad". Anxiety and depression scores were above the cutoff in 28% and 40.4%, respectively. Adherence and mental health were strongly related. The likelihood of poor adherence was 2.3 times higher (p < 0.004) in participants declaring that pandemic altered GFD. Those suffering depressive symptoms were 1.3 times more likely to have poor adherence (p < 0.000). Depression and faulty GFD (mandatory for treatment) appear, affecting a high proportion of participants, suggesting that support measures aimed at these aspects would help improve the health condition of people that maintain GFD. Comparisons of data currently appearing in the literature available should be cautious because not only cultural aspects but conditions and timing of data collection are most variable.

Modified Talk Test: a Randomized Cross-over Trial Investigating the Comparative Utility of Two "Talk Tests" for Determining Aerobic Training Zones in Overweight and Obese Patients.

BACKGROUND: To validate the traditional talk test (TTT) and an alternative talk test (ATT; using a visual analog scale) in overweight/obese (OW-OB) patients and to establish its accuracy in determining the aerobic training zones. METHODS: We recruited 19 subjects aged 34.9 ± 6.7 years, diagnosed with overweight/obesity (BMI 31.8 ± 5.7). Every subject underwent incremental cycloergometric tests for maximal oxygen consumption, and TTT in a randomized order. At the end of each stage during the TTT, each subject read out loud a 40 words text and then had to identify the comfort to talk in two modalities: TTT which consisted in answering "Yes," "I don't know," or "No" to the question Was talking comfortable?, or ATT through a 1 to 10 numeric perception scale (visual analog scale (VAS)). The magnitude of differences was interpreted in comparison to the smallest worthwhile change and was used to determine agreement. RESULTS: There was an agreement between the power output at the VAS 2-3 of ATT and the power output at the ventilatory threshold 1 (VT1) (very likely equivalent; mean difference - 1.3 W, 90% confidence limit (CL) (- 8.2; 5.6), percent chances for higher/similar/lower values of 0.7/99.1/0.2%). Also, there was an agreement between the power output at the VAS 6-7 of ATT and the power output at the ventilatory threshold 2 (VT2) (very likely equivalent; mean difference 11.1 W, 90% CL (2.8; 19.2), percent chances for higher/similar/lower values of 0.0/97.6/2.4%). CONCLUSIONS: ATT is a tool to determine exercise intensity and to establish aerobic training zones for exercise prescription in OW-OB patients.

Moderate Aerobic Exercise Training Prevents the Augmented Hepatic Glucocorticoid Response Induced by High-Fat Diet in Mice.

Glucocorticoids (GCs) are critical regulators of energy balance. Their deregulation is associated with the development of obesity and metabolic syndrome. However, it is not understood if obesity alters the tissue glucocorticoid receptor (GR) response, and moreover whether a moderate aerobic exercise prevents the alteration in GR response induced by obesity. METHODS: To evaluate the GR response in obese mice, we fed C57BL6J mice with a high-fat diet (HFD) for 12 weeks. Before mice were sacrificed, we injected them with dexamethasone. To assess the exercise role in GR response, we fed mice an HFD and subjected them to moderate aerobic exercise three times a week. RESULTS: We found that mice fed a high-fat diet for 12 weeks developed hepatic GC hypersensitivity without changes in the gastrocnemius or epididymal fat GR response. Therefore, moderate aerobic exercise improved glucose tolerance, increased the corticosterone plasma levels, and prevented hepatic GR hypersensitivity with an increase in epididymal fat GR response. CONCLUSION: Collectively, our results suggest that mice with HFD-induced obesity develop hepatic GR sensitivity, which could enhance the metabolic effects of HFD in the liver. Moreover, exercise was found to be a feasible non-pharmacological strategy to prevent the deregulation of GR response in obesity.

ß-Hydroxybutyrate Increases Exercise Capacity Associated with Changes in Mitochondrial Function in Skeletal Muscle.

ß-hydroxybutyrate is the main ketone body generated by the liver under starvation. Under these conditions, it can sustain ATP levels by its oxidation in mitochondria. As mitochondria can modify its shape and function under different nutritional challenges, we study the chronic effects of ß-hydroxybutyrate supplementation on mitochondrial morphology and function, and its relation to exercise capacity. Male C57BL/6 mice were supplemented with ß-hydroxybutyrate mineral salt (3.2%) or control (CT, NaCl/KCl) for six weeks and submitted to a weekly exercise performance test. We found an increase in distance, maximal speed, and time to exhaustion at two weeks of supplementation. Fatty acid metabolism and OXPHOS subunit proteins declined at two weeks in soleus but not in tibialis anterior muscles. Oxygen consumption rate on permeabilized fibers indicated a decrease in the presence of pyruvate in the short-term treatment. Both the tibialis anterior and soleus showed decreased levels of Mitofusin 2, while electron microscopy assessment revealed a significant reduction in mitochondrial cristae shape in the tibialis anterior, while a reduction in the mitochondrial number was observed only in soleus. These results suggest that short, but not long-term, ß­hydroxybutyrate supplementation increases exercise capacity, associated with modifications in mitochondrial morphology and function in mouse skeletal muscle.

Exercise regulates lipid droplet dynamics in normal and fatty liver.

Lipids droplets (LD) are dynamics organelles that accumulate neutral lipids during nutrient surplus. LD alternates between periods of growth and consumption through regulated processes including as de novo lipogenesis, lipolysis and lipophagy. The liver is a central tissue in the regulation of lipid metabolism. Non-Alcoholic Fatty Liver Diseases (NAFLD) is result of the accumulation of LD in liver. Several works have been demonstrated a positive effect of exercise on reduction of liver fat. However, the study of the exercise on liver LD dynamics is far from being understood. Here we investigated the effect of chronic exercise in the regulation of LD dynamics using a mouse model of high fat diet-induced NAFLD. Mice were fed with a high-fat diet or control diet for 12 weeks; then groups were divided into chronic exercise or sedentary for additional 8 weeks. Our results showed that exercise reduced fasting glycaemia, insulin and triacylglycerides, also liver damage. However, exercise did not affect the intrahepatic triacylglycerides levels and the number of LD but reduced their size. In addition, exercise decreased the SREBP-1c levels, without changes in lipolysis, mitochondrial proteins or autophagy/lipophagy markers. Unexpectedly in the control mice, exercise increased the number of LD, also PLIN2, SREBP-1c, FAS, ATGL, HSL and MTTP levels. Our findings show that exercise rescues the liver damage in a model of NAFLD reducing the size of LD and normalizing protein markers of de novo lipogenesis and lipolysis. Moreover, exercise increases proteins associated to LD dynamics in the control mice.

Fuzzy Evaluation of Pharmacokinetic Models.

Population pharmacokinetic (PopPK) models allow researchers to predict and analyze drug behavior in a population of individuals and to quantify the different sources of variability among these individuals. In the development of PopPK models, the most frequently used method is the nonlinear mixed effect model (NLME). However, once the PopPK model has been developed, it is necessary to determine if the selected model is the best one of the developed models during the population pharmacokinetic study, and this sometimes becomes a multiple criteria decision making (MCDM) problem, and frequently, researchers use statistical evaluation criteria to choose the final PopPK model. The used evaluation criteria mentioned above entail big problems since the selection of the best model becomes susceptible to the human error mainly by misinterpretation of the results. To solve the previous problems, we introduce the development of a software robot that can automate the task of selecting the best PopPK model considering the knowledge of human expertise. The software robot is a fuzzy expert system that provides a method to systematically perform evaluations on a set of candidate PopPK models of commonly used statistical criteria. The presented results strengthen our hypothesis that the software robot can be successfully used to evaluate PopPK models ensuring the selection of the best PopPK model.

Evaluation of using two metabolites of Vitamin D3 with phytase in the diet of laying hens finishing their productive cycle / Evaluación del empleo de dos metabolitos de vitamina D3 con fitasa en la dieta de gallinas ponedoras finalizando el ciclo productivo / Avaliação da utilização de dois metabolitos da vitamina D3 com fitasse na dieta de galinhas poedeiras finalizando o ciclo produtivo

The effect of supplementing the diet with two sources of vitamin D3, 1α-hidroxycholecalciferol (1α-OH-D3) and 25-hidroxycholecalciferol (25-OH-D3), in the presence of phytase, on the productive indicators, the bone mineral composition and the external quality of the eggs of comercial laying hens during weeks 55 to 68 of life. A total of 360 Lohman Brown hens were used, distributed between four treatments with six replicates per treatment and 15 birds per replicate. The diets were: T1 (diet with 50g ton-1 of phytose), T2 (same as T1 plus 12.5g ton-1 of 1α-OH-D3 without considering the phosphorus and calcium contributions), T3 (same as T1 with the addition of 12. 5g ton-1 considering a liberation of 0.05% of available phosphorus and calcium ), and T4 (same as T1 with the addition of 5.52g ton-1 of 25-OH-D3 considering a liberation of 0.05% of available phosphorus and calcium). All birds had free Access to wáter and food according to recomendations for comercial lines. The variables laying percentage, cumulative conversión, egg quality, Shell minerals, percentage of Shell in the egg, egg density, and bone minerals were not significantly influenced (p>0.05) by the source or type of inclusión of vitamin D3. However, the use of vitamin 1α-OH-D3 in a matrix showed a net economic benefit, representing the lowest production cost and highest income for egg sales. In future research with laying hens, it is necessary to check the level of inclusión of vitamin D3 as well as the concentration of calcium in the diet.

Se evaluó el efecto de la suplementación de dos fuentes de vitamina D3 , 1α-hidroxicolecalciferol (1α-OH-D3,) y 25-hidroxicolecalciferol (25-OH-D3 ), en la presencia de fitasa, sobre los indicadores productivos, la composición mineral ósea y la calidad externa del huevo de gallinas de postura comercial durante las semanas 55 a la 68 de vida Se utilizaron 360 gallinas Lohmann Brown, distribuidas entre cuatro tratamientos con seis réplicas por tratamiento y quince aves por replica. Las dietas fueron: T1 (dieta con 50 g ton-1 de fitasa), T2 (igual a T1 más la adición de 12,5 g ton-1 de 1α-OH-D3 sin valorar los aportes de calcio y fósforo), T3 (igual a T1 con la adición de 12,5 g ton-1 de 1α-OH-D3 considerando una liberación de 0,05% del fósforo y calcio disponible), T4 (igual a T1 con la adición de 5,52 g ton-1 de 25-OH-D3 considerando una liberación de 0,05% del fósforo y calcio disponible). Todas las aves tuvieron acceso a agua y alimento de acuerdo a la recomendación para la línea comercial. Las variables porcentaje de postura, conversión acumulada, calidad de huevo, minerales en cáscara, % de cáscara en huevo, densidad de huevos y minerales en huesos no fueron influenciadas significativamente (p>0,05) por la fuente ni el tipo de inclusión de la vitamina D3 . Sin embargo, el uso de la vitamina 1α-OH-D3 matrizada mostró un beneficio económico neto, representado en menor costo de producción y mayor ingreso por ventas de huevo. En futuras investigaciones con ponedoras, es necesario verificar tanto el nivel de inclusión de vitamina D3 como la concentración de calcio de la dieta..

Avaliou-se o efeito da suplementação de dois fontes de vitamina D3 , 1α-hidroxicolecalciferol (1α-OH-D3,) e 25-hidroxicolecalciferol (25-OH-D3 ), na presença de fitasse sobre os indicadores produtivos, a composição mineral óssea e a qualidade externa do ovo de galinhas poedeiras comerciais entre as semanas 55 e 68. Utilizaram-se 362 galinhas Lohman Brown, distribuídas em quatro tratamentos com seis réplicas por tratamento e 15 aves por replica. As dietas foram: T1 (dieta com 50 g ton-1 de fitasse), T2 (igual a T1 mais a adição de 12,5 g ton-1 de 1α-OH-D3 sem valorar os aportes de cálcio e fósforo), T3 (igual a T1 com a adição de 12,5 g ton-1 de 1α-OH-D3 considerando uma liberação de 0,05% de fósforo e cálcio disponível), T4 (igual a T1 com a adição de 5,52 g ton-1 de 25-OH-D3 considerando uma liberação de 0,05% do fósforo e cálcio disponível). Todas as aves tiveram aceso a agua e alimento de acordo a recomendação para linha comercial. As variáveis: porcentagem de postura, conversão acumulada, qualidade do ovo, minerais em casca, % de casca em ovo, densidade do ovo e minerais em ossos não foram influenciadas significativamente (p>0,05) pela fonte nem pelo tipo de inclusão de vitamina D3 . Embora, a utilização da vitamina 1α-OH-D3 matrizada mostrou um benefício económico neto, representado pelo menor custo de produção e maior ingresso por ventas de ovos. Em futuras pesquisas com poedeiras, é necessário verificar tanto o nível de inclusão de vitamina D3 quanto a concentração de cálcio na dieta..

Mecanismos de acción de la vitamina D3, 1-α-hidroxicolecalciferol (1-α-OH-D3,) y 25-hidroxicolecalciferol (25-OH-D3) en gallinas de postura comercial / Mode of action of vitamin D3, 1-α-hydroxycholecalciferol (1-α-OH-D3) and 25-hydroxycholecalciferol (25-OH-D3) in commercial laying hens / Mecanismos de ação da vitamina D3, 1-α-hidroxicolecalciferol (1-α-OH-D3) e 25-hidroxicolecalciferol (25-OH-D3) em galinhas poedeiras

Resumen Las aves de corral comúnmente reciben una alimentación a base de maíz y soya y mucho del fósforo presente en estas plantas se encuentra en forma de un complejo fítico que es relativamente insoluble en el sistema digestivo de las aves y no es disponible para su utilización. Los compuestos 1-α-hidroxicolecalciferol (1-α-OH-D3) y 25-hidroxicolecalciferol (25-OH-D3), metabolitos de la vitamina D, han sido usados para incrementar la utilización del fósforo fítico, mejorar el desempeño y la mineralización ósea y disminuir los problemas de discondroplasia tibial. La presente revisión busca proveer información científica referente al empleo de metabolitos de la vitamina D3 como la 1-α-hidroxicolecalciferol y la 25-hidroxicolecalciferol, precursoras de la 25 (OH)2 D3, que es la forma metabólicamente activa de la vitamina D3 en gallinas ponedoras y pollos productores de carne.

Abstract Poultry are commonly fed diets based on corn and soybeans. Much of the phosphorus present in these feedstuffs is in the form of a phytate complex. Phytate phosphorus is relatively insoluble in the digestive tract of birds and mostly not absorbed. 1-α-hydroxycholecalciferol (1-α-OH-D3) and 25- hydroxycholecalciferol (25-OH-D3), both vitamin D metabolites, have been used to increase the utilization of phytate phosphorus, improve performance and bone mineralization, and decrease tibial dyschondroplasia. The present review aims to provide scientific information regarding the use of vitamin D3 metabolites such as 1 alpha-hydroxycholecalciferol and 25-hydroxycholecalciferol. Both of them are precursors for 25 (OH)2 D3, which is the metabolically active form of vitamin D3 in laying hens and broilers.

Resumo As galinhas especializadas na produção de ovos comumente recebem uma dieta à base de milho e soja. Muito do fósforo presente nesses alimentos se encontra em forma de um complexo fítico que é relativamente insolúvel no sistema digestivo das aves e não é disponível para sua utilização. Os compostos 1α-hidroxicolecalciferol (1-α-OH-D3) e a 25-hidroxicolecalciferol (25-OH-D3), metabolitos da vitamina D, tem sido utilizados para incrementar a utilização do fosforo fítico, melhorar o desempenho e a mineralização óssea e diminuir os problemas de discondroplasia tibial. A presente revisão pretende prover informação cientifica referente ao emprego de metabolitos da vitamina D3 como a 1-α-hidroxicolecalciferol e a 25-hidroxicolecalciferol, precursoras da 25 (OH)2 D3, que é a forma metabolicamente ativa da vitamina D3 em galinhas poedeiras e frangos de corte.

Influência do exercício físico na cognição: uma atualização sobre mecanismos fisiológicos / Influence of physical exercise on cognition: an update on physiological mechanisms / Influencia del ejercicio físico en la cognición: una actualización sobre mecanismos fisiológicos

Embora um crescente corpo de literatura corrobore o papel benéfico do exercício sobre a cognição, não há consenso sobre os mecanismos que norteiam as adaptações cerebrais agudas e crônicas ao exercício. A presente revisão narrativa tem como objetivo apresentar e discutir os mecanismos pelos quais o exercício afeta o desempenho cognitivo. Agudamente, especula-se que os efeitos do exercício sobre a resposta cognitiva sejam mediados por aumentos no fluxo sanguíneo cerebral e, por conseguinte, no aporte de nutrientes, ou por um aumento na atividade de neurotransmissores. Cronicamente, especula-se que o exercício possa promover adaptações em estruturas cerebrais e plasticidade sináptica que culminariam com melhoras cognitivas. Tais hipóteses são discutidas à luz das evidências científicas disponíveis, tanto em modelos animais quanto em humanos.

Although a growing body of literature has supported the beneficial role of exercise on cognition, there is no consensus on the mechanisms underlying acute and chronic cerebral adaptations to exercise. The present review aims to present and discuss the mechanisms by which exercise affects cognitive performance. It has been speculated that the acute effects of exercise on cognitive response may be mediated by increases in cerebral blood flow and, hence, in nutrient availability, or by increases in neurotransmitter activity. It has been also postulated that chronic exercise may induce adaptations in brain structures and the synaptic plasticity, which would result in cognitive improvements. These hypotheses are discussed in light of available scientific evidence in animal models and humans.

Aunque un creciente cuerpo de literatura corrobore el papel benéfico del ejercicio sobre la cognición, no hay consenso sobre los mecanismos que nortean las adaptaciones cerebrales agudas y crónicas al ejercicio. La presente revisión narrativa tiene como objetivo presentar y discutir los mecanismos por los cuales el ejercicio afecta el desempeño cognitivo. Agudamente, se especula que los efectos del ejercicio sobre la respuesta cognitiva sean mediados por aumentos en el flujo sanguíneo cerebral y, por consiguiente, en el aporte de nutrientes, o por un aumento en la actividad de neurotransmisores. Crónicamente, se especula que el ejercicio pueda promover adaptaciones en estructuras cerebrales y plasticidad sináptica que culminarían con mejoras cognitivas. Tales hipótesis son discutidas a la luz de las evidencias científicas disponibles, tanto en modelos animales como en humanos.

Determination of pentachlorophenol and tribromophenol in sawdust by ultrasound-assisted extraction and MEKC.

An ultrasonic bar-assisted extraction and CE separation procedure for the determination of pentachlorophenol (PCP) and 2,4,6-tribromophenol (TBP) residues in sawdust was developed and applied. For this purpose, micellar electrokinetic capillary chromatography (MEKC) was used and compared with a GC/MS methodology. This methodology allowed the quantification of PCP and TBP in a concentration range of 2.5-12.0 mg/kg for TBP and 2.8-12.0 mg/kg for PCP. Different sample treatment processes were evaluated in order to extract these compounds from sawdust. Better results were obtained when the residues were extracted with ultrasound-assisted hexane, filtered, evaporated, dissolved in Na(2)CO(3), and injected into the CE equipment. The optimal option for GC/MS was extraction with Na(2)CO(3 )followed by a derivation using acetic anhydride and liquid-liquid extraction with hexane. This method allowed the quantification of TBP and PCP in sawdust in a concentration range of 0.19-12.00 mg/kg and 0.14-12.00 mg/kg, respectively. The CE method was compared with the GC/MS as reference method. The results were shown to be statistically similar by both methods for PCP as well as for TBP.

Función gustativa con respecto a la edad / Taste sensation related to age

ANTECEDENTES: Las variaciones en la percepción gustativa que se presentan de acuerdo con la edad, se definen como un proceso fisiológico en el cual hay una disminución en la cantidad y calidad de los receptores gustativos. Tales cambios se manifiestan como disgeusia, hipergeusia, ageusia e hipogeusia, ante la estimulación de los cuatros sabores básicos. OBJETIVO: Identificar los cambios que se presentan en la función gustativa asociados al proceso de envejecimiento. METODO: Se realizó un estudio observacional analítico en cuatro pacientes entre los 20 y 60 años de edad distribuidos en cuatro grupos, cada uno de los cuales degustó cuatro sabores (salado, dulce, amargo y ácido) en tres concentraciones diferentes, a partir de una concentración mínima perceptible hallada previamente, para describir su sabor e intensidad en una escala numérica entre 1 y 5. RESULTADOS: Con una significación estadística del 0.5 los hallazgos muestran que el grupo de 20-30 años presentó el menor número de alteraciones en la percepción gustativa, el grupo entre 31-40 años mostró una mayor aparición de éstas, el grupo entre 51-60 años mostró alteraciones en la totalidad de los sujetos, alteraciones que podrían ser más de una y diferentes de acuerdo con el estímulo gustativo usado. CONCLUSIONES: Tanto los pacientes jóvenes como los mayores presentaron alteraciones en la percepción gustativa; además, con el aumento de la edad se encontró hipogeusia respecto de los sabores salado y amargo, manteniéndose estable para los sabores ácido y dulce. Con el aumento de la edad no hubo hipogeusia (incremento para la percepción ante ningún estímulo).