Dietary docosahexaenoic acid and eicosapentaenoic acid influence liver triacylglycerol and insulin resistance in rats fed a high-fructose diet.

This study aimed to examine the benefits of different amounts of omega-3 (n-3) polyunsaturated fatty acids from fish oil (FO) on lipid metabolism, insulin resistance and gene expression in rats fed a high-fructose diet. Male Wistar rats were separated into two groups: Control (C, n = 6) and Fructose (Fr, n = 32), the latter receiving a diet containing 63% by weight fructose for 60 days. After this period, 24 animals from Fr group were allocated to three groups: FrFO2 (n = 8) receiving 63% fructose and 2% FO plus 5% soybean oil; FrFO5 (n = 8) receiving 63% fructose and 5% FO plus 2% soybean oil; and FrFO7 (n = 8) receiving 63% fructose and 7% FO. Animals were fed these diets for 30 days. Fructose led to an increase in liver weight, hepatic and serum triacylglycerol, serum alanine aminotransferase and HOMA1-IR index. These alterations were reversed by 5% and 7% FO. FO had a dose-dependent effect on expression of genes related to hepatic ß-oxidation (increased) and hepatic lipogenesis (decreased). The group receiving the highest FO amount had increased markers of oxidative stress. It is concluded that n-3 fatty acids may be able to reverse the adverse metabolic effects induced by a high fructose diet.

[Assessment, evaluation and nutrition monitoring in older people living in a rest home]. / Avaliação e acompanhamento nutricional em idosos de uma instituição de longa permanência.

Institutionalized elderly have an increased risk of changes in nutritional status, therefore sensitive parameters are necessary for the identification of changes in nutritional status. The aim of this study was to evaluate parameters for analysis of the nutritional status of institutionalized elderly in a period of three months by means of biochemical and anthropometric measurements. Eighty one volunteers were selected, with 78 ± 10 years old and 53% female. Anthropometric data showed that the variables body mass index, weight, fat mass, and phase angle of the institutionalized elderly in three months decreased with significant difference between the assessments. Among all the biochemical and anthropometric measurements, body mass index, weight, fat mass, phase angle and blood fat were the indicators of nutritional assessment that identified early changes and nutritional risks of institutionalized elderly in three months. It is noteworthy that the early evaluation of nutritional indicators can prevent nutritional risk among elderly in living in rest homes.

Choline supplementation protects against liver damage by normalizing cholesterol metabolism in Pemt/Ldlr knockout mice fed a high-fat diet.

Dietary choline is required for proper structure and dynamics of cell membranes, lipoprotein synthesis, and methyl-group metabolism. In mammals, choline is synthesized via phosphatidylethanolamine N-methyltransferase (Pemt), which converts phosphatidylethanolamine to phosphatidylcholine. Pemt(-/-) mice have impaired VLDL secretion and developed fatty liver when fed a high-fat (HF) diet. Because of the reduction in plasma lipids, Pemt(-/-)/low-density lipoprotein receptor knockout (Ldlr(-/-)) mice are protected from atherosclerosis. The goal of this study was to investigate the importance of dietary choline in the metabolic phenotype of Pemt(-/-)/Ldlr(-/-) male mice. At 10-12 wk of age, Pemt(+/+)/Ldlr(-/-) (HF(+/+)) and half of the Pemt(-/-)/Ldlr(-/-) (HF(-/-)) mice were fed an HF diet with normal (1.3 g/kg) choline. The remaining Pemt(-/-)/Ldlr(-/-) mice were fed an HF diet supplemented (5 g/kg) with choline (HFCS(-/-) mice). The HF diet contained 60% of calories from fat and 1% cholesterol, and the mice were fed for 16 d. HF(-/-) mice lost weight and developed hepatomegaly, steatohepatitis, and liver damage. Hepatic concentrations of free cholesterol, cholesterol-esters, and triglyceride (TG) were elevated by 30%, 1.1-fold and 3.1-fold, respectively, in HF(-/-) compared with HF(+/+) mice. Choline supplementation normalized hepatic cholesterol, but not TG, and dramatically improved liver function. The expression of genes involved in cholesterol transport and esterification increased by 50% to 5.6-fold in HF(-/-) mice when compared with HF(+/+) mice. Markers of macrophages, oxidative stress, and fibrosis were elevated in the HF(-/-) mice. Choline supplementation normalized the expression of these genes. In conclusion, HF(-/-) mice develop liver failure associated with altered cholesterol metabolism when fed an HF/normal choline diet. Choline supplementation normalized cholesterol metabolism, which was sufficient to prevent nonalcoholic steatohepatitis development and improve liver function. Our data suggest that choline can promote liver health by maintaining cholesterol homeostasis.

Methylenetetrahydrofolate reductase gene polymorphism and serum homocysteine levels in nonalcoholic fatty liver disease.

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder characterized by hepatic fat accumulation in the absence of alcohol consumption. Hyperhomocysteinemia is considered an independent risk factor for liver diseases, and the genetic polymorphisms C677T and A1298C in the MTHFR gene have been linked to hyperhomocysteinemia. The purpose of this study was to investigate serum homocysteine (Hcy) concentrations and the MTHFR C677T and A1298C polymorphisms as risk factors for the development of NAFLD. METHODS: One hundred and thirty-four Brazilian patients with biopsy-proven NAFLD and 134 healthy controls were recruited. The MTHFR C677T and A1298C polymorphisms were detected through polymerase chain reaction restriction fragment length polymorphism. Serum Hcy levels were determined by chemiluminescence. RESULTS: Serum Hcy levels were higher in NAFLD patients as compared to control subjects, but there were no differences between patients with steatosis and nonalcoholic steatohepatitis. The NAFLD and control groups did not differ in genotypic and allelic frequencies of the MTHFR C677T and A1298C polymorphisms, either. Elevated plasma Hcy levels were positively correlated with age in the NAFLD subjects. CONCLUSION: The MTHFR C677T and A1298C polymorphisms are not genetic risk factors for the development of NAFLD. Higher Hcy levels exist in NAFLD subjects, but they are not associated with liver disease severity.

Polymorphism C1420T of Serine hydroxymethyltransferase gene on maternal risk for Down syndrome.

Recent researches have investigated the factors that determine the maternal risk for Down syndrome (DS) in young woman. In this context, some studies have demonstrated the association between polymorphisms in genes involved on folate metabolism and the maternal risk for DS. These polymorphisms may result in abnormal folate metabolism and methyl deficiency, which is associated with aberrant chromosome segregation leading to trisomy 21. In this study, we analyzed the influence of the polymorphism C1420T in Serine hydroxymethyltransferase (SHMT) gene on maternal risk for DS and on metabolites concentrations of the folate pathway (serum folate and plasma homocysteine and methylmalonic acid). The study group was composed by 105 mothers with DS children (case group) and 185 mothers who had no children with DS (control group). The genotype distribution did not show significant statistical difference between case and control mothers (P = 0.24) however a protective effect between genotypes CC (P = 0.0002) and CT (P < 0.0001) and maternal risk for DS was observed. Furthermore, the SHMT C1420T polymorphism (rs1979277) does not affect the concentration of metabolites of folate pathway in our DS mothers. In conclusion, our data showed a protective role for the genotypes SHMT CC and CT on maternal risk for DS. The concentrations of metabolites of folate pathway did not differ significantly between the genotypes SHMT.

Carnitine supplementation effects on nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress.

Previous studies have demonstrated that exercise stress increases oxidative stress in rats. However, antioxidant supplement therapy effects on reactive oxygen substances are conflicting. We evaluated the effects of carnitine on renal nonenzymatic antioxidants in young rats submitted to exhaustive exercise stress. Wistar rats were divided into 3 groups: (a) control group (not submitted to exercise stress), (b) exercise stress group, and (c) exercise stress and carnitine group. The rats from group 3 were treated with gavage administration of 1 ml of carnitine (5 mg·kg⁻¹) for 7 consecutive days. The animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for reactive substances to thiobarbituric acid by malondialdehyde (MDA), reduced glutathione (GSH), and vitamin-E levels. Carnitine treatment attenuated MDA increase caused by exercise stress (1: 0.16 ± 0.02 vs. 2: 0.34 ± 0.07 vs. 3: 0.1 ± 0.01 mmmol per milligram of protein; p < 0.0001). It also increased the renal levels of GSH (1: 23 ± 4 vs. 2: 23 ± 2 vs. 3: 58 ± 9 µmol per gram of protein; p < 0.0001); however, it did not change renal vitamin E (1: 24 ± 5 vs. 2: 27 ± 1 vs. 3: 28 ± 5 µM per gram of tissue; p < 0.001). In conclusion, carnitine improved oxidative stress and partially improved the nonenzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

Light and moderate doses of ethanol in chemical carcinogenesis of the colon in rats.

The aberrant crypt foci (ACF), cyclooxygenase 2 (COX-2), and the proliferating cell nuclear antigen (PCNA) are putative biomarkers for colon cancer. To study the association between light (1 g of ethanol/kg bw) and moderate (3 g of ethanol/kg bw) doses of ethanol with the chemical carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), Wistar rats were divided into 6 groups. The colon fragments were collected for histochemical and immunohistochemical analyses, and the liver samples were collected for oxidative stress analysis, with products of lipid peroxidation (malondialdehyde), antioxidant enzymes (glutathione), and vitamin E. The association of light and moderate doses of ethanol with MNNG did not present differences in the oxidative parameters. However, a reduction in vitamin E levels in the carcinogen groups was observed. The association induced a reduction of the COX-2 and PCNA expression. The number of ACF in the group that received a light dose of ethanol had lower rates, while the group that received a moderate dose had the highest rates compared to the control MNNG, demonstrating that the light dose of ethanol could have a protective effect, while the moderate dose could represent a risk during chemical carcinogenesis in rats.

Creatine supplementation reduces increased homocysteine concentration induced by acute exercise in rats.

The aim of this study was to evaluate the effect of creatine supplementation on homocysteine (Hcy) metabolism after acute aerobic and anaerobic exercise. A total of 112 Wistar rats were divided into four groups: aerobic exercise (A), aerobic exercise plus creatine supplementation (ACr), anaerobic exercise (An), and anaerobic exercise plus creatine-supplemented (AnCr). Creatine supplementation consisted of the addition of 2% creatine monohydrate to the diet. After 28 days, the rats performed an acute moderate aerobic exercise bout (1 h swimming with 4% of total body weight load) or an acute intense anaerobic exercise bout (6 × 30-s vertical jumps into the water with a 30-s rest between jumps, with 50% of total body weight load). The animals were killed before (pre) and at 0, 2, and 6 h (n = 8) after acute exercise. Plasma Hcy concentration increased significantly (P < 0.05) up to 2 h after anaerobic exercise (An group: pre 8.7 ± 1.2, 0 h 13.2 ± 2.3, 2 h 13.5 ± 4.2, and 6 h 12.1 ± 2.2, µmol/l). The same did not occur in acute aerobic exercised animals. Nevertheless, creatine supplementation significant decreased (P < 0.05) homocysteine concentration independent of exercise intensity (AnCr group: pre 17%, 0 h 80%, 2 h 107%, and 6 h 48%; ACr group: pre 17%, 0 h 19%, 2 h 28%, and 6 h 27%). Increased S-adenosylhomocysteine was also found in the An group. In conclusion, acute intense anaerobic exercise increased plasma Hcy concentration. On the other hand, creatine supplementation decreased plasma Hcy independent of exercise intensity.

What is the meaning of homocysteine in patients on dialysis?

OBJECTIVE: To evaluate the determinants of total plasma homocysteine levels and their relations with nutritional parameters, inflammatory status, and traditional risk factors for cardiovascular disease in renal failure patients on dialysis treatment. DESIGN: The study was conducted on 70 clinically stable patients, 50 of them on hemodialysis (70% men; 55.3 ± 14.5 years) and 20 on peritoneal dialysis (50% men; 62 ± 13.7 years). Patients were analyzed in terms of biochemical parameters (serum lipids, creatinine, homocysteine [Hcy], creatine-kinase [Ck], folic acid, and vitamin B(12)), anthropometric data, markers of inflammatory status (tumor necrosis factor-alpha, C-reactive protein, interleukin-6), and adapted subjective global assessment. RESULTS: The total prevalence of hyperhomocysteinemia (>15 µmol/L) was 85.7%. Plasma folic acid and plasma vitamin B(12) were within the normal range. Multiple regression analysis (r(2) = 0.20) revealed that the determinants of total Hcy were type of dialysis, creatinine, Ck, folic acid, and total cholesterol. Hcy was positively correlated with albumin and creatinine and negatively correlated with total cholesterol, high density lipoprotein cholesterol, folic acid, and vitamin B(12). CONCLUSIONS: The determinants of total Hcy in the study sample were type of dialysis, creatinine, Ck, folic acid, and total cholesterol. Evidently, the small sample size might have had an effect on the statistical analyses and further studies are needed. However, Hcy in patients on dialysis treatment may not have the same effect as observed in the general population. In this respect, the association between malnutrition and inflammation may be a confounding factor in the determination of the true relationship between Hcy, nutritional status, and cardiovascular risk factors in this group.

Effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress.

BACKGROUND: Exercise stress was shown to increase oxidative stress in rats. It lacks reports of increased protection afforded by dietary antioxidant supplements against ROS production during exercise stress. We evaluated the effects of vitamin E supplementation on renal non-enzymatic antioxidants in young rats submitted to exhaustive exercise stress. METHODS: Wistar rats were divided into three groups: 1) control group; 2) exercise stress group and; 3) exercise stress + Vitamin E group. Rats from the group 3 were treated with gavage administration of 1 mL of Vitamin E (5 mg/kg) for seven consecutive days. Animals from groups 2 and 3 were submitted to a bout of swimming exhaustive exercise stress. Kidney samples were analyzed for Thiobarbituric Acid Reactive Substances to (TBARS) by malondialdehyde (MDA), reduced glutathione (GSH) and vitamin-E levels. RESULTS: The group treated with vitamin E and submitted to exercise stress presented the lowest levels of renal MDA (1: 0.16+0.02 mmmol/mgprot vs. 2: 0.34+0.07 mmmol/mgprot vs. 3: 0.1+0.01 mmmol/mgprot; p < 0.0001), the highest levels of renal GSH (1: 23+4 µmol/gprot vs. 2: 23+2 µmol/gprot vs. 3: 58+9 µmol/gprot; p < 0.0001) and the highest levels of renal vitamin E (1: 24+6 µM/gtissue vs. 2: 28+2 µM/gtissue vs. 3: 43+4 µM/gtissue; p < 0.001). CONCLUSION: Vitamin E supplementation improved non-enzymatic antioxidant activity in young rats submitted to exhaustive exercise stress.

[Proposal for the harmonization of the values of reference for nutritional labeling in Latin America (NVR-LA)]. / Propuesta de armonización de los valores de referencia para etiquetado nutricional en latinoamérica (VRN-LA).

The values of recommendation of intake of nutrients, important for nutritional labeling, present variations among the countries of Latin America. The aim of the NVR project is to establish consensually harmonized nutritional labeling values to be adopted among the Latin American countries. From the search and analysis of the different values of recommendations used in the countries of Latin America, was defined by consensus a proposal to a total of 36 nutrient values. The expectation of everyone involved with the project is to take its accessible results and encourage the countries of the region to adopt the proposal, with the support of scientific organizations, Governments and Academia. Thus labeling will be simpler, easy understanding and help the consumer a better selection of products.

One-carbon metabolism and global DNA methylation in mothers of individuals with Down syndrome.

Down syndrome (DS) is the most common chromosomal disorder, resulting from the failure of normal chromosome 21 segregation. Studies have suggested that impairments within the one-carbon metabolic pathway can be of relevance for the global genome instability observed in mothers of individuals with DS. Based on the association between global DNA hypomethylation, genome instability, and impairments within the one-carbon metabolic pathway, the present study aimed to identify possible predictors, within the one-carbon metabolism, of global DNA methylation, measured by methylation patterns of LINE-1 and Alu repetitive sequences, in mothers of individuals with DS and mothers of individuals without the syndrome. In addition, we investigated one-carbon genetic polymorphisms and metabolites as maternal predisposing factors for the occurrence of trisomy 21 in children. Eighty-three samples of mothers of children with DS with karyotypically confirmed free trisomy 21 (case group) and 84 of mothers who had at least one child without DS or any other aneuploidy were included in the study. Pyrosequencing assays were performed to access global methylation. The results showed that group affiliation (case or control), betaine-homocysteine methyltransferase (BHMT) G742A and transcobalamin 2 (TCN2) C776G polymorphisms, and folate concentration were identified as predictors of global Alu DNA methylation values. In addition, thymidylate synthase (TYMS) 28-bp repeats 2R/3R or 3R/3R genotypes are independent maternal predisposing factors for having a child with DS. This study adds evidence that supports the association of impairments in the one-carbon metabolism, global DNA methylation, and the possibility of having a child with DS.

Genetic polymorphisms involved in folate metabolism and concentrations of methylmalonic acid and folate on plasma homocysteine and risk of coronary artery disease.

OBJECTIVES: Alterations in the enzymes involved in homocysteine (Hcy) metabolism or vitamin deficiency could play a role in coronary artery disease (CAD) development. This study investigated the influence of MTHFR and MTR gene polymorphisms, plasma folate and MMA on Hcy concentrations and CAD development. MMA and folate concentrations were also investigated according to the polymorphisms. METHODS: Two hundred and eighty-three unrelated Caucasian individuals undergoing coronary angiography (175 with CAD and 108 non-CAD) were assessed in a case-control study. Plasma Hcy and MMA were measured by liquid chromatography/tandem mass spectrometry. Plasma folate was measured by competitive immunoassay. Dietary intake was evaluated using a nutritional questionnaire. Polymorphisms MTHFR and MTR were investigated by polymerase chain reaction (PCR) followed by enzyme digestion or allele-specific PCR. RESULTS: Hcy mean concentrations were higher in CAD patients compared to controls, but below statistical significance (P = 0.246). Increased MMA mean concentrations were frequently observed in the CAD group (P = 0.048). Individuals with MMA concentrations >0.5 micromol/l (vitamin B(12) deficiency) were found only in the CAD group (P = 0.004). A positive correlation between MMA and Hcy mean concentrations was observed in both groups, CAD (P = 0.001) and non-CAD (P = 0.020). MMA mean concentrations were significantly higher in patients with hyperhomocysteinemia in both groups, CAD and non-CAD (P = 0.0063 and P = 0.013, respectively). Folate mean concentration was significantly lower in carriers of the wild-type MTHFR 1298AA genotype (P = 0.010). CONCLUSION: Our results suggest a correlation between the MTHFR A1298C polymorphism and plasma folate concentration. Vitamin B(12) deficiency, reflected by increased MMA concentration, is an important risk factor for the development both of hyperhomocysteinemia and CAD.

Fluorescence spectroscopy to diagnose hepatic steatosis in a rat model of fatty liver.

BACKGROUND: Steatosis is diagnosed on the basis of the macroscopic aspect of the liver evaluated by the surgeon at the time of organ extraction or by means of a frozen biopsy. AIM: In the present study, the applicability of laser-induced fluorescence (LIF) spectroscopy was investigated as a method for the diagnosis of different degrees of steatosis experimentally induced in rats. MATERIAL AND METHODS: Rats received a high-lipid diet for different periods of time. The animals were divided into groups according to the degree of induced steatosis diagnosis by histology. The concentration of fat in the liver was correlated with LIF by means of the steatosis fluorescence factor (SFF). RESULTS: The histology classification, according to liver fat concentration was, Severe Steatosis, Moderate Steatosis, Mild Steatosis and Control (no liver steatosis). Fluorescence intensity could be directly correlated with fat content. It was possible to estimate an average of fluorescence intensity variable by means of different confidence intervals (P=95%) for each steatosis group. SFF was significantly higher in the Severe Steatosis group (P<0.001) compared with the Moderate Steatosis, Mild Steatosis and Control groups. CONCLUSION: The various degrees of steatosis could be directly correlated with SFF. LIF spectroscopy proved to be a method capable of identifying the degree of hepatic steatosis in this animal model, and has the potential of clinical application for non-invasive evaluation of the degree of steatosis.

Effects of creatine supplementation on homocysteine levels and lipid peroxidation in rats.

Hyperhomocysteinaemia is an independent risk factor for CVD. Recent data show a relationship between homocysteine (Hcy) and free radical formation. Since creatine synthesis is responsible for most of the methyl group transfers that result in Hcy formation, creatine supplementation might inhibit Hcy production and reduce free radical formation. The present study investigated the effects of creatine supplementation on Hcy levels and lipid peroxidation biomarkers. Thirty rats were divided into three groups: control group; diet with creatine group (DCr; 2 % creatine in the diet for 28 d); creatine overload plus diet with creatine group (CrO + D; 5 g creatine/kg by oral administration for 5 d+2 % in the diet for 23 d). Plasma Hcy was significantly lower (P < 0.05) in DCr (7.5 (sd 1.2) micromol/l) and CrO + D (7.2 (sd 1.7) micromol/l) groups compared with the control group (12.4 (sd 2.2) micromol/l). Both plasma thiobarbituric acid-reactive species (TBARS) (control, 10 (sd 3.4); DCr, 4.9 (sd 0.7); CrO + D, 2.4 (sd 1) micromol/l) and plasma total glutathione (control, 4.3 (sd 1.9); DCr, 2.5 (sd 0.8); CrO + D, 1.8 (sd 0.5) micromol/l) were lower in the groups that received creatine (P < 0.05). In addition, Hcy showed significant negative correlation (P < 0.05) with plasma creatine (r - 0.61) and positive correlation with plasma TBARS (r 0.74). Plasma creatine was negatively correlated with plasma TBARS (r - 0.75) and total peroxide (r - 0.40). We conclude that creatine supplementation reduces plasma Hcy levels and lipid peroxidation biomarkers, suggesting a protective role against oxidative damage. Modulating Hcy formation may, however, influence glutathione synthesis and thereby affect the redox state of the cells.

Effects of a low-protein diet on plasma amino acid and homocysteine levels and oxidative status in rats.

BACKGROUND/AIMS: Transmethylation reactions and antioxidant metabolism are linked by transsulfuration, where homocysteine (Hcy) is converted to cysteine and reduced glutathione (GSH). Low protein intake can modulate the balance of this metabolic reaction. The aim of the present investigation was to study the effect of a low-protein diet on Hcy metabolism by monitoring levels of the amino acids involved in these pathways, and relating these levels to GSH levels and lipid peroxidation in rats. METHODS: Sixteen rats were divided into 2 groups: control (C; standard AIN-93 diet, 20% protein) and low-protein diet (LPD; 8% protein diet). Rats in both groups were placed on the diets for 28 days. RESULTS: A significant reduction (p < 0.05) in plasma Hcy concentration was found in LPD rats (0.16 +/- 0.04 micromol/mg protein) versus C rats (0.25 +/- 0.03 micromol/mg protein). Methionine levels were not significantly different between the 2 groups (C: 1.24 +/- 0.22 micromol/mg protein; LPD: 1.03 +/- 0.27 micromol/mg protein). A significant reduction (p < 0.05) in hepatic GSH concentrations (C: 44 +/- 10 micromol/mg protein; LPD: 17.4 +/- 4.3 micromol/mg protein) was accompanied by an increase in lipid peroxidation (C: 0.13 +/- 0.01 micromol/mg protein; LPD: 0.17 +/- 0.02 micromol/mg protein; r = -0.62, p < 0.01). CONCLUSION: Hcy levels were reduced under a low-protein diet, resulting in modulated methyl balance and reduced GSH formation leading to increased susceptibility of hepatic cells to oxidative events.

Vestibular evaluation using videonystagmography of chronic zinc deficient patients due to short bowel syndrome.

UNLABELLED: The presence of zinc in the auditory pathways and its probable participation in tinnitus and hearing loss are known facts, although there are no clinical trials and experimental studies showing the impact of hypozincemia in the vestibular system and zinc existence in the vestibular pathway, respectively. AIM: This study is an attempt to correlate hypozincemia and abnormal vestibular function. METHODS: This is a clinical retrospective case study where nine patients suffering of chronic zinc deficiency had their serum zinc determined and were submitted to videonystagmography. Results were compared to a normal (control) group. RESULTS: All vestibular test parameters were altered when we compared experimental and control groups. CONCLUSION: Comparison between groups shows significant differences in many aspects of the vestibular analysis and calls our attention towards a possible participation of zinc on the genesis of vestibular disorders.

Folic acid-deficient diet during gestation and post-weaning alters Pomc gene and protein expression in rat offspring.

INTRODUCTION: Background: folic acid participates in one-carbon metabolism, which supplies methyl groups to numerous reactions in the body. Impaired delivery of these methyl groups affects gene expression. We hypothesize that offspring exposed to less folic acid will express higher levels of Pomc (proopiomelanocortin) gene mRNA. Aim: to investigate the Pomc gene and protein expression pattern in the female offspring of female rats receiving a folic acid-deficient diet during gestation, lactation, and post-weaning. Methods: the study involved female rat offspring (n = 10) born from mothers subjected to a control (2.0 mg of folic acid/kg of food) or folic acid-deficient (0.5 mg of folic acid/kg of food) diet, and fed the same diet during post-weaning. Samples were collected from the arcuate nucleus of the hypothalamus of the female offspring for real-time PCR and Western blotting analyses. Results: the female offspring in the folic acid-deficient diet group had significantly higher Pomc gene and protein expression than the female offspring in the control diet group (p = 0.03, p = 0.01, respectively). Conclusion: a folic acid-deficient diet during gestation, lactation, and post-weaning increases Pomc gene and protein expression, but does not modify food intake or body weight of female rat offspring.

INTRODUCCIÓN: Antecedentes: el ácido fólico participa en el metabolismo de un solo carbono, que suministra grupos metilo a numerosas reacciones del cuerpo. La aportación alterada de estos grupos metilo afecta a la expresión génica. Nuestra hipótesis es que la descendencia expuesta a menos ácido fólico expresará niveles más altos de ARNm del gen Pomc (proopiomelanocortina). Objetivo: investigar el patrón de expresión del gen Pomc y de sus proteínas en crías de ratas hembras que recibieron una dieta deficiente en ácido fólico durante la gestación, la lactancia y el destete. Métodos: el estudio incluyó crías hembras (n = 10) nacidas de madres sometidas a una dieta control (2,0 mg de ácido fólico/kg de alimento) o deficiente en ácido fólico (0,5 mg de ácido fólico/kg de alimento) durante la gestación y la lactancia, y alimentadas con la misma dieta durante el destete. Se recolectaron muestras del núcleo arqueado del hipotálamo de las hembras para el análisis de la expresión génica (PCR en tiempo real) y de proteínas (inmunomanchado Western). Resultados: las hembras pertenecientes al grupo de dieta deficiente en ácido fólico tuvieron una expresión del gen Pomc y sus proteínas significativamente mayor que la de las hembras pertenecientes al grupo con dieta de control (p = 0,03, p = 0,01, respectivamente). Conclusión: la dieta deficiente en ácido fólico durante la gestación, la lactancia y el destete modifica la expresión del gen Pomc y sus proteínas pero no modifica la ingesta de alimentos ni el peso corporal de las ratas hembra.

Effects of acute magnesium loading on pulmonary function of stable COPD patients.

BACKGROUND: Magnesium (Mg) use has the potential to promote bronchodilatation and to improve lung function in obstructive diseases. IV administration of Mg during exacerbations of chronic obstructive pulmonary disease (COPD) has led to improved peak flow. This study aimed to investigate the effects of acute IV Mg loading on respiratory parameters of stable COPD patients. MATERIAL/METHODS: This was a randomized, double-blind, placebo-controlled crossover study. Twenty-two male COPD patients (64+/-6 years old, FEV1: 49+/-20%) received an IV infusion of 2 g of magnesium sulfate or placebo on two distinct occasions. Spirometry and mouth maximal respiratory pressures were obtained before and 45 minutes after the infusions. RESULTS: Mg use led to significant changes in functional respiratory capacity (-0.48 l, 95%CI: -0.96, -0.01), inspiratory capacity (0.21 l, 95%CI: 0.04, 0.37), maximal inspiratory pressure (10 cmH2O, 95%CI: 1.6, 18.4), and maximal expiratory capacity (10.7 cmH2O, 95%CI: 0.20, 21.2). The treatment was also associated with a marginally significant decrease in residual volume (-0.47 L, 95%CI: -0.96, 0.02, p=0.06). CONCLUSIONS: Acute IV Mg loading in stable COPD patients was associated with a reduction in lung hyperinflation and improvement of respiratory muscle strength. The clinical potential for chronic magnesium supplementation in COPD deserves further investigation.

Effects of the Consumption of Milk Biofortified with Selenium, Vitamin E, and Different Fatty Acid Profile on Immune Response in the Elderly.

SCOPE: Nutrition is a major contributing factor for immunocompetence. The aim was to assess the immune status of older people after consuming milk produced by lactating cows fed with one of the following diets: control diet (C), C + vitamin E + selenium (C + A), C + sunflower oil (C + O), and C + sunflower oil + vitamin E + selenium (A + O). METHODS AND RESULTS: Sixty elderly people received one of these biofortified milks for 12 weeks. Immune response was assessed by measurement of the expression of COX-1, COX-2, MCP-1, PPAR (δ, α, and ß/δ) genes, neutrophil production of oxygen reactive species induced by immune complexes, neutrophil phagocytosis and lytic activity of the alternative pathway of the complement system, and cytokine levels. Variables were assessed before and after treatment. Our findings showed stability of some inflammatory mediators (complement activity and neutrophils burst) in treatment groups, except complement activity in C + A, and an increase of these markers in C, especially reactive oxygen species production and phagocytic activity. TNF-α was significantly increased in all groups. In C + A, IL-4 and IL-2 increased after treatment, and in the group that received the milk produced by cows fed with "O" diet, CCL20 and IL-27 increased. CONCLUSION: Overall, as compared to C, milk biofortification was associated with stabilization of the activity of alternative complement pathway and the neutrophils burst, and modulated different cytokines levels.