Ultrasensitive determination of human growth hormone (hGH) with a disposable electrochemical magneto-immunosensor.

In this paper, an electrochemical magneto-immunosensor for the detection of human growth hormone (hGH) is described for the first time. The immunosensor involves the use of tosyl-activated magnetic microparticles (TsMBs) to covalently immobilize a monoclonal mAbhHG antibody. A sandwich-type immunoassay with a secondary pAbhGH antibody and anti-IgG labelled with alkaline phosphatase (anti-IgG-AP) was employed. TsMBs­mAbhGH­hGH­pAbhGH­anti-IgG-AP conjugates were deposited onto the surface of a screen-printed gold electrode using a small neodymium magnet, and electrochemical detection was performed by square-wave voltammetry upon the addition of 4-aminophenyl phosphate as the AP substrate. All the variables involved in the preparation of immunoconjugates and in the immunoassay protocol were optimized. A calibration curve for hGH was constructed with a linear range between 0.01 and 100 ng/mL (r = 0.998) and a limit of detection of 0.005 ng/mL. This value is nearly three orders of magnitude lower than that obtained using surface plasmon resonance (Treviño et al., Talanta 78:1011-1016, 2009). Furthermore, good repeatability, with RSD = 3% (n = 10) at the 1-ng/mL hGH level, was obtained. Cross-reactivity studies with other hormones demonstrated good selectivity. The magneto-immunosensor was applied to the analysis of human serum spiked with hGH at the 4- and 0.1-ng/mL levels. Mean recoveries of 96 ± 6% and 99 ± 2%, respectively, were obtained.

[Food habits and body composition of Spanish elite athletes in combat sports]. / Hábitos alimenticios y composición corporal de deportistas españoles de élite pertenecientes a disciplinas de combate.

INTRODUCTION: There is a scarcity of information about the dietary intake and food selection of combat sport people. Optimizing nutritional status, body weight, and body composition are key factors for their performance. AIM: The assessment of dietary intake, food habits, and body composition in elite combat sport people. SUBJECTS AND METHODS: 22 sportsmen were recruited from the Spanish National Teams of Tae kwon do, Judo, and Boxing. Food intake (FFQ), food habits and body composition (DXA and Bioimpedance) were analyzed. RESULTS AND DISCUSSION: Weight and body composition of the individuals assessed were similar to that previously described, although almost half of them were moderately over their desired competition weight. A lower than the recommended intake of vegetables (77% of individuals), cereals, bread, rice, potatoes, and pasta (73%), while red meat and derivatives intake exceeded the recommendations. Their main preferences were pasta, meat, and cereals. Legumes, vegetables, and fish were their main dislikes. A statistically significant relationship between food preferences and intakes was only observed for legumes, yogurt, and nuts. The athletes reported that reducing the intake of biscuits and confectionery (68% of individuals), high-fat foods (36%), and/or bread (27%) would be a good dietetic strategy for losing weight. None of them reported that voluntary dehydration would be a good strategy for this purpose. CONCLUSIONS: food offer to which this sport people have access and their choices are adequate, although the intake of some food groups (vegetables, red meat and derivatives) does not follow the recommendations. Their body weight slightly exceeds their competition weight, what it is frequently found in these sports. Nevertheless, their knowledge about nutrition and dietetics applied to exercise are acceptable.

Hábitos alimenticios y composición corporal de deportistas españoles de élite pertenecientes a disciplinas de combate / Food habits and body composition of Spanish elite athletes in combat sports

Introducción: La información disponible acerca de las prácticas dietéticas habituales y los factores que influyen en la selección de alimentos en deportistas de combate es escasa a pesar de su importancia para optimizar el estado nutricional. Objetivo: Evaluar la ingesta dietética, los hábitos alimenticios y la composición corporal de deportistas de combate de élite. Sujetos y métodos: Se analizaron el consumo de alimentos (CFCA), los hábitos alimenticios y la composición corporal (DXA y Bioimpedancia) de 22 deportistas varones pertenecientes a las Selecciones Nacionales Españolas de taekwondo, judo y boxeo. Resultados y discusión: El peso y la composición corporal fueron similares a los descritos previamente, aunque casi la mitad de los deportistas estaba moderadamente por encima de su peso de competición. Se observó un consumo bajo de verduras y hortalizas (77% de los individuos) y cereales, pan, arroz, patatas y pasta (73%) y elevado de carnes grasas, embutidos. Las principales preferencias fueron pasta, carne y cereales; las aversiones, legumbres, verduras y pescado. Las preferencias sólo se relacionaron estadísticamente con la ingesta de legumbres, yogur y frutos secos. Con respecto a las modificaciones dietéticas que consideraban más adecuadas para perder peso, el 68% indicó que habría que disminuir o eliminar los dulces y la bollería, el 36% los alimentos grasos y el 27% el pan. Ninguno declaróque utilizaría la deshidratación voluntaria con este fin. Conclusiones: la oferta alimentaria a la que tienen acceso estos deportistas y su selección dietética son adecuadas, aunque el consumo de algunos grupos de alimentos (verduras y hortalizas; carnes grasas, embutidos) no se ajusta a las recomendaciones. Presentan un peso ligeramente superior al de su categoría de competición, lo que es característico de este tipo de deportes. No obstante, muestran unos conocimientos aceptables sobre nutrición y dietética aplicada a su deporte (AU)

Introduction: There is a scarcity of information about the dietary intake and food selection of combat sport people. Optimizing nutritional status, body weight, and body composition are key factors for their performance. Aim: The assessment of dietary intake, food habits, and body composition in elite combat sport people. Subjects and methods: 22 sportmen were recruited from the Spanish National Teams of Taekwondo, Judo, and Boxing. Food intake (FFQ), food habits and bodycomposition (DXA and Bioimpedance) were analyzed. Results and discussion: Weight and body composition of the individuals assessed were similar to that previously described, although almost half of them were moderately over their desired competition weight. A lower than the recommended intake of vegetables (77% of individuals), cereals, bread, rice, potatoes, and pasta (73%), while red meat and derivatives intake exceeded the recommendations. Their main preferences were pasta, meat, and cereals. Legumes, vegetables, and fish were their main dislikes. A statistically significant relationship between food preferences and intakes was only observed for legumes, yogurt, and nuts. The athletes reported that reducing the intake of biscuits and confectionery (68% of individuals), high-fat foods (36%), and/or bread (27%) would be a good dietetic strategy for losing weight. None of them reported that voluntary dehydration would be a good strategy for this purpose. Conclusions: food offer to which this sport people have access and their choices are adequate, although the intake of some food groups (vegetables, red meat and derivatives) does not follow the recommendations. Their body weight slightly exceeds their competition weight, what it is frequently found in these sports. Nevertheless, their knowledge about nutrition and dietetics applied to exercise are acceptable (AU)

Moderate or supranormal folic acid supplementation does not exert a protective effect for homocysteinemia and methylation markers in growing rats.

BACKGROUND/AIMS: Folic acid (FA) deficiency/supplementation effects seem to be dependent on age group and/or physiological status. The aim was to evaluate changes associated with rapid growth in relation to methionine metabolism in rats. METHODS: Four groups (n = 10 each) of male Sprague Dawley rats (5 weeks old) were on diets that varied in their FA content: 0 mg FA/kg diet (deficient), 2 mg FA/kg diet (control), 8 mg FA/kg diet (moderate supplementation), 40 mg FA/kg diet (supranormal supplementation). Animals were fed ad libitum for 30 days. Biomarkers of methionine metabolism and antioxidant status were evaluated. RESULTS: Serum total homocysteine concentration increased (p < 0.01) in FA deficient animals, with no differences between the supplemented groups. The hepatic 'methylation ratio' (S-adenosylmethionine/S-adenosylhomocysteine) of the FA content groups reached similar values, which were significantly higher compared to the deficient group. The brain 'methylation ratio', however, remained unmodified independently of FA content in the diet. FA deficiency induced hepatic DNA hypomethylation, and supranormal FA supplementation exerted the most protective effect (p < 0.01). Serum folate levels increased according to FA dietary level, whereas no differences were seen for vitamin B(12) and vitamin B(6). CONCLUSIONS: FA deficiency compromises methionine metabolism whereas supplementation does not show an additional positive effect compared to the control diet in growing animals.

[Dietary food habits, nutritional status and lifestyle in menopausal women in Spain]. / Hábitos alimentarios, estado nutricional y estilos de vida en una población de mujeres menopaúsicas españolas.

AIM: To analyse the diet and the dietary food habits in a sample of 1,218 Spanish women, aged 40 to 77 years, in the menopausal or perimenopausal condition. Women were recruited nationwide and the diet was assessed using a food frequency questionnaire. RESULTS: Diet in our population group was close to the representative dietary habits of the Spanish population, except for dairy products. These were highly consumed (approximately 4 servings/day) by menopausal women. Energy, protein and cholesterol intakes, as well as most vitamins and mineral intakes, were very high, as compared to recommended dietary allowances. We only found marginal deficient intakes for folate and vitamin D. Women over 60 years consume less eggs, sweats, sugar and miscellany, and therefore less lipids and cholesterol, as well as vitamin D, than younger women. A high rate (61%) of overweight and obesity (BMI > 25) was present in our population group and was associated with a higher intake of meat, fish and eggs, as well as energy. A healthier diet (high intake of dairy products, fresh vegetables, fruits, legumes, cereals and fish) was associated with a healthier lifestyle (no smoking, physical exercise) and the use of fortified foods and vitamin/mineral supplements. A high percentage of women regularly consumed fortified food (52,7%) and micronutrient supplements (22,8%) although diets provided enough vitamins and minerals. CONCLUSION: Diet in our study group is in accordance to healthy dietary habits and physical activity recommendations. This is probably due to a greater concern for health in women close to the menopause condition.

Hábitos alimentarios, estado nutricional y estilos de vida en una población de mujeres menopáusicas españolas / Dietary food habits, nutritional status and lifestyle in menopausal women in Spain

Objetivo: Conocer la dieta y los hábitos alimentarios, a partir de un cuestionario de frecuencia de consumo de alimentos, de una muestra de 1.218 mujeres españolas en estado de menopausia-perimenopausia y edades comprendidas entre 40 y 77 años, procedentes de todas las Comunidades Autónomas. Resultados: La dieta de la muestra de estudio es equivalente a la dieta media de la población española, destacando los productos lácteos, que son consumidos en mayor cantidad por las mujeres participantes (aproximadamente 4 raciones/ día). La ingesta energética, de proteínas y de colesterol es elevada, así como de la mayoría de vitaminas y minerales. Únicamente se han encontrado ingestas deficitarias moderadas para el ácido fólico y la vitamina D. Las mujeres de mayor edad (> 60 años) consumen menos alimentos del grupo de huevos, dulces y azúcar y varios y, por tanto, de lípidos y colesterol, aunque también de vitamina D. Un IMC elevado (IMC > 25; 61% de la población) está asociado con un mayor consumo de carnes, pescados y huevos y, por tanto, de energía. Una dieta más adecuada (mayor consumo de lácteos, frutas, verduras, legumbres, cereales y pescados) está asociada a un estilo de vida más saludable (no fumar, practicar ejercicio físico) y a la ingesta de alimentos fortificados (52,7% de la muestra total) y suplementos vitamínicos y minerales (22,8% de la muestra total), aun cuando el aporte de los micronutrientes es suficiente a través de la dieta habitual. Conclusiones: En conjunto, la dieta de nuestra población de estudio se adecúa a los patrones de dieta saludable y actividad física, reflejo de la preocupación por la salud de la mujer en la etapa de la menopausia

Aim: To analyse the diet and the dietary food habits in a sample of 1,218 Spanish women, aged 40 to 77 years, in the menopausal or perimenopausal condition. Women were recruited nationwide and the diet was assessed using a food frequency questionnaire. Results: Diet in our population group was close to the representative dietary habits of the Spanish population, except for dairy products. These were highly consumed (approximately 4 servings/day) by menopausal women. Energy, protein and cholesterol intakes, as well as most vitamins and mineral intakes, were very high, as compared to recommended dietary allowances. We only found marginal deficient intakes for folate and vitamin D. Women over 60 years consume less eggs, sweats, sugar and miscellany, and therefore less lipids and cholesterol, as well as vitamin D, than younger women. A high rate (61%) of overweight and obesity (BMI > 25) was present in our population group and was associated with a higher intake of meat, fish and eggs, as well as energy. A healthier diet (high intake of dairy products, fresh vegetables, fruits, legumes, cereals and fish) was associated with a healthier lifestyle (no smoking, physical exercise) and the use of fortified foods and vitamin/mineral supplements. A high percentage of women regularly consumed fortified food (52,7%) and micronutrient supplements (22,8%) although diets provided enough vitamins and minerals. Conclusion: Diet in our study group is in accordance to healthy dietary habits and physical activity recommendations. This is probably due to a greater concern for health in women close to the menopause condition

Supranormal dietary folic acid supplementation: effects on methionine metabolism in weanling rats.

There are nationwide folic acid (FA) fortification programmes of staple foods established or under consideration in order to prevent neural tube defects. Universal FA fortification still remains controversial because of the concern that additional FA in the diets of population groups (e.g. children and elderly) not initially targeted for fortification may suffer adverse effects. However, dietary surveys regarding folate generally deal with adults and little is known about the consumption and long-term effects of fortified food and supplements in growing individuals. Recent reports from our laboratory show several effects of high-dose folate supplementation in rats. In the present work, we studied the effect of FA on the methionine cycle in weanling (3-week-old) male rats after 4 weeks of supplementation with 40 mg FA/kg diet v. control (1 mg FA/kg diet). FA supplementation resulted in a reduction of homocysteine and creatinine concentrations v. control group. FA supplementation did not alter S-adenosylmethionine/S-adenosylhomocysteine ratio, DNA methylation, enzymatic activities or concentrations of vitamins involved in the nutritional regulation of the methionine cycle, except for folate. FA supplementation of 40 mg/kg did not lead to hepatic or renal damage. In conclusion, there were no apparent adverse effects on one-carbon metabolism after FA supplementation in the studied conditions.

High-dose folic acid supplementation in rats: effects on gestation and the methionine cycle.

There is new evidence that a good folate status may play a critical role in the prevention of neural-tube defects and in lowering elevated homocysteine concentrations. This adequate folate status may be achieved through folic acid dietary supplementation. Folate is a water-soluble vitamin with a low potential toxicity. However, the possible consequences of long-term high-dose folic acid supplementation are unknown, especially those related to the methionine cycle, where folate participates as a substrate. With the aim of evaluating such possible effects, four groups of Wistar rats were classified on the basis of physiological status (virgin v. pregnant) and the experimental diet administered (folic-acid-supplemented, 40 mg/kg diet v. control, 2 mg folic acid/kg diet). Animals were fed on the diets for 3 weeks. Results showed that gestation outcome was adequate in both groups regardless of the dietary supplementation. However, there were reductions (P < 0.001) in body weight and vertex-coccyx length in fetuses from supplemented dams v. control animals. Folic acid administration also induced a higher (P < 0.01) S-adenosylmethionine: S-adenosylhomocysteine value due to increased S-adenosylmethionine synthesis (P < 0.01). However, hepatic DNA methylation and serum methionine concentrations remained unchanged. Serum homocysteine levels were reduced in supplemented dams (P < 0.05). Finally, pregnancy caused lower serum folate, vitamin B6 and vitamin B12 levels (P < 0.05). Folic acid administration prevented the effect of pregnancy and raised folate levels in dams, but did not change levels of vitamins B12 and B6. These new findings are discussed on the basis of potential benefits and risks of dietary folic acid supplementation.

High dietary folate supplementation affects gestational development and dietary protein utilization in rats.

There is new evidence that good folate status may play a critical role in the prevention of neural tube defects and in the maintenance of adequate homocysteine levels, an amino acid recently identified as a risk factor for cardiovascular disease. This has led to different folate recommendations, all of them much higher than the present dietary recommendations. Folic acid is a water-soluble vitamin with a low potential toxicity. However, the possible consequences of long-term, high folate intakes are unknown. Therefore, the present study was undertaken to determine the effects of long-term, high dietary folate supplementation on gestational and nutritional markers in pregnant and virgin rats. Four groups of Wistar rats were classified on the basis of physiological status (virgin or pregnant) and the experimental diets administered (folic acid supplemented, 40 mg/kg diet; or control diet, 2 mg folic acid/kg diet). Rats were fed their respective diets for 3 wk. Two critical periods were used for metabolic balance studies (experimental d 1-5 and 17-21), which involved the determination of fat and protein digestibilities as well as metabolic protein utilization (MPU) and net protein utilization (NPU). Gestational development (number of live fetuses) was adequate in both diet groups regardless of folate supplementation. However, body weight and vertex-coccyx length in fetuses from supplemented dams were less than (P < 0.0001) in fetuses of control dams. Fat and nitrogen digestibilities were not affected by supplementation, but MPU and NPU coefficients were significantly lower (P < 0.05) in the folic acid-supplemented groups, irrespective of physiological status, compared to control rats. These new findings of macro-micronutrient interactions caused by high folate supplementation are discussed on the basis that the vitamin may act as a xenobiotic more than as a nutrient.

Impaired methionine synthesis and hypomethylation in rats exposed to valproate during gestation.

BACKGROUND: The antiepileptic drug valproic acid (VPA) may be teratogenic. The mechanism of teratogenicity remains unclear, but it has been hypothesized that VPA interferes with folate metabolism. OBJECTIVE: To study the effect of VPA on the methionine cycle and transmethylation reactions in pregnant rats. METHODS: Wistar rats were treated with VPA (300 mg/kg/day) on gestation days 8, 9, and 10, alone or in combination with folinic acid (FOL, 4 mg/kg/day) on gestation days 8, 9, and 10 or S-adenosylmethionine (SAM, 10 mg/kg/day) throughout gestation days 1 to 10. RESULTS: VPA induced a reduction in maternal methionine serum concentration (p < 0.05) caused by a 24% reduction of methionine synthase activity in liver. This provoked hepatic DNA hypomethylation, although the methylation ratio (S-adenosylmethionine/S-adenosylhomocysteine) was not altered. Homocysteine, folate, and vitamin B12 serum concentrations, as well as methionine adenosyltransferase and betaine homocysteine methyltransferase hepatic activities, did not change. In fetuses exposed to VPA, no effect was observed in hepatic methionine content, but the methylation ratio was reduced (p < 0.01), leading again to hepatic DNA hypomethylation. Coadministration of FOL prevented VPA-induced alterations in methionine synthesis and corrected fetal DNA hypomethylation. By contrast, SAM did not exert a protective effect on fetal DNA methylation. CONCLUSION: Impaired methionine synthesis and DNA hypomethylation may be involved in VPA-induced teratogenesis.