BackgroundStrenuous physical activity can alter the status of folic acid, a vitamin directly associated with homocysteine (Hcy); alterations in this nutrient are a risk factor for cardiovascular disease. Handball players are a population at risk for nutrient deficiency because of poor dietary habits.ObjectiveThe aims of this study were to evaluate nutritional status for macronutrients and folic acid in members of a high-performance handball team, and determine the effect of a nutritional intervention with folic acid supplementation and education.DesignA total of 14 high-performance handball players were monitored by recording training time, training intensity (according to three levels of residual heart rate (RHR): <60%, 60%–80% and >80%), and subjective perceived exertion (RPE) during a 4-month training period. Nutritional, laboratory and physical activity variables were recorded at baseline (Week 0), after 2 months of dietary supplementation with 200 μg folic acid (50% of the recommended daily allowance) (Week 8) and after 2 months without supplementation (Week 16). We compared training load and analyzed changes in plasma concentrations of Hcy before and after the intervention.ResultsBivariate analysis showed a significant negative correlation (P < 0.01) between Hcy and folic acid concentrations (r = −0.84) at Week 8, reflecting a significant change in Hcy concentration (P < 0.05) as a result of hyperhomocysteinemia following the accumulation of high training loads. At Week 16 we observed a significant negative correlation (P < 0.01) between Hcy concentration and training time with an RHR <60%, indicating that aerobic exercise avoided abrupt changes in Hcy and may thus reduce the risk of cardiovascular accidents in high-performance athletes.ConclusionIntegral monitoring and education are needed for practitioners of handball sports to record their folic acid status, a factor that directly affects Hcy metabolism. Folic acid supplementation may protect athletes against alterations that can lead to cardiovascular events related to exertion during competition.

The behavior against temperature and thermal stability of enzymes is a topic of importance for industrial biocatalysis. This study focuses on the kinetics and thermodynamics of the thermal inactivation of Lipase PS from B. cepacia and Palatase from R. miehei. Thermal inactivation was investigated using eight inactivation models at a temperature range of 40–70 °C. Kinetic modeling showed that the first-order model and Weibull distribution were the best equations to describe the residual activity of Lipase PS and Palatase, respectively. The results obtained from the kinetic parameters, decimal reduction time (D and tR), and temperature required (z and z’) indicated a higher thermal stability of Lipase PS compared to Palatase. The activation energy values (Ea) also indicated that higher energy was required to denature bacterial (34.8 kJ mol−1) than fungal (23.3 kJ mol−1) lipase. The thermodynamic inactivation parameters, Gibbs free energy (DG#), entropy (DS#), and enthalpy (DH#) were also determined. The results showed a DG# for Palatase (86.0–92.1 kJ mol−1) lower than for Lipase PS (98.6–104.9 kJ mol−1), and a negative entropic and positive enthalpic contribution for both lipases. A comparative molecular dynamics simulation and structural analysis at 40 °C and 70 °C were also performed.

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RESUMEN: 24 ratas hembras de 4 meses de vida con peso aproximado de 250 gramos fueron divididas en dos grupos de animales, A y B. Ambos grupos se mantuvieron con pellet y solución de alcohol 40% durante 60 días generándoseles una hepatoesteatosis microvesicular. Los hígados de los animales pertenecientes al grupo B fueron estimulados con láser infrarrojo 6 J/cm 2 durante 15 días consecutivos. Posteriormente, las ratas fueron sacrificadas y se extrajeron muestras de hígado y luego procesadas para microscopía electrónica de transmisión. De ambos tipos celulares se obtuvieron microfotografías electrónicas de transmisión con aumentos finales de 8.500 X, las cuales fueron sometidas a estudios morfométricos para determinar fracciones volumétricas de los siguientes componentes celulares: Retículo endoplasmático rugoso (RER), mitocondrias, inclusiones lipídicas y de glicógeno, eu y heterocromatina. De igual manera se cuantificaron las áreas celulares y nucleares. Del análisis de los resultados entre hepatocitos esteatósicos e irradiados se visualiza que existen diferencias en todos los componentes celulares cuantificados y se concluye que los efectos de la estimulación infrarroja con dosis de 6 J/cm 2 provoca en los hepatocitos con esteatosis microvesicular transformación en su ultraestructura y en su morfología, fundamentalmente en la disminución acentuada de las infiltraciones lipídicas hasta en un 80% situación que se traduciría, en una variación funcional, representando de esta manera un efecto evidente que estas inducciones infrarrojas generan.