Componentes biológicamente activos de la leche materna

La leche materna es un complejo fluido biológico que aporta la energía y los nutrientes esenciales para el desarrolloy crecimiento del recién nacido. Pero además, la leche materna contiene toda una serie de compuestos bioactivoscomo enzimas, hormonas, factores de crecimiento, proteínas específicas, poliaminas, nucleótidos, oligosacáridos, etc.,que ejercen efectos biológicos y que en conjunto reciben el nombre de “factores tróficos de la leche”. Estos compuestosbiactivos son considerados nutrientes potencialmente esenciales en periodos de desarrollo y en determinadasenfermedades, cuando la capacidad de síntesis no supera las necesidades de los mismos. Aunque las fórmulasinfantiles aportan todos los nutrientes para un adecuado desarrollo del recién nacido, carecen de muchos de estoscompuestos. Este artículo pretende realizar una revisión acerca de los conocimientos actuales sobre los efectosbiológicos de la lactoferrina, nucleótidos, poliaminas y oligosacáridos

Daily consumption of a dairy drink enriched with DHA, Vitamins and minerals enhanced nutritional status and cognitive abilities parameters

Preadolescence is a period of growth with special nutritional requirements. In this research we investigated the effects produced by a 5-month consumption of an enriched dairy drink on biochemical and cognitive development parameters in children. Methods: 119 children (8 14y) of both genders (male 49%, female 51%) were randomly distributed into two study groups. The supplemented group (SG, n = 60) consumed 0.6 L/day (breakfast, elevenses and teatime) of an enriched dairy drink containing fish oils (high in DHA), oleic acid, carbohydrates (sugar and honey), vitamins (A, B complex, C, D, and E) and minerals (calcium, phosphorus, zinc) (Puleva Max®). The control group (CG, n = 59) consumed 0.6 L/day of standard whole milk. Both groups received the same dietary advice and consumed the dairy drinks for 5-moths, in addition to their usual diet. Blood samples and psychometric tests (some subscales of W.I.S.C.-IV of Wechsler and EVALUA of Vidal) were taken at 0 and 5 months. RM ANOVA was applied. Data are expressed as mean±SEM. Results: The consumption of the enriched dairy drink (SG) produced significant (p < 0.05) increases in plasma DHA (20%) and calcium (1.5%). Total proteins (1.9%), transferrine (2.1%), total cholesterol (3.3%) and HDLcholesterol (5.2%), but not LDL-cholesterol, decreased significantly in CG. Regarding psychometric parameters, digits span (working memory test), speed reading and reading comprehension scores showed significant increases in SG at the end of the study (16.8%, 19.1%, and 19.0% respectively) whereas CG only showed higher scores in the reading comprehension test (19.2%). Conclusion: The dietary supplementation with the enriched dairy drink improved the nutritional and biochemical status and a number of cognitive performance markers in children of 8 and 14 years. Supported by Puleva Food SA.Universidad e Granada Puleva Biotech S

Contribution of microscopy for understanding the mechanism of action against trypanosomatids

Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Visualization of Glutamine Transporter Activities in Living Cells Using Genetically Encoded Glutamine Sensors

Glutamine plays a central role in the metabolism of critical biological molecules such as amino acids, proteins, neurotransmitters, and glutathione. Since glutamine metabolism is regulated through multiple enzymes and transporters, the cellular glutamine concentration is expected to be temporally dynamic. Moreover, differentiation in glutamine metabolism between cell types in the same tissue (e.g. neuronal and glial cells) is often crucial for the proper function of the tissue as a whole, yet assessing cell-type specific activities of transporters and enzymes in such heterogenic tissue by physical fractionation is extremely challenging. Therefore, a method of reporting glutamine dynamics at the cellular level is highly desirable. Genetically encoded sensors can be targeted to a specific cell type, hence addressing this knowledge gap. Here we report the development of Föster Resonance Energy Transfer (FRET) glutamine sensors based on improved cyan and yellow fluorescent proteins, monomeric Teal Fluorescent Protein (mTFP)1 and venus. These sensors were found to be specific to glutamine, and stable to pH-changes within a physiological range. Using cos7 cells expressing the human glutamine transporter ASCT2 as a model, we demonstrate that the properties of the glutamine transporter can easily be analyzed with these sensors. The range of glutamine concentration change in a given cell can also be estimated using sensors with different affinities. Moreover, the mTFP1-venus FRET pair can be duplexed with another FRET pair, mAmetrine and tdTomato, opening up the possibility for real-time imaging of another molecule. These novel glutamine sensors will be useful tools to analyze specificities of glutamine metabolism at the single-cell level

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

INFLUENCE OF INGESTING CASEIN PROTEIN AND WHEY PROTEIN CARBOHYDRATE BEVERAGES ON RECOVERY AND PERFORMANCE OF AN ENDURANCE CYCLING TEST

The main aim of this study was to determine if short-term post exercise recovery, cycling performance and blood analysis were altered when consuming three different beverages with the same amounts of calories, a carbohydrate-only beverage (CHO, 9% carbohydrate) a carbohydrate and casein protein beverage (CHO+Pc, 7% carbohydrate and 2% protein) and a carbohydrate and whey hydrolyzed drink (CHO+Pw, 7% + 2 %). Fifteen male cyclists (VO2peak= 63.4±9.6 ml•kg-1•min-1) performed three trials using a randomly counterbalanced, double-blind design. In each trial one litre of one of the test drinks was consumed in fasting conditions after 1 hour ride at 75% VO2peak. After a two hours recovery period the cyclists rode 20 km at the rider’s maximum speed for this distance. The results showed no significant differences in the 20-km ride when consuming the CHO (1770±210 s), the CHO+Pc drink (1819±185 s) or the CHO+Pw (1803±201). Post-exercise creatine kinase (CK) was not significantly different between treatments. However, serum insulin concentrations were higher during recovery when CHO+Pc and CHO+Pw beverages were consumed (P<0.05). Glucagon and lactic acid levels increased more on the CHO than on the CHO+Pc and CHO+Pw treatments (P<0.05) at the end of the 20 km test. Within the context of this experimental design, the CHO+Pc and CHO+Pw beverages showed different physiological effects than the CHO drink. One purported mechanism indicates muscle glycogen re-synthesis is enhanced when protein is added to a CHO recovery formula. The CHO+Pw and CHO+Pc drinks could be recommended for improving recuperation from intensive exercise. Although this was not reflected in post-recovery exercise performance in this 20 km test, a harder or longer test may be more affected by the physiological parameters especially in the last kilometres of the test

EFFECTS OF A CARBOHYDRATE AND A CARBOHYDRATE AND CASEIN PROTEIN BEVERAGES ON RECOVERY AND PERFORMANCE OF ENDURANCE CYCLING CAPACITY

The main aim of this study was to determine if short-term post exercise recovery, cycling performance and muscle damage were altered when consuming a carbohydrate-only beverage (CHO, 7% carbohydrate) versus a carbohydrate and casein protein beverage (CHO+P, 7% carbohydrate and 4% protein). Fifteen male cyclists (VO2peak= 63.4±9.6 ml•kg-1•min-1) performed two trials using a randomly counterbalanced, double-blind design. In each trial one liter of one of the test drinks was consumed in fasting conditions after 1 hour ride at 75% VO2peak determined by Arts and Kuipers´ regression equation .After a two hours recovery period the cyclists rode 20 km at the rider’s maximum speed for this distance. The results showed no significant differences in the 20-km ride when consuming the CHO (1770±210 s) or the CHO+P drink (1819±185 s). Post-exercise creatine kinase (CK) was not significantly different between treatments. However, serum insulin concentrations were higher during recovery when CHO+P beverage was consumed (P<0.05). Glucagon and lactic acid levels increased more on the CHO than on the CHO+P treatment (P<0.05) at the end of the 20 km test. Within the context of this experimental design, the CHO+P drink showed different physiological effects than the CHO drink, so that the CHO+P drink can be recommended for improving recuperation from intensive exercise. Although this was not reflected in post-recovery exercise performance in this 20 km test, a harder or longer test may be more affected by the physiological parameters