Efecto de los grados día de ayuno y del hacinamiento previos al sacrificio sobre el contenido estomacal y respuesta de estrés en trucha arcoíris (Oncorhynchus mykiss)

El ayuno pre-sacrificio es una práctica rutinaria en acuicultura que se lleva a cabo para vaciar el aparato digestivo disminuyendo la cantidad de heces y previniendo una contaminación de la canal (Robb, 2008). Sin embargo, el ayuno puede también incrementar los niveles de estrés de los peces y si estos son lo suficientemente altos afectan a la calidad de la canal (Poli et al., 2005)

Efecto de la adicción de extracto de vino tinto en la conservación de hamburguesas de cordero enriquecidas en ácidos grasos omega-3

Red wine is a great source of polyphenols compounds, which exert a high antioxidant capacity. The effect of red wine extract (EV) on the oxidative stability of lamb patties in terms of metmyoglobin (MetMb) formation, lipid oxidation, protein oxidation, and the stability of docosahexaenoic fatty acid (DHA) was investigated. Ground lamb meat enriched in ω3 fatty acids was divided into four treatments. Three treatments were supplemented with 3 doses of EV being 50 (EV1), 100 (EV2) and 200 (EV3) mg GAE/kg meat and, the last one, without antioxidant supplementation, was kept as control (C). The lamb patties were stored under MAP (70% O2/30% CO2) during 9 days. There was an interaction between treatment (L) and storage period (PC) for MetMb proportion (p<0.001) and DHA content (p<0.01). Groups EV2 and EV3 showed less MetMb proportion and higher DHA content at the end of storage period in comparison to groups EV1 and C. Lipid and protein oxidation was affected by storage period (p<0.001), increasing in all treatments.El vino tinto es una gran fuente de compuestos polifenólicos que presentan una gran capacidad antioxidante. El objetivo de este estudio fue evaluar el efecto de la adición de extracto de vino (EV) en la estabilidad oxidativa de hamburguesas de cordero, estudiando la formación de metamioglobina (MetMb), la oxidación lipídica, la oxidación proteica y el contenido en ácido docosahexaenoico (DHA). Se realizaron 4 lotes de carne picada de cordero, todos enriquecidos en ácidos grasos ω3. A tres lotes se les adicionó EV para obtener una concentración final de 50 (EV1), 100 (EV2) y 200 (EV3) mg GAE/kg de carne y el último lote, sin antioxidantes, se mantuvo como control (C). Las hamburguesas se conservaron en MAP (70% O2/30% CO2) durante 9 días. Se observó una interacción entre el lote (L) y el periodo de conservación (PC) para la proporción de MetMb (p<0,001) y el contenido en DHA (p<0,01). Los lotes EV2 y EV3 presentaron menor proporción de MetMb y mayor contenido en DHA que los lotes EV1 y C. La oxidación lipídica y proteica estuvo afectada por el periodo de conservación (p<0,001) aumentando en todos los tratamientos

The developmental pathway for CD103(+)CD8+ tissue-resident memory T cells of skin

Tissue-resident memory T cells (T(RM) cells) provide superior protection against infection in extralymphoid tissues. Here we found that CD103(+)CD8(+) T(RM) cells developed in the skin from epithelium-infiltrating precursor cells that lacked expression of the effector-cell marker KLRG1. A combination of entry into the epithelium plus local signaling by interleukin 15 (IL-15) and transforming growth factor-β (TGF-β) was required for the formation of these long-lived memory cells. Notably, differentiation into T(RM) cells resulted in the progressive acquisition of a unique transcriptional profile that differed from that of circulating memory cells and other types of T cells that permanently reside in skin epithelium. We provide a comprehensive molecular framework for the local differentiation of a distinct peripheral population of memory cells that forms a first-line immunological defense system in barrier tissues.Supported by National Health and Medical Research Council of Australia and Australian Research Council

Pollution and physiological variability in gentoo penguins at two rookeries with different levels of human visitation

Human activity and specifically tourism has been increasing in Antarctica over the last few years. Few studies have examined the indirect effects of human visits on Antarctic penguin rookeries. This work aims to study the differences between a highly visited (Hannah Point) and a rarely visited (Devil's Point, Byers Peninsula) gentoo penguin rookery on Livingston Island. Our results suggest that potential indirect effects of human impact are observed in gentoo penguins at Hannah Point, a colony heavily visited by tourists. Penguins at Hannah Point showed a higher presence of heavy metals such as Pb and Ni and a higher number of erythrocytic nuclear abnormalities than penguins at Devil's Point. Immunological parameters showed different results depending on whether we consider the cellular response -the number of lymphocytes being higher in penguins from Hannah Point- or the humoral response -the level of immunoglobulins being higher in penguins from Devil's Point. Measurements of corticosterone levels in feathers and heterophil/lymphocyte (H/L) ratio in blood showed lower levels in the heavily visited rookery than in the rarely visited rookery. Finally, we did not detect Campylobacter jejuni, a bacteria potentially transmitted by humans in either of the populations and we did not find any difference in the prevalence of Campylobacter lari between the populations.Centro de Estudios Parasitológicos y de Vectore

Eating disorders: the current status of molecular genetic research

Anorexia nervosa (AN) and bulimia nervosa (BN) are complex disorders characterized by disordered eating behavior where the patient’s attitude towards weight and shape, as well as their perception of body shape, are disturbed. Formal genetic studies on twins and families suggested a substantial genetic influence for AN and BN. Candidate gene studies have initially focused on the serotonergic and other central neurotransmitter systems and on genes involved in body weight regulation. Hardly any of the positive findings achieved in these studies were unequivocally confirmed or substantiated in meta-analyses. This might be due to too small sample sizes and thus low power and/or the genes underlying eating disorders have not yet been analyzed. However, some studies that also used subphenotypes (e.g., restricting type of AN) led to more specific results; however, confirmation is as yet mostly lacking. Systematic genome-wide linkage scans based on families with at least two individuals with an eating disorder (AN or BN) revealed initial linkage regions on chromosomes 1, 3 and 4 (AN) and 10p (BN). Analyses on candidate genes in the chromosome 1 linkage region led to the (as yet unconfirmed) identification of certain variants associated with AN. Genome-wide association studies are under way and will presumably help to identify genes and pathways involved in these eating disorders. The elucidation of the molecular mechanisms underlying eating disorders might improve therapeutic approaches

The enigma of in vivo oxidative stress assessment: isoprostanes as an emerging target

Oxidative stress is believed to be one of the major factors behind several acute and chronic diseases, and may also be associated with ageing. Excess formation of free radicals in miscellaneous body environment may originate from endogenous response to cell injury, but also from exposure to a number of exogenous toxins. When the antioxidant defence system is overwhelmed, this leads to cell damage. However, the measurement of free radicals or their endproducts is tricky, since these compounds are reactive and short lived, and have diverse characteristics. Specific evidence for the involvement of free radicals in pathological situations has been difficult to obtain, partly owing to shortcomings in earlier described methods for the measurement of oxidative stress. Isoprostanes, which are prostaglandin-like bioactive compounds synthesized in vivo from oxidation of arachidonic acid, independently of cyclooxygenases, are involved in many human diseases, and their measurement therefore offers a way to assess oxidative stress. Elevated levels of F2-isoprostanes have also been seen in the normal human pregnancy, but their physiological role has not yet been defined. Large amounts of bioactive F2-isoprostanes are excreted in the urine in normal basal situations, with a wide interindividual variation. Their exact role in the regulation of normal physiological functions, however, needs to be explored further. Current understanding suggests that measurement of F2-isoprostanes in body fluids provides a reliable analytical tool to study oxidative stress-related diseases and experimental inflammatory conditions, and also in the evaluation of various dietary antioxidants, as well as drugs with radical-scavenging properties. However, assessment of isoprostanes in plasma or urine does not necessarily reflect any specific tissue damage, nor does it provide information on the oxidation of lipids other than arachidonic acid