RESUMO
The human ageing process is universal, ubiquitous and inevitable. Every physiological function is being continuously diminished. There is a range between two distinct phenotypes of ageing, shaped by patterns of living - experiences and behaviours, and in particular by the presence or absence of physical activity (PA) and structured exercise (i.e., a sedentary lifestyle). Ageing and a sedentary lifestyle are associated with declines in muscle function and cardiorespiratory fitness, resulting in an impaired capacity to perform daily activities and maintain independent functioning. However, in the presence of adequate exercise/PA these changes in muscular and aerobic capacity with age are substantially attenuated. Additionally, both structured exercise and overall PA play important roles as preventive strategies for many chronic diseases, including cardiovascular disease, stroke, diabetes, osteoporosis, and obesity; improvement of mobility, mental health, and quality of life; and reduction in mortality, among other benefits. Notably, exercise intervention programmes improve the hallmarks of frailty (low body mass, strength, mobility, PA level, energy) and cognition, thus optimising functional capacity during ageing. In these pathological conditions exercise is used as a therapeutic agent and follows the precepts of identifying the cause of a disease and then using an agent in an evidence-based dose to eliminate or moderate the disease. Prescription of PA/structured exercise should therefore be based on the intended outcome (e.g., primary prevention, improvement in fitness or functional status or disease treatment), and individualised, adjusted and controlled like any other medical treatment. In addition, in line with other therapeutic agents, exercise shows a dose-response effect and can be individualised using different modalities, volumes and/or intensities as appropriate to the health state or medical condition. Importantly, exercise therapy is often directed at several physiological systems simultaneously, rather than targeted to a single outcome as is generally the case with pharmacological approaches to disease management. There are diseases for which exercise is an alternative to pharmacological treatment (such as depression), thus contributing to the goal of deprescribing of potentially inappropriate medications (PIMS). There are other conditions where no effective drug therapy is currently available (such as sarcopenia or dementia), where it may serve a primary role in prevention and treatment. Therefore, this consensus statement provides an evidence-based rationale for using exercise and PA for health promotion and disease prevention and treatment in older adults. Exercise prescription is discussed in terms of the specific modalities and doses that have been studied in randomised controlled trials for their effectiveness in attenuating physiological changes of ageing, disease prevention, and/or improvement of older adults with chronic disease and disability. Recommendations are proposed to bridge gaps in the current literature and to optimise the use of exercise/PA both as a preventative medicine and as a therapeutic agent.
Assuntos
Envelhecimento/fisiologia , Exercício Físico , Fragilidade , Promoção da Saúde , Qualidade de Vida , Idoso , Exercício Físico/fisiologia , Terapia por Exercício/normas , Fragilidade/prevenção & controle , Humanos , Fenótipo , Comportamento SedentárioRESUMO
Uranium may pose a hazard to ecosystems and human health due to its chemotoxic and radiotoxic properties. The long half-life of many U isotopes and their ability to migrate raise concerns over disposal of radioactive wastes. This work examines the long-term U bioavailability in aerobic soils following direct deposition or transport to the surface and addresses two questions: (i) to what extent do soil properties control the kinetics of U speciation changes in soils and (ii) over what experimental timescales must U reaction kinetics be measured to reliably predict long-term of impact in the terrestrial environment? Soil microcosms spiked with soluble uranyl were incubated for 1.7 years. Changes in UVI fractionation were periodically monitored by soil extractions and isotopic dilution techniques, shedding light on the binding strength of uranyl onto the solid phase. Uranyl sorption was rapid and strongly buffered by soil Fe oxides, but UVI remained reversibly held and geochemically reactive. The pool of uranyl species able to replenish the soil solution through several equilibrium reactions is substantially larger than might be anticipated from typical chemical extractions and remarkably similar across different soils despite contrasting soil properties. Modelled kinetic parameters indicate that labile UVI declines very slowly, suggesting that the processes and transformations transferring uranyl to an intractable sink progress at a slow rate regardless of soil characteristics. This is of relevance in the context of radioecological assessments, given that soil solution is the key reservoir for plant uptake.
Assuntos
Monitoramento Ambiental/métodos , Poluentes Radioativos do Solo/análise , Solo/química , Urânio/análise , Adsorção , Disponibilidade Biológica , Ecossistema , Cinética , Poluentes Radioativos do Solo/química , Solubilidade , Reino Unido , Urânio/químicaRESUMO
The use of terrestrial raw materials to replace fish meal (FM) and fish oil (FO) in marine fish diets may affect fish growth performance and health. In the last years functional additives have been profiled as good candidates to reduce the effects on health and disease resistance derived from this replacement, via reinforcement of the fish immune system. In the present study, three isoenergetic and isonitrogenous diets with low FM and FO (10% and 6% respectively) were tested based on supplementation either with 0.5% galactomannanoligosaccharides (GMOS diet) or 0.02% of a mixture of essential oils (PHYTO diet), a non-supplemented diet was defined as a control diet. Fish were fed the experimental diets in triplicate for 9 weeks and then they were subjected to a stress by confinement as a single challenge (C treatment) or combined with an experimental intestinal infection with Vibrio anguillarum (CI treatment). Along the challenge test, selected stress and immunological parameters were evaluated at 2, 24 and 168h after C or CI challenges. As stress indicators, circulating plasma cortisol and glucose concentrations were analyzed as well as the relative gene expression of cyp11b hydroxylase, hypoxia inducible factor, steroidogenic acute regulatory protein, heat shock protein 70 and heat shock protein 90 (cyp11b, hif-1α, StAR, hsp70 and hsp90). As immune markers, serum and skin mucus lysozyme, bactericidal and peroxidase activities were measured, as well as gene expression of Caspase-3 (casp-3) and interleukin 1ß (il-1ß). The use of functional additives induced a significant (p < 0.05) reduction of circulating plasma cortisol concentration when confinement was the unique challenge test applied. Supplementation of PHYTO induced a down-regulation of cyp11b, hif-1α, casp-3 and il-1ß gene expression 2h after stress test, whereas StAR expression was significantly (p < 0.05) up-regulated. However, when combination of confinement stress and infection was applied (CI treatment), the use of PHYTO significantly (p < 0.05) down-regulated StAR and casp-3 gene expression 2h after challenge test, denoting that PHYTO diet reinforced fish capacity of stress response via protection of head kidney leucocytes from stress-related apoptotic processes, with lower caspase-3 gene expression and a higher il-1ß gene expression when an infection occurs. Additionally, dietary supplementation with GMOS and PHYTO compounds increased fish serum lysozyme after infection. Both functional additives entailed a better capability of the animals to cope with infection in European sea bass when fed low FM and FO diets.
Assuntos
Ração Animal/análise , Bass/imunologia , Suplementos Nutricionais/análise , Óleos de Peixe/administração & dosagem , Prebióticos/administração & dosagem , Estresse Fisiológico , Animais , Aquicultura , Bass/genética , Caspase 3/genética , Caspase 3/imunologia , Resistência à Doença , Hidrocortisona/sangue , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Óleos Voláteis/administração & dosagem , Oligossacarídeos/administração & dosagemRESUMO
To understand the dynamic mechanisms governing soil-to-plant transfer of selenium (Se), technetium-99 (99Tc) and iodine (I), a pot experiment was undertaken using 30 contrasting soils after spiking with 77Se, 99Tc and 129I, and incubating for 2.5 years. Two grass species (Agrostis capillaris and Lolium perenne) were grown under controlled conditions for 4 months with 3 cuts at approximately monthly intervals. Native (soil-derived) 78Se and127I, as well as spiked 77Se, 99Tc and 129I, were assayed in soil and plants by ICP-MS. The grasses exhibited similar behaviour with respect to uptake of all three elements. The greatest uptake observed was for 99Tc, followed by 77Se, with least uptake of 129I, reflecting the transformations and interactions with soil of the three isotopes. Unlike soil-derived Se and I, the available pools of 77Se, 99Tc and 129I were substantially depleted by plant uptake across the three cuts with lower concentrations observed in plant tissues in each subsequent cut. Comparison between total plant offtake and various soil species suggested that 77SeO42-, 99TcO4- and 129IO3-, in soluble and adsorbed fractions were the most likely plant-available species. A greater ratio of 127I/129I in the soil solid phase compared to the solution phase confirmed incomplete mixing of spiked 129I with native 127I in the soil, despite the extended incubation period, leading to poor buffering of the spiked available pools. Compared to traditional expressions of soil-plant transfer factor (TFtotal), a transfer factor (TFavailable) expressed using volumetric concentrations of speciated 'available' fractions of each element showed little variation with soil properties.
Assuntos
Agrostis , Monitoramento de Radiação , Fracionamento Químico , Iodo , Lolium , Selênio , Solo , Poluentes do Solo , TecnécioRESUMO
The use of low fishmeal/fish oil in marine fish diets affects dietary essential fatty acids (EFAs) composition and concentration and, subsequently, may produce a marginal deficiency of those fatty acids with a direct impact on the fish intestinal physiology. Supplementation of essential fatty acids is necessary to cover the requirements of the different EFAs, including the ones belonging to the n-6 series, such as arachidonic acid (ARA). ARA, besides its structural role in the configuration of the lipid classes of the intestine, plays an important role in the functionality of the gut-associated immune tissue (GALT). The present study aimed to test five levels of dietary ARA (ARA0.5 (0.5%), ARA1 (1%), ARA2 (2%), ARA4 (4%), and ARA6 (6%)) for European sea bass (Dicentrarchus labrax) juveniles in order to determine (a) its effect in selected distal intestine (DI) lipid classes composition and (b) how these changes affected gut bacterial translocation rates and selected GALT-related gene expression pre and post challenge. No differences were found between distal intestines of fish fed with the graded ARA levels in total neutral lipids and total polar lipids. However, DI of fish fed with the ARA6 diet presented a higher (P < 0.05) level of phosphatidylethanolamine (PE) and sphingomyelin (SM) than those DI of fish fed with the ARA0.5 diet. In general terms, fatty acid profiles of DI lipid classes mirrored those of the diet dietary. Nevertheless, selective retention of ARA could be observed in glycerophospholipids when dietary levels are low (diet ARA0.5), as reflected in the higher glycerophospholipids-ARA/dietary-ARA ratio for those animals. Increased ARA dietary supplementation was inversely correlated with eicosapentaenoic acid (EPA) content in lipid classes, when data from fish fed with the diets with the same basal composition (diets ARA1 to ARA6). ARA supplementation did not affect intestinal morphometry, goblet cell number, or fish survival, in terms of gut bacterial translocation, along the challenge test. However, after the experimental infection with Vibrio anguillarum, the relative expression of cox-2 and il-1ß were upregulated (P < 0.05) in DI of fish fed with the diets ARA0.5 and ARA2 compared with fish fed with the rest of the experimental diets. Although dietary ARA did not affect fish survival, it altered the fatty acid composition of glycerophospholipids and the expression of pro-inflammatory genes after infection when included at the lowest concentration, which could be compromising the physical and the immune functionality of the DI, denoting the importance of ARA supplementation when low FO diets are used for marine fish.
Assuntos
Ração Animal , Ácido Araquidônico , Bass/fisiologia , Dieta , Suplementos Nutricionais , Ácidos Graxos , Óleos de Peixe , Intestinos/fisiologia , Alimentos Marinhos , AnimaisRESUMO
BACKGROUND AND OBJECTIVES: The association between pollen counts and allergen levels in the air is controversial. Objectives: The aims of the study were to quantify total and major allergen levels of Phleum pratense and Olea europaea and to analyze their correlation with grass and olive pollen counts and the number of asthma attacks attended at Complejo Hospitalario Universitario, Cáceres, Spain. MATERIAL AND METHODS: A volumetric air sampler and a Burkard spore trap were used for pollen and aeroallergen collection during April- June 2011. Filters were extracted, and major allergens were quantified using enzyme-linked immunosorbent assay. RESULTS: May was the main grass pollination period, with a maximum peak of 1362 grains/m3 (May 13). The main pollination period for olive was April 30-May 20, with a maximum peak of 851 grains/m3 (May 11). A moderate correlation was observed between asthma exacerbations and grass pollen counts or Phleum total allergen levels; this became stronger when a 3-day offset was introduced. A significant association was observed between asthma exacerbations and total olive allergen or olive pollen grain levels when a 1-day offset was introduced. The maximum correlation (moderate-high) was observed 4 days and 6 days away from the maximum olive pollen peak and the maximum Ole e 1 peak level, respectively. CONCLUSIONS: This study reveals a significant correlation between grass and olive pollination and an increase in the number of visits to the emergency room for asthma attacks. The aerobiological pattern of allergen levels in the air is similar to that of pollen counts during the grass and olive pollination periods.
Assuntos
Alérgenos/imunologia , Asma/diagnóstico , Asma/imunologia , Olea/imunologia , Poaceae/imunologia , Pólen/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Asma/epidemiologia , Biomarcadores , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espanha/epidemiologia , Avaliação de Sintomas , Adulto JovemRESUMO
OBJECTIVES: Sarcopenia, defined as an age-associated loss of skeletal muscle function and muscle mass, occurs in approximately 6 - 22 % of older adults. This paper presents evidence-based clinical practice guidelines for screening, diagnosis and management of sarcopenia from the task force of the International Conference on Sarcopenia and Frailty Research (ICSFR). METHODS: To develop the guidelines, we drew upon the best available evidence from two systematic reviews paired with consensus statements by international working groups on sarcopenia. Eight topics were selected for the recommendations: (i) defining sarcopenia; (ii) screening and diagnosis; (iii) physical activity prescription; (iv) protein supplementation; (v) vitamin D supplementation; (vi) anabolic hormone prescription; (vii) medications under development; and (viii) research. The ICSFR task force evaluated the evidence behind each topic including the quality of evidence, the benefit-harm balance of treatment, patient preferences/values, and cost-effectiveness. Recommendations were graded as either strong or conditional (weak) as per the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Consensus was achieved via one face-to-face workshop and a modified Delphi process. RECOMMENDATIONS: We make a conditional recommendation for the use of an internationally accepted measurement tool for the diagnosis of sarcopenia including the EWGSOP and FNIH definitions, and advocate for rapid screening using gait speed or the SARC-F. To treat sarcopenia, we strongly recommend the prescription of resistance-based physical activity, and conditionally recommend protein supplementation/a protein-rich diet. No recommendation is given for Vitamin D supplementation or for anabolic hormone prescription. There is a lack of robust evidence to assess the strength of other treatment options.
Assuntos
Programas de Rastreamento/métodos , Sarcopenia/diagnóstico , Sarcopenia/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Sarcopenia/patologiaRESUMO
The aim of this study was to evaluate the effects of increasing dietary arachidonic acid (ARA) levels (from 1 to 6% of total fatty acids) on European sea bass (Dicentrarchus labrax) juveniles' growth performance, tissue fatty acid profile, liver morphology as well as long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, triglyceride and cholesterol synthesis and lipid transport. A diet with total fish oil (FO) replacement and defatted fish meal (FM) containing a 0.1-g ARA g-1 diet was added to the experimental design as a negative control diet. Dietary ARA inclusion levels below 0.2 g ARA g-1 diet significantly worsened growth even only 30 days after the start of the feeding trial, whereas dietary ARA had no effect on fish survival. Liver, muscle and whole body fatty acid profile mainly reflected dietary contents and ARA content increased accordingly with ARA dietary levels. Tissue eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels were positively correlated among them. Hepatic lipid vacuolization increased with reduced dietary ARA levels. Expressions of fatty acyl desaturase 2 and 3-hydroxy-3-methylglutaryl-coenzyme genes were upregulated in fish fed the negative control diet compared to the rest of the dietary treatments denoting the influence of ARA on lipid metabolism. Results obtained highlight the need to include adequate n-6 levels and not only n-3 LC-PUFA levels in European sea bass diets.
Assuntos
Ácido Araquidônico/farmacologia , Bass/crescimento & desenvolvimento , Suplementos Nutricionais , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ácido Araquidônico/administração & dosagem , Ácido Araquidônico/química , Dieta/veterinária , Ácidos Graxos/química , Óleos de Peixe/químicaRESUMO
The aim of this study was to assess the effects of low levels of dietary fish meal (FM) and fish oil (FO) on disease resistance and gut associated lymphoid tissue (GALT) response after an experimental intestinal infection with V. anguillarum in European sea bass (Dicentrarchus labrax) For that purpose, sea bass juveniles were fed one of four diets containing combined levels of FO and FM as follows: 20%FM/6%FO, 20%FM/3%FO, 5%FM/6%FO and 5%FM/3%FO during 153 days. At the end of the feeding trial, fish were subjected to either an in vivo exposure to a sub-lethal dose of V. anguillarum via anal inoculation or to an ex vivo exposure to V. anguillarum. Additionally, inducible nitric oxide synthase (iNOS) and tumor necrosis factor α (TNFα) gut patterns of immunopositivity were studied. Growth performance was affected by dietary FM level, however ex vivo gut bacterial translocation rates and survival after the in vivo challenge test were affected by dietary FO level. After 5 months of feeding, low dietary FM levels led to a posterior gut up-regulation of interleukin-1ß (IL-1ß) and TNFα, major histocompatibility complex-II (MHCII) and cyclooxygenase-2 (COX2), which in turn reduced the gut associated lymphoid tissue (GALT) capacity of response after 24 h post infection and conditioned European sea bass capacity to recover gut homeostasis 7 days post infection. Immunoreactivity to anti-iNOS and anti-TNFα presented a gradient of increased immunopositivity towards the anus, regardless of the dietary FM/FO fed. Strong positive anti-TNFα isolated enterocytes were observed in the anterior gut in relation to low levels of dietary FM/FO. Submucosa and lamina propria immunoreactivity grade was related to the amount of leucocyte populations infiltrated and goblet cells presented immunopositivity to anti-iNOS but not to anti-TNFα. Thus, reducing FO content from 6% to a 3% by VO in European sea bass diets increases ex vivo and in vivo gut bacterial translocation rates, whereas reducing FM content from 20% down to 5% up-regulates the expression of several posterior gut inflammation-related genes conditioning fish growth and GALT capacity of response after bacterial infection.
Assuntos
Bass/imunologia , Suplementos Nutricionais , Resistência à Doença , Doenças dos Peixes/imunologia , Óleos de Peixe/imunologia , Enteropatias/veterinária , Vibrioses/veterinária , Ração Animal , Animais , Dieta/veterinária , Enteropatias/imunologia , Vibrio/fisiologia , Vibrioses/imunologiaRESUMO
The main objective of this study was to assess the effects of graded levels of dietary arachidonic acid (ARA), supplemented from alternative sources, on fatty acid composition of plasma and head kidney leucocytes of European sea bass (Dicentrarchus labrax). For that purpose, sea bass juveniles were fed four diets containing graded levels of ARA as follows: 0.5% (ARA0.5), 1% (ARA1), 2% (ARA2) and 4% (ARA4) during 60 days. At the end of the feeding trial fatty acid profiles of plasma and head kidney leucocytes were analyzed. Besides, plasma prostaglandins levels, head kidney leucocytes respiratory burst activity; peroxidase activity and phagocytic index were assayed. Reducing dietary ARA levels below 1% markedly reduced European sea bass growth performance. However, fish fed diet ARA0.5 tried to compensate this dietary ARA deficiency by a selective deposition of ARA on plasma and head kidney leucocytes, reaching similar levels to those fish fed diet ARA1 after 60 days of feeding. Nevertheless, head kidney phagocytic capacity was reduced as dietary ARA content in relation not only to variations on membrane composition but also to changes on fish basal prostaglandins levels. Results obtained demonstrated the importance to supply the necessary quantity n-6 LC-PUFA, and not only n-3 LC-PUFA levels, in European sea bass diets, in relation to not only growth performance but also immune system function.
Assuntos
Ácido Araquidônico/metabolismo , Bass/imunologia , Suplementos Nutricionais , Ácidos Graxos/sangue , Rim Cefálico/imunologia , Leucócitos/imunologia , Prostaglandinas/sangue , Ração Animal/análise , Animais , Ácido Araquidônico/administração & dosagem , Bass/sangue , Bass/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Distribuição AleatóriaRESUMO
Vestibular rehabilitation is effective and safe in patients with instability. However, there is insufficient evidence for distinguishing between efficacies of different dosage of therapies. Therefore, the aim of the present study was to verify whether there were differences between two computerised dynamic posturography (CDP) therapies of different numbers of sessions, in order to establish the optimal strategy. We conducted a prospective, comparative study of two different dosage of CDP therapy (a 5-session group and another of 10-session group) in patients with instability due to chronic unilateral peripheral vestibular disorder. We used balanced block randomisation to include 13 patients in each group. Improvement was assessed using the Dizziness Handicap Inventory and the CDP with the sensorial organisation test (SOT) and limits of stability (LOS). We found a statistically significant improvement in both groups in composite score, visual and vestibular input (SOT); and in reaction time, distance and directional control (LOS). If we compare the groups regarding these improvements, we found that 10-session group showed a greater benefit in distance covered and directional control of LOS. Since significant improvement is obtained with only five sessions, we believe this to be the optimal number of treatment sessions for most patients with chronic unilateral peripheral vestibular disorder. Nevertheless, those patients with more reduced limits of stability, and consequently greater likelihood of falling as a result of their diminished base of support, are candidates for rehabilitation protocols with a greater number of sessions.
Assuntos
Biorretroalimentação Psicológica/métodos , Labirintite/reabilitação , Equilíbrio Postural , Doenças Vestibulares/reabilitação , Neuronite Vestibular/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Resultado do TratamentoAssuntos
Antioxidantes/farmacologia , Bass/metabolismo , Ácidos Docosa-Hexaenoicos/toxicidade , Animais , Ácido Ascórbico/farmacologia , Bass/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Larva/crescimento & desenvolvimento , Larva/metabolismo , Selênio/farmacologia , Vitamina E/farmacologiaRESUMO
In previous studies, we observed dystrophic alterations in muscle of 48-day-old sea bass fed imbalanced docosahexaenoic acid (DHA) and vitamin E diets. To understand the whole pathological process associated with oxidative stress, a histological study was performed by feeding 14-day-old sea bass larvae with microdiets containing different ratios of DHA/vitamin E (1/150, 5/150 and 5/300) for a period of 21 days. Larvae fed diet 1/150 showed no lesions in contrast to larvae fed diets 5/150 and 5/300 where the highest incidence of muscle lesions and thiobarbituric acid reactive substances (TBARS) content was observed. Semithin sections revealed focal lesions consisting of degenerated fibres with hypercontracted myofilaments and extensive sarcoplasm vacuolization affecting both red and white muscle. Ultrathin sections of degenerating muscle fibres showed diffuse dilatation of sarcoplasmic reticulum, disorganized myofilaments and autophagic vacuoles containing myelin figures and dense bodies. Additionally, some macrophages were observed among injured fibres as numerous satellite cells. Results from the study agree with those obtained from previous work, proving the pathological potential of free radicals in sea bass larvae musculature. Moreover, high vitamin E inclusion could not completely protect cell membranes from free radicals action.
Assuntos
Bass/fisiologia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Músculo Esquelético/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/administração & dosagem , Animais , Dieta/veterinária , Larva/efeitos dos fármacos , Larva/fisiologia , Microscopia Eletrônica de Transmissão/veterinária , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Espanha , Espectrofotometria/veterináriaRESUMO
DHA deficiency has been related to skeletal malformations in fish, but high DHA levels have produced controversial results that could relate to the oxidative status of fish tissues in the different reports. In the present study, gilthead seabream (Sparus aurata) larvae were fed deficient, adequate or high DHA levels, or high DHA levels supplemented with the antioxidant α-tocopherol. Larvae fed deficient DHA levels tended to be smaller, and showed the highest incidence of urinary bladder calculi, lordosis and kyphosis and the lowest number of mineralised vertebrae for any given size class. Elevation of dietary DHA increased larval growth and significantly enhanced the expression of the insulin-like growth factor 1 (IGF-1) gene. However, a DHA level increase up to 5 % raised the degree of lipid oxidation in larval tissues and deformities in cranial endochondral bones and in axial skeletal haemal and neural arches. The increase in dietary α-tocopherol supplementation in high-DHA feeds reduced again the occurrence of skeletal deformities. Moreover, the expression of genes coding for specific antioxidants such as catalase, superoxide dismutase or glutathione peroxidase, which neutralised reactive oxygen substances formed by increased dietary DHA, was significantly decreased in larvae fed high α-tocopherol levels. These results denoted the importance of DHA for early bone formation and mineralisation. Low dietary DHA levels delay early mineralisation and increase the risk of cranial and axial skeletal deformities. Excessive DHA levels, without an adequate balance of antioxidant nutrients, increase the production of free radicals damaging cartilaginous structures before bone formation.
Assuntos
Densidade Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Dourada , alfa-Tocoferol/farmacologia , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Osso e Ossos/anormalidades , Osso e Ossos/metabolismo , Dieta , Gorduras na Dieta/farmacologia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/deficiência , Expressão Gênica/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Cifose/etiologia , Larva/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Lordose/etiologia , Minerais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Dourada/crescimento & desenvolvimento , Dourada/metabolismo , Cálculos da Bexiga Urinária/etiologiaRESUMO
The effects of dietary mannan oligosaccharides (MOS; 4 g kg(-1) ; Bio-Mos, Alltech Inc, USA) in diets for European sea bass, Dicentrarchus labrax (L.), juveniles in relation to disease and stress resistance, combining intestinal infection with Vibrio anguillarum and stress challenge by confinement, were assessed in this study. After 8 weeks of MOS supplementation, fish were exposed to a pathogen challenge test against V. anguillarum by direct gut inoculation combined with a confinement stressor panel. Cumulative mortality of fish fed MOS caused by anally inoculated V. anguillarum decreased from 66% to 12.5% and from 54.1% to 25% in infected and infected + stressed fish, respectively, compared to fish fed control diet. Results for European sea bass revealed a positive effect of MOS dietary inclusion on disease resistance, in terms of cumulative mortality, against gut inoculated V. anguillarum, as well as reduced effects of stress on microbiota diversity. Both of these findings, together with the enhanced innate immune response and the higher gut mucus production and density of eosinophil granulocytes in gut mucosa obtained in previous studies after MOS supplementation (Torrecillas et al. 2007, 2011a,b) suggest that general reinforcement of the innate immune system, and particularly of the intestinal barrier efficiency, is the main defence mechanism of European sea bass fed MOS against pathogenic microorganisms.
Assuntos
Bass/imunologia , Suplementos Nutricionais , Doenças dos Peixes/imunologia , Mananas , Estresse Fisiológico , Vibrioses/veterinária , Animais , Doenças dos Peixes/mortalidade , Hidrocortisona/sangue , Intestinos/microbiologia , Análise de Sobrevida , Vibrio , Vibrioses/imunologia , Vibrioses/mortalidadeRESUMO
The present study examined the effects of a severely restricted diet during the pre- and postnatal periods with later nutritional rehabilitation on orexin hypothalamic neurons in male and female Wistar rats. Immunocytochemistry was used to reveal orexin-immunoreactive (orexin-ir) cells in the ventromedial hypothalamus (VMH), dorsomedial hypothalamus (DMH), lateral hypothalamic area (LH) and the perifornical nucleus (PF). Dietary restriction decreased the number of orexin-ir cells in the LH, whereas DMH or PF orexin-ir populations were not affected in either male or female rats. Nutritional rehabilitation resulted in a differential recovery that depended on the period during which rehabilitation occurred and on the sex of the animal. In summary, our study suggests that the hypothalamic nuclei implicated in eating behavior present a differential vulnerability to adverse environmental conditions during development. Specifically, among the studied nuclei only the LH orexin-ir cells were sensitive to severe food deprivation during development in male and female rats. These results suggest that starvation interferes with developmental events that occur during CNS sexual differentiation.
Assuntos
Hipotálamo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Desnutrição/metabolismo , Neuropeptídeos/metabolismo , Animais , Feminino , Alimentos , Masculino , Desnutrição/reabilitação , Neurônios/metabolismo , Orexinas , Ratos , Ratos Wistar , Caracteres Sexuais , Fatores de TempoRESUMO
The mode of action of highly unsaturated fatty acids (HUFA) in regulating gilthead sea bream (Sparus aurata) head kidney (HK) cortisol production was studied through in vitro trials using a dynamic superfusion system. Fish were previously fed with different diets containing several inclusion levels of linseed oil (LO) or soyabean oil (SO) for 26 weeks. Five diets were tested; anchovy oil was the only lipid source for the control diet (fish oil, FO) and two different substitution levels (70 and 100 %) were tested using either LO or SO (70LO, 70SO, 100LO and 100SO). Fatty acid compositions of the HK reflected the dietary input, thus EPA, DHA, arachidonic acid and n-3 HUFA were significantly (P < 0·05) reduced in fish fed vegetable oils compared with fish fed the FO diet. Feeding 70 or 100 % LO increased significantly (P < 0·05) cortisol release in HK after stimulation with adrenocorticotrophic hormone (ACTH), while feeding SO had no effect on this response. Cortisol stimulation factor (SF) was increased in fish fed the 70LO and 100LO diets compared with fish fed the control diet. Moreover, eicosanoid inhibition by incubating the HK tissue with indomethacin (INDO) as a cyclo-oxygenase (COX) inhibitor, or nordihydroguaiaretic acid (NDGA) as a lipoxygenase (LOX) inhibitor, significantly reduced (P < 0·05) the cortisol release after ACTH stimulation in the 70LO and 100LO diets. Cortisol SF was reduced in the FO, 70LO and 100LO diets when incubating the HK with INDO or NDGA, while it was increased in the 70SO diet. The present results indicate that changing the fatty acid profile of gilthead sea bream HK by including LO and/or SO in the fish diet affected the in vitro cortisol release, and this effect is partly mediated by COX and/or LOX metabolites.
Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Hidrocortisona/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Óleo de Semente do Linho/administração & dosagem , Dourada/fisiologia , Óleo de Soja/administração & dosagem , Animais , Inibidores de Ciclo-Oxigenase/farmacologia , Ácidos Graxos/administração & dosagem , Ácidos Graxos/análise , Óleos de Peixe/administração & dosagem , Óleos de Peixe/química , Técnicas In Vitro , Indometacina/farmacologia , Rim/enzimologia , Óleo de Semente do Linho/química , Lipoxigenase/metabolismo , Inibidores de Lipoxigenase/farmacologia , Masoprocol/farmacologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Óleo de Soja/químicaRESUMO
Commercial gilthead sea bream feeds are highly energetic, fish oil traditionally being the main lipid source. But the decreased fish oil production together with the increased prices of this oil encourages its substitution by vegetable oils, imposing new nutritional habits to aquaculture species. Partial replacement of fish oil by vegetable oils in diets for marine species allows good feed utilization and growth but may affect fish health, since imbalances in dietary fatty acids may alter fish immunological status. The effect of dietary oils on different aspects of fish immune system has been reported for some species, but very little is known about the effect of dietary oils on immune-related genes expression in fish. Thus, the objective of this study was to elucidate the role of dietary oils on the expression of two pro-inflammatory cytokines, Tumor Necrosis Factor-α (TNF-α) and Interleukine 1ß (IL-1ß) on intestine and head kidney after exposure to the bacterial pathogen Photobacterium damselae sp. piscicida. For that purpose, 5 iso-nitrogenous and iso-lipidic diets (45% crude protein, 22% crude lipid content) were formulated. Anchovy oil was the only lipid source used in the control diet (FO), but in the other diets, fish oil was totally (100%) or partially (70%) substituted by linseed (rich in n-3 fatty acids) or soybean (rich in n-6 fatty acids) (100L, 100S, 70L, 70S). Fish were fed experimental diets during 80 days and after this period were exposed to an experimental intestinal infection with the pathogen. Serum and tissue samples were obtained at pre-infection and after 1, 3 and 7 days of infection. RNA was extracted and cDNA was synthesized by reverse transcription from intestine and head kidney and the level expression of TNF-α and IL-1ß were assayed by using quantitative real time PCR. The expression level of genes analysed was represented as relative value, using the comparative Ct method (2(-ΔΔCt)). Serum anti-bacterial activity was measured as serum bactericidal capacity and lysozyme activity. Reduction of FO tends to reduce basal (pre-infection) genetic expression of both cytokines. However, complete FO replacement caused an over expression of both pro-inflammatory cytokines, particularly after 3 days of induced infection in fish fed soybean oil based diets. On the other hand, fish fed diets with low content of n-6 fatty acids showed better serum bactericidal capacity after infection, suggesting that the substitution of fish oil by vegetable oils containing high levels of n-6 fatty acids may induce imbalances on fish immune response, leading to a lower potential response against infections.
Assuntos
Gorduras Insaturadas na Dieta/administração & dosagem , Interleucina-1beta/sangue , Dourada/imunologia , Fator de Necrose Tumoral alfa/sangue , Animais , Gorduras Insaturadas na Dieta/imunologia , Gorduras Insaturadas na Dieta/metabolismo , Óleos de Peixe/metabolismo , Imunidade Humoral/imunologia , Interleucina-1beta/genética , Photobacterium/imunologia , Óleos de Plantas/administração & dosagem , Óleos de Plantas/metabolismo , RNA/química , RNA/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Dourada/metabolismo , Fator de Necrose Tumoral alfa/genéticaRESUMO
In the context of the study on plant defensive compounds we have isolated the main alkaloid from Hippeastrum puniceum (Amaryllidaceae), 3-O-acetyl-narcissidine (1), and its biological activities tested against two divergent insect species and several plant species. 1 was isolated from the bioactive alkaloidal fraction of H. puniceum. Its chemical structure was established by spectroscopic analysis. The biological activity tests showed that 1 is an antifeedant against the polyphagous insect Spodoptera littoralis but not against the olyphage Leptinotarsa decemlineata. Furthermore, the root growth of Amaranthus hypochondriacus, Rottboellia cochinchinensis, Panicum maximum and Solanum lycopersicum was significantly affected by 1. These results suggest a plant protective role for H. puniceum alkaloids.