3,163 research outputs found

    Swine inmune response to Salmonella enterica serovar typhimurium. A functional genomics approach

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    Genetic improvement of the resistance to infectious diseases represents an essential step for the development of sustainable and economically viable animal production systems. Control of salmonellosis in swine herds generates increased production costs and public health issues due to the risk of dispersal of antibiotic resistant strains. Therefore, the breeding of resistant animals, in combination with good hygiene practices offers a promising strategy to fight against Salmonella in pigs. Recently, functional genomics approaches combining the power of gene mapping technologies, gene expression studies and modern bioinformatics tools have begun to contribute to a better understanding of the host response to microbial diseases. In light of this, this thesis aimed to identify and describe the molecular pathways and interactions involved in the porcine intestinal immune response to Salmonella enterica serovar Typhimurium (S. Typhimurium). The first, second and third studies that constitute this thesis aimed to explore the molecular mechanisms occurring in porcine mesenteric lymph-nodes (MLN) at 1, 2 and 6 days post-infection (dpi) with S. Typhimurium. Firstly, the differential expression of immune-related genes was analysed in correlation with changes in tissue morphology and pathogen burden. Results revealed that infection resulted in a substantial infiltration of phagocytes and up-regulation of pro-inflammatory genes. Of note, host defence mechanisms led to a relevant reduction of S. Typhimurium load in tissue, but pathogen was found to maintain itself in MLN at 6 dpi. Subsequently, DIGE-based proteomics was carried out, uncovering that infection caused changes in abundance of proteins involved in diverse host cellular functions, leading to the induction of processes such as phagocyte infiltration, cytoskeleton remodelling, pyroptosis and antigen presentation in infected MLN. Finally, host response to infection was accessed by microarrays analysis and then complemented with gene expression data from pathogen found in tissue. The conjunctive analysis of both parties involved in infection revealed that although S. Typhimurium was able to express virulence factors in porcine MLN, host succeeded in counteracting pathogen strategies by modulating infected cell death and inducing an early cytotoxic response. The forth and fifth studies reported in this thesis were focused on the role of porcine Peyer’s Patches (PP) upon S. Typhimurium infection. Initially, laser microdissection coupled to qPCR technology uncovered that both innate and adaptive immunity mechanisms are effectively triggered in PP follicles during infection. Afterwards, microarray analysis was carried out to better-explain results from this preliminary approach. It could be confirmed that the bacterial challenge provoked a remarkable inflammatory response and the establishment of multiple...La mejora de la resistencia genética a las enfermedades infecciosas representa una etapa fundamental para el desarrollo de sistemas de producción animal económicamente viables y sostenibles. El control de la salmonelosis porcina genera elevados costes de producción y supone un riesgo para la salud pública por la posibilidad de desarrollo y dispersión de cepas resistentes a antibióticos. Por lo tanto, la cría de animales resistentes, asociada a buenas prácticas de higiene durante la producción, representa una estrategia prometedora para la lucha contra infecciones por Salmonella en cerdos. Recientemente, la genómica funcional, al combinar la potencia de las tecnologías de mapeo genético, los estudios de expresión génica y las modernas herramientas bioinformáticas empieza a contribuir a una mejor comprensión de la respuesta del hospedador a las infecciones microbianas. Debido a esto, en esta tesis doctoral se planteó como objetivo identificar y describir las rutas e interacciones moleculares involucradas en la respuesta a la infección con Salmonella enterica serovar Typhimurium (S. Typhimurium) en la especie porcina. Los tres primeros estudios que componen esta tesis doctoral tuvieron como objetivos explorar los mecanismos moleculares que ocurren en los nódulos linfáticos mesentéricos (NLM) porcinos tras 1, 2 y 6 días post-infección (dpi) con S. Typhimurium. Inicialmente, la expresión diferencial de genes relacionados con la respuesta inmunitaria fue analizada y correlacionada con cambios en la morfología tisular y carga de patógeno. Los resultados revelaron que la infección resultó en una abundante infiltración de fagocitos y sobre-expresión de genes pro-inflamatorios. Notablemente, una significativa reducción de la presencia de la bacteria en el tejido fue observada, en asociación con la activación de los mecanismos de defensa del hospedador. A pesar de ello, el patógeno logró mantenerse en los NLM, siendo detectado a los 6 dpi. A continuación, un análisis proteómico mediante DIGE fue llevado a cabo, poniendo de manifiesto que la infección resultó en cambios en la abundancia de proteínas involucradas en distintas funciones celulares del hospedador, promoviendo en los NLM infectados la inducción de procesos como la infiltración de fagocitos, remodelación del citoesqueleto, piroptosis y presentación antigénica. Finalmente, la respuesta del hospedador a la infección fue evaluada mediante análisis de micromatrices y los resultados obtenidos fueron complementados con datos de expresión génica procedentes del patógeno presente en tejido. En conjunto, el estudio reveló que, aunque S. Typhimurium expresa factores de virulencia en NLM porcinos, el hospedador contrarresta de forma efectiva las estrategias de virulencia del patógeno, mediante la modulación de la muerte celular de células infectadas y la inducción de una respuesta citotóxica temprana..

    ATRIBUTOS FÍSICOS DE UM LATOSSOLO VERMELHO DISTROFÉRRICO DA CULTURA DO MILHO EM FUNÇÃO DA CONSORCIAÇÃO COM PLANTAS DE COBERTURA E ADUBAÇÃO NITROGENADA EM SISTEMA DE SEMEADURA DIRETA

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    O Sistema de semeadura direta (SSD) tem como pressuposto a exigência de cobertura vegetal permanente sobre o solo e, em condições climáticas favoráveis à decomposição dos resíduos orgânicos, visando elevar a produtividade com sustentabilidade ambiental. O nitrogênio é o nutriente requerido em maior quantidade pelas gramíneas, destacando-se a cultura do milho e, por isso, em muitas situações, não é fornecido adequadamente, havendo necessidade de usar outras fontes suplementares desse nutriente. Destacando-se, a utilização isolada ou combinada de adubos minerais, orgânicos, gramíneas e leguminosas. Este estudo teve por objetivo avaliar os atributos físicos de um Latossolo Vermelho distroférrico, textura argilosa (EMBRAPA, 2006). O delineamento estatístico foi em blocos casualizados com parcelas sub-subdivididas e quatro repetições, sendo três plantas de cobertura com quatro doses de N. Os resultados foram submetidos à análise de variância pelo teste F, de acordo com o delineamento em parcelas subdivididas. O resultado da análise de variância significativo a 5 % ou a 1% de probabilidade, as médias dos tratamentos foram comparadas utilizando-se o teste de Tukey, a 5% de probabilidade

    Nutritive value of brachiaria forage intercropping with eucalyptus in a silvopastoral system in the Brazilian cerrado biome

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    The objective of this study was to evaluate a SPS located in the Cerrado, in relation to forage production characteristics and forage nutritive value during the drought summer period and beginning of the rainy season. An experiment was conducted in Confins, Minas Gerais, Brazil in order to evaluate the forage produced by a silvopastoral system. The system was composed of Eucalyptus tree species (150 trees/ha) and Brachiaria brizantha cv. Marandu forage. The pasture was sampled during the months of May, July and November of 2009, and production (quantitative and qualitative) and bromatological composition were determined. This silvopastoral system appeared to be a sustainable option for animal production in areas with little rainfall. This study suggests that it is possible to observe a considerable increase in nutrient concentrations in shaded forage using silvopastoral systems. This increase was witnessed even in drought conditions, where forage protein values were high, which is important in meeting the maintenance requirements of ruminants. This is especially important in the Cerrado biome, which frequently experiences droughts. The presence of the tree species Eucalyptus did not interfere in forage dry matter production Trees appeared to reduce forage water stress while simultaneously increasing mineral concentrations. This silvopastoral system appeared to be a sustainable option for animal production in areas with little rainfall

    INFLUÊNCIA DE EXERCÍCIOS POSTURAIS SOBRE A FORÇA MUSCULAR RESPIRATÓRIA EM JOVENS SAUDÁVEIS

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    Postural changes are a public health problem that can interfere directly with ventilatory mechanics, pilates exercises and isostretching may be beneficial for postural and ventilatory improvement. To analyze effects of combined exercises of the isostretching and Pilates methods on respiratory muscle strength (RMS), lung function and postural changes. Being twenty evaluated individuals, posture, RMS, pulmonary function and reevaluated after a training for 10 weeks. Twenty individuals, classified as BMI and physical activity level showed a significant difference between RMS, when compared to pre and post training values. The MIP presented (p = 0.002) in the same way as the MEP (p = 0.006). Each postural change may interfere in a different way in mechanics and new studies may bring better understanding of this mechanics and assist in the development of effective therapies. It is determined that postural works based on isostretching and pilates methods improve respiratory muscle strength.Alterações posturais são problema de saúde pública que pode interferir de forma direta na mecânica ventilatória, exercícios de Pilates e isostretching podem ser benéficos para a melhora postural e ventilatória. Analisar efeitos de exercícios combinados dos métodos de isostretching e Pilates sobre a força muscular respiratória (FMR), função pulmonar e alterações posturais. Sendo 20 indivíduos avaliados, postura, FMR, função pulmonar e reavaliados após um treinamento por 10 semanas. Os  20 indivíduos, classificados IMC e nível de atividade física apresentaram diferença entre FMR significante, quando comparados os valores pré e pós treinamento. A PiMáx apresentou (p=0,002) da mesma forma que a PeMáx (p=0,006). Cada alteração postural pode interferir de uma forma diferente na mecânica e novos estudos podem trazer melhor compreensão dessa mecânica e auxiliar no desenvolvimento de terapias eficazes. Determina-se que exercícios posturais baseados nos métodos de isostretching e pilates melhoram a força muscular respiratória

    Cholinergic Signaling Exerts Protective Effects in Models of Sympathetic Hyperactivity-Induced Cardiac Dysfunction

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    Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i) the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO), and ii) the alpha(2A)/alpha(2C)-drenergic receptor knockout (KO) mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. alpha(2A)/alpha(2C)-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease

    Acute Effects of Different Weight Training Methods on Energy Expenditure in Trained Men

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    Introduction: The Weight training has been widely used as strategy of reduction and weight control, so the energy expenditure (EE) contributes significantly to this process. Objective: To compare the acute effects of the circuit method (CM) with the traditional method (TM) on the EE. Methods: This research had a randomized crossover design; the sample consisted of ten adult men recreationally trained aged between 18 to 29 years. There were two experimental sessions with seven-day wash out: in CM the exercises were performed by alternating segment in form of stations, during TM the exercises were performed in consecutive sets. Both training methods followed the same sequence of eight exercises with the same total work: 60% of 1RM, 24 sets/stations and ten repetitions. The collection of blood lactate was performed at rest and the every three sets/stations. The expired air was collected per 30 minutes before and ~31 minutes during all the training sessions. The aerobic exercise (AEEE, kj) and of rest interval (RIEE, kj) EEs were estimated by indirect calorimetry by mea- suring oxygen consumption and the anaerobic EE (AEE, kj) by blood lactate concentration ([La]). The total EE (TEE, kj) was recorded by the sum of AEE, RIEE and AEE. Results: Data showed that the AEE was greater in TM than the CM; however, the AEEE, RIEE and the TEE were not significantly different between the methods. The TM presented higher [La] than the CM. Conclusion: We conclude that the CM and TM produces similar EE during and post-workout, however, one realizes that the TM uses more anaerobic system than the MC

    Academias ao ar livre: caracterização do perfil dos frequentadores e do padrão de utilização

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    O presente estudo teve por objetivo identificar o perfil dos frequentadores e o padrão de uso das academias ao ar livre (AAL) de Cláudio-MG, visando fornecer subsídios para melhorar a satisfação de seus usuários. Para isso foram entrevistados usuários de duas AAL do município, os respondentes foram escolhidos ao acaso e entrevistados pessoalmente. Na entrevista foi utilizado um questionário semiestruturado com perguntas sobre os usuários, frequência e sugestões para a utilização do espaço. Constatou-se que: 65,8% são mulheres; 58,9% são adultos (20 a 59 anos); 56,2% são solteiros; 37,0% possuem ensino fundamental incompleto e 28,8% ensino médio completo; 45,2% são trabalhadores ativos e 32,9% estudantes. Apresentam boas condições de saúde, com 58,9% dos usuários muito satisfeitos com a própria saúde; 45,2% possuindo peso adequado; 90,4% sem problemas com hipertensão e 95,9% não apresentando diabetes. O uso da academia segue o seguinte padrão: 97,5% dos frequentadores utilizam pelo menos um equipamento; 75,3% vão à academia de 1 a 4 vezes por semana; 75,3% frequentam a AAL de 2ª a 6ª feira. Com relação à socialização, 78,1% vão à academia acompanhados e 50,7% dizem ter conhecido alguém do bairro na academia. As principais reivindicações dos usuários foram: manutenção da área verde e dos equipamentos; falta de instrução para o uso dos equipamentos e a falta de bebedouros no local. Assim, verificou-se que são necessárias melhorias para que estes locais possam oferecer melhores condições de uso pela comunidade
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