Trypanosoma cruzi Infection in Non-Human Primates

For decades, non-human primates (NHPs) have been employed as experimental models to study many aspects of human diseases. They are the closest genetically to humans of any of the models applied in biomedical research; therefore, many authors have published scientific work regarding these animals and infectious diseases, including tuberculosis, AIDS, and tropical diseases. Among these, Chagas disease has caught the attention of many researchers all over the world. Recent studies have demonstrated great similarities with the human pathology, including cardiomyopathy and exacerbated pro-inflammatory response. Besides being genetically close to humans, NHP have a great probability to be naturally infected by Trypanosoma cruzi, which turns them into more interesting models to study Chagas disease mechanisms

Physiology and Pathology of Infectious Diseases: The Autoimmune Hypothesis of Chagas Disease

Infectious pathologies are a group of diseases that contribute with great impact on public health worldwide. Among the various diseases, some have a higher epidemiological importance, since their morbidity and mortality are very significant. In addition to the usual immune response, mounted against noxious agents, there is still the concept of infection-induced autoimmunity. Autoimmune diseases are defined as illnesses in which the evolution from benign to pathogenic autoimmunity takes place. However, proving a disease to be of autoimmune etiology is not a simple task. It is well known that both genetic influences and environmental factors trigger autoimmune disorders. However, some theories are still under great discussion. One of the most intriguing self-induced disorders is the hypothesis of autoimmunity during Chagas disease. Since the mid-1970s, the Chagas autoimmunity hypothesis has been considered an important contributor to the complex immune response developed by the host and triggered by Trypanosoma cruzi. New ideas and findings have strengthened this hypothesis, which has been reported in a series of publications from different groups around the world. The aim of this chapter is to discuss the mechanisms involving autoimmunity development during Chagas disease

Perfis de proteínas e carboidratos de silagem de capim 'Massai' com polpa cítrica peletizada e inoculante microbiano

The objective of this work was to evaluate the effects of the inclusion of pelleted citrus pulp and microbial inoculant on the fermentation characteristics, carbohydrate and protein fractionation, and total digestible nutrient contents of 'Massai' grass (Megathyrsus maximus × Megathyrsus infestus) silage. The experimental design was completely randomized, in a 2×4 factorial arrangement (application or not of inoculant × 0, 10, 20, and 30% citrus pulp) with five replicates. There was an increase in dry matter recovery as affected by citrus pulp levels. The values obtained for pH and ammonia nitrogen indicated an adequate fermentation process. Under increasing citrus pulp levels, there was a reduction in neutral detergent fiber and an increase in nonfibrous carbohydrate contents and in protein linked to fiber. Total digestible nutrient content reaches a peak of 513.1 g kg-1 with the inclusion of 12.50% citrus pulp. The microbial inoculant, when isolated, does not influence carbohydrate and protein profiles. Inclusions between 10 and 20% citrus pulp are able to maintain adequate fermentative parameters and improve the digestible nutrient profile, with an adequate dry matter recovery.O objetivo deste trabalho foi avaliar os efeitos das inclusões de polpa cítrica peletizada e de inoculante microbiano sobre características fermentativas, fracionamento de carboidratos e proteínas, e teores de nutrientes digestíveis totais de silagem de capim 'Massai' (Megathyrsus maximus × Megathyrsus infestus). O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 2×4 (aplicação ou não de inoculante × 0, 10, 20 e 30% de polpa cítrica), com cinco repetições. Houve aumento da recuperação de matéria seca em função dos níveis de polpa cítrica. Os valores obtidos para pH e nitrogênio amoniacal indicaram adequado processo fermentativo. Sob níveis crescentes de polpa cítrica, houve redução dos teores de fibra insolúvel em detergente neutro e aumento do teor de carboidratos não fibrosos e proteína ligada à fibra. O teor de nutrientes digestíveis totais atinge ponto máximo de 513,1 g kg-1 com a inclusão de 12,50% de polpa cítrica. O inoculante microbiano, quando isolado, não influencia os perfis de carboidratos e proteínas. Inclusões entre 10 e 20% de polpa cítrica são capazes de manter parâmetros fermentativos adequados e melhorar o perfil de nutrientes digestíveis, com adequada recuperação de matéria seca

MODELS GENERATED BY MULTIPLE REGRESSION IN FILLING METEOROLOGICAL DATA FAILURES IN AN AUTOMATIC METEOROLOGICAL STATION IN ALAGOAS

The objective of this study was to evaluate the multiple regression method to fill in the faults of the following meteorological variables: Average Air Temperature (Tmean), Relative Humidity (RHmean), and Rain Precipitation (Prec). Multiple regression was considered using different models, through the different cofactors evaluated (varying Tmean, RHmean, Dew Point, Pressure and Prec), generating four different multiple regression models for each meteorological variable studied. The models were statistically compared by Mean Absolute Error (MAE), Pearson's coefficient (r), agreement index (d) and Camargo and Sentelhas index (c). The results presented showed that multiple regression can be reliably used in Tmean, RHmean in Models 2, 3 and 4 (R> 0.90). The Precipitation variable had a coefficient of determination below 50% (R2 <0.50) and Model 2 obtained a p value greater than 1% in the Intercept (p = 0.012) and in the Pressure cofactor (p = 0.015). It cannot be used to correct Rainfall faults. Model 2 (except for Prec) presented better statistical coefficients and can be used to correct faults in the automatic station of Maceió, Alagoas

Advances in the evaluation of pastures cultivated with tropical forages in Brazil: A Review

Objetivou-se nesta revisão apresentar os conceitos e pesquisas atuais sobre os principais métodos para avaliação do dossel forrageiro em ambientes de pastagens cultivadas com plantas forrageiras tropicais. Na avaliação de pastagens, o estudo sobre variáveis que afetam diretamente o desempenho produtivo dos animais, tem sido priorizado, e deste modo, existem alguns fatores determinantes sobre o desempenho do sistema de produção, sendo que todos buscam um maior consumo da forragem e melhor desempenho dos animais. Um dos fatores determinantes para estimativa da capacidade de suporte de uma pastagem, é a obtenção da massa de forragem, sendo que o método mais preciso para estimar a massa de forragem de uma pastagem consiste na colheita de todo o material presente na área a ser avaliada. No entanto, este possui limitações operacionais para execução em grandes áreas, o que fez com que, métodos indiretos com base em tecnologias de informação geográfica e modelagem fossem amplamente estudados. Além das características de produção, características morfogênicas e estruturais podem interferir diretamente sobre a eficiência do sistema, de modo que, caracterizam o ecossistema pastagem, e podem predizer informações importantes como a vida útil de uma pastagem e consumo dos animais. Deste modo, a importância das metodologias para avaliação de pastagens contribui com informações relevantes e complementares de produção de forragem e comportamento da planta forrageira em ecossistemas de pastagem, através de informações sobre a estabilidade da população de plantas contribuindo para redução do risco de degradação dos pastos.The objective of this review is to present the concepts and current research on the main methods for evaluation of the sward in pastures planted with tropical forage plants environments. In the evaluation of pastures, the study of variables that directly affect the productive performance of the animals, has been prioritized, and thus, there are some determining factors on the performance of the production system, all of which seek greater consumption of forage and better performance of the animals. One of the determining factors to estimate a pasture carrying capacity, is getting the forage mass, and the most accurate method to estimate forage mass of a pasture is the harvest of all this material in the area to be evaluated. However, this has operational limitations to run on large areas, which meant that indirect methods based on geographic modeling and information technologies were widely studied. In addition to the production characteristics, morphogenetic and structural characteristics may interfere directly on the efficiency of the system, so that characterize the grassland ecosystem, and can predict important information such as the life of a pasture and consumption of animals. Thus, the importance of methods to evaluate pastures contribute relevant information and additional fodder production and behavior of grasses in pasture ecosystems, through information on the stability of the plant population contributing to reducing the risk of degradation of pastures.En esta revisión se ha propuesto presentar los conceptos e investigaciones actuales sobre los principales métodos para la evaluación del dosel forrajero en ambientes de pastos cultivados con plantas forrajeras tropicales. En la evaluación de pastos, el estudio sobre variables que afectan directamente al desempeño productivo de los animales, ha sido priorizado, y de este modo, existen algunos factores determinantes sobre el desempeño del sistema de producción, siendo que todos buscan un mayor consumo del forraje y mejor desempeño de los animales. Uno de los factores determinantes para la estimación de la capacidad de soporte de un pastoreo, es la obtención de la masa de forraje, siendo que el método más preciso para estimar la masa de forraje de un pastoreo consiste en la recolección de todo el material presente en el área a ser evaluada. Sin embargo, éste tiene limitaciones operativas para su ejecución en grandes áreas, lo que ha provocado ampliamente el estudio de métodos indirectos basados en las tecnologías de la información geográfica y el modelado. Además de las características de producción, las características morfogénicas y estructurales pueden interferir directamente en la eficiencia del sistema, de modo que, caracterizan el ecosistema pastoreo, y pueden predecir informaciones importantes como la vida útil de un pastoreo y consumo de los animales. De este modo, la importancia de las metodologías para la evaluación de pastos contribuye con informaciones relevantes y complementarias de producción de forraje y comportamiento de la planta forrajera en ecosistemas de pastoreo, a través de informaciones sobre la estabilidad de la población de plantas contribuyendo a reducir el riesgo de degradación de los pastos

Unconventional Magnetization Generated from Electron Beam and Femtosecond Irradiation on α-Ag2WO4: A Quantum Chemical Investigation

Novel magnetic metals and metal oxides that use both the spin and charge of an electron offer exciting technological applications. Their discovery could boost research on functional nanoscale materials. Here, for the first time, we report the magnetization of α-Ag2WO4 under electron beam and femtosecond laser irradiation. The formation and growth of silver oxides (AgO, Ag2O, and Ag3O4) and Ag nanofilaments can be observed on the surface of α-Ag2WO4 crystals. These features were also present in the composition of an extruded material and could open new avenues for surface magnetism studies. In order to understand these results, we used first-principles density functional theory calculations. This allowed us to investigate several potential scenarios for controlling magnetic properties. The effect of electron addition on the crystalline structures of α-Ag2WO4, Ag3O4, Ag2O, and AgO has been analyzed in detail. The creation of Ag and O vacancies on these compounds was also analyzed. Based on structural and electronic changes at the local coordination site of Ag, a mechanism was proposed. The mechanism illustrates the processes responsible for the formation and growth of metallic Ag and the magnetic response to electron beam irradiation

Phenotypic and Functional Signatures of Peripheral Blood and Spleen Compartments of Cynomolgus Macaques Infected With T. cruzi: Associations With Cardiac Histopathological Characteristics

We performed a detailed analysis of immunophenotypic features of circulating leukocytes and spleen cells from cynomolgus macaques that had been naturally infected with Trypanosoma cruzi, identifying their unique and shared characteristics in relation to cardiac histopathological lesion status. T. cruzi-infected macaques were categorized into three groups: asymptomatic [CCC(-)], with mild chronic chagasic cardiopathy [CCC(+)], or with moderate chronic chagasic cardiopathy [CCC(++)]. Our findings demonstrated significant differences in innate and adaptive immunity cells of the peripheral blood and spleen compartments, by comparison with non-infected controls. CCC(+) and CCC(++) hosts exhibited decreased frequencies of monocytes, NK and NKT-cell subsets in both compartments, and increased frequencies of activated CD8+ T-cells and GranA+/GranB+ cells. While a balanced cytokine profile (TNF/IL-10) was observed in peripheral blood of CCC(-) macaques, a predominant pro-inflammatory profile (increased levels of TNF and IFN/IL-10) was observed in both CCC(+) and CCC(++) subgroups. Our data demonstrated that cardiac histopathological features of T. cruzi-infected cynomolgus macaques are associated with perturbations of the immune system similarly to those observed in chagasic humans. These results provide further support for the validity of the cynomolgus macaque model for pre-clinical research on Chagas disease, and provide insights pertaining to the underlying immunological mechanisms involved in the progression of cardiac Chagas disease

Agricultura orgânica em áreas urbanas e periurbanas com base na agroecologia.

A agricultura orgânica com base na agroecologia é o mote tecnológico adequado à realidade dos agroecossistemas urbanos. Este artigo ressalta a necessidade de se desenvolver tecnologias e insumos específicos. A partir de experiências com agricultura urbana em diferentes países em desenvolvimento, evidencia-se a necessidade de se buscar capacidades locais e apoio do poder público, especialmente nas iniciativas da sociedade organizada e mobilizada para a produção agrícola urbana

Reticulocyte count: comparison among methods

Introduction: The automated counting of reticulocytes has some advantages over the manual method routinely used in clinical laboratories. Technological innovations provide more statistically reliable results, while optimizing the time to perform this test. However, the cost for implementing the automated procedure in laboratory routines still constitutes a barrier to its use in small- and medium-size Brazilian laboratories. Objective: This study evaluated the performance of a new laboratory protocol for reticulocyte counting by flow cytometry using acridine orange (FC/AO), compared with the manual method and with another automated one by flow cytometry using the commercial kit BD Retic-Count (FC/RC) Conclusion: The results showed that, besides being comparable to the manual method, still considered standard, the evaluated new protocol is economically more advantageous than the automated methods currently available, and its cost is comparable to that of the manual method for laboratories that already have appropriate equipment and infrastructure