39 research outputs found

    Hypothalamic Microglial Activation in Obesity: A Mini-Review

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    Emerging data demonstrate that microglia activation plays a pivotal role in the development of hypothalamic inflammation in obesity. Early after the introduction of a high-fat diet, hypothalamic microglia undergo morphological, and functional changes in response to excessive dietary saturated fats. Initially the resident microglia are affected; however, as diet-induced obesity persists, bone marrow-derived myeloid cells gradually replace resident microglia. Genetic and pharmacological approaches aimed at dampening the inflammatory activity in the hypothalamus of experimental models of obesity have proven beneficial to correct the obese phenotype and improve metabolic abnormalities commonly associated with obesity. These approaches provide an experimental proof-of-concept that hypothalamic inflammation is central to the pathophysiology of obesity; understanding the details of the roles played by microglia in this process may help the development of preventive and therapeutic advances in the field. In this review, we discuss the potential mechanisms underlying hypothalamic microglial activation in high-fat induced obesity

    Behavioral alterations and Fos protein immunoreactivity in brain regions of bile duct-ligated cirrhotic rats

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    Hepatic encephalopathy (HE) encompasses a variety of neuropsychiatric symptoms, including anxiety and psychomotor dysfunction. Although HE is a frequent complication of liver cirrhosis, the neurobiological substrates responsible for its clinical manifestations are largely unclear. In the present study, male Wistar rats were bile duct-ligated (BDL), a procedure which induces liver cirrhosis, and on the 21st day after surgery tested in the elevated plus-maze (EPM) and in an open field for anxiety and locomotor activity measurements. Analysis of Fos protein immunoreactivity (Fos-ir) was used to better understand the neurobiological alterations present in BDL animals. Plasma levels of ammonia were quantified and histopathological analysis of the livers was performed. BDL rats showed a significant decrease in the percentage of entries and time spent in the open arms of the EPM, an anxiogenic effect. These animals also presented significant decreases in Fos-ir in the lateral septal nucleus and medial amygdalar nucleus. Their ammonia plasma levels were significantly higher when compared to the sham group and the diagnosis of cirrhosis was confirmed by histopathological analysis. These results indicate that the BDL model induces anxiogenic results, possibly related to changes in the activation of anxiety-mediating circuitries and to increases in ammonia plasma levels.A Encefalopatia hepática (HE) engloba uma variedade de sintomas neuropsiquiátricos, incluindo ansiedade e disfunção psicomotora. Embora seja uma complicação frequente da cirrose hepática, os substratos neurobiológicos responsáveis por suas manifestações clínicas são em grande parte desconhecidos. No presente estudo, ratos Wistar machos foram submetidos ao procedimento cirúrgico de ligação e secção do ducto biliar (BDL; bile-duct ligation), para indução da cirrose hepática e, no 21º dia após a cirurgia, submetidos aos testes comportamentais no labirinto em cruz elevado (LCE) e campo aberto para avaliação da ansiedade e atividade locomotora. A análise da imunorreatividade à proteína Fos (Fos-ir) foi utilizada para melhor compreender as alterações neurobiológicas presentes nos animais do grupo BDL. Foi realizada a quantificação da concentração de amônia plasmática e análise histopatológica dos fígados. Os ratos do grupo BDL mostraram diminuição significativa na porcentagem de entradas e tempo gasto nos braços abertos do LCE, caracterizando efeito ansiogênico. Estes animais também apresentaram redução significativa na Fos-ir no núcleo septal lateral e núcleo medial da amígdala. A concentração plasmática de amônia foi significativamente mais elevada que a do grupo sham e o diagnóstico de cirrose foi confirmado por análise histopatológica. Estes resultados indicam que o modelo de HE induzido por BDL induz efeito ansiogênico possivelmente relacionado à ativação de circuitos mediadores da ansiedade e à hiperamonemia.Universidade Federal de São Paulo (UNIFESP) Departamento de BiociênciasUniversidade de São Paulo Instituto de Ciências Biomédicas Departamento de AnatomiaUNIFESP, Depto. de BiociênciasSciEL

    Characterization of the genetic diversity of Mycobacterium tuberculosis in São Paulo city, Brazil

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    <p>Abstract</p> <p>Background</p> <p>Tuberculosis is a major health problem in São Paulo, Brazil, which is the most populous and one of the most cosmopolitan cities in South America. To characterize the genetic diversity of <it>Mycobacterium tuberculosis </it>in the population of this city, the genotyping techniques of spoligotyping and MIRU were applied to 93 isolates collected in two consecutive years from 93 different tuberculosis patients residing in São Paulo city and attending the Clemente Ferreira Institute (the reference clinic for the treatment of tuberculosis).</p> <p>Findings</p> <p>Spoligotyping generated 53 different spoligotype patterns. Fifty-one isolates (54.8%) were grouped into 13 spoligotyping clusters. Seventy- two strains (77.4%) showed spoligotypes described in the international databases (SpolDB4, SITVIT), and 21 (22.6%) showed unidentified patterns. The most frequent spoligotype families were Latin American Mediterranean (LAM) (26 isolates), followed by the T family (24 isolates) and Haarlem (H) (11 isolates), which together accounted for 65.4% of all the isolates. These three families represent the major genotypes found in Africa, Central America, South America and Europe. Six Spoligo-International-types (designated SITs by the database) comprised 51.8% (37/72) of all the identified spoligotypes (SIT53, SIT50, SIT42, SIT60, SIT17 and SIT1). Other SITs found in this study indicated the great genetic diversity of <it>M. tuberculosis</it>, reflecting the remarkable ethnic diversity of São Paulo city inhabitants. The MIRU technique was more discriminatory and did not identify any genetic clusters with 100% similarity among the 93 isolates. The allelic analysis showed that MIRU loci 26, 40, 23 and 10 were the most discriminatory. When MIRU and spoligotyping techniques were combined, all isolates grouped in the 13 spoligotyping clusters were separated.</p> <p>Conclusions</p> <p>Our data indicated the genomic stability of over 50% of spoligotypes identified in São Paulo and the great genetic diversity of <it>M. tuberculosis </it>isolates in the remaining SITs, reflecting the large ethnic mix of the São Paulo city inhabitants. The results also indicated that in this city, <it>M. tuberculosis </it>isolates acquired drug resistance independently of genotype and that resistance was more dependent on the selective pressure of treatment failure and the environmental circumstances of patients.</p

    OBSERVATORIO TERRITORIAL Y AMBIENTAL ALENTEJO, EXTREMADURA, CENTRO (OTALEX C): DE GIS A IDE.

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    In the scope of the Spain-Portugal INTERREG projects and FEDER funded POCTEP program, OTALEX C (Territorial and Environmental Monitoring Alentejo Extremadura Center) project aims at studying of various territorial, socioeconomic and environmental indicators. It is the fundamental objective of this project, to develop a geo-portal accessible via internet, for anyone, so that the information will be useful in making decisions related to land use and therefore sustainable development of the environment. Under this general framework over the past fifteen years, we have developed different projects that have set the standardization of data between Portugal and Spain, also was designed GIS systems, and developed regional models and indicator systems, culminating in the current Spatial Data Infrastructure SDI-OTALEX C

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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