Increased Oxidative Stress and Imbalance in Antioxidant Enzymes in the Brains of Alloxan-Induced Diabetic Rats

Diabetes Mellitus (DM) is associated with pathological changes in the central nervous system (SNC) as well as alterations in oxidative stress. Thus, the main objective of this study was to evaluate the effects of the animal model of diabetes induced by alloxan on memory and oxidative stress. Diabetes was induced in Wistar rats by using a single injection of alloxan (150 mg/kg), and fifteen days after induction, the rats memory was evaluated through the use of the object recognition task. The oxidative stress parameters and the activity of antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT) were measured in the rat brain. The results showed that diabetic rats did not have alterations in their recognition memory. However, the results did show that diabetic rats had increases in the levels of superoxide in the prefrontal cortex, and in thiobarbituric acid reactive species (TBARS) production in the prefrontal cortex and in the amygdala in submitochondrial particles. Also, there was an increase in protein oxidation in the hippocampus and striatum, and in TBARS oxidation in the striatum and amygdala. The SOD activity was decreased in diabetic rats in the striatum and amygdala. However, the CAT activity was increased in the hippocampus taken from diabetic rats. In conclusion, our findings illustrate that the animal model of diabetes induced by alloxan did not cause alterations in the animals' recognition memory, but it produced oxidants and an imbalance between SOD and CAT activities, which could contribute to the pathophysiology of diabetes

Chirally symmetric quark description of low energy \pi-\pi scattering

Weinberg's theorem for \pi-\pi scattering, including the Adler zero at threshold in the chiral limit, is analytically proved for microscopic quark models that preserve chiral symmetry. Implementing Ward-Takahashi identities, the isospin 0 and 2 scattering lengths are derived in exact agreement with Weinberg's low energy results. Our proof applies to alternative quark formulations including the Hamiltonian and Euclidean space Dyson-Schwinger approaches. Finally, the threshold \pi-\pi scattering amplitudes are calculated using the Dyson-Schwinger equations in the rainbow-ladder truncation, confirming the formal derivation.Comment: 10 pages, 7 figures, Revtex

Desempenho de luta e sobrevivência entre espécies de abelhas sem ferrão e abelhas africanizadas em confinamento.

Este estudo avaliou o desempenho de luta e a sobrevivência de três espécies de abelhas sem ferrão confinadas com abelhas africanizadas (Apis mellifera)

Coleta de recursos e atividade externa de abelhas campeiras de Scaptotrigona sp. e Plebeia aff. flavocincta (Hymenoptera, Apidae, Meliponini) no Semiárido da Caatinga.

Este trabalho avaliou a qualidade de recursos e a atividade externa de abelhas campeiras de Scaptotrigona sp. e Plebeia aff. flavocincta na Caatinga

Understanding Brazil’s catastrophic fires : causes, consequences and policy needed to prevent future tragedies

Brazil has experienced unprecedented wildfires in the last decade. Images ofimmense burnt areas or dead animals that failed to escape the 2020 wildfires have shocked the world. To prevent or minimize further similardisasters wemustunderstandthe factors thathave ledto these catastrophic events. The causes and consequences of wildfires entail complex interactions between the biophysical and sociocultural spheres, and suitable management decisions require a sound scientific base. We present the recent panorama of increasing fire outbreaks in the Brazilian biomes, and discuss the causes that have contributed to such fires, their impacts on the environment and overall consequences for human well-being, based on reviewing the extensive specialist literature, on authors’ expert knowledge and information provided by environmental managers, researchers and politicians during a workshop organized to debate the wildfire issue in Brazil. Our up-to-date review is aimed at the academic public, environmental managers and decision- and policy-makers. First, we present evidence on the contrasting effects of fire on different ecosystems. Second, we outline the historic perceptions and policies related to fire use and management in Brazil since its colonization to the present date. Third, we propose means to advance fire prevention and develop successful management strategies. Finally, we answer frequently asked questions to clarify and/or demystify some fire-related issues not always properly addressed in the media

Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047). A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009), whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094). In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010). However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut-microbiota interactions and in mediating fibrosis. Understanding the effects of several drugs associated with multidrug resistance 1 gene variants may aid in the selection of customized therapeutic regimens

Úlcera de perna: um estudo de casos em Juiz de Fora-MG (Brasil) e região

BACKGROUND: Leg ulcers are characterized as tissue loss in the lower extremities, generally caused by vascular dysfunction.OBJECTIVES: Verify the clinical and epidemiological profiles of the population sample with leg ulcers treated at the health centers of Juiz deFora (Brazil).MATERIAL ANDMETHODS: 124 leg-wound patients were evaluated between January 1999 and August 2001 and submitted to aclinical protocol.RESULTS: The mean age was 64 years, with females in the majority (65.3%). The mean family composition was 3.7 persons, and family inco-me was around US$200.00 (86.8OBJETIVOS: Caracterizar clínica e epidemiologicamente a amostra populacional com UP atendida nos centros de saúde de Juiz de Fora. PACIENTES E MÉTODOS: Submetidos ao protocolo clínico 124 pacientes com UP, de Juiz de Fora e região de janeiro/1999 a agosto/2001. RESULTADOS: A média de idade foi 64 anos, 65,3$540,00 (86,8%). Associavam-se às úlceras insuficiência venosa (90,3%), hipertensão arterial sistêmica (54%), obesidade (20,2%) e diabetes mellitus (16,1%). A associação insuficiência venosa e hipertensão arterial foi freqüente (43,7%) e significante (p5cm) em cerca de 90% da amostra, com médias de 8,7cm e 9,6cm para os eixos vertical e horizontal, respectivamente. Estavam acompanhadas de hipercromia (92,7%), lipodermatoesclerose (68,5%) e varicosidades (66,9%), com duração média de 94,2 meses, e 50% das úlceras eram recidivantes. CONCLUSÕES: Os dados sugerem que a úlcera de perna seja doença crônica significativa na população idosa e de baixa renda de Juiz de Fora e região

MazeLogic: Jogo Educacional para Ensino de Lógica de Programação

Resumo. A área de jogos educacionais tem crescido de forma exponencial noBrasil e no mundo, pois estes têm sido usados por muitos alunos como objetode aprendizagem. Os jogos apresentam o conhecimento de modo divertido elúdico e pode ser aplicado a qualquer área e assunto. Este trabalho destina-seao desenvolvimento de um jogo educacional para ensino-aprendizagem para adisciplina de Lógica de Programação.Palavras-chave: Ensino aprendizagem, Jogo Educacional, Lógica deProgramação