Bacterial laccases: some recent advances and applications

Laccases belong to the large family of multi-copper oxidases (MCOs) that couple the one-electron oxidation of substrates with the four-electron reduction of molecular oxygen to water. Because of their high relative non-specific oxidation capacity particularly on phenols and aromatic amines as well as the lack of requirement for expensive organic cofactors, they have found application in a large number of biotechnological fields. The vast majority of studies and applications were performed using fungal laccases, but bacterial laccases show interesting properties such as optimal temperature above 50 °C, optimal pH at the neutral to alkaline range, thermal and chemical stability and increased salt tolerance. Additionally, bacterial systems benefit from a wide range of molecular biology tools that facilitates their engineering and achievement of high yields of protein production and set-up of cost-effective bioprocesses. In this review we will provide up-to-date information on the distribution and putative physiological role of bacterial laccases and highlight their distinctive structural and biochemical properties, discuss the key role of copper in the biochemical properties, discuss thermostability determinants and, finally, review biotechnological applications with a focus on catalytic mechanisms on phenolics and aromatic amines.info:eu-repo/semantics/publishedVersio

Homens e violência conjugal: uma análise de estudos brasileiros Men and conjugal violence: an analysis of Brazilian studies

O estudo analisou qualitativamente 54 textos brasileiros sobre homens e violência conjugal, relacionados a atividades de pesquisa ou de intervenção. Primeiramente caracterizou-se o material quanto aos temas abordados, ao foco principal e ao tipo de texto. A seguir fizeram-se sínteses e análises das principais considerações dos textos a partir dos eixos temáticos encontrados: diferentes inteligibilidades da problemática, magnitude da violência conjugal, sentidos de homens relacionados à violência e intervenções e/ou políticas junto a homens agressores. A análise teve como parâmetro o ramo de discussões nacionais e internacionais que se esforça por ultrapassar a polêmica em torno da definição do problema como "violência de gênero" ou "violência conjugal", cunhando sobretudo o pressuposto de que existem diversos estilos de conjugalidade violenta. Concluiu-se que a maior unanimidade dos estudos é pensar a problemática como questão relacional de gênero. Defendeu-se, por fim, a ideia de que a escolha da melhor abordagem articuladora entre os polos da polêmica ainda demanda mais investigações, com metodologias qualitativas junto a atores de diferentes camadas e grupos sociais. Quanto às intervenções, propõem-se investimentos no maior número possível de alternativas, valorizando a singularidade dos casos.<br>This study consisted of a qualitative analysis of 54 Brazilian texts about men and conjugal violence related to research or intervention activities. Initially, the material was divided up according to the topics under scrutiny, the main focus and the type of text. Analysis and synthesis of the main considerations of the texts, based on the thematic points revealed, was then carried out. This included the different approaches to the problem, the magnitude of conjugal violence, the attitudes of men vis-à-vis violence and interventions and/or policies towards male aggressors. The parameter for the analysis was the national and international debate seeking to overcome the controversy surrounding the definition of the problem as "gender violence" or conjugal violence," essentially fostering the hypothesis of various types of violent conjugal relationships. It was concluded that the unanimous outcome of the study was to view the problem as a gender relationship issue. Lastly, it was argued that the choice of the best approach between the poles of the controversy requires further investigation using qualitative methodologies together with players from different classes and social backgrounds. With respect to further intervention, it was considered necessary to examine a broad gamut of alternatives emphasizing the singular nature of the cases

The role of obesity in the immune response during sepsis

BACKGROUND/OBJECTIVES: Sepsis is one of the most important causes of mortality in the developed world, where almost two-thirds of the population suffer from obesity. Therefore, the coexistence of both conditions has become frequent in clinical practice and a growing number of clinical studies attempts to examine the potential effect of obesity on sepsis with controversial results up to now. The present study investigates how obesity influences the immune response of septic patients, by assessing the number and activation state of adipose tissue macrophages, serum and adipose tissue tumor necrosis factor-alpha (TNF alpha) levels and plasma oxidative stress markers. SUBJECTS/METHODS: The study included 106 patients, divided into four groups (control n = 26, obesity n = 27, sepsis n = 27 and sepsis and obesity n = 26). The number of macrophages in subcutaneous and visceral adipose tissue (SAT and VAT) and their subtypes (M1 and M2) were defined with immunohistochemical staining techniques under light microscopy. TNF alpha mRNA levels were determined in SAT and VAT using real-time reverse transcription-PCR. Serum levels of TNF alpha were determined with sandwich enzyme-linked immunosorbent assay. Plasma oxidative stress was evaluated using selective biomarkers (thiobarbituric acid-reactive substances (TBARS), protein carbonyls and total antioxidant capacity (TAC)). RESULTS: Sepsis increased the total number of macrophages and their M2 subtype in (VAT), whereas obesity did not seem to affect the concentration of macrophages in fat. Obesity increased TNF alpha mRNA levels (P < 0.05) in VAT as well as the plasma TBARS (P < 0.001) and protein carbonyls (P < 0.001) in septic patients. The plasma TAC levels were decreased and the serum TNFa levels were increased in sepsis although they were not influenced by obesity. CONCLUSIONS: Obesity is associated with elevated TNF alpha adipose tissue production and increased oxidative stress biomarkers, promoting the proinflammatory response in septic patients