Effects of manganese, 2,5-xylidine, veratryl alcohol and tween 80 on the production of ligninolytic enzymes by Ceriporiopsis subvermispora

The effects of adding manganese, 2,5-xylidine, veratryl alcohol and Tween 80 in a culture medium used for the production of ligninolytic enzymes by polyurethane foam-immobilized Ceriporiopsis subvermispora were studied. While 11 ppm Mn2+ promoted the highest maximum activity of  manganese peroxidase (108.0 ± 43.3 U/L, in the 6th day of cultivation), the medium without manganese led to the highest maximum activity of laccase (15.5 ± 2.1 U/L, in the 12th day of cultivation). By supplementing the medium containing 11 ppm Mn2+ with 1.0 mM 2,5-xylidine, it was possible to improve the maximum activity of laccase to 21.5 ± 4.9 U/L. The supplementation of the medium containing 11 ppm Mn2+ with 1.0mM veratryl alcohol, in turn, led to an apparent second peak of MnP activity (110.0 ± 1.4 U/L, in the 24th day of cultivation; compared to 147.5 ± 60.1 U/L, in the 9th day of cultivation). When the medium containing 11 ppm Mn2+ and 1.0 mM 2,5-xylidine was supplemented with 0.05% (v/v) Tween 80, the maximum activities of Lac and MnP reached 53.3 ± 17.7 U/L (21st day of cultivation) and 174.8 ± 1.4 U/L (9th day of cultivation),  respectively. During the cultivations, the exhaustion of glucose in the medium promoted nutritional stress, which, in turn, led to cell autolysis; reflected by an apparent reduction in the concentration of mycelium, and by an increase in the concentration of ammonium. The concentrations of extracellular proteins increased throughout the cultivations; such  concentrations, however, did not generally exhibit good correlations with the measured enzyme activities.Key words: Ceriporiopsis subvermispora, manganese, 2,5-xylidine, veratryl alcohol, Tween 80; manganese peroxidase, laccase

Investigating the molecular mechanisms of organophosphate and pyrethroid resistance in the fall armyworm Spodoptera frugiperda.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tThe fall armyworm Spodoptera frugiperda is an economically important pest of small grain crops that occurs in all maize growing regions of the Americas. The intensive use of chemical pesticides for its control has led to the selection of resistant populations, however, to date, the molecular mechanisms underlying resistance have not been characterised. In this study the mechanisms involved in the resistance of two S. frugiperda strains collected in Brazil to chlorpyrifos (OP strain) or lambda-cyhalothrin (PYR strain) were investigated using molecular and genomic approaches. To examine the possible role of target-site insensitivity the genes encoding the organophosphate (acetylcholinesterase, AChE) and pyrethroid (voltage-gated sodium channel, VGSC) target-site proteins were PCR amplified. Sequencing of the S. frugiperda ace-1 gene identified several nucleotide changes in the OP strain when compared to a susceptible reference strain (SUS). These result in three amino acid substitutions, A201S, G227A and F290V, that have all been shown previously to confer organophosphate resistance in several other insect species. Sequencing of the gene encoding the VGSC in the PYR strain, identified mutations that result in three amino acid substitutions, T929I, L932F and L1014F, all of which have been shown previously to confer knockdown/super knockdown-type resistance in several arthropod species. To investigate the possible role of metabolic detoxification in the resistant phenotype of the OP and PYR stains all EST sequences available for S. frugiperda were used to design a gene-expression microarray. This was then used to compare gene expression in the resistant strains with the susceptible reference strain. Members of several gene families, previously implicated in metabolic resistance in other insects were found to be overexpressed in the resistant strains including glutathione S-transferases, cytochrome P450s and carboxylesterases. Taken together these results provide evidence that both target-site and metabolic mechanisms underlie the resistance of S. frugiperda to pyrethroids and organophosphates.BBSRCNational Council for Scientific and Technological Development of Brazi

Ammonia emissions in tunnel-ventilated broiler houses

Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems.26527

Glucose uptake and lipid metabolism are impaired in epicardial adipose tissue from heart failure patients with or without diabetes

Type 2 diabetes mellitus is a complex metabolic disease, and cardiovascular disease is a leading complication of diabetes. Epicardial adipose tissue surrounding the heart displays biochemical, thermogenic, and cardioprotective properties. However, the metabolic cross-talk between epicardial fat and the myocardium is largely unknown. This study sought to understand epicardial adipose tissue metabolism from heart failure patients with or without diabetes. We aimed to unravel possible differences in glucose and lipid metabolism between human epicardial and subcutaneous adipocytes and elucidate the potential underlying mechanisms involved in heart failure. Insulin-stimulated [(14)C]glucose uptake and isoproterenol-stimulated lipolysis were measured in isolated epicardial and subcutaneous adipocytes. The expression of genes involved in glucose and lipid metabolism was analyzed by reverse transcription-polymerase chain reaction in adipocytes. In addition, epicardial and subcutaneous fatty acid composition was analyzed by high-resolution proton nuclear magnetic resonance spectroscopy. The difference between basal and insulin conditions in glucose uptake was significantly decreased (P= 0.006) in epicardial compared with subcutaneous adipocytes. Moreover, a significant (P< 0.001) decrease in the isoproterenol-stimulated lipolysis was also observed when the two fat depots were compared, and it was strongly correlated with lipolysis, lipid storage, and inflammation-related gene expression. Moreover, the fatty acid composition of these tissues was significantly altered by diabetes. These results emphasize potential metabolic differences between both fat depots in the presence of heart failure and highlight epicardial fat as a possible therapeutic target in situ in the cardiac microenvironment.info:eu-repo/semantics/publishedVersio

Hostility and Physiological Responses to Acute Stress in People With Type 2 Diabetes

Objective: Hostility is associated with cardiovascular mortality and morbidity, and one of the mechanisms may involve heightened reactivity to mental stress. However, little research has been conducted in populations at high risk for cardiovascular disease. The aim of the present study was to assess the relationship between hostility and acute stress responsivity in individuals with Type 2 diabetes. Methods: A total of 140 individuals (median age [standard deviation] 63.71 [7.00] years) with Type 2 diabetes took part in laboratory-based experimental stress testing. Systolic blood pressure, diastolic blood pressure, heart rate, plasma interleukin-6 (IL-6), and salivary cortisol were assessed at baseline, during two stress tasks, and 45 and 75 minutes later. Cynical hostility was assessed using the Cook Medley Cynical Hostility Scale. Results: Participants with greater hostility scores had heightened increases in IL-6 induced by the acute stress tasks (B = 0.082, p = .002), independent of age, sex, body mass index, smoking, household income, time of testing, medication, and baseline IL-6. Hostility was inversely associated with cortisol output poststress (B = −0.017, p = .002), independent of covariates. No associations between hostility and blood pressure or heart rate responses were observed. Conclusions: Hostile individuals with Type 2 diabetes may be susceptible to stress-induced increases in inflammation. Further research is needed to understand if such changes increase the risk of cardiovascular disease in this population