Universidade Estadual de Londrina

About: Universidade Estadual de Londrina is a education organization based out in Londrina, Brazil. It is known for research contribution in the topics: Population & Toxoplasma gondii. The organization has 13052 authors who have published 19291 publications receiving 212123 citations.

Lactic acid bacteria in the inhibition of Fusarium graminearum and deoxynivalenol detoxification.

Abstract: Aims: Considering the agronomic and industrial damage that is caused by the fungus Fusarium graminearum, as well as the serious health risks it poses to humans and animals exposed to F. graminearum-produced mycotoxin deoxynivalenol (DON), this study evaluated the ability of different lactic acid bacteria (LAB) strains to inhibit fungal development and remove DON in vitro. Methods and Results: The antagonistic effects of strains and commercial cultures of LAB were evaluated against F. graminearum IAPAR 2218 by the agar diffusion method. Additionally, the influence of the culture media, pH and the presence of lactic and acetic acid on these effects was tested. The capacity to remove DON by viable cells and heat-inactivated cells was analysed in liquid media and quantified by high performance liquid chromatography (HPLC). All isolated strains and commercial cultures inhibited the fungus and removed DON. The pH and culture media concentration did not influence these abilities, but heat inactivation had a strong effect on the ability of bacteria to remove mycotoxin. Conclusions: The isolated bacteria are able to inhibit F. graminearum growth and remove DON in vitro. Significance and Impact of the Study: This study suggests potential application of the isolated LAB strains in the inhibition of F. graminearum IAPAR 2218 and DON removal in vitro.

Chronic inflammation in skeletal muscle impairs satellite cells function during regeneration: can physical exercise restore the satellite cell niche?

Abstract: Chronic inflammation impairs skeletal muscle regeneration. Although many cells are involved in chronic inflammation, macrophages seem to play an important role in impaired muscle regeneration since these cells are associated with skeletal muscle stem cell (namely, satellite cells) activation and fibro-adipogenic progenitor cell (FAP) survival. Specifically, an imbalance of M1 and M2 macrophages seems to lead to impaired satellite cell activation, and these are the main cells that function during skeletal muscle regeneration, after muscle damage. Additionally, this imbalance leads to the accumulation of FAPs in skeletal muscle, with aberrant production of pro-fibrotic factors (e.g., extracellular matrix components), impairing the niche for proper satellite cell activation and differentiation. Treatments aiming to block the inflammatory pro-fibrotic response are partially effective due to their side effects. Therefore, strategies reverting chronic inflammation into a pro-regenerative pattern are required. In this review, we first describe skeletal muscle resident macrophage ontogeny and homeostasis, and explain how macrophages are replenished after muscle injury. We next discuss the potential role of chronic physical activity and exercise in restoring the M1 and M2 macrophage balance and consequently, the satellite cell niche to improve skeletal muscle regeneration after injury.

Thermally reduced graphene oxide: synthesis, studies and characterization

Abstract: The main purpose of this study is to synthesize reduced graphene oxide (rGO) using graphite (GR) as a starting material. This paper explains didactic step-by-step of the synthesis, the role of each reagent, showing pictures of the entire process and including a well-explained characterization study. The rGO was prepared using modified Hummer’s method, followed by thermal reduction. The materials were characterized from the starting material (GR), through the intermediate material (GO) and finally the material of interest (rGO). Various techniques and procedures were used to characterize the materials such as X-ray diffraction, infrared and Raman spectroscopy, scanning electron microscopy, electrochemical characterization and dispersion analysis. Morphological and structural characterization of the obtained materials suggests that the synthesis and reduction to obtain rGO were effective. The obtained materials were electrochemically evaluated using ferri/ferrocyanide redox probe. The association of chemical oxidation of GR with KMnO4 in the presence of H2SO4 with further thermal reduction makes possible to produce rGO in large scale and with quality as noticed by outstanding electrochemical behavior toward the redox couple [Fe(CN)6]3−/[Fe(CN)6]4− probe.

Acute effects of nitrite on ion regulation in two neotropical fish species

Abstract: To broaden the understanding of physiological responses of tropical fish to environmental stressors, the effects of nitrite on haematological parameters and plasma and red blood cell ion regulation were studied in two neotropical fish species, Astyanax altiparanae and Prochilodus lineatus. Both fish species were exposed to NaNO2 (30 mg l(-1)) over a 96-h period and blood samples were taken for ion and haematological analyses. The results revealed that nitrite leads to a decrease in P. lineatus blood haematocrit and haemoglobin content and an increase in blood methaemoglobin. A. altiparanae did not exhibit any significant difference in these haematological parameters. During the exposure to NO2- both fish species had significantly reduced plasma Na+ concentration and red blood cell (RBC) K+ concentration, but only P. lineatus showed an increase in extracellular K+ concentration. When RBC volume was analyzed in vitro, after 2 min of exposure to NaNO2, a 36% shrinkage was observed in P. lineatus cells, while only a 10% shrinkage was observed in A. altiparanae cells. These results suggest that for P. lineatus, nitrite entrance into the cell leads to methaemoglobin formation and K+ efflux, causing red cell shrinkage and increased plasma K+. However, A. altiparanae proved to be a species more resistant to nitrite, exhibiting fewer responses to this compound.