Is cardiac tissue more susceptible than lung to oxidative effects induced by chronic nasotropic instillation of residual oil fly ash (ROFA)?

The current study aimed to determine the role of oxidants in cardiac and pulmonary toxicities induced by chronic exposure to ROFA. Eighty Wistar rats were divided into four groups: G1 (10 mu L Saline), G2 (ROFA 50 mu g/10 mu L), G3 (ROFA 250 mu g/10 mu L) and G4 (ROFA 500 mu g/10 mu L). Rats received ROFA by nasotropic instillation for 90 days. After that, they were euthanized and bronchoalveolar lavage (BAL) was performed for total count of leukocytes, protein and lactate dehydrogenase (LDH) determinations. Lungs and heart were removed to measure lipid peroxidation (MDA), catalase (CAT) and superoxide dismutase (SOD) activity. BAL presented an increase in leukocytes count in G4 in comparison to the Saline group (p = 0.019). In lung, MDA level was not modified by ROFA, while CAT was higher in G4 when compared to all other groups (p = 0.013). In heart, G4 presented an increase in MDA (p = 0.016) and CAT (p = 0.027) levels in comparison to G1. The present study demonstrated cardiopulmonary oxidative changes after a chronic ROFA exposure. More specifically, the heart tissue seems to be more susceptible to oxidative effects of long-term exposure to ROFA than the lung.

Investigating the causal role of rightOFA in holistic detection of Mooney faces and objects: an fMRI-guided TMS study

Background The right occipital face area (rOFA) is known to be involved in face discrimination based on local featural information. Whether this region is involved in global, holistic stimulus processing is not known. Objective We used fMRI-guided transcranial magnetic stimulation (TMS) to investigate whether rOFA is causally implicated in stimulus detection based on holistic processing, by the use of Mooney stimuli. Methods Two studies were carried out: In Experiment 1, participants performed a detection task involving Mooney faces and Mooney objects; Mooney stimuli lack distinguishable local features and can be detected solely via holistic processing (i.e. at a global level) with top-down guidance from previously stored representations. Experiment 2 required participants to detect shapes which are recognized via bottom-up integration of local (collinear) Gabor elements and was performed to control for specificity of rightOFA's implication in holistic detection. Results In Experiment 1, TMS over rOFA and rLO impaired detection of all stimulus categories, with no category-specific effect. In Experiment 2, shape detection was impaired when TMS was applied over rLO but not over rOFA. Conclusions Our results demonstrate that rOFA is causally implicated in the type of top-down holistic detection required by Mooney stimuli and that such role is not face-selective. In contrast, rOFA does not appear to play a causal role in in detection of shapes based on bottom-up integration of local components, demonstrating that its involvement in processing non-face stimuli is specific for holistic processing.

Avaliação de mutagenicidade, citotoxicidade e expressão de proteínas relacionadas a apoptose, Bak, BCL-2 e P53 fosforilado, em células tratadas com fuligem e particulado total de queima de cana-de-açúcar

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR