A mixture of pesticides at environmental concentrations induces oxidative stress and cholinergic effects in the neotropical fish Rhamdia quelen

The insecticides imidacloprid (IMI), a neonicotinoid, and propoxur (PRO), an N-methylcarbamate compound, are pesticides widely used throughout the world. Although they are not used together to combat pests, both are often found in freshwater near agricultural areas. Thereby, the goal of this study was to evaluate the additive effects of IMI and PRO mixtures at environmental concentrations in relation to isolated compounds on Rhamdia quelen, a neotropical fish. The fish was exposed to IMI (0.11 µg/L), PRO (0.039 µg/L), or Mix (0.11 µg/L IMI plus 0.039 µg/L PRO) during 96 h. Glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (AChE) activities were determined. To verify oxidative damage thiobarbituric acid reactive substances (TBARS), protein carbonyl (PC), reactive oxygen species contents (ROS), antioxidant capacity against peroxides (ACAP) were determined in gills, liver, brain and muscle. The results shows that a mixture of these pesticides at environmental concentrations inhibited acetylcholinesterase activity in the brain and induced oxidative damage in all analyzed tissues. These results reinforce the hypothesis that mixture of contaminants present in environment could induce additive or synergistic effects on fish species.

     

The Importance of Structure and Connection for People Living With Schizophrenia: A 33-Year Outpatient Group Experience

This paper evaluates an outpatient group for persons living with schizophrenia. Qualitative changes and psychiatric admissions among group members were reviewed to measure recovery. Thirty-two members have attended sessions for up to 28 years. Meaningful interactions (e.g., supportive comments) have increased and hospitalizations have decreased. The support of the therapists and the other group members has allowed for personal recovery and developing and maintaining social connections. Prior to starting the group, 67% of members had >?1 hospitalization and 26% had none. During the group, 63% of members had no hospitalizations. Vignettes of change, peer support, fewer hospital admissions, and signs of recovery in the face of crises suggest that members benefit greatly from this outpatient group.