Defective defence in Daphnia daughters: silver nanoparticles inhibit anti-predator defence in offspring but not in maternal Daphnia magna.

One major environmental problem of our time are emerging contaminants in the aquatic environment. While nanoparticles exhibit attractive features such as antimicrobial properties in the case of silver nanoparticles (AgNPs), earlier studies suggest that NPs are not completely filtered out at wastewater treatment plants and may therefore be continuously introduced into the aquatic environment. Although adverse effects of AgNPs on aquatic organisms have been extensively studied, there is still a lack of knowledge on how this chemical stressor interacts with natural cues on the maternal and subsequent generation of aquatic organisms. We tested whether AgNPs (NM-300K, 14.9 ± 2.4 nm, concentration range: 2.5 µg/L - 20 µg/L) affect the kairomone-induced adaptive anti-predator defence mechanism in maternal Daphnia and their offspring. While maternal Daphnia developed typical anti-predator defence mechanisms when exposed to kairomones and AgNPs, their offspring could not develop such adaptive defensive traits. The lack of this defence mechanism in offspring could have dramatic negative consequences (e.g. reduced Daphnia population) for the entire complex food web in the aquatic ecosystem. For a realistic risk assessment, it is extremely important to test combinations of chemical stressors because aquatic organisms are exposed to several natural and artificial chemical stressors at the same time.

Lithium rechallenge after renal transplant.

Mrs B is a 65-year-old, married, white woman with long-standing history of bipolar disorder type I who achieved mood stability with chronic lithium treatment. She developed end-stage renal disease, which was suspected to be the result of chronic lithium exposure in the context of medical comorbidity, and subsequently required renal transplantation. Following transplantation and discontinuation of lithium, Mrs B was unable to achieve mood stability with multiple medication trials and required more than 40 medical and psychiatric hospitalizations with eventual transition to skilled nursing care. After much discussion among the psychiatric treatment team, the patient, and her husband, primary care provider, nephrologist, and renal transplant surgeon, the decision was made to restart the patient on lithium given her previous treatment success. The purpose of this case report is to discuss the use of lithium following renal transplantation. In this case, a multidisciplinary approach was used to assist the patient in carefully weighing the risks and benefits of her treatment decisions. The consensus of the patient, her husband, and her providers was that the benefit of mood stabilization outweighed the potential risks of renal toxicity. Although treatment with lithium after renal transplant is not a first-line treatment option, this case illustrates that lithium could be considered in certain cases.