Exposure to humidifier disinfectants induces developmental effects and disrupts thyroid endocrine systems in zebrafish larvae
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
Authors: Kim, Hyojin; Ji, Kyunghee
Abstract
Humidifier disinfectants have been widely used in Korea to prevent the growth of microorganisms in humidifier water. However, their use has been banned since 2011 after epidemiological studies reported humidifier disinfectant induced lung injury. In the present study, the developmental effects of exposure to two humidifier disinfectants (Oxy (R) and Wiselect) and their main component, polyhexamethylene guanidine (PHMG)-phosphate, were investigated in zebrafish embryos/larvae for seven days. The effects on triiodothyronine (T3) and thyroxine (T4) hormones, reactive oxygen species (ROS) generation, antioxidant enzyme activities, and changes in expression of the genes related to the hypothalamus-pituitary-thyroid (HPT) axis and oxidative stress were also investigated. Zebrafish embryos exposed to the highest concentration (amounts recommended for use by the manufacturers) of all tested humidifier disinfectants showed an increase in embryo coagulation, leading to death without hatching. Exposure to Oxy (R) and Wiselect resulted in significantly decreased body length, increased ROS generation and antioxidant enzyme activities, decreased T4, and up-regulated genes related to the HPT axis (trh, tri beta, and tpo) and oxidative damage (sod2 and gpx1b). The humidifier disinfectants and PHMG-phosphate could induce oxidative stress and disrupt thyroid hormone systems in zebrafish, leading to developmental retardation when used at sub-lethal concentrations. Potential effects of long-term exposure to humidifier disinfectants and mixture effects of several major components deserve further investigation.
Thrombopoietin receptor agonists as second-line therapy in splenectomy-eligible persistent immune thrombocytopenia: a case series
BLOOD COAGULATION & FIBRINOLYSIS
Authors: Vianello, Fabrizio; D'Amore, Fabio; Lombardi, Anna M.; Caputo, Ilaria; Friziero, Alberto; Da Dalt, Gianfranco
Abstract
Thrombopoietin receptor agonists (TPO-RA) are currently approved to treat chronic immune thrombocytopenia (ITP) but there is increasing interest in considering these drugs earlier during the course of the disease. We present six patients with primary ITP resistant to corticosteroids and intravenous immunoglobulins, who received TPO-RA in the persistent phase and then underwent splenectomy in the chronic phase. Eltrombopag was administered as a second-line therapy in four patients, whereas two patients received romiplostim. Five out of six patients rapidly reached response or complete response (four and one, respectively) and steroid suspension. In one case, remission was obtained with steroid and TPO-RA. No significant side effects were reported. After splenectomy, complete response and response was reached in four and two patients, respectively. One relapse was recorded, rescued by steroid and eltrombopag. Postsplenectomy complication was registered in one patient (grade 4 intra-abdominal bleeding). TPO-RA could be a valuable choice in ITP patients in persistent phase candidates to splenectomy.