Toxicity assessment of perovskite nanocomposites: In vivo study

Perovskite solar cells display potential as a renewable energy source because of their high-power conversion efficiency. However, there is limited understanding regarding the potential impact of perovskite on human health and the ecosystem. In this study, two sets of male Wistar albino rats received 35 injections of perovskite composite at a dosage of 0.372 mg/kg body weight. The animals underwent thorough examinations, encompassing morphometric, hematological, biochemical, histological, and behavioral analyses. Liver, kidney, and testis biopsies were processed and examined histologically. Additionally, two groups of mice (perovskite-treated and control mice, each with n = 10) underwent three behavioral tests: the Elevated Zero Maze test, Marble Burying test, and Light-Dark Box test. Perovskite-treated rats displayed a significant increase in levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglycerides, cholesterol, creatinine, blood urea nitrogen, white blood cells, and platelets. However, total bilirubin levels decreased, with no significant alteration in albumin values. Furthermore, exposure to perovskite composite resulted in a slight decrease in lactate dehydrogenase and red blood cell count. Histopathological examination revealed hepatic hydropic degeneration, Kupffer cells hypertrophy and hyperplasia, and renal hydropic degeneration, while testicular tissues remained unaffected. Moreover, behavioral changes were observed in perovskite-treated mice, including depression, anxiety, and compulsive burying activity. These findings suggest that exposure to perovskite can lead to significant hematological and biochemical changes, as well as hepatorenal histopathological alterations and behavioral changes. Additionally, chronic exposure to perovskite materials may induce structural and functional alterations in vital organs.

Selected Political Criminal Poisonings in the Years 1978-2020: Detection and Treatment

Criminal poisonings are among the least frequently detected crimes in the world. Lack of suspicion of this type of event by police officers and prosecutors, clinical symptoms imitating many somatic diseases and technical difficulties in diagnostics, as well as high research costs make the actual frequency of these events difficult to estimate. The substance used for criminal poisoning is often characterized by: lack of taste, color and smell, delayed action, easy availability and difficulty to detect. The aim of the study was to analyze selected cases of political poisoning that took place in the years 1978-2020, to describe the mechanisms of action of the substances used and to evaluate the diagnosis and treatment. The analyzed cases of criminal poisoning concerned: Georgi Markov (ricin), Khalid Maszal (fentanyl), Wiktor Yushchenko (TCDD dioxin), Jasir Arafat (polonium ²¹⁰Po isotope), Alexander Litvinenko (polonium ²¹⁰Po isotope), Kim Jong-Nam (VX), Sergei Skripal (Novichok) and Alexei Navalny (Novichok). Contemporary poisons, to a greater extent than in the past, are based on the use of synthetic substances from the group of organophosphorus compounds and radioactive substances. The possibility of taking appropriate and effective treatment in such cases is the result of many factors, including the possibility of quick and competent rescue intervention, quick and reliable detection of the toxic substance and the possibility of using an antidote.

Post-exposure therapy with recombinant human BuChE following percutaneous VX challenge in guinea-pigs

Poisoning by nerve agents via the percutaneous (p.c.) route is an issue because the slow absorption of agent could result in poisoning which outlasts the protection provided by conventional pharmacological therapy. The bioscavenger approach is based on the concept of binding nerve agent in the bloodstream, thus preventing nerve agent from reaching the target tissues and inhibiting acetylcholinesterase activity. One bioscavenger that has been extensively studied is human butyrylcholinesterase (huBuChE). Protexia® is a pegylated form of recombinant huBuChE. We used a guinea-pig model of p.c. nerve agent poisoning, using an implanted telemetry system to collect physiological data. Guinea-pigs were poisoned with the nerve agent VX (0.74 mg/kg) (∼2.5 × LD₅₀). Two hours following VX exposure, Protexia (72 mg/kg) or saline control was administered intramuscularly. All guinea-pigs treated with Protexia (n=8) survived, compared to no survivors in a saline-treated control group (n=8). Survival following VX and Protexia treatment was associated with minimal incapacitation and observable signs of poisoning, and the mitigation or prevention of the detrimental physiological changes (e.g. seizure, bradycardia and hypothermia) observed in control animals. The opportunity for post-exposure treatment may have utility in both civilian and military scenarios, and this is a promising indication for the use of a bioscavenger.

Gastrointestinal acetylcholinesterase activity following endotracheal microinstillation inhalation exposure to sarin in guinea pigs

The goal of this study was to assess acetylcholinesterase (AChE) inhibition at different regions of the gastrointestinal (GI) tract following inhalation exposure to nerve agent sarin. Seven major regions of the GI tract were removed from saline control animals (n=3) and 677.4 mg/m(3) sarin-exposed animals at 4h (n=4) and 24h (n=4) post-exposure. AChE activity was determined in blood and homogenized tissue supernatant by specific Ellman's assay using Iso-OMPA, a BChE inhibitor, and expressed as activity/optical density of hemoglobin for blood and activity/mg protein for tissues. Our data showed that the AChE activity was significantly decreased for groups both 4h and 24h post-sarin exposure. Among the seven chosen regions of the guinea pig GI tract, duodenum showed the highest AChE activity in control animals. The AChE activity was significantly decreased in the stomach (p=0.03), duodenum (p=0.029), jejunum (p=0.006), and ileum (p=0.006) 4h following sarin exposure. At 24h post-sarin exposure the AChE activity of duodenum (p=0.029) and ileum (p=0.006) was significantly inhibited. Esophagus showed no inhibition following sarin exposure at both 4h and 24h groups. These results suggest that the AChE activity is different in different regions of the GI tract and highest levels of AChE inhibition following sarin exposure were seen in regions exhibiting higher overall AChE activity and cholinergic function.

Efficacy and physiological effects of human butyrylcholinesterase as a post-exposure therapy against percutaneous poisoning by VX in the guinea-pig

The physiological effects of human plasma-derived butyrylcholinesterase (huBuChE) administration and its modulation of the effects of percutaneous VX challenge are poorly understood. Percutaneously administered nerve agents are more slowly absorbed than inhaled agents; consequently, signs of poisoning occur later, with a longer duration. Telemetry was used to monitor heart rate, EEG, temperature and activity in guinea-pigs. Treatment with huBuChE at 30 or 120 min following percutaneous VX challenge ( approximately 2.5 x LD(50)) provided 100% protection from lethality. When huBuChE administration was delayed until the onset of observable signs of poisoning only 1 out of 6 animals survived to the end of the experiment at 7 days. This study adds to the body of evidence demonstrating the efficacy of huBuChE in animals by describing the successful therapeutic use of a protein bioscavenger as a post-exposure treatment against dermal exposure to VX up to 2h post-exposure. This study simultaneously used telemetric methods to show that the efficacy of huBuChE is linked to the prevention of detrimental physiological changes observed in control VX-treated animals. Post-exposure therapy is a promising additional indication for the concept of use of this material, and one that has particular relevance in a civilian exposure scenario.

Protective effect of reversible cholinesterase inhibitors (tacrine, pyridostigmine) and eqbuche against VX poisoning and brain acetylcholinesterase inhibition in rats

The protective effect of the reversible cholinesterase inhibitors tacrine and pyridostigmine alone or in combination with different drugs against acetylcholinesterase inhibition in the pontomedullar area and cerebellum of rats caused by VX agent (O-ethyl S-2-diisopropylaminoethyl methyl phosphonothiolate) in vivo (2xLD50) was studied along with survival of animals pretreated with different combinations of the drugs used. The best prophylactic effect was observed in a combination of pyridostigmine with benactyzine, trihexyphenidyle and HI-6. Tacrine alone or in other combinations has had no better prophylactic effect in comparison with these combinations containing pyridostigmine. Equine butyrylcholinesterase, also protected against VX poisoning very effectively.