Impacts of chloramine-T treatment on antioxidant enzyme activities and genotoxicity in rainbow trout, Oncorhynchus mykiss (Walbaum)

Effects of Short-Term Exposure of Chloramine-T Solution on the Characteristics of Light-Cured and Chemical-Cured Adhesives

This study evaluated the effect of a 0.5% chloramine T solution on a chemical-cured universal adhesive by comparing the light-cured, one-step, self-etch adhesive for the bonding performance, mechanical properties, and resin-dentin interfacial characteristics. Caries-free human molars were randomly assigned into eight groups based on the bonding systems employed (Bond Force II, BF and Bondmer Lightless, BL), the immersion solutions used before bonding (0.5% chloramine T solution and distilled water), and the immersion durations (5 and 60 min). Microtensile bond strength (μTBS), nanoleakage evaluation, and nanoindentation tests were performed, and the surface morphology of the resin-dentin interface was examined using a focus ion beam/scanning ion microscopy system. Immersion in chloramine-T for 5 min significantly decreased the μTBS of Bondmer Lightless (from 22.62 to 12.87 MPa) compared with that in distilled water. Moreover, there was also a decreasing trend after immersing in chloramine-T for 60 min (from 19.11 to 13.93 MPa). Chloramine T was found to have no effect on the hardness, elastic modulus, or morphological characteristics of the ion-beam milled resin-dentin interfacial surfaces in the tested adhesives, suggesting that chloramine T might reduce the bond strength by interfering with the interaction and the sealing between the adhesive resin and dentin in the chemical-cured universal adhesive, albeit without affecting the mechanical properties.

Effects of Chloramine T on zebrafish embryos malformations associated with cardiotoxicity and neurotoxicity

Chloramine T, a sodium p-toluene sulfonchloramide, is known to possess a wide spectrum of biocidal activity and is employed as a disinfectant in fish farms to treat bacterial infections. Although Chloramine T may effectively combat pathogens, the sublethal and lethal effects and changes in acetylcholinesterase (AChE) activity remain poorly elucidated using Danio rerio (zebrafish) embryos. Zebrafish is considered a model organism for toxicant screening research and exhibits mammalian-like physiological responses when exposed to environmental pollutants. The aim of this study was to (1) determine LC₅₀ of Chloramine T after 96 hr exposure, (2) verify disinfectant effects on developmental morphology, and (3) evaluate the disinfectant effects on AChE activity in zebrafish embryos. Chloramine T exposure was performed using 16, 32, 64, 128, or 256 mg/L concentrations. The mortality LC₅₀ values were 143.05 ± 3.11 and 130.97 ± 7.4 mg/L at 24 and 96 hr, respectively. Data demonstrated delayed hatching, reduced heartbeats, cardiac edema, and equilibrium disruption of hatched larvae throughout embryonic development. In addition, Chloramine T inhibited AChE activity at 64 or 128 mg/L after 96 hr treatment, corroborating the sub-lethality results observed in zebrafish embryo development and demonstrating an equilibrium disruption in zebrafish larvae.

Highly Sensitive Detection of the Insecticide Azamethiphos by Tris(2,2'-bipyridine)ruthenium(II) Electrogenerated Chemiluminescence

Azamethiphos (AZA) is an insecticide and neurotoxic agent that causes the inhibition of acetylcholinesterase (AChE). AChE is a vital enzyme for neurotransmission because it metabolizes acetylcholine neurotransmitter at the synaptic cleft and terminates synaptic transmission. It is worth mentioning that organophosphates and carbamates inhibit AChE. These AChE inhibitors bind to the active site of the enzyme and inactivate it, leading to paralysis and death. Herein, for the first time, we develop a sensitive, low-cost, and rapid electrogenerated chemiluminescence (ECL) system for the detection of AZA. The designed ECL sensor was applied for the highly sensitive detection of AZA with a wide dynamic range (from 0.1 μM to 1000 μM) and low detection limit of 0.07 μM (S/N = 3). The practical utility of the sensor demonstrates high recoveries (96-102%) in real samples of lake water and wastewater.

Cumulative impact of anti-sea lice treatment (azamethiphos) on health status of Rainbow trout (Oncorhynchus mykiss, Walbaum 1792) in aquaculture

Despite its widespread use in aquaculture, the impact of chemical anti-sea lice treatment on salmonids following application in a commercial farm has not been previously reported. This work reports the cumulative effect of three consecutive anti-sea lice treatments using azamethiphos on the health status of aquaculture reared rainbow trout through the investigation of clinical chemistry, histopathology and proteome expression. The serum biomarkers showed decreasing trends in total protein, albumin and potassium concentrations and an average increase of total bilirubin and phosphate concentration towards the end of the treatment period. Principal component analysis clearly distinguished correlated pairs of biomarkers and also demonstrates a shift from acute to chronic effects as treatment progresses. Proteomic analysis confirmed alterations of proteins involved in clot formation, immune reaction and free heme binding. Tissue damage after the series of delousing treatments, exhibited increased deposits of hemosiderin. Results from this study suggest an impact of azamethiphos on trout health through intravascular haemolysis and consequently from pathophysiologic process of haemoglobin metabolism and its products, causing chronic kidney injury from iron deposits. This is the first report to demonstrate in fish the impact of active iron accumulation in different organs from physiological processes that can seriously impair normal function.