Proteomic profiling reveals mitochondrial toxicity of nanosilver and silver nitrate in the gill of common carp.

Mitochondria are recognized as an important target organelle for the toxicity of nanomaterials. Although the toxic effects of silver nanoparticles (AgNPs) on mitochondria have been widely reported, the mechanism behind the toxicity remains unclear. In this study, the effects of two forms of silver (AgNPs and AgNO3) on carp gill mitochondria were investigated by analyzing the mitochondrial ultrastructure, physicochemical properties of mitochondrial membrane, and mitochondrial proteomics. After exposure of common carp to AgNPs (0.75 mg/L) and AgNO3 (0.05 mg/L) for 96 h, both forms of silver were shown to cause gill mitochondrial lesions, including irregular shape, loss of mitochondrial cristae, and increased mitochondrial membrane permeability. Proteomics results revealed that AgNPs and AgNO3 induced 362 and 297 differentially expressed proteins (DEPs) in gill mitochondria, respectively. Among the DEPs, 244 were shared between AgNPs and AgNO3 treatments. These shared proteins were mainly distributed in the mitochondrial membrane and matrix, and were significantly enriched in the tricarboxylic acid (TCA) cycle and oxidative phosphorylation pathway. The functional annotation of DEPs induced by both silver forms was mainly involved in energy production and conversion. These results indicated that the toxic mechanism of AgNPs and AgNO3 on gill mitochondria were comparable and the two forms of silver caused mitochondrial dysfunction in fish gills by inhibiting the TCA cycle and disrupting the electron transport chain.

Trophodynamics and health risk assessment of toxic trace metals in the food web of a plateau freshwater lake.

The trophodynamics of toxic trace metals is significant for assessing the threat of toxic trace metals to the aquatic ecosystem and human safety. However, due to the difficulty of accurately calculating the trophic positions of freshwater aquatic organisms in the food web, the comprehensive process of trophodynamics of toxic trace metals in freshwater ecosystems was still rarely known. By integrating the compound-specific nitrogen stable isotopic analysis of amino acids (CSIA-AAs) and the Bayesian stable isotope mixing model (SIMM) as a novel approach, the present study investigated the trophodynamics of five toxic trace metals (Zn, As, Cr, Cu, and Hg) in the food web of the YangZong Lake, a plateau freshwater lake that was once heavily polluted by arsenic in Yunnan Province, China. The results revealed that Hg tended to be efficiently biomagnified in the food web with a trophic magnification factor of 1.75; As, Cr, and Cu were biodiluted significantly, while Zn showed no biomagnification or biodilution trends. The dietary health risk assessment indicated the potential health risk of toxic trace metals for the local residents of long-term fish consumption. The present work highlights the accuracy and reliability of the novel CSIA-AAS+SIMM approach in the calculation of the trophic positions of freshwater organisms.

Metabolic profiling of nanosilver toxicity in the gills of common carp.

Studies have shown silver nanoparticles (AgNPs) exposure can result in a series of toxic effects in fish gills. However, it is still unclear how AgNPs affect metabolite expression and their related molecular metabolic pathways in fish gills. In this study, we employed untargeted metabolomics to study the effects of AgNPs and silver supernatant ions on fish gill metabolites. The results showed that AgNPs can induce significant changes in 96 differentially expressed metabolites, which mainly affect amino acid metabolism and energy metabolism in fish gills. Among these metabolites, AgNPs specifically induce significant changes in 72 differentially expressed metabolites, including L-histidine, L-isoleucine, L-phenylalanine, and citric acid. These metabolites were significantly enriched in the pathways of aminoacyl-tRNA biosynthesis, ABC transporters, and the citrate cycle. In contrast, Ag+ supernatant exposure can specifically induce significant changes in 14 differentially expressed metabolites that mainly interfere with sphingolipid metabolism in fish gills. These specifically regulated fish gill metabolites include sphinganine, sphingosine, and phytosphingosine, which were significantly enriched in the sphingolipid metabolism pathway. Our results clearly reveal the effects and potential toxicity mechanisms of AgNPs on fish gill metabolites. Furthermore, our study further determined the unique functions of released silver ions in AgNPs toxicity in fish gills.

Clinical experience on diagnosis and treatment for malignancy originating from the dacryocyst.

OBJECTIVE: To summarize clinical experience on the diagnosis and treatment for malignancy originating from the dacryocyst. METHODS: We retrospectively analyzed clinicopathological data from 12 cases that were diagnosed with malignancy originating from the dacryocyst by histopathological examination in our hospital from 2007 to 2017. RESULTS: Of the 12 cases with malignancy originating from the dacryocyst, 7 were male and 5 were female, with a mean age of 53 years (range, 4-81). Clinical manifestations included a mass in the dacryocyst area in 12 cases, epiphora in 9 cases, pyoid tears in 2 cases, bloody tears in 3 cases, and redness and swelling in the dacryocyst area in 2 cases. Lymphoma occurred in six cases, malignant melanoma in three cases, embryonal rhabdomyosarcoma in one case, and squamous cell carcinoma in two cases. CONCLUSIONS: Misdiagnosis and missed diagnosis readily occur for malignancy originating from the dacryocyst because its clinical manifestations are diverse. For the suspected patients, it is necessary to perform related examinations. Individualized treatment should be adopted based on pathological types and specific conditions.