Developmental toxicity and mechanism of polychlorinated biphenyls 126 and nano-polystyrene combined exposure to zebrafish larvae.

3,3',4,4',5-Pentachlorobiphenyl (PCB126) is the most toxic congener of dioxin-like polychlorinated biphenyls (DL PCBs), while nanoplastics (NPs) have recently emerged as significant marine pollutants, both posing threats to aquatic organisms and human health. They coexist in the environment, but their comprehensive toxicological effects remain unclear. In this study, zebrafish embryos were simultaneously exposed to PCB126 and 80-nanometer nanoplastyrene (NPS). Researchers utilized fluorescence microscopy, qPCR, histopathological examination, and transcriptomic sequencing to investigate the developmental toxicity of different concentrations of PCB126 and NPS individually or in combination on zebrafish embryos and larvae. Results indicate that the chorion significantly impedes the accumulation of NPS (p < 0.05). It is noteworthy that this barrier effect diminishes upon simultaneous exposure to PCB126. In this experiment, the semi-lethal concentration of PCB126 for larvae was determined to be 6.33 µg/L. Exposure to PCB126 induces various deformities, primarily mediated through the aryl hydrocarbon receptor (AHR). Similarly, exposure to NPS also activates AHR, leading to developmental impairments. Furthermore, transcriptomic sequencing revealed similar effects of PCB126 and NPS on the gene expression trends in zebrafish larvae, but combined exposure to both exacerbates the risk of cancer and induces more severe cardiac toxicity. At this level, co-exposure to PCB126 and NPS adversely affects the development of zebrafish larvae. This study contributes to a deeper understanding of the in vivo accumulation of DL polychlorinated biphenyls and microplastics in actual aquatic environments and their impact on fish development.

PCB169 exposure aggravated the development of non-alcoholic fatty liver in high-fat diet-induced male C57BL/6 mice.

Polychlorinated biphenyls (PCBs) are lipophilic environmental toxicants. Epidemiological studies have established a link between PCBs and both metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). Multiple studies have reported that exposure to both PCB156 and PCB126 among the 12 dioxin-like PCBs leads to the development of NAFLD. However, studies to elucidate whether PCB169 induces the development of NAFLD by constructing in vivo models have not been reported. Therefore, we evaluated the effects of exposure to PCB169 (5 mg/kg-bw) on hepatic lipid metabolism in C57BL/6 mice from control diet and high-fat diet cohorts. The results showed that PCB169 exposure reduced body weight and intraperitoneal fat mass in mice on the control diet, but the liver lipid levels were significantly increased, exacerbating NAFLD in mice on a high-fat diet. Through transcriptomics studies, it was found that PCB169 exposure induced significant up-regulation of Pparγ, Fasn, and Aacs genes involved in hepatic lipogenesis, as well as remarkable up-regulation of Hmgcr, Lss, and Sqle genes involved in cholesterol synthesis. Additionally, there was notable down-regulation of Pparα and Cpt1 genes involved in lipid ß-oxidation, leading to abnormal lipid accumulation in the liver. In addition, we found that PCB169 exposure significantly activated the Arachidonic acid metabolism, PPAR signaling pathway, Metabolism of xenobiotics by cytochrome P450, and Retinol metabolism pathways, and so on. Our study suggests that PCB169 can modify gene expression related to lipid metabolism, augument lipid accumulation in the liver, and further contribute to the development of NAFLD, thereby revealing the detrimental effects associated with PCB exposure on animal growth and metabolism.

Snake-shaped ePTFE nasal tip graft combined with conchal cartilage in Asian rhinoplasty: a retrospective cohort study.

BACKGROUND: Lacking a nasal tip projection is a common deformity of Asian nasals. Various commonly used nasal tip grafts require dissecting septal perichondrium, most of them are autologous cartilage with a nonintegrated design. A snake-shaped expanded polytetrafluoroethylene (ePTFE) nasal tip graft is an integrated, stable tip graft without any additional assembly and splicing, conforming to the nasal anatomy characteristics of Asians. METHOD: A retrospective study was performed on Asian patients who underwent rhinoplasty in the nasal tip at Peking University Third Hospital from 2015 to 2022. Nasal tip grafts were categorized into three groups: snake-shaped ePTFE combined with conchal cartilage (n = 15), only costal cartilage (n = 25), and only conchal cartilage (n = 17). Patients were excluded if their rhinoplasty did not involve any of the grafts above. Visual Analogue Scale, FACE-Q Nose, FACE-Q Nostril, Nasal Obstruction Symptom Evaluation scale, and Rhinoplasty Outcome Evaluation scale were used to evaluate the preoperative and postoperative results. RESULTS: Fifty-three (93.0%) cases had low nasal dorsum and 46 (80.7%) cases had short nose. There was no significant difference in complication rates among the three groups. The difference between preoperative and postoperative scale scores was statistically significant among the three groups (p < 0.05). Score improvements, including all scales, were the highest in the costal cartilage group and lowest in the conchal cartilage group. CONCLUSIONS: Snake-shaped ePTFE nasal tip grafts can be an effective integrated alternative that provides long-term safety and efficacy compared with traditional autogenous implants (conchal and costal cartilages).