Hematological consequences of polyethylene microplastics toxicity in male rats: Oxidative stress, genetic, and epigenetic links.

Microplastics (MPs) pollution is a newly emerging environmental issue. MPs can accumulate within animals and humans, which can pose a serious health threat. Petroleum-based polyethylene (PE) is one of the most popular plastics. Accordingly, its exposure rates have steadily increased over the years. This study aimed to analyze the effects of PE-MPs on the hematological system of albino rats and the epigenetic effect. Five groups of adult male eight-weeks-old rats received either distilled water, corn oil, 3.75 mg/kg PE-MPs, 15 mg/kg PE-MPs, or 60 mg/kg of PE-MPs, daily by oral gavage for 35 days. PE-MPs significantly increased the body weights of the rats and lipid peroxidation, with concomitant reduction of superoxide dismutase activity and depletion of reduced glutathione, thus adversely affecting oxidants/antioxidants balance. Moreover, PE-MPs increased the % of abnormal RBCs, irregular cells, tear drop cells, Schistocyte cells, and folded cells. The genotoxic effects on DNA were evident by increased DNA damage, confirmed by the comet assay, in addition to increased DNA methylation. The effects of PE-MPs have been shown to be dose correlated. In conclusion, this study provides evidence of dose-related PE-MPs-induced hematological, genotoxic, and epigenetic effects in mammals, and thus emphasizes the potentially hazardous health effects of environmental PE-MPs.

Evaluation of Perfusion Index as a Predictor of Vasopressor Requirement in Patients with Severe Sepsis.

We evaluated the ability of perfusion index (PI) to predict vasopressor requirement during early resuscitation in patients with severe sepsis. All consecutive patients with clinically suspected severe sepsis as defined by the criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference were included. Perfusion variables included PI, arterial lactate level, central venous oxygen saturation, and the difference between central venous carbon dioxide and arterial carbon dioxide pressures, and were recorded before resuscitation and 6 h thereafter. We enrolled 36 patients with severe sepsis. Twenty-one patients required vasopressors, whereas 15 did not. The cut-off of the PI value for predicting vasopressor requirement was ≤0.3. This cut-off value had a sensitivity of 100% and a specificity of 93%; the area under the curve was 0.96 (95% confidence interval 0.8-0.99, P < 0.0001). The cut-off of the arterial lactate level for predicting vasopressor requirement was ≥1.8 mg dL. This cut-off value had a sensitivity of 82% and a specificity of 80%; the area under the curve was 0.84 (95% confidence interval 0.68-0.94, P < 0.0001). Other perfusion variables failed to predict vasopressor requirement in patients with severe sepsis. We concluded that PI and arterial lactate level are good predictors of vasopressor requirement during early resuscitation in patients with severe sepsis. Further studies are warranted to investigate whether monitoring PI during resuscitation improves the outcome of patients with septic shock.