1.Effects of mesencephalic astrocyte-derived neurotrophic factor on sepsis-associated acute kidney injury
World Journal of Emergency Medicine 2023;14(5):386-392
BACKGROUND: To determine the protective role of mesencephalic astrocyte-derived neurotrophic factor (MANF) in regulating sepsis-associated acute kidney injury (S-AKI).
METHODS: A total of 96 mice were randomly divided into the control group, control+MANF group, S-AKI group, and S-AKI+MANF group. The S-AKI model was established by injecting lipopolysaccharide (LPS) at 10 mg/kg intraperitoneally. MANF (200 μg/kg) was administered to the control+MANF and S-AKI+MANF groups. An equal dose of normal saline was administered daily intraperitoneally in the control and S-AKI groups. Serum and kidney tissue samples were obtained for biochemical analysis. Western blotting was used to detect the protein expression of MANF in the kidney, and enzyme-linked immunosorbent assay (ELISA) was used to determine expression of MANF in the serum, pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]). Serum creatinine (SCr), and blood urea nitrogen (BUN) were examined using an automatic biochemical analyzer. In addition, the kidney tissue was observed for pathological changes by hematoxylin-eosin staining. The comparison between two groups was performed by unpaired Student’s t-test, and statistics among multiple groups were carried out using Tukey’s post hoc test following one-way analysis of variance (ANOVA). A P-value <0.05 was considered statistically significant.
RESULTS: At the early stage of S-AKI, MANF in the kidney tissue was up-regulated, but with the development of the disease, it was down-regulated. Renal function was worsened in the S-AKI group, and TNF-α and IL-6 were elevated. The administration of MANF significantly alleviated the elevated levels of SCr and BUN and inhibited the expression of TNF-α and IL-6 in the kidney. The pathological changes were more extensive in the S-AKI group than in the S-AKI+MANF group.
CONCLUSION: MANF treatment may significantly alleviate renal injury, reduce the inflammatory response, and alleviate or reverse kidney tissue damage. MANF may have a protective effect on S-AKI, suggesting a potential treatment for S-AKI.
2.Assessment of intervention measures on trihalomethane in finished water by interrupted time series analysis
Yangyang REN ; Hailei QIAN ; Saifeng PEI ; Xiaodong SUN ; Zheng WU ; Chen WU ; Jingxian ZHOU ; Aimin DU ; Shaofeng SUI
Journal of Environmental and Occupational Medicine 2024;41(4):420-424
Background The Qingcaosha Reservoir is facing issues of algal blooms and eutrophication, and the resulting increase in the level of chlorination disinfection by-products in the water has been a major concern. Objective To evaluate the impact of "Algae Monitoring and Control Program in Qingcaosha Reservoir" (hereinafter referred to as the program) on the control of trihalomethanes (THMs) in conventional finished water. Methods From 2011 to 2019, water samples were collected from the Lujiazui Water Plant once per season, one sample each time, and the concentrations of four THMs (trichloromethane, dichlorobromomethane, monochlorodibromomethane, and tribromomethane) were measured in the samples. Using 2014 when the program was implemented as a cut-off point, the entire study period was divided into two phases: pre-implementation (2011–2013) and post-implementation(2014–2019). Segmented linear regression with interrupted time series analysis was applied to assess the concentrations and trends of THMs in the finished water before and after the program launch. Results The concentration of total THMs in finished water increased by 1.561 µg·L−1 (P=0.010) for each season of time extension before launching the program. The change in the concentration of total THMs in finished water was not statistically significant after the program launch, but the THMs concentration showed a decreasing trend as the slope was −0.626 (P=0.001). From 2017 until the end of 2019, the average concentration of THMs in finished water of Lujiazui Water Plant dropped to 10 μg·L−1 or less. Conclusions The algae and eutrophication control measures in Qingcaosha Reservoir have achieved good results, controlling THMs in finished water at a low level, and the trend of THMs has changed from a yearly increase pattern before the program to a yearly decrease pattern after the program.
3.Determination of 16 bisphenols in drinking water by online solid-phase extraction-ultra high-performance liquid chromatography tandem mass spectrometry
Chaoye SHEN ; Saifeng PEI ; Yuhang CHEN ; Heli CHENG ; Yun ZHANG
Journal of Environmental and Occupational Medicine 2024;41(10):1173-1179
Background Bisphenol compounds are non-persistent environmental endocrine disruptors and frequently detected in drinking water systems, indicating potential human health risks through drinking water. Objective To establish and optimize a simultaneous determination method for 16 BPs in drinking water by online solid-phase extraction-ultra high-performance liquid chromatography-triple quadrupole mass spectrometry, in order to efficiently monitoring BPs in drinking water. Methods Candidate online solid-phase extraction conditions, chromatographic columns, mobile phase systems, mass spectrometry parameters, and other conditions were compared by chromatographic peaks of BPs, and processing conditions such as water sample preservation and pretreatment were optimized. The pH level of drinking water samples was adjusted and solid particles were removed. After extraction and purification by an online solid-phase extraction system, samples were detected by ultra-high performance liquid chromatography tandem mass spectrometry and quantified by isotope internal standard method. The proposed method was verified by pure water and terminal tap water, and evaluated by spiked recovery rate and relative standard deviation. Eighty-eight tap water samples from different regions of local pipeline network were collected for method application. Results For the 16 BPs, the calibration curves showed good linearity between 1.0 and 75 ng·L−1 and the correlation coefficients were greater than 0.995. The detection limit of the method was less than 0.30 ng·L−1, and the quantification limit of the method was less than 1.0 ng·L−1. When the spiked concentrations for the 16 BPs were 5.0, 15, and 40 ng·L−1, the average spiked recovery rates of the test substances were between (100 ± 10)%, and the relative standard deviations were all below 10%. In the method application to the local terminal water samples, the positive rates of bisphenol S (BPS), bisphenol A (BPA), and bisphenol AF (BPAF) were as high as 93.2%, 77.3%, and 29.5%, respectively. The concentrations of BPS were from not detected (N.D.) to 37.8 ng·L−1, and the concentrations of BPA were from N.D. to 52.0 ng·L−1. Conclusion The method using an online solid-phase extraction system is established, featuring simple pre-treatment, small sample volume, high degree of automation, low detection limit, and good accuracy and precision. This method can be applied to the quantitative monitoring of 16 BPs at ng·L−1 level in drinking water.