Research on Pollution Identification and Safety Thresholds Based on the Olfactory Effect on a Halogenated Hydrocarbon Contaminated Site.

To effectively address odor control issues at sites contaminated with halogenated hydrocarbons, it is essential to establish an odor risk prediction system for evaluating potential risks that may impact future planning. This research focuses on a representative halogenated hydrocarbon-contaminated site, examining the spatial and temporal distribution characteristics of key pollutants in soil gas. By analyzing odor contribution rates, the study identifies significant odorants in soil gas, which enables the derivation of both probabilistic and deterministic safety thresholds for soil and groundwater based on olfactory effects. The findings indicate that 1,1-dichloroethylene, vinyl chloride, chloroform, and 1,1-dichloroethane are prevalent throughout the contaminated site, displaying elevated concentration levels and substantially influencing the overall contamination extent. These substances are highlighted as critical pollutants requiring attention. Correlation analysis (P < 0.05) reveals a strong relationship between the concentrations of vinyl chloride, 1,1-dichloroethane, and chloroform with groundwater depth and air temperature. Additionally, the analysis of odor activity values (OAV) identified 1,1-dichloroethene, 1,4-dichlorobenzene, chlorobenzene, chloroform, and vinyl chloride as key olfactory factors at the site. The corresponding probabilistic safety thresholds are 0.68, 1.65, 0.50, 7.87, and 3.72 mg·kg-1 for soil, and 9.29, 3.46, and 1.09, 69.55, and 47.01 mg·L-1 for groundwater, respectively. Among them, the odor risks of chlorobenzene and 1,1-dichloroethylene warrant more attention than soil contamination risks; regarding 1,4-dichlorobenzene, it is recommended to concurrently consider odor risks during human health risk assessment; as for vinyl chloride and chloroform, their odor risks can be largely eliminated based on human health-oriented pollution management.

Applying Red Mud in Cadmium Contamination Remediation: A Scoping Review.

Red mud is an industrial solid waste rarely utilized and often disposed of in landfills, resulting in resource waste and environmental pollution. However, due to its high pH and abundance of iron and aluminum oxides and hydroxides, red mud has excellent adsorption properties which can effectively remove heavy metals through ion exchange, adsorption, and precipitation. Therefore, red mud is a valuable resource rather than a waste byproduct. In recent years, red mud has been increasingly studied for its potential in wastewater treatment and soil improvement. Red mud can effectively reduce the migration and impact of heavy metals in soils and water bodies. This paper reviews the research results from using red mud to mitigate cadmium pollution in water bodies and soils, discusses the environmental risks of red mud, and proposes key research directions for the future management of red mud in cadmium-contaminated environments.

Risk assessment and source analysis of heavy metals in soil around an asbestos mine in an arid plateau region, China.

Asbestos is widely used in construction, manufacturing, and other common industrial fields. Human activities such as mining, processing, and transportation can release heavy metals from asbestos into the surrounding soil environment, posing a health hazard to the mining area's environment and its surrounding residents. The purpose of the present study was to determine the extent of ecological and human health damage caused by asbestos pollution, as well as the primary contributors to the contamination, by examining a large asbestos mine and the surrounding soil in China. The level of heavy metal pollution in soil and sources were analyzed using methods such as the geo-accumulation index (Igeo), potential ecological risk index (RI), and positive matrix factorization (PMF) model. A Monte Carlo simulation-based health risk model was employed to assess the health risks of heavy metals in the study area's soil to human beings. The results showed that the concentrations of As, Pb, Cr, Cu, and Ni in the soil were 1.74, 0.13, 13.31, 0.33, and 33.37 times higher than the local soil background values, respectively. The Igeo assessment indicated significant accumulation effects for Ni, Cr, and As. The RI evaluation revealed extremely high comprehensive ecological risks (RI ≥ 444) in the vicinity of the waste residue heap and beneficiation area, with Ni exhibiting strong individual potential ecological risk (Eir ≥ 320). The soil health risk assessment demonstrated that As and Cr posed carcinogenic risks to adults, with mean carcinogenic indices (CR) of 1.56E - 05 and 4.14E - 06, respectively. As, Cr, and Cd posed carcinogenic risks to children, with mean CRs of 1.08E - 04, 1.61E - 05, and 2.68E - 06, respectively. Cr also posed certain non-carcinogenic risks to both adults and children. The PMF model identified asbestos contamination as the primary source of heavy metals in the soil surrounding the asbestos mining area, contributing to 79.0%. According to this study, it is recommended that management exercise oversight and regulation over the concentrations of Ni, Cr, Cd, and As in the soil adjacent to asbestos mines, establish a designated control zone to restrict population activities, and locate residential zones at a safe distance from the asbestos mine production zone.

Can we redevelop ammonia nitrogen contaminated sites without remediation? The key role of subsurface pH in human health risk assessment.

Nitrogen fertilizer supports global food production, but its manufacturing results in substantial ammonia nitrogen (AN) contaminated sites which remain largely unexplored. In this study, ten representative AN contaminated sites were investigated, covering a wide range of subsurface pH, temperature, and AN concentration. A total of 7232 soil samples and 392 groundwater samples were collected to determine the concentration levels, migration patterns, and accurate health risks of AN. The results indicated that AN concentrations in soil and groundwater reached 12700 mg/kg and 12600 mg/L, respectively. AN concentrations were higher in production areas than in non-production areas, and tended to migrate downward from surface to deeper soil. Conventional risk assessment based on AN concentration identified seven out of the ten sites presenting unacceptable risks, with remediation costs and CO2 emissions amounting to $1.67 million and 17553.7 tons, respectively. A novel risk assessment model was developed, which calculated risks based on multiplying AN concentration by a coefficient fNH3 (the ratio of NH3 to AN concentration). The mean fNH3 values, primarily affected by subsurface pH, varied between 0.02 and 0.25 across the ten sites. This new model suggested all investigated sites posed acceptable health risks related to AN exposure, leading to their redevelopment without AN-specific remediation. This research offers a thorough insight into AN contaminated site, holds great realistic significance in alleviating global economic and climate pressures, and highlights the need for future research on refined health risk assessments for more contaminants.

An Analysis of the Spatial Characteristics and Transport Fluxes of BTEX in Soil and Atmospheric Phases at a Decommissioned Steel Mill Site in China with a Long History.

BTEX (benzene, toluene, ethylbenzene, and xylene), as characteristic pollutants in chemical plant sites, are widely present in the environment and pose a serious threat to the health and safety of nearby residents. Studying the spatial distribution characteristics and transport fluxes of BTEX in soil and air at contaminated sites and the health risks they pose to humans is of great significance for fine pollution control and environmental management. This study took a typical decommissioned steel plant as a case study. A total of 23 soil and air samples were collected from different locations to investigate the spatial distribution characteristics of BTEX in soil and air. The transport and fate of BTEX in soil and air were evaluated using the fugacity model, and finally, a human health risk assessment was conducted. The results indicate a relatively severe level of benzene pollution in both soil and air. The maximum exceedance factor of benzene in soil samples is 31.5, with the concentration exceedance depth at 1.5 m. The maximum concentration of benzene in air samples is 4.98 µg·m-3. Benzene, at 5.9% of the site, shows a low flux with negative values, while other components at various locations all exhibit a trend of transport from the soil phase to the atmospheric phase. Benzene is the pollutant that contributes the most to the transport flux from soil to air within the site. The coking area and sewage treatment area are key areas within the steel mill where BTEX accumulate easily in the soil. The non-carcinogenic risk values of the individual components of BTEX in the soil are below the acceptable risk level. However, the carcinogenic risk value of benzene in the children's exposure scenario exceeds the carcinogenic risk level of 10-6. The carcinogenic risk range of various components of BTEX in the air is 2.63 × 10-6~3.88 × 10-5, with 28.6% of the locations exceeding the threshold of 10-6. The range of the total HI (hazard index) is 2.08 × 10-4~1.81 × 10-1, all of which is below the safety threshold of 1. The results of this study will provide scientific support for the fine pollution control and environmental management of industrial contaminated sites with BTEX as their typical pollutants.

Asbestos-Environment Pollution Characteristics and Health-Risk Assessment in Typical Asbestos-Mining Area.

Asbestos has been confirmed as a major pollutant in asbestos-mining areas that are located in western China. In general, asbestos-fibre dust will is released into the environment due to the effect of intensive industrial activities and improper environmental management, such that the health of residents in and around mining areas is jeopardised. A typical asbestos mining area served as an example in this study to analyse the content and fibre morphology of asbestos in soil and air samples in the mining area. The effects of asbestos pollution in and around the mining areas on human health were also assessed based on the U.S. Superfund Risk Assessment Framework in this study. As indicated by the results, different degrees of asbestos pollutions were present in the soil and air, and they were mainly concentrated in the mining area, the ore-dressing area, and the waste pile. The concentration of asbestos in the soil ranged from 0.3% to 91.92%, and the concentration of asbestos fibres in the air reached 0.008-0.145 f·cc-1. The results of the scanning-electron microscope (SEM) energy suggested that the asbestos was primarily strip-shaped, short columnar, and granular, and the asbestos morphology of the soils with higher degrees of pollution exhibited irregular strip-shaped fibre agglomeration. The excess lifetime cancer risk (ELCR) associated with the asbestos fibres in the air of the mining area was at an acceptable level (10-4-10-6), and 40.6% of the monitoring sites were subjected to unacceptable non-carcinogenic risks (HQ > 1). Moreover, the waste pile was the area with the highest non-carcinogenic risk, followed by the ore dressing area, a residential area, and a bare-land area in descending order. In the three scenarios of adult offices or residences in the mining area, adults' outdoor activities in the peripheral residence areas, and children's outdoor activities, the carcinogenic-and non-carcinogenic-risk-control values in the air reached 0.1438, 0.2225 and 0.1540 f·cc-1, and 0.0084, 0.0090 and 0.0090 f·cc-1, respectively. The results of this study will lay a scientific basis for the environmental management and governance of asbestos polluted sites in China.

Evaluation of Anti-Burst Performance in Mining Roadway Support System.

The hazardous effect of a mine earthquake on a roadway is not only related to its energy scale but also to its distance from the roadway. In this study, a signal attenuation model and a disaster-causing model were established to evaluate the mine earthquake effects based on peak particle velocity (PPV) data recorded for 37221-1 upper roadway of the Dongxia Coal Mine, China. The characteristic of dynamic loads due to mine earthquake propagation to roadway surfaces was researched, and critical PPV values were identified using FLAC3D numerical simulation, which can be used to evaluate the roadway anti-burst performance under the existing support system. The results show that the support system is able to resist a mine earthquake with energy below 2.33 × 103 J; however, considering the energy accumulation volume of surrounding rocks and the range of source fracture, the maximum resistible mine earthquake energy can be up to 7.09 × 106 J when the roadway is 50 m away from the source. The validity and applicability of the disaster-causing models was verified by two rockburst cases that occurred during the excavation of the working face.

Spatial-Temporal Distribution, Morphological Transformation, and Potential Risk of Dissolved Inorganic Nitrogen in the Contaminated Unconfined Aquifer from a Retired Nitrogenous Fertilizer Plant.

The accumulation of nitrogen in groundwater in the industrial plots, especially the high ammonium, can result in a serious threat to the groundwater system in the urban area. This study monitored the dissolved inorganic nitrogen (DIN) of the polluted groundwater four times in one year in a retired nitrogenous fertilizer plant site with a production history of nearly 40 years, to analyze the spatial-temporal characteristics of DIN species (NH4+-N, NO3−-N, and NO2−-N) and the effects of groundwater environment on their transfer and transformation. The results showed that NH4+-N (<0.025 to 1310 mg/L) was the main DIN species (61.38−76.80%) with low mobility, whereas the concentration of NO3−-N and NO2−-N was 0.15−146 mg/L and <0.001−12.4 mg/L, accounting for 22.34−36.07% and 0.53−2.83% of total DIN, respectively. The concentration and proportion of NO3−-N and NO2−-N showed an upward trend with time, posing a threat to the safety of surrounding groundwater, and their high spatial-temporal variation was related to the morphological transformation and the transport. In the wet season, the pH and redox condition benefited the nitrification, and NO3−-N easily migrated from the deep soil solution to groundwater, hence the NO3−-N can be accumulated. Therefore, the analysis of species and behaviors of DIN in shallow groundwater is indispensable for environmental risk assessment.

Disposable plastic materials release microplastics and harmful substances in hot water.

The boom in the takeaway industry has significantly increased the consumption of disposable plastic materials, which are very likely to release microplastic particles and cause secondary risks during daily use. The objective of this study was to probe whether heat treatment of disposable plastic materials in water, mimicking their use for hot food or drink, could result in the release of particles and harmful substances in the leachate. Our results showed that a hot water (100 °C) soaking released 1.07 ± 0.507, 1.44 ± 0.147, 2.24 ± 0.719 and 1.57 ± 0.599 million submicron and microparticles/mL from plastic packaging, cups, transparent boxes and expandable boxes, respectively after 60 min of agitation, and the submicron fraction was dominant. Based on Fourier transform infrared spectroscopy, heat treatment also altered the chemical composition of polyethylene packaging, but it had minor effects on polypropylene cups, transparent boxes and polystyrene expandable boxes. In addition, organic chemicals and heavy metals (mainly As, Cr and Pb), with maximum concentrations of 2.1 ± 0.85 mgC/L and 4.2 ± 0.32 ng/L, were detected in the leachate from plastic packaging, cups and expandable boxes, indicating the potential risk of these materials while holding hot food or drink. The findings suggest the potential ingestion risk of microplastics and harmful substances by human beings during the daily use of disposable plastic materials.

Source apportionment and health risk assessment of chemicals of concern in soil, water and sediment at a large strontium slag pile area.

Strontium (Sr) is an alkaline earth metal that has adverse effects on bone tissue, but received little attention compared to other often-studied metals. This study analyzed the contents/concentrations of Sr, barium (Ba), sulfate (SO42-), sulfide (S2-), and six common metals in 209 multi-media samples, including slag, soil, groundwater, surface water, and sediment, collected at a large Sr slag pile area. Sr was the dominant chemical of concern (COC) in the soil and groundwater, with contents/concentrations being 35.50-32200 mg/kg and 0.57-152 mg/L, respectively, much higher than those reported in previous research. Contents/concentrations of all COCs in the surface water and sediment were relatively low, except Sr content in the sediment near the slag pile. The LogKd value of Sr was calculated to be lower than those of common metals, indicating relatively high mobility of Sr in the aquatic environment. Contamination assessment using Nemerow index indicated near half of the soil and groundwater sampling locations, especially those within and near the slag pile, were heavily contaminated, and Sr was the dominant COC. The positive matrix factorization model suggested four sources for the COCs in soil, including Sr slag pile/SrCO3 production, agricultural activities, industrial activities, and natural sources, with contribution rates of 66.88%, 5.28%, 7.5%, and 20.34%, respectively. Monte Carlo simulation-based probabilistic health risk assessment revealed that the non-carcinogenic risk of groundwater, and the carcinogenic risk of soil and groundwater, were unacceptable. Notably, Sr was the unique COC posing non-carcinogenic risk among the COCs studied. Our results provide the scientific support needed for managing Sr point source impacted area.

Novel risk models to predict acute kidney disease and its outcomes in a Chinese hospitalized population with acute kidney injury.

Acute kidney disease (AKD) is a state between acute kidney injury (AKI) and chronic kidney disease (CKD), but the prognosis of AKD is unclear and there are no risk-prediction tools to identify high-risk patients. 2,556 AKI patients were selected from 277,898 inpatients of three affiliated hospitals of Central South University from January 2015 to December 2015. The primary point was whether AKI patients developed AKD. The endpoint was death or end stage renal disease (ESRD) 90 days after AKI diagnosis. Multivariable Cox regression was used for 90-day mortality and two prediction models were established by using multivariable logistic regression. Our study found that the incidence of AKD was 53.17% (1,359/2,556), while the mortality rate and incidence of ESRD in AKD cohort was 19.13% (260/1,359) and 3.02% (41/1,359), respectively. Furthermore, adjusted hazard ratio of mortality for AKD versus no AKD was 1.980 (95% CI 1.427-2.747). In scoring model 1, age, gender, hepatorenal syndromes, organic kidney diseases, oliguria or anuria, respiratory failure, blood urea nitrogen (BUN) and acute kidney injury stage were independently associated with AKI progression into AKD. In addition, oliguria or anuria, respiratory failure, shock, central nervous system failure, malignancy, RDW-CV ≥ 13.7% were independent risk factors for death or ESRD in AKD patients in scoring model 2 (goodness-of fit, P1 = 0.930, P2 = 0.105; AUROC1 = 0.879 (95% CI 0.862-0.896), AUROC2 = 0.845 (95% CI 0.813-0.877), respectively). Thus, our study demonstrated AKD was independently associated with increased 90-day mortality in hospitalized AKI patients. A new prediction model system was able to predict AKD following AKI and 90-day prognosis of AKD patients to identify high-risk patients.

Post-contrast acute kidney injury in a hospitalized population: short-, mid-, and long-term outcome and risk factors for adverse events.

OBJECTIVES: To investigate the prognosis including major adverse kidney events within 30 days (MAKE30) and 90-day and 1-year adverse outcome in hospitalized patients with post-contrast acute kidney injury (PC-AKI) to identify high-risk factors. METHODS: This retrospective observational study included 288 PC-AKI patients selected from 277,898 patients admitted to hospitals from January 2015 to December 2015. PC-AKI was defined according to the 2018 guideline of European Society of Urogenital Radiology. Multivariable Cox regression and logistic regression analyses were used to analyze main outcome and risk factors. RESULTS: PC-AKI patients with AKI stage ≥ 2 had much higher incidence of MAKE30 than those with AKI stage 1 (RR = 7.027, 95% CI 4.918-10.039). Persistent renal dysfunction, heart failure, central nervous system failure, baseline eGFR < 60 mL/min/1.73 m2, oliguria or anuria, blood urea nitrogen ≥ 7.14 mmol/L, respiratory failure, and shock were independent risk factors of 90-day or 1-year adverse prognosis (p < 0.05). Compared with transient renal dysfunction, PC-AKI patients with persistent renal dysfunction had a higher all-cause mortality rate (RR = 3.768, 95% CI 1.612-8.810; RR = 4.106, 95% CI 1.765-9.551) as well as combined endpoints of death, chronic kidney disease, or end-stage renal disease (OR = 3.685, 95% CI 1.628-8.340; OR = 5.209, 95% CI 1.730-15.681) within 90 days or 1 year. CONCLUSIONS: PC-AKI is not always a transient, benign creatininopathy, but can result in adverse outcome. AKI stage is independently correlated to MAKE30 and persistent renal dysfunction may exaggerate the risk of long-term adverse events. KEY POINTS: • PC-AKI can result in adverse outcome such as persistent renal dysfunction, dialysis, chronic kidney disease (CKD), end-stage renal disease (ESRD), or death. • AKI stage is independently correlated to MAKE30. • Persistent renal dysfunction may exaggerate the risk of long-term adverse events.

Multi-plasmon resonances enhanced two-photon coherent anti-Stokes Raman scattering by nanorods.

The development of new structures allows two-photon coherent anti-Stokes Raman scattering (TPCARS) to be strongly enhanced by multiple surface plasmon resonances (MSPRs). In this paper, plasmonic structure consisting of two Ag nanorods is designed and the enhancement of TPCARS is investigated. By properly selecting designing structure parameters, strong MSPRs peaks at 1020 nm and 505 nm are obtained, which can enhance the TPCARS signal based on the frequency match of the fundamental frequency and frequency doubling. The enhancement factor of TPCARS can reach as high as 3.66 × 1028 with significant electric field enhancements under appropriate selection of system parameters. Furthermore, the two-photon process can be controlled at different optical frequencies by changing the geometric parameters of Ag nanorods. The new scheme advanced in this work can help to achieve single molecule level of CARS, and may have a potential to increase the intensity and resolution of nonlinear optical imaging.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats.

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7 (MMP-7) in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

Human umbilical cord blood mononuclear cells protect against renal tubulointerstitial fibrosis in cisplatin-treated rats.

Currently, there is no effective method to prevent renal interstitial fibrosis after acute kidney injury (AKI). In this study, we established and screened a new renal interstitial fibrosis rat model after cisplatin-induced AKI. Our results indicated that rats injected with 4 mg/kg cisplatin once a week for two weeks after firstly administrated with 6.5 mg/kg loading dose of cisplatin could set up a more accurate model reflecting AKI progression to renal interstitial fibrosis. Then, we investigated the effects and possible mechanisms of human umbilical cord blood mononuclear cells (hUCBMNCs) on renal tubular interstitial fibrosis after cisplatin-induced AKI. In rats injected with hUCBMNCs for four times, level of matrix metalloproteinase 7(MMP-7)in serum and urine, urinary albumin/creatinine ratio, tubular pathological scores, the relative collagen area of the tubulointerstitial region, endoplasmic reticulum dilation and the mitochondrial ultrastructural damage were significantly improved. The level of reactive oxygen species, α-smooth muscle actin (α-SMA), [NOD]-like pyrin domain containing protein 3 and cleaved-Caspase 3 in renal tissue decreased significantly. However, in rats injected with hUCBMNCs for two times, no significant difference was discovered in MMP-7 levels and urinary albumin/creatinine ratio. Although expression of α-SMA and the percentage areas of collagen staining in tubulointerstitial tissues were ameliorated in rats injected with hUCBMNCs for two times, the effects were significantly weaker than those in rats injected with hUCBMNCs for four times. Taken together, our study constructed a highly efficient, duplicable novel rat model of renal fibrosis after cisplatin-induced AKI. Multiple injections of hUCBMNCs may prevent renal interstitial fibrosis after cisplatin-induced AKI.

Non-coding RNA-Associated ceRNA Networks in a New Contrast-Induced Acute Kidney Injury Rat Model.

Contrast-induced acute kidney injury (CI-AKI) is a severe complication of intravascular applied radial contrast media, and recent progress in interventional therapy and angiography has revived interest in explaining detailed mechanisms and developing effective treatment. Recent studies have indicated a potential link between CI-AKI and microRNA (miRNA). However, the potential non-coding RNA-associated-competing endogenous RNA (ceRNA) pairs involved in CI-AKI still remain unclear. In this study, we systematically explored the circRNA or lncRNA-associated-ceRNA mechanism in a new rat model of CI-AKI through deep RNA sequencing. The results revealed that the expression of 38 circRNAs, 12 lncRNAs, 13 miRNAs and 127 mRNAs were significantly dysregulated. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses for mRNAs with significantly different expression and then constructed comprehensive circRNA or lncRNA-associated ceRNA networks in kidney of CI-AKI rats. Thereafter, two constructed ceRNA regulatory pathways in this CI-AKI rat model-novel_circ_0004153/rno-miR-144-3p/Gpnmb or Naglu and LNC_000343/rno-miR-1956-5p/KCP-were validated by real-time qPCR. This study is the first one to provide a systematic dissection of non-coding RNA-associated ceRNA profiling in kidney of CI-AKI rats. The selected non-coding RNA-associated ceRNA networks provide new insight for the underlying mechanism and may profoundly affect the diagnosis and therapy of CI-AKI.

Comparative effect of iso-osmolar versus low-osmolar contrast media on the incidence of contrast-induced acute kidney injury in diabetic patients: a systematic review and meta-analysis.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is a major adverse effect caused by intravascular administration of iodinated contrast medium. Whether there is a difference in CI-AKI incidence between iso-osmolar (IOCM) and low-osmolar contrast media (LOCM) among diabetic patients is controversial. METHODS: Randomized controlled trials comparing the nephrotoxic effects between IOCM and LOCM in diabetic patients with or without CKD (eGFR< 60 ml/min/1.73 m2) were included in the analysis. The incidence of CI-AKI was defined as an initial increase in serum creatinine (SCr) concentration of at least 0.5 mg/dl or a rise in creatinine of 25% from baseline. RESULTS: A total of 2190 patients were included, among whom 1122 patients received IOCM and 1068 received LOCM. When compared to LOCM, IOCM had no significant benefit in preventing CI-AKI (OR = 1.66, [CI: 0.97-2.84], P = 0.06, I2 = 54%). However, the difference between IOCM and LOCM was found when CI-AKI was defined as an absolute SCr increase (≥0.5 mg/dl) rather than a relative SCr increase (≥25%). Further analysis showed that LOCM resulted in more adverse events. CONCLUSIONS: Whether there is a difference of CI-AKI incidence between IOCM and LOCM in diabetic patients was related to the selected diagnostic criteria. The incidence of adverse events was significantly lower with IOCM when compared with LOCM. Therefore, we suggest that IOCM may be used in diabetic and CKD (eGFR< 60 ml/min/1.73 m2) patients.

Urinary proteomics analysis based on mass spectrometry and identification of therapeutic targets of Shenkangling interventions in rats with adriamycin nephropathy using iTRAQ.

OBJECTIVE: The isobaric tags for relative and absolute quantification (iTRAQ) technique for proteomic analysis was employed to identify diagnostic markers and therapeutic targets of Shenkangling intervention or prednisone tablets in rats with adriamycin nephropathy (AN). METHODS: Fifty healthy, clean-grade Sprague-Dawley rats were selected, with 10 rats in the normal group and the remaining 40 rats receiving a tail vein injection of 5.5 mg/kg of adriamycin (ADR) to induce AN. Treatment began 1 week later. The normal group received gastric administration of normal saline. Forty rats with induced AN were further randomly divided into the AN modeling group (n = 10), AN modeling + prednisone treatment group (n = 10), AN modeling + Shenkangling intervention group (n = 10), and AN modeling + prednisone + Shenkangling intervention group (n = 10). iTRAQ was employed in combination with mass spectrometry to analyze the differentially expressed proteins in the urine after 3 weeks of treatment (in the fourth week of the experiment). RESULTS: Compared with normal rats, AN rats had 6 down-regulated proteins and 1 upregulated protein. Compared with AN rats, prednisone rats had 2 down-regulated and 6 upregulated proteins. Compared with AN rats, combined treatment rats had 2 down-regulated and 8 upregulated proteins. Compared with the AN model group, the Shenkangling treatment group had 3 down-regulated and 9 upregulated proteins. Gro, Afamin, Cystatin-related protein 2, Afamin, and isoform CRA_a were considered diagnostic markers of primary nephrotic syndrome (PNS). Telomerase was considered the therapeutic target of prednisone. Urinary protein 2, Apolipoprotein A-II, 45 kDa calcium-binding protein, Vitronectin, and Osteopontin were the therapeutic targets of the Shenkangling intervention. Afamin, isoform CRA_a, Apolipoprotein A-IV, Coagulation factor XII, Prolactin-induced protein, and Coagulation factor XII were the therapeutic targets of the Shenkangling intervention combined with prednisone. CONCLUSION: The feasibility of urinary proteomics analysis in rats using a large number of proteins with finite molecular weights is controversial. The markers screened in this study may be of clinical value for the diagnosis and treatment of nephropathy. However, these findings should be confirmed in future cohort studies.

Comparison of iohexol and iodixanol induced nephrotoxicity, mitochondrial damage and mitophagy in a new contrast-induced acute kidney injury rat model.

Recent progress in angiography and interventional therapy has revived interest in comparison of nephrotoxicity of low-or iso-osmolar contrast media, but detailed mechanisms and effective treatments of contrast-induced acute kidney injury (CI-AKI) remain elusive. We established a new model of CI-AKI and compared the nephrotoxicity of iohexol and iodixanol with a focus on renal oxidative stress, mitochondrial damage and mitophagy. Our results showed that 48-h dehydration plus furosemide injection before iohexol administration successfully induced CI-AKI in rats. Compared with iodixanol, iohexol induced a greater decrease in renal function, more severe morphological damage and mitochondrial ultrastructural changes, an increased number of apoptotic cells, decreased antioxidative enzymes with activation of NLRP3 inflammasome in renal tissue. Renal contrast media kinetics showed the immediate excretion of iohexol and the transient renal accumulation of iodixanol. Plasma mtDNA Tc numbers were positively correlated with markers of renal mitochondrial disruption but negatively correlated with the level of serum creatinine and the score of tubular injury. Of note, iodixanol appeared to induce a stronger activation of mitophagy than iohexol, evidenced by greater protein levels of LC3II and PINK1/Parkin in the renal tissue of iodixanol-treated rats. Taken together, our results indicate that iohexol induced more severe nephrotoxicity than iodixanol in vivo due to apoptosis, destruction of antioxidative defense machinery, activation of NLRP3 inflammasome, mitochondrial damage and mitophagy. Plasma mtDNA may serve as a biological marker for renal mitochondrial disruption and damage in CI-AKI. Antioxidative defense and mitophagy are involved in the process of CI-AKI and may be promising targets of therapies.

Mitophagy Plays a Protective Role in Iodinated Contrast-Induced Acute Renal Tubular Epithelial Cells Injury.

BACKGROUND/AIMS: Contrast induced-acute kidney injury (CI-AKI) is one of the most common causes of acute kidney injury (AKI) in hospitalized patients. Mitophagy, the selective elimination of mitochondria via autophagy, is an important mechanism of mitochondrial quality control in physiological and pathological conditions. In this study, we aimed to determine effects of iohexol and iodixanol on mitochondrial reactive oxygen species (ROS), mitophagy and the potential role of mitophagy in CI-AKI cell models. METHODS: Cell viability was measured by cell counting kit-8. Cell apoptosis, mitochondrial ROS and mitochondrial membrane potential were detected by western blot, MitoSOX fluorescence and TMRE staining respectively. Mitophagy was detected by the colocalization of LC3-FITC with MitoTracker Red, western blot and electronic microscope. RESULTS: The results showed that mitophagy was induced in human renal tubular cells (HK-2 cells) under different concentrations of iodinated contrast media. Mitochondrial ROS displayed increased expression after the treatment. Rapamycin (Rap) enhanced mitophagy and alleviated contrast media induced HK-2 cells injury. In contrast, autophagy inhibitor 3-methyladenine (3-MA) down-regulated mitophagy and aggravated cells injury. CONCLUSIONS: Together, our finding indicates that iohexol and iodixanol contribute to the generation of mitochondrial ROS and mitophagy. The enhancement of mitophagy can effectively protect the kidney from iodinated contrast (iohexol)-induced renal tubular epithelial cells injury.