Epidemiological studies have demonstrated the embryonic and developmental toxicity of plasticizers. Thus, understanding the in utero biotransformation and accumulation of plasticizers is essential to assessing their fate and potential toxicity in early life. In the present study, 311 infant hair samples and 271 paired meconium samples were collected at birth in Guangzhou, China, to characterize fetal exposure to legacy and emerging plasticizers and their metabolites.
View Article and Find Full Text PDFDespite the increasing production, use, and ubiquitous occurrence of novel brominated flame retardants (NBFRs), little information is available regarding their fate in aquatic organisms. In this study, the bioaccumulation and biotransformation of two typical NBFRs, i.e.
View Article and Find Full Text PDFThe tissue-specific bioaccumulation of Dechlorane Plus (DP) isomers was investigated in two predator fish species (redtail catfish, RF; and oscar fish, OF) that were feeding on tiger barb (TB), which was exposed to syn-DP and anti-DP isomers. The biotransformation potential of DP isomers was examined by in vitro metabolism using fish liver microsomes. No difference in accumulation behaviors of DP isomers was observed between RF and OF, and the accumulation of both syn- and anti-DP isomers exhibiting a linear increase trend with the exposure time in all fish tissues.
View Article and Find Full Text PDFFetal exposure to multiple organic contaminants (OCs) is a public concern because of the adverse effects of OCs on early life development. Infant hair has the potential to be used as an alternative matrix to identify susceptible fetuses, owing to its reliability, sensitivity, and advantages associated with sampling, handling, and ethics. However, the applicability of infant hair for assessing in utero exposure to OCs is still limited.
View Article and Find Full Text PDFSichuan Da Xue Xue Bao Yi Xue Ban
November 2020
Objective: In order to provide guidance for clinical use of four-dimensional cone-beam CT (4D CBCT), the accuracy of image registration and its influencing factors were analyzed using the automatic registration method when 4D CBCT was used as an image guidance strategy for patients with chest tumors.
Methods: The respiratory motion model and two kinds of lung plug-ins were used to simulate two types of tumors and their movements in the chest. 4D CT was scanned for each kind of simulated tumor, and 4D CBCT was scanned under various artificial positioning errors.
High levels of exposure to heavy metals and persistent organic pollutants (POPs) by e-waste dismantling workers has attracted increasing attention, but the health conditions of the workers are seldom reported. The liver and kidney functions of the workers were studied by comparing the blood indicators of the worker group with those of the control group. Moreover, factors affecting the liver and kidney functions, such as the sexuality, age, and working time, were identified using correlation analysis.
View Article and Find Full Text PDFGasification has gained advantage as an effective way to dispose domestic solid waste in mountainous rural of China. However, its toxic emissions such as PCDD/Fs and heavy metals, as well as their potential environmental risks, were not well studied in engineering application. In this study, an updraft fixed bed gasifier was investigated by field sampling analysis.
View Article and Find Full Text PDFThis paper analyzed 17 polychlorinated dibenzo--dioxins and dibenzofurans(PCDD/Fs) by HRGC/HRMS in the flue gas of a certain municipal solid waste incinerator(MSWI) and its surrounding air and other possible sources in Guangdong. It discussed the feature of homologs and main toxic monomers in all samples. It also investigated the relationship among surrounding area, MSWI and possible sources using principle component analysis (PCA) and cluster analysis.
View Article and Find Full Text PDFHuan Jing Ke Xue
December 2015
In order to investigate the internal exposure levels of polycyclic aromatic hydrocarbons (PAHs) in primary school students of Guangzhou, the research collected urine of 78 and 86 primary school students from two primary schools in the summer of 2014, one school located in the ordinary residential area and the other in the industrial area. The contents of 10 kinds of OH-PAHs were tested by the rapid liquid chromatography coupled to triple quadruple tandem mass spectrometry. The results showed that the concentrations of total OH-PAHs in primary school students in the residential zone ranged from 0.
View Article and Find Full Text PDFHigh-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) was used to measure contents of 2, 3, 7, 8-polychlorinated dibenzo-p-dioxin and furan (PCDD/F) in ambient air in Guangzhou city, and its sources were traced and tracked preliminarily. Spatial and seasonal distributions, the correlation between PCDD/F concentrations and various kinds of meteorological factors were studied with emphasis, as well as the trajectory of air mass simulated by hybrid single-particle lagrangian integrated trajectory (HYSPLIT) model of the U. S.
View Article and Find Full Text PDFConcentrations and distribution characteristics of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (2,3,7,8-PCDD/Fs) were analyzed in waste water from a paper mill. And concentrations of 2,3,7,8-PCDD/Fs in waste water before and after electron beam irradiation with different doses were compared. The feasibility, mechanism and rates of 2,3,7,8-PCDD/Fs degradation were discussed.
View Article and Find Full Text PDFThe CALPUFF model was applied to simulate the ground-level atmospheric concentrations of Pb and Cd from municipal solid waste incineration (MSWI) plants, and the soil concentration model was used to estimate soil concentration increments after atmospheric deposition based on Monte Carlo simulation, then ecological risk assessment was conducted by the potential ecological risk index method. The results showed that the largest atmospheric concentrations of Pb and Cd were 5.59 x 109-3) microg x m(-3) and 5.
View Article and Find Full Text PDFAtmospheric concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured seasonally in an industrial area of Guangzhou City. And seasonal variation of concentrations and distribution characteristics of 2,3,7,8- PCDD/Fs was investigated. The PCDD/Fs concentrations and corresponding I-TEQ (toxic equivalent quantity) values were in the range of 2.
View Article and Find Full Text PDFHuman hair has been widely used as a bioindicator for human persistent organic pollutants (POPs) exposure, but studies on the sources of hair POPs and the relationship between hair and body burden are limited. This study analyzed the possible source apportionment of hair PBDEs and examined the relationship between PBDE concentrations in paired hair and serum from e-waste recycling workers. Using the ratio of BDE 99/47 and BDE 209/207 as indices, we calculated that only 15% of the highly brominated congeners (nona- and deca-BDE congeners) comes from exogenous (external) exposure for both female and male hair, but an average of 64% and 55% of the lower-brominated congeners (tetra- to penta-BDE congeners) come from exogenous exposure for female and male hair, respectively.
View Article and Find Full Text PDFThe concentration and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the environmental air, soil and plant samples around a hospital solid waste incinerator (HSWI) in Northwest of China were determined by HRGC/HRMS, and the flue gas samples of the HSWI were also involved. The results showed that the average concentration (I-TEQ) of PCDD/Fs in the exhaust gas was 184 ng x m(-3), which seriously exceeds the emission standard (0.5 ng x m(-3)).
View Article and Find Full Text PDFRadiation pneumonitis (RP) is an important dose-limiting toxicity during thoracic radiotherapy. Previous investigations have shown that curcumin is used for the treatment of inflammatory conditions and cancer, suggesting that curcumin may prevent RP and sensitize cancer cells to irradiation. However, the clinical advancement of curcumin is limited by its poor water solubility and low bioavailability after oral administration.
View Article and Find Full Text PDFPurpose: Bcl2/adenovirus EIB 19 kDa-interacting protein 3 (BNIP3) is a proapoptotic member of the Bcl-2 family. To address its potential as a therapeutic target for radiosensitization, this study investigated the effect of Bnip3 expression on radiosensitivity of cervical cancer in vitro and in vivo.
Materials And Methods: In vitro: A plasmid expressing the BNIP3 gene was transfected into human cervical cancer HeLa cells using Lipofectamine(2000), and western blot and immunohistochemistry analysis were performed to evaluate the expression of BNIP3 in transfected cells.
Sichuan Da Xue Xue Bao Yi Xue Ban
November 2010
Objective: To study the volumetric and geometric changes of parotids occurring during IMRT treatment for NPC.
Methods: The pre-treatment CBCT images of 10 patients were obtained using kV-CBCT and transmitted back to TPS. The gross tumor volumes (GTVs) and volumes of parotids were manually drawn slice by slice on the CBCT images by the same person using image analysis software system Tomcon 3.
Sichuan Da Xue Xue Bao Yi Xue Ban
November 2010
Objective: To explore whether demethylation inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) could reverse multidrug resistance (MDR) of human colon cancer and its impacts on the expressions of Bcl-2/adenovirus E1B 19 KDa protein interacting protein 3 (BNIP3), P-glycoprotein (P-GP) and multidrug resistance-associated protein (MRP), as well as the activity of DNA methyltransferase (DNMT).
Methods: Oxaliplatin (L-OHP) resistant human colon carcinoma cells (sw620/L-OHP) and its parental cells (sw620) were used to determine the effect of 5-aza-dC. CCK-8 assay was adopted to evaluate the cytotoxicity of 5-aza-dC.
In the present study, 16 polycyclic aromatic hydrocarbons (PAHs) in the surface sediment from Beijiang River in China were quantitatively determined by GC/MS. The concentration of PAHs varied from 38.2 to 6470 ng x g(-1) dry weight, with average 1071 ng x g(-1), which was in moderate level compared with other rivers in Pear River Basin.
View Article and Find Full Text PDFBackground & Objective: Both interfractional and intrafractional setup errors may affect the precision of radiotherapy. This study was to analyze the interfractional and intrafractional setup errors in radiotherapy for tumors using cone-beam computed tomography(CBCT).
Methods: Of the 51 patients received radiotherapy, 19 had head and neck tumors, 25 had thoracic tumors, and seven had abdominal-pelvic tumors.
Background & Objective: The intensity-modulated radiotherapy (IMRT) with its highly conformed dose distribution to nasopharyngeal cancer (NPC) and the surrounding critical organs is being accepted increasingly in clinical practice. Due to the steep dose fall-offs of IMRT at the target margin, precise patient positioning and verification are required. This study was to evaluate the role of kilo-volt cone-beam computed tomography (kV-CBCT) in guiding the accurate positioning of IMRT for NPC.
View Article and Find Full Text PDFZhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
May 2005