Objectives: To study the association between metals mixture exposure and DNA oxidative damage using mixture analysis methods, and to explore the most significant exposure factors that cause DNA oxidative damage. Methods: Workers from steel enterprises were recruited in Shandong Province. Urinary metals were measured by using the inductively coupled plasma mass spectrometry method. The level of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was determined by using the ultra-high performance liquid chromatography-mass spectrometry method. Bayesian kernel machine regression (BKMR), elastic net regression and quantile g-computation regression were used to analyze the association between urinary metals and urinary 8-OHdG. Results: A total of 768 subjects aged (36.15±7.40) years old were included in the study. BKMR, elastic net regression and quantile g-computation all revealed an overall positive association between the mixture concentration and increased urinary 8-OHdG. The quantile g-computation results showed that with a 25% increase in metal mixtures, the urinary 8-OHdG level increased by 77.60%. The elastic net regression showed that with a 25% increase in exposure risk score, the urinary 8-OHdG level increased by 26%. The BKMR summarized the contribution of individual exposures to the response, and selenium, zinc, and nickel were significant contributors to the urinary 8-OHdG elevation. Conclusion: Exposure to mixed metals causes elevated levels of DNA oxidative damage, and selenium, zinc, and nickel are significant exposure factors.
Humans ; Adult ; Nickel/toxicity* ; Selenium ; Bayes Theorem ; Metals/toxicity* ; 8-Hydroxy-2'-Deoxyguanosine ; Oxidative Stress/physiology* ; Zinc ; DNA Damage

The purpose of this study was to investigate the NOAEL of the nickel ion and provide with basic data for the biological evaluation of those medical devices containing nickel. Five groups SD rats were repeatedly exposed during 14 d respectively to nickel at first stage doses of 4.9, 3.7, 2.5 mg/(kg.d), and the second stage doses of 1.2, 0.25 mg/(kg.d) by the intravenous route. The results showed that the NOAEL of nickel ion is 0.25 mg/(kg.d) for SD rats, and the result was verified by subchronic systemic toxicity test of nickel alloy. The threshold of toxicological concern (TTC) of nickel is 150 μg/d (based on application of 100-fold uncertainty factor and a body weight of 60 kg)deduced by these data.
Animals ; Equipment and Supplies/adverse effects* ; Nickel/toxicity* ; No-Observed-Adverse-Effect Level ; Rats ; Rats, Sprague-Dawley ; Risk Assessment

OBJECTIVEStudying different concentrations of nickel smelting smoke subjects of human lung adenocarcinoma cells (A549) carcinogenic effects, discusses the influence of L-ascorbic acid protection.

METHODSThe A549 cells were divided into experimental and L-ascorbic acid in the intervention group. Plus exposure group concentration of nickel refining dusts were formulated 0.00, 6.25, 12.50, 25.00, 50.00, 100.00 µg/ml suspension, the intervention group on the basis of the added exposure group containing L-ascorbic acid (100 mmol/L), contact 24 h. Detection of cell viability by MTT assay. When the test substance concentration select 0.00, 25.00, 50.00, 100.00 µg/ml experiment for internal Flou-3 fluorescent probe to detect cell Ca²⁺ concentration, within DCFH-DA detect intracellular reactive oxygen (ROS) content, real-time quantitative PCR (real time, in the RT-PCR) was used to detect cell HIF-1α gene expression.

RESULTSWith the increase of concentration, subjects increased cell growth inhibition rate, intracellular Ca²⁺ concentration increases, ROS content increased, HIF-1α gene expression increased, differences were statistically significant (P < 0.05). After L-ascorbic acid intervention treatment, the results of the intervention group were lower than that of the experimental group, and the difference was statistically significant (P < 0.05), so L-ascorbic acid can effectively protect the nickel exposure damage to cells.

CONCLUSIONWith subjects following exposure to nickel concentration increased, its effect on A549 cell damage increases, L-ascorbic acid cell damage caused by nickel has certain protective effect.

Adenocarcinoma ; Ascorbic Acid ; chemistry ; Calcium ; metabolism ; Cell Line, Tumor ; Cell Survival ; Culture Media ; chemistry ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Lung Neoplasms ; Metallurgy ; Nickel ; toxicity ; Occupational Exposure ; Protective Agents ; chemistry ; Reactive Oxygen Species ; metabolism ; Smoke

Our study explored the dynamic changes in and the relationship between the DNA damage marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the DNA repair marker 8-hydroxyguanine DNA glycosidase 1 (hOGG1) according to the length of occupational employment in nickel smelting workers. One hundred forty nickel-exposed smelting workers and 140 age-matched unexposed office workers were selected from the Jinchang cohort. The 8-OHdG levels in smelting workers was significantly higher than in office workers (Z=-8.688, P<0.05) and the 8-OHdG levels among nickel smelting workers in the 10-14 y employment length category was significantly higher than among all peers. The hOGG1 levels among smelting workers were significantly lower than those of non-exposed workers (Z=-8.948, P<0.05). There were significant differences between employment length and hOGG1 levels, with subjects employed in nickel smelting for 10-14 y showing the highest levels of hOGG1. Correlation analysis showed positive correlations between 8-OHdG and hOGG1 levels (r=0.413; P<0.01). DNA damage was increased with employment length among nickel smelting workers and was related to the inhibition of hOGG1 repair capacity.
Biomarkers ; Case-Control Studies ; Cohort Studies ; DNA Damage ; drug effects ; DNA Glycosylases ; blood ; DNA Repair ; Deoxyadenosines ; blood ; Humans ; Male ; Metallurgy ; Nickel ; toxicity ; urine ; Occupational Exposure ; adverse effects ; Time Factors

The purpose of this study was to investigate the cytotoxicity of the nickel ion and provide with basic data for the biological evaluation of those medical devices containing nickel. Seven cell lines were chosen. They were L929, h9c2(2-1), 293[HEK-293], hFOB1.19, THLE-3, H9 and IM-9 respectively. According to the principle of biological evaluation of medical devices, MTT method was chosen to test the cytotoxicity in different concentrations of nickel ion. For each cell line, the relative growth rate (RGR) was obtained and the cytotoxic grade was classified. Besides, IC50 values were calculated. As a result, it was found that the sensitivity was different among all cell lines. H9 was the most sensitive one, while the L929 was the most tolerant one. The concentration which is not above 1.25 mg/L was safe for all seven cell lines, because the cytotoxicity for all cells exposed in this concentration were not higher than grade 1. According to the criteria for medical devices, the concentrations not above 5 mg/L were safe for L929 cells. This result helps us to roughly assess the cytotoxicity and systematic toxicity caused by nickel contained in medical devices.
Cell Line ; Equipment and Supplies ; HEK293 Cells ; Humans ; Ions ; toxicity ; Nickel ; toxicity

OBJECTIVETo investigate the effect of nickel-smelting fumes on the expression of bcl-2 and bax in mammalian cells.

METHODSLogarithmic growth NIH/3T3 cells were exposed to venom for 24 h, which sample fumes concentration was respectively 0, 6.25, 12.50, 25.00, 50.00, 100.00 µg/ml. Cell viability was assessed by MTT assay and the level of extracellular LDH activity was detected with Lactate Dehydrogenase (LDH) kit. Morphological changes of apoptotic were observed with Hoechst33342, while Western blot was used to measure the expression of bcl-2 and bax.

RESULTSIn addition to 7 days of 6.25 µg/ml nickel-smelting fumes group, each time point and dose group's cell viability reduced with significant differences compared with the control group (P < 0.05). the extracellular LDH activity increased with increasing dose of nickel-smelting fumes, and the extracellular LDH activity of 6.25, 12.50, 25.00, 50.00, 100.00 µg/ml nickel-smelting fumes group increased as compared with the control group (P < 0.05). Simultaneously, the cells, treated with 100.00 µg/ml nickel-smelting fumes for 24 h, appeared obvious morphological changes of apoptosis, such as chromatin condensation and cell shrinkage. the expression of bcl-2 significantly increased in groups of 6.25, 12.50, 25.00 µg/ml nickel-smelting fumes (0.58 ± 0.01, 0.6 3± 0.01 and 0.57 ± 0.01) and decreased in groups of 50.00, 100.00 µg/m nickel-smelting fume (0.35 ± 0.01 and 0.27 ± 0.01) as compared with that of the control group (P < 0.05). And the expression of bax significantly decreased in group of 6.25 µg/ml nickel-smelting fumes (0.58 ± 0.00) and increased in groups of 50.00, 100.00 µg/m nickel-smelting fumes (0.71 ± 0.01 and 0.78 ± 0.02) as compared with that of the control group (P < 0.05).

CONCLUSIONApoptosis was activated in NIH/3T3 cell after 24 h of exposure to Ni-smelting fumes, which may be induced by oxidative stress.

Air Pollutants ; toxicity ; Animals ; Apoptosis ; drug effects ; Cell Survival ; drug effects ; L-Lactate Dehydrogenase ; Mice ; NIH 3T3 Cells ; drug effects ; Nickel ; toxicity ; Oxidative Stress ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2-Associated X Protein ; metabolism

China ; epidemiology ; Cohort Studies ; Female ; Humans ; Lung Neoplasms ; epidemiology ; mortality ; Male ; Metallurgy ; Nickel ; toxicity ; Occupational Exposure ; adverse effects ; Pulmonary Heart Disease ; epidemiology ; mortality ; Retrospective Studies ; Silicosis ; epidemiology ; mortality

There are more than 50 000 workers in Jinchuan Group Co, Ltd (JNMC). Since all staff in JNMC are eligible for a medical examination every two years, only 23 484 nickel-exposed subjects who participated in medical examination were included in this study. Their data, collected from June 22, 2011 to September 28, 2012, in a comprehensive epidemiological survey and during medical examinations, permitted an extensive evaluation of the relation between metal exposure, gene, epigenetics and risk of human diseases. Their lifestyle investigation showed that the overall prevalence of current smokers, alcohol drinkers, and tea drinkers was 39.1%, 19.7%, and 55.2%, respectively. The prevalence of hypertension, allergic rhinitis and cholecystitis , the top 3 prevalent diseases, was 11.7%, 11.0%, and 8.9%, respectively.
Adult ; Aged ; Alcohol Drinking ; epidemiology ; Biomarkers, Tumor ; analysis ; China ; epidemiology ; Cholecystitis ; epidemiology ; Cohort Studies ; Female ; Humans ; Hypertension ; epidemiology ; etiology ; Life Style ; Male ; Middle Aged ; Neoplasms ; epidemiology ; etiology ; mortality ; Nickel ; toxicity ; Occupational Exposure ; statistics & numerical data ; Rhinitis, Allergic ; Rhinitis, Allergic, Perennial ; epidemiology ; Smoking ; epidemiology ; Young Adult

OBJECTIVETo investigate the cytotoxicity and oxidative damage on NIH/3T3 cells induced by nickel smelting fume.

METHODSNIH/3T3 cells were treated with nickel smelting fume collected from a nickel smelting factory in China with doses of 0, 6.25, 12.50, 25.00, 50.00, and 100.00 µg/ml for 6 h. Dose-dependent cytotoxicity in cells were assessed by Cell Counting Kit-8 (CCK-8), natural red uptake assay, and lactate dehydrogenase (LDH) leakage assay, and the level of oxidative damage was assessed based on the activity of catalase (CAT), percentage inhibition of superoxide dismutase (SOD), and content of malonaldehyde (MDA).

RESULTSThe relative survival of NIH/3T3 cells decreased with the increase in the dose of nickel smelting fume. In the CCK-8 assay, the group with 100 µg/ml nickel smelting fume showed a cell growth inhibition rate of 86%, with a significant difference compared with the control group (P < 0.05). LDH activity increased with increasing dose of nickel smelting fume: the groups of 12.50, 25, 50, and 100 µg/ml nickel smelting fume all showed increased LDH activities as compared with the control group (P < 0.05). The activities of CAT were significantly reduced in groups of 25, 50, and 100 µg/ml nickel smelting fume as compared with that of the control group (P < 0.05). As the dose of nickel smelting fume increased, the percentage inhibition of SOD and the content of MDA increased, with significant differences compared with the control group (P < 0.05).

CONCLUSIONOxidative damage may be induced in NIH/3T3 cells after 6 h of exposure to nickel smelting fume, which leads to cell death.

Animals ; Catalase ; metabolism ; Cell Death ; drug effects ; Dust ; L-Lactate Dehydrogenase ; metabolism ; Malondialdehyde ; metabolism ; Metallurgy ; Mice ; NIH 3T3 Cells ; Nickel ; toxicity ; Oxidative Stress ; drug effects ; Superoxide Dismutase ; metabolism

OBJECTIVETo determine the effects of water hardness on the toxicities of cobalt (Co) and nickel (Ni) to a freshwater fish, Capoeta fusca.

METHODSToxicity was investigated by static bioassay. Fish were exposed to cobalt (as CoCl(2)) and nickel (as NiCl(2)) for 96 h in waters with two levels of hardness ("hard" and "very hard", nominally 130 mg/L and 350 mg/L as CaCO(3), respectively).

RESULTSWater hardness had a significant effect on the acute toxicity of both elements. The 96 h LC(50) values for Co were 91.7 mg/L and 204.8 mg/L in hard and very hard waters, respectively, and for Ni the 96 h LC(50) values were 78.0 mg/L and 127.2 mg/L, respectively.

CONCLUSIONThe fish were more sensitive to Co and Ni toxicity in hard water than in very hard water; very hard water protects C. fusca against the toxicity of Co and Ni.

Animals ; Calcium Carbonate ; analysis ; Cobalt ; analysis ; toxicity ; Cyprinidae ; growth & development ; Environmental Monitoring ; Fresh Water ; analysis ; Iran ; Lethal Dose 50 ; Nickel ; analysis ; toxicity ; Toxicity Tests, Acute ; Water Pollutants, Chemical ; analysis ; toxicity