Objective: To explore the changes of γ-GCS mRNA expression and GSH-PX in serum of workers exposed to manganese in order to provide scientific basis for early diagnosis of manganese poisoning. Methods: In June 2017, a total of 180 workers from a motorcycle manufacturer were selected by stratified random sampling, including 115 welders as the exposure group and 65 administrative office workers as the Control Group, the exposure group was divided into high exposure group (43 persons) and low exposure group (72 persons) according to whether the exposure group exceeded the standard limit. The levels of γ-gcs Mrna expression and GSH-Px activity in serum were determined by Occupational Health Survey, and the differences of γ-gcs Mrna expression and GSH-Px activity among different groups were analyzed. Results: Compared with the control group, the serum GSH-Px activity was lower and the serum γ-GCS mRNA expression level was higher in the exposed group (F=370.52, 275.95, P<0.01) . Compared with the control group, there was significant difference in γ-GCS mRNA expression level and GSH-Px activity (F=0.475、1.06, P<0.01; F=48.53、111.70, P<0.01) . The concentrations of manganese in air, welding dust and urine were positively correlated with the level of γ-GCS mRNA (r=0.71, 0.50, 0.31, P<0.01) The serum GSH-Px activity was negatively correlated with the concentrations of manganese in air, welding dust and urine (r=-0.80, -0.52, -0.30, P< 0.01) , There was no correlation between Serum γ-GSH-Px activity and age and years of exposure (P>0.05) . Conclusion: Serum γ-GCS mRNA expression level and GSH-Px activity level can be used as early biomarkers of manganese poisoning. The concentrations of manganese in workplace air, welding dust and urine manganese in workers are the influencing factors.
Air Pollutants, Occupational ; Dust ; Humans ; Ions ; Manganese ; Manganese Poisoning ; Occupational Exposure/analysis* ; RNA, Messenger/genetics* ; Welding

PURPOSE: The purpose of this study was to investigate the corrosion behaviors of dental implant alloy after micro-sized surface modification in electrolytes containing Mn ion. MATERIALS AND METHODS: Mn-TiO₂ coatings were prepared on the Ti-6Al-4V alloy for dental implants using a plasma electrolytic oxidation (PEO) method carried out in electrolytes containing different concentrations of Mn, namely, 0%, 5%, and 20%. Potentiodynamic method was employed to examine the corrosion behaviors, and the alternating-current (AC) impedance behaviors were examined in 0.9% NaCl solution at 36.5℃±1.0℃ using a potentiostat and an electrochemical impedance spectroscope. The potentiodynamic test was performed with a scanning rate of 1.667 mV s⁻¹ from −1,500 to 2,000 mV. A frequency range of 10⁻¹ to 10⁵ Hz was used for the electrochemical impedance spectroscopy (EIS) measurements. The amplitude of the AC signal was 10 mV, and 5 points per decade were used. The morphology and structure of the samples were examined using field-emission scanning electron microscopy and thin-film X-ray diffraction. The elemental analysis was performed using energy-dispersive X-ray spectroscopy. RESULT: The PEO-treated surface exhibited an irregular pore shape, and the pore size and number of the pores increased with an increase in the Mn concentration. For the PEO-treated surface, a higher corrosion current density (I(corr)) and a lower corrosion potential (E(corr)) was obtained as compared to that of the bulk surface. However, the current density in the passive regions (I(pass)) was found to be more stable for the PEO-treated surface than that of the bulk surface. As the Mn concentration increased, the capacitance values of the outer porous layer and the barrier layer decreased, and the polarization resistance of the barrier layers increased. In the case of the Mn/Ca-P coatings, the corroded surface was found to be covered with corrosion products. CONCLUSION: It is confirmed that corrosion resistance and polarization resistance of PEO-treated alloy increased as Mn content increased, and PEO-treated surface showed lower current density in the passive region.
Alloys ; Corrosion ; Dental Implants ; Dielectric Spectroscopy ; Electric Impedance ; Electrolytes ; Manganese ; Methods ; Microscopy, Electron, Scanning ; Plasma ; Spectrum Analysis ; X-Ray Diffraction

BACKGROUND/OBJECTIVES: This study was performed to measure fat-soluble vitamins and minerals in breast milk of Korean lactating mothers who exclusively breastfed their babies. SUBJECTS/METHODS: Breast milk samples were collected from 334 mothers. Concentrations of retinol and α-tocopherol were analyzed by high performance liquid chromatography ultraviolet spectrometry while concentrations of minerals were measured by inductively coupled plasma optical emission spectrometry. RESULTS: Retinol and α-tocopherol contents of breast milk were 39.58 ± 19.64 µg/dL and 0.23 ± 0.13 mg/dL, respectively. Average sodium, potassium, calcium, phosphorus, and magnesium levels in breast milk were 11.11 ± 5.16, 38.56 ± 9.01, 27.87 ± 6.10, 13.56 ± 3.30, and 3.05 ± 0.65 mg/dL, respectively. Contents of trace elements such as iron, zinc, copper, and manganese were 40.26 ± 46.21, 98.40 ± 62.47, 24.09 ± 9.03, and 0.90 ± 1.63 µg/dL, respectively. Fat-soluble vitamin concentration was positively correlated with total fat in milk samples, but no significant differences were observed in levels of retinol, α-tocopherol, or minerals based on whether or not lactating women were taking dietary supplements. CONCLUSIONS: Micronutrient contents of breast milk samples from Korean lactating women were comparable to those of other nations. Retinol and α-tocopherol levels were correlated and also with total fat in breast milk.
Breast* ; Calcium ; Chromatography, Liquid ; Copper ; Dietary Supplements ; Fats ; Female ; Humans ; Infant* ; Iron ; Korea* ; Magnesium ; Manganese ; Micronutrients ; Milk ; Milk, Human* ; Minerals* ; Miners* ; Mothers ; Phosphorus ; Plasma ; Potassium ; Sodium ; Spectrum Analysis ; Trace Elements ; Vitamin A* ; Vitamins ; Zinc

The transplants of one-year-old Glycyrrhiza uralensis Fisch. were subjected to five concentrations of MnSO4-H2O (0, 1.81, 18.1, 36.2 and 54.3 mg·L(-1)) culturing in vermiculite. qRT-PCR and HPLC were respectively used to measure the relative expression of SQS1 gene and the content of glycyrrhizic acid of G. uralensis in different concentrations of MnSO4·H2O. This is to explore discuss the effects of the expression of SQS1 gene and the accumulation of glycyrrhizic acid by Mn treatment. The results showed both the expression of SQS1 gene and the content of glycyrrhzic acid of G. uralensis tended to rise after the fall of the first with the increase of concentration of Mn treatment. And they were of very significant positive correlation (P<0.01, r=0.737). Relative expression of SQS1 gene reached the highest 7.90 under 18.1 mg·L(-1) MnSO4·H2O treatment. It was very significantly different between 18.1 mg·L(-1) concentration of MnSO4·H2O treatment and CK (0 mg·L(-1)), 1.81, 36.2 and 54.3 mg·L(-1) (P<0.01), and 1.75, 1.37, 1.37, 2.33 times respectively. The content of glycyrrhizic acid reached the highest under 1.81 and 18.1 mg·L(-1) MnSO4·H2O treatment, and there were not significant difference (P>0.05). It was very significantly different between them and other concentrations of MnSO4·H2O treatment (P<0.01). This study suggests the appropriate concentration of Mn treatment could certain promote the expression of SQS1 gene and the accumulation of glycyrrhizic acid of G. uralensis.
Chromatography, High Pressure Liquid ; Genes, Plant ; Glycyrrhiza uralensis ; chemistry ; genetics ; Glycyrrhizic Acid ; analysis ; Manganese

OBJECTIVETo understand the toxic effects of manganese exposure on health by measurement of manganese concentration and occupational health inspection among workers in an enterprise exposed to manganese, and to provide a basis for occupational disease control.

METHODSThe air concentrations of manganese in 12 workplaces where workers often stayed were measured by typical sampling; occupational health inspection was performed among a total of 538 workers in the enterprise by cluster sampling.

RESULTSThe average concentrations of manganese in the workplace from 2011 to 2013 were 0.179 mg/m(3), 0.122 mg/m(3), and 0.082 5 mg/m(3), respectively, indicating a significant decrease in manganese level within the three years by rank-sum test (P < 0.05). The results of health inspection showed that 165 (30.7%) out of 538 workers had abnormal indices, and the incidence of autonomic nervous system abnormalities reached 32.7% (176/538). There was no correlation between manganese concentration in the workplace and the incidence of abnormal indices in health inspection, while the manganese concentration in the workplace was positively correlated with the incidence of autonomic nervous system symptoms (r = 0.718, P < 0.05).

CONCLUSIONThe manganese concentration in the workplace is positively correlated with the incidence of autonomic nervous system symptoms. Early exposure to a low level of manganese can induce functional changes and potential damages in the nervous system.

Humans ; Incidence ; Manganese ; analysis ; Nervous System ; drug effects ; physiopathology ; Occupational Diseases ; chemically induced ; epidemiology ; Occupational Exposure ; analysis ; Occupational Health ; standards ; Workplace

OBJECTIVES: The aim of this study was to evaluate the cytotoxicity, setting time and compressive strength of MTA and two novel tricalcium silicate-based endodontic materials, Bioaggregate (BA) and Biodentine (BD). MATERIALS AND METHODS: Cytotoxicity was evaluated by using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide (XTT) assay. Measurements of 9 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) were performed by inductively coupled plasma-mass spectrometry (ICP-MS) of leachates obtained by soaking the materials in distilled water. Setting time and compressive strength tests were performed following ISO requirements. RESULTS: BA had comparable cell viability to MTA, whereas the cell viability of BD was significantly lower than that of MTA. The ICP-MS analysis revealed that BD released significantly higher amount of 5 heavy metals (arsenic, copper, iron, manganese, and zinc) than MTA and BA. The setting time of BD was significantly shorter than that of MTA and BA, and the compressive strength of BA was significantly lower than that of MTA and BD. CONCLUSIONS: BA and BD were biocompatible, and they did not show any cytotoxic effects on human periodontal ligament fibroblasts. BA showed comparable cytotoxicity to MTA but inferior physical properties. BD had somewhat higher cytotoxicity but superior physical properties than MTA.
Cadmium ; Cell Survival ; Chromium ; Compressive Strength ; Copper ; Fibroblasts ; Humans ; Iron ; Manganese ; Metals, Heavy ; Nickel ; Periodontal Ligament ; Spectrum Analysis ; Water ; Pemetrexed

We measured selenium, zinc, copper and manganese concentrations in the human milk of Korean mothers who gave birth to preterm infants, and compared these measurements with the recommended daily intakes. The samples of human milk were collected postpartum at week-1, -2, -4, -6, -8, and -12, from 67 mothers who gave birth to preterm infants (< 34 weeks, or birth weight < 1.8 kg). All samples were analyzed using atomic absorption spectrophotometry. The concentrations of selenium were 11.8 +/- 0.5, 11.4 +/- 0.8, 12.7 +/- 0.9, 11.4 +/- 0.8, 10.8 +/- 0.9, and 10.5 +/- 1.3 microg/L, zinc were 7.8 +/- 0.5, 9.1 +/- 0.8, 7.2 +/- 0.9, 8.0 +/- 0.8, 7.4 +/- 0.9, and 6.6 +/- 1.2 mg/L, copper were 506 +/- 23.6, 489 +/- 29.4, 384 +/- 33.6, 356 +/- 32.9, 303 +/- 35.0, and 301 +/- 48.0 microg/L and manganese were 133 +/- 4.0, 127 +/- 6.0, 125 +/- 6.0, 123 +/- 6.0, 127 +/- 6.0, and 108 +/- 9.0 microg/L at week-1, -2, -4, -6, -8, and -12, respectively. The concentrations of selenium and zinc meet the daily requirements but that of copper is low and of manganese exceeds daily requirements recommended by the American Academy of Pediatrics, Committee on Nutrition.
Adult ; Copper/analysis ; Female ; Humans ; Infant, Newborn ; Infant, Premature ; Longitudinal Studies ; Manganese/analysis ; Milk, Human/*chemistry ; Postpartum Period ; Republic of Korea ; Selenium/analysis ; *Spectrophotometry, Atomic ; Trace Elements/*analysis ; Zinc/analysis

OBJECTIVE: To establish a new method to estimate injury-tool by analyzing the components of left metal particles from hammers impact on pig skin and filter paper using scanning electron microscope and energy dispersive X-ray spectrometer (SEM-EDX). METHODS: The pig skin and filter paper were stricken by two steel hammers. The left metal particles were examined by SEM-EDX and the results were statistically analyzed by SPSS 13.0. RESULTS: The characteristics of left particles showed stable by several impacts using one steel hammer. The left particles showed no statistical difference for impact on pig skin and filter paper. The left particles displayed a statistical difference using two hammer with different components. CONCLUSION SEM-EDX can be used to detect the left metal particles from the steel hammer and can provide a method for estimating injury-tool.
Animals ; Forensic Medicine/methods* ; Iron/analysis* ; Manganese/analysis* ; Metals/chemistry* ; Microscopy, Electron, Scanning/methods* ; Models, Animal ; Skin/injuries* ; Spectrometry, X-Ray Emission/methods* ; Swine ; Wounds, Nonpenetrating/pathology*

Little is known about hair mineral status in fibromyalgia patients. This study evaluated the characteristics of hair minerals in female patients with fibromyalgia compared with a healthy reference group. Forty-four female patients diagnosed with fibromyalgia according to the American College of Rheumatology criteria were enrolled as the case group. Age- and body mass index-matched data were obtained from 122 control subjects enrolled during visit for a regular health check-up. Hair minerals were analyzed and compared between the two groups. The mean age was 43.7 yr. General characteristics were not different between the two groups. Fibromyalgia patients showed a significantly lower level of calcium (775 microg/g vs 1,093 microg/g), magnesium (52 microg/g vs 72 microg/g), iron (5.9 microg/g vs 7.1 microg/g), copper (28.3 microg/g vs 40.2 microg/g) and manganese (140 ng/g vs 190 ng/g). Calcium, magnesium, iron, and manganese were loaded in the same factor using factor analysis; the mean of this factor was significantly lower in fibromyalgia group in multivariate analysis with adjustment for potential confounders. In conclusion, the concentrations of calcium, magnesium, iron, and manganese in the hair of female patients with fibromyalgia are lower than of controls, even after adjustment of potential confounders.
Adult ; Body Height ; Body Mass Index ; Calcium/analysis ; Female ; Fibromyalgia/*metabolism ; Hair/*chemistry ; Humans ; Iron/analysis ; Magnesium/analysis ; Manganese/analysis ; Metals/*analysis ; Middle Aged

We studied the hydrogen evolution (HE) of green alga Chlorella pyrenoidosa grown in normal (nutrients sufficient) media and nitrogen, manganese or sulfur deprived medium. The results showed that photo-hydrogen evolution could occur under all conditions herein before, but the efficiency of HE was maximum under nitrogen deprivation, and the total hydrogen yield was 88.613 microL H2/mg Chla, which was 4.61, 1.92, 3.63 times of control, manganese deprivation, sulfur deprivation groups, respectively. We also measured the growth, the photosynthesis and respiration of the alga. The data demonstrated that manganese deprivation had less influence than nitrogen and sulfur deprivation on the growth, the photosynthesis and respiration of C. pyrenoidosa. Compared with the normal (nutrients sufficient), manganese and sulfur deprivation inhibited the photosynthesis and growth of the alga while bringing small impact on respiration. Nitrogen deprivation, however, greatly restrained the photosynthesis and growth while enhancing the respiration. Those data provide clues for the further study on both the conditions optimization and mechanism of hydrogen evolution.
Chlorella ; growth & development ; metabolism ; Hydrogen ; analysis ; metabolism ; Manganese ; analysis ; metabolism ; Nitrogen ; analysis ; metabolism ; Photosynthesis ; Sulfur ; analysis ; metabolism