OBJECTIVES: The purpose of this study was to evaluate the exposure to arsenic in preventive maintenance (PM) engineers in a semiconductor industry by detecting speciated inorganic arsenic metabolites in the urine. METHODS: The exposed group included 8 PM engineers from the clean process area and 13 PM engineers from the ion implantation process area; the non-exposed group consisted of 14 office workers from another company who were not occupationally exposed to arsenic. A spot urine specimen was collected from each participant for the detection and measurement of speciated inorganic arsenic metabolites. Metabolites were separated by high performance liquid chromatography-inductively coupled plasma spectrometry-mass spectrometry. RESULTS: Urinary arsenic metabolite concentrations were 1.73 g/L, 0.76 g/L, 3.45 g/L, 43.65 g/L, and 51.32 g/L for trivalent arsenic (As3+), pentavalent arsenic (As5+), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), and total inorganic arsenic metabolites (As3+ + As5+ + MMA + DMA), respectively, in clean process PM engineers. In ion implantation process PM engineers, the concentrations were 1.74 g/L, 0.39 g/L, 3.08 g/L, 23.17 g/L, 28.92 g/L for As3+, As5+, MMA, DMA, and total inorganic arsenic metabolites, respectively. Levels of urinary As3+, As5+, MMA, and total inorganic arsenic metabolites in clean process PM engineers were significantly higher than that in the non-exposed group. Urinary As3+ and As5+ levels in ion implantation process PM engineers were significantly higher than that in non-exposed group. CONCLUSION: Levels of urinary arsenic metabolites in PM engineers from the clean process and ion implantation process areas were higher than that in office workers. For a complete assessment of arsenic exposure in the semiconductor industry, further studies are needed.
Arsenic* ; Cacodylic Acid ; Occupations ; Plants* ; Plasma ; Semiconductors* ; Spectrum Analysis

OBJECTIVES: The purpose of this study was to determine a separation method for each arsenic metabolite in urine by using a high performance liquid chromatography (HPLC)- inductively coupled plasma-mass spectrometer (ICP-MS). METHODS: Separation of the arsenic metabolites was conducted in urine by using a polymeric anion-exchange (Hamilton PRP X-100, 4.6 mm x 150 mm, 5 mum) column on Agilent Technologies 1260 Infinity LC system coupled to Agilent Technologies 7700 series ICP/MS equipment using argon as the plasma gas. RESULTS: All five important arsenic metabolites in urine were separated within 16 minutes in the order of arsenobetaine, arsenite, dimethylarsinate, monomethylarsonate and arsenate with detection limits ranging from 0.15 to 0.27 mug/L (40 muL injection). We used GEQUAS No. 52, the German external quality assessment scheme and standard reference material 2669, National Institute of Standard and Technology, to validate our analyses. CONCLUSIONS: The method for separation of arsenic metabolites in urine was established by using HPLC-ICP-MS. This method contributes to the evaluation of arsenic exposure, health effect assessment and other bio-monitoring studies for arsenic exposure in South Korea.
Argon ; Arsenic* ; Cacodylic Acid ; Chromatography, Liquid ; Environmental Monitoring ; Korea ; Limit of Detection ; Plasma ; Polymers ; Spectrum Analysis*

Changes in the testis interstitium from birth to adulthood were studied in New Zealand white rabbits of 1, 7, 21, 35, 49, 70, 105, 147, 196, and 252 days (n=8 per group) of age. Testes of rabbits were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 microm sections stained with methylene blueazure II, qualitative and quantitative (stereological) morphological studies were performed. Sperm production was measured by routine technique. The volume density of the interstitium represents 66.3% of the testicular parenchyma at day 1. Adult Leydig cells initially detected at day 7 (0.001%), increased progressively to reach a volume density of 2.6% by day 252. The absolute volume of mesenchymal cells, endothelial cells, pericytes, and myoid cells increased from birth to 252 days. The number of endothelial cells, pericytes, and myoid cells per testis increased gradually with age. The absolute numbers of adult Leydig cells and mesenchymal cells per testis increased linearly from birth to 252 days. The rate of production of adult Leydig cells was greater than that of mesenchymal cells in the postnatal rabbit testis through 252 days. The average volume of a mesenchymal cell increased from day 1 to day 70 and declined thereafter; the highest value was at day 70. Total sperm production and daily sperm production per testis increased significantly from 105 to 252 days of age. These results clarified the pattern of changes in the testis interstitium in rabbits from birth to adulthood and correlation these events with spermatogenesis.
Adult ; Cacodylic Acid ; Endothelial Cells ; Glutaral ; Humans ; Leydig Cells ; Male ; Parturition ; Perfusion ; Pericytes ; Rabbits ; Spermatogenesis ; Spermatozoa ; Testis

Changes in the testis interstitium from birth to adulthood were studied in New Zealand white rabbits of 1, 7, 21, 35, 49, 70, 105, 147, 196, and 252 days (n=8 per group) of age. Testes of rabbits were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 microm sections stained with methylene blueazure II, qualitative and quantitative (stereological) morphological studies were performed. Sperm production was measured by routine technique. The volume density of the interstitium represents 66.3% of the testicular parenchyma at day 1. Adult Leydig cells initially detected at day 7 (0.001%), increased progressively to reach a volume density of 2.6% by day 252. The absolute volume of mesenchymal cells, endothelial cells, pericytes, and myoid cells increased from birth to 252 days. The number of endothelial cells, pericytes, and myoid cells per testis increased gradually with age. The absolute numbers of adult Leydig cells and mesenchymal cells per testis increased linearly from birth to 252 days. The rate of production of adult Leydig cells was greater than that of mesenchymal cells in the postnatal rabbit testis through 252 days. The average volume of a mesenchymal cell increased from day 1 to day 70 and declined thereafter; the highest value was at day 70. Total sperm production and daily sperm production per testis increased significantly from 105 to 252 days of age. These results clarified the pattern of changes in the testis interstitium in rabbits from birth to adulthood and correlation these events with spermatogenesis.
Adult ; Cacodylic Acid ; Endothelial Cells ; Glutaral ; Humans ; Leydig Cells ; Male ; Parturition ; Perfusion ; Pericytes ; Rabbits ; Spermatogenesis ; Spermatozoa ; Testis

The present study was conducted to investigate the influence of hemicastration and age at hemicastraion on the subsequent Leydig cell morphology and function of male rats. Sprague Dawley rats were left intact or hemicastrated at 20, 30, 40, 50, or 60 days of age (n=18 rats per group). At 100 days of age, all rats were sacrificed. Testes were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using 1 micrometer sections stained with methylene blue, qualitative and quantitative morphological studies were performed. Testis incubations were used to determine lutenizing hormone (LH; 100 ng/mL) stimulated testosterone secretory capacity per testis in vitro. Testosterone levels in the incubation medium, and testosterone and LH levels in serum of these six groups of rats were determined by radioimmunoassay. Body and testis weights were not changed by hemicastration between experimental and control groups. Volume density of seminiferous tubules, interstitium, and Leydig cells was not significantly affected by hemicastration. Absolute volume of seminiferous and interstitium was significantly increased in unilaterally castrated rats at 20, 30 and 40 days of age compared to control. Significant increases in the total number of Leydig cells per testis occurred in rats hemicastrated at 20, 30, 40 and 50 days of age compared to control. A significant increase in average volume of a Leydig cell was noted in the hemicastrated rats at 30 and 40 days compared to intact rats of the same age but was significantly decreased at 60 days of age. Serum testosterone levels and LH-stimulated testosterone production per testis were significantly (P<0.05) increased in the hemicastrated rats at 30 and 40 days. In summary, when rats were unilaterally castrated at 20, 30, 40, 50, and 60 days of age, those rats hemicastrated at 30 and 40 days showed compensatory hypertrophy/hypersecretion of Leydig cells when killed at 100 days of age. Especially, these data suggested that compensatory hypertrophy/hypersecretion of Leydig cells in rats hemicastrated around the time of puberty occurs in the remaining testis.
Animals ; Cacodylic Acid ; Glutaral ; Humans ; Leydig Cells ; Male ; Methylene Blue ; Perfusion ; Puberty ; Radioimmunoassay ; Rats ; Rats, Sprague-Dawley ; Seminiferous Tubules ; Testis ; Testosterone ; Weights and Measures

Although the autogenous vein graft is the most reliable in the fields of microvascular reconstruction, the microvascular allograft and microvascular prosthesis have been developed to be substitute for autogenous vein because it has many problems. In many experimental study have been reported highly variable patency rate and its thrombogenetic property of microvascular allograft. Especially, antigenicity of the homogenous vessels and immune reaction-induced thrombosis are main cause of homogenous microvascular anastomosis failure. For that reason, several investigators have attempted to reduce the antigenicity and improve the patency rate of microvascular allograft. The purpose of this study was to observe the healing process in applying frozen arterial allograft in the rats. In order to perform this study, 27 Sprague-Dawley rats, weighing 300gm or more selected. 12 carotid arterial anastomoses were performed in the rats by using microvascular end-to-end anastomosis as control group and 15 frozen(-196degreesC) arterial allografts were implanted into the carotid artery in the rats by using microvascular anastomosis as experimental group. The experimental rats were sacrificed on the 1st, 3rd, 7th, 14th, 28th, 56th day after operations. For scanning electron microscopic study, fixation was performed by perfusion of 2.5% glutaraldehyed-2% paraformaldehyed in 0.1M phosphate buffer at pH7.3. The specimens were post-fixated in 1% osmium tetraoxide for 2 hours, washed with cacodylate buffer, dehydrated in a series of ascending ethanol baths, critical point dried, coated with gold in a vacuum evaporator, and observed with a scanning electron microscope(JEOL, JSM-840-A, 20kV). For histologic examination taken specimens were embedded in paraffin, sectioned 6-8micrometer in thickness. The specimens were stained with hematoxylin-eosin stain method, examined under light microscope. The results were as follows; 1. The patency rate of control group was 92% and experimental group was 86%. 2. Endothelial cells regeneration at the anastomosis site of both group was partially appeared on the 1st week after experiment. 3. On the 2nd week after experiment, anastomosis site was completely covered with regenerated endothelial cell in both group, and the endothelial cell proliferated toward the graft at experimental group. 4. On the 4th, 8th week after experiment, the grafted artery was partially covered with endothelial cell at experimental group.
Allografts* ; Animals ; Arteries ; Baths ; Cacodylic Acid ; Carotid Arteries ; Endothelial Cells ; Ethanol ; Humans ; Osmium ; Paraffin ; Perfusion ; Prostheses and Implants ; Rats* ; Rats, Sprague-Dawley ; Regeneration ; Research Personnel ; Thrombosis ; Transplants ; Vacuum ; Veins

BACKGROUND: Arsenic is a carcinogenic heavy metal that has a species-dependent health effects and abandoned metal mines are a source of significant arsenic exposure. Therefore, the aims of this study were to analyze urinary arsenic species and their concentration in residents living near abandoned metal mines and to monitor the environmental health effects of abandoned metal mines in Korea. METHODS: This study was performed in 2014 to assess urinary arsenic excretion patterns of residents living near abandoned metal mines in South Korea. Demographic data such as gender, age, mine working history, period of residency, dietary patterns, smoking and alcohol use, and type of potable water consumed were obtaining using a questionnaire. Informed consent was also obtained from all study subjects (n = 119). Urinary arsenic species were quantified using high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP/MS). RESULTS: The geometric mean of urinary arsenic (sum of dimethylarsinic acid, monomethylarsonic acid, As3+, and As5+) concentration was determined to be 131.98 μg/L (geometric mean; 95% CI, 116.72–149.23) while urinary inorganic arsenic (As3+ and As5+) concentration was 0.81 μg/L (95% CI, 0.53–1.23). 66.3% (n = 79) and 21.8% (n = 26) of these samples exceeded ATSDR reference values for urinary arsenic (>100 μg/L) and inorganic arsenic (>10 μg/L), respectively. Mean urinary arsenic concentrations (geometric mean, GM) were higher in women then in men, and increased with age. Of the five regions evaluated, while four regions had inorganic arsenic concentrations less than 0.40 μg/L, one region showed a significantly higher concentration (GM 15.48 μg/L; 95% CI, 7.51–31.91) which investigates further studies to identify etiological factors. CONCLUSION: We propose that the observed elevation in urinary arsenic concentration in residents living near abandoned metal mines may be due to environmental contamination from the abandoned metal mine. TRIAL REGISTRATION: Not Applicable (We do not have health care intervention on human participants).
Arsenic* ; Cacodylic Acid ; Chromatography, Liquid ; Delivery of Health Care ; Drinking Water ; Environmental Health ; Female ; Humans ; Informed Consent ; Internship and Residency ; Korea* ; Male ; Mass Spectrometry ; Plasma ; Reference Values ; Smoke ; Smoking

OBJECTIVETo investigate the changes in mRNA expression of p53 and related downstream genes in peripheral blood lymphocytes in workers occupationally exposed to arsenic as well as its influencing factors, and to analyze the mechanism of genetic toxicity of arsenic.

METHODSWith cluster random sampling, 79 workers from an arsenic smelting plant were selected as exposure group, and another 24 people without occupational exposure to arsenic were selected as control group. The relative mRNA expression of p53 and related downstream genes in the peripheral blood lymphocytes of the two groups was determined by quantitative realtime PCR. The levels of inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine were determined by hydride generation-atomic absorption spectrometry.

RESULTSThe exposure group had significantly higher levels of iAs, MMA, and DMA than the control group (P<0.01); the exposure group had significantly higher relative mRNA expression (2(-ΔΔCt)) of p53 and four related downstream genes in peripheral blood lymphocytes than the control group (P<0.05); the relative mRNA expression of p53 and related downstream genes was positively correlated with each other (P<0.01), with a correlation coefficient greater than 0.4; the levels of arsenic compounds in urine were positively correlated with the relative mRNA expression of p53 and some of its downstream genes (P<0.05).

CONCLUSIONThe changes in mRNA expression of p53 and related downstream genes are closely related to the metabolic transformation of inorganic arsenic in workers occupationally exposed to arsenic, and it also plays an important role in genetic toxicity and carcinogenic effect in people exposed to arsenic.

Arsenic ; adverse effects ; urine ; Arsenicals ; urine ; Cacodylic Acid ; urine ; Case-Control Studies ; Humans ; Lymphocytes ; drug effects ; Occupational Exposure ; RNA, Messenger ; metabolism ; Tumor Suppressor Protein p53 ; metabolism

In our previous work, we found that trivalent dimethylarsinous acid (DMA(III)) have high affinity binding to cysteine residue 13 of rat hemoglobin. However, it is still unknown why arsenic intermediate metabolite DMA(III) has high binding affinity for Cysl3 but not for other cysteine residues 93, 140, 111 and 125. In order to better understand the molecular mechanism of DMA(III) with rat hemoglobin, we have done current study. So, SD rats were divided into control and arsenic-treated groups randomly. Arsenic species in lysate of red blood cells were analyzed by HPLC-ICP-MS, and then determined by a hybrid quadrupole TOF MS. In addition, trivalent DMA(III) binds to different cysteine residues in rat hemoglobin alpha and beta chains were also simulated by Molecular Docking. Only Cys13 in alpha chain is able to bind to DMA(III) from the experiment results. Cys13 of alpha chain in rat hemoglobin is a specific binding site for DMA(III), and we found that amino acids compose pockets structure and surround Cys13 (but not other cysteine residues), make DMA(III) much easy to bind cysteine 13. Taken together, the DMA(III) specific binding to Cys13 is related to spatial structure of Cys13.
Animals ; Arsenic ; metabolism ; Binding Sites ; Cacodylic Acid ; analogs & derivatives ; chemistry ; Chromatography, High Pressure Liquid ; Cysteine ; metabolism ; Hemoglobins ; metabolism ; Mass Spectrometry ; Peptide Fragments ; metabolism ; Rats

BACKGROUND AND OBJECTIVES: Displaced otoconia in the semicircular canal from senile otoconial degeneration have been believed as a major cause of benign paroxysmal positional vertigo (BPPV). The otoconia are mainly composed of calcium carbonate, and thus they are susceptible to chemical deformation during the usual process of scanning electron microscopy (SEM). The aims of this study were to present an optimal protocol of otoconial preparation for SEM and to investigate the change of otoconial morphology due to aging. SUBJECTS AND METHOD: The macula in mice were dissected free from the temporal bone and were divided into three groups using different fixatives and buffers: 2.5% glutaraldehyde in phosphate buffer, 2.5% glutaraldehyde in cacodylate buffer and 70% acetone. The duration of storage in buffer differed for each group, and SEM was used to examine the morphology. After the optimal processing protocol was made, we analysed the difference in the otoconial morphology in younger and older rats. RESULTS: The otoconia with shorter storage duration in phosphate buffer had more clear surface, while longer exposures resulted in coarse surface and fused otoconia. The otoconia stored in cacodylate buffer had smooth surface and showed grossly normal morphology regardless of exposure time. The otoconia fixed in acetone had irregular surface and was easily displaced. In older rats, the bodies of many otoconia were pitted, fissured, penetrated and eventually broken into several fragments. The size variation of utricular otoconia was greater in older rats. The giant otoconia were discovered frequently on the outer margin of utricular macula in older rats. The weakened or linked filaments that were cut in the older group were frequently observed. CONCLUSION: The appropriate processing for SEM is needed to observe the intact otoconial morphology. Older rats showed more degeneration of otoconia and linked filaments. This study for morphologic changes of senile otoconia is expected to be helpful in understanding the etiology of BPPV and aging effect.
Acetone ; Aging* ; Animals ; Buffers ; Cacodylic Acid ; Calcium Carbonate ; Fixatives ; Glutaral ; Mice ; Microscopy, Electron, Scanning* ; Otolithic Membrane* ; Rats ; Semicircular Canals ; Temporal Bone ; Vertigo