• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.1
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• pp.23-34
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• 2012

Purpose: Acute symptomatic seizures are caused by structural changes, inflammation or metabolic changes of brain, such as tumor, stroke, meningitis, encephalitis and metabolic disorders. Inherited metabolic disorders that can cause seizures are organic acidopathies, lysosomal storage disorders, peroxisomal disorders and mineral disorders. We have done this study to find out the importance of organic acidopathies causing seizure disorders in Korean childhood and adolescent patients. Method: Retrograde analysis for 1,306 patients with seizure disorders whose clinical informations are available and have done urine organic acid analysis for 5 years period, between Jan. 1st 2007 to Dec. 31th 2011. Statistical analysis was done with Student's t test using SPSS. Result: Out of 1,306 patients, 665 patients (51%) showed abnormalities on urine organic acid analysis. The most frequent disease was mitochondrial respiratory chain disorders (394, 30.1%), followed by mandelic aciduria (127, 9.7%), ketolytic defects (81, 6.2%), 3-hydroxyisobutyric aciduria (19, 1.4%), glutaric aciduria type II (10, 0.8%), ethylmalonic aciduria (4), propionic aciduria (4), methylmalonic aciduria (3), glutaric aciduria type I (3), pyruvate dehydrogenase deficiency (3), pyruvate carboxylase deficiency (3), isovaleric aciduria (2), HMG-CoA lyase deficiency (2), 3-methylcrotonylglycinuria (2), fatty acid oxidation disorders (2), fumaric aciduria (1), citrullinemia (1), CPS deficiency (1), MCAD deficiency (1). Conclusion: On neonatal period, mandelic aciduria due to infection was found relatively frequently. Mitochondrial disorders are most frequent etiologic disease on all age group, followed by ketolytic defects and various organic acidopathies. The number and diversities of organic acidopathies emphasize meticulous evaluation of basic routine laboratory examinations and organic acid analysis with initial sample on every seizure patient.

• 대한예방의학회:학술대회논문집
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• 1993.10a
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• pp.65-66
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• 1993

• Bulletin of the Korean Chemical Society
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• v.1 no.3
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• pp.78-82
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• 1980

Solutions of $Cd^{2+}$, $Co^{2+}$ and $Ni^{2+}$ were mixed with the solutions of hydroxycarboxylic acids such as salicylic, lactic and mandelic acids in the presence of cation exchange resin at room temperature. The distribution ratios of the metal ions between resin and solution were measured, using radioactive metal ions as tracer. From the observed variation of the distribution ratios with the acid anion concentrations, it was concluded that $Cd^{2+}$, $Co^{2+}$ and $Ni^{2+}$ formed the one-to-one complexes with salicylate, lactate and mandelate ions in aqueous, 20 % ethanol-water and 20 % acetone-water solutions. The results of the present study indicated that the relative stabilities of the metal-acid complexes in solution increased in the order: $Cd^{2+}$ <$Co^{2+}$ <$Ni^{2+}$ complexes. Salicylate

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.2
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• pp.161-170
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• 1997

This is an effort to confirm changes biological monitoring according to changes in levels of exposure to styrene for industrial workers. This study was conducted on 108 workers, including male of 64 and female 44 who were working at factories of FRP, dipping, and coating. An improved passive monitor method(organic vapor monitor; OVM) was employed to determine levels of exposure. The biological monitoring include blood styrene concentration, urinary mandelic acid(MA), and urinary phenylglyoxylic acid(PGA). Biological monitoring were made through the Collection of blood and urine. The mean value of exposure to styrene was 21.0ppm, which is measured by organic vapor monitor, one of improved passive monitors. The highest exposure level was observed among workers in boat factories, laminating procedure workers, processing workers, respectively(p<0.01). For exposure level, 11% of subjects under study showed over 50ppm which is time weighted average(TWA). The correlation coefficient between biological specimens and the exposure level was 0.62 for blood styrene concentration, 0.58 for MA corrected by creatinine, and 0.70 for PGA corrected by creatinine, respectively(p<0.01). The regression analyses found exposure level relative importance in explaining variance in biological monitoring. In additional to that, gender was a significant factor in explaining variance of MA and MA+PGA. Almost half of variance(49%) in blood styrene concentration was explained by predictors, including exposure level, age, gender, duration, and drinking volume during the last week(p<0.01). The very high correlation(higher than 0.95 was found when a comparison was made among three types of corrected methods, including uncorrected specific gravity and creatinine. In conclusion, these findings suggest OVM to represent levels of exposure to styrene for industrial workers. A discussion was made on possible use of specific gravity sample for biological monitoring. Exposure level may be predicted on MA, PGA in urine, which could be applied to represent biological monitoring.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.235-244
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• 2007

By comparing the proteins from the workers exposed to styrene with the ones from controls, it may be possible to identify proteins that play a role in the occurrence and progress of occupational disease and thus to study the molecular mechanisms of occupational disease. In order to find the biomarkers for assessing the styrene effects early, before clinical symptoms develop and to understand the mechanisms of adverse health effects, we surveyed 134 employees, among whom 52 workers(30 male and 22 female) were chronically exposed to styrene in 10 glass-reinforced plastic boat manufacturing factories in Korea and 82 controls had never been occupationally exposed to hazardous chemicals including styrene. The age and drinking habits and serum biochemistry such as total protein, BUN and serum creatinine in both groups were significantly different. Exposed workers were divided into three groups according to exposure levels of styrene(G1, below 1/2 TLV; G2, 1/2 TLV to TLV; G3, above TLV). The mean concentration of airborne styrene in G1 group was $10.93{\pm}11.33ppm$, and those of urinary mandelic acid(MA) and phenylglyoxylic acid(PGA) were $0.17{\pm}0.21$ and $0.13{\pm}0.11g/g$ creatinine, respectively. The mean concentration of airborne styrene in G2 and G3 groups were $47.54{\pm}22.43$ and $65.33{\pm}33.47ppm$, respectively, and levels of urinary metabolites such as MA and PGA increased considerably as expected with the increase in exposure level of styrene. The airborne styrene concentration were significantly correlated to the urinary concentration of MA(r=0.784, p=0.000) and PGA(r=0.626, p<0.001). In the 2D electrophoresis, the concentration of five proteins including complement C3 precursor, alpha-1-antitrypsin(AAT), vitamin D binding protein precursor(DBP), alpha-1-B-glycoprotein(A1BG) and inter alpha trypsin inhibitor(ITI) heavy chain-related protein were significantly altered in workers exposed to styrene compared with controls. While expression of complement C3 precursor and AAT increased by exposure to styrene, expression of DBP, A1BG and ITI heavy chain-related protein decreased. These results suggest that the exposure of styrene might affects levels of plasma proteinase, carriers of endogenous substances and immune system. In particular, increasing of AAT with the increase in exposure level of styrene can explain the tissue damage and inflammation by the imbalance of proteinase/antiproteinase and decrease of DBP, A1BG and ITI heavy chain-related protein in workers exposed to styrene is associated with dysfunction and/or declination in immune system and signal transduction

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.21-28
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• 1999

This study was carried out the simultaneous removal or organics and Cr(VI) in aqueous suspensions of phtocatalyst under circular type reactor and UV light illumination. In this experiment, comparison on the removal of Cr(VI) by photoreduction using UV light, photocatalyst adsorption using TiO2, ZnO, and FeCl3 as photocatalyst, and phtocatalysis using UV light with photocatalysts as well as the effect of experimental parameters such as phtocatalyst dosage, a kinds of organics and their concentration was examined. The major results of this study were as follows; 1. It was found that photocatalyst adsorption and phtocatalysis were applicable to the removal of Cr(VI), and Cr(VI) was more effectively eliminated by TiO2 than ZnO, and FeCl3. 2. phtocatalytic removal efficiency of Cr (VI) increased with increasing phtocatalyst dosage. However, over 1.0g/l of phtocatalyst dosage, the efficiency reached a plateau. 3. phtocatalytic removal of Cr(VI) was enhanced by addition of organics such as salicylic acid, mandelic acid, EDTA, and citric acid, and phtocatalytic oxidation of organics were also observed. 4. It was found that the simultaneous removal of organics and Cr(VI) using phtocatalysis was possible.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.244-247
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• 2020

We have expressed extracellular poly(3-hydroxybutyrate) (PHB) depolymerase of Ralstonia pickettii T1 on the Escherichia coli surface using Pseudomonas OprF protein as a fusion partner by C-terminal deletion-fusion strategy. Surface display of depolymerase was confirmed by flow cytometry, immunofluorescence microscopy and whole cell hydrolase activity. For the application, depolymerase was used as an immobilized catalyst of enantioselective hydrolysis reaction for the first time. After 48 h, (R)-methyl mandelate was completely hydrolyzed, and (S)-mandelic acid was produced with over 99% enantiomeric excess. Our findings suggest that surface displayed depolymerase on E. coli can be used as an enantioselective biocatalyst.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.1
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• pp.15-20
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• 2015

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and ${\gamma}$-aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.

• Toxicological Research
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• v.31 no.4
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• pp.355-361
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• 2015

The aim of this study was to investigate whether genetic polymorphisms of CYP2E1, GSTM1, and GSTT1 and lifestyle habits (smoking, drinking, and exercise) modulate the levels of urinary styrene metabolites such as mandelic acid (MA) and phenylglyoxylic acid (PGA) after occupational exposure to styrene. We recruited 79 male workers who had received chronic exposure in styrene fiberglass-reinforced plastic manufacturing factories. We found that serum albumin was significantly correlated with blood styrene/ambient styrene (BS/AS), urinary styrene (US)/AS, and US/BS ratios as well as urinary metabolites, that total protein correlated with US/MA and US/PGA ratios, and that low density lipoprotein (LDL)-cholesterol significantly correlated with US/BS, US/MA, and US/PGA ratios. Multiple logistic regression analyses using styrene-metabolizing enzyme genotypes and lifestyle habits as dependent variables and blood and urine styrene concentrations and urine styrene metabolite levels as independent variables revealed that $CYP2E1^*5$ was associated with the MA/US ratio and GSTM1 with US/BS, that a smoking habit was associated with US/AS and MA/US ratios and MA and PGA levels, and that regular exercise was correlated with PGA/US. In conclusion, the results suggested that genetic polymorphisms of styrene-metabolizing enzymes, lifestyle behaviors, and albumin and LDL-cholesterol serving as homeostasis factors together are involved in styrene metabolism.

• Safety and Health at Work
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• v.2 no.3
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• pp.229-235
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• 2011

Objectives: In this study, we summarized the External Quality Assessment Scheme (EQAS) for the biological monitoring of occupational exposure to toxic chemicals which started in 1995 and continued until a $31^{st}$ round robin in the spring of 2010. The program was performed twice per year until 2009, and this was changed to once a year since 2010. The objective of the program is to ensure the reliability of the data related to biological monitoring from analytical laboratories. Methods: One hundred and eighteen laboratories participated in the $31^{st}$ round robin. The program offers 5 items for inorganic analysis: lead in blood, cadmium in blood, manganese in blood, cadmium in urine, and mercury in urine. It also offers 10 items for organic analysis, including hippuric acid, methylhippuric acid, mandelic acid, phenylglyoxylic acid, N-methylformamide, N-methylacetamide, trichloroacetic acid, total trichloro-compounds, trans,trans-muconic acid, and 2,5-hexanedione in urine. Target values were determined by statistical analysis using consensus values. All the data, such as chromatograms and calibration curves, were reviewed by the committee. Results: The proficiency rate was below 70% prior to the first round robin and improved to over 90% for common items, such as PbB and HA, while those for other items still remained in the range of 60-90% and need to be improved up to 90%. Conclusion: The EQAS has taken a primary role in improving the reliability of analytical data. A total quality assurance scheme is suggested, including the validation of technical documentation for the whole analytical procedure.