마우스에서 dibutyl phthalate 급성 투여가 간 지질과산화와 gamma-glutamyl transferase 활성에 미치는 효과

최달웅,김영환 대한환경위생공학회 2004 대한환경위생공학회지 Vol.19 No.1

Dibutyl phthalate (DBP) is used extensively in the plastic industry and has been known as an endocrine disruptor. Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyl transferase (GGT) activity. The serum toxicity index, level of lipid peroxidation and triglyceride (TG), and activity of GGT were measured in male ICR mice after a single administration of DBP (5 g/kg, po). DBP did not alter serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, glucose and cholesterol level. However, the treatment with DBP was found to significantly increase the level of lipid peroxidation in liver and lung. The TG content and activity of GGT in the liver of DBP-exposed animals was also increased. These results indicate that DBP can induce mild oxidative stress in mice. The GGT activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

고려홍삼 성분과 알코올 숙취에 미치는 영향에 대한 연구

최달웅,이성동,권영민,김순자,김부현,강현숙,박채규,이종태,전병선,고성룡,손현주 고려인삼학회 2008 고려인삼학회 학술대회 Vol.2008 No.12

HepG2 세포에서 용매에 의한 차별적인 사람 싸이토크롬 P450 2E1활성 변화

최달웅 한국환경보건학회 2003 한국환경보건학회지 Vol.29 No.3

The modification of CYP2El activity is a matter of considerable interest because of its role in the metabolic activation of a variety of environmental toxicants. In the present study, the time-course of changes in human CYP2El activities was determined following treatment with solvents (acetone, dimethylsulphoxide or pyridine) using intact HepG2 cells transfected by human CYP2El. Hydroxylation of chlorzoxazone was used for the measurement of CYP2El activity. CYP2E1 protein level was increased upon cultivation of cells in the presence of the solvents for 24 hr. Determination of CYP2El activities after 24 ht cultivation with the solvents demonstrated that acetone or dimethylsulphoxide increased, whereas pyridine inhibited the activities. This differential effect of the solvents on CYP2El activities persisted to subsequent 24 ht. Competitive inhibition study suggested that pyridine has stronger binding affinity to CYP2E1 than acetone or dimethylsulphoxide. These results demonstrate that different binding affinity of the solvents to CYP2El plays important role in determining real CYP2El activity in intact cells after exposure to the solvents. Present study would be helpful in precise understanding of human CYP2El-mediated toxicity.

Comparison between Source-induced Dissociation and Collision-induced Dissociation of Ampicillin, Chloramphenicol, Ciprofloxacin, and Oxytetracycline via Mass Spectrometry

최달웅,이승하 한국독성학회 2013 Toxicological Research Vol.29 No.2

Mass spectrometry (MS) is a very powerful instrument that can be used to analyze a wide range of materials such as proteins, peptides, DNA, drugs, and polymers. The process typically involves either chemical or electron (impact) ionization of the analyte. The resulting charged species or fragment is subsequently identified by the detector. Usually, single mass uses source-induced dissociation (SID), whereas mass/mass uses collision-induced dissociation (CID) to analyze the chemical fragmentations Each technique has its own advantages and disadvantages. While CID is most effective for the analysis of pure substances, multiplestep MS is a powerful technique to get structural data. Analysis of veterinary drugs ampicillin, chloramphenicol, ciprofloxacin, and oxytetracycline serves to highlight the slight differences between SID and CID. For example, minor differences were observed between ciprofloxacin and oxytetracycline via SID or CID. However, distinct fragmentation patterns were observed for ampicllin depending on the analysis method. Both SID and CID showed similar fragmentation spectra but different signal intensities for chloramphenicol. There are several factors that can influence the fragmentation spectra, such as the collision energy, major precursor ion, electrospray mode (positive or negative), and sample homogeneity. Therefore, one must select a fragmentation method on an empirical and case-by-case basis.

A Study on Hazard Assessment of Employees in New Buildings

최달웅 한국독성학회 2012 Toxicological Research Vol.28 No.3

In order to evaluate the physical and psychological health effects of air pollutants from new building materials, 100 employees who worked in new buildings were given a general health questionnaire, and the prevalence of their subjective complaints was measured. The collected data were classified according to age, gender, smoking status, profession, working time, sleep time, life style, and length of employment. The results obtained were summarized as follows: The THI lie scale scores were significantly higher among the older respondents. Compared to males, females showed a significantly higher level in the depression itemas well asa tendency toward high ratios of physical and psychological complaints. The smoking group showed higher scores regarding health complaints related to most physical and psychological items. Smokers showed significantly increased respiratory organ complaints compared to nonsmokers. Those with a profession showed significantly higher level of nervousness. The group of those working 7 to 10 hours group showed higher rates of complaints in the multiple subjective symptoms and mouth/anus items than the group working less than 2 hours. Those living an irregular life showed a tendency toward higher rates of complaints for most physical and psychological subjective factors. Those who were satisfied with their environments showed significantly lower scores in the mouth/anus, impulsiveness, mental irritability, depression, and nervousness items. In summary, this study shows that the health complaint scores regarding physical and psychological symptoms tended to be higher among the unsatisfied group, the irregular life group, the group who worked long hours, the elderly, smokers, and females. These results can be used to improve the psychosomatic health status and working environments of employees working in new buildings.

A Study on Health Hazards to Employees near Main Streets

최달웅 한국독성학회 2012 Toxicological Research Vol.28 No.3

In order to evaluate the physical and psychological health effects from automobile air pollution, 99 employees who worked near a main street were given a general health questionnaire, and the prevalence of their subjective complaints was measured. The collected data were classified according to gender, sleep time, degree of regular exercise, self-consciousness of symptoms, length of employment, work time, rest time, and smoking status. The results obtained were summarized as follows: The scores related to health complaints regarding physical and psychological items were higher in females than in males. THI scores were higher for the < 4 hour sleep time group. The health complaint scores for physical items were higher in the regular exercise group, whereas most scores for mental items were higher in the irregular exercise groups. The health complaints scores for physical and psychological items were higher in the unhealthy symptom group than in other groups. Those employees who had worked for > 4 years showed significantly higher rates of complaints regarding the eyes and skin. THI scores were higher for the < 6 hour working time group. The smoking group showed higher scores regarding health complaints related to physical items. The THI scores of the respiratory organs, mouth, anus, and digestive organs were significantly higher for the smoking group than for the non-smoking group. In summary, this study shows that the health complaint scores regarding physical and psychological symptoms tended to be higher among the unhealthy group, the less sleep time group, the less work time group, smokers, and females. These results can be used to improve the psychosomatic health status and working environments of employees who work near a main street.

마우스에서 bibutyl phthalate 급성 투여가 간 지질과산화와 gamma-glutamy1 transferase 활성에 미치는 효과

최달웅(Dal-Woong Choi),김영환(Young-Hwan Kim) 대한환경위생공학회 2004 대한환경위생공학회지 Vol.19 No.1

Dibutyl phthalate (DBP) is used extensively in the plastic industry and has been known as an endocrine disruptor. Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyl transferase (GGT) activity. The serum toxicity index, level of lipid peroxidation and triglyceride (TG), and activity of GGT were measured in male ICR mice after a single administration of DBP (5 g/kg, po). DBP did not alter serum alanine aminotransferase (AL T), aspartate aminotransferase (AST), creatinine, glucose and cholesterol level. However, the treatment with DBP was found to significantly increase the level of lipid peroxidation in liver and lung. The TG content and activity of GGT in the liver of DBP-exposed animals was also increased. These results indicate that DBP can induce mild oxidative stress in mice. The GGT activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

Dimethyl sulfoxide가 포름알데히드와 유기용제류에 의한 세포 성장 억제에 미치는 영향

최달웅(DalWoong Choi) 고려대학교 보건과학연구소 2006 보건과학논집 Vol.32 No.1

  Dimethyl sulfoxide has been shown to have toxicity interaction with many organic solvents. Dimethyl sulfoxide was shown to enhance toxicity of solvents, while some other studies demonstrated reduction of solvent toxicity by dimethyl sulfoxide. Form-aldehyde is a toxic and irritant indoor air pollutant found at relatively high concentrations in new house, schools and offices in developed countries. Exposure to formaldehyde elicits a variety of allergic signs and symptoms and irritates human cell. We are highly exposed to formaldehyde in living environment. The aim of the present study was to investigate the effect of dimethyl sulfoxide and formaldehyde or organic solvents on the cell growth. Cell growth was measured after 24h treatment with formaldehyde or organic solvents such as toluene, ethylbenzene, isopropyl alcohol, carbon tetrachloride, pyridine, glycerine. The cell growth was not inhibited after exposure of isopropyl alcohol(100 mM), pyridine(100 mM) or glycerine(100 mM). Treatment of formaldehyde(100 mM), toluene(100 mM), ethylbenzene(100 mM) and carbon tetrachloride(100 mM) strongly inhibited the cell growth. However, treatment of 10mM toluene, 10 mM ethylbenzene and 10mM carbon tetrachloride showed no effects on cell growth. The most potent inhibition of cell growth was observed after exposure to formaldehyde. Even 1 mM formaldehyde strongly inhibited cell growth. The cell growth was also measured after 24 h co-exposure of dimethyl sulfoxide and formaldehyde or organic solvents. Addition of dimethyl sulfoxide did not modify the cell proliferation pattern induced by organic solvents. Any antagonistic or additive effect of dimethyl sulfoxide was not observed. These results show that organic solvents induce inhibition of cell growth with different potency. These study can give valuable information about toxicity interaction of dimethyl sulfoxide and formaldehyde or organic solvents.

HepG2 세포에서 Ethanol, Glycerol, 4-methylpyrazole 및 Isoniazid에 의한 Human CYP2E1 활성 변화

최달웅(Dal-Woong Choi) 한국독성학회 2003 Toxicological Research Vol.19 No.3

The modification of CYP2E1 activity is of considerable interest because of its role in the metabolic activation of a variety of toxic chemicals. In the present studies, the time-course of changes in human CYP2E1 activities was determined after treatment with ethanol, glycerol, 4-methylpyrazole or isoniazid using intact HepG2 cells transfected by human CYP2E1. Hydroxylation of chlorzoxazone was chosen for the measurement of CYP2E1 activity. CYP2E1 protein levels were increased upon cultivation of cells in the presence of ethanol, glycerol, 4-methylpyrazole or isofor 24 hr. After 24 hr cultivation, ethanol or glycerol increased CYP2E1 activities, whereas 4or isoniazid inhibited. This different effect of the chemical inducers on CYP2E1 activities persisted to subsequent 24 hr. Competitive inhibition study suggested that 4-methylpyrazole or isoniazid has stronger binding affinity to CYP2E1 than ethanol or glycerol. These results demonstrate that different binding affinity of the chemical inducers to the active site of CYP2E1 plays important role in determining real CYP2E1 activity in intact cells after treatment with the chemical inducers. Present study would be helpful in precise understanding of human CYP2E1-mediated toxicity.

Diagnosis of Trace Toxic Uranium Ions in Organic Liver Cell

이수영,최달웅,박은철 한국독성학회 2014 Toxicological Research Vol.30 No.2

Uranium is toxic and radioactive traces of it can be found in natural water and soils. High concentrations of it in biological systems cause genetic disorders and diseases. For the in vivo diagnosis, micro and nano range detection limits are required. Here, an electrochemical assay for trace toxic uranium was searched using stripping voltammetry. Renewable and simplified graphite pencils electrode (PE) was used in a three-electrode cell system. Seawater was used instead of an electrolyte solution. This setup can yield good results and the detection limit was attained to be at 10 μgL−1. The developed skill can be applied to organic liver cell.