• 한국산업보건학회지
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• 제22권4호
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• pp.316-328
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• 2012

Objectives: This study was designed to provide the information regarding chemicals classification and health hazard by evaluating the toxicological effect through repeated inhalation exposure of methyl acrylate(MA) in Sprague-Dawley(SD) rat for 13 weeks. Methods: According to the notification with Ministry of Labor(No. 2009-68) and OECD Test Guideline 413, the rats were exposed to MA at concentration of 0, 56, 168, 280 ppm via whole body inhalation for 6 hours per day, 5 days per week, for 13 weeks. All animals were observed for mortality, morbidity and the change of body weight and food consumption were determined during the exposure period. Necropsy finding, organ weight, hematology, clinical biochemistry and histopathological examination following exposure were also performed. Results: There were no death and abnormal clinical signs relate to exposure MA. However, At 160 ppm and 280 ppm exposure groups, body weight and food consumption showed statistically significant decrease and histopathological changes in lung, trachea, nasal cavity, larynx were observed. Conclusions: MA was mainly affected respiratory tract. It is consequently provided to be classified as category 2(0.2 mg/L/6h < category 2 ${\leq}$ 1.0 mg/L/6h) for specific target organ toxicity following repeated exposure according to Standard for Classification and Labeling of Chemical Substance and Material Safety Data Sheet. The NOAEL(no observable adverse effect level) of MA was also determined to be lower than 56 ppm.

• 대한한방내과학회지
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• 제36권2호
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• pp.189-199
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• 2015

Objectives: The marker substances of cultivated wild ginseng pharmacopuncture that may not be detected during the process of steaming remain controversial. We developed a combined cultivated wild ginseng pharmacopuncture that contains all the marker substances. The aim of this experiment was to investigate the marker substances and test the toxicity of the combined cultivated wild ginseng pharmacopuncture. Methods: The marker substances were detected using HPLC. Intravenous injection toxicity studies were conducted at Medvill, an authorized institution for non-clinical studies, under the regulations of Good Laboratory Practice. We observed survival rates, abnormal behaviors, weight changes, gross findings in autopsy, blood biochemical properties, and histological abnormalities of organs such as the liver and kidney. Results: HPLC data showed that ginsenosides Rg1, Rb1, and Rg3 were detected at concentrations of 19.29, 47.64, and 3.02 μ g /ml, respectively. Administration of combined cultivated wild ginseng pharmacopuncture resulted in no dead animals or significant toxicological changes. Conclusions: The combined cultivated wild ginseng pharmacopuncture contains all the marker substances and is a relatively safe treatment medium. Further studies should be conducted to confirm the present findings.

• Toxicological Research
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• 제19권4호
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• pp.267-275
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• 2003

The purpose of our study was to evaluate the toxicity of the thimerosal in embryos and neonates. Thimerosal (also known as mercurothiolate) is a mercury-containing compound used in trace amounts to prevent bacteria and other organisms from contaminating vaccines, especially in opened multi-dose vials. The toxicity of mercury is well known and those most at risk occurrs in unborn babies and newborn babies. Test methods included in vitro whole embryo culture (WEC) system and in vivo test of neonatal toxicity in Wistar rats. Ethylmercury and methylmercury were used as positive controls for the evaluating of toxic effects of mercury. In WEC assay, treated concentrations of thimerosal, ethylmercury and methylmercury were up to 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5 and 5 $\mu\textrm{g}$/$\textrm{m}{\ell}$, respectively. All compounds didn't show any morphological abnormalities, but showed retardation of growth and development in dose dependent manner (> 0.5 $\mu\textrm{g}$/$\textrm{m}{\ell}$). These data indicated that thimerosal showed developmental toxicity in vitro. In vivo neonatal toxicity, Wistar rats were administered subcutaneously with thimerosal, ethyl mercury, or methylmercury (5, 25, 50, 250, and 500 $\mu\textrm{g}$/kg) during from postnatal day (PND) 4 to 25. Significant effects of these compounds on relative organ weights and organ morphology were not observed in this experiment. However, accumulation of mercury was detected in the kidney and testis when treated with thimerosal, ethylmercury, or methylmercury. These results suggest that thimerosal may be a harmful compound to embryo and neonate, but used concentration of thimerosal in these experiments is much higher than that of clinical application. Further investigation is needed on the safety of vaccine components, i.e. a thimerosal using in vitro and in vivo tests in the future.

• Toxicological Research
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• 제28권3호
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• pp.143-149
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• 2012

To prepare measures for practical policy utilization and the control of heavy metals, hazard control related institutions by country, present states of control by country, and present states of control by heavy metals were examined. Hazard control cases by heavy metals in various countries were compared and analyzed. In certain countries (e.g., the U.S., the U.K., and Japan), hazardous substances found in foods (e.g., arsenic, lead, cadmium, and mercury) are controlled. In addition, the Joint FAO/WHO Expert Committee on Food Additives (JECFA) recommends calculating the provisional tolerable weekly intake (PTWI) of individual heavy metals instead of the acceptable daily intake (ADI) to compare their pollution levels considering their toxicity accumulated in the human body. In Korea, exposure assessments have been conducted, and in other countries, hazardous substances are controlled by various governing bodies. As such, in Korea and other countries, diverse food heavy metal monitoring and human body exposure assessments are conducted, and reducing measures are prepared accordingly. To reduce the danger of hazardous substances, many countries provide leaflets and guidelines, develop hazardous heavy metal intake recommendations, and take necessary actions. Hazard control case analyses can assist in securing consumer safety by establishing systematic and reliable hazard control methods.

• Toxicological Research
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• 제23권3호
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• pp.263-269
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• 2007

Although taurine (2-aminoethanesulfonic acid) can inhibit oxidative stress in both animal and epidemiological studies, it is obscure whether taurine directly scavenges oxy-radicals or indirectly regulates oxidant production and/or antioxidant defense system. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating oxy-radical scavenging capacity. The antioxidant activities of taurine and hypotaurine (2-aminoethanesulfinic acid), a precursor of taurine, against peroxyl radicals, hydroxyl radicals and peroxynitrites were determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. tert-Butylhydroperoxide or hydrogen peroxide-induced cell toxicity determined by MTT assay was markedly inhibited by 10mM taurine or hypotaurine. The tert-butylhydroperoxide- or hydrogen peroxide-induced changes in oxidative stress markers, such as cellular glutathione and malondialdehyde, were ameliorated by 10mM taurine or hypotaurine. However, specific TOSC values calculated from the slope of the linear regression for taurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were all less than 1 TOSC/mM. On the other hand specific TOSC values for hypotaurine against peroxyl radicals, hydroxyl radicals or peroxynitrites were 48, 2096, or 69 TOSC/mM, respectively. These results suggest that taurine protects cells against oxidative insults, which is not ascribed to directly scavenging activity of taurine against oxy-radicals. These results support the idea that the oxidation state of sulfur in antioxidants may be a determinant of oxy-radical scavenging capacity.

• Toxicological Research
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• 제33권3호
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• pp.205-209
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• 2017

Transmembrane Protein 39A (TMEM39A) is a member of TMEM family. The understanding about this protein is still limited. The earlier studies indicated that TMEM39A was a key mediator of autoimmune disease. TMEM39A seems to be involved in systemic lupus erythematosus and multiple sclerosis in numerous of populations. All of these works stop at insufficient information by using gene functioning methods such as: Genome-wide association studies (GWASs) and/or follow-up study. It is the fact that the less understood of TMEM39A actually is the attraction to the scientist in near future. In this review the current knowledge about TMEM39A and its possible roles in cell biology, physiology and pathology will be described.

• Toxicological Research
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• 제30권1호
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• pp.55-63
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• 2014

Objectives: The use of indium compounds, especially those of small size, for the production of semiconductors, liquid-crystal panels, etc., has increased recently. However, the role of particle size or the chemical composition of indium compounds in their toxicity and distribution in the body has not been sufficiently investigated. Therefore, the aim of this study was to examine the effects of particle size and the chemical composition of indium compounds on their toxicity and distribution. Methods: Male Sprague-Dawley rats were exposed to two different-sized indium oxides (average particle sizes under 4,000 nm [IO_4000] and 100 nm [IO_100]) and one nano-sized indium-tin oxide (ITO; average particle size less than 50 nm) by inhalation for 6 hr daily, 5 days per week, for 4 weeks at approximately $1mg/m^3$ of indium by mass concentration. Results: We observed differences in lung weights and histopathological findings, differential cell counts, and cell damage indicators in the bronchoalveolar lavage fluid between the normal control group and IO- or ITO-exposed groups. However, only ITO affected respiratory functions in exposed rats. Overall, the toxicity of ITO was much higher than that of IOs; the toxicity of IO_4000 was higher than that of IO_100. A 4-week recovery period was not sufficient to alleviate the toxic effects of IO and ITO exposure. Inhaled indium was mainly deposited in the lungs. ITO in the lungs was removed more slowly than IOs; IO_4000 was removed faster than IO_100. IOs were not distributed to other organs (i.e., the brain, liver, and spleen), whereas ITO was. Concentrations of indium in the blood and organ tissues were higher at 4 weeks after exposure. Conclusions: The effect of particle size on the toxicity of indium compounds was not clear, whereas chemical composition clearly affected toxicity; ITO showed much higher toxicity than that of IO.

• 한국발생생물학회지:발생과생식
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• 제6권1호
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• pp.45-54
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• 2002

골든 햄스터의 생식활동은 광주기에 의해 조절된다. 그들의 생식능력은 여름에 왕성하고 겨울에는 퇴화한다. 송과선에서 분비되는 멜라토닌은 계절적 번식동물에서 생식활동을 중재한다. 멜라토닌 수용체가 최근에 사람을 포함하는 몇몇 동물에서 확인되었지만 골든 햄스터의 생식능력과 관련하여 알려진 바가 많지 않다. 역전사 PCR 방법을 사용하여 멜라토닌 수용체의 일부 유전자를 동정하였다(309 염기). 멜라토닌 수용체의 핵산 서열과 추론된 아미노산 서열을 보고된 다른 동물들과 비교하였다. 멜라토닌 수용체는 시상하부, 뇌하수체, 혈액, 지라에서 명백히 탐지되었다. 광주기가 정소 무게 및 생식 호르몬에 현저한 영향을 주었지만 멜라토닌 수용체의 발현에는 영향을 뚜렷하게 보이지 않았다. 이러한 결과는 생식을 조절하는 멜라토닌은 그 수용체의 수보다 수용체에 결합하는 친화도가 더 중요함을 시사한다.

• 대한약침학회지
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• 제21권3호
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• pp.168-176
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• 2018

Objectives: Ma-al-shaeer is a popular beverage in Islamic countries. The aim of this study was to determine the concentrations of methanol and ethanol in most consumed brands of Ma-al-shaeer in Iran. Methods: Eighty-one Ma-al-shaeer samples which commonly used in Iran were provided. Methanol and ethanol contents were determined by gas chromatography with flame ionization detector. Results: The mean methanol concentrations in Iranian and foreign brands was $129.84{\pm}205.38mg/L$ and $110.157{\pm}135.98mg/L$, respectively. Although mean ethanol contents of Iranian brands was $1.2{\pm}2.41mg/L$, ethanol level in foreign ones was lower than LOQ. Conclusion: Since the most Ma-al-shaeer brands had methanol pollution at different levels establishment of a definitive relationship between the methanol content and toxicological effects seem to be vital. EDI of methanol for Iranian people through consumption of Maal-shaeer was determined 0.023mg/kg bw/day.

• Safety and Health at Work
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• 제11권2호
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• pp.235-240
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• 2020

Background: Cadmium exposure may induce chronic intoxication with renal damage. Silver soldering may be a source of cadmium exposure. Methods: We analyzed working environment measurement data and periodic health screening data from a small-scale silver soldering company with ten workers. Concentrations of cadmium in air from working environment measurement data were obtained. Concentrations of blood and urinary cadmium, urine protein, and urine β2-microglobulin (β2M) were obtained. The generalized linear model was used to identify the association between blood and urine cadmium and urine β2M concentrations. Clinical features of chronic cadmium intoxication focused with toxicological renal effects were described. Results: The mean duration of work was 8.5 years (standard deviation [SD] = 6.9, range = 3-20 years). Cadmium concentrations in air were ranged from 0.006 to 0.015 mg/㎥. Blood cadmium concentration was elevated in all ten workers, with a highest level of 34.6 ㎍/L (mean = 21.288 ㎍/L, SD = 11.304, range = 9.641-34.630 ㎍/L). Urinary cadmium concentration was elevated in nine workers, with a highest level of 62.9 ㎍/g Cr (mean = 22.151 ㎍/g creatinine, SD = 19.889, range = 3.228-62.971 ㎍/g creatinine). Urine β2M concentration was elevated in three workers. Urinary cadmium concentration was positively associated with urine protein concentration (beta coefficient = 10.27, 95% confidence interval = [4.36, 16.18]). Other clinical parameters were compatible with renal tubular damage. Conclusion: Cadmium intoxication may occur at quite low air concentrations. Exposure limit may be needed to be lowered.