Annals of Occupational and Environmental Medicine

Seon Hee Yang

3 Articles

Apoptosis of Neuronal Cells Induced by Lead: Seon Hee Yang, Dong Hoon Shin, Won Ki Baek; Korean Journal of Occupational and Environmental Medicine 1999;11(2):254-263. Published online June 30, 1999; DOI: https://doi.org/10.35371/kjoem.1999.11.2.254

Lead is a major environmental and occupational neurotoxicant. It has been shown that long-term exposure to a low level of lead impairs the development of brain. For example, it was reported that lead exposure during the childhood causes a learning difficulty and a memory deficit of children. Neurotoxic agents including the lead are believed to cause neuronal death in developing brain by two mechanisms: apoptosis and necrosis. However, the exact mechanism of neuronal death caused by lead exposure is still not known explicitly. In this study, we conducted a study to clarify a mechanism of hippocampal neuronal cell death caused by lead acetate. Hippocampal neurons were cultured for 14-16 days and treated with lead acetate of 1. 10, 100 1 microM concentrations for 12 hours. With the MTT(methyl tetrazolium test) kit, the viability of neuronal cells was measured. Next, in order to examine apoptosis caused by lead acetate, TUNEL (TdT-mediated d-UTP Nick End Labelling) assay was performed. It has been shown that lead acetate reduced the viability of neuronal cells in a dose dependent manner, especially at the concentration of 100 ~M lead acetate. TUNEL immunostain showed brownish signals in the nucleus of apoptotic cells. The proportions of apoptotic cells in the lead?acetate treated group were more higher than those in the controls and increased as lead acetate concentration increased. From above results, it may be concluded that lead in the hippocampal neuronal cells reduced cell viability and one of mechanisms in neuronal cell death by lead appears to be apoptosis.

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Teratogenic Effects of Lead in the Developing Chick Embryos
Aqsa Shafiq, . Mahnoor, Mirza Fahad Baig, Yashal Fatima, Arooj Haer, Shakila Parveen, Muhammad Akram Tariq, Muhammad Khalil Ahmad Khan
MARKHOR (The Journal of Zoology).2023; : 16. CrossRef

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Neurobehavioral Performance Changes of Chronic Exposure to Organic Solvents among Textile Processing Workers: Seon Hee Yang, Moo Sik Lee, Dong Hoon Shin; Korean Journal of Occupational and Environmental Medicine 1998;10(2):227-239. Published online May 31, 1998; DOI: https://doi.org/10.35371/kjoem.1998.10.2.227

Abstract PDF: The study was conducted to predict the risk of chronic exposure by neurobehavioral test and to use it as a basic source of the management for workers exposed to organic solvents. The exposed group was selected from coating department of textile processing industry. The unexposed group was selected from those who visited the clinic to take an annual check-up. The author administered WHO-NCTB (neurobehavioral core test battery). Also, Scandinavian Questionnaire 16 was tested by self-administration to find the correlation between subjective symptoms and NCTB results, and to assess the availability of the Questionnaire in mass screening test concurrently. The final analysed subjects were 78 (27 in exposed group and 51 in unexposed group) workers except who had a neurologic disease or systemic disease affecting the central nervous system. In Questionnaire study, there was no significant difference in total neurotoxic symptom scores between the exposed and the unexposed group. In NCTB, the exposed group had lower mean scores than the unexposed group for all tests. When the effect by age and education were considered, there was a statistically significant difference only in pursuit timing test. This study suggests the availability of NCTB and the Questionnaire for the assessment of neurobehavioral change in workers exposed to organic solvents.

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Effect of Cadmium on Cytokine Gene Expression in a Human Monocytic Cell Line, THP-1: Mi Jung Kang, Seon Hee Yang, In Sung Chung, Dong Hoon Shin, Kwan Kyu Park, Suk Kwon Suh; Korean Journal of Occupational and Environmental Medicine 1997;9(2):320-331. Published online June 30, 1997; DOI: https://doi.org/10.35371/kjoem.1997.9.2.320

Abstract PDF: Cadmium, a potent toxic metal, poses a serious environmental threat but the mechanism of its toxicity remains unclear. Also, cadmium is a known immunotoxic agent in animal studies and induces pathophysiological effects by modulating components of immune system. Cytokines are being increasingly recognized as essential mediators of normal and pathologic immune response. Cells of mononuclear phagocytic system are strategically located at portals of entry in humans and therefore may be particularly at risk for cadmium exposure through contaminated air, food, and drinking water. In the present study, we investigated the effect of cadmium cytotoxicity for the monocyte and expression of cytokine gene in the control and cadmium treated human monocytic cell lines using RT-PCR method. The results showed that cadmium inhibited cell proliferation at 0.1mM cadmium treated cells for 24 hours. The TNF-alpha mRNA was expressed in both control and cadmium treated cells but not IL-6 and IL-1 beta The mRNA levels of TNF-alpha were examined during 24 hours culture period, at different time points. The expression of TNF-alpha mRNA increased in both 0.01mM and 0.1mM cadmium treated cells, but did not show dose-response relationship. According to cadmium treated duration, expression of TNF-alpha mRNA was more decreases in 24 hours than 6 hours. The decreased levels of mRNA of TNF-alpha that cadmium suppresses iris production at the transcription level.

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