• IMMUNE NETWORK
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• v.20 no.3
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• pp.20.1-20.15
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• 2020

Memory CD8+ T cells in the immune system are responsible for the removal of external Ags for a long period of time to protect against re-infection. Naïve to memory CD8+ T cell differentiation and memory CD8+ T cell maintenance require many different factors including local environmental factors. Thus, it has been suggested that the migration of memory CD8+ T cells into specific microenvironments alters their longevity and functions. In this review, we have summarized the subsets of memory CD8+ T cells based on their migratory capacities and described the niche hypothesis for their survival. In addition, the basic roles of CCR7 in conjunction with the migration of memory CD8+ T cells and recent understandings of their survival niches have been introduced. Finally, the applications of altering CCR7 signaling have been discussed.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.345-350
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• 2005

Acute toxicities of five pharmaceutical products were evaluated with aquatic microbes, invertebrates, and fish. The test pharmaceuticals, i.e., cimetidine, carbamazepine, diltiazem, acetaminophene, and metformin have been often detected in aquatic environment, but theire cological hazard on receptors of various trophic levels has seldom been evaluated. In the present study, we conducted acute toxicity assays with a marine bacterium, Vibrio fischeri, an invertebrate, Daphnia magna, and a fish, Japanese medake (Oryzias latipes). In general, D. magna, showed the most sensitive response to the test chemicals. Diltiazem exhibited the lowest EC50 value after 96 hr of exposure at 7.6 mg/L, followed by cimetidine >acetaminophen > metformin = carbamazepine in an order of decreasing susceptibility. With the fish, diltiazem and carbamazepine showed the 96 hr EC50 values at 14.1${\sim}$35.4 mg/L while acetaminophen, cimetidine, and metformin did not cause 50% mortality at 100 mg/L. Similar pattern was noted with the Microtox Assay, with which the median effective concentrations for acetaminophen, cimetidine, and metformin were found at the range between 301.8 and 755.4 mg/L. Carbamazepine and diltiazem exposure to the microbes resulted in EC50 values around 50 mg/L. Predicted no effect concentrations (PECs) of these pharmaceuticals derived from the EC5O values obtained from this study, and predicted environmental concentrations (PECs) obtained from available literatures were utilized to estimate ecological risks of the test compounds. No test pharmaceuticals resulted in risk quotients (PEC/PNEC) greater than 1, which suggests no serious potential ecological concerns. It should be noted however that further studies including the refinement of PEC derivation, identification and toxicity assessment of the metabolites and/or their interactions with other stressors may be warranted to better understand the environmental consequences of the residual pharmaceutical discharge to the waterway.

• Environmental Mutagens and Carcinogens
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• v.22 no.4
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• pp.259-265
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• 2002

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were reported to be a potential carcinogen classified in the category of suspected endocrine disruptors. Most common human exposure to these compounds may occur with contaminated food. They may migrate into food from plastic wrap or may enter food from general environmental contamination. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of phthalates that possibly threaten the public health. Concern about their use has been mounting. To screen and elucidate the endocrine disrupting activity and their mechanism of phthalate analogues, first of all, E-screen assay was performed in MCF7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, only dibutyl phthalate (DBP) showed weak estrogenic activity. Also the yeast-based transcription assay to assess the interactions of DBP with the estrogen, androgen, and progesterone receptors was conducted. DBP in the concentration ranges from 10$^{-16}$ to 10$^{-11}$ M was active in the estrogen transcriptional assay, but it did not show the effect on $\beta$-galactosidase activity in the progesterone and androgen transcriptional assays. These data indicate that DBP shows estrogenic potential and can be classified as weak and/or suspected endocrine disrupting chemicals.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.193-193
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• 2003

Recent industrial society has human widely exposed to PAHs that are coming from the incomplete combustion of organic material as widespread environmental contaminants. Biological activities of PAHs are not known although PAHs are considered as carcinogens. The mechanism of action of PAHs has been studied extensively, however it is not clear how PAHs turn on CYPlAl in human breast cancer, Our laboratory have been studied the effect of PAHs in the human breast cancer cells, MCF-7. In this study, we examined the ZR-75-1, human breast cancer cells, as a new system to evaluate bioactivity of PAHs and to compare the PAHs action with that of MCF-7 cells. ZR-75-1 human breast cancer cell line is responsible to estrogen and progesterone. We have been able to establish long term culture system of this cells then used for the study to the effect of 13 different PAHs and environmental samples. We demonstrate that PAHs induced the CYP1A1 promoter and 7-ethoxyresorufin O-deethylase (EROD) activity in a concentration-dependent manner. RT-PCR analysis indicated that PAHs significantly up-regulate the level of CYP1A1 mRNA. Some of PAHs showed stronger stimulatory effect on CYP1 gene expression than TCDD Apparently, ZR-75-1 cells have Aryl hydrocarbon receptors (AhR), therefore it would be a good experimental tool to study the cross-talk between PAHs and steroid actions.

• Analytical Science and Technology
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• v.12 no.4
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• pp.265-272
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• 1999

A simultaneous profile analysis of 19 environmental estrogens, which act like estrogen and may effect the endocrine system by binding to hormone receptors or influencing cell signaling pathways, was attempted. The present method was based on the selected ion monitoring (SIM) mode of gas chromatography/mass spectrometry (GC/MS). It involves solid-liquid extraction, enzyme hydrolysis, liquid-liquid extraction and quantitative conversion into trimethylsilyl (TMS)-ether derivatives. Analytical recovery range was 47.6 ~ 99.5% and the RSD values of within-a-day and day-to-day test were 0.66 ~ 9.33%, 1.66 ~ 16.14%, respectively. The Korean reference values for the evaluation of environmental estrogen effects were established by this method.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.1
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• pp.34-39
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• 2017

The recent gradual increase in the energy demand is mostly met by fossil fuel, but the research on and development of new alternative energy sources is drawing much attention due to the limited fossil fuel supply and the greenhouse gas problem. This paper assesses the feasibility of producing fuel energy from a dewatered sewage sludge by microwave-induced pyrolysis with sludge char and graphite receptor. Both receptors produced gas, char, and tar in order from product amount. The gas produced for the sludge char receptor contained mainly hydrogen and methane with a small amount of light hydrocarbons. The graphite receptor generated higher gravimetric tar and generated higher light tar. Through the results, the product gas from the microwave processes of wet sewage sludge might be possible as a fuel energy. But the product gas has to be removed the condensable PAH tars.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.1 no.1
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• pp.19-33
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• 1997

The high oxidants, which occur the daily maximum concentrations in the afternoon, are transported into the other region via long range transport mechanisms or trapped within the shallow mixing boundary layer and then removed physically (deposition, transport by mountain wind, etc.) and chemically (reaction with local sources). Therefore, modeling formation of photochemical oxidants requires a complex description of both chemical and meteorological processes. In this study, as a part of air quality studies, we reviewed various aspects of photochemical modeling on the basis of currently available literature. The result of the review shows that the model is based on a set of coupled continuity equations describing advection, diffusion, transport, deposition, chemistry, emission. Also photochemical oxidant models require a large amount of input data concerned with all aspects of the ozone life cycle. First, emission inventories of hydrocarbon and nitrogen oxides, with appropriate spatial and temporal resolution. Second, chemical and photochemical data allowing the quantitative description of the formation of ozone and other photochemically-generated secondary pollutants. Third, dry deposition mechanisms particularly for ozone, PAN and hydrogen peroxide to account for their removal by absorption on the ground, crops, natural vegetation, man-made and water surfaces. Finally, meteorological data describing the transport of primary pollutants away from their sources and of secondary pollutants towards the sensitive receptors where environmental damage may occur. In order to improve our present study, shortcomings and limitation of existing models are pointed out and verification process through observation is emphasized.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5445-5450
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• 2012

Although benign uterine leiomyomata (LMA) is the most common reproductive tumor in premenopausal women, its etiology is largely unknown. We aimed in the present study to demonstrate the potential role of environmental factors with estrogenic activity in tumor etiology by focusing on the role of aryl hydrocarbon receptor (AhR) which mediates the effects of many environmental endocrine disruptors and contributes to the loss of normal ovarian function in polluted environments. This case-control study aimed to compare the interactions between AhR and lifestyle factors in a clinical setting for the first time among 138 newly diagnosed LMA patients and 138 normal controls who lived in Tehran and Mashhad, respectively, during the last 10 years. To conduct immunohistochemical studies using appropriate monoclonal antibodies, 30 cases were selected retrospectively from 2009-2011 from the pathology departments of two university hospitals in Tehran. Although the levels of sex steroid receptors were similar in adjacent myometrium and uterine leiomyomas of all cases, AhR was significantly overexpressed (p=0.034, OR=1.667) in uterine LMA and this overexpression was correlated with living in Tehran [(p=0.04, OR=16 (1.216-210.58)], smoking[P=0.04, OR=2.085 (1.29-3.371)], living near polycyclic aromative hydrocarbon producing companies [p=0.007, OR=2.22 (1.256-3.926)] and eating grilled meat [p=0.042, OR=1.28 (1.92-3.842)]. Our study contributes to the understanding of the effects of EDCs on AhR levels as well as women's health and points out possible risk factors for the development and growth of uterine LMA. It seems that the development of LMA could be the result of interactions between hormonal and environmental factors.

• Environmental Mutagens and Carcinogens
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• v.23 no.2
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• pp.45-50
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• 2003

Biological activities of PAHs are not known although PAHs are considered as carcinogens. Recent industrial society has human widely exposed to PAHs (polynuclear aromatic hydrocarbons) that are comming from the incomplete combustion of organic material as wider spread environmental contaminants. Our laboratory have been studied the effect of PAHs in the human breast cancer MCF-7 cells. In this study, we examined the human breast cancer MCF-7 cells as a new system to evaluate bioactivity of PAHs. We have selected 13 PAHs to examine bioassay using CYP1A1-luciferase reporter gene expression system where CYP1A1 1.6 Kb 5flanking region DNA was cloned in front of luciferase reporter gene and this plasmid was transfected into MCF-7 cells transiently. This cells then used for the study to observe the effect of PAHs. We demonstrated that PAHs induced the CYP1A1 promoter, CYP1A1 mRNA and 7-ethoxyresolufin O-deethylase (EROD) activities in a concentration-dependant manner. None of PAHs that we have tested showed stronger stimulatory effect on CYP1 gene expression than TCDD. Benz(a)anthracene and benzo(b)fluoranthene were weak responders to CYP1A1 promoter activity stimulation, CYP1A1 mRNA and EROD induction in MCF-7 cells and these chemicals seemed to respond less either CYP1A1 mRNA or EROD than CYP1A1 promoter activity. Benzo(k)fluoranthene, chrysene, and dibenzo(a, h)anthracene showed strong response to CYP1A1 promoter activity stimulation, CYP1A1 mRNA increase and also EROD induction in MCF-7 cells. Results of dose response study suggested that two strong responding PAHs, such as benzo(k)fluoranthene and dibenzo(a, h)anthracene might be mediated through Aryl hydrocarbon receptors system in MCF-7 cells.

• Journal of Soil and Groundwater Environment
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• v.20 no.6
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• pp.19-27
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• 2015

Permissible soil concentrations for explosives (i.e., TNT and RDX) and heavy metals (i.e., Cu, Zn, Pb, and As) heve been derived from human risk and ecotoxicity, respectively. For TNT and RDX, human risk based-permissible soil concentrations were determined as 460 mg-TNT/kg-soil and 260 mg-RDX/kg-soil. Ecotoxicity based-permissible soil concentrations for Cu and Zn were determined from species sensitivity distribution (SSD) and uncertainty factor of 1 to 5, yielding 18.0-40.0 mg-Cu/kg-soil and 46.0-100 mg-Zn/kg-soil. For Pb and As, ecotoxicity data were not enough to establish SSD so that a deterministic method was used, generating 13.8-30.8 mg-Pb/kg-soil and 2.10-4.60 mg-As/kg-soil. It is worth noting that the methodology used to derive permissible concentrations in soil can differ depending on ecotoxicity data availability and socio-economic situations, which results in different permissible concentrations. The permissible concentrations presented in this study have been derived from conservative assumptions for exposure parameters, and thus should be considered as soil standards. In the light of remediation and pollution management of a site of interest, the site-specific and receptor-specific permissible soil concentrations should be derived considering potential receptors, current and future land use, background concentrations, and socio-economic consultation.