Proceedings of the Korean Society of Toxicology Conference (한국독성학회:학술대회논문집)
Korean Society of Toxicology & Korea Environmental Mutagen Society
- Semi Annual
Domain
- Health Sciences > Toxicology/Safety Management Base Technology
2001.05a
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Increased expression of inducible cyclo-oxygenase (COX-2) is associated with a wide variety of tumours. In addition inhibitors of COX have shown a great deal of promise in vitro and in animal models as potential anti-tumour therapies. COX enzymes utilise the substrate arachidonic acid to produce prostaglandin (PO)H
$_2$ , the precursor to all the prostanoids.(omitted) -
Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase II activities. Genistein has been shown to have anticancer proliferation, differentiation and chemopreventive effects. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of p53-null human prostate carcinoma cells.(omitted)
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Many epidemiological studies have revealed that the use of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) can reduce the risk of colon cancer. Since the well-documented pharmacological action of aspirin and other NSAIDs is the inhibition of cyclooxygenase [COX, the rate-limiting enzyme in prostaglandin (PG) biosynthesis], it has been inferred that the beneficial effect of NSAIDs may be mediated through the inhibition of PG biosynthesis.(omitted)
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Apoptosis is characterized by DNA fragmentation, chromatin condensation and plasma membrane blebbing. These apoptotic processes have been mainly associated with genetic mechanisms. Recently, these processes have been also associated with mitochondrial events that include the release of cytochrome c and Diablo/SMAC by modulation of mitochondrial membrane permeability.(omitted)
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Under low oxygen tension, cells increase the transcription of specific genes that are involved in angiogenesis, erythropoiesis and glycolysis. Hypoxia-induced gene expression primarily depends on the stabilization of the subunit of Hypoxia-Inducible Factor-1 (HIF-1), which acts as a heterodimeric transactivator.(omitted)
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Human Thioredoxin (TRX) with with redox-active dithiol (C-C-Y-C-) in the active site has been cloned as adult T cell leukemia derived factor produced by HTLV-I transformed cells. Thioredoxin (TRX) is one of the major components of the thiol-reducing system and plays multiple roles in cellular processes such as proliferation, apoptosis and gene expression.(omitted)
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All that is presently known about the actions of 8-hydroxyguanine (8-oxoguanine; oh
$^{8}$ Gua) in DNA is that it harms genetic integrity. This is even speculation based upon scattered in vitro experimental data such as the mismatch of oh$^{8}$ Gua with A in stead of C and the GC longrightarrow TA transversion observed in the DNA polymerase reaction using an oh$^{8}$ Gua containing oligonucleotide.(omitted) -
Howard P. Glauert;Mason, Karen-Calfee;Yixin Li;Zijing Lu;Vani Nilakantan;Job Tharappel;Larry W. Robertson;Brett T. Spear 94
The purpose of these studies was to determine if hepatic tumor promoters could activate the transcription factor NF-kB, the mechanism of this activation, and whether activation of NF-kB is important in the carcinogenic process. We first demonstrated that the administration of the peroxisome proliferator ciprofibrate increases the hepatic DNA binding activity of NF-kB in rats and mice.(omitted) -
The phase II detoxifying enzymes are inducible by a variety of compounds and play an essential role for the protection of cells. Many of chemoprotective agents trigger cellular signals for the phase II enzyme induction, which subsequently activate gene transcription through ARE activation.(omitted)
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During the course of pharmacokinetic studies of SM 12502 which was underdevelopment as an anti-PAF agent, we found that there were three subjects who showed a slow metabolic phenotypeinits pharmacokinetics. Since this compound was oxidized specifically by CYP2A6, we analyzed the genes for CYP2A6 of the three subjects. The results indicated that the three subjects possessed the whole CYP2A6 gene deletion genotype.(omitted)
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Lee, Jong-Kwon;Lee, Eun-Hee;Kim, Ju-Hwan;Hong, Jin-Tae;Kim, Hyung-Soo;Park, Ki-Sook;Ahn, Kwang-Soo;Cho, Dae-Hyun;Lee, Sun-Hee 109
In order to evaluate the neutral red uptake assay as an alternative method for phototoxicity test, we compared the potential of phototoxicity in vitro in cultured human fibroblasts and 3T3 fibroblast cells derived from Balb/c mice. Both fibroblasts were exposed to various known phototoxic chemicals (promethazine, neutral red, chlorpromazine, chlortetracycline, amiodarone, bithionol, 8-methoxypsoralen) and non-phototoxic chemical (ammonium laureth sulfate) and irradiated with 5 J/cm$^2$ of UVA.(omitted) -
Lee, Eun-Hee;Hong, Jin-Tae;Lee, Jong-Kwon;Kim,Yong-Kyu;Park, Ki-Sook;Jung, Kyoung-Mi;Kwan, Jung-Hai;Lee, Sun-Hee;Yang, Ki-Hwa;Chung, Soo-Youn 110
To compare skin irritation and cytotoxicity of anti-wrinkle agents, we examined skin irritation of six anti-wrinkle agents (ascorbic acid, glycolic acid, all trans-retinoic acid, ginseng extract, retinol, EB) in New Zeland white rabbit.(omitted) -
The cytokinesis-block micronucleus assay have been emerged as one of the preferred method for assessing chromosome damage. Micronucleus are small, extranuclear bodies that are formed in mitosis from acentric chromosomal fragments or chromosome that are not included in each daughter nuclei.(omitted)
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The genetic polymorphism of GSTM1, GSTT1, GSTP1, NATII and CYP1A1 genes among 33 asthma patients and 66 controls were investigated to find the association between the polymorphism and the risk of asthma. The frequency of the GSTT1 null genotype was slightly higher in asthma patients than that in the control, but this difference was not significant.(omitted)
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Kim, Hyung-Soo;Juno H. Eom;Kim, Jin-Ho;Chung, Seung-Tae;Park, Jae-Hyun;Kang, Sun-Kyung;Kim, Dong-Sub 113
The popliteal lymph node assay (PLNA) was proposed to predict autoimmunogenic potential of xenobiotics. This study was conducted to establish the popliteal lymph node assay(PLNA) and to investigate the measurement of lymphocyte subsets can be utilized as an additional parameter in PLNA.(omitted) -
Juno H. Eom;Chung, Seung-Tae;Kim, Jin-Ho;Park, Jae-Hyun;Chung, Hyung-Jin;Hwang, In-Chang;Kim, Dong-Sup;Kim, Hyung-Soo 114
Di-n-butyl phthalate (DBP) is not only a plasticizer and solvent used in industry but also one of endocrine disruptor chemicals, a low level contaminant found in a wide variety of different media ranging from drinking water to infant formulae. To evaluate the cytotoxic function of NK cells in mice after contact with DBP, C57BL/6 female mice were orally dosed with di-n-butyl phthalate (250, 500, or 750 mg/kg body weight) for 14 consecutive days, and the control mice were administered vehicle (corn oil).(omitted) -
Regular green tea consumption has been associated with a reduced risk of cancer, partly via antioxidant effects of green tea in protecting cellular components against free radical. In the present study, we evaluated the effect of green tea extract (GTE) on oxidative damage to DNA in CHL cells.(omitted)
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The alkaline Comet assay has been used with increasing popularity to investigate the level of DNA damage in terms of strand breaks and alkaline labile sites in biomonitoring studies within the last decade in western countries.(omitted)
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The aim of this study was to assess a possible alternative method as replacement for in vivo phototoxicity test. The 3T3 mouse fibroblast neutral red uptake phototoxicity assay (3T3 NRU PT assay) is a screening method for studying DNA or cellular damage. Photohemolysis assay is a mechanistic study for investigating oxygen-dependent membrane damage.(omitted)
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To find out localization of mercury in male reproductive system, adult male mice were injected subcutaneously with methyl mercuric chloride (1mg/mouse) once per week for 20, 40 and 70 days. The experimental periods later, animals were sacrificed by transcardial perfusion and organs were removed, dehydrated, and embedded in paraffin.(omitted)
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Traditional herbal medicines(HM) are frequently taken in combination with conventional medications in Korea, but few reports have been addressed to herb-drug interaction. We assessed the inhibitory potential of 15 commonly used HMs in Korea on CYP450 isoforms.(omitted)
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Exposure of testis to 2-BP is known to cause degeneration of male germ cells. However, the mechanism underlying this process is poorly understood. The objective of this study was to determine whether 2-BP induces apoptosis during onset of toxicity in germ cells of male Sprague-Dawley rats.(omitted)
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Lee, Jeong W.;Ki D. Shin;Shin W. Cha;Kim, Jong-C.;Kim, Eun J.;Sang S. Han;Tae C. Jeong;Woo S. Koh 121
Thioacetamide has been known to cause immune suppression. In this report we studied the role of metabolic activation by flavin-containing monooxygenase in the thioacetamide-induced immune response. To determine whether the metabolites of thioacetamide produced by flavin-containing monooxygenase result in the immunosuppression, methimazole, a flavin-containing monooxygenase inhibitor, was used to block the flavin-containing monooxygenase pathway.(omitted) -
Flupyrazofos is a new type of pyrazole organophosporus insecticide, which has a high activity against the diamond-back moth (Plutella xylostella). The potential of this agent to induce developmental toxicity was investigated in the Sprague-Dawley rat.(omitted)
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The distribution of necrotic and apoptotic neural cells, and expression of astrocytic glial fibrillary acidic protein (GFAP) in the brain of rats poisoned intraperitoneally with diisopropylfluorophosphate were investigated. Pyridostigmine bromide (0.1 mg/kg) and atropine methylnitrate (20 mg/kg), which are centrally inactive, were treated intramuscularly 30 min and 10 min, respectively, before diisopropylfluorophosphate (4 - 10 mg/kg) poisoning to reduce the mortality.(omitted)
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Tetrahydropapaveroline(THP), a dopamine-derived 6,7-dihydroxy-l-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydrosioquinoline, has been suspected as a possible dopaminergic neurotoxin to elicit Parkinsonism. Autoxidation or monoamine oxidase-mediated oxidation of THP and subsequent generation of reactive oxygen species (ROS) may contribute to the degeneration of dopaminergic neurons induced by this isoquinoline alkaloid.(omitted)
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B cell has been identified as the sensitive cellular target responsible for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) -induced immune suppression. In isolated cell systems, the differentiation of B cells into antibody secreting plasma cells is believed to be inhibited by TCDD. We also have previously demonstrated IgM secretion was suppressed by TCDD in LPS-activated murine B cell line, CH12.LX.(omitted)
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Kim, Hyeon-Yeong;Lee, Jun-Yeon;Lim, Cheol-Hong;Chung, Yong-Hyun;Han, Jung-Hee;Jeong, Jae-Hwang;Lee, Sung-Bae;Jhoon, Yoon-Sook;Lee, Yong-Muk 126
The purpose of this study was to investigate the acute(4 hrs) and repeated-dose(6 hrs a day, 5 days a week, 8 weeks) toxic effects of 1-bromopropane(1-BP) on Sprague-Dawley (SD) rats which were treated by inhalation. The results were as follows ;(omitted) -
Single-dose toxicity of a new phosphodiesterse inhibitor-5, DA -8159, was studied in rats via oral and intravenous routes and in mice via oral route. In addition, genotoxic potential of DA-8159 was investigated by using of the battery of test; reverse mutation test on bacteria, chromosomal aberration test on cultured mammalian cells and micronucleous test on mice.(omitted)
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Toxic effects of a new phosphodiesterse-5 inhibitor, DA-8159, were investigated in Sprague-Dawley rats by repeated oral administration. Four groups of 10 male and 10 female rats were treated with DA-8159 at a dose of 0, 40, 80, or 320 mg/kg/day for 4 weeks.(omitted)
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Alkylphenol ethoxylates have been used extensively as nonionic surfactants in industrial processing, household and institutional cleaning products. They are apparently degraded microbially to alkylphenol. Alkylphenol has been shown to possess estrogenic properties and, therefore, is an 'endocrine disrupter' that has significantly influence on sexual and reproductive development.(omitted)
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The commercially available paclitaxel product, Taxol
$\circledR$ is currently formulated in a vehicle containing approximately a 1:1 v/v mixture of polyoxyethylated castor oil (Cremophor EL) and ethanol. Cremophor EL, a commonly used surfactant for lipophilic compounds, has been associated with many issues, such as adverse effects particularly following rapid administration, stability with the possibility for drug precipitation upon dilution, and filtering requirements.(omitted) -
Two 6-(fluorinated-phenylamino)-5, 8-quinolinedione derivatives, OQ21 and OQ1, were newly synthesized as potent inhibitors of endothelial-dependent vasorelaxation. The purpose of the present study was to investigate the effect of OQ21 and OQ1 on different types of vasorelaxation and to pursue their action mechanisms. (omitted)
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To understand mechanism of benzoquinone-induced cytotoxicity, the roles of ATP and calcium in platelet toxicity and morphology changes was investigated. Using scanning electron microscopy, morphological changes to platelets following l,4-benzoquinone exposure consisted of membrane blebbing at 5 min which was significantly different from shape changes (pseudopod formation) observed in response to physiological agonists.(omitted)
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Involvement of p38 Mitogen-Activated Protein Kinase in the Cell Growth Inhibition by Sodium ArsenitePark, Jung-A;Kim, Ja-Young;Kim, Tae-Hwan;Yoo, Young-Do;Yoo, Seong-Yul;Cho, Chul-Koo;Lee, Yun-Sil;Lee, Su-Jae 133
It is well known that p38 mitogen-activated protein kinase (p38MAPK) participates in cellular responses to mitogenic stimuli, environmental and genotoxic stresses, and apoptotic agents. Although there are several reports on p38MAPK in relation to cell growth and apoptosis, the exact mechanism of p38MAPK-mediated cell growth regulation remains obscure.(omitted) -
Cutting oils are complex mixtures of hydrocarbons, comprising of certain fractions of mineral oil, which are being frequently used as lubricating and heat transferring agents in various machine and tool industries. We investigated an acute and 2 weeks repeated irritation studies of two cutting oils (Cimperial 1010 as water-soluble cutting oil, and MSN 120 as insoluble cutting oil) using guinea pigs.(omitted)
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Jisung Ryu;Lee, Chul-Woo;Park, Eung-Roh;Nam, Seong-Sook;Nam, Kyu-Chan;Rhu, Hong-Il;Jeon, Seong-Hwan;Na, Jin-Gyun;Park, Kwangsik 135
Mating behavior and reproductivity of male fish were studied as an in vivo screening method of endocrine disruptors. Male medaka (Oryzias latipes) were exposed to 17$\beta$ -estradiol at nominal concentrations of 2 and 20$\mu\textrm{g}$ /L for 14 days.(omitted) -
MDA(malondialdehyde) is the parameter of lipid peroxidation. The change of MDA value was investigated in normal and in fibrotic rats by bile duct ligation and scission operation. In order to know how does lipid peroxidation play under the fibrotic condition we studied whether MDA as lipid peroxidation marker has correlation with one of the liver fibrotic parameters.(omitted)
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Oran-Kwon;Kwack, Seung-Jun;Shin, Jae-Ho;Kim, Soon-Sun;Sohn, Kyung-Hee;Kim, So-Hee;Lee, Rhee-Da;Kim, Byung-Ho;Park, Chul-Hoon;Ha, Won-Kwang;Park, Kui-Lea 138
The purpose of the present studies was to investigate the effects of subchronic paternal treatment of cyclophosphamide (CP) and acrolein on male fertility and early embryonic development. Two approaches were pursued. The first was to perform in vivo test for observing the adverse effects of CP and acrolein on the function og male reproductive system and pregnancy outcome.(omitted) -
Arctigenin and demethyltraxillagenin, dibenzylbutyrolactone lignans, are phenylpropanoid plant metabolites with antioxidative and anti-inflammatory activities. The effects of arctigenin and demethyltraxillagenin on the nuclear factor-kB (NF-kB)-mediated inducible nitric oxide synthase (iNOS) gene expression were studied in Raw264.7 cells.(omitted)
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THE ESSENTIAL ROLE OF PHOSPHATIDYLINOSITOL 3-KINASE IN THE INDUCTION OF MICROSOMAL EPOXIDE HYDROLASEWe have shown that PI3-kinase played an essential role in the ARE-mediated rGSTA2 induction by oxidative stress following sulfur amino acid deprivation (SAAD) (Kang et al., Mol. Pharmacol., 2000). Microsomal epoxide hydrolase (mEH), which detoxifies a variety of epoxide intermediates produced from various xenobiotics, is inducible by oxidative stress.(omitted)
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Starvation stimulates multiple signaling pathways, which lead to extensive metabolic alterations Starvation potentiates the hepatotoxicity of a variety of small molecules including chlorinated hydrocarbons and nitrosamines through the induction of CYP2E1. A change in CYF2E1 expression during starvation may also alter the pharmacokinetic profiles of xenobiotics.(omitted)
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This study was undertaken to explore the effect of SN20 and SQ compounds, which were synthesized by UL-Biotech on the lowering of level of the blood cholesterol by (Seoul, Republic of Korea), and the mechanism of them. The lowering effect of SN20 and SQ on total blood cholesterol were determined in rats fed hyperlipodic powder diets containing 1% cholesterol and 0.5% cholic acid with warious concentrations of SN20 or SQ for 1 week to 4 weeks.(omitted)
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Human cytochrome P450 (CYP or P450) 3A4 (CYP3A4) is the most abundant among P450s in human liver. We previously reported that the expression of CYP3A4 in membranes prepared from E. coli coexpressed the bicistronic construct of CYP3A4 and NADPH-P450 reductase with cytochrome b
$_{*}$ (b5) was showed 20-60% higher than that in membranes from E. coli expressed only the bicistronic construct with culturing longer times (48-72h).(omitted) -
Inappropriate up-regulation of cyclooxygenase-2 (COX-2) has been implicated for pathogenesis of various types of human cancer. COX-2 expression is known to be regulated by the eukaryotic transcription factor NF-
$textsc{k}$ B. In an attempt to link the NF-$textsc{k}$ B activation and COX-2 induction, we have examined the kinetics of phorbol ester-induced activation of NF-$textsc{k}$ B and COX-2 expression in the immortalized human breast epithelial cell line (MCF10A).(omitted) -
Park, Kwang-Kyun;Chung, Won-Yoon;Kim, Hee-Ok;Kim, Hee-Kyong;Park, Min-Ah;Kim, Mi-Jeong;Sohn, Joon-Hyung 145
Xanthorrhizol is a sesquiterpenoid isolated from Curcuma xanthorrhiza Roxb. (Zingiberaceae) that has been traditionally used in Indonesia for dietary and medicinal purposes. In our studies to evaluate the cancer chemopreventive potential, xanthorrhizol inhibited the mutagenesis induced by reactive oxygen species in Sa;monella typhimurium TA 102 in a dose-related manner and decreased significantly the incidence and the multiplicity of skin tumors initiated by 7, 12-dimethylbenz[$\alpha$ ]anthracene and promoted by 12-Ο-tetradecanoylphorbol-13-acetate at 19 weeks.(omitted) -
Gastroesophageal reflux disease (GERD) is multifactorial in etiology and is characterized by movement of acid and other noxious substances from the stomach into the esophagus. The most severe histologic consequence of chronic gastroesophgeal reflux is Barrett's esophagus, which has been considered as a premalignant condition often leading to the formation of adenocarcinoma of esophagus.(omitted)
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Shin, J.H.;Kim, H.S.;Moon, H.J.;Kang, I.H.;Kim, T.S.;Seok, J.H.;Kim, I.Y.;Nam, S.Y.;Park, K.L.;Han, S.Y. 147
To establish a test protocol for the rodent 20-day thyroid/pubertal assay, we dosed flutamide(fl), a non-steroidal androgen antagonist to intact male SD rats from postnatal day 33 for 20 days, and examined several reproductive endpoints for assessing the sensitivity of a list of parameters for detecting endocrine-related effects of endocrine-disrupting chemicals.(omitted) -
Estrogen is known to exert potent vasodilating effects accompanied with an elevation of cyclooxygenase-2 (COX -2) expression. Structurally similar compounds, isoflavones, have shown in our previous study that they stimulate COX-2 of the heart of animals fed soy isoflavones.(omitted)
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Park, Ji-Young;Shon, Ji-Hong;Yoon, Young-Ran;Kim, Kyung-Ah;Kim, Min-Jung;Shim, Ju-Chul;Cha, In-June;Shin, Jae-Gook 149
Cytochrome P450 (CYP) 2D6 and CYP3A4 have been reported to be involved in the major metabolic pathways and formations of neurotoxic metabolites (HPP$\^$ +/, RHPP$\^$ +/) from haloperidol (HAL). However, no in vivo study has been addressed to the involvement of both CYP isoforms on the formation of toxic HAL metabolites.(omitted) -
Maeng, Seung-Hee;Kim, Hyun-Young;Lim, Cheol-Hong;Lee, Jong-Yoon;Lee, Yong-Mook;Chung, Ho-Keun;Chung, Hai-Won;Yu, Il-Je 150
To investigate the genotoxic effect of 1, 1-dichloro-1-fluoroethane, which was widely used as a cleaning solvent at the electronic part industry, the micronucleus frequencies were recorded by examining polychromatic erythrocytes in bone marrows of the rodents exposed to it with different routes.(omitted) -
Seung-Hee Maeng;Il-Je Yu;Hyun-Young Kim;Cheol-Hong Lim;Jong-Yoon Lee;Kwon-seob Lee;Yong-Mook Lee;Ho-Keun Chung;Hai-Won Chung 151
According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process. We measured one kind of oxidative DNA damages, 8-hydroxydeoxyguanosine (8-OHdG) and its repair activities as an indicators of cellular oxidative stress in rat lungs by the repeated inhalation exposure to sodium chromate.(omitted) -
Curcumin, a yellow coloring ingredient of turmeric (Curcuma longa L., Zingiberaceae), has been shown to inhibit experimental carcinogenesis and mutagenesis, but molecular mechanisms underlying its chemopreventive activities remain unclear.(omitted)
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Nitric oxide (NO) has multifaceted roles in carcinogenesis. Besides acting as an initiator, NO may also playa role in the promotional stage of tumorigenesis or neoplastic transformation. In line with this notion, our previous studies have revealed that the tumor promotor phorbol ester induces expression of inducible nitric oxide synthase (iNOS) and NO production in mouse skin.(omitted)
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Haikwan Jung;Park, Miyoung;Miok Eom;Hoil Kang;Park, Misun;Seungwan Jee;Taikyung Ryeom;Hyeyoung Oh;Kim, Okhee 154
2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin(TCDD), a prototype of many halogenated aromatic hydrocarbons, is a ubiquitous, persistent environmental contaminant and the most powerful carcinogen categorized by IARC. Despite extensive research, the mechanisms of TCDD-induced carcinogenesis are poorly understood, and its carcinogenic potential in human is not clear.(omitted) -
Acute cadmium exposure has been shown to increase sodium reabsorption in kidney through increase in aldosterone secretion in human and rodents. However, the antinatriuresis is not completely explained by hyperaldosteronism. Moreover, it is still controversial that the increase in plasma aldosterone concentration is mediated by the renin-angiotensin-aldosterone system(RAAS).(omitted)
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Involvement of p38 mitogen-activated protein kinase in H-ras-induced invasive phenotype and motilityOne of the most frequent defects in human cancer is the uncontroled activation of the ras-signaling pathway. We have previously shown that H-rasm but not N-ras, induces an invasiveness. Here, we show that cell motility was greatly increased by H-ras, but not by N-ras, suggesting that H-ras-induced invasive phnotype involves enhanced cell motility.(omitted)
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Capsaicin (8-methyl-N-vanillyl-6-nonenamide), the principal pugent ingredient found in hot red pepper, has been recently known to have anticarcinogenic or chemopreventive properties. In the previous study, we showed that capsaicin selectively induces apoptosis in H-ras MCF10A cells.(omitted)
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The cause of Parkinson's disease (PD) is largely unknown. However, free radical toxicity may playa role in the degeneration of substantia nigra, which is the major focus of pathological damages in PD. Recently, a neuroprotective effect of nicotine in PD has been suggested.(omitted)
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The phthalates have been shown to produce hepatic peroxisome proliferation and certain peroxisome proliferators (PPs) are also known to increase the incidence of liver tumors in rodents. In this study we investigated the correlation between oxidative injury, changes in peroxisomal and microsomal enzymes and tumor formation in PP-treated rats.(omitted)
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We recently reported that, 2-chloro-3-(4-hexylphenyI)-amino-l, 4-naphthoquinone(NQ304), a naphthoquinone derivative, had potent inhibitory effects on the platelet aggregation in vitro and thrombosis in vivo. Furthermore, we reported the antiplatelet mechanism of NQ304 by the reduction of the thromboxane A2 formation, inhibition of adenosine triphosphate release and intracellular calcium mobilization.(omitted)
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Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an antioxidant selenoenzyme which interacts directly with and diminishes peroxidized phospholipids, cholesterol and cholesteryl ester in tissues. PHGPx activity appears in most tissues, but is especially high in testis. In testis, PHGPx level decreases in hypophysectomized rats but is partially restored after gonadotropin treament.(omitted)
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Selenium is an essential micronutrient for mammals and its biological functions are mediated by a selenoprotein. The mitochondrial capsule selenoprotein (MCS) is a selenoprotein that is necessary for the maintenance and stabilization of the sperm mitochondrial membrane.(omitted)
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Selenium (Se) is an essential micronutrient for mammals and its biological functions are mediated by selenoprotein. In tissues, Se is incorporated into the selenoprotein by recognition of the UGA codon as a stop codon for selenoprotein. Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an antioxidant selenoprotein that belongs to the superfamily of selenium-dependent peroxidase.(omitted)
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This study investigated expression pattern of PHGPx gene in male rat reproductive organs exposed to 17
$\beta$ -estradiol. First, in view of quantitative change, the exposure to 17$\beta$ -estradiol for 1 week increased PHGPx mRNA level in testis and prostate. PHGPx mRNA level in epididymis decreased weakly as compared to control group.(omitted) -
Genistein, a soybean-originated isoflavone, is an anticancer agent preventing various cancers including prostate, uterus, and mammary gland cancers. However, recently, genistein has been classified into a potential endocrine disruptor, because it binds to estrogen receptors and causes reproductive disturbances in some animals.(omitted)
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Kim, Eun-Joung;Jung, Kyoung-Mi;Park, Ki-Sook;Oh, Jae-Ho;Song, Chi-Won;Chung, Soo-Youn;Hong, Jin-Tae 167
Peroxisome proliferator-activated receptors(PPARs) are member of the neuclear hormone receptor superfamiliy of ligand-dependent transcription factors that heterodimerizes with the retinoid X receptor to function as a transcriptional regulator. They are divided into three subtypes(PPAR-$\alpha$ ,$\beta$ and${\gamma}$ ).(omitted) -
Hong, Jin-Tae;Oh, Jae-Ho;Jung, Kyoung-Mi;Lee, Eun-Hee;Park, Ki-Sook;Song, Chi-Won;Jung, Hai-Kwan;Lee, Myung-Koo;Yang, Ki-Hwa;Chung, Soo-Youn 168
The mycotoxin, ochratoxin A (OTA) has been known to induce microcephaly in animals and in vitro whole embryo. Cytotoxic effect and inhibition of cell differentiation were proposed as underlying mechanisms responsible for OTA-induced microcephaly.(omitted) -
The phthalates have been shown to produce hepatic peroxisome proliferation and certain peroxisome proliferators (PPs) are also known to increase the incidence of liver tumors in rodents. In this study we investigated the correlation between oxidative injury, changes in peroxisomal and microsomal enzymes and tumor formation in PP-treated rats.(omitted)