The nervous system consists of two types of cells, which are neurons and glial cells. Among the glial cells, oligodendrodendrocytes and schwann cells form myelin sheaths in the central nervous system (CNS) and the peripheral nervous system (PNS), respectively. The major function of myelin in vertebrates is to insulate axonal and help action potential travel faster.(omitted)

Antioxidant responsive element (ARE) mediates the transcriptional activation of the genes encoding phase II drug metabolizing enzymes and antioxidative stress genes. The ARE consensus sequence shows high similarity to NF-E2 binding sequence, a cisacting erythroid gene regulatory element.(omitted)

Mass spectrometric study of oxidant damage: Generation of endogenous oxidizing species have been implicated in the pathogenesis of a wide variety of diseases from cancer to Alzheimer's Disease to Inflammatory bowel diseases. Antioxidant compounds may therefore be useful in treating or preventing these diseases.(omitted)

Embryonic prostaglandin H synthases (PHSs) and lipoxygenases bioactivate xenobiotics (phenytoin, thalidomide, benzo[a]pyrene) to free radical intermediates that initiate reactive oxygen species (ROS) formation, which oxidatively damage cellular macromolecules and/or alter signal transduction.(omitted)

This study was done to examine the benzene induced chromosomal aberrations and also the influence of genetic polymorphism(GSTM1, GSTT1, GSTP1, NAT2, NQO1, CYP2E1 and CYP1A1) on the chromosomal aberrations. In total, 82 benezene exposed workers and 76 matched controls were examined.(omitted)

According to the epidemiological studies in chromium workers, hexavalent chromium is associated with the risk of lung cancer. Genotoxicity such as chromosome aberration, and cellular oxidative damages by reactive oxygen species produced by hexavalent chromium exposure may play an important role in the carcinogenesis process.(omitted)

To investigate the disease and recovery process of pneumoconiosis induced by welding-fume exposure, a lung fibrosis model was established by building a stainless steel arc welding fume generation system and exposing male Sprague-Dawley rats for 90 days.(omitted)

Arsenic (As) is a ubiquitous element found in several forms in foods and environmental media, such as soil, air, and water. The primary route of human exposure is through ingestion of arsenic-contaminated food and drinking water. The predominant form of arsenic in drinking water is inorganic arsenic, which is both highly toxic and readily bioavailable.(omitted)

Thimerosal 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 are occurred in unborn and newborn babies.(omitted)

Thioacetamide has been known to cause immune suppression. The object of the present study is to investigate the role of metabolic activation by flavin- containing monooxygenases (FMO) in thioacetamide-induced immune response. To determine whether the metabolites of thioacetamide produced by FMO causes the immunosuppression, methimazole (MMI), an FMO inhibitor, was used to block the FMO pathway.(omitted)

Ethyl 3-(4'-geranyloxy-3-methoxyphenyl)-2-propenoate (EGMP) and ferulic acid (FA) have been shown to inhibit development of aberrant crypt foci (ACF) in the azoxymethane (AOM)-treated rat colon. In the present study, inhibitory effects of EGMP and FA on the post-initiation stage of AOM-induced colon carcinogenesis were studied in male ddY mice.(omitted)

Two types of normal human breast epithelial cells (HBECs) have already been established and characterized. Type I HBECs are deficient in gap junctional intercellular communication and are capable of anchorage-independent growth and of expressing luminal epithelial cell markers, a variant estrogen receptor (ER), and stem cell characteristics.(omitted)

Ras expression has been suggested as a marker for tumor aggressiveness of breast cancer including the degrees of invasion and tumor recurrence. Expression of H-, K-, and N-ras is regulated in a tissue-specific manner and during development, indicating that ras proteins may have different cellular functions.(omitted)

Microsomal epoxide hydrolase (mEH), an epoxide detoxifying enzyme and putative cell surface autoantigen, is inducible by xenobiotics and by certain pathophysiological conditions. The present study was designed to determine mEH expression in H4IIE cells during cell death initiated by sulfur amino acid deprivation (SAAD) and to identify the signaling pathway for the enzyme induction.(omitted)

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, and many of their toxic effects, including their immunotoxicities, are mediated by the activation of aryl hydrocarbon receptor (AhR). We previously reported that Aroclor 1254, one of the most widely used PCB mixtures, increased DNA fragmentation in mouse spleen cells, suggesting that apoptosis was correlated with the immunotoxicity of PCB (Yoo et al., 1997).(omitted)

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of cytokines. The presence of oncogenic ras has been associated with sustained induction of COX-2, which confers resistance to apoptosis. Contrary to the above notion, we found that MCF10A-ras cells treated with an anti-tumor agent, ET-18-O-$CH_3$, underwent apoptosis as revealed by proteolytic cleavage of poly(ADP-ribose)polymerase, pro-caspase 3 activity, and TUNEL staining, while the same treatment caused an increased expression of COX-2 as well as the elevated production of prostaglandin E$_2$(PGE$_2$).(omitted)

The recent development of cDNA microarray or cDNA chip technology has made it possible to analyze the expression of thousands of genes at once. In present study, we made radioresistant clones (#1 and #4) from NIH3T3 cells which are not tumorigenic and we identified 4 genes using microarray system, cdk6, cdc25B, mdm-2 and nidogene, which were altered in radiaiton resistanct NIH3T3 cells.(omitted)

Expression of phase II detoxifying genes is regulated by Nrf2-mediated antioxidant response element (ARE) activation. We previously showed that phosphatidylinositol 3-kinase (PI3-kinase) plays an essential role in ARE-mediated rGSTA2 induction by oxidative stress.(omitted)

To assess the role of 8-oxoguanine glycosylase (OGG1) in the cell defense against radiation injury, the radiation-induced cytotoxicities were compared between the mutant type KG-1 featuring a loss of OGG1 activity due to a homozygous mutation of Arg 229 G1n, and the wild type U937.(omitted)

Abstract To study the status of oxidative DNA damage in Helicobacter pylori infection in more details, gene-specific oxidative DNA damage was investigated by examining oxidative DNA damage to individual genes. This was done by determining the loss of PCR product of a targeted gene before and after gastric mucosal DNA was treated with 8-hydroxyguanine glycosylase, which cleaves DNA at the 8-hydroxyguanine residues.(omitted)

Glycyrrhizin, a triterpenoid saponin fraction of licorice, is reported to have anti-viral and anti-tumor activities and is metabolized to 18$\beta$-glycyrrhetinic acid (GA) in the intestine by intestinal bacteria. However, the mechanism underlying its effects is poorly understood.(omitted)

We have investigated the effects of genistein on induction of cyclooxygenase-2 (COX-2) that plays an important role in the pathophysiology of carcinogenesis as well as in cellular response to inflammatory stimuli. Treatment of MCF10A cells with 12-O-Tetradecanoylphorbol-13-acetate (TPA) or TNF-$\alpha$ resulted in increased COX-2 expression and PGE$_2$ production, which was inhibited by genistein.(omitted)

Cyclooxygenase(COX) metabolizes arachidonic acid to prostaglandins and thromboxanes. It has been reported that there is 'cross-talk' between COX-2 and nitric oxide synthase(NOS). Stimulation of eNOS of estrogen fed animal heart was not accompanied by the increase in COX-2 expression.(omitted)

It is well known that oxygen radicals induce neuronal cell damage by initiation of lipid peroxidation chain reaction. Recent work has been also demonstrated that enzymatically generated free radicals cause the release of glutamate and aspartate from cultured rat hippocampal slices.(omitted)

In order to understand the mechanism of action of TCDD, we have examine the effect of COX-inhibitors on Cyp1a1 activity. We observed the effect of COX-inhibitor on EROD activity in C57BL/6 mouse in vovo. And we also evaluated the effect of COX-inhibitors on mouse cyp1a1 promoter activity in Hepa cell.(omitted)

We have examine the effect of all trans retinoic acid and 9-cis-retinoic acid on human breast cancer cell proliferation using SRB assay and cell cycle analysis. 1)In MCF-7 cells, in the presence of phenol red, either all trans retinoic acid or 9-cis-retinoic acid treatment showed the inhibition of the cell proliferation over control cells and also inhibit the estrogen stimulated cell proliferation when it was given together with estrogen.(omitted)

Recently we have reported that various hydroxystilbenes show strong inhibition of human P450 1 activity. A series of synthetic trans-stilbene derivatives were prepared and their inhibitory potentials were evaluated with the bacterial membrane of recombinant human P450 1A1, 1A2 or 1B1 coexpressed with human P450/NADPH-450 reductase to find new candidates for cancer chemoprevention.(omitted)

Oxidative stress has been associated with a number of diseases in humans. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS) with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality.(omitted)

Oxidative stress induced by reactive oxygen and/or nitrogen species has been considered as a major cause of cellular injuries in a variety of neurodegenerative disorders including Alzheimer's disease (AD). Inflammatory as well as oxidative tissue damage has been implicated in pathophysiology of AD, and non-steroidal anti-inflammatory drugs have been reported to have beneficial effects in the treatment or prevention of AD.(omitted)

Cyclooxygenases (COXs) are key enzymes in the conversion of arachidonic acid into prostanoids, which are involved in cell proliferation and inflammation. Two distinct COXS have been identified: COX-l which is constitutively expressed and COX-2 which is induced by different products such as tumor promoters or growth factors.(omitted)

Zearalenone (ZEA), a nonsteroidal estrogenic mycotoxin, is known to cause toxicity of testis in male rats. To investigate whether apoptosis is involved in ZEA-induced testicular toxicity and to identify the stage and target germ cell type, 10-weeks-old Sprague-Dawley male rats were treated with a single intraperitoneal (i.p.) dose of ZEA (5mg/kg) and euthanized at 3, 6, 12, 24, and 48 h subsequently.(omitted)

A mouse ear swelling test (MEST) has been developed as an alternative to guinea pig models for contact sensitization potential. However, the MEST relies on a quantitative measurement of ear swelling as an endpoint by micrometer. In this study, we aimed to investigate the cell proliferation in ear and lymph node using Bromodeoxyuridine (BrdU) immunohistochemistry as a possible reliable marker for MEST.(omitted)

Di-n-butyl phthalate(DBP) is one of the most commonly used phthalic acid esters(PAEs). It is extensively used as a plasticizer in elastomers and explosives, as a solvent for printing inks and resins and as a textile lubricating agent. It is also present in the formulations of various cosmetic products.(omitted)

In the present study, the potent lipopolysaccharide (LPS)-mimetic stimulation of B cells and macrophages by hot water extract from Salicornia herbacea (S. europeae L.) is described. The extract activated spleen cells to proliferate in a dose-related manner as measured by [$^3$ H)-thymidine incorporation response.(omitted)

2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a heterocyclic amine, significantly inhibits nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages. The decrease in NO production was found to correlate well with a decrease in iNOS mRNA expression as demonstrated by Northern blot analysis.(omitted)

It has been reported that the incidence of liver cancer in human is markedly sex-differentiated, with a much higher frequency in men than in women. In experimental animals, male have higher incidence of liver tumor than female in carcinogen-induced tumors as well as spontaneous tumors.(omitted)

Cyclooxygenase (COX), an important enzyme involved in mediating the inflammation, catalyzes the rate-limiting step in the formation of prostaglandins from arachidonic acid. There are two isoforms of COX, designated as COX-1 and COX-2. While COX-1 is constitutively expressed in most tissues, COX-2 can be induced transiently by proinflammatory cytokines, endotoxins, growth factors, oncogenes, UV and mitogens.(omitted)

A wide range of chemicals derived from plant and human-made xenobiotics are reported to have hormonal activity. The present studies were performed to examine the estrogenic effect of Kwao Keur, Pueraria mirifica (PM), that has been used a rejuvenating folk medicine from Thailand, using recombinant yeast, MCF-7 cell proliferation and HepG2 cell transient transfection assay.(omitted)

Several epidemiological studies suggested that arsenic exposure was strongly correlated with the development of cardiovascular disease such as hypertension. In order to examine whether arsenic affects vasomotor tone in blood vessels, we investigated the effect of arsenic on agonist-induced vasorelaxation using the isolated rat aortic rings in in vitro organ bath system.(omitted)

It has been reported that antinatriuresis is induced by acute cadmium intoxication. However, the mechanisms related to the increase in renal sodium reabsorption by cadmium exposure is not clear yet although it has been suggested that the elevated aldosterone might involve in this process.(omitted)

Mutations in the presenilin genes (PS-1 and PS-2) are linked to early onset familial Alzheimer's disease(AD), but its underlying cellular mechanisms have not been clear. 15-Deoxy-Δ12, 14-prostaglandin J2 (15-deoxy-PGJ2) is know as a naturally occurring ligand of the peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$).(omitted)

Alzheimer's disease (AD) is characterized by $\beta$-amyloid deposition and associated with loss of neuron cells in brain regions involved in learning and memory process. Many cases of early onset autosomal dominant inherited forms of AD are caused by mutation in the genes encoding presenilin-2 (PS-2).(omitted)

15-Deoxy-$\Delta$12, 14-prostaglandin J2 (15-deoxy-PGJ2), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-$\gamma$(PPAR-$\gamma$). It was known to have promoting ability of nerve growth factor(NGF)-induced neurite extension. However, it is not clear yet as to what signaling pathway is involved in its promoting ability of neurite extension.(omitted)

Many cases of early onset autosomal dominant inherited forms of Alzheimer's disease (AD) are caused by mutation in the genes encoding presenilin-2 (PS-2) on chromosome 1. It is characterized by amyloid deposition and associated with loss of neuron. However, molecular mechanisms underlying the role of PS-2 mutation in the pathogenic AD are not known.(omitted)

The age- and gender-related differences in acute toxicity and opening of blood-brain barrier induced by an organophosphate soman were investigated in rats. To assess acute toxicity, young (7 weeks old) and old (12 weeks old) male and female rats were subcutaneously administered with various dose levels of soman.(omitted)

Effects of betaine intake on hepatic fibrogenesis were examined in adult male SD rats treated with nitrosodimethylamine (DMN; 10 ${\mu}\ell$/kg/day, ip) 3 days a week for 4 weeks. From two weeks prior to initiation of DMN treatment until sacrifice rats were provided with drinking water containing 1 % betaine.(omitted)

Inhibitors of type IV phosphodiesterase (PDE IV) are currently being developed as new therapeutic agents for asthma, chronic obstructive pulmonary disease(COPD) and arthritis. Unfortunately, the anti-inflammatory effect of PDE IV inhibitors has been considered to be associated to some extent with vomiting as adverse effect. The first generation PDE IV inhibitor, rolipram, was known to induce emesis at clinical trials. (omitted)

The anti-diarrhea and spasmolytic activities of Soonkijangquebo (SKJQB), a Korean herbal anti-diarrhea formulation, were subjected to pharmacological evaluation. SKJQB, at a dose of 50\ulcorner200 mg/kg, inhibited castor oil-induced diarrhea in mice. The median effective dose (ED50) of the anti-diarrhea effect was 93 mg/kg.(omitted)

The spasmogenic activities and acute toxicity study of Yumijangquebo (YMJQB), a Korean herbal laxative formulation, were subjected to pharmacological evaluation. When tested in the contractile extent of guinea pig ileum, YMJQB displayed a spasmogenic effects in a concentration up to 0.05mg/ml and then decreased contractility of ileum; exhibiting the similar pattern with acetylcholine, a physiological regulator for peristaltic movement of the gut.(omitted)

Paclitaxel isolated from the pacific yew tree, Taxus brevifolia, is microtuble-stabilizing agent that has a promising anticancer activity against a wide variety of tumors such as ovarian, breast and lung cancers. Because of its poor water solubility, paclitaxel is currently formulated in a mixture of polyoxyethyleneglycerol triricinoleate 35 (Cremophor EL) and dehydrated ethanol USP (1:1 v/v).(omitted)

It has been reported that vitamin K analogues have various pharmacological effects such as antiviral, antifungal, anticancer, and antiplatelet activities. It has also been reported that some synthetic naphthoquinone compounds showed antiplatelet activities.(omitted)

Several 1,4-naphthoquinone derivatives have been reported to possess many pharmacological effects such as anti-viral, anti-fungal, anti-cancer and anti-platelet activities. However, little has been known about functional role in vascular smooth muscle cells (VSMCs).(omitted)

This study was designed to evaluate a repeated intravenous toxicity of a novel cephalosporin antibiotic, IDC7181, in Beagle dogs. Four groups, each consisting of 3 male and 3 female dogs (one year old, body weight 8 - 10 kg), were intravenously administered with IDC7181 at dose levels of 0 (vehicle control), 10, 50 or 250 mg/kg/day, respectively, for 28 days.(omitted)

Four-week repeated toxicity of SJ-8029, a novel anticancer drug, was investigated in rats. Male (body weight 188 $\pm$ 9 g) and female (body weight 155 $\pm$ 6 g) Sprague-Dawley rats were intravenously administered with SJ-8029 at dose levels of 0.75, 1.5 or 3.0 mg/kg, respectively, everyday for 28 days.(omitted)

We showed that END induced teratogenesis in larvae of the self-fertilizing fish Rivulus marmoratus. We discuss this and the issue of carcinogenesis caused by END.

Abstract The protective effects of physostigmine against the toxicity of parathion (diethyl-4-nitrophenyl phosphorothionate) were examined in male Sprague-Dawley rats. Physostigmine (100 or 1,000 ㎎/㎏, ip) injected 30 min before decreased the inhibition of acetylcholinesterase (AChE) activities in brain, lung and blood induced by parathion (2 ㎎/㎏, ip).(omitted)

In order to determine the effect of the DNA repair inhibitors, cytosine arabinoside(Ara C)and 3-aminobenzamide(3AB) on the frequenceis of chromosomal aberrations and micronuclei induced by radiation. After in vitro exposure of human lymphocytes to x-ray(1-3Gy) DNA repair inhibitors, Ara C and 3AB were treated and the frequencies of micronuclei, translocation and dicentric chromosomes were analysed using FISH technique with DNA probe for chromosome 4.(omitted)

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the best characterized environmental pollutants and is capable of causing a wide variety of toxicities including teratogenesis. TCDD has been known to increase as well as to decrease proliferation rates depending on the experimental conditions.(omitted)

Histopathological changes and cadmium accumulations in the gills were investigated in crucian carp(Carassius auratus) exposed to 0, 0.01, 0.1, 0.5mg/$\ell$ cadmium(Cd) concentrations for 25 days. After 25 days of exposure, cadmium accumulations increased in each of the different exposure concentrations.(omitted)

Methallothioneins(MTs) are low-molecular-mass cysteine-rich metal-binding proteins with high affinity for heavy metal ions, found in a large variety of organisms. Although the biological functions of MTS have not been fully elucidated, they are thought to play an important role in detoxification of toxic elements such as cadmium and mercury.(omitted)

In association with the international validation project to establish a test protocol for the "Enhanced OECD Test Guideline 407", we performed a 28-day repeated-dose toxicity study of vinclozolin (VCZ), an androgen antagonist, and ketoconazole (KCZ), a biosynthesis inhibitor of testosterone (T), and assessed the sensitivity of new parameters for detecting endocrine-related effects of endocrine-disrupting chemicals.(omitted)

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.(omitted)

Polychlorinated biphenyls (PCBs) are persistent environmental contaminants that elicit a broad spectrum of toxic effects in mammals and other vertebrate species. Because of their lipophilicity, chemical stability and resistance to biodegradation, PCBs tend to accumulate in the human body via food chain and environmental matrices including human adipose tissues, blood and milk.(omitted)

PCBs are wide spread persistent environmental pollutants that exert a broad spectrum of toxic effects. PCBs includes 209 possible congeners differing in extent and position of chlorination of their aromatic rings. In order to understand the toxic mechanism of PCBs, we have tested the effect of PCB on the EROD activity in vivo.(omitted)

Effects of antioxidant vitamins were investigated in di(2-ethylhexyl) phthalate (DEHP)-induced endocrine disruption toxicity. After rats were treated with DEHP, and vitamin C and vitamin E were supplemented for 30 days.(omitted)

Recently, there is an increasing nationwide concern in Korea that exposure to electric and magnetic fields (MF) in the home environment may not be safe in humans. We previously demonstrated that exposure of MF during the entire period of pregnancy did not induce any adverse effects on both pregnant dams and embryo-fetal development in rats.(omitted)

In order to investigate whether genetic polymorphisms in the mEH exon3 (Tyr139His), exon4 (His113Arg) interact with the formation of MN in benzene exposed workers, the PCR-RFLP based genotyping of 76 exposed and 115 controls were performed and cytokinesis-block micronucleus (CBMN) analysis of 56 exposed and 53 controls was employed.(omitted)

Nowadays a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms are developed and manufactured with safety evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively.(omitted)

Polycyclic aromatic hydrocarbons(PAHs) vary in their carcinogenic potencies. The more potent PAHs carcinogens are 3-methylcholantheren and 7, 12- dimethyl benzo(a)anthracene, while dibenzo(a, c)anthracene has very little carcinogenic activity. Risk assessment of chemical mixture containing various congeners which toxic potency are each different, are conducted using toxic equivalency factors(TEFs).(omitted)

Biologically Based Dose-Response (BBDR) models were developed using biomarkers for cancer risk assessment. To establish the relationship among biomarkers, exposure dose and tumor response, biomarkers in the lung, liver, stomach or blood were measured after a single or continuous administration of selected carcinogen (; BaP) in mice or rats.(omitted)

In recent years, the safety of sunscreens has been challenged based on the reports of its adverse effect on users; dermatitis, allergic contact dermatitis, photoallergic contact dermatitis. To investigate a correlation between sun protection factor (SPF) and the safety of sunscreens, we measured in vitro SPF index using homosalate as a standard and examined the toxicity tests on cosmetics; primary and cumulative skin irritation tests, ocular irritation test, and skin sensitization test.(omitted)