• International Journal of Industrial Entomology and Biomaterials
• /
• v.9 no.1
• /
• pp.73-78
• /
• 2004

The impact of low concentration fluoride on toxification was studied by treating $3^rd$ instar silkworm larvae of Qiufeng${\times}$Baiyu (Fluoride resistant strain) and Jinshong${\times}$Haoyue (Fluoride sensitive strain). The $5^th$ instar silkworm larvae of Zhenong-l, Shu-12, Qiufeng ${\times}$ Baiyu, Chunhua ${\times}$ Qhiushi, Jinshong and Haoyue were fed mulberry leaves treated with sodium fluoride at different concentrations to determine its effect on fecundity. Harmful effects of low concentration fluoride at early instars on growth, development and economic characters of Bombyx mori are related to its resistance. Harmful effect on resistant strain Qiufeng${\times}$Baiyu manifested on prolongation of instar duration of 15 and 6% in 70 ppm, where as the sensitive breed Jinshong${\times}$Haoyue manifested with 100% mortality in 50 ppm. The impact of low concentration fluoride on fecundity resulted in considerable increase in formed eggs (9%) and laid eggs (9%) in Zhenong-l and Shu-12 among treated population over control. The present observations emphasis that fluoride apart from exhibiting harmful effects on silkworm growth and development, however, its low concentration do playa vital role in inducing some positive effect on fecundity and cocoon traits.

• Toxicological Research
• /
• v.22 no.4
• /
• pp.333-338
• /
• 2006

This study was to investigate the preventive effects in anti-oxidation of Ulva lactuca extract fractions (ULEF) against $CCl_4$ toxification in liver total homogenate and mitochondrial fraction of ULEF-pretreated and carbon tetrachloride $(CCl_4)-posttreated$ rats. ULEF was intraperitoneally administered into rats at dose of 1 ml/kg for14 days. On the day 15, 3.3 ml/kg of $CCl_4$ dissolved in olive oil (1:1) was injected 12 hr before anesthetization. Activities of superoxide dismutase(SOD) in mitochondrial fraction were measured and catalase (CAT), glutathione peroxidase (GPx), malondialdehyde (MDA) in liver total homogenate. SOD, CAI and GPx were higher in the ULEF-pretreated and $CCl_4-posttreated$ group than those in the $CCl_4-posttreated$ group, and the pretreatment of ULEF decreased MDA. These results showed that the pretreatment of ULEF had the preventive role in the activities of anti-oxidative enzymes, SOD, CAT and GPx

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.6
• /
• pp.856-861
• /
• 1996

The occurrence of TTX in ciliated protozoa was investigated in order to clarify tetrodotoxin (TTX) accumulation mechanisms in marine organisms. Tissue culture bioassay, HPLC, and GC-MS analyses confirmed the occurrence of TTX in Euplotes mutabilis and also in bacteria isolated from the culture medium. Fluorescently labeled bacteria (FLB) were prepared with those bacteria, and predation by E. mutabilis was observed. The results indicated that TTX in bacteria can be transferred to higher trophic levels through the food chain.

• Biomolecules & Therapeutics
• /
• v.12 no.3
• /
• pp.185-188
• /
• 2004

The purpose of this study is to evaluate the effect of cigarette smoke condensate (CSC) on toxification/detoxification metabolic pathway in primary cultured rat hepatocytes. We measured the activities of cytochrome P450 monooxygenases (CYP450s) and UDP-glucuronyltransferase, sulfotransferase and glutathione-S-transferase in CSC-treated rat hepatocytes. CSC significantly increased the activities of hepatic CYP4501A1 and CYP4501A2 to 7.5 fold and 1.6 fold respectively, compared with control level. However, CSC did not affect the activities of conjugation enzymes. We a1so examined if treatment of CSC could change thc cytotoxicity of acetaminophen (AA) through modulation of metabolizing enzymes. In rat hepatocytes, pretreatment with CSC potentiated the cytotoxicity of AA. This result indicates that potentiation of AA toxicity by CSC pretreatment may be related to induction of CYP4501A1 and CYP4501A2.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2006.09a
• /
• pp.62.1-62.1
• /
• 2006

• Korean Journal of Environment and Ecology
• /
• v.13 no.2
• /
• pp.176-183
• /
• 1999

울산지역의 사문암과 유문암 토양 및 쑥과 참억새의 중금속 함량을 비교하기 위하여 중금속 농도를 분석한 결과 사문암 풍화토의 Ni, Cr 및 Co 함량은 매우 높았다. Ni은 1,483~1.524ppm, Cr은 372~435ppm, Co는 68~79ppm였으며, 유문암 풍화토의 Zn 함량은 222ppm으로 사문암 풍화토보다 높았다. 사문암 풍화토에서 생육하는 쑥의 중금속 함량은 Ni이 108~195ppm. Cr이 135~180ppm, Co가 10.2~22.5ppm으로 유문암 풍화토의 쑥보다 높았고, Zn은 유문암 토양 쑥에서 높았다. 참억새의 경우는 Ni, Cr, Co, As, Se, Mo 및 Fe 가 사문암 토양에서 높았고, Zn 흡수는 유문암 토양에서 많았다. 쑥의 중금속 함량은 대체적으로 지상부가 지하부보다 높았으나, 참억새의 경우는 지하부가 높은 경향을 나타내었다. 토양과 식물체(쑥과 참억새)의 중금속 함량을 비교해 보면 Ni, Cr, Co, As, Sc, Mo 및 Fe의 함량은 토양의 식물체보다 높았으나, 유문암 토양에 있는 쑥의 Zn 흡수는 토양보다 다소 높았다. 식물체의 Fe:Ni 비율은 유문암 토양보다는 사문암 토양이, 참억새보다는 쑥이 낮게 나타났다.

• Biomolecules & Therapeutics
• /
• v.1 no.1
• /
• pp.50-57
• /
• 1993

This study characterized the effect of liver injury produced by hepatotoxicants on the biliary and urinary excretion of acetaminophen(AA) metabolites. Liver damage was produced in male S.-D. rats, 24 hr after dosing with carbon tetrachloride(4CCl_4,$ 0.75 mι/kg, ip) or thioacetamide(TA, 200 mg/kg, ip), or 16 hr after administration of cadmium chloride(4CdCl_2,$ 3.9 mg/kg, iv). Liver damage without renal injury was confirmed by measuring serum enzymes, creatinine and BUN levels as well as by histopathological examination. AA and its metabolites were measured for 3 hr by HPLC in rats injected iv with 1 mmo1/kg of AA. The excreted amounts of AA-glucuronide into bile were reduced to 60~70% of control rats by hepatotoxicants, but did not change urinary excretion of AA-glucuronide and AA-sulfate. Treatments with $CCl_4,\; CdCl_2$ and TA decreased the total (biliary plus urinary) excretion of thioethers of AA(30~50% of control), suggesting that these toxicants decrease cytochrome P-450-mediated toxification of AA. However, treatments of $CdCl_2$and TA markedly enhanced the excretion of AA-mercapturate into urine. Thus, 4CdCl_2$ and TA not only influence the formation of AA-glutathione, but may also alter the excretory routes (i.e. bile and urine) for the elimination of AA-metabolite.

• Safety and Health at Work
• /
• v.2 no.2
• /
• pp.97-104
• /
• 2011

N,N-Dimethylformamide (DMF) is globally used as an organic solvent in the production of synthetic leather and resins because of its low volatility, making it an attractive industrial material. Despite its excellent property as a chemical solvent, utilization of DMF is somewhat controversial nowadays due to its hazardous effects on exposed workers in work places. Many toxification cases are being reported globally and the number of cases of liver damage is still increasing in developing countries. On account of this, a series of epidemiologic surveys are being conducted to understand the degrees of liver damage caused by DMF exposure. Furthermore, many investigations have been performed to clarify the mechanism of DMF-induced liver toxicity using both human and experimental animal models. This review summarizes the current occupational cases reported on liver damage from workers exposed to DMF in industrial work places and the research results that account for DMF-induced liver failure and possible carcinogenesis. The findings reviewed here show the synergistic toxicity of DMF exposure with other toxicants, which might occur through complicated but distinct mechanisms, which may extend our knowledge for establishing risk assessments of DMF exposure in industrial work places.

• The Korean Journal of Ecology
• /
• v.20 no.5
• /
• pp.385-391
• /
• 1997

To investigate the degrees of toxification in the serpentine areas, serpentinites and adjacent metamorphic rocks and soils from the serpentinite, metamorphic area and transitional area(mixed soil) between serpentinite and metamorphic rocks are collected from the Hongseong-Gun, Chungnam. A plant, Geochemically, the serpentinites are high in the nickel, chromium and cobalt content whereas the metamorphic rocks show high zinc, scandium, molybdenum and iron contents. The serpentine soils are high in the nickel, chromium and cobalt contents whereas the non-serpentine soils show high zinc and iron contents. Heavy metal contents in the G. oldhamiana are high in the serpentine soil relative to the mixed soil. Ratio of the iron to nickel contents for the G. oldhamiana are low in the serpentine soil(49) relative to the mixed soil(216). Of the G. oldhamiana, most of the heavy metal contents except zinc and molybdenum are high in the root relative to the aboveground vegetation. Comparing with rocks, the G. oldhamiana is low in the all of heavy metal contents relative to the serpentinite. Uptake of zinc by the G. oldhamiana is high in the serpentinites and metamorphic rocks whereas uptake of scandium and iron by the G. oldhamiana is very high in the serpentinite area.

• BMB Reports
• /
• v.39 no.5
• /
• pp.595-606
• /
• 2006

Metallothioneins are a group of low molecular mass and cysteine-rich metal-binding proteins, ubiquitously found in most living organisms. They play an important role in maintaining intracellular metal homeostasis, eliminating metal toxification and protecting against intracellular oxidative damages. Analysis of complete rice genome sequences revealed eleven genes encoding putative metallothionein (OsMT), indicating that OsMTs constitute a small gene family in rice. Expression profiling revealed that each member of the OsMT gene family differs not only in sequence but also in their tissue expression patterns, suggesting that these isoforms may have different functions they perform in specific tissues. On the basis of OsMT structural and phylogenetic analysis, the OsMT family was classified as two classes and class I was subdivided into four types. Additionally, in this paper we also present a complete overview of this family, describing the gene structure, genome localization, upstream regulatory element, and exon/intron organization of each member in order to provide valuable insight into this OsMT gene family.