• Environmental Analysis Health and Toxicology
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• v.11 no.3_4
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• pp.1-10
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• 1996

The purpose of this study was to characterise the subacute toxic potency of i.v. administered KHPC-005 and 006. Few test compounds-related toxic effects were observed in body weight gain, clinical signs, urinalysis, hematological parameters and serum biochemical values. Gross necropsy and histopathology revealed no evidance specific toxicity. Our data indicated that no-observed effect level of KI-IPC-005 and 006 were estimated to be 10mg/kg and 4mg/kg in male rats, and 10mg/kg and 1.33mg/kg in female rats, respectively.

• BMB Reports
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• v.36 no.3
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• pp.294-298
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• 2003

The pathological effect of the Bacillus thuringiensis Cry $\delta$-endotoxins on susceptible insect larvae had extensive damage on the midgut epithelial cells. In this study, an ex vivo assay was devised for assessing the insecticidal potency of the cloned Cry4B mosquito-larvicidal protein that is expressed in Escherichia coli. Determination of toxicity was carried out by using a cell viability assay on the midguts that were dissected from 5-day old Aedes aegypti mosquito larvae. After incubation with the toxin proteins, the number of viable epithelial cells was determined photometrically by monitoring the quantity of the bioreduced formazan product at 490 nm. The results showed that the 65-kDa trypsin-activated Cry4B toxin exhibited toxic potency ca. 3.5 times higher than the 130-kDa Cry4B protoxin. However, the trypsin-treated products of the non-bioactive Cry4B mutant (R158A) and the lepidopteran-specific Cry1Aa toxin displayed relatively no ex vivo activity on the mosquito-larval midguts. The ex vivo cytotoxicity studies presented here confirms data that was obtained in bioassays.

• Korean Journal Plant Pathology
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• v.2 no.2
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• pp.89-95
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• 1986

The five short-chain fatty acids such as isobutyric(C-4), butyric(C-4), isovaleric(C-5), valeric(C-5) and caproic (C-6) acids obtained from the extract of common purslane showed wide antifungal spectra against spore germination and mycelial growth of the twenty five phytopathogenic fungi tested in vitro, although there were differences in antifungal potency among them. The antifungal potency of each fatty acid varied significantly against different fungi in spore germination and mycelial growth. The seventeen fungi used for spore germination test and the sixteen fungi used for mycelial growth test can be divided into three groups depending upon differences in minimal inhibitory concentration of each fatty acid for them, respectively. Caproic acid was significantly more toxic to germination than to mycelial growth of the test fungi, while the other four fatty acids did not show such a significant differences in toxicity with a few of exceptions as shown in valerie acid. The longer the chain-length of fatty acid was, the higher the antifungal potency was shown. The normal fatty acids such as butyric and valerie acid were more toxic than their isomers to spore germination and mycelial growth of the test fungi. Each fatty acid was more toxic to spore germination of obligate parasites and some of facultative parasites, and mycelial growth of facultative parasites than to spore germination and mycelial growth of saprophytes, respectively.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.136-136
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• 2002

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)

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.178-184
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• 1997

The cone calorimeter as defined by ISO 5660, ASTM 1354, and NFPA 264A is used to assess the reaction to fire of almost any material that must be evaluated in the fire science field. Typical combustion gas analyses include oxygen, CO and CO2. Oxygen consumption is used to determine rate of heat release. Analysis of combustion gases other than oxygen, CO and CO2 has been attempted using filters to remove the solid smoke particles before analysis. This method has generated unreliable results due to the adsorption of many gas components on the active carbon . particles deposited on the filters. A technique using fourier Transform Infrared (FTIB) analysis without filtration will be disclosed and a discussion will be presented of the analytical results of toxic gases produced from various flame retarded polymeric materials. Use of such data in lethal toxic potency determinations is also reviewed.

• Toxicological Research
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• v.20 no.4
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• pp.375-380
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• 2004

The toxicity of CKD-602 was investigated at doses of 0, 3, 9, and 27 mg/kg in rats, by administering the same total dose over 24-hr continuous infusion or bolus injection. CKD-602 treatment caused gastrointestinal symptoms such as diarrhea, soft stool, and soiled perineal region. It also decreased body weight at doses of 9 and 27 mg/kg in a dose-dependant manner. At 3 mg/ kg, clinical signs and body weight decrease were more severe in the infusion group than in the bolus group. In the bolus group, mortalities were 0/8, 0/8, 1/8, and 3/8 at 0, 3, 9, and 27 mg/kg, respectively, whereas those were 0/8, 1/8, 8/8, and 8/8 in the infusion group. $LD_{50}$ values were 36.25 mg/kg for bolus and 3.50 mg/kg for infusion, respectively. This finding indicates that the toxic potency of CKD-602 by continuous infusion is about 10 times higher than by bolus injection. Our findings suggest that the toxic effects of CKD-602 are dependant upon the duration of intravenous administration.

• The Korea Journal of Herbology
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• v.36 no.4
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• pp.9-22
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• 2021

Objective : The purpose of this dissertation is to make a list of the phaeophyta growing naturally in the Korean coastal waters, and to carry out a survey on the current distribution status to investigate the phaeophyta which can be used as medicinal herbs. Methods : References and research papers about herbology published at home and abroad were examined. Results : The results of this study were as follows : A total of 63 genera and 145 species of phaeophyta was found in the Korean coastal waters among which 11 genera and 15 species(approximately 11%) were medicinal plants. Out of the 145 species of phaeophyta 27 species belonged to Sargassum, and out of the 15 species of medicinal plants 4 species belonged to Sargassum. Among the medicinal parts 11 species belonged to algae. Sixteen species had cold property, and 16 species had salty flavors. Thirteen species had the efficacy of liver meridian, and 15 species had the potency of YEONKYUN, which helps to remove hard clots generated in human body. No toxic drugs were detected. Conclusion : There were totaled to 63 genera and 145 species in Phaeophyta in Korea and among them medicinal plants are 11 genera, 15 species, some 11% in total. Thirteen species had the efficacy of liver meridian, and 15 species had the potency of YEONKYUN, which helps to remove hard clots generated in human body. No toxic drugs were detected.

• Environmental Analysis Health and Toxicology
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• v.19 no.2
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• pp.177-182
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• 2004

Alcohol consumption and exposure to endocrine disruptors and industrial solvents have been implicated in impaired spermatogenesis, increase in the incidence of malformed sperm and decrease in the percentage of moving sperm. The aim of this study was to determine and compare the direct effects of some organic solvents(bisphenol A; BPA, dibutyl phthalate; DBP, formaldehyde; HCHO, dimethylsulphoxide; DMSO, ethanol) on mucus penetration distance, motility and survival rate of human sperm in vitro. Semen samples from 3 health subjects were prepared using swim-up method and 0.0005-0.5% organic solvents were added to the test medium. BPA, DBP, HCHO and DMSO produced significant decreases in the motility and survival rate with a different potency. The most potent inhibition of mucus penetration distance, motility and survival rate was observed after exposure to HCHO. A concentration of 0.0005% HCHO significantly inhibited sperm motility. When ethanol m.: added directly to sperm, at concentrations equivalent to that in serum after heavy drinking, these damaging effects were lowest compared with other solvents. Present study shows that each compound has different toxic potency to human sperm and we need special caution for the use of HCHO.

• Biomedical Science Letters
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• v.24 no.1
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• pp.50-54
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• 2018

N-nitroso-N-methylurea (NMU) and N-nitroso-N-ethylurea (NEU), direct alkylating chemical mutagens and carcinogens, are shown to be the upregulators of cellular $NF-{\kappa}B$, regulating various genes that mediate tumorigenesis and carcinogenesis. Nitric oxide (NO), a toxic reactive radical gas, has been known to induce programmed cell death or apoptosis in various cells. Therefore, the assessment of NO production was examined to elucidate the possible contribution of NO release to the chemical carcinogenic potency of NMU and NEU in human skin cells. NMU and NEU did not alter the NO production, but they caused a significant downregulation of the NO generation on lipopolysaccharide (LPS)-induced NO production at concentrations ranging from $2{\sim}5{\mu}M$. The degree of downregulation of NO by NMU and NEU decreased up to 15% and 20%, respectively, compared to the control. These results demonstrate that the LPS-inducible keratinocytes NO synthase is involved in modulating carcinogenic potency by NMU and NEU, and the regulation of the cellular $NF-{\kappa}B$ activity by NMU and NEU is negatively correlated with the level of LPS-induced NO production in human skin cells. The findings of this study suggest the hypothesis that NMU and NEU-induced carcinogenesis may be associated with the downregulation of NO production, and the inducible NO may play an important role in NMU and NEU-induced carcinogenicity in human epidermal keratinocytes.

• Journal of Pharmacopuncture
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• v.17 no.3
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• pp.7-15
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• 2014

Objectives: The present study investigated the toxic properties of petroleum ether extract of Wattakaka (W.) volubilis in Wistar female rats. Methods: An in vitro brine shrimp lethality bioassay was studied in A. Salina nauplii, and the lethality concentrations were assessed for petroleum ether extract of W. volubilis. A water soluble portion of the test extract was used in different concentrations from $100-1000{\mu}g/mL$ of 1 mg/mL stock solution. A 24-hours incubation with a 1-mL aliquot in 50 mL of aerated sea water was considered to calculate the percentage rate of dead nauplii with test extract administration against a potassium-dichromate positive control. The acute and the sub-acute toxicities of petroleum ether extract of W. volubilis were evaluated orally by using gavage in female Wistar rats. Food and water intake, body weight, general behavioral changes and mortality of animals were noted. Toxicity or death was evaluated following the administration of petroleum ether extract for 28 consecutive days in the female rats. Serum biochemical parameters, such as alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, total cholesterol, triglyceride, total protein, glucose, urea, creatinine, sodium, potassium and ${\alpha}$-amylase levels, were measured in the toxicity evaluations. Pathological changes in isolated organs, such as the liver, kidneys, and pancreas, were also examined using hematoxylin and eosin dye fixation after the end of the test extract's administration. Results: The results of the brine-shrimp assay indicate that the evaluated concentrations of petroleum ether extract of W. volubilis were found to be non-toxic. In the acute and the sub-acute toxicity evaluations, no significant differences were observed between the control animals and the animals treated with extract of W. volubilis. No abnormal histological changes were observed in any of the animal groups treated with petroleum ether extract of W. volubilis. Conclusion: These results suggest that petroleum ether extract of W. volubilis has a non-toxic effect in Wistar female rats.