• International Journal of Industrial Entomology and Biomaterials
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• 제13권2호
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• pp.119-122
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• 2006

As the Selenium is known to be growth promoter in sheep and cattle, the efficacy of selenium has been tested in silkworm Bombyx mori L. The V instar larvae were fed with lethal and sub-lethal doses of selenium treated leaves. The larvae fed with lethal dose showed a significant decrease in growth and Cocoon commercial characters. The treatment with sub lethal dose exhibited a significant increase in the growth of the silkworm. Correspondingly, the cocoon commercial characters on exposure to the lethal dose showed significant decrease and sub lethal dose showed a significant increase. In the light of similar findings reported earlier in other cocoon crops and vertebrates, it can be inferred that selenium at lower doses acts as a growth stimulator, resulting in the higher yield of cocoon crop.

• 생명과학회지
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• 제14권1호
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• pp.188-192
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• 2004

Toluene tolerance and therrnotolerance in Crampositive organic solvent resistant bacterium Micrococcus sp. BCNU 121 has been studied. Exposure to a sub- lethal temperature or a sub-lethal concentration of toluene conferred protection to subsequent challenges with a killing temperature or a lethal concentration of toluene, respectively. Pretreatment of Micrococcus sp. BCNU 121 with sub-lethal concentrations of toluene induced adaptative protection against heat shock. Moreover, temperature-adaptative cells also showed cross-resistance to lethal doses of toluene. These data suggested a cross-regulation between toluene tolerance and heat shock response.

• Toxicological Research
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• 제24권4호
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• pp.235-243
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• 2008

While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

• 한국군사과학기술학회지
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• 제24권3호
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• pp.348-355
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• 2021

Hantaan virus(HTNV) causes hemorrhagic fever with renal syndrome(HFRS) with a case fatality rate ranging from <1 to 15 % in human. Hantavax^Ⓡ is a vaccine against the Hantavirus, which has been conditionally approved by the Ministry of Food and Drug Safety(MFDS). However, only 50 % of volunteers had neutralizing antibodies 1 year following the boost. Effective antiviral treatments against HTNV infection are limited. Hantaviruses generally cause asymptomatic infection in adult mice. On the other hand, infection of suckling and newborn mice with hantaviruses causes lethal neurological diesease or persistant infection, which is different from the disease in humans. The development of vaccines and antiviral strategies for HTNV has been partly hampered by the lack of an efficient lethal mouse model to evaluate the efficacy of the candidate vaccines or antivirals. In this report, we established a lethal mouse model for HTNV, which may facilitate in vivo studies on the evaluation of candidate drugs against HTNV. The median lethal dose value of HTNV was calculated by probit analysis of deaths occurring within two weeks. Five groups of ten ICR mice were injected intracranially with serial 2-fold dilutions (from 50 to 3.125 PFU/head) of HTNV. Mice injected with HTNV began to die at 8 days post-infection. The lethal dose required to kill 50 % of the mice (LD₅₀) was calculated to be 2.365 PFU/head.

• Toxicological Research
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• 제20권4호
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• pp.321-324
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• 2004

Lethal dose 50% ($LD_{50}$) has been commonly used as a parameter for the estimation of acute toxicity not only in animal experiment, but also in human study. Several methods to estimate $LD_{50}$ had been introduced, but Spearman-Karber and Berens-Karber method have been widely used due to their relative convenience and accuracy. However, $LD_{50}$ values estimated from the two methods showed inconsistency and variation depending on the characteristics of mortality data. In this study, the two methods were comparatively investigated in terms of accuracy and stability for the estimation of $LD_{50}$.

• 한국어병학회지
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• 제36권2호
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• pp.349-360
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• 2023

Common carp (Cyprinus carpio) (Weight 23.05 ± 6.98 g, Length 12.65 ± 1.38 cm) were exposed to waterborne nitrite at 0, 50, 100, 200, 400 and 800 mg NO₂ ^-/L for 96 hours. The lethal concentration 50 (LC₅₀) of C. carpio exposed to waterborne nitrite was 398.6 mg NO₂ ^-/L. Hemoglobin, hematocrit and RBC count were significantly decreased by waterborne nitrite exposure. The MCV (mean mean corpuscular volume) (µl), MCH (mean corpuscular hemoglobin) (pg) and MCHC (mean corpuscular hemoglobin concentration) (%) were significantly increased. The inorganic component, plasma calcium, was significantly increased, and the organic components such as plasma cholesterol and total protein were significantly increased showing a similar tendency with calcium. In enzymatic components, the AST and ALT were also significantly increased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of C. carpio.

• 한국수산과학회지
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• 제53권3호
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• pp.451-455
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• 2020

This study evaluated acute toxicity of chlorine dioxide (ClO₂ ) to juveniles of black seabream Acanthopagrus schlegelii (19.4±2.3 g, 10.7±0.4 cm) and red seabream Pagrus major (74.9±8.2 g, 15.9±1.0 cm). Thirty juveniles for each species were exposed to target ClO₂ concentrations of 0, 0.05, 0.1, 0.125, 0.15, 0.2, 0.3, 0.4, and 0.5 mg/L in triplicate for eight days. Half lethal concentrations for 96 hours were found at 0.14 and 0.24 mg ClO₂/L for black seabream and red seabream, respectively. Red seabream larger than black seabream in body weight appears to be more resistance to chlorine dioxide. However, regardless of species or size, specific loading rates of chlorine dioxide to total fish weight (daily feeding amount of ClO₂/total fish weight) were similar, showing 1.3 and 1.1 g ClO₂/kg fish·day^-1 for black seabream and red seabream.

• 한국환경생태학회지
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• 제34권3호
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• pp.207-215
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• 2020

농약류 3종의 독성평가를 위해 FETAX(Frog Embryo Teratogenesis Assay-Xenopus) 기법에 따라 국내에 서식 중인 두꺼비(Bufo gargarizans)의 배아를 배양하면서 Benomyl(살균제), Carbofuran(살충제), Thiobencarb(제초제)의 영향을 probit 분석법으로 조사하였다. 그 결과, Benomyl, Carbofuran, Thiobencarb의 농도에 의존하여 유생의 체장 길이는 감소하고 치사율과 기형율은 증가하였다. Benomyl, Carbofuran, Thiobencarb의 teratogenic concentration(EC₅₀)은 각각 1.03, 8.74, 4.98mg/ℓ을 나타내어 Benomyl이 기형 유발에 가장 민감하게 반응하였으며, embryo lethal concentrations(LC₅₀)은 7.26, 560.72, 16.87mg/ℓ을 나타내어 Benomyl이 가장 낮은 농도에서 배아가 치사되는 것으로 나타났다. Teratogenic index (TI=LC₅₀/EC₅₀)는 Benomyl 7.05, Carbofuran 64.16, Thiobencarb 3.39를 나타내어 TI값이 모두 기형유발물질로 판단되는 기준인 1.5이상으로 시험에 사용된 농약류 3종은 최기형성 물질로 판단된다. Carbofuran이 가장 강력한 최기형성물질로 작용함을 알 수 있었으며, 농약류가 두꺼비 및 양서류의 배아 발달에 미치는 영향과 그 작용기작을 규명하기 위해서는 보다 구체적인 연구가 필요할 것으로 판단된다.

• ALGAE
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• 제27권1호
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• pp.63-70
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• 2012

Algae are sensitive to a wide range of pollutants, and are effective bioindicators in ecotoxicity assessments. Here, we evaluated the sub-lethal sensitivity of the marine dinoflagellate Cochlodinium polykrikoides upon exposure to copper (Cu), lead (Pb), bisphenol A (BPA), and Aroclor 1016 (polychlorinated biphenyl, PCB). Toxic effects were assessed by observations of the reduction in cell counts and chlorophyll a levels after exposure to each toxicant. C. polykrikoides displayed dose-dependent, sigmoidal responses when exposed to the tested chemicals. $EC_{50}$-72 h values for Cu, Pb, BPA, and PCB were 12.74, 46.70, 68.15, and $1.07mg\;L^{-1}$, respectively. PCB, which is an endocrine-disrupting chemical, was the most sensitive, proving its toxic effect on the dinoflagellate. This study provides baseline data on the toxic effects of commonly used heavy metals and endocrine-disrupting chemicals to a marine dinoflagellate.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2000년도 추계심포지움 및 학술발표회:바이오모니터링 기법을 이용한 환경위해성 평가
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• pp.12-19
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• 2000