• Toxicological Research
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• v.31 no.4
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• pp.331-337
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• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.30 no.3
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• pp.46-61
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• 2017

Objectives : Allergic contact dermatitis(ACD) is a type IV delayed hypersensitivity reaction that results from cumulative exposures and subsequent sensitization to an environmental chemical. Lonicerae Caulis(LC) can clear away heat and relieve toxin, disperse wind and heat, dredge the channel. The present study was designed to investigate the effects of LC on allergic contact dermatitis(ACD) induced by 2,4-dinitrochlorobenzene(DNCB) in mice. Methods : In this experiment, the effects of LC on changes in body weights, ear and dorsum skin thicknesses, ear weights, clinical aspects on the dorsum skin, histopathological changes, spleen/body ratio, cytokines were investigated. In addition, the effects on proliferations of splenocytes were also investigated in vitro and vivo study. Results : LC spread(SPR) group and LC spread and administered(SPR+ADM) group showed diminished ear thicknesses. In SPR+ADM group, ear weights were lowered significantly compared to contact dermatitis control(CTL) group. LC treatment diminished erythema, desquamation and keratosis which were induced by repeated painting of DNCB. In histopathological observation, spongiosis and edema were diminished in SPR and SPR+ADM group. In cytokines, SPR+ADM group were increased in IL-10, and SPR and SPR+ADM group were decreased in TNF-${\alpha}$ compared with control group. Conclusions : These data suggest that LC can decrease symptoms of ACD, then LC is useful to treat patient with ACD.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.459-463
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• 1999

The effects of the hindered and non-hindered water soluble long-chain disulfide bonds on the stability and cytotoxicity of the ricin A chain (RTA) immunotoxin were examined. The RTA immunotoxins were prepared with the Fab fragments of anti-common acute lymphoblastic leukemia antigen (CALLA) monoclonal antibody (Fab-RTA) using sulfosuccinimidyl-6-[(-methyl-(-2-pyridyldithio)toluamido]toluamido]hexanoate (S-LC-SMPT) and sulfosuccinimidyl-6-[3-(2-pyridyldithio-propionamido]hexanoate (S-LC-SPDP). The prepared Fab-RTA immunotoxins were evaluated for their conjugation yield, immunoreactivity, thermal and disulfide bond stability and cytotoxicity. The conjugation yield of the Fab-RTA immunotoxin from the water soluble long chain crosslinking agents, S-LC-SMPT and S-LC-SPDP, were comparable. Both Fab-RTA immunotoxins exhibited a similar immunoreactivity and thermal stability in aqueous solution. However, S-LC-SMPT -mediated Fab-RTA, sterically hindered, showed an enhanced disulfide bond stability in vitro over S-LC-SPDP mediated one. In the cytotoxicity against antigenic cell Daudi, the S-LC-SMPT -mediated RTA immunotoxin maintained a comparable cytotoxicity, compared with S-LC-SPDP mediated Fab-RTA immunotoxin.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.1019-1032
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• 2013

The accurate prediction of future mortality is an important issue due to recent rapid increases in life expectancy. An accurate estimation and prediction of mortality is important to future welfare policies. The optimal selection of a mortality model is important to estimate and predict mortality; however, the period of time series data used is also an important issue. It is essential to understand that the time series data for mortality is short in Korea and the data before 1982 is incomplete. This paper divides the time series of Korean mortality into two sets to compare the parameter estimates of the LC model and LC model with a cohort effect by the period of data used. A modeling and prediction of the mortality index and cohort effect index as well as the evaluation of future life expectancy is conducted. Finally, some suggestions are proposed for the future prediction of mortality.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.35-44
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• 1998

In this paper, input LC filter design of diode rectifiers considering filter V A rating reduction has been propoesd. It consisted of an input LC parallel resonent tank whose inductor and capacitor values are se$.$ lected so that the input filter presents an infinite impedance to harmonic input ac current component. The operation of proposed input filter has been analyzed in detail under steady state conditions. Performance evaluation and related design data have been provided on Per Unit basis for the proper implementation of diode rectification system. Finally, Detailed input and output current analysis has shown that the proposed input filter yield high quality input ac current waveforms, in particular, high input power factor values and more reliabilty which reducing the V A rating of passive components as compared to the standard type LC filter.filter.

• Biomolecules & Therapeutics
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• v.20 no.4
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• pp.393-398
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• 2012

Recently, we reported that defective autophagy may contribute to the inhibition of the growth in response to PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), a selective SFK inhibitor, in multidrug-resistant v-Ha-ras-transformed NIH 3T3 cells (Ras-NIH 3T3/Mdr). In this study, we demonstrated that PP2 induces LC3 conversion via a mechanism that is uncoupled from autophagy and increases apoptosis in Ras-NIH 3T3/Mdr cells. PP2 preferentially induced autophagy in Ras-NIH 3T3 cells rather than in Ras-NIH 3T3/Mdr cells as determined by LC3-I to LC3-II conversion and GFP-LC3 fluorescence microscopy. Beclin 1 knockdown experiments showed that, regardless of drug resistance, PP2 induces autophagy via a Beclin 1-dependent mechanism. PP2 induced a conformational change in Beclin 1, resulting in the enhancement of the pro-autophagic activity of Beclin 1, in Ras-NIH 3T3 cells. Further, PI3K inhibition induced by wortmannin caused a significant increase in apoptosis in Ras-NIH 3T3 cells, as demonstrated by flow cytometric analysis of Annexin V staining, implying that autophagy inhibition through PI3K increases apoptosis in response to PP2 in Ras-NIH 3T3 cells. However, despite the fact that wortmannin abrogates PP2-induced GFP-LC3 punctae formation, some LC3 conversion remains in Ras-NIH 3T3/Mdr cells, suggesting that LC3 conversion may occur in an autophagy-independent manner. Taken together, these results suggest that PP2 induces LC3 conversion independent of PI3K, concomitant with the uncoupling of LC3 conversion from autophagy, in multidrug-resistant cells.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.277-283
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• 2019

In this study, low molecular weight chitosan (LC) was added to dental cement liquid at 0, 0.5, 1.0, and 2.0 wt% by weight for surface properties and oral bacteria adhesive of dental cement. The evaluated by net setting time and surface properties of surface energy on the surface roughness. The degree of oral bacterial adhesion was assessed using two strains of oral bacteria, S. mutans and E.coli. The results showed that the setting time at the LC0.5 group increased no statistically difference was observed (p<0.05). The surface roughness statically significant LC2.0 group and oral bacteria adhesion experiment results in contrast to the control group LC0, LC-added experimental group showed a somewhat lower adherent surface statistically significant difference was observed (p<0.05). It seems that this LC proved that surface properties and oral bacteria adhesion effect was demonstrated. Therefore, it was suggest that the additional effects of LC and research on a wide range of substances.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.109-120
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• 1986

This study was conducted to define the effect of addition of lysolecithin (LC) and 20% v/v rabbit serum to sperm preincubation medium on the induction of acrosome reaction (AR) an fertilizing ability in vitro of LG-added sperm. Ejaculated rabbit sperm from New Zealand White buck was washed once by centrifugation, then preincubated for 2 or 4 hrs in a chemically defined medium (DM), DM plus 20% rabbit serum or BSA-free DM plus 20% rabbit serum at 37$^{\circ}C$ water bath or CO2 incubator. At the end of preincubation LC was added to the preincubated sperm, which was stained at 0.5 to 4 hr later and examined for AR and sperm motility. For in vitro fertilization, gametes were coincubated in DM up to 24 hrs and thereafter fertilized embryos were incubated in BSM -II up to 48 hrs. Addition of LC to 4-hr preincubated sperm was more effective for the AR and sperm motility than that to 2-hr preincubated sperm and optimal concentration of LC for AR was about 80${\mu}$g/ml. A significant increase in AR occured from 20 to 30 min. after addition of 80 to 100${\mu}$g/ml in 4-hr preincubated sperm. BSA-free DM plus 20% rabbit serum showed a higher AR and sperm motility than those of DM plus 20% rabbit serum in LC-added sperm after 4-hr preincubation. The incidence of AR after 4-hr preincubation and at 30 min after 60${\mu}$g/ml LC addition varied greatly among individual bucks. Sixty ${\mu}$g/ml LC-added sperm showed a slight high cleavage rate over control levels, but 100${\mu}$g/ml LC-added sperm showed lower cleavage rate rather than 60${\mu}$g/ml LC. It is concluded that optimal concentration of LC for high AR induction and sperm motility in 4-hr preincubated sperm was about 80${\mu}$g/ml, but 60${\mu}$g/ml level was more useful for in vitro fertilization.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.165-169
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• 1999

A study was performed on the susceptibility of Abate@ and Abate-S@ against 3rd instar larvae of 5 species of mosquitoes including Anopheles sinensis, Aedes dorsalis, Culex inatomii, Cx. pipiens pallens, Cx. tritaeniorhynchus and mosquito larvivorous fishes such as Chinese muddy loaches (Misgurnus muzolepis) and crucian carps (Carassius carassi~4s) in September, 1998. Cx. pipiens larvae showed that the LC5os of both Abatea and Abate-Sa were 0.006 ppm. The LC95 values of this mosquito species appeared 0.070 pprn of Abate@ and 0.035 pprn of Abate-S@ which were more susceptible than the dosage (1.0 ppm) recommended from WHO. An. sinensis larvae appeared 0.009 pprn of LC50 and 0.025 pprn of LCgs. The larvae of Cx. inatomii and Ae. dorsalis showed the most highly susceptible to Abate-S@ among the 5 mosquito species with LC50 values of 1.9 x pprn and 1.1 x pprn respectively, and the LC95 values were 5.2 x 10-hppm and 1.4 x ppm, respectively. On the other hand, Cx. tritaeniorhynchus appeared least affected by Abate-Sa. and was brought 0.048 pprn of LC50 and 0.808 pprn of LCg5. These two insecticides were much less toxic to the fishes than mosquito larvae showing the LC, value of Chinese muddy loaches at 24.145 pprn of Abate and 10.750ppm of Abate-S@. This fish species showed that the LCsos of Abate@ and Abate-S@ were 27.567 pprn and 14.775 ppm, respectively. In case of crucian carps, their LC, values were 7.914 pprn of Abate@ and 6.480 pprn of Abate-S@. Therefore, the maximum safe dosages of the insecticides to the fishes were 8 times as high as the values of LCg5 of the mosquito larvae. This study suggests that Abate@ and Abate-S@ demonstrated highly potential insecticides for further larger scale operational integrated control in some proper aquatic places if other aquatic invertebrates are also safe to the insecticides.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.137-143
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• 2000

The present study was performed to investigate the bioconcentration of phosphamidon and profenofos. The BCFs(bioconcentration factors), depuration rate constants and LC$_{50}$ for two pesticides in zebrafish(Brachydanio rerio) were measured by the flow-through system(OECD guideline 305). The results obtained are summarized as follows: The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC.n and 96-hrs LC$_{50}$ were more than 100 mg/l for phosphamidon. The concentration of phosphamidon in zebrafish reached an equilibrium in 12 hrs at low and high concentrations(0.2 mg/l and 1 mg/1). The average BCF values of phosphamidon were less than 1 at low(0.96, n=7) and high concentrations (0.89, n=7) after 12~168 hrs. Depuration rate constants of phosphamidon were 0.18 hr-1 and 0.21 hr-1, half-life of phosphamidon were 3.85 and 3.30 at low and high concentrations(0.2 mg/l and 1 mg/l), respectively, The concentrations of phosphamidon in zebrafish at low and high concentrations were rapidly decreased after 8(0.04 $\mu\textrm{g}$/g) and 12 hrs(0.07 $\mu\textrm{g}$/g). The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC$_{50}$ and 96-hrs LC$_{50}$ were 2.9, 2.6, 2.2 and 2.0 mg/1 for profenofos. The concentration of profenofos in zebrafish reached an equilibrium in 12 hrs at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mgA and 0.02 mg/1). The average BCF values of profenofos were 141.9(n=7) and 111.3(n=7) at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mg/l and 0.02 mg/1) after 12~168 hrs. Depuration rate constants of profenofos were 0.09 hr$^{-1}$ and 0.10 hr$^{-1}$, half-life of profenofos were 7.70 and 6.93 at five-hundredth and one-hundredth concentration of 96-hrs LC50(0.004 mg/l and 0.02 mg/1), respectively. The concentrations of profenofos in zebrafish at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$ decreased agter 8(0.18 $\mu\textrm{g}$/g) and 12 hrs (0.19 $\mu\textrm{g}$/g). The LC$_{50}$ value in zebrafish showed that acute toxicity of profenofos was higher than that of phosphamidon. The BCF values of profenofos were 100 times higher than those of phosphamidon, and depuration rate of phosphamidon was two times faster than that of profenofos.