• Applied Microscopy
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• v.30 no.1
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• pp.45-59
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• 2000

Cis-platin is a widely used anticancer drug against certain solid tumors such as malignant ovarian tumor, malignant carcinoma of head and neck, bladder cancer and cervical cancer of uterus, and its major mechanism of action is inhibition of DNA synthesis of the tumor cell. To investigate the inhibitory effects of cis-platin on the ciliogensis of the ciliated cells in the mucosa of oviduct, the author pursued the alterations of $\alpha-tubulin$, which is the main constituent of the microtubles in cilia, after cis-platin treatment. To eliminate the possible variations due to ovarian cycle, female Spargue-Dawley rats ($150\sim200gm$ in B.W.) were pretreated with estradiol benzoate (20 mg/kg, once a day, for 4 consecutive days). Animals were administrated with cis-platin (6 mg/kg, i.p.) and sacrificed at 1day, 3days, 5days and 7days after treatment, respectively. Immunohistochemistry for $\alpha-tubulin$ using mouse anti-rat $\alpha-tubulin$ monoclonal antibody as primary antibody was done. Immunogold electronmicroscopy for intracellular distributions of $\alpha-tubulin$ was also performed with same primary antibody and Goat anti- mouse IgM which is preconjugated with gold particles of 15 nm as secondary antibody. The results obtained were as follows; 1. Strong immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1, 3 and 5 days after estradiol pretreatment. 2. Weak immunoreactivity of $\alpha-tubulin$ was observed in ciliated cells of oviducts at 1 and 3 days after cis-platin treatment but it was recovered to strong immunoreactivity in 5 days 3. In immunogold electronmicroscopy, density of gold particles for $\alpha-tubulin$ reactions was decreased in apical cytoplasm, but few changes were observed in basal body or cilia at 1 and 3 days after cis-platin treatment. From these above results, it is indicated that synthesis of $\alpha-tubulin$ in ciliated cells of rat oviduct is inhibited by cis-platin treatment.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.1-15
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• 2005

Pathogens, insects and weeds have significantly reduced agricultural productivity. Thus, to increase the productivity, synthetic agricultural chemicals have been overused. However, these synthetic compounds that are different from natural products cannot be broken down easily in natural systems, causing the destruction of soil quality and agricultural environments and the gradually difficulty in continuous agriculture. Now agriculture is faced with the various problems of minimizing the damage in agricultural environments, securing the safety of human health, while simultaneously increasing agricultural productivity. Meanwhile, plants produce secondary metabolites to protect themselves from external invaders and to secure their region for survival. Plants infected with pathogens produce antibiotics phytoalexin; monocotyledonous plants produce flavonoids and diterpenoids phytoalexins, and dicotylodoneous plant, despite of infected pathogens, produce family-specific phytoalexin such as flavonoids in Leguminosae, indole derivatives in Cruciferae, sesquitepenoids in Solanaceae, coumarins in Umbelliferae, making the plant resistant to specific pathogen. Growth inhibitor or antifeedant substances to insects are terpenoids pyrethrin, azadirachtin, limonin, cedrelanoid, toosendanin and fraxinellone/dictamnine, and terpenoid-alkaloid mixed compounds sesquiterpene pyridine and norditerpenoids, and azepine-, amide-, loline-, stemofoline-, pyrrolizidine-alkaloids and so on. Also plants produces the substances to inhibit other plant growths to secure the regions for plant itself, which is including terpenoids essential oil and sesquiterpene lactone, and additionally, benzoxazinoids, glucosinolate, quassinoid, cyanogenic glycoside, saponin, sorgolennone, juglone and lots of other different of secondary metabolites. Hence, phytoalexin, an antibiotic compound produced by plants infected with pathogens, can be employed for pathogen control. Terpenoids and alkaloids inhibiting insect growth can be utilized for insect control. Allelochemicals, a compound released from a certain plant to hinder the growth of other plants for their survival, can be also used directly as a herbicides for weed control as well. Therefore, the use of the natural secondary metabolites for pest control might be one of the alternatives for environmentally friendly agriculture. However, the natural substances are destroyed easily causing low the pest-control efficacy, and also there is the limitation to producing the substances using plant cell. In the future, effects should be made to try to find the secondary metabolites with good pest-control effect and no harmful to human health. Also the biosynthetic pathways of secondary metabolites have to be elucidated continuously, and the metabolic engineering should be applied to improve transgenics having the resistance to specific pest.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.407-415
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• 2013

In this study, we investigated the antioxidant activities on HaCaT and the whitening effects on B16F1 melanoma cells of Dendropanax morbifera leaf extract. In an antioxidative activity assay using HaCaT cells, the ethyl acetate ($50{\mu}g/ml$) and aglycone fractions ($25{\mu}g/ml$) of the D. morbifera leaf extract didn't exhibit any characteristics of cytotoxicity. When HaCaT cells were exposed to a single large dose ($800mJ/cm^2$) of UVB, the extracts protected the cells against UVB radiation. When HaCaT cells were treated with 10 mM $H_2O_2$ and $4{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/ml$) and aglycone ($6.25{\sim}25{\mu}g/ml$) fractions protected the cells against oxidative damage in a concentration dependent manner. When the whitening effects of D. morbifera leaf extract were tested in melanoma B16/F1 cells treated with the a-melanocyte stimulating hormone (${\alpha}$-MSH), the extracts inhibited ${\alpha}$-MSH-stimulated intra/extracellular melanogenesis in a concentration dependent manner. The inhibitory effects of the ethyl acetate and aglycone fractions of D. morbifera leaf extract were 21% and 44% at $25{\mu}g/ml$, respectively. Both are more effective than arbutin (15% at $25{\mu}g/ml$) which is known as a whitening agent. These results indicate that fractions of the D. morbifera leaf can function as cell protectants and natural antioxidants in biological systems, particularly skins exposed to UV radiation by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cells against ROS. In addition, fractions of the D. morbifera leaf can be applied to new whitening cosmetics because of their inhibitory effects on ${\alpha}$-MSH stimulated melanogenesis in B16F1 melanoma cells.

• Food Science and Preservation
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• v.19 no.1
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• pp.131-137
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• 2012

This study was carried out to investigate the physiochemical and microbiological changes of dandelion during fermentation. Thirty and fifty percentage raw sugar groups (SFE30 and SFE50) were introduced into dandelions and fermented for 120 days at $15-20^{\circ}C$. This study was conducted to investigate the utilization of sucrose on lactic acid bacteria from dandelions and their effect on the pH, titratable acidity, microorganism and formation of organic acids in dandelions during fermentation. The number of lactic acid bacteria increased remarkably up to 15 days of fermentation and then decreased rapidly thereafter. The maximum number of lactic acid bacteria, 7.9 log CFU/mL was reached at pH 4.17 and the pH of dandelion showed a slight decrease during fermentation and decreased steadily up to 90 days to reach an optimum pH of 4.0. The titratable acidity of dandelions fermented increased during fermentation. The concentration of organic acid, amino acid and free sugar in SFE30 was higher than both SFE50 and DWE. The results of dandelions fermented were remarkably retarded in the 50% raw sugar group compared to the 30% raw sugar group.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.1
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• pp.21-30
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• 1985

The tension leg platform (TLP) is a kind of compliant structures, and is also a type of moored stable platform with a buoyancy exceeding the weight because of having tensioned vertical anchor cables. In this paper, among the various kinds of tension leg structures, Deep Oil Technology (DOT) TLP was analyzed because it has large-displacement portions of the immersed surface such as vertical corner pontoons and small-diameter elongated members such as cross-bracing. It also has results of hydraulic model tests, comparable with theorectical analysis. Because of the vertical axes of symmetry in the three vertical buoyant legs and because there are no larger horizontal buoyant members between these three vertical members, it was decided to develop a numerical algorithm which would predict the dynamic response of the DOT TLP using the previously developed numerical algorithm Floating Vessel Response Simulation (FVRS) for vertically axisymmetric bodies of revolution. In addition, a linearized hydroelastic Morison equation subroutine would be developed to account for the hydrodynamic pressure forces on the small member cross bracing. Interaction between the large buoyant members or small member cross bracings is considered to be negligible and is not included in the analysis. The dynamic response of the DOT TLP in the surge mode is compared with the results of the TLP algorithm for various combinations of diffraction and Morison forces and moments. The results which include the Morison equation are better than the results for diffraction only. This is because the vertically axisymmetric buoyant members are only marginally large enough to consider diffractions effects. The prototype TLP results are expected to be more inertially dominated.

• The Journal of the Petrological Society of Korea
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• v.6 no.3
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• pp.210-225
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• 1997

From their general natures of peraluminous, S-type and ilmenite-series granites, two-mica granites in the Cheongsan, Inje-Hongcheon, Yeongju and Namwon areas were originated from crust-derived granitic magma and solidified under reducing condition. Each two-mica granite in Inje-Hongcheon and Namwon districts was differentiated from the the residual magma of porphyric biotite granite and high Ti/Mg biotite granite, respectively. The genetic relationships between two-mica granite and porphyritic biotite granite in Chenongsan district and between two-mica granite and biotite granodiorite in Yeongju district are ambiguous. In Namwon district granitic magmas were water-saturated and possible water solubilities in magmas were more than 5.8wt.%. In Yeongju district two-mica granitic magma was nearly water-saturated and showed possible water solubilities between 2.4~5.8wt.%. Two-mica granitic magmas in Cheongsan and Inje-Hongcheon districts were water-undersaturated. Pressure-dependent minimum melt compositions (0.5~2kb) and petrographic textures of two-mica granites in Inje-Hongcheon and Yeongju districts represent that the granites intruded and solidified at shallow level, whereas those in Cheongsan and Namwon districts exhibit relatively deeper level of granitic intrusion (2-3kb). The intersection of granite-solidus/muscovite stability indicates that magmatic primary muscovite can be crystallized from the water-saturated magma above 1.6kb (ca. 6km), but below the pressure muscovite can be formed by the subsolidus reaction. On the other hand, more pressure would be necessary for the crystallization of primary muscovite from the water-undersaturated magma. This pressure condition can explain the occurrence of primary and secondary muscovites from the two-mica granites in the areas considered. The experimental muscovite stability must be cautious of the application to examine the origin of muscovite. The muscovite stability can move toward high temperature field with adding of Ti, Fe and Mg components to the octahedral site of pure muscovite end member.

• Development and Reproduction
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• v.5 no.2
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• pp.175-180
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• 2001

The ectopic expression of gonadotropin releasing hormone(GnRH and luteinizing hormone(LH) in several tissues is a quite intriguing phenomenon. Recently, the presence of GnRH and its receptor has been clearly demonstrated in rodents and human mammary gland. In this context, one can postulate that the presence of local circuit composed of GnRH and LH in the gland. The present study was undertaken to elucidate whether there is a correlation between the LH expression in rat mammary gland and physiological status during the process of mammary differentiation. LH contents in mammary gland from cycling to weaning rats were measured by radioimmunoassay(RIA). In cycling rats, changes of the LH level in both serum and mammary gland showed similar pattern as the highest level in proestrus and the lowest level in diestrus II stage. While the serum LH levels were fluctuated from pregnant through involution stage, a sharp decline of mammary LH contents was observed in the lactating rats. This decrement was recovered in involuting rats to the level of proestrus stage. Reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analyses demonstrated that the transcriptional activities of the mammary LH and GnRH were increased from diestrus I stage to estrus stage, and the increased levels were maintained in pregnant, lactation and involution stages. To test the hypothesis that the alteration in mammary LH expression might be steroid-dependant, ovariectomy(OVX) and steroid supplement model was employed. As expected, supplement of estradiol(E$_2$) after OVX remarkably decreased serum LH level compared to that in serum from vehicle-only treated rats. Likewise, administration of E$_2$ significantly reduced the mammary LH content. The present study demonstrated that (i) the LH expression in mammary gland could be altered by some physiological parameters such as estrous cycle, pregnancy, lactation and involution, and (ii) ovarian steroid especially estrogen seems to be one of major endocrine factors which are responsible for regulation of mammary LH expression.

• Development and Reproduction
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• v.10 no.2
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• pp.147-154
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• 2006

Phthalates such as di(2-ethyl hexyl)phthalate(DEHP) are industrial chemicals with wide-ranging human exposures because of their use in plastics and other common consumer products. Consequently, their adverse effects as endocrine disruptor in the reproductive physiology of both laboratory rodents and human have been studied extensively. The present study was undertaken to examine whether prepubertal exposure to DEHP affects on the onset of puberty and the associated reproductive parameters such as hormone receptor expressions in female rats. DEHP(100mg/kg/day) was administered daily from postnatal day 25(PND 25) through the day when the first vaginal opening(VO) was observed, and the animals were sacrificed on the next day. Gross anatomy and weight of reproductive tissues were compared to test the DEHP's effects on the cell proliferation. Furthermore, histological studies were performed to assess the structural alterations in the tissues. Specific radioimmunoassay was carried out to measure serum LH levels. To determine the transcriptional changes in progesterone receptor(PR), total RNAs were extracted and applied to the semi-quantitative reverse transcription polymerase chain reaction(RT-PCR). As a result, delayed VO was shown in the DEHP group(PND $37.3{\pm}0.7$) compared to the control group(PND $35.3{\pm}0.7$; p<0.05). DEHP treatment significantly decreased the wet weight of ovaries and uteri compared to the control group(p<0.05). Interestingly, elevation of serum LH levels was shown in the DEHP group(p<0.05). Graafian follicles and corpora lutea were observed only in the ovaries from the control animals. Numerous primary, secondary follicles and small atretic follicles were observed in the ovaries from DEHP-treated animals. Similarly, hypotrophy of luminal and glandular uterine epithelium was found in the DEHP-treated group. These effects were probably due to the inhibitory effects of DEHP on the synthesis and secretion of estrogen from granulosa cells. In the semiquantitative RT-PCR studies, the transcriptional activities of PR in both ovary(p<0.05) and uterus(p<0.01) from DEHP-treated animals were significantly lower than those from the control animals. The present studies demonstrated that the acute exposure to DEHP during the critical period of prepubertal stage could inactivate the reproductive system resulting delayed puberty in female rats.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.142-149
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• 2011

An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 ${\mu}g$/kg and 18.8 ${\mu}g$/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients $r^2$ of 0.9999 in the concentration range from 20 to 500 ${\mu}g$/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 ${\mu}g$/kg were $82{\pm}2.7%$ and $87{\pm}1.3%$% in dried noodle, and $97{\pm}1.6%$ and $91{\pm}12.0%$ in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 ${\mu}g$/kg and 500 ${\mu}g$/kg were estimated to be $163.8{\pm}52.1$ and $435.2{\pm}91.6\;{\mu}g$/kg for dried noodle, and $194.3{\pm}33.0$ and $453.2{\pm}91.1\;{\mu}g$/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.2
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• pp.120-128
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• 1976

Two experiments were conducted to study the nature of protein degradation in fish muscle postmortem, first one with English sole (Paraphyrus vetulus) followed by another with rockfish (Sebastodes spp.). In the first one, proteolysis was measured by the increase of amino-N in gutted fish during storage in ice and in the homogenates prepared from fish of different ice storage during $20^{\circ}C-incubation$. In order to test the possible involvement of fish muscle a cathepsin, a portion of each homogenate sample was exposed to 0.5 Mrad of gamma radiation to destroy viable microorganisms prior to the incubation. Proteolysis was not detected until viable count reached a level above $10^7$ cells per gm fish flesh, corresponding to 31 days of ice storage. Even if fish flesh were mechanically disrupted by means of homogenization and subsequently incubated at $20^{\circ}C$, proteloysis attributable to muscle cathepsin was not detected. In the second with rockfish muscle aseptically prepared from freshly killed fish, the samples were inoculated with a proteolytic strain of fish spoilage Pseudomonad or irradiated at 0, 0.5 and 3.0 Mrad. The four samle groups were stored at $0-2^{\circ}C$ to compare the spoilage pattern of sterile and non-sterile muscle. In sterile muscle both total-N (extracted in 0.5M KCl) and amino-N $(soluble\;in\;70\%\;ethanol)$ declined slightly while the inoculated muscle showing increase in parallel with the increase of number of inoculated bacterium. The results indicate that proteolysis is a part of normal fish spoilage and the onset of proteolysis is delayed until viable count reaches its maximum level. Contribution of fish muscle cathepsin to protein degradation in white flesh fish muscle post-mortem is nil.