• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.34-36
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• 2002

Epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) have been shown to stimulate proliferation and differentiation of various somatic cells, including placental trophoblasts and also to enhance fetal growth and development when maternally administered. Since an increase of the expression of placental EGF and IGF-I receptors in rat, mouse, and human with the gestation advanced, both EGF and IGF-I were considered to play pivotal roles on fetal growth by regulating some function of placental cells. Amino acids are crucial importance for both maternal and fetal requirements of energy source and essential constituent of fetal mass during pregnancy. Impaired fetal and placental uptake of amino acids has been observed in several models of growth retardation in the rat. Amino acid is concentrated in the fetal side through active transport by amino acid transporters and is one of the important metabolic fuels for the fatal growth. Therefore, at first plasma amino acid concentrations in mothers and fetuses were measured as an index of uphill transport across the placenta associated with EGF and IGF-1. The EGF administration at the concentration of 0, 0.1, or 0.2 $\mu\textrm{g}$/g to pregnant rats from day 18 to 21 of gestation apparently increased fetal/maternal ratio of serum proline concentration and also fatal growth in EGF dose-dependent manner. When IGF-I in doses of 0, 1, 2, and 4 $\mu\textrm{g}$/g were administrated, the ratio of leucine, isoleucine, tryptophan, phenylalanine, tyrosine and also fetal growth significantly increased with a dose-dependent manner. These results suggested that EGF and IGF-I enhanced fatal growth by, as one of its possible mechanisms, promoting placental activity to transfer some amino acid supplies from the mother to the fetus in late pregnancy.

• Animal Systematics, Evolution and Diversity
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• v.11 no.3
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• pp.359-377
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• 1995

Morphological and isozyme analyses were used to examine closely related species of Tridentiger obscurus and \ulcorner: brevispinis, a pair of cryptic species which has intricate problem with regard to species boundary, and to clarify the taxonomic position. In this study, it was revealed from their 17 allopatric streams that there are differences of band ornamentation on the lateral side and three genetic markers between two species. However, genetic relationship between them (S = 0.813, D = 0.192) was within the intraspecific level of similarity. However, at the sympatry of two species no hybrid was found except at Bangjuk stream where the electrophoretic hybrids with slight deficiency of heterozygosity were observed. It is shown that at sympatry there is a finer microenvironmental subdivision between two species at all populations including Bangjuk stream. To manifest the extent of assortative mating, four syrnpatric subpopulations at Bangjuk stream were analyzed for departure from Hardy-Weinberg equillibrium by F-statistics. All subpopulations were deviated significantly from the expectation under random mating. The evidences presented here supports the recognition of Tridentiger obscurus and T. brevispinis as semispecies in the late stage of reproductive isolation

• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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• pp.279-290
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• 2012

Plecoglossus altivelis (ayu) is an amphidromous fish widely distributed in Northeastern Asia from the East China Sea to the northern Japanese coastal waters, encompassing the Korean Peninsula within its range. The shore lines of northeastern region in Asia have severely fluctuated following glaciations in the Quaternary. In the present study, we investigate the population genetic structure and historical demographic change of P. altivelis at a population level in East Asia. Analysis of molecular variance (AMOVA) based on 244 mitochondrial control region DNA sequences clearly showed that as the sampling scope extended to a larger geographic area, genetic differentiation began to become significant, particularly among Northeastern populations. A series of hierarchical AMOVA could detect the genetic relationship of three closely located islands between Korea and Japan that might have been tightly connected by the regional Tsushima current. Neutrality and mismatch distribution analyses revealed a strong signature of a recent population expansion of P. altivelis in East Asia, estimated at 126 to 391 thousand years ago during the late Pleistocene. Therefore it suggests that the present population of P. altivelis traces back to its approximate demographic change long before the last glacial maximum. This contrasts our a priori expectation that the most recent glacial event might have the most crucial effect on the present day demography of marine organisms through bottleneck and subsequent increase of effective population size in this region.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5161-5165
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• 2012

Background: There are few molecular markers known to predict cholangiocarcinoma (CCA) prognosis. Smad7 has a certain relationship with epithelial-mesenchymal transition (EMT), but its relevance to CCA in unclear. Therefore expression and clinical significance of Smad7 in CCA was the focus of this study. Methods: Expression of Smad7, E-cadherin and vimentin was assessed in 41 patients with CCA by immunohistochemistry and analyzed for associations with clinical parameters. Results: Smad7 and vimentin expression in the CCA tissue was dramatically higher than that in adjacent tissues. In addition, Smad7, vimentin and E-cadherin expression was significantly associated with CCA lymph node metastasis and perineural invasion($P{\leq}0.05$), but not other factors, such as gender, age, tumor location, tumor type and tumor differentiation degree (P>0.05). The overall survival and relapse-free survival rate was significantly higher in patients with negative Smad7 expression than those with positive Smad7 expression. Conclusion: EMT phenomena may occur in the process of CCA invasion and metastasis. Smad7, which was highly expressed in CCA, may be considered to be one feedback regulator in late stages and could have potential as a prognostic indicator for clinical assessment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.707-716
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• 2020

Red sea cucumber Stichopus japonicus, was dried using three methods-far-infrared ray, vacuum, and freeze drying and then enzymatically hydrolyzed using nine proteases: Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex, trypsin, α-chymotrypsin, and papain. In addition, the potential ability of hydrolysates to inhibit lipid accumulation in 3T3-L1 adipocytes was evaluated. The yield of hydrolysates from red sea cucumbers dried using each method was higher than that of the distilled water extract, and protein contents were either similar or higher. The hydrolysates that exhibited inhibitory effects on lipid accumulation, as demonstrated via Oil red O staining, were those obtained by far-infrared ray drying coupled with Alcalase, Flavourzyme, Kojizyme, or Neutrase treatment. In addition to the advantages of far-infrared drying and the characteristics of Flavourzyme, the Flavourzyme hydrolysate of far-infrared-dried red sea cucumber showed the highest inhibitory effect on lipid accumulation. In addition, this hydrolysate significantly decreased the expression of the protein factor fatty acid-binding protein 4, which is related to the late differentiation of 3T3-L1 adipocytes. Taken together, these results suggest that Flavourzyme hydrolysates from farinfrared-dried red sea cucumber may be used as a functional food and/or a pharmaceutical ingredient for the inhibition of lipid accumulation.

• Applied Microscopy
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• v.29 no.4
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• pp.499-509
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• 1999

Accumulations of the storage proteins in protein storage vacuole and the differentiation of protein bodies from protein-filled ER in developing pea cotyledons have been investigated using conventional and immunoelectron microscopy. To improve the fixation quality, single cells separated enzymatically from sliced cotyledons were used. At early stages of seed development osmiophilic protein accumulates in rER lumen were observed quite often. This protein-filled ER cisternae were differentiated into cytoplasmic protein bodies at late stage by the process called terminal dilations which have been considered a principal route of the formation of cytoplasmic protein bodies somewhat later in seed maturation. Immunocytochemical labellings of the vicilin and legumin show that presence of vicilin on both of the cytoplasmic PB and PD, but limited presence of legumin only on the cytoplasmic PB at intermediate stage of seed development. Immunogold labellings of Bip, ER retention protein, were observed on the inner periphery of protein deposits in protein storage vacuole. This result was regarded that Bip can recognize and retrieve misfolded protein during active accumulation of storage protein to the PD in PSV.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.395-404
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• 1995

In order to study the process of spermiogenesis of the korean striped field mouse Apodemus agrorfus coreae, the cell differentiation of seminiferous epithelium and morphological features of mature sperm in cauda epididymis was examined and the results are as follows: Spermiogenesis was divided, according to the features of cell structure; Golgi, cap, acrosome and spermiation phases were further subdivided into two steps of early and late phases respectively, and maturation phase has only one step. Hence, the spermiogenesis consists of nine phases. in the changes of the chromatin in nucleus, the chromatin granules began to be condensed in the cap phase and the condensation proceeded to form a globular of nucleus at the acrsome phase. Finally, the chromatin regularization was completed and perfect nucleus of sperm was formed at the maturation phase. Sperm head had the falciform, and the outer dence fibers of middle piece were arranged in a horseshoe fashion. The outer dence fiber number 1, 5, 6 and 9 was larger than other fiber number 2, 3, 4, 7, 8.

• Journal of the Economic Geographical Society of Korea
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• v.1 no.1
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• pp.33-56
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• 1998

This study examines the characteristics of service economies and their impacts on the spatial transformation of Korea during the last IS years. This study reviews the different perspectives for the tertiarization Process. It focuses on the spatial variation in the growth and location of Producer service industries. Based on the analyses of industrial and occupational compositions, services. particularly producer services, have played a major role in creating new job opportunities since the late 1980s. The ratio of services to merchandise trade is approximately 1:4, but service trades have increased since the early 1990s. Producer service activities have grown very rapidly, and the information processing service has been over-concentrated in Seoul. Further headquarters of bank and insurance services are overwhelmingly concentrated into Seoul. The firms whose headquarters are located in Seoul have linkage Pattern on a nationwide scale. The pattern of employment growth in producer services shows a clear core-Periphery disparity. In the light of the observed pattern of regional differentiation in producer service employment, some wider implications of the distribution of producer service activities for regional economic Performance are considered.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.121-130
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• 2014

Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis was adopted to explore rapid differentiation in the diversity and dynamics of bacteria in kimchi made in Korea and China for future application in kimchi origin discrimination. T-RFLP analysis supported the reproducible and rapid detection of major lactic acid bacteria known to be involved in kimchi fermentation. The taxonomic resolution level of this T-RFLP analysis was between the species and genus level, but was not specific enough for the detection of a bacterium found only in one origin, either Korea or China. The bacterial community structure successions in kimchi samples from Korea and China analyzed by T-RFLP analysis occurred with a similar pattern. Bacillus spp. which were not detected in the early microbial studies of kimchi were constantly detected until the late fermentation stage of kimchi in our T-RFLP analysis and their existence was proved by culture-based identification. Additionally, sporulation of Bacillus spp. during kimchi fermentation was discovered.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.2
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• pp.91-97
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• 2009

The tubby mouse is characterized by progressive retinal and cochlear degeneration and late-onset obesity. These phenotypes are caused by a loss-of-function mutation in the tub gene and are shared with several human syndromes, suggesting the importance of tubby protein in central nervous system (CNS) functioning. Although evidence suggests that tubby may act as a transcription factor mediating G-protein coupled receptor (GPCR) signaling, any downstream gene regulated by tubby has yet to be identified. To explore potential target genes of tubby with region-specific transcription patterns in the brain, we performed a microarray analysis using the cerebral cortex and hypothalamus of tubby mice. We also validated the changes of gene expression level observed with the microarray analysis using real-time RT-PCR. We found that expression of erythroid differentiation factor 1 (Erdrl) and caspase 1 (Casp1) increased, while p21-activated kinase 1 (Pak1) and cholecystokinin 2 receptor (Cck2r) expression decreased in the cerebral cortex of tubby mice. In the hypothalamic region, Casp 1 was up-regulated and $\mu$-crystallin (CRYM) was down-regulated. Based on the reported functions of the differentially expressed genes, these individual or grouped genes may account for the phenotype of tubby mice. We discussed how altered expression of genes in tubby mice might be understood as the underlying mechanism behind tubby phenotypes.