• The Korean Journal of Zoology
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• v.35 no.2
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• pp.144-148
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• 1992

Insulin and transfenin (Tf) were found to be essential for suwival and differentiation of brain neuroblasts obtained from chick embryo. This requirement, however, is Changed from insulin to Tf upon neuronal development of the embryo, and this phenomenon is due to the changes in the levels of corresponding receptors. Using cultured neuroblasts, the level of Tf receptor is also found to increase Lvhile that of insulin receptor falls dramatically during the course of the cell differentiation. These results suggest that the development-specific changes in the levels of insulin and Tf receptors in embryo can be reproduced in the culture system during the differentiation period. Because the culture system used was a defined medium and contained no other macromolecules than insulin and Tf, it appears possible that insulin and Tf may act as signalling molecules in the control of neuronal development.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.1
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• pp.1-4
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• 2003

In this study, we showed that neurons could be generated from adult canine bone marrow stem cells by culturing with $DMSO/BHA/FeCl_2$. These neurons differentiated from the bone marrow stem cells formed neurites, expressed neuron-specific markers. This differentiation was enhanced by $FeCl_2$. These results suggest that iron can effectively initiate differentiation of adult bone marrow stem cells into neurons.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.9-13
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• 1998

Visual system of Korean Salamander(Hynobius leechi) was morphologically studied. Fertilized eggs in egg sacs were collected and were developed in sterile saline solution. Various sized larvae of 5-30mm in length were fixed. Specimens were paraffin sectioned and were observed under light microscope. In 5mm length larva, lens rudiment induced by optic cup was combined with sensory ectoderm. The shape of lens was changed as spherical in 12mm length larva, but the retinal layer did not differentiated into three layers. The differentiation of retinal layer was clear in 14-16mm length larva. The central region of lens fibers was degenerated. Iris and ciliary body were formed from the marginal zone of optic cup in 20mm length larva. Choroid was thicker in elder eye of 30mm length larva and cartilage developed at outer region of optic cup. The outer segment of photoreceptor cell layer grew longitudinally. Optic nerve was connected to the ventral part of brain through cartilage.

• Journal of the Korean Regional Science Association
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• v.34 no.3
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• pp.43-54
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• 2018

This paper analyzes the effects of population aging on regional differentiation from the New Economic Geography perspective. The addition of old-age population variable affects the price index, income, nominal wage, and real wage derived in the short-run equilibrium. Using the new model, we can better explain industrial agglomeration patterns corresponding to the new long-run equilibrium. As the real wage criterion does not properly take the old-age group into account, we employ the indirect utility function as an additional condition for equilibrium. We further consider tax as a policy tool for achieving a better long-run equilibrium. This would enable the government to direct the economy toward a particular equilibrium desired in the face of population aging.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.620-624
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• 2016

The Wnt/β-catenin signaling pathway is mandatory in adipogenesis. In this study, we investigated the applicability of functional materials for the treatment of obesity by examining Wnt/β-catenin pathway reporter activity related to adipocyte differentiation inhibiting with korean native plant extracts. The luciferase activity of HEK 293-TOP cells increased the reporter activity approximately 152% and 130% by treatment with Sanguisorba officinalis and Thuja orientalis, respectively. Ricinus communis were represented about 90% higher activity, two samples(Rosa rugosa and Sophorae Flos) showed 80% higher activity than the control. Three samples of plant extracts (Zanthoxylum piperitum, Pueraria thunbergiana, Solanum nigrum) were about 70% higher activity compared with the non-treated control. Cytotoxicity of plant extracts was not detected in the rat neural stem cells. These results suggest that the selected eight plant extracts are safe compounds. Our findings indicate that Wnt/β-catenin pathway reporter activity could be used for high throughput screening system. In addition, the plant extracts selected as candidates for adipocyte differentiation inhibiting may be potential therapeutic agents for obesity, it will be exploring the possibility of developing an anti-obesity materials through further experiments with selected plant extracts.

• Journal of Dairy Science and Biotechnology
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• v.34 no.1
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• pp.1-7
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• 2016

Colostrum, a nutrient-rich fluid produced by female mammals after giving birth, is the specific initial diet of mammalian neonates. Colostrum is important for the nutrition, growth, and development of newborn infants and contributes to the immunologic defense of neonates. It contains immunoglobulins, antimicrobial peptides, such as lactoferrin and lactoperoxidase, and other bioactive molecules, including growth factors, such as IGF (insulin-like growth factor), EGF (epithermal growth factor), $TGF-{\beta}$ (transforming growth factor), and FGF (fibroblast growth factor). Bovine colostrum is a rich source of growth factors, which play a central role in wound healing. The biological activities of colostrum emphasize the relevance of the synergistic activity of growth factors to stimulate keratinocyte proliferation and migration, which are essential for tissue repair. Colostrum increases the expression of early differentiation markers, such as keratin 1 and 10 and involucrin, and late differentiation markers, including loricrin and filaggrin. Additionally, colostrum increases granulation tissue volume in the dermis, suggesting that it has a beneficial effect on wound healing. The therapeutic use of colostrum or individual peptides present in colostrum has a positive and curative influence on various gastrointestinal diseases.

• The Korean Journal of Zoology
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• v.27 no.2
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• pp.73-84
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• 1984

In order to investigate the effect of neurotransmitter on myoblast differentiation in vitro, the effects of dopamine and epinephrine on myoblast fusion and on the intracellular cAMP level in cultured myoblasts were examined. Dopamine $(3\\times10^{-5}M)$ and epinephrine $(3\\times10^{-5}M)$, when added at 34 hr after cell plating, markedly inhibited myoblast fusion, and dopamine was more potent than epinephrine. Both dopamine and epinephrine had no effect on intracellular cAMP level. At the same time, exogeneous dbcAMP, $PGE_1$, and aspirin were used to examine whether cAMP is involved in myoblast differentiation. dbcAMP $(1\\times10^{-4}M)$ inhibited myoblast fusion, whereas $PGE_1 (3\\times10^{-6}M)$ had no inhibitory effect, rather enhancing myoblast fusion. Aspirin, an inhibitor of PG synthetase, was shown to inhibit myoblast fusion. Possible mechanism by which dopamine or epinephrine at a specific concentration used inhibits myoblast fusion is discussed.

• Journal of Gastric Cancer
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• v.7 no.3
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• pp.160-166
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• 2007

Purpose: Recently, chemosensitivity tests have become widely used for the selection of effective drugs in gastric cancer patients. In this study, a chemosensitivity test was performed to select agents to increase the effectiveness of adjuvant chemotherapy. Materials and Methods: Chemosensitivity testing was performed in 81 gastric cancer patients that received a gastrectomy at the Yeungnam University Hospital. An ATP (adenosine triphosphate) based chemotherapy response assay was used. Clinicopatholgical factors such as sex, age, expression of tumor markers (CEA and CA19-9 levels), location of the tumor, morphology of advanced cancer, histological type, cell differentiation, depth of invasion, Lauren classification, Ming classification, lymphatic invasion, vascular invasion, neural invasion, lymph node metastasis and TNM stage were used to correlate the chemosensitivity and clinicopathological factors. Results: The most effective antitumor agents in gastric cancer patients were (in order of effectiveness) 5-FU, Epirubicin, lrinotecan and Oxaliplatin in our series. The chemosensitivity test showed a significant difference in susceptibility according to clinicopathological factors. Conclusion: Further studies on multidrug therapy are needed to evaluate synergistic effects of drugs. Therefore, for effective chemotherapy, it is more efficacious to select a chemosensitive drug than continue to use the same drug regimen.

• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.502-510
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• 1992

Background: Neuron specific enolase (NSE) is a neuronal form of the glycolytic enzyme enolase which was first found in extracts of brain tissue, and later in a variety of APUD cells and neurons of the diffuse endocrine system. SCLC shares many APUD properties with normal neuroendocrine cells. NSE immunostaining and serum NSE measurement may be a useful marker of neuroendocrine differentiation in lung tumors and diagnosis of small cell carcinoma. Methods: NSE immunohistochemical staining was done and at the same time serum NSE levels were measured in 22 small cell lung cancer and 21 non small cell lung cancer which were confirmed histologically. Results: 1) NSE immunoreactivity was detected in 9 of the 18 (50%) small cell lung cancer, in 5 of the 16 non small cell lung cancer. 2) Whereas the mean value in non-small cell lung cancer group was $11.79{\pm}4.47\;ng/ml$, the mean level of serum NSE in small cell lung cancer increased up to $59.3{\pm}77.8\;ng/ml$. In small cell lung cancer patients, mean value of limited disease group was $20.19{\pm}12.91\;ng/ml$, while mean value of extended disease group was $91.9{\pm}94.2\;ng/ml$ showing statistically significant difference. If serum levels above 20 ng/ml were tentatively defined as positive, 16 of 22 (73%) patients with SCLC had positive serum NSE level, but only one patient with NSCLC did. There was no correlation between serum NSE level and immunoreactivity of NSE. Conclusion: These studies indicate that serum NSE measurement may be a useful marker for the diagnosis and disease extent and NSE immunostaining can be used to demonstrate the neuroendocrine components of lung tumor.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.363-370
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• 2005

Neural stem cells (NSCs) of the central nervous system (CNS) have raised a great interest not only for their importance in basic neural development but also for their therapeutic potentials in neurologically degenerative diseases such as Parkinson's, Alzheimer and stroke. During the CNS development, two molecular cascades determine specification of midbrain dopamine system. In one pathway, FGF-8, sonic hedgehog and transcription factor Nurr1 specify dopamine neurotransmitter phenotype. In the other, transcription factors $Lm{\times}lb\;and\;Pt{\times}3$ are required for induction of dopaminergic neurons. In Nurr1 knockout mouse, tyrosine hydroxylase (TH) positive cells fail to appear in substantia nigra, indicating that Nurr1 is essential in specification of dopaminergic cell phenotype. In this study, we used the immortalized human NSCs retrovirally transduced with Nurr1 gene to probe the Nurr1 mediated mechanism to induce dopamine phenotype. While Nurr1 over-expression alone did not generate dopamine phenotype in NSCs, applications of retinoid and forskolin induced expression of TH and AADC mRNAs. In addition, co-cultures of Nurr1 expressing NSCs with human astrocytes induced a marked increase of TH expression. In this co-culture system, the addition of retinoid and forskolin dramatically increased expression of TH. These results indicate that the immortalized human NSCs with Nurr1 gene could have a clinical utility for cell replacement for the Parkinson patients.