• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.191-195
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• 2004

Arabidopsis NDPK2 (AtNDPK2) is a key singaling component that regulate cellular redox state and known to enhance multiple stress tolerance when over-expressed in Arabidopsis plant (Moon et al. 2003). In order to develop transgenic potato plants with enhanced tolerance to multiple stresses, we placed an AtNDPK2 cDNA under the control of a stress-inducible SWPA2 promoter or enhanced CaMV 35S promoter. Transgenic potato plants (cv. Superior and Atlantic) were generated using an Agrobacterium-mediated transformation system and selected on MS medium containing 100 mg/L kanamycin. Genomic Southern blot analysis confirmed the incorporation of AtNDPK2 cDNA into the potato genome. When potato leaf discs were treated with methyl viologen (MV) at 10 $\mu$M, transgenic plants showed higher tolerance to MV than non-transgenic or vector-transformed plants. The NDPK2 transgenic potato plants will be further used for analysis of stress-tolerance to multiple environmental stresses.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.116-122
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• 2003

Pleomorphic adenoma is the most common salivary neoplasm mainly occurring in the major salivary glands - especially in parotid gland, which is characterized by variable histopathologic appearances and high recurrence rate with malignant transformation according to surgical situations. And this benign mixed tumor occurring in minor salivary glands is believed to shows same clinicopathologic appearances and relatively low recurrent rate compared with the case in major salivary glands. But there are few comparative studies of large series of pleomorphic adenoma occurring in minor salivary glands which includes different histopathologic appearance, clinical characteristics, treatment methods, recurrence rate, and malignant transformation. We retrospectively studied the 54 patients who were pathologically confirmed with pleomorphic adenoma occurring in minor salivary glands, and analyzed the clinico-histopathological appearance, surgical methods, recurrent cases. The results obtained are as follows. 1. The incidence of the tumor was most frequent in 4th & 5th decade, and in female. 2. Palate(90%) including hard & soft palate was the most frequent site for pleomorphic adenoma in minor salivary glands. 3. The exact duration could not be known due to asymptomatic slow growth patterns of the tumor. 4. The mean tumor size was 2.3cm. 5. 28 (52%) pleomorphic adenomas were classified as Cellular type (cell-rich), 17 (31%) specimen as Intermediate type(equal cell to stroma ratio), and 9 (17%) as Myxoid type(stroma-rich). 6. Surgically 51 cases (94%) were showed well-encapsulated tumors, but histopathologically only 34 specimen (63%) were wellencapsulated. Therefore pleomorphic adenomas in minor salivary glands also have to be excised more widely, not enucleated. And in case of suspicious malignancy or large tumor, preoperative incisional biopsy can be applied in the center of the tumor for prevention of rupture of tumor cell, and total excision with use of frozen biopsy for detection of malignancy and confirming the excision margin, and closed follow-up according to final histopathologic results is recommended.

• Molecules and Cells
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• v.25 no.2
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• pp.231-241
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• 2008

Indole glucosinolates (IG) play important roles in plant defense, plant-insect interactions, and stress responses in plants. In an attempt to metabolically engineer the IG pathway flux in Chinese cabbage, three important Arabidopsis cDNAs, CYP79B2, CYP79B3, and CYP83B1, were introduced into Chinese cabbage by Agrobacterium-mediated transformation. Overexpression of CYP79B3 or CYP83B1 did not affect IG accumulation levels, and overexpression of CYP79B2 or CYP79B3 prevented the transformed callus from being regenerated, displaying the phenotype of indole-3-acetic acid (IAA) overproduction. However, when CYP83B1 was overexpressed together with CYP79B2 and/or CYP79B3, the transformed calli were regenerated into whole plants that accumulated higher levels of glucobrassicin, 4-hydroxy glucobrassicin, and 4-methoxy glucobrassicin than wild-type controls. This result suggests that the flux in Chinese cabbage is predominantly channeled into IAA biosynthesis so that coordinate expression of the two consecutive enzymes is needed to divert the flux into IG biosynthesis. With regard to IG accumulation, overexpression of all three cDNAs was no better than overexpression of the two cDNAs. The content of neoglucobrassicin remained unchanged in all transgenic plants. Although glucobrassicin was most directly affected by overexpression of the transgenes, elevated levels of the parent IG, glucobrassicin, were not always accompanied by increases in 4-hydroxy and 4-methoxy glucobrassicin. However, one transgenic line producing about 8-fold increased glucobrassicin also accumulated at least 2.5 fold more 4-hydroxy and 4-methoxy glucobrassicin. This implies that a large glucobrassicin pool exceeding some threshold level drives the flux into the side chain modification pathway. Aliphatic glucosinolate content was not affected in any of the transgenic plants.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.37-48
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• 2010

[ ${\Delta}^1$ ]pyrroline-5-carboxylate synthetase (P5CS) is a proline biosynthetic pathway enzyme and is known for conferring enhanced salt and drought stress in transgenics carrying this gene in a variety of plant species; however, the wild-type P5CS is subjected to feedback control. Therefore, in the present study, we used a mutagenized version of this osmoregulatory gene-P5CSF129A, which is not subjected to feedback control, for producing transgenic indica rice plants of cultivar Karjat-3 via Agrobacterium tumefaciens. We have used two types of explants for this purpose, namely mature embryo-derived callus and shoot apices. Various parameters for transformation were optimized including antibiotic concentration for selection, duration of cocultivation, addition of phenolic compound, and bacterial culture density. The resultant primary transgenic plants showed more enhanced proline accumulation than their non-transformed counterparts. This proline level was particularly enhanced in the transgenic plants of next generation ($T_1$) under 150 mM NaCl stress. The higher proline level shown by transgenic plants was associated with better biomass production and growth performance under salt stress and lower extent of lipid peroxidation, indicating that overproduction of proline may have a role in counteracting the negative effect of salt stress and higher maintenance of cellular integrity and basic physiological processes under stress.

• Journal of Korea Foundry Society
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• v.23 no.5
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• pp.276-285
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• 2003

In the undercooled melt of $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy, the solidification behavior including nucleation and growth of crystals at the micrometer level has been observed in-situ by use of a confocal scanning laser microscope combined with an infrared image furnace. The $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy specimens were cooled from the liquid state to glass transition temperature. 575 K, at various cooling late under a helium gas flow. According to the cooling rate, the morphologies of the solidification front are changed among various types, irregular jog like front, columnar dendritic front, cellular grain, star like shape jog and fine grain, etc. The velocities of the solid-liquid interface are measured to be $10^{-5}{\sim}10^{-8}$ m/s which are at least two orders higher than the theoretical crystal growth rates. Combining the morphologies observed in terms of cooling rates and their solidification behaviors, we conclude that phase separation takes place in the undercooled molten $Pd_{40}Cu_{30}Ni_{10}P_{20}$ alloy. The continuous cooling transformation (CCT) diagram was constructed from solidification onset time at various linear cooling conditions with different rate. The CCT diagram suggests that the critical cooling rate for glassy solidification is about 1.5 K/s, which is in agreement with the previous calorimetric findings.

• Molecules and Cells
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• v.42 no.2
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• pp.113-122
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• 2019

Communications at the interface between the apical membrane of follicular cells and the follicular lumen are critical for the homeostasis of thyroid gland. Primary cilia at the apical membrane of thyroid follicular cells may sense follicular luminal environment and regulate follicular homeostasis, although their role in vivo remains to be determined. Here, mice devoid of primary cilia were generated by thyroid follicular epithelial cell-specific deletion of the gene encoding intraflagellar transport protein 88 (Ift88). Thyroid follicular cellspecific Ift88-deficient mice showed normal folliculogenesis and hormonogenesis; however, those older than 7 weeks showed irregularly dilated and destroyed follicles in the thyroid gland. With increasing age, follicular cells with malignant properties showing the characteristic nuclear features of human thyroid carcinomas formed papillary and solid proliferative nodules from degenerated thyroid follicles. Furthermore, malignant tumor cells manifested as tumor emboli in thyroid vessels. These findings suggest that loss-of-function of Ift88/primary cilia results in malignant transformation from degenerated thyroid follicles.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.295-305
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• 2001

Protein kinase C (PKC) is known to play a pivotal role in neoplastic transformation cells and its high expression is often found in a variety of types of tumors including oral cancer. While PKC is associated with the altered signal transduction pathway of the tumor cells, it is still unclear which isoform is involved in the carcinogenesis process. Since the cellular distributions and the roles of PKC are isoform-specific, it is very important to identify the specific target molecules to improve our understanding of the carcinogenesis processes. Thus, the present study attempted to perform chemical carcinogen-induced neoplastic transformation of human epithelial cells and analyze the specific isoform of PKCs involved in the cellular transformation. The study analyzed overall PKC responses upon MNNG(N-Methyl-N'-nitro-N-nitroso guanidine) exposure with [$^3H$] PDBu binding assay. PKC translocation was observed at high doses of MNNG treatment in the presence of extracellular calcium. Such effects were not observed in the absence of extracellular calcium. Translocational effects with exposure of MNNG was further enhanced in the presence of hydrocortisone. The result suggests that the type of PKC involved may be $Ca^{2+}$-dependent classical isoform and steroid hormone enhances PKC activation. Among cPKC isoforms examined, only $PKC-{\alpha}$ and r showed significant translocation of protein levels from cytosolic fraction to membrane fraction, as analyzed by immunoblot. $PKC-{\varepsilon}$ in nPKC class showed an inch·eased translocation, but other forms in this class did not show the effect. None of isoforms in aPKC class was affected by MNNG treatment. The study demonstrated that there was a certain specificity in the patterns of isoform induction follwong chemical carcinogen exposure and helped identify all the types of PKC isoforms expressed in human epithelial cells. It was revealed that PKC isoforms were activated in an early resonse to chemical carcinogen, suggesting that PKC be associated with carcinogenesis process from an early stage in this particular cell system. The study will contribute to improving our understanding of chemical-induced carcinogenesis in human cells and may provide a scientific basis to introduce the specific PKC inhibitors as an anticancer drug of epithelial cell-origin cancers including oral cancer.

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.511-519
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• 2006

Background: Loss of cardiomyocytes in the myocardial infarction leads to regional contractile dysfunction, and necrotized cardiomyocytes in infracted ventricular tissues are progressively replaced by fibroblasts forming scar tissue. Although cardiomyoplasty, or implantation of ventricular assist device or artificial heart was tried in refractory heart failure, the cardiac transplantation was the only therapeutic modality because these other therapeutic strategies were not permanent. Cell transplantation is tried instead of cardiac transplantation, especially bone marrow is the most popular donated organ. But because bone marrow aspiration procedure is invasive and painful, and it had the fewer amounts of cellular population, the adipose tissue is recommended for harvesting of mesenchymal stem cells. Material and Method: After adipose tissues were extracted from abdominal subcutaneous adipose tissue and intra-abdominal adipose tissue individually, the cellular components were obtained by same method. These cellular components were tried to transformation with the various titers of 5-azacytidine to descript the appropriate concentration of 5-azacytidine and possibility of transformation ability of adipose tissue. Group 1 is abdominal subcutaneous adipose tissue and Group 2 is intra-abdominal adipose tissue-retroperitoneal adipose tissue and omentum. Cellular components were extracted by collagenase and $NH_4Cl$ et al, and these components were cultured by non-induction media - DMEM media containing 10% FBS and inducted by none, $3{\mu}mol/L,\;6{\mu}mol/L,\;and\;9{\mu}mol/L$ 5-azacytidine after the 1st and 2nd subculture. After 4 weeks incubation, tile cell blocks were made, immunostaining was done with the antibodies of CD34, heavy myosin chain, troponin T, and SMA. Result: Immunostaining of the transformed cells for troponin T was positive in the $6{\mu}mol/L\;&\;9{\mu}mol/L$ 5-azacytidine of Group 1 & 2, but CD34 and heavy myosin chain antibodies were negative and SMA antibody was positive in the $3{\mu}mol/L\;&\;6{\mu}mol/L$ 5-azacytidne of Group 2. Conclusion: These observations confirm that adult mesenchymal stem cells isolated from the abdominal subcutaneous adipose tissues and intra-abdominal adipose tissues can be chemically transformed into cardiomyocytes. This can potentially be a source of autologous cells for myocardial repair.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.129-134
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• 2001

Since NNK is one of the most abundant tobacco-specific alkaloids and a strong carcinogenic nitrosamine, it has been used for evaluating a potential of carcinogenicity in the animal models. The present study has attempted to examine the potential of carcinogenicity of NNK in human epithelial cells, from which the cell type the most of cancers including oral cancer and nasal cavity cancer are originated. The cellular model used for the study is a human keratinocyte cell system immortalized by Ad12-SV40 hybrid virus. The cellular system has successfully been used for the carcinogenicity studies because of its limitless life span, epithelial morphology and nontumorigenicity. When cells were treated with a variety of NNK concentrations, levels of saturation density and soft agar colony formation were increased in a dose-dependent fashion. Colonies of large cell aggregates were above 5 at the higher doses. The results indicate that exposure of human cells with NNK induced loss of contact inhibition and increases of anchorage independence and cellular adhesion, which are typical characteristics of the neoplatically transformed cells. When cells were exposed with 100uM NNK for 2hr, mRNA levels of IL-1 and PAI-2 were increased in a dose-dependent manner, but expression of TGF- 1 was not affected. While expression of growth regulatory factors were altered with a short-term exposure, there was no alteration of these factors in the NNK-transformed cells. However, mRNA levels of fibronectin were increased both in the short-term treatment and in the transformation. The results suggest that altered expression of extracellular matrix such as fibronectin following short-term exposure might be fixed in the genome and these altered properties be continuously transfered throughout the cell division. Western blot analysis showed a translocation of PKC- from cytosolic fraction to the particulate fraction, indicating a possible role of NNK in the signal transduction pathway. The present study provided an evidence that NNK in the smoking may be associated with epithelial origin cancer such as oral and nasal cavity cancers. In addition, this study suggested that altered expression of extracellular matrix and PKC may play an important role in the carcinogenic mechanism of NNK.

• Korean Journal of Veterinary Research
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• v.16 no.2
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• pp.151-158
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• 1976

The tuberculin test have been widely utilized to diagnose tuberculosis of the dairy cattle. It was reported that approximately 70% of the dairy cattle with positive tuberculin reaction in Korea had been non-pathogenic lesion. So the studies on the specific method to diagnose tuberculosis of them is really need in Korea. Therefore this study investigated upon the diagnostic method for cattle tuberculosis in the aspect of cellular-immunology. The results obtained in this investigation are summarized as follows: 1. All the tuberculin tests to the swine inoculated with BCG.(B group), Mycobacterium avium (A group) and Mycobacterium smegmatis (S group), respectively, were represented high positive reaction and were no differences in the species of inoculated bacteria. 2. In the migration inhibition test using Iymphocyte in circulating blood of the swine inoculated with three species of acid-fast bacteria respectively, the test to A group was represented slight positive for migration in the presence of $15{\mu}g/ml$-PPD and the other reaction were clear and total positive for migration inhibition in the presence of $25{\mu}g/ml$-PPD or more, and the test to B group was the same results as to A group approximately. The test to S group was represented slight positive for migration inhibition in the presence of $15{\mu}g/ml$-PPD, but the results were the same in the presence of $25{\mu}g/ml$-PPD and $35{\mu}g/ml$-PPD. These results showed that there were remarkable differences between group A, B and group S in the presence of $25{\mu}g/ml$-PPD and $35{\mu}g/ml$-PPD. 3. The transformation rates of lymphocyte in PPD treated tissue culture had no significance without any relation between PPD treatment and non-treatment but A group and B group showed significance. And A group and B group showed high significance in comparison with N group and S group in the LSD examination. 4. The infection rated in lymphocyte of BCG inoculated after 3 days tissue culturing were represented those of high infection but its cellular degeneration rates almost did not change. The infection rates in bacilli in N group and S group were low but after 3 days inoculation it shewed higher cellular degeneration.