• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.186-192
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• 1997

Increased activities of phase 2 enzymes including quinone reductase(QR) have been reported to be associated with protection of animals from neoplastic, mutagenic, and other toxic effects of many carcinogens. In previous study, we found that methanol extract of roasted and defatted perilla meal induced the activity of quinone reductase, an anticarcinogenic marker enzyme, in murine hepalc1c7 cells. Current study showed that unroasted perilla had a limited QR-inducing activity, suggesting that roasting cause the generation of active component(s). Thus we hypothesized that QR inducer in perilla might be covalently linked to sugar moiety and released during roasting process. Methanol extract of defatted raw perilla was subject to acid treatment in order to hydrolyze the potential sugar moiety. Prolonged hydrolysis of methanol extract of defatted raw perilla at $98{\sim}100^{\circ}C$ increased the ability to induce cytosolic QR activity of hepalclc7 cells. Furthermore roasting at 180 and $200^{\circ}C$ resulted in significant induction of QR activity. The result strongly support the idea that QR inducer(s) is present in bound form in raw perilla and released during roasting. Cellular QR activity was induced proportionately with the increase of concentration of methanol extract of roasted perilla. The induction of QR by defatted perilla was also examined in the cytosols of liver, small intestine, stomach, lung and kidney of male ICR mice. Induction patterns showed specificity with respect to target tissue and roasting of perilla. Unroasted perilla meal (defatted) significantly induced QR in liver and lung, while roasted perilla meal induced QR in liver and stomach. The observation that raw perilla showed similar QR induction patterns to roasted perilla is consistent with our proposal that QR inducer(s) is present in bound form and released by physical and chemical treatments as digestive or microbial enzymes could release the inducers from inactive glycoside forms in gastrointestinal tract of mice. In conclusion, perilla could exert protective effect against chemically induced carcinogenesis by inducing phase 2 enzymes in biological systems regardless of chemical and physical process such as roasting.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.290-303
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• 2006

Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Osteoclast precursors must be recruited into the dental follicle prior to the onset of eruption. This function of dental follicle may be regarded as the ability of bone remodeling characterized by the interaction of osteoclasts and osteoblasts. This is because tooth eruption is a localized event in which many of the genes required for eruption are expressed in the dental follicle. RANKL is a membrane-bound protein that is a member of the TNF ligand family. which is present on bone marrow stromal cells and osteoblasts, and induces osteoclast formation and activation from precursor cell. The biologic effect of RANKL is inhibited by OPG and, in bone, the relative ratio of RANKL and OPG modulates osteoclastogenesis. To evaluate the roles of RANKL and OPG in tooth eruption and the relations with the expression pattern of Runx2, in situ hybridization was performed with mandibles of mice at postnatal stage 1, 3, 5, 7, 9 and 11. mRNA of RANKL, OPG, and Runx2 are expressed in dental follicle and surrounding tissue from P1 to 11. To determine the sites of osteoclastic activity during tooth eruption, mandibles were dissected. Peak osteoclastic activity in alveolar bone along the occlusal and basal regions was observed from P5 to 9, with osteoclasts in these regions being large and strongly TRAP-positive The specific spatio-temporal expression patterns of RANKL, OPG, and Runx2 in our study suggest that tooth eruption could be progressed through the interactions of molecular signaling among dental follicle, dental organ and alveolar bone, furthermore it means that dental follicle is quite important in tooth eruption In addition, it indicates that these genes (RANKL, OPG, and Runx2) play critical roles in tooth eruption.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.651-658
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• 2004

Runx2 is a transcription factor in homologous with Drosophila runt gene and it is essential for bone formation during embryogenesis and a critical gene for osteoblast differentiation and osteoblast function. Runx2-haploinsufficency causes cleidocranial dysplasia (CCD). CCD is an autosomal-dominant inherited disorder characterized by hypoplastic clevicle and delayed ossification in fontanelles and wormian bones. Dental defects are possibly shown to CCD patients : multiple supernumerary teeth, irregular and compressed permanent tooth crowns, hypoplastic and hypomineralized defects in enamel and dentin, an excess of epithelial root remnants, the absence of cellular cementum, and abnormally shaped roots. In addition, delayed eruption of the secondary dentition is a constant finding. The aim of this study is to evaluate the role of Runx2 in the tooth development and eruption through analyzing the expression pattern of Runx2 by in situ hybridization during crown (late bell stage) and root formation of tooth, using postnatal day 1, 4, 7, 14 and 21 mice mandibular molar teeth. mRNA of Runx2-full length is expressed in dental follicle and surrounding tissue at postnatal day1 and 4. At postnatal day 7, it is expressed in ameloblasts of occlusal surface of enamel and bone area surrounding the tooth. In comparison with previous stage, at postnatal day 14, it is expressed in ameloblasts of proximal surface of enamel. At postnatal day 21 it's expression is observed only in bone area. mRNA of Runx2-typeII is not expressed. At postnatal day 1 and 7. At postnatal day 14 and 21, it's expression is observed in the bone area. In this study, we suggest that Runx2 have a relation of ameloblasts differentiation and an important role to tooth eruption made by dental follicle during intraosseous eruption stage. Also we can confirm that Runx2 has a role to bone formation.

• Journal of Chest Surgery
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• v.32 no.3
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• pp.215-223
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• 1999

Background: The replacement of the narrowed long-segment trachea with various prosthetic materials or tissue grafts remains a difficult and unsolved surgical problem. Homologous cryopreserved tracheal transplantation has been considered to treat the irreversibly-damaged organs, such as in the lung or heart transplantation and also to overcome the limited supply of donor organs. We examined the morphological changes and the immunosuppressive effects of the cryopreserved trachea after the heterotopic transplantation in the rats. Material and Method: Sixty tracheal segments harvested from 30 donor Wistar rats were heterotopically implanted into the peritoneal cavity of 20 recipient Wistar rats and 40 Sprague Dawley rats. The 60 recipient rats were divided into 6 groups(10 rats/ group). In groups I, II, and III, 30 tracheal segments were implanted immediately after the harvesting and in groups IV, V, and VI, the segments were implanted 28 days after the cryopreservation. Groups I and IV were Wistar syngeneic controls. Groups II and V were Sprague Dawley recipients receiving no immunosuppression and Groups III and VI, were Sprague Dawley recipients receiving immunosuppressive agents. At 28 days all rats were sacrificed and the tracheal segments were evaluated grossly and histologically. Result: Immunosuppression of the tracheal segments had a significant influence on the changes of the tracheal lumen and tracheal epithelial cells, irrespective of the cryopreservation of the trachea(p<0.001). In groups III and VI receiving immunosuppressive agents, the tracheal lumen was patent and the normal epithelial cells were observed, however in the other groups not receiving the immunosuppressive agents, there were almost luminal obliteration by the proliferation of the fibrous tissues and a loss of the epithelial cells, the findings were similar to those in the case of obliterative bronchiolitis after a lung and a heart-lung transplantation. Conclusion: With the appropriate immunosuppressive agents, the lumen and the respiratory epithelium of the transplanted tracheal segment were well preserved, even after the cryopreservation of the tracheal segment, which shows the possibility of the long-term preservation and homologous transplantation of the trachea. But fibroproliferative obliteration of the tracheal lumen and the loss of the normal respiratory epithelial cells, characteristic findings of obliterative bronchiolitis, were observed in the groups without the immunosuppression. This experiment using the rat trachea may be useful in studying the pathogenesis, treatment, and prevention of obliterative bronchiolitis after a lung and a heart-lung transplantation.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.247-268
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• 1996

It has been known for a long time that gonadotropins and steroid hormones play a pivotal role in a series of reproductive biological phenomena including the maturation of ovarian follicles and oocytes, ovulation and implantation, maintenance of pregnancy and fetal growth & development, parturition and mammary development and lactation. Recent investigations, however, have elucidated that in addition to these classic hormones, multiple growth factors also are involved in these phenomena. Most growth factors in reproductive organs mediate the actions of gonadotropins and steroid hormones or synergize with them in an autocrine/paracrine manner. The insulin-like growth factor(IGF) system, which is one of the most actively investigated areas lately in the reproductive organs, has been found to have important roles in a wide gamut of reproductive phenomena. In the present communication, published literature pertaining to the intrauterine IGF system will be reviewed preceded by general information of the IGF system. The IGF family comprises of IGF-I & IGF-II ligands, two types of IGF receptors and six classes of IGF-binding proteins(IGFBPs) that are known to date. IGF-I and IGF-II peptides, which are structurally homologous to proinsulin, possess the insulin-like activity including the stimulatory effect of glucose and amino acid transport. Besides, IGFs as mitogens stimulate cell division, and also play a role in cellular differentiation and functions in a variety of cell lines. IGFs are expressed mainly in the liver and messenchymal cells, and act on almost all types of tissues in an autocrine/paracrine as well as endocrine mode. There are two types of IGF receptors. Type I IGF receptors, which are tyrosine kinase receptors having high-affinity for IGF-I and IGF-II, mediate almost all the IGF actions that are described above. Type II IGF receptors or IGF-II/mannose-6-phosphate receptors have two distinct binding sites; the IGF-II binding site exhibits a high affinity only for IGF-II. The principal role of the type II IGF receptor is to destroy IGF-II by targeting the ligand to the lysosome. IGFs in biological fluids are mostly bound to IGFBP. IGFBPs, in general, are IGF storage/carrier proteins or modulators of IGF actions; however, as for distinct roles for individual IGFBPs, only limited information is available. IGFBPs inhibit IGF actions under most in vitro situations, seemingly because affinities of IGFBPs for IGFs are greater than those of IGF receptors. How IGF is released from IGFBP to reach IGF receptors is not known; however, various IGFBP protease activities that are present in blood and interstitial fluids are believed to play an important role in the process of IGF release from the IGFBP. According to latest reports, there is evidence that under certain in vitro circumstances, IGFBP-1, -3, -5 have their own biological activities independent of the IGF. This may add another dimension of complexity of the already complicated IGF system. Messenger ribonucleic acids and proteins of the IGF family members are expressed in the uterine tissue and conceptus of the primates, rodents and farm animals to play important roles in growth and development of the uterus and fetus. Expression of the uterine IGF system is regulated by gonadal hormones and local regulatory substances with temporal and spatial specificities. Locally expressed IGFs and IGFBPs act on the uterine tissue in an autocrine/paracrine manner, or are secreted into the uterine lumen to participate in conceptus growth and development. Conceptus also expresses the IGF system beginning from the peri-implantation period. When an IGF family member is expressed in the conceptus, however, is determined by the presence or absence of maternally inherited mRNAs, genetic programming of the conceptus itself and an interaction with the maternal tissue. The site of IGF action also follows temporal (physiological status) and spatial specificities. These facts that expression of the IGF system is temporally and spatially regulated support indirectly a hypothesis that IGFs play a role in conceptus growth and development. Uterine and conceptus-derived IGFs stimulate cell division and differentiation, glucose and amino acid transport, general protein synthesis and the biosynthesis of mammotropic hormones including placental lactogen and prolactin, and also play a role in steroidogenesis. The suggested role for IGFs in conceptus growth and development has been proven by the result of IGF-I, IGF-II or IGF receptor gene disruption(targeting) of murine embryos by the homologous recombination technique. Mice carrying a null mutation for IGF-I and/or IGF-II or type I IGF receptor undergo delayed prenatal and postnatal growth and development with 30-60% normal weights at birth. Moreover, mice lacking the type I IGF receptor or IGF-I plus IGF-II die soon after birth. Intrauterine IGFBPs generally are believed to sequester IGF ligands within the uterus or to play a role of negative regulators of IGF actions by inhibiting IGF binding to cognate receptors. However, when it is taken into account that IGFBP-1 is expressed and secreted in primate uteri in amounts assessedly far exceeding those of local IGFs and that IGFBP-1 is one of the major secretory proteins of the primate decidua, the possibility that this IGFBP may have its own biological activity independent of IGF cannot be excluded. Evidently, elucidating the exact role of each IGFBP is an essential step into understanding the whole IGF system. As such, further research in this area is awaited with a lot of anticipation and attention.