• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.399-405
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• 2010

Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in $GABA_A$ receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of $GABA_A$ receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.

• Journal of Plant Biotechnology
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• 제7권1호
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• pp.75-80
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• 2005

Eleutherococcus senticosus (also called Acanthopanax senticosus), belonging to Araliaceae family, has been used as an important medicinal woody plant. Mature seeds of Eleutherococcus senticosus have rudimentary (extremely immature) zygotic embryos and require a long-term stratification for about 18 months to induce germination. Here, through the methods of endosperm removal and other exogenous treatments, we investigated the factors for inducing rudimentary embryos by in vitro culture, Rudimentary zygotic embryos in seeds were at globular to heart-shaped stage at about $250{\mu}m$ in length just after harvest of fruits. When the seeds without testa were cultured on 1/2 MS (Murashige and Skoog 1962) medium, they did not germinate regardless of medium and sucrose concentrations but the removal of endosperm tissue markedly stimulated the growth of rudimentary zygotic embryos. The embryo reached ear-lier maturation, once when the endosperm surrounding the rudimentary embryos was removed. Rudimentary zygotic embryos developed cotyledons within 3 weeks of culture after endosperm emoval. However, post-mature zygotic embryos failed to germinate though they were morphologically normal, indicating another dormancy of embryos. $GA_3\;(2.0\;\cal{mg/L})$ and/or charcoal ($0.2\%$) treatment rapidly enhanced the germination of zygotic embryos. These results suggest that E. senticosus seeds have double dormancy; i. e. morphological rudimentary dormancy influenced by surrounding endosperm and physiological dormancy after post-maturation of zygotic embryos. Based on the above findings, we established the rapid germination of rudimentary zygotic embryos by in vitro culture of excised seeds with endosperm removal and $GA_3$ treatment.

• 한국수정란이식학회지
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• 제29권2호
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• pp.133-139
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• 2014

$K^+$ channels are involved in the regulation of a variety of physiological functions, including proliferation, apoptosis and differentiation, in mammalian cells. Our previous study demonstrated that the blockage of $K^+$ channels inhibits mouse early embryonic development. This study was designed to identify the effect of $K^+$ channels during bovine embryonic development. $K^+$ channel blockers (tetraethylammonium (TEA), $BaCl_2$, quinine, ruthenium red and fluoxetine) were added to the culture medium during in vitro fertilization (IVF) for 6 h to first identify the short-term effect of these chemicals. Among $K^+$ channel blockers, fluoxetine, which is used as a selective serotonin reuptake inhibitor, significantly increased the blastocyst formation rate by approximately 6% when compared to control. During the in vitro maturation (IVM) of immature oocytes and the in vitro culture (IVC) of embryos, the oocytes and embryos were exposed to fluoxetine for either a short-term (6 h) or a long-term (24 h) to compare the embryonic development in response to exposure time. The 6 h exposure to fluoxetine during IVM did not affect the blastocyst formation rate, but the rate of blastocyst formation was reduced after the 24 h exposure. On the other hand, embryonic development increased approximately 10% in both groups of embryos exposed to fluoxetine for 6 and 24 h during IVC. Taken together, fluoxetine treatment during IVF and IVC, but not IVM, enhances bovine embryonic development. These results suggest that fluoxetine-modulated signals in oocytes and embryos could be an important factor towards enhancing bovine embryonic development.

• Journal of Nutrition and Health
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• 제30권5호
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• pp.478-488
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• 1997

Omega-3 fatty acid, docosahexaenoic acid(DHA) is found in a high proportion in the structural lipids of cell membranes, in particular those of the central nervous system and the retina. Diet-induced changes in fatty acid composition in these tissues may affect physiochemical functions. This study was conducted to investigate whether supplements of DHA in infant formula has an effect on the composition of fatty acids in erythrocytes with regard to brain development. Experimental groups were breastmilk group(n=21), placebo formula group(n=15), and DHA supplemented formula (0.26%) group(n=16). Infants were selected by mothers who deliverecdd at Kyung Hee medical center from February to April, 1996. Infant body weight, length, and head circumference were similar among the experimental groups at 16 weeks of age. The levels of DHA in breastmilk, placebo formula, and DHA supplemented formula were 0.56, 0, and 0.26% of total fatty acids, respectively. There was a significant correlation between dietary DHA intake and erythrocyte DHA levels. The levels of arachidonic acid did not differ among the three expermental groups. The result of flash visual evoke potential(VEP) test was correlated with the erythrocyte levels and dietary DHA levels at 16 weeks of age. No other fatty acid was correlated with VEP test results. No differences were found in Bayley Mental and Psychomotor Development Index scores among the three groups at 20 weeks of age. DHA seems to be an essential nutrient for optimum growth and maturation of term infants. Relatively small amounts of dietary DHA supplementation significantly elevate DHA supplementation significantly elevate DHA content in erythrocytes, which in turn has an implication for better scores for infant's VEP test. Whether supplementation of formula-fed infants with DHA has long-term benefits remains to be elucidated.

• Clinical and Experimental Pediatrics
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• 제53권11호
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• pp.931-935
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• 2010

Juvenile idiopathic arthritis (JIA) is comprised of a heterogeneous group of several disease subtypes that are characterized by the onset of arthritis before the age of 16 years and has symptoms lasting at least 6 weeks. The previous classification of JIA included seven different categories, whereas its current classification was compiled by the International League of the Association for Rheumatology, and replaced the previous terms of "juvenile chronic arthritis" and "juvenile rheumatoid arthritis," which were used in Europe or North America, respectively, with the single nomenclature of JIA. As mentioned above, JIA is defined as arthritis of unknown etiology that manifests itself before the age of 16 years and persists for at least 6 weeks, while excluding other known conditions. The clinical symptoms of JIA can be quite variable. Several symptoms that are characteristic of arthritis are not necessarily diagnostic of JIA and may have multiple etiologies that can be differentiated with careful examination of patient history. The disease may develop over days or sometimes weeks, thereby making the diagnosis difficult at the time of presentation. To make a clinical diagnosis of JIA, the first step is to exclude arthritis with known etiologies. Of note, late treatment due to excessive delay of diagnosis can cause severe damage to joints and other organs and impair skeletal maturation. Therefore, early detection of JIA is critical to ensure prompt treatment and to prevent long-term complications including the likelihood of disability in childhood.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권6호
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• pp.565-569
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• 2005

Lichenoid dysplasia is a lesion similar to oral lichen planus with epithelial dysplasia. It can be clinically mistaken for oral lichen planus, but has histologic features of dysplasia and a true malignant predisposition. It is not a variant or transitional form of lichen planus but, instead, represents a distinct entity that has a true potential for malignant transformation. In addition to abnormal epithelial maturation and cytology, lichenoid dysplasia exhibits other histologic features that separate it from oral lichen planus. Lichenoid dysplasia and lichen planus share many clinical and microscopic features, leading to the frequent misdiagnosis of unrecognized lichenoid dysplasia as lichen planus. We experienced a case of lichenoid dysplasia in the oral mucosa. We treated this patient with surgical excision. The patient has now been followed for two months. It is important to recognize this precancerous condition and inspect the excision site and remaining oral mucosa during long-term follow-up.

• IMMUNE NETWORK
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• 제11권1호
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• pp.79-94
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• 2011

Background: Dendritic cell (DC)-based vaccines are currently being evaluated as a novel strategy for tumor vaccination and immunotherapy. However, inducing long-term regression in established tumor-implanted mice is difficult. Here, we show that deoxypohophyllotoxin (DPT) induces maturation and activation of bone marrow-derived DCs via Toll-like receptor (TLR) 4 activation of MAPK and NF-${\kappa}B$. Methods: The phenotypic and functional maturation of DPT-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. DPT-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity and for tumor regression against melanoma. Results: DPT promoted the activation of $CD8^+$ T cells and the Th1 immune response by inducing IL-12 production in DCs. In a B16F10 melanoma-implanted mouse model, we demonstrated that DPT-treated DCs (DPT-DCs) enhance immune priming and regression of an established tumor in vivo. Furthermore, migration of DPT-DCs to the draining lymph nodes was induced via CCR7 upregulation. Mice that received DPT-DCs displayed enhanced antitumor therapeutic efficacy, which was associated with increased IFN-${\gamma}$ production and induction of cytotoxic T lymphocyte activity. Conclusion: These findings strongly suggest that the adjuvant effect of DPT in DC vaccination is associated with the polarization of T effector cells toward a Th1 phenotype and provides a potential therapeutic antitumor immunity.

• 대한소아치과학회지
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• 제26권1호
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• pp.146-150
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• 1999

치아발육시기의 항암치료는 치아에 영향을 줄 수 있으며 이에 대한 예상 및 적절한 치료계획수립이 필요하다. 본 증례에서 환자의 왜소치는 항암 화학요법과 관련되어 발생한 것으로 추정되며, 이에 대한 장기적 관찰 및 치료가 필요할 것으로 사료된다.

• 한국발생생물학회지:발생과생식
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• 제10권4호
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• pp.215-225
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• 2006

사춘기 조숙증은 여아에서 8세 이전에 유방 발육이 있거나 남아에서 9세 이전에 고환이 4 mL 이상 커지는 것으로 정의되는데 최근 사춘기 발현 연령이 점차 낮아지고 있다. 사춘기를 시작하는 gonadotrophin releasing hormone(GnRH)의 활성화에는 흥분성 및 억제성 아미노산, 성장인자, 전사조절인자, 아디포카인 등 많은 인자들이 복합적으로 작용한다. 특발성 사춘기 조숙증의 원인으로서 유전인자, 영양상태(특히 체지방 증가), 환경호르몬 노출 등 여러 가지 원인이 추정되고 있다. 사춘기 조숙증은 정서적 스트레스뿐 아니라 성장판의 조기폐쇄로 인한 저신장을 초래할 수 있다. 사춘기 조숙증은 진성 성조숙증과 가성 성조숙증으로 분류할 수 있으며 gonadotrophin이 활성화되는 진성 성조숙증에서는 적절한 시기에 GnRH 길항제를 치료하였을 때 사춘기 지연 및 최종 성인 신장을 호전시키는 것으로 보고되고 있으나 그 효과 및 장기적 부작용에 대해서는 좀더 연구가 필요하리라 사료된다.

• 환경영향평가
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• 제26권1호
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• pp.1-10
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• 2017

본 연구는 제주도에 도입된 외래 포유동물인 뉴트리아의 서식현황과 생물학적 특성을 밝히기 위하여 2013년 5월부터 2016년 8월까지 수행되었다. 연구를 통해 트랩으로 5개체가 포획되었고, 사체 2개체를 수집하였다. 이중 부패가 심해 생물학적 정보가 불분명한 1개체는 분석에서 제외했다. 조사한 암컷 4개체와 수컷 2개체는 모두 백색계통이었고, 눈동자는 적색이었다. 외부형태와 두개골형질 분석, 해부학적 관찰결과들은 포획된 암컷들이 성적으로 성숙한 상태였으나 번식활동은 이루어지지 않았음을 알 수 있었다. 수컷 성체의 신체크기는 내륙의 성체와 유사하였다. 2013년 7개체 수집 이후 2014년 5월, 무인카메라에 1개체가 촬영되었으나 포획되지는 않았다. 이후 연구지역에서 지속적으로 모니터링을 실시한 결과, 서식하는 개체가 더 이상 확인되지 않아 자연사했거나 이주한 것으로 판단된다. 한정된 공간에서 토착 동물들과 유입종이 공존하는 제주지역의 특성에 맞는 뉴트리아의 관리방안을 마련하기 위해서는 제주도의 환경적 특성이 고려되어야 할 것이다. 이 연구 결과는 뉴트리아의 생물학적 특성을 이해하고, 제주도의 자연생태계 보호 프로그램을 마련하는 데 유용한 정보로 활용될 것이라 판단된다.