• Applied Microscopy
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• 제2권1호
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• pp.17-31
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• 1972

우기자혹응애 (Eriophyes kuko KISHIDA)의 기생에 의하여 구기자 나무 (Lycium Chinens MILL) 잎에 형성되는 흑 (mite gall) 의 행태적 변화를 광학현미경 및 전자현미경으로 관찰한 결과는 다음과 같다. 1. 광현적 관찰 : 구기자혹응애가 구기자나무의 어린잎의 뒷면 표피세포에 침입되면 먼지 표피세포가 이상비대를 하면서 혹이 형성되기 시작한다. 혹이 성장함에 따라 붕상조직과 해면상조직의 세포도 이상비대를 하게되고, 점차적으로 각 조직의 세포는 이상비대로 인한 불규칙한 형태적 변화를 일으켜 조직의 구별이 힘들게 된다. 이상비대한 혹세포의 핵은 건전세포의 핵보다 크며, 혹이 성장함에 따라서 핵의 크기도 커진다. 2. 전현적 관찰 : 혹이 성장함에 따라 혹세포의 mitochondria, golgi-apparatus. plastid 등은 퇴 화 및 붕괴되고, 특히 큰 흑의 이상비대한 혹세포에는 성상체 (star body) 와 환상 (ring form) 의 구조등이 나타난다.

• Molecules and Cells
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• 제37권6호
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• pp.497-502
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• 2014

Microfluidics can provide unique experimental tools to visualize the development of neural structures within a microscale device, which is followed by guidance of neurite growth in the axonal isolation compartment. We utilized microfluidics technology to monitor the differentiation and migration of neural cells derived from human embryonic stem cells (hESCs). We co-cultured hESCs with PA6 stromal cells, and isolated neural rosette-like structures, which subsequently formed neurospheres in suspension culture. Tuj1-positive neural cells, but not nestin-positive neural precursor cells (NPCs), were able to enter the microfluidics grooves (microchannels), suggesting that neural cell-migratory capacity was dependent upon neuronal differentiation stage. We also showed that bundles of axons formed and extended into the microchannels. Taken together, these results demonstrated that microfluidics technology can provide useful tools to study neurite outgrowth and axon guidance of neural cells, which are derived from human embryonic stem cells.

• Restorative Dentistry and Endodontics
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• 제41권4호
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• pp.283-295
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• 2016

Objectives: In this study, we characterized human dental pulp cells (HDPCs) obtained by different culture methods to establish the most suitable methodology for dental tissue engineering and regenerative endodontic applications. Materials and Methods: HDPCs were isolated by the outgrowth method (HDPCs-OG), the enzymatic digestion method (collagenase/dispase/trypsin, HDPCs-ED), or the combination of both methods (HDPCs-Combined). The expression of mesenchymal stem cell markers (CD105, CD90, and CD73) was investigated. In vitro differentiation capacities of HDPCs into adipogenic, osteogenic, and chondrogenic lineages were compared. Differentiation markers were analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and western blotting. Results: Our data indicated that whole HDPCs-ED, HPDCs-OG, and HDPCs-Combined could be differentiated into adipogenic, chrondrogenic, and osteogenic cell types. However, we found that the methods for isolating and culturing HDPCs influence the differentiation capacities of cells. HDPCs-OG and HDPCs-ED were preferably differentiated into adipogenic and osteogenic cells, respectively. Differentiation markers shown by RT-PCR and western blotting analysis were mostly upregulated in the treated groups compared with the control groups. Conclusions: Our findings confirmed that cell populations formed by two different culture methods and the combined culture method exhibited different properties. The results of this study could provide an insight into regenerative endodontic treatment using HDPCs.

• 혜화의학회지
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• 제14권1호
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• pp.201-211
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• 2005

Cdc2 kinase is a prototypical cyclin-dependent kinase critical for G2 to M phase cell cycle transition. Yet, its function in the nervous system is largely unknown. Here, we investigated possible role of Cdc2 in axonal regeneration using sciatic nerve system in rat. Cdc2 protein levels and activity were increased in the injured sciatic nerves 3 and 7 days after crush injury and then decreased to basal level 14 days later. Administration of Cdc2 kinase inhibitor roscovitine in vivo at the time of crush injury significantly inhibited axonal regeneration when regrowing axons were analyzed using retrograde tracers. Cdc2 protein levels in cultured Schwann cells which were prepared from sciatic nerves 7 days after crush injury were much higher compared with those from uninjured sciatic nerves, suggesting that Cdc2 protein expression was primarily induced in the Schwann cells. To further investigate Cdc2 function in Schwann cell, we examined changes in cultured Schwann cell proliferation and migration in culture system. Both the number of proliferating Schwann cells and the extent of neurite outgrowth from co-cultured DRG neurons were significantly decreased by Cdc2 inhibitor roscovitine treatment in DRG culture which was prepared from animals with sciatic nerve injury for 7 days. Also, Schwann cell migration in the injured sciatic nerve explant was significantly inhibited by roscovitine treatment. Taken together, the present data suggest that Cdc2 may be involved in peripheral nerve regeneration via Schwann cell proliferation and migration.

• 대한치과교정학회지
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• 제50권3호
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• pp.206-215
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• 2020

Osteochondroma is a common benign tumor of bones, but it is rare in the mandibular condyle. With its outgrowth it manifests clinically as deviation of the mandible limitation of mouth opening, and facial asymmetry. After the tumor is diagnosed on the basis of clinical symptoms and radiographic examination including cone-beam computed tomography (CBCT) analysis, an appropriate surgery and treatment plan should be formulated. Herein, we present the case of a 44-year-old female patient who visited our dental hospital because her chin point had been deviating to the left side slowly but progressively over the last 3 years and she had difficulty masticating. Based on CBCT, she was diagnosed with skeletal Class III malocclusion accompanied by osteochondroma of the right mandibular condyle. Maxillary occlusal cant with the right side down was observed, but it was confirmed to be an extrusion of the molars associated with dental compensation. Therefore, after intrusion of the right molars with the use of temporary anchorage devices, sagittal split ramus osteotomy was used to remove the tumor and perform orthognathic surgery simultaneously. During 6 months after the surgery, continuous bone resorption and remodeling were observed in the condyle of the affected side, which led to a change in occlusion. During the postoperative orthodontic treatment, intrusive force and buccal torque were applied to the molars on the affected side, and a proper buccal overjet was created. After 18 months, CBCT revealed that the rate of bone absorption was continuously reduced, bone corticalization appeared, and good occlusion and a satisfying facial profile were achieved.

• 한국동물생명공학회지
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• 제35권1호
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• pp.86-93
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• 2020

The establishment of porcine embryonic stem cells (ESCs) from porcine somatic cell nuclear transfer (SCNT) blastocysts is influenced by in vitro culture day of porcine reconstructed embryo and feeder cell type. Therefore, the objective of the present study was to determine the optimal in vitro culture period for reconstructed porcine SCNT embryos and mouse embryonic fibroblast (MEF) feeder cell type for enhancing colony formation efficiency from the inner cell mass (ICM) of porcine SCNT blastocysts and their outgrowth. As the results, porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days showed significantly increased efficiency in the formation of colonies, compared to those for 7 days. Moreover, MEF feeder cells derived from outbred ICR mice showed numerically the highest efficiency of colony formation in blastocysts produced through in vitro culture of porcine SCNT embryos for 8 days and porcine ESCs with typical ESC morphology were maintained more successfully over Passage 2 on outbred ICR mice-derived MEF feeder cells than on MEF feeder cells derived from inbred C57BL/6 and hybrid B6CBAF1 mice. Overall, the harmonization of porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days and MEF feeder cells derived from outbred ICR mice will greatly contribute to the successful establishment of ESCs derived from porcine SCNT blastocysts.

• Reproductive and Developmental Biology
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• 제33권3호
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• pp.133-137
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• 2009

Pluripotent embryonic stem (ES) cells isolated from inner cell mass (ICM) of blastocyst-stage embryos are capable of differentiating into various cell lineages and demonstrate germ-line transmission in experimentally produced chimeras. These cells have a great potential as tools for transgenic animal production, screening of newly-developed drugs, and cell therapy. Miniature pigs, selectively bred pigs for small size, offer several advantages over large breed pigs in biomedical research including human disease model and xenotransplantation. In the present study, factors affecting primary culture of somatic cell nuclear transfer blastocysts from miniature pigs for isolation of ES cells were investigated. Formation of primary colonies occurred only on STO cells in human ES medium. In contrast, no ICM outgrowth was observed on mouse embryonic fibroblasts (MEF) in porcine ES medium. Plating intact blastocysts and isolated ICM resulted in comparable attachment on feeder layer and primary colony formation. After subculture of ES-like colonies, two putative ES cell lines were isolated. Colonies of putative ES cells morphologically resembled murine ES cells. These cells were maintained in culture up to three passages, but lost by spontaneous differentiation. The present study demonstrates factors involved in the early stage of nuclear transfer ES cell isolation in miniature pigs. However, long-term maintenance and characterization of nuclear transfer ES cells in miniature pigs are remained to be done in further studies.

• 한국약용작물학회지
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• 제23권4호
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• pp.298-304
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• 2015

Dendrobium loddigesii (DL) is a valuable and versatile herbal medicine with the anecdotal claims of anti-oxidant and anti-inflammation. In the present study, we investigated the whitening effects of DL under various conditions with B16F10 melanoma cells. The DL extract inhibited melanin contents and tyrosinase activity in a dose-dependent manner, compared with untreated group. Treatment of the DL extract effectively suppressed the ${\alpha}$-MSH-stimulated melanin formation, tyrosinase activity and dendrite outgrowth. Moreover, the ${\alpha}$-MSH-induced mRNA expressions of tyrosinase-related protein-1 (TRP-1), tyrosinase-related protein-2 (TRP-2), microphthalmia-associated transcription factor (MITF) and protein expression of tyrosinase were significantly attenuated by DL treatment. These results indicate that DL may be a great cosmeceutical ingredient for its whitening effects.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.144-153
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• 2021

Astrocytes play various important roles such as maintaining brain homeostasis, supporting neurons, and secreting inflammatory mediators to protect the brain cells. In aged subjects, astrocytes show diversely changed phenotypes and dysfunctions. But, the study of aged astrocytes or astrocytes from aged subjects is not yet sufficient to provide a comprehensive understanding of their important processes in the regulation of brain function. In this study, we induced an in vitro aged astrocyte model through late passage cultivation of rat primary cultured astrocytes. Astrocytes were cultured until passage 7 (P7) as late passage astrocytes and compared with passage 1 (P1) astrocytes as early passage astrocytes to confirm the differences in phenotypes and the effects of serial passage. In this study, we confirmed the morphological, molecular, and functional changes of late passage astrocytes showing aging phenotypes through SA-β-gal staining and measurement of nuclear size. We also observed a reduced expression of inflammatory mediators including IL-1β, IL-6, TNFα, iNOS, and COX2, as well as dysregulation of wound-healing, phagocytosis, and mitochondrial functions such as mitochondrial membrane potential and mitochondrial oxygen consumption rate. Culture-conditioned media obtained from P1 astrocytes promoted neurite outgrowth in immature primary cultures of rat cortices, which is significantly reduced when we treated the immature neurons with the culture media obtained from P7 astrocytes. These results suggest that late passage astrocytes show senescent astrocyte phenotypes with functional defects, which makes it a suitable model for the study of the role of astrocyte senescence on the modulation of normal and pathological brain aging.

• 생명과학회지
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• 제26권5호
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• pp.509-518
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• 2016

천문동(Asparagus cochinchinensis)은 북아시아 지역에서 열병, 감기, 신장질환, 유방암, 염증질환, 뇌질환 등의 치료에 오랫동안 사용되어온 약용식물(medicinal plant)이다. 비록, 천문동의 항염증(ani-inflammatory) 효능에 대한 일부 연구들이 수행되었지만, 신경세포에서 항염증작용과 신경성장인자(nerve growth factor, NGF)의 연관성에 대한 연구는 수행된바 없다. 따라서, 본 연구에서는 신경세포에서 신경성장인자의 분비와 작용기전에 대한 천문동 열수추출물(aqueous extract from A. cochinchinensis, AEAC)의 영향을 연구하였다. AEAC로 처리된 B35세포의 배양액에 NGF단백질의 농도는 대조물질(vehicle) 처리군에 비하여 유의적으로 증가하였으며, 특별한 독성은 관찰되지 않았다. 또한, NGF mRNA의 발현도 단백질의 농도변화와 유사한 양상을 나타내었다. 더불어, B35세포로부터 분비된 NGF의 생리활성을 확인하기 위해, AEAC-조정배지(conditioned medium)를 미분화된 PC12세포에 처리한 후 이들 세포의 신경염성 성장(neuritic outgrowth)을 관찰하였다. PC12세포의 수상돌기 길이(dendritic length)는 vehicle처리군에 비하여 AEAC-조정배지처리군에서 유의적으로 증가하였다. 또한, High affinity NGF 수용체의 하위신호전달에 포함된 p-TrkA와 p-ERK의 발현은 AEAC-조정배지처리군에서 높았지만, low affinity NGF 수용체의 하위신호전달에서는 낮은 수준으로 관찰되었다. 이러한 결과는 AEAC가 신경세포에서 NGF발현과 분비의 조절에 기여하기 때문에 신경퇴행성질환(neurodegenerative disease) 치료제로서 우수한 후보물질임을 제시하고 있다.