• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.633-640
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• 2004

This study was performed to investigate the cytotoxic effect of the water-extract from Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea in HCT-15 human colon carcinoma, AGS human gastric carcinoma and NIH3T3 mouse normal fibroblast cells using viable cell count and MTT assay. The water-extract from Chaga mushroom compositions induced inhibitory effects on proliferation of HCT-15 and AGS cells in the MTT assay and viable cell count. However, mouse normal NIH3T3 cells were exhibited 80% survival under the same condition. Chaga mushroom compositions showed highly antiproliferative effect in human cancer cell line HCT-15 and AGS, but not in mouse normal cell line NIH3T3. These results suggest that Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea are the candidate for chemoprevention in colon and gastric cancer.

• Journal of radiological science and technology
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• v.25 no.2
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• pp.77-82
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• 2002

It is well known that X-irradiation affects on maturing process of differentiated chondrocytes. Nevertheless, It has been remained elusively whether X-irradiation affects the process of differentiation of mesenchymal cells which differentiate into chondrocyte, fibroblast, or muscle cells. In this study, we examined the effect of X-irradiation (with 1 to 10 Gy) on chondrogenesis using the mesenchymal cells of chick limb bud. Our results show that X-irradiation dose-dependently inhibited chondrogenesis. This result suggests that immature chondroblast-like mesenchymal cells are sensitive to X-irradiation. Moreover, X-irradiation affects not only maturing process of chondrocytes, but also inhibits the chondrogenesis. Taken together, we demonstrate that the whole process of differentiation of mature chondrocytes from mesenchymal cells is affected by X-irradiation and undifferentiated cells were more affected by X-irradiation than mature cells.

• Applied Microscopy
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• v.17 no.2
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• pp.1-22
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• 1987

Pemphigus vulgar교의 본태(本態)를 알아보기 위한 일환으로 본질병(本疾病)의 병변조직(病變組織)을 전자현미경적(電子顯微鏡的)으로 관찰(觀察)하고 본질병(本疾病)에 관여(關與)하는 세포(細胞)들에 대(對)해 면역전자현미경적(免疫電子顯微鏡的)으로 추구(追究)하였던 바, 그 결과(結果)를 보고(報告)하는 바이다. 견(犬)의 pemphigus vulgaris의 구강(口腔) 및 식도(食道)의 점막층(粘膜層)을 전자현미경적(電子顯微鏡的)으로 관찰(觀察)하였던 바 acantholysis를 일으켜도 desmosome과 기저막(基底膜)은 큰 변화(變化)가 없었으며 세포간(細胞間)은 세포간물질(細胞間物質)의 집적(集積)에 의(依)해 확장(擴張)되고 이들 세포간강물질(細胞間腔物質)은 집괴(集塊) 또는 무구조(無構造)한 물질(物質)로 나타났다. 그리고 기저세포(基底細胞)는 기저막(基底膜)에 단단히 부착(附着)되어 있었고 dendritic cell이 기저세포층(基底細胞層)위로 분포(分布)되어 있었으며, 이들 dendritic cell 중(中)에서는 가끔 여러 형태(形態)의 퇴행성변화(退行性變化)를 볼 수 있었다. Mouse 피부유리상피세포(皮膚遊離上皮細胞)에 있어서 immunogold-labeling 방법(方法)에 의해 dendritic cell을 동정(同定)하는 데에는 post-fixation, pre-embedding immunogold-labeling technique가 좋았으며 15nm와 40nm 크기의 colloid-fold 입자(粒子)로 Langerhans cell과 Thy-1양성(陽性) dendritic cell이 표식(標識)될 수 있었다. 이들 세포(細胞)들은 세포막항원(細胞膜抗元)에 따라 monoclonal antibody의 반응(反應)에 이어 치밀한 colloid-gold 입자(粒子)가 세포막표면(細胞膜表面)을 따라 일정(一定)하게 표식(標識)되었다. 또한 이들 상피세포(上皮細胞)들을 투과전자현미경적(透過電子顯微鏡的)으로 관찰(觀察)하였을 때 초미세구조(超微細構造)가 잘 보존(保存)되었으나 Langer-hans cell내(內)의 Birbeck granule은 유리전(遊離前) 피부상피조직내(皮膚上皮組織內)의 Langerhans cell내(內)의 Birbeck granule에 비(比)해 수적(數的)으로 현저히 감소(減少)되어 있었다. 그러나 Thy-1 양성(陽性) dendritic cell에서 볼 수 있는 dense-core 과립(顆粒)은 별변화(別變化)없이 쉽게 관찰(觀察)될 수 있었다. 조직배양(組織培養)을 한 견(犬)의 keratinocyte에 대(對)해 사람 pemphigus vulgaris의 항체(抗體)로 반응(反應)시킨 후 protein-A gold(15 nm)로 표식(標識)시킨 바 제일 바깥 상층(上層)의 keratinocyte에 있어서 세포막표면(細胞膜表面)을 따라 표식(標識)되어 세포막항원(細胞膜抗元)을 나타내었으며, 이와 같은 소견(所見)으로 미루어 정상피부(正常皮膚) 중층편평상피세포(重層扁平上皮細胞)에서도 동일(同一)한 소견(所見)을 관찰(觀察)할 수 있다고 본다.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.40-45
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• 2006

The baculovirus-insect Drosophila melanogaster S2 cell system combines advantages of conventional baculovirus system and non-lytic S2 cell system because baculoviruses can infect non-permissive cells such as mammalian and Drosophila S2 cells but cannot replicate themselves inside the cells. In the present work, we investigated effects of infection conditions on production of green fluorescent protein (GFP) as a target protein using this baculovirus-S2 cell system. Even though higher MOI and longer baculovirus contact time showed better GFP expression yield during the shorter period, overall protein yield could be lower during the longer period due to the relatively higher cell detachment and lysis (lower cell viability). In addition, maintaining high MOI will be not practical for large-scale cell culture. Therefore, instead of maintaining high MOI, we found that high initial cell number and concentrated (10X) baculovirus volume can confer comparable protein expression even under the moderate MOI condition. Also, we found that the post-infection time that is connected to state of cells after infection was an important factor for production yield.

• Journal of Life Science
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• v.25 no.8
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• pp.953-959
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• 2015

Optogenetics is the combination of optical and molecular strategies to control designated molecular and cellular activities in living tissues and cells using genetically encoded light-sensitive proteins. It involves the use of light to rapidly gate the membrane channels that allows for ion movement. Optogenetics began with the placing of light-sensitive proteins from green algae inside specific types of brain cells. The cells can then be turned on or off with pulses of blue and yellow light. Using the naturally occurring algal protein Channelrhodopsin-2 (ChR2), a rapidly gated light-sensitive cation channel, the number and frequency of action potentials can be controlled. The ChR2 provides a way to manipulate a single type of neuron while affecting no others, an unprecedented specificity. This technology allows the use of light to alter neural processing at the level of single spikes and synaptic events, yielding a widely applicable tool for neuroscientists and biomedical engineers. An improbable combination of green algae, lasers, gene therapy and fiber optics made it possible to map neural circuits deep inside the brain with a precision that has never been possible before. This will help identify the causes of disorders like depression, anxiety, schizophrenia, addiction, sleep disorder, and autism. Optogenetics could improve upon existing implanted devices that are used to treat Parkinson’s disease, obsessive-compulsive disorder and other ailments with pulses of electricity. An optogenetics device could hit more specific subsets of brain cells than those devices can. Applications of optogenetic tools in nonneuronal cells are on the rise.

• Journal of the Korean Society of Visualization
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• v.5 no.1
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• pp.9-11
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• 2007

We introduce an in vivo imaging flow cytometer, which provides fluorescence images simultaneously with quantitative information on the cell population of interest in a live animal. As fluorescent cells pass through the slit of light focused across a blood vessel, the excited fluorescence is confocally detected. This cell signal triggers a strobe beam and a high sensitivity CCD camera that captures a snap-shot image of the cell as it moves down-stream from the slit. We demonstrate that the majority of signal peaks detected in the in vivo flow cytometer arise from individual cells. The instrument's capability to image circulating T cells and measure their speed in the blood vessel in real time in vivo is demonstrated. The cell signal irradiance variation, clustering percentage, and potential applications in biology and medicine are discussed.

• The Korean Journal of Zoology
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• v.38 no.2
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• pp.145-152
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• 1995

노랑초파리의 난실에서의 단백질 합성을 난자형성과정의 단계별로 자기방사법을 이용하여 관찰하였다 단백질은 영양세포에서 난자형성 초기에 미약한 정도로 함성되는 것으로 나타나지만, 가장 활발하게 합성되는 세포는 여포세포이다. 난모세포와 영양세포에서는 단백질이 거의 합성되지 않고 있다. 여포세포에서 합성된 단백질은 Stage 10 이후의 단계에서만 난모세포로 이동하는 것으로 관찰되었다 난모세포에 괸만하게 분포된 은입자는 난자 형성을 위한 다양한 목적을 위해 여포세포로 부터 이입된 단백질로 짐작된다. 특히 난황립의 형성에 여포세포의 단백질이 최소한도 부분적으로 관여한다는 사실을 알 수 있었다.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.388-394
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• 1995

We investigated ultrastuctural change of small intestinal mucosal epithelial cell, columnar cell and mucous cell, of hibernating ground squirrel during activating and hibernating stages. In active columnar cells, many mitochondria and rough endoplasmic reticulum were observed. In hibernating columnar cells, more free nhosome than rough endoplasmic reticulum were observed. In active mucous cells, large and many mucosal granules, mitochondria and rough endoplasmic reticulum were observed. Mucosal granules have been secreted excellently. In hibernating mucous cells, small and little mucosal granules and many free ribosome were observed.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.17-23
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• 1987

New born rat heart cells were dissociated using trypsin and/or collegenase to elucidate the dissociation efficiency of these two enzymes. And the effect of dimethyl sulfoxide during and immediately after cell dissociation was also investigated to clarify the so-called protective activity of dimethyl sulfoxide on cell performance. The results can be summarized as follows. 1. Cold trypsin 18 hours pretreatment followed by warm collagenase treatment resulted best cell viability and cell yield. 2. Single, warm trypsin treatment gave the poorest result. 3. Dimethyl sulfoxide did not seem to play any protective role during or immediately after rat heart cell dissociation. It had very damaging effect on rat heart cells.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.169-173
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• 1995

Border cells are differentiated cells which originate from meristematic cells in The root cap. Experimentally border cells can be released from the root cap by a physical treatment, for example dipping the root tip in the waters After 20-25 hours of release, the new border cell layer forms in the root cap. During the border cell differentiation, new gene expressions were observed in the root cap of pea which was determined by mRNA differential display These new gene expressions may be involved in the border cell differentiation Border cells had unique gene expressions which were determined by mRNA differential display, This suggests that border cells are differentiated cells which are different from the other tissues (ie., leaves, stems, roots or root caps).