• Progress in Medical Physics
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• v.15 no.4
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• pp.228-236
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• 2004

Retinal ganglion cells transmit visual scene as an action potential to visual cortex through optic nerve. Conventional recording method using single intra- or extra-cellular electrode enables us to understand the response of specific neuron on specific time. Therefore, it is not possible to determine how the nerve impulses in the population of retinal ganglion cells collectively encode the visual stimulus with conventional recording. This requires recording the simultaneous electrical signals of many neurons. Recent advances in multi-electrode recording have brought us closer to understanding how visual information is encoded by population of retinal ganglion cells. We examined how ganglion cells act together to encode a visual scene with multi-electrode array (MEA). With light stimulation (on duration: 2 sec, off duration: 5 sec) generated on a color monitor driven by custom-made software, we isolated three functional types of ganglion cell activities; ON (35.0$\pm$4.4%), OFF (31.4$\pm$1.9%), and ON/OFF cells (34.6$\pm$5.3%) (Total number of retinal pieces = 8). We observed that nearby neurons often fire action potential near synchrony (< 1 ms). And this narrow correlation is seen among cells within a cluster which is made of 6～8 cells. As there are many more synchronized firing patterns than ganglion cells, such a distributed code might allow the retina to compress a large number of distinct visual messages into a small number of ganglion cells.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.364-373
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• 2011

Human embryonic stem cells have been highlighted as a valuable cellular source in the regenerative medicine field, due to their pluripotency. However, there is the challenge of the establishment of specific functional cell type forms of undifferentiated human embryonic stem cells (hESC). To establish and purify functional cell types from hESCs, we differentiated undifferentiated hESCs into vascular lineage cells and sorted the specific cell population from the whole cell population, depending on their cell volume, and compared them with the non-sorted cell population. We observed that about 10% of the PECAM positive population existed in the VEGF induced differentiating human embryoid body (hEB), and differentiated hEBs were made into single cells for cell transplantation. After making single cells, we performed cell sorting using a fluorescence-activated cell sorter (FACs), according to their cell volume on the basis of FSC region gating, and compared their therapeutic capacity with the non-sorted cell population through cell transplantation into hindlimb ischemic disease model mice. 4 Weeks after cell transplantation, the recovery rate of blood perfusion reached 54% and 17% in the FSC regions of sorted cells- and non-sorted cells, respectively. This result suggests that derivation of a functional cell population from hESCs can be performed through cell sorting on the basis of cell volume after preliminary differentiation induction. This approach may then greatly contribute to overcoming the limitations of marker sorting.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.597-606
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• 2008

Resorption of alveolar bone in periodontitis is due to excessive differentiation and activation of osteoclasts. Bacterial antigens causing periodontitis activates CD4 T cells, which leads to expressing RANK ligand (RANKL) on CD4 T cells. RANKL binds RANK on preosteoclasts or osteoclasts, and enhances the differentiation preosteoclasts into osteoclasts and the activation of mature osteoclasts. CD137, one of TNF receptor (TNFR) family, expressed on activated T cells binds with CD137 ligand (CD137L) on antigen presenting cells. Cross-linking of CD137 by CD137L acts as T cell co-stimulatory signals and, therefore, enhances the activation of T cell. In this study, I elucidated the biological responses of CD137L on (pre)osteoclasts and RANKL on T cells in the context of in vivo interaction between T cells and osteoclasts. RAW264.7, murine monocytic cells, constitutively express CD137L. Ligation of CD137L with anti-CD137L mAb inhibited RANKL-induced osteoclast formation in a dosedependent manner. Bone marrow cells are expressed CD137L by the treatment with M-CSF. Cross-linking of CD137L abolished M-CSF/ RANKL-evoked the formation of multi-nucleated osteoclasts. Both mouse CD4 and CD8 T cells are expressed RANKL following their activation. Ligation of RANKL with OPG, the decoy receptor for RANKL, inhibited both CD4 and CD8 T cell proliferation. These effects were attributed to RANKL-induced apoptosis. These data indicate that CD137L and RANKL on osteoclasts and T cells, respectively provide them with inhibitory signal.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.313-320
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• 1989

Rhodotorula glutinis K-24 was found to produce internal, cell wall bound, and external invertase. Internal invertase was purified by column chromatographies on DEAE-Sephadex A-50, Sp-sephadex C-50, gel filtration on Sephadex G-200 and isoelectric focusing. Cell wall bound invertase was partially purified by the following procedures; column chromatography on DEAE-Sephadex A-50 and gel filtration on Sephadex G-100. Optimum pH and temperature for enzymatic activities of internal and cell wall bound invertase were pH 3.0 and 6$0^{\circ}C$, respectively. Both enzymes were inhibited by HgC1$_2$, AgNO$_3$, MnSO$_4$, and sodium dodecylsulfate. The molecular weights of internal and cell wall bound invertases were estimated to be 310,000 and 61,000, respectively. Other physicochemical properties of the both enzymes were similar.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.25-32
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• 2007

The current study was undertaken to determine the effect of conjugated linoleic acid(CLA) isomers, cis-9, cis-11(c9c11), cis-9, trans-11(c9t11), trans-9, trans-11(t9t11), trans-10, cis-12(t10c12) on differentiation of pig preadipocytes and myogenic satellite cells during culture. Cells were isolated from new born pigs. The t10c12 isomer decreased differentiation of pig preadipocytes(92%), but not that of myogenic cells. The t9t11 isomer decreased differentiation of preadipocytes(14%) and increased that of myogenic cells (26%). No other CLA isomers affected differentiation of preadipocytes or myogenic cells. The effects of CLA on proliferation of preadipocytes and myogenic cells were small, compared to the effects on differentiation. These results suggest that CLA isomers have different effects on differentiaton of pig preadipocytes and myogenic cells.

• 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.

• The Korean Journal of Zoology
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• v.34 no.3
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• pp.352-367
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• 1991

척추동물 11목 21종의 췌장에서 insulin(B)세포, glucagon(A)세포, somatostatin( D)세포 및 pancreatic polypeptide(PP)세포 등을 면역세포화학적 방법으로 동정하여 이들의 출현율, 분포양상 및 형띨 등을 계통별로 비교하였다. 포유강에서는 전형적인 췌도를 형성하였고, 조강에서는 대 ·소췌도로 구분되었다. 내분비세포의 크기는 계통간의 차이가 있어서 B세포와 PP세포는 포유강의 것이 조강의 것에 비해 윤으나, A세포와 D세포는 그 반대이었다. 세포의 모양은 B세포의 경우 두 강에서 대체로 원형 및 난원형이었고, A세포와 D세포는 원형, 난원형 및 방추형이었다. PP세포는 방추형 및 난원형이 대다수 이었으며 간혹 원형 또는 다각형 등의 모습도 나타났다. 세포들의 출현율은 두 강에서 모두 B세포가가장 많았고, A, D및 PP세포 순으로 낮아졌다. B세포는포유강이 조강보다높았고, A, D및 PP세포는조강이 포유강보다 많았다. B세포는 조강의 경우 대췌도 주변부와 소췌도 중앙부에 분포하였고, 포유강에서는 중앙부에 균등하게 분포하였다. A와 0세포는 포유강에서 주로 췌도 주면부에 분포하나, 조강에서는 췌도중앙부에 위치하였다. PP세포는 두 강에서 대부분 췌도 주변부에 위치하였다. 일반적으로 두강에서 모두 외분비 선포조직에서도 내분비세포들이 출현하였으며 일부 종에서는 췌관상피에서도 내분비세포들이 드물게 나타났다.

• Journal of Acupuncture Research
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• v.25 no.3
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• pp.53-69
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• 2008

목적 : 이 연구는 Vipera lebetina turanica의 사독약침액(蛇毒藥鍼液)(Snake venom toxin, SVT)이 인간 신경아세포종의 암세포주인 SK-N-SH 세포에서 암세포성장의 억제 및 그 기전에 대하여 살펴보고자 하였다. 방법 : SVT를 처리한 후 SK-N-SH의 성장억제를 관찰하기 위해 CCK-8 assay와 LDH assay를 시행하였고, apoptosis 평가에는 세포형태의 관찰과 DAPI, TUNEL, Annexin V-PI double staining assay 및 cell detachment assay를 시행하였다. 세포자멸사 관련 세포기전을 보기 위하여 세포주기, 세포내 칼슘량, 세포내 활성산소량 및 미토콘드리아의 세포막전위 변화를 측정하였고, DNA fragmentation assay를 시행하였으며, 세포자멸사 조절 단백인 Bax, Bcl-2, caspase-3, -9의 발현 변화 관찰에는 western blot analysis를 시행하였다. 결과 : SK-N-SH 세포에 SVT를 처리한 후, 신경아세포종 세포의 성장, Apoptosis의 유발 및 기전의 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. SVT를 처리한 SK-N-SH 세포 관찰에서 세포독성은 농도의존적으로 증가하는 경향이 있는 반면 암세포성장의 유의한 억제는 $20{\mu}g/m{\ell}$ SVT에 의해서만 나타났다. 2. 세포자멸사 평가에서 SVT를 처리한 SK-N-SH 세포는 세포자멸사의 특징적 형태를 나타내었다. TUNEL assay에서는 세포자멸사 활성세포가 미약하게 나타난 반면 cell detachment assay와 Annexin V-PI double staining에서는 각각 세포박리와 세포자멸사 활성세포의 유의한 증가를 나타내었다. 3. 세포자멸사 관련 세포기전연구에서 SVT를 처리한 SK-N-SH 세포의 세포주기, 세포 내 칼슘양 및 DNA fragmentation에는 유의한 변화가 관찰되지 않은 반면 세포내 활성산소 양은 유의한 증가를 나타내었고, 그에 따른 미토콘드리아 세포막 전위의 유의한 변동이 관찰되었다. 4. SVT를 처리한 SK-N-SH는 세포자멸사 관련 단백 발현에서 Bax에 대해 유의한 증가를 나타내지 않았으나 caspase-3 및 caspase-9의 유의한 증가와 Bcl-2의 유의한 감소를 나타내었다. 결론 : 이상의 결과는 SVT가 세포 내 활성산소를 증가시킴으로써 미토콘드리아의 세포막전위에 변화를 일으켜 인간 신경아세포종 세포주인 SK-N-SH의 세포박리와 유관한 세포자멸사를 유발함으로써 증식억제 효과가 있음을 입증한 것이다.

• Journal of Acupuncture Research
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• v.25 no.2
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• pp.41-57
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• 2008

목적 : 이 연구는 Vipera lebetina turanica의 사독약침액(蛇毒藥鍼液)(Snake venom toxin, SVT)이 인간 신경아세포종의 암세포주인 SK-N-MC 세포에서 암세포성장의 억제 및 그 기전에 대하여 살펴보고자 하였다. 방법 : SVT를 처리한 후 SK-N-MC의 성장억제를 관찰하기 위해 CCK-8 assay와 LDH assay를 시행하였고, apoptosis 평가에는 세포형태의 관찰과 DAPI, TUNEL, Annexin V-PI double staining assay 및 cell detachment assay를 시행하였다. 세포자멸사 관련 세포기전을 보기 위하여 세포주기, 세포내 칼슘량, 세포내 활성산소량 및 미토콘드리아의 세포막전위 변화를 측정하였고, DNA fragmentation assay를 시행하였으며, 세포자멸사 조절 단백인 Bax, Bcl-2, caspase-3, -9의 발현 변화 관찰에는 western blot analysis를 시행하였다. 결과 : SK-N-MC 세포에 SVT를 처리한 후, 신경아세포종 세포의 성장, Apoptosis의 유발 및 기전에 영향을 관찰하여 다음과 같은 결과를 얻었다. 1. SVT를 처리한 SK-N-MC 세포 관찰에서 $20{\mu}g/m{\ell}$ SVT 처리가 암세포성장의 유의한 억제를 나타내었다. 세포독성 관찰에서 SVT처리는 처리하지 않은 것에 비하여 증가를 나타내었다. 2. 세포자멸사 평가에서 SVT를 처리한 SK-N-MC 세포는 세포자멸사의 특징적 형태를 나타내었다. TUNEL assay에서는 세포자멸사 활성세포가 미약하게 나타난 반면 cell detachment assay와 Annexin V-PI double staining에서는 각각 세포박리와 세포자멸사 활성세포의 유의한 증가를 나타내었다. 3. 세포자멸사 관련 세포기전연구에서 SVT를 처리한 SK-N-MC 세포의 세포주기, 세포내 칼슘량 및 DNA fragmentation에는 유의한 변화가 관찰되지 않은 반면 세포내 활성산소 양은 유의한 증가를 나타내었고, 그에 따른 미토콘드리아 세포막 전위의 유의한 변동이 관찰되었다. 4. SVT를 처리한 SK-N-MC는 세포자멸사 관련 단백 발현에서 caspase-9에 대해 유의한 증가를 나타내지 않았으나 Bax 및 caspase-3의 유의한 증가와 Bcl-2의 유의한 감소를 나타내었다. 결론 : 이상의 결과는 SVT가 세포내 활성산소를 증가시키므로 미토콘드리아의 세포막전위에 변화를 일으켜 인간 신경아세포종 세포주인 SK-N-MC의 세포박리와 유관한 세포자멸사를 유발하므로 증식억제 효과가 있음을 입증한 것이다.

• Applied Microscopy
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• v.34 no.2
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• pp.131-137
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• 2004

This study is observed the skin of the parrot fish, Oplegnathus fasciatus that related study of epidermal alternation with environmental and physiological change. It composed of supporting cells, unicellular glands and accessory cells. The supporting cells are classified into superficial cell, intermediated cell and basal cell. Superficial cell of epidermal layer is squamous or cuboidal and contain nucleus of ovoid type. And its free surface has many microridge which covered with glycocalyx. Intermediated cell is ovoid and has a nucleus of round shape. Basal cell is columnar, and nucleus is situated in the upper cytoplasm. Gland cells are classified into mucous cell and club cell. By the histochemical studies of the epidermal secretions the mucous materials react on blue in ABPAS (pH 2.5). Club cell is observed numerous vacuoles and microfilaments in the cytoplasm. The cytoplasm of chloride cells are occupied with numerous mitochondria. Pigment cells are classified into two type. The one contain pigment granules of electron dense, and the other contain reflecting platelets.