• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1097-1103
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• 2006

The divalent antibody-toxins are expected to have increased binding avidities to target cells because of the two cell-binding domains. However, previous studies showed that the refolding yield of divalent antibody-toxin is very low, and it is assumed that homodimer formation of antibody-toxin is strongly interfered by the repulsion between the two large toxin domains that come close to each other during dimer formation. In this study, B3 antibody was used as a model antibody, and its Fab domain was used to construct three different kinds of Fab divalent molecules, $[B3(Fab)-toxin]_{2}$. The monomer Fab-toxin molecules were made by fusing the Fab domain of monoclonal antibody B3 to PE38, a truncated mutant form of Pseudomonas exotoxin (PE), and a connecting sequence that contained spacer amino acid sequence (G4S)n (n=l, 2, 3) was inserted between Fab and PE38. The prepared divalent molecules were $[Fab-S\;1,\;2,\;3-PE38]_{2}\;(=[Fab-SKPCIST-KAS(G_{4}S)nGGPE-PE38]_{2}\;(n=1,\;2,\;3))$, and they are derivatives of previously studied $[Fab-H2cys-PE38]_{2}\;(=[Fab-SKPCIST-KASGGPE-PE38]_{2})$. In $[Fab-Sl,\;2,\;3-PE38]_{2}$, two Fab-S1, 2, 3-PE38 monomers were covalently linked by the disulfide bond bridge made from cysteine in the -SKPCIST- sequence. The insertion of spacer amino acids after the disulfide bridge resulted in a 12-18 fold higher yield of dimer formation than previously constructed $[Fab-Hlcys-PZ38]_{2}[7]$, 3-4-fold higher than $[Fab-ext-PZ38]_{2}[25]$. These two molecules have less amino acid spacer sequence between the disulfide bridge and PE38 domain. The design of $[Fab-PE38]_{2}$ in this study gave molecules with a higher refolding yield. The results of cytotoxicity assay showed a higher cytotoxic effect of these divalent molecules than that of the monovalent scFv-PE38 molecule.

• Journal of Applied Biological Chemistry
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• 제52권2호
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• pp.45-50
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• 2009

본 연구에서는 개비자나무(Cephalotaxus koreana)를 기능성 생물소재로 개발하기 위해 개비자나무 추출물(Korean Plum-yem extract, KPE)의 항균활성, 암세포 증식 억제활성 및 독성을 확인하였고, 일반성분을 조사하였다. KPE의 농도에 따른 항균활성은 그램 양성균, 그램 음성균, 효모 및 사상균에 대하여 성장 저해현상을 나타내었으며, 특히 그램 음성균인 Pseudomonas aeruginosae가 KPE에 가장 민감하게 생육 저해현상을 보였고, 마찬가지로 그램 음성균인 Salmonella thyphimurim, Escherichia coli 순이었다. 그램 양성균이 그램 음성균에 비해 KPE에 의한 생육저해효과가 작은 것으로 나타났다. 혈액암 세포주를 이용한 KPE의 암세포 증식 억제활성을 분석한 결과 80 ${\mu}g/mL$의 농도에서 현저한 암세포 저해활성을 보였다. 또한, KPE를 섭취하였을 때 유발되는 용혈율을 측정하여 KPE의 적혈구 막지질 붕괴의 유무를 조사한 결과, KPE 중 hemolysis를 일으키는 물질은 KPE의 유효성분인 HHT 외에 다른 물질이 있는 것으로 판단되었으며, Ame's test에 의한 돌연변이원성을 갖지 않음을 확인하였다. 따라서 개비자나무 추출물은 항균과 암세포에 대한 세포독성 등 기능성을 갖는 천연물 소재로서 이를 응용한 기능성 식품 개발이 가능한 것으로 판단된다.

• 대한약리학회지
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• 제27권2호
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• pp.197-205
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• 1991

Adriamycin (Doxorubicin HCl)의 혈관밖 유출에 따른 조직의 손상, 특히 피부괴양 및 괴사 기전을 규명하기 위한 연구의 일환으로 흰쥐 피부세포를 이용한 in vitro 실험에서 adriamycin에 의한 산소라디칼 생성 및 그와 관련된 세포독성 기전으로 지질과산화를 검토하였다. Adriamycin은 흰쥐 태자 피부의 배양세포에서 lactic dehydrogenase(LDH) 유리를 용량 및 시간 의존적으로 증가 시켰으며, NADPH 및 NADH 첨가 조건에서 $superoxide\;anion(O^-\;_2{\cdot})$ 생성을 현저히 증가시켰다. Adriamycin은 지질과산화 반응의 척도인 malondialdehyde(MDA) 생성을 역시 NADPH, NADH 존재하에서 용량의존적으로 증가시켰고, 산소라디칼 제거물질들인 superoxide dismutase (SOD), catalase 및 thiourea와 항산화물질인 butylated hydroxytoluene(BHT), ${\alpha}-tocopherol$은 MDA 생성증가를 현저히 억제하였다. 1, 3,-bis(2-chloroethyl)-1-nitrosourea(BCNU)를 처리하여 산화성 공격에 대한 방어기전의 하나인 glutahione 체계를 억제할 경우 adriamycin에 의한 MDA 생성은 더욱 현저히 증가하였고, 이는 역시 항산화 물질들에 의하여 억제되었다. 이상의 연구성적에서 adriamycin은 산소라디칼 생성의 증가와 그에 따른 지질과산화를 촉진하므로서 피부세포에 손상을 줄 것으로 사료되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.275-281
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• 2013

Astrocytes are reported to have critical functions in ischemic brain injury including protective effects against ischemia-induced neuronal dysfunction. Na-K ATPase maintains ionic gradients in astrocytes and is suggested as an indicator of ischemic injury in glial cells. Here, we examined the role of the Na-K ATPase in the pathologic process of ischemic injury of primary cultured astrocytes. Chemical ischemia was induced by sodium azide and glucose deprivation. Lactate dehydrogenase assays showed that the cytotoxic effect of chemical ischemia on astrocytes began to appear at 2 h of ischemia. The expression of Na-K ATPase ${\alpha}1$ subunit protein was increased at 2 h of chemical ischemia and was decreased at 6 h of ischemia, whereas the expression of ${\alpha}1$ subunit mRNA was not changed by chemical ischemia. Na-K ATPase activity was time-dependently decreased at 1, 3, and 6 h of chemical ischemia, whereas the enzyme activity was temporarily recovered to the control value at 2 h of chemical ischemia. Cytotoxicity at 2 h of chemical ischemia was significantly blocked by reoxygenation for 24 h following ischemia. Reoxygenation following chemical ischemia for 1 h significantly increased the activity of the Na-K ATPase, while reoxygenation following ischemia for 2 h slightly decreased the enzyme activity. These results suggest that the critical time for ischemia-induced cytotoxicity of astrocytes might be 2 h after the initiation of ischemic insult and that the increase in the expression and activity of the Na-K ATPase might play a protective role during ischemic injury of astrocytes.

• Applied Biological Chemistry
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• 제45권4호
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• pp.195-202
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• 2002

국내외에서 수집 재배한 29품종 유색미의 70% 에탄올 추출물로 세포독성, 변이원성, 화학적 직접변이원 mitomycin C, 4-nitroquinoline-N-oxide, 2,4,7-trinitro-9-fluorenone에 대한 항변이원성을 측정하였다. 세포 내재성 alkaline phosphatase활성을 지표로 유색미 추출물이 지시세포인 E. coli PQ 37의 성장에 미치는 영향을 조사한 결과 Jumlalocal, Jumlalocal-1을 포함하는 13종류의 유색미 추출물이 세포독성을 나타낸 반면 DK 1, SC-5, LK 1A-2-12-1-1및 wx 139-3-64-20-3-1등의 품종은 세포성장 촉진활성을 나타내었다. SOS chromotest 기법을 이용하여 유색미가 가지는 변이원성 및 항변이원성을 조사한 결과에서는 Jumlalocal-1, IR 17491-5-4-3-3 및 Jumlalocal 등의 품종이 변이원성을 유도하는 품종이었다. 화학적 직접변이원 mitomycin C, 2,4,7-trinitro-9-fluorenone 및 4-nitroquinoline-N-oxide 에 대해서 공통적으로 항변이원성 효과가 인정되는 유색미 품종은 LK1-3-6-12-1-1, Parnkhari 203, Jumlalocal, wx 139-3-64-20-3-1, Muthumanikam, HP 883-1-1-1-B-1-1, Jumla-local-1 등 7품종이었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8503-8512
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• 2016

The purpose of this study was to provide a detailed explanation of the mechanism of bisanthracycline, WP 631 in comparison to doxorubicin (DOX), a first generation anthracycline, currently the most widely used pharmaceutical in clinical oncology. Experiments were performed in SKOV-3 ovarian cancer cells which are otherwise resistant to standard drugs such as cis-platinum and adriamycin. As attention was focused on the ability of WP 631 to induce apoptosis, this was examined using a double staining method with Annexin V and propidium iodide probes, with measurement of the level of intracellular calcium ions and cytosolic cytochrome c. The western blotting technique was performed to confirm PARP cleavage. We also investigated the involvement of caspase activation and DNA degradation (comet assay and immunocytochemical detection of phosphorylated H2AX histones) in the development of apoptotic events. WP 631 demonstrated significantly higher effectiveness as a pro-apoptotic drug than DOX. This was evident in the higher levels of markers of apoptosis, such as the externalization of phosphatidylserine and the elevated level of cytochrome c. An extension of incubation time led to an increase in intracellular calcium levels after treatment with DOX. Lower changes in the calcium content were associated with the influence of WP 631. DOX led to the activation of all tested caspases, 8, 9 and 3, whereas WP 631 only induced an increase in caspase 8 activity after 24h of treatment and consequently led to the cleavage of PARP. The lack of active caspase 3 had no outcome on the single and double-stranded DNA breaks. The obtained results show that WP 631 was considerably more genotoxic towards the investigated cell line than DOX. This effect was especially visible after longer times of incubation. The above detailed studies indicate that WP 631 generates early apoptosis and cell death independent of caspase-3, detected at relatively late time points. The observed differences in the mechanisms of the action of WP631 and DOX suggest that this bisanthracycline can be an effective alternative in ovarian cancer treatment.

• Journal of Periodontal and Implant Science
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• 제33권1호
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• pp.1-11
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• 2003

Hydroxyapatite(HA) has been extensively used as bone graft materials and tooth implant surface coating materials because of its biocompatibility and osteoconductive properties. However, as HA is intrinsically poor in mechanical properties, zirconia($ZrO_2$) was incorporated with HA as reinforcing phases for improvement of mechanical properties. The purpose of this study was to investigate the biological activities of HA-coated zirconia through the cell proliferation test, measurements of alkaline phosphatase activity, and histologic examination. Four kinds of tested blocks were prepared according to the pore size (300-500${\mu}m$/500-700${\mu}m$) and the porosity (70%/90%). Cell proliferation and alkaline phosphatase activity was measured at 1, 7, 14 days. The number of cells proliferate after 7, 14 days were significantly increased in all groups when compared with that of the first day, but there was no significant difference between the 4 groups at each time period. At the 7 day, alkaline phosphatase activities of cells cultured in 4 groups were higher than that of the first day, but there was no significant difference between the 4 groups at each time period. The human gingival fibroblast and MG 63 cell was used to evaluate the cell cytotoxicity using MTT test. The materials tested in the current study turned out to be non-cytotoxic. In histologic examination(SEM), at 1 day there were many cells attached on the surfaces of all kinds of tested blocks. The number of cells were increased over time. At the 14 day, there were more cells proliferated than 1 day and some of the pores of blocks were partially filled with the proliferated cells. The in vitro response of osteoblast-like cells to the HA-coated zirconia showed comparable effect on transformation comparable to hydroxyapatite.

• KSBB Journal
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• 제20권4호
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• pp.278-284
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• 2005

식물세포의 느린 생장과 낮은 생산량의 이유로 지금까지 는 주로 미생물이나 동물세포에서 유전자 재조합 단백질을 생산하여 왔다. 그러나 저렴한 배지 가격, 동물 유래 바이러스 감염 위험성으로부터의 안정성, glycosylation 등의 post-translational modification이 가능하다는 장점들로 인하여 최근 들어 식물세포배양은 생물학적 활성을 가진 고부가가치의 단백질을 생산하는데 많이 이용되고 있다. 본 연구에서는 생장배지에 첨가했던 sucrose의 소비와 induction 배지로의 교환에서 오는 배지내의 삼투압을 조절하여 hCTLA4-Ig의 생산성을 높이고자 하였다. 다양한 삼투압 조절제 첨가 실험을 통해 sorbitol을 선별하고, 40 mM의 sorbitol 첨가에서 상대적으로 높은 생존도와 induction 후 7일째 대조구보다 1.7배 높은 생산성을 확인하였다. 또한, 저농도의 glucose 첨가를 통한 생산성 증대에 있어서는 8 mM glucose에서 induction 이후에도 높은 세포농도를 유지하면서 최대 37.3 mg/L까지 hCTLA4-Ig 생산량을 증가시켰다. 5-L bioreactor에서 회분식 배양과 induction시의 hCTLA4-Ig 생산량을 비교한 결과 induction시 배양 18일째 최고 45.3 mg/L까지 높일 수 있었으며, 회분식 배양에 비해 2.1배 증가됨을 확인하였다.

• KSBB Journal
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• 제31권4호
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• pp.277-283
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• 2016

In this system, rice cells were genetically modified to express human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) using RAmy3D promoter induced by sugar depletion. Even though the target protein fused with signal sequence peptide, plant cell wall can be a barrier against secretion of recombinant proteins. Therefore, hCTLA4Ig can be trapped inside cell wall or remained in intracellular space. In this study, to enhance the secretion of hCTLA4Ig from cytoplasm and cell walls into the medium, permeabilizing agents, such as dimethyl sulfoxide (DMSO), Triton X-100 and Tween 20, were applied in transgenic rice cell cultures. When 0.5% (v/v) of DMSO was added in sugar-free medium, intracellullar hCTLA4Ig was increased, on the other hand, the secreted extracellular hCTLA4Ig was lower than that of control. DMSO did not give permeable effects on transgenic rice cell cultures. And Triton X-100 was toxic to rice cells and also did not give enhancing permeability of cells. When 0.05% (v/v) Tween 20 was added in rice cell cultures, however, intracellular hCTLA4Ig was lower than that of control cultures. And the maximum 44.76 mg/L hCTLA4Ig was produced for 10 days after induction, which was 1.4-fold increase compared to that of control cultures. Especially, Tween 20 at 0.05% (v/v) showed the positive effect on the secretion of hCTLA4Ig though the decrease of intracellular hCTLA4Ig. Also, Tween 20 as a non-toxic surfactant did not affect the cell growth, cell viability and protease activity. In conclusion, secretion of hCTLA4Ig could be increased by enhancing permeability of cells regardless of the cell growth, cell viability and protease activity.

• 한국의학물리학회지:의학물리
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• 제20권3호
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• pp.125-131
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• 2009

본 연구는 소화기영역에서의 재협착을 방지하기 위하여 인간의 혈관 평활근 세포의 증식과 이동을 억제하며 신생내막의 형성을 억제하는 특성을 갖는 파클리탁셀(paclitaxel)을 스텐트 표면에 PVAc, PLGA, Silicone rubber 등 다양한 생체고분자로 코팅하여 paclitaxel eluting stent (PES)을 제조하고 그 특성을 분석하였다. 제조된 PES는 코팅용액의 농도가 증가할수록 그리고 코팅고분자의 분자량이 증가할수록 약물함량은 증가 되었고, bare 스텐트보다 커버드(covered) 스텐트의 표면적이 넓기 때문에 약물함량이 약 3배 정도 많음을 알 수 있었다. $^1H-NMR$ 결과에서 스텐트 표면에 파클리탁셀의 코팅과 약물의 변형이 없었음을 알 수 있었고, Silicone rubber을 제외한 다른 생체고분자는 스텐트 표면에 약물이 고르게 코팅되었음을 SEM image로부터 알 수 있었다. 그리고 in vitro에서 PES의 항암활성은 생분해성 고분자이고 분자량이 작은 PLGA 502H가 가장 높게 나타났으며, 분자량이 높을수록 낮은 항암활성을 나타냈다. 이상의 결과로부터 코팅고분자의 종류, 분자량 그리고 코팅용액의 농도를 변화시켜 약물함량을 증가시키고 약물방출을 조절할 수 있는 PES를 성공적으로 제조하였다.