• 생명과학회지
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• 제16권4호
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• pp.571-578
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• 2006

Mitochondrial serine protease로 알려진 human HtrA2 (hHtrA2)는 apoptosis 유도 과정에서 중요한 역할을 담당하고 있을 뿐만 아니라 hHtrA2가 motor neuron degeneration과 관련이 있다는 최근 연구 결과가 있으나, hHtrA2의 생리적 기능은 아직 명확하게 밝혀져 있지 않다. 이와 같이 생체내에서 필수적인 업무를 담당하는 hHtrA2의 기능을 심도 있게 연구하기 위해서는 적절한 동물모델 시스템이 필요하나 이에 대한 연구도 미흡한 실정이다. 따라서 본 연구에서는 hHtrA2의 기능 분석을 위한 기본적인 실험으로 zebrafish라는 동물모델을 선택하여 hHtrA2의 발현 시스템을 정립하였다. 먼저 zebrafish에 hHtrA2를 발현시키기 위하여 zebrafish에서 일반적으로 사용되는 발현 시스템인 pCS2+ vector에 hHtrA2와 GFP를 cloning하고 plasmid를 HEK293 cell에 transfection한 후, hHtrA2-GFP fusion 단백질의 발현을 immunoblot과 immunofluorescence staining assay로 확인한 바 약 64 kDa의 hHtrA2 단백질의 발현을 확인할 수 있었다. Zebrafish에서 hHtrA2-GFP fusion 단백질의 발현양상은 immunofluorescence microscope으로 확인하였다. hHtrA2-GFP DNA와 mRNA를 zebrafish embyro에 microinjection하여 두 가지 component의 발현을 비교 분석한 결과, DNA는 dot 형태로 mRNA는 몸 전체에 퍼져보이는 형태로 발현 양상의 차이는 있었으나 둘 다 zebrafish embryo에서 잘 발현되는 것을 알 수 있다. 다음 DNA를 주 component로 microinjection하여 zebrafish embryo에서 발현을 확인한 결과 hHtrA2는 72 hpf 까지 발현이 지속되는 것을 확인하였다. 본 연구에서 정립한 hHtrA2의 zebrafish 발현 조건은 앞으로 zebrafish에서 hHtrA2의 생리적 기능을 심도있고 정확하게 연구하는 데 있어 기본적인 자료로 활용 할 수 있을 것이다.

• 대한본초학회지
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• 제21권4호
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• pp.77-84
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• 2006

Objectives : To evaluate the neuroprotective effects of modified Bo-Yang-Hwan-O-Tang (BHT), we investigated the neuronal death protection effects to oxidative damages in N2a neuroblastoma cells. Methods : To study the cytotoxic effect of BHT on N2a neuronal cells, the cell viability was determined by MTT assay. To investigate the neuronal death protection of BHT, N2a neuronal cells were induced oxidative damages by H2O2, and assayed the cell viability and DNA fragmentation. We also investigated DPPH free radical scavenging effects of BHT by tube test. Results : In MTT assay, $500{\mu}g/ml$ of BHT was not showed cytotoxic effect on N2a neuronal cells. BHT protected N2a neuronal cells from H2O2-induced cell death in a dose-dependent manner. BHT also protected N2a neuronal cells from H2O2-induced DNA fragmentation. BHT scavenged DPPH free radicals in a dose-dependent manner. Conclusion : These data suggest that BHT may have strong anti-oxidant effects through the free radical scavenging and neuroprotective effects in neuronal cells.

• IMMUNE NETWORK
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• 제14권4호
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• pp.219-225
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• 2014

We examined the immunogenicity of H-2 class I-restricted and HLA-A2-restricted epitopes through peptide immunization of HLA-A2-transgenic mice that also express mouse H-2 class I molecules. All four of the tested epitopes restricted by H-2 class I robustly elicited T-cell responses, but four of seven epitopes restricted by HLA-A2 did not induce T-cell responses, showing that HLA-A2-restricted peptide epitopes tend to be poorly immunogenic in HLA-A2-transgenic mice. This finding was confirmed in HLA-A2-transgenic mice infected with a recombinant vaccinia virus expressing hepatitis C virus proteins. We examined the precursor frequency of epitope-specific naïve $CD8^+$ T cells in HLA-A2-transgenic and conventional C57BL/6 mice and found that the poor immunogenicity of HLA-A2-restricted peptide epitopes is related to the paucity of naïve $CD8^+$ T-cell precursors in HLA-A2-transgenic mice. These results provide direction for the improvement of mouse models to study epitope repertoires and the immunodominance of human T-cell responses.

• Journal of Ginseng Research
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• 제18권1호
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• pp.44-48
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• 1994

In adrenaline-stimulated human platelets, panaxadiol (PD) and panaxatriol (PT) from Panax ginseng C.A. Meyer did not inhibit the $Ca^{2+}$-innux, but inhibited the formation of thromboxane $A_2$ and the platelet aggregations. It seems that PD and PT block a pathyway interconvefing arachidonic acids (20:4) to thromboxane $A_2$ (TX $A_2$), because the amount of $Ca^{2+}$ which phospholipase C or phospholipase $A_2$ requires to liberate 20 : 4 from membrane phospholipids was increased by PD and PT. These results mean that PH and PT have an antiplatelet effect by Inhibiting the formation of TX $A_2$.

• Journal of applied mathematics & informatics
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• 제19권1_2호
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• pp.447-452
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• 2005

Given operators X and Y on a Hilbert space H, an interpolating operator is a bounded operator A such that AX = Y. In this article, we investigate compact interpolation problems for vectors in a tridiagonal algebra. Let L be a subspace lattice acting on a separable complex Hilbert space H and Alg L be a tridiagonal algebra. Let X = $(x_{ij})\;and\;Y\;=\;(y_{ij})$ be operators acting on H. Then the following are equivalent: (1) There exists a compact operator A = $(x_{ij})$ in AlgL such that AX = Y. (2) There is a sequence {$\alpha_n$} in $\mathbb{C}$ such that {$\alpha_n$} converges to zero and $$y_1\;_j=\alpha_1x_1\;_j+\alpha_2x_2\;_j\;y_{2k}\;_j=\alpha_{4k-1}x_{2k\;j}\;y_{2k+1\;j}=\alpha_{4k}x_{2k\;j}+\alpha_{4k+1}x_{2k+1\;j}+\alpha_{4k+2}x_{2k+2\;j\;for\;all\;k\;\epsilon\;\mathbb{N}$$.

• 약학회지
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• 제34권2호
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• pp.133-138
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• 1990

The reaction of 2-aminobenzamide with phthalic acid anhydride In dioxane produced a bicyclic product 2,8-dioxoisoindole(1,2,a) quinazoline (I) in addition to hydrolysis product 2(2-Carboxyphenyl)-1,2-2H-quinazoline-4-one (II). The yields were 64% and 30% respectively. On the other hand, the same reaction in DMF afforded compound (I) and 2(2N-dimethyl carbamyl phenyl)-1,4-2H-quinazoline-4-one (III) in 30% and 60% yield respectively. The compound III was also obtained by the reaction of compound II with dimethylamine. However the reaction of 2-aminobenzamide with neat succinic acid anhydride gave only bicyclic product 2,8-oxopyrrolidine (2,1,a)-1,4-2H-quinazoline (IV) in 93%.

• 한국결정학회지
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• 제4권1호
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• pp.6-10
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• 1993

11 β ,17 β -dihydroxy-9a-fluoro-l7a-methyl androst-4-en-3-one (Fluoxymesterone), CgoH29 FO,, orthorhombic, P2,2,2,, a=13.468(5) A, b= 19.554 (2)A, c=6.578(9)A, a=b=r=90˚, A (CuKa)=1.5406 A , Dm=1.289cm-3, Dc=1.299cm-3 and Z=4 at T=298k. The structure was solved by direct method using seminvariants of ggg Parity group and refined by the full-matrix least-square method, resulting model with reliability factor R=0.069 for 1098 unique reflection over 3σ . Ring A is an 1β-2a-half chair, 5 ring has a highly symmetrical chair conformation, C ring is in a distorted chair conformation and D ring is a 13aenveLope conformation. In the crystal structure, the molecules are packed with a hydrogen bond of 011-H23‥‥03(0.5+x, 1.5-y, 1.0-z) [1.94(9) A of H‥‥0.2.786(9)A of 0‥‥0 and 165(8) ˚ of

• 한국세라믹학회지
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• 제39권1호
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• pp.45-50
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• 2002

평균입경 25$\mu m$의 Si조대분말에 소결조제의 조성과 양을 변화시켜 질화반응 질화규소 (RBSN)세라믹스를 제조할 때 나타나는 치밀화 거동, 미세구조의 발달 및 기계적 특성에 대하여 고찰하였다. 6wt% $Y_2O_3$ + 1wt% $Al_2O_3$(6YlA)의 소결조제를 첨가한 경우에는 치밀화를 이루지 못하였으나, 6wt% $Y_2O_3+3\;wt%\;Al_2O_3+2\;wt%\;SiO_2(6Y3A2S)$와 9wt% $Y_2O_3$+1.5wt% $A1_2O_3$+ 3w% $SiO_2$(9Yl.5A3S)의 소결조제를 첨가하여 이론밀도에 가까운 치밀화를 이루었다. $1900^{\circ}C$에서 소결한 6Y3A2S시편의 경우, 960MPa의 높은 파괴강도값과 $6.5MPa.m^{1/2}$의 파괴인성값을 얻었다.

• Molecular & Cellular Toxicology
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• 제3권4호
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• pp.314-319
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• 2007

The effects of common variants of CYP1A2 gene (CYP1A2$^*$1C and CYP1A2$^*$1F) on the CYP1A2 activity and inducibility were controversial. The aim of the present study is to investigate the effects of CYP1A2$^*$1C and CYP1A2$^*$1F on the activity of CYP1A2 determined by urinary caffeine metabolite ratio in Koreans. As might be expected, there was large inter-individual variation (16-folds) of CYP1A2 activity ranged from 2.41 to 39.58. The mean CYP1A2 activity of smokers was significantly higher than that of non-smokers. The frequencies of CYP1A2$^*$1C (-3858A) and $^*$1F (-164A) alleles were 0.219 and 0.646, respectively. The effect of CYP1A2$^*$1C on the CYP1A2 activity was not significant. However, the CYP1A2 activity of subjects with AA genotype for CYP1A2$^*$1F allele was significantly lower than that of non-AA genotypes (CC, or CA). Interestingly, the significant effect of CYP1A2$^*$1F allele on CYP1A2 activity was not observed in nonsmokers. Our results suggest that CYP1A2$^*$1F allele rather than CYP1A2$^*$1C allele significantly influences on the inducibility of CYP1A2 in Koreans. Owing to small sample size of our study, further studies should be conducted to reveal the inter-ethnic difference or the gene-environmental interaction.

• Archives of Pharmacal Research
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• 제21권3호
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• pp.305-309
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• 1998

Human cytochrome P450 1A2 is one of the major cytochrome P450s in human liver. It is known to be capable of activating a number of carcinogens such as arylamines and heterocyclic amines. In order to develop the new bacterial mutagenicity test system with human P450, a full length of human P450 1A2 cDNA inserted into pCW bacterial expression vector was introduced to Escherichia coli WP2 uvrA strain which is a well-known E. coli strain for bacterial reverse mutagenicity assay. Expressed human P450 1A2 showed typical P450 hemoprotein spectra. Maximum expression was achieved at 48 hrs after incubating at $30^{\circ}C$ in terrific broth containing ampicillin, IPTG and other supplements. High level expression of P450 1A2 in E. coli WP2 uvrA membranes was determined in SDS-PAGE. The well-known mutagens 2-aminoanthracene and MElQ increased the revertant colonies of E. coli WP2 uvrA expressing human P450 1A2 without an exogenous rat hepatic post-mitochondrial supernatant (S9 fraction) in a dose-dependent manner. The results show that the functional expression of human P450 in bacterial mutagenicity tester strain will provide a useful tool for studying the mechanism of the mutagenesis and carcinogenesis of new drugs and environmental chemicals.