• Journal of Life Science
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• v.21 no.9
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• pp.1346-1353
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• 2011

Sophora tonkinensis Gapnep has been used as a traditional herbal medicine in oriental regions since ancient times. In this study, the effect and mechanism of the MeOH extract of Sophora tonkinensis Gapnep (STME) on adipocite differentiation and adipogenesis in 3T3-L1 preadipocites were investigated. Treatment with STME in the concentration range of 0-200 ${\mu}g$/ml significantly inhibited the differentiation of 3T3-L1 preadipocites in a dose-dependent manner, as determined by a decrease in intracellular lipid droplets and lipid contents measured by Oil Red O staining. In association with the inhibitory effect of lipid accumulation, the expressions of the proteins concerned with adipogenesis in 3T3-L1 preadipocites were also investigated. Treatment with STME reduced the expressions of peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ and ${\beta}$ (C/EBP${\alpha}$ and C/EBP${\beta}$) and sterol regulatory element binding protein (SREBP), which are adipocyte specific markers. In flow cytometry analysis, the inhibitory effect of differentiation was caused by G1 arrest and following mitotic clonal expansion cease. Therefore, we also investigated the alteration of G1 phase arrest-related proteins. As a result, the expression of p21 protein was significantly increased, while the expressions of Cdk2, E2F-1 and phospho-Rb were reduced in a dose-dependent manner in STME treated 3T3-L1 cells. According to these results, STME might inhibit differentiation through G1 arrest in 3T3-L1 preadipocytes adipogenesis, and further studies, which are in progress, have to be completed to identify the active compounds.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.5
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• pp.263-270
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• 2006

Purpose: Several radioisotope-labeled thymidine derivatives such as $[^{11}C]$thymidine was developed to demonstrate cell proliferation in tumor. But it is difficult to track metabolism with $[^{11}C]$thymidine due to rapid in vivo degradation and its short physical half-life. 3'-$[^{18}F]$fluoro-3'-deoxythymidine ($[^{18}F]$FLT) was reported to have the longer half life of fluorine-18 and the lack of metabolic degradation in vivo. Here, we described the synthesis of the 3'-$[^{18}F]$fluoro-3'-deoxythymidine ($[^{18}F]$FLT) and compared with $([^{18}F]FET)\;and\;([^{18}F]FDG)$ in cultured 9L cell and obtained the biodistribution and PET image in 9L tumor hearing rats. Material and Methods: For the synthesis of $[^{18}F]$FLT, 3-N-tert-butoxycarbonyl-(5'-O-(4,4'-dimet hoxytriphenylmethyl)-2'-deoxy-3'-O-(4-nitrobenzenesulfonyl)-${\beta}$-D-threopentofuranosyl)thymine was used as a FLT precursor, on which the tert-butyloxycarbonyl group was introduced to protect N3-position and nitrobenzenesulfonyl group. Radiolabeling of nosyl substitued precursor with $^{18}F$ was performed in acetonitrile at $120^{\circ}C$ and deproteced with 0.5 N HCI. The cell uptake was measured in cultured 9L glioma cell. The biodistribution was evaluated in 9L tumor bearing rats after intravenous injection at 10 min, 30 min, 60 min and 120 min and obtained PET image 60 minutes after injection. Results: The radiochemical yield was about 20-30% and radiochemical purity was more than 95% after HPLC purification. Cellular uptake of $[^{18}F]$FLT was increased as time elapsed. At 120 min post-injection, the ratios of tumor/blood, tumor/muscle and tumor/brain were $1.61{\pm}0.34,\;1.70{\pm}0.30\;and\;9.33{\pm}2.22$, respectively. The 9L tumor was well visualized at 60 min post injection in PET image. Conclusion: The uptake of $[^{18}F]$FLT in tumor was higher than in normal brain and PET image of $[^{18}F]$FLT was acceptable. These results suggest the possibility of $[^{18}F]$FLT at an imaging agent for brain tumor.

• Journal of the Korean Chemical Society
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• v.42 no.5
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• pp.506-511
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• 1998

When the spermine, which is one of the polyamines containing cation in vivo, binds to DNA, it can increase the stability of DNA. At the same time, it can cause B-form to Z-form transformations of DNA. However, because we cannot determine the binding geometry of the spermine to DNA by using spectroscopic methods, nobody can show the accurate binding mechanism of a DNA-spermine complex. Thus, we used DAPI as a spectroscopic probe of spermine, which binding geometry was well known. At the result of base selective binding geometry of spermine to synthetic DNA, the concentration of spermine gets higher, it grows the hydrophobic environment of DAPI which bound the minor groove of adenine-thymine base pair. Simultaneously, spermine seems to bridge the backbones around the minor groove of $poly[d(A-T)_2]$. So that, the intensity of fluorescence spectrum of that shows sudden increasement. In guanine-cytocine base pair, $poly[d(G-C)_2]$, we can suppose that spermine bind to the major groove of that, shoving out the DAPI which is partially intercalated between the base pocket across the major groove of it. In both cases, spermine doesn't show the base selectivity against to DNA.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.261-268
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• 2018

Differences in host ethnicities and geographical distributions may influence the genetic variation and pathogenesis of Helicobacter pylori strains, particularly with respect to those with a high risk of gastric cancer and in Asian Enigma regions. We simultaneously identified H. pylori virulence-associated genes involved in inflammation and cell damage in Thai and Korean dyspeptic patients. The virulence-associated gene cagA, cagA genotypes (East Asian and Western type cagA), vacA genotypes (s- and m-), oipA, and sabA were detected in Thai and Korean dyspeptic patients by polymerase chain reaction (PCR), real-time PCR, and DNA sequence analysis. Comparisons between the two regions showed that cagA, East Asian type cagA, and vacA s1/m1 in Korean dyspeptic patients occurred at rates of 100%, 86.67%, and 88.89%, respectively (p < 0.05). The oipA- and sabA-positive samples were significantly more predominant in the Korean population (95.56%, 91.11%) than in the Thai population (32%, 34%). DNA sequence analysis revealed differences in the patterns of cytosine-thymine dinucleotide repeats of oipA and sabA among the two populations of dyspeptic patients. Our results indicate that the H. pylori strains detected in the two regions were divergent, and strains colonizing the Korean dyspeptic patients may be more virulent than those in the Thai population. Our data may help explain H. pylori pathogenesis in Asian Enigma areas with a low gastric cancer incidence. However, other factors involving H. pylori infection in these two regions should be further analyzed.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2449-2453
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• 2007

L-[18F]FMAU ([18F]1b) was prepared from the precursor 2-O-[(trifluoromethyl)-sulfonyl]-1,3,5-tri-Obenzoyl- α-L-ribofuranose, by coupling the radioactive fluoro-sugar with the corresponding silylated thymine in 4 steps. The final products, including the α and β anomers, were purified using reverse phase HPLC with an appropriate solvent (5% CH3CN/H2O) at a flow rate of 3.0 mL/min. The total elapsed time of synthesis was about 180-200 min from EOB. The α/β anomeric ratio of the compounds was about 1:9, and the radiochemical purity of the product (β-form) was >98% with decay-corrected yields of 25-35%. All radioactive samples were confirmed using co-injection with pure non-radioactive analogues in every step. In the cellular uptake in vitro test of herpes simplex virus-thymidine kinase (HSV1-TK) gene expressed cells, the percent uptake of injected dose (%ID) of L- and D-FMAU was 37.28 and 65.86, respectively after 240 min incubation. However, the relative uptake (MCA-TK/MCA cellular uptake ratio) of L-FMAU was higher than that of D-FMAU (%ID of L-FMAU, 0.36 and D-FMAU, 0.93 after 240 min incubation in MCA cells). This means that L-FMAU will show better specific HSV1-TK gene expressed cell uptake for selective HSV1-TK gene imaging.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.233-237
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• 2006

In the present study, we compared the functional analysis of pear extracts cultured in conventional and environment-friendly conditions in primary cultured rat hepatocytes. ATP synthesis significantly increased by the treatment with environment friendly cultured pear powder but not by conventional group. In addition, cell proliferation using $[^3H]$-thymidine incorporation was also stimulated by environment-friendly cultured pear extract compared to conventional group. Moreover, the expressions of CDK-2 and CDK-4 were increased but p21WAF1/Cip1 and p27 Kip1 decreased by environment-friendly cultured pear extract but not by conventional group. In conclusion, environment-friendly cultured pear powder has stimulatory effect on cell proliferation compared to conventional group in primary cultured rat hepatocytes.

• Korean Journal of Heritage: History & Science
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• v.40
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• pp.387-411
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• 2007

The analysis of ancient DNA (aDNA) has become increasingly considerable anthropological, archaeological, biological and public interest. Although this approach is complicated by the natural damage and exogenous contamination of a DNA, archaeologists and biologists have attempted to understand issues such as human evolutionary history, migration and social organization, funeral custom and disease, and even evolutionary phylogeny of extinct animals. Polymerase chain reaction(PCR) is powerful technique that analyzes DNA sequences from a little extract of an ancient specimen. However, deamination and fragmentation are common molecular damages of aDNA and cause enzymatic inhibition in PCR for DNA amplification. Besides, the deamination of a cytosine residue yielded an uracil residue in the ancient template, and results in the misincorporation of an adenine residue in PCR. This promotes a consistent substitution (cytosine thymine, guanine adenine) to original nucleotide sequences. Contamination with exogenous DNA is a major problem in aDNA analysis, and causes oversight as erroneous conclusion. This report represents serious problems that DNA modification and contamination are the main issues in result validation of aDNA analysis. Now, we introduce several criterions suggested to authenticate reliance of aDNA analysis by many researchers in this field.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.4
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• pp.272-281
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• 2007

선박제조업을 비롯한 운송업 및 건축업 등의 다양한 분야에서 용접기술이 이용되어 옴에 따라 용접근로자들에 대한 산업보건학적 관심이 높아지고 있다. 노출정도가 다양하기는 하지만 용접흄은 6가 크롬을 비롯한 금속화합물과 유해가스, 화학물질 등을 복합적으로 포함하고 있는 스테인레스 스틸 용접흄에 대한 유전독성영향을 평가하기 위하여 흡입챔버를 이용, 실험동물인 영장류에 스테인레스 스틸 용접흄을 노출시키고 혈액 내 lymphocytes에 생성된 용접흄 노출농도 및 시간별 DNA 손상정도 및 그 회복효소를 측정함으로써, 유해성이 완전하게 확인되지 않은 용접흄에 노출되어 나타날 수 있는 암을 비롯한 심각한 건강영향을 예방하기 위한 각 지표들을 찾아 그 유용성을 비교하고자 하였다. 영장류를 노출시키기 위해 robotic arm을 장치한 영장류 흡입노출 시스템을 개발하였으며, 이 노출 시스템을 이용하여 수컷 영장류 6마리에 대해 용접흄 노출시험을 실시하였는데 실험군은 대조군 2, 저농도 ($31mg/m^3$) 노출군 2, 고농도 ($63mg/m^3$) 노출군 2마리로 구성하였고, 1일 2시간씩 일주일에 5일 동안 용접흄에 노출시켰다. 노출 농도는 지속적으로 모니터링 하였고, 노출과정 중에 영장류의 혈액을 채취하여 lymphocytes를 분리, 단세포 DNA 손상을 선별하기 위해 DNA 손상회복 효소인 E. coli formamidopyrimidine-DNA glycosylase (Fpg)와 endonuclease Ⅲ (Thymine Glycol-DNA glycosylase) 투여와 Comet asaay (single cell gel electrophoresis, 단세포겔전기영동기법)를 결합시켜 이용하는 Fpg/Endo III FLARE 분석법을 사용하였다. Fpg enzyme에 의한 olive tail moment값의 변화는 16주 노출군부터 노출부검(34주)군 까지 노출농도가 높아짐에 따른 olive tail moment 기하평균 값의 양 반응관계를 보기는 어렵지만, 고농도군의 경우 27주 노출군에서 가장 높은 olive tail moment 값을 보이고 이후 차츰 감소하였다. 한편 16주에서 22주까지의 노출기간에서는 대조군에 비해 노출군에서 DNA손상정도(olive tail moment값)는 모두 유의하게 높았으나, 6, 12, 18, 25, 31, 33, 35주간 노출하였을 때는 다른 결과를 보였다. 각 실험군의 Fpg enzyme에 의한 tail length값의 분포를 살펴볼 때, 저농도군 및 고농도군에서 27주간 노출하였을 때 가장 높은 tail length 값을 보이고 이후 차츰 감소하는 경향을 보였다. 또한 16, 22주간 노출하였을 때 대조군에 비해 노출군에서 tail length 값이 유의하게 높았으나, 20주간에서만 양 반응관계가 관찰되었고, 다른 주간에서는 양 반응 및 기간 반응관계를 나타내지는 않았다. Endo III enzyme에 의한 olive tail moment값의 변화는 기간별 노출군에서 대조군에 비해 높은 DNA손상정도(olive tail moment값)를 나타내는 결과들이 있었지만, 10, 12, 16, 22, 25, 31주간 노출하였을 때 등 상당수 노출기간에서 반응관계를 나타내지는 않았다. 각 실험군의 Endo III enzyme에 의한 tail length값의 분포를 살펴볼 때, 18, 20, 27, 33주간 노출하였을 때 대조군에 비해 노출군에서 tail length 값이 조금 높았지만, 양 반응 및 기간 반응관계를 보이지 않았고 수치의 크기가 불규칙하게 변화하였다. 즉, DNA에 있어 산화된 pyrimidine을 형성하여 손상된 부위의 염기를 제거함으로써 AP site (abasic site)를 만들고 이들이 Comet assay를 통해 break로 전환된 것을 포함한 DNA손상을 측정하기 위하여 endonuclease III (Endo III)를 첨가시킨 Endo III FLARE 분석법을 실시한 결과, 본 연구에서 나타난 결과는 용접흄 노출 영장류에서 Olive tail moment 및 tail length 공히 노출량 및 노출기간 반응관계를 볼 수 없었다. Endo III FLARE 분석법을 통한 산화적 DNA 손상지표는 영장류에 적용하기에는 적응반응현상으로 대조군과 유의한 차이도 관찰할 수 없었고 더욱이 역으로 대조군에서의 자연발생적 수치가 더 높아질 수 있어 용접흄 노출 영장류의 모니터링 지표로 사용하기에는 제한점이 있었다.