• Molecules and Cells
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• 제27권3호
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• pp.279-282
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• 2009

"Two-cysteine" peroxiredoxins are antioxidant enzymes that exert a cytoprotective effect in many models of oxidative stress. However, under highly oxidizing conditions they can be inactivated through hyperoxidation of their peroxidatic active site cysteine residue. Sulfiredoxin can reverse this hyperoxidation, thus reactivating peroxiredoxins. Here we review recent investigations that have shed further light on sulfiredoxin's role and regulation. Studies have revealed sulfiredoxin to be a dynamically regulated gene whose transcription is induced by a variety of signals and stimuli. Sulfiredoxin expression is regulated by the transcription factor AP-1, which mediates its up-regulation by synaptic activity in neurons, resulting in protection against oxidative stress. Furthermore, sulfiredoxin has been identified as a new member of the family of genes regulated by Nuclear factor erythroid 2-related factor (Nrf2) via a conserved cis-acting antioxidant response element (ARE). As such, sulfiredoxin is likely to contribute to the net antioxidative effect of small molecule activators of Nrf2. As discussed here, the proximal AP-1 site of the sulfiredoxin promoter is embedded within the ARE, as is common with Nrf2 target genes. Other recent studies have shown that sulfiredoxin induction via Nrf2 may form an important part of the protective response to oxidative stress in the lung, preventing peroxiredoxin hyperoxidation and, in certain cases, subsequent degradation. We illustrate here that sulfiredoxin can be rapidly induced in vivo by administration of CDDO-TFEA, a synthetic triterpenoid inducer of endogenous Nrf2, which may offer a way of reversing peroxiredoxin hyperoxidation in vivo following chronic or acute oxidative stress.

• Bulletin of the Korean Chemical Society
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• 제22권10호
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• pp.1131-1135
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• 2001

• Bulletin of the Korean Chemical Society
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• 제20권8호
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• pp.925-928
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• 1999

The process of transcription is the major point at which gene expression is regulated. The jun and fos families of eukaryotic transcription factor heterodimerize to form complexes capable of binding 5'-TGAGTCA-3'DNA elements (AP-1 binding site). To search for the inhibitors of the jun-fos-DNA complex formation, several natural products extracts were screened and methanol extract of tanshen (the dried roots of Salvia miltiorrhiza Bunge) showed remarkable inhibitory activity. The active compounds of the extracts were purified using re-peated column chromatography and recrystallization. Their structures were identified as tanshinone I and tanshinone IIA. Through the electrophoresis mobility shift assay and cell cytotoxicity test, tanshinone I and tanshinone IIA were identified as inhibitors that suppress not only AP-1 function but also the cell proliferation. Tanshinone I also suppressed the jun-fos-DNA complex formation in TPA-induced NIH 3T3 cells.

• 생명과학회지
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• 제15권6호
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• pp.928-934
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• 2005

ATF2는 c-Fos와 c-Jun과 같은 전사인자이며 이들은 루신지퍼 단백질이다. 루신지퍼 단백질은 동형이합체 혹은 이형이합체를 형성하며 promoter 영역에 결합하여 전사조절에 중요한 역할을 한다. 세포의 전사인자 ATF2는 ATF/CRE site에 결합하며 특히 선택적인 interfamily 이형이량체를 형성함으로써 전사 조절에 있어서 다양한 메카니즘을 제공할 수 있다. 본 연구에서는 ATF2 cDNA를 6xHis를 가진 expression vector에 subcloning하여 E.cnli BL2l에서 발현시켰다. 6xHis tag은 nickel-chelating chromatography를 가능하게 하였다 발현된 ATF2는 In vitro binding pull-down assay에서 동형이합체를 이를 뿐만 아니라 AP-1 그룹의 인자들과 선택적인 이형이합체를 형성함을 보여 주었다. BATF와는 강하게 결합하였으며 c-Jun과도 안정된 이합체를 형성하였다. 그러나 c-Fos와는 이합체를 형성하지 않으므로서 AP-1그룹 내에서도 이합체 형성이 선택적으로 이루어짐을 알 수 있다.

• Archives of Pharmacal Research
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• 제25권3호
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• pp.375-380
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• 2002

Cytochrome P4501A2 (CYP1A2) is a member of the cytochrome P450 family of isozymes involved in the phase I drug metabolism of vertebrates. CYP1A2 is responsible for the activation of a number of aromatic amines to mutagenic and carcinogenic forms. Thus, the level of CYP1A2, which varies among different populations, may determine an individual's susceptibility to these chemicals. We have previously reported on the importance of a cis element named PRB (protected region B) in the regulation of human Cytochrome P4501A2 (CYP1A2) gene, which appeared to act as a positive regulatory element. Closer examination of the PRB sequence (-2218 to -2187 bp) revealed a putative AP-1 binding site, TGACTAA, at -2212 bp (Chung and Bresnick, 1997). To elucidate the role of AP-1 in CYP1A2 regulation, we transiently overexpressed c-Jun and c-Fos transcription factors in human hepatoma HepG2 cells, and examined their influence on the CYP1A2 promoter activity by reporter gene assays. Cotransfection of the c-Jun and the c-Fos expression vectors increased the induced transactivation by five to six fold from the CYP1A2 promoter constructs. However, deletion of the PRB element did not affect the degree of activation by the c-Jun and the c-Fos. Therefore, it is unlikely that the c-Jun and the c-Fos activate the CYP1A2 promoter through this AP-1 consensus-like sequence in the PRB region.

• Journal of Periodontal and Implant Science
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• 제49권6호
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• pp.382-396
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• 2019

Purpose: The purpose of this study was to elucidate the efficacy and safety of carbonate apatite (CO₃Ap) granules in 2-stage sinus floor augmentation through the radiographic and histomorphometric assessment of bone biopsy specimens. Methods: Two-stage sinus floor augmentation was performed on 13 patients with a total of 17 implants. Radiographic assessment using panoramic radiographs was performed immediately after augmentation and was also performed 2 additional times, at 7±2 months and 18±2 months post-augmentation, respectively. Bone biopsy specimens taken from planned implant placement sites underwent micro-computed tomography, after which histological sections were prepared. Results: Postoperative healing of the sinus floor augmentation was uneventful in all cases. The mean preoperative residual bone height was 3.5±1.3 mm, and this was increased to 13.3±1.7 mm by augmentation with the CO₃Ap granules. The mean height of the augmented site had decreased to 10.7±1.9 mm by 7±2 months after augmentation; however, implants with lengths in the range of 6.5 to 11.5 mm could still be placed. The mean height of the augmented site had decreased to 9.6±1.4 mm by 18±2 months post-augmentation. No implant failure or complications were observed. Few inflammatory cells or foreign body giant cells were observed in the bone biopsy specimens. Although there were individual differences in the amount of new bone detected, new bone was observed to be in direct contact with the CO₃Ap granules in all cases, without an intermediate layer of fibrous tissue. The amounts of bone and residual CO₃Ap were 33.8%±15.1% and 15.3%±11.9%, respectively. Conclusions: In this first demonstration, low-crystalline CO₃Ap granules showed excellent biocompatibility, and bone biopsy showed them to be replaced with bone in humans. CO₃Ap granules are a useful and safe bone substitute for two-stage sinus floor augmentation.

• 대한한방내과학회지
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• 제20권1호
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• pp.99-110
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• 1999

Effects of Chiyangtang(CYT) on H. pylori-induced increase of interleukin 8 and interleukin 1 gene expression was studied in Kato Ⅲ cell line, a human stomach epithelial cell line. Treatment of H. pylori to the cell culture signifant!y increased IL-8 and IL-1 mRNA synthesis. When CYT was added along with H. pylori, the increase of IL-8 and IL-1 mRNA synthesis was blocked. Activation of transcription factor $NF-{\kappa}B$ and AP-1 which were known to important in IL-8 and IL-1 gene expression was also studied using chloramphenicol acetyltransferase(CAT) assay. Treatment of H. pylori increased activation of $NF-{\kappa}B$ and AP-l and CYT effectively protected the activation. Electrophoretic mobility shift assay suggested that CYT effectively inhibited DNA binding of $NF-{\kappa}B$ and AP-l to their cognate site. These results suggested that CYT could prevent stomach diseases through the down regulation of IL -8 and IL-l gene expression which might be mediated by the inhibition of $NF-{\kappa}B$ and AP-1 activities and their binding to DNA.

• 한국지형학회지
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• 제17권2호
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• pp.41-52
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• 2010

양양 오산리 쌍호 일대의 신석기 유적지가 입지한 해안사구(S1)와 쌍호 가장자리 충적층(S4)에서 얻은 토양으로 화분분석을 행하고, 두 지점의 지형특성과 관련하여 고식생환경을 복원하였다. 신석기 유구 위에 퇴적된 해안사구(S1)의 저습지는 약 4,000년 BP 경부터 형성되었던 것으로 추정된다. 흑송(해송)이 전 시기동안 번성하였으며, 약 2,000년 BP를 경계로 화분대가 구분되었다. 화분대 I시기는 AP가 우점한 가운데 국화과가 우세하였고, 화분대 II는 벼과, 쑥속, 메밀 등을 중심으로 하는 NAP 우점기로서 농경 시기의 특징을 보였다. 쌍호 가장자리 충적층(S4)에서는 상부유기질층이 형성될 때, 습지 가장자리에서 번성한 오리나무속을 중심으로 하는 낙엽활엽수림과 벼과, 쑥속, 국화과, 부들속, 산형과, 여뀌속이 번성하였다. 전 시기동안 초본화분(NAP)이 목본(AP)에 비해 우점하므로, 해안사구(S1)의 화분대 II시기와 대비된다.

• KASI NEWSLETTER
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• 통권28호
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• pp.1-4
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• 2001

지역천문대 하반기 관측시간 배정/2001 하계 교사연수 실시/연구원 방문의 날 행사 실시/ 2001 전파천문학 여름학교 개최/CFHT관측제안서 모집/대한민국 과학축전 참가/광학천문학 워크샵 개최 예정/보현산천문대 주.부경 진공증착/소백산천문대 SITe 2K CCD 카메라 장착, 시험 관측에 성공/2001 한국천문올림피아드 개최 예정/제4회 동양 천문학사학회 참석/콜로키움/아시아-태평양 전파과학 컨퍼런스 (AP-RASC'01) 참석

• 한국미생물·생명공학회지
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• 제14권3호
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• pp.245-250
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• 1986

청주시 무심천의 하천수에서 항생물질에 내성을 나타내는 Gram 음성 세균을 분리하여 수질환경에서 일어나는 R 플라스미드의 전이를 연구하였다. 분리된 균주사이에서 접합에 의한 R 플라스미드의 전이는 실험실 환경에서 1.1$\times$$10^{-6}$-1.2$\times$$10^{-7}$, 하천의 수질환경에서 1.2$\times$$10^{-7}$-1.0$\times$$10^{-9}$으로 나타나, 자연의 수질환경에서도 R 플라스미드의 전이가 일어남을 확인하였다. 또 T-44 균주의 Ap$^{r}$Cm$^{r}$Tc$^{r}$ 플라스미드는 형질전환에 의하여 E. coli HB 101에 1.7$\times$$10^{-6}$의 비율로 전이되었다. 분자의 크기가 약 9.01kb로 측정된 Ap$^{r}$Cm$^{r}$Tc$^{r}$플라스미드 DNA를 제한효소로 처리한 결과 이 플라스비드에는 EcoRI과 BamHI의 절단부위가 각각 하나씩 존재하고 P-stI의 절단부위는 3개가 있었다.