• 한국환경성돌연변이발암원학회지
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• 제24권4호
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• pp.180-188
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• 2004

CYP1A1 is known to be inducible by xenobiotic compouds such as polyciclic aromatic hydrocarbons(PAHs) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin(TCDD). These chemicals have been identified worldwide and can have a significant impact on the human health and well being of human and wildlife. Given these issues, the detection and quantification of these chemicals in biological, environmental and food samples is important. We investigated the effect of dietaty flavonoid, such as CYP1A1 promoter activity, 7-ethoxyresorufin-O-deethylase(EROD) activity and CYP1A1 mRNA expression induced by benzo(k)fluoranthene(B(k)F) in MCF-7 cells. Based on the three criteria of frequency of occurrence in the environment, toxicity and potential exposure to humans, B(k)F is one of the top-listed PAHs. We found that B(k)F significantly up-regulates the level of CYP1A1 promoter activity, EROD and CYP1A1 mRNA. when cells were treated with daidzein inhibited the B(k)-induced CYP1A1 prompter activity and mRNA level at high concentration. But daidzein exhibited stimulatory effects B(k)F-induced CYP1A1 promoter activity and mRNA level at low concentration. Overall, results from these studies demonstrate flavonoids might interfere the action of B(k) with AhR system to stimulate CYP1A1 gene expression.

• 말소리와 음성과학
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• 제10권4호
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• pp.91-99
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• 2018

Korean stops are currently undergoing a tonogenetic sound change, as found in the Seoul dialect in which a merged VOT of aspirated and lax stops induces F0 to be the primary cue for distinguishing the two stops and the lax stops have lower F0 than the aspirated stops. In tonal languages, low tone is produced with a breathy voice. This study investigated whether there are changes in voice quality with respect to the tonogenetic sound change of Korean stops. Two age groups speaking the Seoul dialect participated in this study: five females and six males born in the 1940s and 1950s and nine females and eight males born in the 1980s and 1990s. This study replicated previous findings of VOT and F0 and further examined H1-H2, H1-A1, and H1-A2 to see how they correlate with the sound change. In the older and younger generations, H1-H2, H1-A1, and H1-A2 were significantly lower after the tense stops than after the aspirated and lax stops, but they were not significantly different after the aspirated and lax stops. However, the younger females exhibited some different results for H1-H2 and H1-A2 than the older generation. In the younger females, the H1-H2 mean was higher after the aspirated stops than it was after the lax stops at the vowel onset, and the H1-H2 difference increased at the vowel midpoint. Although there was an inter-speaker variation in the results of H1-H2 and H1-A1, analyses of individual speakers showed that the H1-H2 and H1-A1 were higher after the lax stops than after the aspirated stops in the younger female speakers. These results indicate that lax stops tend to be breathier than aspirated stops in the younger female speakers. They also indicate that changes in voice quality are on Korean stops with tonal sound change, but are still developing.

• 생명과학회지
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• 제13권1호
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• pp.54-58
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• 2003

새로운 농약을 창출하기 위해, thiazole 유도체 등에서 살균력이 존재하는 구조를 가진 1,2-benzisothiazole-3-one-1,1-dioxide를 선도물질로 imidazolidinetrionyl 기를 가진 새로운 화합물을 합성하였다. 1-methylurea와 oxalyl chloride의 반응으로부터 4단계 반응을 거쳐 1-methyl-3-(1,1,3-trioxo-1,3-dihydro-1λ$^6$-benzo[d]isothiazol-2-ylmethyl) -imidazolidine-2,4,5-triones 5a, 1-ethyl-3- (1,1,3-trioxo-1,3-dihydro-1λ$^6$-benzo[d] isothiazo1-2-ylmethyl)-imidazolidine-2,4,5-triones 5b, 1-phenyl-3-(1,1,3- trioxo-1,3-dihydro-1λ$^6$-benzo[d]isothiazol-2-ylmethyl)-imidazolidine-2,4,5-triones 5c를 합성하였다. 합성된 5a, 5b, 5c를 식물반응, 곤충 그리고 살균제 등에 대한 생물학적 반응검색을 하였다. 생물학적 반응검색 결과(식물반응 검색은 5b, 곤충검색은 5a, 그리고 살균제 검색은 5a에서 생물활성이 조금 나타남) 썩 좋은 반응결과를 얻지 못했다. 하지만 계속해서 2,4,5-imidazolidinetrionyl기를 가진 saccharin유도체를 합성하여 새로운 농약을 창출하고자 한다.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.575-580
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• 2017

본 연구는 hnRNP A1 단백질에 포함되어 있는 RGG 상자가 이 단백질의 세포내 위치에 미치는 영향 및 이 단백질의 안정화에 미치는 영향을 분석하는 것을 목적으로 하며 2014년 10월부터 약 3년 동안 수행되었다. 이를 위해 먼저, RGG상자 내의 6개의 아르기닌을 라이신으로 돌연변이를 만든 다음 pcDNA1-HA-hnRNP A1(6R/K)를 재조합하였다. 다음, 이 플라스미드 DNA를 HeLa 세포에 형질주입하여 HA-hnRNP A1(6R/K) 단백질의 세포내 위치에 미치는 영향을 면역형광현미경법으로 분석하였다. 그 결과 hnRNP A1(6R/K) 단백질은 (wt 단백질처럼 핵에 위치하지 못하고) 핵과 세포질 모두에 퍼져 있는 것을 확인하였다. hnRNP A1(6R/K)의 안정성을 조사하기 위해서는 pcDNA1-HA-hnRNP A1(6R/K)를 HeLa 세포에 형질 주입시킨 다음 발현된 단백질을 웨스턴 블랏 실험으로 분석하였는데, 그 결과 HA-hnRNP A1(6R/K)는 (잘려서) 크기가 작아진 것을 확인할 수 있었다. 이 결과들로부터 HA-hnRNP A1(6R/K)가 핵과 세포질 모두에 퍼져 있는 것은 6R/K 돌연변이가 hnRNP A1의 핵 위치 능력에 영향을 미쳤기 때문이 아니라 6R/K 돌연변이가 일어난 부위 또는 그 부근이 절단되어 hnRNP A1의 핵 위치 신호(nuclear localization singal)인 M9 도메인이 들어있는 C-말단 부위를 잃었기 때문이라는 점을 확인 할 수 있었다. 본 연구의 결과들은 hnRNP A1에 있는 RGG 상자의 아르기닌이 hnRNP A1의 안정성에 중요한 역할을 한다는 것을 제시한다. 세균에서 발현시켜서 정제된 hnRNP A1(6R/K)의 RNA-결합 능력에 대한 영향 분석은 추후 과제로 남겨둔다.

• Journal of Positioning, Navigation, and Timing
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• 제9권4호
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• pp.337-345
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• 2020

In this paper, an efficient signal tracking method to simultaneously track both GPS L1 C/A and Galileo E1B CBOC(6,1,1/11) using a low cost GPU is proposed. In the existing method that each GNSS signal is processed within 1 ms, more than 2 ms processing time is required in GPU to process 4 ms CBOC signal. It means that real time operation is possible if only Galileo E1B CBOC signal is concerned. But when both GPS C/A and Galileo CBOC is required, it cannot process GPS C/A signal in real time. To process 1 ms GPS C/A and 4 ms Galileo CBOC signal in real time, 4 ms Galileo CBOC signal is divided into 4 by 1 ms signal block in the proposed method. Specially, a buffer that simultaneously manages 1 ms and 4 ms signals is designed. In addition, a module that accumulates the 1 ms correlation value of the Galileo CBOC by 4 ms and passes it to the PLL and DLL is implemented. The operation and performance are evaluated with real measurements in the GPU based SDR. The experimental results show that tracking of more than 16 satellites of GPS C/A and Galileo E1B is possible using the proposed method.

• 생명과학회지
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• 제16권5호
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• pp.716-722
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• 2006

Superoxide dismutase (SOD) is physiologically important in regulating cellular homeostasis and apoptotic cell death, and its mutations are the cause of familial amyotrophic lateral sclerosis (FALS). Mitochondrial serine protease HtrA2 has a pro-apoptotic function and has known to be associated with neurodegenerative disorders. To investigate the relationship between genes associated with apoptotic cell death, such as HtrA2 and SOD1, we utilized the pGEX expression system to develop a simple and rapid method for purifying wild-type and ALS-associated mutant SOD1 proteins in a suitable form for biochemical studies. We purified SOD1 and SOD1 (G93A) proteins to approximately 90% purity with relatively high yields (3 mg per liter of culture). Consistent with the result in mammalian cells, SOD1 (G93A) was more insoluble than wild-type SOD1 in E. coli, indicating that research on the aggregate formation of SOD1 may be possible using this pGEX expression system in E. coli. We investigated the HtrA2 serine protease activity on SOD1 to assess the relationship between two proteins. Not only wild-type SOD1 but also ALS-associated mutant SOD1 (G93A) were cleaved by HtrA2, resulting in the production of the 19 kDa and 21 kDa fragments that were specific for anti-SOD1 antibody. Using protein gel electrophoresis and immunoblot assay, we compared the relative molecular masses of thrombin-cleaved GST-SOD1 and HtrA2-cleaved SOD1 fragments and can predict that the HtrA2-cleavage sites within SOD1 are the peptide bonds between leucine 9-lysine 10 (L9-K10) and glutamine 23-lysine 24 (Q23-K24). Our study indicates that SOD1 is one of the substrate for HtrA2, suggesting that both HtrA2 and SOD1 may be important for modulating the HtrA2-SOD1-mediated apopotic cell death that is associated with the pathogenesis of neurodegenerative disorder.

• Toxicological Research
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• 제31권4호
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• pp.339-345
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• 2015

CYP1A1 is a phase I xenobiotic-metabolizing enzyme whose expression is mainly driven by AhR. Endosulfan is an organochlorine pesticide used agriculturally for a wide range of crops. In this study, we investigated the effect of endosulfan on CYP1A1 expression and regulation. Endosulfan significantly increased CYP1A1 enzyme activity as well as mRNA and protein levels. In addition, endosulfan markedly induced XRE transcriptional activity. CH-223191, an AhR antagonist, blocked the endosulfan-induced increase in CYP1A1 mRNA and protein expression. Moreover, endosulfan did not induce CYP1A1 gene expression in AhR-deficient mutant cells. Furthermore, endosulfan enhanced the phosphorylation of calcium calmodulin (CaM)-dependent protein kinase (CaMK) and protein kinase C (PKC). In conclusion, endosulfan-induced up-regulation of CYP1A1 is associated with AhR activation, which may be mediated by PKC-dependent pathways.

• Tuberculosis and Respiratory Diseases
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• 제70권4호
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• pp.285-292
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• 2011

After an outbreak of H1N1 influenza A virus infection in Mexico in late March 2009, the World Health Organization raised its pandemic alert level to phase 6, and to the highest level in June 2009. The pandemic H1N1/A influenza was caused by an H1N1 influenza A virus that represents a quadruple reassortment of two swine strains, one human strain, and one avian strain of influenza. After the first case report of H1N1/A infection in early May 2009, South Korea was overwhelmed by this new kind of influenza H1N1/A pandemic, which resulted in a total of 700,000 formally reported cases and 252 deaths. In this article, clinical characteristics of victims of H1N1/A influenza infection, especially those who developed pneumonia and those who were cared for in the intensive care unit, are described. In addition, guidelines for the treatment of H1N1/A influenza virus infection victims in the ICU, which was suggested by the Korean Society of Critical Care Medicine, are introduced.

• Experimental and Molecular Medicine
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• 제50권12호
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• pp.6.1-6.10
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• 2018

Bmal1 is one of the key molecules that controls the mammalian molecular clock. In humans, two isoforms of Bmal1 are generated by alternative RNA splicing. Unlike the extensively studied hBmal1b, the canonical form of Bmal1 in most species, the expression and/or function of another human-specific isoform, hBmal1a, are poorly understood. Due to the lack of the N-terminal nuclear localization signal (NLS), hBMAL1a does not enter the nucleus as hBMAL1b does. However, despite the lack of the NLS, hBMAL1a still dimerizes with either hCLOCK or hBMAL1b and thereby promotes cytoplasmic retention or protein degradation, respectively. Consequently, hBMAL1a interferes with hCLOCK:hBMAL1b-induced transcriptional activation and the circadian oscillation of Period2. Moreover, when the expression of endogenous hBmal1a is aborted by CRISPR/Cas9-mediated knockout, the rhythmic expression of hPer2 and hBmal1b is restored in cultured HeLa cells. Together, these results suggest a role for hBMAL1a as a negative regulator of the mammalian molecular clock.

• 충청수학회지
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• 제13권1호
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• pp.87-94
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• 2000

In this paper we shall de ne a concept of ${\pi}_1$-category for a map relative to a subset which is a generalization of both the category for a map and the ${\pi}_1$-category of a space, and study some properties of the ${\pi}_1$-category for a map relative to a subset.