• 생명과학회지
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• 제18권1호
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• pp.114-119
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• 2008

Wee1 인산화효소는 세포주기 조절의 핵심 단백질인 cdc2/cyclinB 복합체를 인산화하여 활성을 억제, 조절하는 주요한 효소이다. 지금까지 포유동물에서는 Wee1A, Wee1B 그리고 Myt1의 세 가지 효소가 발견되었다. Wee1 인산화효소의 조절기작을 연구하기 위하여 생쥐의 Wee1A와 Wee1B를 발톱개구리의 난자에 주사한 후 단백질의 변형을 관찰하였다. 이 세포주기 과정에서 두 효소는 모두 인산화 되었으며, Wee1A단백질은 분해되는 것을 관찰 할 수 있었다. 또한 세포외 인산화 방법을 통하여 Wee1A가 PKA와 Akt에 의해 인산화됨을 확인하였다. 이러한 Wee1 인산화효소의 인산화와 단백질 안정성에 영향을 미치는 단백질 내의 부위를 살펴보고자, Wee1A와 Wee1B의 아미노 도메인과 카르복실 도메인을 서로 치환한 단백질을 제조하여 개구리 난자에 주사하고 인산화 정도와 단백질의 안정성을 조사하였을 때, Wee1A의 아미노 도메인이 단백질의 인산화와 안정화에 중요한 영향을 미친다는 것을 규명하였다. 그리고 Wee1B의 아미노 도메인과 Wee1A의 카르복실 도메인은 효소의 활성을 조절하는 역할을 한다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6605-6611
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• 2013

Background: WEE1 is a G2/M checkpoint regulator protein. Various studies have indicated that WEE1 could be a good target for cancer therapy. The main aim of this study was to asssess the tumor suppressive potential of WEE1 silencing in two different breast cancer cell lines, MCF7 which carries the wild-type p53 and MDA-MB468 which contains a mutant type. Materials and Methods: After WEE1 knockdown with specific shRNAs downstream effects on cell viability and cell cycle progression were determined using MTT and flow cytometry analyses, respectively. Real-time PCR and Western blotting were conducted to assess the effect of WEE1 inhibition on the expression of apoptotic (p53) and anti-apoptotic (Bcl2) factors and also a growth marker (VEGF). Results: The results showed that WEE1 inhibition could cause a significant decrease in the viability of both MCF7 and MDA-MB-468 breast cancer cell lines by more than 50%. Interestingly, DNA content assays showed a significant increase in apoptotic cells following WEE1 silencing. WEE1 inhibition also induced upregulation of the apoptotic marker, p53, in breast cancer cells. A significant decrease in the expression of VEGF and Bcl-2 was observed following WEE1 inhibition in both cell lines. Conclusions: In concordance with previous studies, our data showed that WEE1 inhibition could induce G2 arrest abrogation and consequent cell death in breast cancer cells. Moreover, in this study, the observed interactions between the pro- and anti-apoptotic proteins and decrease in the angiogenesis marker expression confirm the susceptibility to apoptosis and validate the tumor suppressive effect of WEE1 inhibition in breast cancer cells. Interestingly, the levels of the sensitivity to WEE1 silencing in breast cancer cells, MCF7 and MDA-MB468, seem to be in concordance with the level of p53 expression.

• 한국발생생물학회지:발생과생식
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• 제15권1호
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• pp.1-7
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• 2011

It is suggested that FGF/Ras/MEK/Erk signaling plays crucial roles in specification and cell division of the mesodermal precursor cells in ascidian embryos. To investigate how the number of cell division in tissue precursor cells is determined, we have characterized Wee1 homolog, Hr-Wee1 of the ascidian Halocynthia roretzi. We found that the Hr-Wee1 mRNA is expressed both maternally and zygotically. Maternal transcript is localized to the cytoplasm in the animal cells, while zygotic expression is seen in cells of the endoderm lineage from 32-cell to 110-cell stages. Zygotic in situ signal is detected in the A-line neural plate cells of neurulae, and in epidermal cells of the head region of tailbud embryos. Embryos treated with MEK signaling inhibitor showed a similar pattern to normal embryos in expression of Hr-Wee1. Therefore, it is likely that MEK signaling does not affect the maternal and zygotic expression of Hr-Wee1.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1890-1894
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• 2008

Apoemulsan is a biopolymer with potent emulsification activity, produced by Acinetobacter venetian us RAG-1 (RAG-1). The wee gene cluster is responsible for apoemulsan biosynthesis. The analysis of (i) a putative polysaccharide copolymerase mutant (${\Delta}wzc$), (ii) a putative polymerase mutant (${\Delta}wzy$), and (iii) an apoemulsan-deficient variant (${\Delta}2$) indicated that the wee gene cluster controls the synthesis of two polysaccharides: high molecular weight (HMW) and low molecular weight (LMW). LMW polysaccharide of wee origin was present in LPS isolated from RAG-1 cells, suggesting a link to the Lipid A-core of LPS molecules. SDS-PAGE analysis indicated that apoemulsan is copurified with LPS polysaccharide, with implications in the emulsification activity of RAG-1 polymer.

• Journal of Information Science Theory and Practice
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• 제1권1호
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• pp.42-53
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• 2013

Timely access to quality healthcare information during an outbreak plays an important role in curtailing its spread. The aim of this study was to investigate the information needs and seeking behavior of the general public in Singapore during the H1N1 pandemic. A pre-tested questionnaire was used for data collection. The convenience snowball sampling method was used and 260 working adults and tertiary-level students participated in this study. The most crucial information needs of a majority of the participants were: symptoms of H1N1, causes of the infection, preventive measures, and possible treatments. Data analysis also revealed that mass media such as television, newspapers, and radio were most frequently used for seeking the needed information. The use of human information sources was also quite high while only a small number of the respondents accessed online news and healthcare websites. About three-quarters of the participants indicated that the gathered information helped them to stay vigilant and take necessary precautionary measures. A major problem identified by the participants in using H1N1 information was the lack of understanding of certain terms used in public communications. This paper suggests certain measures for strengthening health information communication during future outbreaks.

• 대한임상검사과학회지
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• 제38권1호
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• pp.72-81
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• 2006

Wee1 is a kinase regulator of the M-phase promoting factor (MPF; a complex of cdc2 and cyclin B1). The present study was undertaken to determine the role(s) of wee1 in the early stages of mouse ovarian follicles. The expression of wee1 and the correlated cell-cycle components, namely cdc2, cyclin B1, and cdc25C, were evaluated by immunohistochemistry. In addition, the expression of Tyr15-phosphorylated cdc2 (cdc2-p) was also examined to determine whether wee1 kinase phosphorylates cdc2 existed. Each component except cdc25C was found cytoplasmic in the oocytes at all stages of follicles, while cdc25C was not detected in primordial follicles. It was found primarily in ovarian somatic cells and to a small extent in granulosa cells of the growing follicles. To further confirm the expression of cell-cycle components in the primordial follicular oocytes, day1 ovaries were enzymatically and mechanically dissociated, then oocytes were isolated from somatic including pre-granulosa cells, and we confirmed that cdc2-p was expressed in oocytes of primordial follicles. From the results of the present study, we concluded wee1, without the counteracting cdc25C, would cause meiotic arrest of oocytes by the inhibitory phosphorylation of cdc2. The expression of all these proteins in the granulosa cells of growing follicles may regulate their mitosis concurrently with the growth of oocytes and follicles.

• Molecules and Cells
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• 제41권5호
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• pp.436-443
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• 2018

The actin cytoskeleton plays a key role in the entry of mitosis as well as in cytokinesis. In a previous study, we showed that actin disruption delays mitotic entry at G2/M by sustained activation of extracellular signal-related kinase 1/2 (ERK1/2) in primary cells but not in transformed cancer cell lines. Here, we examined the mechanism of cell cycle delay at G2/M by actin dysfunction in IMR-90 normal human fibroblasts. We observed that de-polymerization of actin with cytochalasin D (CD) constitutively activated ribosomal S6 kinase (RSK) and induced inhibitory phosphorylation of Cdc2 (Tyr 15) in IMR-90 cells. In the presence of an actin defect in IMR-90 cells, activating phosphorylation of Wee1 kinase (Ser 642) and inhibitory phosphorylation of Cdc25C (Ser 216) was also maintained. However, when kinase-dead RSK (DN-RSK) was overexpressed, we observed sustained activation of ERK1/2, but no delay in the G2/M transition, demonstrating that RSK functions downstream of ERK in cell cycle delay by actin dysfunction. In DN-RSK overexpressing IMR-90 cells treated with CD, phosphorylation of Cdc25C (Ser 216) was blocked and phosphorylation of Cdc2 (Tyr 15) was decreased, but the phosphorylation of Wee1 (Ser 642) was maintained, demonstrating that RSK directly controls phosphorylation of Cdc25C (Ser 216), but not the activity of Wee1. These results strongly suggest that actin dysfunction in primary cells activates ERK1/2 to inhibit Cdc2, delaying the cell cycle at G2/M by activating downstream RSK, which phosphorylates and blocks Cdc25C, and by directly activating Wee1.

• Journal of Information Science Theory and Practice
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• 제7권1호
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• pp.52-71
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• 2019

An insider threat is a threat that comes from people within the organization being attacked. It can be described as a function of the motivation, opportunity, and capability of the insider. Compared to managing the dimensions of opportunity and capability, assessing one's motivation in committing malicious acts poses more challenges to organizations because it usually involves a more obtrusive process of psychological examination. The existing body of research in psycholinguistics suggests that automated text analysis of electronic communications can be an alternative for predicting and detecting insider threat through unobtrusive behavior monitoring. However, a major challenge in employing this approach is that it is difficult to minimize the risk of missing any potential threat while maintaining an acceptable false alarm rate. To deal with the trade-off between the risk of missed catches and the false alarm rate, we propose a unified psycholinguistic framework that consolidates multiple text analyzers to carry out sentiment analysis, emotion analysis, and topic modeling on electronic communications for unobtrusive psychological assessment. The user scenarios presented in this paper demonstrated how the trade-off issue can be attenuated with different text analyzers working collaboratively to provide more comprehensive summaries of users' psychological states.

• Journal of Information Science Theory and Practice
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• 제1권2호
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• pp.36-57
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• 2013

Blogs are readily available sources of opinions and sentiments which allows bloggers to exert a certain level of influence over the blog readers. Previous studies had attempted to analyze blog features to detect influence within the blogosphere, but had not studied in details influence at the blogger-level. Other studies studied bloggers' personalities with regards to their propensity to blog, but did not relate the personalities of bloggers to influence. Bloggers may differ in their way or manner of exerting influence. For example, bloggers could be active participants or just passive shares, or whether they express ideas in a rational or subjective manner, or they are received positively or negatively by the readers. In this paper, we further analyze the engagement style (frequency, scope, originality, and consistency of the blog postings), persuasion style (appeals to reasons or emotions), and persona (degree of compliance) of individual bloggers. Methods used include similarity analysis to detect the sharing-creating aspect of engagement style, subjectivity analysis to measure persuasion style, and sentiment analysis to identify persona style. While previous studies analyzed influence at blog site level, our model is shown to provide a fine-grained influence analysis that could further differentiate the bloggers' influence style in a blog site.

• 대한감각통합치료학회지
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• 제1권1호
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• pp.25-37
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• 2003

Objective : To explore the effectiveness of sensory integration program of home-based outcomes in child with sensory modulation disorder. Methods : This study used the simple case study. The subjects were three children diagnosed as developmentally delayed who 14 month and 26 month males and a 15 month female. After initial evaluation, parents were educated on sensory diet and Wilbarger protocol method for 30 minutes twice for home-based treatment and asked to make out daily treatment planning. To measure improvement of children, we used for the Denver Developmental Screening Test II(DDST II), Wee Functional Independence Measure(WeeFIM), hand function, functional ability, oral motor function, Sensory Profile(Dunn, 1999). Results : After the home-based program, the scored of the Denver Developmental Screening Test II(DDST II), Wee Functional Independence Measure(WeeFIM), hand function, functional ability, oral motor function, Sensory Profile(Dunn, 1999) were higher rather than initial evaluation after the home-based program. Conclusion : The home-based program is effective for children with sensory modulation disorder but parents had to be educated by therapist specific evaluation and treatment in sensory integration.