Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

( Ji Hyun Lee ),( Jeong In Lee ),( So Yeon Park ),( Yoo Kyeong Jang ),( You Bin Lim ),( Hye Yoon Lee ),( Young Min Jung ),( Hae Chang Lee ),( Jong Hwa Lee ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc)n, n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc)n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

아시아 지역 폐렴 구균의 항균제 내성 현황 및 변화 양상 : Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study

정숙인,김나영,손준성,기현균,고관수,서지연,장현하,김연숙,오원섭,백경란,이남용,송재훈,항생제 내성 감시를 위한 아시아 연합 (ANSORP) 대한감염학회 2004 감염과 화학요법 Vol.36 No.1

목적 : 1980년대부터 페니실린을 비롯한 β-lactam 계열과 비 β-lactam 계열 항균제에 대한 폐렴구균의 항생제 내성이 급격하게 증가하여 국내 뿐 아니라 세계적인 문제로 대두되고 있다. ANSORP 에서는 아시아 지역에서 폐렴구균의 항균제 내성과 그 변화 추이, 내성의 기전 및 위험인자를 분석하고자 본 국제 공동 연구를 시행하였다. 재료 및 방법 : 1999년 11월부터 2001년 8월까지 아시아 지역 12개국의 14개 기관에서 폐렴구균 감염증 환자의 임상 검체로 분리된 침습성 폐렴구균을 대상으로 액체배지 미량희석법을 이용하여 16개 항생제의 MIC를 구하였다. 위험인자의 분석을 위하여 폐렴구균 감염증 환자를 대상으로 의무기록지를 조사하였다. Quellung 반응을 통해 혈청형을 결정하였다. 결과 : 총 685균주 중 52.4%가 페니실린에 대하여 비감수성(중등도 내성 22.9%, 내성 29.5%)을 보였고, 그 빈도는 베트남(92.1%), 스리랑카(85.7%), 홍콩(67.9%), 한국(64.5%)의 순이었다. Erythromycin에 대한 비감수성 비율은 베트남(92.1%), 대만(87.7%), 한국(80.6%), 홍콩(76.8%) 등에서 높게 나타났고, 베트남, 대만, 한국, 홍콩 등의 erythromycin의 MIC_(90)이 32㎍/mL를 넘는 고도내성을 보였다. 홍콩, 싱가포르, 대만, 인도에서는 fluoroquinolone에 대한 내성 균주가 출현하였다. 전체 균주 중 다제내성 균주의 비율은 47.7%였다. 혈청형은 19형과 23형이 가장 많았고, 그 외 6형, 14형 등이 있었다. 페니실린 비감수성 감염증의 위험인자로는 5세 미만(OR=1.7; 95%, CI, 1.2-2.4; P=0.002), 기관지폐질환(OR=2.0; 95%, CI, 1.3-3.1; P=0.003), 악성종양(OR=2.3; 95%, CI, 1.2-4.6; P=0.015), 스테로이드의 사용(OR=2.8; 95%, CI, 1.1-7.4; P=0.032)이 확인되었다. 결론 : 침습성 폐렴구균 균주를 대상으로 한 본 연구의 결과 아시아 국가들에서 페니실린, β-lactam 및 macrolide에 대한 폐렴구균의 내성률 및 내성 정도가 급증하고 있음을 확인하였다. Background : Emergence of pneumococcal resistance became a global issue since 1990s. According to the ANSORP studies with clinical isolates and carriage isolates between 1996 and 1999, some Asian countries showed alarmingly high prevalence of resistance to penicillin and other antimicrobial agents. To investigate the changing trends of pneumococcal resistance, ANSORP study group has performed a multinational surveillance study with invasive pneumococcal isolates from Asian countries. Methods : All isolates from various invasive pneumococcal diseases were prospectively collected from 14 centers in 12 countries between November 1999 to August 2001. Broth microdilution tests with 16 antimicrobial agents were performed according to the NCCLS procedures. Serotyping was performed by means of Quelling reaction with use of group-specific antisera. Results : A total of 685 isolates were collected. Overall, 52.4% of invasive isolates from Asian countries were not susceptible to penicillin (intermediate (1), 22.9%, Resistant (R), 29.5%). Vietnam showed the highest prevalence of penicillin non-susceptibility (1 20.6%, R 71.4%) followed by Sri Lanka (1 71.4%, R 14.3%), Hong Kong (1 24.1%, R 76%) and Korea (1 9.7%, R 54.8%). China (I 19.8%, R 23.4%) and Malaysia (1 9.1%, R 29.5%) also showed remarkable increase in penicillin resistance compared with previous ANSORP data, which were less than 10%. Vietnam (92.1%), Taiwan (87.7%), Korea (80.6%), and Hong Kong (76.8%) showed high prevalence of erythromycin resistance. MIG_(90)S for ciprofloxacin were 4 ㎍/mL (Hong Kong) and 2 ㎍/mL (11 Asian countries except Hong Kong), respectively. Conclusion : Compared with previous data from ANSORP studies, antimicrobial resistance among invasive pneumococcal isolates has markedly increased in Vietnam, Sri Lanka, Taiwan, China, and Malaysia. Continuous surveillance of pneumococcal resistance in Asia is strongly warranted.

The effects of a single bout pilates exercise on mRNA expression of bone metabolic cytokines in osteopenia women

( Chang Sun Kim ),( Ji Yeon Kim ),( Hyo Jin Kim ) 한국운동영양학회 2014 Physical Activity and Nutrition (Phys Act Nutr) Vol.18 No.1

[Purpose] The purpose of this study was to examine the effect of a single bout pilates exercise on mRNA expression of bone metabolic cytokines in elderly osteopenia women. [Methods] We selected 11 people of elderly osteopenia women and loaded a single bout pilates exercise about RPE 10-14 level. The blood samples were collected before, immediately after and 60 minute after pilates exercise, then examined calcium metabolic markers in serum and extracted peripheral blood mononuclear cell (PBMC) from whole blood and confirmed mRNA expression of bone metabolic cytokines from PBMC. To clarify the changes during exercise, we designed repeated measure ANOVA as the control group to perform blood sampling without exercise. [Results] As a result, serum P showed significant interaction effect between group and time (p<.001), the pilates exercise group decreased about 9% at immediately after exercise and 13% during recovery after exercise (p<.05), while the control group showed a tendency to increase. Serum CK also showed a significant interaction between group and time (p<.05), the pilates group significantly increased at immediately after exercise and during recovery after exercise (p<.05) but the control group didn`t have changes. TNF-α and IL-6 mRNA expression in PBMC was significantly increased in the pilates group (p<.01, p<.05), although INF-γ mRNA expression didn`t show statistically significant difference, it tended to increase in the pilates group (NS). [Conclusion] These results suggested that a single bout pilates exercise of elderly osteopenia women cause hypophosphatemia with temporary muscle damage, and it leading high turnover bone metabolic state with to activate both of bone formation and bone resorption.

Marked Decreases of Foxp3 and CTLA-4 Are Associated with Strong Antiviral Effects of Tenofovir in Patients with Chronic Hepatitis B

( Ji Young Kim ),( Chang Wook Kim ),( Yun Hui Kim ),( Seok Cheon Yeom ),( Su Gyeong Lee ),( Hee Yeon Kim ),( Si Hyun Bae ),( Jong Young Choi ),( Seung Kew Yoon ) 대한간학회 2016 춘·추계 학술대회 (KASL) Vol.2016 No.1

Aims: Immune regulatory molecules such as forkhead box P3 (Foxp3) on CD4+ T cell and cytotoxic T lymphocyte-associated antigen 4 CTLA-4) on CD8+ T cell are associated with antiviral effector T cell dysfunction, which influences on T cell exhaustion and persistent viral infection in patients with chronic hepatitis B. These Foxp3 and CTLA-4 are up-regulated in chronic hepatitis B. During antiviral therapy with tenofovir, the expressions of Foxp3 and CTLA-4 could be changed. We investigated the relationship between antiviral effects of tenofovir and the expression of Foxp3 and CTLA-4 during tenofovir treatment in chronic hepatitis B. Methods: Eight patients with chronic hepatitis B under tenofovir treatment were enrolled for detection of Foxp3 on CD4+ T cell and CTLA-4 on CD8+ T cell. Peripheral blood mononuclear cells were isolated from these subjects before tenofovir treatment (T0), 3 month (T3) and 6 month (T6) during tenofovir treatment. For antiviral effect analysis, serum HBV DNA levels were checked at same time. The expressions of Foxp3 and CTLA-4 on T cells were monitored by flow cytometry. Results: Three patients (3 of 8) showed marked decreases of Foxp3 and CTLA-4 during tenofovir therapy (group 1). Five patients (5 of 8) showed minimal changes of Foxp3 or CTLA-4 during tenofovir therapy (group 2). Group 1 showed complete virologic response within 6 month therapy regardless of baseline HBV DNA level but, group 2 showed complete virologic response within 6 month therapy only in patients with low baseline HBV DNA level (< 7log HBV DNA). Conclusions: Among the patients with chronic hepatitis B, the patients who showed marked decrease of Foxp3 and CTLA-4 during tenofovir therapy are associated with strong antiviral effects of tenofovir regardless of baseline HBV DNA level. This finding suggests that restoration of HBV-specific T cell strengthens the antiviral effects of tenofovir.

A Comparison and Analysis of CSAT Reading Texts Before and After the Use of Criterion-Referenced Assessment (2017 vs. 2018): A Focus on Lexical Complexity

Chang,Ji-Yeon 한국외국어교육학회 2018 한국외국어교육학회 학술대회 자료집 Vol.2018 No.-

The Ministry of Education in Korea (2014) decided to adopt a criterion-referenced assessment approach in the English language section of the 2018 College Scholastic Adaptability Test (CSAT). Accordingly, it became particularly important to ensure a consistent level of difficulty in the English language test across years. Unlike the types of questions, different reading and listening texts are presented each year. Due to the advancement of technology, however, it is comparatively easy to predict their difficulty levels in advance. In this study as part of a larger research project (see Chang (2018)), three categories of lexical factors (lexical density, lexical sophistication, and lexical variation) were compared between the CSAT English reading passages before and after the use of criterion-referenced assessment (2017 and 2018). Fifty reading passages were extracted from the 2017 and 2018 CSAT and were compiled into different corpora, respectively. In total, twenty-five indices from a lexical complexity analyzer (Ai & Lu, 2010; Lu, 2012) were used (one measure for lexical density, five measures for lexical sophistication, and nineteen measures for lexical variation). Independent samples t-tests were conducted, and their results show that there were no statistically significant differences between 2017 and 2018 CSAT reading texts in lexical density, lexical sophistication, and lexical variation. The implications of these results will be discussed.

SNS의 뉴스 콘텐츠 이용동기가 뉴스 콘텐츠 유형별 이용량에 미치는 영향 : 참여행위의 매개효과 검증을 통하여

장지연(Ji Yeon Chang),전가영(Ka Young Jeon),유세경(Sae Kyung Yu) 한국언론정보학회 2020 한국언론정보학보 Vol.104 No.-

본 연구는 변화하는 미디어 환경에서 사람들이 어떠한 목적을 가지고 소셜미디어에서 뉴스를 이용하는지 이용 동기를 알아보고, 대표적 콘텐츠 유형별 이용량에 영향을 미치는 이용자 참여행위의 매개효과 검증을 실시했다. 연구 결과, 유튜브 뉴스 콘텐츠를 이용하는 사람들은 다양성을 충족 받고자 하고, 자신과 유사한 견해를 가진 뉴스를 추구한다는 동기가 강했고, ‘좋아요’표시나 댓글 쓰기, 공유 행위 등 참여행위의 매개 효과를 검증한 결과, 유튜브 뉴스 콘텐츠 이용량에 유사견해의 추구 동기는 매개효과가 없는 직접효과만이 유의하고, 다양성 추구의 동기는 참여행위가 매개되지 않으면 이용량을 예측할 수 없는 완전매개효과가 있는 것으로 나타났다. 카드뉴스 콘텐츠에서는 편리성 및 맞춤제공의 동기와 습관적 소비 동기가 요인으로 추출되었지만 이용자 참여행위는 이용량에 대해 유의한 효과 없이 이용 동기가 이용량에 모두 직접적 영향을 미쳤다. 소셜미디어에 원문 그대로 재매개되는 언론사 뉴스 콘텐츠의 경우 다른 유형과는 차별적으로 시의성 충족의 동기가 가장 중요했다. 최근에 일어난 이슈를 실시간으로 소비하고자 하는 욕구와 더불어 의견 교환 및 견해의 비교 동기 역시 유의하게 나타나 기성 매체의 콘텐츠가 소셜미디어 플랫폼에서 새로운 의미로 재가공된다는 점을 확인했다. 재매개된 언론사 뉴스 이용량에 시의성 충족의 동기는 매개효과가 없는 직접효과만 유의했고, 의견교환 및 견해의 비교 동기는 이용자 참여행위의 완전매개효과를 확인했다. 이 연구는 소셜미디어를 활용한 뉴스 콘텐츠 생산과 유통, 소비과정에서 이용자들의 이용 동기와 참여행위를 고려한 전략을 모색할 수 있도록 돕고, 소셜미디어 뉴스의 균형과 조화를 위한 자료를 제공했다는 점에서 의의가 있다. This study identified the motivations for using 3 different news content types on social media platforms and verified mediating effects of user participatory behaviors that affect the usage of each news content type. Studies have shown that those who use YouTube news content have strong motivation to ‘seek for diversity’ and to ‘pursue news with similar views’. In addition, participatory actions: such as ‘like’, ‘writing comments‘ and ‘sharing‘ mediated ‘seeking for diversity’ motivation and the usage of YouTube news. However motivation for ‘pursuing news with similar views’ had no mediating effect. Card news usage showed that the motivation for ‘convenience and curation’ and ‘habitual consumption’ found to have strong positive relation, but the user participatory behavior had no significant mediating effect on the amount of use. Unlike other news contents, original news that are re-mediated via social media showed to have a positive relationship with the motivation for ‘timeliness’ and ‘exchanging opinions and comparing views’. This result confirmed that as original news content transported into social media, even if the content do not change the meaning for the usage change. The motivation for meeting ‘timeliness’ was only noted to have direct effects towards the usage without any mediated effects, but the motivation for ‘exchanging opinions and comparing views’ confirmed the complete mediating effect of user participation. The research is meaningful in that it helped to explore strategies that took into account users’ motives and participation in the process of producing, distributing and consuming news content using social media.

우리나라 4년제 대학졸업자의 직업교육훈련 성과분석 : 교육투자수익률 추정을 중심으로 With The Estimation for The Rate of Return to investment in Education

장창원,이지연 한국직업능력개발원 1999 직업능력개발연구 Vol.2 No.1

ABSTRACTThe purpose of this study was to provide the practical policy suggestions for the re-vitalization of vocational education and training at the higher level of education. For the purpose, data from ^P Earning Structure Basic Statistics Survey Reportj was re-analyzed with such variables as educational level, gender, individual who have or not a qualification, and the kinds of qualification. Jacob Mincer earnings function was used to explain and predict the differences between groups on the suggested variables by estimating the rate of return to investment in education.The empirical estimation of the rate of return to investment in education was concluded that adults with higher levels of education (Bachelor's degree : 15.8%) were more likely to have a high wages in the labor market than those with less education (High school graduate : 8.6%, Associate degree:11.7%). For the rate of return to investment by education level for those who have a qualification, 13.8 percent was shown to adults with a bachelor's degree, compared with 10.3 percent of persons with associate degree, and 7.4 percent of persons with high school graduate. In contrast, for those who have a non-qualification, 14.9 percent was shown to adults with a bachelor's degree compared with 10.7 percent of persons with associate degree, and 7.4 percent of persons with high school graduate.The rate of return to investment in education for adults who have a non-qualification with bachelor's degrees were 1.1 percent higher than the persons who have a qualification with similar levels of education. This results show the evidence that persons with lower levels of educational attainment were more likely to have a lower wages in the labor market than those who had a higher levels of educational attainment. Futhermore, persons who have a non-qualification with higher levels of educational attainment were more likely to have a higher wages in the labor market compared with persons who have a qualification with higher levels of educational attainment. This result revealed that acquirement of qualification is not important issue to judge the performance of the vocational education and training nor standard for employability for entering labor market. Statistics on educational attainment of the entire population show that graduation from university is not simply an academic honour. Educational attainment reflects admission to a particular position in society and influences even job opportunities. His or her own employability by acquirement of qualification does not value in our society. Most business and industry differentiate between those jobs which require a university degree, regardless of qualifications or skills, and those that do not. Regardless of his or her ability, social status as determined by university graduation, has become more important than employability.For making a change from the degree-oriented toward person's ability-oriented valued society, vocational education and training at the higher level of education must emphasis in a new direction. Followings are the summary policy suggestions for the re-vitalizing vocational education and training at the university, where is the place for development of workforce and for preparing world of work.1) Most Korean youth want to go to four-year university after high school. The percentage of high school graduates who indicated plans to enter a four-year university increased to "get a better job" and "make more money". However, a large percentage of graduates from four year universities have a significant problem finding employment. Higher level of education must play a important role to make students as a employable person during their 4 year of campus life. Thus, vocational education and training must emphasis at the university level with changing curriculum structure.2) Curriculum at the higher level of education of the 21century may focus more on helping students transferable workplace competencies and advanced work-related technology in a variety method rather than a simple theoritical knowledge delivery in one way communication teaching structure.3) Changes in qualification system may emphasis more on workplace readiness and assessment process with collaborative partnership with business/industry and university.4) Much attention must directed to the role and responsibility of 4-year university in creating and disseminating the practical and advanced knowledge and technology for those who can meaningful transfer university to work beyond Bachelor's degree only.

대학에서의 교양 영어 교육에 대한 성인학습자의 요구 분석

장지연(Chang, Ji-Yeon) 한국영어학회 2023 영어학 Vol.23 No.-

With the increase in the number of adult learners pursuing higher education, there is a growing necessity to identify their needs for college English education. In this study, a survey was conducted among adult learners enrolled in a lifelong education college at a university in Seoul. The collected responses underwent both quantitative and qualitative analyses. The findings indicate that a larger number of respondents considered learning English to be essential. The primary reason is that English is now a requirement, and some respondents also needed it for everyday use, employment, or job changes. Speaking and listening were chosen as the most necessary areas for learning. Most of the respondents expressed agreement with the necessity of level-differentiated classes, and over half of them supported the administration of a diagnostic test. More adult learners showed a preference for Korean instructors and instruction in Korean in contrast to native English-speaking instructors and instruction in English. The courses the respondents requested mainly centered around fundamental or practical subjects, reflecting their English proficiency levels and characteristics as adult learners. Based on the discussion of the findings, this study offers suggestions to foster effective English learning for adult college students.

Fibroadenoma에 대한 임상적 고찰

장일성,김지연,이희만 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

Fibroadenoma is the most common benign tumor of breast in human female between the age of 20 and 35 years. The great majority of patients should be treated by excisional biopsy to remove the tumor and establish the diagnosis. Authors have reviewed 110 case of fibroadenoma who underwent surgical operation during the period from Jaunary 1990 to Jaunary 1993 at the department of General Surgery in Chungnam National University Hospital. The circumareolar skin incision was selected if the tumor was compatible with benign fibroadenoma on the finding of preoperative mammogram and sonogram. But, the diagnosis was uncertain and the distance from the mass to nipple was over 3 cm, the skin incision was made on the just above the palpable mass. In order to minimize the seroma, hemostasis was taken completely, the use of electrocautery was restricted as possible, a close suction drain was kept to surgical dead space via the main wound by vaccum tube in case of leaving large dead space, and compressive dressing was applied on the defected wound site after the operation. The major complication after the excision of suspicious fibroadenoma was seroma, and its complication rate was about 8% (9/110 cases). But, another complication was not found. The rate of discharge at the first postoperative day was calculated to 73.2 % among the total patients and the remaining of all patients could be discharged at the second postoperative day. In conclusion, the young female who was under suspicion of fibroadenoma must be treated with excision and the excised specimen should undergo histologic examination to rule out carcinoma or to confirm the diagnosis. The associated major complications were revealed to minimal.

마우스 복강 대식세포의 Prostaglandin 합성에 미치는 Bacterial Lipopolysaccharide의 영향

문창현,김지영,최소연,박정미,어수익,이수환 아주대학교 의과학연구소 1996 아주의학 Vol.1 No.1

Production of inflammatory mediators by the host in response to bacterial lipopolysaccharide (LPS) is generally believed to be responsible for the pathogenesis of septic shock. One of the mediators associated with septic shock sequelae are arachidonic acid metabolites, including prostanoids and leukolrienes. Prostaglandin H synthase (PGHS) is a rate-limiting enzyme in prostanoid synthesis of which there were very recently reported two different isotypes. Their activities and expressions are known to be regulated by different mechanisms. Also, differences in response to stimulators have been shown for the different cell types. Even in the macrophage populations, there have been reported diverse profiles of prostanoid synthesis. These discrepancies might be due to the differences in the underlying regulation mechanisms, but presently, little information is available regarding these. Thus, in order to get insights into these discrepancies, firstly, we compared the characteristics of LPS-induced prostanoid production in alveolar macrophages and mouse peritoneal macrophages and secondly, we examined whether variations of glucose concentration affect LPS-induced prostanoid synthesis and PGHS-2 activity in both cell types. Overall responses to LPS were qualitatively similar between both cell types, and LPS-induced TXB2 production was attenuated in high glucose media.