Conceptual Study for Tissue-Regenerative Biodegradable Magnesium Implant Integrated with Nitric Oxide-Releasing Nanofi bers

Jin‑Kyung Jeon,Hyunseon Seo,Jimin Park,Soo Ji Son,Yeong Rim Kim,Eun Shil Kim,Jong Woong Park,Woong‑Gyo Jung,Hojeong Jeon,Yu‑Chan Kim,Hyun‑Kwang Seok,Jae Ho Shin,Myoung‑Ryul Ok 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The excessive initial corrosion rate of Mg is a critical limitation in the clinical application of biodegradable Mg implantsbecause the device loses its fi xation strength before the fractured bone heals. This study suggests a new approach to overcomethis hurdle by accelerating tissue regeneration instead of delaying the implant biodegradation. As angiogenesis is anessential process in early bone regeneration, a Mg implant coated with electrospun nanofi bers containing nitric oxide (NO),which physiologically promotes angiogenesis, is designed. The integrated device enables adjustable amounts of NO to bestored on the NO donor-conjugated nanofi ber coating, stably delivered, and released to the fractured bone tissue near theimplanted sites. An in vitro corrosion test reveals no adverse eff ect of the released NO on the corrosion behavior of the Mgimplant. Simultaneously, the optimal concentration level of NO released from the implant signifi cantly enhances tube networkformation of human umbilical vein endothelial cells without any cytotoxicity problem. This indicates that angiogenesis canbe accelerated by combining NO-releasing nanofi bers with a Mg implant. With its proven feasibility, the proposed approachcould be a novel solution for the initial stability problem of biodegradable Mg implants, leading to successful bone fi xation.

Pseudomonas sp. CB-33이 생산하는 β-Xylosidase의 특성

유진환,김현구,김치경,임재윤 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.2

Pseudomonas sp. CB-33 균주의 배양 상등액으로부터 ammonium sulfate 침전법, PEI 침전법, DEAE-Sephadex column chromatography, gel column chromatography 그리고 preparative disc gel electrophoresis를 이용하여 β-xylosidase를 정제하였다. 정제된 효소의 Km 값은 4.6 mM이었다. 효소활성의 최적 pH는 7.0이었으며 pH 6.5~9 범위에서 안정하였다. 최적 활성온도는 45℃였으며, 각 온도에서 30분 동안 정치하였을 때 35℃까지 안정하였다. SDS-PAGE에 의해 효소의 분자량을 측정해 본 결과 약 44,000dalton이었다. HG^2+, Cu^2+ 그리고 Zn^2+는 효소활성을 저해하였고, 여러 화학변형제로 효소에 처리해 본 결과 tyrosine과 tryptophan이 효소활성에 관여하고 있을 것으로 추정된다. 여러가지 기질에 대한 특이성을 조사해 본 결과 pNPX 뿐만 아니라 pNPA도 분해하였다. Xylan에 endoxylanase만을 작용시켰을 때보다 β-xylosidase와 endoxylanase를 혼합작용 시켰을 때 xylan의 가수분해도는 약 2배 정도 증가하였다. 그리고 Pseudomonas sp. CB-33 균주가 생산하는 xylan 분해효소는 oat spelt xylan보다 birchwood xylan에 보다 효과적으로 작용하였다. The β-xylosidase was purified 99-fold from the culture supernatant of Pseudomonas sp. CB-33 by ammonium sulfate precipitation, PEI precipitation, DEAE-Sephadex column chromatography, Sephadex G-75 gel filtration chromatography and preparative disc gel electrophoresis. Molecular weight of the enzyme was estimated to be 44,000 by SDS polyacrylamide gel electrophoresis. The enzyme has a pH optimum for activity at 7.0 and is stable over pH 6.5~9.0. The optimal temperature of the enzyme was 45℃, and it enzymatic activity was completely inactivated at 55℃ for 30 min. Km value of the enzyme for p-nitrophenyl- β-D-xylopyranoside was calculated to be 4.6 mM. The effect of various reagents on the β-xylosidase activity was investigated. The enzyme activity was completely inhibited by Hg^2+, Cu^2+, and Zn^2+. The β-xylosidase was inactivated by tryptophan-specific reagent, N-bromosuccinimide and the enzyme was competitively inhibited by xylose. The β-xylosidase and endoxylanase from Pseudomonas sp. CB-33 hydrolized xylan synergically. The purified enzyme also showed α-L-arabinofuranosidase activity.

혈관외피종 -1증례 보고-

강유미,지미경,양기화,강석진,김병기,김선무,정수일 대한병리학회 1990 Journal of Pathology and Translational Medicine Vol.25 No.5

혈관외피종 -1증례 보고-

강유미,지미경,양기화,강석진,김병기,김선무,정수일 대한병리학회 1990 Journal of Pathology and Translational Medicine Vol.24 No.2

한국인 환자에서 Vancomycin의 집단약동학 (Population Pharmacokinetics)에 관한 연구

유경상,배균섭,이주연,조주연,장인진,신상구,신완균 大韓臨床藥理學會 1998 臨床藥理學會誌 Vol.6 No.2

유지놀 처리된 상아질 표면의 상아질 접착제의 전단결합강도에 관한 연구

유화성,최경규,최기운,박상진 대한치과보존학회 2000 Restorative Dentistry & Endodontics Vol.25 No.4

In this study, shear bond strength of two bonding systems were measured and appearance of dentin surfaces were observed with SEM according to the storage time of eugenol on dentin surface, thus evaluated the effect of eugenol on bond strength of two dentin bonding systems. Control groups were directly bonded to dentin surface with One Step, Prime & Bond 2.1. Experimental groups were divided into experimental I and II according to dentin bonding agents. After eugenol application, dentin surfaces were bonded with One Step and Prime & Bond 2.1 according to the each storage time of immediately, 3min, 24hour, 48hour and 1week, and then control and experimental groups were filled with light cured composite resin(Z-100). After 24 hours water storage at 37℃, all samples were subjected to a shear load to fracture at a cross head 1.0mm/min with Instron universal testing machine(No. 4467) . Etched dentin surface storaged for each time of immediately, 3min, 24hour, 48hour and 1week after eugenol application were observed under Scanning Electron Microscope(Hitachi S-2300) at 20kvp. The data were evaluated statistically with two-way ANOVA and Tukey's HSD. The results were as follows; 1.Shear bond strengths were higher in control groups than in the experimental groups. 2.As storage time was increased after eugenol application, the shear bond strengths were decreased in experimental groups 3.In experimental I, II the shear bond strengths were the lowest in which storage time was 1week after eugenol application. 4.As storage time was increased after eugenol application, etched dentin surfaces showed obstructed dentinal tubule.

서방형 Diltiazem제제의 개발을 위한 약동학/약력학적 특성 검토

유경상,배균섭,조주연,장인진,신상구 大韓臨床藥理學會 1998 臨床藥理學會誌 Vol.6 No.2

석이로부터 분리한 페놀성 화합물의 phospholipase A_2 저해활성

김진우,송경식,유익동,장현욱,유승현,배강규,민태진 충남대학교 생물공학연구소 1997 생물공학연구지 Vol.5 No.-

호알카리성 진균 Cephalosporium sp. RYM-202가 생산하는 alkaline xylanase (CX-III)의 작용에 의해 xylan 기질로부터 생성되는 주요 가수분해 산물은 xylobiose와 중합도가 4 이상인 xylooligosaccharides이었다. 이 효소는 xylobiose에 대한 분해능을 가지고 있지 않지만 xylotriose로부터는 xylobiose를, xylotetraose로부터는 xylobiose와 xylotriose를 주산물로 형성하였다. 이러한 결과들은 CX-III가 transglycosidase 활성을 소유하는 전형적인 endo-type xylanase임을 보여준다. N-bromosuccinimide에 의한 CX-III의 화학적 변화 실험 결과 효소 1분자 당 2개의 tryptophan 잔기가 활성에 관여하는 것으로 나타났다. 그러나 iodoacetamide 및 diethylpyrocarbonate에 의한 효소활성의 저해효과는 나타나지 않음으로써 이 효소의 활성부위에 cysteine과 histidine 잔기가 필수적이지 않음이 확인되었다. The hydrolysis products formed from birchwood xylan by the action of an alkaline xylanase (CX-III) from alkalophilic Cephalosporium sp. RYM-202 were xylobiose and xylooligosaccharides polymerized with more than 4 sugar molecules. This enzyme was not active on xylobiose but readily attacked xylotriose accumulating xylobiose as a major product. The predominant end-products from xylotetraose by CX-III were xylobiose and xylotriose. These results indicate that the enzyme is typically endo-type xylanase possessing transglycosidase activity. Chemaical modification of CX-III with N-bromosuccinimide revealed that two tryptophan residues per molecule of CX-III were essential for its catalytic activity on xylan. On the other hand, iodoacetamide and diethylpyrocarbonate did not influence the activity of the enzyme, suggesting that cysteine and histidine residues are not involved in the active site of this alkaline xylanase.

면접조사를 통한 초등학생의 영양교육 실태 및 실천도 조사

오유진,이영미,김정현,안홍석,김정원,박혜련,서정숙,김경원,권오란,박혜경,이은주,성현이 대한지역사회영양학회 2008 대한지역사회영양학회지 Vol.13 No.4

This study investigated the experience and practice of elementary school students on nutrition education. The data were collected from 217 male and female students attending 5-6th grade elementary schools in Seoul and Kyunggi-Do from March to June 2007, interviewing face to face by a nutrition teacher and 3 interns of a nutrition teacher. The results were as follows: 86.5% of the subjects learned about ‘Table etiquette’, ‘Reasons for eating fruits and vegetables’ (78.7%), ‘Food waste and environment’ (72.3%), ‘Healthy snacks’ (55.7%), ‘Food sanitation’ (52.3%), ‘Food culture of foreign countries’ (48.1%). Nutrition education experience was significantly different by gender. A total of 43.5% boys responded that they never learned about ‘basic food preperation’ (p < 0.01). They had learned ‘Nutrients for body’ and ‘Food waste and environment’ in school, ‘Healthy weight loss’, ‘Food culture of foreign countries’, ‘Food circulation’ on television, Most content (‘Table etiquette’, ‘Simple cooking’, ‘Food sanitati n’, ‘Eating behaviors for health’, ‘Reasons for eating fruits and vegetables’, ‘Healthy snacks’) was learned from parents. The practice after nutrition education was higher in ‘Table etiquette’ (2.14), ‘Eating fruits and vegetables’ (2.07) than others compared with education experience. The most reason of non-practice on nutrition information was ‘Troublesome’. In ‘Nutrients for body’, a boy answered ‘Difficult for practice’ 20.0%, a girl answered ‘Difficult to understand’ 32.6%, showing a significant difference between the gender groups (p < 0.001). They remembered the ‘Nutrients for body’ (49.6%), ‘Food sanitation’ (44.5%) because of ‘important content’,‘Basic food preparation’ (40.6%), ‘Food culture of foreign countries’ (36.3%) because of ‘interesting content’, ‘Healthy weight loss’ (52.0%), ‘Eating behavior for health’ (44.5%) and ‘Healthy snacks’ (33.7%) because of ‘need for my health’.

Chromium picolinate가 고지방, 고설탕 식이를 섭취한 흰쥐의 체내 포도당, 지질 농도에 미치는 영향

오유진,진윤경,장유경 漢陽大學校 韓國生活科學硏究所 2001 韓國 生活 科學 硏究 Vol.- No.19

This study was carried out to investigate the effect of chromium picolinate supplementation on the metabolism of rats. Male Sprague-Dawley rats were divided into 3 groups and each group had 16 rats. Three experimental diets of CT(control), HS(high sucrose) and HF(high fat) were fed for 10 weeks and then chromium picolinate were supplemented to HS and HF groups for 6 weeks. Eight rats from each group were sacrificed after 10 weeks and another 8 rats from each group were sacrificed after 16 weeks. The results from this experiment were summarized as follows: The change of calorie intake and body weight was not significantly different among three groups after chromium picolinate supplementation. The plasma glucose and insulin concentration in CT group tended to increase after 16 weeks but those in HS and HF groups tended to decrease after chromium picolinate supplementation. The plasma triglyceride and cholesterol concentration of CT group tended to be higher than those of HS and HF groups which were supplemented by chromium picolinate. Our results indicate that chromium picolinate tend to reduce blood glucose, insulin, triglyceride, and cholesterol level but increase HDL-cholesterol level.