• Nutrition Research and Practice
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• 제13권2호
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• pp.95-104
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• 2019

BACKGROUND/OBJECTIVES: Inflammatory Bowel Disease (IBD) has rapidly escalated in Asia (including Korea) due to increasing westernized diet patterns subsequent to industrialization. Factors associated with endoplasmic reticulum (ER) stress are demonstrated to be one of the major causes of IBD. This study was conducted to investigate the effect of Lycium barbarum (L. barbarum) on ER stress. MATERIALS/METHODS: Mouse embryonic fibroblast (MEF) cell line and polarized Caco-2 human intestinal epithelial cells were treated with crude extract of the L. chinense fruit (LF). Paracellular permeability was measured to examine the effect of tight junction (TJ) integrity. The regulatory pathways of ER stress were evaluated in MEF knockout (KO) cell lines by qPCR for interleukin (IL) 6, IL8 and XBP1 spliced form (XBP1s). Immunoglobulin binding protein (BiP), XBP1s and CCAAT/enhancer-binding homologous protein (CHOP) expressions were measured by RT-PCR. Scanning Ion Conductance Microscopy (SICM) at high resolution was applied to observe morphological changes after treatments. RESULTS: Exposure to LF extract strengthened the TJ, both in the presence and absence of inflammation. In polarized Caco-2 pretreated with LF, induction in the expression of proinflammatory marker IL8 was not significant, whereas ER stress marker XBP1s expression was significantly increased. In wild type (wt) MEF cells, IL6, CHOP and XBP1 spliced form were dose-dependently induced when exposed to $12.5-50{\mu}g/mL$ extract. However, absence of XBP1 or $IRE1{\alpha}$ in MEF cells abolished this effect. CONCLUSION: Results of this study show that LF treatment enhances the barrier function and reduces inflammation and ER stress in an $IRE1{\alpha}$-XBP1-dependent manner. These results suggest the preventive effect of LF on healthy intestine, and the possibility of reducing the degree of inflammatory symptoms in IBD patients.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1310-1315
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• 2019

Hyaluronidases enhance therapeutic drug transport by breaking down the hyaluronan barrier to lymphatic and capillary vessels, facilitating their tissue absorption. Commercially available hyaluronidases are bovine in origin; however, they pose risks such as bovine spongiform encephalopathy. The present study aimed to develop a novel, highly active hyaluronidase and assess its function. Therefore, in order to find the most efficient active hyaluronidase, we produced several shortened hyaluronidases with partial removal of the N- or C-terminal regions. Moreover, we created an enzyme that connected six histidines onto the end of the hyaluronidase C-terminus. This simplified subsequent purification using $Ni^{2+}$ affinity chromatography, making it feasible to industrialize this highly active recombinant hyaluronidase which exhibited catalytic activity equal to that of the commercial enzyme. Therefore, this simple and effective isolation method could increase the availability of recombinant hyaluronidase for research and clinical purposes.

• Clinical and Experimental Pediatrics
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• 제62권8호
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• pp.307-311
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• 2019

Purpose: Necrotizing enterocolitis (NEC) is one of the most serious complications of prematurity. Many risk factors can contribute to the development of NEC. The epidermal growth factor (EGF) plays a major role in intestinal barrier function, increases intestinal enzyme activity, and improves nutrient transport. The aim of this study was to assess the role of epidermal growth factor in the development of NEC in preterm neonates. Methods: In this study, 130 preterm neonates were included and divided into 3 groups, as follows: group 1, 40 preterm neonates with NEC; group 2, 50 preterm neonates with sepsis; and group 3, 40 healthy preterm neonates as controls. The NEC group was then subdivided into medical and surgical NEC subgroups. The serum EGF level was measured using enzyme-linked immunosorbent assay. Results: Serum EGF levels (pg/dL) were significantly lower in the NEC group (median [interquartile range, IQR], 9.6 [2-14]) than in the sepsis (10.1 [8-14]) and control groups (11.2 [8-14], P<0.001), with no significant difference between the sepsis and control groups, and were positively correlated with gestational age (r=0.7, P<0.001). A binary logistic regression test revealed that low EGF levels and gestational ages could significantly predict the development of NEC. The receiver-operating characteristic curve for EGF showed an optimal cutoff value of 8 pg/mL, with 73.3% sensitivity, 98% specificity, and an area under the curve of 0.92. Conclusion: The patients with NEC in this study had significantly lower serum EGF levels (P<0.001), which indicated that EGF could be a reliable marker of NEC in preterm neonates.

• 생체재료학회지
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• 제22권4호
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• pp.346-351
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• 2018

Background: Carbonate apatite ($CO_3Ap$) and silica-calcium phosphate composite (SCPC) are bone substitutes with good prospect for dental application. SCPC creates a hydroxyapatite surface layer and stimulate bone cell function while, $CO_3Ap$ induce apatite crystal formation with good adaptation providing good seal between cement and the bone. Together, these materials will add favorable properties as a pulp capping material to stimulate mineral barrier and maintain pulp vitality. The aim of this study is to investigate modification of $CO_3Ap$ cement combined with SCPC, later term as $CO_3Ap-SCPC$ cement (CAS) in means of its chemical (Calcium release) and physical properties (setting time, DTS and pH value). Methods: The study consist of three groups; group 1 (100% calcium hydroxide, group 2 $CO_3Ap$ (60% DCPA: 40% vaterite, and group 3 CAS (60% DCPA: 20% vaterite: 20% SCPC. Distilled water was employed as a solution for group 1, and $0.2mol/L\;Na_3PO_4$ used for group 2 and group 3. Samples were evaluated with respect to important properties for pulp capping application such as pH, setting time, mechanical strength and calcium release evaluation. Results: The fastest setting time was in $CO_3Ap$ cement group without SCPC, while the addition of 20% SCPC slightly increase the pH value but did not improved the cement mechanical strength, however, the mechanical strength of both $CO_3Ap$ groups were significantly higher than calcium hydroxide. All three groups released calcium ions and had alkaline pH. Highest pH level, as well as calcium released level, was in the control group. Conclusion: The CAS cement had good mechanical and acceptable chemical properties for pulp capping application compared to calcium hydroxide as a gold standard. However, improvements and in vivo studies are to be carried out with the further development of this material.

• 생약학회지
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• 제51권4호
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• pp.349-359
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• 2020

Gastroesophageal reflux disease (GERD) is a disease that stomach contents continually refluxing, and is currently on the rise worldwide. The purpose of this study is to find natural materials that can reduce side effects and effectively treat chronic acid reflux esophagitis (CARE), one of GERD. First, the antioxidant activity was confirmed by varying the mixing ratio of Coptidis Rhizoma and Evodiae Fructus, which are effective against chronic reflux esophagitis. After, animal experiments were conducted using a 1:1 (CE) and 1:2 (CEE) combination ratio of Coptidis Rhizoma and Evodiae Fructus, which had the best antioxidant efficacy. Gross lesion of esophageal mucosa after CE or CEE treatment showed a superior enhancement compared with that of CARE control rats. Additionally, its inhibited MAPK phosphorylation and led NF-κB inactivation through the suppression of IκBα phosporylation by regulating Nrf2/Keap-1, and NF-κB inactivation induced reduced protein expressions including inflammatory mediators and cytokines. Moreover, its improved esophageal barrier function through upregulating protein expressions of tight junction protein, whereas downregulating protein expressions of MMPs. Taken together, a mixture of Coptidis Rhizoma and Evodiae Fructus can attenuate the esophageal mucosal ulcer by inhibiting MAPK and NF-κB pathway, and upregulating proteins associated with tight junction.

• Journal of Radiation Protection and Research
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• 제45권4호
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• pp.163-170
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• 2020

Background: Gut microflora contributes to the nutritional metabolism of the host and to strengthen its immune system. However, if the intestinal barrier function of the living body is destroyed by radiation exposure, the intestinal bacteria harm the health of the host and cause sepsis. Therefore, this study aims to trace short-term radiation-induced changes in the mouse gut microflora-dominant bacterial genus, and analyze the degree of intestinal epithelial damage. Materials and Methods: Mice were irradiated with 0, 2, 4, 8 Gy X-rays, and the gut microflora and intestinal epithelial changes were analyzed 72 hours later. Five representative genera of Actinobacteria, Firmicutes, and Bacteroidetes were analyzed in fecal samples, and the intestine was pathologically analyzed by Hematoxylin-Eosin and Alcian blue staining. In addition, DNA fragmentation was evaluated by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Results and Discussion: The small intestine showed shortened villi and reduced number of goblet cells upon 8 Gy irradiation. The large intestine epithelium showed no significant morphological changes, but the number of goblet cells were reduced in a radiation dose-dependent manner. Moreover, the small intestinal epithelium of 8 Gy-irradiated mice showed significant DNA damaged, whereas the large intestine epithelium was damaged in a dose-dependent manner. Overall, the large intestine epithelium showed less recovery potential upon radiation exposure than the small intestinal epithelium. Analysis of the intestinal flora revealed fluctuations in lactic acid bacteria excretion after irradiation regardless of the morphological changes of intestinal epithelium. Altogether, it became clear that radiation exposure could cause an immediate change of their excretion. Conclusion: This study revealed changes in the intestinal epithelium and intestinal microbiota that may pave the way for the identification of novel biomarkers of radiation-induced gastrointestinal disorders and develop new therapeutic strategies to treat patients with acute radiation syndrome.

• Journal of Korean Dental Science
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• 제15권1호
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• pp.51-60
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• 2022

Purpose: The aim of this study was to evaluate the bio-durability and bone regeneration capacity of the non-cross-linked collagen membrane in rabbit calvarial defect models. Materials and Methods: Four circular defects with 8 mm diameter were made in each of calvarium of 10 male rabbits. The following groups was randomly assigned to each defect - 1) Control, 2) membrane group containing non-cross-linked collagen membrane only (M), 3) bone graft group (B), 4) bone graft with membrane group (B+M). Animals were sacrificed and samples were harvested at 2 weeks (n=5) and 8 weeks (n=5). Histologic sections were prepared and histomorphometric analysis was performed. Result: Histologic results showed well adaptation of the non-cross-linked membrane on each defect and normal healing response at 2 weeks. At 8 weeks, the membranes were partially biodegraded. Histomorphometrically, B and B+M group showed the significantly greater total augmented area (B+M group, 10.44±1.49, P=0.016; B group, 9.13±0.53, P=0.032) and new bone formation (B+M group, 2.89±0.93, P=0.008; B group, 2.85±1.15, P=0.008) compared to control group. Collapsing of the central portion of the membrane, membrane group showed greater value in new bone formation at 8 weeks (1.78±0.68, P=0.032). Conclusion: Within the limitations of this study, the non-cross-linked collagen membrane fabricated using the improved decellularized method was shown to be effective for the regeneration of calvarial bone defects. In addition, prolonged barrier function might be provided using this collagen membrane.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.877-884
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• 2022

Probiotics are microorganisms that can benefit host health when ingested in a live state, and lactic acid bacteria are the most common type. Among fungi, Saccharomyces boulardii (SB) is the only strain known to have a probiotic function with beneficial effects on colitis; however, information on other probiotic yeast strains is limited. Therefore, this study aimed to discover yeast strains expressing intestinal anti-inflammatory activities by exhibiting probiotic properties in dextran sodium sulfate (DSS)-induced colitis mice model. Nuruk (Korean traditional fermentation starter) containing various microbial strains was used as a source for yeast strains, and S. cerevisiae 28-7 (SC28-7) strain was selected with in vitro and in vivo characteristics to enable survival in the intestines. After 14 days of pretreatment with the yeast strains, DSS was co-administered for six days to induce colitis in mice. The results revealed that the disease activity index score was lowered by SC28-7 treatment compared to the DSS group, and the colon length and weight/length ratio were recovered in a pattern similar to that of the normal group. SC28-7 administration significantly reduced the secretion of pro-inflammatory cytokines in the serum and modified the mRNA expression of inflammatory cytokines (interleukin-1β, transforming growth factor-β, and interferon-γ) and proteins involved in gut barrier functions (mucin 2, mucin 3, zonula occludens-1, and occludin) in colon tissues. These results indicate that SC28-7 attenuates DSS-induced colon damage and inflammation, supporting its future use as a probiotic yeast for treating and preventing intestinal inflammatory diseases such as inflammatory bowel disease.

• 한국정보통신학회논문지
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• 제26권9호
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• pp.1279-1292
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• 2022

신체적 불편함으로 인해 기존의 마우스와 같은 입력 장치의 사용이 힘든 사용자에게 도움이 될 수 있는 시스템으로 얼굴 인식과 Pyautogui 마우스 제어 기반의 비접촉식 입력 기법을 제안한다. 본 연구는 특히 화면 확대/축소나 스크롤 기능과 같이 웹 서핑을 보다 편리하게 돕는 기능이 포함되어 있으며, 개인의 신체적 차이 및 웹 사용 습관을 고려해 여러 설정값을 조정할 수 있도록 하였다. 또한, 기존의 시스템에서 한계점으로 제시되었던 눈 피로도에 대한 문제도 해결하였다. 추가로 고성능 CPU나 GPU 환경이 요구되지 않고 별도의 트래커 장치나 고성능 카메라 또한 필요하지 않다. 이러한 연구를 통해 손을 쓰기 어려운 장애인 및 노인들의 웹 접근성을 높여 배리어프리 실현에 기여하고자 한다.

• 보건행정학회지
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• 제4권1호
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• pp.138-175
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• 1994

The objectives of this study are (i) to review current situations and problems of the occupational health care system with emphasis on reforming the organizations and services, (ii) to find out a disirable occupational health system model based on integration of the occupational health system and the general health system, and finally, (iii) to suggest policy implications in occupational health services in the light of objectives of the newly emerging national health insurance reform in Korea. The major policy implications of this study are as follows: 1. In the long-run, within the occupational health system, preventive occupational health services such as employees' physical check-up, working environment examination, etc should financially be integrated with industrial accident compensation insurance. Currently separately paying expenses for each different category of services by the owner of an enterprise should be disbursed once through the payment of contributions of industrial accident compensation insurance. And then, it is necessary to strengthen and expand the role and function of industrial accident compensation insurance to cover preventive occupational health services. 2. The occupational health system should be integrated with general health system for its effective management. For the short-term policy, it is necessary to eliminate fiscal and access barrier between industrial accident compensation insurance and national health insurance by means of ex post facto settlement of accounts. The duplication of employees' physical check- ups between under the health insurance program and under the industrial health services must be coordinated in a manner either through mutual authorization by the two parties concerned or through merge into the health insurance. 3. The intent of current employees' physical check-up system focused on detection of occupational diseases, should be converted to an idea of medical surveillance system or biological moritoring system. The introduction of medical surveillance or biological monitoring system is a necessary condition to build a positive, effective and inexpensive occupational health care system.