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        검색결과 119

        82.
        2016.10 구독 인증기관·개인회원 무료
        Many transgenic domestic animals have been developed to produce therapeutic proteins in the mammary gland. However, purification of therapeutic proteins from transgenic milk are very important for productivity of recombinant protein. Development of a knock-in vector system is needed to improve production of therapeutic proteins. In this study, we are develop Knock-in vector to express human Erythropoietin protein (hEPO) using Gluthathione S-transferase (GST) fusion system on mouse β-casein exon 3 locus. The knock-in vector consisted of the 5 homologous arm (1.02 kb), GST, PreScission protease site, hEPO cDNA, BGH polyA signal, CMV-EGFP, and 3homologous arm(1.81 kb). The analysis of nucleotide and amino acid sequence revealed that GST-hEPO mRNA is probably translated with the mouse β-casein sequence and the β-casein-GST-hEPO fusion protein is probably secreted by ER-Golgi pathway. After that, the hEPO protein can be cleaved to remove the GST from the fusion protein by PreScission protease during purification of recombinant protein. This knock-in vector may help to create transgenic mouse expressing human Erythropoietin protein via the endogenous expression system of the mouse β-casein gene in the mammary gland.
        83.
        2016.10 구독 인증기관·개인회원 무료
        The production of therapeutic proteins from transgenic animals is one of the most important successes of animal biotechnology. Endostatin is 20 KDa C-terminal fragment derived from type XVIII collagen and an endogenous inhibitor of tumor growth by inhibition of angiogenesis. In this study, we are developed knock-in vector consists of 5’ arm region (1.02 kb), human Endostatin cDNA, CMV-EGFP, and 3’ arm region (1.83 kb). To express Endostatin gene as transgene, the F2A sequence was fused to the 5’ terminal of Endostatin gene and inserted into exon 3 of the β -casein gene. If this knock-in vector is inserted into the porcine β-casein gene locus by homologous recombination, human Endostatin mRNA are expressed using the gene regulatory region of the β-casein. Also, the β-casein and Endostatin fusion protein is translated and Endostatin protein is separated by F2A self cleavage during translation. In conclusion, our knock-in vector may help to create transgenic pig expressing human Endostatin protein via the endogenous expression system of the porcine β-casein gene in the mammary gland.
        84.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Composite resins are developed as restorative materials to improve esthetics and mechanical properties. To improve the physical properties of resin material, resin filler have to be added. However, no imaging method is adopted for resin filler distribution. Optical coherence tomography (OCT) is a optical imaging technique to delineate microscopic structures within biological tissue. The OCT application to dental composites resin and its filler is not described yet. So, this new and advanced optical method is needed for clinical application for evaluation of dental composite resin. To analyze the spatial distribution of dental composite resin and to evaluate the resin restoration in cavity, frequency domain optical coherence tomography (FD-OCT) was used for their analysis. Resin restored tooth was prepared. For morphological observation, serially sectioned teeth, conventional X-ray taking and micro computed-tomography (CT) images were compared with OCT images. The experiment has done to evaluate the success of the resin restoration using 3 dimensional structure OCT image. In this research, OCT is evaluated as a new technique to image resin restoration. The evaluation of resin restored tooth was performed by OCT. Inappropriate restoration such as marginal adaptation, large porosities, internal integrity and poor contour could be detected. Resin filler also could be checked by OCT. The distribution, number, regularity and size of resin filler can be differentiated from several commercial products. Considering the characteristics of the OCT, it can be used to evaluate the defects of resin restoration, resin filler distribution, and internal integrity between resin material and tooth structure. The OCT can be considered to be a new and advanced method for the evaluation of resin restorations.
        4,000원
        85.
        2015.09 구독 인증기관 무료, 개인회원 유료
        Regarding therapies for treatment of corneal wounds, ex vivo corneal culture is the most effective for minimizing expensive animal studies. Eighteen porcine enucleated eyes were soaked in 0.2% povidone iodine solution for disinfection prior to cornea excision. Subsequently, corneas were excised from whole eyes and filled with an agar/medium mixture. Corneas were transferred into culture dishes, after which culture medium was added until the limbus was covered. Cultures were then placed onto a plate rocker to mimic blinking action, followed by incubation at 37°C and 5% CO2. Corneas were harvested on Days 0, 3, and 7 after incubation, and optical coherence tomography (OCT) was performed on Day 7. Two eyes from each group were fixed in 2% glutaraldehyde/4% paraformaldehyde for low-vacuum scanning electron microscopy (LV-SEM), and four eyes from each group were fixed in 10% neutral-buffered formalin for histological analysis. OCT results showed that central corneal thickness significantly increased by Day 7 compared to Day 0 (P<0.05). Using LV-SEM, gaps between endothelial cells were detected on Day 7 of ex vivo culture. In the histological evaluation, four to five stratified squamous cell layers, wing cells, and basal cells in the epithelium as well as flat-shaped keratocytes in the stroma were found on Day 0. By Day 7, stratified squamous cells and basal cells had decreased in number, and slightly round-shaped keratocytes were observed; however, the number of keratocytes was similar to that on Day 0. In this short-term ex vivo culture, epithelium and endothelium were sensitive to culture, whereas stroma and keratocytes were well maintained. An additional deswelling method will be needed to obtain more successful results in porcine corneal ex vivo culture.
        4,000원
        86.
        2015.03 구독 인증기관 무료, 개인회원 유료
        Antibiotics have been used to prevent disease, promote growth rate, and improve feed efficiency. However, the use of antibiotics in livestock has been restricted worldwide due to problems such as bacterial resistance. Therefore, probiotics among alternatives to antibiotics have gained attention in the livestock feed industry these days. This study was conducted to investigate the effects of dietary supplementation with probiotic 379D on safety, growth rate, and feed efficiency. In this study, bacterial strain 379D was isolated from soil and identified as a Bacillus sp. according to 16S rRNA sequence analysis. In an in vitro test, in-gel activity assay and antimicrobial susceptibility test were conducted to evaluate 379D. In an in vivo study, 379D was administered at concentrations of 0.1% and 1% to broiler chickens for 28 days. The results of in-gel activity assay and antimicrobial susceptibility test showed that strain 379D had broad spectrum antimicrobial activity. Furthermore, no adverse 379D-related effects were observed in 0.1% and 1% groups. Feed efficiency was higher in the 379D-treated groups than in the control group. In conclusion, 379D is expected to be used as a safe alternative to antibiotics in a feed supplement and will improve feed efficiency in broiler chickens.
        4,000원
        87.
        2014.06 구독 인증기관 무료, 개인회원 유료
        The current study was conducted to evaluate the biocompatibility of α-1,3 galactosyltransferase knockout pig bone graft in a rat calvarial defect model. Porcine cancellous bones were harvested from general and alpha-gal KO pigs and washed with 70% ethanol solution and normal saline. Bone pieces of the alpha-gal KO pig underwent a chemical treatment process to delipidize and deproteinize the bone. Bone graft particles were freeze-dried and stored at −70°C until use. Each bone graft was implanted into the rat calvarial defect in a fresh general pig, fresh transgenic pig, and chemical-treated pig bone group. There was no systemic adverse effect on hematology or necropsy findings in all groups at 1 week and 4 weeks. In the microcomputed tomography analysis, bone volume increased significantly in the chemical-treated transgenic pig bone group, whereas bone mineral density decreased significantly in the fresh general pig bone group compared with other groups. Histological evaluation showed cellular infiltration located at the margin of the bone graft particles, especially in the fresh general pig bone group. These results indicate that fresh general pig bone can elicit a greater local inflammatory response than fresh transgenic pig bone. Further, chemical-treated transgenic pig bone graft was less immunogenic than fresh bone graft. In conclusion, transgenic pig bone is a more biocompatible graft material. In addition, chemical treatment can reduce bone graft immunogenicity by delipidizing and deproteinizing bone.
        4,000원
        88.
        2014.03 구독 인증기관 무료, 개인회원 유료
        This study evaluated the possibility of clinical application using matrigel-based bioceramic/polymer scaffolds treated with bone morphogenetic protein, angiogenic factor, and mesenchymal stem cells (MSCs) for new bone formation. In the in vitro study, bone morphogenetic protein (BMP-2) and vascular endothelial growth factor (VEGF) containing matrigel, which is a basement membrane gel, was injected into HA/PCL scaffolds to estimate the release rates of growth factors. In the in vivo study, BMP-2, VEGF, and MSCs with matrigel-based scaffolds were implanted into rat femoral segmental defects, and new bone formation was evaluated at 4 and 8 weeks. In the results, the release rates of BMP-2 and VEGF explosively increased by day 5. For the in vivo study results, radiological evaluation revealed that the matrigel-based HA/PCL scaffolds with BMP-2 and VEGF grafted (M+B+V) and matrigel-based HA/PCL scaffolds with BMP-2, VEGF, and MSC grafted (MSC) groups showed increased bone volume and bone mineral density. Moreover, in the histological evaluation, large new bone formation was observed in the M+B+V group, and high cellularity in the scaffold was observed in the MSC group. In conclusion, grafted matrigel-based HA/PCL scaffolds with BMP-2, angiogenic factor, and MSCs increased new bone formation, and in clinical cases, it may be effective and useful to enhance healing of delayed fractures.
        4,000원
        89.
        2013.09 구독 인증기관 무료, 개인회원 유료
        In the livestock feed industry, antibiotics are used to prevent disease, promote growth rate, and improve feed efficiency. However, antibiotic supplementation to animal feed results in increased bacterial resistance to antibiotics as well as antibiotic residues in animal products, which can negatively affect human health. Therefore, alternative sources of antibiotics are need- ed. Probiotics as an alternative to antibiotics in animal feed have been shown to increase feed efficiency and growth rate by improving microbial balance. Further, Bacillus sp. produces a wide spectrum of antibacte- rial peptides. The present study was conducted to investigate the effects of dietary supplementation with CS-32 on safety, growth rate, and feed efficiency. Antibacterial substance (5697.9 molecular weights) produced by CS-32 was isolated and purified from culture broth. Moreover, the results of minimal inhibi- tory concentration (MIC) test confirmed the excellent antibacterial effect of CS-32. In vivo, 0.1% and 1% CS-32 were fed to broiler chickens for 28 days. Feed efficiency was slightly higher in groups of chickens supplemented with 0.1% and 1% CS-32 than those of the control group. CS-32 had no significant effect on necropsy findings, hematology, or serum biochemistry, and there was no mortality. These results suggest that CS-32 among various biologically active substances may be safe and effective as a feed additive to improve growth rate and feed efficiency.
        4,000원
        90.
        2013.06 구독 인증기관 무료, 개인회원 유료
        The current study was conducted in order to investigate bone formation using matrigel and angiogenic factors with HA and poly ε-caprolactone (HA/PCL) in a rat calvarial defect model. Calvarial defect formation was surgically created in Sprague Dawley rats (n=36). Rats in the control group (CD group, n=6) did not receive a graft. The HA/ PCL scaffold was grafted with matrigel (M-HA/PCL group, n=6) or without matrigel (HA/PCL group, n=6); and 100 ng of vascular endothelial growth factor with HA/ PCL scaffold containing matrigel (VEGF100 group, n=6), 100 ng (PDGF100 group, n=6) and 300 ng (PDGF300 group, n=6) of PDGF with HA/PCL scaffold containing matrigel were grafted in calvarial defects, respectively. Four weeks after surgery, bone formation was evaluated with micro computed tomography (micro CT) scanning, and histologically. According to the results, bone mineral density was significantly increased in the VEGF100, PDGF100, and PDGF300 groups compared to the HA/PCL group, in which angiogenic factors were not applied. In histological evaluation, more new bone formation around scaffolds was observed in the PDGF100 and the PDGF300 groups, compared with the VEGF100 group. Thus, the results indicate that HA/PCL containing matrigel with VEGF and PDGF is an effective grafting material for enhancement of bone formation in critical-sized bone defects. Especially, due to its price and capacity for bone formation, PDGF may be more effective than VEGF.
        4,000원
        91.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most patients with chronic low back pain experience functional disability of trunk muscle, and limitations in physical activity. While there are many types of exercise programs available, in recent years sling exercise has been emerging as the exercise program for spinal stabilization. It has been supported by a great amount of research with positive findings on its effectiveness. This research studies the effects of bridging exercise, conducted on a sling, on pain level and trunk muscle activation in supine, sidelying, and prone positions during a 4 weeks period. 10 healthy people(normal group, n=10) and 28 patients with low back pain participated in this study. 28 patients were divided into two groups; one group participated in exercise with the sling(experimental group, n=14) and the other group exercised without the sling(control group, n=14). They were asked to use the Numerical Rating Scale(NRS) to answer to the level of their pain they felt (no pain: 0 point, severe pain: 10 points). During sling bridging exercises, the muscle activity level in each muscle measured in each position was standardized as three seconds of EMG signals during five seconds MVIC. In conclusion, the experimental group with four weeks of sling bridging exercise experienced a statistically significant reduction in the pain level(p<.05) and increase in the muscle activities of erector spinae when in supine position, internal oblique when in sidelying position, and rectus abdominis in prone position(p<.05). Regular sling bridging exercise reduces the low back pain and enhances other trunk muscle activation, thereby positively affect spinal stabilization.
        4,000원
        92.
        2013.03 구독 인증기관 무료, 개인회원 유료
        This study was conducted in order to examine the effects of alcohol-free cetylpyridinium chloride drinking water additive and oral gel on clinical parameters related to periodontal disease in beagle dogs. This study was conducted with healthy 15 beagle dogs. Following a professional teeth cleaning procedure, dogs were divided into three groups. Dogs in the control group received nothing, those in the drinking water additive (DWA) group received 800 ml water with 15 ml of alcohol-free cetylpyridinium chloride drinking water additive daily, and those in the Oral gel (OG) group were treated with oral gel containing alcohol-free cetylpyridinium chloride and 0.05% chlorhexidine gluconate daily. Clinical parameters, including plaque index (PI), calculus index (CI), and gingivitis index (GI) were evaluated at two and four weeks. Dogs in the DWA and OG groups had significantly less plaque than dogs in the control group at two and four weeks (P<0.01, P<0.05). And, at four weeks, CI was significantly lower in the OG group compared to the control group (P<0.05). On GI, similar scores were recorded for all groups during the experimental period. No significant difference was observed between the DWA group and the OG group. The effect of alcohol-free cetylpyridinium chloride drinking water additive was similar to the result for alcohol containing cetylpyridinium chloride mouthwash reported in a previous study. The effect in control of periodontal disease was better in the OG group because of additional chlorhexidine gluconate. However, use of drinking water additive will be more convenient for owners; thus, it will be more effective for achievement of long-term results.
        4,000원
        93.
        2012.12 구독 인증기관 무료, 개인회원 유료
        Vital pulpotomy is a very useful method for disarming of canine tooth, tooth fracture, periodontitis, and malocclusion in veterinary dentistry. Calcium hydroxide is the material commonly used as a liner during vital pulpotomy. This creates a mineralized barrier by stimulating osteoblastic hard tissue repair, arrests the inflammatory response, and soothes dentin. However, the powder or mix type calcium hydroxide materials have many disadvantages due to complicated procedures for use and are hard to handle when vital pulpotomy is followed under general anesthesia in animals. This study was conducted in order to compare the effect of mix and premixed paste type calcium hydroxide as a liner in vital pulpotomy. Six beagle dogs underwent hemisection on the mesial root of the mandibular first molar and vital pulpotomy on the distal root of the first molar. On the distal root of the left and right mandibular first molar, mix type (DYCAL®, Dentsply, USA) and premixed paste type calcium hydroxide (VITAPEX®, Morita, Japan) were used as liners, respectively. Radiological evaluation was performed at immediate, 4, 12, and 20 weeks after vital pulpotomy. According to the results, all teeth had well-formed dentinal bridges, and there were no periradicular lucency, lamina dura loss, or anomalies of the pulp cavity. According to these results, on vital pulpotomy in animals, premixed paste type calcium hydroxide was easy to handle and decreased the anesthesia period due to a more convenient application procedure. A further study of many clinical cases is needed for evaluation of side effects and other problems.
        4,000원
        95.
        2012.09 구독 인증기관 무료, 개인회원 유료
        Probiotics, enzymes, organic acids, oligosaccharides, antioxidants, and other functional materials are actively being explored as alternatives to antibiotics. Probiotics include live beneficial microorganisms that colonize the intestinal tract and competitively inhibit attachment and growth of harmful microbes. Probiotics also increase feed efficiency by assisting in nutrient absorption and digestion. The current study was conducted in order to evaluate the effect of a new probiotic, CS-A, as a dietary supplement of a fermented product on growth performance, feed intake, and feed conversion efficiency in broiler chickens, and to evaluate its value as an alternative for antibiotics used as a feed additive. Antibacterial and anti-inflammatory effects of CS-A were investigated in vitro and the in vivo effects of a constant concentration of supplemented CS-A on growth rate and feed efficiency were evaluated. In addition, the safety of CS-A was assessed by examination of common symptoms and mortality. Determination of minimal inhibitory concentration revealed an excellent antibacterial effect of CS-A. Cytotoxicity was low and anti-inflammatory effects were achieved at the effective concentration of CS-A. Supplementation with 0.1% CS-A resulted in a feed efficiency score of 1.84 in broilers, compared to 2.00 in the control group. There were no adverse clinical findings, necropsy findings, hematology, and altered serum biochemistry parameters, and no mortality. Thus, it is concluded that CS-A is safe and effective as a feed additive.
        4,000원
        96.
        2012.06 구독 인증기관 무료, 개인회원 유료
        To identify subspecies and stocks of minke whale meats purchased from Korean markets during 2005-2007, we first obtained their complete sequences of mitochondrial DNA cytochrome b and control region sequences, and compared these sequences to the corresponding sequences of the common minke whale (Balaenoptera acutorostrata), obtained from GenBank. From analyses with partial cytochrome b sequences (383 bp) and non-coding, partial control region sequences (463 bp), Korean mink whale meats are identified as products from the North Pacific minke whale (B. a. scammoni). In addition, the sequences of the partial control region from these meats showed G at site no. 298 and G or A at site no. 463, and the meats appeared to originate from the J stock within this subspecies. Thus, because the J stock has been protected since 1986, implementation of strict regulation measures to reduce their accidental fisheries by catch seems urgent. In addition, B. a. scammoni is distinct from B. a. acutorostrata, with an average Jukes-Cantor distance of 2.21% in the complete control region sequence analysis (935 bp) and 1.31% in the complete cytochrome b gene sequence analysis; the current results support the current subspecies classification, although further sequencing analyses with nuclear genes are necessary.
        4,000원
        97.
        2012.06 구독 인증기관·개인회원 무료
        There are diverse methods of cryopreservation of mammalian embryos with variable degrees of success. Although cryopreservation technique of mammalian embryos has been advanced, freezing stress affect to cellular event such as apoptosis and autophage in embryos. The objective of the study is to investigate the affection of to survival, development, live offspring, apoptosis and autophagy on embryo. Mouse embryos were vitrified and thawed using normal straw and modified cut standard straw (M-CSS), then in vitro cultured until blastocyst stage and transferred to recipient. Recovery rates (100 vs 99.2%), survival rates (99.2 vs 78.6%), developmental rates (18.4 vs 10.7%), total cell numbers (45 vs 37), preganacy rates (34.5 vs 25%) and offspring numbers (10.1 vs 4.9 %) of M-CSS group are significantly higher than those of normal straw vitrified group. Also, rate of apoptosis in blastocysts developed using M-CSS (1.9%) was significantly lower than using normal straw vitrification (2.7%). Apoptosis-related gene, caspase 3, was expressed at the highest level in blastocysts derived from normal straw group. However, no differences of autophagy related gene, Atg6 and expression of LC3 between normal straw and M-CSS groups were observed. In conclusion, the standard vitrification procedure induces mitochondrial apoptosis in zygotes in an autophagy-independent manner, whereas the novel M-CSS procedure may improve embryo vitrification.
        99.
        2021.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The auroral observation has been started at Jang Bogo Station (JBS), Antarctica by using a visible All-sky camera (v-ASC) in 2018 to routinely monitor the aurora in association with the simultaneous observations of the ionosphere, thermosphere and magnetosphere at the station. In this article, the auroral observations are introduced with the analysis procedure to recognize the aurora from the v-ASC image data and to compute the auroral occurrences and the initial results on their spatial and temporal distributions are presented. The auroral occurrences are mostly confined to the northern horizon in the evening sector and extend to the zenith from the northwest to cover almost the entire sky disk over JBS at around 08 MLT (magnetic local time; 03 LT) and then retract to the northeast in the morning sector. At near the magnetic local noon, the occurrences are horizontally distributed in the northern sky disk, which shows the auroral occurrences in the cusp region. The results of the auroral occurrences indicate that JBS is located most of the time in the polar cap near the poleward boundary of the auroral oval in the nightside and approaches closer to the oval in the morning sector. At around 08 MLT (03 LT), JBS is located within the auroral oval and then moves away from it, finally being located in the cusp region at the magnetic local noon, which indicates that the location of JBS turns out to be ideal to investigate the variabilities of the poleward boundary of the auroral oval from long-term observations of the auroral occurrences. The future plan for the ground auroral observations near JBS is presented.
        100.
        2017.05 서비스 종료(열람 제한)
        Background : Methicillin-Resistant Staphylococcus aureus (MRSA) is a multidrug-resistant (MDR) strain. Especially, MRSA is developing resistance to available antibacterial agents and causing complications in the treatment of infections related to skin, soft tissue, respiratory, bone, joint, and endovascular disorders. Therefore, antibacterial agent combination therapy appears to be a useful option, particularly in developing countries where antibiotic availability is limited. (+)-Usnic acid (UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. Methods and Results : In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against MRSA. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid (EDTA) was used. In the other hand, Sodium azide (NaN3) was used as inhibitors of ATPase. These results suggest that the antibacterial effect of UA was potentiated by membrane-binding agents and ABC transporter-inhibiting agents, implying that antibacterial activity is associated with damage of the cell wall and inhibition of ATPase function by UA. Conclusion : UA and in combination with EDTA and NaN3 could lead to the development of new combination antibiotics against MRSA infection. The results of this study appear to be promising, and they are expected to enhance the use of natural products as drugs.
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