• Journal of Periodontal and Implant Science
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• v.44 no.3
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• pp.147-155
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• 2014

Purpose: In the anterior maxilla, hard and soft tissue augmentations are sometimes required to meet esthetic and functional demands. In such cases, primary soft tissue closure after bone grafting procedures is indispensable for a successful outcome. This report describes a simple method for soft tissue coverage of a guided bone regeneration (GBR) site using the double-rotated palatal subepithelial connective tissue graft (RPSCTG) technique for a maxillary anterior defect. Methods: We present a 60-year-old man with a defect in the anterior maxilla requiring hard and soft tissue augmentations. The bone graft materials were filled above the alveolar defect and a titanium-reinforced nonresorbable membrane was placed to cover the graft materials. We used the RPSCTG technique to achieve primary soft tissue closure over the graft materials and the barrier membrane. Additional soft tissue augmentation using a contralateral RPSCTG and membrane removal were simultaneously performed 7 weeks after the stage 1 surgery to establish more abundant soft tissue architecture. Results: Flap necrosis occurred after the stage 1 surgery. Signs of infection or suppuration were not observed in the donor or recipient sites after the stage 2 surgery. These procedures enhanced the alveolar ridge volume, increased the amount of keratinized tissue, and improved the esthetic profile for restorative treatment. Conclusions: The use of RPSCTG could assist the soft tissue closure of the GBR sites because it provides sufficient soft tissue thickness, an ample vascular supply, protection of anatomical structures, and patient comfort. The treatment outcome was acceptable, despite membrane exposure, and the RPSCTG allowed for vitalization and harmonization with the recipient tissue.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.232-236
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• 2004

In order to optimize tissue culture conditions for genetic transformation of orchardgrass (Dactylis glomerata L.), the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of a cultivar, 'Roughrider', as explant tissues. The optimal concentration of 2,4-D for the induction of embryogenic callus from mature seeds was 3 mg/L. Plant regeneration frequency was 36.3% when embryogenic calli were cultured on the regeneration medium supplemented with 1mg/L 2,4-D and 3mg/L BA. Addition of 1 g/L casein hydrolysate and 300 mg/L L-proline improved frequencies of embryogenic callus induction and plant regeneration up to 57.3 and 60.7%, respectively. Supplementation of the media with 10 mga $\textrm{AgNO}_3$ and 40 mg/L cysteine enhanced frequencies of callus induction and plant regeneration. Efficient regeneration system established in this study will be useful for molecular breeding of orchardgrass through genetic transformation.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.539-546
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• 2014

PURPOSE. Silk fibroin (SF) is a new degradable barrier membrane for guided bone regeneration (GBR) that can reduce the risk of pathogen transmission and the high costs associated with the use of collagen membranes. This study compared the efficacy of SF membranes on GBR with collagen membranes (Bio-$Gide^{(R)}$) using a rat calvarial defect model. MATERIALS AND METHODS. Thirty-six male Sprague Dawley rats with two 5 mm-sized circular defects in the calvarial bone were prepared (n=72). The study groups were divided into a control group (no membrane) and two experimental groups (SF membrane and Bio-$Gide^{(R)}$). Each group of 24 samples was subdivided at 2, 4, and 8 weeks after implantation. New bone formation was evaluated using microcomputerized tomography and histological examination. RESULTS. Bone regeneration was observed in the SF and Bio-$Gide^{(R)}$-treated groups to a greater extent than in the control group (mean volume of new bone was $5.49{\pm}1.48mm^3$ at 8 weeks). There were different patterns of bone regeneration between the SF membrane and the Bio-$Gide^{(R)}$ samples. However, the absolute volume of new bone in the SF membrane-treated group was not significantly different from that in the collagen membrane-treated group at 8 weeks ($8.75{\pm}0.80$ vs. $8.47{\pm}0.75mm^3$, respectively, P=.592). CONCLUSION. SF membranes successfully enhanced comparable volumes of bone regeneration in calvarial bone defects compared with collagen membranes. Considering the lower cost and lesser risk of infectious transmission from animal tissue, SF membranes are a viable alternative to collagen membranes for GBR.

• Korean Journal of Plant Resources
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• v.28 no.3
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• pp.363-369
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• 2015

Sweet potato has low regeneration capacity, which is a serious obstacle for the fruitful production of transgenic plants. Simple and rapid regeneration method from storage root explants of purple sweet potato (Ipomoea batatas L.) was investigated. The embryogenic callus was observed from 4 cultivars and its highest rate was induced at 1 μM 2,4-D after 5 weeks of culture. Result revealed that a low concentration of 2,4-D and low light intensity was important factors for embryogenic callus formation. After subculture on medium with 5 μM ABA for 4 days, subsequently, occurred the regeneration of shoots within 4 weeks when these embryogenic callus was transferred onto the MS hormone free medium. Regenerated shoots were developed into platelets, and grown normal plants in the greenhouse. We developed a simple and quickly protocol to regenerate plantlets in storage root explants of purple sweet potato. This regeneration system will facilitate tissue culture and gene transfer research of purple sweet potato.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.171-177
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• 2008

This paper reports an improved protocol for isolation, culture and regeneration of Lotus corniculatus protoplasts. A range of parameters which influence the isolation of L. corniculatus protoplasts were investigated, i.e., enzyme combination, tissue type, incubation period and osmolarity level. Of three enzyme combinations tested, the highest yield of viable protoplasts was achieved with the combination of 2% Cellulase Onozuka RS, 1% Macerozyme R-10, 0.5% Driselase and 0.2% Pectolyase. The use of etiolated cotyledon tissue as a source for protoplast isolation proved vital in obtaining substantially higher protoplast yields than previously reported. Culture of the protoplasts on a nitrocellulose membrane with a Lolium perenne feeder-layer on the sequential series of PEL medium was highly successful in the formation of microcolonies with plating efficiencies 3-10 times greater than previous studies. Shoot regeneration and intact plants were achieved from 46% of protoplast-derived cell colonies.

• Macromolecular Research
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• v.14 no.1
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• pp.94-100
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• 2006

Although the peripheral nerve system has a relatively good regenerating capacity compared to the central nerve system, peripheral nerve repair remains a clinical challenge as restoration of normal nerve function is highly variable. Synthetic tubular nerve conduits were designed as an alternative repair method in order to replace the need for an isograft. These nerve conduits guide regenerating axons from the proximal toward the distal end, maintain within growth-promoting molecules released by the nerve stumps, and protect regenerating axons from infiltrating scar tissue. In this work, we prepared cinnamoylated alginate (CA)-collagen-chitosan nerve conduit using the lyophilization method to generate a controllable parallel channel in the center and then investigated its influence on peripheral nerve regeneration in an animal study. At 12 weeks after implantation, histological study showed that tissue cable was continuously bridging the gap of the sciatic nerve in all rats. Our newly developed nerve conduit is a promising tool for use in peripheral nerve regeneration and provides a suitable experimental model for future clinical application.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.761-762
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• 2003

Recently, several studies have reported on the successful repair of osteochondral defects by transplantation of cultured chondrocytes, but the method requires a sufficient number of cells obtained from the donor site in the articular cartilage. This can potentially be overcome by the use of undifferentiated or partially developed cartilage precursor cells drived from early embryos and fetal tissue. Neonatal cartilage unlike adult cartilage has the capacity for rapid regeneration. the purpose of this study is to determine effective regeneration method using early cartilage precursors for tissue-engineered cartilage. Cells isolated from neonatal (immediately postpartum, 2 hours of age) SD rats were seeded onto biodegradable polymer matrices and transplanted in nude mice's subcutaneous sites for 4 and 8 weeks. Tissue-engineered cartilage showed gross and histologic evidences similar to native articular cartilage.

• Archives of Plastic Surgery
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• v.41 no.3
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• pp.231-240
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• 2014

Cartilage has a limited regenerative capacity. Faced with the clinical challenge of reconstruction of cartilage defects, the field of cartilage engineering has evolved. This article reviews current concepts and strategies in cartilage engineering with an emphasis on the application of nanotechnology in the production of biomimetic cartilage regenerative scaffolds. The structural architecture and composition of the cartilage extracellular matrix and the evolution of tissue engineering concepts and scaffold technology over the last two decades are outlined. Current advances in biomimetic techniques to produce nanoscaled fibrous scaffolds, together with innovative methods to improve scaffold biofunctionality with bioactive cues are highlighted. To date, the majority of research into cartilage regeneration has been focused on articular cartilage due to the high prevalence of large joint osteoarthritis in an increasingly aging population. Nevertheless, the principles and advances are applicable to cartilage engineering for plastic and reconstructive surgery.

• Molecules and Cells
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• v.47 no.2
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• pp.100010.1-100010.12
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• 2024

Recently, the incidence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing due to the high prevalence of metabolic conditions, such as obesity and type 2 diabetes mellitus. Steatotic liver is a hotspot for cancer metastasis in MASLD. Altered lipid metabolism, a hallmark of MASLD, remodels the tissue microenvironment, making it conducive to the growth of metastatic liver cancer. Tumors exacerbate the dysregulation of hepatic metabolism by releasing extracellular vesicles and particles into the liver. Altered lipid metabolism influences the proliferation, differentiation, and functions of immune cells, contributing to the formation of an immunosuppressive and metastasis-prone liver microenvironment in MASLD. This review discusses the mechanisms by which the steatotic liver promotes liver metastasis progression, focusing on its role in fostering an immunosuppressive microenvironment in MASLD. Furthermore, this review highlights lipid metabolism manipulation strategies for the therapeutic management of metastatic liver cancer.

• Journal of Periodontal and Implant Science
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• v.26 no.3
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• pp.735-751
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• 1996

An ultimate goal of periodontal therapy is to stop the disease process and to regenerate a functionally-oriented periodontium destroyed as a result of periodontal disease. The purpose of this study was to observe the effect of grafting granulation tissue obtained from extraction socket on the regeneration of horizontal furcation defect. Six dogs were used in this study. All mandibular first and third premolars were extracted. At 2, 3, and 5 days after extraction, tissues were obtained from extraction socket of 1 mongrel dog and examined by light microscope. Granulation tissue obtained at 5 days after extraction was chosen as the graft material. Five days later, horizontal furcation defects were created surgically at mandibular second and fourth premolars in the right and left side of the 5 beagle dogs. The entrance area of the artificially prepared "key hole" defects were about $3\;4mm^2$. By random selections, 2 exposed furcation defects were grafted with granulation tissue obtained from extraction socket as experimental group and 1 furcation defect was as control. The flaps were replaced to their original position and sutured with 4-0 chromic cat-gut. Three dogs were sacrificed 4 weeks and two dogs 8 weeks after surgery, and the prepared specimens were examined by light microscope. At 4 weeks, furcations were filled with epithelial lining and fibrous connective tissue infiltrated with chronic inflammatory cells. New bone formation was observed in all groups. Only experimental group showed new cementum formation. At 8 weeks, new cementum, functional arrangement of new PDL fiber, root resorption, and some ankylotic union of newly formed alveolar bone and root surface were observed in all groups. Experimental group showed that epithelial downgrowth was inhibited and new bone formation was more active compared to control. The success rate of the furcation defect healing was higher in experimental group than control. These results suggested that grafting of granulation tissue obtained from extraction socket which combined with reconstructive periodontal flap surgery may promote periodontal regeneration of horizontal furcation defect.