• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.18-28
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• 2005

Purpose: The purpose of this study is to evaluate the clinical, radiological and histopathological results after microfracture surgery for degenerative arthritis of the knee. Materials and Methods: From Oct. 1997 to Dec. 1998, 48 knees in 46 patients were treated by microfracture technique. Their mean age at the time of operation was 56 years(range, 40-75 years) and mean period of follow-up study was one year(range, 7-20 months). For 24 knees in 22 patients, 'second-look' arthroscopies and biopsies were performed at 6 months following microfracture. At the last follow up clinical results were evaluated with Baumgaertner's scale. The specimens of 24 cases were stained with H-E, Safranin-O, and Masson's trichrome. Eighteen of 24 cases were stained immunohistochemically and the Western blotting test was performed on 12 cases for type II collagen. We analyzed the relationship of the Western blotting for type II collagen with clinical score, preoperative varus deformity, joint space widening in radiological result, extent of repaired articular cartilage in '2nd-look' arthroscopic findings, patient's age and weight. Results: Clinical results were excellent in 90% and good in 10%. Among the 24 knees, more than 80% of areas of chondral defect were covered with regenerated cartilage in 21 knees Histologically, the repaired tissue appears to be a hybrid of hyaline cartilage and fibrocartilage. Repaired cartilage contains variable amounts of type II collagen with immunohistochemical staining. The results of the Western blotting test were similar. The amounts of type II collagen formation had positive correlation with the extent of repaired cartilage and preoperative varus deformity. Conclusion: 'Second-look' showed that the chondral defect areas were covered with newly grown grayish white tissue. Articular cartilage repair was confirmed with histological and immunohisto-chemical study qualitatively, and the amount of type II collagen was calculated with the Western blotting test quantitatively. The exact nature and fate of repaired cartilagenous tissues need further long term follow-up study. The results of this study provide the rationale to select osteoarthritic patients indicated for microfracture surgery.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.652-662
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• 2010

The purpose of this experiment was to study the effects of demineralized bone matrix (DBM), calcium sulfate (CS), and calcium metaphosphate (CMP) on osteogenesis of unicortical 5-mm-diameter defects in canine femurs. Seventy-two femoral unicortical defects of nine adult beagles (eighteen femurs, four unicortical femoral defects were made in each femur) were made. Three bone graft substitutive materials such as CS, DBM, and CMP and the empty controls were compared each other. The postimplanted specimens were harvested at week 4, 8, and 24 for radiographic, biochemical and histomorphologic evaluation. In radiograph, CS group appeared to be absorbed rapidly and made new cortical bone. Defects of cortical bone was gradually filled with new bone around bone graft materials in DBM group. Bone graft substitutes weren't absorbed rapidly but, remained performing structural roles in cortical bone after 24 weeks in CMP group. Radiographic intensity of control group showed significantly (p < 0.05) lower compared to that of experimental group. Defects treated with either CS, DBM or CMP had more bone formation than the untreated defects (p < 0.05). The results of analysis in the cortical bone region were deduced the conclusions as follows. Three bone graft materials seemed to accelerate the formation of new bone compared with controls for 24 weeks. CMP group having more or less large particle space was more adequate than DBM group, as well as more compact CS group was more pertinent than CMP group as the glues for bones.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.486-491
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• 2005

Physical activity can improve sensorimotor recovery after peripheral nerve injury. Growth-associated protein 43 (GAP-43) is highly correlated with neuronal development and axonal regeneration and present in large quantities in the axonal growth cone. Using immunofluorescene staining and anterograde and retorgrade techniques, we identified enhanced axonal regrowth in distal stump of the sciatic nerve 3-14 days after crush injury in rats with treadmill training. We also carried out western blot to investigate GAP-43 protein expression in injured sciatic nerve. GAP-43 protein levels were highly induced in the injured sciatic nerve 3, 7 and 14 days compared with sedentary group. Thus, the present data provide a new evidence that treadmill training promoted axonal re-growth after injury and increased GAP-43 protein levels in the regenerating nerve.

• Journal of Life Science
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• v.19 no.8
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• pp.1067-1072
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• 2009

Stromal derived factor-1 (SDF-1 or CXCL12), one of the CXC chemokines, is widely expressed in many tissues, including the thymus. The thymus can regenerate to its normal mass within 14 days after acute involution induced by cyclophosphamide (CY) in adult rats. Despite the established role of SDF-1 signaling in the development of T and B lymphocytes in the thymus, it has not yet been associated with the regeneration of the adult thymus. The purpose of this study was to investigate whether SDF-1, which is expressed in thymic stromal cells, is modulated during thymic regeneration in adult rats. Here, we showed that SDF-1 mRNAs were expressed in high levels in the thymocyte and thymic stromal cells at day 7 of the CY model. SDF-1 protein was shown to be present at the cortex-medulla junction, paraseptum and within the thymic medulla. Double-immunofluorescence for SDF-1 and ED-1 showed that strong SDF-1 expression was detected in the macrophages of the medulla region displaying immunoreactivity for ED-1 during thymus regeneration. Taken together, our results demonstrated that SDF-1 expression increased in regenerating thymic macrophages, suggesting the roles of SDF-1 as a chemo-attractant for damaged cells produced in the process of thymic regeneration after acute involution induced by CY.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.61-65
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• 2018

Our experiment studied that grafted stem cells reduced behavioral deficiency in rodent animal models of clip compressive surgery inducing spinal cord infarction. Our research proved the effect of embryonic stem cells to the spinal cord infarction caused by compressing T9-10 with an aneurysm clip, focusing the application of grafted stem cells for reduction of infarction and regeneration of spinal cord nervous injury. Therefore, our research suggests manifest results that implantation of mouse embryonic stem cell could show behavioral improvement after severe spinal cord damage. Therefore, mouse embryonic stem cell (mESC) could be useful application for the method in neurological injury. Conclusively, stem cell implant therapy may enhance the effectiveness of stem cell implant for central nervous system injury.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 1999.07a
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• pp.47-55
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• 1999

고온온열치료는 radiofrequency, ultrasound , microwave, 원적외선 등을 이용하여 신체의 부분 혹은 전신을 4$0^{\circ}C$ 이상으로 가열하여 암을 치료하는 방법이다. 우리나라에 도 입된 15기의 기계중 현재까지 사용되고 있는 것은 대부분이 radiofrequency를 사용하는 기 계이며 현재 고신의대, 동아의대, 부산메리놀병원, 여의도 성모병원, 영남의대, 전주예수병원 등에서 환자치료에 사용하고 있다. 고온 온열치료제(hyperthermia)는 직접 암세포를 죽이는 작용, 방사선치료나 항암제치료와 병행하여 그 효과를 증강시키는 작용으로 크게 나눌수 있 다. 직접 암세포를 죽이기 위하여는 43$^{\circ}C$이상의 고온을 사용하여야 하나 인체에서는 42.5$^{\circ}C$ 이상으로 가온하기가 쉽지않아 4$0^{\circ}C$~42$^{\circ}C$ 정도의 온도에서 방사선 치료나 항암제 치료효과 를 증진시키는 작용을 임상에서 주로 사용하고 있다. 특히 방사선 치료와 병합 사용시 그 효과가 뛰어나 간암, 난소암, 대장 직장암, 식도암, 위암, 자궁암, 전립선안, 췌장암, 폐암등, 거의 모든 암에서 부작용을 증가시키지 않으면서 그 효율을 1.1-6.14배나 증가시킨다고 보 고되고 있어 지난 10여 년간 제자리걸음을 하고 있는 암의 치료에 희망을 주고 있다. 방사 선 치료와 병합시 효과를 증대시키는 기전은 1)세포의 핵 합성기 (S-phase)는 방사선 치료 에는 매우 저항력이 강하여 잘 죽지 않으나 고온온열치료에는 예민함으로 암세포는 정상조 직에 비해 산소가 부족하여 염기성대사(anaerobic metabolism)를 많이 함으로 그 부산물인 유산 (lactic acid)이 많이 생성됨으로 정상조직보다 pH가 낮아 암 조직이 정상조직에 비해 고온온열치료에 더 잘 듣는 원인이 된다. 3) 영양이 부족한 상태의 세포는 고온온열치료에 훨씬 예민하다. 4) 암조직은 혈관상태가 정상조직에 비해 좋지 않음으로 정상조직보다 쉽게 가온이 되며, 일단 가온된 온도는 잘 식지 않음으로 정상조직에 비해 훨씬 효율적이다. 5)고 온온열치료는 4$0^{\circ}C$~43.5 $^{\circ}C$정도에서만 이 작용이 일어남으로 정상인체에서 43$^{\circ}C$이상의 가온 은 쉽지 않음으로 이 효과는 암조직에서 주고 일어나게 된다. 6)고온온열치료는 방사선치료 후에 생기는 손상의 재생을 억제함으로 방사선의 치료효과를 높인다. 7)38.5$^{\circ}C$~41.5$^{\circ}C$의 낮 은 온도에서도 암조직의 산소 상태를 호전시켜 방사선 치료효과를 증대시키는 역할을 한다.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.779-797
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• 1996

The present study investigated the effects of variations in decalcification time of demineralized freeze-dried bone on the osteogenic potential of DFDB. Sixteen 3-wall intrabony defects with 4mm depth were surgically created in the mesial aspect of upper and lower anterior teeth of 4 dogs. Following the flap procedure, three test groups with 4 defects each received either freeze-dried bone graft (Group I), demineralized freeze-dried bone graft decalcified for 12hours (Group II), or demineralized freeze-dried bone graft decalcified for 24hours(Group III). The rest of the four defects received the flap procedure-only as the control group. The healing was histologically analyzed after 14 weeks on the length of connective tissue adhesion, new bone formation and new cementum formation. The results were as follows: 1. The length of connective tissue adhesion showed no statistically significant difference in all groups with $0.62{\pm}0.14mm$ for Control, $0.42{\pm}0.11mm$ for Group I, $0.63{\pm}0.43mm$ for Group II and $0.52{\pm}0.11mm$ for Group III. 2. The new bone formation showed no statistically significant difference in all groups with $3.17{\pm}0.24mm$ for Control. $3.15{\pm}0.56mm$ for Group I. $3.22{\pm}0.36mm$ for Group II, and $3.28{\pm}0.74mm$ for Group III. 3. The new cementum formation showed no statistically significant difference in all groups with $4.19{\pm}0.46mm$ for Control, $3.23{\pm}0.64mm$ for Group I, $4.13{\pm}1.82mm$ for Group II. and $3.13{\pm}0.62mm$ for Group III.

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.455-466
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• 2002

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.18 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.356-358
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• 2003

The use of cultured epidermal sheet grafts for large full-thickness wound has been tempered by weak points such as long culture periods, difficulty in handling the fragile sheets, high costs and the detachment of the skin cells from the culture dishes by enzymatic digestion. To overcome the drawback of epidermal sheet grafts, we have developed a transplantation method to spray the cultured human keratinocytes with the mixtures of rhEGF and fibrin gel matrix to the full-thickness wounds on the dorsum of the athymic mice to regenerate epithelial layers. Wound biopsies were retrieved at 7, 14 and 21 days after transplantation and retrieved biopsies were analyzed by histology and immunohistochemistry. Transplanted keratinocytes and EGF-fibriin gel accelerated wound regeneration compared with control groups. The technique developed in this study overcomes the drawbacks of the current cultured epidermal sheet grafts and accelerates epidermal wound healing.

• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.59-63
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• 1999

Efficient plant regeneration via shoot organogenesis from in vitro cultured leaf segments of chrysanthemum (Dendranthema grandiflora Tzvelev cv. Namjeon) was achieved. Adventitious shoot formation from leaf explants was greatly influenced by plant growth regulator, leaf age, light condition, explant number per culture vessel, and explant orientation. Leaf segments, obtained from fully expanded young 1-2nd leaves and inoculated 8 explants per petri-dish with adaxial surface contact with MS medium supplemented with 0.5 mg/L BA and 2.0 mg/L NAA, produced 100% regeneration frequency and 13.7 shoots per explant. Regenerated adventitious shoots were successfully rooted in MS medium with 0.1 mg/L NAA. The plantlets were acclimatized in artificial soil mixtures (Vermiculite:Perlite=1:1), and transferred to greenhouse for flowering. The regenerated plants showed normal phenotypes.