• Journal of Chest Surgery
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• v.15 no.2
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• pp.139-147
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• 1982

In case of segmental injury of trachea, the primary repair is very difficult, because the trachea is fixed in place without movability from the surrounding tissue. In addition to special anatomical situation of trachea, any ideal artificial prosthesis for tracheal replacement is not still appeared. Many authors proposed several procedures for the tracheal repair, but satisfactory results were few. Among the proposed procedures end to end anastomosis of trachea was noted superior when both ends of trachea could be approximated by mobilization of upper and lower injured trachea. The author's experiment was designed to determine the effect about decreased tension on trachea when the hyoid bone was released downward from the surrounding muscular structures. The experimental dogs were divided into two groups, suprahyoid releasing group (SH R) and control group of intact hyoid. SH R group was subdivided into two groups accord ing to he degree of tension. The experimental results were as follow; 1. SH R group: In view of X-ray, the distance between the angle of mandible and the displaced hyoid bone was lengthened downward. And it's range was from 1.3cm (38%) minimally to 2.7cm(108%) maximally. 2. Control group: The distance between the angle of mandible and hyoid was same in both pre and postoperation. As the result of this experiment study, the suprahyoid release technique seems to be the efficient method that enable of release the trachea maximally. And it should be expected that the SH R technique is applicable clinically.

• Reproductive and Developmental Biology
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• v.32 no.1
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• pp.21-25
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• 2008

Bone marrow mesenchymal stem cells (BMMSCs) have the capacity for self-renewal and differentiation into a variety of cell types. They represent an attractive source of cells for gene and cell therapy. The purpose of this study is to direct the specific expression of the DsRed reporter gene in $Sca-1^+$ BMMSCs differentiated into a cardiomyogenic lineage. We constructed the prMLC-2v-DsRed vector expressing DsRed under the control of the 309 tp fragment of the rat MLC-2v 5'-flanking region. The specific expression of the DsRed reporter gene under the transcriptional control of the 309 bp fragment of the rat MLC-2v promoter was tested in 5-azacytidine healed-$Sca-1^+$ BMMSCs over 2 weeks after the prMLC-2v-DsRed transfection. The prMLC-2v-DsRed was specifically expressed in the $Sca-1^+$ BMMSCs with cardiomyogenic lineage differentiation and it demonstrates that the 309 bp sequences of the rat MLC-2v 5'-flanking region is sufficient to confer cardiac specific expression on a DsRed reporter gene. The cardiac-specific promoter-driven reporter vector provides an important tool for the study of stem cell differentiation and cell replacement therapy in ischemic cardiomyopathy.

• The korean journal of orthodontics
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• v.44 no.4
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• pp.217-225
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• 2014

Single-tooth implantation has become a common treatment solution for replacement of a root-fractured maxillary incisor in adults, but the long-term esthetic results can be unfavorable due to progressive marginal bone loss, resulting in gingival recession. In this case report, a maxillary central incisor with a root fracture in its apical one-third was orthodontically extruded and extracted in a 21-year-old female. Implant surgery was performed after a 3-month healing period, and the final crown was placed about 12 months after extraction. After 12 years, favorable osseous and gingival architectures were visible with adequate bone height and thickness at the buccal cortical plate, and no gingival recession was seen around the implant-supported crown. Although modern dentistry has been shifting toward simplified, clinical procedures and shorter treatment times, both general dentists and orthodontists should be aware of the possible long-term esthetic advantages of orthodontic extrusion of hopelessly fractured teeth for highly esthetically demanding areas and should educate and motivate patients regarding the choice of this treatment solution, if necessary.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.2
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• pp.131-139
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• 2005

The therapeutic goal of implant dentistry is not merely tooth replacement but total oral rehabilitation. Considering dental implants as a treatment option can be provided patients with positive, long-term results. Implant dentistry has gone through many phases over the years. Modern technology and design allows us to predictably place our dental implants often load the implants at the time of placement. The purpose of this study is to evaluate the implant stability after immediate loading in dogs. The control group was performed delay loading and experimental group was immediate loading. Each group was measured periotest value(PTV) to evaluate clinical mobility and performed radiographic examination to evaluate marginal bone loss. Statistically significant difference was not founded in control group between experimental group in PTV(P>0.05) and marginal bone loss(P>0.05). Finally, implant stability after immediate loading was similar to delay loading implant.

• Journal of Biomedical Engineering Research
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• v.14 no.2
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• pp.155-162
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• 1993

The human's biomechanical structure keeps an optimal state by adapting the original biomechanical structure according to a change in the physical environment. This phenomenon is believed to be the main cause of loosening of the total hip replacement which is used widely in these days. In this study the bone density change due to artificial hip joint, which is generally believed as bone-remodeling, was investigated by the finite element method. For this, 2-D FEM models with 4 nodal point elements were constructed for intact and implanted cases. The density was calculated by comparing the relative amounts of effective stress for these two cases. In this way, calculated new density values were used in the next step as input values and this procedure repeated until convergence was obtained. Severe density change was detected at the femoral cortex of the proximal-medial side as expected. Moreover, following surprising result was found from this analysis. Titanium alloy prosthesis showed less density change compared to stainless steel prosthesis at earlier stage, however, almost same amount of the density change was detected at final stage. It was also found that other design parameters could not significantly affect its density change.

• Childhood Kidney Diseases
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• v.25 no.2
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• pp.117-121
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• 2021

Chronic kidney disease (CKD)-mineral and bone disorder (CKD-MBD) is a common complication of CKD, often accompanied by extra-skeletal calcification in adult patients. As increased vascular calcification is predicted to increase cardiovascular mortality and morbidity, the revised Kidney Disease: Improving Global Outcomes guidelines recommend avoiding calcium-containing phosphate chelators. However, extra-skeletal calcification is less commonly noticed in pediatric patients. Here, we report our experience of such a complication in pediatric patients receiving maintenance peritoneal dialysis. Extra-skeletal calcification was noticed at the corneas, pelvic cavity, and soft tissues of the lower leg in 4 out of 32 patients on maintenance peritoneal dialysis. These patients experienced the aggravation of extra-skeletal calcifications during peritoneal dialysis, and 2 of them underwent excisional operations. It is required to monitor extra-skeletal calcifications in children on kidney replacement therapy.

• Structural Engineering and Mechanics
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• v.88 no.6
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• pp.583-588
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• 2023

Total hip replacement is a crucial intervention for patients with fractured hips who face challenges in natural recovery. The design of durable prostheses requires a comprehensive understanding of the natural processes occurring in bone. This article focuses on static loading analysis, specifically during stumbling activity, aiming to enhance the longevity of prosthetic implants. Three distinct implants, Charnley, Osteal, and Thompson, were selected for a detailed study to determine the most appropriate model. The results revealed critical insights into the distribution of Von Mises stresses on the components of femoral arthroplasty, including the cement, implant, and cortical bone. Furthermore, the examination of shear stress within the cement emerged as a pivotal aspect for all three implants, playing a crucial role in evaluating the performance and durability of hip prostheses. The conclusions drawn from this study strongly suggest that the Thompson model stands out as the most suitable choice for hip joint implants.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Journal of Veterinary Clinics
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• v.37 no.3
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• pp.157-162
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• 2020

A 6-year-old Thoroughbred mare presented to the Korea Racing Authority Equine Hospital with dropping of the left front fetlock due to an injury sustained while racing. Radiographic examination revealed a comminuted fracture of both proximal sesamoid bones of the affected fetlock. Arthrodesis of the fetlock joint using a broad dynamic compression plate with a tension band wire was performed as a salvage procedure for the future use as a broodmare. After surgery, however, a delayed union of the bones and surgical site infection was present for a prolonged period. Staphylococcus aureus was persistently identified from the surgical site, and antimicrobial therapies were based on antibiotic sensitivity tests, including regional perfusions. The removal and replacement of surgical implants associated with seropurulent discharge was based on coordinating the development of fetlock ankylosis and infection control over 13 months. Firstly, seven screws associated with surgical drainage were replaced and bone morphogenetic protein-2 (BMP-2) and local antibiotics were placed into the surgical site to accelerate bone fusion at postoperative month 7. Further six screws, along with drainage, were removed at postoperative month 10. The plate and screws were removed from the limb due to the progression of bone fusion at postoperative month 13; BMP-2 and local antibiotics were also used. Delayed healing of arthrodesis due to surgical site infection and implant instability were treated by implant removals and antibiotic therapies, and the horse eventually showed improved weight-bearing ability of the affected limb.

• Archives of Reconstructive Microsurgery
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• v.2 no.1
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• pp.29-41
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• 1993

Recent advances in microsurgery have made it possible to provide a continued circulation of blood to the grafted bone so as to ensure viability. With the nutrient blood supply preserved, healing of the graft to the recipient bone is facilitated without the usual replacement of the graft by creeping substitution. We reviewed 34 cases of vascularized osteocutaneous fibular transfers to the infected tibial defect complicated with skin defect, which were performed from May, 1982 to January, 1992, and the following results were obtained: 1. Despite of uncontrolled bone infection with skin defect, the vascularized osteocutaneous fibular flap transfer could be performed. 2. In the vascularized osteocutaneous fibula transfer, the patency of anastomoses could be indirectly monitored by observing the color of the skin flap. 3. The vascularized fibula had been hypertrophied with bony union during the follow-up period of 13 months to 6 years and 4 months(average, 30 months) and there was no resorption of the grafted fibula. 4. There was no fracture of the grafted fibula in parti resection of involved tibia. 5. The hypertrophic potentiality of grafted fibula could be inhibited by the infection status as operation site.