• Journal of Korean Neurosurgical Society
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• v.54 no.6
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• pp.461-466
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• 2013

Objective : Although curcumin has a protective effect on bone remodeling, appropriate therapeutic concentrations of curcumin are not well known as therapeutic drugs for osteoporosis. The purpose of this study was to compare the bone sparing effect of treatment of low-dose and high-dose curcumin after ovariectomy in rats. Methods : Forty female Sprague-Dawley rats underwent either a sham operation (the sham group) or bilateral ovariectomy (OVX). The ovariectomized animals were randomly distributed among three groups; untreated OVX group, low-dose (10 mg/kg) curcumin administered group, and high-dose (50 mg/kg) curcumin group. At 4 and 8 weeks after surgery, serum biochemical markers of bone turnover were analyzed. Bone histomorphometric parameters of the 4th lumbar vertebrae were determined by micro-computed tomography (CT). In addition, mechanical strength was determined by a three-point bending test. Results : High-dose curcumin group showed significantly lower osteocalcin, alkaline phosphatase, and the telopeptide fragment of type I collagen C-terminus concentration at 4 and 8 weeks compared with the untreated OVX group as well as low-dose curcumin group. In the analyses of micro-CT scans of 4th lumbar vertebrae, the high-dose curcumin treated group showed a significant increase in bone mineral densities (p=0.028) and cortical bone mineral densities (p=0.036) compared with the low-dose curcumin treated group. Only high-dose curcumin treated group had a significant increase of mechanical strength compared with the untreated OVX group (p=0.015). Conclusion : The present study results demonstrat that a high-dose curcumin has therapeutic advantages over a low-dose curcumin of an antiresorptive effect on bone remodeling and improving bone mechanical strength.

• Journal of Ginseng Research
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• v.44 no.6
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• pp.823-832
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• 2020

Background: The formation of a nanotube layer on a titanium nanotube (N-Ti) plate facilitates an active reaction between bone cells and the material surface via efficient delivery of the surface materials of the dental implant into the tissues. Studies have reported that Korean Red Ginseng extracts (KRGEs) are involved in a variety of pharmacological activities: we investigated whether implantation with a KRGE-loaded N-Ti miniimplant affects osteogenesis and osseointegration. Methods: KRGE-loaded nanotubes were constructed by fabrication on pure Ti via anodization, and MC3T3-E1 cells were cultured on the N-Ti. N-Ti implants were subsequently placed on a rat's edentulous mandibular site. New bone formation and bone mineral density were measured to analyze osteogenesis and osseointegration. Results: KRGE-loaded N-Ti significantly increased the proliferation and differentiation of MC3T3-E1 cells compared with cells on pure Ti without any KRGE loading. After 1-4 weeks, the periimplant tissue in the edentulous mandibular of the healed rat showed a remarkable increase in new bone formation and bone mineral density. In addition, high levels of the bone morphogenesis protein-2 and bone morphogenesis protein-7, besides collagen, were expressed in the periimplant tissues. Conclusion: Our findings suggest that KRGE-induced osteogenesis and osseointegration around the miniimplant may facilitate the clinical application of dental implants.

• The korean journal of orthodontics
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• v.50 no.1
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• pp.42-51
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• 2020

Objective: The objective of this study was to evaluate the effects of cetirizine, a histamine 1 receptor antagonist, on bone remodeling after calvarial suture expansion. Methods: Sixty male Sprague-Dawley rats were divided into 4 groups; the phosphate-buffered saline (PBS)-injected no expansion group, cetirizine-injected no expansion group, PBS-injected expansion group, and cetirizine-injected expansion group, and were observed at 7, 14, and 28 days. Five rats per group were examined at each observation day. Daily injections of cetirizine or PBS were administered to the relevant groups starting 2 weeks prior to expander insertion. A rapid expander was inserted in the calvarial bone to deliver 100 cN of force to the parietal suture. The specimens were prepared for hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) staining. Suture opening and bone regeneration were evaluated using microcomputed tomography and bone histomorphometric analysis. Serum blood levels of osteocalcin and carboxy-terminal collagen crosslinks (CTX) were also evaluated. Results: TRAP-positive cell counts and CTX levels decreased while osteocalcin levels increased in the cetirizine-injected expansion group at observation day 28. In the expansion groups, the mineralized area gradually increased throughout the observation period. At day 28, the cetirizine-injected expansion group showed greater bone volume density, greater mineralized area, and narrower average suture width than did the PBS-injected expansion group. Conclusions: Cetirizine injection facilitated bone formation after suture expansion, mostly by suppressing osteoclastic activity. Histamine 1 receptor antagonists may aid in bone formation after calvarial suture expansion in the rat model.

• The Journal of Advanced Prosthodontics
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• v.2 no.1
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• pp.7-13
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• 2010

Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS. In vitro, the human platelets were activated with application of shear stress, $20\;{\mu}g/ml$ collagen, 2 mM $CaCl_2$ and 10U thrombin/$1\;{\times}\;10^9$ platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with $\beta$-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS. In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION. Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

• Journal of Periodontal and Implant Science
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• v.32 no.4
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• pp.753-767
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• 2002

The purpose of this study was to evaluate histologically the effect of LiF-maleic acid added calcium aluminate(LM-CA) bone cement & CA-PMMA composite bone cement on the healing of calvarial defect in Sprague-Dawley rats. The critical size defects were surgically produced in the calvarial bone using the 8mm trephine bur. The rats were divided in three groups : In the control group, nothing was applied into the defect of each rat. LM-CA bone cement was implanted in the experimental group 1 and CA-PMMA composite bone cement was implanted in the experimental group 2. Rats were sacrificed at 2, 8 weeks after surgical procedure. The specimens were examined by histologic analysis, especially about the bone-cement interface and the response of surrounding tissue. The results are as follows; 1. In the control group, inflammatory infiltration was observed at 2 weeks. At 8 weeks, periosteum and duramater were continuously joined together in the defect area. But the center of defect area was filled up with the loose connective tissue. 2. In the experimental group 1, the bonding between implanted bone cement and the existing bone was seen, which more increased in 8 weeks than 2 weeks. Inflammatory infiltration and the dispersion of implanted bone cement particles were seen in both 2 weeks and 8 weeks. 3. In the experimental group 2, implanted bone itself had a dimensional stability and no bonding between implanted bone cement and the existing bone was seen in both 2 weeks and 8 weeks. Implanted bone cement was encapsulated by fibrous connective tissue. In addition, inflammatory infiltration was seen around implanted bone cement. On the basis of these results, when LM-CA bone cement or CA-PMMA composite bone cement was implanted in rat calvarial defect, LM-CA bone cement can be used as a bioactive bone graft material due to ability of bonding to the existing bone and CA-PMMA can be used as a graft material for augmentation of bone-volume due to dimensional stability.

• Journal of Life Science
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• v.14 no.3
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• pp.385-390
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• 2004

Chitosan is abundant polysaccharide polymer in nature Chitosan has been the subject of much research regarding its potential as a nutritional adjunct and pharmaceutical ingredient. In the present study, we examined fracture-healing process with chitosan administration and low calcium diet in rats. Left femur was fractured and fixed with intramedullary pin. The rats were fed normal diet or low calcium diet and administered chitosan with the doses of 0, 50, 100 and 150ng/ml orally 5 times a week for 10 weeks. Soft X-ray and mechanical testing of all fractured femora was taken. Radiographical finding showed that the callus formation and process of fracture healing was present in all the fractured femora. Mechanical testing indicated that the maximum load and stiffness of femur in rat fed low calcium diet was lower than those of that in rat fed normal diet. No difference in maximum load and stiffness of fractured femora in chitosan treated rat were observed as compared to vehicle treated rat. Chitosan or/and low calcium diet did not affect the ratio of fractured/unfractured femur about maximum load and stiffness. The results suggest that chitosan dose not affect the bone mechanical strength and the process of fracture healing. Low calcium diet does decrease the bone mechanical strength.

• The Journal of Korean Academy of Prosthodontics
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• v.9 no.1
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• pp.47-51
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• 1969

The author has studied the histochemical changes on rat submaxillary gland histological changes on rat periodontium after administration of isoproterenol. The results are as follows: 1) After administration of isoproterenol, the rat submaxillary glands weight of the first and second group were increased two times compared with control group. 2) The acinar cells of rat submaxillary gland were shown the hypertrophy and enlargement. 3) The PAS staining reaction of the acinar cells of rat submaxillary gland were shown the strong positive reaction. 4) The blood vessels of rat periodontium were dilated and alveolar bone resorption was occurred.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.253-263
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• 1995

Microsurgical vascularized bone transfer has the disadvantages of limitation of available donor sites, loss of donor function, and the possibility of donor site defects or deformity. To overcome these shortage of current microsurgical tissue transfer, the method of creating the neovascularized free flap has been introduced. Potentially, this technique must be an innovation in providing the free vascularized bone grafts that are not limited by natural vascular anatomy. But, as could be imagined technique resulted in unavoidable donor bone defect and additional operation for harvesting the autologous bone. The purpose of this study was to evaluate the efficacy of demineralized allogeneic bone as a possible substitute for autologous bone in fabricating the neo-osseous flap. By histologic, microangiographic and radioisotope method, the viability and vascularity of neo-osseous flap, which has been fabricated using allogeneic bone or autologous bone, was assessed in rat model. After 6 weeks, demineralized allogeneic bone showed consistent bone formation and neovascularization. The clinical and microscopic findings of demineralized allogeneic bone group were inferior to those of autogenous bone with regard to bone regeneration. The amount of bone blood floow per dry weight of demineralized allogeneic bone group was significantly higher than that of autogenous bone, even higher that of control intact iliac bone. In conclusion, findings supported that allogeneic bone could be the potential substitute for autologous bone source in creating a prefabricated neo-osseous flap.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.339-350
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• 2017

Purpose: The purpose of this study was to determine the critical diabetes duration in a streptozotocin (STZ)-induced diabetic rat calvarial defect model for experimentation regarding bone regeneration by evaluating the association between diabetes duration and bone healing capacity through histological and radiographic analyses. Methods: Experimental diabetes was induced in 50 of 60 rats by an STZ injection. The rats were divided into 5 groups, including a control group (group 1), according to diabetes durations of 0, 2, 4, 6, and 8 weeks, respectively. Eighteen rats survived: 4 in group 1, 4 in group 2, 4 in group 3, 5 in group 4, and 1 in group 5. Calvarial defects were created at 0, 2, 4, 6, and 8 weeks after STZ injection in groups 1-5. Cone-beam computed tomography scanning was performed at baseline and at 5 and 7 weeks after surgery. The rats were sacrificed 7 weeks after surgery, followed by histological evaluation. Results: The voxel gray values (VGVs) of group 1 and group 2 increased, whereas the VGVs of group 3 and group 4 decreased starting 5 weeks after surgery, although this trend did not reach statistical significance between groups. On the reconstructed 3-dimensional images and based on an analysis of histological features, groups 1 and 2 showed apparent bone regeneration, while groups 3-5 showed very limited bone regeneration. Conclusions: The critical diabetes duration in an STZ-induced diabetic rat calvarial defect model for experimentation regarding bone regeneration was between 2 and 4 weeks. It is suggested that researchers who use STZ-induced diabetic rats wait for more than 2 weeks following diabetes induction before placing implants or conducting bone regeneration studies to allow definite disturbances in bone healing to emerge.