• Journal of Periodontal and Implant Science
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• v.42 no.4
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• pp.119-126
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• 2012

Purpose: The aim of this study was to determine whether biphasic calcium phosphate (BCP) bone substitute with two different concentrations of Escherichia coli-expressed recombinant human bone morphogenetic protein 2 (ErhBMP-2) enhances new bone formation in a standardized rabbit sinus model and to evaluate the concentration-dependent effect of ErhBMP-2. Methods: Standardized, 6-mm diameter defects were made bilaterally on the maxillary sinus of 20 male New Zealand white rabbits. Following removal of the circular bony windows and reflection of the sinus membrane, BCP bone substitute without coating (control group) was applied into one defect and BCP bone substitute coated with ErhBMP-2 (experimental group) was applied into the other defect for each rabbit. The experimental group was divided into 2 subgroups according to the concentration of ErhBMP-2 (0.05 and 0.5 mg/mL). The animals were allowed to heal for either 4 or 8 weeks and sections of the augmented sinus and surrounding bone were analyzed by microcomputed tomography and histologically. Results: Histologic analysis revealed signs of new bone formation in both the control and experimental groups with a statistically significant increase in bone formation in experimental group 1 (0.05 mg/mL ErhBMP-2 coating) after a 4-week healing period. However, no statistically significant difference was found between experimental group 1 and experimental group 2 (0.5 mg/mL ErhBMP-2 coating) in osteoinductive potential (P<0.05). Conclusions: ErhBMP-2 administered using a BCP matrix significantly enhanced osteoinductive potential in a standardized rabbit sinus model. A concentration-dependent response was not found in the present study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.360-373
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• 2006

The purpose of this research was to investigate whether pulsed electromagnetic field (PEMF) stimulation applied to the rabbit cranial defects grafted with ${\beta}$-tricalcium phosphate (${\beta}$-TCP) could affect the new bone formation. With 16 New Zealand white rabbits under the same condition, bilateral calvarial bone defects were formed around the sagittal suture line. The defect on the left side was grafted with ${\beta}$-TCP, while on the right side was grafted by harvested autogenous bone. PEMF was applied to 8 rabbits for 8 hours per day. The bony specimen were divided into 3 groups, the group 1 was autogenous bone grafted specimen, the group 2 was ${\beta}$-TCP grafted with PEMF, and the group 3 was ${\beta}$-TCP grafted without PEMF. We investigated the bone regeneration & growth factor expression at 2, 4, 6, and 8 weeks. As a result, BMP 2 was expressed in the group 1 from 2 weeks, the group 2 from 4 weeks, and the group 3 from 6 weeks. BMP 4 was expressed in the group 1 from 2 weeks, in the group 2 and the group 3 from 4 weeks. 4. There was no significant difference in expression pattern of BMP 7, PDGF, VEGF, and TGF-${\beta}$1 during grafted bone regeneration in group 1, 2, and 3. According to our results, PEMF stimulation could be effective on the new bome formation in animal study, and have a feasibility of clinical use.

• Investigative Magnetic Resonance Imaging
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• v.7 no.2
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• pp.116-123
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• 2003

Purpose : The present study was undertaken to evaluate the usefulness of cerebral diffusion (DWI) and perfusion MR imaging (PWI) in rabbit models with hyperacute cerebral ischemic infarction. Materials and Methods : Experimental cerebral infarction were induced by direct injection of mixture of Histoacryl glue, lipiodol, and tungsten powder into the internal cerebral artery of 6 New-Zealand white rabbits, and they underwent conventional T1 and T2 weighted MR imaging, DWI, and PWI within 1 hour after the occlusion of internal cerebral artery. The PWI scan for each rabbit was obtained at the level of lateral ventricle and 1cm cranial to the basal ganglia. By postprocessing using special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were obtained. The detection of infarcted lesion were evaluated on both perfusion maps and DWI. MTT difference time were measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Results : In all rabbits, there was no abnormal signal intensity on T2WI. But on DWI, abnormal high signal intensity, suggesting cerebral infarction, were detected in all rabbits. PWI (rCBV, CBF and MTT map) also showed perfusion defect in all rabbits. In four rabbits, the calculated square of perfusion defect in MTT map is larger than that of CBF map and in two rabbits, the calculated size of perfusion defect in MTT map and CBF map is same. Any rabbits do not show larger perfusion defect on CBF map than MTT map. In comparison between CBF map and DWI, 3 rabbits show larger square of lesion on CBF map than on DWI. The others shows same square of lesion on both technique. The size of lesion shown in 6 MTT map were larger than DWI. In three cases, the size of lesion shown in CBF map is equal to DWI. But these were smaller than MTT map. The calculated square of lesion in CBF map, equal to that of DWI and smaller than MTT map was three. And in one case, the calculated square of perfusion defect in MTT map was largest, and that of DWI was smallest. Conclusion : DWI and PWI may be useful in diagnosing hyperacute cerebral ischemic infarction and in e-valuating the cerebral hemodynamics in the rabbits.

• Journal of Life Science
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• v.20 no.10
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• pp.1427-1432
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• 2010

This study was carried out to evaluate neutralization effects against WSSV using antiserum produced from recombinant envelop protein, rVP466 of WSSV. The VP466 gene of WSSV was cloned into pCold I expression vector and rVP466 was expressed in E. coli RIPL. The antiserum against rVP466 was produced in white rabbits (New Zealand white rabbit). The specific immunoreactivity to the antigen, rVP466, was confirmed by Western blot. The constant amounts of WSSV at $1{\times}10^4$ diluted stocks were mixed with various antiserum concentrations and then injected to the muscle of shrimp, Penaeus chinensis, for the neutralization challenge. The shrimps challenged with WSSV as a positive control and those with the mixture of WSSV and preimmune serum as a preimmune control showed 100% cumulative mortality at 17 days post challenge and 83% at 25 days post challenge, respectively. The shrimps challenged with 3 different mixtures of WSSV and rVP466 antiserum at ratios of 1:0.01, 1:0.1 and 1:1 showed 73%, 53% and 46% cumulative mortalities at 25 days post challenge, respectively. These results indicated that WSSV could be neutralized by the rVP466 antiserum. These results suggest that envelop protein VP466 is involved in the initial step of WSSV infection in shrimp.

• The korean journal of orthodontics
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• v.38 no.5
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• pp.328-336
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• 2008

Objective: The purpose of this study was to compare the torque resistance to removal of sandblasted large grit and acid etched (SLA) surface treated orthodontic mini-implants and smooth surface orthodontic mini-implants as well as performing histologic observations. Methods: Two groups of custom screw shaped orthodontic mini-implants (C-implant, 1.8 mm outer diameter $\times$ 9.5 mm length, Cimplant, Seoul, Korea) were designated. 22 SLA treated C-implants (SLA group) and 22 machined surface C-implants (machined group) were placed in the tibia metaphysis of 11 adult New Zealand white rabbits. Following a 6-week healing period, the rabbits were sacrificed. Subsequently, the C-implants were removed under reverse torque rotation with a digital torque measuring device and independent t-test was performed. Selected tissues were prepared for histologic observation. Results: The SLA group presented a higher mean removal torque value (6.286 Ncm) than the machined group (4.491 Ncm) which was statistically significant (p < 0.005). Histologic observation revealed a trend of more new bone formation in contact with the screw surface in the SLA group than the smooth group. Conclusions: The results of this study suggested that SLA surface treatment can enhance the osseintegration potential for C-orthodontic mini-implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.520-530
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• 2006

Undifferentiated mesencymal stem cells(UMSCs) have been thought to be multipotent cells that can replicate as undifferentiated cells and that have the potential to differentiate into lineages of mesenchymal tissue including the bone, cartilage, fat, tendon, muscle, and marrow stroma. It can be used to sinus lifting, Guided bone regeneration, other bone graft in dental part. The purpose of this study is to evaluate the effect of mesencymal stem cells on sinus augmentation with autogenous bone, fibrin glue mixture in a rabbit model. 8 New Zealand white rabbits were divided randomly into 4 groups based on their time of sacrifice(1, 2, 4 and 8 weeks). First, undifferentiated mesenchymal stem cells were isolated from iliac crest marrow of rabbits and expanded in vitro. cell culture was performed in accordance with the technique described by Tsutsumi et al. In the present study, The animals were sacrificed at 1, 2, 4 and 8 weeks after transplantation, and the bone formation ability of each sides was evaluated clinically, radiologically, histologically and histomorphologically. According to the histological observations, Stem cell group showed integrated graft bone with host bone from sinus wall. At 2 and 4weeks, It showed active newly formed bone and neovascularization. At 8 weeks, lamella bone was observed in sinus graft material area. Radiologically, autobone with stem cell showed more radiopaque than autobone without stemcell. there were significant differences in bone volume between 2 and 4 weeks (p<0.05). In summary, the autobone with stem cells had well-formed, newly formed bone and neovasculization, compared with the autobone without stem cells (esp. 2 weeks and 4 weeks) The findings of this experimental study indicate that the use of a mixture of mesenchymal stem cell yielded good results in osteogenesis and bone volume comparable with that achieved by autogenous bone. Therefore, this application of this promising new sinus floor elevation method for implants with tissue engineering technology deserves further study.

• Journal of Conservation Science
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• v.33 no.4
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• pp.255-266
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• 2017

Chemically derived pesticides have been used to prevent biological damage to domestic cultural property. However, their use is gradually being restricted due to the harmful effects on the human body and environment. Therefore, there is a growing interest in the search for new antifungal biopharmaceuticals whose safety has been confirmed by toxicity evaluation through animal experiments. This paper presents methods of toxicity evaluation of natural biocides using Sprague-Dawley rats and New Zealand White (NZW) rabbits. Safety of the natural biocide extract of Asarum sieboldii was evaluated using single-dose oral and dermal toxicity tests in Sprague-Dawley rats, and eye and skin irritation tests in NZW rabbits. The extract has proven antimicrobial and insecticidal activities against wood-rotting fungi and termites. After single oral administration to rats, the $LD_{50}$ values were determined to be over 4,000 and 2,000 mg/kg for males and females, respectively. After single dermal administration to rats, the $LD_{50}$ values exceeded 10,000 mg/kg for both males and females. The extract was identified to be non-irritant to the rabbit eye, and only slightly irritant to the rabbit skin. In this study, we confirmed the safety of the A sieboldii extract through animal testing. Due to the harmfulness of humidifier disinfectants, focus is on the safety of chemical pesticides, and toxicity evaluation is suggested as the basic method for hazard evaluation.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.168-172
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• 2003

Radiation synovectomy is one of the most useful methods for treating patients with refractory synovitis because of its convenience, long-term effects, repeatability and the avoidance of surgery. In this study, we investigated the toxicity, stability and biodistribution of a rhenium-188 ($^{188}$Re)-tin colloid to evaluate its suitability as a synovectomy agent. Twenty four hours after injecting the $^{188}$Re-tin colloids (74 KBq/0.1 mL) into the tail vein of ICR mice, most of the $^{188}$Retin colloidal particles was found in the lungs. In addition, there were no particle size changes at either room temperature or at $37^{\circ}C$ after injecting the $^{188}$Re-tin colloids in human plasma and synovial fluid. In vitro stability tests showed that the $^{188}$Re-tin colloid remained in a colloidal form without a critical size variation over a 2-day period. We investigated the leakage of $^{188}$Retin colloids from the intraarticular injection site with gamma counting in New Zealand white rabbits. The $^{188}$Re-tin colloids (55.5 MBq/0.15 mL) were injected at the cavum articular and the mean retention percentage of the $^{188}$Re-tin colloid was 98.7% for 1 day at the injection site, which suggests that there was neither change in the particle size nor leakage at the injection sites. In the biodistribution study with the SD rats, the liver showed the highest radioactivity (0.0427% ID/organ) except for the injected knees (99.49%). In the SD rats, mild toxicities including the skin or a synovium inflammation were observed as a result of a radioactivity of 15 mCi/kg at the intraarticular injection site. However, there was no systemic toxicity. In the Ovalbumin (OVA)-induced arthritic rabbits, the $^{188}$Re-tin colloid improved the macroscopic, the histological score and reduced the knee joint diameter when compared to the arthritic control. In conclusion, a $^{188}$Re-tin-colloid is considered as a strong candidate for radiation synovectomy with a superior efficacy and safety.

• Journal of Korean Dental Science
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• v.6 no.2
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• pp.58-66
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• 2013

Purpose: The inferior alveolar nerve (IAN) can be damaged as a result of minor oral surgical procedure such as third molar extraction or implant placement. Repair of the injured IAN involves difficulty of access, and research studies are limited to elucidating the process of regeneration by surgical methods. This study sought to establish the rabbit animal model to apply polymeric membrane functionalized with nerve growth factor after a crush lesion for the evaluation of nerve regeneration using the electrophysiologic method. Materials and Methods: The IAN of 2 adult male New Zealand white rabbits (4 nerves) were exposed bilaterally, and crush injury rendered by jeweler's forceps was applied. Nerve conduction velocity was examined electrophysiologically using electromyography before, after, and 4 weeks after the crush injury. To evaluate the regeneration, the pattern of action potential of IAN was recorded, and the characteristics of neurons were histologically observed. Result: After the crush injury, afferent activity decreased in the injured group. Electromyography could not be recorded after four weeks because tissues surrounding the injured nerve collapsed. Decrease in the mean number of axons was observed in the injured part with membrane. Conclusion: Despite the limited result, the present animal model study may provide a possible way to research on the methods of enhancing the recovery of nerve injuries in clinical situations. For clinically widespread acceptance, however, it should gain more consecutive and scientific evidences.

• Archives of Plastic Surgery
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• v.43 no.6
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• pp.491-497
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• 2016

Background Hypertrophic scarring is a pathological condition that occurs after trauma or surgery. Angiogenesis occurs more often with hypertrophic scarring than with normotrophic scarring. The regulation of angiogenesis is one of the key factors in hypertrophic scar management. Vascular endothelial growth factor (VEGF) is an essential factor in the angiogenetic response. This study investigated whether decreasing the level of VEGF is effective for treating hypertrophic scarring. Methods Ten 8-week-old female New Zealand white rabbits were included. Four defects were created on each ear by using a 6-mm punch. Bevacizumab (Avastin, Roche Pharma, Basel, Switzerland) was administered in one ear and normal saline was administered in the other ear. Treatment was administered starting on day 2, every 2 days, until day 14. The levels of VEGF were measured using enzyme-linked immunosorbent assay on day 10 and histologic results were analyzed on day 40. Results Bevacizumab induced-defects showed less hypertrophic scarring when compared with the control group as measured by the scar elevation index (SEI) and loose collagen arrangement. The SEI in the experimental group was $1.89{\pm}0.13$, compared to $1.99{\pm}0.13$ in the control group (n=30, P=0.005). Additionally, the VEGF level was lower ($38.72{\pm}11.03pg$ vs. $82.50{\pm}21.64pg$, n=10, P=0.001) and fewer vessels existed ($8.58{\pm}0.76$ vs. $7.2{\pm}1.20$, n=10, P=0.007). Conclusions Preventing excessive angiogenesis is effective for preventing scar formation, especially with hypertrophic scarring. Although it is not an approach that is sufficient alone for the management of scarring, it may be one of several important strategies for scar treatment.