• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1377-1385
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• 2009

Effect of inclusion of hard vs. soft wheat bran with different particle size on diet digestibility, growth performance and some slaughter traits was evaluated in fattening rabbits. Four isonitrogenous and isocaloric diets were used according to the origin of wheat bran (hard (HWB) - Triticum durum - and soft (SWB) - Triticum aestivum) combined with wheat bran particle size sieved by 2 mm (fine: 2) or by 8 mm (coarse: 8) in a bifactorial (2${\times}$2) study. A growth trial was conducted to measure the effect of treatments on performance in one hundred and twenty New Zealand White${\times}$Californian rabbits fed experimental diets from 50 to 87 days of age. Faecal apparent digestibility was determined within the last week in twenty animals per diet. Digestibility of nutrients was higher (p<0.05) in the diet containing HWB2, except for crude protein, ether extract and ash, than fine and coarse soft wheat bran diets. Final live weight, feed intake and feed consumption of rabbits on the diet with fine hard wheat bran were higher and resulted in greater daily weight gains (p<0.01) than for animals on the other diets. The slaughter yield and percentage value of organs were not significantly (p>0.05) affected by the diets fed; however, the diet containing fine hard wheat bran led to lower (p<0.05) percentages of skin, abdominal fat and carcass drip loss than the other dietary treatments. It is concluded that fine hard wheat bran can be better included in the diet than soft wheat bran to maximize growth performance without affecting carcass traits of fattening rabbits.

• Journal of Periodontal and Implant Science
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• v.48 no.4
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• pp.202-212
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• 2018

Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.543-551
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• 2007

When clinicians faced with an insufficient volume of supporting bone on ideally esthetic and bio-mechanical position for dental implantation, guided bone regeneration(GBR) was indicated. Although GBR has wide application at clinic, proper time of membrane removal remains qustionable in using non-resorbable membrane, such as non-expanded polytetrafluoroethylene(PTFE), The aim of this study was to compare the effect of maintenance period of PTFE membrane on bone regeneration in rabbit calvarial defects. Eight adult New Zealand white female rabbits were used in this study. Four defects were surgically made in their calvaria. Using a trephine bur, 4 'through and through' defects were created and classified into 3 groups, which were consisted of control group(no graft), experimental group 1(autogenous bone)and experimental group 2(deproteinized bovine bone; $OCS-B^{(R)}$). The defects were covered with PTFE membrane($Cytoplast^{(R)}$). Membranes were removed after 1, 2, 4 and 8 weeks post-GBR procedure in 2 rabbits repectively, All rabbits were sacrificed after 8 week post-GBR procedure. Specimens were harvested and observed histologically. The results were as follow; 1) The use of graft material and membrane was necessary in GBR procedure. 2) When PTFE membranes were removed early, the most favorable bone regeneration was revealed in experimental group T, followed by experimental group II and control group. 3) On GBR, it is recommended that membrane should maintain for 4 weeks with autogenous graft. As well, the use of xenograft need longer maintenance period than autogenous bone. Further evaluations will be needed, such as histomorphologic research, more species and different kinds of graft materials. And on the basis of these studies, clinical researches would be required.

• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.427-447
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• 1992

The purpose of this study was to evaluate the effect of the lateral displacement on the mandibular condylar growth in the rabbit. The experimental animals were twenty White NewZealand rabbits of 4-week old. Ten of them was used as control group, and experimental animal was composed of remaining ten. Laterodeviation appliance was made of cast base metal and appliance was cemented with resin in permanent fashion. Experimental group were sacrificed at 1, 2, 4, 6, 8 weeks form beginning of the experiment. Both of temporomandibular joint were prepared for histologic study. The conclusions are: 1. In control group, there was slight increase of proliferative zone and hypertrophic zone at 2-week control animal and slight reduction at 4-week. 6-week and 8-week control animal were similiar to 1-week control animal. 2. In right mandibular condyle of experimental group, 2-week experimental animal showed marked increase of proliferative zone and hypertrophic zone at posterior surface of condylar head. In 8-week experimental animal marked increase at anterior surface of anticular surface is observed. 3. In left mandibular condyle of experimental group, proliferative zone and hypertrophic zone were reduced at 1-week experimental animal and slight increase at 2-week. Proliferative zone and hypertrophic zone were reduced at 4-week experimental animal and were slightly increased at 6 week. 4. After 8 weeks, right and left condyle were not different in experimental group. The condylar cartilage was stabilized 8 weeks after the experiment. No marked traumatic change was seen, but minute focal bleeding was seen at articular cavity in 1-week, 2-week and 4-week experimental animal. 6-week and 8-week experimental animal did not show bleeding tendency in articular cavity.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.10
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• pp.1421-1424
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• 2005

The aim of this study was to evaluate the effect of two diets different in crude fibre content and ingredients on performance and on caecal characteristics of rabbits around weaning. Thirty litters from thirty New Zealand White does were divided at Day 18 in two groups fed, respectively, a low fibre concentrate (LFC, consisting mainly of soybean meal, delactated whey, barley) from Day 18-28 followed by a creep feed (CF, consisting mainly in alfalfa meal, barley and wheat bran) from Day 29-32, and a CF from Day 18-32. After weaning (32 days) both groups were fed the CF ad libitum for two weeks. During the pre-weaning period, mortality, milk intake and solid feed intake (from Day 20) were recorded daily, while the live weight of kits was recorded twice, at 18 and 32 days. At day 28, one rabbit/litter was slaughtered in order to obtain data on caecal content characteristics. After weaning, the rabbits were located in collective cages, feeding ad libitum CF; feed intake, live weight and mortality were recorded weekly for two weeks. During the preweaning period, there were no differences between the groups in milk and solid feed intake and, by consequence, in live weight at weaning; instead, the mortality was higher (12.5 vs 4.5%) for the group (A) that changed diet at 28 days. Group A showed also a higher caecal pH (6.12 vs. 5.72), propionate to butyrate ratio (0.73 vs. 0.46), ammonia content (9.3 vs. 7.1 mmol/l), but a lower total volatile fatty acid content (66.8 vs. 82.1 mmol/l) than B Group, probably due to the dried milk whey in the concentrate. After weaning, there were no significant differences between the two groups. The authors concluded that the use of a low fibre concentrate for suckling rabbits is not recommended.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.7-12
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• 2009

Purpose: Gelatin-hydroxyapatite nanocomposite is similar to inorganic nanostructure of bone. To make a scaffold with osteoinductivity, bone marrow derived stem cells from rabbit femur were impinged into the nanocomposite. This vitro study was to test osteogenic differentiation of the stem cells in the nanocomposite, which was made by authors. Material & Methods: Gel-HA nanocomposite with 10g of HA, 3 g of Gel has been made by co-precipitation process. Bone marrow was obtained from femur of New Zealand White rabbits and osteogenic differentiation was induced by culturing of the BMSCs in an osteogenic medium. The BMSCs were seeded into the Gel-HA nanocomposite scaffold using a stirring seeding method. The scaffolds with the cells were examined by scanning electron microscopy (SEM), colorimetry assay, biochemical assay with alkaline phosphatase (ALP) diagnostic kit, osteocalcin ELISA kit. Results: Gel-HA nanocomposite scaffolds were fabricated with relatively homogenous microscale pores ($20-40{\mu}m$). The BMSCs were obtained from bone marrow of rabbit femurs and confirmed with flow cytometry, Alizarin red staining. Attachment and proliferation of BMSCs in Gel-HA nanocomposite scaffold could be identified by SEM, ALP activity and osteocalcin content of BMSCs. Conclusion: The Gel-HA nanocomposite scaffold with micropores could be fabricated and could support BMSCs seeding, osteogenic differentiation.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.645-660
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• 1993

In this study, effects of incision of retrodiscal tissue and unilateral occlusal reduction on temporomandibular joint of rabbit were investigated. Twenty-seven adult New Zealand White Rabbits, weighing over 3.5kg, were utilized in this study. Temporomandibular joint surgery was performed in left temporomandibular joint of 24 rabbits to displace disc anteriorly through incising the retrodiscal tissue 1-2mm posterior to the disc. They were divided into two groups : twelve were left untreated after surgery, occlusal reduction was performed on left posterior teeth every 2 weeks in the other twelve rabbits, The remaining three served as the control group. The sample were sacrificed by 8, 12, and 16 weeks after surgery. Histologic examinations were performed after sacrificing them. The results were as follows : 1. Histologic findings which were manifested by flat articular fossa, broad articular surface, generalized recession of articular cartilage and sclerosis of subchondral bone were observed. These findings were similar to internal derangement. 2. In the rabbits untreated after surgery, thin cartilagenous layer and necrotic tissue were observed in 8 weeks group, calcifying cartilagenous layer was observed in 12 weeks group, and cartilagenous layer on anterior portion was observed in 16 weeks group. So, it showed gradual healing pattern into the normal tissue except displaced disc. 3. Occlusal trauma after surgery resulted in generalized recession of upper and lower articular surface. Necrosis and vertical split on condylar process of mandible were observed in 8 weeks group. Osteoclasts, exposure of subchondral bone due to erosion on upper and lower articular surface, and degenerative changes on retrodiscal tissue were observed in 16 weeks group. So, it showed continuous prowess pattern of osteoarthrosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.250-254
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• 2010

Introduction: This study evaluated the bone regenerative effect of silk fibroin mixed with platelet-rich fibrin (PRF) of a bone defect in rabbits. Materials and Methods: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter: 8.0 mm). The silk fibroin mixed with PRF was grafted into the right parietal bone (experimental group). The left side (control group) was grafted only PRF. The animals were sacrificed at 4 weeks and 8 weeks. A micro-computerized tomography (${\mu}$CT) of each specimen was taken. Subsequently, the specimens were decalcified and stained for histological analysis. Results: The average value of plane film analysis was higher in the experimental group than in the control group at 4 weeks and 8weeks after surgery. However, the difference was not statistically significant.(P>0.05) The tissue mineral density (TMD) in the experimental group at 4 weeks after surgery was significantly higher than the control group.(P<0.05) Conclusion: Silk fibroin can be used as a scaffold of PRF for rabbit calvarial defect repair.

• Biomedical Science Letters
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• v.14 no.3
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• pp.179-186
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• 2008

Matrix metalloproteinases (MMPs), also designated matrixins, hydrolyze components of the extracellular matrix. These proteinases playa central role in many biological processes, such as embryogenesis, normal tissue remodeling, wound healing, and angiogenesis, and in diseases such as atheroma, arthritis, cancer, and tissue ulceration. In previous data, disruption of the actin cytoskeleton by cytochalasin D (CD) inhibited NO-induced apoptosis, dedifferentiation, cyclooxygenase (COX)-2 expression, and prostaglandin $E_2$ production in chondrocytes cultured on plastic or during cartilage explants culture. In this study, we investigated the effects of the actin cytoskeleton architecture on MMP-2 expression and dedifferentiation by CD in rabbit articular chondrocytes. Rabbit articular chondrocytes were prepared from cartilage slices of 2-weeks-old New Zealand white rabbits by enzymatic digestion. CD was used as a disruptor of actin cytoskeleton. In this experiments measuring CD dose response, primary chondrocytes were treated with various concentrations of CD for 24h. The actin disruption was determined by immunostaining. MMP-2 expression levels were determined by immunoblot analysis and Reverse transcriptase-Polymerase chain reaction (RT-PCR) and MMP-2 activity was determined by gelatin zymography. We found that cell morphological change and up-regulation of MMP-2 expression by CD as determined via immunostaining, gelatin zymography and immunoblotting. Moreover, CD induced MMP-2 transcription was detected by RT-PCR. Also, CD-induced type II collagen expression was inhibited by MMP-2 inhibitor I treatment. Our results indicate that CD up-regulated MMP-2 activation causes dedifferentiation of articular chondrocyte.

• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.153-162
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• 2002

For the induction of arthropathy, 5% hydrogen peroxide($H_2O_2$) was injected for 5 weeks into the intraarticular space of the New Zealand white rabbits to damage articular cartilage. Alginic acid of low molecular weight (2%) made from macromolecular alginate treated with enzyme was administered into articular space at the dose of 5 mg/kg twice a week for 3 and 6 weeks using 1 ml syringe and 26 G needle. Saline was injected for the control. Tissues surrounding the articulation were obtained for the measurements of superoxide dismutase(SOD) activity as a major antioxidant enzyme and malondialdehyde (MDA) as a lipid peroxidation level. Histopathologic examination on the surface of articular cartilage was carried out. Data showed that injection of hydrogen peroxide for 5 weeks had led to the induction of free radical damage and of articular cartilage change as confirmed by microscopic observation. The application of hydrogen peroxide caused a gradual increase in the SODs and MDA. These patterns were similar after 3 and 6 weeks of alginate treatment. Furthermore, microscopic examinations revealed that hydrogen peroxide caused flaking, fibrillation, fissuring, denudation, and hypocellularity in the articular surfaces. In conclusion, lipid peroxidation was demonstrated in the articular cartilage by the administration of hydrogen peroxide in the rabbit model. This lipid peroxidation could be caused by oxygen free radicals. The histologic and enzymatic correlations on lipid peroxidation in the articulation have provided a better understanding of arthropathy. It is possible to take advantage of these findings to evaluate effective alginate dosage more efficiently.