• 대한본초학회지
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• 제36권2호
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• pp.11-17
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• 2021

Objective : This study was conducted to investigate the effects of Effects of Akebia quinata (AQ) extract on alcohol-induced damage of liver, spleen and thymus in rats. Method : Experimental animals were divided in to 4 groups; Normal group, Alcohol group, AQ50 group and AQ200 group. All rats, except for Normal group, were fed 25 % ethanol for 55 days. During experimental period, Normal group and Alcohol group were administrated saline, and AQ50 group and AQ200 group were administrated AQ extract at dose of 50 and 200 mg/kg/day, respectively. We measured organ weight, liver triglyceride contents, and alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and triglycerid levels in serum. Also, we conducted histomorphometry and histopathological observation of liver, spleen and thymus. Results : AQ significantly decreased the level of AST, ALT and triglyceride in serum and the liver triglyceride contents induced by ethanol. Also, AQ significantly inhibited lipid droplets accumulation in hepatocytes. The decreased relative organ weight of spleen and thymus by ethanol were increased by AQ administration. In histopathological analysis of spleen, the rats administrated AQ 200 mg/kg presented significantly increased mean diameters of white pulps, numbers of white pulps and splenic thicknesses. The administration of 200 mg/kg AQ improved decreased lobular thickness and cortex thickness of thymus, which were decreased by ethanol. Conclusions : The results of present study indicated that AQ has an ameliorating effect for fatty degeneration of liver and damage of spleen and thymus.

• Journal of Periodontal and Implant Science
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• 제52권4호
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• pp.312-324
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• 2022

Purpose: The role of hard-type crosslinked hyaluronic acid (HA) with particulate bone substitutes in bone regeneration for combined inlay-onlay grafts has not been fully investigated. We aimed to evaluate the effect of hard-type crosslinked HA used with bone substitute in terms of new bone formation and space maintenance. Methods: A 15-mm-diameter round defect was formed in the calvaria of 30 New Zealand White rabbits. All animals were randomly assigned to 1 of 3 groups: the control group (spontaneous healing without material, n=10), the biphasic calcium phosphate (BCP) graft group (BCP, n=10), and the BCP graft with HA group (BCP/HA, n=10). The animals were evaluated 4 and 12 weeks after surgery. Half of the animals from each group were sacrificed at 4 and 12 weeks after surgery. Samples were evaluated using micro-computed tomography, histology, and histomorphometry. Results: The BCP group showed higher bone volume/tissue volume (BV/TV) values than the control and BCP/HA groups at both 4 and 12 weeks. The BCP and BCP/HA groups showed higher bone surface/tissue volume (BS/TV) values than the control group at both 4 and 12 weeks. The BCP group showed higher BS/TV values than the control and BCP/HA groups at both 4 and 12 weeks. No statistically significant difference in newly formed bone was found among the 3 groups at 4 weeks. The BCP group showed significantly higher new bone formation than the BCP/HA group at 12 weeks. Conclusions: Hard-type crosslinked HA did not show a positive effect on new bone formation and space maintenance. The negative effect of hard-type crosslinked HA may be due to the physical properties of HA that impede osteogenic potential.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.465-478
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• 2007

Various periodontal barrier membranes used in many clinical and experimental fields, and many recent studies of membranes have reported good results. To improve clinical results, selection of barrier membranes is an important factor. So, we need not only to evaluate various barrier mem-branes, but also to understand the property of barrier membranes appropriate to defect characteristics. For this purpose, this study reviewed available literature, evaluated comparable experimental models, and compared various barrier membranes. From above mentioned methods, the following conclusions are deduced. 1. In i-wall periodontal defect models, new bone formation showed a consistent result, almost 30% of the defect size. New cementum formations measured mostly 40% of the defect size, but showed more variations than new bone formations. This seems to be resulted form difference in experimental methods, so standardization in experimental methods is needed for future studies. 2. Application PLGA barrier membrane to periodontal defect demonstrated improved healing in new bone and new cementum. 3. There was a minimal periodontal regeneration with calcium sulfate barrier membrane only. But, there was better healing pattern in combination of calcium sulfate membrane with bone graft material, such as DFDBA, 4. There was no significant difference between the experimental group that used chitosan mem-brane only and the control group. But, in combination with bone graft material for space maintanence, periodontal regeneration was improved. Overall, Space maintenance is a critical factor for Guided tissue regeneration using barrier membranes. Also, a barrier membrane itself that has difficulty in maintaining space, achieved better result when used with graft material.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권3호
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• pp.163-172
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• 2012

Purpose: Diabetes mellitus (DM) has been shown to alter the properties of the bone and impair bone healing around a titanium implant. The aim of this study is to investigate whether the low-intensity pulsed ultrasound (LIPUS), which has been known to stimulate the bone healing, improve the osseointegration of the titanium implant in tibia of DM-induced rats. Methods: 16 rats were received streptozotocin (60 mg/kg) for inducing diabetes. A total number of 32 titanium implants were placed bilaterally into both tibiae of these rats. The right tibia of each rat received LIPUS application (10 min/day) during 7 days post-operation, while the left side received no treatment. The study was carried on for six weeks and the rats were sacrificed at 1, 2, 4, and 6 weaks postoperatively (4 rats for each week) for histomorphometric and histologic analysis. Bone-implant contact and bone area were measured. Comparisons between the groups were made using statistical analysis on histomorphometric analysis. Results: The histomorphometry parameters showed that the bone-implant contact and the bone area values have decreased in the late osseointegration periods (4, 6 weeks) compared to the early osseointegration periods (1, 2 weeks) in both two groups. The bone-implant contact values of the LIPUS group were somewhat higher than those of controls at 1, 2 weeks, but the difference was not statistically significant. The bone area values of the LIPUS group were also higher than those of controls at 1, 2 weeks, but the difference was not statistically significant as well. Conclusion: Results of this study indicate that LIPUS may have positive effects on early osseointegration but could not improve the long term stability of dental implants.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.403-414
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• 2002

I. Purpose of Study Zea Mays L. has been known to be effective for improving periodontal health and Magnoliae cortex to have effective antibacterial and antimicrobial activity against periodontal pathogens. The purpose of this study was to examine the biologic effects of Zea Mays L. and Magnoliae cortex extract mixtures on healing of rat calvarial bone defects. II. Materials & Methods 8mm circular defects were prepared on rat calvaria during surgical procedures of 180 Sprague-Dawley rats. The ethanolic extracts of Magnoliae cortex and Zea Mays L. and these two natural extract 1:1 and 2:1 (Magnoliae: Zea Mays L.) ratio mixtures were oral administrated by oral zondes once a day at two different dose of 94.5mg/kg, 189mg/kg body weight. There are nine groups of rats in this study: control group (no sample loading), Magnoliae cortex extract loading groups (I,II)(94.5mg/kg,189mg/kg respectively), Zea Mays L. extract loading groups (I,II), M:Z(1:1) loading groups (I,II), M:Z(2:1) loading groups(I,II). Rats were sacrificed at 4 weeks and 6 weeks after surgery. New bone formations around calvarial defects were radiographically and histologically measured by computerassisted histomorphometry. Each data was statistically analyzed by One-way ANOVA test. III. Results There were statistical significances between negative control group and the other test groups on radiographical and histological quantitative assessments. Among test groups, mixture groups showed statistical significances, especially, M:Z (2:1) groups (I and II) were highly significant.(p<0.05) These results implicated that the mixture of Magnoliae and Zea Mays L. (2:1 mixing ratio) with 94.5mg/kg concentration might be highly effective on the wound healing of bony defected site and have potential possibilities as a useful drug to promote bone tissue regeneration.

• 대한치과보철학회지
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• 제38권5호
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• pp.659-674
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• 2000

A large increase in the use of thin film coating of hydroxyapatite(HA) in implant dentistry is driven by the desire to take advantage of the excellent biocompatibility and high strength of HA coating. The purpose of this study was to evaluate the effects of HA-coated implants by ion Beam Assisted Deposition(IBAD) method in comparison to the sand-blasted and machined surfaces. Osteoblast culture test, removal torque test and histomorphometric analysis were performed and the following results obtained; 1. Examination of the osteoblast cultures displayed no difference in the secretion of alkaline phosphatase between the various specimen, but IBAD with pure HA specimen showed low alkaline phosphatase secretion(p<0.05). 2. Removal torque tests showed HA-coated implants by IBAD method to be similar in high value to the implants with sand-blasted surface than the implants with machined surface. And the ovariectomized group showed low mechanical test value than the normal group(p<0.05). 3. Histomorphometrical comparisons were performed on undecalcified ground sections. HA-coated implants by IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and 3-best consecutive threads, and the implants with sand-blasted surface and implants with machined surface was in the next consecutive order(p<0.05). HA-coated implants showed slightly higher bone-to- metal contact ratio than sand-blasted implants, but no statistically significant difference was obtained between the two materials. The ovariectomized group showed lower value of bone-to-metal contact ratio than the normal group, but no statistically significant difference was obtained between the two groups. 4. Evaluation of bone volume on all threads and 3-best consecutive threads showed no statistically significant difference among the different surface treatment groups, but showed lower bone volume in ovariectomized group than in the normal group(p<0.05). According tn these results, thin film coated implants with HA showed high bone contact ratio, bone volume and removal torque strength in the short term, but long term observation is needed.

• 한국한의학연구원논문집
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• 제16권2호
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• pp.167-179
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• 2010

Objective : The present study has been undertaken to investigate the preventive effects of Daekumeumja on fatty degeneration of liver and immunosuppression induced by alcohol in rats. Method : Except for the normal group, we fed rat on 25% alcohol for 55 days. And Daekumeumja(DK) extract was administrated for the same period. We measured the serum component in rat's blood, weight of internal organs, liver triglyceride contents, histomorphometry and histopathological observation of internal organs. Results : 1. In the change measurement of serum components, DK group(50 mg/kg, 200 mg/kg) showed significant decrease of AST, ALT, albumin, ALP and triglyceride in comparison with those of the alcohol control group. 2. In the change measurement of internal organ's weight, DK group(50 mg/kg, 200 mg/kg) showed significant increase of relative body weights of liver, thymus and spleen in comparison with those of the alcohol control group. 3. DK group(50 mg/kg, 200 mg/kg) showed significant decrease of hepatic triglyceride contents in comparison with those of the alcohol control group. 4. In histomorphometrical changes of liver, DK group(50 mg/kg, 200 mg/kg) showed significant decrease of numbers of hepatocytes occupied by over 10% lipid droplets, percentages of regions occupied by lipid droplets and mean diameters of hepatocytes in comparison with those of the alcohol control group. In histomorphometrical changes of thymus, DK group(50 mg/kg, 200 mg/kg) showed significant increase of lobular thickness and cortex thickness in comparison with those of the alcohol control group. In histomorphometrical changes of spleen, DK group(50 mg/kg, 200 mg/kg) showed significant increase of splenic thicknesses, numbers of white pulps and mean diameters of white pulps in comparison with those of the alcohol control group. 5. In histopathological changes of liver, DK group(50 mg/kg, 200 mg/kg) showed effective inhibition of severe fatty changes in comparison with those of the alcohol control group. In histopathological changes of thymus and spleen, DK group(50 mg/kg, 200 mg/kg) showed effective inhibition of atrophic changes in comparison with those of the alcohol control group. Conclusions : Reviewing these experimental results, it appears that Daekumeumja have pharmaceutical preventive efficacy on fatty degeneration of liver and immunosuppression induced by alcohol in rats.

• Journal of Periodontal and Implant Science
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• 제39권sup2호
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• pp.213-222
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• 2009

Purpose: Recently, interest in chitosan has increased due to its excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. On the other hand, hydroxyapatite is used as a bone substitute in the fields of orthopedics and dentistry. The hydroxyapatite-chitosan (HA-CS) complex containing hydroxyapatite nanoparticles was developed for synergy of both biomaterials. The objective of this study was to evaluate the effect of hydroxyapatite (HA)-chitosan (CS) membrane on bone regeneration in the rat calvarial defect. Methods: Eight-millimeter critical-sized calvarial defects were created in 70 male Sprague-Dawley rats. The animals were divided into 7 groups of 10 animals and received either 1) chitosan (CS) 100% membrane, 2) hydroxyapatite (HA) 30%/CS 70% membrane, 3) HA 30%/CS 70%, pressed membrane, 4) HA 40%/CS 60% membrane, 5) HA 50%/CS 50% membrane, 6) HA 50%/CS 50%, pressed membrane, or 7) a sham . surgery control. The amount of newly formed bone from the surface of the rat calvarial defects was measured using histomorphometry, following 2- or 8- week healing intervals. Results: Surgical implantation of the HA - CS membrane resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. The HA - CS membrane would be significantly more effective than the chitosan membrane in early bone formation. Conclusions: Concerning the advantages of biomaterials, the HA-CS membrane would be an effective biomaterial for regeneration of periodontal bone. Further studies will be required to improve the mechanical properties to develop a more rigid scaffold for the HA-CS membrane.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.155-163
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• 2000

Osteoporosis is the consequence of an imbalance between osteoclastic and osteoblastic activity, coupled with an increased rate of bone turnover observed with menopause. Estrogen is generally considered to maintain bone mass through suppression of bone resorption. The purpose of this study was to evaluate the rat femoral trabecular change not only in the deficiency of estrogen but also in the administration of estrogen following ovariectomy(OVX). 30 female Sprague-Dawley rats were subjected to bilateral OVX or sham surgery(control). Groups of OVX were divided into 4 groups. The first group was injected daily with vehicle alone for 20 days after 20 weeks following OVX. The additional groups of OVX was injected daily with low, medium, or high doses of $17{\beta}-estradiol$(10, 25 or $50{\mu}g/kg$ BW, respectively). All rats were sacrified 23 weeks after OVX, and their femur were processed for H&E, MT stain and histomorphometry. The results were as follows; 1. In the histomorphometric analysis, the trabecular bone volume/tissue volume, trabecular thickness and trabecular seperation were respectively $31.2{\pm}8.3%$, $54.3{\pm}4.8{\mu}m$ and $280.7{\pm}16.4{\mu}m$ in vehicle treated OVX group and $48.6{\pm}7.3%$, $90.4{\pm}4.5{\mu}m$ and $126.3{\pm}5{\mu}m$ in sham operation group, and they showed statistical significance compare to control group. 2. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in low doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group. 3. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $44.4{\pm}4.3%$, $109.5{\pm}12.3{\mu}m$ and $94.9{\pm}8.5{\mu}m$ in medium doses of $17{\beta}-estradiol$ injected group and they showed statistical significance compare to OVX group, but they didn't show statistical significance compare to low doses of $17{\beta}-estradiol$ injected group. 4. The trabecular bone volume/tissue volume, trabecular thickness and trabecular separation were respectively $46.4{\pm}4.5%$, $154.4{\pm}13.2{\mu}m$ and $113.7{\pm}12.8{\mu}m$ in high doses of $17{\beta}-estradiol$ injected group and they also showed statistical significance compare to OVX group, but they didn't show statistical significance compare to other experimental groups. From the above results, metaphyseal bone formation was markedly reduced in OVX rate but treatment of OVX rats with $17{\beta}-estradiol$ resulted in normalization of femur trabecular bone volume. But they didn't show statistical significance the effect of bone formation according to the dose dependency.

• 대한치과보철학회지
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• 제39권6호
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• pp.659-681
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• 2001

Platelet-rich plasma(PRP) has been known to increase the rate and degree of bone formation by virtue of growth factors in concentrated platelets. Although its great healing effect on bone defect or pre-implantation site preparation in conjunction with bone substitute has been reported, the effect associated with implant is unknown. The purpose of this study was to investigate the effect of PRP on rapid osseointegration of endosseous dental implants in the rabbit tibiae. Twenty two adult female New Zealand white rabbits, weighing approximately 2.7-3.3kg, were used for this study. Twelve of the 22 animals were used for histomorphometric analysis and ten of the 22 were for removal torque test. Each animal received two implants in each tibia (two treated with PRP and two as control) and was given fluorochrome intramuscularly. For histomorphometric analysis, rabbits were divided into four groups according to the healing period. At 1 week, 2 weeks, 4 weeks and 8 weeks postoperatively, each three animals were sacrificed serially and the amount and rate of bone formation around dental implant were examined on the undecalcified sections under fluorescent microscope, polarized microscope and light microscope connected to a personal computer equipped with image analysis system. For removal torque test, rabbits were divided into two groups and removal torque tests were performed at 4 weeks, 10 weeks after implant placement. In total, 88 screw shaped, commercially pure titanium implants (Neoplant, Neobiotech, Seoul, Korea) were used in this study. Labeling pattern reflected differences of two groups in bone formation rate at each period. Histomorphometrically, PRP group showed significantly higher bone volume within threads compared to control group at 2 weeks ($70.30{\pm}4.96%$ vs. $50.68{\pm}6.33%$; P < .01) and 4 weeks ($82.59{\pm}5.94%$ vs. $72.94{\pm}4.57%$; P < .05 ). PRP group at 1, 2 and 4 weeks revealed similar degree of bone volume formation comparable to control group at 2, 4 and 8 weeks, respectively. On the other hand, while PRP group showed higher bone-implant contact ($47.37{\pm}8.09%$) than control group ($33.16{\pm}13.47%$) at 2 weeks, there were no significant differences between PRP group and control group for any experimental period. Removal torque values also showed no significant differences between PRP group and control group at any experimental period (P > .05). These findings imply that PRP could induce rapid, more bone formation around implant during early healing period and get faster secondary stability for reducing healing period, though it has not induced bone maturation enough to resist functional loading.