• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.235-250
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• 2005

The current interest in periodontal tissue regeneration has lead to research in bone graft, root surface treatments, guided-tissue regeneration, administration of growth factors, and the use of enamel matrix protein as possible means of regenerating lost periodontal tissue. Several studies have shown that a strong correlation between platelet-rich plasma and the stimulation of remodeling and remineralization of grafted bone exits, resulting in a possible increase of 15-30% in the density of bone trabeculae. The purpose of this study was to study the histopathological results and differences between the use of platelet-rich plasma and the use of enamel matrix $protein(Emdogain^?)$ about bone regeneration at the implant. Implant fixtures were inserted and graft materials placed into the left femur in the experimental group, while the only implant fixtures placed in the control group. In the first experimental group, platelet-rich plasma and xenograft were placed at the supracrestally placed implant site, and in the second experimental group, $Emdogain^{(R)}$ and xenograft placed at the supracrestally placed fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2, 4, and 8 weeks after implant fixture insertion. The results of the experiment are as follows: 1. The rate of osseointegration to the fixture threads was found to be greater in the experimental group compared to in the control group. 2. The histopathological findings showed that the bone regeneration, the partial osseointegration existed at 4 weeks, and that osseointegration and bone density increaced in the experimental groups at 8 weeks. 3. The results showed that new bone formation and bone remodeling increased in the area near to the fixture in the first and second experimental groups at 8 weeks than at 4 weeks. The results showed that in the area distant from the fixture, new bone formation did not increase and bone remodeling decreased in the first experimental group at 4, 8 weeks, and that new bone formation increased in the second experimental group. 4. The histopathological findings showed that AZ deposition in the first experimental group was remarkable at 2, 8 weeks, and in the second experimental group at 2, 4, 8 weeks in the area distant from the fixture threads.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.823-837
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• 2005

The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and enamel matrix protein used in conjunction with xenograft. compared to a control group with regards to bone regeneration at the grade III furcation area in beagle dogs. Control group was treated with bovine derived bone $powder(Biocera^{(R)})$, and experimental I group was treated with bovine derived bone powder and Platelet-rich plasma and experimental II group was treated with bovine derived bone powder and Enamel matrix $protein(Emdogain^{(R)})$. The regeneration rate of bone formation was observed and compared histopathologically at 2. 4, and 8 weeks after surgery. The results were as follows: 1. In control group and both experimental groups. inflammatory cells were observed but, new bone formation wasn't. 2. In control group, new cementum on the notch was found in 4 weeks, less mature periodontal ligament when compared to that of experimental group was found and cementum formation was great but, regeneration couldn't be seen in 8 weeks. 3. Experimental I group. new bone formation in the area adjacent to alveolar bone and graft material surrounded by more dense connective tissue were found in 4 weeks. New bone formation up to crown portion was found and periodontal ligament was aligned functionally and cementum more mature. 4. Experimental II group, new bone formation was found under the defect area in 4 weeks and new bone formation around graft material in 8 weeks, too, and there were a number of fibroblasts, blood vessels, acellular cementum, which was less mature when compared to that of experimental I group, and dense collagen fiber like which normal periodontal ligament has in periodontal ligament of experimental II group in 8 weeks. 5. As a result of histologic finding, bone formation rate were 18.0${\pm}$7.87%(control group), 34. 05${pm}$7.25%(experimental I group), 19.33 ${pm}$5.15%(experimental II group) in 4 weeks and 21.89${pm}$1.58%(control group), 38.82${pm}$3.2(experimental I group), 37.65${pm}$9.22%(experimental II group) in 8 weeks. 6. Statistically significant ratio of bone formation was observed in experimental I group in 4 weeks and in experimental II group in 8 weeks. When experimental I group was compared to experimental II group, the ratio of bone formation in experimental I group was higher than that in experimental II group in 4 weeks(p<0.05). This results suggest that platelet-rich plasma showed more new bone formation than enamel matrix protein within 4 weeks. And use of enamel matrix protein in the treatment of periodontal bone defects starts to enhance regeneration after 8 weeks in beagle dogs.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.961-974
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• 2005

Various biological approaches to the promotion of periodontal regeneration have been used. These can be divided into the use of growth and differentiation factors, application of extracellular matrix proteins and attachment factors and use of mediators of bone metabolism. The purpose of this study was to evaluate the effect of enamel matrix protein and platelet-rich plasma on the treatment of intrabony defect, with bovine-derived bone powder in humans by digital subtraction radiography. 12 teeth(experimental I group) were treated with enamel matrix protein combined with bovine-derived bone powder and 12 teeth(experimental II group) were treated with platelet-rich plasma combined with bovine-derived bone powder. The change of bone density was assessed by digital subtraction radiography in this study. The change of mineral content was assessed in the method that two radiography were put into computer program to be overlapped and the previous image was subtracted by the later one. Both groups were statistically analyzed by Wilcoxon signed Ranks Test and Mann-whitney Test using SPSS program for windows(5% significance level). The results were as follows: 1. The radiolucency in 3 months after surgery was significantly increased than 1 month after surgery in both groups(experimental I and II groups)(p<0.05). 2. The radiopacity in 6 months after surgery was significantly increased than 3 months after surgery in both groups(experimental I and II groups) (p<0.05). 3. In experimental I group, there was no significant difference between 1 month and 6 months after surgery. 4. In experimental II group. the radiopacity in 6 months after surgery was significantly increased than 1 month after surgery(p<0.05). 5. There was no significant difference between experimental I and II group at 1 month and 3 months after surgery, but the radiopacity in experimental II group was significantly increased at 6 months after surgery(p<0.05). In conclusion, platelet-rich plasma can enhance bone density than enamel matrix protein until 6 months after surgery.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.530-535
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• 2013

Background Platelet-rich plasma (PRP) has more concentrated platelets than normal plasma (approximately 150-400${\times}10^3$ cell/dL). Platelets excrete several growth factors and cytokines that are associated with the healing and regeneration process. However, even though PRP is widely used, the mechanism or actual effect is presently unclear. Therefore, this study was performed to investigate the levels of growth factors and platelet concentration rate. Methods Autologous blood for preparing PRP was obtained from healthy subjects aged 25 to 35 years. The samples were divided into 4 experimental groups (inactivated whole blood, inactivated PRP, activated whole blood with thrombin and calcium chloride, and activated PRP). The platelet counts in the blood were analyzed and the growth factors were quantitatively measured. A statistical analysis was performed by using Dunn's multiple comparison test. Results In the blood cell analysis, the platelet count of the PRP group was approximately 4.25 times higher than that of the whole blood group. In the quantitative analysis of growth factors, the platelet-derived growth factor (PDGF)-AB, PDGF-BB, and transforming growth factor-${\beta}$ of the inactivated and activated PRP groups were higher than those of the inactivated and activated whole blood groups (P<0.05). Conclusions In this study, the platelet count and the levels of PDGF-AB and PDGF-BB in the PRP were determined. Further, more research is required on the bioactivity level of the growth factors secreted during the process of PRP preparation and the potency of growth factors that can be exerted physiologically in vivo.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권2호
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• pp.140-150
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• 2005

Maxillary sinus lifting procedure and bone grafting are used to reconstruct atrophic maxillae. These procedure are usually followed by the placement of endosseous dental implants. Different materials and techniques can be used for sinus bone grafting. Platelets are known to contain various growth factors involved in the repair of the vasculature and tissues, and it is known that the specialized platelet secretory granules, the alpha granules, contain platelet derived growth factor(PDGF), transforming growth factor-beta(TGF-beta), insuline like growth factor-I(IGF-I), epidermoid growth factor(EGF), and others. This study was to evaluate the effect of PRP on bone formation in a sinus bone grafting. Twelve rabbits were included in this randomized, blinded, prospective pilot study. In experimental group, sinus bone grafting with autobone and platelet rich plasma. In control group, sinus bone grafting with only autobone. Rabbits were sacrificed at 2nd, 4th, 8th, 12th weeks postoperatively. Clinical and radiographic tests, histological analysis were conducted to compare both sides. In clinical examination, there in no significant difference between experimental group and control group. But, in radiographic examination, a distinct incresed in the radiopaque of the PRP experimental group at 2nd and 4th weeks. The histologic examination revealed that more new bone formation and osteoblast activity were seen in experimental group at 2nd and 4th weeks. In conclusion, PRPs action in sinus bone grafting had a capacity of increased new bone formation in a early bone healing stage.

• Clinics in Shoulder and Elbow
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• 제21권1호
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• pp.3-14
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• 2018

Background: Platelet-rich plasma (PRP) stimulates cell proliferation and enhances matrix gene expression and synthesis. However, there have been no comparative study of the PRP effect on the normal and degenerative tenocytes. The purpose of this study was to compare the effect of PRP on tenocytes from normal and degenerative tendon. Methods: Tendon tissues were obtained from patients undergoing arthroscopic repair (n=9) and from healthy donors (n=3). Tenocytes were cultured with 10% (vol/vol) platelet-poor plasma, PRP activated with calcium, and PRP activated with calcium and thrombin. The total cell number was assessed at days 7 and 14. The expressions of type I and III collagen, decorin, tenascin-C, and scleraxis were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction. The total collagen and glycosaminoglycan (GAG) synthesis was evaluated at days 7 and 14. Results: No differences were observed between the groups at day 7, but cell proliferation was remarkably increased in tenocytes from the degenerative tendon at day 14. In both tenocyte groups, the gene expressions of type I and III collagen were up-regulated. GAG synthesis was greater in the normal tendon, whereas the expressions of decorin and tenascin-C were increased in tenocytes from the degenerative tendon. Tenocytes from the degenerative tendon had higher fold-change of GAG synthesis and a lower collagen III/I ratio than normal tenocytes. Conclusions: PRP promoted the cell proliferation and enhanced the synthesis of tendon matrix in both groups. PRP has a greater positive effect on cell proliferation, matrix gene expression and synthesis in tenocytes from degenerative tendon.

• Clinical and Experimental Reproductive Medicine
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• 제47권2호
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• pp.94-100
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• 2020

The inverse correlation between maternal age and pregnancy rate represents a major challenge for reproductive endocrinology. The high embryo ploidy error rate in failed in vitro fertilization (IVF) cycles reflects genetic misfires accumulated by older oocytes over time. Despite the application of different follicular recruitment protocols during IVF, gonadotropin modifications are generally futile in addressing such damage. Even when additional oocytes are retrieved, quality is frequently poor. Older oocytes with serious cytoplasmic and/or chromosomal errors are often harvested from poorly perfused follicles, and ovarian vascularity and follicular oxygenation impact embryonic chromosomal competency. Because stimulation regimens exert their effects briefly and immediately before ovulation, gonadotropins alone are an ineffective antidote to long-term hypoxic pathology. In contrast, the tissue repair properties (and particularly the angiogenic effects) of platelet-rich plasma (PRP) are well known, with applications in other clinical contexts. Injection of conventional PRP and/or its components (e.g., isolated platelet-derived growth factors as a cell-free substrate) into ovarian tissue prior to IVF has been reported to improve reproductive outcomes. Any derivative neovascularity may modulate oocyte competence by increasing cellular oxygenation and/or lowering concentrations of intraovarian reactive oxygen species. We propose a mechanism to support intrastromal angiogenesis, improved follicular perfusion, and, crucially, embryo ploidy rescue. This last effect may be explained by mRNA upregulation coordinated by PRP-associated molecular signaling, as in other tissue systems. Additionally, we outline an intraovarian injection technique for platelet-derived growth factors and present this method to help minimize reliance on donor oocytes and conventional hormone replacement therapy.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.251-261
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• 2005

Alveolar ridge defects may limit or restrict placement of implants. The purpose of this study was to evaluate clinical and histopathologic results which occur following guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane in the localized alveolar bone defects. Ten patients who required guided bone regeneration in implant placemnet, were slelected. Alveolar crest height and width were measured at baseline and, afer 2nd surgery 5 months later At 5 months , we obtained histopathological results as follows: 1. Alveolar crest height was an average of $8.20{\pm}3.74$ mm preoperatively and decreased to an average of $7.40{\pm}1.84$ mm postoperatively. There was no significant difference. 2. Alveolar crest width was an average of $4.25{\pm}2.03$ mm preoperatively and significantly increased to an average of $7.20{\pm}2.44$ mm postoperatively (P<0.01) 3. The change of Alveolar crest height and width were $0.80{\pm}1.40$ mm, $2.95{\pm}1.09$ mm 4. Histopathological evaluations revealed new bone formation with graft material and laminated bone containing the presence of osteocyte-like cell In conclusion, guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane would provide a viable therapeutic alternative for implant placement in the localized alveolar defect or implant failure

• 대한소아치과학회지
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• 제39권2호
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• pp.174-180
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• 2012

성장 중인 아동에서는 치근의 성장이 계속됨에 따라 치수가 괴사되어 치근의 병변이 있는 미성숙 영구치에서도 치수의 재혈관화가 실제로 일어날 수 있다는 가능성이 제시 되고 있다. 치수의 재혈관화를 위해서는 근관 내의 감염의 조절과 함께 적절한 scaffold가 필요하며, platelet-rich plasma(PRP)가 이상적인 scaffold로 제시되었다. 최근 임상에서는 PRP의 단점을 극복한 platelet-rich fibrin(PRF)가 응용되고 있다. 본 증례에서는 치외치의 교두 파절로 인한 치수 감염으로 치근단 병변을 가진 미성숙 영구치의 근관 내에 ciprofloxacin, metronidazole, minocycline의 세 가지 항생제 적용 후 이와 함께 PRF를 적용하였다. 정기적인 검진 결과 치근단 병변의 치유와 함께 치근 성장이 관찰되었다. 이러한 보존적인 근관 치료는 미성숙 영구치에서 치근단 형성술의 대안적인 치료로서 이용될 수 있을 것이며, 향후 장기간의 임상적 관찰이 필요할 것이다.

• 대한약리학회지
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• 제20권1호
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• pp.41-46
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• 1984

카드뮴중독으로 혈소판응집이 항진되어 고혈압 또는 동맥경화증이 발생한다는 연구보고를 감안하여 가토와 흰쥐의 생체내 실험으로서 미세혈전의 형성, Malondialdehyde(MDA) 및 thromboxane $B_2(TXB_2)$치에 미치는 카드뮴의 효과를 검토하고, in vitro실험으로 카드뮴을 처치한 가토 대동맥절편이 혈소판응집에 미치는 영향을 관찰하였으며, prostacyclin의 합성능력을 측정하여 그 결과를 다음과 같이 요약하였다. 1)Cadmium chloride 2mg/kg을 매주 동물의 복강내에 주입하였을 때 미세혈전형성이 증가되었다. 2) 카드뮴 중독동물의 platelet-rich plasma (PRP)는 MDA와 $TXB_2$형성이 정상동물에서 보다 현저히 증가되었다. 3) 카드뮴을 중독시킨 가토의 platelet-poor plasma (PPP)에서의 lipid peroxide치는 대조군과 차이가 없었다. 4) In vitro 실험으로, 가토대동맥 절편에서의 6-keto-$PGF_{1{\alpha}}$의 생성은 카드뮴 농도에 비례하여 억제되었고 이때 혈소판 응집률의 증가와 평행하였다. 5) 이상의 결과로서 카드뮴은 동맥내피세포에서 prostacyclin 합성을 억제할 뿐만 아니라 혈소판에서 $TXA_2$합성을 촉진시켜 그 결과로 혈소판 응집률을 증가시켰음을 알 수 있었다.