차량운전 모사장치를 위한 수정된 병렬구조형 플랫폼의 역기구학 해석

박봉욱,김정하,남준우 한국자동차공학회 1995 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1995 No.11_1

Many foreign automotive companies have been experimenting with new concepts for the Vehicle Driving Simulator. But still many researchers utilized the basic 6 D.O.F parallel type of Stewart Platform, which is fundamentIy using for the Flight Simulation Equipment.<br/> We think it is sufficient if having 4 or 5 D.O.F rather than the Flight Simulator according to the characteristics of a Vehicle Driving Simulator.<br/> In this paper, We propose the new mechanism of 5 D.O.F Modified In-Parallel Platform and also solve the inverse kinematic problems.<br/>

배양된 인간 골막기원세포의 조골세포 분화과정에서 골기질 형성정도와 혈관내피세포성장인자 신호와의 상관관계

박봉욱,변준호,류영모,하영술,김덕룡,조영철,성일용,김종렬,Park, Bong-Wook,Byun, June-Ho,Ryu, Young-Mo,Hah, Young-Sool,Kim, Deok-Ryong,Cho, Yeong-Cheol,Sung, Iel-Yong,Kim, Jong-Ryoul 대한악안면성형재건외과학회 2007 Maxillofacial Plastic Reconstructive Surgery Vol.29 No.3

Angiogenesis is a essential part for bone formation and bone fracture healing. Vascular endothelial growth factor (VEGF), one of the most important molecules among many angiogenic factors, is a specific mitogen for vascular endothelial cells. VEGF-mediated angiogenesis is required for bone formation and repair. However, the effect of VEGF on osteoblastic cells during osteogenesis is still controversial. In recent days, substantial progress have been made toward developing tissue-engineered alternatives to autologous bone grafting for maxillofacial bony defects. Periosteum has received considerable interest as a better source of adult stem cells. Periosteum has the advantage of easy harvest and contains various cell types and progenitor cells that are able to differentiate into a several mesenchymal lineages, including bone. Several studies have reported the bone formation potential of periosteal cells, however, the correlation between VEGF signaling and cultured human periosteal cell-derived osteogenesis has not been fully investigated yet. The purpose of this study was to examine the correlation between VEGF signaling and cultured human periosteal-derived cells osteogenesis. Periosteal tissues of $5\;{\times}\;20\;mm$ were obtained from mandible during surgical extraction of lower impacted third molar from 3 patients. Periosteal-derived cells were introduced into the cell culture and were subcultured once they reached confluence. After passage 3, the periosteal-derived cells were further cultured for 42 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and ${\beta}-glycerophosphate$. We evaluated the alkaline phosphatase (ALP) activity, the expression of Runx2 and VEGF, alizarin red S staining, and the quantification of osteocalcin and VEGF secretion in the periosteal-derived cells. The ALP activity increased rapidly up to day 14, followed by decrease in activity to day 35. Runx2 was expressed strongly at day 7, followed by decreased expression at day 14, and its expression was not observed thereafter. Both VEGF 165 and VEGF 121 were expressed strongly at day 35 and 42 of culture, particularly during the later stages of differentiation. Alizarin red S-positive nodules were first observed on day 14 and then increased in number during the entire culture period. Osteocalcin and VEGF were first detected in the culture medium on day 14, and their levels increased thereafter in a time-dependent manner. These results suggest that VEGF secretion from cultured human periosteal-derived cells increases along with mineralization process of the extracellular matrix. The level of VEGF secretion from periosteal-derived cells might depend on the extent of osteoblastic differentiation.

Deleted in Azoospermia-Like Enhances In Vitro Derived Porcine Germ Cell Formation and Meiosis

박봉욱 MARY ANN LIEBERT INC 2013 STEM CELLS AND DEVELOPMENT Vol.22 No.6

고용량의 Dexamethasone 존재하에서 골막기원세포에서 발현되는 혈관신생인자의 평가

박봉욱,최문정,류영모,이성균,하영술,김덕룡,조영철,김종렬,변준호,Park, Bong-Wook,Choi, Mun-Jeong,Ryu, Young-Mo,Lee, Sung-Gyoon,Hah, Young-Sool,Kim, Deok-Ryong,Cho, Yeong-Cheol,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2008 Maxillofacial Plastic Reconstructive Surgery Vol.30 No.3

Angiogenesis plays an important role in bone development and postnatal bone fracture repair. Vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) have been thought to be primarily involved in promoting angiogenesis. It is well known that VEGF and its receptors have been reported to play an important role in the regulation of the interaction between angiogenesis and osteogenesis during bone repair processes. Dexamethasone, a potent synthetic glucocorticoid, promotes phenotype markers of osteoblast differentiation, such as ALP and osteocalcin. It stimulates in vitro osteogenesis of human bone marrow osteogenic stromal cells. Dexamethasone has been reported to suppress VEGF gene expression in some cells. However, our previous study demonstrated VEGF quantification increased in a time-dependent manner in periosteal-derived osteogenesis under dexamethasone. So, the purpose of this study was to examine the angiogenic phenotypes in cultured human periosteal-derived cells under high-dose dexamethasone. Periosteal-derived cells were cultured using a technique previously described. After passage 3, the periosteal-derived cells were further cultured for 28 days in an osteogenic inductive culture medium containing ascorbic acid, ${\beta}$-glycerophosphate and high-dose dexamethasone, We evaluated the expression of VEGF isoforms, VEGFR-1, VEGFR-2, and neuropilin-1, ALL VEGF isoforms ($VEGF_{121},\;VEGF_{165},\;VEGF_{189}$, and $VEGF_{206}$) expression was observed by RT-PCR analysis. VEGFR-1, VEGFR-2 and neuropilin-1 expression increased up to day 14, particularly during the early stage of mineralization. Our results suggest the involvement of direct VEGFs/VEGFRs system on periosteal-derived cells during early mineralization phase under high-dose of dexamethasone. These also suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.

인간 골막기원세포와 Polydioxanone/Pluronic F127 담체를 이용한 골형성

박봉욱,이진호,오세행,김상준,하영술,전령훈,맹건호,노규진,김종렬,변준호,Park, Bong-Wook,Lee, Jin-Ho,Oh, Se-Heang,Kim, Sang-June,Hah, Young-Sool,Jeon, Ryoung-Hoon,Maeng, Geun-Ho,Rho, Gyu-Jin,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2012 Maxillofacial Plastic Reconstructive Surgery Vol.34 No.6

Purpose: The purpose of this study is to examine in vivo osteogenesis of cultured human periosteal-derived cells and polydioxanone/pluronic F127 scaffold. Methods: Two one-year-old miniature pigs were used in this study. $2{\times}10^6$ periosteal-derived cells in 1 mL medium were seeded by dropping the cell suspension into the polydioxanone/pluronic F127 scaffold. These cell-scaffold constructs were cultured in osteogenic Dulbecco's modified Eagle's medium for 7 days. Under general anesthesia with azaperone and tiletamine-zolazepam, the mandibular body and ramus of the pigs were exposed. Three bony defects were created. Polydioxanone/pluronic F127 scaffold with periosteal-derived cells and the scaffold only were implanted into each defect. Another defect was left empty. Twelve weeks after implantation, the animals were sacrificed. Results: New bone formation was clearly observed in the polydioxanone/pluronic F127 scaffold with periosteal-derived cells. Newly generated bone was also observed in the scaffold without periosteal-derived osteoblasts and empty defect, but was mostly limited to the periphery. Conclusion: These results suggest that cultured human periosteal-derived cells have good osteogenic capacity in a polydioxanone/pluronic F127 scaffold, which provides a proper environment for the osteoblastic differentiation of these cells.

성인의 하악과두 골절 환자의 임상적,방사선학적 연구

박봉욱,변준호 대한악안면성형재건외과학회 2004 Maxillofacial Plastic Reconstructive Surgery Vol.26 No.6

배양된 치유두 유래세포의 조골활성 및 골기질 형성의 평가

박봉욱,변준호,최문정,하영술,김덕룡,조영철,성일용,김종렬,Park, Bong-Wook,Byun, June-Ho,Choi, Mun-Jeoung,Hah, Young-Sool,Kim, Deok-Ryong,Cho, Yeong-Cheol,Sung, Iel-Yong,Kim, Jong-Ryoul 대한악안면성형재건외과학회 2007 Maxillofacial Plastic Reconstructive Surgery Vol.29 No.4

In the present study, we focused on stem cells in the dental papilla of the tooth germ. The tooth germ, sometimes called the tooth bud, is the primordial structure from which a tooth is formed. The tooth germ consists of the enamel organ, the dental papilla, and the dental follicle. The dental papilla lies below a cellular aggregation of the enamel organ. Mesenchymal cells within the dental papilla are responsible for formation of dentin and pulp of a tooth. Tooth germ disappears as a tooth is formed, but that of a third molar stays in the jawbone of a human until the age of 10 to 16, because third molars grow slowly. Impacted third molar tooth germs from young adults are sometimes extracted for orthodontic treatment. In the present study, we evaluated the osteogenic activity and mineralization of cultured human dental papilla-derived cells. Dental papillas were harvested from mandible during surgical extraction of lower impacted third molar from 3 patients aged 13-15 years. After passage 3, the dental papilla-derived cells were trypsinized and subsequently suspended in the osteogenic induction DMEM medium supplemented with 10% fetal bovine serum, 50 g/ml L-ascorbic acid 2-phosphate, 10 nM dexamethasone and 10 mM -glycerophosphate at a density of $1\;{\times}10^6\;cells/dish$ in a 100-mm culture dish. The dental papilla-derived cells were then cultured for 6 weeks and the medium was changes every 3 days during the incubation period. Dental papilla-derived cells showed positive alkaline phosphatase (ALP) staining during 42 days of culture period. The formation of ALP stain showed its maximal manifestation at day 7 of culture period, then decreased in intensity during the culture period. ALP mRNA level was largely elevated at 1 weeks and gradually decreased with culture time. Osteocalcin mRNA expression appeared at day 14 in culture, after that its expression continuously increased in a time-dependent manner up to day 28. The expression remained constant thereafter. Runx2 expression appeared at day 7 with no detection thereafter. Von Kossa-positive mineralization nodules were first present at day 14 in culture followed by an increased number of positive nodules during the entire duration of the culture period. Osteocalcin secretion was detectable in the culture medium from 1 week. The secretion of osteocalcin from dental papilla-derived cells into the medium greatly increased after 3 weeks although it showed a shallow increase by then. In conclusion, our study showed that cultured human dental papilla-derived cells differentiated into active osteoblastic cells that were involved in synthesis of bone matrix and the subsequent mineralization of the matrix.

배지 성분에 따른 인간 지방조직기원 CD146 양성 혈관내피세포의 증식 및 기능의 평가

박봉욱,하영술,김진현,조희영,정명희,김덕룡,김신원,김욱규,김종렬,변준호,Park, Bong-Wook,Hah, Young-Sool,Kim, Jin-Hyun,Cho, Hee-Young,Jung, Myeong-Hee,Kim, Deok-Ryong,Kim, Shin-Won,Kim, Uk-Kyu,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2010 Maxillofacial Plastic Reconstructive Surgery Vol.32 No.6

Purpose: This study was to examine the proliferation and function of the adipose tissue-derived endothelial cells according to different culture medium conditions. Materials and Methods: Adipose tissue-derived CD146 positive endothelial cells were cultured in according to different culture mediums (DMEM culture medium with or without osteogenic inductive agents and EBM-2 culture medium with or without osteogenic inductive agents). The proliferation and function of the adipose tissue-derived endothelial cells was examined in different culture medium conditions. Results: Adipose tissue-derived endothelial cells formed tube-like structures on Matrigel in EBM-2 culture medium with or without osteogenic inductive agents. However, the cells did not form tube-like structures on Matrigel in DMEM medium with or without osteogenic inductive agents. After 24 hours of culture, among the culture medium using EBM-2, the proliferation of the cells were promoted in EBM-2 medium without osteogenic inductive agents than in EBM-2 medium with osteogenic inductive agents. However, 72 hours of culture, the proliferation of the cells were promoted in EBM-2 medium with osteogenic inductive agents than in EBM-2 medium without osteogenic inductive agents. Conclusion: These results suggest that the proliferation and function of the adipose tissue-derived CD146 positive endothelial cells could be maintained in EBM-2 with osteogenic inductive agents.

혈관내피유사세포 채취의 원천으로 골막의 활용

박봉욱,김신원,김욱규,하영술,김진현,김덕룡,성일용,조영철,손장호,김종렬,변준호,Park, Bong-Wook,Kim, Shin-Won,Kim, Uk-Kyu,Hah, Young-Sool,Kim, Jin-Hyun,Kim, Deok-Ryong,Sung, Iel-Young,Cho, Yeong-Cheol,Son, Jang-Ho,Kim, Jong-Ryoul,Byun, 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.5

Purpose: The periosteum is a well-known source of osteogenic precursor cells for tissue-engineered bone formation. However, cultured endothelial or endothelial-like cells derived from periosteum have not yet been investigated. This study focused on endothelial-like cell culture from the periosteum. Methods: Periosteal tissues were harvested from the mandible during surgical extraction of lower impacted third molars. The tissues were treated with 0.075% type I collagenase in phosphate-buffered saline (PBS) for 1 hr at $37^{\circ}C$ to release cellular fractions. The collagenase was inactivated with an equal volume of DMEM/10% fetal bovine serum (FBS) and the infranatant was centrifuged for 10 min at 2,400 rpm. The cellular pellet was filtered through a $100{\mu}m$ nylon cell strainer, and the filtered cells were centrifuged for 10 min at 2,400 rpm. The resuspended cells were plated into T25 flasks and cultured in endothelial cell basal medium (EBM)-2. Results: Among the hematopoietic markers, CD146 was more highly expressed than CD31 and CD34. The periosteal-derived cells also expressed CD90 and CD166, mesenchymal stem cell markers. Considering that the expression of CD146 was constant and that the expression of CD90 was lower at passage 5, respectively, the CD146 positive cells in passage 5 were isolated using the magnetic cell sorting (MACS) system. These CD146 sorted, periosteal-derived cells formed tube-like structures on Matrigel. The uptake of acetylated, low-density lipoprotein, labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI-Ac-LDL) was also examined in these cells. Conclusion: These results suggest that the CD146-sorted positive cells can be referred to as periosteal-derived CD146 positive endothelial-like cells. In particular, when a co-culture system with endothelial and osteoblastic cells in a three-dimensional scaffold is used, the use of periosteum as a single cell source would be strongly beneficial for bone tissue engineering.

하악골 신장술 후 하치조신경의 조직학적 변화와 신경성장인자의 발현에 대한 연구

박봉욱,김종렬,변준호,Park, Bong-Wook,Kim, Jong-Ryoul,Byun, June-Ho 대한악안면성형재건외과학회 2005 Maxillofacial Plastic Reconstructive Surgery Vol.27 No.5

Distraction osteogenesis (DO) is frequently used technique in reconstruction of bony defects resulted from tumor resection, congenital deformity, and trauma in the maxillofacial region. Although the histologic and ultrastructural changes associated with distraction osteogenesis have been extensively described, the exact changing of the surrounding tissues, such as nerve tissues, were still unclear. This study observed the histological changes and the expression of nerve growth factor (NGF) in the inferior alveolar nerve (IAN) after distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight mongrel dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted IAN and contralateral control nerve were harvested and processed for histological and innunohistochemical examinations. The signs of acute nerve injuries, such as demyelination and partial discontinuation of nerver fiber, were observed in the distracted IAN on 7 and 14 days after distraction. The initial remyelination and regeneration of distracted IAN were showed at 14 days after completion of distraction. At 56 days later, the histologic features of distracted IAN was similar to those of the normal control IAN. The expression of NGF was significantly increased in most distracted nerve tissues on 7, 14 and 28 days after distraction. On 56 days after distraction, the expression of NGF returned to the normal level. This study suggested that the acute IAN injury caused by mandibular distraction were mostly recovered during consolidation period. The NGF was seemed to be induced from Schwann cell and damaged nerve tissues, and it may have important roles in the initial healing of damaged nerves.