• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.3
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• pp.265-286
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• 1997

Bone morphogenetic proteins(BMPs) are a group of transforming growth factor beta(TGF-${\beta}$)-related factors and multifunctional proteins, especially the only known biologic factors capable of inducing endochondral bone formation at an extraskeletal site. This study was performed to investigate the effect of the partially purified porcine BMP(pBMP) at an ectopic site. PBMP was partially purified from porcine bone matrix and its activity was monitored by an in vivo bioassay. The purification method utilized extraction of the bone-inducing activity with 4M guanidine, followed by chromatography on heparin-Sepharose. Active fractions were assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. And the fractions were reconstituted with inactive insoluble collagenous bone matrix from rats, acid soluble type I collagen from rat tail and chondroitin-6-sulfate sodium salt and implanted into the pectroralis muscle pouches of Sprague-Dawley rats. And the carrier complex was implanted on the opposite side as control. The rats were sacrificed at the day of 1st, 3rd, 5th, 7th, 11th, 14th and 21st after implantation and examined histologically, radiologically and biochemically. And alkaline phosphatase activity and calcium content were used as indices of bone formation. The results were as follows ; 1. Active fractions were localized in a zone between 31 and 40 KDa on SDS-PAGE. 2. The implanted 3.0mg of the partially purified pBMP induced cartilage and bone in the muscle tissue of rats through an endochondral ossification process. 3. Inactive insoluble bone matrix, type I collagen and chondroitin-6-sulfate have functioned as carriers for pBMP, but revealed some foreign body reactions. 4. Soft X-ray didn't reveal significant change between the experimental and the control group. 5. The alkaline phosphatase activities in the experimental group of 5th, 7th, 11th, 14th and 21st were increased significantly compared with control (p<0.01) with the peak in the group of 11th day. 6. With time, the calcium content of the experimental group increased. And the calcium contents in the experimental group of 11th, 14th and 21st were increased significantly compared with control (p<0.01).

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.1-23
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• 2001

Chitosan is biodegradable natural polymer that has been demonstrated its ability to improve wound healing, and calcium metaphosphate(CMP) is a unique class of phosphate minerals having a polymeric structure. In this study, chitosan/CMP and platelet derived growth factor(PDGF-BB) loaded chitosan/CMP sponges were developed, and the effect of the sponges on bone regeneration and their possibility as scaffolds for bone formation by three-dimensional osteoblast culture were examined. PDGF-BB loaded chitosan/CMP sponges were prepared by freeze-drying of a mixture of chitosan solution and CMP powder, and soaking in a PDGF-BB solution. Fabricated sponge retained its 3-dimensional porous structure with $100-200\;{\mu}m$ pores. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with $^{125}I-labeled$ PDGF-BB. In order to examine their possibility as scaffolds for bone formation, fetal rat calvarial osteoblastic cells were isolated, cultured, and seeded into the sponges. The cell-sponge constructs were cultured for 28 days. Cell proliferation, alkaline phosphatase activity were measured at 1, 7, 14 and 28 days, and histologic examination was performed. In order to examine the effect on the healing of bone defect, the sponges were implanted into rat calvarial defects. Rats were sacrificed 2 and 4 weeks after implantation and histologic and histomorphometrical examination were performed. An effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. PDGF-BB loaded chitosan/CMP sponges supported the proliferation of seeded osteoblastic cells as well as their differentiation as indicated by high alkaline phosphatase activities. Histologic findings indicated that seeded osteoblastic cells well attached to sponge matrices and proliferated in a multi-layer fashion. In the experiments of implantation in rat calvarial defects, histologic and histomorphometric examination revealed that chitosan/CMP sponge promoted osseous healing as compared to controls. PDGF-BB loaded chitosan/CMP sponge further echanced bone regeneration. These results suggested that PDGF-BB loaded chitosan/CMP sponge was a feasable scaffolding material to grow osteoblast in a three-dimentional structure for transplantation into a site for bone regeneration.

• Journal of Chest Surgery
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• v.35 no.2
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• pp.94-101
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• 2002

All kinds of tissue valves must be pretreated for the inactivation of immunologic properties and the strengthening of tissue before implantation. However, the tissue valves are gradually denatured with the calcification process and they eventually lose their functions. Recent reports have shown the existence of specific calcium binding non collagenous proteins in the calcified area of implanted biomaterials. This experiment was intended to confirm the effect of pretreatment with RGDS(Arg-Gly-Asp-Ser) tetrapeptide on the calcification of subcutaneously implanted bovine pericardium in rats. RGDS tetrapeptide has the same amino acid sequence of attachment site of specific calcium binding non collagenous proteins. Material and Method: All bovine pericardial pieces were fixed with 0.6% glutaraldehyde. The pretreatments were done using 5 different methods, groupI, with normal saline for 60 minutes, groupII, with 0.5% GRSD(Gly-Arg-Scr-Asp) tetrapeptide solution for 60 minutes, group III : with 0.5% RGDS(Arg-Gly-Asp-Ser) tctrapeptide for 30 minutes, group IV ; with 0.5% RGDS for 60 minutes, and group V : with 0.5% RGDS for 120 minutes. The pretreated bovine pericardial pieces were implanted subcutaneously at the abdominal sites of rats. 30 days after the implantation, the implanted bovine pericardial tissue were examined radiologically, biochemically, and histologically to measure the severity of calcification. Result: On the radiological examination, group I ; 68.42$\pm$3.06, group II , 64.25$\pm$5.58 showed significant difference with group III: 48.00$\pm$3.57, group IV; 43.67$\pm$2.31, and group V ; 2.58$\pm$2.47(p<0.05). There was no difference between group I and II(p=0.105). On the biochemical examination, the amount of calcium in group I was , 33.09$\pm$6.59 mg, in group II ; 28.12$\pm$5.50mg, in group III ; 25.42$\pm$7.67mg, in group Ⅵ ; 20.51$\pm$5.11mg, and in group V : 15.43$\pm$4.25mg.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.115-122
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• 2011

Background: The intramural coronary artery has been known as a risk factor for early death after an arterial switch operation (ASO). We reviewed the morphological characteristics and evaluated the early and mid-term results of ASO for patients with an intramural coronary artery. Materials and Methods: From March 1994 to September 15th 2010, 158 patients underwent ASO at Dong-A and Pusan National University Hospitals for repair of transposition of the great arteries and double outlet right ventricle. Among these patients, 14 patients (8.9%) had an intramural coronary artery. Mean age at operation was $13.4{\pm}10.2$ days (4 to 39 days) and mean body weight was $3.48{\pm}0.33$ kg (2.88 to 3.88 kg). All patients except one were male. Eight patients had TGA/IVS and 4 patients had an aortic arch anomaly. Two patients (14.3%) had side-by-side great artery relation, of whom one had an intramural right coronary artery and the other had an intramural left anterior descending coronary artery. Twelve patients had anterior-posterior relation, all of whom had an intramural left coronary artery (LCA). The aortocoronary flap technique was used in coronary transfer in 8 patients, of whom one patient required a switch to the individual coronary button technique 2 days after operation because of myocardial ischemia. An individual coronary button implantation technique was adopted in 6, of whom 2 patients required left subclavian artery free graft to LCA during the same operation due to LCA injury during coronary button mobilization and LCA torsion. Results: There was 1 operative death (7.1%), which occurred in the first patient in our series. This patient underwent an aortocoronary flap procedure for coronary transfer combining aortic arch repair. Overall operative mortality for 144 patients without an intramural coronary artery was 13.2% (19/144). There was no statistical difference in operative mortality between the patients with and without an intramural coronary artery (p>0.1). There was no late death. The mean follow-up duration was $52.1{\pm}43.0$ months (0.5 to 132 months). One patient who had a subclavian artery free graft required LCA stenting 6.5 years after surgery for LCA anastomotic site stenosis. No other surviving patient needed any intervention for coronary problems. All patients had normal ventricular function at latest echocardiography and were in NYHA class 1. Conclusion: The arterial switch operation in Transposition of Great Arteries or Double Outlet Right Ventricle patients with intramural coronary can be performed with low mortality; however, there is a high incidence of intraoperative or postoperative coronary problems, which can be managed with conversion to the individual coronary button technique and a bypass procedure using a left subclavian free graft. Both aortocoronary flap and individual coronary button implantation techniques for coronary transfer have excellent mid-term results.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.247-268
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• 1996

It has been known for a long time that gonadotropins and steroid hormones play a pivotal role in a series of reproductive biological phenomena including the maturation of ovarian follicles and oocytes, ovulation and implantation, maintenance of pregnancy and fetal growth & development, parturition and mammary development and lactation. Recent investigations, however, have elucidated that in addition to these classic hormones, multiple growth factors also are involved in these phenomena. Most growth factors in reproductive organs mediate the actions of gonadotropins and steroid hormones or synergize with them in an autocrine/paracrine manner. The insulin-like growth factor(IGF) system, which is one of the most actively investigated areas lately in the reproductive organs, has been found to have important roles in a wide gamut of reproductive phenomena. In the present communication, published literature pertaining to the intrauterine IGF system will be reviewed preceded by general information of the IGF system. The IGF family comprises of IGF-I & IGF-II ligands, two types of IGF receptors and six classes of IGF-binding proteins(IGFBPs) that are known to date. IGF-I and IGF-II peptides, which are structurally homologous to proinsulin, possess the insulin-like activity including the stimulatory effect of glucose and amino acid transport. Besides, IGFs as mitogens stimulate cell division, and also play a role in cellular differentiation and functions in a variety of cell lines. IGFs are expressed mainly in the liver and messenchymal cells, and act on almost all types of tissues in an autocrine/paracrine as well as endocrine mode. There are two types of IGF receptors. Type I IGF receptors, which are tyrosine kinase receptors having high-affinity for IGF-I and IGF-II, mediate almost all the IGF actions that are described above. Type II IGF receptors or IGF-II/mannose-6-phosphate receptors have two distinct binding sites; the IGF-II binding site exhibits a high affinity only for IGF-II. The principal role of the type II IGF receptor is to destroy IGF-II by targeting the ligand to the lysosome. IGFs in biological fluids are mostly bound to IGFBP. IGFBPs, in general, are IGF storage/carrier proteins or modulators of IGF actions; however, as for distinct roles for individual IGFBPs, only limited information is available. IGFBPs inhibit IGF actions under most in vitro situations, seemingly because affinities of IGFBPs for IGFs are greater than those of IGF receptors. How IGF is released from IGFBP to reach IGF receptors is not known; however, various IGFBP protease activities that are present in blood and interstitial fluids are believed to play an important role in the process of IGF release from the IGFBP. According to latest reports, there is evidence that under certain in vitro circumstances, IGFBP-1, -3, -5 have their own biological activities independent of the IGF. This may add another dimension of complexity of the already complicated IGF system. Messenger ribonucleic acids and proteins of the IGF family members are expressed in the uterine tissue and conceptus of the primates, rodents and farm animals to play important roles in growth and development of the uterus and fetus. Expression of the uterine IGF system is regulated by gonadal hormones and local regulatory substances with temporal and spatial specificities. Locally expressed IGFs and IGFBPs act on the uterine tissue in an autocrine/paracrine manner, or are secreted into the uterine lumen to participate in conceptus growth and development. Conceptus also expresses the IGF system beginning from the peri-implantation period. When an IGF family member is expressed in the conceptus, however, is determined by the presence or absence of maternally inherited mRNAs, genetic programming of the conceptus itself and an interaction with the maternal tissue. The site of IGF action also follows temporal (physiological status) and spatial specificities. These facts that expression of the IGF system is temporally and spatially regulated support indirectly a hypothesis that IGFs play a role in conceptus growth and development. Uterine and conceptus-derived IGFs stimulate cell division and differentiation, glucose and amino acid transport, general protein synthesis and the biosynthesis of mammotropic hormones including placental lactogen and prolactin, and also play a role in steroidogenesis. The suggested role for IGFs in conceptus growth and development has been proven by the result of IGF-I, IGF-II or IGF receptor gene disruption(targeting) of murine embryos by the homologous recombination technique. Mice carrying a null mutation for IGF-I and/or IGF-II or type I IGF receptor undergo delayed prenatal and postnatal growth and development with 30-60% normal weights at birth. Moreover, mice lacking the type I IGF receptor or IGF-I plus IGF-II die soon after birth. Intrauterine IGFBPs generally are believed to sequester IGF ligands within the uterus or to play a role of negative regulators of IGF actions by inhibiting IGF binding to cognate receptors. However, when it is taken into account that IGFBP-1 is expressed and secreted in primate uteri in amounts assessedly far exceeding those of local IGFs and that IGFBP-1 is one of the major secretory proteins of the primate decidua, the possibility that this IGFBP may have its own biological activity independent of IGF cannot be excluded. Evidently, elucidating the exact role of each IGFBP is an essential step into understanding the whole IGF system. As such, further research in this area is awaited with a lot of anticipation and attention.

• Herbal Formula Science
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• v.16 no.1
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• pp.65-78
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• 2008

Objectives : this study was to access the effect of Hyeonggaeyeongyotang water extracts, a polyherbal formula has been used as folk medicine, on the fertility and early embryonic development of male and female Wistar rats when administered by oral gavage. Methods : In male rats, Hyeonggaeyeongyotang extract were dosed 4 weeks before pairing and 2 weeks after mating including the mating periods up to termination after necropsy of the majority of the females. In female rats, they were dosed 2 weeks before pairing, and from Day 0 to Day 7 of gestation. This study was conducted in accordance with the recommendations of the KFDA Guideline [2005-60] for Detection of Toxicity to Reproduction for Medicinal Products. Results: 1. No Hyeonggaeyeongyotang extract treatment-related changes on the clinical signs and mortalities, the Food consumptions, the Body weights and gains were demonstrated in all dosed levels tested in this study except for 500ml/kg-dosing male group in which a significant(p<0.05) increase of body gains was detected during day 0-7 after dosing. 2. No Hyeonggaeyeongyotang extract treatment-related changes on the pre-coital intervals, the estrus cycles, the mating index, conception rate and fertility index were demonstrated in all dosed levels tested in this study. 3. No Hyeonggaeyeongyotang extract treatment-related gross findings on reproductive organs, the weights of reproductive organs, histopathological findings on reproductive organs, the corpora lutea number, implantation site number, live fetus number, number of resorpted embryo and pre-and post-implatation loss were demonstrated in all dosed levels tested in this study. Conclusions : Base on the results, it is considered that the NOAEL (No-Observed-Adverse-Effect Level) for fertility and early embryonic development toxicity of Hyeonggaeyeongyotang extract was under 2000ml/kg/day in Wistar male and female rats because there no treatment-related changes on the fertility and early embryonic developmental index were demonstrated in all dosed levels tested.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.117-129
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• 1989

The commercial availability of processed heterogenous bone has provided the surgeons with almost unlimited supply, avoidance of additional operation and prevention of the postoperative complications. In addition to these merits, unnecessary bone bank, easy availibility and storage have been achieved. The purpose of this study was to compare and examine the healing capacity of Kiel bone, Pyrost and Osteovit which used as the processed heterografts for the reconstruction of bony defect. Twenty rabbits weighing about 1.7-2.0 Kg were selected and divided into two groups. In experimental group A, the left mandibular defect was allowed to fill with blood, and the right defect was filled with Kiel bone. In experimental group B, the left defect was grafted with Pyrost, and the right with Osteovit. The experimental animals were sacrified after 1, 2, 4 and 8 weeks and the grafted site was studied histologically. To evaluate the strength of healed bone, 2 rabbits from each experimental group and a nonoperated control were sacrified at the 6th week after implantation and used for biometric testing on universal testing machine. The results obtained were as follows : 1. It was considered that these heterogenous bone grafts has feeble or absent immunogenicity since all of them appeared to evoke little inflammatory or forign body reaction. 2. In all experimental groups, new bone formation began from the adjacent region of host bone and extended progressively into the defect sites. New bone was partly formed within the intertrabecular space of the implant and gradually united with the bone that formed at the margin of the host bone. 3. With Pyrost bone formation was rapid and prominent comparing with other graft materials. 4. Osteovit was begun to be absorbed from 2 weeks, and Kiel bone from 4 weeks, however Pyrost was remained to be intact until the end of 8 weeks. 5. As the results of tensile test, the mean values of maximum tensile stress were 1.11${\uparrow}$ $Kgf/mm^{2}$ in Pyrost implanted specimens, 0.85 $Kgf/mm^{2}$ in Osteovit, 0.42 $Kgf/mm^{2}$ in Kiel bone, 0.66 $Kgf/mm^{2}$ in blood filled specimens and 1..13 $Kgf/mm^{2}$ in control. These results indicate that heterogenous bones grafted have little antigenicity to the host tissue, and that they mediate effectively osteoconduction by providing the scaffold for the bone formation. Pyrost and Osteovit appeared to be suitable for the clinical use.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.281-285
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• 2011

In the present study, we identified differentially methylated region (DMR) upstream of Dnmt1o and Dnmt1s gene in early porcine embryos. Porcine Dnmt1o had at least one DMR which was located between -530 bp to -30 bp upstream from transcription start site of the Dnmt1o gene. DNA methylation analyses of Dnmt1o revealed the DMR to be hypomethylated in oocytes, whereas it was highly methylated in sperm. Moreover, the DMR upstream of Dnmt1o was gradually hypermethylated from oocytes to two cells and dramatically changed in the methylation pattern from four cells to BL stages in an in vivo. In an IVF, the methylation status in the DMR upstream of Dnmt1o was hypermethylated from one cell to eight cells, but demethylated at the Morula and BL stages, indicating that the DNA methylation pattern in the Dnmt1o upstream ultimately changed from stage to stage before the implantation. Next, to elucidate whether DNA methylation status of Dnmt1s upstream is stage-by-stage changed in during porcine early development, we analyzed the dynamics of the DNA methylation status of the Dnmt1s locus in germ cell, or one cell to BL cells. The Dnmt1s upstream was highly methylated in one and eight cells, while less methylated in two, four, morula, and BL cells. Taken together, our data demonstrated that DNA methylation and demethylation events in upstream of Dnmt1o/Dnmt1s during early porcine embryos dramatically occurred, and this change may contribute to the maintenance of genomewide DNA methylation in early embryonic development.

• Journal of Periodontal and Implant Science
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• v.33 no.1
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• pp.13-26
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• 2003

Periodontal regeneration therapy with bone-substituting materials has gained favorable clinical efficacy by enhancing osseous regeneration in periodontal bony defect. As bone-substituting materials, bone powder, calcium phosphate ceramic, modified forms of hydroxyapatite, and hard tissue replacement polymer have demonstrated their periodontal bony regenerative potency. Bone-substituting materials should fulfill several requirements such as biocompatibility, osteogenecity, malleability, biodegradability. The purpose of this study was to investigate biocompatibility, osteo-conduction capacity and biodegradability of $Na_2O$, $K_2O$ added calcium metaphosphate(CMP). Beta CMP was obtained by thermal treatment of anhydrous $Ca_2(H_2PO_4)_2$. $Na_2O$ and $K_2O$ were added to CMP. The change of weight of pure CMP, $Na_2O$-CMP, and $K_2O$-CMP in Tris-buffer solution and simulated body fluid for 30 days was measured. Twenty four Newzealand white rabbits were used in negative control, positive control(Bio-Oss), pure CMP group, 5% $Na_2$-CMP group, 10% $Na_2O$-CMP goup, and 5% $K_2O$-CMP group. In each group, graft materials were placed in right and left parietal bone defects(diameter 10mm) of rabbit. The animals were sacrificed at 3 months and 6 months after implantation of the graft materials. Degree of biodegradability of $K_2O$ or $Na_2O$ added CMP was greater than that of pure CMP in experimental condition. All experimental sites were healed with no clinical evidence of inflammatory response to all CMP implants. Histologic observations revealed that all CMP grafts were very biocompatible and osseous conductive, and that in $K_2O$-CMP or $Na_2O$-CMP implanted sites, there was biodegradable pattern, and that in site of new bone formation, there was no significant difference between all CMP group and DPBB(Bio-Oss) group. From this result, it was suggested that all experimental CMP group graft materials were able to use as an available bone substitution.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.1
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• pp.59-68
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• 2010

Recently, dental implants extensively inserted on edentulous area show highly clinical success rate. However, clinicians cannot exclude the possibility of failure and it often unexpectively occures. Many possible factors associated with failure of dental implants have been reported but controversy exists over the extent to them. In this study, we collected 212 patients who had been inserted 358 dental implants on mandibular premolar and molar area from 2005 to 2006. The survival rate of fixtures was recorded according to age of patients, implantation site, implant system, diameter and length of fixtures. Multi-variable analysis using SPSS chi-square test was operated to verify relation of each factors and survival rates. Accumulative survival rate was 98.3% for 3 years. Only diameter of fixtures was related to the implant survival rate. This may be thought that wider fixtures had been chosen to rescue implants or used in sites of poor bone quality. Further continuous study will be needed for direct guidance associated with survival rate of implants.