• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.199-216
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• 2005

치주치료의 가장 중요한 목적은 상실된 치주조직의 형태적, 기능적 재건이다. 법랑기칠 단백질 유도체(enamel matrix derivative: EMD)는 치주 병소에 사용시 상피세포의 증식을 억제하며 치주인대 및 백악아세포를 활성화시켜 무세포성 백악질 및 치주인대와 골조직의 생성을 유도한다고 보고되고 있다. 또한 법랑기질 단백칠 유도체는 골모세포의 증식 및 분화를 촉진시키며 alkaline phosphatase의 활성 및 mineralized nodule의 형성을 촉진시킨다고 보고되고 있다. 이에 본 연구에서는 토끼 두개골 결손부에 법랑기질 단백질 유도체와 이종골 이식재를 이식한 후 골밀도를 방사선학적으로 분석하고, 신생골 형성 및 주변 조직 반응을 조직학적으로 관찰, 평가하고자 하였다. 토끼 두개골에 6mm trephine bur(외경 8mm)를 이용하여 경뇌막에 손상을 주지 않도록 하면서 4개의 결손부를 형성하였다. 아무것도 이식하지 않은 군을 음성 대조군으로, 이종골 이식재 ($Bio-Oss^{(R)}$, Geistlich, Wolhusen, Switzerland)을 이식한 군을 양성 대조군으로 설정하였다. 법랑기질 단백질 유도체 ($Emdogain^{(R)}$, Biora, Inc., Sweden)만 이식한 군과 법랑기질 단백질 유도체와 이종골 이식재를 혼합하여 이식한 군을 설험군으로 설정하였다. 각각의 재료를 이식한 후 비흡수성 차폐막 ($Tefgen^{(R)}$, Lifecore Biomedical, Inc., U.S.A.)을 위치시키고 흡수성 봉합사로 일차봉합을 시행하였다. 각 군당 술 후 1, 2, 4주의 치유기간을 설정하였다. 동물을 희생시킨 후 두개골을 절제하여 먼저 방사선학적인 골밀도측정을 시행한 후 10% formalin에 고정한 후 통법에 따라 조직표본을 제작하여 광학현미경으로 관찰하였다. 1. 방사선학적인 평가에서 1, 2, 4주에 대조군과 법랑기질 단백질 유도체만 이식한 군과 비교해 이종골 이식재만 이식한 군과 이종골 이식재에 법랑기질 단백질 유도체를 이식한 군에서 더 큰 골의 밀도를 보이고 있었다 (P<0.01). 하지만, 동일한 시기에 대조군과 법랑기질 단백질 유도체만 이식한 군과의 차이는 발견할 수 없었으며 (P>0.05), 이종골 이식재만 이식한 군과 이종골 이식재에 법랑기질 단백질 유도체를 이식한 군의 차이 또한 발견할 수 없었다 (P>0.05). 2. 조직학적인 평가에서 1, 2, 4주에 대조군과 법랑기질 단백질 유도체만 이식한 군과 비교해 이종골 이식재만 이식한 군과 이종골 이식재에 법랑기질 단백질 유도체를 이식한군에서 골의 형성이 더 진행됨을 알 수 있었다. 법랑기질 단백질 유도체만 이식한 군이 대조군보다 2주에서 더 많은 신생골을 볼 수 있었으며, 이종골 이식재에 법랑기질 단백질 유도체를 이식한 군이 이종골 이식재만 이식한 군보다 1, 2주에서 더 많은 신생골을 관찰할 수 있었다. 이상의 결과에서 법랑기질 단백질 유도체는 토끼 두개골 결손부 치유단계에서 초기 골 형성을 촉진하는 것으로 사료되며 골 이식시에 법랑기질 단백질 유도체를 적용하는 것은 유용한 술식으로 사료된다.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.42-42
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• 2002

본 연구는 한국 재래산양의 핵이식에 있어서 공여핵은 귀세포를, 수핵난자는 소 및 돼지의 난포란을 이용하여 핵이식을 실시하여 복제수정란의 체외발달율과 이종간의 핵이식 가능성을 검토하였다. 공여핵은 재래산양의 귀세포를 채취하여 10% FBS 가 첨가된 TCM-199 배양액으로 체외 배양을 실시하여 monolayar Confluent 형성후 0.25% Trypsin-EDTA을 처리하여 계대배양을 실시하였다. (중략)

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.180-192
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• 2007

Background: As determined from the recent investigations of discordant cardiac xenotransplantation, hyperacute rejection occurs mainly at the endothelial cells in donor microvascular systems, but this does not occur at cardiac valve leaflets or at medium-to-large caliber vessels. On the basis of this background, this study was performed to look into the biocompatibility for transplantation of a middle or large diameter xenogenic blood vessel by conducting xenogenic arterial transplantation with the carotid artery in a pig-to-goat model. Material and Method: The experimental group was composed of 10 pairs of pig-to-goat combinations. They were divided into each period of 1 week, and 1, 3, 6 and 12 months. Four carotid artery grafts obtained through collection of the bilateral carotid arteries from two pigs were preserved at $-70^{\circ}C$ without other treatment, and then they were transplanted into the bilateral carotid arteries of two goats. Doppler ultrasonography was done on a periodic basis after transplantation to evaluate the patency of the grafted blood vessel. At the ends of a predetermined period, the grafts were explanted from the goats and they underwent gross examination. Hematoxylin-eosin and Masson's trichrome staining were conducted. In addition, in order to examine the immunological rejection of the grafted xenogenic blood vessel, immunohistochemical staining was conducted with T-lymphocyte indicator and von Willebrand factor. Result: Two goats at the each one-week period and the one-year period died during the experimental period because of a reason unrelated to the experimental procedure, and the remaining 8 goats survived until the end of each experiment period. On Doppler ultrasonography, unilateral carotid artery occlusion was found in a goat, whose period was specified as 3 months, among the 8 survived goats. However, the vascular patency was maintained well and there was no graft that formed aneurysms in the other goats. On gross examination, the region of vascular anastomosis was preserved well, and calcification of the grafted blood vessel was not shown. Histologically, the endothelial cells of the graft disappeared one week after transplantation, and then there was progressive spread of the recipients' endothelial cells from the anastomotic site. The reendothelialization occurred over the whole graft at one month after transplantation. The neointimal thickening and adventitial inflammation became severe by 3 months after transplantation, but this lessened at 6 months and 12 months, respectively. The rate of CD3 positive cells was very low among the infiltrated inflammatory cells. Conclusion: The fresh-frozen xenogenic artery kept its patency without being greatly influenced by xenogenic immune reaction.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.297-306
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• 2004

Current artificial heart valves have several disadvantages, such as thromboembolism, limited durability, infection, and inability to grow. The solution to these problems would be to develop a tissue-engineered heart valves containing autologous cells. The aim of this study was to optimize the protocol to obtain a porcine acellular matrix and seed goat autologous endothelial cells on it, and to evaluate the biological responses of xenograft and xeno-autograft heart valves in goats. Material and Method: Fresh porcine pulmonic valves were treated with one method among 3 representative decellularization protocols (Triton-X, freeze-thawing, and NaCl-SDS). Goat venous endothelial cells were isolated and seeded onto the acellularized xenograft leaflets. Microscopic examinations were done to select the most effective method of decellularizing xenogeneic cells and seeding autologous endothelial cells. Two pulmonic valve leaflets of. 6 goats were replaced by acellularized porcine leaflets with or without seeding autologous endothelial cells while on cardiopulmonary bypass. Goats were sacrificed electively at 6 hours, 1 day, 1 week, 1 month, 3 months, and 6. months after operation. Morphologic examinations were done to see the biological responses of replaced valve leaflets. Result: The microscopic examinations showed that porcine cells were almost completely removed in the leaflets treated with NaCl-SDS. The seeded endothelial cells were more evenly preserved in NaCl-SDS treatment. All 6 goats survived the operation without complications. The xeno- autografts and xenografts showed the appearance, the remodeling process, and the cellular functions of myofibroblasts, 1 day, 1 month, and 3 months after operation, respectively. They were compatible with the native pulmonary leaflet (control group) except for the increased cellularity at 6 months. The xenografts revealed the new endothelial cell lining at that time. Conclusion: Treatment with NaCl-SDS was most effective in obtaining decellularized xenografts and facilitate seeding autologous endothelial cells. The xenografts and xeno-autografts were repopulated with myofibroblasts and endothelial cells in situ serially. Both of grafts served as a matrix for a tissue engineered heart valve and developed into autologous tissue for 6 months.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.223-228
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• 2008

Background: The aim of this study is to confirm that peripheral blood sampling for measuring of serum immunoglobulin can predict immunological changes after xenograft implantation. Material and Method: Between March 2006 and January 2007, 19 patients were enrolled (10 xenograft implantation group, 9 control group). Through 3 peripheral blood samples, we measured changes in serum immunoglobulin G and M levels preoperatively, and 2 and 10 days postoperatively. Result: In both groups, serum immunoglobulin levels showed similar changes-they decreased 2 days postoperatively, then increased up to the baseline levels 10 days postoperatively. However, this postoperative change of immunoglobulin G and M was not significantly different in absolute value or pattern between the 2 groups (Ig G; p-value=0.393, Ig M; p-value=0.193). Conclusion: We could not predict immunological changes after xenograft implantation by measuring serum immunoglobulin levels by simple blood sampling. Direct checking of ${\alpha}$-Galactose antibody may confirm an immunological reaction after xenograft implantation.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.1-7
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• 2007

Backgound: It has been shown that the endothelium of cardiac valves and adjacent great vessels have a reduced immune reaction compared to other vessels. We investigated the clinical feasibility of using immunologically untreated xenogenic valves, in a pig-to-goat pulmonary valve conduit implantation model. Material and Method: Porcine pulmonary valve conduits were prepared without specific immunologic treatment and implanted into the right ventricular outflow tract of goats while undergoing cardiopulmonary bypass. Two goats each were assigned to the following observation time intervals: one day, one week, three months, six months and twelve months. Echo-cardiographic examinations were performed prior to sacrifice of the goat to evaluate pulmonary valve function. After the xenograft specimens were retrieved, histological changes were evaluated microscopically. Result: Ten of the twelve animals survived the predetermined observation time intervals. Aneurysmal dilatations, of the anterior wall of the implanted pulmonary artery, were observed at each of three and twelve month-survival animals. A variable degree of pulmonary valve regurgitation was observed on echocardiography. However, valve stenosis, thrombotic occlusion and vegetation were not seen. Microscopically, the nuclei of the donor tissue disappeared as a result of pyknosis and karyolysis; however the three components of the implanted xenografts (the pulmonary artery, the valve and the infundibulum) were gradually replaced by host cells over time, while maintaining their structural integrity. Conclusion: Immunologically untreated xenogenic pulmonary valve conduits were replaced by host cells with few observed clinical problems in a pig to goat pulmonary valve implantation model. Therefore, they might be an alternative bioprosthesis option.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.1-4
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• 1999

Background: The transplantation of organs between phylogenetically disparate or harmonious species has invariably failed due to the occurrence of hyperacute rejection or accerelated acute rejection. But, concordant cardiac xenograft offer us an opportunity to study xenotransplantation in the absence of hyperacute rejection. Current therapeutics for the prolongation of survival of rodent concordant xenotransplantation are not ideal with many regimens having a high mortality rate. Cyclosporine A & Mycophenolate Mofetil are new immunosuppresive agent which has been shown to be effective at prolonging survival of allograft, as purine synthesis inhibitor. Material and Method: We used white mongrel rats as recipient and mice as donor, divided 4 groups(n=6), control group(Group 1) has no medication or pretreatment, Group 2 has splenectomy as pretreatment 7∼10 days before transplantation, Group 3 has Cyclosporine A treatment group, Group 4 has combined treatment of Cyclosporine A & Mycophenolate Mofetil(RS 61443). We compared survival time. Reuslt: We can't find significant difference of survival time between each groups. Conclusion: We concluded that rejection of cardiac xenograft was different from rejection of allograft, and new immunossuppresive Agent(Mycophenolate Mofetil, Cyclosporine A) was not effective for prolongation of survival time after cardiac xenograft.

• Journal of Chest Surgery
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• v.37 no.5
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• pp.391-400
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• 2004

Xenotransplantation in discordant species results in immediate and irreversible hyperacute rejection due to natural antibodies, IgM. With this, antibody depletion is one option to reduce hyperacute rejection, we investigated the effect of PCPP (postcentrifugal plasmapheresis) on the depletion of natural antibodies and the effect of antibody titer on xenograft survival. Material and Method: Outbred swines (n=4) weighing 10∼20 kg were used as donors and mongrel dogs (n=4) weighing 25∼30 kg were used as recipients. Recipient canines underwent plasmapheresis (COBE TPE Laboratories, Lakewood. CO, USA). Pre-transplantation PCPP was peformed on day －2 and day 0. There were three groups (Group 0: no PCPP, Group 1: 1 pla sma-volume (PV) at day －2 and 2 PV at day 0, Group 2: 2 PV at day －2 and 2 PV at day 0). A swine heart was heterotopically transplanted into a recipient's abdominal infrarenal aorta and inferior vena cava. Mean percent depletion of total IgM and IgG in plasma of the recipients was calculated. Serum albumin, electrolyte, complement activity and coagulation factors were measured. Histopathologic examination of heart specimens was performed. Result: Mean percent depletion of IgM and IgG were 95.7$\pm$1.2%, 80.5$\pm$2.4% in the group 2 at the end of PCPP. The percent depletion of serum albumin concentration was decreased from 2.8 to 1.4 g/㎗ in the group 1 and 3.0 to 1.5 g/㎗ in the group 2. Complement hemolytic activity was decreased in group 1 and 2, but returned to normal level within 24 hours. Complement hemolytic activity was reduced to 10% of pre-PCPP level in group 2. Serum fibrinogen decreased to 20% or less and was recovered within 24 hours in group 2. Antithrombin III decreased but less than fibrinogen. PT and aPTT were sometimes but not always prolonged during plasmapheresis. After plasmapheresis, PT and aPTT were prolonged beyond the measurable level. D-dimer was not found during PCPP, but appeared and maintained from 10 minutes after trasplantation. Graft Survival time was 5 min in group 0, and it was 90$\pm$0 min in the group 2. Histopathologic changes were more typically characterized by edema, hemorrhages, thrombosis in all groups at the end of experiment. Conclusion: PCPP effectively removed immuoglobulins and reduced the titer of natural antibodies, as a result, significantly prololonged swine heart xenograft survival.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.482-491
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• 2004

Background: The xenogenic or allogenic valves after in Vitro repopulation with autologous cells or in vivo repo-pulation after acellularization treatment to remove the antigenicity could used as an alternative to synthetic polymer scaffold. In the present study, we evaluated the process of repopulation by recipient cell to the acellu-larized xenograft treated with NaCl-SDS solution and grafted in the right ventricular outflow tract. Material and Method: Porcine pulmonary valved conduit were treated with. NaCl-SDS solution to make the grafts acellularized and implanted in the right ventricular outflow tract of the goats under cardiopulmonary bypass. After evaluating the functions of pulmonary valves by echocardiography, goats were sacrificed at 1 week, 1 month, 3 months, 6 months, and 12 months after implantation, respectively. After retrieving the implanted valved conduits, histopathologic examination with Hematoxylin-Eosin, Masson' trichrome staining and immunohistochemical staining was performed. Result: Among the six goats, which had been implanted with acellularized pulmonary valved conduits, five survived the expected time period. Echocardiographic examinations for pulmonary valves revealed good function except mild regurgitation and stenosis. Microscopic analysis of the leaflets showed progressive cellular in-growth, composed of fibroblasts, myofibroblasts, and endothelial cells, into the acellularized leaflets over time. Severe inflammatory respon-se was detected in early phase, though it gradually decreased afterwards. The extracellular matrices were regenerated by repopulated cells on the recellularized portion of the acellularized leaflet. Conclusion: The acellularized xenogenic pulmonary valved conuits were repopulated with fibroblasts, myofibroblasts, and endothelial cells of the recipient and extracellullar matrices were regenerated by repopulted cells 12 months after the implantation. The functional integrity of pulmonary valves was well preserved. This study showed that the acellularized porcine xenogenic valved conduits could be used as an ideal valve prosthesis with long term durability.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.189-193
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• 1995

The authors reviewed 49 cases(48 patients) of benign bone tumor who had surgical treatment with xenograft at department of orthopedic surgery, Seoul National University Hospital from May, 1980 to May, 1994. Materials consist of 21 males and 27 females. The mean age at operation was 20.1 years(range : 4 -55 years) and the mean follow up period was 25.4 months(range : 7 - 85 months). We did xenograft only in 34 cases and xenograft mixed with autograft in 15 cases(14 cases, from ilium, 1 case from femur). The used materials for xenograft were $Lubboc^{(R)}$ in 29 cases, $Surgibone^{(R)}$ in 17 cases and $Pyrost^{(R)}$ in 3 cases. The average durations when bony union was achieved in radiograph were 13.8 weeks in whole cases, 12.5 weeks(range : 8 - 24 weeks) in $Lubboc^{(R)}$ graft cases and 15.7 weeks(range : 6 - 24 weeks) in $Surgibone^{(R)}$ graft cases. The tumor recurred in 4 cases, 1 case was recurred giant cell tumor at distal femur treated with mixed auto and $Lubboc^{(R)}$ graft and 2 cases were large cystic lesions at the proximal humerus diagnosed as simple bone cyst and at distal tibia diagnosed as fibrous dysplasia treated with $Surgibone^{(R)}$ graft and 1 case was aneurysmal bone cyst of the proximal tibia treated with $Lubboc^{(R)}$ graft. Wound infection occurred in 1 case. More transfusion was done in the cases that the lesion was larger than 5cm, the lesions were in the ilium or femur and the cases that were treated with mixed with autograft. This study implies that benign bone tumor is successfully treqated with curettage and xenograft or xenograft mixed with autograft. And also this method will reduce morbidity of donor site, intraoperative bleeding and post-transfusion complications.