• Journal of Radiation Protection and Research
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• 제42권3호
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• pp.146-153
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• 2017

Background: Acute radiation syndrome (ARS) primarily refers to damage to the hematopoietic system, myeloid system, and gastrointestinal (GI) system caused by radiation exposure. Such damage progresses to become life-threatening. In particular, as the syndrome develops very rapidly-within several hours from radiation exposure-prompt and accurate diagnosis and treatment are needed, as is further research into appropriate diagnostic and treatment modalities. Materials and Methods: Minipigs, which display human-like properties, underwent whole-body irradiation at 2 or 4 Gy (doses causing hematopoietic ARS) or at higher doses of 7 or 12 Gy. Changes in the blood cells and clinical symptoms were analyzed and we performed a necropsy when the animals succumbed to ARS. Results and Discussion: The minipig irradiated with 2 Gy showed a decrease in white blood cells, including neutrophils, lymphocytes, and platelets in the early stages. However, the blood cell counts gradually increased and returned to normal values. The minipig irradiated with 4 Gy succumbed due to hematopoietic ARS. In contrast, the minipigs irradiated with 7 or 12 Gy exhibited clinical symptoms of combined GI damage and hematopoietic syndrome. Moreover, a characteristic pattern of platelet changes was observed in the 7 and 12 Gy irradiated minipigs. Conclusion: The changes in the platelet count caused by radiation exposure observed in minipigs, which are hematologically and pathohistologically similar to humans, suggest that they can be used as a novel diagnostic criterion.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2007년도 제47회 종합학술대회 연제초록
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• pp.154-155
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• 2007

• Journal of Radiation Protection and Research
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• 제42권4호
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• pp.189-196
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• 2017

Background: The effects of radiation on tissues vary depending on the radiation type. In this study, a minipig model was used to compare the effects of ${\beta}$-rays from $^{166}Ho$ and ${\gamma}$-rays from $^{60}Co$ on the skin. Materials and Methods: In this study, the detrimental effects of ${\beta}$- and ${\gamma}$-irradiation on the skin were assessed in minipigs. The histopathological changes in the skin from 1 to 12 weeks after exposure to 50 Gy of either ${\beta}$- (using $^{166}Ho$ patches) or ${\gamma}$- (using $^{60}Co$) irradiation were assessed. Results and Discussion: The skin irradiated by ${\beta}$-rays was shown to exhibit more severe skin injury than that irradiated by ${\gamma}$-rays at 1-3 weeks post-exposure; however, while the skin lesions caused by ${\beta}$-rays recovered after 8 weeks, the ${\gamma}$-irradiated skin lesions were not repaired after this time. The observed histopathological changes corresponded with gross appearance scores. Seven days post-irradiation, apoptotic cells in the basal layer were detected more frequently in ${\beta}$-irradiated skin than in ${\gamma}$-irradiated skin. The basal cell density and skin thickness gradually decreased until 4 weeks after ${\gamma}$- and ${\beta}$- irradiation. In ${\beta}$-irradiated skin lesions, and the density and thickness increased sharply back to control levels by 6-9 weeks. However, this was not the case in ${\gamma}$-irradiated skin lesions. In ${\gamma}$-irradiated skin, cyclooxygenase-2 (COX-2) was shown to be expressed in the epidermis, endothelial cells of vessels, and fibroblasts, while ${\beta}$-irradiated lesions exhibited COX-2 expression that was mostly limited to the epidermis. Conclusion: In this study, ${\beta}$-rays were shown to induce more severe skin injury than ${\gamma}$-rays; however, the ${\beta}$-rays-induced injury was largely repaired over time, while the ${\gamma}$-rays-induced injury was not repaired and instead progressed to necrosis. These findings reveal the differential effects of ${\gamma}$- and ${\beta}$-irradiation on skin and demonstrate the use of minipigs as a beneficial experimental model for studying irradiation-induced skin damage.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.53-64
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• 2007

The aim of this study was to examine the possibility of periodontal ligament regeneration when autotransplantation was used by the periodontal ligament fibroblasts cultured on the acellular dermal matrix in teeth without a periodontal ligament. One minipig was used in this study. The mandibular and maxillary permanent incisors were ex-tracted for the culture of the periodontal ligament cells. The roots of the unextracted teeth were classified into a positive control group, in which the normal periodontal ligament was preserved. The roots of the extracted teeth were divided into the following two groups: The negative control group, in which the periodontal ligament had been removed and the acellular dermal matrix was not applied; and an experimental group, in which the periodontal ligament had been removed and periodontal ligament fibroblast cultured on an acellular dermal matrix was applied. The prepared teeth were transplanted, and completely submerged using physical barrier membranes. The animal was sacrificed 4 weeks after the autotransplant. The transplanted teeth were examined histologically. In this study, the periodontal ligament was normal in the positive control group, and ankylosis was discovered on the denuded root surface in the negative control group. Periodontal ligament-like connective tissue was found adjacent to the denuded root and the new cementum-like layer of hard tissue was formed in the experimental group. These results suggest that the periodontal ligament fibroblasts cultured on the acellular dermal matrix may play a role in regenerating the periodontal ligament-like tissue with new cememtum-like tissue formation.

• Reproductive and Developmental Biology
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• 제36권1호
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• pp.79-85
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• 2012

Minipigs are regarded as one of the most important laboratory animal in that anatomical and physiological properties are similar to human and their reproduction efficiency is relatively higher compared to other large animal species. Particularly, several diseases that cannot be mimicked in rodent models are successfully occurred or induced in pig models therefore it has been interested in a valuable model for human diseases. Pigs are also 'standard' species in xenotransplantation research. To maximize experimental outcome using minipigs, establishment and management of proper animal facility, right animal husbandry and control of pathogens are very important. In this review, we summarized several international guidelines related with minipigs published by several companies or governments and discuss optimal conditions for providing informative ideas to the researchers who want to use minipigs in their future studies.

• Reproductive and Developmental Biology
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• 제39권3호
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• pp.59-67
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• 2015

동물의 장기를 인간에게 이식하게 되면 초급성거부반응(Hyperacute rejection, HAR)이 일어난다. 초급성거부반응은 면역계의 구성요소 중 보체(complement)에 의해 일어나는 거부반응으로 돼지의 혈관세포 표면에 있는 $Gal{\alpha}$(1,3)Gal 당분자에 인간의 항체가 즉각 반응하기 때문에 일어나며, ${\alpha}1,3$-galactosyltransferase(${\alpha}1,3$-GT) 유전자는 돼지 혈관세포 표면의 $Gal{\alpha}$(1,3)Gal 당분자 생성에 관여한다. 따라서 인간에게 돼지의 장기를 이식하기 위해서는 ${\alpha}1,3$-galactosyltransferase 유전자를 제거하는 것이 필요한 것으로 알려져 있다. 본 연구실의 이전 연구에서, 시카고 미니돼지 귀체세포에서 상동 재조합(Homologous recombination)을 통해 ${\alpha}1,3$-galactosyltransferase 유전자가 제거된 체세포를 개발한 바 있으며, 이 체세포를 통하여 ${\alpha}1,3$-GT 유전자가 제거된 돼지도 생산된 바 있다. 본 연구에서는, human serum 처리 시 돼지 세포를 보호해 준다고 보고되고 있는 human complement regulator인 human Decay-accelerating factor(hDAF)와 human ${\alpha}1,2$-fucosyltransferase(hHT)유전자를 ${\alpha}1,3$-GT 유전자 위치에 gene targeting하여 동시에 hDAF와 hHT가 발현하는 체세포를 개발하였다. Knock-in vector는 hDAF와 hHT 두 유전자가 발현할 수 있도록 IRES로 연결하였으며, ${\alpha}1,3$-GT 유전자의 start codon을 이용하여 발현할 수 있도록 구축하였다. 구축한 vector는 electroporation을 통해 미니 돼지 체세포에 도입하였으며, PCR 결과, ${\alpha}1,3$-GT 유전자 위치에서 상동 재조합이 일어났음을 확인하였다. Positive-negative 선별 방법을 통해 얻은 gene targeting 된 체세포는 RT-PCR에 의해 hDAF와 hHT 유전자의 발현이 확인되었으며, 대조군(NIH minipig)에 비해 ${\alpha}1,3$-GT 유전자의 발현이 감소하였다. 또한 이들 세포에 100% human complement serum을 처리하였을 때 knock-in 세포가 대조군에 비해 30% 정도 더 높은 생존율을 보였다. 따라서 개발된 체세포는 이종간 장기이식을 위한 돼지 생산과 함께 이를 이용한 이종간의 장기 이식 시 초급성 거부반응을 억제하는 데 사용될 수 있을 것으로 생각된다.

• 한국수정란이식학회지
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• 제32권4호
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• pp.305-310
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• 2017

Miniature pig (minipig) has been considered as an important laboratory animal in the developmental biotechnology researches with respect to xenotransplantation, stem cell, somatic cell nuclear transfer and embryo transfer. Given that the laboratory minipigs are normally housed at an indoor facility, they pass the time with lying or sleeping unless it is feeding time. Therefore, it is necessary to provide environmental enrichments to satisfy their innate needs and to lessen atypical behaviors caused by stress, on the purpose of welfare. We quantitatively investigated the type of preferable enrichment for the laboratory minipigs as well as its effect on their daily life. They presented a great interest to the pliable pail but a rapid loss of attraction to non-preferable enrichments. When the daily life of the single housed minipigs was quantified based on duration of playing or resting, they were more actively engaged in lively activities in the presence of enrichments. In addition, the provision of enrichments could effectively alleviate the conflicts during group housing when new pen mate was introduced, resulting in reduction of wound cases. We believe the considerations of animal welfare are essential to the conduct of better research because animals in the non-stressful environment will be more physiologically stable and provide more reliable results in the animal experiments.

• Journal of Animal Science and Technology
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• 제66권1호
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• pp.156-166
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• 2024

Pigs are genetically, anatomically, and physiologically similar to humans. Recently, pigs are in the spotlight as a suitable source animal for xenotransplantation. However, to use pigs as source animals, pigs should be raised in designated pathogen-free facilities. There is abundant data from embryo transfer (ET) experiments using farm pigs as surrogates, but data on ET experiments using minipigs are scarce. Eighty minipigs were used for ET experiments and after transplantation, the implantation and delivery rates were investigated. It was also confirmed whether the pregnancy rate could be increased by changing the condition or surgical method of the surrogate. In the case of minipigs that gave birth, the size of the fetal sac on the 28th day of ET was also measured. The factors that can affect the pregnancy rate such as estrus synchronization program, ovulation status at the time of ET, the number of repeated ET surgeries, and the ET sites, were changed, and the differences on the pregnancy rate were observed. However there were no significant differences in pregnancy rate in minipigs. The diameter of the implanted fetal sac on the 28th day after ET in the minipigs whose delivery was confirmed was calculated to be 4.7 ± 0.5 cm. In conclusion, there were no significant differences in pregnancy rate of minipigs in the comparative experiment on various factors affecting the pregnancy rate. However, additional experiments and analyses are needed due to the large individual differences of the minipigs.

• Asian-Australasian Journal of Animal Sciences
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• 제22권1호
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• pp.20-25
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• 2009

Xenotransplantation of pig organs into humans is a potential solution for the shortage of donor organs for transplantation. However, multiple immune barriers preclude its clinical application. In particular, the initial type of rejection in xenotransplantation is an acute cellular rejection by host $CD8^+$ cytotoxic T lymphocyte (CTL) cells that react to donor major histocompatibility complex (MHC) class I. The human cytomegalovirus (HCMV) glycoprotein Unique Short (US) 2 specifically targets MHC class I heavy chains to relocate them from the endoplasmic reticulum (ER) membrane to the cytosol, where they are degraded by the proteasome. In this study we transfected the US2 gene into minipig fetal fibroblasts and established four US2 clonal cell lines. The integration of US2 into transgenic fetal cells was confirmed using PCR and Southern blot assay. The reduction of Swine Leukocyte Antigen (SLA)-I by US2 was also detected using Flow cytometry assay (FACS). The FACS analysis of the US2 clonal cell lines demonstrated a substantial reduction in SLA-I surface expression. The level (44% to 76%) of SLA-I expression in US2 clonal cell lines was decreased relative to the control. In cytotoxicity assay the rate of $CD8^+$ T cell-mediated cytotoxicity was significantly reduced to 23.8${\pm}$15.1% compared to the control (59.8${\pm}$8.4%, p<0.05). In conclusion, US2 can directly protect against $CD8^+$-mediated cell lysis. These results indicate that the expression of US2 in pig cells may provide a new approach to overcome the CTL-mediated immune rejection in xenotransplantation.

• 생명과학회지
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• 제19권3호
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• pp.417-421
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• 2009

4, 8, 12, 20 주령의 미성숙 미니돼지에서 방사선과 초음파를 이용하여 복부 주요 장기의 형태학적 특징을 살펴보았다. 방사선 검사는 전반적인 장기의 형태를 확인하는 데 이용되는 가장 기본적이고 단순한 방법이다. 기본 복부방사선 사진에서 이용되는 평가해야 할 항목들은 우선 전반적인 복부세부음영의 정도, 간, 위, 비장, 신장, 방광, 장들의 위치, 크기, 형태, 변연, 후복강 평가이다. 초음파 검사는 이러한 주요 장기들의 내부 실질을 평가하는 데 주로 사용된다. 미니돼지는 개와 고양이와 비교했을 때 유사한 소견을 가진 것을 확인하였다.