• Journal of Embryo Transfer
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• v.32 no.4
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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 Embryo Transfer
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• v.33 no.4
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• pp.337-342
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• 2018

Cryopreservation is mainly used for preservation of boar sperm. However, this method stresses the sperm by reactive oxygen species (ROS), and the conception rate and the litter size are not more efficient than the liquid preservation of spermatozoa. Therefore, we use chitosan which is a natural product derived antioxidant compound. We used GnHA (chitosan+hyaluronic acid) and GnHG (chitosan hydrogel) as chitosan complexes to cryopreserve boar sperm for improve sperm metabolism and function. Sperm parameter (sperm motility, progressive motility, path velocity, straight-line velocity, curvilinear velocity) is measured by computer-assisted sperm analysis (CASA) using frozen sperm with GnHA or GnHG (0, 0.25, 0.5, 1 mg/mL), respectively. Also, lipid peroxidation analysis using malondialdehyde (MDA) is performed to confirm the antioxidative effect of chitosan in frozen spermatozoa. CASA analysis showed GnHA and GnHG are effective against cryopreserved boar sperm. And antioxidant effect is measured by lipid peroxidation analysis. GnHA and GnHG, which is chitosan complex are effective for boar sperm cryopreservation by antioxidant effect.

• Journal of Life Science
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• v.16 no.6
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• pp.1060-1065
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• 2006

Non-invasive evaluation of liver function in animal models remains a challenge. Hepatoscintigraphy provides information about changes in liver size and shape, and enables to understand general liver function. Futhermore it is readily used to diagnosis complications of liver transplantation like hepatitis, rejections and biliary complications. In this study, we investigated the usefulness of evaluating the liver function in miniature pigs with $^{99m}Tc-Tin$ colloid and $^{99m}Tc-DISIDA$ which are the most commonly used radiopharmaceuticals in human medicine. In result, $^{99m}Tc-Tin$ colloid was uptaked in lung, liver, gastric wall and kidney in miniature pigs. And $^{99m}Tc-DISIDA$ showed continuous uptake images of heart, lung, liver, gallbladder and duodenum, and it was similar to human's. Therefore we could conclude $^{99m}Tc-Tin$ colloid would not be suitable for evaluating hepatic function because of it's nonspecific affinity, however $^{99m}Tc-DISIDA$ scintigraphy would be an effective method for detecting hepatobiliary function in miniature pigs.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.585-592
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• 2004

Our previous studies demonstrated that relaxin in concert with estrogen promotes development of the mammary parenchyma during the last third of gestation in gilts, and the specific relaxin-binding sites were present in the mammary gland. This study was conducted to determine if relaxin-binding sites in the mammary gland were functional relaxin receptors. Three cycling cross-bred gilts were bilaterally ovariectomized on day 0 of the experiment. Beginning on day 15 and continuing through day 29 post-surgery, the gilt received an im. injection of estradiol benzoate at 12-hr intervals. Beginning on day 22 post-surgery, highly purified porcine relaxin was administered(lug/hr) into the left fourth mammary gland from the anterior end via miniature osmotic pump. Physiological saline was administered to the right fourth mammary gland. The gilt was sacrificed on day 29 post-surgery and histological characteristics of the mammary parenchyma were examined. The mammary glands treated locally with saline showed little, if any, lobulo-alveolar development, whereas the mammary glands treated with relaxin showed not only marked lobulo-alveolar development but also prominent secretions in the alveoli. The saline-treated glands were characterized by relatively dense and highly organized collagen fiber bundles. Whereas, in the relaxin-treated mammary glands, collagen fiber bundles were dispersed and loosely organized. In conclusion, relaxin-binding sites in the mammary gland are functional relaxin receptors and relaxin acts directly on the pig mammary gland to promote development of the alveoli and remodeling of the extracellular matrix.

• Journal of Life Science
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• v.27 no.7
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• pp.739-745
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• 2017

In all mammalian species, progesterone is essential in the preparation for and maintenance of pregnancy. $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone ($20{\alpha}$-OHP), and plays a crucial role in the termination of pregnancy and initiation of parturition. In this study, we characterized the expression and localization of $20{\alpha}$-HSDinthe testis of MediKinetics $Micropigs^{(R)}$. The testes were collected at days 6, 9, 12, 18, and 21 after birth. The $20{\alpha}$-HSD mRNA was found to be expressed in the testis at day 6 after birth by RT-PCR. The highest level of mRNA expression in the testis was detected on day 21 after birth. However, the mRNA was not detected in the placenta after parturition. Western blot for $20{\alpha}$-HSD reveal that the specific 37-kDa band was detected in immature pig testis. However, this band was not detected in testis tissue at day 6 after birth. In the immunohistochemical analysis of the testis, $20{\alpha}$-HSD was detected in the Sertoli cells and Leydig cells. Taken together, our study shows for the first time that the $20{\alpha}$-HSD mRNA and protein are expressed in pig testis after birth. Further investigation is required to elucidate the functional mechanisms of $20{\alpha}$-HSD in pig testis after birth.

• Animal Bioscience
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• v.34 no.11
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• pp.1749-1756
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• 2021

Objective: Microminipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs. Methods: The occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters. Results: The incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different. Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

• Reproductive and Developmental Biology
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• v.36 no.4
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• pp.249-254
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• 2012

This study aimed at investigating whether a porcine follicular fluid (pFF) supplementation positively affects the characteristics of donor cells and the developmental competence of porcine cloned embryos. Ear fibroblast cells (donor cell) from an Massachusetts General Hospital miniature pig were cultured in different culture methods: (1) Dulbecco's modified Eagle's medium (DMEM)+10% FBS (Control); (2) DMEM+0.5% FBS (SS); and (3) DMEM+10% FBS+10% pFF (pFF) for 72 h. In each conditioned medium, the concentrations of 4 amino acids (Thr, Glu, Pro, and Val) in the pFF group were significantly different from those in the control group (p<0.05 or p<0.01). The proliferation of the cells cultured in the SS group was significantly lower than that of the other treatment groups (p<0.01). The population of apoptotic and necrotic cells in the SS group was significantly higher than that of either the control or the pFF group (p<0.01). The number of embryos that cleaved (p<0.05) and developed into blastocysts (p<0.01) in the SS group was significantly lower than that of either the control or the pFF group. Compared to other groups, the blastocysts produced from the donor cells in the pFF group had higher total cells and lower apoptotic cells (p<0.05). It can be concluded that pFF supplementation in the donor cell culture medium positively affects cell death, cell cycle and quality of the cloned blastocyst.

• Journal of Life Science
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• v.19 no.3
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• pp.417-421
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• 2009

This report describes the normal radiographic and ultrasonographic morphological features of premature minipigs at 4, 8, 12 and 20 weeks of age. Radiographic examination is a simple diagnostic method used to identify the general morphologic state of major organs and their adjacent structures, and to assess the presence of abnormalities. The parameters for evaluation in plain abdominal radiographs are the degree of diffuse serosal margin details, extent of visualization of each organ, their size, shape, and contour, locations of main organs - such as the liver, stomach, spleen, kidneys, urinary bladder - the distribution of the intestines, and assessment of the retroperitoneal space and its contents. Ultrasonographic examinations are used to investigate their internal condition. The parameters for evaluation in abdominal ultrasonography are echogenicity, echotexture, and size and shape of the main organs such as the liver, spleen, kidney, urinary bladder and gastrointestinal tract. Minipigs had similar findings compared to dogs or cats.

• Journal of Embryo Transfer
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• v.28 no.3
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• pp.265-271
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• 2013

Cryopreservation and in vitro fertilization (IVF) protocols are important in genetic studies and applications to transgenic animals. Various studies about boar sperm cryopreservation have been studied for a long time. Those were about the use of extenders, the choice of sugars, the cooling and warming rates. The factors that influence the boar sperm are the dramatic changes in temperatures, osmotic and toxic stresses, and reactive oxygen species (ROS) generation. Among these factors, ROS generation is the main damage to DNA which is a principal genetic material and the most important for the practical applications. So we wondered whether ROS generation could be reduced. In previous study, monothioglycerol (MTG) was essential for the culture of embryo stem cells. Therefore we added MTG in the freezing extender based on lactose-egg yolk (LEY) with trehalose. For the assessment of the frozen-thawed sperm, we focused onmotility, membrane integrity and DNA damage. First, we used a computer-aided sperm analysis system for overall conditions of sperm such as motility and viability. Then we performed the sperm chromatin structure assay for DNA integrity and hypo-osmotic swelling test for membrane integrity. And our result showed the existence of MTG in the freezing extender caused less damage to DNA and higher motility in frozen-thawed boar sperm. Also we checked a relative antioxidant activity of MTG in modified Modena B extender. We concluded that this reagent can activate sperm mitochondria at MTG $0.2{\mu}M$, contribute to sperm motility and DNA integrity but there was no significant difference on membrane integrity. Also antioxidant activity of MTG in modified Modena B extender was proved.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.3
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• pp.120-126
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• 2013

Objectives: This study sought to elucidate the effect of autogenous tooth bone material by experimenting on minipig's maxillary sinus and performing histological and histomorphometric analyses. Materials and Methods: Five 18-24 month-old male minipigs were selected, and right maxillary sinuses were grafted with bone graft material made of their respective autogenous teeth extracted eight weeks earlier. The left sides were grafted with synthetic hydroxyapatite as control groups. All minipigs were sacrificed at 12 weeks after bone graft, which was known to be 1 sigma (${\sigma}$) period for pigs. Specimens were evaluated histologically under a light microscope after haematoxylin-eosin staining followed by semi-quantitative study via histomorphometric analysis. The ratio of new bone to total area was evaluated using digital software for calculation of area. Results: All specimens were available, except one on the right side (experimental group), which was missing during specimen preparation. This study demonstrated new bone at the periphery of the existing bone in both groups, showing evidence of bone remodeling, however, encroachment of new bone on the central part of the graft at the 1 ${\sigma}$ period was observed only in the autogenous tooth bone group (experimental group). Histomorphometric analysis showed more new bone formation in the experimental group compared to the control group. Although the difference was not statistically significant (P>0.05), the mean percentage area for new bone for the experimental and control groups were $57.19%{\pm}11.16%$ and $34.07%{\pm}13.09%$, respectively. Conclusion: The novel bone graft material using autogenous tooth is a good alternative to autogenous bone, comparable to autogenous bone, and outperforming synthetic hydroxyapatite bone graft materials in terms of bone regeneration capacity. Augmentation with autogenous tooth bone materials will reduce donor site morbidity without hampering the safety of the autogenous bone graft.