• The korean journal of orthodontics
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• v.14 no.1
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• pp.65-81
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• 1984

In order to observe the responses of the periodontal tissue on the tension side following the experimental tooth movement, 35 Guinea pigs were divided into the control group (5 animals) and 6 experimental groups (3 movement groups and 3 retention groups) consisting of each 5 animals. The experimental tooth movement of Guinea pig's upper incisors installing open helical loop were carried out by rendering continuous force : 5g (1st groups) 35g (2nd groups), 100g (3rd groups), respectively for 7 days. 3 movement groups (15 animals) were sacrificed soon after the continuous force, and 3 retention groups (15 animals) were sacrificed after the retention period of another 7 days. The following results were obtained from the observation of the surrounding tissues of teeth on the tension side through light microscopy any transmission electron microscopy. 1. The vessel walls in the experimental groups were thinner than those of the control group, the number of blood vessel had the tendency to increase. The greater the strong force applied to each group, the more the destruction of cells and fibers was found and the more the number of the red blood cell of vessel outside appeared. 2. New collagen fibers were produced from fibroblasts in the 1st groups (light force), but were produced rather less in the 2nd groups (medium force) and the 3rd groups (heavy force). 3. In the forming patterns of the new alveolar bone of the 3rd groups (heavy force), the bone trabeculae were formed towards the direction of the force to be applied, but the new alveolar bone in the 1st groups (light force) was produced evenly throughout the all surfaces of the alveolar bone rather than the patterns of bone trabeculae ; therefore, the patterns of new alveolar bone were observed differently according to the magnitude of the force applied. 4. In the retention group, it was observed that the collagen fibers were produced from the osteoblasts in the marginal areas of the periodontal ligaments being widely opened and were deposited on the alveolar bone surface but the production of collagen fibers from the osteoblasts in the other area of the periodontal ligaments was almost ceased, and a rest line on the new alveolar bone surface was found.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.124-124
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• 2003

The successful development of embryos cloned by nuclear transfer (NT)have been dependent on a wide range of known factors including cell cycle of donor and recipient ooplast, oocyte quality, NT procedure and oocyte activation. The present study compared the development of cloned porcine embryos following different activation treatments. Cumulus-oocyte complexes (COCs) were aspirated from 26 mm follicles of slaughterhouse ovaries and cultured for 22 h in NCSU #23 medium supplemented with 10% porcine follicular fluid, 0.57 mM cysteine, 0.5 g/mL LH, 0.5 g/mL FSH and 10 ng/mL EGF. The COCs were further cultured for an additional 22 h in the same medium at $39{\cird}C$ in an atmosphere of 5% $CO_2$ in air, without hormonal supplements. Primary cultures of fibroblasts isolated from a female fetus on day 40 of gestation were established in DMEM + 15% FCS. For nuclear donation, cells at the 5th-6th passage were cultured in DMEM +0.5% FCS for 5 days in order to arrest the cells in G0/Gl. After enucleation, oocytes were reconstructed by transfer of donor cells and fusion with three DC pulses (1.4 KV/cm, 30 sec) in 0.28 M mannitol containing 0.01 mM $CaCl_2$ and 0.01 mM $MgCl_2$. Eggs were then divided into three treatment groups, control (without further treatment, Group 1), eggs cultured in 10 g/ml cycloheximide (CHX) for 5 h (Group 2), and eggs cultured in 1.9 mM 6-dimethylaminopurine (6-DMAP) for 5 h (Group 3). The eggs were then cultured in sets of 30 in 60 I drops of NCSU#23 supplemented with 4mg/ml BSA (essentially fatty acid free) until day 7 at $39{\circ}C$ in a humidified atmosphere of 5% $CO_2$. On day 4 the culture were fed by adding 20 I NCSU #23 supplemented with 10% FBS. Development rates into blastocysts were significantly higher (P<0.05) in Group 3 embryos compared to Group 1 controls ($27.6 \mu 2.7% vs. 20.1 \mu 4.1%$, respectively), but rates did not differ in Group 2 compared to control ($23.8 \mu 5.7%$). Total cell number in Group 3 blastocysts was however significantly higher (P<0.05) than in Groups 1 and 2 ($44.6 \mu 2.4 vs. 19.9 \mu 1.9 and 21.9 \mu 2.1$, respectively). These results suggest that 6-DMAP is more efficient than cycloheximide in the activation of electrically fused NT oocytes during in vitro production of cloned porcine embryos.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.40.1-40.13
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• 2022

Background: Somatic cell nuclear transfer (SCNT) is used widely in cloning, stem cell research, and regenerative medicine. The type of donor cells is a key factor affecting the SCNT efficiency. Objectives: This study examined whether urine-derived somatic cells could be used as donors for SCNT in pigs. Methods: The viability of cells isolated from urine was assessed using trypan blue and propidium iodide staining. The H3K9me3/H3K27me3 level of the cells was analyzed by immunofluorescence. The in vitro developmental ability of SCNT embryos was evaluated by the blastocyst rate and the expression levels of the core pluripotency factor. Blastocyst cell apoptosis was examined using a terminal deoxynucleotidyl transferase dUTP nick end-labeling assay. The in vivo developmental ability of SCNT embryos was evaluated after embryo transfer. Results: Most sow urine-derived cells were viable and could be cultured and propagated easily. On the other hand, most of the somatic cells isolated from the boar urine exhibited poor cellular activity. The in vitro development efficiency between the embryos produced by SCNT using porcine embryonic fibroblasts (PEFs) and urine-derived cells were similar. Moreover, The H3K9me3 in SCNT embryos produced from sow urine-derived cells and PEFs at the four-cell stage showed similar intensity. The levels of Oct4, Nanog, and Sox2 expression in blastocysts were similar in the two groups. Furthermore, there is a similar apoptotic level of cloned embryos produced by the two types of cells. Finally, the full-term development ability of the cloned embryos was evaluated, and the cloned fetuses from the urine-derived cells showed absorption. Conclusions: Sow urine-derived cells could be used to produce SCNT embryos.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.201-208
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• 2004

This study was performed to examine the effects of catalase and $\beta$-mercaptoethanol ($\beta$ME) on the establishment of clonal lines from porcine fetal fibroblast cells. Fibroblasts derived from a pig fetus (Day 50) were passaged two times before use. A single cell was seeded in 96-well plates and cultured in medium supplemented with or without catalase or $\beta$ ME. Cell colonies were passaged two times into 4-well dish. Cell lines with proliferating potential were classified as an established clonal cell line. In experience 1, the establishment efficiencies were examined by addition of catalase (100ng/$m\ell$) or $\beta$ME (100 uM) in culture medium. The establishment efficiency of $\beta$ME-added group (8.3％) was significantly higher than that of control group (3.2％, P<0.05). However, catalase did not have a positive efffct on the establishment efficiency. In experience 2, the establishment efficiencies were examined by addition of different concentrations of catalase (0-1,000 ng/$m\ell$) in culture medium. However, establishment efficiencies were not different among the different concentrations of catalase (0-2.6％). In experience 3. the establishment efficiencies were examined by addition of different concentrations of $\beta$ME(0-1,000 uM) in culture medium. The establishment efficiency was significantly higher in 100 uM $\beta$ME-added group (9.4％) compare to others (0-1.6％). The result of present study shows that the establishment efficiency of clonal cell lines can be enhanced by the culture in media supplemented with 100uM $\beta$ME. However, catalase did not have a positive effect on the establishment efficiency.