• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.166-171
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• 2015

A palato-radicular groove (PRG) is a developmental anomaly primarily found in the maxillary lateral incisors. It is a potential communication path between the root canal and the periodontium that decreases the survival prognosis of the affected tooth, therefore compromising the stability of the dental structure in the oral cavity. The aim of this case report is to present an original technique where a PRG was treated by means of intracanal disinfection, PRG sealing with glass ionomer, replantation with intentional horizontal 180 degree rotation of the tooth, and an aesthetic veneer placed to provide adequate tooth morphology. The clinical and biological benefits of this novel technique are presented and discussed.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.57-62
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• 2019

Eutima japonica Uchida, 1925, a bivalve-inhabiting hydrozoan was collected for the first time in Korea, associating with Mytilus galloprovincialis. The morphology of male medusae of this hydrozoan is clarified by culture and described as well as other developmental stages. As the present material from Korea is in good accord with that of the northern Japanese form of E. japonica, so the geographical distribution of the northern form of this species is widened, Japan, China and Korea. Green fluorescent protein distribution pattern of this medusa is also described and compared with that of the most related species Eutima sapinhoa Narchi and Hebling, 1975.

• Biomedical Science Letters
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• v.28 no.4
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• pp.290-297
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• 2022

Through previous studies, the central nervous system (CNS) was collected by dividing the scuttle fly into larval, pupa, and adult stages by developmental stage, and the morphological characteristics were observed. In situ hybridization (ISH) using the collected central nervous system, it was possible to confirm the location and extent of expression of the neurotransmitter corazonin (Crz) at each stage of development. In this study, paraffin specimens were prepared using central nervous system tissues of 3rd instar larval stage of scuttle fly, which had completed in situ hybridization, and general histochemical staining (hematoxylin-eosin, H-E) and special histochemical staining (luxol fast blue-cresyl violet) was performed to observe the histological and cytological morphology characteristics of corazonin neurons. As a result, a variety of nerve cell body existed between many myelin sheath. The corazonin neurons compose cortex of central nervous system with other neurons congregating in this tissue and show larger cell body relatively in neurohistochemical analysis.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.547-554
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• 1993

This study was carried out to investigate the best condition for in vitro and in vivo culture after freezing and thawing of nuclear transplant 2 cell embryos. When nuclear transplant embryos were submitted to electrofusion, the significantly higher fusion rates of 2 cell donor nuclei were achieved at the electric field strength of DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The significantly higher fusion rates of 4 cell donor nuclei were achievecl at DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The fusion rates in 8 cell donor nuclei were 94.2~99.3%. The developmental potency to blastocyst in 2 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $150{\mu}sec$ treated group(p<0.01). The significantly higher developmental potency to blastocyst in 4 cell donor nuclei were achieved at the electric field strength of DC 2.0 kV/cm for $150{\mu}sec$ than DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The develop mental potency to blastocyst in 8 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2 cell donor nuclei than in 8 cell donor nuclei(p<0.01). When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant(p<0.01). The production rates of offspring after transfer of nuclear transplant embryos to recipient mouse were no significant difference in 2, 4 and 8 cell donor nuclei.

• Reproductive and Developmental Biology
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• v.30 no.1
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• pp.35-40
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• 2006

This study was performed to investigate the effects of embryo developmental stage and superoxide dismutase (SOD) on the survival of frozen-thawed porcine embryos by open pulled straw(OPS) method. Porcine IVF blastocysts were frozen-thawed by OPS method and cultured for 48 h under the existence of SOD. There are no significant differences in the proportions of normal morphology among the early, mid- and expanded blastoryst stages $(30.8{\sim}38.6%)$. After culture of embryos, the developmental rates to the expanded blastocyst stage(38.7%) were significantly higher than those of other stages (P<0.05). The proportions of expanded and hatched embryos were higher in medium with 1 unit/ml SOD than 0 and 10 units/ml of SOD. The result indicates that OPS method can use for the pig embryo cryopreservation, especially for the late stage blastocysts. SOD may can reduce the demage of frozen-thawed porcine embryos.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.339-346
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• 2006

In this study we conducted artificial hybridization between two sibling species, Rhodeus uyekii and R. notatus, and observed the morphological characteristics in early developmental stage. The two species showed difference in egg shape having rhombus and club respectively. The morphology of yolk of larva just hatched also showed well specific characteristics, that is the bean chaff type for R. uyekii (U type) and anchor type for R. notatus (N type). The rate of fertilization between female R. uyekii and male R. notatus (UN type) and between female R. notatus and male R. uyekii (NU type) were complete and its hatching rate were very high, 71.6% for UN type and 97.5% for NU type. The differences occurred in the yolk shape of hatched larvae for each combination of hybrids. In the group of UN, U type of larvae were found very rarely, but almost all the larvae showed intermediate shape polarized to NN type. Similar phenomenon was observed in the NU having intermediate polarized to UU, but without any NN type. These hybrids will be analyzed for their external morphology, sex ratio, the function of sexual organ and karyology after they grown up to adult.

• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.375-383
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• 2000

The nuclear maturation and developmental competence of immature, oocytes collected from donors at various morphology of corpus luteum (CL) and fertilized in vitro was investigated by comparing the meiotic activity and the yields of embryos. Ovaries were divided and classified into 4 groups as the following criteria : Group 1 ; ovaries showed evidence of recent ovulation (corpus hemorragicum). Group 2 ; apex of CL was red or brown. Vasculization was limited to periphery of CL. Group 3 ; apex of CL was orange or tan. Vasculization was covered over apex of CL. Group 4 ; CL was light yellow to white and firm in texture and the vascular network on the surface of CL had disappeared. Modified TCM 199 was used for maturation in vitro of immature oocytes and development was induced by using TLP-PVA as a basic medium. When oocytes collected from each group of donors had been matured for 4, 14, and 24 hours in vitro, the proportion of oocytes reaching metaphase I and metaphase II were not different among oocytes from 4 group of ovaries. Mature metaphase II stage of oocytes in each group was first observed at 14 hours, whereas completion of maturation of. oocytes in each group was at 24 hours. Luteal morphology of ovaries had little effect on the proportion of embryos reached 2 cells and 8 cell stage. However, the proportion of embryos cleaved to morula and blastocyst stage was significantly higher in the oocytes obtained from group 1 and 3 than in the oocytes from group 2 and 4 (p＜0.05). This data suggest that reproductive status of the donor significantly influence the yield of in vitro embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.25-32
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• 2010

The present study aimed to examine the effects of ${\gamma}$-linolenic acid (GLA) supplementation to in vitro culture (IVC) medium on in vitro developmental competence, freezability and morphology of in vitro matured and fertilized bovine embryos. In vitro produced (IVP) bovine zygotes were cultured in IVC medium supplemented with 0 (negative control), 15, 31, 62, 125, 250, 500 or 1,000 ppm GLA, 250 ppm linoleic acid albumin (LAA) and without any supplement as a control. Day 6 blastocysts derived from culture control were cultured in IVC medium containing either 62, 250 GLA or 250 LAA for 24 h, and at Day 7 were subjected to freezing or morphological examination by electron microscope. GLA 15 showed a tendency to have a higher cleavage rate at Day 2 (70.3%) than other groups. The hatching rate at Day 9 in LAA (38.2%) was significantly higher than the control and all treatment groups (p<0.05), while the blastocyst rate in LAA (32.4%) did not differ from those of 15 (30.5%), 31 (27.1%), and 62 GLA (33.1%) or the control (35.1%). GLA in concentrations of 125, 250, 500, and 1,000 ppm had significantly detrimental effect on the blastocyst rate compared to 15, 31 and 62 ppm GLA, LAA, and control groups (p<0.05). In contrast, the highest post-thaw survival rate (100%) was observed in the control group (p<0.01). Large lipid droplets were observed in the cytoplasm of trophoblastic cells, even in the control, but were abundant in GLA groups. Taking the results of the study into consideration, the addition of GLA to the culture medium for IVP bovine embryos at the dose of 15 ppm increased the developmental competence of zygotes and enhanced the cleavage rate up to Day 2. However, blastulation rate and post-thaw survival were not increased when GLA was added to the culture media.

• Development and Reproduction
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• v.16 no.4
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• pp.353-361
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• 2012

Human embryonic stem (ES) cells are a potential source of cells for developmental studies and for a variety of applications in transplantation therapies and drug discovery. However, human ES cells are difficult to culture and maintain at a large scale, which is one of the most serious obstacles in human ES cell research. Culture of human ES cells on MEF cells after disassociation with accutase has previously been demonstrated by other research groups. Here, we confirmed that human ES cells (H9) can maintain stem cell properties when the cells are passaged as single cells under a feeder-free culture condition. Accutase-dissociated human ES cells showed normal karyotype, stem cell marker expression, and morphology. We prepared frozen stocks during the culture period, thawed two of the human ES cell stocks, and analyzed the cells after culture with the same method. Although the cells revealed normal expression of stem cell marker genes, they had abnormal karyotypes. Therefore, we suggest that accutase-dissociated single cells can be usefully expanded in a feeder-free condition but chromosomal modification should be considered in the culture after freeze-thawing.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.1
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• pp.31-39
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• 2008

After the introduction of ultrasound enabling a detailed view of both neonatal hip instability and morphology, two different streams have developed: one arguing that neonatal hip instability is the major pathology warranting treatment, the other including acetabular dysplasia as an important feature. Graf's method including the acetabular dysplasia led to higher treatment and follow-up rate than that based upon neonatal hip instability only. Recent report suggested that improved examination techniques and a better understanding of the findings have enabled a more tailored approach, and no differences in treatment rates exist due to different ultrasound techniques. I'd like to emphasize that enough experiences and the understanding enabling standardized examination and high repeatbility is more important than the choice of different techniques. Here the mothods and meanings of different techniques of ultrasound and its usefulness in the diagnosis and treatment of DDH is discussed.