• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1031-1040
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• 2015

Ultrstructural studies of germ cell differentiation and vitellogenesis in the oocytes of the female Rapana venosa in the brackish water area of Seomjin River were investigated by transmission electron microscope observations. In the early vitellogenic oocytes, the Golgi complex and mitochondria were involved in the formation of glycogen particle, lipid droplets, and yolk granules. In the late vitellogenic oocytes, the rough endoplasmic reticulum and multivesicular bodies were involved in the formation of proteid yolk granules in the cytoplasm. However, heterosynthetic vitellogenesis in this species were not observed in vitellogenic oocytes during oogenesis. A mature yolk granule was composed of three components: crystalline core, electron lucent cortex and the limiting membrane. As shown in some large gastropods, vitellogenesis in R. venosa occurred by way of endogenous autosynthesis without heterosythetic vitellogenesis (exogeneous endocytosis), which are found in the oocytes in bivalves. The mating period and spawning activity were related with the increases of seawater temperatures and salinities.

• Journal of agricultural medicine and community health
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• v.16 no.2
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• pp.154-164
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• 1991

Albendazole is a broad spectrum anthelmintics with high activity against intestinal nematodes as well as tremtodes and cestodes infections. But so far wormicidal effect of albendazole against Paragonimus westermani is uncertain. The present study undertaken to observe the morphological changes of Paragonimus westermani which was obtained from experimentally infected with metacercariae isolated from Cambaroides similis and 9 of them were given albendazole 2 doses of 25mg/kg daily for the 2 days and 4 days from the day of 20 weeks after infection. The Paragonimus werms were collected from the lung of the cats which were autopsied at 24 hours after treatment. The fine structures of the collected worms were studied by means of scanning and transmission electron microscopy. The findings of the observations were compared with those of untreated worms. The results are as follows : 1) In the scanning electron microscopic(SEM) observations, the worms obtained from 2 days treated group showed many blebs which were formed on the surface of damaged tegument in between two suckers. Protrusion of oral sucker typically observed and surrounding tegumental ridges were damaged. 2) The worms obtained from 4 days treated group showed marked contraction revealing half size of normal worms. 3) The transmission electronmicroscopic(TEM) observations indicated that large blebs of irregular shapes were formed by the destruction of tegumental ridge of tegumental syncytium and also showed degeneration of mitochondriae. 4) Destruction of tegumental syncytium formation of blebs were usually observed in the ventral side of the worms. 5) Differentiation of tegumental layer and basement layer muscular layer and parenchymal layer around two suckers of worms obtained at 4 days treated group was difficult. 6) Many host cells invaded and destroyed the degenerated tegument by the occurrence of blebs or the exposed muscular layer of the worm after exfoliation of the tegument.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.271-281
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• 2004

Adenoid cystic carcinoma is malignant tumor in salivary gland, and its behavior is very invasive. Of all malignant tumor adenoid cystic carcinoma is occured in frequency of 4.4% in major salivary gland, and 1.29% in minor salivary gland. Histopathologically, adenoid cystic carcinoma is characterized by a cribriform appearance, and tubular form and solid nest type tumor can be seen. The tumor cell structure composed of modified myoepithelial cell, and basaloid cell. Extracellular matrix of this tumor cell contains variable ground substance with basement membrane component. Basement membrane matrix composed of collagen fibers, glycoproteins, proteoglycans, and its function is well known that it participate in differentiation, proliferation, and growth of tumor cell. Basement membrane molecule is essential for invasion of peripheral nerve, blood vessel, skeletal muscle in tumor cell of adenoid cystic carcinoma. In many studies, the tumor cell of adenoid cystic carcinoma containing modified myoepithelial cell participate in synthesis of proteoglycan. In this study, tissue sample of adenoid cystic carcinoma of human salivary gland were obtained from 15 surgical specimen, and all specimen were routinely fixed in 10% formalin and embedded. Serial $4-{\mu}m$ thick sections were cut from paraffin blocks. the histopathologic evaluation was done with light microscopy. And, the immunohistochemical staining, characteristics of glycosaminoglycan were observed. For biochemical analysis of glycosaminoglycan, isolation of crude glycosaminoglycan from tumor tissue and Western bolt analysis were carried out. With transmission electomicroscopy, tumor cell were observed. Biologic behavior of adenoid cystic carcinoma was observed with distribution and expression of basement membrane of glycosaminoglycan in tumor cells, The results obtained were as follows: 1. In immunohistochemical study, chondroitin sulfate is postively stained in tumor cell and interstitial space, dermatan sulfate is weakly stained in ductal cell. But keratan sulfate is negatively stained. 2. In immunohistochemical study, heparan sulfate is strong positive stained in tumor cell and basement membrane, especially in invasion area to peripheral nerve tissue. 3. In transmission electromicroscpic view, the tumor cells are composed modifed myoepithelial cells, and contains many microvilli and rough endoplasmic reticulum. 4. In Western blot analysis, the expression of glycosaminoglycan is expressed mostly in heparan sulfate. From the results obtained in this study, tumor cell of adenoid cystic carcinoma is composed modified myoepithelial cell, and glycosaminoglycan of basement membrane molecule of heparan sulfate and chondroitin sulfate mostly participate in the development and invasiveness of adenoid cystic carcinoma by immunohistochemical study and western blot analysis.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.55-65
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• 2011

Some characteristics of germ cell differntiations during spermiogenesis and mature sperm ultrastructure in male Phacosoma japonicus were investigated by transmission electron microscope observations. The morphology of the spermatozoon of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. The spermatozoon is approximately 45-50 ${\mu}m$ in length, including a long curved sperm nucleus (about $3.70{\mu}m$ long with 45 $^{\circ}$ of the angle of the nucleus, an acrosome (about $0.55{\mu}m$ in length), and tail flagellum (about 42-$47{\mu}m$)The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the sperm midpiece of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• Restorative Dentistry and Endodontics
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• v.37 no.1
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• pp.34-40
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• 2012

Objectives: The aim was to confirm the stem cell-like properties of the dental pulp stromal cells and to evaluate the morphologic changes during in vitro chondrogenesis. Materials and Methods: Stromal cells were outgrown from the dental pulp tissue of the premolars. Surface markers were investigated and cell proliferation rate was compared to other mesenchymal stem cells. Multipotency of the pulp cells was confirmed by inducing osteogenesis, adipogenesis and chondrogenesis. The morphologic changes in the chondrogenic pellet during the 21 day of induction were evaluated under light microscope and transmission electron microscope. TUNEL assay was used to evaluate apoptosis within the chondrogenic pellets. Results: Pulp cells were CD90, 105 positive and CD31, 34 negative. They showed similar proliferation rate to other stem cells. Pulp cells differentiated to osteogenic, adipogenic and chondrogenic tissues. During chondrogenesis, 3-dimensional pellet was created with multi-layers, hypertrophic chondrocyte-like cells and cartilage-like extracellular matrix. However, cell morphology became irregular and apoptotic cells were increased after 7 day of chondrogenic induction. Conclusions: Pulp cells indicated mesenchymal stem cell-like characteristics. During the in vitro chondrogenesis, cellular activity was superior during the earlier phase (within 7 day) of differentiation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.87-109
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium­deficient diet on the dentin and cementum formation of rat molar. The pregnant three-week old Sprague­Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group and irradiation/calcium-deficient diet group. The control group was non­irradiation/normal diet group. The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin antibody. The results were as follows; 1. The Hertwig's epithelial root sheath cells, which are related to the differentiation of the tooth-forming cells, showed irregular cellular arrangement, decrease of intercellular junctional complex, and decreased immunoreactivity to the fibronectin after irradiation. These were more severe in the irradiation/calcium-deficient diet group. 2. The cementoblasts at the cementum-forming area showed chromatin clumpings after irradiation. The immu noreactivity to the fibronectin was weaken after irradiation, especially irradiation/calcium-deficient diet group. 3. The odontoblasts at the dentin-forming area showed increase of lysosomes in the cytoplasm and destruction of intercellular junctional complex. The irradiation/calcium-deficient diet group showed decrease of number and density of the electron dense particles and a large number of vacuoles scattered in the dentin matrix. The immunoreactivity was weaken.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.3
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• pp.247-255
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• 2007

The bone morphogenic protein(BMP) can promote migration and growth of mesenchymal cells and initiate process for bone and cartilage formation. Cartilage-derived morphogenic protein(CDMP)-1 and -2 belong to the bone morphogenetic protein family in the transforming growth factor(TGF)-${\beta}$ superfamily. Although pleomorphic adenoma of the salivary glands is an epithelial tumor, it frequently shows ectopic cartilaginous formation with biomolecular studies. The mechanism of pathogenesis in cartilaginous formation is still controversy. We examined the expression and localization of CDMP-1 and -2, in comparison with the localization of cartilaginous matrix proteins, in human normal salivary glands and 20 cases of pleomorphic adenoma using immunohistochemical methods. The results were followed. 1. CMP-1 was immunolocalized in the striated ducts and the intercalated ducts, but not expressed in excretory duct, CDMP-2 was not expressed in the normal salivary glands. 2. CMP-1 was immunolocalized in the ductal cell and cuboidal neoplastic myoepithelial cells around the chondroid areas of the pleomorphic adenomas, whereas these molecules were not localized in the spindle-shaped neoplastic myoepithelial cells of the myxoid element in these tumors. CDMP-2 was expressed neither in normal salivary glands nor in any elements of the pleomorphic adenomas. 3. In transmission electron microscopic view, the tumor cells are composed of modifed myoepithelial cells between hyaline and myxoid stroma. 4. In Immuno-blot analysis, strong overexpression of CDMP-1 was frequently seen in pleomorphic adenomas, but the level of CDMP-2 was expressed minimally in pleomorphic adenoma. From the these results, it should be suggested that undifferentiated neoplastic myoepithelial cells around the chondroid areas expressed CDMP-1 and suggested that this molecule may play a role in the differentiation of neoplastic myoepithelial cells in pleomorphic adenoma, but not CDMP-2.

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.83-89
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• 2021

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by presence of α-synuclein-positive inclusions in the cytoplasm of oligodendrocytes. These glial cytoplasmic inclusions (GCIs) are considered an integral part of the pathogenesis of MSA, leading to demyelination and neuronal demise. What is most puzzling in the research fields of GCIs is the origin of α-synuclein aggregates in GCIs, since adult oligodendrocytes do not express high levels of α-synuclein. The most recent leading hypothesis is that GCIs form via transfer and accumulation of α-synuclein from neurons to oligodendrocytes. However, studies regarding this subject are limited due to the absence of proper human cell models, to demonstrate the entry and accumulation of neuronal α-synuclein in human oligodendrocytes. Here, we generated mature human oligodendrocytes that can take up neuronderived α-synuclein and form GCI-like inclusions. Mature human oligodendrocytes are derived from neural stem cells via "oligosphere" formation and then into oligodendrocytes, treating the cells with the proper differentiation factors at each step. In the final cell preparations, oligodendrocytes consist of the majority population, while some astrocytes and unidentified stem cell-like cells were present as well. When these cells were exposed to α-synuclein proteins secreted from neuron-like human neuroblastoma cells, oligodendrocytes developed perinuclear inclusion bodies with α-synuclein immunoreactivity, resembling GCIs, while the stem cell-like cells showed α-synuclein-positive, scattered puncta in the cytoplasm. In conclusion, we have established a human oligodendrocyte model for the study of GCI formation, and the characterization and use of this model might pave the way for understanding the pathogenesis of MSA.

• Journal of Korean Medical classics
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• v.33 no.4
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• pp.1-19
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• 2020

Objectives : This paper aims to understand the meaning and utilitarian values of 'Jongyong(從容)' in medicine by studying its meaning in the 『Huangdineijing』. Methods : Examples of 'Jongyong(從容)' usages in Chinese literature and classical texts were studied first. Next, the similarities and characteristics of its contexts in discourses between Leigong and Huangdi were examined, followed by further examination of the overall meanings of the six chapters, 「Shicongronglunpian(示從容論篇)」, 「Zhuzhijiaolunpian(著至敎論篇)」, 「Shuwuguolunpian(疏五過論篇)」, 「Zhengsishilunpian(徵四失論篇)」, 「Yinyangleilunpian(陰陽類論篇)」, 「Jiejingweilunpian(解精微論篇)」 and the verses that include 'Jongyong(從容).' Results : Generally 'Jongyong(從容)' describes a resilient attitude that responds appropriately and calmly to difficult external situations while maintaining one's character, or refers to one's general behavior. In the 『Huangdineijing』, 'Jongyong(從容)' is only mentioned in discourses between Leigong and Huangdi, which talks about ancient East Asian clinical medicine in general, its transmission and education. Here, the meaning of 'Jongyong(從容)' could be summarized as an expansion of analogical thinking[引比類], medical work that involves the physician's commitment(人事), and detailed measurement of yinyang difference in the body(刑法, 陰陽, 治數). Discussion : In ancient East Asian medicine, the meaning of 'Jongyong(從容)' is closer to measurement of the yinyang difference rather than differentiation of the five element analogy. It is a medical practice that measures the shape, volume, length, area, height, concentration etc. of the human body in numerical figures to allow for the most subtle comparison, which was an important aspect of the physician's work that needed to be demonstrated, educated and transmitted to later generations to enable continuity of the medical profession.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.133-137
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• 2009

Pluripotent embryonic stem (ES) cells isolated from inner cell mass (ICM) of blastocyst-stage embryos are capable of differentiating into various cell lineages and demonstrate germ-line transmission in experimentally produced chimeras. These cells have a great potential as tools for transgenic animal production, screening of newly-developed drugs, and cell therapy. Miniature pigs, selectively bred pigs for small size, offer several advantages over large breed pigs in biomedical research including human disease model and xenotransplantation. In the present study, factors affecting primary culture of somatic cell nuclear transfer blastocysts from miniature pigs for isolation of ES cells were investigated. Formation of primary colonies occurred only on STO cells in human ES medium. In contrast, no ICM outgrowth was observed on mouse embryonic fibroblasts (MEF) in porcine ES medium. Plating intact blastocysts and isolated ICM resulted in comparable attachment on feeder layer and primary colony formation. After subculture of ES-like colonies, two putative ES cell lines were isolated. Colonies of putative ES cells morphologically resembled murine ES cells. These cells were maintained in culture up to three passages, but lost by spontaneous differentiation. The present study demonstrates factors involved in the early stage of nuclear transfer ES cell isolation in miniature pigs. However, long-term maintenance and characterization of nuclear transfer ES cells in miniature pigs are remained to be done in further studies.