• Applied Microscopy
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• v.31 no.1
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• pp.101-108
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• 2001

Five kinds of neurosecretory cells (type-A, B, C, D and E) and neuropiles surrounding them were observed in the visceral ganglion and the right parietal ganglion of the African giant snail, Achatina fulica, by transmission electron microscopy. Type-A cells (diameter, $35{\mu}m$) are the most popular cells in the cortex of the two ganglions, which are of triangular or irregular forms. In their cytoplasm, there are found large granules of 1 fm in diameters and small round granules of about $0.1{\mu}m$ in diameters. Small granules are classified into the ones of high electron density and the others of middle electron density. Type-B cells (diameter, $19\times12{\mu}m$) are evenly distributed over various portions of cortex and medulla of the two ganglions. They are similar to type-A cells in shapes. The cytoplasm of type-B cells is crowded with high electron dense granules of about $0.1{\mu}m$. Round granules of about $0.7{\mu}m$ in diameters are also found but rarely. Type-C cells are the smallest cells whose sizes are about $8\times6{\mu}m$. Each of them contains a large nucleus of about $6\times5{\mu}m$. Its cytoplasm is full of electron dense granules of about $0.23{\mu}m$, each of which is artually an assembly of tiny granules of about $0.03{\mu}m$. Type-D cells are middle-size cells of about $28\times20{\mu}m$, which take ellipsoidal or irregular forms. They are found in the cortex more than in the medulla. Their cytoplasm looks dark due to the high electron density and, in it, two kinds of round granules whose sizes are $1.6{\mu}m$fm and $0.6{\mu}m$, respectively, are observed. Type-E cells are large cells of about $100\times50{\mu}m$, which are rarely found in the upper and middle portions of the two ganglions. The nucleus of the cell, which is very large $(70\times30{\mu}m)$ for the cytoplasm, contains electron dense round granules of diverse sizes (diameters, $1\sim0.2{\mu}m$). The surface of the cell protrudes filopodia of various forms and phagocytizes decrepit cells. Neuropiles are surrounding the neurosecretory cells. In nerve fibers, synaptic vesicles are observed, which are classified into six classes according to their electron densities , sizes and shapes.

• Journal of Gastric Cancer
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• v.24 no.1
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• pp.69-88
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• 2024

This review comprehensively examines the diverse spectrum of gastric cancers, focusing on unusual or uncommon histology that presents significant diagnostic and therapeutic challenges. While the predominant form, tubular adenocarcinoma, is well-characterized, this review focuses on lesser-known variants, including papillary adenocarcinoma, micropapillary carcinoma, adenosquamous carcinoma, squamous cell carcinoma (SCC), hepatoid adenocarcinoma, gastric choriocarcinoma, gastric carcinoma with lymphoid stroma, carcinosarcoma, gastroblastoma, parietal cell carcinoma, oncocytic adenocarcinoma, Paneth cell carcinoma, gastric adenocarcinoma of the fundic gland type, undifferentiated carcinoma, and extremely well-differentiated adenocarcinoma. Although these diseases have different nomenclatures characterized by distinct histopathological features, these phenotypes often overlap, making it difficult to draw clear boundaries. Furthermore, the number of cases was limited, and the unique histopathological nature and potential pathogenic mechanisms were not well defined. This review highlights the importance of understanding these rare variants for accurate diagnosis, effective treatment planning, and improving patient outcomes. This review emphasizes the need for ongoing research and case studies to enhance our knowledge of these uncommon forms of gastric cancer, which will ultimately contribute to more effective treatments and better prognostic assessments. This review aimed to broaden the pathological narrative by acknowledging and addressing the intricacies of all cancer types, regardless of their rarity, to advance patient care and improve prognosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.2
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• pp.137-152
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• 1995

This study was designed to evaluate the bone formation capability of the bone substitute when compared with autogenic bone, freeze-dried demineralized allogeneic bone and bioglass into parietal bone of the rats. We made the parietal bone defects in $7{\times}7mm$ size on rats and has performed the bone graft in each experimental groups. Postoperatively 1, 2, 4, 6, 8, weeks, each specimen stained with H & E, Masson's trichrome methods. We evaluated the osteogensis capability in each groups. The result were as follow : 1. Inflammatory cell infiltration approached at 1 week and disappeared at 4 weeks in all experimental group, expecially severe in freeze-dried demineralized allogeneic bone group. 2. New capillry proliferation was increased in autogeneic bone graft group than any other groups and was increased till 2 weeks and decreased in freeze-dried demineralized allogeneic bone group and was few in bioglass group. 3. Osteoblastic activity increased in autogeneic bone and freeze-dried demineralized allogeneic bone groups till 4 weeks, and decreased in 6 weeks which no difference between these groups. But, few occurred in bioglass group till 6 weeks. 4. Initial osteoclastic activity was prominent in freeze-dried demineralized allogeneic bone group and few in autogeneic bone group. 5. New bone formation bega at 1 week in autograft and freeze-dried demineralized allogenic bone groups, but, mild new bone formation at 8 weeks in bioglass.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.219-227
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• 1994

The development of abomasum in fetuses between 60, 90, 120 days of gestation and neonates of Korean native goats was investigated by light, scanning and transmission electron microscopy. The results obtained were summarized as follows ; 1. The abomasum wall appeared to be differentiated into the epithelium, lamina propria, muscle layer, and serosa at 60 days of gestation. The epithelium was stratified columnar and these nuclei were located near the apical two thirds portion of the cell at 60 days of gestation, and then transformed into simple columnar epithelium with the flat basal nuclei. 2. The inner circular and outer longitudinal muscle layers were observed at 90 days of gestation and the blood vessels had become quite well developed as various arterioles, venules and capillaries of different size during this age. 3. Gastric pits were seen at 90 days of gestation and continued gradually to increase depth during gestation. 4. The mucous, parietal and chief cells appeared in epithelium at 90 days of gestation and continued gradually to increase in number during gestation. In 120 days fetuses and neonates, muscle layer had become very thickeness. 5. Scanning electron microscopically, the inner surface of the abomasum already consisted of wavy spiral folds which had many fine wrinkles at 60 days of gestation. In 90 day old fetuses, each spiral fold was enlarged and its surface was tended to be split into many straight longitudinal ridges and among these ridge were found shallow grooves, At 120 days, the subdivided swellings of ridges were progressively complicated in shape. In the neonates, the inner surface was flat and holed with many gastric pits. 6. Transmission electron microscopically, the epithelium was straified columnar and these nuclei were irregular shape at 60 days fetus. The parietal, chief and mucous cells were observed in 90 day old fetuses and continued gradually to increase in number during gestation. 7. The development of the abomasum was relatively slow at early stages, it was accelerated greatly in the last of gestation.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.41-57
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• 1997

This study was carried out to investigate the effect of selenium on the adriamycininduced renal lesions in male Sprague Dawley rats. A total of 60 Sprague-Dawley male rats were divided into 2 control groups(C1: saline, C2: selenium) and 2 treatment groups(T1: adriamycin, T2: adriamycin+selenium). The rats of the C1 and T1 groups were given normal saline(0.15ml/rat), the rats of the C2 and T2 groups were given sodium selenite(0.5mg/kg) intraperitoneally three days a week for 4 weeks. The treatment groups were dosed intraperitoneally with adriamycin(2mg/kg/day) five days at the second week. Animals were sacrificed at the 1st week, 2nd week and 3rd week after dosing with adriamycin. The morphologic abnormalities of the glomeruli and tubules in the kidney of male rats were examined histopathologically and electron microscopically.The results obtained were as follows : The mean body weight of adriamycin dosed group was significantly decreased as compared with that of control group at 4th week(p<0.05). In adriamycin and selenium dosed group, the mean body weight was decreased until the end of 2nd week but gradually increased from 3rd to 4th week. The histopathological findings of the renal corpuscle in adriamycin dosed group were parietal epithelial cell proliferation, vacuolization of glomerulus, and thickened basement membrane of the parietal epithelium. Proximal convoluted tubules were significantly dilated and the lumens were filled with renal cast. These lesions were generally not very significant in the rats given adriamycin and selenium. The electron microscopical findings of the renal glomerulus in the adriamycin dosed group were focal loss and fusion of the pedicels of the podocyte, and some vacuoles in the cytoplasm of the podocytes. There were numerous cytoplasmic vacuoles in the proximal and distal convoluted tubular cells. However, these ultrastructural changes were not significantly observed in the renal tubules of the rats of adriamycin and selenium dosed group. These results suggest that selenium may act as an inhibitor of the renal lesions induced by adriamycin in male rats.

• Molecules and Cells
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• v.38 no.12
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• pp.1079-1085
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• 2015

Originally, activins were identified as stimulators of FSH release in reproduction. Other activities, including secondary axis formation in development, have since been revealed. Here, we investigated the influence of activin ${\beta}_A$ on the body, including the gastro-intestinal (GI) tract. Initially, the activin ${\beta}_A$ protein was detected in the serum proportional to the amount of pCMV-rAct plasmid injected. The induced level of activin ${\beta}_A$ in muscle was higher in female than male mice. Subsequent results revealed that stomach and intestine were severely damaged in pCMV-rAct-injected mice. At the cellular level, loss of parietal cells was observed, resulting in increased pH within the stomach. This phenomenon was more severe in male than female mice. Consistent with damage of the stomach and intestine, activin ${\beta}_A$ often led to necrosis in the tip of the tail or foot, and loss of body weight was observed in pCMV-rAct-injected male but not female mice. Finally, in pCMV-rAct-injected mice, circulating activin ${\beta}_A$ led to death at supraphysiological doses, and this was dependent on the strain of mice used. Taken together, these results indicate that activin ${\beta}_A$ has an important role outside of reproduction and development, specifically in digestion. These data also indicate that activin ${\beta}_A$ must be controlled within a narrow range because of latent lethal activity. In addition, our approach can be used effectively for functional analysis of secreted proteins.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.345-353
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• 2002

Bone morphogenetic proteins(BMPs) are secretory signal molecules which have a variety of regulatory functions during morphogenesis and cell differentiation. To evaluate roles of BMPs and their receptors on mouse sagittal suture development, we have examined their expression patterns in serial sections of sagittal sutures by in situ hybridization during embryonic stages(E15-E18). BMP-2 and BMP-3 were expressed in the osteogenic front and parietal bone on embryonic 15day, from E16 in hair follicle. BMP-4 was strongly expressed in the osteogenic front and weakly expressed in the mesenchyme and parietal bone. BMP-S was expressed in the hair follicles. BMP-6 was not expressed in this study. BMP-7 was expressed in parietal bone during embryonic stage. BMPR-IB was expressed in the osteogenic front, but BMPR-IA was not. From these datas, we suggest that the BMP-4 regulates the early commitment of mesenchymal cells to the osteogenic lineages, the BMP-2 and BMP-3 may be involved in regulating the differentiation of osteoblast precursor cells. BMP-7 was involved in maintenance of differentiated osteoblasts. BMPs were key signaling molecules that regulate early calvarial bone morphogenesis, mediated by BMPR-IB.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.652-663
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• 1999

Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of the interactions between different tissues within the cranial sutures. Interestingly, point mutaions in the genes encoding for the fibroblast growth factor receptors(FGFRs), especially FGFR2, cause various types of human craniosynostosis syndromes. To elucidate the function of these genes in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of FGFR2(BEK) and osteopontin, an early marker of osteogenic differentiation, in the sagittal suture of calvaria during embryonic(E15-E18) and postnatal stage(P1-P3). FGFR2(BEK) was intensely expressed in the osteogenic fronts, whose cells undergo differentiation into osteoprogenitor cells that ultimately lay down the bone matrix. Osteopontin was expressed throughout the parietal bones excluding the osteogenic fronts, the periphery of the parietal bones. To further examine the role of FGF-mediated FGFR signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of FGF2 soaked beads onto both the osteogenic fronts and mid-mesenchyme of sagittal suture after 36 hours organ culture resulted in the increase of the tissue thickness and cell number around FGF2 beads, moreover FGF4-soaked beads implanted onto the osteogenic fronts stimulated suture closure due to an accelerated bone growth, compared to FGF4 beads placed onto mid-mesenchyme of sagittal suture and BSA control beads. In addition FGF2 induced the ectopic expression of osteopontin and Msx1 genes. Taken together, these data indicate that FGF-mediated FGFR signaling has a important role in regulating the cranial bone growth and maintenance of cranial suture, and suggest that FGF-mediated FGFR signaling is involved in regulating the balance between the cell proliferation and differentiation through inducing the expression of osteopontin and Msx1 genes.

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.269-272
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• 2017

Myxoid solitary fibrous tumor (SFT) is very rare soft tissue neoplasm. It is microscopically composed of spindle cells which is individually separated by delicate band of collagen fibers. And this tumor cells are immunohisto-chemistrically highlighted by CD34. Myxoid SFT has indolent clinical course and a good prognosis, so it is important to make a diagnosis because of its morphological similarities to myxoid spindle cell neoplasms that have different prognoses and treatment. We report the case of a 20-year-old female with a myxoid SFT found in the left temporo-parietal scalp. This case report appears to be the first reported scalp occurrence of this rare tumor.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.329-334
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• 2017

A marine ulvalean species (Chlorophyta) was collected from Imgok, which is located on the eastern coast of Korea. This species is morphologically characterized by distromatic, filiform to strap compressed or tubular thallus. Many branches were found near the base, but lacked proliferations. Cells were longitudinally aligned in the younger part of the branch and were disordered in the older part of the branch. A cap-like parietal chloroplast with one or two pyrenoids was contained in each cell. In a phylogenetic tree based on ITS and rbcL sequences, this species was nested in the same clade as Ulva torta and U. clathratioides from Australia, but formed a sister clade to U. torta from Japan. However, the genetic divergence between them was included in an intraspecific variation range within Ulva. This finding suggests that U. clathratioides should be reduced to a synonym of U. torta. Accordingly, the Korean alga was identified as U. torta based on the morphological and molecular data. This investigation is the first record of U. torta in the Korean marine algal flora.