• Applied Microscopy
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• v.30 no.1
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• pp.89-100
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• 2000

We observed the salivary ducts of two species of snails, Achatina fulica and Incilaria fruhstoferi with an electron microscope, and obtained the following results. The intralobular and interlobular ducts of Achatina fulica assume the forms of round or ellipsoidal doughnuts. The boundaries between the endothelial cells are not clear. It is also found that the cytoplasm of the endothelial cells consists of the membrane infolded in interdigital form, and there are well -developed microvilli at the apical portion of the cytoplasm. On the other hand, the intralobular and interlobular ducts of Incilaria fruhtoferi consist of the irregular simple columnar epithelia. The high electron dense cytoplasm is filled with the irregular round granules. The microvilli at the apical portion of the cytoplasm are not so well-developed as those in Achatina fulica. In the salivary duct of Achatina fulica, the lumen has narrow and long tubular structure. The boundaries between the endothelial cells are not clear. The cytoplasm is full of many vacuoles and electron lucent granules. At the apical portion of the cytoplasm, lots of short and thin microvilli are found. The salivary duct of Incilaria fruhstorferi is wider ($65\times250{\mu}m$ in diameter) than that of Achatina fulica, and consists of endothelial cells of the same structures. At the apical portion of those endothelial cells, a lot of junction apparatus such as desmosomes are observed. The vessels in the salivary ducts of Achatina fulica and Incilaria fruhstoferi are observed mainly in the connective tissues between the salivary glands. The endothelial cell of the vessel has the irregular structure and looks dark due to the high electron density. These cells protrude their filopodia and phagocytosize foreign bodies.

• ALGAE
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• v.28 no.2
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• pp.161-171
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• 2013

A morphologically distinct lineage within the Bostrychia moritziana-B. radicans species complex is described as a new species. Bostrychia anomala has thalli with branched monosiphonous filaments with apical cell divisions. The species has terminal tetrasporangial stichidia, each subtending cell bearing tetrasporangia with 2 cover cells. Discharged spores divide transversely, the lower cell first forming a narrow rhizoid and the upper cell forming a monosiphonous shoot. Females have subterminal procarps and males have terminal spermatangial stichidia. Carposporophytes are spherical. Isolates in culture show a pattern of cell death not associated with injury, reminiscent of programmed cell death. Bostrychia anomola shows cell death at intervals along the filaments resulting in division of adjacent cells on either side of the dead cell re-joining the filament; cell division of only one adjacent cell resulting in branching at that site; or filaments fragmenting at the cell death point with adjacent cells forming new apical cells, a means of thallus propagation. The cell death pattern could be a method of filament propagation in the mangrove environment where sexual reproduction is rare.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.845-847
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• 2009

In thecate dinoflagellates, the thecal plate pattern has been considered to be important criteria in their classifications. Due to this fact the shape of the theca and the arrangement of the theca were studied. In the pictures, the distinctions between the plates in the cells were so vague that I drew a diagram to illustrate the plate pattern. To identify the genus Protoperidinium, the shape of the first apical plate and the second anterior intercalary plate were used. Depending the shape of first apical plate, will be designated as meta(4), meta(5), para(4), para(5) or para(6). The shape of first apical plate is considered an important factor. From this point of view, the genus Protoperidinium as a group of planktonic protist in the coastal environment was classified.

• Animal cells and systems
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• v.7 no.2
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• pp.105-109
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• 2003

Morphological characteristics of nymphal instars are described for a Korean wood-feeding cockroach, Cryptocercus kyebangensis. Eleven instars, including adults, were tentatively identified. Female adults had apicolateral emargination and a truncated apical median prominence in the seventh sternite, and female nymphs of the other instars except for the last had a narrowly rounded apical median prominence in the seventh sternite. In the last instar, the seventh sternite was partially desclerotized and somewhat shriveled at the start of the emarginated area. In contrast, males showed no emargination in adults, and had a rounded broad apical median in this area of all instars. In the ninth sternite, female nymphs had a medium notch on the caudal margin and styli were separated before reaching adulthood, whereas no such notch was observed in male nymphs. The styli remained prominent in the ninth sternite of male adults.

• The Korean Journal of Physiology
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• v.30 no.1
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• pp.53-62
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• 1996

Transepithelial transport of tetraethylammonium (TEA) was studied in monolayers of opossum kidney cells cultured on permeable membrane filters. $[^{14}C]-TEA$ was transported across the OK cell monolayer from basolateral to apical side by a saturable process which can be stimulated by acidification of the apical medium. The apparent Michaelis-Menten constant $(K_{m})$ and the maximum velocity$(V_{max})$ for the transport were $41\;{\mu}M$ and 147 pmole/ mg protein/ min, respectively. The transport was significantly inhibited by unlabelled TEA, amiloride, cimetidine, choline, and mepiperphenidol added to the basolateral side at 1 mM and was slightly inhibited by 5 mM $N_{1}-methylnicotinamide\;(NMN).$ Unlabelled TEA added to the apical side stimulated the $basolateral-to-apical\;{^{14}C}-TEA$ transport, suggesting that the TEA self-exchange mechanism was involved at the apical membrane. Sulfhydryl reagents such as ${\rho}-chloromercuribenzoic\;acid\;(PCMB)\;and \;{\rho}-chloro-mercuribenzene\;sulfonate \;(PCMBS)$ and carboxyl reagents such as N,N'-dicyclohexylcarbodiimidem (DCCD) and N-ethoxy-carbonyl-2-ethoxy-1,2-dihydro-quinoline(EEDQ) inhibited the TEA transport at both the basolateral and apical membranes of the OK cell monolayer. These results suggest that OK cell monolayers possess a vectorial transport system for organic cations which is similar to that for organic cation secretion in the renal proximal tubule.

• Applied Microscopy
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• v.22 no.2
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• pp.84-96
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• 1992

This study was carried out to examine the $H^+$ transport mechanism by observing the properties of cellular membrane having an ${\alpha}$ type of carbonic anhydrase (CA)-containing cells in turtle urinary bladder. The urinary bladder consists of a heterogenous population of cells. As a result of fine observation with traditional thin-section electron microscopy. the bladder epithelium has three different cell types on mucosal surface. They are a basal cell, a granular cell and a third type of CA-rich cell. The CA-rich cells are divided into two distinct smaller groups within them and called them ${\alpha}$ type and ${\beta}$ type of CA cells. The ${\alpha}$ type of CA cells are responsible for the proton secretion using the proton pumps on the apical plasma membrane, while the ${\beta}$ type of CA cells secrete bicarbonate via an oppositely-directed proton pumps in their basolateral plasma membrane. After performing the freeze-fracture technique, it was shown that there were distributed a large number of intramembranous particles having a special structure on the apical membrane of ${\alpha}$ type of CA-rich cells in the process of their $H^+$ secretion. In turtle bladder ${\alpha}$ type of CA-rich cells, this particle was the only prominent structure in the apical membrane. These intramembrane rod-shaped particles probably represent the integral membrane components of the proton pump. This result may explain that carbonic anhydrase within epithelial cell of urinary bladder takes part in formation of $H^+$ and bicarbonate, that active transport of $H^+$ is done, and that the reabsorption of bicarbonate suggests transport mechanism containing $H^+$ secretion. However, it seems that more studies are required for considering their regular transport pathway.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.54-64
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• 1996

Normal development of the olfactory placode was studied to describe the sequence of events involved in the development of the olfactory placode. It has been primarily concerned with the morphological differentiation of the sensory neurons, their initial growth, maturation patterns and the contacts of their axons with the primitive prosencephalic vesicle. The olfactory organ first appears at stage 23 as a paired thickening of the two ectodermal layers: the superficial non-nervous layer (NNL) and the inner nervous layer (NL). Receptor cells differentiate from the NL and the supporting cells develop from the NNL. After stage 26 the placodal cells begin to migrate toward the epithelial surface between the NNL cells and their apical processes reach the surface at stage 28. As the apical process reaches the epithelial surface, basal processes (presumptive axons) sprout from the base of the NL cells at stage 29/30. They penetrate the underlying telencephalon by stage 32. Sensory synaptic contacts first appear at stage 37/38. Some placodal cells remain at the olfactory epithelium as basal cells while other placodal cells differentiate into olfactory neurons. The results confirmed that neurons originate exclusively from the nervous layer of the ectoderm while supporting cells originate from the NNL layer. The results also indicate that the development of olfactory neuron is independent of information from the target ftssue.

• Applied Microscopy
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• v.25 no.1
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• pp.75-85
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• 1995

The goal of the present study is to investigate the precise variation of tubulin substances in the cytoplasm of oviductal ciliated cells and the morphological changes in cytoplasmic organelles of ciliated cells for ciliogenesis by estrous cycles. The animals used in this study were female rat (Sprague Dawley strain), weighing approximately 200 gm. The ampulla oviducts of these animals (at each of estrous cycle) were rapidly excised. At each stage of estrous cycle, the tissues were used for immunocytochemical study and other were used for electron microscopical study. All specimens were observed by the light and electron microscope. The results obtained are as follows: 1. In the ciliated cells at proestrus, Golgi complex showed $5{\sim}7$ stacked cisternae with numerous saccules and vacuoles. Large amount of fibrous granules were located near the Golgi complex. But at metestrus and diestrus, few fibrous granules were seen. 2. A moderate number of rough endoplasmic reticulum and polyribosomes were scattered in the cytoplasm of ciliated cells at proestrus, but were decrease in number at metestrus and diestrus. 3. At proestrus and estrus, there were a large amount of vesicles in the apical cytoplasm of ciliated cells. 4. Numerous mitochondria were located in the apical cytoplasm at proestrus and estrus, but only a few at metestrus and diestrus. 5. At proestrus and estrus, tubulin substances showed strong reactions in the cytoplasm but weak reactions at metestrus and diestrus. It is suggested consequently that the ciliated cells of the rat oviducts showed no morphological changes of cilia but the ultrastructural organelles of the cells were changed in its shape and location during the entire estrous cycle.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.235-244
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• 1997

The present study was performed to investigate the patterns of appearance of lectin in trachea of fetuses of 60, 90 and 120 days old and neonates of Korean native goat. Carbohydrate markers were used in histochemistry for the determination of the lectin by staining of avidin-biotin-peroxidase complex(ABC), and the markers consisted of biotin-labeled concanavalin A(Con A), dolichos biflorus agglutinin(DBA), rincinus communis agglutinin(RCA-I), ulexeuropalus communis agglutinin(UEA) and wheat germ agglutinin(WGA). 1. The Con A-binding reactions appeared moderately on the apical surface of the tracheal epithelia in 60 days old fetuses, and the reactions were similar on the tracheal epithelia and glands in 90 and 120 days old fetuses and neonates. 2. Reaction of the DBA appeared as the strongest meanwhile the DBA-binding reactions were determined strongly on the apical surface of the tracheal epithelia in the 60 days old fetuses. Reaction for the DBA on the tracheal epithelia and glands of 90 and 120 days old fetuses and neonates were in same manner. 3. The RCA-I-binding reactions appeared very strongly on the apical surface of the tracheal epithelia in 60 and 90 days old fetuses. Reaction to the RCA-1 appeared moderately on certain apical surface of tracheal epithelia and glands in 120 days old fetuses and neonates. 4. No reactions provoked for the UEA in trachea of 60 days old fetuses and neonates, but the UEA-binding reactions appeared moderately in the tracheal epithelia of 90 days old fetuses and weakly in 120 days old fetuses. 5. The WGA-binding reactions appeared very strongly on the apical surface of the tracheal epithelia in 60 and 90 days old fetuses, and moreover, the reactions were determined on the luminal surface of the tracheal gland in 90 days old fetuses. On the other hand, goblet cells of the tracheal epithelia and glands in neonates reacted moderately to the WGA.

• Journal of Biomedical Engineering Research
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• v.17 no.3
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• pp.355-364
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• 1996

Construction of the stable monolayer of endothelial cells onto physicochemically modified polymeric surFace is one of the appropriate method to develop the small caliber vascular graft with the long-term patency. In this study, we constructed the monolayer of endothelial cells on the fibronectin rind the extracellular matrix-coated polyurethane surface derived from human fibroblast cells. To elucidate the adhesion strength of endothelial cells on the extracellular matrix-coated polyurethane, a laminar flow chamber apparatus was developed to exposure the shear stress on the apical membrane of ondothelial cells. Endothelial cells show the strongest adhesion after two days of seeding onto the fibronectin-coated polyurethane surface, whereas endothelial cells on the extracellular matrix derived from the human flbroblast cells show the minimal doubling time of cellular growth.