• The Korean Journal of Malacology
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• v.4 no.1
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• pp.1-16
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• 1988

The authors observed histochemical and ultrastructural characters on the osphradium of Rapana venosa Valenciennes using light microscope, scanning and transmission electron microscpes. The results were as follows:1)The basic structure of osphradium was bipectinated shape, which consisted of a septum situating in the center of osphradium and numerous osphradial leaflets. On the other hand, Epidermis of ospradial leaflets formed the structure of pseudostratified ciliated columnar epithelium which was composed of an epithelial cell layer, a basal cel layer and a neuropile. 2) Ciliated dpithelial cells:A large number of these cells were observed on the lateral and ventral regions but a small number of them were observed on the dorsal region. These cells had cylindrical microvilli, slender mitochondria and serve fibers.3) Supporting cells: These cells had cylindrical microvilli, spongy layer, electron dense granules, mitochondria and nerve fibers4) Four types secretory epothelial cells: Four distinct types of secretory epithelial cells were recognized and were arbitrily designated as Type I, Type II, Type III and Type IV.cell type I: These cells contained electron denwe granules(diameter, 0.94-1.56${\mu}{\textrm}{m}$), well developed Golgi apparatus and rough endoplasmic reticula, cell type II: These cills contained two types of granules of the different electron density. One was high electron density granules which were 0.4-1.0${\mu}{\textrm}{m}$ in diameter, The other was low electron density granules which were 0.75-1.2${\mu}{\textrm}{m}$ in diameter.cell type III:These cells had fibrous secretory materials and exhibited strongly positive reaction with Toluidine blue.cell type IV:A large number of this type of cells were observed on the ventral region of ospgradial leaflets and positively reacted with periodic acid Schiff reagent. 5)Dark cells contained several electron dense cillaty rootlets and unmerous granules but cellular organelles were not observed.6) Four types basal cells: Four distinci types of basal cells were recognized and arbitrarily designated as Type I, Type II, Type III and Type IV.Cell type I(light cell): These cells exhibited low electuon density and contained short smooth endoplasmic reticula, several vacuoles and granules.

• Applied Microscopy
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• v.25 no.3
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• pp.63-74
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• 1995

The development of pale chub oocyte from the immature oogonium to mature oocyte was investigated by light and electron microscope. The cytoplasm of pale chub oogonia was acidic and many vesicles were located at inner side of nuclear membrane. In primary oocytes, yolk vesicles were distributed in cytoplasm. Also, fibrous materials and protuberances were distributed on the surface of zona radiata. The nucleus of secondary oocyte was enlarged and yolk vesicles in cytoplasm migrated to zona radiata. In early egg, yolk mass are formed and yolk vesicles were located at inner side of zona radiata. Three-layered zona radiata was about $3{\mu}m$ in thickness. The three layers were an outer fibrous material layer, a middle nurse cell layer in which microvilli of early egg cytoplasm contact with processes of nurse cells, and an inner layer with high electron density. In mature egg, euchromatin and a germinal vesicle were developed, mitochondria, free ribosomes, and yolk mass were distributed in cytoplasm. But, yolk vesicles were disappeared. Specially, zona radiata of matured eggs were better thin than the one of immature eggs In conclusion, it is summerized that the oogenesis of pale chub were the increase of cell size, the formation and accumulation of yolk, the decrease in nucleat electron density, changes of zona radiata, and the development of microvilli.

• Toxicological Research
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• v.22 no.4
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• pp.375-380
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• 2006

Microcystin-LR (MC-LR) is a cyanobacterial hepatotoxin mainly produced by Microcystis aeruginosa. The current study examined the effects of a single intraperitoneal dose of MC-LR in rats. Female Sprague-Dawley rats were intraperitoneally injected with MC-LR ($100{\mu}g/kg$ body weight) and they were sacrificed at 0, 20, 40, 80, 160 min, or 12 h after injection. Clinically, animals showed lethargy and had ruffled hair beginning at 40 min post injection. In the gross findings, liver was enlarged and its color was changed into dark red beginning at 40 min post injection. Microscopically, dissociation of centrilobular hepatocytes and hemorrhage was observed in the hepatic central legions and such pathological changes were then extended to the portal regions of liver by time course manner. Interestingly at 80 min after MC-LR injection, the entrapped eosinophilic materials that may be necrotic fragments of dissociated hepatocytes were found in the capillaries of lung and renal glomerulus. Ultrastructurally, microvilli of the hepatocytes were disrupted or lost at all time points. Furthermore, the Disse space and gap junctions were widened beginning at 40 min post injection. These results suggest that liver is the major target organ of MC-LR and isolated hepatocytes by the effects of such hepatotoxin may secondarily reduce the physiological function of lung and kidney.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.69-76
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• 2011

Gill morphology and ultrastructure of the spiny top shell, Batillus cornutus were described using light and electron microscopy (SEM and TEM). The spiny top shell, Batillus cornutus has bipectinate gill. The epithelial layer of gill filament was simple and composed of columnar epithelium, ciliated cell, mitochondria-rich cell and secretory cell. Microvilli were well-developed on the free surface of columnar epithelial cell. The epithelial cells are connected to the neighboring cells with intercelluar junctions at the apico-lateral surface. The cilia and microvilli were commonly observed on the free surface of ciliated cell. Tubular mitochondria appeared in the apical cytoplasm, and connected ciliary rootlet. Mitochondria-rich cells contained a oval-shaped nucleus in the basal area. And majority of cytoplasm was occupied by well-developed mitochondria. Result of AB-PAS (pH 2.5) and AF-AB reaction showed that secretory cells contained mainly acidic carboxylated mucosubstances. Secretory cells are unicellular glands and can be divided into four types (A, B, C and D) depending on the cell shape and ultrastructure of secretory granules.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.519-535
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• 1997

The responses of human pulp fibroblastic cells to Ga-As Semi-Conductor-Dens-Bio Laser (Frequency: 5 Hz~10,000 Hz Model: SD-101A RCA, U.SA)) were examined in vitro using pulp fibroblastic cells obtained from the pulp tissue of human tooth. The mitogenic effect of soft laser was assessed by measuring the MTT assay. The morphologic effect for soft laser showed under the scanning and transmission electron microscopy. The results as follows; 1. The mitogenic response of the soft laser was not observed until 4th time of radiation, while the mitogenic response at 4th time increased mitogenic effect by as much as 1.7 fold compared to the control value. 2. The mitogenic response of the soft laser on pulp fibroblast differ from the mitogenic response on other fibroblasts. 3. In scanning electron microscopic study, The microvilli of cell surface increased gradually with width and length after laser radiation, it demonstrate that development of microvilli have close connection with differentiation of cells. 4. Under the transmission electron microscope, The laser-treated cells maintained their elongated shape and a high degree of cellular polarization. The large cell body containing a well developed Golgi complex, a large number of profiles of rough endoplasmic reticulum, and great numbers of mitochondria. 5. The laser-treated cells maintained the long straight bundles of closely apposed microfilaments or individual filaments forming a cross-linked network. These findings suggest that the laser may have important roles in promotion of pulp healing and consequently may be useful for clinical application in pulp regenerative procedures.

• Applied Microscopy
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• v.15 no.2
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• pp.98-110
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• 1985

This study was performed to clarify the morphological structures of the epithelia of the renal papilla, renal pelvis and ureter of the sheep (Ovis aries L.) through the light and scanning electron microscopes, Tissue specimens were taken from the renal papilla (common renal papilla and peripelvic column) and the renal pelvis (pelvis proper and pelvic pouch) of the kidney and the ureter. For the light microscopy, tissue blocks were fixed in 10 % neutral buffered formalin and embedded in paraffin wax, serially sectioned at a thickness of $6{\mu}m$. These sections were stained with hematoxylin-eosin and periodic acid-Schiff reaction. For the scanning electron microscopy, tissue blocks were prefixed in 1% glutaral-dehyde-1.5% paraformaldehyde solution and postfixed in 1% osmium tetroxide solution, dehydrated in graded alcohol, transferred to isoamyl acetate, and then dried by the critical point dryer (Polaron E 3000). These dried tissues were coated with gold and observed with a scanning electron microscope (JSM-35C), The results were as follows: The apex of the common renal papilla was lined with simple columnar epithelium having many microvilli on its luminal surface. Lateral portion of the papilla was lined with stratified epithelium $2{\sim}3$ layers thick, and its superficial cells were microvillar cells having many microvilli. The epithelium lining the peripelvic column was $1{\sim}2$ layers thick. The superficial layer was made of the microvillar cells, but a few microplica cells were appeared in the region near the pelvic pouch. The epithelium of the pelvic pouch was $1{\sim}2$ layered transitional type, and its superficial cells were microplica cells. The epithelia of the pelvis proper and ureter were $4{\sim}6$ layered transitional type, and their superficial cells were typical facet cells existing many round depressions and ridges of cell membranes of the luminal side.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.107-116
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• 2024

The study was conducted to examine age-related development of digestive organs, intestinal microvilli hydrolase, and hepatic antioxidant enzyme in Korean native chicks (KNC) aged from 0-d to 28-d of post-hatching. Body weight did not significantly increase from 0-d to 3-d-old, but after that remarkably increased from 3-d to 28-d-old (P<0.05). The relative weight (g/100 g of BW) of the proventriculus, gizzard, and liver was significantly higher at 3- and 7-d-old chicks than that of the other ages. The relative weight of the intestine, mucosal tissues, and pancreas was markedly developed at the ages of 3-, 14-, and (or) 21-d-old chicks (P<0.05). In the small intestine, the specific activities of maltase and sucrose were significantly higher at 14-d-old compared with the other ages (P<0.05). Leucine aminopeptidase activity showed a constant level from 0- to 28-d-old without significance. The specific activity of alkaline phosphatase was significantly higher at 0-d-old compared with the other ages (P<0.05). In the liver, the specific activities of superoxide dismutase, glutathione peroxidase, and glutathione S-transferase were shown to be lowest at 0-d-old, but they continued to increase as the age increased. The lipid peroxidation was significantly high at the age of 21-d (P<0.05), after that its level decreased at 28-d old. In conclusion, the KNC rapidly developed digestive organs and intestinal microvilli hydrolase activity from 3- to 14-d-old after hatching. Hepatic antioxidant enzyme activity continued to increase as the age increased after hatching, resulting in 28-d-old chicks showing the highest antioxidant enzyme activity in the KNC.

• Applied Microscopy
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• v.26 no.4
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• pp.401-410
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• 1996

The microwave fixator has recently been introduced in morphological research. The present study was carried out to investigate the ultrastructural effects of microwave fixation of rat brain. kidney, liver and skeletal muscle tissues. The results are as follows: In the case of microwave fixed cerebrum. the cytoplasmic processes of neurons and the various membranous organelles such as nuclear envelope, mitochondria, rough endoplasmic reticulum and Golgi apparatus were well preserved, The myelin sheath wrapping neuronal axon was prominent. Microwave fixed hepatocytes showed the microvilli on the free surface of bile canaliculus, the evident nucleolar components, and typical organelles. In nephron, ultrastructures of glomerulus and Bowman's capsule were preserved, and also tubular wall were structurally observed. Among the skeletal muscle cells, plentiful collagen fibers were appeared, myofibrils and mitochondria were typically observed. In conclusion, the microwave fixation procedures result in an good preservation of the tissues and would be time- and reagent-saving.

• Applied Microscopy
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• v.21 no.2
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• pp.14-28
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• 1991

The present study was designed in order to clarify ultrastructural characteristies of the spermatogenetic process and to examine survival state of the spermatozoa introduced into the female reproductive tract after autumnal coitus in the Korean greater horseshoe bats(Rhinolophus ferrumeguinum korai). The general morphological characteristics of spermatogenesis were principally similar to those of the other mammalian species; acrosomal formation, flagellar formation, middle piece formation and concentration of the spermatozoan nucleus. The spermatozoa introduced into the vagina were found to be dead forming a vaginal plug, the opaque central core of which consisted of trapped dead spermatozoa. Some spermatozoa introduced into the uterus were observed to be phagocytized by the polymorphonuclear leucocytes infiltrated into the uterine glandular lumen. The oviductal epithelium, consisted of ciliated and secretory cells; the luminal surface of secretory cells were covered by a number of microvilli with well developed glycocalyx, suggesting a close relationship to nutrient (e.g. glycogen) supply for the spermatozoa during hibernation.

• Applied Microscopy
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• v.28 no.3
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• pp.263-271
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• 1998

Oocyte maturation of the swordtail (Kiphophorus hellerii) was investigated by light and electron microscopy. In the ovary of the swordtail, various staged oocytes were observed, Mature oocytes were located in ovarian cortex, meanwhile immature ones were positioned in ovarian medulla. The oocyte was surrounded by several structures or cells such as chorion, follicle cells, follicular theaca and ovarian epithelium, respectively, from the inside toward outside. Growing and maturing oocytes healed numerous microvilli which interconnected the oocyte and the follicle cells to communicate each other. The mature oocyte had the electron dense chorion which appeared to be ultrastructure of two layers and contained pore canals. Oocyte maturation was characterized by not only the enlarged cell size and well differentiated cell organelles, brit also the increases of fat droplets, pinocytotic vesicles and yolk granules.