• Applied Microscopy
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• v.2 no.1
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• pp.7-15
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• 1972

The morphological and fine structural changes during the oogensis of Clonorchis sinensis were studied on the developing ovums in the ovary and ootype with electron microscope. Adult worms were removed from the hepar of the which and previously infected with metacercariae of Clonorchis sinensis. The ovary including the Mehlis' glands and an ootype from adult worm was prefixed for 1-2 hours in 1.25% glutaraldehyde buffered with 0.2M cacodylate at PH 7.2, secondarily fixed for 30 minutes in potassium bicromate and postfixed for an hour in 1% osmic acid buffered with 0.4M cacodylate at PH 7.2. After fixation tissues were dehydrated in an alcohol series, embedded in Epon 812 from propylene oxide and stained with saturated uranyl acetate and $Pn(NO_3)_2$ solution. Material was examined with a Hitachi HS-7S electron microscope. The periphery of the ovary, except for the posterior region, is made up of oogonia. As the oogonia divide they proliferate primary oocytes toward the central part of the ovary. After a period of growth the primary oocyte leaves the ovary and is penetrated by a sperm in the ootype. Sperm penetration immediately activates the primary oocyte to resume its meiotic activity. After the oocytes meiotic activity is completed, the pronuclei fuse to form a single cleavage nucleus which possesses two nucleoli. As the oocytes develop their cytoplamic materials are abundant; small mitochondria are abundant and often their profiles are more unmerous in one part of the cytoplasm than elsewhere; the granular endoplasmic reticulum becomes alveolar-sac form after it leaves the ovary it becomes stratified form. The reticulate Golgi apparatus is apparent in the developed oocyte. A little of cortical granules are distributed inside of the plasma membrane I oogonia and large quantity of cortical granules are arranged just inside of the plasma membrane of the primary oocyte and after fertilization they are disappeared with broken out.

• Applied Microscopy
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• v.35 no.2
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• pp.57-64
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• 2005

The ultrastructure and histochemical characteristics of the submandibular gland was examined in the big white-toothed shrew, Crocidura lasiura. A submandibular gland of Crocidura lasiura was a mixed gland composed of serous and mucous acinar cells. Secretory granules from the acini were discharged through the intercalated duct, the granular duct and the striated duct into the oral cavity. Serous and mucous acinar cells and granular duct cells had large amount of rough endoplasmic reticulum, free ribosome and prominent Golgi apparatus at the basal cytoplasm of the cell, and many granules at the apical cytoplasm. Oval type serous granules had a homogeneously pale round shape of bead at the center. Mucous granules were distinct from those of the other mammalian species having variety patterns with several dense bands into homogeneous pale matrix. A serous-like secretory granules and myelin-like body were observed in the cytoplasm and the lumen of granular duct cells. The myelin-like body is a characteristic structure only reported in the salivary glands of two shrews, Suncus murinus and C. dsinezumi. Striated duct cell had numerous well-developed mitochondria but secretory granule was not shown at all.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.331-348
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• 1994

The purpose of this study was to investigate changes in the shape and ultrastructure of the articular disc of the rat mandibular joint with aging. Mechanical stress applied to the articular disc changes during neonatal, suckling, juvenile, adult and senile stages. Mandibular joints of 6 groups of rats(1-, 7-, 17-, 27-, 55-day and over-1-year groups) were removed en bloc and processed for light and electro microscopic study. The changes in the shape of articular disc were examined by light microscope in each group. Structural and ultrastructural changes in the articular disc were examined by light and electron microscope in each group. The results were as follows : In the 1-day and 7-day groups, the articular disc was long and slender in shape and the articular disc was not fitted with the shape of the mandibular fossa and condyle. However' after that time, the anterior and posterior portions of the articular disc were more bulged and the middle portion was shorter and biconcave. Thus the articular disc was well fitted with the shape of the mandibular fossa and condyle. The cell density decreased with aging. In the l -day and 7-day groups, the Golgi apparatus, rough endoplasmic reticulum and free ribosome, which are involved in the synthesis of intracellular and extracellular matrix, were developed. In the 17-day, 27-day and 55-day groups, not only the cell organelles involved in the synthesis of the intracellular and extracellular matrix but also the cell organelles involved in the remodeling of the extracellular matrix(i.e., finger-like cell process, lysosome and mitochondria)were well developed. With advancing age, intracytoplasmic microfilaments were more accumulated and condroid cells increased. In the over-1-year group, the majority of cells of the articular disc were chondroid cells. The majority of cytoplasmic compartment were filled with intracytoplasmic microfilaments and cell organelles were not developed. Therefore, metabolic activities of the cell was markedly reduced and cells contained structures enduring mechanical stress, and cells which were in the process of degeneration were observed occasionally.

• Applied Microscopy
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• v.25 no.4
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• pp.83-103
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• 1995

This experiment was carried out to investigate the effects of telluric acid on the histological and fine structural changes in the rat liver. Fischer 344 rats($150{\sim}200gm$) were used in this study as control and experimental groups. Telluric acid(5 mg/100 gm of body weight) suspensed in olive oil was given intraperitoneally to the animals of the experimental group and only olive oil to those of the control group. At the intervals of 3, 6 and 12 hours, 1, 2, 3, 5, 10, 20, 30 and 60 days after administration, the animals were sacrificed, and livers were obtained from the rats. For light microscopic examination of the liver, sections($5{\mu}m$) were stained with hematoxylineosin(H-E). For electron microscopic examination of the liver, sections were stained with uranyl acetate and lead citrate, finally examined with Zeiss EM 109 electron microscopes. The results obtained were as follows. 1. In the control group, round nucleus. well developed mitochondria, Golgi apparatus, rough endoplasmic reticulum(RER) and numerous glycogen particles were observed in the cytoplasm of the hepatocyte. In the cytoplasmic membranes of the hepatocyte, sinusoidal surface had numerous microvilli and cellular surface is combinated adjacent hepatocyte with desmosomes. The RER cisterns were dilated and zymogen granules were fewer than those of the dark cells. Kupffer cells with irregular nuclear membrane were observed. Fat storing cell and collagenous fiber bundle were observed in the Disse space. 2. Kupffer cell, inflammatory cells in the connective tissue of hepatic triad and lysosome were increased in the 3, 6, and 12 hour experimental group comparing with that of the control group. 3. In the 1 day experimental group, infiltration of inflammatory cells in interlobular connective tissue, dilatation of sinusoidal capillary and increasing of Kupffer cell were observed. Atropic change of hepatocyte and aggregation of glycogen particles in the cytoplasm of hepatocyte were observed. In this group, desmosome near bile canaliculi and collagenous fiber bundle in the Disse space were increased comparing with that of the 12 hours experimental group. In the 2 days experimental group, desmosome, lysosome, peroxisome and collagenous fiber bundle were increased comparing with that of the 1 day experimental group. Furthermore, lamellated bodies were also seen in the cytoplasm of the hepatocyte. 4. In 3 and 5 days experimental groups, transformations of hepatic cell cord and degeneration of the hepatocyte were markedly inclosed comparing with the all experimental groups. And damaged RER and mitochondria. collagenous fiber bundle were also inclosed comparing with that of the 2 days experimental group. Autophagosome and fat storing cells with large lipid droplets were also observed comparing with that of the 2 days experimental group. Tight junction and desmosome between the hepatocytes were separated. These degenerating changes were severe through the all experimental groups. 5. In the 10 and 20 days experimental groups, arrangement of hepatic cell cords and cell organelles of hepatocytes were similar to those of the control group. However, aggregation of glycogen particles, dilatation of sinusoidal capillary and infiltration of inflammatory cells remained. 6. In the 30 days experimental group, the tissue findings were similar to those of the control grout. But lamellated bodies in some hepatocytes and lysosome were remained in the cytoplasms of the Kupffer cells. In the 60 days experimental group, these all changes were recovered as the control group. In conclusion, telluric acid would directly induce the degenerative and necrotic changes on the hepatic tissue. However, these changes were perfectly recoverd in the 60 days experimental group as the control group.