• Journal of Aquaculture
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• v.17 no.1
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• pp.46-50
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• 2004

In the present study, attempts were made to cryopreserve sea urchin, Anthocidaris crassispina sperm in liquid nitrogen, to evaluate the effects of various cryoprotectants and freezing rates on motility, survival rate and fertilization rate of the post-thawing sperm, and the ultrastructural changes of sperm after cryopreservation were observed. The highest values of sperm motility (motility index: 3.3$\pm$0.37) and survival rate (72$\pm$3.5%) were obtained with 15% dimethyl sulfoxide (DMSO), and these values were significantly higher than those of sperm preserved with glycerol. Comparisons of motilities and survival rates between treatments of difference freezing rates showed that there was no difference between procedures (a) 5$0^{\circ}C$/min to -8$0^{\circ}C$ (motility index: 3.3$\pm$0.31 ; survival late 70$\pm$2.7%) and (b) 3$0^{\circ}C$/min to -8$0^{\circ}C$ (motility index: 3.1$\pm$0.29; survival rate 69$\pm$3.7%), while the results of (c) 1$0^{\circ}C$/min to -8$0^{\circ}C$ were significantly lower than the others (motility index: 2.2$\pm$0.33 ; survival rate 42$\pm$4.6%). There was no significant difference in fertilization rate between fresh sperm and sperm preserved with 15% DMSO as cryoprotectant and freezing rate (3$0^{\circ}C$/min to -8$0^{\circ}C$). Some ultrastructural changes of sperm, such as the detachment of plasma membrane, the destruction of mitochondria, and the flagellum rolling up head, were observed after cryopreservation. Morphological normality of the sperm in 15% DMSO frozen at the ratio of 5$0^{\circ}C$/min to -8$0^{\circ}C$ was better than the others.

• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.311-319
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• 1997

This study was carried out to investigate the ultrastructural changes of spermatozoa obtained from 20 of 3-year-old male chum salmon(Oncorhynchus keta) collected and analysed in middle October in 1995. The ultrastructural changes of gonad of fingerlings were examined to describe the sex differentiation of this species. The results obtained in this study were as follows : In spermatozoa, the nucleus is dense and homogeneous. Two spheroidal mitochondria(about 350nm long) are situated in parallel between the nucleus and the axoneme. Spermatozoa mitochondria are assembled into an organized sheath surrounding the outer dense fibres and axoneme of the flagellar midpiece. The sheath flagellum is situated beneath the base of the sperm head. The primordial germ cells of 6.8~7.2${\mu}{\textrm}{m}$ in size, which were buried under fibrous mesenchymal tissue between gut duct and notochord of larva with a total length of 2.4cm at 50 days after hatching. In juvenile of 10.5cm in total length at 70 days after hatching, the gonad was occupied by bundles of oogonia. The dense drumstick bodies(large arrows) are observed in the nuclei of the primordial gonad and surrounding tissue cells of fingerling at 70 days after hatching. The oval Barr bodies(asterisk) are observed in the nuclei of the primordial germ cells under the mitosis(2n). Note the large mitochondria, ribosomes and rough endoplasmic reticulum in the cytoplasm. Accordingly, the fingerlings at 70 days after hatching are identified as the female(xx). In result, the gonadal sex differentiation begins from the 70 days after hatching in chum salmon.

• Applied Microscopy
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• v.27 no.1
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• pp.87-100
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• 1997

To investigate the effects of mercuric chloride $(HgCl_2)$ on the differentiation of the cerebral neuron of chick embryo 10 days, the ultrastructural changes in nerve cells injected with a various doses of mercuric chloride were observed with transmission electron microscope. The enzyme activity of the some dehydrogenases, cerebral proteins and adenosine triphosphate (ATP) were also analyzed. The results obtained are as follows; The ultrastructural changes in 1.0 mg-injected group, the nuclear membranes were irregular, outer of mitochondria membrances dispressioned, their cristae were destroyed. In 2.0 mg-injected group, the nuclear envelops were destroyed and divided, were not observed organelle except of few ribosome, the RER and mitochondria. The number of polypeptide bands were separated by SDS-PAGE in the normal group were 38 bands. According to the in creased dose of mercuric chloride, contends of the bands were increased in 4 bands, but were decreased in 1 band. The activities of dehydrogenases were declined by increasing the dose of mercuric chloride. Lactate dehydrogenase (LDH) activity fatted to 61% in 2.0 mg-injected group. Malate dehydrogenase (MDH) activity fatted to 90% in 1.0 mg-injected group, greatly to 76% in 2.0 mg-injected group. Succinate dehydrogenase (SDH) activity decreased to 79% in 1.0 mg-injected group and greatly to 62% in 2.0 mg-injected group. ATP content in 1.0 mg-injected group was almost near to the normal level, but it was increased greatly in 2.0 mg-injected group.

• Journal of Plant Biology
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• v.35 no.1
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• pp.53-60
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• 1992

This study has been carried out to investigate the ultrastructural changes in the associated with the disintegration of the storage materials in endosperm cell of ginseng (Panax ginseng C.A. Meyer) seed during after-ripening with light and electron microscope. The protein body of endosperm cells near the umbiliform layer showed various degenerative patterns, and so electron density of proteinaceous matrix was gradualJy decreased during afterripening. These results indicate that the decomposition of endosperm was already initiated during after-ripening. As the degeneration of endosperm was more progressed after the dehiscence of seed, non-decomposed part of protein body appeared amorphously with high electron density. Decomposed protein bodies were vacuolized with the loss of their matrix and gradually expanded by fusion. Also, spherosomes were gradually dissolved with the lowered electron density during the degeneration of endosperm. The vesicles of dictyosomes near the cell wall are observed in endosperm contacting with umbiliform layer and are fused with plasma membrane. Umbiliform layer which was the complex of the decomposed remnants of lysis and materials has strong stainability for toluidine blue and basic fuchsin.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.257-265
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• 2000

Harderian glands are the unique organs in several mammals, which human and non-human primates do not have. We report the ultrastructural changes in the postnatal developmental periods of Harderian glands in Mongolian gerbil(Meriones unguiculatus). Male and female Mongolian gerbils were sacrificed on days 3, 10, 30 and 60 after birth and their Harderian glands were observed by transmission electron microscope. The obtained results were summarized as follows; 1. In 3-day-old Mongolian gerbils, Harderian gland was composed of one excretory duct and immature tubules which have two type cells, dark and light cells, identified electron-dense and electron-lucent respectively. 2. In 10-day-old Mongolian gerbils, small lipid vacuoles began to be found in the cytoplasm of the secretory cells of the Harderian gland. Mitochondria, Golgi apparatus, polysomes and slash were more abundant in the cytoplasm of dark cells than those of light cells. The arrangement of tubules in the gland was much more condensed than that of 3-day-old Mongolian gerbils. 3. In 30-day-old Mongolian gerbils, the secretory cells of the tubule were typically columnar in shape and there was one type cell in the tubule. Most of the columnar secretory cells contained various size vacuoles. 4. In 60-day-old Mongolian gerbils, the Harderian gland possessed the typical structural characteristics of adults. The mature glandular structures were more significant than those of 30-day-old animals.

• The Korean Journal of Zoology
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• v.38 no.4
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• pp.570-579
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• 1995

Ultrastructural and histochemical changes of mucous cells In the freshwater and seawater-adapted guppy (Poecflia reticulatus) gills were observed by the light, scanning-and transmisslon~lectron microscopes. The mucous cells were usually located in the epithelium of primary lameilne projected from the gill arch. The rough endoplasmic retIculum and Golgi complex were hIghly developed In immature mucous cells. The mature mucous cells were nearly filled with the mucous granules. In the freshwater guppy, the histochemical properties of the mucous cells were a mixture of the neutral mucin, sialomucin and sulfomucin. When guppy was adapted to the seawater, the content of acid glycoproteins (slalomucln and sulfomucin) was decreased. In addition, the number of mucous cells in the seawater-adapted group was less than a third of those in the freshwater one. These results suggest that the seawater-adapted guppy would react to the changed osmotic stress of the seawater. And also, the environmental change by the increased salt concentraion might lead to reduce the chance of infections.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.27-35
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• 1978

Ultrastructural changes in Z-line, M-line and myofilaments of bovine psoas muscle produced by leukocyte lysosomal enzymes in vitro at different pH values (pH 7.0 and 4.0), temperatures (37 and $4^{\circ}C$) and time intervals (12, 24 hours at $37^{\circ}C$ and 36, 168 hours at $4^{\circ}C$) were studied by transmission electron microscope. Muscle incubated with leukocyte lysosomal enzymes at pH 7.0 produced distinguishable degradation of Z-line, M-Line and H-zone at both temperatures but at acidic pH (pH 4.0), Z-line were very stable and myofilaments were severely disintegrated.

• Korean Journal of Food Science and Technology
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• v.10 no.1
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• pp.36-45
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• 1978

Surface ultrastructural changes in endomysial connective tissue, sarcolemma and transverse ridges of bovine psoas muscle produced by leukocyte lysosomal enzymes in vitro at different pH (pH 7.0 and 4.0), temperature (37 and $4^{\circ}C$) and time interval (12, 24 hours at $37^{\circ}C$ and 36, 168 hours at $4^{\circ}C$ were studied by scanning electron microscope. Muscle incubated with leukocyte lysosomal enzymes at pH 7.0 produced severe degradation of endomysial and sarcolemmal connective tissue and transverse ridges but at pH 4.0 endomysial and sarcolemmal structures remain moderately stable and tranverse ridges are very stable even after 24 hours incubation at $37^{\circ}C$ and 7 days incubation at $4^{\circ}C$.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.617-628
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• 1998

In order to understand the pathogenetic mechanism of adult respiratory distress syndrome (ARDS), the role of phospholipase A2 (PLA2) in association with oxidative stress was investigated in rats. $Interleukin-1{\alpha}\;(IL-1,\;50\;{\mu}g/rat)$ was used to induce acute lung injury by neutrophilic respiratory burst. Five hours after IL-1 insufflation into trachea, microvascular integrity was disrupted, and protein leakage into the alveolar lumen was followed. An infiltration of neutrophils was clearly observed after IL-1 treatment. It was the origin of the generation of oxygen radicals causing oxidative stress in the lung. IL-1 increased tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC) in the bronchoalveolar lavage fluid, but mepacrine, a PLA2 inhibitor, did not change the levels of these cytokines. Although IL-1 increased PLA2 activity time-dependently, mepacrine inhibited the activity almost completely. Activation of PLA2 elevated leukotriene C4 and B4 (LTC4 and LTB4), and 6-keto-prostaglandin $F2{\alpha}\;(6-keto-PGF2{\alpha})$ was consumed completely by respiratory burst induced by IL-1. Mepacrine did not alter these changes in the contents of lipid mediators. To estimate the functional changes of alveolar barrier during the oxidative stress, quantitative changes of pulmonary surfactant, activity of gamma glutamyltransferase (GGT), and ultrastructural changes were examined. IL-1 increased the level of phospholipid in the bronchoalveolar lavage (BAL) fluid, which seemed to be caused by abnormal, pathological release of lamellar bodies into the alveolar lumen. Mepacrine recovered the amount of surfactant up to control level. IL-1 decreased GGT activity, while mepacrine restored it. In ultrastructural study, when treated with IL-1, marked necroses of endothelial cells and type II pneumocytes were observed, while mepacrine inhibited these pathological changes. In histochemical electron microscopy, increased generation of oxidants was identified around neutrophils and in the cytoplasm of type II pneumocytes. Mepacrine reduced the generation of oxidants in the tissue produced by neutrophilic respiratory burst. In immunoelectron microscopic study, PLA2 was identified in the cytoplasm of the type II pneumocytes after IL-1 treatment, but mepacrine diminished PLA2 particles in the cytoplasm of the type II pneumocyte. Based on these experimental results, it is suggested that PLA2 plays a pivotal role in inducing acute lung injury mediated by IL-1 through the oxidative stress by neutrophils. By causing endothelial damage, functional changes of pulmonary surfactant and alveolar type I pneumocyte, oxidative stress disrupts microvascular integrity and alveolar barrier.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.403-410
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• 1994

The purpose of this study was to investigate the irradiation effects on the secretory granules of the rat submandibular gland acinar cell. For this study, Sprague-Dawley strain rats were irradiated to their neck region with the dose of 5Gy and l0Gy by 6MV X-radiation, and sacrificed on the experimental periods after irradiation. The authors observed the ultrastructural changes of the secretory granules of the rat submandibular gland acinar cell under a trasmission electron microscope. The results were as follows: In the transmission electron microscopic examination, secretory granules were blurred in limiting membrane on the 3hours groups after irradiation. And they showed decrease in number, irregularities in shape and distributional pattern, and inhomogeneous internal electron density on the Iday and 3days groups. After then, these changes were recovered in shape and distributional pattern on the 14days groups, and changes of internal electron density and limiting membrane were recovered on the 28days groups after irradiation. Among the intracellular organelles, rough endoplasmic reticulum was scattered, but golgi complex was not changed. And such pathologic changes were earlier and more prominent in 10Gy irradiated groups than in 5Gy irradiated groups.