• Applied Microscopy
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• v.30 no.1
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• pp.73-80
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• 2000

Di-(2-ethylhexyl)phthalate (DEHP) has been known as one of endocrine disruptors. The present study was carried out to investigate the alterations of fine structure in rat seminal vesicle after oral intubation of DEHP in dosages of 1g/kg/day, 2g/kg/day or 3g/kg/day respectively in 0.5 ml of corn oil for If days. In rats treated with DEHP for 15 days, seminal vesicle exhibited extensive histological alterations compared to those observed in control groups. The size of the seminal vesicle and the mucosal folds decreased, but the lamina propria was considerably thickened. The ultrastructural changes of epithelial cells in seminal vesicle of rat treated with DEHP were characterized by the high nuclear/cytoplasmic ratio and the increased beterochromatin within irregular nuclear envelope. And also, the rough endoplasmic reticulum, Golgi complex and secretory vesicles were poorly developed. In conclusion, DEHP caused the ultrastructural and functional alterations of seminal vesicle in rats dose-dependently. It is suggested that these detrimental effects of DEHP on seminal vesicle are derived from the decrease level of testosterone.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.224-238
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• 1992

Hepatic fibrosis was induced in Sprague-Dawley rats to evaluate the ultrastructural changes of fat-storing cells(Ito cells). For experimental induction of liver fibrosis, the rats were administered intraperitoneally with 0.5ml of 50% $Ccl_4$ solution per Kg body weight, twice weekly for 12 weeks. The rats were sacrified every week. The liver tissues were examined under light and eletron microscopes. And the immunohistochemical study of desmin was also performed. The results were summarized as follows : Light microscopic findings : The cellular infiltrations with inflammatory cells and Kupffer cells developed from 1 week after $Ccl_4$ injection, and were the most severe in 4 weeks. The strong immunoreactivity for desmin was also evident in 4 weeks. The centrilobular necrosis and fibrosis developed from 2 weeks after injection, and the necrosis persisted until 8 weeks. The progress of fibrosis was accompanied by decreases in cellular infiltration and reactivity for desmin, and increased gradual nodular formation was also observed. The cirrhosis was developed after 10 weeks. Electron microscopic findings : An increase in number of fat-storing cells was observed from 1 week after injection. Transitional cells characterized by a depletion of lipid droplets and a hypertrophy of the rER appeared after 2 weeks. The number of transitional cells with abundant collagen fibers in the extracellular spaces increased in 4 weeks. With progression of fibrosis the number of fat-storing cells decreased and proliferating fibroblasts with dilated rER were observed. According to these results it was revealed that there was an apparent transition from fat-storing cells to transitional cells and to fibroblasts. These cells had a few similar characteristics and may belong to the same cell population. Thus it was suggested that fat-storing cells might play an important role in hepatic fibrosis.

• The Korean Journal of Malacology
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• v.26 no.1
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• pp.63-78
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• 2010

The purpose of this study was to investigate the effect of tributyltin (TBT) on histopathological and ultrastructural changes in the digestive gland structure of the equilateral venus, Gomphina veneriformis. Experimental period was 36 weeks. Experimental groups consist of control condition and 3 TBTCl exposure conditions (0.4, 0.6, $0.8\;TBTC\;{\mu}g\;L^{-1}$). Outer envelop of the visceral mass of G. veneriformis exposed to TBTCl was observed disappearance of microvilli and cilia, decrease of mucous cell and partially destruction of epithelium. In the digestive gland showed an increase of number of hemocyte and mucopolysaccaride near the digestive tubule at early time of the exposure. Especially, in $0.8\;TBTC\;{\mu}g\;L^{-1}$ group, collapse of digestive tubule with modification of epithelium was observed. TEM observation revealed the numerous glycogen granules in epithelium of the outer envelop and connective tissue. In the ciliated cell of the primary duct formed the cilia in cytoplasm. Basophilic cell was observed destruction of the rough endoplasmic reticulum and mitochondria. Also, nucleus in the epithelium of the digestive tubule was disappeared heterochromatin and nucleolus, and condense. As the concentration of TBTCl increased, the accumulation of lipofucin increased in the digestive gland, but the collapse of digestive tubule induced a decrease of accumulation of lipofuscin.

• Applied Microscopy
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• v.27 no.3
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• pp.265-279
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• 1997

This study aims to demonstrate the effect of chitosan, one of the natural chelator, on the ultrastructural changes in the mouse liver caused by cadmium. A total of 60 healthy ICR that weighted 30 gm $({\pm}2gm)$ was used for experiment. The experimental group was divided into three groups; group A, B, and C. The group A and B administrated cadmium (4.0 mg/kg) to the intraperitoneal after pretreated with chitosan (0.5% solution) for 30 and 7 days, respectively. Each group was observed at 12, 24, 48, 72 hours and one week after injected cadmium. The results were as follows: 1. Group A The nuclear membrane and the chromatin were normal shapes at overall the time. The inner and outer membranes of the mitochondria damaged a little but almost normal in shapes. And electron-density showed slightly compacted. some enlarged rER (rough endoplasmic reticulum) showed at 12 hours. At 48 hours, typical lamellae of the rER were reformed, and a lot of transvesicles observed around them. To 48 hours, sER (smooth endoplasmic reticulum) was slightly dilated. From 72 hours, sER rehalizated in normal shape. 2. Group B Nuclear membranes were rounded-shape and chromatin showed evenly. To 72 hours, a lot of mitochondria observed around rER and development of cristae showed weakly. But at one week, cristae were clear and electron-density of matrix showed high. At 72 hours lamellae of rER showed some broken, but were reformed at one week. Also at one week, glycogen granules evenly showed over cytoplasm. 3. Group C At 12 hours, Nucleus showed the condensation of nuclear membrane and clear condensation at 24 hours. However, nuclear membrane had a slightly rounded-shape from 72 hours. From 12 hours to the one week, mitochondria showed the dilation of inner cavity and weak development of cristae. Also electron-density of matrix was a little low. Occasionally, destruction of inner and outer membrane observed at one week. The dilation of cisternae and destruction of lamellae of rER showed from 12 to 48 hours. From 72 hours, rER showed slightly dilated only. And lamella observed at one week. In sER, dilation of inner cavity was observed during whole period. These results suggest that chitosan attenuates the toxic effect of the cadmium in the mouse liver.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.261-267
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• 1996

To examine the potential utilization of chitosan, the biodegradable natural polymer, as a control agent of apple white rot caused by Botryosphaeria dothidea in a new control measure by coating it on the diseased branches, the various antifungal activities of chitosan was investigated. Chitosan showed significant inhibitory effect on the mycelial growth of B. dothidea, along with the morphological changes including hyphal swelling and ultrastructural changes on solid PDA medium. In liquid PD broth medium, the chitosan showed more significant effect on the growth of B. dothidea also forming cell clusters indicating affection on the hyphal extension. The growth of B. dothidea was inhibited more than 90% at the concentration of 1.0 mg/ml. Chitosan also detained the spore germination and induced the morphological change of germ tubes. Glucosamine, monomer of chitosan, did not affect on the growth of B. dothidea indicating the antifungal activity was caused by chitosan polymer.

• Applied Microscopy
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• v.24 no.1
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• pp.114-122
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• 1994

Drastic changes were observed in egg chamber during oogenesis of Aedes togoi immediately after blood meal. The egg chamber, in which the oocyte remains at previtellogenic stage before blood meal, shows very little change in size even for 3 days after emergence but increased 25 folds in volume within 60 hours after blood meal, presumably due to rapid yolk formation. Upto 6 hours after blood meal structures considered to be the precursor of the yolk granules were not observed in the space between follicle cells and oocyte. Vitelline bodies, which are similar to dense bodies secreted from follicle cells, appeared in the space at 10 hours after blood meal. Although vitelline bodies were fused to form vitelline layer, these bodies seem to contribute to the formation of yolk granules. Nurse cells are connected to oocytes by cytoplasmic bridge before blood meal, but the cells are absorbed into oocyte at 6 hours after blood meal.

• Applied Microscopy
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• v.26 no.3
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• pp.369-377
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• 1996

Ultrastructural changes of chloride cells in the gill from seawater-adapted killifish (Orizias latipes) were studied with a transmission electronmicroscope. Chloride cells contain many mitochondria and specifically developed tubular systems. Apical pits, formed by several neighboring chloride cells, were exposed to the environment. Degeneration and death of the chloride cells by apoptosis occurred more frequently than by necrosis. Apoptotic chloride cells shrank, became to apoptotic bodies, and eventually were phagocytosed and digested by the microphages around them. We conclude that apoptosis plays an important role in increased cellular turnover of chloride cells for the osmoregulation caused by changes in salinity of the environment.

• Applied Microscopy
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• v.9 no.1
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• pp.21-34
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• 1979

The cyclic changes of the epithelium of seminiferous tubule in the Korean greater horseshoe bat (Rhinolophus ferrumequinum korai) were investigated by means of the light and electron microscopic observations and the following results were obtained. 1) The spermatogenic function of the horseshoe bats captured in September was moderate but considerable amount of the ultrastructural findings were obtained in both the spermatocytogenic and the spermiogenic phases. 2) The spermatogenic function of the horseshoe bats captured in December was depressed representing a resting status. 3) The light and electron microscopic findings suggest that the epithelium of seminiferous tubule varies cyclically, which is closely related to their peculiar way of reproductive habit during hibernation.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.91-96
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• 1998

In relation to cold acclimation, this experiment was carried out to understand the changes of the cortical cells in the living barks of the mulberry during wintering period. The living barks of three mulberry varieties(Kaeryangppong, Shinilppong and Yongcheonppong) were sampled from December, 1995 to March, 1996. The result of this experiment was summarized as follows. The cortical cells in the living barks of the mulberry in December were filled with small vacuoles. Plastids and mitochondrias were located near the nucleus. At this time, almost all starch granules disappeared from the plastids. In January and February, mitochondria, palstids and microbodys of the cortical cell were observed. As increasing temperature from March, dictysomes and polysomes were sparse. Again, starch granules disappeared were observed in the plastids. From the above result. starch granules in plastide of the cortical cell of the mulberry disappeared during cold acclimation stage. After late January, Proplastid was observed in the cortical cell and the ultrastructures of cortical cell were actively changed.

• Journal of Plant Biology
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• v.37 no.3
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• pp.285-292
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• 1994

Ultrastructural changes in Panax ginseng C. A. Meyer mesophyll chloroplasts and variation of thylakoid membrane protein in responce to the light intensity were studied in leaves of two-y-old plants exposed to two different light intensities under field coditions. The leaves were allowed to function for three months after emergence under two contrasting light conditions. The ginseng chloroplasts of 5% light were filled with highly stacked grana of condensely arrayed thylakoids, so that the stroma space was hardly observed. In contrast, chloroplasts from leaves at 100% sunlight had fewer thylakoid membranes and smaller grana stacks. The number of osmiophilic globules increased. Total Chl content and Chl b content were lower at 100% sunlight than 5% sunlight. The thylakoid membrane proteins in the leaves grown at 100% sunlight showed lower CPIa, LHCII and CP29 than those with 5% sunlight. This effect was most obvious for LHCII. Polypeptides showed major bands at 90, 64, 29-30, 22 and 14 kD, and minor bands at 59, 58, 54, 52, 49, 46, 44, 35, 23, 21 and 18-19 kD. All these bands were lower in intensity in the leaves exposed to 100% sunlight. Moreover, the bands at 58-59, 46-47 and 23 kD disappeared.