• Korean Journal of Microbiology
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• v.24 no.3
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• pp.197-203
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• 1986

Morphology and ultrastructure of protoplast fusion mode in Streptomyces lavendulae were studied by scanning and transmission electron microscopy. The isolated protoplasts were stable in some degree in hypertonic solution except that several protoplasts showed irregular morphology. Fusion events were occurred as follows; contact zone, fusion zone and separation zone were appeared sequentially. After formation of the separation zone, cytoplasm and DNA from both parents were mixed eventually. In the contact zone, two menbranes were still separated by electron transparent space. The contact zone changed to fusion zone by formation of fusion membrane that phospholipid molecules of two membranes were rearranged. Thereafter, nonmembraneous separation zone was formed by disappearance of fusion membrane. These changes were characterized by successive changes in typical membrane structure in fusion areas and by a progressive loss of bispherical shape.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.1-15
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• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.22-29
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• 2001

To evaluate the cutaneous injury in liver damaged rats by toluene application to the skin, toluene(35mg/㎤) was sequentially applied for 5 days to the dorsal skin of liver damaged rats with $CCl_4$ (6 times ever other day:0.1$m\ell$/100 g body weight-50% $CCl_4$in olive oil). The cutaneous ultrastructural changes were unexoectably not observed in liver from $CCl_4$-treated rats although necrotic liver damage appeared under light microscope. In these animals by the application of toluene to rat skin the cutaneous xanthine oxidase activity was significantly increased(p<0.05), but cytochrome P450 content was not different from that of the control or only $CCl_4$-treated rats. On the other hand, the cutaneous superoxide dismutase and catalase activities in liver damaged animals were significantly respectively(p<0.05, p<0.001), decreased by toluene application to the skin compared with control and especially the former enzyme activity was significantty decreased(p<0.01), compared with that of liver damaged rate rat but glutathione peroxidase, glutathione-S-transferase activities were not significantly different from those of the control or liver damaged rats. Futhermore, the reduced gluathione content of skin was also significantly decreased by toluene application to the liver damaged animals. In conclusion, the great deposits of cerrous peroxide and ultramorphological changes in skin tissue of liver damaged animals by toluene application may be responsible for the oxygen free radical.

• Applied Microscopy
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• v.28 no.4
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• pp.563-575
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• 1998

To investigate the changes during the differentiation of the cerebral neurons of chick embryo of tne embryogenic day (ED) 7 and 8, the ultrastructural changes in the cerebral neurons, the activity of dehydronases (LDH, MDH and SDH), protein expression profile and adenosine triphosphate concentration were analyzed. In ED 7 chick embryos, relatively large nucleus, centrally located nucleolus, evenly spread chromatin over nucleoplasm, and prominent nuclear envelope were observed. Oval-shaped mitochondria with well-developed cristae were present over entire cytoplasm. In ED 8 chick embryos, evenly spread chromatin over nucleoplasm, and prominent nuclear envelope were observed. In the cytoplasm, well-developed rough endoplasmic reticulum and Golgi complex were observed. In ED 7 chick embryos and ED 8 chick embryos, 31 polypeptide bands and 34 polypeptide bands were observed, respectively. The activities of dehydrogenases were lower in ED 7 chick embryos than in ED 8 chick embryos. LDH activity was 8.16 (ED 7) and 9.28 (ED 8), MDH activity was 7.98 (ED 7) and 10.10 (ED 8), and SDH activity was 5.49 (ED 7) and 7.14 (ED 8) respectively. The ATP concentration remained unchanged over ED 7 and 8.

• Applied Microscopy
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• v.28 no.4
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• pp.491-502
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• 1998

The present study was conducted to investigate the structural changes in rat cornea. Sixty eyes from one-day-old uneyed rats, fourty eyes from 4-weeks-old rats, and foully eyes from 10-weeks-old adult rats were used. With the increase of age, the epithelial layer was thickened by the addition of new successive cellular layers. Then, the new-born rat's epithelial cells formed a pentagonal shape, and the quality of decidual cells showed a high electron-density, although the boundary between cells was distinctive. The newly produced cells showed a low electron-density so that there was the distinctive difference between light and darkness. In Bowman's layer, collagen fibrils demonstrate a regularly arranged structure along with the age. In stroma's layer, the density of keratocytes was decreased and thereby Progressively flattened during the development. The collagenous layer of the adult rats was more distinctive than that of the new-born rats in a form of parallel alignment running vertically and horizontally.

• Applied Microscopy
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• v.45 no.3
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• pp.135-143
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• 2015

The aim of this study was to investigate effects on joint mobilization in neurochemical changes of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and nitric oxide synthase (NOS) of the spinal cord neurons after right knee joint immobilization (RKJI) and in ultrastructural changes of the femoral nerves innervating the muscles acting on RKJI. A total of 15 guinea pigs were used and divided into 5 groups. Immunohistochemistry was performed to detect NADPH-d and NOS. NADPH-d and NOS were not expressed in the ventral horn of control and experimental groups, but were expressed or not in the dorsal horn according to the duration of release after RKJI and the presence or absence of joint mobilization. Ultrastructures of the femoral nerves in experimental groups had partial demyelination and condensed clumps in axon. Effects on manipulative therapy after RKJI were confirmed from expression of NADPH-d and NOS in the dorsal horn of the lumbosacral spinal cord. Manipulative therapy was more effective against a long-term immobilization than a short-term immobilization.

• Applied Microscopy
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• v.18 no.2
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• pp.119-131
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• 1988

The purpose of this study was to investigate the differentiation and degeneration of neurons in developing chick embryo. The activity of acid phosphatase(ACP) was measured and cytochemical study of ACP and ultrastructural changes were observed in prosencephalon, mesencephalon and rhombencephalon from day 4 to day 19 of incubation. As a result, the activity of ACP of all brain region was tend to increase from day 4 to day 19. On day 13, activities of ACP of mesencephalon and rhombencephalon were increased greatly and activity of ACP was decreased each region on day 17. On electron microscopic examination, the reaction product of ACP were localized at GERL complex, lysosome, Golgi body and vacuoles of neurons. Morphologically, disrupted nuclear envelope, mitochondrial destruction, vacuolization and ribosomal crystalization were observed.

• Applied Microscopy
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• v.17 no.2
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• pp.41-54
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• 1987

This experiment was performed to investigate the acute and chronic effects of lead on cerebral cortex. In acute treatment, mouse were injected with lead acetate at dose of 0.3 mmole/kg body weight, and in chronic treatment, mouse were supplied 0.03 M lead acetate sol. in the place of water. After treatment, mouse were sacrificed at time intervals of 24, 48, 72, and 96 hours in acute treatment and at time intervals of 4 weeks and 8 weeks in chronic treatment. In acute treatment, acetylcholinesterase activity is reduced at 72 hours and recovered at 96 hours in homogenate, and reduced at 24 hours and recovered at 72 hours in crude synaptosomes. In chronic treatment, acetylcholinesterase activity is increased in young mouse but reduced in mother mouse. Ultrastructural changes were composed of swelling of Golgi apparatus, nerve terminals with diminished synaptic vesicles, and vacuolated myeline lamellae of myelinated axon.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1984-1989
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• 2006

Deacetylated chitosan oligosaccharide (COS) had effective antiprotozoal activity against Trichomonas vaginalis (Minimal Inhibitory Concentration, MIC 0.25%), whereas 80% acetylated cas showed no antiprotozoal activity (MIC > 1 %). an the other hand, 80% acetylated cas showed growth stimulatory activity against the protozoa. When T. vaginalis was treated with 98% deacetylated COS at 0.25% concentration, the viability of the protozoa was rapidly decreased within 15 min, and the protozoa completely died within 40 min. Ultrastructural changes of trichomonads treated with COS included a loss of defined nuclear membrane and endoplasmic reticulum membranes, an increase in the number of free ribosome, vacuolation, and ultimately lysis of the cell membrane. These results indicate that deacetylated COS can be used as an antitrichomonal agent, although its lethal mechanism is not known.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.111-116
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• 2002

This study investigated quantitative changes in the spaces between and within myofibrils and the impact of high and low voltage electrical stimulation on muscle ultrastructure as seen in electron micrographs. In addition, the relationships of these spaces and the impact to meat tenderness were investigated. The degradation of myofibrils during aging appeared to be localized across the muscle fibre. Structural deterioration of muscle fibres was evident 1 day post-mortem, involving the weakening in the lateral integrity of the myofibrils and Z-disc regions. Meat tenderisation, as shown by objective measurements, coincided with these increases in degradation, as assessed by the sum of the gaps between and within myofibrils. The results showed that the total size of gaps between and within myofibrils can be used as an indicator of meat tenderization during aging, but that ultrastructural alteration in electrically stimulated muscle had little relationship with meat tenderness.