• Applied Microscopy
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• v.24 no.3
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• pp.55-66
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• 1994

This study was carried out to investigate the histological changes of sperm cells in testis, obtained from 100 of 3-year-old male rainbow trout (Oncorhynchus mykiss) collected and analysed from March in 1992 to February in 1993. Especially, the ultrastructural changes of spermatogonia, primary and secondary spermatocytes, spermatids, and spermatozoa were examined to describe the reproductive cycles of this species. The results obtained in this study were as follows: The ultrastructures of the gonadotrophs largely parallel the cyclical changes in the testes. Each nest of cells belongs to one spermatogenetic stage, although nests at different stages can be found within the one lobule. At first keterochromatin is dispersed and then is condensed. In mature gamete, the nucleus is dense and homogeneous. The nuclear membrane appeared at the beginning of differentiation. In spermatogonia, Sertoli cells are located at the periphery of their cytoplasm. In the primary spermatocytes, the small mitochondria are abundant over the outer cytoplasm. During cell differentiation, the cytoplasm decreases and the nucleus increases. In spermatids, the protein masses moved towards the posterior part of the nucleus. In late spermatids, the two large mitochondria are located over the cytoplasm. In spermatozoa, two spheroidal mitochondria (about 145nm 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 two centrioles are quite separate and the central pair and sheath complex of the flagellum is inserted into the base of the distal centriole.

• Applied Microscopy
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• v.20 no.1
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• pp.51-64
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• 1990

This experiment was performed to study the morphological changes of the goblet cells in the rabbit duodenal mucosa after common bile duct ligation. Healthy adult rabbits weighting about 2kg body weight were divided to normal and bile duct ligated groups. Common bile duct ligation was performed under ether anesthesia. Experimental animals were sacrificed on the 1st, 3rd, 5th, 7th and 14th day after the operation. Mucosal specimens from the upper part of duodenum were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde, followed by 1% osmium tetroxide, embedded in araldite mixture, cut with LKB-V ultratome, stained with uranyl acetate - lead citrate, and observed with JEM 100 CX II electron microscope. Observed results were as follow : 1. In the early stages(1st-5th day) of the experiments, the goblet cells showed apocrine and merocrine secretion. But those of the late stage(7th and 14th day) groups showed exocytotic merocrine secretion. 2. In the late stage of the experiments, there found than increase of newly formed goblet cells that contain electron lucent cytoplasms. 3. In the goblet cells of normal rabbit, mucous granules with higher or lower electron densities are found together in the cytoplasm, and electron lucent mucous granules occasionally fused together. But in the early stage of the common bile duct ligation, goblet cells contained granules of higher electron densities. 4. Considering the above findings, common bile duct ligation probably initiates the hypersecretion of mucous granules of goblet cells in the early stage, and may facilitate the differentiation of goblet cells in the later stage.

• Applied Microscopy
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• v.24 no.1
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• pp.11-27
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• 1994

The morphological development of the carotid body was studied by electron microscope in human fetuses from 40mm to 260mm crown rump length (10-30 weeks of gestational age). At 40mm fetus, the carotid body was composed of cluster of primitive glomus cells, primitive supporting cells, unmyelinated nerve fibers, and blood capillaries. In connective tissue between internal and external carotid arteries adjacent to the superior cervical sympathetic ganglion, two types of glomus cells through all prenatal period were found. Dark cells contained a dense cytoplasm with conspicuous large dense-cored granules, whereas light cells had a less dense cytoplasm with dense-cored granules. The light cells contained dense-cored granules that were smaller and less abundant than those in the dark cells. The primitive supporting cells appeared star-shaped with attenuated cytoplasmic extensions intervening between the adjacent glomus cells. Synaptic contact between the axon terminals and soma of the glomus cells were first observed at 40mm fetus. In 80-100mm fetus, the carotid body contained tightly packed collection of glomus cells and supporting cells which surrounded the abundant thin-walled blood vessels. Intercellular junctions between the glomus cells and adjacent cells were commonly seen. Nerve endings on the glomus cells have the form of small boutons and the other from of large calyces. During the second half of the fetal period, the glomus cells were completely enveloped by supporting cells and nerve terminals. At 260mm, the morphological features of carotid body were similar to those of human adult. The result of this study demonstrates that there are differences between the carotid body and aorticopulmonary bodies, especially with respect to their synaptic complexes, abundant blood capillaries, and two glomus cell types.

• The Journal of the Korean Society for Microbiology
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• v.11 no.1
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• pp.1-11
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• 1976

An electron microscopic study has been made of the effects of change of cell structure of Escherichia coli treated with several disinfectants. The alterations observed as follows: 1. Nucleoid, cytoplasm which contain ribosomes and cell wall appeared to be composed of a parallel triple. layered membrane can observed in control Escherichia coli. 2. The nuclear material was no longer demonstrable in its normal sites. The cytoplasm lost its granularity, became homogeneous and disruption of cell wall were observed by the treatment with 70% ethyl alcohol and 3% $H_2O_2$. 3. Aggregation of ribosomes and condensation of nuclear material were also observed by the treatment of 5% lysol solution and 1% dodecyl-diamino-ethyl-glycin-hydrochloride. 4. In autoclaved group, the each layer of cell wall was separated and destroyed in some sites where cytoplasm was extracted.

• Applied Microscopy
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• v.31 no.4
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• pp.385-392
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• 2001

The purpose of this study was to evaluate the histological toxicity of chitosanoligosaccharide on the rat. A healthy male of Wistar rat that weighted $250{\pm}350g$ was used for experiment The experimental group was divided into five groups. Group 1 was control group which treated with general food Group 2 was $F_1$ generation which was born by mating of 0.1% (1 mg/ml) chitosanoligosaccharide was supplied by feeding ad libitum for 30 days. Group 3 was $F_2$ generation which was born by mating $F_1$ generation. Group 4 was treated with 90 days of 0.1% (1 mg/ml) chitosan oligosaccharide. Group 5 was treated with 365 days of 0.1% (1 mg/ml) chitosanoligo saccharide. All experimental groups were used to 10 rat. The results were as follow: The RER dilation was observed Group 4. However, there were no significantly changes of ultrastructures in the other groups compared to the control. It was concluded that chitosanoligosaccharide can be used for nontoxic natural material.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.141-165
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• 1997

Radiation-impaired wound healing in animal experiments was believed to be an another logical experimental model to understand the wound healing mechanism in patients. The purpose of this study was to reveal the block point which would result in impaired healing. Twenty four rats(Sprague-Dawley strains) were divided into two groups according to the time interval between irradiation and wounding. Group I, observing the healing effect on the 1st day and Group II are the healing effects on the 7th days after irradiation to the wound of the rat tongue. Experimental animals were sacrificed 3, 6, 12, and 24 hours after wounding. The specimens were examined by the light microscope and transmission electron microscope. The following results were obtained 1. Fibroblasts in both groups showed degenerative changes which were dilated mitochondria and rER, reduced microorganelle, vacuoles and little cytoplasmic process. 2. Average length between bands and Quantity of the newly produced collagen fibers around fibroblasts remained unchanged against control group. 3. The severity of degenerative change of the fibroblast and impairment of wound healing including shortening of the thickness of collagen fibers were more severe in the group II than in the group I.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.1-16
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• 1991

In order to see the possible effect of the functional load-bearing after osseointegration of the titanium root form implant in dog a histologic study was conducted. One side of lower jaw was surgically prepared edentulousness and titanium implants were inserted. Some implants were functionally loaded through fixed detachable prosthesis and some are isolated and unloaded. The dog was sacrificed four months later and bone sections with implants were processed for histologic evaluation and the results were as follows ; (1) The bone to implant interface after four months of load bearing presented no mobility and no marginal bone loss radiographically and histologically. (2) The interface zone between compact bone and implant revealed a direct bone to implant contact and in some areas marrow tissue contacts were examined at the light microscopic level. (3) At the ultrastructural level the interface of surrounding compact bone matrix and implant, three types of superficial layers were found ; one with moderate electron dense amorphous granular substance layer, other with high electron dense fine granular substance layer, and another type of amorphous granular substance covered with high electron dense line of minute granules. (4) The osteoblasts in the marrow tissue neighboring implants and osteocytes in compact bone showed typical normal characteristics and in the marrow tissues some of lymphocytes and mast cells were observed. (5) The abscence of abnormal tissue reactions at a cellular level indicates a high degree of biocompatibility for the experimental titanium implant and basically no difference was found between functionally loaded and unloaded implants.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.415-423
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• 2005

Distraction osteogenesis (DO) is frequently used technique in reconstruction of bony defects resulted from tumor resection, congenital deformity, and trauma in the maxillofacial region. Although the histologic and ultrastructural changes associated with distraction osteogenesis have been extensively described, the exact changing of the surrounding tissues, such as nerve tissues, were still unclear. This study observed the histological changes and the expression of nerve growth factor (NGF) in the inferior alveolar nerve (IAN) after distraction osteogenesis. Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in eight mongrel dogs. Two animals were sacrificed at 7, 14, 28 and 56 days after completion of distraction, respectively. The distracted IAN and contralateral control nerve were harvested and processed for histological and innunohistochemical examinations. The signs of acute nerve injuries, such as demyelination and partial discontinuation of nerver fiber, were observed in the distracted IAN on 7 and 14 days after distraction. The initial remyelination and regeneration of distracted IAN were showed at 14 days after completion of distraction. At 56 days later, the histologic features of distracted IAN was similar to those of the normal control IAN. The expression of NGF was significantly increased in most distracted nerve tissues on 7, 14 and 28 days after distraction. On 56 days after distraction, the expression of NGF returned to the normal level. This study suggested that the acute IAN injury caused by mandibular distraction were mostly recovered during consolidation period. The NGF was seemed to be induced from Schwann cell and damaged nerve tissues, and it may have important roles in the initial healing of damaged nerves.

• Applied Microscopy
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• v.39 no.1
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• pp.49-56
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• 2009

In this study, we investigated tensile properties and ultrastructural changes of straight permed hair using the rheometer and the scanning electron microscopy. First, we compared the morphological characteristic between the virgin hair and the straight permed hair after testing tensile strength. Cuticle cells were heavily lifted off in straight permed hair than in the virgin hair. Cuticle cells were separated by the destruction of intercellular membrane complex and no destruction or damage were found in cytoplasm. In the comparative test for tensile characteristic between the virgin hair and the straight permed hair, tensile distance of the straight permed hair was decreased by 24.5% or 3.05 mm than the virgin hair. The tensile strength was decreased by 34.63% or $5.62\;g/cm^2$ and the maximum stress by 34.59% or 56.12 g. As a result, the tensile property dropped to the lowest level with the straight permed hair than with the bleached hair or the permanent dyed hair of previous studies.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.129-138
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• 1999

This study was carried out with two types of silkworm, Bombyx mori, adults having different life span: long life span (adult living for more than fifteen days; LLS), and short life span (adult living less for than five days; SLS). The fine structures of fat body cells in the young and the senescent males and females were compared in an attempt to elucidate the aging physiology of the silkworm adult. In SLS, there were many rough endoplasmic reticula (RER) and glycogen granules in the female cytoplasm, whereas the smooth endoplasmic reticula (SER) were observed in the male cytoplasm. Also in SLS, the mitochondria were swollen and had many poor osmiophillic inclusions (fatty degeneration) at three days after emergence. In LLS, compared to SLS, comparatively normal mitochondria and nuclear membrane were observed in even five day old female. In fifteen day old LLS female, however most of cell membranes were disappeared and mitochondria were abnormally expanded. Many fat granules were observed in the cytoplasm of ten day old male (LLS) which died with full autophagic vacuole (AV) collapsed at fifteen days. Therefore, it is suggested that SLS type is recommended for the study of aging tissue, because it is easier to monitor the changes in tissue structure.