• Applied Microscopy
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• 제18권2호
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• pp.205-217
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• 1988

An ultrastructural study of hepatocyte proliferation in the regenerating rat liver has been made by means of the partial hepatectomy. And electron microscopic histochemistry of hepatocyte in the regenerating rat liver is studied through alkaline phosphatase reaction. The results are as follows: 1. When the regeneration of rat liver is induced by the partial hepatectomy, the prominent ultrastructural characteristics of hepatocyte are changes of the distribution of chromatin in nucleus, increase of the number of mitochondria and decrease of the size of them, development of rough endoplasmic reticulum, and transient decrease of glycogen granules in cytoplasm. 2. Alkaline phosphatase reaction products are appeared in the nucleus or rough endoplasmic reticulum of hepatocyte during the initial regeneration of liver as 24, 48 and 72 hour groups after partial hepatectomy. And these positive reaction are mainly increased in cytoplasm and plasma membrane of hepatocytes during 1, 2 and 3 week groups after partial hepatectomy. As 4 weeks passed after partial hepatectomy, these positive reaction is located in the sinusoidal epithelial cells or erythrocytes. With above results, we concluded that alkaline phosphatase was synthesized in the rough endoplasmic reticulum bounded ribosomes of regenerating hepatocyte, was transported to the plasma membrane of them, and then was transported in blood by the way sinusoidel epithelial cells.

• Applied Microscopy
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• 제20권2호
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• pp.102-116
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• 1990

To investigate the ultrastructural features of rat back skin tumor induced by 7, 12-Dimethylbenz[a]anthracene(DMBA), morphological changes during carcinogenesis were undertaken by the light and the electron microscopes. On the light microscopic levels, dysplasia was observed at the 6th week of treatment with 0.5% DMBA, hyperplasia at the 8th week, and carcinoma in sitv or invasive carcinoma at the 12th week. In addition to those characteristics, papillomatosis was observed at the 18th week. Under the electron microscopy, intercellular spaces were enlarged in the early phase. Nucleolar enlargement, the increase of free ribosomes, the condensation of tonofibrils, and the irregular arrangement of desmosomes appeared at the 6th week of application. Thereafter, the degradation of desmosomes and the discontinuity of basal lamina were characterized. And then, epidermal cell processes were protruded toward the connective tissue at the site of discontinuity of basal lamina at the 12th week. At the 14th to 18th week, DMBA-induced fibrosarcomas or papillomas were observed.

• Applied Microscopy
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• 제26권3호
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• pp.267-275
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• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• 대한수의학회지
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• 제16권2호
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• pp.141-150
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• 1976

In order to know the morphological changes of liver in nitrate poisoning, the ultrastructural studies were carried out on the rabbit liver after potassium nitrate was administered orally at lethal dose, in single treatment, as acute case and at two different levels. 1.0 and 0.5g/kg of body weight daily for 43 and 60 days as chronic case, respectively, The results were summarized as followings: 1. In the hepatic cells of acute case, mitochondria were swollen, disappearance of cristae and variable in shape. Dilatation of rough endoplasmic reticulum and vacuoles containing degenerated cell organells were observed. Glyogen particles were decreased in number. Degenerated Kupffer cells were often seen in acute case. 2. In the hepatic cells of chronic case, there were increase of smooth endoplasmic reticulum, marked enlargement of rough endcplasmic reticulum, detachment of membrane bound ribosome and some rough endoplasmic reticulum changed into smooth endoplasmic reticulum. Secondary lysosome, abundant glycogen paricles and myelin-figure structures were also observed in the cytoplasm of the hepatic cells. The endothelial cells were proliferated in the area of the necrotic cells.

• Preventive Nutrition and Food Science
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• 제3권1호
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• pp.56-61
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• 1998

This study was conducted to investigate the effect of dietary supplementation of vitamin A on the membrane property and ultrastructure in ethanol-administered rat livers. Male Sprague-Dawley rats weighing of 130 ~150g were fed with experimental diets for 7 weeks. The diets contained different types of vitamin A which were $\beta$-carotene, retinyl acetate and retinoic acid. After feeding theexperimental diets for 7 weeks, a dose of 3.0g ethanol (30%, W/V)/kg B.W was injected to rats intraperitoneally. Control rats received 0.9% saline containing isocaloric sucrose instead of ethanol. Plasma membrane fluidity of liver decreased in rats fed with vitamin a -Deficient diet with ethanol as compared to that of control rats. Fluidity change of liver plasma membrane that ethanol had induced was influenced by dietary supplementation of vitamin A, but not influenced by the type of supplemented vitamin. A . The ultrastructural changed of hepatic mitrochondria were observed in some rats such as vitamin A-deficient rats with ethanol. Inadequate consumptionof vitamin A contributed to ultrastructural changes such as swelled mitochondria occurred by ethanol-induced hepatotoxicity. Although accurate mechanism involved in the plasma membrane-stabilizing effect of vitamin A is still unclear, dietary supplementation of vitamin A such as retinyl acetate is neede to modulate this change. The direct involvement of membrane property on the cell damage caused by ethanol treatment remains to be established.

• Applied Microscopy
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• 제28권2호
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• pp.207-213
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• 1998

To investigate ultrastructural changes on the adrenal cortex of the developmental rats, tissues were collected at 20 days of gestation, at birth, 7 days, 15 days and 30 days after birth and studied by transmission electron microscopy (TEM) the mitochondrial cristae of zona reticularis in the adrenal cortex of rats were a vesicular type and the vesicles were formed prior to 20 days of gestation. Also, the numbers of vesicles were $56.2{\pm}25.3$ in 20 days of gestation, $174.0{\pm}74.7$ at birth, $127.8{\pm}74.7$ in 7 days, $87.1{\pm}40.8$ in 15 days and $86.7{\pm}53.8$ in 30 days after birth, In this study, it was identified that the vesicles of mitochondrial cristae were formed by budding. The dense bodies were also observed in the nuclei of cortex cells from 20 days of gestation to 30 days after birth.

• 미생물학회지
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• 제41권4호
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• pp.312-315
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• 2005

먹물버섯의 하나인 Coprinellus congregatus에서는 자실체가 성숙된 후 곧 자가분해되어 먹물로 전환된다. 이 자가분해 과정과 관련된 가수분재 효소의 역할을 이해하기 위한 첫 단계로서, 자가분해과정과 연관된 미세구조의 변화를 전자현미경으로 조사하였다. 자실체의 성숙과정에서 자실층과 자실하층에 존재하는 모든 세포질은 새로운 포자의 형성을 위하여 포자로 이동되는 것으로 보인다. 조직 내의 세포질의 고갈과 포자의 완성은 조직 내의 세포벽의 분해를 야기하는 것으로 보이며, 자실층과 자실하층의 세포벽은 동시적으로 분해 되는 것으로 생각된다. 본 연구는 먹물버섯의 자가분해가 세포질의 분해가 아닌 세포벽의 분해과정에 의한 것임을 보여 주었으며, chitin 분해효소와 같은 가수분해 효소의 중요성을 제시하였다.

• Applied Microscopy
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• 제14권2호
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• pp.29-37
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• 1984

난소절제한 흰쥐에서 $17{\beta}$-estradiol과 progesterone을 장기간 주사햐여 자궁상피의 형태적 변화를 전자현미경으로 관찰하였다. 난소절제 후 자궁상피는 막성구조물과 지방구 기타의 구조물을 포함하는 vacuole의 출현이 특이적으로 나타났다. 상피는 낮은 입방형이며 세포 유리면에 소수의 짧은 microvilli를 볼 수 있었다. Estradiol투여시 상피는 높은 윈주형을 나타내며, 분비계는 비교적 잘 발달되고, 세포 유리면에 소수의 긴 microvilli도 관찰되었다. Progesterone 처리시의 상피는 세포 첨단부에 다수의 vacuole과 핵하부에 다수의 지방구의 집적이 관찰되었다. 이상의 결과로 보아 자궁상피는 형태학적 및 기능적인 상태에서 estrogen과 Progesterone 양자에 의해 변화를 받으며 이들 호르몬은 상피세포에 대해 독특한 영향을 나타낸다고 생각된다.

• The Plant Pathology Journal
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• 제17권6호
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• pp.315-324
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• 2001

Tobacco (Nicotiana tabacum cvs.Xanthi-nc and NC 82) plants infected with Tobacco mosaic virus (TMV) were examined ultrastructurally. Local lesions produced by TMV were sunken and withered. The plants were subjected to temperature shift (TS), a method to produce programmed cell death (PCD), by placing the infected plants initially at high temperature (35$^{\circ}C$) for 2 days and then shifting them to greenhouse temperature (22-27$^{\circ}C$). As a result, expanded lesions around the original necrotic lesions were produced. The expanded area initially had no symptoms, but it withered and became necrotic 15 h after TS. No ultrastructural changes related to PCD were noted at 0 h after TS in Xanthi-nc tobacco tissues as well as in healthy and susceptible tobacco tissues infected with TMV, At 6 h after TS, chloroplasts were convoluted and cytoplasm began to be depleted; however no necrotic cells were found. At 17 h after TS, ground cytoplasm of affected cells was completely depleted and chloroplasts were stacked together with bent cell wall or dispersed in the intracellular space. Necrotic cells were also observed, containing virus particles in the necrotic cytoplasm. There were initially two types of symptoms in the expanded lesions: chlorosis and non-chlorosis (green). Abundant TMV particles and X-bodies were only found in the chlorotic tissue areas. These results suggest that PCD by TMV infection may start with the wilting of cells and tissues before necrotic lesion formation.

• Applied Microscopy
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• 제26권3호
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• pp.253-266
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• 1996

To investigate the effects of mercuric chloride ($HgCl_2$) on the differentiation of the cerebral neuron of chick embryo 9 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 0.5 and 1.0mg-injected groups were undetectable, but in 2.0mg-injected group, the nuclear envelops were very irregular and mitochondria, were swelled and destroyed partly. The number of polypeptide bands separated by SDS-PAGE in the normal group were 37 bands. According to the in creased dose of mercuric chloride, contends of the bands were increased in 7 bands. The activities of dehydrogenases were declined by increasing the dose of mercuric chloride. Lactate dehydrogenase (LDH) activity failed to 78% in 1.0mg-injected group and greatly to 68% in 2.0 mg-injected group. Malate dehydrogenase (MDH) activity failed to 81% in 2.0 mg-injected group. On the other hand, succinate dehydrogenase (SDH) activity decreased to 80% in 1.0 mg-injected group and greatly to 63% in 2.0 mg-injected group. ATP content in 1.0 mg-injected group was increased slightly and in 2.0 mg-injected group was increased greatly.