• BMB Reports
• /
• v.33 no.6
• /
• pp.448-453
• /
• 2000

In yeast the key gluconeogenic enzyme, fructose-1,6-bisphosphatase (FBPase), is selectively targeted from the cytosol to the lysosome (vacuole) for degradation when glucose starved cells are replenished with glucose. The pathway for glucose induced FBPase degradation is unknown. To identify the receptor-mediated degradation pathway of FBPase, we investigated the presence of the FBPase receptor on the vacuolar membrane by cell fractionation experiments and binding assay using vid mutant (vacuolar import and degradation), which is defective in the glucose-induced degradation of FBPase. FBPase sedimented in the pellets from vid24-1 mutant after centrifugation at $15,000{\times}g$ for 15 min, suggesting that FBPase is associated with subcellular structures. Cell fractionation experiments revealed that FBPase is preferentially associated with the vacuole, but not with other organelles in vid24-1. FBPase enriched fractions that cofractionated with the vacuole were sensitive to proteinase K digestion, indicating that FBPase is peripherally associated with the vacuole. We developed an assay for the binding of FBPase to the vacuole. The assay revealed that FBPase bound to the vacuole with a Kd of $2.3{\times}10^6M$. The binding was saturable and specific. These results suggest that a receptor for FBPase degradation exists on the vacuolar membrane. It implies the existence of the receptor-mediated degradation pathway of FBPase by the lysosome.

• Korean Journal of Veterinary Research
• /
• v.22 no.2
• /
• pp.187-195
• /
• 1982

This paper dealt with the light microscopical and electron microscopical findings on the morphological changes of the liver of Korean native goat injected with toxin (culture filtrate) of Clostridium perfringens which was isolated from Korean native cattle died of acute Clostridium perfringens enterotoxemia. The results observed are summarized as follows. In the microscopical findings, hyperemia and minute hemorrhage of the liver parenchyma, dilatation of hepatic central vein and centrilobular necrosis of liver, cloudy swelling and hydropic degeneration of hepatic cells, and appearance of light eosinophilic granular bodies in the vacuoles were recognized. In the electron microscopical findings, appearance of pinocytotic vesicle (coated vesicle), fusion of these vesicles, formation of vacuole and accumulation of minute granular proteinous materials in the vacuole were observed in the hepatic cells. Decreased number of glycogen granules, swelling and destruction of mitochondria, proliferation of smooth-surfaced endoplasmic reticulum, enlargement of rough-surfaced endoplasmic reticulum, dispersal of thready agranular membranous structure and appearance of secondary lysosome were recognized in the hepatic cell cytoplasm.

• Applied Microscopy
• /
• v.24 no.1
• /
• pp.41-58
• /
• 1994

The present studies were designed to determine the feasibility of using the rat tracheal epithelium as models for induction of aging. The ultrastructural and cytochemical changes of tracheal epithelium were investigated in rats at ages of five, twelve and twenty four months. Some major changes in the tracheal epithelium with advancing age were observed by electron microscopy. The results were summarized as fellow: 1. With the advance of age, lysosome, vacuole and multivesicular bodies were increased in number and numerous myelinoid bodies were observed in cytoplasm of ciliated cells. 2. In goblet cell, serous cell and brush cell lysosome and myelinoid bodies were increased in number with the advance of age, and an myelinoid bodies was often found within the secretory granule. 3. Cytochemical studies showed that acid phosphatase activities was observed in multivesicular bodies and lysosome, strong activities with the advance of age. And alkaline phosphatase activity are observed in microvilli, granule and lateral membrane of secretory granule cells, and strong activities with age. Consequently suggest that with the advance of age, tracheal epithelium show ultrastructural and cytochemical alteration of some kind of cell organelles in all kind of cell.

• BMB Reports
• /
• v.42 no.2
• /
• pp.65-71
• /
• 2009

Autophagy, which is a process of self eating, has gained interest in the past decade due to its both beneficial and controversial roles in various biological phenomena. The discovery of autophagy genes (ATG) in yeast has led to focused research designed to elucidate the mechanism and regulation of this process. The role of autophagy in a variety of biological phenomena, including human disease, is still the subject of debate. However, recent findings suggest that autophagy is a highly regulated process with both beneficial and negative effects. Indeed, studies conducted using various model organisms have demonstrated that increased autophagy leads to an extended lifespan. Despite these findings, it is still unknown if all pathways leading to extended lifespan converge at the process of autophagy or not. Here, an overview of modern developments related to the process of autophagy, its regulation and the molecular machinery involved is presented. In addition, this review focuses on one of the beneficial aspects of autophagy, its role in lifespan regulation.

• Applied Microscopy
• /
• v.26 no.4
• /
• pp.465-477
• /
• 1996

The influence of dehydrocholic acid, cholesterol and phosphstidylcholie to the fine structure of vacuolar apparatus was investigated to better understand the mechanism of intracellular transport of bile constituents in the hepatocytes of rats. The cis Golgi cisterns faced toward the bile canaliculi both in normal and experimental groups. In the hepatocytes from the rats of experimental groups, the primary organic solutes in bile influence the Gogi apparatus, ER and lysosome in the way of increase, cisternal dilation or budding to form the vacuoles. In the dehydrocholic acid group, the cis Golgi cisterns appeared to be sacculated and showed buds, which were probably separated to be vacuoles. Some of the vacuoles appeared to be fused to the bile canaliculi. In the cholesterol and phosphatidylcholine groups, the Golgi cisterns appeared to be dilated and lysosomes were increased in the vicinity of bile canaliculi. The cis Golgi cisterns showing linear saccular fashions were occasonally observed. The increase of lysosomes were more predominant in the cholesterol group. The evidence suggests that dehydrocholic acid is mainly transported through the ER and cis Golgi cisterns, and cholesterol and phosphatidylcholine are mainly transported through the ER and lysosomes via the trans Golgi cisterns, but the cholesterols are frequently transported via the lysosomes.

• Applied Microscopy
• /
• v.3 no.1
• /
• pp.1-16
• /
• 1973

A combined cytochemical and electron microscopic study was carried out for the demonstration of acid phosphatase activities in trophozoites of E. histolytica. and E. gingivalis. E. histolytica(YS-27) strain was isolated from liver abscess of 72-year-old man in September 1969, and E. gingivalis (YS-215) strain was collected from gingival crevice of 41-year-old man in January 1972. The amoeba strains were maintained by subculture on diphasic medium, and used throughout the study. The results are summarized as follows; 1. In E. histolytica, the reaction products were distributed evenly over the entire surface of plasma membrane, whereas E. gingivalis showed no activity of acid phosphatase on the plasma membrane, except in the portion of the uroid-like structure. 2. In the cytoplasm, various reaction precipitates were observed in vacuoles of both amoebae; vacuole limiting membrane, vacuole membrane and its contents and lysosome-like structure. Strong enzyme active contents but membrane reaction negative vacuoles were conspicuous in E. gingivalis. Endoplasmic reticulum showed a moderate activity. 3. Granule-like acid phosphatase reaction product was demonstrated in the nucleoplasm of E. gingivalis, but it was negative in E. histolytica.

• Applied Microscopy
• /
• v.12 no.2
• /
• pp.35-44
• /
• 1982

The fat bodies of cabbage worm (Pieris rapae) and silk worm (Bomyx mori) during metamorphosis was comparatively studied by electron microscope. 1. Cell oranelles: Golgi apparatus were not observed in both species. It is observed that RER of cabbage worms initiate to degenerate in prepupa stage with complete degeneration at adult stage, while that of silk worms shows similar degenerative pattern. However, mitochondria of cabbage worms are transformed into autophagic vacuole from prepupa stage until adult stage whereas those of silk worm shows a decrease in number in prepupa stage but maintains a certain level until adult stage. 2. Storage substance in cell: Lipid droplets in cabbage worms were observed to increase in numbers during larval stage but afterward decrease in number with an enlargement in size. However immediately after their pupal stage, they almost disappear. On the contrary lipid droplets in silk worms show rather increase in number until adult stage. Protein storage granules in bothspecies were arised from autophagic vacuoles(lysosome) . Fat cells of cabbage worm in adult stage turn out to be residual bodies which last until final stage, but those of silk worm rapidly decrease. Glycogen particles in both species reach maximum at last larval instar and thee gradually decrease thereafter. 3. Fat body sheath: The average width of fat body sheath was measured to be $0.2{\mu}m$ and $0.6{\mu}m$ and surface of fat cells adjacent to fat body sheath in silk worm is heavily infolded.

• The Journal of the Korea Contents Association
• /
• v.10 no.7
• /
• pp.297-304
• /
• 2010

As Small Intestine Absorptive Epithelium Cells are surrounded by mucus polysaccharide and lymphocytes and mitochondria, they are sensitive to radiation energy. Damaged cells lead to a deficiency of nutrients and the imbalance of electrolyte metabolism, which in turn can becomes a major cause of an intestine tract death. This research observed ultra structures after injecting propolis into the abdominal cavity in order to reveal the radiation damage mechanism and radioprotection effect of intestine absorptive epithelium cells. The result of this research's observation found that stenosis occurred in the small intestine in some tissues 20 days after 5Gy irradiation, their surface turned black, and their elasticity dropped. Through observation with an optical microscope, it was found that the size of the goblet cells decreased, while the paneth granulate cells atrophied and were vacuolated. Observation with an transmission electron microscope(TEM) revealed that while microvill and lysosome were normally observed in jejunum tissues, mitochondria membrane was damaged and uneven surfaces were formed on lymphocytes. The membrane of absorptive epithelium cells hypertrophied in tissues of the ileum, and vacuole was observed. However, the observation after injecting propolis into the abdominal cavity found that mitochondria damage dropped dramatically, and radioprotection effects were to some extent confirmed, considering that glycocalyx of villi was clear, and M cells could be observed.

• The Korean Journal of Malacology
• /
• v.27 no.3
• /
• pp.213-221
• /
• 2011

Equilateral venus, Gomphina veneriformis exposed to tribultyltin chloride (TBTCl) for 36 weeks was showed ultrastructural changes of the mantle. The fine mantle had 4-folds and its epidermal layer consisted of simple columnar epithelial cells and ciliated cells and secretory cells. Inner and outer epidermal layer covered connective tissue. The mantle exposed to TBTCl at 12 weeks was decreased cilia in the inner epidermal layer, and observed extension of the hemolymph sinus and destruction of the septum. At 20 weeks, it revealed vacuole formation and pycnosis in the cytoplasm, and scattered muscular fiber. After 28 weeks of exposure, the mantle revealed partially degenerative changes in the epidermal layer. In the ciliated cells, basal body was isolated from the cilia and rootlet complex and basal foot were scattered. The sarcolemma had debris fiber. At 36 weeks, it observed degenerative cells that it revealed disappearance of the cilia, atrophic nucleus, poorly membrane and destruction of the cresternae in the mitochondria, and increasing heterophagosome. The outer epithelial cell had necrotic nuclus, numeous lysosome and disappearance of the microvilli. Therefore, results of this study suggested that chronical TBTCl exposure in the Gomphina veneriformis induced the disorders of shell growth and physiological function with histopathological changes of the mantle.

• The Journal of Korean Academy of Prosthodontics
• /
• v.28 no.2
• /
• pp.1-28
• /
• 1990

The severe atrophic edentulism with poor neuromuscular control militates against successful conventional denture therapy. To such situation, a prescribing of dental implant treatment has been considered with some probability. Implant materials used as a trial for dental implants includes metals, plastic polymers and ceramics. The purpose of this study was to observe histologic response in osseointegration process at titanium implant-tissue interface based on biocompatibility at specific period of sequential natures which were divided into a half month, one, month, two months, three months and immediate as a base line. In this study, unilateral lower left premolar and molar teeth were extraced in three dogs. After allowing to heal for 6 months, three kinds of osseointegrated implant, $Br{\aa}nemark$, Corevent and kimplant(a prototype of SNU implant study)were inserted in each dog respectively according to the above sequence from front to back. The specimens were taken from those dogs at the same time since implant were inserted quite reverse order of the specified periods, and decalcified and processed for histologic examination for the light microscopy and the electron microscopy. The microscopic histologic findings at the interface between titanium implants and tissue were interpretated as follows : A. Light microscopic findings : a. Immediate : Implant were surrounded by compact bone and spongy bone. Microcrak was observed in the superficial bone tissue. Osteocytes were disappeared and bone lacunae were observed as a vacant space in some parts. In the contacting with the spongy bone, bone trabeculae and bone marrow were in contact with the implant. b. A half Month : Osteoblasts exist as a monolayer in th inner bone trabeculae and do bone additiocn. Osteoblasts&inflammatory cells were observed in some parts. c. One Month : The presence of osteoclasts decreased. Osteoblasts did active bone fromation, and bone marrow was in contact with the implant in the many places. d. Two Months : Bone formation was advanced in comparison with the b and c. The presence of osteoclsts was not observed. e. Three Months : The superficial bone tissue contacted with the implants was entirely composed by the compact bone. B. Electron microscopic findings : a. A half month and one month group : In the parts of the active bone formation, osteoblasts with the well developed endoplasmic reticulum and Golgi apparatus were arranged in the monolayer. In the parts of the bone resorption, ruffled border was well developed and many osteoclasts with the well-developed golgi apparatus, mitochondria, vacuole, vesicle and lysosome were existed. b. Three months group : No osteoblasts were observed in the superficial bone tissue. Bone matrix with collaen fiber was observed. c. No significant dirrerence in the histologic findings was observed in $Br{\aa}nemark$, Core-vent and kimplant.