• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.6
• /
• pp.329-335
• /
• 2006

This study was aimed to investigate the nitric oxide (NO)-induced cytotoxic mechanism in PC12 cells. Sodium nitroprusside (SNP), an NO donor, decreased the viability of PC12 cells in dose-and time-dependent manners. SNP enhanced the production of reactive oxygen species (ROS), and gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. Expression of Bax was not affected, whereas Bcl-2 was downregulated in SNP-treated PC12 cells. SNP augmented the release of cytochrome c from mitochondria into cytosol and enhanced caspase -8, -9, and -3 activities. SNP upregulated both Fas and Fas-L, which are known to be components of death receptor assembly. These results suggest that NO induces apoptosis of PC12 cells through both mitochondria-and death receptor-mediated pathways mediated by ROS and Bcl-2 family.

• The Korean Journal of Physiology and Pharmacology
• /
• v.22 no.3
• /
• pp.349-360
• /
• 2018

Autophagy has been studied as a therapeutic strategy for cardiovascular diseases. However, insufficient studies have been reported concerning the influence of vascular smooth muscle cells (VSMCs) through autophagy regulation. The aim of the present study was to determine the effects of VSMCs on the regulation of autophagy under in vitro conditions similar to vascular status of the equipped micro-tubule target agent-eluting stent and increased release of platelet-derived growth factor-BB (PDGF-BB). Cell viability and proliferation were measured using MTT and cell counting assays. Immunofluorescence using an $anti-{\alpha}-tubulin$ antibody was performed to determine microtubule dynamic formation. Cell apoptosis was measured by cleavage of caspase-3 using western blot analysis, and by nuclear fragmentation using a fluorescence assay. Autophagy activity was assessed by microtubule-associated protein light chain 3-II (LC-II) using western blot analysis. Levels of intracellular reactive oxygen species (ROS) were measured using $H_2DCFDA$. The proliferation and viability of VSMCs were inhibited by microtubule regulation. Additionally, microtubule-regulated and PDGF-BB-stimulated VSMCs increased the cleavage of caspase-3 more than only the microtubule-regulated condition, similar to that of LC3-II, implying autophagy. Inhibitory autophagy of microtubule-regulated and PDGF-BB-stimulated VSMCs resulted in low viability. However, enhancement of autophagy maintained survival through the reduction of ROS. These results suggest that the apoptosis of conditioned VSMCs is decreased by the blocking generation of ROS via the promotion of autophagy, and proliferation is also inhibited. Thus, promoting autophagy as a therapeutic target for vascular restenosis and atherosclerosis may be a good strategy.

• Journal of KIISE:Computer Systems and Theory
• /
• v.32 no.4
• /
• pp.177-185
• /
• 2005

NAND-type flash memory is becoming increasingly popular as a large data storage for mobile computing devices. Since flash memory is an order of magnitude more expensive than magnetic disks, data compression can be effectively used in managing flash memory based storage systems. However, compressed data management in NAND-type flash memory is challenging because it supports only page-based I/Os. For example, when the size of compressed data is smaller than the page size. internal fragmentation occurs and this degrades the effectiveness of compression seriously. In this paper, we present an efficient flash compression layer (FCL) for NAND-type flash memory which stores several small compressed pages into one physical page by using a write buffer Based on prototype implementation and simulation studies, we show that the proposed scheme offers the storage of flash memory more than $140\%$ of its original size and expands the write bandwidth significantly.

• Restorative Dentistry and Endodontics
• /
• v.29 no.3
• /
• pp.249-266
• /
• 2004

The purpose of this study was to determine whether pH and time has any influence on the degradation behavior of composite restoration by analyzing the leached monomers of dental composites qualitatively and quantitatively after storage in acetate buffer solution as a function of time using high performance liquid chromatography (HPLC) / mass spectrometer. Materials and Methods：Three commercial composite restorative resin materials (Z-250, Heliomolar and Aeliteflo) with different matrix structure and filler composition were studied. Thirty specimens (7mm $diameter{\times}2mm$ thick) of each material were prepared. The cured materials were stored in acetate buffer solution at different pH (4, 7) for 1, 7 and 45days. As a reference, samples of unpolymerized composite materials of each product were treated with methanol (10mg/ml). Identification of the various compounds was achieved by comparison of their mass spectra with those of reference compound, with literature data. and by their fragmentation patterns. Data were analysed statistically using ANOVA and Duncan's test. Results：1. Amounts of leached TEGDMA in Aeliteflo were significantly larger than those of UDMA in Z-250 and Heliomolar at experimental conditions of different storage time and pH variation (p<0.001). 2. As to comparison of the amounts of leached monomers per sorage time, amounts of leached TEGDMA in Aeliteflo and UDMA in Z-250 and Heliomolar were increased in the pH 4 solution more significantly than in the pH 7 solution after 1day, 7days and 45days, respectively (p<0.001). 3. In total amounts of all the leached monomers with storage times, the overall amounts of pH 4 extracts were larger than those of pH 7 extracts for all resin groups, but there was no significant difference (p>0.05).

• Mycobiology
• /
• v.44 no.4
• /
• pp.283-290
• /
• 2016

A double-stranded RNA (dsRNA) mycovirus was detected in malformed fruiting bodies of Pleurotus ostreatus strain ASI2792, one of bottle cultivated commercial strains of the edible oyster mushroom. The partial RNA-dependent RNA polymerase (RdRp) gene of the P. ostreatus ASI2792 mycovirus (PoV-ASI2792) was cloned, and a cDNA sequences alignment revealed that the sequence was identical to the RdRp gene of a known PoSV found in the P. ostreatus strain. To investigate the symptoms of PoV-ASI2792 infection by comparing the isogenic virus-free P. ostreatus strains with a virus-infected strain, isogenic virus-cured P. ostreatus strains were obtained by the mycelial fragmentation method for virus curing. The absence of virus was verified with gel electrophoresis after dsRNA-specific virus purification and Northern blot analysis using a partial RdRp cDNA of PoV-ASI2792. The growth rate and mycelial dry weight of virus-infected P. ostreatus strain with PoV-ASI2792 mycovirus were compared to those of three virus-free isogenic strains on 10 different media. The virus-cured strains showed distinctly higher mycelial growth rates and dry weights on all kinds of experimental culture media, with at least a 2.2-fold higher mycelial growth rate on mushroom complete media (MCM) and Hamada media, and a 2.7-fold higher mycelial dry weight on MCM and yeast-malt-glucose agar media than those of the virus-infected strain. These results suggest that the infection of PoV mycovirus has a deleterious effect on the vegetative growth of P. ostreatus.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.18 no.1
• /
• pp.94-110
• /
• 2005

The purpose of this research was to investigate the effects of Kamikwibitang water extract (KKT) on immobilization stress in C57BL/6J mice. KKT decreased the serum level of histamine and corticosterone increased by immobilization stress. In addition, KKT decreased the cell viability of thymocytes and enhanced the cell viability of splenocytes decreased by immobilization stress. Also, KKT decreased the viability of thymocytes and splenocytes in vitro. KKT decreased DNA fragmentation of splenocytes increased by immobilization stress. KKT decreased the population of thymic $CD4^+CD8^-$ cells increased by immobilization stress, and did not affect the population of $B220^+$ cells and the population of $Thy1^+$ cells changed by immobilization stress and enhanced the population of splenic $CD4^-CD8^+$ cells increased by immobilization stress. KKT enhanced the production of ${\gamma}-interferon$ and did not affect the production of interleukin-2 and interleukin-4 decreased by immobilization stress. Also, KKT decreased the phagocytic activity and the level of nitric oxide decreased by immobilization stress. These results indicate that KKT may be useful for the prevention and treatment of stress via suppression of serum histamine and corticosterone level and enhancement of specific-immune response.

• Nuclear Engineering and Technology
• /
• v.45 no.3
• /
• pp.323-334
• /
• 2013

During a hypothetical core-disruptive accident (CDA) in a sodium-cooled fast reactor (SFR), degraded core materials can form roughly conically-shaped debris beds over the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of the core material pool. However, coolant boiling may ultimately lead to leveling of the debris bed, which is crucial to the relocation of the molten core and heat-removal capability of the debris bed. To clarify the mechanisms underlying this self-leveling behavior, a large number of experiments were performed within a variety of conditions in recent years, under the constructive collaboration between the Japan Atomic Energy Agency (JAEA) and Kyushu University (Japan). The present contribution synthesizes and gives detailed comparative analyses of those experiments. Effects of various experimental parameters that may have potential influence on the leveling process, such as boiling mode, particle size, particle density, particle shape, bubbling rate, water depth and column geometry, were investigated, thus giving a large palette of favorable data for the better understanding of CDAs, and improved verifications of computer models developed in advanced fast reactor safety analysis codes.

• Radiation Oncology Journal
• /
• v.4 no.2
• /
• pp.107-113
• /
• 1986

Radiation myelitis is a rather rare, but irreversible fatal complication. Etiology, pathologic change, clinical symptoms and the method of diagnosis have been studied with animal experiments and human necropsies. In spite of massive studies, pathogenesis of post-irradiation myelitis and the level of tolerance dose still remain controversial. Thoracolumbar spine of 110 hybrid mice were irradiated with orthovoltage x-ray machine. Mild capillary congestion and axonal swelling were observed in 1,000 rad irradiated specimens. Focal necrosis in 3,500 rad specimens, fragmentation of neural tissue in 4,000 rad specimens were also observed. These results suggest that 5,000 rad is not a completely safe tolerable dose which have been accepted and we cannot exclude direct radiation damage to news tissue as the causative pathology of radiation myelitis in addition to blood vessel damage.

• The Journal of Internal Korean Medicine
• /
• v.27 no.3
• /
• pp.589-602
• /
• 2006

Hwangryunagyotang is supposed to have significant effects on some sorts of cardiovascular diseases like atherosclerosis. For this study. ACAT inhibitor was put in LDLR -/- mice to derive free cholesterol from it. This was to examine the effectiveness of Hwangryunnagyotang on its protecting and recovering function with endothelial cells damaged by free cholesterol through experimental. The results reported below. Hwangryunagyotang suppressed the crystallization of reactive oxygen species in macrophages and the numbers of free cholesterol crystal plate structured and reduced fragmentation of nucleus in ECV 304 cell strain by ACAT inhibitor significantly. Hwangryunagyotang also suppressed the necrosis of tissue in LDLR -/- mice' (treated with ACAT inhibitor) inflammatory portion which is adjacent to aortic root, proximal aorta and carotid artery by immunohistochemistry and fluorescence microscopy. On the whole, Hwangryunagyotang suppressed the necrosis of endothelial cells and especially it's effcet for the necrosis of para-myocardial tissues by free cholesterol. With this result, I suggest Hwangryunagyotang might have protective and recovery effects on atherosclerosis, so we need to carry on this study henceforth clinically and experimentally as well.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.17 no.4
• /
• pp.1037-1049
• /
• 2003

Numerous lines of evidence indicate that some of the neurotoxicity associated with Alzheimer's disease (AD) is due to proteolytic fragments of the amyloid precursor protein (APP). Most research has focused on the amyloid 6 (M). However, the possible role of other cleaved products of APP is less clear. Lately It has been reported that a recombinant carboxy-terminal 105 amino acid fragment (CT105) of APP induced strong nonselective inward currents in Xenopus oocyte. In a brain with Alzheimer's disease (AD), to investigate the roles of carboxyl-terminal fragment (CT105) of amyloid precursor protein (APP) in apoptosis processes possibly linked to neurodegeneration associated with AD, we examined the effects of the CT of APP with 105 amino acid residues (CT105) on the alteration of apoptosis triggers in neubroblastoma cells. We have investigated whether Radix Polygalae and Rhizoma Acori Graminei mixture extract (RP+RAG) inhibits CT105-induced apoptosis of neuroblastoma cells. We found that RP+RAG inhibits CT105-induced apoptosis in SK-N-SH cells. Treatment of the cells with RP+RAG inhibited CT105-induced DNA fragmentation and Tunel assay of nuclear chromatin and inhibited the caspase-3 expression in SK-N-SH cells. As the result of this study, In RP+RAG group, the apoptosis in the nervous system is inhibited, the repair against the degerneration of neuroblastoma cells by CT105 expression is promoted. These results indicate that RP+RAG possess strong inhibitory effect of apoptosis in the nervous system and repair effect against the degeneration of neuroblastoma cells by CT105 expression