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김진호,정영헌,조기철,이협희,오광중 부산대학교 환경문제연구소 1998 環境硏究報 Vol.16 No.-
Pyrolysis system will plat a big role on the resource recovery of wastes without secondary pollution problems comparing usual incineration system. Pyrolysis experiments of municipal solid wastes was conducted and the results are as follows. 1) From tile compression test before the pyrolysis, moisture removal was observed from 70% compression and the variation of the removed moisture amount was detected until 80% compression. Over the 80% compression, there was no change. 2) Non-isothermal pyrolysis reaction constant was found out through the experiment. When the increasing rate of temperature varied from 20 to 40 K/min, the activation energy of cellulose and plastic were 100~160 KJ/mol and 192~239KJ/mo1, respectively. The order of reaction was on the range of 1.2~1.8. As the increasing rate of temperature increased, the activation energy was decreased.
<i>Idh2</i> deficiency accelerates renal dysfunction in aged mice
Lee, Su Jeong,Cha, Hanvit,Lee, Seoyoon,Kim, Hyunjin,Ku, Hyeong Jun,Kim, Sung Hwan,Park, Jung Hyun,Lee, Jin Hyup,Park, Kwon Moo,Park, Jeen-Woo Academic Press 2017 Biochemical and biophysical research communication Vol. No.
<P><B>Abstract</B></P> <P>The free radical or oxidative stress theory of aging postulates that senescence is due to an accumulation of cellular oxidative damage, caused largely by reactive oxygen species (ROS) that are produced as by-products of normal metabolic processes in mitochondria. The oxidative stress may arise as a result of either increased ROS production or decreased ability to detoxify ROS. The availability of the mitochondrial NADPH pool is critical for the maintenance of the mitochondrial antioxidant system. The major enzyme responsible for generating mitochondrial NADPH is mitochondrial NADP<SUP>+</SUP>-dependent isocitrate dehydrogenase (IDH2). Depletion of IDH2 in mice (<I>idh2</I> <SUP>-<I>/</I>-</SUP>) shortens life span and accelerates the degeneration of multiple age-sensitive traits, such as hair grayness, skin pathology, and eye pathology. Among the various internal organs tested in this study, IDH2 depletion-induced acceleration of senescence was uniquely observed in the kidney. Renal function and structure were greatly deteriorated in 24-month-old <I>idh2</I> <SUP> <I>-/</I>-</SUP> mice compared with wild-type. In addition, disruption of redox status, which promotes oxidative damage and apoptosis, was more pronounced in <I>idh2</I> <SUP> <I>-/</I>-</SUP> mice. These data support a significant role for increased oxidative stress as a result of compromised mitochondrial antioxidant defenses in modulating life span in mice, and thus support the oxidative stress theory of aging.</P> <P><B>Highlights</B></P> <P> <UL> <LI> IDH2 is a major enzyme to maintain mitochondrial redox status. </LI> <LI> Depletion of IDH2 in mice shortens life span and accelerates aging. </LI> <LI> Renal function was greatly deteriorated in 24-month-old <I>idh2</I> <SUP>-<I>/</I>-</SUP> mice. </LI> </UL> </P>
Lee, Jung Hoon,Kim, Nayoung,Chung, Jae Il,Kang, Kyung Phil,Lee, Sang Hyup,Park, Young Soo,Hwang, Jin-Hyeok,Kim, Jin-Wook,Jeong, Sook-Hyang,Lee, Dong Ho,Jung, Hyun Chae,Song, In Sung Wiley (Blackwell Publishing) 2008 HELICOBACTER -CAMBRIDGE USA- Vol.13 No.4
<P>BACKGROUND: Serology is widely used for epidemiologic research of Helicobacter pylori. However, there is limited information on the long-term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long-term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea. METHODS: Among 247 patients, who were enrolled during 2003-07, 185 patients with invasive H. pylori test positive received proton pump inhibitor-based triple therapy, and follow-up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication. RESULTS: The initial H. pylori IgG optical density (OD(450 nm)), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests. CONCLUSION: The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori, in Korea, was found to be very low, 2.94% per year.</P>
Lee, Jae Hyup,Baek, Hae-Ri,Lee, Kyung Mee,Zheng, Guang Bin,Shin, Sung Joon,Jin, Yuan Zhe Harwood Academic Publishers 2015 Growth factors Vol.33 No.3
<P>This study evaluated the effect of the combined treatment of intravenous zoledronic acid (ZA, 0.08?mg/kg) and rhBMP-2 (5??g) on osteogenesis in a calvarial defect model of ovariectomized SD rats. New bone formation was evaluated 4 or 8 weeks after calvarial defect implantation using micro-CT and histology. Micro-CT results revealed that the rhBMP-2 group showed significantly higher calvarial defect coverage ratio compared with the ZA?+?rhBMP-2 group at 4 weeks. In addition, bone formation indices were significantly lower in ZA?+?rhBMP-2 group when compared with the rhBMP-2 group after 4 weeks, which indicates a negative effect of ZA on the initial bone formation and the bone quality. At 8 weeks, the negative effect induced by ZA treatment was alleviated as time passed. Histological examination showed similar results to the micro-CT measurements. In conclusion, although ZA treatment lowered the new bone formation induced by rhBMP-2 initially, as time passed, the negative effect was decreased.</P>
The effect of &agr;-phenyl- N-t -butylnitrone on ionizing radiation-induced apoptosis in U937 cells
Lee, Jin Hyup,Park, Jeen-Woo Taylor Francis 2005 Free radical research Vol.39 No.12
<P>Ionizing radiation induces the production of reactive oxygen species (ROS), which play an important causative role in apoptotic cell death. &agr;-Phenyl- N-t -butylnitrone (PBN) is one of the most widely used spin-trapping compounds for investigating the existence of free radicals in biological systems. We investigated the effects of PBN on ionizing radiation-induced apoptosis in U937 cells. Upon exposure to 2 Gy of γ-irradiation, there was a distinct difference between the control cells and the cells pre-treated with 2 mM PBN for 2 h in regard to apoptotic parameters, cellular redox status, mitochondria function and oxidative damage to cells. PBN effectively suppressed morphological evidence of apoptosis and DNA fragmentation in U937 cells exposed to ionizing radiation. The [GSSG]/[GSH+GSSG] ratio and the generation of intracellular ROS were higher and the [NADPH]/[NADP + +NADPH] ratio was lower in control cells compared to PBN-treated cells. The ionizing radiation-induced mitochondrial damage reflected by the altered mitochondrial permeability transition, the increase in the accumulation of ROS, and the reduction of ATP production were significantly higher in control cells compared to PBN-treated cells. PBN pre-treated cells showed significant inhibition of apoptotic features such as activation of caspase-3, up-regulation of Bax and p53, and down-regulation of Bcl-2 compared to control cells upon exposure to ionizing radiation. This study indicates that PBN may play an important role in regulating the apoptosis induced by ionizing radiation presumably through scavenging of ROS.</P>