• Title/Summary/Keyword: Activity/Attenuation

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The Evaluation of Reconstruction Method Using Attenuation Correction Position Shifting in 3D PET/CT (PET/CT 3D 영상에서 감쇠보정 위치 변화 방법을 이용한 영상 재구성법의 평가)

  • Hong, Gun-Chul;Park, Sun-Myung;Jung, Eun-Kyung;Choi, Choon-Ki;Seok, Jae-Dong
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.2
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    • pp.172-176
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    • 2010
  • Purpose: The patients' moves occurred at PET/CT scan will cause the decline of correctness in results by resulting in inconsistency of Attenuation Correction (AC) and effecting on quantitative evaluation. This study has evaluated the utility of reconstruction method using AC position changing method when having inconsistency of AC depending on the position change of emission scan after transmission scan in obtaining PET/CT 3D image. Materials and Methods: We created 1 mL syringe injection space up to ${\pm}2$, 6, 10 cm toward x and y axis based on central point of polystyrene ($20{\times}20110$ cm) into GE Discovery STE16 equipment. After projection of syringe with $^{18}F$-FDG 5 kBq/mL, made an emission by changing the position and obtained the image by using AC depending on the position change. Reconstruction method is an iteration reconstruction method and is applied two times of iteration and 20 of subset, and for every emission data, decay correction depending on time pass is applied. Also, after setting ROI to the position of syringe, compared %Difference (%D) at each position to radioactivity concentrations (kBq/mL) and central point. Results: Radioactivity concentrations of central point of emission scan is 2.30 kBq/mL and is indicated as 1.95, 1.82 and 1.75 kBq/mL, relatively for +x axis, as 2.07, 1.75 and 1.65 kBq/mL for -x axis, as 2.07, 1.87 and 1.90 kBq/mL for +y axis and as 2.17, 1.85 and 1.67 kBq/mL for -y axis. Also, %D is yield as 15, 20, 23% for +x axis, as 9, 23, 28% for -x axis, as 12, 21, 20% for +y axis and as 8, 22, 29% for -y axis. When using AC position changing method, it is indicated as 2.00, 1.95 and 1.80 kBq/mL, relatively for +x axis, as 2.25, 2.15 and 1.90 kBq/mL for -x axis, as 2.07, 1.90 and 1.90 kBq/mL for +y axis, and as 2.10, 2.02, and 1.72 kBq/mL for -y axis. Also, %D is yield as 13, 15, 21% for +x axis, as 2, 6, 17% for -x axis, as 9, 17, 17% for +y axis, and as 8, 12, 25% for -y axis. Conclusion: When in inconsistency of AC, radioactivity concentrations for using AC position changing method increased average of 0.14, 0.03 kBq/mL at x, y axis and %D was improved 6.1, 4.2%. Also, it is indicated that the more far from the central point and the further position from the central point under the features that spatial resolution is lowered, the higher in lowering of radioactivity concentrations. However, since in actual clinic, attenuation degree increases more, it is considered that when in inconsistency, such tolerance will be increased. Therefore, at the lesion of the part where AC is not inconsistent, the tolerance of radioactivity concentrations will be reduced by applying AC position changing method.

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Effect of Cadmium on Organic Acid Transport System in Renal Basolateral Membrane

  • Kim, Ghi-Chan;Kim, Kyoung-Ryong;Kim, Jee-Yeun;Park, Yang-Saeng
    • The Korean Journal of Physiology
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    • v.30 no.2
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    • pp.279-288
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    • 1996
  • Chronic exposure to cadmium impairs various renal tubular functions, including organic acid (anion) secretion. To investigate the mechanism of cadmium-induced alterations in the organic anion transport system, kinetics of p-aminohippurate (PAH) uptake was studied in renal cortical basolateral membrane vesicles (BLMV) isolated from cadmium-intoxicated rats (adult male Sprague-Dawley). Cadmium intoxication was induced by subcutaneous injections of $CdCl_{2}$ (2 mg Cd/kg per day) for 3 weeks. The renal plasma membrane vesicles were prepared by Percoll gradient centrifugation. The vesicular uptake of $^{14}C$-PAH was determined by rapid filtration technique using Millipore filter. Cadmium intoxication resulted in a marked attenuation of $Na^{+}$-dependent, ${\alpha}$-ketoglutarate (${\alpha}$KG)-driven PAH uptake with no changes in $Na^{+}$ and ${\alpha}$KG-independent transport component. Kinetic analysis indicated that Vmax, but not Km, of the $Na^{+}$-dependent, ${\alpha}$KG-driven component was reduced. A similar reduction of $Na^{+}$-dependent, ${\alpha}$KG-driven PAH uptake was observed in normal membrane vesicles directly exposed to inorganic cadmium in vitro, and this was accompanied by an inhibition of both $Na^{+}$-dependent ${\alpha}$KG uptake and ${\alpha}$KG-PAH exchange activity. These results indicate that during chronic exposure to cadmium, free cadmium ions liberated in the proximal tubular cytoplasm directly interact with the basolateral membrane and impair the active transport capacity for organic anions, most likely due to an inhibition of both $Na^{+}$-dicarboxylate cotransporter and dicarboxylate-organic anion antiporter activities.

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1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) Modulates Th2 Immunity through Attenuation of IL-4 Expression

  • Yoon, Sun Young;Kang, Ho Bum;Ko, Young-Eun;Shin, Su-Hyun;Kim, Young-Jun;Sohn, Ki-Young;Han, Yong-Hae;Chong, Saeho;Kim, Jae Wha
    • IMMUNE NETWORK
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    • v.15 no.2
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    • pp.100-109
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    • 2015
  • Controlling balance between T-helper type 1 (Th1) and T-helper type 2 (Th2) plays a pivotal role in maintaining the biological rhythm of Th1/Th2 and circumventing diseases caused by Th1/Th2 imbalance. Interleukin 4 (IL-4) is a Th2-type cytokine and often associated with hypersensitivity-related diseases such as atopic dermatitis and allergies when overexpressed. In this study, we have tried to elucidate the function of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) as an essential modulator of Th1/Th2 balance. EC-18 has showed an inhibitory effect on the production of IL-4 in a dose-dependent manner. RT-PCR analysis has proved EC-18 affect the transcription of IL-4. By analyzing the phosphorylation status of Signal transducer and activator of transcription 6 (STAT6), which is a transcriptional activator of IL-4 expression, we discovered that EC-18 induced the decrease of STAT6 activity in several stimulated cell lines, which was also showed in STAT6 reporter analysis. Co-treatment of EC-18 significantly weakened atopy-like phenotypes in mice treated with an allergen. Collectively, our results suggest that EC-18 is a potent Th2 modulating factor by regulating the transcription of IL-4 via STAT6 modulation, and could be developed for immune-modulatory therapeutics.

Anti-inflammatory effect of Salviae Miltiorrhizae Radix (단삼 (Salviae Miltiorrhizae Radix) 메탄올 추출물의 항염증 효과)

  • Yun, Hyun-Jeong;Heo, Sook-Kyoung;Yun, Hyung-Joong;Park, Won-Hwan;Park, Sun-Dong
    • The Korea Journal of Herbology
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    • v.22 no.4
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    • pp.65-73
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    • 2007
  • Objective : Salvia miltiorrhiza Bunge (Labiatae) (SM), an eminent herbal plant, has been widely used in traditional Chinese medicine for the treatment of vascular diseases such as hypertension. The aim of this study was to determine whether SM inhibits production of nitrite, an index of NO, and proinflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. And this study investigated whether or not SM could reduce tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced inflammatory response in human vascular aortic smooth muscle cells (HASMC) and umbilical vein endothelial cells (HUVEC). Methods : Cytotoxic activity of SM on RAW 264.7 cells was using 5-(3-caroboxymeth-oxy phenyJ)-2H-tetra-zolium inner salt (MTS) assay. We measured the NO production using Griess Reagent System. Production of Proliflammatory cytokines was measured by Enzyme-Linked Immunosorbent Assay (ELISA). Results : Our results indicated that SM significantly inhibited the LPS-induced NO production accompanied by an attenuation of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), IL-6 and monocyte chemoattractant protein (MCP)-1 formation in macrophages. SM decreased TNF-${\alpha}$-induced IL-8, IL-6 production, and intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 expression. Conclusion : These results indicate that SM has potential as an anti-inflammatory agent.

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Antioxidant Effects of Ascorbic Acid on Renal-Ischemia Reperfusion Injury in Rabbit Model

  • Kim, Jong-Man;Lee, Jae-Yeon;Kim, Duck-Hwan;Jeong, Seong-Mok;Park, Chang-Sik;Kim, Myung-Cheol
    • Journal of Veterinary Clinics
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    • v.25 no.3
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    • pp.165-169
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    • 2008
  • Renal ischemia-reperfusion (I/R) injury is great clinical important because viability of the organ depends on the tolerance to ischemia-reperfusion injury, an inevitable processing during surgery. The purpose of this study was to investigate the effects of premedicated ascorbic acid alone in I/R injury model induced by cross-clamping of renal vessels. In the rabbit models, 2-4 kg New Zealand white rabbits were subjected to 30 minutes of warm unilateral renal ischemia followed by removal of contralateral kidney and then divided into five groups, control (2) arid treatment groups (3). In control group 1, the rabbits only received right nephrectomy. In control group 2, the rabbits received I/R on left kidney after the right nephrectomy. In treatment group 1, the rabbits received ascorbic acid 50 mg/kg IV before the operation. In treatment group 2, the rabbits received ascorbic acid 100 mg/kg IV before the operation. In treatment group 3, the rabbits received ascorbic acid 200 mg/kg IV before the operation. Blood samples were collected from these rabbits for measurement of kidney function tests at the 0, 1 st, 3rd and 7th day and antioxidant enzyme( SOD, GSHPx, CAT) at 24 hours. Kidney function tests (serum creatinine and BUN) showed a significant difference between group 2 and group 4, 5. Activity of antioxidant enzymes in plasma were significant decrease in group 4, 5 compare to group 2. The result of this study suggested that the exogenous ascorbic acid had a role of attenuation of renal I/R injury in rabbit model.

Anti-oxidative and anti-inflammatory effect of Do-Ki-Tang methanol extract in mouse macrophage cells (마우스 대식세포에서 도기탕 (導氣湯) 메탄올 추출물의 항산화 및 항염증 효과)

  • Kim, Dong-Wan;Yun, Hyun-Jeong;Heo, Jun-Young;Kim, Tae-Hoon;Cho, Hyun-Jin;Park, Sun-Dong
    • The Korea Journal of Herbology
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    • v.25 no.4
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    • pp.103-112
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    • 2010
  • Objective : The aim of this study was to determine whether methanol extract of Do-Ki-Tang (DKT) inhibit free radical generation and production of nitrite an index of NO, $PGE_2$, iNOS, COX-2 and pro-inflammatory cytokines such as TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Methods : Cytotoxic activity of extract on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. The expression level of inflammatory response-related proteins was confirmed by western blot. The production of proinflammatory cytokines was measured by ELISA. Results : Our results indicated that DKT scavenged DPPH radical and nitric oxide in vitro. Moreover, DKT significantly inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and MCP-1 formation in macrophages. Furthermore, DKT treatment also blocked LPS-induced intracellular ROS production and the activation of NF-${\kappa}B$ and MAPKs. Conclusion : Our data suggest that the anti-inflammatory effect of DKT is mediated through down-modulation of pro-inflammatory mediators and cytokines by blocking the signaling pathways of NF-${\kappa}B$ and MAPKs. These inhibitory effects by DKT represent a potential therapeutic approach to the treatment of inflammatory diseases.

Antiplatelet Effects of Cordycepin-Enriched WIB-801CE from Cordyceps militaris: Involvement of Thromboxane A2, Serotonin, Cyclooxygenase-1, Thromboxane A2 Synthase, Cytosolic Phospholipase A2

  • Ok, Woo Jeong;Nam, Gi Suk;Kim, Min Ji;Kwon, Hyuk-Woo;Kim, Hyun-Hong;Shin, Jung-Hae;Lim, Deok Hwi;Kwon, Ho-Kyun;Lee, Chang-Hwan;Chung, Soo-Hak;Kim, Jong-Lae;Park, Hwa-Jin
    • Biomedical Science Letters
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    • v.22 no.4
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    • pp.127-139
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    • 2016
  • A species of the fungal genus Cordyceps has been used as an ingredient of traditional Chinese medicine. In this study, we prepared cordycepin-enriched WIB-801CE, an ethanol extract from culture solution of Cordyceps militaris-hypha, and evaluated its antiplatelet effects on human platelet aggregation. WIB-801CE dose-dependently inhibited ADP-, collagen-, and thrombin-induced platelet aggregation. These antiplatelet effects by WIB-801CE were associated with the attenuation of thromboxane $A_2$ ($TXA_2$) production and serotonin release by ADP, collagen, and thrombin. The inhibition of $TXA_2$ production by WIB-801CE was due to the inhibition of cyclooxygenase-1, $TXA_2$ synthase, and cytosolic phospholipase $A_2$ activity. Therefore, these data suggest that WIB-801CE may be a beneficial component against protection from platelet aggregation-mediated thrombotic disease.

Effects of Central GABA and Glutamate on Blood Pressure and Single Unit Spikes in the RVLM of Rats

  • Park, Jae-Sik;Lee, Zee-Ihn;Jang, Jae-Hee;Ahn, Dong-Kuk
    • The Korean Journal of Physiology and Pharmacology
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    • v.6 no.3
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    • pp.149-154
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    • 2002
  • The blood pressure (BP) is regulated by the nervous system and humoral factors, such as renin- angiotensin system, vasopressin and others. In the present study, we examined the central effects of glutamate and GABA on the cardiovascular regulation by injection of these substances into the lateral ventricle and also investigated the relationship between these central effects and the action of angiotensin II (Ang). Male Sprague Dawley rats, $350{\sim}400$ g, were anesthetized with urethane and instrumented with an arterial catheter for direct measurement of BP and heart rate (HR), and an guide cannula in the lateral ventricle for drug injection. A glass microelectode was inserted into the rostral ventrolateral medulla (RVLM) for recording single unit spikes. Barosensitive neurons were identified by changes of single unit spikes in RVLM following intravenous injection of nitroprusside and phenylephrine. The effects of GABA and glutamate injected into the lateral ventricle were studied in single neuronal activity of the RVLM in addition to changes in BP and heart rate, and compared the results before and after treatment with intravenous losartan, nonpeptide Ang II-type 1 receptor antagonist (1 mg/100 g BW). Intracerebroventricular administration of GABA decreased systolic blood pressure (SBP) and HR, but increased the firing rates in the RVLM. However, intracerebroventricular glutamate injection produced effects opposite to GABA. After pretreatment of intravenous losartan, the central effects of GABA on BP and firing rate in the RVLM were significantly attenuated and that of glutamate showed a tendency of attenuation. These results suggested that central GABA and glutamate regulated BP and firing rates in RVLM were inversely related to BP change. The central effects of GABA or glutamate on the autonomic nervous function were modulated by humoral factor, Ang II, by maintaining BP.

Anti-inflammatory effect of Rumex japonicus HOUTT. in RAW 264.7 cells (양제근(Rumex japonicus HOUTT.)분획의 항염증 효과)

  • Huh, Jun-Yong;Cho, Hyun-Jin;Park, Ki-jeong;Park, Sun-Dong
    • The Korea Journal of Herbology
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    • v.27 no.4
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    • pp.99-107
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    • 2012
  • Objectives : The aim of this study was to authenticate whether fractionated extract of Rumex japonicus HOUTT. (RJ) has anti-inflammatory effects in mouse macrophage, RAW264.7 cells. Methods : Roots of RJ were extracted by methanol for 48hours. The methanol that gained was filtered and freeze dried. The methanol extract was dissolved in water and dichloromethane (DCM). After that, two layers were separated. Ethyl acetate (EA) added to the water layer and separated again. All the layers were filtered and freeze dried and the extracts were tested. Cytotoxic activity of extracts on RAW 264.7 cells was measured using MTS assay. The nitric oxide (NO) production was measured and proinflammatory cytokines and $PGE_2$ were measured by ELISA kit. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), I ${\kappa}$-B-${\alpha}$ and nuclear NF-${\kappa}B$ p65 expression were detected by western blot. Results : Our results indicated that DCM and EA extracts of RJ inhibited the LPS-induced NO, $PGE_2$ production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 production in RAW 264.7 cells most effectively. DCM and EA extracts also had suppression effects of LPS-induced NF-${\kappa}B$ and MAPKs activation. Conclusions : This results demonstrate that fractionated extract of RJ has anti-inflammatory effects and among the fractioned extract, dichloromethane and ethyl acetate extract have best anti-inflammatory effects.

Comparative Study on the Attenuation of P and S Waves in the Crust of the Southeastern Korea (한국 남동부 지각의 P파와 5파 감쇠구조 비교연구)

  • Chung, Tae-Woong
    • Journal of the Korean earth science society
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    • v.22 no.2
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    • pp.112-119
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    • 2001
  • The Yangsan fault in the southeastern Korea has been receiving increasing attention in its seismic activity. In this fault region, by using the extended coda-normalization method for 707 seismograms of local earthquakes, were obtained 0.009f$^{-1.05}$ and 0.004f$^{-0.70}$ for fitting values of Q$_p^{-1}$ and Q$_s^{-1}$, respectively. These results indicate that Q$_p^{-1}$ and Q$_s^{-1}$ in the southeastern Korea is the lowest level in the world although the exponent values agree well with those in the other areas. The low Q-1 is not related to the movement of the Yangsan fault but to the tectonically inactive status like a shield area.

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