• Title/Summary/Keyword: Dose Attenuation

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Inhibition of Red Ginseng on 5-Hydroxyeicosatetraenoic Acid (5-HETE) Biosynthesis from Arachidonic Acid in Helicobacter Pylori-infected Gastric Cells

  • Park Soo-Jin
    • Nutritional Sciences
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    • v.9 no.3
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    • pp.152-158
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    • 2006
  • Helicobacter pylori (H. pylori) infection rapidly stimulated either COX-2 or 5-LOX and released arachidonic acid metabolites that have been considered as pivotal mediators in H. pylori-induced inflammatory responses. To determine whether red ginseng extract (RGE) can suppress the biosynthesis of 5(S)-hydroxyeicosatetraenoic acids (HETE), a precursor metabolite of leukotrienes B4 (LTB4) in H. pylori-provoked inflammatory responses in gastric epithelial cells, the biosynthesis of monohydroxy fatty acids was measured using radioactive arachidonic acid and validated by RP-HPLC using non-radioactive AA as substrate in AGS cells cocultured with H. pylori (ATCC 43504) with or without pretreatment of RGE. Among three known major HETEs, H. pylori infection specifically induced the biosynthesis of $^{14}C-5(S)-HETE$ rather than the complex of $^{14}C-15S-/^{14}C-12(S)-HETE$ from $^{14}C-AA$, concomitantly obtained by HPLC(p<0.01). RGE, 1 to $100{\mu}g/ml$, selectively suppressed H. pylori-stimulated $^{14}C-5(S)-HETE$ production implying the attenuation of 5-lipoxygenase activity, of which was similar to known LOX inhibitor NDGA $(10{\mu}M)$ (p<0.01). However, the amount of 5(S)-HETE was significantly reduced by higher dose of RGE $(100{\mu}g/ml)$ (p<0.05). These results indicated that LOX pathway might be one of principle pathogenic mechanisms of H. pylori and red ginseng could be a nutraceutical against H. pylori infection through inhibiting action of LOX activity.

Protective Effect of Water Extract of Fraxinus Rhynchophylla Leaves on Acetaminophen-induced Nephrotoxicity in Mice and Its Phenolic Compounds

  • Jeon, Jeong-Ryae;Choi, Joon-Hyuk
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.988-993
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    • 2007
  • The protective effect of the water extract of Fraxinus rhynchophylla leaves (FLE) was determined using an animal model of acetaminophen (AAP)-induced nephrotoxicity. The BALB/c male mice used in this study were divided into 3 groups; the normal, AAP-administered, and FLE-pretreated AAP groups. A single dose of AAP induced necrosis of renal tubules and congestion along with edema to a remarkable degree as observed by hematoxylin and eosin stain, and also increased the numbers of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL)-positive renal tubular epithelial cells. Blood urea nitrogen and plasma creatinine levels were determined to be significantly higher in the AAP group than in the normal group. However, FLE pretreatment resulted in an attenuation of renal tubule necrosis. Regeneration and dilatation of renal tubules were noted, and the numbers of TUNEL-positive cells were reduced in the FLE-pretreated groups. In an effort to detect the bioactive compounds exerting protective effects in FLE, the analysis of phenolic compounds via gas chromatography/mass spectrometry (GC/MS) were performed, and identified esculetin and esculin. The present study indicates that these compounds may exert a protective effect against AAP-induced nephrotoxicity.

The Effect of Centrally Active Antihypertensive Agent on Biosynthetic Enzyme Activity of Neurotransmitter in Brain (중추성 항고혈압약이 뇌내 신경전달물질의 생합성 효소에 미치는 영향)

  • 윤재순
    • YAKHAK HOEJI
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    • v.29 no.4
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    • pp.165-175
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    • 1985
  • It has been reported that clonidine is $\alpha_2$-adrenergic agonist, potnet new hypotensive drug in human with low dose. The change in blood pressure is implicated in the concentration, release, uptake and metabalism of catecholamine and activity of catecholamine synthesizing enzyme in specific brain areas. Thus the experiment was set up to investigate the effect on the enzyme activity of clonidine alone and that of clonidine pretreated with imipramine or tranylcypromine by measuring activity of the Dopa-forming enzyme, tyrosine hydroxylase (TH) and epinephrine forming enzyme, phenylethanolamine-N-methyl transferase (PNMT) in brain and adrenal gland. The TH activity in brainstem and substantia nigra is decreased by intraperitoneally administered clonidine 0.1mg/kg twice a day for 5 days, but increased in the rats pretreated with imipramine 10mg/kg intraperitoneally given 26 hrs and 5 hrs before decaptitation. However the TH activity in all regions of brain is increased in rats pretreated with tranylcypromine 10mg/kg intraperitoneally twice a day for 5 days. The effect of clonidine on TH activity is due to inhibition release of norepinephrine by activation of presynaptic $\alpha_2$-adrenoreceptor, axon terminal result in the decrease of TH activity in brain. The increasing of TH activity in brain results in attenuation of the role of clonidine by pretreated with imipramine or tranylcypromine in rats. The activity of PNMT was not significantly affected by clonidine, imipramine and tranylcypromine in adrenal gland.

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High-Dose Nicotinamide Suppresses ROS Generation and Augments Population Expansion during CD8+ T Cell Activation

  • Choi, Ho Jin;Jang, So-Young;Hwang, Eun Seong
    • Molecules and Cells
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    • v.38 no.10
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    • pp.918-924
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    • 2015
  • During T cell activation, mitochondrial content increases to meet the high energy demand of rapid cell proliferation. With this increase, the level of reactive oxygen species (ROS) also increases and causes the rapid apoptotic death of activated cells, thereby facilitating T cell homeostasis. Nicotinamide (NAM) has previously been shown to enhance mitochondria quality and extend the replicative life span of human fibroblasts. In this study, we examined the effect of NAM on $CD8^+$ T cell activation. NAM treatment attenuated the increase of mitochondrial content and ROS in T cells activated by CD3/CD28 antibodies. This was accompanied by an accelerated and higher-level clonal expansion resulting from attenuated apoptotic death but not increased division of the activated cells. Attenuation of ROS-triggered pro-apoptotic events and upregulation of Bcl-2 expression appeared to be involved. Although cells activated in the presence of NAM exhibited compromised cytokine gene expression, our results suggest a means to augment the size of T cell expansion during activation without consuming their limited replicative potential.

Enhancement of Alcohol Metabolism by Sprouted Peanut Extract in SD Rats

  • Seo, Ji Yeon;Kim, Seong Soon;Kim, Jong-Sang
    • Preventive Nutrition and Food Science
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    • v.19 no.1
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    • pp.1-4
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    • 2014
  • Excessive ethanol intake is known to induce a number of physiological symptoms, including headache, dizziness and vertigo. In this study, we investigated the attenuation effect of sprouted peanut extract (SPE) on ethanol-induced hangover in male Sprague-Dawley rats. The animals were divided into five groups: the control group, which was administered ethanol only; the ethanol plus SPE experimental groups, which were administered ethanol and 100, 200, or 400 mg SPE/kg b.w.; and the positive control group, which was administered ethanol plus DAWN808$^{(R)}$, a commercial product. SPE-suspended water was delivered to rats via gavage 15 h and 30 min before the administration of ethanol. Blood was collected from the tail 0, 1, 3, and 5 h after ethanol administration. The results showed that serum ethanol concentrations were significantly lower in SPE treated groups than in the control group. Furthermore, hepatic alcohol and acetaldehyde dehydrogenase activities were enhanced by SPE in a dose dependent manner. These results suggest that SPE could be useful in attenuating hangover after alcohol consumption.

Streptozotocin-Induced Pro-Inflammatory Response in Rat Blood and its Attenuation by External Albumin Administration

  • Bae, Chun-Sik;Lee, Chang-Min;Kim, Dong-il;Ahn, Taeho
    • Journal of Veterinary Clinics
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    • v.36 no.3
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    • pp.145-149
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    • 2019
  • Previous report has suggested that the albumin levels were reduced in the peripheral blood mononuclear cells (PBMCs) and consequently oxidative stress was elevated in streptozotocin (STZ)-induced diabetic rats as albumin is the predominant antioxidant in plasma. In this study, we suggest that the levels of pro-inflammatory cytokine such as interleukin-6 (IL-6) and tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$) were increased by approximately 3.4- and 2.9-fold, respectively, in the serum of STZ-diabetic rats, compared to those of normal rat. In addition to the cytokines, the levels of C-reactive protein (CRP) were also about 3.6-fold higher, indicating that STZ induced a pro-inflammatory response in rat blood. However, when purified rat albumin was externally co-administrated with STZ through the tail vein, the serum levels of IL-6, $TNF-{\alpha}$, and CRP were markedly reduced, although the values were still higher than those of normal (non-diabetic) rats. Albumin administration also decreased STZ-induced oxidative stress in serum and PBMCs. Moreover, the decrease in cytokine and CRP levels was dependent on the dose of injected albumin. These results suggest that STZ-induced pro-inflammation and oxidative stress in rat blood might be attenuated by treatment with exogenous albumin.

Evaluation of Image Quality for Diagnostic Digital Chest Image Using Ion Chamber in the Total Mastectomy (변형근치유방절제술 환자의 Ion chamber 변화에 따른 디지털 흉부 영상의 화질 평가)

  • Lee, Jin-Soo;Ko, Seong-Jin;Kang, Se-Sik;Kim, Jung-Hoon;Park, Hyong-Hu;Kim, Donghyun;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.13 no.3
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    • pp.204-210
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    • 2013
  • The patients who had been operated total mastectomy are different from general women in their breasts thickness due to breast surgery. As a result, digital chest image from total mastectomy patients will be different attenuation. The main objective for this study is to show that a proper Ion chamber standard combination measuring MTF which is objective basis for Digital image, when be x-ray for total mastectomy patient. We have designed the unique number that shown Left is 1, Right is 2, Center is 3 and have put the edge phantom on detector ion chamber. Lastly, we have obtained experiment images. The evaluations of all image quality have measured by 50% MTF of spatial resolution and absorption dose using Matlab(R2007a). The result showed that average exposure condition, MTF value, absorption dose for 1+3 and 2+3 combinations were 2.745 mAs, 1.925 lp/mm, 0.688 mGy. Consequently, that showed high MTF, DQE and low dose than other combinations. Therefore, a proper changes of ion chambers are able to improve image quality and to reduce radiation exposure when be X-ray for total mastectomy patients. Also, it will be possible to standard for application chamber combination and utilization on clinical detection.

A Study on the Shielding of Iodine 131 Using Monte Carlo Simulation (몬테칼로 모사를 이용한 방사성옥소 I-131의 차폐체에 대한 효용성 연구)

  • Jang, Dong-Gun;Yang, Seoung-Oh;Kim, Jung-Ki;Lee, Sang-Ho;Choi, Hyung-Seok;Bae, Cheol-Woo
    • Journal of radiological science and technology
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    • v.37 no.2
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    • pp.143-150
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    • 2014
  • This study was designated to investigate the bremsstrahlung and radiation dose by beta rays. Radiation attenuation from I-131 treatment ward was analyzed using radio protective apron. Shielding materials which is included lead or water were simulated in Monte Carlo Simulation then the spectrum on interaction was analyzed. The shielding materials were categorized according to the thickness. 0.25mm and 0.5mm thick lead and 0.1mm and 0.2mm thick water shielding materials were configured in Monte Carlo Simulation for this study. Only lead shielding method and water plus lead shielding method were carried. As a results, when 0.5mm thick lead shielding method was performed, the radiation dose was similar to the results with water plus lead shielding method. In case of using 0.25mm thick lead shielding, the shielding effect was somewhat less. However, that shielding method cause dose reduction of about 60% compare with non-shielding material.

Validation of Deep-Learning Image Reconstruction for Low-Dose Chest Computed Tomography Scan: Emphasis on Image Quality and Noise

  • Joo Hee Kim;Hyun Jung Yoon;Eunju Lee;Injoong Kim;Yoon Ki Cha;So Hyeon Bak
    • Korean Journal of Radiology
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    • v.22 no.1
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    • pp.131-138
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    • 2021
  • Objective: Iterative reconstruction degrades image quality. Thus, further advances in image reconstruction are necessary to overcome some limitations of this technique in low-dose computed tomography (LDCT) scan of the chest. Deep-learning image reconstruction (DLIR) is a new method used to reduce dose while maintaining image quality. The purposes of this study was to evaluate image quality and noise of LDCT scan images reconstructed with DLIR and compare with those of images reconstructed with the adaptive statistical iterative reconstruction-Veo at a level of 30% (ASiR-V 30%). Materials and Methods: This retrospective study included 58 patients who underwent LDCT scan for lung cancer screening. Datasets were reconstructed with ASiR-V 30% and DLIR at medium and high levels (DLIR-M and DLIR-H, respectively). The objective image signal and noise, which represented mean attenuation value and standard deviation in Hounsfield units for the lungs, mediastinum, liver, and background air, and subjective image contrast, image noise, and conspicuity of structures were evaluated. The differences between CT scan images subjected to ASiR-V 30%, DLIR-M, and DLIR-H were evaluated. Results: Based on the objective analysis, the image signals did not significantly differ among ASiR-V 30%, DLIR-M, and DLIR-H (p = 0.949, 0.737, 0.366, and 0.358 in the lungs, mediastinum, liver, and background air, respectively). However, the noise was significantly lower in DLIR-M and DLIR-H than in ASiR-V 30% (all p < 0.001). DLIR had higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) than ASiR-V 30% (p = 0.027, < 0.001, and < 0.001 in the SNR of the lungs, mediastinum, and liver, respectively; all p < 0.001 in the CNR). According to the subjective analysis, DLIR had higher image contrast and lower image noise than ASiR-V 30% (all p < 0.001). DLIR was superior to ASiR-V 30% in identifying the pulmonary arteries and veins, trachea and bronchi, lymph nodes, and pleura and pericardium (all p < 0.001). Conclusion: DLIR significantly reduced the image noise in chest LDCT scan images compared with ASiR-V 30% while maintaining superior image quality.

Research of Protocols for Optimization of Exposure Dose in Abdominopelvic CT - (복부-골반 CT검사 시 피폭선량 최적화에 관한 프로토콜 연구)

  • Hong, Dong-Hee
    • Journal of radiological science and technology
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    • v.40 no.2
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    • pp.245-251
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    • 2017
  • This study measured the exposure dose during abdominal-pelvic CT exam which occupies 70% of CT exam and tried to propose a protocol for optimized exposure dose in abdomen and pelvis without affecting the imagery interpretation. The study scanned abdomen-pelvis using the current clinical scan method, the 120 kVp, auto exposure control(AEC), as 1 phase. As for the newly proposed 2 phase scan method, the study divided into 1 phase abdomen exam and 2 phase pelvis exam and each conducted tube voltage 120 kVp, AEC for abdomen exam, and fixed tube current method in 120 kVp, 100, 150, 200, 250, 300, 350, 400 mA for pelvis exam. The exposure dose value was compared using $CTDI_{VOL}$, DLP value measured during scan, and average value of CT attenuation coefficient, noise, SNR from each scan image were obtained to evaluate the image. As for the result, scanning of 2 phase showed significant difference compared to 1 phase. In $CTDI_{VOL}$ value, the 2 phase showed 26% decrease in abdomen, 1.8~59.5% decrease in pelvis for 100~250 mA, 12.7%~30% increase in pelvis for 300~400 mA. Also, DLP value showed 53% decrease in abdomen and 41~81% decrease in pelvis when scanned by 2 phase compared to 1 phase, but it was not statistically significant. As for the SNR, when scanning 2 phase close to heart, scanning 1 phase close to pelvis, scanning and scanning 1 phase at upper and lower abdomen, it was higher when scanning 2 phase for 200~250 mA. Also, the CT number and noise was overall similar, but the noise was high close to pelvis. However, when scanning 2 phase for 250 mA close to pelvis, the noise value came out similar to 1 phase, and did not show statistically significant difference. It seems when separating pelvis to scan in 250 mA rather than 400 mA in 1 phase as before, it is expected to have reduced effect of exposure dose without difference in the quality of image. Thus, for patients who often get abdominal-pelvic CT exam, fertile women or children, this study proposes 2 phase exam for smaller exposure dose with same image quality.