• Title/Summary/Keyword: Dose attenuation

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A Method and Effect for Tibial Defect Treatment Using Interstitial Low Level Laser (경골 손상 치료에서의 침습형 저출력 레이저 치료법 및 효과)

  • Lee, Sangyeob;Hwang, Donghyun;Kim, Hansung;Jung, Byungjo
    • Journal of Biomedical Engineering Research
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    • v.37 no.4
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    • pp.147-151
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    • 2016
  • Tibial defect, or fracture is very routine musculoskeletal case which brings fully uncomfortable and painful situations to patient. Moreover, it has long hospitalization period because of its risk of non-union. There are many studies using ultrasound, vibration, and laser for bone regeneration to figure out fast bone healing. Among them, Low Level Laser Therapy (LLLT) is already known that it is very easy to treat and may have positive effect for bone regeneration. However, LLLT has uncertain energy dose because of scattering and absorption of laser in tissue. In this study, we used interstitial LLLT to treat tibial defect in animal study. The Interstitial LLLT can overcome some limitations caused by laser scattering or absorption in tissue medium. The results were evaluated using u-CT which can calculate X-ray attenuation coefficient and bone volume of bone defect area. These results showed that interstitial LLLT may affect fast bone healing process in early phase.

Cytoprotective effect of rhamnetin on miconazole-induced H9c2 cell damage

  • Lee, Kang Pa;Kim, Jai-Eun;Park, Won-Hwan
    • Nutrition Research and Practice
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    • v.9 no.6
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    • pp.586-591
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    • 2015
  • BACKGROUND/OBJECTIVES: Reactive oxygen species (ROS) formation is closely related to miconazole-induced heart dysfunction. Although rhamnetin has antioxidant effects, it remained unknown whether it can protect against miconazole-induced cardiomyocyte apoptosis. Thus, we investigated the effects of rhamnetin on miconazole-stimulated H9c2 cell apoptosis. MATERIALS/METHODS: Cell morphology was observed by inverted microscope and cell viability was determined using a WelCount$^{TM}$ cell proliferation assay kit. Miconazole-induced ROS production was evaluated by fluorescence-activated cell sorting with 6-carboxy-2',7'-dichlorofluoroscein diacetate ($H_2DCF$-DA) stain. Immunoblot analysis was used to determine apurinic/apyrimidinic endonuclease 1 (APE/Ref-1) and cleaved cysteine-aspartic protease (caspase) 3 expression. NADPH oxidase levels were measured using real-time polymerase chain reaction. RESULTS: Miconazole (3 and $10{\mu}M$) induced abnormal morphological changes and cell death in H9c2 cells. Rhamnetin enhanced the viability of miconazole ($3{\mu}M$)-treated cells in a dose-dependent manner. Rhamnetin (1 and $3{\mu}M$) treatment downregulated cleaved caspase 3 and upregulated APE/Ref-1 expression in miconazole-stimulated cells. Additionally, rhamnetin significantly reduced ROS generation. CONCLUSIONS: Our data suggest that rhamnetin may have cytoprotective effects in miconazole-stimulated H9c2 cardiomyocytes via ROS inhibition. This effect most likely occurs through the upregulation of APE/Ref-1 and attenuation of hydrogen peroxide levels.

High alloyed new stainless steel shielding material for gamma and fast neutron radiation

  • Aygun, Bunyamin
    • Nuclear Engineering and Technology
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    • v.52 no.3
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    • pp.647-653
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    • 2020
  • Stainless steel is used commonly in nuclear applications for shielding radiation, so in this study, three different types of new stainless steel samples were designed and developed. New stainless steel compound ratios were determined by using Monte Carlo Simulation program Geant 4 code. In the sample production, iron (Fe), nickel (Ni), chromium (Cr), silicium (Si), sulphur (S), carbon (C), molybdenum (Mo), manganese (Mn), wolfram (W), rhenium (Re), titanium (Ti) and vanadium (V), powder materials were used with powder metallurgy method. Total macroscopic cross sections, mean free path and transmission number were calculated for the fast neutron radiation shielding by using (Geant 4) code. In addition to neutron shielding, the gamma absorption parameters such as mass attenuation coefficients (MACs) and half value layer (HVL) were calculated using Win-XCOM software. Sulfuric acid abrasion and compressive strength tests were carried out and all samples showed good resistance to acid wear and pressure force. The neutron equivalent dose was measured using an average 4.5 MeV energy fast neutron source. Results were compared to 316LN type stainless steel, which commonly used in shielding radiation. New stainless steel samples were found to absorb neutron better than 316LN stainless steel at both low and high temperatures.

Effect of imipramine or ECS on central $\beta_1$and $\beta_2$receptor Sensitivity in the Cardiovascular Response of Rat

  • Sohn, Uy-Dong;Kim, Choong-Young;Huh, In-Hoi
    • Archives of Pharmacal Research
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    • v.12 no.4
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    • pp.282-288
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    • 1989
  • This study was investigated the effects of imipramine (IMI) and electroconvulsive shock (ECS), which are used as antidepressant therapy, on the central $\beta_1$or $\beta_2$ adrenergic receptor in anesthetized rats. The resting blood pressure and heart rate decreased in reserpinized group (5 mg/kg i. p., 24 hr before), but not in order 4 groups i. e. acute IMI (20 mg/kg i. p.. 3-5 hr before), chronic IMI (Same dose, twice a day for 14 days), siggle ECS (sinusoidal 20 Hz, 120 V for 2 sec) and repeated ECS (same condition, daily for 12 days). The increase of heart rate and hypotension evoked by 1 or 3 $\mu$g intracerebroventricular (i. c. v.) administration of (+) dobutamine, $\beta_2$-agonist, 1 or 3 $\mu$g i. c. v. was significantly attenuated in repeated ECS or reserpine treatment. And, the diminuation of pulse pressure of salbutamol also reduced by repeated ECS. These results suggest that IMI or ECS result in attenuation on tachycardia by (+) dobutamine or on hypotension by salbutamol, presumably by which the central $\beta_1$ or $\beta_2$receptor sensitivity may be suppressed, repectively.

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Effect of Rhizoma gastrodiae on glucose oxydase induced neurotoxicity in cultured mouse spinal dorsal root ganglion neurons

  • Park, Seung-Taeck;Park, Yang-Kyu;Park, Jae-Hwang;Cho, Kwang-Ho;Ryu, Do-Gon;Jeon, Byung-Hoon;Shin, Min-Kyo;Han, Du-Seok;Cho, Nam-Su;Shin, Dong-Min
    • Advances in Traditional Medicine
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    • v.1 no.1
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    • pp.64-70
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    • 2000
  • Effects of Rhizoma gastrodiae on glucose oxidase-induced neurotoxicity was investigated in cultured newborn mouse spinal dorsal root ganglion(DRG) neurons that were treated in the media with or without glucose oxidase. In addition, the protective effect of Rhizoma gastrodiae extract against glucose oxidase-induced neurotoxicity was examined. Cytotoxic values were expressed as a percentage of number of living cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In this paper, exposure of neurons to glucose oxidase resulted in a significant call death in a dose- and time-dependent manners in DRG neuron cultures. The decrease in cell viability induced by the glucose oxidase was blocked by Rhizoma gastrodiae extract. These results indicate that the neuroprotective effect of Rhizoma gastrodiae extract against glucose oxidase-induced neurotoxicity may result from a prevention or attenuation of oxidative damage induced by glucose oxidase.

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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.