• Title/Summary/Keyword: Oxygen extraction fraction

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Moisturizing and Anti-oxidation Effect of Astragalus membranaceus Root Extract (황기추출물의 보습 및 항산화 효과)

  • Jung, Taek-Kyu;Kim, Mi-Jin;Lim, Kyung-Ran;Yoon, Kyung-Sup
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.3 s.58
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    • pp.193-200
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    • 2006
  • We investigated the effect of moisturizing and anti-oxidation of Astragalus membranaceus (Astragali Radix) root extract with respective to growing districts and extract methods for the purpose of development of cosmetic ingredients. Astragalii Radix was collected in Jecheon, Jeongseon, Taebaek, and Yeongju in Korea and China as growing districts. Formononetin was determinated by HPLC method as one of the various active agents in Astragalus membranaceus root extract. The 75% ethanol extract demonstrated to be more effective than $H_2O$-extracted one for a scavenging activities to DPPH radicals and reactive oxygens. The 75% ethanol extract showed $IC_{50}$ (50% scavenging concentration) of 2.162 mg/mL and 2.981 mg/mL in case of free radical scavenging activity test and reactive oxygen scavenging activity test, respectively Especially, free radical scavenging activity of isoflavonoids isolated from ethylacetate fraction was similar to scavenging activity of genistein. Astragalus membranaceus root extract of Jecheon district by sonicating extraction method was more effective in skin hydration compared with others.

Relationship between Abnormal Hyperintensity on T2-Weighted Images Around Developmental Venous Anomalies and Magnetic Susceptibility of Their Collecting Veins: In-Vivo Quantitative Susceptibility Mapping Study

  • Yangsean Choi;Jinhee Jang;Yoonho Nam;Na-Young Shin;Hyun Seok Choi;So-Lyung Jung;Kook-Jin Ahn;Bum-soo Kim
    • Korean Journal of Radiology
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    • v.20 no.4
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    • pp.662-670
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    • 2019
  • Objective: A developmental venous anomaly (DVA) is a vascular malformation of ambiguous clinical significance. We aimed to quantify the susceptibility of draining veins (χvein) in DVA and determine its significance with respect to oxygen metabolism using quantitative susceptibility mapping (QSM). Materials and Methods: Brain magnetic resonance imaging of 27 consecutive patients with incidentally detected DVAs were retrospectively reviewed. Based on the presence of abnormal hyperintensity on T2-weighted images (T2WI) in the brain parenchyma adjacent to DVA, the patients were grouped into edema (E+, n = 9) and non-edema (E-, n = 18) groups. A 3T MR scanner was used to obtain fully flow-compensated gradient echo images for susceptibility-weighted imaging with source images used for QSM processing. The χvein was measured semi-automatically using QSM. The normalized χvein was also estimated. Clinical and MR measurements were compared between the E+ and E- groups using Student's t-test or Mann-Whitney U test. Correlations between the χvein and area of hyperintensity on T2WI and between χvein and diameter of the collecting veins were assessed. The correlation coefficient was also calculated using normalized veins. Results: The DVAs of the E+ group had significantly higher χvein (196.5 ± 27.9 vs. 167.7 ± 33.6, p = 0.036) and larger diameter of the draining veins (p = 0.006), and patients were older (p = 0.006) than those in the E- group. The χvein was also linearly correlated with the hyperintense area on T2WI (r = 0.633, 95% confidence interval 0.333-0.817, p < 0.001). Conclusion: DVAs with abnormal hyperintensity on T2WI have higher susceptibility values for draining veins, indicating an increased oxygen extraction fraction that might be associated with venous congestion.

Evaluation of Hemodynamic Failure with Acetazolamide Challenged $^{123}I-IMP$ Brain SEPCT and PET (PET과 Acetazolamide 부하 $^{123}I-IMP$ 뇌혈류 SPECT를 이용한 혈역학적 부전의 평가)

  • Chun, Kyung-Ah;Cho, In-Ho;Won, Kyu-Jang;Lee, Hyung-Woo;Hayashida, Kohei
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.2
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    • pp.94-102
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    • 2003
  • Purpose : Cerebral blood flow (CBF) reactivity to acetazolamide (ACZ) is useful to select patients with hemodynamic failure. However, it is still a matter of speculation that varying degrees of regional CBF increases after ACZ administration represent the severity or stage of regional hemodynamic failure as assessed by positron emission tomography (PET). We studied to elucidate whether ACZ challenge $^{123}I-IMP$ brain single photon emission tomography (SPECT) can accurately grade the seventy of regional hemodynamic failure. Materials and Methods: Eighteen patients (M: 16, F: 2, average age: 61 years) with unilateral occlusive disease of the internal carotid artery or the trunk of the middle cerebral artery (MCA). Patients undewent $^{123}I-IMP$ brain SPECT study with acetazolamide challenge and PET study was carried out within 2 weeks before and after SPECT study. Five healthy volunteers with a mean age of 48 years (range: 28-73 yr, M: 3, F: 2) underwent PET studies to determine normal values. In SPECT study, an asymmetry index (Al)-the percentage of radioactivity of region of interest (ROI) in the occlusive cerebrovascular lesion to the contralateral homologous ROI-was used for numerical evaluation of relative $^{123}I-IMP$ distribution. In PET study, regional CBF, oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen ($CMRO_2$) and cerebral blood volume (CBV) values were measured with $^{15}O-labeled$ gas inhalation method and the values were used for comparison with Al (Al during acetazolamide challenge-Al of basal study) on the SPECT study. ROls were classified by severity into three groups (normal, stage I and stage II). Results: Mean values of Al in areas with normal, stage I and stage II hemodynamic failure were $6.25{\pm}7.77%\;(n=107),\;-10.38{\pm}10.41%\:(n=117)\;and\;13.30{\pm}10.51%\;(n=140)$, respectively. Al significantly differed with each groups (p<0.05). Correlation between Al and CBF, OEF and CBV/CBF in hemisphere with occlusive cerebrovascular lesion was 0.20 (p<0.01), -0.28 (p<0.01) and -0.28 (p<0.01), respectively. Conclusion: We concluded that $^{123}I-IMP$ brain SPECT with acetazolamide challenge could determine the severity ad stage of regional hemodynamic failure as assessed by PET.