• Title/Summary/Keyword: The $\alpha$-Effect

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Effect of Allopurinol on the Ethanol-induced Oxidative Stress : Mechanism of Allopurinol Action

  • Park, Min-Kyung
    • Preventive Nutrition and Food Science
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    • v.3 no.1
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    • pp.48-55
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    • 1998
  • An acute ethanol load(50mmol/kg , i.p) resulted in an increase in peroxidation and a decrease in the levels of $\alpha$-tocopherol and ascorbate in rat cerebellum. Pretreatement with allopurinol(146$\mu$mol/kg, i.p) prevented the ethnol-induced increment in lipid peroxidation and decrease in $\alpha$-tocopherol content. However, the decrease of ascorbate was of greater magnitude when allopurinol was associated with ethanol. These results suggested that allopurinol. besides its action as a radical scavenger and xanthine oxidase inhibitor, might favor the regeneration of $\alpha$-tocopherol antioxidant acitviity was studied using ${\gamma}$-radiolysis in aerated ethanolic solutions. Even though allopurinol did not react by itself with $\alpha$-hydroxyethyl-peroxyl radicals [H3C-CH(OH)OO] , it enhance the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$tocopherol. The regeneration of $\alpha$-tocopherol from the $\alpha$-hydroxyethyl-peroxyl radical scavenging properties of $\alpha$-tocophero. The regeneration of $\alpha$-tocopherol from the $\alpha$-tocopherol radical by ascorbate remained as efficient in the presence of allopurinol as in its absence. The effects of allopurinol on the Vitamin E oxidation-reduction mechanism could be involoved in the beneficial effectof allopurinol on the biological cellular damages linked to free radical reactions.

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The Body Fat-lowering Effect of Garlic Powder in Peroxisome Proliferator-activated Receptor γ Coactivator-1α (PGC-1α)-luciferase Transgenic Mice (PGC-1α 형질전환 생쥐에서 마늘 분말의 체지방 감소 효과)

  • Lee, Mak-Soon;Kim, Yangha
    • The Korean Journal of Food And Nutrition
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    • v.30 no.5
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    • pp.900-907
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    • 2017
  • This study was performed to investigate the body fat-lowering effect of garlic powder in peroxisome proliferator-activated receptor ${\gamma}$ coactivator-$1{\alpha}$(PGC-$1{\alpha}$)-luciferase transgenic mice (TG). In this study, we generated transgenic mice with a PGC-$1{\alpha}$ promoter (-970/+412 bp) containing luciferase as a reporter gene. Mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (CON), or high-fat diets supplemented with 2% (GP2) or 5% (GP5) garlic powder for an additional 8 weeks. Dietary garlic powder reduced the body weight in the GP2 and GP5 groups, compared to the CON group. Furthermore, garlic supplementation significantly decreased the plasma levels of triglycerides, total cholesterol, and leptin in the GP5 group, compared to the CON group. Specifically, luciferase activity in liver, white adipose tissue (WAT), and brown adipose tissue (BAT) was increased by garlic supplementation in a dose-dependent manner. These results suggest that the body fat-lowering effect of garlic powder might be related to PGC-$1{\alpha}$ by the increase in luciferase activity in liver, WAT, and BAT. Furthermore, transgenic mice might be useful for evaluating the body fat-lowering effect of various health functional foods.

The Optimal Tracking Error of Active Stock Fund by Smart Beta Strategy (스마트 베타 전략에 따른 액티브 주식형 펀드의 최적 추적오차)

  • Jae-Hyun Lee
    • Asia-Pacific Journal of Business
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    • v.13 no.4
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    • pp.163-175
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    • 2022
  • Purpose - This study introduces a methodology for finding the optimal tracking error of active stock funds. Tracking error is commonly used in risk budgeting techniques as a concept of cost for alpha creation. Design/methodology/approach - This study uses a post-optimal smart beta portfolio that maximizes alpha under the given tracking error constraint. Findings - As a result of the analysis, the smart beta strategy that maximized alpha under the constraint of 0.15% daily tracking error shows the highest IR. This means the maximum theoretically achievable efficiency. In this regard, a fixed-effect panel regression analysis is conducted to evaluate the active efficiency of domestic stock funds. In addition to control variables based on previous studies, the effect of tracking error on alpha is analyzed. The alpha used in this model is calculated using the smart beta portfolio according to the size of the constraint of the tracking error as a benchmark. Contrary to theoretical estimates, in Korea, the alpha performance is maximized under a daily tracking error of 0.1%. This indicates that the active efficiency of domestic equity funds is lower than the theoretical maximum. Research implications or Originality - Based on this study, it is expected that it can be used for active risk management of pension funds and performance evaluation of active strategies.

Citrus unshiu Water Extract Inhibits Trypsin-induced $TNF-{\alpha}$ and Tryptase Productions by Blocking the ERK Phosphorylation and Trypsin Activity

  • Kang, Ok-Hwa;Kim, Dae-Ki;Lee, Young-Mi
    • Natural Product Sciences
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    • v.10 no.5
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    • pp.211-216
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    • 2004
  • Citrus unshiu (Rutaceae) has long been known as an anti-inflammatory and anti-allergic agent. In the present study, the inhibitory effect of CUWE (Citus unshiu water extract) on the production of $TNF-{\alpha}$ and tryptase was examined. In addition, a possible mechanism for the inhibition of trypsin-stimulated human leukemic mast cell-1 (HMC- 1 ) activation was determined. To do so, $TNF-{\alpha}$ production from the HMC-1 cells that were stimulated by trypsin (100 nM) in the presence or absence of CUWE $(10,\;100,\;and\;100\;{\mu}g/ml)$ was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-PCR. The tryptase production was evaluated by reverse transcription-PCR. Extracellular signal-regulated kinase (ERK) activation was analyzed by Western blot. Trypsin activity was measured by using Bz-DL-Arg-p-nitroanilide (BAPNA) as substrate. Results showed that the CUWE inhibited production of both $TNF-{\alpha}$ and tryptase from the trypsin-stimulated HMC-1 in a dose-dependent manner. The CUWE a1so inhibited the ERK phosphorylation and trysin activity. These results indicate that the CUWE had an inhibitory effect on $TNF-{\alpha}$ and the tryptase productions by blocking the ERK phosphorylation and trypsin activity.

Effect of Dimethipin on the ${\alpha}-amylase$ Induction in Barley Seeds (보리종자에서 ${\alpha}-amylase$ 유도에 미치는 Dimethipin의 영향)

  • 전방욱
    • Journal of Plant Biology
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    • v.34 no.2
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    • pp.159-163
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    • 1991
  • The effect of dimethipin, one of the synthesized plant growth regulators, on the gibberellic acid-induced a-amylase activity in the barley de-embryonated seed system was investigated in order to elucidate the possible action mechanism of dimethipin. Dimethipin markedly inhibited the increase of mRNA and protein content, and a-amylase activity induced by gibberellic acid. The inhibitory effects were gradually decreased as the time interval between gibberellic acid treatment and dimethipin addition was made larger. Dimethipin inhibited the increase of mRNA content when added within 18 h from gibberellic acid treatment; however, it inhibited the increase of soluble protein content and a-amylase activity even added after 18 h from the treatment. These results suggest the possibility that dimethipin inhibit both mRNA synthesis and a-amylase protein synthesis.thesis.

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$\alpha$-Glucosidase Inhibition by Culture Broth of Streptomyces sp. NS15 (Streptomyces sp. NS15 배양액에 의한 $\alpha$-Glucosidase 저해)

  • 백남수;김영만
    • The Korean Journal of Food And Nutrition
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    • v.11 no.6
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    • pp.640-646
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    • 1998
  • For the production of nonprotein $\alpha$-glucosidase inhibitor from the Streptomyces sp. NS15 strain, effects of initial optimum pH, nitrogen sources, carbon sources, cationic metal ions, agitation speed and aeration rate were investigated. Initial optimum pH of medium was 7.0. The most effective nitrogen and carbon sources were soybean meal 2.0%(w/v) and glucose 1.6%(w/v), respectively. The cationic metal ins had no stimulating effect on inhibitory activity of $\alpha$-glucosidase except Fe2+. Agitation speed and aeration rate were effective at 400rpm and 1vvm, respectively. In the jar-fermenter cultivation for 4 days under optimal culture conditions, the culture broth showed the inhibitory acitivity of 3,200units/ml, which is 25 times higher than that of basic medium (CYM) for porcine intestinal $\alpha$-glucosidase. The inhibitory activity of $\alpha$-glucosidase reached about 3,200units/ml after 4 days of cultivation and decreased gradually for a further two days.

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Contact and Electrical Characteristics of $\alpha$-67 Thin-Film for the fabrication of organic Thin-Film Transistor (유기 TFT 재작을 위한 $\alpha$&$-67 박막의 접촉 및 전기적 특성)

  • 오세운;김대엽;최종선;박미경;김영관;신동명
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.313-316
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    • 1998
  • Conjugated oligomers have been already used as active layers in field effect transistors, photodiodes and electroluminescent devices. Particularly thiophene oligomers such $\alpha$ -sexithiophene($\alpha$-6T) attract great interest for its prospective app1ications in large-area flexible displays. In this study, we investigated the contact properties between the organic semiconductor $\alpha$-6T and metals such as Au(Gold), Ag(Silver), Cr(Chromium), Al(Aluminum), Cr(Chromium). Using the Transmission Line Model(TLM) method, specific contact resistances of the metal lines in contact with the $\alpha$-6T were determined. From the current-voltage characteristics, electrical conductivity of the $\alpha$-6T films is found.

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Effect of paternal folate deficiency on placental folate content and folate receptor ${\alpha}$ expression in rats

  • Kim, Hye-Won;Choi, Yun-Jung;Kim, Ki-Nam;Tamura, Tsunenobu;Chang, Nam-Soo
    • Nutrition Research and Practice
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    • v.5 no.2
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    • pp.112-116
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    • 2011
  • We investigated the effect of paternal folate status on folate content and expression of the folate transporter folate receptor ${\alpha}$ ($FR{\alpha}$) in rat placental tissues. Rats were mated after males were fed a diet containing 0 mg of folic acid/kg of diet (paternal folate-deficient, PD) or 8 mg folic acid/kg of diet (paternal folate-supplemented, PS) for 4 weeks. At 20 days of gestation, the litter size, placental weight, and fetal weight were measured, and placental folate content (n=8/group) and expression of $FR{\alpha}$ (n=10/group) were analyzed by microbiological assay and Western blot analysis, respectively. Although there was no difference observed in litter size or fetal weight, but significant reduction (10%) in the weight of the placenta was observed in the PD group compared to that in the PS group. In the PD group, placental folate content was significantly lower (by 35%), whereas $FR{\alpha}$ expression was higher (by 130%) compared to the PS group. Our results suggest that paternal folate status plays a critical role in regulating placental folate metabolism and transport.

Inhibitory Effects of B-HT 920 on Gastric Acid Secretion Induced by Vagal Stimulation in Rat

  • Hong, Sung-Cheul;Park, Mi-Sun;Chung, Joon-Ki;Kang, Maeng-Hee;Choi, Su-Kyung;Kim, Myung-Woo
    • Archives of Pharmacal Research
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    • v.12 no.4
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    • pp.243-248
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    • 1989
  • Effects of B-HT 920 on the vagally stimulated gastric acid secretion were studied in anesthetized and gastric fistula rats. When the gastric acid secretion was increased by stimulation of the vagus nerve, B-HT 920 was partially attenuated by prazosin, $\alpha_1-$adrenoceptor antagonist and virtually abolished by yohimbine, $\alpha_2-$adrenoceptor antagonist. On the other hand, when the gastric acid secretion was increased by the infusion of bethanechol, a muscarinic parasympathetic stimulant, B-HT 920 had no effect on the bethanechol-induced gastric acid secretion. These results suggest that B-HT 920 inhibits vagally induced gastric acid secretion by activation of presynaptic $\alpha-$adrenoceptors located on the vagally stimulated pathways in the gastric wall and this effect of B-HT 920 is more related to $\alpha_2-$adrenoceptors than $\alpha_1-$adrenoceptors.

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Hypoglycemic Effect of the Methanol Extract of Soybean Sprout in Streptozotocin-Induced Diabetic Rats (Streptozotocin 유발 당뇨쥐에 있어서 콩나물 메탄올 추출물의 헐당강하효과)

  • 김정인;강민정;배세연
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.6
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    • pp.921-925
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    • 2003
  • To control blood glucose level as close to normal is the major goal of treatment of diabetes mellitus. $\alpha$-glucosidase is the enzyme to digest dietary carbohydrate and inhibition of $\alpha$-glucosidase could suppress postprandial hyperglycemia. The methanol extract of soybean sprout was tested for the inhibitory activities against $\alpha$-glucosidase in vitro. Soybean sprout extract inhibited yeast $\alpha$-glucosidase activity by 24.5% at the concentration of 5 mg/mL. The methanol extract of soybean sprout was subsequently subjected to sequential fractionation with hexane, ethyl acetate, butanol and water. Among the fractions tested ethyl acetate-soluble fraction showed relatively strong inhibition against $\alpha$-glucosidase by 36.3% at the concentration of 5 mg/mL. Acarbose, standard $\alpha$-glucosidase inhibitor, inhibited $\alpha$-glucosidase activity by 40.1%. The ability of soybean sprout extract to lower postprandial glucose was studied in streptozotocin-induced diabetic rats. Starch solution (1 g/kg) with and without the methanol extract of soybean sprout (500 mg/kg) was administered to diabetic rats after an overnight-fast by gastric intubation. A single oral dose of soybean sprout extract inhibited the increase in blood glucose levels significantly at 60, 90, 120, 180 min (p<0.05) and decreased incremental response areas under the glycemic response curve significantly (p<0.05). These results suggest that soybean sprout might exert hypoglycemic effect by inhibiting $\alpha$-glucosidase activity.