• 약학회지
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• 제43권2호
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• pp.198-207
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• 1999

The aim of the present investigation was to examine whether YH439, a hepatoprotective agent, exerts protective effect against hepatotoxicity and reduces the production of cytokines and NO in lipopolysaccharide (LPS)-primed rats with carbon tetrachloride ($CCl_4$). Administration of LPS following a single dose of CCl4 injection resulted in remarkable elevations of the serum $TNF{\alpha},{\;}IL-l{\beta$ and IL-6 level. The serum NO level was moderately elevated and severe liver damage was evidenced by increases in serum alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) activities. YH439 decreased the levels of TNF, $IL-l{\beta}$, IL-6, ALT, SDH as well as NO in the serum elevated by CCl4+LPS in a dose-dependent manner. Inducible nitric oxide synthase (iNOS) level was decreased in the liver of rats treated with YH439. The increased iNOS activity induced by LPS and $interferon-{\gamma}$ was significantly decreased in RAW 264.7 cells by YH439 treatment. YH439 increased the GSH level decreased by $CCl_4+LPS$ and suppressed the ratio of GSSG/GSH. The reduction of hepatotoxicity by YH439 may associated with the decrease in the production of cytokines as well as suppression of iNOS protein in conjunction with an increase in the GSH level.

• 전기학회논문지P
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• 제58권4호
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• pp.490-494
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• 2009

In this paper, how the temperature of a varistor changes when $10/350{\mu}s$ surge currents and/or DC leakage currents are applied on it, respectively, are investigated. The temperature change in varistor is related with injection energy and leakage current. which is the integration of power in time. By the surge current test, we found that the temperature jump is proportional to the level of surge current with slant 52.535 and has no relation with the ambient temperature. And by the DC leakage current test, the difference in temperatures between varistor and ambient is proportional to the magnitude of leakage current. The slope of measured line(the temperature difference vs. the leakage current) shows alteration around $100{\mu}A$. The varistors can not be used more than $100{\mu}A$ region any more. From the above experimental results, we can conclude that data of the surge current test and also those of DC leakage current test can predict the performance of varistors of which the surge protective devices are made.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.444-450
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• 2003

In order to develop an effective means to treat P. aeruginosa infections, we have purified P. aeruginosa outer membrane proteins (OMPs)-specific human IgG antibody. In this study, we investigated the protective activity of the purified anti-OMPs IgC against P. aeruginosa infection in a rabbit endophthalmitis model. Rabbits were inoculated by an intravitreal injection with P. aeruginosa, and treated with a single dose of 1 mg anti-P. aeruginosa OMPs IgG. All the control rabbits predominantly developed edematous responses and opacity in the eyes, but the rabbits treated with the antibody showed only very limited degree of edema. Aliquots of the vitreous humor were extracted and analyzed for the number of viable bacteria and endotoxin level. The results showed that the anti-OMPs IgC significantly reduced the bacterial count compared with the control group, and that the endotoxin level of the vitreous from the IgG-treated rabbits was more than 70-fold lower 6 h after the administration than the control animals. These data suggested that the anti-P. aeruginosa OMPs IgG is effective in inhibiting the bacterial growth and thereby in reducing endotoxin levels in the vitreous, warranting further development of the anti-P. aeruginosa OMPs IgG as a therapeutic means for treating Pseudomonas endophthalmitis.

• The Korean Journal of Physiology and Pharmacology
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• 제9권3호
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• pp.159-164
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• 2005

Effects of antioxidants on the established nephropathy were investigated. The experimental nephropathy was induced in rats by intravenous injection of adriamycin (2 mg/kg). Six weeks later, when proteinuria was apparent, the rats were supplemented with N-acetylcysteine (NAC, 1 g/kg/day) in drinking water for additional 6 weeks. Glomerulosclerosis score and tubulointerstitial injury index were determined by light microscopy. Expression of transforming growth factor (TGF) ${\beta}1$ and laminin ${\beta}1$ was determined in the renal cortex by reverse transcription-polymerase chain reaction, Western blotting, immunohistochemistry, and immunogold electron microscopy. The adriamycin-induced proteinuria as well as the glomerulosclerosis and tubulointerstitial injury was ameliorated by the treatment with NAC. Adriamycin increased the expression of TGF ${\beta}1$ mRNA and protein, which was ameliorated by NAC. Although the expression of laminin ${\beta}1$ mRNA was increased, adriamycin did not significantly alter that of its protein. These results indicate that antioxidants ameliorate the established nephropathy in association with normalization of overexpressed TGF ${\beta}1$.

• Archives of Pharmacal Research
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• 제28권1호
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• pp.81-86
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• 2005

The hepatoprotective effects of chalcone derivatives were evaluated in D-galactosamine/lipopolysaccharide (D-GaIN/LPS)-induced fulminant hepatic failure in mouse. Thirteen chalcone derivatives were synthesized for study and their hepatoprotective effects were evaluated by assessing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in serum. Chalcone preparations were injected into mice at 12 hand 1 h before intraperitoneal injection of D-GaIN/LPS. After abdominal administration, changes in AST and ALT between the control and treated groups were observed. Ten of the synthesized chalcone derivatives exhibited inhibitory effects on D-GaIN/LPS-induced levels of AST and ALT in mice. Compounds 2, 3, 8, 9, and 12 markedly reduced serum AST and ALT at 8 h, inhibited hepatocyte necrosis and showed significant hepatoprotective activities. The activity of compound 3 was compared with the bifendate (DDB) through oral administration. Compound 3 showed much higher inhibitory effects than bifendate for decreasing AST and ALT activity. The results indicate that compound 3 has strong hepatoprotective activity through suppression of tumor necrosis factor­alpha (TNF-alpha) preduction, reduction of the histological change in the liver, and attenuated of hepatocyte apoptosis confirmed by DNA fragmentation assay.

• 한국인터넷방송통신학회논문지
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• 제10권4호
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• pp.121-126
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• 2010

HEMP분야에 대한 연구는 1950년대 이후 미국을 중심으로 핵을 보유한 국가에 의해 주로 국가방위를 목적으로 수천 건의 연구가 집중적으로 이루어졌다. HEMP 방호설비의 핵심은 차폐, 필터링, 접지, 과전압 보호로 구성된다. 이중에서 투자비용이 가장 높은 차폐실 설계에 있어 기존에 나와 있는 이론식을 적용하여 시뮬레이션을 하면 특정 주파수 대역을 제외하고 실제 측정값과 전혀 맞지 않는 모순이 있었다. 본 논문에서는 HEMP 방호용 차폐실의 최적설계를 위해 기존 이론식을 개선하여 실제 측정값과 넓은 주파수 범위에서 잘 일치할 수 있는 이론을 제시하고, 각각의 재료정수에 따라 설계전에 충분하게 시뮬레이션을 거쳐 경제적이고 효과적으로 HEMP 방호용 차폐실을 건설할 수 있도록 하는 시뮬레이터를 개발하였다.

• 대한한의학회지
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• 제27권1호
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• pp.47-56
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• 2006

The present study was carried out to investigate the preventive effect of Epimedii Herba combined Samgijiwhang-Tang(SJTE) on streptozotocin(STZ)-induced diabetic nephropathy. SJTE was given to rats with oral administration. The experimental animals were divided into normal group of rats, control group of STZ-induced diabetic rats, and sample group with SJTE administration. Experimental diabetic nephropathy was induced by the injection of STZ(60mg/kg) to the rat via the peritoneum. The effect of SJTE on STZ-induced diabetic nephropathy was observed by measuring the serum level of insulin, glucose, creatinine and BUN. Urine secretion of albumin for 24 hours and urine level of glucose measures too. Anti-oxidative stress of STZ administration in living body was estimated by measuring lipid peroxide in cortex of kidneys. STZ induced increase of serum glucose. creatinine, urine albumin secretion and renal cortical lipid peroxidation were lowered by SJTE administration. In conclusion, the SJTE treatment showed protective effect on rat diabolic nephropathy model, and action mechanism of the effect was thought to be concerned with internal glucose metabolism.

• 대한한의학회지
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• 제27권3호
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• pp.77-87
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• 2006

Objectives: The present study was carried out to investigate the preventive effects of Samgijiwhang-Tang(SJT) on streptozotocin(STZ)-induced diabetic nephropathy. Methods: SIT was given to rats through oral administration. The experimental animals were divided into a normal group of rats, a control group of STZ-induced diabetic rats, and a sample group with SIT administration. Rehmanniae Radix Preparat is combined in the original prescription of SIT, but in this experiment, Rehmanniae Radix was combined instead of Rehmanniae Radix Preparat to compare the effects of anti-diabetic nephropathy. Experimental diabetic nephropathy was induced by the injection of STZ(60mg/kg) in the rat via the peritoneum. The effect of SIT on STZ-induced diabetic nephropathy was observed by measuring the serum level of creatinine and BUN, in addition to urine secretion of albumin for 24 hours and the level of glucose found in the urine. Anti-oxidative stress of SIT administration in a living body was estimated by measuring lipid peroxide and GSH content in the cortex of kidneys. Results: STZ induced an increase of serum creatinine, urine glucose and renal cortical lipid peroxidation was lowered by Rehmanniae Radix Preparat combined SIT administration. Conclusions: The SIT treatment showed a protective effect on the rat diabetic nephropathy model, and action mechanism of the effect was thought to be concerned with anti-oxidative stress.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.659-664
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• 2016

Lindera obtusiloba has been used in traditional herbal medicine for the treatment of blood stasis and inflammation. The leaves of Lindera obtusiloba have been reported to exhibit various physiological activities. However, there is little information available on their antiplatelet and antithrombotic activities. Thus, the present study aimed to evaluate the effect of Lindera obtusiloba leaf extract (LLE) on platelet activities, coagulation and thromboembolism. In a platelet aggregation study, LLE significantly inhibited various agonist-induced platelet aggregations in vitro and ex vivo. Furthermore, LLE significantly inhibited collagen-induced thromboxane A2 (TXA2) production in rat platelets. In addition, oral administration of LLE was protective in a mouse model of pulmonary thromboembolism induced by intravenous injection of a mixture of collagen and epinephrine. Interestingly, LLE did not significantly alter prothrombin time (PT) and activated partial thromboplastin time (aPTT). This study indicates that the antithrombotic effects of LLE might be due to its antiplatelet activities rather than anticoagulation. Taken together, these results suggest that LLE may be a candidate preventive and therapeutic agent in cardiovascular diseases associated with platelet hyperactivity.

• 한국어병학회지
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• 제27권1호
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• pp.11-16
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• 2014

The resistance against white spot syndrome virus (WSSV) infection in wild marine crab Gaetice depressus by the immunization of a recombinant glutathione-S-transferase (GST) fused VP28 protein (GST-VP28) was evaluated. The cumulative mortalities of GST-VP28 injected groups were lower than those of the control groups at 10 days of post-challenge, and the time to death of 50% crab ($TD_{50}$) was delayed by the immunization using GST-VP28. The group boosted with GST-VP28 after 2 weeks of primary immunization clearly showed longer $TD_{50}$ than non-boosted group against challenge with WSSV. This result suggests that boosting with the antigen protein elicit stronger immune responses similar to adaptive immune responses of vertebrates. However, the short $TD_{50}$ was observed in the group challenged at 3 weeks post boosting comparing to the group challenged at 1 week post boosting. This suggests that the protective strength of immunization decreased by the time.