• Title/Summary/Keyword: HMA

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Reduced Protein Denaturation in Thermotolerant Cells by Elevated Levels of HSP70 (열내성이 유도된 세포에서 HSP70 단백질 증가에 의한 단백질 변성 감소)

  • Han, Mi-Young;Park, Young-Mee
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.433-444
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    • 1996
  • We describe a novel approach to evaluate quantitatively the amounts of denatured proteins in cells upon heat exposure. A thiol compound, diamide [azodicarboxylic acid bis (dimethylamide)] causes protein cross-linking with exposed sulfyhydryl residues of denatured proteins. Since denatured proteins expose normally well-hidden sulfhydryl groups, these will be preferentially cross-linked by diamide. Thus diamide acts to 'trap' denatured proteins. We observed that protein aggregates (high molecular weight protein aggregates, HMA) appeared on SDS-polyacrylamide gels run under non-reducing conditions and that the amount of HMA can be quantified by scanning the gels using a gas flow counter. Heating cells followed by a fixed dose of diamide exposure resulted in HMA increases in a heat-dose dependent manner, demonstrating that the quantitation of HMA could serve as a measure of heat-denatured proteins. We compared thermotolerant and nontolerant cells and found decreased HMA in tolerant cells upon heat treatment. As an attempt to examine the kinetics of protein renaturation (or 'repair'), we measured the amounts of aggregates formed by the addition of diamide at various times after heat shock. Such experiments demonstrate an equally rapid disappearance of HMA in previously unheated and in thermotolerant cells. Levels of HMA in tolerant cells increased significantly after electroporation of HSP70 specific mAbs, suggesting an involvement of HSP70 in reducing HMA levels in thermotolerant cells upon heat exposure. Immunoprecipitation studies using anti-HSP70 antibody indicated an association of HSP70 with heat-denatured proteins. Our results suggest that heat induces protein denaturation, and that elevated level of HSP70 present in thermotolerant cells protects them by reducing the level of protein denaturation rather than by facilitating the 'repair' (or degradation) process.

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Immunomodulatory Function of Murine NK Cell Activity by Alginate

  • Son Eun-Wha;Yang Kwang-Hee;Rhee Dong-Kwon;Pyo Suhkneung
    • Archives of Pharmacal Research
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    • v.28 no.11
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    • pp.1282-1286
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    • 2005
  • The in vivo immunomodulatory function of the activity of murine natural killer (NK) cells induced by high mannuronic acid-containing alginate (HMA) was examined. HMA was injected i.p at doses of 25 and 100 mg/kg. The NK activity was 3 times higher with 100 mg/kg HMA than the baseline. In addition, in vitro studies of splenocytes cultured with HMA for 20 h showed a significant increase in NK activity at E:T ratio of 100: 1; a 160$\%$ and 210$\%$ increase at 10 and 100 $\mu$g/mL, respectively. There was a six fold increase in interferon-$\gamma$ production in a postculture of splenocytes with 100 $\mu$g/mL HMA. HMA had no suppressive effects on the lymphocyte function in the presence or absence of mitogens. This suggests that HMA is useful in cancer immunotherapy.

Effect of Increased Intracellular pH by HMA on the Cytotoxicity of Combined Treatment of Hyperthermia and Chemotherapy (HMA의 세포내 산도증가가 온열과 항암화학 치료의 세포독성에 미치는 효과)

  • Hur, Won-Joo;Song, Chang-Won
    • Radiation Oncology Journal
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    • v.13 no.2
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    • pp.121-128
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    • 1995
  • Purpose: The enhanced cytotoxic effect of combined treatment of hyper-thermia and chemotherapy by increasing intracellular acidity with HMA was investigated. Materials and Methods: FSall tumor cells were injected on the hindlegs of female $C_3H$ mice. When the tumor volume reached about 200mm3, experiments were performed on the groups classified as follows: Group I :Control, Group II : Melphalan alone (2.5mg/kg, 5mg/kg, 10mg/kg, 15mg/kg), Group III : Heat alone $(42.5^{\cdot}C$ for 1 hour) Group IV : Melphalan + Heat $(42.5^{\cdot}C$ for 1 hour), Group V : HMA(10mg/kg) + Melphalan(5.0mg/kg) + Heat$(42.5^{\cdot}C$ for 1hour). Each group included 8-12 mice on each experiment HMA (3-amino-6-chloro-5-(1-homopiperidyl )-N-(diaminomethylene) -c-pyrazinecarboxamide), an analog of amiloride which increases intracellular pH(pHi) was dissolved in dimethyl sulfoxide (DMS) and injected into the tumor-bearing mice through the tail vein. 10mg/kg of HMA and each dose of melphalan were injected into peritoneum of the tumor-bearing mice 30 minutes before heating. Tumor growth delay was calculated when the tumor volme reached at $1500mm^3$ Excision assay was performed on each group and repeated 2-4 times. Results : Tumor growth delay of each experimental groups at $1500mm^3$ were 9, 10, 13 and 19 days respectively. In vivo-in vitro excision assay using FSall tumor cells, the cytotoxicity of each experimental groups was $1.2{\times}10^7,\;1{\times}10^7,\;6{\times}10^6,\;1.7{\times}10^6\;and\;1{\times}10^5$ clonogenic cells/gm respectively When HMA was added to the combined treatment of heat and .chemotherapy, the tumor growth was delayed more than combined treatment without HMA i.e., 6 days tumor growth delay at $1500mm^3$ of tumor volume. Conclusion: The combined effect of cytotoxicity by heat and chemotherapy can be much more enhanced by HMA.

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HMA(Hierarchical Multi Agent) for Operation of Distribution Power System (HMA(Hierarchical Multi Agent)방법을 이용한 배전계통 운영 시스템)

  • Kim, D.H.;Kwak, J.W.;Lee, S.S.;Lee, S.K.;Yoon, Y.T.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.503-504
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    • 2007
  • 배전 계통은 기본적으로 방사상 구조를 가지고 있지만 향후 분산 전원의 출현 등으로 계통 운영의 복잡성이 증대될 것이다. 따라서 계통의 재구성이나 복구와 관련된 운영 전반에 관한 판단의 정확성과 신속성을 요구하게 된다. 본 논문에서는 HMA(Hierarchical Multi Agent) 방법을 이용하여 배전 계통의 운영에 활용해 보았다. HMA 방법은 서로 다른 행동 특성을 가진 Agent들이 자신의 역할을 수행하면서 전체적인 최적해를 찾을 수 있고 적은 정보를 이용하기 때문에 사고에 대처하는 속도가 빨라질 것으로 예상된다. 본 논문에서는 배전 계통에 맞는 HMA 모델과 각 Agent들의 행동 원칙을 제안하고 활용 방안을 제시하였다.

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A Study on the Development of Hospital Management Award Programme in Korea (병원경영대상 시상제도의 설계 연구)

  • Jung, Doo-Chae;Kim, Young-Hoon;Kim, Gi-Chul;Sohn, Tae-Yong
    • Korea Journal of Hospital Management
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    • v.13 no.3
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    • pp.94-113
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    • 2008
  • The purpose of this study to develop the Hospital Management Award(HMA) programme which would be a basic information for advancing hospital industry in Korea. HMA programme in the study are designed with general census building method of researchers and with the data of professions opinion which was survey with structured questionnaire Major results of this study are as follows. First, Hospital Management Award(HMA) programme is perceived very necessary and useful for advancing hospital industry of Korea (positive response rate: 93.0%). Second, Criteria, Classification of hospitals may be the function, size and ownership of hospital. Third Evaluating area of hospital management, examining method and evaluation marking points are designed on the basis of hospital management information system. Forth, this study suggests same strategies for execution of the programme. On the basis of the study results this study suggests that Hospital Management Award(HMA) programme would rather actualized in advance by formal institute and/or association. And some in depth studies are required mainly for development of the action plan of HMA programme.

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Antiviral and Tumoricidal Activities of Alginate-Stimulated Macrophages are Mediated by Different Mechanisms

  • Son, Eun-Wha;Rhee, Dong-Kwon;Pyo, Suhk-Neung
    • Archives of Pharmacal Research
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    • v.26 no.11
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    • pp.960-966
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    • 2003
  • Macrophages play an important role in host defenses by killing tumors and virus infections and producing secretory products. High mannuronic acid (HMA) containing alginate was examined to determine the mechanisms by which HMA-activated macrophages resist infection with HSV-1 and inhibit the growth of tumor cells. The ability of macro phages to resist infection with HSV-1 or to inhibit the growth of tumor cells was assessed following treatment with HMA alginate in the presence of either antibodies to various cytokines or inhibitors/scavengers of toxic macrophage products. Only antibodies to IFN-$\alpha$/$\beta$ were able to abrogate the protective effects of HMA alginate in macrophages infected with HSV-1, suggesting that the antiviral activity induced by this immunomodulator was mediated by the production of IFN-$\beta$. In contrast, anti-TNF-$\alpha$, anti-IFN and inhibitors of nitric oxide and reactive oxygen species were all able to partially abrogate HMA-induced cytostatic activity, suggesting that multiple mechanisms are involved in macrophage cytostasis. These results indicate that the HMA-induced intrinsic antiviral and extrinsic cytotoxic activites are mediated by different mechanisms.

Variation of Flexural Strength of Warm-mix Asphalt Concretes Due to Differential Thermal Contraction at Low Temperatures (저온하에서 시차열 수축에 의한 WMA 콘크리트의 휨강도 변화)

  • Choi, Jung-Soon;Kim, Sung-Un;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.63-72
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    • 2012
  • PURPOSES : Hot-mix asphalt(HMA) concretes show a trend of strength increase at low temperature due to binder stiffness increase, but strength decrease below a ceratin low temperature. This is due to the differential thermal contraction(DTC) which is induced by a significant difference in coefficients of thermal contraction between aggregate and asphalt which is coated around the aggregate. This DTC damage is well known to occur in HMA concrete, but is not yet investigated in warm-mix asphalt(WMA) concretes. METHODS : To evaluate DTC damage on WMA in this study, the flexural strength($S_f$) of WMA concretes, which were produced at $30{\sim}40^{\circ}C$ lower temperature, was evaluated in comparison with that of HMA at -5, -15 and $-25^{\circ}C$. RESULTS : Most of WMA and HMA mixtures showed flexural strength increase down to $-15^{\circ}C$ and decrease below $-15^{\circ}C$. this type of strength reduction below $-15^{\circ}C$ can e explained as the effect of differential thermal contraction that is a consequence of the large difference in coefficients of thermal contraction between aggregate and asphalt. the property reduction of WMA is similar the result of previous works dealt with HMA mixtures. CONCLUSIONS : Even though there is some differences by materials used, the WMA concretes showed a significantly lower DTC damage than HMA concrete at low temperature at ${\alpha}$=0.05 level.

Evaluation of Fatigue Resistance of Selected Warm-mix Asphalt Concrete (준고온 아스팔트 콘크리트 피로저항성 평가)

  • Kim, Sungun;Lee, Sung-Jin;Kim, Kwang W.
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.3
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    • pp.29-38
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    • 2020
  • Since some warm-mix asphalt (WMA) concretes were known to show poorer rut resistance than the hot-mix asphalt (HMA) concretes, many studies were performed in efforts of improving its performance at high temperature. The reason is assumed to be due to the moisture remaining in aggregates dried at lower temperature. Therefore, not only the rut resistance, the crack resistance of WMA concrete was also in question. In this study, fatigue life of WMA concrete was evaluated in comparison with HMA using 3-point bending (3PB) beam test. The asphalt mixtures were prepared based on Korean mix-design guide using a 13 mm dense-graded aggregate and 6 binders; two HMA binders and four WMA binders. By 3PB fatigue test, normal (unmodified) and polymer-modified WMA concretes were evaluated in comparison with normal and polymer-modified HMA concretes at a low temperature (-5℃). The results showed that most of WMA concretes showed longer fatigue lives than HMA concretes, even though the same PG binders were used for HMA and WMA. This result indicates that the WMA concretes have stronger resistance against fatigue cracking than HMA at the low temperature, and this result is in contrast to the high-temperature performance test.

A Study for Evaluation of Hot Mixed Asphalt Mixtures with Tack-Coat Regarding High-Frequency Dynamic Resistance Performance and Bonding Property (택코트 첨가 가열아스팔트 혼합물의 고주파 동적저항 특성 및 접착성능 평가에 대한 연구)

  • Kim, Dowan;Mun, Sungho
    • International Journal of Highway Engineering
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    • v.17 no.3
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    • pp.35-47
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    • 2015
  • PURPOSES : A tack coat has been utilized to increase the bond performance between the surface layer and base course (intermediate course) at various road pavement sites. This is similarly true in other nations. Based on this connection, the objective of the present study is to evaluate the properties of hot mix asphalt (HMA) mixtures with an RSC-4 or BD-Coat and determine the application rate of the tack coat. METHODS : The HMA specimens were manufactured using superpave gyratory compaction. The HMA mixtures were composed of a 5-cm thick surface layer and a 10-cm thick base course. An impact hammer resonance test (IHRT) and a static load shear test were conducted to evaluate the performance of the HMA mixtures with a tack coat. From these tests, the dynamic moduli related to the high-frequency resistance and interlayer shear strength (ISS) of HMA could be obtained. RESULTS : The results of the dynamic moduli of HMA are discussed based on the resonance frequency (RF). To check the accuracy of the IHRT, we conducted a coherence analysis. A direct shear test using the application of a static load test was carried out to evaluate the interlayer shear strength (ISS) of HMA. CONCLUSIONS : The maximum ISS was demonstrated at an RSC-4 application rate of 462 gsm, and the maximum dynamic modulus was demonstrated at an RSC-4 application rate of 306 gsm. By averaging the results of the ISS, the maximum ISS values were obtained when a BD-Coat application rate of 602 gsm was applied.