• 제목/요약/키워드: GP

검색결과 2,199건 처리시간 0.053초

Modulation of Multidrug Resistance in Cancer by P-Glycoprotein

  • Gadhe, Changdev G.;Cho, Seung Joo
    • 통합자연과학논문집
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    • 제4권1호
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    • pp.23-30
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    • 2011
  • Multidrug resistance (MDR) is one of the main obstacles in the chemotherapy of cancer. MDR is associated with the over expression of P-glycoprotein (P-gp), resulting in increased efflux of chemotherapy from cancer cells. Inhibiting P-gp as a method to reverse MDR in cancer patients has been studied extensively, but the results have generally been disappointing. First-generation agents were limited by unacceptable toxicity, whereas second-generation agents had better tolerability but were confounded by unpredictable pharmacokinetic interactions and interactions with other transporter proteins. Third-generation inhibitors have high potency and specificity for P-gp. Furthermore, pharmacokinetic studies to date have shown no appreciable impact on drug metabolism and no clinically significant drug interactions with common chemotherapy agents. Third-generation P-gp inhibitors have shown promise in clinical trials. The continued development of these agents may establish the true therapeutic potential of P-gp-mediated MDR reversal.

Investigation of Binding Modes of the Verapamil and Curcumin into Human P-glycoprotein (P-gp)

  • Gadhe, Changdev G.;Cho, Seung Joo
    • 통합자연과학논문집
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    • 제6권4호
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    • pp.205-210
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    • 2013
  • Human P-gp is a protein responsible for the multidrug resistance (MDR) and causes failure of cancer chemotherapy. Till date no X-ray crystal structure is reported for this membrane protein, which hampers active research in the field. We performed homology modeling to develop three dimensional (3D) model of P-gp, and docking studies of the verapamil and curcumin have been performed to gain insight into the interaction mechanism between inhibitors and P-gp. It was identified that the inhibitors docked into the upper part of P-gp and interacted through the hydrophobic interactions.

Electrochemical Dopamine Sensors Based on Graphene

  • Rahman, Md. Mahbubur;Lee, Jae-Joon
    • Journal of Electrochemical Science and Technology
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    • 제10권2호
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    • pp.185-195
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    • 2019
  • The large surface area and the high electrical conductivity of graphene (GP) allow it to act as an "electron wire" between the redox center of biomolecules and an electrode surface. The faster electron transfer kinetics and excellent catalytic activity of GP facilitate the accurate and selective electrochemical detection of biomolecules. This mini-review provides an overview of the recent developments and progress of GP, functionalized or doped GP, and GP-composites based sensors for the selective and interference-free detection of dopamine (DA). The electrochemical principles and future perspective and challenges of DA sensors were also discussed based on GP.

소나무와 상수리나무림의 임내우 물수지 특성 (Characteristics of Water Budget on Throughfall and Stemflow in Pinus densiflora and Quercus acutissima)

  • 이헌호;박재철
    • 한국환경생태학회지
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    • 제12권3호
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    • pp.259-270
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    • 1998
  • 본 연구는 산지의 수자원보전량 평가용 수문유출모형의 개발을 위한 중요한 기초연구로서 우리나라 주요 수종인 소나무와 상수리나무에 대한 수간류 및 수관통과우의 물수지식과 수문학적 특성을 밝히고자 수행하였다. 영남대학교 자연자원대학 부속 용성연습림과 영남대학교 교내 야산에 각각 수관통과우 및 수간류 관측용 야외 실험지를 설치하고, 1995년 9월에서 1998년 6월까지 약 2년 10개월 사이에 이 지역에 내린 다수의 단위강우에 대한 두 수종의 임내우 수량배분을 조사하였다. 그 결과 임외의 단위강우에 응답하는 두 수종의 수문학적 특성과 임내우 물수지식을 요약하면 다음과 같다. 1. 소나무에 있어서 수관통과우와 수간류의 총량은 각각 임외우의 73.8%와 0.8%이였으며 상수리나무는 각각 임외우의 76.9%와 3.8%로 관측되었다. 2. 소나무에 있어서 임외우(Gp)에 대한 수간류(S$_{f}$)와 수관통과우(T$_{f}$)의 회귀식은 각각 S$_{f}$ = 0.01GP -2.05 ($r^2$=0.54) T$_{f}$ = 0.79Gp - 26.04 ($r^2$=0.92)로, 임내우(N$_{r}$)와는 N$_{r}$ = 0.81Gp - 28.09 (r2=0.92)로 추정하였다. 이와 같이 소나무에 있어서 수간류와 수관통과우는 임외우의 양에 정비례하여 증가하였다. 3. 상수리나무에 있어서 임외우(Gp)에 대한 수간류(S$_{f}$)와 수관통과우(T$_{f}$)의 회귀식은 각각 S$_{f}$ = 0.03Gp + 12.25 ($r^2$=0.74) T$_{f}$ = 0.78Gp + 19.75 ($r^2$=0.96)로, 임내우(N$_{r}$)와는 N$_{r}$ = 0.81Gp + 31.99 ($r^2$=0.96)로 구해졌는데 소나무보다 상수리나무에 있어서 수간류와 수관통과우의 증가폭이 더 큰 것으로 나타났다. 4. 수간류 및 수관통과우와 그 영향인자로 평가된 수관투영면적(CA). 흉고직경(DBH), 임외우량(Gp)과의 내부상관분석을 한 결과, 소나무 수간류에는 임외우>수관투영면적>흉고직경의 순으로, 상수리나무 수간류에는 임외우>흉고직경>수관투영면적의 순으로 상관계수 값이 높았다. 그리고 소나무와 상수리나무의 수관통과우는 임외우>수관투영면적>흉고직경의 순으로 상관계수 값이 높았다.상관계수 값이 높았다.

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Global Positioning System(GPS) : 원리와 응용

  • 지규인;이영재
    • 제어로봇시스템학회지
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    • 제2권2호
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    • pp.10-18
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    • 1996
  • 이 글에서는 현재 그 응용범위가 확장되어감에 따라 관심이 고조되고 있는 GPS의 원리와 응용에 대해 간단히 요약해 소개하고자 한다. 제2절에서는 GPS를 이용한 위치 측정의 원리를, 제3절에서는 GPS의 응용과 앞으로의 전망에 대해 기술하려고 한다.

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시계열 섭동 모델링 알고리즘 : 운전자 프로그래밍과 양자역학 섭동이론의 통합 (Time Series Perturbation Modeling Algorithm : Combination of Genetic Programming and Quantum Mechanical Perturbation Theory)

  • 이금용
    • 정보처리학회논문지B
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    • 제9B권3호
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    • pp.277-286
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    • 2002
  • 양자역학 섭동이론과 유전자프로그래밍(GP) 기법을 접목시킴으로써 실세계(Real-world)에서 발생하는 카오스 시계열에 대하여 수학모델을 구축, 예측하기 위한 새로운 알고리즘을 개발하였다. 시계열 분석과 양자역학 파동방정식의 해를 구하는 섭동이론과의 절차적 유사성을 논하고, 이것을 GP로 구현하는 전형적 접근방안을 제시한다. 함수집합(Function Set)으로서 직교함수(Orthogonal Functions)를 이용하고 병렬 집단을 사용하는 GP를 이용하여 원 시계열에 대한 초기 수학모델을 구하고, 원 시계열 데이터로부터 모델의 평가값을 뺀 나머지로 구성되는 잔여 시계열에 대하여 다시 GP를 적용하는 과정을 일정한 종료조건이 충족될 때가지 반복함으로써 실세계 카오스 시계열에 대한 정확성 높은 수학모델을 구축하는데 성공하였다. 타 방법론과의 비교와 향후 해결과제에 대하여도 소개한다.

Expression of P-glycoprotein is Positively Correlated with p53 in Human Papilloma Virus Induced Squamous Intraepithelial Lesions of Uterine Cervix: Poor Prognosis Association

  • Singh, Madhulika;Singh, Uma;Mathur, Neeraj;Shukla, Yogeshwer
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.6039-6045
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    • 2012
  • This study was conducted to assess the predictive value of p-glycoprotein (p-gp) and p53 immunoexpression in human papillomavirus (HPV) infected cases of cervical dysplasia. Expression of both p-gp and p53 proteins was detected in cervical smears from 177 squamous intraepithelial lesions (SIL) cases along with 183 "atypical squamous cells of unknown significance" (ASCUS) and 150 normal cases. HPV 16 and 18 infection was detected by polymerase chain reaction using type-specific primers for HPV sub-types. There were no significant detectable p53 and p-gp expression in the normal cervix smears (p>0.05). In the ASCUS group 10 cases were positive for both p53 and p-gp immunoreactivity. In cervical dysplasia cases, p53 was positive in 86 (48.58%) while p-gp was positive in 93 (52.54%) and the two markers showed a highly significant correlation (r=0.92, p<0.001). Expression of p53 and p-gp was associated with grade of SIL (p<0.001). A positive correlation between the presence of HPV and expression of proteins p53 and p-gp in smears of patients with cervical lesions was also noted (p<0.001). Thus, p53 and p-gp immunostaining in cervical smears may act as an auxiliary biomarker for detection of HPV-associated cervical lesions. Additionally, a significant positive correlation between ascending grades of SIL and labeling indices of markers suggests that p53 and p-gp can be used as an adjunct to cytomorphological interpretation of conventional cervical Pap smears.

Characterization and Epitope Mapping of KI-41, a Murine Monoclonal Antibody Specific for the gp41 Envelope Protein of the Human Immunodeficiency Virus-1

  • Shin, Song-Yub;Park, Jung-Hyun;Jang, So-Youn;Lee, Myung-Kyu;Hahm, Kyung-Soo
    • BMB Reports
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    • 제31권1호
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    • pp.58-63
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    • 1998
  • In this study, a mouse monoclonal antibody (mAb) against gp41(584-618), the immunodominant epitope protein, was generated. For this purpose, BALB/c mice were immunized with double branched multiple antigenic peptides derived from the HIV-1 gp41(584-618) sequence, and antibody-secreting hybridoma were produced by fusion of mice splenocytes with SP2/0 myeloma cells. One clone producing an antigen specific mAb, termed KI-41(isotype IgG1) was identified, whose specific reactivity against gp41(584-618) could be confirmed by ELISA and Western blot analysis. Epitope mapping revealed the recognition site of the mAb KI-41 to be located around the sequence RILAVERYLKDQQLLG, which comprises the N-terminal region within the immunized gp41(584-618) peptied. Since this mAb recognizes this specific epitope within the HIV-1 gp41 without any cross-reactivity to other immunodominant regions in the HIV-2 gp35, KI-41 will provide some alternative possibilities in further applications such as the development of indirect or competitive ELISA for specific antibody detection in HIV-1 infection or for other basic researches regarding the role and function of HIV-1 gp41.

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Replacing groundnut cake with gluten meals of rice and maize in diets for growing Sahiwal cattle

  • Malik, Tariq A.;Thakur, S.S.;Mahesh, M.S.;Yogi, R.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권10호
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    • pp.1410-1415
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    • 2017
  • Objective: This experiment investigated the effect of isonitrogenous replacement of groundnut cake (GNC) by rice gluten meal (RGM) and maize gluten meal (MGM) at 75% level on nutrient intake, apparent digestibility, growth performance and related blood constituents in growing Sahiwal cattle. Methods: Eighteen Sahiwal calves were divided into three groups, based on average body weight (87.24 kg) and age (6 to 12 mo), and treatments were assigned to the different groups randomly. The first group (GP-I) was kept as control and received GNC-based concentrate mixture. In second (GP-II) and third (GP-III) groups, 750 g/kg nitrogen (N) of GNC was substituted by RGM and MGM respectively, with similar forage:concentrate ratio (56:44). Results: The 90 days of experimental feeding revealed that intake of dry matter, crude protein and digestibility coefficients for all nutrients did not differ among groups. Furthermore, although N balance was greater ($p{\leq}0.05$) for GP-III than GP-I and GP-II, average daily gain was similar between GP-I and GP-II but greater ($p{\leq}0.05$) for GP-III. In addition, feed efficiency and related haematological variables did not differ due to treatments. Conclusion: Nutritional worth of GNC and RGM was highly comparable in terms of intake, digestibility and growth in growing calves. However, MGM was found to be more efficacious in improving growth rate than RGM at 75% replacement level of GNC protein.

곡류.야채식이의 영양소 보완이 흰쥐의 성장에 미치는 영향 (I) - 단백질 대사를 중심으로 - (Effects of Nutritional Supplementation of Cereal-Vegetable Diet on the Growth of Rats (I) - Especially on Protein Metabolism -)

  • 부미정
    • 대한가정학회지
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    • 제20권2호
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    • pp.91-102
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    • 1982
  • This study was designed to find out the nutritional defect of general Korean diet and the effective way of nutritional supplementation. Seventy weanling Sprague-Dawley male rats weighing 51.8$\pm$0.9g were blocked into ten groups and fed ten different diets ad libitum for eight weeks: Standard groups(st gp) was given 72% sugar-20% casein diet: Cereal-vegetable group(c-v gp) was fed cereal-vegetable diet(c-v diet) composed of rice, barley, soybean, spinach and cabbage: the other eight groups were fed c-v diets supplemented with casein, vitamin $B_{2}$, calcium, vitamin A, vitamin B2 and A, vitamin A and calcium, vitamin $B_{2}$ and calcium, vitamin A and $B_{2}$and calcium, respectively, on the basis of each nutrients content of standard diet. The results were as follows: 1. Food intakes and body weight gains in all the experimental groups were significantly lower than st gp. Among experimental groups, casein gp and vit B2 gp tended to gain more body weights than c-v gp. 2. Through all the experimental period, F.E.R., pp.E.R., and NDPcal% did nod show significant differences among all the experimental groups and st gp. 3. The weights of liver, kidney, and gastrocnemius were significantly lower in all the experimental groups as compared with st gp. But brain and sex organ weights did not show differences among all the groups. 4. Nitrogen contents of total carcass, liver, and gastrocnemius in all the experimental groups tended to be increased as compared with st gp, and among experimental groups, they tended to be increased by casein supplementation and decreased by ca supplementation. 5. Apparent nitrogen digestibility, urinary and fecal nitrogen excretion, the amount of nitrogen retained, and N.P.U. did not show any significant differences among all the groups. 6. Serum total protein concentrations did not show any significant differences among all the groups.

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