• 제목/요약/키워드: molecular biological techniques

검색결과 158건 처리시간 0.028초

Radiotherapy for Ovarian Cancers - Redefining the Role

  • Rai, Bhavana;Bansal, Anshuma;Patel, Firuza Darius;Sharma, Suresh Chander
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권12호
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    • pp.4759-4763
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    • 2014
  • Radiation therapy in ovarian cancers has been considered an outdated concept for many years, mainly due to its toxicity and failure to show benefit in terms of survival. Chemotherapy has been extensively used after surgery for these cancers and it has almost replaced radiation therapy as an adjuvant treatment. Nevertheless, failures in ovarian cancers continue to occur even with the use of newer and effective chemotherapy regimens. About 70% patients demonstrate recurrence in the abdomen or pelvis after first line chemotherapy in ovarian cancers. With advances in technology and sophistication of radiation techniques, along with the molecular and biological knowledge of distinct histological subtypes, there is a need to redefine the role of radiation therapy. This review article focuses on the literature on use of radiation in ovarian cancers and its rationale and indications in the present day. For this, a literature pub med/medline search was performed from January 1975 to March 2014 to redefine the role of radiotherapy in ovarian cancers.

NEUTRON SCATTERING INVESTIGATIONS OF PROTON DYNAMICS OF WATER AND HYDROXYL SPECIES IN CONFINED GEOMETRIES

  • Chen, S.H.;Loong, C.K.
    • Nuclear Engineering and Technology
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    • 제38권3호
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    • pp.201-210
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    • 2006
  • This article presents a brief overview of an important area of neutron scattering: the general principles and techniques of elastic, quasielastic and inelastic scattering from a system composed predominately of incoherent scatterers. The methodology is then applied to the study of water, specifically when it is confined in nanometer-scale environments. The confined water exhibits uniquely anomalous properties in the supercooled state. It also nourishes biological functions, and supports essential chemical reactions in living systems. We focus on recent investigations of water encapsulated in nanoporous silica and carbon nanotubes, hydrated water in proteins and water or hydroxyl species incorporated in nanostructured minerals. Through these scientific examples, we demonstrate the advantages derived from the high sensitivity of incoherent neutron spectroscopy to hydrogen atom motions and hydrogen-bond dynamics, aided by rigorous data interpretation method using molecular dynamics simulations or theoretical modelling. This enables us to probe the inter-/intramolecular vibrations and relaxation/diffusion processes of water molecules in a complex environment.

Photo-induced inter-protein interaction changes in the time domain; a blue light sensor protein PixD

  • Terazima, Masahide
    • Rapid Communication in Photoscience
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    • 제4권1호
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    • pp.1-8
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    • 2015
  • For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

Polymethoxylated Flavone Extracts from Citrus Peels for Use in the Functional Food and Nutraceutical Industry

  • Yao, Xiaolin;Pan, Siyi;Duan, Chunhong;Yang, Fang;Fan, Gang;Zhu, Xinrong;Yang, Shuzhen;Xu, Xiaoyun
    • Food Science and Biotechnology
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    • 제18권5호
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    • pp.1237-1242
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    • 2009
  • Polymethoxylated flavones (PMFs) extracted from Citrus sinensis 'Jincheng' peel were characterized by chromatographic and spectroscopic techniques. Seven individual PMF were identified. 3, 3', 4', 5, 6, 7-hexamethoxyflavone (HEX), nobiletin (NOB), heptamethoxyflavone (HEP), 5-demethylnobiletin (DN), and tangeretin (TAN) were characterized through electrospray ionization mass spectrometry (ESI-MS) in positive mode of protonated molecular ions $[M+H]^+$, the diagnostic fragment ions, together with the UV-Vis spectra and high performance liquid chromatography (HPLC) elution order from literature data. Sinensetin (SIN) and tetramethyl-O-scutellarein (SCU) were isolated and identified through their MS, $^1H$ nuclear magnetic resonance (NMR) and UV-Vis spectral studies. The levels of PMFs in peels from different cultivars of citrus fruits grown in China were determined for the first time. The results showed that C. aurantium 'Bitter orange' peel was the most promising variety for HEP. C. sinensis peel was a good source for SIN and SCU.

An Enantioselective Amidase from Burkholderia multivorans for the Stereoselective Synthesis of Esfenvalerate

  • Lee, Sang-Hyun;Park, Oh-Jin;Shin, Hyun-Jae
    • Journal of Microbiology and Biotechnology
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    • 제24권7호
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    • pp.936-942
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    • 2014
  • Using racemic (R,S)-2-(4-chlorophenyl)-3-methylbutyramide, an intermediate for the chiral pyrethroid insecticide Esfenvalerate, as a sole nitrogen source in a minimal medium, several strains with high enatioselectivity (${\geq}98%$) were isolated by enrichment techniques. One of the strains, LG 31-3, was identified as Burkholderia multivorans, based on physiological and morphological tests by a standardized Biolog station for carbon source utilization. A novel amidase was purified from B. mutivorans LG 31-3 and characterized. The enzyme exhibited (S)-selective amidase activity on racemic (R,S)-2-(4-chlorophenyl)-3-methylbutyramide. Addition of the racemic amide induced the production of the enantioselective amidase. The molecular mass of the amidase on SDS-PAGE analysis was shown to be 50 kDa. The purified amidase was subjected to proteolytic digestion with a modified trypsin. The N-terminal and internal amino acid sequences of the purified amidase showed a high sequence homology with those deduced from a gene named YP_366732.1 encoding indole acetimide hydrolase from Burkholderia sp. 383.

Detection of Mycobacterium leprae by Real-time PCR Targeting Mycobacterium leprae-Specific Repetitive Element Sequence

  • Jin, Hyun-Woo;Wang, Hye-Young;Kim, Jong-Pill;Cho, Sang-Nae;Lee, Hye-Young
    • 대한의생명과학회지
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    • 제16권2호
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    • pp.127-131
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    • 2010
  • Mycobacterium leprae detection is difficult even with molecular biological techniques due to the low sensitivity of current methodologies. In this report, real-time PCR targeting the M. leprae-specific repetitive element (RLEP) sequence was developed as a new diagnostic tool and evaluated using clinical specimens. For this, M. leprae DNAs were extracted from skin biopsy specimens from 80 patients and analyzed by real-time PCR using TaqMan probe. Then, the detection efficiency of the real-time PCR was compared with that of standard PCR. In brief, the rate of positive detection by the standard PCR and real-time PCR was 32.50% and 66.25%, respectively. The results seemed to clearly show that the TaqMan real-time PCR developed in this study may be a useful tool for sensitive detection of M. leprae from clinical specimens.

Phytomonitoring of the Genotoxicity of Environmental Pollutants: An Application to Armenian Nuclear Power Plant

  • Kim, Jin Kyu;Aroutiounian, Rouben M.;Nebish, Anna A.;Kim, Jin-Hong
    • 방사선산업학회지
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    • 제9권4호
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    • pp.181-185
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    • 2015
  • Today the biosafety evaluation, a common problem of vital importance, is based on internationally proved test-systems, standards and techniques. The paradigm of biosafety includes multidisciplinary approach, a combination of physical, chemical and biological tests to monitor the environmental level of pollutants and needs to be improved by modern approaches. The genetic risk of environmental pollutions has long been studied by many researchers. In this study, used was the known sensitive plant test-system, clones of plant Tradescantia (spiderwort) able to detect gene mutations (frequency of mutational events and formation of micronuclei) in combination with chemical and, in some instances, with radiological measurements. In addition, male gametophyte generation of fruit trees was applied as bioindicators of genotoxicity. The obtained results did not show any significant increase along with wind direction. As for the male gametophyte assay, the fertility of the investigated fruit-trees near to NPP did not significantly differ from that of the control point. The influence of the NPP on the male generative system of the investigated taxa of fruit trees for the investigated year was not revealed. The system described needs to be expanded by species of interest (human) as there is a difficulty to transfer the revealed dose correlations to humans. The development of this idea includes various levels: population (epidemiological studies), individual, cellular, molecular (DNA), etc.

Signal amplification by reversible exchange in various alcohol solvents

  • Jeong, Hye Jin;Namgoong, Sung Keon
    • 한국자기공명학회논문지
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    • 제25권4호
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    • pp.64-69
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    • 2021
  • In the developed NMR hyperpolarization techniques, Signal amplification by reversible exchange (SABRE) technique is thought to be a promising method to overcome the low sensitivity of bio-NMR/MRI. Most experiments using SABRE have been done in methanol, which is biologically harmful solvent. Therefore, more biological friendly solvent, such as ethanol can be more appropriate solvent to be applicable in bio-NMR and MRI. As the proof of concept, successful hyperpolarization on pyridine via SABRE is carried out in ethanol and its enhancement factor is calculated to be more than 150 folds. To investigate more about its possibility of hyperpolarization in different alcohol solvents, methanol and propanol are used for SABRE in the same condition. The overall polarization trend in different external magnetic field is similar but its polarization number is decreased with higher molecular weight solvents (the order from methanol to propanol). This result indicates that the efficiency of SABRE is different from solvent system despite its same functional group and similar properties. Higher para-hydrogen concentration, higher partial pressure of para-hydrogen, and deuterated solvent can increase the hyperpolarization in any solvents. With these series of successful SABRE results, future studies on SABRE in more biofriendly environment, on more various solvent systems, and with more substrates are needed and it will be the firm basis for applying the SABRE system on the future bio-NMR/MRI.

Synthesis, spectral, thermal, structural study and theoretical treatment of new complexes of mannich base with Ni(II) and study of cytotoxicity effect on (Hepa-2) cell line and antimicrobial activity

  • Omar H. Al-Obaidi
    • 분석과학
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    • 제36권2호
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    • pp.70-79
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    • 2023
  • The synthesis of the Mannich base as a ligand (L) N-(morpholino (phenyl) methyl) acetamide is the subject of this study. Elemental analyses, FT-IR spectra, UV-vis, 1H-NMR, and magnetic measurements were used to confirm the synthesis of the [Ni(L)2]Cl2 complex, thermal analysis (TG/DTG), atomic absorption, and scanning, and structurally explained as electron microscopy (SEM), and X-ray powder diffraction (XRD) methods. The melting point of the complex and its molar conductivity were also measured. The suggested geometries of the complexes formed have a tetrahedral structure, according to the data acquired using various techniques. Theoretical approaches to the complex formation have been investigated. For molecular mechanics and semi-empirical calculations, the HYPERCHEM6 program had been used. The effect of the novel Ni(II) complex on the cancer cell Hepa-2 (human hepatocellular ademocarcinoma), that is the human laryngeal cancer, was studied. It has been found that these ligand and complex have potent effects on the cancer cell. The antibacterial activity of the free ligand and its complex was evaluated against two kinds of human pathogenic bacteria. The first category is Gram-positive (Staphylococcus aureas, epiderimids), whereas the second group is Gram-negative (Psedamonas aeruginosa, Escherichia coli) (from the diffusion method). Finally, it was discovered that various chemicals had varied growth-inhibiting effects on bacteria.

The Development of Herbal Medicine Network Analysis System

  • Ho Jang
    • 한국컴퓨터정보학회논문지
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    • 제28권10호
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    • pp.113-121
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    • 2023
  • 한의학 및 중의학 분야에서 네트워크 약리학은 계산학적인 방법을 통해 한약의 분자생물학적인 기전을 연구하기 위해 널리 활용된다. 개별 연구를 위해 사용되는 데이터베이스, 분석기법, 분석기준 등은 다양하나, 대부분의 한의학 네트워크 약리학 연구들은 약재-성분 네트워크 구축, 성분-표적 네트워크 구축, 표적의 해석이라는 유사한 단계로 수행된다. 효율적이고 일관성있는 한의학 네트워크 약리학 분석을 위해서, 우리는 일반적으로 적용할 수 있는 한의학 네트워크 분석 파이프라인 시스템을 설계하고 구현하였다. 우리는 이 시스템의 신뢰성을 약재의 네트워크 약리학 분석을 위해 널리 사용되는 데이터베이스를 활용해서 확인하였다. 제안된 시스템은 다양한 한약에 대한 네트워크 약리학적 분석을 용이하게 하고, 일관성 있는 분석을 도울 것이다.