Modulation of human multidrug-resistance MDR-1 gene by natural curcuminoids

BACKGROUND: Multidrug resistance (MDR) is a phenomenon that is often associated with decreased intracellular drug accumulation in patient's tumor cells resulting from enhanced drug efflux. It is related to the overexpression of a membrane protein, P-glycoprotein (Pgp-170), thereby reducing drug cytotoxicity. A variety of studies have tried to find MDR modulators which increase drug accumulation in cancer cells. METHODS: In this study, natural curcuminoids, pure curcumin, demethoxycurcumin and bisdemethoxycurcumin, isolated from turmeric (Curcuma longa Linn), were compared for their potential ability to modulate the human MDR-1 gene expression in multidrug resistant human cervical carcinoma cell line, KB-V1 by Western blot analysis and RT-PCR. RESULTS: Western blot analysis and RT-PCR showed that all the three curcuminoids inhibited MDR-1 gene expression, and bisdemethoxycurcumin produced maximum effect. In additional studies we found that commercial grade curcuminoid (approximately 77% curcumin, 17% demethoxycurcumin and 3% bisdemthoxycurcumin) decreased MDR-1 gene expression in a dose dependent manner and had about the same potent inhibitory effect on MDR-1 gene expression as our natural curcuminoid mixtures. CONCLUSION: These results indicate that bisdemethoxycurcumin is the most active of the curcuminoids present in turmeric for modulation of MDR-1 gene. Treatment of drug resistant KB-V1 cells with curcumin increased their sensitivity to vinblastine, which was consistent with a decreased MDR-1 gene product, a P-glycoprotein, on the cell plasma membrane. Although many drugs that prevent the P-glycoprotein function have been reported, this report describes the inhibition of MDR-1 expression by a phytochemical. The modulation of MDR-1 expression may be an attractive target for new chemosensitizing agents

Anthocyanins and Proanthocyanidins in Natural Pigmented Rice and Their Bioactivities

Natural pigmented rice is mainly black, red, and dark purple and contains a variety of flavones, tannins, phenolic, sterols, oryzanols, and essential oils. Anthocyanins and proanthocyanidins belonging to plant flavonoids are thought of as the major functional components found in black, red, and purple rice and contribute to the intense color of many fruits, vegetables, and pigmented cereals such as blueberries, grapes, red cabbages, and purple sweet potatoes. Recent data have indicated the potential for isolating and characterizing the nutrition and non-nutritive components in colored fruits, vegetables, and cereals for their potential chemopreventive and pharmaceutical agents. This chapter provides up-to-date coverage of pigmented rice in terms of the bioactive constituents, isolation, extraction and analytical methods, and related bioactivities. Special focus has been placed on the anti-inflammation, anticancer, and antiaging processes of the major components found in pigmented rice, especially with regard to germ and bran extracts

Reviews on Physically Based Controllable Fluid Animation

In computer graphics animation, animation tools are required for fluid-like motions which are controllable by users or animator, since applying the techniques to commercial animations such as advertisement and film. Many developments have been proposed to model controllable fluid simulation with the need in realistic motion, robustness, adaptation, and support more required control model. Physically based models for different states of substances have been applied in general in order to permit animators to almost effortlessly create interesting, realistic, and sensible animation of natural phenomena such as water flow, smoke spread, etc. In this paper, we introduce the methods for simulation based on physical model and the techniques for control the flow of fluid, especially focus on particle based method. We then discuss the existing control methods within three performances; control ability, realism, and computation time. Finally, we give a brief of the current and trend of the research areas

Influence of Carbon Black/Silica Hybrid Ratio on Properties of Passenger Car Tire Sidewall

Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passenger car tire (PCT) sidewall based on natural rubber (NR) and butadiene rubber (BR) blend was investigated. Rubbers filled with various hybrid filler ratios at a constant loading of 50 phr were prepared and tested. The filler reinforcement efficiency in association with crucial properties of the tire sidewall were of interest. Results show the enhanced rubber–filler interaction with increasing SiO2 fraction leading to the improvement in many vulcanizate properties including hardness, tensile strength, tear strength and fatigue resistance, at the expense of cure efficiency and hysteretic behaviors (i.e., reduced heat build-up resistance and increased dynamic set). The results also suggest the improvement in tire sidewall performance of the NR/BR vulcanizates reinforced with CB/SiO2 hybrid filler, compared to that of the CB-filled vulcanizate

AN ENHANCED DIFFERENTIAL EVOLUTION ALGORITHM WITH ADAPTIVE WEIGHT BOUNDS FOR EFFICIENT TRAINING OF NEURAL NETWORKS

Artificial neural networks are essential intelligent tools for various learning tasks. Training them is challenging due to the nature of the data set, many training weights, and their dependency, which gives rise to a complicated high-dimensional error function for minimization. Thus, global optimization methods have become an alternative approach. Many variants of differential evolution (DE) have been applied as training methods to approximate the weights of a neural network. However, empirical studies show that they suffer from generally fixed weight bounds. In this research, we propose an enhanced differential evolution algorithm with adaptive weight bound adjustment (DEAW) for the efficient training of neural networks. The DEAW algorithm uses small initial weight bounds and adaptive adjustment in the mutation process. It gradually extends the bounds when a component of a mutant vector reaches its limits. We also experiment with using several scales of an activation function with the DEAW algorithm. Then, we apply the proposed method with its suitable setting to solve function approximation problems. DEAW can achieve satisfactory results compared to exact solutions

Theoretical Study of the Adsorption of Ethylene on Alkali-Exchanged Zeolites

ABSTRACT: The structures of alkali-exchanged faujasite (X-FAU, X ϭ Li ϩ or Na ϩ ion) and ZSM-5 (Li-ZSM-5) zeolites and their interactions with ethylene have been investigated by means of quantum cluster and embedded cluster approaches at the B3LYP/6-31G (d, p) level of theory. Inclusion of the Madelung potential from the zeolite framework has a significant effect on the structure and interaction energies of the adsorption complexes and leads to differentiation of different types of zeolites (ZSM-5 and FAU) that cannot be drawn from a typical quantum cluster model, H 3 SiO(X)Al(OH) 2 OSiH 3 . The Li-ZSM-5 zeolite is predicted to have a higher Lewis acidity and thus higher ethylene adsorption energy than the Li-FAU zeolites (16.4 vs. 14.4 kcal/mol), in good agreement with the known acidity trend of these two zeolites. On the other hand, the cluster models give virtually the same adsorption energies for both zeolite complexes (8.9 vs. 9.1 kcal/mol). For the larger cation-exchanged Na-FAU complex, the adsorption energy (11.6 kcal/mol) is predicted to be lower than that of Li-FAU zeolites, which compares well with the experimental estimate of about 9.6 kcal/ mol for ethylene adsorption on a less acidic Na-X zeolite

Distribution of TGF-β1 C-509T polymorphism in Thai population

Transforming growth factor beta 1 (TGF-β1) C-509T gene polymorphism has been found to be associated with severity and susceptibility of many diseases. To examine the distribution of TGF-β1 C-509T (rs1800469) gene polymorphism in Thai population, 56 samples from unrelated healthy Thai volunteers were analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype frequencies of TGF-β1 C-509T polymorphisms were as follows: CC 12.5%, CT 39.3% and TT 48.2%, which showed no statistically  significant differences to those of Chinese (Han) (p=0.390), Italian (p=0.057), Serbian (p=0.554) and Brazilian (p=0.442) population. However, a statistically significant difference was observedbetween the genotype frequencies found in this study and those of Indian (p=0.005), Russian  (p=0.048), English (p=0.006), German (p=0.014), and Egyptian (p<0.0001) population. In addition, statistically significant differences were also observed between allele frequencies in Thai population in this study and those of other reported groups; including, Chinese (Han), Indian,Russian, Italian, English, German, Serbian, Egyptian, and Brazilian (p<0.05). The frequency of Tallele in Thai was significantly higher than that of C allele, whereas in other reported groups, the Callele frequencies were significantly higher than T allele frequencies (p<0.05). From the above data, it is likely that the distribution of TGF-β1 C-509T gene polymorphisms in Thai population is different from those of Asian, Caucasian, Egyptian, and Brazilian population. This observation may be useful and could be applied for treatment and prognostic of disease in the future. However, further studies in larger numbers of Thai subjects are required for confirmation

The novel synthesis of microporous and mesoporous materials and their applications for hydrocarbon transformation and chiral recognition

Dans ce travail nous étudions l élaboration, la caractérisation et les applications de différents matériaux poreux. L étude est organisée en trois parties majeures: la synthèse de zéolithes micro/mesoporeux et leur application potentielle dans l industrie pétrochimique, l étude théorique de mécanismes réactionnels sur des zeolites microporeux, et le design de métaux mesoporeux avec une chiralité intrinsèque de leur surface interne. Ces matériaux poreux montrent des propriétés excellentes, notamment pour des applications potentielles en catalyse et comme interfaces chirales.In the present work, the elaboration, characterisation and applications of differentporous materials have been studied. Porous materials are divided into three categoriesdepending on the porous cavity size, namely microporous materials (pore diameter 50 nm). The thesis work is organized in three major parts: the synthesisof hierarchical micro/mesoporous zeolites and their potential application for thepetrochemical industry, the theoretical study of reaction mechanisms on microporouszeolite and the design of mesoporous metals with intrinsic chirality at their inner surface.The hierarchical micro/mesoporous zeolite, composed of microporous andmesoporous features, has been prepared using carbon-silica (C/SiO2) composites derivedfrom a pyrolysis of hydrocarbon gas on silica gel. Our findings demonstrate that not onlythe presence of a high surface area and porosity, but also an improved efficiency of thesematerials for many petrochemical processes such as n-butene isomerization, nhexadecanecatalytic cracking and hydrocracking. The novel synthetic method is expectedto be generalized for other types of zeolites, and is considered to be a promising methodfor creating hierarchical micro/mesoporous zeolites for potential catalytic applications,especially in the petrochemical industry.In addition to the study of practical catalytic aspects, a theoretical approach hasbeen used to investigate potential reaction mechanisms such as the selective isomerizationof 1-butene into isobutene. More specifically, the monomolecular skeletal isomerizationof 1-butene into isobutene on H-FER zeolite was theoretically studied by using theONIOM approach. This process was found to involve the transformation of adsorbed 1-butene through 2-butoxide, isobutoxide, and tert-butyl cation intermediates. The ratedeterminingstep is the conversion of isobutoxide into isobutene, in which the reactionhas to proceed through the primary isobutyl cation transition state. The shape selectivitydue to the nano-confinement effect of the zeolite framework strongly affects theadsorption, the stability of alkoxide species and carbenium ion, as well as the skeletalisomerization mechanism of 1-butene.Moreover, the microporous and mesoporous zeolite, the generation of chiralmesoporous metal and its enantioselective recognition properties have been studied.Molecular imprinting (MI) is a major approach for generating materials withenantioselective properties. In this work, a chiral imprinted mesoporous platinum hasbeen obtained by the electrochemical reduction of platinum salts in the simultaneouspresence of a lyotropic liquid crystal phase and chiral template molecules. The resultingmaterials exhibit not only a dramatic increase in active surface area due to theirmesoporosity, but also a significant discrimination between two enantiomers of a chiralprobe, confirmed by both electrochemical and enantioselective adsorption experiments.Most importantly the porous platinum retains its chiral character even after removal of thechiral template molecule. Our findings could lead to the development of new materials,which are of potential interest for applications in areas such as chiral synthesis, sensors,separation, purification and drug development.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF