871 resultados para glucose transporter 4


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Among different classes of ionic liquids (ILs), those with cyano-based anions have been of special interest due to their low viscosity and enhanced solvation ability for a large variety of compounds. Experimental results from this work reveal that the solubility of glucose in some of these ionic liquids may be higher than in water – a well-known solvent with enhanced capacity to dissolve mono- and disaccharides. This raises questions on the ability of cyano groups to establish strong hydrogen bonds with carbohydrates and on the optimal number of cyano groups at the IL anion that maximizes the solubility of glucose. In addition to experimental solubility data, these questions are addressed in this study using a combination of density functional theory (DFT) and molecular dynamics (MD) simulations. Through the calculation of the number of hydrogen bonds, coordination numbers, energies of interaction and radial and spatial distribution functions, it was possible to explain the experimental results and to show that the ability to favorably interact with glucose is driven by the polarity of each IL anion, with the optimal anion being dicyanamide.

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Dissertação de Mestrado, Ciências Biomédicas, Departamento de Medicina e Ciências Biomédicas, Universidade do Algarve, 2015

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"Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation ofmaximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, whichmay be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period."

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Clinical translation of BCRP inhibitors have failed due to neurotoxicity and novel approaches are required to identify suitable modulators of BCRP to enhance CNS drug delivery. In this study we examine 18 compounds, primarily phytochemicals, as potential novel modulators of AhR-mediated regulation of BCRP expression and function in immortalised and primary porcine brain microvascular endothelial cells as a mechanism to enhance CNS drug delivery. The majority of modulators possessed a cellular viability IC50 > 100 µM in both cell systems. BCRP activity, when exposed to modulators for 1 hour, was diminished for most modulators through significant increases in H33342 accumulation at < 10 µM with 2,6,4-trimethoflavone increasing H33342 intracellular accumulation by 3.7–6.6 fold over 1–100 µM. Western blotting and qPCR identified two inducers of BCRP (quercetin and naringin) and two down-regulators (17-β-estradiol and curcumin) with associated changes in BCRP efflux transport function further confirmed in both cell lines. siRNA downregulation of AhR resulted in a 1.75 ± 0.08 fold change in BCRP expression, confirming the role of AhR in the regulation of BCRP. These findings establish the regulatory role AhR of in controlling BCRP expression at the BBB and confirm quercetin, naringin, 17-β-estradiol, and curcumin as novel inducers and down-regulators of BCRP gene, protein expression and functional transporter activity and hence potential novel target sites and candidates for enhancing CNS drug delivery.

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Subtle structural differencescan be observed in the islets of Langer-hans region of microscopic image of pancreas cell of the rats having normal glucose tolerance and the rats having pre-diabetic(glucose intolerant)situa-tions. This paper proposes a way to automatically segment the islets of Langer-hans region fromthe histological image of rat's pancreas cell and on the basis of some morphological feature extracted from the segmented region the images are classified as normal and pre-diabetic.The experiment is done on a set of 134 images of which 56 are of normal type and the rests 78 are of pre-diabetictype. The work has two stages: primarily,segmentationof theregion of interest (roi)i.e. islets of Langerhansfrom the pancreatic cell and secondly, the extrac-tion of the morphological featuresfrom the region of interest for classification. Wavelet analysis and connected component analysis method have been used for automatic segmentationof the images. A few classifiers like OneRule, Naïve Bayes, MLP, J48 Tree, SVM etc.are used for evaluation among which MLP performed the best.

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A low temperature synthesis method based on the decomposition of urea at 90°C in water has been developed to synthesise fraipontite. This material is characterised by a basal reflection 001 at 7.44 Å. The trioctahedral nature of the fraipontite is shown by the presence of a 06l band around 1.54 Å, while a minor band around 1.51 Å indicates some cation ordering between Zn and Al resulting in Al-rich areas with a more dioctahedral nature. TEM and IR indicate that no separate kaolinite phase is present. An increase in the Al content however, did result in the formation of some SiO2 in the form of quartz. Minor impurities of carbonate salts were observed during the synthesis caused by to the formation of CO32- during the decomposition of urea.

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Raman spectra were recorded in the range 400–1800 cm−1 for a series of 15 mixed \[tetrakis(4-tert-butylphenyl)porphyrinato](2,3-naphthalocyaninato) rare earth double-deckers M(TBPP)(Nc) (M = Y; La–Lu except Pm) using laser excitation at 632.8 and 785 nm. Comparisons with bis(naphthalocyaninato) rare earth counterparts reveal that the vibrations of the metallonaphthalocyanine M(Nc) fragment dominate the Raman features of M(TBPP)(Nc). When excited with radiation of 632.8 nm, the most intense vibration appears at about 1595 cm−1, due to the naphthalene stretching. These complexes exhibit the marker Raman band for Nc•− as a medium-intense band in the range 1496–1507 cm−1, attributed to the coupling of pyrrole and aza stretching, while the marker Raman band of Nc2− in intermediate-valence Ce(TBPP)(Nc) appears as a strong band at 1493 cm−1 and is due to the isoindole stretchings. By contrast, when excited with radiation of 785 nm that is in close resonance with the main Q absorption band of the naphthalocyanine ligand, the ring radial vibrations at ca 680 and 735 cm−1 for MIII(TBPP)(Nc) are selectively intensified and are the most intense bands. For the cerium double-decker, the most intense vibration also acting as the marker Raman band of Nc2− appears at 1497 cm−1 with contributions from both pyrrole CC and aza CN stretches. The same vibrational modes show weak to medium intensity scattering at 1506–1509 cm−1 for MIII(TBPP)(Nc) and this is the marker Raman band of Nc•− when thus excited. The scatterings due to the Nc breathings, ring radial vibration, aza group stretchings, naphthalene stretchings, benzoisoindole stretchings and the coupling of pyrrole CC and aza CN stretchings in MIII(TBPP)(Nc) are all slightly blue shifted along with the decrease in rare earth ionic radius, confirming the effects of increased ring–ring interactions on the Raman characteristics of naphthalocyanine in the mixed ring double-deckers.