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Ren S Hylemon P Zhang ZP Rodriguez-Agudo D Marques D Li X Zhou H Gil G Pandak WM 《Journal of lipid research》2006,47(5):1081-1090
This study reports the discovery of a novel sulfonated oxysterol found at high levels in the mitochondria and nuclei of primary rat hepatocytes after overexpression of the gene encoding steroidogenic acute regulatory protein (StarD1). Forty-eight hours after infection of primary rat hepatocytes with recombinant adenovirus encoding StarD1, rates of bile acid synthesis increased by 4-fold. Concurrently, [(14)C]cholesterol metabolites (oxysterols) were increased dramatically in both the mitochondria and nuclei of StarD1-overexpressing cells, but not in culture medium. A water-soluble [(14)C]oxysterol product was isolated and purified by chemical extraction and reverse-phase HPLC. Enzymatic digestion, HPLC, and tandem mass spectrometry analysis identified the water-soluble oxysterol as 5-cholesten-3beta,25-diol 3-sulfonate. Further experiments detected this cholesterol metabolite in the nuclei of normal human liver tissues. Based upon these observations, we hypothesized a new pathway by which cholesterol is metabolized in the mitochondrion. 相似文献
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The interaction of chlorpromazine (CPZ) with artificial membranes (egg-yolk phosphatidylcholine liposomes) has been studied. Measurements of the surface electric potential, which is modified in the presence of the ionized form of the drug, were obtained by electron paramagnetic resonance spectroscopy (EPR) using a positively charged amphiphilic spin-probe. This probe partitions between the aqueous and lipidic phases depending on the surface potential and on the structural state of the membrane. The surface potential was measured as a function of drug concentration in the range where the spectral line-shapes are not affected by the incorporation of the drug. From these experimental results and through an appropriate formalism we obtain information on the binding of the drug to the lipid bilayer and on the ionization of the drug in the lipidic phase.
Correspondence to: C. Anteneodo 相似文献
106.
de Melo Reis RA Ventura AL Schitine CS de Mello MC de Mello FG 《Neurochemical research》2008,33(8):1466-1474
Müller cells represent the main type of glia present in the retina interacting with most, if not all neurons in this tissue.
Müller cells have been claimed to function as optic fibers in the retina delivering light to photoreceptors with minimal distortion
and low loss [Franze et al (2007) Proc Natl Acad Sci 104:8287–8292]. Most of the mediators found in the brain are also detected
in the retinal tissue, and glia cells are active players in the synthesis, release, signaling and uptake of major mediators
of synaptic function. Müller glia trophic factors may regulate many different aspects of neuronal circuitry during synaptogenesis,
differentiation, neuroprotection and survival of photoreceptors, Retinal Ganglion Cells (RGCs) and other targets in the retina.
Here we review the role of several transmitters and trophic factors that participate in the neuron-glia loop in the retina.
Special issue article in honor of Dr. Ricardo Tapia. 相似文献
107.
Adrian A. Garda Helga C. Wiederhecker Alison M. Gainsbury Gabriel C. Costa R. Alexander Pyron Gustavo H. Calazans Vieira Fernanda P. Werneck Guarino R. Colli 《Biotropica》2013,45(2):245-252
We investigate the role of ecology and phylogeny in the association between lizard abundance and microhabitat variables in an Amazon rain forest site. Using pitfall trap arrays, we collected data from 349 individuals belonging to 23 lizard species. After accounting for spatial autocorrelation and using a canonical correspondence analysis (CCA), we found that lizard captures were significantly associated with microhabitat variables, which accounted for 48 percent of the observed variation. Furthermore, a canonical phylogenetic ordination (CPO) indicated that microhabitat variables are more important in determining the distribution of lizard species than phylogenetic relationships among species. Termite nests, canopy openness, and tree circumference were strongly associated with the number of captures of certain lizard species. Our results confirm autecology studies of individual lizard species for which data are available. We suggest that maintaining heterogeneous forested microhabitats should be a central goal for sustaining a high lizard biodiversity in Amazon rain forests. 相似文献
108.
Egle Machado de Almeida Siqueira Fernanda Ribeiro Rosa Adriana Medeiros Fustinoni Lívia Pimentel de Sant'Ana Sandra Fernandes Arruda 《PloS one》2013,8(8)
The bioactive compounds content and the antioxidant activity (AA) of twelve fruits native to the Cerrado were compared with the Red Delicious apple by means of the antiradical efficiency (using the 2,2-diphenyl-1-picrylhydrazil assay/DPPH), ferric reducing antioxidant power (FRAP) and the β-carotene/linoleic system. The antiradical efficiency (AE) and the kinetic parameters (Efficient concentration/EC50 and time needed to reach the steady state to EC50 concentration/TEC50) of the DPPH curve were also evaluated for comparison with the Trolox equivalent (TE) values. A strong, significant and positive correlation was observed between the TE and AE values, whereas a weak and negative correlation was observed between TE and EC50, suggesting that the values of AE and TE are more useful for the determination of antiradical activity in fruits than the widely used EC50. The total phenolic content found in the fruits corresponded positively to their antioxidant activity. The high content of bioactive compounds (flavanols, anthocyanins or vitamin C) relative to the apple values found in araticum, cagaita, cajuzinho, jurubeba, lobeira, magaba and tucum corresponded to the high antioxidant activity of these fruits. Flavanols and anthocyanins may be the main bioactive components in these Cerrado fruits. The daily consumption of at least seven of the twelve Cerrado fruits studied, particularly, araticum, cagaita, lobeira and tucum, may confer protection against oxidative stress, and thus, they may prevent chronic diseases and premature aging. The findings of this study should stimulate demand, consumption and cultivation of Cerrado fruits and result in sustainable development of the region where this biome dominates. 相似文献
109.
Nyéssia Fernanda De Sousa Silva MáRcia Regina Simões Adriana Knob Sandra Schmidt De Moraes Caroline Henn Jose Luis Da ConceiçãO Silva 《Biocatalysis and Biotransformation》2016,34(3):119-127
Xylanase produced from the newly isolated Penicillium crustosum FP 11 and its potential in the prebleaching of kraft pulp were evaluated using a statistical approach. A Plackett–Burman design (PBD) was carried out to select the significant variables of the medium, these being NaNO3, KH2PO4, MgSO4, KCl, Fe2(SO4)3, yeast extract, corn stover, and initial pH, in a liquid culture under static conditions for 6 d at 28?°C. Statistical analysis with a central composite design and response surface methodology showed that 0.15% (w/v) KH2PO4, 2% (w/v) corn stover, and an initial pH of 6.0 provided the best conditions for xylanase production. Furthermore, xylanase from P. crustosum FP 11 was effective in the bleaching of Eucalyptus kraft pulp, with a significant kappa efficiency of 35.04%. Therefore, the newly isolated P. crustosum FP 11 from the Atlantic Forest biome in Brazil showed two advantages: xylanase production with agricultural residue (corn stover) as a carbon source and an improvement in the bleaching of kraft pulp. Environmental pollution could thus be minimized because of a reduction in the use of chlorine as a bleaching agent. 相似文献
110.
da Paz Priscila Marques de Oliveira Juliana 《Bioprocess and biosystems engineering》2018,41(5):697-706
Bioprocess and Biosystems Engineering - This work is based on the importance of monitoring the thermodynamic variables of sugarcane juice fermentation by Saccharomyces cerevisiae, using a numerical... 相似文献