ω-3 Fatty acids in smooth muscle cell phospholipids increase membrane cholesterol efflux

The aim of our work was to determine whether fatty acid modifications in smooth muscle cell phospholipids affect cholesterol efflux and desorption. [³H]Cholesterol was used to label cholesterol pools in the whole cell or selectively in the plasma membrane. Cells were incubated for 12 h in order to increase oleate, linoleate, arachidonate, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in phospholipids. Cholesterol efflux was monitored using native or tetranitromethane modified high-density lipoprotein₃ (HDL₃). When all cholesterol pools were labeled, the efflux from cells treated with different fatty acids were not different. Plasma membrane cholesterol efflux remained unchanged after oleate, linoleate or arachidonate treatments, but was markedly increased after EPA and DHA enrichment, both with native HDL₃ and with tetranitromethane-high-density lipoprotein. These results suggest that the positive effects of n−3 fatty acid consumption on the atherosclerotic process could be linked in part to an increase in plasma membrane cholesterol efflux from vascular smooth muscle cells.     

Le phénomène de la transformation verbale: Nouvelles modalités de fonctionnement.

Investigated the effects of an irregular presentation of the stimulus repetition on the verbal transformation effect (VTE). Ss were 48 children (aged 8–13 yrs), 48 adults (aged 19–30 yrs), and 60 aged persons (aged 65–90 yrs), and were presented 4 separate stimuli repeated either irregularly (experimental group) or regularly (control group). Results show that VTE appeared earlier and provoked more verbal transformations (VTs) on an irregular stimulus presentation. In both conditions, there was a gradual increment in the number of VTEs as listening continued. Age group comparisons showed a marked decrease in VTE as Ss' ages increased. Finally, the choice of stimuli according to their absolute frequency of occurrence in the French language showed that high frequency words produced less VT than low frequency words; however, there was no significant difference for reaction time (RT) and number of forms on that variable. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of a commercially-available algal phlorotannins extract on digestive enzymes and carbohydrate absorption in vivo

The ability of naturally occurring polyphenols and phlorotannins (PHTs) from some species of brown seaweeds to inhibit α-amylase and α-glucosidase enzymes in vitro has already been demonstrated. This study aimed at validating the efficacy of a new food ingredient extracted from Ascophyllum nodosum and Fucus vesiculosus PHTs at inhibiting digestive enzymes in vitro and slowing carbohydrate absorption in vivo. In vitro, the PHT extract completely inhibited in a dose-dependent fashion α-amylase and α-glucosidase with very low IC₅₀ values compared to other plant polyphenols. In animals, the PHT extract was able to reduce the normal increase in postprandial blood glucose seen 30 min after a meal by 90% (p < 0.05), and consecutively reduce peak insulin secretion by 40%. These results demonstrate the potency of this specific PHT extract to beneficially modulate carbohydrate digestion and assimilation, in a way that would be suitable for use in foods and dietary supplement formulations.     

Simulation of QRST integral maps with a membrane-based computer heart model employing parallel processing

The simulation of the propagation of electrical activity in a membrane-based realistic-geometry computer model of the ventricles of the human heart, using the governing monodomain reaction-diffusion equation, is described. Each model point is represented by the phase 1 Luo-Rudy membrane model, modified to represent human action potentials. A separate longer duration action potential was used for the M cells found in the ventricular midwall. Cardiac fiber rotation across the ventricular wall was implemented via an analytic equation, resulting in a spatially varying anisotropic conductivity tensor and, consequently, anisotropic propagation. Since the model comprises approximately 12.5 million points, parallel processing on a multiprocessor computer was used to cut down on simulation time. The simulation of normal activation as well as that of ectopic beats is described. The hypothesis that in situ electrotonic coupling in the myocardium can diminish the gradients of action-potential duration across the ventricular wall was also verified in the model simulations. Finally, the sensitivity of QRST integral maps to local alterations in action-potential duration was investigated.     

Symbolic Test-generation in HOL-TESTGEN/CirTA A Case Study

HOL-TestGen/CirTA is a theorem-prover based test generation environment for speci cations written in Circus, a process-algebraic speci cation language in the tradition of CSP. HOL-TestGen/CirTA is based on a formal embedding of its semantics in Isabelle/HOL, allowing to derive rules over speci cation constructs in a logically safe way. Beyond the derivation of algebraic laws and calculi for process re nement, the originality of HOL-TestGen/ CirTA consists in an entire derived theory for the generation of symbolic test-traces, including optimized rules for test-generation as well as rules for symbolic execution. The deduction process is automated by Isabelle tactics, allowing to protract the state-space explosion resulting from blind enumeration of data. The implementation of test-generation procedures in CirTA is completed by an integrated tool chain that transforms the initial Circus speci cation of a system into a set of equivalence classes (or "symbolic tests"), which were compiled to conventional JUnit test-drivers. This paper describes the novel tool-chain based on prior theoretical work on semantics and test-theory and attempts an evaluation via a medium-sized case study performed on a component of a real-world safety-critical medical monitoring system written in Java. We provide experimental measurements of the kill-capacity of implementation mutants.     

Determination of 14 aminoglycosides by LC-MS/MS using molecularly imprinted polymer solid phase extraction for clean-up

An LC-MS/MS method for screening 14 aminoglycosides in foodstuffs of animal origin is presented. Its scope includes raw materials and processed ingredients but also finished products composed of milk, meat, fish, egg or fat. Aminoglycosides are extracted in an acidic aqueous solution, which is first recovered after centrifugation, then diluted with a basic buffer and finally purified by molecularly imprinted polymer-solid phase extraction (MIP-SPE). Analytes are detected within 8 min by ion-pair reversed phase LC-MS/MS. Due to the large range of foodstuffs involved, the variability of matrix effects led to significant MS signal variations. This was circumvented by systematically extracting each sample twice, i.e. ‘unspiked’ and ‘spiked’ at the screening target concentration of 50 µg kg^?1. The method was validated according to the European Community Reference Laboratories Residues Guidelines giving false-negative and false-positive rates ≤3% for all compounds. Ruggedness of the method was further demonstrated in quality control operations by a second laboratory. The 14 aminoglycosides in water-based standard solutions were stable for up to 6 months when stored at either ?80°C, ?20°C or at 4°C storage temperatures.     

Lipid biosynthesis in cultured arterial smooth muscle cells is related to their phenotype

During the atherogenic processin vivo, arterial smooth muscle cells (SMC) undergo changes in their phenotype. In the present study, rat SMC from primary cultures and from subcultures before 10 and after 200 passages, showing contractile-like, synthetic and transformed phenotypes, respectively, were compared in regard to their lipid content and biosynthesis. The rationale for comparing these phenotypes rests in the similar changes in phenotype of SMC that occur in the formation and progression of atherosclerotic lesions. Phenotype changes were shown to be associated with changes in the phospholipid content of SMC. Phospholipid levels increased, but not as significantly as did cholesterol levels when passing from contractile to synthetic and transformed cells (1.23±0.18, 2.28±0.26 and 3.25±0.23 μg/10⁶ cells, respectively). Cholesterol normalized in respect to cell protein was increased to the same extent. Lipid synthesis as judged by [¹⁴C]acetate incorporation was increased 3- to 12-fold in the synthetic and transformed cells, respectively, compared to contractile cells. After thin-layer chromatography, radioactivity was shown to be markedly increased in most of the lipid fractions, but label in the cholesterol fraction of synthetic and transformed cells was increased by 7- and 21-fold, respectively. Thus, SMCin vitro were shown to drastically increase cholesterol biosynthesis associated with phenotype changes. Such changes are known to occurin vivo and might represent a critical step in the deposition of excess cholesterol within foam cells.     

Energy saving potential and strategies for electric lighting in future North European, low energy office buildings: A literature review

This article presents key energy use figures and explores the energy saving potential for electric lighting in office buildings based on a review of relevant literature, with special emphasis on a North European context. The review reveals that theoretical calculations, measurements in full-scale rooms and simulations with validated lighting programs indicate that an energy intensity of around 10 kWh/m² yr is a realistic target for office electric lighting in future low energy office buildings. This target would yield a significant reduction in energy intensity of at least 50% compared to the actual average electricity use for lighting (21 kWh/m² yr in Sweden). Strategies for reducing energy use for electric lighting are presented and discussed, which include: improvements in lamp, ballast and luminaire technology, use of task/ambient lighting, improvement in maintenance and utilization factor, reduction of maintained illuminance levels and total switch-on time, use of manual dimming and switch-off occupancy sensors. Strategies based on daylight harvesting are also presented and the relevant design aspects such as effects of window characteristics, properties of shading devices, reflectance of inner surfaces, ceiling and partition height are discussed.     

Morphology and antibacterial properties of plasticized chitosan/metallocene polyethylene blends

In this work, plasticized chitosan-based materials were produced through a molten process. A thermo-mechanical treatment was used to achieve chitosan plasticization in the presence of water, acetic acid, and glycerol. Water and glycerol acted as plasticizers, while acetic acid was used as a solvent and plasticizer for chitosan. The influence of acetic acid total content, chitosan/acetic acid solution ratio, and chitosan/glycerol ratio were examined in this study. The various plasticized compounds were blended with a metallocene polyethylene (mPE) and the morphology, rheological, and antibacterial properties of this novel blend system were examined. It was found that an increase in acetic acid content allowed better chitosan dissolution, while a higher glycerol concentration resulted in improved dispersion of the plasticized chitosan phase in the mPE. Following thermo-mechanical treatment, blends presented good antibacterial properties with a reduction of the number of bacteria (non-pathogenic Escherichia coli) by 2 log(CFU/mL) for the chitosan-containing systems with respect to neat mPE. Mechanical properties of the mPE/plasticized chitosan blends were improved by compatibilization with ethylene vinyl acetate, while antibacterial properties were not affected.