Foods protected by the important biological antioxidant: Uric acid

Uric acid has been proposed as an antioxidant in biological fluids especially in humans. It is shown that uric acid can be used effectively to protect food and model food preparations against oxidation. Precooked cereal flakes and food emulsions were stabilised with varying levels of uric acid.     

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.     

Soymilk fermented with Lactobacillus rhamnosus CRL981 ameliorates hyperglycemia,lipid profiles and increases antioxidant enzyme activities in diabetic mice

Interest in soybeans and soy-based products has grown significantly in the last decades due to their reported nutritional and health-promoting effects. In soybean and non-fermented soy foods, isoflavones are predominantly found as glucosides, which must be hydrolyzed in order to exert their documented beneficial effects. The objective of this study was to evaluate the effect of soymilk fermented with Lactobacillus rhamnosus CRL981, a strain that can completely hydrolyze glucoside isoflavones due to its high beta-glucosidase activity. Using a diabetes animal model induced with streptozotocin, it was shown that the fermented soymilk was able to significantly decrease glucose levels, total cholesterol concentrations, triacylglycerols and increase antioxidant enzyme activities compared to animals that received unfermented soymilk. This study clearly shows that the adequate selection of starter cultures could be used to develop novel soy based products intended for the prevention or adjuvant treatment of diseases such as diabetes.     

Influence of intraocular scattered light on lightness-scaling experiments

Following Munsell's bisection procedure [J. Opt. Soc. Am. 23, 394 (1933)], we established a nine-step gray scale in which each step is an equal increment in lightness. We calculated retinal illuminances after intraocular scatter by using the point-spread function of Vos et al. [Vision Res. 16, 215-219 (1976)]. After this correction for intraocular scatter, we find a logarithmic relationship between retinal illuminance and achromatic lightness scales that are determined by the bisection method. Additional bisection experiments with a series of different backgrounds corroborate this result. We find that lightness depends linearly on the logarithm of scatter-corrected retinal illuminance, with different slopes for backgrounds of different lightness. This study also highlights the importance of using scatter-corrected illuminance in any quantitative model of lightness.     

The preparation of porcine (Tyr-A14-2H) insulin and its characterization by mass spectrometry

The title compound was prepared by catalytic deiodination of(Tyr-A¹⁴-3-I) insulin with deuterium gas. Under special conditions(large excess of PdO in CH₃OD/D₂O at pH 9.2) developed to minimizeproblems due to poisoning of the catalyst, deuterated insulinwas produced in yields of about 35% after purification by reversedphase HPLC. For analysis, the deuterated insulin was digestedwith V8 protease and was shown by mass spectrometry to haveincorporated deuterium to an extent of 96.6 atom %, exclusivelyin a pentapeptide containing Tyr A¹⁴. The title compound shouldprove useful to those workers studying insulin by mass spectrometry,and use of the method with tritium gas in place of deuteriumshould permit the preparation of a specifically labelled radioactiveinsulin analogue which behaves identically to the natural hormone.     

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.