The potential risk factors associated with acute viral hepatitis in children under 5 years old]

In studies of the effects of salt intake on blood pressure (SBP, MBP, DBP), influences on heart rate (HR) are usually neglected even though the longterm load on both left ventricle (LV) and systemic arteries (SA) is better related to the product of HR x SBP (or MBP) than to pressure alone. After all, altered salt intakes often induce considerable volume-related changes in HR, and the heart operates more economically at low HR and high stroke volume (SV). Thus, about 3/4 of LV metabolism is used for the build-up of systolic tension, while the cost for SV expulsion, or for SV increases, is far lower. Moreover, low HR prolongs the diastolic period, so important for LV coronary supply. Against this background we have used results from studies in both rats and man, in which both BP and HR were followed during marked changes in salt intake, to explore how this affected the HR x SBP (or HR x MBP) product. Briefly, in ordinarily salt-resistant organisms, whether normo- or hypertensive, salt intake increases, which in man ranged from 10-20 to 250-300 mM (in rats over 100-fold), if anything reduced the computed longterm load (HR x SBP, or MBP) on LV and SA, as consequences of an efficient reflex volume control. By contrast, in salt-sensitive man, HR reflex reductions to increased salt intake were almost absent despite substantial SBP elevations, suggesting the influence of a CNS suppression of bulbar reflex centres combined with CNS neurohormonal interference with renal salt volume excretion, as in SHR.     

Disrupting the methionine biosynthetic pathway in Candida guilliermondii: characterization of the MET2 gene as counter‐selectable marker

Candida guilliermondii (teleomorph Meyerozyma guilliermondii) is an ascomycetous species belonging to the fungal CTG clade. This yeast remains actively studied as a result of its moderate clinical importance and most of all for its potential uses in biotechnology. The aim of the present study was to establish a convenient transformation system for C. guilliermondii by developing both a methionine auxotroph recipient strain and a functional MET gene as selection marker. We first disrupted the MET2 and MET15 genes encoding homoserine‐O‐acetyltransferase and O‐acetylserine O‐acetylhomoserine sulphydrylase, respectively. The met2 mutant was shown to be a methionine auxotroph in contrast to met15 which was not. Interestingly, met2 and met15 mutants formed brown colonies when cultured on lead‐containing medium, contrary to the wild‐type strain, which develop as white colonies on this medium. The MET2 wild‐type allele was successfully used to transfer a yellow fluorescent protein (YFP) gene‐expressing vector into the met2 recipient strain. In addition, we showed that the loss of the MET2‐containing YFP‐expressing plasmid can be easily observed on lead‐containing medium. The MET2 wild‐type allele, flanked by two short repeated sequences, was then used to disrupt the LYS2 gene (encoding the α‐aminoadipate reductase) in the C. guilliermondii met2 recipient strain. The resulting lys2 mutants displayed, as expected, auxotrophy for lysine. Unfortunately, all our attempts to pop‐out the MET2 marker (following the recombination of the bordering repeat sequences) from a target lys2 locus were unsuccessful using white/brown colony colour screening. Nevertheless, this MET2 transformation/disruption system represents a new versatile genetic tool for C. guilliermondii. Copyright © 2014 John Wiley & Sons, Ltd.     

Method for evaluation of the efficacy of antimicrobial preservatives in cosmetic wet wipes

Many cosmetic formulations are now available in the form of wet wipes packaged in sealed sachets or packets. Like the majority of cosmetic products having an aqueous phase, wipes are susceptible to microbial contamination and require the addition of preservatives. The efficacy of such preservatives can be evaluated using a standard challenge test performed on the wetting liquid but this test cannot be regarded as representative for this new type of formulation. The method presented here evaluates the efficacy of preservatives used in wet wipes kept in their original packaging. Dried inoculums were prepared by membrane filtration followed by drying in an incubator. The method is applicable to bacteria (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis), Bacillus cereus spores and fungi (Candida albicans and Aspergillus niger). These inoculated carriers were inserted between two wipes in the original package, which was then re-sealed immediately. The test requires one dry inoculum per packet and one packet for each control or test. After incubation at 22.5 degrees C for 1, 2, 7, 14 or 28 days and, for the control, immediately after insertion of the membrane (time 0), microorganism counts were performed on the germ-carrier membranes as well as on adjacent wipes, after transfer into a suitable neutralizing agent. The membranes were shaken in the presence of glass beads and microorganisms were dissociated from the wipes by means of a Stomacher. The supernatants recovered after being left to stand for 20 min are counted by pour plate method or membrane filtration. The feasibility of the method was demonstrated for each of the seven above-mentioned strains. The repeatability and reproducibility of the results obtained is similar to that obtained for preservative efficacy tests in the Pharmacopoeias. The lethal rate of microorganisms during the preparation of dry inoculums ranges from 50 to 90% depending on the strain and the test (generally, a spontaneous reduction of about 1 log up to a maximum of 2 log). The recovery rate for microorganisms from dry inoculums (on membranes) at time 0 (control = T(0)) is around 90%, regardless of the strain or the test. The number of microorganisms recovered from the wipes (W(0)) is between 2 and 10% of the number recovered from membranes (T(0)) and may be considered negligible. Application of this method to different types of wipes demonstrates that the efficacy of preservatives, expressed as the logarithmic reduction in the number of microorganisms at each time point, depends on the type of wipe and on the strain tested. The results obtained are considerably different from those found with the standard challenge tests applied to wetting liquids for wipes. The differences found confirm the need for a specific method applicable to wipes.     

Rheological characterisation of salad-dressing-type emulsions stabilised by egg yolk/sucrose distearate blends

The overall objective of this work was to fully characterise the rheological behaviour of oil/water emulsions stabilised by egg yolk and a sucrose ester of intermediate hydrophilic-lipophilic balance. The influence of the egg yolk/sucrose ester weight ratio in the emulsifier blend was studied by keeping the total amount of emulsifier constant. With this aim, steady state and transient flow tests, oscillatory measurements within the linear viscoelasticity regime and stress relaxation tests were carried out. Rheological tests were complemented with droplet size measurements. The results demonstrate that the rheological response and droplet size of the emulsions studied clearly depend on the weight ratio of emulsifiers in the binary blends. Steady-state and transient viscosities, as well as the dynamic functions, significantly increase with sucrose distearate concentration in the emulsifier blend. However, the evolution of other rheological parameters related to shear-induced structural breakdown, such as the critical strain for the onset of the non-linear viscoelastic behaviour, the relative deviation of the Cox-Merz rule, the time corresponding to the stress overshoot in transient tests or the damping function indicates a more developed and resistant structural network at higher egg yolk concentrations in the emulsifier blend. These results were discussed on the basis of a gel-like continuous phase formed by the sucrose ester and the highly flocculated state favoured by egg yolk.     

Carboxymethyl benzylamide dextran blocks angiogenesis of MDA-MB435 breast carcinoma xenografted in fat pad and its lung metastases in nude mice

We previously showed that carboxymethyl benzylamide dextran (CMDB7) prevents tumor growth and tumor angiogenesis by binding to angiogenic growth factors, thereby preventing them from reaching their receptors on tumor or stromal cells (Bagheri-Yarmand et al. Br. J. Cancer, 78: 111-118, 1998; Bagheri-Yarmand et al. Cell Growth Differ., 9: 497-504, 1998). In this study, CMDB7 inhibited neovessel formation within the fibroblast growth factor 2-enriched matrigel in mice, and its anticancer effect was then tested in a metastatic breast cancer model. Human MDA-MB435 cells were injected into the mammary fat pad of nude mice, and breast tumors developed within 1 week; all of the mice had lung metastases at 12 weeks. CMDB7 treatment (50, 150, or 300 s.c. or 300 i.v. mg/kg/week for 10 weeks) reduced the incidence of lung metastases to 12%. Histological analysis showed markedly less tumor neovascularization in the CMDB7-treated mice. Pulmonary metastasis incidence was strongly dependent on the intratumoral neoangiogenesis in primary tumors.     

Intergranular Oxidation of Nickel-Base Alloys: Potentialities of Focused Ion Beam Tomography

Oxidation of Metals - The present work focuses on the intergranular oxidation of Alloy 600 and its weld material Alloy 82 after exposure in simulated primary water at 340–360 °C...     

Etude longitudinale des inférences cinématiques chez le préadolescent et l'adolescent: evolution ou régression.

Investigated kinematic reasoning, the equation of the dimensions of time, space, and velocity. 282 students, aged 8–17 yrs, made judgments about a spatial representation of duration (the mark made by a vibrator on moving tape) and about the velocity of the tape. Results indicate 2 types of errors: (a) errors concerning the inverse relationship between velocity and space (VE errors) and (b) errors regarding the differentiation of duration relative to kinematic frame (T errors). VE type errors were mostly observed at 8–9 yrs of age, while T errors were observed between 10 and 17 yrs of age. An important result was an observed "return" to the T type error (after a time lapse of 1 yr) with Ss producing correct response patterns. Errors are analyzed within the context of a theoretical model of kinematic reasoning. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)