Use of HEPG2 cells to assay the safety of cosmetic active substances

The importance of this study is based on the need to obtain simple and efficient in vitro models to predict the in vivo toxicity of cosmetics, aiming not to use animals as experimental model. Here, we proposed the use of HepG2 cells, which are widely applied to simulate the hepatic function of the human organism in vitro. This cell line was chose since recent studies have shown that the liver is potentially the most frequently targeted organ by cosmetic ingredients, and beyond that, considering the widely application of in vitro assays to test the cutaneous permeation of cosmetic products, including the assays applying modified Franz cells, this technique becomes indispensable. Three different cosmetic active substances were used, and the toxicity to HepG2 cells was assessed by the MTT method. The treatment with hyaluronic acid showed no toxicity to HepG2 cells. Treating the cells with P. guajava L. extract were verified that increasing the amount of the extract in the media, the cellular viability decreased, and finally, the treatment of alpha-lipoic acid showed a cytoprotective effect in relation to the treatment with propylene glycol. The study demonstrated the suitability in using HepG2 cells to assess the safety of cosmetic active substances, helping in the prediction of if the substance could be hepatotoxic if could reach the bloodstream

Rhamnolipids as biosurfactants from renewable resources: Concepts for next-generation rhamnolipid production

Several microorganisms are known to produce a wide variety of surface-active substances, which are referred to as biosurfactants. Interesting examples for biosurfactants are rhamnolipids, glycolipids mainly known from Pseudomonas aeruginosa produced during cultivation on different substrates like vegetable oils, sugars, glycerol or hydrocarbons. However, besides costs for downstream processing of rhamnolipids, relatively high raw-material prices and low productivities currently inhibit potential economical production of rhamnolipids on an industrial scale. This review focuses on cost-effective and sustainable production of rhamnolipids by introducing new possibilities and strategies regarding renewable substrates. Additionally, past and recent production strategies using alternative substrates such as agro-industrial byproducts or wastes are summarized. Requirements and concepts for next-generation rhamnolipid producing strains are discussed and potential targets for strain-engineering are presented. The discussion of potential new strategies is supported by an analysis of the metabolism of different Pseudomonas species. According to calculations of theoretical substrate-to-product conversion yields and current world-market price analysis, different renewable substrates are compared and discussed from an economical point of view. A next-generation rhamnolipid producing strain, as proposed within this review, may be engineered towards reduced formation of byproducts, increased metabolic spectrum, broadened substrate spectrum and controlled regulation for the induction of rhamnolipid synthesis. (C) 2012 Elsevier Ltd. All rights reserved.

Distribution of Cr, Ni, Cu, Cd and Pb in different molecular size of humic fractions extracted from water and sediment samples collected at Anhumas reservoir - Araraquara/SP

In this work was studied the distribution of Cr, Ni, Cu, Cd and Pb in humic fractions with different molecular size. The HS were extracted from waters (AHS), surface sediments (HESS), interface water sediment (HSIS) and bottom sediment (HSBS) collected in the Anhumas surface water collection reservoir, located in the district of Araraquara - São Paulo State Brazil. The humic substances were extracted by procedures recommended by International Humic Substances Society (IHSS). After purification by dialysis, the humic substances were fractionated using a multistage tangential flow ultrafiltration system. The fractionation patterns of HS characterized a mass distribution relatively uniform among the fractions with different molecular sizes, with larger values in the fractions F-2 (20.8%) and F-4 (23.8%), Except for the ions Pb(II) and Cu(II), which presented relatively higher concentrations in the fractions F-2 and F-4, respectively. In general, chromium, nickel, cadmium and lead have similar distributions in the five fractions with larger and medium molecular sizes (F-1 to F-5). With relation to the mass distributions in the different humic substances fractions extracted from sediment samples collected at three depth, they presented 42-48% of HS in the fractions with larger molecular sizes (F-1 and F-2), 29-31% in the middle fractions (F-3 and F-4) and 13-20% in the fractions with smaller molecular sizes (F-5 and F-6). In general, the metallic ions presented distributions similar among the respective fractions F-1 to F-6, Exceptions for Pb(II) and M(II) in surface sediment with concentrations relatively smaller in the fractions F-2 and F-4, respectively,

Nutritional strategies of physically active subjects with muscle dysmorphia

Background: The aim of this study was to identify dietary strategies for physically active individuals with muscle dysmorphia based on a systematic literature review. Method. References were included if the study population consisted of adults over 18 years old who were physically active in fitness centers. We identified reports through an electronic search ofScielo, Lilacs and Medline using the following keywords: muscle dysmorphia, vigorexia, distorted body image, and exercise. We found eight articles in Scielo, 17 in Medline and 12 in Lilacs. Among the total number of 37 articles, only 17 were eligible for inclusion in this review. Results: The results indicated that the feeding strategies used by physically active individuals with muscle dysmorphia did not include planning or the supervision of a nutritionist. Diet included high protein and low fat foods and the ingestion of dietary and ergogenic supplements to reduce weight. Conclusion: Physically active subjects with muscle dysmorphia could benefit from the help of nutritional professionals to evaluate energy estimation, guide the diet and its distribution in macronutrient and consider the principle of nutrition to functional recovery of the digestive process, promote liver detoxification, balance and guide to organic adequate intake of supplemental nutrients and other substances. © 2013 Contesini et al.; licensee BioMed Central Ltd.

Reduction capability of soil humic substances from the Rio Negro basin, Brazil, towards Hg(II) studied by a multimethod approach and principal component analysis (PCA)

This paper characterizes humic substances (HS) extracted from soil samples collected in the Rio Negro basin in the state of Amazonas, Brazil, particularly investigating their reduction capabilities towards Hg(II) in order to elucidate potential mercury cycling/volatilization in this environment. For this reason, a multimethod approach was used, consisting of both instrumental methods (elemental analysis, EPR, solid-state NMR, FIA combined with cold-vapor AAS of Hg(0)) and statistical methods such as principal component analysis (PCA) and a central composite factorial planning method. The HS under study were divided into groups, complexing and reducing ones, owing to different distribution of their functionalities. The main functionalities (cor)related with reduction of Hg(II) were phenolic, carboxylic and amide groups, while the groups related with complexation of Hg(II) were ethers, hydroxyls, aldehydes and ketones. The HS extracted from floodable regions of the Rio Negro basin presented a greater capacity to retain (to complex, to adsorb physically and/or chemically) Hg(II), while nonfloodable regions showed a greater capacity to reduce Hg(II), indicating that HS extracted from different types of regions contribute in different ways to the biogeochemical mercury cycle in the basin of the mid-Rio Negro, AM, Brazil. (c) 2007 Published by Elsevier B.V.

Neustonic distribution of decapod planktonic stages and competence of brachyuran megalopae in coastal waters

Settlement rate may not reflect larval supply to coastal waters in different marine invertebrates and demersal fishes. The importance of near-shore oceanography and behaviour of late larval stages may be underestimated. The present study conducted neustonic sampling over station grids and along full-length transects at two embayments in south-eastern Brazil to (1) compare diurnal and nocturnal occurrence of most frequent decapod stages to assess their vertical movements, (2) describe the formation of larval patches and (3) measure competence of crab megalopae according to their distance to recruitment grounds. Several shrimp species apparently undergo a diel vertical migration, swimming crab megalopae showed no vertical movements and megalopae of the intertidal crab Pachygrapsus transversus revealed a reversed vertical migration. During the day, crab megalopae aggregated in convergence zones just below surface slicks. These larvae consisted of advanced, pre-moult stages, at both mid-bay and near-shore patches. Competence, measured as the time to metamorphosis in captivity, was similar between larval patches within each taxon. Yet, subtidal portunids moulted faster to juveniles than intertidal grapsids, possibly because they were closer to settlement grounds. Megalopae of Pachygrapsus from benthic collectors moulted faster than those from bay areas. These results suggest that alternative vertical migration patterns of late megalopae favour onshore transport, and actual competence takes place very close to suitable substrates, where larvae may remain for days before settlement. Lack of correlation between larval supply and settlement for Pachygrapsus suggests that biological processes, besides onshore transport, may play an important role in determining settlement success of coastal crabs.

Vertical distribution of benthic invertebrate larvae during an upwelling event along a transect off the tropical Brazilian continental margin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Surface Hydration and Application Method on the Bond Strength of Self-Etching Adhesives to Dentin

The effect of application methods and dentin hydration on the bond strength of three self-etching adhesives (SEA) were evaluated; 195 extracted bovine incisors were used. The buccal surface was ground in order to expose the dentin, which remained 2-mm minimum thickness, measured by a thickness meter through an opening on the lingual surface. Adper Single Bond 2 (TM) was used for the control group. The SEA were applied following two modes of application: passive or active and two hydration states of the dentin surface-dry and wet. After light-curing, composite buildups were made using Grandio (TM) composite. The specimens were sectioned and tested with a microtensile bond strength test. The application method and the hydration state resulted in statistical differences (p = 0.000) making the values of active application for mu TBS to dentin higher than passive application. The wet surfaces showed higher mu TBS to dentin ratios than dry surfaces. There were no statistical differences in mu TBS among the SEA tested but there were differences regarding to control group.

Effects of Surface Hydration State and Application Method on the Bond Strength of Self-etching Adhesives to Cut Enamel

Purpose: To evaluate the effect of surface hydration state and application method on the microtensile bond strength of one-step self-etching adhesives systems to cut enamel.Materials and Methods: One hundred ninety-five bovine teeth were used. The enamel on the buccal side was flattened with 600-grit SiC paper. For the control group, 15 teeth received Adper Single Bond 2, applied according to manufacturer's recommendations. The other specimens were divided into three groups according to the adhesive system used: Futura Bond M (FM; Voco), Clearfil S-3 Bond (CS; Kuraray), and Optibond All in One (OA; Kerr). For each group, two hydration states were tested: D: blown dry with air; W: the excess of water was removed with absorbent paper. Two application methods were tested: P (passive): the adhesive was simply left on the surface; A (active): the adhesive was rubbed with an applicator point. A coat of Grandio composite resin (Voco) was applied on the surface. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm), which underwent microtensile bond testing. The data in MPa were submitted to a three-way ANOVA and Tukey's test (alpha = 5%).Results: The ANOVA showed significant differences for application method and the type of adhesive, but not for hydration state. For the application method, the results of Tukey's test were: P: 31.46 (+/-7.09)a; A: 34.04 (+/-7.19)b. For the type of adhesive, the results were: OA: 31.29 (+/-7.05)a; CS: 32.28 (+/-7.14)a; FM: 34.68 (+/-7.17)b; different lower-case letters indicate statistically significant differences.Conclusion: Active application improved the bond strength to cut enamel. The adhesive Futurabond M showed the highest bond strength to cut enamel.

Spatial distribution of solutes and water in sucrose solution dehydrated apples

Half-fresh apples were immersed in sucrose solution (50% w/w, 27 degrees C) during different times of exposition (2, 4, and 8 h). Then each fruit was sliced from the transversal exposed surface. Density, water, and sugar content were determined for each slice. A mathematical model was fitted to experimental data of water and sucrose content considering the global flux and the tissue shrinkage. By numerical analysis, the binary effective diffusion coefficients as a function of concentration were calculated, using material coordinates and integrating simultaneously two differential equations (for water and sucrose). The coefficients obtained are one or even two orders of magnitude lower than the ones for pure solutions and present an unusual concentration dependence. This comparison shows the influence of the tissue resistance to the diffusion.

Distribution of refractory and volatile elements in CoRoT exoplanet host stars

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The protist Trichomonas vaginalis harbors multiple lineages of transcriptionally active Mutator-like elements

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Taxonomy and distribution of Paralemanea (Lemaneaceae, Rhodophyta) in Central Mexico

Three collections of Paralemanea from Central Mexico included two species. Paralemanea mexicana is large (length ≥ 4.0 cm; diameter > 400 μm) and generally branched (≥ 40 % of plants branched), with whorled branches, of first to second order. Paralemanea annulata is small (length < 5.0 cm ; diameter < 500 μm), generally unbranched (≤ 5 % of plants branched), with branches of first order. Spermatangial sori contained obovoid spermatangia, formed from cells of the outer cortical layers, extending above the thallus surface. Carpogonial branches are described for the first time in P. mexicana. They develop on lateral filaments at nodes or internodes and have ovoid to globular cells, abundantly branched at the basal portion, penetrating the cortex towards the thallus surface. Carposporophytes are sessile on the inner portion of the cortex and produce carpospores in chains of up to twelve. The 'Chantransia' stage was observed in P. mexicana. Paralemanea annulata is described for the first time from Mexico and P. mexicana is endemic from this country. Both species were collected in cold (temperature 12-16°C), acidic (pH 5.5-6.0), shallow (depth 1-60 cm) and moderate to fast flowing waters (> 35 cm s-1), in shaded or partly shaded river segments, on rocky substrata (mostly bedrock).

The influence of the flexibility of the chair seat on pressure peak and distribution of the contact area in individuals with cerebral palsy during the execution of a task

This study aimed to determine the influence of flexibility of the chair seat surface on the pressure peak and on the contact area during the execution of a task of handling an object on the seated position by individuals with spastic cerebral palsy. Ten individuals of both genders with diagnosis of spastic cerebral palsy, who had some control to voluntarily move the body and the upper limbs, participated in this study. Quantification of data was carried out in two experimental situations: (1) execution of a task of fitting with upper limbs, and with the individual placed on an adapted canvas seat; (2) execution of a task of fitting with the participant positioned on an adapted wooden seat. Data obtained were submitted to a non-parametric and descriptive statistical analysis using the Wilcoxon test. Results indicated that the use of canvas seat increased the contact area and decreased the pressure peak and the medio-lateral displacement of centre pressure on the seated posture. © 2011 Informa UK, Ltd.