The Chick Chorioallantoic Membrane Model: A New In Vivo Tool to Evaluate Breast Cancer Stem Cell Activity

The high plasticity of cancer stem-like cells (CSCs) allows them to differentiate and proliferate, specifically when xenotransplanted subcutaneously into immunocompromised mice. CSCs are highly tumorigenic, even when inoculated in small numbers. Thus, in vivo limiting dilution assays (LDA) in mice are the current gold standard method to evaluate CSC enrichment and activity. The chick embryo chorioallantoic membrane (CAM) is a low cost, naturally immune-incompetent and reproducible model widely used to evaluate the spontaneous growth of human tumor cells. Here, we established a CAM-LDA assay able to rapidly reproduce tumor specificities—in particular, the ability of the small population of CSCs to form tumors. We used a panel of organotropic metastatic breast cancer cells, which show an enrichment in a stem cell gene signature, enhanced CD44⁺/CD24^−/low cell surface expression and increased mammosphere-forming efficiency (MFE). The size of CAM-xenografted tumors correlate with the number of inoculated cancer cells, following mice xenograft growth pattern. CAM and mice tumors are histologically comparable, displaying both breast CSC markers CD44 and CD49f. Therefore, we propose a new tool for studying CSC prevalence and function—the chick CAM-LDA—a model with easy handling, accessibility, rapid growth and the absence of ethical and regulatory constraints.     

Impact of white-matter mask selection on DTI histogram-based metrics as potential biomarkers in cerebral small vessel disease

Magnetic Resonance Materials in Physics, Biology and Medicine - Histogram-based metrics extracted from diffusion-tensor imaging (DTI) have been suggested as potential biomarkers for cerebral small...     

Encoding Cryptographic Primitives in a Calculus with Polyadic Synchronisation

We thoroughly study the behavioural theory of epi, a ??-calculus extended with polyadic synchronisation. We show that the natural contextual equivalence, barbed congruence, coincides with early bisimilarity, which is thus its co-inductive characterisation. Moreover, we relate early bisimilarity with the other usual notions, ground, late and open, obtaining a lattice of equivalence relations that clarifies the relationship among the ??standard?? bisimilarities. Furthermore, we apply the theory developed to obtain an expressiveness result: epi extended with key encryption primitives may be fully abstractly encoded in the original epi calculus. The proposed encoding is sound and complete with respect to barbed congruence; hence, cryptographic epi (crypto-epi) gets behavioural theory for free, which contrasts with other process languages with cryptographic constructs that usually require a big effort to develop such theory. Therefore, it is possible to use crypto-epi to analyse and to verify properties of security protocols using equational reasoning. To illustrate this claim, we prove compliance with symmetric and asymmetric cryptographic system laws, and the correctness of a protocol of secure message exchange.     

Experimental renewal in human participants.

Two experiments with human participants are presented that differentiate renewal from other behavioral effects that can produce a response after extinction. Participants played a video game and learned to suppress their behavior when sensor stimuli predicted an attack. Contexts (A, B, & C) were provided by fictitious galaxies where the game play took place. In Experiment 1, participants who received conditioning in A, extinction in B, and testing in A showed some context specificity of conditioning during extinction and a recovery of suppression on test. Experiment 2 demonstrated recovery of extinguished responding when participants were conditioned in A, extinguished in B, and tested in C, a third, neutral context. The experiment also demonstrated that the context of extinction did not control performance by becoming inhibitory. Results are discussed in terms of mechanisms that can produce a response recovery after extinction. The experiments demonstrated a renewal effect: a response recovery that was not attributable to the contexts acting as simple conditioned stimuli and is the first work with human participants to conclusively do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sustainability assessment of dwellings – a comparison of methodologies

Building sustainability assessment tools (BSATs) aim to promote and rank the sustainability of building stock. This paper makes a deep comparative analysis on how dwellings are evaluated by five BSAT and one performance-based design tool. The comparison is based on: (i) the purpose of assessment; (ii) sustainability dimensions considered; (iii) indicators addressed; (iv) life cycle phases considered by the indicators; (v) type of indicators; (vi) measurements; (vii) aggregation processes; and (vii) life cycle phases during which the assessment was carried out. The evaluation showed that the scope of BSAT varies significantly as well as the life cycle phases addressed in the assessment. Financial issues are often excluded from the assessment. None of the schemes is totally quantitative or qualitative in their measurement system; all have different types of indicators and different ways to assess them. This research provides researchers and stakeholders with important inside knowledge on the tools that allow the development and construction of more sustainable buildings.     

Spray drying conditions for orange juice incorporated with lactic acid bacteria

This work aimed to develop an orange juice powder by spray drying with lactic acid bacteria (Lactobacillus plantarum 299v and Pediococcus acidilactici HA‐6111‐2), testing their survival both during drying and storage (room temperature and 4 °C). Initially, the best conditions for spray drying were chosen to allow the best survival of each LAB: (i) inlet air temperature of 120 °C and (ii) 0.5:2 ratio of the orange juice soluble solids and drying agent added (prebiotics: 10 DE maltodextrin or gum Arabic). Survival of LAB was not affected by drying process, and it was higher when cultures were stored at 4 °C. A slightly higher protection was conferred by 10 DE maltodextrin, in the case of L. plantarum and at 4 °C. Pediococcus acidilactici was more resistant during storage at 4 °C, with logarithmic reductions lower than 1 log‐unit. It was demonstrated that it is possible to produce a functional nondairy product, orange juice powder supplemented with prebiotic compounds, containing viable LAB for at least 7 months, when stored at 4 °C.     

A feasibility study of Lactobacillus plantarum in fruit powders after processing and storage

The aim of this study was to develop fruit powders (apple, banana and strawberry) enriched with a probiotic strain (Lactobacillus plantarum 299v). Two methodologies were proposed: (i) drying of the fruit with probiotic culture incorporated (by convection) or (ii) drying of fruit (by convection) and addition of spray‐dried probiotic culture. In the first methodology, processing caused a notable reduction in probiotic viable counts in apple, but this reduction was lower during drying of banana and strawberry. A large reduction in viable cells was also recorded during storage. In the second methodology, the survival of L. plantarum 299v was considerably higher during spray‐drying, and fruit powders with a microbial content suitable for a probiotic food (10⁸–10⁹ cfu g^?1) were obtained. The fruit powders incorporating L. plantarum 299v can be stored at 4 °C or at room temperature, for at least 3 months. This preliminary study demonstrated that fruit powders are good carriers of probiotic cultures, but the techniques used to produce them should be carefully considered.     

Synthesis and Characterization of Allyl Fatty Acid Derivatives as Reactive Coalescing Agents for Latexes

This work evaluated the use of allyl fatty acid esters derived from vegetable oil (palmitic acid, soybean and sunflower oils) as reactive coalescing agents in a waterborne latex system. Allyl fatty acid derivatives (AFAD) from vegetable oils were synthesized by two different processes. The synthesis was monitored by IR-spectroscopy and the final product characterized by FT-IR, GC–MS, ¹H and ¹³C NMR. The presence of conjugated double bonds in the aliphatic chain was confirmed, which is a determinant for the proposed autoxidative latexes drying mechanism. Each of the AFAD were subsequently added to a standard acrylic emulsion, in order to study its potential as reactive coalescing agent. The minimum film-forming temperature (MFT), glass transition temperature (T _g), drying time and rubbing resistance to solvents were evaluated. The results showed that, when added to water-borne acrylic resins, an AFAD acts as a non-volatile plasticizer capable of autoxidative crosslinking with itself.     

The Impact of Polyoxyethylene Sorbitan Surfactants in the Microstructure and Rheological Behaviour of Emulsions Made With Melted Fat From Cupuassu (<Emphasis Type="Italic">Theobroma grandiflorum</Emphasis>)

Cupuassu fat is a good candidate for partial substitution of cocoa butter in many products, including emulsions. However, for such use it is necessary to know the characteristics of the products prepared with cupuassu fat. Therefore, the main goal of this work is to characterize emulsions prepared with cupuassu fat using the surfactants Tween^® 60, Tween^® 80 and Tween^® 85 as emulsifiers. The emulsions were prepared at 43 °C with addition of 0.5 or 1.5 % (w/v) of surfactant and compared with an emulsion without surfactant. All emulsions were analysed by conductivity, stability, pH, optical microscopy, rheology and oxidative stability. It was verified that the emulsions prepared with Tween^® 60 and Tween^® 80 have higher stability, smaller droplet size and higher apparent viscosity. Also, these properties are positively influenced by the concentration of the surfactant. On the other hand, emulsions prepared with Tween 85 or without surfactant reached unsatisfactory results. The rheological behaviour of the emulsions was adequately described by both Herschel-Bulkley and Mizhari-Berki models revealing pseudoplastic character. These emulsions also present strong gel behaviour, with storage modulus higher than loss modulus. In conclusion, cupuassu fat can be used as oil phase for emulsions products and this characterization helps to understand their behaviour in order to increase their use in food industry.