Immune Receptors and Co-receptors in Antiviral Innate Immunity in Plants

Plants respond to pathogens using an innate immune system that is broadly divided into PTI (pathogen-associated molecular pattern- or PAMP-triggered immunity) and ETI (effector-triggered immunity). PTI is activated upon perception of PAMPs, conserved motifs derived from pathogens, by surface membrane-anchored pattern recognition receptors (PRRs). To overcome this first line of defense, pathogens release into plant cells effectors that inhibit PTI and activate effector-triggered susceptibility (ETS). Counteracting this virulence strategy, plant cells synthesize intracellular resistance (R) proteins, which specifically recognize pathogen effectors or avirulence (Avr) factors and activate ETI. These coevolving pathogen virulence strategies and plant resistance mechanisms illustrate evolutionary arms race between pathogen and host, which is integrated into the zigzag model of plant innate immunity. Although antiviral immune concepts have been initially excluded from the zigzag model, recent studies have provided several lines of evidence substantiating the notion that plants deploy the innate immune system to fight viruses in a manner similar to that used for non-viral pathogens. First, most R proteins against viruses so far characterized share structural similarity with antibacterial and antifungal R gene products and elicit typical ETI-based immune responses. Second, virus-derived PAMPs may activate PTI-like responses through immune co-receptors of plant PTI. Finally, and even more compelling, a viral Avr factor that triggers ETI in resistant genotypes has recently been shown to act as a suppressor of PTI, integrating plant viruses into the co-evolutionary model of host-pathogen interactions, the zigzag model. In this review, we summarize these important progresses, focusing on the potential significance of antiviral immune receptors and co-receptors in plant antiviral innate immunity. In light of the innate immune system, we also discuss a newly uncovered layer of antiviral defense that is specific to plant DNA viruses and relies on transmembrane receptor-mediated translational suppression for defense

Magnetic liposomes containing calcium ferrite nanoparticles for breast cancer therapy

In this work, calcium ferrite nanoparticles were prepared and characterized. The structural and magnetic properties of the nanoparticles were evaluated by XRD, TEM and SQUID. The synthesized nanoparticles were either entrapped in liposomes, originating aqueous magnetoliposomes (AMLs), or covered with a lipid bilayer, forming solid magnetoliposomes (SMLs). Magnetoliposomes present average diameters around 150 nm, suitable for biomedical applications. The magnetoliposomes were loaded with new potential anticancer drugs, thienopyridine derivatives, with a strong antitumor activity against breast cancer cells.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2013) and of CQUM (UID/QUI/00686/2013). FCT, POPH-QREN and FSE are acknowledged for the PhD grants of A. R. O. Rodrigues (SFRH/BD/90949/2012) and V. A. Machado (SFRH/BD/77373/2011) and for financial support to MAP-Fis Joint Doctoral Programme.info:eu-repo/semantics/publishedVersio

Solid and aqueous magnetic liposomes as nanocarriers for a new potential drug active against breast cancer

In this work, iron oxide nanoparticles (NPs), with diameters around 12 nm, were synthesized by coprecipitation method. Both aqueous and solid magnetic liposomes containing magnetite NPs were obtained, with sizes below 140 nm. A new antitumor compound, a diarylurea derivative of thienopyridine, active against breast cancer, was incorporated in both aqueous and solid magnetoliposomes, being located mainly in the lipid membrane. A promising application of these magnetic liposomes in oncology is anticipated, allowing a combined therapeutic approach, using both chemotherapy and magnetic hyperthermia.Financial support by FCT-Portugal is acknowledged (Strategic Funding UID/FIS/04650/2013 and PhD grant SFRH/BD/90949/2012).info:eu-repo/semantics/publishedVersio

Cross-cultural adaptation of the City Birth Trauma Scale for the Brazilian context

Background: Posttraumatic stress disorder consists of a set of symptoms that occurs in response to one or more traumatic events and can occur in postpartum, from traumatic situations related to the birth or to the baby’s health in the first days of life. It is important tracking the presence of birth trauma, but there is not available instruments in the Brazilian context for this purpose. Objectives: To present the cross-cultural adaptation of City Birth Trauma Scale (BiTS) into Brazilian portuguese. Methods: Cross-cultural adaptation involved independent translations, synthesis,back-translation, and submission to the original author’s appreciation. After the scale was subjected to face validity, followed by a pilot study with postpartum mothers. Results: All steps were performed for the cross-cultural adaptation. Regarding face validity, items evaluated concerning different types of equivalence, presented satisfactory agreement values (≥4.20). Most of the expert’s suggestions were followed, being the main ones related to adjustments in prepositions, pronouns and verbal subjects. Pilot study showed that the mothers had been able to understand and respond to the instrument without adjustments. Discussion: BiTS’s Brazilian version proved to be cross-culturally adapted, ensuring the possibility of intercultural data comparison from the semantic, idiomatic, cultural, and conceptual perspectives. New studies are being conducted to attest its psychometric adequac

Improved X-ray detection and particle identification with avalanche photodiodes

Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2, and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g. to distinguish between x-rays and MeV electrons in our experiment.Comment: 6 pages, 6 figure