Effect of C5-Methylation of Cytosine on the UV-Induced Reactivity of Duplex DNA: Conformational and Electronic Factors

International audienceC5-methylation of cytosines is strongly correlated with UV-induced mutations detected in skin cancers. Mutational hot-spots appearing at TCG sites are due to the formation of pyrimidine cyclobutane dimers (CPDs). The present study, performedfor the model DNA duplex (TCGTA)3·(TACGA)3 and the constitutive single strands, examines the factors underlying the effect of C5-methylation on pyrimidine dimerization at TCG sites. This effect is quantified for the first time by quantum yields ϕ.They were determined following irradiation at 255, 267, and 282 nm and subsequent photoproduct analysis using HPLC coupled to mass spectrometry. C5-methylation leads to an increase of the CPD quantum yield up to 80% with concomitant decrease of that of pyrimidine(6−4) pyrimidone adducts (64PPs) by at least a factor of 3. The obtained ϕ values cannot be explained only by the change of the cytosine absorption spectrum upon C5-methylation. The conformational and electronic factors that may affect the dimerization reaction are discussed in light of results obtained by fluorescence spectroscopy,molecular dynamics simulations, and quantum mechanical calculations. Thus, it appears that the presence of an extra methyl on cytosine affects the sugar puckering, thereby enhancing conformations of the TC step that are prone to CPD formation but less favorable to 64PPs. In addition, C5-methylation diminishes the amplitude of conformational motions in duplexes; in the resulting stiffer structure, ππ* excitations may be transferred from initially populated exciton states to reactive pyrimidines giving rise to CPDs

Evaluación de la estabilidad en el tiempo del contenido proteico en variedades de arveja

El objetivo del presente trabajo ha sido evaluar la estabilidad del contenido proteico de las variedades desarrolladas por INTA y la Facultad de Ciencias Agrarias de la Universidad Nacional de Rosario y las disponibles en el mercado, contemplando tanto el comportamiento en la producción primaria como la calidad industrial de los granos producidos a la hora de producir aislados proteicos.EEA OliverosFil: Accoroni, Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros. Laboratorio de Agroindustria; ArgentinaFil: Magnano, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros; ArgentinaFil: Espósito, María Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros; Argentin

Excited State Pathways Leading to Formation of Adenine Dimers

International audienceThe reaction intermediate in the path leading to UV-induced formation ofadenine dimers A=A and AA* is identified for the first time quantum mechanically, usingPCM/TD-DFT calculations on (dA)2 (dA: 2′deoxyadenosine). In parallel, its fingerprint isdetected in the absorption spectra recorded on the millisecond time-scale for the singlestrand (dA)20 (dA: 2′deoxyadenosine)

Chapter The offshore environmental impact by Sarno river in Naples bay (South-West Italy)

The goal of this work has been to establish the influence of the Sarno river on the present sedimentation in the Naples bay continental shelf by evaluating organic matter contribution and pollution. Sediments samples were collected, by van Veen grab, in 71 stations located offshore the Sarno river between Vesuvian and Sorrento Peninsula coasts. The characteristics of the surface sediments were analysed to highlight spatial trends in the (i) granulometry (grain-size); (ii) total nitrogen, organic carbon and total phosphorus; (iii) metal content (Hg, Cd, Pb, As, Cr, Cu, Ni, Zn, Fe and Mn)

Identification of a Sorbicillinoid-Producing Aspergillus Strain with Antimicrobial Activity Against Staphylococcus aureus: a New Polyextremophilic Marine Fungus from Barents Sea

The exploration of poorly studied areas of Earth can highly increase the possibility to discover novel bioactive compounds. In this study, the cultivable fraction of fungi and bacteria from Barents Sea sediments has been studied to mine new bioactive molecules with antibacterial activity against a panel of human pathogens. We isolated diverse strains of psychrophilic and halophilic bacteria and fungi from a collection of nine samples from sea sediment. Following a full bioassay-guided approach, we isolated a new promising polyextremophilic marine fungus strain 8Na, identified as Aspergillusprotuberus MUT 3638, possessing the potential to produce antimicrobial agents. This fungus, isolated from cold seawater, was able to grow in a wide range of salinity, pH and temperatures. The growth conditions were optimised and scaled to fermentation, and its produced extract was subjected to chemical analysis. The active component was identified as bisvertinolone, a member of sorbicillonoid family that was found to display significant activity against Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 30 μg/mL. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Human neutrophil migration and activation by BJcuL, a galactose binding lectin purified from Bothrops jararacussu venom

<p>Abstract</p> <p>Background</p> <p>Neutrophil migration to an inflamed site constitutes the first line of the innate immune response against invading microorganisms. Given the crucial role of endogenous lectins in neutrophil mobilization and activation, lectins from exogenous sources have often been considered as putative modulators of leukocyte function. Lectins purified from snake venom have been described as galactoside ligands that induce erythrocyte agglutination and platelet aggregation. This study evaluated human neutrophil migration and activation by C-type lectin BJcuL purified from <it>Bothrops jararacussu </it>venom.</p> <p>Results</p> <p>Utilizing fluorescence microscopy, we observed that biotinylated-BJcuL was evenly distributed on the neutrophil surface, selectively inhibited by D-galactose. Lectin was able to induce modification in the neutrophil morphology in a spherical shape for a polarized observed by optical microscopy and exposure to BJcuL in a Boyden chamber assay resulted in cell migration. After 30 minutes of incubation with BJcuL we found enhanced neutrophil functions, such as respiratory burst, zymozan phagocytosis and an increase in lissosomal volume. In addition, BJcuL delays late apoptosis neutrophils.</p> <p>Conclusion</p> <p>These results demonstrate that BJcuL can be implicated in a wide variety of immunological functions including first-line defense against pathogens, cell trafficking and induction of the innate immune response since lectin was capable of inducing potent neutrophil activation.</p

Cytocompatibility of poly(p-dioxanone)/ poly(hydroxybutic) (PPD/PHB) blends to cartilage tissue engineering

In order of seek strategies to improve the interaction between bioreabsorbable polymer materials and cellular growth, this work aimed at evaluating in vitro the influence of PPD/PHB blends on cell adhesion and fibrochondrocytes growth. Fibrochondrocytes cells were obtained by primary extraction from enzymatic digestion methods. The PPD/PHB blends were prepared by casting with 100/0, 60/40 and 50/50 compositions, and were characterized by scanning electron microscopy (SEM). After 6, 48, 120 and 168 hours in culture, ultrastructural observations showed changes in cell morphology, suggesting that the fibrochondrocytes can respond to substrate modifications, changing their phenotypic profile. The MTT analyses showed that the blends did not present cytotoxicity and allowed fibrochondrocytes adhesion and proliferation on the membranes in all compositions. The colorimetric Sirius Red test revealed the capability of extracellular matrix synthesis on the blends, from which one can conclude that the PPD/PHB blends are not cytotoxic and can be indicated for cell culture.Buscando estratégias que repercutam na melhoria da interação entre materiais poliméricos biorreabsorvíveis e o crescimento celular, o presente estudo in vitro teve como objetivo estudar a influência de blendas de PPD/PHB na adesão celular e crescimento de fibrocondrócitos obtidos a partir de cultura primária. As blendas de PPD/PHB foram preparadas pelo método de evaporação de solvente nas composições 100/0, 60/40 e 50/50 e caracterizadas por microscopia eletrônica de varredura (MEV). Observações ultra-estruturais mostraram alterações na morfologia celular, sugerindo que os fibrocondrócitos podem responder a alterações no substrato alterando seu perfil fenotípico. As análises com MTT demonstraram que as blendas não apresentaram citotoxicidade e permitiram a adesão e proliferação dos fibrocondrócitos sobre os substratos em todas as suas composições. O ensaio colorimétrico com Sirius Red evidenciou a capacidade de manutenção da síntese de matriz extracelular colágena sobre as amostras, concluindo-se que as blendas de PPD/PHB podem ser indicadas para o cultivo celular.383388Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Gene expression profile of rat left ventricles reveals persisting changes following chronic mild exercise protocol: implications for cardioprotection

<p>Abstract</p> <p>Background</p> <p>Epidemiological studies showed that physical exercise, specifically moderate lifelong training, is protective against cardiovascular morbidity and mortality. Most experimental work has focused into the effects and molecular mechanisms underlying intense, rather than mild exercise, by exploring the acute effect of training. Our study aims at investigating the cardioprotective effect of mild chronic exercise training and the gene expression profile changes at 48 hrs after the exercise cessation. Rats were trained at mild intensity on a treadmill: 25 m/min, 10%incline, 1 h/day, 3 days/week, 10 weeks; about 60% of the maximum aerobic power. By Affymetrix technology, we investigated the gene expression profile induced by exercise training in the left ventricle (LV) of trained (n = 10) and control (n = 10) rats. Cardioprotection was investigated by ischemia/reperfusion experiments (n = 10 trained vs. n = 10 control rats).</p> <p>Results</p> <p>Mild exercise did not induce cardiac hypertrophy and was cardioprotective as demonstrated by the decreased infarct size (p = 0.02) after ischemia/reperfusion experiments in trained with respect to control rats. Ten genes and 2 gene sets (two pathways) resulted altered in LV of exercised animals with respect to controls. We validated by real-time PCR the increased expression of four genes: similar to C11orf17 protein (RGD1306959), caveolin 3, enolase 3, and hypoxia inducible factor 1 alpha. Moreover, caveolin 3 protein levels were higher in exercised than control rats by immunohistochemistry and Western Blot analysis. Interestingly, the predicted gene similar to C11orf17 protein (RGD1306959) was significantly increased by exercise. This gene has a high homology with the human C11orf17 (alias: protein kinase-A interacting protein 1 or breast cancer associated gene 3). This is the first evidence that this gene is involved in the response to the exercise training.</p> <p>Conclusion</p> <p>Our data indicated that few, but significant, genes characterize the gene expression profile of the rat LV, when examined 48 hrs since the last training section and that mild exercise training determines cardioprotection without the induction of hypertrophy.</p

GESTÃO AMBIENTAL E SUSTENTABILIDADE: ANÁLISE DAS PRÁTICAS SUSTENTÁVEIS DA UNIVERSIDADE FEDERAL DE SANTA MARIA

Ao longo dos anos, o Brasil, passou por reformas administrativas, e com isso, novas ferramentas e práticas de gestão foram introduzidas nas organizações públicas a fim de melhorar a eficiência e reduzir custos, como é o caso das práticas sustentáveis. Nesse sentido, o presente estudo tem por objetivo analisar as práticas de gestão ambiental e sustentabilidade adotadas pela Universidade Federal de Santa Maria – UFSM com base nos Relatórios de Gestão (RG), no período 2014-2016. Quanto aos procedimentos metodológicos, realizou-se um estudo de natureza qualitativa, do tipo descritivo por meio de análise documental e de conteúdo. Foram analisados os aspectos de gestão ambiental e sustentabilidade nos Relatórios de Gestão da Universidade Federal de Santa Maria (UFSM), no período 2014-2016. Os resultados apontaram que, apesar da Instituição não participar da Agenda Ambiental da Administração Pública (A3P), a UFSM realiza a separação e a destinação de resíduos recicláveis a associações e/ou cooperativas de catadores. Além disso, possui um Plano de Gestão Logística Sustentável (PLS) e as contratações e compras seguem as orientações de decretos e normas voltados para compras públicas sustentáveis e logísticas reversa

La letteratura dal punto di vista degli scrittori

La storia della critica letteraria è stata generalmente esaminata dal punto di vista degli studiosi di teoria. Manca, a tutt’oggi, una visione d’insieme che esamini in maniera sistematica la critica letteraria dal punto di vista interno, ovvero degli autori stessi. Muovendo da tali premesse, il volume propone un’articolata analisi dei «discorsi» sulla letteratura prodotti da scrittori di lingua inglese, dalla seconda metà del Cinquecento a oggi. Allo scopo di dare ordine a una materia ampia e frastagliata, sono state individuate tre principali tipologie discorsive, o forme testuali, attraverso cui gli autori hanno dato voce alle proprie idee sulla letteratura. A tali tipologie discorsive corrispondono le tre sezioni in cui è stata suddivisa la materia critica del volume. La prima sezione, «Saggi e paratesti», esamina le teorie letterarie esposte in forma di saggi, prefazioni, commenti da parte dell’autore. La seconda sezione, «Disseminazioni», analizza le idee sulla letteratura sparse all’interno di romanzi, drammi, poesie. La terza sezione, infine, «Maschere d’autore», si concentra sulle teorie letterarie la cui esposizione è affidata a un alter ego dello scrittore, ovvero a una maschera parzialmente autobiografica. Ne emerge un quadro ricco e composito all’interno del quale teoria e prassi letteraria si arricchiscono reciprocamente, fino a fondersi in una più complessa unità i cui confini appaiono labili, indefiniti, negoziabili