A study of the interaction between alfalfa (Medicago sativa) and one of its fungal pathogens, Colletotrichum trifolii.

The alfalfa/C. trifolii interaction follows a gene-for-gene interaction for race-cultivar specificity where in general, products of host resistance genes providing resistance to the fungus are interacting with direct or indirect products of avirulence genes (specific-elicitors) from the pathogen. The differential response for phytoalexin accumulation in alfalfa after C. trifolii infection, along with the nature of the interaction suggests the involvement of race-specific elicitors; however it was not possible to demonstrate their existence.Plant pathogens such as Collelotrichum trifolii have devastating effects on crop species. A rapid and effective activation of plant defenses is necessary for the establishment of resistance to the pathogen. The induction of several defense responses in alfalfa (Medicago sativa ) after infection by a virulent and avirulent race of C. trifolii was examined. A phytoalexin response was differentially induced in resistant and susceptible leaves. Free medicarpin and conjugates of medicarpin (glycosylated medicarpin) and formononetin (formononetin-7- O-glucoside) started to accumulate 24 and 48 hours after inoculation in resistant leaves, respectively, as opposed to 48 and 72 hours after inoculation in susceptible leaves. A more rapid induction of the phytoalexin response in resistant leaves compared to susceptible leaves was further demonstrated by the earlier accumulation of transcripts of genes involved in the biosynthesis of medicarpin, including PAL, CHR and IFR, 4 hours after inoculation.Glucanases are lytic enzymes that hydrolyse beta-1,3-glucans present in high amounts in fungal cell walls, and are produced by the plant after pathogen attack. Glucanases can directly affect fungi by digesting their cell walls, or indirectly by releasing elicitors that will activate plant defenses. The second potential role was investigated by constitutively expressing the aglu1 cDNA that encodes an alfalfa glucanase normally present in alfalfa leaves only after fungal infection, and study the effect of aglu1 expression on the phytoalexin response during infection by C. trifolii. The constitutive expression of the aglu1 transgene did not increase the phytoalexin response, therefore suggesting that aglu1 glucanase may not be involved in releasing elicitors from the fungal cell walls, at least for the fungus used in this study, C. trifolii.Genetic engineering has proven to be a powerful tool in plant disease control. Transgenic alfalfa plants transformed previously with a glucanase and/or a rice chitinase under the constitutive control of the CaMV 35S promoter were analyzed for their level of expression of glucanase and chitinase activities. No difference in chitinase activity could be detected. Differences in glucanase activity could be detected in plants transformed with the glucanase cDNA although the transgene was no longer constitutively expressed, suggesting that some other mechanisms increasing the glucanase activity level were occurring along with silencing of the transgene. Trangenic plants re-transformed with the aglu1 cDNA were evaluated for resistance against C. trifolii . Overexpressing the aglu1 transgene in alfalfa did not reduce the symptoms following pathogen attack. However, transgenic plants expressing the transgene produced other glucanase isoforms that may play a role in plant defense perhaps against other fungi. This needs to be further investigated

A indisciplina no ambiente escolar

Orientador : Dr. Ademir Aparecido Pinhelli MendesMonografia (especialização) - Universidade Federal do Paraná, Setor de Educação, Curso de Especialização em Coordenação PedagógicaInclui referênciasResumo : O presente trabalho buscou refletir sobre um tema muito recorrente no interior das escolas, a indisciplina. É um tema polêmico que desafia cotidianamente todos os envolvidos com a educação. Professores, pais e Poder Público sentem-se provocados a buscar alternativas para sanar as manifestações indisciplinares na escola. Hoje, é considerada como um dos problemas centrais no interior da escola, dentre os quais é responsabilizada como principal fator prejudicial ao processo ensino-aprendizagem. Este estudo foi realizado através de pesquisa bibliográfica e observação em Escola da Rede Pública do 6º ao 9º ano do Ensino Fundamental. Discute possibilidades de como orientar os professores a reverem suas práticas, a mediar às situações indisciplinares, a garantir qualidade das suas aulas e a escola a cumprir o seu papel, o de formar cidadãos críticos e reflexivos sobre o seu papel na sociedade

Activated αIIbβ3 on platelets mediates flow-dependent NETosis via SLC44A2.

Platelet-neutrophil interactions are important for innate immunity, but also contribute to the pathogenesis of deep vein thrombosis, myocardial infarction and stroke. Here we report that, under flow, von Willebrand factor/glycoprotein Ibα-dependent platelet 'priming' induces integrin αIIbβ3 activation that, in turn, mediates neutrophil and T-cell binding. Binding of platelet αIIbβ3 to SLC44A2 on neutrophils leads to mechanosensitive-dependent production of highly prothrombotic neutrophil extracellular traps. A polymorphism in SLC44A2 (rs2288904-A) present in 22% of the population causes an R154Q substitution in an extracellular loop of SLC44A2 that is protective against venous thrombosis results in severely impaired binding to both activated αIIbβ3 and VWF-primed platelets. This was confirmed using neutrophils homozygous for the SLC44A2 R154Q polymorphism. Taken together, these data reveal a previously unreported mode of platelet-neutrophil crosstalk, mechanosensitive NET production, and provide mechanistic insight into the protective effect of the SLC44A2 rs2288904-A polymorphism in venous thrombosis

Electrochemical measurements of the kinetics of inhibition of two FeFe hydrogenases by O2 demonstrate that the reaction is partly reversible

International audienceThe mechanism of reaction of FeFe hydrogenases with oxygen has been debated. It is complex, apparently very dependent on the details of the protein structure, and difficult to study using conventional kinetic techniques. Here we build on our recent work on the anaerobic inactivation of the enzyme [Fourmond et al, Nat. Chem. 4 336 (2014)] to propose and apply a new method for studying this reaction. Using electrochemical measurements of the turnover rate of hydrogenase, we could resolve the first steps of the inhibition reaction and accurately determine their rates. We show that the two most studied FeFe hydrogenases, from Chlamydomonas reinhardtii and Clostridium acetobutylicum, react with O2 according to the same mechanism, despite the fact that the former is much more O2 sensitive than the latter. Unlike often assumed, both enzymes are reversibly inhibited by a short exposure to O2. This will have to be considered to elucidate the mechanism of inhibition, before any prediction can be made regarding which mutations will improve oxygen resistance. We hope that the approach described herein will prove useful in this respect

Body mass index and waist circumference in relation to the risk of 26 types of cancer : a prospective cohort study of 3.5 million adults in Spain

A high body mass index (BMI) has been associated with increased risk of several cancers; however, whether BMI is related to a larger number of cancers than currently recognized is unclear. Moreover, whether waist circumference (WC) is more strongly associated with specific cancers than BMI is not well established. We aimed to investigate the associations between BMI and 26 cancers accounting for non-linearity and residual confounding by smoking status as well as to compare cancer risk estimates between BMI and WC. Prospective cohort study with population-based electronic health records from Catalonia, Spain. We included 3,658,417 adults aged ≥ 18 years and free of cancer at baseline between 2006 and 2017. Our main outcome measures were cause-specific hazard ratios (HRs) with 99% confidence intervals (CIs) for incident cancer at 26 anatomical sites. After a median follow-up time of 8.3 years, 202,837 participants were diagnosed with cancer. A higher BMI was positively associated with risk of nine cancers (corpus uteri, kidney, gallbladder, thyroid, colorectal, breast post-menopausal, multiple myeloma, leukemia, non-Hodgkin lymphoma) and was positively associated with three additional cancers among never smokers (head and neck, brain and central nervous system, Hodgkin lymphoma). The respective HRs (per 5 kg/m 2 increment) ranged from 1.04 (99%CI 1.01 to 1.08) for non-Hodgkin lymphoma to 1.49 (1.45 to 1.53) for corpus uteri cancer. While BMI was negatively associated to five cancer types in the linear analyses of the overall population, accounting for non-linearity revealed that BMI was associated to prostate cancer in a U-shaped manner and to head and neck, esophagus, larynx, and trachea, bronchus and lung cancers in an L-shaped fashion, suggesting that low BMIs are an approximation of heavy smoking. Of the 291,305 participants with a WC measurement, 27,837 were diagnosed with cancer. The 99%CIs of the BMI and WC point estimates (per 1 standard deviation increment) overlapped for all cancers. In this large Southern European study, a higher BMI was associated with increased risk of twelve cancers, including four hematological and head and neck (only among never smokers) cancers. Furthermore, BMI and WC showed comparable estimates of cancer risk associated with adiposity. Supplementary information accompanies this paper at 10.1186/s12916-020-01877-3

Residential Proximity to Urban Play Spaces and Childhood Overweight and Obesity in Barcelona, Spain: A Population-Based Longitudinal Study

Altres ajuts: La Marató de TV3, 201621-30Findings on the relationship between play spaces and childhood overweight and obesity are mixed and scarce. This study aimed to investigate the associations between residential proximity to play spaces and the risk of childhood overweight or obesity and potential effect modifiers. This longitudinal study included children living in the city of Barcelona identified in an electronic primary healthcare record database between 2011 and 2018 (N = 75,608). Overweight and obesity were defined according to the WHO standards and we used 300 m network buffers to assess residential proximity to play spaces. We calculated the risk of developing overweight or obesity using Cox proportional hazard models. A share of 29.4% of the study population developed overweight or obesity, but we did not find consistent associations between play space indicators and overweight or obesity. We did not find any consistent sign of effect modification by sex, and only some indications of the modifying role of area socioeconomic status and level of exposure. Although it is not possible to draw clear conclusions from our study, we call for cities to continue increasing and improving urban play spaces with an equitable, healthy, and child-friendly perspectiv

O expossoma humano desvendando o impacto do ambiente sobre a saúde: promessa ou realidade?

Considering the innovative nature of the approach to human exposome, we present the state of the art of studies on exposome, and discuss current challenges and perspectives in this area. Several reading and discussion activities were conducted by the Expossoma e Saúde do Trabalhador (eXsat – Group Exposome and Worker’s Health), with systematization of the literature in the area published between January 2005 and January 2017, available in the databases PubMed and Web of Science. This comment brings a thematic analysis to encourage the dissemination of the exposome approach for studies in the Public Health area.Levando em consideração a natureza inovadora da abordagem do expossoma humano, apresentamos o estado da arte dos estudos sobre expossoma, e discutimos os desafios e perspectivas atuais nessa área. Foram realizadas diversas atividades de leitura e discussão pelo grupo eXsat (Expossoma e Saúde do Trabalhador), com sistematização da literatura da área publicada entre janeiro de 2005 e janeiro de 2017, disponíveis nas bases de dados PubMed e Web of Science. O presente comentário traz uma análise da temática de forma a incentivar a disseminação da abordagem do expossoma nos estudos da área de Saúde Pública

CO Disrupts the Reduced H-Cluster of FeFe Hydrogenase. A Combined DFT and Protein Film Voltammetry Study

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Characterization of acute TLR-7 agonist-induced hemorrhagic myocarditis in mice by multiparametric quantitative cardiac magnetic resonance imaging.

Hemorrhagic myocarditis is a potentially fatal complication of excessive levels of systemic inflammation. It has been reported in viral infection, but is also possible in systemic autoimmunity. Epicutaneous treatment of mice with the Toll-like receptor 7 (TLR-7) agonist Resiquimod induces auto-antibodies and systemic tissue damage, including in the heart, and is used as an inducible mouse model of systemic lupus erythematosus (SLE). Here, we show that overactivation of the TLR-7 pathway of viral recognition by Resiquimod treatment of CFN mice induces severe thrombocytopenia and internal bleeding, which manifests most prominently as hemorrhagic myocarditis. We optimized a cardiac magnetic resonance (CMR) tissue mapping approach for the in vivo detection of diffuse infiltration, fibrosis and hemorrhages using a combination of T1, T2 and T2 * relaxation times, and compared results with ex vivo histopathology of cardiac sections corresponding to CMR tissue maps. This allowed detailed correlation between in vivo CMR parameters and ex vivo histopathology, and confirmed the need to include T2 * measurements to detect tissue iron for accurate interpretation of pathology associated with CMR parameter changes. In summary, we provide detailed histological and in vivo imaging-based characterization of acute hemorrhagic myocarditis as an acute cardiac complication in the mouse model of Resiquimod-induced SLE, and a refined CMR protocol to allow non-invasive longitudinal in vivo studies of heart involvement in acute inflammation. We propose that adding T2 * mapping to CMR protocols for myocarditis diagnosis improves diagnostic sensitivity and interpretation of disease mechanisms.This article has an associated First Person interview with the first author of the paper