Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
Arch Public Health ; 82(1): 76, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38769567

RESUMO

BACKGROUND: Fuzzy cognitive mapping (FCM) is a graphic technique to describe causal understanding in a wide range of applications. This practice review summarises the experience of a group of participatory research specialists and trainees who used FCM to include stakeholder views in addressing health challenges. From a meeting of the research group, this practice review reports 25 experiences with FCM in nine countries between 2016 and 2023. RESULTS: The methods, challenges and adjustments focus on participatory research practice. FCM portrayed multiple sources of knowledge: stakeholder knowledge, systematic reviews of literature, and survey data. Methodological advances included techniques to contrast and combine maps from different sources using Bayesian procedures, protocols to enhance the quality of data collection, and tools to facilitate analysis. Summary graphs communicating FCM findings sacrificed detail but facilitated stakeholder discussion of the most important relationships. We used maps not as predictive models but to surface and share perspectives of how change could happen and to inform dialogue. Analysis included simple manual techniques and sophisticated computer-based solutions. A wide range of experience in initiating, drawing, analysing, and communicating the maps illustrates FCM flexibility for different contexts and skill bases. CONCLUSIONS: A strong core procedure can contribute to more robust applications of the technique while adapting FCM for different research settings. Decision-making often involves choices between plausible interventions in a context of uncertainty and multiple possible answers to the same question. FCM offers systematic and traceable ways to document, contrast and sometimes to combine perspectives, incorporating stakeholder experience and causal models to inform decision-making. Different depths of FCM analysis open opportunities for applying the technique in skill-limited settings.

2.
Front Plant Sci ; 14: 1237054, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37662181

RESUMO

Losses due to disease and climate change are among the most important issues currently facing crop production. It is therefore important to establish the impact of climate change, and particularly of high carbon dioxide (hCO2), on plant immunity in cereals, which provide 60% of human calories. The aim of this study was to determine if hCO2 impacts Brachypodium distachyon immunity, a model plant for temperate cereals. Plants were grown in air (430 ppm CO2) and at two high CO2 conditions, one that is relevant to projections within the coming century (1000 ppm) and a concentration sufficient to saturate photosynthesis (3000 ppm). The following measurements were performed: phenotyping and growth, salicylic acid contents, pathogen resistance tests, and RNAseq analysis of the transcriptome. Improved shoot development was observed at both 1000 and 3000 ppm. A transcriptomic analysis pointed to an increase in primary metabolism capacity under hCO2. Alongside this effect, up-regulation of genes associated with secondary metabolism was also observed. This effect was especially evident for the terpenoid and phenylpropanoid pathways, and was accompanied by enhanced expression of immunity-related genes and accumulation of salicylic acid. Pathogen tests using the fungus Magnaporthe oryzae revealed that hCO2 had a complex effect, with enhanced susceptibility to infection but no increase in fungal development. The study reveals that immunity in B. distachyon is modulated by growth at hCO2 and allows identification of pathways that might play a role in this effect.

3.
Soc Sci Med ; 335: 116230, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37716184

RESUMO

The COVID-19 pandemic has led to an unprecedented global crisis. It has exposed and exacerbated weaknesses in public health systems worldwide, particularly with regards to reaching the most vulnerable populations, disproportionately impacted by the pandemic. The objective of our study was to examine whether and how social inequalities in health (SIH) were considered in the design and planning of public health responses to COVID-19 in jurisdictions of Brazil, Canada, France, and Mali. This article reports on a qualitative multiple case study of testing and contact tracing interventions in regions with high COVID-19 incidence in each country, namely: Manaus (Brazil), Montréal (Canada), Île-de-France (France), and Bamako (Mali). We conducted interviews with 108 key informants involved in these interventions in the four jurisdictions, focusing on the first and second waves of the pandemic. We analyzed our data thematically using a theoretical bricolage framework. Our analysis suggests that the lack of a common understanding of SIH among all actors involved and the sense of urgency brought by the pandemic eclipsed the prioritization of SIH in the initial responses. The pandemic increased intersectoral collaboration, but decision-making power was often unequal between Ministries of Health and other actors in each jurisdiction. Various adaptations to COVID-19 interventions were implemented to reach certain population groups, therefore improving the accessibility, availability, and acceptability of testing and contact tracing. Our study contributes to identifying lessons learned from the current pandemic, namely that the ways in which SIH are understood shape how interventions are planned; that having clear guidelines on how to integrate SIH into public health interventions could lead to more inclusive pandemic responses; that for intersectoral collaboration to be fruitful, there needs to be sufficient resources and equitable decision-making power between partners; and that interventions must be flexible to respond to emerging needs while considering long-standing structural inequalities.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Busca de Comunicante , Pandemias/prevenção & controle , Mali , Brasil/epidemiologia , Fatores Socioeconômicos
4.
BMJ Open ; 13(6): e069340, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37277224

RESUMO

INTRODUCTION: As the number of people living in cities increases worldwide, particularly in low-income and middle-income countries (LMICs), urban health is a growing priority of public and global health. Rapid unplanned urbanisation in LMICs has exacerbated inequalities, putting the urban poor at increased risk of ill health due to difficult living conditions in cities. Collaboration with communities in research is a key strategy for addressing the challenges they face. The objective of this scoping review is, therefore, to identify factors that influence the participation of urban communities from LMICs in public and global health research. METHODS AND ANALYSIS: We will develop a search strategy with a health librarian to explore the following databases: MEDLINE, Embase, Web of Science, Cochrane, Global Health and CINAHL. We will use MeSH terms and keywords exploring the concepts of 'low-income and middle-income countries', 'community participation in research' and 'urban settings' to look at empirical research conducted in English or French. There will be no restriction in terms of dates of publication. Two independent reviewers will screen and select studies, first based on titles and abstracts, and then on full text. Two reviewers will extract data. We will summarise the results using tables and fuzzy cognitive mapping. ETHICS AND DISSEMINATION: This scoping review is part of a larger project to be approved by the University of Montréal's Research Ethics Committee for Science and Health in Montréal (Canada), and the Institutional Review Board of the James P Grant School of Public Health at BRAC University in Dhaka (Bangladesh). Results from the review will contribute to a participatory process seeking to combine scientific evidence with experiential knowledge of stakeholders in Dhaka to understand how to better collaborate with communities for research. The review could contribute to a shift toward research that is more inclusive and beneficial for communities.


Assuntos
Países em Desenvolvimento , Saúde Global , Humanos , Bangladesh , Participação da Comunidade , Cidades , Projetos de Pesquisa , Literatura de Revisão como Assunto
6.
Artigo em Inglês | MEDLINE | ID: mdl-37047915

RESUMO

Social media usage is growing globally, with an exponential increase in low- and middle-income countries. Social media changes the ways in which information-sharing occurs, intensifying the population's exposure to misinformation, including fake news. This has important repercussions for global health. The spread of fake news can undermine the implementation of evidence-based interventions and weaken the credibility of scientific expertise. This is particularly worrisome in countries, such as Brazil, in a sociopolitical context characterized by a lack of popular trust in public institutions. In this project report, we describe our experience with the spread of fake news through the social media platform WhatsApp during the implementation of a cluster randomized controlled trial aimed at reducing dengue incidence in children in Fortaleza (Brazil). During initial visits to selected clusters, the research team was met with resistance. Then, soon after data collection started, fake news began circulating about the study. As a result, the research team developed strategies to dispel suspicion and further promote the study. However, the climate of violence and mistrust, coupled with the COVID-19 pandemic, forced the interruption of the study in 2019. The lessons learned from our experience in Fortaleza can be useful to other researchers and practitioners implementing large-scale interventions in this era of health-related misinformation.


Assuntos
COVID-19 , Dengue , Mídias Sociais , Criança , Humanos , COVID-19/epidemiologia , Saúde Global , Brasil/epidemiologia , Pandemias , Desinformação , Dengue/epidemiologia
7.
Can J Public Health ; 114(3): 346-357, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36940083

RESUMO

OBJECTIVE: In Canada and globally, the COVID-19 pandemic has increased social inequalities in health (SIH), furthering the vulnerability of certain groups and communities. Contact-tracing is a cornerstone intervention with COVID-19 prevention and control programs. The aim of this study was to describe whether and how SIH were considered during the design of the COVID-19 contact-tracing intervention in Montreal. METHODS: This study is part of the multi-country research program HoSPiCOVID, looking at the resilience of public health systems during the COVID-19 pandemic. A descriptive qualitative study was carried out in Montreal, based on a "bricolage" conceptual framework describing the consideration for SIH in intervention and policy design. Qualitative data were collected using semi-structured interviews with 16 public health practitioners, recruited using both purposive and snowball sampling. Data were analyzed thematically, both inductively and deductively. RESULTS: According to participants, SIH were not initially considered during the design of the contract-tracing intervention in Montreal. The participants were frustrated by the Minister of Health's initial resistance to integrating SIH into their public health response. However, adaptations were gradually made to better meet the needs of underserved populations. CONCLUSION: There is a need for a clear and common vision of SIH within the public health system. Decision-makers need to consider SIH prior to designing public health interventions in order for these not to further increase SIH in the future, especially in the face of a health crisis.


RéSUMé: OBJECTIF: Au Canada et dans le monde, la pandémie de COVID-19 a augmenté les inégalités sociales de santé (ISS), aggravant la vulnérabilité de certains groupes et communautés. Le suivi des contacts est une intervention fondamentale des programmes de prévention et de contrôle de la COVID-19. L'objectif de cette étude était de décrire si et comment les ISS ont été prises en compte lors de la conception de l'intervention de suivi des contacts pour la COVID-19 à Montréal. MéTHODES: Cette étude fait partie du programme de recherche multi-pays HoSPiCOVID, portant sur la résilience des systèmes de santé publique pendant la pandémie de COVID-19. Une étude qualitative descriptive a été menée à Montréal, sur la base d'un cadre conceptuel « bricolage ¼ décrivant la prise en compte des ISS dans la conception des interventions et des politiques. Des données qualitatives ont été recueillies au moyen d'entrevues semi-structurés avec 16 praticiens de la santé publique, recrutés par échantillonnage raisonné et en boule de neige. Les données ont été analysées de manière thématique, de façon inductive et déductive. RéSULTATS: Selon les participants, les ISS n'ont pas été initialement prises en compte lors de la conception de l'intervention de suivi des contacts à Montréal. Les professionnels de santé publique ont déploré le manque de volonté du Ministère de la Santé d'intégrer les ISS dans la réponse de santé publique. Toutefois, des adaptations ont été progressivement apportées pour mieux répondre aux besoins des populations vulnérables. CONCLUSION: Il est nécessaire d'avoir une vision claire et commune des ISS au sein du système de santé. Les décideurs doivent prendre en compte activement les ISS pour que celles-ci soient mieux conceptualisées, et que les interventions de santé publique n'aggravent pas les ISS, surtout en période de crise sanitaire.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Busca de Comunicante , Pandemias/prevenção & controle , Quebeque/epidemiologia , Fatores Socioeconômicos
8.
Cult Health Sex ; 25(8): 1070-1083, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36153729

RESUMO

The burden of maternal mortality in sub-Saharan Africa is the highest in the world. As high fertility rates present an increased risk to women's health, programmes and services have been put in place to increase access to family planning. Several studies have identified sociocultural factors as limiting access to family planning, including male resistance and women's low decision-making power. However, these studies have often used a behavioural approach that anchors barriers to access in women's attitudes or motivations. In 2019, a qualitative evaluation of a family planning programme using a behavioural approach was conducted in rural Uganda, focusing on women's attitudes and unmet needs. With hindsight, we realised that our evaluation was insufficient to adequately capture barriers that extend beyond women's motivations. This paper shares three case studies that we analysed using a structural health vulnerabilities approach. Our analysis highlights political, economic, social and cultural structures that can impede access to family planning. Using a structural health vulnerabilities approach, we identify structural barriers which have their roots in the local realities women face and propose context-specific structural recommendations. Finally, we contrast our initial results with findings the case studies presented to highlight the relevance of taking structural vulnerabilities into account in future family planning programme evaluation and women's sexual and reproductive health studies.


Assuntos
Serviços de Planejamento Familiar , Saúde da Mulher , Humanos , Masculino , Feminino , Uganda , Comportamento Sexual
9.
Front Plant Sci ; 13: 1017890, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36531385

RESUMO

Wheat is one of the most important crops in the world. Its production can be influenced by a diversity of beneficial and pathogenic rhizospheric microbes, including fungi. Amongst them, beneficial Trichoderma spp. can be used as alternatives to chemical fertilizers, as they are cheap and harmless to the environment. Our study aimed to isolate, identify, and characterize Trichoderma spp. from Lebanon associated with wheat. Two Trichoderma strains belonging to T. afroharzianum, and T. guizhouense species, were isolated and found to be endophytes, enhancing root growth and producing Indole-3-acetic acid. Inoculation also improved seedling development, and increased plant growth and yield. Furthermore, the two strains inhibit Fusarium growth in vitro. These Trichoderma spp. have thus the capacity to be used as organic fertilizers for wheat.

10.
Health Soc Care Community ; 30(6): e5998-e6008, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36148516

RESUMO

In Uganda, almost half of children under 5 years old suffer from undernutrition. Undernutrition, a common form of malnutrition in children, encompasses stunting, wasting and underweight. The causes of child undernutrition are complex, suggesting that interventions to tackle malnutrition must be multifaceted. Furthermore, limited access to healthcare for vulnerable populations restricts the potential of hospital-based strategies. Community-based management of acute malnutrition (CMAM), which includes nutritional counselling, ready-to-use therapeutic foods and the outpatient management of malnutrition by caregivers, is recognised as an effective approach for children's recovery. However, evaluations of CMAM programs are largely based on biomedical and behavioural health models, failing to incorporate structural factors that influence malnutrition management. The objective of this evaluation was to understand the factors influencing malnutrition management in a CMAM program in rural Uganda, using the socioecological model to assess the multilevel determinants of outpatient malnutrition management. This evaluation used qualitative methods to identify factors related to caregivers, healthcare providers and societal structures that influence children's outpatient care. Data were collected at a community health clinic in 2019 through observations and interviews with caregivers of malnourished children. We observed 14 caregiver-provider encounters and interviewed 15 caregivers to examine factors hindering outpatient malnutrition management. Data were thematically analysed informed by the socioecological model. Findings showed that caregivers had a limited understanding of malnutrition. Counselling offered to caregivers was inconsistent and insufficient. Poverty and gender inequality limited caregivers' access to healthcare and their ability to care for their children. Factors at the caregiver and healthcare levels interacted with societal factors to shape malnutrition management. Results suggest that CMAM programs would benefit from providing holistic interventions to tackle the structural barriers to children's care. Using a socioecological approach to program evaluation could help move beyond individual determinants to address the social dynamics shaping malnutrition management in low- and middle-income countries.


Assuntos
Transtornos da Nutrição Infantil , Desnutrição , Criança , Humanos , Lactente , Pré-Escolar , Transtornos da Nutrição Infantil/epidemiologia , Transtornos da Nutrição Infantil/terapia , Uganda/epidemiologia , Desnutrição/terapia , População Rural , Atenção à Saúde
11.
BMC Public Health ; 22(1): 749, 2022 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-35422030

RESUMO

BACKGROUND: Evidence continues to demonstrate that certain marginalised populations are disproportionately affected by COVID-19. While many studies document the impacts of COVID-19 on social inequalities in health, none has examined how public health responses to the pandemic have unfolded to address these inequities in Canada. The purpose of our study was to assess how social inequalities in health were considered in the design and planning of large-scale COVID-19 testing programs in Montréal (Québec, Canada). METHODS: Part of the multicountry study HoSPiCOVID, this article reports on a qualitative case study of large-scale testing for COVID-19 in Montréal. We conducted semi-structured interviews with 19 stakeholders involved in planning large-scale testing or working with vulnerable populations during the pandemic. We developed interview guides and a codebook using existing literature on policy design and planning, and analysed data deductively and inductively using thematic analysis in NVivo. RESULTS: Our findings suggest that large-scale COVID-19 testing in Montréal did not initially consider social inequalities in health in its design and planning phases. Considering the sense of urgency brought by the pandemic, participants noted the challenges linked to the uptake of an intersectoral approach and of a unified vision of social inequalities in health. However, adaptations were gradually made to large-scale testing to improve its accessibility, acceptability, and availability. Actors from the community sector, among others, played an important role in supporting the health sector to address the needs of specific subgroups of the population. CONCLUSIONS: These findings contribute to the reflections on the lessons learned from COVID-19, highlighting that public health programs must tackle structural barriers to accessing healthcare services during health crises. This will be necessary to ensure that pandemic preparedness and response, including large-scale testing, do not further increase social inequalities in health.


Assuntos
Teste para COVID-19 , COVID-19 , COVID-19/epidemiologia , Serviços de Saúde , Humanos , Pesquisa Qualitativa , Fatores Socioeconômicos
12.
Front Plant Sci ; 12: 662025, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868356

RESUMO

Fusarium Head Blight (FHB) is a cereal disease caused primarily by the ascomycete fungus Fusarium graminearum with public health issues due to the production of mycotoxins including deoxynivalenol (DON). Genetic resistance is an efficient protection means and numerous quantitative trait loci have been identified, some of them related to the production of resistance metabolites. In this study, we have functionally characterized the Brachypodium distachyon BdCYP711A29 gene encoding a cytochrome P450 monooxygenase (CYP). We showed that BdCYP711A29 belongs to an oligogenic family of five members. However, following infection by F. graminearum, BdCYP711A29 is the only copy strongly transcriptionally induced in a DON-dependent manner. The BdCYP711A29 protein is homologous to the Arabidopsis thaliana MAX1 and Oryza sativa MAX1-like CYPs representing key components of the strigolactone biosynthesis. We show that BdCYP711A29 is likely involved in orobanchol biosynthesis. Alteration of the BdCYP711A29 sequence or expression alone does not modify plant architecture, most likely because of functional redundancy with the other copies. B. distachyon lines overexpressing BdCYP711A29 exhibit an increased susceptibility to F. graminearum, although no significant changes in defense gene expression were detected. We demonstrate that both orobanchol and exudates of Bd711A29 overexpressing lines stimulate the germination of F. graminearum macroconidia. We therefore hypothesize that orobanchol is a susceptibility factor to FHB.

13.
Phytopathology ; 111(7): 1129-1136, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33245256

RESUMO

Trichoderma gamsii T6085 has been investigated for many years as a beneficial isolate for use in the biocontrol of Fusarium head blight (FHB) of wheat caused primarily by Fusarium graminearum. Previous work focused on application of T6085 to wheat spikes at anthesis, whereas application to soil before or at sowing has received limited attention. In the present study, the competitive ability of T6085 on plant residues against F. graminearum was investigated. Results showed a significant reduction of wheat straw colonization by the pathogen and of the development of perithecia, not only when T6085 was applied alone but also in the presence of a F. oxysporum isolate (7121), well known as a natural competitor on wheat plant residues. T6085 was able to endophytically colonize wheat roots, resulting in internal colonization of the radical cortex area, without reaching the vascular system, as confirmed by confocal microscopy. This intimate interaction with the plant resulted in a significant increase of the expression of the plant defense-related genes PAL1 and PR1. Taken together, competitive ability, endophytic behavior, and host resistance induction represent three important traits that can be of great use in the application of T6085 against FHB not only on spikes at anthesis but potentially also in soil before or at sowing.


Assuntos
Fusarium , Trichoderma , Hypocreales , Doenças das Plantas , Triticum
14.
Front Plant Sci ; 9: 1853, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619419

RESUMO

Plant uridine diphosphate (UDP)-glucosyltransferases (UGT) catalyze the glucosylation of xenobiotic, endogenous substrates and phytotoxic agents produced by pathogens such as mycotoxins. The Bradi5g03300 UGT-encoding gene from the model plant Brachypodium distachyon was previously shown to confer tolerance to the mycotoxin deoxynivalenol (DON) through glucosylation into DON 3-O-glucose (D3G). This gene was shown to be involved in early establishment of quantitative resistance to Fusarium Head Blight, a major disease of small-grain cereals. In the present work, using a translational biology approach, we identified and characterized a wheat candidate gene, Traes_2BS_14CA35D5D, orthologous to Bradi5g03300 on the short arm of chromosome 2B of bread wheat (Triticum aestivum L.). We showed that this UGT-encoding gene was highly inducible upon infection by a DON-producing Fusarium graminearum strain while not induced upon infection by a strain unable to produce DON. Transformation of this wheat UGT-encoding gene into B. distachyon revealed its ability to confer FHB resistance and root tolerance to DON as well as to potentially conjugate DON into D3G in planta and its impact on total DON reduction. In conclusion, we provide a UGT-encoding candidate gene to include in selection process for FHB resistance.

15.
Plant Physiol ; 172(1): 559-74, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27378816

RESUMO

Fusarium head blight (FHB) is a cereal disease caused by Fusarium graminearum, a fungus able to produce type B trichothecenes on cereals, including deoxynivalenol (DON), which is harmful for humans and animals. Resistance to FHB is quantitative, and the mechanisms underlying resistance are poorly understood. Resistance has been related to the ability to conjugate DON into a glucosylated form, deoxynivalenol-3-O-glucose (D3G), by secondary metabolism UDP-glucosyltransferases (UGTs). However, functional analyses have never been performed within a single host species. Here, using the model cereal species Brachypodium distachyon, we show that the Bradi5g03300 UGT converts DON into D3G in planta. We present evidence that a mutation in Bradi5g03300 increases root sensitivity to DON and the susceptibility of spikes to F. graminearum, while overexpression confers increased root tolerance to the mycotoxin and spike resistance to the fungus. The dynamics of expression and conjugation suggest that the speed of DON conjugation rather than the increase of D3G per se is a critical factor explaining the higher resistance of the overexpressing lines. A detached glumes assay showed that overexpression but not mutation of the Bradi5g03300 gene alters primary infection by F. graminearum, highlighting the involvement of DON in early steps of infection. Together, these results indicate that early and efficient UGT-mediated conjugation of DON is necessary and sufficient to establish resistance to primary infection by F. graminearum and highlight a novel strategy to promote FHB resistance in cereals.


Assuntos
Brachypodium/genética , Glicosiltransferases/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Sequência de Aminoácidos , Sequência de Bases , Brachypodium/enzimologia , Resistência à Doença/genética , Fusarium/metabolismo , Fusarium/fisiologia , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glucosídeos/metabolismo , Glicosiltransferases/metabolismo , Interações Hospedeiro-Patógeno , Cinética , Mutação , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Raízes de Plantas/microbiologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tricotecenos/metabolismo , Difosfato de Uridina/metabolismo
16.
BMC Genomics ; 15: 629, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-25063396

RESUMO

BACKGROUND: Fusarium Head Blight (FHB) caused primarily by Fusarium graminearum (Fg) is one of the major diseases of small-grain cereals including bread wheat. This disease both reduces yields and causes quality losses due to the production of deoxynivalenol (DON), the major type B trichothecene mycotoxin. DON has been described as a virulence factor enabling efficient colonization of spikes by the fungus in wheat, but its precise role during the infection process is still elusive. Brachypodium distachyon (Bd) is a model cereal species which has been shown to be susceptible to FHB. Here, a functional genomics approach was performed in order to characterize the responses of Bd to Fg infection using a global transcriptional and metabolomic profiling of B. distachyon plants infected by two strains of F. graminearum: a wild-type strain producing DON (Fgdon+) and a mutant strain impaired in the production of the mycotoxin (Fgdon-). RESULTS: Histological analysis of the interaction of the Bd21 ecotype with both Fg strains showed extensive fungal tissue colonization with the Fgdon+ strain while the florets infected with the Fgdon- strain exhibited a reduced hyphal extension and cell death on palea and lemma tissues. Fungal biomass was reduced in spikes inoculated with the Fgdon- strain as compared with the wild-type strain. The transcriptional analysis showed that jasmonate and ethylene-signalling pathways are induced upon infection, together with genes encoding putative detoxification and transport proteins, antioxidant functions as well as secondary metabolite pathways. In particular, our metabolite profiling analysis showed that tryptophan-derived metabolites, tryptamine, serotonin, coumaroyl-serotonin and feruloyl-serotonin, are more induced upon infection by the Fgdon+ strain than by the Fgdon- strain. Serotonin was shown to exhibit a slight direct antimicrobial effect against Fg. CONCLUSION: Our results show that Bd exhibits defense hallmarks similar to those already identified in cereal crops. While the fungus uses DON as a virulence factor, the host plant preferentially induces detoxification and the phenylpropanoid and phenolamide pathways as resistance mechanisms. Together with its amenability in laboratory conditions, this makes Bd a very good model to study cereal resistance mechanisms towards the major disease FHB.


Assuntos
Brachypodium/microbiologia , Fusarium/fisiologia , Perfilação da Expressão Gênica , Metabolômica , Tricotecenos/biossíntese , Antifúngicos/farmacologia , Brachypodium/genética , Brachypodium/metabolismo , Brachypodium/fisiologia , Fusarium/efeitos dos fármacos , Fusarium/metabolismo , Interações Hospedeiro-Patógeno , Serotonina/farmacologia , Transdução de Sinais/genética , Especificidade da Espécie
17.
Mol Plant Microbe Interact ; 26(7): 781-92, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23550529

RESUMO

Plant small-molecule UDP-glycosyltransferases (UGT) glycosylate a vast number of endogenous substances but also act in detoxification of metabolites produced by plant-pathogenic microorganisms. The ability to inactivate the Fusarium graminearum mycotoxin deoxynivalenol (DON) into DON-3-O-glucoside is crucial for resistance of cereals. We analyzed the UGT gene family of the monocot model species Brachypodium distachyon and functionally characterized two gene clusters containing putative orthologs of previously identified DON-detoxification genes from Arabidopsis thaliana and barley. Analysis of transcription showed that UGT encoded in both clusters are highly inducible by DON and expressed at much higher levels upon infection with a wild-type DON-producing F. graminearum strain compared with infection with a mutant deficient in DON production. Expression of these genes in a toxin-sensitive strain of Saccharomyces cerevisiae revealed that only two B. distachyon UGT encoded by members of a cluster of six genes homologous to the DON-inactivating barley HvUGT13248 were able to convert DON into DON-3-O-glucoside. Also, a single copy gene from Sorghum bicolor orthologous to this cluster and one of three putative orthologs of rice exhibit this ability. Seemingly, the UGT genes undergo rapid evolution and changes in copy number, making it difficult to identify orthologs with conserved substrate specificity.


Assuntos
Brachypodium/enzimologia , Fusarium/patogenicidade , Glicosiltransferases/metabolismo , Doenças das Plantas/microbiologia , Tricotecenos/metabolismo , Sequência de Aminoácidos , Brachypodium/genética , Fusarium/química , Dosagem de Genes , Regulação da Expressão Gênica de Plantas , Ordem dos Genes , Glucosídeos/metabolismo , Glicosiltransferases/genética , Dados de Sequência Molecular , Família Multigênica , Mutação , Micotoxinas/genética , Micotoxinas/metabolismo , Oryza/enzimologia , Oryza/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sorghum/enzimologia , Sorghum/genética , Especificidade da Espécie , Sintenia
18.
J Affect Disord ; 145(3): 370-7, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23102862

RESUMO

BACKGROUND: Studies indicate that a dysfunctional attributional style, problem-solving deficits and hopelessness place youths at risk of developing suicidal thoughts and engaging in suicidal behaviour. However, in the realm of suicidality in adolescent, no study has examined the linkages between these three cognitive variables and suicidal ideation in non-clinical samples while taking into account the moderating role of gender on the relationships and controlling for depression. METHODS: In this community study of 712 adolescents 14-18 years of age, through a multivariate approach, the interaction between the cognitive variables, depression and gender was examined with depression controlled in the analyses. RESULTS: Problem-solving deficits and hopelessness proved predictive of such ideation whether or not depressive symptoms were controlled in the analyses. Negative problem orientation/avoidant style was more predictive of ideation in boys than in girls. On the other hand, hopelessness was more predictive for girls than boys. LIMITATIONS: Results were based on a convenience community sample of adolescents and a cross-sectional survey. CONCLUSIONS: Results suggest that a unique explanatory model of the suicide process in adolescence that fails to take account of gender would be ill informed. Suicide prevention strategies should be differentiated according to gender with a stronger emphasis in hopelessness in female adolescents, and problem-solving deficits in male adolescents.


Assuntos
Comportamento do Adolescente/psicologia , Transtornos Cognitivos/psicologia , Ideação Suicida , Adolescente , Estudos Transversais , Depressão/psicologia , Emoções , Feminino , Humanos , Masculino , Resolução de Problemas , Fatores de Risco , Fatores Sexuais , Inquéritos e Questionários
19.
Mol Plant Pathol ; 13(9): 1149-55, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22897438

RESUMO

High-throughput methods are needed for functional genomics analysis in Fusarium culmorum, the cause of crown and foot rot on wheat and a type B trichothecene producer. Our aim was to develop and test the efficacy of a double-component system based on the ability of the impala transposase to transactivate the miniature inverted-repeat transposable element mimp1 of Fusarium oxysporum. We report, for the first time, the application of a tagging system based on a heterologous transposon and of splinkerette-polymerase chain reaction to identify mimp1 flanking regions in the filamentous fungus F. culmorum. Similar to previous observations in Fusarium graminearum, mimp1 transposes in F. culmorum by a cut-and-paste mechanism into TA dinucleotides, which are duplicated on insertion. mimp1 was reinserted in open reading frames in 16.4% (i.e. 10 of 61) of the strains analysed, probably spanning throughout the entire genome of F. culmorum. The effectiveness of the mimp1/impala double-component system for gene tagging in F. culmorum was confirmed phenotypically for a putative aurofusarin gene. This system also allowed the identification of two genes putatively involved in oxidative stress-coping capabilities in F. culmorum, as well as a sequence specific to this fungus, thus suggesting the valuable exploratory role of this tool.


Assuntos
Elementos de DNA Transponíveis/genética , Fusarium/genética , Sequências Repetidas Invertidas/genética , Triticum/microbiologia , Southern Blotting , Genes Fúngicos/genética , Mutagênese Insercional/genética
20.
Mol Pharm ; 9(6): 1803-11, 2012 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-22510056

RESUMO

In vitro drug release studies remain indispensable in the development of drug delivery systems, even if correlations between in vitro and in vivo results are often imperfect. In this work, an improved in vitro analysis method for studying in situ-forming lipid-based implants was developed. More specifically, lipase was found to be an essential additive for evidencing differences in drug release kinetics from organogels of different amino acid-based organogelators, organogelator concentrations, drug loadings, and volumes. Lipases are thought to participate in the degradation of and release from amino acid-based organogel implants in vivo. Our experimental conditions allowed for the rapid and reliable screening of in vitro parameters that may be optimized to slow or accelerate drug release, once preliminary in vivo data are available.


Assuntos
Antibacterianos/química , Cefalosporinas/química , Géis/química , Lipase/genética , Sistemas de Liberação de Medicamentos , Cinética , Óleo de Cártamo/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...