ABSTRACT
Mayaro virus (MAYV) is an emerging arbovirus of the Americas that may cause a debilitating arthritogenic disease. The biology of MAYV is not fully understood and largely inferred from related arthritogenic alphaviruses. Here, we present the structure of MAYV at 4.4 Å resolution, obtained from a preparation of mature, infective virions. MAYV presents typical alphavirus features and organization. Interactions between viral proteins that lead to particle formation are described together with a hydrophobic pocket formed between E1 and E2 spike proteins and conformational epitopes specific of MAYV. We also describe MAYV glycosylation residues in E1 and E2 that may affect MXRA8 host receptor binding, and a molecular "handshake" between MAYV spikes formed by N262 glycosylation in adjacent E2 proteins. The structure of MAYV is suggestive of structural and functional complexity among alphaviruses, which may be targeted for specificity or antiviral activity.
Subject(s)
Alphavirus Infections/virology , Alphavirus/ultrastructure , Cryoelectron Microscopy , Mass Spectrometry , Alphavirus/immunology , Alphavirus Infections/immunology , Animals , Antibodies, Neutralizing , Chlorocebus aethiops , Glycosylation , Humans , Immunoglobulins , Membrane Proteins , Vero CellsABSTRACT
RATIONALE: The nematode Aphelenchoides besseyi is the causal agent of green stem and foliar retention, a soybean disease recently described in Brazil. This condition can reduce soybean yield by up to 100%. However, little is known about chemical interactions between the plant and pathogen. Therefore, this work aimed to investigate metabolites from healthy soybean roots and from soybean roots that were inoculated with A. besseyi. METHODS: A. besseyi were multiplied in vitro with Fusarium sp. colonies in Petri dishes for 25 days, and were axenically inoculated into hydroponics healthy soybean plants. The metabolites were extracted from the roots of healthy and A. besseyi-infected plants 16 days post-inoculation. These extracts were analyzed using an untargeted metabolomic method with an ultra-high-performance liquid chromatography/electrospray ionization /tandem mass spectrometry (UHPLC/ESI-MS/MS) and molecular networking approach. RESULTS: Roots from infected plants showed morphological alterations such as shrinkage, darkening, and arching. Similarly, they also showed an increased presence of flavonoids, compared with healthy roots. Compounds such as neobavaisoflavone, glycitin, genistin, and genistein were putatively identified and had greater intensity in inoculated roots. These compounds are linked to the defensive mechanisms in plants against nematodes. Moreover, coumaric acid, also exclusively putatively identified in inoculated roots, shows activity related to inhibition of root growth. CONCLUSIONS: Liquid chromatography, mass spectrometry, and molecular networking approaches proved to be a powerful tool for the metabolomic study of GSFR. This study showed metabolomics differences of protective substances in the roots, evidencing a quick response of the plant to the attack of A. besseyi.
Subject(s)
Glycine max/metabolism , Glycine max/parasitology , Metabolomics/methods , Plant Roots/parasitology , Tandem Mass Spectrometry/methods , Animals , Chromatography, High Pressure Liquid , Host-Parasite Interactions , Plant Diseases/parasitology , Plant Roots/metabolism , Secondary Metabolism , Tylenchida/pathogenicityABSTRACT
Objective: The aim of this study was to assess the knowledge, behaviour and practices regarding caries lesions, periodontal disease, preventive measures, diet and oral hygiene among public school students by using specific questionnaire and then guide them on the main educational and preventive methods for oral health. Material and Methods: A total of 376 students aged between 11 and 15 years old were evaluated. The students answered a questionnaire and watched a 10-minute educational video on tooth-brushing techniques, use of dental floss and diet. All the participants were given toothbrushes, dentifrice and dental floss. The resulting data were submitted to descriptive statistical analysis. Results: It was found that 54.26% of the school students were female, 95.21% had knowledge on caries lesions and only 15.96% know about periodontal disease. The surgeon-dentist was pointed out by 66.34% of the students as the responsible for guiding them on oral hygiene, with lack of hygiene being accounted for caries lesions and periodontal disease (64.09% and 38.30%, respectively). Toothbrush, dentifrice and dental floss were the most used resources for oral hygiene by 72.34% of the participants. Dental floss was used by 42.29% of the students, whereas 38.64% fail in doing so claiming they do not know how to use it. Conclusion: The school students showed knowledge on educational and preventive methods for oral health, but with some deficiencies; the majority of them were given guidelines on how to avoid oral problems by a surgeondentist; it is necessary to emphasise the importance of using dental floss in educational programs aimed at modifying the students' behaviour and practices regarding oral health. (AU)
Objetivo: O objetivo deste estudo foi avaliar o conhecimento, comportamento e práticas de escolares da Rede Pública de Ensino sobre cárie, doença periodontal, medidas preventivas, dieta e higiene bucal por meio de um questionário específico e, posteriormente orientá-los sobre os principais métodos educativos e preventivos em saúde bucal. Material e Métodos: Foram avaliados 376 estudantes com idade entre 11 e 15 anos. Os escolares responderam um questionário e assistiram um vídeo educativo com duração de 10 minutos sobre técnicas de escovação, utilização do fio dental e dieta. Todos os alunos participantes receberam uma escova, creme dental e fio dental. Os dados obtidos foram submetidos à análise estatística descritiva. Resultados: Os resultados mostraram que 54,26% dos escolares eram do gênero feminino, 95,21% apresentaram conhecimento sobre cárie e apenas 15,96% sobre doença periodontal. O Cirurgião Dentista foi apontado como responsável pela orientação sobre higienização bucal por 66,34% dos escolares, sendo a falta de higiene responsabilizada tanto pela etiologia da cárie como da doença periodontal (64,09% e 38,30%, respectivamente). Escova, creme dental e fio dental são os recursos mais utilizados para higienização bucal por 72,34% dos entrevistados. O fio dental é utilizado por 42,29% dos alunos, e 38,64% não o utilizam alegando que não sabem utilizar. Conclusão: Os escolares avaliados apresentam conhecimento sobre métodos educativos e preventivos em saúde bucal, com algumas deficiências; a maioria dos escolares teve acesso a orientações sobre como evitar problemas bucais por meio do Cirurgião Dentista; é necessário enfatizar a importância do uso do fio dental nos programas educativos para modificar o comportamento e as práticas dos escolares em relação à saúde bucal.(AU)
