In silico characterization of microRNAs-like sequences in the genome of Paracoccidioides brasiliensis

Eukaryotic cells have different mechanisms of post-transcriptional regulation. Among these mechanisms, microRNAs promote regulation of targets by cleavage or degradation of the mRNA. Fungi of the Paracoccidioides complex are the etiological agents of the main systemic mycosis of Latin America. These fungi present a plasticity to adapt and survive in different conditions, and the presence of microRNAs-like molecules could be part of the mechanisms that provide such plasticity. MicroRNAs produced by the host influence the progression of this mycosis in the lungs besides regulating targets involved in apoptosis in macrophage, activation of T and B cells and the production of cytokines. Therefore, this work analyzed the presence of regions in the genome of this fungus with a potential to encode microRNAs-like molecules. Here we show by analysis of sequence similarity the presence of 18 regions, putatively coding for microRNAs-like molecules in the Paracoccidioides brasiliensis genome. We also described the conservation of dicer and argonaut proteins and the cognate transcripts induced in the yeast parasitic phase. This work represents a starting point for the analysis of the presence of those molecules in the morphological stages of the fungus and their role in fungal development

Phytochemical screening, cytotoxicity and acute toxicity of Annona vepretorum Mart (Annonaceae) leaf extracts

Purpose: To investigate the phytochemistry, cytotoxicity and acute toxicity of leaf extracts from Annona vepretorum.Methods: The crude extracts were obtained by maceration with hexane and  methanol. The crude methanol extract was suspended in a 3:7 (v/v) mixture of methanol (MeOH) and water (H2O) and partitioned with hexane, chloroform (CHCl3) and ethyl acetate (AcOEt) in ascending order of polarity to obtain the respective  extracts. In the investigation of phytochemical profile, the extracts were evaluated on thin layer chromatography (TLC) plates of silica gel. Cytotoxicity was tested using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assays against tumor cell lines, viz,HCT-116 (colon), SF-295 (brain), HL-60 (leukemic) and Sarcoma-180. Acute toxicity study was performed by administration of a single oral dose of 2 g/kg body weight of the extracts to mice and the animals were observed for 14 days.Results: Phytochemical screening results showed that A. vepretorum extracts contain alkaloids, flavonoids and terpenes. Methanol and chloroform extracts exhibited high cytotoxic activity against HCT-116, HL-60 and Sarcoma-180. Moreover, the extracts displayed low toxicity in mice, as no deaths and pronounced toxic effects were observed.Conclusion: A. vepretorum contains a variety of secondary metabolites which may confer on this species high cytotoxic activity. In addition, the oral administration of the extracts produced low toxicity in mice.Keywords: Annonaceae, Annona vepretorum, Phytochemistry, Tumor cell lines, Acute toxicit

Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin Photoaging

Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.This research was supported by national funds through FCT, Foundation for Science and Technology, within the scope of UIDB/04423/2020 and UIDP/04423/2020 under the project PTDC/SAU-PUB/28736/2017 (reference POCI-01-0145-FEDER-028736), cofinanced by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds, as well as CHIRALBIOACTIVE-PI-3RL-IINFACTS-2019, and supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2019). Thanks are also due to FCT, the European Union, QREN, FEDER, COMPETE, by funding cE3c center (Ref. UID/BIA/00329/2019) and Direcao Regional da Ciencia e Tecnologia (Azores Government) by funding Azorean Biodiversity Group.info:eu-repo/semantics/publishedVersio

Situação vacinal dos discentes da Faculdade de Medicina da UFJF–MG

Health professionals are exposed to various occupational risks, with the greatest impact from biological hazards due to direct contact with potentially contaminated organic materials. Besides adopting universal biosafety measures, adequate immunization coverage must be achieved in this context, with educational initiatives playing a crucial role in the process. This was a cross-sectional observational study of undergraduates (n = 136) at the Medical School of the Federal University in Juiz de Fora to assess their immunization status and biological risk perceptions. Eighty-nine students (65.4%) reported a complete vaccination schedule. Ninety-seven (71.3%) had received full immunization against hepatitis B and 99 (72.8%) against tetanus. Eighty-six (63.2%) reported having received immunization advice during the course. Seventy-three (53.7%) had already been exposed to potentially contaminated material during their academic activities, and 97 (71.3%) used personal protective equipment (PPE) in these contexts. We identified missed immunization doses against hepatitis B and tetanus, a situation that exposes medical students to unnecessary risks. Immunization advice was insufficient. The significant rate of exposure to biological hazards and the unsatisfactory use of PPE call for greater attention to accident prevention.Os profissionais da área de saúde estão expostos a vários tipos de riscos ocupacionais, sendo o de maior impacto o risco biológico, devido ao contato direto com material orgânico potencialmente contaminado. A manutenção da situação vacinal atualizada é uma das ferramentas que devem ser empregadas neste contexto, além da adoção de medidas universais de biossegurança, sendo a educação fundamental neste processo. Avaliamos a situação vacinal e a percepção sobre risco biológico dos discentes da Faculdade de Medicina da UFJF em estudo observacional transversal (n = 136 alunos). Oitenta e nove alunos (65,4%) referiram estar com o cartão vacinal atualizado. Noventa e sete alunos (71,3%) receberam o esquema da hepatite B, e 99 (72,8%) o do tétano. Oitenta e seis 86 alunos (63,2%) declararam ter recebido orientação sobre imunização durante o curso. Setenta e três alunos (53,7%) já foram expostos a material potencialmente contaminado em suas atividades acadêmicas, e 97 deles (71,3%) usam equipamentos de proteção individual (EPI) nestas. Identificamos falhas na imunização (hepatite B e tétano), expondo os discentes a riscos desnecessários. A orientação relativa à imunização se mostrou insuficiente. A significativa taxa de exposição a risco biológico e o insatisfatório uso de EPIs verificados demandam maior atenção, a fim de prevenir acidentes

Resistividade em solos: efeito dos índices físicos e condições de análise / Soil resistivity: phisical indexes and analysis conditions influence

A resistividade elétrica é um parâmetro amplamente utilizado na avaliação da corrosividade dos solos. Entretanto, algumas metodologias de análise em laboratório têm divergência nos procedimentos e resultados obtidos, o que pode impactar na correta avaliação da propriedade e sua consequente correlação com a resistência à corrosão. Neste estudo foi realizado uma revisão dos ensaios de resistividade de solo propostos pelos procedimentos adotados pelas normas ABNT NBR 16254-1:2014 (Anexo C), ASTM G-187-15 e ASTM G-187-15 modificada pela adoção de cálculos dos índices físicos para obtenção do grau de saturação da amostra de solo. A avaliação dos resultados indicou que o os procedimentos realizados pela norma ASTM-G187-15 e pelo mesmo procedimento modificado, adotando os índices físicos foram compatíveis. Já o ensaio realizado pela norma ABNT NBR 16254-1:2014 (Anexo C) não teve resultados satisfatórios

A Galeria da Escola Guignard: vivências para a construção de conhecimento

Neste artigo, apresenta-se a experiência do projeto educativo Arte Contemporânea e Educação Artística na Galeria da Escola Guignard – Universidade do Estado de Minas Gerais (UEMG). Aborda-se a formação do aluno de Educação Artística e Artes Plásticas com vista ao mercado de trabalho, objetivando abrir caminhos para a discussão a respeito das mudanças pelas quais passa o ensino de arte no Brasil. São apresentados relatos e reflexões de alunos e professores sobre o projeto

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors