Starvation-induced autophagy modulates spermatogenesis and sperm quality in Nile tilapia.

Spermatogenesis is a finely regulated process that involves the interaction of several cellular mechanisms to ensure the proper development and maturation of germ cells. This study assessed autophagy contribution and its relation to apoptosis in fish spermatogenesis during starvation. To that end, Nile tilapia males were subjected to 0 (control), 7, 14, 21, and 28 days of starvation to induce autophagy. Testes samples were obtained for analyses of spermatogenesis by histology, electron microscopy, immunohistochemistry, and western blotting. Sperm quality was assessed using a computer-assisted sperm analysis (CASA) system. Data indicated a significant reduction in gonadosomatic index, seminiferous tubule area, and spermatozoa proportion in fish subject to starvation compared to the control group. Immunoblotting revealed a reduction of Bcl2 and Beclin 1 associated with increased Bax and Caspase-3, mainly after 21 and 28 days of starvation. LC3 and P62 indicated reduced autophagic flux in these starvation times. Immunolabeling for autophagic and apoptotic proteins occurred in all development stages of the germ cells, but protein expression varied throughout starvation. Beclin 1 and Cathepsin D decreased while Bax and Caspase-3 increased in spermatocytes, spermatids, and spermatozoa after 21 and 28 days. Autophagic and lysosomal proteins colocalization indicated the fusion of autophagosomes with lysosomes and lysosomal degradation in spermatogenic cells. The CASA system indicated reduced sperm motility and velocity in animals subjected to 21 and 28 days of starvation. Altogether, the data support autophagy acting at different spermatogenesis stages in Nile tilapia, with decreased autophagy and increased apoptosis after 21 and 28 days of starvation, which results in a decrease in the spermatozoa number and sperm quality.

Baseline gene signatures of reactogenicity to Ebola vaccination: a machine learning approach across multiple cohorts.

Introduction: The rVSVDG-ZEBOV-GP (Ervebo®) vaccine is both immunogenic and protective against Ebola. However, the vaccine can cause a broad range of transient adverse reactions, from headache to arthritis. Identifying baseline reactogenicity signatures can advance personalized vaccinology and increase our understanding of the molecular factors associated with such adverse events. Methods: In this study, we developed a machine learning approach to integrate prevaccination gene expression data with adverse events that occurred within 14 days post-vaccination. Results and Discussion: We analyzed the expression of 144 genes across 343 blood samples collected from participants of 4 phase I clinical trial cohorts: Switzerland, USA, Gabon, and Kenya. Our machine learning approach revealed 22 key genes associated with adverse events such as local reactions, fatigue, headache, myalgia, fever, chills, arthralgia, nausea, and arthritis, providing insights into potential biological mechanisms linked to vaccine reactogenicity.

Relação entre hábitos alimentares, peso corporal e saúde intestinal em indivíduos adultos / Relationship between eating habits, body weight, and intestinal health in adults

Introdução: A disbiose pode estar relacionada à hábitos alimentares ruins e alterações metabólicas que podem contribuir para o excesso de peso. Objetivo: Avaliar as escolhas alimentares que modulam a microbiota intestinal e a associação entre a saúde intestinal e o peso corporal de indivíduos adultos. Método: Estudo analítico, correlacional-descritivo e transversal realizado com 99 participantes, adultos, de ambos os sexos. Utilizou-se um Questionário Sociodemográfico e de Frequência Alimentar para coletar dados sociodemográficos, peso corporal, altura, frequência de consumo de alimentos fontes de prebióticos e probióticos e o Questionário de Rastreamento Metabólico (QRM), para investigar a saúde intestinal. O estudo ocorreu de forma online, via Google forms, sendo divulgado através das redes sociais (Facebook, Instagram, WhatsApp). Realizou-se uma análise descritiva dos dados e para associação entre variáveis empregou-se o teste Qui-quadrado de Pearson. Resultados: Do total de participantes, 74,7% eram mulheres. Quanto à classificação do Índice de Massa Corporal (IMC), 60,6% apresentaram eutrofia 24,2% sobrepeso e 9,1% algum grau de obesidade. Os alimentos fontes de probióticos e prebióticos mais consumidos foram queijo, iogurte, leites fermentados e banana, maçã, aveia, respectivamente. Porém, são alimentos que não fazem parte do consumo diário para a maioria dos participantes. Não houve diferença significativa entre a associação com IMC com sexo, escore final do QRM e somatório final dos sintomas gastrointestinais (p=0,76, p=0,29, p=0,70), respectivamente. Conclusão: Nota-se uma baixa frequência de consumo de alimentos que auxiliam na saúde intestinal. No entanto, não foi constatado que o peso corporal exerce influência na composição da microbiota intestinal.

Introducción: La disbiosis puede estar relacionada con malos hábitos alimentarios y alteraciones metabólicas que pueden contribuir al sobrepeso. Objetivo: Evaluar las elecciones alimentarias que modulan la microbiota intestinal y la asociación entre la salud intestinal y el peso corporal en personas adultas. Método: Estudio analítico, correlacional-descriptivo y transversal realizado con 99 personas participantes adultas de ambos sexos. Se utilizó un cuestionario sociodemográfico y de frecuencia alimentaria para recoger datos sociodemográficos, peso corporal, altura, frecuencia de consumo de fuentes alimentarias de prebióticos y probióticos y el Cuestionario de Seguimiento Metabólico para investigar la salud intestinal. El estudio se realizó online, a través de formularios de Google, siendo difundido a través de redes sociales (Facebook, Instagram, WhatsApp). Se realizó un análisis descriptivo de los datos y para la asociación entre variables se empleó el test Chi-cuadrado de Pearson. Resultados: Del total de participantes, el 74.7 % fueron mujeres. En cuanto a la clasificación del Índice de Masa Corporal, el 60.6 % eran personas eutróficas, el 24.2 % con sobrepeso y el 9.1% personas obesas. Los alimentos fuente de probióticos y prebióticos más consumidos fueron el queso, el yogur, las leches fermentadas, el plátano, la manzana y la avena. Sin embargo, se trata de alimentos que no forman parte del consumo diario de la mayoría de los participantes. No hubo diferencias significativas entre la asociación del Índice de Masa Corporal con el sexo, la puntuación final del Cuestionario de Seguimiento Metabólico y la suma final de síntomas gastrointestinales (p=0.76, p=0.29, p=0.70), respectivamente. Conclusiones: Se observa una baja frecuencia de consumo de alimentos que ayudan a la salud intestinal. Sin embargo, no se encontró que el peso corporal ejerza influencia sobre la composición de la microbiota intestinal.

Introduction: Dysbiosis may be related to poor eating habits and metabolic changes that can contribute to being overweight. Objective: To evaluate the food choices that modulate the gut microbiota and the association between gut health and body weight in adult individuals. Method: Analytical, correlational-descriptive, cross-sectional study conducted with 99 adult participants of both sexes. A Sociodemographic and Food Frequency Questionnaire was used to collect sociodemographic data, body weight, height, and frequency of consumption of food sources of prebiotics and probiotics; and the Metabolic Tracking Questionnaire was applied to investigate gut health. The study took place online, via Google Forms, and was disseminated through social media (Facebook, Instagram, WhatsApp). A descriptive analysis of the data was performed and for association between variables, the Pearson's Chi-square test was used. Results: Of the total number of participants, 74.7% were women. As for the classification of Body Mass Index, 60.6% were eutrophic, 24.2% were overweight, and 9.1% were somewhat obese. The most consumed probiotic and prebiotic food sources were cheese, yogurt, fermented kinds of milk; and banana, apple, and oatmeal, respectively. However, these are foods that are not part of the daily consumption for most participants. There was no significant difference between the association of the Body Mass Index with the sex of the participants or the final Metabolic Tracking Questionnaire score and the final sum of gastrointestinal symptoms (p=0.76, p=0.29, p=0.70). Conclusion: A low frequency of consumption of foods that aid intestinal health is noted. However, body weight was not found to influence the composition of the gut microbiota.

Serum biomarkers in patients with unilateral or bilateral active pulmonary tuberculosis: Immunological networks and promising diagnostic applications.

The present observational study was designed to characterize the integrative profile of serum soluble mediators to describe the immunological networks associated with clinical findings and identify putative biomarkers for diagnosis and prognosis of active tuberculosis. The study population comprises 163 volunteers, including 84 patients with active pulmonary tuberculosis/(TB), and 79 controls/(C). Soluble mediators were measured by multiplexed assay. Data analysis demonstrated that the levels of CCL3, CCL5, CXCL10, IL-1ß, IL-6, IFN-γ, IL-1Ra, IL-4, IL-10, PDGF, VEGF, G-CSF, IL-7 were increased in TB as compared to C. Patients with bilateral pulmonary involvement/(TB-BI) exhibited higher levels of CXCL8, IL-6 and TNF with distinct biomarker signatures (CCL11, CCL2, TNF and IL-10) as compared to patients with unilateral infiltrates/(TB-UNI). Analysis of biomarker networks based in correlation power graph demonstrated small number of strong connections in TB and TB-BI. The search for biomarkers with relevant implications to understand the pathogenetic mechanisms and useful as complementary diagnosis tool of active TB pointed out the excellent performance of single analysis of IL-6 or CXCL10 and the stepwise combination of IL-6 â†’ CXCL10 (Accuracy = 84 %; 80 % and 88 %, respectively). Together, our finding demonstrated that immunological networks of serum soluble biomarkers in TB patients differ according to the unilateral or bilateral pulmonary involvement and may have relevant implications to understand the pathogenetic mechanisms involved in the clinical outcome of Mtb infection.

The gene regulatory network of Staphylococcus aureus ST239-SCCmecIII strain Bmb9393 and assessment of genes associated with the biofilm in diverse backgrounds.

Introduction: Staphylococcus aureus is one of the most prevalent and relevant pathogens responsible for a wide spectrum of hospital-associated or community-acquired infections. In addition, methicillin-resistant Staphylococcus aureus may display multidrug resistance profiles that complicate treatment and increase the mortality rate. The ability to produce biofilm, particularly in device-associated infections, promotes chronic and potentially more severe infections originating from the primary site. Understanding the complex mechanisms involved in planktonic and biofilm growth is critical to identifying regulatory connections and ways to overcome the global health problem of multidrug-resistant bacteria. Methods: In this work, we apply literature-based and comparative genomics approaches to reconstruct the gene regulatory network of the high biofilm-producing strain Bmb9393, belonging to one of the highly disseminating successful clones, the Brazilian epidemic clone. To the best of our knowledge, we describe for the first time the topological properties and network motifs for the Staphylococcus aureus pathogen. We performed this analysis using the ST239-SCCmecIII Bmb9393 strain. In addition, we analyzed transcriptomes available in the literature to construct a set of genes differentially expressed in the biofilm, covering different stages of the biofilms and genetic backgrounds of the strains. Results and discussion: The Bmb9393 gene regulatory network comprises 1,803 regulatory interactions between 64 transcription factors and the non-redundant set of 1,151 target genes with the inclusion of 19 new regulons compared to the N315 transcriptional regulatory network published in 2011. In the Bmb9393 network, we found 54 feed-forward loop motifs, where the most prevalent were coherent type 2 and incoherent type 2. The non-redundant set of differentially expressed genes in the biofilm consisted of 1,794 genes with functional categories relevant for adaptation to the variable microenvironments established throughout the biofilm formation process. Finally, we mapped the set of genes with altered expression in the biofilm in the Bmb9393 gene regulatory network to depict how different growth modes can alter the regulatory systems. The data revealed 45 transcription factors and 876 shared target genes. Thus, the gene regulatory network model provided represents the most up-to-date model for Staphylococcus aureus, and the set of genes altered in the biofilm provides a global view of their influence on biofilm formation from distinct experimental perspectives and different strain backgrounds.

A Systematic Strategy to Find Potential Therapeutic Targets for Pseudomonas aeruginosa Using Integrated Computational Models.

Pseudomonas aeruginosa is an opportunistic human pathogen that has been a constant global health problem due to its ability to cause infection at different body sites and its resistance to a broad spectrum of clinically available antibiotics. The World Health Organization classified multidrug-resistant Pseudomonas aeruginosa among the top-ranked organisms that require urgent research and development of effective therapeutic options. Several approaches have been taken to achieve these goals, but they all depend on discovering potential drug targets. The large amount of data obtained from sequencing technologies has been used to create computational models of organisms, which provide a powerful tool for better understanding their biological behavior. In the present work, we applied a method to integrate transcriptome data with genome-scale metabolic networks of Pseudomonas aeruginosa. We submitted both metabolic and integrated models to dynamic simulations and compared their performance with published in vitro growth curves. In addition, we used these models to identify potential therapeutic targets and compared the results to analyze the assumption that computational models enriched with biological measurements can provide more selective and (or) specific predictions. Our results demonstrate that dynamic simulations from integrated models result in more accurate growth curves and flux distribution more coherent with biological observations. Moreover, identifying drug targets from integrated models is more selective as the predicted genes were a subset of those found in the metabolic models. Our analysis resulted in the identification of 26 non-host homologous targets. Among them, we highlighted five top-ranked genes based on lesser conservation with the human microbiome. Overall, some of the genes identified in this work have already been proposed by different approaches and (or) are already investigated as targets to antimicrobial compounds, reinforcing the benefit of using integrated models as a starting point to selecting biologically relevant therapeutic targets.

Leisure-time physical activity in São Paulo adults: a trend analysis from 2006 to 2016. / Nível de atividade física no lazer em adultos paulistanos: uma análise de tendência de 2006 a 2016.

OBJECTIVE: To investigate the temporal trend of practicing physical exercise and sports during leisure time in adults in São Paulo between 2006 to 2016. METHODS: Time series analysis study using the VIGITEL System. Adding up the number of people who participated each year, a total 21,357 people were studied. Analyzes of the physical exercises and sports practiced during leisure time (yes or no) stratified by sex, age and education were performed. The prevalences and the differences for all of the years were calculated using the Prains-Winster regression. RESULTS: Practice of physical exercises or sports increased by 7.9 percentage points in the period (p = 0.003) (from 39.9% 95%CI 37.4 - 42.4 to 47.8% 95%CI 45.2 - 50.4). There was a significant increase for women (p = 0.011), for people between 18-24 years old (p = 0.001), 25-34 years old (p = 0.003), 45-54 years old (p = 0.003), and for people with up to eight years of schooling (p = 0.010). There was a decrease in walking and playing soccer and there was an increase in doing gymnastics. CONCLUSION: There was an increase in the practice of physical exercise and sports during leisure time in adults from São Paulo. These increases were observed mainly in women, in people between 18 and 34 years old, between 45 and 54 years old, and in people with up to eight years of schooling. These results are important, as they have shown an increase in general and in more vulnerable groups, and may be related to environmental changes and interventions that have occurred in the city in the last 15 years.

OBJETIVO: Investigar a tendência temporal da prática de exercícios físicos e esportes no lazer de adultos em São Paulo entre 2006 e 2016. MÉTODOS: Estudo de análise de série temporal que utilizou a base de dados do Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (VIGITEL). Somando-se todos os anos, foram estudadas 21.357 pessoas. Foram realizadas análises das práticas de exercícios físicos ou esportes no lazer (sim ou não) estratificadas por sexo, idade e escolaridade. Calcularam-se as prevalências e as diferenças para todos os anos por meio da regressão de Prains-Winster. RESULTADOS: A prática de exercícios físicos ou esportes aumentou em 7,9 pontos percentuais no período (p = 0,003) (foi de 39,9% [intervalo de confiança de 95% - IC95% 37,4 ‒ 42,4] para 47,8% [IC95% 45,2 ‒ 50,4]). Houve aumento significativo para as mulheres (p = 0,011), para as pessoas entre 18 e 24 anos (p = 0,001), entre 25 e 34 anos (p = 0,003), entre 45 e 54 anos (p = 0,003) e para pessoas com até oito anos de escolaridade (p = 0,010). Houve queda na prática de caminhada e futebol e aumento na prática das ginásticas. CONCLUSÃO: Verificou-se aumento na prática de exercícios físicos ou esportes no lazer em adultos de São Paulo. Esse crescimento foi observado principalmente em mulheres, nos jovens entre 18 e 34 anos, em indivíduos entre 45 e 54 anos e em pessoas com até oito anos de estudo. Esses resultados são importantes, pois mostraram aumento em geral e em grupos mais vulneráveis e podem estar relacionados com mudanças ambientais e intervenções ocorridas na cidade nos últimos 15 anos.

Zebrafish studies on the vaccine candidate to COVID-19, the Spike protein: Production of antibody and adverse reaction

Establishing new experimental animal models to assess the safety and immune response to the antigen used in the development of COVID-19 vaccine is an imperative issue. Based on the advantages of using zebrafish as a model in research, herein we suggest doing this to test the safety of the putative vaccine candidates and to study immune response against the virus. We produced a recombinant N-terminal fraction of the Spike SARS-CoV-2 protein and injected it into adult female zebrafish. The specimens generated humoral immunity and passed the antibodies to the eggs. However, they presented adverse reactions and inflammatory responses similar to severe cases of human COVID-19. The analysis of the structure and function of zebrafish and human Angiotensin-converting enzyme 2, the main human receptor for virus infection, presented remarkable sequence similarities. Moreover, bioinformatic analysis predicted protein-protein interaction of the Spike SARS-CoV-2 fragment and the Toll-like receptor pathway. It might help in the choice of future therapeutic pharmaceutical drugs to be studied. Based on the in vivo and in silico results presented here, we propose the zebrafish as a model for translational research into the safety of the vaccine and the immune response of the vertebrate organism to the SARS-CoV-2 virus.

Characterization of a SPM-1 metallo-beta-lactamase-producing Pseudomonas aeruginosa by comparative genomics and phenotypic analysis.

Pseudomonas aeruginosa is one of the most common pathogens related to healthcare-associated infections. The Brazilian isolate, named CCBH4851, is a multidrug-resistant clone belonging to the sequence type 277. The antimicrobial resistance mechanisms of the CCBH4851 strain are associated with the presence of the bla[Formula: see text] gene, encoding a metallo-beta-lactamase, in combination with other exogenously acquired genes. Whole-genome sequencing studies focusing on emerging pathogens are essential to identify key features of their physiology that may lead to the identification of new targets for therapy. Using both Illumina and PacBio sequencing data, we obtained a single contig representing the CCBH4851 genome with annotated features that were consistent with data reported for the species. However, comparative analysis with other Pseudomonas aeruginosa strains revealed genomic differences regarding virulence factors and regulatory proteins. In addition, we performed phenotypic assays that revealed CCBH4851 is impaired in bacterial motilities and biofilm formation. On the other hand, CCBH4851 genome contained acquired genomic islands that carry transcriptional factors, virulence and antimicrobial resistance-related genes. Presence of single nucleotide polymorphisms in the core genome, mainly those located in resistance-associated genes, suggests that these mutations may also influence the multidrug-resistant behavior of CCBH4851. Overall, characterization of Pseudomonas aeruginosa CCBH4851 complete genome revealed the presence of features that strongly relates to the virulence and antibiotic resistance profile of this important infectious agent.

Nível de atividade física no lazer em adultos paulistanos: uma análise de tendência de 2006 a 2016 / Leisure-time physical activity in São Paulo adults: a trend analysis from 2006 to 2016

RESUMO: Objetivo: Investigar a tendência temporal da prática de exercícios físicos e esportes no lazer de adultos em São Paulo entre 2006 e 2016. Métodos: Estudo de análise de série temporal que utilizou a base de dados do Sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico (VIGITEL). Somando-se todos os anos, foram estudadas 21.357 pessoas. Foram realizadas análises das práticas de exercícios físicos ou esportes no lazer (sim ou não) estratificadas por sexo, idade e escolaridade. Calcularam-se as prevalências e as diferenças para todos os anos por meio da regressão de Prains-Winster. Resultados: A prática de exercícios físicos ou esportes aumentou em 7,9 pontos percentuais no período (p = 0,003) (foi de 39,9% [intervalo de confiança de 95% - IC95% 37,4 ‒ 42,4] para 47,8% [IC95% 45,2 ‒ 50,4]). Houve aumento significativo para as mulheres (p = 0,011), para as pessoas entre 18 e 24 anos (p = 0,001), entre 25 e 34 anos (p = 0,003), entre 45 e 54 anos (p = 0,003) e para pessoas com até oito anos de escolaridade (p = 0,010). Houve queda na prática de caminhada e futebol e aumento na prática das ginásticas. Conclusão: Verificou-se aumento na prática de exercícios físicos ou esportes no lazer em adultos de São Paulo. Esse crescimento foi observado principalmente em mulheres, nos jovens entre 18 e 34 anos, em indivíduos entre 45 e 54 anos e em pessoas com até oito anos de estudo. Esses resultados são importantes, pois mostraram aumento em geral e em grupos mais vulneráveis e podem estar relacionados com mudanças ambientais e intervenções ocorridas na cidade nos últimos 15 anos.

ABSTRACT: Objective: To investigate the temporal trend of practicing physical exercise and sports during leisure time in adults in São Paulo between 2006 to 2016. Methods: Time series analysis study using the VIGITEL System. Adding up the number of people who participated each year, a total 21,357 people were studied. Analyzes of the physical exercises and sports practiced during leisure time (yes or no) stratified by sex, age and education were performed. The prevalences and the differences for all of the years were calculated using the Prains-Winster regression. Results: Practice of physical exercises or sports increased by 7.9 percentage points in the period (p = 0.003) (from 39.9% 95%CI 37.4 - 42.4 to 47.8% 95%CI 45.2 - 50.4). There was a significant increase for women (p = 0.011), for people between 18-24 years old (p = 0.001), 25-34 years old (p = 0.003), 45-54 years old (p = 0.003), and for people with up to eight years of schooling (p = 0.010). There was a decrease in walking and playing soccer and there was an increase in doing gymnastics. Conclusion: There was an increase in the practice of physical exercise and sports during leisure time in adults from São Paulo. These increases were observed mainly in women, in people between 18 and 34 years old, between 45 and 54 years old, and in people with up to eight years of schooling. These results are important, as they have shown an increase in general and in more vulnerable groups, and may be related to environmental changes and interventions that have occurred in the city in the last 15 years.

Neurofeedback Training for Cognitive and Motor Function Rehabilitation in Chronic Stroke: Two Case Reports.

Stroke is a debilitating neurological condition which usually results in the abnormal electrical brain activity and the impairment of sensation, motor, or cognition functions. In this context, neurofeedback training, i.e., a non-invasive and relatively low cost technique that contributes to neuroplasticity and behavioral performance, might be promising for stroke rehabilitation. We intended to explore neurofeedback training on a 63-year-old male patient and a 77-year-old female patient with chronic stroke. Both of them had suffered from an ischemic stroke for rather long period (more than 3 years) and could not gain further improvement by traditional therapy. The neurofeedback training was designed to enhance alpha activity by 15 sessions distributed over 2 months, for the purpose of overall cognitive improvement and hopefully also motor function improvement for the female patient. We found that the two patients showed alpha enhancement during NFT compared to eyes open baseline within most sessions. Furthermore, both patients reduced their anxiety and depression level. The male patient showed an evolution in speech pattern in terms of naming, sentences completion and verbal fluency, while the female patient improved functionality of the march. These results suggested that alpha neurofeedback training could provide a spectrum of improvements, providing new hope for chronic stroke patients who could not gain further improvements through traditional therapies.

Gene regulatory network inference and analysis of multidrug-resistant Pseudomonas aeruginosa.

BACKGROUND: Healthcare-associated infections caused by bacteria such as Pseudomonas aeruginosa are a major public health problem worldwide. Gene regulatory networks (GRN) computationally represent interactions among regulatory genes and their targets. They are an important approach to help understand bacterial behaviour and to provide novel ways of overcoming scientific challenges, including the identification of potential therapeutic targets and the development of new drugs. OBJECTIVES: The goal of this study was to reconstruct the multidrug-resistant (MDR) P. aeruginosa GRN and to analyse its topological properties. METHODS: The methodology used in this study was based on gene orthology inference using the reciprocal best hit method. We used the genome of P. aeruginosa CCBH4851 as the basis of the reconstruction process. This MDR strain is representative of the sequence type 277, which was involved in an endemic outbreak in Brazil. FINDINGS: We obtained a network with a larger number of regulatory genes, target genes and interactions as compared to the previously reported network. Topological analysis results are in accordance with the complex network representation of biological processes. MAIN CONCLUSIONS: The properties of the network were consistent with the biological features of P. aeruginosa. To the best of our knowledge, the P. aeruginosa GRN presented here is the most complete version available to date.

Autophagy and Cathepsin D mediated apoptosis contributing to ovarian follicular atresia in the Nile tilapia.

Follicular atresia is a hormonally controlled degenerative process involving apoptosis of the somatic and germ cells. Since different signaling pathways can induce cell death, the aim of the present study was to investigate cell death signaling and crosstalk between autophagic, apoptotic, and lysosomal proteins during follicular atresia in Nile tilapia. For this, females were kept in controlled conditions for 21 days, and ovary samples were collected weekly. The atretic follicles (AF) were analyzed in three regression phases: Early, advanced, and late. Under electron microscopy, the follicular cells exhibited numerous protein synthesis organelles in the early AF. Immunoreactivity for Bcl2, Beclin1, Lc3, and Cathepsin D increased significantly in advanced AF (p < .001), when follicular cells were in intense yolk phagocytosis. In this phase, autophagosomes and autolysosomes were frequently observed. In the late AF, follicular cells had a markedly electron-lucid cytoplasm and immunoreactivity for Bax and TUNEL assay indicated an elevated apoptosis rate. Colocalisation of Lamp1/Cathepsin D and Lc3/Caspase-3 suggests dynamic crosstalk between the autophagy, apoptosis, and lysosome pathways. Taken together, the data indicate that autophagy plays a role in the homeostasis and clearance of the follicular cells preceding Cathepsin D mediated apoptosis during follicular atresia in Nile tilapia.

Integrative approach detects natural hybridization of sympatric lambaris species and emergence of infertile hybrids.

Despite its relevance for ecology, evolution and conservation of species, natural hybridization and hybrids biology are still poorly studied in freshwater fish. Here, we tested the hypothesis that sympatric species Astyanax paranae and A. fasciatus are able to interbreed in the natural environment and presented evidence for the first record of hybridization between these species. We analyzed anatomical traits, gametogenesis, reproductive biology, and genetic variations of the COI and S7 genes of both species and putative hybrids. Intermediate morphometric and meristic features were observed in hybrids when compared to A. paranae and A. fasciatus. Overlap in reproductive season was showed for these species, with greater reproductive activity from August to January, but hybrids did not present any sign of gonadal maturation. Oogonia and perinucleolar follicles as well as spermatogonia and primary spermatocytes were found in hybrids, but previtellogenic and vitellogenic follicles, spermatids, and spermatozoa were absent. Moreover, several alterations in gametogenesis were detected, such as interrupted meiosis in both males and females, vacuolated and degenerated germ cells, increased interstitial tissue, and presence of immune cells. Molecular analyses supported the hypothesis of hybridization between A. paranae and A. fasciatus. Overall, our multidisciplinary approach also provides strong evidence that hybrids are infertile.

Expression patterns and immunolocalisation of IGF-I and IGF-II in male and female gonads of the Neotropical characid fish Astyanax fasciatus.

The insulin-like growth factor (IGF) system plays important roles in fish reproduction, but the expression pattern and cellular location of IGF-I and IGF-II during gonadal maturation are uncertain. The present study reports a stage-specific assessment of gonadal expression levels and immunolocalisation of IGF-I and IGF-II in Astyanax fasciatus, a characid fish from South America. Adult fish in different maturity stages were caught in the Furnas Reservoir, Grande River, Brazil. Gonad samples were processed for histology, immunohistochemistry, and ELISA for IGF-I and IGF-II. Ovarian levels of IGF-I were low during ripening and ripe stages, higher in totally spent, and then decreased in resting. Levels of IGF-II increased during ovarian maturation, reaching significantly higher values at stage totally spent. In males, IGF-I levels followed gonadal maturation, with higher values in ripening and ripe stages, whereas IGF-II levels showed higher values in stage ripening and partially spent. A positive correlation was found between IGF-I and gonadosomatic index (GSI) for males (r = 0.59), while females showed a negative correlation (r = - 0.43), but IGF-II showed no correlation to GSI. IGF-I was expressed mainly in oogonia nests whereas IGF-II stained the follicular cells in the perinucleolar follicles, cortical vesicles in the previtellogenic follicles, and oogonia nests. In males, IGF-I was evident in spermatogonia and spermatocytes while IGF-II stained Sertoli cells surrounding spermatids cysts and spermatogonia in late stages. Together, these findings support a hypothesis that the balance between IGF-I and IGF-II levels is important in the regulation of gonad maturation in Astyanax fasciatus.

Gene regulatory network inference and analysis of multidrug-resistant Pseudomonas aeruginosa

BACKGROUND Healthcare-associated infections caused by bacteria such as Pseudomonas aeruginosa are a major public health problem worldwide. Gene regulatory networks (GRN) computationally represent interactions among regulatory genes and their targets. They are an important approach to help understand bacterial behaviour and to provide novel ways of overcoming scientific challenges, including the identification of potential therapeutic targets and the development of new drugs. OBJECTIVES The goal of this study was to reconstruct the multidrug-resistant (MDR) P. aeruginosa GRN and to analyse its topological properties. METHODS The methodology used in this study was based on gene orthology inference using the reciprocal best hit method. We used the genome of P. aeruginosa CCBH4851 as the basis of the reconstruction process. This MDR strain is representative of the sequence type 277, which was involved in an endemic outbreak in Brazil. FINDINGS We obtained a network with a larger number of regulatory genes, target genes and interactions as compared to the previously reported network. Topological analysis results are in accordance with the complex network representation of biological processes. MAIN CONCLUSIONS The properties of the network were consistent with the biological features of P. aeruginosa. To the best of our knowledge, the P. aeruginosa GRN presented here is the most complete version available to date.

Effect of polymerization method and fabrication method on occlusal vertical dimension and occlusal contacts of complete-arch prosthesis.

PURPOSE: This study evaluated the dimensional stability of a complete-arch prosthesis processed by conventional method in water bath or microwave energy and polymerized by two different curing cycles. MATERIALS AND METHODS: Forty maxillary complete-arch prostheses were randomly divided into four groups (n = 10): MW1 - acrylic resin cured by one microwave cycle; MW2 - acrylic resin cured by two microwave cycles: WB1 - conventional acrylic resin polymerized using one curing cycle in a water bath; WB2 - conventional acrylic resin polymerized using two curing cycles in a water bath. For evaluation of dimensional stability, occlusal vertical dimension (OVD) and area of contact points were measured in two different measurement times: before and after the polymerization method. A digital caliper was used for OVD measurement. Occlusal contact registration strips were used between maxillary and mandibular dentures to measure the contact points. The images were measured using the software IpWin32, and the differences before and after the polymerization methods were calculated. The data were statistically analyzed using the one-way ANOVA and Tukey test (α = .05). RESULTS: he results demonstrated significant statistical differences for OVD between different measurement times for all groups. MW1 presented the highest OVD values, while WB2 had the lowest OVD values (P<.05). No statistical differences were found for area of contact points among the groups (P=.7150). CONCLUSION: The conventional acrylic resin polymerized using two curing cycles in a water bath led to less difference in OVD of complete-arch prosthesis.

Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge.

Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries.

DNA-based identification reveals illegal trade of threatened shark species in a global elasmobranch conservation hotspot.

Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 samples being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN - International Union for Conservation of Nature; CITES - Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of samples, with Sphyrna mokarran being the fourth most common species among samples. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.