465 research outputs found

    Interacções de estirpes de Aspergillus flavus não-toxígenas com Aspergillus parasiticus na produção de aflatoxinas

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    Aflatoxins production is affected by abiotic, biotic and genetic parameters. Eugenesic and dysgenetic condition for aflatoxinogenesis are relatively well studied, such as: the influence of temperature, pH, Aw, Oxigen tension, osmotic pression, organic and inorganic nutrients, substance with fungistatic effects: however there are relatively few knowledge about endogenous regulator mechanisms, the kinetic of the anabolism and the interaction between the productive moulds and remaining microflora holding in eutrophying substrates. The main objective of this study is to evaluate biotic interaction between five indigenous strains of A. flavus, confirmed non-toxigenic, and a productive strain (A. parasiticus ATCC 15 517), cultured simultaneously on two substrates: one natural (cracked corn) and a synthetic one, modified Czapeck-Dox broth. Aflatoxins quantifications were performed by HPLC at 8th and 12th days. Results of those interactive cultures showed that all strains were synergic, increasing aflatoxins production in a range between 5.6 and 106.5% over the control values, with an exception registered on one of the strains cultured in cracked corn at the 12th day, where the production decreased (-7.6%).A produção de aflatoxinas é afetada por parâmetros abióticos, bióticos e genéticos. As condições eugenésicas e disgenésicas da aflatoxinogênese estão relativamente bem estudadas, tal como as influências ecológicas (temperatura, pH, Aw, tensão de oxigênio, pressão osmótica, nutrientes e substâncias fungistáticas). Contudo, é muito escasso o conhecimento relativo aos mecanismos reguladores endógenos, à cinética do anabolismo e à interação dos fungos produtores com a restante microflora presente em substratos eutrofizantes. O principal objetivo deste estudo é avaliar a interação de cinco estirpes indígenas de A. flavus, comprovadamente atoxígenas, com uma geneticamente apta (A. parasiticus ATCC 15517), cultivadas simultaneamente em dois substratos: um natural (milho triturado) e outro sintético (Caldo de Czapeck-Dox Modificado). A quantificação das aflatoxinas foi efetuada no 8º e 12º dias de incubação, por Cromatografia Líquida de Alta Resolução (HPLC). Os resultados demonstraram que todas as estirpes foram sinérgicas, aumentando o rendimento da produção entre 5,6 e 106,5%, quando comparados com os valores das testemunhas

    Screening of Aflatoxin B1 in Laboratory Rat Feed

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    Many hazards can interfere with the safety of the feeding stuffs intended to provide nutrients to experimental  animals. Chemical and biological contaminants of laboratory animal feed can be a problem for toxicological  and immunological research. Aflatoxin B1 (AFB1) is a secondary toxic metabolite, produced by  the ubiquitous fungal genera, Aspergillus. AFB1 is particularly dangerous for health, inducing cancer of the  urinary tract or liver carcinoma. The aim of this preliminary screening was to evaluate the presence of AFB1  in 31 samples of laboratory rat feed using a method validated in-house, then separated by High Pressure  Liquid Chromatography (HPLC) coupled to a fluorescence detector. The detection limit (limit of detection:  LOD) and the quantification limit (LOQ) were 0.2 and 0.4 ìg/kg respectively. Recoveries ranged from 58.0  to 74.5% for spiked samples. The immunoaffinity approach was significantly faster than methods employing  conventional chromatography clean-up (Sep-Pak Classic Florisil and Sep-Pak ClassicC18 cartridges).  Aflatoxins were not detected in any analysed sample.

    The effects of large-sided soccer training games and pitch size manipulation on time–motion profile, spatial exploration and surface area: Tactical opportunities

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    Analysis of the physical, technical and physiological variations induced through the use of different soccer game formats have been widely discussed. However, the coaching justification for the specific use of certain game formats based on individual and collective spatial awareness is unclear. As a result, the purpose of this study was to analyze 11 versus 11 game formats conducted across two pitch sizes (half-size: 54 m × 68 m vs full-size: 108 m × 68 m) to identify effects of time–motion profiles, individual exploration behavior and collective organization. A total of 10 amateur soccer players from the same team (23.39 ± 3.91 years old) participated in this study. Data position of the players was used to calculate the spatial exploration index and the surface area. Distances covered in different speeds were used to observe the time–motion profile. The full-size pitch dimensions significantly contributed to greater distances covered via running (3.86–5.52 m s−1) and sprinting (>5.52 m s−1). Total distance and number of sprints were also significantly greater in the full-size pitch as compared to the half-size pitch. The surface area covered by the team (half-size pitch: 431.83 m2 vs full-size pitch: 589.14 m2) was significantly larger in the full-size pitch condition. However, the reduced half-size pitch significantly contributed to a greater individual spatial exploration. Results of this study suggest that running and sprinting activities increase when large, full-size pitch dimensions are utilized. Smaller surface area half-size pitch contributes to a better exploration of the pitch measured by spatial exploration index while maintaining adequate surface area coverage by the team. In conclusion, the authors suggest that the small half-size pitch is more appropriate for low-intensity training sessions and field exploration for players in different positions. Alternatively, the large full-size pitch is more appropriate for greater physically demanding training sessions with players focused on positional tactical behavior.info:eu-repo/semantics/publishedVersio

    Ectopic beats arise from micro-reentries near infarct regions in simulations of a patient-specific heart model

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    Ectopic beats are known to be involved in the initiation of a variety of cardiac arrhythmias. Although their location may vary, ectopic excitations have been found to originate from infarct areas, regions of micro-fibrosis and other heterogeneous tissues. However, the underlying mechanisms that link ectopic foci to heterogeneous tissues have yet to be fully understood. In this work, we investigate the mechanism of micro-reentry that leads to the generation of ectopic beats near infarct areas using a patient-specific heart model. The patient-specific geometrical model of the heart, including scar and peri-infarct zones, is obtained through magnetic resonance imaging (MRI). The infarct region is composed of ischemic myocytes and non-conducting cells (fibrosis, for instance). Electrophysiology is captured using an established cardiac myocyte model of the human ventricle modified to describe ischemia. The simulation results clearly reveal that ectopic beats emerge from micro-reentries that are sustained by the heterogeneous structure of the infarct regions. Because microscopic information about the heterogeneous structure of the infarct regions is not available, Monte-Carlo simulations are used to identify the probabilities of an infarct region to behave as an ectopic focus for different levels of ischemia and different percentages of non-conducting cells. From the proposed model, it is observed that ectopic beats are generated when a percentage of non-conducting cells is near a topological metric known as the percolation threshold. Although the mechanism for micro-reentries was proposed half a century ago to be a source of ectopic beats or premature ventricular contractions during myocardial infarction, the present study is the first to reproduce this mechanism in-silico using patient-specific data.Peer ReviewedPostprint (published version

    New insights about functional and cross-reactive properties of antibodies generated against recombinant TbpBs of Haemophilus parasuis

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    Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Te images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.[EN] Vaccines have become fundamental in the control and elimination of Glässer Disease, a systemic disease of pigs caused by Haemophilus parasuis. The classic vaccines available for prevention of this infection were developed without a robust knowledge about host immunological mechanisms. In this study, we demonstrated the presence of cross-reactive epitopes on both the N-lobe and C-lobe of variants of transferrin binding protein B (TbpBs) expressed on the surface of 6 virulent serovars of H. parasuis. Antibodies against TbpB-derived antigens were capable of increasing the phagocytic capacity of neutrophils and were also capable of blocking porcine transferrin from binding to TbpB. Surprisingly, none of the pig or mice antisera from animals immunized with TbpB-derived antigens mixed with Montanide IMS 2215 VG PR adjuvant were able to activate the classical complement pathway (CCP). In contrast, antisera from mice immunized with TbpB-derived antigens adjuvanted with Freund's adjuvants or Montanide Gel 01 were able to activate the CCP and kill H. parasuis. Our results demonstrate that the type of adjuvant can modulate the functional response induced by TbpB-derived antigens. Based on these results, we propose that a properly formulated TbpB-based vaccine may elicit a functional protective antibody response with broad cross-reactivity against heterologous strains of H. parasuis.SIThis work was supported by the Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq, grant 485807/2013-0) and by the Spanish Ministry of Economy and Competitivity (grant AGL2011-23195). B.B. and J.G. were supported by a Master fellowship from the Fundação Universidade de Passo Fundo and from the Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES), respectively. We would also like to thank Dra. Letícia Gressler for technical assistance in the complement system assays

    Mycobiota and Aflatoxin B1 in Feed for Farmed Sea Bass (Dicentrarchus labrax)

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    Thesafety characteristics of feed used in fish and crustacean aquaculture systems are an essential tool to assure the productivity of those animal exploitations. Safety of feed may be affected by different hazards, including biological and chemical groups. The aim of this preliminary study was to evaluate fungi contamination and the presence of aflatoxins in 87 samples of feed for sea bass, collected in Portugal. Molds were found in 35 samples (40.2%) in levels ranging from 1 to 3.3 log10 CFU∙g−1. Six genera of molds were found. Aspergillus flavus was the most frequent, found in all positive samples, with a range from 2 to 3.2 log10 CFU∙g−1. Aspergillus niger was found in 34 samples (39.1%), ranging from 1 to 2.7 log10 CFU∙g−1. Aspergillus glaucus was found in 26 samples (29.9%) with levels between 1 and 2.4 log10 CFU∙g−1. Penicillium spp. and Cladosporium spp. were both found in 25 samples (28.7%). Fusarium spp. was found in 22 samples (25.3%), ranging from 1 to 2.3 log10 CFU∙g−1. All feed samples were screened for aflatoxins using a HPLC technique, with a detection limit of 1.0 μg∙kg−1. All samples were aflatoxin negative

    The GO-DACT protocol : a multicentre, randomized, double-blind, parallel-group study to compare the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy

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    © 2001-2020 Sociedade Portuguesa de ReumatologiaThe GO-DACT is an investigator-initiated, national, multicentric randomized placebo-controlled double-blinded trial, that assesses dactylitis as primary endpoint. Psoriatic arthritis patients naïve to methotrexate and biologic disease modifying anti-rheumatic drugs, with at least one active dactylitis, were assigned to golimumab in combination with methotrexate or placebo in combination with methotrexate, for 24 weeks. Both clinical (dactylitis severity score and the Leeds dactylitis index) and imaging (high resolution magnetic resonance imaging), among others, were assessed as outcomes. The main objective of GO-DACT is to provide evidence to improve the treatment algorithm and care of psoriatic arthritis patients with active dactylitis. In this manuscript we describe the GO-DACT protocol and general concepts of the methodology of this trial.info:eu-repo/semantics/publishedVersio

    GO-DACT : a phase 3b randomised, double-blind, placebo-controlled trial of GOlimumab plus methotrexate (MTX) versus placebo plus MTX in improving DACTylitis in MTX-naive patients with psoriatic arthritis

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    © author(s) (or their employer(s)) 2020. Re-use permitted under CC BY- nC. no commercial re-use. see rights and permissions. Published by BMJ. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license.Objectives: To assess the efficacy of golimumab in combination with methotrexate (MTX) versus MTX monotherapy in psoriatic arthritis (PsA) dactylitis. Methods: Multicentre, investigator-initiated, randomised, double-blind, placebo-controlled, parallel-design phase 3b trial in 11 Portuguese rheumatology centres. Patients with PsA along with active dactylitis and naive to MTX and biologic disease-modifying antirheumatic drugs (bDMARDs) were randomly assigned to golimumab or placebo, both in combination with MTX. The primary endpoint was Dactylitis Severity Score (DSS) change from baseline to week 24. Key secondary endpoints included DSS and Leeds Dactylitis Index (LDI) response, and changes from baseline in the LDI and MRI dactylitis score. Analysis was by intention-to-treat for the primary endpoint. Results: Twenty-one patients received golimumab plus MTX and 23 MTX monotherapy for 24 weeks. One patient from each arm discontinued. Patient inclusion was halted at 50% planned recruitment due to a favourable interim analysis. Median baseline DSS was 6 in both arms. By week 24, patients treated with golimumab plus MTX exhibited significantly greater improvements in DSS relative to MTX monotherapy (median change of 5 vs 2 points, respectively; p=0.026). In the golimumab plus MTX arm, significantly higher proportions of patients achieved at least 50% or 70% improvement in DSS and 20%, 50% or 70% improvement in LDI in comparison to MTX monotherapy. Conclusions: The combination of golimumab and MTX as first-line bDMARD therapy is superior to MTX monotherapy for the treatment of PsA dactylitis.info:eu-repo/semantics/publishedVersio

    Alteração de enzimas hepáticas em trabalhadores de refinaria de petróleo

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    OBJECTIVE: Occupational exposure typical of an oil refinery may alter liver function among the workers. Thus, the objective of the study was to identify risk factors for liver enzyme abnormalities among oil refinery workers. METHODS: The workers at an oil refinery in Northeastern Brazil underwent routine annual medical examination from 1982 to 1998. This case-control study investigated all the 150 cases of individuals with simultaneous gamma-glutamyltransferase and alanine aminotransferase abnormalities of at least 10% above reference levels. As controls, 150 workers without any liver enzyme or bilirubin abnormalities since starting to work there were selected. Odds ratios and the respective 95% confidence intervals were calculated from logistic regression models. RESULTS: In all the production sectors, the risk of liver enzyme abnormalities was significantly higher than in the administrative sector (OR=5.7; 95% CI: 1.7-18.4), even when the effects of alcohol, obesity and medical history of hepatitis were controlled for. During the period from 1992 to 1994, 88 out of the 89 cases occurred among workers from the various production sectors. CONCLUSIONS: Occupational exposure plays an important role in causing liver enzyme abnormalities among oil refinery workers. This is in addition to the specifically biological and/or behavioral risk factors such as obesity and alcohol consumption.OBJETIVO: A exposição ocupacional típica de uma refinaria de petróleo pode alterar a função hepática de seus trabalhadores. Assim, o objetivo do estudo foi identificar fatores de risco de alterações em enzimas hepáticas em trabalhadores de uma refinaria de petróleo. MÉTODOS: Os trabalhadores de uma refinaria de petróleo, localizada em São Francisco do Conde, Estado da Bahia, eram submetidos a exames periódicos anuais de 1982 a1998. O estudo caso-controle investigou todos os 150 casos de indivíduos com alteração simultânea de gama-glutamil transferase e de alanino amino transferase, de pelo menos 10% acima do valor de referência. Como controles, foram selecionados 150 indivíduos sem quaisquer alterações de enzimas hepáticas ou de bilirrubinas, desde a sua admissão. Foram calculadas as razões de chance e respectivos intervalos de confiança de 95% a partir de modelos de regressão logística. RESULTADOS: Em todos os setores de produção, o risco de alteração de enzimas hepáticas foi significantemente mais elevado do que no setor administrativo (RC=5,7; IC 95%: 1,7-18,4), estando controlados os efeitos do álcool, obesidade e antecedentes médicos de hepatite. No período 1992-1994 foram registrados 89 casos, 88 deles provieram dos diversos setores da produção. CONCLUSÕES: A exposição ocupacional desempenha papel importante na determinação de alterações de enzimas hepáticas em trabalhadores do refino de petróleo, além dos fatores de risco eminentemente biológicos e/ou comportamentais como obesidade e o consumo de álcool

    Alteração de enzimas hepáticas em trabalhadores de refinaria de petróleo

    Get PDF
    OBJECTIVE: Occupational exposure typical of an oil refinery may alter liver function among the workers. Thus, the objective of the study was to identify risk factors for liver enzyme abnormalities among oil refinery workers. METHODS: The workers at an oil refinery in Northeastern Brazil underwent routine annual medical examination from 1982 to 1998. This case-control study investigated all the 150 cases of individuals with simultaneous gamma-glutamyltransferase and alanine aminotransferase abnormalities of at least 10% above reference levels. As controls, 150 workers without any liver enzyme or bilirubin abnormalities since starting to work there were selected. Odds ratios and the respective 95% confidence intervals were calculated from logistic regression models. RESULTS: In all the production sectors, the risk of liver enzyme abnormalities was significantly higher than in the administrative sector (OR=5.7; 95% CI: 1.7-18.4), even when the effects of alcohol, obesity and medical history of hepatitis were controlled for. During the period from 1992 to 1994, 88 out of the 89 cases occurred among workers from the various production sectors. CONCLUSIONS: Occupational exposure plays an important role in causing liver enzyme abnormalities among oil refinery workers. This is in addition to the specifically biological and/or behavioral risk factors such as obesity and alcohol consumption.OBJETIVO: A exposição ocupacional típica de uma refinaria de petróleo pode alterar a função hepática de seus trabalhadores. Assim, o objetivo do estudo foi identificar fatores de risco de alterações em enzimas hepáticas em trabalhadores de uma refinaria de petróleo. MÉTODOS: Os trabalhadores de uma refinaria de petróleo, localizada em São Francisco do Conde, Estado da Bahia, eram submetidos a exames periódicos anuais de 1982 a1998. O estudo caso-controle investigou todos os 150 casos de indivíduos com alteração simultânea de gama-glutamil transferase e de alanino amino transferase, de pelo menos 10% acima do valor de referência. Como controles, foram selecionados 150 indivíduos sem quaisquer alterações de enzimas hepáticas ou de bilirrubinas, desde a sua admissão. Foram calculadas as razões de chance e respectivos intervalos de confiança de 95% a partir de modelos de regressão logística. RESULTADOS: Em todos os setores de produção, o risco de alteração de enzimas hepáticas foi significantemente mais elevado do que no setor administrativo (RC=5,7; IC 95%: 1,7-18,4), estando controlados os efeitos do álcool, obesidade e antecedentes médicos de hepatite. No período 1992-1994 foram registrados 89 casos, 88 deles provieram dos diversos setores da produção. CONCLUSÕES: A exposição ocupacional desempenha papel importante na determinação de alterações de enzimas hepáticas em trabalhadores do refino de petróleo, além dos fatores de risco eminentemente biológicos e/ou comportamentais como obesidade e o consumo de álcool
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