428 research outputs found

    Dyslipidaemia and Undernutrition in Children from Impoverished Areas of Maceió, State of Alagoas, Brazil

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    Chronic undernutrition causes reduced growth and endocrine adaptations in order to maintain basic life processes. In the present study, the biochemical profiles of chronically undernourished children were determined in order to test the hypothesis that chronic undernutrition also causes changes in lipid profile in pre-school children. The study population comprised 80 children aged between 12 and 71 months, including 60 with moderate undernutrition [height-for-age Z (HAZ) scores ≤ −2 and > −3] and 20 with severe undernutrition (HAZ scores ≤ −3). Socioeconomic, demographic and environmental data were obtained by application of a questionnaire, and anthropometric measurements and information relating to sex, age and feeding habits were collected by a trained nutritionist. Blood samples were analysed for haemoglobin, vitamin A, insulin-like growth factor 1 (IGF-1) and serum lipids, while cortisol was assayed in the saliva. Faecal samples were submitted to parasitological investigation. Analysis of variance and χ2 methods were employed in order to select the variables that participated in the multivariate logistic regression analysis. The study population was socioeconomically homogeneous, while the lack of a treated water supply was clearly associated with the degree of malnutrition. Most children were parasitised and anaemia was significantly more prevalent among the severely undernourished. Levels of IGF-1 decreased significantly with increasing severity of undernutrition. Lipid analysis revealed that almost all of the children had dyslipidemia, while low levels of high-density lipoprotein were associated with the degree of undernutrition. It is concluded that chronic malnutrition causes endocrine changes that give rise to alterations in the metabolic profile of pre-school children

    Multilayer thin-film optical filters for reflectance-based malaria diagnostics

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    Malaria diagnosis relies on optical microscopy and/or rapid diagnostic tests based on detecting specific malaria antigens. The clinical sensitivity of these methods is highly dependent on parasite density, with low levels of detection at low parasite density, challenging the worldwide malaria elimination efforts. Therefore, there is a need for diagnostic methods with higher sensitivity, demanding innovative diagnostics devices able to detect malaria at low parasite density and at early stages of the disease. We propose an innovative optical device for malaria diagnosis, based on optical reflectance spectrophotometry, for the detection of parasites through the quantification of haemozoin. For this purpose, a set of eight thin-film optical filters, based on multilayer stacks of MgO/TiO2 and SiO2/TiO2 thin-films, with high transmittance and low full width at half maximum (FWHM) at specific wavelengths, was designed and fully characterized (both numerically and experimentally). A preliminary assessment of its potential to reconstruct the original spectra of red blood cells was performed, both in uninfected and Plasmodium falciparum-infected samples. The obtained results show that, although the experimental filters have a non-ideal performance characteristic, they allow us to distinguish, based on only 8 discrete points in the optical spectrum, between healthy and malaria infected samples, up to a detection limit of 12 parasites/μL of red blood cells. Those results enhance the potential of using such a device for malaria diagnostics, aiming for non-invasiveness.Project NORTE-01-0145-FEDER-028178 funded by NORTE 2020 Portugal Regional Operational Program under PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund and the Fundação para a Ciência e Tecnologia (FCT), IP. This work was also supported by national funds, through the Portuguese FCT, under the reference projects UIDB/04436/2020, UIDP/04436/2020, UIDB/50026/2020 and UIDP/50026/2020, and by the ICVS Scientific Microscopy Platform, member of the national infrastructure PPBIPortuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). V. Baptista thanks FCT for the SFRH/BD/145427/2019 grant. Maria Isabel Veiga thanks FCT for her contract funding provided through 2020.03113.CEECIND. Susana Catarino thanks FCT for her contract funding provided through 2020.00215.CEECIN

    Complex polymorphisms in the plasmodium falciparum Multidrug Resistance Protein 2 Gene and Its Contribution to Antimalarial Response

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    Complex Polymorphisms in the Plasmodium falciparum Multidrug Resistance Protein 2 Gene and Its Contribution to Antimalarial ResponsePlasmodium falciparum has the capacity to escape the actions of essentially all antimalarial drugs. ATP-binding cassette (ABC) transporter proteins are known to cause multidrug resistance in a large range of organisms, including the Apicomplexa parasites. P. falciparum genome analysis has revealed two genes coding for the multidrug resistance protein (MRP) type of ABC transporters: Pfmrp1, previously associated with decreased parasite drug susceptibility, and the poorly studied Pfmrp2. The role of Pfmrp2 polymorphisms in modulating sensitivity to antimalarial drugs has not been established. We herein report a comprehensive account of the Pfmrp2 genetic variability in 46 isolates from Thailand. A notably high frequency of 2.8 single nucleotide polymorphisms (SNPs)/kb was identified for this gene, including some novel SNPs. Additionally, we found that Pfmrp2 harbors a significant number of microindels, some previously not reported. We also investigated the potential association of the identified Pfmrp2 polymorphisms with altered in vitro susceptibility to several antimalarials used in artemisinin-based combination therapy and with parasite clearance time. Association analysis suggested Pfmrp2 polymorphisms modulate the parasite's in vitro response to quinoline antimalarials, including chloroquine, piperaquine, and mefloquine, and association with in vivo parasite clearance. In conclusion, our study reveals that the Pfmrp2 gene is the most diverse ABC transporter known in P. falciparum with a potential role in antimalarial drug resistance.This work was supported by project grants from the Swedish Development Cooperation Agency, Department for Research Cooperation (SWE 2007-174 and SWE-2009-165). M.I.V. and N.S.O. are recipients of post-doctoral fellowship from Fundacao para a Ciencia e Tecnologia (FCT)/Ministerio da Ciencia e Ensino Superior, Portugal, MCES (SFRH/BPD/76614/2011 and UMINHO/BPD/15/2014, respectively). The Shoklo Malaria Research Unit is part of the Mahidol Oxford University Tropical Medicine Research Unit and is supported by the Wellcome Trust of Great Britain

    Rapid diagnostic tests for molecular surveillance of Plasmodium falciparum malaria -assessment of DNA extraction methods and field applicability

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    Background: The need for new malaria surveillance tools and strategies is critical, given improved global malaria control and regional elimination efforts. High quality Plasmodium falciparum DNA can reliably be extracted from malaria rapid diagnostic tests (RDTs). Together with highly sensitive molecular assays, wide scale collection of used RDTs may serve as a modern tool for improved malaria case detection and drug resistance surveillance. However, comparative studies of DNA extraction efficiency from RDTs and the field applicability are lacking. The aim of this study was to compare and evaluate different methods of DNA extraction from RDTs and to test the field applicability for the purpose of molecular epidemiological investigations. Methods: DNA was extracted from two RDT devices (Paracheck-PfW and SD Bioline Malaria Pf/Pan (R)), seeded in vitro with 10-fold dilutions of cultured 3D7 P. falciparum parasites diluted in malaria negative whole blood. The level of P. falciparum detection was determined for each extraction method and RDT device with multiple nested-PCR and real-time PCR assays. The field applicability was tested on 855 paired RDT (Paracheck-Pf) and filter paper (Whatman (R) 3MM) blood samples (734 RDT negative and 121 RDT positive samples) collected from febrile patients in Zanzibar 2010. RDT positive samples were genotyped at four key single nucleotide polymorphisms (SNPs) in pfmdr1 and pfcrt as well as for pfmdr1 copy number, all associated with anti-malarial drug resistance. Results: The P. falciparum DNA detection limit varied with RDT device and extraction method. Chelex-100 extraction performed best for all extraction matrixes. There was no statistically significant difference in PCR detection rates in DNA extracted from RDTs and filter paper field samples. Similarly there were no significant differences in the PCR success rates and genotyping outcomes for the respective SNPs in the 121 RDT positive samples. Conclusions: The results support RDTs as a valuable source of parasite DNA and provide evidence for RDT-DNA extraction for improved malaria case detection, molecular drug resistance surveillance, and RDT quality control.ACT Consortium through Bill and Melinda Gates Foundation; Swedish International Development Agency (SIDA) [SWE 2009-193]; Swedish Civil Contingencies Agency (MSB) [2010-7991]; Swedish Medical Research Council (VR) [2009-3785]; Goljes Foundationinfo:eu-repo/semantics/publishedVersio

    Empowering Brazilian Northeast rural communities to desalinated drinking water access: Programa Água Doce.

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    Abstract: The Programa Água Doce-PAD(in English: Fresh Water Program) promoted by the Brazilian Federal Government under the coordinationof the Environmental Ministry, seeks to promote sustainable use of groundwater resources and provide potable water for human consumption in areas withcriticalwater scarcity in the Brazilian Semiarid region, through the use of the Reverse Osmosis Technique. The Program is guided by the following principles: community empowerment, environmental sustainability and technicalcapacity building. The methodology that led the Program to becomea success case was conceived in 2003, through a participatory process with the contribution of public Brazilian institutions such as: Federal University of Campina Grande-UFCG (Social Engagement Procedure); Brazilian Geologic Service-CPRM (Ground Water information), Brazilian Agriculture Research Corporation ?EMBRAPA (Methodology for the reuse of desalinated water concentrate), besides 10 Brazilian State ?s Governments and the civil society. The Program was launched in 2004.Ithas, presently,more than 460 installed Desalination Plants, which, together,can producea total of approximately 1.5 million liters (around 400,000 gallons) of potable water per day (considering a 8h/per dayproduction).It has,so far,benefited about 184,000 people in over 460 rural communities spread throughout the Brazilian semiarid region, ensuring safe water access to its residents. The program has already trained more than 1,000 people, including state technicians and operators of desalination systems. The Program contributes to improving the health and life quality of people in the semiarid regionas it takesinto account the naturaland socialpotential of each communitie, ensuring ways to address the vulnerabilities to which they are subjected becauseof climate variability. Social engagement is a mandatory aspect for the Program?s success. Local communities are stimulated to gain their independence by having, through the PAD methodology, their empowerment encouraged and demanded.The ultimate goal of the first large scaleplan is to take Desalination Systems to at least 1,300 communities throughout the Brazilian Semiaridregion. The Environmental Ministry is seeking to improve the systems with solar energy and automatized machinery,looking forward to improve local communities? independence

    Agricultura biossalina: desafios e alternativas para o uso de águas salobras e salinas no semiárido brasileiro.

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    Resumo: A publicação apresenta e descreve alguns desafios e alternativas técnicas para o uso de águas salobras e salinas - um dos recursos naturais importantes do semiárido brasileiro - por meio da dessalinização ou de práticas culturais que minimizem o efeito da salinidade acumulada nos solos da região usados na agricultura.bitstream/item/202816/1/Agricultura-Biossalina-Porto-Doc-121.pd

    Atividade alelopática de substâncias químicas isoladas do capim-marandu e suas variações em função do pH.

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    Este trabalho teve por objetivos isolar, identificar e caracterizar a atividade alelopática de substâncias químicas produzidas pela Brachiaria brizantha cv. Marandu e determinar as variações na atividade dessas substâncias em função da variação do pH da solução. A atividade alelopática foi realizada em bioensaios de germinação e desenvolvimento da radícula e do hipocótilo, utilizando as plantas daninhas malícia (Mimosa pudica) e mata-pasto (Senna obtusifolia) como receptoras. Os efeitos do pH foram analisados na faixa de 3,0 a 9,0. Os triterpenos pentacíclicos friedelina e epifriedelinol isolados da parte aérea de B. brizantha apresentaram baixa atividade inibitória na germinação de sementes e no desenvolvimento da radícula e do hipocótilo das duas plantas daninhas. As duas substâncias apresentaram comportamento diferenciado em relação à variação do pH da solução, com inibições mais marcantes em relação à planta daninha mata-pasto.Disponível também on-line

    Adesão às medidas de precaução-padrão: relato de experiência

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    Durante 1993 e 1994 foi realizada reciclagem em Precauções-Padrão para os profissionais de enfermagem do Centro de Atenção Integral à Saúde da Mulher (CAISM). Em 1995 foi avaliada, por observação direta nos setores, a adesão a estas medidas, o uso adequado, a acessibilidade e disponibilidade de luvas e caixas para descarte de materiais pérfuro-cortantes. Registraram-se 60 observações e 232 procedimentos. Em 164 (71%) destes houve adoção das medidas, não ocorrendo o mesmo em outros 68 (29%). Evidenciou-se a necessidade de enfatizar a lavagem de mãos e o não-reencape de agulhas.During 1993 and 1994, a recycling program on Standard Precautions was conducted for the nursing personnel at the Women's Health Centre (CAISM). In 1995, an evaluation was obtained through direct observation of these sectors regarding the adoption of these measures, the adequate use, access and availability of gloves and boxes for the disposal of perforating, sharp material. Sixty observations and 232 procedures were reported. One hundred sixty four procedures (71%) adopted these measures and 68 procedures (29%) did not. It was evident that the need to wash hands and not to use needles twice should be emphasized.Durante el periodo de 1993 y 1994 se realizó la actualización en medidas de precaución patrón para los profisionales de enfermeria del Centro de Atención Integral a la Salud de la Mujer (CAISM). En 1995, se realizó una evaluación a través de la observación directa en los sectores; la adhesión a estas medidas, el uso adecuado y la disposición de guantes y cajas para descarte de materiales corto-punzantes. Se registraron 60 observaciones e 232 procedimientos, 164 de ellos (71%) adoptaron el uso de las medidas y en 68 (29%) esto no ocurrió. Es evidente la necesidad de dar énfasis al lavado de las manos y colocar de nuevo la camisa (tapa) a las agujas

    Molecular determinants of the SARS-CoV-2 fusion peptide activity

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    The COVID-19 pandemic, caused by the SARS-CoV-2 virus, emerged in late 2019 and quickly spread worldwide, resulting in over 125 million infections and 2.7 million deaths as of March 2021 accordingly to the World Health Organization. Despite the great advances achieved by the scientific community in providing crucial information about this virus, we are still far from completely understanding it. SARS-CoV-2 is an enveloped virus, meaning that it is encapsulated by a lipid membrane, which needs to be fused to the host membrane to begin the infection process. Fusion between viral and host membrane is catalyzed by the spike (S) glycoprotein. The S-protein is composed of essential elements for the infection mechanism, namely the receptor-binding domain known to bind to angiotensin-converting enzyme 2 during the viral entry pathway. Another important region, known as the fusion peptide (FP), plays an essential part in the fusion mechanism, by inserting into and disturbing the host membrane. There is still not a consensus among scientists in terms of the fusion peptide location on the S-protein sequence, with two major candidate regions having been proposed. We recently used a machine learning-based tool developed by us to identify viral FPs with accuracies over 85%. With this tool a putative FP, previously suggested in the literature, has been identified, as well as other proposals including the requirement of more than one FP. To further address this question, we are performing a systematic analysis of the SARS-CoV-2 putative FPs, using Molecular Dynamics (MD) simulations, which provide a detailed perspective of how these peptides insert and interact with the membrane. In parallel, we are characterizing these systems experimentally. Additionally we are exploring therapeutic strategies targeting these regions. Given the major role of the FP in the virus infection process, this work provides relevant insights and contributes to the fight against COVID-19.info:eu-repo/semantics/publishedVersio
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