53 research outputs found

    Direct determination of plant-growth related metabolites by capillary electrophoresis with spectrophotometric UV detection

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    The detection of plant hormones and growth regulators is of great interest for many biological studies especially in the determination of metabolites related to plan growth and differentiation. In this work, we propose a simple method based on capillary electrophoresis (CE) for the separation of different classes of plant growth regulators such as auxins, cytokinins, gibberelic acid and abscisic acid. CE with UV detection was used and the analytical conditions were as follows: phosphate buffer 25 mmol L-1, for all the measurements and the separation conditions pH 12 or 2.5, by hydrodynamic injection 5 s at 10 cm and separation voltage of 22 kV. The absorbance detection was fixed at either 220 nm or 270 nm depending on a given phytohormone class. Under these conditions, phytohormones (Indole-3-acetic acid (IAA), Gibberellic acid (GA3), Abscisic acid (ABA), picloram, zeatin and 6-Benzylaminopurine (BAP) were separated in approximately 3 to 5 min. The plant material used to verify the possibility of detection of hormone/plant growth regulators was citro (Citrus sinensis L. Osbeck) callus in the multiplication stage. In the plant tissue sample, zeatin was successfully detected. The results confirmed the potential use of CE as an efficient alternative and simple method to the classical procedures used for phytohormone detection in plant tissues.A detecção de hormônios e reguladores de crescimento em plantas é de grande interesse em uma enorme variedade de estudos biológicos. Visando este propósito nós desenvolvemos um método simples baseado em eletroforese capilar (CE) para a separação de diferentes classes de reguladores de crescimento de plantas como as auxinas, citocinina, ácidos giberélico e abscíssico. Foi utilizada CE, com detecção na região de UV; as condições de separação foram: fosfato de potássio como tampão, em concentração de 25 mmol L-1, pH 12 ou 2,5, tempo de injeção 5 s, elevando por sinfonamento o capilar, à altura de 10 cm e voltagem de separação de 22 kV. A absorbância foi fixada a 220 nm ou 270 nm, dependendo da classe do fitohormônio. Nestas condições os fitohormônios (IAA, GA3, ABA, picloram, zeatina e BAP) foram separados em um tempo de 3 a 5 min. O material oriundo de planta para verificar a possibilidade de detecção de hormônio/reguladores de crescimento de plantas foi a citro (Citrus sinensis L. Osbeck) callus no estágio de multiplicação. Na amostra de tecido de planta, a zeatina foi detectada com sucesso. Os resultados confirmaram a pontencialidade do uso de CE como um método eficiente, de baixo custo e alternativo para a detecção dessa classe de compostos em tecidos de plantas.FAPESPCNP

    Ultrasound-assisted extraction of Ca, K and Mg from in vitro citrus culture

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    An ultrasound extraction procedure for Ca, K and Mg from in vitro plant cultures is proposed, comparing cultures of different embryogenic levels of Citrus sinensis and Citrus limonia, employing ultrasound energy. Parameters related to metals extraction, such as plant material sampling, acid concentration and sonication time were investigated. For accuracy check, the proposed ultrasound extraction procedure was compared with a microwave-assisted digestion procedure and no differences in the results were verified at 95% of the confidence level. With this simple and accurate extraction procedure, it was possible to determine differences in Ca, K and Mg concentrations during Citrus embryo formation/development and between cultures (embryogenic and non-embryogenic). Finally, the ultrasound extraction method demonstrated to be an excellent alternative for handless sampling and operational costs.Apresenta-se um procedimento para extração de Ca, K e Mg de amostras de cultivo in vitro de plantas, comparando-se culturas de calo com diferentes potenciais embriogênicos de Citrus sinensis e Citrus limonia, com o emprego de energia ultra-som. Foram investigados os parâmetros relacionados com a extração de metais, tais como tipo de amostragem do material, concentração do ácido e tempo de sonicação. Visando a comprovação da exatidão, o procedimento de extração ultra-sônica foi comparado com o de digestão ácida assistida por microondas, e não foram observadas diferenças estatísticas significativas em um nível de confiança de 95%. Com este procedimento de extração simples e preciso, foi possível estabelecer diferenças nas concentrações de Ca, K e Mg durante a formação/desenvolvimento dos embriões de Citrus, bem como entre as culturas (embriogênicas e não-embriogênicas). Finalmente, a extração ultra-sônica demonstrou-se uma excelente alternativa para menor manipulação das amostras e redução de custos operacionais.470474Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Brazilian network for HIV Drug Resistance Surveillance (HIV-BresNet): a survey of treatment-naive individuals

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    Introduction: In Brazil, more than 487,450 individuals are currently undergoing antiretroviral treatment. In order to monitor the transmission of drug-resistant strains and HIV subtype distribution in the country, this work aimed to estimate its prevalence and to characterize the nationwide pretreatment drug resistance in individuals recently diagnosed with HIV between 2013 and 2015. Methods: The HIV threshold survey methodology (HIV-THS, WHO) targeting antiretroviral-naive individuals with recent HIV diagnosis was utilized, and subjects were selected from 51 highly populated cities in all five Brazilian macroregions. The HIV pol genotypic test was performed by genomic sequencing. Results: We analysed samples from 1568 antiretroviral-naive individuals recently diagnosed with HIV, and the overall transmitted drug resistance (TDR) prevalence was 9.5% (150 sequences). The regional prevalence of resistance according to Brazilian geographical regions was 9.4% in the northeast, 11.2% in the southeast, 6.8% in the central region, 10.2% in the north and 8.8% in the south. The inhibitor-specific TDR prevalence was 3.6% for nucleoside reverse transcriptase inhibitors (NRTIs), 5.8% for non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 1.6% for protease inhibitors (PIs)1.0% of individuals presented resistance to more than one class of inhibitors. Overall, subtype B was more prevalent in every region except for the southern, where subtype C prevails. Conclusions: To the best of our knowledge, this is the first TDR study conducted in Brazil with nationwide representative sampling. The TDR prevalence revealed a moderate rate in the five Brazilian geographical regions, although some cities presented higher TDR prevalence rates, reaching 14% in Sao Paulo, for example. These results further illustrate the importance of surveillance studies for designing future strategies in primary antiretroviral therapy, aiming to mitigate TDR, as well as for predicting future trends in other regions of the globe where mass antiretroviral (ARV) treatment was implemented.Brazilian Ministry of HealthUniv Fed Rio de Janeiro, Lab Virol Mol, Dept Genet IB, Rio De Janeiro, RJ, BrazilFdn Med Trop Amazonas, Manaus, Amazonas, BrazilLAPI Univ Fed Bahia, Hosp Univ Prof Edgar Santos, Lab Pesquisa, Salvador, BA, BrazilLab Cent Saude Publ Ceara Lacen CE, Fortaleza, Ceara, BrazilLab Cent Saude Publ Dist Fed, Setor Grandes Areas Norte SGAN 601, Brasilia, DF, BrazilUniv Fed Minas Gerais UFMG, Fac Med, Lab Imunol & Biol Mol DIP, Belo Horizonte, MG, BrazilLab Cent Saude Publ Mato Grosso Sul, Campo Grande, MS, BrazilLab Cent Saude Publ Pernambuco, Recife, PE, BrazilLab Municipal Curitiba, Curitiba, PR, BrazilFiocruz MS, Lab AIDS & Imunol Mol, Dept Imunol, Rio De Janeiro, RJ, BrazilUniv Fed Rio de Janeiro, Hosp Univ Clementino Fraga Filho, Lab Carga Viral, Rio de Janeiro, RJ, BrazilInst Biol Exercito, Rio De Janeiro, RJ, BrazilLab Cent Saude Publ Rio Grande Sul, Porto Alegre, RS, BrazilLab Hosp Nossa Senhora Conceicao, Porto Alegre, RS, BrazilLab Cent Saude Publ Santa Catarina, Florianopolis, SC, BrazilUNESP, Lab Biol Mol Hemocentro Botucatu, Fac Med, Botucatu, SP, BrazilUniv Estadual Campinas, Lab Pesquisa AIDS, Hosp Clin, Campinas, SP, BrazilInst Adolfo Lutz Sao Jose do Rio Preto, Lab Biol Mol, Sao Jose Do Rio Preto, SP, BrazilUniv Fed Sao Paulo UNIFESP, Escola Paulista Med, Lab Retrovirol, Sao Paulo, SP, BrazilInst Adolfo Lutz Cent, Lab Retrovirus, Ctr Virol, Nucleo Doencas Sanguineas & Sexuais, Sao Paulo, SP, BrazilMinist Saude, Dept Vigilancia Prevencao & Controle DST AIDS & H, Setor Adm Fed Sul SAFS 02, Secretaria Vigilancia Saude, Brasilia, DF, BrazilUniv Brasilia, Programa Pos Grad Saude Colet, Fac Med, Fac Ciencias Saude, Brasilia, DF, BrazilUniv Sao Paulo, Fac Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Escola Paulista Med, Lab Retrovirol, Sao Paulo, SP, BrazilBMH: TC 298/12Web of Scienc

    Molecular epidemiological investigation of Mayaro virus in febrile patients from Goiania City, 2017-2018.

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    Mayaro virus (MAYV) has historically been associated with sylvatic transmission; however, urban outbreaks have been reported in Brazil, including cases of co-detection with dengue virus (DENV). Therefore, we performed a molecular survey to investigate MAYV circulation and cocirculation with DENV within Goiania, a major city in Central-West Brazil. Among 375 subjects with arbovirus-like symptoms, 259 were positive for DENV and 26 for MAYV. Of these, 17 were coinfected with DENV-2, suggesting co-transmission of the viruses. The most common complaints at the time of inclusion were myalgia, headache, fever, arthralgia, retro-orbital pain, and skin rash. No specific symptoms were associated with MAYV when either detected alone or co-detected with DENV, compared to that when DENV was detected alone. Most MAYV-infected subjects were women with no recent travel history to rural/sylvatic areas. Phylogenetic reconstruction indicated that the MAYV identified in this study is closely related with a lineage observed in Peru, belonging to genotype D. Our results corroborate the growing circulation of MAYV in urban environments in Brazil and reinforce the need to implement laboratory diagnosis in the Unified Health System, considering that the clinical manifestations of Mayaro fever are similar to those of other arboviruses, particularly dengue. Furthermore, most cases occurred in association with DENV-2. Further phylogenetic studies are needed to evaluate MAYV, which has not been widely examined

    Positive Selection Results in Frequent Reversible Amino Acid Replacements in the G Protein Gene of Human Respiratory Syncytial Virus

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    Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a “flip-flop” phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites

    Brazilian mosquito (Diptera: Culicidae) fauna: I. Anopheles species from Porto Velho, Rondônia state, western Amazon, Brazil

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    This study contributes to knowledge of Anopheles species, including vectors of Plasmodium from the western Brazilian Amazon in Porto Velho, Rondônia State. The sampling area has undergone substantial environmental changes as a consequence of agricultural and hydroelectric projects, which have caused intensive deforestation and favored habitats for some mosquito species. The purpose of this study was to diagnose the occurrence of anopheline species from collections in three locations along an electric-power transmission line. Each locality was sampled three times from 2010 to 2011. The principal adult mosquitoes captured in Shannon trap were Anopheles darlingi, An. triannulatus, An. nuneztovari l.s., An.gilesi and An. costai. In addition, larvae were collected in ground breeding sites for Anopheles braziliensis, An. triannulatus, An. darlingi, An. deaneorum, An. marajoara, An. peryassui, An. nuneztovari l.s. and An. oswaldoi-konderi. Anopheles darlingi was the most common mosquito in the region. We discuss Culicidae systematics, fauna distribution, and aspects of malaria in altered habitats of the western Amazon
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