DSpace Coleção: Artigos Técnico-científicos na área de Biologia Geral
https://locus.ufv.br//handle/123456789/11845
Artigos Técnico-científicos na área de Biologia Geral2024-03-29T06:11:54ZAntioxidant system response induced by aluminum in two rice cultivars
https://locus.ufv.br//handle/123456789/27413
Título: Antioxidant system response induced by aluminum in two rice cultivars
Autor(es): Ribeiro, Cleberson; Cambraia, José; Fonseca Júnior, Élcio Meira da; Peixoto, Paulo Henrique Pereira
Abstract: The antioxidant defense system response was evaluated in two rice cultivars (Oryza sativa L.), Fernandes (CNA-1158) and Maravilha (CNA-6843-1), treated with toxic levels of aluminum. After exposure to aluminum we determined plant growth, H2O2 and O2•- contents, lipid peroxidation, antioxidant enzymes activities and ascorbate and dehydroascorbate contents. Al predominantly accumulated in roots of both cultivars but it reduced root and shoot growth only in the Maravilha cultivar. Treatment with aluminum resulted in a reduction of 84 and 60% in the levels of H2O2 in the roots of the cultivars Maravilha and Fernandes, respectively, and of 26% in the levels of O2•- only in the roots of Fernandes cultivar. Increased lipid peroxidation was observed only in the roots of the Maravilha cultivar. In general, the antioxidant enzyme activities were higher in roots and increased in the presence of aluminum, especially in the Fernandes cultivar. The levels of ascorbate were higher in leaves and increased with aluminum treatment, while dehydroascorbate decreased in roots of both cultivars after aluminum treatment. However, the ascorbate/dehydroascorbate ratio increased in the roots of both cultivars after treatment with aluminum. Ascorbate, dehydroascorbate and ascorbate/dehydroascorbate levels found here point to an efficient regeneration of ascorbate, essential for the homeostasis of cellular metabolites involved in reactive oxygen species removal by rice plants treated with aluminum. Therefore, the higher tolerance of Fernandes to aluminum relative to Maravilha cultivar may be the result of better growth of the root system and shoots, higher antioxidant enzyme activities and a best use/regeneration of ascorbate.
Tipo: Artigo2012-04-01T00:00:00ZPrevalência de conjuntivite adenoviral em clínica oftalmológica no município de Viçosa (MG)
https://locus.ufv.br//handle/123456789/27242
Título: Prevalência de conjuntivite adenoviral em clínica oftalmológica no município de Viçosa (MG)
Autor(es): Rosado-Filho, Euldes Nei; Cardoso, Silvia Almeida; Marçal, Lorena Nacif; Santos, Eliziária Cardoso dos; Silva, Eduardo de Almeida Marques da; Paula, Sérgio Oliveira de; Oliveira, Leandro Licursi de
Abstract: Avaliar a prevalência de Adenovírus como agente etiológico da conjuntivite, em clínica médica oftalmológica especializada, em Viçosa, Minas Gerais, Brasil. Amostras da secreção conjuntival de 91 pacientes clinicamente diagnosticados com conjuntivite foram submetidos à reação em cadeia da polimerase (PCR), utilizando primers degenerados para a região codificadora do gene da proteína estrutural II. Posteriormente as amostras positivas foram submetidas a sequenciamento e genotipagem. A análise dos resultados de PCR revelou prevalência de 36,3% de Adenovírus. Não havendo distinção entre os sexos e com maior prevalência na faixa etária de 26 a 65 anos com 60,60% dos casos positivos. O sequenciamento dos casos positivos por Adenovírus revelaram a presença dos sorotipos 3, 4, 7, 8 e 34 circulante na região. No município de Viçosa, dois em cada cinco casos de conjuntivite são de etiologia adenoviral.; To evaluate the prevalence of Adenovírus as a etiologic agent of conjunctivitis on a ophthalmic clinic in Viçosa, Minas Gerais, Brazil. Samples of conjunctival secretion from 91 patients clinically diagnosed with conjunctivitis were subjected to polymerase chain reaction (PCR) using degenerate primers targeted to the gene encoding the structural protein II. Positive samples were subsequently subjected to sequencing and genotyping. PCR results showed 36.3% prevalence of Adenovírus. No differences between the sexes
and was found to be higher in the age group 26-65 years with 60.60% of the positive cases. Sequencing of positive cases showed the presence of Adenovírus serotypes 3, 4, 7, 8, and 34 circulating in the region. In Viçosa two in five cases of conjunctivitis has Adenovírus as etiologic agent.
Tipo: Artigo2015-07-01T00:00:00ZNova subspécie de Caprimulgus (Linnaeus) (Aves, Caprimulgidae) do Espírito Santo, Brasil
https://locus.ufv.br//handle/123456789/27223
Título: Nova subspécie de Caprimulgus (Linnaeus) (Aves, Caprimulgidae) do Espírito Santo, Brasil
Autor(es): Ribon, Rômulo
Abstract: A population of a small and dark nightjar was discovered at Colatina, Espírito Santo, and has been identified by its voice and pattern of coloration as a new subspecies of the Pygmy Nightjar Caprimulgus hirundinaceus (Spix, 1825). This represents a considerable range expansion for this poorly known species, formerly considered endemic to the xeric "caatinga" region of Northeastern Brazil. However, other populations may exist. Colatina's birds live on exposed dark rocks with which their plumage harmonizes.
Tipo: Artigo1995-01-01T00:00:00ZSoybean seed galactinol synthase activity as determined by a novel colorimetric assay
https://locus.ufv.br//handle/123456789/27219
Título: Soybean seed galactinol synthase activity as determined by a novel colorimetric assay
Autor(es): Ribeiro, Marluci; Felix, Carlos R.; Lozzi, Silene de Paulino
Abstract: Galactinol synthase (GS) is a key enzyme for the biosynthesis of raffinose oligosaccharides (RO) which are the flatulence factors present in soybean seeds and several other legumes. Understanding of soybean seed GS properties is, therefore, of biotechnological interest. The GS enzyme catalyses formation of galactinol and UDP from UDP-gal and myo-inositol. This enzyme is currently assayed by an isotopic method. We have then idealized a more convenient method for GS assay based on the indirect colorimetric determination of the UDP formed which is then hydrolyzed by exogenous apyrase and the resulting Pi quantified by a modification of the colorimetric method of Fiske & SubbaRow. The color developed is stable, and the method is suitable for detection of very low GS activity. The GS activity profiles of developing soybean seeds determined by the isotopic and the colorimetric methods are closely related. The GS enzyme was partially purified (46-fold) by treatment of seed extract with MnCl2, sequential chromatographies on DEAE-Sepharose, Phenyl-Sepharose CL-4B and Q-Sepharose columns. The crude and the partially purified enzyme showed maximum activity at pH 7.0 and 50 ºC. Dithiothreitol and MnCl2 enhanced considerably the activity of the partially purified enzyme. While UDP-glc could be hydrolyzed by the enzyme at a reative activity corresponding to 49% of that calculated for UDP-gal, UDP-man and sucrose were completely ineffective as alternative substrates.; Galactinol sintase (GS) é a enzima-chave para a biossíntese de oligosacarídeos de rafinose (RO), que são os fatores antinutricionais causadores de flatulência, os quais estão presentes em sementes de soja e em outros legumes. A GS catalisa a formação de galactinol e UDP a partir de UDP-gal e mioinositol. A atividade dessa enzima é determinada atualmente pelo método radioisotópico que, apesar de adequado tecnicamente, apresenta vários inconvenientes, tais como a necessidade de substrato de alto custo, bem como de cuidados adicionais e serviços especializados para descarte dos resíduos radioativos. Assim, desenvolveu-se um método colorimétrico alternativo ao método radioisotópico, baseado na determinação colorimétrica indireta do UDP formado pela hidrólise enzimática (apirase) desse nucleotídeo e determinação do Pi resultante pelo método de Fiske & SubbaRow, com modificações. A cor desenvolvida é estável e o método é sensível para detecção de quantidades nanomolares de Pi. Os perfis de atividade da GS em sementes de soja em diferentes fases de desenvolvimento, determinados pelos métodos colorimétrico e radioisotópico, são semelhantes. Adicionalmente, a GS de sementes de soja foi purificada (46-vezes) por tratamento do extrato das sementes com MnCl2, e uma seqüência de cromatografias em colunas de DEAE-Sepharose, Phenyl-Sepharose CL-4B e Q-Sepharose. As atividades de GS no extrato bruto e na amostra parcialmente purificada foram máximas em pH 7.0 e 50 ºC. Ditiotreitol e MnCl2 aumentaram consideravelmente a atividade da enzima parcialmente purificada. Enquanto UDP-glc pode ser hidrolisado pela enzima com uma atividade relativa correspondendo a 49% da atividade contra UDP-gal, UDP-man e sacarose foram completamente ineficazes como substratos alternativos. Os valores de KM para conversão de UDP-gal e mio-inositol foram de 2,0 mM e 2,93 mM, respectivamente, determinados pelo método de Lineaweaver-Burk.
Tipo: Artigo2000-01-01T00:00:00Z