9 research outputs found

    Development of carpels and ovules in Dialypetalanthus fuscescens Kuhlm. (Rubiaceae): an enigmatic taxon

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    ABSTRACT Dialypetalanthus is a monospecific genus that occurs in the Amazon Basin of Brazil, Bolivia and Peru and occupies a controversial position among the Rubiaceae. We continue this taxonomic discussion with the overall aim of clarifying the systematic position of D. fuscescens within the Rubiaceae. To accomplish this, we analyzed the ontogeny of its gynoecium, in particular the floral meristem, as well as the development of the carpels and cauline placentation. Gynosporogenesis and the differentiation of the carpellary septa and ovules were also described. Dialypetalanthus fuscescens was classified according to evolutionary diagrams found in the literature. The following characteristics were observed in D. fuscescens: 1) permanence of the floral meristem in the central basal part of the early flower bud; 2) dual origin of carpellary septum; 3) trizonate ovular primordia with only one fertile gynospore per ovule; and 4) cellular proliferation in the chalazal region. Embryological results confirm the classification of D. fuscescens in the subfamily Ixoroideae. These results are distinct from any others previously proposed in the evolutionary diagram. Therefore, we conclude that this study has presented evidence strongly suggesting that Dialypetalanthus possesses new morphological-type of ovule we refer to as the Dialypetalanthus-type

    Distribuição da hipovitaminose A no Brasil nas últimas quatro décadas: ingestão alimentar, sinais clínicos e dados bioquímicos Distribution of hipovitaminosis A in Brazil in the last four decades: dietary intake, clinical signs and biochemical data

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    O presente estudo teve como objetivo o registro e a apresentação de trabalhos realizados no Brasil nos últimos 40 anos, relacionados com a investigação sobre a deficiência de vitamina A. Esta deficiência tem sido diagnosticada por um ou mais dos seguintes critérios: ingestão deficiente de alimentos fontes de vitamina A, exame clínico, níveis séricos de retinol abaixo dos aceitos como normais, concentração hepática de retinol, teste de adaptação ao escuro e corante de Rosa Bengala. A deficiência foi diagnosticada em grupos populacionais de vários Estados e capitais brasileiras em cidades grandes e pequenas e em zonas rurais. A maioria dos trabalhos foi desenvolvida em grupos populacionais de baixa renda. Quanto às conseqüências clínicas, relataram-se achados de sinais oculares leves, como cegueira noturna, manchas de Bitot e xerose conjuntival, encontrados principalmente na Região Nordeste. Alguns autores observaram, em menor número de casos, lesões graves, como lesões corneanas e ceratomalácia. Trabalhos da última década indicaram associação entre a hipovitaminose A e o aumento da morbidade e mortalidade, principalmente em crianças pré-escolares.<br>This work presents a review of investigations carried out in Brazil in the last 40 years, concerning the diagnosis of hypovitaminosis A. Vitamin A deficiency has been established by means of dietary intake, clinical signs, low serum and hepatic retinol concentrations, and by the rose bengal staining test and rapid dark-adaptation test. The vitamin deficiency has been found in many Brazilian, in many states capitals, in big and small cities and also in rural areas. Most of the research work has been undertaken with samples of populations of low socioeconomic level. As far as clinical signs are concerned, eye signs indicative of xerophtalmia were found mainly in the Northeastern Region. They included night blindness and conjunctival xerosis with or without Bitot's spots. More severe lesions such as irreversible changes or keratomalacia were rarely observed. Recent papers have shown the relationship between vitamin A deficiency and the increase in morbidity and mortality, mainly in pre-school children
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