Differential Adhesive Properties of Sequestered Asexual and Sexual Stages of Plasmodium falciparum on Human Endothelial Cells Are Tissue Independent

The protozoan parasite Plasmodium falciparum, responsible for the most severe form of malaria, is able to sequester from peripheral circulation during infection. The asexual stage parasites sequester by binding to endothelial cell receptors in the microvasculature of various organs. P. falciparum gametocytes, the developmental stages responsible for parasite transmission from humans to Anopheles mosquitoes, also spend the almost ten days necessary for their maturation sequestered away from the peripheral circulation before they are released in blood mainstream. In contrast to those of asexual parasites, the mechanisms and cellular interactions responsible for immature gametocyte sequestration are largely unexplored, and controversial evidence has been produced so far on this matter. Here we present a systematic comparison of cell binding properties of asexual stages and immature and mature gametocytes from the reference P. falciparum clone 3D7 and from a patient parasite isolate on a panel of human endothelial cells from different tissues. This analysis includes assays on human bone marrow derived endothelial cell lines (HBMEC), as this tissue has been proposed as a major site of gametocyte maturation. Our results clearly demonstrate that cell adhesion of asexual stage parasites is consistently more efficient than that, virtually undetectable of immature gametocytes, irrespectively of the endothelial cell lines used and of parasite genotypes. Importantly, immature gametocytes of both lines tested here do not show a higher binding efficiency compared to asexual stages on bone marrow derived endothelial cells, unlike previously reported in the only study on this issue. This indicates that gametocyte-host interactions in this tissue are unlikely to be mediated by the same adhesion processes to specific endothelial receptors as seen with asexual forms

Variations in log quality of eighteen years old Toona ciliata M. Roem.

The family Meliaceae contains the most valuable timber species found in tropical regions. However, plantation of such species in their natural range is limited by damages from shoot borers of the genus Hypsipyla. Nevertheless, specifically in Brazil, the commercial cultivation of Australian cedar (Toona ciliata) has been successful for presenting a satisfactory vegetative growth, adapting to the Brazilian soil and climate, but especially for being resistant to the cedar shoot borer attacks. In spite of these favorable conditions, the majority of existing T.ciliata commercial plantations is still recent and little is known about the log quality destined for timber industries. In this sense, the present work aims at qualifying logs of 18 years old trees, with dimensions fit for sawing and grown on plantations for timber industries. From the data gathered it will be possible to assess the variability between trees in order to define forest management strategies and of breed improvements for the species. It was used eighteen years old trees from the city of Marechal Floriano – Espírito Santo state. The logs were previously measured and their defects were evaluated afterwards and from which, the trees were classified. The classification showed that the most significant defects were knots and bumps and the least pronounced defect was the log taper. The trees showed significant variations regarding the defects, suggesting the need for breeding programs in association with improved forest management practices

Apresentação das cardiopatias congênitas diagnosticadas ao nascimento: análise de 29.770 recém-nascidos

OBJETIVO: Estimar a prevalência e estudar apresentações clínicas e fatores associados às cardiopatias congênitas, diagnosticadas ao nascimento, entre agosto de 1990 e dezembro de 2003, na Maternidade do Hospital das Clínicas da Universidade Federal de Minas Gerais. MÉTODOS: Estudo retrospectivo, baseado no banco de dados, vinculado ao Estudo Colaborativo Latino-Americano de Malformações Congênitas. Foram identificados os recém-nascidos vivos (RNV) e natimortos (NM) com cardiopatias congênitas, diagnosticadas pelo ecocardiograma pós-natal ou necropsia. Entre os RNV, foram estudadas associações com peso ao nascer, gênero, idade e paridade materna. Para análise estatística, utilizou-se o teste do qui-quadrado de Pearson e regressão logística multinomial. RESULTADOS: No período, ocorreram 29.770 nascimentos (28.915 RNV e 855 NM). Entre os RNV, a prevalência das cardiopatias foi de 9,58:1.000 (277/28.915) e, entre NM, de 87,72:1.000 (75/855). A cardiopatia isolada ocorreu em 37,2% dos casos entre RNV e 18,7% entre NM; associada a anomalias de outros órgãos e sistemas sem diagnóstico sindrômico em 31,4% entre RNV e 48,0% entre NM; era componente de síndromes em 23,1% dos RNV e 32,0% dos NM. A análise multivariada mostrou associação entre cardiopatia e peso ao nascer £ 2.500 g em todas as formas de apresentações clínicas, entre idade materna ³ 35 anos nas cardiopatias componentes de síndromes e entre o gênero feminino nas cardiopatias isoladas. CONCLUSÕES: A prevalência encontrada foi alta, alertando para a importância médica das cardiopatias. Houve associação com peso ao nascer £ 2.500 g em todas as apresentações, com idade materna elevada nas cardiopatias sindrômicas e com o gênero feminino nas isoladas