Evidence that the degree of band 3 phosphorylation modulates human erythrocytes nitric oxide efflux – in vitro model of hyperfibrinogenemia

© 2011 – IOS Press and the authors. All rights reservedRecent evidence has shown that plasma fibrinogen, a major cardiovascular risk factor, interacts with the erythrocyte membrane and acts to influence blood flow via erythrocyte nitric oxide (NO) modulation. In the present pioneer in-vitro study, whole blood samples were harvested from healthy subjects and aliquots were incubated in the absence (control aliquots) and presence of fibrinogen at different degrees of band 3 phosphorylation, and the levels of NO, nitrite, nitrate and S-nitroglutathione (GSNO) were determined. Hyperfibrinogenemia interferes with erythrocyte NO mobilization without changing its efflux in a way that seems to be dependent of the degree of band 3 phosphorylation. In presence of higher fibrinogen concentrations the NO efflux is reinforced when band 3 is phosphorylated (p < 0.001). Higher levels of nitrite, nitrate and GSNO were documented (p < 0.05). However, the mechanisms by which fibrinogen signalling modulates erythrocyte function remain to be clarified and are currently under study. These conditions may be considered an approach to be followed in blood storage for transfusions.This study was supported by grants from the FCT - Fundação para a Ciência e a Tecnologia (project reference PTDC/SAU-OSM/73449/2006

Hidrólise de diacetato de fluoresceína como bioindicador da qualidade de solo de várzea subtropical.

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Paratrichodorus divergens sp. n., a new potential virus vector of tobacco rattle virus and additional observations on P. hispanus Roca & Arias, 1986 from Portugal (Nematoda: Trichodoridae)

During a survey of trichodorids in Continental Portugal, a new trichodorid species, Paratrichodorus divergens sp. n., was found. It is described and illustrated with specimens from the type locality and additional morphometric data and photographs of specimens obtained from soil samples collected in seven other localities are also included. The species is characterised in female by distinct drop-like to triangular oblique vaginal sclerotisations diverging outwards, sperm cells usually distributed all through the uteri, and in male by thin, almost straight, striated spicules, the two posteriormost pre-cloacal supplements relatively close to one another and usually opposite the distal third of retracted spicules, a slightly bilobed cloacal lip and sperm cells with sausage-shaped nucleus. Paratrichodorus divergens sp. n. most closely resembles P. hispanus Roca & Arias, 1986 with which it often occurs in mixed populations. Additional information is also provided for P. hispanus. For the new species, coding of the features are added following Decraemer and Baujard’s identification key.Centro de Biologia da Universidade do Minho (CB)

Exequibilidade do DDRT-PCR para análise da expressão gênica diferencial em células de medula óssea murina

Model of study: Experimental study. Introduction: Recently, stem cell research has generated greatinterest due to its applicability in regenerative medicine. Bone marrow is considered the most importantsource of adult stem cells and the establishment of new methods towards gene expression analysisregarding stem cells has become necessary. Thus Differential Display Reverse Transcription Polymerase Chain Reaction (DDRT-PCR) may be an accessible tool to investigate small differences in the geneexpression of different stem cells in distinct situations.Aim: In the present study, we investigated the exequibility of DDRT-PCR to identify differences in globalgene expression of mice bone marrow cells under two conditions.Methods: First, bone marrow cells were isolated fresh and a part was cultivated during one week withoutmedium replacement. Afterwards, both bone marrow cells (fresh and cultivated) were submitted to geneexpression analyses by DDRT-PCR.Results: Initially, it was possible to observe in one week-cultured bone marrow cells, changes in morphology (oval cells to fibroblastic-like cells) and protein profile, which was seen through differences inband distribution in SDS-Page gels. Finally through gene expression analysis, we detected three bands(1300, 1000 and 225 bp) exclusively expressed in the fresh bone marrow group and two bands (400 and300 bp) expressed specifically in the cultivated bone marrow cell group.Conclusions: In summary, the DDRT-PCR method was proved efficient towards the identification ofsmall differences in gene expression of bone marrow cells in two defined conditions. Thus, we expectthat DDRT-PCR can be fast and efficiently designed to analyze differential gene expression in severalstem cell types under distinct conditions.Modelo do estudo: Estudo Experimental. Introdução: Atualmente a pesquisa com células-tronco temgerado grande interesse devido a sua aplicabilidade no campo na medicina regenerativa. A medulaóssea é considerada a maior fonte de células-tronco adultas e o estabelecimento de novos métodospara a análise da expressão gênica torna-se estritamente necessário. Desse modo, o "DifferentialDisplay Reverse Transcription Polymerase Chain Reaction (DDRT-PCR)", pode ser uma ferramentaacessível para a investigação de pequenas diferenças no nível de expressão gênica em diferentes tiposcelulares, sob distintas condições.Objetivo: Neste presente trabalho nós investigamos a exequibilidade do DDRT-PCR na identificação dediferenças no nível de expressão gênica global em células da medula óssea de camundongos sobduas condições. Métodos: Primeiramente, a medula óssea foi isolada frescamente e uma secundaparte foi cultivada por uma semana sem troca de meio. Posteriormente, as células da medula (fresca ecultivada) foram submetidas a análise da expressão gênica, seguindo a metodologia de DDRT-PCR.Resultados: Inicialmente, foi possível identificar em células da medula óssea com uma semana decultivo, pequenas alterações morfológicas (células ovais para fibroblastóides) e no perfil de proteínas,por meio da visualização de bandas em SDS-Page gel. Finalmente, a análise da expressão gênica porDDRT-PCR, mostrou uma expressão diferencial com a presença de três bandas (1300, 1000 and 225pb) exclusivamente expressas na medula óssea fresca e mais duas bandas (400 and 300 pb) presentes somente nas células de medula cultivadas.Conclusões: Em suma, a metodologia de DDRT-PCR mostrou-se eficiente para a identificação depequenas diferenças no nível de expressão gênica em células da medula óssea sob duas definidascondições. Portanto, nós acreditamos que o DDRT-PCR possa ser designado de forma rápida e eficiente para a análise diferencial de expressão gênica em diferentes tipos de células-tronco, sob diferentescondições

Caracterização morfobiológica, morfométrica e ultraestrutural de isolados silvestres de Trypanosoma cruzi do estado do Rio de Janeiro, Brasil

Triatoma vitticeps is a triatomine with geographic distribution restrict to Brazil, which exhibits high prevalence of Trypanosoma cruzi natural infection. Of special epidemiologic concern, this species often invades households in the states of Rio de Janeiro, Minas Gerais and Espirito Santo. The objective of this study was to evaluate morphological and ultrastructural parameters on three T. cruzi isolates obtained from wild T. vitticeps specimens. The growth and cell differentiation of the parasite was evaluated through epimastigote and trypomastigote forms obtained in the growth curves for three distinct isolates. The maximum growth showed differences at the 20th day of the curve. Our in vitro results show a heterogeneity, regarding these features for samples cultivated under the same conditions. Morphometric analyzes based on the shape of epimastigotes and trypomastigotes corroborated such differentiation. These results highlight the need of better understanding the meaning of this diversity under an eco-epidemiological perspective792294303COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJTriatoma vitticeps é um triatomíneo com distribuição geográfica restrita ao território brasileiro, apresentando alta prevalência de infecção natural pelo Trypanosoma cruzi. Esta espécie é relevante sob o ponto de vista epidemiológico por invadir domicílios com frequência nos estados do Rio de Janeiro, Minas Gerais e Espírito Santo. O objetivo deste estudo foi avaliar parâmetros morfológicos e ultraestruturais, em três isolados de T. cruzi obtidos a partir de triatomíneos silvestres. O crescimento e a diferenciação celular do parasita foi avaliado através das formas epimastigotas e tripomastigotas obtidas nas curvas de crescimento para os três isolados. O crescimento máximo mostrou diferenças no 20º dia da curva. Nossos resultados in vitro mostram uma heterogeneidade, em relação a essas características para amostras cultivadas nas mesmas condições. As análises morfométricas baseadas na conformação de epimastigotas e trypomastigotes corroboraram essa diferenciação. Estes resultados ressaltam a necessidade de uma melhor compreensão do significado desta diversidade sob uma perspectiva eco-epidemiológicaThe authors thank “Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC-FIOCRUZ), Brasi

Mammalian sphingoid bases: Biophysical, physiological and pathological properties

Sphingoid bases encompass a group of long chain amino alcohols which form the essential structure of sphingolipids. Over the last years, these amphiphilic molecules were moving more and more into the focus of biomedical research due to their role as bioactive molecules. In fact, free sphingoid bases interact with specific receptors and target molecules, and have been associated with numerous biological and physiological processes. In addition, they can modulate the biophysical properties of biological membranes. Several human diseases are related to pathological changes in the structure and metabolism of sphingoid bases. Yet, the mechanisms underlying their biological and pathophysiological actions remain elusive. Within this review, we aimed to summarize the current knowledge on the biochemical and biophysical properties of the most common sphingoid bases and to discuss their importance in health and disease

The renal and hepatic distribution of Bence Jones proteins depends on glycosylation: A scintigraphic study in rats

The aim of the present study was to evaluate renal and liver distribution of two monoclonal immunoglobulin light chains. the chains were purified individually from the urine of patients with multiple myeloma and characterized as lambda light chains with a molecular mass of 28 kDa. They were named BJg (high amount of galactose residues exposed) and BJs (sialic acid residues exposed) on the basis of carbohydrate content. A scintigraphic study was performed on male Wistar rats weighing 250 g for 60 min after iv administration of 1 mg of each protein (7.4 MBq), as the intact proteins and also after carbohydrate oxidation. Images were obtained with a Siemens gamma camera with a high-resolution collimator and processed with a MicroDelta system. Hepatic and renal distribution were established and are reported as percent of injected dose. Liver uptake of BJg was significantly higher than liver uptake of BJs (94.3 vs 81.4%) (P<0.05). This contributed to its greater removal from the intravascular compartment, and consequently lower kidney accumulation of BJg in comparison to BJs (5.7 vs 18.6%) (P<0.05). After carbohydrate oxidation, there was a decrease in hepatic accumulation of both proteins and consequently a higher renal overload. the tissue distribution of periodate-treated BJg was similar to that of native BJs: 82.7 vs 81.4% in the liver and 17.3 vs 18.6% in the kidneys. These observations indicate the important role of sugar residues of Bence Jones proteins for their recognition by specific membrane receptors, which leads to differential tissue accumulation and possible toxicity.UNIV São Paulo,FAC MED,LAB FISIOPATOL RENAL,BR-01246903 São Paulo,SP,BRAZILUNIV São Paulo,CTR MED NUCL,BR-05403010 São Paulo,SP,BRAZILUNIV São Paulo,HOSP CLIN,SERV RADISISOTOPOS,BR-05403000 São Paulo,SP,BRAZILUniversidade Federal de São Paulo,MOL BIOL LAB,BR-04024900 São Paulo,SP,BRAZILUniversidade Federal de São Paulo,MOL BIOL LAB,BR-04024900 São Paulo,SP,BRAZILWeb of Scienc