2,204 research outputs found
Erythrocyte as a link between basic and clinical research
© 2011 – IOS Press and the authorsWe review the major hemorheological experimental studies that show the erythrocyte aggregation as a link between basic and clinical research. The results of the clinical cross-sectional and longitudinal studies presented here will highlight the possible association between erythrocyte aggregation and plasma fibrinogen. Basic studies conducted in vitro are also mentioned as for its relevance in answering questions raised in clinical settings, as well as and in understanding the underlying influent factors in the erythrocyte tendency to aggregate and disaggregate.This work was supported by
“Fundação para a Ciência e Tecnologia
Fish assemblages in the seagrass beds at Inhaca Island (Mozambique): cold season
Bol. Mus. Mun. Funchal, Sup. N.º 6: 111-125, 2001The fish communities in the seagrass beds at Inhaca Island (Mozambique) were sampled in three stations during the cold season (July-August 1993). On the whole, 66 species of fishes belonging to 34 families were collected by trawling. Cluster and factorial correspondence analyses showed that the fish community structure was different at the three stations. These structural differences were attributed to the type of seagrass association and to the proximity of mangrove and coral reef areas. Differences between day and night samples attest to the occurrence of marked circadian changes between nocturnal and diurnal components of this seagrass fish community. Carnivorous fishes were dominant both in number and biomass while herbivorous and omnivorous species were less represented in these assemblages.As comunidades ictiológicas dos fundos de fanerogâmicas da Ilha da Inhaca (Moçambique) foram amostradas em 3 estações durante a estação a estação fria (Julha-Agosto de 1993). No total, 66 espécies de peixes pertencendo a 34 famílias foram colhidas com arrasto. A análise dos dados mostrou que as comunidades ictiológicas tinham estruturas diferentes nas 3 estações. Estas diferenças foram atribuídas ao tipo de associação vegetal e à distância às áreas de coral e de mangal. Diferenças entre as amostragens diurnas e nocturnas atectam a ocorrência de ciclos circadianos marcados e a sua influência nas comunidades. Espécies carnívoras foram dominantes, quer em número, quer em biomassa, em relação às herbívoras e omnívoras
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
Diversity and multiculturalism: Research and design for Bafatá upon the 90th anniversary of Amilcar Cabral’s birth
This paper aims to present the results of a research made by a group of students about the city of Bafatá, in Guinea-Bissau. This work was launched due to the
commemorations of the African independence leader Amílcar Cabral’s birth (1924-1973) in that city on the Geba riverbank, ninety years ago. The research made with students finalizing their Integrated Master in Architecture of ISCTE-Lisbon University Institute had as main goal the recognition of the urban changes of Bafatá and the designing of an ephemeral structure with the purpose of preserving and showing Cabral’s life and thoughts.
Bafatá’s centre is strongly marked by the Portuguese colonial presence, visible in the urban design, and in the several layers of architecture that qualify the city. It is around the boulevard, which articulates, in the Northeast/Southwest direction, the main entrance in town with the river Geba, that the blocks layout was organized (the hospital, the school, the governor house, the church, the post-office, the neo-Arab municipal market, and a badly damaged small pool complex from the 60s, are the most remarkable buildings). The house, where supposedly Amílcar Cabral was born, is integrated in this nucleus.
Nowadays, the atmosphere of the formal city contrasts with a huge and informal periphery surrounding this nuclear settlement. The difference between these two
realities is very sharp, while the city centre of Bafatá remains sparsely populated and depressed, the big dimension of the periphery conveyed housing and the main commercial activities.
The discourse of multiculturalism and ethnical unifying enunciated by Amílcar Cabral since the early 50s - particularly meaningful in this period of politic instability
in Guinea-Bissau - was taken as a fundamental argument for territorial development of Bafatá in the designs by the groups of students.info:eu-repo/semantics/publishedVersio
“Right on the edge”: Europe’s westernmost hotel and Wim Wenders' “The State of Things”
With its lobby located at 38°49'2"N and 9°28'32"W, the Arribas Hotel at Portugal’s Praia
Grande is Europe’s most occidental purpose-built hotel facility. It was the stage for the
shooting of The State of Things, which the director Wim Wenders started 40 years ago and
premiered at the 1982 Venice Film Festival. This work, by the Düsseldorf-born director, is a
“movie-within-a-movie” which portrays a film crew that is making a sci-fi film called The
Survivors in the Sintra-Lisbon, but run out of money and film-stock, and become stranded in
the derelict hotel where they are quartered. In the film, a monologue by the character Robert
(Geoffrey Carey), set inside a motel bedroom, echoes Wenders’ attraction to the location.info:eu-repo/semantics/acceptedVersio
Neuroinflammation induces glial aromatase expression in the uninjured songbird brain
<p>Abstract</p> <p>Background</p> <p>Estrogens from peripheral sources as well as central aromatization are neuroprotective in the vertebrate brain. Under normal conditions, aromatase is only expressed in neurons, however following anoxic/ischemic or mechanical brain injury; aromatase is also found in astroglia. This increased glial aromatization and the consequent estrogen synthesis is neuroprotective and may promote neuronal survival and repair. While the effects of estradiol on neuroprotection are well studied, what induces glial aromatase expression remains unknown.</p> <p>Methods</p> <p>Adult male zebra finches (<it>Taeniopygia guttata</it>) were given a penetrating injury to the entopallium. At several timepoints later, expression of aromatase, IL-1β-like, and IL-6-like were examined using immunohisotchemistry. A second set of zebra birds were exposed to phytohemagglutinin (PHA), an inflammatory agent, directly on the dorsal surface of the telencephalon without creating a penetrating injury. Expression of aromatase, IL-1β-like, and IL-6-like were examined using both quantitative real-time polymerase chain reaction to examine mRNA expression and immunohistochemistry to determine cellular expression. Statistical significance was determined using t-test or one-way analysis of variance followed by the Tukey Kramers post hoc test.</p> <p>Results</p> <p>Following injury in the zebra finch brain, cytokine expression occurs prior to aromatase expression. This temporal pattern suggests that cytokines may induce aromatase expression in the damaged zebra finch brain. Furthermore, evoking a neuroinflammatory response characterized by an increase in cytokine expression in the uninjured brain is sufficient to induce glial aromatase expression.</p> <p>Conclusions</p> <p>These studies are among the first to examine a neuroinflammatory response in the songbird brain following mechanical brain injury and to describe a novel neuroimmune signal to initiate aromatase expression in glia.</p
Physical interpretation of the Wigner rotations and its implications for relativistic quantum information
We present a new treatment for the spin of a massive relativistic particle in
the context of quantum information based on a physical interpretation of the
Wigner rotations, obtaining different results in relation to the previous
works. We are lead to the conclusions that it is not possible to define a
reduced density matrix for the particle spin and that the Pauli-Lubanski (or
similar) spin operators are not suitable to describe measurements where spin
couples to an electromagnetic field in the measuring apparatus. These
conclusions contradict the assumptions made by most of the previous papers on
the subject. We also propose an experimental test of our formulation.Comment: 10 pages, 2 figures. Several changes were made on the text. One extra
example was include
Dithiothreitol revisited in red cells : a new head for an old hat
© 2010 – IOS Press and the authors. All rights reservedIn the present article the authors make an approach over the applications of dithiothreitol (DTT) in its different clinicallaboratory,
potential and up-to-date sources. Dithiothreitol is a chemical reagent with a wide actuation spectrum not only from
a laboratorial view but also from a therapeutic standpoint, more clinical and practical. DTT (i) is frequently used in a variety of
experiences that involve proteins or peptides, protecting sulfhydryl groups from oxidation and reducing disulfide bonds between
cysteines; (ii) is also used in the study of disulfide exchange reactions of protein disulfides; (iii) is able to keep glutathione in the
reduced state; (iv) acts as an “antidote” enabling the activity of detoxification systems; (v) participates in cellular mechanisms
such as vesiculation, cell morphology, signal transduction pathways (hormone-‘like’ role), etc.; (vi) can be used in the treatment
approach of diseases like cystinosis or medical conditions resulting from ion or metal toxicity. In erythrocytes, there’s literature
pointing that DTT may trigger changes on the normal discoid shape following metabolic depletion, and additionally modulate
the exovesiculation kinetics as demonstrated by us. The present article dissects in detail recent findings in our Unit concerning
the DTT influence on human erythrocytes
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