683 research outputs found
Takotsubo Cardiomyopathy: Cause of a Cardiogenic Shock
A miocardiopatia de Takotsubo, de etiologia desconhecida, caracteriza-se pela disfunção sistólica súbita e transitória dos segmentos médio-apicais do ventrÃculo esquerdo, sem doença coronária significativa, com total normalização das alterações segmentares. É mais frequente em mulheres de meia-idade, implicando diagnóstico diferencial com a sindrome coronária aguda. Apresentamos o caso de uma mulher de 59 anos que recorreu ao Serviço de Urgência por dispneia súbita e dor torácica. À admissão apresentava-se em edema pulmonar agudo hipotensivo com necessidade de suporte aminérgico e ventilação invasiva. A avaliação analÃtica demonstrava elevação dos marcadores cardÃacos. Electrocardiogramas seriados em ritmo sinusal com inversão progressiva da onda T nas derivações precordiais (v2 - v6). Ecocardiogramas de controlo revelando acinésia apical com diminuição da função sistólica global, e reversão total das alterações em duas semanas. Admitido choque cardiogénico de etiologia não esclarecida foi excluÃda doença coronária,
sustentando o diagnóstico de miocardiopatia de Takotsubo
Human red blood cells have an enhancing effect on the relative expansion of CD8+ T lymphocytes in vitro
Cell Prolif. 2001 Dec;34(6):359-67.
Human red blood cells have an enhancing effect on the relative expansion of CD8+ T lymphocytes in vitro.
Porto B, Fonseca AM, Godinho I, Arosa FA, Porto G.
Laboratory of Cytogenetics, Abel Salazar Institute for the Biomedical Sciences (ICBAS), Porto, Portugal. [email protected]
Abstract
The present study was designed to analyse the effect of red blood cells on T-cell proliferation and expansion. A comparative study was done in peripheral blood cell cultures stimulated with phytohemagglutinin, with or without red blood cells. The presence of red blood cells had a consistent enhancing effect on T lymphocyte proliferation, as determined by an increase in both the mitotic index and thymidine uptake. Phenotypic characterization of T cell blasts by flow cytometry revealed that, in the presence of red blood cells, expanding cells were preferentially CD8+ cells. Accordingly, proliferation of CD8+ lymphocytes from two patients with CD8+ hyperlymphocytosis was dependent on the presence of red blood cells. In contrast, proliferation of CD4+ lymphocytes from two patients with CD4+ hyperlymphocytosis was strongly inhibited by the presence of red blood cells. This is the first reported evidence that human red blood cells have an enhancing effect on the expansion of CD8+ lymphocytes in vitro.
PMID: 11737000 [PubMed - indexed for MEDLINE
Biodiversity associated to a floating wetland island in a freshwater pond
Floating wetland islands (FWI) are considered nature-based solutions that can be applied in different water bodies, such as lakes and rivers, in order to deliver a wide range of ecosystem services. They are recognized to promote local biodiversity, aesthetic integration and provide water quality enhancement through phytoremediation processes, although research is still needed to go deeper on the processes underlying the performance of these systems. The aim of this study was to assess de biodiversity associated to a FWI made of cork agglomerate, set up in 2018 in a freshwater pond. A polyculture comprising the plant species Iris germanica, Acorus gramineus, Caltha palustris, and Typha latifolia was considered. The culturable bacterial communities associated to the floating platform biofilm and to the plant rhizosphere were analyzed. The bacterial isolates were identified by 16S rRNA and characterized for their ability to produce plant growth promoting substances (e.g., indole-acetic acid, siderophores). The diversity of macroinvertebrates associated to FWI was also assessed. Water analysis of the pond were conducted. Preliminary data shows that there is a high bacterial diversity associated to this system and the ability to produce plant growth promoting substances has been shown. The bacterial strains with outstanding growth promoting traits can be used in the future to support phytoremediation strategies or plant resilience to climate change abiotic stresses. Regarding the biodiversity of macroinvertebrates associated with FWI they were mainly from the order Odonata. The FWI attracted mainly individuals of the genus Coenagrion (represented more than 80% of the fauna). These systems had proven to be a hotspot of biodiversity supporting water management plans and landscape and aesthetics integration. This study gives new insights into broadening the FWI applications in freshwater or polluted water.info:eu-repo/semantics/publishedVersio
Energy efficiency in olive oil mills
The paper presents some statistical data from olive oil mills in Portugal and Spain, presents the TESLA project and gives some information about energy consumption in olive oil mills
Fractional Dirac Bracket and Quantization for Constrained Systems
So far, it is not well known how to deal with dissipative systems. There are
many paths of investigation in the literature and none of them present a
systematic and general procedure to tackle the problem. On the other hand, it
is well known that the fractional formalism is a powerful alternative when
treating dissipative problems. In this paper we propose a detailed way of
attacking the issue using fractional calculus to construct an extension of the
Dirac brackets in order to carry out the quantization of nonconservative
theories through the standard canonical way. We believe that using the extended
Dirac bracket definition it will be possible to analyze more deeply gauge
theories starting with second-class systems.Comment: Revtex 4.1. 9 pages, two-column. Final version to appear in Physical
Review
Echocardiography in Emergency
A optimização do uso da ecocardiografia
encontra-se longe de ter sido alcançada. A
dificuldade ou impossibilidade de permanência fÃsica hospitalar de
cardiologista com experiência em
ecocardiografia nas 24horas, levou à abertura
e divulgação desta técnica a outras
especialidades que lidam com o doente
urgente.
O reconhecimento da importância da
ecocardiografia no diagnóstico, prognóstico e
implicação terapêutica de múltiplas
patologias, tem obrigado a uma
aprendizagem com vários nÃveis de
diferenciação, devendo ser apoiada e
integrada num grupo de referência em
ecocardiografia.
Os autores fazem uma revisão de alguns
aspectos da aplicação da ecocardiografia em
urgência. Salientam a importância da
formação contÃnua e da creditação, como
exigências fundamentais para o exercÃcio
desta técnica
Modeling of Mechanosensing Mechanisms Reveals Distinct Cell Migration Modes to Emerge From Combinations of Substrate Stiffness and Adhesion Receptor–Ligand Affinity
Mesenchymal cell migration is an integral process in development and healing. The process is regulated by both mechanical and biochemical properties. Mechanical properties of the environment are sensed through mechanosensing, which consists of molecular responses mediated by mechanical signals. We developed a computational model of a deformable 3D cell on a flat substrate using discrete element modeling. The cell is polarized in a single direction and thus moves along the long axis of the substrate. By modeling discrete focal adhesions and stress fibers, we implement two mechanosensing mechanisms: focal adhesion stabilization by force and stress fiber strengthening upon contraction stalling. Two substrate-associated properties, substrate (ligand) stiffness and adhesion receptor–ligand affinity (in the form of focal adhesion disassembly rate), were varied for different model setups in which the mechanosensing mechanisms are set as active or inactive. Cell displacement, focal adhesion number, and cellular traction were quantified and tracked in time. We found that varying substrate stiffness (a mechanical property) and adhesion receptor–ligand affinity (a biochemical property) simultaneously dictate the mode in which cells migrate; cells either move in a smooth manner reminiscent of keratocytes or in a cyclical manner reminiscent of epithelial cells. Mechanosensing mechanisms are responsible for the range of conditions in which a cell adopts a particular migration mode. Stress fiber strengthening, specifically, is responsible for cyclical migration due to build-up of enough force to elicit rupture of focal adhesions and retraction of the cellular rear. Together, both mechanisms explain bimodal dependence of cell migration on substrate stiffness observed in the literature
- …