104 research outputs found

    The volume-expanding effects of autologous liquid stored plasma following hemorrhage.

    Get PDF
    Background: Plasma use has increased since studies have suggested that early treatment with blood components in trauma with severe hemorrhage may improve outcome. Plasma is also commonly used to correct coagulation disturbances in non-bleeding patients. Little is known about the effects of plasma transfusion on plasma volume. We report a prospective interventional study in which the plasma volume-expanding effect of autologous plasma was investigated after a controlled hemorrhage. Methods: Plasma obtained by plasmapheresis from nine healthy regular blood donors was stored at 2-6°C. Five weeks after donation the subjects were bled of 600 ml and then transfused with 600 ml of autologous plasma. Plasma volume was estimated using (125)I-albumin before and after bleeding, and immediately after plasma transfusion. Plasma volume changes were then estimated by measuring changes in hematocrit during the following 3-h period. Results: Estimated plasma volume after bleeding was 3170 ± 320 ml and 3690 ± 380 ml (mean ± standard deviation) immediately following the transfusion of plasma (p 0.05). This increase in plasma volume corresponds to 86 ± 13% of the infused volume. Three hours after transfusion, plasma volume was still 3680 ± 410 ml. Conclusions: Stored liquid plasma has a plasma volume expanding effect up to 86% of its infused volume with a duration of at least 3 h

    A Wireless Future: performance art, interaction and the brain-computer interfaces

    Get PDF
    Although the use of Brain-Computer Interfaces (BCIs) in the arts originates in the 1960s, there is a limited number of known applications in the context of real-time audio-visual and mixed-media performances and accordingly the knowledge base of this area has not been developed sufficiently. Among the reasons are the difficulties and the unknown parameters involved in the design and implementation of the BCIs. However today, with the dissemination of the new wireless devices, the field is rapidly growing and changing. In this frame, we examine a selection of representative works and artists, in comparison to the current scientific evidence. We identify important performative and neuroscientific aspects, issues and challenges. A model of possible interactions between the performers and the audience is discussed and future trends regarding liveness and interconnectivity are suggested

    The mosaic oat genome gives insights into a uniquely healthy cereal crop

    Get PDF
    Cultivated oat (Avena sativa L.) is an allohexaploid (AACCDD, 2n = 6x = 42) thought to have been domesticated more than 3,000 years ago while growing as a weed in wheat, emmer and barley fields in Anatolia1,2. Oat has a low carbon footprint, substantial health benefits and the potential to replace animal-based food products. However, the lack of a fully annotated reference genome has hampered efforts to deconvolute its complex evolutionary history and functional gene dynamics. Here we present a high-quality reference genome of A. sativa and close relatives of its diploid (Avena longiglumis, AA, 2n = 14) and tetraploid (Avena insularis, CCDD, 2n = 4x = 28) progenitors. We reveal the mosaic structure of the oat genome, trace large-scale genomic reorganizations in the polyploidization history of oat and illustrate a breeding barrier associated with the genome architecture of oat. We showcase detailed analyses of gene families implicated in human health and nutrition, which adds to the evidence supporting oat safety in gluten-free diets, and we perform mapping-by-sequencing of an agronomic trait related to water-use efficiency. This resource for the Avena genus will help to leverage knowledge from other cereal genomes, improve understanding of basic oat biology and accelerate genomics-assisted breeding and reanalysis of quantitative trait studies

    Vascular effects of prostacyclin in cat skeletal muscle and in the traumatised rat brain

    No full text
    Disturbances in microvascular function may be important for tissue damage in many disease states. Prostacyclin, a substance produced by endothelial cells, is important for the maintenance of normal vascular homeostasis and is a potential drug for treatment of microvascular dysfunction, but indications and optimal dosage remains to be established. In the present thesis we evaluated the capillary filtration coefficient (CFC)-method as a tool to investigate changes in microvascular permeability in vivo. In contrast to previous studies we found that CFC is not significantly influenced by alterations in precapillary sphincter activity and concluded that changes in CFC reflect changes in fluid permeability in cat skeletal muscle. Using the CFC-method we investigated effects of prostacyclin on microvascular fluid permeability and found that prostacyclin may decrease fluid permeability through opening of ATP-dependent potassium channels. We also found that prostacyclin may be released and decrease fluid permeability following increases in plasma concentrations of endothelin-1. We also investigated effects of prostacyclin in a low dose, which is clinically applicable without side effects such as hypotension, on macromolecular permeability in cat skeletal muscle and found that such a treatment could counteract an increase in macromolecular permeability. In order to evaluate potentially beneficial effects on microvascular perfusion following a brain trauma, prostacyclin in a low dose was administered following traumatic brain injury in rats. Prostacyclin reduced cell death simultaneously with an increase in cerebral blood flow and an increase in the number of perfused capillaries in the injured part of the brain. The results presented in the present thesis suggest that treatment with prostacyclin in low doses may be beneficial in disease states characterised by an impaired microvascular perfusion and increased vascular permeability such as following a brain trauma

    Critical Aspects on Evaluation of Autoregulation After a Severe Traumatic Brain Injury

    No full text

    Effects of l-arginine on cerebral blood flow, microvascular permeability, number of perfused capillaries, and brain water content in the traumatized mouse brain.

    No full text
    It is has been suggested that decreased production of the vasodilatory and anti-aggregative substance NO (nitric oxide) may result in lower cerebral blood flow (CBF) in injured areas of the traumatized brain. The NO-precursor L-arginine has been shown to counteract CBF decreases early after trauma, but microcirculatory and more long-term effects on CBF of L-arginine have not been investigated. In an attempt to analyze effects Of L-arginine on the microcirculation in the traumatized brain, the present study was designed to evaluate the effects Of L-arginine compared to vehicle (0.9% saline) following a standardized controlled cortical-impact brain trauma in mice. Cerebral blood flow (autoradiography [C-14]-iodoantipyrine), number of perfused capillaries (FITC-dextran fluorescence technique), brain water content (wet vs. dry weight) and the blood to brain transfer constant K-i for [Cr-51]-EDTA were analyzed in the injured and the contralateral cortex. Cortical blood flow in the injured cortex was 0.43 +/- 0.3 mL/g/min and 0.8 +/- 0.3 mL/g/min 3 h after trauma in the vehicle and L-arginine groups, respectively (p < 0.05), and no treatment effect was seen 24 h after trauma. The number of perfused capillaries decreased following trauma and was unaffected by L-arginine. Ki increased following trauma and was unaffected by L-arginine. Brain water content was lower in the L-arginine group than in the vehicle group 3 h after trauma and there was no difference between the groups 24 h after trauma. We conclude that L-arginine reduces brain edema formation and improves cortical blood flow in the early phase after a brain trauma, whereas no circulatory effects can be seen after prolonged treatment

    Plasma Volume Expansion with 5% Albumin Compared to Ringer's Acetate during Normal and Increased Microvascular Permeability in the Rat.

    No full text
    It is believed that the effectiveness of colloids as plasma volume expanders is dependent on the endothelial permeability for macromolecules. The objective of this study was to test the hypothesis that the plasma volume expanding effect of 5% albumin relative to that of a crystalloid solution is reduced if microvascular permeability is increased
    • …
    corecore