Time filter

Source Type

Ferreira S.A.,IBB Institute for Biotechnology And Bioengineering | Correia A.,University of Porto | Correia A.,University of Minho | Madureira P.,University of Porto | And 4 more authors.
Macromolecular Bioscience | Year: 2012

The mechanisms associated with the cellular internalization of nanomedicines must be carefully considered when designing drug- and vaccine-delivery systems. The cellular fate and effects of nanomedicines depend to a large extent on the cell uptake routes. A self-assembled mannan nanogel is developed as a vaccination platform for antigen and adjuvant delivery. The mannan nanogel uptake by murine bone-marrow-derived macrophages is found to be time-, concentration-, and energy-dependent, involving mannose-receptor-mediated phagocytosis and clathrin-mediated endocytosis. The nanogel is also visualized in the cytosol suggesting endolysosomal escape. These results indicate that mannan nanogel is a promising versatile carrier for intracellular delivery of vaccines or therapeutic agents. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Gaspar P.,Institute of Molecular and Cell Biology IBMC | Gaspar P.,Abel Salazar Biomedical Sciences Institute | Gaspar P.,University of Porto | Kallemeijn W.W.,University of Porto | And 9 more authors.
Journal of Lipid Research | Year: 2014

Lysosomal integral membrane protein-2 (LIMP2) mediates traffi cking of glucocerebrosidase (GBA) to lysosomes. Defi ciency of LIMP2 causes action myoclonus-renal failure syndrome (AMRF). LIMP2-defi cient fi broblasts virtually lack GBA like the cells of patients with Gaucher disease (GD), a lysosomal storage disorder caused by mutations in the GBA gene. While GD is characterized by the presence of glucosylceramide-laden macrophages, AMRF patients do not show these. We studied the fate of GBA in relation to LIMP2 defi ciency by employing recently designed activity-based probes labeling active GBA molecules. We demonstrate that GBA is almost absent in lysosomes of AMRF fi broblasts. However, white blood cells contain considerable amounts of residual enzyme. Consequently, AMRF patients do not acquire lipid-laden macrophages and do not show increased plasma levels of macrophage markers, such as chitotriosidase, in contrast to GD patients. We next investigated the consequences of LIMP2 deficiency with respect to plasma glycosphingolipid levels. Plasma glucosylceramide concentration was normal in the AMRF patients investigated as well as in LIMP2-defi cient mice. However, a marked increase in the sphingoid base, glucosylsphingosine, was observed in AMRF patients and LIMP2-defi cient mice. Our results suggest that combined measurements of chitotriosidase and glucosylsphingosine can be used for convenient differential laboratory diagnosis of GD and AMRF. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc. Source

Bras S.,Institute of Electronics and Informatics Engineering of Aveiro | Georgakis A.,Esthesys Ltd | Ribeiro L.,Hospital Veterinario do Porto HVP | Ferreira D.A.,University of Lisbon | And 4 more authors.
Research in Veterinary Science | Year: 2014

Hypnotic drug administration causes alterations in the electroencephalogram (EEG) in a dose-dependent manner. These changes cannot be identified easily in the raw EEG, therefore EEG based indices were adopted for assessing depth of anaesthesia (DoA). This study examines several indices for estimating dogs' DoA. Data (EEG, clinical end-points) were collected from 8 dogs anaesthetized with propofol.EEG was initially collected without propofol. Then, 100 ml h-1 (1000 mg h-1) of propofol 1% infusion rate was administered until a deep anaesthetic stage was reached. The infusion rate was temporarily increased to 200 ml h-1 (2000 mg h-1) to achieve 80% of burst suppression.The index performance was accessed by correlation coefficient with the propofol concentrations, and prediction probability with the anaesthetic clinical end-points. The temporal entropy and the averaged instantaneous frequency were the best indices because they exhibit: (a) strong correlations with propofol concentrations, (b) high probabilities of predicting anaesthesia clinical end-points. © 2014 Elsevier Ltd. Source

Ribeiro P.O.,University of Coimbra | Antunes L.M.,Royal University | Antunes L.M.,Institute of Molecular and Cell Biology IBMC | Nunes C.S.,University of Porto | And 4 more authors.
Anesthesia and Analgesia | Year: 2015

BACKGROUND: α2-Adrenoceptor agonists are used frequently in human and veterinary anesthesia as sedative/analgesic drugs. However, they can impair cognition. Little is known about the concentration-dependent effects of α2-adrenoceptor agonists on synaptic plasticity, the neurophysiological basis of learning and memory. Therefore, we investigated the effects of different concentrations of medetomidine, an α2-adrenoceptor agonist, on basal excitatory synaptic transmission and on 2 forms of synaptic plasticity: paired-pulse facilitation (PPF) and long-term potentiation (LTP). METHODS: Evoked field excitatory postsynaptic potentials were recorded in Schaffer fibers-CA1 pyramidal cell synapses of mouse hippocampal slices, and the initial field excitatory postsynaptic potentials slope was measured. For basal synaptic transmission and PPF, increasing concentrations of medetomidine (1-200 μM) were applied to each slice. For LTP experiments, individual slices were used for each tested concentration of medetomidine (0.1-0.4 μM), where LTP induction and LTP maintenance were measured. RESULTS: The lower tested concentrations of medetomidine decreased LTP in a concentration-dependent manner, whereas greater concentrations were required to decrease fiber volley amplitude and basal excitatory synaptic transmission. PPF was only affected by the greatest concentration (200 μM). CONCLUSIONS: Medetomidine decreased LTP in the mouse hippocampus, in accordance with the ability of medetomidine to induce memory deficits. © 2015 International Anesthesia Research Society. Source

Discover hidden collaborations