496 research outputs found
Eutrofització dels rius d'Andorra
8 páginas, 4 figures.An analysis of the phosphorus increase in the watersheds of Andorra as a result of
the increase of human population in the river banks is made. The greater concentrations in
phosphorus are found in relation to the increase of population and also in some sampling
stations in the highlands of this country. In high altitude the phosphorus concentrations
are related to hotel and sport facilities. Also the influence of water catchements to power
works are analized. In August the major stream, the Valira river, is dried in this catchement
process in station 22 and until the time of return of water (station 14) the main
river receives only wastewaters of two villages and water of minor tributaires. This means
a great increase in the phosphorus concentration in waters in stations 15 and 16 (figs. 1
and 2).
A modification in the composition of animal communities can be stated examining
the macrofauna, especially insects, of river stones. There is a relationship between phosphorus
concentration and the modification of communities. As a result of human population
increase the lower part of Andorra is higly enriched in nutrients in August, especially
in phosporus. A great quantity of phosphorus, estimated between 4 and 8 MT/month, leaves
the Valira river in the sampling station 1.Peer reviewe
Mutation of the Protein Kinase C Site in Borna Disease Virus Phosphoprotein Abrogates Viral Interference with Neuronal Signaling and Restores Normal Synaptic Activity
Understanding the pathogenesis of infection by neurotropic viruses represents a major challenge and may improve our knowledge of many human neurological diseases for which viruses are thought to play a role. Borna disease virus (BDV) represents an attractive model system to analyze the molecular mechanisms whereby a virus can persist in the central nervous system (CNS) and lead to altered brain function, in the absence of overt cytolysis or inflammation. Recently, we showed that BDV selectively impairs neuronal plasticity through interfering with protein kinase C (PKC)–dependent signaling in neurons. Here, we tested the hypothesis that BDV phosphoprotein (P) may serve as a PKC decoy substrate when expressed in neurons, resulting in an interference with PKC-dependent signaling and impaired neuronal activity. By using a recombinant BDV with mutated PKC phosphorylation site on P, we demonstrate the central role of this protein in BDV pathogenesis. We first showed that the kinetics of dissemination of this recombinant virus was strongly delayed, suggesting that phosphorylation of P by PKC is required for optimal viral spread in neurons. Moreover, neurons infected with this mutant virus exhibited a normal pattern of phosphorylation of the PKC endogenous substrates MARCKS and SNAP-25. Finally, activity-dependent modulation of synaptic activity was restored, as assessed by measuring calcium dynamics in response to depolarization and the electrical properties of neuronal networks grown on microelectrode arrays. Therefore, preventing P phosphorylation by PKC abolishes viral interference with neuronal activity in response to stimulation. Our findings illustrate a novel example of viral interference with a differentiated neuronal function, mainly through competition with the PKC signaling pathway. In addition, we provide the first evidence that a viral protein can specifically interfere with stimulus-induced synaptic plasticity in neurons
Evaluation of the performances of a single-use duodenoscope: Prospective multi-center national study
Objectives: A single-use duodenoscope (SUD) has been recently developed to overcome issues with endoscopic retrograde cholangiopancreatography (ERCP)-related cross-infections. The aim was to evaluate SUD safety and performance in a prospective multi-centre study. Methods: All consecutive patients undergoing ERCP in six French centers were prospectively enrolled. All procedures were performed with the SUD; in case of ERCP failure, operators switched to a reusable duodenoscope. Study outcomes were the successful completion of the procedure with SUD, safety and operators’ satisfaction based on a VAS 0–10 and on 22 qualitative items. The study protocol was approved by French authorities and registered (ID-RCB: 2020-A00346-33). External companies collected the database and performed statistical analysis. Results: Sixty patients (34 females, median age 65.5 years old) were enrolled. Main indications were bile duct stones (41.7%) and malignant biliary obstruction (26.7%). Most ERCP were considered ASGE grade 2 (58.3%) or 3 (35.0%). Fifty-seven (95.0%) procedures were completed using the SUD. Failures were unrelated to SUD (one duodenal stricture, one ampullary infiltration, and one tight biliary stricture) and could not be completed with reusable duodenoscopes. Median operators’ satisfaction was 9 (7–9). Qualitative assessments were considered clinically satisfactory in a median of 100% of items and comparable to a reusable duodenoscope in 97.9% of items. Three patients (5%) reported an adverse event. None was SUD-related. Conclusions: The use of a SUD allows ERCP to be performed with an optimal successful rate. Our data show that SUD could be used for several ERCP indications and levels of complexity
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