47 research outputs found

    Desplazamiento activo escolar

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    En el siguiente proyecto se expone una investigación sobre el desplazamiento activo, entendiendo este como el traslado andando o en bicicleta a lugares cotidianos, enfocado a ponerlo en práctica en el camino a la escuela. Se analizan las ventajas e inconvenientes del desplazamiento activo, así como se profundiza en el proyecto llamado “Caminos escolares seguros” desarrollado en la ciudad de Valladolid (España).Grado en Educación Primari

    Development and Validation of a SYBR Green Real Time PCR Protocol for Detection and Quantification of Nervous Necrosis Virus (NNV) Using Different Standards

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    The nervous necrosis virus (NNV) is a threat to fish aquaculture worldwide, especially in Mediterranean countries. Fast and accurate diagnosis is essential to control it, and viral quantification is required to predict the level of risk of new viral detections in field samples. For both, reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) is used by diagnostic laboratories. In the present study, we developed an RT-qPCR procedure for the diagnosis and simultaneous quantification of NNV isolates from any of the four genotypes. The method proved to be highly sensitive in terms of crude virus titer: 5.56–9.88 TCID50/mL (tissue culture infectious dose per mL), depending on the viral strain, and averaging 8.8 TCID50/mL or 0.08 TCID50/reaction. Other standards also yielded very low detection limits: 16.3 genome copies (cps) of purified virus per mL, 2.36 plasmid cps/mL, 7.86 in vitro synthetized RNA cps/mL, and 3.16 TCID50/mL of virus from infected tissues. The diagnostic parameters evaluated in fish samples were much higher in comparison to cell culture isolation and nested PCR. In addition, the high repeatability and reproducibility of the procedure, as well as the high coefficient of determination (R2) of all the calibration curves with any type of standard tested, ensure the high reliability of the quantification of NNV using this RT-qPCR procedure, regardless of the viral type detected and from the type of standard chosenThis research was partially funded by the Interreg VA Spain-Portugal cooperation program (POCTEP) 2014-2020, 0474_BLUEBIOLAB project, co-funded by FEDERS

    Amino acidic substitutions in the polymerase N-terminal region of a reassortant betanodavirus strain causing poor adaptation to temperature increase

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    Nervous necrosis virus (NNV), Genus Betanodavirus, is the causative agent of viral encephalopathy and retinopathy (VER), a neuropathological disease that causes fish mortalities worldwide. The NNV genome is composed of two single-stranded RNA molecules, RNA1 and RNA2, encoding the RNA polymerase and the coat protein, respectively. Betanodaviruses are classified into four genotypes: red-spotted grouper nervous necrosis virus (RGNNV), striped jack nervous necrosis virus (SJNNV), barfin flounder nervous necrosis virus (BFNNV) and tiger puffer nervous necrosis virus (TPNNV). In Southern Europe the presence of RGNNV, SJNNV and their natural reassortants (in both RNA1/RNA2 forms: RGNNV/SJNNV and SJNNV/RGNNV) has been reported. Pathology caused by these genotypes is closely linked to water temperature and the RNA1 segment encoding amino acids 1–445 has been postulated to regulate viral adaptation to temperature. Reassortants isolated from sole (RGNNV/SJNNV) show 6 substitutions in this region when compared with the RGNNV genotype (positions 41, 48, 218, 223, 238 and 289). We have demonstrated that change of these positions to those present in the RGNNV genotype cause low and delayed replication in vitro when compared with that of the wild type strain at 25 and 30 °C. The experimental infections confirmed the impact of the mutations on viral replication because at 25 °C the viral load and the mortality were significantly lower in fish infected with the mutant than in those challenged with the non-mutated virus. It was not possible to challenge fish at 30 °C because of the scarce tolerance of sole to this temperature.This work was supported by Grant AGL2014-54532-C2-2-R from the Ministerio the Innovación y Competitividad (Spain), cofunded by FEDER, and by Grant ED431C 2018/18 from Xunta de Galicia (Spain)S

    Betanodavirus infection in primary neuron cultures from sole

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    Nervous necrosis virus (NNV), G. Betanodavirus, is the causative agent of viral encephalopathy and retinopathy, a disease that causes mass mortalities in a wide range of fish species. Betanodaviruses are neurotropic viruses and their replication in the susceptible fish species seems to be almost entirely restricted to nerve tissue. However, none of the cell lines used for NNV propagation has a nervous origin. In this study, first we established a protocol for the primary culture of neurons from Senegalese sole, which made it possible to further study virus-host cell interactions. Then, we compared the replication of three NNV strains with different genotypes (SJNNV, RGNNV and a RGNNV/SJNNV reassortant strain) in sole neuron primary cultures and E-11 cells. In addition, to study how two amino acid substitutions at the c-terminal of the capsid protein (positions 247 and 270) affect the binding to cell receptors, a recombinant strain was also tested. The results show that sole neural cells enabled replication of all the tested NNV strains. However, the recombinant strain shows a clearly delayed replication when compared with the wt strain. This delay was not observed in virus replicating in E-11 cells, suggesting a viral interaction with different cell receptors. The establishment of a sole primary neuronal culture protocol provides an important tool for research into betanodavirus infection in soleThis work was supported by Grant AGL2014-54532-C2-2-R from the Ministerio the Innovación y Competitividad (Spain), cofunded by FEDERS

    Modification of betanodavirus virulence by substitutions in the 3’ terminal region of RNA2

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    Betanodaviruses have bi-segmented positive-sense RNA genomes, consisting of RNAs 1 and 2. For some members of the related genus alphanodavirus, the 3' terminal 50 nucleotides (nt) of RNA2, including a predicted stem-loop structure (3'SL), are essential for replication. We investigate the possible existence and role of a similar structure in a reassortant betanodavirus strain (RGNNV/SJNNV). In this study, we developed three recombinant strains containing nucleotide changes at positions 1408 and 1412. Predictive models showed stem-loop structures involving nt 1398–1421 of the natural reassortant whereas this structure is modified in the recombinant viruses harbouring point mutations r1408 and r1408– 1412, but not in r1412. Results obtained from infectivity assays showed differences between the reference strains and the mutants in both RNA1 and RNA2 synthesis. Moreover, an imbalance between the synthesis of both segments was demonstrated, mainly with the double mutant. All these results suggest an interaction between RNA1 and the 3' non-coding regions (3¢NCR) of RNA2. In addition, the significant attenuation of the virulence for Senegalese sole and the delayed replication of r1408–1412 in brain tissues may point to an interaction of RNA2 with host cellular proteinsThis work was supported by grant AGL2014-54532-C2-2-R from the Ministerio de Innovación y Competitividad (Spain), co-funded by FEDERS

    Validation of virtual water phantom software for pre-treatment verification of single-isocenter multiple-target stereotactic radiosurgery

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    Objectiu múltiple; SRS; Fantasma virtualObjetivo múltiple; SRS; Fantasma virtualMultiple‐target; SRS; Virtual phantomThe aim of this study was to benchmark the accuracy of the VIrtual Phantom Epid dose Reconstruction (VIPER) software for pre-treatment dosimetric verification of multiple-target stereotactic radiosurgery (SRS). VIPER is an EPID-based method to reconstruct a 3D dose distribution in a virtual phantom from in-air portal images. Validation of the VIPER dose calculation was assessed using several MLC-defined fields for a 6 MV photon beam. Central axis percent depth doses (PDDs) and output factors were measured with an ionization chamber in a water tank, while dose planes at a depth of 10 cm in a solid flat phantom were acquired with radiochromic films. The accuracy of VIPER for multiple-target SRS plan verification was benchmarked against Monte Carlo simulations. Eighteen multiple-target SRS plans designed with the Eclipse treatment planning system were mapped to a cylindrical water phantom. For each plan, the 3D dose distribution reconstructed by VIPER within the phantom was compared with the Monte Carlo simulation, using a 3D gamma analysis. Dose differences (VIPER vs. measurements) generally within 2% were found for the MLC-defined fields, while film dosimetry revealed gamma passing rates (GPRs) ≥95% for a 3%/1 mm criteria. For the 18 multiple-target SRS plans, average 3D GPRs greater than 93% and 98% for the 3%/2 mm and 5%/2 mm criteria, respectively. Our results validate the use of VIPER as a dosimetric verification tool for pre-treatment QA of single-isocenter multiple-target SRS plans. The method requires no setup time on the linac and results in an accurate 3D characterization of the delivered dose

    Análisis clínico y radiográfico de las técnicas ART y remoción químico-mecánica de caries - estudio piloto

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    Objetivo: Comparar clínica y radiográfi camente el Tratamiento Restaurador Atraumático (ART) y remoción químico- mecánica con Papacárie® en molares deciduos con caries oclusal verifi cando dolor,integridad clínica de las restauraciones y evolución de la lesión. Metodología: Estudio clínico randomizado en 16 molares deciduos, en pacientes de ambos sexos, con edades entre 3 y 6 años. Esos dientes fueron divididos aleatoriamente en G1 (n=8) ART convencional y G2 (n=8) Papacárie® y restaurados con ionómero de vidrio. La sintomatologia se analizó mediante la Escala de Evaluación Facial. Seis meses después se evaluó clínicamente la integridad de las restauraciones (Escala de Frencken) y radiográfi camente el aumento o no del área radiolúcida de la lesión. Resultados: No fue relatado dolor durante la ejecución de ambas técnicas. Luego de seis meses no hubo progresión de las lesiones y el material restaurador se mantuvo retenido adecuadamente. Conclusiones: Ambas técnicas demostraron éxito clínico y radiográfi co luego de seis meses de evaluación

    Evaluation of a New Monoclonal Chemiluminescent Immunoassay Stool Antigen Test for the Diagnosis of Helicobacter pylori Infection: A Spanish Multicentre Study

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    The stool antigen test (SAT) represents an attractive alternative for detection of Helicobacter pylori. The aim of this study was to assess the accuracy of a new SAT, the automated LIAISON(R) Meridian H. pylori SA based on monoclonal antibodies, compared to the defined gold standard C-13-urea breath test (UBT). This prospective multicentre study (nine Spanish centres) enrolled patients >= 18 years of age with clinical indication to perform UBT for the initial diagnosis and for confirmation of bacterial eradication. Two UBT methods were used: mass spectrometry (MS) including citric acid (CA) or infrared spectrophotometry (IRS) without CA. Overall, 307 patients (145 naive, 162 with confirmation of eradication) were analysed. Using recommended cut-off values (negative SAT = 1.10) the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 67%, 97%, 86%, 92% and 91%, respectively, obtaining an area under the receiver operating characteristic (ROC) curve (AUC) of 0.85. Twenty-eight patients, including seven false positives and 21 false negatives, presented a discordant result between SAT and UBT. Among the 21 false negatives, four of six tested with MS and 11 of 15 tested with IRS presented a borderline UBT delta value. In 25 discordant samples, PCR targeting H. pylori DNA was performed to re-assess positivity and SAT accuracy was re-analysed: sensitivity, specificity, positive predictive value, negative predictive value, accuracy and AUC were 94%, 97%, 86%, 99%, 97% and 0.96, respectively. The new LIAISON(R) Meridian H. pylori SA SAT showed a good accuracy for diagnosis of H. pylori infection
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