In vivo effect of deoxynivalenol (DON) naturally contaminated feed on porcine reproductive and respiratory syndrome virus (PRRSV) infection.

Deoxynivalenol (DON), also known as vomitoxin, is the most prevalent type B trichothecene mycotoxin worldwide. Pigs show a great sensitivity to DON, and because of the high proportion of grains in their diets, they are frequently exposed to this mycotoxin. The objective of this study was to determine the impact of DON naturally contaminated feed on porcine reproductive and respiratory syndrome virus (PRRSV) infection, the most important porcine viral pathogen in swine. Experimental infections were performed with 30 animals. Piglets were randomly divided into three groups of 10 animals based on DON content of diets (0, 2.5 and 3.5 mg/kg DON). All experimental groups were further divided into subgroups of 6 pigs and were inoculated with PRRSV. The remaining pigs (control) were sham-inoculated with PBS. Pigs were daily monitored for temperature, weight and clinical signs for 21 days. Blood samples were collected and tested for PRRSV RNA and for virus specific antibodies. Results of PRRSV infection showed that ingestion of diet highly contaminated with DON greatly increases the effect of PRRSV infection on weight gain, lung lesions and mortality, without increasing significantly viral replication, for which the tendency is rather directed toward a decrease of replication. These results suggest that PRRSV infection could exacerbate anorectic effect of DON, when ingested in large doses. Results also demonstrate a DON negative effect on PRRSV-specific humoral responses. This study demonstrate that high concentrations of DON naturally contaminated feed decreased the immune response against PRRSV and influenced the course of PRRSV infection in pigs.

In vitro effect of deoxynivalenol (DON) mycotoxin on porcine reproductive and respiratory syndrome virus replication.

Deoxynivalenol (DON) is a mycotoxin produced by Fusarium spp. Among monogastric farm animals, swine are the most susceptible to DON as it markedly reduces feed intake and decreases weight gain. DON has also been shown to increase susceptibility to viral infections; therefore the objective of this study was to investigate in vitro impact of DON on porcine reproductive and respiratory syndrome virus (PRRSV). Permissive cells were infected or not with PRRSV and were treated with increasing concentrations of DON. Cell survival and mortality were evaluated by determining the number of viable cells with a tetrazolium compound and by measuring lactate dehydrogenase (LDH) release, respectively. Virus titration and antiviral cytokines mRNA expression were evaluated by quantitative PCR. DON significantly affected the survival of noninfected cells in a dose dependent manner. However, DON concentrations between 140 and 280 significantly increased the survival of cells infected with PRRSV. These concentrations significantly decreased PRRSV replication by inducing a pro-inflammatory cytokines environment and an early activation of apoptosis, which in turn seem to interrupt viral replication. For the first time, this study showed that DON had significant effects on the survival of PRRSV infected cells and on virus replication, in a dose dependent manner.

Effect of deoxynivalenol (DON) mycotoxin on in vivo and in vitro porcine circovirus type 2 infections.

Deoxynivalenol (DON) is a mycotoxin produced by Fusarium spp and is a common contaminant of grains in North America. Among farm animals, swine are the most susceptible to DON because it markedly reduces feed intake and decreases weight gain. Porcine circovirus type 2 (PCV2) is the main causative agent of several syndromes in weaning piglets collectively known as porcine circovirus-associated disease (PCVAD). The objectives of this study were to investigate the impact of DON on PCV2 replication in NPTr permissive cell line, and to determine eventual potentiating effects of DON on PCV2 infection in pigs. Noninfected and infected cells with PCV2 were treated with increasing concentrations of DON (0, 70, 140, 280, 560, 1200 ng/mL) and cell survival and virus titer were evaluated 72 h postinfection. Thirty commercial piglets were randomly divided into 3 experimental groups of 10 animals based on DON content of served diets (0, 2.5 and 3.5 mg/kg DON). All groups were further divided into subgroups of 6 pigs and were inoculated with PCV2b virus. The remaining pigs (control) were sham-inoculated with PBS. In vitro results showed that low concentrations of DON could potentially increase PCV2 replication depending on virus genotype. In vivo results showed that even though viremia and lung viral load tend to be higher in animal ingesting DON contaminated diet at 2.5 mg/kg, DON had no significant effect on clinical manifestation of PCVAD in PCV2b infected animals. DON has neither in vitro nor in vivo clear potentiating effects in the development of porcine circovirus infection despite slight increases in viral replication.

In vitro and in vivo effects of deoxynivalenol (DON) mycotoxin on porcine reproductive and respiratory syndrome virus (PRRSV) in piglets

Les récoltes de céréales sont souvent contaminées par des moisissures qui se développent pendant la récolte et l’entreposage et produisent des métabolites secondaires appelés mycotoxines. Le porc est reconnu pour être sensible au déoxynivalénol (DON). L’infection virale la plus importante chez le porc est causée par le virus du syndrome reproducteur et respiratoire porcin (VSRRP). Celui-ci provoque un syndrome grippal et des troubles de reproduction. L’objectif du présent projet était de déterminer l'effet in vitro de DON sur la réplication du VSRRP dans de lignées cellulaires permissives, MARC-145 et PAM, et déterminer in vivo l'impact de DON dans des aliments naturellement contaminés sur l’infection au VSRRP chez le porcelet. Tout d’abord, les cellules ont été incubées avec des doses croissantes de DON et ont été infectées avec du VSRRP pour évaluer la viabilité et la mortalité cellulaire, la réplication virale et l’expression de cytokines. Les résultats ont montré que les concentrations de DON de 560ng/ml et plus affectaient significativement la survie des cellules MARC-145 et PAM infectées par le VSRRP. En revanche, il y avait une augmentation significative de la viabilité et une réduction de la mortalité cellulaire à des concentrations de DON de 140 à 280 ng/ml pour les cellules PAM et de 70 à 280 ng/ml pour les cellules MARC-145 avec une réduction de l'effet cytopathique provoqué parle VSRRP. Au niveau in vivo, 30 porcelets divisés en 3 groupes de 10 porcelets et nourris pendant 2 semaines avec 3 différentes diètes naturellement ont été contaminées avec DON (0; 2,5 et 3,5 mg/kg). Les porcelets ont été subdivisés en 6 groupes, 3 groupes de 6 porcelets et ont été exposés au DON pendant 2 semaines et infectés par voie intratrachéale et intramusculaire avec le virus. Les 3 autres groupes de 4 porcelets servaient de contrôle non infectés. Les signes cliniques ont été enregistrés pendant 21 jours. La virémie a été évaluée par PCR. À la fin de l’expérimentation, les porcelets ont été euthanasiés et les lésions pulmonaires ont été évaluées. Les résultats ont montré que l’ingestion de DON à 3,5 mg/kg a augmenté l’effet du VSRRP sur la sévérité des signes cliniques, les lésions pulmonaires et la mortalité. L’ingestion de DON à 2,5 mg/kg a entrainé une augmentation de la virémie au jour 3 après l’infection mais sans impact sur les signes cliniques et les lésions pulmonaires. Mot clés: DON, VSRRP, MARC-145, PAM, effet cytopathique, cytokines, PCR

Don Giovanni. Il dissoluto punito ovvero la possibilità e lo spostamento

Traduction du titre : Don Juan. Le dissolu puni ou bien la possibilité et le déplacement.

Deoxynivalenol (DON) naturally contaminated feed impairs the immune response induced by porcine reproductive and respiratory syndrome virus (PRRSV) live attenuated vaccine

Cereal commodities are frequently contaminated with mycotoxins produced by the secondary metabolism of fungal infection. Among these contaminants, deoxynivalenol (DON), also known as vomitoxin, is the most prevalent type B trichothecene mycotoxin worldwide. Pigs are very sensitive to the toxic effects of DON and are frequently exposed to naturally contaminated feed. Recently, DON naturally contaminated feed has been shown to decrease porcine reproductive and respiratory syndrome virus (PRRSV) specific antibody responses following experimental infection. The objective of this study was to determine the impact of DON naturally contaminated feed on the immune response generated following vaccination with PRRSV live attenuated vaccine. Eighteen pigs were randomly divided into three experimental groups of 6 animals based on DON content of the diets (0, 2.5 and 3.5 mg DON/kg). They were fed these rations one week prior to the vaccination and for all the duration of the immune response evaluation. All pigs were vaccinated intra-muscularly with one dose of Ingelvac® PRRSV modified live vaccine (MLV). Blood samples were collected at day −1, 6, 13, 20, 27 and 35 post vaccination (pv) and tested for PRRSV RNA by RT-qPCR and for virus specific antibodies by ELISA. Results showed that ingestion of DON-contaminated diets significantly decreased PRRSV viremia. All pigs fed control diet were viremic while only 1 (17%) and 3 (50%) out of 6 pigs were viremic in the groups receiving 3.5 and 2.5 mg of DON/kg, respectively. Subsequently, all pigs fed control diet developed PRRSV specific antibodies while only viremic pigs that were fed contaminated diets have developed PRRSV specific antibodies. These results suggest that feeding pigs with DON-contaminated diet could inhibit vaccination efficiency of PRRSV MLV by severely impairing viral replication.

Los sistemas de econom??a de fichas en el ??rea de Educaci??n F??sica : los don fenomenales

Se presenta experiencia educativa que propone el sistema de econom??a de fichas para motivar al alumnado en el ??rea de la Educaci??n F??sica. Se realiza en el CEIP San Isidro Labrador en El Chaparral, Granada. Los objetivos son: erradicar conductas no deseables en el ??mbito escolar, tratando de lograr una transferencia a la vida real de las conductas positivas aprendidas; paliar deficiencias sociales en cuanto a h??bitos diversos, haciendo especial hincapi?? en aquellos relacionados con la higiene y el aseo personal; interiorizar en el alumnado conductas que por su ??ndole se observen como de especial trascendencia.

Don Quijote busca a Dulcinea

Cuento con pictogramas sobre Don Quijote y Dulcinea realizado por alumnos de educaci??n infantil que versiona la historia de amor de la novela de Cervantes conmemorando la celebraci??n del 400 aniversario de su primera edici??n.

Don Borja y Do??a Blanca : taller literario con alumnado de atenci??n a la diversidad

Las ilustraciones son de Diego Corbal??n Hern??ndez

Seis escenas biográficas sobre la vida de Don Diego Saavedra y Fajardo.

Conjunto de seis narraciones (cuentos) para ser leídos en clase sobre personajes y sucesos históricos con un resumen de los acontecimientos más importantes acaecidos en el año en el que se enmarca temporalmente la narración y una sucinta biografía del personaje. En las notas explicativas se aclara el significado de palabras relevantes para la comprensión de la historia. El objetivo es dar a conocer la vida y la obra de Diego Saavedra y Fajardo, ilustre político y diplomático murciano en los reinados de Felipe III y Felipe IV..

Don't be an Alien. 'No seas un Alien'

Resumen basado en el de la publicaci??n

El pensamiento pedagógico del arabista Don Julian Ribera.

Mostrar, a través de los textos de Ribera, la relevancia de su pensamiento. Se aborda primero su pensamiento pedagógico, esencialmente crítico y original y después, los motivos e influencias en su pensamiento, concluyendo con la vigencia de su obra en la actualidad. Bibliografía. Estudio de la bibliografía. El estudio de la figura de Don Julian Ribera durante su vida pública (1887-1927), nos da a conocer las cuatro dimensiones más a resaltar: su talante crítico lo conduce al estudio del fenómeno educativo en la realidad actual, descubriendo el fracaso de las instituciones pedagógicas, que no crean hombres magistrales, por lo que pide un saber más espontáneo, esto nos lleva a su fe en lo natural, es decir, en el saber práctico frente al teórico, para lo que sugiere un camino que es el arte de aprender junto al de enseñar, quedando todo plasmado en su proyecto pedagógico.

Don Jos?? P??rez Jim??nez (1887-1967)

Resumen tomado de la publicaci??n

Plan exportador para la empresa Croc Ltda. en su línea de productos "Don Chicharrón"

Este trabajo de grado pretende realizar un Plan Exportador mediante el cual sea posible determinar si la empresa Croc Ltda. está o no preparada para exportar su línea de producto “Don Chicharrón”. El proceso se desarrolla a través de: Descripción del estado actual de la empresa, Realización del “Diagnóstico de la Empresa”, Inteligencia de Mercados sumado a la Matriz de Proexport y finalmente el Diseño del Plan de Logística incluido una simulación de costos de exportación al mercado objetivo; en este caso Perú. Como resultado de la investigación se logro determinar que la empresa Croc Ltda. se encuentra en un nivel medio de internacionalización debido a que existen falencias en la ejecución de la Gestión de Mercados, Gestión de Operaciones, Gestión Financiera y Gestión de Talento Humano. Después de seleccionar posibles países para exportar y variables a investigar para construir la “Matriz de Proexport” se concluyo el país objetivo, alterno y contingente; Perú, México y España respectivamente. De esta manera, se comienza la investigación de mercados para los tres países. Para finalizar, en el diseño del plan de logística se determino que la mejor forma para exportar “Don Chicharrón” al Perú es por vía marítima a través del Incoterm DDU (Delivered Duty Unpaid). Es así como se puede concluir este trabajo de grado, y darle cierre a la investigación y entregar a la empresa Croc Ltda. en su línea de productos “Don Chicharrón” un Plan Exportador para que se pueda hacer uso de éste en su proceso de internacionalización.

Don Llorenç Maria Duran i Coli : sus aportaciones a la renovación educativa mallorquina.

Resumen tomado de la publicación. Incluye una conferencia del Llorenç Duran impartida en 1977 en referencia a una experiencia de escuela activa en el año 1933, y que hasta ahora estaba inédita