Early Challenge with Oncogenic Marek's Disease Virus Does Not Interfere with Load of Marek's Disease Vaccines DNA in the Feather Pulp at 7 Days of Age.

In the last decade, monitoring Marek's disease (MD) vaccination by real-time PCR has become a common practice. Evaluating in vivo replication of MD vaccines in the feather pulp (FP) at 7 days of age provides information on how well a flock has been vaccinated. Factors such as vaccine dose, combination with other vaccines, age and route of vaccination, and the origin of the vaccine can influence the results and need to be taken into consideration. Early infection with oncogenic MD virus (MDV) could also affect how vaccines replicate in the first week and therefore might influence the results. The objective of this study was to evaluate if coinfection with oncogenic MDV could affect MD vaccine DNA viral load in the FP at 7 days of age. A retrospective study was done using data from nine animal experiments (46 treatment groups) in which chickens were vaccinated against MD either in ovo or at 1 day of age and challenged with various oncogenic strains at 1 day of age by contact. In each experiment, vaccinated but not challenged groups were used as controls. Replication of MD vaccine was evaluated in samples of FP collected at 7 days of age by real-time PCR, and percentage of positives and vaccine load were analyzed. Our results show that CVI-988 (13 treatment groups), SB-1 (six treatment groups), and in most cases turkey herpesvirus (HVT; 24 out of 27 treatment groups) replication was not affected by early infection with oncogenic MDV. There were three treatment groups in which HVT replication differed between challenged and unchallenged chickens, however the effect was not clear; replication of HVT in nonchallenged chickens was higher (one treatment group) or lower (two treatment groups) than in challenged chickens and factors other than coinfection with MDV might have contributed to such differences.

Nota de investigación­El desafío temprano con un virus oncogénico de la enfermedad de Marek no interfiere con la carga de ADN de las vacunas contra la enfermedad de Marek en la pulpa de la pluma a los siete días de edad. En la última década, el seguimiento de la vacunación contra la enfermedad de Marek (EM) mediante PCR en tiempo real se ha convertido en una práctica común. La evaluación de la replicación in vivo de las vacunas de Marek en la pulpa de la pluma (FP) a los siete días de edad proporciona información sobre qué tan bien se ha vacunado una parvada. Factores como la dosis de la vacuna, la combinación con otras vacunas, la edad, la vía de vacunación y el origen de la vacuna pueden influir en los resultados y deben tenerse en cuenta. La infección temprana con un virus de Marek oncogénico (MDV) también podría afectar la forma en que las vacunas se replican en la primera semana y por lo tanto, podría influir en los resultados. El objetivo de este estudio fue evaluar si la coinfección con un virus de Marek oncogénico podría afectar la carga viral del ADN de la vacuna de Marek en la pulpa de la pluma a los siete días de edad. Se realizó un estudio retrospectivo utilizando datos de nueve experimentos con animales (46 grupos de tratamientos) en los que se vacunaron pollos contra la enfermedad de Marek ya sea in ovo o al día de edad y se desafiaron con varias cepas oncogénicas al día de edad por contacto. En cada experimento, se utilizaron como controles los grupos vacunados, pero no desafiados. Se evaluó la replicación de la vacuna de Marek en muestras de pulpa de la pluma recolectadas a los siete días de edad por PCR en tiempo real, y se analizó el porcentaje de positivos y la carga vacunal. Los resultados de este estudio muestran que la replicación de la cepa CVI-988 (13 grupos de tratamiento), la cepa SB-1 (seis grupos de tratamiento) y en la mayoría de los casos, del herpesvirus de pavo (HVT; 24 de 27 grupos de tratamiento) no se vio afectada por la infección temprana con un virus de Marek oncogénico. Hubo tres grupos de tratamiento en los que la replicación de la vacuna HVT difería entre pollos desafiados y no desafiados, sin embargo, el efecto no fue claro; la replicación de la vacuna HVT en pollos no desafiados fue mayor (un grupo de tratamiento) o menor (dos grupos de tratamiento) que en los pollos desafiados y otros factores distintos a la coinfección con el virus de la enfermedad de Marek podrían haber contribuido a tales diferencias.

Characterization of Md5-BAC-REV-LTR virus as Marek's disease vaccine in commercial meat-type chickens: protection and immunosuppression.

Md5-BAC-REV-LTR is a recombinant Marek's disease virus (MDV), with an insertion of the long terminal repeat (LTR) of reticuloendotheliosis virus (REV) into the genome of the highly virulent MDV strain rMd5. It has been shown that Md5-BAC-REV-LTR does not induce tumours and confers high protection against challenge with MDV in 15 × 7 chickens. The objective of the present study was to evaluate the protection and safety (in terms of oncogenicity and immunosuppression) of Md5-BAC-REV-LTR in commercial meat-type chickens bearing maternal antibodies against MDV. Our results show that sub-cutaneous administration of Md5-BAC-REV-LTR at 1 day of age conferred high protection (protection index PI = 84.2) against an early challenge (1 day) by contact exposure to shedder birds infected with the vv+ MDV 648A strain. In such stringent challenge conditions, Md5-BAC-REV-LTR was more protective than a commercial CVI988 (PI = 12.4) and similar to the experimental vaccine Md5-BACΔmeq (PI = 92.4). Furthermore, Md5-BAC-REV-LTR did not induce either tumours or immunosuppression in this study. Immunosuppression was evaluated by the relative lymphoid organ weights and also by the ability of the vaccine to induce late-MDV-induced immunosuppression associated with reactivation of the virus. This study shows that Md5-BAC-REV-LTR has the potential to be used as a MD vaccine and is highly protective against early challenge with vv+ MDV.RESEARCH HIGHLIGHTSMd5-BAC-REV-LTR is highly protective against early challenge with vv+ MDV in commercial meat-type chickens.Md5-BAC-REV-LTR does not cause early immunosuppression.Md5-BAC-REV-LTR does not cause late immunosuppression.Unlike other serotype 1 vaccines, Md5-BAC-REV-LTR is not detected in feather pulp at 7 days post vaccination.

Replication of Marek's disease vaccines in turkey embryos and their effect on TLR-3 and IFN-γ transcripts.

Understanding the pathogenesis of herpesvirus of turkeys (HVT) in its natural host is necessary before recombinant HVT (rHVT) can be used efficiently in turkey flocks. The objectives of this study were to evaluate when commercial turkey flocks get infected with wild type HVT, to study replication of HVT (conventional and recombinant rHVT-Newcastle disease, rHVT-ND) and other Marek's disease (MD) vaccines (SB-1 and CVI988) in turkey embryonic tissues, and to evaluate the expression of TLR-3 and IFN-γ in the lung and spleen of one-day-old turkeys after in ovo vaccination with MD vaccines. Our results demonstrated that commercial turkeys got exposed to wild type HVT within the first days of life; therefore, there is a potential of interaction between wild type HVT and rHVT when administered at day of age. On the other hand, all evaluated vaccines (especially HVT and rHVT-ND) replicated very well in turkey embryonic tissues. In ovo vaccination with HVT and CVI988 increased transcription of TLR-3 in the spleen of one-day-old turkeys. However, no effect on the transcription of TLR-3 or IFN-γ in the lungs and IFN-γ in the spleen in newly hatched turkeys was detected in the present study. Because of the limitations of evaluated genes, timepoints, and studied tissues, future studies are warranted to better understand the effect of MD vaccines on the turkey embryo immune responses.RESEARCH HIGHLIGHTS Commercial turkey flocks get infected with wild type HVT within the first days of life.HVT and rHVT replicates readily in turkey embryonic tissues.SB-1 and CVI988 also replicate in turkey embryonic tissues, but at lower rates than HVT and rHVT.HVT and CVI988 increase transcription of TLR-3 in the spleen.

Abordaje mutidisciplinar en las unidades de asma grave / Multidisciplinary approach in the severe asthma units

El asma es una enfermedad crónica muy prevalente que genera un consumo importante de recursos sanitarios. El mal manejo de estos enfermos conlleva a un inadecuado control de la enfermedad, a un mayor coste sanitario y a un aumento de la morbimortalidad. La creación de unidades multidisciplinares es muy recomendable, principalmente en las formas más graves y ha demostrado una mejoría asistencial (efectividad), reduciendo notablemente los costes económicos de la enfermedad (eficiencia). Dichas unidades precisan un coordinador (neumólogo) que sea conocedor de todos los aspectos del asma y que organice todo el cuidado, incluyendo al resto de las especialidades implicadas (alergólogos, otorrinolaringólogos, gastroenterólogos, endocrinos, psicólogos y psiquiatras)

Asthma is a very prevalent chronic disease that generates a significant consumption of health resources. The mismanagement of these patients leads to poor control of the disease, a higher health cost and an increase in morbidity and mortality. The creation of multidisciplinary units is highly recommended, mainly in the most severe forms. It requires a coordinator (pneumologist) who is knowledgeable about all aspects of asthma and who organizes all the care, including the rest of the specialties involved (allergists, otolaryngologists, gastroenterologists, endocrines, psychologists and psychiatrists). The creation of these units has shown a welfare improvement (effectiveness), significantly reducing the economic costs of the disease (efficiency)

Evaluation of Factors That Influence Dose Variability of Marek's Disease Vaccines.

Marek's disease (MD) vaccines are cell-associated and require special handling and care during administration. Vaccine dose is evaluated by plaque assay and is indicated as the number of plaque-forming units (PFUs) per dose. The objectives of this study were to evaluate the dose variability within each vial of MD vaccines and to assess those factors (from both manufacturing and handling and administration of the vaccine) that could affect vaccine dose variability. Three experiments were conducted. Experiment 1 was to evaluate dose variability in 36 MD vaccine vials and the effect of manufacturing factors on dose variability. Vaccines were titrated 10 times. Dose variability was measured as the coefficient of variability (CV) calculated as standard deviation divided by average PFU and multiplied by 100. Our results showed that all evaluated vaccines had levels of CV ranging from 10% to 34%. Variability existed regardless of manufacturer, vaccine serotype, and batch. Experiment 2 was conducted to evaluate the effect of infectivity rate (IR) on CV. IR was artificially reduced by adding noninfected chicken embryo fibroblast to the reconstituted vaccine before titration. Our results showed that decreased IR results in higher CV. Experiment 3 was to evaluate the handling and administration factors (time and mixing during administration) on CV. Our results showed that CV tends to increase with time and that this effect is more remarkable if vaccines were not mixed. Our study emphasizes the relevance of proper handling of MD vaccines and shows that dose variability can jeopardize the uniformity of vaccination in a flock and therefore the success of vaccination.

Evaluación de factores que influyen en la variabilidad de las dosis de las vacunas contra la enfermedad de Marek. Las vacunas contra la enfermedad de Marek (MD) están asociadas a células y requieren un manejo y cuidado especiales durante la administración. La dosis de la vacuna se evalúa mediante un ensayo de placa y se indica como el número de unidades formadoras de placa (UFP) por dosis. Los objetivos de este estudio fueron evaluar la variabilidad de la dosis dentro de cada vial de vacunas contra la enfermedad de Marek y evaluar los factores (tanto de fabricación como de manipulación/administración de la vacuna) que podrían afectar la variabilidad de la dosis de la vacuna. Se realizaron tres experimentos. El experimento número 1 consistió en evaluar la variabilidad de la dosis en 36 viales de vacuna de Marek y el efecto de los factores de fabricación en la variabilidad de la dosis. Las vacunas fueron tituladas 10 veces. La variabilidad de la dosis se midió como el coeficiente de variación (CV) calculado como desviación estándar dividido por las UFP promedio y multiplicado por 100. Nuestros resultados mostraron que todas las vacunas evaluadas tenían coeficientes de variación que variaban del 10% al 34%. La variabilidad existía independientemente del fabricante, el serotipo de la vacuna y el lote. El experimento número 2 se realizó para evaluar el efecto de la tasa de infectividad (IR) en el coeficiente de variación. La tasa de infectividad se redujo artificialmente mediante la adición de fibroblastos de embrión de pollo no infectados a la vacuna reconstituida antes de la valoración. Los resultados mostraron que la disminución en la tasa de infectividad resulta en mayores coeficientes de variación. El experimento número 3 consistió en evaluar los factores de manipulación y administración (tiempo y mezclado durante la administración) sobre los coeficientes de variación. Nuestros resultados mostraron que el coeficiente de variación tiende a aumentar con el tiempo y que este efecto es más notable si las vacunas no se mezclan. Este estudio enfatiza la relevancia del manejo adecuado de las vacunas contra la enfermedad de Marek y muestra que la variabilidad de la dosis puede poner en peligro la uniformidad de la vacunación en una parvada y por lo tanto el éxito de la vacunación.

Highly virulent Marek's disease virus strains affect T lymphocyte function and viability of splenocytes in commercial meat-type chickens.

In previous studies, we have demonstrated that very virulent plus Marek's disease viruses (vv+MDV) are highly immunosuppressive in commercial meat-type chickens. The specific objectives of this work were to evaluate if vv+MDV immunosuppression (MDV-IS) is induced by reduction of lymphocyte responsiveness and/or viability. Three experiments were conducted to (i) compare vv+MDV 686 with a partially attenuated 686-BAC; (ii) compare vv+MDV strains (648A and 686) with vMDV (GA) and vvMDV (Md5); and (iii) compare chickens vaccinated with Md5-BACΔMEQ and with CVI988 + HVT. In each experiment, spleens were collected at 28-30 days post infection and lymphocytes were isolated and investigated in three ways: their proliferative response to Concanavalin A (ConA) was analysed by MTT proliferation assay; cell death, and expression of CD45 and MHC-I was studied by flow cytometry; and MHC-IA and ß-2 microglobulin (B2M) expression was evaluated by real time RT-PCR. Splenocytes of chickens inoculated with vv+MDV were severely impaired to proliferate when exposed to ConA. Furthermore, vv+MDV induced severe splenocyte death that did not occur after infection with v or vvMDV strains. Vaccination with CVI988 + HVT, and at less level with Md5-BACΔMEQ reduced these negative effects. This is in contrast to our previous results in which Md5-BACΔMEQ but not CVI988 + HVT protected against MDV-IS suggesting that although cell death and decrease lymphocyte function seem to be related to MDV virulence and certainly will be associated with immunosuppression, they might not fully explain the previously reported MDV-IS. RESEARCH HIGHLIGHTS vv+MDV induces extensive death in splenocytes in meat-type chickens 28-30 dpi. vv+MDV impairs lymphocyte function in meat-type chickens 28-30 dpi. Vaccination protects against splenocyte death and reduced lymphocyte function. Cell lysis and reduced lymphocyte function do not fully explain MDV-IS.

Study of Efficacy and Replication of Recombinant Vector Vaccines by Using Turkey Herpesvirus Combined with Other Marek's Disease Vaccines.

Several recombinant turkey herpesviruses (rHVTs) have been developed within the past decades, and they are now used commercially worldwide. In broiler chickens, rHVTs are usually administered alone, but in long-living birds they are used in combination with Marek's disease (MD) vaccines of other serotypes (i.e., CVI988). The objectives of this work were to 1) evaluate protection against MD conferred by HVT and two rHVTs when combined with CVI988 and 2) optimize the use of rHVT in combination with CVI988 to maximize replication of rHVT without compromising MD protection. Various vaccine protocols, all using rHVT or HVT at the recommended dose (RD), were evaluated. Protocols evaluated included in ovo vaccination with HVT+CVI988 or rHVT+CVI988 (using either the double dose [DD] or the RD of CVI988), day of age vaccination of rHVT+CVI988 at DD, and revaccination protocols using rHVT in ovo followed by CVI988 at DD at day of age. Our results show that, when combined with CVI988, HVT and rHVTs confer a similar level of protection against MD (>90%) regardless of whether CVI988 was used at RD or at DD. However, the combination of rHVT with CVI988 at DD resulted in reduced replication rates of rHVT (60%-76% vs. 95%-100%). Our results show that such a negative effect could be avoided without jeopardizing MD protection by administering CVI988 at RD (if combined in ovo with rHVT) or administered rHVT first in ovo followed by CVI988 at DD at day of age.

Estudio de la eficacia y replicación de vacunas con vectores recombinantes mediante el uso del virus del herpes del pavo combinado con otras vacunas contra la enfermedad de Marek. Varios herpesvirus de pavo recombinantes (rHVT) se han desarrollado en las últimas décadas y ahora se utilizan comercialmente en todo el mundo. En pollos de engorde, los rHVT generalmente se administran solos, pero en aves de vida larga se usan en combinación con vacunas contra la enfermedad de Marek (MD) de otros serotipos (especialmente, CVI988). Los objetivos de este trabajo fueron 1) evaluar la protección contra la enfermedad de Marek conferida por herpesvirus de pavo (HVT9 y por dos rHVT cuando se combinan con la cepa CVI988 y 2) optimizar el uso de rHVT en combinación con la cepa CVI988 para maximizar la replicación de rHVT sin comprometer la protección contra la enfermedad de Marek. Se evaluaron varios protocolos de vacunas, todos con rHVT o con HVT a la dosis recomendada (RD). Los protocolos evaluados incluyeron la vacunación in ovo con HVT + CVI988 o rHVT + CVI988 (usando la dosis doble o la dosis recomendada de la cepa CVI988), la vacunación al día de la edad con rHVT + CVI988 con dosis doble, y los protocolos de revacunación usando rHVT seguido por la cepa CVI988 con dosis doble al día de edad. Los resultados muestran que cuando se combinan con CVI988, HVT y rHVT confieren un nivel de protección similar contra la enfermedad de Marek (> 90%) independientemente de que la cepa CVI988 se haya usado a la dosis recomendada o con dosis doble. Sin embargo, la combinación de rHVT con la cepa CVI988 con doble dosis produjo una reducción en las tasas de replicación de rHVT (60% ­76% vs. 95% ­100%). Estos resultados muestran que dicho efecto negativo podría evitarse sin poner en peligro la protección contra la enfermedad de Marek administrando la cepa CVI988 a la dosis recomendada (si se combina in ovo con rHVT) o administrando rHVT primero in ovo, seguido de CVI988 con dosis doble al día de la edad.

Virus-Induced Immunosuppression in Chickens.

A healthy immune system is a cornerstone for poultry production. Any factor diminishing the immune responses will affect production parameters and increase cost. There are numerous factors, infectious and noninfectious, causing immunosuppression (IS) in chickens. This paper reviews the three viral diseases that most commonly induce IS or subclinical IS in chickens: Marek's disease virus (MDV), chicken infectious anemia virus (CIAV), and infectious bursal disease virus (IBDV), as well as the interactions among them. MDV-induced IS (MDV-IS) affects both humoral and cellular immune responses. It is very complex, poorly understood, and in many cases underdiagnosed. Vaccination protects against some but not all aspects of MDV-IS. CIAV induces apoptosis of the hemocytoblasts resulting in anemia, hemorrhages, and increased susceptibility to bacterial infections. It also causes apoptosis of thymocytes and dividing T lymphocytes, affecting T helper functions, which are essential for antibody production and cytotoxic T lymphocyte (CTL) functions. Control of CIAV is based on vaccination of breeders and maternal antibodies (MAbs). However, subclinical IS can occur after MAbs wane. IBDV infection affects the innate immune responses during virus replication and humoral immune responses as a consequence of the destruction of B-cell populations. Vaccines with various levels of attenuation are used to control IBDV. Interactions with MAbs and residual virulence of the vaccines need to be considered when designing vaccination plans. The interaction between IBDV, CIAV, and MDV is critical although underestimated in many cases. A proper control of IBDV is a must to have proper humoral immune responses needed to control CIAV. Equally, long-term control of MDV is not possible if chickens are coinfected with CIAV, as CIAV jeopardizes CTL functions critical for MDV control.

Efficacy of Various HVT Vaccines (Conventional and Recombinant) Against Marek's Disease in Broiler Chickens: Effect of Dose and Age of Vaccination.

Herpesvirus of turkeys (HVT) has been successfully used as a Marek's disease (MD) vaccine for more than 40 yr. Either alone (broiler chickens) or in combination with vaccines of other serotypes (broilers, broiler breeders, and layers), HVT is used worldwide. In recent years, several vector vaccines based on HVT (rHVT) have been developed. At present, there are both conventional HVT and rHVTs in the market, and it is unknown if all of them confer the same level of protection against MD. The objective of this study was to further characterize the protection conferred by two conventional HVTs (HVT-A and HVT-B) and three recombinant HVTs (rHVT-B, rHVT-C, and rHVT-D) against MD in broiler chickens. In a first study we evaluated the efficacy of two conventional HVTs (HVT-A and HVT-B) administered at different doses (475, 1500, and 4000 PFU) at day of age on the ability to protect against an early challenge with very virulent plus strain 645. In a second experiment we evaluated the protection ability of several HVTs (both conventional and recombinant) when administered in ovo at a dose of 1500 PFU using the same challenge model. Our results show that each HVT product is unique, regardless of being conventional or recombinant, in their ability to protect against MD and might require different PFUs to achieve its maximum efficacy. In Experiment 1, HVT-A at 4000 PFU conferred higher protection (protection index [PI] = 63) than any of the other vaccine protocols (PI ranging from 36 to 47). In Experiment 2, significant differences were found among vaccine protocols with PI varying from 66 (HVT-A) to 15 (rHVT-D). Our results show that each HVT is unique and age at vaccination and vaccine dose greatly affected vaccine efficacy. Furthermore, they highlight the need of following manufacturer's recommendations.

Asma / No disponible

No disponible

Assessment of cognition and language in the early diagnosis of autism spectrum disorder: usefulness of the Bayley Scales of infant and toddler development, third edition.

BACKGROUND: The aim of this study was to test the usefulness of the Cognitive and Language scales Bayley-III in the early assessment of cognitive and language functions in the context of an autism spectrum disorder (ASD) diagnosis. This paper focuses on the application of the Bayley-III and studies the predictive value of the test result in children with ASD with different levels of verbal ability. METHOD: A sample of 135 children (121 boys, 14 girls) with a confirmed ASD diagnosis at age 4 years were assessed with the Bayley-III before 42 months of age (m = 36.49, s = 4.46) and later with other rating scales of different psychological and psycholinguistic functions as part of a longitudinal study [McCarthy Scales of Children's Abilities (MSCA) (n = 48, 90% boys), Kaufman Assessment Battery for Children (K-ABC) (n = 38, 87% boys) or Illinois Test of Psycholinguistic Abilities (ITPA) (n = 44, 89% boys)]. Age assessment in months: MSCA (m = 48.80, s = 3.33), K-ABC (m = 51.80, s = 7.17) and ITPA (m = 54.48, s = 3.34). RESULTS: Lower scores on the cognitive and language Bayley-III scales before 3.5 years of age predicted lower cognitive and oral language levels at 4 years of age. A significant correlation was found between the Cognitive Bayley-III Scale and the General Cognitive MSCA Scale, and with the Compound K-ABC Mental Processing. An association between the nonverbal cognitive level and oral language level acquired at 4 years of age was found. CONCLUSIONS: The Bayley-III is a useful instrument in cognitive and language assessment of ASD.

Persistence and Retention of Porcine Reproductive and Respiratory Syndrome Virus in Stable Flies (Diptera: Muscidae).

We investigated the acquisition of porcine reproductive and respiratory syndrome (PRRS) virus by the stable fly (Diptera: Muscidae; Stomoxys calcitrans (L.)) through a bloodmeal, and virus persistence in the digestive organs of the fly using virus isolation and quantitative reverse-transcription PCR (qRT-PCR). Stable flies were fed blood containing live virus, modified live vaccine virus, chemically inactivated virus, or no virus. Stable flies acquired PRRSV from the bloodmeal and the amount of virus in the flies declined with time, indicating virus did not replicate in fly digestive tissues. Virus RNA was recovered from the flies fed live virus up to 24 h postfeeding using virus isolation techniques and 96 h using qRT-PCR. We further examined the fate of PRRSV in the hemolymph of the flies following intrathoracic injection to bypass the midgut barrier. PRRSV was detected in intrathoracically inoculated adult stable flies for 10 d using qRT-PCR. In contrast to what we observed in the digestive tract, detectable virus quantities in the intrathoracically inoculated stable flies followed an exponential decay curve. The amount of virus decreased fourfold in the first 3 d and remained stable thereafter, up to 10 d.

A human iPSC model of Ligase IV deficiency reveals an important role for NHEJ-mediated-DSB repair in the survival and genomic stability of induced pluripotent stem cells and emerging haematopoietic progenitors.

DNA double strand breaks (DSBs) are the most common form of DNA damage and are repaired by non-homologous-end-joining (NHEJ) or homologous recombination (HR). Several protein components function in NHEJ, and of these, DNA Ligase IV is essential for performing the final 'end-joining' step. Mutations in DNA Ligase IV result in LIG4 syndrome, which is characterised by growth defects, microcephaly, reduced number of blood cells, increased predisposition to leukaemia and variable degrees of immunodeficiency. In this manuscript, we report the creation of a human induced pluripotent stem cell (iPSC) model of LIG4 deficiency, which accurately replicates the DSB repair phenotype of LIG4 patients. Our findings demonstrate that impairment of NHEJ-mediated-DSB repair in human iPSC results in accumulation of DSBs and enhanced apoptosis, thus providing new insights into likely mechanisms used by pluripotent stem cells to maintain their genomic integrity. Defects in NHEJ-mediated-DSB repair also led to a significant decrease in reprogramming efficiency of human cells and accumulation of chromosomal abnormalities, suggesting a key role for NHEJ in somatic cell reprogramming and providing insights for future cell based therapies for applications of LIG4-iPSCs. Although haematopoietic specification of LIG4-iPSC is not affected per se, the emerging haematopoietic progenitors show a high accumulation of DSBs and enhanced apoptosis, resulting in reduced numbers of mature haematopoietic cells. Together our findings provide new insights into the role of NHEJ-mediated-DSB repair in the survival and differentiation of progenitor cells, which likely underlies the developmental abnormalities observed in many DNA damage disorders. In addition, our findings are important for understanding how genomic instability arises in pluripotent stem cells and for defining appropriate culture conditions that restrict DNA damage and result in ex vivo expansion of stem cells with intact genomes.

Papel de los anticolinérgicos en la enfermedad asmática / No disponible

Los anticolinérgicos (AC) son escasamente utilizados en el asma a diferencia de lo que ocurre en la enfermedad pulmonar obstructiva crónica (EPOC) en la que está muy extendido su uso. Las directrices para el manejo del asma recomiendan el uso de AC únicamente durante las exacerbaciones, ya que los beneficios del uso de estos fármacos en la fase estable del asma aún no se han establecido. Estudios recientes han sugerido la implicación del sistema colinérgico en la fisiopatología y la patogenia del asma, al demostrar la capacidad de las células epiteliales bronquiales e inflamatorias para sintetizar y liberar acetilcolina (ACh) y para expresar receptores muscarínicos. La implicación de estos receptores en la modulación de determinados mecanismos inflamatorios en el asma y en los cambios estructurales que conducen al remodelado apoya este concepto. Estas consideraciones sugieren que los AC que actúan bloqueando determinados receptores muscarínicos constituirían una alternativa terapéutica en esta enfermedad. En este sentido, una serie de trabajos, recientemente publicados, han demostrado que los AC podrían ser eficaces en el tratamiento del asma estable (AU)

Anticholinergic agents are not usually chose for asthma treatment, compared with its widely use in Chronic Obstructive Pulmonary Disease. The asthma guidelines only recommend its use in acute asthma exacerbations, and has not been fully investigated its role in stable asthma. Recent studies have related the cholinergic system and asthma pathophysiology, as it has been observed the secretion of acetylcholine and the expression of muscarinic receptors by the airway ephitelium cells and inflammatory cells. These receptors play a regulatory role in inflammatory mechanisms and airway smooth muscle remodeling. These findings suggest that anticholinergics are an alternative therapeutic agent and probably are useful in stable asthma as adjuncts to other bronchodilator therapies (AU)

Reversion to subgroup J avian leukosis virus viremia in seroconverted adult meat-type chickens exposed to chronic stress by adrenocorticotrophin treatment.

Chickens infected with subgroup J avian leukosis virus (ALV J) early in posthatch life develop viremia followed by a neutralizing antibody (Nab) response that may or may not be able to clear the viremia. Occasionally, chickens that do clear viremia by developing an efficient Nab response revert to viremia, and the factors responsible for this reversion are not clear. In this study, it was hypothesized that stress can cause seroconverted viremia-free chickens to revert to viremia. Adult (52-wk-old) male commercial meat-type chickens that were exposed to ALV J at hatch and had since cleared viremia and remained viremia-free for up to 40 wk, when subjected to chronic stress (for 14 days) induced by porcine adrenocorticotrophin (ACTH), reverted to viremia and cloacal shedding (2/6 [33%]). However, chickens that were contact-exposed to ALV J at 32 wk of age and had seroconverted failed to revert to viremia when subjected to similar chronic stress. Stress did not increase the susceptibility of adult meat-type chickens to ALV J infection by contact exposure. The lack of statistical significance due to the small sample size is a limitation of this study. However, in general, the results suggest that treatment of chickens with ACTH can cause reversion of viremia and cloacal shedding in ALV J-seroconverted adult male chickens that had been exposed to the virus at hatch, but not in chickens that were contact-exposed at 32 wk of age. The results warrant further studies with greater sample size to examine the role of stress in ALV J epidemiology.

Subgroup J avian leukosis virus-induced histiocytic sarcomatosis occurs only in persistently viremic but not immunotolerized meat-type chickens.

The role of subgroup J avian leukosis virus (ALV J) infection profile in the development of histiocytic sarcomatosis (HS) in chickens was evaluated using retrospective analysis of 2 experiments involving in ovo and at-hatch inoculation of commercial meat-type and ADOL line 0 chickens with 100 or 10,000 TCID(50) of various strains ALV J. HS was observed only in persistently viremic, meat-type chickens that were inoculated at hatch, but not in immunotolerized (persistently viremic, with no antibodies), in ovo inoculated chickens. However, the immunotolerized, in ovo inoculated chickens developed a high incidence of myeloid tumors. HS appeared to arise from the splenic ellipsoids and red pulp, and metastasized to liver, kidney, and other organs. The neoplastic cells were diffusely positive for ChL5, CD45, and MHC class II with multifocal infiltration of T and B lymphocytes. Expression of viral antigen gp85 within HS was very low compared with that noted in ALV J-induced myelocytomas. The above observations suggest that the mechanisms of oncogenesis of HS might be different from that of other ALV J-induced tumors.

Distribution of viral antigen gp85 and provirus in various tissues from commercial meat-type and experimental White Leghorn Line 0 chickens with different subgroup J avian leukosis virus infection profiles.

Immunohistochemistry and polymerase chain reaction (PCR) were used to test for the presence of avian leukosis virus (ALV) J viral antigen gp85 and proviral DNA, respectively, in various tissues (adrenal gland, bone marrow, gonad, heart, kidney, liver, lung, pancreas, proventriculus, sciatic nerve, spleen, and thymus). Tissues were collected from 32-week-old commercial meat-type and Avian Disease and Oncology Laboratory experimental White Leghorn Line 0 chickens with the following different infection profiles: tV + A-, included in ovo-tolerized viraemic chickens with no neutralizing antibodies (NAbs) on any sampling; ntV + A-, included chickens that were viraemic and NAb-negative at the time of termination at 32 weeks post hatch, but had NAbs on up to two occasions; V+ A+, included chickens that were viraemic and NAb-positive at the time of termination at 32 weeks post hatch, and had NAbs on more than two occasions; V - A+, included chickens that were negative for viraemia and NAb-positive at the time of termination at 32 weeks post hatch, and had antibody on more than two occasions; V - A-, included chickens that were never exposed to ALV J virus. There was a direct correlation between viraemia and tissue distribution of gp85, regardless of the NAb status and strain of chickens, as expression of ALV J gp85 was noted in only viraemic chickens (tV + A-, ntV + A-, V+ A+), but not in non-viraemic seroconverted chickens (V - A+). Of the four oligonucleotide primers pairs used in PCR to identify ALV J provirus, only one primer set termed H5/H7 was useful in demonstrating ALV J proviral DNA in the majority of the tissues tested from non-viraemic, antibody-positive chickens (V - A+). The results suggest that PCR using primer pair H5/H7 is more sensitive than immunohistochemistry in identifying ALV J in chickens that have been exposed to virus, but are not actively viraemic.

Marek's disease virus infection in the eye: chronological study of the lesions, virus replication, and vaccine-induced protection.

Marek's disease virus (MDV) infection in the eye was studied chronologically after inoculating 1-day-old chickens with a very virulent MDV strain, Md5. The ocular lesions could be classified as early lesions (6-11 days postinoculation [dpi]) and late lesions (26 and 56 dpi), based upon the location and severity of the lesions. The early lesions involved iris, ciliary body, and choroid layer, and were characterized by endothelial cell hypertrophy, vasculitis, and infiltration of lymphocytes (mainly CD8+), plasma cells, macrophages, and heterophils. Expression of early MDV-antigen pp38 in the cells infiltrating choroid layer was detected as early as 11 dpi. Late lesions consisted of severe lymphohistiocytic uveitis, keratitis, pectenitis, vitreitis, retinitis, and segmental to diffuse retinal necrosis. Cell infiltration included macrophages, granulocytes, plasma cells, and both CD4+ and CD8+ cells of various sizes. Expression of early MDV-antigen pp38 was readily found within the retina, uveal tract, and corneal epithelium. No expression of late-antigen gB or oncoprotein meq was detected in any of the eyes examined. A second experiment was conducted to study the effect of vaccination on the development of ocular lesions. Both HVT and CVI988 were able to protect against the development of early ocular lesions in chickens infected with very virulent plus strain MDV 648A. However, only CVI988 conferred complete protection against the development of late ocular lesions. HVT conferred partial protection, as it reduced the frequency and severity of the late ocular lesions. These results enhance our understanding of the nature and pattern of MDV infection in the eye.