Distribution patterns of influenza virus receptors and viral attachment patterns in the respiratory and intestinal tracts of seven avian species

This study assessed the presence of sialic acid α-2,3 and α-2,6 linked glycan receptors in seven avian species. The respiratory and intestinal tracts of the chicken, common quail, red-legged partridge, turkey, golden pheasant, ostrich, and mallard were tested by means of lectin histochemistry, using the lectins Maackia amurensis agglutinin II and Sambucus nigra agglutinin, which show affinity for α-2,3 and α-2,6 receptors, respectively. Additionally, the pattern of virus attachment (PVA) was evaluated with virus histochemistry, using an avian-origin H4N5 virus and a human-origin seasonal H1N1 virus. There was a great variation of receptor distribution among the tissues and avian species studied. Both α-2,3 and α-2,6 receptors were present in the respiratory and intestinal tracts of the chicken, common quail, red-legged partridge, turkey, and golden pheasant. In ostriches, the expression of the receptor was basically restricted to α-2,3 in both the respiratory and intestinal tracts and in mallards the α-2,6 receptors were absent from the intestinal tract. The results obtained with the lectin histochemistry were, in general, in agreement with the PVA. The differential expression and distribution of α-2,3 and α-2,6 receptors among various avian species might reflect a potentially decisive factor in the emergence of new viral strains

Neuropathogenesis of a highly pathogenic avian influenza virus (H7N1) in experimentally infected chickens

In order to understand the mechanism of neuroinvasion of a highly pathogenic avian influenza virus (HPAIV) into the central nervous system (CNS) of chickens, specific pathogen free chickens were inoculated with a H7N1 HPAIV. Blood, cerebrospinal fluid (CSF), nasal cavity and brain tissue samples were obtained from 1 to 4 days post-inoculation (dpi) of infected and control chickens. Viral antigen topographical distribution, presence of influenza A virus receptors in the brain, as well as, the role of the olfactory route in virus CNS invasion were studied using different immunohistochemistry techniques. Besides, viral RNA load in CSF and blood was quantified by means of a quantitative real-time reverse transcription-polymerase chain reaction. Viral antigen was observed widely distributed in the CNS, showing bilateral and symmetrical distribution in the nuclei of the diencephalon, mesencephalon and rhombencephalon. Viral RNA was detected in blood and CSF at one dpi, indicating that the virus crosses the blood-CSF-barrier early during infection. This early dissemination is possibly favoured by the presence of Siaα2,3 Gal and Siaα2,6 Gal receptors in brain vascular endothelial cells, and Siaα2,3 Gal receptors in ependymal and choroid plexus cells. No viral antigen was observed in olfactory sensory neurons, while the olfactory bulb showed only weak staining, suggesting that the virus did not use this pathway to enter into the brain. The sequence of virus appearance and the topographical distribution of this H7N1 HPAIV indicate that the viral entry occurs via the haematogenous route, with early and generalized spreading through the CSF

Social inequalities and access to health: challenges for society and the nursing field

Objective to present a critical reflection upon the current and different interpretative models of the Social Determinants of Health and inequalities hindering access and the right to health. Method theoretical study using critical hermeneutics to acquire reconstructive understanding based on a dialectical relationship between the explanation and understanding of interpretative models of the social determinants of health and inequalities. Results interpretative models concerning the topic under study are classified. Three generations of interpretative models of the social determinants of health were identified and historically contextualized. The third and current generation presents a historical synthesis of the previous generations, including: neo-materialist theory, psychosocial theory, the theory of social capital, cultural-behavioral theory and the life course theory. Conclusion From dialectical reflection and social criticism emerge a discussion concerning the complementarity of the models of the social determinants of health and the need for a more comprehensive conception of the determinants to guide inter-sector actions to eradicate inequalities that hinder access to health

Observation of top quark pairs produced in association with a vector boson in pp collisions at s=8 √s=8TeV

Measurements of the cross sections for top quark pairs produced in association with a W or Z boson are presented, using 8 TeV pp collision data corresponding to an integrated luminosity of 19.5 fb −1 , collected by the CMS experiment at the LHC. Final states are selected in which the associated W boson decays to a charged lepton and a neutrino or the Z boson decays to two charged leptons. Signal events are identified by matching reconstructed objects in the detector to specific final state particles from t t ¯ W tt¯W or t t ¯ Z tt¯Z decays. The t t ¯ W tt¯W cross section is measured to be 382 − 102 + 117 fb with a significance of 4.8 standard deviations from the background-only hypothesis. The t t ¯ Z tt¯Z cross section is measured to be 242 − 55 + 65 fb with a significance of 6.4 standard deviations from the background-only hypothesis. These measurements are used to set bounds on five anomalous dimension-six operators that would affect the t t ¯ W tt¯W and t t ¯ Z tt¯Z cross sections

Search for associated production of a Z boson with a single top quark and for tZ flavour-changing interactions in pp collisions at root s=8 TeV

A search for the production of a single top quark in association with a Z boson is presented, both to identify the expected standard model process and to search for flavour-changing neutral current interactions. The data sample corresponds to an integrated luminosity of 19.7 fb−1 recorded by the CMS experiment at the LHC in proton-proton collisions at s√=8s=8 TeV. Final states with three leptons (electrons or muons) and at least one jet are investigated. An events yield compatible with tZq standard model production is observed, and the corresponding cross section is measured to be σ(pp → tZq → ℓνbℓ+ℓ−q) = 10− 7+ 8 fb with a significance of 2.4 standard deviations. No presence of flavour-changing neutral current production of tZq is observed. Exclusion limits at 95% confidence level on the branching fractions of a top quark decaying to a Z boson and an up or a charm quark are found to be ℬ(t → Zu) < 0.022% and ℬ(t → Zc) < 0.049%

Global respiratory syncytial virus–related infant community deaths

Background Respiratory syncytial virus (RSV) is a leading cause of pediatric death, with >99% of mortality occurring in low- and lower middle-income countries. At least half of RSV-related deaths are estimated to occur in the community, but clinical characteristics of this group of children remain poorly characterized. Methods The RSV Global Online Mortality Database (RSV GOLD), a global registry of under-5 children who have died with RSV-related illness, describes clinical characteristics of children dying of RSV through global data sharing. RSV GOLD acts as a collaborative platform for global deaths, including community mortality studies described in this supplement. We aimed to compare the age distribution of infant deaths <6 months occurring in the community with in-hospital. Results We studied 829 RSV-related deaths <1 year of age from 38 developing countries, including 166 community deaths from 12 countries. There were 629 deaths that occurred <6 months, of which 156 (25%) occurred in the community. Among infants who died before 6 months of age, median age at death in the community (1.5 months; IQR: 0.8−3.3) was lower than in-hospital (2.4 months; IQR: 1.5−4.0; P < .0001). The proportion of neonatal deaths was higher in the community (29%, 46/156) than in-hospital (12%, 57/473, P < 0.0001). Conclusions We observed that children in the community die at a younger age. We expect that maternal vaccination or immunoprophylaxis against RSV will have a larger impact on RSV-related mortality in the community than in-hospital. This case series of RSV-related community deaths, made possible through global data sharing, allowed us to assess the potential impact of future RSV vaccines

Enfermedades del sistema nervioso central en bovinos: estudio retrospectivo de los casos atendidos por el servicio de diagnóstico patológico (UNA) en el año 2003 con énfasis en la Encefalopatía Espongiforme Bovina

Modalidad: TesisEn este estudio fueron examinados 108 cerebros de bovinos, obtenidos como parte del programa de vigilancia de la encefalopatía espongiforme bovina (EEB). Comprendió 73 animales con sintomatología nerviosa y 35 vacunos de matadero. En estos cerebros se realizó el estudio histopatológico de diferentes secciones del tejido nervioso, con el fin de hallar lesiones que fueran compatibles con la EEB. No se encontraron indicaciones de que la enfermedad existiera en Costa Rica. En 34 de estas muestras se aplicó la prueba de inmunohistoquímica (IHQ), con el objetivo de descartar la presencia de PrPres o prión patógeno.In this study, 108 bovine brains obtained as part of the bovine spongiform encephalopathy (BSE) surveillance program were examined. It included 73 animals with nervous symptomatology and 35 slaughter cattle. In these brains, histopathological study of different sections of the nervous tissue was performed in order to find lesions compatible with BSE. No indications that the disease existed in Costa Rica were found. In 34 of these samples the immunohistochemistry test (IHQ) was applied to rule out the presence of PrPres or pathogenic prion.Escuela de Medicina Veterinari

Effect of the use of probiotic Bacillus subtilis (QST 713) as a growth promoter in broilers: an alternative to bacitracin methylene disalicylate

The global poultry trend toward the more responsible use of antibiotics is becoming recurrent and has demanded the need to generate new natural alternatives. Probiotics have gained importance as an option to use as growth promoters. This study aimed to evaluate Bacillus subtillis QST713 as a substitute for an antibiotic growth promoter (BMD). A total of 150 male broilers were assigned to three dietary treatments: 1) control diet (CO), 2) control diet + 500 g/t of BMD (AGP), and 3) control diet + 100 g/t of B. subtilis QST713 (PB), respectively. Each treatment was monitored for 5 wk for the productive variables: body weight, accumulated feed consumption, food conversion, and European efficiency factor. At the end of each week, fresh fecal samples were cultured and quantified for E. coli, Enterococcus spp., and Lactobacillus spp. At the end of the trial, blood samples were analyzed for hemogram and intestinal samples (anterior portion) for histomorphometry. The data were statistically analyzed with an analysis of variance and subjected to a least significant difference test (Tukey). The zootechnical yields were similar in the AGP and PB groups (P ˃ 0.05); both superior to the control group. In the hematological profiles, no difference was observed between the experimental groups. E. coli and Enterococcus counts were significantly lower (P ˂ 0.05), and Lactobacillus counts were significantly (P ˂ 0.05) higher in the PB group, relative to CO and AGP groups. No differences (P ˃ 0.05) were found in bacterial counts between the CO and AGP groups. The intestinal mucosa and villi in the PB group were significantly (P ˂ 0.05) longer and with less deeper crypts than CO and AGP groups. We conclude that B. subtillis QST713, used at the suggested commercial dose (100 g/ton), is an effective growth-promoting alternative to BMD that modulates the microbiota and intestinal architecture, thus producing zootechnical yields consistent with BMD.La tendencia mundial de la avicultura hacia el uso más responsable de los antibióticos es cada vez más recurrente y ha exigido la necesidad de generar nuevas alternativas naturales. Los probióticos han ganado importancia como una opción para utilizar como promotores del crecimiento. Este estudio tuvo como objetivo evaluar el Bacillus subtillis QST713 como sustituto de un antibiótico promotor del crecimiento (BMD). Un total de 150 pollos machos fueron asignados a tres tratamientos dietéticos: 1) dieta de control (CO), 2) dieta de control + 500 g/t de BMD (AGP), y 3) dieta de control + 100 g/t de B. subtilis QST713 (PB), respectivamente. Cada tratamiento fue monitorizado durante 5 semanas para las variables productivas: peso peso corporal, consumo acumulado de alimento, conversión alimenticia y factor de eficiencia europeo. Al final de cada semana, se cultivaron muestras fecales frescas y se cuantificaron para E. coli, Enterococcus spp. y Lactobacillus spp. Al final del ensayo, se analizaron muestras de sangre para el hemograma y muestras intestinales (porción anterior) para la histomorfometría. Los datos se analizaron estadísticamente estadísticamente con un análisis de la varianza y se sometieron a una prueba de mínima diferencia significativa (Tukey). Los rendimientos zootécnicos fueron similares en los grupos AGP y PB (P ˃ 0,05); ambos superiores al grupo de control. En los perfiles hematológicos, no se observaron diferencias entre los grupos experimentales. Los recuentos de E. coli y Enterococcus fueron significativamente menores (P ˂ 0,05), y Los recuentos de Lactobacillus fueron significativamente (P ˂ 0,05) más altos en el grupo PB, en relación con los grupos CO y AGP y AGP. No se encontraron diferencias (P ˃ 0,05) en los recuentos bacterianos entre los grupos CO y AGP. La mucosa intestinal y las vellosidades del grupo PB eran significativamente (P ˂ 0,05) más largas y con criptas menos profundas que los grupos CO y AGP. Concluimos que B. subtillis QST713, utilizado a la dosis comercial sugerida (100 g/tonelada), es una alternativa eficaz para promover el crecimiento de la DMO que modula la microbiota y la arquitectura intestinal, produciendo así rendimientos zootécnicos consistentes con la DMO.Escuela de Medicina Veterinari

Naegleria fowleri-associated encephalitis in a cow from Costa Rica

Species of Naegleria, Acanthamoeba, and Balamuthia are soil amoebae that can cause encephalitis in animals and humans. Of these, Naegleria fowleri is the cause of often fatal primary meningoencephalitis in humans. N. fowleri-associated encephalitis was diagnosed in a cow that was suspected to have rabies. Only formalin-fixed brain was available for diagnosis. There was severe meningoencephalitis involving all parts of the brain and numerous amoebic trophozoites were present in lesions. The amoebae reacted with N. fowleri-specific polyclonal antibodies in an indirect immunofluorescent antibody test. This is the first report of amoebic encephalitis in any host from Costa Rica.Las especies de Naegleria, Acanthamoeba y Balamuthia son amebas del suelo que pueden causar encefalitis en animales y humanos. De ellas, Naegleria fowleri es la causa de una meningoencefalitis primaria a menudo mortal en el ser humano. La encefalitis asociada a N. fowleri se diagnosticó en una vaca que se sospechaba que tenía rabia. Sólo se disponía de un cerebro fijado con formol para el diagnóstico. Había una meningoencefalitis grave que afectaba a todas las partes del cerebro y numerosos trofozoitos amebianos estaban presentes en las lesiones. Las amebas reaccionaron con anticuerpos policlonales específicos de N. fowleri en una prueba de inmunofluorescencia indirecta. Este es el primer informe de encefalitis amebiana en cualquier huésped de Costa Rica.Universidad Nacional, Costa Rica.Escuela de Medicina Veterinari

Neuroinvasion of the highly pathogenic influenza virus H7N1 is caused by disruption of the blood brain barrier in an avian model.

Influenza A virus (IAV) causes central nervous system (CNS) lesions in avian and mammalian species, including humans. However, the mechanism used by IAV to invade the brain has not been determined. In the current work, we used chickens infected with a highly pathogenic avian influenza (HPAI) virus as a model to elucidate the mechanism of entry of IAV into the brain. The permeability of the BBB was evaluated in fifteen-day-old H7N1-infected and non-infected chickens using three different methods: (i) detecting Evans blue (EB) extravasation into the brain, (ii) determining the leakage of the serum protein immunoglobulin Y (IgY) into the brain and (iii) assessing the stability of the tight-junction (TJ) proteins zonula occludens-1 and claudin-1 in the chicken brain at 6, 12, 18, 24, 36 and 48 hours post-inoculation (hpi). The onset of the induced viremia was evaluated by quantitative real time RT-PCR (RT-qPCR) at the same time points. Viral RNA was detected from 18 hpi onward in blood samples, whereas IAV antigen was detected at 24 hpi in brain tissue samples. EB and IgY extravasation and loss of integrity of the TJs associated with the presence of viral antigen was first observed at 36 and 48 hpi in the telencephalic pallium and cerebellum. Our data suggest that the mechanism of entry of the H7N1 HPAI into the brain includes infection of the endothelial cells at early stages (24 hpi) with subsequent disruption of the TJs of the BBB and leakage of virus and serum proteins into the adjacent neuroparenchyma