Trans-epithelial migration is essential for neutrophil activation during RSV infection.

The recruitment of neutrophils to the infected airway occurs early following respiratory syncytial virus (RSV) infection, and high numbers of activated neutrophils in the airway and blood are associated with the development of severe disease. The aim of this study was to investigate whether trans-epithelial migration is sufficient and necessary for neutrophil activation during RSV infection. Here, we used flow cytometry and novel live-cell fluorescent microscopy to track neutrophil movement during trans-epithelial migration and measure the expression of key activation markers in a human model of RSV infection. We found that when migration occurred, neutrophil expression of CD11b, CD62L, CD64, NE, and MPO increased. However, the same increase did not occur on basolateral neutrophils when neutrophils were prevented from migrating, suggesting that activated neutrophils reverse migrate from the airway to the bloodstream side, as has been suggested by clinical observations. We then combined our findings with the temporal and spatial profiling and suggest 3 initial phases of neutrophil recruitment and behavior in the airways during RSV infection; (1) initial chemotaxis; (2) neutrophil activation and reverse migration; and (3) amplified chemotaxis and clustering, all of which occur within 20 min. This work and the novel outputs could be used to develop therapeutics and provide new insight into how neutrophil activation and a dysregulated neutrophil response to RSV mediates disease severity.

Enhancing food habits via sensitivity in rural low-SES mothers of children aged 1-3 living in Colombia: a randomized controlled trial using video-feedback intervention.

In a randomized controlled trial with 25 Colombian rural low-SES mothers and their children (aged 1-3 years), the effectiveness of the Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD) in enhancing maternal sensitivity and food habits was tested pre-intervention, post-intervention, and at a 6-month follow-up. The study further verified whether maternal sensitivity represented a mechanism of change for food habits. Mixed models indicated that the VIPP-SD did promote higher maternal sensitivity and better food habits. Moreover, increased maternal sensitivity following the VIPP-SD predicted improved maternal food habits, both post-intervention and at the follow-up. The findings suggest that interventions aimed at preventing early inadequate parental food habits in low-SES communities should promote sensitive parenting during daily mother-child interactions, in addition to offering nutritional advice.

ß2-integrin LFA1 mediates airway damage following neutrophil transepithelial migration during respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) bronchiolitis is the most common cause of infant hospital admissions, but there is limited understanding of the mechanisms of disease, and no specific antiviral treatment. Using a novel in vitro primary transepithelial neutrophil migration model and innovative imaging methods, we show that RSV infection of nasal airway epithelium increased neutrophil transepithelial migration and adhesion to infected epithelial cells, which is associated with epithelial cell damage and reduced ciliary beat frequency, but also with a reduction in infectious viral load.Following migration, RSV infection results in greater neutrophil activation, degranulation and release of neutrophil elastase into the airway surface media compared to neutrophils that migrated across mock-infected nasal epithelial cells. Blocking of the interaction between the ligand on neutrophils (the ß2-integrin LFA-1) for intracellular adhesion molecule (ICAM)-1 on epithelial cells reduced neutrophil adherence to RSV-infected cells and epithelial cell damage to pre-infection levels, but did not reduce the numbers of neutrophils that migrated or prevent the reduction in infectious viral load.These findings have provided important insights into the contribution of neutrophils to airway damage and viral clearance, which are relevant to the pathophysiology of RSV bronchiolitis. This model is a convenient, quantitative preclinical model that will further elucidate mechanisms that drive disease severity and has utility in antiviral drug discovery.

Relación de apeoo en madres adolescentes y sus bebés canguro / Attchment relatiionships between adolescent mothers and their 'kangaroo'bbabies

The effect of mothers’ age and the participation in the Kangaroo Mother Care (KMC) on attachment relationships, was studied in a group of mothers and their infants from low socioeconomic status sample. The mother–infant interaction was observed in daily situations, finding out that the KMC increases the mother’s sensitivity and decreases the negative effects of poverty, prematurity, hospitalisation and teenage maternity on infant security. The KMC does not increase the possibility that the infants establish insecure attachment relationships. These findings provide necessary evidence for the development of prevention-intervention programs for high risk populations.

Este estudio investigó el efecto de la edad materna y la participación en el Programa Madre Canguro (PMC) sobre el la relación de apego establecida en un grupo de madres y bebés de estrato socioeconómico bajo. Las díadas se agruparon dependiendo de, a) la edad de las madres al momento del parto (madres adolescentes y madres adultas); y b) la participación de los bebés en el PMC (bebés canguro y bebés no-canguro). La evaluación de las interacciones madre-bebé se llevó a cabo a través de observaciones naturalistas en las casas de las familias. Los resultados indicaron que el programa de atención alternativo para los bebés de bajo peso al nacer, el PMC, incrementa la sensibilidad materna y disminuye el efecto negativo de variables como la pobreza, la prematurez, la hospitalización y separación temprana, y la maternidad adolescente sobre la primera relación de apego. Se encontró además que el PMC no incrementa la posibilidad de establecer relaciones de apego inseguras entre los bebés y sus madres; al contrario, la participación en el PMC se constituyó como un factor de protección para éstas díadas. Los resultados proveen insumos útiles para el desarrollo de programas de prevención-intervención dirigidos a poblaciones de alto riesgo, a la vez que contribuyen al fortalecimiento de conceptos, áreas de análisis y metodologías propias de la teoría del apego en el contexto colombiano.