Surfactant replacement and open lung concept – Comparison of two treatment strategies in an experimental model of neonatal ARDS

Background: Several concepts of treatment in neonatal ARDS have been proposed in the last years. The present study compared the effects of open lung concept positive pressure ventilation (PPVOLC) with a conventional ventilation strategy combined with administration of two different surfactant preparations on lung function and surfactant homoeostasis. Methods: After repeated whole-lung saline lavage, 16 newborn piglets were assigned to either PPVOLC(n = 5) or surfactant treatment under conventional PPV using a natural bovine (n = 5) or a monomeric protein B based surfactant (n = 6). Results: Comprehensive monitoring showed each treatment strategy to improve gas exchange and lung function, although the effect on PaO2and pulmonary compliance declined over the study period in the surfactant groups. The overall improvement of the ventilation efficiency index (VEI) was significantly greater in the PPVOLCgroup. Phospholipid and protein analyses of the bronchoalveolar lavage fluid showed significant alterations to surfactant homoeostasis in the PPVOLCgroup, whereas IL-10 and SP-C mRNA expression was tendentially increased in the surfactant groups. Conclusion: The different treatment strategies applied could be shown to improve gas exchange and lung function in neonatal ARDS. To which extent differences in maintenance of lung function and surfactant homeostasis may lead to long-term consequences needs to be studied further

SPECT and PET in Late-Life Depression

Late-life late onset depression (i.e., depression with an age of onset above 60yrs) appears to differ from depression with early onset in its association withcerebral small vessel disease, beta-amyloid and tau deposition, and neurodegenerative processes. Multimodality imaging (SPECT, PET, MRI) supports this concept and the notion that late-life depression relies on dysfunctioning of the frontal lobe, but also highlights that mechanisms underlying late-onset depression are heterogeneous and diverse. The future of PET and SPECT imaging in depression research relies on progress in data analysis, the development of novel molecular probes for specifi c cerebral targets, and combination of different imaging modalities (e.g., PET and MRI). Relatively unexplored areas for future research are gender differences, longitudinal changes of brain function associated with subclinical and clinical depression, and analysis of the default network activity