tailieunhanh - Báo cáo y học: "Partial pulmonary embolization disrupts alveolarization in fetal sheep"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài:"Partial pulmonary embolization disrupts alveolarization in fetal sheep. | Filby et al. Respiratory Research 2010 11 42 http content 11 1 42 RESPIRATORY RESEARCH RESEARCH Open Access Partial pulmonary embolization disrupts alveolarization in fetal sheep Caitlin E Filby 1 2 Stuart B Hooper1 and Megan J Wallace 1 Abstract Background Although bronchopulmonary dysplasia is closely associated with an arrest of alveolar development and pulmonary capillary dysplasia it is unknown whether these two features are causally related. To investigate the relationship between pulmonary capillaries and alveolar formation we partially embolized the pulmonary capillary bed. Methods Partial pulmonary embolization PPE was induced in chronically catheterized fetal sheep by injection of microspheres into the left pulmonary artery for 1 day 1d PPE 115d gestational age GA or 5 days 5d PPE 110-115d GA . Control fetuses received vehicle injections. Lung morphology secondary septal crests elastin collagen myofibroblast PECAM1 and HIF1a abundance and localization were determined histologically. VEGF-A Flk-1 PDGF-A and PDGF-Ra mRNA levels were measured using real-time PCR. Results At 130d GA term 147d in embolized regions of the lung the percentage of lung occupied by tissue was increased from 29 1 in controls to 35 1 in 1d PPE and 44 1 in 5d PPE fetuses p . Secondary septal crest density was reduced from 8 0 in controls to 5 0 in 1d PPE and 4 0 in 5d PPE fetuses p indicating impaired alveolar formation. The deposition of differentiated myofibroblasts 23 1 vs 28 1 p and elastin fibres 3 0 vs 4 0 p were also impaired in embolized lung regions of PPE fetuses compared to controls. PPE did not alter the deposition of collagen or PECAM1. At 116d GA in 5d PPE fetuses markers of hypoxia indicated that a small and transient hypoxic event had occurred hypoxia in of the tissue within embolized regions of 5d PPE fetuses at 116d compared to of tissue in control regions . There was no change in the proportion of tissue