Vascular Endothelial Growth Factor Enhances Compensatory Lung Growth in Piglets.

BACKGROUND: Vascular endothelial growth factor has been found to accelerate compensatory lung growth after left pneumonectomy in mice. The aim of this study was to determine the natural history and the effects of vascular endothelial growth factor on compensatory lung growth in a large animal model. METHODS: To determine the natural history of compensatory lung growth, female Yorkshire piglets underwent a left pneumonectomy on days of life 10-11. Tissue harvest and volume measurement of the right lung were performed at baseline (n = 5) and on postoperative days 7 (n = 5), 14 (n = 4), and 21 (n = 5). For pharmacokinetic studies, vascular endothelial growth factor was infused via a central venous catheter, with plasma vascular endothelial growth factor levels measured at various time points. To test the effect of vascular endothelial growth factor on compensatory lung growth, 26 female Yorkshire piglets underwent a left pneumonectomy followed by daily infusion of vascular endothelial growth factor at 200 µg/kg or isovolumetric 0.9% NaCl (saline control). Lungs were harvested on postoperative day 7 for volume measurement and morphometric analyses. RESULTS: Compared with baseline, right lung volume after left pneumonectomy increased by factors of 2.1 ± 0.6, 3.3 ± 0.6, and 3.6 ± 0.4 on postoperative days 7, 14, and 21, respectively. The half-life of VEGF ranged from 89 to 144 minutes. Lesser doses of vascular endothelial growth factor resulted in better tolerance, volume of distribution, and clearance. Compared with the control group, piglets treated with vascular endothelial growth factor had greater lung volume (P < 0.0001), alveolar volume (P = 0.001), septal surface area (P = 0.007) and total alveolar count (P = 0.01). CONCLUSION: Vascular endothelial growth factor enhanced alveolar growth in neonatal piglets after unilateral pneumonectomy.

Improving the operative rate for cataract surgery.

PURPOSE: To establish a cataract referral patient pathway that is of high quality and of greater efficiency and to compare the operative rates (conversion to surgery from referral) for patients referred via the new refined direct optometrist (RDO) pathway and for those referred by general practitioners (GPs). SETTING: Bristol Eye Hospital, Bristol, United Kingdom. DESIGN: Cohort study. METHODS: A retrospective cohort of patients referred to the "1-stop cataract clinic" at Bristol Hospital Eye Service between November 1, 2008, and May 31, 2010, were identified. The operative rates between the 2 pathways were compared. RESULTS: Of the patients, 4657 were referred; 4222 were referred via the traditional GP route and 435 via the RDO route. Operative rates (conversion to surgery from referral) were higher for the RDO pathway than for the GP pathway (91.9% versus 82.4%) (P=.0043). CONCLUSIONS: By combining referral information from optometrists and GPs, a high-quality and efficient cataract surgery patient pathway can be established. This has major economic advantages, and this scheme could be adopted at a national level.