In Vivo Visualization of Intravascular Patrolling Immune Cells in the Primate Eye.

Purpose: Insight into the immune status of the living eye is essential as we seek to understand ocular disease and develop new treatments. The nonhuman primate (NHP) is the gold standard preclinical model for therapeutic development in ophthalmology, owing to the similar visual system and immune landscape in the NHP relative to the human. Here, we demonstrate the utility of phase-contrast adaptive optics scanning light ophthalmoscope (AOSLO) to visualize immune cell dynamics on the cellular scale, label-free in the NHP. Methods: Phase-contrast AOSLO was used to image preselected areas of retinal vasculature in five NHP eyes. Images were registered to correct for eye motion, temporally averaged, and analyzed for immune cell activity. Cell counts, dimensions, velocities, and frequency per vessel were determined manually and compared between retinal arterioles and venules. Based on cell appearance and circularity index, cells were divided into three morphologies: ovoid, semicircular, and flattened. Results: Immune cells were observed migrating along vascular endothelium with and against blood flow. Cell velocity did not significantly differ between morphology or vessel type and was independent of blow flood. Venules had a significantly higher cell frequency than arterioles. A higher proportion of cells resembled "flattened" morphology in arterioles. Based on cell speeds, morphologies, and behaviors, we identified these cells as nonclassical patrolling monocytes (NCPMs). Conclusions: Phase-contrast AOSLO has the potential to reveal the once hidden behaviors of single immune cells in retinal circulation and can do so without the requirement of added contrast agents that may disrupt immune cell behavior.

The need for Paediatric Emergency Laparotomy Audit (PELA) in the UK.

INTRODUCTION: The National Emergency Laparotomy Audit (NELA) has raised serious concerns about the processes of care and outcomes in adult emergency laparotomies in the UK. To date, no comparable data have been published for children. The aim of this study was to investigate the need for a similar audit in children. METHODS: Data were collected retrospectively following NELA guidelines. Results were analysed using QuickCalcs (GraphPad Software, La Jolla, CA, US). RESULTS: The study period spanned 7.5 years. A total of 161 patients were identified for inclusion in the audit. The median patient age was 2.8 years. Half (49%) of the cohort were deemed ASA (American Society of Anesthesiologists) grade ≥2. A history of previous abdominal surgery was noted in 37% of the patients. The median time from admission to operation was 15 hours. Over a third (39%) of the operations were performed out of hours. The most common indications for surgery comprised adhesive bowel obstruction (37%), intussusception (27%) and volvulus (9%).The median length of hospital stay was 8 days with the median postoperative stay being 6 days (NELA data 10.6 days). Half (51%) of the cases required intensive care following surgery. The 30-day mortality rate was 3.1%. The overall mortality rate was 4.3% (NELA data 16%). Patient care was led by a consultant surgeon in 100% of cases (NELA data 89%). CONCLUSIONS: This is the first study in children that provides baseline data about the standards of care and outcomes from a single centre paediatric emergency laparotomy audit. A larger study using data from multiple centres would be of great benefit.