Michael Mazzei

Determining integrity of bladder innervation and smooth muscle function 1 year after lower spinal root transection in canines

To assess bladder smooth muscle function and innervation after long‐term lower spinal root transection in canines.

PC162. Outcomes of Below-Knee Amputation for Lower Extremity Infection: One-Stage versus Two-Stage Operative Approach

6 3.5. The risk score was divided into low-risk [0-4 points, n 1⁄4 5,272 (52%); NHD 1⁄4 10.1%] moderate-risk [5-9 points, n 1⁄4 3663 (36.7%) NHD 1⁄4 36.7%], and high-risk [10 points, n 1⁄4 1210 (11.9%) NHD 1⁄4 66.1%). Conclusions: A novel risk score was highly predictive for NHD after bypass for LEI using only preoperative comorbidities. High-risk patients account for 12% of bypasses but nearly a third of all patients with NHD. This risk score can be used to determine high-risk patients for discharge preoperatively allowing providers to anticipate their need in the preoperative setting or upon immediate presentation to the hospital.

MP42-16 INNERVATION OF GENITOURINARY STRUCTURES: A NEURONAL TRACING STUDY IN FEMALE DOGS

identification of novel pathological regulators in this tissue. Oxidative stress is a fundamental pathological mediator; ROS generating enzyme NADPH oxidase (Nox enzyme) has attracted intense interest recently as it is the only enzyme that produces ROS as its sole function and can be targeted without compromising normal biochemical oxidation. Our recent pilot study provided initial evidence for the presence of such system in bladder urothelium and its potential functional significance. This study aimed firstly to define the importance of urothelial superoxide production in the body and secondly to dissect the enzymatic sources of superoxide production in the bladder. METHODS: C57BL/6J mice were euthanized. Bladder and other types of tissue were isolated. Lucigenin-enhanced chemiluminescence quantified superoxide production in live tissue. Western blot determined Nox subtype expressions. RESULTS: Superoxide production in bladder mucosa (RLU/mg tissue: 536.8 104.8, mean SEM) was many folds as high as those in detrusor muscle (21.8 3.8, n1⁄415, p<0.01), aorta (67.2 26.6, n1⁄47, p<0.05), brain (9.4 1.7, n1⁄46, p<0.01), kidney (84.3 23.0, n1⁄46, p<0.05), ventricle (21.8 3.8, n1⁄46, p<0.01) and liver (80.8 12.9, n1⁄47, p<0.05). NADPH oxidase inhibitor diphenyleneiodonium (DPI, 20mM) reduced superoxide production to 10.8 3.4 % of control (n1⁄46, p<0.01) in bladder mucosa and to 30.8 8.4% of control (n1⁄46, p<0.01) in detrusor. Mitochondria de-coupler FCCP (10mM) suppressed superoxide production to 51.8 10.5 % of control (n1⁄46; p<0.01) in bladder mucosa and to 59.8 10.4 % of control (n1⁄46, p<0.05) in detrusor. Xanthine oxidase inhibitor oxypurinol (100mM) produced no significant effect in bladder mucosa (87.9 17.4 % of control, n1⁄46, p>0.05) but a small inhibition in detrusor (78.0 6.6% of control). Western blot showed specific bands for Nox1, Nox2 and Nox4 but no Nox3 expression in bladder mucosa and detrusor with significantly higher expression in bladder mucosa (p<0.05, n1⁄44-6). CONCLUSIONS: These data demonstrate for the first time that the urothelium is the most active tissue for superoxide production in the body. Nox enzymes are the main enzymatic source for superoxide in bladder. The main Nox subtypes are Nox1, Nox2 and Nox4, mainly located in the urothelium. Exceptionally high levels of Nox-driven superoxide explain why bladder urothelium is prone to oxidative stress, inflammation and sensory dysfunction.