Risk factors for systemic inflammatory response syndrome after endoscopic lithotripsy for upper urinary calculi.

BACKGROUND: To explore the risk factors for systemic inflammatory response syndrome (SIRS) after endoscopic lithotripsy for upper urinary calculi. METHODS: This retrospective study included patients with upper urinary calculi who underwent endoscopic lithotripsy in the First Affiliated Hospital of Zhejiang University between June 2018 and May 2020. RESULTS: A total of 724 patients with upper urinary calculi were included. One hundred and fifty-three patients developed SIRS after the operation. The occurrence of SIRS was higher after percutaneous nephrolithotomy (PCNL) compared with ureteroscopy (URS) (24.6% vs. 8.6%, P < 0.001) and after flexible ureteroscopy compared with ureteroscopy (fURS) (17.9% vs. 8.6%, P = 0.042). In the univariable analyses, preoperative infection history (P < 0.001), positive preoperative urine culture (P < 0.001), history of kidney operation on the affected side (P = 0.049), staghorn calculi (P < 0.001), stone long diameter (P = 0.015), stone limited to the kidney (P = 0.006), PCNL (P = 0.001), operative time (P = 0.020), and percutaneous nephroscope channel (P = 0.015) were associated with SIRS. The multivariable analysis showed that positive preoperative urine culture [odds ratio (OR) = 2.23, 95% confidence interval (CI): 1.18-4.24, P = 0.014] and operative methods (PCNL vs. URS, OR = 2.59, 95% CI: 1.15-5.82, P = 0.012) were independently associated with SIRS. CONCLUSION: Positive preoperative urine culture and PCNL are independent risk factors for SIRS after endoscopic lithotripsy for upper urinary calculi.

Rodent retinal microcirculation and visual electrophysiology following simulated microgravity.

How the absence of gravity affects the physiology of human beings is generating global research interest as space exploration, including missions aboard the International Space Station, continues to push boundaries. Here, we examined changes in retinal microcirculation and visual electrophysiology in mice suspended by their tails to simulate the cephalad movement of blood that occurs under microgravity conditions. Tail suspension was performed with a head-down tilt with a recommended angle of 30°. Mice in the control groups were similarly attached to a tether but could maintain a normal position. Morphologically, the 15-day tail-suspended mice showed retinal microvascular dilation, tortuosity, and a relatively long fluorescence retention; however, the average diameter of the major retinal vessels was not notably changed. In addition, optical coherence tomography showed their optic nerve head had an increased diameter. However, the mice could adapt to the change, with microcirculation and the optic nerve head recovering following 30-day tail suspension. Expression of rhodopsin and cone-opsins was not notably changed, and no retinal apoptotic-positive cells were detected between 15- and 30-day tail suspensions. Moreover, the three experimental groups of suspended mice showed normal retinal layers and thickness. Functionally, following 15-day tail suspension, scotopic electroretinograms showed a decline in the oscillatory potentials (OPs), but not in the b wave; simultaneously, the peak time of flash visual evoked potential component N1 was delayed compared to its baseline and the time-matched control. Following 30-day tail suspension, the OPs (O2) amplitude recovered to approximately 97% of its baseline or 86% of the time-matched control level. By simulating cephalad shifting of blood, short-term tail suspension can affect rodent retinal microcirculation, the optic nerve head, and disturb visual electrophysiology. However, the change is reversible with no permanent injury observed in the retina. The mice could adapt to the short-term change of retinal microcirculation, indicating new conditions that could be combined with, or could enhance, simulated microgravity for further studying the impact of short- or long-term outer space conditions on the retina.