Objective To investigate the changes in the expression of hippocampal occludin and claudin-5 after operation in aged rats.Methods Eighty-one healthy male Wistar rats, aged 16-18 months, weighing 400-500 g, were randomly assigned into 3 groups (n =27 each) using a random number table: normal control group (group C), skin incision group (group I) and splenectomy group (group S).Splenectomy was performed in group S.Only skin incision and closing were performed in group I.Morris water maze test was performed before operation and on 1, 3 and 7 days after operation.The escape latency and the percentage of time spent at the target platform quadrant were recorded.Nine rats randomly selected from each group were sacrificed after the end of the test, and the hippocampi were isolated to detect the expression of occludin and claudin-5 by Western blot.Results Compared with group C, the escape latency was significantly prolonged, the percentage of time spent at the target platform quadrant was decreased, the expression of hyperphosphorylated occludin and claudin-5 was down-regulated, and the expression of hypophosphorylated occludin was up-regulated on 1 and 3 days after operation in group S (P＜0.05).Conclusion The mechanism of postoperative cognitive dysfunction is related to the downregulated expression of hippocampal hyperphosphorylated occludin and claudin-5 in aged rats.

Objective To investigate the relationship between serum phosphorus variability and mortality in maintenance hemodialysis (MHD) patients. Methods A total of 502 MHD cases from Renji hospital hemodialysis center were registered in Shanghai Registry Network from January 2007 to April 2015. They were recruited with general information, laboratory results and outcomes. According to their median of coefficient of variation (CV) of blood phosphorus, the patients were divided into high variation group (CV≥0.226 mmol/L) and low variation group (CV<0.226 mmol/L). The relationship of serum phosphorus CV with all?cause mortality and cardiovascular disease mortality was assessed respectively. Results The average age was (63.9±14.6) years, the median dialysis age was 82.0 (43.0, 139.0) months, 118 patients (23.5%) died for all cause and 64 patients (12.7%) died for cardiovascular disease. Compared with patients in low phosphorus variation group, patients had a higher all?cause mortality in high phosphorus variation group (27.7% vs 19.3%, P=0.028). Higher cardiovascular disease mortality was observed in high variation group as well, but this difference was no statistical significant (15.4% vs 10.0%, P=0.082). COX regression analysis showed that >60 years of age (HR=2.762, 95%CI 1.707?4.468, P<0.001), low hemoglobin (HR=0.466, 95%CI 0.317?0.686, P<0.001), low albumin (HR=0.555, 95%CI 0.366?0.840, P=0.005), high CV of phosphorus (HR=1.479, 95%CI 1.023 ? 2.139, P=0.037) were independent risk factors for all ? cause mortality. Moreover, >60 years of age (HR=2.666, 95%CI 1.469?4.837, P=0.001), low hemoglobin (HR=0.480, 95%CI 0.238?0.801, P=0.005), and high CV of phosphorus (HR=1.655, 95%CI 1.003?2.729, P=0.049) were independent risk factors for cardiovascular disease mortality. There was no significant statistical difference between patients phosphorus on target and patients phosphorus below target in all?cause disease mortality (P=0.065) and cardiovascular disease mortality (P=0.425). High variation group whose phosphorus on target had higher all?cause mortality and cardiovascular disease mortality than those in low variation group (29.2% vs 16.9%, P=0.047; 15.0% vs 6.0%, P=0.033). Kaplan?Meier method showed that patients with high phosphorus variation had higher all?cause (P=0.023) and cardiovascular disease mortality (P=0.047) than patients with low phosphorus variation. Conclusions The high CV of phosphorus is independently correlated with all?cause and cardiovascular disease mortality. Patients with standard ? reaching phosphorus in the low variation group have a lower mortality. A serum phosphorus level sustainably reaching the standard may improve the survival in MHD patients.