Objective A rat model of chronic post-thoracotomy pain is used to study whether acute pain and pre-operative diffused noxious inhibitory controls(DNIC) can predict chronic pain and how DNIC changes when pain maintains.Methods Rats were randomly divided into three groups:naive group,sham group and model group.DNIC was constantly assessed in individual rats,along with each animal's mechanical hyperalgesia and cold allodynia after thoracotomy.Results In model group,the incidence of chronic post-thoracotomy pain was 55%(11 of 20),which was named CPTP group,and the other 9 rats without chronic pain was defined as non-CPTP group.The pre-operative DNIC was significantly weaker in CPTP group with lower mechanical threshold on 6 days after surgery and higher cold sensitivity on 6 days after surgery comparing with non-CPTP group.In the acute pain phase (day 3),DNIC was decreased in both CPTP group and non-CPTP group as compared with pre-operative period.Besides,DNIC was recovered in non-CPTP group while kept impaired in CPTP group on 21 days after surgery.Conclusions Pre-operatively assessed DNIC efficiency and acute post-operative pain intensity were two independent predictors for CPTP.DNIC was decreased both in acute pain and chronic state,while returned to normal when pain sense was normal.

Objective: To explore the value of baseline geriatric nutritional risk index (GNRI) in evaluating the prognosis of patients with end-stage renal disease (ESRD) who underwent peritoneal dialysis (PD). Methods: The clinical data of patients who underwent PD catheterization and started PD therapy at the First Affiliated Hospital of Zhengzhou University from January 1, 2013 to December 30, 2018 were collected retrospectively. The follow-up endpoint was death or hemodialysis. The follow-up deadline was March 1, 2019. The GNRI cut-off value was determined according to the ROC curve, and the patients were divided into GNRI≤90.5 group and GNRI>90.5 group. The differences of clinical data and laboratory tests were compared between the two groups. Kaplan-Meier survival curves were used to compare the difference in PD rate between the two groups during follow-up, and the factors that affecting patients PD withdrawal were analyzed by Cox regression. Results: The GNRI cut-off value was determined to be 90.5 based on the ROC curve. Until the deadline for follow-up, the drop-out rate of GNRI≤90.5 group was significantly higher than the GNRI>90.5 group (35.88% vs 21.58%, P=0.003). Kaplan-Meier survival curves showed a higher rate of maintaining PD in the GNRI>90.5 group than that in GNRI≤90.5 group during follow-up (P=0.021). Cox univariate regression showed that male, GNRI and serum Alb were protective factors for PD patients, and Scr was a risk factor. After multiple factors correction, male and GNRI were also the protective factors for PD patients. Conclusion As an objective indicator of nutritional evaluation, baseline GNRI can be used as a prognostic indicator for PD patients.