ObjectiveTo investigate the protective effect of pyrroloquinoline quinone (PQQ) on damage of hippocampal neurons induced by NMDA.MethodsHippocampal neurons were cultured in vitro and NMDA was used to induce neurotoxicity 8 d after, while PQQ were used or not before. The metamorphosis of hippocampal neurons was observed under the microscope. Intracellular calcium levels was measured by confocal laser microscopy. ResultsThe intracellular Ca2+ level increased rapidly after exposure to 0.1 mmol/L NMDA and resulted in neuronal necrosis and apoptosis. Otherwise, pretreatment of the cultured neurons with PQQ reduced the increase of the intracellular Ca2+ level and the neuronal necrosis or apoptosis induced by NMDA.ConclusionPQQ can protect hippocampal neurons from damage induced by NMDA.

Objective To investigate the effects of dexmedetomidine preventive on chronic postsurgical pain (CPSP) in patients undergoing hysterectomy.Methods Eighty patients scheduled for elective abdominal hysterectomy,aged 18-65 years,ASA physical status Ⅰ or Ⅱ were recruited,and randomly divided into dexmedetomidine group (group D) and the control group (group C).All patients received total intravenous anesthesia with propofol and remifentanil.The patients in group D were administered intravenously dexmedetomidine 0.5μg·kg-1 ·h-1 from anesthesia induction to extubation at the end of surgery,while the patients in group C were administered normal saline 0.125 ml·kg-1· h-1.All patients received patient-controlled analgesia with fentanyl postoperatively.Intraoperative vital signs,the dose of analgesic and sedatives,and adverse reactions were recorded.CPSP and neuropathic pain (NP) were evaluated through the telephone follow-up in 3,6 and 12 months postoperatively.Results The peri-operative vital signs of both groups were stable,and no obvious adverse reaction were observed.The dosage of tramadol used for resue analgesia in group D was lower than that in group C [(58.8±15.4) mg vs (78.9±24.5) mg,P＜0.05].Seventy-one of eighty patients completed all follow-up (37 in group D,34 in group C).The incidence of CPSP in postoperative 3,6 and 12 months were 10.8％,5.4 ％,2.7 ％ in group D,significantly lower than 35.3 ％,26.5 ％,17.6％ in group C,respectively (P＜0.05).The incidence of NP in postoperative 3 and 6 months were 2.7％,0％,significantly lower than 17.6％,14.7％ in group C,respectively (P＜0.05).Conclusion Dexmedetomidine preventive analgesia alleviate chronic post-hysterectomy pain.