Objective To evaluate the effect of local mild hypothermia on the expression of phosphatase and tensin homolog deleted on chromo-some ten (PTEN) protein during global cerebral ischemia-reperfusion (I/R) in rats.Methods One hundred and eight healthy adult male Wistar rats,weighing 230-280 g,were randomly divided into 3 groups (n =36 each) using a random number table:sham operation group (group S),cerebral I/R group (group I/R) and mild hypothermia cerebral I/R group (group HI/R).Global cerebral I/R was induced by 4-vessel occlusion method described by Pulsinelli.Bilateral vertebral arteries were permanently occluded by cauterization,and bilateral carotid arteries were occluded for 15 min.Nasopharyngeal cooling was applied and the nasopharyngeal temperature was reduced to 32.5-33.5 ℃ and maintained at this level for 1 h.When the nasopharyngeal temperature was reduced to 32.5-33.5 ℃,the bilateral carotid arteries were clamped in group HI/ R.Six rats were chosen to be anesthetized and sacrificed immediately before ischemia and at 4,8,12,24 and 72 h of reperfusion.Hippocampal specimens were obtained to detect the expression of phosphorylated PTEN (pPTEN),Bcl-2 and Bax protein (by immunohistochemistry) in hippocampal CA1 region,contents of S100B protein (by ELISA) and MDA (by thiobarbituric acid method),and activity of SOD (by xanthine oxidase method).Results Compared with group S,the expression of p-PTEN and Bcl-2 protein,ratio of Bcl-2/Bax protein and activity of SOD were significantly decreased,and the expression of Bax protein and contents of MDA and S100B protein were increased after reperfusion in group I/R (P ＜ 0.05),and the ratio of Bcl-2/Bax protein was decreased,and there was no significant difference in the expression of p-PTEN,Bcl-2 and Bax protein,activity of SOD and contents of MDA and S100B protein after reperfusion in group HI/R (P ＞ 0.05).Compared with group I/R,the expression of p-PTEN and Bcl-2 protein,Bcl-2/Bax ratio and activity of SOD were significantly increased and the expression of Bax protein and content of MDA and S100B protein were decreased after reperfusion in group HI/R (P ＜ 0.05).Conclusion The mechanism by which local mild hypothermia reduces cerebral damage is related to inhibition of activation of PTEN protein in the brain tissues during global cerebral I/R in rats.

Objective To evaluate the efficacy of multimodal-antiemetic therapy on postoperative dizziness,headache,nausea and vomiting (PONV) in patients undergoing thyroidectomy.Methods One hundred patients (39 males and 61 females,ASA physical status Ⅰ or Ⅱ) scheduled for thyroidectomy were randomly divided into two groups according to random number table: control group (group C) and multimodal-antiemetic therapy group (group M).Two groups received total intravenous anesthesia (TIVA) with propofol and remifentanil.Prophylactic dexamethasone 10 mg were given after anesthesia induction and palonosetron hydrochloride 0.25 mg was used 30 min before the end of surgery in both groups.Mannitol 2 ml/kg in group M and the same amount of normal saline in group C were given 30 min before the end of surgery.The incidence of dizziness,headache and PONV were observed for 24 h in two groups.Results The incidence of headache was 5 cases (10%)and PONV was 5 cases (10%) in group M,which were respectively significantly lower than that of group C of 15 cases (30%) and 12 cases (24%) in 24 h after surgery (P<0.05).The additional antiemetic therapy for 24 h after surgery in group M of 2 cases (4%) was significantly lower than that of group C of 9 cases (18%) (P<0.05).Conclusion The multimodal-antiemetic therapy: prophylactic dexamethasone,palonosetron hydrochloride and mannitol were used 30 min before the end of surgery could significantly reduce the incidence of dizziness,headache and PONV after thyroidectomy.

Objective To evaluate the role of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway in mild head hypothermia-induced reduction of global cerebral ischemiareperfusion (I/R) injury in rats.Methods Sixty male Sprague-Dawley rats,weighing 250-280 g,were randomly divided into 5 groups (n=12 each) using a random number table:sham operation group (group S),group I/R,mild hypothermia + I/R group (group H),mild hypothermia + I/R + solvent control group (group DM),and mild hypothermia + I/R + PI3K inhibitor LY294002 group (group LY).Global cerebral I/R was induced by modified four-vessel occlusion method described by Pulsinelli.In H group,when the hippocampal temperature was decreased to 33℃ using nasopharyngeal cooling,the bilateral common carotid arteries were occluded for 15 min followed by reperfusion,and hippocampal hypothermia was maintained at 32.5-33.5 ℃ for 1 h.In DM and LY groups,DMSO and LY294002 5 μl were injected into the left ventricle,respectively,and 20 min later the other procedures were similar to those previously described in group H.At 8 h of reperfusion,6 rats were sacrificed,and hippocampal specimens were obtained to detect the expression of pFoxO3a,Bcl-2 and Bax (by immuno-histochemistry).The expression of phosphor-Akt (p-Akt) was determined by Western blot.Results Compared with group S,the expression of p-Akt,pFoxO3a and Bcl-2 was significantly up-regulated in I/R,H and DM groups,the expression of Bcl-2 was down-regulated,and the ratio of Bcl-2/Bax was increased in H and DM groups,and the ratio of Bcl-2/Bax was decreased in I/R and LY groups.Compared with group I/R,the expression of p-Akt,pFoxO3a and Bcl-2 was significantly up-regulated,the expression of Bcl-2 was down-regulated,and the ratio of Bcl-2/ Bax was increased in H and DM groups.Compared with H and DM groups,the expression of p-Akt,pFoxO3a and Bcl-2 was down-regulated,the expression of Bax was up-regulated,and the ratio of Bcl-2/ Bax was decreased in group LY.Conclusion PI3K/Akt signaling pathway is involved in reduction of global cerebral I/R injury by mild head hypothermia in rats.

Objective To evaluate the effect of low-dose norepinephrine (NE) combined with goal-directed fluid therapy (GDFT) on cerebral oxygen metabolism in patients undergoing intracranial tumor resection.Methods Forty patients of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,aged ≥ 18 yr,scheduled for elective intracranial tumor resection,were divided into 2 groups (n =20 each) using a random number table method:GDFT group (group G) and low-dose NE combined with GDFT group (group N).Fluid was replaced according to stroke volume variation (SVV) under the guidance of Flotrac-Vigileo system in both groups.When SVV ≤13％,fluid was replaced at 1-2 ml · kg-1 · h-1.When SVV＞ 13％ for more than 5 min,fluid replacement was enhanced to reduce it below 13％.In group N,NE was infused continuously via the central vein at 0.01-0.03 μg· kg-1 · min-1 after anesthesia induction,and mean arterial pressure (MAP) was maintained ≥ 65 mmHg.After anesthesia induction (T1),when the dura of brain was opened (T2),at 1 h after opening the dura (T3) and at the end of surgery (T4),the heart rate and MAP were recorded,and blood samples were collected from the internal jugular venous bulb and radial artery for blood gas analysis.The fluid input and output were recorded.Arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,cerebral oxygen extraction rate,cerebral lactic acid production rate and ratio of cerebral blood flowto cerebral oxygen metabolic rate were calculated.Results Compared with group G,MAP at T4 and cerebral oxygen extraction rate at T3,4 were significantly increased,the total volume of fluid and volume of crystalloid solution were decreased (P＜0.05),and no significant change wasfound in arterial oxygen content,jugular bulb venous oxygen content,arteriovenous oxygen content difference,ratio of cerebral blood flow to cerebral oxygen metabolic rate or cerebral lactic acid production rate in group N (P＞0.05).Conclusion Low-dose NE combined with GDFT can reduce the intraoperative volume of fluid infused and improve cerebral oxygen supply when applied to the patients undergoing intracranial tumor resection.