Objective:To evaluate the role of docosahexaenoic acid (DHA) in long-term cognitive impairment after multiple sevoflurane anesthesia in newborn mice.Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, were used in this study. Ten mice were divided into 2 groups ( n=5 each) by the random number table method: control group (group C) and sevoflurane group (group S). The animals inhaled 3% sevoflurane for 2 h at 6, 7 and 8 days after birth. The DHA content was detected by ultra-high performance liquid chromatography-mass spectrometry at 9 days of age. Fifty-two mice were selected and divided into 4 groups ( n=13 each) by a random number table method: control+ normal saline group (group C+ S), sevoflurane anesthesia + normal saline group (group S+ S), control+ DHA group (group C+ D), and sevoflurane anesthesia+ DHA group (group S+ D). The sevoflurane anesthesia method was the same as the one mentioned above. DHA 50 mg/kg was administered by intragastric gavage from postnatal days 6-19 (at 6, 7 and 8 days after birth, 2 h before anesthesia) in C+ D and S+ D groups. The equal volume of normal saline was given instead in C+ S group and S+ S group. The novel object recognition test was conducted at 37 days of age, and the Morris water maze test was performed at 42 days of age. The corpus callosum and hippocampal tissues were isolated at 47 days of age for examination of the ultrastructure of myelin (with a transmission electron microscope) and for determination of the expression of myelin basic protein (MBP) in hippocampal tissues (by Western blot). The G-ratio was calculated. Results:Compared with group C, the content of DHA in hippocampal tissues was significantly decreased in group S ( P<0.05). Compared with group C+ S, the discrimination index was significantly decreased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were decreased, the expression of MBP was down-regulated, and the G-ratio in the original platform and hippocampus was increased in S+ S group ( P<0.05). Compared with group S+ S, the discrimination index was significantly increased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were increased, the expression of MBP was up-regulated, and the G-ratio in the original platform and hippocampus was decreased in S+ D group ( P<0.05). Conclusions:The mechanism of long-term cognitive impairment following multiple sevoflurane anesthesia may be related to a decrease in the content of DHA, which subsequently leads to myelin structural damage in neonatal mice.

Objective:To evaluate the effect of multiple sevoflurane anesthesia on the metabolism of long-chain fatty acids in the hippocampus of newborn mice and the role of peroxisome proliferator-activated receptor-beta (PPARβ).Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, weighing 3-5 g, were divided into 2 groups ( n=8 each) by a random number table method: control group (group C) and multiple sevoflurane anesthesia group (group S). This study was performed in 2 parts. PartⅠ Sixteen newborn mice were divided into 2 groups ( n=8 each) using a random number table: control group (C group) and multiple sevoflurane anesthesia group (S group). Anesthesia was performed with sevoflurane on postnatal days 6, 7 and 8. The hippocampus was obtained at postnatal day 9 for determination of the content of long-chain fatty acids (by ultra-high performance liquid mass spectrometry), expression of PPARβ (by Western blot), and expression of stearoyl-CoA desaturase-2 (Scd2) and fatty acid desaturase 2 (Fads2) mRNA (using quantitative real-time polymerase chain reaction). Part Ⅱ Twenty-one newborn mice were divided into 3 groups ( n=7 each) using a random number table: control+ normal saline group (group C+ S), sevoflurane + normal saline group (group S+ S), and sevoflurane+ PPARβ specific agonist KD3010 group (group S+ K). Anesthesia was carried out with sevoflurane on postnatal days 6, 7 and 8. KD3010 25 mg/kg was intraperitoneally injected once a day from postnatal day 6 to 13 in S+ K group. The novel object recognition test was performed on postnatal day 37, and the Morris water maze test was performed on postnatal day 42. The hippocampal tissues were obtained on postnatal day 47 for detection of the expression of Scd2 mRNA and Fads2 mRNA by fluorescent quantitative real-time polymerase chain reaction. Anesthesia was carried out with sevoflurane as follows: Mice were exposed to 3% sevoflurane in 40% oxygen-60% nitrogen in an induction chamber for 2 h at a flow rate of 1 L/min. Results:PartⅠ Compared with group C, the total content of long-chain fatty acids, contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were significantly decreased, the percentage of saturated fatty acids was increased, the percentage of monounsaturated fatty acids and polyunsaturated fatty acids was decreased, the expression of Scd2 mRNA and Fads2 mRNA was down-regulated, and the expression of PPARβ was down-regulated in group S ( P<0.05). Part Ⅱ Compared with group C+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly decreased, the number of crossing the original platform was reduced, and the expression of Scd2 and Fads2 mRNA was down-regulated in group S+ S ( P<0.05). Compared with group S+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly increased, the number of crossing the original platform was increased, and the expression of Scd2 and Fads2 mRNA was up-regulated in group S+ K ( P<0.05). Conclusions:Multiple anesthesia with sevoflurane can lead to the disorder of long-chain fatty acid metabolism in the hippocampus of neonatal mice, resulting in long-term cognitive dysfunction. The mechanism may be related to inhibiting the activity of hippocampal PPARβ signaling pathway.

Objective:To evaluate the role of docosahexaenoic acid (DHA) in long-term cognitive impairment after multiple sevoflurane anesthesia in newborn mice.Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, were used in this study. Ten mice were divided into 2 groups ( n=5 each) by the random number table method: control group (group C) and sevoflurane group (group S). The animals inhaled 3% sevoflurane for 2 h at 6, 7 and 8 days after birth. The DHA content was detected by ultra-high performance liquid chromatography-mass spectrometry at 9 days of age. Fifty-two mice were selected and divided into 4 groups ( n=13 each) by a random number table method: control+ normal saline group (group C+ S), sevoflurane anesthesia + normal saline group (group S+ S), control+ DHA group (group C+ D), and sevoflurane anesthesia+ DHA group (group S+ D). The sevoflurane anesthesia method was the same as the one mentioned above. DHA 50 mg/kg was administered by intragastric gavage from postnatal days 6-19 (at 6, 7 and 8 days after birth, 2 h before anesthesia) in C+ D and S+ D groups. The equal volume of normal saline was given instead in C+ S group and S+ S group. The novel object recognition test was conducted at 37 days of age, and the Morris water maze test was performed at 42 days of age. The corpus callosum and hippocampal tissues were isolated at 47 days of age for examination of the ultrastructure of myelin (with a transmission electron microscope) and for determination of the expression of myelin basic protein (MBP) in hippocampal tissues (by Western blot). The G-ratio was calculated. Results:Compared with group C, the content of DHA in hippocampal tissues was significantly decreased in group S ( P<0.05). Compared with group C+ S, the discrimination index was significantly decreased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were decreased, the expression of MBP was down-regulated, and the G-ratio in the original platform and hippocampus was increased in S+ S group ( P<0.05). Compared with group S+ S, the discrimination index was significantly increased, the percentage of duration of staying at the target platform quadrant and the number of crossing the original platform were increased, the expression of MBP was up-regulated, and the G-ratio in the original platform and hippocampus was decreased in S+ D group ( P<0.05). Conclusions:The mechanism of long-term cognitive impairment following multiple sevoflurane anesthesia may be related to a decrease in the content of DHA, which subsequently leads to myelin structural damage in neonatal mice.

Objective:To evaluate the effect of multiple sevoflurane anesthesia on the metabolism of long-chain fatty acids in the hippocampus of newborn mice and the role of peroxisome proliferator-activated receptor-beta (PPARβ).Methods:Clean-grade healthy male C57BL/6 mice, aged 6 days, weighing 3-5 g, were divided into 2 groups ( n=8 each) by a random number table method: control group (group C) and multiple sevoflurane anesthesia group (group S). This study was performed in 2 parts. PartⅠ Sixteen newborn mice were divided into 2 groups ( n=8 each) using a random number table: control group (C group) and multiple sevoflurane anesthesia group (S group). Anesthesia was performed with sevoflurane on postnatal days 6, 7 and 8. The hippocampus was obtained at postnatal day 9 for determination of the content of long-chain fatty acids (by ultra-high performance liquid mass spectrometry), expression of PPARβ (by Western blot), and expression of stearoyl-CoA desaturase-2 (Scd2) and fatty acid desaturase 2 (Fads2) mRNA (using quantitative real-time polymerase chain reaction). Part Ⅱ Twenty-one newborn mice were divided into 3 groups ( n=7 each) using a random number table: control+ normal saline group (group C+ S), sevoflurane + normal saline group (group S+ S), and sevoflurane+ PPARβ specific agonist KD3010 group (group S+ K). Anesthesia was carried out with sevoflurane on postnatal days 6, 7 and 8. KD3010 25 mg/kg was intraperitoneally injected once a day from postnatal day 6 to 13 in S+ K group. The novel object recognition test was performed on postnatal day 37, and the Morris water maze test was performed on postnatal day 42. The hippocampal tissues were obtained on postnatal day 47 for detection of the expression of Scd2 mRNA and Fads2 mRNA by fluorescent quantitative real-time polymerase chain reaction. Anesthesia was carried out with sevoflurane as follows: Mice were exposed to 3% sevoflurane in 40% oxygen-60% nitrogen in an induction chamber for 2 h at a flow rate of 1 L/min. Results:PartⅠ Compared with group C, the total content of long-chain fatty acids, contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were significantly decreased, the percentage of saturated fatty acids was increased, the percentage of monounsaturated fatty acids and polyunsaturated fatty acids was decreased, the expression of Scd2 mRNA and Fads2 mRNA was down-regulated, and the expression of PPARβ was down-regulated in group S ( P<0.05). Part Ⅱ Compared with group C+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly decreased, the number of crossing the original platform was reduced, and the expression of Scd2 and Fads2 mRNA was down-regulated in group S+ S ( P<0.05). Compared with group S+ S, the discrimination index in the novel object recognition test and percentage of time spent in the target quadrant were significantly increased, the number of crossing the original platform was increased, and the expression of Scd2 and Fads2 mRNA was up-regulated in group S+ K ( P<0.05). Conclusions:Multiple anesthesia with sevoflurane can lead to the disorder of long-chain fatty acid metabolism in the hippocampus of neonatal mice, resulting in long-term cognitive dysfunction. The mechanism may be related to inhibiting the activity of hippocampal PPARβ signaling pathway.

Objective:To evaluate the effect of lipoxin A4 on lipopolysaccharide (LPS)-induced activation of microglia and role of silent information regulator sirtuin 1 (SIRT1)/NF-κB signaling pathway.Methods:This experiment was performed in two parts.PartⅠ The well-growth BV2 microglia were divided into 4 groups ( n=30 each) using a random number table method: control group (group C), LXA4 group (group LXA4), LPS group (group LPS) and LPS+ LXA4 group (group LLI). PartⅡ The well-growth BV2 microglia were divided into 2 groups ( n=30 each) using a random number table method: LPS+ LXA4 group (group LL2) and LPS+ LXA4+ SIRT1 inhibitor EX527 group (group LLE). Cells in group C were commonly cultured without any treatment. In LXA4 group and LPS group, LXA4 (final concentration 100 nmol/L) and LPS (final concentration 100 ng/ml) were added respectively, and then the cells were incubated for 24 h. In LL1 group and LL2 group, LXA4 (final concentration 100 nmol/L) was added at 1 h before treatment with LPS, and the other treatments were similar to those previously described in LPS group. EX527 (final concentration of 5 μmol/L) was added at 30 min before treatment with LXA4, and the other treatments were similar to those previously described in LL2 group.The expression of inducible nitricoxide synthase (iNOS), CD32, arginine synthase 1 (Arg-1), CD206, interleuckin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α) and IL-10 mRNA was detected by real-time polymerase chain reaction. The concentrations of IL-1β, IL-6, TNF-α and IL-10 in the supernatant were measured using enzyme-linked immunosorbent assay. The content of ROS was detected by DCFH-DA. The activity of SOD was measured by WST-8 assay. The expression of NADPH oxidase 2 (NOX2), superoxide dismutase 1 (SOD1), heme oxygenase-1 (HO-1), SIRT1 and acetylated NF-κB p65 was detected by Western blot. Results:Compared with group C, the expression of iNOS, CD32, IL-1β, IL-6 and TNF-α mRNA was significantly up-regulated, the concentrations of IL-1β, IL-6 and TNF-α in the supernatant were increased ( P<0.05), no significant change was found in the expression of Arg-1, CD206 and IL-10 mRNA and IL-10 concentrations in the supernatant, the expression of NOX2 and HO-1 was up-regulated, SOD1 expression was down-regulated, the activity of SOD was decreased, the content of ROS was increased, the expression of SIRT1 was down-regulated, and the expression of acetylated NF-κB p65 was up-regulated in group LPS ( P<0.05). Compared with group LPS, the expression of iNOS, CD32, IL-1β, IL-6 and TNF-α mRNA was significantly down-regulated, the expression of Arg-1, CD206 and IL-10 mRNA was up-regulated, concentrations of IL-1β, IL-6 and TNF-α in the supernatant were decreased, the concentration of IL-10 was increased, the expression of NOX2 was down-regulated, the expression of HO-1 and SOD1 was up-regulated, the activity of SOD was increased, the content of ROS was decreased, the expression of SIRT1 was up-regulated, and the expression of acetylated NF-κB p65 was down-regulated in group LL1 ( P<0.05). Compared with group LL2, the concentrations of IL-1β, IL-6 and TNF-α in the supernatant were significantly increased, the activity of SOD was decreased, the content of ROS was increased ( P<0.05), and no significant change was found in the IL-10 concentration in the supernatant in group LLE ( P>0.05). Conclusions:LXA 4 can inhibit LPS-induced polarization of microglia to M1 phenotype, and the mechanism may be related to enhancement of SIRT1 activity and inhibition of NF-κB transcriptional activity.

Objective:To determine the optimal concentration of inhaled oxygen in pediatric patients undergoing laparoscopic choledochal cyst resection under general anesthesia.Methods:Seventy-five pediatric patients of both sexes, aged 1-3 yr, of American Society of Anesthesiologists Physical Status classification Ⅱ or Ⅲ, with body mass index of 15-18 kg/m 2, with expected operation time≥3 h, scheduled for elective laparoscopic choledochal cyst resection with general anesthesia, were divided into 3 groups ( n=25 each) using a random number table method: C 40 group (FiO 2=40%), C 30 group (FiO 2=30%) and C 21 group (FiO 2=21%). Blood samples were collected from the radial artery for blood gas analysis after operation for determination of oxygenation index (OI), respiratory index (RI), alveolar-arterial oxygen partial pressure difference (PA-aO 2) and arterial-alveolar oxygen partial pressure ratio (PaO 2/PAO 2). The occurrence of high risk events of hypoxia (SpO 2<94%), extubation time, and occurrence of pneumonia and atelectasis at day 7 after operation were recorded. Results:Compared with C 21 group, PaO 2, PAO 2, PA-aO 2 and RI were significantly increased, PaO 2/PAO 2 was decreased, and the incidence of high risk events of hypoxia was decreased in C 30 and C 40 groups, and the incidence of atelectasis in C 30 group and pneumonia and atelectasis in C 40 group was increased at day 7 after operation ( P<0.05). Compared with C 30 group, PaO 2, PAO 2, PA-aO 2 and RI were significantly increased, and PaO 2/PAO 2 was decreased in C 40 group ( P<0.05). Conclusions:The optimal concentration of inhaled oxygen recommended is 21%-30% in the pediatric patients undergoing laparoscopic choledochal cyst resection under general anesthesia.

Objective:To evaluate the relationship between early postoperative cognitive dysfunction and neuromodulator protein 1β(NRG1β) in aged rats.Methods:Pathogen-free healthy male Sprague-Dawley rats, aged 18-20 months, weighing 600-700 g, were divided into 3 groups ( n=10 each) using a random number table method: control group (group C), operation group (group O) and NRG1β group (group N). Exploratory laparotomy was performed in group O and group N. NRG1β 0.5 μg/kg was slowly injected into the lateral ventricle on 1 day before surgery in group N, while the equal volume of 0.1 mol/L phosphate buffer solution was given instead in C and O groups.Learning and memory function was assessed using Morris water maze test performed at day 3 after operation.The rats were then sacrificed, and the hippocampi were removed for determination of the expression of nuclear factor kappa B (NF-κB) p65 (by Western blot) and contents of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay). Results:Compared with group C, the postoperative escape latency was significantly prolonged, the expression of NF-κB p65 was up-regulated, and the contents of IL-1β and TNF-α were increased in group O and group N ( P<0.05). Compared with group O, the postoperative escape latency was significantly shortened, the expression of NF-κB p65 was down-regulated, and the contents of IL-1β and TNF-α were decreased in group N ( P<0.05). Conclusion:NRG1β is involved in the endogenous protective mechanism of early postoperative cognitive dysfunction probably by inhibiting the activation of NF-κB pathway and inhibiting inflammatory responses in aged rats.

Objective:To evaluate the changes in the expression of hippocampal HSP70 during postoperative cognitive dysfunction in aged rats.Methods:Twelve pathogen-free healthy male Sprague-Dawley rats, aged 18 weeks, weighing 500-650 g, were divided into 2 groups ( n=6 each) using a random number table method: old control group (group O) and old surgery group (group OS). Another 12 pathogen-free healthy male Sprague-Dawley rats served as control and divided into 2 groups ( n=6 each) according to a random number table method: adult control group (group A) and adult surgery group (group AS). Exploratory laparotomy was performed in group AS and group OS.Morris water maze test was performed at 3 days after operation, and then the rats were sacrificed, and the hippocampi were removed for determination of the expression of heat shock protein 70 (HSP70) (by Western blot) and contents of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay). Results:Compared with group A, the expression of HSP70 was significantly up-regulated ( P<0.05), and no significant change was found in the other indices in group AS ( P>0.05). Compared with group O, the escape latency was significantly prolonged, the frequency of crossing platform was decreased, the contents of IL-1β and TNF-α were increased, and the expression of HSP70 was up-regulated in group OS ( P<0.05). Compared with group AS, the escape latency was significantly prolonged, the frequency of crossing platform was decreased, the contents of IL-1β and TNF-α were increased ( P<0.05), and no significant change was found in the expression of HSP70 in group OS ( P>0.05). Conclusion:HSP70 expression in hippocampi is up-regulated during postoperative cognitive dysfunction and is helpful in inhibiting the inflammatory response and exerting endogenous neuroprotective effect in aged rats.

Objective To determine the median effective concentration(EC50)of sevoflurane in?hibiting responses to laryngeal mask airway(LMA)removal in pediatric patients under comprehensive clin?ical conditions. Methods Twenty?six pediatric patients of both sexes, aged 1-5 yr, with body mass index of 15-20 kg∕m2, of American Society of Anesthesiologists physical statusⅠ, scheduled for elective minor surgery, were enrolled in this study. Anesthesia was induced by inhaling 8% sevoflurane and injecting dezocine 0.1 mg∕kg. The LMA painted with Teracainum Plasmagel was inserted. Anesthesia was maintained by sevoflurane inhalation and target?controlled infusion of remifentanil. Remifentanil infusion was stopped at 5 min before the end of surgery. At the end of surgery, the end?tidal concentration of sevoflurane was main?tained at the target concentration for at least 10 min and then the laryngeal mask airway was removed. The end?tidal concentration of sevoflurane was determined by using Dixon′s up?and?down sequential method. The end?tidal concentration of sevoflurane was set at 0.8% in the first pediatric patient. Each time the concen?tration of sevoflurane increased∕decreased by 0.1% in the next pediatric patient according to patient′s re?sponses to LMA removal. Results The EC50of sevoflurane inhibiting responses to LMA removal was 0.59%, and the 95% confidence interval was 0.55%-0.63% in pediatric patients under comprehensive clinical conditions. Conclusion The EC50of sevoflurane inhibiting responses to LMA removal is 0.59% in pediatric patients under comprehensive clinical conditions.

Objective To observe the effects of obesity on dose-response curve of rocuronium in female patients and calculate ED9 5 of rocuronium.Methods Eighty female patients,aged 18-45 years, falling into ASA grade Ⅰ or Ⅱ,schedualed for elective surgery under general anesthesia,undergoing surgery less than 1.5 h,were included in the study.The patients with body mass index of 20-25 kg/m2 as group N were randomized to divided group N1,group N2,group N3 and group N4.Anoth-er 40 patients with body mass index of 30-35 kg/m2 as group B were randomized to divided group B1, group B2,group B3 and group B4.When the first twitch height of TOF (T1)was 100%,groups N1-N4 and groups B1-B4 patients were injected rocuronium 0.075,0.1,0.1 5,0.3 mg/kg respectively. The first dose of rocuronium in each group,T1 maximum inhibition degree and onset time were re-corded.The relationship between probit-transformed depression of T1 and the logarithm dose of rocu-ronium was analyzed by linear regression.ED50 and ED9 5 of rocuronium in obese and normal body weight patients were calculated.Results Dose-response curve equation of each group were Y1 =3.464X1 -2.23 and Y2 = 3.843X2 - 2.750 respectively(P < 0.05 ).The ED50 and ED9 5 (95% CI)of rocuronium were 0.122 (0.092-0.1 65 )mg/kg and 0.324 (0.242-0.433 )mg/kg in group N,and were 0.103 (0.078-0.133)mg/kg and 0.25 1 (0.1 93-0.326)mg/kg in group B.Conclusion Obesity significantly affects the dose-response curve of young women and can enhance the sensitivity of them to the rocuronium.The ED9 5 of obese patients is 0.25 1 mg/kg.