ObjectiveTo investigate the effect of dexmedetomidine on the median effectivetarget effectsite concentration (EC50) of remifentanil required for preventing body movement in response to skin incision made under propofol sedation.MethodsForty ASA Ⅰ or Ⅱ patients aged 20-50 yr weighing 45-58 kg scheduled for elective breast tumor excision were randomly allocated into 2 groups ( n =20 each):group remifentanil (group R) and group remifentanil + demedetomidine ( group RD).Sedation was induced with propofol TCI at target plasma concentration of 3.0 mg/L in both groups.In group RD dexmedetomidine 1.0 μg/kg was infused iv over 10 min before start of propofol TCI,while in group R equal volume of normal saline was infused instead of dexmedetomidine.Remifentanil TCI was started with target effect-site concentration set at 3.0 and 2.5 μg/L in groups R and RD respective at 13 min after beginning of propofol TCI.Skin incision (3 cm in length) was made when the target concentrations of propofol and remifentanil TCI were reached.Body movement was assessed by a nurse not involved in this study.EC50 and 95％ confidence interval (CI) of remifentanil were determined by up-and-down technique.The target effect-site concentration was increased or decreased by 20％ depending on the response of the previous patient to skin-incision.ResultsThe EC50 of remifentanil for preventing body movement in response to skin incision performed under propofol sedation was 1.7 μg/L (95％ CI 1.5-1.9 μg/L) and 2.5 μg/L (95％ CI 2.2-2.7μg/L) in groups RD and R respectively.The EC50 of remifentanil was significantly lower in group RD than in group R.ConclusionDexmedetomidine 1.0 μg/kg can decrease EC50 of remifentanil for preventing body movement in response to skin incision made under propofol sedation.

0.05).According to the HSS system,the mean score was 92.1(ranged from 76-97) one year after operation.No complication occurred,such as deep infection,necrosis of skin incision or loosening and breakage of internal fixators.[Conclusion]This modified posteromedial and posterolateral approaches could reduce the complications in incision successfully for the direct reduction and buttress fixation of articular fragments,as well as and soft tissue.

Objective To investigate the effect of dexmedetomidine on bispectral index (BIS) value at loss of consciousness (LOC) caused by propofol given by target-controlled infusion (TCI).Methods One hundred and twenty ASA Ⅰ or Ⅱ patients,aged 20-50 yr,weighing 41-68 kg,scheduled for general surgery were randomly divided into 3 groups (n =40 each):propofol group (group P),dexmedetomidine 0.5 μg/kg + propofol group (group D1P) and dexmedetomidine 1.0 μg/kg + propofol group (group D2P).The patients in each group were randomly assigned into 5 subgroups ( n =8 each):groups P0-4 receiving TCI of propofol with the target effect-site concentration (Ce) set at0,1,2,3 and 4 mg/L respectively.Groups D1P0-4 received iv infusion of dexmedetomidine 0.5 μg/kg at a rate of0.05μg·kg-1 ·min-1 and TCI of propofol with the target Ce set at 0,1,2,3 and 4 mg/L respectively at 5 min after the end of dexmedetomidine infusion.Groups D2 P0-4 received iv infusion of dexmedetomidine 1.0 μg/kg at a rate of 0.1μg· kg- 1· min- 1 and TCI of propofol with the target Ce set at 0,1,2,3 and 4 mg/L respectively at 5 min after the end of dexmedetomidine infusion.Three minutes after TCI of propofol was started,OAA/S score and BIS value were recorded.The OAMS score ≤ 2 was defined as LOC.The EC50 and 95％ confidence interval of propofol for LOC and BIS50 and 95％ confidence interval at LOC were calculated by Probit analysis.Prediction probability (Pk) of BIS value at LOC was calculated using Smith method.Results Compared with group P,EC50 was significantly decreased,BIS50 was significantly increased ( P ＜ 0.05 or 0.01 ),and no significant change was found in Pk in groups D2 P and D1 P ( P ＞ 0.05).There were no significant differences in EC50,BIS50 and Pk between groups D2 P and D1P ( P ＞ 0.05).Conclusion BIS value can accurately predict the level of consciousness during anesthesia with dexmedetomidine and TCI of propofol,but BIS value is increased at LOC.

Objective To investigate the changes in the expression of neuromedin U receptor 2 (NMUR2) in spinal dorsal horn in a rat model of bone cancer pain (BCP).Methods Thirty-two female Sprague-Dawley rats,weighing 150-180 g,were randomly divided into 2 groups (n =16 each):sham operation group (group S) and BCP group.BCP was induced by inoculating Walker 256 mammary gland carcinoma cells (1 × 105) into the medullary cavity of left tibia.Heat-killed Walker 256 cells (1 × 105) were injected into the medullary cavity of left tibia in S group.Eight rats were chosen from each group and the paw withdrawal threshold (PWT) to yon Frey filaments was measured at 1 day before operation (baseline) and 1,3,6,9,12 and 15 days after operation.Bone destruction was shown by X-ray at 15 days after operation.At 1 day before operation and 15 days after operation,4 rats in each were chosen and sacrificed,and L4,5 segments of the spinal cord were removed for measurement of the expression of NMUR2 mRNA (by real-time PCR) and protein (using Western blot analysis) in the spinal dorsal horn.Results Compared with S group,the PWT was significantly decreased at day 6-15 after operation and the expression of NMUR2 mRNA and protein in the spinal dorsal horn was up-regulated at 15 days after operation in BCP group (P ＜ 0.05 or 0.01).Compared with the baseline value,the PWT was significantly decreased at day 6-15 after operation and the expression of NMUR2 mRNA and protein in the spinal dorsal horn was up-regulated at 15 days after operation in BCP group (P ＜ 0.05 or 0.01).X-ray showed defect of bone trabecula and cortical bone destruction in BCP group.Conclusion The expression of spinal NMUR2 is up-regulated in rats with BCP and this change may be involved in the development and maintenance of BCP.

Objective To investigate the relationship between T?cell death?associated gene 8 ( TD?AG8) and endogenous neuron?protective mechanism against oxygen?glucose deprivation and restoration ( OGD∕R)?induced apoptosis in rat neurons. Methods The primary cortical neurons obtained from fetal rats were seeded in 6?well plates at a density of 1×105 cells∕ml and divided into 5 groups using a random number table: control group ( group C, n=24 ) , group OGD∕R ( n=48 ) , TDAG8 agonist BTB09089 group (group BTB, n=24), TDAG8?siRNA group ( group siRNA, n=24), and blank vehicle group ( group V, n=24) . The medium was replaced with glucose?and serum?free Locke′s buffer, and the neu?rons were exposed to 95% N2?5% CO2 in an air?tight incubator at 37℃ for 60 min followed by routine cul?ture to establish the model of OGD∕R. In BTB, siRNA and V groups, 20 μmol∕L TDAG8 agonist
BTB09089, 200 pmol∕L TDAG8?siRNA, and 6 μl∕200 μl transfection reagent were added, respectively, at 24 h before oxygen?glucose restoration. At 6 h of oxygen?glucose restoration, the neuronal viability and a?mount of lactic dehydrogenase ( LDH) released were measured, and the expression of TDAG8 and caspase?3 mRNA in neurons was detected by fluorescent quantitative real?time polymerase chain reaction. In group OGD∕R, the expression of TDAG8 and caspase?3 was measured by Western blot at 0, 3, 6, 12 and 24 h of oxygen?glucose restoration. In C, OGD∕R, BTB, siRNA and V groups, the expression of TDAG8, caspase?3 and p?Akt was detected at 6 h of oxygen?glucose restoration. Results In group OGD∕R, the ex?pression of TDAG8 was gradually up?regulated after oxygen?glucose restoration, and the expression of caspase?3 peaked at 6 h of oxygen?glucose restoration. Compared with group C, the neuronal viability was significantly decreased, the amount of LDH released was significantly increased, and the expression of TD?AG8 and caspase?3 protein and mRNA and p?Akt was significantly up?regulated in OGD∕R, V and siRNA groups ( P<0?05) . Compared with group OGD∕R, the expression of TDAG8 protein and mRNA and p?Akt was significantly up?regulated, the expression of caspase?3 protein and mRNA was significantly down?regu?lated, the neuronal viability was significantly increased, and the amount of LDH released was significantly decreased in group BTB, the expression of TDAG8 protein and mRNA and p?Akt was significantly down?regulated, the expression of caspase?3 protein and mRNA was significantly up?regulated, the neuronal via?bility was significantly decreased, and the amount of LDH released was significantly increased in group siR?NA ( P<0?05) , and no significant change was found in the parameters mentioned above in group V ( P>0?05) . Conclusion TDAG8 is partially involved in the endogenous neuron?protective mechanism against OGD∕R?induced apoptosis in rat neurons, which may be related to activation of Akt signaling pathway.

Objective To determine the optimal pressure for facemask ventilation during induction of general anesthesia by real-time ultrasonographic measurement of antral cross-sectional area (CSA) in adult patients.Methods Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 18-60 yr,with body mass index of 20-25 kg/m2,scheduled for elective operation under general anesthesia,were divided into 5 groups (n=12 each) using a random number table:P10 group,P13 group,P16 group,P19 group and P22 group.After induction of anesthesia,an oropharyngeal airway was inserted,and the patients were ventilated for a 2-min period in a pressure-controlled mode using the two-handed mask ventilation technique.The pressure for facemask ventilation was 10,13,16,19 and 22 cmH2O in P10,P13,P16,P19 and P22 groups,respectively.The antral CSA was measured using real-time ultrasonography before and after facemask ventilation.Respiratory parameters were recorded.Results Compared with group P1O,the number of patients in whom CSA＜340 mm2 after facemask ventilation was significantly decreased in P16,P19 and P22 groups,and the number of patients in whom the tidal volume ≥ 6 ml/kg was increased in P13,P16,P19 and P22 groups (P＜ 0.01).The number of patients in whom optimnal pressure for facemask ventilation was achieved was 2,10,6,4 and 1 in P10,P13,P16,P19 and P22 groups,respectively,with the most cases in group P13 (P ＜ 0.01).Conclusion The optimal pressure is 13 emH2O for facemask ventilation during induction of general anesthesia when determined by realtime ultrasonographic measurement of antral CSA,and it can ensure adequate oxygen supply and reduce gastric insufflation in adult patients.

Objective:To investigate the effect of thoracolumbar osteoporotic vertebral compression fracture (OVCF) combined with lumbar degenerative spondylolisthesis (LDS) on spinopelvic sagittal parameters in the elderly.Methods:A case-control study was conducted to analyze the clinical data of 77 patients with thoracolumbar OVCF admitted to Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine from December 2016 to December 2021. There were 16 males and 61 females with the age of 61-92 years [(73.9±8.4)years]. All patients had single-level thoracolumbar fractures (T 11-L 2). Simple thoracolumbar OVCF was found in 49 patients (OVCF group) and thoracolumbar OVCF combined with LDS in 28 (OVCF+LDS group). The pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), sagittal vertical axis (SVA) and Roussouly types were detected and compared between the two groups before operation. Results:There was no significant difference in PT and SVA between the two groups (all P>0.05). The PI, SS, LL, TK and TLK in OVCF+LDS group were (55.8±11.0)°, (34.1±10.9)°, (45.7±9.1)°, (35.7±6.1)° and (24.8±5.2)°, significantly larger than (47.9±8.8)°, (27.0±9.4)°, (33.1±7.9)°, (29.5±6.2)° and (18.4±5.5)° in OVCF group (all P<0.01). Roussouly types I-IV counted 22, 16, 5 and 6 patients in OVCF group, compared to 8, 5, 6 and 9 patients in OVCF+LDS group ( P<0.05). Conclusions:Elderly patients with thoracolumbar OVCF combined with LDS can significantly alter spinopelvic sagittal parameters, and LDS may aggravate the thoracolumbar kyphosis of OVCF. To avoid sagittal imbalance, surgery should be performed as soon as possible.