Objective To investigate the effect of dexmedetomidine on the median effect concentration(EC50)of ropivacaine during sciatic nerve block combined with femoral nerve block in patients undergoing lower extremity surgery.Methods Patients with sciatic nerve block combined with femoral nerve block anesthesia who underwent lower extremity surgery from November 2021 to November 2023 were selected as the study objects.They were randomly divided into control group(0.9％saline),group D1(0.50 μg·kg-1 dexmedetomidine),group D2(0.75 μg·kg-1 dexmedetomidine)and group D3(1.00 μg·kg-1 dexmedetomidine).The stress response,serum pain mediators,vital signs and visual analogue scale(VAS)of patients at different time points during operation were analyzed by repeated measures ANOVA.ropivacaine EC50 was measured by sequential method,and the relationship between dexmedetomidine dose and ropivacaine EC50 was analyzed by Logistic regression.Results A total of 208 patients were include and each group was 52 patients.Compared with the same group before surgery,the stress response level of the 4 groups after surgery and 1 h after surgery was significantly decreased,and the serum pain mediators level was significantly increased(P＜0.05).Compared with the control group,the stress response and serum pain mediators levels in groups D1,D2 and D3 were more normal after surgery and 1 h after surgery,among them,group D3 was most close to the normal value(P＜0.05).There were no significant differences in blood oxygen saturation and bifrequency index of EEG among the four groups at each time point(P＞0.05).At T1 and T2,the heart rate(HR)of the control group was significantly higher than that of the group D2 and D3(P＜0.05).At T1,the control group had a significantly higher mean arterial pressure(MAP)than the other three groups,at T2,the control group had a significantly higher MAP than the group D2 and D3,and at T3,the control group had a significantly higher MAP than the group D3(P＜0.05).VAS scores in 4 groups were significantly lower after surgery and 1 h after surgery than before surgery(P＜0.05).The VAS score in group D3 was significantly lower than that in group D1 and D2(P＜0.05).Repeated measurement ANOVA showed that the effects of time on stress response and serum pain mediators were different with different anesthesia methods.The influence of time on HR,MAP and VAS scores varied with different anesthesia methods.Sequential assay results showed that the EC50 of ropivacaine in control group,group D1,group D2 and group D3 was 5.985,5.631,5.329 and 5.125 μg·mL-1,respectively.Logistic results showed that the dose of dexmedetomide was a protective factor for ropivacaine EC50 in sciatic nerve block combined with femoral nerve block in limb surgery patients(P＜0.05).Conclusion The ropivacaine EC50 can be significantly reduced by 1.00 μg·kg-1 dexmedetomidine.This is a protective factor for sciatic nerve block combined with femoral nerve block in patients undergoing lower limb surgery,and it can be applied clinically.

Objective To elucidate the regulatory effects of titanium surface modification on the immune function of immature dendritic cells(imDCs),different crystalline nanomorphologies were constructed on titanium surface to investigate the mechanobiological response of imDCs to nanomorphologies with different crystalline phases.Methods Nanomorphologies with different crystalline phases were constructed on the titanium surface by anodic oxidation and calcination.The changes of the cytoskeleton F-actin,cell adhesion and morphology of imDCs cultured on nanomorphologies with different crystalline phases were observed by fluorescence staining.The relative gene expression of adhesion molecules was detected by quantitative real-time PCR.The migration behaviors of imDCs were observed using real-time live-cell imaging,and the membrane fluidity was detected by fluorescence polarization.Results Nanomorphologies with different crystalline phases,namely amorphous phase,anatase and rutile,were obtained on the titanium surface by anodic oxidation and calcination.The cytoskeleton of imDCs on nanomorphologies with different crystalline phases was remodeled.The spreading area of cells on anatase crystalline phase was relatively small,which was(353.3±148.5)μm2.The number of adherent cells was the largest,which was 587±132.The expression of adhesion molecules such as CD11a,integrin β2,ICAM1,and VCAM1 were also increased in cells which cultured on anatase crystalline phase.The imDCs cultured on anatase crystalline phase were equipped with strong migration ability.The accumulative migration distance was(383.6±177.7)μm,and the Euclidean migration distance was(51.82±50.13)μm.The membrane fluidity was relatively weak,and the fluorescence polarization was 0.348 5±0.041 8.Conclusions imDCs can respond to nanomorphologies with different crystalline phases on the titanium surface and exhibit different biomechanical behaviors.The results might provide a theoretical basis for the design of titanium biomaterials with immunomodulatory functions.

Objective To elucidate the regulatory effects of titanium surface modification on the immune function of immature dendritic cells(imDCs),different crystalline nanomorphologies were constructed on titanium surface to investigate the mechanobiological response of imDCs to nanomorphologies with different crystalline phases.Methods Nanomorphologies with different crystalline phases were constructed on the titanium surface by anodic oxidation and calcination.The changes of the cytoskeleton F-actin,cell adhesion and morphology of imDCs cultured on nanomorphologies with different crystalline phases were observed by fluorescence staining.The relative gene expression of adhesion molecules was detected by quantitative real-time PCR.The migration behaviors of imDCs were observed using real-time live-cell imaging,and the membrane fluidity was detected by fluorescence polarization.Results Nanomorphologies with different crystalline phases,namely amorphous phase,anatase and rutile,were obtained on the titanium surface by anodic oxidation and calcination.The cytoskeleton of imDCs on nanomorphologies with different crystalline phases was remodeled.The spreading area of cells on anatase crystalline phase was relatively small,which was(353.3±148.5)μm2.The number of adherent cells was the largest,which was 587±132.The expression of adhesion molecules such as CD11a,integrin β2,ICAM1,and VCAM1 were also increased in cells which cultured on anatase crystalline phase.The imDCs cultured on anatase crystalline phase were equipped with strong migration ability.The accumulative migration distance was(383.6±177.7)μm,and the Euclidean migration distance was(51.82±50.13)μm.The membrane fluidity was relatively weak,and the fluorescence polarization was 0.348 5±0.041 8.Conclusions imDCs can respond to nanomorphologies with different crystalline phases on the titanium surface and exhibit different biomechanical behaviors.The results might provide a theoretical basis for the design of titanium biomaterials with immunomodulatory functions.

Objective To investigate the effect of dexmedetomidine on the median effect concentration(EC50)of ropivacaine during sciatic nerve block combined with femoral nerve block in patients undergoing lower extremity surgery.Methods Patients with sciatic nerve block combined with femoral nerve block anesthesia who underwent lower extremity surgery from November 2021 to November 2023 were selected as the study objects.They were randomly divided into control group(0.9％saline),group D1(0.50 μg·kg-1 dexmedetomidine),group D2(0.75 μg·kg-1 dexmedetomidine)and group D3(1.00 μg·kg-1 dexmedetomidine).The stress response,serum pain mediators,vital signs and visual analogue scale(VAS)of patients at different time points during operation were analyzed by repeated measures ANOVA.ropivacaine EC50 was measured by sequential method,and the relationship between dexmedetomidine dose and ropivacaine EC50 was analyzed by Logistic regression.Results A total of 208 patients were include and each group was 52 patients.Compared with the same group before surgery,the stress response level of the 4 groups after surgery and 1 h after surgery was significantly decreased,and the serum pain mediators level was significantly increased(P＜0.05).Compared with the control group,the stress response and serum pain mediators levels in groups D1,D2 and D3 were more normal after surgery and 1 h after surgery,among them,group D3 was most close to the normal value(P＜0.05).There were no significant differences in blood oxygen saturation and bifrequency index of EEG among the four groups at each time point(P＞0.05).At T1 and T2,the heart rate(HR)of the control group was significantly higher than that of the group D2 and D3(P＜0.05).At T1,the control group had a significantly higher mean arterial pressure(MAP)than the other three groups,at T2,the control group had a significantly higher MAP than the group D2 and D3,and at T3,the control group had a significantly higher MAP than the group D3(P＜0.05).VAS scores in 4 groups were significantly lower after surgery and 1 h after surgery than before surgery(P＜0.05).The VAS score in group D3 was significantly lower than that in group D1 and D2(P＜0.05).Repeated measurement ANOVA showed that the effects of time on stress response and serum pain mediators were different with different anesthesia methods.The influence of time on HR,MAP and VAS scores varied with different anesthesia methods.Sequential assay results showed that the EC50 of ropivacaine in control group,group D1,group D2 and group D3 was 5.985,5.631,5.329 and 5.125 μg·mL-1,respectively.Logistic results showed that the dose of dexmedetomide was a protective factor for ropivacaine EC50 in sciatic nerve block combined with femoral nerve block in limb surgery patients(P＜0.05).Conclusion The ropivacaine EC50 can be significantly reduced by 1.00 μg·kg-1 dexmedetomidine.This is a protective factor for sciatic nerve block combined with femoral nerve block in patients undergoing lower limb surgery,and it can be applied clinically.

Objective To explore the clinical feasibility of robot-assisted laparoscopic radical cystectomy (RARC) with total intracorporeal othotopic ileal neobladder (TIOIN).Methods A consecutive series of 4 patients (2 male,2 female),who underwent RARC with TIOIN by a single surgeon,were included in the retrospective study,between March 2017 and June 2017.Their age ranged from 59 to 71 years,which the mean age was (65.7 ± 4.9) years.Preoperative urinary CT scan,cystoscopic examination and transurethral resection of bladder tumor were performed for diagnosis.Among these,2 patients underwent side-to-side bowel anastomosis using a linear stapler,while hand-sewn anastomosis was performed in the other 2 patients.The detubularized bowel segment was arranged in a U shape,and then the two medial borders were closed to create the posterior wall of the neobladder,which completed a partial U shape and anastomosed with the end of urethra.After placing the single J stents into the ureter,the uretero-neobladder was anastomosed.To close the urine reservoir,each border of the U-shaped segment was folded again and sutured to form a sealed pouch.Results All operations were performed successfully.The average operation time for RARC was 93.2 min (ranging 79-117 min).The average operation time for urinary diversion was 214.2 min (ranging 163-251 min).The mean estimated blood loss was 304.5 ml (ranging 200-400 ml).The mean hospital stay was 20.5 d (ranging 13-32 day).The number of dissected lymph node ranged from 11 to 16 (mean 3.7 ± 2.6).All the surgical margins were negative.The time for postoperative out-of-bed activity and bowel function recovery was 2-3 days and 3-4 days,respectively.The single-J stents were removed 1 months after operation,generally.No urine leakage was noticed after removing the drainage tube and catheter.The lymph leakage was observed in one case,which was resolved 15 days post-operatively after given nutrient therapy.The performance of urinary continence was satisfactory,except one patient complained about the nocturnal incontinence.After the regular pelvic exercise,the symptom improved two months after the operation.Hydronephrosis and intestinal leakage were not observed.Conclusions Our initial experience showed that RARC with TIOIN is feasible and alterative for experienced surgeon.

Objective To evaluate the stability of the pelvic ring reconstruction using fibular autograft for periacetabular tumor type Ⅱ resection. Methods 6 adult cadaveric specimens were tested. The periacetabular tumor resection models were established according to Ennecking's type Ⅱ resection. The resected pelvic rings were reconstructed with double-fibular graft fixed by four internal fixation techniques including plates, pedicle-rods (PR), lateral-rods (LR) or sacral-iliac rods (SIR). Axial loading from the proximal L3 vertebral body was applied by MTS load cell in the gradient of 0～500 N in the double feet standing state. Images in front view were obtained using CCD camera. Based on Image J software, displacement of the first sacral vertebrae （S1） of the reconstructed pelvis and intact pelvis were calculated using digital maker tracing method with center-of-mass algorithm. Results The rotational movements and vertical displacement of S1 around the normal side femoral head of the reconstructed pelvis in coronary plane were found in simulated bilateral leg standing position. The average vertical load-displacement and load-angular rotation curve of S1 in coronary plane were approximately linear behavior under the vertical load 500 N. The average vertical displacement and angle of S1 in coronary plane had not overacted. The stability of axial direction and rotation had not changed significantly when reconstructed by LR or Plates compared with the intact pelvis, but the SIR did. Conclusion Plates and LR fixation were more stabile for periacetabular tumor type Ⅱ resection.

Objective To measure stress distribution of the main bone architecture of the normal adult cadaveric foot and discuss the effect of plantar ligament injury on stress distribution. Methods Seven fresh adult cadaveric feet were used and 10 strain gauges attached to the bones of the longitudinal foot arch,including the calcaneus,navicular,medial cuneiform,1-5 metatarsal trunk,the distal part of the tibia and fibular,respectively.After the loading Was added to 700 N by almighty test machine,resistance strainmeter was used to measure surface strain of these bones.The results were processed statistically. Results The strain was varied based on different bone segments attached and increased with loading.Tensile force was always found at the medial part of the navicular,the distal part of the tibia and fibular,while the others showed compression all the time.Peak strain was found at calcaneus.followed by the second and third metatarsal.Strain on the surface of the bone segments changed greatly with different ligament injury(P＜0.05).Conclusion The bone surface stress of the longitudinal foot arch changes significantly when the plantar ligament is injured.