Objective:To investigate the value of enhanced MRI in evaluating the tissue permeability of pancreatic ductal adenocarcinoma (PDAC) animal model.Methods:The experimental animals were 27 female C57BL/6 mice. The mice were divided into 3 groups with 9 mice in each group by random number method. Murine pancreatic adenocarcinoma (Panc02) and embryonic fibroblasts (NIH/3T3) were implanted subcutaneously at the ratio of 2∶1 and 1∶1 to establish PDAC models with different tissue permeability, which were low fibroblast group and high fibroblast group, respectively, and simple Panc02 implantation model was control group. The positive expression rate of α-smooth muscle actin (α-SMA), the positive expression rate of fibroblast activating protein (FAP), the coverage rate of collagen fibers, number of blood vessels and the long/short diameter of tissue vessels were quantitatively evaluated by tissue staining, and the tissue permeation efficiency was quantified by the average optical density (AOD) of tissue sections stained by Evans blue (EB). Enhanced MRI was performed on mice, and the enhancement degree and the enhancement rate of 20 min were obtained. One-way ANOVA was used to compare the overall differences of tumor histological indexes and MRI enhancement parameters in each group, and the correlation between the indexes was analyzed by Pearson correlation analysis. Multiple linear stepwise regression analysis was conducted with 20 min enhancement rate as dependent variable, while α-SMA positive expression rate, collagen fiber coverage rate and vascular long/short diameter as independent variables.Results:There were significant differences in AOD value, α-SMA positive expression rate, FAP positive expression rate, collagen fiber coverage rate, vascular long/short diameter, 20 min enhancement degree and 20 min enhancement rate among the three groups ( P<0.001), but there was no significant difference in the number of blood vessels ( P=0.650). The AOD value was negatively correlated with the positive expression rate of α-SMA, the coverage rate of collagen fibers and the long/short diameter of blood vessels in PDAC model, respectively ( r=-0.888, P=0.001; r=-0.813, P=0.008; r=-0.915, P<0.001). The 20 min enhancement degree was positively correlated with AOD value ( r=0.954, P<0.001). The positive expression rate of α-SMA, collagen fiber coverage and vascular long/short diameter were negatively correlated with 20 min enhancement rate ( r=-0.901, P<0.001; r=-0.837, P=0.005; r=-0.880, P=0.002). The results of multiple linear stepwise regression analysis showed that the positive expression rate of α-SMA was an important influencing factor for the 20 min enhancement rate (R 2=0.813, P=0.001). Conclusions:The increase of fibroblast implantation ratio significantly decreased the permeation efficiency of tumor tissue. The positive expression rate of α-SMA, the coverage rate of collagen fibers and the long/short diameter of blood vessels were negatively correlated with the permeation efficiency of tumor tissue. The 20 min enhancement degree was positively correlated with tissue permeation efficiency.

Objective To evaluate the advantages of sevoflurane inhalation anesthesia combined with lumbosacral plexus block for hip replacement in elderly patients. Methods Sixty patients of both se-xes, aged 65-85 yr, with body mass index of 18-25 kg∕m2, of American Society of Anesthesiologists physical statusⅠ-Ⅲ, scheduled for elective unilateral hip replacement, were divided into 2 groups(n=30 each)using a random number table: total intravenous anesthesia group(TIVA group)and GasMan software-guided sevoflurane inhalation anesthesia combined with lumbosacral plexus block group(SEV-B group). After the laryngeal mask airway was inserted, the patients were mechanically ventilated in both groups. Heart rate and mean arterial pressure(MAP)were recorded before anesthesia(T0), immediate-ly after insertion of laryngeal mask airway(T1), immediately after skin incision(T2), immediately after intramedullary reaming(T3), immediately after prosthesis implanting(T4), at the end of surgery(T5) and at 5 min after removal of the laryngeal mask airway(T6). The end-tidal concentration of sevoflurane at T2-5was also recorded in group SEV-B. The time for removal of the laryngeal mask airway, duration of stay in post-anesthesia care unit and first ambulation time were recorded. The consumption of anesthetics used during patient-controlled intravenous analgesia(PCIA), effective pressing times of PCIA, requirement for rescue analgesic and adverse reactions were also recorded at 24 h after surgery. The patient′s cognitive func-tion was assessed using Mini-Mental State Examination at 1 day before surgery and 1 and 3 days after surger-y, and the occurrence of postoperative cognitive dysfunction was recorded. Results Compared with group TIVA, heart rate at T1-6and MAP at T2-6were significantly decreased, and MAP at T1was increased in group SEV-B, and the time for removal of the laryngeal mask airway, duration of stay in post-anesthesia care unit and first ambulation time were significantly shortened, the consumption of anesthetics used during PCIA, effective pressing times of PCIA, requirement for rescue analgesic and incidence of adverse reac-tions were reduced at 24 h after surgery, the Mini-Mental State Examination scores were increased at 1 day after surgery, and the incidence of postoperative cognitive dysfunction was decreased at 1 day after surgery in group SEV-B(P<005). Conclusion GasMan software-guided sevoflurane inhalation anesthesia com-bined with lumbosacral plexus block can provide more accurate anesthesia management for hip replacement and promote rapid rehabilitation after surgery in elderly patients.

Objective : The purpose of this study was to investigate the effects of plasma exosome⁃derived miR⁃29b⁃3p in myocardial ischemia⁃reperfusion injury ( MIRI) rats on hypoxia/reoxygenation ( H/R) cardiomyocyte after sevoflurane (SEV) postconditioning through targeting IGF1 . Methods : The GEO database was used to screen differentially expressed miRNAs in MIRI , and cardiomyocytes were treated with H/R to construct a MIRI cell model. The expression of miR⁃29b⁃3p and IGF1 in the MIRI cell model post⁃treated with SEV was intervened , and then the survival rate of cardiomyocytes was detected by MTT , apoptosis was detected by flow cytometry , and inflammatory factors (IL⁃1β and TNF⁃α ) in cardiomyocytes in each group were detected by ELISA. Results : Compared with Normal group , the expression of miR⁃29b⁃3p in plasma exosomes of MIRI rats was enhanced (P < 0. 05) , and the target⁃binding relationship between miR⁃29b⁃3p and IGF1 was confirmed ( P < 0. 05) . After SEV post⁃treatment , the expression of miR⁃29b⁃3p in H/R⁃stimulated cardiomyocytes decreased , while the expression of IGF1 increased (both P < 0. 05) . Overexpression of miR⁃29b⁃3p in plasma exosomes could significantly inhibit the survival rate of H/R cells after SEV treatment , aggravate apoptosis and inflammatory response , while knockdown of miR⁃29b⁃3p showed a opposite effects (all P < 0. 05) . The rescue experimental data showed that overexpression of IGF1 could partially reverse the effects of overexpression of miR⁃29b⁃3p on H/R cell injury after SEV treatment ( all P <0. 05) . Conclusion Plasma exosome⁃derived miR⁃29b⁃3p promotes H/R cardiomyocyte injury after SEV treatment by targeting IGF1 .