Objective To compare the effects of different doses of dexmedetomidine on the median effective concentration (EC50) of ropivacaine for epidural block and investigate the appropriate dose.Methods One hundred and twenty ASA Ⅰ patients of both sexes,aged 20-55 yr,weighing 50-75 kg,scheduled for knee arthroscopic operation,were randomly divided into 4 groups (n =30 each):no dexmedetomidine group (group D0),0.25 μg/kg dexmedetomidine group (group D0.25),0.50μg/kg dexmedetomidine group (group D0.50),and 1.00μg/kg dexmedetomidine group (group D1.00).In group D0,ropivacaine 20 ml was injected into epidural space.The ropivacaine-dexmedetomidine mixtures containing 0.25,0.50 and 1.00 μg/kg dexmedetomidine were injected into epidural space in groups D0.25,D1.00 and D0.50 respectively.The volume of mixtures was 20 nl in groups D0.25,D1.00 and D0.50.The initial concentration of ropivacaine was set at 0.40 ％,0.40 ％,0.28 ％ and 0.20 ％ in groups D0,D0.25,D0.50 and D1.00 respectively and then the EC50 was determined by up-and-down technique.The concentration of ropivacaine was increased/decreased by 0.02％ in the next patient.The analgesic effect was assessed using VAS score.VAS score =0 was considered as effective analgesia.The EC50 and 95％ confidence interval (CI) of ropivacaine were calculated using probit method.Adverse effects were recorded.Results The EC50 and 95 ％ CI of ropivacaine was 0.38％ (0.35-0.41)％,0.34％ (0.31-0.36)％,0.22％ (0.20-0.24)％ and 0.14％ (0.12-0.15) ％ in groups D0,D0.25,D0.50 and D1.00 respectively.The EC50 of ropivacaine was decreased gradually in groups D0,D0.25,D0.50 and D1.00 ( P ＜ 0.05).Compared with group D0,the incidonce of hypotension and bradycardia was significantly increased in group D1.00 ( P ＜ 0.05),while no significant change was found in the incidence of adverse effects in groups D0.25 and D0.50 (P ＞ 0.05).Conclusion The appropriate dose of dexmedetomidine for epidural analgesia is 0.50 μg/kg.

Objective To investigate the effect of high-frequency oscillatory ventilation (HFOV) on inflammatory responses in lung tissues of dogs with severe acute respiratory distress syndrome (ARDS).Methods Healthy mongrel dogs of both sexes,weighing 13.7-16.2 kg,in which severe ARDS was induced by intravenous infusion of the mixture of oleic acid 0.2 ml/kg and autologous blood (equal to the volume of oleic acid).Twenty-four dogs with severe ARDS were randomly divided into 4 groups (n=6 each) using a random number table:conventional mechanical ventilation with low tidal volume group (group CMV),HFOV-9 Hz group,HFOV-12 Hz group and HFOV-15 Hz group.In HFOV-9 Hz,HFOV-12 Hz and HFOV-15 Hz groups,the frequency was 9,12,and 15 Hz,respectively,mean airway pressure 20 cmH2O,oscillation pressure 70 cmH2O,and inspired oxygen fraction ratio 1.0.In group CMV,the animals were mechanically ventilated in volume-controlled mode,with positive end-expiratory pressure 5 cmH2O,tidal volume 6 ml/kg,respiratory rate 30 breaths/min,inspiratory/expiratory ratio 1:2,and inspired oxygen fraction ratio 1.0.At 4 h of ventilation,the animals were sacrificed,and lungs were removed for determination of wet/dry weight (W/D) ratio,contents of tumor necrosis factor-alpha (TNF-α),interleukin-6 (IL-6) and IL-10 (by enzyme-linked immunosorbent assay),and expression of vascular endothelial (VE)-Cadherin (by Western blot) and for microscopic examination.Lung injury scores were assessed.Results Compared with group CMV,the lung injury scores,W/D ratio,and contents of TNF-α and IL-6 were significantly decreased,the content of IL-10 was significantly increased,and the expression of VE-Cadherin was significantly up-regulated in the other three groups (P＜0.05).Compared with group HFOV-9Hz,the lung injury scores,W/D ratio and contents of TNF-α and IL-6 were significantly decreased,the content of IL-10 was significantly increased,and the expression of VE-Cadherin was significantly up-regulated in group HFOV-15 Hz,and the content of IL-6 was significantly decreased in group HFOV-12 Hz (P＜0.05).Conclusion HFOV can significantly inhibit inflammatory responses in lung tissues of dogs with severe ARDS as compared with mechanical ventilation with low tidal volume,which may be involved in the mechanism of lung-protective ventilation effect.

Objective To approach the effect of Shenfu injection (SFI) and conventional early goal-directed therapy (EGDT) on organ functions and outcomes of septic shock patients. Methods Eighty-four cases conformed to the criteria for the diagnosis of septic shock admitted to Department of Critical Care Medicine of Xuzhou Central Hospital were randomly divided into conventional treatment group (42 cases), and SFI treatment group (42 cases). Conventional treatment was given in the two groups;in SFI treatment group, SFI 100 mL was additionally given by trace continuous intravenous pump 20 mL/h, twice daily for 7 days. Before and after treatment for 1, 6, 12, 24, 48, 72 hours, the levels of hemodynamic status, lactic acid and dosage of vasoactive drugs used, organ function, acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score, sequential organ failure assessment (SOFA) score, the time of weaning from ventilator, the length of stay in intensive care unit (ICU), time without organ failure and 28-day mortality rate were observed. Results Compared with those before treatment, after treatment in the two groups, the mean arterial pressure (MAP), cardiac index (CI) and systemic vascular resistance index (SVRI) were increased, while the levels of heart rate (HR) and lactate were decreased (all P<0.05). Compared with conventional treatment group, in SFI treatment group, after treatment for 24 hours, the MAP level was increased significantly [mmHg (1 mmHg=0.133 kPa):75.40±9.75 vs. 71.80±11.08, P < 0.05], that continued to 48 hours; after treatment for 6 hours, the CI level was increased obviously (mL·s-1·m-2: 75.18±34.84 vs. 67.35±39.34, P < 0.05) , that continued to 48 hours; after treatment for 6 hours, the lactic acid level was decreased markedly (mmol/L: 2.03±0.82 vs. 2.24±0.97, P < 0.05);in the comparison of dosage of vasoactive drugs used between two groups, the difference was not significant (all P >0.05). Compared with that before treatment, in the conventional treatment group after treatment for 1 and 3 days, gamma glutamyl transpeptidase (GGT) was increased, on the 5th day it began to decrease, reaching its minimum on the 7th day (U/L:26.75±16.74 vs. 46.96±25.85);while in SFI treatment group, GGT was increased after treatment for 1 day, on 3rd day it began to decrease, reaching its lowest level on the 7th day (U/L:22.41±17.87 vs. 51.23±27.74);aspartate aminotransferase (AST), total bilirubin (TBil), oxygenation index (PaO2/FiO2) were increased after the treatment for 1, 3, 5, 7 days, and blood urea nitrogen (BUN), creatinine (Cr) were decreased at different time points after treatment. In the conventional treatment group, the precursor protein (PA) was decreased after treatment for 1, 3, 5 days, on the 7th day it was increased (mg/L:134.20±63.44 vs. 115.70±45.96);while in SFI treatment group, after the treatment for 1 days and 3 days, it was decreased, on the 5th day it was increased, reaching its highest level on the 7th day (mg/L:145.40±59.75 vs. 108.20±54.34). Compared with those before treatment, after treatment for 1, 3, 5, 7 days, APACHEⅡscore and SOFA score were decreased in the two groups, but there was no statistically significant difference in APACHEⅡscore between the two groups, in SFI treatment group after treatment for 3 days, SOFA score was significantly lower than that of the conventional treatment group (6.31±3.86 vs. 7.14±4.03, P<0.05), that continued to the 7th day after treatment. In SFI treatment group, the time for weaning from ventilator (days:7.5±3.5 vs. 9.1±3.2) and the length of stay in ICU (days: 16.1±9.2 vs. 18.7±8.3) were significantly shorter than those in conventional treatment group (both P<0.05). There were no significant differences in time without organ failure (days:14.5±4.2 vs. 15.3±3.1) and 28-day mortality rate [28.6%(12/42) vs. 31.0%(13/42)] between SFI group and conventional group (both P>0.05). Conclusion The combined use of SFI and EGDT can improve hemodynamics, reduce damage to vital organs, and shorten the times for ventilation and stay in ICU in septic shock patients.

Objective To evaluate the role of endoplasmic reticulum stress in ketamine-induced apoptosis in rat neurons.Methods Rat adrenal pheochromocytoma cell line (PC12 cells) was seeded in the culture dishes 100 mm in diameter (10 ml/dish) or in 6-well plates (2 ml/well) at a density of 5 × 105 cells/ml.PC12 cells were divided into 4 groups (n =6 each) using a random number table:control group (group C);ketamine group (group K);endoplasmic reticulum stress inhibitor salubrinal group (group S);ketamine + salubrinal group (group K+S).In group C,the cells were cultured in the plain culture medium.In group K,1.5 mmol/L ketamine was added.In group S,30 mmol/L salubrinal was added.In group K + S,1.5 mmol/L ketamine and 30 mmol/L salubrinal were added.At 24 h of incubation,the cell morphology was observed under light microscope,the expression of Bip and caspase-12 in PC12 cells was detected by Western blot,and the cell apoptosis was measured by flow cytometry.The apoptosis rate was calculated.Results Compared with group C,the expression of Bip and caspase-12 was significantly upregulated,and the apoptosis rate was increased in K and K + S groups (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group S (P＞ 0.05).Compared with group K,the expression of Bip and caspase-12 was significantly down-regulated,and the apoptosis rate was decreased in group K+S (P＜0.05).The degree of damage to PC12 cells was more serious in group K than in group C..The degree of damage to PC12 cells in group K+S was significantly mnilder than that in group K and more serious than that in group C.Conclusion The mechanism by which ketamine induces neuronal apoptosis is related to the enhancement of endoplasmic reticulum stress in rats.

BACKGROUND:Elderly hypertensive patients often associated with organ and tissue ischemia. Al kinds of risks are easy to appear in the process of undergoing arthroplasty. To ensure the smooth operation and to improve the safety of the surgery treatment, it is needed to choose an appropriate mode of anesthesia.
OBJECTIVE:To explore the application security of epidural combined with smal dose of intravenous anesthesia in total knee arthroplasty in elderly hypertensive patients.
METHODS:A total of 64 elderly hypertensive patients with arthroplasty in the Third Hospital of Hebei Medical University from December 2013 to December 2014 were selected and were divided into control group (32 cases) and observation group (32 cases). They were given total intravenous anesthesia and epidural block combined with smal dose of intravenous anesthesia. Systolic blood pressure, diastolic blood pressure, heart rate, blood oxygen saturation and changes in respiratory rate were detected before anesthesia, after anesthesia induction, 10 minutes after anesthesia, 10 minutes after use of bone cement, and at the end of arthroplasty in both groups. The usage of vasoactive drugs (including ephedrine and dopamine) during arthroplasty and adverse events after arthroplasty were recorded. RESULTS AND CONCLUSION:Compared with pre-anesthesia, systolic blood pressure and diastolic blood pressure were significantly reduced and blood oxygen saturation was increased at 10 minutes after anesthesia and 10 minutes after the application of bone cement in both groups (P<0.05). In the end of arthroplasty, systolic blood pressure, diastolic blood pressure and respiratory rate were significantly higher in the control group than in the observation group (P<0.05). A total of 3 cases in the observation group and 15 cases in the control group used vasoactive drugs (including ephedrine and dopamine), and there was a significant difference in its usage (P<0.05). Moreover, five patients in the control group experienced respiratory insufficiency, which was apparently improved after given the short-term ventilator support. These results confirm that compared with the total intravenous anesthesia, epidural block combined with smal dose of intravenous anesthesia showed a high safety during total knee arthroplasty in elderly hypertensive patients.

Objective:To evaluate the retinal differentiation ability of human induced pluripotent stem cells (hiPSCs) from various somatic cell sources.Methods:The hiPSCs lines BC1- green fluorescent protein (GFP) and Gibco obtained by blood cell reprogramming and the hiPSCs line UE017 obtained by urine cell reprogramming were used to induce retinal differentiation.The morphogenesis and development of retina were recorded with an optical microscope, and the expression of specific molecular markers of various cell subclasses in the retina was detected by immunofluorescence, and the efficiency of retinal differentiation of different cell lines was analyzed and compared.Results:All three hiPSC lines derived from blood and urine cells were able to be induced into three-dimensional (3D) retinal organoids, including neuroretina and retinal pigment epithelial cells.Retinal organoids simulated the development process of retina in vivo and gradually differentiated into all cell subtypes of retina, including retinal ganglion cells, photoreceptor cells, amacrine cells, horizontal cells, bipolar cells, Müller cells, and even formed lamellar structures.However, in terms of the efficiency of acquiring retinal organoids, the hiPSCs derived from blood were more efficient than those derived from urine. Conclusions:hiPSCs from both blood and urine somatic cells can differentiate into 3D retinal organoids, including all subtypes of retinal cells.The differentiation efficiency among lines is different.