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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.
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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.
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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.