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To investigate the clinical efficacy and safety of Wei nasal jet tube (WNJT) in painless gastroscopy in patients over age of 60, 80 patients aged 60 years or older scheduled for gastroscopy under propofol mono-sedation in Beijing Friendship Hospital were divided into WNJT group ( n=40) and nasal cannula group ( n=40) according to the random number table method from January to June 2021. The main observation indicator was the difference in the incidence of hypoxemia between the two groups, the secondary observation indicators included the lowest pulse blood oxygen saturation (SpO 2), interventions related to hypoxemia, adverse events such as body movement, cough, epistaxis, sore throat, and the satisfaction of physicians, anesthetists and patients. The results showed that the procedure time and total dosage of propofol were no significant differences between the two groups ( P>0.05). Compared with the nasal cannula group, the incidence of hypoxemia in the WNJT group was significantly lower [2.5% (1/40) VS 25.0% (10/40), χ2=8.538, P=0.003], the lowest SpO 2 was significantly higher (97.7%±2.5% VS 92.6%±5.8%, t=5.093, P<0.001), and the use of jaw lift was reduced [5.0% (2/40) VS 35.0% (14/40), χ2=11.250, P=0.001]. The adverse events were not significantly different between the two groups ( P>0.05), but no case of epistaxis and sore throat occurred in the nasal cannula group. The two groups were comparable in terms of the satisfaction of patients, anesthetists and physicians ( P>0.05). In conclusion, WNJT can be used safely during gastroscopy with propofol mono-sedation in patients over 60 years old, with less incidence of hypoxemia and the number of airway interventions. But violent operation should be avoided to reduce the incidence of epistaxis and sore throat.
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Objective:To assess the influence of age on the safety of propofol mono-sedation for adult patients undergoing painless gastroscopy.Methods:A retrospective study was conducted on data of 321 patients scheduled for painless gastroscopy with propofol mono-sedation. According to the age, patients were divided into youth group (116 cases, 18-44 years), middle-aged group (103 cases, 45-59 years) and elderly group (102 cases, 60-80 years). The procedure time, the total dosage of propofol, the occurrence of airway obstruction or hypoxemia, the use of airway interventions including airway opening maneuvers and facemask ventilation, lowest SpO 2, adverse cardiovascular events (including hypertension, hypotension, tachycardia, and bradycardia), and the use of ephedrine during painless gastroscopy were observed. Results:There was significant difference regarding the total dosage of propofol among youth group (173.2±47.0 mg), middle-aged group (158.8±41.3 mg) and elderly group (137.8±26.3 mg) ( F=21.761, P<0.001). The total dosage of propofol was significantly lower in the elderly group compared with the middle-aged group ( P<0.017) and youth group ( P<0.017), and that in the middle-aged group was significantly lower than that in the youth group ( P<0.017). The incidence of hypoxemia was 12.9% (15/116) in the youth group, 15.5% (16/103) in the middle-aged group and 25.5% (26/102) in the elderly group, with significant difference among three groups ( χ2=5.711, P=0.017). Moreover, the incidence of hypoxemia was significantly higher in the elderly group compared with the middle-aged group ( P<0.017) and youth group ( P<0.017). The incidences of hypotension, bradycardia and total adverse cardiovascular events were 5.2% (6/116), 4.9% (5/103) and 11.8% (12/102), 1.7% (2/116), 2.9% (3/103) and 7.8% (8/102), and 11.2% (13/116), 10.7% (11/103) and 20.6% (21/102) respectively in youth, the middle-aged and the elderly group. There were no significant differences in the above indicators among the three groups ( P>0.05). However, compared with those of the young and the middle-aged patients, the occurrence of hypotension, bradycardia and total adverse cardiovascular events in the elderly patients were on the rise. There were no significant differences among the three groups in other indices( P>0.05). Conclusion:Total dosage of propofol may need to be decreased gradually with the increase of age of patients undergoing gastroscopy with propofol mono-sedation. Compared with young and middle-aged patients, elderly patients have a significantly higher incidence of hypoxemia, with a tendancy of total adverse cardiovascular events increase, so the safety of painless gastroscopy is reduced for these patients.
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Objective:To evaluate left lateral position I-scope tracheal intubation for optimizing anesthesia time during the patient′s general anesthesia before endoscopic submucosal dissection.Methods:A total of 150 patients with early upper gastrointestinal cancer were enrolled in the study for endoscopic submucosal dissection in Beijing Friendship Hospital, Capital Medical University from March to December 2018. Patients were randomly divided into three groups with 50 patients in each group. The SL group underwent I-scope tracheal intubation in the left lateral position, SS group underwent I-scope tracheal intubation in the supine position, and MS group underwent Macintosh laryngoscope tracheal intubation in the supine position. Preoperative non-essential anesthesia time (the time between successful intubation and operation), attempts for tracheal intubation and complications related to intubation were analyzed.Results:The preoperative non-essential anesthesia time was 8.55±2.16 min in SL group, 10.44±2.43 min in SS group, and 10.56±3.20 min in MS group, with significant difference among three groups ( F=9.08, P<0.001), and the time in SL group was shorter than that in SS group ( P<0.001) and MS group ( P<0.001). However, there was no statistical difference in non-essential anesthesia time between the SS group and MS group ( P=0.819). The success rate of first attempt intubation was 96.0% (48/50) in SL group, 90.0% (45/50) in SS group, and 92.0% (46/50) in MS group, with no significant differences among three groups ( χ2=2.601, P=0.627). The incidences of cough and expectoration, dry mouth and mucosal injury showed no statistical differences among three groups during transference to the ward after tracheal catheter removal (all P>0.05). The incidence of sore throat in MS group (38.0%, 19/50) was higher than that in SL group (18.0%, 9/50, P<0.05) and SS group (18.0%, 9/50, P<0.05), while the difference was not statistically significant between SL group and SS group ( P>0.05). Conclusion:I-scope tracheal intubation in the left lateral position may shorten the preoperative anesthesia time in patients undergoing general anesthesia for the operation in the left lateral position, and optimize overall anesthesia time.
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Objective To evaluate the relationship between the mechanism underlying inhibition of inflammatory responses induced by α7 nicotinic acetylcholine receptor(α7nAChR)agonist postcondition?ing alone or in combination with remote limb ischemic postconditioning during myocardial ischemia?reperfu?sion(I∕R)and glycogen synthase kinase?3β(GSK?3β)in rats. Methods Eighty adult male Sprague?Dawley rats, aged 8 weeks, weighing 290-320 g, were divided into 4 groups(n=20 each)using a ran?dom number table: I∕R group, α7nAChR agonist postconditioning group(group P), remote limb ische?mic postconditioning group(group L)and α7nAChR agonist postconditioning plus remote limb ischemic postconditioning group(group P+L). Myocardial I∕R was induced by 30 min occlusion of the left anterior descending branch of coronary artery followed by 120 min reperfusion. Specific α7nAChR agonist PNU282987 2 mg∕kg was intravenously injected immediately before reperfusion in group P. In group L, limb ischemia was induced by tourniquet occlusion of bilateral hind paws for 10 min starting from 20 min of myocardial ischemia, and the tourniquet was released at the beginning of reperfusion. Combination of inter?vention measures previously described in P and L groups was performed in group P+L. Venous blood sam?ples were taken at 120 min of reperfusion for determination of serum troponin I(TnI)and creatine kinase?MB(CK?MB)concentrations, myocardial infarct size(IS)and expression of phosphorylated GSK?3β [p?GSK?3β(Ser536)], NF?κBp65 and phosphorylated nuclear factor?κBp65(p?NF?κBp65)in myocar?dial tissues(by Western blot). Results Compared with group I∕R, myocardial IS and serum cTnI and CK?MB concentrations were significantly decreased, the expression of p?GSK?3β(Ser9)in ischemic area was up?regulated, and the expression of p?NF?κBp65 in ischemic area was down?regulated in P, L and P+L groups(P<0.05). Compared with group L, myocardial IS and serum cTnI and CK?MB concentrations were significantly decreased, the expression of p?GSK?3β(Ser9)in ischemic area was up?regulated, and the expression of p?NF?κBp65 in ischemic area was down?regulated in group P+L(P<0.05). Conclusion The mechanism by which α7nAChR agonist postconditioning alone or in combination with remote limb is?chemic postconditioning inhibits inflammatory responses during myocardial I∕R may be related to inhibiting GSK?3β activity in rats.
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Objective To evaluate the relationship between autophagy and diabetes mellitus-caused influence on ischemic preconditioning ( IP )-induced cardioprotection in rats. Methods Clean-grade healthy male Sprague-Dawley rats, aged 12 weeks, weighing 290-320 g, were used in this study. Diabe-tes mellitus was induced by high-fat and high-sucrose diet ( lasting for 1 week) and intraperitoneal streptozo-tocin 50 mg∕kg ( for 2 consecutive days) and confirmed by fasting blood glucose level≥16. 65 mmol∕L ( for 1 week) . Thirty rats with diabetes mellitus, weighing 350-450 g, were divided into 3 groups ( n=10 each) using a random number table method: sham operation group ( DM-S group) , myocardial ischemia-reperfusion ( I∕R) group ( DM-IR group) and IP group ( DM-IP group) . Another 30 non-diabetic rats were selected and divided into 3 groups ( n=10 each ) using a random number table method: sham operation group (S group), myocardial I∕R group (IR group) and IP group. Myocardial ischemia was induced by ligation of the anterior descending branch of left coronary artery for 30 min followed by 120 min reperfusion. IP was produced by 3 cycles of 5-min ischemia followed by 5-min reperfusion prior to establishment of myo-cardial I∕R injury model in IP and DM-IP groups. Blood samples were collected from the internal jugular vein at the end of reperfusion for measuring serum concentrations of cardiac troponin I ( cTnI) and creatine kinase-MB ( CK-MB) . The rats were then sacrificed and myocardial tissues were obtained for determination of myocardial infarct size and expression of microtubule-associated protein 1 light chain 3 Ⅱ ( LC3 Ⅱ) , Beclin-1, phosphatidyl-inositol 3-kinase (PI3K), protein kinase B (Akt), phosphorylated Akt (p-Akt) and mammalian target of rapamycin ( mTOR) ( by Western blot) . p-Akt∕Akt ratio was calculated. Results Compared with S group, the serum cTnI and CK-MB concentrations were significantly increased, the percentage of myocardial infarct size was increased, the expression of LC3Ⅱand Beclin-1 in myocardial tis-sues was up-regulated, the expression of PI3K and mTOR was down-regulated, and p-Akt∕Akt ratio was decreased in IR group (P<0. 05). Compared with IR group, the serum cTnI and CK-MB concentrations were significantly decreased, the percentage of myocardial infarct size was decreased, the expression of LC3Ⅱand Beclin-1 in myocardial tissues was down-regulated, the expression of PI3K and mTOR was up-regulated, and p-Akt∕Akt ratio was increased in IP group ( P<0. 05) . Compared with DM-S group, the se-rum cTnI and CK-MB concentrations were significantly increased, the percentage of myocardial infarct size was increased, the expression of LC3Ⅱ and Beclin-1 in myocardial tissues was up-regulated, the expres-sion of PI3K and mTOR was down-regulated, and p-Akt∕Akt ratio was decreased in DM-IR group ( P<0. 05) . There was no significant difference in the parameters mentioned above between DM-IP group and DM-IR group (P>0. 05). Conclusion The mechanism by which diabetes mellitus abolishes IP-induced cardioprotection may be related to inhibiting activation of PI3K-Akt-mTOR signaling pathway and enhanced autophagy in rats.
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Objective To evaluate the role of the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)or Janus kinase(JAK)/signal transducer and activator of transcription 3(STAT-3)signaling pathways in reduction of myocardial ischemia-reperfusion(I/R)injury by combination of limb ischemic and morphine postconditioning in rats.Methods Eighty SPF healthy male Sprague-Dawley rats,aged 8 weeks,weighing 280-320 g,were used in the study.Myocardial I/R was induced by occlusion of the left anterior descending branch of the coronary artery for 30 min followed by 120 min reperfusion.The rats were divided into 8 groups(n=10 each)using a random number table:I/R group,limb ischemic postconditioning group(LIP group),morphine postconditioning group(group MP),combination of limb ischemic and morphine postconditioning group(LIP+MP group)and signaling pathway blocker groups(I/Rb group,LIPb group,MPb group,LIP+MPb group).In I/R,LIP,MP and LIP+MP groups,the animals were sacrificed at the end of reperfusion,and myocardial specimens in ischemic and non-ischemic regions were obtained for determination of phosphorylated STAT-3(p-STAT-3),STAT-3,phosphorylated Akt(p-Akt)and Akt expression(by Western blot)and STAT-3 and Akt mRNA expression(by polymerase chain reaction).In I/Rb,LIPb,MPb and LIP+MPb groups,PI3K/Akt signaling pathway blocker LY294002 0.3 mg/kg was intravenously injected in 5 rats of each group,and JAK/STAT-3 signaling pathway blocker AG490 5 mg/kg was intravenously injected in the other 5 rats of each group.The animals were sacrificed at the end of reperfusion,and myocardial specimens in the ischemic region were obtained for determination of myocardial infarct size.Results Compared with I/R group,the p-STAT-3/STAT-3 ratio in LIP,MP and LIP+MP groups and p-Akt/Akt ratio in LIP+MP group were significantly increased,and the expression of STAT-3 and Akt mRNA was up-regulated in LIP+MP group(P0.05).When JAK2 inhibitor AG490 was applied,the myocardial infarct size was significantly smaller in LIP+MPb group than in I/Rb,LIPb and MPb groups(P0.05).Conclusion Combination of limb ischemic and morphine postconditioning can enhance the activation of PI3K/Akt or JAK/STAT-3 signaling pathways,and the cardioprotection is dependent on the integrity of the PI3K/Akt signaling pathway and partially dependent on the integrity of the JAK/STAT-3 signaling pathway when applied in combination in rats.
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Objective To investigate the role of reactive oxygen species (ROS) in the reduction of myocardial ischemia-reperfusion (I/R) injury by fentanyl postconditioning and remote limb ischemic postconditioning in rats.Methods Sixty-three male Sprague-Dawley rats,aged 8 weeks,weighing 250-350 g,were equally and randomly allocated into 7 groups:sham operation group (group S),group I/R,fentanyl postconditioning group (group F),remote limb ischemic postconditioning group (group R),ROS scavenger N-(2-Mercaptopropionyl) glycine (MPG) group (group M),MPG + fentanyl postconditioning group (group MF),and MPG + remote limb ischemic postconditioning group (group MR).Myocardial I/R was induced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 180 min of reperfusion.In group S the anterior descending branch was only exposed but not ligated.MPG 5 mg/kg was infused intravenously from 5 min before ischemia to 15 min of reperfusion in groups M,MF and MR,while the equal volume of normal saline was given in the other four groups.In groups F and MF,fentanyl 30 μg/kg was injected intravenously at 15 min of myocardial ischemia.In groups R and MR,the animals underwent 10 min ischemia of bilateral hind limbs starting from 15 min of myocardial ischemia.Arterial blood samples were taken at 180 min of reperfusion to determine the serum cardiac troponin I (cTnI) concentration.The rats were then sacrificed.The infarct size was measured by TTC.Results Compared with group S,the serum cTnI concentration and infarct size were significantly increased in the other six groups (P ＜0.05).Compared with group I/R,no significant change was found in the serum cTnI concentration and infarct size in M group,and the serum cTnI concentration and infarct size were significantly decreased in F and R groups (P ＜ 0.05).There was no significant difference in the serum cTnI concentration and infarct size between MF group and F group (P ＞ 0.05).The serum cTnI concentration was significantly higher and the infarct size was larger in group MR than in group R (P ＜ 0.05).Conclusion ROS is involved in the reduction of myocardial I/R injury by remote limb ischemic postconditioning in rats,but not in the myocardial protection provided by fentanyl postconditioning.
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Objective To evaluate the roles of PI3K/Akt and JAK/STAT signal transduction pathways in reduction of myocardial ischemia/reperfusion (I/R) injury by postconditioning with α subunit-containing nicotinic acetylcholine receptor (α7nAChR) agonist in rats.Methods Sixty Sprague-Dawley rats,weighing 290-320 g,were randomly divided into 4 groups (n =15 each):I/R group,ischemic preconditioning group (IPC group),ischemic postconditioning group (IPOC group) and postconditioning with specific α7nAChR agonist PNU282987 group ( PNU group ).Myocardial I/R was produced by 30 min occlusion of left anterior descending coronary artery followed by 180 min reperfusion in the 4 groups.The animals were subjected to 3 cycles of 5 min myocardial ischemia and 5 min reperfusion before 30 min myocardial ischemia in IPC group.The animals underwent 3 cycles of 10 s myocardial ischemia at 5 s intervals before 180 min reperfusion in group IPOC.PNU282987 2.4 mg/kg was injected intraperitoneally immediately before the reperfusion.At 60 min of reperfusion,5 rats in each group were sacrificed and the hearts were removed to determine the expression of Akt and STAT3 mRNA,phosphorylated Akt (p-Akt) and phosphorylated STAT3 (p-STAT3) in myocardial tissues.The left 10 rats in each group were sacrificed at 180 min of reperfusion and the hearts were removed to measure the infarct size.Results Compared with I/R group,the expression of STAT3 mRNA and p-Akt was significantly up-regulated in IPC group,and the expression of p-Akt and p-STAT3 was significantly up-regulated in IPOC group ( P ＜ 0.05).The infarct size was significantly reduced in IPC,IPOC and PNU groups compared with I/R group ( P ＜ 0.05 ).Conclusion The mechanism by which α7nAChR agonist postconditioning reduces myocardial I/R injury is not related to PI3K/Akt and JAK/STAT signal transduction pathways in rats.
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ObjectiveTo evaluate the effects of combined vagus nerve electric stimulation postconditioning and limb remote ischemic postconditioning on myocardial ischemia-reperfusion (I/R) injury in rats.Methods One hundred male SD rats aged 8 weeks weighing 250-350 g were randomly allocated into 5 groups ( n =20 each):sham operation group (group S); I/R group; vagus nerve electric stimulation postconditioning group (group POES) ; limb remote ischemic postconditioning group (group RP) and vagus nerve electric stimulation postconditioning + limb remote ischemic postconditioning group (group POES-RP).Myocardial I/R was induced by occlusion of left anterior descending branch (LAD) of coronary artery for 30 min followed by 120 min reperfusion in groups I/R,POES,RP and POES-RP.In groups POES and POES-RP,right cervical vagus nerve trank was stimulated for 30 min with continuous electric rectangular pulses (2 ms,10 Hz) starting from 15 min of myocardial ischemia.The voltage of the pulses was adjusted to decrease HR by 10％ of the baseline HR before stimulation.In groups RP and POES-RP the animals underwent 10 min ischemia of bilateral hind limbs starting from 20 min of myocardial ischemia.Arterial blood samples were collected from 10 rats in each group at 120 min of reperfusion for determination of serum concentrations of cTnI,CK-MB,TNF-α,high mobility group box 1 protein (HMGB1),intercellular adhesion molecule-1(ICAM-1),IL-1,IL-6 and IL-10 (by ELISA).The animals were then sacrificed and myocardial infarct size was measured by Evans blue and TTC staining.Another 10 rats were sacrificed at 120 min of reperfusion for determination of myocardial contents of TNF-α,HMGB-1,ICAM-1,IL-1,ID6 and IL-10 (by ELISA).ResultsI/R induced myocardial infarct and significantly increased serum concentrations of cTnI,CK-MB,TNF-α,HMGBi,ICAM-1,IL-1 and IL-6 and increased myocardial contents ofTNF-α,HMGB1,ICAM-1,IL-1,IL-6 and IL-10 in both ischemic and non-ischemic regions in group I/R as compared with group S.Vagus nerve electric stimulation postconditioning,limb remote ischemic postconditioning and vagus nerve electric stimulation postconditioning + limb remote ischemic postconditioning significantly decreased myocardial infarct size and serum concentrations of cTnI,CK-MB,TNF-α,HMGB1,ICAM-1,IL-1 and IL-6 and decreased myocardial contents of TNF-α,HMGB1,ICAM-1,IL-1,IL-6 in groups POES,RP and POES-RP as compared with group I/R.Compared with group I/R,myocardial IL-10 content in both ischemic and non-ischemic regions was significantly increased in groups POES and POES-RP.Compmared with group POES,myocardial infarct size,serum concentrations of cTnI,CK-MB,TNF-α,ICAM-1 and myocardial contents of ICAM-1 and IL-6 in ischemic region were significantly decreased,while myocardial content of IL-10 in non-ischemic region was increased in group POES-RP.Compared with group RP,myocardial infarct size,serum concenuations of cTnI,CK-MB,TNF-α,HMGB1,ICAM-1,IL-1,IL-6 and myocardial contents of TNF-α,ICAM-1,IL-1 and IL-6 in ischemic region were significantly decreased,myocardial content of IL-10 in ischemic region was increased and HMGB1,ICAM-1,IL-1 and IL-6 contents were decreased,IL-10 content was increased in myocardial of ischemic region in group POES-RP.ConclusionMyocardial I/R injury is attenuated and myocardial protection is enhanced by combination of vagus nerve electric stimulation postconditioning and limb remote ischemic postconditioning in rats by inhibiting inflammatory response in rats.
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Objective To investigate the effects of preconditioning with different doses of levothyroxine sodium on myocardial ischemia-reperfusion (I/R) injury in immature rats. Methods Forty-eight female immature Wistar rats, aged 35 days, weighing 120-140 g, were randomly allocated into 6 groups ( n = 8 each): control group (group C), I/R group, and preconditioning with levothyroxine sodium 10, 20, 40 and 80 μg/100 g groups (groups LS1-4 ) . The rats received levothyroxine sodium 10, 20, 40 and 80 μg/100 g through a gastric tube every day for 7 days in groups LS1-4 , respectively. Venous blood samples were taken on 8th day for determination of serum thyroid hormone levels. The hearts were removed from the animals and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃. The hearts were continuously perfused for 80 min in group C. After 30 min of equilibration, the isolated hearts were subjected to 20 min of ischemia followed by 30 min of reperfusion in I/R and LS1-4 groups. HR, SP and ± dp/dtmax were recorded at 20 min of perfusion and 30 min of reperfusion. The recovery rates of HR, SP and ± dp/dtmax were calculated at 30 min of reperfusion. The coronary effluent was collected at 10 min of perfusion and 15 min of reperfusion for determination of creatine kinase (CKMB) activity. The samples of ventricular myocardial tissues were taken at 30 min of reperfusion to detect the expression of heat shock protein 70 (HSP70), thyroid hormone receptor (TR) mRNA (TRa, , TRoj and TRft ) and myosin heavy chain (MHC) mRNA. Results Compared with group C, the recovery rates of HR, SP and. ± dp/dtmax were significantly decreased, the CK-MB activity was significantly increased, and MHCα mRNA expression was down-regulated in group I/R, the recovery rates of SP and ± dp/dtmax were significantly decreased, the CK-MB activity was significantly increased, and the expression of HSP70 and MHCα mRNA was up-regulated in groups LS1-4, and the serum thyroid hormone level was significantly increased and the expression of TRa, mRNA was up-regulated in groups LS2-4 ( P ＜ 0.05) . Compared with group I/R, the recovery rates of HR and ± dp/dtmax were significantly increased, the pression of HSP70 and MHCa mRNA was up-regulated, and the MHCJ3 mRNA expression was down-regulated in groups LS1-4 the CK-MB activity was significantly decreased in groups LS1-3, and the serum thyroid hormone level was significantly increased and the expression of TRα1, mRNA was up-regulated in groups LS2-4 ( P ＜ 0.05) . The serum thyroid hormone level increased gradually with the increase in the dose of levothyroxine sodium in groups LS1-4 ( P ＜ 0.05) . The CK-MB activity was significantly higher, while the HSP70 expression lower in groups LS3-4 than in groups LS1-2 (P ＜ 0.05). Conclusion Preconditioning with levothyroxine sodium 10 μg/100 g can alleviate the myocardial I/R injury in immature rats and does not lead to the increase in the level of thyroid hormone, and the up-regulation of HSP70 and MHCa mRNA expression may be involved in the mechanism.
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ObjectiveTo investigate the effects of postconditioning with electric vagal stimulation on myocardial ischemia-reperfusion (I/R) injury in rats.MethodsSixty male SD rats weighing 250-350 g were randomly divided into 3 groups (n ＝ 20 each):group sham operation (group S); group myocardial I/R (group I/R) and group electric vagal stimulation postconditioning (group POES).Myocardial I/R was induced by occlusion of left anterior descending branch of coronary artery for 30 min followed by 120 min reperfusion in groups I/R and POES.In group POES right cervical vagus nerve trunk was stimulated for 30 min with continuous electric rectangular pulses (2 ms,10 Hz) starting from 15 min of myocardial ischemia.The voltage of the pulses was adjusted to decrease HR by 10％ of the baseline HR before stimulation.MAP,HR and RPP (MAP× HR) were recorded before (baseline) and at 1 and 10 min of ischemia and 30,60 and 120 min of reperfusion.Arterial blood samples were collected from 10 rats in each group at 120 min of reperfusion for determination of serum concentrations of cTnI,CK-MB,TNF-a,high mobility group box 1 protein (HMGB1),ICAM-1,IL-1,IL-6 and IL-10 (by ELISA).The animals were then sacrificed and myocardial infarct size was measured by Evans blue and TTC staining.Another 10 rats were sacrificed at 120 min of reperfusion for determination of myocardial contents of TNF-α,HMGB1,ICAM-1,IL-1,IL-6 and IL-10 (by ELISA).ResultsI/R induced myocardial infarct,significantly increased serum concentrations of cTnI,CK-MB,TNF-α,HMGB1,ICAM-1,IL-1 and IL-6 and significantly increased myocardial contents of TNF-α,HMGB1,ICAM-1,IL-1,IL-6 and IL-10 in both ischemic and non-ischemic regions in group I/R as compared with group S.Electric vagal stimulation significantly decreased myocardial infarct size and serum concentrations of cTnI,CK-MB,TNF-α,HMGB1,1CAM-1,IL-1 and IL-6 in group POES compared with group I/R.Myocardial contents of TNF-α,HMGB1,ICAM-1,IL-1 and IL-6 were significantly decreased while myocardial IL-10 content was increased in both ischemic and non-isehemic regions in groups POES compared with group I/R.ConclusionPostconditioning with electric vagal stimulation can attenuate myocardial I/R injury by inhibiting inflammatory response in rats.
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Objective To compare the effects of ischemic preconditioning versus ischemic postconditioning on myocardial ischemia-reperfusion (I/R)-induced inflammatory response in rats. Methods Forty male SD rats weighing 290-320 g were randomly divided into 4 groups ( n = 10 each): Ⅰ group sham operatin (group S); Ⅱ group I/R; Ⅲ group ischemic preconditioning (group IPC) and Ⅳ group ischemic postconditioning (group IPOC).Myocardial I/R was induced by 30 min ligation of left anterior descending branch (LAD) of coronary artery followed by reperfusion. In group IPC myocardial I/R was preceded by 3 cycles of ischemia followed by reperfusion (each lasting 5 min) while in group IPOC 3 cycles of I/R (each lasting 10 s) was started at the end of 30 min myocardial ischemia. MAP, HR and RPP ( MAP × HR) were recorded before (baseline) and at 1 and 20 min of ischemia and 60, 120 and 180 min of reperfusion. Venous blood samples were collected at 30 and 180 min of reperfusion for determination of serum concentrations of TNF-α, IL-6, high-mobility group box 1 (HMGB1) and cTnI. The animals were sacrificed at 180 min of reperfusion and the myocardial infarct size was measured. Results Myocardial I/R significantly decreased MAP and RPP and increased myocarcial infarct size, serum concentrations of TNF-α, IL-6,HMGB1 and cTnI in group I/R as compmed with group S. Ischemic pre- and postconditioning significantly increased MAP and reduced myocardial infarct size and I/R-induced increase in serum TNF-α, HMGB1 and cTnI concentrations in group Ⅲ and Ⅳ as compared with group Ⅱ (I/R). The myocardial infarct size was significantly larger and the serum concentrations of TNF-α, IL-6 and HMGB1 were significantly higher in ischemic postconditioning group than in the preconditioning group. Conclusion Ischemic preconditioning is more effective in attenuating the myocardial I/R-induced inflammatory response than the ischemic postconditioning.
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Objective To investigate whether naloxone postconditioning could attenuate the focal cerebral ischemia-reperfusion (I/R) injury in rats. Methods Eighty-eight adult male SD nits weighing 270-330 g were randomly divided into 4 groups (n = 22 each) : group I sham operation (S); group Ⅱ I/R; group Ⅲ , Ⅳ I/R + low and high dose naloxone ( N_1, N_2). Focal cerebral I/R was produced by occlusion of right middle cerebral artery for 90 min followed by 24 h reperfusion. In group N_1, and N_2 naloxone 1 and 10 mg/kg were injected intraperitoneally at initiation of reperfusion respectively. In group I/R normal saline was injected instead of naloxone. HR, MAP and EKG were continuously monitored throughout the experiment. He neurological deficits were scored (0 = no deficit, 4 = unable to crawl, mental dysfunction) at 2 h and 24 h of reperfusion. The animals were then decapitated. The brains were immediately removed for determination of infarct size ( n = 10) and the expression of microtubule-associated protein-2 ( MAP-2) in brain tissue ( n = 6) . In the other 6 rats in each group FICT-dextran 1 ml (50 mg/ml) was injected iv at 1 min before decapitation. The cerebral plasma volume and diameter and segment length of cerebral microvessels on the I/R side were measured using laser scanning confocal microscopy (LSCM). Results Focal cerebral I/R significantly increased neurological deficit scores, induced cerebral infarct, and decreased MAP-2 expression in the brain tissue, cerebral plasma volume and the diameter and segment length of cerebral microvessels on the I/R side. Postconditioning with 10 mg/kg naloxone significantly attenuated the above-mentioned focal cerebral I/R-induced changes. Conclusion Postconditioning with naloxone can attenuate focal cerebral I/R injury in a dose-dependent manner.
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Objective To investigate the role of cyclooxygenase-2(COX-2)and mitochondrial adenosine tuiphosphate sensitive potassium channels (mito-KATP channels) in sufentanil preconditioning-induced delayed cardiopreteetion against myocardial ischemia-reperfnsion (I/R) injury in rats. Methods Seventy-two adult male Wistsr rats weighing 250-300 g were randomly divided into 6 groups ( n =12 each). Group Ⅰ,Ⅱ,Ⅲ were preconditioned with intraperitoneal (IP) normal saline (NS) 1 ml/kg while group Ⅳ,Ⅴ,Ⅵ with IP sufentanil 20 μg/kg at 24 h before myocardial ischemia. Group Ⅱ and Ⅴ were given IP NS-398 ( COX-2 inhibitor) 5 mg/kg at 30 rain before myocardial ischemla while group Ⅲ and Ⅵ were given intravenous 5-HD (mito-KATP channelblocker) 10 mg/kg at 10 min before ischemia or before being killed. Six animals in each group underwent 45 min myocardial ischemia followed by 120 min reperfusion, while the other six animals in each group were killed immediately before ischemia for determination of myocardial COX-2 expression and myocardial PGF2 and PGF1α content. Myocardial ischemia was induced by occlusion of left anterior descending branch (LAD) of coronary artety for 45 rain followed by 120 min reperfusion. MAP and HR were recorded immediately before ischemia (T0), at 15, 30, 45 rain of ischemia (T1-3) and at 30, 60, 90, 120 vain of reperfusion (T4-7). Heart rate-blood pressure product (RPP) was calculated. Arterial blood samples were obtained at T0.3 and T7 for measurement of plasma CK-MB activity. The animals were killed at the end of 120 nan reperfusion. The hearts were removed for determination of myocardial infarct area (IA) and area at risk (AAR). LA/AAR was calculated. Results There was no significant difference in HR, MAP and RPP at all time points among the 6 groups. Preconditioning with sufentanil significantly decreased plasma CK-MB activity at T3 and T7 and IA/AAR in group Ⅳ as compared with group Ⅰ.Myocardial COX-2 expression was up-regulated and PGE2 and PGF1α, contents were elevated by sufentanil preconditioning in group Ⅳ as eomared with control group (Ⅰ). In group Ⅴ and Ⅳ preconditioning with NS-398/5-HD significantly increased plasma CK-MB concentration and IS/AAB as compared with group Ⅳ, indicating involvement of COX-2 and mito-KATP channels in the sufentanil-induced delayed cardioprotection.The myocardial PGE2 and PGF1α contents were significantly reduced in group Ⅴ as compared with group Ⅳ. There was no significant difference in the myocardial COX-2 expression among group Ⅳ, Ⅴ and Ⅵ. Conclusion Both COX-2 and mito-KATP channels are involved in sufentanil preconditioning-induced delayed cardiopmtection.
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Objective To evaluate the protective effects of fentanyl postconditioning and remote limb ischemic postconditioning (RLIP) against myocardial ischemia-reperfusion (I/R) injury in rats. Methods Thirty-nine male SD rats aged 8 weeks weighing 250-350 g were randomly allocated into 5 groups: Ⅰ group sham operation (group S, n = 5); Ⅱ group I/R ( n = 7); Ⅲ group fentanyl postconditioning (group F, n= 9); Ⅳ group RLIP (group R, n = 9) and group Ⅴ fentanyl postconditioning + RLIP (group F-R, n = 9). The animals were anesthetized with intraperitoneal 3% pentobarbital 50 mg/kg, intubated and mechanically ventilated. Myocardial I/R was induced by occlusion of anterior desending branch of left coronary artery for 30 min followed by 180 min reperfusion. Fentanyl 30 μg/kg was injected iv at 15 min of myocardial ischemia in group F and F-R In group R and F-R the animals underwent 10 min ischemia of bilateral hind limbs starting from 15 min of myocardial ischemia. HR and MAP were recorded at 5,60,120 and 180 min of reperfusion and rate-pressure product( RPP, HR × MAP) were calculated. At the end of 180 min reperfusion, arterial blood samples were obtained for measurement of the activities of plasma lactate dehydrogenase (LDH) and creatine kinase isoenzyme MB (CK-MB), and the concentration of serum cardiac troponin Ⅰ (cTnI). The animals were then sacrificed. The infarct size was evaluated by double staining with Evans blue and triphenyl tetrazolium chloride. Results Myocardial I/R significantly increased plasma LDH and CK-MB activities and serum cTnI concentration and decreased HR,MAP and RPP as compared with group S.Fentanyl postconditioning and RLIP both decreased plasma CK-MB activity, serum cTnI concentration and infarct size and increased HR, MAP and RPP in group F, R and F-R as compared with group I/R. Plasma CK-MB activity,serum cTnI concentration and RPP were significantly lower and infarct size was smaller in group F-R than in group F. The infarct size was significantly smaller and MAP and RPP were higher in group F-R than in group R.Conclusion Fentanyl postconditioning can provide a myocardial protection against I/R injury. Myocardial protection is enhanced by combination of fentanyl postconditioning and RLIP.
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Objective To investigate the effects of postconditioning with α7 nicotinic acetylcholine receptor (α7nAChR) agonist and ischemia on myocardial ischemia-reperfusion (IR) injury in rats. Methods Fifty adult male SD rats weighing 290-320 g were randomly divided into 5 groups ( n = 10 each): Ⅰ sham operation group, Ⅱ IR group, Ⅲ ischemic postconditioning group, Ⅳ α7nAChR agonist postconditioning group and Ⅴpostconditioning with α7nAChR agonist and ischemia group. Myocardial I/R was induced by ligation of anterior descending branch of left coronary artery for 30 min followed by 1 80 min of reperfusion. In group] the anterior descending branch was only exposed but not ligated. In group Ⅲ the hearts were subjected to 3 episodes of 10 second ischemia at 10 second intervals at the end of 30 min ischemia before 180 min reperfusion, Intraperitoneal PNU282987 2.4 mg/kg was injected at the end of 30 min ischemia before 180 min reperfusion in group Ⅳ and Ⅴ .Blood samples were taken from right internal jugular vein at 180 min of reperfusion. Then the rats were killed and hearts removed to determine the concentrations of serum cardiac troponin-I (cTnI), TNF-α and high-mobility group box 1 (HMGB1) by ELISA. The infarction size was measured by Evans blue and triphenyltetrazolium chloride staining. Results The infarction size was significantly larger in the other groups and concentrations of serum cTrI, TNF-α and HMGB1 were significantly higher in group Ⅱ than in group Ⅰ ( P ＜ 0.05). The infarction size was significantly smaller and concentrations of serum cTnI, TNF-α and HMGBI were significantly lower in group Ⅲ, Ⅴ than in group Ⅱ (P ＜ 0.05). The infarction size was significantly smaller in group Ⅴ and concentrations of serum cTnI, TNF-α and HMGB1 were significantly lower in group Ⅳ and Ⅴ than in group Ⅲ (P ＜0.05). The infarction size was significantly smaller and concentrations of serum cTnI, TNF-α and HMGB1 were significantly lower in group Ⅴ than in group Ⅳ ( P ＜ 0.05 ). Conclusion Postconditioning with α7nAChR agonist and ischemia can reduce myocardial I/R injury and the efficacy is better than that of α7nAChR agonist postconditioning or ischemic postconditioning alone.
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Objective To evaluate the preventive efficacy of oral small-dose thyroid hormone tablet premedication for a short time on euthyroid sick syndrome (ESS) in children undergoing open heart surgery under cardiopulmonary bypass (CPB) .Methods Forty ASA Ⅰ or Ⅱ children aged 3-12 yr, weighing 10-30 kg, scheduled for elective congenital heart disease surgery under CPB, were randomly allocated into 2 groups ( n = 20 each):placebo group (group P) and thyroid hormone tablet group (group T). Group T received oral thyroid hormone tablets 0.4 mg/kg every day for 4 consecutive days before surgery, while group C were given placebo. CPB was routinely established, and mild hypothermia, moderate hemodilution and high flow perfusion were adopted. Blood samples were taken from radial veins before administration (baseline) and on 1st, 2nd and 4th day after surgery to detect the serum concentrations of triiodothyronine (T3), thyroxine (T4) and thyroid stimulating hormone (TSH).SP, DP and HR were recorded before administration, immediately after surgery, and on 1st and 2nd day after surgery. The endotracheal extubation time, length of ICU stay, application of positive inotropic agents and occurrence of ESS were recorded. Results No significant difference was found in hemodynamic parameters, endotracheal extubation time and length of ICU stay between the two groups ( P ＞ 0.05). As compared with the baseline values,the serum T3 levels on 1st, 2nd and 4th day after surgery, and the serum TSH levels on 1 st day after surgery were significantly decreased in the two groups, and the serum T4 levels were significantly decreased on 1 st day after surgery in group P ( P ＜ 0.05). The serum levels of T3 and T4 were significantly higher, the severity of postoperative ESS and the number of positive inotropic agent administration were significantly lower in group T than in group P (P ＜ 0.05 ). Conclusion Although oral small-dose thyroid hormone tablet premedication for 4 days (0.4 mg/kg per day) can reduce the severity of postoperative ESS, but it can not prevent the occurrence of ESS in children undergoing open heart surgery under CPB.
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Objective To evaluate the influence of head anteflexion on airway sealing pressure during intermittent positive pressure ventilation(IPPV) with ProSeal laryngeal mask airway (PLMA) with an esophageal vent.Methods Fifty ASA Ⅰ or Ⅱ patients (20 males and 30 females), aged 18-51 ye are, weighing 50-70 kg and scheduled for elective plastic surgery under general anesthesia, were enrolled in this study. Anesthesia was induced with fentanyl 2 μg/kg, propofol 2 μg/kg and vecuromium 0.1 mg/kg. PLMA with an esophageal vent was inserted at 2 min after intravenous vecuronium injection.The airway sealing pressure, the anatomic position of the cuff and the efficacy of positive pressure ventilation were checked in the neutral and anteflexed head positions with the cuff deflated and inflated to an intracuff pressure of 60 cm H2 O, respectively.Results The lungs were better ventilated in the head anteflexion position than in the head neutral position whether the cuff was deflated or inflated. There was no significant difference in the volume of air required to achieve an intracuff pressure of 60 cm H2O between the two head positions ( P＞ 0.05). The airway seating pressure increased from (27 ± 6) cm H2O in the head neutral position to (33 ± 6) cm H2O in the head anteflexion position, with no significant difference between them ( P＞ 0.05). The expired tidal volume and the peak inspiratory pressure during IPPV were (496 ± 81 ) ml and (14.3 ± 1.9) cm H2O respectively in the head neutral position and (496 ± 81 ) ml and ( 14.5 ± 2.1 )cm H2O respectively in the head anteflexion position.Conclusion Head anteflexion can significantly improve airway sealing but does not affect the anatomic position of the cuff.Appropriate head anteflexion is a simple and effective way to improve IPPV when the airway sealing pressure is inadequate in the head neutral position.
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Objective To compare the effects of small dose remifentanil and fentanyl on hemodynamic responses to orotracheal intubation in children.Methods Ninety ASAⅠorⅡchildren (57 males, 33 females) aged 3-9 yrs weighing 17-34 kg scheduled for elective plastic surgery under general anesthesia were randomly allocated to one of 3 groups (n = 30 each): groupⅠcontrol (C); groupⅡfentanyl (F) and groupⅢremifentanil (R) . The children were premedicated with intramuscular scopolamine 0.01 mg?kg-1(the maximum dose 0.3 mg) and midazolam 0.1 mg?kg-1.Anesthesia was induced with propofol 2.5 mg?kg-1 and vecuronium 0.1 mg?kg-1. In group F fentanyl 2?g?kg-1 was injectedⅣ5 min before intubation while in group R remifentanil 1?g?kg-1 was injectedⅣover 30 seconds immediately after vecuronium. Tracheal intubation was performed at 2 min after vecuronium injection. Noninvasive BP and HR were recorded and RPP (SBP?HR) was calculated before (baseline) and immediately after induction (T1),during intubation (T2) and at 1,2,3,4, 5 min after intubation.Results BP was significantly decreased after induction of anesthesia (T1) as compared to the baseline values in all 3 groups (P
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Objective: To evaluate the effects of sevoflurane on the dose-response relationship and on the timecourse of recovery of rocuronium. Method: Sixty patients,ASA grade Ⅰ,aged 18 to 52 years, undergoing elective plastic surgery,were included in this study. Patients were equally allocated randomly to either the control or the sevoflurane group. Anesthesia was maintained with 60％ N_2O-O_2-thiopental in the control group,and with 1 MAC sevofurane-N_2O-O_2 in the sevoflurane group. The dose-response relationship of rocuronium was established with a cumulative dosing regimen. Result: The dose response curve of rocuronium in the sevoflurane group was shifted to the left. The ED_(50),ED_(90) and ED_95 of rocuronium were decreased by 31％, 27％ and 25％, respectively in sevoflurane group as compared with those of the control group. Following an intravenous administration of rocuronium 400ug/kg,the duration of peak effect,duration of clinical relaxation,recovery index,and the total duration of action in the sevoflurane group were significantly prolonged vs. the control group. Conclusion: Sevoflurane can significantly enhance the neuromuscular blockade effect of rocuronium and prolong its duration of action.