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Objective To evaluate the role of protein kinase C in the maintenance of chronic inflammatory pain in rats and the relationship with the expression of Nav1.8 in the dorsal root ganglion (DRG).Methods Thirty pathogen-free healthy female Sprague-Dawley rats,weighing 180-220 g,were divided into 3 groups using a random number table:control group (group C),chronic inflammatory pain group (group CIP) and PKC inhibitor group (group P).Normal saline 20 μl was injected into the plantar surface of the right hindpaw every day for 14 consecutive days in group C.Prostaglandin E2 100 ng was injected into the plantar surface of the right hindpaw every day for 13 consecutive days to establish the model of chronic inflammatory pain,and dimethyl sulfoxide 20μl was injected into the plantar surface of the right hindpaw on 14th day in group CIP.Prostaglandin E2 100 ng was injected into the plantar surface of the right hindpaw every day for 13 consecutive days,and PKC inhibitor GF1O9203X 100 nmol/20 μl was injected into the plantar surface of the right hindpaw on 14th day in group P.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before injection (T0) and 1,3,7 and 14 days after the last injection (T1-4).The DRGs of the lumbar segment (L4.5) were removed for determination of Nav1.8 expression using immunofluorescence and Western blot.Results Compared with group C,the MWT was significantly decreased at T1-4 in CIP and P groups,and the expression of Nav1.8 in DRGs was significantly up-regulated in group CIP (P＜0.05).Compared with group CIP,the MWT was significantly increased at T4,and the expression of Nav1.8 in DRGs was down-regulated in group P (P＜0.05).Conclusion Up-regulated expression of Nav1.8 after PKC activation in DRGs is involved in the maintenance of chronic inflammatory pain in rats.
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Objective To evaluate the effect of curcumin pretreatment on c-Jun N-terminal kinase (JNK) signaling pathway during one-lung ventilation (OLV)-induced acute lung injury in mice.Methods Ninety SPF male C57BL/6J mice,aged 6-9 weeks,weighing 18-24 g,were randomly divided into 6 groups (n=15 each) using a random number table:two-lung ventilation (TLV) group;OLV group;curcumin 100,150,200 and 250 mg/kg groups (C100,C150,C200 and C250 groups).The corresponding doses of curcumin were administered intraperitoneally at 2 h before one-lung ventilation in C100,C150,C200 and C250 groups.The animals were tracheally intubated and mechanically ventilated in volume-controlled mode.The ventilator settings were adjusted to maintain the end-tidal pressure of carbon dioxide at 35-45 mmHg.In OLV,C100,C150,C200 and C250 groups,unilateral lung was ventilated for 1.5 h followed by 0.5 h of TLV.Bilateral lungs were ventilated for 2.0 h in group TLV.Peak airway pressure and airway pressure were recorded at 1.5 h of OLV and 0.5 h of TLV.At the end of mechanical ventilation,left lungs were removed for microscopic examination of the pathologic changes,and the index of quantitative assessment for alveolar damage (IQA) was recorded.Wet/dry lung weight ratio (W/D ratio) was determined,and the cell apoptosis in lung tissues was detected using TUNEL.The apoptosis index (AI) was calculated.The expression of JNK mRNA was determined using real-time polymerase chain reaction.The expression of JNK and phosphorylated JNK was determined by Western blot.The phosphorylation of JNK was calculated.Results Compared with group TLV,the IQA,W/D ratio,AI,expression of JNK mRNA and phosphorylation of JNK were significantly increased in group OLV (P＜0.05).Compared with group OLV,the IQA,W/D ratio,AI,expression ofJNK mRNA and phosphorylation of JNK were significantly decreased in C150,C200 and C250 groups,the parameters mentioned above were significantly decreased in sequence in C100,C150,C200 and C250 groups (P＜0.05),and no significant change was found in the parameters mentioned above in group C100 (P＞ 0.05).Compared with group OLV,the pathological changes were significantly attenuated in sequence in C150,C200 and C250 groups.Conclusion The mechanism by which curcumin pretreatment reduces cell apoptosis during OLV-induced acute lung injury is related to inhibition of JNK signaling pathway activation in mice.
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Objective To evaluate the blood-saving effect of tranexamic acid in pediatric patients undergoing radical correction of tetralogy of Fallot with cardiopulmonary bypass (CPB).Methods A total of 56 children of both sexes,aged 11 months-14 yr,with body mass index of 9.8-21.4 kg/m2,of ASA physical status Ⅱ or Ⅲ,with left ventricular ejection fraction ＞50％,scheduled for elective radical correction of tetralogy of Fallot with CPB,were randomly divided into 2 groups using a random number table:tranexamic acid group (TA group,n =30) and normal saline group (NS group,n =26).Anesthesia was induced with iv midazolam,sufentanil,vecuronium and propofol.The children were endotracheally intubated and mechanically ventilated.Anesthesia was maintained with inhalation of 1％-2％ sevoflurane and infusion of propofol,sufentanil and vecuronium.After induction of anesthesia,a loading dose of tranexamic acid l0 mg/kg was intravenously infused over 20 min before skin incision,followed by infusion at a rate of 10 mg · kg-1 · h 1 until the end of surgery in TA group,while the equal volume of normal saline was given instead in NS group.The volume of chest tube drainage at 24 h after surgery and volume of allogeneic red blood cells,fresh frozen plasma,platelet and cryoprecipitate transfused were recorded.The requirement for re-thoracotomy for bleeding,and the incidence of hepatic artery and portal vein thrombosis were also recorded.Results Compared to NS group,the volume of chest tube drainage at 24 h after surgery and volume of allogeneic red blood cells,fresh frozen plasma,platelet and cryoprecipitate transfused were significantly reduced in TA group.No re-thoracotomy was required in TA group,and the rate of re-thoracotomy was 15％ in NS group.No hepatic artery and portal vein thrombosis were detected in group TA.Conclusion Tranexamic acid (loading dose 10 mg/kg,maintenance dose 10 mg· kg-1 · h-1) can provide blood-saving effect and has high security in pediatric patients undergoing radical correction of tetralogy of Fallot with CPB.
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In order to extract more information from extracellular action potential (EAP) of neurons recorded deep in the brain tissue, we established simulation models of various pyramidal neurons in the hippocampal CA1 region and investigated the effects of dendrite currents, cell morphology and ion mechanisms on the formation of EAP waveforms. The results show that dendrite currents have significant effects on the EAP at the locations far from cell body, but not on those near cell body. The differences of shape of various pyramidal neurons result in large changes in the EAP amplitudes. However, the shapes of these different EAP are very similar. Ion mechanisms, such as calcium channels, have little effect on EAP waveforms. These results provide important information for experimental EAP recordings, EAP data analysis, and developing new methods to extract more neuronal data from EAP.
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Animals , Rats , Action Potentials , Physiology , Computer Simulation , Hippocampus , Cell Biology , Models, Biological , Neurons , Physiology , Pyramidal CellsABSTRACT
Objective To discuss the effects of remifentanfl for delthemte hypotension in intracranial aneurysm clamp operation,evaluating the feasibility and safety.Methods Twenty intracranial aneurysm patients undergoing occlusion surgery were prospectively randomized in to two groups:Group Ⅰ and Group Ⅱ.Group Ⅰ adopted remifentanil for deliberate hypotension and Group Ⅱ adopted sodium nitroprusside.The data were analyzed with SPSS 11.5 for Windows.Results Deliberate hypotension was achieved at the target mean arterial pressure(MAP)for remifentanil and nitroprusside respectively.During deliberate hypotension,HR in Group Ⅰ were lower than that in Group Ⅱ(P<0.01).RPP in Group Ⅰwere lower than that in Group Ⅱ(P<0.01).Blood loss in Group Ⅰ were lower than that in Group Ⅱ(P<0.05).Conclusion For general anesthesia in intracranial aneurysm clamp operation,using remifentanil for deliberate hypotemion is a good choice.