Objective To evaluate the effects of different concentrations of dexmedetomidine on large-con-ductance Ca2+-activated K+ (BKca) channels in the rat mesenteric arterial smooth muscle (MASM) cells.Methods Sprague-Dawley rats of both sexes,weighing 180-220 g,were used in this study.Single MASM cell was freshly isolated from mesenteric arteries in two steps.Ten cells were chosen and studied.When holding potential was 40 mV and the concentration of free calcium ions was 10-7 mol/L,inside-out patch-clamp technique was used to record the single BKCa channel current before and after application of different concentrations of dexmedetomidine (0,10-9,10-8,10-7,10-6,10-5 mol/L).Total open probability (NPo),amplitude (Am),mean open time (To) and mean close time (To) of single BKca channel were observed and recorded.Results Compared with the baseline value,dexmedetomidine 10-7,10-6 and 10-5 mol/L increased NPo in a concentration-dependent man-ner,and dexmedetomidine 10-9,10-8,10-7,10-6,10-5mol/L shortened Tc (P ＜0.05 or 0.01).Compared with the value obtained when the concentration of dexmedetomidine was 10-9 mol/L,Tc was significantly shortened when the concentration of dexmedetomidine was 10-8 mol/L (P ＜ 0.05),and no significant change was found in Am and To obtained when different concentrations of dexmedetomidine were applied (P ＞ 0.05).Conclusion Dexmedetomidine 10-7,10-6 and 10-5 mol/L activate BKca channels in rat MASM cells in a concentration-depen-dent manner,which is one of the mechanisms of decrease in blood pressure by dexmedetomidine.

ObjectiveTo investigate the effects of sevoflurane postconditioning on myocardial neutrophil infiltration in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Twenty-four ASA Ⅱ or Ⅲ patients (NYHA Ⅱ or Ⅲ ) of both sexes aged 20-50 yr with BMI of 19-25 kg/m2 undergoing cardiac valve replacement under CPB were randomly divided into 2 groups ( n =12 each):group control (group C) and group sevoflurane postconditioning (group S).Anesthesia was induced with midazolam,fentanyl,etomidate and rocuronium and maintained with iv infusion of fentanyl,midazolam and vecuronium.The patients were intubated and mechanically ventilated (VT 8-10 ml/kg,RR 10-14 bpm,I∶E 1∶2,FiO2 100％ ).PETCO2 was maintained at 35-40 mm Hg.In group S sevoflurane was inhaled immediately after aorta and vena cava were unclamped.The end-tidal sevoflurane concentration was maintained at 1.7％ for 5 min.Arterial blood samples were collected before surgery and at 1,2 and 4 h after aortic unclamping for determination of plasma cardiac troponin T concentration.Myocardial specimens were obtained from right auricular appendage after opening of pericardium and at 1 h after aortic unclamping for microscopic examination and determination of myocardial myeloperoxidase expression.ResultsSevoflurane postconditioning significantly decreased plasma cardiac troponin T concentration and myocardial myeloperoxidase expression and ameliorated histo-pathological damage in group S as compared with group C.ConclusionMyocardial neutrophil infiltration is involved in the protective effect of sevoflurane postconditioning against myocardial injury in patients undergoing cardiac valve replacement under CPB.

Objective To investigate the effects of low molecular weight polysaccharide lsolated from agaricus blazei murill (LMPAB) on adhesion and migration of tumor cell and HUVECs. Methods HT-29 cell and HUVECs proliferation was analyzed by MTT.Adhesion and transmigration monolayer HUVECs ability of HT-29 was examined by spectrophotometry and transwell chambers.Results LMPAB showed no cytotoxic effect on HT-29 cells and HUVECs. LMPAB could significantly decrease HT-29 adhesion and transmigration through HUVECs.Conclusion LMPAB exerts the anti-tumor metastasis activity via inhibition of tumor cell adhesion and migration HUVECs.

Objective To investigate the effects of hydrogen inhalation on the brain injury after intestinal ischemia/reperfusion (I/R) in rats.Methods Fifty-four healthy male Sprague-Dawley rats aged 6-8 months,weighing 285-350 g,were randomly allocated to one of 3 groups (n =18 each):sham operation group (group S),intestinal I/R group (group I/R) and hydrogen inhalation group (group H2).Intestinal I/R was produced by occlusion of the superior mesenteric artery for 90 min followed by reperfusion.2％ hydrogen was inhaled for 3 h starting from the end of ischemia.The cognitive function was detected at 1,2 and 5 days of reperfusion using Morris water maze test.The animals were sacrificed after the test and brains were isolated for detection of the cerebral edema and morphology in brain tissues.The cerebral water content ((wet weight-dry weight)/ wet weight × 100％) was measured.The pathological changes in the prefrontal cortex was observed under light microscope.The neuronal apoptosis was detected by TUNEL.Results Compared with the S group,the number of normal neurons in the prefrontal cortex was significantly decreased,the latency and swimming distance were both prolonged,the frequency of crossing the original platform was decreased,and the cerebral water content and the number of apoptotic neurons were increased in groups I/R and H2 (P ＜ 0.05).Compared with I/R group,the number of normal neurons in the prefrontal cortex was significantly increased,the latency and swimming distance were both shortened,the frequency of crossing the original platform was increased,the cerebral water content and the nunber of apoptotic neurons were decreased in group H2 (P ＜ 0.05).The pathological changes were obvious in I/R group,however,they were significantly attenuated in H2 group.Conclusion H2 inhalation can reduce the brain damage and improve the cognitive dysfunction after intestinal I/R in rats.

Objective To investigate the effects of intestinal ischemia-reperfusion(I/R)on cerebral microglial activation in rats.Methods One hundred and twenty-eight healthy male SD rats weighing 250-300 g were randomly allocated to one of two groups(n =64 each):group sham operation(group S)and intestinal I/R group.Intestinal I/R was produced by occlusion of superior mesenteric stery for 90 main followed by reperfusion.Sixteen animals were sacrificed at each of the 4 time points:2,6,24 and 48 h of reperfusion in each group.Their intestines were obtained for microscopic examination.Their brains were harvested for detection of microglial activation (by immuno-histochemistry).The reactive oxygen species(ROS),MDA and NO contents and SOD,nitric oxide synthase(NOS)and inducible nitric oxide synthase(iNOS)activities in the brain were measured.Results The microglia were in quiescent condition.Ibal staining was negative or light in group S.Intestinal I/R significantly increased intestinal Chiu score,cerebral microglial activation at 6,24 and 48 h of repeffusion which peaked at 24 h of reperfusion in group I/R as compared with group S.Cerebral ROS,MDA,NO levels and NOS,iNOS activities were significantly higher while SOD activity was significantly lower in group I/R than in group S.Concluslon Intestinal I/R can activate microglia and induce the release of nitrogen and oxygen free radicals resulting in cerebral injury.

Objective To investigate the role of large-conductance Ga2+-activated K+ (BKCa) channels and protein kinase G (PKG) in ketamine-induced isolated tracheal smooth muscle relaxation in rats with asthma.Methods Healthy Sprague-Dawley rats,weighing 250-300 g,were used in this study.Asthma was induced with egg albumin.Thirty-six tracheal rings of 15 rats in which asthma model was successfully established were randomly divided into 3 groups (n =12 each):ketamine treatment group (group AK),IBTX (BKCa channel blocker) +ketamine treatment group (group AKI),and KT-58232 (PKG inhibitor) + ketamine treatment group (group AKK).Tracheal rings were suspended in an organ bath filled with oxygenated Kreb's solution at 36.5-37.5 ℃.In group AK,the tracheal rings were precontracted with acetyleholine 0.1 mmol/L,and the rings were then exposed to ketamine 0.4 g/L for 15 min.In group AKI,before acetyleholine and ketamine were added to the solution,the rings were pretreated with IBTX 3μmol/L for 30 min.In group AKK,before acetyleholine and ketamine were added to the solution,the rings were pretreated with KT-5823 2μmol/L for 30 min.The tension of rings was measured by using a force-displacement transducer.Results The amplitude of relaxation of isolated tracheal smooth muscle was significantly decreased in groups AKI and AKK as compared with group AK (P ＜ 0.05).Conclusion Ketamine induces isolated tracheal smooth muscle relaxation through activating BKCa channels and PKG signaling pathway in rats with asthma.

Objective To evaluate the the protectice effect of dexmedetomidine combined limb remote ischemic postcondition on alleviating focal cerebral ischemic reperfusion injury in rats .Methods 48 healthy adult male SD rats were randomly divided into 4 groups(n= 12) :control group(C) ,limb remote ischemic postcondition group(R) and dexmedetomidine postconditioning group(D) and combination group(R/D) .The rat model of focal cerebral ischemic reperfusion injury was induced by middle cerebral artery oc‐clusion(MCAO) .The group C only received MCAO ,the left femoral artery was isolated without blocking ;the group R received 120 min brain ischemia ,the left femoral artery was occluded by 3 cycles of 10 min occlusion/10 min reperfusion before brain reperfu‐sion ;the group D received dexmedetomidine 3 μg/kg by intraperitoneal injection before brain reperfusion .The group R/D combined the above two kinds of processing method .The neurologic function was evaluated at 24 h of reperfusion and then the rats were sac‐rificed at 48 h of reperfusion .The brain was removed for determining the cerebral infarct volume .Results The neurologic function scores after 24 h reperfusion in the group D ,R and R/D were superior to those in the group C (P< 0 .01) .The rat cerebral infarct volume percentages after 48 h reperfusion in the group D ,R and R/D were significantly lower than those in the group C ( P <0 .01) .The infarct area volume percentage in the group R/D was significantly lower than that in the group R ,the difference showed statitistical significance(P< 0 .01) .The infarct volume percentage in group R/D was significantly decreased compared with the group D(P< 0 .05) .Conclusion Both dexmedetomidine and limb remote ischemic postcondition can attenuate the focal cerebral is‐chemic reperfusion injury in rats .Their combination can significantly reduce the cerebral infarction volume and has synergic protec‐tion effect .

Objective:To study the antitumor effect and mechanism of cocultured CIK cells modified with IL-24 gene and autologous DCs on HL-60 cells in vitro.Methods:DCs and CIK cells were prepared routinely from human peripheral blood mononuclear cells ( PBMC).IL-24 gene was transferred into CIK cells via electroporation.The cells obtained were named CIK-IL24.RT-PCR and ELISA were used to evaluate expression of IL-24 gene in transfected CIK cells.The phenotypic changes of CIK cells were identified by flowcytometry analysis.The concentration of IFN-γ and TNF-α in supernatant of CIK was determined by ELISA.FCM was used to determine the cytotoxicity of cocultured CIK cells modified with IL-24 gene and autologous DCs against HL-60 cells.Results:Eukaryotic expressing plasmid pcDNA3.0-IL24 was transferred into CIK cells successfully via electroporation.The expressing rate of CD3~+、CD3~+CD56~+ cells had no significant change in CIK cells.However,the rate of CD4~+CD25~+ cells was significantly decreased compared with that of the control group.Expression of adhesion molecules CD54,CXCR4 were significantly increased on CD3+CD56+ cells.CIK-IL24 cells produced markedly higher levels of IFN-γ and TNF-α as compared with the CIK cells.By comparison with non-transfected CIK cells co-cultured with DCs,transfected CIK cells co-cultured with DCs had a significantly higher lytic activity against HL-60 cells.Conclusion:IL-24 gene modification can enhance the anti-tumoral immunity of CIK cells,the mechanism of which might be related to the increased secretion of IFN-γ,TNF-α,up-regulation of adhesion molecule expression,and reduction of the rate of CD4~+CD25~+ cells in CIK cells.

Objective To evaluate the efficacy of embryo thymus transplantation in the treatment of lupus-like BXSB mice,study the pathogenesis of SLE in BXSB mice and the therapeutic effect of embryo thymus transplantation.Methods The embryonic thymus of CB57L mice was transplanted to50day-old male BXSB mice.Levels of proteinuria,ANA,blood urea nitrogen(BUN),blood creatinine and the deposits of immunoglobulin(Ig)in the glomerulus were detected regularly for5months,and the number of mice died of SLE was observed.Results The levels of proteinuria,ANA,BUN,blood creatinine of the5,6,7month old mice in embryo thymus transplantation group were lower than that of5month old mice in control group.The efficacy of treatment in embryo thymus transplantation group were similar to that of dexamethasone treatment group,and the SLE-caused death was reduced in these two groups.However,the embryo thymus transplantation seemed not to reduce the deposits of lg in glomerulus significantly,the deposits of lg in the glomerulus were similar in all three groups.Conclusions Embryo thymus transplantation could improve renal functions and reduce the titer of ANA.Its efficacy is similar to that of dexamethasone.Embryo thymus transplantation has a short term therapeutic effect in the treatment of lupus-like BXSB mice.The deficiency of thymus in the BXSB mice may play an important role in the pathogenesis of lupus-like mice.Embryo thymus transplantation may be a valuable approach to treat SLE.

Objective To study the antitumor effect and mechanism of co-cultured cytokine-induced killer(CIK) cells and autologous DC modified with IL-24 gene on A549 cells in vitro. Methods DC and CIK cells were prepared routinely from human peripheral blood mononuclear cells(PBMC). Recombinant adenovirus vector pAdEasy-1-pTrack-CMV-IL-24 was extracted from DH5α, it was lineared with Pac I and transfected into A293 cells, and then the IL-24 recombined adenovirus(Ad-IL-24) was obtained. Ad-IL-24 was used to infect DC. The cells obtained were named DC-IL-24. RT-PCR and ELISA were used to evaluate the expression of IL-24 gene in transfected DC. The phenotypes change of DC were identified by flow cytometry analysis, the concen-tration of IL-12 and TNF-α in supernatant of DC were determined by EIJSA. The ability of CIK producing per-forin was measured by homolysis method. FCM was used to determine the cytotoxicity of cocultured CIK cells and autologous DC modified with IL-24 gene to A549 cells. Results We obtained the high titre of Ad-IL-24.IL-24 gene was transfered into DC successfully via Ad-IL-24. The green fluorescence was observed on DC by fluorescence microscope. The expression rate of CD80, CD83, HI.A-DR, CD40, CXCR4 on DC-IL-24 was sig-nificantly increased compared with that of the control group. DC-IL-24 produced markedly higher levels of IL-12 and TNF-α as compared with DC. DC-IL-24 can enhance the ability of CIK cells producing perforin. On com-parison with non-transfected DC co-cultured with CIK cells, transfected DC co-cultured with CIK cells had a sig-nificantly higher lytic activity against A549 cells. Conclusion IL-24 gene modification can enhance the anti-tu-moral immunity of DC. The mechanism of which might be related to the increased secretion of IL-12 and TNF-α, up-regulation expression of co-stimulatory molecules and MHC Ⅱ class molecules on DC, promoting the acti-vation and maturation of DC, and then enhancing CIK cells to generate specific anti-tumoral immunity.