Objective To evaluate the effects of dexmedetomidine on the activity of c-Jun N-terminal kinase (JNK) during cerebral ischemia-reperfusion (I/R) in rats.Methods Eighty-one pathogen-free male Sprague-Dawley rats,aged 8 weeks,weighing 180-220 g,were randomly divided into 3 groups (n=27 each) using a random number table:sham operation group (group S);cerebral I/R group (group CI/R);dexmedetomidine group (group Dex).The rats were anesthetized with intraperitoneal 10％ chloral hydrate 300 mg/kg.Cerebral ischemia was induced by occlusion of the middle cerebral artery for 2 h followed by 24 h of reperfusion in CI/R and Dex groups.The middle cerebral artery was only exposed but not occluded in group S.Dexmedetomidine 3 μg/kg was injected via the tail vein immediately before ischemia followed by infusion at a rate of 3 μg · kg-1 · h-1until 24 h of reperfusion in group Dex,while the equal volume of normal saline was given in S and CI/R groups.The rats were sacrificed at 24 h of reperfusion,and their brains were removed for determination of cerebral infarct size (by TTC staining),brain water content ((wet weight-dry weight)/wet weight × 100％),cell apoptosis (by TUNEL) and expression of phosphorylated JNK (p-JNK) protein (by Western blot analysis).Apoptotic index was calculated.Results Compared with group S,the brain water content,apoptotic index and cerebral infarct size were significantly increased,and the expression of p-JNK was up-regulated in CI/R and Dex groups.Compared with group CI/R,the brain water content,apoptotic index and cerebral infarct size were significantly decreased,and the expression of p-JNK was down-regulated in group Dex.Conclusion Dexmedetomidine reduces cerebral I/R injury through decreasing the activity of JNK and inhibiting cell apoptosis in rats.

Objective To investigate the effect of hyperoxia on the expression and transport function of epithelial sodium channel (ENaC) in neonatal rat alveolar epithelial type Ⅱ(AT Ⅱ) cells.Methods AT Ⅱ cells were isolated from neonatal rats,and primarily cultured under hyperoxic or normoxic conditions.Western blot was applied to examine the ENaC expression,and the amiloride-sensitive Na + currents were recorded using the whole-cell patch clamp technique.Results Hyperoxia upregulate the expression of β-ENaC and γ-ENaC subunits in the neonatal rat ATⅡ cells(β-ENaC:1 d:0.43 ±0.06 vs0.32 ±0.04,P =0.047;2 d:0.73±0.06 vs 0.50±0.08,P =0.019;3 d:0.72 ±0.08 vs 0.52 ±0.06,P =0.027;γ-ENaC:1 d:0.64±0.05 vs0.53 ±0.05,P =0.044;2 d:0.76 ±0.03 vs 0.52 ±0.04,P =0.001 ;3 d:0.77 ±0.06 vs 0.61 ±0.05,P =0.025).In addition,the amiloride-sensitive Na+ currents in hyperoxia-exposed AT Ⅱ cells were also increased (1d:13.71 ±2.77 vs8.92±1.38,P＜0.001;2d:29.12±11.03 vs 10.41 ±1.80,P＜0.001),which was consistent with the upregulated expression of β-ENaC and γ-ENaC.However,the expression of α-ENaC was inhibited by hyperoxia to some extent (1 d:0.31 ± 0.05 vs 0.46 ± 0.05,P =0.025 ; 2 d:0.30 ±0.01 vs0.38±0.02,P=0.002;3d:0.37±0.06 vs 0.37 ± 0.08,P =0.983).Conclusion Hyperoxia enhanced the transport function of ENaC in neonatal rat AT Ⅱ cells.Dysfunctional transport of Na + may not be a key factor involving in pulmonary edema at the early stage of bronchopulmonary dysplasia.

Objective To determine the median effective dose (ED50) of hemocoagulase agkistrodon (HCA) inhibiting the bleeding after trans-bronchial lung biopsy (TBLB).Methods ASA physical status Ⅰ or Ⅱ patients of both sexes,aged 45-75 yr,body mass index 19-24 kg/m2,scheduled for elective TBLB,were enrolled in this study.TBLB was performed after routine anesthesia.HCA diluted in normal saline 5 ml was locally injected into the biopsy site at 2 min before surgery.The initial dose of HCA was 1.4 U.The dose of HCA was determined by up and down sequential method.Each time the dose of HCA increased/decreased in the next patient depending on whether nor not the bleeding was observed in the biopsy wound under fiberoptic bronchoscope.The ratio between the two successive concentrations was 1.2.The ED50 and 95 ％ confidence interval of HCA were calculated by Dixon's up-and-down method.Results ED50 of HCA inhibiting the bleeding after TBLB was 0.9 U,and 95 ％ confidence interval was 0.7-1.1 U.Conclusion ED50 of HCA inhibiting the bleeding after TBLB is 0.9 U.

Objective To evaluate the role of mitochondrial ATP-sensitive potassium (mito-KATe) channels in attenuation of cerebral ischemia-reperfusion (I/R) injury by dexmedetomidine in rats.Methods One hundred and twenty healthy male Wistar rats,weighing 290-340 g,were randomly assigned into 5 groups (n =24 each) using a random number table:sham operation group (group S) ; group I/R; dexmedetomidine group (group D) ; 5-HD (a specific blocker of mito-KATPchannel) group and 5-HD + dexmedetomidine group (group 5-HD + D).The rats were anesthetized with intraperitoneal chloral hydrate.Focal cerebral I/R was produced by 2 h middle cerebral artery occlusion followed by reperfusion.In group D,dexmedetomidine 50 μg/kg was injected intraperitoneally before ischemia and after onset of reperfusion.In group 5-HD,5-HD 30 mg/kg was injected intraperitoneally at 1 h before ischemia.In 5-HD + D group,5-HD 30 mg/kg was injected intraperitoneally at 1 h before ischemia and the other procedures were similar to those previously described in group D.Twelve rats were chosen at 24 and 48 h of reperfusion to assess the neurological deficit score (NDS).The animals were then sacrificed and brains were removed for determination of cerebral infarct size by TTC staining.Results Compared with S group,NDS and cerebral infarct size were significantly increased at each time point in the other four groups (P ＜ 0.05).Compared with group I/R,NDS and cerebral infarct size were significantly decreased in D and 5-HD + D groups (P ＜ 0.05),and no significant change was found in the parameters mentioned above in 5-HD group (P ＞ 0.05).Compared with group D,NDS and infarct size were significantly increased in group 5-HD + D (P ＜ 0.05).Conclusion Mito-KATP channels are involved in reduction of I/R-induced cerebral injury by dexmedetomidine in rats.

Objective To evaluate the therapeutic effect of hydrogen-rich saline on allergic contact dermatitis (ACD) in mice and to explore its underlying mechanisms.Methods Forty mice were equally divided into 4 groups:control group,control treatment group,ACD group and ACD treatment group.ACD was induced by repetitive topical application of dinitrofluorobene (DNFB) to the left ear of mice on day 1,2 and 5.Hydrogen-rich saline was intraperitoneally given to the mice in the ACD treatment group at a dose of 5 ml/kg per day from day 1 to 5.On day 6,the mice were sacrificed,ear tissue was removed from them and subjected to measurement of thickness and weight,detection of tumor necrosis factor (TNF)-α,interleukin (IL)-6,IL-17 and interferon (IFN)-γ expression by enzyme linked immunosorbent assay,as well as numeration of inflammatory cells in lesions after hematoxylin-eosin (HE) staining.Data were processed by SPSS 18.0 software,and statistical analysis was carried out by one-way analysis of variance and least significant difference (LSD) procedure.Results Compared with the control group,the ACD group showed a significant increase in lesion score (7.33 ± 1.53 vs.0,P ＜ 0.05),differences in the thickness ((0.73 ± 0.15) mm vs.(0.13 ± 0.05) mm,P ＜ 0.05) and swelling degree (expressed as tissue weight:(18.67 ± 3.05) mg vs.(3.33 ± 1.52) mg,P ＜ 0.05) between the left and right ear,expressions of TNF-α ((1475.52 ± 233.81) pg/mg vs.(239.01 ± 52.39) pg/mg,P＜ 0.05),IL-6 ((184.65 ± 78.39) pg/mg vs.(42.28 ± 17.64) pg/mg,P＜ 0.05),IL-17 ((628.56 ± 201.44) pg/mg vs.(127.58 ± 50.28) pg/mg,P＜ 0.05) and IFN-γ ((197.72 ± 37.81) pg/mg vs.(24.57 ± 8.31) pg/mg,P ＜ 0.05),and the number of inflammatory cells per square millimetre in the left ear tissue (752.00 ± 166.06 vs.127.33 ± 77.18,P ＜ 0.05).However,hydrogen-rich saline treatment induced a statistical decrease in all of these parameters in the ACD treatment group compared with the ACD group,including lesion score (3.33 ± 0.58,P ＜ 0.05),difference in thickness ((0.46 ± 0.11) mm,P ＜ 0.05) and swelling degree ((11.00 ± 2.64) mg,P ＜ 0.05),expressions of TNF-α ((817.72 ± 101.13) pg/mg,P＜ 0.05),IL-6 ((95.86 ± 36.65) pg/mg,P＜ 0.05),IL-17 ((373.38 ± 126.74) pg/mg,P＜ 0.05),IFN-γ ((63.31± 17.38) pg/mg,P ＜ 0.05) and the number of inflammatory cells per square millimetre (384.00 ± 97.35,P ＜0.05).Conclusion Hydrogen may inhibit the release of inflammatory factors in ACD.

Objective To evaluate the effects of propofol on the expression of hippocampal γ-aminobutyric acid (GABAA) and NMDA receptor in a rat model of inflammatory pain (IP).Methods A total of 32 female Sprague-Dawley rats,weighing 180-220 g,were randomly divided into 4 groups (n =8 each):control group (group C),group IP,and different doses of propofol groups (P1,2 groups).IP was induced by injection of formalin.In group C,normal saline and dimethyl sulfoxide (DMSO) 0.1 ml/kg were injected intraperitoneally.In group IP,normal saline and DMSO 0.1 ml/kg were injected intraperitoneally,and 5 min later formalin was injected.In P1,2 groups,propofol 30 and 100 mg/kg were intraperitoneally injected,respectively,and 5 min later formalin was injected.The pain behavior of rats was observed within 1 h after injection of formalin and pain intensity scoring (PIS) value was calculated.The animals were sacrificed at 1 h after injection of formalin and the hippocampi were isolated for determination of GABAA and NMDA receptor expression by immunohistochemisty.Results Compared with group C,PIS value was significantly increased,GABAA and NMDA receptor expression was up-regulated in IP and P1.2 groups.Compared with group IP,PIS value was significantly decreased,GABAA receptor expression was up-regulated,and NMDA receptor expression was down-regulated in P1,2 groups.PIS value was significantly lower,GABAA receptor expression was higher,and NMDA receptor expression was lower in group P2 than in group P1.Conclusion Intraperitoneal propofol can down-regulate NMDA receptor expression in hippocampi of rats with IP,thus inhibiting responses to pain sensitivity; intraperitoneal propofol can up-regulate hippocampal GABAA receptor expression,thus enhancing endogenous mechanism of analgesia.

Objective To investigate whether hydrogen can regulate the expressions of inflammatory factors by ultraviolet B (UVB)-induced human HaCaT keratinocytes through the autophagy pathway.Methods Cultured HaCaT keratinocytes were divided into several groups:blank control group receiving no treatment,hydrogen group cultured in hydrogen-rich medium,three UVB groups irradiated with UVB at 1,10,50 mJ/cm2 respectively,three UVB + hydrogen groups irradiated with UVB at 1,10,50 mJ/cm2 respectively followed by culture in hydrogen-rich medium,UVB + 3MA group pretreated with the autophagy inhibitor 3MA for 1 hour followed by UVB radiation at 50 mJ/cm2,UVB + rapamycin group pretreated with the autophagy activator rapamycin for 1 hour followed by UVB radiation at 50 mJ/cm2,UVB + 3MA +hydrogen group pretreated with 3MA for 1 hour followed by UVB radiation at 50 mJ/cm2 and culture in hydrogen-rich medium,UVB + rapamycin + hydrogen group pretreated with rapamycin for 1 hour followed by UVB radiation at 50 mJ/cm2 and culture in hydrogen-rich medium.After additional culture with or without hydrogen for 12 hours,methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate cellular proliferative activity,Western-blot analysis to measure the expressions of autophagy-associated protein 1 light chain 3 (LC3) and Beclin 1,and enzyme-linked immunosorbent assay (ELISA) to measure the supernatant levels of inflammatory factors including tumor necrosis factor (TNF)-α,interleukin (IL)-1β,IL-6 and high mobility group protein B1 (HMGB1),and a test kit was used to determine the level of lactate dehydrogenase (LDH).Results Compared with the blank control group,the 10-and 50-mJ/cm2 UVB groups showed significantly increased release of LDH,expressions of LC3 and Beclin1 and supernatant levels of TNF-α,IL-1 β,IL-6 and HMGB 1,but decreased cellular proliferative activity (all P ＜ 0.05).Hydrogen significantly attenuated the release of LDH,down-regulated the supernatant levels of TNF-α,IL-1β,IL-6 and HMGB1,but up-regulated cellular proliferative activity as well as LC3 and Beclin1 expressions in the 10-and 50-mJ/cm2 UVB + hydrogen groups compared with the 10-and 50-mJ/cm2 UVB groups respectively (all P ＜ 0.05).In addition,the levels of TNF-α,IL-1β,II-6 and HMGB1 were significantly higher in the 50-mJ/cm2 UVB + 3MA group than in the 50-mJ/cm2 UVB group,and higher in the 50-mJ/cm2 UVB + 3MA + hydrogen group than in the 50-mJ/cm2 UVB + hydrogen group,but lower in the 50-mJ/cm2 UVB + rapamycin group than in the 50-mJ/cm2 UVB group (all P＜ 0.05).Conclusion UVB radiation can increase the expressions ofautophagy-associated proteins,and hydrogen-rich medium can down-regulate the expressions of inflammatory factors by UVB-induced HaCaT cells through the autophagy pathway.

Objective:To evaluate the role of ten-eleven translocation methylcytosine dioxygenase 3 (TET3) in trigeminal ganglion in maxillofacial inflammatory pain in mice.Methods:Forty SPF healthy male C57BL/6J mice, aged 8-10 weeks, weighing 19-23 g, were divided into 5 groups ( n=8 each) using a random number table method: control group (group C), inflammatory pain group (group IP), control+ TET3-siRNA group (group C+ siTET3), inflammatory pain+ TET3-siRNA group (group IP+ siTET3) and inflammatory pain+ negative control Scrambled-siRNA group (group IP+ siNC). Normal saline or complete Freund′s adjuvant (CFA) 10 μl was injected into the temporomandibular joint of mice, respectively, and the mechanical paw withdrawal threshold (MWT) was measured at 1, 4, 8 and 12 days after injection (T 1-4). Before injection of normal saline or CFA, 0.75 μl siTET3 or siNC was injected into the trigeminal ganglion and the animals were then sacrificed and trigeminal ganglion was removed at T 2 for determination of the expression of TET3 by Western blot in C+ siTET3, IP+ siTET3 and IP+ siNC groups. Results:Compared with group C, MWT was significantly decreased at T 1-3 , the expression of TET3 in trigeminal ganglion was up-regulate in group IP ( P<0.05 or 0.01). Compared with IP and IP+ siNC groups, MWT was significantly increased at T 2, 3, and the expression of TET3 in trigeminal ganglion was down-regulate in group IP+ siTET3 ( P<0.05 or 0.01). Conclusion:TET3 in trigeminal ganglion is involved in the development of maxillofacial inflammatory pain in mice.

Objective To observe the effect of hydrogen on ultraviolet B (UVB)-induced oxidative damage to skin fibroblasts.Methods Primary human skin fibroblasts from foreskin tissues were divided into five groups:normal control group receiving no treatment,hydrogen control group treated with hydrogen-rich saline,UVB group receiving irradiation only,post-treatment group irradiated with UVB followed by hydrogen-rich saline treatment,and pre-treatment group treated with hydrogen-rich saline followed by UVB irradiation.The dose of UVB was 30,60 and 90 mJ/cm2 in the cell proliferation assay and 90 mJ/cm2 in the other experiments.Methyl thiazolyl tetrazolium (MTT) assay was performed to evaluate the proliferative activity of fibroblasts,a chemiluminescence method to estimate the activity of superoxide dismutase (SOD) and catalase as well as to determine the level of malondialdehyde in the culture supernatant of fibroblasts,enzyme linked immunosorbent assay (ELISA) to determine the supernatant level of 8-isoprostane-prostaglandin F2α (8-iso-PGF2α),Western blot to detect the expression of heme oxygenase-1 (HO-1) in fibroblasts.One-factor analysis of variance was conducted to assess differences in these parameters among these groups.Results UVB irradiation decreased the proliferative activity (absorbence value at 490 nm) of fibroblasts in a dose-dependent manner.Both the pre-treatment group and post-treatment group showed a statistical increase in proliferative activity of cells compared with the corresponding UVB control groups (all P ＜ 0.05).The activity of SOD and catalase as well as the protein expression of HO-1 were significantly higher (all P ＜ 0.05),whereas the supernatant levels of malondialdehyde and 8-iso-PGF2α were statistically lower (both P ＜ 0.05) in the pre-treatment group and post-treatment group than in the UVB control group.Conclusion Hydrogen may mitigate UVB-induced oxidative damage to skin fibroblasts.

Objective To evaluate the safety of dynamic anterior plate fixation for cervical distractive flexion injuries and compare its rigidity between different types of plate design. Methods Twelve sets of cadaveric calf spine were used in this test. All the specimens were made into distractive flexion injury models (C4-C5) ac- cording to Allen's method. After discectomy and grafting, they were randomized into three groups in which Orion, Codman, and Window instrumentations were used respectively. The stiffness of each construct was tested in flexion, extension, lateral bending and axial torsion conditions sequentially. Results Compared with an intact cervical spine, the range of motion (ROM) of an injured cervical spine increased whatever plate was applied. Orion in- strumentation presented stiffness the closest to that of the normal control, except for less torsional stiffness. Codman instrumentation provided stiffness close to that for normal and Orion groups only in lateral bending. Window's was the weakest mad not enough in all kinds of movement. Conclusions Static anterior fixation is the first choice for cervical injuries. Dynamic plate fixation may sacrifice stiffness to some extent, especially when a shifting kind of design is to be chosen.