Objective To investigate the placental transfer and neonatal effects of dexmedetomidine during the cesarean section under general anesthesia.Methods Thirty-eight nulliparous parturients,of American Society of Anesthesiologists physical status Ⅰ or Ⅱ,aged 22-37 yr,weighing 56-82 kg,who were at full term with a singleton fetus,scheduled for elective caesarean section under general anesthesia,were randomly divided into 2 groups (n=19 each) using a random number table:dexmedetomidine group (group D) and normal saline group (group N).In group D,dexmedetomidine was infused in a loading dose of 0.6 μg/kg starting from 10 min before induction of anesthesia,followed by an infusion of 0.4 μg · kg-1 · h-1 until peritoneal closure.Group N received the equal volume of normal saline.Blood samples were collected from the maternal artery (MA),umbilical vein (UV),and umbilical artery (UA) for blood gas analysis and for determination of plasma dexmedetomidine concentrations (CMA,CUV and CUA) by high-performance liquid chromatography-mass spectrometry,and CUV/CMA and CUA/CUV were calculated.Apgar scores were recorded at 1 and 5 min after delivery,and the occurrence of respiratory depression was also recorded.The I-D interval (the time from administration of anesthetics to delivery) and U-D interval (the time from incision of the uterus to delivery) were recorded.Results There were no significant differences in the blood gas analysis parameters in blood samples collected from the MA,UV and UA,I-D interval,U-D interval,and Apgar scores between the two groups (P＞0.05).No neonatal respiratory depression was found in both groups.In group D,CMA,CUV and CUA were 471±119,359±88 and (321±78) ng/ml,respectively,CUV/CMA was 0.76±0.06,and CUA/CUV was 0.89±0.03.Conclusion Although the metabolism of dexmedetomidine is little after easy placental transfer,dexmedetomidine has no adverse effects on the newborn during the cesarean section under general anesthesia.

Objective To observe shock injury inflicted by underwater blasts at different ranges on animals placed onboard the ship.Methods In the underwater blast experiment onboard a certain minesweeper,rabbits were used to study the damaging effects of shock inflicted by underwater blasts.Indexes of the internal organs,the skeleton system and blood were detected following underwater blasts.Results Main manifestations of shock injury were dotted or patchy hemorrhages on the surface of the lung organ,and bone fractures in a few animals.Conclusions Experimental results indicated that the animals in working condition one had moderate to severe injury,while the animals in working condition two had severe injury.

Objective To observe shock injury inflicted by underwater blasts at different ranges on animals placed onboard the ship.Methods In the underwater blast experiment onboard a certain minesweeper,rabbits were used to study the damaging effects of shock inflicted by underwater blasts.Indexes of the internal organs,the skeleton system and blood were detected following underwater blasts.Results Main manifestations of shock injury were dotted or patchy hemorrhages on the surface of the lung organ,and bone fractures in a few animals.Conclusions Experimental results indicated that the animals in working condition one had moderate to severe injury,while the animals in working condition two had severe injury.

ObjectiveTo evaluate the effect of preloading epidural space with 0.9％ sodium chloride on the incidence of the injury to blood vessel by epidural catheter insertion for cesarean section.Methods One hundred uterogestation patients with single birth,ASA class Ⅰ - Ⅱ,underwent caesarean section and requested continuous epidural analgesia were divided into group P and group C with each 50 cases by random digits table.After identification of the epidural space,group C was inserted epidural catheter directly,and 5 ml of 0.9％ sodium chloride was injected into epidural space through the epidural needle in group P,while the syringe plunger was held closed for 20 s to make sure the solution spreaded sufficiently,following insertion the epidural catheter.Between the two groups,mean arterial pressure and heart rate were recorded prior to anesthesia,2 min after turn to the supine horizontal position after succeeded puncture,the time when the fetus were born and when the surgery were over.The cases with bloody fluid in the epidural puncture needle during puncture,or in the epidural catheter during catheter placement,fresh blood in the epidural catheter,and bloody fluid in caudal end of epidural catheter during extubation were recorded.ResultsThe changes of mean arterial pressure and heart rate were all in the normal range,there was no obvious difference between the two groups.The incidence of rates with bloody fluid in the epidural puncture needle during puncture and the bloody fluid in caudal end of epidural catheter during extubation in group P were significantly lower than those in group C [ 10％ (5/50) vs.26％ (13/50),22％ (11/50) vs.48％ (24/50),P ＜ 0.05 or ＜ 0.01 ].ConclusionPreloading epidural space with 5 ml 0.9％ sodium chloride can reduce the incidence of the injury to blood vessel induced by insertion of epidural catheter.

Objective To determine the optimum dose of normal saline (NS) for preloading epidural space required to prevent the injury to blood vessel by epidural catheter placement for caesarean section.Methods Two hundred ASA Ⅰ or Ⅱ parturients with a single baby at full term in vertex presentation,aged 24-35 yr,weighing 63-78 kg,scheduled for caesarean section under continuous epidural anesthesia,were randomly divided into4 groups (n-50 each):control group (group Ⅰ),NS2 ml group (group Ⅱ),NS5 ml group (group Ⅲ)and NS 10 ml group (group Ⅳ).The epidural puncture was performed at L2-3 interspace with a Tuohy needle attached to a 5 ml syringe.Loss of resistance was used to identify the epidural space.In group C no fluid was injected into the epidural space before insertion of the catheter,while in groups Ⅱ,Ⅲ and Ⅳ NS 2,5 and 10 ml were injected into the epidural space before the catheter insertion respectively.After a test dose of 3 ml 1.5％ lidocaine,0.75％ ropivacaine 10-20 ml was administered through the epidural catheter.MAP and HR were recorded before epidural puncture (T0),at 10 and 20 min after the end of epidural administration (T1.2),and at the end of surgery (T3).The number of patients in whom blood or blood tinted fluid was withdrawn from the epidural catheter was recorded.The amount of ropivacaine consumed was recorded.The upper level of anesthesia was measured by pin-prick and the degree of motor block was assessed using modified Bromagc scale at T2.Results The hemodynamic parameters were in the normal range in the four groups.MAP was significantly lower at T2,the upper level of anesthesia was significantly higher,and the degree of motor block was significantly smaller in group Ⅳ than in groups Ⅰ,Ⅱ and Ⅲ (P ＜ 0.05).There was no significant difference in MAP among groups Ⅰ,Ⅱ and Ⅲ (P ＞ 0.05).There was no significant difference in HR and the amount of ropivacaine consumed among the four groups (P ＞ 0.05).The number of patients in whom blood or blood tinted fluid was withdrawn fiom epidural catheter was significantly smaller in groups Ⅲ and Ⅳ compared with groups Ⅰ and Ⅱ (P ＜ 0.05).Conclusion Preloading the epidural space with NS 5 ml can prevent the occurrence of injury to blood vessel induced by insertion of epidural catheter with no influence on the efficacy of anesthesia and NS 5 ml is the optimum dose.

Objective To investigate the cardiac protection of Hsp27 against endotoxic cardiac depression mediated by activation of PI3K/Akt pathway and the suppression of NFκB-mediated inflammatory response in mice. Method (1) Transgenic mice with cardiac specific overexpression of Hsp27 (Hsp27 Tg) and wild littermate controls (WT) were given 10 mg/kg LPS injected intraperitoneally to induce endotoxemia, (2) The cardiac function measurement in mice was performed by using echocardiography 6 hours after LPS treatment (n = 6), (3) The activity of PBK/Akt pathway was evaluated by Western blot for [hosphor-Akt (p-Akt) and phosphor-Gsk-3β (p-Gsk-3β) one hour after LPS administration ( n = 4)], (4) Activity of inflammatory response was evaluated by protein degradation of IκBα (n = 4), (5) The apoptosis of myocardial cells was determined by TUNEL assay on the paraffin section of cardiac tissue 24 hours after LPS exposure (n = 4). Results (1) Hsp27 attenuated cardiac dysfunction significantly following LPS treatment. Compared with the primary value, LPS induced the depression of cardiac function both in WT rats and Hsp27Tg rats. However, the cardiac dysfunction was attenuated significantly in Hsp27Tg rats compared with that in WT rats ( P < 0.01 or 0.05) . (2) Hsp27 attenuated IκBα degradation after LPS administration. Compared with the primary value, LPS led to LκBα degradation by (72.92 + 9.20) % in WT rats and by (41.43 + 24.10) % in Hsp27Tg rats. The overexpression of Hsp27 lessened the IκBα degradation significantly (P < 0.05). The similar results were obtained in rat myocardial cell culture of experiments. (3) Hsp27 enhanced the activation of PI3K/Akt signaling following LPS exposure. One hour after LPS administration, the relative levels of p-Akt and p-GSK-30 were (3.11 + 0.83) and (3.19 + 1.04), respectively in WT rats, and (5.13 + 0.73) and (5.71 + 1.20) in Hsp27Tg rats, respectively. Compared with WT rats, the levels of p-Akt and p-GSK-3β were significantly higher in Hsp27Tg rats (P < 0.05). (4) The Hsp27 lessened LPS-induced the apopto-sis of myocardial cells. Twenty-four hours after LPS treatment, the percentages of myocardial cell apoptosis were (6.46+ 1.74)% in WT rats and (2.88 + 0.91)% in Hsp27Tg rats. Compared with WT rats, LPS-induced apoptosis in myocardial cells was significantly decreased in Hsp27Tg rats (P < 0.01). Conclusions The overexpression ofHsp27 attenuates cardiac dysfunction significantly during endotoxemia, and the mechanisms may be attributed to the activation of PDK/Akt signaling pathway.

Objective To evaluate the effect of preloading the epidural space with normal saline (NS) on the incidence of injury to blood vessel by epidural catheter placement for cesarean section. Methods One hundred and fifty parturients with a single baby at full term in vertex presentation scheduled for cesarean section under continuous epidural anesthesia were randomly divided into 3 groups ( n = 50 each): Ⅰ group control; Ⅱ group NS needle attached to a 5 ml syringe. Loss of resistance was used to identify the epidural space. In group Ⅰ no fluid was injected into the epidural space before insertion of catheter; while in group Ⅱ and Ⅲ NS 5 ml with or without whom blood or blood tinted fluid was withdrawn from epidural catheter was recorded. Results The number of patients in whom blood or blood tinted fluid was withdrawn from epidural catheter was significantly lower in group Ⅱand Ⅲ than in group Ⅰ but was not significantly different between group Ⅱ and Ⅲ. Conclusion Preloading the epidural space with 5 ml NS can reduce the incidence of injury to blood vessel induced by insertion of epidural

Objective To investigate the effect of dexamethasone on the toxicity of bupivacaine in murine neurons.Methods Murine neuroblastoma cell line N2a was obtained from ATCC cell bank (USA). The cells were cultured in 10% fetal cow serum/MEM culture medium and divided into 4 groups voup I control (Con); group II bupivacaine ( Bup); group Ⅲ dexamethasone (Dex) and group IV Dex + Bup. The culture medium contained bupivacaine 900 μmol/L in group Bup and dexamethasone 1 μmol/L in group Dex respectively. In group Dex + Bup ( IV ) Bup was added to the culture medium with a final concentration of 900 μmol/L at 12 h after pretreatment with Dex 1 μmol/L. The cells were inoculated in 24 well plates (0.5 ml in each well, 24 wells in each group) and 10 cm culture dishes (7 ml in each dish, 4 dishes in each group). The release rate of LDH was calculated and the morphology of the cells and nucleus condensation (by Hoechst 3334224 fluorescent staining) was detected at 9 h of incubation in 24 well plates. The mitochondrial transmembrane potential (by JC-1 assay) and phosphorylation of Akt and ERKs (by Western blot) were measured at 5 h of incubation in 24 well plates and in culture dishes respectively. ResultsBupivacaine caused severe damage to the N2a cells as evidenced by increase in LDH release and nucleus condensation (apoptosis), dephosphorylation of Akt and ERKs, decrease in mitochondrial transmembrane potential and severe morphological changes. Dexamethasone pretreatment significantly attenuated bupivacaine-induced neurotoxicity. Conclusion Dexamethasone can protect N2a cells from bupivacaine-induced neurotoxicity through stabilization of mitochondrial transmembrane potential and inhibition of dephosphorylation of Akt and ERKs.

Objective To study the effects of heat shock proetin 27(Hsp27)on the cardiac dysfunction induced by endotoxemia.Method All experiments were performed in the geriatric lab of the First Affiliated Hospital Of Nanjing Medical University,and in the Animal Model Center of Nanjing University.The genotyping of the transgenic mice with cardiac-specific overexpression of Hsp27(Hsp27 Tg)was assayed by PCR and the expression of Hsp27 was determined by western blot.Hsp27 Tg and its wild type littermates(WT)were intraperitoneally injected with LPS(10 mg/kg),and 24 hours later,cardiac function was measured by echocardiography(n=6/group).The accumulated mice mortality was recorded within 70 hous after intraperitoneal injection of LPS(20mg/kg)(n=37/WT,n=27/Hsp27Tg).The NF-kB activity for cardiac-tissue samples was analyzed by electrophoretic mobility shift assay(ENSA)and for cell culture samples by dual-reporter gene assay(n=4/group).The comparison of multiple groups was performed by one-way analysis of variance(ANOVA),and comparison of two groups was performed by Scheffe-test.Survival curves were analyzed by the log-rank test.P＜0.05 wns considered to be significant.Results The high expression of Hsp27 exhibited in myocardium of Hsp27 Tg,whereas not in myocardium of WT.LPS significantly reduced the cardiac function both in Hsp27 Tg and WT.However,compaled with LPS-treated WT,cardiac function was more significantly improved as evidenced by the increases of EF by 27.33%and FS by 37.09%(P＜0.01 or P＜0.05).Seventy hours after LPS injection,the mortality was 11.11% in Hsp27 Tg and 37.84% in WT.Compared with WT,the survival rate of Hsp27 Tg significantly increased(P＜0.05).The NF-kB activation was significantly inhibited by Hsp27(P＜0.01 or P＜0.05).Conclusions The high cardiac-specific expression of Hsp27 significantly inhibits cardiac dysfunction induced by endotoxemia,and at the same time improve the survival rate.The mechanism may be connected with Hsp27 downregulating NF-kB-activation induced by LPS.

0.05), suggesting that clinical trial could be made for the cultured mycelia