Objective It has been shown that strong acute stress or long-term chronic stress significantly affects learning and memory. The aim of this study was to investigate the effects of chronic pain on learning and memory and morphological structure of hippocampus in neonatal rats.Methods Sixty SD rats aged 7 days were randomly divided into two groups : (A) chronic pain group ( n = 30) in which 0.5% formalin 0.1 ml was injected subcutaneously into plantar region of hind paw every day for two weeks and (B) control group (n = 30) in which the plantar region of hind paw was touched with cotton-tipped swab every day for 2 weeks instead of subcutaneous injection of formalin. Morris water maze performance was used to test learning and memory. The number of granule neurons in dentate gyrus and pyramidal neurons in CA3 were counted. Results The mean latency period in the Morris water maze intelligence test was significantly longer in chronic pain group than that in control group ( P

Objective To evaluate the feasibility and safety of using continuous spinal anesthesia (CSA) in high risk elderly patients undergoing lower abdominal or lower extremity surgery. Methods Sixty-four ASA III or IV patients aged 70-101 yr weighing 38-55 kg undergoing lower abdominal or lower extremity surgery were randomized to receive epidural anesthesia (EA) (n = 32) or CSA ( n = 32). The patients were complicated with cerebral embolism and/or hypertension, coronary artery disease and/or COPD and/or diabetes mellitus. The patients were unpremedicated. EA was performed at I2.3 or L1.2. A test dose of 2 ml of 2% lidocaine was given. When no signs of spinal block was observed, 1 % ropivacaine was given in small increments until the block height reached T6-8 . CSA was performed at L3,4 using Spinocath (B. Braun). A 2-cm catheter segment was left in subarachnoid space. 0.5% bupivacaine was given in 0.5 ml increments every 3 min until satisfactory block level was reached. The onset time of anesthesia was recorded. The degree of motor block was assessed using modified Bromage scale. Arterial blood samples were obtained before anesthesia (T0 , baseline), when satisfactory block level was reached ( T1), 1 h after skin incision (T2) and at the end of operation (T3) for determination of lactate concentration. The amount of ephedrine and innovar ( droperidol-fentanyl mixture) used during operation and the recovery of motor function of lower extremities were also recorded. Results The demographic data including sex, age, height, body weight, ASA physical status and types of operation were not significantly different between the two groups. BP and HR were significantly decreased after anesthesia as compared to the baseline values at T0 in group EA, whereas in CSA group there were no significant changes in BP and HR after anesthesia. Significantly more patients received ephedrine in EA group (98% ) than in CSA group (15%) and the mean dose of ephedrine was significantly higher in EA group [(34.5?3.1) mg] than in CSA group [(4.3?0.5) mg ]. The onset of block was significantly faster in CSA group than in EA group. Motor blockade was less intense in EA group as assessed by modified Bromage scale. Analgesia was more satisfactory in CSA group and less patients received innovar during operation in CSA group (20% ) than in EA group (51% ). The recovery of motor function of lower extremities was faster in CSA group than in EA group. Blood lactate was significantly higher at T1 , T2 , T3 in EA group than in CSA group. No late complications related to CSA was observed. Conclusion CSA is safe and effective and provides better analgesia with better hemodynamic stability and faster onset of block than EA in elderly patients.

ObjectiveTo investigate the effects of isoflurane anesthesia on the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated extracellular signal-regulated kinase (p-ERK) in neonatal rat hippocampus.MethodsForty-eight SD rats of both sexes,aged 7 days,weighing 12-17 g,were randomly divided into 2 groups ( n =24 each):control group (group C) and isoflurane anesthesia group (group Ⅰ).In group Ⅰ,the rats were exposed to2.5％ isotlurane for 3 min and then 1.5％ isoflurane was inhaled for 4 h,while in group C the rats were exposed to air for4 h.Arterial blood samples were collected immediately after anesthesia for blood gas analysis and for determination of the blood glucose concentration.Five rats in each group were sacrificed at 0,6,24 and 48 h after anesthesia (T1-4) and hippocanpi were removed for determination of the expression of potassiumchloride cotransporter 2 (KCC2),potassium-chloride cotrmsporter 1 (NKCC1),BDNF and p-ERK by Western blot.NKCC1/KCC2 ratio was calculated.ResultsAcid-base imbalance,hypoxemia and glycopenia were not found immediately after anesthesia in both groups.Compared with group C,KCC2 expression was significantly down-regulated and NKCC1/KCC2 ratio was increased at T3 and T4,and the expression of BDNF and p-ERK was dewn-regnlated at T1 and T2 in group Ⅰ (P＜0.05).There was no significant difference in NKCCI expression at each time point between groups Ⅰ and C ( P ＞ 0.05 )、ConclusionIsoflurane anesthesia delays the neuronal development in neonatal rat hippocampus through down-regulating the expression of BDNF and p-ERK.

Objective To investigate the effects of isoflurane anesthesia on proliferation and differentiation of neural stem cells (NSCs) in the dentate gyrus of neonatal rats.Methods Ten SD rats,aged 7 days,weighing 16-20 g,were randomly divided into 2 groups ( n =5 each):control group (group C) and isoflurane group (group 1) .The rats in group Ⅰ inhaled 2.5％ isoflurane for 3 min for induction and then anesthesia was maintained with 1.5 ％ isoflurane for 4 h,while the rats in group C only breathed the room air for 4 h.Bromodeoxyuridine (BrdU) 100 mg/kg was injected intraperitoneally right before the induction and after the end of administration to label NSCs and their progeny in the dentate gyrus.At 24 h after the 2nd administration of BrdU,double immunofluorescence for BrdU and NeuroD (a marker of neuroblasts and immature neurons) was used to assess NSC proliferation and neuronal differentiation.Results Compared with group C,the number of BrdU+ cells in group Ⅰ was significantly decreased,whereas the fraction of NeuroD+/BrdU+ differentiated cells was increased in the dentate gyrus( P ＜ 0.05 or 0.01 ).Conclusion Isoflurane anesthesia suppresses the proliferation of NSCs and induces neuronal differentiation of NSCs in the dentate gyrus of neonatal rats.

Objective To investigate the effect of precondition with Toll-like receptor 4 monoclonal antibody (TLR4mAb) on lipopolysaccharide (LPS) -induced acute lung injury in mice.Methods A total of 45 male BALB/c mice were randomly divided into 3 groups:the control group ( group C),the sepsis group (group S) and the pretreatment group (group P).Mice in the group P and group S were injected intraperitoneally with LPS ( 10 mg/kg) to produce acute lung injury models.Mice in the group P was injected intraperitoneally with TLR4mAb (5 μg/g) 1 h before the injection of LPS.Expression of TLR4mRNA in lung tissue,expression of TNF-α and IL-6 in serum,water content of lung,and the pathomorphologic changes of lung were detected after 6 h,12 h and 24 h.One-way ANOVA was used for inter-group comparison and two-way ANOVA was used for intra-group comparison.Results Compared to group C,water content significantly increased at 12 h and 24 h in group S and group P; compared to group S,water content significantly decreased in group P at 12 h and 24 h.Compared to group C,the expression of IL-6 and TNF-α significantly increased in group S and group P at 6 h,12 h and 24 h; compared to group S,the expression of IL-6 and TNF-α significantly decreased at 6 h,12 h and 24 h in group P.Compared to group C,the expression of TLR4 mRNA increased significantly in group S and group P at 6 h,12 h and 24 h; compared to group S,the expression of TLR4 mRNA decreased significantly in group P at6 h,12 h and 24 h.Compared to group S,pathological damage of the lung was improved significantly in group P.Conclusions Precondition with TLR4mAb can attenuate LPS-induced acute lung injury,suppress the expression of inflammatory factors.Regulation of TLR4 pathway may be a promising therapeutic strategy for ALI.

BACKGROUND:In recent years, studies on the application of traditional Chinese medicine in bone tissue engineering are stil at the initial stage in China. Reports about psoralen antibiotic biphasic ceramic bone have not been seen in bone tissue engineering research. OBJECTIVE:To fabricate the psoralen antibiotic biphasic ceramic bone by vacuum evaporator and to observe the physicochemical properties, antibiotic activity and biocompatibility of the material. METHODS:Biphasic ceramic bone was prepared by twice low-temperature calcining pig vertebrae combined with sodium pyrophosphate, and then the ceramic bone was immersed in chitosan/psoralen compound solution to prepare psoralen antibiotic biphasic ceramic bone. The surface morphology was observed by scanning electron microscope, and the compressive strength was tested. Antibiotic activity of the psoralen antibiotic biphasic ceramic bone on Escherichia coli and Staphylococcus aureus was tested by microbiological methods. Mouse osteoblasts MC3T3-E1 were co-cultured with the psoralen antibiotic biphasic ceramic bone for 4 and 8 days, and the cel adhesion and proliferation on the scaffold surface were observed under the scanning electron microscope. RESULTS AND CONCLUSION:Psoralen antibiotic biphasic ceramic bone had natural pore structure with the trabecular bone, trabecular space and lumen system and exerted great antibiotic effect on Escherichia coli and Staphylococcus aureus. The compressive strength was (4.69±0.50) MPa. Mouse osteoblasts MC3T3-E1M could be adherent to the psoralen antibiotic biphasic ceramic bone and proliferate rapidly, suggesting the psoralen antibiotic biphasic ceramic bone has good cytocompatibility.

Objective To investigate risk factors of nocturnal hypoglycemia in patients with type 2 diabetes mellitus,to seek quantitative indicators for early warning,and to evaluate the effects of intervention.Methods 24-h blood glucose of 1147 patients with type 2 diabetes mellitus with well-controlled hyperglycemia were determined by continuous glucose monitoring system (CGMS).Incidences of hypoglycemia were compared between groups with different 3 h postprandial blood glucose levels after supper.Results The rates of hypoglycemia,asymptomatic hypoglycemia,and nocturnal hypoglycemia were respectively 37.23％,22.75％,and 18.31％.Nocturnal hypoglycemia set in most frequently by 22:00-2:00 (RR =1.72,x2 =31.667,P＜0.01).The hypoglycemia incidence was reduced in intervention group than that in control group (9.67％ vs 16.76％,x2 =8.79,P ＜0.01).Conclusions Nocturnal hypoglycemia happens commonly in patients with type 2 diabetes.It usually sets in by 22:00-2:00.Appropriate intervention may prevent the hypoglycemic events.

Objective To investigate the effects of propofol on the development of spatial learning and memory and neuron proliferation of neonatal rats at different doses. Methods 60 neonatal rats were divided into four groups among per litter by using a randomized block design. Three different doses of propofol group were induced with propofol 10 mg/kg( group P10) ,50 mg/kg( group P50) or 50 mg/kg twice( group P50D) by subcutaneous injection respectively. Neuron proliferation at dentate gyrus was detected by using BrdU marker 3 days later.Morris water maze test was carried out on postnatal day 28. Escape latency,time in probe quadrant were recorded.Results Compared to the control group,neuron marked with BrdU at dentate gyrus in group P50D was significantly decreased( (840±76) vs (225 ±66), P＜0.05) ,group P10 was significantly increased( (840 ±76) vs ( 1225± 154), P＜0.05). Compared to the control group,latency of group P50D was significantly increased( ( 15.12 ±3.43 ) s vs (42.68 ± 6. 18 ) s, P ＜ 0. 05 ), time in probe quadrant of group P50D were significantly decreased ( ( 55.66 ± 8.57 ) s vs (32. 18 ± 5. 38 ) s, P＜ 0. 05 ). Compared to the control group, there was no significant difference between group P50 and group P10. Conclusion Propofol given to seven-day-old rats with 50 mg/kg twice by subcutaneous injection suppresses neuron proliferation and impairs development of memory and learning in neonatal rats,but propofol given with 10 mg/kg once promotes neuron proliferation.

Objective To investigate the effects of different concentrations of isoflurane on the caspase-3 expression in the hippocampus and S100β level of plasma in fetal rats. Methods 18 pregnant rats at gestational day 21 were divided into control group, 1. 3% isoflurane group,3% isoflurane group. Rats in the control group spontaneously breathed 100% oxygen for 1 h. Rats in the treatment groups breathed 1.3% or 3% isoflurane in 100% oxygen through an endotracheal tube, with mechanical ventilation for 1 h. Rat pups were delivered by cesarean section 6 h after treatment, and fetal blood was sampled from the left ventricle of each fetal heart and evaluated for S100β. Fetal brains were then evaluated for apoptosis, using caspase-3 immunohistochemistry in the CA1 region of the hippocampus. Results Compared to the control group ((1. 48 ± 0. 08) μg/L) and the 1. 3% isoflurane group( (1.53 ±0. 12)μg/L) ,the 3% isoflurane group showed significantly higher level of S100β( (3. 12 ±0. 15) μg/L, P＜0.05) . There was no differences in densities of caspase-3-positive cells between the control ((33 ±4) cell/mm ) and 1.3% isoflurane groups((31 ±5)cell/mm2). Compared to 1.3% isoflurane,isoflurane at a concentration of 3%((75 ± 7) cell/mm2, P＜0.05) for lh increased neurodegeneration in the hippocampal CA1 area in the developing brain of fetal rats. Conclusion Isoflurane can dose-dependently induce brain damage. Isoflurane at a concentration of 3% for lh can induce apoptosis in the hippocampal CA1 area and increase S100β levels of fetal rats.

Objective To evaluate the role of protein kinase C (PKC) in reduction of hypoxia-reoxygenation (H/R) injury by hypoxic preconditioning or norepinephrine preconditioning in cultured neonatal rat cardiomyocytes. Methods Primary cultured neonatal rat cardiomyocytes were randomly divided into 6 groups (n = 25 each): control group (group Ⅰ), H/R group (group Ⅱ), hypoxia preconditioning group (group Ⅲ), norepinephrine preconditioning group (group Ⅳ), H7 + hypoxia preconditioning group (group Ⅴ) and H7 + norepinephrine preconditioning group (group Ⅵ). In group Ⅱ , the cardiomyocytes were exposed to 3 h of hypoxia followed by 1 h of reoxygenation. In group Ⅲ, the cells were subjected to 20 min of hypoxia followed by 20 min of reoxygenation before H/R. Norepinephrine was added to the culture medium with a final concentration of 10- 7 mol/L,and then the cells were cultured for 30 min before H/R in group Ⅳ. H7 was added to the culture medium with a final concentration of 5 × 10-5 mol/L, the cells were then cultured for 10 min, and the following procedures before H/R were the same as thase described in group Ⅴ . H7 was added to the culture medium with a final concentration of 5 × 10-5 mol/L, the cells were then cultured for 10 min, and the following procedures were the same as those described in group Ⅵ. The cell survival rate, the activities of LDH and CK in the supernatant, and the content of MDA and activity of SOD in cardiomyocytes were determined. Results The cell survival rate and activity of SOD were significantly lower, while the LDH and CK activities and MDA content higher in group Ⅱ than in group Ⅰ ,in group Ⅴ than in group Ⅲ, and in group Ⅵ than in group Ⅳ (P ＜ 0.01). The cell survival rate and activity of SOD were significantly increased, while the LDH and CK activities and MDA content decreased in group Ⅲ and Ⅳ compared with group Ⅱ (P＜0.01).Conclusion The activiation of PKC is involved in the reduction of H/R injury by hypoxic preconditioning or norepinephrine preconditioning in cultured neonatal rat cardiomyocytes.