Objective To estimate the ethology representation of the modified model of chronic cerebral hypoperfusion ( m-3VO) , created by occluding bolh common carotid in combination with one vertebral artey. Methods Rats were randomly put into m-3VO group,2VO group,and sham group ,and were subjected to the matching operation. Eight weeks after the operation, Morris water maze,open field test,and forced swimming lest were carried out. Results Compared with the sham group[ (18.46 ± 2. 63)s, (15. 9 ± 2. 16)s] .escape latencies of Morris water maze of m-3VO group [ ( 37. 69 ± 5. 11 ) s, ( 32. 55 ± 4. 28 ) s] and 2V0 group [ (42. 94 ± 3.05)s, (37.43 ± 4. 55)s] in the fourth and fifth days significantly increased (t = 3. 61 , P<0. 01 ; l = 3. 028, P<0.05 ; t = 4.72, P< 0. 001 ; t = 4. 153, P<0.001). The time of m-3VO group[ (7. 72 ± 1. 92) s] and 2VO group[ (7. 154 ± 2.66)s] spent in NE square was also longer than that of the sham group[(11. 19 ± 2. 137)s] (q = 2.98, P< 0.05; q = 3.81 , P< 0.01 ). And the crossing score of open field test of 2VO group(83. 25 ± 13. 53) was higher than that of the sham group (55. 6 ± 16. 8) ( q = 3. 27, P < 0. 01 ) , but immobility times, swimming times and climbing times of forced swimming test were not different between the three groups (P>0. 05). Conclusion The spatial learning ability of m-3V0 group rats are impaired 8 weeks after the operation, which is similar to that of 2VO group rats,and the m-3V0 operation have few effect on exploring ability and depression of rats.

Objective To observe the effect of resveratrol on cognitive impairment in rats after chronic cerebral hypoperfusion,and to explore the underlying antioxidant mechanism of resveratrol.Methods The chronic cerebral hypoperfusion model was induced by permanent occlusion of bilateral common carotid arteries (2VO) in rats.Healthy male Wistar rats were randomly divided into 3 groups:sham-operated group,2VO group and 2VO+resveratrol group.Spatial learning and memory were assessed using the Morris water maze at 4 weeks after the occlusion.The levels of 4-Hydroxynonenal (4-HNE) and 8-Hydroxy-2′-deoxyguanosine (8-OHdG) in the cortex and hippocampal CA1 areas were detected using immunohistochemistry staining,for reflecting the lipid peroxidation and oxidative DNA damage.Results The escape latencies from the third day to the fifth day were longer in 2VO group than in sham-operated group[(42.1+5.4)s vs.(25.1±3.3)s,(36.4±4.4)s vs.(12.4±3.3) s,(30.4±4.0)s vs.(8.1±3.4)s,q=10.91、14.54 and 14.07,all P ＜0.01],while the time spent in the object square was shorter in 2VO group than in sham-operated group[(12.9+2.5)s vs.(18.9+2.2)s,q=6.47,P＜0.01].Compared with 2VO group,the escape latencies in 2VO+resveratrol group from the third day to the fifth day were shorter[(29.5+4.0)s,(25.6±4.3)s and (19.8±4.2)s,q=7.71,6.22 and 6.37,all P＜0.01],while the time spent in the object square was longer[(16.5±1.8)s,q=3.83,P＜0.05].Compared with the shamoperated group,the mean integral optical density (IOD) of 4-HNE and 8-OHdG in the cortex and hippocampus CA1 area were increased in 2VO group (265.1 + 9.0 vs.168.2 + 6.0,37.8 + 5.0 vs.24.0+4.0,q=31.89 and 7.48,both P＜0.01).And in the 2VO+resveratrol group,the mean IOD of 4-HNE and 8-OHdG in the cortex and 8-OHdG in hippocampus CA1 area were lower than in 2VO group (195.1±7.0,26.0±4.3,q=23.03 and 6.49,both P＜0.01).Conclusions Resveratrol can improve the cognitive impairment in rats after chronic cerebral hypoperfusion,which may be related to preventing oxidative damage.

ObjectiveTo observe the effects of enriched environment on depressive-like behaviors induced by chronic stress in rats.MethodsAdult rats were randomly divided into stress group and the control group,then after 21 days of stress,rats were raised in an enrich environment (EE) or standard environment (SE)for 28 days.Open field test,forced swimming test and sucrose preference test were used to detect depressive-like behavior in rats.Results ( 1 ) Open field test showed that grid crossing,standing and rearing in stress ( no gap)rats were significantly reduced ( 13.88 ±4.38 vs 45.00 ± 10.19,9.13 ±2.54 vs 16.38 ±4.11 and 4.78 ± 1.39vs 10.51 ± 2.52 ; n =8 ; P＜ 0.01 respectively) ; but grid crossing and standing in stress + EE rats were significantly increased than stress + SE rats (41.61 ± 10.53 vs 26.25 ± 6.18 and 16.79 ± 3.49 vs 11.25 ± 3.12 ; n =8 ; P＜0.01 and P＜0.05 respectively).(2) Sucrose preference tests showed that sucrose consumption and sucrose preference％ in stress ( no gap) rats were significantly decreased than those in the control group ( 5.22 ± 0.94 vs 10.61 ±2.59 and (49.11 ±6.77)％ vs(63.38 ±8.36)％ ; n=8; P＜0.01 respectively).(3) Forced swimming test showed that immobility time was increased in stress ( no gap) rats ( ( 19.5 ± 5.43 ) s vs ( 12.75 ± 3.9 ) s; n =8 ; P ＜ 0.05 ) and was restored by EE compared to SE rats ( ( 10.25 ± 3.57) s vs ( 17.75 ± 5.45 ) s; n =8 ; P ＜ 0.05).ConclusionChronic stress can reduce depressive-like behaviors,and EE can restore depressive-like behaviors induced by chronic stress.

Objective To explore the the cellular damage of hippocampus neuron in a rat model of chronic cerebral hypoperfusion. Methods Rat model of chronic cerebral hypoperfusion was established by permanent bilateral common carotid arteries occlusion (2VO). Eight weeks after the operation,the brains were removed and examined with histological stains, electron microscope, flow cytometer and Western Blotting. Results Compared with the control group,the arrangement of hippocampus neurons in 2VO rats appeared to be more irregular, and the number of the neurons decreased partly ( CA2: ( 34.75 ± 3.40) vs (49.25 ± 9.67 ), P ＜ 0. 05; DG: ( 73.50 ± 9.26)vs ( 90.75 ± 4.35 ), P ＜ 0. 05 ). By electron microscopic study of hippocampus neurons in 2VO rats, the nuclei became smaller and the heterochromatin assembled in the border of the nuclei in some neurons, while cytoplasm swelled,especially in mitochondria and endoplasmic reticulum. The rate of apoptosis of hippocampus neurons in 2VO rats( (9. 117 ±2. 540)% ) ,detected by the flow cytometer,was higher than that of sham group( (4. 750 ±3.481 ) % ) (P ＜ 0. 05 ). The expression of pro-caspase-3 in hippocampus of 2 VO rats was not altered significantly compared with the control group(P ＞ 0. 05 ). Conclusion The cellular damage of hippocampus neuron in 2VO rats was mainly caused by apoptosis.

Objective To analysis the biomechanical properties of four-rod fixation system for lumbosacral reconstruction after sacrectomy.Methods Two finite element models of lumbosacral area were established according to pelvic CT images:a subtotal saerectomy model and a total sacrectomy model.The range of motion of L3 vertebral body and max yon Mise stress of instruments of a novel four-rod fixation system were evaluated and compared with those of modified Galveston technique(MGT)under conditions of veaebral body and max von Mise stress of instruments of the four-rod fixation system were evaluated and compared with those of MGT under vertical compression.Results In subtotal sacreetomy model,the range of motion of L3 vertebral body in the four-rod fixation system were 4.2 mm,0.49°,0.49°,0.24°and 0.26°compared to 5.5 mm.0.74°,0.74°,0.27°and 0.30°in the MGT.The max von Mise stress of instruments in the four-rod fixation system were 810.7,148.0,148.0,134.6 and 14.4 MPa,compared to 655.0,109.9,109.9,119.1 and 11.4 MPa in the MGT.In total sacrectomy model under veaical compression,the range of motion of L3 vertebral body and max van Mise stress of instruments in the four-rod fixation system were 10.9mm and 2172 MPa compared to 49.1 mm and 4325 MPa in the MGT.Conclnsion Comparing with the MGT.the four-rod fixation system was stiffer and showed a significant increase in the stability of lumbosacral area.When total sacrectomy without bone graft were performed,the max stress of the four-rod fixation system was much lower than that of the MGT,which means smaller risk of instrument failure.When subtotal sacrectomy or bone graft were performed,despite better stability,the higher stress shielding-effect of the four-rod fixation svstem might be unfavorable for bone fusion,which still need to be evaluated by clinical trials.

Objective To get more diagnostic informa ti on from the acute cerebral infarct, We used1HMRS and TCD to investigate the r elationship between the metabolites in the infarct, the infarct volume, blood f low velocity and blood flow to the infarct, and the clinical neurologic deficit. MethodsFifteen patients with acute cerebral infarct underwent1HMRS and TCD examinations. Clinical neurologic deficit score was c ollected from every patient record at the time of the1HMRS and TCD study. Inf arct volume (V/ml) was determined with machine software automatically. A PRESS a cquisition was used for1HMRS. The peak areas of N,Lac,Cr,Cho in the lesi on region were compared with those in the contralateral side. TCD was performed for measuring Vs, Vm of encephalic blood vessels on both sides, and the responsi ble cerebral blood flow was estimated by Vs. ResultsT here were significant decrease of N,Cr,Vm and ECBF in the lesion region when c ompared with the contralateral side( P

Objective To evaluate the hinged external flxator in combination with internal fixation for treatment of old type B fractures of the distal humerus.Methods Eleven cases of old type B fractures of distal humerus treated in our department were studied retrospectively.They were treated with hinged external fixators in combination with internal fixation and evaluated according to Mayo elbow performance scores.Results All the patients were followed up for 10 to 18(mean, 12.5)months.The mean union time was 4.6(range, 3.5 to 6.0)months.The final range of flexion to extension of the elbow was 19.4°±6.5° to 124.2°±11.3°.The final ranges of pronation and supination were 72.8°±5.4° and 67.6°± 7.3°.By Mayo elbow performance scores, the post-operative functional outcome of the elbow was excellent in 5 patients, good in 4, and fair in 2.Conclusion The old type B fractures of distal humerus can be effectively treated with hinged external fixators in combination with internal fixation, for early rehabilitation and restoration of the elbow function can be facilitated.

Objective To observe effect of environmental enrichment on the learning and memory ability and the expressions of hypoxia inducible factor 1α (HIF-1a) and vascular endothelial growth factor (VEGF) in rats with chronic cerebral hypoperfusion.Methods A total of 40 rats were randomly divided into 3 groups: bilateral vascular occlusion (2VO) of the common carotid arteries group (n=14, 2VO group), 2VO + enriched environment (EE) group (n=14, 2VO+EE group) and sham group (n=12, SHAM group).Morris water maze, novel object recognition test, real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), immunohistochemistry methods and Western blotting were used to detect changes in learning and memory ability of rats and HIF-1α and VEGF expression levels in hippocampus.Results Morris water maze showed that the escape latency was longer in the 2VO group than in the SHAM group at 3, 4 and 5 day during the training (all P＜0.05), while the 2VO+EE group spent significantly less time in finding the platform as compared with the 2VO group at 4 and 5 day (both P＜0.05).The time for space exploration in target quadrant was less in 2VO group than in SHAM group (P＜0.05), while it was longer in 2VO +EE group than in 2VO group (P＜0.05).Novel object recognition test showed that the 2VO operation impaired the priority index (PI) of time spending at exploring the novel object (P＜0.05), and environmental enrichment could improve the PI in 2VO group (P＜0.05).The real-time RT-PCR and Western blotting showed that the HIF-1α mRNA expression was higher in 2VO group than in SHAM group (P＜0.05).The VEGF mRNA and protein expressions were higher in 2VO+EE group than in 2VO group (both P＜0.05).The expression of HIF-1α in hippocampal CA1 area was higher in 2VO group than in SHAM group (P＜0.05).Conclusions Environmental enrichment can alleviate the damages of spatial and non-spatial learning and memory ability which are caused by chronic cerebral hypoperfusion.And HIF-1α and its downstream gene VEGF may be involved in the restoration of cognitive function by enriched environment.

Objective To investigate the risk factors for nosocomial bacteremia and decrease the prevalence of nosocomial bacteremia.Methods We collected the data of bacteremia patients in our hospital from January,2006 to December,2009.According to the criterion of nosocomial infection,the patients were divided into nosocomial bacteremia group (83) and community-onset bacteremia group (119).The influence of a series of variables on the development on both types of bacteremia was analyzed by Student＇s t test and x2 test.The risk factors were performed using multivariate logistic regression.Results Compared to that of community-onset bacteremia group,the proportion of malignancy (21/83 vs 12/119,x2 =8.2846,P ＜ 0.01 ),venous catheter ( 28/83 vs 3/119,x2 =36.67,P ＜ 0.01 ),diabetes ( 37/83 vs 0/119,x2 =68.226,P ＜0.05),surgical operation(37/83 vs 0/119,x2 =68.226,P ＜0.01),previous antibiotics(78/83 vs 10/119,x2 =173.5657,P ＜ 0.01 ) in nosocomial bacteremia group were higher.Multivariable logistic regression analysis showed that only 4 factors were significantly and independently responsible for nosocomial bacteremia,They were malignancy ( P ＜ 0.05,OR =3.186),diabetes ( P ＜0.001,OR =4.821 ),venous catheter( P ＜ 0.05,OR =2.135),previous antibiotics ( P ＜ 0.05,OR =2.135 ).The bacteria in nosocomial bacteremia group showed more ability to resist to antibiotics.Conclusions We should pay more attention to the patients with diabetes or malignancy or venous catheter or previous treated with antibiotics.These patients have more chances to develop to nosocomial bacteremia and infect by the drug-resistant bacteria.

Objective To study the biochemical alterations in rat brain under chronic cerebral ischemia by means of 1H and 31 P magnetic resonance spectroscopy (MRS) Methods Chronic cerebral ischemia was induced by permanent bilateral commom carotid artery occlusion (2 VO)in the regions of the hippocampal CA1 area and the whole brain. Results In vivo 1H MRS did not reveal any significant change in the concentrations of N acetyl aspartate (NAA) and Lactate (Lac) in the hippocampal CA1 region 31 P MRS in the whole brain showed an elevation of phosphomonoesters (PME). The ratio of PME/(PME+PDE) was 0 54?0 03 in sham group and 0 69?0 02 in 2 VO group ( P