Animals ; Evoked Potentials, Motor ; physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Spinal Cord ; physiology

OBJECTIVETo compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes.

METHODSSix specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire.

RESULTSThe strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05).

CONCLUSIONSThe fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

Atlanto-Axial Joint ; physiopathology ; surgery ; Biomechanical Phenomena ; Bone Wires ; Cadaver ; Humans ; Internal Fixators ; Joint Instability ; physiopathology ; surgery ; Orthopedic Fixation Devices

Objective To explore the effect of hypoxic preconditioning on the activity and gene expressions of glu-cose transporters in the cultured rat hippocampal neurons and astrocytes under anoxic condition. Methods The cultured rat hippocampal neurons and astrocytes were treated for 6 days by intermittently exposing to hypoxic gas mixture (1% O_2, 10% CO_2, 89% N_2) for20 min each day. 24 h after the last hypoxic exposure, the cells were exposed to anoxic gas mixture (10% CO_2, 90% N_2) for 6 h, and the uptake rate of [~3H]-2-deoxyglucose (2-DG), the levels of glucose transporter GLUT1 and GLUT3 mRNAs and the cell survival rate were examined im-mediately after anoxic exposure. Results Neurons and astrocytes preconditioned with hypoxia showed higher 2-DG uptake rates and increased expressions of GLUT 1 mRNA in the astrocytes and GLUT 1 and GLUT 3 mRNA in the neurons. The preconditioned neurons also showed an increased tolerance to anoxia. Conclusion Hypoxic precon-ditioning up-regulates the activity and gene expressions of glucose transporters of hippocampal neurons and astro-cytes under anoxic condition.

Objective To observe the expressions of bone morphogenetic protein-2(BMP-2)and bone morphogenetie protein-7(BMP-7)in the synovial tissue of fluorosis rats and its correlation with pathogenic mechanism of fluorosis arthritis.Methods Thirty-two SD rats were randomly divided into 4 groups:the control group,low,moderate and high-dose fluoride group.The control group ate commou fodder.The low,moderate and high dose fluoride group were fed with fodder composed of 25%.35%and 68%of corn(containing fluorine of 148.00 mg/kg)in chronic endemic fluorosis region in Guizhou Province.After 140 days,the expressions of BMP-2 and BMP-7 protein were determined by immunohistochemistry and assayed the absorbanee by computer image-pattern analysis system.Light microscope was used to observe the synovial tissue by Hematoxin Eosin,and calculated the pathological integral of synovium according to pathological grade standard.Results The expressions of BMP-2 (32.50±2.73)and BMP-7(38.90±2.56)in the control group was spare.Compared with the control group,the expressions of BMP-2(59.43±5.12,79.82±6.41,101.76±7.56)and BMP-7(55.10±4.82,78.42±5.61,98.46± 6.05)in the synovial tissue was up-regulated in each experimental groups(P＜0.05),especially in the moderate dose and the high-dose groups(P＜0.05).Compared with the control group(0.54±0.21).the pathological integral of synovium increased(P＜0.05)in each experimental groups(1.04±0.98,4.69±1.28,8.60±2.07).The expressions of BMP-2 and BMP-7 in the synovial tissue was found to be positively related with the pathological integral of synovium(r=0.98,0.99,P＜0.05).Conclusion The BMP-2 and BMP-7 play an important role in the development of fluorosis arthritis,probably by affecting osteogenesis.

Objective To evaluate the solute clearance characteristics of REXEEDTM series dialyzers during high-flux dialysis, and explore the care characteristics. Methods A randomized crossover study of 3×3 Latin square was designed based on different dialyzers. Eighteen patients with regular hemodialysis underwent dialysis with REXEEDTM-15AC dialyzer, REXEEDTM-15UC dialyzer and controlled APS-15U dialyzer, respectively. Blood samples were obtained from the blood flow entrance and exit of dialyzers, levels of urea nitrogen, creatinine, phosphate and β2-microglobulin were detected, and solute clearance rates were calculated. Before and after the third dialysis with each dialyzer, blood samples were obtained to measure the levels of urea nitrogen and creatinine, and the rates of decrease were calculated. The vital signs of each patient were intensively observed, and the venous pressure and transmembrane pressure were monitored from the dialyzers. Results The urea nitrogen clearance rates of REXEEDTM-15AC dialyzer and REXEEDTM-15UC dialyzer were significantly higher than that of APS-15U dialyzer (P<0.05). The creatinine clearance rate of REXEEDTM-15AC dialyzer was significantly higher than that of APS-15U dialyzer(P<0.05). There was no significant difference in the rate of decrease in blood urea nitrogen among different dialyzers of the same patient(>65 % for all patients). The vital signs were stable with no adverse events during dialysis, and there was no abnormal findings in laboratory security parameters. Conclusion REXEEDTM series dialyzers are effective and safe for clinical application. Great importance should be attached to the complaints from patients during dialysis. For those with less ultrafiltration, fluid as well as uhrafiltration should be supplemented to increase the transmembrane pressure.

AIMStudy on the relationship between the degraded spinal cord injuries and the changes of the motor evoked potentials (MEP) to prove the diagnosis and prognosis value of MEP.

METHODSAfter injury at T8-T9 cord using modified Allen's weight-drop method, 27 male SD rats were divided randomly into control group (n = 5), group A (50 gcf, n = 8), group B (70 gcf, n = 8) and group C (100 gcf, n = 6). MEPs elicited by monopolar transcortical stimulation were recorded continuously before injury, just after injury, 15 minutes, 1 hour, 3 hours and 6 hours after injury. The rate of the size of the bleeding or necrosis area to the total cord was also calculated.

RESULTSMEP had no significant change in the control group. The amplitude of MEP's early components in group A or group B decreased or even obliterated after SCI, and then partially recovered, while the late components were lost without any recovery signals. All animals in group C showed no MEP waves excepting 2 rats had recovery signals. The size of the cord injuries area increased according to the dropping force and was correlated significantly with the amplitude of the largest peaks of scMEP 1 hour after SCI (r = -0.821).

CONCLUSIONThe scMEP changes after SCI are correlated with the injury forces and the pathological changes in the cord, which indicates that scMEP can be used as an objective index for the cord functional monitoring.

Animals ; Electric Stimulation ; Evoked Potentials, Motor ; physiology ; Male ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; pathology ; physiopathology

A field trial was carried out to study the influence of different kinds of spring topdressing on growth, yield and quality of Ligusticum chuanxiong. The results showed that the spring topdressing had effects of improving root length, tiller numbers and plant height to some extent. At the same time the chlorophyll content and dry weight accumulation especially the dry weight of root increased significantly. It also showed that the yield increased and quality was improved significantly. The effect of different treatment with urea58.7 kg x hm(-2)(N 27 kg x hm(-2)) was the best and the treatment with N,P,K the second.
Alkaloids ; metabolism ; Coumaric Acids ; metabolism ; Fertilizers ; Ligusticum ; growth & development ; metabolism ; Seasons

Objective To determine the value and the optimal cutoff point of waist circumference (WC) in screening diabetes mellitus (DM) and to provide evidence for DM prevention and identifying population at risk in mid-western rural areas of Shandong province.Methods A sample consisting 16 341 rural residents was selected and studied.All participants were physically examined on height,weight,WC and fasting plasma glucose (FPG).Oral glucose tolerance test (OGTT) was performed for subjects with FPG valued from 6.1 to 7.0 mmol/L.DM was defined according to the criteria set by WHO in 1999.Area under the curve (AUC),sensitivity,specificity and Youden index were computed based on the receiver operating characteristic (ROC) curve analysis.Optimal cutoff point was determined by the maximum of Youden index.Results The prevalence rates of DM for males and females increased along with the rise of WC (trend test X2=72.01,122.65,P＜0.01 ).It appeared significantly higher in those with WC 85 cm in females and≥80 cm in males,with those WC ＜85 cm for females and ＜80 cm for males,in particular.AUCs were 0.639 and 0.655 for males and females respectively and both had significant differences (t=7.22,11.07,P ＜0.01 ).However,the AUCs did not show significant difference (t=0.70,P ＞ 0.05) between males and females.The Youden index reached maximum when WC approached 85 cm for females (24.90%) and 80 cm for males (24.39%).The sensitivity and specificity were 58.04%and 66.86%for males,and 67.08%and 57.31%for females.Conclusion WC seemed to be an effective indicator for screening the DM.The optimal cutoff point of WC would be 85 cm for females and 80 cm for males in screening DM and defining the population at risk in this area.

Objective To study the bone biomechanics of the rabbit osteoporosis models induced by dexamethasone sodium phosphate injection (DX) using a combined treatment modality of 99Tc-MDP and GuKangLing.Methods Rabbits were intramuscularly injected with DX (2 mg/kg) twice a week for 6 weeks.The animal osteoporosis model group (Group C) and normal group (Group A) were compared to confirm the model was available.Another control group (Group B),the osteoporosis control group (Group D) were set for the comparison at the end of the experiment.The 99Tc-MDP therapy group (Group E),GuKangLing therapy group (Group F) and 99Tc-MDP plus GuKangLing therapy group (Group G) were included in the study.The treatment lasted for 16 weeks.The bone biomechanics,cytopathology bone histomorphology,bone mineral density (BMD),X-ray,CT,bone scintigraphy and serum bone alkaline phosphatase (BALP)and P (bone gla protein) were chosen as the markers or methods to evaluate the treatment results (excellent,effective and invalid).The analysis of variance (ANOVA) and t-test were used for group comparison analysis.Results Cytopathology result indicated that there was no bone trabecula destruction in Group A.However,there was distinct bone destruction in Group C.The bone biomechanics (left femur head (265.914 ±52.773) N,L4(369.671 ±94.919) N),BMD(left femur (0.238 ±0.016) g/cm2,L4(0.236 ±0.016) g/cm2)and bone histomorphology ( (66.230 ± 10.848) ％ ) in Group C reduced clearly as compared with Group A ((405.343±55.410) N,(750.870±53.718) N,(0.294±0.017) g/cm2,(0.302±0.023) g/cm2,( 131.500 ± 21.846) ％ ) ( t ≥4.550,all P ＜ 0.01 ).Radionuclide bone scan also showed that the uptake of tracers was higher by the main arthrosis in Group C than that in Group A.Vertebra was not clearly visualized on bone scan image.There were significant differences between Group A and Group C in serum BALP and P ((45.000±7.303) vs (12.485 ±1.512) U/L,(0.168±0.018) vs (0.115 ±0.017) μg/L,t =4.126,5.476,both P ＜ 0.01 ),which indicated that the animal osteoporosis model was available.The pathological results showed an improved recovery of bone structure and trabecular in Groups E and G,but a worse recovery in Group F.Biomechanics result in Groups E and G (left femur head (386.457 ±77.077) N and (432.771 ± 17.525) N,L4(649.550 ± 126.859) N and (655.443 ±76.555) N) improved apparently,which were similar to Group B.The radiotracer uptake in Group F was lower than that in group D.The bone biomechanics,bone histomorphology,BMD,serum BALP and P after the treatment showed significant differences in Groups E,F and G (F:8.556 - 31.608,all P＜0.01 ),and the bone biomechanics result in Group G was a little better than that in Group E (t =2.625,P ＜ 0.05 ).The results of Group G and E were considered as excellent,and Group F was considered as effective.Conclusions The treatment of 99Tc-MDP combined with GuKangLing could improve the bone biomechanics of rabbit osteoporosis models and may be a potential method to increase the bone strength for resisting external force.

Objective: To investigate the long-term outcome of anterior decompression and bone graft fusion for cervical spondylotic myelopathy(CSM) and factors affecting the outcome. Methods: Two hundred and forty-five patients with CSM were treated with anterior cervical decompression and auto iliac bone graft fusion, of whom 31 had a second operation between 4 months and 2 years after operation. Follow-up studies were carried out within 5 to 15 years after operation, averaging 6.8 years. Results: Function evaluation: excellent in 118 cases (48.16%), good in 71 (28.98%), passable in 35 (14.29%) and poor in 21 (8.57%). According to the 40 points score method, there was an average of 8 point increase in all cases, of which 101 were between 36 to 40 points, 54 between 31 to 35 points. Conclusion: The long-term outcome of surgical treatment for CSM is definite. Significant factors affecting the outcome include timing of operation, degree of pathology and technique of surgery.