Cytokinesis ; Micronucleus Tests

Objective To evaluate the feasibility and principle of direct reduction and fixation through the pedicle of fractured vertebra in treatment of thoracolumbar burst fractures.Methods Between June 2001 and November 2005,24 cases of one level thoracolumbar burst fracture,16 males and eight females,were treated in our department.Their average age was 32.5 years old.The fractured vertebrae were as follows:T11 in two cases,T12 in nine cases,L1 in 11 cases and L2 in two cases.According to the ASIA(American Spinal Injury Association) neurological function grading system,there were one grade A,two grade B,five grade C,three grade D anti 13 grade E.The vertebral canal area blocked was rated as gradeⅠ(＜1/4)in three cases,gradeⅡ(1/4～1/2)in nine cases,gradeⅢ(1/2～3/4)in 10 cases and gradeⅣ(＞3/4)in two cases.The pedicle-screws were im- planted into the pedicles of the fractured vertebra and its adjacent ones.The connective rod was pre-bent according to the normal sagittal curvature of the fixation segment.After necessary decompression of the vertebral canal,the pedicle-screws stabilized the rod which was rotated to prop open upper and lower pedicle screws and push the burst vertebra so that the kyphosis and lateral dislocation were corrected.The graft bone was implanted between the transverse processes.Results On average,the height of fractured vertebra was restored from 48.3% of the normal value before operation to 93.6% after operation,the lateral dislocation from 17.1% to 0.6%,the Cobb's angle on the sagittal plane from 26.5?to 3.1?,and the Cobb's angle on the frontal plane from 9.5?to 0?.The area of vertebral canal was enlarged from 44.6% of the normal value to 92.1%.There were no complications.For in- complete neurological injuries,improvement of one to two grades was made in neurological functions.Conclusion Direct reduction and fixation through pedicles of fractured vertebrae is a safe and effective therapeutic option to treat the thoracolumbar burst fracture,for it can improve the stabilization and stress distribution.

Objective To evaluate the safety and diagnostic accuracy of preoperative endoscopic ultrasound-guid﹣ed fine-needle aspiration in patients with pancreatic cancer. Methods 256 patients with pancreatic cancer from Jan﹣uary 2010 to December 2014, 82 were considered resectable on the basis of cross-sectional imaging findings. Of these patients, 54 underwent EUS-FNA before surgery (FNA+group) and 28 underwent surgery without preoperative EUS-FNA (FNA- group), the diagnosis result of EUS-FNA and the survival time of the two groups were observed. Results All 54 lesions were visible on EUS, and all 54 attempts at FNA were technically successful. The diagnostic accuracy according to cytology and histology findings was 94.44 % (51/54) and 88.89% (48/54), respectively, and the total accuracy was 94.44 % (51/54). Two patients developed mild pancreatitis and two hemorrhage after EUS-FNA but were successfully treated by conservative therapy. No severe complications occurred after EUS-FNA. In the FNA+and FNA- groups, the median relapse-free survival (RFS) was 282 and 265 d, respectively (P>0.05), and the median overall survival (OS) was 568 and 557 d, respectively (P>0.05). RFS and OS were therefore not inferior in the FNA+group. These data indicate that the usage of EUS-FNA did not influence RFS or OS, nor did it increase the risk of other complications. Conclusions Preoperative EUS-FNA is a safe and accurate diagnostic method.

Objective To evaluate the applicant effect of improved flushing suction method for SpyClass choledochoscope operation. Methods Seventy-three patients who underwent SpyGlass choledocho-scopy from February 2013 to January 2015 were enrolled. Negative pressure biopsy channel was used in group A(n= 34)during conducting SpyGlass choledochoscopy with the tube directly connected to the conveying pipe and combined with duodenoscope suction.In group B(n= 39),the biopsy channel of disposable syringe jacket was first connected to a delivery catheter,then the negative pressure pipe was put in the injector coat, combined with duodenoscope suction. Adverse reactions,theⅠ image acquisition time after the placement of SpyGlass delivery catheter to pancreaticobiliary duct,the total operation time,and the occurrence of compli-cations after operation were recorded. Results Sinus bradycardia,arrhythmia,agitation occurred in 7 cases (20. 6%),5 cases( 14. 7%),and 10 cases( 29. 4%) respectively in group A,those were 1 case (2. 6%),0 case(0/ 39),2 cases(5. 1%)respectively in group B with significant difference(P<0. 05). The time to acquire a clear image and the total operation time in group A were 6. 2 min and 24. 9 min,and 3. 3 min and 16. 8 minutes in B group with significant difference(P<0. 05),postoperative cholangitis oc-curred in 5 cases in group A(14. 7%),1 case(2. 6%)in group B with significant difference(P<0. 05). Conclusion New irrigation and suction method has obvious advantages in the SpyGlass system.

Objective To compare the success rate, operation time, complication rate and the degree of tolerance of two kinds of endoscopic placement of small intestine decompression tube. Method 68 intestinal obstruction patients treated with transnasal ileus tube were randomly divided into 2 groups, group A and group B, 34 cases in each. Patients in group A were treated by endoscopic placement, while in group B placement was guided by nasal endoscope. Results The catheterization success rate and complications between the two groups have no statistical significance (P > 0.05) while the differences of catheter operation time (P < 0.05) and placement tolerance (P < 0.01) have statistical significance. Conclusion Endoscopic placement of small intestinal decompression tube has clinical application value while placement guided by nasal endoscope has certain advantages.

Objective To analyze and evaluate the characteristics of enzyme kinetics of CTX-M-14 type extended-spectrum β-lactamase(ESBL) with Pro167 residue substitution. Methods By molecular cloning and PCR techniques, CTX-M-14 gene was directionally cloned into plasmid pET28a( + ) from a clinical E. coli isolate and formed an expression vector to transform competent E. coli BL21 (DE3 ). Prol67 residue substitutions of P167G, P167Q, P167S and P167T were introduced to CTX-M-14 by site-directed muta-genesis based on overlap extension PCR with the former recombinant plasmid as PCR template, respectively.The wild-type CTX-M-14, recombinant CTX-M-14 protein and its variants were expressed and purified, then their steady-state kinetic parameters (Kcat, Km and Kcat/Km ) against β-lactam antibiotics were determined.Results The kinetic parameters of wild-type and recombinant CTX-M-14 had no statistically significant differences (P>0.1). The 1/Km, Kcat and Kcat/Km values of P167S variant against ceftazidime were 16-fold, 2.87-fold and 43.6-fold higher than those of recombinant CTX-M-14, respectively, and the Kcat/Km value of P167S variant against penicillin, ampicillin, cefazolin, cefuroxime, ceftriaxone, cefotaxime decreased( < 0.05). Compared with the kinetic parameters of recombinant CTX-M-14, the kinetic parameters of P167T variant against ceftazidime had no significant change, but the Kcat values of P167Q and P167G variants decreased dramatically(P<0.01). Conclusion There was no difference between the enzyme activities of wild-type and recombinant CTX-M-14. P167S variant could not only promote the enzyme affinity of CTX-M-14 to ceftazidime but also improve the conversion rate of enzyme-substrate complex in the ceftazidime hydrolysis. The comparison of the kinetic parameters of CTX-M-14 and its variants with Pro167 residue substitution showed that the increased activity of CTX-M ESBL variants against ceftazidime could not be simply explained with the enlarged cavity in active site that may be caused by the replacement of Pro167 residue by smaller amino acids.

Objective: To observe the effects of manganese( Ⅲ ) meso-tetrakis (N, N'-diethylimidazolium-2-yl) porphyrin (MnTDM) in treatment of early Parkinson's disease(PD) mouse model induced by subcutaneous injection of 1-methyl-4-phenyl1, 2, 3, 6-tetrahydropyridine(MPTP) and to discuss its possible mechanism. Methods:Forty male C57BL/6 mice were evenly randomized into 4 groups: MPTP model group(subcutaneous injection of 25 mg/kg MPTP for 3 days), MnTDM+ MPTP group (15 mg/kg MnTDM was subcutaneously injected 1 h before MPTP injection), MnTDM control group, and normal saline group. Performance of animals in the pole and swimming test was observed 3 days after the last injection. Levels of dopamine (DA) and its metabolites(3,4-dihydroxyphenylacetic acid [DOPAC] and homovanillic acid [HVA]) in the striatum of animals were measured by high-performance liquid chromatography with an electrochemical detector(HPLC-ECD). Thiobarbituric acid (TBA) method was used to examine the levels of malondialdehyde(MDA). Results: Acute injection of MPTP could be used for establishment of PD model. The striatal levels of DA, DOPAC and HVA in MPTP group were significantly lower(P＜0.01)and the striatal level of MDA was significantly higher(P＜0.05) than those of the control group. MPTP had no obvious effect on the behavioral performance of the animals in a short term. MnTDM could partly inhibit the above effects of MPTP. Compared with MPTP group, MnTDM+ MPTP group had significantly higher DA, DOPAC, and HVA levels and significantly lower MDA level(all P＜0.05). There was no significant difference in the behavioral indices of animals between the 4 groups. Conclusion:MnTDM can inhibit lipid peroxidation and promote DA production; it has preventive and therapeutic effects on MPTP induced PD.

Objective To analyze the stability of chromosome variant ratio of three available transformed corneal cell lines. Methods Chromosome specimens of transformed cells including human corneal epithelial cells(HCE),bovine corneal endothelial cells(BCE) and rabbit corneal epithelial cells(RCE) were prepared by a direct method using regular Giemsa staining. Chromosomes of cells in metaphase were counted under the microscope. Then, the variant ratio of chromosomes and their nuclear types were analyzed. Results The chromosome numbers were 56 to 65, 27 to 34 and 74 to 88 for HCE, BCE and RCE, respectively. Chromosome numbers in the three commonly used and transformed corneal cell lines were changed in comparison to their parent tissues. Conclusion Genotyping study may provide important information for using HCE、BCE、RCE in functional studies.

Objective To evaluate accuracy,safety and clinical practicality of three measurements for the length of biliary stent.Methods A total of 120 patients with indwelling biliary stents were randomly divided into group A,B and C by the admission time,who then received endoscopic guide wire measurement (Group A),cutting knife measurement (Group B) and formula measurement (Group C) for biliary stent length.Results There were no statistical significance in sex,age,type of primary disease and biliary stent materials (P＞0.05).Operation time in group C (9.4 ± 2.47 min) was shorter than that in group A (15.8±1.71 min) and B (16.2 ± 2.22 min) with significant difference (P＜0.05).There was no significant difference in the incidence of postoperative cholangitis [7.5％ (3/40) VS 5.0％ (2/40) VS 5.0％ (2/40)]or the measurement accuracy of biliary stent length [100.0％ (40/40) VS 95.0％ (38/40) VS 97.5％(39/40)] (P＞0.05).Conclusion Three stent length measurements are accurate and safe,but formula measurement has more advantage in clinical practicality.