The biological principle of genetic code and genetic computation in natural selection is discussed and a new frame of genetic computation is proposed.

[Objective]To discuss incidence of nerve root stretch injury and threshold value of traction injury in lumbar interbody fusion from posterior rout approach. [Method]Totally patients were treated by lumbar interbody fusion performed with posterior approach using the safe nerve root retractor,the force of dragging nerve root and the retracting time were showed on the display device,while the latency and amplitude of the DSEP wave were measured with Keypoint to monitor the status of the neural function.JOA scores were followed up 10 days,1 month,3 months and 12 months after operation respectively.[Result]Nineteen cases occurred latency prolongation and wave amplitude digression during the operation,when the tensile strength to nerve root was(4.1? 0.45) N and accumulating strength was(42.89?2.96) N*min.The tensile force of aggravation groups exceed stable and improvement groups obviously,incidence of FBSS was higher than the other two groups.[Conclusion]Stretch injury of nerve root during operation is the main cause of earlier period FBSS after interbody fusion.Master single tensile force less than(4.1? 0.45) N or accumulating strength less than(42.89?2.96) N*min is presumed safety.

Objective To investigate the application value of perioperative enhanced recovery after surgery (ERAS) combined with laparoscopic common bile duct exploration (LCBDE) in the treatment of choledocholithiasis.Methods The clinical data of 84 patients with choledocholithiasis who were admitted to the Yijishan Hospital from January 2011 to December 2013 were prospectively analyzed.A single-blind,randomized,controlled study was performed in the 75 patients who were allocated into the control group and the enhanced recovery after surgery group (ERAS group) based on a random number table.All the patients underwent LCBDE,the patients in the control group received conventional perioperative management and the patients in the ERAS group received perioperative management according to enhanced recovery rehabilitation program.All the patients were followed up by outpatient interview till postoperative month 6.The clinical features,liver function and residual stones in the patients were observed.The operation time,postoperative complications,postoperative intestinal function recovery,duration of hospital stay and hospital expenses in the two groups were compared.Measurement data with normal distribution were presented as x ± s.Comparison between groups were evaluated with an independant sample t test.Count data were analyzed using the chi-square test.Results All the 75 eligible patients undergoing successful operation were randomly divided into the control group (35 patients) and the ERAS group (40 patients).The operation time and volume of intraoperative blood loss in the control group and the ERAS group were (185 ±46)minutes and (124 ±28)mL,(178 ±37) minutes and (114 ±32)mL,respectively,with no significant difference (t =0.729,1.431,P ＞ 0.05).There were 12,14 and 10 patients in the control group and 5,6 and 4 patients in the ERAS group with postoperative incision pain,vomit and infection,showing a significant difference (x2=5.054,5.966,4.241,P ＜ 0.05).The level of white blood cell,alanine aminotrausferase and direct bilirubin in the control group and in the ERAS group were (11.4 ± 3.5) × 109/L,(128 ± 33)U/L,(38 ±14) μmol/L and (10.6 ± 3.0) × 109/L,(135 ± 35) U/L,(44 ± 16) μmol/L at postoperative day 1,compared with (7.8 ±2.9) × 109/L,(48 ± 14) U/L,(21 ± 8) μmol/L and (6.9 ±2.1) × 109/L,(43 ± 13) U/L,(20 ±7) μmol/L in the 2 groups at postoperative day 4,respectively,showing no significant difference between the 2 groups (t =1.018,-0.872,-1.767,1.553,1.836,1.044,P ＞ 0.05).The postoperative first flatus day,time of food intake,time of postoperative infusion and duration of hospital stay were (42 ± 13)hour,(45 ±14) hours,(6.8 ±2.3)days and (11.3 ±4.5)days in the control group,and (35± 11)hours,(19 ±7)hours,(4.2 ± 1.8) days and (9.6 ± 2.4) days in the ERAS group,with a significant difference between the 2 groups (t =2.741,10.524,5.485,2.077,P ＜ 0.05).The total hospital expenses was (18 729 ± 3 127) yuan in the control group,which was significantly greater than (16 981 ±2 756) yuan in the ERAS group (t =2.574,P ＜ 0.05).The liver function of all the patients was recovered at the postoperative month 1.Four patients with residual stones in the 2 groups were detected by T-tube cholangiography,and were cured by removal of gallstones by choledochoscopy.There were no complications of the abdominal pain,jaundice and fever in all the patients till the end of follow-up.Conclusion ERAS combined with LCBDE for the treatment of choledocholithiasis is safe and feasible,with the advantages of low morbidity,quick recovery,short duration of hospital stay and less hospital expenses.

ObjectiveTo study the role of laparoscopic splenectomy (LS) using the anterior approach with sequential layered dissection. MethodsFrom December 2007 to July 2009, we performed 27 LS using the anterior approach with sequential layered dissection. The clinical data were retrospectively analyzed. ResultsThe range of splenic length was 8-20 cm. Accessory spleen was found in 6 patients (22.2%). The mean operative time was 125 mins. The mean intraoperative blood loss was 90 ml, and the mean postoperative stay was 5.5 days. ConclusionsLaparoscopic splenectomy using the anterior approach with sequential layered dissection could be carried out smoothly and rapidly. It reduced accidental injuries and shortened the operative time.

Objective To explore the surgical method, clinical result, biomechanical property, and surgical indication of treatment of thoracolumbar burst fractures with titanium mesh fusion device. Methods 22 patients with the thoracolumbar burst fracture and paralysis were treated by anterior decompression and spinal stability reconstruction with titanium mesh fusion device and a titanium plate. In this group, the fracture was at the 12th thoracic vertebra in 7 cases, the 1st lumbar in 14, and the 2nd lumbar in 1. According to Frankel’s classification, 4 cases were of Grade A, 6 of Grade B, and 12 of Grade C. 20 patients experienced the kyphosis deformity. The kyphosis angles varied from 12 to 29 degrees with a mean of 19.5 degrees. Results The period of postoperative follow up varied from 0.6 to 2 years with an average of 1.2 years. The neural function was improved for more than 1 grade. 15 cases could control urination after the surgery. The kyphosis angles were reduced to 3 to 8 degrees with a mean of 5 degrees. The complications caused by the implants were not found. Conclusions To treat the thoracolumbar burst fractures with paralysis, the compressive elements from anterior side of the spinal cord should be completely removed. Since the titanium mesh fusion device plus a plate can reconstruct the spinal stability that satisfies spinal biomechanical property, it presents important application value.

Objective: To evaluate the effect of barrier m em brane on guided bone regeneration(GBR) in alveolar cleft. Methods: The alveolar cleft of animal model was established in the maxilla in 10 rabbi ts. The artificial alveolar clefts were treated immediately with following mater ials respectively: (1) PLA+collagen+rhBMP-2 membrane, (2)PLA membrane, (3)colla ge membrane, (4) blank control. All the membranes were fixed by PLA pin and mini -titanium pin. The animals were sacrificed 2 weeks, 1,2,3 and 6 months after su rgery respectively. Samples were studied through macroscopic observation, X-rad iography, histomorphology and enzyme histochemistry analysis. Results: In the clefts covered with the 3 kinds of membrane more bone fromation wa s observed. The compound membrane of PLA+collagen+rhBMP-2 showed the best bone regeneration effects. Conclusion: The GBR technique can be used to repair the bone defect of alveolar cleft.

BACKGROUND:Previous studies have shown that composite scaffold of chitosan and poly-L-lactic acid has good biocompatibility with some cells. OBJECTIVE:To study the biocompatibility of poly-L-lactic acid reinforced by chitosan and olfactory ensheathing cells. METHODS:In experimental group, olfactory ensheathing cells from Sprague-Dawley rats aged 1-3 days were incubated onto chitosan-reinforced poly-L-lactic acid film. And in control group, olfactory ensheathing cells were co-cultured with poly-L-lysine. The proliferative ability of olfactory ensheathing cells was detected and the cells were observed with immunofluorescence histochemical staining at 1, 3, 5, 7 days after culture. RESULTS AND CONCLUSION:Olfactory ensheathing cells could survive on the chitosan-reinforced poly-L-lactic acid film, and the cytotoxic grade wasⅠ. Morphology of the cells in the experimental group was round or oval, with little processes and the cells aggregated into groups. One day after implantation, the periphery cells of the mass extended short projections and gradual y spread outward;3 days after implantation, the cells spread and most of the cells generated projections, most of which were bipolar or tri-polar;5 days after implantation, cel processes significantly extended, most cells were bipolar and tri-polar cells, while some were oval cells and irregular triangular cells;7 days after implantation, the cel density increased, and cel processes extended. Cel morphology of the control group had similar characteristics as the experimental group. There was no obvious difference between the control and the experimental group in number, perimeter or area of the cells (P>0.05). It showed that chitosan-reinforced poly-L-lactic acid had good biocompatibility with olfactory ensheathing cells.

ObjectiveTo investigate the biomechanical characteristics of different types of fixation with bioactive cervical fusion cage made of hydroxyapatite and poly L-lactic acid in cervical spinal fusion.MethodsIliac crest bone,bioactive cervical fusion cage and bioactive cervical fusion cage with plate fixation were used for anterior interbody implants after anterior discectomy across C5-6 in six fresh human cervical spine specimens respectively,and the range of motion of the cervical vertebrae interbody fusion were measured through the motional stability test.Results After discectomy,Bioactive Cervical Fusion Cage with plate fixation exhibited a significant increase in stability and a decrease of range of motion in angular motion than others in all motional directions ( P ＜ 0.005 ). Bioactive cervical fusion cage exhibited a decrease in stability and an increase of range of motion (6.25 ± 0.29) in angular motion than the intact spine (5.76 ± 0.40) in extension,but the difference was not significantly ( P ＞ 0.05 ).Bioactive cervical fusion cage exhibited a decrease in angular motion than iliac crest bone and a significant increase in stability in all motional directions except extension (P ＜ 0.005).ConclusionsBioactive cervical fusion cage' s biomechanical performance was excellent and bioactive cervical fusion cage with plate fixation was excellent in stability in all motional direction,and could remain initial stability of cervical vertebrae.

BACKGROUND:Transoral ventral release and posterior fusion have predominated in the treatment of irreducible atlantoaxial dislocation, but there is no consistent conclusion on the clinical efficacy.
OBJECTIVE:To explore the clinical outcomes of transoral ventral release and posterior fusion and screw/rod implantation in the treatment of irreducible atlantoaxial dislocation.
METHODS:A total of 32 patients with irreducible atlantoaxial dislocation undergoing thetransoral ventral release and posterior fusion were selected. After treatment, they received cervical anteroposterior and lateral digital DR and cervical MRI examinations to understand the conditions of nerve compression and bone fusion. The recovery of nerve function was evaluated using Japanese Orthopaedic Association before treatment, 6 months after treatment and during final fol ow-up.
RESULTS AND CONCLUSION:Post-treatment, 29 patients were fol owed-up for an average period of 12 months. (1) Al the patients obtained perfect atlantoaxial joint reduction and bone fusion. This achieved reduction and reconstruction of spinal column stability. (2) Spinal compression was obviously lessened after treatment in al patients, and nerve functions were improved to different degrees. Significant differences in Japanese Orthopaedic Association score were detected between 6 months post-treatment, final fol ow-up and pre-treatment (P<0.05). (3) There were no serious intraoperative complications such as spinal cord or vertebral artery injuries. Postoperative complications such as infection or burst were also not found. (4) Imaging evaluation revealed that transoral ventral release and posterior fusion is safe and effective for treatment of irreducible atlantoaxial dislocation.

Objective To investigate the electrocardiographic characteristics and assess the efficiency of ra-diofrequency catheter ablation(RFCA) in ventricular arrhythmia arising from the aortic sinus of Valsalva. Methods Eighteen patients(6 males and 12 females)were selected to undergo RFCA for ventficular arrhythmia originating from the left aortic sinus of Valsava. All of them were symptomatic,but without evidence of structural heart disease. Activation mapping was performed in the endocardium of the aortic sinus of Valsalva,then ablation was performed at the site with the earliest ventricular wave in endocardium electrograms. At the same time, coronary and aortic angiog-raphy were performed to assess the anatomic relationship between the ventricular tachycardia (VT)/ventricular pre-mature contraction (VPC) origin and coronary arteries and aortic valve before the RF energy delivery. Results Eighteen patients were successfully managed, with no major complications related to the procedure. VT eliminated and VPC counts on 24-hour ECG monitoring decreased significantly after the ablation[18 474(12 399,26 812)/24h vs 4 (1,7)/24 h, Wilcoxon signed-rank test, P<0.05]. During a follow-up period of 6 monthes, there was no recur-rence. Conclusions Ventricular arrhythmia arising from the aortic sinus of Valsalva has specific electrocardiograph-ic characteristics, and it can be successfully and safely treated under the guidance of activation mapping.