SUMMARY Peripheral nerve defects are still a major challenge in clinical practice,and the most com-monly used method of treatment for peripheral nerve defects is nerve transplantation,which has certain limitations and shortcomings,so new repair methods and techniques are needed.The peripheral nerve is elongated in limb lengthening surgery without injury,from which we got inspirations and proposed a new method to repair peripheral nerve defects:peripheral nerve elongation.The peripheral nerve could be elongated by a certain percent,but the physiological change and the maximum elongation range were still unknown.This study discussed the endurance,the physiological and pathological change of peripheral nerve elongation in detail,and got a lot of useful data.First,we developed peripheral nerve extender which could match the slow and even extension of peripheral nerve.Then,our animal experiment result confirmed that the peripheral nerve had better endurance for chronic elongation than that of acute elonga-tion and cleared the extensibility of peripheral nerve and the range of repair for peripheral nerve defects. Our result also revealed the histological basis and changed the rule for pathological physiology of peri-pheral nerve elongation:the most important structure foundation of peripheral nerve elongation was Fon-tana band,which was the coiling of nerve fibers under the epineurium,so peripheral nerve could be stretched for 8.5% -10.0% without injury because of the Fontana band.We confirmed that peripheral nerve extending technology could have the same repair effect as traditional nerve transplantation through animal experiments.Finally,we compared the clinical outcomes between nerve elongation and perfor-mance of the conventional method in the repair of short-distance transection injuries in human elbows, and the post-operative follow-up results demonstrated that early neurological function recovery was better in the nerve elongation group than in the conventional group.On the whole,all of these experimental re-sults revealed the physiological phenomenon of peripheral nerve elongation,and described the physiologi-cal change and stretch range in detail.The systematic research results have filled the blank in this field, which is very helpful for clinical limb lengthening surgery,the design of elongation surgery and the evalu-ation of the peripheral nerve stretch injury.Peripheral nerve elongation will become an innovative treat-ment technology in repairing peripheral nerve defects.

SUMMARY Trauma is a global social problem, with the number of deaths up to 5.8 million all over the world annually.Currently, severe trauma has become the first cause of death in young adults in China. Nowadays, there are many problems in the trauma rescue system, including long pre-hospital transfer pe-riod , several secondary transfers, no information exchange between pre-hospital and in-hospital care, and the poor integrated treatment, which results in the situation that the overall treatment level of severe trau -ma in China is relatively low.In order to solve these problems, we carried out the research and promotion of severe trauma rescue standard, involving completing severe trauma information database , providing lo-cal rescue medical workers with standard training , and building up the information system for the linkage and warning of severe trauma.In addition, we developed and promoted the new standard system for se -vere trauma in 15cities with 124 medical centers.Due to our research, the treatment ability of severe trauma in the pilot areas was enhanced, and the mortality and morbidity of severe trauma were reduced significantly.To sum up, we had got the expected results after implementing the project .

Objective: To compare efficacies and complications of total hip arthroplasty ( THA ) with subtrochanteric osteotomy for treating patients with Hartofilakidis types C1 and C2 developmental dyspla-sia of the hip ( DDH) .Methods:Retrospective analysis was performed in 32 patients with DDH who un-derwent THA.These patients were divided into two groups according to Hartofilakidis classification, 17 patients in type C1 and 15 in type C2.Their HSS and WOMAC scores, leg length discrepancy (LLD), hip joint image data and complications were evaluated.Results:HSS scores in type C1 was changed from preoperative 43.7 ±4.6 to postoperative 87.2 ±7.1 (P<0.001), together with WOMAC scores 43.6 ± 4.3 to 87.5 ±6.7 (P<0.001).HSS scores in type C2 was changed from preoperative 44.4 ±5.4 to postoperative 86.5 ±8.0 (P<0.001), together with WOMAC scores 44.1 ±4.1 to 86.7 ±8.1 (P<0.001).Four cases in type C2 and one case in type C1 presented intraoperative fracture which all healed during the postoperative follow-up.The postoperative X-ray films showed that the joint prosthesis location was satisfactory, the surrounding bone was not dissolved and the bone at femur osteotomy site healed with no infection.Conclusion:For unilateral high dislocation DDH patients, THA with femur osteotomy can be effective and safe.No significant differences were found between types C1 and C2, however intraoper-ative fracture in type C2 should be paid attention to.

Objective To analyze the injury characteristics in 2004-2009 road traffic accidents (RTAS) of 0-25 years old adolescents treated in Beijing 120 Emergency Center so as to provide scientific basis for making effective measures in prevention and control of RTAs. Methods The data of all the adolescents with traffic injuries treated in Beijing 120 Medical Emergency Center were collected for a retrospective analysis on sex,age,traffic injury time,wound regions,injury characteristics and death condition of the injured adolescents. Results( 1 ) There were 17 232 injuries and 259 deaths according to the traffic reports from 2004 to 2009. Among the total injury cases,there were 4 229 cases of 0-25 years old adolescents (24.5％),at (20.13 ± 4.43 ) years of age.The injury number showed a significant rising trend with the increase of age and the injury number of 20 years old group were obvious more than that of other age groups.(2) There were 2 252 males and 1 677 females,with ratio of males to females for 1.5:1 ( P ＜ 0.05 ).( 3 ) Total number of patients was decreased yearly.The high incidence of adolescent RTAs could be seen in September,October and May in one year; Friday,Saturday and Sunday in one week; and between 8:00 am and 11:00 pm in one day.The low incidence of adolescent RTAs could be seen in Tuesday in one week,and 3:00-6:00 am in one day (P ＜0.05).(4) Cases of limb and arthrosis wounds (53.4％) were more than those of head and neck wounds (35％).Most of the cases were pedestrians (49.1％ ).(5) There were 38 deaths,including 28 males and 10 females,at ageof (19.29 ± 5.30) years.The death were mainly resulted from craniocerebral injuries (87％),which mainly concentrated in July ( 13.2％ ) and August ( 15.8％ ). Conclusions The present condition ofadolescent traffic injuries is not good enough.We should strengthen traffic security education,increase executive powers in the traffic rush and promote cooperation and communication in pre-hospital emergency,as may be beneficial for decreasing adolescent RTA.

BACKGROUND: It is pointed in some experiment that acidic peptide improves learning and memory of model rat with Alzheimer disease (AD) by inhibiting the synthesis of toxic compounds of nitric oxide (NO).OBJECTIVE: Animal model with Alzheimer disease was established to observe the changes in the levels of NO, nitric oxide synthase (NOS) and acetylcholinesterase (AChE) treated with acidic peptide of various dose concentration.DESIGN: Randomized control and single experiment.SETTING: Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.MATERIALS: The experiment was performed in 2nd Research Room and Experimental Animal Room of Teaching-Research Room of Biochemistry and Molecular Biology of Basic Medical College of Zhengzhou University.Totally 100 SD male rats were selected and some of them were excluded due to retarded response in step down test. Totally 84 rats were included in the experiment and randomized into 7 groups, named normal control,model group, physiological saline group (PS group), Piracetam group, acidic peptide groups of 15, 30 and 60 mg/kg, 12 rats in each group. Acidic peptide was a new small molecular peptide separated from bovine brain and is tripeptide composed of three glutamic acids.METHODS: Except normal control, in the rest groups, after 1 week routine breeding, cerebral stereotactic microinjection was used to inject 5 μg ibotenic acid in hippocampus of rats to destroy bilateral Meynert's nucleus basalis to establish AD model. In normal control and model group, no medication was applied. In PS group, physiological saline was used for gastric perfusion. In piracetam group, piracetam of 0.3 g/kg was used for gastric perfusion and in acidic peptide groupsof 15, 30 and 60 mg/kg,acidic peptide of 15, 30 and 60 mg/kg was applied for gastric perfusion successively, continuously for 20 days, once per day, 2 mL/time. On the expiration of gastric perfusion, the rats were sacrificed after anesthetized and the brain was collected on ice plate to prepare tissue homogenate. After centrifugated at 1 000 r/minute, 4℃ for 10 minutes, the supernatant was collected to assay the levels of NO, NOS and AChE with NO, NOS and AChE kits successively.MAIN OUTCOME MEASURES: Levels of NO, NOS and AChE in brain of rat in each groupRESULTS: Totally 84 rats were employed in the experiment and all entered result analysis. Comparison of levels of NO, NOS and AChE in rat brain of each group: compared with model group, NO levels in acidic peptide groups of 15, 30 and 60 mg/kg were reduced remarkably[(1.95±0.20), (1.39±0.10), (1.25±0.07), (1.00±0.04) mmoL/kg, P ＜ 0.05],NOS levels were reduced remarkably [(4.53±0.18), (3.39±0.09), (3.10±0.06),(2.97±0.06) μmol/kg, P ＜ 0.05] and AChE did not change remarkably[(0.67±0.12), (0.71±0.11), (0.72±0.08), (0.72±0.07) mmol/L, P ＞ 0.05].CONCLUSION: Acidic peptide reduces significantly the synthesis of NO and NOS in brain of AD rat, but it dose not affect AChE activity remarkably. It is suggested that acidic peptide improves learning and memory of rat with Alzheimer disease probably by inhibiting the synthesis of toxic compound of NO or its toxicity.

Objective To investigate the amplifying results of repairing degenerated distal receptor nerves with normal proximal donor nerves.Methods The study was carried out on 12 adult male SD rats that randomly derided into degeneration group and control group.The distal tibial nerve stumps as receptor nerve were denervated for 8 weeks before cross-sutured with partial freshly transected proximal common peroneal nerve stumps in the degeneration group,while in the control group,freshly transected distal tibial nerve stumps were sutured with partial freshly cut proximal common peroneal nerve stumps.The motor nerve conduction (MCV),muscle rigidity contraction force were measured,the histological examinations were carried out and the numbers of myelinated axons were calculated 3 months after the operation.Results The degeneration group showed a poorer regeneration capacity than the control group (P＜0.05).The MCV were (16.992 ± 3.737) m/s,(23.092 ± 2.788) m/s respectively;The ratio of muscle force were (39.642 ±5.865)% and (71.098± 6.778)% respectively.The regenerated myelinated nerve fiber number were 1718.2± 282.0 and 3340.0 ± 506.5 respectively in degeneration group and control group.The amplifying ratio of the degeneration group and control group were 1.581 ± 0.329 and 3.098 ± 0.642.Conclusion The amplifying results of repairing the degenerated nerves are poorer than repairing the freshly injury distal nerves with the freshly transected proximal donor nerves,the results demonstrate a progressive inability of chronically degeneration of the distal nerve to support axonai regeneration.

BACKGROUND: Nerve growth factor (NGF) and brain-derived neurotrophic factor(BDNF) are very important to the survival and proliferation of nerve cells. In the patients with Alzheimer disease (AD), the levels of NGF and BDNF are low.OBJECTIVE: To investigate whether acidic peptide can stimulate rat astrocytes to secrete NGF and BDNF.DESIGN: A randomized control animal experiment.MATERLALS: The experiment was finished in the First Laboratory of Institute of Biopeptide, Zhengzhou University; Cellular Culture Center,School of Basic Medical Sciences of Zhe ngzhou University from September 2003 to May 2005. Fifteen neonatal SD rats within 2 days after birth were selected.METHODS: ① The cerebral cortex of the neonatal SD rats was removed under sterile condition, the astrocytes were isolated and cultured, and then identified with the glial fibriliary acidic protein immunohistochemical staining. ② The cultured astrocytes were randomly divided into six group:blank control group, serum control group, positive control group and acidic peptide treated groups. No treatment was given in the blank control group,serum of 0.2 in volume fraction and 1 000 U/mL interferon were added in the serum control group and positive control.group, 37.5, 75 and 150 mg/L acidic peptides were added in the acidic peptide treated groups respectively. ③ The astrocytes of the 2nd generation, which covered the whole bottom of bottle, were digested to single cell suspension, and then inoculated to three 12-well plates equally at 5×105 /mL. The survival rate and the contents of NGF and BDNF in the supernatant of each group were determined at 24, 48 and 72 hours respectively.MAIN OUTCOME MEASURES: ① Cell numbers and survival rates at different culture time-points; ② Effect of acidic peptide on the proliferation of astrocytes in rats; ③ Changes of NGF and BDNF in the supernatant of astrocytes at different culture time-points.RESULTS: ① As compared with the blank control group, the cell numbers and survival rates at 24, 48 and 72 hours were obviously increased in the acidic peptide groups treated with 75 and 150 mg/L (P＜0.05, 0.01,0.001), but not obviously increased in the acidic peptide group treated with 37.5 mg/L. ② As compared with the blank control group, the rates of proliferation in the acidic peptide groups treated with 37.5, 75 and 150 mg/L were all significantly increased (17.5%, 45.5%, 72.5%, P＜0.001). ③ As compared with the blank control group, the absorbance (A) values of NGF in the supernatant at 24, 48 and 72 hours were all markedly increased in the acidic peptide groups treated with 37.5, 75 and 150 mg/L (P＜0.001),and the A values of BDGF in the supernatant at 48 and 72 hours were significantly increased (P＜0.05, 0.01).CONCLUSION: Acidic peptide can increase the secretions of NGF and BDNF of rat astrocytes to different extent.

Objective To describe the rule of the phenotypic changes of schwann cells after peripheral nerve injury.Methods All experiments were performed on 18 male SD rats.Right midsciatic nerves were cut and were repaired by epineurium suture.At selected time points after injury(1 week,2 weeks,3weeks;n=6 rats for each time point),the proximal and distal sciatic nerve stumps(approximately a 2 mm length of nerve to the injured tip)were removed for detecting the expressions of GFAP,Sox2 and Krox20 by immunofluorescence methods. Results After sciatic nerve transection.there was expansion in the population of GFAP-labeled Schwann cells both in the proximal and distal stumps,and those expression reached the peak near to 7 d.Sox2 was neural stem cell markers and there was no Sox2-expressed cells stumps after nerve injury.And Krox20 positive Schwann cells continuously decreased in the first week,then had increased. Conclusion The differentiated stage of Schwann cells during peripheral nerve repair can be detected by using immunolabeling,and the observation above may be beneficial to find methods in improving nerve regeneration.

Objective:To identify the characteristics and risk factors of the refractures after percuta-neous kyphoplasty ( PKP) and percutaneous vertebroplasty ( PVP) .Methods:A retrospective analysis of 148 patients who had undergone PKP or PVP between March 2006 and October 2013 inPeking University People’ s Hospital was conducted.In the study, 29 patients with 42 refractured vertebra and 119 patients without refracture were included.All the patients were observed for a time of (34.4 ±26.8) months. Clinical, imaging and procedure related factors ( gender, age, height, weight, body mass index, the level of the injured vertebra, the time interval between the procedure and the refracture, the level of the refractured vertebra, the bone cement volume injected, performed PKP or PVP,performed unilateral or bilateral, the percentage of anterior vertebral height restoration, the correction of the Cobb angle, cement diffusion, bone mineral density, presence or absence of diabetes mellitus, history of fractures of the whole body, anti-osteoporosis treatment, cement leakage) for each group were analyzed by Cox propor-tional hazards regression analysis.Results:Of all the patients,16 (55.17%, 16/29) had refractures in the adjacent vertebra, and 13 (44.83%, 13/29) had refractures in the nonadjacent vertebra.Refrac-tures within 3 months accounted for 31.03%(9/29) of all the refractures, and within 1 year accounted for 55.17%(16/29).Both older age (P=0.027, HR=1.051, 95%CI=1.006-1.098) and a his-tory of fractures of the whole body (P=0.012, HR=0.386, 95%CI=0.184-0.812) were statistical-ly significant as the independent risk factors for predicting refractures.Others were not associated with re-fractures ( P>0.05) .Conclusion:Older age and a history of fractures of the whole body are the inde-pendent risk factors of the refractures after PKP and PVP.The mechanism of the refractures after PKP and PVP is mainly the natural development of osteoporosis.

BACKGROUND: It has been confirmed that acidic peptide has good therapeutic effect on rat models of Alzheimer disease, but the mechanism still needs further exploration.OBJECTIVE: To observe whether acidic peptide can inhibit the production of N-methyl-D-aspartate receptor (NMDAR) and beta-amyloid (β-amyloid) in brain, and accelerate the production and excretion of nerve growth factor (NGF) in rats with Alzheimer disease.DESIGN: A randomized controlled animal experiment.SETTING: Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Zhengzhou University.MATERIALS: The experiments were finished in the first laboratory of Institute of Bioactive Peptide, Zhengzhou University and the Cellular Culture Center, School of Basic Medical Sciences of Zhengzhou University from March 2005 to May 2006. Seventy 10-week-old healthy male SD rats without dementia symptoms were randomly divided into 7 groups with 10 rats in each group: normal control group, model group, saline group, glutamic acid 0.3 g/kg group, acidic peptide 15, 30 and 60 mg/kg groups.METHODS: Except the normal control group, the rats in the other 6 groups were induced into models of Alzheimer disease by damaging bilateral nucleus basalis of Meynert with ibotenic acid, and then intragastric administration of glutamic acid (0.3 g/kg) was given in the glutamic acid 0.3 g/kg group, acidic peptide of corresponding dosages in the acidic peptide 15, 30 and 60 mg/kg groups, and isovolume saline in the saline group respectively, 2 mL for each time, once a day for 20 days continuously.MAIN OUTCOME MEASURES: ① The learning ability of the rats was detected with Y-maze test immediately after the end of intragastric administration, and the times of correct responses were recorded. ② After the end of learning and memory test, the head was cut rapidly to remove brain,treated with immunohistochemical staining, and gray value was scanned with Biosens Digital Imaging System to determine the contents of NMDAR,NGF and β-amyloid in the brain of rats.RESULTS: All the 70 rats were involved in the analysis of results. ①Times of correct responses in the Y-maze test were lower in the other 6groups than in the normal control group (P ＜ 0.01), but higher in the acidic peptide 30 and 60 mg/kg groups than in the model group, saline group, glutamic acid 0,3 g/kg group and acidic peptide 15 mg/kg group (P ＜ 0.01). ②The gray values of NGF in basal forebrain in the model group, saline group,glutamic acid 0.3 g/kg group and acidic peptide 15 mg/kg group were lower than that in the normal control group (69.60±2.41, 69.62±1.46, 69.62±1.46,69.73±1.87, 80.77±2.72, P ＜ 0.01); There were no significant differences between the acidic peptide 30 and 60 mg/kg groups (79.39±2.23, 80.20±1.7, P ＞ 0.05), which were higher than the other groups. ③ The gray values of NMDAR and β-amyloid in cerebral cortex in the model group,saline group, glutamic acid 0.3 g/kg group and acidic peptide 15 mg/kg group were lower than those in the normal control group (NMDAR: 81.01±1.38, 81.31±2.06, 81.37±1.39, 79.38±1.23, 69.50±1.04; β-amyloid:74.26±1.39, 74.89±8.66, 74.88±1.46, 74.16±2.48, 67.40±3.06, P ＜ 0.01),and There were no significant differences between the acidic peptide 30and 60 mg/kg groups (P ＞ 0.05), which were lower than the other groups.CONCLUSION: Acidic peptide of 30 and 60 mg/kg can obviously ameliorate the learning and memory abilities in rat models of Alzheimer disease, which may be realized mainly through up-regulating the NGF content in basal forebrain and down-regulating the NMDAR and β-amyloid contents in cerebral cortex.