Objective Direct impact is a common mechanism of injury for blunt thoracic injury, and if resulting thoracic injury is severe the mortality may be as high as 10% ～ 25% . We aim to develop a mechanical device for animal impact injury experiment, so as to establish a rodent model of severe thoracic injury. Method A spring operated mechanical device for animal impact injury experiment was developed. The device allowed for accurate controlled delivery of impact force to specific areas of the chest well, at specific velocities and degrees of chest compression. Eghty-four male Sprague-Dawley rats were anaesthetized and underwent left carotid artery cannulation. They were randomly divided into seven groups and given the following treatment: group A (Control group) were subjected to sham impact; group B to G animals were subjected to impacts on the right lateral superior chest at different velocities and degrees of chest wall compression. ( B 3 m/s, 20%; C 3 m/s 40%; D 6 m/s 20%; E 6 m/s 40%; F 9 m/s 20%; G 9 m/s 40%). Arterial blood gas samples were taken just before injury, and at 2 and 12 post injury. All rats were sacrificed at 12 hours and their degree of thoracic injury rated. Pathological examination of injured lung tissue was also performed. Results The device was able to deliver impact forces accurately, with ＜ 4% deviation from desired velocity and ＜ 3 mm deviation from target area of impact. Other than the control group, all animals experienced significant hemodynamic changes immediately post impact. Arterial blood gas analysis detected significant hypocapnia in groups B and C. Significant hypoxemia and hypocapnia was detected in groups D, E and F. In groups B,C,D and F, die impact produced a mild thoracic injury with low mortality rate at 12 hours. In group E, the impact produced severe thoracic injury with mortality rate of 33.33% at 12 hours. Group C animals sustained the most serious thoracic injury with mortality rate of 83.33% at 12 hours. Pathological examination revealed injuries from direct trauma as well as secondary lung injuries. Conclusions Our device was able to repetitively deliver accurate and precise impact forces to rats and allows us to establish a rodent model of severe thoracic injury firm blunt trauma. We found that with our device, impact force at velocity of 6 m/s and 40% chest compression produced the most severe lung injury in rats.This helps us establish a rodent model of severe thoracic injury which can be use for future research in severe blunt thoracic trauma and the secondary lung injuries.

Objective:To study the effect of sensory nerve on fracture of mandible and try to find the possible mechanism.Methods:Thirty-two China rabbits were used and divided into two groups for study.They all suffered from a standardized fracture in the left mandible,and half of them with inferior alveolar nerve section(IANS)or without.The callus were stained to observe the expression of substance P(SP)by immunochemistry and analysed by a computerized-graph analysing system.Results:Immunoreactivites of substance P occurred weakly on Day 7 and 14 after operation,and became stronger at late stage in IANS group.On the contrary,stronger immunoreactivites of substance P occurred at the early stage,less on day 21 posttrauma and stronger again on day 28 in control group.The strongest immunoreactivites at each stage occurred mainly in bone marrow on day 28 posttrauma in both groups.There was significant difference in the expressions of substance P in the callus between the two groups(P

[Objective]To observe the clinical results of a hollow compression nail applied to treat the separation of elements of neural arch.[Method]Since February,2003,sixteen cases of separation of elements of neural arch have been treated with a hollow compression nail and bone grafting .The mean age of the group was 32,from 18 to 54.Five cases of separation of elements of neural arch located at L4 and the other 11 at L5.All the patients suffered from severe back pain.During the operation,the presence of the pars interarticularis defect was confirmed.The defects were cleared of any fibrous and cartilaginous tissues.The sclerotic bone margins were curetted until bleeding was noted .Autograft harvested from posterior ilium was done.The hollow compression nail was placed onto the index vertebra.[Result]All the patients were followed-up for more than 14 months (14～26 months).The significant back pain relief was found in all the cases.The bony healing was comfirmed in 11 cases,and the other 5 were in the process of bone growth.[Conclusion]The separation of elements of neural arch can be treated by the hollow compression nail without spinal fusion.The hollow compression nail is proved to be safe and effective.

Objective:To elucidate the effects of calcitonin gene-re la ted peptide(CGRP) on the gene expression of osteoprotegerin(OPG) and receptor ac tivator of nuclear factor-?B ligand(RANKL) in rabbit osteoblasts. Meth ods:Osteoblasts were cultured in media containing 10 -10～10 -7 mol/L of CGRP. After 24-hour incubation,semi-quanitative RT-PCR was perfor med to detect the expression of OPG and RANKL mRNA,and with ?-actin mRNA as th e internal control. Results:CGRP increased the mRNA expressio n of OPG with the maximal effect at the concentration of 10 -8～10 -7 mol/L. CGPR downgulated the mRNA expression of RANKL dose-dependantly.C onclusion:CGRP may regulate the activities of osteoclasts by regulating gene expression of OPG/RANKL.

Objective To study change of insulin resistance and beta-cell function of the patients in hyper-tension with normal glucose tolerance(NGT) to phthogonesis of type 2 diabetes mellitus(T2DM). Methods 84 pa-tients with hypertension were divided into NGT group,and groups of impaired glucose tolerance(IGT) with groups of T2DM. The blood pressure, height, weight, waist circumference, hip circumference, high-density lipoproteins (HDL-C)and total cholesterol(TC) ,fasting plasma glucose(FPG) and fasting plasma insulin(FINS) were measured to deter-mine the body mass index(BMI) ,waist/hip ratio(WHR) ,insulin secretion function[ including Homa β-cell function index(HBCI) and fasting β-cell function index(FBCI)] and insulin resistance level [ including Homa model insulin resistance index(IR) and insulin action index(IAI)] ,statistic comparison were measured between the groups of dif-ferent glucose tolerances. Results The BMI, WHR, diastolic blood pressure ( DBP), TC in IGT group and T2DM group were bigger or higher than those in NGT group ( P<0.05, P<0.01 ), the IAI, HOMA-IS and FBCI in T2DM group were lower than those in NGT group with these in NGT group were lower than those in NGT group( P<0.05 ,P<0.01 ). The HOMA-IR in IGT group and T2DM group were higher than those in NGT group with these in T2DM group were higher than those in NGT group. Conclusion T2DM group and IGT group had more insulin resistance level,sensitivity of insulin and islet β-cell function decrease than those in IGT group,the IGT group and T2DM group are analogous at the body weight is heavier, with waist/hips ratio, triglyceride level and DBP are higher than those in the NGT group in clinic.

Objective To study the effect of sensory nerve on mandibular fracture through detecting the expression of SP in mandibular callus after inferior alveolar nerve (IAN)section. Methods Thirty-two Chinese rabbits were divided into two groups. All rabbits suffered from a standardized fracture in the left mandibula, and half of them underwent IAN section. The callus were stained by hematoxylin and immunochemistry to observe the expression of SP in callus and fracture healing process. Results There were a larger quantity of fibrous callus formation, relatively immatured woven bone callus, lower proportion between immatured bone callus and new bone callus and less immunoreactive substance P in the group with IAN section than in the group with intact IAN at day 7, 14, 21, 28 after operation. Strong immunoreaction of substance P occurred mainly in bone marrow on day 28 postoperatively in both groups. Conclusion Sensory nerve may involve in the process of callus formation at early stage and bone remodeling at late stage so that sensory nerve injury influences the quantity and quality of new callus formation. It seems that neural involvement in bone healing is related to the local concentration of SP in the callus.

Objective To evaluate the short-term results o f reconstruction of PCL(posterior cruciate liga-ment )with quadruple-stranded semitendi nosus tendon and bi-stranded gracilis tendon and to discuss the key point s of the surgery and postoperative rehab ilitation.Methods 12cases of PCL ruptures were reconstructed arthroscopically with quadruple-stranded semitendi nosus tendon and bidruple-stranded gracilis tendon.Results No patients had symptoms of knee instability.The sa g sign and posterior drawer test were negative in all.According to Lysholm knee function scale,10patients were rated as excellent and 2as good 1year after operation,with an average Lysholm score of 85?4.1.Conclusion Arthroscopic reconstruction of posterior cruciate ligament with quadr uple-stranded semitendinosus tendon and bi-stran ded gracilis tendon can result in lim ited invasion,strong graft and satisfactory clinical results.[

Objective To investigate the protective effect of transection of cervical sympathetic trunk (TCST) on the noise-induced hearing loss (NIHL) in guinea pigs. Methods Thirty-six guinea pigs were ran-domly divided into three groups (n = 12): the operation group, the sham group and the blank control group. TCST was performed in the operation group , while the cervical sympathetic trunk in the sham group was only ex-posed and separated. The auditory brainstem response (ABR) thresholds was measured. Levels of superoxide dis-mutase (SOD) and malondialdehyde (MDA) in pasma were detected before operation (T0), before noise expo-sure (T1) and on the time of stopping noise exposure (T2), respectively. The damage situation of the outer cochlear hair cells was also checked. Results (1) At the time of T2, ABR thresholds of operation group and sham group were higher than that of the blank control group (P < 0.01), and ABR thresholds of the sham group are higher than the of the operation group (P < 0.05). (2) Levels of SOD and MDA post-noise exposure (T2) were significantly different among the three groups (P < 0.05). (3) Injured hair cells were more serious in the sham group than that in the operation group. Conclusion TCST has protective effect on NIHL in guinea pigs through increasing SOD and decreasing MDA.

The ergonomics of equipment is important,it is essential to make the ergonomic evaluation in the stage of design. The operation of expanded shelter is a typical form of combination of human labor and machine. The fuzzy comprehensive evaluation model is founded. The high-level factor set include the states of operation, the ratio of every state time to the total time is the corresponding weight for the elements in high-level factor set, the lower-level factor set include the elements which influence the states of operation. For the elements in lower-level factor set, the corresponding weight is given by the experts.

Objective To evaluate the clinical value of fasting blood glucose (FBG) in the diagnosis of multiple organ dysfunction syndrome (MODS) caused by pulmonary infection in elderly patients with diabetes. Methods Patients over 65 years old with diabetic pulmonary infection admitted to Department of Cadres Ward of Bethune International Peace Hospital of PLA from July 2015 to December 2016 were enrolled. According to the patient's highest FBG level during pulmonary infection, all patients were divided in two groups. The cases whose FBG ≥8.83 mmol/L were served as suspicious multiple organ dysfunction syndrome in the elderly (MODSE) group, and those had FBG < 8.83 mmol/L were served as suspicious non-MODSE group. The incidence of MODSE in suspicious MODSE group and suspicious non-MODSE group was compared. The receiver operating characteristic curve (ROC) was drawn, and the clinical value of highest FBG in the diagnosis of MODSE caused by pulmonary infection in elderly patients with diabetes was assessed. Results 119 elderly patients with diabetes and pulmonary infection were enrolled in the analysis. All patients were male, with age of 76-105 years with an average of (89.41±4.16) years. Among 119 patients, 55 of them with suspected MODSE, 64 of them with suspected non-MODSE. The incidence of MODSE in suspicious MODSE group was significantly higher than that in suspicious non-MODSE group (78.2% vs. 12.5%), with statistically significant difference (χ2 = 52.108, P = 0.000). The area under the ROC curve of the highest FBG for diagnosis of MODSE was 0.895, and 95% confidence interval (95%CI) was 0.839-0.951 (P < 0.001). When using FBG ≥ 8.83 mmol/L to diagnose MODSE induced by pulmonary infection in elderly patients with diabetes, the sensitivity was 84.3% and the specificity was 82.4%. Conclusion FBG ≥ 8.83 mmol/L, as an indicator reflecting the changes of metabolic function, have a diagnostic value for MODSE caused by pulmonary infection in elderly patients with diabetes.