BACKGROUND: Autologous tendon and artificial tendon are both the important grafts that can reconstruct the ruptured anterior cruciate ligament, but each has their defects and excellents. OBJECTIVE: To investigate the biomechanical change and histological rejection of reconstructing the anterior cruciate ligament of the rabbits with autologous tendon and artificial ligament. DESIGN, TIME AND SETTING: A controlled observation was performed from September 2007 to February 2008 in the Orthopedics Laboratory and the Biological Laboratory of Zhengzhou University (Zhengzhou, Henan, China). MATERIALS: Twenty-eight adult New Zealand rabbits of SPF grade were offered by Zhengzhou University Animal Experimental Center, weighing 2.4-3.1 kg with a mean of 2.8 kg, irrespective of genders. MB66 braid was produced by Smith & Nephew Medical (Shanghai) Limited. METHODS: The tendons of extending toe were harvested in both lower extremities, one tendon was wrapped with artificial ligament, while the other was only processed into the terminal wove dovetail. Anterior cruciate ligament was excised from bilateral knee joints in rabbits through the parapatellar incision, then femoral and tibial bones were drilled to implant the autologous tendon and artificial ligament on one side (serving as combined tendon group), whereas only autologous tendon on the other side (serving as pure tendon group). Both sides were sutured through bone bridge. Every 7 rabbits were killed under anesthesia at 2, 4, 6, and 8 weeks postoperatively. MAIN OUTCOME MEASURES: Gross observation and histological determination were carried out in the reconstructed anterior cruciate ligament of rabbits. The maximal breaking force of both grafts were detected. RESULTS: At 2 and 4 weeks postoperatively, the cells of reconstructed grafts disappeared and showed necrosis. Inflammatory cells infiltrated between autologous tendon and artificial ligament, there were cells growing from the edge to the center. At 6 weeks postoperatively, the autologous tendon had a little loose and disfiguration. The synovial membrane and cells hyperplasia were obvious. The synovial membrane filled the combined tendon and the infiltrative inflammatory cells reduced. The proliferative cells remarkably trended to the center. At 8 weeks postoperatively, the grafts were mostly substituted by new cells, and the artificial ligament was completely parceled by the synovial membrane, but there were still some gaps; The combined tendon exhibited no loose or disfiguration, the infiltrative inflammatory cells disappeared. The cells in grafts were close to normal cells in anterior cruciate ligament, but fibrocytes arranged in disorder and fibers showed a verticality. Biomechanics test results demonstrated the maximal breaking force of combined tendon was more than that of pure tendon (P

Objective To investigate the expression of endothelin converting enzyme (ECE) mRNA in patients with acute cerebral infarction (ACI) and its clinical significance.Methods Blood samples from 40 patients with ACI (patient group) within 72 hours after the onset of ACI and 28 gender and age-matched healthy subjects (control group) were collected on admission. Plasma concentrations of endothelin-1 (ET-1) as well as the serum levels of cholesterol, triglyceride, low density lipoprotein,high density lipoprotein, apoA1, apoB, lipoprotein a and fasting plasma glucose in each sample were measured and analyzed. Additionally, semi-quantitative RT-PCR was performed to check the ECE mRNA level in the blood cells. European stroke scale (ESS) was used to evaluate ACI patients' neurological deficit on admission.Results (1) ECE mRNA could be detected in every blood sample from either patient group or control group. However, the ECE mRNA level increased significantly in the patient group compared with that in the control group (0.31?0.092 versus 0.25?0.10, t=2.46, P=0.016). (2) The plasma ET-1 concentration in patient group was also significantly higher than that of control subjects (183.27?56.63pg/ml versus 156.47?34.24 pg/ml, t=2.23, P=0.029). (3) Plasma ET-1 concentration was negatively correlated with ECE mRNA level in the control group (r=-0.452, P=0.021). However, the result in the patient group was not the same as the control group. (4) The ET-1 concentration and ECE mRNA level in the patients had histories of hypertension, diabetes mellitus and stroke were not significantly different from those in the patients without these histories. (5) No significant correlation existed between plasma ET-1 concentration and ECE mRNA level and age of the patient, ESS score, fasting plasma glucose and serum lipid. Conclusions ECE mRNA level is significantly increased in the early stage of ACI, which may be associated with the acute-phase reaction of cerebral infarction and may have deleterious effects on the development of neuronal injury. Our results suggest the protective reflection in the endothelin system of normal human body may be disturbed by the onset of ACI. The relationship between ECE mRNA level and neurological deficit degree, stroke risk factors is worthy for further study.

Objective To investigate effect of hypothermia on coagulation function in major trauma patients and assess value of thromboelastography (TEG) monitoring.Methods Twenty-two patients with major trauma admitted to the emergency intensive care unit between January 2010 and June 2011 were enrolled in the study.The venous blood of the patients was sampled for TEG determination at different temperatures (37,35 and 33 ℃) to analyze variation of the indices including coagulation reaction time (R),clot formation time (K),rate of clot formation (Angle),maximum amplitude (MA)and coagulation index (CI).The patients were divided into normal coagulation group and abnormal coagulation group based on the CI value at 37 ℃ to analyze effects of temperature on TEG indices in both groups and their differences between groups.Results (1) Among 22 patients,TEG indices including R and K trended upward (P ＜ 0.01),but Angle,MA and CI trended downward (P ＜ 0.01) with decline of the temperatures.(2) K and Angle values,indicators of fibrinogen function,were obviously inhibited (P ＜ 0.05) with the temperature decreasing from 37 ℃ to 35 ℃,but other TEG indices had no significant changes.Whereas,all TEG indices were significantly inhibited when the temperature was decreased from 35 ℃ to 33 ℃.(3) There were significant differences in variation of each TEG index inhibited by hypothermia (P ＜ 0.01).All TEG indices showed significant differerces in the pairwise comparison,except for the differences between R and K as well as between Angle and MA (P ＜0.01).(4) R and K were increased,but Angle,MA and CI were decreased in both groups,with decline of the temperatures.Moreover,all TEG indices in the abnormal group were worse than those in the normal group.Conclusions Hypothermia has significant effect on coagulation function of patients with major trauma.TEG,which may be measured at any temperature,is more accurate in reflection of patients' actual coagulation function and is helpful for choice of an appropriate temperature in the mild hypothermia therapy.

Objective To evaluate the relationship between emergency department length of stay (EDLOS) and outcome of multiple trauma patients in ICU.Methods A retrospective cohort study was performed in multiple trauma patients admitted from the emergency department to ICU during 2010.Patients' data were recorded,including demographic information (gender,age,etc.),characteristics of injury (injury causes,diagnosis,ISS,GCS,emergency operation rate,type of operation),and outcome (inhospital mortality,length of ICU stay,total length of hospital stay,expenditure).Patients were assorted into delayed group (EDLOS ＞ 6 h) and non-delayed group (EDLOS ≤ 6 h),then demographic information,characteristics of injury,and outcome were compared between the two groups.Multivariate Logistic and linear regression analyses were performed to identify the correlation between EDLOS and outcome for all patients and for those with and without emergency operation.Results A total of 476 patients aged (47.5 ± 16.0) years were enrolled in the study and male patients accounted for 73.5％.Median ISS was 29 points (interquartile range,22-34 points),median EDLOS was 4.0 hours (interquartile range,2.8-6.4 hours),and inhospital mortality was 9.2％.Delayed (n =135) and non-delayed (n =341) groups were similar in age,gender,ISS,inhospital mortality (13.3％ vs 7.6％),length of ICU stay,and total length of hospital stay (P ＞ 0.05).Multivariate analysis demonstrated prolonged EDLOS increased inhospital mortality (OR=3.19,95％ CI 1.28-7.95,P ＜ 0.05),especially in patients without emergent operation (OR =4.01,95％ CI 1.31-12.27,P ＜ 0.05).However,prolonged EDLOS produced no effect on mortality in patients with emergent operation (OR =1.72,95％ CI 0.79-3.43,P ＞0.05),length of ICU stay,total length of hospital stay,and expenditure.Conclusion Prolonged EDLOS increases mortality of multiple trauma patients admitted to ICU,especially in patients without emergency operation,thus rapid transportation of these patients from emergency room to ICU will improve the outcome.

BACKGROUND:Magnesium al oy as a fracture fixation material has mechanical properties similar to the bone, good biocompatibility and biodegradability, but its rapid degradation rate in body fluids becomes a clinical bottleneck. Therefore, the use of surface treatments to improve its corrosion resistance is important.
OBJECTIVE:To use magnetron sputtering technology and alkali heat treatment technology in the preparation of coating characterized as both corrosion resistance and biological activity.
METHODS:First, we prepared Mg-Zn-Mn al oy using the smelting technology, and prepared a dense coating on the al oy surface by the magnetron sputtering technique. Then, we processed the coating surface using an alkaline solution, and studied the corrosion behavior of the coating by use of simulated body fluid experiments. We speculated the biological activity of the coating by measuring the content of calcium and phosphorus from the surface products.
RESULTS AND CONCLUSION:We prepared the coating, which had both corrosion resistance and biological activity, on the surface of magnesium al oy by use of magnetron sputtering and alkali heat treatment technology. After soaking in the simulated body fluid for 24 hours and 168 hours, the deposition of the coating surface contained Ca, P products. Ca/P ratios were 1.54 and 2.11, respectively, closed to the bone-phosphate Ca/P ratio. The coating surface formed 5-10μm pitting after 24 hours of immersion, and the pitting grew up with the immersion time. The pitting was enlarged to 100-800μm after 168 hours.

Objective To observe the cardiosomatic motor reflex (CMR)of rats, and to clarify the descending modulation of nucleus raphes magnus (NRM)in cardiac nociception and its pathway.Methods 34 male healthy SD rats were randomly divided into NRM electrical stimulation group (n=8 ), NRM stimulation combined with dorsolateral funiculus (DLF ) transection group (n= 8 ), NRM stimulation combined with antagonist of 5-hydroxytryptamine (5-HT)methysergide intrathecal administration group (n=18).The rat model of CMR was established through inj ecting capsaicin into the pericardial sac of the rats in various groups. The electromyogram (EMG) response of dorsal spinotrapezius muscle was used as detection index, and by placing the stimulation electrode in NRM and (or)intrathecal catheterization, the descending inhibitory modulation of NRM in CMR and the influence of DLF tansection or methysergide intrathecal administration in descending inhibitory modulation of NRM were observed.Results Compared with before stimulation,the EMG response was decreased after NRM electrical stimulation (75 μA) (P<0.05 );after bilateral DLF transection, the EMG response after NRM stimulation was significantly increased compared with before DLF transection (P<0.05 ), and there was no significant difference compared with its control (P> 0.05 ). In addition, after intrathecal administration of methysergide,the EMG response after NRM stimulation was significantly increased compared with before intrathecal treatment of methysergide (P<0.05),but it was still significantly smaller than that of its control (P<0.05). Conclusion Cardiac nociception evoked by capsaicin stimulation is subject to descending inhibitory modulation from NRM,and the descending inhibition from NRM is conveyed via the DLF and partially mediated by endogenous 5-HT system.

Objective:To explore the efifcacy and safety for radiofrequency catheter ablation (RFCA) of left bundle branch guided by left bundle potential (LBP), X-ray image with EnSiteNavX System in canine model.
Methods:The RFCA of left bundle branch was conducted in 13 dogs. A mapping catheter was positioned in right atrium to record right-sided His-bundle (R-His) potential, and an ablation catheter via right femoral artery was retrograded to left ventriclefor LBP mapping and ablation. Meanwhile, EnSiteNavX System was used to identify R-His, L-His and LBP at the same time. The potential characteristics in dogs with successful ablation were observed, the PR interval, QRS shape and time limit, AH interval, HV interval, the A/V electro-gram ratio in ablationcatheter at before and after ablation were recorded. The procedural time and X-ray exposure time between LBP with X-ray image method and LBP, X-ray image with EnSiteNavX System method were compared.
Results: There were 9/13 dogs received successful left bundle branch ablation, 3 dogs failed and 1 suffered from complete A-V block. At the successful ablation target site, the LBP-V was (17.8 ± 2.6) ms with the range of (13-21) ms, and the A/V electro-gram ratio<1/10. The procedural time and X-ray expose time were signiifcantly decreased in LBP, X-ray image with EnSiteNavX System method than those in LBP with X-ray image method P=0.007 and P<0.001.
Conclusion:Under the LBP, X-ray image with EnSiteNavX System guidance method, left bundle branch could be safely and effectively ablated to establish left bundle branch block (LBBB) model in experimental canine.

Objective To investigate the clinical value of noninvasive monitoring technique in intracranial hemorrhage and secondary brain edema after operation for traumatic brain injury (TBI).Methods A retrospective case-series analysis was done on 196 TBI patients (128 males and 68 females,aged 18-60 years old,median age 36.5 years old) admitted from January 2014 to December 2015 and treated surgically with simultaneous implantation of intracranial pressure (ICP) probe.There were 89 patients with Glasgow coma score (GCS) 6-8 points and 107 with GCS 9-12 points.The values of ICP were recorded.The changes of cerebral electrical impedance (CEI) were monitored in all patients through the BORN-BE noninvasive monitor.Results The disturbance factor of the BORN-BE noninvasive monitor in brain edema in the cerebral stage exhibited a strongly positive correlation with ICP (R =0.954,R2 =0.910,P ＜ 0.05).All the rebleeding occurred within 24 hours after operation in the study.The disturbance factor showed a significant reduction in the bleeding side,which exhibited a strongly negative correlation with the volume of cerebral hemorrhage (R =-0.982,R2 =0.964,P ＜ 0.05).Conclusion After operation for TBI,the ICE changes from dynamic noninvasive monitor can reflect the severity of brain edema digitally,indicating that the postoperative rebleeding and its volume may play an important role in selection of optimal treatment.

Objective To investigate the effect of astilbin on expressions of perforin and granzyme B in activated T cells of mouse heart transplantation model with acute rejection.Methods Cardiomyocytes of BALB/C mouse and spleen cells of C57BL/6 mouse were harvested and made into single cell suspensions.The cardiomyocytes(2?10~5 ml~(-1))as stimulators and spleen cells(1?10~6 ml~(-1)) as responsers were mixed and cultured.The model of mouse heart transplantation with acute rejection in vitro was therefore established.There were two groups in the experiment.Control group is the mixed culture of the cardiomyocytes and spleen cells;Astilbin group is the mixed culture of the cardiomyocytes and spleen cells with astilbin(15?g/ml).Apoptosis of T cells were analyzed by TUNEL assay.The expressions of perforin and granzyme B were measured by RT-PCR.Results Apoptosis of activated T cells in Astilbin group was significantly increased than that of the control group(P