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 explore the determinant factors influencing the constituent parts of radiological examination in severe trauma patients so as to provide scientific basis for optimized strategy of radiological examination. Methods A prospective study was carried out from April to July 2010 in a tertiary hospital. Clinical data of 60 severe trauma patients admitted to emergency department and ICU were recorded. The type, number and site of trauma under radiological examination were described and compared among different stages of treatment. The correlation between number of radiological examinations and age, number of injured site, injury severity score (ISS), Glasgow Coma Scale (GCS), ICU stay and overall length of hospital stay were analyzed. Results (1) The majority of radiological examinations in 60 patients were radiography and CT, with a corresponding median number of 6.0(3.0～ 11.0, IQR)and 10.0(8.0 ～ 13.8, Qr) times per patient. (2) The numbers of radiography examinations requested in emergency room, emergency ICU and general ward were quite approximately equal (x2 =4.043 ,P =0. 132), while CT examinations were mainly requested in emergency room and emergency ICU (x2 = 20. 274 , P < 0. 001). (3) The numbers of radiological examinations requested for different sites of injury were quite significantly different between radiography and CT during different stages of treatment (x2 = 114.609, 75.932, P < 0.01). (4 ) The number of CT scan requested was positively correlated with number of injured site, ISS, ICU and overall length of hospital stay (r =0.273,0.369,0.523,0.417,all P <0.05). Conclusions The sum of radiological examinations in severe trauma patients was great mainly in radiography and CT, and CT was more predominantly requested. The number of CT scans examinations was positively correlated with severity of injury and length of ICU stay. Further study is warranted to optimize radiological examination in severe trauma patients.

Ideal blood glucose control requires accurate insulin injections under the guidance of frequent glucose monitoring.Artificial pancreas (AP),the closed-loop control system can adjust the input amount of insulin automatically with the body's blood glucose levels.The AP allows diabetics to control blood glucose ideal,then get the benefit of prevention of complications and bring convenience and safety in clinical application.Accuracy is the key issue of the AP.To improve the accuracy of such a system need to improve the detection accuracy and reliability,increase speed and accuracy of the output control,and improve the accuracy of the system regulation model.

Objective To investigate the relationship between apparent diffusion coefficient (ADC)value of rectal adenocarcinoma on DWI and its pathological grading.Methods The ADC values of 46 rectal adenocarcinomas were measured and compared with their histopathological grades.Results The 46 rectal adenocarcinomas included well differentiated adenocarcinomas in 14,moderate-ly differentiated ones in 20,and poorly differentiated ones in 12.The ADC values of well,moderately and poorly differentiated ade-nocarcinomas were (1.125±0.103)×10 -3 mm2/s,(1.030±0.098)×10 -3 mm2/s and (0.922±0.091)×10 -3 mm2/s,respective-ly,exhibiting a statistical difference (χ2 =1 7.35 1,P =0.000).Mann-Whitney U test showed that difference in ADC value between different histopathological grades was statistically significant.Conclusion ADC value of rectal adenocarcinoma can be used as a bio-marker for cell grading to guide treatment decision and prognosis assessment.

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.