The basic stress pathway above the acetabular dome is important for the maintenance of implant stability in acetabular reconstruction of total hip arthroplasty (THA). The purpose of this study was to describe the basic stress pathway to provide evidence for clinical acetabular reconstruction guidance of THA. A subject-specific finite element (FE) model was developed from CT data to generate 3 normal hip models and a convergence study was conducted to determine the number of pelvic trabecular bone material properties using 5 material assignment plans. In addition, in the range of 0 to 20 mm above the acetabular dome, the models were sectioned and the stress pathway was defined as two parts, i.e., 3D, trabecular bone stress distribution and quantified cortical bone stress level. The results showed that using 100 materials to define the material property of pelvic trabecular bone could assure both the accuracy and efficiency of the FE model. Under the same body weight condition, the 3D trabecular bone stress distributions above the acetabular dome were consistent, and especially the quantified cortical bone stress levels were all above 20 MPa and showed no statistically significant difference (P>0.05). Therefore, defining the basic stress pathway above the acetabular dome under certain body weight condition contributes to design accurate preoperative plan for acetabular reconstruction, thus helping restore the normal hip biomechanics and preserve the stability of the implants.
Acetabulum ; anatomy & histology ; Arthroplasty, Replacement, Hip ; Biomechanical Phenomena ; Finite Element Analysis ; Hip Prosthesis ; Humans ; Imaging, Three-Dimensional ; Stress, Mechanical ; Tomography, X-Ray Computed

Objective:To evaluate the result of operation and gait analysis at the early stage after direct anterior approach (DAA) in total hip arthroplasty (THA).Methods: In this study,20 patients who suffered from necrosis of femoral head or developmental dysplasia of the hip were scheduled to undergo THA.The basic information and visual analogue scale (VAS) score,Harris score before and after surgery were recorded.All of the patients finished the gait analysis before the surgery and 6 weeks and 12 weeks after the surgery,the data were compared with those of normal adult people.Results: Their hospital stay after the operation was 3.3 d,the VAS score after the operation was no more than 4 points,the positions of prosthesis were satisfactory,and there was no dislocation.The gait analysis results contained step speed,stride,the range of motion (ROM) of hip and knee.The step speed before the surgery (preoperation,Pre) was 0.64 m/s,6 weeks after the surgery (6W) was 0.77 m/s,12 weeks after the surgery (12W) was 1.07 m/s,and the control group was 1.19 m/s.The stride at Pre,6W,12W,and control group were 43.15 steps/min,51.42 steps/min,55.52 steps/min,and 57.15 steps/min,respectively.The ROM of hip joint at Pre,6W,12W,and control group were 31.00°,39.62°,40.40°,and 45.67°,respectively.The ROM of knee joint at Pre,6W,12W,and control group were 50.52°,59.28°,67.29°,and 70.42°,respectively.The results of the gait analysis showed that the gait recovery after the direct anterior total hip arthroplasty was very fast and at the 12th week after surgery the gait of the patients was close to the normal adult people.Conclusion: The direct anterior approach is one of the choosable approach of the THA,and this kind of surgery has a better recovery of gait after the operation,and at the end of 12 weeks after the surgery the gait is very close to the normal adult people.But we also need more studies to prove this conclusion.

Objective To compare the accuracy, image quality and radiation dose between prospective ECG?gated sequential and high?pitch acquisition on 128?slice dual?source CT (DSCT) angiography in infants and children with congenital heart disease (CHD). Methods Ninety?two children with CHD from October 2011 to February 2013 were prospectively enrolled and assigned into two groups according to random number table. Forty?six patients underwent DSCT angiography with sequential mode, and the other 46 patients were examined with high?pitch mode. With surgical and/or DSA results as the standard, the diagnostic accuracy and sensitivity of the two groups for the intracardiac structures, extracadiac and coronary artery anomalies were evaluated, and the comparison was analyzed by Fisher exact test. A 5?grade scoring system was used to interpret the image quality of intracardiac structures, great vessels and the proximal and middle segments of coronary arteries. Interobserver agreement on grades of image quality was assessed by Kappa statistics. The image quality scores were compared using the Mann?Whitney U test. The Student t test or the Mann?Whitney U test was used to analyze the differences between the two groups regarding to patients' age, weight , heat rate, CT attenuation, image noise and SNR in the ascending aorta and the pulmonary trunk as well as radiation dose. Results All 92 patients successfully underwent DSCT angiography. The diagnostic accuracies of intracardiac anomalies by high?pitch group and sequential group were 95.65%(88/92) and 99.28%(274/276), showed significant difference between the two groups (P<0.05), but no significant difference in the sensitivity of intracardiac anomalies (P>0.05) .There was no significant difference in the diagnostic accuracy and sensitivity of extracadiac anomalies between the two groups (P>0.05). The diagnostic accuracies of coronary artery anomalies by high?pitch group and sequential group were 93.48%(43/46) and 100.00%(46/46), showed no significant difference between the two groups (P>0.05), but there was significant difference in the sensitivity of coronary artery anomalies (50.00%(3/6) , 100.00% (11/11)) (P<0.05). There was excellent agreement for image quality scoring of the intracardiac structures, great vessels and the proximal and middle coronary arteries between the two observers (Kappa=0.81, 0.85, 0.85, P<0.05). The median image quality scores of extracardiac great vessels were both 5.00 in high?pitch group and sequential group, and there was no significant difference between the two groups (U=981.000, P>0.05). The median image quality scores of intracardiac structures and proximal and middle segments of coronary arteries respectively by high?pitch group were 4.00 and 3.00, and 5.00 and 4.00 respectively by sequential group. The image quality of intracardiac structures (U=594.500, P<0.05) and proximal and middle segments of coronary arteries (U=397.500, P<0.05) was significantly better in the sequential group than that in the high?pitch group. There was no significant difference between the two groups in CT attenuation, noise and SNR of the ascending aorta and pulmonary trunk. The mean effective doses of the high?pitch group and the sequential group were(0.27±0.11)and(0.39±0.17)mSv, and showed significant difference between the two groups (t=4.316, P<0.05). Conclusions Both sequential and high?pitch mode of 128?slice DSCT angiography provide high accuracy for the assessment of CHD in infants and children, while the high?pitch mode, though with some image quality declined, shows further significantly lower radiation dose.

Objective To explore the application of low-dose prospective ECG-triggering dualsource CT (DSCT) angiography in infants and children with Kawasaki disease (KD).MethodsNineteen children diagnosed of Kawasaki disease underwent low-dose prospective ECG- triggering DSCT angiography (DSCTA) with free breathing and transthoracic echocardiogram (TTE).The overall imaging quality was graded on a five-point scale. Interobserver agreement in subjective image quality grading was assessed by Kappa statistics.The location,number and size of the aneurysms and dilations were recorded and compared with those of TTE.Pearson correlation analysis was used to evaluate the agreement on measurements between DSCTA and TTE.The average effective dose of DSCTA in all 19 children was calculated.ResultsDSCTA was performed successfully in all 19 children.A total of 91.5 ％ (226/247) segments permitted visualization with diagnostic image quality. Fifteen patients were diagnosed with coronary artery lesions. A total of 28 aneurysms and 15 arterial aneurysmal dilations were detected by DSCTA,while 19 aneurysms and 13 arterial aneurysmal dilations were found by TTE.TTE failed to detect 9 aneurysms (2 in the distal right coronary artery,2 in the posterior descending artery,1 in the middle of left anterior descending artery,1 in the middle of left circumflex artery,2 in the distal of LCX and 1 in the obtuse marginal branch)and 2 arterial aneurysmal dilations (1 at the diagonal branch and 1 at obtuse marginal branch). The concordance of DSCTA and TTE in measurement of diameter and length of these aneurysms and aneurysmal dilatations are good (0.63 ± 0.20) and (0.58 ± 0.20) cm vs ( 1.49 ± 0.83 ) and ( 1.22 ± 0.66) cm ( r =0.989 and 0.965,P ＜ 0.05 ).There was a good agreement on overall image quality ( Kappa =0.87 ). The mean effective dose was(0.24 ± 0.08) mSv.ConclusionProspective ECG-triggering DSCTA with very low effective radiation dose is safe,reliable and more sensitive than TTE on diagnosing of coronary artery lesions,especially in the distal lesions,in infants and children with KD.

Objective To explore the clinical value of prospective electrocardiography-triggering high-pitch spiral acquisition by dual-source CT (HP mode ) in children with congenital heart diseases (CHD).MethodsThirty-six patients ( mean age:0.67 years,range:1 month to 2 years and 6 months; 25 males;mean weight:7.7 kg)underwent prospective ECG-triggering high-pitch spiral acquisition.The dose length product (DLP) was recorded to calculate effective dose ( ED ).Two experienced radiologists made diagnosis and assessed the overall image quality by a five-point scale independently.The consistency of their judgment was determined by Kappa statistics.Surgeries were performed in 29 patients,and conventional cardiac angiography(CCA) was performed in 7 patients.The accuracy,sensitivity and specificity of HP mode were calculated based on the surgical or CCA findings.ResultsThe DLP was (5.12 ± 1.64) mGy.cm with a range of 2.4 mGy · cm to 9.2 mGy · cm and ED was (0.125 ± 0.027 ) mSv ranging from 0.078 mSv to 0.179 mSv.The average subjective image quality score was 4.2 ± 0.7.All images were diagnosable.Two radiologists made good agreement ( K =0.774,P ＜ 0.05 ).The accuracy,sensitivity and specificity of HP mode were 98.9％,94.2％ and 99.8％,respectively.ConclusionLow radiation dose with the accurate diagnosis of anomalies makes HP mode a new choice for children with CHD.

Resveratrol, as a natural polyphenolic compound, has a wide range of beneficial effects, which includes anti-tumor, cardiovascular protection, anti-oxidant and estrogen-like effects, and so on. Its various physiological properties are closely related to the therapeutic principle for prevention and treatment of high altitude hypoxia injury. Resveratrol may play an important role in relieving or curing high altitude diseases, especially high altitude polycythemia(HAPC). However, the literature about study and application of resveratrol in plateau medicine field is rarely reported up to now. In this review, we summarized the physiological effects of resveratrol, discussed the possible main principle of resveratrol for HAPC therapy, and looked forward to resveratrol's perspective or potential application in high altitude medicine.
Altitude ; Humans ; Hypoxia ; drug therapy ; Polycythemia ; drug therapy ; Stilbenes ; pharmacology

ObjectiveTo investigate the value of prospective ECG-gated dual-source CT (DSCT)in the diagnosis of coarctation of aorta ( CoA ).MethodsSixteen patients clinically suspected of CoA underwent prospective ECG-gated DSCT angiography and color Doppler flow imaging (CDFI). The diagnostic accuracy of DSCT and CDFI were compared according to the results of operation or DSA.The nonparametric chi-square test was used for the statistics.ResultsSixteen patients were diagnosed as CoA by DSCT,4 were complicated with artial septal defect (ASD),9 with ventricular septal defect (VSD),1 with transposition of the great arteries,3 with dysplasia of aortic arch,7 with patent ductus arteriosus (PDA),1 with abnormal origin of the coronary artery, 1 with bronchus artery dilation. Fifteen patients were diagnosed as CoA by CDFI,1 was diagnosed as interruption of aortic arch. Four were complicated with ASD,9 with VSD,2 with bicuspid aortic valve (BAV),1 with transposition of the great arteries,2 with dysplasia of aortic arch,7 with PDA,1 with bronchus artery dilation.Abnormal origin of the coronary artery was not found.The diagnostic accuracy of DSCT and CDFI were 97.2％ ( 140/144)and 97.9％ (141/144)respectively,there was no significant difference (x2 =0.00,P ＞ 0.05 ).The sensitivity of DSCT and CDFI were both 93.2％ ( 41/44 ),the specificity were 99.0％ (99/100) and 100.0％ (100/100).The mean effective radiation dose was 0.42 mSv. Conclusion Prospective ECG-gated DSCT is a good imaging technique for the diagnosis of aortic coarctation in children.

Objective To investigate the effect of acetyl-L-carnitine (ALC) preconditioning on the PC12 cell apoptosis induced by oxygen-glucose deprivation.Methods PC12 cells were seeded in 96-well plates and randomly divided into 5 groups ( n =6 each):control group (group C),cell injury group (group Ⅰ) and preconditioning with different concentrations of ALC groups (groups A1-3 ).In group C,the cells were incubated with DMEM liquid culture medium containing glucose 0.5 g/L for 3 h.In groups Ⅰ and A1-3 the cells were incubated with DMEM liquid culture medium containing sodium hydrosulfite (Na2S2O4) 3 mmol/L and glucose 0.5 g/L for 3 h,and in addition the cells were pre-incubated with ALC 0.2,0.4 and 0.6 mmol/L for 24 h in groups A1-3 respectively.Cell viability was evaluated by MTF assay,while the apoptosis in cells was detected using TUNEL.The activities of ATPase and SOD and MDA content were also detected.Results Oxygen-glucose deprivation significantly increased the number of apoptotic cells and the content of MDA,and decreased the cell viability and activities of SOD and ATPase in group Ⅰ compared with group C ( P ＜ 0.05).Preconditioning with ALC significantly increased the cell viability and the activities of SOD and ATPaes,and decreased the number of apoptotic cells and the content of MDA in groups A1-3 compared with group Ⅰ ( P ＜ 0.05).Conclusion ALC preconditioning can attenuate PC12 cell injury induced by oxygen-glucose deprivation through inhibition of apoptosis in cells.

Objective To assess the integrity and standardization of structured MRI report for rectal cancer of the affiliated hospital of qingdao university,referring to National Comprehensive Cancer Network (NCCN) guidelines for colorectal cancer (Version 2015)and foreign authoritative research results,and put forward some suggestions to improve the quality.Methods A total of 110 structured MRI reports of 107 patients with rectal cancer were included in the study.The inclusion rates of 8 indexes were evaluated,including tumor site,distance from upper to lower border of tumor (DIS),tumor invasive depth (T staging),anal complex staging (A staging),nodal staging (N staging),the circumferential resection margin (CRM),extramural vascular invasion (EMVI) and metastases staging (M staging),which were compared with research results of structured reports in abroad by using Pearson chi-square test.Results There was a significant difference in the description of N staging (x2 =8.424,P＜0.05) between our research and foreign study,in 110 structured MRI reports.There was no significant difference in the description of tumor site (x2 =0.00,P＞0.05),DIS (x2 =0.041,P ＞0.05),T staging (x2 =3.256,P＞0.05) and CRM(x2 =2.957,P＞0.05) between the two groups.A staging,EMVI and M staging were not described.Conclusion Our structured MRI reports for rectal cancer basically meet international research standards.Structured MRI reports have advantages,and deserve to be further studied and promoted.

Objective: To investigate the influence of displacement of femoral and tibial components on the biomechanics of femoral or tibial bone in coronal view. Methods: A series of CT and MRI of the left knee joint of a Han male volunteer was taken and a three-dimensional finite element model of the healthy knee joint was established. The femoral component and the tibial component were designed with varus 6°, varus 3°, 0°, valgus 3°, and valgus 6°, and were combined into 25 three-dimensional finite element model (FEM) of medial unicompartmental knee arthroplasty. A 1 000 N load was applied along the femoral mechanical axis. The von Mises cloud stress distribution was observed. Moreover, the lateral compartment load ratio, the high contact stress of cancellous bone and medial cortical bone below the tibial component, the upper surface of the polyethylene liner, and the femoral cartilage in the lateral compartment was measured. The statistically significant indicators compared with the neutral position (0° varus or valgus of the tibia and the femoral prosthesis, and 5° posterior slope of tibia prosthesis) were identified by scatter plots to find the dense and sparse areas of point items. The optimal position of the femoral component and the tibial component was determined by the number of items with statistical significance in the sparse area. Results: When the femoral component was placed at 0° position, there was no significant difference in the high contact stress of cancellous bone below the tibial component in the five groups. When the femoral component was placed at 0° position, the tibial component was 6° varus or 6° valgus and the stress was increased by 9.21±3.38 MPa and 9.08±4.13 MPa (P<0.05), respectively. With the changes of femoral and tibial components from 6° varus to 6° valgus, the high contact stress of the medial cortical bone below the tibia was gradually decreased (P<0.05). When the femoral component was placed at 0°, the tibial component changes from 6° varus to 6° valgus without significant difference in the high contact stress on the upper surface of each group of polyethylene gasket. Compared with the neutral position group, the high contact stress of the 6° varus or 6° valgus group were increased by 2.88±2.53 MPa and 3.47±2.86 MPa, respective ly (P<0.05). The lateral compartment load ratio and the high contact stress of lateral compartment femoral cartilage was gradually decreased (P<0.05), when the femoral and tibial components changed from 6° varus to 6° valgus. The number (2.8%, 1/36) of indicators in the sparse area (the combination of all combinations of femur or tibia from 3° varus to 3° valgus) was less than that (57.8%, 37/64) in the dense area (set of all combinations except sparse area), and the difference was significant (χ²=29.61, P<0.001). Conclusion It is suggested that the position of the femoral component and the tibial component in fixed medial unicompartmental arthroplasty should not exceed 3° varus or valgus in patients with standard lower limb alignment.