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Objective To investigate the influence from natural and constrained modal of the hip joint on internal fixation after implantation of hollow screws and locking plates for treating femoral neck fractures. Methods CT image data of a patient with femoral neck fracture were analyzed, boundary of the hip joint was extracted to generate a three-dimensional (3D) model of the hip joint, and the assembly of common internal fixation models and hip joint models was established. Finite element simulation was then conducted, with focus on vibration characteristics. Results Vibration had a certain effect on internal fixation stability of hollow screws and locking plates. The occurrence of torsion would destroy the fixation environment of hollow screws and locking plates, resulting in a small displacement at the fracture end. In a constrained state, the modal frequency range was lower. Deformation of the vibration shape mostly occurred at proximal end of the femoral head, leading to the loosening phenomenon of internal fixation and prosthesis. A method for judging the stability of internal fixation was proposed from the perspective of vibration characteristics, and it was found that the stability of internal fixation with hollow screws was better than that of proximal locking plates. Conclusions For choosing internal fixation, influences from natural frequency of the screw and plate should be considered, so as to avoid natural frequency of the femur, which may cause resonance. The results can be used as a guidance for the selection of internal fixation materials and the design of structure and configuration.
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Biliary stent is an effective method for treating malignant biliary obstruction. However, duodenobiliary reflux is commonly found after conventional biliary stent, which causes complications such as biliary retrograde infection and stent blockage, and seriously reduces the quality of patients’ life. At present, anti-reflux biliary stent is considered as a promising palliative treatment method taking drainage and preventing duodenobiliary reflux into account. In this paper, research status of anti-reflux biliary stent was reviewed, and key problems such as design and evaluation of anti-reflux valve, valve and stent connection design, biomechanical analysis of anti-reflux biliary stent were mainly summarized. The current research progress and trend of anti-reflux biliary stent were summarized and analyzed.
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Objective:To analyze the expression of cell differentiation cyclin 45 (CDC45) in hepatocellular carcinoma (HCC) tissues, to explore the relationship between CDC45 and the prognosis of HCC, and to explore the possibility of CDC45 as a potential biomarker and therapeutic target for HCC.Methods:Bioinformatics methods were used to analyze the mRNA levels of CDC45 in HCC tissues and normal tissues, and to analyze the relationship between its expression and the survival rate of HCC patients. The clinicopathological data of 90 patients with HCC undergoing surgical treatment were retrospectively analyzed. Immunohistochemical method was used to detect the expression level of CDC45 protein in HCC tissue and normal tissues, and to analyze its relationship with clinicopathological characteristics of patients with HCC.Results:CDC45 is highly expressed in colorectal cancer, breast cancer, prostate cancer, lung cancer, liver cancer, etc. The expression of CDC45 in HCC tissues was higher than that in normal tissues adjacent to cancer ( P<0.05). The expression of CDC45 is significantly related to the clinical prognosis of HCC patients ( P<0.001), and the higher the expression of CDC45, the lower the disease-free survival rate and overall survival rate of HCC patients. CDC45 level is significantly correlated with the number of tumor nodules ( P=0.003) and tumor size ( P=0.003) in HCC patients, but the correlation between CDC45 level and age, gender and alpha-fetoprotein (AFP) levels is not statistically significant (all P>0.05). Conclusions:CDC45 plays an important role in the progression of HCC and is expected to become a therapeutic target and potential biomarker for HCC.
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Objective To investigate the relationship between serum visfatin level and coronary artery stenosis.Methods Based on coronary angiography,85 patients were diagnosed as coronary heart disease.According to oral glucose tolerance test,these patients were divided into 3 groups,34 patients with normal glucose tolerance(CHD group),25 with impaired glucose regulation(CIG group),and 26 with type 2 diabetes mellitus(CDM group).30 non-comary heart disease subjects with normal glucose tolerance were selected as the control group(CON group),and they underwent coronary CT angiography scan and were confirmed coronary disease-free.Blood pressure,body mass index(BMI),waist circumference(WC),waist hip ratio(WHR),fasting plasma glucose(FPG),blood lipid analysis,fasting insulin,and HbA1C were determined.Serum visfatin concentration was assayed and the status of coronary artery was assessed.Coronary artery stenosis was screened by coronary interventional angiography and assessed by Gemini scoring system in CHD,CIG,and CDM groups.Results Compared with control group,serum visfatin in CHD,CIG,and CDM groups were significantly higher(all P<0.05).Compared with CHD group,serum visfatin in CIG and CDM groups were significantly higher(all P<0.05).The correlation analysis showed that serum visfatin level was positively correlated with the involved branches of coronary arteries(r=0.807,P<0.01),serum visfatin level was positively related with Gensini coronary artery score(r=0.669,P<0.01).Visfatin was also positively correlated with WC,WHR,triglyceride(TG,r=0.200,P=0.032,r=0.185,P=0.047,r=0.321,P<0.01),while high density lipoprotein cholesterol(HDL-C)was negatively correlated with visfatin(r=-0.354,P<0.01).Multiple regression analysis showed that senlm hvel of TG and WC were the main influencing factors of visfatin.Conclusion (1)The level of serum visfatin may reflect the severity of coronary artery stenosis,detection of visfatin helps to make early diagnosis of CHD.(2)The raised serum level of visfatin in comary heart disease patients with imparied glucose tolerance is consistent with clinical evidence that diabetic patients have more severe coronary diseases.(3)WC and serum TG are main inilucencing factors,suggesting that visfatin is correlated with abdominal obesity.
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Objective To establish a mini pig model suitable for interventional studies in vivo. Methods The endothelia of unilateral renal arteries in 8 purebred Chinese experimental mini pigs(CEMP)was denuded by inflated balloons after the animals were fed with high cholesterol diet for 13 weeks.The CEMP were fed with h high cholesterol diet continuously till the 40th week.The levels of blood lipid panel and creatinine were tested at week 1,14 and 40.Bilateral renal arteries were examined with intravascular uhrasonography at week 14 and 40.The vessel samples were collected at week 40 and stained with haematoxylin-eosin,Masson trichrome technique, oil O and anti-macrophage immunohistological technique. Results Significant differences of blood lipid panel and creatinine were found between week 1 and week 40.Focal ischemic renal injury could be observed pathologically.Renal arteries of CEMP were suitable for interventional procedure such as angiography and intravascular ultrasonography.Cross-sectional information of vessels could be provided clearly by intravascular ultrasonography and the intimamedian thickness of injured renal arteries was much thicker than that of non-injured ones[(0.89±0.03)mm vs (0.30±0.02)mm,P＜0.05]as evidenced by this diagnostic technique.Pathological findings demonstrated the atheroselerotic profiles of the injured renal arteries.Fibrous and fibro-fatty plaques were the main pathologic types in this CEMP model. Conclusions An animal model with renal arterial atherosclerosis mimicking the progression of atheroselerotic renovaseular disease,which is suitable for interventional procedure is established successfully.Intravascular ultasonography may have potential clinical prospect on the evaluation of atherosclerotic renovaseular disease.
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Objective To explore the change of platelet activation before and after stent implantation in acute coronary syndrome. Methods Detection of positive expression of platelet membrane glycoprotein CD62p,CD63 and thrombin-sensitive protein (TSP) were performed using flow cytometry (FCM) in 82 patients which included 45 unstable angina pectoris (UAP) and 37 acute myocardial infarction (AMI). Another 45 angiographically normal patients served as the control. Results Expression of CD62p, CD63 and TSP after stent implantation in ACS group. On the other hand, the expression of the above factors was higher in ACS group compared with the control group. Conclusion Acute thrombogenesis induced by platelet activation is a basic pathophysiologic process in ACS. Endothelial injury and plaque rupture produced by stent implantation may be a cause of platelet activation.