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find Keyword "model" 782 results
  • COMPARISON OF FEMORAL CONDYLAR TWIST ANGLE IN THREE DIMENSIONAL RECONSTRUCTION DIGITAL MODELS OF KNEE JOINT BASED ON TWO DIMENSIONAL IMAGES OF MRI AND CT

    ObjectiveTo study the difference of femoral condylar twist angle (CTA) measurement in three dimensional (3-D) reconstruction digital models of human knee joint based on the two dimensional (2-D) images of MRI and CT so as to provide a reference for selecting the best method of CTA measurement in preoperative design for the femoral prosthesis rotational position. MethodsThe CTA of 10 human cadaveric knee joint was measured in 3-D digital models based on MRI (group A), in 3-D digital models based on CT (group B), in the cadaveric knee joint with cartilage (group C), and in the cadaveric knee joint without cartilage (group D), respectively. The statistical analysis of the differences was made among the measurements of the CTA. ResultsThe CTA values measured in 3-D digital models were (6.43±0.53)° in group A and (3.31±1.07)° in group B, showing significant difference (t=10.235, P=0.000). The CTA values measured in the cadaveric knee joint were (5.21±1.28)° in group C and (3.33±1.12)° in group D, showing significant difference (t=5.770, P=0.000). There was significant difference in the CTA values between group B and group C (t=5.779, P=0.000), but no significant difference was found between group A and group C (t=3.219, P=0.110). ConclusionThe CTA values measured in the 3-D digital models based on MRI are closer to the actual values measured in the knee joint with cartilage, and benefit for preoperative plan.

    Release date:2016-08-25 10:18 Export PDF Favorites Scan
  • Investigation on the Governance Model and Effect of Medical Schools Merged with Comprehensive Universities in China

    This investigation analyzes the management of medical schools merged with comprehensive universities through internet search and research review in order to reveal management model and effect of the merger. The conclusion is safely reached that governance models are divided into two different patterns: centralized management and decentralized management. Eight universities, representing the two models, were selected and evaluated comprehensively. Among them, the universities that carried out decentralized management have greater development after the merger based on a quality comparison concerning freshmen, faculty, teaching and research between the two patterns. In China, decentralized management in comprehensive universities is more beneficial to the development of medical schools

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  • Establishment and Evaluation of Ischemic Hind Limb Model in Type 2 Diabetic Rats

    Objective To establish and evaluate the hind limb ischemia model in type 2 diabetic rats, and to providea platform for subsequent intervention experiment. Methods Fifteen SD rats were randomly divided into 3 groups:normal control group, diabetes group, and diabetic ischemia group, each group enrolled 5 rats. The 10 rats of later 2 groups were fed with high fat diet for 4 weeks, and then received intraperitoneal injection of streptozotocin (40 mg/kg) to establish type 2 diabetic model. Three days later, the rats of diabetic ischemia group underwent ligation of the bilateral common iliac artery to establish the hind limb ischemia model, but iliac artery of rats in other 2 groups didn’t received ligation. Ultrasound and color Doppler flow imaging detection was used to determine the peak velocity and acceleration time of femoral artery in rats of 3 groups in 2 weeks after operation, and triceps tissues and quadriceps tissues were collected to perform HE staining and SP staining for the observation on status of nutrition and vascular regeneration respectively. Results The peak velocity of femoral artery in rats of normal control group, diabetes group, and diabetic ischemia group were (22.49±3.02) cm/s, (17.36±2.60) cm/s, and (11.23±1.26) cm/s, the acceleration time were (0.080±0.009) s,(0.120±0.009)s, and(0.160±0.020) s, the arteriolar density measured by immunohistochemistry SP method were 6.80±0.84/HPF, 4.60±0.55/HPF, and 1.40±0.55/HPF respectively. The peak velocity of femoral artery and arteriolar density of rats in diabetic ischemia group were both lower (P<0.05), but acceleration time was longer (P<0.05). Results of HE staining showed that structure of triceps tissues was damaged, with infiltration of lots of inflamm-atory cells, which was worse than normal control group and diabetes group. Conclusion Method of high-fat diet in combination with small dose of streptozotocin can induce type 2 diabetic rat model, and hind limb ischemia model can be successfully established by ligation of common iliac artery on this model.

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  • Establishment of Lung Injury Model Caused by Severe Acute Pancreatitis in Rats with Ligated Pancreatic Duct

    Objective To establish a stable and reliable lung injury model caused by severe acute pancreatitis(SAP)in rats, which is helpful to study the acute lung injury (ALI)and acute respiratory distress syndrome (ARDS) induced by SAP.Methods Sixty Sprague-Dawley rats were randomized into ligature group (n=20), traditional group (n=20),and sham operation group (n=20). SAP model was established through retrograde injection of 5% taurocholic acid. After injection, the pancreatic duct of rats was ligated in ligature group, but not in traditional group. The lung damage and edema at 24 h after operaton and natural course of rats were observed.Results The ALI model of rats induced by SAP was established successfully in ligature group. The rats died of acute respiratory failure within 48 h in ligature group, the mortality was significantly higher than that in traditional group (100% vs.20%),P<0.05. Pleural effusion occurred in four rats in ligature group, while no pleural effusion was found in rats in other two groups. The volume of ascites of rats in ligature group was (21.15±5.33) ml, which was more than that in traditional group 〔(7.75±2.66) ml〕,P<0.05, while no ascites was found in rats in sham operation group. The level of serum amylase of rats in ligature group was (2 470.70±399.73) U/L,which was significantly higher than that in traditional group 〔(1 528.40±289.54) U/L〕 and sham operation group 〔(831.10±93.26) U/L〕,P<0.001. The level of serum albumin of rats in ligature group was (6.90±1.66)g/L, which was significantly lower than that in traditional group 〔(13.10±0.99) g/L〕 and sham operation group 〔(16.20±0.92) g/L〕,P<0.001.The lung wet-to-dry weight ratio (W/D) of rats in ligature group was 6.50±0.23, which was greater than that in traditional group (4.92±0.18) and sham operation group (4.61±0.16), P<0.001. The score of lung histopathologic of rats in ligature group was 29.25±1.07, which was significantly higher than that in traditional group (12.65±1.98) and sham operation group (0),P<0.001. The score of pancreas histopathologic of rats in ligature group was 15.95±0.15,which was significantly higher than that in traditional group (13.75±0.66) and sham operation group (0.13±0.29),P<0.001. Under transmission electron microscope, basement membrane of pulmonary capillary of rats in ligation group was destructive, the nuclei was dissolved, endothelial pinocytotic vesicles was functional active, and tight junctions between capillary endothelial cells were blurred and even ruptured. Moreover, tight junctions between alveolar epithelial cells were destructive. Pathological changes of lung ultrastructure of rats in ligation group were more severe than that in traditional group, while no pathological change of lung ultrastructure was observed in rats in sham operation group. Conclusions Injury process and pathogenesis of ALI or ARDS clinically caused by acute gallstone pancreatitis can be reproduced in this animal model, which is suitable to explore the related mechanisms of ALI caused by SAP and provides good animal model for the study of ALI caused by SAP.

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  • Preparation and Evaluation of Chronic Hindlimb Ischemia of Lewis Rat

    Objective To establish chronic hindlimb ischemia model with suture-occluded method in rats, and then compare the effects of chronic hindlimb ischemia model with acute ischemia model. Methods Models of chronic hindlimb ischemia were established by using suture-occluded femoral artery method. The laser Doppler blood flow analysis and angiography were performed on day 7, 14, 28, 42, and 49 after operation, and then the rats were sacrificed after angiography, respectively, the quadriceps and gastrocnemius of contralateral and ipsilateral (surgical side) were gotten, which were tested by HE staining and α-actin immunohistochemistry staining, and then calculate arteriolar density. Results There were no lameness and limb necrosis after operation in chronic hindlimb ischemia models. Laser Doppler analysis found that chronic hindlimb ischemia models were still maintained in ischemia state on day 49 after operation compared with acute ischemic models. The resluts of HE staining showed no acute necrosis and muscle fibrosis in chronic hindlimb ischemia model group. Chronic hindlimb ischemia models after operation did not appear obvious lameness and limb necrosis. The arteriolar density of quadriceps femoris on day 7 after operation in chronic hindlimb ischemia models were less than that in acute hindlimb ischemia models (0.015 2 vs. 0.036 4). Conclusions Compared with the commonly used acute ischemic models, the duration of arterial limb ischemia in chronic hindlimb ischemia rats, which were established by suture-occluded method, is longer and less likely to be affected by the compensatory mechanisms. So suture-occluded method can provide a new animal hindlimb ischemia model for further study of ischemia angiogenesis mechanism and treatment of severe lower extremity ischemia.

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  • Progress of Breast-Conserving Surgery after Neoadjuvant Chemotherapy for Breast Cancer

    Objective To explore the tumor shrinking model, the accurate image evaluation of the residual tumor, and the selection criteria for breast-conserving surgery after neoadjuvant chemotherapy. Methods To review literature on the clinical, imaging, and pathologic study of breast cancer after neoadjuvant chemotherapy. Results The possibility of breast-conserving for patients with large primary tumor is enhanced with neoadjuvant chemotherapy. The tumor shrinking mode after neoadjuvant chemotherapy and its correlation factors are still unclear. MRI is the most accurate image evaluation of the residual tumor at present. M.D.Anderson prognostic index and the American National Cancer Institute selection criteria for breast-conserving surgery after neoadjuvant chemotherapy are helpful for selection of surgical type. Conclusion Tumor shrinking mode and its accurate image evaluation is a key to the selection of breast-conserving surgery and the control of local recurrence after neoadjuvant chemotherapy, and is the research direction in future.

    Release date:2016-09-08 10:49 Export PDF Favorites Scan
  • Dynamically Observed Histopathologic Changes of Acute Rejection in Rat Orthotopic Liver Transplantation Model after Tacrolimus Discontinued 

    Objective To observe the dynamic histopathologic changes of acute rejection in rat orthotopic liver transplantation (OLT) model after tacrolimus discontinued and provide some prediction and evaluation data for clinical acute rejection after liver transplantation. Methods Kamada two-cuff technique was used to establish 60 rat OLT model, and male DA rats, male Lewis rats were used as donors and recipients respectively. Therapeutic amount of tacrolimus (0.05 mg/kg, twice per day, continued for 8 d, 1 d before operation and 7 d after operation, intragastric administrated) was administrated to recipients, then continuously half dose was decreased every day beginning from day 8 after operation and tacrolimus administration was stopped on day 13. Liver tissues were collected on day 7, 14, 21, and 28 after liver transplantation. Histopathologic changes and rejection activity index (RAI) of liver tissues were observed, survival time of recipients was calculated. Results Owing to protection effects of tacrolimus, liver tissues displayed no significant histopathologic changes of acute rejection in 7 d after OLT, while typical acute rejection histopathologic changes began to be observed on day 14 after OLT due to tacrolimus discontinuation. On day 14, 21, and 28, RAI were 3.7±0.9, 6.3±0.9, and 8.1±0.7 respectively. Survival time of recipients was (20.85±0.71) d with a median of 21 d. Conclusion Acute rejection could be induced in rat OLT model after tacrolimus discontinuation, and data collected from this model shows some extent of predictive value and assessment value for clinical liver acute rejection.

    Release date:2016-09-08 10:49 Export PDF Favorites Scan
  • Discussion and Experiences in Establishing Rat Models of Cavernous Transformation of Portal Vein

    Objective To explore adaptive condition of preparation of animal model and afford reliable and stable model animal for further research on clinical diagnosis and treatment of cavernous transformation of portal vein (CTPV) by establishment of animal model by partial portal vein stenosis. Methods According to different straight blunttip needles used, 80 healthy Sprague-Dawley rats were randomly averagely divided into 4 groups: sham operation group, gauge 19 (19G) group, gauge 21 (21G) group and gauge 23 (23G) group. Six weeks after model making, pressure measurement and angiography of portal vein and pathological examination of portal vein and its surrounding tissues were used to evaluate portal hypertension and CTPV. Results Six weeks after model making no rat died in sham operation group, while the numbers of died rats in 19G group, 21G group and 23G group were 2, 4 and 16, respectively. No portal hypertension was displayed in sham operation group and 19G group 6 weeks after model making. Portography showed that the portal vein seemed smooth without variceal and dilatation in sham operation group and 19G group. Pathological examination demonstrated that the portal vein walls were not enlarged, endothelial cells were smooth. The smooth muscles of middle membrane were not thickened and adventitia was intact. Portal pressure increased and CTPV formed in 21G group and 23G group 6 weeks after model making. Portography showed that collateral circulation formed around portal vein in 21G group and 23G group. The vessel lumens with different size and irregular shapes were displayed by pathological examination. Within the narrow fibrous septum between there were the lumens the fat cells, scattered lymphocytes and mast cells, etc. The portal vein walls were enlarged notably, endothelial cells were damaged, the smooth muscle of middle membrane were thickened, thrombosis were formed. Conclusion Establishment of CTPV animal models by partial portal vein stenosis is a reliable method. 21G blund-tip needles fits well in the preparation of CTPV, which is reliable and stable with lower mortality.

    Release date:2016-09-08 10:50 Export PDF Favorites Scan
  • Effect on Microvessel Density and Vascular Endothelial Growth Factor Expression of Radiofrequency Ablation with Arsenious Acid on Liver VX2 Tumors

    Objective To evaluate the effect on microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression of combining radiofrequency ablation (RFA) with arsenious acid (AA) locally treating liver VX2 tumor in rabbits. Methods Twenty-eight New Zealand White rabbits with implanted liver VX2 tumors were randomly divided into four groups, control group (n=7), AA group (n=7), RFA group (n=7) and combination (RFA+AA) group (n=7). All rabbits were killed 14 days after treatment. MVD and VEGF expression were examined by immunohistochemistry. Results The MVD degraded one by one in control group,AA group,RFA group and RAF+AA group, which were (38.50±0.44), (23.07±0.47), (18.65±0.39) and (11.36±0.36)/HP respectively, compared while each two groups, P<0.05. The VEGF expression also degraded one by one, the ratio of positive cases were 7/7, 5/7, 4/7 and 2/7 respectively, compared while each two groups, P<0.05. There was positive correlation between VEGF expression and MVD (Person conefficient of product-moment correlation r=0.47, P<0.01). Conclusion Combining RAF with AA therapy can greatly decrease MVD and VEGF expression of tumor tissue.

    Release date:2016-08-28 04:08 Export PDF Favorites Scan
  • Analysis of Factors Influencing Prognosis of Patients with Bile Duct Carcinoma after Resection

    【Abstract】ObjectiveTo analyze the factors influencing the prognosis of patients with bile duct carcinoma after resection. MethodsThe clinical data of 120 patients with bile duct carcinoma receiving resection in our hospital from 1980 to 2004 were collected retrospectively and clinicopathologic factors that might influence survival were analysed. A multiple factor analysis was performed through Cox proportional hazard model. ResultsThe overall 1year, 3year and 5year survival rates were 71.7%, 32.5% and 19.2% respectively. The single factor analysis showed that the major significant factors influencing survival of these patients were histological type of the lesions, lymph node metastasis, pancreatic infiltration, duodenal infiltration, resected surgical margin, perineural infiltration, peripheral vascular infiltration and depth of tumor infiltration (P<0.05). Lymph node metastasis, pancreatic infiltration and perineural infiltration were found to be the the statistically significant factors influencing survival by multiple factor analysis through the Cox model. ConclusionThe most important prognostic factors for bile duct carcinoma after resection were lymph node metastasis, pancreatic infiltration and perineural infiltration.

    Release date:2016-08-28 04:20 Export PDF Favorites Scan
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