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Objective Analysis of the effect and the mechanism of adenovirus with down regulation of matrix metalloproteinase inhibitor 1 (TIMP-1) achieved targeting by ultrasound microbubbles combined with ultrasound irradiation for liver fibrosis in rats. Methods Recombinant adenovirus-mediated with down regulation of TIMP-1 gene was constructed and a mixture of recombinant adenovirus and ultrasound contrast agent was prepared.The rat liver fibrosis model was established and divided into 5 groups : model group; adenovirus group (recombinant adenovirus); adenovirus microbubble group (mixture of recombinant adenovirus and ultrasound contrast agent); experimental group (ultrasound irradiation + mixture of recombinant adenovirus and ultrasound contrast agent); ultrasound adenovirus group (ultrasound irradiation + recombinant adenovirus). The rats were sacrificed after 24 hours and liver sections were prepared. The expression of EGFP in each group was observed and the transfection rate was analyzed. The liver slices were stained by Masson to judge the stage of liver fibrosis. ANOVA analysis was used to compare the levels of alanine aminotransferase (ALT) , aspartate aminotransferase (AST) , bydroxyproline (Hyp) , hyaluronic acid (HA) , type IV collagen (CIV) and laminin (LN) in each group. The relative expression levels of TIMP-1 and matrix metalloproteinase 13 (MMP-13) in each group were detected by Western blot. Results The transfection rate of the experimental group was higher than that of the adenovirus group (q = 3.418) , the adenovirus microbubble group (q = 3.756) and the ultrasonic adenovirus group (q = 5.502) , and the difference was statistically significant (P < 0.05); Pathological examination showed that the degree of fibrosis in the experimental group and the grade of liver fibrosis were lower than the other groups (P < 0.01). The activities of ALT, AST, HA, LN, CIV and Hyp in the experimental group were lower than those in the other 4 groups.Western blot showed that the level of TIMP-1 protein expression was highest while the level of MMP-13 protein expression was lowest in the experimental group than those in the other groups. Conclusion Adenovirus with down regulation of TIMP-1 achieved targeting by ultrasound microbubbles combined with ultrasound irradiation can inhibit the activity of TIMP-1 and improve the degree of liver fibrosis. Gene therapy is an potential therapeutic method in the application of treating liver fibrosis.
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Objective To evaluate the combination use of thyroid fine needle aspiration biopsy (FNAB)and V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E gene mutation testing in differentiating benign from malignant thyroid nodules.Methods A total of 64 patients with pathologically-proved thyroid nodules were included in this study.The clinical data,including preoperative ultrasound-guided thyroid FNAB and BRAF V600E gene mutation detection,were retrospectively analyzed.Taking postoperative histopathological results as diagnostic gold standard for the thyroid nodule,the diagnostic values of simple FNAB,simple BRAF V600E gene mutation testing,and combination use of FNAB and BRAF V600E gene mutation detection were separately assessed.Results In the 62 patients a total of 64 nodules were detected (2 patients having bilateral nodules) and treated with surgery.Of the 64 nodules,BRAF V600E mutation was detected in 44 nodules,and 43 nodules were proved to be thyroid papillary carcinoma by postoperative pathological examination.Among the 44 nodules showing BRAF V600E mutation,FNAB made malignant diagnosis in 28,benign diagnosis in 6,and uncertain diagnosis in 10.Of the 20 nodules showing no BRAF V600E mutation,FNAB made malignant diagnosis in 5,benign diagnosis in 3,and uncertain diagnosis in 12.The postoperative pathological examination confirmed that 14 lesions were thyroid papillary carcinoma,4lesions were nodular goiter,one lesion was subacute thyroiditis,and one lesion was thyroid adenoma.Among the 57 thyroid papillary carcinomas,BRAF V600E mutation was detected in 43,with the mutation rate being 75.4％.Compared with the gold standard based on pathological diagnosis,the sensitivity,specificity,positive predictive value,negative predictive value,correct diagnosis rate of FNAB for judging benign or malignant thyroid nodules were 78.9％,85.7％,97.8％,33.3％ and 79.7％ respectively,which of BRAF V600E gene mutation detection for judging benign or malignant thyroid nodules were 75.4％,85.7％,97.7％,30.0％ and 76.6％ respectively,and which of FNAB plus BRAF V600E gene mutation detection for judging benign or malignant thyroid nodules were 94.7％,71.4％,96.4％,62.5％ and 92.2％ respectively.By using McNemar paired data x2 test to compare FNAB with combination use of FNAB plus BRAF V600E gene mutation detection in diagnosing thyroid nodules,the results indicated that statistically significant deference in differentiating benign from malignant thyroid nodules existed between the two methods (P＜0.001).Conclusion For the qualitative diagnosis of thyroid nodules which nature cannot be determined by simple FNAB,FNAB combined with BRAF V600E gene mutation detection can improve the diagnostic accuracy for benign and malignant thyroid nodules.
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Objective To explore the efficacy of radiofrequency ablation (RFA) and ethanol ablation(EA) for treating partially cystic thyroid nodules.Methods One hundred and twenty-four patients with a single partially cystic thyroid nodules which caused pressure symptoms or cosmetic problems were treated with RFA (n =42),EA (n =39) or RFA + EA(n =43).The inactivation rate of the nodule,tumor volume reduction rate,symptom scores (0-10) and complications were evaluated before and after treatment.Results The mean inactivation rate of RFA,EA and RFA + EA groups was (87.50 ± 5.77) ％,(57.00 ± 6.12) ％,(90.03 ± 5.39) ％,respectively.The inactivation rate of the nodule was negatively related to the volume of the solid part of the nodule.As to nodules with the volume ranging from 30 to 45 ml,the inactivation rate of RFA group was lower than RFA + EA group.Nodule volume reduction ratio (percentage) at 12-month follow-up was 90.45％ for RFA group,69.88％ for EA group,and 93.28％ for RFA + EA group.Regarding mean volume reduction,there were no difference between RFA + EA and RFA group (P ＞0.05),while there were significant differences between RFA + EA and EA group (P ＜0.05),also RFA and EA group (P ＜0.05).The patients in EA subgroup with cystic part percentage less than 50％ had a unsatisfying outcome (the volume reduction ratio less than 50％),while there were no differences(P ＞0.05) on the volume reduction ratio of nodule based on cystic part percentage between RFA group and RFA + EA group.The rate of the complication was 7.14％,2.56％,2.33％,respectively.Conclusions Ultrasound-guided percutaneous aspiration combined with RF ablation yielded better results than EA ablation.But due to ethanol ablation being less expensive and simpler to perform than RFA,ethanol ablation should be the first line treatment technique for benign thyroid nodules with cystic part percentage more than 50％,while radiofrequency ablation as first-line treatment for benign thyroid nodules with cystic part percentage less than 50％.
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<p><b>OBJECTIVE</b>To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases.</p><p><b>METHODS</b>In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks.</p><p><b>RESULTS</b>In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values.</p><p><b>CONCLUSIONS</b>The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.</p>
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Humans , Biomechanical Phenomena , Brain Injuries , Finite Element Analysis , Intracranial Pressure , ManikinsABSTRACT
<p><b>OBJECTIVE</b>To explore the relationship between the collision parameters of vehicle and the pedestrian thorax injury by establishing the chest simulation models in car-pedestrian collision at different velocities and angles.</p><p><b>METHODS</b>87 cases of vehicle-to-pedestrian accidents, with detailed injury information and determined vehicle impact parameters, were included. The severity of injury was scaled in line with the Abbreviated Injury Scale (AIS). The chest biomechanical response parameters and change characteristics were obtained by using Hyperworks and LS-DYNA computing. Simulation analysis was applied to compare the characteristics of injuries.</p><p><b>RESULTS</b>When impact velocities at 25, 40 and 55 km/h, respectively, 1) the maximum values of thorax velocity criterion (VC) were for 0.29, 0.83 and 2.58 m/s; and at the same collision velocity, the thorax VC from the impact on pedestrian's front was successively greater than on his back and on his side; 2) the maximum values of peak stress on ribs were 154, 177 and 209 MPa; and at the same velocity, peak stress values on ribs from the impact on pedestrian's side were greater than on his front and his back.</p><p><b>CONCLUSION</b>There is a positive correlation between the severity and risk of thorax injury and the collision velocity and angle of car-thorax crashes. At the same velocity, it is of greater damage risk when the soft tissue of thorax under a front impact; and there is also a greater risk of ribs fracture under a side impact of the thorax. This result is of vital significance for diagnosis and protection of thorax collision injuries.</p>