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BACKGROUND: Cardiac valve replacement provides an effective therapeutic means for valvular heart disease. Compared with thoracotomy surgery, interventional treatment, typified by transcatheter aortic valve implantation, has the advantages of minor trauma and rapid recovery. At present, the transcatheter aortic valve replacement is rarely applied in clinical practice. Existing studies mainly focus on the changes of physiological conditions after surgery, while little is reported on the transcatheter aortic valve models. OBJECTIVE: To explore the deformation and stress distribution features of the transcatheter aortic valve, and to verify its working performance. METHODS: The finite element geometric model and mathematical model of the aortic valve, including the aortic valve, blood vessel wall, blood and stent, were established. The fluid structure interaction analysis was carried out by the immersion boundary method, and the effective orifice area index was calculated to verify the performance of the model. RESULTS AND CONCLUSION: During the course of blood shock, the valve leaflets were curl, and the maximum deformation occurred at 1/4 and 3/4 of the valve leaflet free edge. The largest equivalent stress of the aortic valve model was on the stent, but it is almost unformed. The stress concentration of the valve leaflets was located at the curved site of the free edge and the suture points of the leaflets and stents, where a damage easily occurred. The dynamic flow experiments show that the process of the simulation model deformation and effective orifice area index are close to the experimental results. Therefore, the simulation model is reasonable and effective.
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Objective To explore the application value of combined detection of serum hyaluronic acid(HA) ,procollagen type Ⅲ(PCⅢ) ,laminin(LN) and collagen type Ⅳ(CⅣ) .Methods Immunoradiometric analysis was conclucted to detet the index levels of serum HA ,PC Ⅲ ,LN and C Ⅳ in 81 patients with liver disease(24 cases in hepatitis group ,39 cases in liver cirrhosis group ,18 ca-ses in liver cancer group) and 40 healthy adult(control group) .Then compared the differences of 4 indicators among groups .Results Four index levels of serum liver fibrosis from liver disease patients were higher than those of control group(P< 0 .05 or P<0 .01) ,HA level of liver cirrhosis group and liver cancer group were significantly higher than that in hepatitis group (P<0 .05 ,P<0 .01)HA level of liver cancer group was higher than that of liver cirrhosis group(P<0 .05) ,liver cirrhosis was higher than hepati-tis group(P<0 .05) .Conclusion Combined determination of the serum HA ,PCⅢ ,LN and CⅣ has importantly clinical significance in early diagnosis and prognosis of hepatic fibrosis .
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Objective To investigate the expression and significance of endothelin-1 ET-1 in urothelial transitional cell carcinoma. Methods Immunohistochemistry was applied to detect ET-1 expression in 30 cases of urothelial transitional cell carcinoma and 20 cases of normal urothelial transitional cell samples, the results were analyzed in combination with clinical data. Results ET-1 expression in urothelial transitional cell carcinoma was 40.5%, which was significantly higher than that in normal urothelial transitional cell samples(P ＜0.05). ET-1 expression was correlated with grade and stage of urothelial transitional cell carcinoma (P ＜0.05). Conclusion The over expression of ET-1 in urothelial transitional cell carcinoma tissues correlates closely with cancer genesis progression and invasiveness, suggesting that ET-1 might be a biomarker and as a therapeutic target in human urothelial transitional cell carcinoma.
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Objective To evaluate transureteroscopic pneumatic lithotripsy for the treatment of ureteral stones. Methods Transureteroscopic pneumatic lithotripsy was undertaken for 302 cases of ureteral stones,185 male patients and 117 female with and average age of 42.There were 68 upper ureteral stones,106 middle and 128 lower ureteral stones.The transverse diameter of the stones was 5～12 mm and the vertical length 6～24 mm. Results Successful lithotripsy was achieved on one session in 264 cases ( 87.4%),with the stone completely expelled in 4～6 weeks.Complication occurred in 20,14 of which being ureteral perforation.Conservative treatment was adopted in 8 and open surgery in 6,9 of which have been followed up for 3～10 months without ureteral stricture.4 cases complicated by urinary infection. Conclusions Transureteroscopic pneumatic lithotripsy is an effective means of treating ureteral stones.