The impact of different aortic valve calcification patterns on the outcome of transcatheter aortic valve implantation: A numerical simulation study / 医用生物力学

Objective To investigate the effect of different calcification patterns on the outcome of transcatheter aortic valve implantation (TAVI) by the finite element method.Methods Three calcified human aortic root models (coaptation line calcification model,attachment line calcification model and circular calcification model) were developed according to the location of calcified plaques on the aortic valve leaflets.The processes of self-expanding transcatheter aortic valve implanted into the 3 calcified models were simulated by ABAQUS software.The effects of different calcification patterns on the aortic root stresses,valve frame distortions and paravalvular gaps were analyzed.Results Circular calcification model had the largest maximum principal stress on calcified plaques (18.42 MPa),which might result in a higher risk of stroke after implantation;the circular calcification model also had the greatest distortion of the valve frame,which might lead to worse prosthetic durability;the paravalvular gaps area of the attachment line calcification model was 37.2 mm2,which was more than twice that of the other 2 models,causing more serious paravalvular regurgitation.Cenclusiens Different aortic valve calcification patterns are related to aortic root stresses,valve frame distortions and paravalvular gaps after TAVI,which will have an impact on postoperative complications and prothesis durability.The research findings provide references for the prediction of clinical outcome after TAVI.

The impact of different aortic valve calcification patterns on the outcome of transcatheter aortic valve implantation: A numerical simulation study / 医用生物力学

Objective To investigate the effect of different calcification patterns on the outcome of transcatheter aortic valve implantation (TAVI) by the finite element method. Methods Three calcified human aortic root models (coaptation line calcification model, attachment line calcification model and circular calcification model) were developed according to the location of calcified plaques on the aortic valve leaflets. The processes of self-expanding transcatheter aortic valve implanted into the 3 calcified models were simulated by ABAQUS software. The effects of different calcification patterns on the aortic root stresses, valve frame distortions and paravalvular gaps were analyzed. Results Circular calcification model had the largest maximum principal stress on calcified plaques (18.42 MPa), which might result in a higher risk of stroke after implantation; the circular calcification model also had the greatest distortion of the valve frame, which might lead to worse prosthetic durability; the paravalvular gaps area of the attachment line calcification model was 37.2 mm2, which was more than twice that of the other 2 models, causing more serious paravalvular regurgitation. Conclusions Different aortic valve calcification patterns are related to aortic root stresses, valve frame distortions and paravalvular gaps after TAVI, which will have an impact on postoperative complications and prothesis durability. The research findings provide references for the prediction of clinical outcome after TAVI.

Preventive and therapeutic effect of N-Acetyl-l-cysteine on infection-associated preterm labor in mice

OBJECTIVE@#To study the preventive and therapeutic effect of N-Acetyl-l-cysteine on infection-associated preterm labor in mice.@*METHODS@#A total of 66 C57BL/6 inbred strain pregnant mice were selected and randomly divided into groups A, B and C, with 22 cases in each group. Group A, B and C were regarded as model group, prevention group and treatment group, respectively. The model of infection-associated preterm labor was built by intraperitoneal injection of Escherichia coli. Ten mice of each group were taken and observed the preterm birth rates and live birth rates, respectively. Three mice of each group were killed at 3 h, 6 h, 12 h and 24 h after building the model. Their uterus tissues were collected and the expressions of the AP-1 and MCP-1 in those tissues were assayed with immunohistochemical method and the expressions of NF-κBp65 and TNF-α protein in the placenta tissues of those mice were also detected with immunohistochemical method.@*RESULTS@#The preterm birth rates of mice in groups B and C were significantly lower than that in group A, while their live birth rates were distinctly higher than that in group A (P  0.05).@*CONCLUSIONS@#N-Acetyl-l-cysteine can lower the incidence rate of infection-associated preterm labor by prohibiting the activation of the protein AP-1/MCP-1 and decreasing the expression of NF-κBp65 and TNF-α in the pregnant tissues of premature mice to reduce the inflammatory reactions.

Preventive and therapeutic effect of N-Acetyl-l-cysteine on infection-associated preterm labor in mice

Objective: To study the preventive and therapeutic effect of N-Acetyl-. l-cysteine on infection-associated preterm labor in mice. Methods: A total of 66 C57BL/6 inbred strain pregnant mice were selected and randomly divided into groups A, B and C, with 22 cases in each group. Group A, B and C were regarded as model group, prevention group and treatment group, respectively. The model of infection-associated preterm labor was built by intraperitoneal injection of Escherichia coli. Ten mice of each group were taken and observed the preterm birth rates and live birth rates, respectively. Three mice of each group were killed at 3 h, 6 h, 12 h and 24 h after building the model. Their uterus tissues were collected and the expressions of the AP-1 and MCP-1 in those tissues were assayed with immunohistochemical method and the expressions of NF-κBp65 and TNF-α protein in the placenta tissues of those mice were also detected with immunohistochemical method. Results: The preterm birth rates of mice in groups B and C were significantly lower than that in group A, while their live birth rates were distinctly higher than that in group A (P 0.05). Conclusions: N-Acetyl-. l-cysteine can lower the incidence rate of infection-associated preterm labor by prohibiting the activation of the protein AP-1/MCP-1 and decreasing the expression of NF-κBp65 and TNF-α in the pregnant tissues of premature mice to reduce the inflammatory reactions.

Anti-tumor effect of matrine combined with cisplatin on rat models of cervical cancer

OBJECTIVE@#To observe the anti-tumor effect of matrine combined with cisplatin on U14 rat models of cervical cancer.@*METHODS@#A total of 80 female Kunming rats were used to establish U14 rat models of cervical cancer and then divided into groups I, II, III, IV, with 20 rats in each. For Group I, the control group, injection of normal saline was given around the tumors. For Group II, injection of 2 mg/kg cisplatin was given around the tumors. For Group III, injection of 75 mg/kg matrine was given around the tumors while the combined injection of matrine and cisplatin was given for Group IV with the same doses as Groups II and III. The animals were sacrificed 10 d after the injection and tumors were taken out for the comparisons of tumor weights after injection and calculation of anti-tumor rates, while thymus and spleen were taken for thymus index and spleen index. Blood in eyeball was collected for determination of changes in serum creatinine and urea nitrogen levels. Sections of tumor issue were prepared and morphological changes in tumor tissue cells were observed by using immunohistochemistry technique.@*RESULTS@#After injection, the thymus index and spleen index in Groups III and IV were significantly higher than those in Groups I and II (P < 0.05) while the two indexes in Group II were significantly lower than Group I (P < 0.05). The tumor weights in Groups II and IV were significantly smaller than those in Groups I and III (P < 0.05) with significantly higher anti-tumor rates than Groups I and III (P < 0.05). The serum creatinine and urea nitrogen levels in Groups III and IV were significantly lower than Group II (P < 0.05) and the two indicators in Group III were significantly lower than those in Group IV (P < 0.05). The observation under the histological microscope showed densely arranged tumor cells in Group I, growing as a crumby structure and diffuse appearance, with hyperchromatic and large nuclei, and abundant cytoplasm. In the case of Group II, it showed less tumor cells, with extensive degenerative necrosis, sparse arrangement and karyopyknosis as well as karyoclasis. For Group III, necrosis of tumor cells in different sizes and heterogeneous color in nuclei were observed. For Group IV, the number of tumor cells was significantly smaller than Groups I and III and the tumor cells presented an appearance of crumby structure as cancer nests, with more proliferation of connective tissue.@*CONCLUSIONS@#The treatment of matrine combined with cisplatin can significantly improve the anti-tumor effect on U14 rats with cervical cancer, which can be a new option for the treatment for cervical cancer.

Anti-tumor effect of matrine combined with cisplatin on rat models of cervical cancer

Objective: To observe the anti-tumor effect of matrine combined with cisplatin on U14 rat models of cervical cancer. Methods: A total of 80 female Kunming rats were used to establish U14 rat models of cervical cancer and then divided into groups I, II, III, IV, with 20 rats in each. For Group I, the control group, injection of normal saline was given around the tumors. For Group II, injection of 2 mg/kg cisplatin was given around the tumors. For Group III, injection of 75 mg/kg matrine was given around the tumors while the combined injection of matrine and cisplatin was given for Group IV with the same doses as Groups II and III. The animals were sacrificed 10 d after the injection and tumors were taken out for the comparisons of tumor weights after injection and calculation of anti-tumor rates, while thymus and spleen were taken for thymus index and spleen index. Blood in eyeball was collected for determination of changes in serum creatinine and urea nitrogen levels. Sections of tumor issue were prepared and morphological changes in tumor tissue cells were observed by using immunohistochemistry technique. Results: After injection, the thymus index and spleen index in Groups III and IV were significantly higher than those in Groups I and II (P < 0.05) while the two indexes in Group II were significantly lower than Group I (P < 0.05). The tumor weights in Groups II and IV were significantly smaller than those in Groups I and III (P < 0.05) with significantly higher anti-tumor rates than Groups I and III (P < 0.05). The serum creatinine and urea nitrogen levels in Groups III and IV were significantly lower than Group II (P < 0.05) and the two indicators in Group III were significantly lower than those in Group IV (P < 0.05). The observation under the histological microscope showed densely arranged tumor cells in Group I, growing as a crumby structure and diffuse appearance, with hyperchromatic and large nuclei, and abundant cytoplasm. In the case of Group II, it showed less tumor cells, with extensive degenerative necrosis, sparse arrangement and karyopyknosis as well as karyoclasis. For Group III, necrosis of tumor cells in different sizes and heterogeneous color in nuclei were observed. For Group IV, the number of tumor cells was significantly smaller than Groups I and III and the tumor cells presented an appearance of crumby structure as cancer nests, with more proliferation of connective tissue. Conclusions: The treatment of matrine combined with cisplatin can significantly improve the anti-tumor effect on U14 rats with cervical cancer, which can be a new option for the treatment for cervical cancer.