Objective To evaluation the diagnostic value of echocardiography in mechanical prosthesis valve dysfunction(MPVD).Methods Fifty-two patients who underwent reoperation due to MPVD were included,and the preoperative,introperative and postoperative results of echocardiography was compared with the results of surgery or pathologic diagnosis.Results The etiology of MPVD based on cardiac surgery was thrombus in 12,fibrous tissue hyperplasia in 23,thrombus and fibrous tissue hyperplasia in 16,lost of mechanical disc in 1.The types of MPVD diagnosed by echocardiography were stenosis in 29,regurgitation in 2,stenosis and regrigitation in 12,intermittent obstruction in 8,and total obstruction in 1.Successful assessment of prosthetic disc by transthoracic echocardiography was 78.4％ and can be improved to 96.1 ％ when combined with transesophageal echocardiography.Complementary message by transesophageal echocardiography were provided in 10 patients and corrective message in 1 patient.No recurrent MPVD was find during the follow-up.Conclusions Echocardiography can be used as the frist choice for the evaluation of the MPVD and can make precise assessment of the abnormal hemodynamic change and state of motion of the valve.

Objective The present study aimed to observe the changes in Aβ deposition and estrogen receptor levels in the hippocampal tissue of female APP/PS1 mice with Alzheimer's disease(AD)after receiving an ovariectomy at different ages.Methods 3-month-old APP/PS1 female mice were divided into three groups,with 20 mice in each group.Ten mice were treated with bilateral ovarian resection via abdominal surgery as the model(ovx)group.The 10 mice in the control(sham)group underwent surgery in which an equivalent volume fat was removed from the corresponding area.After 3,4,and 5 months,APP/PS1 mice were assigned to 6-,7-,and 8-month age groups.The cognitive function of the APP/PS1 mice of different ages was evaluated using the Morris water maze.Morphological changes to intracellular organelles in the CA1 area of the hippocampus of the two groups of mice were observed using transmission electron microscopy.Immunofluorescence staining was used to detect the deposition of Aβ in the CA1 area of the hippocampus of the two groups of mice.ELISA was used to detect the levels and contents of serum estrogen,ROS,SOD,and MDA,and Western blot was used to determine the expression levels of ERα and ERβ.Results As the ovx group mice increased in age,their escape latency in the water maze test gradually lengthened,the deposition of Aβ in the hippocampal CA1 area increased,the mitochondrial swelling of hippocampal neurons increased,and larger amounts of lipofuscin and amyloid deposition were observed in the cytoplasm.Their serum E2 levels and SOD activity decreased,while their ROS levels and MDA contents increased,and the expression of ERα and ERβ in the hippocampal tissue decreased.Conclusions Ovariectomy in mice with low estrogen status may exacerbate hippocampal Aβ deposition and age-dependent cognitive decline.