Objective To assess left ventricular systolic strain in patients with mitral valve replacement (MVR) by speckle tracking echocardiography. Methods Two-dimensional images were acquired from the apical four-chamber view, two-chamber view and long-axis of the left ventricular view in 30 MVR patients (MVR group) and 30 healthy subjects matched by age and gender(control group), and then were analysed off line to evaluate left ventricular systolic strain. The maximum systolic longitudinal strain(LS) of myocardial segments and global longitudinal strain(GLS) were measured in apical views. Left ventricular ejection fraction(LVEF) was calculated using Simpson's method. The correlation between GLS and LVEF was analyzed using Pearson's method. Results Compared with the control group, LS of corresponding segment and GLS in MVR group decreased significantly (P < 0.01), but there were no statistical differences within MVR group(P>0.05). There was a good linear positive correlation between GLS and LVEF in patients (r = 0.710, P <0.01). Conclusions Speckle tracking eehoeardiography is available for measuring left ventricular systolic strain and estimating global systolic function in patients with MVR. Bull's-eye strain map, created by speckle tracking imaging, can achieve an accurate real-time segmental wall motion analysis.

Objective To evaluate the clinical value of color M-mode Doppler echocardiography (CMM) in assessing left ventricular(LV) diastolic function after mitral valve replacement(MVR). Methods Fifty-two patients who had received the implantation for more than three months were examined by echoeardiography (MVR group). Thirty age and sex-adjusted normal volunteers served as control group. Dimensions of left atrium and ventricle,ejection fraction(EF) and mitral inflow velocity(E) were measured by two-dimensional and Doppler eehocardiography. Color M-mode Doppler flow propagation velocity(Vp) and TDl-derived diastolic mitral annular velocity(Em) were measured from the apical four-chamber and two-chamber views. Then two new indexes based on the ratio of E to Vp(E/Vp) and E to Era' (E/Em') were while E/Vp and E/Era' increased, there were significant differences(P <0.01). The correlation coefficient and atrial fibrillation(P <20.01) ,however E/Vp was lower affected hy EF or atrial fibrillation(P >0.05). dysfunction were 2.00. Conclusions CMM is an effective technique to assess LV diastolic function after MVR. E/Vp has good consistency with E/Era and may be a potential useful parameter for assessing LV diastolic function.

Objective To evaluate the clinical value of tissue Doppler imaging(TDI)in assessing left ventricular(LV)function after mitral valve replacement(MVR).Methods Forty-five patients having their implantations for more than three months were examined by echocardiography and divided into atrial fibrillation group(AF group,n=21)and sinus rhythm group(SR group,n=24).Thirty normal volunteers served as control group.Left atrium and ventricle indexs of cardiac function and mitral inflow velocity(E)were measured by two dimensional and Doppler echocardiography,and TDI-derived systolic mitral annular velocity(Sm),diastolic mitral annular velocity(Em)and isovolumic relaxation time(IVRT)were measured at the septal and lateral corners of mitral annulus from the apical four-chamber view.Then E/Em ratio was calculated.Results ①Compared with control group,Sm and Em in MVR group were significantly lower and IVRT was higher(P＜0.001),however there were no significant differences between AF group and SR group.② The E/Em ratio in MVR group was significantly higher than that in control group(P＜0.001)and positively correlated with IVRT.The best cutoff value for E/Em ratio was increased of 15 which yielded the sensitivity and specificity in predicting LV diastolic dysfunction were 91.11% and 90.32%,respectively.The area under the ROC curve was 0.9548±0.0402.Conclusions TDI-defived indexes(Sm,Em)can assess LV function accurately and the E/Em ratio,an estimate of myocardial relaxation and LV filling pressures,can be used to evaluate left ventricular diastolic function after MVR.

Farnesoid X receptor (FXR) belongs to the nuclear receptor superfamily. It is highly related to the formation of metabolic syndrome and the glucose homeostasis, and therefore represents an important drug target against metabolic diseases and diabetes. In recent years, great progress has been made in the agonists, antagonists, and crystal structures of FXR. The diverse FXR ligands and their structure-activity relationship are reviewed in this article. The advances in the crystal structures of FXR in complex with different ligands are also introduced.

Objective To detect the change of brain activity under different depth of anesthesia (DOA)noninvasively. Methods The Lempel-Ziv complexity C(n) was used to analyze EEG and its four components (delta,theta, alpha, beta), which was recorded from SD rats under different DOA. The relationship between C(n) and DOA was studied. Results The C(n) of EEG will decrease while the depth of anesthesia increasing and vice versa. It can be used to detect the change of DOA sensitively. Compared with power spectrum, the change of C(n) is opposite to that of power spectru,. Only the C(n) of delta rhythm has obvious variations induced by the change of DOA, and the variations of delta is as similar as the EEG's. Conclusion The study shows that the desynchronized EEG is replaced by the synchronized EEG when rat goes into anesthesia state from awake, that is just the reason why complexity and power spectrum appear corresponding changes under different DOA. C(n) of delta rhythm dynamic change leads to the change of EEG, and the delta rhythm is the dominant rhythm during anesthesia for rats.

Objective To explore the correlation between postoperative cognitive dysfunction (POCD)and serum level of S100βand NSE in patients undergoing on-pump heart valve replacement. Methods Ninety-eight patients underwent elective heart valve replacement were enrolled and divided into two groups:POCD group (group P)and none POCD group(group NP)by the result of neurocog-nitive testing with MMSE performed preoperatively and on the first postoperative day.Serum S-100βprotein and NSE were measured before operation(T0 ),at the end of operation(T1 ),24 h(T2 )and 48 h(T3 ) postoperatively.Results The incidence of POCD on the first postoperative day was 45 (45.9%).Compared with T0 ,the S100βincreased at T1 in both groups (P <0.05),NSE increased at T1 and T2 in both groups,and NSE increased in group NP at T3 (P <0.05).There was no signifi-cant difference of NSE between groups P and NP.The prolonged recovery time(OR = 1.222,P =0.004)and increased concentration of S100βat the end of operation(OR=1.85,P =0.009)were pre-dictors of POCD on the first postoperative day.Conclusion There was a higher incidence of POCD af-ter on-pump heart valve replacement surgery.The prolonged recovery time and increased concentra-tion of S100βat the end of operation might be predictors of POCD.

Objective To propose a novel computer-aided segment algorithm, and retrospectively investigate its effect on radiologist's sensitivity and specificity for discriminating malignant masses from benign masses basing on ultrasound images. Methods Four hundred and sixty-six images of 100 masses obtained by conventional ultrasound were processed by a novel segment algorithm. Radiologists who were blind to the histology results were invited to analyse the original and computerized images respectively. The sensitivity and specificity were calculated by means of a binary outcome using receiver operating characteristic(ROC) analysis. Results By using the segment algorithm, the quantity of the image was obviously improved, especially the margin and calcification of the masses. The diagnostic performance of the radiologists was also improved. The sensitivity rose from 70.32% to 90.52% while the specificity was 74.31%. The area under the ROC curve increased significantly (P<0.01) from 80.8% to 90.5%. Conclusions The proposed segmentation algorithm can improve the diagnosis performance of the radiologists by meliorating the quality of the ultrasound image.

Objective To evaluate the clinical value of quantitative tissue velocity imaging (QTVI) in assessing left ventricular(LV) global and regional myocardial function in patients with mitral valve replacement(MVR).Methods Eighty patients having their implantations for more than six months were examined by echocardiography.QTVI-derived parameters such as peak systolic velocity(Sa,Sm) and early diastolic velocity(Ea,Em) of mitral annulus and LV wall were measured from the apical four-chamber,two-chamber and long axis corresponding myocardial segments in MVR groups decreased and LV ejection fraction but negative correlation between Ea' and isovolumic relaxation time(IVRT') in patients(P<0.01).Conclusions QTVI plays an important role in determining LV function of patients after MVR accurately.

Objective To explore the clinical value of wave intensity(WI) curve of the carotid artery in patients with thyroid diseases and its value in evaluating cardiovascular function. Methods All 85 patients with thyroid diseases,including 45 hyperthyroidism and 40 hypothyroidism, were enrolled as case groups,while 270 healthy volunteers were considered as control. All the case groups and control were taken WI test under quiescent condition,and six continuous curves of the carotid artery diameter changes were recorded.Then the parameters of accelerating wave intensity (W1), decelerating wave intensity ( W2), negative area (NA) ,corrected R-W1 and W1-W2,elasticity modulus(Eρ) ,stiffness index(β) ,arterial compliance(AC) and pluse wave velocity(PWV) were calculated. Relationship between those indices and FT3 ,FT4 and TSH were analyzed by Pearson correlative analysis. Results The WI curve appeared differently among different groups,but the vessel elasticity indices did not have statistical significance. Correlation only existed between FT3 and part of the WI parameters. FT3 positively correlated with W1 ( r = 0. 951, P ＜0.01 ), NA( r =0.813, P ＜0.01) and W1-W2' ( r = 0. 887, P ＜0.01 ). And R-W1 ' negatively correlated with FT3( r =-0.878, P ＜0.01 ). Conclusions The WI curve could represent different function status of thyroid,and could be considered as a noninvasive examination for further clinical research,which may help explain the corresponding cardiovascular changes.

Objective To explore the value of coronary flow reserve(CFR) evaluating myocardial ischemia measured by adenosine triphosphate (ATP) stress transthoracic Doppler echocardiography (TTDE),and the feasibility of CFR to predict coronary stenosis.Methods Fifty-four patients suffering chest pain with known or suspected coronary artery disease were performed ATP stress TTDE to measure resting and maximum expansion coronary blood flow velocity and calculate CFR.all patients were performed by coronary angiography (CAG) and single-photon emission computed tomography (SPECT) myocardial perfusion imaging.Results ① To evaluate myocardial ischemia,there was not statistical significant difference between non-invasive CFR and SPECT myocardial perfusion imaging(P ＞0.05).CFR≤2.0 was the best cutoff value for evaluating myocardial ischemia which yielded a sensitivity of 93.3 ％ and specificity of 89.7％.②Coronary artery stenosis was negatively correlated with CFR (P ＜0.001).ROC curve analysis demonstrated that CFR≤ 1.60 yielded a sensitivity of 92.3％ and specificity of 73.3％ to predict coronary stenosis significantly.Conclusions CFR measured by ATP stress TTDE can evaluate myocardial ischemia of coronary artery disease and predict LAD significant stenosis before CAG.Using CFR and CAG has important clinical value for choosing treatment of stable coronary artery disease.