In recent years, more and more attention has been paid into impairment of central nervous system after diabetes mellitus, including cognitive dysfunction. This paper would review the etiological factor and pathogenesis of cognitive dysfunction in type 2 diabetes mellitus patients.

As an important way to maintain the internal environment of the human body, the renin-angiotensin system (RAS) plays an important role in the diabetic cognitive dysfunction, which may associate with insulin resistance, inflammatory reaction, oxidative stress and other mechanisms. Traditional Chinese Medicine can improve cognitive function of diabetes, in which RAS may play a role.

Learning and memory dysfunction caused by diabetes is gaining an increased attention. Diabetes can significantly increasethe risk of dementia, including vascular dementia and Alzheimer's disease; and diabetes itself can lead to mild or moderate cognition decline.Many clinical and experimental datas indicated that deficiency of insulin or insulin resistance can significantly reduce the threshold of cognitivedysfunction and accelerate the progress of cognitive decline. This paper reviewed the effect of insulin and insulin resistance on cognitivefunction in diabetes.

Objective To explore the differential diagnostic value of speckle-tracking imaging (STI) between dilated cardiomyopathy(DCM) and ischemic cardiomyopathy(ICM).Methods 40 DCM patients,32 ICM patients and 30 normal controls were enrolled for this study.Different views of high frame images of left ventricle were recorded.The time to peak radial strain,circumferential strain and longitudinal strain of 18 myocardial segments were measured by STI,and the maximum differential (Ts-dif) and the standard deviation(Ts-SD) of time to the peak strain were calculated.The left ventricular parameters measured by STI were compared between DCM and ICM,and the diagnostic sensitivity and specificity were investigated by the areas under the receiver operating characteristic (ROC) curves.Results Parameters of different segments of ICM were obviously higher than those of DCM (P ＜ 0.05),and there were significant differences between ICM and DCM.The areas under the ROC curves of Ts-dif and Ts-SD to radial strain were 0.920 and 0.946 respectively.At the cut off of 170 ms and 53 ms for diagnosing DCM and ICM,the sensitivity,specificity and accuracy were 87.5％,87.5％,87.5％ and 90.6％,90％,90.2％ respectively.Conclusions These strain parameters by STI,especially Ts-SD to peak strain can offer a new quantitative diagnostic method in distinguishing DCM from ICM.

ObjectiveTo evaluate regional and global systolic function of left ventricle (LV) after mitral valve replacement(MVR) of different methods by 2-dimensional strain (2DS).MethodsAccording to the operational method whether preserve the posterior leaflet and its subvalvular apparatus,48 patients who underwent MVR were divided into two groups,the preservation group (group A) and the resection group (group B).Echocardiography was examinated before and after MVR and the apical four-chamber view,two-chamber view and long-axis view of LV were acquired.Regional peak strain (Sp) and global strain (GS) of LV longitudinal movement were analysed by 2DS software.Results①Compared to preoperation,the Sp in basal segment of posterior septum and inferior wall and middle segment of lateral wall in group A increased significantly ( P ＜0.01 or P ＜0.05).The Sp of group B were improved in both basal and middle segments of posterior septum ( P ＜0.05),while declined in middle segment of lateral wall and anterior wall,basal segment of lateral wall and apical segment of anterior wall significantly (P ＜0.01 or P ＜0.05).②Compared with group A,subtractions between preoperative and postoperative Sp of group B decreased in middle segment and apical segment of anterior wall,middle segment of lateral wall and middle segment of inferior wall significantly ( P ＜0.01 or P ＜0.05).③The GS of group A increased significantly ( P ＜0.05),while that in group B tended to reduce with no statistical significance ( P ＞0.05).Compared with group A,subtractions between preoperative and postoperative GS of group B droped significantly (P ＜ 0.05).ConclusionsAppropriate preservation of the posterior leaflet and its subvalvular apparatus has morebeneficial effect in improving the early regional and global function of LV after surgery,which would be recommended in MVR.Early regional and global systolic function of LV after MVR could be accurately evaluated by 2DS relatively,which has the application value of guiding clinical treatment and estimating prognosis.

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 investigate the global and regional dyssynchrony of left ventricle in patients with coronary artery disease before and after revascularization by tissue synchronization imaging(TSI).Methods Subjects with the left anterior descending coronary artery(LAD)stenosis＞75% who underwent revascularization(n=26)and normal controls(n=30)were studied with TSI.Echocardiography was performed one day before revascularization,then repeated one month and three month after the operation,respectively.The sample volumes were located at the mid-myocardium of base and middle segments in apical four-,two- and three-chamber view of left ventricle.The time-to-peak velocity(Tp)of all myocardial segments were examined to access the regional dyssynchrony,and the standard deviations of Tp of 12 segments(TSD)were calculated to evaluate the global dyssynchrony.Results Before revascularization,Tp of segments in the anterior wall and the interventricutar septum in patients were more delayed than those of control group(P＜0.01),and the color coding of ischemic segments were red and yellow.After operation,Tp of delayed segments were significant improved,and the color coding turn to yellow or even green,but there was still significant difference of Tp between disease group and control group(P＜0.01 or P＜0.05).TSD decreased gradually on the preoperatative,early postoperative,and later postoperative echocardiogram,and it on each time point of the disease group were all longer than that of control group.An improvement of TSD was observed after revascularization,especially for the three month examination(P＜0.01),but the difference between early and later postoperation was not significant(P＞0.05).Conclusions The asynchronous motion of LV is very obvious in CAD patients.After revascularization,both global and regional dyssynchrony were improved gradually.Moreover,TSI is a convenient and non-invasive way to quantitate left ventricular asynchrony with the parameters.

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.

Objective To evaluate a new computer-aided technique applicable for myocardial contrast echocardiography(MCE) to quantitate automatically calibrated myocardial contrast intensity(CD and to test the feasibility of calibrated CI in assessing myocardial perfusion. To analyze the relationship on myocardial perfusion,regional contractile function and cell apoptosis in stunned myocardium. Methods According to coronary occlusion and reperfusion at different times, rabbits were divided into three groups: 15 min occlusion/30min reperfusion (group Ⅰ ),30 min occlusion / 60min reperfusion (group Ⅱ ) and 120 min occlusion / 60min reperfusion (group Ⅲ ). MCE was performed on all rabbits at baseline,occlusion and after reperfusion,and its images were analyzed by a new computer-aided technique. Myocardial calibrated CI of each segment was measured automatically by software. Percentage wall thickening (WT) of each risk segment at each stage were also measured by echocardiography. The apoptotic index(AI) in regional left myocardial dysfunction was calculated by terminal deoxynucleotidyl transferease-mediated biotinylated deoxyuridine triphosphate nick end labeling(TUNEL ). Results (1) During occlusion, WT in the areas at risk decreased to zero or negative and the calibrated CI values were significantly lower than those at baseline ( P ＜0.01 ). After reperfusion, WT in all risk segment remained depressed, but calibrated CI significantly improved in group Ⅰ and Ⅱ while those remained unchanged in group Ⅲ. (2)AI in risk myocytes were (13. 70 ± 5.48 ) %, (36.25 ± 5.55 ) % and ( 62.06 ± 6. 70 ) %, respectively, both statistically significant difference between the two groups ( P ＜0.05 or P ＜ 0.01 ). AI were negatively correlated to WT and calibrated CI ( r = - 0. 87 and r = - 0. 77, P ＜0.05). Conclusions MCE with computer-aided technique can assess quantitatively myocardial perfusion and regional contractile function. Short-term ischemiareperfusion does not cause myocardial necrosis, but it will lead to myocardial cell apoptosis and the phenomenon of myocardial stunning. Prolonged ischemia, even if given sufficient reperfusion, can lead to apoptosis and necrosis simultaneously.