Résumé
The changes in the tau protein phosphorylation and expression of bcl-2,and bax in rat parietal cortex neurons after focal cerebral ischemia-reperfusion(I/R)were explored,and the relationship between the tau protein phosphorylation and the expression of bax or apoptosis was clarified in order to elucidate the relationship between cerebral infarction and Alzheimer's disease.The rat focal cerebral I/R model was induced by occlusion of the right middle cerebral artery using the intraluminal suture method.The level of tau protein phosphorylation at Ser396,Ser404,Tyr231,Ser199/202 sites and the expression of bcl-2,bax and total tau 5 in rat parietal cortex during focal cerebral ischemia/reperfusion were detected by Western blot.The relationship between the tau protein phosphorylation and the expression of bax,or apoptosis was examined by TUNEL method and double-labeling immunofluorenscence method.The results showed that the level of tau hyperphosphorylation at Ser199/202,Ser396,Ser404,Tyr231 sites and the expression levels of bcl-2,and bax were significantly higher in I/R group than in the sham group,bat the ratio of bcl-2/bax was decreased.Neuronal apoptosis,bax expression and the tau protein hyperphosphorylation were co-localized.It is suggested that Alzheimer's disease-like pathological changes occur after cerebral I/R.The highly abnormal phosphorylation of tau protein plays a key role in cerebral I/R-induced apoptosis.The cerebral infarction may contribute to Alzheimer's disease occurrence and development.
Résumé
Transthoracic echocardiographic characteristics of 17 cases of cardiac amyloidosis (CA),a rare disease in China, were analyzed in order to improve the understanding of the disease. Seventeen cases of biopsy-proven CA, admitted to Wuhan Union Hospital from June 1994 to September 2008 were retrospectively reviewed. Twenty normal volunteers served as control group. Left atrial and ventricular functions and mitral inflow velocity were measured by two-dimensional, and Doppler echocardiography, and tissue Doppler imaging (TDI)-derived peak systolic wall motion velocities (Sv), peak early diastolic wall motion velocities (Ev), and peak late diastolic wall motion (Av) were measured at the septunm. Lateral, inferior and anterior comers of mitral annulus from the apical 4- and 2 chamber views. Compared with the control group, the interventricular septal thickness (IVSd), the left ventricular posterior wall (LVPWd), right ventricular transverse diameter (RVTDd) near the end of diastole and the interauricular septum thickness (IASs), left atrial anteroposterior diameter (LAADs), right atrial transverse diameter (RATDs) near the end of systole were increased significantly (all P<0.05) and left ventricular ejection fraction (LVEF) decreased (P<0.05) in the CA group.Compared with the control group, Sv, Ev at each wall and Av at almost all walls were significantly decreased in the CA group. In the CA group, Myocardial echoes of interventricular septum and free wall of left ventricle were enhanced evidently and distributed unevenly. The echoes presented as ground glass-like images, with some spotty hyper echoes. Both atria were enlarged, and LVEF decreased, with diastolic function impaired, and mild-moderate hydropericardium found in the CA group. It was concluded that echocardiography was a relatively sensitive and highly specific non-invasive method for the diagnosis of CA.