Objective To detect the expressions of Lingo-1 and myelin associated protein in the white matter and hippocampus of ovariectomized rats after short-term estrogen replacement therapy in order to explore the possible mechanisms for the effects of estrogen on the brain myelin sheaths and cognitive function.Methods 24 middleaged (9-12 months) female Sprague-Dawley (SD) rats were bilaterally ovariectomized (OVX) and randomly divided into vehicle replacement (OVX+Veh) group and estrogen replacement (OVX+E) group.After one month ERT,The spatial learning and memory ability of all rats were assessed with Morris water maze.Then,10 rats were randomly selected from each group.The ultrastucture of myelin sheaths in the cerebral white matter and hippocampus were observed,and the protein expression of MBP and Lingo-1 were investigated with Western blot and immunohistochemical staining.Results The escape latencies of OVX+E rats in navigation test were significantly shorter than that of OVX+Veh rats(P＜0.05).The myelin sheaths in the white matter and hippocampus of OVX+Veh rats showed obviously degeneration.In the OVX+E group,the expression of MBP in the white matter and hippocampus was significantly higher than that of OVX+Veh group(P＜0.05),however,the expression of Lingo-1 was significantly lower than that of OVX +Veh group (P＜ 0.05).Conclusions One-month ERT has significant beneficial effects on the spatial learning capacity and myelin sheaths in the white matter and hippocampus.The protective effects may be related to estrogen-induced downregulation of the Lingo-1 expression in the white matter and hippocampus of rats.

To understand the local hemodynamics of modified TF-AHCB carotid bifurcation model, using particle image velocimetry technique to measure the instantaneous velocity distribution of the model attatched to a circuit. The velocity was controlled by regulating the height of the reservoir. The working fluid consists of glycerine and water mixture with viscosity of 3.75 mPa.s similar to human blood. Instantaneous velocity fields were obtained by PIV and the shear stresses were calculated according to the velocity. The results showed that inside the model, there were a large flow separation and an anticlockwise rotating vortex on the lateral wall of ICA, The location and distance of the vortex changed with the flow velocity. The higher the flow velocity, the smaller the vortex distance, and the farther the location. The shear stresses on the lateral wall were significantly lower in all work condition. And there a low shear stress kernel when the velocity was lower than 0.839 m/s. The location of the low shear stress was just the position of atherosclerosis. The flow pattern inside the model consists of large flow separation and vortex zones. And there are low shear stress zones at the lateral wall of ICA, Where are thought to be associated with the genesis of atherosclerosis.
Blood Flow Velocity ; Carotid Arteries ; physiology ; Models, Cardiovascular ; Pulsatile Flow ; Regional Blood Flow ; physiology ; Rheology ; methods ; Stress, Mechanical

Chondrosarcoma ; diagnosis ; Female ; Humans ; Magnetic Resonance Imaging ; Middle Aged ; Positron-Emission Tomography ; Pulmonary Artery ; pathology