Myocyte Enhancer Factor 2A Plays a Central Role in the Regulatory Networks of Cellular Physiopathology.

Cell regulatory networks are the determinants of cellular homeostasis. Any alteration to these networks results in the disturbance of cellular homeostasis and induces cells towards different fates. Myocyte enhancer factor 2A (MEF2A) is one of four members of the MEF2 family of transcription factors (MEF2A-D).

MEF2A Is the Trigger of Resveratrol Exerting Protection on Vascular Endothelial Cell.

Both resveratrol and myocyte enhancer factor 2A (MEF2A) may protect vascular endothelial cell (VEC) through activating the expression of SIRT1. However, the relationship between resveratrol and MEF2A is unclear. We aimed to investigate the deeper mechanism of resveratrol in protecting vascular endothelial cells and whether MEF2A plays a key role in the protective function of resveratrol.

Inhibition of platelet activation and aggregation by furostanol saponins isolated from the bulbs of Allium macrostemon Bunge.

Three new furostanol saponins (FSs) were recently isolated from the dried bulbs of Allium macrostemon and were shown to have antiplatelet effects. This study investigated the inhibitory capabilities of these compounds on adenosine diphosphate (ADP)-induced human platelet activation. FS-1, when compared with the other 2, had a potent inhibitory effect on ADP-induced platelet aggregation and on the expression of P-selectin and integrin β-3.

[Role of sphingosine 1-phosphate receptor signaling in hematopoietic stem/progenitor cell transmigration].

Objective: To determine the role of sphingosine 1-phosphate receptor (S1PRs ) signaling in CD34+ hematopoietic stem/progenitor cell transmigration.

Methods: CD34(+) cells were separated by Ficoll density gradient centrifugation and incubated in DMEM medium with 10% fetal calf serum. The cells were pretreated by FTY720, with or without pertussis toxin (PTX) and antiCXCR4 mAb in the medium, followed by addition of 100 ng/ml SDF-1 into the lower chamber of a Costar 24-well transwell.

[Targeted adhesion of platelet receptor-specific microbubble agent to thrombus in vitro].

Objective: To examine the thrombus-targeting effect of platelet receptor-specific lipid microbubbles.

Methods: The targeted microbubbles were prepared by coupling Arg-Gly-Asp-Ser (RGDS) with the lipid microbubbles, which were added to the microthrombus generated by platelet aggregation. The effects of the targeted microbubbles on the ultrasonic signal was observed in an artificial thrombus model.

[Establishment of a modified canine model of acute cardiac insufficiency].

Objective: To establish a canine model of acute cardiac insufficiency (ACI) by coronary artery occlusion and right ventricular pacing.

Methods: Twelve dogs were subjected to rapid ventricular pacing after ligation of the left anterior descending coronary artery (LAD), to induce the cardiac output (CO) to reduce by 25%; and 50%; from the basal level. The arterial pressure (AP), arterial oxygen saturation (SaO(2)), mean right atrial pressure (mRAP), mean pulmonary capillary wedge pressure (mPCWP), and systemic vascular resistance (SVR) were measured in the dogs according to different CO conditions.

[Ultrasound microbubbles promote thrombolysis of rabbit femoral artery thrombus].

Objective: To evaluate the efficacy of intravenous ultrasound microbubbles for thrombolysis of arterial thrombus without using thrombolytic drugs.

Methods: Twelve rabbit models of acute bilateral femoral artery thrombosis were established and 6 of them received transcutaneous ultrasound and intravenous albumin microbubble treatment for thrombosis on one side while only microbubble treatment for the other side. The other 6 rabbits received ultrasound treatment on one side but no treatment on the other to serve as the control group.

[Conditions of contrast ultrasound that affect the proliferation of rat smooth muscle cells].

Objective: To investigate the effect of an echo-contrast agent on the proliferation of rat smooth muscle cells under different ultrasound conditions.

Methods: The vascular smooth muscle cells of rats were cultured with echo-contrast agent in 96-well plates, followed by exposure to ultrasound of different conditions. Trypan blue staining was performed 48 h later, and the proliferation of the cells observed by MTT assay.

[Effect of echo-contrast agent on rat vascular smooth muscle cell proliferation during ultrasound exposure].

Objective: To investigate the effect of echo-contrast agent on rat vascular smooth muscle cell (VSMC) proliferation in the presence of ultrasound exposure.

Methods: The VSMCs of rats were cultured in 6-well plates with or without the echo-contrast agent and stained with trypan blue at 3, 24, and 48 h respectively after ultrasound exposure for 1 min at 2 MHz, 0.25 mechanical index (MI).

[Role of platelet membrane glycoprotein II b/III a receptor activation in no-reflow after myocardial reperfusion].

Objective: To observe the changes in the activity of platelet glycoprotein (GP) IIb/IIIa receptor following the occurrence of no-reflow after myocardial reperfusion, to explore the measures for clinical management of this condition.

Methods: Nine canine models of no-reflow following myocardial ischemia verified by reperfusion myocardial contrast echocardiography were used in this investigation. The peripheral venous blood (PVB) and sinus venous blood (SVB) were sampled before myocardial reperfusion (after a 3-hour myocardial ischemia) and after a 3-hour reperfusion for determinating GP IIb/IIIa receptor activities by means of enzyme-linked immunosorbent assay (ELISA).

Value of echocardiography for observing left ventricular hypertrophy in the diagnosis of myocardial microvascular damage in hypertensives.

Objective: To investigate the value of the echocardiographic observation of the left ventricular hypertrophy (LVH) in diagnosing myocardial microvascular damage in patients with essential hypertension (EH).

Methods: After intravenous injection with Quanfuxian (a contrast agent consisting of albumin and C3F8 prepared by Nanfang Hospital), the values of A (the maximum number of microbubbles accumulating in the local tissues for assessing the density of local microvessels), beta (the filling velocity of contrast agent for evaluating local blood flow velocity) and A x beta (the product of A and beta for estimating local myocardial blood flow) at rest and after dipyridamole injection were measured by intermittent harmonic imaging with myocardial contrast echocardiography (MCE). The ratios of A and beta along with the microvascular coronary flow velocity reserve (CFVR) were also calculated.

[Discrepancy between the blood flow in hyperperfused epicardial coronary vessels and myocardial microcirculation following reperfusion: a study in canines].

Objective: To investigate the hemodynamic changes in the epicardial coronary blood flow (ECBF) and myocardial microcirculation (MMC) during reactive hyperemia (RH) in response to reperfusion following 2-min ischemia in the left anterior descending coronary artery of canines.

Methods: Twelve adult mongrel dogs were used, whose left anterior descending coronary artery was separated and ligated for 2 min twice below the first branch. The heart rate, systolic blood pressure, diastolic blood pressure, mean blood pressure, ECBF and MMC were measured respectively before and after the ligation and at 5, 10, 15, 30, 45, 60, 90 and 120 s after reperfusion.