Effect of immune response mediated by antigen-specific T cells on plaque stability in coronary heart disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of immune response mediated by antigen (oxidized low density lipoprotein, oxLDL)-specific T cells on plaque stability in coronary heart disease.</p><p><b>METHODS</b>Twenty patients with acute myocardial infarction (AMI), 34 with unstable angina pectoris (UAP), 27 with stable angina pectoris (SAP) and 22 control subjects were enrolled in this study. MTS/PMS colorimetric assay was used to measure the proliferative response of the T cells to stimulation to 5 microg/ml oxLDL and detect IFN-gamma concentration produced in the proliferative response. The effect of C-reactive protein (CRP) on the proliferative response of the T cells to oxLDL and IFN-gamma concentration produced was examined in AMI group and UAP group.</p><p><b>RESULTS</b>The proliferative response of T cells to stimulation to 5 microg/ml oxLDL was significantly higher in AMI group and UAP group than in SAP group and the control group (P<0.05). IFN-gamma concentration produced in the proliferative response of the T cells was also significantly higher in AMI group and UAP group than in the other two groups (P<0.05). CRP at 10 microg/ml significantly increased the proliferative response of the T cells to oxLDL and IFN-gamma production in ACS group (P<0.001).</p><p><b>CONCLUSION</b>The immune response mediated by the antigen-specific T cells, especially that mediated by type 1 T helper cells secreting IFN-gamma, may play an important role in the instability of plaques, and CRP may promote the inflammation of atherosclerosis through the effects on the specific immune response to oxLDL.</p>

Relationship between myocardial systolic, diastolic functions and perfusion in coronary artery stenosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the relationship between myocardial systolic, diastolic functions and perfusion in coronary artery stenosis using velocity vector imaging (VVI) and myocardial contrast echocardiography (MCE).</p><p><b>METHODS</b>Stenoses in the anterior descending branch of the coronary artery were induced in 8 dogs. Before and after coronary artery stenosis, two-dimensional images of the left ventricular mastoid muscle section on the short axis at rest and in the peak dose of dobutamine were obtained for evaluation of VVI and MCE. The myocardial blood flow A.beta values, peak systolic strain rate (SRsys) and peak diastolic strain rate (SRdia) in the direction of the circumference of the short axis were measured.</p><p><b>RESULTS</b>At rest, only severe coronary stenosis resulted in significantly lowered SRsys, SRdia and A.beta value of the stenotic bed compared to the values before the stenosis (-1.1-/+0.50 vs -1.62-/+0.50, 1.19-/+0.48 vs 1.75-/+0.51, 0.4-/+0.21 vs 0.80-/+0.47, P<0.05). In stress, SRsys, SRdia and A.beta value of the stenotic bed gradually decreased as coronary stenosis worsened (-4.31-/+1.14 vs -3.20-/+0.98 vs -1.18-/+0.64, 4.51-/+1.13 vs 3.39-/+0.98 vs 1.37-/+0.64. 3.54-/+1.95 vs 1.81-/+0.89 vs 0.82-/+0.42, P<0.05). Both at rest and in stress, good correlations were noted between SRsys and SRdia (r(rest)=0.88, r(stress)=0.96, P<0.01), between SRsys and the standard A.beta values (r(rest)0.56, r(stress)=0.71, P<0.01), and between SRdia and A.beta (r(rest)=0.57, r(stress)=0.72, P<0.01) in the direction of the circumference of the short axis.</p><p><b>CONCLUSIONS</b>Using VVI and MCE, the changes in myocardial perfusion and the systolic and diastolic functions in the direction of the circumference can be observed dynamically. VVI may help assess the condition of myocardial perfusion by evaluating the systolic and diastolic function.</p>

Effect of phospholipid- and albumin-coated microbubbles for myocardial opacification: a comparative study / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of a phospholipid-coated microbubble contrast agent for myocardium opacification in comparison with a albumin-coated microbubble contrast agent (Quanfuxian).</p><p><b>METHODS</b>In 10 dogs with single coronary artery stenosis involving the anterior descending branch or circumflex branch randomly received infusion of the two contrast agents through the femoral vein. The myocardial blood flow, heart rate and blood pressure were analyzed qualitatively and quantitatively. The concentration and the particle diameter of the two contrast agents were determined.</p><p><b>RESULTS</b>The concentration of the phospholipid-coated microbubbles was (1.06-/+0.22) x10(9)/ml, with a diameter of 3.04-/+0.34 microm, similar to the concentration and diameter of Quanfuxian ((1.31-/+0.33)x10(9)/ml and 2.88-/+0.58 microm, respectively, P>0.05). Both of the agents achieved grade three myocardium opacification, and produced no obvious effect on the heart rate and blood pressure. Quantitative analysis of myocardial opacification in terms of myocardial blood volume (A), blood velocity (beta), and blood flow (A x beta) revealed no significant difference between the two agents (P>0.05), and the parameters derived from the two agents showed good correlations (P<0.05, rA=0.809, r beta=0.932, rA.beta=0.925).</p><p><b>CONCLUSION</b>The phospholipid-coated microbubble contrast agent shows good effect for myocardial opacification without significant difference from Quanfuxian. Both of the agents are good ultrasound contrast agents for quantitative analysis of myocardium blood flow.</p>