Blood pH in coronary artery microthrombosis of rats

Objective: To study the mechanism and significance of pH change in the coronary artery microthrombosis of rats. Methods: After the sodium laurate-induced model of coronary artery microthrombosis of rats was constructed, the vascular endothelial cells were separated and then cultured in the mediums with different pH values for 24 h. Enzyme linked immunosorbent assay was used to detect the content of von Willebrand factor (vWF) in the medium; while the real-time PCR and western blot assay were used to detect the expression of fibrinogen-like protein 2 (FGL2) at the mRNA and protein level. The comprehensive evaluation was performed to discuss the effect of pH change on the coronary artery microthrombosis of rats. Results: The expression level of vWF detected by enzyme linked immunosorbent assay was 336.67 ± 24.95, 311.33 ± 14.98, 359.67 ± 39.63, 354.67 ± 49.01 and 332.00 ± 33.42 (pg/mL) respectively; while the expression of vWF in the model group was 570.00 ± 57.94, 524.67 ± 57.94, 437.00 ± 95.38, 415.33 ± 44.38 and 444.67 ± 74.31 respectively. Being cultured under the different pH values, the relative expression level of FGL2 mRNA in the model group was 7.93 ± 0.93, 6.70 ± 0.70, 5.03 ± 0.32, 5.13 ± 0.40 and 5.57 ± 0.83 respectively. Conclusions: The coronary artery microthrombosis of rats can cause the high expression and secretion of vWF. Meanwhile, FGL2 is also up-regulated in the thrombosis and such up-regulation is more significant in the condition with low pH, which indicates that the low pH condition may be one of factors that contribute to the cardiovascular diseases.

Blood pH in coronary artery microthrombosis of rats

OBJECTIVE@#To study the mechanism and significance of pH change in the coronary artery microthrombosis of rats.@*METHODS@#After the sodium laurate-induced model of coronary artery microthrombosis of rats was constructed, the vascular endothelial cells were separated and then cultured in the mediums with different pH values for 24 h. Enzyme linked immunosorbent assay was used to detect the content of von Willebrand factor (vWF) in the medium; while the real-time PCR and western blot assay were used to detect the expression of fibrinogen-like protein 2 (FGL2) at the mRNA and protein level. The comprehensive evaluation was performed to discuss the effect of pH change on the coronary artery microthrombosis of rats.@*RESULTS@#The expression level of vWF detected by enzyme linked immunosorbent assay was 336.67 ± 24.95, 311.33 ± 14.98, 359.67 ± 39.63, 354.67 ± 49.01 and 332.00 ± 33.42 (pg/mL) respectively; while the expression of vWF in the model group was 570.00 ± 57.94, 524.67 ± 57.94, 437.00 ± 95.38, 415.33 ± 44.38 and 444.67 ± 74.31 respectively. Being cultured under the different pH values, the relative expression level of FGL2 mRNA in the model group was 7.93 ± 0.93, 6.70 ± 0.70, 5.03 ± 0.32, 5.13 ± 0.40 and 5.57 ± 0.83 respectively.@*CONCLUSIONS@#The coronary artery microthrombosis of rats can cause the high expression and secretion of vWF. Meanwhile, FGL2 is also up-regulated in the thrombosis and such up-regulation is more significant in the condition with low pH, which indicates that the low pH condition may be one of factors that contribute to the cardiovascular diseases.

Effects of hypokalemia on transmural dispersion of ventricular repolarization in left ventricular myocardium

OBJECTIVE@#To observe effects of hypokalemia on transmural heterogeneity of ventricular repolarization in left ventricular myocardium of rabbit, and explore the role of hypokalemia in malignant ventricular arrhythmia (MVA).@*METHODS@#A total of 20 rabbits were randomly divided into control group and hypokalemic group. Isolated hearts in the control group were simply perfused with modified Tyrode's solution, and were perfused with hypokalemic Tyrode's solution in hypokalemic group. Ventricular fibrillation threshold (VFT), 90% monophasic action potential repolarization duration (APD90) of subepicardial, midmyocardial and subendocardial myocardium, transmural dispersion of repolarization (TDR) and C×43 protein expression in three layers of myocardium were measured in both groups.@*RESULTS@#VFT in the control group and the hypokalemic group were (13.40 ± 2.95) V, and (7.00 ± 1.49) V, respectively. There was a significant difference between two groups (P<0.01). APD90 of three myocardial layers in the hypokalemic group were significantly prolonged than those in the control group (P<0.01). ΔAPD90 in the hypokalemic group and the control group were (38.10 ± 10.29) ms and (23.70 ± 5.68) ms, and TDR were (52.90 ± 14.55) ms and (36.10 ± 12.44) ms, respectively. ΔAPD90 and TDR in the hypokalemic group were significantly higher than those in the control group (P<0.05), and the increase in APD90 of midmyocardium was more significant in the hypokalemic group. Cx43 protein expression of all three myocardial layers were decreased significantly in the hypokalemic group (P<0.01), and ΔCx43 was significantly increased (P<0.05). Reduction of Cx43 protein expression was more significant in the midmyocardium.@*CONCLUSIONS@#Hypokalemic can increase transmural heterogeneity of C×43 expression and repolarization in left ventricular myocardium of rabbit, and decrease VFT and can induce MVA more easily.

Characterization of the biological activities of lyophilized recombinant adenovirus expressing the triple mutant of hypoxia inducible factor-1α / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the influence of lyophilization on the biological activity of recombinant adenovirus-mediated triple mutant of hypoxia inducible factor-1α (Ad-HIF-1α-564/402/803).</p><p><b>METHODS</b>Ad-HIF-1α-564/402/803 was amplified from HEK293A cells and purified by ultracentrifugation in CsCl gradient solutions. The infection efficiency was observed by X-gal staining. The lyophilized adenovirus was prepared under appropriate conditions. Before and after lyophilization, the effect of Ad-HIF-1α-564/402/803 on hMVEC proliferation was evaluated by MTS assay. The recombinant adenovirus was confirmed by PCR and DNA sequence analysis before and 1 day, 6 months and 12 months after lyophilization, and hMVECs infected with Ad-HIF-1α-564/402/803 at these time points were examined for HIF-1α protein expression using Western blotting.</p><p><b>RESULTS</b>No significant changes were observed in the effect of lyophilized Ad-HIF-1α-564/402/803 on hMVECs proliferation at the optimal multiplicity of infection of 100 pfu/cell (P>0.05). At the 4 time points, the recombinant adenovirus HIF-1α showed no structural alterations or significant changes in the expression level of HIF-1α protein in the transfected hMVECs (P>0.05).</p><p><b>CONCLUSION</b>Lyophilized Ad-HIF-1α-564/402/803 can maintain its biological activities for a long time.</p>

Effect of granulocyte colony stimulating factor EPC on cardiac function in patients with heart failure after myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes of cardiac function following treatment with granulocyte colony stimulating factor (G-CSF) in patients with heart failure after myocardial infarction.</p><p><b>METHODS</b>Thirty-eight patients with heart failure after myocardial infarction were randomized into G-CSF treatment group and control group. All the patients received conventional treatment (medication and interventional therapy), and the patients in treatment group were given additional G-CSF (600 µg/day) for 7 consecutive days. The plasma level of brain-type natriuretic peptide (BNP) and the number of endothelial progenitor cells (EPCs) in the peripheral blood were detected before and at 7 days and 4 months after the treatment. The cardiac functions (LVSD, EDV, and LVEF) were evaluated by ultrasonic imaging before and at 2 weeks and 4 months after the treatment.</p><p><b>RESULTS</b>The number of EPCs was significantly higher in the treatment group than in the control group after the treatment especially at 7 days (P<0.01). In both groups, BNP level was lowered significantly after the treatment to recover the normal level (P<0.01). The cardiac functions were improved in all the patients at 7 days and 4 months after the treatment, and the improvement was more obvious in the treatment group (P<0.05), especially in terms of LVEF at 4 months after the treatment (P<0.01).</p><p><b>CONCLUSION</b>EPC mobilization by G-CSF can effectively improve the cardiac functions and lessen ventricular remodeling in patients with heart failure after myocardial infarction.</p>

Comparison of right atrial matrix metalloproteinase expression between patients with unstable angina and myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare right atrial structural remodeling and the expression of matrix metalloproteinase (MMP) and tissue inhibitors (TIMP) between patients with unstable angina (UA) and myocardial infarction (MI).</p><p><b>METHODS</b>Right atrial appendages were obtained from 18 patients with UA and 22 patients with MI undergoing coronary artery bypass grafting (CABG) operations. MMP-1, -3, -7, -9 and TIMP-1 protein expressions were detected by immunohistochemistry and RT-PCR. Echocardiography was performed before CABG.</p><p><b>RESULTS</b>The left and right atrial diameter, left ventricular diameter and mRNA levels of MMP-3, MMP-9 and TIMP-1 were significantly higher in MI group than those in UA group [LAD: (40.8 +/- 4.2) mm vs. (33.1 +/- 5.1) mm, P < 0.01; RAD: (44.1 +/- 6.8) mm vs. (28.8 +/- 6.0) mm, P < 0.01; LVEDD: (48.9 +/- 6.0) mm vs. (39.7 +/- 7.1) mm, P < 0.05; MMP-3: 0.39 +/- 0.18 vs. 0.28 +/- 0.07, P < 0.05; MMP-9: 0.81 +/- 0.21 vs. 0.55 +/- 0.20, P < 0.01; TIMP-1: 1.79 +/- 0.89 vs. 0.94 +/- 0.47, P < 0.01]. MMP-1, MMP-7 levels were similar between the 2 groups (MMP-1: 0.14 +/- 0.06 vs. 0.10 +/- 0.08, P > 0.05; MMP-7: 0.25 +/- 0.05 vs. 0.23 +/- 0.06, P > 0.05).</p><p><b>CONCLUSION</b>Right atrial up-regulation of MMP-3, MMP-9 and TIMP-1 levels may contribute to the right atrial structural remodeling in MI patients.</p>

Role of matrix metalloproteinase and tissue inhibitor of metalloproteinase in atrial structural remodeling in patients with atrial fibrillation / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between atrial structural remodeling and the expressions of matrix metalloproteinase (MMPs) and their tissue inhibitors (TIMPs) in atrial fibrillation (AF).</p><p><b>METHODS</b>Biopsy samples of the right atrial appendages were collected from 20 patients with sinus rhythm and 30 with AF undergoing heart valve replacement surgery for rheumatic heart diseases. All the patients received echocardiographic examination preoperatively. MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 protein expressions were detected by immunohistochemistry and RT-PCR.</p><p><b>RESULTS</b>Compared with those in patients with sinus rhythm, the AF patients had significantly increased left and right atrial diameters and mRNA levels of MMP-3, -7, -9 and TIMP-1, -2, -3, -4 (P<0.01). MMP-1 expression also showed an increase in AF patients, but the difference was no statistically significant from that in patients with sinus rhythm.</p><p><b>CONCLUSION</b>The expressions of MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 increase in fibrillating atrial tissue, which may contribute to atrial structural remodeling and atrial dilatation in AF patients.</p>

Effect of different doses of recombinant adenovirus mediated hypoxia-inducible factor-1alpha on angiogenesis in ischemic lower hind limb of rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of recombinant adenovirus-mediated hypoxia-inducible factor-1alpha (Ad-HIF-1alpha) at different doses on angiogenesis in a rabbit model of hind limb ischemia.</p><p><b>METHODS</b>Left hind limb ischemia was induced in 45 Zealand white rabbits by ligation of the left femoral artery. The rabbits were randomly divided into 5 groups (n=9) to receive intramuscular injections of 0.5 ml saline, 2x10(10) PFU empty vector (Ad-null), or different doses of Ad-HIF-1alpha (2x10(9), 2x10(10) or 2x10(11) PFU) immediately after the operation. On the 7th day after the operation, real-time PCR was used to detect the expression of HIF-1alpha mRNA in the skeletal muscles. Immediately and on the 14th and 28th days after the operation, contrast enhanced ultrasound (CEU) was used to observe the blood perfusion of the hind limb. On the 28th day postoperatively, immunohistochemistry for CD31 was performed to evaluate the microvascular density (MVD).</p><p><b>RESULTS</b>Real-time PCR showed that Ad-HIF-1alpha significantly increased the expression of HIF-1alpha mRNA (P<0.01) in a dose-dependent manner as compared with that in the saline and Ad-null groups (P<0.01). CEU revealed greater blood perfusion in the hind limb of rabbits in association with increased dose of Ad-HIF-1alpha (P<0.05 or P<0.01); similar changes in the MVD was observed following Ad-HIF-1alpha injections as shown by immunohistochemistry (P<0.05 or P<0.01). No significant differences were found either in the blood perfusion or MVD between saline and Ad-null groups (P>0.05).</p><p><b>CONCLUSION</b>Ad-HIF-1alpha can dose-dependently promote the angiogenesis in the ischemic limb of rabbits.</p>

Effects of recombinant adenovirus-mediated triple mutant of hypoxia inducible factor-1alpha in modulating angiogenesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of recombinant adenovirus-mediated triple mutant of hypoxia inducible factor-1alpha (Ad-HIF-1alpha-564/402/803) in modulating angiogenesis in vitro.</p><p><b>METHODS</b>The recombinant adenoviruses Ad-lacZ, Ad-Null, Ad-HIF-1alpha-nature, and Ad-HIF-1alpha-564/402/803 were amplified in HEK293A cells and purified by ultracentrifugation in CsCl step gradient solutions, and the adenoviral titer was determined by end-point dilution assay. The recombinant adenovirus was confirmed by PCR and DNA sequence analysis, and the infection efficiency was observed by X-gal staining. Human microvascular endothelial cells (HMVECs) were infected with Ad- HIF-1alpha-564/402/803, Ad- HIF-1alpha-nature, or Ad-Null to compare the number of capillary-like tube structures in vitro. The effect of Ad- HIF-1alpha-564/402/803, Ad-HIF-1alpha-nature, and Ad-Null on angiogenesis was evaluated using a chick embryo chorioallantoic membrane (CAM) model.</p><p><b>RESULTS</b>PCR and gene sequencing suggested the correct construction of the recombinant adenovirus HIF-1alpha, and the adenoviral titer reached 1011-1012 PFU/ml. Infection of the hMVECs with Ad-HIF-1alpha-564/402/803 at the optimal multiplicity of infection of 100 pfu/cell resulted in a significantly greater number of capillary-like tube structures than infection by Ad-HIF-1alpha-nature and Ad-Null (P=0.000). Ad-HIF-1alpha-564/402/803 group showed significantly higher microvessel density than Ad-HIF-1alpha-nature, Ad-Null, and PBS groups, with also higher angiogenesis area to CAM area ratio (P=0.01, 0.000, and 0.000, respectively).</p><p><b>CONCLUSION</b>The triple mutant Ad-HIF-1alpha-564/402/803 can obviously promote the formation of capillary-like tube structures in vitro and modulate angiogenesis in the CAM model, suggesting the capacity of Ad-HIF-1alpha-564/402/803 in promoting angiogenesis under normoxic condition.</p>

Changes of endothelial function indices and their relation to platelet activation in idiopathic atrial fibrillation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of endothelial function indices and their relation to platelet activation in patients with idiopathic atrial fibrillation (AF).</p><p><b>METHODS</b>We studied 61 patients with idiopathic AF with 34 age- and sex-matched healthy persons as control. Platelet counts in the blood were tested, and plasma levels of NOx were analyzed using Griess method. The plasma levels of von Willibrand factor (vWF) and soluble P-selectin (sP-selectin) were determined using enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Compared to healthy control, the patients with idiopathic AF had significantly lower levels of plasma NOx (18.2-/+7.3 vs 24.3-/+7.8 micromol/L, P=0.049) and higher levels of plasma sP-selectin (25.6-/+6.2 vs 22.4-/+4.8 ng/ml, P=0.007). No significant differences were found in the platelet counts or plasma vWF levels between the two groups. A significant inverse correlation was found between plasma NOx and sP-selectin (r=-0.405, P=0.025) in patients with idiopathic AF.</p><p><b>CONCLUSION</b>AF per se may impair the endothelial function and activate platelet function, suggesting the role of endothelial dysfunction in activated platelet function in AF patients.</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 erythropoietin on reperfusion arrhythmias in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of erythropoietin (EPO) on reperfusion arrhythmias in rats and identify the possible mechanism involved.</p><p><b>METHODS</b>Forty-five SD rats were randomized into a sham-operated group and 4 cardiac ischemia/reperfusion (IR) injury groups, which were further divided into IR group, LY294002 group, EPO group, and EPO+LY294002 group. Cardiac IR injury was induced in the 4 IR injury groups by ligating the left anterior descending branch of the coronary artery (LAD) for 30 min followed by reperfusion for 3 h, with subsequent treatments accordingly. The occurrence of arrhythmias was monitored and scored during experiment, and the levels of serum CK-MB and cTnI were detected. The content of MDA in the myocardium was determined by thiobarbituric acid (TBA) method, and the content of SOD by xanthine oxidase method.</p><p><b>RESULTS</b>The arrhythmia score in EPO group was significantly lower than those in IR, LY294002 and EPO+ LY294002 groups (P<0.05). The levels of serum CK-MB and cTnI were significantly lower in EPO group than in the other 3 IR groups (P<0.001). The EPO group showed also significantly lower MDA content (P<0.001) and higher SOD content than the other 3 IR groups (P<0.001).</p><p><b>CONCLUSION</b>EPO at the dose of 1000 mg/kg decreases the incidence of reperfusion arrhythmias in rats, and this effect can be attenuated by LY294002 pretreatment, suggesting that the cardioprotective effect of EPO involves antioxidation mediated by the phosphoinositide 3-kinase (PI3K) pathway.</p>

Plasma matrix metalloproteinases-2 and -9 levels are elevated in patients with acute coronary syndrome and coronary chronic total occlusion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in plasma matrix metalloproteinases-2 and -9 (MMP2 and MMP9, respectively) levels in patients with different types of coronary heart diseases (CHD), and assess the value of MMP2/MMP9 detection in predicting acute coronary syndrome (ACS).</p><p><b>METHODS</b>According to the findings by coronary angiography and the clinical manifestations, 118 patients were divided in ACS group including 30 patients with unstable angina pectoris (UAP) and 19 with acute myocardial infarction (AMI) and non-ACS group including 23 patients with stable angina pectoris (SAP) and 21 with chronic total occlusion (CTO) of the coronary artery. Twenty-five individuals with normal coronary artery (NCA) served as the control group. Plasma levels of MMP9 and MMP2 were determined in these subjects using enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Both the ACS and non-ACS groups showed significantly higher MMP9 and MMP2 levels than the NCA group (P<0.05), and MMP2 and MMP9 levels were significantly higher in ACS group than in non-ACS group (P<0.05). Compared with the NCA group, the UAP, AMI and CTO subgroups showed obvious increases in plasma MMP2 and MMP9 levels (P<0.01). Significantly increased MMP9, but not MMP2 level was noted in AMI subgroup in comparison with SAP (P<0.01) and UAP subgroups (P<0.05); both MMP2 and MMP9 levels were elevated in CTO subgroup in comparison with those in SAP (P<0.001), UAP (P<0.01), and AMI subgroups (P<0.05).</p><p><b>CONCLUSION</b>Increased MMP2 and MMP9 levels in patients with CHD suggest the instability of the atherosclerotic plaque in correlation to the severity of ACS, and may serve as good indicators for the prediction of ACS and diagnosis of CTO of the coronary artery.</p>

Effects of oxygen and calcium on the expression of wild-type and mutated hypoxia-inducible factor-1alpha eukaryotic vectors in HEK293 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of oxygen and calcium on the expression of eukaryotic vectors harboring wild-type or mutated hypoxia-inducible factor-1alpha (HIF-11alpha) in HEK293 cells.</p><p><b>METHODS</b>HEK293 cells were transiently transfected with pcDNA3.1+/HIF-11alpha, pcDNA3.1+/HIF-11alpha-564Ala and pcDNA3.1+/HIF-11alpha-564Ala-803Ala via lipofectin. Western blotting were used to detect HIF-11alpha protein after normoxic or hypoxic exposure of the transfected HEK293 cells in the presence or absence of Ca(2+). The levels of vascular endothelial growth factor (VEGF) mRNA in the transfected cells in normoxic condition was detected using RT-PCR.</p><p><b>RESULTS</b>The levels of HIF-11alpha protein and VEGF mRNA increased in HEK293 cells transfected with the vectors harboring mutated HIF-11alpha, but not in the cells transfected with wild-type HIF-11alpha vectors in normoxia. Hypoxia increased the levels of HIF-11alpha protein in the cells transfected with wild-type HIF-11alpha vectors, which was inhibited by the application of Ca(2+). Ca(2+) showed no inhibitory effect on HIF-11alpha levels in HEK293 cells transfected with the vectors containing mutated HIF-11alpha.</p><p><b>CONCLUSION</b>The protein products of pcDNA3.1+/HIF-11alpha-564Ala and pcDNA3.1+/HIF-11alpha- 564Ala-803Ala in HEK293 cells enhance the cell tolerance to oxygen and protease.</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>

Mechanism of recombinant adenovirus-mediated mutations of hypoxia inducible factor 1alpha in modulation of cell apoptosis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanism by which recombinant adenovirus (Ad)-mediated mutations of hypoxia inducible factor 1alpha (Ad-HIF-1alpha-Ala564-Ala803) regulates cell apoptosis.</p><p><b>METHODS</b>LoVo cells were infected with recombinant Ad-HIF-1alpha-Ala564-Ala803 and control virus Ad-lacZ under normoxia condition. Real-time PCR was used to detect HIF-1alpha and p21WAF1/CIP1 mRNA expressions at different time points. Western blotting was employed to verify HIF-1alpha and p21WAF1/CIP1 protein expression. Hoechst 33342 flourescein staining was performed to observe the ratio of apoptotic LoVo cells.</p><p><b>RESULTS</b>The expression levels of HIF-1alpha mRNA and protein increased after infection with Ad-HIF-1alpha- Ala564-Ala803, accompanied by an increase in p21WAF1/CIP1 mRNA and protein expressions. The apoptotic ratio was significantly higher in LoVo cells infected with recombinant Ad-HIF-1alpha-Ala564-Ala803 (16.2%) than in the control cells (5.5%, P=0.00).</p><p><b>CONCLUSION</b>HIF-1alpha may induce cell cycle arrest by up-regulating p21WAF1/CIP1 expressions to promote LoVo cell apoptosis.</p>

Construction and identification of adenovirus vector for double-mutant human hypoxia-inducible factor-1alpha gene / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct an adenovirus vector containing the double-mutant hypoxia-inducible factor-1alpha (HIF-1alpha) gene for exploring the therapeutic angiogenesis for coronary heart disease.</p><p><b>METHODS</b>Human double-mutant HIF-1alpha cDNA was obtained from PCR of pShuttle-2-HIF-1alpha containing the mutant HIF-1alpha gene (564). The recombinant adenoviral plasmid containing mutant HIF-1alpha cDNA was constructed by ligation of recombinant pShuttle2 containing double-mutant HIF-1alpha cDNA and Adeno-X viral DNA, followed by its identification and transfection into adenoviral packaging cells HEK293 via lipofectamine 2000.</p><p><b>RESULT AND CONCLUSION</b>The recombinant pAdeno-HIF-1alpha was correctly constructed and verified by restriction endonuclease and DNA sequencing analyseis. This recombinant adenovirus containing the double-mutant HIF-1alpha gene may facilitate further investigation of mutant HIF-1alphagene therapy for coronary heart disease.</p>

Modulation of inflammatory cytokines by ATP-binding cassette A1 in THP-1 macrophages / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of ATP-binding cassette A1 (ABCA1) on intercellular cell adhesion molecule type 1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1) and interleukin-1beta (IL-1beta) in THP-1 macrophages stimulated with 8-Br-cAMP to identify a possible new mechanism that ABCA1 contributes to atherosclerogenesis (AS).</p><p><b>METHODS</b>Monocytic THP-1 cells were cultured in the presence of 100 nmol/L phorbol myristate acetate (PMA) for 72 h to transform the cells into THP-1 macrophages. After the macrophages were stimulated with 8-Br-cAMP (final concentration 0.5 mmol/L) for 3, 6, 12 and 24 h respectively, the amounts of ABCA1, ICAM-1 and MCP-1 mRNA were examined by real-time fluorescent quantitative RT-PCR, and the protein amounts of ABCA1, ICAM-1, MCP-1 and IL-1beta were determined by Western blotting and enzyme-linked immunosorbent assay (ELISA). Phosphorothioate antisense oligonucleotides of ABCA1 were add into the culture media at a final concentration of 100 nmol/L and the experiments were repeated.</p><p><b>RESULTS</b>ABCA1, ICAM-1 and MCP-1 mRNA and protein and IL-1beta protein were increased in the macrophages after stimulation with 8-Br-cAMP for 6 and 12 h. The mRNA expressions of ABCA1, ICAM-1 and MCP-1 were decreased significantly at 3 and 6 h (P<0.01), and the protein expressions of ABCA1, ICAM-1, MCP-1 and IL-1beta declined significantly at 12 and 24 h (P<0.01) after transfection of the macrophages with antisense oligonucleotides of ABCA1.</p><p><b>CONCLUSION</b>ABCA1 can increase the expressions of the inflammatory cytokines in THP-1 macrophages stimulated by 8-Br-cAMP and plays a role in the pathogenesis of AS.</p>

A novel polymorphism in the ATP-binding cassette transporter A1 gene (M233V) in Chinese patients with coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To identify ATP-binding cassette transporter A1 (ABCA1) gene polymorphism in Chinese patients with coronary artery disease (CAD).</p><p><b>METHODS</b>Single Nucleotide Polymorphisms in the ABCA1 gene were detected by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP)-DNA sequence and restriction-fragment length polymorphism (RFLP) method in 112 patients with CAD.</p><p><b>RESULTS</b>A novel polymorphism in the ABCA1 gene was found in two patients: M233V which exists in exon7 of ABCA1 gene and it's cDNA location is A1092G and converse 233 amino acid from Methionine to Valeric. We further collected the blood samples from 16 family members of one proband and M233V polymorphism was found in 5 out 16 family members.</p><p><b>CONCLUSION</b>M233V is a novel polymorphism in the ATP-binding cassette transporter A1 gene and this AG genotype had family proneness.</p>

An experimental study on renal microvascular perfusion in dogs with acute cardiac insufficiency / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the changes and the effects of captopril on the renal blood flow and microvascular perfusion in dogs with acute cardiac insufficiency.</p><p><b>METHODS</b>Acute cardial insufficiency was induced by combining occlusion of the left anterior descending artery with right ventricular pacing in 12 mongrel dogs. The ascending aorta and left kidney were dissected and ultrasonic flow probes were placed on ascending aorta and renal artery to monitor cardiac output (CO) and renal blood flow (RBF). Contrast-enhanced ultrasound of the kidney was performed as CO was reduced to 25% (LCO25%) and 50% (LCO50%) from the basic measurement and microvascular flow velocity (beta), microvascular volume (A) and microvascular blood flow (renal cortex) were observed. After CO reduced to 50%, captopril 1 mg/kg and 2 mg/kg were injected successively and contrast-enhanced ultrasound of the kidney were performed again before and after injection.</p><p><b>RESULTS</b>At baseline, CO, RBF, CXbeta (beta of renal cortex), A and A x beta were (1.46 +/- 0.16) ml/min, (107.5 +/- 35.7) ml/min, 1.39 +/- 0.14, 120.3 +/- 14.8 and 167.4 +/- 25.0, respectively. After the LCO25% was reached, RAF, CXbeta, A and A x beta decreased to (72.50 +/- 32.4) ml/min, 0.87 +/- 0.082, 117.6 +/- 13.1, and 102.6 +/- 15.5, respectively. The corresponding values after the LCO50% was reached were (44.1 +/- 17.2) ml/min, 0.61 +/- 0.039, 106.9 +/- 12.0, and 64.7 +/- 8.83, respectively. It is suggested that the volume of the renal microvasculature remained stable until the LCO50% was reached. When captopril 1 mg/kg and 2 mg/kg were injected successively at LCO50%, MAP decreased from (85.4 +/- 7.8) mm Hg to (78.7 +/- 7.3) mm Hg and to (69.1 +/- 6.3) mm Hg (P < 0.05), respectively, while CO increased from 0.73 +/- 0.084 to 0.83 +/- 0.065 and to 0.9 +/- 0.054 (P < 0.05), respectively. RBF increased from (44.1 +/- 17.2) ml/min to 60.3 +/- 17.8 and to 79.4 +/- 17.8 (P < 0.05), respectively. After captopril 1 mg/kg and 2 mg/kg were injected, the increased flow ratios with CO were 0.15 +/- 0.084 and 0.31 +/- 0.011, respectively, and with RBF were 0.29 +/- 089 and 0.522 +/- 0.040, respectively. The increased renal blood flow ratio was higher than that of CO after captopril was used. The corresponding increases were from 0.61 +/- 0.039 to 0.75 +/- 0.020 and to 0.86 +/- 0.027 for CX beta, from 106.9 +/- 11.9 to 115.4 +/- 11.1 and to 116.6 +/- 8.9 for A, from 64.7 +/- 8.83 to 87.0 +/- 8.6 and to 100.6 +/- 8.9 for A x beta, respectively.</p><p><b>CONCLUSION</b>The renal microvasculature plays a role by keeping its volume stable in the protection against renal ischemia when acute cardiac output decreases slightly. The role of captopril to improve renal microvascular perfusion is independent of increased total cardiac output or increased systemic blood pressure.</p>