[Evaluation of left ventricular diastolic function using velocity vector imaging and quantitative tissue velocity imaging].

OBJECTIVE: To validate the efficacy of velocity vector imaging (VVI) and quantitative tissue velocity imaging (QTVI) for evaluating left ventricular diastolic function. METHODS: Fifty-one patients underwent left heart catheterization were included in this study. Mean of peak early diastolic velocity (Em), EF and the ratio of early (E) to late (A) mitral valve flow velocity (E/A) were measured by echocardiography and the ratio of E to Em (E/Em) was calculated. Left ventricular end diastolic pressure (LVEDP) was measured during catheterization examination. RESULTS: E/Em derived from VVI or QTVI was significantly correlated with LVEDP (r = 0.808, P < 0.01 and r = 0.692, P < 0.01, respectively) and the correlation coefficient between VVI and LVEDP was significantly higher than that between QTVI and LVEDP (Z = 2.246, P = 0.025). Em derived from VVI and QTVI also negatively correlated with LVEDP (r = -0.740, P < 0.01 and r = -0.567, P < 0.01) and the correlation coefficient between VVI and LVEDP was significantly higher than that between QTVI and LVEDP (Z = 2.595, P = 0.009). However, there was no correlation between E/A and LVEDP (r = 0.117, P = 0.415). CONCLUSION: E/Em and Em derived from VVI and QTVI are valuable parameters for evaluating LV diastolic function.

Construction of eukaryotic expression vector of thrombospondin-1 type I repeat sequence.

OBJECTIVE: To construct eukaryotic expression vector of thrombospondin-1 type I repeat sequences. METHODS: Thrombospondin-1 type I repeat sequence gene was amplified from human fetal lung tissue by reverse transcriptase-PCR (RT-PCR) to construct both recombinant clone vector and expression vector through coupling reaction, followed by transforming these vectors into E.coli DH5alpha. The positive clones were selected for verification by double enzyme digestion and sequence analysis. RESULT: The expected amplification product, thrombospondin-1 type I repeat gene sequence, was acquired by RT-PCR, which had a consistency up to 99% with the sequence from the GenBank. CONCLUSION: The eukaryotic expression vector PcDNA3.1(+)/TSP-1 type I repeat sequence was successfully constructed.

[Cloning of expression vector for VEGF121 and VEGF165 genes encoding human vascular endothelial growth factor].

OBJECTIVE: To clone and construct the expression vector for human vascular endothelial growth factor (VEGF) genes. METHODS: Total RNAs were extracted from human lung tissue of a 4-month-old fetus and subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) with the amplified products cloned into pMD18-T vector. Sequence analysis was performed before the amplified products were cloned into the expression plasmid pcDNA3.1-, the recombinant of which was verified by endonuclease digestion. RESULTS: After RT-PCR using a pair of primers (sense -21/7 bp and antisense 554/576 bp), two bands were identified. The band (487 bp) shorter in length was confirmed as VEGF121 (with the full length of VEGF121 being 444 bp) while the longer band (619 bp) was normal VEGF165 (with the full length of VEGF165 being 576 bp). Interestingly, another slightly longer VEGF165 nucleotide sequence was identified by sequencing analysis, which featured an unique 20 bp insertion precisely between exon 3 and exon 4 from the first ATG of human VEGF165 cDNA. The 20 bp insert was identified as the retaining intron 3 terminal nucleotides containing the splicing signal, which caused frame shift mutation in the reading frame and could probably give rise to a short polypeptides consisting of only 97 amino acid residuals due to the early appearance of stop code UAG in the middle of exon 4. CONCLUSION: We have successfully constructed the expression vector for VEGF121 and VEGF165 genes, and a new possible alternative splicing isoform of VEGF is identified in normal fetus whose molecular mechanism and physiological function needs further investigation.

Evaluation of myocardial viability with myocardial contrast echocardiography: a preliminary clinical study.

OBJECTIVE: To evaluate the efficacy of myocardial contrast echocardiography (MCE) in the assessment of myocardial viability, with positron emission tomography (PET) as the golden standard. METHODS: Eleven patients with anterior wall Q wave myocardial infarction were enrolled in this study, who received successful percutaneous transluminal coronary angioplasty (PTCA) 3 to 19 months prior to the examinations by PET and MCE that were completed within 2 d. RESULTS: MCE score for the segments of necrotic myocardium, viable myocardium and normal myocardium was mostly 0, 0.5 and 1 respectively, and there was a significant difference between the grades of MCE score in identifying myocardial viability. In terms of diagnosing myocardium survival, MCE result was closely correlated with that of PET (with the correlation index rp of 0.78). CONCLUSION: Myocardial perfusion evaluation can be effectively accomplished by MCE, which might serve as a new approach to assess myocardial viability in clinical practice.

[Evaluation of two arterial closure devices, Angioseal and Perclose, in coronary catheter interventions].

OBJECTIVE: To assess the efficacy and safety of two arterial closure devices, Angioseal and Perclose, in patients undergoing coronary angiography and invasive interventions. METHODS: From January 2001 to April 2011, 997 inpatients underwent coronary angiography and interventions with arterial closure using Perclose (486 cases) or Angioseal (511 cases). The time to ambulation and hemostasis, major vascular complications and deployment success rate with the two devices were compared. RESULTS: The time to hemostasis was significantly shorter in Angioseal group than in Perclose group (3∓0.9 min vs 10.8∓4.8 min, P<0.001), but the time to ambulation was comparable between the two groups (6.4∓1.2 h vs 6.3∓0.7 h, P>0.05). The incidences of vascular complications showed no significant differences between the two groups (4.5% vs 3.7%, P>0.05), and none of the cases in either group developed femoral artery thrombosis or low limb embolism following the procedures. The deployment success rate was comparable between the two groups (97.8% vss 98.6%, P>0.05), and deployment failure was associated mainly with mishandling and design defect of the devices. CONCLUSIONS: Angioseal and Perclose are both effective and safe for arterial closure with reduced hemostasis and ambulation time and low incidences of vascular complications. Angioseal appears to have better performance than Perclose in shortening the hemostasis time and is easier to handle.

Management of subacute myocardial infarction in a patient with left coronary artery originating from the right coronary artery.

OBJECTIVE: Although the majority of coronary artery anomalies are found incidentally and not clinically significant, the interarterial course between the major vessels of the aberrant artery may be responsible for syncope, angina, arrhythmias or sudden death. There are only a few case reports describing the origination of all the coronary arteries from a single ostium. This anomaly occurs in only 0.024%-0.044% of the population. Left coronary artery originating from the right coronary is a rare coronary abnormality. Here we report a case of acute myocardial infarction in a patient with anomalous left coronary artery originating from the right coronary artery, as was confirmed by computerized tomography angiogram, which showed that only one single coronary artery stem originating from the right sinus of Valsalva trifurcated into a right coronary artery, left circumflex artery and a hypoplastic left anterior descending artery. Subsequent percutaneous coronary intervention (PCI) procedures were performed successfully. PCI procedures should be carried out with great caution in such cases, and this condition should be managed as a left main lesion.

[Ultrasound-mediated microbubble cavitation enhances gene transduction in rat pulmonary endothelial cells partially by affecting membrane fluidity and cytoskeleton structure].

OBJECTIVE: To evaluate the effect of therapeutic ultrasound-induced microbubble's cavitation on plasmid gene transduction in rat pulmonary endothelial cells in relation to the changes of membrane fluidity and cytoskeleton structure. METHODS: Rat endothelial cells cultured in vitro were transfected with EGFP plasmid in the presence of protein microbubbles. During the transfection process, the cells were exposed to continuous 2 MHz ultrasonic irradiation for 30, 60, 90, 120 and 180 s (groups A, B, C, D and E, respectively) with the constant mechanical index (MI) of 1.0, or for 60 s with different mechanical index (MI) of 0.5, 0.75, 1.0, 1.5, and 1.8 (groups B1, B2, B3, B4 and B5, respectively). The changes of endothelial cytoskeletal structure and membrane fluidity were evaluated by immunofluorescence staining after the exposure. RESULTS: EGFP gene transduction increase obviously with prolonged echo irradiation and increased MI. The intensity of immunofluorescence staining, which represented endothelial membrane fluidity, was 0.173±0.013, 0.250±0.037, 0.364±0.022, 0.381±0.019, and 0.395±0.009 in groups A-E, as compared with 0.171±0.017, 0.255±0.026, 0.378±0.007, 0.382±0.009 and 0.397±0.008 in groups B1-B5, respectively. The recovery intensity of the immunofluorescence staining representing the changes in microtubulin of the cytoskeleton structure was 159.15±4.79, 188.23±6.20, 205.80±4.48, 208.99±8.34, and 213.70±5.09 in groups A-E, and was 176.84±3.10, 187.57±14.52, 206.41±11.66, 220.12±13.39 and 221.16±12.78 in groups B1-B5, respectively. The endothelial membrane fluidity and microtubule fluorescence recovery intensity increased remarkably compared with the baseline (P<0.01) within the MI range of 0.50-1.0 and the exposure time of 30-90 s, but underwent no further changes in response to prolonged exposure time (180 s) at the MI of 1.5 (P>0.05). No changes in microfilament fluorescence intensity were observed after exposure to different MI or irradiation time. CONCLUSION: Therapeutic ultrasound-mediated albumin microbubble cavitation allows enhances plasmid gene transduction without causing cytoskeleton damages. Increased endothelial membrane fluidity and changes in cytoskeleton structure, especially microtubulin, partially contribute to this enhancement.

[Correlation between cardiovascular risk factors and the severity of coronary artery lesions in female patients].

OBJECTIVE: To investigate the association of the traditional and newly emerged cardiovascular risk factors with the severity of coronary artery lesion in female patients with coronary artery disease (CAD). METHODS: This study involved 235 female in-patients undergoing coronary angiography, including 156 with confirmed coronary artery disease (CAD) and 76 non-CAD patients. Univariate and multivariate analysis of the cardiovascular risk factors and the severity of coronary artery lesion were carried out in these patients. RESULTS: Univariate analysis showed that in the CAD patients of different severities, increased number of compromised arteries and total Gensini scores for the lesions were associated with increased incidences of the such risk factors including hypertension, type 2 diabetes, high triglycerides, high total cholesterol, low high-density lipoprotein cholesterol (HDL-C) level, high low density lipoprotein cholesterol (LDL-C) level, high uric acid level and high fibrinogen level. Multivariate regression analysis showed that high LDL-C level was the most significant independent risk factor for CAD, followed by diabetes, triglycerides, high uric acid, low HDL-C, high blood pressure and age. CONCLUSIONS: Female CAD patients are exposed to multiple risk factors, among which high LDL-C level is the most significant independent risk factor, but the other risk factors, especially the newly emerged factor uric acid, should be given due attention in the patients.

[Plasma matrix metalloproteinases-2 and -9 levels are elevated in patients with acute coronary syndrome and coronary chronic total occlusion].

OBJECTIVE: 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). METHODS: 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). RESULTS: 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). CONCLUSION: 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.