Ischemic postconditioning decreases matrix metalloproteinase-2 expression during ischemia-reperfusion of myocardium in a rabbit model: A preliminary report.

OBJECTIVE: To investigate the effect of ischemic postconditioning on the expression of matrix metalloproteinase (MMP)-2 during ischemia-reperfusion of myocardium in a rabbit model. METHODS: Thirty-six male New Zealand white rabbits were randomly divided into sham, ischemia-reperfusion and ischemic postconditioning groups. Myocardial ischemia-reperfusion was created by ligating the left anterior descending coronary artery for 30 min followed by 3 h of reperfusion. Myocardial infarction sizes were determined by dual staining with triphenyltetrazolium chloride and trypan blue. Plasma levels of MMP-2 were measured using ELISA. Myocardial MMP-2 messenger RNA was analyzed by reverse transcription polymerase chain reaction. RESULTS: The mean (± SD) infarct size in the ischemic postconditioning group was significantly smaller compared with the ischemia-reperfusion group (37.1±3.8% versus 57.5±1.9%; P=0.02). The incidence of ventricular tachycardia in the ischemic postconditioning group was also lower than in the ischemia-reperfusion group (8.5% versus 75%; P=0.003). MMP-2 messenger RNA expression in the ischemic postconditioning group was significantly lower compared with the ischemia-reperfusion group (0.4944±0.0476 versus 0.6989±0.0694; P=0.02). CONCLUSION: Ischemic postconditioning reduces myocardial ischemia-reperfusion injury, possibly by inhibiting the expression of MMP-2.

Impact of acute pulmonary embolism on plasma and tissue hepatocyte growth factor: an experimental study.

This study was designed to investigate the impact of acute pulmonary embolism (PE) on plasma and tissue hepatocyte growth factor (HGF). PE was established in 16 New Zealand white rabbits by intravenous injection of autologous blood clots. Another 16 sham-operated rabbits were used as control. Plasma HGF levels and tissue HGF expression was measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. The plasma HGF levels in the PE group were elevated 1 hour after PE (P < .01). In the lung tissue samples, the positive HGF expression ratio was 91.7% and 20.8%, respectively, in the PE and the control group (P < .01). The positive HGF expression ratio in the right ventricular tissue samples in the PE group was higher than in the control group (75.0% versus 20.9%; P < .01). The positive HGF expression ratio in the liver samples in the PE and the control groups was 33.3% and 16.7%, respectively (P < .05). In conclusion, acute PE was associated with a significant increase in plasma HGF. Acute PE was also associated with an enhanced HGF expression in the lungs, the right ventricle, and the liver.

Effect of primary percutaneous coronary intervention on serum collagen biomarkers following acute myocardial infarction.

OBJECTIVE: The aim of this study was to investigate the effect of primary percutaneous coronary intervention (PCI) on serum collagen biomarkers following acute myocardial infarction (AMI). METHODS AND RESULTS: Thirty-eight patients were enrolled into a primary PCI (n = 16) and a control (n = 22) group. The PCI group received successful PCI within 6 h of MI, whereas the control group received no PCI or thrombolytic therapy. Serum type I procollagen (PICP) and type III procollagen (PIIINP) were measured by enzyme-linked immunosorbent assay (ELISA). The baseline characteristics were similar between the PCI and control groups. There was no significant difference in left ventricular end-systolic, end-diastolic volume or ejection fraction between the two groups 30 min after MI (P > 0.05). A significant increase in PICP and PIIINP was noted in both groups 3 days after MI (P < 0.01). PICP and PIIINP in the PCI group declined overtime to the pre-PCI level, whereas they remained high in the control group. In the PCI group, the mean serum PICP and PIIINP on day 7, 14 and 30 was lower than in the control group (P < 0.01). CONCLUSIONS: AMI is associated with an increase in serum biomarkers of collagen synthesis. Early and successful PCI is associated with a reduction in serum collagen biomarkers.

Effects of xuezhikang on proliferation and adhesion capacity of cultured endothelial progenitor cells: An in vitro study.

BACKGROUND: Endothelial progenitor cells (EPCs) might be useful in the management of coronary artery disease (CAD). OBJECTIVE: The aim of this study was to investigate the effects of xuezhikang, an extract of Chinese red yeast rice, on the proliferation and adhesion capacity of EPCs from the peripheral blood of patients with stable CAD. METHODS: Mononuclear cells from 20 Chinese patients (14 men, 6 women; mean [SD] age, 64.5 [2.8] years [range, 60-69 years]) were isolated using densitygradient centrifugation. After 4 days in culture, the attached cells were treated with different concentrations of xuezhikang (50, 125, 250, and 500 ng/mL; 20 samples/group), atorvastatin (10 ng/mL; n = 20), or phosphate-buffered saline (control, n = 20) for 3 days. Cells that were positive for 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labeled acetylated low-density lipoprotein and lectin were defined as EPCs. They were counted by 2 independent investigators in ≥4 randomly selected highpower fields per well. EPCs were then treated and adherent cells were counted by the independent investigators who were blinded to study drug administration. RESULTS: The mean (SD) number of cultured EPCs in the xuezhikang 50-, 125-, 250-, and 500-ng/mL groups (205 [28], 244 [31], 283 [42], and 334 [43] cells, respectively; all, P < 0.001) was significantly increased in a dose-dependent manner compared with the control group (167 [36] cells). The adhesion capacity of the EPCs was significantly greater in the 4 xuezhikang groups (51 [9], 62 [10], 71 [11], and 83 [12] cells; all, P < 0.001) when compared with that of the control group (41 [7] cells). Both the number of EPCs (327 [49] cells) and the number of adhesive EPCs (84 [15] cells) in the atorvastatin group were also significantly increased compared with the control group (both, P < 0.001); however, these increases were not significantly different from those in the xuezhikang 500-ng/mL group. CONCLUSIONS: Xuezhikang was associated with significantly enhanced proliferation and adhesion capacity of EPCs derived from the peripheral blood of these patients with stable CAD. These effects were not significantly different between xuezhikang and atorvastatin.

Low magnitude of tensile stress represses the inflammatory response at intervertebral disc in rats.

OBJECTIVE: This study aims to determine if the involvement of tensile stress affects the expressions of inflammatory cytokines interleukin-17(IL-17), interleukin-1ß (IL-1ß), and inducible nitric oxide synthase (iNOS) at intervertebral discs in vivo. MATERIAL AND METHOD: Sixty-four female Sprague-Dawley rats were randomly divided into four groups: sham, tail-suspended (TS), tail-suspended with needle puncture (TSNP), and single-needle puncture (SNP) groups. A tail-suspension device provides low magnitude of tensile stress (2.45 Newton (N)), and aseptic needle puncture on the tail disc induces inflammatory response. After 4 weeks, the treated discs were harvested for histologic analysis, quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). RESULT: Pathological examination demonstrated that compared to the sham group, the morphologies of nucleus pulposus (NP) and anulus fibrosus (AF) in TS, SNP, and TSNP groups displayed degenerative changes in varying degrees. Results from RT-qPCR showed that IL-17 and iNOS mRNA expression levels were significantly higher in both TSNP and SNP groups than those in the sham groups. Expression of IL-17 and iNOS are not significantly different between the sham and TS groups (P > 0.05). Compared with the SNP group, the mRNA expression of IL-17 and iNOS in the TSNP groups were markedly decreased (P < 0.05). The regulation of IL-1ß and IL-17 detected by ELISA was coincident with the qRT-PCR results. CONCLUSION: The results from this study suggested that relatively low magnitude tensile stress might play an essential role in the anti-inflammatory process and the relief of low-back pain (LBP).

A new approach for transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty.

AIMS: To evaluate the safety and efficacy of a new approach for transseptal catheterization in patients undergoing percutaneous balloon mitral valvuloplasty (PBMV). METHODS: One hundred and two patients with rheumatic mitral stenosis were randomized into two groups. In the study group (RA approach), an imaginary horizontal line was drawn from the top end of the tricuspid valve under anteroposterior fluoroscopic view. The intersection of the horizontal line and the right edge of the corresponding thoracic vertebra was defined as the upper border of the Fossa ovalis. The atrial septum was punctured from a point 0.5 cm below the upper border of the Fossa ovalis. In the control group (LA approach), an imaginary horizontal line was drawn between the upper and middle third of the left atrium, and the intersection of this horizontal line and the right edge of the corresponding thoracic vertebra was used as an atrial septum puncture point. RESULTS: Atrial septum puncture succeeded in all patients in the study group and in 72.6% of the patients in the control group (p < 0.01). The average fluoroscopy times for transseptal catheterization in the study and the control groups were 2.0 +/- 0.5 and 3.0 +/- 1.0 min, respectively (p < 0.01). Transseptal catheterization was subsequently achieved using the RA approach in the 14 patients from the control group in whom the LA approach failed. CONCLUSIONS: The RA approach is a safe and effective means for transseptal catheterization in patients undergoing PBMV.