Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was...Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion （I/R） injury.Methods Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo,while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation （H/R）.Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.Results Compared to those of the controls,I/R or H/R induced apoptosis of cardiomyocytes was significantly iucreased both in vivo （24.4％ ± 9.4％ vs.2.2％ ± 1.9％,P ＜ 0.01,n =5） and in vitro （14.12％ ±0.92％ vs.2.22％ ± 0.08％）.The expression of miR-15a and miR-15b,but not miR-16,was increased in the mice I/R model,and the results were consistent in the H/R model.Conclusions Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury,therefore,down-regulation of miR- 15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.展开更多
Objective There are still a high proportion of patients with ST-segment elevation myocardial infarction （STEMI） missing out early reperfusion even in the primary percutaneous coronary intervention （PCI） era. Most ...Objective There are still a high proportion of patients with ST-segment elevation myocardial infarction （STEMI） missing out early reperfusion even in the primary percutaneous coronary intervention （PCI） era. Most of them are stable latecomers, but the optimal time to undergo delayed PCI for stable ones remains controversial. Methods We investigated all STEMI patients who underwent delayed PCI （2-28 days after STEMI） during 2007-2010 in Beijing and excluded patients with hemodynamic instability. The primary outcome was maj or adverse cardiovascular events （MACEs）. Results This study finally enrolled 5,417 STEMI patients and assigned them into three groups according to individual delayed time （Early group, 55.9%; Medium group, 35.4%; Late group, 8.7%）. During 1-year follow-up, MACEs occurred in 319 patients. The incidence of MACEs were respectively 7.1%, 5.6% and 6.7% among three groups. The Medium group had less recurrent myocardial infarction plus cardiac death （hazard ratio, 0.525; 95% confidence interval, 0.294-0.938, P = 0.030） than Late group and less repeat revascularization （hazard ratio, 0.640; 95% confidence interval, 0.463-0.883, P = 0.007） than Early group in pairwise comparisons. We depicted the incidence of major adverse cardiovascular event （MACE） by delayed time as a quadratic curve and found the bottom appeared at day 14. Conclusions The delayed PCI time varied in the real-world practice, but undergoing operations on the second week after STEMI had greater survival benefit and less adverse events for whom without early reperfusion and hemodynamic instability.展开更多
Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acu...Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acute myocardial ischemia,we partially ligated the left anterior decending(LAD)coronary artery of canine hearts between lst.and 2nd.diagonal branches and then performed transmyocardial revascularization in this region with Ho-YAG laser.Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before,after ischemia and after laser revascularization.Pictures were taken with “R” wave trigger skill. Results.Acoustic density derterming in the ischemia region (anterior wall)with MCE(myocardial contrast echocardiography)was obviously decreased(540±181) after the LAD was ligated,as compared with before(1169±161, P<001).It was increased remarkably after transmyocardial laser revascularizatuon(TMLR)(112±201, P<001)as compared with that when ischemia and approximated to that before ischemia(P>005).There were no differences in acoustic density in the lateral wall(as control)among these comprehensive three periods(P>005).Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region. Conclusion.Acute ischemic myocardium can be perfused by oxygenated blood from the left ventricle through Ho-YAG laser channels.Evidence of blood perfusion through laser channels during systolic phase was detected,and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin rnay be regarded as a reliable method in the study of transmyocardial revascularization.展开更多
Objective To evaluate the efficacy and the mechanism of application of selective head cooling on neuronal morphological damage during postischemic reperfusion in a rabbit model.Methods 168 New Zealand rabbits were r...Objective To evaluate the efficacy and the mechanism of application of selective head cooling on neuronal morphological damage during postischemic reperfusion in a rabbit model.Methods 168 New Zealand rabbits were randomized into three groups. Group Ⅰ [n=24, (38±0.5)℃, non-ischemic control]; Group Ⅱ [n=72, (38±0.5)℃, normothermic reperfusion]; Group Ⅲ [n=72, (28±0.5)℃, selective head cooling, initiated at the beginning of reperfusion). Animals in three subgroups (n=24, each) of Group Ⅱ and Group Ⅲ had reperfused lasting for 30, 180 and 360 min respectively. Using computerized image analysis technique on morphological changes of nucleus, the degree of neuronal damage in 12 regions were differentiated into type A (normal), type B (mild damaged), type C (severely damaged) and type D (necrotic). Fourteen biochemical parameters in brain tissues were measured.[KH*2/5D]Results As compared with Group Ⅰ, the counts of type A neuron decreased progressively, and those of type B, C and D increased significantly in Group Ⅱ during reperfusion (P【0.01). In Group Ⅱ, vasoactive intestinal peptide, b-endorphine, prostacyclin, T 3 and Na +, K +-ATPase were correlated with the changes of type A; b-endorphine and thromboxane with type B; glucose and vasopressin with type C; Na +, K +-ATPase, glutamic acid, T 3 and vasoactive intestinal peptide with type D (P【0.05). As compared with Group Ⅱ, the counts of type A increased, and those of type C and D significantly decreased in Group Ⅲ (P【0.01). In Group Ⅲ, Ca 2+ , Mg 2+ -ATPase were correlated with the changes of type A, C and D (P【0.01). Conclusion Selective head cooling for sex hours during postischemic reperfusion does improve neuronal morphological outcomes in terms of morphological changes.展开更多
文摘Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion （I/R） injury.Methods Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo,while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation （H/R）.Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.Results Compared to those of the controls,I/R or H/R induced apoptosis of cardiomyocytes was significantly iucreased both in vivo （24.4％ ± 9.4％ vs.2.2％ ± 1.9％,P ＜ 0.01,n =5） and in vitro （14.12％ ±0.92％ vs.2.22％ ± 0.08％）.The expression of miR-15a and miR-15b,but not miR-16,was increased in the mice I/R model,and the results were consistent in the H/R model.Conclusions Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury,therefore,down-regulation of miR- 15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.
文摘Objective There are still a high proportion of patients with ST-segment elevation myocardial infarction （STEMI） missing out early reperfusion even in the primary percutaneous coronary intervention （PCI） era. Most of them are stable latecomers, but the optimal time to undergo delayed PCI for stable ones remains controversial. Methods We investigated all STEMI patients who underwent delayed PCI （2-28 days after STEMI） during 2007-2010 in Beijing and excluded patients with hemodynamic instability. The primary outcome was maj or adverse cardiovascular events （MACEs）. Results This study finally enrolled 5,417 STEMI patients and assigned them into three groups according to individual delayed time （Early group, 55.9%; Medium group, 35.4%; Late group, 8.7%）. During 1-year follow-up, MACEs occurred in 319 patients. The incidence of MACEs were respectively 7.1%, 5.6% and 6.7% among three groups. The Medium group had less recurrent myocardial infarction plus cardiac death （hazard ratio, 0.525; 95% confidence interval, 0.294-0.938, P = 0.030） than Late group and less repeat revascularization （hazard ratio, 0.640; 95% confidence interval, 0.463-0.883, P = 0.007） than Early group in pairwise comparisons. We depicted the incidence of major adverse cardiovascular event （MACE） by delayed time as a quadratic curve and found the bottom appeared at day 14. Conclusions The delayed PCI time varied in the real-world practice, but undergoing operations on the second week after STEMI had greater survival benefit and less adverse events for whom without early reperfusion and hemodynamic instability.
文摘Objective. To study the mechanism and effects of blood perfusion to the acute ischemic region of myocardium through Ho-YAG laser channels with myocardial contrast echocardiography. Methods. To produce the model of acute myocardial ischemia,we partially ligated the left anterior decending(LAD)coronary artery of canine hearts between lst.and 2nd.diagonal branches and then performed transmyocardial revascularization in this region with Ho-YAG laser.Myocardial contrast echocardiography was made with a new generation of ultrasound contrast agent and second harmonic imaging of this region before,after ischemia and after laser revascularization.Pictures were taken with “R” wave trigger skill. Results.Acoustic density derterming in the ischemia region (anterior wall)with MCE(myocardial contrast echocardiography)was obviously decreased(540±181) after the LAD was ligated,as compared with before(1169±161, P<001).It was increased remarkably after transmyocardial laser revascularizatuon(TMLR)(112±201, P<001)as compared with that when ischemia and approximated to that before ischemia(P>005).There were no differences in acoustic density in the lateral wall(as control)among these comprehensive three periods(P>005).Contrast in the laser region developed one cardiac cycle ahead of that in the non-ischemic normal region. Conclusion.Acute ischemic myocardium can be perfused by oxygenated blood from the left ventricle through Ho-YAG laser channels.Evidence of blood perfusion through laser channels during systolic phase was detected,and myocardial contrast ultrasonography using intravenous perfluorocarbon-exposed sonicated dextrose albumin rnay be regarded as a reliable method in the study of transmyocardial revascularization.
文摘Objective To evaluate the efficacy and the mechanism of application of selective head cooling on neuronal morphological damage during postischemic reperfusion in a rabbit model.Methods 168 New Zealand rabbits were randomized into three groups. Group Ⅰ [n=24, (38±0.5)℃, non-ischemic control]; Group Ⅱ [n=72, (38±0.5)℃, normothermic reperfusion]; Group Ⅲ [n=72, (28±0.5)℃, selective head cooling, initiated at the beginning of reperfusion). Animals in three subgroups (n=24, each) of Group Ⅱ and Group Ⅲ had reperfused lasting for 30, 180 and 360 min respectively. Using computerized image analysis technique on morphological changes of nucleus, the degree of neuronal damage in 12 regions were differentiated into type A (normal), type B (mild damaged), type C (severely damaged) and type D (necrotic). Fourteen biochemical parameters in brain tissues were measured.[KH*2/5D]Results As compared with Group Ⅰ, the counts of type A neuron decreased progressively, and those of type B, C and D increased significantly in Group Ⅱ during reperfusion (P【0.01). In Group Ⅱ, vasoactive intestinal peptide, b-endorphine, prostacyclin, T 3 and Na +, K +-ATPase were correlated with the changes of type A; b-endorphine and thromboxane with type B; glucose and vasopressin with type C; Na +, K +-ATPase, glutamic acid, T 3 and vasoactive intestinal peptide with type D (P【0.05). As compared with Group Ⅱ, the counts of type A increased, and those of type C and D significantly decreased in Group Ⅲ (P【0.01). In Group Ⅲ, Ca 2+ , Mg 2+ -ATPase were correlated with the changes of type A, C and D (P【0.01). Conclusion Selective head cooling for sex hours during postischemic reperfusion does improve neuronal morphological outcomes in terms of morphological changes.
