Objective To study the effects of ischemia postconditioning(IPC) in reducing ischemia-reperfusion injury(IRI) in acute limp ischemia(ALI) and investigate the mechanism.Methods 45 New Zealand rabbits were treated with the method that combined high lipid diets and femoral intima injury by balloon inflation to build up limp atherosclerotic stenosis model,then they were randomly divided into three groups( each group 15 rabbits):control group;IR group and IPC group.Serum creatine phosphate kinase(CK),malondialehyde(MDA),superoxide dismutase (SOD) in three groups were measured before occlusion and 2 hours after sustaining reperfusion.The histological changes of limp skeletal muscle of experimental rabbits were analyzed and TUNEL method was used to access apoptosis of skeletal muscle cells.Results The levels of CK,M DA in IPC group were lower than IR group [ (7.49 ± 0.84)vs (8.19 ± 1.06),P＜0.05],[ (3.67 ±0.36) vs (4.06 ±0.55),P ＜0.05] while SOD level was higher than IR group [ (420.40 ± 30.94 ) vs ( 384.73 ± 44.12),P ＜ 0.05 ] ; The injury of skeletal muscles in I PC group was lighter than IR group and the apoptosis index of skeletal muscle cells was significantly decreased compared with that in IR group[(12.27+2.11)％ vs (16.62 ± 1.44)％,P＜0.01].Conclusion Applying IPC in acute limp ischemia could alleviate IRI and protect skeletal muscles.The mechanism was associated with oxidation resistance enhancing and the effects in reducing apoptosis of skeletal muscles induced by IRI.

Objective To investigate the predictive value of serum aldosterone and Plasminogen activator inhibitor-1 ( PAI-1 ) levels to the severity of coronary artery lesions and the recent prognosis in acute coronary syndrome (ACS) patients underwent percutaneous coronary intervention(PCI). Methods The study included 160 consecutive patients admitted. All the patients received coronary angiography and were divided into two groups:control group and ACS group. The patients' blood samples were abtained at the root of aortic artery to measure the serum aldosterone and PAI-1 levels. We analyzed their relationship with the severity of coronary artery lesions. The patients were also divided into three groups( high-score group, moderate-score group,low-score group)according to Gensini accumulated points,we analyzed the difference of aldosterone and PAI-1 levels in three groups. The predictive values of aldosterone and PAI-1 to the recent pronosis of ACS patients underwent PCIwere assessed. Results ( 1 )The patients' serum aldosteeone and PAI-1 levels in ACS group were significantly higher than control group( all P <0. 05 ) ;(2)The aldosterone and PAI-1 levels in high-score group were higher than moderate-score group, and moderate-score group was higher than low-score group. (3)The serum aldosterone level in ACS patients was positively correlated with the PAI-1 level ( r = 0.213, all P < 0. 05 ). ( 4 ) Multiple factor Logistic regression analysis indicated that aldosterone, PAI-1 levels were srtong independent predictors for the recent prognosis of ACS patients underwent PCI. Conclusion The aldosterone ,PAI-1 levels in ACS patients were correlated with the severity of coronary artery lesions. Both of them were strong predictors for the recent prognosis of ACS patients underwent PCI.

Objective To investigate relationship of microalbuminuria (MAU) and insulin resistance (IR) to severity of coronary lesions in patients with acute coronary syndrome (ACS), and its predictive value for short-term prognosis in then.Methods In total, 162 ACS patients admitted to the department of cardiology, Guangzhou First People's Hospital, Guangzhou, Guangdong province during January 2008 to June 2009 were selected and divided into three groups according to their urine albumin excretion rate (UAER): 54 cases in normal group with UAER less than 20 μg/min, 62 cases in microalbuminuria group with UAER of (20-200)μg/min, and 46 cases in mass-albuminuria group with UAER more than 200 μg/min.Difference in IR (by homeostasis model assessment, HOMA ) and severity of coronary lesions among the three groups was assessed.Effects of baseline MAU and IR on main adverse cardiac events within the recent six months were observed in ACS patients after percutaneous coronary intervention (PCI).Results IR increased and coronary lesions aggravated as UAER increasing in all the three groups of ACS patients (P＜0.05 or P＜0.01).MAU associated with IR, with a coefficient of correlation of 0.366 (P＜0.01).Results of multivariate logistic regression analysis showed that both MAU and IR were strong independent predictors for main adverse cardiac events in ACS patients within six months after PCI.Conclusions MAU and IR associate with severity of coronary lesions in ACS patients, suggesting certain predictive value for main adverse cardiac events in short-term after PCI.

Objective To investigate the association of insulin resistance (IR),blood pressure variability (BPV) and the severity of acute coronary syndrome (ACS),and assess the effect of percutaneous coronary intervention (PCI) on recent prognosis.Methods A total of 260 patients diagnosed as ACS and hospitalized in our department of cardiology from December 2009 to December 2010 were enrolled in the study.There were 93 cases of unstable angina pectoris ( UAP),84 of non ST segment elevation myocardial infarction and 83 of unstable angina pectoris.The subjects were divided into two groups according to 24 hour systolic blood pressure coefficient of variability (24 h SBP-CV) levels:high-CV group (24 h SBP-CV ＞11.5,n =130) and low-CV group(24 h SBP-CV ＜ 11.5,n =130).The differences in HOMA-IR and the severity of coronary artery diseases between the two groups were compared.The association of major adverse cardiac events within 6 months after PCI treatment,and IR as well as BPV was analyzed.Results Compared with the low-CV group,ACS patients in the high-CV group had obviously higher HOMA-IR levels (5.7 ± 1.2 vs 4.0 ± 1.4,P ＜0.01 ),more multivessel diseases (49.2％ vs 33.3％,P ＜0.05) and B2/C type coronary diseases (48.5％ vs 27.7％,P ＜0.01 ),and higher coronary Gensini scores (59.7 ± 17.5vs 43.8 ± 18.6,P ＜ 0.01 ).Multi-factors logistic regression analysis indicated that both 24 h BPV-CV and IR were independent predictors for MACE incidence within 6 months after undergone PCI ( P ＜ 0.05 or P ＜0.01 ).Conclusions IR and BPV were obviously associated with the severity of coronary artery diseases in ACS patients.IR and 24 h BPV-CV were valuable in predicting recent prognosis of ACS patients.

Objective To investigate the effects and the mechanism of tirofiban administration in myocardial ischemical reperfusion injury(MIRI) in patients with acute myocardial infarction(AMI) undergoing primary percutaneous coronary intervention(PCI). Method The study included 158 STEMI Patients who accepted primary PCI therapy and were randomly (random number) divided into two groups: tirofiban administration group and control group. Incidence of MIRI during PCI, Correct TIMI frame count(CTFC), ST segment resolution(STR), peak value and peak time of MB isoenzyme of creatine kinase( CK-MB), and incidence of major adverse cardiac events (MACE) during 30 days postoperation in both groups were measured. Results Tirofiban administration group was superior to control group in terms of incidence of MIRI, CTFC, STR, peak value and peak time of CK-MB, and incidence of MACE during 30 days postoperation (P < 0.05). Multiple factor logistic regression analysis indicated that intravenous tirofiban administration before primary PCI was the independently protective factor for MIRI. Conclusions Intravenous tirofiban administration in patients with STEMI before primary PCI can significantly decrease the incidence of MIRI,reduce myocardial damage and improve the prognosis.

Objective To investigate the effect of stress-induced hyperglycemia (SHG) on myocardial perfusion and clinical prognosis in elderly patients with acute myocardial infarction (AMI) who underwent primary percutaneous coronary intervention (PCI).Methods 348 elderly patients with first-time occurrence of acute ST-elevation myocardial infarction (STEMI) who underwent primary PCI within 12 hours from June 2008 to June 2010 were enrolled and followed up.All patients were divided into three groups according to serum glucose (SG) on admission:normal group (SG＜ 7.0 mmol/L,n=112);SG elevation group (7.0 mmol/L≤SG≤11.1 mmol/L,n=128) and (steady high blood glucose) SHG group (SG＞11.1 mmol/L,n=108).Myocardial perfusion indexes,including ST segment resolution (STR),TIMI myocardial perfusion grade (TMPG),peak value of creatine kinase CK-MB,left ventricular ejection (LVEF),and major adverse cardiac events (MACE) of patients in three groups,were measured and compared after emergency PCI.Results The blood glucose levels were increased,ST-elevation 2 h after PCI were well declined,the percentages of patients with TMPG 2-3 were decreased and peak values of CK-MB were increased in the three groups (all P＜0.01).After 12 months of follow-up,Kaplan-Meier survival analysis showed that patients of three groups had significantly different cumulative non-events survival rates [89.3％ (100/112) vs.85.9％ (110/128),76.3％ (83/108),P＜0.05].Multivariate Cox regression analysis showed that steady high blood glucose were the independent predictor for the occurrence of MACE in patients undergoing PCI after adjusting for age and gender,and the risk of MACE was increased by 5.811 folds in SHG group as compared with normal group (P＜0.01).Conclusions Stress induced hyperglycemia in elderly patients with STEMI can decrease myocardial perfusion level after primary PCI,which will lead to high incidence of MACE.

Objective To investigate the relationship between circulating microRNA-21 (miR-21 ) and unstable plague in patients with coronary artery disease (CAD).Methods A total of 100 consecutive patients with CAD admitted in the department of cardiology in Guangzhou first people’s hospital from January 2012 to December 2014 were enrolled.All patients were checked with coronary angiograph and intravascular ultrasound (IVUS)and were divided into two groups according to the presence of unstable plague detected by IVUS:stable plague group (n =45)and unstable plague group (n =55).Another 50 healthy people asking for routine physical examination during the same periods were enrolled as control group.Plasma miRNA-21 of patients were measured by the methods of quantitative realtime fluorescent Polymerase Chain Reaction (qRT-PCR).Results The levels of plasma miRNA-21 in patients of unstable plague group were significant higher than that in patients of stable plague group and control group (0.87 ±0.10)vs.(0.78 ±0.11)vs.(0.67 ±0.08),P <0.05.The receiver operation curve (ROC)showed that plasma miRNA-21 had great significance in assessing the CAD patients with unstable plague evidenced by the areas under the ROC curve to be 0.869 (95%CI:0.797 -0.940,P <0.05).Multivariate logistic regression analysis showed that plasma miRNA-21 was one strong independent predicative factor for unstable plague in patients with CAD (P <0.05 ).Conclusions The increasing levels of plasma miRNA-21 had the capabilitiy to predicate the unstable coronary plague in CAD patients.That miRNA-21 may be one valuable biomarker for predicating unstable plague in patients with CAD.

Objective To investigate the relationship between cytochrome P450 (CYP) 2C19 genetic polymorphism and clopidogrel resistance (CR) in patients with acute coronary syndrome(ACS),and to assess the effects of genetic polymorphism at CYP2C19 (681G ＞ A) on the prognosis of ACS patients.Methods A total of 462 patients with ACS were enrolled and received loading dose clopidogrel(600 mg).The blood samples of patients were collected before and 24 hours after taking loading dose clopidogrel,then 5 μmol/L ADP-induced platelet aggregation ratio(PAR) was examined.Difference of two PAR ≤ 10％ was defined as CR.Genomic DNA of patients were extracted from whole blood samples according to standard protocols and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to genotype the single nucleotide polymorphism of the CYP2C19 681G ＞ A.According to whether the gene CYP2C19 681A was carried,patients were divided into two groups:wild type group and non-wild type group.After PCI treatment,patients were followed up for 6 months and major cardiac adverse events (MACE) happened during follow-up periods were recorded.Results Totally 127 enrolled cases were finally defined as CR(27.5％),the frequency of CYP2C19 681A in patients with CR was higher than that in patients without CR(46.9％ vs 28.1％,P ＜ 0.01).The ratio of CR in wild type group were lower than non-wide type group(17.4％ vs 36.1％,P ＜ 0.01).Binary logistic regression analysis indicated that gene CYP2C19 681A was a strong independent predictor for CR in patients with ACS(OR 3.642,P ＜ 0.05).After 6 months of follow-up,Kaplan-Meier survival analysis showed patients of wild type group and non-wild type group had significantly different cumulative non-events survival rates (94.8％ vs 89.6％,Log rank =4.296,P =0.038).Conclusions The genetic polymorphism of CYP2C19 was associated with CR in patients with ACS.The mutation of CYP2C19 gene increased the risk of MACE in ACS patients undergoing PCI treatments and affected the patients' prognosis.

Objective To investigate the predicting value of Notch1 levels expressed in peripheral blood mononuclear cell (PBMC) for coronary artery calcification.Methods 300 consecutive patients with coronary artery disease (CAD) who hospitalizing in the department of cardiology in Guangzhou first people's hospital from January 2016 to June 2017 were enrolled.All Patients received 320-slice multi-detector row computed tomography scanning and coronary artery calcium sore(CCS)were measured.Patients were divided into three groups:control group (CCS =0),Low CCS group (CCS ＜97.6) and high CCS group (CCS ≥97.6) according to the mean value of CCS (CCS =97.6).Notch1 expressed in PBMC,serum interlekin-6 (IL-6) and high sensitivity C reactive protein (hs-CRP)of patients were examined and compared among three groups.Results The levels of Notch1 in PBMC and serum IL-6,hs-CRP of patients in high CCS group were significant higher than the other two groups [Notch1:7.02 ± 0.86 vs 6.32 ± 0.78 vs 5.49 ± 0.71;IL-6:(133.66 ± 10.18) μg/L vs (127.49 ± 10.79) μg/L vs (111.62 ± 9.87) μg/L;hs-CRP:(3.98 ± 1.02) mg/L vs (3.11 ±0.95)mg/L vs (2.56 ±0.76)mg/L] (P ＜0.05).The Spearman correlation analysis showed that the levels of Notch1 in PBMC were positive correlated with the levels of serum IL-6 and hs-CRP in enrolled patients with coronary calcification (P ＜ 0.05).Multivariate logistic regression analysis showed that the levels of Notch1 in PBMC and serum IL-6 were two strong independent risk factors for severity of coronary calcification in patients with CAD (P ＜ 0.05).Conclusions Notch1 expression in PBMC of patients with CAD was valuable to predicate the severity of coronary calcification.That the Notch1 signal path regulating the inflammation conditions in patients may be one of the most important mechanisms in the formation and progress of coronary calcification.

Objective:To establish a classification model for rapid identification of hypervirulent subtype ST17 clones of Group B Streptococcus (GBS) using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS).Methods:In a retrospective study, 235 strains of GBS strains were selected from multiple centers in China during 2015-2018. For model generation,45 strains of ST17 and 50 strains of non-ST17 (20 ST19, 15 ST12 and 15 ST10 strains) were enrolled as the modeling group. The remaining 90 main ST strains (40 ST17, 16 ST10, 17 ST12 and 17 ST19) were served as validation group. 50 GBS strains classified as other minor ST subtypes were regarded as taxonomic groups. MS spectra were collected by Bruker mass spectrometry, and then loaded for model generation and verification, and screening of differential peptide peaks by genetic algorithm (GA) and model verification on ClinProTools 3.0 software.Results:The recognition rate for ST17-GA model were 99.4% with cross validation value of 96.9%. Among the ten differential peptide peaks for the classification model, the weights of both two main peptide peaks m/z 2 956 and m/z 5 912 were greater than 1, while the weights of the all other eight peptide peaks were less than 0.5. Model validation showed only one of the ST17 was misjudged as non-ST17 strain, resulting in diagnostic accuracy of 98.9%, sensitivity of 97.5% and specificity of 100%, positive predictive value of 100% and negative predictive value of 98.0%, respectively. For other sporadic STs, 42.0% (21/50) of them were misdiagnosed as ST17 subtype.Conclusion:A MALDI-TOF MS classification model for hypervirulent subtype of ST17 GBS strains has been successfully established with good diagnostic efficacy.