ObjectiveTo study the changes of levels of α subunits of stimulatory (Gsα) and inhibitory guanine nucleotide binding protein (Giα) in newborn guinea pig (0 2 days old) myocardium undergoing global ischemic reperfusion, and influences on the changes by St.Thomas Ⅱ and cold blood cardioplegic solution.MethodsThirty newborn guinea pigs were randomly assigned to three groups. GroupⅠ ( n = 10): the newborn hearts suffered by hypothermic global ischemia; group Ⅱ( n =10): the newborn hearts arrested by St. Thomas Ⅱ , and group Ⅲ ( n = 10): the newborn hearts arrested by cold blood cardioplegic solution. Levels of Gsα and Giα were investigated with Western blot analysis.ResultsNo differences of levels of Gsα and Giα were found in three groups before ischemia ( P gt;0.05). The level of Gsα after ischemia was significantly decreased than before ischemia in groupⅠand group Ⅱ ( P lt; 0 01), whereas no pronounced changes in group Ⅲ ( P gt;0.05) were noted after ischemia. The level of Gsα in group Ⅲ was not significantly changed after reperfusion compared with before ischemia( P gt;0 05), and it was much higher than those in groupⅠand group Ⅱ ( P lt; 0 01). Level of Giα was found not markedly changed in group Ⅲ after reperfusion compared with that before ischemia, but was notable higher in groupⅠand group Ⅱ( P lt;0.01). ConclusionsSignificant decrease of level of Gsα, whereas marked increase of level of Giα are found in myocardium of newborn guinea pig undergoing hypothermic (20℃) ischemic reperfusion. No impact of St. Thomas Ⅱ on these changes is verified, but recovery to the level of Gsα and Giα before ischemia is achieved by cold blood cardioplegic solution after ischemia and reperfusion. Unbalance between Gsα and Giα is the one of the mechanisms of ischemic reperfusion injury for immature myocardium.
ObjectiveTo investigate the protective effect and the regulation mechanism of oxaloacetate (OAA) on myocardial ischemia reperfusion injury in rats. MethodsSixty rats, weight ranged from 200 to 250 grams, were randomly divided into 6 groups:a negative control group, a sham operation control group, a model control group, an OAA pretreatment myocardial ischemia-reperfusion model group (three subgroups:15 mg/kg, 60 mg/kg, 240 mg/kg). We established the model of myocardial ischemia reperfusion of rats and recorded the internal pressure of left ventricle (LVSP), the maximal rate of left ventricular pressure change (±dp/dtmax) and left ventricular end diastolic pressure (LVEDP). We restored reperfusion 180 minutes after ligating the left anterior descending coronary artery 30 minutes and determinated cardiac troponin Ⅰ (cTn-I), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px). We took out heart tissues, stained it and calculated the infarcted size. We used the Western blot to detect the expression of NF-E2 related factor 2 (Nrf2), Kelch-like ECH-associated protein-1 (Keap1) and heme oxygenase-1 (HO-1). ResultsCompared with the sham operation group, heart function indexes in the negative control group had no significant difference (P>0.05). But in the model control group there was a decrease (P<0.05) And the serum levels of LDH, cTn-I, and myocardial infarcted size were significantly increased (P<0.01). Compared with the model control group, heart function indexes in the OAA pretreatment groups improved, the serum LDH, cTn-I activity, and infarct size decreased (P<0.05), SOD and GSH-Px activity increased (P<0.05). And these results were statistically different (P<0.01) in the high dose OAA pretreatment groups. Compared with the model control group, the expression of Keap1 in the OAA pretreatment group was down-regulated (P<0.001) while total Nrf2, nucleus Nrf2 and its downstream HO-1 was up-regulated (P<0.001), which suggested that OAA enhanced antioxidant capacity by (at least in part) Keap1-Nrf2 pathway, resulting in reducing myocardial damage and protecting myocardium after acute myocardial ischemia reperfusion injury. ConclusionOxaloacetate can provide protective effects on myocardial ischemia reperfusion injury through down-regulating the expression of Keap1 and up-regulating the expression of Nrf2 and its downstream peroxiredoxins to improve antioxidant capacity.
Objective To investigate the incidence and risk factors of non-alcoholic fatty liver disease (NAFLD) in patients with myocardial infarction. Methods A total of 634 patients with myocardial infarction from Beijing Anzhen Hospital were asked to take liver and gallbladder ultrasonography during hospitalization, and then divided into the NAFLD and non-NAFLD groups. The incidence and risk factors of the two groups were then analyzed. Results The incidence of NAFLD was 52.2% (331/634). Both body mass index (BMI) and serum alanine aminotransferase of the NAFLD group were higher than those of non-NAFLD group, with significant difference (Plt;0.05). The incidence of NAFLD was positively increased following the severity of coronary diseases (χ2=7.275, P=0.03). The result of multivariable logistic regression analysis showed BMI, multi-vessel lesions of coronary disease, and left main coronary artery lesion were the independent risk factors of NAFLD. Conclusion The myocardial infarction patients who are particularly complicated by overweight, multi-vessel lesions and left main coronary artery lesion have a higher incidence of NAFLD.
Objective To systematically review the effectiveness of amiodarone in treating repurfusion arrhythmia (RA) after thrombolytic therapy for acute myocardial infarction (AMI), so as to provide high quality evidence for formulating the rational thrombolytic therapy for AMI. Methods Randomized controlled trails (RCTs) on amiodarone in treating RA after thrombolytic therapy for AMI were electronically retrieved in PubMed, EMbase, The Cochrane Library (Issue 3, 2012), CBM, CNKI, VIP and WanFang Data from inception to January, 2013. According to the inclusion and exclusion criteria, two reviewers independently screened literature, extracted data, and assessed quality. Then RevMan 5.1 software was used for meta-analysis. Results A total of 5 RCTs involving 440 patients were included. The results of meta-analysis suggested that, compared with the blank control, amiodarone reduced the incidence of RA after thrombolytic therapy in treating AMI (RR=0.60, 95%CI 0.48 to 0.74, Plt;0.000 01) and the incidence of ventricular fibrillation (RR=0.47, 95%CI 0.26 to 0.85, P=0.01). It neither affected the recanalization rate of occluded arteries after thrombolytic therapy (RR=1.00, 95%CI 0.88 to 1.15, P=0.94) nor decreased the mortality after surgery (RR=0.33, 95%CI 0.10 to 1.09, P=0.07). Conclusion Current evidence indicated that, amiodarone can decrease the incidence of RA. Unfortunately, the mortality rate can’t be reduced by amiodarone. Due to the limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion
Objective To investigate the correlation between glycosylated hemoglobin A1c (HbA1c) and severity of coronary artery lesions in young men with acute myocardial infarction (AMI). Methods Total 278 young men with AMI less than 45 years old were retrospectively studied, and all of them were admitted to hospital from January 2009 to December 2011, and had undergone coronary angiography. According to the results of coronary angiography, the patients were divided into three groups based on the number of artery lesions: the single group (156 cases), the double group (64 cases) and the triple group (58 cases). The relationship between the severity of coronary artery lesions and the following factors were observed: HbA1c, systolic blood pressure (SBP), diastolic blood pressure (DBP), hemoglobin (Hb), serum uric acid (UA), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), body mass index (BMI), smoking history, drinking history and family history of early coronary artery disease. Results a) HbA1c levels were gradually raised in all the three groups, but the single group (6.39±1.67%) was significantly lower than the double group (6.91±1.63%) and the triple group (7.41±2.12%), with significant differences (Plt;0.05); the HbA1c level of the single group was significantly lower than the triple group in both the ST-segment elevation AMI (6.42±1.68% vs. 7.17±1.86%, Plt;0.05) and the non-ST-segment AMI (5.57±0.37% vs. 8.56±2.83%, Plt;0.05); the HbA1c level of the single group was significantly lower than the triple group in patients with diabetes millitus (8.31±1.83% vs. 8.59±2.02%, Plt;0.05) and in patients without diabetes millitus (5.56±0.33% vs. 5.74±0.37%, Plt;0.05); b) There were significant differences in SBP, TC, HDL-C, LDL-C and drinking history between the single group and the other two groups (all Plt;0.05), and there were significant differences in DBP and TG between the single group and the double group (all Plt;0.05); and c) The results of logistic regression analysis showed that, LDL-C (OR=1.790), HbA1c (OR=1.287) and SBP (OR=1.042) were the independent risk factors (all Plt;0.05) for multiple lesions in coronary arteries of young men with AMI. Conclusion Glycosylated hemoglobin A1c is an independent risk factor for multiple lesions in coronary arteries of young men with AMI.
Background Mortality and morbidity of acute myocardial infarction remains high. Intravenous magnesium started early after the onset of myocardial infarction is a promising adjunctive treatment that may limit infarct size, prevent serious arrhythmias, and reduce mortality. Several earlier trials and meta-analyses demonstrated a mortality rate reduction with magnesium treatment, but one mega trial found no benefit. Objective To examine the effect of intravenous magnesium versus control on early mortality and morbidity, stratified by time since onset of symptoms (lt;6 hours, 6+ hours), use of thrombolysis (used, not used), dose of magnesium used (lt;75 mmol, 75+ mmol). Search strategy We search the Cochrane controlled trial register (CCTR) of Cochrane Library, Medline and Embase. We also search Chinese Biomedical Disk (CBM disk) to identify the Chinese trials. Each database will be searched from its starting date to the first-half year of 2002. Selection criteria All randomized controlled trials that compared intravenous magnesium with placebo in the presence or absence of fibrolytic therapy in addition to routine treatment are eligible if they reported mortality and clinical events within 35 days of onset, regardless of language. Methods of review A data abstraction form will be specifically developed to extract information from the eligible articles. The quality assessment of RCT will be focused on method of treatment assignment, blinding of participants and investigators, control of selection bias after treatment assignment. The selection of studies, data extraction and assessment of methodological quality will be performed independently by two reviewers. Disagreements will be resolved through discussion, when necessary, in consultation with a third reviewer. Publication bias, heterogeneity and sensitivity analysis will be performed. The odds ratio (OR) will be used to pooling the effect if appropriate.