Junnan Wang

Friction and wear characteristics of hot-extruded leaded aluminum bearing alloys

The friction and wear characteristics of hot-extruded Al-Pb alloys with lead contents in the range 0–25 wt.% and as-cast Al-Pb alloys with lead content of 20 wt.% were investigated under dry-sliding conditions using a pin-on-disc test machine. It was found that hot extrusion greatly decreased the porosity that was caused by powerful stirring and considerably improved the mechanical properties of stircast Al-Pb alloys, including wear behavior. The coefficient of friction and wear rate decreased with increasing lead content, and especially the antiseizure property of hot-extruded Al-Pb alloys containing 20 wt.% and 25 wt.% lead were improved remarkably. Optical observation revealed that the reason for this was the formation of a black compact film of lubricant that covered almost the entire worn surface of specimens at a highly applied load level. This film is a mixture of different constituents containing Al, Fe, Si, O, and Pb.

The association of plasma miR-155 and VCAM-1 levels with coronary collateral circulation

AIMnInflammation plays an important role in development of coronary collateral circulation (CCC). The aim of this study is to determine whether the inflammation-related miRNA miR-155 and the inflammation marker VCAM-1 could be a biomarker for CCC.nnnPATIENTS & METHODSnWe measured levels of plasma VCAM-1 and miR-155 in patients with CCC according to Rentrop grade by ELISA or real-time polymerase chain reaction, respectively (n = 112).nnnRESULTSnPlasma miR-155 was negatively correlated with VCAM-1 in the poor CCC group and with Rentrop grade in all patients with CCC. In addition, plasma VCAM-1 was significantly decreased in CAD patients with CCC.nnnCONCLUSIONnPlasma miR-155 might be a potent independent predictor of collateral formation.

Reduced Plasma miR-146a Is a Predictor of Poor Coronary Collateral Circulation in Patients with Coronary Artery Disease

Coronary collateral circulation (CCC), an alternative blood supply for ischemic myocardium, improves survival rates among patients with coronary artery disease (CAD). However, there remains a lack of biomarkers to discriminate between patients with poor or good CCC. In this study, we aimed to observe the relationship between plasma microRNA-146a (miR-146a) levels and the coronary collateral circulation (CCC). Additionally, we aimed to explore whether the plasma miR-146a level could serve as a blood-based biomarker for CCC in patients with CAD. We measured the plasma levels of vascular endothelial growth factor A (VEGF-A) and miR-146a in patients with CCC by ELISA and real-time PCR, respectively, according to the Rentrop grades. The results showed that the plasma miR-146a level is significantly increased in CAD patients with good CCC and significantly decreased in those with poor CCC. In contrast, although VEGFA expression in patients followed a similar trend as the CCC, the differences between the groups were not statistically significant. There was a positive correlation between plasma miR-146a levels and the Rentrop grading. In addition, receiver operator characteristic analysis showed that miR-146a could be a potent biomarker for identifying patients with poor CCC.

Negative Association of Circulating MicroRNA-126 with High-sensitive C-reactive Protein and Vascular Cell Adhesion Molecule-1 in Patients with Coronary Artery Disease Following Percutaneous Coronary Intervention

Background:Percutaneous coronary intervention (PCI) causes endothelial damage, resulting in an inflammatory response with elevation of markers such as high-sensitive C-reactive protein (hs-CRP) and vascular cell adhesion molecule-1 (VCAM-1), which are associated with restenosis after PCI. Evidence suggests that microRNA-126 (miR-126) plays an important role in vascular inflammation, but its correlation with PCI-mediated inflammation has not been investigated. In this study, we investigated the effect of PCI on circulating miR-126 and inflammation markers such as hs-CRP and VCAM-1. Methods:We enrolled 130 patients with coronary artery disease (CAD) in the Second Hospital of Jilin University from October 2015 to December 2015. Among them, 82 patients with CAD, defined as at least one major epicardial vessel with >70% stenosis who planned to undergo PCI, were divided into acute coronary syndrome (ACS) group (46 patients) and stable angina (SA) group (36 patients). Forty-eight patients confirmed by coronary angiography without PCI were used as controls. The plasmas of all patients were collected prior to PCI and at 30 min, 24 h, and 72 h after PCI. The plasma VCAM-1 and hs-CRP were detected by enzyme-linked immunosorbent assay, and the miR-126 was evaluated by quantitative reverse transcription-polymerase chain reaction. Results:Plasma concentrations of hs-CRP and VCAM-1 in patients with either ACS (n = 46) or SA (n = 36) were significantly higher than in controls (n = 48) (P < 0.01) prior to PCI, and increased further at 24 h and 72 h after PCI, compared with prior PCI. Moreover, VCAM-1 was positively correlated with balloon time and pressure. In contrast, the plasma concentration of miR-126 was significantly lower in patients with CAD than in controls, and further decreased with time post-PCI. A negative correlation was observed between miR-126 and hs-CRP and VCAM-1 at 72 h after PCI. Conclusion:There was a negative correlation of miR-126 with the PCI-induced markers of inflammation such as hs-CRP and VCAM-1.

MicroRNA-210 Plays a Critical Role in the Angiogenic Effect of Isoprenaline on Human Umbilical Vein Endothelial Cells via Regulation of Noncoding RNAs.

Background:&bgr;-adrenoceptors play a crucial regulatory role in blood vessel endothelial cells. Isoprenaline (ISO, a &bgr;-adrenergic agonist) has been reported to promote angiogenesis through upregulation of vascular endothelial growth factor (VEGF) expression; however, the underlying mechanism remains to be investigated. It is widely accepted that certain noncoding RNAs, including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), can regulate endothelial cell behavior, including their involvement in angiogenesis. Therefore, we aimed to investigate whether noncoding RNAs participate in ISO-mediated angiogenesis using human umbilical vein endothelial cells (HUVECs). Methods:We evaluated VEGF-A messenger RNA (mRNA) and protein levels in ISO-treated HUVECs by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. To establish whether noncoding RNAs are associated with ISO-mediated angiogenesis, we measured expression of the miRNAs miR-210, miR-21, and miR-1, as well as that of the lncRNAs growth arrest-specific transcript 5 (GAS5), maternally expressed 3 (MEG3), and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in HUVECs exposed to ISO. Furthermore, to ascertain its importance in ISO-mediated angiogenesis, we constructed the HUVECs with overexpressing miR-210 and detected the subsequent expression of VEGF-A and noncoding RNAs. All statistical analyses were performed using SPSS 16.0 software. Intergroup comparisons were carried out by one-way analysis of variance. Results:VEGF-A mRNA levels were elevated in the ISO group (1.57 ± 0.09) compared to those in the control group (P < 0.01). Moreover, concentrations of VEGF-A in culture supernatants significantly differed between the control (113.00 ± 19.21 pg/ml) and ISO groups (287.00 ± 20.27 pg/ml; P < 0.01). Expression of miR-1, miR-21, and miR-210 was higher (3.89 ± 0.44, 2.87 ± 087, and 3.33 ± 1.31, respectively) in ISO-treated cells than that in controls (P < 0.01), whereas that of GAS5 and MEG3 (0.22 ± 0.10 and 0.58 ± 0.16, respectively) was lower as a result of ISO administration (P < 0.05). There was no significant difference in the expression of MALAT1 between the groups. Interestingly, miR-210 overexpression heightened the levels of VEGF-A and miR-21 (5.87 ± 1.24 and 2.74 ± 1.15, respectively; P < 0.01) and reduced those of GAS5 and MEG3 (0.19 ± 0.01 and 0.09 ± 0.05, respectively; P < 0.01). Conclusions:ISO-mediated angiogenesis was associated with altered expression of miR-210, miR-21, and the lncRNAs GAS5 and MEG3. The effects of miR-210 on the expression of VEGF-A and noncoding RNAs were similar to those of ISO, indicating that it might play an important role in ISO-mediated angiogenesis.

Differences in prevalence of hypertension and associated risk factors in urban and rural residents of the northeastern region of the People’s Republic of China: A cross-sectional study

Background Hypertension is a significant global public health problem and recognized as an important risk factor for cardiovascular diseases. This study was designed to assess the current prevalence of hypertension and to explore risk factors associated with hypertension by urban and rural status to guide the prevention and control of hypertension in Jilin province. Methods A multi-stage stratified random cluster sampling method was used to obtain data on hypertension, which was investigated by physical examination and face-to-face questionnaire in July 2014-December 2015. Sample data were analyzed by complex weighted statistical analysis to estimate blood pressure levels and prevalence of hypertension in the province. Multivariable logistic regression analysis was used to identify factors influencing hypertension rates. Results The prevalence of hypertension was significantly higher in rural areas than urban areas (25.93% versus 22.73%, respectively). The rates of hypertension known (46.7% versus 38.1%, respectively), control (13.7% versus 5.0%, respectively), and controlled among treated subjects (38.3% versus 17.5%, respectively) were higher in urban areas than in rural areas (all p < 0.001), while the treatment rate was not statistically significantly different between urban and rural areas (35.9% versus 28.4%, respectively). After adjusting for demographic covariates, hypertension prevalence in rural areas was still significantly greater than in urban areas (adjusted OR = 1.22; 95%CI: 1.10, 1.36; p < 0.001). Common risk factors for hypertension among urban and rural residents included older age; male; married; employed; less education; overweight/obese; greater abdominal waist circumference; family history of hypertension, stroke, or coronary heart disease; current smoker; alcohol consumption; higher visceral adiposity index; and higher body fat percentage. Conclusions This study identified an increased risk for hypertension in rural regions of Jilin province, suggesting that rural hypertension screening and treatment guidelines should receive greater attention.

Taurine Protects Primary Neonatal Cardiomyocytes Against Apoptosis Induced by Hydrogen Peroxide

The aim of this study was to investigate the effects of taurine (Tau) on primary cultured neonatal myocardial cells treated with hydrogen peroxide (H2O2) and the underlying mechanism. Primary cardiac myocytes from neonatal Wistar rats were pre-incubated with Tau, and its effects on cell viability and expression of CaM, CaMKII, p53, Bcl-2, and Bax were examined. Tau enhanced the viability of myocardial cells, decreased apoptosis, and alleviated the intracellular calcium overload, especially at dosages of 40 or 80 mM (P < 0.01 or P < 0.001, respectively). Moreover, Tau could inhibit the H2O2-induced decrease in CamKII and CaM expression at both the mRNA and protein levels. The pattern of CaMKII expression was consistent with that of the anti-apoptotic protein Bcl-2, but contrasted the pattern of the pro-apoptotic proteins p53 and Bax. Thus, our results show that Tau protects myocardial cells against damage caused by H2O2 exposure, suggesting that it might play a role in the mitochondrial apoptotic pathway by upregulating the expression of CaMKII to rescue myocardial cells. However, the underlying mechanism still needs to be investigated. In addition, we tested the protective effect of taurine on cardiac myocytes, and the effect of taurine on another model, specifically an animal model.

Differences in the treatment and control of hypertension in urban and rural residents of the northeastern region of the People’s Republic of China: a cross-sectional study

ABSTRACT Background: Hypertension is a significant global public health problem and an important risk factor for cardiovascular diseases. We aimed to determine treatment and control rates of hypertension and to explore related risk factors by urban and rural areas. Methods: A cross-sectional survey of 14,956 participants (≥ 15 years) was conducted in Jilin Province, China from July 2014 to December 2015 using questionnaire forms and physical measurements. Results: Total rates of hypertension treatment, control, and controlled blood pressure among treated subjects were 31.7%, 8.8%, and 27.9% in the Jilin Province. Rates of hypertension treatment, control, and controlled blood pressure among treated subjects were 35.9%, 13.7%, and 38.3% in urban areas and 28.4%, 5.0%, and 17.5% in rural areas, respectively. Higher treatment of hypertension was associated with older age, female sex, other races (except Han), and higher body fat percentage in both areas. Among urban residents, higher education was additionally associated with higher treatment of hypertension; among rural residents, a family history of coronary artery disease and unemployment were associated with higher treatment of hypertension. Higher control of hypertension was associated with unemployment, married status, higher education, healthy body mass index, lower abdominal waist circumference, non-smoking status, and lower visceral adiposity index in urban residents; higher control of hypertension was associated with younger age in rural residents. Conclusion: Treatment and control rates of hypertension in urban and rural areas were lower than the national average; blood pressure control in patients taking antihypertensive drugs needs further improvement.

Comparison of drug-eluting balloon versus drug-eluting stent for treatment of coronary artery disease: a meta-analysis of randomized controlled trials

BackgroundDrug-eluting balloons (DEB) have significant value for treating coronary artery disease (CAD). However, the merits of using DEB versus drug-eluting stents (DES) to treat CAD remain controversial. Herein, we conducted a meta-analysis to compare the safety and efficacy of DEB and DES for treatment of CAD.MethodsWe searched MEDLINE, EMBASE, and CENTRAL databases for eligible trials comparing DEB with DES for treatment of CAD. The primary endpoint was major adverse cardiac events (MACE); the secondary endpoints included in-lesion late lumen loss (LLL), binary restenosis (BR), myocardial infarction (MI), target lesion revascularization (TLR) and mortality.ResultsTwenty-three trials with a total of 2712 patients were included. There were no significant differences in the primary endpoint of MACE between the DEB and DES groups (Risk Ratio (RR) 1.19; 95% confidence interval (CI) (0.87, 1.63); Pu2009=u20090.27), or in the clinical outcomes of each of MACE’s components, including TLR, MI and mortality. However, efficacy was significantly different between the DEB and DES groups, especially when we compared DEB to second-generation DES: in-lesion LLL (Mean Difference (MD) 0.11; (0.01, 0.22); Pu2009=u20090.03); binary restenosis (RR 1.46; (1.00, 2.13); Pu2009=u20090.05).ConclusionsDEB is equivalent to DES in terms of safety for managing CAD, and DEB may be considered as an alternative choice for treatment of CAD.

The relationship of plasma decoy receptor 3 and coronary collateral circulation in patients with coronary artery disease.

Objective: Previously, decoy receptor 3 (DcR3) was found to be a potential angiogenetic factor, while the relationship of DcR3 with coronary collateral circulation formation has not been investigated. In this study, we aimed to investigate whether plasma decoy receptor 3 levels was associated with CCC formation and evaluate its predictive power for CCC status in patients with coronary artery disease. Methods: Among patients who underwent coronary angiography with coronary artery disease and had a stenosis of ≥ 90% were included in our study. Collateral degree was graded according to Rentrope Cohen classification. Patients with grade 2 or 3 collateral degree were enrolled in good CCC group and patients with grade 0 or 1 collateral degree were enrolled in poor CCC group. Results: Plasma DcR3 level was significantly higher in good CCC group (328.00 ± 230.82 vs 194.84 ± 130.63 ng/l, p < 0.01) and positively correlated with Rentrope grade (p < 0.01). In addition, plasma DcR3 was also positively correlated with VEGF‐A. Both ROC (receiver operating characteristic curve) and multinomial logistical regression analysis showed that plasma DcR3 displayed potent predictive power for CCC status. Conclusions: Higher plasma DcR3 level was related to better CCC formation and displayed potent predictive power for CCC status.