Protective Effects of MicroRNA-126 on Human Cardiac Microvascular Endothelial Cells Against Hypoxia/Reoxygenation-Induced Injury and Inflammatory Response by Activating PI3K/Akt/eNOS Signaling Pathway.

OBJECTIVE: This study explored the protective effects of the microRNA-126 (miR-126)-mediated PI3K/Akt/eNOS signaling pathway on human cardiac microvascular endothelial cells (HCMECs) against hypoxia/reoxygenation (H/R)-induced injury and the inflammatory response. METHODS: Untreated HCMECs were selected for the control group. After H/R treatment and cell transfection, the HCMECs were assigned to the H/R, miR-126 mimic, mimic-negative control (NC), miR-126 inhibitor, inhibitor-NC, wortmannin (an inhibitor of PI3K) and miR-126 mimic + wortmannin groups. Super oxide dismutase (SOD), nitric oxide (NO), vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) were measured utilizing commercial kits. Quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to detect miR-126 expression and the mRNA and protein expression of inflammatory factors. Western blotting was used to determine the expression of key members in the PI3K/Akt/eNOS signaling pathway. ACCK-8 assay and flow cytometry were employed to examine cell proliferation and apoptosis, respectively. The angiogenic ability in each group was detected by the lumen formation test. RESULTS: Compared to the control group, p/t-PI3K, p/t-Akt and p/t-eNOS expression, NO, VEGF and SOD levels, cell proliferation and in vitro lumen formation ability were decreased, while the ROS content, interleukin (IL)-6, IL-10 and tumor necrosis factor (TNF)-α expression and cell apoptosis were significantly increased in the H/R, mimic-NC, miR-126 inhibitor, inhibitor-NC, wortmannin and miR-126 mimic + wortmannin groups. Additionally, in comparison with the H/R group, the miR-126 mimic group had elevated p/t-PI3K, p/t-Akt and p/t-eNOS expression, increased NO, VEGF and SOD contents, and strengthened cell proliferation and lumen formation abilities but also exhibited decreased ROS content, reduced IL-6, IL-10 and TNF-α expressions, and weakened cell apoptosis, while the miR-126 inhibitor and wortmannin group exhibited the opposite results. Furthermore, decreased p/t-PI3K, p/t-Akt and p/t-eNOS expressions, decreased NO, VEGF and SOD contents, cell proliferation and lumen formation abilities, as well as increased ROS content, increased IL-6, IL-10 and TNF-α expression, and increased cell apoptosis were observed in the miR-126 mimic + wortmannin group compared to themiR-126 mimic group. CONCLUSIONS: These findings indicated that miR-126 protects HCMECs from H/R-induced injury and inflammatory response by activating the PI3K/Akt/ eNOS signaling pathway.

[Efficacy and safety of tirofiban use after successful percutaneous coronary intervention for patients with moderate to high risk non-ST segment elevation acute coronary syndromes].

OBJECTIVE: To evaluate the efficacy and safety of tirofiban use immediately after successful percutaneous coronary intervention (PCI) in patients with moderate to high risk non-ST segment elevation acute coronary syndromes (NSTE-ACS). METHODS: NSTE-ACS patients undergoing successful PCI (n = 246) were randomized by the envelope method to tirofiban group (n = 122, 10 µg/kg bolus within 3 min followed by 0.10-0.15 µg×kg(-1)×min(-1) for 36 h i.v.) or control group (n = 124, saline i.v. for 36 h). The primary efficacy composite end point was death, myocardial infarction, target vascular revascularization or ischemic stroke at 30 days. The second end point was the occurrence of composite end point at 7 days or 6 months. Key safety end points were bleeding and thrombocytopenia 3 days after PCI. RESULTS: Baseline characteristics were well-balanced between the two groups (P > 0.05). The primary end point occurred in 0.9% (1/117) patients in the tirofiban group and 3.3% (4/123) patients of those in the control group (P = 0.40). There was no significant difference in the composite end point at 7 days [0.8% (1/122) vs. 3.2% (4/124), P = 0.38] between the groups, however, there was a trend towards lower composite efficacy end points at 6 months in tirofiban group compared to control group [0.9% (1/117) vs. 5.9% (7/118), P = 0.07]. The probability of survival free of composite end point was significantly higher in the tirofiban group than that in the control group (99.2% vs. 94.2%, log-rank test, P = 0.03). There was no GUSTO severe or moderate bleeding or severe thrombocytopenia within 3 days post-PCI. There was no significant difference in mild bleeding [13.1% (16/122) vs. 7.3% (9/124), P = 0.13] or mild thrombocytopenia [0.8% (1/122) vs. 0.8% (1/124), P = 1.00] between the groups. CONCLUSION: Tirofiban use after successful PCI can improve 6-month event-free survival without increasing the risk of bleeding for patients with moderate to high risk NSTE-ACS.

[Angiotensin(1-7) attenuates left ventricular dysfunction and myocardial apoptosis on rat model of adriamycin-induced dilated cardiomyopathy].

OBJECTIVE: To investigate the effect of Angiotensin(1-7) [Ang(1-7)] on left ventricular dysfunction and myocardial apoptosis on rat model of adriamycin-induced dilated cardiomyopathy (ADR-DCM). METHODS: Weight-matched adult male Wistar rats were randomly divided into 3 groups: (1) the ADR-DCM group (n = 25), in which 2.5 mg/kg of ADR was weekly intravenously injected for 10 weeks. (2) Ang(1-7) group (n = 25), in which ADR rats were simultaneously treated with angiotensin-(1-7) (24 µg×kg(-1)×h(-1), ip.) for 12 weeks. (3) normal control group (n = 10). Hemodynamics and echocardiography examination were performed at 12 weeks. The malondialdehyde (MDA) was measured by TBA methods. The plasma concentration of AngII was determined by immunoradiometric assay. The pathological change was analyzed by histological hematoxylin-eosin staining. Myocardial apoptosis was assessed by TUNEL method. The protein expression of pro-apoptotic protein caspase-3, Bax and anti-apoptotic protein Bcl-xl in cardiomyocytes were detected by Western blot. RESULTS: Mortality was significantly lower in Ang(1-7) group than in ADR-DCM group (16% vs. 40%, P < 0.01). Compared to the control group, left ventricular end-diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD) and left ventricular end-diastolic pressure (LVEDP) were significantly increased in ADR-DCM group (all P < 0.01) while fractional shorting (FS), +dp/dtmax and -dp/dtmax were significantly reduced in ADR-DCM group (all P < 0.01). LVEDD, LVESD and LVEDP were significantly reduced while FS, +dp/dtmax and -dp/dtmax were significantly higher in Ang(1-7) group compared to the ADR-DCM group, but still higher than the control group (all P < 0.01). The concentrations of AngII and MDA were higher in the ADR-DCM group than in the control group (P < 0.01), which were significantly reduced by Ang(1-7) treatment (P < 0.01). The TUNEL-positive cells and apoptosis index, the expression of pro-apoptotic protein caspase-3 and Bax were significantly higher while the expression of anti-apoptotic protein Bcl-xl was significantly lower in the ADR-DCM group than in the control group (all P < 0.01) which could all be partially reversed by Ang(1-7) treatment (all P < 0.01). CONCLUSION: Ang(1-7) could significantly attenuate left ventricular dysfunction and myocardial apoptosis in this model by downregulating pro-apoptotic protein caspase-3 and Bax and upregulating anti-apoptotic protein Bcl-xl expression.

Fluorescent monitoring of the reaction kinetics of nonfluorescent molecules enabled by a fluorescent receptor.

A facile fluorescent method was developed to quantitatively monitor the hydrolysis kinetics of nonfluorescent esters by using a fluorecent endo-functionalized molecular tube and its recognition ability towards small polar molecules in water. It is possible to determine the apparent rate constants and study the structure-activity relationship.

[Effects of intracoronary autologous bone marrow mononuclear cells transplantation in patients with dilated cardiomyopathy].

OBJECTIVE: To evaluate the safety and efficacy of intracoronary autologous bone marrow mononuclear cells (BM-MNCs) transplantation in patients with dilated cardiomyopathy (DCM). METHODS: On top of standard therapy, DCM patients received BM-MNCs transplantation (n = 71) or saline injection (n = 187). The baseline clinical characteristics of two groups were comparable. Data on echocardiography, Holter, six-minute-walk test, cardiac SPECT and annual hospital days were obtained in all patients at baseline, 1, 3, 6, 12 and 24 months after transplantation. RESULTS: Six-minute-walk distance was significantly longer at one month [(345 +/- 76) m vs. (286 +/- 104) m, P < 0.05] and thereafter (all P < 0.05) in BM-MNCs group compared with saline group. Left ventri ocular ejection fraction (LVEF) at one month in BM-MNCs group was significantly higher compared with saline group [(41.5 +/- 9.4)% vs. (37.3 +/- 6.6)%, P < 0.05] and with pre-transplantation value [(41.5 +/- 9.4)% vs. (32.4 +/- 8.5)%, P < 0.05] while LVEF was similar at 24 months after transplantation between the two groups [(43.6 +/- 6.3)% vs. (43.2 +/- 6.0)%, P > 0.05]. Three months after transplantation, the number of ischemic segments of BM-MNCs group was significantly reduced compared with that of saline group (2.0 +/- 1.0 vs. 3.1 +/- 1.4, P < 0.05) and with baseline (2.0 +/- 1.0 vs. 3.1 +/- 1.2, P < 0.05) while the number of necrotic segments were similar in both groups during the follow-up. There were no significant difference in survival between two groups during 2 years follow-up (95.4% vs. 94.9%, P > 0.05) but the annual hospitalization days of BM-MNCs group was significantly lower than that of saline group [(23.6 +/- 13.4) d vs. (33.0 +/- 14.0) d, P > 0.05]. CONCLUSIONS: Intracoronary transplantation of autologous BM-MNCs was safe and could increase LVEF and the six-minute-walk distance and reduce hospitalization days for patients with dilated cardiomyopathy.

[Effects of tumor necrosis factor alpha on proteolysis of respiratory muscles in rats with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the impact of tumor necrosis factor alpha (TNF-alpha) on proteolysis of respiratory muscles in rats with chronic obstructive pulmonary disease (COPD). METHODS: Ninety healthy male adult Wistar rats were randomly divided into two groups: a normal control group (n = 20) and a model group (n = 70). The COPD rat model was established by intratracheal instillation of porcine pancreatic elastase and exposure to cigarette smoke for 60 days. Malnutrition was defined as the weight of the rats in the model group lower than 90% of the mean body weight of the control group. Two weeks after the establishment of the COPD model, 10 rats were randomly chosen in the malnutrition group, and received 4 days' therapy of intravenous injection of TNF-alpha monoclonal antibody (McAb) 0.1 mg/kg. The concentrations of TNF-alpha in the homogenates of respiratory muscles were measured by ELISA, and the contents of 3-methylhistidine, tyrosine in homogenates of respiratory muscle were measured by high performance liquid chromatography. RESULTS: The levels of TNF-alpha in the homogenates of diaphragmatic muscle of the malnutrition group [(125 +/- 11) pg/g] were significantly higher than that of the control group [(64 +/- 5) pg/g]; The levels of TNF-alpha in the homogenates of internal intercostal muscle of the malnutrition group [(119 +/- 11) pg/g] were significantly higher than that of the control group [(59 +/- 5) pg/g]. The contents of 3-methylhistidine in homogenates of diaphragmatic muscle [(7.1 +/- 0.6) nmol/g] and internal intercostal muscle [(7.4 +/- 0.6) nmol/g] of the malnutrition group were significantly higher than that of the control group [(4.0 +/- 0.5) nmol/g]. The contents of tyrosine in homogenates of diaphragmatic muscle [(639 +/- 24) nmol/g] and internal intercostal muscle [(660 +/- 25) nmol/g] of the malnutrition group were significantly higher than that of the control group [(579 +/- 26) nmol/g]. TNF-alpha in the respiratory muscle showed a strong positive correlation with proteolysis of respiratory muscle (r = 0.854, P < 0.01). CONCLUSION: An increase of proteolysis of respiratory muscles was found in COPD rats, more significant in the malnutrition rats. TNF-alpha is one of the causes for the increase of proteolysis of respiratory muscles.

Associations of P2Y12R gene polymorphisms with susceptibility to coronary heart disease and clinical efficacy of antiplatelet treatment with clopidogrel.

OBJECTIVE: To investigate the correlations of three P2Y12 receptor (P2Y12R) gene polymorphisms (rs7428575 T>G, rs2046934 C>T, and rs3732759 A>G) with susceptibility to coronary artery disease (CHD) and clinical efficacy of clopidogrel treatment for CHD. METHODS: From May 2014 to May 2015, 178 CHD patients (the case group) and 182 healthy controls (the control group) were selected from our hospital. The platelet-rich plasma (PRP) turbidimetry was used to measure the rate of adenosine diphosphate (ADP)-induced platelet aggregation before and after clopidogrel treatment. Clopidogrel-sensitive group was defined as a 10% or greater decrease in the rate of platelet aggregation after 10 days of clopidogrel treatment, while clopidogrel-resistant group was defined as a <10% decrease. Genotyping was performed by denaturing high-performance liquid chromatography (DHPLC). A haplotype analysis of P2Y12R gene polymorphisms was performed using SHEsis software. RESULTS: There were significant differences in genotype and allele frequencies of rs2046934 C>T and rs3732759 A>G between the case and control groups (all P<.05). Haplotypes GTA and TTA were negatively associated with CHD risk (both P<.05), but haplotype TCA was positively associated with CHD risk (P=.005). CHD patients in the clopidogrel-sensitive group had higher frequencies of TT genotype of rs2046934 C>T and lower frequencies of GG genotype of rs3732759 A>G than those in the clopidogrel-resistant group (both P<.05). CONCLUSIONS: P2Y12R gene rs2046934 C>T and rs3732759 A>G polymorphisms might be associated with the risk of CHD and the efficacy of clopidogrel treatment for CHD.

A mass vaccination campaign targeting adults and children to prevent typhoid fever in Hechi; expanding the use of Vi polysaccharide vaccine in southeast China: a cluster-randomized trial.

BACKGROUND: One of the goals of this study was to learn the coverage, safety and logistics of a mass vaccination campaign against typhoid fever in children and adults using locally produced typhoid Vi polysaccharide (PS) and group A meningococcal PS vaccines in southern China. METHODS: The vaccination campaign targeted 118,588 persons in Hechi, Guangxi Province, aged between 5 to 60 years, in 2003. The study area was divided into 107 geographic clusters, which were randomly allocated to receive one of the single-dose parenteral vaccines. All aspects regarding vaccination logistics, feasibility and safety were documented and systematically recorded. Results of the logistics, feasibility and safety are reported. RESULTS: The campaign lasted 5 weeks and the overall vaccination coverage was 78%. On average, the 30 vaccine teams gave immunizations on 23 days. Vaccine rates were higher in those aged < or = 15 years (90%) than in adolescents and young adults (70%). Planned mop-up activities increased the coverage by 17%. The overall vaccine wastage was 11%. The cold chain was maintained and documented. 66 individuals reported of adverse events out of all vaccinees, where fever (21%), malaise (19%) and local redness (19%) were the major symptoms; no life-threatening event occurred. Three needle-sharp events were reported. CONCLUSION: The mass immunization proved feasible and safe, and vaccine coverage was high. Emphasis should be placed on: injection safety measures, community involvement and incorporation of mop-up strategies into any vaccination campaign. School-based and all-age Vi mass immunizations programs are potentially important public health strategies for prevention of typhoid fever in high-risk populations in southern China.

[Dynamic responses of human body and human surrogate to different impacts under 30 degrees supine position].

OBJECTIVE: To study the difference between the dynamic responses of human body and human surrogate under 30 degrees supine position, and to discuss impact probability of substituting human body with human surrogate in impact tests. METHOD: Five volunteers experienced half-sine impact pulses, averaged 4.76, 8.96, 11.33 G, lasting for 40-60 ms on an impact tower. The human surrogate was exposed to half-sine impact pulses, averaged 6.77, 10.39, 16.93, 21.11, 24.98, 31.11 G, lasting for 40-60 ms, two times for each G level. ECG changes of the volunteers were continuously monitored before, during and after each impact. RESULT: Output responses at forehead and chest of human body and human surrogate increased with input increments. But there was obvious difference of the dynamic responses between human body and the surrogate to impact of low G levels. Heart rate of each volunteer had temporary increase during the process of impact, and returned to normal level soon after the impact. CONCLUSION: There is difference in a certain extend between the dynamic responses of human body and human surrogate. The ECG changes are induced mainly by mental stress during process of impact.

Effects of integrin alpha IIb(R995A) mutation on receptor affinity and pp125 (FAK) phosphorylation.

OBJECTIVE: To investigate the role of cytoplasmic domain of integrin alpha IIb in platelet signal transduction. METHODS: Binding capacity of integrin alpha IIb(R995A) to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting. RESULTS: Without activation, wild-type alpha IIb beta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha IIb(R995A)beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alpha IIb beta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions. CONCLUSION: The mutation in integrin alpha IIb(R995A) alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.

[Impact of simulated microgravity on the expression and distribution of cardiac gap junction protein CX43].

OBJECTIVE: To observe the expression and distribution changes of connexin 43 (CX) in rats' myocardium after simulated microgravity and explore the partial mechanism of arrhythmia. METHOD: Male Wistar rats were randomly assigned to either tail-suspension group (SUS) or control group (CON). Immunohistochemistry and Western Blot were used to detect the expression and the distribution of CX43. Electromicroscope was used to observe the ultrastructural changes. RESULT: In SUS group, the decrease of CX43 and the distribution disturbance were obvious (P<0.05), the proportion of the side-to-side gap junction increased (P<0.05), and space between some gap junctions disappeared. CONCLUSION: The results show that CX43 decreased significantly and distributed irregularly after simulated microgravity. These can cause the changes of cardiac electric conduction velocity and direction. As a result, conduction block and reentry may occur. And these might be the partial mechanism of cardiac arrhythmia.

[Effect of invasive and non-invasive positive pressure ventilation on plasma brain natriuretic peptide in patients with chronic obstructive pulmonary disease and severe respiratory failure].

OBJECTIVE: To investigate the change in plasma brain natriuretic peptide (BNP) in patients with chronic obstructive pulmonary disease (COPD) and severe respiratory failure receiving invasive or non-invasive positive pressure ventilation. METHODS: Fifty-six patients with COPD and severe respiratory failure were randomized into non-invasive ventilation group (n=28) to receive facial mask ventilation and invasive ventilation group (n=28) to have mechanical ventilation by tracheal intubation or tracheal incision. The changes of blood gas and BNP before and 24 h after the ventilation were observed. RESULTS: The indexes of blood gas analysis such as pH, PO2 and PaCO2 in the invasive ventilation group were better than those in the non-invasive ventilation group (P<0.05). The plasma levels of BNP of the invasive ventilation group were much lower 24 h after the treatment than that of the non-invasive ventilation group (P<0.05). CONCLUSION: Invasive ventilation produces better effect than non-invasive ventilation in the treatment of COPD with severe respiratory failure. Plasma concentrations of BNP has significant clinical value to evaluate the effect of mechanical ventilation.

[Evaluation on the safety of a group A + C meningococcal polysaccharide vaccine].

OBJECTIVE: To evaluate the safety of a group A + C meningococcal polysaccharide vaccine as part of a phase IV clinical trial. METHODS: The study area was divided into 108 clusters according to the principle of cluster randomization, stratified and paired sampling methods. 54 out of 108 clusters served as observation groups were administered A + C vaccine, while the rest 54 groups were administered Vi polysaccharide vaccine. An adverse event surveillance system was established to monitor the adverse events following the vaccination campaign. Identical form and methods were used for data collection to investigate the adverse events following the vaccination of both A+ C vaccine and Vi vaccine. RESULTS: 34,543 people were vaccinated, including 18,167 of whom received A + C vaccine, while the other 16,376 received Vi vaccine. The rates of immediate injection reaction and unsolicited non-serious adverse events from A + C vaccine group were 0.44% and 0.38% while of Vi vaccine group were 0.79% and 0.73% respectively. At the solicited adverse event survey on 3-day-post-vaccination, 1239 vaccinees were followed-up including 771 received A + C vaccine and 468 received Vi vaccine. The local injection reaction rate of A + C vaccine group on the 1st day was significantly higher (X2 = 13.98, P = 0.0002) than that of Vi vaccine group. Neither the local injection reaction rate nor the system reaction rate between both groups was significantly different on 2nd and 3rd day, post vaccination. It was not statistically different when comparing fever onset rate between those who received vaccine and those who did not, in each vaccine group. There were no serious adverse events observed. CONCLUSION: Results showed that the side effects of A + C vaccine and the Vi vaccine were mild and safe for vaccination campaigns targeting on populations at different age.

[Application of cluster randomization method on typhoid Vi vaccine trails].

OBJECTIVE: To describe the design and application of cluster randomized controlled method on typhoid Vi vaccine trial, and to assess the effect of implementation. METHODS: Simple size calculation of cluster-randomized trial was used to determine the sample size of the two groups and a vaccination campaign was conducted. The study group was given typhoid Vi vaccine and the control group was given meningococcal A vaccine. RESULTS: According to sample size calculation, a total sample of 96,121 participants was required and the study areas were divided into 108 clusters. In practice, 53 study clusters with 44,054 participants and 54 control clusters with 48,422 participants were stratified and matched according to size, location (urban or rural), characteristics (school, department, factory, demography) were randomized respectively. Confounding factors of two groups including age, sex, resident area, income, level of education were compared. It was found that the ratio of all confounding factors between the two groups were comparable and balanced. CONCLUSION: Confounding factors can be better controlled between study group and the control group by applying cluster-randomized method on vaccine trail which enabled the intervention to be more scientifically evaluated; The implementation of cluster randomization trial was simple and easy to be accepted.