MiRNA-26a inhibits myocardial infarction-induced apoptosis by targeting PTEN via JAK/STAT pathways.

INTRODUCTION: Acute myocardial infarction (MI) is a common cause of the morbidity and mortality of cardiovascular diseases in the world. Acute MI lead to cardiovascular output after formation of myocardial ischemia and circulatory arrest in coronary heart diseases. However, the mechanisms underlying MI injury are poorly understood. We explored the part played by miR-26a in myocardial infarction (MI). MATERIAL AND METHODS: Decreased miR-26a expression in H2O2-treated newborn murine ventricular cardiomyocytes (NMVCs) was observed, as well as in the infarcted heart of MI mouse model, compared to untreated NMVCs and healthy mouse heart tissue, respectively. Conversely, the upregulation of phosphatase and tensin homolog (PTEN) was observed in H2O2-treated NMVCs, and in infarcted hearts. An MTT assay and BrdU staining showed that H2O2 treatment attenuated cell viability in NMVCs, whereas miR-26a overexpression increased cell viability. Both TUNEL assay and flow cytometry (FC) displayed that miR-26a expression suppressed H2O2-induced cell apoptosis. Besides, miR-26a overexpression suppressed the upregulation of PTEN expression in H2O2-treated NMVCs by directly binding to PTEN 3'-UTR. RESULTS: PI3K/Akt and JAK/STAT signal transduction pathways were found to be regulated through cross-talk between miR-26a and PTEN. Furthermore, agomiR-26a treatment in MI mouse model considerably suppressed the size of the infarcted regions, and improved cardiac activity. CONCLUSIONS: MiR-26a expression in MI cardiac tissues was downregulated in response to H2O2 stress, whereas it could still protect against cell death by modulation of the PI3K/Akt and JAK/STAT signal transduction pathways by directly targeting PTEN.

Treatment with verapamil for restoration of sinus rhythm in atrial fibrillation with rapid ventricular response: A case report.

RATIONALE: Atrial fibrillation (AF) is a common arrhythmia disease that can cause thromboembolic disease and/or heart failure, resulting in increased mortality. Propafenone, amiodarone, and flecainide are recommended for converting AF to sinus rhythm. Beta blockers, verapamil, diltiazem, and digoxin are recommended for controlling AF with fast ventricular rate (VR). In this case report, we found that verapamil successfully converted AF into sinus rhythm. PATIENT CONCERNS: A 92-year-old woman presented with fast VR AF with a history of coronary heart disease, hypertension, and diabetes. DIAGNOSES: Verapamil can successfully convert AF into sinus rhythm. INTERVENTIONS AND OUTCOMES: The patient was treated with amiodarone or propafenone, yet still had AF. After stopping amiodarone and propafenone, the patient was given verapamil to control the VR, and following 9 days of treatment the patient switched to sinus rhythm. When verapamil treatment was stopped, the patient experienced AF recurrence. Upon receiving verapamil again, the AF again converted into sinus rhythm. LESSONS: For the treatment of AF, nondihydropyridine calcium antagonists can be tried in the absence of antiarrhythmic drugs.

Associations between bone mineral density and subclinical atherosclerosis: a cross-sectional study of a Chinese population.

CONTEXT: The significance of associations between bone mineral density (BMD) and atherosclerosis in the Asian population is less clear. OBJECTIVE: The aim of this study was to explore the population-level associations between BMD and subclinical atherosclerosis. DESIGN AND SETTING: This was a community-based cross-sectional study conducted in Shenyang, China. PARTICIPANTS: A total of 385 Chinese women and men aged 37-87 years were studied. MAIN OUTCOME MEASURES: The BMD was measured at the total hip and lumbar spine using dual-energy x-ray absorptiometry. The ankle-brachial index (ABI), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT) were measured to assess atherosclerosis. Multiple regression analysis was applied to study the associations. Multicolinearity was examined using the variance inflation factor, condition index, and variance proportions. Factor analysis and principal component regression were used to remove the problem of multicolinearity. RESULTS: The differences of ABI, PWV, and CIMT among the normal BMD, osteopenia, and osteoporosis groups were not found. Total hip BMD was correlated with ABI in women after adjustment for age (r = 0.156). Sex-specific regression models included adjustment for age, body mass index, cigarette smoking, alcohol consumption, menopausal status (women), systolic blood pressure, diastolic blood pressure, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting blood glucose, serum uric acid, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and fibrinogen. Total hip BMD was associated with ABI in women after adjustment for age (per SD decrease in ABI: -0.130 g/cm(2), P = .022), but the association was borderline significant after full adjustment (P = .045). Total hip BMD and lumbar spine BMD were not associated with ABI, PWV, and CIMT after full adjustment in participants without a fracture history. The risk of osteoporosis was not associated with ABI, PWV, and CIMT. CONCLUSIONS: Low BMD is not associated with subclinical atherosclerosis as assessed by ABI, PWV, and CIMT.

Association of apolipoprotein A1 -75 G/A polymorphism with susceptibility to the development of acute lung injury after cardiopulmonary bypass surgery.

INTRODUCTION: Apolipoprotein A1 (apoA1) is the major apoprotein constituent of high density lipoprotein (HDL) which exerts innate protective effects in systemic inflammation. However, its role in the acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) has not been well studied. The objective of this study was to investigate the potential association between APOA1 -75 G/A polymorphism and the development of ALI after cardiopulmonary bypass (CPB) surgery. MATERIALS AND METHODS: A hospital-based case-control study was conducted in patients with ALI (n = 300), patients without ALI (n = 300) and healthy controls (n = 300). Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay was applied to assess the APOA1 -75 G/A genotypes. RESULTS: Patients with ALI had a significantly higher frequency of APOA1 -75 AA genotype [odds ratio (OR) =1.75, 95% confidence interval (CI) = 1.04, 2.92; P = 0.03] than patients without ALI. APOA1 -75 AA genotype (OR =3.47, 95% CI = 1.60, 7.52; P = 0.002) and A allele (OR =1.92, 95% CI = 1.24, 2.96; P = 0.003) were the significant independent prognostic factors for the 30-day survival rate of patients with ALI after CPB surgery. CONCLUSION: Our study suggested that APOA1 -75 AA genotype was associated with a higher ALI risk after CPB surgery. Patients with the APOA1 -75 AA genotype and A allele had higher 30-day mortality of ALI after CPB surgery. Additional studies are needed to confirm this finding.

[Finite element method and computational fluid dynamics used in the analysis of a stent].

Stent implantation can cause thrombus, vessel injury and blood flow disturbance which are considered as the main causes of instent restenosis. In order to investigate the influence of stent implantation on vessel wall and blood flow, we used finite element method (FEM) and computational fluid dynamics (CFD) in this work. The results showed that the implantation of the stent could cause vessel injury and flow stagnation. The instant recoil of the implanted stent is much more than that of the stent itself (12.3% versus 3.1%). In conclusion, FEM and CFD can help illustrate and quantify some biomechanical characteristics for the optimization of stent design.

[Hemodynamics analysis of intravascular stents with different design features].

Wall shear stress plays an important role in the development of in-stent restenosis. It has been demonstrated that low wall shear stress. is associated with neointimal hyperplasia. We used computational fluid dynamics (CFD) to investigate the steady and pulsatile flows in the vicinity of model stents and focused on the changes of wall shear stress caused by the implanted stents. The results showed that wall shear stress depended greatly on the size and structure of the stents, which would have implications for the optimization of intravascular

Analysis of the transient expansion behavior and design optimization of coronary stents by finite element method.

The percutaneous transluminal coronary angioplasty (PTCA) assisted with stenting technique has become a primary therapy to coronary heart disease. In practice, the structure conditions of both ends of stent/balloon system influence a stent's instantaneous expansion behavior. The transitory nonuniform expansion, the so-called dogboning, of stent/balloon system is one of the main reasons to induce the acute vascular injury at the two edges of a stent. This kind of vascular injury has a close relationship with the in-stent restenosis. In the present paper, the finite element method (FEM) was applied to simulate the transient expansion process of stent/balloon system with different stent structure and balloon length under the internal pressure. And two types of stent and six collocations of stent and balloon were modeled. Modeling results showed that the dogboning phenomenon can be eliminated by improving geometry of a stent or/and varying the length of balloon over stent. The above modeled results were further confirmed by following in situ observation.

[The influence of the screw thread and the height of constraints on the stress distribution around dental implants by using three-dimensional finite element analysis].

OBJECTIVE: To study the influence of the screw thread and the height of constraints on the stress distribution of the implants. METHODS: The three-dimensional emulational models of the implants with different screw-pitch were constructed by a CAD/CAM package. The Von Mises stress of the models was analyzed by three-dimensional finite element method. RESULTS: The constraints of the long implant were high. When the constraint height reduced, the change of the stress value of the implants without screw thread was much less than that of the implants with screw thread. The difference of screw-pitch had little influence on the stress value and the stress concentration of the implants. CONCLUSION: The strength requirement of screw implant was high. Stress distribution of the long dental implants was more reasonable than the other, which will contribute to the success of dental implants.