Jingmin Zhou

Efficacy of ACE inhibitors in chronic heart failure with preserved ejection fraction — A meta analysis of 7 prospective clinical studies

BACKGROUND The effect of ACE inhibitors on the prognosis of chronic heart failure patients with preserved left ventricular ejection fraction remains controversial. AIMS To assess the impact of ACE inhibitors on the prognosis of chronic heart failure patients with preserved left ventricular ejection fraction. METHODS AND RESULTS Seven prospective studies evaluating the effect of ACE inhibitors compared to placebo or other classes of drugs, such as monotherapy or first-line therapy, on the prognosis of chronic heart failure patients with preserved left ventricular ejection fraction were included. A total of 2554 patients (mean age: 75.1 years, female: 58%) were recruited with an average follow up of 20.9 months. The primary etiology of heart failure with preserved ejection fraction was ischemic heart disease (33.7%), hypertension (69.1%) and diabetes mellitus (25.8%). Our results demonstrated that ACE inhibitors significantly reduced all-cause mortality (odds ratio, OR = 0.52; 95% Confidence Interval (CI), 0.41 to 0.64; P<0.01). Furthermore, ACE inhibitors were able to reduce heart failure related rehospitalization or treatment over 20.9 months (p<0.05) in a subgroup of patients aged over 75 years. However, death due to worsening of heart failure, heart failure related rehospitalization and any-cause readmission were not affected (OR = 0.88; 95% CI: 0.66 to 1.17; P = 0.37 for death due to worsening of heart failure; OR = 0.81; 95% CI: 0.63 to 1.05; P = 0.11 for heart failure related rehospitalization and OR = 0.88; 95% CI: 0.68 to 1.14; P = 0.33 for any-cause readmission, respectively). CONCLUSIONS In patients with chronic heart failure with preserved ejection fraction, ACE inhibitors reduced all-cause mortality without affecting mortality due to heart failure and any-cause rehospitalization.

Qiliqiangxin inhibits the development of cardiac hypertrophy, remodeling, and dysfunction during 4 weeks of pressure overload in mice.

Abstract Qiliqiangxin (QL), a traditional Chinese medicine, has been used in the treatment of chronic heart failure. However, whether QL can benefit cardiac remodeling in the hypertensive state is unknown. We here examined the effects of QL on the development of cardiac hypertrophy through comparing those of losartan in C57BL/6 mice underlying transverse aorta constriction for 4 weeks. QL and losartan were administrated at 0.6 mg and 13.4 mg·kg−1·d−1, respectively. Cardiac hypertrophy, function, and remodeling were evaluated by echocardiography, catheterization, histology, and examination of specific gene expression and ERK phosphorylation. Cardiac apoptosis, autophagy, tumor necrosis factor &agr;/insulin-like growth factor-1, and angiotensin II type 1 receptor expression and especially the proliferation of cardiomyocytes and phosphorylation of ErbB receptors were examined in vivo to elucidate the mechanisms. Transverse aorta constriction for 2 weeks resulted in a significant cardiac hypertrophy, which was significantly suppressed by either QL or losartan treatment. At 4 weeks after transverse aorta constriction, although the development of cardiac dysfunction and remodeling and the increases in apoptosis, autophagy, tumor necrosis factor &agr;/insulin-like growth factor-1, and angiotensin II type 1 receptor expression were abrogated comparably between QL and losartan treatments, QL, but not losartan, enhanced proliferation of cardiomyocytes, which was paralleled with dowregulation of CCAAT/enhancer-binding protein &bgr;, upregulation of CBP/p300-interacting transactivator with ED-rich carboxy-terminal domain 4, and increases in ErbB2 and ErbB4 phosphorylation. Furthermore, inhibition of either ErbB2 or CBP/p300-interacting transactivator with ED-rich carboxy-terminal domain 4 abolished the cardiac protective effects of QL. Thus, QL inhibits myocardial inflammation and cardiomyocyte death and promotes cardiomyocyte proliferation, leading to an ameliorated cardiac remodeling and function in a mouse model of pressure overload. The possible mechanisms may involve inhibition of angiotensin II type 1 receptor and activation of ErbB receptors.

Mechanism of charge generation in p -type doped layer in the connection unit of tandem-type organic light-emitting devices

A p-type doped organic layer combined with a hole-blocking layer has been experimentally demonstrated to serve as the charge generation unit in tandem-type organic light-emitting devices. The p-type layer functions as the source of both holes and electrons. Charge separation is explained by the tunneling model that the hole-blocking layer reduces the energy barrier for the electrons generated in the p-type layer to tunnel through into one light-emitting unit, while the holes generated in the p-type layer can transport to the other light-emitting unit easily under operation voltage.

Rationale and design of the β‐blocker in heart failure with normal left ventricular ejection fraction (β‐PRESERVE) study

Chronic heart failure with normal left ventricular ejection fraction (HFNEF) is not only common, but also carries a high risk of substantial morbidity and mortality. However, few studies have been conducted in this population and no proven treatment is available. Although β‐blockers are evidence‐based first‐line therapy in systolic heart failure, they have not been well studied in HFNEF.

Delayed-switch-on effect in metal-insulator-metal organic memories

We report a delayed-switch-on effect in organic memories; i.e., the organic memory devices can automatically switch from off state to on state after a certain period of time when biased at voltages below the threshold voltage. Meanwhile, the lower the voltage is, the longer the switching time will be. The time scales from milliseconds to about 104s with decreasing voltage. Moreover, by applying a certain voltage between threshold voltage and Vmax, intermediate states are also obtained. The existence of filamentary microconducting channels in the organic layer is proposed to be responsible for the observed switching phenomenon.

Metal-induced photoluminescence quenching of tri-(8-hydroxyquinoline) aluminum

Metal-induced photoluminescence (PL) quenching of organic thin film [tri-(8-hydroxyquinoline) aluminum (Alq)] has been investigated both experimentally and theoretically. By doing experiments in situ in high vacuum, we have measured the PL intensity of Alq film deposited on metal-doped Alq film or metal film as a function of its thickness. For the case of metal-doped Alq film, exciton diffusion length of Alq is derived as LD=8.6±0.1nm by analyzing experimental results and using a model based on diffusion and interface dissociation of excitons. For the case of metal film, another model considering exciton diffusion, interface dissociation, and nonradiative energy transfer to the metal is suggested to explain the experimental observation. Good agreement is achieved between theory and experiment.

High contrast organic light-emitting devices with improved electrical characteristics

High contrast organic light-emitting devices with low-reflection cathodes are fabricated. The cathode consists of a semitransparent metal layer, a phase-changing (PC) layer, and a reflective metal layer. With Al doped tris(8-hydroxyquinoline) aluminum as PC layer, devices exhibit the average reflectivity of the ambient light as low as about 13%. And its electrical characteristics are almost identical to that of a conventional device, although the thickness is increased by 70%. The improvement in conductivity could be attributed to the conductive Al cluster distributed in the organic matrix.

Effectiveness and Safety of Patient-Initiated Single-Dose versus Continuous Low-Dose Antibiotic Prophylaxis for Recurrent Urinary Tract Infections in Postmenopausal Women: A Randomized Controlled Study:

This study evaluated patient-initiated single-dose antibiotic prophylaxis and continuous long-term low-dose daily antibiotic use for the prevention of recurrent urinary tract infections (UTI) in 68 postmenopausal women. The women were randomized to take a low-dose antibiotic each night (continuous group, n = 37) or a single-dose antibiotic each time they experienced conditions predisposing to UTI (intermittent group, n = 31). During the 12-month study, 1.4 and 1.9 UTIs/patient developed in the continuous and the intermittent groups, respectively, which was significantly lower than the incidence of UTIs in the previous 12 months in these patients (4.7 and 5.1 UTIs/patient, respectively). The incidence of gastrointestinal adverse events was significantly lower in the intermittent group compared with the continuous group (9.1% versus 30.0%). In conclusion, patient-initiated single-dose intermittent antibiotic prophylaxis was as effective as low-dose daily antibiotic prophylaxis in the treatment of recurrent UTIs in postmenopausal women and was associated with fewer gastrointestinal adverse events.

Impact of Coronary Tortuosity on Coronary Blood Supply: A Patient-Specific Study

Background Tortuous coronary arteries are commonly observed in clinical screenings and it may cause a reduction of the coronary pressure. However, whether this reduction leads to significant decreasing in the coronary blood supply is still unknown. The purpose of this study was to investigate the effect of the coronary tortuosity (CT) on the coronary blood supply. Method A computational fluid dynamics (CFD) study was conducted to evaluate the impact of tortuosity on the coronary blood supply. Two patient-specific left anterior descending coronary artery (LAD) models and the corresponding non-tortuous models were reconstructed to perform three-dimensional CFD analysis. The lumped parameter model was coupled to the outlet of the simulated branches to represent the absent downstream vasculatures. The rest and exercise conditions were modeled by specifying proper boundary conditions. Result Under resting condition, the mean flow rate could be maintained by decreasing less than 8% of the downstream vascular beds resistance for tortuous models. While during exercise (maximal dilatation condition), the maximal coronary blood supply would reduce up to 14.9% due to tortuosity. Assuming that the flow rate can be maintained by the auto-regulation effect under the maximal dilatation condition, the distal resistances for CT models still have to reduce more than 23% to maintain blood perfusion. Conclusions Coronary tortuosity has minor influence on coronary blood supply at rest; while during exercise, patients with CT may lack the ability to adjust distal resistance sufficiently to compensate for the extra resistances generated by tortuosity and this may further lead to an ineffective regulation of the blood supply.

Computation of Hemodynamics in Tortuous Left Coronary Artery: A Morphological Parametric Study

Coronary tortuosity (CT) would alter the local wall shear stress (WSS) and may become a risk factor for atherosclerosis. Here we performed a systematic computational study to relate CT morphological parameters to abnormal WSS, which is a predisposing factor to the formation of atherosclerotic lesions. Several idealized left coronary artery (LCA) models were created to conduct a series of morphological parametric studies, in which we concentrate on three specific morphological parameters, the center line radius (CLR), the bend angle (BA), and the length between two adjust bends (LBB). The time averaged WSS (TAWSS), the oscillatory shear index (OSI), and the time averaged WSS gradient (WSSGnd) were explored by using the computational fluid dynamics (CFD) method, in order to determine susceptible sites for the onset of early atherosclerosis. In addition, two realistic LCA models were reconstructed to further validate the findings credibility. The CLR and LBB had great impact on the distributions of WSS-derived parameters, while the BA had minor impact on the hemodynamic of the tortuous arteries. Abnormal regions with low TAWSS (TAWSS < 0.5 Pa), high OSI (OSI > 0.1) and high WSSGnd (WSSGnd > 8) were observed at the inner wall of bend sections in the models with small CLR or small LBB. These findings were also confirmed in the realistic models. Severe CT with small CLR or LBB would lead to the formation of abnormal WSS regions at the bend sections and providing these regions with favorable conditions for the onset and/or progression of atherosclerosis.