Inhibition of the I and the activation of peak I contribute to the arrhythmogenic effects of aconitine and mesaconitine in guinea pigs.

Aconitine (ACO), a main active ingredient of Aconitum, is well-known for its cardiotoxicity. However, the mechanisms of toxic action of ACO remain unclear. In the current study, we investigated the cardiac effects of ACO and mesaconitine (MACO), a structurally related analog of ACO identified in Aconitum with undocumented cardiotoxicity in guinea pigs.

Three-dimensional culture and clinical drug responses of a highly metastatic human ovarian cancer HO-8910PM cells in nanofibrous microenvironments of three hydrogel biomaterials.

Background: Ovarian cancer is a highly aggressive malignant disease in gynecologic cancer. It is an urgent task to develop three-dimensional (3D) cell models in vitro and dissect the cell progression-related drug resistance mechanisms in vivo. In the present study, RADA16-I peptide has the reticulated nanofiber scaffold networks in hydrogel, which is utilized to develop robust 3D cell culture of a high metastatic human ovarian cancer HO-8910PM cell line accompanied with the counterparts of Matrigel and collagen I.

Cannabinoid type 2 receptor agonist JWH133 decreases blood pressure of spontaneously hypertensive rats through relieving inflammation in the rostral ventrolateral medulla of the brain.

Objective: Neuroinflammation in the rostral ventrolateral medulla (RVLM) has been reported to be associated with hypertension. The upregulation and activation of the cannabinoid type 2 (CB2) receptor may be part of the active process of limiting or downregulating the inflammatory process. This study was designed to determine the role of the CB2 receptor in blood pressure (BP) through relieving neuroinflammation in the RVLM in spontaneously hypertensive rats (SHRs).

Protective effect of berberine on acute cardiomyopathy associated with doxorubicin treatment.

Doxorubicin (DOX) is a potent and broad-spectrum anthracycline chemotherapeutic agent, but dose-dependent cardiotoxic side effects limit its clinical application. This toxicity is closely associated with the generation of reactive oxygen species (ROS) radical during DOX metabolism. The present study investigated the effects of Berberine (Ber) on DOX-induced acute cardiac injury in a rat model and analysed its mechanism in cardiomyocytes .

The regulation of FOXO1 and its role in disease progression.

Cell proliferation, apoptosis, autophagy, oxidative stress and metabolic dysregulation are the basis of many diseases. Forkhead box transcription factor O1 (FOXO1) changes in response to cellular stimulation and maintains tissue homeostasis during the above-mentioned physiological and pathological processes. Substantial evidences indicate that FOXO1's function depends on the modulation of downstream targets such as apoptosis- and autophagy-associated genes, anti-oxidative stress enzymes, cell cycle arrest genes, and metabolic and immune regulators.

Synthesis of La-Co-O Mixed Oxides via Polyethylene Glycol-Assisted Co-Precipitation Method for Total Oxidation of Benzene.

La-Co-O mixed oxides (LCO) were prepared by co-precipitation method with the presence of polyethylene glycol (PEG) as dispersant. The influence of adding different molecular weight of PEG (0, 2 000, 6 000, 20 000 g·mol-1) on the physicochemical and catalytic properties of La-Co-O mixed oxides for total oxidation of benzene was investigated. The samples were characterized by means of N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction by H2 (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), and X-ray photoelectron spectroscopy (XPS).

Tert-butylhydroquinone ameliorates doxorubicin-induced cardiotoxicity by activating Nrf2 and inducing the expression of its target genes.

Unlabelled: Oxidative stress plays an important role in doxorubicin (DOX)-induced cardiotoxicity. Nuclear factor E2-related factor-2 (Nrf2) is a transcription factor that orchestrates the antioxidant and cytoprotective responses to oxidative stress. In the present study, we tested whether tert-butylhydroquinone (tBHQ) could protect against DOX-induced cardiotoxicity in vivo and, if so, whether the protection was associated with the up-regulation of the Nrf2 pathway.

The effects of self-assembling peptide RADA16 hydrogel on malignant phenotype of human hepatocellular carcinoma cell.

The aim of this study will provide a self-assembling peptide (RADA16-I) -derived hydrogel as a tool for investigation the malignant phenotype of human hepatocellular carcinoma cell. Characteristic analysis indicated that the peptide consists of a well-defined secondary structure and self-assembly property. Our results showed that these cells cultured in RADA16-I hydrogels showed a spindle-shaped phenotype with irregular and radial nuclei.

Mechanisms of isoform-specific Na/K pump regulation by short- and long-term adrenergic activation in rat ventricular myocytes.

Background: Many stressful conditions, including cardiovascular diseases, induce long-term elevations in circulating catecholamines, thereby leading to changes of the Na/K pump and thus affecting myocardial functions. However, only short-term adrenergic regulation of the Na/K pump has been reported. The present study is the first investigation of long-term adrenergic regulation of the Na/K pump and the potential mechanism.

Mitochondrial permeability transition pore plays a role in the cardioprotection of CB2 receptor against ischemia-reperfusion injury.

The aim of this study was to investigate whether the mitochondrial permeability transition pore (MPTP) opening was involved in the protective effects of CB2 receptor against ischemia-reperfusion (I-R) injury. For this, isolated perfused rat hearts were subjected to 30 min global ischemia followed by 120 min reperfusion, and left ventricle function was recorded. At the end of reperfusion, the infarct size in the hearts was measured by staining with triphenyltetrazolium chloride.

[Protective effect of intermittent hypobaric hypoxia on cardiomyocytes injury induced by hydrogen peroxide].

Objective: To observe the protective effect and mechanism of intermittent hypobaric hypoxia (IHH) on cardiomyocytes induced by hydrogen dioxide.

Methods: Male guinea pigs were divided randomly into two groups (n = 10): intermittent hypoxia group (IHH), and control group (non-IHH). The IHH guinea pigs were exposed to a simulated 5,000 m high altitude and hypoxia in hypobaric chamber for 28 d, 6 h/d.

The H₁-H₂ domain of the α₁ isoform of Na+-K+-ATPase is involved in ouabain toxicity in rat ventricular myocytes.

The composition of different isoforms of Na+-K+-ATPase (NKA, Na/K pump) in ventricular myocytes is an important factor in determining the therapeutic effect and toxicity of cardiac glycosides (CGs) on heart failure. The mechanism whereby CGs cause these effects is still not completely clear. In the present study, we prepared two site-specific antibodies (SSA78 and WJS) against the H₁-H₂ domain of α₁ and α₂ isoforms of NKA in rat heart, respectively, and compared their influences on the effect of ouabain (OUA) in isolated rat ventricular myocytes.

Serotonin-mediated modulation of Na+/K+ pump current in rat hippocampal CA1 pyramidal neurons.

Background: The aim of this study was to investigate whether serotonin (5-hydroxytryptamine, 5-HT) can modulate Na+/K+ pump in rat hippocampal CA1 pyramidal neurons.

Results: 5-HT (0.1, 1 mM) showed Na+/K+ pump current (Ip) densities of 0.

Enhancement of Na/K pump activity by chronic intermittent hypobaric hypoxia protected against reperfusion injury.

Chronic intermittent hypobaric hypoxia (CIHH) has been shown to attenuate intracellular Na(+) accumulation and Ca(2+) overload during ischemia and reperfusion (I/R), both of which are closely related to the outcome of myocardial damage. Na/K pump plays an essential role in maintaining the equilibrium of intracellular Na(+) and Ca(2+) during I/R. It has been shown that enhancement of Na/K pump activity by ischemic preconditioning may be involved in the cardiac protection.

[Determination of palladium in automobile exhaust catalysts by FAAS method].

Palladium in automotive exhaust catalyst was determined by flame atomic absorption spectrometry (FAAS). The analytical conditions and the coexisting elements interference were studied. The catalyst was dissolved by the mixture of H2O2 and HCl.

Chronic intermittent hypobaric hypoxia protects the heart against ischemia/reperfusion injury through upregulation of antioxidant enzymes in adult guinea pigs.

Aim: To investigate the protection and the anti-oxidative mechanism afforded by chronic intermittent hypobaric hypoxia (CIHH) against ischemia/reperfusion (I/R) injury in guinea pig hearts.

Methods: Adult male guinea pigs were exposed to CIHH by mimicking a 5000 m high altitude (p(B)=404 mmHg, p(O2)=84 mmHg) in a hypobaric chamber for 6 h/day for 28 days. Langendorff-perfused isolated guinea pig hearts were used to measure variables of left ventricular function during baseline perfusion, ischemia and the reperfusion period.

Isoform-specific regulation of the Na+ -K+ pump by adenosine in guinea pig ventricular myocytes.

Aim: The present study investigated the effect of adenosine on Na(+)-K(+) pumps in acutely isolated guinea pig (Cavia sp.) ventricular myocytes.

Methods: The whole-cell, patch-clamp technique was used to record the Na(+)-K(+) pump current (I(p)) in acutely isolated guinea pig ventricular myocytes.

[Effects of pH value during synthesis on the structure and performance of ceria zirconia mixed oxides].

Heating reflux aging technology was first applied to obtain a series of ceria zirconia mixed oxides composed of 0.6CeO2-0.4ZrO2.

[The relationship between structure and oxygen storage capacity of Ce(x)Zr(1-x)O2 solid solution].

Heating reflux aging technology was applied to prepare a series of Ce(x)Zr(1-x)O2 (0.25 < or = x < or = 1) solid solution. The effects of the Ce(x)Zr(1-X)O2 composition on the structure and oxygen storage capacity were characterized using N2 physical adsorp tion, X-ray diffraction (XRD), FT-Raman, UV-Vis diffuse spectroscopy techniques.

[Diffusion reflectance spectroscopy of ZrO2 phase structure].

Diffusion Reflectance Spectroscopy (DRS) was employed to study the surface phase structure of ZrO2-based catalysts. The effect of calcining temperature, and the addition of Al2O3 and platinum on the surface and bulk phase structures of zirconia was studied by DRS combined with XRD, DTA and XPS. The same trend was observed that heating to higher temperatures results in the conversion to monoclinic zirconia in undoped samples, while incorporation of an appropriate amount of Al2O3 would stabilize the tetragonal phase zirconia.

[Study on the ultraviolet-visible spectra of Au/Al2O3 catalysts].

A variety of synthesis parameters for the preparation of gold nanoparticles by NaBH4 solution reduction in the W/O microemulsion media consisting of Cetyl Trimethyl Ammonium Bromide (CTAB)/n-hexanol/water system was investigated. The results showed that the molar ratio of water to surfactant (rw) had nothing to do with the gold particle size, but the concentration of the aqueous gold salt solution had a significant effect on the size of gold particle. Through optimizing the preparation parameters, Au/Al2O3 catalysts were prepared with two different methods, then the catalysts were characterized by ultraviolet-visible spectra, XRD and TEM, and the effect of two different preparation methods on active component gold particle size in the catalysts was studied.