The aim of this study was to examine and compare the effects of the acute administration of verapamil or amlodipine as representatives of the calcium channel blockers or nicorandil as a representative of the mitochondrial ATP-dependent potassium (KATP) channel opener to cardiac contractility, coronary flow, and oxidative stress markers on ischemia/reperfusion injury in the isolated rat heart. The hearts of adult male Wistar albino rats (n = 60 total, 12 per group) were divided into five groups, two controls (preconditioning with Krebs–Henseleit solution) and three experimental depending on acute administrated pharmacological agents (0,63 µmol/L of verapamil, 0,1 µmol/L of amlodipine, and 200 µmol/L of nicorandil). After stabilization and 5 min of preconditioning in experimental groups, hearts from I/R control and all experimental groups underwent global ischemia (20 min) and reperfusion (30 min). Hearts from sham group were continuously followed for 50 min, after stabilization period. Cardiodynamic parameters and coronary flow were recorded at the end of stabilization (S), at the last minute of pharmacological preconditioning (P) and at intervals of 5 min after global ischemia, during reperfusion, or in case of sham group during 20–50 min after stabilization. At the same intervals, we collected coronary venous effluent from which we spectrophotometrically measured the parameters of oxidative stress: the index of lipid peroxidation, superoxide anion radical, hydrogen peroxide, and nitrite. In summary, our findings clearly indicate that the blocking of the calcium channel or the activation of KATP may mediate the protective effect of myocardial preconditioning. The ex vivo results showed that all examined drugs after ischemia and reperfusion have beneficial cardioprotective properties associated with lower values of major pro-oxidative molecules. Obtained effects seem to be the most convincible in case of nicorandil.
ABSTRACTIn this work, with Ni (110) as a model catalyst surface and CO2 as an adsorbate, a performance study of Density Functional Theory methods (functionals) is performed. CO being a possible intermediate in CO2 conversion reactions, binding energies of both, CO2 and CO, are calculated on the Ni surface and are compared with experimental data. OptPBE-vdW functional correctly predicts CO2 binding energy on Ni (?62?kJ/mol), whereas CO binding energy is correctly predicted by the rPBE-vdW functional (?138?kJ/mol). The difference in computed adsorption energies by different functionals is attributed to the calculation of gas phase CO2. Three alternate reaction systems based on a different number of C=O double bonds present in the gas phase molecule are considered to replace CO2. The error in computed adsorption energy is directly proportional to the number of C=O double bonds present in the gas phase molecule. Additionally, both functionals predict similar carbon–oxygen activation barrier (40?kJ/mol) and equivalent C1s shifts for probe species (?2.6?eV for CCH3 and +1.5?eV CO3?), with respect to adsorbed CO2. Thus, by including a correction factor of 28?kJ/mol for the computed CO2 gas phase energy, we suggest using rPBE-vdW functional to investigate CO2 conversion reactions on different metals. 相似文献
The vicious cycle between hyperinsulinemia and insulin resistance results in the progression of atherosclerosis in the vessel wall. The complex interaction between hyperglycemia and lipoprotein abnormalities promotes the development of atherogenesis. In the early phase of atherosclerosis, macrophage-derived foam cells play an important role in vascular remodeling. Mechanistic target of rapamycin (mTOR) signaling pathway has been identified to play an essential role in the initiation, progression, and complication of atherosclerosis. Recently sestrin2, an antioxidant, was shown to modulate TOR activity and thereby regulating glucose and lipid metabolism. But the role of sestrin2 in monocyte activation is still not clearly understood. Hence, this study is focussed on investigating the role of sestrin2 in monocyte activation under hyperglycemic and dyslipidemic conditions. High-glucose and oxidized low-density lipoprotein (LDL) treatments mediated proinflammatory cytokine production (M1) with a concomitant decrease in the anti-inflammatory cytokine (M2) levels in human monocytic THP1 cells. Both glucose and oxidized LDL (OxLDL) in a dose and time-dependent manner increased the mTOR activation with a marked reduction in the levels of pAMPK and sestrin2 expression. Both high-glucose and OxLDL treatment increased foam cell formation and adhesion of THP1 cells to endothelial cells. Experiments employing activator or inhibitor of adenosine monophosphate kinase (AMPK) as well as overexpression or silencing of sestrin2 indicated that high-glucose mediated monocyte polarization and adhesion of monocytes to the endothelial cells were appeared to be programmed via sestrin2-AMPK-mTOR nexus. Our results evidently suggest that sestrin2 plays a major role in regulating monocyte activation via the AMPK–mTOR-pathway under diabetic and dyslipidemic conditions and also AMPK regulates sestrin2 in a feedback mechanism. 相似文献
BackgroundOur aim was to estimate the overall and age-specific incidence of lab-confirmed dengue fever using ELISA based assays among children 6 months to 15 years in Delhi.MethodsWe enrolled a cohort of 984 children aged 6 months to <14 years in South Delhi and followed-up weekly for fever for 24 months or till 15 completed years of child-age. Households of the enrolled children were geo-tagged. NS1, IgM and IgG assays were conducted using ELISA method to confirm dengue fever in children with ≥3 consecutive days of fever. Molecular typing was done in a subset of NS1 positive cases to identify the circulating serotypes.Principal findingsWe had a total of 1953 person-years (PY) of follow up. Overall, there were 4208 episodes of fever with peaks during June to November. The overall incidence (95%CI) of fever was 215/100 PY (209 to 222). A total of 74/1250 3-day fever episodes were positive for acute dengue fever (NS1 and/or IgM positive). The overall incidence (95%CI) of acute dengue fever was 37.9 (29.8 to 47.6) per 1000 PY; highest among children aged 5 to 10 years (50.4 per 1000 PY, 95% CI 36.5 to 67.8). Spatial autocorrelation analysis suggested a clustering pattern for the dengue fever cases (Moran’s Index 0.35, z-score 1.8, p = 0.06). Dengue PCR was positive in 16 of the 24 specimens tested; DEN 3 was the predominant serotype identified in 15/24 specimens.ConclusionsWe found a high incidence of dengue fever among under 15-year children with clustering of cases in the community. DEN 3 was the most commonly circulating strain encountered. The findings underscore the need for development of affordable pre-vaccination screening strategy as well as newer dengue vaccines for young children while continuing efforts in vector control. 相似文献
We have used an in vitro system to monitor the effects of high levels of ammonia and ethanol on glial cells. Nuclei were isolated and the protein profiles examined by two-dimensional gel electrophoresis. Acute exposure of rat astrocyte cell cultures to ammonia or ethanol resulted in changes in cellular morphology and the level of some nuclear proteins. Glial fibrillary acidic protein (GFAP) levels remained constant under both treatments. Several nuclear proteins were increased specifically. Only one protein was visually detected which was unique to treatment with ammonia or ethanol. This protein (p2a) appeared only in the presence of ammonia. There were no changes in previously observed astrocyte-associated proteins (Silverman et al. Neurochem Int. 12, 513–518, 1988). Two proteins appeared de novo upon either treatment with either ammonia or ethanol. These latter proteins had a molecular weight and pI profile similar to the major class of nuclear stress proteins (hsp70). However, results from immunoblot experiments clearly demonstrated that hsp70 was not induced in astroycte cultures following exposure to ammonia or ethanol. 相似文献
Erythrocytes isolated from 131 cases of Non-Insulin Dependent Diabetes Mellitus (NIDDM) were studied for lipid peroxidation, antioxidant defences, and the maximum peroxidisable substrate in the cell membrane. Antioxidant defences are lowered in NIDDM, followed by significant rise in lipid peroxidation products. However, in the erythrocyte membrane, the total polyunsaturated peroxidisable lipids are lower than in normal erythrocytes which may be a causative factor affecting the survival of the cells. 相似文献
The polymerase chain reaction (PCR) has developed into one of the most promising methods for in vitro enzymatic amplification of DNA and has found widespread application in DNA cloning, sequencing and mutagenesis related studies. This innovative technique can selectively amplify a single target DNA molecule a billion-fold in a span of a few hours. Amplification of specific DNA sequences by PCR is useful in identification of sex, novel genes, pathogens and diseases. PCR has facilitated the establishment of evolutionary relationships among species and in revealing structural intricacies of single cells. In this article we review some of the major advances and applications of PCR, especially, its role in embryo sexing. 相似文献
Acinetobacter calcoaceticus MTC 127 was able to grow on catechin and protocatechuic acid (PCA) as sole carbon source. Cells induced with catechin oxidized catechin and PCA at rates higher than cells of uninduced cultures. Two aromatic compounds, PCA and phloroglucinol carboxylic acid (PGCA) were isolated from culture filtrate of cells grown in catechin and characterized by infrared spectrometry and high performance thin-layer chromatography. Moreover, A. calcoaceticus MTC 127 produced high levels of PCA compared to PGCA in the degradation of catechin. Based upon these results, a pathway for the degradation of (+)-catechin in A. calcoaceticus MTC 127 is proposed. Enzymes extracted from catechin-induced culture showed catechin oxygenase (cox) and protocatechuate 3,4-dioxygenase (pcd) activities. Catechin oxygenase was purified by column chromatography and SDS-PAGE analysis showed a single band with an apparent molecular weight of 47 kDa. 相似文献