Temporal and spatial fluctuations of heavy metals in Opa Reservoir,Ile-Ife,Nigeria

The Opa Reservoir, established for water supply to the Obafemi Awolowo University community, over the years has received direct linkage to township drains as a result of the widening and dredging of its river channels. The current study aimed at documenting monthly heavy metal loads at its riverine, transition and lacustrine zones in 2012–2013. Most of the heavy metals, analysed using an atomic absorption spectrophotometer, occurred within wide ranges, with coefficients of variation ranging from 60% to 300%, although the differences in heavy metal loads between the different zones were statistically insignificant at both the surface and bottom levels. The overall order of dominance of the metals was Ni > Cu > Fe > Zn > Cd = Cr > Pb, with nickel concentration being very high throughout. Heavy metal total mean concentration was higher during the rainy season (1.889 mg l?1) than the dry season (1.503 mg l?1) irrespective of sampling sites, having highly significant seasonal differences (p < 0.001) in Ni, Cd, Fe and Cu concentrations. The mean concentrations of Zn (0.074 mg l?1), Fe (0.176 mg l?1), Cu (0.507 mg l?1) and Pb (0.004 mg l?1) were within the WHO acceptable limit. However, the recorded levels of toxic elements Cd (0.031 mg l?1) and Ni (0.905 mg l?1) pose potential health risk to water consumers.     

The initiation of free radical peroxidation of low-density lipoproteins by glucose and its metabolite methylglyoxal: a common molecular mechanism of vascular wall injure in atherosclerosis and diabetes

It was found that glucose in the range of concentrations 12.5–100 mM stimulated Cu²⁺–mediated free radical peroxidation of low-density lipoproteins (LDL) from human blood plasma. Considering the kinetic parameters of LDL peroxidation we proposed that intensification of this process may be caused by formation of free radical intermediates of glucose auto-oxidation. Addition of SOD to the medium inhibited LDL oxidation, indicating the formation of superoxide anion-radicals under autoxidation of glucose. Similarly, SOD inhibited free radical peroxidation of liposomes from egg lecithin in the presence of glucose that confirms the generation of superoxide radicals under co-oxidation of unsaturated lipids and glucose. Normalization of glucose level in the blood of patients with type 2 diabetes mellitus during therapy was accompanied by a significant decrease in LDL oxidation in vivo (the decrease in primary and secondary lipoperoxidation products). The formation of superoxide anion-radicals was observed during interaction of aminoacid l-lysine with a product of glucose oxidative metabolism–methylglyoxal, but not with a product of lipoperoxidation malonyldialdehyde. In accordance with the foregoing the administration of sugar-lowering drug metformin, which binds and utilizes methylglyoxal, caused a stronger inhibition of LDL peroxidation in the blood of patients with diabetes mellitus, probably due to decrease in methylglyoxal-dependent generation of superoxide anion-radicals. Based on the results we set out the hypothesis about autocatalytic mechanism of free radical reactions involving natural dicarbonyls and suppose the common molecular mechanism of vascular wall injury in atherosclerosis and diabetes.     

Mass Spectrometric and Spectroscopic Studies of the Nutritional Supplement Chromium(III) Nicotinate

Despite chromium nicotinate’s popular use as a chromium nutritional supplement, the structure and composition of chromium nicotinate have only been poorly described. As solid chromium nicotinate is intractable, being insoluble or unstable in common solvents, studies on the solid have been limited, and studies of the solution from which the “compound” precipitates have additionally provided little additional data. The results of mass spectrometric and spectroscopic investigations designed to further elucidate the structure and composition of chromium nicotinate are described. The results demonstrated that the three common methods for producing “chromium nicotinate” all yield different compounds, all of which are polymers of Cr(III), oxygen-bound nicotinate, hydroxide, and water. Implications for interpreting results of nutritional studies of “chromium nicotinate” are discussed.     

Evolution of the CD163 family and its relationship to the bovine gamma delta T cell co-receptor WC1

Background  

The scavenger receptor cysteine rich (SRCR) domain is an ancient and conserved protein domain. CD163 and WC1 molecules are classed together as group B SRCR superfamily members, along with Spα, CD5 and CD6, all of which are expressed by immune system cells. There are three known types of CD163 molecules in mammals, CD163A (M130, coded for by CD163), CD163b (M160, coded for by CD163L1) and CD163c-α (CD163L1 or SCART), while their nearest relative, WC1, is encoded by a multigene family so far identified in the artiodactyl species of cattle, sheep, and pigs.     

Antioxidant and redox properties of supramolecular complexes of carotenoids with beta-glycyrrhizic acid

Supramolecular complexes between carotenoids and a triterpene glycoside, beta-glycyrrhizic acid (GA), were found to exhibit unusual antioxidant activity. Complexation with GA increases a scavenging rate of canthaxanthin and 7',7'-dicyano-7'-apo-beta-carotene toward OOH radicals more than 10 times, but has no effect on the scavenging rate of zeaxanthin. Scavenging rate constants were measured in DMSO solution of carotenoids using the EPR spin-trapping technique. EPR parameters of spin adducts were determined as a(H) = 2.3 G, a(N) = 13.9 G for PBN (N-tert-butyl-alpha-phenylnitrone)-OOH, and a(H) = 3.4 G, a(N) = 14.9 G for the PBN-CH3 adduct. Taking into account the previously measured dependence of the scavenging rate constants toward OOH radicals on the oxidation potential of carotenoids, this result can be explained by the hypothesis that the complexation with GA affects the value of oxidation potentials. This hypothesis was confirmed by CV measurements.     

Cholesterol-rich low density lipoproteins are also more oxidized

Cardiovascular diseases are accompanied by active oxygen species and organic free radical generation. The aim of this study was to examine the possibility of using oxidized low-density lipoprotein (oxLDL) as a new diagnostic biomarker. Epidemiological study in populations of Estonia (782 subjects) and Russia (1433 subjects) was carried out in 2007-2009. The screening procedure included standard epidemiological methods. Oxidative stress was assessed by measuring the level of oxLDL using immunoassay method. Positive correlation between the levels of oxLDL and LDL cholesterol was indicated in blood of patients from estonian (r = 0.61; P < 0.05) and russian (r = 0.56; P < 0.05) populations. In russian population oxLDL/HDL cholesterol ratio was higher in the groups with highest risk of atherosclerosis development or manifest coronary artery disease (CAD). Cholesterol-rich low density lipoproteins are also more oxidized. Estimation of oxLDL/HDL ratio may be used as an independent biochemical marker for atherosclerosis.     

Antiadhesion Effect of Materials Based on Carboxymethylchitosan and Carboxymethylcellulose

Applied Biochemistry and Microbiology - In this work, a model of adhesion formation in mice was optimized. It was shown that there were no significant differences in the level of adhesion between...