ABSTRACT
The role of transition metal ions in atherogenesis is controversial; they can participate in the hydroxyl radical generation and catalyze the reactive oxygen species neutralization reaction as cofactors of antioxidant enzymes. Using EPR spectroscopy, we revealed that 70% of the samples of aorta with atherosclerotic lesions possessed superoxide dismutase activity, 100% of the samples initiated Fenton reaction and demonstrated the presence of manganese paramagnetic centers. The sodA gene encoding manganese-dependent bacterial superoxide dismutase was not found in the samples of atherosclerotic plaques by PCR using degenerate primers. The data obtained indicates the perspectives of manganese analysis as a marker element in the express diagnostics of atherosclerosis.
Subject(s)
Atherosclerosis/metabolism , Manganese/analysis , Manganese/physiology , Superoxide Dismutase/metabolism , Aorta/metabolism , Aorta/pathology , Bacterial Proteins/genetics , Biomarkers/analysis , Electron Spin Resonance Spectroscopy , Humans , Superoxide Dismutase/geneticsABSTRACT
W-band pulsed EPR and ENDOR investigations of X-ray irradiated nanoparticles of synthetic hydroxyapatite Ca(9)Pb(PO(4))(6)(OH)(2) are performed. It is shown that in the investigated species lead ions probably replace the Ca(1) position in the hydroxyapatite structure.
Subject(s)
Calcium/chemistry , Durapatite/chemistry , Lead/chemistry , Nanoparticles/chemistry , Phosphates/chemistry , Electron Spin Resonance Spectroscopy , Ions/chemistry , X-RaysABSTRACT
The influence of cross-linked by dimethylsuberimidate dimeric RNAse from Bacillus intermedius on peritoneal rat macrophages has been investigated in vitro. It has been shown that dimeric RNase with concentrations of 0.5-40.0 mg/ml decreases the functional activities of macrophages. This is manifested in the inhibition of the phagocyte function of macrophages and suppression of the fusion of phagosomes with lysosomes. The change in the cytoplasmatic membrane surface structure induced by the dimers, which is stronger than that induced by monomers, has been demonstrated using atomic force microscopy. The role of membrane properties modification in the inhibition effect of RNase dimers on the functional activities of macrophages is discussed.
Subject(s)
Bacillus/enzymology , Bacterial Proteins/pharmacology , Macrophages, Peritoneal/drug effects , Phagocytosis/drug effects , Ribonucleases/pharmacology , Animals , Bacterial Proteins/chemistry , Dimerization , Dimethyl Suberimidate/chemistry , Lysosomes/immunology , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/ultrastructure , Microscopy, Atomic Force , Phagosomes/immunology , Rats , Ribonucleases/chemistryABSTRACT
Four fractions of IgG antibodies to native DNA (nDNA) were obtained from blood of patients with systemic lupus erythematosus (SLE). These antibodies displayed a thermostable DNA-hydrolyzing activity and were different in affinity for DNA-cellulose and sorption on DEAE-cellulose. DNA-hydrolyzing antibodies to nDNA are metal-dependent endonucleases, cause mainly single-strand breaks in DNA, and are active over a wide range of pH. By atomic-force microscopy, three-dimensional images of DNA complexes with DNA-hydrolyzing antibodies to nDNA were obtained with nanometer resolution, and a nonprocessive action mechanism was shown for the DNase activity of antibodies to nDNA.
Subject(s)
Antibodies, Antinuclear/pharmacology , Deoxyribonucleases/metabolism , Lupus Erythematosus, Systemic/immunology , Adolescent , Adult , Antibodies, Antinuclear/blood , Antibody Affinity , Cellulose/analogs & derivatives , Cellulose/metabolism , DNA/metabolism , DNA, Circular/metabolism , Enzyme-Linked Immunosorbent Assay , Female , Humans , Hydrolysis , Lupus Erythematosus, Systemic/blood , Male , Middle AgedABSTRACT
The paper focuses on an alternative approach that allows one to identify overlapping band shapes with the help of the continuous wavelet transform (CWT). We show that less number of special points for determining a band shape is required unlike the fractional derivative spectrometry method [S.S. Kharintsev, M.Kh. Salakhov, Spectrochim. Acta Part A, 60 (2004) 2125]. Besides, the CWT-based derivative spectrometry can be successfully utilized in a case of complex spectra corrupted with a white and/or high-frequency noise. The power of this method is illustrated on model examples and experimental spectra of 1,2-diphenylethane in crystalline and melted phase.
Subject(s)
Algorithms , Spectrum Analysis/methods , Crystallization , Least-Squares Analysis , Mathematics , SolutionsABSTRACT
An approach based on the using of the continuous wavelet transform (CWT) in derivative spectrometry (DS) is considered. Within the framework of the approach we develop a numerical differentiation algorithm with continuous wavelets for improving resolution of composite spectra. The wavelet-based derivative spectrometry (WDS) method results in best contrast in differential curves compared to the conventional derivative spectrometry method. A main advantage is that, as opposed to DS, WDS gives stable estimations of derivative in the wavelet domain without using the regularization. A wavelet shape and the information redundancy are of the greatest importance when the continuous wavelet transform is used. As an appropriate wavelet we offer to utilize the nth derivative of a component with a priori known shape. The energy distribution into scales allows one to determine a unique wavelet projection and in that way to avoid the information redundancy. A comparative study of WDS and DS with the statistical regularization method (SRM) is made; in particular, limits of applicability of these are given. Examples of the application of both DS and WDS for improving resolution of synthetic composite bands and real-world composite ones coming from molecular spectroscopy are given.
Subject(s)
Spectrum Analysis/methods , Algorithms , Hydrocarbons, Brominated/chemistry , Hydrocarbons, Fluorinated/chemistry , Models, ChemicalABSTRACT
The nonlinear fitting method, based on the ordinary least squares approach, is one of several methods that have been applied to fit experimental data into well-known profiles and to estimate their spectral parameters. Besides linearization measurement errors, the main drawback of this approach is the high variance of the spectral parameters to be estimated. This is due to the overlapping of individual components, which leads to ambiguous fitting. In this paper, we propose a simple mathematical tool in terms of a fractional derivative (FD) to determine the overlapping band spectral parameters. This is possible because of several positive effects of FD connected with the behavior of its zero-crossing and maximal amplitude. For acquiring a stable and unbiased FD estimate, we utilize the statistical regularization method and the regularized iterative algorithm when a priori constraints on a sought derivative are available. Along with the well-known distributions such as Lorentzian, Gaussian and their linear combinations, the Tsallis distribution is used as a model to correctly assign overlapping bands. To demonstrate the power of the method, we estimate unresolved band spectral parameters of synthetic and experimental infra-red spectra.
