Rahmi Köseoğlu

Trace metal concentrations in hair and nails from Alzheimer's disease patients: Relations with clinical severity.

BACKGROUND AND OBJECTIVES Metals, especially transition metals, seem to be important in the pathogenesis of Alzheimer disease. This study aims to determine the relationship of trace metal elements to the pathogenesis and/or course of Alzheimer Disease in terms of clinical severity. METHODS The hair and nail trace metal levels of 62 Alzheimer Disease patients at different clinical stages (21 mild, 20 moderate, 21 severe) and 60 healthy control subjects were measured by using inductively coupled plasma-mass spectrometry. The statistical comparisons were performed with regards to the study groups, clinical stages, disease duration and age. RESULTS The patient and control groups were significantly different from each other in regards to Mn, Fe, Cu, Cd, Hg (p<0.001), Zn (p<0.01) in nail concentrations and, Na, Al, Pb, Co (p<0.001), Fe, Mn (p=0.001), Hg, Cu, Cd, K in hair concentrations (p<0.01). No difference was detected in the levels of Mg and Ca. Nail Na level showed differences among different clinical stages of the disease (p<0.01). In comparing the mild degree Alzheimer patients to the control group; significant differences were detected in nail Mn, Fe, Cu, Co (p<0.001), Hg, Zn (p<0.01) and, hair Pb, Al (p<0.001), Na, K levels (p<0.01). CONCLUSIONS Our results have shown that transition and posttransition metals are especially important metals for the disease process. The relation of nail Na level with clinical stages of AD is an interesting new finding, making someone to think that alkali metals may be important in the progression of the disease.

Electron paramagnetic resonance of natural and γ-irradiated alunite and kaolin mineral powders

Natural alunite and kaolin minerals obtained from West Anatolia were investigated by electron paramagnetic resonance (EPR) in natural and γ-irradiated states at room temperature and at 113 K. The paramagnetic centres at ambient temperature in natural alunite were attributed to the ĊH2OH, , , and [AlO4]0 radicals. In natural kaolin, the paramagnetic centres were attributed to the , , and [AlO4]0 radicals. The γ-irradiation does not produce any detectable effects on these radicals. At 113 K, the lines for ĊH2OH could not be observed well, probably due to the anisotropic behaviour of the hyperfine interaction of the methylene protons, but the lines for [AlO4]0 centres were found to be perfectly observable at above 20 mW microwave power in both alunite and kaolin powders before and after γ-irradiation. The EPR parameters of the observed paramagnetic centres were reported.

EPR study of radicals produced by gamma-irradiation in marine mollusc (Venus sp.) fossils

In this study, gamma-irradiated marine mollusc (Venus sp.) fossils were investigated by electron paramagnetic resonance (EPR) at ambient temperature. Powder X-ray diffraction technique indicates that the Venus sp. fossils were made mainly of CaCO3. Before γ-irradiation, the EPR lines of the powder of fossil samples showed the existence of Mn2+ (I = 5/2, 100% natural abundance) ions with gav = 2.0055 and A av = 9.4 mT. γ-Irradiation-induced additional defects in Venus sp. fossil were attributed to axial (g ⊥ = 2.0171, g // = 2.0048), orthorhombic (g x  = 2.0030, g z  = 2.0018, g y  = 1.9973, g av = 2.0007), freely rotating (g iso = 2.0007), isotropic (g = 2.0057), axial (g ⊥ = 2.0036, g //; = 2.0024) and isotropic (g = 2.0032) free radicals. The g-values of these free radicals were compared with the literature data belonging to similar defects.

Disorder in KHCO3 as studied by EPR and DTA in Cu2+ doped and gamma-irradiated single crystals

Kalicinite (KHCO3) single crystals were investigated by the electron paramagnetric resonance (EPR) technique in their Cu2+ doped and gamma-irradiated states. It is observed that the behavior of the spectrum is the same at ambient and low temperatures down to 113 K in consistence with the monoclinic symmetry of the crystal. However, when the temperature is increased to 313 K, only one site signals were observed at all orientations of the magnetic field for the Cu2+ doped samples as the site splitted signals overlap at this temperature. Furthermore, for the gamma-irradiated crystals, two sites were observed for the induced and radicals at ambient temperature for an arbitrary orientation of the magnetic field. However, when the temperature is increased to 348 K, the signals due to the radical overlap indicating only one site, but the signals due to the radical do not and continue to indicate the presence of the two sites. Therefore, we conclude that this one site transition at 313 K is due to the disordering of the proton vacancies, as the charge compensation of Cu2+ is fulfilled by K+ and proton holes. This indicates that the proton vacancies come to disorder at 313 K and the protons get disordered at 348 K. The differential thermal analysis results show two small endothermic peaks for the Cu2+ doped and gamma-irradiated samples at 313 and 348 K that were attributed to the disorder of the proton vacancies and protons, in consistency with the EPR results.

EPR of γ-irradiation-induced free radicals in chicken, duck, and quail egg shells

Chicken, duck, and quail egg shells were γ-irradiated and investigated by electron paramagnetic resonance (EPR) at ambient temperature and at 113 K. The EPR-active species after γ-irradiation were attributed to the ĊO3−, ĊO33−, and ĊO2− radicals at ambient temperature and at 113 K. Furthermore, when the samples were stored in an oven at 423 K for about 1 h new EPR signals appeared at ambient temperature in addition to the above ones and these signals were attributed to the (CH3)2Ċ-R radical. These signals appear also at 113 K, but they are broadened likely due to the freezing of some of their motions. Any significant difference between the egg shells of poultry and those of village-grown chickens could not be observed in EPR spectra. The duck and quail egg shells exhibit the same signals and therefore indicate the inducement of the same radicals. The spectroscopic splitting and the hyperfine interaction values were found to be consistent with the literature data.

Crystal structure of 3,4a,7,7,10a-penta-methyl-3-vinyl-dodeca-hydro-1H-benzo[f]chromen-9-ol isolated from Sideritis perfoliata.

In the two independent molecules in the asymmetric unit of the title compound, the cyclohexane rings adopt a chair conformation, while the oxane rings are also puckered. In the crystal, O—H⋯ O hydrogen bonds connect adjacent molecules, forming a C(6) helical chain running along the [100] direction.

Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis­(furan-2-yl)-4-hy­droxy-4-(thio­phen-2-yl)cyclo­hexane-1,3-di­yl]bis­(thio­phen-2-yl­methanone)

The central cyclohexane ring has a chair conformation. In the crystal, molecules are linked by C—H⋯O hydrogen bonds and C—H⋯π interactions, forming layers parallel to (100).

EPR of Cu2+-doped Cs2CO3 and CsHCO3: evidence of the Jahn–Teller effect

Cu2+-doped Cs2CO3 and CsHCO3 single crystals were investigated by electron paramagnetic resonance between 113–273 and 173–313 K, respectively. For both single crystals, two sites were observed for the Cu2+ at ambient temperature for arbitrary orientations of the single crystals in the magnetic field. However, when the temperature is varied, the spectra indicate the equivalence of the two sites at 225 and 240 K for the single crystals, respectively, to the above order. Below and above these temperatures two sites for Cu2+ appear, and below 133 and 173 K the signals do not vary and two sites were always observed. This is attributed to the transition of the dynamic Jahn–Teller effect to a static situation at lower temperatures. Cu2+ seems to replace Cs+ and the charge compensation is fulfilled by another Cs+. Spin-Hamiltonian parameters for both single crystals at ambient temperature are reported and discussed.