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  • Author: Ryszard Krzyminiewski x
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Abstract

Electron paramagnetic resonance investigations of paramagnetic centers in whole human blood were carried out at 170 K using X-band EPR spectrometer. The study included a group of patients and healthy volunteers. The EPR signals from high spin Fe3+ ions in transferrin (g = 4.2) and Cu2+ ions in ceruloplasmin (g = 2.05) are characteristic of each frozen blood sample. An overview of all recorded spectra revealed in several cases additional lines derived from high spin Fe3+ ions in methemoglobin (g = 5.8 - 6), free radicals (g = 2.002 - 2.005) and various low spin ferriheme complexes (g = 2.21 - 2.91). The lines from cytochromes (g = 3.03 and 3.27) were observed only twice. The EPR measurements have not confirmed the correlation between the occurrence of a particular type of low-spin iron complex and a specific disease entity. Moreover, the presence of EPR lines from trivalent iron also did not differentiate patients from healthy volunteers.

Changes in the cardiac muscle electric activity as a result of Coronary Artery Bypass Graft operation

Many bioelectric signals have a complex internal structure that can be a rich source of information on the tissue or cell processes. The structure of such signals can be analysed in detail by applying digital methods of signal processing. Therefore, of substantial use in diagnosis of the coronary arterial disease is the method of digital enhancement of increasing signal resolution ECG (NURSE-ECG), permitting detection of temporary changes in the electric potentials in the cardiac muscle in the process of depolarisation. Thanks to the application of NURSE-ECG it has become possible to detect relatively small changes in the electric activity of particular fragments of the cardiac muscle undetectable by the standard ECG method, caused by ischemia, the effect of a drug or infarct.

The aim of this study was to identify and analyse changes in the electric activity of the cardiac muscle as a result of the Coronary Artery Bypass Graft (CABG) operation. In this study the method of NURSE-ECG has been applied in order to identify and analyse changes in the electric activity of the cardiac muscle as a result of the CABG operation. In the study performed in cooperation of the Institute of Physics Adam Mickiewicz University and the Strus Hospital, Cardiac Surgery Ward, 37 patients with advanced coronary arterial disease were asked to participate. The patients were examined prior to the operation, on the day after the operation and two months after the operation and a year after the operation. The ECG recordings were subjected to a numerical procedure of resolution enhancement by a NURSE-ECG program to reveal the tentative changes in the electric potential of the cardiac muscle on its depolarisation. Results of the study have shown that the NURSE ECG method can be applied to monitor changes in the electric activity of the cardiac muscle occurring as a result of CABG operation. One the second day after the operation in the majority of patients (70%) a rapid decrease of the total cardiac muscle activity was observed. The NURSE ECG seems to be a promising supplementary method in medical diagnosis. In particular it can be applied for qualification of patients for CABG operation and for verification of the operation effects.

Free radicals in a conglomerate of peripheral blood with a spin trap investigated by the EPR method before and after angioplasty treatment

The Electron Paramagnetic Resonance (EPR) was used to investigate free radicals in the peripheral blood of patients subjected to angioplasty treatment. To detect these free radicals, a nitrosobenzene spin trap was used in this experiment. The EPR spectra of the blood with a spin trap conglomerate was measured at room temperature and at 170 K. To confirm the kind of free radicals in the conglomerate blood-spin trap, simulation and quantum-chemical calculations were made, and the conglomerate spin trap with ascorbic acid was measured. Two different types of radicals, one at room temperature and the other in a frozen sample of blood, were found.

Spin traps in the detection of free radicals in the blood of patients with ischemia

Electron Paramagnetic Resonance and a nitrosobenzene spin trap were used to investigate free radicals in the human blood after angioplasty treatment. The nitrosobenzene anion radical was determined using EPR measurements and quantum-mechanical calculations. Differences were observed in the concentration of free radicals before and after angioplasty treatment. These results were compared with myocardium damage parameters (CPK, MB and TnT).

The aim of this study was to carry out the FMD (flow - mediated dilatation) and NID (nitroglycerin-induced dilatation) tests in the case of patients with hypertension by using new measurement method - High Signal Resolution Pulse Wave (HSR PW). The paper presents new diagnostic method HSR PW which was used to evaluate the pulse wave in patients with arterial hypertension. HSR-PW is a method based on increasing the resolution of the pulse wave signal, recorded during a standard test using the Fourier Transform. The study involved twenty-four patients with hypertension and fifteen healthy people as a control group. The analysis showed that changes of the shape of the pulse wave in HSR PW took place in both groups conducting the FMD and NID tests. The HSR PW method proved to be more sensitive to changes in the body then the standard pulse oximeter and therefore may increase clinical practicability.

Abstract

This study presents the preliminary results of investigation of the lime mortars and plasters from archaeological excavations in Hippos (Israel), using Electron Paramagnetic Resonance (EPR) spectroscopy. The research was conducted in order to characterize the building material and its reaction to ionizing radiation. The ancient settlement Hippos, situated on the east shore of the Sea of Galilee, functioned from the 3rd cent. BC until it was destroyed by the earthquake in 749 AD. Lime mortars and plasters show carbonate and locally gypsum character of binder and different kind of aggregate. Samples were γ-irradiated and measured using X-band EPR spectrometer. Computer Resolution Enhancement Method was applied to the complex spectra. Some of the γ-induced EPR signals were attributed to CO2 − and CO3 3− paramagnetic centres. Exponential growth of the dose response curve above 1 kGy and saturation for doses above 20 kGy was observed. For doses lower than 1 kGy the dose response curve has a linear character. The presence of γ-sensitive carbonate paramagnetic centres could indicate that, after further studies, well-chosen samples of mortars and plasters might be suitable for EPR dating, assuming the centres have been sufficiently bleached during the manufacturing process.

Continuous microwave saturation of EPR spectra of melanin complexes at different temperatures

Paramagnetic centers in DOPA-melanin and complexes of DOPA-melanin with netilmicin and Cu(II) were studied by the use of an X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy. Measurements of continuous microwave saturation of EPR spectra at temperatures: 125 K, 175 K, 225 K, 275 K, were performed. Homogeneous broadening of all the examined EPR spectra was observed. EPR spectra of DOPA-melanin-Cu(II) complexes saturated at higher microwave powers than the others tested melanin samples. Fast spin-lattice relaxation exists in DOPA-melanin-Cu(II) complexes. Slow spin-lattice relaxation processes exist in melanin's paramagnetic centers of DOPA-melanin and its complexes with netilmicin, and its complexes with both netilimicin and Cu(II). EPR spectra of all the tested samples saturated at higher microwave powers with increasing of the measuring temperature. Faster spin-lattice relaxation processes occurs in DOPA-melanin and its complexes with netilmicin and Cu(II) at higher temperature.