Bernadeta Dobosz

EPR Study of Paramagnetic Centers in Human Blood

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.

Plant-pathogen interactions during infection process of asparagus with Fusarium spp.

BackgroundAsparagus officinalis L. is often infected by fungi from the Fusarium genus which also contaminate the plant tissues with highly toxic secondary metabolites. To elucidate the plant-pathogen interactions between asparagus and Fusarium oxysporum or F. proliferatum, a fungal mycotoxins profile was assessed together with an impact of the infection on all forms of salicylic acid content.MethodologyFungal isolates were identified by their morphological features, species-specific PCR and transcription elongation factor 1a (TEF-1a) sequencing. Mycotoxins were assessed by high-performance liquid chromatography (HPLC). The salicylic acid and its derivatives content was analyzed by the HPLC method combined with fluorometric detection. The levels of free radicals were measured by electron paramagnetic resonance (EPR).ResultsAfter infection both Fusarium pathogens formed fumonisin B1 and moniliformin. Infection altered salicylic acid biosynthesis and conjugation rates both in the roots and stems when compared with non-inoculated plants. Samples with higher free radical concentrations in stems showed higher concentrations of all forms of salicylic acid.ConclusionsWe postulate that infection by both Fusarium pathogens produces mycotoxins, which may be transported to the upper part of plant. Pathogen attack initiated a plant defense reaction involving increased salicylic acid levels and resulting in increase in free radical levels.

Measurement of Free Radicals Using Electron Paramagnetic Resonance Spectroscopy During Open Aorto-Iliac Arterial Reconstruction

Background Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals. The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD). Material/Methods The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction. Results Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09–77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56–82.12) and 24 h after the operation (25.85 U/L, range: 14.29–49.70). HO-1concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23–38.55), IL-6 was 141.22 pg/ml (84.3–591.03), TNF-alfa was 6.82 pg/ml (1.76–80.01) and AIOD: CRP was 18.44 mg/l (2.56–33.14), IL-6: 184.1 pg/ml (128.46–448.03), TNF-alfa was 7.74 pg/ml (1.74–74.74). Conclusions EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after surgery due to various endogenous antioxidants and therapies.

Study of As-Sb-Se chalcogenide glasses by NQR and EPR spectroscopy methods

In this paper experimental results obtained by both 75As NQR and EPR spectroscopy are presented for the three-component system As-Sb-Se. The 75As NQR spectra of glasses of structures (As2Se3)0.78 (Sb2Se3)0.22, (As2Se3)0.75 (Sb2Se3)0.25, (As2Se3)0.5 (Sb2Se3)0.5 have broad lines with two Sb-NQR lines (corresponding to the Sb2Se3 units) and two 75As-NQR lines (corresponding to the As2Se3 units). Differences in the EPR spectra of the different glasses arise because of the different amounts of arsenic and antimony in their structure.

Study of the EFG tensor at 75As nuclei in Ge‐As‐Se chalcogenide glasses

Asymmetry parameters of the electric field gradient tensor at 75As nuclei were determined for chalcogenide glassy semiconductors (CGS) of the Ge‐As‐Se system by comparing the experimental and simulated 75As nuclear quadrupole resonance nutation interferograms. The electric field gradient asymmetry in CGS was analyzed, and it is believed that a structural change in these glassy semiconductors takes place at r¯  =  2.425. Electron paramagnetic resonance spectra of the Ge‐As‐Se system were obtained for the first time. A comparison was made between the results of analysis of the Ge‐As‐Se system by nuclear quadrupole resonance and electron paramagnetic resonance methods, and this allowed us to make the supposition that a structural phase transition occurs at r¯  = 2.4 from two‐dimensional to three‐dimensional CGS structure. Copyright

Pulse Wave Shape Analysis of the Cardiovascular System Using High Signal Resolution

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.

EPR investigation of UV light effect on calcium carbonate powders with different grain sizes.

This study is based on investigation of calcium carbonate powders with different grain sizes exposed to UV light. Calcium carbonate is widely used in many branches of industry, e.g. as a filler for polymer materials; therefore, knowing its properties, among them also its reaction to UV light, is essential. Samples of powdered calcium carbonate with average grain sizes of 69 and 300 nm and 2.1, 6, 16, 25 µm were used in this investigation. Measurements were performed at room temperature using EPR X-band spectrometer, and they have shown the additional signals induced by the light from Hg lamp. The effect of annealing of the micro-grain samples was also studied. The spectra of four micro-grain samples after irradiation are similar, but there are differences between them and the other two powders, which could be related to the different sizes of their grains. Further studies based on these preliminary results may prove useful in research of photodegradation of CaCO3-filled materials, as well as helpful in increasing the accuracy of dating of archaeological and geological objects.

Investigation of lime mortars and plasters from archaeological excavations in Hippos (Israel) using Electron Paramagnetic Resonance

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 CO33− 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.

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

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).

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

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.