Biomedical subjects

Alexander Pazur

Publications and source records attributed to Alexander Pazur.

4 recordsLinked to original sources

PubMed2006

Growth of etiolated barley plants in weak static and 50 Hz electromagnetic fields tuned to calcium ion cyclotron resonance.

BACKGROUND: The effects of weak magnetic and electromagnetic fields in biology have been intensively studied on animals, microorganisms and humans, but comparably less on plants. Perception mechanisms were attributed originally to ferrimagnetism, but later discoveries required additional explanations like the "radical pair mechanism" and the "Ion cyclotron resonance" (ICR), primarily considered by Liboff. The latter predicts effects by small ions involved in biological processes, that occur in definite frequency- and intensity ranges ("windows") of simultaneously impacting magnetic and electromagnetic fields related by a linear equation, which meanwhile is proven by a number of in vivo and in vitro experiments. METHODS: Barley seedlings (Hordeum vulgare, L. var. Steffi) were grown in the dark for 5 and 6 days under static magnetic and 50 Hz electromagnetic fields matching the ICR conditions of Ca2+. Control cultures were grown under normal geomagnetic conditions, not matching this ICR. Morphology, pigmentation and long-term development of the adult plants were subsequently investigated. RESULTS: The shoots of plants exposed to Ca2+-ICR exposed grew 15-20% shorter compared to the controls, the plant weight was 10-12% lower, and they had longer coleoptiles that were adhering stronger to the primary leaf tissue. The total pigment contents of protochlorophyllide (PChlide) and carotenoids were significantly decreased. The rate of PChlide regeneration after light irradiation was reduced for the Ca2+-ICR exposed plants, also the Shibata shift was slightly delayed. Even a longer subsequent natural growing phase without any additional fields could only partially eliminate these effects: the plants initially exposed to Ca2+-ICR were still significantly shorter and had a lower chlorophyll (a+b) content compared to the controls. A continued cultivation and observation of the adult plants under natural conditions without any artificial electromagnetic fields showed a retardation of the originally Ca2+-ICR exposed plants compared to control cultures lasting several weeks, with an increased tendency for dehydration. CONCLUSION: A direct influence of the applied MF and EMF is discussed affecting Ca2+ levels via the ICR mechanism. It influences the available Ca2+ and thereby regulatory processes. Theoretical considerations on molecular level focus on ionic interactions with water related to models using quantum electrodynamics.

Journal Article↗

PubMed2005

Magnetoreception in plants.

This article reviews phenomena of magnetoreception in plants and provides a survey of the relevant literature over the past 80 years. Plants react in a multitude of ways to geomagnetic fields-strong continuous fields as well as alternating magnetic fields. In the past, physiological investigations were pursued in a somewhat unsystematic manner and no biological advantage of any magnetoresponse is immediately obvious. As a result, most studies remain largely on a phenomenological level and are in general characterised by a lack of mechanistic insight, despite the fact that physics provides several theories that serve as paradigms for magnetoreception. Beside ferrimagnetism, which is well proved for bacterial magnetotaxis and for some cases of animal navigation, two further mechanisms for magnetoreception are currently receiving major attention: (1) the "radical-pair mechanism" consisting of the modulation of singlet-triplet interconversion rates of a radical pair by weak magnetic fields, and (2) the "ion cyclotron resonance" mechanism. The latter mechanism centres around the fact that ions should circulate in a plane perpendicular to an external magnetic field with their Lamor frequencies, which can interfere with an alternating electromagnetic field. Both mechanisms provide a theoretical framework for future model-guided investigations in the realm of plant magnetoreception.

DNA, Plant↗

PubMed2004

Characterisation of weak magnetic field effects in an aqueous glutamic acid solution by nonlinear dielectric spectroscopy and voltammetry.

BACKGROUND: Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under certain conditions already a aqueous solution of the amino acid and neurotransmitter glutamate shows this effect. METHODS: An aqueous solution of glutamate was exposed to a combination of a static magnetic field of 40 muT and a sinusoidal electromagnetic magnetic field (EMF) with variable frequency (2-7 Hz) and an amplitude of 50 nT. The electric conductivity and dielectric properties of the solution were investigated by voltammetric techniques in combination with non linear dielectric spectroscopy (NLDS), which allow the examination of the dielectric properties of macromolecules and molecular aggregates in water. The experiments target to elucidate the biological relevance of the observed EMF effect on molecular level. RESULTS: An ion cyclotron resonance (ICR) effect of glutamate previously reported by the Fesenko laboratory 1998 could be confirmed. Frequency resolution of the sample currents was possible by NLDS techniques. The spectrum peaks when the conditions for ion cyclotron resonance (ICR) of glutamate are matched. Furthermore, the NLDS spectra are different under ICR- and non-ICR conditions: NLDS measurements with rising control voltages from 100-1100 mV show different courses of the intensities of the low order harmonics, which could possibly indicate "intensity windows". Furthermore, the observed magnetic field effects are pH dependent with a narrow optimum around pH 2.85. CONCLUSIONS: Data will be discussed in the context with recent published models for the interaction of weak EMF with biological matter including ICR. A medical and health relevant aspect of such sensitive effects might be given insofar, because electromagnetic conditions for it occur at many occasions in our electromagnetic all day environment, concerning ion involvement of different biochemical pathways.

Journal Article↗

PubMedDate not supplied

Effects of a switched weak magnetic field on lecithin liposomes, investigated by nonlinear dielectric spectroscopy.

Three types of liposomes in aqueous solution were subjected to a low frequency switched weak magnetic field. A differential non-linear dielectric spectroscopy (DNLDS) was performed at 40 degrees C with two planar orthogonal electrodes, positioned parallel and vertical to the earth surface. The difference of the free voltage release (FVR) signals for the two orthogonal directions following electric pulses with an amplitude of 1.0 V and a duration of 25 ms, were Fourier-transformed. An additional magnetic field was switched with a period of 400 ms and a variable amplitude from 0 to 100 G, whose direction was parallel to the vertical electrode plane. With two of the liposomes (egg yolk lecithin (EY), asolectin doped with cholesterol (ASCO)) a decrease of the signal amplitude with increasing magnetic fields could be seen in most of the 25 observed harmonic frequencies (relative to the electric pulse frequency f(0) = 40 Hz). For EY liposomes this decrease was highly significant and not linear for the 1.-5., and above the 20. harmonic frequency, ASCO liposomes showed a similar effect. Asolectin liposomes showed the reverse response. Quantum mechanical conditions of charges on the liposome surface are discussed as a possible origin of these effects

Animals↗