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Microwave-induced increase of amide I and amide II vibration bands and modulating functions of sodium-chloride, sucrose and trehalose aqueous solutions: The case study of Haemoglobin
Abstract
The effects of microwaves (MWs) on the secondary structure of haemoglobin were investigated by means of Fourier Transform Infrared (FTIR) Spectroscopy. A set of samples of 250μl of different hemoglobin aqueous solutions (also in the presence of sucrose, trehalose and NaCl) were exposed for 3 hours to 900 MHz mobile phone MWs at a magnetic field intensity around 18 mA/m. Quantitative spectral analysis revealed significant increases in intensity of amide I and II modes after exposure to MWs for haemoglobin in bidistilled water, but not for hemoglobin in sodiumchloride, sucrose and trehalose aqueous solutions. Indeed, MWs interaction with the a-helix structure increases its dipole moment, produces increases in intensity of amide I and II modes whose major contribution is related to the a-helix content. This effect did not result to be significant for haemoglobin in sodium chloride, sucrose and trehalose aqueous solutions.
... The most relevant effects of exposure of proteins to ELF-EMFs within exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), [2,3] that were observed up to now using Fourier Transform Infrared (FTIR) spectroscopy analysis, are represented by proteins unfolding and a-helix orientation toward the direction of applied field. [4][5][6][7][8][9][10][11][12][13][14][15][16] Indeed, FTIR spectroscopy is a valuable tool for analyzing cells and proteins, analyzing transitions between rotational and vibration energy levels, providing a large amount of information also on molecular species and biological systems. ...
... Finally, following the consolidated protocol of our previous studies, [5][6][7] we operated exposing SH-SY5Y neuronal-like cells to magnetic field at the intensity of 1.4 mT. ...
... However, in order to confirm that no change in temperature occurred during exposure around the culture medium, temperature was monitored with an accurate Pt100 probe, using a hand-held thermometer (model CTH 6200; Wika Wiegand, Klingenberg, Germany), following the protocol of previous studies. [5][6][7] Infrared spectroscopy ...
The aim of this study is to investigate the causes of the different response of Amide I and Amide II bands in neuronal-like cells under an applied magnetic field at extremely low frequency and intensity. A Lumos IR microscope of Bruker Optics coupled with a FTIR spectrometer equipped with a wide-band liquid nitrogen cooled mercury-cadmium-telluride detector were used to acquire images and FTIR spectra of SH-SY5Y neuronal-like cells under exposure to 50 Hz magnetic fields at the intensity of 1.4 mT, generated by two Helmholtz coils driven by an AC voltage and placed into an incubator in a 5% CO 2 /95% air humidified at 37 C. Using this experimental setup resulted that the Amide II vibration band in neuronal-like cells increased significantly more than Amide I band after 6 h exposure to 50 Hz magnetic fields. This result can be explained assuming that the following mechanisms occurred simultaneously after exposure to 50 Hz magnetic fields: the alignment of proteins a-helices in cellular membrane toward the direction of applied magnetic field and a significant increasing of N-H bending vibration in proteins structure. ARTICLE HISTORY
... For instance, aggregation mechanisms of proteins can change cellular functions inducing some diseases ( Bauer et al., 2000). FTIR spectroscopy evidenced that exposure to microwaves (MWs) induces orientation and unfolding of proteins (Calabrò & Magazù, 2013a, 2014a, Calabrò et al., 2012b). This result can be explained hypothesizing that EMFs in the MWs range can interfere with the sophisti- cated electromagnetic circuits of livings (Fröhlich, 1980;Hyland, 1998). ...
... Samples of 200 μL of each protein were located at 4 cm from the MWs source and the power density was continuously monitored using an SRM 3000 device (Narda Safety Test Solutions) such as accurately described in Calabrò and Magazù(2013b) and Calabrò et al. (2012b). ...
... In addition, the weak Amide II vibration band centered at 1545 cm −1 , that is due to the N-H bending and C-N stretching vibra- tions, was observed in the same infrared region. The first result that appeared after exposure to HF-EMF was represented by an increase in intensity of the Amide I band in proteins secondary structure (see Figures 1-4) which was already observed in previous studies (Calabrò & Magazù, 2016, 2017a, 2017bCalabrò et al., 2012b). This result can be easily explained assum- ing that the proteins' α-helix structure aligned itself toward the direction of the field, giving rise to an increase of the total amount of dipole moment of the protein, represented by the observed increase in inten- sity of the Amide I band (Calabrò & Magazù, 2017a, 2017b. ...
Samples of human hemoglobin, bovine serum albumin, lysozyme and myoglobin were used as prototype of proteins to investigate their response to exposure to high frequency electromagnetic fields (HF-EMFs), in order to study possible application to the treatment of cancer. To this aim, Fourier-transform infrared spectroscopy was used in the infrared region. The most evident result which appeared after 3 h exposure to HF-EMFs was a significant increase in intensity of the Amide I band and of CH2 bending vibrations, showing that the proteins aligned toward the direction of the field. In addition, proteins' unfolding and aggregation occurred after exposure to HF-EMFs. These findings can be explained assuming a resonance interaction between the natural frequencies of proteins and HF-EMFs, which can induce iperpolarization of cells. Given that cancerous tissues were found to have natural frequencies different from natural frequencies of normal tissues, we can hypothesize to irradiate cancerous tissues using EMFs at natural frequencies of cancer cells, causing resonant interaction with cellular membrane channels, inducing increasing of ions' flux across cellular channels and damaging the cellular functions of cancer cells.
... However, it is a matter of fact that a huge number of studies on several effects on biological systems of EMFs emitted by human activities at very low intensities and regardless of the frequency of the field have been published so far. Furthermore, the fact that these effects have been significantly detected and quantified even on very simple organic systems such as proteins and cells leave no doubt as to the existence of such effects [1][2][3][4][5]. Nevertheless, some researchers have pointed out that these effects do not find any theoretical explanation despite having been observed experimentally. ...
... and the number of molecules that are rotated by an angle φ with respect to the direction of the field is given by (5) in which N is the total amount of paramagnetic molecules per unit of mass, μ is the molecular magnetic permeability and H is the applied MF [32]. ...
... FTIR spectroscopy can be considered as a valuable tool for analyzing the structure of proteins or other simple organic systems in aqueous solutions [2,3]. The use of this technique has evidenced a significant increase in intensity of proteins Amide I and Amide II vibration bands after exposure of typical proteins in water solutions to an electromagnetic field at a low intensity at 100mW/ m2 in the range 0.9 -2.5 GHz [4][5][6][7]. These vibration bands are characteristic of proteins secondary structure and are due above all to the α-helix content. ...
... Hence, an increasing of Amide I and II bands can be explained assuming that proteins α-helix aligned along the direction of applied electromagnetic field inducing an increasing DOI: 10.26717/BJSTR.2021.38.006176 30499 of total amount of dipole moment. Typical proteins in bidistilled water solution were used in these experiments [4][5][6] in order to schematize cellular environment in which they are embedded. This effect was also observed in typical human cells [8][9][10][11][12][13]. ...
Biological systems have magnetic properties due to microscopic atomic dipoles in their compounds which align themselves individually if a magnetic field is applied. As a result, a biological system can align along the direction of an applied magnetic field following the theory of paramagnetism. This effect can be induced also in simple organic systems. For instance, the α-helix is the main structure of a protein. We should not be surprised by this effect as proteins α-helix has generally a relevant dipole moment which allows possible orientation of a protein along the direction of an applied electromagnetic field. For instance, hemoglobin has a dipole moment of 280 D [1]. Instead, what makes us wonder is the fact that this effect occurs even at very small intensity of an electromagnetic field regardless of its frequency. In order that this effect can be highlighted a sophisticated technique should be used, that is Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectroscopy can be considered as a valuable tool for analyzing the structure of proteins or other simple organic systems in aqueous solutions [2,3]. The use of this technique has evidenced a significant increase in intensity of proteins Amide I and Amide II vibration bands after exposure of typical proteins in water solutions to an electromagnetic field at a low intensity at 100mW/ m2 in the range 0.9-2.5 GHz [4-7]. These vibration bands are characteristic of proteins secondary structure and are due above all to the α-helix content. Hence, an increasing of Amide I and II bands can be explained assuming that proteins α-helix aligned along the direction of applied electromagnetic field inducing an increasing
... Indeed, FTIR spectroscopy is capable to supply correct data on the secondary structure of proteins and biological systems. In addition, due to its accurateness, it is possible to quantify the reaction of a biological system to an EMF, such as it has been highlighted by relevant studies published in recent years (Emanuele et al., 2012;Calabro & Magazu, 2014;Calabrò & Magazù, 2015;Calabrò, 2016;Calabrò & Magazù, 2016;Magazù et al., 2016;Calabrò & Magazù, 2017a;Calabrò & Magazù, 2017;Calabrò & Magazù, 2018a;Calabrò & Magazù, 2018b;Calabrò & Magazù, 2019a;Calabrò & Magazu, 2019). This is the main proof why this technique has been selected to hypothesize to carry out this important study for dangerous viruses inactivation like SARS-CoV-2. ...
... The authors of this study have already shown by FTIR spectroscopy that EMFs denature proteins of simple organic systems similarly to heat. Indeed, significant comparative enhancement in the β-sheet ingredient considering the α-helix content in proteins secondary structure was observed after exposure to EMFs even at low intensity and this effect was much more evident at high-frequency values (Emanuele et al., 2012;Calabrò & Magazù, 2015;Calabrò & Magazù, 2016;Calabrò & Magazù, 2017a). Protein denaturation is a necessary condition to inactivate virus capsid so that it can be hypothesized to use HF-EMFs at a resonant frequency to emphasize this effect, that environments can be decontaminated without damaging human organism because of the differences between their natural frequencies. ...
In previous literature, several studies have highlighted both harmful and beneficial effects of electromagnetic fields for human beings and, in particular, possible applications for the treatment of some diseases. In this regard, we hypothesize that a possible application of beneficial effects of electromagnetic fields can be represented by irradiating lethal viruses such as SARS-CoV-2 by electromagnetic fields at frequencies close to the natural resonant frequencies of virus capsid and genome, inducing a relevant harmful alteration in its structure. Exposure of weakened virus samples to high-frequency electromagnetic fields at a frequency ranging from 1 to about 40 GHz, for instance, can be carried out by a variable frequency voltage generator and a signal amplifier to detect frequencies at which amplification of Amide and phosphate vibration bands occurs that should induce virus inactivation. FTIR spectroscopy can be used to evaluate the results of exposure. Amide I and II modes and phosphate vibration bands are characteristic of virus capsid and genome, respectively, so that their amplification at a resonant frequency should induce virus damage. Once resonance frequency of SARS-CoV-2 is found for one of its structures, living human spaces can be irradiated by electromagnetic radiation at such frequency to decontaminate not only surfaces but in particular air, contrary to what common disinfectants can do. This methodology could be implemented quite quickly pending the long time required for vaccinations.
... This delicate equilibrium can be changed by an external stress such as EMF, as it was already shown in previous studies. In particular, a significant increasing of the Amide I vibration band of typical proteins was the most relevant result induced by exposure to SMF or to high frequency (HF)-EMF [36][37][38][39][40]. In this study we showed that H/D isotopic exchange reduces significantly this effect in HB aqueous solution after exposure to EMFs. ...
... In particular this explanation fits well to the results of this study. In fact, in previous studies the increasing in intensity of the Amide I band in the secondary structure of proteins exposed to SMFs or to HF-EMFs was explained assuming that proteins α-helices align along the direction of the applied EMF, which induces a torque on the protein due to the α-helix dipole moment [18,[36][37][38][39][40]. For instance, HB has a dipole moment μ = 280 D [53] due to the dipole moment of its α-helices. ...
Samples of hemoglobin in deuterium oxide solution (D2O) and in bidistilled H2O water solution, both at the concentration of 100 mg/ml, were exposed to a static magnetic field at 100 mT; analogous samples were exposed to 50 Hz magnetic field at 1 mT. Fourier Transform Infrared (FTIR) Spectroscopy was used to analyze separately the response of the secondary structure of this protein (diluted in both aqueous solutions) to separated exposure to both magnetic fields. The most relevant result which was observed after exposures was the significant increasing in intensity of the Amide I band, which was already explained in previous studies assuming that proteins α-helix aligned along the direction of the applied magnetic field due to its large dipole moment. In particular, in this study it was shown that hydrogen/deuterium exchange induced a reduction of the increasing of Amide I vibration band. This result can be explained assuming that Amide hydrogens of hemoglobin exchange with solvent deuterium atoms, causing an increase in mass of the protein and a correlated increasing in inertia of the α-helix, reducing significantly the torque effect of the applied magnetic field.
... As cellular telephone technology has advanced, the modulation patterns have become increasingly complex and difficult to investigate possible health effects of mobile phone radiations on organic systems. Previous studies on the effects of mobile phone MWs on human health and organic systems have been carried up to now showing that mobile phone MW radiation, in addition to heating, induces non-thermal effects in narrow frequency windows that cannot be explained by bulk heating [1][2][3][4][5][6][7][8][9][10][11]. ...
... The possibility of induction of chemical, biological, and health effects was investigated by a great number of studies carried out up to now [1][2][3][4][5][6][7][8][9][10][11]. ...
The aim of this study was to verify the validity of the far-field approximation for a mobile phone during a call. Typical models of mobile phones were used to measure the electromagnetic field emitted during a call at various distances from the mobile phone using a selective radiation meter Narda SRM 3000. The near-field and far-field theories were applied to obtained measurements. As a result, the far-field approximation could be applied also at a few centimeters from the mobile phone. Nevertheless, it resulted that the best accuracy of the application of the far-field approximation to mobile phones working is obtained at distances larger than 40 cm, in agreement with the theoretic formulations relative to the condition that the antenna dimension is lesser than the wavelength of microwave radiation used by mobile phone working.
... Moreover, previous studies on the effects of microwaves (MWs) on some proteins in aqueous solution have shown that in addition to heating, MW radiation induces some non-thermal effects in their secondary structure that cannot be explained as due to bulk heating alone [12][13][14][15]. ...
... Finally, the third used exposure system for 3 h exposure to MWs consisted of an operational mobile phone to which a sound was transmitted from another mobile phone as accurately described in [12,13]. The obtained H-field value, at the average intensity of 21 mA/m at 1800 MHz frequency, was obtained during exposure, monitored by a SRM-3000 instrument of Narda Safety Test Solutions in time analysis mode. ...
The present review paper deals with experimental findings on the shielding action effects of two homologous disaccharides, i.e. sucrose and trehalose, against applied electromagnetic fields. The study, performed by means of the Fourier Transform InfraRed technique, is addressed to examine the effects of electromagnetic fields exposure on the secondary structure of some prototypal proteins (haemoglobin, bovine serum albumin and lysozyme) in aqueous solution, both in the absence and presence of the disaccharides. More specifically, haemoglobin and bovine serum albumin water solutions, in the absence and presence of sucrose and trehalose, were exposed to a uniform magnetic field of 200 mT. The intensity of the amide A vibration band, for both haemoglobin and bovine serum albumin in bidistilled water solution, drops down after three hours of exposure. The addition of sucrose and trehalose reduces such a decrease. Moreover, a three hours of exposure to a 50 Hz electromagnetic field at 1 mT of aqueous solutions of haemoglobin causes a relative increase in intensity of the β-sheet component with respect to the α-helix component in the amide I region; no appreciable spectral modifications were observed in haemoglobin samples in the presence of trehalose or sucrose. Finally, the effects of 1800 MHz microwaves on haemoglobin, bovine serum albumin and lysozyme aqueous solutions were investigated under a 3 h exposure of a 21 mA/m H-field (average intensity). FTIR analysis reveals a significant increase in intensity of proteins amide I and II modes after exposure, but no appreciable changes are detected for haemoglobin in the presence of sucrose and trehalose, confirming the hypothesis that disaccharides preserve proteins from electromagnetic fields.
... Indeed, the primary sign of neurological diseases such as Alzheirmer, Parkinson and Huntington is proteins aggregation [13][14][15][16]. Finally, more relevant sign of denaturation was observed after exposure to microwaves of Hb, Lys and Mb in bidistilled water solution, but this effect did not occur in samples in trehalose aqueous solution [17][18][19][20][21]. ...
In this brief review paper the protective effectiveness of trehalose
against magnetic fields was shown. FTIR spectroscopy was used to study this protective effectiveness and, to this aim, typical proteins in water solutions in absence and in presence of trehalose were used. Trehalose is a disaccharide such as sucrose, having the same chemical formula C12H22O11 and the same number of hydroxyl groups.The importance of this study is due to several experimental observations of harmful effects of EMFs on biological systems that were reported in literature. In the light of obtained results we can conclude that trehalose stands out as a good bioprotector against harmful effects of EMFs.
... Regarding mobile wireless technologies up to 4G, it has been shown that even exposure to high-frequency electromagnetic fields induces denaturation and aggregation and proteins alignment to the applied field, at a power density value of about 1 W/m 2 , that is, a value well below of the limit recommended by the ICNIRP for high frequency electromagnetic fields [8]. In particular, this result was observed in typical proteins in aqueous solution (hemoglobin, myoglobin, bovine serum albumin, lysozyme) after exposure for 3-6 h at the GSM frequencies of mobile phones to that power density of about 1 W/ m 2 [29][30][31][32][33][34]. ...
New emerging technology 5G will require higher speed, power and capacity in data transmission than previous generation, in order to obtain a complete world-wireless communication without limitation. In this scenario, given that the achievement of 5G technology will lead to a drastic increase of effects of exposure to microwave radiation, a strategy to reduce the effects of exposure to electromagnetic fields is needed. In this regard, given that cellular functions of human beings depend closely on ions flux across cellular membrane, whose mechanism should have its natural resonant frequencies, we can hypothesize to plan new emerging wireless technology 5G at frequencies far from these resonant frequencies in order to minimize the effects of exposure to extremely high frequency electromagnetic fields, inducing a significant decreasing of harmful effects on human health. We have named these frequencies “non-resonant frequencies”.
... Also exposure to HF-EMFs, at the intensity around 1 W/m 2 (that is, below the limit recommended by ICNIRP for exposure to HF-EMF (ICNIRP, 1998), induced proteins unfolding and aggregation. In particular, this result was observed in typical proteins in aqueous solution, exposed for 3-6 h to mobile phone MWs at 900 or 1800 MHz Calabrò, Magazù and Campo, 2012;Calabrò and Magazù, 2015a;Calabrò and Magazù, 2015b;Calabrò and Magazù, 2016;Calabrò and Magazù, 2017c). Typical exposed and unexposed second-derivative spectra of BSA are represented in Figure 3. . ...
This is the post-print version of the following article: "Characterizing Alterations in the Secondary Structure of Typical Proteins under Exposure to Electromagnetic Fields", which has been published in final form at https://novapublishers.com/shop/advances-in-chemistry-research-volume-42/
... FTIR spectroscopy is notoriously a valuable tool for studying the response of molecular vibrations in biological systems. In particular, it was already successfully used to study the response to EMFs of proteins and cells, highlighting some alterations not directly visible (Calabrò 2016;Calabrò and Magazù 2014a, 2014b, 2016Calabrò and Magazù 2017a;Calabrò et al. 2012;Magazù and Calabrò 2011;Magazù et al. 2016Magazù et al. , 2012. ...
The aim of this study was to investigate the response of chromosomes in typical human and plant
cells under applied low-frequency magnetic fields at low and high intensities. Neuronal-like cells and
roots of Alliumsativumand Vicia faba were used to investigate chromosome's response to a static and
50 Hz magnetic fields at intensities ranging from 1 mT to 0.8 T, generated by two Helmholtz coils
driven by direct current or alternate current voltage. Vertex spectrometer and Olympus microscope
with camera were used. A significant decrease in intensity of the phosphate bands in the DNA infrared
region was observed by FTIR spectroscopy analysis after exposure of neuronal-like cells to static and
50 Hz magnetic field at low intensity of 1 mT, which can be explained assuming that uncoiling and
unpackaging of chromatin constituents occurred after exposure. This effect was directly observed by
microscope in roots of Allium sativum and Vicia faba under exposure to a static magnetic field at high
intensity of 0.8 T. These findings can be explained assuming that exposure to both low- and highintensity
magnetic fields of chromosomes in typical human and plant cells induces uncoiling and
unpackaging of chromatin constituents, followed by chromosome alignment towards the direction of
applied magnetic field, providing further demonstration that magnetic fields can induce the orientation
of organic macromolecules even at low-intensity values.
... FTIR spectroscopy is notoriously a valuable tool for studying the response of molecular vibrations in biological systems. In particular, it was already successfully used to study the response to EMFs of proteins and cells, highlighting some alterations not directly visible (Calabrò 2016;Calabrò and Magazù 2014a, 2014b, 2016Calabrò and Magazù 2017a;Calabrò et al. 2012;Magazù and Calabrò 2011;Magazù et al. 2016Magazù et al. , 2012. ...
The aim of this study was to investigate the response of chromosomes in typical human and plant cells under applied low-frequency magnetic fields at low and high intensities. Neuronal-like cells and roots of Allium sativum and Vicia faba were used to investigate chromosome's response to a static and 50 Hz magnetic fields at intensities ranging from 1 mT to 0.8 T, generated by two Helmholtz coils driven by direct current or alternate current voltage. Vertex spectrometer and Olympus microscope with camera were used. A significant decrease in intensity of the phosphate bands in the DNA infrared region was observed by FTIR spectroscopy analysis after exposure of neuronal-like cells to static and 50 Hz magnetic field at low intensity of 1 mT, which can be explained assuming that uncoiling and unpackaging of chromatin constituents occurred after exposure. This effect was directly observed by microscope in roots of Allium sativum and Vicia faba under exposure to a static magnetic field at high intensity of 0.8 T. These findings can be explained assuming that exposure to both low-and high-intensity magnetic fields of chromosomes in typical human and plant cells induces uncoiling and unpackaging of chromatin constituents, followed by chromosome alignment towards the direction of applied magnetic field, providing further demonstration that magnetic fields can induce the orientation of organic macromolecules even at low-intensity values. ARTICLE HISTORY
... Power density produced by this exposure system was monitored by an SRM-3000 device of Narda Safety Test Solutions during time exposure, following the procedure described in Calabrò, Magazù, and Campo (2012), , 2014b, 2015. ...
The aim of this paper was to study the response of methyl (CH3) and methylene (CH2) vibration bands in amino acids of some typical proteins diluted in bidistilled water solution after exposure to a high-frequency electromagnetic fields using Fourier Transform Infrared (FTIR) Spectroscopy. Hemoglobin in H2O solution and bovine serum albumin and myoglobin diluted in different D2O solutions were exposed for 4 h to a power density of 0.95 W/m² at the frequency of 1750 MHz, emitted by operational mobile phones Nokia model 105 and Samsung model GT-E1270, in order to study the response of stretching vibrations of CH3 and CH2 that are in amino acids of those proteins. The main result was that CH3 stretching bands increased significantly in myoglobin in D2O solution because this protein is represented by a single protein chain so that the torque induced by the applied field is larger than that induced on the other two proteins. Otherwise, CH2 stretching vibrations decreased in intensity significantly for all exposed proteins. This result can be explained as well, assuming that, given a fixed volume, a decrease of population of CH2 occurred after exposure because of the alignment of proteins α-helices along the direction of the applied electromagnetic field.
... The most representative bio-protectors that have been considered up to now have been investigated to protect living beings from chemical pollution, which is caused by human discharge of chemical compounds into atmosphere and marine water [16][17][18][19][20][21][22][23][24][25][26][27][28]. In the last years, also the achievement of wireless technology throughout the world has produced the electromagnetic wave pollution, inducing researchers to study some bio-protective effectiveness against man-made electromagnetic fields [29][30][31][32][33][34][35][36][37][38][39]. ...
... In addition, some in vitro experiments showed that RF-MWs can be carcinogens and can induce DNA damage [40][41][42][43][44][45][46]. Alterations in the secondary protein's structure were also observed, represented by protein aggregation and alignment towards an applied HF-EMF [47][48][49][50][51][52][53][54][55], giving evident proof that exposure to HF-EMFs causes significant non-thermal effects even in simple organic systems. ...
Modern technology has largely developed using energy forms of which the most relevant is surely electricity. Electric power stations generate alternate current at frequencies of 50 or 60 Hz, transmitted across high voltage transmission lines that are often located too near to buildings where humans live or work. In addition, home devices that work using alternate current expose humans to extremely low-frequency electromagnetic fields. Furthermore, trams, electric trains, and some industrial processes generate static magnetic fields. Electromagnetic fields produce non-ionizing radiation, which gives rise to the so-called electromagnetic waves pollution, also named electrosmog. A large scientific production study showed harmful effects of exposure to EMFs. In view of these results, the International Commission on Non-Ionizing Radiation Protection published international guidelines in order to recommend exposure limits to EMFs for occupational exposure and for general public exposure. The aim of this thematic issue is to give a further contribution to highlight the problem of electromagnetic waves pollution and to investigate the effects of exposure to EMFs on biological systems even below the EMF limits recommended by ICNIRP.
... Previous literature showed that alterations of proteins secondary structure occur after exposure to mobile phone microwaves. [23][24][25][26][27] An increase in intensity around 1665 cm -1 (indicated by arrow in Fig. 2a) can be observed in the spectrum of bovine meat sample heated in microwave oven, that can be attributed to β-turns, characteristic of disorder processes in the protein. [28,29] A relative increase of β-sheet component at 1695 cm -1 with respect to the α-helix structure was observed after microwave heating in comparison to conventional heating (see Fig. 2a). ...
The effects of microwaves at 2450 MHz at 600 W on bovine muscle tissue have been studied by means of Fourier transform infrared spectroscopy. Spectral analysis in the amide I region after microwave cooking showed that an increase in intensity occurred in the region around 1665 and 1695 cm-1, that can be attributed to β-Turns and β-sheet features, respectively. This result characterized disorder processes in the protein. In addition, CH2 methylene and carbonyl band vibrations of samples under exposure to microwave heating appeared lower than vibrations of samples heated by conventional oven. This result demonstrated that the Maillard reaction occurs partially after cooking by microwave oven.
... This analysis relative to hemoglobin in bidistilled water aqueous solution revealed a significant increase in b-sheet bands after 4 h of exposure, indicated with arrows in Figure 2, comparing exposed and unexposed spectra. These features can be attributed to the formation of aggregates [20][21][22] . ...
The effects of extremely low frequency electromagnetic field on the secondary structure of hemoglobin were investigated by means of Fourier Transform Infrared Spectroscopy. A decrease in intensity of the α-helix component in the amide I and amide II regions was observed after exposure of 4 h to a 50 Hz electromagnetic field at 1 mT. In addition, Fourier self deconvolution analysis was carried out on exposed and not-exposed spectra. A relative increase of the β-sheet feature in the amide I region was evidenced, showing that an unfolding process of the protein occurred after exposure to extremely low frequency electromagnetic field, suggesting the hypothesis of the formation of aggregates.
... Otherwise, alterations of proteins secondary structure in the amide I region produced by exposure to mobile phone microwaves was evidenced. [30][31][32][33][34] The result of an increase in β-sheet structure in meat's protein due to microwave oven heating should be taken into account. In fact, as has been shown extensively in the literature, proteins nutritive effectiveness, digestive behavior and utilization can be influenced by their α-helix and β-sheet ratios in the secondary structure, as high β-sheet to α-helix ratio can induce low access to gastrointestinal digestive enzymes, resulting in a low protein value and availability. ...
The effects of cooking by microwave oven on the secondary structure of lipid and protein contents in bovine ground beef were investigated in the midinfrared region by Fourier transform infrared (FTIR) spectroscopy to highlight the nonthermal effects of microwave oven heating. Samples of bovine ground beef were cooked in a conventional electric oven at the temperature of 175 degrees C for 15min and in a microwave oven at 800W for 11/2 min. Spectra analyses of bovine meat after cooking in the conventional oven evidenced a relevant increase in intensity of the carbonyl band at 1742cm(-1) and of the methylene group at 2921 and 2853cm(-1) that can be attributed to the Maillard reaction. In contrast, the increase in intensity of these bands after microwave oven heating was less than that which occurred after conventional cooking, showing that the temperature in ground beef meat samples during microwave heating was less than that induced by conventional heating. Spectral analysis in the amide I, II, and III regions showed that a significant increase in intensity occurred in the region from 1660 to 1675cm(-1) and around 1695, 1635, 1575, and 988cm(-1) after cooking by means of a microwave oven. These features, which can be attributed to beta-turns and beta-sheet structures, are characteristic of disorder processes in meat protein contents and increasing transition dipole coupling due to higher contents in aggregated beta-sheet structures. This result highlighted nonthermal effects of microwave oven heating in the protein's secondary structure.
... Recently it was proved that 50-Hz EMFs and MWs can also alter the secondary structure of proteins. [24][25][26][27][28][29][30] Myoglobin consists of a single protein chain with 153 amino acids and one heme group that stores oxygen in the muscle cells. Myoglobin has a stronger affinity for oxygen than hemoglobin, which enables the oxygen to shift from one to the other. ...
The effects of 3 hours' exposure to mobile phone microwaves at 1765MHz at the power density around 800 mW/m(2) on the secondary structure of myoglobin in D2O solution were investigated by Fourier transform infrared spectroscopy. A significant shift to lower frequencies of the amide I vibration was observed after exposure. Furthermore, a significant increasing of the -sheet components with respect to the -helix content after exposure was highlighted after applying Fourier self-deconvolution analysis in the amide I region. These results led to the conclusion that mobile phone microwaves induce unfolding of myoglobin and formation of aggregates.
... The analysis of the typical spectra represented in 3 showed that microwave oven cooking altered the amide I region. Otherwise, alterations of proteins secondary structure produced by exposure to mobile phone microwaves was evidenced [25][26][27][28]. Breast meat cooking in the microwave oven at the power level of 800 W for 95 sec produced low alterations in the amide I region, above all in the region from 1665 to 1695 cm -1 (see Figure 2(a)). ...
Deuterium Oxide (D2O) is an isotopic form of water which contains two atoms of deuterium (D) and one atom of oxygen. It is stable, non-radioactive and one of its characteristic properties is the shielding action against external stress agents. In particular, this effect has been highlighted comparing the changes of the characteristic vibration of two typical proteins (hemoglobin and bovine serum albumin) in H2O and in D2O solution after exposure to electromagnetic fields (EMFs) by means of Fourier Transform Infrared (FTIR) spectroscopy. The most relevant result which was observed after exposure of proteins in H2O solution to EMFs was the significant increasing in intensity of the Amide I band, which was already explained in previous studies assuming that proteins α-helix aligned along the direction of the applied EMF due to its large dipole moment. In contrast, hydrogen/deuterium (H/D) exchange induced a reduction of the increasing of Amide I vibration band. This result can be explained assuming that proteins Amide hydrogens exchange with solvent deuterium atoms, causing an increase in mass of the protein and a correlated increasing in inertia of the α-helix, reducing significantly the torque effect of the applied magnetic field. It means that H/D isotopic exchange can strengthen the hydrogen bond interaction providing that D2O can protect the secondary structure of a protein against the effects of non-ionizing electromagnetic radiation.
In this study, a correlation between cell channel α-helices displacement and the mitochondrial transmembrane potential after exposure of 3, 7, 15 and 24 h of neuronal-like cells to a uniform magnetic field at the intensity of 2 mT was shown. Fourier Transform Infrared (FTIR) Spectroscopy and fluorescence techniques were used to analyze the secondary structure of protein content and mitochondrial transmembrane potential, respectively. The main result of this study was represented by a significant inverse relation between the mitochondrial transmembrane potential and the intensity of the Amide I band that can be associated with time exposure. Given that mitochondrial transmembrane potential should be related to the gating state of voltagedependent
anion channel (VDAC) in mitochondrial membrane, this result could have a relevant
role in medicine. Indeed, VDAC's irregular behavior can be associated with several varieties of mitochondria-associated pathologies and various forms of cancer and neurodegeneration.
The aim of this study was to highlight the existence of a correlation between Maillard reaction
and protein aggregation in bovine meat as a function of power level and exposure time used by
microwave heating. The obtained results are compared with those of convective heating. For this,
Fourier Transform-Infrared Spectroscopy was used to analyze the effects of microwave heating on
different samples of bovine meat cooked in microwave ovens at three power levels of 700, 900
and 1100 W, and in conventional electric oven at the temperature of 170°C. An increase in
intensity of methylene vibration bands after microwave cooking at 700 W for 3 min was more
than that which occurred after microwave cooking at 900 and 1100 W for 2 min, showing that
Maillard reaction depends on exposure time to microwaves. Also, the β-sheet contents at 1695
and 1635 cm−1 in meat samples heated for 2 min by microwave oven increased with increase in
power level from 700 to 1100 W, showing that protein aggregation is strictly related to the power
level of microwave heating. This result showed that an extended exposure time to microwave
heating can significantly alter gastrointestinal digestive processes.
Proteins in aqueous solution are complex systems that are made of many interacting and non-interacting elements whose behavior can be predictable upon the application of non-linear models. The aim of this study was to show that this complex system behaves like a viscoelastic system under exposure to high frequency electromagnetics (HF-EMFs). To this aim, typical proteins in water solution were exposed for 3 h to a high frequency electromagnetic field at the power density of 1 W/m^2. Fourier Transform Infrared (FTIR) spectroscopy was used to study the response of proteins to exposure to HF-EMFs. Proteins α-helices aligned along the direction of the field and the integrated areas of proteins β-sheet content increased linearly as a function of proteins dipole moment. This result can be explained assuming that proteins in aqueous solution under HF-EMF behave like a viscoelastic system.
Background
The use of electromagnetic fields has been considered as adjuvant therapy for the treatment of cancer given that some clinical trials have shown that the irradiation of cancer cells with electromagnetic fields can slow down the disease progression.
Aims
We hypothesize that this effect could be amplified by irradiating tumor cells with electromagnetic fields having frequencies close to the natural resonant frequencies of membrane channels in tumor cells, in order to obtain a significant change of the ion flux across tumor cell membrane channels, inducing the largest harmful alteration in their cellular function.
Methods
Neuronal-like cells were used as a cell model and exposed for 6 h to electromagnetic fields at different frequencies (0, 50 Hz, 900 MHz) at the same intensity of 2 mT. The exposure system was represented by two Helmholtz coils driven by a power amplifier in current mode and an arbitrary function generator. FTIR spectroscopy was used to evaluate the results of the exposure.
Results
The results of this study showed that the Amide I vibration band increased in intensity with the increase of the frequency, leading us to assume that the displacement of the cell channels α-helices depends on the frequency of the applied electromagnetic fields.
Conclusion
This preliminary result leads us to plan future research aimed at searching for the natural frequencies of membrane channels in tumor cells using resonant electromagnetic fields in order to damage the cellular functions of tumor cells. Clinical trials are needed to confirm such a hypothesis derived from this physical study.
Purpose: To study the response of neuronal-like cells to an applied static or low frequency magnetic field.
Materials and Methods: Fourier Transform Infrared (FTIR) Spectroscopy was used to investigate the overall behavior of SH-SY5Y neuronal-like cells exposed to a static or 50 Hz magnetic fields at intensities up to 1 mT generated by two Helmholtz coils driven by DC or AC voltage. The Helmholtz coils were placed into an incubator in a 5% CO2/95% air humidified at 37 °C.
Results: A significant increasing in intensity of the Amide I band and of CH2 stretching vibrations in neuronal-like FTIR spectra appeared after 6 h exposure to static or 50 Hz magnetic fields.
Conclusions: These findings can be easily explained assuming that proteins α-helices and lipids contents in cellular membrane aligned towards the direction of the applied magnetic field after exposure, inducing an increasing of ions flux across cellular membrane channels after exposure to a magnetic field, changing cellular functions.
Background
This paper would be a starting point addressed to a methodology to minimize the effects on livings of man made Electromagnetic Fields (EMFs) pollution.
Methods
Given that previous literature highlighted that the most relevant EMFs effects on biological systems can be due to resonance phenomena between electromagnetic field and organic matter, it was proposed here an algorithm to obtain values of frequencies of an applied electromagnetic field far from resonant frequencies, depending on the natural frequencies and viscous damper of a biological system. These frequencies have been named non-resonant frequencies.
Results
The displacement of the α-helices in cellular membrane channels due to EMFs has been proposed as a relevant parameter for quantifying the result of the interaction between an applied EMF and organic matter, in order to find both the natural frequencies of a biological system and the resonant frequencies at which α-helices displacement should be maximum.
Conclusion
The non-resonant frequencies can be obtained using the algorithm proposed here.
In this study, we report the effects of static magnetic fields (SMFs) at 200 mT on different hemoglobin aqueous solutions, in the absence and in the presence of sucrose and trehalose, studied by FTIR spectroscopic techniques. Significant decrease in intensity of Amide I and Amide II vibration bands was observed after 6 h exposure for hemoglobin in bidistilled water solution. Also, it was observed that the decrease in intensity of the Amide I band was larger than the Amide II after exposure. This result can be explained assuming that an SMF induces increase of hydrogen bonding in hemoglobin in bidistilled water solution. In particular, the use of second-derivative analysis highlighted two absorption peaks at 1907 and 2022 cm(-1) that can be attributed to nitrogen monoxide vibration and antisymmetric stretch of azide ion bound, respectively. These vibrations increased significantly after exposure to the SMF (P < 0.01). This result can be explained assuming that exposure to an SMF induces the orientation of nitrogen monoxide and azide ion ligands toward the direction of the field. Finally, it was observed that the addition of sucrose and trehalose in hemoglobin aqueous solution inhibited such alterations, suggesting that bioprotective effectiveness of these disaccharides occurs after exposure to an SMF. Bioelectromagnetics. 2017;9999:XX-XX.© 2017 Wiley Periodicals, Inc.
Effects of exposure of 4 h to mobile phones microwaves at 1765 MHz at a power density around 940 mW/m(2) on four typical proteins (hemoglobin in H2 O solution, and myoglobin, bovine serum albumin, and lysozyme in D2 O solution) were studied by means of Fourier Transform Infrared spectroscopy and Fourier self-deconvolution analysis. Increase in intensity of parallel β-sheet component around 1635 cm(-1) was observed after exposure of hemoglobin, myoglobin, and bovine serum albumin, showing that a mechanism of unfolding occurred after exposure, whereas no appreciable change in the amide I region occurred after lysozyme exposure. In addition, a relationship between protein dipole moment and protein unfolding rate was demonstrated with a correlation coefficient r = 0.973 and 95% confidence interval. Bioelectromagnetics. 2016;9999:1-9. © 2016 Wiley Periodicals, Inc.
FTIR spectroscopy was used to investigate the effects of extremely low frequency (50 Hz) electromagnetic field and of microwaves at 900 MHz on the secondary structure of a typical protein, the lysozyme, evaluating the bioprotective effectiveness of trehalose. Lysozyme in D2O solution (60 mg/ml) was exposed to 50 Hz frequency electromagnetic field at 180 μT. The FTIR spectra indicated an increase of CH2 group at 1921 and 1853 cm−1 after 3 h of exposure. Such effect was not observed after the addition of trehalose (150 mg/mL) at the same exposure conditions. Lysozyme dissolved in D2O at the concentration of 100 mg/mL was exposed up to 4 h to 900 MHz mobile phone microwaves at 25 mA/m. A significant increase in intensity of the amide I vibration band in the secondary structure of the protein was observed after 4 h exposure to microwaves. This effect was inhibited by the presence of trehalose at the concentration of 150 mg/mL. Fourier self-deconvolution spectral analysis of lysozyme in D2O solution after exposure to microwaves revealed an increase in intensity of the conformational components of amide I mode, particularly of β-sheet and turn that can be attributed to disorder and unfolding processes of the protein.
The aim of this study was the investigation of static magnetic field effects on haemoglobin secondary structure and the bioprotective effectiveness of two disaccharides, sucrose and trehalose. Samples of haemoglobin aqueous solutions, in the absence and in the presence of sucrose and trehalose, were exposed to a uniform magnetic field at 200 mT, which is the exposure limit established by the ICNIRP recommendation for occupational exposure. Spectral analysis by FTIR spectroscopy after 3 and 7 h of exposure revealed a decrease in the amide A vibration band for haemoglobin in bi-distilled water solution. Analogue exposures did not produce any appreciable change of amide A for haemoglobin in sucrose and trehalose solutions. Otherwise, no relative increase of [Formula: see text]-sheet contents in amide I and II regions was detected for haemoglobin aqueous solutions, leading us to exclude the hypothesis that static magnetic fields can induce the formation of aggregates in the protein. In addition, a decrease in CH(3) stretching linkages occurred for haemoglobin in bi-distilled water solution after exposure, which was not observed for haemoglobin in sucrose and trehalose aqueous solutions, providing further evidence of a bioprotective compensatory mechanism of such disaccharides.
In this study the effects of microwaves on the secondary structure of three typical proteins have been investigated. A set of samples of lysozyme, bovine serum albumin and myoglobin in D2O solutions were exposed for 8 hours to mobile phone microwaves at 900 MHz at a magnetic field intensity around 16 mA/m. The relative effects on the secondary structure of the proteins were studied by means of Fourier Transform Infrared Spectroscopy. An increase of the amide I band intensity in the secondary structure of the proteins was observed after the microwaves exposure. Furthermore, a weak shift of the amide I mode of bovine serum albumin and a heavier shift of the amide I of myoglobin occurred after the exposure. In addition, a clear increasing of the β-sheet components with respect to the α-helix content was observed in the spectra of bovine serum albumin and myoglobin after the exposure, suggesting the hypothesis of the formation of aggregates.
The aim of this study is to provide measurements of the electromagnetic field due to the 'electrosmog' emitted by some home electronic devices in the range of microwaves frequencies. The enormous increase in the use of mobile telephony throughout the world, microwave ovens, cordless phones and other high frequency home utilities suggests accurate measures of microwaves power density emitted by such devices to check that the exposure limits suggested by the In-ternational Commission on Non-Ionizing Radiation Protection are not exceeded. Measurements were carried out by a Narda SRM 3000. Spectrum analysis mode was chosen as a preliminary analysis to quantify the frequencies intensities of electromagnetic waves. Time analysis was successively conducted to operate selective and continuous measurements at a fixed frequency, allowing temporal check of power density and the related electromagnetic field components emit-ted by high frequencies home electronic devices.
To investigate putative biological damage caused by GSM mobile phone frequencies by assessing electromagnetic fields during mobile phone working.
Neuron-like cells, obtained by retinoic-acid-induced differentiation of human neuroblastoma SH-SY5Y cells, were exposed for 2 h and 4 h to microwaves at 1800 MHz frequency bands.
Cell stress response was evaluated by MTT assay as well as changes in the heat shock protein expression (Hsp20, Hsp27 and Hsp70) and caspase-3 activity levels, as biomarkers of apoptotic pathway. Under our experimental conditions, neither cell viability nor Hsp27 expression nor caspase-3 activity was significantly changed. Interestingly, a significant decrease in Hsp20 expression was observed at both times of exposure, whereas Hsp70 levels were significantly increased only after 4 h exposure.
The modulation of the expression of Hsps in neuronal cells can be an early response to radiofrequency microwaves.
The following topics are discussed: a summary of dielectric theory; amino acids, peptides, proteins and DNA; bound water in biological systems; biological electrolytes; membranes and cells; tissues.
We investigated the effects of global system for mobile communication (GSM) microwave exposure on the permeability of the blood-brain barrier using a calibrated microwave exposure system in the 900 MHz band. Rats were restrained in a carousel of circularly arranged plastic tubes and sham-exposed or microwave irradiated for a duration of 4 h at specific brain absorption rates (SAR) ranging from 0.3 to 7.5 W/kg. The extravasation of proteins was assessed either at the end of exposure or 7 days later in three to five coronal brain slices by immunohistochemical staining of serum albumin. As a positive control two rats were subjected to cold injury. In the brains of freely moving control rats (n = 20) only one spot of extravasated serum albumin could be detected in one animal. In the sham-exposed control group (n = 20) three animals exhibited a total of 4 extravasations. In animals irradiated for 4 h at SAR of 0.3, 1.5 and 7.5 W/kg (n = 20 in each group) five out of the ten animals of each group killed at the end of the exposure showed 7, 6 and 14 extravasations, respectively. In the ten animals of each group killed 7 days after exposure, the total number of extravasations was 2, 0 and 1, respectively. The increase in serum albumin extravasations after microwave exposure reached significance only in the group exposed to the highest SAR of 7.5 W/kg but not at the lower intensities. Histological injury was not observed in any of the examined brains. Compared to other pathological conditions with increased blood-brain barrier permeability such as cold injury, the here observed serum albumin extravasations are very modest and, moreover, reversible. Microwave exposure in the frequency and intensity range of mobile telephony is unlikely to produce pathologically significant changes of the blood-brain barrier permeability.
Numerous organisms are capable of surviving more or less complete dehydration. A common feature in their biochemistry is that they accumulate large amounts of disaccharides, the most common of which are sucrose and trehalose. Over the past 20 years, we have provided evidence that these sugars stabilize membranes and proteins in the dry state, most likely by hydrogen bonding to polar residues in the dry macromolecular assemblages. This direct interaction results in maintenance of dry proteins and membranes in a physical state similar to that seen in the presence of excess water. An alternative viewpoint has been proposed, based on the fact that both sucrose and trehalose form glasses in the dry state. It has been suggested that glass formation (vitrification) is in itself sufficient to stabilize dry biomaterials. In this review we present evidence that, although vitrification is indeed required, it is not in itself sufficient. Instead, both direct interaction and vitrification are required. Special properties have often been claimed for trehalose in this regard. In fact, trehalose has been shown by many workers to be remarkably (and sometimes uniquely) effective in stabilizing dry or frozen biomolecules, cells, and tissues. Others have not observed any such special properties. We review evidence here showing that trehalose has a remarkably high glass-transition temperature (Tg). It is not anomalous in this regard because it lies at the end of a continuum of sugars with increasing Tg. However, it is unusual in that addition of small amounts of water does not depress Tg, as in other sugars. Instead, a dihydrate crystal of trehalose forms, thereby shielding the remaining glassy trehalose from effects of the added water. Thus under less than ideal conditions such as high humidity and temperature, trehalose does indeed have special properties, which may explain the stability and longevity of anhydrobiotes that contain it. Further, it makes this sugar useful in stabilization of biomolecules of use in human welfare.
The possible risks of radio-frequency electromagnetic fields for the human body is a growing concern for our society. We have previously shown that weak pulsed microwaves give rise to a significant leakage of albumin through the blood-brain barrier. In this study we investigated whether a pathologic leakage across the blood-brain barrier might be combined with damage to the neurons. Three groups each of eight rats were exposed for 2 hr to Global System for Mobile Communications (GSM) mobile phone electromagnetic fields of different strengths. We found highly significant (p< 0.002) evidence for neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of exposed rats.
X-ray diffraction (XRD) was used to investigate the structural and dynamical effects of microwave fields on tetragonal single crystals of hen egg-white lysozyme at a resolution of 2.0 A. Using a modified slab-line waveguide allows on-line XRD to be carried out while the protein crystal is exposed to well defined microwave fields. High microwave power levels mainly lead to increased, but largely recoverable, lattice defects owing to the evaporation of crystal water. At lower microwave power levels, the presence of the microwave field results in localized reproducible changes in the mean-square displacements (B factors). At particular sites, it is found that the B factors even decrease with increasing microwave power. Most of these effects can be explained by a comparison of the data obtained under microwave irradiation with data obtained at elevated temperature which simulate heating owing to microwave absorption by unbound crystal water. The data show no indication of large microwave-driven displacements of structural subunits in the protein that would be expected if microwaves were to be absorbed resonantly by protein vibrations. Rather, the observed changes in the atomic mean-square displacements suggest that if microwaves couple non-thermally to globular proteins at hydration levels at which they still function, their effect on protein dynamics and structure is very small.
Trehalose, a naturally occurring osmolyte, is known to be an exceptional stabilizer of proteins and helps retain the activity of enzymes in solution as well as in the freeze-dried state. To understand the mechanism of action of trehalose in detail, we have conducted a thorough investigation of its effect on the thermal stability in aqueous solutions of five well characterized proteins differing in their various physico-chemical properties. Among them, RNase A has been used as a model enzyme to investigate the effect of trehalose on the retention of enzymatic activity upon incubation at high temperatures. 2 m trehalose was observed to raise the transition temperature, Tm of RNase A by as much as 18 degrees C and Gibbs free energy by 4.8 kcal mol-1 at pH 2.5. There is a decrease in the heat capacity of protein denaturation (DeltaCp) in trehalose solutions for all the studied proteins. An increase in the DeltaG and a decrease in the DeltaCp values for all the proteins points toward a general mechanism of stabilization due to the elevation and broadening of the stability curve (DeltaG versus T). A direct correlation of the surface tension of trehalose solutions and the thermal stability of various proteins has been observed. Wyman linkage analysis indicates that at 1.5 m concentration 4-7 molecules of trehalose are excluded from the vicinity of protein molecules upon denaturation. We further show that an increase in the stability of proteins in the presence of trehalose depends upon the length of the polypeptide chain. The pH dependence data suggest that even though the charge status of a protein contributes significantly, trehalose can be expected to work as a universal stabilizer of protein conformation due to its exceptional effect on the structure and properties of solvent water compared with other sugars and polyols.
We collected inelastic neutron scattering (INS) spectra of homologous disaccharide (C12H22O11)/H2O mixtures at a very low temperature by using indirect geometry time-of-flight spectrometer TOSCA at the ISIS pulse neutron facility (DRAL, UK). The aim of this work is to investigate the vibrational behaviour of trehalose, maltose and sucrose/H2O mixtures with INS in order to characterize the structural changes induced by these disaccharides on the H2O hydrogen-bonded network. A higher degree of 'crystallinity' for the trehalose/H2O system is observed in the vibrational region corresponding to the ice bending modes. This feature could justify the better cryptobiotic action of trehalose compared with maltose and sucrose. On the other hand, the better bioprotective effectiveness could be explained by the higher destructuring effect of trehalose, emphasized by the analysis of the librational modes region.
A review is given of the dielectric properties of mammalian tissues for the frequency range 1 Hz to 10 GHz. Such information is of relevance to a number of medical diagnostic and therapeutic applications which involve the use of non-ionizing electromagnetic radiation, as well as to studies of the possible biological effects arising from exposure to electric and magnetic fields. Dielectric studies of tissues and biomolecules can also aid the further understanding of some biochemical and physiological processes. The dielectric properties of amino acids, proteins, biological electrolytes, cell membranes, tissue-bound water and of normal and cancerous tissues are discussed with the emphasis being directed at the underlying molecular and biophysical processes involved. Clinical aspects such as the hyperthermic treatment of cancer and the stimulation of bone healing are discussed also.
This chapter discusses the biological effects of microwaves. It is emphasized that an appropriate discussion of the experimental results with regard to nonthermal effects must frequently consider thermal effects as well. The amount of energy transfer from the radiation to the material varies slowly with frequency and is largely governed by the dielectric loss. Within reasonable limits, this loss is proportional to the intensity of the radiation. Nonthermal effects, on the other hand, occur in certain frequency regions only, and usually exhibit saturation at rather low intensity. As a consequence, nonthermal effects might be drowned by the thermal ones. This is in particular to be expected when the sign of the considered effect in the nonthermal region is opposite to that of the thermal effect. As an example, consider the reduction of the rate of growth of certain bacteria arising from irradiation at 73.6 Hz as discussed. Temperature increase, on the other hand, increases the rate of growth, thus canceling the nonthermal effect at sufficiently high intensity.
As a result of the regular arrangement of peptide dipoles in secondary
structure segments and the low effective dielectric constant in
Hydrophobic cores, the electrostatic energy of a protein is very
sensitive to the relative orientation of the segments. We provide here
evidence that the alignment of secondary structure dipoles is
significant in determining the three-dimensional structure of globular
proteins.
The protective effect of trehalose on biological membranes against freezing or dehydration has been the subject of many studies aimed to understand the reasons why some lower organisms, under stress conditions, synthesize trehalose. In this work we report the results of a study on Poly(Ethylene Oxide)/trehalose/water mixtures performed by Photon Correlation Spectroscopy. The chemical structure of the polymer, simpler than that of proteins and its helical conformation in water, constitute a useful starting point for understanding the more complex protein/trehalose/water interactions. In order to distinguish the different dynamics, trehalose and PEO have been studied separately in water, at different concentration and temperature values; then the ternary PEO/trehalose/water system has been investigated at different sugar amounts. The obtained findings support the “water-replacement” hypothesis, indicating that a direct polymer–trehalose interaction occurs. Furthermore, trehalose is shown to affect the swelling properties of the polymer with temperature, stabilizing its conformation. © 1999 American Institute of Physics.
Biological systems are expected to have a branch of longitudinal electric modes in a frequency region between 10¹¹ and 10¹² sec⁻¹. They are based on the dipolar properties of cell membranes; of certain bonds recurring in giant molecules (such as H bonds) and possibly on pockets of non-localized electrons. In Section 2 it is shown quit generally that if energy is supplied above a certain mean rate to such a branch, then a steady state will be reached in which a single mode of this branch is very strongly excited. The supplied energy is thus not completely thermalized but stored in a highly ordered fashion. This order expresses itself in long-range phase correlations; the phenomenon has considerable similarity with the low-temperature condensation of a Bose gas. General consequences and proposals of experiments are discussed in section 3.
Sodium-dependent high-affinity choline uptake was measured in various regions of the brains of rats irradiated for 45 min with either pulsed or continuous-wave low-level microwaves (2, 450 MHz; power density, 1 mW/cm2; average whole-body specific absorption rate, 0.6 W/kg). Pulsed microwave irradiation (2-μs pulses, 500 pulses/s) decreased choline uptake in the hippocampus and frontal cortex but had no significant effect on the hypothalamus, stria-turn, and inferior colliculus. Pretreatment with a narcotic antagonist (naloxone or naltrexone; 1 mg/kg i.p.) blocked the effect of pulsed microwaves on hippocampal choline uptake but did not significantly alter the effect on the frontal cortex. Irradiation with continuous-wave microwaves did not significantly affect choline uptake in the hippocampus, striatum, and hypothalamus but decreased the uptake in the frontal cortex. The effect on the frontal cortex was not altered by pretreatment with narcotic antagonist. These data suggest that exposure to low-level pulsed or continuous-wave microwaves leads to changes in cholinergic functions in the brain.
Effects of 10–30% (v/v) of dimethyl sulfoxide, glycerol, and ethylene glycol on the HOH bending vibration of water and the amide I bands of horse heart cytochrome c and chicken egg white lysozyme in 25 mM sodium phosphate buffer (pH 7.4) were examined at 20°C by Fourier transform infrared spectroscopy. The HOH bending mode of water was strongly affected by these cryoprotectant solvents. Increasing the concentration of cryosolvents from 0 to 30% shifts the water bending band maximum from 1645 to about 1650 cm−1. Second-derivative analysis reveals significant changes in conformation-sensitive amide I regions of lysozyme ascribed to α-helix (1657 cm−1), turn (1674 cm−1), and unordered (1646 cm−1) structures; each cryosolvent increases the intensity of the 1657 cm−1 band at the expense of bands at 1674 and 1646 cm−1. No changes in spectra deemed significant were observed for cytochrome c under the same conditions. There is no spectral evidence of structural randomization of proteins due to the presence of these cryosolvents. Cryosolvent-induced changes in secondary structure of proteins may result from changes in water structure which, in turn, perturb the structure of the protein and/or from direct interactions between cryosolvent and protein.
Synchrotron radiation is a bright source of infrared (IR) photons. It has been exploited in microscopy, where much smaller areas can be probed, with sizes close to the diffraction limit. The experiments have been performed at two beamlines, one at the National Synchrotron Light Source (USA) and one at SuperACO, LURE (France). The potentiality of this microanalytical synchrotron-based technique is particularly well documented in the study of individual cells: functional groups imaging representing biochemical changes have been obtained at various states of mitosis and apoptosis. The higher spatial resolution and spectral quality achieved allows investigating biological tissues in more detail. In this work, this is exemplified in the study of human hair and skin, where, in both cases, highly localized compounds have been evidenced in specific areas of the analyzed tissues: high lipid concentration inside the hair medulla, and inside the Stratum Corneum (SC) of skin. Moreover, the lineshape and frequency position of the CH2 stretching mode indicates a highly ordered phase extending over almost all the Stratum Corneum. The penetration pathway of an external agent has been also studied for both hair and skin. It is clear that synchrotron-based infrared microspectroscopy is an extremely valuable analytical tool when determining the spatially resolved chemical composition of biological and biomedical samples. In the future, the combination of infrared microspectroscopy with other synchrotron-based microscopic techniques, such as X-ray microscopy, at the same sample location is discussed.
Samples of bovine serum albumin in H(2)O and D(2)O solutions, in the absence or presence of trehalose, were exposed separately to a static magnetic field at 200 mT and to a 50 Hz electromagnetic field at 1.8 mT, studying the relative effects on the secondary structure of the protein by means of Fourier transform infrared spectroscopy. The spectra acquired in the mid-infrared region after 2 and 4 h of exposures to the static magnetic field showed a decrease in amide A and amide I band intensities for the protein in bidistilled aqueous solutions that was also evidenced after exposures to a 50 Hz electromagnetic field. These results led us to conclude that electromagnetic fields of low intensities can affect the C═O and C-N stretching vibrations and N-H plane bending of peptide linkages. Furthermore, mid-infrared spectra of bovine serum albumin in trehalose aqueous solutions were not significantly modified after the exposures, confirming the hypothesis of the possible bioprotective effectiveness of trehalose against electromagnetic fields.
The effects of extremely low frequency electromagnetic field on the protein structure of hemoglobin were investigated by means of Fourier transform infrared spectroscopy. Three samples of different hemoglobin aqueous solutions (also in the presence of sucrose and trehalose) were exposed to a 50 Hz electromagnetic field at 1 mT, and FTIR measurements were performed after 3 h of exposure. Quantitative spectral analysis revealed an evident decrease in amide A band intensity for hemoglobin in bidistilled water and sucrose aqueous solutions, but not for hemoglobin in trehalose aqueous solution. In addition a low relative increase of β-sheet in amide I region was detected for hemoglobin in both bidistilled water and sucrose aqueous solutions, whereas no appreciable changes were evidenced in the infrared spectra of hemoglobin in trehalose aqueous solutions. These results led us to conclude that a 50 Hz electromagnetic field can affect the N-H plane bending and C-N stretching vibrations of peptide linkages, suggesting compensatory mechanisms by means of environmental biochemical agents, such as evidenced by a protective effect of trehalose toward a low-frequency electromagnetic field.
Changes in the secondary structure and aggregation of chymotrypsinogen were investigated by infrared difference spectroscopy in conjunction with temperature and pressure tuning IR spectroscopy; both the amide I' band and side chain bands were studied. A prominent component of the amide I' band in the difference spectrum obtained upon cooling a chymotrypsinogen solution, or increasing the hydrostatic pressure, was observed in the region between 1627 and 1622 cm-1. Under denaturing conditions a white gel was formed, which is attributed to irreversible self-association or aggregation. This process was accompanied by the appearance of two new amide I' bands in the infrared spectrum of the protein: a very strong band at 1618 cm-1 and a weak band at 1685 cm-1. These bands are assigned to peptide segments with anti-parallel aligned beta-strands.
Some recent epidemiological studies have shown a positive association between cancer incidence and exposure to electromagnetic (EM) fields. Evidence from in vitro studies indicates that this effect could be due to synergistic interaction between EM fields and tumor promoters. However, no dose-response data related directly to carcinogenesis have been published. In this study, actively growing cultures of C3H/10T1/2 cells were exposed for 24 h to 2.45-GHz microwaves pulse-modulated at 120 Hz. Conditions of EM-field exposure were designed to simulate low-field exposures (specific absorption rate 0.1, 1, or 4.4 W/kg; the corresponding peak amplitudes were electric field 18, 56, or 120 V/m, magnetic field 0.09, 0.27, or 0.56 muT, respectively). In separate experiments, a 24-h EM-field exposure at 4.4 W/kg was preceded or followed by X irradiation at 0.5, 1, or 1.5 Gy. Cells were assayed for cell survival and neoplastic transformation with or without post-treatment administration of 0.1 micrograms/ml of 12-O-tetradecanoylphorbol-13-acetate (TPA) for the duration of the assay. The EM fields alone had no effect on cell survival or induction of neoplastic transformation. However, enhancement of transformation due to EM fields plus TPA was highly significant and ranged up to a level equivalent to that produced by 1.5 Gy of X rays. The frequency of neoplastic transformation was dependent on the level of EM exposure and was additive with doses of X rays given as a cocarcinogen.
Fourier-transform infrared spectroscopy (FT-IR) was applied to the study of tissue sections of human colorectal cancer. Pairs of tissue samples from colorectal cancer and histologically normal mucosa 5-10 cm away from the tumor were obtained from 11 patients who underwent partial colectomy. All cancer specimens displayed abnormal spectra compared with the corresponding normal tissues. These changes involved the phosphate and C-O stretching bands, the CH stretch region, and the pressure dependence of the CH2 bending and C = O stretching modes. Our findings indicate that in colonic malignant tissue, there are changes in the degree of hydrogen-bonding of (i) oxygen atoms of the backbone of nucleic acids (increased); (ii) OH groups of serine, tyrosine, and threonine residues (any or all of them) of cell proteins (decreased); and (iii) the C = O groups of the acyl chains of membrane lipids (increased). In addition, they indicate changes in the structure of proteins and membrane lipids (as judged by the changes in their ratio of methyl to methylene groups) and in the packing and the conformational structure of the methylene chains of membrane lipids. The cell(s) of the malignant colon tissues responsible for these spectral abnormalities is unknown. Cultured colon adenocarcinoma cell lines displayed similarly abnormal FT-IR spectra. The diagnostic potential of the observed changes is discussed.
Cultured V79 Chinese hamster cells were exposed to continuous radiation, frequency 7.7 GHz, power density 30 mW/cm2 for 15, 30, and 60 min. The parameters investigated were the incorporation of [3H]thymidine and the frequency of chromosome aberrations. Data obtained by 2 methods (the incorporation of [3H]thymidine into DNA and autoradiography) showed that the inhibition of [3H]thymidine incorporation took place by complete prevention of DNA from entering into the S phase. The normal rate of incorporation of [3H]thymidine was recovered within 1 generation cycle of V79 cells. Mutagenic tests performed concurrently showed that even DNA macromolecules were involved in the process. In comparison with the control samples there was a higher frequency of specific chromosome lesions in cells that had been irradiated. Results discussed in this study suggest that microwave radiation causes changes in the synthesis as well as in the structure of DNA molecules.
A field-strength-dependent hemolytic effect of continuous-wave radiofrequency (RF) exposure in vitro has been demonstrated. Erythrocytes in whole heparinized rabbit blood were hemolyzed by a 2-h exposure to 50- or 100-MHz RF fields at field strengths of greater than 4 V/cm. An effect of comparable magnitude resulted from exposure to 10-MHz RF at a field strength of 9 V/cm. Sample temperatures were maintained at 22.5 degrees +/- 0.2 degrees C. There was no apparent involvement of heating or temperature gradients, nor were there any RF exposure effects on cellular K+ or Na+ concentration, nor on pH. The mechanism of the hemolytic effect is not known. Since the percentage of lysed erythrocytes was less than 1% and there was an absence of effects on cellular cation concentrations, RF radiation may have irreversibly altered the plasma membrane permeability of a sensitive subpopulation of red cells (possibly aged cells) leading to osmotic lysis. RF radiation at these frequencies appears to affect red cells in a manner that is qualitatively and quantitatively different from microwave radiation.
This paper focuses on the genetic effects of microwaves from mobile communication frequencies (935.2 MHz) alone and in combination with a chemical DNA-damaging agent (mitomycin C). Three cytogenetic endpoints were investigated after in vitro exposure of human whole blood cells. These endpoints were the 'classical' chromosome aberration test, the sister chromatid exchange test and the alkaline comet assay. No direct cytogenetic effect was found. The combined exposure of the cells to the radiofrequency fields followed by their cultivation in the presence of mitomycin C revealed a very weak effect when compared to cells exposed to mitomycin C alone.
In order to reveal at a molecular level differences between fine-stranded and particulate gels, we present an Fourier transform infrared spectroscopic study of the thermal behavior of beta-lactoglobulin (beta-lg) in salt-free D(2)O solutions and low ionic strength at different pDs. Differences are found in the denaturation mechanism, in the unfolded state of the protein, in the aggregate formation, and in the strength of the intermolecular interactions. For fine-stranded gels (pD 2.8 and 7.8), heating induces the dissociation of the dimers into monomers. The protein undergoes extensive structural modifications before aggregation begins. Aggregation is characterized by the appearance of a new band attributed to intermolecular beta-sheets which is located in the 1613-1619 cm(-1) range. For particulate gels (pD 4.4 and 5.4), the protein structure is almost preserved up to 75-80 degrees C with no splitting of the dimers. The band characteristic of aggregation originates from the component initially located at 1623 cm(-1), suggesting that at the beginning of aggregation, globular beta-lg in the dimeric form associate to constitute oligomers with higher molecular mass. Aggregation may result in the association of globular slightly denatured dimers, leading to the formation of spherical particles rather than linear strands. The aggregation band is always located in the 1620-1623 cm(-1) range for particulate gels showing that hydrogen bonds are weaker for these aggregates than for fine-stranded ones. This has been related to a more extensive protein unfolding for fine-stranded gels that allows a closer alignment of the polypeptide chains, and then to the formation of much stronger hydrogen bonds. Small differences are also found in protein organization and in intermolecular hydrogen bond strength vs pD within the same type of gel. Protein conformation and protein-protein interactions in the gel state may be responsible of the specific macroscopic properties of each gel network. A coarse representation of the different modes of gelation is described.
It is shown that microwave irradiation can affect the kinetics of the folding process of some globular proteins, especially beta-lactoglobulin. At low temperature the folding from the cold denatured phase of the protein is enhanced, while at a higher temperature the denaturation of the protein from its folded state is enhanced. In the latter case, a negative temperature gradient is needed for the denaturation process, suggesting that the effects of the microwaves are nonthermal. This supports the notion that coherent topological excitations can exist in proteins. The application of microwaves hold promises for a wide range of biotechnological applications, such as protein synthesis, protein aggregation, etc., and may have implications for biological systems as well.
As part of a comprehensive investigation of the potential genotoxicity of radiofrequency (RF) signals emitted by cellular telephones, in vitro studies evaluated the induction of DNA and chromosomal damage in human blood leukocytes and lymphocytes, respectively. The signals were voice modulated 837 MHz produced by an analog signal generator or by a time division multiple access (TDMA) cellular telephone, 837 MHz generated by a code division multiple access (CDMA) cellular telephone (not voice modulated), and voice modulated 1909.8 MHz generated by a global system of mobile communication (GSM)-type personal communication systems (PCS) cellular telephone. DNA damage (strand breaks/alkali labile sites) was assessed in leukocytes using the alkaline (pH>13) single cell gel electrophoresis (SCG) assay. Chromosomal damage was evaluated in lymphocytes mitogenically stimulated to divide postexposure using the cytochalasin B-binucleate cell micronucleus assay. Cells were exposed at 37+/-1 degrees C, for 3 or 24 h at average specific absorption rates (SARs) of 1.0-10.0 W/kg. Exposure for either 3 or 24 h did not induce a significant increase in DNA damage in leukocytes, nor did exposure for 3 h induce a significant increase in micronucleated cells among lymphocytes. However, exposure to each of the four RF signal technologies for 24 h at an average SAR of 5.0 or 10.0 W/kg resulted in a significant and reproducible increase in the frequency of micronucleated lymphocytes. The magnitude of the response (approximately four fold) was independent of the technology, the presence or absence of voice modulation, and the frequency (837 vs. 1909.8 MHz). This research demonstrates that, under extended exposure conditions, RF signals at an average SAR of at least 5.0 W/kg are capable of inducing chromosomal damage in human lymphocytes.
The application of single-pass attenuated total reflection Fourier transform infrared (ATR-FT-IR) microscopy was investigated for secondary structure analysis of 15 representative proteins in H2O solution. This is the first reported application of single-pass ATR-FT-IR for protein analysis; thus, the method was validated using transmission FT-IR and multipass ATR-FT-IR as referee methods. The single-pass ATR-FT-IR technique was advantageous since the single-pass geometry permits rapid secondary structure analysis on small volumes of protein in H2O solution without the use of demountable thin path length sample cells. Moreover, the fact that H2O backgrounds were small allowed the simultaneous observation of the amide I-III, A, and B regions without having to perform H2O subtraction. A comparison of replicate protein spectra indicated that the single-pass ATR-FT-IR method yields more reproducible data than those acquired by transmission FT-IR. The observed trends for the amide I-III and A bands obtained by single-pass ATR-FT-IR agreed with those in the literature for conventional transmission FT-IR.
Radiofrequency ablation is a safe and effective treatment for small primary or secondary liver tumors. Development of new probes has allowed the use of radiofrequency ablation for ablation of tumors > 5 cm in the liver. We present a case of acute intravascular hemolysis and hemoglobinuria during radiofrequency ablation of a large 8-cm hepatocellular carcinoma via laparotomy. The hemolysis was recognized during the operation by change of urine color, and prompt management was initiated to prevent acute renal failure. Literature search revealed that radiofrequency ablation can induce hemolysis in experimental setting, but this is the first clinical report of acute hemolysis during radiofrequency ablation for liver tumors.
Non-thermal effects induced by exposure to microwave electromagnetic field (MW-EMF) at 1.95 MHz, a frequency used in mobile communication, have been observed on the refolding kinetics of the heme binding site in an intracellular protein: tuna myoglobin, starting from acidic conditions. We have selected myoglobin because it can be considered a good model to study protein interactions with MW-EMF for its well-known high-resolution crystallographic structure. Myoglobin solutions at pH 3.0 were subjected to 3 h exposure to microwave field (with a specific absorption rate of 51 +/- 1 mW/g); the heme site refolding has been followed by measuring the molecular absorption in the Soret spectral region and the data were fitted to a bi-exponential model. The kinetics of exposed samples appear to be slowered by MW-EMF action. Moreover, the tryptophanyl lifetime distribution of the exposed protein, as deduced by the analysis of the fluorescence emission decay from its single tryptophan, appears sharper if compared to non-exposed protein samples. This observation suggests that the presence of MW-EMF could affect the propensity of protein molecules to populate specific conformational substates among which myoglobin molecules fluctuate at acidic pH. Changes in the structural fluctuation caused by MW perturbation can affect differently the aggregation process that occurs competitively during the protein folding, so representing a potential risk for protein "misfolding." These data suggest that MW-EMF could have also biochemical and, consequently, biological effects on eukaryotic cells that are still under investigation.
In this study we investigated the effects of a pulsed radio frequency signal similar to the signal produced by global system for mobile communication telephones (900 MHz carrier, modulated at 217 Hz) on neurons of the avian brain. We found that such stimulation resulted in changes in the amount of neural activity by more than half of the brain cells. Most (76%) of the responding cells increased their rates of firing by an average 3.5-fold. The other responding cells exhibited a decrease in their rates of spontaneous activity Such responses indicate potential effects on humans using hand-held cellular phones.
Cultured human diploid fibroblasts and cultured rat granulosa cells were exposed to intermittent and continuous radiofrequency electromagnetic fields (RF-EMF) used in mobile phones, with different specific absorption rates (SAR) and different mobile-phone modulations. DNA strand breaks were determined by means of the alkaline and neutral comet assay. RF-EMF exposure (1800 MHz; SAR 1.2 or 2 W/kg; different modulations; during 4, 16 and 24h; intermittent 5 min on/10 min off or continuous wave) induced DNA single- and double-strand breaks. Effects occurred after 16 h exposure in both cell types and after different mobile-phone modulations. The intermittent exposure showed a stronger effect in the comet assay than continuous exposure. Therefore we conclude that the induced DNA damage cannot be based on thermal effects.
The aim of the present work is to link the bioprotective effectiveness to the dynamic properties of a class of homologous disaccharides, that is, trehalose, maltose and sucrose, and their mixtures in water. The findings obtained by elastic neutron scattering point out a harmonic-anharmonic transition for all the three disaccharide mixtures. Using a new operative definition of 'fragility', the different degrees of 'strength' of the investigated systems are determined. The links existing between the degree of fragility and the cryptoprotective action are also discussed.
Attention is drawn to a multitude of frequency-specific,
nonthermal bioeffects-induced in living systems by ultra-low-intensity
microwave radiation-the existence of which is not currently taken into
account in the formulation of the safety limits to which microwave
devices must conform. An attractive possibility of accounting for these
effects is in terms of Frohlich's coherent excitations involving
strongly excited macroscopic electric polarisation waves, which, on
quite general grounds, he predicted living systems to support-provided
they are sufficiently active metabolically-in consequence of the
prevalence therein of electric dipoles of various kinds. The therapeutic
exploitation of low-intensity microwave irradiation in Russia and the
Ukraine is noted, and attention drawn to some recent theoretical work
which suggests that water (a dipolar system in its own right) might
itself support mesoscopic coherent domains