Non‐Thermal effects in the microwave induced unfolding of proteins observed by chaperone binding

George, Doaa F.; Bilek, Marcela M.M.; McKenzie, David R.

doi:10.1002/bem.20382

Cited by 63 publications

(47 citation statements)

References 14 publications

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“…Non-thermal as well as thermal effects contribute to the efficacy of microwave ablation [3]. George et al reported unfolding of enzymes caused by direct electromagnetic impacts either on protein structure or on hydration-water [33]. Furthermore, Yu and Yao reported an inhibition of DNA synthesis and proliferation arrest in rabbit lens cells, which led to apoptotic changes.…”

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confidence: 99%

Microwave Ablation of Symptomatic Benign Thyroid Nodules: Energy Requirement per ml Volume Reduction

Korkusuz

Kohlhase

Gröner

et al. 2016

Fortschr Röntgenstr

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Zusammenfassung ▼Hintergrund: Mikrowellenablationen (MWA) stellen eine neuartige thermoablative Behandlung für benigne Schilddrüsenknoten dar. Ziel war es, die benötigte Energie pro ml Volumenreduktion zu benutzen, um die benötigte Energie für ein volume-of-interest (VOI) abschätzen zu können. Methode: 25 Patienten mit 25 Knoten (6 solide, 13 komplex und 6 zystisch) wurden durch MWA behandelt. Die übertragene Energie (E) wurde mit der Volumenveränderung (Δ V) nach 3 Monaten korreliert. Der Energiebedarf pro ml Volumenreduktion wurde durch E/Δ V bestimmt. Ergebnisse: MWA zeigte eine signifikante (p < 0,0001) Volumenreduktion (Δ V) im Mittel von 12,4 ± 13,0 ml (range: 1,5 -63,2 ml) und eine relative Reduktion von 52 ± 16 % (range: 22 -77 %). Es zeigte sich eine positive Korrelation zwischen E und Δ V (r = 0,82; p < 0,05). Die mittlere E/Δ V war 1,52 ± 1,08 (range: 0,4 -4,6) kJ/ml für alle Knoten und 2,30 ± 1,5 (0,9 -4,6); 1,5 ± 0,9 (0,4 -3,6); 0,75 ± 0,25 (0,4 -1,2) kJ/ml für solide, komplexe und zystische Knoten mit einer signifikanten Differenz der in E/Δ V zwischen soliden und zystischen Knoten (p < 0,03 Abstract ▼Purpose: Microwave ablation (MWA) represents a novel thermal ablative treatment of benign thyroid nodules. The aim was to determine the energy required per ml volume reduction in order to match the required energy to the volume-of-interest (VOI). Materials and Methods: 25 patients with 25 nodules (6 solid, 13 complex and 6 cystic) were treated by microwave ablation (MWA). The transmitted energy (E) was correlated with the volume change (Δ V) after 3 months. The energy required per ml volume reduction after 3 months was calculated by E/Δ V. Results: MWA resulted in a significant (p < 0.0001) volume reduction (Δ V) with a mean of 12.4 ± 13.0 ml (range: 1.5 -63.2 ml) and relative reduction of 52 ± 16 % (range: 22 -77 %). There was a positive correlation between E and Δ V (r = 0.82; p < 0.05). The mean E/Δ V was 1.52 ± 1.08 (range: 0.4 -4.6) kJ/ml for all nodules and 2.30 ± 1.5 (0.9 -4.6), 1.5 ± 0.9 (0.4 -3.6), 0.75 ± 0.25 (0.4 -1.2) kJ/ ml, respectively, for solid, complex and cystic nodules with a significant difference in E/Δ V for solid and cystic (p < 0.03). Conclusion: The energy required per volume depends on the nodule consistency. Solid nodules require more energy than cystic ones. The estimation of the energy needed per volume-of-interest as an additional parameter should help to avoid under-or overtreatment. Key Points:▶ The estimated required energy for a volumeof-interest depends on the nodule consistency ▶ In solid nodules a higher energy transmission than in cystic nodules is recommended ▶ The energy transmission as an additional marker to ultrasound is helpful for improving periprocedural monitoring This document was downloaded for personal use only. Unauthorized distribution is strictly prohibited.

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confidence: 99%

Microwave Ablation of Symptomatic Benign Thyroid Nodules: Energy Requirement per ml Volume Reduction

Korkusuz

Kohlhase

Gröner

et al. 2016

Fortschr Röntgenstr

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“…The nature of the debate surrounding this interaction has often referred to the existence of so-called specific microwave (MW) effects that are nonthermal in nature (4,10,13,17,20,28,29). Much has been published supporting the notion that a range of specific MW effects exist and can be identified in terms of their manifestations on cell physiology (2,4,10,13,27,28). For example, Dreyfuss and Chipley examined the effects of MW radiation (2.45 GHz) at sublethal temperatures on the metabolic activities of a range of enzymes expressed by the bacterium Staphylococcus aureus (10).…”

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Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli

Shamis

Taube

Mitik-Dineva

et al. 2011

Appl Environ Microbiol

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The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m 3 , and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control, E. coli cells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that the E. coli cells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposing E. coli cells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane.The effects of MW radiation on microorganisms have been studied and debated for more than half a century (3,4,10,12,17,20,28,29,35). The nature of the debate surrounding this interaction has often referred to the existence of so-called specific microwave (MW) effects that are nonthermal in nature (4,10,13,17,20,28,29). Much has been published supporting the notion that a range of specific MW effects exist and can be identified in terms of their manifestations on cell physiology (2,4,10,13,27,28). For example, Dreyfuss and Chipley examined the effects of MW radiation (2.45 GHz) at sublethal temperatures on the metabolic activities of a range of enzymes expressed by the bacterium Staphylococcus aureus (10). These results suggested that MW radiation affected S. aureus cells in a way that could not have been explained solely by thermaleffect theories. It has also been found that Burkholderia cepacia bacteria could be wholly inactivated using MW radiation at sublethal temperatures at a frequency of 20 GHz (2). Samarketu et al. (25) examined the effects of MW radiation at a frequency of 9.575 GHz on the physiological behavior of Cyanobacterium dolium (Anabaena dolium). The authors suggested that MW radiation nonthermally induced different biological effects by changing the protein structures by differentially partitioning the ions and altering the rates and/or directions of biochemical reactions (25)...

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“…Low-intensity 935 MHz radiation can affect microtubule proteins and suppress cell growth. Pacini et al (40) ) for up to 100 h. However, two independent groups of investigators demonstrated the capability of lowpower UHF radiation to induce reversible changes to cell protein structure, affect beta-lactoglobulin conformational changes, and stimulate the unfolding of citrate synthase (42)(43)(44). In addition, Leszczynski et al (45) found that mobile phone radiation changes the phosphorylation status of the heat shock protein-27, one of the stress family proteins.…”

Section: Cellular Biomarkers Of Rf/mw Exposurementioning

confidence: 99%

Non-Thermal Biomarkers of Exposure to Radiofrequency/Microwave Radiation

Trošić¹,

Pavičić²,

Marjanović³

et al. 2012

Archives of Industrial Hygiene and Toxicology

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This article gives a review or several hypotheses on the biological effects of non-thermal radiofrequency/ microwave (RF/MW) radiation and discusses our own fi ndings from animal and in vitro studies performed over the last decade. We have found that RF/MW radiation disturbs cell proliferation and leads to cell differentiation in the bone marrow, which is refl ected in the peripheral blood of rats. Repeated RF/MW radiation can also temporarily disrupt melatonin turnover. The observed changes seem to be a sign of adaptation to stress caused by irradiation rather than of malfunction. The article looks further into the basic mechanisms of RF/MW biological action, including cell growth parameters, colony-forming ability, viability, and the polar and apolar protein cytoskeleton structures. The observed reversible cell changes signifi cantly obstructed cell growth. In contrast to the apolar intermediate proteins, the intracellular polar microtubule and actin fi bres were damaged by radiation in a time-dependent manner. These signifi cantly altered parameters can be considered as the biomarkers of exposure. Future research should combine dosimetry, experimental studies, and epidemiological data.

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Non‐Thermal effects in the microwave induced unfolding of proteins observed by chaperone binding

Cited by 63 publications

References 14 publications

Microwave Ablation of Symptomatic Benign Thyroid Nodules: Energy Requirement per ml Volume Reduction

Microwave Ablation of Symptomatic Benign Thyroid Nodules: Energy Requirement per ml Volume Reduction

Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli

Non-Thermal Biomarkers of Exposure to Radiofrequency/Microwave Radiation

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