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1.
Adv Exp Med Biol ; 1232: 263-269, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893419

RESUMO

Ahematological and morphological investigation was made of the effects of pulsed magnetic field (PMF) stimulus on oxidized erythrocyte membrane using the smear method and spectroscopic measurement. Tert-butyl hydroperoxide (tBHP) was used for oxidative stress, and verapamil was used as reduction agent on red blood cells (RBCs). Our PMF stimulator system was designed to generate a maximum intensity of 0.27 T at a transition time of 0.102 ms. The morphology of oxidized RBCs, and oxidative stressed RBCs after treatment with a reducing agent were observed before and after PMF. Light absorbance of hemoglobin (Hb) was measured in the membrane as well as plasma, through hemolysis of RBCs. Absorbance for a sample exposed to PMF before the oxidation treatment was lower than that for a sample not exposed to PMF in the plasma. This means that PMF plays a role in preventing hemolysis of erythrocyte membrane from oxidative stress. Our results were confirmed using an osmotic fragility test. Hemolysis in the case of PMF treatment is 28% lower than that of non-PMF treatment. As a result, PMF stimulus is proposed to achieve an improvement of RBCs aggregation and prevent RBCs from oxidative stress, and could be used in various clinical fields related to peripheral vascular diseases. For further clinical application, we need to optimize PMF intensity and stimulated duration.


Assuntos
Eritrócitos , Hemólise , Campos Magnéticos , Estresse Oxidativo , Membrana Eritrocítica , Eritrócitos/patologia , Eritrócitos/efeitos da radiação , Hemólise/efeitos da radiação , Humanos , Campos Magnéticos/efeitos adversos
2.
Bioelectromagnetics ; 41(1): 41-51, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31736106

RESUMO

Magnetic fields (MFs) have been used as an external stimulus to increase cell proliferation in chondrocytes and extracellular matrix (ECM) synthesis of articular cartilage. However, previously published studies have not shown that MFs are homogeneous through cell culture systems. In addition, variables such as stimulation times and MF intensities have not been standardized to obtain the best cellular proliferative rate or an increase in molecular synthesis of ECM. In this work, a stimulation device, which produces homogeneous MFs to stimulate cell culture surfaces was designed and manufactured using a computational model. Furthermore, an in vitro culture of primary rat chondrocytes was established and stimulated with two MF schemes to measure both proliferation and ECM synthesis. The best proliferation rate was obtained with an MF of 2 mT applied for 3 h, every 6 h for 8 days. In addition, the increase in the synthesis of glycosaminoglycans was statistically significant when cells were stimulated with an MF of 2 mT applied for 5 h, every 6 h for 8 days. These findings suggest that a stimulation with MFs is a promising tool that could be used to improve in vitro treatments such as autologous chondrocyte implantation, either to increase cell proliferation or stimulate molecular synthesis. Bioelectromagnetics. 2020;41:41-51 © 2019 Bioelectromagnetics Society.


Assuntos
Cartilagem Articular/metabolismo , Condrócitos/citologia , Condrócitos/metabolismo , Matriz Extracelular/metabolismo , Campos Magnéticos/efeitos adversos , Animais , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Células Imobilizadas , Simulação por Computador , Glicosaminoglicanos/química , Ratos , Ratos Wistar , Propriedades de Superfície , Temperatura Ambiente , Fatores de Tempo
3.
Bioelectromagnetics ; 41(1): 52-62, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31802523

RESUMO

We established three types of thrombosis models to explore the effects of the static magnetic field (SMF) on thrombosis in rats and mice with three different MF intensities. In the carrageenan-induced thrombosis model in rats, the SMF treatments reduced the black tail length of rats, extracorporeal thrombus, and the mass of wet and dry thrombus, and improved the coagulation index value. In FeCl3 -induced arterial thrombosis model in rats, the SMF treatment showed some anti-thrombotic effects. More specifically, the SMF treatment affected rodent blood pressure, plasma plasminogen activator inhibitor, tissue-type plasminogen activator, thrombus mass, and thrombus protein content. In the adrenaline-induced thrombosis model in mice, the SMF treatment had certain effects on the diameter and blood flow velocity of mouse auricle microcirculation in fine veins and arteries. Overall, the highest MF intensities we tested, 20-150 mT, showed a trend of anti-thrombotic effect, indicating that the moderate-intensity SMF might serve as a potential treatment for clot-related diseases in the future. Bioelectromagnetics. 2020;41:52-62 © 2019 Bioelectromagnetics Society.


Assuntos
Campos Magnéticos/efeitos adversos , Trombose/prevenção & controle , Animais , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Carragenina/metabolismo , Epinefrina/metabolismo , Frequência Cardíaca , Compostos de Ferro/metabolismo , Masculino , Camundongos , Microcirculação , Ativadores de Plasminogênio/metabolismo , Ratos , Ratos Sprague-Dawley , Ativador de Plasminogênio Tecidual/metabolismo
4.
Bioelectromagnetics ; 41(1): 34-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31742723

RESUMO

Buildings with indoor transformer stations may serve as a basis for improved epidemiological studies on the health effects of extremely low-frequency magnetic fields (ELF MFs). Previous studies have shown that ELF MF exposure can be adequately assessed based on the fact that MF levels are high in apartments directly above transformers. In this paper, we describe the creation of a registry of Finnish residential buildings with built-in transformer stations and discuss its usability in epidemiological studies. Information obtained from electric utilities and building blueprints were used to identify 677 buildings in which an apartment was located above or adjacent to a transformer station. All apartments in these buildings were classified into exposure categories based on their location in relation to the transformer. Residential histories of these buildings were obtained from the Population Register Centre. Out of the 287,668 individuals who have resided in the buildings, 9,126 of them have resided in an apartment located directly above a transformer station. All information was collected without contacting residents, thus avoiding selection bias. The registry can be linked with data from high-quality nationwide registries to confirm or challenge the reported associations of ELF MF exposure and diseases such as cancer, miscarriage, and Alzheimer's disease. Bioelectromagnetics. 2020;41:34-40 © 2019 Bioelectromagnetics Society.


Assuntos
Fontes de Energia Elétrica/efeitos adversos , Estudos Epidemiológicos , Campos Magnéticos/efeitos adversos , Monitoramento de Radiação/estatística & dados numéricos , Eletricidade , Habitação , Humanos , Doses de Radiação , Medição de Risco/métodos , Fatores de Risco
5.
Braz J Cardiovasc Surg ; 34(6): 674-679, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31364342

RESUMO

OBJECTIVE: To study the response of myocardial ischemia/reperfusion injury (MI/RI) in rats to simulated geomagnetic activity. METHODS: In a simulated strong geomagnetic outbreak, the MI/RI rat models were radiated, and their area of myocardial infarction, hemodynamic parameters, creatine kinase (CK), lactate dehydrogenase (LDH), melatonin, and troponin I values were measured after a 24-hour intervention. RESULTS: Our analysis indicates that the concentrations of troponin I in the geomagnetic shielding+operation group were lower than in the radiation+operation group (P<0.05), the concentrations of melatonin in the shielding+operation group and normal+operation group were higher than in the radiation + operation group (P<0.01), and the concentrations of CK in the shielding + operation group were lower than in the radiation + operation group and normal + operation group (P<0.05). Left ventricular developed pressure (LVDP) and ± dP/dtmax in the radiation+operation group were lower than in the shielding + operation group and normal+operation group (P<0.01). Left ventricular end-diastolic pressure (LEVDP) in the shielding + operation group was higher than in the normal + operation group (P<0.05). There was no significant difference in area of myocardial infarction and LDH between the shielding + operation group and the radiation + operation group. CONCLUSION: Our data suggest that geomagnetic activity is important in regulating myocardial reperfusion injury. The geomagnetic shielding has a protective effect on myocardial injury, and the geomagnetic radiation is a risk factor for aggravating the cardiovascular and cerebrovascular diseases.


Assuntos
Campos Magnéticos/efeitos adversos , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Animais , Creatina Quinase , Modelos Animais de Doenças , Hemodinâmica , Masculino , Ratos , Ratos Sprague-Dawley
6.
Artigo em Inglês | MEDLINE | ID: mdl-31591344

RESUMO

Extremely low frequency (ELF) magnetic field (MF) exposure in electric vehicles (EVs) has raised public concern for human health. There have been many studies evaluating magnetic field values in these vehicles. However, there has been no report on the temporal variation of the magnetic field in the cabin . This is the first study on the long-term monitoring of actual MFs in EVs. In the study, we measured the magnetic flux density (B) in three shared vehicles over a period of two years. The measurements were performed at the front and rear seats during acceleration and constant-speed driving modes. We found that the B amplitudes and the spectral components could be modified by replacing the components and the hubs, while regular checks or maintenance did not influence the B values in the vehicle. This observation highlights the necessity of regularly monitoring ELF MF in EVs, especially after major repairs or accidents, to protect car users from potentially excessive ELF MF exposure. These results should be considered in updates of the measurement standards. The ELF MF effect should also be taken into consideration in relevant epidemiological studies.


Assuntos
Automóveis , Fontes de Energia Elétrica/efeitos adversos , Eletricidade , Exposição Ambiental/efeitos adversos , Exposição Ambiental/estatística & dados numéricos , Campos Magnéticos/efeitos adversos , Automóveis/normas , Monitoramento Ambiental , Humanos
7.
Artigo em Inglês | MEDLINE | ID: mdl-31547412

RESUMO

Human neuropsychological reactions and brain activities when driving electric vehicles (EVs) are considered as an issue for traffic and public safety purposes; this paper examined the effect of the static magnetic field (SMF) derived from EVs. A lane change task was adopted to evaluate the driving performance; and the driving reaction time test and the reaction time test were adopted to evaluate the variation of the neuro-psychological cognitive functions. Both the sham and the real exposure conditions were performed with a 350 µT localized SMF in this study; 17 student subjects were enrolled in this single-blind experiment. Electroencephalographs (EEGs) of the subjects were adopted and recorded during the experiment as an indicator of the brain activity for the variations of the driving performance and of the cognitive functions. Results of this study have indicated that the impact of the given SMF on both the human driving performance and the cognitive functions are not considerable; and that there is a correlation between beta sub-band of the EEGs and the human reaction time in the analysis.


Assuntos
Condução de Veículo/estatística & dados numéricos , Automóveis/classificação , Cognição/efeitos da radiação , Campos Magnéticos/efeitos adversos , Tempo de Reação/efeitos da radiação , Feminino , Hong Kong , Humanos , Masculino , Método Simples-Cego , Adulto Jovem
8.
Bioelectromagnetics ; 40(8): 569-577, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31373404

RESUMO

This study aims to assess the levels of extremely low frequency magnetic fields (ELF-MF) emitted from portable hand-held fans (HHFs) and their principal frequency and to identify factors influencing these levels. We collected a total of eleven models of HHF and monitored the ELF-MF as a function of fan speed and distance from the fan. EMDEX II was used to monitor the ELF-MF. An SMP2 EMF-meter equipped with a P400 field probe was used to determine the levels of ELF-MF and the frequency spectrum. Ten of the fans, excluding only one bladeless-fan model, emitted a high level of ELF-MF near the source of the HHF direct-current motor. The maximum measured level of ELF-MF ranged from 14.07 to 218.7 µT. All measurements of the ELF-MF taken within 10 cm from the HHFs showed values higher than 1.0 µT. ELF-MF levels were found to decrease markedly with distance, regardless of the HHF product. The level of ELF-MF rose noticeably with increased fan speed. The speed of and distance from the HHF significantly influenced the level of ELF-MF. All principal frequencies ranged from 1 to 300 Hz, which falls in the typical range of ELF. Bioelectromagnetics. 2019;40:569-577. © 2019 Bioelectromagnetics Society.


Assuntos
Equipamentos e Provisões Elétricas/efeitos adversos , Campos Magnéticos/efeitos adversos , Eletricidade , Humanos , Exposição Ocupacional , República da Coreia
9.
Microsc Res Tech ; 82(11): 1878-1883, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31368622

RESUMO

The aim of this article is to compare the effects of 1.5 T and 3 T MRI on microleakage of amalgam restorations. A total of 90 extracted molar teeth were used in this study. Amalgam was used to restore standard Class V preparations (5 × 3 × 2 mm). Following the restoration, the teeth were divided into three groups according to magnetic resonance imaging (MRI) protocol (Group I: Control, Group II: 1.5 T MRI, and Group III: 3 T MRI). A total of 6,000 thermal cycles at 5°C-55°C were applied on all samples. Microleakage values were measured in millimeters using the ImageJ program. Microleakage values were higher in the gingival region compared to the occlusal region in all groups and the differences were statistically significant (p < .05). Microleakage values were not statistically different among the groups in the occlusal region (p > .05), while there were statistically significant differences among the groups with respect to microleakage values in the gingival region (p < .01). The highest mean microleakage amount in the gingival region was measured in Group III (1.192 ± 0.941 mm). This was followed by Group II (0.519 ± 0.813 mm) and Group I (0.347 ± 0.726 mm), respectively. Within the limitations of this in vitro study, we observed that higher microleakage values in amalgam restored teeth in which were exposed to MRI procedure. We also found that the teeth exposed to the stronger magnetic field showed higher microleakage amount.


Assuntos
Amálgama Dentário/efeitos da radiação , Infiltração Dentária , Campos Magnéticos/efeitos adversos , Imagem por Ressonância Magnética/efeitos adversos , Dente Molar/efeitos da radiação , Resinas Compostas/efeitos da radiação , Preparo da Cavidade Dentária , Restauração Dentária Permanente , Adesivos Dentinários/efeitos da radiação , Humanos
10.
Electromagn Biol Med ; 38(4): 279-286, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31303067

RESUMO

The long-term exposure of OF1 mice to an extremely low frequency magnetic field (ELF-MF; 50 Hz, 15 µT [rms]) has been associated with the appearance of leukaemia. Neoplasms are usually accompanied by changes in haemostatic processes but reports on changes in blood coagulation following exposure to an ELF-MF are scarce and rather fragmentary. The aim of the present work was to determine whether any global or partial coagulation variables are modified after such long-term exposure. A parental generation of six week-old OF1 mice was exposed to an artificial ELF-MF for 14 weeks. Mating was then allowed, and the resulting filial generation raised until the age of 31-35 weeks within the same ELF-MF. Control animals were subjected only to the magnetic field of the Earth. Whole blood samples were extracted from the anesthetised filial generation of mice by cardiac puncture. White blood cells (WBC) were counted, the activated partial thromboplastin time (APTT) and prothrombin time (PT) determined, and plasma fibrinogen, reptilase time (RT), and factor VIII activity examined. The similarity between the results for the present control animals and those recorded in the literature for human blood render OF1 mice a suitable study model. The differences in the studied coagulation variables were largely owed simply to sex. However, the females showed a very significant shortening of the PT time associated with ELF-MF exposure. Exposure also caused significant increases in the female APTT and RT values, and in general reduced the differences between the sexes.


Assuntos
Coagulação Sanguínea , Campos Magnéticos/efeitos adversos , Animais , Feminino , Fibrinogênio/metabolismo , Masculino , Camundongos , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Fatores de Tempo
11.
Bioelectromagnetics ; 40(7): 512-521, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31254292

RESUMO

Time-varying magnetic field gradients involved in magnetic resonance examinations can damage implanted electronic systems. The quantity related to this side effect is the gradient slew rate, which is usually not directly available on magnetic resonance console. The present study proposes a low-cost approach in slew rate assessment, which is useful in risks versus benefits evaluation as well as in sequences optimization. The experimental method is based on an analog circuit, which senses the output voltage of the scanner waveform generator. This allows taking easy and reliable slew rate measurements, even during clinical examinations on patients. Whereas previous studies required managing a considerable amount of data, the present work addresses only the maximal slew rate of any clinical sequence. Experimental results show that the smooth gradient mode, selectable on the two scanners examined, is very effective in patient safety improvement. In particular, it reduces slew rate values in the range from 52.4 up to 132.4 T m-1 s-1 , i.e. far below the interval 216-346 T m-1 s-1 , indicated as slew rate tolerance limit of modern implanted electronic devices. Bioelectromagnetics. 2019;40:512-521. © 2019 Bioelectromagnetics Society.


Assuntos
Simulação por Computador , Campos Magnéticos/efeitos adversos , Próteses e Implantes , Desenho de Equipamento , Segurança de Equipamentos , Humanos , Imagem por Ressonância Magnética , Próteses e Implantes/economia
12.
Neuroimage ; 199: 273-280, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158482

RESUMO

People are exposed to various magnetic fields, including the high static/steady magnetic field (SMF) of MRI, which has been increased to 9.4 T in preclinical investigations. However, relevant safety studies about high SMF are deficient. Here we examined whether 3.5-23.0 T SMF exposure for 2 h has severe long-term effects on mice using 112 C57BL/6J mice. The food/water consumption, blood glucose levels, blood routine, blood biochemistry, as well as organ weight and HE stains were all examined. The food consumption and body weight were slightly decreased for 23.0 T-exposed mice (14.6%, P < 0.01, and 1.75-5.57%, P < 0.05, respectively), but not the other groups. While total bilirubin (TBIL), white blood cells, platelet and lymphocyte numbers were affected by some magnetic conditions, most of them were still within normal reference range. Although 13.5 T magnetic fields with the highest gradient (117.2 T/m) caused spleen weight increase, the blood count and biochemistry results were still within the control reference range. Moreover, the highest field 23.0 T with no gradient did not cause organ weight or blood biochemistry abnormality, which indicates that field gradient is a key parameter. Collectively, these data suggest 3.5-23.0 T static magnetic field exposure for 2 h do not have severe long-term effects on mice.


Assuntos
Campos Magnéticos/efeitos adversos , Imagem por Ressonância Magnética/efeitos adversos , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
13.
Life Sci Space Res (Amst) ; 21: 83-88, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31101158

RESUMO

The capability of Daphnia magna to adapt to artificial low-frequency magnetic fields via a maternal effect has been demonstrated previously. The current study assessed the possibility of a maternal effect in response to simulated natural geomagnetic fluctuations. D. magna lines were exposed to simulated geomagnetic storms for two, five, and eight sequential generations. Evaluations were conducted on the 3rd, 6th, and 9th generations of daphnids from experimental and control lines in order to determine the period required for the formation of an adaptive maternal effect. The evaluations showed that larger offspring were produced when maturation and reproduction occurred under the same conditions as those in which the Daphnia had lived in for generations. These observations suggest a manifestation of an adaptive maternal effect occurs in response to long-term exposure to simulated geomagnetic storms. Ecological relevance of geomagnetic storms to natural populations of daphnids is discussed.


Assuntos
Daphnia/fisiologia , Longevidade , Campos Magnéticos/efeitos adversos , Reprodução , Animais , Animais Recém-Nascidos , Daphnia/crescimento & desenvolvimento , Daphnia/efeitos da radiação , Feminino
14.
Bioelectromagnetics ; 40(4): 250-259, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30945762

RESUMO

Artificial light and power frequency magnetic fields are ubiquitous in the built environment. Light is a potent zeitgeber but it is unclear whether power frequency magnetic fields can influence circadian rhythm control. To study this possibility, 8-12-week-old male C57BL/6J mice were exposed for 30 min starting at zeitgeber time 14 (ZT14, 2 h into the dark period of the day) to 50 Hz magnetic fields at 580 µT using a pair of Helmholtz coils and/or a blue LED light at 700 lux or neither. Our experiments revealed an acute adrenal response to blue light, in terms of increased adrenal per1 gene expression, increased serum corticosterone levels, increased time spent sleeping, and decreased locomotor activity (in all cases, P < 0.0001) compared to an unexposed control group. There appeared to be no modulating effect of the magnetic fields on the response to light, and there was also no effect of the magnetic fields alone (in both cases, P > 0.05) except for a decrease in locomotor activity (P < 0.03). Gene expression of the cryptochromes cry1 and cry2 in the adrenals, liver, and hippocampus was also not affected by exposures (in all cases, P > 0.05). In conclusion, these results suggest that 50 Hz magnetic fields do not significantly affect the acute light response to a degree that can be detected in the adrenal response. Bioelectromagnetics. 2019;9999:XX-XX. © 2019 Bioelectromagnetics Society.


Assuntos
Ritmo Circadiano , Campos Magnéticos/efeitos adversos , Animais , Corticosterona/metabolismo , Criptocromos/genética , Criptocromos/metabolismo , Regulação da Expressão Gênica , Luz , Masculino , Camundongos Endogâmicos C57BL , Atividade Motora , Especificidade de Órgãos , Proteínas Circadianas Period/metabolismo , Sono
15.
J Environ Radioact ; 204: 35-41, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30959328

RESUMO

With the increasing density of high voltage transmission systems, the potential risks and hazards of environmental electric fields (EFs) generated by these systems to surrounding organisms is becoming a source of public concern. To evaluate the effect of environmental EFs on plants, we used soybean as a model and systematically evaluated the effect of continuous exposure to different intensities (0 kV/m, 2 kV/m, and 10 kV/m) of power frequency EFs on agronomic characters, yield, nutrient contents, protective enzyme activities, and gene transcription. We found that the effects on soybean were more pronounced when plants were exposed to EF during development (especially at the seedling stage) than when they were exposed at maturity. The functional leaf number, stem diameter, plant dry weight, and pod number were largely unaffected by EF, while the germination rate and protective enzyme activities increased with increasing EF intensity. In plants exposed to low-intensity EF (2 kV/m), some agronomic characters, including chlorophyll content, plant height, and bean dry weight, as well as the soluble sugar and total protein contents, were significantly higher than those of plants exposed to high-intensity EF (10 kV/m) and control plants (0 kV/m). Through transcriptome analysis, we found that 2,977 genes were significantly up-regulated and 1,462 genes were down-regulated when plants were exposed to EF. These differentially expressed genes mainly encode ribosome proteins and related enzymes involved in carbon metabolism pathway, providing a novel perspective for understanding molecular mechanisms underpinning the responses to EF stress in soybean.


Assuntos
Fontes de Energia Elétrica/efeitos adversos , Germinação/efeitos da radiação , Centrais Elétricas , Soja/efeitos da radiação , Transcriptoma/efeitos da radiação , Condutividade Elétrica , Campos Magnéticos/efeitos adversos , Soja/enzimologia , Soja/genética , Soja/fisiologia
16.
Bioelectromagnetics ; 40(3): 160-169, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30875092

RESUMO

Although the likelihood of exposure to leaking intermediate frequency magnetic fields (MFs) from electronic devices, such as induction-heating and wireless power transfer systems, has increased, biological data assessing the health risks associated with human exposure remain insufficient. We examined the carcinogenicity of a 20 kHz MF, a typical frequency produced by induction-heating cookers, using a transgenic rasH2 mouse model. Twenty-five male and female CByB6F1-Tg(HRAS)2Jic mice were exposed to a 0.20 mT, 20 kHz MF (22 h/day) or sham-exposed for 26 weeks. As a positive control, 10 male and female rasH2 mice from the same batch were administered a single intraperitoneal injection of 75 mg/kg N-methyl-N-nitrosourea. A blinded histopathological evaluation was performed, and the same experiments were conducted twice, independently, to confirm the reproducibility of the results. Histopathological examination revealed that spontaneous neoplastic lesions, such as splenic hemangiosarcomas and gastric squamous cell papillomas, were less (1-3 per group) in the MF- and sham-exposed groups. The frequency of the neoplastic lesions was not significantly different between the groups. Eight to ten mice in each positive-control group exhibited malignant lymphoma. The outcomes were consistent between duplicated experiments, which indicates lack of carcinogenicity of 20 kHz MF in the rasH2 mouse model. Bioelectromagnetics. © 2019 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.


Assuntos
Carcinogênese , Campos Magnéticos/efeitos adversos , Animais , Peso Corporal , Feminino , Masculino , Camundongos , Neoplasias/patologia , Radiometria , Análise de Sobrevida , Fatores de Tempo
17.
Bioelectromagnetics ; 40(3): 170-179, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30913307

RESUMO

In this study, an innovative approach that combines Principal Component Analysis (PCA) and Gaussian process regression (Kriging method), never used before in the assessment of human exposure to electromagnetic fields (EMF), was applied to build space-dependent surrogate models of the 3D spatial distribution of the electric field induced in central nervous system (CNS) of children of different ages exposed to uniform magnetic field at 50 Hz of 200 µT of amplitude with uncertain orientation. The 3D surrogate models showed very low normalized percentage mean square error (MSE) values, always lower than 0.16%, confirming the feasibility and accuracy of the approach in estimating the 3D spatial distribution of E with a low number of components. Results showed that the electric field values induced in CNS tissues of children were within the ICNIRP basic restrictions for general public, with 99th percentiles of the E values obtained for each orientation showing median values in the range 1.9-2.1 mV/m. Similar 3D spatial distributions of the electric fields were found to be induced in CNS tissues of children of different ages. Bioelectromagnetics. 9999:1-10, 2018. © 2019 Bioelectromagnetics Society.


Assuntos
Exposição Ambiental/análise , Campos Magnéticos/efeitos adversos , Modelos Anatômicos , Adolescente , Criança , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Masculino , Distribuição Normal , Análise de Componente Principal , Processos Estocásticos
18.
Med Pr ; 70(1): 107-120, 2019 Feb 28.
Artigo em Polonês | MEDLINE | ID: mdl-30767954

RESUMO

The authors discuss the effects of static magnetic field (SMF) exposure based on reviewed literature reports. The systematic review covered both research carried out directly with people as well as studies with animals. A review was carried out in terms of various potential effects: carcinogenic effects, reproductive and metabolic disorders or the influence of SMF on the nervous and circulatory system. The possible biophysical and biological effects of the SMF were also described. Med Pr. 2019;70(1):107-20.


Assuntos
Campos Magnéticos/efeitos adversos , Animais , Humanos
19.
Am J Epidemiol ; 188(4): 796-805, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30649156

RESUMO

We explored the associations of occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and electric shocks with the risk of amyotrophic lateral sclerosis (ALS) in a pooled case-control study (European Multidisciplinary ALS Network Identification to Cure Motor Neurone Degeneration (Euro-MOTOR)) of data from 3 European countries. ALS patients and population-based controls were recruited in Ireland, Italy, and the Netherlands between 2010 and 2015. Lifetime occupational and lifestyle histories were obtained using structured questionnaires. We applied previously developed job exposure matrices assigning exposure levels to ELF-MF and potential for electric shocks. Odds ratios and 95% confidence intervals were estimated by means of logistic regression for exposure to either ELF-MF or electric shocks, adjusted for age, sex, study center, education, smoking, and alcohol consumption and for the respective other exposure. Complete occupational histories and information on confounding variables were available for 1,323 clinically confirmed ALS cases and 2,704 controls. Both ever having had exposure to ELF-MF above the background level (odds ratio = 1.16, 95% confidence interval: 1.01, 1.33) and ever having had potential exposure above background for electric shocks (odds ratio = 1.23, 95% confidence interval: 1.05, 1.43) were associated with ALS. Adjustment for the respective other exposure resulted in similar risk estimates. Heterogeneity in risks across study centers was significant for both exposures. Our findings support possible independent associations of occupational exposure to ELF-MF and electric shocks with the risk of ALS.


Assuntos
Esclerose Amiotrófica Lateral/epidemiologia , Traumatismos por Eletricidade/epidemiologia , Campos Magnéticos/efeitos adversos , Doenças Profissionais/epidemiologia , Exposição Ocupacional/análise , Adulto , Esclerose Amiotrófica Lateral/etiologia , Estudos de Casos e Controles , Traumatismos por Eletricidade/etiologia , Feminino , Humanos , Irlanda/epidemiologia , Itália/epidemiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Razão de Chances , Fatores de Risco
20.
PLoS One ; 14(1): e0209843, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30608963

RESUMO

Exposure to static magnetic fields (SMF) can cause changes in microorganism metabolism altering key subcellular functions. The purpose of this study was to investigate whether an applied SMF could induce biological effects on growth of Saccharomyces cerevisiae, and then to probe biochemical and bio-molecular responses. We found a decrease in growth and viability under SMF (250mT) after 6h with a significant decrease in colony forming units followed by an increase between 6 h and 9 h. Moreover, measurements of antioxidant enzyme activities (catalase, superoxide dismutase, glutathione peroxidase) demonstrated a particular profile suggesting oxidative stress. For instance, SOD and catalase activities increased in magnetized cultures after 9 h compared with unexposed samples. However, SMF exposure caused a decrease in glutathione peroxidase activity. Finally, SMF caused an increase in MDA levels as well as the content of protein carbonyl groups after 6 and 9 h of exposure.


Assuntos
Campos Magnéticos/efeitos adversos , Estresse Oxidativo/fisiologia , Saccharomyces cerevisiae/metabolismo , Antioxidantes/metabolismo , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Malondialdeído/metabolismo , Oxirredução , Saccharomyces cerevisiae/crescimento & desenvolvimento , Superóxido Dismutase/metabolismo
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